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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ U T I L --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2021, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Aspects; use Aspects;
with Atree; use Atree;
with Casing; use Casing;
with Checks; use Checks;
with Debug; use Debug;
with Einfo; use Einfo;
with Einfo.Entities; use Einfo.Entities;
with Einfo.Utils; use Einfo.Utils;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Aggr; use Exp_Aggr;
with Exp_Ch6; use Exp_Ch6;
with Exp_Ch7; use Exp_Ch7;
with Exp_Ch11; use Exp_Ch11;
with Freeze; use Freeze;
with Ghost; use Ghost;
with Inline; use Inline;
with Itypes; use Itypes;
with Lib; use Lib;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Restrict; use Restrict;
with Rident; use Rident;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch12; use Sem_Ch12;
with Sem_Ch13; use Sem_Ch13;
with Sem_Disp; use Sem_Disp;
with Sem_Elab; use Sem_Elab;
with Sem_Eval; use Sem_Eval;
with Sem_Res; use Sem_Res;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Sinfo.Utils; use Sinfo.Utils;
with Snames; use Snames;
with Stand; use Stand;
with Stringt; use Stringt;
with Tbuild; use Tbuild;
with Ttypes; use Ttypes;
with Validsw; use Validsw;
with GNAT.HTable;
package body Exp_Util is
---------------------------------------------------------
-- Handling of inherited class-wide pre/postconditions --
---------------------------------------------------------
-- Following AI12-0113, the expression for a class-wide condition is
-- transformed for a subprogram that inherits it, by replacing calls
-- to primitive operations of the original controlling type into the
-- corresponding overriding operations of the derived type. The following
-- hash table manages this mapping, and is expanded on demand whenever
-- such inherited expression needs to be constructed.
-- The mapping is also used to check whether an inherited operation has
-- a condition that depends on overridden operations. For such an
-- operation we must create a wrapper that is then treated as a normal
-- overriding. In SPARK mode such operations are illegal.
-- For a given root type there may be several type extensions with their
-- own overriding operations, so at various times a given operation of
-- the root will be mapped into different overridings. The root type is
-- also mapped into the current type extension to indicate that its
-- operations are mapped into the overriding operations of that current
-- type extension.
-- The contents of the map are as follows:
-- Key Value
-- Discriminant (Entity_Id) Discriminant (Entity_Id)
-- Discriminant (Entity_Id) Non-discriminant name (Entity_Id)
-- Discriminant (Entity_Id) Expression (Node_Id)
-- Primitive subprogram (Entity_Id) Primitive subprogram (Entity_Id)
-- Type (Entity_Id) Type (Entity_Id)
Type_Map_Size : constant := 511;
subtype Type_Map_Header is Integer range 0 .. Type_Map_Size - 1;
function Type_Map_Hash (Id : Entity_Id) return Type_Map_Header;
package Type_Map is new GNAT.HTable.Simple_HTable
(Header_Num => Type_Map_Header,
Key => Entity_Id,
Element => Node_Or_Entity_Id,
No_element => Empty,
Hash => Type_Map_Hash,
Equal => "=");
-----------------------
-- Local Subprograms --
-----------------------
function Build_Task_Array_Image
(Loc : Source_Ptr;
Id_Ref : Node_Id;
A_Type : Entity_Id;
Dyn : Boolean := False) return Node_Id;
-- Build function to generate the image string for a task that is an array
-- component, concatenating the images of each index. To avoid storage
-- leaks, the string is built with successive slice assignments. The flag
-- Dyn indicates whether this is called for the initialization procedure of
-- an array of tasks, or for the name of a dynamically created task that is
-- assigned to an indexed component.
function Build_Task_Image_Function
(Loc : Source_Ptr;
Decls : List_Id;
Stats : List_Id;
Res : Entity_Id) return Node_Id;
-- Common processing for Task_Array_Image and Task_Record_Image. Build
-- function body that computes image.
procedure Build_Task_Image_Prefix
(Loc : Source_Ptr;
Len : out Entity_Id;
Res : out Entity_Id;
Pos : out Entity_Id;
Prefix : Entity_Id;
Sum : Node_Id;
Decls : List_Id;
Stats : List_Id);
-- Common processing for Task_Array_Image and Task_Record_Image. Create
-- local variables and assign prefix of name to result string.
function Build_Task_Record_Image
(Loc : Source_Ptr;
Id_Ref : Node_Id;
Dyn : Boolean := False) return Node_Id;
-- Build function to generate the image string for a task that is a record
-- component. Concatenate name of variable with that of selector. The flag
-- Dyn indicates whether this is called for the initialization procedure of
-- record with task components, or for a dynamically created task that is
-- assigned to a selected component.
procedure Evaluate_Slice_Bounds (Slice : Node_Id);
-- Force evaluation of bounds of a slice, which may be given by a range
-- or by a subtype indication with or without a constraint.
function Is_Verifiable_DIC_Pragma (Prag : Node_Id) return Boolean;
-- Determine whether pragma Default_Initial_Condition denoted by Prag has
-- an assertion expression that should be verified at run time.
function Is_Uninitialized_Aggregate
(Exp : Node_Id;
T : Entity_Id) return Boolean;
-- Determine whether an array aggregate used in an object declaration
-- is uninitialized, when the aggregate is declared with a box and
-- the component type has no default value. Such an aggregate can be
-- optimized away to prevent the copying of uninitialized data, and
-- the bounds of the aggregate can be propagated directly to the
-- object declaration.
function Make_CW_Equivalent_Type
(T : Entity_Id;
E : Node_Id) return Entity_Id;
-- T is a class-wide type entity, E is the initial expression node that
-- constrains T in case such as: " X: T := E" or "new T'(E)". This function
-- returns the entity of the Equivalent type and inserts on the fly the
-- necessary declaration such as:
--
-- type anon is record
-- _parent : Root_Type (T); constrained with E discriminants (if any)
-- Extension : String (1 .. expr to match size of E);
-- end record;
--
-- This record is compatible with any object of the class of T thanks to
-- the first field and has the same size as E thanks to the second.
function Make_Literal_Range
(Loc : Source_Ptr;
Literal_Typ : Entity_Id) return Node_Id;
-- Produce a Range node whose bounds are:
-- Low_Bound (Literal_Type) ..
-- Low_Bound (Literal_Type) + (Length (Literal_Typ) - 1)
-- this is used for expanding declarations like X : String := "sdfgdfg";
--
-- If the index type of the target array is not integer, we generate:
-- Low_Bound (Literal_Type) ..
-- Literal_Type'Val
-- (Literal_Type'Pos (Low_Bound (Literal_Type))
-- + (Length (Literal_Typ) -1))
function Make_Non_Empty_Check
(Loc : Source_Ptr;
N : Node_Id) return Node_Id;
-- Produce a boolean expression checking that the unidimensional array
-- node N is not empty.
function New_Class_Wide_Subtype
(CW_Typ : Entity_Id;
N : Node_Id) return Entity_Id;
-- Create an implicit subtype of CW_Typ attached to node N
function Requires_Cleanup_Actions
(L : List_Id;
Lib_Level : Boolean;
Nested_Constructs : Boolean) return Boolean;
-- Given a list L, determine whether it contains one of the following:
--
-- 1) controlled objects
-- 2) library-level tagged types
--
-- Lib_Level is True when the list comes from a construct at the library
-- level, and False otherwise. Nested_Constructs is True when any nested
-- packages declared in L must be processed, and False otherwise.
function Side_Effect_Free_Attribute (Name : Name_Id) return Boolean;
-- Return True if the evaluation of the given attribute is considered
-- side-effect free, independently of its prefix and expressions.
-------------------------------------
-- Activate_Atomic_Synchronization --
-------------------------------------
procedure Activate_Atomic_Synchronization (N : Node_Id) is
Msg_Node : Node_Id;
begin
case Nkind (Parent (N)) is
-- Check for cases of appearing in the prefix of a construct where we
-- don't need atomic synchronization for this kind of usage.
when
-- Nothing to do if we are the prefix of an attribute, since we
-- do not want an atomic sync operation for things like 'Size.
N_Attribute_Reference
-- The N_Reference node is like an attribute
| N_Reference
-- Nothing to do for a reference to a component (or components)
-- of a composite object. Only reads and updates of the object
-- as a whole require atomic synchronization (RM C.6 (15)).
| N_Indexed_Component
| N_Selected_Component
| N_Slice
=>
-- For all the above cases, nothing to do if we are the prefix
if Prefix (Parent (N)) = N then
return;
end if;
when others =>
null;
end case;
-- Nothing to do for the identifier in an object renaming declaration,
-- the renaming itself does not need atomic synchronization.
if Nkind (Parent (N)) = N_Object_Renaming_Declaration then
return;
end if;
-- Go ahead and set the flag
Set_Atomic_Sync_Required (N);
-- Generate info message if requested
if Warn_On_Atomic_Synchronization then
case Nkind (N) is
when N_Identifier =>
Msg_Node := N;
when N_Expanded_Name
| N_Selected_Component
=>
Msg_Node := Selector_Name (N);
when N_Explicit_Dereference
| N_Indexed_Component
=>
Msg_Node := Empty;
when others =>
pragma Assert (False);
return;
end case;
if Present (Msg_Node) then
Error_Msg_N
("info: atomic synchronization set for &?N?", Msg_Node);
else
Error_Msg_N
("info: atomic synchronization set?N?", N);
end if;
end if;
end Activate_Atomic_Synchronization;
----------------------
-- Adjust_Condition --
----------------------
procedure Adjust_Condition (N : Node_Id) is
begin
if No (N) then
return;
end if;
declare
Loc : constant Source_Ptr := Sloc (N);
T : constant Entity_Id := Etype (N);
begin
-- Defend against a call where the argument has no type, or has a
-- type that is not Boolean. This can occur because of prior errors.
if No (T) or else not Is_Boolean_Type (T) then
return;
end if;
-- Apply validity checking if needed
if Validity_Checks_On and Validity_Check_Tests then
Ensure_Valid (N);
end if;
-- Immediate return if standard boolean, the most common case,
-- where nothing needs to be done.
if Base_Type (T) = Standard_Boolean then
return;
end if;
-- Case of zero/nonzero semantics or nonstandard enumeration
-- representation. In each case, we rewrite the node as:
-- ityp!(N) /= False'Enum_Rep
-- where ityp is an integer type with large enough size to hold any
-- value of type T.
if Nonzero_Is_True (T) or else Has_Non_Standard_Rep (T) then
Rewrite (N,
Make_Op_Ne (Loc,
Left_Opnd =>
Unchecked_Convert_To
(Integer_Type_For (Esize (T), Uns => False), N),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Enum_Rep,
Prefix =>
New_Occurrence_Of (First_Literal (T), Loc))));
Analyze_And_Resolve (N, Standard_Boolean);
else
Rewrite (N, Convert_To (Standard_Boolean, N));
Analyze_And_Resolve (N, Standard_Boolean);
end if;
end;
end Adjust_Condition;
------------------------
-- Adjust_Result_Type --
------------------------
procedure Adjust_Result_Type (N : Node_Id; T : Entity_Id) is
begin
-- Ignore call if current type is not Standard.Boolean
if Etype (N) /= Standard_Boolean then
return;
end if;
-- If result is already of correct type, nothing to do. Note that
-- this will get the most common case where everything has a type
-- of Standard.Boolean.
if Base_Type (T) = Standard_Boolean then
return;
else
declare
KP : constant Node_Kind := Nkind (Parent (N));
begin
-- If result is to be used as a Condition in the syntax, no need
-- to convert it back, since if it was changed to Standard.Boolean
-- using Adjust_Condition, that is just fine for this usage.
if KP in N_Raise_xxx_Error or else KP in N_Has_Condition then
return;
-- If result is an operand of another logical operation, no need
-- to reset its type, since Standard.Boolean is just fine, and
-- such operations always do Adjust_Condition on their operands.
elsif KP in N_Op_Boolean
or else KP in N_Short_Circuit
or else KP = N_Op_Not
then
return;
-- Otherwise we perform a conversion from the current type, which
-- must be Standard.Boolean, to the desired type. Use the base
-- type to prevent spurious constraint checks that are extraneous
-- to the transformation. The type and its base have the same
-- representation, standard or otherwise.
else
Set_Analyzed (N);
Rewrite (N, Convert_To (Base_Type (T), N));
Analyze_And_Resolve (N, Base_Type (T));
end if;
end;
end if;
end Adjust_Result_Type;
--------------------------
-- Append_Freeze_Action --
--------------------------
procedure Append_Freeze_Action (T : Entity_Id; N : Node_Id) is
Fnode : Node_Id;
begin
Ensure_Freeze_Node (T);
Fnode := Freeze_Node (T);
if No (Actions (Fnode)) then
Set_Actions (Fnode, New_List (N));
else
Append (N, Actions (Fnode));
end if;
end Append_Freeze_Action;
---------------------------
-- Append_Freeze_Actions --
---------------------------
procedure Append_Freeze_Actions (T : Entity_Id; L : List_Id) is
Fnode : Node_Id;
begin
if No (L) then
return;
end if;
Ensure_Freeze_Node (T);
Fnode := Freeze_Node (T);
if No (Actions (Fnode)) then
Set_Actions (Fnode, L);
else
Append_List (L, Actions (Fnode));
end if;
end Append_Freeze_Actions;
----------------------------------------
-- Attribute_Constrained_Static_Value --
----------------------------------------
function Attribute_Constrained_Static_Value (Pref : Node_Id) return Boolean
is
Ptyp : constant Entity_Id := Etype (Pref);
Formal_Ent : constant Entity_Id := Param_Entity (Pref);
function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean;
-- Ada 2005 (AI-363): Returns True if the object name Obj denotes a
-- view of an aliased object whose subtype is constrained.
---------------------------------
-- Is_Constrained_Aliased_View --
---------------------------------
function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean is
E : Entity_Id;
begin
if Is_Entity_Name (Obj) then
E := Entity (Obj);
if Present (Renamed_Object (E)) then
return Is_Constrained_Aliased_View (Renamed_Object (E));
else
return Is_Aliased (E) and then Is_Constrained (Etype (E));
end if;
else
return Is_Aliased_View (Obj)
and then
(Is_Constrained (Etype (Obj))
or else
(Nkind (Obj) = N_Explicit_Dereference
and then
not Object_Type_Has_Constrained_Partial_View
(Typ => Base_Type (Etype (Obj)),
Scop => Current_Scope)));
end if;
end Is_Constrained_Aliased_View;
-- Start of processing for Attribute_Constrained_Static_Value
begin
-- We are in a case where the attribute is known statically, and
-- implicit dereferences have been rewritten.
pragma Assert
(not (Present (Formal_Ent)
and then Ekind (Formal_Ent) /= E_Constant
and then Present (Extra_Constrained (Formal_Ent)))
and then
not (Is_Access_Type (Etype (Pref))
and then (not Is_Entity_Name (Pref)
or else Is_Object (Entity (Pref))))
and then
not (Nkind (Pref) = N_Identifier
and then Ekind (Entity (Pref)) = E_Variable
and then Present (Extra_Constrained (Entity (Pref)))));
if Is_Entity_Name (Pref) then
declare
Ent : constant Entity_Id := Entity (Pref);
Res : Boolean;
begin
-- (RM J.4) obsolescent cases
if Is_Type (Ent) then
-- Private type
if Is_Private_Type (Ent) then
Res := not Has_Discriminants (Ent)
or else Is_Constrained (Ent);
-- It not a private type, must be a generic actual type
-- that corresponded to a private type. We know that this
-- correspondence holds, since otherwise the reference
-- within the generic template would have been illegal.
else
if Is_Composite_Type (Underlying_Type (Ent)) then
Res := Is_Constrained (Ent);
else
Res := True;
end if;
end if;
else
-- If the prefix is not a variable or is aliased, then
-- definitely true; if it's a formal parameter without an
-- associated extra formal, then treat it as constrained.
-- Ada 2005 (AI-363): An aliased prefix must be known to be
-- constrained in order to set the attribute to True.
if not Is_Variable (Pref)
or else Present (Formal_Ent)
or else (Ada_Version < Ada_2005
and then Is_Aliased_View (Pref))
or else (Ada_Version >= Ada_2005
and then Is_Constrained_Aliased_View (Pref))
then
Res := True;
-- Variable case, look at type to see if it is constrained.
-- Note that the one case where this is not accurate (the
-- procedure formal case), has been handled above.
-- We use the Underlying_Type here (and below) in case the
-- type is private without discriminants, but the full type
-- has discriminants. This case is illegal, but we generate
-- it internally for passing to the Extra_Constrained
-- parameter.
else
-- In Ada 2012, test for case of a limited tagged type,
-- in which case the attribute is always required to
-- return True. The underlying type is tested, to make
-- sure we also return True for cases where there is an
-- unconstrained object with an untagged limited partial
-- view which has defaulted discriminants (such objects
-- always produce a False in earlier versions of
-- Ada). (Ada 2012: AI05-0214)
Res :=
Is_Constrained (Underlying_Type (Etype (Ent)))
or else
(Ada_Version >= Ada_2012
and then Is_Tagged_Type (Underlying_Type (Ptyp))
and then Is_Limited_Type (Ptyp));
end if;
end if;
return Res;
end;
-- Prefix is not an entity name. These are also cases where we can
-- always tell at compile time by looking at the form and type of the
-- prefix. If an explicit dereference of an object with constrained
-- partial view, this is unconstrained (Ada 2005: AI95-0363). If the
-- underlying type is a limited tagged type, then Constrained is
-- required to always return True (Ada 2012: AI05-0214).
else
return not Is_Variable (Pref)
or else
(Nkind (Pref) = N_Explicit_Dereference
and then
not Object_Type_Has_Constrained_Partial_View
(Typ => Base_Type (Ptyp),
Scop => Current_Scope))
or else Is_Constrained (Underlying_Type (Ptyp))
or else (Ada_Version >= Ada_2012
and then Is_Tagged_Type (Underlying_Type (Ptyp))
and then Is_Limited_Type (Ptyp));
end if;
end Attribute_Constrained_Static_Value;
------------------------------------
-- Build_Allocate_Deallocate_Proc --
------------------------------------
procedure Build_Allocate_Deallocate_Proc
(N : Node_Id;
Is_Allocate : Boolean)
is
function Find_Object (E : Node_Id) return Node_Id;
-- Given an arbitrary expression of an allocator, try to find an object
-- reference in it, otherwise return the original expression.
function Is_Allocate_Deallocate_Proc (Subp : Entity_Id) return Boolean;
-- Determine whether subprogram Subp denotes a custom allocate or
-- deallocate.
-----------------
-- Find_Object --
-----------------
function Find_Object (E : Node_Id) return Node_Id is
Expr : Node_Id;
begin
pragma Assert (Is_Allocate);
Expr := E;
loop
if Nkind (Expr) = N_Explicit_Dereference then
Expr := Prefix (Expr);
elsif Nkind (Expr) = N_Qualified_Expression then
Expr := Expression (Expr);
elsif Nkind (Expr) = N_Unchecked_Type_Conversion then
-- When interface class-wide types are involved in allocation,
-- the expander introduces several levels of address arithmetic
-- to perform dispatch table displacement. In this scenario the
-- object appears as:
-- Tag_Ptr (Base_Address (<object>'Address))
-- Detect this case and utilize the whole expression as the
-- "object" since it now points to the proper dispatch table.
if Is_RTE (Etype (Expr), RE_Tag_Ptr) then
exit;
-- Continue to strip the object
else
Expr := Expression (Expr);
end if;
else
exit;
end if;
end loop;
return Expr;
end Find_Object;
---------------------------------
-- Is_Allocate_Deallocate_Proc --
---------------------------------
function Is_Allocate_Deallocate_Proc (Subp : Entity_Id) return Boolean is
begin
-- Look for a subprogram body with only one statement which is a
-- call to Allocate_Any_Controlled / Deallocate_Any_Controlled.
if Ekind (Subp) = E_Procedure
and then Nkind (Parent (Parent (Subp))) = N_Subprogram_Body
then
declare
HSS : constant Node_Id :=
Handled_Statement_Sequence (Parent (Parent (Subp)));
Proc : Entity_Id;
begin
if Present (Statements (HSS))
and then Nkind (First (Statements (HSS))) =
N_Procedure_Call_Statement
then
Proc := Entity (Name (First (Statements (HSS))));
return
Is_RTE (Proc, RE_Allocate_Any_Controlled)
or else Is_RTE (Proc, RE_Deallocate_Any_Controlled);
end if;
end;
end if;
return False;
end Is_Allocate_Deallocate_Proc;
-- Local variables
Desig_Typ : Entity_Id;
Expr : Node_Id;
Needs_Fin : Boolean;
Pool_Id : Entity_Id;
Proc_To_Call : Node_Id := Empty;
Ptr_Typ : Entity_Id;
Use_Secondary_Stack_Pool : Boolean;
-- Start of processing for Build_Allocate_Deallocate_Proc
begin
-- Obtain the attributes of the allocation / deallocation
if Nkind (N) = N_Free_Statement then
Expr := Expression (N);
Ptr_Typ := Base_Type (Etype (Expr));
Proc_To_Call := Procedure_To_Call (N);
else
if Nkind (N) = N_Object_Declaration then
Expr := Expression (N);
else
Expr := N;
end if;
-- In certain cases an allocator with a qualified expression may
-- be relocated and used as the initialization expression of a
-- temporary:
-- before:
-- Obj : Ptr_Typ := new Desig_Typ'(...);
-- after:
-- Tmp : Ptr_Typ := new Desig_Typ'(...);
-- Obj : Ptr_Typ := Tmp;
-- Since the allocator is always marked as analyzed to avoid infinite
-- expansion, it will never be processed by this routine given that
-- the designated type needs finalization actions. Detect this case
-- and complete the expansion of the allocator.
if Nkind (Expr) = N_Identifier
and then Nkind (Parent (Entity (Expr))) = N_Object_Declaration
and then Nkind (Expression (Parent (Entity (Expr)))) = N_Allocator
then
Build_Allocate_Deallocate_Proc (Parent (Entity (Expr)), True);
return;
end if;
-- The allocator may have been rewritten into something else in which
-- case the expansion performed by this routine does not apply.
if Nkind (Expr) /= N_Allocator then
return;
end if;
Ptr_Typ := Base_Type (Etype (Expr));
Proc_To_Call := Procedure_To_Call (Expr);
end if;
Pool_Id := Associated_Storage_Pool (Ptr_Typ);
Desig_Typ := Available_View (Designated_Type (Ptr_Typ));
-- Handle concurrent types
if Is_Concurrent_Type (Desig_Typ)
and then Present (Corresponding_Record_Type (Desig_Typ))
then
Desig_Typ := Corresponding_Record_Type (Desig_Typ);
end if;
Use_Secondary_Stack_Pool :=
Is_RTE (Pool_Id, RE_SS_Pool)
or else (Nkind (Expr) = N_Allocator
and then Is_RTE (Storage_Pool (Expr), RE_SS_Pool));
-- Do not process allocations / deallocations without a pool
if No (Pool_Id) then
return;
-- Do not process allocations on / deallocations from the secondary
-- stack, except for access types used to implement indirect temps.
elsif Use_Secondary_Stack_Pool
and then not Old_Attr_Util.Indirect_Temps
.Is_Access_Type_For_Indirect_Temp (Ptr_Typ)
then
return;
-- Optimize the case where we are using the default Global_Pool_Object,
-- and we don't need the heavy finalization machinery.
elsif Is_RTE (Pool_Id, RE_Global_Pool_Object)
and then not Needs_Finalization (Desig_Typ)
then
return;
-- Do not replicate the machinery if the allocator / free has already
-- been expanded and has a custom Allocate / Deallocate.
elsif Present (Proc_To_Call)
and then Is_Allocate_Deallocate_Proc (Proc_To_Call)
then
return;
end if;
-- Finalization actions are required when the object to be allocated or
-- deallocated needs these actions and the associated access type is not
-- subject to pragma No_Heap_Finalization.
Needs_Fin :=
Needs_Finalization (Desig_Typ)
and then not No_Heap_Finalization (Ptr_Typ);
if Needs_Fin then
-- Do nothing if the access type may never allocate / deallocate
-- objects.
if No_Pool_Assigned (Ptr_Typ) then
return;
end if;
-- The allocation / deallocation of a controlled object must be
-- chained on / detached from a finalization master.
pragma Assert (Present (Finalization_Master (Ptr_Typ)));
-- The only other kind of allocation / deallocation supported by this
-- routine is on / from a subpool.
elsif Nkind (Expr) = N_Allocator
and then No (Subpool_Handle_Name (Expr))
then
return;
end if;
declare
Loc : constant Source_Ptr := Sloc (N);
Addr_Id : constant Entity_Id := Make_Temporary (Loc, 'A');
Alig_Id : constant Entity_Id := Make_Temporary (Loc, 'L');
Proc_Id : constant Entity_Id := Make_Temporary (Loc, 'P');
Size_Id : constant Entity_Id := Make_Temporary (Loc, 'S');
Actuals : List_Id;
Fin_Addr_Id : Entity_Id;
Fin_Mas_Act : Node_Id;
Fin_Mas_Id : Entity_Id;
Proc_To_Call : Entity_Id;
Subpool : Node_Id := Empty;
begin
-- Step 1: Construct all the actuals for the call to library routine
-- Allocate_Any_Controlled / Deallocate_Any_Controlled.
-- a) Storage pool
Actuals := New_List (New_Occurrence_Of (Pool_Id, Loc));
if Is_Allocate then
-- b) Subpool
if Nkind (Expr) = N_Allocator then
Subpool := Subpool_Handle_Name (Expr);
end if;
-- If a subpool is present it can be an arbitrary name, so make
-- the actual by copying the tree.
if Present (Subpool) then
Append_To (Actuals, New_Copy_Tree (Subpool, New_Sloc => Loc));
else
Append_To (Actuals, Make_Null (Loc));
end if;
-- c) Finalization master
if Needs_Fin then
Fin_Mas_Id := Finalization_Master (Ptr_Typ);
Fin_Mas_Act := New_Occurrence_Of (Fin_Mas_Id, Loc);
-- Handle the case where the master is actually a pointer to a
-- master. This case arises in build-in-place functions.
if Is_Access_Type (Etype (Fin_Mas_Id)) then
Append_To (Actuals, Fin_Mas_Act);
else
Append_To (Actuals,
Make_Attribute_Reference (Loc,
Prefix => Fin_Mas_Act,
Attribute_Name => Name_Unrestricted_Access));
end if;
else
Append_To (Actuals, Make_Null (Loc));
end if;
-- d) Finalize_Address
-- Primitive Finalize_Address is never generated in CodePeer mode
-- since it contains an Unchecked_Conversion.
if Needs_Fin and then not CodePeer_Mode then
Fin_Addr_Id := Finalize_Address (Desig_Typ);
pragma Assert (Present (Fin_Addr_Id));
Append_To (Actuals,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Fin_Addr_Id, Loc),
Attribute_Name => Name_Unrestricted_Access));
else
Append_To (Actuals, Make_Null (Loc));
end if;
end if;
-- e) Address
-- f) Storage_Size
-- g) Alignment
Append_To (Actuals, New_Occurrence_Of (Addr_Id, Loc));
Append_To (Actuals, New_Occurrence_Of (Size_Id, Loc));
if (Is_Allocate or else not Is_Class_Wide_Type (Desig_Typ))
and then not Use_Secondary_Stack_Pool
then
Append_To (Actuals, New_Occurrence_Of (Alig_Id, Loc));
-- For deallocation of class-wide types we obtain the value of
-- alignment from the Type Specific Record of the deallocated object.
-- This is needed because the frontend expansion of class-wide types
-- into equivalent types confuses the back end.
else
-- Generate:
-- Obj.all'Alignment
-- ... because 'Alignment applied to class-wide types is expanded
-- into the code that reads the value of alignment from the TSD
-- (see Expand_N_Attribute_Reference)
-- In the Use_Secondary_Stack_Pool case, Alig_Id is not
-- passed in and therefore must not be referenced.
Append_To (Actuals,
Unchecked_Convert_To (RTE (RE_Storage_Offset),
Make_Attribute_Reference (Loc,
Prefix =>
Make_Explicit_Dereference (Loc, Relocate_Node (Expr)),
Attribute_Name => Name_Alignment)));
end if;
-- h) Is_Controlled
if Needs_Fin then
Is_Controlled : declare
Flag_Id : constant Entity_Id := Make_Temporary (Loc, 'F');
Flag_Expr : Node_Id;
Param : Node_Id;
Pref : Node_Id;
Temp : Node_Id;
begin
if Is_Allocate then
Temp := Find_Object (Expression (Expr));
else
Temp := Expr;
end if;
-- Processing for allocations where the expression is a subtype
-- indication.
if Is_Allocate
and then Is_Entity_Name (Temp)
and then Is_Type (Entity (Temp))
then
Flag_Expr :=
New_Occurrence_Of
(Boolean_Literals
(Needs_Finalization (Entity (Temp))), Loc);
-- The allocation / deallocation of a class-wide object relies
-- on a runtime check to determine whether the object is truly
-- controlled or not. Depending on this check, the finalization
-- machinery will request or reclaim extra storage reserved for
-- a list header.
elsif Is_Class_Wide_Type (Desig_Typ) then
-- Detect a special case where interface class-wide types
-- are involved as the object appears as:
-- Tag_Ptr (Base_Address (<object>'Address))
-- The expression already yields the proper tag, generate:
-- Temp.all
if Is_RTE (Etype (Temp), RE_Tag_Ptr) then
Param :=
Make_Explicit_Dereference (Loc,
Prefix => Relocate_Node (Temp));
-- In the default case, obtain the tag of the object about
-- to be allocated / deallocated. Generate:
-- Temp'Tag
-- If the object is an unchecked conversion (typically to
-- an access to class-wide type), we must preserve the
-- conversion to ensure that the object is seen as tagged
-- in the code that follows.
else
Pref := Temp;
if Nkind (Parent (Pref)) = N_Unchecked_Type_Conversion
then
Pref := Parent (Pref);
end if;
Param :=
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Pref),
Attribute_Name => Name_Tag);
end if;
-- Generate:
-- Needs_Finalization (<Param>)
Flag_Expr :=
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Needs_Finalization), Loc),
Parameter_Associations => New_List (Param));
-- Processing for generic actuals
elsif Is_Generic_Actual_Type (Desig_Typ) then
Flag_Expr :=
New_Occurrence_Of (Boolean_Literals
(Needs_Finalization (Base_Type (Desig_Typ))), Loc);
-- The object does not require any specialized checks, it is
-- known to be controlled.
else
Flag_Expr := New_Occurrence_Of (Standard_True, Loc);
end if;
-- Create the temporary which represents the finalization state
-- of the expression. Generate:
--
-- F : constant Boolean := <Flag_Expr>;
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Flag_Id,
Constant_Present => True,
Object_Definition =>
New_Occurrence_Of (Standard_Boolean, Loc),
Expression => Flag_Expr));
Append_To (Actuals, New_Occurrence_Of (Flag_Id, Loc));
end Is_Controlled;
-- The object is not controlled
else
Append_To (Actuals, New_Occurrence_Of (Standard_False, Loc));
end if;
-- i) On_Subpool
if Is_Allocate then
Append_To (Actuals,
New_Occurrence_Of (Boolean_Literals (Present (Subpool)), Loc));
end if;
-- Step 2: Build a wrapper Allocate / Deallocate which internally
-- calls Allocate_Any_Controlled / Deallocate_Any_Controlled.
-- Select the proper routine to call
if Is_Allocate then
Proc_To_Call := RTE (RE_Allocate_Any_Controlled);
else
Proc_To_Call := RTE (RE_Deallocate_Any_Controlled);
end if;
-- Create a custom Allocate / Deallocate routine which has identical
-- profile to that of System.Storage_Pools.
declare
-- P : Root_Storage_Pool
function Pool_Param return Node_Id is (
Make_Parameter_Specification (Loc,
Defining_Identifier => Make_Temporary (Loc, 'P'),
Parameter_Type =>
New_Occurrence_Of (RTE (RE_Root_Storage_Pool), Loc)));
-- A : [out] Address
function Address_Param return Node_Id is (
Make_Parameter_Specification (Loc,
Defining_Identifier => Addr_Id,
Out_Present => Is_Allocate,
Parameter_Type =>
New_Occurrence_Of (RTE (RE_Address), Loc)));
-- S : Storage_Count
function Size_Param return Node_Id is (
Make_Parameter_Specification (Loc,
Defining_Identifier => Size_Id,
Parameter_Type =>
New_Occurrence_Of (RTE (RE_Storage_Count), Loc)));
-- L : Storage_Count
function Alignment_Param return Node_Id is (
Make_Parameter_Specification (Loc,
Defining_Identifier => Alig_Id,
Parameter_Type =>
New_Occurrence_Of (RTE (RE_Storage_Count), Loc)));
Formal_Params : List_Id;
begin
if Use_Secondary_Stack_Pool then
-- Gigi expects a different profile in the Secondary_Stack_Pool
-- case. There must be no uses of the two missing formals
-- (i.e., Pool_Param and Alignment_Param) in this case.
Formal_Params := New_List (Address_Param, Size_Param);
else
Formal_Params := New_List (
Pool_Param, Address_Param, Size_Param, Alignment_Param);
end if;
Insert_Action (N,
Make_Subprogram_Body (Loc,
Specification =>
-- procedure Pnn
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Proc_Id,
Parameter_Specifications => Formal_Params),
Declarations => No_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of (Proc_To_Call, Loc),
Parameter_Associations => Actuals)))),
Suppress => All_Checks);
end;
-- The newly generated Allocate / Deallocate becomes the default
-- procedure to call when the back end processes the allocation /
-- deallocation.
if Is_Allocate then
Set_Procedure_To_Call (Expr, Proc_Id);
else
Set_Procedure_To_Call (N, Proc_Id);
end if;
end;
end Build_Allocate_Deallocate_Proc;
-------------------------------
-- Build_Abort_Undefer_Block --
-------------------------------
function Build_Abort_Undefer_Block
(Loc : Source_Ptr;
Stmts : List_Id;
Context : Node_Id) return Node_Id
is
Exceptions_OK : constant Boolean :=
not Restriction_Active (No_Exception_Propagation);
AUD : Entity_Id;
Blk : Node_Id;
Blk_Id : Entity_Id;
HSS : Node_Id;
begin
-- The block should be generated only when undeferring abort in the
-- context of a potential exception.
pragma Assert (Abort_Allowed and Exceptions_OK);
-- Generate:
-- begin
-- <Stmts>
-- at end
-- Abort_Undefer_Direct;
-- end;
AUD := RTE (RE_Abort_Undefer_Direct);
HSS :=
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stmts,
At_End_Proc => New_Occurrence_Of (AUD, Loc));
Blk :=
Make_Block_Statement (Loc,
Handled_Statement_Sequence => HSS);
Set_Is_Abort_Block (Blk);
Add_Block_Identifier (Blk, Blk_Id);
Expand_At_End_Handler (HSS, Blk_Id);
-- Present the Abort_Undefer_Direct function to the back end to inline
-- the call to the routine.
Add_Inlined_Body (AUD, Context);
return Blk;
end Build_Abort_Undefer_Block;
---------------------------------
-- Build_Class_Wide_Expression --
---------------------------------
procedure Build_Class_Wide_Expression
(Pragma_Or_Expr : Node_Id;
Subp : Entity_Id;
Par_Subp : Entity_Id;
Adjust_Sloc : Boolean)
is
function Replace_Entity (N : Node_Id) return Traverse_Result;
-- Replace reference to formal of inherited operation or to primitive
-- operation of root type, with corresponding entity for derived type,
-- when constructing the class-wide condition of an overriding
-- subprogram.
--------------------
-- Replace_Entity --
--------------------
function Replace_Entity (N : Node_Id) return Traverse_Result is
New_E : Entity_Id;
begin
if Adjust_Sloc then
Adjust_Inherited_Pragma_Sloc (N);
end if;
if Nkind (N) in N_Identifier | N_Operator_Symbol
and then Present (Entity (N))
and then
(Is_Formal (Entity (N)) or else Is_Subprogram (Entity (N)))
and then
(Nkind (Parent (N)) /= N_Attribute_Reference
or else Attribute_Name (Parent (N)) /= Name_Class)
then
-- The replacement does not apply to dispatching calls within the
-- condition, but only to calls whose static tag is that of the
-- parent type.
if Is_Subprogram (Entity (N))
and then Nkind (Parent (N)) = N_Function_Call
and then Present (Controlling_Argument (Parent (N)))
then
return OK;
end if;
-- Determine whether entity has a renaming
New_E := Type_Map.Get (Entity (N));
if Present (New_E) then
Rewrite (N, New_Occurrence_Of (New_E, Sloc (N)));
end if;
-- Update type of function call node, which should be the same as
-- the function's return type.
if Is_Subprogram (Entity (N))
and then Nkind (Parent (N)) = N_Function_Call
then
Set_Etype (Parent (N), Etype (Entity (N)));
end if;
-- The whole expression will be reanalyzed
elsif Nkind (N) in N_Has_Etype then
Set_Analyzed (N, False);
end if;
return OK;
end Replace_Entity;
procedure Replace_Condition_Entities is
new Traverse_Proc (Replace_Entity);
-- Local variables
Par_Typ : constant Entity_Id := Find_Dispatching_Type (Par_Subp);
Subp_Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
-- Start of processing for Build_Class_Wide_Expression
begin
pragma Assert (Par_Typ /= Subp_Typ);
Update_Primitives_Mapping (Par_Subp, Subp);
Map_Formals (Par_Subp, Subp);
Replace_Condition_Entities (Pragma_Or_Expr);
end Build_Class_Wide_Expression;
--------------------
-- Build_DIC_Call --
--------------------
function Build_DIC_Call
(Loc : Source_Ptr;
Obj_Name : Node_Id;
Typ : Entity_Id) return Node_Id
is
Proc_Id : constant Entity_Id := DIC_Procedure (Typ);
Formal_Typ : constant Entity_Id := Etype (First_Formal (Proc_Id));
begin
-- The DIC procedure has a null body if assertions are disabled or
-- Assertion_Policy Ignore is in effect. In that case, it would be
-- nice to generate a null statement instead of a call to the DIC
-- procedure, but doing that seems to interfere with the determination
-- of ECRs (early call regions) in SPARK. ???
return
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Proc_Id, Loc),
Parameter_Associations => New_List (
Unchecked_Convert_To (Formal_Typ, Obj_Name)));
end Build_DIC_Call;
------------------------------
-- Build_DIC_Procedure_Body --
------------------------------
-- WARNING: This routine manages Ghost regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- Ghost mode.
procedure Build_DIC_Procedure_Body
(Typ : Entity_Id;
Partial_DIC : Boolean := False)
is
Pragmas_Seen : Elist_Id := No_Elist;
-- This list contains all DIC pragmas processed so far. The list is used
-- to avoid redundant Default_Initial_Condition checks.
procedure Add_DIC_Check
(DIC_Prag : Node_Id;
DIC_Expr : Node_Id;
Stmts : in out List_Id);
-- Subsidiary to all Add_xxx_DIC routines. Add a runtime check to verify
-- assertion expression DIC_Expr of pragma DIC_Prag. All generated code
-- is added to list Stmts.
procedure Add_Inherited_DIC
(DIC_Prag : Node_Id;
Par_Typ : Entity_Id;
Deriv_Typ : Entity_Id;
Stmts : in out List_Id);
-- Add a runtime check to verify the assertion expression of inherited
-- pragma DIC_Prag. Par_Typ is parent type, which is also the owner of
-- the DIC pragma. Deriv_Typ is the derived type inheriting the DIC
-- pragma. All generated code is added to list Stmts.
procedure Add_Inherited_Tagged_DIC
(DIC_Prag : Node_Id;
Expr : Node_Id;
Stmts : in out List_Id);
-- Add a runtime check to verify assertion expression DIC_Expr of
-- inherited pragma DIC_Prag. This routine applies class-wide pre-
-- and postcondition-like runtime semantics to the check. Expr is
-- the assertion expression after substitition has been performed
-- (via Replace_References). All generated code is added to list Stmts.
procedure Add_Inherited_DICs
(T : Entity_Id;
Priv_Typ : Entity_Id;
Full_Typ : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id);
-- Generate a DIC check for each inherited Default_Initial_Condition
-- coming from all parent types of type T. Priv_Typ and Full_Typ denote
-- the partial and full view of the parent type. Obj_Id denotes the
-- entity of the _object formal parameter of the DIC procedure. All
-- created checks are added to list Checks.
procedure Add_Own_DIC
(DIC_Prag : Node_Id;
DIC_Typ : Entity_Id;
Obj_Id : Entity_Id;
Stmts : in out List_Id);
-- Add a runtime check to verify the assertion expression of pragma
-- DIC_Prag. DIC_Typ is the owner of the DIC pragma. Obj_Id is the
-- object to substitute in the assertion expression for any references
-- to the current instance of the type All generated code is added to
-- list Stmts.
procedure Add_Parent_DICs
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id);
-- Generate a Default_Initial_Condition check for each inherited DIC
-- aspect coming from all parent types of type T. Obj_Id denotes the
-- entity of the _object formal parameter of the DIC procedure. All
-- created checks are added to list Checks.
-------------------
-- Add_DIC_Check --
-------------------
procedure Add_DIC_Check
(DIC_Prag : Node_Id;
DIC_Expr : Node_Id;
Stmts : in out List_Id)
is
Loc : constant Source_Ptr := Sloc (DIC_Prag);
Nam : constant Name_Id := Original_Aspect_Pragma_Name (DIC_Prag);
begin
-- The DIC pragma is ignored, nothing left to do
if Is_Ignored (DIC_Prag) then
null;
-- Otherwise the DIC expression must be checked at run time.
-- Generate:
-- pragma Check (<Nam>, <DIC_Expr>);
else
Append_New_To (Stmts,
Make_Pragma (Loc,
Pragma_Identifier =>
Make_Identifier (Loc, Name_Check),
Pragma_Argument_Associations => New_List (
Make_Pragma_Argument_Association (Loc,
Expression => Make_Identifier (Loc, Nam)),
Make_Pragma_Argument_Association (Loc,
Expression => DIC_Expr))));
end if;
-- Add the pragma to the list of processed pragmas
Append_New_Elmt (DIC_Prag, Pragmas_Seen);
end Add_DIC_Check;
-----------------------
-- Add_Inherited_DIC --
-----------------------
procedure Add_Inherited_DIC
(DIC_Prag : Node_Id;
Par_Typ : Entity_Id;
Deriv_Typ : Entity_Id;
Stmts : in out List_Id)
is
Deriv_Proc : constant Entity_Id := DIC_Procedure (Deriv_Typ);
Deriv_Obj : constant Entity_Id := First_Entity (Deriv_Proc);
Par_Proc : constant Entity_Id := DIC_Procedure (Par_Typ);
Par_Obj : constant Entity_Id := First_Entity (Par_Proc);
Loc : constant Source_Ptr := Sloc (DIC_Prag);
begin
pragma Assert (Present (Deriv_Proc) and then Present (Par_Proc));
-- Verify the inherited DIC assertion expression by calling the DIC
-- procedure of the parent type.
-- Generate:
-- <Par_Typ>DIC (Par_Typ (_object));
Append_New_To (Stmts,
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Par_Proc, Loc),
Parameter_Associations => New_List (
Convert_To
(Typ => Etype (Par_Obj),
Expr => New_Occurrence_Of (Deriv_Obj, Loc)))));
end Add_Inherited_DIC;
------------------------------
-- Add_Inherited_Tagged_DIC --
------------------------------
procedure Add_Inherited_Tagged_DIC
(DIC_Prag : Node_Id;
Expr : Node_Id;
Stmts : in out List_Id)
is
begin
-- Once the DIC assertion expression is fully processed, add a check
-- to the statements of the DIC procedure.
Add_DIC_Check
(DIC_Prag => DIC_Prag,
DIC_Expr => Expr,
Stmts => Stmts);
end Add_Inherited_Tagged_DIC;
------------------------
-- Add_Inherited_DICs --
------------------------
procedure Add_Inherited_DICs
(T : Entity_Id;
Priv_Typ : Entity_Id;
Full_Typ : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id)
is
Deriv_Typ : Entity_Id;
Expr : Node_Id;
Prag : Node_Id;
Prag_Expr : Node_Id;
Prag_Expr_Arg : Node_Id;
Prag_Typ : Node_Id;
Prag_Typ_Arg : Node_Id;
Par_Proc : Entity_Id;
-- The "partial" invariant procedure of Par_Typ
Par_Typ : Entity_Id;
-- The suitable view of the parent type used in the substitution of
-- type attributes.
begin
if not Present (Priv_Typ) and then not Present (Full_Typ) then
return;
end if;
-- When the type inheriting the class-wide invariant is a concurrent
-- type, use the corresponding record type because it contains all
-- primitive operations of the concurrent type and allows for proper
-- substitution.
if Is_Concurrent_Type (T) then
Deriv_Typ := Corresponding_Record_Type (T);
else
Deriv_Typ := T;
end if;
pragma Assert (Present (Deriv_Typ));
-- Determine which rep item chain to use. Precedence is given to that
-- of the parent type's partial view since it usually carries all the
-- class-wide invariants.
if Present (Priv_Typ) then
Prag := First_Rep_Item (Priv_Typ);
else
Prag := First_Rep_Item (Full_Typ);
end if;
while Present (Prag) loop
if Nkind (Prag) = N_Pragma
and then Pragma_Name (Prag) = Name_Default_Initial_Condition
then
-- Nothing to do if the pragma was already processed
if Contains (Pragmas_Seen, Prag) then
return;
end if;
-- Extract arguments of the Default_Initial_Condition pragma
Prag_Expr_Arg := First (Pragma_Argument_Associations (Prag));
Prag_Expr := Expression_Copy (Prag_Expr_Arg);
-- Pick up the implicit second argument of the pragma, which
-- indicates the type that the pragma applies to.
Prag_Typ_Arg := Next (Prag_Expr_Arg);
if Present (Prag_Typ_Arg) then
Prag_Typ := Get_Pragma_Arg (Prag_Typ_Arg);
else
Prag_Typ := Empty;
end if;
-- The pragma applies to the partial view of the parent type
if Present (Priv_Typ)
and then Present (Prag_Typ)
and then Entity (Prag_Typ) = Priv_Typ
then
Par_Typ := Priv_Typ;
-- The pragma applies to the full view of the parent type
elsif Present (Full_Typ)
and then Present (Prag_Typ)
and then Entity (Prag_Typ) = Full_Typ
then
Par_Typ := Full_Typ;
-- Otherwise the pragma does not belong to the parent type and
-- should not be considered.
else
return;
end if;
-- Substitute references in the DIC expression that are related
-- to the partial type with corresponding references related to
-- the derived type (call to Replace_References below).
Expr := New_Copy_Tree (Prag_Expr);
Par_Proc := Partial_DIC_Procedure (Par_Typ);
-- If there's not a partial DIC procedure (such as when a
-- full type doesn't have its own DIC, but is inherited from
-- a type with DIC), get the full DIC procedure.
if not Present (Par_Proc) then
Par_Proc := DIC_Procedure (Par_Typ);
end if;
Replace_References
(Expr => Expr,
Par_Typ => Par_Typ,
Deriv_Typ => Deriv_Typ,
Par_Obj => First_Formal (Par_Proc),
Deriv_Obj => Obj_Id);
-- Why are there different actions depending on whether T is
-- tagged? Can these be unified? ???
if Is_Tagged_Type (T) then
Add_Inherited_Tagged_DIC
(DIC_Prag => Prag,
Expr => Expr,
Stmts => Checks);
else
Add_Inherited_DIC
(DIC_Prag => Prag,
Par_Typ => Par_Typ,
Deriv_Typ => Deriv_Typ,
Stmts => Checks);
end if;
-- Leave as soon as we get a DIC pragma, since we'll visit
-- the pragmas of the parents, so will get to any "inherited"
-- pragmas that way.
return;
end if;
Next_Rep_Item (Prag);
end loop;
end Add_Inherited_DICs;
-----------------
-- Add_Own_DIC --
-----------------
procedure Add_Own_DIC
(DIC_Prag : Node_Id;
DIC_Typ : Entity_Id;
Obj_Id : Entity_Id;
Stmts : in out List_Id)
is
DIC_Args : constant List_Id :=
Pragma_Argument_Associations (DIC_Prag);
DIC_Arg : constant Node_Id := First (DIC_Args);
DIC_Asp : constant Node_Id := Corresponding_Aspect (DIC_Prag);
DIC_Expr : constant Node_Id := Get_Pragma_Arg (DIC_Arg);
-- Local variables
Typ_Decl : constant Node_Id := Declaration_Node (DIC_Typ);
Expr : Node_Id;
-- Start of processing for Add_Own_DIC
begin
pragma Assert (Present (DIC_Expr));
Expr := New_Copy_Tree (DIC_Expr);
-- Perform the following substitution:
-- * Replace the current instance of DIC_Typ with a reference to
-- the _object formal parameter of the DIC procedure.
Replace_Type_References
(Expr => Expr,
Typ => DIC_Typ,
Obj_Id => Obj_Id);
-- Preanalyze the DIC expression to detect errors and at the same
-- time capture the visibility of the proper package part.
Set_Parent (Expr, Typ_Decl);
Preanalyze_Assert_Expression (Expr, Any_Boolean);
-- Save a copy of the expression with all replacements and analysis
-- already taken place in case a derived type inherits the pragma.
-- The copy will be used as the foundation of the derived type's own
-- version of the DIC assertion expression.
if Is_Tagged_Type (DIC_Typ) then
Set_Expression_Copy (DIC_Arg, New_Copy_Tree (Expr));
end if;
-- If the pragma comes from an aspect specification, replace the
-- saved expression because all type references must be substituted
-- for the call to Preanalyze_Spec_Expression in Check_Aspect_At_xxx
-- routines.
if Present (DIC_Asp) then
Set_Entity (Identifier (DIC_Asp), New_Copy_Tree (Expr));
end if;
-- Once the DIC assertion expression is fully processed, add a check
-- to the statements of the DIC procedure (unless the type is an
-- abstract type, in which case we don't want the possibility of
-- generating a call to an abstract function of the type; such DIC
-- procedures can never be called in any case, so not generating the
-- check at all is OK).
if not Is_Abstract_Type (DIC_Typ) or else GNATprove_Mode then
Add_DIC_Check
(DIC_Prag => DIC_Prag,
DIC_Expr => Expr,
Stmts => Stmts);
end if;
end Add_Own_DIC;
---------------------
-- Add_Parent_DICs --
---------------------
procedure Add_Parent_DICs
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id)
is
Dummy_1 : Entity_Id;
Dummy_2 : Entity_Id;
Curr_Typ : Entity_Id;
-- The entity of the current type being examined
Full_Typ : Entity_Id;
-- The full view of Par_Typ
Par_Typ : Entity_Id;
-- The entity of the parent type
Priv_Typ : Entity_Id;
-- The partial view of Par_Typ
Op_Node : Elmt_Id;
Par_Prim : Entity_Id;
Prim : Entity_Id;
begin
-- Map the overridden primitive to the overriding one; required by
-- Replace_References (called by Add_Inherited_DICs) to handle calls
-- to parent primitives.
Op_Node := First_Elmt (Primitive_Operations (T));
while Present (Op_Node) loop
Prim := Node (Op_Node);
if Present (Overridden_Operation (Prim))
and then Comes_From_Source (Prim)
then
Par_Prim := Overridden_Operation (Prim);
-- Create a mapping of the form:
-- parent type primitive -> derived type primitive
Type_Map.Set (Par_Prim, Prim);
end if;
Next_Elmt (Op_Node);
end loop;
-- Climb the parent type chain
Curr_Typ := T;
loop
-- Do not consider subtypes, as they inherit the DICs from their
-- base types.
Par_Typ := Base_Type (Etype (Base_Type (Curr_Typ)));
-- Stop the climb once the root of the parent chain is
-- reached.
exit when Curr_Typ = Par_Typ;
-- Process the DICs of the parent type
Get_Views (Par_Typ, Priv_Typ, Full_Typ, Dummy_1, Dummy_2);
-- Only try to inherit a DIC pragma from the parent type Par_Typ
-- if it Has_Own_DIC pragma. The loop will proceed up the parent
-- chain to find all types that have their own DIC.
if Has_Own_DIC (Par_Typ) then
Add_Inherited_DICs
(T => T,
Priv_Typ => Priv_Typ,
Full_Typ => Full_Typ,
Obj_Id => Obj_Id,
Checks => Checks);
end if;
Curr_Typ := Par_Typ;
end loop;
end Add_Parent_DICs;
-- Local variables
Loc : constant Source_Ptr := Sloc (Typ);
Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
Saved_IGR : constant Node_Id := Ignored_Ghost_Region;
-- Save the Ghost-related attributes to restore on exit
DIC_Prag : Node_Id;
DIC_Typ : Entity_Id;
Dummy_1 : Entity_Id;
Dummy_2 : Entity_Id;
Proc_Body : Node_Id;
Proc_Body_Id : Entity_Id;
Proc_Decl : Node_Id;
Proc_Id : Entity_Id;
Stmts : List_Id := No_List;
CRec_Typ : Entity_Id := Empty;
-- The corresponding record type of Full_Typ
Full_Typ : Entity_Id := Empty;
-- The full view of the working type
Obj_Id : Entity_Id := Empty;
-- The _object formal parameter of the invariant procedure
Part_Proc : Entity_Id := Empty;
-- The entity of the "partial" invariant procedure
Priv_Typ : Entity_Id := Empty;
-- The partial view of the working type
Work_Typ : Entity_Id;
-- The working type
-- Start of processing for Build_DIC_Procedure_Body
begin
Work_Typ := Base_Type (Typ);
-- Do not process class-wide types as these are Itypes, but lack a first
-- subtype (see below).
if Is_Class_Wide_Type (Work_Typ) then
return;
-- Do not process the underlying full view of a private type. There is
-- no way to get back to the partial view, plus the body will be built
-- by the full view or the base type.
elsif Is_Underlying_Full_View (Work_Typ) then
return;
-- Use the first subtype when dealing with various base types
elsif Is_Itype (Work_Typ) then
Work_Typ := First_Subtype (Work_Typ);
-- The input denotes the corresponding record type of a protected or a
-- task type. Work with the concurrent type because the corresponding
-- record type may not be visible to clients of the type.
elsif Ekind (Work_Typ) = E_Record_Type
and then Is_Concurrent_Record_Type (Work_Typ)
then
Work_Typ := Corresponding_Concurrent_Type (Work_Typ);
end if;
-- The working type may be subject to pragma Ghost. Set the mode now to
-- ensure that the DIC procedure is properly marked as Ghost.
Set_Ghost_Mode (Work_Typ);
-- The working type must be either define a DIC pragma of its own or
-- inherit one from a parent type.
pragma Assert (Has_DIC (Work_Typ));
-- Recover the type which defines the DIC pragma. This is either the
-- working type itself or a parent type when the pragma is inherited.
DIC_Typ := Find_DIC_Type (Work_Typ);
pragma Assert (Present (DIC_Typ));
DIC_Prag := Get_Pragma (DIC_Typ, Pragma_Default_Initial_Condition);
pragma Assert (Present (DIC_Prag));
-- Nothing to do if pragma DIC appears without an argument or its sole
-- argument is "null".
if not Is_Verifiable_DIC_Pragma (DIC_Prag) then
goto Leave;
end if;
-- Obtain both views of the type
Get_Views (Work_Typ, Priv_Typ, Full_Typ, Dummy_1, CRec_Typ);
-- The caller requests a body for the partial DIC procedure
if Partial_DIC then
Proc_Id := Partial_DIC_Procedure (Work_Typ);
-- The "full" DIC procedure body was already created
-- Create a declaration for the "partial" DIC procedure if it
-- is not available.
if No (Proc_Id) then
Build_DIC_Procedure_Declaration
(Typ => Work_Typ,
Partial_DIC => True);
Proc_Id := Partial_DIC_Procedure (Work_Typ);
end if;
-- The caller requests a body for the "full" DIC procedure
else
Proc_Id := DIC_Procedure (Work_Typ);
Part_Proc := Partial_DIC_Procedure (Work_Typ);
-- Create a declaration for the "full" DIC procedure if it is
-- not available.
if No (Proc_Id) then
Build_DIC_Procedure_Declaration (Work_Typ);
Proc_Id := DIC_Procedure (Work_Typ);
end if;
end if;
-- At this point there should be a DIC procedure declaration
pragma Assert (Present (Proc_Id));
Proc_Decl := Unit_Declaration_Node (Proc_Id);
-- Nothing to do if the DIC procedure already has a body
if Present (Corresponding_Body (Proc_Decl)) then
goto Leave;
end if;
-- Emulate the environment of the DIC procedure by installing its scope
-- and formal parameters.
Push_Scope (Proc_Id);
Install_Formals (Proc_Id);
Obj_Id := First_Formal (Proc_Id);
pragma Assert (Present (Obj_Id));
-- The "partial" DIC procedure verifies the DICs of the partial view
-- only.
if Partial_DIC then
pragma Assert (Present (Priv_Typ));
if Has_Own_DIC (Work_Typ) then -- If we're testing this then maybe
Add_Own_DIC -- we shouldn't be calling Find_DIC_Typ above???
(DIC_Prag => DIC_Prag,
DIC_Typ => DIC_Typ, -- Should this just be Work_Typ???
Obj_Id => Obj_Id,
Stmts => Stmts);
end if;
-- Otherwise, the "full" DIC procedure verifies the DICs inherited from
-- parent types, as well as indirectly verifying the DICs of the partial
-- view by calling the "partial" DIC procedure.
else
-- Check the DIC of the partial view by calling the "partial" DIC
-- procedure, unless the partial DIC body is empty. Generate:
-- <Work_Typ>Partial_DIC (_object);
if Present (Part_Proc) and then not Has_Null_Body (Part_Proc) then
Append_New_To (Stmts,
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Part_Proc, Loc),
Parameter_Associations => New_List (
New_Occurrence_Of (Obj_Id, Loc))));
end if;
-- Process inherited Default_Initial_Conditions for all parent types
Add_Parent_DICs (Work_Typ, Obj_Id, Stmts);
end if;
End_Scope;
-- Produce an empty completing body in the following cases:
-- * Assertions are disabled
-- * The DIC Assertion_Policy is Ignore
if No (Stmts) then
Stmts := New_List (Make_Null_Statement (Loc));
end if;
-- Generate:
-- procedure <Work_Typ>DIC (_object : <Work_Typ>) is
-- begin
-- <Stmts>
-- end <Work_Typ>DIC;
Proc_Body :=
Make_Subprogram_Body (Loc,
Specification =>
Copy_Subprogram_Spec (Parent (Proc_Id)),
Declarations => Empty_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stmts));
Proc_Body_Id := Defining_Entity (Proc_Body);
-- Perform minor decoration in case the body is not analyzed
Mutate_Ekind (Proc_Body_Id, E_Subprogram_Body);
Set_Etype (Proc_Body_Id, Standard_Void_Type);
Set_Scope (Proc_Body_Id, Current_Scope);
Set_SPARK_Pragma (Proc_Body_Id, SPARK_Pragma (Proc_Id));
Set_SPARK_Pragma_Inherited
(Proc_Body_Id, SPARK_Pragma_Inherited (Proc_Id));
-- Link both spec and body to avoid generating duplicates
Set_Corresponding_Body (Proc_Decl, Proc_Body_Id);
Set_Corresponding_Spec (Proc_Body, Proc_Id);
-- The body should not be inserted into the tree when the context
-- is a generic unit because it is not part of the template.
-- Note that the body must still be generated in order to resolve the
-- DIC assertion expression.
if Inside_A_Generic then
null;
-- Semi-insert the body into the tree for GNATprove by setting its
-- Parent field. This allows for proper upstream tree traversals.
elsif GNATprove_Mode then
Set_Parent (Proc_Body, Parent (Declaration_Node (Work_Typ)));
-- Otherwise the body is part of the freezing actions of the working
-- type.
else
Append_Freeze_Action (Work_Typ, Proc_Body);
end if;
<<Leave>>
Restore_Ghost_Region (Saved_GM, Saved_IGR);
end Build_DIC_Procedure_Body;
-------------------------------------
-- Build_DIC_Procedure_Declaration --
-------------------------------------
-- WARNING: This routine manages Ghost regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- Ghost mode.
procedure Build_DIC_Procedure_Declaration
(Typ : Entity_Id;
Partial_DIC : Boolean := False)
is
Loc : constant Source_Ptr := Sloc (Typ);
Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
Saved_IGR : constant Node_Id := Ignored_Ghost_Region;
-- Save the Ghost-related attributes to restore on exit
DIC_Prag : Node_Id;
DIC_Typ : Entity_Id;
Proc_Decl : Node_Id;
Proc_Id : Entity_Id;
Proc_Nam : Name_Id;
Typ_Decl : Node_Id;
CRec_Typ : Entity_Id;
-- The corresponding record type of Full_Typ
Full_Typ : Entity_Id;
-- The full view of working type
Obj_Id : Entity_Id;
-- The _object formal parameter of the DIC procedure
Priv_Typ : Entity_Id;
-- The partial view of working type
UFull_Typ : Entity_Id;
-- The underlying full view of Full_Typ
Work_Typ : Entity_Id;
-- The working type
begin
Work_Typ := Base_Type (Typ);
-- Do not process class-wide types as these are Itypes, but lack a first
-- subtype (see below).
if Is_Class_Wide_Type (Work_Typ) then
return;
-- Do not process the underlying full view of a private type. There is
-- no way to get back to the partial view, plus the body will be built
-- by the full view or the base type.
elsif Is_Underlying_Full_View (Work_Typ) then
return;
-- Use the first subtype when dealing with various base types
elsif Is_Itype (Work_Typ) then
Work_Typ := First_Subtype (Work_Typ);
-- The input denotes the corresponding record type of a protected or a
-- task type. Work with the concurrent type because the corresponding
-- record type may not be visible to clients of the type.
elsif Ekind (Work_Typ) = E_Record_Type
and then Is_Concurrent_Record_Type (Work_Typ)
then
Work_Typ := Corresponding_Concurrent_Type (Work_Typ);
end if;
-- The working type may be subject to pragma Ghost. Set the mode now to
-- ensure that the DIC procedure is properly marked as Ghost.
Set_Ghost_Mode (Work_Typ);
-- The type must be either subject to a DIC pragma or inherit one from a
-- parent type.
pragma Assert (Has_DIC (Work_Typ));
-- Recover the type which defines the DIC pragma. This is either the
-- working type itself or a parent type when the pragma is inherited.
DIC_Typ := Find_DIC_Type (Work_Typ);
pragma Assert (Present (DIC_Typ));
DIC_Prag := Get_Pragma (DIC_Typ, Pragma_Default_Initial_Condition);
pragma Assert (Present (DIC_Prag));
-- Nothing to do if pragma DIC appears without an argument or its sole
-- argument is "null".
if not Is_Verifiable_DIC_Pragma (DIC_Prag) then
goto Leave;
end if;
-- Nothing to do if the type already has a "partial" DIC procedure
if Partial_DIC then
if Present (Partial_DIC_Procedure (Work_Typ)) then
goto Leave;
end if;
-- Nothing to do if the type already has a "full" DIC procedure
elsif Present (DIC_Procedure (Work_Typ)) then
goto Leave;
end if;
-- The caller requests the declaration of the "partial" DIC procedure
if Partial_DIC then
Proc_Nam := New_External_Name (Chars (Work_Typ), "Partial_DIC");
-- Otherwise the caller requests the declaration of the "full" DIC
-- procedure.
else
Proc_Nam := New_External_Name (Chars (Work_Typ), "DIC");
end if;
Proc_Id :=
Make_Defining_Identifier (Loc, Chars => Proc_Nam);
-- Perform minor decoration in case the declaration is not analyzed
Mutate_Ekind (Proc_Id, E_Procedure);
Set_Etype (Proc_Id, Standard_Void_Type);
Set_Is_DIC_Procedure (Proc_Id);
Set_Scope (Proc_Id, Current_Scope);
Set_SPARK_Pragma (Proc_Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Proc_Id);
Set_DIC_Procedure (Work_Typ, Proc_Id);
-- The DIC procedure requires debug info when the assertion expression
-- is subject to Source Coverage Obligations.
if Generate_SCO then
Set_Debug_Info_Needed (Proc_Id);
end if;
-- Obtain all views of the input type
Get_Views (Work_Typ, Priv_Typ, Full_Typ, UFull_Typ, CRec_Typ);
-- Associate the DIC procedure and various flags with all views
Propagate_DIC_Attributes (Priv_Typ, From_Typ => Work_Typ);
Propagate_DIC_Attributes (Full_Typ, From_Typ => Work_Typ);
Propagate_DIC_Attributes (UFull_Typ, From_Typ => Work_Typ);
Propagate_DIC_Attributes (CRec_Typ, From_Typ => Work_Typ);
-- The declaration of the DIC procedure must be inserted after the
-- declaration of the partial view as this allows for proper external
-- visibility.
if Present (Priv_Typ) then
Typ_Decl := Declaration_Node (Priv_Typ);
-- Derived types with the full view as parent do not have a partial
-- view. Insert the DIC procedure after the derived type.
else
Typ_Decl := Declaration_Node (Full_Typ);
end if;
-- The type should have a declarative node
pragma Assert (Present (Typ_Decl));
-- Create the formal parameter which emulates the variable-like behavior
-- of the type's current instance.
Obj_Id := Make_Defining_Identifier (Loc, Chars => Name_uObject);
-- Perform minor decoration in case the declaration is not analyzed
Mutate_Ekind (Obj_Id, E_In_Parameter);
Set_Etype (Obj_Id, Work_Typ);
Set_Scope (Obj_Id, Proc_Id);
Set_First_Entity (Proc_Id, Obj_Id);
Set_Last_Entity (Proc_Id, Obj_Id);
-- Generate:
-- procedure <Work_Typ>DIC (_object : <Work_Typ>);
Proc_Decl :=
Make_Subprogram_Declaration (Loc,
Specification =>
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Proc_Id,
Parameter_Specifications => New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => Obj_Id,
Parameter_Type =>
New_Occurrence_Of (Work_Typ, Loc)))));
-- The declaration should not be inserted into the tree when the context
-- is a generic unit because it is not part of the template.
if Inside_A_Generic then
null;
-- Semi-insert the declaration into the tree for GNATprove by setting
-- its Parent field. This allows for proper upstream tree traversals.
elsif GNATprove_Mode then
Set_Parent (Proc_Decl, Parent (Typ_Decl));
-- Otherwise insert the declaration
else
Insert_After_And_Analyze (Typ_Decl, Proc_Decl);
end if;
<<Leave>>
Restore_Ghost_Region (Saved_GM, Saved_IGR);
end Build_DIC_Procedure_Declaration;
------------------------------------
-- Build_Invariant_Procedure_Body --
------------------------------------
-- WARNING: This routine manages Ghost regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- Ghost mode.
procedure Build_Invariant_Procedure_Body
(Typ : Entity_Id;
Partial_Invariant : Boolean := False)
is
Loc : constant Source_Ptr := Sloc (Typ);
Pragmas_Seen : Elist_Id := No_Elist;
-- This list contains all invariant pragmas processed so far. The list
-- is used to avoid generating redundant invariant checks.
Produced_Check : Boolean := False;
-- This flag tracks whether the type has produced at least one invariant
-- check. The flag is used as a sanity check at the end of the routine.
-- NOTE: most of the routines in Build_Invariant_Procedure_Body are
-- intentionally unnested to avoid deep indentation of code.
-- NOTE: all Add_xxx_Invariants routines are reactive. In other words
-- they emit checks, loops (for arrays) and case statements (for record
-- variant parts) only when there are invariants to verify. This keeps
-- the body of the invariant procedure free of useless code.
procedure Add_Array_Component_Invariants
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id);
-- Generate an invariant check for each component of array type T.
-- Obj_Id denotes the entity of the _object formal parameter of the
-- invariant procedure. All created checks are added to list Checks.
procedure Add_Inherited_Invariants
(T : Entity_Id;
Priv_Typ : Entity_Id;
Full_Typ : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id);
-- Generate an invariant check for each inherited class-wide invariant
-- coming from all parent types of type T. Priv_Typ and Full_Typ denote
-- the partial and full view of the parent type. Obj_Id denotes the
-- entity of the _object formal parameter of the invariant procedure.
-- All created checks are added to list Checks.
procedure Add_Interface_Invariants
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id);
-- Generate an invariant check for each inherited class-wide invariant
-- coming from all interfaces implemented by type T. Obj_Id denotes the
-- entity of the _object formal parameter of the invariant procedure.
-- All created checks are added to list Checks.
procedure Add_Invariant_Check
(Prag : Node_Id;
Expr : Node_Id;
Checks : in out List_Id;
Inherited : Boolean := False);
-- Subsidiary to all Add_xxx_Invariant routines. Add a runtime check to
-- verify assertion expression Expr of pragma Prag. All generated code
-- is added to list Checks. Flag Inherited should be set when the pragma
-- is inherited from a parent or interface type.
procedure Add_Own_Invariants
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id;
Priv_Item : Node_Id := Empty);
-- Generate an invariant check for each invariant found for type T.
-- Obj_Id denotes the entity of the _object formal parameter of the
-- invariant procedure. All created checks are added to list Checks.
-- Priv_Item denotes the first rep item of the private type.
procedure Add_Parent_Invariants
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id);
-- Generate an invariant check for each inherited class-wide invariant
-- coming from all parent types of type T. Obj_Id denotes the entity of
-- the _object formal parameter of the invariant procedure. All created
-- checks are added to list Checks.
procedure Add_Record_Component_Invariants
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id);
-- Generate an invariant check for each component of record type T.
-- Obj_Id denotes the entity of the _object formal parameter of the
-- invariant procedure. All created checks are added to list Checks.
------------------------------------
-- Add_Array_Component_Invariants --
------------------------------------
procedure Add_Array_Component_Invariants
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id)
is
Comp_Typ : constant Entity_Id := Component_Type (T);
Dims : constant Pos := Number_Dimensions (T);
procedure Process_Array_Component
(Indices : List_Id;
Comp_Checks : in out List_Id);
-- Generate an invariant check for an array component identified by
-- the indices in list Indices. All created checks are added to list
-- Comp_Checks.
procedure Process_One_Dimension
(Dim : Pos;
Indices : List_Id;
Dim_Checks : in out List_Id);
-- Generate a loop over the Nth dimension Dim of an array type. List
-- Indices contains all array indices for the dimension. All created
-- checks are added to list Dim_Checks.
-----------------------------
-- Process_Array_Component --
-----------------------------
procedure Process_Array_Component
(Indices : List_Id;
Comp_Checks : in out List_Id)
is
Proc_Id : Entity_Id;
begin
if Has_Invariants (Comp_Typ) then
-- In GNATprove mode, the component invariants are checked by
-- other means. They should not be added to the array type
-- invariant procedure, so that the procedure can be used to
-- check the array type invariants if any.
if GNATprove_Mode then
null;
else
Proc_Id := Invariant_Procedure (Base_Type (Comp_Typ));
-- The component type should have an invariant procedure
-- if it has invariants of its own or inherits class-wide
-- invariants from parent or interface types.
pragma Assert (Present (Proc_Id));
-- Generate:
-- <Comp_Typ>Invariant (_object (<Indices>));
-- The invariant procedure has a null body if assertions are
-- disabled or Assertion_Policy Ignore is in effect.
if not Has_Null_Body (Proc_Id) then
Append_New_To (Comp_Checks,
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of (Proc_Id, Loc),
Parameter_Associations => New_List (
Make_Indexed_Component (Loc,
Prefix => New_Occurrence_Of (Obj_Id, Loc),
Expressions => New_Copy_List (Indices)))));
end if;
end if;
Produced_Check := True;
end if;
end Process_Array_Component;
---------------------------
-- Process_One_Dimension --
---------------------------
procedure Process_One_Dimension
(Dim : Pos;
Indices : List_Id;
Dim_Checks : in out List_Id)
is
Comp_Checks : List_Id := No_List;
Index : Entity_Id;
begin
-- Generate the invariant checks for the array component after all
-- dimensions have produced their respective loops.
if Dim > Dims then
Process_Array_Component
(Indices => Indices,
Comp_Checks => Dim_Checks);
-- Otherwise create a loop for the current dimension
else
-- Create a new loop variable for each dimension
Index :=
Make_Defining_Identifier (Loc,
Chars => New_External_Name ('I', Dim));
Append_To (Indices, New_Occurrence_Of (Index, Loc));
Process_One_Dimension
(Dim => Dim + 1,
Indices => Indices,
Dim_Checks => Comp_Checks);
-- Generate:
-- for I<Dim> in _object'Range (<Dim>) loop
-- <Comp_Checks>
-- end loop;
-- Note that the invariant procedure may have a null body if
-- assertions are disabled or Assertion_Policy Ignore is in
-- effect.
if Present (Comp_Checks) then
Append_New_To (Dim_Checks,
Make_Implicit_Loop_Statement (T,
Identifier => Empty,
Iteration_Scheme =>
Make_Iteration_Scheme (Loc,
Loop_Parameter_Specification =>
Make_Loop_Parameter_Specification (Loc,
Defining_Identifier => Index,
Discrete_Subtype_Definition =>
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Obj_Id, Loc),
Attribute_Name => Name_Range,
Expressions => New_List (
Make_Integer_Literal (Loc, Dim))))),
Statements => Comp_Checks));
end if;
end if;
end Process_One_Dimension;
-- Start of processing for Add_Array_Component_Invariants
begin
Process_One_Dimension
(Dim => 1,
Indices => New_List,
Dim_Checks => Checks);
end Add_Array_Component_Invariants;
------------------------------
-- Add_Inherited_Invariants --
------------------------------
procedure Add_Inherited_Invariants
(T : Entity_Id;
Priv_Typ : Entity_Id;
Full_Typ : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id)
is
Deriv_Typ : Entity_Id;
Expr : Node_Id;
Prag : Node_Id;
Prag_Expr : Node_Id;
Prag_Expr_Arg : Node_Id;
Prag_Typ : Node_Id;
Prag_Typ_Arg : Node_Id;
Par_Proc : Entity_Id;
-- The "partial" invariant procedure of Par_Typ
Par_Typ : Entity_Id;
-- The suitable view of the parent type used in the substitution of
-- type attributes.
begin
if not Present (Priv_Typ) and then not Present (Full_Typ) then
return;
end if;
-- When the type inheriting the class-wide invariant is a concurrent
-- type, use the corresponding record type because it contains all
-- primitive operations of the concurrent type and allows for proper
-- substitution.
if Is_Concurrent_Type (T) then
Deriv_Typ := Corresponding_Record_Type (T);
else
Deriv_Typ := T;
end if;
pragma Assert (Present (Deriv_Typ));
-- Determine which rep item chain to use. Precedence is given to that
-- of the parent type's partial view since it usually carries all the
-- class-wide invariants.
if Present (Priv_Typ) then
Prag := First_Rep_Item (Priv_Typ);
else
Prag := First_Rep_Item (Full_Typ);
end if;
while Present (Prag) loop
if Nkind (Prag) = N_Pragma
and then Pragma_Name (Prag) = Name_Invariant
then
-- Nothing to do if the pragma was already processed
if Contains (Pragmas_Seen, Prag) then
return;
-- Nothing to do when the caller requests the processing of all
-- inherited class-wide invariants, but the pragma does not
-- fall in this category.
elsif not Class_Present (Prag) then
return;
end if;
-- Extract the arguments of the invariant pragma
Prag_Typ_Arg := First (Pragma_Argument_Associations (Prag));
Prag_Expr_Arg := Next (Prag_Typ_Arg);
Prag_Expr := Expression_Copy (Prag_Expr_Arg);
Prag_Typ := Get_Pragma_Arg (Prag_Typ_Arg);
-- The pragma applies to the partial view of the parent type
if Present (Priv_Typ)
and then Entity (Prag_Typ) = Priv_Typ
then
Par_Typ := Priv_Typ;
-- The pragma applies to the full view of the parent type
elsif Present (Full_Typ)
and then Entity (Prag_Typ) = Full_Typ
then
Par_Typ := Full_Typ;
-- Otherwise the pragma does not belong to the parent type and
-- should not be considered.
else
return;
end if;
-- Perform the following substitutions:
-- * Replace a reference to the _object parameter of the
-- parent type's partial invariant procedure with a
-- reference to the _object parameter of the derived
-- type's full invariant procedure.
-- * Replace a reference to a discriminant of the parent type
-- with a suitable value from the point of view of the
-- derived type.
-- * Replace a call to an overridden parent primitive with a
-- call to the overriding derived type primitive.
-- * Replace a call to an inherited parent primitive with a
-- call to the internally-generated inherited derived type
-- primitive.
Expr := New_Copy_Tree (Prag_Expr);
-- The parent type must have a "partial" invariant procedure
-- because class-wide invariants are captured exclusively by
-- it.
Par_Proc := Partial_Invariant_Procedure (Par_Typ);
pragma Assert (Present (Par_Proc));
Replace_References
(Expr => Expr,
Par_Typ => Par_Typ,
Deriv_Typ => Deriv_Typ,
Par_Obj => First_Formal (Par_Proc),
Deriv_Obj => Obj_Id);
Add_Invariant_Check (Prag, Expr, Checks, Inherited => True);
end if;
Next_Rep_Item (Prag);
end loop;
end Add_Inherited_Invariants;
------------------------------
-- Add_Interface_Invariants --
------------------------------
procedure Add_Interface_Invariants
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id)
is
Iface_Elmt : Elmt_Id;
Ifaces : Elist_Id;
begin
-- Generate an invariant check for each class-wide invariant coming
-- from all interfaces implemented by type T.
if Is_Tagged_Type (T) then
Collect_Interfaces (T, Ifaces);
-- Process the class-wide invariants of all implemented interfaces
Iface_Elmt := First_Elmt (Ifaces);
while Present (Iface_Elmt) loop
-- The Full_Typ parameter is intentionally left Empty because
-- interfaces are treated as the partial view of a private type
-- in order to achieve uniformity with the general case.
Add_Inherited_Invariants
(T => T,
Priv_Typ => Node (Iface_Elmt),
Full_Typ => Empty,
Obj_Id => Obj_Id,
Checks => Checks);
Next_Elmt (Iface_Elmt);
end loop;
end if;
end Add_Interface_Invariants;
-------------------------
-- Add_Invariant_Check --
-------------------------
procedure Add_Invariant_Check
(Prag : Node_Id;
Expr : Node_Id;
Checks : in out List_Id;
Inherited : Boolean := False)
is
Args : constant List_Id := Pragma_Argument_Associations (Prag);
Nam : constant Name_Id := Original_Aspect_Pragma_Name (Prag);
Ploc : constant Source_Ptr := Sloc (Prag);
Str_Arg : constant Node_Id := Next (Next (First (Args)));
Assoc : List_Id;
Str : String_Id;
begin
-- The invariant is ignored, nothing left to do
if Is_Ignored (Prag) then
null;
-- Otherwise the invariant is checked. Build a pragma Check to verify
-- the expression at run time.
else
Assoc := New_List (
Make_Pragma_Argument_Association (Ploc,
Expression => Make_Identifier (Ploc, Nam)),
Make_Pragma_Argument_Association (Ploc,
Expression => Expr));
-- Handle the String argument (if any)
if Present (Str_Arg) then
Str := Strval (Get_Pragma_Arg (Str_Arg));
-- When inheriting an invariant, modify the message from
-- "failed invariant" to "failed inherited invariant".
if Inherited then
String_To_Name_Buffer (Str);
if Name_Buffer (1 .. 16) = "failed invariant" then
Insert_Str_In_Name_Buffer ("inherited ", 8);
Str := String_From_Name_Buffer;
end if;
end if;
Append_To (Assoc,
Make_Pragma_Argument_Association (Ploc,
Expression => Make_String_Literal (Ploc, Str)));
end if;
-- Generate:
-- pragma Check (<Nam>, <Expr>, <Str>);
Append_New_To (Checks,
Make_Pragma (Ploc,
Chars => Name_Check,
Pragma_Argument_Associations => Assoc));
end if;
-- Output an info message when inheriting an invariant and the
-- listing option is enabled.
if Inherited and Opt.List_Inherited_Aspects then
Error_Msg_Sloc := Sloc (Prag);
Error_Msg_N
("info: & inherits `Invariant''Class` aspect from #?L?", Typ);
end if;
-- Add the pragma to the list of processed pragmas
Append_New_Elmt (Prag, Pragmas_Seen);
Produced_Check := True;
end Add_Invariant_Check;
---------------------------
-- Add_Parent_Invariants --
---------------------------
procedure Add_Parent_Invariants
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id)
is
Dummy_1 : Entity_Id;
Dummy_2 : Entity_Id;
Curr_Typ : Entity_Id;
-- The entity of the current type being examined
Full_Typ : Entity_Id;
-- The full view of Par_Typ
Par_Typ : Entity_Id;
-- The entity of the parent type
Priv_Typ : Entity_Id;
-- The partial view of Par_Typ
begin
-- Do not process array types because they cannot have true parent
-- types. This also prevents the generation of a duplicate invariant
-- check when the input type is an array base type because its Etype
-- denotes the first subtype, both of which share the same component
-- type.
if Is_Array_Type (T) then
return;
end if;
-- Climb the parent type chain
Curr_Typ := T;
loop
-- Do not consider subtypes as they inherit the invariants
-- from their base types.
Par_Typ := Base_Type (Etype (Curr_Typ));
-- Stop the climb once the root of the parent chain is
-- reached.
exit when Curr_Typ = Par_Typ;
-- Process the class-wide invariants of the parent type
Get_Views (Par_Typ, Priv_Typ, Full_Typ, Dummy_1, Dummy_2);
-- Process the elements of an array type
if Is_Array_Type (Full_Typ) then
Add_Array_Component_Invariants (Full_Typ, Obj_Id, Checks);
-- Process the components of a record type
elsif Ekind (Full_Typ) = E_Record_Type then
Add_Record_Component_Invariants (Full_Typ, Obj_Id, Checks);
end if;
Add_Inherited_Invariants
(T => T,
Priv_Typ => Priv_Typ,
Full_Typ => Full_Typ,
Obj_Id => Obj_Id,
Checks => Checks);
Curr_Typ := Par_Typ;
end loop;
end Add_Parent_Invariants;
------------------------
-- Add_Own_Invariants --
------------------------
procedure Add_Own_Invariants
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id;
Priv_Item : Node_Id := Empty)
is
Expr : Node_Id;
Prag : Node_Id;
Prag_Asp : Node_Id;
Prag_Expr : Node_Id;
Prag_Expr_Arg : Node_Id;
Prag_Typ : Node_Id;
Prag_Typ_Arg : Node_Id;
begin
if not Present (T) then
return;
end if;
Prag := First_Rep_Item (T);
while Present (Prag) loop
if Nkind (Prag) = N_Pragma
and then Pragma_Name (Prag) = Name_Invariant
then
-- Stop the traversal of the rep item chain once a specific
-- item is encountered.
if Present (Priv_Item) and then Prag = Priv_Item then
exit;
end if;
-- Nothing to do if the pragma was already processed
if Contains (Pragmas_Seen, Prag) then
return;
end if;
-- Extract the arguments of the invariant pragma
Prag_Typ_Arg := First (Pragma_Argument_Associations (Prag));
Prag_Expr_Arg := Next (Prag_Typ_Arg);
Prag_Expr := Get_Pragma_Arg (Prag_Expr_Arg);
Prag_Typ := Get_Pragma_Arg (Prag_Typ_Arg);
Prag_Asp := Corresponding_Aspect (Prag);
-- Verify the pragma belongs to T, otherwise the pragma applies
-- to a parent type in which case it will be processed later by
-- Add_Parent_Invariants or Add_Interface_Invariants.
if Entity (Prag_Typ) /= T then
return;
end if;
Expr := New_Copy_Tree (Prag_Expr);
-- Substitute all references to type T with references to the
-- _object formal parameter.
Replace_Type_References (Expr, T, Obj_Id);
-- Preanalyze the invariant expression to detect errors and at
-- the same time capture the visibility of the proper package
-- part.
Set_Parent (Expr, Parent (Prag_Expr));
Preanalyze_Assert_Expression (Expr, Any_Boolean);
-- Save a copy of the expression when T is tagged to detect
-- errors and capture the visibility of the proper package part
-- for the generation of inherited type invariants.
if Is_Tagged_Type (T) then
Set_Expression_Copy (Prag_Expr_Arg, New_Copy_Tree (Expr));
end if;
-- If the pragma comes from an aspect specification, replace
-- the saved expression because all type references must be
-- substituted for the call to Preanalyze_Spec_Expression in
-- Check_Aspect_At_xxx routines.
if Present (Prag_Asp) then
Set_Entity (Identifier (Prag_Asp), New_Copy_Tree (Expr));
end if;
Add_Invariant_Check (Prag, Expr, Checks);
end if;
Next_Rep_Item (Prag);
end loop;
end Add_Own_Invariants;
-------------------------------------
-- Add_Record_Component_Invariants --
-------------------------------------
procedure Add_Record_Component_Invariants
(T : Entity_Id;
Obj_Id : Entity_Id;
Checks : in out List_Id)
is
procedure Process_Component_List
(Comp_List : Node_Id;
CL_Checks : in out List_Id);
-- Generate invariant checks for all record components found in
-- component list Comp_List, including variant parts. All created
-- checks are added to list CL_Checks.
procedure Process_Record_Component
(Comp_Id : Entity_Id;
Comp_Checks : in out List_Id);
-- Generate an invariant check for a record component identified by
-- Comp_Id. All created checks are added to list Comp_Checks.
----------------------------
-- Process_Component_List --
----------------------------
procedure Process_Component_List
(Comp_List : Node_Id;
CL_Checks : in out List_Id)
is
Comp : Node_Id;
Var : Node_Id;
Var_Alts : List_Id := No_List;
Var_Checks : List_Id := No_List;
Var_Stmts : List_Id;
Produced_Variant_Check : Boolean := False;
-- This flag tracks whether the component has produced at least
-- one invariant check.
begin
-- Traverse the component items
Comp := First (Component_Items (Comp_List));
while Present (Comp) loop
if Nkind (Comp) = N_Component_Declaration then
-- Generate the component invariant check
Process_Record_Component
(Comp_Id => Defining_Entity (Comp),
Comp_Checks => CL_Checks);
end if;
Next (Comp);
end loop;
-- Traverse the variant part
if Present (Variant_Part (Comp_List)) then
Var := First (Variants (Variant_Part (Comp_List)));
while Present (Var) loop
Var_Checks := No_List;
-- Generate invariant checks for all components and variant
-- parts that qualify.
Process_Component_List
(Comp_List => Component_List (Var),
CL_Checks => Var_Checks);
-- The components of the current variant produced at least
-- one invariant check.
if Present (Var_Checks) then
Var_Stmts := Var_Checks;
Produced_Variant_Check := True;
-- Otherwise there are either no components with invariants,
-- assertions are disabled, or Assertion_Policy Ignore is in
-- effect.
else
Var_Stmts := New_List (Make_Null_Statement (Loc));
end if;
Append_New_To (Var_Alts,
Make_Case_Statement_Alternative (Loc,
Discrete_Choices =>
New_Copy_List (Discrete_Choices (Var)),
Statements => Var_Stmts));
Next (Var);
end loop;
-- Create a case statement which verifies the invariant checks
-- of a particular component list depending on the discriminant
-- values only when there is at least one real invariant check.
if Produced_Variant_Check then
Append_New_To (CL_Checks,
Make_Case_Statement (Loc,
Expression =>
Make_Selected_Component (Loc,
Prefix => New_Occurrence_Of (Obj_Id, Loc),
Selector_Name =>
New_Occurrence_Of
(Entity (Name (Variant_Part (Comp_List))), Loc)),
Alternatives => Var_Alts));
end if;
end if;
end Process_Component_List;
------------------------------
-- Process_Record_Component --
------------------------------
procedure Process_Record_Component
(Comp_Id : Entity_Id;
Comp_Checks : in out List_Id)
is
Comp_Typ : constant Entity_Id := Etype (Comp_Id);
Proc_Id : Entity_Id;
Produced_Component_Check : Boolean := False;
-- This flag tracks whether the component has produced at least
-- one invariant check.
begin
-- Nothing to do for internal component _parent. Note that it is
-- not desirable to check whether the component comes from source
-- because protected type components are relocated to an internal
-- corresponding record, but still need processing.
if Chars (Comp_Id) = Name_uParent then
return;
end if;
-- Verify the invariant of the component. Note that an access
-- type may have an invariant when it acts as the full view of a
-- private type and the invariant appears on the partial view. In
-- this case verify the access value itself.
if Has_Invariants (Comp_Typ) then
-- In GNATprove mode, the component invariants are checked by
-- other means. They should not be added to the record type
-- invariant procedure, so that the procedure can be used to
-- check the record type invariants if any.
if GNATprove_Mode then
null;
else
Proc_Id := Invariant_Procedure (Base_Type (Comp_Typ));
-- The component type should have an invariant procedure
-- if it has invariants of its own or inherits class-wide
-- invariants from parent or interface types.
pragma Assert (Present (Proc_Id));
-- Generate:
-- <Comp_Typ>Invariant (T (_object).<Comp_Id>);
-- Note that the invariant procedure may have a null body if
-- assertions are disabled or Assertion_Policy Ignore is in
-- effect.
if not Has_Null_Body (Proc_Id) then
Append_New_To (Comp_Checks,
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of (Proc_Id, Loc),
Parameter_Associations => New_List (
Make_Selected_Component (Loc,
Prefix =>
Unchecked_Convert_To
(T, New_Occurrence_Of (Obj_Id, Loc)),
Selector_Name =>
New_Occurrence_Of (Comp_Id, Loc)))));
end if;
end if;
Produced_Check := True;
Produced_Component_Check := True;
end if;
if Produced_Component_Check and then Has_Unchecked_Union (T) then
Error_Msg_NE
("invariants cannot be checked on components of "
& "unchecked_union type &??", Comp_Id, T);
end if;
end Process_Record_Component;
-- Local variables
Comps : Node_Id;
Def : Node_Id;
-- Start of processing for Add_Record_Component_Invariants
begin
-- An untagged derived type inherits the components of its parent
-- type. In order to avoid creating redundant invariant checks, do
-- not process the components now. Instead wait until the ultimate
-- parent of the untagged derivation chain is reached.
if not Is_Untagged_Derivation (T) then
Def := Type_Definition (Parent (T));
if Nkind (Def) = N_Derived_Type_Definition then
Def := Record_Extension_Part (Def);
end if;
pragma Assert (Nkind (Def) = N_Record_Definition);
Comps := Component_List (Def);
if Present (Comps) then
Process_Component_List
(Comp_List => Comps,
CL_Checks => Checks);
end if;
end if;
end Add_Record_Component_Invariants;
-- Local variables
Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
Saved_IGR : constant Node_Id := Ignored_Ghost_Region;
-- Save the Ghost-related attributes to restore on exit
Dummy : Entity_Id;
Priv_Item : Node_Id;
Proc_Body : Node_Id;
Proc_Body_Id : Entity_Id;
Proc_Decl : Node_Id;
Proc_Id : Entity_Id;
Stmts : List_Id := No_List;
CRec_Typ : Entity_Id := Empty;
-- The corresponding record type of Full_Typ
Full_Proc : Entity_Id := Empty;
-- The entity of the "full" invariant procedure
Full_Typ : Entity_Id := Empty;
-- The full view of the working type
Obj_Id : Entity_Id := Empty;
-- The _object formal parameter of the invariant procedure
Part_Proc : Entity_Id := Empty;
-- The entity of the "partial" invariant procedure
Priv_Typ : Entity_Id := Empty;
-- The partial view of the working type
Work_Typ : Entity_Id := Empty;
-- The working type
-- Start of processing for Build_Invariant_Procedure_Body
begin
Work_Typ := Typ;
-- Do not process the underlying full view of a private type. There is
-- no way to get back to the partial view, plus the body will be built
-- by the full view or the base type.
if Is_Underlying_Full_View (Work_Typ) then
return;
-- The input type denotes the implementation base type of a constrained
-- array type. Work with the first subtype as all invariant pragmas are
-- on its rep item chain.
elsif Ekind (Work_Typ) = E_Array_Type and then Is_Itype (Work_Typ) then
Work_Typ := First_Subtype (Work_Typ);
-- The input type denotes the corresponding record type of a protected
-- or task type. Work with the concurrent type because the corresponding
-- record type may not be visible to clients of the type.
elsif Ekind (Work_Typ) = E_Record_Type
and then Is_Concurrent_Record_Type (Work_Typ)
then
Work_Typ := Corresponding_Concurrent_Type (Work_Typ);
end if;
-- The working type may be subject to pragma Ghost. Set the mode now to
-- ensure that the invariant procedure is properly marked as Ghost.
Set_Ghost_Mode (Work_Typ);
-- The type must either have invariants of its own, inherit class-wide
-- invariants from parent types or interfaces, or be an array or record
-- type whose components have invariants.
pragma Assert (Has_Invariants (Work_Typ));
-- Interfaces are treated as the partial view of a private type in order
-- to achieve uniformity with the general case.
if Is_Interface (Work_Typ) then
Priv_Typ := Work_Typ;
-- Otherwise obtain both views of the type
else
Get_Views (Work_Typ, Priv_Typ, Full_Typ, Dummy, CRec_Typ);
end if;
-- The caller requests a body for the partial invariant procedure
if Partial_Invariant then
Full_Proc := Invariant_Procedure (Work_Typ);
Proc_Id := Partial_Invariant_Procedure (Work_Typ);
-- The "full" invariant procedure body was already created
if Present (Full_Proc)
and then Present
(Corresponding_Body (Unit_Declaration_Node (Full_Proc)))
then
-- This scenario happens only when the type is an untagged
-- derivation from a private parent and the underlying full
-- view was processed before the partial view.
pragma Assert
(Is_Untagged_Private_Derivation (Priv_Typ, Full_Typ));
-- Nothing to do because the processing of the underlying full
-- view already checked the invariants of the partial view.
goto Leave;
end if;
-- Create a declaration for the "partial" invariant procedure if it
-- is not available.
if No (Proc_Id) then
Build_Invariant_Procedure_Declaration
(Typ => Work_Typ,
Partial_Invariant => True);
Proc_Id := Partial_Invariant_Procedure (Work_Typ);
end if;
-- The caller requests a body for the "full" invariant procedure
else
Proc_Id := Invariant_Procedure (Work_Typ);
Part_Proc := Partial_Invariant_Procedure (Work_Typ);
-- Create a declaration for the "full" invariant procedure if it is
-- not available.
if No (Proc_Id) then
Build_Invariant_Procedure_Declaration (Work_Typ);
Proc_Id := Invariant_Procedure (Work_Typ);
end if;
end if;
-- At this point there should be an invariant procedure declaration
pragma Assert (Present (Proc_Id));
Proc_Decl := Unit_Declaration_Node (Proc_Id);
-- Nothing to do if the invariant procedure already has a body
if Present (Corresponding_Body (Proc_Decl)) then
goto Leave;
end if;
-- Emulate the environment of the invariant procedure by installing its
-- scope and formal parameters. Note that this is not needed, but having
-- the scope installed helps with the detection of invariant-related
-- errors.
Push_Scope (Proc_Id);
Install_Formals (Proc_Id);
Obj_Id := First_Formal (Proc_Id);
pragma Assert (Present (Obj_Id));
-- The "partial" invariant procedure verifies the invariants of the
-- partial view only.
if Partial_Invariant then
pragma Assert (Present (Priv_Typ));
Add_Own_Invariants
(T => Priv_Typ,
Obj_Id => Obj_Id,
Checks => Stmts);
-- Otherwise the "full" invariant procedure verifies the invariants of
-- the full view, all array or record components, as well as class-wide
-- invariants inherited from parent types or interfaces. In addition, it
-- indirectly verifies the invariants of the partial view by calling the
-- "partial" invariant procedure.
else
pragma Assert (Present (Full_Typ));
-- Check the invariants of the partial view by calling the "partial"
-- invariant procedure. Generate:
-- <Work_Typ>Partial_Invariant (_object);
if Present (Part_Proc) then
Append_New_To (Stmts,
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Part_Proc, Loc),
Parameter_Associations => New_List (
New_Occurrence_Of (Obj_Id, Loc))));
Produced_Check := True;
end if;
Priv_Item := Empty;
-- Derived subtypes do not have a partial view
if Present (Priv_Typ) then
-- The processing of the "full" invariant procedure intentionally
-- skips the partial view because a) this may result in changes of
-- visibility and b) lead to duplicate checks. However, when the
-- full view is the underlying full view of an untagged derived
-- type whose parent type is private, partial invariants appear on
-- the rep item chain of the partial view only.
-- package Pack_1 is
-- type Root ... is private;
-- private
-- <full view of Root>
-- end Pack_1;
-- with Pack_1;
-- package Pack_2 is
-- type Child is new Pack_1.Root with Type_Invariant => ...;
-- <underlying full view of Child>
-- end Pack_2;
-- As a result, the processing of the full view must also consider
-- all invariants of the partial view.
if Is_Untagged_Private_Derivation (Priv_Typ, Full_Typ) then
null;
-- Otherwise the invariants of the partial view are ignored
else
-- Note that the rep item chain is shared between the partial
-- and full views of a type. To avoid processing the invariants
-- of the partial view, signal the logic to stop when the first
-- rep item of the partial view has been reached.
Priv_Item := First_Rep_Item (Priv_Typ);
-- Ignore the invariants of the partial view by eliminating the
-- view.
Priv_Typ := Empty;
end if;
end if;
-- Process the invariants of the full view and in certain cases those
-- of the partial view. This also handles any invariants on array or
-- record components.
Add_Own_Invariants
(T => Priv_Typ,
Obj_Id => Obj_Id,
Checks => Stmts,
Priv_Item => Priv_Item);
Add_Own_Invariants
(T => Full_Typ,
Obj_Id => Obj_Id,
Checks => Stmts,
Priv_Item => Priv_Item);
-- Process the elements of an array type
if Is_Array_Type (Full_Typ) then
Add_Array_Component_Invariants (Full_Typ, Obj_Id, Stmts);
-- Process the components of a record type
elsif Ekind (Full_Typ) = E_Record_Type then
Add_Record_Component_Invariants (Full_Typ, Obj_Id, Stmts);
-- Process the components of a corresponding record
elsif Present (CRec_Typ) then
Add_Record_Component_Invariants (CRec_Typ, Obj_Id, Stmts);
end if;
-- Process the inherited class-wide invariants of all parent types.
-- This also handles any invariants on record components.
Add_Parent_Invariants (Full_Typ, Obj_Id, Stmts);
-- Process the inherited class-wide invariants of all implemented
-- interface types.
Add_Interface_Invariants (Full_Typ, Obj_Id, Stmts);
end if;
End_Scope;
-- At this point there should be at least one invariant check. If this
-- is not the case, then the invariant-related flags were not properly
-- set, or there is a missing invariant procedure on one of the array
-- or record components.
pragma Assert (Produced_Check);
-- Account for the case where assertions are disabled or all invariant
-- checks are subject to Assertion_Policy Ignore. Produce a completing
-- empty body.
if No (Stmts) then
Stmts := New_List (Make_Null_Statement (Loc));
end if;
-- Generate:
-- procedure <Work_Typ>[Partial_]Invariant (_object : <Obj_Typ>) is
-- begin
-- <Stmts>
-- end <Work_Typ>[Partial_]Invariant;
Proc_Body :=
Make_Subprogram_Body (Loc,
Specification =>
Copy_Subprogram_Spec (Parent (Proc_Id)),
Declarations => Empty_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stmts));
Proc_Body_Id := Defining_Entity (Proc_Body);
-- Perform minor decoration in case the body is not analyzed
Mutate_Ekind (Proc_Body_Id, E_Subprogram_Body);
Set_Etype (Proc_Body_Id, Standard_Void_Type);
Set_Scope (Proc_Body_Id, Current_Scope);
-- Link both spec and body to avoid generating duplicates
Set_Corresponding_Body (Proc_Decl, Proc_Body_Id);
Set_Corresponding_Spec (Proc_Body, Proc_Id);
-- The body should not be inserted into the tree when the context is
-- a generic unit because it is not part of the template. Note
-- that the body must still be generated in order to resolve the
-- invariants.
if Inside_A_Generic then
null;
-- Semi-insert the body into the tree for GNATprove by setting its
-- Parent field. This allows for proper upstream tree traversals.
elsif GNATprove_Mode then
Set_Parent (Proc_Body, Parent (Declaration_Node (Work_Typ)));
-- Otherwise the body is part of the freezing actions of the type
else
Append_Freeze_Action (Work_Typ, Proc_Body);
end if;
<<Leave>>
Restore_Ghost_Region (Saved_GM, Saved_IGR);
end Build_Invariant_Procedure_Body;
-------------------------------------------
-- Build_Invariant_Procedure_Declaration --
-------------------------------------------
-- WARNING: This routine manages Ghost regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- Ghost mode.
procedure Build_Invariant_Procedure_Declaration
(Typ : Entity_Id;
Partial_Invariant : Boolean := False)
is
Loc : constant Source_Ptr := Sloc (Typ);
Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
Saved_IGR : constant Node_Id := Ignored_Ghost_Region;
-- Save the Ghost-related attributes to restore on exit
Proc_Decl : Node_Id;
Proc_Id : Entity_Id;
Proc_Nam : Name_Id;
Typ_Decl : Node_Id;
CRec_Typ : Entity_Id;
-- The corresponding record type of Full_Typ
Full_Typ : Entity_Id;
-- The full view of working type
Obj_Id : Entity_Id;
-- The _object formal parameter of the invariant procedure
Obj_Typ : Entity_Id;
-- The type of the _object formal parameter
Priv_Typ : Entity_Id;
-- The partial view of working type
UFull_Typ : Entity_Id;
-- The underlying full view of Full_Typ
Work_Typ : Entity_Id;
-- The working type
begin
Work_Typ := Typ;
-- The input type denotes the implementation base type of a constrained
-- array type. Work with the first subtype as all invariant pragmas are
-- on its rep item chain.
if Ekind (Work_Typ) = E_Array_Type and then Is_Itype (Work_Typ) then
Work_Typ := First_Subtype (Work_Typ);
-- The input denotes the corresponding record type of a protected or a
-- task type. Work with the concurrent type because the corresponding
-- record type may not be visible to clients of the type.
elsif Ekind (Work_Typ) = E_Record_Type
and then Is_Concurrent_Record_Type (Work_Typ)
then
Work_Typ := Corresponding_Concurrent_Type (Work_Typ);
end if;
-- The working type may be subject to pragma Ghost. Set the mode now to
-- ensure that the invariant procedure is properly marked as Ghost.
Set_Ghost_Mode (Work_Typ);
-- The type must either have invariants of its own, inherit class-wide
-- invariants from parent or interface types, or be an array or record
-- type whose components have invariants.
pragma Assert (Has_Invariants (Work_Typ));
-- Nothing to do if the type already has a "partial" invariant procedure
if Partial_Invariant then
if Present (Partial_Invariant_Procedure (Work_Typ)) then
goto Leave;
end if;
-- Nothing to do if the type already has a "full" invariant procedure
elsif Present (Invariant_Procedure (Work_Typ)) then
goto Leave;
end if;
-- The caller requests the declaration of the "partial" invariant
-- procedure.
if Partial_Invariant then
Proc_Nam := New_External_Name (Chars (Work_Typ), "Partial_Invariant");
-- Otherwise the caller requests the declaration of the "full" invariant
-- procedure.
else
Proc_Nam := New_External_Name (Chars (Work_Typ), "Invariant");
end if;
Proc_Id := Make_Defining_Identifier (Loc, Chars => Proc_Nam);
-- Perform minor decoration in case the declaration is not analyzed
Mutate_Ekind (Proc_Id, E_Procedure);
Set_Etype (Proc_Id, Standard_Void_Type);
Set_Scope (Proc_Id, Current_Scope);
if Partial_Invariant then
Set_Is_Partial_Invariant_Procedure (Proc_Id);
Set_Partial_Invariant_Procedure (Work_Typ, Proc_Id);
else
Set_Is_Invariant_Procedure (Proc_Id);
Set_Invariant_Procedure (Work_Typ, Proc_Id);
end if;
-- The invariant procedure requires debug info when the invariants are
-- subject to Source Coverage Obligations.
if Generate_SCO then
Set_Debug_Info_Needed (Proc_Id);
end if;
-- Obtain all views of the input type
Get_Views (Work_Typ, Priv_Typ, Full_Typ, UFull_Typ, CRec_Typ);
-- Associate the invariant procedure and various flags with all views
Propagate_Invariant_Attributes (Priv_Typ, From_Typ => Work_Typ);
Propagate_Invariant_Attributes (Full_Typ, From_Typ => Work_Typ);
Propagate_Invariant_Attributes (UFull_Typ, From_Typ => Work_Typ);
Propagate_Invariant_Attributes (CRec_Typ, From_Typ => Work_Typ);
-- The declaration of the invariant procedure is inserted after the
-- declaration of the partial view as this allows for proper external
-- visibility.
if Present (Priv_Typ) then
Typ_Decl := Declaration_Node (Priv_Typ);
-- Anonymous arrays in object declarations have no explicit declaration
-- so use the related object declaration as the insertion point.
elsif Is_Itype (Work_Typ) and then Is_Array_Type (Work_Typ) then
Typ_Decl := Associated_Node_For_Itype (Work_Typ);
-- Derived types with the full view as parent do not have a partial
-- view. Insert the invariant procedure after the derived type.
else
Typ_Decl := Declaration_Node (Full_Typ);
end if;
-- The type should have a declarative node
pragma Assert (Present (Typ_Decl));
-- Create the formal parameter which emulates the variable-like behavior
-- of the current type instance.
Obj_Id := Make_Defining_Identifier (Loc, Chars => Name_uObject);
-- When generating an invariant procedure declaration for an abstract
-- type (including interfaces), use the class-wide type as the _object
-- type. This has several desirable effects:
-- * The invariant procedure does not become a primitive of the type.
-- This eliminates the need to either special case the treatment of
-- invariant procedures, or to make it a predefined primitive and
-- force every derived type to potentially provide an empty body.
-- * The invariant procedure does not need to be declared as abstract.
-- This allows for a proper body, which in turn avoids redundant
-- processing of the same invariants for types with multiple views.
-- * The class-wide type allows for calls to abstract primitives
-- within a nonabstract subprogram. The calls are treated as
-- dispatching and require additional processing when they are
-- remapped to call primitives of derived types. See routine
-- Replace_References for details.
if Is_Abstract_Type (Work_Typ) then
Obj_Typ := Class_Wide_Type (Work_Typ);
else
Obj_Typ := Work_Typ;
end if;
-- Perform minor decoration in case the declaration is not analyzed
Mutate_Ekind (Obj_Id, E_In_Parameter);
Set_Etype (Obj_Id, Obj_Typ);
Set_Scope (Obj_Id, Proc_Id);
Set_First_Entity (Proc_Id, Obj_Id);
Set_Last_Entity (Proc_Id, Obj_Id);
-- Generate:
-- procedure <Work_Typ>[Partial_]Invariant (_object : <Obj_Typ>);
Proc_Decl :=
Make_Subprogram_Declaration (Loc,
Specification =>
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Proc_Id,
Parameter_Specifications => New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => Obj_Id,
Parameter_Type => New_Occurrence_Of (Obj_Typ, Loc)))));
-- The declaration should not be inserted into the tree when the context
-- is a generic unit because it is not part of the template.
if Inside_A_Generic then
null;
-- Semi-insert the declaration into the tree for GNATprove by setting
-- its Parent field. This allows for proper upstream tree traversals.
elsif GNATprove_Mode then
Set_Parent (Proc_Decl, Parent (Typ_Decl));
-- Otherwise insert the declaration
else
pragma Assert (Present (Typ_Decl));
Insert_After_And_Analyze (Typ_Decl, Proc_Decl);
end if;
<<Leave>>
Restore_Ghost_Region (Saved_GM, Saved_IGR);
end Build_Invariant_Procedure_Declaration;
--------------------------
-- Build_Procedure_Form --
--------------------------
procedure Build_Procedure_Form (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Subp : constant Entity_Id := Defining_Entity (N);
Func_Formal : Entity_Id;
Proc_Formals : List_Id;
Proc_Decl : Node_Id;
begin
-- No action needed if this transformation was already done, or in case
-- of subprogram renaming declarations.
if Nkind (Specification (N)) = N_Procedure_Specification
or else Nkind (N) = N_Subprogram_Renaming_Declaration
then
return;
end if;
-- Ditto when dealing with an expression function, where both the
-- original expression and the generated declaration end up being
-- expanded here.
if Rewritten_For_C (Subp) then
return;
end if;
Proc_Formals := New_List;
-- Create a list of formal parameters with the same types as the
-- function.
Func_Formal := First_Formal (Subp);
while Present (Func_Formal) loop
Append_To (Proc_Formals,
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Chars (Func_Formal)),
Parameter_Type =>
New_Occurrence_Of (Etype (Func_Formal), Loc)));
Next_Formal (Func_Formal);
end loop;
-- Add an extra out parameter to carry the function result
Append_To (Proc_Formals,
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_UP_RESULT),
Out_Present => True,
Parameter_Type => New_Occurrence_Of (Etype (Subp), Loc)));
-- The new procedure declaration is inserted before the function
-- declaration. The processing in Build_Procedure_Body_Form relies on
-- this order. Note that we insert before because in the case of a
-- function body with no separate spec, we do not want to insert the
-- new spec after the body which will later get rewritten.
Proc_Decl :=
Make_Subprogram_Declaration (Loc,
Specification =>
Make_Procedure_Specification (Loc,
Defining_Unit_Name =>
Make_Defining_Identifier (Loc, Chars (Subp)),
Parameter_Specifications => Proc_Formals));
Insert_Before_And_Analyze (Unit_Declaration_Node (Subp), Proc_Decl);
-- Entity of procedure must remain invisible so that it does not
-- overload subsequent references to the original function.
Set_Is_Immediately_Visible (Defining_Entity (Proc_Decl), False);
-- Mark the function as having a procedure form and link the function
-- and its internally built procedure.
Set_Rewritten_For_C (Subp);
Set_Corresponding_Procedure (Subp, Defining_Entity (Proc_Decl));
Set_Corresponding_Function (Defining_Entity (Proc_Decl), Subp);
end Build_Procedure_Form;
------------------------
-- Build_Runtime_Call --
------------------------
function Build_Runtime_Call (Loc : Source_Ptr; RE : RE_Id) return Node_Id is
begin
-- If entity is not available, we can skip making the call (this avoids
-- junk duplicated error messages in a number of cases).
if not RTE_Available (RE) then
return Make_Null_Statement (Loc);
else
return
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (RTE (RE), Loc));
end if;
end Build_Runtime_Call;
------------------------
-- Build_SS_Mark_Call --
------------------------
function Build_SS_Mark_Call
(Loc : Source_Ptr;
Mark : Entity_Id) return Node_Id
is
begin
-- Generate:
-- Mark : constant Mark_Id := SS_Mark;
return
Make_Object_Declaration (Loc,
Defining_Identifier => Mark,
Constant_Present => True,
Object_Definition =>
New_Occurrence_Of (RTE (RE_Mark_Id), Loc),
Expression =>
Make_Function_Call (Loc,
Name => New_Occurrence_Of (RTE (RE_SS_Mark), Loc)));
end Build_SS_Mark_Call;
---------------------------
-- Build_SS_Release_Call --
---------------------------
function Build_SS_Release_Call
(Loc : Source_Ptr;
Mark : Entity_Id) return Node_Id
is
begin
-- Generate:
-- SS_Release (Mark);
return
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of (RTE (RE_SS_Release), Loc),
Parameter_Associations => New_List (
New_Occurrence_Of (Mark, Loc)));
end Build_SS_Release_Call;
----------------------------
-- Build_Task_Array_Image --
----------------------------
-- This function generates the body for a function that constructs the
-- image string for a task that is an array component. The function is
-- local to the init proc for the array type, and is called for each one
-- of the components. The constructed image has the form of an indexed
-- component, whose prefix is the outer variable of the array type.
-- The n-dimensional array type has known indexes Index, Index2...
-- Id_Ref is an indexed component form created by the enclosing init proc.
-- Its successive indexes are Val1, Val2, ... which are the loop variables
-- in the loops that call the individual task init proc on each component.
-- The generated function has the following structure:
-- function F return String is
-- Pref : string renames Task_Name;
-- T1 : String := Index1'Image (Val1);
-- ...
-- Tn : String := indexn'image (Valn);
-- Len : Integer := T1'Length + ... + Tn'Length + n + 1;
-- -- Len includes commas and the end parentheses.
-- Res : String (1..Len);
-- Pos : Integer := Pref'Length;
--
-- begin
-- Res (1 .. Pos) := Pref;
-- Pos := Pos + 1;
-- Res (Pos) := '(';
-- Pos := Pos + 1;
-- Res (Pos .. Pos + T1'Length - 1) := T1;
-- Pos := Pos + T1'Length;
-- Res (Pos) := '.';
-- Pos := Pos + 1;
-- ...
-- Res (Pos .. Pos + Tn'Length - 1) := Tn;
-- Res (Len) := ')';
--
-- return Res;
-- end F;
--
-- Needless to say, multidimensional arrays of tasks are rare enough that
-- the bulkiness of this code is not really a concern.
function Build_Task_Array_Image
(Loc : Source_Ptr;
Id_Ref : Node_Id;
A_Type : Entity_Id;
Dyn : Boolean := False) return Node_Id
is
Dims : constant Nat := Number_Dimensions (A_Type);
-- Number of dimensions for array of tasks
Temps : array (1 .. Dims) of Entity_Id;
-- Array of temporaries to hold string for each index
Indx : Node_Id;
-- Index expression
Len : Entity_Id;
-- Total length of generated name
Pos : Entity_Id;
-- Running index for substring assignments
Pref : constant Entity_Id := Make_Temporary (Loc, 'P');
-- Name of enclosing variable, prefix of resulting name
Res : Entity_Id;
-- String to hold result
Val : Node_Id;
-- Value of successive indexes
Sum : Node_Id;
-- Expression to compute total size of string
T : Entity_Id;
-- Entity for name at one index position
Decls : constant List_Id := New_List;
Stats : constant List_Id := New_List;
begin
-- For a dynamic task, the name comes from the target variable. For a
-- static one it is a formal of the enclosing init proc.
if Dyn then
Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Pref,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Expression =>
Make_String_Literal (Loc,
Strval => String_From_Name_Buffer)));
else
Append_To (Decls,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Pref,
Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
Name => Make_Identifier (Loc, Name_uTask_Name)));
end if;
Indx := First_Index (A_Type);
Val := First (Expressions (Id_Ref));
for J in 1 .. Dims loop
T := Make_Temporary (Loc, 'T');
Temps (J) := T;
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => T,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Image,
Prefix => New_Occurrence_Of (Etype (Indx), Loc),
Expressions => New_List (New_Copy_Tree (Val)))));
Next_Index (Indx);
Next (Val);
end loop;
Sum := Make_Integer_Literal (Loc, Dims + 1);
Sum :=
Make_Op_Add (Loc,
Left_Opnd => Sum,
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix => New_Occurrence_Of (Pref, Loc),
Expressions => New_List (Make_Integer_Literal (Loc, 1))));
for J in 1 .. Dims loop
Sum :=
Make_Op_Add (Loc,
Left_Opnd => Sum,
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix =>
New_Occurrence_Of (Temps (J), Loc),
Expressions => New_List (Make_Integer_Literal (Loc, 1))));
end loop;
Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
Set_Character_Literal_Name (Char_Code (Character'Pos ('(')));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name =>
Make_Indexed_Component (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
Expression =>
Make_Character_Literal (Loc,
Chars => Name_Find,
Char_Literal_Value => UI_From_Int (Character'Pos ('(')))));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd => Make_Integer_Literal (Loc, 1))));
for J in 1 .. Dims loop
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name =>
Make_Slice (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Discrete_Range =>
Make_Range (Loc,
Low_Bound => New_Occurrence_Of (Pos, Loc),
High_Bound =>
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix =>
New_Occurrence_Of (Temps (J), Loc),
Expressions =>
New_List (Make_Integer_Literal (Loc, 1)))),
Right_Opnd => Make_Integer_Literal (Loc, 1)))),
Expression => New_Occurrence_Of (Temps (J), Loc)));
if J < Dims then
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix => New_Occurrence_Of (Temps (J), Loc),
Expressions =>
New_List (Make_Integer_Literal (Loc, 1))))));
Set_Character_Literal_Name (Char_Code (Character'Pos (',')));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => Make_Indexed_Component (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
Expression =>
Make_Character_Literal (Loc,
Chars => Name_Find,
Char_Literal_Value => UI_From_Int (Character'Pos (',')))));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd => Make_Integer_Literal (Loc, 1))));
end if;
end loop;
Set_Character_Literal_Name (Char_Code (Character'Pos (')')));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name =>
Make_Indexed_Component (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Expressions => New_List (New_Occurrence_Of (Len, Loc))),
Expression =>
Make_Character_Literal (Loc,
Chars => Name_Find,
Char_Literal_Value => UI_From_Int (Character'Pos (')')))));
return Build_Task_Image_Function (Loc, Decls, Stats, Res);
end Build_Task_Array_Image;
----------------------------
-- Build_Task_Image_Decls --
----------------------------
function Build_Task_Image_Decls
(Loc : Source_Ptr;
Id_Ref : Node_Id;
A_Type : Entity_Id;
In_Init_Proc : Boolean := False) return List_Id
is
Decls : constant List_Id := New_List;
T_Id : Entity_Id := Empty;
Decl : Node_Id;
Expr : Node_Id := Empty;
Fun : Node_Id := Empty;
Is_Dyn : constant Boolean :=
Nkind (Parent (Id_Ref)) = N_Assignment_Statement
and then
Nkind (Expression (Parent (Id_Ref))) = N_Allocator;
begin
-- If Discard_Names or No_Implicit_Heap_Allocations are in effect,
-- generate a dummy declaration only.
if Restriction_Active (No_Implicit_Heap_Allocations)
or else Global_Discard_Names
then
T_Id := Make_Temporary (Loc, 'J');
Name_Len := 0;
return
New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => T_Id,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Expression =>
Make_String_Literal (Loc,
Strval => String_From_Name_Buffer)));
else
if Nkind (Id_Ref) = N_Identifier
or else Nkind (Id_Ref) = N_Defining_Identifier
then
-- For a simple variable, the image of the task is built from
-- the name of the variable. To avoid possible conflict with the
-- anonymous type created for a single protected object, add a
-- numeric suffix.
T_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (Id_Ref), 'T', 1));
Get_Name_String (Chars (Id_Ref));
Expr :=
Make_String_Literal (Loc,
Strval => String_From_Name_Buffer);
elsif Nkind (Id_Ref) = N_Selected_Component then
T_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (Selector_Name (Id_Ref)), 'T'));
Fun := Build_Task_Record_Image (Loc, Id_Ref, Is_Dyn);
elsif Nkind (Id_Ref) = N_Indexed_Component then
T_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (A_Type), 'N'));
Fun := Build_Task_Array_Image (Loc, Id_Ref, A_Type, Is_Dyn);
end if;
end if;
if Present (Fun) then
Append (Fun, Decls);
Expr := Make_Function_Call (Loc,
Name => New_Occurrence_Of (Defining_Entity (Fun), Loc));
if not In_Init_Proc then
Set_Uses_Sec_Stack (Defining_Entity (Fun));
end if;
end if;
Decl := Make_Object_Declaration (Loc,
Defining_Identifier => T_Id,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Constant_Present => True,
Expression => Expr);
Append (Decl, Decls);
return Decls;
end Build_Task_Image_Decls;
-------------------------------
-- Build_Task_Image_Function --
-------------------------------
function Build_Task_Image_Function
(Loc : Source_Ptr;
Decls : List_Id;
Stats : List_Id;
Res : Entity_Id) return Node_Id
is
Spec : Node_Id;
begin
Append_To (Stats,
Make_Simple_Return_Statement (Loc,
Expression => New_Occurrence_Of (Res, Loc)));
Spec := Make_Function_Specification (Loc,
Defining_Unit_Name => Make_Temporary (Loc, 'F'),
Result_Definition => New_Occurrence_Of (Standard_String, Loc));
-- Calls to 'Image use the secondary stack, which must be cleaned up
-- after the task name is built.
return Make_Subprogram_Body (Loc,
Specification => Spec,
Declarations => Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc, Statements => Stats));
end Build_Task_Image_Function;
-----------------------------
-- Build_Task_Image_Prefix --
-----------------------------
procedure Build_Task_Image_Prefix
(Loc : Source_Ptr;
Len : out Entity_Id;
Res : out Entity_Id;
Pos : out Entity_Id;
Prefix : Entity_Id;
Sum : Node_Id;
Decls : List_Id;
Stats : List_Id)
is
begin
Len := Make_Temporary (Loc, 'L', Sum);
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Len,
Object_Definition => New_Occurrence_Of (Standard_Integer, Loc),
Expression => Sum));
Res := Make_Temporary (Loc, 'R');
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Res,
Object_Definition =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints =>
New_List (
Make_Range (Loc,
Low_Bound => Make_Integer_Literal (Loc, 1),
High_Bound => New_Occurrence_Of (Len, Loc)))))));
-- Indicate that the result is an internal temporary, so it does not
-- receive a bogus initialization when declaration is expanded. This
-- is both efficient, and prevents anomalies in the handling of
-- dynamic objects on the secondary stack.
Set_Is_Internal (Res);
Pos := Make_Temporary (Loc, 'P');
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Pos,
Object_Definition => New_Occurrence_Of (Standard_Integer, Loc)));
-- Pos := Prefix'Length;
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix => New_Occurrence_Of (Prefix, Loc),
Expressions => New_List (Make_Integer_Literal (Loc, 1)))));
-- Res (1 .. Pos) := Prefix;
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name =>
Make_Slice (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Discrete_Range =>
Make_Range (Loc,
Low_Bound => Make_Integer_Literal (Loc, 1),
High_Bound => New_Occurrence_Of (Pos, Loc))),
Expression => New_Occurrence_Of (Prefix, Loc)));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd => Make_Integer_Literal (Loc, 1))));
end Build_Task_Image_Prefix;
-----------------------------
-- Build_Task_Record_Image --
-----------------------------
function Build_Task_Record_Image
(Loc : Source_Ptr;
Id_Ref : Node_Id;
Dyn : Boolean := False) return Node_Id
is
Len : Entity_Id;
-- Total length of generated name
Pos : Entity_Id;
-- Index into result
Res : Entity_Id;
-- String to hold result
Pref : constant Entity_Id := Make_Temporary (Loc, 'P');
-- Name of enclosing variable, prefix of resulting name
Sum : Node_Id;
-- Expression to compute total size of string
Sel : Entity_Id;
-- Entity for selector name
Decls : constant List_Id := New_List;
Stats : constant List_Id := New_List;
begin
-- For a dynamic task, the name comes from the target variable. For a
-- static one it is a formal of the enclosing init proc.
if Dyn then
Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Pref,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Expression =>
Make_String_Literal (Loc,
Strval => String_From_Name_Buffer)));
else
Append_To (Decls,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Pref,
Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
Name => Make_Identifier (Loc, Name_uTask_Name)));
end if;
Sel := Make_Temporary (Loc, 'S');
Get_Name_String (Chars (Selector_Name (Id_Ref)));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Sel,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Expression =>
Make_String_Literal (Loc,
Strval => String_From_Name_Buffer)));
Sum := Make_Integer_Literal (Loc, Nat (Name_Len + 1));
Sum :=
Make_Op_Add (Loc,
Left_Opnd => Sum,
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix =>
New_Occurrence_Of (Pref, Loc),
Expressions => New_List (Make_Integer_Literal (Loc, 1))));
Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
Set_Character_Literal_Name (Char_Code (Character'Pos ('.')));
-- Res (Pos) := '.';
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => Make_Indexed_Component (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
Expression =>
Make_Character_Literal (Loc,
Chars => Name_Find,
Char_Literal_Value =>
UI_From_Int (Character'Pos ('.')))));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd => Make_Integer_Literal (Loc, 1))));
-- Res (Pos .. Len) := Selector;
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => Make_Slice (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Discrete_Range =>
Make_Range (Loc,
Low_Bound => New_Occurrence_Of (Pos, Loc),
High_Bound => New_Occurrence_Of (Len, Loc))),
Expression => New_Occurrence_Of (Sel, Loc)));
return Build_Task_Image_Function (Loc, Decls, Stats, Res);
end Build_Task_Record_Image;
---------------------------------------
-- Build_Transient_Object_Statements --
---------------------------------------
procedure Build_Transient_Object_Statements
(Obj_Decl : Node_Id;
Fin_Call : out Node_Id;
Hook_Assign : out Node_Id;
Hook_Clear : out Node_Id;
Hook_Decl : out Node_Id;
Ptr_Decl : out Node_Id;
Finalize_Obj : Boolean := True)
is
Loc : constant Source_Ptr := Sloc (Obj_Decl);
Obj_Id : constant Entity_Id := Defining_Entity (Obj_Decl);
Obj_Typ : constant Entity_Id := Base_Type (Etype (Obj_Id));
Desig_Typ : Entity_Id;
Hook_Expr : Node_Id;
Hook_Id : Entity_Id;
Obj_Ref : Node_Id;
Ptr_Typ : Entity_Id;
begin
-- Recover the type of the object
Desig_Typ := Obj_Typ;
if Is_Access_Type (Desig_Typ) then
Desig_Typ := Available_View (Designated_Type (Desig_Typ));
end if;
-- Create an access type which provides a reference to the transient
-- object. Generate:
-- type Ptr_Typ is access all Desig_Typ;
Ptr_Typ := Make_Temporary (Loc, 'A');
Mutate_Ekind (Ptr_Typ, E_General_Access_Type);
Set_Directly_Designated_Type (Ptr_Typ, Desig_Typ);
Ptr_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Ptr_Typ,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present => True,
Subtype_Indication => New_Occurrence_Of (Desig_Typ, Loc)));
-- Create a temporary check which acts as a hook to the transient
-- object. Generate:
-- Hook : Ptr_Typ := null;
Hook_Id := Make_Temporary (Loc, 'T');
Mutate_Ekind (Hook_Id, E_Variable);
Set_Etype (Hook_Id, Ptr_Typ);
Hook_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Hook_Id,
Object_Definition => New_Occurrence_Of (Ptr_Typ, Loc),
Expression => Make_Null (Loc));
-- Mark the temporary as a hook. This signals the machinery in
-- Build_Finalizer to recognize this special case.
Set_Status_Flag_Or_Transient_Decl (Hook_Id, Obj_Decl);
-- Hook the transient object to the temporary. Generate:
-- Hook := Ptr_Typ (Obj_Id);
-- <or>
-- Hool := Obj_Id'Unrestricted_Access;
if Is_Access_Type (Obj_Typ) then
Hook_Expr :=
Unchecked_Convert_To (Ptr_Typ, New_Occurrence_Of (Obj_Id, Loc));
else
Hook_Expr :=
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Obj_Id, Loc),
Attribute_Name => Name_Unrestricted_Access);
end if;
Hook_Assign :=
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Hook_Id, Loc),
Expression => Hook_Expr);
-- Crear the hook prior to finalizing the object. Generate:
-- Hook := null;
Hook_Clear :=
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Hook_Id, Loc),
Expression => Make_Null (Loc));
-- Finalize the object. Generate:
-- [Deep_]Finalize (Obj_Ref[.all]);
if Finalize_Obj then
Obj_Ref := New_Occurrence_Of (Obj_Id, Loc);
if Is_Access_Type (Obj_Typ) then
Obj_Ref := Make_Explicit_Dereference (Loc, Obj_Ref);
Set_Etype (Obj_Ref, Desig_Typ);
end if;
Fin_Call :=
Make_Final_Call
(Obj_Ref => Obj_Ref,
Typ => Desig_Typ);
-- Otherwise finalize the hook. Generate:
-- [Deep_]Finalize (Hook.all);
else
Fin_Call :=
Make_Final_Call (
Obj_Ref =>
Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (Hook_Id, Loc)),
Typ => Desig_Typ);
end if;
end Build_Transient_Object_Statements;
-----------------------------
-- Check_Float_Op_Overflow --
-----------------------------
procedure Check_Float_Op_Overflow (N : Node_Id) is
begin
-- Return if no check needed
if not Is_Floating_Point_Type (Etype (N))
or else not (Do_Overflow_Check (N) and then Check_Float_Overflow)
-- In CodePeer_Mode, rely on the overflow check flag being set instead
-- and do not expand the code for float overflow checking.
or else CodePeer_Mode
then
return;
end if;
-- Otherwise we replace the expression by
-- do Tnn : constant ftype := expression;
-- constraint_error when not Tnn'Valid;
-- in Tnn;
declare
Loc : constant Source_Ptr := Sloc (N);
Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N);
Typ : constant Entity_Id := Etype (N);
begin
-- Turn off the Do_Overflow_Check flag, since we are doing that work
-- right here. We also set the node as analyzed to prevent infinite
-- recursion from repeating the operation in the expansion.
Set_Do_Overflow_Check (N, False);
Set_Analyzed (N, True);
-- Do the rewrite to include the check
Rewrite (N,
Make_Expression_With_Actions (Loc,
Actions => New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => Tnn,
Object_Definition => New_Occurrence_Of (Typ, Loc),
Constant_Present => True,
Expression => Relocate_Node (N)),
Make_Raise_Constraint_Error (Loc,
Condition =>
Make_Op_Not (Loc,
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Tnn, Loc),
Attribute_Name => Name_Valid)),
Reason => CE_Overflow_Check_Failed)),
Expression => New_Occurrence_Of (Tnn, Loc)));
Analyze_And_Resolve (N, Typ);
end;
end Check_Float_Op_Overflow;
----------------------------------
-- Component_May_Be_Bit_Aligned --
----------------------------------
function Component_May_Be_Bit_Aligned (Comp : Entity_Id) return Boolean is
UT : Entity_Id;
begin
-- If no component clause, then everything is fine, since the back end
-- never misaligns from byte boundaries by default, even if there is a
-- pragma Pack for the record.
if No (Comp) or else No (Component_Clause (Comp)) then
return False;
end if;
UT := Underlying_Type (Etype (Comp));
-- It is only array and record types that cause trouble
if not Is_Record_Type (UT) and then not Is_Array_Type (UT) then
return False;
-- If we know that we have a small (at most the maximum integer size)
-- record or bit-packed array, then everything is fine, since the back
-- end can handle these cases correctly.
elsif Esize (Comp) <= System_Max_Integer_Size
and then (Is_Record_Type (UT) or else Is_Bit_Packed_Array (UT))
then
return False;
elsif not Known_Normalized_First_Bit (Comp) then
return True;
-- Otherwise if the component is not byte aligned, we know we have the
-- nasty unaligned case.
elsif Normalized_First_Bit (Comp) /= Uint_0
or else Esize (Comp) mod System_Storage_Unit /= Uint_0
then
return True;
-- If we are large and byte aligned, then OK at this level
else
return False;
end if;
end Component_May_Be_Bit_Aligned;
-------------------------------
-- Convert_To_Actual_Subtype --
-------------------------------
procedure Convert_To_Actual_Subtype (Exp : Node_Id) is
Act_ST : Entity_Id;
begin
Act_ST := Get_Actual_Subtype (Exp);
if Act_ST = Etype (Exp) then
return;
else
Rewrite (Exp, Convert_To (Act_ST, Relocate_Node (Exp)));
Analyze_And_Resolve (Exp, Act_ST);
end if;
end Convert_To_Actual_Subtype;
-----------------------------------
-- Corresponding_Runtime_Package --
-----------------------------------
function Corresponding_Runtime_Package (Typ : Entity_Id) return RTU_Id is
function Has_One_Entry_And_No_Queue (T : Entity_Id) return Boolean;
-- Return True if protected type T has one entry and the maximum queue
-- length is one.
--------------------------------
-- Has_One_Entry_And_No_Queue --
--------------------------------
function Has_One_Entry_And_No_Queue (T : Entity_Id) return Boolean is
Item : Entity_Id;
Is_First : Boolean := True;
begin
Item := First_Entity (T);
while Present (Item) loop
if Is_Entry (Item) then
-- The protected type has more than one entry
if not Is_First then
return False;
end if;
-- The queue length is not one
if not Restriction_Active (No_Entry_Queue)
and then Get_Max_Queue_Length (Item) /= Uint_1
then
return False;
end if;
Is_First := False;
end if;
Next_Entity (Item);
end loop;
return True;
end Has_One_Entry_And_No_Queue;
-- Local variables
Pkg_Id : RTU_Id := RTU_Null;
-- Start of processing for Corresponding_Runtime_Package
begin
pragma Assert (Is_Concurrent_Type (Typ));
if Is_Protected_Type (Typ) then
if Has_Entries (Typ)
-- A protected type without entries that covers an interface and
-- overrides the abstract routines with protected procedures is
-- considered equivalent to a protected type with entries in the
-- context of dispatching select statements. It is sufficient to
-- check for the presence of an interface list in the declaration
-- node to recognize this case.
or else Present (Interface_List (Parent (Typ)))
-- Protected types with interrupt handlers (when not using a
-- restricted profile) are also considered equivalent to
-- protected types with entries. The types which are used
-- (Static_Interrupt_Protection and Dynamic_Interrupt_Protection)
-- are derived from Protection_Entries.
or else (Has_Attach_Handler (Typ) and then not Restricted_Profile)
or else Has_Interrupt_Handler (Typ)
then
if Abort_Allowed
or else Restriction_Active (No_Select_Statements) = False
or else not Has_One_Entry_And_No_Queue (Typ)
or else (Has_Attach_Handler (Typ)
and then not Restricted_Profile)
then
Pkg_Id := System_Tasking_Protected_Objects_Entries;
else
Pkg_Id := System_Tasking_Protected_Objects_Single_Entry;
end if;
else
Pkg_Id := System_Tasking_Protected_Objects;
end if;
end if;
return Pkg_Id;
end Corresponding_Runtime_Package;
-----------------------------------
-- Current_Sem_Unit_Declarations --
-----------------------------------
function Current_Sem_Unit_Declarations return List_Id is
U : Node_Id := Unit (Cunit (Current_Sem_Unit));
Decls : List_Id;
begin
-- If the current unit is a package body, locate the visible
-- declarations of the package spec.
if Nkind (U) = N_Package_Body then
U := Unit (Library_Unit (Cunit (Current_Sem_Unit)));
end if;
if Nkind (U) = N_Package_Declaration then
U := Specification (U);
Decls := Visible_Declarations (U);
if No (Decls) then
Decls := New_List;
Set_Visible_Declarations (U, Decls);
end if;
else
Decls := Declarations (U);
if No (Decls) then
Decls := New_List;
Set_Declarations (U, Decls);
end if;
end if;
return Decls;
end Current_Sem_Unit_Declarations;
-----------------------
-- Duplicate_Subexpr --
-----------------------
function Duplicate_Subexpr
(Exp : Node_Id;
Name_Req : Boolean := False;
Renaming_Req : Boolean := False) return Node_Id
is
begin
Remove_Side_Effects (Exp, Name_Req, Renaming_Req);
return New_Copy_Tree (Exp);
end Duplicate_Subexpr;
---------------------------------
-- Duplicate_Subexpr_No_Checks --
---------------------------------
function Duplicate_Subexpr_No_Checks
(Exp : Node_Id;
Name_Req : Boolean := False;
Renaming_Req : Boolean := False;
Related_Id : Entity_Id := Empty;
Is_Low_Bound : Boolean := False;
Is_High_Bound : Boolean := False) return Node_Id
is
New_Exp : Node_Id;
begin
Remove_Side_Effects
(Exp => Exp,
Name_Req => Name_Req,
Renaming_Req => Renaming_Req,
Related_Id => Related_Id,
Is_Low_Bound => Is_Low_Bound,
Is_High_Bound => Is_High_Bound);
New_Exp := New_Copy_Tree (Exp);
Remove_Checks (New_Exp);
return New_Exp;
end Duplicate_Subexpr_No_Checks;
-----------------------------------
-- Duplicate_Subexpr_Move_Checks --
-----------------------------------
function Duplicate_Subexpr_Move_Checks
(Exp : Node_Id;
Name_Req : Boolean := False;
Renaming_Req : Boolean := False) return Node_Id
is
New_Exp : Node_Id;
begin
Remove_Side_Effects (Exp, Name_Req, Renaming_Req);
New_Exp := New_Copy_Tree (Exp);
Remove_Checks (Exp);
return New_Exp;
end Duplicate_Subexpr_Move_Checks;
-------------------------
-- Enclosing_Init_Proc --
-------------------------
function Enclosing_Init_Proc return Entity_Id is
S : Entity_Id;
begin
S := Current_Scope;
while Present (S) and then S /= Standard_Standard loop
if Is_Init_Proc (S) then
return S;
else
S := Scope (S);
end if;
end loop;
return Empty;
end Enclosing_Init_Proc;
--------------------
-- Ensure_Defined --
--------------------
procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is
IR : Node_Id;
begin
-- An itype reference must only be created if this is a local itype, so
-- that gigi can elaborate it on the proper objstack.
if Is_Itype (Typ) and then Scope (Typ) = Current_Scope then
IR := Make_Itype_Reference (Sloc (N));
Set_Itype (IR, Typ);
Insert_Action (N, IR);
end if;
end Ensure_Defined;
--------------------
-- Entry_Names_OK --
--------------------
function Entry_Names_OK return Boolean is
begin
return
not Restricted_Profile
and then not Global_Discard_Names
and then not Restriction_Active (No_Implicit_Heap_Allocations)
and then not Restriction_Active (No_Local_Allocators);
end Entry_Names_OK;
-------------------
-- Evaluate_Name --
-------------------
procedure Evaluate_Name (Nam : Node_Id) is
begin
case Nkind (Nam) is
-- For an aggregate, force its evaluation
when N_Aggregate =>
Force_Evaluation (Nam);
-- For an attribute reference or an indexed component, evaluate the
-- prefix, which is itself a name, recursively, and then force the
-- evaluation of all the subscripts (or attribute expressions).
when N_Attribute_Reference
| N_Indexed_Component
=>
Evaluate_Name (Prefix (Nam));
declare
E : Node_Id;
begin
E := First (Expressions (Nam));
while Present (E) loop
Force_Evaluation (E);
if Is_Rewrite_Substitution (E) then
Set_Do_Range_Check
(E, Do_Range_Check (Original_Node (E)));
end if;
Next (E);
end loop;
end;
-- For an explicit dereference, we simply force the evaluation of
-- the name expression. The dereference provides a value that is the
-- address for the renamed object, and it is precisely this value
-- that we want to preserve.
when N_Explicit_Dereference =>
Force_Evaluation (Prefix (Nam));
-- For a function call, we evaluate the call; same for an operator
when N_Function_Call
| N_Op
=>
Force_Evaluation (Nam);
-- For a qualified expression, we evaluate the expression
when N_Qualified_Expression =>
Evaluate_Name (Expression (Nam));
-- For a selected component, we simply evaluate the prefix
when N_Selected_Component =>
Evaluate_Name (Prefix (Nam));
-- For a slice, we evaluate the prefix, as for the indexed component
-- case and then, if there is a range present, either directly or as
-- the constraint of a discrete subtype indication, we evaluate the
-- two bounds of this range.
when N_Slice =>
Evaluate_Name (Prefix (Nam));
Evaluate_Slice_Bounds (Nam);
-- For a type conversion, the expression of the conversion must be
-- the name of an object, and we simply need to evaluate this name.
when N_Type_Conversion =>
Evaluate_Name (Expression (Nam));
-- The remaining cases are direct name and character literal. In all
-- these cases, we do nothing, since we want to reevaluate each time
-- the renamed object is used. ??? There are more remaining cases, at
-- least in the GNATprove_Mode, where this routine is called in more
-- contexts than in GNAT.
when others =>
null;
end case;
end Evaluate_Name;
---------------------------
-- Evaluate_Slice_Bounds --
---------------------------
procedure Evaluate_Slice_Bounds (Slice : Node_Id) is
DR : constant Node_Id := Discrete_Range (Slice);
Constr : Node_Id;
Rexpr : Node_Id;
begin
if Nkind (DR) = N_Range then
Force_Evaluation (Low_Bound (DR));
Force_Evaluation (High_Bound (DR));
elsif Nkind (DR) = N_Subtype_Indication then
Constr := Constraint (DR);
if Nkind (Constr) = N_Range_Constraint then
Rexpr := Range_Expression (Constr);
Force_Evaluation (Low_Bound (Rexpr));
Force_Evaluation (High_Bound (Rexpr));
end if;
end if;
end Evaluate_Slice_Bounds;
---------------------
-- Evolve_And_Then --
---------------------
procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is
begin
if No (Cond) then
Cond := Cond1;
else
Cond :=
Make_And_Then (Sloc (Cond1),
Left_Opnd => Cond,
Right_Opnd => Cond1);
end if;
end Evolve_And_Then;
--------------------
-- Evolve_Or_Else --
--------------------
procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is
begin
if No (Cond) then
Cond := Cond1;
else
Cond :=
Make_Or_Else (Sloc (Cond1),
Left_Opnd => Cond,
Right_Opnd => Cond1);
end if;
end Evolve_Or_Else;
-------------------------------
-- Expand_Sliding_Conversion --
-------------------------------
procedure Expand_Sliding_Conversion (N : Node_Id; Arr_Typ : Entity_Id) is
pragma Assert (Is_Array_Type (Arr_Typ)
and then not Is_Constrained (Arr_Typ)
and then Is_Fixed_Lower_Bound_Array_Subtype (Arr_Typ));
Constraints : List_Id;
Index : Node_Id := First_Index (Arr_Typ);
Loc : constant Source_Ptr := Sloc (N);
Subt_Decl : Node_Id;
Subt : Entity_Id;
Subt_Low : Node_Id;
Subt_High : Node_Id;
Act_Subt : Entity_Id;
Act_Index : Node_Id;
Act_Low : Node_Id;
Act_High : Node_Id;
Adjust_Incr : Node_Id;
Dimension : Int := 0;
All_FLBs_Match : Boolean := True;
begin
-- This procedure is called during semantic analysis, and we only expand
-- a sliding conversion when Expander_Active, to avoid doing it during
-- preanalysis (which can lead to problems with the target subtype not
-- getting properly expanded during later full analysis). Also, sliding
-- should never be needed for string literals, because their bounds are
-- determined directly based on the fixed lower bound of Arr_Typ and
-- their length.
if Expander_Active and then Nkind (N) /= N_String_Literal then
Constraints := New_List;
Act_Subt := Get_Actual_Subtype (N);
Act_Index := First_Index (Act_Subt);
-- Loop over the indexes of the fixed-lower-bound array type or
-- subtype to build up an index constraint for constructing the
-- subtype that will be the target of a conversion of the array
-- object that may need a sliding conversion.
while Present (Index) loop
pragma Assert (Present (Act_Index));
Dimension := Dimension + 1;
Get_Index_Bounds (Act_Index, Act_Low, Act_High);
-- If Index defines a normal unconstrained range (range <>),
-- then we will simply use the bounds of the actual subtype's
-- corresponding index range.
if not Is_Fixed_Lower_Bound_Index_Subtype (Etype (Index)) then
Subt_Low := Act_Low;
Subt_High := Act_High;
-- Otherwise, a range will be created with a low bound given by
-- the fixed lower bound of the array subtype's index, and with
-- high bound given by (Actual'Length + fixed lower bound - 1).
else
if Nkind (Index) = N_Subtype_Indication then
Subt_Low :=
New_Copy_Tree
(Low_Bound (Range_Expression (Constraint (Index))));
else
pragma Assert (Nkind (Index) = N_Range);
Subt_Low := New_Copy_Tree (Low_Bound (Index));
end if;
-- If either we have a nonstatic lower bound, or the target and
-- source subtypes are statically known to have unequal lower
-- bounds, then we will need to make a subtype conversion to
-- slide the bounds. However, if all of the indexes' lower
-- bounds are static and known to be equal (the common case),
-- then no conversion will be needed, and we'll end up not
-- creating the subtype or the conversion (though we still
-- build up the index constraint, which will simply be unused).
if not (Compile_Time_Known_Value (Subt_Low)
and then Compile_Time_Known_Value (Act_Low))
or else Expr_Value (Subt_Low) /= Expr_Value (Act_Low)
then
All_FLBs_Match := False;
end if;
-- Apply 'Pos to lower bound, which may be of an enumeration
-- type, before subtracting.
Adjust_Incr :=
Make_Op_Subtract (Loc,
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Etype (Act_Index), Loc),
Attribute_Name =>
Name_Pos,
Expressions =>
New_List (New_Copy_Tree (Subt_Low))),
Make_Integer_Literal (Loc, 1));
-- Apply 'Val to the result of adding the increment to the
-- length, to handle indexes of enumeration types.
Subt_High :=
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Etype (Act_Index), Loc),
Attribute_Name =>
Name_Val,
Expressions =>
New_List (Make_Op_Add (Loc,
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Act_Subt, Loc),
Attribute_Name =>
Name_Length,
Expressions =>
New_List
(Make_Integer_Literal
(Loc, Dimension))),
Adjust_Incr)));
end if;
Append (Make_Range (Loc, Subt_Low, Subt_High), Constraints);
Next (Index);
Next (Act_Index);
end loop;
-- If for each index with a fixed lower bound (FLB), the lower bound
-- of the corresponding index of the actual subtype is statically
-- known be equal to the FLB, then a sliding conversion isn't needed
-- at all, so just return without building a subtype or conversion.
if All_FLBs_Match then
return;
end if;
-- A sliding conversion is needed, so create the target subtype using
-- the index constraint created above, and rewrite the expression
-- as a conversion to that subtype.
Subt := Make_Temporary (Loc, 'S', Related_Node => N);
Set_Is_Internal (Subt);
Subt_Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Subt,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark =>
New_Occurrence_Of (Arr_Typ, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => Constraints)));
Mark_Rewrite_Insertion (Subt_Decl);
-- The actual subtype is an Itype, so we analyze the declaration,
-- but do not attach it to the tree.
Set_Parent (Subt_Decl, N);
Set_Is_Itype (Subt);
Analyze (Subt_Decl, Suppress => All_Checks);
Set_Associated_Node_For_Itype (Subt, N);
Set_Has_Delayed_Freeze (Subt, False);
-- We need to freeze the actual subtype immediately. This is needed
-- because otherwise this Itype will not get frozen at all, and it is
-- always safe to freeze on creation because any associated types
-- must be frozen at this point.
Freeze_Itype (Subt, N);
Rewrite (N,
Make_Type_Conversion (Loc,
Subtype_Mark =>
New_Occurrence_Of (Subt, Loc),
Expression => Relocate_Node (N)));
Analyze (N);
end if;
end Expand_Sliding_Conversion;
-----------------------------------------
-- Expand_Static_Predicates_In_Choices --
-----------------------------------------
procedure Expand_Static_Predicates_In_Choices (N : Node_Id) is
pragma Assert (Nkind (N) in N_Case_Statement_Alternative | N_Variant);
Choices : List_Id := Discrete_Choices (N);
Choice : Node_Id;
Next_C : Node_Id;
P : Node_Id;
C : Node_Id;
begin
-- If this is an "others" alternative, we need to process any static
-- predicates in its Others_Discrete_Choices.
if Nkind (First (Choices)) = N_Others_Choice then
Choices := Others_Discrete_Choices (First (Choices));
end if;
Choice := First (Choices);
while Present (Choice) loop
Next_C := Next (Choice);
-- Check for name of subtype with static predicate
if Is_Entity_Name (Choice)
and then Is_Type (Entity (Choice))
and then Has_Predicates (Entity (Choice))
then
-- Loop through entries in predicate list, converting to choices
-- and inserting in the list before the current choice. Note that
-- if the list is empty, corresponding to a False predicate, then
-- no choices are inserted.
P := First (Static_Discrete_Predicate (Entity (Choice)));
while Present (P) loop
-- If low bound and high bounds are equal, copy simple choice
if Expr_Value (Low_Bound (P)) = Expr_Value (High_Bound (P)) then
C := New_Copy (Low_Bound (P));
-- Otherwise copy a range
else
C := New_Copy (P);
end if;
-- Change Sloc to referencing choice (rather than the Sloc of
-- the predicate declaration element itself).
Set_Sloc (C, Sloc (Choice));
Insert_Before (Choice, C);
Next (P);
end loop;
-- Delete the predicated entry
Remove (Choice);
end if;
-- Move to next choice to check
Choice := Next_C;
end loop;
Set_Has_SP_Choice (N, False);
end Expand_Static_Predicates_In_Choices;
------------------------------
-- Expand_Subtype_From_Expr --
------------------------------
-- This function is applicable for both static and dynamic allocation of
-- objects which are constrained by an initial expression. Basically it
-- transforms an unconstrained subtype indication into a constrained one.
-- The expression may also be transformed in certain cases in order to
-- avoid multiple evaluation. In the static allocation case, the general
-- scheme is:
-- Val : T := Expr;
-- is transformed into
-- Val : Constrained_Subtype_Of_T := Maybe_Modified_Expr;
--
-- Here are the main cases :
--
-- <if Expr is a Slice>
-- Val : T ([Index_Subtype (Expr)]) := Expr;
--
-- <elsif Expr is a String Literal>
-- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr;
--
-- <elsif Expr is Constrained>
-- subtype T is Type_Of_Expr
-- Val : T := Expr;
--
-- <elsif Expr is an entity_name>
-- Val : T (constraints taken from Expr) := Expr;
--
-- <else>
-- type Axxx is access all T;
-- Rval : Axxx := Expr'ref;
-- Val : T (constraints taken from Rval) := Rval.all;
-- ??? note: when the Expression is allocated in the secondary stack
-- we could use it directly instead of copying it by declaring
-- Val : T (...) renames Rval.all
procedure Expand_Subtype_From_Expr
(N : Node_Id;
Unc_Type : Entity_Id;
Subtype_Indic : Node_Id;
Exp : Node_Id;
Related_Id : Entity_Id := Empty)
is
Loc : constant Source_Ptr := Sloc (N);
Exp_Typ : constant Entity_Id := Etype (Exp);
T : Entity_Id;
begin
-- In general we cannot build the subtype if expansion is disabled,
-- because internal entities may not have been defined. However, to
-- avoid some cascaded errors, we try to continue when the expression is
-- an array (or string), because it is safe to compute the bounds. It is
-- in fact required to do so even in a generic context, because there
-- may be constants that depend on the bounds of a string literal, both
-- standard string types and more generally arrays of characters.
-- In GNATprove mode, these extra subtypes are not needed, unless Exp is
-- a static expression. In that case, the subtype will be constrained
-- while the original type might be unconstrained, so expanding the type
-- is necessary both for passing legality checks in GNAT and for precise
-- analysis in GNATprove.
if GNATprove_Mode and then not Is_Static_Expression (Exp) then
return;
end if;
if not Expander_Active
and then (No (Etype (Exp)) or else not Is_String_Type (Etype (Exp)))
then
return;
end if;
if Nkind (Exp) = N_Slice then
declare
Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ));
begin
Rewrite (Subtype_Indic,
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Unc_Type, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => New_List
(New_Occurrence_Of (Slice_Type, Loc)))));
-- This subtype indication may be used later for constraint checks
-- we better make sure that if a variable was used as a bound of
-- the original slice, its value is frozen.
Evaluate_Slice_Bounds (Exp);
end;
elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then
Rewrite (Subtype_Indic,
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Unc_Type, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => New_List (
Make_Literal_Range (Loc,
Literal_Typ => Exp_Typ)))));
-- If the type of the expression is an internally generated type it
-- may not be necessary to create a new subtype. However there are two
-- exceptions: references to the current instances, and aliased array
-- object declarations for which the back end has to create a template.
elsif Is_Constrained (Exp_Typ)
and then not Is_Class_Wide_Type (Unc_Type)
and then
(Nkind (N) /= N_Object_Declaration
or else not Is_Entity_Name (Expression (N))
or else not Comes_From_Source (Entity (Expression (N)))
or else not Is_Array_Type (Exp_Typ)
or else not Aliased_Present (N))
then
if Is_Itype (Exp_Typ) then
-- Within an initialization procedure, a selected component
-- denotes a component of the enclosing record, and it appears as
-- an actual in a call to its own initialization procedure. If
-- this component depends on the outer discriminant, we must
-- generate the proper actual subtype for it.
if Nkind (Exp) = N_Selected_Component
and then Within_Init_Proc
then
declare
Decl : constant Node_Id :=
Build_Actual_Subtype_Of_Component (Exp_Typ, Exp);
begin
if Present (Decl) then
Insert_Action (N, Decl);
T := Defining_Identifier (Decl);
else
T := Exp_Typ;
end if;
end;
-- No need to generate a new subtype
else
T := Exp_Typ;
end if;
else
T := Make_Temporary (Loc, 'T');
Insert_Action (N,
Make_Subtype_Declaration (Loc,
Defining_Identifier => T,
Subtype_Indication => New_Occurrence_Of (Exp_Typ, Loc)));
-- This type is marked as an itype even though it has an explicit
-- declaration since otherwise Is_Generic_Actual_Type can get
-- set, resulting in the generation of spurious errors. (See
-- sem_ch8.Analyze_Package_Renaming and sem_type.covers)
Set_Is_Itype (T);
Set_Associated_Node_For_Itype (T, Exp);
end if;
Rewrite (Subtype_Indic, New_Occurrence_Of (T, Loc));
-- Nothing needs to be done for private types with unknown discriminants
-- if the underlying type is not an unconstrained composite type or it
-- is an unchecked union.
elsif Is_Private_Type (Unc_Type)
and then Has_Unknown_Discriminants (Unc_Type)
and then (not Is_Composite_Type (Underlying_Type (Unc_Type))
or else Is_Constrained (Underlying_Type (Unc_Type))
or else Is_Unchecked_Union (Underlying_Type (Unc_Type)))
then
null;
-- Case of derived type with unknown discriminants where the parent type
-- also has unknown discriminants.
elsif Is_Record_Type (Unc_Type)
and then not Is_Class_Wide_Type (Unc_Type)
and then Has_Unknown_Discriminants (Unc_Type)
and then Has_Unknown_Discriminants (Underlying_Type (Unc_Type))
then
-- Nothing to be done if no underlying record view available
-- If this is a limited type derived from a type with unknown
-- discriminants, do not expand either, so that subsequent expansion
-- of the call can add build-in-place parameters to call.
if No (Underlying_Record_View (Unc_Type))
or else Is_Limited_Type (Unc_Type)
then
null;
-- Otherwise use the Underlying_Record_View to create the proper
-- constrained subtype for an object of a derived type with unknown
-- discriminants.
else
Remove_Side_Effects (Exp);
Rewrite (Subtype_Indic,
Make_Subtype_From_Expr (Exp, Underlying_Record_View (Unc_Type)));
end if;
-- Renamings of class-wide interface types require no equivalent
-- constrained type declarations because we only need to reference
-- the tag component associated with the interface. The same is
-- presumably true for class-wide types in general, so this test
-- is broadened to include all class-wide renamings, which also
-- avoids cases of unbounded recursion in Remove_Side_Effects.
-- (Is this really correct, or are there some cases of class-wide
-- renamings that require action in this procedure???)
elsif Present (N)
and then Nkind (N) = N_Object_Renaming_Declaration
and then Is_Class_Wide_Type (Unc_Type)
then
null;
-- In Ada 95 nothing to be done if the type of the expression is limited
-- because in this case the expression cannot be copied, and its use can
-- only be by reference.
-- In Ada 2005 the context can be an object declaration whose expression
-- is a function that returns in place. If the nominal subtype has
-- unknown discriminants, the call still provides constraints on the
-- object, and we have to create an actual subtype from it.
-- If the type is class-wide, the expression is dynamically tagged and
-- we do not create an actual subtype either. Ditto for an interface.
-- For now this applies only if the type is immutably limited, and the
-- function being called is build-in-place. This will have to be revised
-- when build-in-place functions are generalized to other types.
elsif Is_Limited_View (Exp_Typ)
and then
(Is_Class_Wide_Type (Exp_Typ)
or else Is_Interface (Exp_Typ)
or else not Has_Unknown_Discriminants (Exp_Typ)
or else not Is_Composite_Type (Unc_Type))
then
null;
-- For limited objects initialized with build-in-place function calls,
-- nothing to be done; otherwise we prematurely introduce an N_Reference
-- node in the expression initializing the object, which breaks the
-- circuitry that detects and adds the additional arguments to the
-- called function.
elsif Is_Build_In_Place_Function_Call (Exp) then
null;
-- If the expression is an uninitialized aggregate, no need to build
-- a subtype from the expression, because this may require the use of
-- dynamic memory to create the object.
elsif Is_Uninitialized_Aggregate (Exp, Exp_Typ) then
Rewrite (Subtype_Indic, New_Occurrence_Of (Etype (Exp), Sloc (N)));
if Nkind (N) = N_Object_Declaration then
Set_Expression (N, Empty);
Set_No_Initialization (N);
end if;
else
Remove_Side_Effects (Exp);
Rewrite (Subtype_Indic,
Make_Subtype_From_Expr (Exp, Unc_Type, Related_Id));
end if;
end Expand_Subtype_From_Expr;
---------------------------------------------
-- Expression_Contains_Primitives_Calls_Of --
---------------------------------------------
function Expression_Contains_Primitives_Calls_Of
(Expr : Node_Id;
Typ : Entity_Id) return Boolean
is
U_Typ : constant Entity_Id := Unique_Entity (Typ);
Calls_OK : Boolean := False;
-- This flag is set to True when expression Expr contains at least one
-- call to a nondispatching primitive function of Typ.
function Search_Primitive_Calls (N : Node_Id) return Traverse_Result;
-- Search for nondispatching calls to primitive functions of type Typ
----------------------------
-- Search_Primitive_Calls --
----------------------------
function Search_Primitive_Calls (N : Node_Id) return Traverse_Result is
Disp_Typ : Entity_Id;
Subp : Entity_Id;
begin
-- Detect a function call that could denote a nondispatching
-- primitive of the input type.
if Nkind (N) = N_Function_Call
and then Is_Entity_Name (Name (N))
then
Subp := Entity (Name (N));
-- Do not consider function calls with a controlling argument, as
-- those are always dispatching calls.
if Is_Dispatching_Operation (Subp)
and then No (Controlling_Argument (N))
then
Disp_Typ := Find_Dispatching_Type (Subp);
-- To qualify as a suitable primitive, the dispatching type of
-- the function must be the input type.
if Present (Disp_Typ)
and then Unique_Entity (Disp_Typ) = U_Typ
then
Calls_OK := True;
-- There is no need to continue the traversal, as one such
-- call suffices.
return Abandon;
end if;
end if;
end if;
return OK;
end Search_Primitive_Calls;
procedure Search_Calls is new Traverse_Proc (Search_Primitive_Calls);
-- Start of processing for Expression_Contains_Primitives_Calls_Of_Type
begin
Search_Calls (Expr);
return Calls_OK;
end Expression_Contains_Primitives_Calls_Of;
----------------------
-- Finalize_Address --
----------------------
function Finalize_Address (Typ : Entity_Id) return Entity_Id is
Btyp : constant Entity_Id := Base_Type (Typ);
Utyp : Entity_Id := Typ;
begin
-- Handle protected class-wide or task class-wide types
if Is_Class_Wide_Type (Utyp) then
if Is_Concurrent_Type (Root_Type (Utyp)) then
Utyp := Root_Type (Utyp);
elsif Is_Private_Type (Root_Type (Utyp))
and then Present (Full_View (Root_Type (Utyp)))
and then Is_Concurrent_Type (Full_View (Root_Type (Utyp)))
then
Utyp := Full_View (Root_Type (Utyp));
end if;
end if;
-- Handle private types
if Is_Private_Type (Utyp) and then Present (Full_View (Utyp)) then
Utyp := Full_View (Utyp);
end if;
-- Handle protected and task types
if Is_Concurrent_Type (Utyp)
and then Present (Corresponding_Record_Type (Utyp))
then
Utyp := Corresponding_Record_Type (Utyp);
end if;
Utyp := Underlying_Type (Base_Type (Utyp));
-- Deal with untagged derivation of private views. If the parent is
-- now known to be protected, the finalization routine is the one
-- defined on the corresponding record of the ancestor (corresponding
-- records do not automatically inherit operations, but maybe they
-- should???)
if Is_Untagged_Derivation (Btyp) then
if Is_Protected_Type (Btyp) then
Utyp := Corresponding_Record_Type (Root_Type (Btyp));
else
Utyp := Underlying_Type (Root_Type (Btyp));
if Is_Protected_Type (Utyp) then
Utyp := Corresponding_Record_Type (Utyp);
end if;
end if;
end if;
-- If the underlying_type is a subtype, we are dealing with the
-- completion of a private type. We need to access the base type and
-- generate a conversion to it.
if Utyp /= Base_Type (Utyp) then
pragma Assert (Is_Private_Type (Typ));
Utyp := Base_Type (Utyp);
end if;
-- When dealing with an internally built full view for a type with
-- unknown discriminants, use the original record type.
if Is_Underlying_Record_View (Utyp) then
Utyp := Etype (Utyp);
end if;
return TSS (Utyp, TSS_Finalize_Address);
end Finalize_Address;
------------------------
-- Find_Interface_ADT --
------------------------
function Find_Interface_ADT
(T : Entity_Id;
Iface : Entity_Id) return Elmt_Id
is
ADT : Elmt_Id;
Typ : Entity_Id := T;
begin
pragma Assert (Is_Interface (Iface));
-- Handle private types
if Has_Private_Declaration (Typ) and then Present (Full_View (Typ)) then
Typ := Full_View (Typ);
end if;
-- Handle access types
if Is_Access_Type (Typ) then
Typ := Designated_Type (Typ);
end if;
-- Handle task and protected types implementing interfaces
if Is_Concurrent_Type (Typ) then
Typ := Corresponding_Record_Type (Typ);
end if;
pragma Assert
(not Is_Class_Wide_Type (Typ)
and then Ekind (Typ) /= E_Incomplete_Type);
if Is_Ancestor (Iface, Typ, Use_Full_View => True) then
return First_Elmt (Access_Disp_Table (Typ));
else
ADT := Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Typ))));
while Present (ADT)
and then Present (Related_Type (Node (ADT)))
and then Related_Type (Node (ADT)) /= Iface
and then not Is_Ancestor (Iface, Related_Type (Node (ADT)),
Use_Full_View => True)
loop
Next_Elmt (ADT);
end loop;
pragma Assert (Present (Related_Type (Node (ADT))));
return ADT;
end if;
end Find_Interface_ADT;
------------------------
-- Find_Interface_Tag --
------------------------
function Find_Interface_Tag
(T : Entity_Id;
Iface : Entity_Id) return Entity_Id
is
AI_Tag : Entity_Id := Empty;
Found : Boolean := False;
Typ : Entity_Id := T;
procedure Find_Tag (Typ : Entity_Id);
-- Internal subprogram used to recursively climb to the ancestors
--------------
-- Find_Tag --
--------------
procedure Find_Tag (Typ : Entity_Id) is
AI_Elmt : Elmt_Id;
AI : Node_Id;
begin
-- This routine does not handle the case in which the interface is an
-- ancestor of Typ. That case is handled by the enclosing subprogram.
pragma Assert (Typ /= Iface);
-- Climb to the root type handling private types
if Present (Full_View (Etype (Typ))) then
if Full_View (Etype (Typ)) /= Typ then
Find_Tag (Full_View (Etype (Typ)));
end if;
elsif Etype (Typ) /= Typ then
Find_Tag (Etype (Typ));
end if;
-- Traverse the list of interfaces implemented by the type
if not Found
and then Present (Interfaces (Typ))
and then not (Is_Empty_Elmt_List (Interfaces (Typ)))
then
-- Skip the tag associated with the primary table
AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
pragma Assert (Present (AI_Tag));
AI_Elmt := First_Elmt (Interfaces (Typ));
while Present (AI_Elmt) loop
AI := Node (AI_Elmt);
if AI = Iface
or else Is_Ancestor (Iface, AI, Use_Full_View => True)
then
Found := True;
return;
end if;
AI_Tag := Next_Tag_Component (AI_Tag);
Next_Elmt (AI_Elmt);
end loop;
end if;
end Find_Tag;
-- Start of processing for Find_Interface_Tag
begin
pragma Assert (Is_Interface (Iface));
-- Handle access types
if Is_Access_Type (Typ) then
Typ := Designated_Type (Typ);
end if;
-- Handle class-wide types
if Is_Class_Wide_Type (Typ) then
Typ := Root_Type (Typ);
end if;
-- Handle private types
if Has_Private_Declaration (Typ) and then Present (Full_View (Typ)) then
Typ := Full_View (Typ);
end if;
-- Handle entities from the limited view
if Ekind (Typ) = E_Incomplete_Type then
pragma Assert (Present (Non_Limited_View (Typ)));
Typ := Non_Limited_View (Typ);
end if;
-- Handle task and protected types implementing interfaces
if Is_Concurrent_Type (Typ) then
Typ := Corresponding_Record_Type (Typ);
end if;
-- If the interface is an ancestor of the type, then it shared the
-- primary dispatch table.
if Is_Ancestor (Iface, Typ, Use_Full_View => True) then
return First_Tag_Component (Typ);
-- Otherwise we need to search for its associated tag component
else
Find_Tag (Typ);
return AI_Tag;
end if;
end Find_Interface_Tag;
---------------------------
-- Find_Optional_Prim_Op --
---------------------------
function Find_Optional_Prim_Op
(T : Entity_Id; Name : Name_Id) return Entity_Id
is
Prim : Elmt_Id;
Typ : Entity_Id := T;
Op : Entity_Id;
begin
if Is_Class_Wide_Type (Typ) then
Typ := Root_Type (Typ);
end if;
Typ := Underlying_Type (Typ);
-- Loop through primitive operations
Prim := First_Elmt (Primitive_Operations (Typ));
while Present (Prim) loop
Op := Node (Prim);
-- We can retrieve primitive operations by name if it is an internal
-- name. For equality we must check that both of its operands have
-- the same type, to avoid confusion with user-defined equalities
-- than may have a asymmetric signature.
exit when Chars (Op) = Name
and then
(Name /= Name_Op_Eq
or else Etype (First_Formal (Op)) = Etype (Last_Formal (Op)));
Next_Elmt (Prim);
end loop;
return Node (Prim); -- Empty if not found
end Find_Optional_Prim_Op;
---------------------------
-- Find_Optional_Prim_Op --
---------------------------
function Find_Optional_Prim_Op
(T : Entity_Id;
Name : TSS_Name_Type) return Entity_Id
is
Inher_Op : Entity_Id := Empty;
Own_Op : Entity_Id := Empty;
Prim_Elmt : Elmt_Id;
Prim_Id : Entity_Id;
Typ : Entity_Id := T;
begin
if Is_Class_Wide_Type (Typ) then
Typ := Root_Type (Typ);
end if;
Typ := Underlying_Type (Typ);
-- This search is based on the assertion that the dispatching version
-- of the TSS routine always precedes the real primitive.
Prim_Elmt := First_Elmt (Primitive_Operations (Typ));
while Present (Prim_Elmt) loop
Prim_Id := Node (Prim_Elmt);
if Is_TSS (Prim_Id, Name) then
if Present (Alias (Prim_Id)) then
Inher_Op := Prim_Id;
else
Own_Op := Prim_Id;
end if;
end if;
Next_Elmt (Prim_Elmt);
end loop;
if Present (Own_Op) then
return Own_Op;
elsif Present (Inher_Op) then
return Inher_Op;
else
return Empty;
end if;
end Find_Optional_Prim_Op;
------------------
-- Find_Prim_Op --
------------------
function Find_Prim_Op
(T : Entity_Id; Name : Name_Id) return Entity_Id
is
Result : constant Entity_Id := Find_Optional_Prim_Op (T, Name);
begin
if No (Result) then
raise Program_Error;
end if;
return Result;
end Find_Prim_Op;
------------------
-- Find_Prim_Op --
------------------
function Find_Prim_Op
(T : Entity_Id;
Name : TSS_Name_Type) return Entity_Id
is
Result : constant Entity_Id := Find_Optional_Prim_Op (T, Name);
begin
if No (Result) then
raise Program_Error;
end if;
return Result;
end Find_Prim_Op;
----------------------------
-- Find_Protection_Object --
----------------------------
function Find_Protection_Object (Scop : Entity_Id) return Entity_Id is
S : Entity_Id;
begin
S := Scop;
while Present (S) loop
if Ekind (S) in E_Entry | E_Entry_Family | E_Function | E_Procedure
and then Present (Protection_Object (S))
then
return Protection_Object (S);
end if;
S := Scope (S);
end loop;
-- If we do not find a Protection object in the scope chain, then
-- something has gone wrong, most likely the object was never created.
raise Program_Error;
end Find_Protection_Object;
--------------------------
-- Find_Protection_Type --
--------------------------
function Find_Protection_Type (Conc_Typ : Entity_Id) return Entity_Id is
Comp : Entity_Id;
Typ : Entity_Id := Conc_Typ;
begin
if Is_Concurrent_Type (Typ) then
Typ := Corresponding_Record_Type (Typ);
end if;
-- Since restriction violations are not considered serious errors, the
-- expander remains active, but may leave the corresponding record type
-- malformed. In such cases, component _object is not available so do
-- not look for it.
if not Analyzed (Typ) then
return Empty;
end if;
Comp := First_Component (Typ);
while Present (Comp) loop
if Chars (Comp) = Name_uObject then
return Base_Type (Etype (Comp));
end if;
Next_Component (Comp);
end loop;
-- The corresponding record of a protected type should always have an
-- _object field.
raise Program_Error;
end Find_Protection_Type;
function Find_Storage_Op
(Typ : Entity_Id;
Nam : Name_Id) return Entity_Id
is
use Sem_Util.Storage_Model_Support;
begin
if Has_Storage_Model_Type_Aspect (Typ) then
declare
SMT_Op : constant Entity_Id :=
Get_Storage_Model_Type_Entity (Typ, Nam);
begin
if not Present (SMT_Op) then
raise Program_Error;
else
return SMT_Op;
end if;
end;
-- Otherwise we assume that Typ is a descendant of Root_Storage_Pool
else
return Find_Prim_Op (Typ, Nam);
end if;
end Find_Storage_Op;
-----------------------
-- Find_Hook_Context --
-----------------------
function Find_Hook_Context (N : Node_Id) return Node_Id is
Par : Node_Id;
Top : Node_Id;
Wrapped_Node : Node_Id;
-- Note: if we are in a transient scope, we want to reuse it as
-- the context for actions insertion, if possible. But if N is itself
-- part of the stored actions for the current transient scope,
-- then we need to insert at the appropriate (inner) location in
-- the not as an action on Node_To_Be_Wrapped.
In_Cond_Expr : constant Boolean := Within_Case_Or_If_Expression (N);
begin
-- When the node is inside a case/if expression, the lifetime of any
-- temporary controlled object is extended. Find a suitable insertion
-- node by locating the topmost case or if expressions.
if In_Cond_Expr then
Par := N;
Top := N;
while Present (Par) loop
if Nkind (Original_Node (Par)) in
N_Case_Expression | N_If_Expression
then
Top := Par;
-- Prevent the search from going too far
elsif Is_Body_Or_Package_Declaration (Par) then
exit;
end if;
Par := Parent (Par);
end loop;
-- The topmost case or if expression is now recovered, but it may
-- still not be the correct place to add generated code. Climb to
-- find a parent that is part of a declarative or statement list,
-- and is not a list of actuals in a call.
Par := Top;
while Present (Par) loop
if Is_List_Member (Par)
and then Nkind (Par) not in N_Component_Association
| N_Discriminant_Association
| N_Parameter_Association
| N_Pragma_Argument_Association
| N_Aggregate
| N_Delta_Aggregate
| N_Extension_Aggregate
and then Nkind (Parent (Par)) not in N_Function_Call
| N_Procedure_Call_Statement
| N_Entry_Call_Statement
then
return Par;
-- Prevent the search from going too far
elsif Is_Body_Or_Package_Declaration (Par) then
exit;
end if;
Par := Parent (Par);
end loop;
return Par;
else
Par := N;
while Present (Par) loop
-- Keep climbing past various operators
if Nkind (Parent (Par)) in N_Op
or else Nkind (Parent (Par)) in N_And_Then | N_Or_Else
then
Par := Parent (Par);
else
exit;
end if;
end loop;
Top := Par;
-- The node may be located in a pragma in which case return the
-- pragma itself:
-- pragma Precondition (... and then Ctrl_Func_Call ...);
-- Similar case occurs when the node is related to an object
-- declaration or assignment:
-- Obj [: Some_Typ] := ... and then Ctrl_Func_Call ...;
-- Another case to consider is when the node is part of a return
-- statement:
-- return ... and then Ctrl_Func_Call ...;
-- Another case is when the node acts as a formal in a procedure
-- call statement:
-- Proc (... and then Ctrl_Func_Call ...);
if Scope_Is_Transient then
Wrapped_Node := Node_To_Be_Wrapped;
else
Wrapped_Node := Empty;
end if;
while Present (Par) loop
if Par = Wrapped_Node
or else Nkind (Par) in N_Assignment_Statement
| N_Object_Declaration
| N_Pragma
| N_Procedure_Call_Statement
| N_Simple_Return_Statement
then
return Par;
-- Prevent the search from going too far
elsif Is_Body_Or_Package_Declaration (Par) then
exit;
end if;
Par := Parent (Par);
end loop;
-- Return the topmost short circuit operator
return Top;
end if;
end Find_Hook_Context;
------------------------------
-- Following_Address_Clause --
------------------------------
function Following_Address_Clause (D : Node_Id) return Node_Id is
Id : constant Entity_Id := Defining_Identifier (D);
Result : Node_Id;
Par : Node_Id;
function Check_Decls (D : Node_Id) return Node_Id;
-- This internal function differs from the main function in that it
-- gets called to deal with a following package private part, and
-- it checks declarations starting with D (the main function checks
-- declarations following D). If D is Empty, then Empty is returned.
-----------------
-- Check_Decls --
-----------------
function Check_Decls (D : Node_Id) return Node_Id is
Decl : Node_Id;
begin
Decl := D;
while Present (Decl) loop
if Nkind (Decl) = N_At_Clause
and then Chars (Identifier (Decl)) = Chars (Id)
then
return Decl;
elsif Nkind (Decl) = N_Attribute_Definition_Clause
and then Chars (Decl) = Name_Address
and then Chars (Name (Decl)) = Chars (Id)
then
return Decl;
end if;
Next (Decl);
end loop;
-- Otherwise not found, return Empty
return Empty;
end Check_Decls;
-- Start of processing for Following_Address_Clause
begin
-- If parser detected no address clause for the identifier in question,
-- then the answer is a quick NO, without the need for a search.
if not Get_Name_Table_Boolean1 (Chars (Id)) then
return Empty;
end if;
-- Otherwise search current declarative unit
Result := Check_Decls (Next (D));
if Present (Result) then
return Result;
end if;
-- Check for possible package private part following
Par := Parent (D);
if Nkind (Par) = N_Package_Specification
and then Visible_Declarations (Par) = List_Containing (D)
and then Present (Private_Declarations (Par))
then
-- Private part present, check declarations there
return Check_Decls (First (Private_Declarations (Par)));
else
-- No private part, clause not found, return Empty
return Empty;
end if;
end Following_Address_Clause;
----------------------
-- Force_Evaluation --
----------------------
procedure Force_Evaluation
(Exp : Node_Id;
Name_Req : Boolean := False;
Related_Id : Entity_Id := Empty;
Is_Low_Bound : Boolean := False;
Is_High_Bound : Boolean := False;
Discr_Number : Int := 0;
Mode : Force_Evaluation_Mode := Relaxed)
is
begin
Remove_Side_Effects
(Exp => Exp,
Name_Req => Name_Req,
Variable_Ref => True,
Renaming_Req => False,
Related_Id => Related_Id,
Is_Low_Bound => Is_Low_Bound,
Is_High_Bound => Is_High_Bound,
Discr_Number => Discr_Number,
Check_Side_Effects =>
Is_Static_Expression (Exp)
or else Mode = Relaxed);
end Force_Evaluation;
---------------------------------
-- Fully_Qualified_Name_String --
---------------------------------
function Fully_Qualified_Name_String
(E : Entity_Id;
Append_NUL : Boolean := True) return String_Id
is
procedure Internal_Full_Qualified_Name (E : Entity_Id);
-- Compute recursively the qualified name without NUL at the end, adding
-- it to the currently started string being generated
----------------------------------
-- Internal_Full_Qualified_Name --
----------------------------------
procedure Internal_Full_Qualified_Name (E : Entity_Id) is
Ent : Entity_Id;
begin
-- Deal properly with child units
if Nkind (E) = N_Defining_Program_Unit_Name then
Ent := Defining_Identifier (E);
else
Ent := E;
end if;
-- Compute qualification recursively (only "Standard" has no scope)
if Present (Scope (Scope (Ent))) then
Internal_Full_Qualified_Name (Scope (Ent));
Store_String_Char (Get_Char_Code ('.'));
end if;
-- Every entity should have a name except some expanded blocks
-- don't bother about those.
if Chars (Ent) = No_Name then
return;
end if;
-- Generates the entity name in upper case
Get_Decoded_Name_String (Chars (Ent));
Set_All_Upper_Case;
Store_String_Chars (Name_Buffer (1 .. Name_Len));
return;
end Internal_Full_Qualified_Name;
-- Start of processing for Full_Qualified_Name
begin
Start_String;
Internal_Full_Qualified_Name (E);
if Append_NUL then
Store_String_Char (Get_Char_Code (ASCII.NUL));
end if;
return End_String;
end Fully_Qualified_Name_String;
---------------------------------
-- Get_Current_Value_Condition --
---------------------------------
-- Note: the implementation of this procedure is very closely tied to the
-- implementation of Set_Current_Value_Condition. In the Get procedure, we
-- interpret Current_Value fields set by the Set procedure, so the two
-- procedures need to be closely coordinated.
procedure Get_Current_Value_Condition
(Var : Node_Id;
Op : out Node_Kind;
Val : out Node_Id)
is
Loc : constant Source_Ptr := Sloc (Var);
Ent : constant Entity_Id := Entity (Var);
procedure Process_Current_Value_Condition (N : Node_Id; S : Boolean);
-- N is an expression which holds either True (S = True) or False (S =
-- False) in the condition. This procedure digs out the expression and
-- if it refers to Ent, sets Op and Val appropriately.
-------------------------------------
-- Process_Current_Value_Condition --
-------------------------------------
procedure Process_Current_Value_Condition
(N : Node_Id;
S : Boolean)
is
Cond : Node_Id;
Prev_Cond : Node_Id;
Sens : Boolean;
begin
Cond := N;
Sens := S;
loop
Prev_Cond := Cond;
-- Deal with NOT operators, inverting sense
while Nkind (Cond) = N_Op_Not loop
Cond := Right_Opnd (Cond);
Sens := not Sens;
end loop;
-- Deal with conversions, qualifications, and expressions with
-- actions.
while Nkind (Cond) in N_Type_Conversion
| N_Qualified_Expression
| N_Expression_With_Actions
loop
Cond := Expression (Cond);
end loop;
exit when Cond = Prev_Cond;
end loop;
-- Deal with AND THEN and AND cases
if Nkind (Cond) in N_And_Then | N_Op_And then
-- Don't ever try to invert a condition that is of the form of an
-- AND or AND THEN (since we are not doing sufficiently general
-- processing to allow this).
if Sens = False then
Op := N_Empty;
Val := Empty;
return;
end if;
-- Recursively process AND and AND THEN branches
Process_Current_Value_Condition (Left_Opnd (Cond), True);
pragma Assert (Op'Valid);
if Op /= N_Empty then
return;
end if;
Process_Current_Value_Condition (Right_Opnd (Cond), True);
return;
-- Case of relational operator
elsif Nkind (Cond) in N_Op_Compare then
Op := Nkind (Cond);
-- Invert sense of test if inverted test
if Sens = False then
case Op is
when N_Op_Eq => Op := N_Op_Ne;
when N_Op_Ne => Op := N_Op_Eq;
when N_Op_Lt => Op := N_Op_Ge;
when N_Op_Gt => Op := N_Op_Le;
when N_Op_Le => Op := N_Op_Gt;
when N_Op_Ge => Op := N_Op_Lt;
when others => raise Program_Error;
end case;
end if;
-- Case of entity op value
if Is_Entity_Name (Left_Opnd (Cond))
and then Ent = Entity (Left_Opnd (Cond))
and then Compile_Time_Known_Value (Right_Opnd (Cond))
then
Val := Right_Opnd (Cond);
-- Case of value op entity
elsif Is_Entity_Name (Right_Opnd (Cond))
and then Ent = Entity (Right_Opnd (Cond))
and then Compile_Time_Known_Value (Left_Opnd (Cond))
then
Val := Left_Opnd (Cond);
-- We are effectively swapping operands
case Op is
when N_Op_Eq => null;
when N_Op_Ne => null;
when N_Op_Lt => Op := N_Op_Gt;
when N_Op_Gt => Op := N_Op_Lt;
when N_Op_Le => Op := N_Op_Ge;
when N_Op_Ge => Op := N_Op_Le;
when others => raise Program_Error;
end case;
else
Op := N_Empty;
end if;
return;
elsif Nkind (Cond) in N_Type_Conversion
| N_Qualified_Expression
| N_Expression_With_Actions
then
Cond := Expression (Cond);
-- Case of Boolean variable reference, return as though the
-- reference had said var = True.
else
if Is_Entity_Name (Cond) and then Ent = Entity (Cond) then
Val := New_Occurrence_Of (Standard_True, Sloc (Cond));
if Sens = False then
Op := N_Op_Ne;
else
Op := N_Op_Eq;
end if;
end if;
end if;
end Process_Current_Value_Condition;
-- Start of processing for Get_Current_Value_Condition
begin
Op := N_Empty;
Val := Empty;
-- Immediate return, nothing doing, if this is not an object
if not Is_Object (Ent) then
return;
end if;
-- In GNATprove mode we don't want to use current value optimizer, in
-- particular for loop invariant expressions and other assertions that
-- act as cut points for proof. The optimizer often folds expressions
-- into True/False where they trivially follow from the previous
-- assignments, but this deprives proof from the information needed to
-- discharge checks that are beyond the scope of the value optimizer.
if GNATprove_Mode then
return;
end if;
-- Otherwise examine current value
declare
CV : constant Node_Id := Current_Value (Ent);
Sens : Boolean;
Stm : Node_Id;
begin
-- If statement. Condition is known true in THEN section, known False
-- in any ELSIF or ELSE part, and unknown outside the IF statement.
if Nkind (CV) = N_If_Statement then
-- Before start of IF statement
if Loc < Sloc (CV) then
return;
-- After end of IF statement
elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then
return;
end if;
-- At this stage we know that we are within the IF statement, but
-- unfortunately, the tree does not record the SLOC of the ELSE so
-- we cannot use a simple SLOC comparison to distinguish between
-- the then/else statements, so we have to climb the tree.
declare
N : Node_Id;
begin
N := Parent (Var);
while Parent (N) /= CV loop
N := Parent (N);
-- If we fall off the top of the tree, then that's odd, but
-- perhaps it could occur in some error situation, and the
-- safest response is simply to assume that the outcome of
-- the condition is unknown. No point in bombing during an
-- attempt to optimize things.
if No (N) then
return;
end if;
end loop;
-- Now we have N pointing to a node whose parent is the IF
-- statement in question, so now we can tell if we are within
-- the THEN statements.
if Is_List_Member (N)
and then List_Containing (N) = Then_Statements (CV)
then
Sens := True;
-- If the variable reference does not come from source, we
-- cannot reliably tell whether it appears in the else part.
-- In particular, if it appears in generated code for a node
-- that requires finalization, it may be attached to a list
-- that has not been yet inserted into the code. For now,
-- treat it as unknown.
elsif not Comes_From_Source (N) then
return;
-- Otherwise we must be in ELSIF or ELSE part
else
Sens := False;
end if;
end;
-- ELSIF part. Condition is known true within the referenced
-- ELSIF, known False in any subsequent ELSIF or ELSE part,
-- and unknown before the ELSE part or after the IF statement.
elsif Nkind (CV) = N_Elsif_Part then
-- if the Elsif_Part had condition_actions, the elsif has been
-- rewritten as a nested if, and the original elsif_part is
-- detached from the tree, so there is no way to obtain useful
-- information on the current value of the variable.
-- Can this be improved ???
if No (Parent (CV)) then
return;
end if;
Stm := Parent (CV);
-- If the tree has been otherwise rewritten there is nothing
-- else to be done either.
if Nkind (Stm) /= N_If_Statement then
return;
end if;
-- Before start of ELSIF part
if Loc < Sloc (CV) then
return;
-- After end of IF statement
elsif Loc >= Sloc (Stm) +
Text_Ptr (UI_To_Int (End_Span (Stm)))
then
return;
end if;
-- Again we lack the SLOC of the ELSE, so we need to climb the
-- tree to see if we are within the ELSIF part in question.
declare
N : Node_Id;
begin
N := Parent (Var);
while Parent (N) /= Stm loop
N := Parent (N);
-- If we fall off the top of the tree, then that's odd, but
-- perhaps it could occur in some error situation, and the
-- safest response is simply to assume that the outcome of
-- the condition is unknown. No point in bombing during an
-- attempt to optimize things.
if No (N) then
return;
end if;
end loop;
-- Now we have N pointing to a node whose parent is the IF
-- statement in question, so see if is the ELSIF part we want.
-- the THEN statements.
if N = CV then
Sens := True;
-- Otherwise we must be in subsequent ELSIF or ELSE part
else
Sens := False;
end if;
end;
-- Iteration scheme of while loop. The condition is known to be
-- true within the body of the loop.
elsif Nkind (CV) = N_Iteration_Scheme then
declare
Loop_Stmt : constant Node_Id := Parent (CV);
begin
-- Before start of body of loop
if Loc < Sloc (Loop_Stmt) then
return;
-- After end of LOOP statement
elsif Loc >= Sloc (End_Label (Loop_Stmt)) then
return;
-- We are within the body of the loop
else
Sens := True;
end if;
end;
-- All other cases of Current_Value settings
else
return;
end if;
-- If we fall through here, then we have a reportable condition, Sens
-- is True if the condition is true and False if it needs inverting.
Process_Current_Value_Condition (Condition (CV), Sens);
end;
end Get_Current_Value_Condition;
-----------------------
-- Get_Index_Subtype --
-----------------------
function Get_Index_Subtype (N : Node_Id) return Entity_Id is
P_Type : Entity_Id := Etype (Prefix (N));
Indx : Node_Id;
J : Int;
begin
if Is_Access_Type (P_Type) then
P_Type := Designated_Type (P_Type);
end if;
if No (Expressions (N)) then
J := 1;
else
J := UI_To_Int (Expr_Value (First (Expressions (N))));
end if;
Indx := First_Index (P_Type);
while J > 1 loop
Next_Index (Indx);
J := J - 1;
end loop;
return Etype (Indx);
end Get_Index_Subtype;
-----------------------
-- Get_Mapped_Entity --
-----------------------
function Get_Mapped_Entity (E : Entity_Id) return Entity_Id is
begin
return Type_Map.Get (E);
end Get_Mapped_Entity;
---------------------
-- Get_Stream_Size --
---------------------
function Get_Stream_Size (E : Entity_Id) return Uint is
begin
-- If we have a Stream_Size clause for this type use it
if Has_Stream_Size_Clause (E) then
return Static_Integer (Expression (Stream_Size_Clause (E)));
-- Otherwise the Stream_Size is the size of the type
else
return Esize (E);
end if;
end Get_Stream_Size;
---------------------------
-- Has_Access_Constraint --
---------------------------
function Has_Access_Constraint (E : Entity_Id) return Boolean is
Disc : Entity_Id;
T : constant Entity_Id := Etype (E);
begin
if Has_Per_Object_Constraint (E) and then Has_Discriminants (T) then
Disc := First_Discriminant (T);
while Present (Disc) loop
if Is_Access_Type (Etype (Disc)) then
return True;
end if;
Next_Discriminant (Disc);
end loop;
return False;
else
return False;
end if;
end Has_Access_Constraint;
--------------------
-- Homonym_Number --
--------------------
function Homonym_Number (Subp : Entity_Id) return Pos is
Hom : Entity_Id := Homonym (Subp);
Count : Pos := 1;
begin
while Present (Hom) loop
if Scope (Hom) = Scope (Subp) then
Count := Count + 1;
end if;
Hom := Homonym (Hom);
end loop;
return Count;
end Homonym_Number;
-----------------------------------
-- In_Library_Level_Package_Body --
-----------------------------------
function In_Library_Level_Package_Body (Id : Entity_Id) return Boolean is
begin
-- First determine whether the entity appears at the library level, then
-- look at the containing unit.
if Is_Library_Level_Entity (Id) then
declare
Container : constant Node_Id := Cunit (Get_Source_Unit (Id));
begin
return Nkind (Unit (Container)) = N_Package_Body;
end;
end if;
return False;
end In_Library_Level_Package_Body;
------------------------------
-- In_Unconditional_Context --
------------------------------
function In_Unconditional_Context (Node : Node_Id) return Boolean is
P : Node_Id;
begin
P := Node;
while Present (P) loop
case Nkind (P) is
when N_Subprogram_Body => return True;
when N_If_Statement => return False;
when N_Loop_Statement => return False;
when N_Case_Statement => return False;
when others => P := Parent (P);
end case;
end loop;
return False;
end In_Unconditional_Context;
-------------------
-- Insert_Action --
-------------------
procedure Insert_Action
(Assoc_Node : Node_Id;
Ins_Action : Node_Id;
Spec_Expr_OK : Boolean := False)
is
begin
if Present (Ins_Action) then
Insert_Actions
(Assoc_Node => Assoc_Node,
Ins_Actions => New_List (Ins_Action),
Spec_Expr_OK => Spec_Expr_OK);
end if;
end Insert_Action;
-- Version with check(s) suppressed
procedure Insert_Action
(Assoc_Node : Node_Id;
Ins_Action : Node_Id;
Suppress : Check_Id;
Spec_Expr_OK : Boolean := False)
is
begin
Insert_Actions
(Assoc_Node => Assoc_Node,
Ins_Actions => New_List (Ins_Action),
Suppress => Suppress,
Spec_Expr_OK => Spec_Expr_OK);
end Insert_Action;
-------------------------
-- Insert_Action_After --
-------------------------
procedure Insert_Action_After
(Assoc_Node : Node_Id;
Ins_Action : Node_Id)
is
begin
Insert_Actions_After (Assoc_Node, New_List (Ins_Action));
end Insert_Action_After;
--------------------
-- Insert_Actions --
--------------------
procedure Insert_Actions
(Assoc_Node : Node_Id;
Ins_Actions : List_Id;
Spec_Expr_OK : Boolean := False)
is
N : Node_Id;
P : Node_Id;
Wrapped_Node : Node_Id := Empty;
begin
if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then
return;
end if;
-- Insert the action when the context is "Handling of Default and Per-
-- Object Expressions" only when requested by the caller.
if Spec_Expr_OK then
null;
-- Ignore insert of actions from inside default expression (or other
-- similar "spec expression") in the special spec-expression analyze
-- mode. Any insertions at this point have no relevance, since we are
-- only doing the analyze to freeze the types of any static expressions.
-- See section "Handling of Default and Per-Object Expressions" in the
-- spec of package Sem for further details.
elsif In_Spec_Expression then
return;
end if;
-- If the action derives from stuff inside a record, then the actions
-- are attached to the current scope, to be inserted and analyzed on
-- exit from the scope. The reason for this is that we may also be
-- generating freeze actions at the same time, and they must eventually
-- be elaborated in the correct order.
if Is_Record_Type (Current_Scope)
and then not Is_Frozen (Current_Scope)
then
if No (Scope_Stack.Table
(Scope_Stack.Last).Pending_Freeze_Actions)
then
Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions :=
Ins_Actions;
else
Append_List
(Ins_Actions,
Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions);
end if;
return;
end if;
-- We now intend to climb up the tree to find the right point to
-- insert the actions. We start at Assoc_Node, unless this node is a
-- subexpression in which case we start with its parent. We do this for
-- two reasons. First it speeds things up. Second, if Assoc_Node is
-- itself one of the special nodes like N_And_Then, then we assume that
-- an initial request to insert actions for such a node does not expect
-- the actions to get deposited in the node for later handling when the
-- node is expanded, since clearly the node is being dealt with by the
-- caller. Note that in the subexpression case, N is always the child we
-- came from.
-- N_Raise_xxx_Error is an annoying special case, it is a statement
-- if it has type Standard_Void_Type, and a subexpression otherwise.
-- Procedure calls, and similarly procedure attribute references, are
-- also statements.
if Nkind (Assoc_Node) in N_Subexpr
and then (Nkind (Assoc_Node) not in N_Raise_xxx_Error
or else Etype (Assoc_Node) /= Standard_Void_Type)
and then Nkind (Assoc_Node) /= N_Procedure_Call_Statement
and then (Nkind (Assoc_Node) /= N_Attribute_Reference
or else not Is_Procedure_Attribute_Name
(Attribute_Name (Assoc_Node)))
then
N := Assoc_Node;
P := Parent (Assoc_Node);
-- Nonsubexpression case. Note that N is initially Empty in this case
-- (N is only guaranteed non-Empty in the subexpr case).
else
N := Empty;
P := Assoc_Node;
end if;
-- Capture root of the transient scope
if Scope_Is_Transient then
Wrapped_Node := Node_To_Be_Wrapped;
end if;
loop
pragma Assert (Present (P));
-- Make sure that inserted actions stay in the transient scope
if Present (Wrapped_Node) and then N = Wrapped_Node then
Store_Before_Actions_In_Scope (Ins_Actions);
return;
end if;
case Nkind (P) is
-- Case of right operand of AND THEN or OR ELSE. Put the actions
-- in the Actions field of the right operand. They will be moved
-- out further when the AND THEN or OR ELSE operator is expanded.
-- Nothing special needs to be done for the left operand since
-- in that case the actions are executed unconditionally.
when N_Short_Circuit =>
if N = Right_Opnd (P) then
-- We are now going to either append the actions to the
-- actions field of the short-circuit operation. We will
-- also analyze the actions now.
-- This analysis is really too early, the proper thing would
-- be to just park them there now, and only analyze them if
-- we find we really need them, and to it at the proper
-- final insertion point. However attempting to this proved
-- tricky, so for now we just kill current values before and
-- after the analyze call to make sure we avoid peculiar
-- optimizations from this out of order insertion.
Kill_Current_Values;
-- If P has already been expanded, we can't park new actions
-- on it, so we need to expand them immediately, introducing
-- an Expression_With_Actions. N can't be an expression
-- with actions, or else then the actions would have been
-- inserted at an inner level.
if Analyzed (P) then
pragma Assert (Nkind (N) /= N_Expression_With_Actions);
Rewrite (N,
Make_Expression_With_Actions (Sloc (N),
Actions => Ins_Actions,
Expression => Relocate_Node (N)));
Analyze_And_Resolve (N);
elsif Present (Actions (P)) then
Insert_List_After_And_Analyze
(Last (Actions (P)), Ins_Actions);
else
Set_Actions (P, Ins_Actions);
Analyze_List (Actions (P));
end if;
Kill_Current_Values;
return;
end if;
-- Then or Else dependent expression of an if expression. Add
-- actions to Then_Actions or Else_Actions field as appropriate.
-- The actions will be moved further out when the if is expanded.
when N_If_Expression =>
declare
ThenX : constant Node_Id := Next (First (Expressions (P)));
ElseX : constant Node_Id := Next (ThenX);
begin
-- If the enclosing expression is already analyzed, as
-- is the case for nested elaboration checks, insert the
-- conditional further out.
if Analyzed (P) then
null;
-- Actions belong to the then expression, temporarily place
-- them as Then_Actions of the if expression. They will be
-- moved to the proper place later when the if expression is
-- expanded.
elsif N = ThenX then
if Present (Then_Actions (P)) then
Insert_List_After_And_Analyze
(Last (Then_Actions (P)), Ins_Actions);
else
Set_Then_Actions (P, Ins_Actions);
Analyze_List (Then_Actions (P));
end if;
return;
-- Else_Actions is treated the same as Then_Actions above
elsif N = ElseX then
if Present (Else_Actions (P)) then
Insert_List_After_And_Analyze
(Last (Else_Actions (P)), Ins_Actions);
else
Set_Else_Actions (P, Ins_Actions);
Analyze_List (Else_Actions (P));
end if;
return;
-- Actions belong to the condition. In this case they are
-- unconditionally executed, and so we can continue the
-- search for the proper insert point.
else
null;
end if;
end;
-- Alternative of case expression, we place the action in the
-- Actions field of the case expression alternative, this will
-- be handled when the case expression is expanded.
when N_Case_Expression_Alternative =>
if Present (Actions (P)) then
Insert_List_After_And_Analyze
(Last (Actions (P)), Ins_Actions);
else
Set_Actions (P, Ins_Actions);
Analyze_List (Actions (P));
end if;
return;
-- Case of appearing within an Expressions_With_Actions node. When
-- the new actions come from the expression of the expression with
-- actions, they must be added to the existing actions. The other
-- alternative is when the new actions are related to one of the
-- existing actions of the expression with actions, and should
-- never reach here: if actions are inserted on a statement
-- within the Actions of an expression with actions, or on some
-- subexpression of such a statement, then the outermost proper
-- insertion point is right before the statement, and we should
-- never climb up as far as the N_Expression_With_Actions itself.
when N_Expression_With_Actions =>
if N = Expression (P) then
if Is_Empty_List (Actions (P)) then
Append_List_To (Actions (P), Ins_Actions);
Analyze_List (Actions (P));
else
Insert_List_After_And_Analyze
(Last (Actions (P)), Ins_Actions);
end if;
return;
else
raise Program_Error;
end if;
-- Case of appearing in the condition of a while expression or
-- elsif. We insert the actions into the Condition_Actions field.
-- They will be moved further out when the while loop or elsif
-- is analyzed.
when N_Elsif_Part
| N_Iteration_Scheme
=>
if N = Condition (P) then
if Present (Condition_Actions (P)) then
Insert_List_After_And_Analyze
(Last (Condition_Actions (P)), Ins_Actions);
else
Set_Condition_Actions (P, Ins_Actions);
-- Set the parent of the insert actions explicitly. This
-- is not a syntactic field, but we need the parent field
-- set, in particular so that freeze can understand that
-- it is dealing with condition actions, and properly
-- insert the freezing actions.
Set_Parent (Ins_Actions, P);
Analyze_List (Condition_Actions (P));
end if;
return;
end if;
-- Statements, declarations, pragmas, representation clauses
when
-- Statements
N_Procedure_Call_Statement
| N_Statement_Other_Than_Procedure_Call
-- Pragmas
| N_Pragma
-- Representation_Clause
| N_At_Clause
| N_Attribute_Definition_Clause
| N_Enumeration_Representation_Clause
| N_Record_Representation_Clause
-- Declarations
| N_Abstract_Subprogram_Declaration
| N_Entry_Body
| N_Exception_Declaration
| N_Exception_Renaming_Declaration
| N_Expression_Function
| N_Formal_Abstract_Subprogram_Declaration
| N_Formal_Concrete_Subprogram_Declaration
| N_Formal_Object_Declaration
| N_Formal_Type_Declaration
| N_Full_Type_Declaration
| N_Function_Instantiation
| N_Generic_Function_Renaming_Declaration
| N_Generic_Package_Declaration
| N_Generic_Package_Renaming_Declaration
| N_Generic_Procedure_Renaming_Declaration
| N_Generic_Subprogram_Declaration
| N_Implicit_Label_Declaration
| N_Incomplete_Type_Declaration
| N_Number_Declaration
| N_Object_Declaration
| N_Object_Renaming_Declaration
| N_Package_Body
| N_Package_Body_Stub
| N_Package_Declaration
| N_Package_Instantiation
| N_Package_Renaming_Declaration
| N_Private_Extension_Declaration
| N_Private_Type_Declaration
| N_Procedure_Instantiation
| N_Protected_Body
| N_Protected_Body_Stub
| N_Single_Task_Declaration
| N_Subprogram_Body
| N_Subprogram_Body_Stub
| N_Subprogram_Declaration
| N_Subprogram_Renaming_Declaration
| N_Subtype_Declaration
| N_Task_Body
| N_Task_Body_Stub
-- Use clauses can appear in lists of declarations
| N_Use_Package_Clause
| N_Use_Type_Clause
-- Freeze entity behaves like a declaration or statement
| N_Freeze_Entity
| N_Freeze_Generic_Entity
=>
-- Do not insert here if the item is not a list member (this
-- happens for example with a triggering statement, and the
-- proper approach is to insert before the entire select).
if not Is_List_Member (P) then
null;
-- Do not insert if parent of P is an N_Component_Association
-- node (i.e. we are in the context of an N_Aggregate or
-- N_Extension_Aggregate node. In this case we want to insert
-- before the entire aggregate.
elsif Nkind (Parent (P)) = N_Component_Association then
null;
-- Do not insert if the parent of P is either an N_Variant node
-- or an N_Record_Definition node, meaning in either case that
-- P is a member of a component list, and that therefore the
-- actions should be inserted outside the complete record
-- declaration.
elsif Nkind (Parent (P)) in N_Variant | N_Record_Definition then
null;
-- Do not insert freeze nodes within the loop generated for
-- an aggregate, because they may be elaborated too late for
-- subsequent use in the back end: within a package spec the
-- loop is part of the elaboration procedure and is only
-- elaborated during the second pass.
-- If the loop comes from source, or the entity is local to the
-- loop itself it must remain within.
elsif Nkind (Parent (P)) = N_Loop_Statement
and then not Comes_From_Source (Parent (P))
and then Nkind (First (Ins_Actions)) = N_Freeze_Entity
and then
Scope (Entity (First (Ins_Actions))) /= Current_Scope
then
null;
-- Otherwise we can go ahead and do the insertion
elsif P = Wrapped_Node then
Store_Before_Actions_In_Scope (Ins_Actions);
return;
else
Insert_List_Before_And_Analyze (P, Ins_Actions);
return;
end if;
-- the expansion of Task and protected type declarations can
-- create declarations for temporaries which, like other actions
-- are inserted and analyzed before the current declaraation.
-- However, the current scope is the synchronized type, and
-- for unnesting it is critical that the proper scope for these
-- generated entities be the enclosing one.
when N_Task_Type_Declaration
| N_Protected_Type_Declaration =>
Push_Scope (Scope (Current_Scope));
Insert_List_Before_And_Analyze (P, Ins_Actions);
Pop_Scope;
return;
-- A special case, N_Raise_xxx_Error can act either as a statement
-- or a subexpression. We tell the difference by looking at the
-- Etype. It is set to Standard_Void_Type in the statement case.
when N_Raise_xxx_Error =>
if Etype (P) = Standard_Void_Type then
if P = Wrapped_Node then
Store_Before_Actions_In_Scope (Ins_Actions);
else
Insert_List_Before_And_Analyze (P, Ins_Actions);
end if;
return;
-- In the subexpression case, keep climbing
else
null;
end if;
-- If a component association appears within a loop created for
-- an array aggregate, attach the actions to the association so
-- they can be subsequently inserted within the loop. For other
-- component associations insert outside of the aggregate. For
-- an association that will generate a loop, its Loop_Actions
-- attribute is already initialized (see exp_aggr.adb).
-- The list of Loop_Actions can in turn generate additional ones,
-- that are inserted before the associated node. If the associated
-- node is outside the aggregate, the new actions are collected
-- at the end of the Loop_Actions, to respect the order in which
-- they are to be elaborated.
when N_Component_Association
| N_Iterated_Component_Association
| N_Iterated_Element_Association
=>
if Nkind (Parent (P)) = N_Aggregate
and then Present (Loop_Actions (P))
then
if Is_Empty_List (Loop_Actions (P)) then
Set_Loop_Actions (P, Ins_Actions);
Analyze_List (Ins_Actions);
else
declare
Decl : Node_Id;
begin
-- Check whether these actions were generated by a
-- declaration that is part of the Loop_Actions for
-- the component_association.
Decl := Assoc_Node;
while Present (Decl) loop
exit when Parent (Decl) = P
and then Is_List_Member (Decl)
and then
List_Containing (Decl) = Loop_Actions (P);
Decl := Parent (Decl);
end loop;
if Present (Decl) then
Insert_List_Before_And_Analyze
(Decl, Ins_Actions);
else
Insert_List_After_And_Analyze
(Last (Loop_Actions (P)), Ins_Actions);
end if;
end;
end if;
return;
else
null;
end if;
-- Special case: an attribute denoting a procedure call
when N_Attribute_Reference =>
if Is_Procedure_Attribute_Name (Attribute_Name (P)) then
if P = Wrapped_Node then
Store_Before_Actions_In_Scope (Ins_Actions);
else
Insert_List_Before_And_Analyze (P, Ins_Actions);
end if;
return;
-- In the subexpression case, keep climbing
else
null;
end if;
-- Special case: a marker
when N_Call_Marker
| N_Variable_Reference_Marker
=>
if Is_List_Member (P) then
Insert_List_Before_And_Analyze (P, Ins_Actions);
return;
end if;
-- A contract node should not belong to the tree
when N_Contract =>
raise Program_Error;
-- For all other node types, keep climbing tree
when N_Abortable_Part
| N_Accept_Alternative
| N_Access_Definition
| N_Access_Function_Definition
| N_Access_Procedure_Definition
| N_Access_To_Object_Definition
| N_Aggregate
| N_Allocator
| N_Aspect_Specification
| N_Case_Expression
| N_Case_Statement_Alternative
| N_Character_Literal
| N_Compilation_Unit
| N_Compilation_Unit_Aux
| N_Component_Clause
| N_Component_Declaration
| N_Component_Definition
| N_Component_List
| N_Constrained_Array_Definition
| N_Decimal_Fixed_Point_Definition
| N_Defining_Character_Literal
| N_Defining_Identifier
| N_Defining_Operator_Symbol
| N_Defining_Program_Unit_Name
| N_Delay_Alternative
| N_Delta_Aggregate
| N_Delta_Constraint
| N_Derived_Type_Definition
| N_Designator
| N_Digits_Constraint
| N_Discriminant_Association
| N_Discriminant_Specification
| N_Empty
| N_Entry_Body_Formal_Part
| N_Entry_Call_Alternative
| N_Entry_Declaration
| N_Entry_Index_Specification
| N_Enumeration_Type_Definition
| N_Error
| N_Exception_Handler
| N_Expanded_Name
| N_Explicit_Dereference
| N_Extension_Aggregate
| N_Floating_Point_Definition
| N_Formal_Decimal_Fixed_Point_Definition
| N_Formal_Derived_Type_Definition
| N_Formal_Discrete_Type_Definition
| N_Formal_Floating_Point_Definition
| N_Formal_Modular_Type_Definition
| N_Formal_Ordinary_Fixed_Point_Definition
| N_Formal_Package_Declaration
| N_Formal_Private_Type_Definition
| N_Formal_Incomplete_Type_Definition
| N_Formal_Signed_Integer_Type_Definition
| N_Function_Call
| N_Function_Specification
| N_Generic_Association
| N_Handled_Sequence_Of_Statements
| N_Identifier
| N_In
| N_Index_Or_Discriminant_Constraint
| N_Indexed_Component
| N_Integer_Literal
| N_Iterator_Specification
| N_Itype_Reference
| N_Label
| N_Loop_Parameter_Specification
| N_Mod_Clause
| N_Modular_Type_Definition
| N_Not_In
| N_Null
| N_Op_Abs
| N_Op_Add
| N_Op_And
| N_Op_Concat
| N_Op_Divide
| N_Op_Eq
| N_Op_Expon
| N_Op_Ge
| N_Op_Gt
| N_Op_Le
| N_Op_Lt
| N_Op_Minus
| N_Op_Mod
| N_Op_Multiply
| N_Op_Ne
| N_Op_Not
| N_Op_Or
| N_Op_Plus
| N_Op_Rem
| N_Op_Rotate_Left
| N_Op_Rotate_Right
| N_Op_Shift_Left
| N_Op_Shift_Right
| N_Op_Shift_Right_Arithmetic
| N_Op_Subtract
| N_Op_Xor
| N_Operator_Symbol
| N_Ordinary_Fixed_Point_Definition
| N_Others_Choice
| N_Package_Specification
| N_Parameter_Association
| N_Parameter_Specification
| N_Pop_Constraint_Error_Label
| N_Pop_Program_Error_Label
| N_Pop_Storage_Error_Label
| N_Pragma_Argument_Association
| N_Procedure_Specification
| N_Protected_Definition
| N_Push_Constraint_Error_Label
| N_Push_Program_Error_Label
| N_Push_Storage_Error_Label
| N_Qualified_Expression
| N_Quantified_Expression
| N_Raise_Expression
| N_Range
| N_Range_Constraint
| N_Real_Literal
| N_Real_Range_Specification
| N_Record_Definition
| N_Reference
| N_SCIL_Dispatch_Table_Tag_Init
| N_SCIL_Dispatching_Call
| N_SCIL_Membership_Test
| N_Selected_Component
| N_Signed_Integer_Type_Definition
| N_Single_Protected_Declaration
| N_Slice
| N_String_Literal
| N_Subtype_Indication
| N_Subunit
| N_Target_Name
| N_Task_Definition
| N_Terminate_Alternative
| N_Triggering_Alternative
| N_Type_Conversion
| N_Unchecked_Expression
| N_Unchecked_Type_Conversion
| N_Unconstrained_Array_Definition
| N_Unused_At_End
| N_Unused_At_Start
| N_Variant
| N_Variant_Part
| N_Validate_Unchecked_Conversion
| N_With_Clause
=>
null;
end case;
-- If we fall through above tests, keep climbing tree
N := P;
if Nkind (Parent (N)) = N_Subunit then
-- This is the proper body corresponding to a stub. Insertion must
-- be done at the point of the stub, which is in the declarative
-- part of the parent unit.
P := Corresponding_Stub (Parent (N));
else
P := Parent (N);
end if;
end loop;
end Insert_Actions;
-- Version with check(s) suppressed
procedure Insert_Actions
(Assoc_Node : Node_Id;
Ins_Actions : List_Id;
Suppress : Check_Id;
Spec_Expr_OK : Boolean := False)
is
begin
if Suppress = All_Checks then
declare
Sva : constant Suppress_Array := Scope_Suppress.Suppress;
begin
Scope_Suppress.Suppress := (others => True);
Insert_Actions (Assoc_Node, Ins_Actions, Spec_Expr_OK);
Scope_Suppress.Suppress := Sva;
end;
else
declare
Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
begin
Scope_Suppress.Suppress (Suppress) := True;
Insert_Actions (Assoc_Node, Ins_Actions, Spec_Expr_OK);
Scope_Suppress.Suppress (Suppress) := Svg;
end;
end if;
end Insert_Actions;
--------------------------
-- Insert_Actions_After --
--------------------------
procedure Insert_Actions_After
(Assoc_Node : Node_Id;
Ins_Actions : List_Id)
is
begin
if Scope_Is_Transient and then Assoc_Node = Node_To_Be_Wrapped then
Store_After_Actions_In_Scope (Ins_Actions);
else
Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions);
end if;
end Insert_Actions_After;
------------------------
-- Insert_Declaration --
------------------------
procedure Insert_Declaration (N : Node_Id; Decl : Node_Id) is
P : Node_Id;
begin
pragma Assert (Nkind (N) in N_Subexpr);
-- Climb until we find a procedure or a package
P := N;
loop
pragma Assert (Present (Parent (P)));
P := Parent (P);
if Is_List_Member (P) then
exit when Nkind (Parent (P)) in
N_Package_Specification | N_Subprogram_Body;
-- Special handling for handled sequence of statements, we must
-- insert in the statements not the exception handlers!
if Nkind (Parent (P)) = N_Handled_Sequence_Of_Statements then
P := First (Statements (Parent (P)));
exit;
end if;
end if;
end loop;
-- Now do the insertion
Insert_Before (P, Decl);
Analyze (Decl);
end Insert_Declaration;
---------------------------------
-- Insert_Library_Level_Action --
---------------------------------
procedure Insert_Library_Level_Action (N : Node_Id) is
Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
begin
Push_Scope (Cunit_Entity (Current_Sem_Unit));
-- And not Main_Unit as previously. If the main unit is a body,
-- the scope needed to analyze the actions is the entity of the
-- corresponding declaration.
if No (Actions (Aux)) then
Set_Actions (Aux, New_List (N));
else
Append (N, Actions (Aux));
end if;
Analyze (N);
Pop_Scope;
end Insert_Library_Level_Action;
----------------------------------
-- Insert_Library_Level_Actions --
----------------------------------
procedure Insert_Library_Level_Actions (L : List_Id) is
Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
begin
if Is_Non_Empty_List (L) then
Push_Scope (Cunit_Entity (Main_Unit));
-- ??? should this be Current_Sem_Unit instead of Main_Unit?
if No (Actions (Aux)) then
Set_Actions (Aux, L);
Analyze_List (L);
else
Insert_List_After_And_Analyze (Last (Actions (Aux)), L);
end if;
Pop_Scope;
end if;
end Insert_Library_Level_Actions;
----------------------
-- Inside_Init_Proc --
----------------------
function Inside_Init_Proc return Boolean is
Proc : constant Entity_Id := Enclosing_Init_Proc;
begin
return Proc /= Empty;
end Inside_Init_Proc;
----------------------
-- Integer_Type_For --
----------------------
function Integer_Type_For (S : Uint; Uns : Boolean) return Entity_Id is
begin
pragma Assert (S <= System_Max_Integer_Size);
-- This is the canonical 32-bit type
if S <= Standard_Integer_Size then
if Uns then
return Standard_Unsigned;
else
return Standard_Integer;
end if;
-- This is the canonical 64-bit type
elsif S <= Standard_Long_Long_Integer_Size then
if Uns then
return Standard_Long_Long_Unsigned;
else
return Standard_Long_Long_Integer;
end if;
-- This is the canonical 128-bit type
elsif S <= Standard_Long_Long_Long_Integer_Size then
if Uns then
return Standard_Long_Long_Long_Unsigned;
else
return Standard_Long_Long_Long_Integer;
end if;
else
raise Program_Error;
end if;
end Integer_Type_For;
--------------------------------------------------
-- Is_Displacement_Of_Object_Or_Function_Result --
--------------------------------------------------
function Is_Displacement_Of_Object_Or_Function_Result
(Obj_Id : Entity_Id) return Boolean
is
function Is_Controlled_Function_Call (N : Node_Id) return Boolean;
-- Determine whether node N denotes a controlled function call
function Is_Controlled_Indexing (N : Node_Id) return Boolean;
-- Determine whether node N denotes a generalized indexing form which
-- involves a controlled result.
function Is_Displace_Call (N : Node_Id) return Boolean;
-- Determine whether node N denotes a call to Ada.Tags.Displace
function Is_Source_Object (N : Node_Id) return Boolean;
-- Determine whether a particular node denotes a source object
function Strip (N : Node_Id) return Node_Id;
-- Examine arbitrary node N by stripping various indirections and return
-- the "real" node.
---------------------------------
-- Is_Controlled_Function_Call --
---------------------------------
function Is_Controlled_Function_Call (N : Node_Id) return Boolean is
Expr : Node_Id;
begin
-- When a function call appears in Object.Operation format, the
-- original representation has several possible forms depending on
-- the availability and form of actual parameters:
-- Obj.Func N_Selected_Component
-- Obj.Func (Actual) N_Indexed_Component
-- Obj.Func (Formal => Actual) N_Function_Call, whose Name is an
-- N_Selected_Component
Expr := Original_Node (N);
loop
if Nkind (Expr) = N_Function_Call then
Expr := Name (Expr);
-- "Obj.Func (Actual)" case
elsif Nkind (Expr) = N_Indexed_Component then
Expr := Prefix (Expr);
-- "Obj.Func" or "Obj.Func (Formal => Actual) case
elsif Nkind (Expr) = N_Selected_Component then
Expr := Selector_Name (Expr);
else
exit;
end if;
end loop;
return
Nkind (Expr) in N_Has_Entity
and then Present (Entity (Expr))
and then Ekind (Entity (Expr)) = E_Function
and then Needs_Finalization (Etype (Entity (Expr)));
end Is_Controlled_Function_Call;
----------------------------
-- Is_Controlled_Indexing --
----------------------------
function Is_Controlled_Indexing (N : Node_Id) return Boolean is
Expr : constant Node_Id := Original_Node (N);
begin
return
Nkind (Expr) = N_Indexed_Component
and then Present (Generalized_Indexing (Expr))
and then Needs_Finalization (Etype (Expr));
end Is_Controlled_Indexing;
----------------------
-- Is_Displace_Call --
----------------------
function Is_Displace_Call (N : Node_Id) return Boolean is
Call : constant Node_Id := Strip (N);
begin
return
Present (Call)
and then Nkind (Call) = N_Function_Call
and then Nkind (Name (Call)) in N_Has_Entity
and then Is_RTE (Entity (Name (Call)), RE_Displace);
end Is_Displace_Call;
----------------------
-- Is_Source_Object --
----------------------
function Is_Source_Object (N : Node_Id) return Boolean is
Obj : constant Node_Id := Strip (N);
begin
return
Present (Obj)
and then Comes_From_Source (Obj)
and then Nkind (Obj) in N_Has_Entity
and then Is_Object (Entity (Obj));
end Is_Source_Object;
-----------
-- Strip --
-----------
function Strip (N : Node_Id) return Node_Id is
Result : Node_Id;
begin
Result := N;
loop
if Nkind (Result) = N_Explicit_Dereference then
Result := Prefix (Result);
elsif Nkind (Result) in
N_Type_Conversion | N_Unchecked_Type_Conversion
then
Result := Expression (Result);
else
exit;
end if;
end loop;
return Result;
end Strip;
-- Local variables
Obj_Decl : constant Node_Id := Declaration_Node (Obj_Id);
Obj_Typ : constant Entity_Id := Base_Type (Etype (Obj_Id));
Orig_Decl : constant Node_Id := Original_Node (Obj_Decl);
Orig_Expr : Node_Id;
-- Start of processing for Is_Displacement_Of_Object_Or_Function_Result
begin
-- Case 1:
-- Obj : CW_Type := Function_Call (...);
-- is rewritten into:
-- Temp : ... := Function_Call (...)'reference;
-- Obj : CW_Type renames (... Ada.Tags.Displace (Temp));
-- where the return type of the function and the class-wide type require
-- dispatch table pointer displacement.
-- Case 2:
-- Obj : CW_Type := Container (...);
-- is rewritten into:
-- Temp : ... := Function_Call (Container, ...)'reference;
-- Obj : CW_Type renames (... Ada.Tags.Displace (Temp));
-- where the container element type and the class-wide type require
-- dispatch table pointer dispacement.
-- Case 3:
-- Obj : CW_Type := Src_Obj;
-- is rewritten into:
-- Obj : CW_Type renames (... Ada.Tags.Displace (Src_Obj));
-- where the type of the source object and the class-wide type require
-- dispatch table pointer displacement.
if Nkind (Obj_Decl) = N_Object_Renaming_Declaration
and then Is_Class_Wide_Type (Obj_Typ)
and then Is_Displace_Call (Renamed_Object (Obj_Id))
and then Nkind (Orig_Decl) = N_Object_Declaration
and then Comes_From_Source (Orig_Decl)
then
Orig_Expr := Expression (Orig_Decl);
return
Is_Controlled_Function_Call (Orig_Expr)
or else Is_Controlled_Indexing (Orig_Expr)
or else Is_Source_Object (Orig_Expr);
end if;
return False;
end Is_Displacement_Of_Object_Or_Function_Result;
------------------------------
-- Is_Finalizable_Transient --
------------------------------
function Is_Finalizable_Transient
(Decl : Node_Id;
Rel_Node : Node_Id) return Boolean
is
Obj_Id : constant Entity_Id := Defining_Identifier (Decl);
Obj_Typ : constant Entity_Id := Base_Type (Etype (Obj_Id));
function Initialized_By_Access (Trans_Id : Entity_Id) return Boolean;
-- Determine whether transient object Trans_Id is initialized either
-- by a function call which returns an access type or simply renames
-- another pointer.
function Initialized_By_Aliased_BIP_Func_Call
(Trans_Id : Entity_Id) return Boolean;
-- Determine whether transient object Trans_Id is initialized by a
-- build-in-place function call where the BIPalloc parameter is of
-- value 1 and BIPaccess is not null. This case creates an aliasing
-- between the returned value and the value denoted by BIPaccess.
function Is_Aliased
(Trans_Id : Entity_Id;
First_Stmt : Node_Id) return Boolean;
-- Determine whether transient object Trans_Id has been renamed or
-- aliased through 'reference in the statement list starting from
-- First_Stmt.
function Is_Allocated (Trans_Id : Entity_Id) return Boolean;
-- Determine whether transient object Trans_Id is allocated on the heap
function Is_Iterated_Container
(Trans_Id : Entity_Id;
First_Stmt : Node_Id) return Boolean;
-- Determine whether transient object Trans_Id denotes a container which
-- is in the process of being iterated in the statement list starting
-- from First_Stmt.
function Is_Part_Of_BIP_Return_Statement (N : Node_Id) return Boolean;
-- Return True if N is directly part of a build-in-place return
-- statement.
---------------------------
-- Initialized_By_Access --
---------------------------
function Initialized_By_Access (Trans_Id : Entity_Id) return Boolean is
Expr : constant Node_Id := Expression (Parent (Trans_Id));
begin
return
Present (Expr)
and then Nkind (Expr) /= N_Reference
and then Is_Access_Type (Etype (Expr));
end Initialized_By_Access;
------------------------------------------
-- Initialized_By_Aliased_BIP_Func_Call --
------------------------------------------
function Initialized_By_Aliased_BIP_Func_Call
(Trans_Id : Entity_Id) return Boolean
is
Call : Node_Id := Expression (Parent (Trans_Id));
begin
-- Build-in-place calls usually appear in 'reference format
if Nkind (Call) = N_Reference then
Call := Prefix (Call);
end if;
Call := Unqual_Conv (Call);
if Is_Build_In_Place_Function_Call (Call) then
declare
Access_Nam : Name_Id := No_Name;
Access_OK : Boolean := False;
Actual : Node_Id;
Alloc_Nam : Name_Id := No_Name;
Alloc_OK : Boolean := False;
Formal : Node_Id;
Func_Id : Entity_Id;
Param : Node_Id;
begin
-- Examine all parameter associations of the function call
Param := First (Parameter_Associations (Call));
while Present (Param) loop
if Nkind (Param) = N_Parameter_Association
and then Nkind (Selector_Name (Param)) = N_Identifier
then
Actual := Explicit_Actual_Parameter (Param);
Formal := Selector_Name (Param);
-- Construct the names of formals BIPaccess and BIPalloc
-- using the function name retrieved from an arbitrary
-- formal.
if Access_Nam = No_Name
and then Alloc_Nam = No_Name
and then Present (Entity (Formal))
then
Func_Id := Scope (Entity (Formal));
Access_Nam :=
New_External_Name (Chars (Func_Id),
BIP_Formal_Suffix (BIP_Object_Access));
Alloc_Nam :=
New_External_Name (Chars (Func_Id),
BIP_Formal_Suffix (BIP_Alloc_Form));
end if;
-- A match for BIPaccess => Temp has been found
if Chars (Formal) = Access_Nam
and then Nkind (Actual) /= N_Null
then
Access_OK := True;
end if;
-- A match for BIPalloc => 1 has been found
if Chars (Formal) = Alloc_Nam
and then Nkind (Actual) = N_Integer_Literal
and then Intval (Actual) = Uint_1
then
Alloc_OK := True;
end if;
end if;
Next (Param);
end loop;
return Access_OK and Alloc_OK;
end;
end if;
return False;
end Initialized_By_Aliased_BIP_Func_Call;
----------------
-- Is_Aliased --
----------------
function Is_Aliased
(Trans_Id : Entity_Id;
First_Stmt : Node_Id) return Boolean
is
function Find_Renamed_Object (Ren_Decl : Node_Id) return Entity_Id;
-- Given an object renaming declaration, retrieve the entity of the
-- renamed name. Return Empty if the renamed name is anything other
-- than a variable or a constant.
-------------------------
-- Find_Renamed_Object --
-------------------------
function Find_Renamed_Object (Ren_Decl : Node_Id) return Entity_Id is
Ren_Obj : Node_Id := Empty;
function Find_Object (N : Node_Id) return Traverse_Result;
-- Try to detect an object which is either a constant or a
-- variable.
-----------------
-- Find_Object --
-----------------
function Find_Object (N : Node_Id) return Traverse_Result is
begin
-- Stop the search once a constant or a variable has been
-- detected.
if Nkind (N) = N_Identifier
and then Present (Entity (N))
and then Ekind (Entity (N)) in E_Constant | E_Variable
then
Ren_Obj := Entity (N);
return Abandon;
end if;
return OK;
end Find_Object;
procedure Search is new Traverse_Proc (Find_Object);
-- Local variables
Typ : constant Entity_Id := Etype (Defining_Identifier (Ren_Decl));
-- Start of processing for Find_Renamed_Object
begin
-- Actions related to dispatching calls may appear as renamings of
-- tags. Do not process this type of renaming because it does not
-- use the actual value of the object.
if not Is_RTE (Typ, RE_Tag_Ptr) then
Search (Name (Ren_Decl));
end if;
return Ren_Obj;
end Find_Renamed_Object;
-- Local variables
Expr : Node_Id;
Ren_Obj : Entity_Id;
Stmt : Node_Id;
-- Start of processing for Is_Aliased
begin
-- A controlled transient object is not considered aliased when it
-- appears inside an expression_with_actions node even when there are
-- explicit aliases of it:
-- do
-- Trans_Id : Ctrl_Typ ...; -- transient object
-- Alias : ... := Trans_Id; -- object is aliased
-- Val : constant Boolean :=
-- ... Alias ...; -- aliasing ends
-- <finalize Trans_Id> -- object safe to finalize
-- in Val end;
-- Expansion ensures that all aliases are encapsulated in the actions
-- list and do not leak to the expression by forcing the evaluation
-- of the expression.
if Nkind (Rel_Node) = N_Expression_With_Actions then
return False;
-- Otherwise examine the statements after the controlled transient
-- object and look for various forms of aliasing.
else
Stmt := First_Stmt;
while Present (Stmt) loop
if Nkind (Stmt) = N_Object_Declaration then
Expr := Expression (Stmt);
-- Aliasing of the form:
-- Obj : ... := Trans_Id'reference;
if Present (Expr)
and then Nkind (Expr) = N_Reference
and then Nkind (Prefix (Expr)) = N_Identifier
and then Entity (Prefix (Expr)) = Trans_Id
then
return True;
end if;
elsif Nkind (Stmt) = N_Object_Renaming_Declaration then
Ren_Obj := Find_Renamed_Object (Stmt);
-- Aliasing of the form:
-- Obj : ... renames ... Trans_Id ...;
if Present (Ren_Obj) and then Ren_Obj = Trans_Id then
return True;
end if;
end if;
Next (Stmt);
end loop;
return False;
end if;
end Is_Aliased;
------------------
-- Is_Allocated --
------------------
function Is_Allocated (Trans_Id : Entity_Id) return Boolean is
Expr : constant Node_Id := Expression (Parent (Trans_Id));
begin
return
Is_Access_Type (Etype (Trans_Id))
and then Present (Expr)
and then Nkind (Expr) = N_Allocator;
end Is_Allocated;
---------------------------
-- Is_Iterated_Container --
---------------------------
function Is_Iterated_Container
(Trans_Id : Entity_Id;
First_Stmt : Node_Id) return Boolean
is
Aspect : Node_Id;
Call : Node_Id;
Iter : Entity_Id;
Param : Node_Id;
Stmt : Node_Id;
Typ : Entity_Id;
begin
-- It is not possible to iterate over containers in non-Ada 2012 code
if Ada_Version < Ada_2012 then
return False;
end if;
Typ := Etype (Trans_Id);
-- Handle access type created for secondary stack use
if Is_Access_Type (Typ) then
Typ := Designated_Type (Typ);
end if;
-- Look for aspect Default_Iterator. It may be part of a type
-- declaration for a container, or inherited from a base type
-- or parent type.
Aspect := Find_Value_Of_Aspect (Typ, Aspect_Default_Iterator);
if Present (Aspect) then
Iter := Entity (Aspect);
-- Examine the statements following the container object and
-- look for a call to the default iterate routine where the
-- first parameter is the transient. Such a call appears as:
-- It : Access_To_CW_Iterator :=
-- Iterate (Tran_Id.all, ...)'reference;
Stmt := First_Stmt;
while Present (Stmt) loop
-- Detect an object declaration which is initialized by a
-- secondary stack function call.
if Nkind (Stmt) = N_Object_Declaration
and then Present (Expression (Stmt))
and then Nkind (Expression (Stmt)) = N_Reference
and then Nkind (Prefix (Expression (Stmt))) = N_Function_Call
then
Call := Prefix (Expression (Stmt));
-- The call must invoke the default iterate routine of
-- the container and the transient object must appear as
-- the first actual parameter. Skip any calls whose names
-- are not entities.
if Is_Entity_Name (Name (Call))
and then Entity (Name (Call)) = Iter
and then Present (Parameter_Associations (Call))
then
Param := First (Parameter_Associations (Call));
if Nkind (Param) = N_Explicit_Dereference
and then Entity (Prefix (Param)) = Trans_Id
then
return True;
end if;
end if;
end if;
Next (Stmt);
end loop;
end if;
return False;
end Is_Iterated_Container;
-------------------------------------
-- Is_Part_Of_BIP_Return_Statement --
-------------------------------------
function Is_Part_Of_BIP_Return_Statement (N : Node_Id) return Boolean is
Subp : constant Entity_Id := Current_Subprogram;
Context : Node_Id;
begin
-- First check if N is part of a BIP function
if No (Subp)
or else not Is_Build_In_Place_Function (Subp)
then
return False;
end if;
-- Then check whether N is a complete part of a return statement
-- Should we consider other node kinds to go up the tree???
Context := N;
loop
case Nkind (Context) is
when N_Expression_With_Actions => Context := Parent (Context);
when N_Simple_Return_Statement => return True;
when others => return False;
end case;
end loop;
end Is_Part_Of_BIP_Return_Statement;
-- Local variables
Desig : Entity_Id := Obj_Typ;
-- Start of processing for Is_Finalizable_Transient
begin
-- Handle access types
if Is_Access_Type (Desig) then
Desig := Available_View (Designated_Type (Desig));
end if;
return
Ekind (Obj_Id) in E_Constant | E_Variable
and then Needs_Finalization (Desig)
and then Requires_Transient_Scope (Desig)
and then Nkind (Rel_Node) /= N_Simple_Return_Statement
and then not Is_Part_Of_BIP_Return_Statement (Rel_Node)
-- Do not consider a transient object that was already processed
and then not Is_Finalized_Transient (Obj_Id)
-- Do not consider renamed or 'reference-d transient objects because
-- the act of renaming extends the object's lifetime.
and then not Is_Aliased (Obj_Id, Decl)
-- Do not consider transient objects allocated on the heap since
-- they are attached to a finalization master.
and then not Is_Allocated (Obj_Id)
-- If the transient object is a pointer, check that it is not
-- initialized by a function that returns a pointer or acts as a
-- renaming of another pointer.
and then not
(Is_Access_Type (Obj_Typ) and then Initialized_By_Access (Obj_Id))
-- Do not consider transient objects which act as indirect aliases
-- of build-in-place function results.
and then not Initialized_By_Aliased_BIP_Func_Call (Obj_Id)
-- Do not consider conversions of tags to class-wide types
and then not Is_Tag_To_Class_Wide_Conversion (Obj_Id)
-- Do not consider iterators because those are treated as normal
-- controlled objects and are processed by the usual finalization
-- machinery. This avoids the double finalization of an iterator.
and then not Is_Iterator (Desig)
-- Do not consider containers in the context of iterator loops. Such
-- transient objects must exist for as long as the loop is around,
-- otherwise any operation carried out by the iterator will fail.
and then not Is_Iterated_Container (Obj_Id, Decl);
end Is_Finalizable_Transient;
---------------------------------
-- Is_Fully_Repped_Tagged_Type --
---------------------------------
function Is_Fully_Repped_Tagged_Type (T : Entity_Id) return Boolean is
U : constant Entity_Id := Underlying_Type (T);
Comp : Entity_Id;
begin
if No (U) or else not Is_Tagged_Type (U) then
return False;
elsif Has_Discriminants (U) then
return False;
elsif not Has_Specified_Layout (U) then
return False;
end if;
-- Here we have a tagged type, see if it has any component (other than
-- tag and parent) with no component_clause. If so, we return False.
Comp := First_Component (U);
while Present (Comp) loop
if not Is_Tag (Comp)
and then Chars (Comp) /= Name_uParent
and then No (Component_Clause (Comp))
then
return False;
else
Next_Component (Comp);
end if;
end loop;
-- All components have clauses
return True;
end Is_Fully_Repped_Tagged_Type;
----------------------------------
-- Is_Library_Level_Tagged_Type --
----------------------------------
function Is_Library_Level_Tagged_Type (Typ : Entity_Id) return Boolean is
begin
return Is_Tagged_Type (Typ) and then Is_Library_Level_Entity (Typ);
end Is_Library_Level_Tagged_Type;
--------------------------
-- Is_Non_BIP_Func_Call --
--------------------------
function Is_Non_BIP_Func_Call (Expr : Node_Id) return Boolean is
begin
-- The expected call is of the format
--
-- Func_Call'reference
return
Nkind (Expr) = N_Reference
and then Nkind (Prefix (Expr)) = N_Function_Call
and then not Is_Build_In_Place_Function_Call (Prefix (Expr));
end Is_Non_BIP_Func_Call;
----------------------------------
-- Is_Possibly_Unaligned_Object --
----------------------------------
function Is_Possibly_Unaligned_Object (N : Node_Id) return Boolean is
T : constant Entity_Id := Etype (N);
begin
-- If renamed object, apply test to underlying object
if Is_Entity_Name (N)
and then Is_Object (Entity (N))
and then Present (Renamed_Object (Entity (N)))
then
return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (N)));
end if;
-- Tagged and controlled types and aliased types are always aligned, as
-- are concurrent types.
if Is_Aliased (T)
or else Has_Controlled_Component (T)
or else Is_Concurrent_Type (T)
or else Is_Tagged_Type (T)
or else Is_Controlled (T)
then
return False;
end if;
-- If this is an element of a packed array, may be unaligned
if Is_Ref_To_Bit_Packed_Array (N) then
return True;
end if;
-- Case of indexed component reference: test whether prefix is unaligned
if Nkind (N) = N_Indexed_Component then
return Is_Possibly_Unaligned_Object (Prefix (N));
-- Case of selected component reference
elsif Nkind (N) = N_Selected_Component then
declare
P : constant Node_Id := Prefix (N);
C : constant Entity_Id := Entity (Selector_Name (N));
M : Nat;
S : Nat;
begin
-- If component reference is for an array with nonstatic bounds,
-- then it is always aligned: we can only process unaligned arrays
-- with static bounds (more precisely compile time known bounds).
if Is_Array_Type (T)
and then not Compile_Time_Known_Bounds (T)
then
return False;
end if;
-- If component is aliased, it is definitely properly aligned
if Is_Aliased (C) then
return False;
end if;
-- If component is for a type implemented as a scalar, and the
-- record is packed, and the component is other than the first
-- component of the record, then the component may be unaligned.
if Is_Packed (Etype (P))
and then Represented_As_Scalar (Etype (C))
and then First_Entity (Scope (C)) /= C
then
return True;
end if;
-- Compute maximum possible alignment for T
-- If alignment is known, then that settles things
if Known_Alignment (T) then
M := UI_To_Int (Alignment (T));
-- If alignment is not known, tentatively set max alignment
else
M := Ttypes.Maximum_Alignment;
-- We can reduce this if the Esize is known since the default
-- alignment will never be more than the smallest power of 2
-- that does not exceed this Esize value.
if Known_Esize (T) then
S := UI_To_Int (Esize (T));
while (M / 2) >= S loop
M := M / 2;
end loop;
end if;
end if;
-- Case of component clause present which may specify an
-- unaligned position.
if Present (Component_Clause (C)) then
-- Otherwise we can do a test to make sure that the actual
-- start position in the record, and the length, are both
-- consistent with the required alignment. If not, we know
-- that we are unaligned.
declare
Align_In_Bits : constant Nat := M * System_Storage_Unit;
Comp : Entity_Id;
begin
Comp := C;
-- For a component inherited in a record extension, the
-- clause is inherited but position and size are not set.
if Is_Base_Type (Etype (P))
and then Is_Tagged_Type (Etype (P))
and then Present (Original_Record_Component (Comp))
then
Comp := Original_Record_Component (Comp);
end if;
if Component_Bit_Offset (Comp) mod Align_In_Bits /= 0
or else Esize (Comp) mod Align_In_Bits /= 0
then
return True;
end if;
end;
end if;
-- Otherwise, for a component reference, test prefix
return Is_Possibly_Unaligned_Object (P);
end;
-- If not a component reference, must be aligned
else
return False;
end if;
end Is_Possibly_Unaligned_Object;
---------------------------------
-- Is_Possibly_Unaligned_Slice --
---------------------------------
function Is_Possibly_Unaligned_Slice (N : Node_Id) return Boolean is
begin
-- Go to renamed object
if Is_Entity_Name (N)
and then Is_Object (Entity (N))
and then Present (Renamed_Object (Entity (N)))
then
return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (N)));
end if;
-- The reference must be a slice
if Nkind (N) /= N_Slice then
return False;
end if;
-- If it is a slice, then look at the array type being sliced
declare
Sarr : constant Node_Id := Prefix (N);
-- Prefix of the slice, i.e. the array being sliced
Styp : constant Entity_Id := Etype (Prefix (N));
-- Type of the array being sliced
Pref : Node_Id;
Ptyp : Entity_Id;
begin
-- The problems arise if the array object that is being sliced
-- is a component of a record or array, and we cannot guarantee
-- the alignment of the array within its containing object.
-- To investigate this, we look at successive prefixes to see
-- if we have a worrisome indexed or selected component.
Pref := Sarr;
loop
-- Case of array is part of an indexed component reference
if Nkind (Pref) = N_Indexed_Component then
Ptyp := Etype (Prefix (Pref));
-- The only problematic case is when the array is packed, in
-- which case we really know nothing about the alignment of
-- individual components.
if Is_Bit_Packed_Array (Ptyp) then
return True;
end if;
-- Case of array is part of a selected component reference
elsif Nkind (Pref) = N_Selected_Component then
Ptyp := Etype (Prefix (Pref));
-- We are definitely in trouble if the record in question
-- has an alignment, and either we know this alignment is
-- inconsistent with the alignment of the slice, or we don't
-- know what the alignment of the slice should be. But this
-- really matters only if the target has strict alignment.
if Target_Strict_Alignment
and then Known_Alignment (Ptyp)
and then (not Known_Alignment (Styp)
or else Alignment (Styp) > Alignment (Ptyp))
then
return True;
end if;
-- We are in potential trouble if the record type is packed.
-- We could special case when we know that the array is the
-- first component, but that's not such a simple case ???
if Is_Packed (Ptyp) then
return True;
end if;
-- We are in trouble if there is a component clause, and
-- either we do not know the alignment of the slice, or
-- the alignment of the slice is inconsistent with the
-- bit position specified by the component clause.
declare
Field : constant Entity_Id := Entity (Selector_Name (Pref));
begin
if Present (Component_Clause (Field))
and then
(not Known_Alignment (Styp)
or else
(Component_Bit_Offset (Field) mod
(System_Storage_Unit * Alignment (Styp))) /= 0)
then
return True;
end if;
end;
-- For cases other than selected or indexed components we know we
-- are OK, since no issues arise over alignment.
else
return False;
end if;
-- We processed an indexed component or selected component
-- reference that looked safe, so keep checking prefixes.
Pref := Prefix (Pref);
end loop;
end;
end Is_Possibly_Unaligned_Slice;
-------------------------------
-- Is_Related_To_Func_Return --
-------------------------------
function Is_Related_To_Func_Return (Id : Entity_Id) return Boolean is
Expr : constant Node_Id := Related_Expression (Id);
begin
-- In the case of a function with a class-wide result that returns
-- a call to a function with a specific result, we introduce a
-- type conversion for the return expression. We do not want that
-- type conversion to influence the result of this function.
return
Present (Expr)
and then Nkind (Unqual_Conv (Expr)) = N_Explicit_Dereference
and then Nkind (Parent (Expr)) = N_Simple_Return_Statement;
end Is_Related_To_Func_Return;
--------------------------------
-- Is_Ref_To_Bit_Packed_Array --
--------------------------------
function Is_Ref_To_Bit_Packed_Array (N : Node_Id) return Boolean is
Result : Boolean;
Expr : Node_Id;
begin
if Is_Entity_Name (N)
and then Is_Object (Entity (N))
and then Present (Renamed_Object (Entity (N)))
then
return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (N)));
end if;
if Nkind (N) in N_Indexed_Component | N_Selected_Component then
if Is_Bit_Packed_Array (Etype (Prefix (N))) then
Result := True;
else
Result := Is_Ref_To_Bit_Packed_Array (Prefix (N));
end if;
if Result and then Nkind (N) = N_Indexed_Component then
Expr := First (Expressions (N));
while Present (Expr) loop
Force_Evaluation (Expr);
Next (Expr);
end loop;
end if;
return Result;
else
return False;
end if;
end Is_Ref_To_Bit_Packed_Array;
--------------------------------
-- Is_Ref_To_Bit_Packed_Slice --
--------------------------------
function Is_Ref_To_Bit_Packed_Slice (N : Node_Id) return Boolean is
begin
if Nkind (N) = N_Type_Conversion then
return Is_Ref_To_Bit_Packed_Slice (Expression (N));
elsif Is_Entity_Name (N)
and then Is_Object (Entity (N))
and then Present (Renamed_Object (Entity (N)))
then
return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (N)));
elsif Nkind (N) = N_Slice
and then Is_Bit_Packed_Array (Etype (Prefix (N)))
then
return True;
elsif Nkind (N) in N_Indexed_Component | N_Selected_Component then
return Is_Ref_To_Bit_Packed_Slice (Prefix (N));
else
return False;
end if;
end Is_Ref_To_Bit_Packed_Slice;
-----------------------
-- Is_Renamed_Object --
-----------------------
function Is_Renamed_Object (N : Node_Id) return Boolean is
Pnod : constant Node_Id := Parent (N);
Kind : constant Node_Kind := Nkind (Pnod);
begin
if Kind = N_Object_Renaming_Declaration then
return True;
elsif Kind in N_Indexed_Component | N_Selected_Component then
return Is_Renamed_Object (Pnod);
else
return False;
end if;
end Is_Renamed_Object;
--------------------------------------
-- Is_Secondary_Stack_BIP_Func_Call --
--------------------------------------
function Is_Secondary_Stack_BIP_Func_Call (Expr : Node_Id) return Boolean is
Actual : Node_Id;
Call : Node_Id := Expr;
Formal : Node_Id;
Param : Node_Id;
begin
-- Build-in-place calls usually appear in 'reference format. Note that
-- the accessibility check machinery may add an extra 'reference due to
-- side effect removal.
while Nkind (Call) = N_Reference loop
Call := Prefix (Call);
end loop;
Call := Unqual_Conv (Call);
if Is_Build_In_Place_Function_Call (Call) then
-- Examine all parameter associations of the function call
Param := First (Parameter_Associations (Call));
while Present (Param) loop
if Nkind (Param) = N_Parameter_Association then
Formal := Selector_Name (Param);
Actual := Explicit_Actual_Parameter (Param);
-- A match for BIPalloc => 2 has been found
if Is_Build_In_Place_Entity (Formal)
and then BIP_Suffix_Kind (Formal) = BIP_Alloc_Form
and then Nkind (Actual) = N_Integer_Literal
and then Intval (Actual) = Uint_2
then
return True;
end if;
end if;
Next (Param);
end loop;
end if;
return False;
end Is_Secondary_Stack_BIP_Func_Call;
-------------------------------------
-- Is_Tag_To_Class_Wide_Conversion --
-------------------------------------
function Is_Tag_To_Class_Wide_Conversion
(Obj_Id : Entity_Id) return Boolean
is
Expr : constant Node_Id := Expression (Parent (Obj_Id));
begin
return
Is_Class_Wide_Type (Etype (Obj_Id))
and then Present (Expr)
and then Nkind (Expr) = N_Unchecked_Type_Conversion
and then Is_RTE (Etype (Expression (Expr)), RE_Tag);
end Is_Tag_To_Class_Wide_Conversion;
--------------------------------
-- Is_Uninitialized_Aggregate --
--------------------------------
function Is_Uninitialized_Aggregate
(Exp : Node_Id;
T : Entity_Id) return Boolean
is
Comp : Node_Id;
Comp_Type : Entity_Id;
Typ : Entity_Id;
begin
if Nkind (Exp) /= N_Aggregate then
return False;
end if;
Preanalyze_And_Resolve (Exp, T);
Typ := Etype (Exp);
if No (Typ)
or else Ekind (Typ) /= E_Array_Subtype
or else Present (Expressions (Exp))
or else No (Component_Associations (Exp))
then
return False;
else
Comp_Type := Component_Type (Typ);
Comp := First (Component_Associations (Exp));
if not Box_Present (Comp)
or else Present (Next (Comp))
then
return False;
end if;
return Is_Scalar_Type (Comp_Type)
and then No (Default_Aspect_Component_Value (Typ));
end if;
end Is_Uninitialized_Aggregate;
----------------------------
-- Is_Untagged_Derivation --
----------------------------
function Is_Untagged_Derivation (T : Entity_Id) return Boolean is
begin
return (not Is_Tagged_Type (T) and then Is_Derived_Type (T))
or else
(Is_Private_Type (T) and then Present (Full_View (T))
and then not Is_Tagged_Type (Full_View (T))
and then Is_Derived_Type (Full_View (T))
and then Etype (Full_View (T)) /= T);
end Is_Untagged_Derivation;
------------------------------------
-- Is_Untagged_Private_Derivation --
------------------------------------
function Is_Untagged_Private_Derivation
(Priv_Typ : Entity_Id;
Full_Typ : Entity_Id) return Boolean
is
begin
return
Present (Priv_Typ)
and then Is_Untagged_Derivation (Priv_Typ)
and then Is_Private_Type (Etype (Priv_Typ))
and then Present (Full_Typ)
and then Is_Itype (Full_Typ);
end Is_Untagged_Private_Derivation;
------------------------------
-- Is_Verifiable_DIC_Pragma --
------------------------------
function Is_Verifiable_DIC_Pragma (Prag : Node_Id) return Boolean is
Args : constant List_Id := Pragma_Argument_Associations (Prag);
begin
-- To qualify as verifiable, a DIC pragma must have a non-null argument
return
Present (Args)
-- If there are args, but the first arg is Empty, then treat the
-- pragma the same as having no args (there may be a second arg that
-- is an implicitly added type arg, and Empty is a placeholder).
and then Present (Get_Pragma_Arg (First (Args)))
and then Nkind (Get_Pragma_Arg (First (Args))) /= N_Null;
end Is_Verifiable_DIC_Pragma;
---------------------------
-- Is_Volatile_Reference --
---------------------------
function Is_Volatile_Reference (N : Node_Id) return Boolean is
begin
-- Only source references are to be treated as volatile, internally
-- generated stuff cannot have volatile external effects.
if not Comes_From_Source (N) then
return False;
-- Never true for reference to a type
elsif Is_Entity_Name (N) and then Is_Type (Entity (N)) then
return False;
-- Never true for a compile time known constant
elsif Compile_Time_Known_Value (N) then
return False;
-- True if object reference with volatile type
elsif Is_Volatile_Object_Ref (N) then
return True;
-- True if reference to volatile entity
elsif Is_Entity_Name (N) then
return Treat_As_Volatile (Entity (N));
-- True for slice of volatile array
elsif Nkind (N) = N_Slice then
return Is_Volatile_Reference (Prefix (N));
-- True if volatile component
elsif Nkind (N) in N_Indexed_Component | N_Selected_Component then
if (Is_Entity_Name (Prefix (N))
and then Has_Volatile_Components (Entity (Prefix (N))))
or else (Present (Etype (Prefix (N)))
and then Has_Volatile_Components (Etype (Prefix (N))))
then
return True;
else
return Is_Volatile_Reference (Prefix (N));
end if;
-- Otherwise false
else
return False;
end if;
end Is_Volatile_Reference;
--------------------
-- Kill_Dead_Code --
--------------------
procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is
W : Boolean := Warn;
-- Set False if warnings suppressed
begin
if Present (N) then
Remove_Warning_Messages (N);
-- Update the internal structures of the ABE mechanism in case the
-- dead node is an elaboration scenario.
Kill_Elaboration_Scenario (N);
-- Generate warning if appropriate
if W then
-- We suppress the warning if this code is under control of an
-- if/case statement and either
-- a) we are in an instance and the condition/selector
-- has a statically known value; or
-- b) the condition/selector is a simple identifier and
-- warnings off is set for this identifier.
-- Dead code is common and reasonable in instances, so we don't
-- want a warning in that case.
declare
C : Node_Id := Empty;
begin
if Nkind (Parent (N)) = N_If_Statement then
C := Condition (Parent (N));
elsif Nkind (Parent (N)) = N_Case_Statement_Alternative then
C := Expression (Parent (Parent (N)));
end if;
if Present (C) then
if (In_Instance and Compile_Time_Known_Value (C))
or else (Nkind (C) = N_Identifier
and then Present (Entity (C))
and then Has_Warnings_Off (Entity (C)))
then
W := False;
end if;
end if;
end;
-- Generate warning if not suppressed
if W then
Error_Msg_F
("?t?this code can never be executed and has been deleted!",
N);
end if;
end if;
-- Recurse into block statements and bodies to process declarations
-- and statements.
if Nkind (N) = N_Block_Statement
or else Nkind (N) = N_Subprogram_Body
or else Nkind (N) = N_Package_Body
then
Kill_Dead_Code (Declarations (N), False);
Kill_Dead_Code (Statements (Handled_Statement_Sequence (N)));
if Nkind (N) = N_Subprogram_Body then
Set_Is_Eliminated (Defining_Entity (N));
end if;
elsif Nkind (N) = N_Package_Declaration then
Kill_Dead_Code (Visible_Declarations (Specification (N)));
Kill_Dead_Code (Private_Declarations (Specification (N)));
-- ??? After this point, Delete_Tree has been called on all
-- declarations in Specification (N), so references to entities
-- therein look suspicious.
declare
E : Entity_Id := First_Entity (Defining_Entity (N));
begin
while Present (E) loop
if Ekind (E) = E_Operator then
Set_Is_Eliminated (E);
end if;
Next_Entity (E);
end loop;
end;
-- Recurse into composite statement to kill individual statements in
-- particular instantiations.
elsif Nkind (N) = N_If_Statement then
Kill_Dead_Code (Then_Statements (N));
Kill_Dead_Code (Elsif_Parts (N));
Kill_Dead_Code (Else_Statements (N));
elsif Nkind (N) = N_Loop_Statement then
Kill_Dead_Code (Statements (N));
elsif Nkind (N) = N_Case_Statement then
declare
Alt : Node_Id;
begin
Alt := First (Alternatives (N));
while Present (Alt) loop
Kill_Dead_Code (Statements (Alt));
Next (Alt);
end loop;
end;
elsif Nkind (N) = N_Case_Statement_Alternative then
Kill_Dead_Code (Statements (N));
-- Deal with dead instances caused by deleting instantiations
elsif Nkind (N) in N_Generic_Instantiation then
Remove_Dead_Instance (N);
end if;
end if;
end Kill_Dead_Code;
-- Case where argument is a list of nodes to be killed
procedure Kill_Dead_Code (L : List_Id; Warn : Boolean := False) is
N : Node_Id;
W : Boolean;
begin
W := Warn;
if Is_Non_Empty_List (L) then
N := First (L);
while Present (N) loop
Kill_Dead_Code (N, W);
W := False;
Next (N);
end loop;
end if;
end Kill_Dead_Code;
-----------------------------
-- Make_CW_Equivalent_Type --
-----------------------------
-- Create a record type used as an equivalent of any member of the class
-- which takes its size from exp.
-- Generate the following code:
-- type Equiv_T is record
-- _parent : T (List of discriminant constraints taken from Exp);
-- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8);
-- end Equiv_T;
--
-- ??? Note that this type does not guarantee same alignment as all
-- derived types
--
-- Note: for the freezing circuitry, this looks like a record extension,
-- and so we need to make sure that the scalar storage order is the same
-- as that of the parent type. (This does not change anything for the
-- representation of the extension part.)
function Make_CW_Equivalent_Type
(T : Entity_Id;
E : Node_Id) return Entity_Id
is
Loc : constant Source_Ptr := Sloc (E);
Root_Typ : constant Entity_Id := Root_Type (T);
Root_Utyp : constant Entity_Id := Underlying_Type (Root_Typ);
List_Def : constant List_Id := Empty_List;
Comp_List : constant List_Id := New_List;
Equiv_Type : Entity_Id;
Range_Type : Entity_Id;
Str_Type : Entity_Id;
Constr_Root : Entity_Id;
Sizexpr : Node_Id;
begin
-- If the root type is already constrained, there are no discriminants
-- in the expression.
if not Has_Discriminants (Root_Typ)
or else Is_Constrained (Root_Typ)
then
Constr_Root := Root_Typ;
-- At this point in the expansion, nonlimited view of the type
-- must be available, otherwise the error will be reported later.
if From_Limited_With (Constr_Root)
and then Present (Non_Limited_View (Constr_Root))
then
Constr_Root := Non_Limited_View (Constr_Root);
end if;
else
Constr_Root := Make_Temporary (Loc, 'R');
-- subtype cstr__n is T (List of discr constraints taken from Exp)
Append_To (List_Def,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Constr_Root,
Subtype_Indication => Make_Subtype_From_Expr (E, Root_Typ)));
end if;
-- Generate the range subtype declaration
Range_Type := Make_Temporary (Loc, 'G');
if not Is_Interface (Root_Typ) then
-- subtype rg__xx is
-- Storage_Offset range 1 .. (Expr'size - typ'size) / Storage_Unit
Sizexpr :=
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix =>
OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
Attribute_Name => Name_Size),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Constr_Root, Loc),
Attribute_Name => Name_Object_Size));
else
-- subtype rg__xx is
-- Storage_Offset range 1 .. Expr'size / Storage_Unit
Sizexpr :=
Make_Attribute_Reference (Loc,
Prefix =>
OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
Attribute_Name => Name_Size);
end if;
Set_Paren_Count (Sizexpr, 1);
Append_To (List_Def,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Range_Type,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (RTE (RE_Storage_Offset), Loc),
Constraint => Make_Range_Constraint (Loc,
Range_Expression =>
Make_Range (Loc,
Low_Bound => Make_Integer_Literal (Loc, 1),
High_Bound =>
Make_Op_Divide (Loc,
Left_Opnd => Sizexpr,
Right_Opnd => Make_Integer_Literal (Loc,
Intval => System_Storage_Unit)))))));
-- subtype str__nn is Storage_Array (rg__x);
Str_Type := Make_Temporary (Loc, 'S');
Append_To (List_Def,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Str_Type,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (RTE (RE_Storage_Array), Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints =>
New_List (New_Occurrence_Of (Range_Type, Loc))))));
-- type Equiv_T is record
-- [ _parent : Tnn; ]
-- E : Str_Type;
-- end Equiv_T;
Equiv_Type := Make_Temporary (Loc, 'T');
Mutate_Ekind (Equiv_Type, E_Record_Type);
Set_Parent_Subtype (Equiv_Type, Constr_Root);
-- Set Is_Class_Wide_Equivalent_Type very early to trigger the special
-- treatment for this type. In particular, even though _parent's type
-- is a controlled type or contains controlled components, we do not
-- want to set Has_Controlled_Component on it to avoid making it gain
-- an unwanted _controller component.
Set_Is_Class_Wide_Equivalent_Type (Equiv_Type);
-- A class-wide equivalent type does not require initialization
Set_Suppress_Initialization (Equiv_Type);
if not Is_Interface (Root_Typ) then
Append_To (Comp_List,
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uParent),
Component_Definition =>
Make_Component_Definition (Loc,
Aliased_Present => False,
Subtype_Indication => New_Occurrence_Of (Constr_Root, Loc))));
Set_Reverse_Storage_Order
(Equiv_Type, Reverse_Storage_Order (Base_Type (Root_Utyp)));
Set_Reverse_Bit_Order
(Equiv_Type, Reverse_Bit_Order (Base_Type (Root_Utyp)));
end if;
Append_To (Comp_List,
Make_Component_Declaration (Loc,
Defining_Identifier => Make_Temporary (Loc, 'C'),
Component_Definition =>
Make_Component_Definition (Loc,
Aliased_Present => False,
Subtype_Indication => New_Occurrence_Of (Str_Type, Loc))));
Append_To (List_Def,
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Equiv_Type,
Type_Definition =>
Make_Record_Definition (Loc,
Component_List =>
Make_Component_List (Loc,
Component_Items => Comp_List,
Variant_Part => Empty))));
-- Suppress all checks during the analysis of the expanded code to avoid
-- the generation of spurious warnings under ZFP run-time.
Insert_Actions (E, List_Def, Suppress => All_Checks);
return Equiv_Type;
end Make_CW_Equivalent_Type;
-------------------------
-- Make_Invariant_Call --
-------------------------
function Make_Invariant_Call (Expr : Node_Id) return Node_Id is
Loc : constant Source_Ptr := Sloc (Expr);
Typ : constant Entity_Id := Base_Type (Etype (Expr));
pragma Assert (Has_Invariants (Typ));
Proc_Id : constant Entity_Id := Invariant_Procedure (Typ);
pragma Assert (Present (Proc_Id));
begin
-- The invariant procedure has a null body if assertions are disabled or
-- Assertion_Policy Ignore is in effect. In that case, generate a null
-- statement instead of a call to the invariant procedure.
if Has_Null_Body (Proc_Id) then
return Make_Null_Statement (Loc);
else
return
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Proc_Id, Loc),
Parameter_Associations => New_List (Relocate_Node (Expr)));
end if;
end Make_Invariant_Call;
------------------------
-- Make_Literal_Range --
------------------------
function Make_Literal_Range
(Loc : Source_Ptr;
Literal_Typ : Entity_Id) return Node_Id
is
Lo : constant Node_Id :=
New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ));
Index : constant Entity_Id := Etype (Lo);
Length_Expr : constant Node_Id :=
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Integer_Literal (Loc,
Intval => String_Literal_Length (Literal_Typ)),
Right_Opnd => Make_Integer_Literal (Loc, 1));
Hi : Node_Id;
begin
Set_Analyzed (Lo, False);
if Is_Integer_Type (Index) then
Hi :=
Make_Op_Add (Loc,
Left_Opnd => New_Copy_Tree (Lo),
Right_Opnd => Length_Expr);
else
Hi :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Val,
Prefix => New_Occurrence_Of (Index, Loc),
Expressions => New_List (
Make_Op_Add (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Pos,
Prefix => New_Occurrence_Of (Index, Loc),
Expressions => New_List (New_Copy_Tree (Lo))),
Right_Opnd => Length_Expr)));
end if;
return
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi);
end Make_Literal_Range;
--------------------------
-- Make_Non_Empty_Check --
--------------------------
function Make_Non_Empty_Check
(Loc : Source_Ptr;
N : Node_Id) return Node_Id
is
begin
return
Make_Op_Ne (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix => Duplicate_Subexpr_No_Checks (N, Name_Req => True)),
Right_Opnd =>
Make_Integer_Literal (Loc, 0));
end Make_Non_Empty_Check;
-------------------------
-- Make_Predicate_Call --
-------------------------
-- WARNING: This routine manages Ghost regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- Ghost mode.
function Make_Predicate_Call
(Typ : Entity_Id;
Expr : Node_Id;
Mem : Boolean := False) return Node_Id
is
Loc : constant Source_Ptr := Sloc (Expr);
Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
Saved_IGR : constant Node_Id := Ignored_Ghost_Region;
-- Save the Ghost-related attributes to restore on exit
Call : Node_Id;
Func_Id : Entity_Id;
begin
Func_Id := Predicate_Function (Typ);
pragma Assert (Present (Func_Id));
-- The related type may be subject to pragma Ghost. Set the mode now to
-- ensure that the call is properly marked as Ghost.
Set_Ghost_Mode (Typ);
-- Call special membership version if requested and available
if Mem and then Present (Predicate_Function_M (Typ)) then
Func_Id := Predicate_Function_M (Typ);
end if;
-- Case of calling normal predicate function
-- If the type is tagged, the expression may be class-wide, in which
-- case it has to be converted to its root type, given that the
-- generated predicate function is not dispatching. The conversion is
-- type-safe and does not need validation, which matters when private
-- extensions are involved.
if Is_Tagged_Type (Typ) then
Call :=
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Func_Id, Loc),
Parameter_Associations =>
New_List (OK_Convert_To (Typ, Relocate_Node (Expr))));
else
Call :=
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Func_Id, Loc),
Parameter_Associations => New_List (Relocate_Node (Expr)));
end if;
Restore_Ghost_Region (Saved_GM, Saved_IGR);
return Call;
end Make_Predicate_Call;
--------------------------
-- Make_Predicate_Check --
--------------------------
function Make_Predicate_Check
(Typ : Entity_Id;
Expr : Node_Id) return Node_Id
is
Loc : constant Source_Ptr := Sloc (Expr);
procedure Add_Failure_Expression (Args : List_Id);
-- Add the failure expression of pragma Predicate_Failure (if any) to
-- list Args.
----------------------------
-- Add_Failure_Expression --
----------------------------
procedure Add_Failure_Expression (Args : List_Id) is
function Failure_Expression return Node_Id;
pragma Inline (Failure_Expression);
-- Find aspect or pragma Predicate_Failure that applies to type Typ
-- and return its expression. Return Empty if no such annotation is
-- available.
function Is_OK_PF_Aspect (Asp : Node_Id) return Boolean;
pragma Inline (Is_OK_PF_Aspect);
-- Determine whether aspect Asp is a suitable Predicate_Failure
-- aspect that applies to type Typ.
function Is_OK_PF_Pragma (Prag : Node_Id) return Boolean;
pragma Inline (Is_OK_PF_Pragma);
-- Determine whether pragma Prag is a suitable Predicate_Failure
-- pragma that applies to type Typ.
procedure Replace_Subtype_Reference (N : Node_Id);
-- Replace the current instance of type Typ denoted by N with
-- expression Expr.
------------------------
-- Failure_Expression --
------------------------
function Failure_Expression return Node_Id is
Item : Node_Id;
begin
-- The management of the rep item chain involves "inheritance" of
-- parent type chains. If a parent [sub]type is already subject to
-- pragma Predicate_Failure, then the pragma will also appear in
-- the chain of the child [sub]type, which in turn may possess a
-- pragma of its own. Avoid order-dependent issues by inspecting
-- the rep item chain directly. Note that routine Get_Pragma may
-- return a parent pragma.
Item := First_Rep_Item (Typ);
while Present (Item) loop
-- Predicate_Failure appears as an aspect
if Nkind (Item) = N_Aspect_Specification
and then Is_OK_PF_Aspect (Item)
then
return Expression (Item);
-- Predicate_Failure appears as a pragma
elsif Nkind (Item) = N_Pragma
and then Is_OK_PF_Pragma (Item)
then
return
Get_Pragma_Arg
(Next (First (Pragma_Argument_Associations (Item))));
end if;
Next_Rep_Item (Item);
end loop;
return Empty;
end Failure_Expression;
---------------------
-- Is_OK_PF_Aspect --
---------------------
function Is_OK_PF_Aspect (Asp : Node_Id) return Boolean is
begin
-- To qualify, the aspect must apply to the type subjected to the
-- predicate check.
return
Chars (Identifier (Asp)) = Name_Predicate_Failure
and then Present (Entity (Asp))
and then Entity (Asp) = Typ;
end Is_OK_PF_Aspect;
---------------------
-- Is_OK_PF_Pragma --
---------------------
function Is_OK_PF_Pragma (Prag : Node_Id) return Boolean is
Args : constant List_Id := Pragma_Argument_Associations (Prag);
Typ_Arg : Node_Id;
begin
-- Nothing to do when the pragma does not denote Predicate_Failure
if Pragma_Name (Prag) /= Name_Predicate_Failure then
return False;
-- Nothing to do when the pragma lacks arguments, in which case it
-- is illegal.
elsif No (Args) or else Is_Empty_List (Args) then
return False;
end if;
Typ_Arg := Get_Pragma_Arg (First (Args));
-- To qualify, the local name argument of the pragma must denote
-- the type subjected to the predicate check.
return
Is_Entity_Name (Typ_Arg)
and then Present (Entity (Typ_Arg))
and then Entity (Typ_Arg) = Typ;
end Is_OK_PF_Pragma;
--------------------------------
-- Replace_Subtype_Reference --
--------------------------------
procedure Replace_Subtype_Reference (N : Node_Id) is
begin
Rewrite (N, New_Copy_Tree (Expr));
end Replace_Subtype_Reference;
procedure Replace_Subtype_References is
new Replace_Type_References_Generic (Replace_Subtype_Reference);
-- Local variables
PF_Expr : constant Node_Id := Failure_Expression;
Expr : Node_Id;
-- Start of processing for Add_Failure_Expression
begin
if Present (PF_Expr) then
-- Replace any occurrences of the current instance of the type
-- with the object subjected to the predicate check.
Expr := New_Copy_Tree (PF_Expr);
Replace_Subtype_References (Expr, Typ);
-- The failure expression appears as the third argument of the
-- Check pragma.
Append_To (Args,
Make_Pragma_Argument_Association (Loc,
Expression => Expr));
end if;
end Add_Failure_Expression;
-- Local variables
Args : List_Id;
Nam : Name_Id;
-- Start of processing for Make_Predicate_Check
begin
-- If predicate checks are suppressed, then return a null statement. For
-- this call, we check only the scope setting. If the caller wants to
-- check a specific entity's setting, they must do it manually.
if Predicate_Checks_Suppressed (Empty) then
return Make_Null_Statement (Loc);
end if;
-- Do not generate a check within stream functions and the like.
if not Predicate_Check_In_Scope (Expr) then
return Make_Null_Statement (Loc);
end if;
-- Compute proper name to use, we need to get this right so that the
-- right set of check policies apply to the Check pragma we are making.
if Has_Dynamic_Predicate_Aspect (Typ) then
Nam := Name_Dynamic_Predicate;
elsif Has_Static_Predicate_Aspect (Typ) then
Nam := Name_Static_Predicate;
else
Nam := Name_Predicate;
end if;
Args := New_List (
Make_Pragma_Argument_Association (Loc,
Expression => Make_Identifier (Loc, Nam)),
Make_Pragma_Argument_Association (Loc,
Expression => Make_Predicate_Call (Typ, Expr)));
-- If the subtype is subject to pragma Predicate_Failure, add the
-- failure expression as an additional parameter.
Add_Failure_Expression (Args);
return
Make_Pragma (Loc,
Chars => Name_Check,
Pragma_Argument_Associations => Args);
end Make_Predicate_Check;
----------------------------
-- Make_Subtype_From_Expr --
----------------------------
-- 1. If Expr is an unconstrained array expression, creates
-- Unc_Type(Expr'first(1)..Expr'last(1),..., Expr'first(n)..Expr'last(n))
-- 2. If Expr is a unconstrained discriminated type expression, creates
-- Unc_Type(Expr.Discr1, ... , Expr.Discr_n)
-- 3. If Expr is class-wide, creates an implicit class-wide subtype
function Make_Subtype_From_Expr
(E : Node_Id;
Unc_Typ : Entity_Id;
Related_Id : Entity_Id := Empty) return Node_Id
is
List_Constr : constant List_Id := New_List;
Loc : constant Source_Ptr := Sloc (E);
D : Entity_Id;
Full_Exp : Node_Id;
Full_Subtyp : Entity_Id;
High_Bound : Entity_Id;
Index_Typ : Entity_Id;
Low_Bound : Entity_Id;
Priv_Subtyp : Entity_Id;
Utyp : Entity_Id;
begin
if Is_Private_Type (Unc_Typ)
and then Has_Unknown_Discriminants (Unc_Typ)
then
-- The caller requests a unique external name for both the private
-- and the full subtype.
if Present (Related_Id) then
Full_Subtyp :=
Make_Defining_Identifier (Loc,
Chars => New_External_Name (Chars (Related_Id), 'C'));
Priv_Subtyp :=
Make_Defining_Identifier (Loc,
Chars => New_External_Name (Chars (Related_Id), 'P'));
else
Full_Subtyp := Make_Temporary (Loc, 'C');
Priv_Subtyp := Make_Temporary (Loc, 'P');
end if;
-- Prepare the subtype completion. Use the base type to find the
-- underlying type because the type may be a generic actual or an
-- explicit subtype.
Utyp := Underlying_Type (Base_Type (Unc_Typ));
Full_Exp :=
Unchecked_Convert_To (Utyp, Duplicate_Subexpr_No_Checks (E));
Set_Parent (Full_Exp, Parent (E));
Insert_Action (E,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Full_Subtyp,
Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp)));
-- Define the dummy private subtype
Mutate_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ)));
Set_Etype (Priv_Subtyp, Base_Type (Unc_Typ));
Set_Scope (Priv_Subtyp, Full_Subtyp);
Set_Is_Constrained (Priv_Subtyp);
Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ));
Set_Is_Itype (Priv_Subtyp);
Set_Associated_Node_For_Itype (Priv_Subtyp, E);
if Is_Tagged_Type (Priv_Subtyp) then
Set_Class_Wide_Type
(Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ));
Set_Direct_Primitive_Operations (Priv_Subtyp,
Direct_Primitive_Operations (Unc_Typ));
end if;
Set_Full_View (Priv_Subtyp, Full_Subtyp);
return New_Occurrence_Of (Priv_Subtyp, Loc);
elsif Is_Array_Type (Unc_Typ) then
Index_Typ := First_Index (Unc_Typ);
for J in 1 .. Number_Dimensions (Unc_Typ) loop
-- Capture the bounds of each index constraint in case the context
-- is an object declaration of an unconstrained type initialized
-- by a function call:
-- Obj : Unconstr_Typ := Func_Call;
-- This scenario requires secondary scope management and the index
-- constraint cannot depend on the temporary used to capture the
-- result of the function call.
-- SS_Mark;
-- Temp : Unconstr_Typ_Ptr := Func_Call'reference;
-- subtype S is Unconstr_Typ (Temp.all'First .. Temp.all'Last);
-- Obj : S := Temp.all;
-- SS_Release; -- Temp is gone at this point, bounds of S are
-- -- non existent.
-- Generate:
-- Low_Bound : constant Base_Type (Index_Typ) := E'First (J);
Low_Bound := Make_Temporary (Loc, 'B');
Insert_Action (E,
Make_Object_Declaration (Loc,
Defining_Identifier => Low_Bound,
Object_Definition =>
New_Occurrence_Of (Base_Type (Etype (Index_Typ)), Loc),
Constant_Present => True,
Expression =>
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr_No_Checks (E),
Attribute_Name => Name_First,
Expressions => New_List (
Make_Integer_Literal (Loc, J)))));
-- Generate:
-- High_Bound : constant Base_Type (Index_Typ) := E'Last (J);
High_Bound := Make_Temporary (Loc, 'B');
Insert_Action (E,
Make_Object_Declaration (Loc,
Defining_Identifier => High_Bound,
Object_Definition =>
New_Occurrence_Of (Base_Type (Etype (Index_Typ)), Loc),
Constant_Present => True,
Expression =>
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr_No_Checks (E),
Attribute_Name => Name_Last,
Expressions => New_List (
Make_Integer_Literal (Loc, J)))));
Append_To (List_Constr,
Make_Range (Loc,
Low_Bound => New_Occurrence_Of (Low_Bound, Loc),
High_Bound => New_Occurrence_Of (High_Bound, Loc)));
Next_Index (Index_Typ);
end loop;
elsif Is_Class_Wide_Type (Unc_Typ) then
declare
CW_Subtype : Entity_Id;
EQ_Typ : Entity_Id := Empty;
begin
-- A class-wide equivalent type is not needed on VM targets
-- because the VM back-ends handle the class-wide object
-- initialization itself (and doesn't need or want the
-- additional intermediate type to handle the assignment).
if Expander_Active and then Tagged_Type_Expansion then
-- If this is the class-wide type of a completion that is a
-- record subtype, set the type of the class-wide type to be
-- the full base type, for use in the expanded code for the
-- equivalent type. Should this be done earlier when the
-- completion is analyzed ???
if Is_Private_Type (Etype (Unc_Typ))
and then
Ekind (Full_View (Etype (Unc_Typ))) = E_Record_Subtype
then
Set_Etype (Unc_Typ, Base_Type (Full_View (Etype (Unc_Typ))));
end if;
EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E);
end if;
CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E);
Set_Equivalent_Type (CW_Subtype, EQ_Typ);
Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ));
return New_Occurrence_Of (CW_Subtype, Loc);
end;
-- Indefinite record type with discriminants
else
D := First_Discriminant (Unc_Typ);
while Present (D) loop
Append_To (List_Constr,
Make_Selected_Component (Loc,
Prefix => Duplicate_Subexpr_No_Checks (E),
Selector_Name => New_Occurrence_Of (D, Loc)));
Next_Discriminant (D);
end loop;
end if;
return
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Unc_Typ, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => List_Constr));
end Make_Subtype_From_Expr;
-----------------------------
-- Make_Variant_Comparison --
-----------------------------
function Make_Variant_Comparison
(Loc : Source_Ptr;
Mode : Name_Id;
Curr_Val : Node_Id;
Old_Val : Node_Id) return Node_Id
is
begin
if Mode = Name_Increases then
return Make_Op_Gt (Loc, Curr_Val, Old_Val);
else pragma Assert (Mode = Name_Decreases);
return Make_Op_Lt (Loc, Curr_Val, Old_Val);
end if;
end Make_Variant_Comparison;
-----------------
-- Map_Formals --
-----------------
procedure Map_Formals
(Parent_Subp : Entity_Id;
Derived_Subp : Entity_Id;
Force_Update : Boolean := False)
is
Par_Formal : Entity_Id := First_Formal (Parent_Subp);
Subp_Formal : Entity_Id := First_Formal (Derived_Subp);
begin
if Force_Update then
Type_Map.Set (Parent_Subp, Derived_Subp);
end if;
-- At this stage either we are under regular processing and the caller
-- has previously ensured that these primitives are already mapped (by
-- means of calling previously to Update_Primitives_Mapping), or we are
-- processing a late-overriding primitive and Force_Update updated above
-- the mapping of these primitives.
while Present (Par_Formal) and then Present (Subp_Formal) loop
Type_Map.Set (Par_Formal, Subp_Formal);
Next_Formal (Par_Formal);
Next_Formal (Subp_Formal);
end loop;
end Map_Formals;
---------------
-- Map_Types --
---------------
procedure Map_Types (Parent_Type : Entity_Id; Derived_Type : Entity_Id) is
-- NOTE: Most of the routines in Map_Types are intentionally unnested to
-- avoid deep indentation of code.
-- NOTE: Routines which deal with discriminant mapping operate on the
-- [underlying/record] full view of various types because those views
-- contain all discriminants and stored constraints.
procedure Add_Primitive (Prim : Entity_Id; Par_Typ : Entity_Id);
-- Subsidiary to Map_Primitives. Find a primitive in the inheritance or
-- overriding chain starting from Prim whose dispatching type is parent
-- type Par_Typ and add a mapping between the result and primitive Prim.
function Ancestor_Primitive (Subp : Entity_Id) return Entity_Id;
-- Subsidiary to Map_Primitives. Return the next ancestor primitive in
-- the inheritance or overriding chain of subprogram Subp. Return Empty
-- if no such primitive is available.
function Build_Chain
(Par_Typ : Entity_Id;
Deriv_Typ : Entity_Id) return Elist_Id;
-- Subsidiary to Map_Discriminants. Recreate the derivation chain from
-- parent type Par_Typ leading down towards derived type Deriv_Typ. The
-- list has the form:
--
-- head tail
-- v v
-- <Ancestor_N> -> <Ancestor_N-1> -> <Ancestor_1> -> Deriv_Typ
--
-- Note that Par_Typ is not part of the resulting derivation chain
function Discriminated_View (Typ : Entity_Id) return Entity_Id;
-- Return the view of type Typ which could potentially contains either
-- the discriminants or stored constraints of the type.
function Find_Discriminant_Value
(Discr : Entity_Id;
Par_Typ : Entity_Id;
Deriv_Typ : Entity_Id;
Typ_Elmt : Elmt_Id) return Node_Or_Entity_Id;
-- Subsidiary to Map_Discriminants. Find the value of discriminant Discr
-- in the derivation chain starting from parent type Par_Typ leading to
-- derived type Deriv_Typ. The returned value is one of the following:
--
-- * An entity which is either a discriminant or a nondiscriminant
-- name, and renames/constraints Discr.
--
-- * An expression which constraints Discr
--
-- Typ_Elmt is an element of the derivation chain created by routine
-- Build_Chain and denotes the current ancestor being examined.
procedure Map_Discriminants
(Par_Typ : Entity_Id;
Deriv_Typ : Entity_Id);
-- Map each discriminant of type Par_Typ to a meaningful constraint
-- from the point of view of type Deriv_Typ.
procedure Map_Primitives (Par_Typ : Entity_Id; Deriv_Typ : Entity_Id);
-- Map each primitive of type Par_Typ to a corresponding primitive of
-- type Deriv_Typ.
-------------------
-- Add_Primitive --
-------------------
procedure Add_Primitive (Prim : Entity_Id; Par_Typ : Entity_Id) is
Par_Prim : Entity_Id;
begin
-- Inspect the inheritance chain through the Alias attribute and the
-- overriding chain through the Overridden_Operation looking for an
-- ancestor primitive with the appropriate dispatching type.
Par_Prim := Prim;
while Present (Par_Prim) loop
exit when Find_Dispatching_Type (Par_Prim) = Par_Typ;
Par_Prim := Ancestor_Primitive (Par_Prim);
end loop;
-- Create a mapping of the form:
-- parent type primitive -> derived type primitive
if Present (Par_Prim) then
Type_Map.Set (Par_Prim, Prim);
end if;
end Add_Primitive;
------------------------
-- Ancestor_Primitive --
------------------------
function Ancestor_Primitive (Subp : Entity_Id) return Entity_Id is
Inher_Prim : constant Entity_Id := Alias (Subp);
Over_Prim : constant Entity_Id := Overridden_Operation (Subp);
begin
-- The current subprogram overrides an ancestor primitive
if Present (Over_Prim) then
return Over_Prim;
-- The current subprogram is an internally generated alias of an
-- inherited ancestor primitive.
elsif Present (Inher_Prim) then
return Inher_Prim;
-- Otherwise the current subprogram is the root of the inheritance or
-- overriding chain.
else
return Empty;
end if;
end Ancestor_Primitive;
-----------------
-- Build_Chain --
-----------------
function Build_Chain
(Par_Typ : Entity_Id;
Deriv_Typ : Entity_Id) return Elist_Id
is
Anc_Typ : Entity_Id;
Chain : Elist_Id;
Curr_Typ : Entity_Id;
begin
Chain := New_Elmt_List;
-- Add the derived type to the derivation chain
Prepend_Elmt (Deriv_Typ, Chain);
-- Examine all ancestors starting from the derived type climbing
-- towards parent type Par_Typ.
Curr_Typ := Deriv_Typ;
loop
-- Handle the case where the current type is a record which
-- derives from a subtype.
-- subtype Sub_Typ is Par_Typ ...
-- type Deriv_Typ is Sub_Typ ...
if Ekind (Curr_Typ) = E_Record_Type
and then Present (Parent_Subtype (Curr_Typ))
then
Anc_Typ := Parent_Subtype (Curr_Typ);
-- Handle the case where the current type is a record subtype of
-- another subtype.
-- subtype Sub_Typ1 is Par_Typ ...
-- subtype Sub_Typ2 is Sub_Typ1 ...
elsif Ekind (Curr_Typ) = E_Record_Subtype
and then Present (Cloned_Subtype (Curr_Typ))
then
Anc_Typ := Cloned_Subtype (Curr_Typ);
-- Otherwise use the direct parent type
else
Anc_Typ := Etype (Curr_Typ);
end if;
-- Use the first subtype when dealing with itypes
if Is_Itype (Anc_Typ) then
Anc_Typ := First_Subtype (Anc_Typ);
end if;
-- Work with the view which contains the discriminants and stored
-- constraints.
Anc_Typ := Discriminated_View (Anc_Typ);
-- Stop the climb when either the parent type has been reached or
-- there are no more ancestors left to examine.
exit when Anc_Typ = Curr_Typ or else Anc_Typ = Par_Typ;
Prepend_Unique_Elmt (Anc_Typ, Chain);
Curr_Typ := Anc_Typ;
end loop;
return Chain;
end Build_Chain;
------------------------
-- Discriminated_View --
------------------------
function Discriminated_View (Typ : Entity_Id) return Entity_Id is
T : Entity_Id;
begin
T := Typ;
-- Use the [underlying] full view when dealing with private types
-- because the view contains all inherited discriminants or stored
-- constraints.
if Is_Private_Type (T) then
if Present (Underlying_Full_View (T)) then
T := Underlying_Full_View (T);
elsif Present (Full_View (T)) then
T := Full_View (T);
end if;
end if;
-- Use the underlying record view when the type is an extenstion of
-- a parent type with unknown discriminants because the view contains
-- all inherited discriminants or stored constraints.
if Ekind (T) = E_Record_Type
and then Present (Underlying_Record_View (T))
then
T := Underlying_Record_View (T);
end if;
return T;
end Discriminated_View;
-----------------------------
-- Find_Discriminant_Value --
-----------------------------
function Find_Discriminant_Value
(Discr : Entity_Id;
Par_Typ : Entity_Id;
Deriv_Typ : Entity_Id;
Typ_Elmt : Elmt_Id) return Node_Or_Entity_Id
is
Discr_Pos : constant Uint := Discriminant_Number (Discr);
Typ : constant Entity_Id := Node (Typ_Elmt);
function Find_Constraint_Value
(Constr : Node_Or_Entity_Id) return Node_Or_Entity_Id;
-- Given constraint Constr, find what it denotes. This is either:
--
-- * An entity which is either a discriminant or a name
--
-- * An expression
---------------------------
-- Find_Constraint_Value --
---------------------------
function Find_Constraint_Value
(Constr : Node_Or_Entity_Id) return Node_Or_Entity_Id
is
begin
if Nkind (Constr) in N_Entity then
-- The constraint denotes a discriminant of the curren type
-- which renames the ancestor discriminant:
-- vv
-- type Typ (D1 : ...; DN : ...) is
-- new Anc (Discr => D1) with ...
-- ^^
if Ekind (Constr) = E_Discriminant then
-- The discriminant belongs to derived type Deriv_Typ. This
-- is the final value for the ancestor discriminant as the
-- derivations chain has been fully exhausted.
if Typ = Deriv_Typ then
return Constr;
-- Otherwise the discriminant may be renamed or constrained
-- at a lower level. Continue looking down the derivation
-- chain.
else
return
Find_Discriminant_Value
(Discr => Constr,
Par_Typ => Par_Typ,
Deriv_Typ => Deriv_Typ,
Typ_Elmt => Next_Elmt (Typ_Elmt));
end if;
-- Otherwise the constraint denotes a reference to some name
-- which results in a Stored discriminant:
-- vvvv
-- Name : ...;
-- type Typ (D1 : ...; DN : ...) is
-- new Anc (Discr => Name) with ...
-- ^^^^
-- Return the name as this is the proper constraint of the
-- discriminant.
else
return Constr;
end if;
-- The constraint denotes a reference to a name
elsif Is_Entity_Name (Constr) then
return Find_Constraint_Value (Entity (Constr));
-- Otherwise the current constraint is an expression which yields
-- a Stored discriminant:
-- type Typ (D1 : ...; DN : ...) is
-- new Anc (Discr => <expression>) with ...
-- ^^^^^^^^^^
-- Return the expression as this is the proper constraint of the
-- discriminant.
else
return Constr;
end if;
end Find_Constraint_Value;
-- Local variables
Constrs : constant Elist_Id := Stored_Constraint (Typ);
Constr_Elmt : Elmt_Id;
Pos : Uint;
Typ_Discr : Entity_Id;
-- Start of processing for Find_Discriminant_Value
begin
-- The algorithm for finding the value of a discriminant works as
-- follows. First, it recreates the derivation chain from Par_Typ
-- to Deriv_Typ as a list:
-- Par_Typ (shown for completeness)
-- v
-- Ancestor_N <-- head of chain
-- v
-- Ancestor_1
-- v
-- Deriv_Typ <-- tail of chain
-- The algorithm then traces the fate of a parent discriminant down
-- the derivation chain. At each derivation level, the discriminant
-- may be either inherited or constrained.
-- 1) Discriminant is inherited: there are two cases, depending on
-- which type is inheriting.
-- 1.1) Deriv_Typ is inheriting:
-- type Ancestor (D_1 : ...) is tagged ...
-- type Deriv_Typ is new Ancestor ...
-- In this case the inherited discriminant is the final value of
-- the parent discriminant because the end of the derivation chain
-- has been reached.
-- 1.2) Some other type is inheriting:
-- type Ancestor_1 (D_1 : ...) is tagged ...
-- type Ancestor_2 is new Ancestor_1 ...
-- In this case the algorithm continues to trace the fate of the
-- inherited discriminant down the derivation chain because it may
-- be further inherited or constrained.
-- 2) Discriminant is constrained: there are three cases, depending
-- on what the constraint is.
-- 2.1) The constraint is another discriminant (aka renaming):
-- type Ancestor_1 (D_1 : ...) is tagged ...
-- type Ancestor_2 (D_2 : ...) is new Ancestor_1 (D_1 => D_2) ...
-- In this case the constraining discriminant becomes the one to
-- track down the derivation chain. The algorithm already knows
-- that D_2 constrains D_1, therefore if the algorithm finds the
-- value of D_2, then this would also be the value for D_1.
-- 2.2) The constraint is a name (aka Stored):
-- Name : ...
-- type Ancestor_1 (D_1 : ...) is tagged ...
-- type Ancestor_2 is new Ancestor_1 (D_1 => Name) ...
-- In this case the name is the final value of D_1 because the
-- discriminant cannot be further constrained.
-- 2.3) The constraint is an expression (aka Stored):
-- type Ancestor_1 (D_1 : ...) is tagged ...
-- type Ancestor_2 is new Ancestor_1 (D_1 => 1 + 2) ...
-- Similar to 2.2, the expression is the final value of D_1
Pos := Uint_1;
-- When a derived type constrains its parent type, all constaints
-- appear in the Stored_Constraint list. Examine the list looking
-- for a positional match.
if Present (Constrs) then
Constr_Elmt := First_Elmt (Constrs);
while Present (Constr_Elmt) loop
-- The position of the current constraint matches that of the
-- ancestor discriminant.
if Pos = Discr_Pos then
return Find_Constraint_Value (Node (Constr_Elmt));
end if;
Next_Elmt (Constr_Elmt);
Pos := Pos + 1;
end loop;
-- Otherwise the derived type does not constraint its parent type in
-- which case it inherits the parent discriminants.
else
Typ_Discr := First_Discriminant (Typ);
while Present (Typ_Discr) loop
-- The position of the current discriminant matches that of the
-- ancestor discriminant.
if Pos = Discr_Pos then
return Find_Constraint_Value (Typ_Discr);
end if;
Next_Discriminant (Typ_Discr);
Pos := Pos + 1;
end loop;
end if;
-- A discriminant must always have a corresponding value. This is
-- either another discriminant, a name, or an expression. If this
-- point is reached, them most likely the derivation chain employs
-- the wrong views of types.
pragma Assert (False);
return Empty;
end Find_Discriminant_Value;
-----------------------
-- Map_Discriminants --
-----------------------
procedure Map_Discriminants
(Par_Typ : Entity_Id;
Deriv_Typ : Entity_Id)
is
Deriv_Chain : constant Elist_Id := Build_Chain (Par_Typ, Deriv_Typ);
Discr : Entity_Id;
Discr_Val : Node_Or_Entity_Id;
begin
-- Examine each discriminant of parent type Par_Typ and find a
-- suitable value for it from the point of view of derived type
-- Deriv_Typ.
if Has_Discriminants (Par_Typ) then
Discr := First_Discriminant (Par_Typ);
while Present (Discr) loop
Discr_Val :=
Find_Discriminant_Value
(Discr => Discr,
Par_Typ => Par_Typ,
Deriv_Typ => Deriv_Typ,
Typ_Elmt => First_Elmt (Deriv_Chain));
-- Create a mapping of the form:
-- parent type discriminant -> value
Type_Map.Set (Discr, Discr_Val);
Next_Discriminant (Discr);
end loop;
end if;
end Map_Discriminants;
--------------------
-- Map_Primitives --
--------------------
procedure Map_Primitives (Par_Typ : Entity_Id; Deriv_Typ : Entity_Id) is
Deriv_Prim : Entity_Id;
Par_Prim : Entity_Id;
Par_Prims : Elist_Id;
Prim_Elmt : Elmt_Id;
begin
-- Inspect the primitives of the derived type and determine whether
-- they relate to the primitives of the parent type. If there is a
-- meaningful relation, create a mapping of the form:
-- parent type primitive -> derived type primitive
if Present (Direct_Primitive_Operations (Deriv_Typ)) then
Prim_Elmt := First_Elmt (Direct_Primitive_Operations (Deriv_Typ));
while Present (Prim_Elmt) loop
Deriv_Prim := Node (Prim_Elmt);
if Is_Subprogram (Deriv_Prim)
and then Find_Dispatching_Type (Deriv_Prim) = Deriv_Typ
then
Add_Primitive (Deriv_Prim, Par_Typ);
end if;
Next_Elmt (Prim_Elmt);
end loop;
end if;
-- If the parent operation is an interface operation, the overriding
-- indicator is not present. Instead, we get from the interface
-- operation the primitive of the current type that implements it.
if Is_Interface (Par_Typ) then
Par_Prims := Collect_Primitive_Operations (Par_Typ);
if Present (Par_Prims) then
Prim_Elmt := First_Elmt (Par_Prims);
while Present (Prim_Elmt) loop
Par_Prim := Node (Prim_Elmt);
Deriv_Prim :=
Find_Primitive_Covering_Interface (Deriv_Typ, Par_Prim);
if Present (Deriv_Prim) then
Type_Map.Set (Par_Prim, Deriv_Prim);
end if;
Next_Elmt (Prim_Elmt);
end loop;
end if;
end if;
end Map_Primitives;
-- Start of processing for Map_Types
begin
-- Nothing to do if there are no types to work with
if No (Parent_Type) or else No (Derived_Type) then
return;
-- Nothing to do if the mapping already exists
elsif Type_Map.Get (Parent_Type) = Derived_Type then
return;
-- Nothing to do if both types are not tagged. Note that untagged types
-- do not have primitive operations and their discriminants are already
-- handled by gigi.
elsif not Is_Tagged_Type (Parent_Type)
or else not Is_Tagged_Type (Derived_Type)
then
return;
end if;
-- Create a mapping of the form
-- parent type -> derived type
-- to prevent any subsequent attempts to produce the same relations
Type_Map.Set (Parent_Type, Derived_Type);
-- Create mappings of the form
-- parent type discriminant -> derived type discriminant
-- <or>
-- parent type discriminant -> constraint
-- Note that mapping of discriminants breaks privacy because it needs to
-- work with those views which contains the discriminants and any stored
-- constraints.
Map_Discriminants
(Par_Typ => Discriminated_View (Parent_Type),
Deriv_Typ => Discriminated_View (Derived_Type));
-- Create mappings of the form
-- parent type primitive -> derived type primitive
Map_Primitives
(Par_Typ => Parent_Type,
Deriv_Typ => Derived_Type);
end Map_Types;
----------------------------
-- Matching_Standard_Type --
----------------------------
function Matching_Standard_Type (Typ : Entity_Id) return Entity_Id is
pragma Assert (Is_Scalar_Type (Typ));
Siz : constant Uint := Esize (Typ);
begin
-- Floating-point cases
if Is_Floating_Point_Type (Typ) then
if Siz <= Esize (Standard_Short_Float) then
return Standard_Short_Float;
elsif Siz <= Esize (Standard_Float) then
return Standard_Float;
elsif Siz <= Esize (Standard_Long_Float) then
return Standard_Long_Float;
elsif Siz <= Esize (Standard_Long_Long_Float) then
return Standard_Long_Long_Float;
else
raise Program_Error;
end if;
-- Integer cases (includes fixed-point types)
-- Unsigned integer cases (includes normal enumeration types)
else
return Small_Integer_Type_For (Siz, Is_Unsigned_Type (Typ));
end if;
end Matching_Standard_Type;
-----------------------------
-- May_Generate_Large_Temp --
-----------------------------
-- At the current time, the only types that we return False for (i.e. where
-- we decide we know they cannot generate large temps) are ones where we
-- know the size is 256 bits or less at compile time, and we are still not
-- doing a thorough job on arrays and records.
function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is
begin
if not Size_Known_At_Compile_Time (Typ) then
return False;
end if;
if Known_Esize (Typ) and then Esize (Typ) <= 256 then
return False;
end if;
if Is_Array_Type (Typ)
and then Present (Packed_Array_Impl_Type (Typ))
then
return May_Generate_Large_Temp (Packed_Array_Impl_Type (Typ));
end if;
return True;
end May_Generate_Large_Temp;
--------------------------------------------
-- Needs_Conditional_Null_Excluding_Check --
--------------------------------------------
function Needs_Conditional_Null_Excluding_Check
(Typ : Entity_Id) return Boolean
is
begin
return
Is_Array_Type (Typ) and then Can_Never_Be_Null (Component_Type (Typ));
end Needs_Conditional_Null_Excluding_Check;
----------------------------
-- Needs_Constant_Address --
----------------------------
function Needs_Constant_Address
(Decl : Node_Id;
Typ : Entity_Id) return Boolean
is
begin
-- If we have no initialization of any kind, then we don't need to place
-- any restrictions on the address clause, because the object will be
-- elaborated after the address clause is evaluated. This happens if the
-- declaration has no initial expression, or the type has no implicit
-- initialization, or the object is imported.
-- The same holds for all initialized scalar types and all access types.
-- Packed bit array types of size up to the maximum integer size are
-- represented using a modular type with an initialization (to zero) and
-- can be processed like other initialized scalar types.
-- If the type is controlled, code to attach the object to a
-- finalization chain is generated at the point of declaration, and
-- therefore the elaboration of the object cannot be delayed: the
-- address expression must be a constant.
if No (Expression (Decl))
and then not Needs_Finalization (Typ)
and then
(not Has_Non_Null_Base_Init_Proc (Typ)
or else Is_Imported (Defining_Identifier (Decl)))
then
return False;
elsif (Present (Expression (Decl)) and then Is_Scalar_Type (Typ))
or else Is_Access_Type (Typ)
or else
(Is_Bit_Packed_Array (Typ)
and then Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ)))
then
return False;
else
-- Otherwise, we require the address clause to be constant because
-- the call to the initialization procedure (or the attach code) has
-- to happen at the point of the declaration.
-- Actually the IP call has been moved to the freeze actions anyway,
-- so maybe we can relax this restriction???
return True;
end if;
end Needs_Constant_Address;
----------------------------
-- New_Class_Wide_Subtype --
----------------------------
function New_Class_Wide_Subtype
(CW_Typ : Entity_Id;
N : Node_Id) return Entity_Id
is
Res : constant Entity_Id := Create_Itype (E_Void, N);
-- Capture relevant attributes of the class-wide subtype which must be
-- restored after the copy.
Res_Chars : constant Name_Id := Chars (Res);
Res_Is_CGE : constant Boolean := Is_Checked_Ghost_Entity (Res);
Res_Is_IGE : constant Boolean := Is_Ignored_Ghost_Entity (Res);
Res_Is_IGN : constant Boolean := Is_Ignored_Ghost_Node (Res);
Res_Scope : constant Entity_Id := Scope (Res);
begin
Copy_Node (CW_Typ, Res);
-- Restore the relevant attributes of the class-wide subtype
Set_Chars (Res, Res_Chars);
Set_Is_Checked_Ghost_Entity (Res, Res_Is_CGE);
Set_Is_Ignored_Ghost_Entity (Res, Res_Is_IGE);
Set_Is_Ignored_Ghost_Node (Res, Res_Is_IGN);
Set_Scope (Res, Res_Scope);
-- Decorate the class-wide subtype
Set_Associated_Node_For_Itype (Res, N);
Set_Comes_From_Source (Res, False);
Mutate_Ekind (Res, E_Class_Wide_Subtype);
Set_Etype (Res, Base_Type (CW_Typ));
Set_Freeze_Node (Res, Empty);
Set_Is_Frozen (Res, False);
Set_Is_Itype (Res);
Set_Is_Public (Res, False);
Set_Next_Entity (Res, Empty);
Set_Prev_Entity (Res, Empty);
Set_Sloc (Res, Sloc (N));
Set_Public_Status (Res);
return Res;
end New_Class_Wide_Subtype;
-----------------------------------
-- OK_To_Do_Constant_Replacement --
-----------------------------------
function OK_To_Do_Constant_Replacement (E : Entity_Id) return Boolean is
ES : constant Entity_Id := Scope (E);
CS : Entity_Id;
begin
-- Do not replace statically allocated objects, because they may be
-- modified outside the current scope.
if Is_Statically_Allocated (E) then
return False;
-- Do not replace aliased or volatile objects, since we don't know what
-- else might change the value.
elsif Is_Aliased (E) or else Treat_As_Volatile (E) then
return False;
-- Debug flag -gnatdM disconnects this optimization
elsif Debug_Flag_MM then
return False;
-- Otherwise check scopes
else
CS := Current_Scope;
loop
-- If we are in right scope, replacement is safe
if CS = ES then
return True;
-- Packages do not affect the determination of safety
elsif Ekind (CS) = E_Package then
exit when CS = Standard_Standard;
CS := Scope (CS);
-- Blocks do not affect the determination of safety
elsif Ekind (CS) = E_Block then
CS := Scope (CS);
-- Loops do not affect the determination of safety. Note that we
-- kill all current values on entry to a loop, so we are just
-- talking about processing within a loop here.
elsif Ekind (CS) = E_Loop then
CS := Scope (CS);
-- Otherwise, the reference is dubious, and we cannot be sure that
-- it is safe to do the replacement.
else
exit;
end if;
end loop;
return False;
end if;
end OK_To_Do_Constant_Replacement;
------------------------------------
-- Possible_Bit_Aligned_Component --
------------------------------------
function Possible_Bit_Aligned_Component (N : Node_Id) return Boolean is
begin
-- Do not process an unanalyzed node because it is not yet decorated and
-- most checks performed below will fail.
if not Analyzed (N) then
return False;
end if;
-- There are never alignment issues in CodePeer mode
if CodePeer_Mode then
return False;
end if;
case Nkind (N) is
-- Case of indexed component
when N_Indexed_Component =>
declare
P : constant Node_Id := Prefix (N);
Ptyp : constant Entity_Id := Etype (P);
begin
-- If we know the component size and it is not larger than the
-- maximum integer size, then we are OK. The back end does the
-- assignment of small misaligned objects correctly.
if Known_Static_Component_Size (Ptyp)
and then Component_Size (Ptyp) <= System_Max_Integer_Size
then
return False;
-- Otherwise, we need to test the prefix, to see if we are
-- indexing from a possibly unaligned component.
else
return Possible_Bit_Aligned_Component (P);
end if;
end;
-- Case of selected component
when N_Selected_Component =>
declare
P : constant Node_Id := Prefix (N);
Comp : constant Entity_Id := Entity (Selector_Name (N));
begin
-- This is the crucial test: if the component itself causes
-- trouble, then we can stop and return True.
if Component_May_Be_Bit_Aligned (Comp) then
return True;
-- Otherwise, we need to test the prefix, to see if we are
-- selecting from a possibly unaligned component.
else
return Possible_Bit_Aligned_Component (P);
end if;
end;
-- For a slice, test the prefix, if that is possibly misaligned,
-- then for sure the slice is.
when N_Slice =>
return Possible_Bit_Aligned_Component (Prefix (N));
-- For an unchecked conversion, check whether the expression may
-- be bit aligned.
when N_Unchecked_Type_Conversion =>
return Possible_Bit_Aligned_Component (Expression (N));
-- If we have none of the above, it means that we have fallen off the
-- top testing prefixes recursively, and we now have a stand alone
-- object, where we don't have a problem, unless this is a renaming,
-- in which case we need to look into the renamed object.
when others =>
if Is_Entity_Name (N)
and then Present (Renamed_Object (Entity (N)))
then
return
Possible_Bit_Aligned_Component (Renamed_Object (Entity (N)));
else
return False;
end if;
end case;
end Possible_Bit_Aligned_Component;
-----------------------------------------------
-- Process_Statements_For_Controlled_Objects --
-----------------------------------------------
procedure Process_Statements_For_Controlled_Objects (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
function Are_Wrapped (L : List_Id) return Boolean;
-- Determine whether list L contains only one statement which is a block
function Wrap_Statements_In_Block
(L : List_Id;
Scop : Entity_Id := Current_Scope) return Node_Id;
-- Given a list of statements L, wrap it in a block statement and return
-- the generated node. Scop is either the current scope or the scope of
-- the context (if applicable).
-----------------
-- Are_Wrapped --
-----------------
function Are_Wrapped (L : List_Id) return Boolean is
Stmt : constant Node_Id := First (L);
begin
return
Present (Stmt)
and then No (Next (Stmt))
and then Nkind (Stmt) = N_Block_Statement;
end Are_Wrapped;
------------------------------
-- Wrap_Statements_In_Block --
------------------------------
function Wrap_Statements_In_Block
(L : List_Id;
Scop : Entity_Id := Current_Scope) return Node_Id
is
Block_Id : Entity_Id;
Block_Nod : Node_Id;
Iter_Loop : Entity_Id;
begin
Block_Nod :=
Make_Block_Statement (Loc,
Declarations => No_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => L));
-- Create a label for the block in case the block needs to manage the
-- secondary stack. A label allows for flag Uses_Sec_Stack to be set.
Add_Block_Identifier (Block_Nod, Block_Id);
-- When wrapping the statements of an iterator loop, check whether
-- the loop requires secondary stack management and if so, propagate
-- the appropriate flags to the block. This ensures that the cursor
-- is properly cleaned up at each iteration of the loop.
Iter_Loop := Find_Enclosing_Iterator_Loop (Scop);
if Present (Iter_Loop) then
Set_Uses_Sec_Stack (Block_Id, Uses_Sec_Stack (Iter_Loop));
-- Secondary stack reclamation is suppressed when the associated
-- iterator loop contains a return statement which uses the stack.
Set_Sec_Stack_Needed_For_Return
(Block_Id, Sec_Stack_Needed_For_Return (Iter_Loop));
end if;
return Block_Nod;
end Wrap_Statements_In_Block;
-- Local variables
Block : Node_Id;
-- Start of processing for Process_Statements_For_Controlled_Objects
begin
-- Whenever a non-handled statement list is wrapped in a block, the
-- block must be explicitly analyzed to redecorate all entities in the
-- list and ensure that a finalizer is properly built.
case Nkind (N) is
when N_Conditional_Entry_Call
| N_Elsif_Part
| N_If_Statement
| N_Selective_Accept
=>
-- Check the "then statements" for elsif parts and if statements
if Nkind (N) in N_Elsif_Part | N_If_Statement
and then not Is_Empty_List (Then_Statements (N))
and then not Are_Wrapped (Then_Statements (N))
and then Requires_Cleanup_Actions
(L => Then_Statements (N),
Lib_Level => False,
Nested_Constructs => False)
then
Block := Wrap_Statements_In_Block (Then_Statements (N));
Set_Then_Statements (N, New_List (Block));
Analyze (Block);
end if;
-- Check the "else statements" for conditional entry calls, if
-- statements and selective accepts.
if Nkind (N) in
N_Conditional_Entry_Call | N_If_Statement | N_Selective_Accept
and then not Is_Empty_List (Else_Statements (N))
and then not Are_Wrapped (Else_Statements (N))
and then Requires_Cleanup_Actions
(L => Else_Statements (N),
Lib_Level => False,
Nested_Constructs => False)
then
Block := Wrap_Statements_In_Block (Else_Statements (N));
Set_Else_Statements (N, New_List (Block));
Analyze (Block);
end if;
when N_Abortable_Part
| N_Accept_Alternative
| N_Case_Statement_Alternative
| N_Delay_Alternative
| N_Entry_Call_Alternative
| N_Exception_Handler
| N_Loop_Statement
| N_Triggering_Alternative
=>
if not Is_Empty_List (Statements (N))
and then not Are_Wrapped (Statements (N))
and then Requires_Cleanup_Actions
(L => Statements (N),
Lib_Level => False,
Nested_Constructs => False)
then
if Nkind (N) = N_Loop_Statement
and then Present (Identifier (N))
then
Block :=
Wrap_Statements_In_Block
(L => Statements (N),
Scop => Entity (Identifier (N)));
else
Block := Wrap_Statements_In_Block (Statements (N));
end if;
Set_Statements (N, New_List (Block));
Analyze (Block);
end if;
-- Could be e.g. a loop that was transformed into a block or null
-- statement. Do nothing for terminate alternatives.
when N_Block_Statement
| N_Null_Statement
| N_Terminate_Alternative
=>
null;
when others =>
raise Program_Error;
end case;
end Process_Statements_For_Controlled_Objects;
------------------
-- Power_Of_Two --
------------------
function Power_Of_Two (N : Node_Id) return Nat is
Typ : constant Entity_Id := Etype (N);
pragma Assert (Is_Integer_Type (Typ));
Siz : constant Nat := UI_To_Int (Esize (Typ));
Val : Uint;
begin
if not Compile_Time_Known_Value (N) then
return 0;
else
Val := Expr_Value (N);
for J in 1 .. Siz - 1 loop
if Val = Uint_2 ** J then
return J;
end if;
end loop;
return 0;
end if;
end Power_Of_Two;
----------------------
-- Remove_Init_Call --
----------------------
function Remove_Init_Call
(Var : Entity_Id;
Rep_Clause : Node_Id) return Node_Id
is
Par : constant Node_Id := Parent (Var);
Typ : constant Entity_Id := Etype (Var);
Init_Proc : Entity_Id;
-- Initialization procedure for Typ
function Find_Init_Call_In_List (From : Node_Id) return Node_Id;
-- Look for init call for Var starting at From and scanning the
-- enclosing list until Rep_Clause or the end of the list is reached.
----------------------------
-- Find_Init_Call_In_List --
----------------------------
function Find_Init_Call_In_List (From : Node_Id) return Node_Id is
Init_Call : Node_Id;
begin
Init_Call := From;
while Present (Init_Call) and then Init_Call /= Rep_Clause loop
if Nkind (Init_Call) = N_Procedure_Call_Statement
and then Is_Entity_Name (Name (Init_Call))
and then Entity (Name (Init_Call)) = Init_Proc
then
return Init_Call;
end if;
Next (Init_Call);
end loop;
return Empty;
end Find_Init_Call_In_List;
Init_Call : Node_Id;
-- Start of processing for Remove_Init_Call
begin
if Present (Initialization_Statements (Var)) then
Init_Call := Initialization_Statements (Var);
Set_Initialization_Statements (Var, Empty);
elsif not Has_Non_Null_Base_Init_Proc (Typ) then
-- No init proc for the type, so obviously no call to be found
return Empty;
else
-- We might be able to handle other cases below by just properly
-- setting Initialization_Statements at the point where the init proc
-- call is generated???
Init_Proc := Base_Init_Proc (Typ);
-- First scan the list containing the declaration of Var
Init_Call := Find_Init_Call_In_List (From => Next (Par));
-- If not found, also look on Var's freeze actions list, if any,
-- since the init call may have been moved there (case of an address
-- clause applying to Var).
if No (Init_Call) and then Present (Freeze_Node (Var)) then
Init_Call :=
Find_Init_Call_In_List (First (Actions (Freeze_Node (Var))));
end if;
-- If the initialization call has actuals that use the secondary
-- stack, the call may have been wrapped into a temporary block, in
-- which case the block itself has to be removed.
if No (Init_Call) and then Nkind (Next (Par)) = N_Block_Statement then
declare
Blk : constant Node_Id := Next (Par);
begin
if Present
(Find_Init_Call_In_List
(First (Statements (Handled_Statement_Sequence (Blk)))))
then
Init_Call := Blk;
end if;
end;
end if;
end if;
if Present (Init_Call) then
-- If restrictions have forbidden Aborts, the initialization call
-- for objects that require deep initialization has not been wrapped
-- into the following block (see Exp_Ch3, Default_Initialize_Object)
-- so if present remove it as well, and include the IP call in it,
-- in the rare case the caller may need to simply displace the
-- initialization, as is done for a later address specification.
if Nkind (Next (Init_Call)) = N_Block_Statement
and then Is_Initialization_Block (Next (Init_Call))
then
declare
IP_Call : constant Node_Id := Init_Call;
begin
Init_Call := Next (IP_Call);
Remove (IP_Call);
Prepend (IP_Call,
Statements (Handled_Statement_Sequence (Init_Call)));
end;
end if;
Remove (Init_Call);
end if;
return Init_Call;
end Remove_Init_Call;
-------------------------
-- Remove_Side_Effects --
-------------------------
procedure Remove_Side_Effects
(Exp : Node_Id;
Name_Req : Boolean := False;
Renaming_Req : Boolean := False;
Variable_Ref : Boolean := False;
Related_Id : Entity_Id := Empty;
Is_Low_Bound : Boolean := False;
Is_High_Bound : Boolean := False;
Discr_Number : Int := 0;
Check_Side_Effects : Boolean := True)
is
function Build_Temporary
(Loc : Source_Ptr;
Id : Character;
Related_Nod : Node_Id := Empty) return Entity_Id;
-- Create an external symbol of the form xxx_FIRST/_LAST if Related_Nod
-- is present (xxx is taken from the Chars field of Related_Nod),
-- otherwise it generates an internal temporary. The created temporary
-- entity is marked as internal.
function Possible_Side_Effect_In_SPARK (Exp : Node_Id) return Boolean;
-- Computes whether a side effect is possible in SPARK, which should
-- be handled by removing it from the expression for GNATprove. Note
-- that other side effects related to volatile variables are handled
-- separately.
---------------------
-- Build_Temporary --
---------------------
function Build_Temporary
(Loc : Source_Ptr;
Id : Character;
Related_Nod : Node_Id := Empty) return Entity_Id
is
Temp_Id : Entity_Id;
Temp_Nam : Name_Id;
Should_Set_Related_Expression : Boolean := False;
begin
-- The context requires an external symbol : expression is
-- the bound of an array, or a discriminant value. We create
-- a unique string using the related entity and an appropriate
-- suffix, rather than a numeric serial number (used for internal
-- entities) that may vary depending on compilation options, in
-- particular on the Assertions_Enabled mode. This avoids spurious
-- link errors.
if Present (Related_Id) then
if Is_Low_Bound then
Temp_Nam := New_External_Name (Chars (Related_Id), "_FIRST");
elsif Is_High_Bound then
Temp_Nam := New_External_Name (Chars (Related_Id), "_LAST");
else
pragma Assert (Discr_Number > 0);
-- We don't have any intelligible way of printing T_DISCR in
-- CodePeer. Thus, set a related expression in this case.
Should_Set_Related_Expression := True;
-- Use fully qualified name to avoid ambiguities.
Temp_Nam :=
New_External_Name
(Get_Qualified_Name (Related_Id), "_DISCR", Discr_Number);
end if;
Temp_Id := Make_Defining_Identifier (Loc, Temp_Nam);
if Should_Set_Related_Expression then
Set_Related_Expression (Temp_Id, Related_Nod);
end if;
-- Otherwise generate an internal temporary
else
Temp_Id := Make_Temporary (Loc, Id, Related_Nod);
end if;
Set_Is_Internal (Temp_Id);
return Temp_Id;
end Build_Temporary;
-----------------------------------
-- Possible_Side_Effect_In_SPARK --
-----------------------------------
function Possible_Side_Effect_In_SPARK (Exp : Node_Id) return Boolean is
begin
-- Side-effect removal in SPARK should only occur when not inside a
-- generic and not doing a preanalysis, inside an object renaming or
-- a type declaration or a for-loop iteration scheme.
return not Inside_A_Generic
and then Full_Analysis
and then Nkind (Enclosing_Declaration (Exp)) in
N_Component_Declaration
| N_Full_Type_Declaration
| N_Iterator_Specification
| N_Loop_Parameter_Specification
| N_Object_Renaming_Declaration
| N_Subtype_Declaration;
end Possible_Side_Effect_In_SPARK;
-- Local variables
Loc : constant Source_Ptr := Sloc (Exp);
Exp_Type : constant Entity_Id := Etype (Exp);
Svg_Suppress : constant Suppress_Record := Scope_Suppress;
Def_Id : Entity_Id;
E : Node_Id;
New_Exp : Node_Id;
Ptr_Typ_Decl : Node_Id;
Ref_Type : Entity_Id;
Res : Node_Id;
-- Start of processing for Remove_Side_Effects
begin
-- Handle cases in which there is nothing to do. In GNATprove mode,
-- removal of side effects is useful for the light expansion of
-- renamings.
if not Expander_Active
and then not
(GNATprove_Mode and then Possible_Side_Effect_In_SPARK (Exp))
then
return;
-- Cannot generate temporaries if the invocation to remove side effects
-- was issued too early and the type of the expression is not resolved
-- (this happens because routines Duplicate_Subexpr_XX implicitly invoke
-- Remove_Side_Effects).
elsif No (Exp_Type)
or else Ekind (Exp_Type) = E_Access_Attribute_Type
then
return;
-- Nothing to do if prior expansion determined that a function call does
-- not require side effect removal.
elsif Nkind (Exp) = N_Function_Call
and then No_Side_Effect_Removal (Exp)
then
return;
-- No action needed for side-effect free expressions
elsif Check_Side_Effects
and then Side_Effect_Free (Exp, Name_Req, Variable_Ref)
then
return;
-- Generating C code we cannot remove side effect of function returning
-- class-wide types since there is no secondary stack (required to use
-- 'reference).
elsif Modify_Tree_For_C
and then Nkind (Exp) = N_Function_Call
and then Is_Class_Wide_Type (Etype (Exp))
then
return;
end if;
-- The remaining processing is done with all checks suppressed
-- Note: from now on, don't use return statements, instead do a goto
-- Leave, to ensure that we properly restore Scope_Suppress.Suppress.
Scope_Suppress.Suppress := (others => True);
-- If this is a side-effect free attribute reference whose expressions
-- are also side-effect free and whose prefix is not a name, remove the
-- side effects of the prefix. A copy of the prefix is required in this
-- case and it is better not to make an additional one for the attribute
-- itself, because the return type of many of them is universal integer,
-- which is a very large type for a temporary.
-- The prefix of an attribute reference Reduce may be syntactically an
-- aggregate, but will be expanded into a loop, so no need to remove
-- side-effects.
if Nkind (Exp) = N_Attribute_Reference
and then Side_Effect_Free_Attribute (Attribute_Name (Exp))
and then Side_Effect_Free (Expressions (Exp), Name_Req, Variable_Ref)
and then (Attribute_Name (Exp) /= Name_Reduce
or else Nkind (Prefix (Exp)) /= N_Aggregate)
and then not Is_Name_Reference (Prefix (Exp))
then
Remove_Side_Effects (Prefix (Exp), Name_Req, Variable_Ref);
goto Leave;
-- If this is an elementary or a small not-by-reference record type, and
-- we need to capture the value, just make a constant; this is cheap and
-- objects of both kinds of types can be bit aligned, so it might not be
-- possible to generate a reference to them. Likewise if this is not a
-- name reference, except for a type conversion, because we would enter
-- an infinite recursion with Checks.Apply_Predicate_Check if the target
-- type has predicates (and type conversions need a specific treatment
-- anyway, see below). Also do it if we have a volatile reference and
-- Name_Req is not set (see comments for Side_Effect_Free).
elsif (Is_Elementary_Type (Exp_Type)
or else (Is_Record_Type (Exp_Type)
and then Known_Static_RM_Size (Exp_Type)
and then RM_Size (Exp_Type) <= System_Max_Integer_Size
and then not Has_Discriminants (Exp_Type)
and then not Is_By_Reference_Type (Exp_Type)))
and then (Variable_Ref
or else (not Is_Name_Reference (Exp)
and then Nkind (Exp) /= N_Type_Conversion)
or else (not Name_Req
and then Is_Volatile_Reference (Exp)))
then
Def_Id := Build_Temporary (Loc, 'R', Exp);
Set_Etype (Def_Id, Exp_Type);
Res := New_Occurrence_Of (Def_Id, Loc);
-- If the expression is a packed reference, it must be reanalyzed and
-- expanded, depending on context. This is the case for actuals where
-- a constraint check may capture the actual before expansion of the
-- call is complete.
if Nkind (Exp) = N_Indexed_Component
and then Is_Packed (Etype (Prefix (Exp)))
then
Set_Analyzed (Exp, False);
Set_Analyzed (Prefix (Exp), False);
end if;
-- Generate:
-- Rnn : Exp_Type renames Expr;
-- In GNATprove mode, we prefer to use renamings for intermediate
-- variables to definition of constants, due to the implicit move
-- operation that such a constant definition causes as part of the
-- support in GNATprove for ownership pointers. Hence, we generate
-- a renaming for a reference to an object of a nonscalar type.
if Renaming_Req
or else (GNATprove_Mode
and then Is_Object_Reference (Exp)
and then not Is_Scalar_Type (Exp_Type))
then
E :=
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Mark => New_Occurrence_Of (Exp_Type, Loc),
Name => Relocate_Node (Exp));
-- Generate:
-- Rnn : constant Exp_Type := Expr;
else
E :=
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Object_Definition => New_Occurrence_Of (Exp_Type, Loc),
Constant_Present => True,
Expression => Relocate_Node (Exp));
Set_Assignment_OK (E);
end if;
Insert_Action (Exp, E);
-- If the expression has the form v.all then we can just capture the
-- pointer, and then do an explicit dereference on the result, but
-- this is not right if this is a volatile reference.
elsif Nkind (Exp) = N_Explicit_Dereference
and then not Is_Volatile_Reference (Exp)
then
Def_Id := Build_Temporary (Loc, 'R', Exp);
Res :=
Make_Explicit_Dereference (Loc, New_Occurrence_Of (Def_Id, Loc));
Insert_Action (Exp,
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Object_Definition =>
New_Occurrence_Of (Etype (Prefix (Exp)), Loc),
Constant_Present => True,
Expression => Relocate_Node (Prefix (Exp))));
-- Similar processing for an unchecked conversion of an expression of
-- the form v.all, where we want the same kind of treatment.
elsif Nkind (Exp) = N_Unchecked_Type_Conversion
and then Nkind (Expression (Exp)) = N_Explicit_Dereference
then
Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
goto Leave;
-- If this is a type conversion, leave the type conversion and remove
-- side effects in the expression, unless it is of universal integer,
-- which is a very large type for a temporary. This is important in
-- several circumstances: for change of representations and also when
-- this is a view conversion to a smaller object, where gigi can end
-- up creating its own temporary of the wrong size.
elsif Nkind (Exp) = N_Type_Conversion
and then Etype (Expression (Exp)) /= Universal_Integer
then
Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
-- Generating C code the type conversion of an access to constrained
-- array type into an access to unconstrained array type involves
-- initializing a fat pointer and the expression must be free of
-- side effects to safely compute its bounds.
if Modify_Tree_For_C
and then Is_Access_Type (Etype (Exp))
and then Is_Array_Type (Designated_Type (Etype (Exp)))
and then not Is_Constrained (Designated_Type (Etype (Exp)))
then
Def_Id := Build_Temporary (Loc, 'R', Exp);
Set_Etype (Def_Id, Exp_Type);
Res := New_Occurrence_Of (Def_Id, Loc);
Insert_Action (Exp,
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Object_Definition => New_Occurrence_Of (Exp_Type, Loc),
Constant_Present => True,
Expression => Relocate_Node (Exp)));
else
goto Leave;
end if;
-- If this is an unchecked conversion that Gigi can't handle, make
-- a copy or a use a renaming to capture the value.
elsif Nkind (Exp) = N_Unchecked_Type_Conversion
and then not Safe_Unchecked_Type_Conversion (Exp)
then
if CW_Or_Has_Controlled_Part (Exp_Type) then
-- Use a renaming to capture the expression, rather than create
-- a controlled temporary.
Def_Id := Build_Temporary (Loc, 'R', Exp);
Res := New_Occurrence_Of (Def_Id, Loc);
Insert_Action (Exp,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Mark => New_Occurrence_Of (Exp_Type, Loc),
Name => Relocate_Node (Exp)));
else
Def_Id := Build_Temporary (Loc, 'R', Exp);
Set_Etype (Def_Id, Exp_Type);
Res := New_Occurrence_Of (Def_Id, Loc);
E :=
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Object_Definition => New_Occurrence_Of (Exp_Type, Loc),
Constant_Present => not Is_Variable (Exp),
Expression => Relocate_Node (Exp));
Set_Assignment_OK (E);
Insert_Action (Exp, E);
end if;
-- If this is a packed array component or a selected component with a
-- nonstandard representation, we cannot generate a reference because
-- the component may be unaligned, so we must use a renaming and this
-- renaming is handled by the front end, as the back end may balk at
-- the nonstandard representation (see Evaluation_Required in Exp_Ch8).
elsif Nkind (Exp) in N_Indexed_Component | N_Selected_Component
and then Has_Non_Standard_Rep (Etype (Prefix (Exp)))
then
Def_Id := Build_Temporary (Loc, 'R', Exp);
Res := New_Occurrence_Of (Def_Id, Loc);
Insert_Action (Exp,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Mark => New_Occurrence_Of (Exp_Type, Loc),
Name => Relocate_Node (Exp)));
-- For an expression that denotes a name, we can use a renaming scheme.
-- This is needed for correctness in the case of a volatile object of
-- a nonvolatile type because the Make_Reference call of the "default"
-- approach would generate an illegal access value (an access value
-- cannot designate such an object - see Analyze_Reference).
elsif Is_Name_Reference (Exp)
-- We skip using this scheme if we have an object of a volatile
-- type and we do not have Name_Req set true (see comments for
-- Side_Effect_Free).
and then (Name_Req or else not Treat_As_Volatile (Exp_Type))
then
Def_Id := Build_Temporary (Loc, 'R', Exp);
Res := New_Occurrence_Of (Def_Id, Loc);
Insert_Action (Exp,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Mark => New_Occurrence_Of (Exp_Type, Loc),
Name => Relocate_Node (Exp)));
-- Avoid generating a variable-sized temporary, by generating the
-- reference just for the function call. The transformation could be
-- refined to apply only when the array component is constrained by a
-- discriminant???
elsif Nkind (Exp) = N_Selected_Component
and then Nkind (Prefix (Exp)) = N_Function_Call
and then Is_Array_Type (Exp_Type)
then
Remove_Side_Effects (Prefix (Exp), Name_Req, Variable_Ref);
goto Leave;
-- Otherwise we generate a reference to the expression
else
-- When generating C code we cannot consider side effect free object
-- declarations that have discriminants and are initialized by means
-- of a function call since on this target there is no secondary
-- stack to store the return value and the expander may generate an
-- extra call to the function to compute the discriminant value. In
-- addition, for targets that have secondary stack, the expansion of
-- functions with side effects involves the generation of an access
-- type to capture the return value stored in the secondary stack;
-- by contrast when generating C code such expansion generates an
-- internal object declaration (no access type involved) which must
-- be identified here to avoid entering into a never-ending loop
-- generating internal object declarations.
if Modify_Tree_For_C
and then Nkind (Parent (Exp)) = N_Object_Declaration
and then
(Nkind (Exp) /= N_Function_Call
or else not Has_Discriminants (Exp_Type)
or else Is_Internal_Name
(Chars (Defining_Identifier (Parent (Exp)))))
then
goto Leave;
end if;
-- Special processing for function calls that return a limited type.
-- We need to build a declaration that will enable build-in-place
-- expansion of the call. This is not done if the context is already
-- an object declaration, to prevent infinite recursion.
-- This is relevant only in Ada 2005 mode. In Ada 95 programs we have
-- to accommodate functions returning limited objects by reference.
if Ada_Version >= Ada_2005
and then Nkind (Exp) = N_Function_Call
and then Is_Limited_View (Etype (Exp))
and then Nkind (Parent (Exp)) /= N_Object_Declaration
then
declare
Obj : constant Entity_Id := Make_Temporary (Loc, 'F', Exp);
Decl : Node_Id;
begin
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Obj,
Object_Definition => New_Occurrence_Of (Exp_Type, Loc),
Expression => Relocate_Node (Exp));
Insert_Action (Exp, Decl);
Set_Etype (Obj, Exp_Type);
Rewrite (Exp, New_Occurrence_Of (Obj, Loc));
goto Leave;
end;
end if;
Def_Id := Build_Temporary (Loc, 'R', Exp);
-- The regular expansion of functions with side effects involves the
-- generation of an access type to capture the return value found on
-- the secondary stack. Since SPARK (and why) cannot process access
-- types, use a different approach which ignores the secondary stack
-- and "copies" the returned object.
-- When generating C code, no need for a 'reference since the
-- secondary stack is not supported.
if GNATprove_Mode or Modify_Tree_For_C then
Res := New_Occurrence_Of (Def_Id, Loc);
Ref_Type := Exp_Type;
-- Regular expansion utilizing an access type and 'reference
else
Res :=
Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (Def_Id, Loc));
-- Generate:
-- type Ann is access all <Exp_Type>;
Ref_Type := Make_Temporary (Loc, 'A');
Ptr_Typ_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Ref_Type,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present => True,
Subtype_Indication =>
New_Occurrence_Of (Exp_Type, Loc)));
Insert_Action (Exp, Ptr_Typ_Decl);
end if;
E := Exp;
if Nkind (E) = N_Explicit_Dereference then
New_Exp := Relocate_Node (Prefix (E));
else
E := Relocate_Node (E);
-- Do not generate a 'reference in SPARK mode or C generation
-- since the access type is not created in the first place.
if GNATprove_Mode or Modify_Tree_For_C then
New_Exp := E;
-- Otherwise generate reference, marking the value as non-null
-- since we know it cannot be null and we don't want a check.
else
New_Exp := Make_Reference (Loc, E);
Set_Is_Known_Non_Null (Def_Id);
end if;
end if;
if Is_Delayed_Aggregate (E) then
-- The expansion of nested aggregates is delayed until the
-- enclosing aggregate is expanded. As aggregates are often
-- qualified, the predicate applies to qualified expressions as
-- well, indicating that the enclosing aggregate has not been
-- expanded yet. At this point the aggregate is part of a
-- stand-alone declaration, and must be fully expanded.
if Nkind (E) = N_Qualified_Expression then
Set_Expansion_Delayed (Expression (E), False);
Set_Analyzed (Expression (E), False);
else
Set_Expansion_Delayed (E, False);
end if;
Set_Analyzed (E, False);
end if;
-- Generating C code of object declarations that have discriminants
-- and are initialized by means of a function call we propagate the
-- discriminants of the parent type to the internally built object.
-- This is needed to avoid generating an extra call to the called
-- function.
-- For example, if we generate here the following declaration, it
-- will be expanded later adding an extra call to evaluate the value
-- of the discriminant (needed to compute the size of the object).
--
-- type Rec (D : Integer) is ...
-- Obj : constant Rec := SomeFunc;
if Modify_Tree_For_C
and then Nkind (Parent (Exp)) = N_Object_Declaration
and then Has_Discriminants (Exp_Type)
and then Nkind (Exp) = N_Function_Call
then
Insert_Action (Exp,
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Object_Definition => New_Copy_Tree
(Object_Definition (Parent (Exp))),
Constant_Present => True,
Expression => New_Exp));
else
Insert_Action (Exp,
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Object_Definition => New_Occurrence_Of (Ref_Type, Loc),
Constant_Present => True,
Expression => New_Exp));
end if;
end if;
-- Preserve the Assignment_OK flag in all copies, since at least one
-- copy may be used in a context where this flag must be set (otherwise
-- why would the flag be set in the first place).
Set_Assignment_OK (Res, Assignment_OK (Exp));
-- Preserve the Do_Range_Check flag in all copies
Set_Do_Range_Check (Res, Do_Range_Check (Exp));
-- Finally rewrite the original expression and we are done
Rewrite (Exp, Res);
Analyze_And_Resolve (Exp, Exp_Type);
<<Leave>>
Scope_Suppress := Svg_Suppress;
end Remove_Side_Effects;
------------------------
-- Replace_References --
------------------------
procedure Replace_References
(Expr : Node_Id;
Par_Typ : Entity_Id;
Deriv_Typ : Entity_Id;
Par_Obj : Entity_Id := Empty;
Deriv_Obj : Entity_Id := Empty)
is
function Is_Deriv_Obj_Ref (Ref : Node_Id) return Boolean;
-- Determine whether node Ref denotes some component of Deriv_Obj
function Replace_Ref (Ref : Node_Id) return Traverse_Result;
-- Substitute a reference to an entity with the corresponding value
-- stored in table Type_Map.
function Type_Of_Formal
(Call : Node_Id;
Actual : Node_Id) return Entity_Id;
-- Find the type of the formal parameter which corresponds to actual
-- parameter Actual in subprogram call Call.
----------------------
-- Is_Deriv_Obj_Ref --
----------------------
function Is_Deriv_Obj_Ref (Ref : Node_Id) return Boolean is
Par : constant Node_Id := Parent (Ref);
begin
-- Detect the folowing selected component form:
-- Deriv_Obj.(something)
return
Nkind (Par) = N_Selected_Component
and then Is_Entity_Name (Prefix (Par))
and then Entity (Prefix (Par)) = Deriv_Obj;
end Is_Deriv_Obj_Ref;
-----------------
-- Replace_Ref --
-----------------
function Replace_Ref (Ref : Node_Id) return Traverse_Result is
procedure Remove_Controlling_Arguments (From_Arg : Node_Id);
-- Reset the Controlling_Argument of all function calls that
-- encapsulate node From_Arg.
----------------------------------
-- Remove_Controlling_Arguments --
----------------------------------
procedure Remove_Controlling_Arguments (From_Arg : Node_Id) is
Par : Node_Id;
begin
Par := From_Arg;
while Present (Par) loop
if Nkind (Par) = N_Function_Call
and then Present (Controlling_Argument (Par))
then
Set_Controlling_Argument (Par, Empty);
-- Prevent the search from going too far
elsif Is_Body_Or_Package_Declaration (Par) then
exit;
end if;
Par := Parent (Par);
end loop;
end Remove_Controlling_Arguments;
-- Local variables
Context : constant Node_Id :=
(if No (Ref) then Empty else Parent (Ref));
Loc : constant Source_Ptr := Sloc (Ref);
Ref_Id : Entity_Id;
Result : Traverse_Result;
New_Ref : Node_Id;
-- The new reference which is intended to substitute the old one
Old_Ref : Node_Id;
-- The reference designated for replacement. In certain cases this
-- may be a node other than Ref.
Val : Node_Or_Entity_Id;
-- The corresponding value of Ref from the type map
-- Start of processing for Replace_Ref
begin
-- Assume that the input reference is to be replaced and that the
-- traversal should examine the children of the reference.
Old_Ref := Ref;
Result := OK;
-- The input denotes a meaningful reference
if Nkind (Ref) in N_Has_Entity and then Present (Entity (Ref)) then
Ref_Id := Entity (Ref);
Val := Type_Map.Get (Ref_Id);
-- The reference has a corresponding value in the type map, a
-- substitution is possible.
if Present (Val) then
-- The reference denotes a discriminant
if Ekind (Ref_Id) = E_Discriminant then
if Nkind (Val) in N_Entity then
-- The value denotes another discriminant. Replace as
-- follows:
-- _object.Discr -> _object.Val
if Ekind (Val) = E_Discriminant then
New_Ref := New_Occurrence_Of (Val, Loc);
-- Otherwise the value denotes the entity of a name which
-- constraints the discriminant. Replace as follows:
-- _object.Discr -> Val
else
pragma Assert (Is_Deriv_Obj_Ref (Old_Ref));
New_Ref := New_Occurrence_Of (Val, Loc);
Old_Ref := Parent (Old_Ref);
end if;
-- Otherwise the value denotes an arbitrary expression which
-- constraints the discriminant. Replace as follows:
-- _object.Discr -> Val
else
pragma Assert (Is_Deriv_Obj_Ref (Old_Ref));
New_Ref := New_Copy_Tree (Val);
Old_Ref := Parent (Old_Ref);
end if;
-- Otherwise the reference denotes a primitive. Replace as
-- follows:
-- Primitive -> Val
else
pragma Assert (Nkind (Val) in N_Entity);
New_Ref := New_Occurrence_Of (Val, Loc);
end if;
-- The reference mentions the _object parameter of the parent
-- type's DIC or type invariant procedure. Replace as follows:
-- _object -> _object
elsif Present (Par_Obj)
and then Present (Deriv_Obj)
and then Ref_Id = Par_Obj
then
New_Ref := New_Occurrence_Of (Deriv_Obj, Loc);
-- The type of the _object parameter is class-wide when the
-- expression comes from an assertion pragma that applies to
-- an abstract parent type or an interface. The class-wide type
-- facilitates the preanalysis of the expression by treating
-- calls to abstract primitives that mention the current
-- instance of the type as dispatching. Once the calls are
-- remapped to invoke overriding or inherited primitives, the
-- calls no longer need to be dispatching. Examine all function
-- calls that encapsulate the _object parameter and reset their
-- Controlling_Argument attribute.
if Is_Class_Wide_Type (Etype (Par_Obj))
and then Is_Abstract_Type (Root_Type (Etype (Par_Obj)))
then
Remove_Controlling_Arguments (Old_Ref);
end if;
-- The reference to _object acts as an actual parameter in a
-- subprogram call which may be invoking a primitive of the
-- parent type:
-- Primitive (... _object ...);
-- The parent type primitive may not be overridden nor
-- inherited when it is declared after the derived type
-- definition:
-- type Parent is tagged private;
-- type Child is new Parent with private;
-- procedure Primitive (Obj : Parent);
-- In this scenario the _object parameter is converted to the
-- parent type. Due to complications with partial/full views
-- and view swaps, the parent type is taken from the formal
-- parameter of the subprogram being called.
if Nkind (Context) in N_Subprogram_Call
and then No (Type_Map.Get (Entity (Name (Context))))
then
declare
-- We need to use the Original_Node of the callee, in
-- case it was already modified. Note that we are using
-- Traverse_Proc to walk the tree, and it is defined to
-- walk subtrees in an arbitrary order.
Callee : constant Entity_Id :=
Entity (Original_Node (Name (Context)));
begin
if No (Type_Map.Get (Callee)) then
New_Ref :=
Convert_To
(Type_Of_Formal (Context, Old_Ref), New_Ref);
-- Do not process the generated type conversion
-- because both the parent type and the derived type
-- are in the Type_Map table. This will clobber the
-- type conversion by resetting its subtype mark.
Result := Skip;
end if;
end;
end if;
-- Otherwise there is nothing to replace
else
New_Ref := Empty;
end if;
if Present (New_Ref) then
Rewrite (Old_Ref, New_Ref);
-- Update the return type when the context of the reference
-- acts as the name of a function call. Note that the update
-- should not be performed when the reference appears as an
-- actual in the call.
if Nkind (Context) = N_Function_Call
and then Name (Context) = Old_Ref
then
Set_Etype (Context, Etype (Val));
end if;
end if;
end if;
-- Reanalyze the reference due to potential replacements
if Nkind (Old_Ref) in N_Has_Etype then
Set_Analyzed (Old_Ref, False);
end if;
return Result;
end Replace_Ref;
procedure Replace_Refs is new Traverse_Proc (Replace_Ref);
--------------------
-- Type_Of_Formal --
--------------------
function Type_Of_Formal
(Call : Node_Id;
Actual : Node_Id) return Entity_Id
is
A : Node_Id;
F : Entity_Id;
begin
-- Examine the list of actual and formal parameters in parallel
A := First (Parameter_Associations (Call));
F := First_Formal (Entity (Name (Call)));
while Present (A) and then Present (F) loop
if A = Actual then
return Etype (F);
end if;
Next (A);
Next_Formal (F);
end loop;
-- The actual parameter must always have a corresponding formal
pragma Assert (False);
return Empty;
end Type_Of_Formal;
-- Start of processing for Replace_References
begin
-- Map the attributes of the parent type to the proper corresponding
-- attributes of the derived type.
Map_Types
(Parent_Type => Par_Typ,
Derived_Type => Deriv_Typ);
-- Inspect the input expression and perform substitutions where
-- necessary.
Replace_Refs (Expr);
end Replace_References;
-----------------------------
-- Replace_Type_References --
-----------------------------
procedure Replace_Type_References
(Expr : Node_Id;
Typ : Entity_Id;
Obj_Id : Entity_Id)
is
procedure Replace_Type_Ref (N : Node_Id);
-- Substitute a single reference of the current instance of type Typ
-- with a reference to Obj_Id.
----------------------
-- Replace_Type_Ref --
----------------------
procedure Replace_Type_Ref (N : Node_Id) is
begin
-- Decorate the reference to Typ even though it may be rewritten
-- further down. This is done so that routines which examine
-- properties of the Original_Node have some semantic information.
if Nkind (N) = N_Identifier then
Set_Entity (N, Typ);
Set_Etype (N, Typ);
elsif Nkind (N) = N_Selected_Component then
Analyze (Prefix (N));
Set_Entity (Selector_Name (N), Typ);
Set_Etype (Selector_Name (N), Typ);
end if;
-- Perform the following substitution:
-- Typ --> _object
Rewrite (N, New_Occurrence_Of (Obj_Id, Sloc (N)));
Set_Comes_From_Source (N, True);
end Replace_Type_Ref;
procedure Replace_Type_Refs is
new Replace_Type_References_Generic (Replace_Type_Ref);
-- Start of processing for Replace_Type_References
begin
Replace_Type_Refs (Expr, Typ);
end Replace_Type_References;
---------------------------
-- Represented_As_Scalar --
---------------------------
function Represented_As_Scalar (T : Entity_Id) return Boolean is
UT : constant Entity_Id := Underlying_Type (T);
begin
return Is_Scalar_Type (UT)
or else (Is_Bit_Packed_Array (UT)
and then Is_Scalar_Type (Packed_Array_Impl_Type (UT)));
end Represented_As_Scalar;
------------------------------
-- Requires_Cleanup_Actions --
------------------------------
function Requires_Cleanup_Actions
(N : Node_Id;
Lib_Level : Boolean) return Boolean
is
At_Lib_Level : constant Boolean :=
Lib_Level
and then Nkind (N) in N_Package_Body | N_Package_Specification;
-- N is at the library level if the top-most context is a package and
-- the path taken to reach N does not include nonpackage constructs.
begin
case Nkind (N) is
when N_Accept_Statement
| N_Block_Statement
| N_Entry_Body
| N_Package_Body
| N_Protected_Body
| N_Subprogram_Body
| N_Task_Body
=>
return
Requires_Cleanup_Actions
(L => Declarations (N),
Lib_Level => At_Lib_Level,
Nested_Constructs => True)
or else
(Present (Handled_Statement_Sequence (N))
and then
Requires_Cleanup_Actions
(L =>
Statements (Handled_Statement_Sequence (N)),
Lib_Level => At_Lib_Level,
Nested_Constructs => True));
-- Extended return statements are the same as the above, except that
-- there is no Declarations field. We do not want to clean up the
-- Return_Object_Declarations.
when N_Extended_Return_Statement =>
return
Present (Handled_Statement_Sequence (N))
and then Requires_Cleanup_Actions
(L =>
Statements (Handled_Statement_Sequence (N)),
Lib_Level => At_Lib_Level,
Nested_Constructs => True);
when N_Package_Specification =>
return
Requires_Cleanup_Actions
(L => Visible_Declarations (N),
Lib_Level => At_Lib_Level,
Nested_Constructs => True)
or else
Requires_Cleanup_Actions
(L => Private_Declarations (N),
Lib_Level => At_Lib_Level,
Nested_Constructs => True);
when others =>
raise Program_Error;
end case;
end Requires_Cleanup_Actions;
------------------------------
-- Requires_Cleanup_Actions --
------------------------------
function Requires_Cleanup_Actions
(L : List_Id;
Lib_Level : Boolean;
Nested_Constructs : Boolean) return Boolean
is
Decl : Node_Id;
Expr : Node_Id;
Obj_Id : Entity_Id;
Obj_Typ : Entity_Id;
Pack_Id : Entity_Id;
Typ : Entity_Id;
begin
if No (L) or else Is_Empty_List (L) then
return False;
end if;
Decl := First (L);
while Present (Decl) loop
-- Library-level tagged types
if Nkind (Decl) = N_Full_Type_Declaration then
Typ := Defining_Identifier (Decl);
-- Ignored Ghost types do not need any cleanup actions because
-- they will not appear in the final tree.
if Is_Ignored_Ghost_Entity (Typ) then
null;
elsif Is_Tagged_Type (Typ)
and then Is_Library_Level_Entity (Typ)
and then Convention (Typ) = Convention_Ada
and then Present (Access_Disp_Table (Typ))
and then RTE_Available (RE_Unregister_Tag)
and then not Is_Abstract_Type (Typ)
and then not No_Run_Time_Mode
then
return True;
end if;
-- Regular object declarations
elsif Nkind (Decl) = N_Object_Declaration then
Obj_Id := Defining_Identifier (Decl);
Obj_Typ := Base_Type (Etype (Obj_Id));
Expr := Expression (Decl);
-- Bypass any form of processing for objects which have their
-- finalization disabled. This applies only to objects at the
-- library level.
if Lib_Level and then Finalize_Storage_Only (Obj_Typ) then
null;
-- Finalization of transient objects are treated separately in
-- order to handle sensitive cases. These include:
-- * Aggregate expansion
-- * If, case, and expression with actions expansion
-- * Transient scopes
-- If one of those contexts has marked the transient object as
-- ignored, do not generate finalization actions for it.
elsif Is_Finalized_Transient (Obj_Id)
or else Is_Ignored_Transient (Obj_Id)
then
null;
-- Ignored Ghost objects do not need any cleanup actions because
-- they will not appear in the final tree.
elsif Is_Ignored_Ghost_Entity (Obj_Id) then
null;
-- The object is of the form:
-- Obj : [constant] Typ [:= Expr];
--
-- Do not process tag-to-class-wide conversions because they do
-- not yield an object. Do not process the incomplete view of a
-- deferred constant. Note that an object initialized by means
-- of a build-in-place function call may appear as a deferred
-- constant after expansion activities. These kinds of objects
-- must be finalized.
elsif not Is_Imported (Obj_Id)
and then Needs_Finalization (Obj_Typ)
and then not Is_Tag_To_Class_Wide_Conversion (Obj_Id)
and then not (Ekind (Obj_Id) = E_Constant
and then not Has_Completion (Obj_Id)
and then No (BIP_Initialization_Call (Obj_Id)))
then
return True;
-- The object is of the form:
-- Obj : Access_Typ := Non_BIP_Function_Call'reference;
--
-- Obj : Access_Typ :=
-- BIP_Function_Call (BIPalloc => 2, ...)'reference;
elsif Is_Access_Type (Obj_Typ)
and then Needs_Finalization
(Available_View (Designated_Type (Obj_Typ)))
and then Present (Expr)
and then
(Is_Secondary_Stack_BIP_Func_Call (Expr)
or else
(Is_Non_BIP_Func_Call (Expr)
and then not Is_Related_To_Func_Return (Obj_Id)))
then
return True;
-- Processing for "hook" objects generated for transient objects
-- declared inside an Expression_With_Actions.
elsif Is_Access_Type (Obj_Typ)
and then Present (Status_Flag_Or_Transient_Decl (Obj_Id))
and then Nkind (Status_Flag_Or_Transient_Decl (Obj_Id)) =
N_Object_Declaration
then
return True;
-- Processing for intermediate results of if expressions where
-- one of the alternatives uses a controlled function call.
elsif Is_Access_Type (Obj_Typ)
and then Present (Status_Flag_Or_Transient_Decl (Obj_Id))
and then Nkind (Status_Flag_Or_Transient_Decl (Obj_Id)) =
N_Defining_Identifier
and then Present (Expr)
and then Nkind (Expr) = N_Null
then
return True;
-- Simple protected objects which use type System.Tasking.
-- Protected_Objects.Protection to manage their locks should be
-- treated as controlled since they require manual cleanup.
elsif Ekind (Obj_Id) = E_Variable
and then (Is_Simple_Protected_Type (Obj_Typ)
or else Has_Simple_Protected_Object (Obj_Typ))
then
return True;
end if;
-- Specific cases of object renamings
elsif Nkind (Decl) = N_Object_Renaming_Declaration then
Obj_Id := Defining_Identifier (Decl);
Obj_Typ := Base_Type (Etype (Obj_Id));
-- Bypass any form of processing for objects which have their
-- finalization disabled. This applies only to objects at the
-- library level.
if Lib_Level and then Finalize_Storage_Only (Obj_Typ) then
null;
-- Ignored Ghost object renamings do not need any cleanup actions
-- because they will not appear in the final tree.
elsif Is_Ignored_Ghost_Entity (Obj_Id) then
null;
-- Return object of a build-in-place function. This case is
-- recognized and marked by the expansion of an extended return
-- statement (see Expand_N_Extended_Return_Statement).
elsif Needs_Finalization (Obj_Typ)
and then Is_Return_Object (Obj_Id)
and then Present (Status_Flag_Or_Transient_Decl (Obj_Id))
then
return True;
-- Detect a case where a source object has been initialized by
-- a controlled function call or another object which was later
-- rewritten as a class-wide conversion of Ada.Tags.Displace.
-- Obj1 : CW_Type := Src_Obj;
-- Obj2 : CW_Type := Function_Call (...);
-- Obj1 : CW_Type renames (... Ada.Tags.Displace (Src_Obj));
-- Tmp : ... := Function_Call (...)'reference;
-- Obj2 : CW_Type renames (... Ada.Tags.Displace (Tmp));
elsif Is_Displacement_Of_Object_Or_Function_Result (Obj_Id) then
return True;
end if;
-- Inspect the freeze node of an access-to-controlled type and look
-- for a delayed finalization master. This case arises when the
-- freeze actions are inserted at a later time than the expansion of
-- the context. Since Build_Finalizer is never called on a single
-- construct twice, the master will be ultimately left out and never
-- finalized. This is also needed for freeze actions of designated
-- types themselves, since in some cases the finalization master is
-- associated with a designated type's freeze node rather than that
-- of the access type (see handling for freeze actions in
-- Build_Finalization_Master).
elsif Nkind (Decl) = N_Freeze_Entity
and then Present (Actions (Decl))
then
Typ := Entity (Decl);
-- Freeze nodes for ignored Ghost types do not need cleanup
-- actions because they will never appear in the final tree.
if Is_Ignored_Ghost_Entity (Typ) then
null;
elsif ((Is_Access_Object_Type (Typ)
and then Needs_Finalization
(Available_View (Designated_Type (Typ))))
or else (Is_Type (Typ) and then Needs_Finalization (Typ)))
and then Requires_Cleanup_Actions
(Actions (Decl), Lib_Level, Nested_Constructs)
then
return True;
end if;
-- Nested package declarations
elsif Nested_Constructs
and then Nkind (Decl) = N_Package_Declaration
then
Pack_Id := Defining_Entity (Decl);
-- Do not inspect an ignored Ghost package because all code found
-- within will not appear in the final tree.
if Is_Ignored_Ghost_Entity (Pack_Id) then
null;
elsif Ekind (Pack_Id) /= E_Generic_Package
and then Requires_Cleanup_Actions
(Specification (Decl), Lib_Level)
then
return True;
end if;
-- Nested package bodies
elsif Nested_Constructs and then Nkind (Decl) = N_Package_Body then
-- Do not inspect an ignored Ghost package body because all code
-- found within will not appear in the final tree.
if Is_Ignored_Ghost_Entity (Defining_Entity (Decl)) then
null;
elsif Ekind (Corresponding_Spec (Decl)) /= E_Generic_Package
and then Requires_Cleanup_Actions (Decl, Lib_Level)
then
return True;
end if;
elsif Nkind (Decl) = N_Block_Statement
and then
-- Handle a rare case caused by a controlled transient object
-- created as part of a record init proc. The variable is wrapped
-- in a block, but the block is not associated with a transient
-- scope.
(Inside_Init_Proc
-- Handle the case where the original context has been wrapped in
-- a block to avoid interference between exception handlers and
-- At_End handlers. Treat the block as transparent and process its
-- contents.
or else Is_Finalization_Wrapper (Decl))
then
if Requires_Cleanup_Actions (Decl, Lib_Level) then
return True;
end if;
end if;
Next (Decl);
end loop;
return False;
end Requires_Cleanup_Actions;
------------------------------------
-- Safe_Unchecked_Type_Conversion --
------------------------------------
-- Note: this function knows quite a bit about the exact requirements of
-- Gigi with respect to unchecked type conversions, and its code must be
-- coordinated with any changes in Gigi in this area.
-- The above requirements should be documented in Sinfo ???
function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is
Otyp : Entity_Id;
Ityp : Entity_Id;
Oalign : Uint;
Ialign : Uint;
Pexp : constant Node_Id := Parent (Exp);
begin
-- If the expression is the RHS of an assignment or object declaration
-- we are always OK because there will always be a target.
-- Object renaming declarations, (generated for view conversions of
-- actuals in inlined calls), like object declarations, provide an
-- explicit type, and are safe as well.
if (Nkind (Pexp) = N_Assignment_Statement
and then Expression (Pexp) = Exp)
or else Nkind (Pexp)
in N_Object_Declaration | N_Object_Renaming_Declaration
then
return True;
-- If the expression is the prefix of an N_Selected_Component we should
-- also be OK because GCC knows to look inside the conversion except if
-- the type is discriminated. We assume that we are OK anyway if the
-- type is not set yet or if it is controlled since we can't afford to
-- introduce a temporary in this case.
elsif Nkind (Pexp) = N_Selected_Component
and then Prefix (Pexp) = Exp
then
return No (Etype (Pexp))
or else not Is_Type (Etype (Pexp))
or else not Has_Discriminants (Etype (Pexp))
or else Is_Constrained (Etype (Pexp));
end if;
-- Set the output type, this comes from Etype if it is set, otherwise we
-- take it from the subtype mark, which we assume was already fully
-- analyzed.
if Present (Etype (Exp)) then
Otyp := Etype (Exp);
else
Otyp := Entity (Subtype_Mark (Exp));
end if;
-- The input type always comes from the expression, and we assume this
-- is indeed always analyzed, so we can simply get the Etype.
Ityp := Etype (Expression (Exp));
-- Initialize alignments to unknown so far
Oalign := No_Uint;
Ialign := No_Uint;
-- Replace a concurrent type by its corresponding record type and each
-- type by its underlying type and do the tests on those. The original
-- type may be a private type whose completion is a concurrent type, so
-- find the underlying type first.
if Present (Underlying_Type (Otyp)) then
Otyp := Underlying_Type (Otyp);
end if;
if Present (Underlying_Type (Ityp)) then
Ityp := Underlying_Type (Ityp);
end if;
if Is_Concurrent_Type (Otyp) then
Otyp := Corresponding_Record_Type (Otyp);
end if;
if Is_Concurrent_Type (Ityp) then
Ityp := Corresponding_Record_Type (Ityp);
end if;
-- If the base types are the same, we know there is no problem since
-- this conversion will be a noop.
if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then
return True;
-- Same if this is an upwards conversion of an untagged type, and there
-- are no constraints involved (could be more general???)
elsif Etype (Ityp) = Otyp
and then not Is_Tagged_Type (Ityp)
and then not Has_Discriminants (Ityp)
and then No (First_Rep_Item (Base_Type (Ityp)))
then
return True;
-- If the expression has an access type (object or subprogram) we assume
-- that the conversion is safe, because the size of the target is safe,
-- even if it is a record (which might be treated as having unknown size
-- at this point).
elsif Is_Access_Type (Ityp) then
return True;
-- If the size of output type is known at compile time, there is never
-- a problem. Note that unconstrained records are considered to be of
-- known size, but we can't consider them that way here, because we are
-- talking about the actual size of the object.
-- We also make sure that in addition to the size being known, we do not
-- have a case which might generate an embarrassingly large temp in
-- stack checking mode.
elsif Size_Known_At_Compile_Time (Otyp)
and then
(not Stack_Checking_Enabled
or else not May_Generate_Large_Temp (Otyp))
and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp))
then
return True;
-- If either type is tagged, then we know the alignment is OK so Gigi
-- will be able to use pointer punning.
elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then
return True;
-- If either type is a limited record type, we cannot do a copy, so say
-- safe since there's nothing else we can do.
elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then
return True;
-- Conversions to and from packed array types are always ignored and
-- hence are safe.
elsif Is_Packed_Array_Impl_Type (Otyp)
or else Is_Packed_Array_Impl_Type (Ityp)
then
return True;
end if;
-- The only other cases known to be safe is if the input type's
-- alignment is known to be at least the maximum alignment for the
-- target or if both alignments are known and the output type's
-- alignment is no stricter than the input's. We can use the component
-- type alignment for an array if a type is an unpacked array type.
if Present (Alignment_Clause (Otyp)) then
Oalign := Expr_Value (Expression (Alignment_Clause (Otyp)));
elsif Is_Array_Type (Otyp)
and then Present (Alignment_Clause (Component_Type (Otyp)))
then
Oalign := Expr_Value (Expression (Alignment_Clause
(Component_Type (Otyp))));
end if;
if Present (Alignment_Clause (Ityp)) then
Ialign := Expr_Value (Expression (Alignment_Clause (Ityp)));
elsif Is_Array_Type (Ityp)
and then Present (Alignment_Clause (Component_Type (Ityp)))
then
Ialign := Expr_Value (Expression (Alignment_Clause
(Component_Type (Ityp))));
end if;
if Present (Ialign) and then Ialign > Maximum_Alignment then
return True;
elsif Present (Ialign)
and then Present (Oalign)
and then Ialign <= Oalign
then
return True;
-- Otherwise, Gigi cannot handle this and we must make a temporary
else
return False;
end if;
end Safe_Unchecked_Type_Conversion;
---------------------------------
-- Set_Current_Value_Condition --
---------------------------------
-- Note: the implementation of this procedure is very closely tied to the
-- implementation of Get_Current_Value_Condition. Here we set required
-- Current_Value fields, and in Get_Current_Value_Condition, we interpret
-- them, so they must have a consistent view.
procedure Set_Current_Value_Condition (Cnode : Node_Id) is
procedure Set_Entity_Current_Value (N : Node_Id);
-- If N is an entity reference, where the entity is of an appropriate
-- kind, then set the current value of this entity to Cnode, unless
-- there is already a definite value set there.
procedure Set_Expression_Current_Value (N : Node_Id);
-- If N is of an appropriate form, sets an appropriate entry in current
-- value fields of relevant entities. Multiple entities can be affected
-- in the case of an AND or AND THEN.
------------------------------
-- Set_Entity_Current_Value --
------------------------------
procedure Set_Entity_Current_Value (N : Node_Id) is
begin
if Is_Entity_Name (N) then
declare
Ent : constant Entity_Id := Entity (N);
begin
-- Don't capture if not safe to do so
if not Safe_To_Capture_Value (N, Ent, Cond => True) then
return;
end if;
-- Here we have a case where the Current_Value field may need
-- to be set. We set it if it is not already set to a compile
-- time expression value.
-- Note that this represents a decision that one condition
-- blots out another previous one. That's certainly right if
-- they occur at the same level. If the second one is nested,
-- then the decision is neither right nor wrong (it would be
-- equally OK to leave the outer one in place, or take the new
-- inner one). Really we should record both, but our data
-- structures are not that elaborate.
if Nkind (Current_Value (Ent)) not in N_Subexpr then
Set_Current_Value (Ent, Cnode);
end if;
end;
end if;
end Set_Entity_Current_Value;
----------------------------------
-- Set_Expression_Current_Value --
----------------------------------
procedure Set_Expression_Current_Value (N : Node_Id) is
Cond : Node_Id;
begin
Cond := N;
-- Loop to deal with (ignore for now) any NOT operators present. The
-- presence of NOT operators will be handled properly when we call
-- Get_Current_Value_Condition.
while Nkind (Cond) = N_Op_Not loop
Cond := Right_Opnd (Cond);
end loop;
-- For an AND or AND THEN, recursively process operands
if Nkind (Cond) = N_Op_And or else Nkind (Cond) = N_And_Then then
Set_Expression_Current_Value (Left_Opnd (Cond));
Set_Expression_Current_Value (Right_Opnd (Cond));
return;
end if;
-- Check possible relational operator
if Nkind (Cond) in N_Op_Compare then
if Compile_Time_Known_Value (Right_Opnd (Cond)) then
Set_Entity_Current_Value (Left_Opnd (Cond));
elsif Compile_Time_Known_Value (Left_Opnd (Cond)) then
Set_Entity_Current_Value (Right_Opnd (Cond));
end if;
elsif Nkind (Cond) in N_Type_Conversion
| N_Qualified_Expression
| N_Expression_With_Actions
then
Set_Expression_Current_Value (Expression (Cond));
-- Check possible boolean variable reference
else
Set_Entity_Current_Value (Cond);
end if;
end Set_Expression_Current_Value;
-- Start of processing for Set_Current_Value_Condition
begin
Set_Expression_Current_Value (Condition (Cnode));
end Set_Current_Value_Condition;
--------------------------
-- Set_Elaboration_Flag --
--------------------------
procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
Ent : constant Entity_Id := Elaboration_Entity (Spec_Id);
Asn : Node_Id;
begin
if Present (Ent) then
-- Nothing to do if at the compilation unit level, because in this
-- case the flag is set by the binder generated elaboration routine.
if Nkind (Parent (N)) = N_Compilation_Unit then
null;
-- Here we do need to generate an assignment statement
else
Check_Restriction (No_Elaboration_Code, N);
Asn :=
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Ent, Loc),
Expression => Make_Integer_Literal (Loc, Uint_1));
-- Mark the assignment statement as elaboration code. This allows
-- the early call region mechanism (see Sem_Elab) to properly
-- ignore such assignments even though they are nonpreelaborable
-- code.
Set_Is_Elaboration_Code (Asn);
if Nkind (Parent (N)) = N_Subunit then
Insert_After (Corresponding_Stub (Parent (N)), Asn);
else
Insert_After (N, Asn);
end if;
Analyze (Asn);
-- Kill current value indication. This is necessary because the
-- tests of this flag are inserted out of sequence and must not
-- pick up bogus indications of the wrong constant value.
Set_Current_Value (Ent, Empty);
-- If the subprogram is in the current declarative part and
-- 'access has been applied to it, generate an elaboration
-- check at the beginning of the declarations of the body.
if Nkind (N) = N_Subprogram_Body
and then Address_Taken (Spec_Id)
and then
Ekind (Scope (Spec_Id)) in E_Block | E_Procedure | E_Function
then
declare
Loc : constant Source_Ptr := Sloc (N);
Decls : constant List_Id := Declarations (N);
Chk : Node_Id;
begin
-- No need to generate this check if first entry in the
-- declaration list is a raise of Program_Error now.
if Present (Decls)
and then Nkind (First (Decls)) = N_Raise_Program_Error
then
return;
end if;
-- Otherwise generate the check
Chk :=
Make_Raise_Program_Error (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd => New_Occurrence_Of (Ent, Loc),
Right_Opnd => Make_Integer_Literal (Loc, Uint_0)),
Reason => PE_Access_Before_Elaboration);
if No (Decls) then
Set_Declarations (N, New_List (Chk));
else
Prepend (Chk, Decls);
end if;
Analyze (Chk);
end;
end if;
end if;
end if;
end Set_Elaboration_Flag;
----------------------------
-- Set_Renamed_Subprogram --
----------------------------
procedure Set_Renamed_Subprogram (N : Node_Id; E : Entity_Id) is
begin
-- If input node is an identifier, we can just reset it
if Nkind (N) = N_Identifier then
Set_Chars (N, Chars (E));
Set_Entity (N, E);
-- Otherwise we have to do a rewrite, preserving Comes_From_Source
else
declare
CS : constant Boolean := Comes_From_Source (N);
begin
Rewrite (N, Make_Identifier (Sloc (N), Chars (E)));
Set_Entity (N, E);
Set_Comes_From_Source (N, CS);
Set_Analyzed (N, True);
end;
end if;
end Set_Renamed_Subprogram;
----------------------
-- Side_Effect_Free --
----------------------
function Side_Effect_Free
(N : Node_Id;
Name_Req : Boolean := False;
Variable_Ref : Boolean := False) return Boolean
is
Typ : constant Entity_Id := Etype (N);
-- Result type of the expression
function Safe_Prefixed_Reference (N : Node_Id) return Boolean;
-- The argument N is a construct where the Prefix is dereferenced if it
-- is an access type and the result is a variable. The call returns True
-- if the construct is side effect free (not considering side effects in
-- other than the prefix which are to be tested by the caller).
function Within_In_Parameter (N : Node_Id) return Boolean;
-- Determines if N is a subcomponent of a composite in-parameter. If so,
-- N is not side-effect free when the actual is global and modifiable
-- indirectly from within a subprogram, because it may be passed by
-- reference. The front-end must be conservative here and assume that
-- this may happen with any array or record type. On the other hand, we
-- cannot create temporaries for all expressions for which this
-- condition is true, for various reasons that might require clearing up
-- ??? For example, discriminant references that appear out of place, or
-- spurious type errors with class-wide expressions. As a result, we
-- limit the transformation to loop bounds, which is so far the only
-- case that requires it.
-----------------------------
-- Safe_Prefixed_Reference --
-----------------------------
function Safe_Prefixed_Reference (N : Node_Id) return Boolean is
begin
-- If prefix is not side effect free, definitely not safe
if not Side_Effect_Free (Prefix (N), Name_Req, Variable_Ref) then
return False;
-- If the prefix is of an access type that is not access-to-constant,
-- then this construct is a variable reference, which means it is to
-- be considered to have side effects if Variable_Ref is set True.
elsif Is_Access_Type (Etype (Prefix (N)))
and then not Is_Access_Constant (Etype (Prefix (N)))
and then Variable_Ref
then
-- Exception is a prefix that is the result of a previous removal
-- of side effects.
return Is_Entity_Name (Prefix (N))
and then not Comes_From_Source (Prefix (N))
and then Ekind (Entity (Prefix (N))) = E_Constant
and then Is_Internal_Name (Chars (Entity (Prefix (N))));
-- If the prefix is an explicit dereference then this construct is a
-- variable reference, which means it is to be considered to have
-- side effects if Variable_Ref is True.
-- We do NOT exclude dereferences of access-to-constant types because
-- we handle them as constant view of variables.
elsif Nkind (Prefix (N)) = N_Explicit_Dereference
and then Variable_Ref
then
return False;
-- Note: The following test is the simplest way of solving a complex
-- problem uncovered by the following test (Side effect on loop bound
-- that is a subcomponent of a global variable:
-- with Text_Io; use Text_Io;
-- procedure Tloop is
-- type X is
-- record
-- V : Natural := 4;
-- S : String (1..5) := (others => 'a');
-- end record;
-- X1 : X;
-- procedure Modi;
-- generic
-- with procedure Action;
-- procedure Loop_G (Arg : X; Msg : String)
-- procedure Loop_G (Arg : X; Msg : String) is
-- begin
-- Put_Line ("begin loop_g " & Msg & " will loop till: "
-- & Natural'Image (Arg.V));
-- for Index in 1 .. Arg.V loop
-- Text_Io.Put_Line
-- (Natural'Image (Index) & " " & Arg.S (Index));
-- if Index > 2 then
-- Modi;
-- end if;
-- end loop;
-- Put_Line ("end loop_g " & Msg);
-- end;
-- procedure Loop1 is new Loop_G (Modi);
-- procedure Modi is
-- begin
-- X1.V := 1;
-- Loop1 (X1, "from modi");
-- end;
--
-- begin
-- Loop1 (X1, "initial");
-- end;
-- The output of the above program should be:
-- begin loop_g initial will loop till: 4
-- 1 a
-- 2 a
-- 3 a
-- begin loop_g from modi will loop till: 1
-- 1 a
-- end loop_g from modi
-- 4 a
-- begin loop_g from modi will loop till: 1
-- 1 a
-- end loop_g from modi
-- end loop_g initial
-- If a loop bound is a subcomponent of a global variable, a
-- modification of that variable within the loop may incorrectly
-- affect the execution of the loop.
elsif Parent_Kind (Parent (N)) = N_Loop_Parameter_Specification
and then Within_In_Parameter (Prefix (N))
and then Variable_Ref
then
return False;
-- All other cases are side effect free
else
return True;
end if;
end Safe_Prefixed_Reference;
-------------------------
-- Within_In_Parameter --
-------------------------
function Within_In_Parameter (N : Node_Id) return Boolean is
begin
if not Comes_From_Source (N) then
return False;
elsif Is_Entity_Name (N) then
return Ekind (Entity (N)) = E_In_Parameter;
elsif Nkind (N) in N_Indexed_Component | N_Selected_Component then
return Within_In_Parameter (Prefix (N));
else
return False;
end if;
end Within_In_Parameter;
-- Start of processing for Side_Effect_Free
begin
-- If volatile reference, always consider it to have side effects
if Is_Volatile_Reference (N) then
return False;
end if;
-- Note on checks that could raise Constraint_Error. Strictly, if we
-- take advantage of 11.6, these checks do not count as side effects.
-- However, we would prefer to consider that they are side effects,
-- since the back end CSE does not work very well on expressions which
-- can raise Constraint_Error. On the other hand if we don't consider
-- them to be side effect free, then we get some awkward expansions
-- in -gnato mode, resulting in code insertions at a point where we
-- do not have a clear model for performing the insertions.
-- Special handling for entity names
if Is_Entity_Name (N) then
-- A type reference is always side effect free
if Is_Type (Entity (N)) then
return True;
-- Variables are considered to be a side effect if Variable_Ref
-- is set or if we have a volatile reference and Name_Req is off.
-- If Name_Req is True then we can't help returning a name which
-- effectively allows multiple references in any case.
elsif Is_Variable (N, Use_Original_Node => False) then
return not Variable_Ref
and then (not Is_Volatile_Reference (N) or else Name_Req);
-- Any other entity (e.g. a subtype name) is definitely side
-- effect free.
else
return True;
end if;
-- A value known at compile time is always side effect free
elsif Compile_Time_Known_Value (N) then
return True;
-- A variable renaming is not side-effect free, because the renaming
-- will function like a macro in the front-end in some cases, and an
-- assignment can modify the component designated by N, so we need to
-- create a temporary for it.
-- The guard testing for Entity being present is needed at least in
-- the case of rewritten predicate expressions, and may well also be
-- appropriate elsewhere. Obviously we can't go testing the entity
-- field if it does not exist, so it's reasonable to say that this is
-- not the renaming case if it does not exist.
elsif Is_Entity_Name (Original_Node (N))
and then Present (Entity (Original_Node (N)))
and then Is_Renaming_Of_Object (Entity (Original_Node (N)))
and then Ekind (Entity (Original_Node (N))) /= E_Constant
then
declare
RO : constant Node_Id :=
Renamed_Object (Entity (Original_Node (N)));
begin
-- If the renamed object is an indexed component, or an
-- explicit dereference, then the designated object could
-- be modified by an assignment.
if Nkind (RO) in N_Indexed_Component | N_Explicit_Dereference then
return False;
-- A selected component must have a safe prefix
elsif Nkind (RO) = N_Selected_Component then
return Safe_Prefixed_Reference (RO);
-- In all other cases, designated object cannot be changed so
-- we are side effect free.
else
return True;
end if;
end;
-- Remove_Side_Effects generates an object renaming declaration to
-- capture the expression of a class-wide expression. In VM targets
-- the frontend performs no expansion for dispatching calls to
-- class- wide types since they are handled by the VM. Hence, we must
-- locate here if this node corresponds to a previous invocation of
-- Remove_Side_Effects to avoid a never ending loop in the frontend.
elsif not Tagged_Type_Expansion
and then not Comes_From_Source (N)
and then Nkind (Parent (N)) = N_Object_Renaming_Declaration
and then Is_Class_Wide_Type (Typ)
then
return True;
-- Generating C the type conversion of an access to constrained array
-- type into an access to unconstrained array type involves initializing
-- a fat pointer and the expression cannot be assumed to be free of side
-- effects since it must referenced several times to compute its bounds.
elsif Modify_Tree_For_C
and then Nkind (N) = N_Type_Conversion
and then Is_Access_Type (Typ)
and then Is_Array_Type (Designated_Type (Typ))
and then not Is_Constrained (Designated_Type (Typ))
then
return False;
end if;
-- For other than entity names and compile time known values,
-- check the node kind for special processing.
case Nkind (N) is
-- An attribute reference is side-effect free if its expressions
-- are side-effect free and its prefix is side-effect free or is
-- an entity reference.
when N_Attribute_Reference =>
return Side_Effect_Free_Attribute (Attribute_Name (N))
and then
Side_Effect_Free (Expressions (N), Name_Req, Variable_Ref)
and then
(Is_Entity_Name (Prefix (N))
or else
Side_Effect_Free (Prefix (N), Name_Req, Variable_Ref));
-- A binary operator is side effect free if and both operands are
-- side effect free. For this purpose binary operators include
-- short circuit forms.
when N_Binary_Op
| N_Short_Circuit
=>
return Side_Effect_Free (Left_Opnd (N), Name_Req, Variable_Ref)
and then
Side_Effect_Free (Right_Opnd (N), Name_Req, Variable_Ref);
-- Membership tests may have either Right_Opnd or Alternatives set
when N_Membership_Test =>
return Side_Effect_Free (Left_Opnd (N), Name_Req, Variable_Ref)
and then
(if Present (Right_Opnd (N))
then Side_Effect_Free
(Right_Opnd (N), Name_Req, Variable_Ref)
else Side_Effect_Free
(Alternatives (N), Name_Req, Variable_Ref));
-- An explicit dereference is side effect free only if it is
-- a side effect free prefixed reference.
when N_Explicit_Dereference =>
return Safe_Prefixed_Reference (N);
-- An expression with action is side effect free if its expression
-- is side effect free and it has no actions.
when N_Expression_With_Actions =>
return
Is_Empty_List (Actions (N))
and then Side_Effect_Free
(Expression (N), Name_Req, Variable_Ref);
-- A call to _rep_to_pos is side effect free, since we generate
-- this pure function call ourselves. Moreover it is critically
-- important to make this exception, since otherwise we can have
-- discriminants in array components which don't look side effect
-- free in the case of an array whose index type is an enumeration
-- type with an enumeration rep clause.
-- All other function calls are not side effect free
when N_Function_Call =>
return
Nkind (Name (N)) = N_Identifier
and then Is_TSS (Name (N), TSS_Rep_To_Pos)
and then Side_Effect_Free
(First (Parameter_Associations (N)),
Name_Req, Variable_Ref);
-- An IF expression is side effect free if it's of a scalar type, and
-- all its components are all side effect free (conditions and then
-- actions and else actions). We restrict to scalar types, since it
-- is annoying to deal with things like (if A then B else C)'First
-- where the type involved is a string type.
when N_If_Expression =>
return
Is_Scalar_Type (Typ)
and then Side_Effect_Free
(Expressions (N), Name_Req, Variable_Ref);
-- An indexed component is side effect free if it is a side
-- effect free prefixed reference and all the indexing
-- expressions are side effect free.
when N_Indexed_Component =>
return
Side_Effect_Free (Expressions (N), Name_Req, Variable_Ref)
and then Safe_Prefixed_Reference (N);
-- A type qualification, type conversion, or unchecked expression is
-- side effect free if the expression is side effect free.
when N_Qualified_Expression
| N_Type_Conversion
| N_Unchecked_Expression
=>
return Side_Effect_Free (Expression (N), Name_Req, Variable_Ref);
-- A selected component is side effect free only if it is a side
-- effect free prefixed reference.
when N_Selected_Component =>
return Safe_Prefixed_Reference (N);
-- A range is side effect free if the bounds are side effect free
when N_Range =>
return Side_Effect_Free (Low_Bound (N), Name_Req, Variable_Ref)
and then
Side_Effect_Free (High_Bound (N), Name_Req, Variable_Ref);
-- A slice is side effect free if it is a side effect free
-- prefixed reference and the bounds are side effect free.
when N_Slice =>
return
Side_Effect_Free (Discrete_Range (N), Name_Req, Variable_Ref)
and then Safe_Prefixed_Reference (N);
-- A unary operator is side effect free if the operand
-- is side effect free.
when N_Unary_Op =>
return Side_Effect_Free (Right_Opnd (N), Name_Req, Variable_Ref);
-- An unchecked type conversion is side effect free only if it
-- is safe and its argument is side effect free.
when N_Unchecked_Type_Conversion =>
return
Safe_Unchecked_Type_Conversion (N)
and then Side_Effect_Free
(Expression (N), Name_Req, Variable_Ref);
-- A literal is side effect free
when N_Character_Literal
| N_Integer_Literal
| N_Real_Literal
| N_String_Literal
=>
return True;
-- An aggregate is side effect free if all its values are compile
-- time known.
when N_Aggregate =>
return Compile_Time_Known_Aggregate (N);
-- We consider that anything else has side effects. This is a bit
-- crude, but we are pretty close for most common cases, and we
-- are certainly correct (i.e. we never return True when the
-- answer should be False).
when others =>
return False;
end case;
end Side_Effect_Free;
-- A list is side effect free if all elements of the list are side
-- effect free.
function Side_Effect_Free
(L : List_Id;
Name_Req : Boolean := False;
Variable_Ref : Boolean := False) return Boolean
is
N : Node_Id;
begin
if L = No_List or else L = Error_List then
return True;
else
N := First (L);
while Present (N) loop
if not Side_Effect_Free (N, Name_Req, Variable_Ref) then
return False;
else
Next (N);
end if;
end loop;
return True;
end if;
end Side_Effect_Free;
--------------------------------
-- Side_Effect_Free_Attribute --
--------------------------------
function Side_Effect_Free_Attribute (Name : Name_Id) return Boolean is
begin
case Name is
when Name_Input =>
return False;
when Name_Image
| Name_Img
| Name_Wide_Image
| Name_Wide_Wide_Image
=>
-- CodePeer doesn't want to see replicated copies of 'Image calls
return not CodePeer_Mode;
when others =>
return True;
end case;
end Side_Effect_Free_Attribute;
----------------------------------
-- Silly_Boolean_Array_Not_Test --
----------------------------------
-- This procedure implements an odd and silly test. We explicitly check
-- for the case where the 'First of the component type is equal to the
-- 'Last of this component type, and if this is the case, we make sure
-- that constraint error is raised. The reason is that the NOT is bound
-- to cause CE in this case, and we will not otherwise catch it.
-- No such check is required for AND and OR, since for both these cases
-- False op False = False, and True op True = True. For the XOR case,
-- see Silly_Boolean_Array_Xor_Test.
-- Believe it or not, this was reported as a bug. Note that nearly always,
-- the test will evaluate statically to False, so the code will be
-- statically removed, and no extra overhead caused.
procedure Silly_Boolean_Array_Not_Test (N : Node_Id; T : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
CT : constant Entity_Id := Component_Type (T);
begin
-- The check we install is
-- constraint_error when
-- component_type'first = component_type'last
-- and then array_type'Length /= 0)
-- We need the last guard because we don't want to raise CE for empty
-- arrays since no out of range values result. (Empty arrays with a
-- component type of True .. True -- very useful -- even the ACATS
-- does not test that marginal case).
Insert_Action (N,
Make_Raise_Constraint_Error (Loc,
Condition =>
Make_And_Then (Loc,
Left_Opnd =>
Make_Op_Eq (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (CT, Loc),
Attribute_Name => Name_First),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (CT, Loc),
Attribute_Name => Name_Last)),
Right_Opnd => Make_Non_Empty_Check (Loc, Right_Opnd (N))),
Reason => CE_Range_Check_Failed));
end Silly_Boolean_Array_Not_Test;
----------------------------------
-- Silly_Boolean_Array_Xor_Test --
----------------------------------
-- This procedure implements an odd and silly test. We explicitly check
-- for the XOR case where the component type is True .. True, since this
-- will raise constraint error. A special check is required since CE
-- will not be generated otherwise (cf Expand_Packed_Not).
-- No such check is required for AND and OR, since for both these cases
-- False op False = False, and True op True = True, and no check is
-- required for the case of False .. False, since False xor False = False.
-- See also Silly_Boolean_Array_Not_Test
procedure Silly_Boolean_Array_Xor_Test
(N : Node_Id;
R : Node_Id;
T : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
CT : constant Entity_Id := Component_Type (T);
begin
-- The check we install is
-- constraint_error when
-- Boolean (component_type'First)
-- and then Boolean (component_type'Last)
-- and then array_type'Length /= 0)
-- We need the last guard because we don't want to raise CE for empty
-- arrays since no out of range values result (Empty arrays with a
-- component type of True .. True -- very useful -- even the ACATS
-- does not test that marginal case).
Insert_Action (N,
Make_Raise_Constraint_Error (Loc,
Condition =>
Make_And_Then (Loc,
Left_Opnd =>
Make_And_Then (Loc,
Left_Opnd =>
Convert_To (Standard_Boolean,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (CT, Loc),
Attribute_Name => Name_First)),
Right_Opnd =>
Convert_To (Standard_Boolean,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (CT, Loc),
Attribute_Name => Name_Last))),
Right_Opnd => Make_Non_Empty_Check (Loc, R)),
Reason => CE_Range_Check_Failed));
end Silly_Boolean_Array_Xor_Test;
----------------------------
-- Small_Integer_Type_For --
----------------------------
function Small_Integer_Type_For (S : Uint; Uns : Boolean) return Entity_Id
is
begin
pragma Assert (S <= System_Max_Integer_Size);
if S <= Standard_Short_Short_Integer_Size then
if Uns then
return Standard_Short_Short_Unsigned;
else
return Standard_Short_Short_Integer;
end if;
elsif S <= Standard_Short_Integer_Size then
if Uns then
return Standard_Short_Unsigned;
else
return Standard_Short_Integer;
end if;
elsif S <= Standard_Integer_Size then
if Uns then
return Standard_Unsigned;
else
return Standard_Integer;
end if;
elsif S <= Standard_Long_Integer_Size then
if Uns then
return Standard_Long_Unsigned;
else
return Standard_Long_Integer;
end if;
elsif S <= Standard_Long_Long_Integer_Size then
if Uns then
return Standard_Long_Long_Unsigned;
else
return Standard_Long_Long_Integer;
end if;
elsif S <= Standard_Long_Long_Long_Integer_Size then
if Uns then
return Standard_Long_Long_Long_Unsigned;
else
return Standard_Long_Long_Long_Integer;
end if;
else
raise Program_Error;
end if;
end Small_Integer_Type_For;
-------------------
-- Type_Map_Hash --
-------------------
function Type_Map_Hash (Id : Entity_Id) return Type_Map_Header is
begin
return Type_Map_Header (Id mod Type_Map_Size);
end Type_Map_Hash;
------------------------------------------
-- Type_May_Have_Bit_Aligned_Components --
------------------------------------------
function Type_May_Have_Bit_Aligned_Components
(Typ : Entity_Id) return Boolean
is
begin
-- Array type, check component type
if Is_Array_Type (Typ) then
return
Type_May_Have_Bit_Aligned_Components (Component_Type (Typ));
-- Record type, check components
elsif Is_Record_Type (Typ) then
declare
E : Entity_Id;
begin
E := First_Component_Or_Discriminant (Typ);
while Present (E) loop
-- This is the crucial test: if the component itself causes
-- trouble, then we can stop and return True.
if Component_May_Be_Bit_Aligned (E) then
return True;
end if;
-- Otherwise, we need to test its type, to see if it may
-- itself contain a troublesome component.
if Type_May_Have_Bit_Aligned_Components (Etype (E)) then
return True;
end if;
Next_Component_Or_Discriminant (E);
end loop;
return False;
end;
-- Type other than array or record is always OK
else
return False;
end if;
end Type_May_Have_Bit_Aligned_Components;
-------------------------------
-- Update_Primitives_Mapping --
-------------------------------
procedure Update_Primitives_Mapping
(Inher_Id : Entity_Id;
Subp_Id : Entity_Id)
is
Parent_Type : constant Entity_Id := Find_Dispatching_Type (Inher_Id);
Derived_Type : constant Entity_Id := Find_Dispatching_Type (Subp_Id);
begin
pragma Assert (Parent_Type /= Derived_Type);
Map_Types (Parent_Type, Derived_Type);
end Update_Primitives_Mapping;
----------------------------------
-- Within_Case_Or_If_Expression --
----------------------------------
function Within_Case_Or_If_Expression (N : Node_Id) return Boolean is
Par : Node_Id;
begin
-- Locate an enclosing case or if expression. Note that these constructs
-- can be expanded into Expression_With_Actions, hence the test of the
-- original node.
Par := Parent (N);
while Present (Par) loop
if Nkind (Original_Node (Par)) in N_Case_Expression | N_If_Expression
then
return True;
-- Prevent the search from going too far
elsif Is_Body_Or_Package_Declaration (Par) then
return False;
end if;
Par := Parent (Par);
end loop;
return False;
end Within_Case_Or_If_Expression;
------------------------------
-- Predicate_Check_In_Scope --
------------------------------
function Predicate_Check_In_Scope (N : Node_Id) return Boolean is
S : Entity_Id;
begin
S := Current_Scope;
while Present (S) and then not Is_Subprogram (S) loop
S := Scope (S);
end loop;
if Present (S) then
-- Predicate checks should only be enabled in init procs for
-- expressions coming from source.
if Is_Init_Proc (S) then
return Comes_From_Source (N);
elsif Get_TSS_Name (S) /= TSS_Null
and then not Is_Predicate_Function (S)
and then not Is_Predicate_Function_M (S)
then
return False;
end if;
end if;
return True;
end Predicate_Check_In_Scope;
end Exp_Util;