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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ C H 6 --
-- --
-- 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 Atree; use Atree;
with Aspects; use Aspects;
with Checks; use Checks;
with Contracts; use Contracts;
with Debug; use Debug;
with Einfo; use Einfo;
with Einfo.Entities; use Einfo.Entities;
with Einfo.Utils; use Einfo.Utils;
with Errout; use Errout;
with Elists; use Elists;
with Expander; use Expander;
with Exp_Aggr; use Exp_Aggr;
with Exp_Atag; use Exp_Atag;
with Exp_Ch3; use Exp_Ch3;
with Exp_Ch7; use Exp_Ch7;
with Exp_Ch9; use Exp_Ch9;
with Exp_Dbug; use Exp_Dbug;
with Exp_Disp; use Exp_Disp;
with Exp_Dist; use Exp_Dist;
with Exp_Intr; use Exp_Intr;
with Exp_Pakd; use Exp_Pakd;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Freeze; use Freeze;
with Inline; use Inline;
with Itypes; use Itypes;
with Lib; use Lib;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch13; use Sem_Ch13;
with Sem_Dim; use Sem_Dim;
with Sem_Disp; use Sem_Disp;
with Sem_Dist; use Sem_Dist;
with Sem_Eval; use Sem_Eval;
with Sem_Mech; use Sem_Mech;
with Sem_Res; use Sem_Res;
with Sem_SCIL; use Sem_SCIL;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Sinfo.Nodes; use Sinfo.Nodes;
with Sinfo.Utils; use Sinfo.Utils;
with Sinput; use Sinput;
with Snames; use Snames;
with Stand; use Stand;
with Stringt; use Stringt;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
with Validsw; use Validsw;
package body Exp_Ch6 is
-- Suffix for BIP formals
BIP_Alloc_Suffix : constant String := "BIPalloc";
BIP_Storage_Pool_Suffix : constant String := "BIPstoragepool";
BIP_Finalization_Master_Suffix : constant String := "BIPfinalizationmaster";
BIP_Task_Master_Suffix : constant String := "BIPtaskmaster";
BIP_Activation_Chain_Suffix : constant String := "BIPactivationchain";
BIP_Object_Access_Suffix : constant String := "BIPaccess";
-----------------------
-- Local Subprograms --
-----------------------
procedure Add_Access_Actual_To_Build_In_Place_Call
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Return_Object : Node_Id;
Is_Access : Boolean := False);
-- Ada 2005 (AI-318-02): Apply the Unrestricted_Access attribute to the
-- object name given by Return_Object and add the attribute to the end of
-- the actual parameter list associated with the build-in-place function
-- call denoted by Function_Call. However, if Is_Access is True, then
-- Return_Object is already an access expression, in which case it's passed
-- along directly to the build-in-place function. Finally, if Return_Object
-- is empty, then pass a null literal as the actual.
procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Alloc_Form : BIP_Allocation_Form := Unspecified;
Alloc_Form_Exp : Node_Id := Empty;
Pool_Actual : Node_Id := Make_Null (No_Location));
-- Ada 2005 (AI-318-02): Add the actuals needed for a build-in-place
-- function call that returns a caller-unknown-size result (BIP_Alloc_Form
-- and BIP_Storage_Pool). If Alloc_Form_Exp is present, then use it,
-- otherwise pass a literal corresponding to the Alloc_Form parameter
-- (which must not be Unspecified in that case). Pool_Actual is the
-- parameter to pass to BIP_Storage_Pool.
procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
(Func_Call : Node_Id;
Func_Id : Entity_Id;
Ptr_Typ : Entity_Id := Empty;
Master_Exp : Node_Id := Empty);
-- Ada 2005 (AI-318-02): If the result type of a build-in-place call needs
-- finalization actions, add an actual parameter which is a pointer to the
-- finalization master of the caller. If Master_Exp is not Empty, then that
-- will be passed as the actual. Otherwise, if Ptr_Typ is left Empty, this
-- will result in an automatic "null" value for the actual.
procedure Add_Task_Actuals_To_Build_In_Place_Call
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Master_Actual : Node_Id;
Chain : Node_Id := Empty);
-- Ada 2005 (AI-318-02): For a build-in-place call, if the result type
-- contains tasks, add two actual parameters: the master, and a pointer to
-- the caller's activation chain. Master_Actual is the actual parameter
-- expression to pass for the master. In most cases, this is the current
-- master (_master). The two exceptions are: If the function call is the
-- initialization expression for an allocator, we pass the master of the
-- access type. If the function call is the initialization expression for a
-- return object, we pass along the master passed in by the caller. In most
-- contexts, the activation chain to pass is the local one, which is
-- indicated by No (Chain). However, in an allocator, the caller passes in
-- the activation Chain. Note: Master_Actual can be Empty, but only if
-- there are no tasks.
procedure Apply_CW_Accessibility_Check (Exp : Node_Id; Func : Entity_Id);
-- Ada 2005 (AI95-344): If the result type is class-wide, insert a check
-- that the level of the return expression's underlying type is not deeper
-- than the level of the master enclosing the function. Always generate the
-- check when the type of the return expression is class-wide, when it's a
-- type conversion, or when it's a formal parameter. Otherwise suppress the
-- check in the case where the return expression has a specific type whose
-- level is known not to be statically deeper than the result type of the
-- function.
function Caller_Known_Size
(Func_Call : Node_Id;
Result_Subt : Entity_Id) return Boolean;
-- True if result subtype is definite, or has a size that does not require
-- secondary stack usage (i.e. no variant part or components whose type
-- depends on discriminants). In particular, untagged types with only
-- access discriminants do not require secondary stack use. Note we must
-- always use the secondary stack for dispatching-on-result calls.
function Check_BIP_Actuals
(Subp_Call : Node_Id;
Subp_Id : Entity_Id) return Boolean;
-- Given a subprogram call to the given subprogram return True if the
-- names of BIP extra actual and formal parameters match.
function Check_Number_Of_Actuals
(Subp_Call : Node_Id;
Subp_Id : Entity_Id) return Boolean;
-- Given a subprogram call to the given subprogram return True if the
-- number of actual parameters (including extra actuals) is correct.
procedure Check_Overriding_Operation (Subp : Entity_Id);
-- Subp is a dispatching operation. Check whether it may override an
-- inherited private operation, in which case its DT entry is that of
-- the hidden operation, not the one it may have received earlier.
-- This must be done before emitting the code to set the corresponding
-- DT to the address of the subprogram. The actual placement of Subp in
-- the proper place in the list of primitive operations is done in
-- Declare_Inherited_Private_Subprograms, which also has to deal with
-- implicit operations. This duplication is unavoidable for now???
procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id);
-- This procedure is called only if the subprogram body N, whose spec
-- has the given entity Spec, contains a parameterless recursive call.
-- It attempts to generate runtime code to detect if this a case of
-- infinite recursion.
--
-- The body is scanned to determine dependencies. If the only external
-- dependencies are on a small set of scalar variables, then the values
-- of these variables are captured on entry to the subprogram, and if
-- the values are not changed for the call, we know immediately that
-- we have an infinite recursion.
procedure Expand_Actuals
(N : Node_Id;
Subp : Entity_Id;
Post_Call : out List_Id);
-- Return a list of actions to take place after the call in Post_Call. The
-- call will later be rewritten as an Expression_With_Actions, with the
-- Post_Call actions inserted, and the call inside.
--
-- For each actual of an in-out or out parameter which is a numeric (view)
-- conversion of the form T (A), where A denotes a variable, we insert the
-- declaration:
--
-- Temp : T[ := T (A)];
--
-- prior to the call. Then we replace the actual with a reference to Temp,
-- and append the assignment:
--
-- A := TypeA (Temp);
--
-- after the call. Here TypeA is the actual type of variable A. For out
-- parameters, the initial declaration has no expression. If A is not an
-- entity name, we generate instead:
--
-- Var : TypeA renames A;
-- Temp : T := Var; -- omitting expression for out parameter.
-- ...
-- Var := TypeA (Temp);
--
-- For other in-out parameters, we emit the required constraint checks
-- before and/or after the call.
--
-- For all parameter modes, actuals that denote components and slices of
-- packed arrays are expanded into suitable temporaries.
--
-- For nonscalar objects that are possibly unaligned, add call by copy code
-- (copy in for IN and IN OUT, copy out for OUT and IN OUT).
--
-- For OUT and IN OUT parameters, add predicate checks after the call
-- based on the predicates of the actual type.
procedure Expand_Call_Helper (N : Node_Id; Post_Call : out List_Id);
-- Does the main work of Expand_Call. Post_Call is as for Expand_Actuals.
procedure Expand_Ctrl_Function_Call (N : Node_Id);
-- N is a function call which returns a controlled object. Transform the
-- call into a temporary which retrieves the returned object from the
-- secondary stack using 'reference.
procedure Expand_Non_Function_Return (N : Node_Id);
-- Expand a simple return statement found in a procedure body, entry body,
-- accept statement, or an extended return statement. Note that all non-
-- function returns are simple return statements.
function Expand_Protected_Object_Reference
(N : Node_Id;
Scop : Entity_Id) return Node_Id;
procedure Expand_Protected_Subprogram_Call
(N : Node_Id;
Subp : Entity_Id;
Scop : Entity_Id);
-- A call to a protected subprogram within the protected object may appear
-- as a regular call. The list of actuals must be expanded to contain a
-- reference to the object itself, and the call becomes a call to the
-- corresponding protected subprogram.
procedure Expand_Simple_Function_Return (N : Node_Id);
-- Expand simple return from function. In the case where we are returning
-- from a function body this is called by Expand_N_Simple_Return_Statement.
function Has_BIP_Extra_Formal
(E : Entity_Id;
Kind : BIP_Formal_Kind) return Boolean;
-- Given a frozen subprogram, subprogram type, entry or entry family,
-- return True if E has the BIP extra formal associated with Kind. It must
-- be invoked with a frozen entity or a subprogram type of a dispatching
-- call since we can only rely on the availability of the extra formals
-- on these entities.
procedure Insert_Post_Call_Actions (N : Node_Id; Post_Call : List_Id);
-- Insert the Post_Call list previously produced by routine Expand_Actuals
-- or Expand_Call_Helper into the tree.
procedure Replace_Renaming_Declaration_Id
(New_Decl : Node_Id;
Orig_Decl : Node_Id);
-- Replace the internal identifier of the new renaming declaration New_Decl
-- with the identifier of its original declaration Orig_Decl exchanging the
-- entities containing their defining identifiers to ensure the correct
-- replacement of the object declaration by the object renaming declaration
-- to avoid homograph conflicts (since the object declaration's defining
-- identifier was already entered in the current scope). The Next_Entity
-- links of the two entities are also swapped since the entities are part
-- of the return scope's entity list and the list structure would otherwise
-- be corrupted. The homonym chain is preserved as well.
procedure Rewrite_Function_Call_For_C (N : Node_Id);
-- When generating C code, replace a call to a function that returns an
-- array into the generated procedure with an additional out parameter.
procedure Set_Enclosing_Sec_Stack_Return (N : Node_Id);
-- N is a return statement for a function that returns its result on the
-- secondary stack. This sets the Sec_Stack_Needed_For_Return flag on the
-- function and all blocks and loops that the return statement is jumping
-- out of. This ensures that the secondary stack is not released; otherwise
-- the function result would be reclaimed before returning to the caller.
procedure Warn_BIP (Func_Call : Node_Id);
-- Give a warning on a build-in-place function call if the -gnatd_B switch
-- was given.
----------------------------------------------
-- Add_Access_Actual_To_Build_In_Place_Call --
----------------------------------------------
procedure Add_Access_Actual_To_Build_In_Place_Call
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Return_Object : Node_Id;
Is_Access : Boolean := False)
is
Loc : constant Source_Ptr := Sloc (Function_Call);
Obj_Address : Node_Id;
Obj_Acc_Formal : Entity_Id;
begin
-- Locate the implicit access parameter in the called function
Obj_Acc_Formal := Build_In_Place_Formal (Function_Id, BIP_Object_Access);
-- If no return object is provided, then pass null
if not Present (Return_Object) then
Obj_Address := Make_Null (Loc);
Set_Parent (Obj_Address, Function_Call);
-- If Return_Object is already an expression of an access type, then use
-- it directly, since it must be an access value denoting the return
-- object, and couldn't possibly be the return object itself.
elsif Is_Access then
Obj_Address := Return_Object;
Set_Parent (Obj_Address, Function_Call);
-- Apply Unrestricted_Access to caller's return object
else
Obj_Address :=
Make_Attribute_Reference (Loc,
Prefix => Return_Object,
Attribute_Name => Name_Unrestricted_Access);
Set_Parent (Return_Object, Obj_Address);
Set_Parent (Obj_Address, Function_Call);
end if;
Analyze_And_Resolve (Obj_Address, Etype (Obj_Acc_Formal));
-- Build the parameter association for the new actual and add it to the
-- end of the function's actuals.
Add_Extra_Actual_To_Call (Function_Call, Obj_Acc_Formal, Obj_Address);
end Add_Access_Actual_To_Build_In_Place_Call;
------------------------------------------------------
-- Add_Unconstrained_Actuals_To_Build_In_Place_Call --
------------------------------------------------------
procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Alloc_Form : BIP_Allocation_Form := Unspecified;
Alloc_Form_Exp : Node_Id := Empty;
Pool_Actual : Node_Id := Make_Null (No_Location))
is
Loc : constant Source_Ptr := Sloc (Function_Call);
Alloc_Form_Actual : Node_Id;
Alloc_Form_Formal : Node_Id;
Pool_Formal : Node_Id;
begin
-- Nothing to do when the size of the object is known, and the caller is
-- in charge of allocating it, and the callee doesn't unconditionally
-- require an allocation form (such as due to having a tagged result).
if not Needs_BIP_Alloc_Form (Function_Id) then
return;
end if;
-- Locate the implicit allocation form parameter in the called function.
-- Maybe it would be better for each implicit formal of a build-in-place
-- function to have a flag or a Uint attribute to identify it. ???
Alloc_Form_Formal := Build_In_Place_Formal (Function_Id, BIP_Alloc_Form);
if Present (Alloc_Form_Exp) then
pragma Assert (Alloc_Form = Unspecified);
Alloc_Form_Actual := Alloc_Form_Exp;
else
pragma Assert (Alloc_Form /= Unspecified);
Alloc_Form_Actual :=
Make_Integer_Literal (Loc,
Intval => UI_From_Int (BIP_Allocation_Form'Pos (Alloc_Form)));
end if;
Analyze_And_Resolve (Alloc_Form_Actual, Etype (Alloc_Form_Formal));
-- Build the parameter association for the new actual and add it to the
-- end of the function's actuals.
Add_Extra_Actual_To_Call
(Function_Call, Alloc_Form_Formal, Alloc_Form_Actual);
-- Pass the Storage_Pool parameter. This parameter is omitted on ZFP as
-- those targets do not support pools.
if RTE_Available (RE_Root_Storage_Pool_Ptr) then
Pool_Formal := Build_In_Place_Formal (Function_Id, BIP_Storage_Pool);
Analyze_And_Resolve (Pool_Actual, Etype (Pool_Formal));
Add_Extra_Actual_To_Call
(Function_Call, Pool_Formal, Pool_Actual);
end if;
end Add_Unconstrained_Actuals_To_Build_In_Place_Call;
-----------------------------------------------------------
-- Add_Finalization_Master_Actual_To_Build_In_Place_Call --
-----------------------------------------------------------
procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
(Func_Call : Node_Id;
Func_Id : Entity_Id;
Ptr_Typ : Entity_Id := Empty;
Master_Exp : Node_Id := Empty)
is
begin
if not Needs_BIP_Finalization_Master (Func_Id) then
return;
end if;
declare
Formal : constant Entity_Id :=
Build_In_Place_Formal (Func_Id, BIP_Finalization_Master);
Loc : constant Source_Ptr := Sloc (Func_Call);
Actual : Node_Id;
Desig_Typ : Entity_Id;
begin
-- If there is a finalization master actual, such as the implicit
-- finalization master of an enclosing build-in-place function,
-- then this must be added as an extra actual of the call.
if Present (Master_Exp) then
Actual := Master_Exp;
-- Case where the context does not require an actual master
elsif No (Ptr_Typ) then
Actual := Make_Null (Loc);
else
Desig_Typ := Directly_Designated_Type (Ptr_Typ);
-- Check for a library-level access type whose designated type has
-- suppressed finalization or the access type is subject to pragma
-- No_Heap_Finalization. Such an access type lacks a master. Pass
-- a null actual to callee in order to signal a missing master.
if Is_Library_Level_Entity (Ptr_Typ)
and then (Finalize_Storage_Only (Desig_Typ)
or else No_Heap_Finalization (Ptr_Typ))
then
Actual := Make_Null (Loc);
-- Types in need of finalization actions
elsif Needs_Finalization (Desig_Typ) then
-- The general mechanism of creating finalization masters for
-- anonymous access types is disabled by default, otherwise
-- finalization masters will pop all over the place. Such types
-- use context-specific masters.
if Ekind (Ptr_Typ) = E_Anonymous_Access_Type
and then No (Finalization_Master (Ptr_Typ))
then
Build_Anonymous_Master (Ptr_Typ);
end if;
-- Access-to-controlled types should always have a master
pragma Assert (Present (Finalization_Master (Ptr_Typ)));
Actual :=
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Finalization_Master (Ptr_Typ), Loc),
Attribute_Name => Name_Unrestricted_Access);
-- Tagged types
else
Actual := Make_Null (Loc);
end if;
end if;
Analyze_And_Resolve (Actual, Etype (Formal));
-- Build the parameter association for the new actual and add it to
-- the end of the function's actuals.
Add_Extra_Actual_To_Call (Func_Call, Formal, Actual);
end;
end Add_Finalization_Master_Actual_To_Build_In_Place_Call;
------------------------------
-- Add_Extra_Actual_To_Call --
------------------------------
procedure Add_Extra_Actual_To_Call
(Subprogram_Call : Node_Id;
Extra_Formal : Entity_Id;
Extra_Actual : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Subprogram_Call);
Param_Assoc : Node_Id;
begin
Param_Assoc :=
Make_Parameter_Association (Loc,
Selector_Name => New_Occurrence_Of (Extra_Formal, Loc),
Explicit_Actual_Parameter => Extra_Actual);
Set_Parent (Param_Assoc, Subprogram_Call);
Set_Parent (Extra_Actual, Param_Assoc);
if Present (Parameter_Associations (Subprogram_Call)) then
if Nkind (Last (Parameter_Associations (Subprogram_Call))) =
N_Parameter_Association
then
-- Find last named actual, and append
declare
L : Node_Id;
begin
L := First_Actual (Subprogram_Call);
while Present (L) loop
if No (Next_Actual (L)) then
Set_Next_Named_Actual (Parent (L), Extra_Actual);
exit;
end if;
Next_Actual (L);
end loop;
end;
else
Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
end if;
Append (Param_Assoc, To => Parameter_Associations (Subprogram_Call));
else
Set_Parameter_Associations (Subprogram_Call, New_List (Param_Assoc));
Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
end if;
end Add_Extra_Actual_To_Call;
---------------------------------------------
-- Add_Task_Actuals_To_Build_In_Place_Call --
---------------------------------------------
procedure Add_Task_Actuals_To_Build_In_Place_Call
(Function_Call : Node_Id;
Function_Id : Entity_Id;
Master_Actual : Node_Id;
Chain : Node_Id := Empty)
is
Loc : constant Source_Ptr := Sloc (Function_Call);
Actual : Node_Id;
Chain_Actual : Node_Id;
Chain_Formal : Node_Id;
Master_Formal : Node_Id;
begin
-- No such extra parameters are needed if there are no tasks
if not Needs_BIP_Task_Actuals (Function_Id) then
return;
end if;
Actual := Master_Actual;
-- Use a dummy _master actual in case of No_Task_Hierarchy
if Restriction_Active (No_Task_Hierarchy) then
Actual := Make_Integer_Literal (Loc, Library_Task_Level);
-- In the case where we use the master associated with an access type,
-- the actual is an entity and requires an explicit reference.
elsif Nkind (Actual) = N_Defining_Identifier then
Actual := New_Occurrence_Of (Actual, Loc);
end if;
-- Locate the implicit master parameter in the called function
Master_Formal := Build_In_Place_Formal (Function_Id, BIP_Task_Master);
Analyze_And_Resolve (Actual, Etype (Master_Formal));
-- Build the parameter association for the new actual and add it to the
-- end of the function's actuals.
Add_Extra_Actual_To_Call (Function_Call, Master_Formal, Actual);
-- Locate the implicit activation chain parameter in the called function
Chain_Formal :=
Build_In_Place_Formal (Function_Id, BIP_Activation_Chain);
-- Create the actual which is a pointer to the current activation chain
if No (Chain) then
Chain_Actual :=
Make_Attribute_Reference (Loc,
Prefix => Make_Identifier (Loc, Name_uChain),
Attribute_Name => Name_Unrestricted_Access);
-- Allocator case; make a reference to the Chain passed in by the caller
else
Chain_Actual :=
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Chain, Loc),
Attribute_Name => Name_Unrestricted_Access);
end if;
Analyze_And_Resolve (Chain_Actual, Etype (Chain_Formal));
-- Build the parameter association for the new actual and add it to the
-- end of the function's actuals.
Add_Extra_Actual_To_Call (Function_Call, Chain_Formal, Chain_Actual);
end Add_Task_Actuals_To_Build_In_Place_Call;
----------------------------------
-- Apply_CW_Accessibility_Check --
----------------------------------
procedure Apply_CW_Accessibility_Check (Exp : Node_Id; Func : Entity_Id) is
Loc : constant Source_Ptr := Sloc (Exp);
begin
if Ada_Version >= Ada_2005
and then Tagged_Type_Expansion
and then not Scope_Suppress.Suppress (Accessibility_Check)
and then
(Is_Class_Wide_Type (Etype (Exp))
or else Nkind (Exp) in
N_Type_Conversion | N_Unchecked_Type_Conversion
or else (Is_Entity_Name (Exp)
and then Is_Formal (Entity (Exp)))
or else Scope_Depth (Enclosing_Dynamic_Scope (Etype (Exp))) >
Scope_Depth (Enclosing_Dynamic_Scope (Func)))
then
declare
Tag_Node : Node_Id;
begin
-- Ada 2005 (AI-251): In class-wide interface objects we displace
-- "this" to reference the base of the object. This is required to
-- get access to the TSD of the object.
if Is_Class_Wide_Type (Etype (Exp))
and then Is_Interface (Etype (Exp))
then
-- If the expression is an explicit dereference then we can
-- directly displace the pointer to reference the base of
-- the object.
if Nkind (Exp) = N_Explicit_Dereference then
Tag_Node :=
Make_Explicit_Dereference (Loc,
Prefix =>
Unchecked_Convert_To (RTE (RE_Tag_Ptr),
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Base_Address), Loc),
Parameter_Associations => New_List (
Unchecked_Convert_To (RTE (RE_Address),
Duplicate_Subexpr (Prefix (Exp)))))));
-- Similar case to the previous one but the expression is a
-- renaming of an explicit dereference.
elsif Nkind (Exp) = N_Identifier
and then Present (Renamed_Object (Entity (Exp)))
and then Nkind (Renamed_Object (Entity (Exp)))
= N_Explicit_Dereference
then
Tag_Node :=
Make_Explicit_Dereference (Loc,
Prefix =>
Unchecked_Convert_To (RTE (RE_Tag_Ptr),
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Base_Address), Loc),
Parameter_Associations => New_List (
Unchecked_Convert_To (RTE (RE_Address),
Duplicate_Subexpr
(Prefix
(Renamed_Object (Entity (Exp)))))))));
-- Common case: obtain the address of the actual object and
-- displace the pointer to reference the base of the object.
else
Tag_Node :=
Make_Explicit_Dereference (Loc,
Prefix =>
Unchecked_Convert_To (RTE (RE_Tag_Ptr),
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Base_Address), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr (Exp),
Attribute_Name => Name_Address)))));
end if;
else
Tag_Node :=
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr (Exp),
Attribute_Name => Name_Tag);
end if;
-- CodePeer does not do anything useful with
-- Ada.Tags.Type_Specific_Data components.
if not CodePeer_Mode then
Insert_Action (Exp,
Make_Raise_Program_Error (Loc,
Condition =>
Make_Op_Gt (Loc,
Left_Opnd => Build_Get_Access_Level (Loc, Tag_Node),
Right_Opnd =>
Make_Integer_Literal (Loc,
Scope_Depth (Enclosing_Dynamic_Scope (Func)))),
Reason => PE_Accessibility_Check_Failed));
end if;
end;
end if;
end Apply_CW_Accessibility_Check;
-----------------------
-- BIP_Formal_Suffix --
-----------------------
function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String is
begin
case Kind is
when BIP_Alloc_Form =>
return BIP_Alloc_Suffix;
when BIP_Storage_Pool =>
return BIP_Storage_Pool_Suffix;
when BIP_Finalization_Master =>
return BIP_Finalization_Master_Suffix;
when BIP_Task_Master =>
return BIP_Task_Master_Suffix;
when BIP_Activation_Chain =>
return BIP_Activation_Chain_Suffix;
when BIP_Object_Access =>
return BIP_Object_Access_Suffix;
end case;
end BIP_Formal_Suffix;
---------------------
-- BIP_Suffix_Kind --
---------------------
function BIP_Suffix_Kind (E : Entity_Id) return BIP_Formal_Kind is
Nam : constant String := Get_Name_String (Chars (E));
function Has_Suffix (Suffix : String) return Boolean;
-- Return True if Nam has suffix Suffix
function Has_Suffix (Suffix : String) return Boolean is
Len : constant Natural := Suffix'Length;
begin
return Nam'Length > Len
and then Nam (Nam'Last - Len + 1 .. Nam'Last) = Suffix;
end Has_Suffix;
-- Start of processing for BIP_Suffix_Kind
begin
if Has_Suffix (BIP_Alloc_Suffix) then
return BIP_Alloc_Form;
elsif Has_Suffix (BIP_Storage_Pool_Suffix) then
return BIP_Storage_Pool;
elsif Has_Suffix (BIP_Finalization_Master_Suffix) then
return BIP_Finalization_Master;
elsif Has_Suffix (BIP_Task_Master_Suffix) then
return BIP_Task_Master;
elsif Has_Suffix (BIP_Activation_Chain_Suffix) then
return BIP_Activation_Chain;
elsif Has_Suffix (BIP_Object_Access_Suffix) then
return BIP_Object_Access;
else
raise Program_Error;
end if;
end BIP_Suffix_Kind;
---------------------------
-- Build_In_Place_Formal --
---------------------------
function Build_In_Place_Formal
(Func : Entity_Id;
Kind : BIP_Formal_Kind) return Entity_Id
is
Extra_Formal : Entity_Id := Extra_Formals (Func);
Formal_Suffix : constant String := BIP_Formal_Suffix (Kind);
begin
-- Maybe it would be better for each implicit formal of a build-in-place
-- function to have a flag or a Uint attribute to identify it. ???
-- The return type in the function declaration may have been a limited
-- view, and the extra formals for the function were not generated at
-- that point. At the point of call the full view must be available and
-- the extra formals can be created.
if No (Extra_Formal) then
Create_Extra_Formals (Func);
Extra_Formal := Extra_Formals (Func);
end if;
-- We search for a formal with a matching suffix. We can't search
-- for the full name, because of the code at the end of Sem_Ch6.-
-- Create_Extra_Formals, which copies the Extra_Formals over to
-- the Alias of an instance, which will cause the formals to have
-- "incorrect" names.
loop
pragma Assert (Present (Extra_Formal));
declare
Name : constant String := Get_Name_String (Chars (Extra_Formal));
begin
exit when Name'Length >= Formal_Suffix'Length
and then Formal_Suffix =
Name (Name'Last - Formal_Suffix'Length + 1 .. Name'Last);
end;
Next_Formal_With_Extras (Extra_Formal);
end loop;
return Extra_Formal;
end Build_In_Place_Formal;
-------------------------------
-- Build_Procedure_Body_Form --
-------------------------------
function Build_Procedure_Body_Form
(Func_Id : Entity_Id;
Func_Body : Node_Id) return Node_Id
is
Loc : constant Source_Ptr := Sloc (Func_Body);
Proc_Decl : constant Node_Id := Prev (Unit_Declaration_Node (Func_Id));
-- It is assumed that the node before the declaration of the
-- corresponding subprogram spec is the declaration of the procedure
-- form.
Proc_Id : constant Entity_Id := Defining_Entity (Proc_Decl);
procedure Replace_Returns (Param_Id : Entity_Id; Stmts : List_Id);
-- Replace each return statement found in the list Stmts with an
-- assignment of the return expression to parameter Param_Id.
---------------------
-- Replace_Returns --
---------------------
procedure Replace_Returns (Param_Id : Entity_Id; Stmts : List_Id) is
Stmt : Node_Id;
begin
Stmt := First (Stmts);
while Present (Stmt) loop
if Nkind (Stmt) = N_Block_Statement then
Replace_Returns (Param_Id,
Statements (Handled_Statement_Sequence (Stmt)));
elsif Nkind (Stmt) = N_Case_Statement then
declare
Alt : Node_Id;
begin
Alt := First (Alternatives (Stmt));
while Present (Alt) loop
Replace_Returns (Param_Id, Statements (Alt));
Next (Alt);
end loop;
end;
elsif Nkind (Stmt) = N_Extended_Return_Statement then
declare
Ret_Obj : constant Entity_Id :=
Defining_Entity
(First (Return_Object_Declarations (Stmt)));
Assign : constant Node_Id :=
Make_Assignment_Statement (Sloc (Stmt),
Name =>
New_Occurrence_Of (Param_Id, Loc),
Expression =>
New_Occurrence_Of (Ret_Obj, Sloc (Stmt)));
Stmts : List_Id;
begin
-- The extended return may just contain the declaration
if Present (Handled_Statement_Sequence (Stmt)) then
Stmts := Statements (Handled_Statement_Sequence (Stmt));
else
Stmts := New_List;
end if;
Set_Assignment_OK (Name (Assign));
Rewrite (Stmt,
Make_Block_Statement (Sloc (Stmt),
Declarations =>
Return_Object_Declarations (Stmt),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stmts)));
Replace_Returns (Param_Id, Stmts);
Append_To (Stmts, Assign);
Append_To (Stmts, Make_Simple_Return_Statement (Loc));
end;
elsif Nkind (Stmt) = N_If_Statement then
Replace_Returns (Param_Id, Then_Statements (Stmt));
Replace_Returns (Param_Id, Else_Statements (Stmt));
declare
Part : Node_Id;
begin
Part := First (Elsif_Parts (Stmt));
while Present (Part) loop
Replace_Returns (Param_Id, Then_Statements (Part));
Next (Part);
end loop;
end;
elsif Nkind (Stmt) = N_Loop_Statement then
Replace_Returns (Param_Id, Statements (Stmt));
elsif Nkind (Stmt) = N_Simple_Return_Statement then
-- Generate:
-- Param := Expr;
-- return;
Rewrite (Stmt,
Make_Assignment_Statement (Sloc (Stmt),
Name => New_Occurrence_Of (Param_Id, Loc),
Expression => Relocate_Node (Expression (Stmt))));
Insert_After (Stmt, Make_Simple_Return_Statement (Loc));
-- Skip the added return
Next (Stmt);
end if;
Next (Stmt);
end loop;
end Replace_Returns;
-- Local variables
Stmts : List_Id;
New_Body : Node_Id;
-- Start of processing for Build_Procedure_Body_Form
begin
-- This routine replaces the original function body:
-- function F (...) return Array_Typ is
-- begin
-- ...
-- return Something;
-- end F;
-- with the following:
-- procedure P (..., Result : out Array_Typ) is
-- begin
-- ...
-- Result := Something;
-- end P;
Stmts :=
Statements (Handled_Statement_Sequence (Func_Body));
Replace_Returns (Last_Entity (Proc_Id), Stmts);
New_Body :=
Make_Subprogram_Body (Loc,
Specification =>
Copy_Subprogram_Spec (Specification (Proc_Decl)),
Declarations => Declarations (Func_Body),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stmts));
-- If the function is a generic instance, so is the new procedure.
-- Set flag accordingly so that the proper renaming declarations are
-- generated.
Set_Is_Generic_Instance (Proc_Id, Is_Generic_Instance (Func_Id));
return New_Body;
end Build_Procedure_Body_Form;
-----------------------
-- Caller_Known_Size --
-----------------------
function Caller_Known_Size
(Func_Call : Node_Id;
Result_Subt : Entity_Id) return Boolean
is
begin
return
(Is_Definite_Subtype (Underlying_Type (Result_Subt))
and then No (Controlling_Argument (Func_Call)))
or else not Requires_Transient_Scope (Underlying_Type (Result_Subt));
end Caller_Known_Size;
-----------------------
-- Check_BIP_Actuals --
-----------------------
function Check_BIP_Actuals
(Subp_Call : Node_Id;
Subp_Id : Entity_Id) return Boolean
is
Formal : Entity_Id;
Actual : Node_Id;
begin
pragma Assert (Nkind (Subp_Call) in N_Entry_Call_Statement
| N_Function_Call
| N_Procedure_Call_Statement);
Formal := First_Formal_With_Extras (Subp_Id);
Actual := First_Actual (Subp_Call);
while Present (Formal) and then Present (Actual) loop
if Is_Build_In_Place_Entity (Formal)
and then Nkind (Actual) = N_Identifier
and then Is_Build_In_Place_Entity (Entity (Actual))
and then BIP_Suffix_Kind (Formal)
/= BIP_Suffix_Kind (Entity (Actual))
then
return False;
end if;
Next_Formal_With_Extras (Formal);
Next_Actual (Actual);
end loop;
return No (Formal) and then No (Actual);
end Check_BIP_Actuals;
-----------------------------
-- Check_Number_Of_Actuals --
-----------------------------
function Check_Number_Of_Actuals
(Subp_Call : Node_Id;
Subp_Id : Entity_Id) return Boolean
is
Formal : Entity_Id;
Actual : Node_Id;
begin
pragma Assert (Nkind (Subp_Call) in N_Entry_Call_Statement
| N_Function_Call
| N_Procedure_Call_Statement);
Formal := First_Formal_With_Extras (Subp_Id);
Actual := First_Actual (Subp_Call);
while Present (Formal) and then Present (Actual) loop
Next_Formal_With_Extras (Formal);
Next_Actual (Actual);
end loop;
return No (Formal) and then No (Actual);
end Check_Number_Of_Actuals;
--------------------------------
-- Check_Overriding_Operation --
--------------------------------
procedure Check_Overriding_Operation (Subp : Entity_Id) is
Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
Op_List : constant Elist_Id := Primitive_Operations (Typ);
Op_Elmt : Elmt_Id;
Prim_Op : Entity_Id;
Par_Op : Entity_Id;
begin
if Is_Derived_Type (Typ)
and then not Is_Private_Type (Typ)
and then In_Open_Scopes (Scope (Etype (Typ)))
and then Is_Base_Type (Typ)
then
-- Subp overrides an inherited private operation if there is an
-- inherited operation with a different name than Subp (see
-- Derive_Subprogram) whose Alias is a hidden subprogram with the
-- same name as Subp.
Op_Elmt := First_Elmt (Op_List);
while Present (Op_Elmt) loop
Prim_Op := Node (Op_Elmt);
Par_Op := Alias (Prim_Op);
if Present (Par_Op)
and then not Comes_From_Source (Prim_Op)
and then Chars (Prim_Op) /= Chars (Par_Op)
and then Chars (Par_Op) = Chars (Subp)
and then Is_Hidden (Par_Op)
and then Type_Conformant (Prim_Op, Subp)
then
Set_DT_Position_Value (Subp, DT_Position (Prim_Op));
end if;
Next_Elmt (Op_Elmt);
end loop;
end if;
end Check_Overriding_Operation;
-------------------------------
-- Detect_Infinite_Recursion --
-------------------------------
procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
Var_List : constant Elist_Id := New_Elmt_List;
-- List of globals referenced by body of procedure
Call_List : constant Elist_Id := New_Elmt_List;
-- List of recursive calls in body of procedure
Shad_List : constant Elist_Id := New_Elmt_List;
-- List of entity id's for entities created to capture the value of
-- referenced globals on entry to the procedure.
Scop : constant Uint := Scope_Depth (Spec);
-- This is used to record the scope depth of the current procedure, so
-- that we can identify global references.
Max_Vars : constant := 4;
-- Do not test more than four global variables
Count_Vars : Natural := 0;
-- Count variables found so far
Var : Entity_Id;
Elm : Elmt_Id;
Ent : Entity_Id;
Call : Elmt_Id;
Decl : Node_Id;
Test : Node_Id;
Elm1 : Elmt_Id;
Elm2 : Elmt_Id;
Last : Node_Id;
function Process (Nod : Node_Id) return Traverse_Result;
-- Function to traverse the subprogram body (using Traverse_Func)
-------------
-- Process --
-------------
function Process (Nod : Node_Id) return Traverse_Result is
begin
-- Procedure call
if Nkind (Nod) = N_Procedure_Call_Statement then
-- Case of one of the detected recursive calls
if Is_Entity_Name (Name (Nod))
and then Has_Recursive_Call (Entity (Name (Nod)))
and then Entity (Name (Nod)) = Spec
then
Append_Elmt (Nod, Call_List);
return Skip;
-- Any other procedure call may have side effects
else
return Abandon;
end if;
-- A call to a pure function can always be ignored
elsif Nkind (Nod) = N_Function_Call
and then Is_Entity_Name (Name (Nod))
and then Is_Pure (Entity (Name (Nod)))
then
return Skip;
-- Case of an identifier reference
elsif Nkind (Nod) = N_Identifier then
Ent := Entity (Nod);
-- If no entity, then ignore the reference
-- Not clear why this can happen. To investigate, remove this
-- test and look at the crash that occurs here in 3401-004 ???
if No (Ent) then
return Skip;
-- Ignore entities with no Scope, again not clear how this
-- can happen, to investigate, look at 4108-008 ???
elsif No (Scope (Ent)) then
return Skip;
-- Ignore the reference if not to a more global object
elsif Scope_Depth (Scope (Ent)) >= Scop then
return Skip;
-- References to types, exceptions and constants are always OK
elsif Is_Type (Ent)
or else Ekind (Ent) = E_Exception
or else Ekind (Ent) = E_Constant
then
return Skip;
-- If other than a non-volatile scalar variable, we have some
-- kind of global reference (e.g. to a function) that we cannot
-- deal with so we forget the attempt.
elsif Ekind (Ent) /= E_Variable
or else not Is_Scalar_Type (Etype (Ent))
or else Treat_As_Volatile (Ent)
then
return Abandon;
-- Otherwise we have a reference to a global scalar
else
-- Loop through global entities already detected
Elm := First_Elmt (Var_List);
loop
-- If not detected before, record this new global reference
if No (Elm) then
Count_Vars := Count_Vars + 1;
if Count_Vars <= Max_Vars then
Append_Elmt (Entity (Nod), Var_List);
else
return Abandon;
end if;
exit;
-- If recorded before, ignore
elsif Node (Elm) = Entity (Nod) then
return Skip;
-- Otherwise keep looking
else
Next_Elmt (Elm);
end if;
end loop;
return Skip;
end if;
-- For all other node kinds, recursively visit syntactic children
else
return OK;
end if;
end Process;
function Traverse_Body is new Traverse_Func (Process);
-- Start of processing for Detect_Infinite_Recursion
begin
-- Do not attempt detection in No_Implicit_Conditional mode, since we
-- won't be able to generate the code to handle the recursion in any
-- case.
if Restriction_Active (No_Implicit_Conditionals) then
return;
end if;
-- Otherwise do traversal and quit if we get abandon signal
if Traverse_Body (N) = Abandon then
return;
-- We must have a call, since Has_Recursive_Call was set. If not just
-- ignore (this is only an error check, so if we have a funny situation,
-- due to bugs or errors, we do not want to bomb).
elsif Is_Empty_Elmt_List (Call_List) then
return;
end if;
-- Here is the case where we detect recursion at compile time
-- Push our current scope for analyzing the declarations and code that
-- we will insert for the checking.
Push_Scope (Spec);
-- This loop builds temporary variables for each of the referenced
-- globals, so that at the end of the loop the list Shad_List contains
-- these temporaries in one-to-one correspondence with the elements in
-- Var_List.
Last := Empty;
Elm := First_Elmt (Var_List);
while Present (Elm) loop
Var := Node (Elm);
Ent := Make_Temporary (Loc, 'S');
Append_Elmt (Ent, Shad_List);
-- Insert a declaration for this temporary at the start of the
-- declarations for the procedure. The temporaries are declared as
-- constant objects initialized to the current values of the
-- corresponding temporaries.
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Ent,
Object_Definition => New_Occurrence_Of (Etype (Var), Loc),
Constant_Present => True,
Expression => New_Occurrence_Of (Var, Loc));
if No (Last) then
Prepend (Decl, Declarations (N));
else
Insert_After (Last, Decl);
end if;
Last := Decl;
Analyze (Decl);
Next_Elmt (Elm);
end loop;
-- Loop through calls
Call := First_Elmt (Call_List);
while Present (Call) loop
-- Build a predicate expression of the form
-- True
-- and then global1 = temp1
-- and then global2 = temp2
-- ...
-- This predicate determines if any of the global values
-- referenced by the procedure have changed since the
-- current call, if not an infinite recursion is assured.
Test := New_Occurrence_Of (Standard_True, Loc);
Elm1 := First_Elmt (Var_List);
Elm2 := First_Elmt (Shad_List);
while Present (Elm1) loop
Test :=
Make_And_Then (Loc,
Left_Opnd => Test,
Right_Opnd =>
Make_Op_Eq (Loc,
Left_Opnd => New_Occurrence_Of (Node (Elm1), Loc),
Right_Opnd => New_Occurrence_Of (Node (Elm2), Loc)));
Next_Elmt (Elm1);
Next_Elmt (Elm2);
end loop;
-- Now we replace the call with the sequence
-- if no-changes (see above) then
-- raise Storage_Error;
-- else
-- original-call
-- end if;
Rewrite (Node (Call),
Make_If_Statement (Loc,
Condition => Test,
Then_Statements => New_List (
Make_Raise_Storage_Error (Loc,
Reason => SE_Infinite_Recursion)),
Else_Statements => New_List (
Relocate_Node (Node (Call)))));
Analyze (Node (Call));
Next_Elmt (Call);
end loop;
-- Remove temporary scope stack entry used for analysis
Pop_Scope;
end Detect_Infinite_Recursion;
--------------------
-- Expand_Actuals --
--------------------
procedure Expand_Actuals
(N : Node_Id;
Subp : Entity_Id;
Post_Call : out List_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Actual : Node_Id;
Formal : Entity_Id;
N_Node : Node_Id;
E_Actual : Entity_Id;
E_Formal : Entity_Id;
procedure Add_Call_By_Copy_Code;
-- For cases where the parameter must be passed by copy, this routine
-- generates a temporary variable into which the actual is copied and
-- then passes this as the parameter. For an OUT or IN OUT parameter,
-- an assignment is also generated to copy the result back. The call
-- also takes care of any constraint checks required for the type
-- conversion case (on both the way in and the way out).
procedure Add_Simple_Call_By_Copy_Code (Force : Boolean);
-- This is similar to the above, but is used in cases where we know
-- that all that is needed is to simply create a temporary and copy
-- the value in and out of the temporary. If Force is True, then the
-- procedure may disregard legality considerations.
-- ??? We need to do the copy for a bit-packed array because this is
-- where the rewriting into a mask-and-shift sequence is done. But of
-- course this may break the program if it expects bits to be really
-- passed by reference. That's what we have done historically though.
procedure Add_Validation_Call_By_Copy_Code (Act : Node_Id);
-- Perform copy-back for actual parameter Act which denotes a validation
-- variable.
procedure Check_Fortran_Logical;
-- A value of type Logical that is passed through a formal parameter
-- must be normalized because .TRUE. usually does not have the same
-- representation as True. We assume that .FALSE. = False = 0.
-- What about functions that return a logical type ???
function Is_Legal_Copy return Boolean;
-- Check that an actual can be copied before generating the temporary
-- to be used in the call. If the formal is of a by_reference type or
-- is aliased, then the program is illegal (this can only happen in
-- the presence of representation clauses that force a misalignment)
-- If the formal is a by_reference parameter imposed by a DEC pragma,
-- emit a warning that this might lead to unaligned arguments.
function Make_Var (Actual : Node_Id) return Entity_Id;
-- Returns an entity that refers to the given actual parameter, Actual
-- (not including any type conversion). If Actual is an entity name,
-- then this entity is returned unchanged, otherwise a renaming is
-- created to provide an entity for the actual.
procedure Reset_Packed_Prefix;
-- The expansion of a packed array component reference is delayed in
-- the context of a call. Now we need to complete the expansion, so we
-- unmark the analyzed bits in all prefixes.
function Requires_Atomic_Or_Volatile_Copy return Boolean;
-- Returns whether a copy is required as per RM C.6(19) and gives a
-- warning in this case.
---------------------------
-- Add_Call_By_Copy_Code --
---------------------------
procedure Add_Call_By_Copy_Code is
Crep : Boolean;
Expr : Node_Id;
F_Typ : Entity_Id := Etype (Formal);
Indic : Node_Id;
Init : Node_Id;
Temp : Entity_Id;
V_Typ : Entity_Id;
Var : Entity_Id;
begin
if not Is_Legal_Copy then
return;
end if;
Temp := Make_Temporary (Loc, 'T', Actual);
-- Handle formals whose type comes from the limited view
if From_Limited_With (F_Typ)
and then Has_Non_Limited_View (F_Typ)
then
F_Typ := Non_Limited_View (F_Typ);
end if;
-- Use formal type for temp, unless formal type is an unconstrained
-- array, in which case we don't have to worry about bounds checks,
-- and we use the actual type, since that has appropriate bounds.
if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
Indic := New_Occurrence_Of (Etype (Actual), Loc);
else
Indic := New_Occurrence_Of (F_Typ, Loc);
end if;
-- The new code will be properly analyzed below and the setting of
-- the Do_Range_Check flag recomputed so remove the obsolete one.
Set_Do_Range_Check (Actual, False);
if Nkind (Actual) = N_Type_Conversion then
Set_Do_Range_Check (Expression (Actual), False);
V_Typ := Etype (Expression (Actual));
-- If the formal is an (in-)out parameter, capture the name
-- of the variable in order to build the post-call assignment.
Var := Make_Var (Expression (Actual));
Crep := not Has_Compatible_Representation
(Target_Type => F_Typ,
Operand_Type => Etype (Expression (Actual)));
else
V_Typ := Etype (Actual);
Var := Make_Var (Actual);
Crep := False;
end if;
-- Setup initialization for case of in out parameter, or an out
-- parameter where the formal is an unconstrained array (in the
-- latter case, we have to pass in an object with bounds).
-- If this is an out parameter, the initial copy is wasteful, so as
-- an optimization for the one-dimensional case we extract the
-- bounds of the actual and build an uninitialized temporary of the
-- right size.
-- If the formal is an out parameter with discriminants, the
-- discriminants must be captured even if the rest of the object
-- is in principle uninitialized, because the discriminants may
-- be read by the called subprogram.
if Ekind (Formal) = E_In_Out_Parameter
or else (Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ))
or else Has_Discriminants (F_Typ)
then
if Nkind (Actual) = N_Type_Conversion then
if Conversion_OK (Actual) then
Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
else
Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
end if;
elsif Ekind (Formal) = E_Out_Parameter
and then Is_Array_Type (F_Typ)
and then Number_Dimensions (F_Typ) = 1
and then not Has_Non_Null_Base_Init_Proc (F_Typ)
then
-- Actual is a one-dimensional array or slice, and the type
-- requires no initialization. Create a temporary of the
-- right size, but do not copy actual into it (optimization).
Init := Empty;
Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (F_Typ, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => New_List (
Make_Range (Loc,
Low_Bound =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Var, Loc),
Attribute_Name => Name_First),
High_Bound =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Var, Loc),
Attribute_Name => Name_Last)))));
else
Init := New_Occurrence_Of (Var, Loc);
end if;
-- An initialization is created for packed conversions as
-- actuals for out parameters to enable Make_Object_Declaration
-- to determine the proper subtype for N_Node. Note that this
-- is wasteful because the extra copying on the call side is
-- not required for such out parameters. ???
elsif Ekind (Formal) = E_Out_Parameter
and then Nkind (Actual) = N_Type_Conversion
and then (Is_Bit_Packed_Array (F_Typ)
or else
Is_Bit_Packed_Array (Etype (Expression (Actual))))
then
if Conversion_OK (Actual) then
Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
else
Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
end if;
elsif Ekind (Formal) = E_In_Parameter then
-- Handle the case in which the actual is a type conversion
if Nkind (Actual) = N_Type_Conversion then
if Conversion_OK (Actual) then
Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
else
Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
end if;
else
Init := New_Occurrence_Of (Var, Loc);
end if;
-- Access types are passed in without checks, but if a copy-back is
-- required for a null-excluding check on an in-out or out parameter,
-- then the initial value is that of the actual.
elsif Is_Access_Type (E_Formal)
and then Can_Never_Be_Null (Etype (Actual))
and then not Can_Never_Be_Null (E_Formal)
then
Init := New_Occurrence_Of (Var, Loc);
-- View conversions when the formal type has the Default_Value aspect
-- require passing in the value of the conversion's operand. The type
-- of that operand also has Default_Value, as required by AI12-0074
-- (RM 6.4.1(5.3/4)). The subtype denoted by the subtype_indication
-- is changed to the base type of the formal subtype, to ensure that
-- the actual's value can be assigned without a constraint check
-- (note that no check is done on passing to an out parameter). Also
-- note that the two types necessarily share the same ancestor type,
-- as required by 6.4.1(5.2/4), so underlying base types will match.
elsif Ekind (Formal) = E_Out_Parameter
and then Is_Scalar_Type (Etype (F_Typ))
and then Nkind (Actual) = N_Type_Conversion
and then Present (Default_Aspect_Value (Etype (F_Typ)))
then
Indic := New_Occurrence_Of (Base_Type (F_Typ), Loc);
Init := Convert_To
(Base_Type (F_Typ), New_Occurrence_Of (Var, Loc));
else
Init := Empty;
end if;
N_Node :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition => Indic,
Expression => Init);
Set_Assignment_OK (N_Node);
Insert_Action (N, N_Node);
-- Now, normally the deal here is that we use the defining
-- identifier created by that object declaration. There is
-- one exception to this. In the change of representation case
-- the above declaration will end up looking like:
-- temp : type := identifier;
-- And in this case we might as well use the identifier directly
-- and eliminate the temporary. Note that the analysis of the
-- declaration was not a waste of time in that case, since it is
-- what generated the necessary change of representation code. If
-- the change of representation introduced additional code, as in
-- a fixed-integer conversion, the expression is not an identifier
-- and must be kept.
if Crep
and then Present (Expression (N_Node))
and then Is_Entity_Name (Expression (N_Node))
then
Temp := Entity (Expression (N_Node));
Rewrite (N_Node, Make_Null_Statement (Loc));
end if;
-- For IN parameter, all we do is to replace the actual
if Ekind (Formal) = E_In_Parameter then
Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
Analyze (Actual);
-- Processing for OUT or IN OUT parameter
else
-- Kill current value indications for the temporary variable we
-- created, since we just passed it as an OUT parameter.
Kill_Current_Values (Temp);
Set_Is_Known_Valid (Temp, False);
Set_Is_True_Constant (Temp, False);
-- If type conversion, use reverse conversion on exit
if Nkind (Actual) = N_Type_Conversion then
if Conversion_OK (Actual) then
Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
else
Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
end if;
else
Expr := New_Occurrence_Of (Temp, Loc);
end if;
Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
Analyze (Actual);
-- If the actual is a conversion of a packed reference, it may
-- already have been expanded by Remove_Side_Effects, and the
-- resulting variable is a temporary which does not designate
-- the proper out-parameter, which may not be addressable. In
-- that case, generate an assignment to the original expression
-- (before expansion of the packed reference) so that the proper
-- expansion of assignment to a packed component can take place.
declare
Obj : Node_Id;
Lhs : Node_Id;
begin
if Is_Renaming_Of_Object (Var)
and then Nkind (Renamed_Object (Var)) = N_Selected_Component
and then Nkind (Original_Node (Prefix (Renamed_Object (Var))))
= N_Indexed_Component
and then
Has_Non_Standard_Rep (Etype (Prefix (Renamed_Object (Var))))
then
Obj := Renamed_Object (Var);
Lhs :=
Make_Selected_Component (Loc,
Prefix =>
New_Copy_Tree (Original_Node (Prefix (Obj))),
Selector_Name => New_Copy (Selector_Name (Obj)));
Reset_Analyzed_Flags (Lhs);
else
Lhs := New_Occurrence_Of (Var, Loc);
end if;
Set_Assignment_OK (Lhs);
if Is_Access_Type (E_Formal)
and then Is_Entity_Name (Lhs)
and then
Present (Effective_Extra_Accessibility (Entity (Lhs)))
and then not No_Dynamic_Accessibility_Checks_Enabled (Lhs)
then
-- Copyback target is an Ada 2012 stand-alone object of an
-- anonymous access type.
pragma Assert (Ada_Version >= Ada_2012);
Apply_Accessibility_Check (Lhs, E_Formal, N);
Append_To (Post_Call,
Make_Assignment_Statement (Loc,
Name => Lhs,
Expression => Expr));
-- We would like to somehow suppress generation of the
-- extra_accessibility assignment generated by the expansion
-- of the above assignment statement. It's not a correctness
-- issue because the following assignment renders it dead,
-- but generating back-to-back assignments to the same
-- target is undesirable. ???
Append_To (Post_Call,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (
Effective_Extra_Accessibility (Entity (Lhs)), Loc),
Expression => Make_Integer_Literal (Loc,
Type_Access_Level (E_Formal))));
else
if Is_Access_Type (E_Formal)
and then Can_Never_Be_Null (Etype (Actual))
and then not Can_Never_Be_Null (E_Formal)
then
Append_To (Post_Call,
Make_Raise_Constraint_Error (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd => New_Occurrence_Of (Temp, Loc),
Right_Opnd => Make_Null (Loc)),
Reason => CE_Access_Check_Failed));
end if;
Append_To (Post_Call,
Make_Assignment_Statement (Loc,
Name => Lhs,
Expression => Expr));
end if;
end;
end if;
end Add_Call_By_Copy_Code;
----------------------------------
-- Add_Simple_Call_By_Copy_Code --
----------------------------------
procedure Add_Simple_Call_By_Copy_Code (Force : Boolean) is
Decl : Node_Id;
F_Typ : Entity_Id := Etype (Formal);
Incod : Node_Id;
Indic : Node_Id;
Lhs : Node_Id;
Outcod : Node_Id;
Rhs : Node_Id;
Temp : Entity_Id;
begin
-- Unless forced not to, check the legality of the copy operation
if not Force and then not Is_Legal_Copy then
return;
end if;
-- Handle formals whose type comes from the limited view
if From_Limited_With (F_Typ)
and then Has_Non_Limited_View (F_Typ)
then
F_Typ := Non_Limited_View (F_Typ);
end if;
-- Use formal type for temp, unless formal type is an unconstrained
-- array, in which case we don't have to worry about bounds checks,
-- and we use the actual type, since that has appropriate bounds.
if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
Indic := New_Occurrence_Of (Etype (Actual), Loc);
else
Indic := New_Occurrence_Of (F_Typ, Loc);
end if;
-- Prepare to generate code
Reset_Packed_Prefix;
Temp := Make_Temporary (Loc, 'T', Actual);
Incod := Relocate_Node (Actual);
Outcod := New_Copy_Tree (Incod);
-- Generate declaration of temporary variable, initializing it
-- with the input parameter unless we have an OUT formal or
-- this is an initialization call.
-- If the formal is an out parameter with discriminants, the
-- discriminants must be captured even if the rest of the object
-- is in principle uninitialized, because the discriminants may
-- be read by the called subprogram.
if Ekind (Formal) = E_Out_Parameter then
Incod := Empty;
if Has_Discriminants (F_Typ) then
Indic := New_Occurrence_Of (Etype (Actual), Loc);
end if;
elsif Inside_Init_Proc then
-- Could use a comment here to match comment below ???
if Nkind (Actual) /= N_Selected_Component
or else
not Has_Discriminant_Dependent_Constraint
(Entity (Selector_Name (Actual)))
then
Incod := Empty;
-- Otherwise, keep the component in order to generate the proper
-- actual subtype, that depends on enclosing discriminants.
else
null;
end if;
end if;
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition => Indic,
Expression => Incod);
if Inside_Init_Proc
and then No (Incod)
then
-- If the call is to initialize a component of a composite type,
-- and the component does not depend on discriminants, use the
-- actual type of the component. This is required in case the
-- component is constrained, because in general the formal of the
-- initialization procedure will be unconstrained. Note that if
-- the component being initialized is constrained by an enclosing
-- discriminant, the presence of the initialization in the
-- declaration will generate an expression for the actual subtype.
Set_No_Initialization (Decl);
Set_Object_Definition (Decl,
New_Occurrence_Of (Etype (Actual), Loc));
end if;
Insert_Action (N, Decl);
-- The actual is simply a reference to the temporary
Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
-- Generate copy out if OUT or IN OUT parameter
if Ekind (Formal) /= E_In_Parameter then
Lhs := Outcod;
Rhs := New_Occurrence_Of (Temp, Loc);
Set_Is_True_Constant (Temp, False);
-- Deal with conversion
if Nkind (Lhs) = N_Type_Conversion then
Lhs := Expression (Lhs);
Rhs := Convert_To (Etype (Actual), Rhs);
end if;
Append_To (Post_Call,
Make_Assignment_Statement (Loc,
Name => Lhs,
Expression => Rhs));
Set_Assignment_OK (Name (Last (Post_Call)));
end if;
end Add_Simple_Call_By_Copy_Code;
--------------------------------------
-- Add_Validation_Call_By_Copy_Code --
--------------------------------------
procedure Add_Validation_Call_By_Copy_Code (Act : Node_Id) is
Expr : Node_Id;
Obj : Node_Id;
Obj_Typ : Entity_Id;
Var : constant Node_Id := Unqual_Conv (Act);
Var_Id : Entity_Id;
begin
-- Generate range check if required
if Do_Range_Check (Actual) then
Generate_Range_Check (Actual, E_Formal, CE_Range_Check_Failed);
end if;
-- If there is a type conversion in the actual, it will be reinstated
-- below, the new instance will be properly analyzed and the setting
-- of the Do_Range_Check flag recomputed so remove the obsolete one.
if Nkind (Actual) = N_Type_Conversion then
Set_Do_Range_Check (Expression (Actual), False);
end if;
-- Copy the value of the validation variable back into the object
-- being validated.
if Is_Entity_Name (Var) then
Var_Id := Entity (Var);
Obj := Validated_Object (Var_Id);
Obj_Typ := Etype (Obj);
Expr := New_Occurrence_Of (Var_Id, Loc);
-- A type conversion is needed when the validation variable and
-- the validated object carry different types. This case occurs
-- when the actual is qualified in some fashion.
-- Common:
-- subtype Int is Integer range ...;
-- procedure Call (Val : in out Integer);
-- Original:
-- Object : Int;
-- Call (Integer (Object));
-- Expanded:
-- Object : Int;
-- Var : Integer := Object; -- conversion to base type
-- if not Var'Valid then -- validity check
-- Call (Var); -- modify Var
-- Object := Int (Var); -- conversion to subtype
if Etype (Var_Id) /= Obj_Typ then
Expr :=
Make_Type_Conversion (Loc,
Subtype_Mark => New_Occurrence_Of (Obj_Typ, Loc),
Expression => Expr);
end if;
-- Generate:
-- Object := Var;
-- <or>
-- Object := Object_Type (Var);
Append_To (Post_Call,
Make_Assignment_Statement (Loc,
Name => Obj,
Expression => Expr));
-- If the flow reaches this point, then this routine was invoked with
-- an actual which does not denote a validation variable.
else
pragma Assert (False);
null;
end if;
end Add_Validation_Call_By_Copy_Code;
---------------------------
-- Check_Fortran_Logical --
---------------------------
procedure Check_Fortran_Logical is
Logical : constant Entity_Id := Etype (Formal);
Var : Entity_Id;
-- Note: this is very incomplete, e.g. it does not handle arrays
-- of logical values. This is really not the right approach at all???)
begin
if Convention (Subp) = Convention_Fortran
and then Root_Type (Etype (Formal)) = Standard_Boolean
and then Ekind (Formal) /= E_In_Parameter
then
Var := Make_Var (Actual);
Append_To (Post_Call,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Var, Loc),
Expression =>
Unchecked_Convert_To (
Logical,
Make_Op_Ne (Loc,
Left_Opnd => New_Occurrence_Of (Var, Loc),
Right_Opnd =>
Unchecked_Convert_To (
Logical,
New_Occurrence_Of (Standard_False, Loc))))));
end if;
end Check_Fortran_Logical;
-------------------
-- Is_Legal_Copy --
-------------------
function Is_Legal_Copy return Boolean is
begin
-- An attempt to copy a value of such a type can only occur if
-- representation clauses give the actual a misaligned address.
if Is_By_Reference_Type (Etype (Formal))
or else Is_Aliased (Formal)
or else (Mechanism (Formal) = By_Reference
and then not Has_Foreign_Convention (Subp))
then
-- The actual may in fact be properly aligned but there is not
-- enough front-end information to determine this. In that case
-- gigi will emit an error or a warning if a copy is not legal,
-- or generate the proper code.
return False;
-- For users of Starlet, we assume that the specification of by-
-- reference mechanism is mandatory. This may lead to unaligned
-- objects but at least for DEC legacy code it is known to work.
-- The warning will alert users of this code that a problem may
-- be lurking.
elsif Mechanism (Formal) = By_Reference
and then Ekind (Scope (Formal)) = E_Procedure
and then Is_Valued_Procedure (Scope (Formal))
then
Error_Msg_N
("by_reference actual may be misaligned??", Actual);
return False;
else
return True;
end if;
end Is_Legal_Copy;
--------------
-- Make_Var --
--------------
function Make_Var (Actual : Node_Id) return Entity_Id is
Var : Entity_Id;
begin
if Is_Entity_Name (Actual) then
return Entity (Actual);
else
Var := Make_Temporary (Loc, 'T', Actual);
N_Node :=
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Var,
Subtype_Mark =>
New_Occurrence_Of (Etype (Actual), Loc),
Name => Relocate_Node (Actual));
Insert_Action (N, N_Node);
return Var;
end if;
end Make_Var;
-------------------------
-- Reset_Packed_Prefix --
-------------------------
procedure Reset_Packed_Prefix is
Pfx : Node_Id := Actual;
begin
loop
Set_Analyzed (Pfx, False);
exit when
Nkind (Pfx) not in N_Selected_Component | N_Indexed_Component;
Pfx := Prefix (Pfx);
end loop;
end Reset_Packed_Prefix;
----------------------------------------
-- Requires_Atomic_Or_Volatile_Copy --
----------------------------------------
function Requires_Atomic_Or_Volatile_Copy return Boolean is
begin
-- If the formal is already passed by copy, no need to do anything
if Is_By_Copy_Type (E_Formal) then
return False;
end if;
-- There is no requirement inside initialization procedures and this
-- would generate copies for atomic or volatile composite components.
if Inside_Init_Proc then
return False;
end if;
-- Check for atomicity mismatch
if Is_Atomic_Object (Actual) and then not Is_Atomic (E_Formal)
then
if Comes_From_Source (N) then
Error_Msg_N
("??atomic actual passed by copy (RM C.6(19))", Actual);
end if;
return True;
end if;
-- Check for volatility mismatch
if Is_Volatile_Object_Ref (Actual) and then not Is_Volatile (E_Formal)
then
if Comes_From_Source (N) then
Error_Msg_N
("??volatile actual passed by copy (RM C.6(19))", Actual);
end if;
return True;
end if;
return False;
end Requires_Atomic_Or_Volatile_Copy;
-- Start of processing for Expand_Actuals
begin
Post_Call := New_List;
Formal := First_Formal (Subp);
Actual := First_Actual (N);
while Present (Formal) loop
E_Formal := Etype (Formal);
E_Actual := Etype (Actual);
-- Handle formals whose type comes from the limited view
if From_Limited_With (E_Formal)
and then Has_Non_Limited_View (E_Formal)
then
E_Formal := Non_Limited_View (E_Formal);
end if;
if Is_Scalar_Type (E_Formal)
or else Nkind (Actual) = N_Slice
then
Check_Fortran_Logical;
-- RM 6.4.1 (11)
elsif Ekind (Formal) /= E_Out_Parameter then
-- The unusual case of the current instance of a protected type
-- requires special handling. This can only occur in the context
-- of a call within the body of a protected operation.
if Is_Entity_Name (Actual)
and then Ekind (Entity (Actual)) = E_Protected_Type
and then In_Open_Scopes (Entity (Actual))
then
if Scope (Subp) /= Entity (Actual) then
Error_Msg_N
("operation outside protected type may not "
& "call back its protected operations??", Actual);
end if;
Rewrite (Actual,
Expand_Protected_Object_Reference (N, Entity (Actual)));
end if;
-- Ada 2005 (AI-318-02): If the actual parameter is a call to a
-- build-in-place function, then a temporary return object needs
-- to be created and access to it must be passed to the function
-- (and ensure that we have an activation chain defined for tasks
-- and a Master variable).
-- Currently we limit such functions to those with inherently
-- limited result subtypes, but eventually we plan to expand the
-- functions that are treated as build-in-place to include other
-- composite result types.
-- But do not do it here for intrinsic subprograms since this will
-- be done properly after the subprogram is expanded.
if Is_Intrinsic_Subprogram (Subp) then
null;
elsif Is_Build_In_Place_Function_Call (Actual) then
Build_Activation_Chain_Entity (N);
Build_Master_Entity (Etype (Actual));
Make_Build_In_Place_Call_In_Anonymous_Context (Actual);
-- Ada 2005 (AI-318-02): Specialization of the previous case for
-- actuals containing build-in-place function calls whose returned
-- object covers interface types.
elsif Present (Unqual_BIP_Iface_Function_Call (Actual)) then
Build_Activation_Chain_Entity (N);
Build_Master_Entity (Etype (Actual));
Make_Build_In_Place_Iface_Call_In_Anonymous_Context (Actual);
end if;
Apply_Constraint_Check (Actual, E_Formal);
-- Out parameter case. No constraint checks on access type
-- RM 6.4.1 (13), but on return a null-excluding check may be
-- required (see below).
elsif Is_Access_Type (E_Formal) then
null;
-- RM 6.4.1 (14)
elsif Has_Discriminants (Base_Type (E_Formal))
or else Has_Non_Null_Base_Init_Proc (E_Formal)
then
Apply_Constraint_Check (Actual, E_Formal);
-- RM 6.4.1 (15)
else
Apply_Constraint_Check (Actual, Base_Type (E_Formal));
end if;
-- Processing for IN-OUT and OUT parameters
if Ekind (Formal) /= E_In_Parameter then
-- For type conversions of arrays, apply length/range checks
if Is_Array_Type (E_Formal)
and then Nkind (Actual) = N_Type_Conversion
then
if Is_Constrained (E_Formal) then
Apply_Length_Check (Expression (Actual), E_Formal);
else
Apply_Range_Check (Expression (Actual), E_Formal);
end if;
end if;
-- The actual denotes a variable which captures the value of an
-- object for validation purposes. Add a copy-back to reflect any
-- potential changes in value back into the original object.
-- Var : ... := Object;
-- if not Var'Valid then -- validity check
-- Call (Var); -- modify var
-- Object := Var; -- update Object
-- This case is given higher priority because the subsequent check
-- for type conversion may add an extra copy of the variable and
-- prevent proper value propagation back in the original object.
if Is_Validation_Variable_Reference (Actual) then
Add_Validation_Call_By_Copy_Code (Actual);
-- If argument is a type conversion for a type that is passed by
-- copy, then we must pass the parameter by copy.
elsif Nkind (Actual) = N_Type_Conversion
and then
(Is_Elementary_Type (E_Formal)
or else Is_Bit_Packed_Array (Etype (Formal))
or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
-- Also pass by copy if change of representation
or else not Has_Compatible_Representation
(Target_Type => Etype (Formal),
Operand_Type => Etype (Expression (Actual))))
then
Add_Call_By_Copy_Code;
-- References to components of bit-packed arrays are expanded
-- at this point, rather than at the point of analysis of the
-- actuals, to handle the expansion of the assignment to
-- [in] out parameters.
elsif Is_Ref_To_Bit_Packed_Array (Actual) then
Add_Simple_Call_By_Copy_Code (Force => True);
-- If a nonscalar actual is possibly bit-aligned, we need a copy
-- because the back-end cannot cope with such objects. In other
-- cases where alignment forces a copy, the back-end generates
-- it properly. It should not be generated unconditionally in the
-- front-end because it does not know precisely the alignment
-- requirements of the target, and makes too conservative an
-- estimate, leading to superfluous copies or spurious errors
-- on by-reference parameters.
elsif Nkind (Actual) = N_Selected_Component
and then
Component_May_Be_Bit_Aligned (Entity (Selector_Name (Actual)))
and then not Represented_As_Scalar (Etype (Formal))
then
Add_Simple_Call_By_Copy_Code (Force => False);
-- References to slices of bit-packed arrays are expanded
elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
Add_Call_By_Copy_Code;
-- References to possibly unaligned slices of arrays are expanded
elsif Is_Possibly_Unaligned_Slice (Actual) then
Add_Call_By_Copy_Code;
-- Deal with access types where the actual subtype and the
-- formal subtype are not the same, requiring a check.
-- It is necessary to exclude tagged types because of "downward
-- conversion" errors, but null-excluding checks on return may be
-- required.
elsif Is_Access_Type (E_Formal)
and then not Is_Tagged_Type (Designated_Type (E_Formal))
and then (not Same_Type (E_Formal, E_Actual)
or else (Can_Never_Be_Null (E_Actual)
and then not Can_Never_Be_Null (E_Formal)))
then
Add_Call_By_Copy_Code;
-- We may need to force a copy because of atomicity or volatility
-- considerations.
elsif Requires_Atomic_Or_Volatile_Copy then
Add_Call_By_Copy_Code;
-- Add call-by-copy code for the case of scalar out parameters
-- when it is not known at compile time that the subtype of the
-- formal is a subrange of the subtype of the actual (or vice
-- versa for in out parameters), in order to get range checks
-- on such actuals. (Maybe this case should be handled earlier
-- in the if statement???)
elsif Is_Scalar_Type (E_Formal)
and then
(not In_Subrange_Of (E_Formal, E_Actual)
or else
(Ekind (Formal) = E_In_Out_Parameter
and then not In_Subrange_Of (E_Actual, E_Formal)))
then
Add_Call_By_Copy_Code;
end if;
-- RM 3.2.4 (23/3): A predicate is checked on in-out and out
-- by-reference parameters on exit from the call. If the actual
-- is a derived type and the operation is inherited, the body
-- of the operation will not contain a call to the predicate
-- function, so it must be done explicitly after the call. Ditto
-- if the actual is an entity of a predicated subtype.
-- The rule refers to by-reference types, but a check is needed
-- for by-copy types as well. That check is subsumed by the rule
-- for subtype conversion on assignment, but we can generate the
-- required check now.
-- Note also that Subp may be either a subprogram entity for
-- direct calls, or a type entity for indirect calls, which must
-- be handled separately because the name does not denote an
-- overloadable entity.
By_Ref_Predicate_Check : declare
Aund : constant Entity_Id := Underlying_Type (E_Actual);
Atyp : Entity_Id;
begin
if No (Aund) then
Atyp := E_Actual;
else
Atyp := Aund;
end if;
if Predicate_Enabled (Atyp)
-- Skip predicate checks for special cases
and then Predicate_Tests_On_Arguments (Subp)
then
Append_To (Post_Call,
Make_Predicate_Check (Atyp, Actual));
end if;
end By_Ref_Predicate_Check;
-- Processing for IN parameters
else
-- Generate range check if required
if Do_Range_Check (Actual) then
Generate_Range_Check (Actual, E_Formal, CE_Range_Check_Failed);
end if;
-- For IN parameters in the bit-packed array case, we expand an
-- indexed component (the circuit in Exp_Ch4 deliberately left
-- indexed components appearing as actuals untouched, so that
-- the special processing above for the OUT and IN OUT cases
-- could be performed. We could make the test in Exp_Ch4 more
-- complex and have it detect the parameter mode, but it is
-- easier simply to handle all cases here.)
if Nkind (Actual) = N_Indexed_Component
and then Is_Bit_Packed_Array (Etype (Prefix (Actual)))
then
Reset_Packed_Prefix;
Expand_Packed_Element_Reference (Actual);
-- If we have a reference to a bit-packed array, we copy it, since
-- the actual must be byte aligned.
-- Is this really necessary in all cases???
elsif Is_Ref_To_Bit_Packed_Array (Actual) then
Add_Simple_Call_By_Copy_Code (Force => True);
-- If we have a C++ constructor call, we need to create the object
elsif Is_CPP_Constructor_Call (Actual) then
Add_Simple_Call_By_Copy_Code (Force => True);
-- If a nonscalar actual is possibly unaligned, we need a copy
elsif Is_Possibly_Unaligned_Object (Actual)
and then not Represented_As_Scalar (Etype (Formal))
then
Add_Simple_Call_By_Copy_Code (Force => False);
-- Similarly, we have to expand slices of packed arrays here
-- because the result must be byte aligned.
elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
Add_Call_By_Copy_Code;
-- Only processing remaining is to pass by copy if this is a
-- reference to a possibly unaligned slice, since the caller
-- expects an appropriately aligned argument.
elsif Is_Possibly_Unaligned_Slice (Actual) then
Add_Call_By_Copy_Code;
-- We may need to force a copy because of atomicity or volatility
-- considerations.
elsif Requires_Atomic_Or_Volatile_Copy then
Add_Call_By_Copy_Code;
-- An unusual case: a current instance of an enclosing task can be
-- an actual, and must be replaced by a reference to self.
elsif Is_Entity_Name (Actual)
and then Is_Task_Type (Entity (Actual))
then
if In_Open_Scopes (Entity (Actual)) then
Rewrite (Actual,
(Make_Function_Call (Loc,
Name => New_Occurrence_Of (RTE (RE_Self), Loc))));
Analyze (Actual);
-- A task type cannot otherwise appear as an actual
else
raise Program_Error;
end if;
end if;
end if;
-- Type-invariant checks for in-out and out parameters, as well as
-- for in parameters of procedures (AI05-0289 and AI12-0044).
if Ekind (Formal) /= E_In_Parameter
or else Ekind (Subp) = E_Procedure
then
Caller_Side_Invariant_Checks : declare
function Is_Public_Subp return Boolean;
-- Check whether the subprogram being called is a visible
-- operation of the type of the actual. Used to determine
-- whether an invariant check must be generated on the
-- caller side.
---------------------
-- Is_Public_Subp --
---------------------
function Is_Public_Subp return Boolean is
Pack : constant Entity_Id := Scope (Subp);
Subp_Decl : Node_Id;
begin
if not Is_Subprogram (Subp) then
return False;
-- The operation may be inherited, or a primitive of the
-- root type.
elsif
Nkind (Parent (Subp)) in N_Private_Extension_Declaration
| N_Full_Type_Declaration
then
Subp_Decl := Parent (Subp);
else
Subp_Decl := Unit_Declaration_Node (Subp);
end if;
return Ekind (Pack) = E_Package
and then
List_Containing (Subp_Decl) =
Visible_Declarations
(Specification (Unit_Declaration_Node (Pack)));
end Is_Public_Subp;
-- Start of processing for Caller_Side_Invariant_Checks
begin
-- We generate caller-side invariant checks in two cases:
-- a) when calling an inherited operation, where there is an
-- implicit view conversion of the actual to the parent type.
-- b) When the conversion is explicit
-- We treat these cases separately because the required
-- conversion for a) is added later when expanding the call.
if Has_Invariants (Etype (Actual))
and then
Nkind (Parent (Etype (Actual)))
= N_Private_Extension_Declaration
then
if Comes_From_Source (N) and then Is_Public_Subp then
Append_To (Post_Call, Make_Invariant_Call (Actual));
end if;
elsif Nkind (Actual) = N_Type_Conversion
and then Has_Invariants (Etype (Expression (Actual)))
then
if Comes_From_Source (N) and then Is_Public_Subp then
Append_To
(Post_Call, Make_Invariant_Call (Expression (Actual)));
end if;
end if;
end Caller_Side_Invariant_Checks;
end if;
Next_Formal (Formal);
Next_Actual (Actual);
end loop;
end Expand_Actuals;
-----------------
-- Expand_Call --
-----------------
procedure Expand_Call (N : Node_Id) is
Post_Call : List_Id;
-- If this is an indirect call through an Access_To_Subprogram
-- with contract specifications, it is rewritten as a call to
-- the corresponding Access_Subprogram_Wrapper with the same
-- actuals, whose body contains a naked indirect call (which
-- itself must not be rewritten, to prevent infinite recursion).
Must_Rewrite_Indirect_Call : constant Boolean :=
Ada_Version >= Ada_2022
and then Nkind (Name (N)) = N_Explicit_Dereference
and then Ekind (Etype (Name (N))) = E_Subprogram_Type
and then Present
(Access_Subprogram_Wrapper (Etype (Name (N))));
begin
pragma Assert (Nkind (N) in N_Entry_Call_Statement
| N_Function_Call
| N_Procedure_Call_Statement);
-- Check that this is not the call in the body of the wrapper
if Must_Rewrite_Indirect_Call
and then (not Is_Overloadable (Current_Scope)
or else not Is_Access_Subprogram_Wrapper (Current_Scope))
then
declare
Loc : constant Source_Ptr := Sloc (N);
Wrapper : constant Entity_Id :=
Access_Subprogram_Wrapper (Etype (Name (N)));
Ptr : constant Node_Id := Prefix (Name (N));
Ptr_Type : constant Entity_Id := Etype (Ptr);
Typ : constant Entity_Id := Etype (N);
New_N : Node_Id;
Parms : List_Id := Parameter_Associations (N);
Ptr_Act : Node_Id;
begin
-- The last actual in the call is the pointer itself.
-- If the aspect is inherited, convert the pointer to the
-- parent type that specifies the contract.
-- If the original access_to_subprogram has defaults for
-- in_parameters, the call may include named associations, so
-- we create one for the pointer as well.
if Is_Derived_Type (Ptr_Type)
and then Ptr_Type /= Etype (Last_Formal (Wrapper))
then
Ptr_Act :=
Make_Type_Conversion (Loc,
New_Occurrence_Of
(Etype (Last_Formal (Wrapper)), Loc), Ptr);
else
Ptr_Act := Ptr;
end if;
-- Handle parameterless subprogram.
if No (Parms) then
Parms := New_List;
end if;
Append
(Make_Parameter_Association (Loc,
Selector_Name => Make_Identifier (Loc,
Chars (Last_Formal (Wrapper))),
Explicit_Actual_Parameter => Ptr_Act),
Parms);
if Nkind (N) = N_Procedure_Call_Statement then
New_N := Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Wrapper, Loc),
Parameter_Associations => Parms);
else
New_N := Make_Function_Call (Loc,
Name => New_Occurrence_Of (Wrapper, Loc),
Parameter_Associations => Parms);
end if;
Rewrite (N, New_N);
Analyze_And_Resolve (N, Typ);
end;
else
Expand_Call_Helper (N, Post_Call);
Insert_Post_Call_Actions (N, Post_Call);
end if;
end Expand_Call;
------------------------
-- Expand_Call_Helper --
------------------------
-- This procedure handles expansion of function calls and procedure call
-- statements (i.e. it serves as the body for Expand_N_Function_Call and
-- Expand_N_Procedure_Call_Statement). Processing for calls includes:
-- Replace call to Raise_Exception by Raise_Exception_Always if possible
-- Provide values of actuals for all formals in Extra_Formals list
-- Replace "call" to enumeration literal function by literal itself
-- Rewrite call to predefined operator as operator
-- Replace actuals to in-out parameters that are numeric conversions,
-- with explicit assignment to temporaries before and after the call.
-- Note that the list of actuals has been filled with default expressions
-- during semantic analysis of the call. Only the extra actuals required
-- for the 'Constrained attribute and for accessibility checks are added
-- at this point.
procedure Expand_Call_Helper (N : Node_Id; Post_Call : out List_Id) is
Loc : constant Source_Ptr := Sloc (N);
Call_Node : Node_Id := N;
Extra_Actuals : List_Id := No_List;
Prev : Node_Id := Empty;
procedure Add_Actual_Parameter (Insert_Param : Node_Id);
-- Adds one entry to the end of the actual parameter list. Used for
-- default parameters and for extra actuals (for Extra_Formals). The
-- argument is an N_Parameter_Association node.
procedure Add_Cond_Expression_Extra_Actual (Formal : Entity_Id);
-- Adds extra accessibility actuals in the case of a conditional
-- expression corresponding to Formal.
-- Note: Conditional expressions used as actuals for anonymous access
-- formals complicate the process of propagating extra accessibility
-- actuals and must be handled in a recursive fashion since they can
-- be embedded within each other.
procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
-- Adds an extra actual to the list of extra actuals. Expr is the
-- expression for the value of the actual, EF is the entity for the
-- extra formal.
procedure Add_View_Conversion_Invariants
(Formal : Entity_Id;
Actual : Node_Id);
-- Adds invariant checks for every intermediate type between the range
-- of a view converted argument to its ancestor (from parent to child).
function Can_Fold_Predicate_Call (P : Entity_Id) return Boolean;
-- Try to constant-fold a predicate check, which often enough is a
-- simple arithmetic expression that can be computed statically if
-- its argument is static. This cleans up the output of CCG, even
-- though useless predicate checks will be generally removed by
-- back-end optimizations.
procedure Check_Subprogram_Variant;
-- Emit a call to the internally generated procedure with checks for
-- aspect Subprogrgram_Variant, if present and enabled.
function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
-- Within an instance, a type derived from an untagged formal derived
-- type inherits from the original parent, not from the actual. The
-- current derivation mechanism has the derived type inherit from the
-- actual, which is only correct outside of the instance. If the
-- subprogram is inherited, we test for this particular case through a
-- convoluted tree traversal before setting the proper subprogram to be
-- called.
function In_Unfrozen_Instance (E : Entity_Id) return Boolean;
-- Return true if E comes from an instance that is not yet frozen
function Is_Class_Wide_Interface_Type (E : Entity_Id) return Boolean;
-- Return True when E is a class-wide interface type or an access to
-- a class-wide interface type.
function Is_Direct_Deep_Call (Subp : Entity_Id) return Boolean;
-- Determine if Subp denotes a non-dispatching call to a Deep routine
function New_Value (From : Node_Id) return Node_Id;
-- From is the original Expression. New_Value is equivalent to a call
-- to Duplicate_Subexpr with an explicit dereference when From is an
-- access parameter.
--------------------------
-- Add_Actual_Parameter --
--------------------------
procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
Actual_Expr : constant Node_Id :=
Explicit_Actual_Parameter (Insert_Param);
begin
-- Case of insertion is first named actual
if No (Prev) or else
Nkind (Parent (Prev)) /= N_Parameter_Association
then
Set_Next_Named_Actual
(Insert_Param, First_Named_Actual (Call_Node));
Set_First_Named_Actual (Call_Node, Actual_Expr);
if No (Prev) then
if No (Parameter_Associations (Call_Node)) then
Set_Parameter_Associations (Call_Node, New_List);
end if;
Append (Insert_Param, Parameter_Associations (Call_Node));
else
Insert_After (Prev, Insert_Param);
end if;
-- Case of insertion is not first named actual
else
Set_Next_Named_Actual
(Insert_Param, Next_Named_Actual (Parent (Prev)));
Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
Append (Insert_Param, Parameter_Associations (Call_Node));
end if;
Prev := Actual_Expr;
end Add_Actual_Parameter;
--------------------------------------
-- Add_Cond_Expression_Extra_Actual --
--------------------------------------
procedure Add_Cond_Expression_Extra_Actual
(Formal : Entity_Id)
is
Decl : Node_Id;
Lvl : Entity_Id;
procedure Insert_Level_Assign (Branch : Node_Id);
-- Recursively add assignment of the level temporary on each branch
-- while moving through nested conditional expressions.
-------------------------
-- Insert_Level_Assign --
-------------------------
procedure Insert_Level_Assign (Branch : Node_Id) is
procedure Expand_Branch (Res_Assn : Node_Id);
-- Perform expansion or iterate further within nested
-- conditionals given the object declaration or assignment to
-- result object created during expansion which represents a
-- branch of the conditional expression.
-------------------
-- Expand_Branch --
-------------------
procedure Expand_Branch (Res_Assn : Node_Id) is
begin
pragma Assert (Nkind (Res_Assn) in
N_Assignment_Statement |
N_Object_Declaration);
-- There are more nested conditional expressions so we must go
-- deeper.
if Nkind (Expression (Res_Assn)) = N_Expression_With_Actions
and then
Nkind (Original_Node (Expression (Res_Assn)))
in N_Case_Expression | N_If_Expression
then
Insert_Level_Assign
(Expression (Res_Assn));
-- Add the level assignment
else
Insert_Before_And_Analyze (Res_Assn,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Lvl, Loc),
Expression =>
Accessibility_Level
(Expr => Expression (Res_Assn),
Level => Dynamic_Level,
Allow_Alt_Model => False)));
end if;
end Expand_Branch;
Cond : Node_Id;
Alt : Node_Id;
-- Start of processing for Insert_Level_Assign
begin
-- Examine further nested condtionals
pragma Assert (Nkind (Branch) =
N_Expression_With_Actions);
-- Find the relevant statement in the actions
Cond := First (Actions (Branch));
while Present (Cond) loop
exit when Nkind (Cond) in N_Case_Statement | N_If_Statement;
Next (Cond);
end loop;
-- The conditional expression may have been optimized away, so
-- examine the actions in the branch.
if No (Cond) then
Expand_Branch (Last (Actions (Branch)));
-- Iterate through if expression branches
elsif Nkind (Cond) = N_If_Statement then
Expand_Branch (Last (Then_Statements (Cond)));
Expand_Branch (Last (Else_Statements (Cond)));
-- Iterate through case alternatives
elsif Nkind (Cond) = N_Case_Statement then
Alt := First (Alternatives (Cond));
while Present (Alt) loop
Expand_Branch (Last (Statements (Alt)));
Next (Alt);
end loop;
end if;
end Insert_Level_Assign;
-- Start of processing for cond expression case
begin
-- Create declaration of a temporary to store the accessibility
-- level of each branch of the conditional expression.
Lvl := Make_Temporary (Loc, 'L');
Decl := Make_Object_Declaration (Loc,
Defining_Identifier => Lvl,
Object_Definition =>
New_Occurrence_Of (Standard_Natural, Loc));
-- Install the declaration and perform necessary expansion if we
-- are dealing with a procedure call.
if Nkind (Call_Node) = N_Procedure_Call_Statement then
-- Generate:
-- Lvl : Natural;
-- Call (
-- {do
-- If_Exp_Res : Typ;
-- if Cond then
-- Lvl := 0; -- Access level
-- If_Exp_Res := Exp;
-- ...
-- in If_Exp_Res end;},
-- Lvl,
-- ...
-- )
Insert_Before_And_Analyze (Call_Node, Decl);
-- Ditto for a function call. Note that we do not wrap the function
-- call into an expression with action to avoid bad interactions with
-- Exp_Ch4.Process_Transient_In_Expression.
else
-- Generate:
-- Lvl : Natural; -- placed above the function call
-- ...
-- Func_Call (
-- {do
-- If_Exp_Res : Typ
-- if Cond then
-- Lvl := 0; -- Access level
-- If_Exp_Res := Exp;
-- in If_Exp_Res end;},
-- Lvl,
-- ...
-- )
Insert_Action (Call_Node, Decl);
Analyze (Call_Node);
end if;
-- Decorate the conditional expression with assignments to our level
-- temporary.
Insert_Level_Assign (Prev);
-- Make our level temporary the passed actual
Add_Extra_Actual
(Expr => New_Occurrence_Of (Lvl, Loc),
EF => Extra_Accessibility (Formal));
end Add_Cond_Expression_Extra_Actual;
----------------------
-- Add_Extra_Actual --
----------------------
procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
Loc : constant Source_Ptr := Sloc (Expr);
begin
if Extra_Actuals = No_List then
Extra_Actuals := New_List;
Set_Parent (Extra_Actuals, Call_Node);
end if;
Append_To (Extra_Actuals,
Make_Parameter_Association (Loc,
Selector_Name => New_Occurrence_Of (EF, Loc),
Explicit_Actual_Parameter => Expr));
Analyze_And_Resolve (Expr, Etype (EF));
if Nkind (Call_Node) = N_Function_Call then
Set_Is_Accessibility_Actual (Parent (Expr));
end if;
end Add_Extra_Actual;
------------------------------------
-- Add_View_Conversion_Invariants --
------------------------------------
procedure Add_View_Conversion_Invariants
(Formal : Entity_Id;
Actual : Node_Id)
is
Arg : Entity_Id;
Curr_Typ : Entity_Id;
Inv_Checks : List_Id;
Par_Typ : Entity_Id;
begin
Inv_Checks := No_List;
-- Extract the argument from a potentially nested set of view
-- conversions.
Arg := Actual;
while Nkind (Arg) = N_Type_Conversion loop
Arg := Expression (Arg);
end loop;
-- Move up the derivation chain starting with the type of the formal
-- parameter down to the type of the actual object.
Curr_Typ := Empty;
Par_Typ := Etype (Arg);
while Par_Typ /= Etype (Formal) and Par_Typ /= Curr_Typ loop
Curr_Typ := Par_Typ;
if Has_Invariants (Curr_Typ)
and then Present (Invariant_Procedure (Curr_Typ))
then
-- Verify the invariant of the current type. Generate:
-- <Curr_Typ>Invariant (Curr_Typ (Arg));
Prepend_New_To (Inv_Checks,
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of
(Invariant_Procedure (Curr_Typ), Loc),
Parameter_Associations => New_List (
Make_Type_Conversion (Loc,
Subtype_Mark => New_Occurrence_Of (Curr_Typ, Loc),
Expression => New_Copy_Tree (Arg)))));
end if;
Par_Typ := Base_Type (Etype (Curr_Typ));
end loop;
-- If the node is a function call the generated tests have been
-- already handled in Insert_Post_Call_Actions.
if not Is_Empty_List (Inv_Checks)
and then Nkind (Call_Node) = N_Procedure_Call_Statement
then
Insert_Actions_After (Call_Node, Inv_Checks);
end if;
end Add_View_Conversion_Invariants;
-----------------------------
-- Can_Fold_Predicate_Call --
-----------------------------
function Can_Fold_Predicate_Call (P : Entity_Id) return Boolean is
Actual : Node_Id;
function Augments_Other_Dynamic_Predicate (DP_Aspect_Spec : Node_Id)
return Boolean;
-- Given a Dynamic_Predicate aspect aspecification for a
-- discrete type, returns True iff another DP specification
-- applies (indirectly, via a subtype type or a derived type)
-- to the same entity that this aspect spec applies to.
function May_Fold (N : Node_Id) return Traverse_Result;
-- The predicate expression is foldable if it only contains operators
-- and literals. During this check, we also replace occurrences of
-- the formal of the constructed predicate function with the static
-- value of the actual. This is done on a copy of the analyzed
-- expression for the predicate.
--------------------------------------
-- Augments_Other_Dynamic_Predicate --
--------------------------------------
function Augments_Other_Dynamic_Predicate (DP_Aspect_Spec : Node_Id)
return Boolean
is
Aspect_Bearer : Entity_Id := Entity (DP_Aspect_Spec);
begin
loop
Aspect_Bearer := Nearest_Ancestor (Aspect_Bearer);
if not Present (Aspect_Bearer) then
return False;
end if;
declare
Aspect_Spec : constant Node_Id :=
Find_Aspect (Aspect_Bearer, Aspect_Dynamic_Predicate);
begin
if Present (Aspect_Spec)
and then Aspect_Spec /= DP_Aspect_Spec
then
-- Found another Dynamic_Predicate aspect spec
return True;
end if;
end;
end loop;
end Augments_Other_Dynamic_Predicate;
--------------
-- May_Fold --
--------------
function May_Fold (N : Node_Id) return Traverse_Result is
begin
case Nkind (N) is
when N_Op =>
return OK;
when N_Expanded_Name
| N_Identifier
=>
if Ekind (Entity (N)) = E_In_Parameter
and then Entity (N) = First_Entity (P)
then
Rewrite (N, New_Copy (Actual));
Set_Is_Static_Expression (N);
return OK;
elsif Ekind (Entity (N)) = E_Enumeration_Literal then
return OK;
else
return Abandon;
end if;
when N_Case_Expression
| N_If_Expression
=>
return OK;
when N_Integer_Literal =>
return OK;
when others =>
return Abandon;
end case;
end May_Fold;
function Try_Fold is new Traverse_Func (May_Fold);
-- Other Local variables
Subt : constant Entity_Id := Etype (First_Entity (P));
Aspect : Node_Id;
Pred : Node_Id;
-- Start of processing for Can_Fold_Predicate_Call
begin
-- Folding is only interesting if the actual is static and its type
-- has a Dynamic_Predicate aspect. For CodePeer we preserve the
-- function call.
Actual := First (Parameter_Associations (Call_Node));
Aspect := Find_Aspect (Subt, Aspect_Dynamic_Predicate);
-- If actual is a declared constant, retrieve its value
if Is_Entity_Name (Actual)
and then Ekind (Entity (Actual)) = E_Constant
then
Actual := Constant_Value (Entity (Actual));
end if;
if No (Actual)
or else Nkind (Actual) /= N_Integer_Literal
or else not Has_Dynamic_Predicate_Aspect (Subt)
or else No (Aspect)
-- Do not fold if multiple applicable predicate aspects
or else Present (Find_Aspect (Subt, Aspect_Static_Predicate))
or else Present (Find_Aspect (Subt, Aspect_Predicate))
or else Augments_Other_Dynamic_Predicate (Aspect)
or else CodePeer_Mode
then
return False;
end if;
-- Retrieve the analyzed expression for the predicate
Pred := New_Copy_Tree (Expression (Aspect));
if Try_Fold (Pred) = OK then
Rewrite (Call_Node, Pred);
Analyze_And_Resolve (Call_Node, Standard_Boolean);
return True;
-- Otherwise continue the expansion of the function call
else
return False;
end if;
end Can_Fold_Predicate_Call;
------------------------------
-- Check_Subprogram_Variant --
------------------------------
procedure Check_Subprogram_Variant is
Variant_Prag : constant Node_Id :=
Get_Pragma (Current_Scope, Pragma_Subprogram_Variant);
Variant_Proc : Entity_Id;
begin
if Present (Variant_Prag) and then Is_Checked (Variant_Prag) then
-- Analysis of the pragma rewrites its argument with a reference
-- to the internally generated procedure.
Variant_Proc :=
Entity
(Expression
(First
(Pragma_Argument_Associations (Variant_Prag))));
Insert_Action (Call_Node,
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of (Variant_Proc, Loc),
Parameter_Associations =>
New_Copy_List (Parameter_Associations (Call_Node))));
end if;
end Check_Subprogram_Variant;
---------------------------
-- Inherited_From_Formal --
---------------------------
function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
Par : Entity_Id;
Gen_Par : Entity_Id;
Gen_Prim : Elist_Id;
Elmt : Elmt_Id;
Indic : Node_Id;
begin
-- If the operation is inherited, it is attached to the corresponding
-- type derivation. If the parent in the derivation is a generic
-- actual, it is a subtype of the actual, and we have to recover the
-- original derived type declaration to find the proper parent.
if Nkind (Parent (S)) /= N_Full_Type_Declaration
or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
or else Nkind (Type_Definition (Original_Node (Parent (S)))) /=
N_Derived_Type_Definition
or else not In_Instance
then
return Empty;
else
Indic :=
Subtype_Indication
(Type_Definition (Original_Node (Parent (S))));
if Nkind (Indic) = N_Subtype_Indication then
Par := Entity (Subtype_Mark (Indic));
else
Par := Entity (Indic);
end if;
end if;
if not Is_Generic_Actual_Type (Par)
or else Is_Tagged_Type (Par)
or else Nkind (Parent (Par)) /= N_Subtype_Declaration
or else not In_Open_Scopes (Scope (Par))
then
return Empty;
else
Gen_Par := Generic_Parent_Type (Parent (Par));
end if;
-- If the actual has no generic parent type, the formal is not
-- a formal derived type, so nothing to inherit.
if No (Gen_Par) then
return Empty;
end if;
-- If the generic parent type is still the generic type, this is a
-- private formal, not a derived formal, and there are no operations
-- inherited from the formal.
if Nkind (Parent (Gen_Par)) = N_Formal_Type_Declaration then
return Empty;
end if;
Gen_Prim := Collect_Primitive_Operations (Gen_Par);
Elmt := First_Elmt (Gen_Prim);
while Present (Elmt) loop
if Chars (Node (Elmt)) = Chars (S) then
declare
F1 : Entity_Id;
F2 : Entity_Id;
begin
F1 := First_Formal (S);
F2 := First_Formal (Node (Elmt));
while Present (F1)
and then Present (F2)
loop
if Etype (F1) = Etype (F2)
or else Etype (F2) = Gen_Par
then
Next_Formal (F1);
Next_Formal (F2);
else
Next_Elmt (Elmt);
exit; -- not the right subprogram
end if;
return Node (Elmt);
end loop;
end;
else
Next_Elmt (Elmt);
end if;
end loop;
raise Program_Error;
end Inherited_From_Formal;
--------------------------
-- In_Unfrozen_Instance --
--------------------------
function In_Unfrozen_Instance (E : Entity_Id) return Boolean is
S : Entity_Id;
begin
S := E;
while Present (S) and then S /= Standard_Standard loop
if Is_Generic_Instance (S)
and then Present (Freeze_Node (S))
and then not Analyzed (Freeze_Node (S))
then
return True;
end if;
S := Scope (S);
end loop;
return False;
end In_Unfrozen_Instance;
----------------------------------
-- Is_Class_Wide_Interface_Type --
----------------------------------
function Is_Class_Wide_Interface_Type (E : Entity_Id) return Boolean is
DDT : Entity_Id;
Typ : Entity_Id := E;
begin
if Has_Non_Limited_View (Typ) then
Typ := Non_Limited_View (Typ);
end if;
if Ekind (Typ) = E_Anonymous_Access_Type then
DDT := Directly_Designated_Type (Typ);
if Has_Non_Limited_View (DDT) then
DDT := Non_Limited_View (DDT);
end if;
return Is_Class_Wide_Type (DDT) and then Is_Interface (DDT);
else
return Is_Class_Wide_Type (Typ) and then Is_Interface (Typ);
end if;
end Is_Class_Wide_Interface_Type;
-------------------------
-- Is_Direct_Deep_Call --
-------------------------
function Is_Direct_Deep_Call (Subp : Entity_Id) return Boolean is
begin
if Is_TSS (Subp, TSS_Deep_Adjust)
or else Is_TSS (Subp, TSS_Deep_Finalize)
or else Is_TSS (Subp, TSS_Deep_Initialize)
then
declare
Actual : Node_Id;
Formal : Entity_Id;
begin
Actual := First (Parameter_Associations (Call_Node));
Formal := First_Formal (Subp);
while Present (Actual)
and then Present (Formal)
loop
if Nkind (Actual) = N_Identifier
and then Is_Controlling_Actual (Actual)
and then Etype (Actual) = Etype (Formal)
then
return True;
end if;
Next (Actual);
Next_Formal (Formal);
end loop;
end;
end if;
return False;
end Is_Direct_Deep_Call;
---------------
-- New_Value --
---------------
function New_Value (From : Node_Id) return Node_Id is
Res : constant Node_Id := Duplicate_Subexpr (From);
begin
if Is_Access_Type (Etype (From)) then
return Make_Explicit_Dereference (Sloc (From), Prefix => Res);
else
return Res;
end if;
end New_Value;
-- Local variables
Remote : constant Boolean := Is_Remote_Call (Call_Node);
Actual : Node_Id;
Formal : Entity_Id;
Orig_Subp : Entity_Id := Empty;
Param_Count : Positive;
Parent_Formal : Entity_Id;
Parent_Subp : Entity_Id;
Scop : Entity_Id;
Subp : Entity_Id;
CW_Interface_Formals_Present : Boolean := False;
-- Start of processing for Expand_Call_Helper
begin
Post_Call := New_List;
-- Expand the function or procedure call if the first actual has a
-- declared dimension aspect, and the subprogram is declared in one
-- of the dimension I/O packages.
if Ada_Version >= Ada_2012
and then Nkind (Call_Node) in N_Subprogram_Call
and then Present (Parameter_Associations (Call_Node))
then
Expand_Put_Call_With_Symbol (Call_Node);
end if;
-- Ignore if previous error
if Nkind (Call_Node) in N_Has_Etype
and then Etype (Call_Node) = Any_Type
then
return;
end if;
-- Call using access to subprogram with explicit dereference
if Nkind (Name (Call_Node)) = N_Explicit_Dereference then
Subp := Etype (Name (Call_Node));
Parent_Subp := Empty;
-- Case of call to simple entry, where the Name is a selected component
-- whose prefix is the task, and whose selector name is the entry name
elsif Nkind (Name (Call_Node)) = N_Selected_Component then
Subp := Entity (Selector_Name (Name (Call_Node)));
Parent_Subp := Empty;
-- Case of call to member of entry family, where Name is an indexed
-- component, with the prefix being a selected component giving the
-- task and entry family name, and the index being the entry index.
elsif Nkind (Name (Call_Node)) = N_Indexed_Component then
Subp := Entity (Selector_Name (Prefix (Name (Call_Node))));
Parent_Subp := Empty;
-- Normal case
else
Subp := Entity (Name (Call_Node));
Parent_Subp := Alias (Subp);
-- Replace call to Raise_Exception by call to Raise_Exception_Always
-- if we can tell that the first parameter cannot possibly be null.
-- This improves efficiency by avoiding a run-time test.
-- We do not do this if Raise_Exception_Always does not exist, which
-- can happen in configurable run time profiles which provide only a
-- Raise_Exception.
if Is_RTE (Subp, RE_Raise_Exception)
and then RTE_Available (RE_Raise_Exception_Always)
then
declare
FA : constant Node_Id :=
Original_Node (First_Actual (Call_Node));
begin
-- The case we catch is where the first argument is obtained
-- using the Identity attribute (which must always be
-- non-null).
if Nkind (FA) = N_Attribute_Reference
and then Attribute_Name (FA) = Name_Identity
then
Subp := RTE (RE_Raise_Exception_Always);
Set_Name (Call_Node, New_Occurrence_Of (Subp, Loc));
end if;
end;
end if;
if Ekind (Subp) = E_Entry then
Parent_Subp := Empty;
end if;
end if;
-- Ada 2005 (AI-345): We have a procedure call as a triggering
-- alternative in an asynchronous select or as an entry call in
-- a conditional or timed select. Check whether the procedure call
-- is a renaming of an entry and rewrite it as an entry call.
if Ada_Version >= Ada_2005
and then Nkind (Call_Node) = N_Procedure_Call_Statement
and then
((Nkind (Parent (Call_Node)) = N_Triggering_Alternative
and then Triggering_Statement (Parent (Call_Node)) = Call_Node)
or else
(Nkind (Parent (Call_Node)) = N_Entry_Call_Alternative
and then Entry_Call_Statement (Parent (Call_Node)) = Call_Node))
then
declare
Ren_Decl : Node_Id;
Ren_Root : Entity_Id := Subp;
begin
-- This may be a chain of renamings, find the root
if Present (Alias (Ren_Root)) then
Ren_Root := Alias (Ren_Root);
end if;
if Present (Parent (Ren_Root))
and then Present (Original_Node (Parent (Parent (Ren_Root))))
then
Ren_Decl := Original_Node (Parent (Parent (Ren_Root)));
if Nkind (Ren_Decl) = N_Subprogram_Renaming_Declaration then
Rewrite (Call_Node,
Make_Entry_Call_Statement (Loc,
Name =>
New_Copy_Tree (Name (Ren_Decl)),
Parameter_Associations =>
New_Copy_List_Tree
(Parameter_Associations (Call_Node))));
return;
end if;
end if;
end;
end if;
-- If this is a call to a predicate function, try to constant fold it
if Nkind (Call_Node) = N_Function_Call
and then Is_Entity_Name (Name (Call_Node))
and then Is_Predicate_Function (Subp)
and then Can_Fold_Predicate_Call (Subp)
then
return;
end if;
if Transform_Function_Array
and then Nkind (Call_Node) = N_Function_Call
and then Is_Entity_Name (Name (Call_Node))
then
declare
Func_Id : constant Entity_Id :=
Ultimate_Alias (Entity (Name (Call_Node)));
begin
-- When generating C code, transform a function call that returns
-- a constrained array type into procedure form.
if Rewritten_For_C (Func_Id) then
-- For internally generated calls ensure that they reference
-- the entity of the spec of the called function (needed since
-- the expander may generate calls using the entity of their
-- body).
if not Comes_From_Source (Call_Node)
and then Nkind (Unit_Declaration_Node (Func_Id)) =
N_Subprogram_Body
then
Set_Entity (Name (Call_Node),
Corresponding_Function
(Corresponding_Procedure (Func_Id)));
end if;
Rewrite_Function_Call_For_C (Call_Node);
return;
-- Also introduce a temporary for functions that return a record
-- called within another procedure or function call, since records
-- are passed by pointer in the generated C code, and we cannot
-- take a pointer from a subprogram call.
elsif Modify_Tree_For_C
and then Nkind (Parent (Call_Node)) in N_Subprogram_Call
and then Is_Record_Type (Etype (Func_Id))
then
declare
Temp_Id : constant Entity_Id := Make_Temporary (Loc, 'T');
Decl : Node_Id;
begin
-- Generate:
-- Temp : ... := Func_Call (...);
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp_Id,
Object_Definition =>
New_Occurrence_Of (Etype (Func_Id), Loc),
Expression =>
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (Func_Id, Loc),
Parameter_Associations =>
Parameter_Associations (Call_Node)));
Insert_Action (Parent (Call_Node), Decl);
Rewrite (Call_Node, New_Occurrence_Of (Temp_Id, Loc));
return;
end;
end if;
end;
end if;
-- First step, compute extra actuals, corresponding to any Extra_Formals
-- present. Note that we do not access Extra_Formals directly, instead
-- we simply note the presence of the extra formals as we process the
-- regular formals collecting corresponding actuals in Extra_Actuals.
-- We also generate any required range checks for actuals for in formals
-- as we go through the loop, since this is a convenient place to do it.
-- (Though it seems that this would be better done in Expand_Actuals???)
-- Special case: Thunks must not compute the extra actuals; they must
-- just propagate to the target primitive their extra actuals.
if Is_Thunk (Current_Scope)
and then Thunk_Entity (Current_Scope) = Subp
and then Present (Extra_Formals (Subp))
then
pragma Assert (Present (Extra_Formals (Current_Scope)));
declare
Target_Formal : Entity_Id;
Thunk_Formal : Entity_Id;
begin
Target_Formal := Extra_Formals (Subp);
Thunk_Formal := Extra_Formals (Current_Scope);
while Present (Target_Formal) loop
Add_Extra_Actual
(Expr => New_Occurrence_Of (Thunk_Formal, Loc),
EF => Thunk_Formal);
Target_Formal := Extra_Formal (Target_Formal);
Thunk_Formal := Extra_Formal (Thunk_Formal);
end loop;
while Is_Non_Empty_List (Extra_Actuals) loop
Add_Actual_Parameter (Remove_Head (Extra_Actuals));
end loop;
Expand_Actuals (Call_Node, Subp, Post_Call);
pragma Assert (Is_Empty_List (Post_Call));
pragma Assert (Check_Number_Of_Actuals (Call_Node, Subp));
pragma Assert (Check_BIP_Actuals (Call_Node, Subp));
return;
end;
end if;
Formal := First_Formal (Subp);
Actual := First_Actual (Call_Node);
Param_Count := 1;
while Present (Formal) loop
-- Prepare to examine current entry
Prev := Actual;
-- Ada 2005 (AI-251): Check if any formal is a class-wide interface
-- to expand it in a further round.
CW_Interface_Formals_Present :=
CW_Interface_Formals_Present
or else Is_Class_Wide_Interface_Type (Etype (Formal));
-- Create possible extra actual for constrained case. Usually, the
-- extra actual is of the form actual'constrained, but since this
-- attribute is only available for unconstrained records, TRUE is
-- expanded if the type of the formal happens to be constrained (for
-- instance when this procedure is inherited from an unconstrained
-- record to a constrained one) or if the actual has no discriminant
-- (its type is constrained). An exception to this is the case of a
-- private type without discriminants. In this case we pass FALSE
-- because the object has underlying discriminants with defaults.
if Present (Extra_Constrained (Formal)) then
if Is_Private_Type (Etype (Prev))
and then not Has_Discriminants (Base_Type (Etype (Prev)))
then
Add_Extra_Actual
(Expr => New_Occurrence_Of (Standard_False, Loc),
EF => Extra_Constrained (Formal));
elsif Is_Constrained (Etype (Formal))
or else not Has_Discriminants (Etype (Prev))
then
Add_Extra_Actual
(Expr => New_Occurrence_Of (Standard_True, Loc),
EF => Extra_Constrained (Formal));
-- Do not produce extra actuals for Unchecked_Union parameters.
-- Jump directly to the end of the loop.
elsif Is_Unchecked_Union (Base_Type (Etype (Actual))) then
goto Skip_Extra_Actual_Generation;
else
-- If the actual is a type conversion, then the constrained
-- test applies to the actual, not the target type.
declare
Act_Prev : Node_Id;
begin
-- Test for unchecked conversions as well, which can occur
-- as out parameter actuals on calls to stream procedures.
Act_Prev := Prev;
while Nkind (Act_Prev) in N_Type_Conversion
| N_Unchecked_Type_Conversion
loop
Act_Prev := Expression (Act_Prev);
end loop;
-- If the expression is a conversion of a dereference, this
-- is internally generated code that manipulates addresses,
-- e.g. when building interface tables. No check should
-- occur in this case, and the discriminated object is not
-- directly at hand.
if not Comes_From_Source (Actual)
and then Nkind (Actual) = N_Unchecked_Type_Conversion
and then Nkind (Act_Prev) = N_Explicit_Dereference
then
Add_Extra_Actual
(Expr => New_Occurrence_Of (Standard_False, Loc),
EF => Extra_Constrained (Formal));
else
Add_Extra_Actual
(Expr =>
Make_Attribute_Reference (Sloc (Prev),
Prefix =>
Duplicate_Subexpr_No_Checks
(Act_Prev, Name_Req => True),
Attribute_Name => Name_Constrained),
EF => Extra_Constrained (Formal));
end if;
end;
end if;
end if;
-- Create possible extra actual for accessibility level
if Present (Extra_Accessibility (Formal)) then
-- Ada 2005 (AI-251): Thunks must propagate the extra actuals of
-- accessibility levels.
if Is_Thunk (Current_Scope) then
declare
Parm_Ent : Entity_Id;
begin
if Is_Controlling_Actual (Actual) then
-- Find the corresponding actual of the thunk
Parm_Ent := First_Entity (Current_Scope);
for J in 2 .. Param_Count loop
Next_Entity (Parm_Ent);
end loop;
-- Handle unchecked conversion of access types generated
-- in thunks (cf. Expand_Interface_Thunk).
elsif Is_Access_Type (Etype (Actual))
and then Nkind (Actual) = N_Unchecked_Type_Conversion
then
Parm_Ent := Entity (Expression (Actual));
else pragma Assert (Is_Entity_Name (Actual));
Parm_Ent := Entity (Actual);
end if;
Add_Extra_Actual
(Expr => Accessibility_Level
(Expr => Parm_Ent,
Level => Dynamic_Level,
Allow_Alt_Model => False),
EF => Extra_Accessibility (Formal));
end;
-- Conditional expressions
elsif Nkind (Prev) = N_Expression_With_Actions
and then Nkind (Original_Node (Prev)) in
N_If_Expression | N_Case_Expression
then
Add_Cond_Expression_Extra_Actual (Formal);
-- Internal constant generated to remove side effects (normally
-- from the expansion of dispatching calls).
-- First verify the actual is internal
elsif not Comes_From_Source (Prev)
and then Original_Node (Prev) = Prev
-- Next check that the actual is a constant
and then Nkind (Prev) = N_Identifier
and then Ekind (Entity (Prev)) = E_Constant
and then Nkind (Parent (Entity (Prev))) = N_Object_Declaration
then
-- Generate the accessibility level based on the expression in
-- the constant's declaration.
Add_Extra_Actual
(Expr => Accessibility_Level
(Expr => Expression
(Parent (Entity (Prev))),
Level => Dynamic_Level,
Allow_Alt_Model => False),
EF => Extra_Accessibility (Formal));
-- Normal case
else
Add_Extra_Actual
(Expr => Accessibility_Level
(Expr => Prev,
Level => Dynamic_Level,
Allow_Alt_Model => False),
EF => Extra_Accessibility (Formal));
end if;
end if;
-- Perform the check of 4.6(49) that prevents a null value from being
-- passed as an actual to an access parameter. Note that the check
-- is elided in the common cases of passing an access attribute or
-- access parameter as an actual. Also, we currently don't enforce
-- this check for expander-generated actuals and when -gnatdj is set.
if Ada_Version >= Ada_2005 then
-- Ada 2005 (AI-231): Check null-excluding access types. Note that
-- the intent of 6.4.1(13) is that null-exclusion checks should
-- not be done for 'out' parameters, even though it refers only
-- to constraint checks, and a null_exclusion is not a constraint.
-- Note that AI05-0196-1 corrects this mistake in the RM.
if Is_Access_Type (Etype (Formal))
and then Can_Never_Be_Null (Etype (Formal))
and then Ekind (Formal) /= E_Out_Parameter
and then Nkind (Prev) /= N_Raise_Constraint_Error
and then (Known_Null (Prev)
or else not Can_Never_Be_Null (Etype (Prev)))
then
Install_Null_Excluding_Check (Prev);
end if;
-- Ada_Version < Ada_2005
else
if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
or else Access_Checks_Suppressed (Subp)
then
null;
elsif Debug_Flag_J then
null;
elsif not Comes_From_Source (Prev) then
null;
elsif Is_Entity_Name (Prev)
and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
then
null;
elsif Nkind (Prev) in N_Allocator | N_Attribute_Reference then
null;
else
Install_Null_Excluding_Check (Prev);
end if;
end if;
-- Perform appropriate validity checks on parameters that
-- are entities.
if Validity_Checks_On then
if (Ekind (Formal) = E_In_Parameter
and then Validity_Check_In_Params)
or else
(Ekind (Formal) = E_In_Out_Parameter
and then Validity_Check_In_Out_Params)
then
-- If the actual is an indexed component of a packed type (or
-- is an indexed or selected component whose prefix recursively
-- meets this condition), it has not been expanded yet. It will
-- be copied in the validity code that follows, and has to be
-- expanded appropriately, so reanalyze it.
-- What we do is just to unset analyzed bits on prefixes till
-- we reach something that does not have a prefix.
declare
Nod : Node_Id;
begin
Nod := Actual;
while Nkind (Nod) in
N_Indexed_Component | N_Selected_Component
loop
Set_Analyzed (Nod, False);
Nod := Prefix (Nod);
end loop;
end;
Ensure_Valid (Actual);
end if;
end if;
-- For IN OUT and OUT parameters, ensure that subscripts are valid
-- since this is a left side reference. We only do this for calls
-- from the source program since we assume that compiler generated
-- calls explicitly generate any required checks. We also need it
-- only if we are doing standard validity checks, since clearly it is
-- not needed if validity checks are off, and in subscript validity
-- checking mode, all indexed components are checked with a call
-- directly from Expand_N_Indexed_Component.
if Comes_From_Source (Call_Node)
and then Ekind (Formal) /= E_In_Parameter
and then Validity_Checks_On
and then Validity_Check_Default
and then not Validity_Check_Subscripts
then
Check_Valid_Lvalue_Subscripts (Actual);
end if;
-- Mark any scalar OUT parameter that is a simple variable as no
-- longer known to be valid (unless the type is always valid). This
-- reflects the fact that if an OUT parameter is never set in a
-- procedure, then it can become invalid on the procedure return.
if Ekind (Formal) = E_Out_Parameter
and then Is_Entity_Name (Actual)
and then Ekind (Entity (Actual)) = E_Variable
and then not Is_Known_Valid (Etype (Actual))
then
Set_Is_Known_Valid (Entity (Actual), False);
end if;
-- For an OUT or IN OUT parameter, if the actual is an entity, then
-- clear current values, since they can be clobbered. We are probably
-- doing this in more places than we need to, but better safe than
-- sorry when it comes to retaining bad current values.
if Ekind (Formal) /= E_In_Parameter
and then Is_Entity_Name (Actual)
and then Present (Entity (Actual))
then
declare
Ent : constant Entity_Id := Entity (Actual);
Sav : Node_Id;
begin
-- For an OUT or IN OUT parameter that is an assignable entity,
-- we do not want to clobber the Last_Assignment field, since
-- if it is set, it was precisely because it is indeed an OUT
-- or IN OUT parameter. We do reset the Is_Known_Valid flag
-- since the subprogram could have returned in invalid value.
if Is_Assignable (Ent) then
Sav := Last_Assignment (Ent);
Kill_Current_Values (Ent);
Set_Last_Assignment (Ent, Sav);
Set_Is_Known_Valid (Ent, False);
Set_Is_True_Constant (Ent, False);
-- For all other cases, just kill the current values
else
Kill_Current_Values (Ent);
end if;
end;
end if;
-- If the formal is class-wide and the actual is an aggregate, force
-- evaluation so that the back end who does not know about class-wide
-- type, does not generate a temporary of the wrong size.
if not Is_Class_Wide_Type (Etype (Formal)) then
null;
elsif Nkind (Actual) = N_Aggregate
or else (Nkind (Actual) = N_Qualified_Expression
and then Nkind (Expression (Actual)) = N_Aggregate)
then
Force_Evaluation (Actual);
end if;
-- In a remote call, if the formal is of a class-wide type, check
-- that the actual meets the requirements described in E.4(18).
if Remote and then Is_Class_Wide_Type (Etype (Formal)) then
Insert_Action (Actual,
Make_Transportable_Check (Loc,
Duplicate_Subexpr_Move_Checks (Actual)));
end if;
-- Perform invariant checks for all intermediate types in a view
-- conversion after successful return from a call that passes the
-- view conversion as an IN OUT or OUT parameter (RM 7.3.2 (12/3,
-- 13/3, 14/3)). Consider only source conversion in order to avoid
-- generating spurious checks on complex expansion such as object
-- initialization through an extension aggregate.
if Comes_From_Source (Call_Node)
and then Ekind (Formal) /= E_In_Parameter
and then Nkind (Actual) = N_Type_Conversion
then
Add_View_Conversion_Invariants (Formal, Actual);
end if;
-- Generating C the initialization of an allocator is performed by
-- means of individual statements, and hence it must be done before
-- the call.
if Modify_Tree_For_C
and then Nkind (Actual) = N_Allocator
and then Nkind (Expression (Actual)) = N_Qualified_Expression
then
Remove_Side_Effects (Actual);
end if;
-- This label is required when skipping extra actual generation for
-- Unchecked_Union parameters.
<<Skip_Extra_Actual_Generation>>
Param_Count := Param_Count + 1;
Next_Actual (Actual);
Next_Formal (Formal);
end loop;
-- If we are calling an Ada 2012 function which needs to have the
-- "accessibility level determined by the point of call" (AI05-0234)
-- passed in to it, then pass it in.
if Ekind (Subp) in E_Function | E_Operator | E_Subprogram_Type
and then
Present (Extra_Accessibility_Of_Result (Ultimate_Alias (Subp)))
then
declare
Extra_Form : Node_Id := Empty;
Level : Node_Id := Empty;
begin
-- Detect cases where the function call has been internally
-- generated by examining the original node and return library
-- level - taking care to avoid ignoring function calls expanded
-- in prefix notation.
if Nkind (Original_Node (Call_Node)) not in N_Function_Call
| N_Selected_Component
| N_Indexed_Component
then
Level := Make_Integer_Literal
(Loc, Scope_Depth (Standard_Standard));
-- Otherwise get the level normally based on the call node
else
Level := Accessibility_Level
(Expr => Call_Node,
Level => Dynamic_Level,
Allow_Alt_Model => False);
end if;
-- It may be possible that we are re-expanding an already
-- expanded call when are are dealing with dispatching ???
if not Present (Parameter_Associations (Call_Node))
or else Nkind (Last (Parameter_Associations (Call_Node)))
/= N_Parameter_Association
or else not Is_Accessibility_Actual
(Last (Parameter_Associations (Call_Node)))
then
Extra_Form := Extra_Accessibility_Of_Result
(Ultimate_Alias (Subp));
Add_Extra_Actual
(Expr => Level,
EF => Extra_Form);
end if;
end;
end if;
-- If we are expanding the RHS of an assignment we need to check if tag
-- propagation is needed. You might expect this processing to be in
-- Analyze_Assignment but has to be done earlier (bottom-up) because the
-- assignment might be transformed to a declaration for an unconstrained
-- value if the expression is classwide.
if Nkind (Call_Node) = N_Function_Call
and then Is_Tag_Indeterminate (Call_Node)
and then Is_Entity_Name (Name (Call_Node))
then
declare
Ass : Node_Id := Empty;
begin
if Nkind (Parent (Call_Node)) = N_Assignment_Statement then
Ass := Parent (Call_Node);
elsif Nkind (Parent (Call_Node)) = N_Qualified_Expression
and then Nkind (Parent (Parent (Call_Node))) =
N_Assignment_Statement
then
Ass := Parent (Parent (Call_Node));
elsif Nkind (Parent (Call_Node)) = N_Explicit_Dereference
and then Nkind (Parent (Parent (Call_Node))) =
N_Assignment_Statement
then
Ass := Parent (Parent (Call_Node));
end if;
if Present (Ass)
and then Is_Class_Wide_Type (Etype (Name (Ass)))
then
-- Move the error messages below to sem???
if Is_Access_Type (Etype (Call_Node)) then
if Designated_Type (Etype (Call_Node)) /=
Root_Type (Etype (Name (Ass)))
then
Error_Msg_NE
("tag-indeterminate expression must have designated "
& "type& (RM 5.2 (6))",
Call_Node, Root_Type (Etype (Name (Ass))));
else
Propagate_Tag (Name (Ass), Call_Node);
end if;
elsif Etype (Call_Node) /= Root_Type (Etype (Name (Ass))) then
Error_Msg_NE
("tag-indeterminate expression must have type & "
& "(RM 5.2 (6))",
Call_Node, Root_Type (Etype (Name (Ass))));
else
Propagate_Tag (Name (Ass), Call_Node);
end if;
-- The call will be rewritten as a dispatching call, and
-- expanded as such.
return;
end if;
end;
end if;
-- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
-- it to point to the correct secondary virtual table.
if Nkind (Call_Node) in N_Subprogram_Call
and then CW_Interface_Formals_Present
then
Expand_Interface_Actuals (Call_Node);
end if;
-- Install class-wide preconditions runtime check when this is a
-- dispatching primitive that has or inherits class-wide preconditions;
-- otherwise no runtime check is installed.
if Nkind (Call_Node) in N_Subprogram_Call
and then Is_Dispatching_Operation (Subp)
then
Install_Class_Preconditions_Check (Call_Node);
end if;
-- Deals with Dispatch_Call if we still have a call, before expanding
-- extra actuals since this will be done on the re-analysis of the
-- dispatching call. Note that we do not try to shorten the actual list
-- for a dispatching call, it would not make sense to do so. Expansion
-- of dispatching calls is suppressed for VM targets, because the VM
-- back-ends directly handle the generation of dispatching calls and
-- would have to undo any expansion to an indirect call.
if Nkind (Call_Node) in N_Subprogram_Call
and then Present (Controlling_Argument (Call_Node))
then
if Tagged_Type_Expansion then
Expand_Dispatching_Call (Call_Node);
-- Expand_Dispatching_Call takes care of all the needed processing
return;
end if;
-- VM targets
declare
Call_Typ : constant Entity_Id := Etype (Call_Node);
Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
Eq_Prim_Op : Entity_Id := Empty;
New_Call : Node_Id;
Param : Node_Id;
Prev_Call : Node_Id;
begin
Apply_Tag_Checks (Call_Node);
if not Is_Limited_Type (Typ) then
Eq_Prim_Op := Find_Prim_Op (Typ, Name_Op_Eq);
end if;
-- If this is a dispatching "=", we must first compare the
-- tags so we generate: x.tag = y.tag and then x = y
if Subp = Eq_Prim_Op then
-- Mark the node as analyzed to avoid reanalyzing this
-- dispatching call (which would cause a never-ending loop)
Prev_Call := Relocate_Node (Call_Node);
Set_Analyzed (Prev_Call);
Param := First_Actual (Call_Node);
New_Call :=
Make_And_Then (Loc,
Left_Opnd =>
Make_Op_Eq (Loc,
Left_Opnd =>
Make_Selected_Component (Loc,
Prefix => New_Value (Param),
Selector_Name =>
New_Occurrence_Of
(First_Tag_Component (Typ), Loc)),
Right_Opnd =>
Make_Selected_Component (Loc,
Prefix =>
Unchecked_Convert_To (Typ,
New_Value (Next_Actual (Param))),
Selector_Name =>
New_Occurrence_Of
(First_Tag_Component (Typ), Loc))),
Right_Opnd => Prev_Call);
Rewrite (Call_Node, New_Call);
Analyze_And_Resolve
(Call_Node, Call_Typ, Suppress => All_Checks);
end if;
-- Expansion of a dispatching call results in an indirect call,
-- which in turn causes current values to be killed (see
-- Resolve_Call), so on VM targets we do the call here to
-- ensure consistent warnings between VM and non-VM targets.
Kill_Current_Values;
-- If this is a dispatching "=" then we must update the reference
-- to the call node because we generated:
-- x.tag = y.tag and then x = y
if Subp = Eq_Prim_Op then
Call_Node := Right_Opnd (Call_Node);
end if;
end;
end if;
-- Similarly, expand calls to RCI subprograms on which pragma
-- All_Calls_Remote applies. The rewriting will be reanalyzed
-- later. Do this only when the call comes from source since we
-- do not want such a rewriting to occur in expanded code.
if Is_All_Remote_Call (Call_Node) then
Expand_All_Calls_Remote_Subprogram_Call (Call_Node);
-- Similarly, do not add extra actuals for an entry call whose entity
-- is a protected procedure, or for an internal protected subprogram
-- call, because it will be rewritten as a protected subprogram call
-- and reanalyzed (see Expand_Protected_Subprogram_Call).
elsif Is_Protected_Type (Scope (Subp))
and then Ekind (Subp) in E_Procedure | E_Function
then
null;
-- During that loop we gathered the extra actuals (the ones that
-- correspond to Extra_Formals), so now they can be appended.
else
while Is_Non_Empty_List (Extra_Actuals) loop
Add_Actual_Parameter (Remove_Head (Extra_Actuals));
end loop;
end if;
-- At this point we have all the actuals, so this is the point at which
-- the various expansion activities for actuals is carried out.
Expand_Actuals (Call_Node, Subp, Post_Call);
-- If it is a recursive call then call the internal procedure that
-- verifies Subprogram_Variant contract (if present and enabled).
-- Detecting calls to subprogram aliases is necessary for recursive
-- calls in instances of generic subprograms, where the renaming of
-- the current subprogram is called.
if Is_Subprogram (Subp)
and then not Is_Ignored_Ghost_Entity (Subp)
and then Same_Or_Aliased_Subprograms (Subp, Current_Scope)
then
Check_Subprogram_Variant;
end if;
-- Verify that the actuals do not share storage. This check must be done
-- on the caller side rather that inside the subprogram to avoid issues
-- of parameter passing.
if Check_Aliasing_Of_Parameters then
Apply_Parameter_Aliasing_Checks (Call_Node, Subp);
end if;
-- If the subprogram is a renaming, or if it is inherited, replace it in
-- the call with the name of the actual subprogram being called. If this
-- is a dispatching call, the run-time decides what to call. The Alias
-- attribute does not apply to entries.
if Nkind (Call_Node) /= N_Entry_Call_Statement
and then No (Controlling_Argument (Call_Node))
and then Present (Parent_Subp)
and then not Is_Direct_Deep_Call (Subp)
then
if Present (Inherited_From_Formal (Subp)) then
Parent_Subp := Inherited_From_Formal (Subp);
else
Parent_Subp := Ultimate_Alias (Parent_Subp);
end if;
-- The below setting of Entity is suspect, see F109-018 discussion???
Set_Entity (Name (Call_Node), Parent_Subp);
-- Move this check to sem???
if Is_Abstract_Subprogram (Parent_Subp)
and then not In_Instance
then
Error_Msg_NE
("cannot call abstract subprogram &!",
Name (Call_Node), Parent_Subp);
end if;
-- Inspect all formals of derived subprogram Subp. Compare parameter
-- types with the parent subprogram and check whether an actual may
-- need a type conversion to the corresponding formal of the parent
-- subprogram.
-- Not clear whether intrinsic subprograms need such conversions. ???
if not Is_Intrinsic_Subprogram (Parent_Subp)
or else Is_Generic_Instance (Parent_Subp)
then
declare
procedure Convert (Act : Node_Id; Typ : Entity_Id);
-- Rewrite node Act as a type conversion of Act to Typ. Analyze
-- and resolve the newly generated construct.
-------------
-- Convert --
-------------
procedure Convert (Act : Node_Id; Typ : Entity_Id) is
begin
Rewrite (Act, OK_Convert_To (Typ, Act));
Analyze_And_Resolve (Act, Typ);
end Convert;
-- Local variables
Actual_Typ : Entity_Id;
Formal_Typ : Entity_Id;
Parent_Typ : Entity_Id;
begin
Actual := First_Actual (Call_Node);
Formal := First_Formal (Subp);
Parent_Formal := First_Formal (Parent_Subp);
while Present (Formal) loop
Actual_Typ := Etype (Actual);
Formal_Typ := Etype (Formal);
Parent_Typ := Etype (Parent_Formal);
-- For an IN parameter of a scalar type, the derived formal
-- type and parent formal type differ, and the parent formal
-- type and actual type do not match statically.
if Is_Scalar_Type (Formal_Typ)
and then Ekind (Formal) = E_In_Parameter
and then Formal_Typ /= Parent_Typ
and then
not Subtypes_Statically_Match (Parent_Typ, Actual_Typ)
and then not Raises_Constraint_Error (Actual)
then
Convert (Actual, Parent_Typ);
-- For access types, the parent formal type and actual type
-- differ.
elsif Is_Access_Type (Formal_Typ)
and then Base_Type (Parent_Typ) /= Base_Type (Actual_Typ)
then
if Ekind (Formal) /= E_In_Parameter then
Convert (Actual, Parent_Typ);
elsif Ekind (Parent_Typ) = E_Anonymous_Access_Type
and then Designated_Type (Parent_Typ) /=
Designated_Type (Actual_Typ)
and then not Is_Controlling_Formal (Formal)
then
-- This unchecked conversion is not necessary unless
-- inlining is enabled, because in that case the type
-- mismatch may become visible in the body about to be
-- inlined.
Rewrite (Actual,
Unchecked_Convert_To (Parent_Typ, Actual));
Analyze_And_Resolve (Actual, Parent_Typ);
end if;
-- If there is a change of representation, then generate a
-- warning, and do the change of representation.
elsif not Has_Compatible_Representation
(Target_Type => Formal_Typ,
Operand_Type => Parent_Typ)
then
Error_Msg_N
("??change of representation required", Actual);
Convert (Actual, Parent_Typ);
-- For array and record types, the parent formal type and
-- derived formal type have different sizes or pragma Pack
-- status.
elsif ((Is_Array_Type (Formal_Typ)
and then Is_Array_Type (Parent_Typ))
or else
(Is_Record_Type (Formal_Typ)
and then Is_Record_Type (Parent_Typ)))
and then Known_Esize (Formal_Typ)
and then Known_Esize (Parent_Typ)
and then
(Esize (Formal_Typ) /= Esize (Parent_Typ)
or else Has_Pragma_Pack (Formal_Typ) /=
Has_Pragma_Pack (Parent_Typ))
then
Convert (Actual, Parent_Typ);
end if;
Next_Actual (Actual);
Next_Formal (Formal);
Next_Formal (Parent_Formal);
end loop;
end;
end if;
Orig_Subp := Subp;
Subp := Parent_Subp;
end if;
-- Deal with case where call is an explicit dereference
if Nkind (Name (Call_Node)) = N_Explicit_Dereference then
-- Handle case of access to protected subprogram type
if Is_Access_Protected_Subprogram_Type
(Base_Type (Etype (Prefix (Name (Call_Node)))))
then
-- If this is a call through an access to protected operation, the
-- prefix has the form (object'address, operation'access). Rewrite
-- as a for other protected calls: the object is the 1st parameter
-- of the list of actuals.
declare
Call : Node_Id;
Parm : List_Id;
Nam : Node_Id;
Obj : Node_Id;
Ptr : constant Node_Id := Prefix (Name (Call_Node));
T : constant Entity_Id :=
Equivalent_Type (Base_Type (Etype (Ptr)));
D_T : constant Entity_Id :=
Designated_Type (Base_Type (Etype (Ptr)));
begin
Obj :=
Make_Selected_Component (Loc,
Prefix => Unchecked_Convert_To (T, Ptr),
Selector_Name =>
New_Occurrence_Of (First_Entity (T), Loc));
Nam :=
Make_Selected_Component (Loc,
Prefix => Unchecked_Convert_To (T, Ptr),
Selector_Name =>
New_Occurrence_Of (Next_Entity (First_Entity (T)), Loc));
Nam :=
Make_Explicit_Dereference (Loc,
Prefix => Nam);
if Present (Parameter_Associations (Call_Node)) then
Parm := Parameter_Associations (Call_Node);
else
Parm := New_List;
end if;
Prepend (Obj, Parm);
if Etype (D_T) = Standard_Void_Type then
Call :=
Make_Procedure_Call_Statement (Loc,
Name => Nam,
Parameter_Associations => Parm);
else
Call :=
Make_Function_Call (Loc,
Name => Nam,
Parameter_Associations => Parm);
end if;
Set_First_Named_Actual (Call, First_Named_Actual (Call_Node));
Set_Etype (Call, Etype (D_T));
-- We do not re-analyze the call to avoid infinite recursion.
-- We analyze separately the prefix and the object, and set
-- the checks on the prefix that would otherwise be emitted
-- when resolving a call.
Rewrite (Call_Node, Call);
Analyze (Nam);
Apply_Access_Check (Nam);
Analyze (Obj);
return;
end;
end if;
end if;
-- If this is a call to an intrinsic subprogram, then perform the
-- appropriate expansion to the corresponding tree node and we
-- are all done (since after that the call is gone).
-- In the case where the intrinsic is to be processed by the back end,
-- the call to Expand_Intrinsic_Call will do nothing, which is fine,
-- since the idea in this case is to pass the call unchanged. If the
-- intrinsic is an inherited unchecked conversion, and the derived type
-- is the target type of the conversion, we must retain it as the return
-- type of the expression. Otherwise the expansion below, which uses the
-- parent operation, will yield the wrong type.
if Is_Intrinsic_Subprogram (Subp) then
Expand_Intrinsic_Call (Call_Node, Subp);
if Nkind (Call_Node) = N_Unchecked_Type_Conversion
and then Parent_Subp /= Orig_Subp
and then Etype (Parent_Subp) /= Etype (Orig_Subp)
then
Set_Etype (Call_Node, Etype (Orig_Subp));
end if;
return;
end if;
if Ekind (Subp) in E_Function | E_Procedure then
-- We perform a simple optimization on calls for To_Address by
-- replacing them with an unchecked conversion. Not only is this
-- efficient, but it also avoids order of elaboration problems when
-- address clauses are inlined (address expression elaborated at the
-- wrong point).
-- We perform this optimization regardless of whether we are in the
-- main unit or in a unit in the context of the main unit, to ensure
-- that the generated tree is the same in both cases, for CodePeer
-- use.
if Is_RTE (Subp, RE_To_Address) then
Rewrite (Call_Node,
Unchecked_Convert_To
(RTE (RE_Address), Relocate_Node (First_Actual (Call_Node))));
return;
-- A call to a null procedure is replaced by a null statement, but we
-- are not allowed to ignore possible side effects of the call, so we
-- make sure that actuals are evaluated.
-- We also suppress this optimization for GNATcoverage.
elsif Is_Null_Procedure (Subp)
and then not Opt.Suppress_Control_Flow_Optimizations
then
Actual := First_Actual (Call_Node);
while Present (Actual) loop
Remove_Side_Effects (Actual);
Next_Actual (Actual);
end loop;
Rewrite (Call_Node, Make_Null_Statement (Loc));
return;
end if;
-- Handle inlining. No action needed if the subprogram is not inlined
if not Is_Inlined (Subp) then
null;
-- Front-end inlining of expression functions (performed also when
-- back-end inlining is enabled).
elsif Is_Inlinable_Expression_Function (Subp) then
Rewrite
(Call_Node, New_Copy (Expression_Of_Expression_Function (Subp)));
Analyze (Call_Node);
return;
-- Handle front-end inlining
elsif not Back_End_Inlining then
Inlined_Subprogram : declare
Bod : Node_Id;
Must_Inline : Boolean := False;
Spec : constant Node_Id := Unit_Declaration_Node (Subp);
begin
-- Verify that the body to inline has already been seen, and
-- that if the body is in the current unit the inlining does
-- not occur earlier. This avoids order-of-elaboration problems
-- in the back end.
-- This should be documented in sinfo/einfo ???
if No (Spec)
or else Nkind (Spec) /= N_Subprogram_Declaration
or else No (Body_To_Inline (Spec))
then
Must_Inline := False;
-- If this an inherited function that returns a private type,
-- do not inline if the full view is an unconstrained array,
-- because such calls cannot be inlined.
elsif Present (Orig_Subp)
and then Is_Array_Type (Etype (Orig_Subp))
and then not Is_Constrained (Etype (Orig_Subp))
then
Must_Inline := False;
elsif In_Unfrozen_Instance (Scope (Subp)) then
Must_Inline := False;
else
Bod := Body_To_Inline (Spec);
if (In_Extended_Main_Code_Unit (Call_Node)
or else In_Extended_Main_Code_Unit (Parent (Call_Node))
or else Has_Pragma_Inline_Always (Subp))
and then (not In_Same_Extended_Unit (Sloc (Bod), Loc)
or else
Earlier_In_Extended_Unit (Sloc (Bod), Loc))
then
Must_Inline := True;
-- If we are compiling a package body that is not the main
-- unit, it must be for inlining/instantiation purposes,
-- in which case we inline the call to insure that the same
-- temporaries are generated when compiling the body by
-- itself. Otherwise link errors can occur.
-- If the function being called is itself in the main unit,
-- we cannot inline, because there is a risk of double
-- elaboration and/or circularity: the inlining can make
-- visible a private entity in the body of the main unit,
-- that gigi will see before its sees its proper definition.
elsif not In_Extended_Main_Code_Unit (Call_Node)
and then In_Package_Body
then
Must_Inline := not In_Extended_Main_Source_Unit (Subp);
-- Inline calls to _postconditions when generating C code
elsif Modify_Tree_For_C
and then In_Same_Extended_Unit (Sloc (Bod), Loc)
and then Chars (Name (Call_Node)) = Name_uPostconditions
then
Must_Inline := True;
end if;
end if;
if Must_Inline then
Expand_Inlined_Call (Call_Node, Subp, Orig_Subp);
else
-- Let the back end handle it
Add_Inlined_Body (Subp, Call_Node);
if Front_End_Inlining
and then Nkind (Spec) = N_Subprogram_Declaration
and then In_Extended_Main_Code_Unit (Call_Node)
and then No (Body_To_Inline (Spec))
and then not Has_Completion (Subp)
and then In_Same_Extended_Unit (Sloc (Spec), Loc)
then
Cannot_Inline
("cannot inline& (body not seen yet)?",
Call_Node, Subp);
end if;
end if;
end Inlined_Subprogram;
-- Front-end expansion of simple functions returning unconstrained
-- types (see Check_And_Split_Unconstrained_Function). Note that the
-- case of a simple renaming (Body_To_Inline in N_Entity below, see
-- also Build_Renamed_Body) cannot be expanded here because this may
-- give rise to order-of-elaboration issues for the types of the
-- parameters of the subprogram, if any.
elsif Present (Unit_Declaration_Node (Subp))
and then Nkind (Unit_Declaration_Node (Subp)) =
N_Subprogram_Declaration
and then Present (Body_To_Inline (Unit_Declaration_Node (Subp)))
and then
Nkind (Body_To_Inline (Unit_Declaration_Node (Subp))) not in
N_Entity
then
Expand_Inlined_Call (Call_Node, Subp, Orig_Subp);
-- Back-end inlining either if optimization is enabled or the call is
-- required to be inlined.
elsif Optimization_Level > 0
or else Has_Pragma_Inline_Always (Subp)
then
Add_Inlined_Body (Subp, Call_Node);
end if;
end if;
-- Check for protected subprogram. This is either an intra-object call,
-- or a protected function call. Protected procedure calls are rewritten
-- as entry calls and handled accordingly.
-- In Ada 2005, this may be an indirect call to an access parameter that
-- is an access_to_subprogram. In that case the anonymous type has a
-- scope that is a protected operation, but the call is a regular one.
-- In either case do not expand call if subprogram is eliminated.
Scop := Scope (Subp);
if Nkind (Call_Node) /= N_Entry_Call_Statement
and then Is_Protected_Type (Scop)
and then Ekind (Subp) /= E_Subprogram_Type
and then not Is_Eliminated (Subp)
then
-- If the call is an internal one, it is rewritten as a call to the
-- corresponding unprotected subprogram.
Expand_Protected_Subprogram_Call (Call_Node, Subp, Scop);
end if;
-- Functions returning controlled objects need special attention. If
-- the return type is limited, then the context is initialization and
-- different processing applies. If the call is to a protected function,
-- the expansion above will call Expand_Call recursively. Otherwise the
-- function call is transformed into a temporary which obtains the
-- result from the secondary stack.
if Needs_Finalization (Etype (Subp)) then
if not Is_Build_In_Place_Function_Call (Call_Node)
and then
(No (First_Formal (Subp))
or else
not Is_Concurrent_Record_Type (Etype (First_Formal (Subp))))
then
Expand_Ctrl_Function_Call (Call_Node);
-- Build-in-place function calls which appear in anonymous contexts
-- need a transient scope to ensure the proper finalization of the
-- intermediate result after its use.
elsif Is_Build_In_Place_Function_Call (Call_Node)
and then Nkind (Parent (Unqual_Conv (Call_Node))) in
N_Attribute_Reference
| N_Function_Call
| N_Indexed_Component
| N_Object_Renaming_Declaration
| N_Procedure_Call_Statement
| N_Selected_Component
| N_Slice
and then
(Ekind (Current_Scope) /= E_Loop
or else Nkind (Parent (Call_Node)) /= N_Function_Call
or else not Is_Build_In_Place_Function_Call
(Parent (Call_Node)))
then
Establish_Transient_Scope (Call_Node, Manage_Sec_Stack => True);
end if;
end if;
end Expand_Call_Helper;
-------------------------------
-- Expand_Ctrl_Function_Call --
-------------------------------
procedure Expand_Ctrl_Function_Call (N : Node_Id) is
function Is_Element_Reference (N : Node_Id) return Boolean;
-- Determine whether node N denotes a reference to an Ada 2012 container
-- element.
--------------------------
-- Is_Element_Reference --
--------------------------
function Is_Element_Reference (N : Node_Id) return Boolean is
Ref : constant Node_Id := Original_Node (N);
begin
-- Analysis marks an element reference by setting the generalized
-- indexing attribute of an indexed component before the component
-- is rewritten into a function call.
return
Nkind (Ref) = N_Indexed_Component
and then Present (Generalized_Indexing (Ref));
end Is_Element_Reference;
-- Start of processing for Expand_Ctrl_Function_Call
begin
-- Optimization, if the returned value (which is on the sec-stack) is
-- returned again, no need to copy/readjust/finalize, we can just pass
-- the value thru (see Expand_N_Simple_Return_Statement), and thus no
-- attachment is needed.
if Nkind (Parent (N)) = N_Simple_Return_Statement then
return;
end if;
-- Resolution is now finished, make sure we don't start analysis again
-- because of the duplication.
Set_Analyzed (N);
-- A function which returns a controlled object uses the secondary
-- stack. Rewrite the call into a temporary which obtains the result of
-- the function using 'reference.
Remove_Side_Effects (N);
-- The side effect removal of the function call produced a temporary.
-- When the context is a case expression, if expression, or expression
-- with actions, the lifetime of the temporary must be extended to match
-- that of the context. Otherwise the function result will be finalized
-- too early and affect the result of the expression. To prevent this
-- unwanted effect, the temporary should not be considered for clean up
-- actions by the general finalization machinery.
-- Exception to this rule are references to Ada 2012 container elements.
-- Such references must be finalized at the end of each iteration of the
-- related quantified expression, otherwise the container will remain
-- busy.
if Nkind (N) = N_Explicit_Dereference
and then Within_Case_Or_If_Expression (N)
and then not Is_Element_Reference (N)
then
Set_Is_Ignored_Transient (Entity (Prefix (N)));
end if;
end Expand_Ctrl_Function_Call;
----------------------------------------
-- Expand_N_Extended_Return_Statement --
----------------------------------------
-- If there is a Handled_Statement_Sequence, we rewrite this:
-- return Result : T := <expression> do
-- <handled_seq_of_stms>
-- end return;
-- to be:
-- declare
-- Result : T := <expression>;
-- begin
-- <handled_seq_of_stms>
-- return Result;
-- end;
-- Otherwise (no Handled_Statement_Sequence), we rewrite this:
-- return Result : T := <expression>;
-- to be:
-- return <expression>;
-- unless it's build-in-place or there's no <expression>, in which case
-- we generate:
-- declare
-- Result : T := <expression>;
-- begin
-- return Result;
-- end;
-- Note that this case could have been written by the user as an extended
-- return statement, or could have been transformed to this from a simple
-- return statement.
-- That is, we need to have a reified return object if there are statements
-- (which might refer to it) or if we're doing build-in-place (so we can
-- set its address to the final resting place or if there is no expression
-- (in which case default initial values might need to be set)).
procedure Expand_N_Extended_Return_Statement (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
function Build_Heap_Or_Pool_Allocator
(Temp_Id : Entity_Id;
Temp_Typ : Entity_Id;
Func_Id : Entity_Id;
Ret_Typ : Entity_Id;
Alloc_Expr : Node_Id) return Node_Id;
-- Create the statements necessary to allocate a return object on the
-- heap or user-defined storage pool. The object may need finalization
-- actions depending on the return type.
--
-- * Controlled case
--
-- if BIPfinalizationmaster = null then
-- Temp_Id := <Alloc_Expr>;
-- else
-- declare
-- type Ptr_Typ is access Ret_Typ;
-- for Ptr_Typ'Storage_Pool use
-- Base_Pool (BIPfinalizationmaster.all).all;
-- Local : Ptr_Typ;
--
-- begin
-- procedure Allocate (...) is
-- begin
-- System.Storage_Pools.Subpools.Allocate_Any (...);
-- end Allocate;
--
-- Local := <Alloc_Expr>;
-- Temp_Id := Temp_Typ (Local);
-- end;
-- end if;
--
-- * Non-controlled case
--
-- Temp_Id := <Alloc_Expr>;
--
-- Temp_Id is the temporary which is used to reference the internally
-- created object in all allocation forms. Temp_Typ is the type of the
-- temporary. Func_Id is the enclosing function. Ret_Typ is the return
-- type of Func_Id. Alloc_Expr is the actual allocator.
function Move_Activation_Chain (Func_Id : Entity_Id) return Node_Id;
-- Construct a call to System.Tasking.Stages.Move_Activation_Chain
-- with parameters:
-- From current activation chain
-- To activation chain passed in by the caller
-- New_Master master passed in by the caller
--
-- Func_Id is the entity of the function where the extended return
-- statement appears.
----------------------------------
-- Build_Heap_Or_Pool_Allocator --
----------------------------------
function Build_Heap_Or_Pool_Allocator
(Temp_Id : Entity_Id;
Temp_Typ : Entity_Id;
Func_Id : Entity_Id;
Ret_Typ : Entity_Id;
Alloc_Expr : Node_Id) return Node_Id
is
begin
pragma Assert (Is_Build_In_Place_Function (Func_Id));
-- Processing for objects that require finalization actions
if Needs_Finalization (Ret_Typ) then
declare
Decls : constant List_Id := New_List;
Fin_Mas_Id : constant Entity_Id :=
Build_In_Place_Formal
(Func_Id, BIP_Finalization_Master);
Orig_Expr : constant Node_Id :=
New_Copy_Tree
(Source => Alloc_Expr,
Scopes_In_EWA_OK => True);
Stmts : constant List_Id := New_List;
Desig_Typ : Entity_Id;
Local_Id : Entity_Id;
Pool_Id : Entity_Id;
Ptr_Typ : Entity_Id;
begin
-- Generate:
-- Pool_Id renames Base_Pool (BIPfinalizationmaster.all).all;
Pool_Id := Make_Temporary (Loc, 'P');
Append_To (Decls,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Pool_Id,
Subtype_Mark =>
New_Occurrence_Of (RTE (RE_Root_Storage_Pool), Loc),
Name =>
Make_Explicit_Dereference (Loc,
Prefix =>
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Base_Pool), Loc),
Parameter_Associations => New_List (
Make_Explicit_Dereference (Loc,
Prefix =>
New_Occurrence_Of (Fin_Mas_Id, Loc)))))));
-- Create an access type which uses the storage pool of the
-- caller's master. This additional type is necessary because
-- the finalization master cannot be associated with the type
-- of the temporary. Otherwise the secondary stack allocation
-- will fail.
Desig_Typ := Ret_Typ;
-- Ensure that the build-in-place machinery uses a fat pointer
-- when allocating an unconstrained array on the heap. In this
-- case the result object type is a constrained array type even
-- though the function type is unconstrained.
if Ekind (Desig_Typ) = E_Array_Subtype then
Desig_Typ := Base_Type (Desig_Typ);
end if;
-- Generate:
-- type Ptr_Typ is access Desig_Typ;
Ptr_Typ := Make_Temporary (Loc, 'P');
Append_To (Decls,
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Ptr_Typ,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
Subtype_Indication =>
New_Occurrence_Of (Desig_Typ, Loc))));
-- Perform minor decoration in order to set the master and the
-- storage pool attributes.
Mutate_Ekind (Ptr_Typ, E_Access_Type);
Set_Finalization_Master (Ptr_Typ, Fin_Mas_Id);
Set_Associated_Storage_Pool (Ptr_Typ, Pool_Id);
-- Create the temporary, generate:
-- Local_Id : Ptr_Typ;
Local_Id := Make_Temporary (Loc, 'T');
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Local_Id,
Object_Definition =>
New_Occurrence_Of (Ptr_Typ, Loc)));
-- Allocate the object, generate:
-- Local_Id := <Alloc_Expr>;
Append_To (Stmts,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Local_Id, Loc),
Expression => Alloc_Expr));
-- Generate:
-- Temp_Id := Temp_Typ (Local_Id);
Append_To (Stmts,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Temp_Id, Loc),
Expression =>
Unchecked_Convert_To (Temp_Typ,
New_Occurrence_Of (Local_Id, Loc))));
-- Wrap the allocation in a block. This is further conditioned
-- by checking the caller finalization master at runtime. A
-- null value indicates a non-existent master, most likely due
-- to a Finalize_Storage_Only allocation.
-- Generate:
-- if BIPfinalizationmaster = null then
-- Temp_Id := <Orig_Expr>;
-- else
-- declare
-- <Decls>
-- begin
-- <Stmts>
-- end;
-- end if;
return
Make_If_Statement (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd => New_Occurrence_Of (Fin_Mas_Id, Loc),
Right_Opnd => Make_Null (Loc)),
Then_Statements => New_List (
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Temp_Id, Loc),
Expression => Orig_Expr)),
Else_Statements => New_List (
Make_Block_Statement (Loc,
Declarations => Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stmts))));
end;
-- For all other cases, generate:
-- Temp_Id := <Alloc_Expr>;
else
return
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Temp_Id, Loc),
Expression => Alloc_Expr);
end if;
end Build_Heap_Or_Pool_Allocator;
---------------------------
-- Move_Activation_Chain --
---------------------------
function Move_Activation_Chain (Func_Id : Entity_Id) return Node_Id is
begin
return
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Move_Activation_Chain), Loc),
Parameter_Associations => New_List (
-- Source chain
Make_Attribute_Reference (Loc,
Prefix => Make_Identifier (Loc, Name_uChain),
Attribute_Name => Name_Unrestricted_Access),
-- Destination chain
New_Occurrence_Of
(Build_In_Place_Formal (Func_Id, BIP_Activation_Chain), Loc),
-- New master
New_Occurrence_Of
(Build_In_Place_Formal (Func_Id, BIP_Task_Master), Loc)));
end Move_Activation_Chain;
-- Local variables
Func_Id : constant Entity_Id :=
Return_Applies_To (Return_Statement_Entity (N));
Is_BIP_Func : constant Boolean :=
Is_Build_In_Place_Function (Func_Id);
Ret_Obj_Id : constant Entity_Id :=
First_Entity (Return_Statement_Entity (N));
Ret_Obj_Decl : constant Node_Id := Parent (Ret_Obj_Id);
Ret_Typ : constant Entity_Id := Etype (Func_Id);
Exp : Node_Id;
HSS : Node_Id;
Result : Node_Id;
Stmts : List_Id;
Return_Stmt : Node_Id := Empty;
-- Force initialization to facilitate static analysis
-- Start of processing for Expand_N_Extended_Return_Statement
begin
-- Given that functionality of interface thunks is simple (just displace
-- the pointer to the object) they are always handled by means of
-- simple return statements.
pragma Assert (not Is_Thunk (Current_Subprogram));
if Nkind (Ret_Obj_Decl) = N_Object_Declaration then
Exp := Expression (Ret_Obj_Decl);
-- Assert that if F says "return R : T := G(...) do..."
-- then F and G are both b-i-p, or neither b-i-p.
if Nkind (Exp) = N_Function_Call then
pragma Assert (Ekind (Current_Subprogram) = E_Function);
pragma Assert
(Is_Build_In_Place_Function (Current_Subprogram) =
Is_Build_In_Place_Function_Call (Exp));
null;
end if;
-- Ada 2005 (AI95-344): If the result type is class-wide, then insert
-- a check that the level of the return expression's underlying type
-- is not deeper than the level of the master enclosing the function.
-- AI12-043: The check is made immediately after the return object
-- is created.
if Present (Exp) and then Is_Class_Wide_Type (Ret_Typ) then
Apply_CW_Accessibility_Check (Exp, Func_Id);
end if;
else
Exp := Empty;
end if;
HSS := Handled_Statement_Sequence (N);
-- If the returned object needs finalization actions, the function must
-- perform the appropriate cleanup should it fail to return. The state
-- of the function itself is tracked through a flag which is coupled
-- with the scope finalizer. There is one flag per each return object
-- in case of multiple returns.
if Is_BIP_Func and then Needs_Finalization (Etype (Ret_Obj_Id)) then
declare
Flag_Decl : Node_Id;
Flag_Id : Entity_Id;
Func_Bod : Node_Id;
begin
-- Recover the function body
Func_Bod := Unit_Declaration_Node (Func_Id);
if Nkind (Func_Bod) = N_Subprogram_Declaration then
Func_Bod := Parent (Parent (Corresponding_Body (Func_Bod)));
end if;
if Nkind (Func_Bod) = N_Function_Specification then
Func_Bod := Parent (Func_Bod); -- one more level for child units
end if;
pragma Assert (Nkind (Func_Bod) = N_Subprogram_Body);
-- Create a flag to track the function state
Flag_Id := Make_Temporary (Loc, 'F');
Set_Status_Flag_Or_Transient_Decl (Ret_Obj_Id, Flag_Id);
-- Insert the flag at the beginning of the function declarations,
-- generate:
-- Fnn : Boolean := False;
Flag_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Flag_Id,
Object_Definition =>
New_Occurrence_Of (Standard_Boolean, Loc),
Expression =>
New_Occurrence_Of (Standard_False, Loc));
Prepend_To (Declarations (Func_Bod), Flag_Decl);
Analyze (Flag_Decl);
end;
end if;
-- Build a simple_return_statement that returns the return object when
-- there is a statement sequence, or no expression, or the analysis of
-- the return object declaration generated extra actions, or the result
-- will be built in place. Note however that we currently do this for
-- all composite cases, even though they are not built in place.
if Present (HSS)
or else No (Exp)
or else List_Length (Return_Object_Declarations (N)) > 1
or else Is_Composite_Type (Ret_Typ)
then
if No (HSS) then
Stmts := New_List;
-- If the extended return has a handled statement sequence, then wrap
-- it in a block and use the block as the first statement.
else
Stmts := New_List (
Make_Block_Statement (Loc,
Declarations => New_List,
Handled_Statement_Sequence => HSS));
end if;
-- If the result type contains tasks, we call Move_Activation_Chain.
-- Later, the cleanup code will call Complete_Master, which will
-- terminate any unactivated tasks belonging to the return statement
-- master. But Move_Activation_Chain updates their master to be that
-- of the caller, so they will not be terminated unless the return
-- statement completes unsuccessfully due to exception, abort, goto,
-- or exit. As a formality, we test whether the function requires the
-- result to be built in place, though that's necessarily true for
-- the case of result types with task parts.
if Is_BIP_Func and then Has_Task (Ret_Typ) then
-- The return expression is an aggregate for a complex type which
-- contains tasks. This particular case is left unexpanded since
-- the regular expansion would insert all temporaries and
-- initialization code in the wrong block.
if Nkind (Exp) = N_Aggregate then
Expand_N_Aggregate (Exp);
end if;
-- Do not move the activation chain if the return object does not
-- contain tasks.
if Has_Task (Etype (Ret_Obj_Id)) then
Append_To (Stmts, Move_Activation_Chain (Func_Id));
end if;
end if;
-- Update the state of the function right before the object is
-- returned.
if Is_BIP_Func and then Needs_Finalization (Etype (Ret_Obj_Id)) then
declare
Flag_Id : constant Entity_Id :=
Status_Flag_Or_Transient_Decl (Ret_Obj_Id);
begin
-- Generate:
-- Fnn := True;
Append_To (Stmts,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Flag_Id, Loc),
Expression => New_Occurrence_Of (Standard_True, Loc)));
end;
end if;
-- Build a simple_return_statement that returns the return object
Return_Stmt :=
Make_Simple_Return_Statement (Loc,
Expression => New_Occurrence_Of (Ret_Obj_Id, Loc));
Append_To (Stmts, Return_Stmt);
HSS := Make_Handled_Sequence_Of_Statements (Loc, Stmts);
end if;
-- Case where we build a return statement block
if Present (HSS) then
Result :=
Make_Block_Statement (Loc,
Declarations => Return_Object_Declarations (N),
Handled_Statement_Sequence => HSS);
-- We set the entity of the new block statement to be that of the
-- return statement. This is necessary so that various fields, such
-- as Finalization_Chain_Entity carry over from the return statement
-- to the block. Note that this block is unusual, in that its entity
-- is an E_Return_Statement rather than an E_Block.
Set_Identifier
(Result, New_Occurrence_Of (Return_Statement_Entity (N), Loc));
-- If the object decl was already rewritten as a renaming, then we
-- don't want to do the object allocation and transformation of
-- the return object declaration to a renaming. This case occurs
-- when the return object is initialized by a call to another
-- build-in-place function, and that function is responsible for
-- the allocation of the return object.
if Is_BIP_Func
and then Nkind (Ret_Obj_Decl) = N_Object_Renaming_Declaration
then
pragma Assert
(Nkind (Original_Node (Ret_Obj_Decl)) = N_Object_Declaration
and then
-- It is a regular BIP object declaration
(Is_Build_In_Place_Function_Call
(Expression (Original_Node (Ret_Obj_Decl)))
-- It is a BIP object declaration that displaces the pointer
-- to the object to reference a converted interface type.
or else
Present (Unqual_BIP_Iface_Function_Call
(Expression (Original_Node (Ret_Obj_Decl))))));
-- Return the build-in-place result by reference
Set_By_Ref (Return_Stmt);
elsif Is_BIP_Func then
-- Locate the implicit access parameter associated with the
-- caller-supplied return object and convert the return
-- statement's return object declaration to a renaming of a
-- dereference of the access parameter. If the return object's
-- declaration includes an expression that has not already been
-- expanded as separate assignments, then add an assignment
-- statement to ensure the return object gets initialized.
-- declare
-- Result : T [:= <expression>];
-- begin
-- ...
-- is converted to
-- declare
-- Result : T renames FuncRA.all;
-- [Result := <expression;]
-- begin
-- ...
declare
Ret_Obj_Expr : constant Node_Id := Expression (Ret_Obj_Decl);
Ret_Obj_Typ : constant Entity_Id := Etype (Ret_Obj_Id);
Init_Assignment : Node_Id := Empty;
Obj_Acc_Formal : Entity_Id;
Obj_Acc_Deref : Node_Id;
Obj_Alloc_Formal : Entity_Id;
begin
-- Build-in-place results must be returned by reference
Set_By_Ref (Return_Stmt);
-- Retrieve the implicit access parameter passed by the caller
Obj_Acc_Formal :=
Build_In_Place_Formal (Func_Id, BIP_Object_Access);
-- If the return object's declaration includes an expression
-- and the declaration isn't marked as No_Initialization, then
-- we need to generate an assignment to the object and insert
-- it after the declaration before rewriting it as a renaming
-- (otherwise we'll lose the initialization). The case where
-- the result type is an interface (or class-wide interface)
-- is also excluded because the context of the function call
-- must be unconstrained, so the initialization will always
-- be done as part of an allocator evaluation (storage pool
-- or secondary stack), never to a constrained target object
-- passed in by the caller. Besides the assignment being
-- unneeded in this case, it avoids problems with trying to
-- generate a dispatching assignment when the return expression
-- is a nonlimited descendant of a limited interface (the
-- interface has no assignment operation).
if Present (Ret_Obj_Expr)
and then not No_Initialization (Ret_Obj_Decl)
and then not Is_Interface (Ret_Obj_Typ)
then
Init_Assignment :=
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Ret_Obj_Id, Loc),
Expression =>
New_Copy_Tree
(Source => Ret_Obj_Expr,
Scopes_In_EWA_OK => True));
Set_Etype (Name (Init_Assignment), Etype (Ret_Obj_Id));
Set_Assignment_OK (Name (Init_Assignment));
Set_No_Ctrl_Actions (Init_Assignment);
Set_Parent (Name (Init_Assignment), Init_Assignment);
Set_Parent (Expression (Init_Assignment), Init_Assignment);
Set_Expression (Ret_Obj_Decl, Empty);
if Is_Class_Wide_Type (Etype (Ret_Obj_Id))
and then not Is_Class_Wide_Type
(Etype (Expression (Init_Assignment)))
then
Rewrite (Expression (Init_Assignment),
Make_Type_Conversion (Loc,
Subtype_Mark =>
New_Occurrence_Of (Etype (Ret_Obj_Id), Loc),
Expression =>
Relocate_Node (Expression (Init_Assignment))));
end if;
-- In the case of functions where the calling context can
-- determine the form of allocation needed, initialization
-- is done with each part of the if statement that handles
-- the different forms of allocation (this is true for
-- unconstrained, tagged, and controlled result subtypes).
if not Needs_BIP_Alloc_Form (Func_Id) then
Insert_After (Ret_Obj_Decl, Init_Assignment);
end if;
end if;
-- When the function's subtype is unconstrained, a run-time
-- test may be needed to decide the form of allocation to use
-- for the return object. The function has an implicit formal
-- parameter indicating this. If the BIP_Alloc_Form formal has
-- the value one, then the caller has passed access to an
-- existing object for use as the return object. If the value
-- is two, then the return object must be allocated on the
-- secondary stack. Otherwise, the object must be allocated in
-- a storage pool. We generate an if statement to test the
-- implicit allocation formal and initialize a local access
-- value appropriately, creating allocators in the secondary
-- stack and global heap cases. The special formal also exists
-- and must be tested when the function has a tagged result,
-- even when the result subtype is constrained, because in
-- general such functions can be called in dispatching contexts
-- and must be handled similarly to functions with a class-wide
-- result.
if Needs_BIP_Alloc_Form (Func_Id) then
Obj_Alloc_Formal :=
Build_In_Place_Formal (Func_Id, BIP_Alloc_Form);
declare
Pool_Id : constant Entity_Id :=
Make_Temporary (Loc, 'P');
Alloc_Obj_Id : Entity_Id;
Alloc_Obj_Decl : Node_Id;
Alloc_If_Stmt : Node_Id;
Guard_Except : Node_Id;
Heap_Allocator : Node_Id;
Pool_Decl : Node_Id;
Pool_Allocator : Node_Id;
Ptr_Type_Decl : Node_Id;
Ref_Type : Entity_Id;
SS_Allocator : Node_Id;
begin
-- Create an access type designating the function's
-- result subtype.
Ref_Type := Make_Temporary (Loc, 'A');
Ptr_Type_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 (Ret_Obj_Typ, Loc)));
Insert_Before (Ret_Obj_Decl, Ptr_Type_Decl);
-- Create an access object that will be initialized to an
-- access value denoting the return object, either coming
-- from an implicit access value passed in by the caller
-- or from the result of an allocator.
Alloc_Obj_Id := Make_Temporary (Loc, 'R');
Set_Etype (Alloc_Obj_Id, Ref_Type);
Alloc_Obj_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Alloc_Obj_Id,
Object_Definition =>
New_Occurrence_Of (Ref_Type, Loc));
Insert_Before (Ret_Obj_Decl, Alloc_Obj_Decl);
-- Create allocators for both the secondary stack and
-- global heap. If there's an initialization expression,
-- then create these as initialized allocators.
if Present (Ret_Obj_Expr)
and then not No_Initialization (Ret_Obj_Decl)
then
-- Always use the type of the expression for the
-- qualified expression, rather than the result type.
-- In general we cannot always use the result type
-- for the allocator, because the expression might be
-- of a specific type, such as in the case of an
-- aggregate or even a nonlimited object when the
-- result type is a limited class-wide interface type.
Heap_Allocator :=
Make_Allocator (Loc,
Expression =>
Make_Qualified_Expression (Loc,
Subtype_Mark =>
New_Occurrence_Of
(Etype (Ret_Obj_Expr), Loc),
Expression =>
New_Copy_Tree
(Source => Ret_Obj_Expr,
Scopes_In_EWA_OK => True)));
else
-- If the function returns a class-wide type we cannot
-- use the return type for the allocator. Instead we
-- use the type of the expression, which must be an
-- aggregate of a definite type.
if Is_Class_Wide_Type (Ret_Obj_Typ) then
Heap_Allocator :=
Make_Allocator (Loc,
Expression =>
New_Occurrence_Of
(Etype (Ret_Obj_Expr), Loc));
else
Heap_Allocator :=
Make_Allocator (Loc,
Expression =>
New_Occurrence_Of (Ret_Obj_Typ, Loc));
end if;
-- If the object requires default initialization then
-- that will happen later following the elaboration of
-- the object renaming. If we don't turn it off here
-- then the object will be default initialized twice.
Set_No_Initialization (Heap_Allocator);
end if;
-- Set the flag indicating that the allocator came from
-- a build-in-place return statement, so we can avoid
-- adjusting the allocated object. Note that this flag
-- will be inherited by the copies made below.
Set_Alloc_For_BIP_Return (Heap_Allocator);
-- The Pool_Allocator is just like the Heap_Allocator,
-- except we set Storage_Pool and Procedure_To_Call so
-- it will use the user-defined storage pool.
Pool_Allocator :=
New_Copy_Tree
(Source => Heap_Allocator,
Scopes_In_EWA_OK => True);
pragma Assert (Alloc_For_BIP_Return (Pool_Allocator));
-- Do not generate the renaming of the build-in-place
-- pool parameter on ZFP because the parameter is not
-- created in the first place.
if RTE_Available (RE_Root_Storage_Pool_Ptr) then
Pool_Decl :=
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Pool_Id,
Subtype_Mark =>
New_Occurrence_Of
(RTE (RE_Root_Storage_Pool), Loc),
Name =>
Make_Explicit_Dereference (Loc,
New_Occurrence_Of
(Build_In_Place_Formal
(Func_Id, BIP_Storage_Pool), Loc)));
Set_Storage_Pool (Pool_Allocator, Pool_Id);
Set_Procedure_To_Call
(Pool_Allocator, RTE (RE_Allocate_Any));
else
Pool_Decl := Make_Null_Statement (Loc);
end if;
-- If the No_Allocators restriction is active, then only
-- an allocator for secondary stack allocation is needed.
-- It's OK for such allocators to have Comes_From_Source
-- set to False, because gigi knows not to flag them as
-- being a violation of No_Implicit_Heap_Allocations.
if Restriction_Active (No_Allocators) then
SS_Allocator := Heap_Allocator;
Heap_Allocator := Make_Null (Loc);
Pool_Allocator := Make_Null (Loc);
-- Otherwise the heap and pool allocators may be needed,
-- so we make another allocator for secondary stack
-- allocation.
else
SS_Allocator :=
New_Copy_Tree
(Source => Heap_Allocator,
Scopes_In_EWA_OK => True);
pragma Assert (Alloc_For_BIP_Return (SS_Allocator));
-- The heap and pool allocators are marked as
-- Comes_From_Source since they correspond to an
-- explicit user-written allocator (that is, it will
-- only be executed on behalf of callers that call the
-- function as initialization for such an allocator).
-- Prevents errors when No_Implicit_Heap_Allocations
-- is in force.
Set_Comes_From_Source (Heap_Allocator, True);
Set_Comes_From_Source (Pool_Allocator, True);
end if;
-- The allocator is returned on the secondary stack
Check_Restriction (No_Secondary_Stack, N);
Set_Storage_Pool (SS_Allocator, RTE (RE_SS_Pool));
Set_Procedure_To_Call
(SS_Allocator, RTE (RE_SS_Allocate));
-- The allocator is returned on the secondary stack,
-- so indicate that the function return, as well as
-- all blocks that encloses the allocator, must not
-- release it. The flags must be set now because
-- the decision to use the secondary stack is done
-- very late in the course of expanding the return
-- statement, past the point where these flags are
-- normally set.
Set_Uses_Sec_Stack (Func_Id);
Set_Uses_Sec_Stack (Return_Statement_Entity (N));
Set_Sec_Stack_Needed_For_Return
(Return_Statement_Entity (N));
Set_Enclosing_Sec_Stack_Return (N);
-- Guard against poor expansion on the caller side by
-- using a raise statement to catch out-of-range values
-- of formal parameter BIP_Alloc_Form.
if Exceptions_OK then
Guard_Except :=
Make_Raise_Program_Error (Loc,
Reason => PE_Build_In_Place_Mismatch);
else
Guard_Except := Make_Null_Statement (Loc);
end if;
-- Create an if statement to test the BIP_Alloc_Form
-- formal and initialize the access object to either the
-- BIP_Object_Access formal (BIP_Alloc_Form =
-- Caller_Allocation), the result of allocating the
-- object in the secondary stack (BIP_Alloc_Form =
-- Secondary_Stack), or else an allocator to create the
-- return object in the heap or user-defined pool
-- (BIP_Alloc_Form = Global_Heap or User_Storage_Pool).
-- ??? An unchecked type conversion must be made in the
-- case of assigning the access object formal to the
-- local access object, because a normal conversion would
-- be illegal in some cases (such as converting access-
-- to-unconstrained to access-to-constrained), but the
-- the unchecked conversion will presumably fail to work
-- right in just such cases. It's not clear at all how to
-- handle this. ???
Alloc_If_Stmt :=
Make_If_Statement (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd =>
New_Occurrence_Of (Obj_Alloc_Formal, Loc),
Right_Opnd =>
Make_Integer_Literal (Loc,
UI_From_Int (BIP_Allocation_Form'Pos
(Caller_Allocation)))),
Then_Statements => New_List (
Make_Assignment_Statement (Loc,
Name =>
New_Occurrence_Of (Alloc_Obj_Id, Loc),
Expression =>
Unchecked_Convert_To
(Ref_Type,
New_Occurrence_Of (Obj_Acc_Formal, Loc)))),
Elsif_Parts => New_List (
Make_Elsif_Part (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd =>
New_Occurrence_Of (Obj_Alloc_Formal, Loc),
Right_Opnd =>
Make_Integer_Literal (Loc,
UI_From_Int (BIP_Allocation_Form'Pos
(Secondary_Stack)))),
Then_Statements => New_List (
Make_Assignment_Statement (Loc,
Name =>
New_Occurrence_Of (Alloc_Obj_Id, Loc),
Expression => SS_Allocator))),
Make_Elsif_Part (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd =>
New_Occurrence_Of (Obj_Alloc_Formal, Loc),
Right_Opnd =>
Make_Integer_Literal (Loc,
UI_From_Int (BIP_Allocation_Form'Pos
(Global_Heap)))),
Then_Statements => New_List (
Build_Heap_Or_Pool_Allocator
(Temp_Id => Alloc_Obj_Id,
Temp_Typ => Ref_Type,
Func_Id => Func_Id,
Ret_Typ => Ret_Obj_Typ,
Alloc_Expr => Heap_Allocator))),
-- ???If all is well, we can put the following
-- 'elsif' in the 'else', but this is a useful
-- self-check in case caller and callee don't agree
-- on whether BIPAlloc and so on should be passed.
Make_Elsif_Part (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd =>
New_Occurrence_Of (Obj_Alloc_Formal, Loc),
Right_Opnd =>
Make_Integer_Literal (Loc,
UI_From_Int (BIP_Allocation_Form'Pos
(User_Storage_Pool)))),
Then_Statements => New_List (
Pool_Decl,
Build_Heap_Or_Pool_Allocator
(Temp_Id => Alloc_Obj_Id,
Temp_Typ => Ref_Type,
Func_Id => Func_Id,
Ret_Typ => Ret_Obj_Typ,
Alloc_Expr => Pool_Allocator)))),
-- Raise Program_Error if it's none of the above;
-- this is a compiler bug.
Else_Statements => New_List (Guard_Except));
-- If a separate initialization assignment was created
-- earlier, append that following the assignment of the
-- implicit access formal to the access object, to ensure
-- that the return object is initialized in that case. In
-- this situation, the target of the assignment must be
-- rewritten to denote a dereference of the access to the
-- return object passed in by the caller.
if Present (Init_Assignment) then
Rewrite (Name (Init_Assignment),
Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (Alloc_Obj_Id, Loc)));
pragma Assert
(Assignment_OK
(Original_Node (Name (Init_Assignment))));
Set_Assignment_OK (Name (Init_Assignment));
Set_Etype (Name (Init_Assignment), Etype (Ret_Obj_Id));
Append_To
(Then_Statements (Alloc_If_Stmt), Init_Assignment);
end if;
Insert_Before (Ret_Obj_Decl, Alloc_If_Stmt);
-- Remember the local access object for use in the
-- dereference of the renaming created below.
Obj_Acc_Formal := Alloc_Obj_Id;
end;
-- When the function's subtype is unconstrained and a run-time
-- test is not needed, we nevertheless need to build the return
-- using the function's result subtype.
elsif not Is_Constrained (Underlying_Type (Etype (Func_Id)))
then
declare
Alloc_Obj_Id : Entity_Id;
Alloc_Obj_Decl : Node_Id;
Ptr_Type_Decl : Node_Id;
Ref_Type : Entity_Id;
begin
-- Create an access type designating the function's
-- result subtype.
Ref_Type := Make_Temporary (Loc, 'A');
Ptr_Type_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 (Ret_Obj_Typ, Loc)));
Insert_Before (Ret_Obj_Decl, Ptr_Type_Decl);
-- Create an access object initialized to the conversion
-- of the implicit access value passed in by the caller.
Alloc_Obj_Id := Make_Temporary (Loc, 'R');
Set_Etype (Alloc_Obj_Id, Ref_Type);
-- See the ??? comment a few lines above about the use of
-- an unchecked conversion here.
Alloc_Obj_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Alloc_Obj_Id,
Object_Definition =>
New_Occurrence_Of (Ref_Type, Loc),
Expression =>
Unchecked_Convert_To
(Ref_Type,
New_Occurrence_Of (Obj_Acc_Formal, Loc)));
Insert_Before (Ret_Obj_Decl, Alloc_Obj_Decl);
-- Remember the local access object for use in the
-- dereference of the renaming created below.
Obj_Acc_Formal := Alloc_Obj_Id;
end;
end if;
-- Replace the return object declaration with a renaming of a
-- dereference of the access value designating the return
-- object.
Obj_Acc_Deref :=
Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (Obj_Acc_Formal, Loc));
Rewrite (Ret_Obj_Decl,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Ret_Obj_Id,
Access_Definition => Empty,
Subtype_Mark => New_Occurrence_Of (Ret_Obj_Typ, Loc),
Name => Obj_Acc_Deref));
Set_Renamed_Object (Ret_Obj_Id, Obj_Acc_Deref);
end;
end if;
-- Case where we do not need to build a block. But we're about to drop
-- Return_Object_Declarations on the floor, so assert that it contains
-- only the return object declaration.
else pragma Assert (List_Length (Return_Object_Declarations (N)) = 1);
-- Build simple_return_statement that returns the expression directly
Return_Stmt := Make_Simple_Return_Statement (Loc, Expression => Exp);
Result := Return_Stmt;
end if;
-- Set the flag to prevent infinite recursion
Set_Comes_From_Extended_Return_Statement (Return_Stmt);
Set_Return_Statement (Ret_Obj_Id, Return_Stmt);
Rewrite (N, Result);
-- AI12-043: The checks of 6.5(8.1/3) and 6.5(21/3) are made immediately
-- before an object is returned. A predicate that applies to the return
-- subtype is checked immediately before an object is returned.
-- Suppress access checks to avoid generating extra checks for b-i-p.
Analyze (N, Suppress => Access_Check);
end Expand_N_Extended_Return_Statement;
----------------------------
-- Expand_N_Function_Call --
----------------------------
procedure Expand_N_Function_Call (N : Node_Id) is
begin
Expand_Call (N);
end Expand_N_Function_Call;
---------------------------------------
-- Expand_N_Procedure_Call_Statement --
---------------------------------------
procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
begin
Expand_Call (N);
end Expand_N_Procedure_Call_Statement;
------------------------------------
-- Expand_N_Return_When_Statement --
------------------------------------
procedure Expand_N_Return_When_Statement (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
begin
Rewrite (N,
Make_If_Statement (Loc,
Condition => Condition (N),
Then_Statements => New_List (
Make_Simple_Return_Statement (Loc,
Expression => Expression (N)))));
Analyze (N);
end Expand_N_Return_When_Statement;
--------------------------------------
-- Expand_N_Simple_Return_Statement --
--------------------------------------
procedure Expand_N_Simple_Return_Statement (N : Node_Id) is
begin
-- Defend against previous errors (i.e. the return statement calls a
-- function that is not available in configurable runtime).
if Present (Expression (N))
and then Nkind (Expression (N)) = N_Empty
then
Check_Error_Detected;
return;
end if;
-- Distinguish the function and non-function cases:
case Ekind (Return_Applies_To (Return_Statement_Entity (N))) is
when E_Function
| E_Generic_Function
=>
Expand_Simple_Function_Return (N);
when E_Entry
| E_Entry_Family
| E_Generic_Procedure
| E_Procedure
| E_Return_Statement
=>
Expand_Non_Function_Return (N);
when others =>
raise Program_Error;
end case;
exception
when RE_Not_Available =>
return;
end Expand_N_Simple_Return_Statement;
------------------------------
-- Expand_N_Subprogram_Body --
------------------------------
-- Add dummy push/pop label nodes at start and end to clear any local
-- exception indications if local-exception-to-goto optimization is active.
-- Add return statement if last statement in body is not a return statement
-- (this makes things easier on Gigi which does not want to have to handle
-- a missing return).
-- Add call to Activate_Tasks if body is a task activator
-- Deal with possible detection of infinite recursion
-- Eliminate body completely if convention stubbed
-- Encode entity names within body, since we will not need to reference
-- these entities any longer in the front end.
-- Initialize scalar out parameters if Initialize/Normalize_Scalars
-- Reset Pure indication if any parameter has root type System.Address
-- or has any parameters of limited types, where limited means that the
-- run-time view is limited (i.e. the full type is limited).
-- Wrap thread body
procedure Expand_N_Subprogram_Body (N : Node_Id) is
Body_Id : constant Entity_Id := Defining_Entity (N);
HSS : constant Node_Id := Handled_Statement_Sequence (N);
Loc : constant Source_Ptr := Sloc (N);
procedure Add_Return (Spec_Id : Entity_Id; Stmts : List_Id);
-- Append a return statement to the statement sequence Stmts if the last
-- statement is not already a return or a goto statement. Note that the
-- latter test is not critical, it does not matter if we add a few extra
-- returns, since they get eliminated anyway later on. Spec_Id denotes
-- the corresponding spec of the subprogram body.
----------------
-- Add_Return --
----------------
procedure Add_Return (Spec_Id : Entity_Id; Stmts : List_Id) is
Last_Stmt : Node_Id;
Loc : Source_Ptr;
Stmt : Node_Id;
begin
-- Get last statement, ignoring any Pop_xxx_Label nodes, which are
-- not relevant in this context since they are not executable.
Last_Stmt := Last (Stmts);
while Nkind (Last_Stmt) in N_Pop_xxx_Label loop
Prev (Last_Stmt);
end loop;
-- Now insert return unless last statement is a transfer
if not Is_Transfer (Last_Stmt) then
-- The source location for the return is the end label of the
-- procedure if present. Otherwise use the sloc of the last
-- statement in the list. If the list comes from a generated
-- exception handler and we are not debugging generated code,
-- all the statements within the handler are made invisible
-- to the debugger.
if Nkind (Parent (Stmts)) = N_Exception_Handler
and then not Comes_From_Source (Parent (Stmts))
then
Loc := Sloc (Last_Stmt);
elsif Present (End_Label (HSS)) then
Loc := Sloc (End_Label (HSS));
else
Loc := Sloc (Last_Stmt);
end if;
-- Append return statement, and set analyzed manually. We can't
-- call Analyze on this return since the scope is wrong.
-- Note: it almost works to push the scope and then do the Analyze
-- call, but something goes wrong in some weird cases and it is
-- not worth worrying about ???
Stmt := Make_Simple_Return_Statement (Loc);
-- The return statement is handled properly, and the call to the
-- postcondition, inserted below, does not require information
-- from the body either. However, that call is analyzed in the
-- enclosing scope, and an elaboration check might improperly be
-- added to it. A guard in Sem_Elab is needed to prevent that
-- spurious check, see Check_Elab_Call.
Append_To (Stmts, Stmt);
Set_Analyzed (Stmt);
-- Call the _Postconditions procedure if the related subprogram
-- has contract assertions that need to be verified on exit.
-- Also, mark the successful return to signal that postconditions
-- need to be evaluated when finalization occurs by setting
-- Return_Success_For_Postcond to be True.
if Ekind (Spec_Id) = E_Procedure
and then Present (Postconditions_Proc (Spec_Id))
then
-- Generate:
--
-- Return_Success_For_Postcond := True;
-- if Postcond_Enabled then
-- _postconditions;
-- end if;
Insert_Action (Stmt,
Make_Assignment_Statement (Loc,
Name =>
New_Occurrence_Of
(Get_Return_Success_For_Postcond (Spec_Id), Loc),
Expression => New_Occurrence_Of (Standard_True, Loc)));
-- Wrap the call to _postconditions within a test of the
-- Postcond_Enabled flag to delay postcondition evaluation
-- until after finalization when required.
Insert_Action (Stmt,
Make_If_Statement (Loc,
Condition =>
New_Occurrence_Of (Get_Postcond_Enabled (Spec_Id), Loc),
Then_Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of
(Postconditions_Proc (Spec_Id), Loc)))));
end if;
-- Ada 2022 (AI12-0279): append the call to 'Yield unless this is
-- a generic subprogram (since in such case it will be added to
-- the instantiations).
if Has_Yield_Aspect (Spec_Id)
and then Ekind (Spec_Id) /= E_Generic_Procedure
and then RTE_Available (RE_Yield)
then
Insert_Action (Stmt,
Make_Procedure_Call_Statement (Loc,
New_Occurrence_Of (RTE (RE_Yield), Loc)));
end if;
end if;
end Add_Return;
-- Local variables
Except_H : Node_Id;
L : List_Id;
Spec_Id : Entity_Id;
-- Start of processing for Expand_N_Subprogram_Body
begin
if Present (Corresponding_Spec (N)) then
Spec_Id := Corresponding_Spec (N);
else
Spec_Id := Body_Id;
end if;
-- If this is a Pure function which has any parameters whose root type
-- is System.Address, reset the Pure indication.
-- This check is also performed when the subprogram is frozen, but we
-- repeat it on the body so that the indication is consistent, and so
-- it applies as well to bodies without separate specifications.
if Is_Pure (Spec_Id)
and then Is_Subprogram (Spec_Id)
and then not Has_Pragma_Pure_Function (Spec_Id)
then
Check_Function_With_Address_Parameter (Spec_Id);
if Spec_Id /= Body_Id then
Set_Is_Pure (Body_Id, Is_Pure (Spec_Id));
end if;
end if;
-- Set L to either the list of declarations if present, or to the list
-- of statements if no declarations are present. This is used to insert
-- new stuff at the start.
if Is_Non_Empty_List (Declarations (N)) then
L := Declarations (N);
else
L := Statements (HSS);
end if;
-- If local-exception-to-goto optimization active, insert dummy push
-- statements at start, and dummy pop statements at end, but inhibit
-- this if we have No_Exception_Handlers, since they are useless and
-- interfere with analysis, e.g. by CodePeer. We also don't need these
-- if we're unnesting subprograms because the only purpose of these
-- nodes is to ensure we don't set a label in one subprogram and branch
-- to it in another.
if (Debug_Flag_Dot_G
or else Restriction_Active (No_Exception_Propagation))
and then not Restriction_Active (No_Exception_Handlers)
and then not CodePeer_Mode
and then not Unnest_Subprogram_Mode
and then Is_Non_Empty_List (L)
then
declare
FS : constant Node_Id := First (L);
FL : constant Source_Ptr := Sloc (FS);
LS : Node_Id;
LL : Source_Ptr;
begin
-- LS points to either last statement, if statements are present
-- or to the last declaration if there are no statements present.
-- It is the node after which the pop's are generated.
if Is_Non_Empty_List (Statements (HSS)) then
LS := Last (Statements (HSS));
else
LS := Last (L);
end if;
LL := Sloc (LS);
Insert_List_Before_And_Analyze (FS, New_List (
Make_Push_Constraint_Error_Label (FL),
Make_Push_Program_Error_Label (FL),
Make_Push_Storage_Error_Label (FL)));
Insert_List_After_And_Analyze (LS, New_List (
Make_Pop_Constraint_Error_Label (LL),
Make_Pop_Program_Error_Label (LL),
Make_Pop_Storage_Error_Label (LL)));
end;
end if;
-- Initialize any scalar OUT args if Initialize/Normalize_Scalars
if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
declare
F : Entity_Id;
A : Node_Id;
begin
-- Loop through formals
F := First_Formal (Spec_Id);
while Present (F) loop
if Is_Scalar_Type (Etype (F))
and then Ekind (F) = E_Out_Parameter
then
Check_Restriction (No_Default_Initialization, F);
-- Insert the initialization. We turn off validity checks
-- for this assignment, since we do not want any check on
-- the initial value itself (which may well be invalid).
-- Predicate checks are disabled as well (RM 6.4.1 (13/3))
A :=
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (F, Loc),
Expression => Get_Simple_Init_Val (Etype (F), N));
Set_Suppress_Assignment_Checks (A);
Insert_Before_And_Analyze (First (L),
A, Suppress => Validity_Check);
end if;
Next_Formal (F);
end loop;
end;
end if;
-- Clear out statement list for stubbed procedure
if Present (Corresponding_Spec (N)) then
Set_Elaboration_Flag (N, Spec_Id);
if Convention (Spec_Id) = Convention_Stubbed
or else Is_Eliminated (Spec_Id)
then
Set_Declarations (N, Empty_List);
Set_Handled_Statement_Sequence (N,
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Make_Null_Statement (Loc))));
return;
end if;
end if;
-- Create a set of discriminals for the next protected subprogram body
if Is_List_Member (N)
and then Present (Parent (List_Containing (N)))
and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
and then Present (Next_Protected_Operation (N))
then
Set_Discriminals (Parent (Base_Type (Scope (Spec_Id))));
end if;
-- Returns_By_Ref flag is normally set when the subprogram is frozen but
-- subprograms with no specs are not frozen.
Compute_Returns_By_Ref (Spec_Id);
-- For a procedure, we add a return for all possible syntactic ends of
-- the subprogram.
if Ekind (Spec_Id) in E_Procedure | E_Generic_Procedure then
Add_Return (Spec_Id, Statements (HSS));
if Present (Exception_Handlers (HSS)) then
Except_H := First_Non_Pragma (Exception_Handlers (HSS));
while Present (Except_H) loop
Add_Return (Spec_Id, Statements (Except_H));
Next_Non_Pragma (Except_H);
end loop;
end if;
-- For a function, we must deal with the case where there is at least
-- one missing return. What we do is to wrap the entire body of the
-- function in a block:
-- begin
-- ...
-- end;
-- becomes
-- begin
-- begin
-- ...
-- end;
-- raise Program_Error;
-- end;
-- This approach is necessary because the raise must be signalled to the
-- caller, not handled by any local handler (RM 6.4(11)).
-- Note: we do not need to analyze the constructed sequence here, since
-- it has no handler, and an attempt to analyze the handled statement
-- sequence twice is risky in various ways (e.g. the issue of expanding
-- cleanup actions twice).
elsif Has_Missing_Return (Spec_Id) then
declare
Hloc : constant Source_Ptr := Sloc (HSS);
Blok : constant Node_Id :=
Make_Block_Statement (Hloc,
Handled_Statement_Sequence => HSS);
Rais : constant Node_Id :=
Make_Raise_Program_Error (Hloc,
Reason => PE_Missing_Return);
begin
Set_Handled_Statement_Sequence (N,
Make_Handled_Sequence_Of_Statements (Hloc,
Statements => New_List (Blok, Rais)));
Push_Scope (Spec_Id);
Analyze (Blok);
Analyze (Rais);
Pop_Scope;
end;
end if;
-- If subprogram contains a parameterless recursive call, then we may
-- have an infinite recursion, so see if we can generate code to check
-- for this possibility if storage checks are not suppressed.
if Ekind (Spec_Id) = E_Procedure
and then Has_Recursive_Call (Spec_Id)
and then not Storage_Checks_Suppressed (Spec_Id)
then
Detect_Infinite_Recursion (N, Spec_Id);
end if;
-- Set to encode entity names in package body before gigi is called
Qualify_Entity_Names (N);
-- If the body belongs to a nonabstract library-level source primitive
-- of a tagged type, install an elaboration check which ensures that a
-- dispatching call targeting the primitive will not execute the body
-- without it being previously elaborated.
Install_Primitive_Elaboration_Check (N);
end Expand_N_Subprogram_Body;
-----------------------------------
-- Expand_N_Subprogram_Body_Stub --
-----------------------------------
procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
Bod : Node_Id;
begin
if Present (Corresponding_Body (N)) then
Bod := Unit_Declaration_Node (Corresponding_Body (N));
-- The body may have been expanded already when it is analyzed
-- through the subunit node. Do no expand again: it interferes
-- with the construction of unnesting tables when generating C.
if not Analyzed (Bod) then
Expand_N_Subprogram_Body (Bod);
end if;
-- Add full qualification to entities that may be created late
-- during unnesting.
Qualify_Entity_Names (N);
end if;
end Expand_N_Subprogram_Body_Stub;
-------------------------------------
-- Expand_N_Subprogram_Declaration --
-------------------------------------
-- If the declaration appears within a protected body, it is a private
-- operation of the protected type. We must create the corresponding
-- protected subprogram an associated formals. For a normal protected
-- operation, this is done when expanding the protected type declaration.
-- If the declaration is for a null procedure, emit null body
procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Subp : constant Entity_Id := Defining_Entity (N);
-- Local variables
Scop : constant Entity_Id := Scope (Subp);
Prot_Bod : Node_Id;
Prot_Decl : Node_Id;
Prot_Id : Entity_Id;
Typ : Entity_Id;
begin
-- Deal with case of protected subprogram. Do not generate protected
-- operation if operation is flagged as eliminated.
if Is_List_Member (N)
and then Present (Parent (List_Containing (N)))
and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
and then Is_Protected_Type (Scop)
then
if No (Protected_Body_Subprogram (Subp))
and then not Is_Eliminated (Subp)
then
Prot_Decl :=
Make_Subprogram_Declaration (Loc,
Specification =>
Build_Protected_Sub_Specification
(N, Scop, Unprotected_Mode));
-- The protected subprogram is declared outside of the protected
-- body. Given that the body has frozen all entities so far, we
-- analyze the subprogram and perform freezing actions explicitly.
-- including the generation of an explicit freeze node, to ensure
-- that gigi has the proper order of elaboration.
-- If the body is a subunit, the insertion point is before the
-- stub in the parent.
Prot_Bod := Parent (List_Containing (N));
if Nkind (Parent (Prot_Bod)) = N_Subunit then
Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
end if;
Insert_Before (Prot_Bod, Prot_Decl);
Prot_Id := Defining_Unit_Name (Specification (Prot_Decl));
Set_Has_Delayed_Freeze (Prot_Id);
Push_Scope (Scope (Scop));
Analyze (Prot_Decl);
Freeze_Before (N, Prot_Id);
Set_Protected_Body_Subprogram (Subp, Prot_Id);
Pop_Scope;
end if;
-- Ada 2005 (AI-348): Generate body for a null procedure. In most
-- cases this is superfluous because calls to it will be automatically
-- inlined, but we definitely need the body if preconditions for the
-- procedure are present, or if performing coverage analysis.
elsif Nkind (Specification (N)) = N_Procedure_Specification
and then Null_Present (Specification (N))
then
declare
Bod : constant Node_Id := Body_To_Inline (N);
begin
Set_Has_Completion (Subp, False);
Append_Freeze_Action (Subp, Bod);
-- The body now contains raise statements, so calls to it will
-- not be inlined.
Set_Is_Inlined (Subp, False);
end;
end if;
-- When generating C code, transform a function that returns a
-- constrained array type into a procedure with an out parameter
-- that carries the return value.
-- We skip this transformation for unchecked conversions, since they
-- are not needed by the C generator (and this also produces cleaner
-- output).
Typ := Get_Fullest_View (Etype (Subp));
if Transform_Function_Array
and then Nkind (Specification (N)) = N_Function_Specification
and then Is_Array_Type (Typ)
and then Is_Constrained (Typ)
and then not Is_Unchecked_Conversion_Instance (Subp)
then
Build_Procedure_Form (N);
end if;
end Expand_N_Subprogram_Declaration;
--------------------------------
-- Expand_Non_Function_Return --
--------------------------------
procedure Expand_Non_Function_Return (N : Node_Id) is
pragma Assert (No (Expression (N)));
Loc : constant Source_Ptr := Sloc (N);
Scope_Id : Entity_Id := Return_Applies_To (Return_Statement_Entity (N));
Kind : constant Entity_Kind := Ekind (Scope_Id);
Call : Node_Id;
Acc_Stat : Node_Id;
Goto_Stat : Node_Id;
Lab_Node : Node_Id;
begin
-- Call the _Postconditions procedure if the related subprogram has
-- contract assertions that need to be verified on exit.
-- Also, mark the successful return to signal that postconditions need
-- to be evaluated when finalization occurs.
if Ekind (Scope_Id) in E_Entry | E_Entry_Family | E_Procedure
and then Present (Postconditions_Proc (Scope_Id))
then
-- Generate:
--
-- Return_Success_For_Postcond := True;
-- if Postcond_Enabled then
-- _postconditions;
-- end if;
Insert_Action (N,
Make_Assignment_Statement (Loc,
Name =>
New_Occurrence_Of
(Get_Return_Success_For_Postcond (Scope_Id), Loc),
Expression => New_Occurrence_Of (Standard_True, Loc)));
-- Wrap the call to _postconditions within a test of the
-- Postcond_Enabled flag to delay postcondition evaluation until
-- after finalization when required.
Insert_Action (N,
Make_If_Statement (Loc,
Condition =>
New_Occurrence_Of (Get_Postcond_Enabled (Scope_Id), Loc),
Then_Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of
(Postconditions_Proc (Scope_Id), Loc)))));
end if;
-- Ada 2022 (AI12-0279)
if Has_Yield_Aspect (Scope_Id)
and then RTE_Available (RE_Yield)
then
Insert_Action (N,
Make_Procedure_Call_Statement (Loc,
New_Occurrence_Of (RTE (RE_Yield), Loc)));
end if;
-- If it is a return from a procedure do no extra steps
if Kind = E_Procedure or else Kind = E_Generic_Procedure then
return;
-- If it is a nested return within an extended one, replace it with a
-- return of the previously declared return object.
elsif Kind = E_Return_Statement then
Rewrite (N,
Make_Simple_Return_Statement (Loc,
Expression =>
New_Occurrence_Of (First_Entity (Scope_Id), Loc)));
Set_Comes_From_Extended_Return_Statement (N);
Set_Return_Statement_Entity (N, Scope_Id);
Expand_Simple_Function_Return (N);
return;
end if;
pragma Assert (Is_Entry (Scope_Id));
-- Look at the enclosing block to see whether the return is from an
-- accept statement or an entry body.
for J in reverse 0 .. Scope_Stack.Last loop
Scope_Id := Scope_Stack.Table (J).Entity;
exit when Is_Concurrent_Type (Scope_Id);
end loop;
-- If it is a return from accept statement it is expanded as call to
-- RTS Complete_Rendezvous and a goto to the end of the accept body.
-- (cf : Expand_N_Accept_Statement, Expand_N_Selective_Accept,
-- Expand_N_Accept_Alternative in exp_ch9.adb)
if Is_Task_Type (Scope_Id) then
Call :=
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (RTE (RE_Complete_Rendezvous), Loc));
Insert_Before (N, Call);
-- why not insert actions here???
Analyze (Call);
Acc_Stat := Parent (N);
while Nkind (Acc_Stat) /= N_Accept_Statement loop
Acc_Stat := Parent (Acc_Stat);
end loop;
Lab_Node := Last (Statements
(Handled_Statement_Sequence (Acc_Stat)));
Goto_Stat := Make_Goto_Statement (Loc,
Name => New_Occurrence_Of
(Entity (Identifier (Lab_Node)), Loc));
Set_Analyzed (Goto_Stat);
Rewrite (N, Goto_Stat);
Analyze (N);
-- If it is a return from an entry body, put a Complete_Entry_Body call
-- in front of the return.
elsif Is_Protected_Type (Scope_Id) then
Call :=
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Complete_Entry_Body), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of
(Find_Protection_Object (Current_Scope), Loc),
Attribute_Name => Name_Unchecked_Access)));
Insert_Before (N, Call);
Analyze (Call);
end if;
end Expand_Non_Function_Return;
---------------------------------------
-- Expand_Protected_Object_Reference --
---------------------------------------
function Expand_Protected_Object_Reference
(N : Node_Id;
Scop : Entity_Id) return Node_Id
is
Loc : constant Source_Ptr := Sloc (N);
Corr : Entity_Id;
Rec : Node_Id;
Param : Entity_Id;
Proc : Entity_Id;
begin
Rec := Make_Identifier (Loc, Name_uObject);
Set_Etype (Rec, Corresponding_Record_Type (Scop));
-- Find enclosing protected operation, and retrieve its first parameter,
-- which denotes the enclosing protected object. If the enclosing
-- operation is an entry, we are immediately within the protected body,
-- and we can retrieve the object from the service entries procedure. A
-- barrier function has the same signature as an entry. A barrier
-- function is compiled within the protected object, but unlike
-- protected operations its never needs locks, so that its protected
-- body subprogram points to itself.
Proc := Current_Scope;
while Present (Proc)
and then Scope (Proc) /= Scop
loop
Proc := Scope (Proc);
end loop;
Corr := Protected_Body_Subprogram (Proc);
if No (Corr) then
-- Previous error left expansion incomplete.
-- Nothing to do on this call.
return Empty;
end if;
Param :=
Defining_Identifier
(First (Parameter_Specifications (Parent (Corr))));
if Is_Subprogram (Proc) and then Proc /= Corr then
-- Protected function or procedure
Set_Entity (Rec, Param);
-- Rec is a reference to an entity which will not be in scope when
-- the call is reanalyzed, and needs no further analysis.
Set_Analyzed (Rec);
else
-- Entry or barrier function for entry body. The first parameter of
-- the entry body procedure is pointer to the object. We create a
-- local variable of the proper type, duplicating what is done to
-- define _object later on.
declare
Decls : List_Id;
Obj_Ptr : constant Entity_Id := Make_Temporary (Loc, 'T');
begin
Decls := New_List (
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Obj_Ptr,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
Subtype_Indication =>
New_Occurrence_Of
(Corresponding_Record_Type (Scop), Loc))));
Insert_Actions (N, Decls);
Freeze_Before (N, Obj_Ptr);
Rec :=
Make_Explicit_Dereference (Loc,
Prefix =>
Unchecked_Convert_To (Obj_Ptr,
New_Occurrence_Of (Param, Loc)));
-- Analyze new actual. Other actuals in calls are already analyzed
-- and the list of actuals is not reanalyzed after rewriting.
Set_Parent (Rec, N);
Analyze (Rec);
end;
end if;
return Rec;
end Expand_Protected_Object_Reference;
--------------------------------------
-- Expand_Protected_Subprogram_Call --
--------------------------------------
procedure Expand_Protected_Subprogram_Call
(N : Node_Id;
Subp : Entity_Id;
Scop : Entity_Id)
is
Rec : Node_Id;
procedure Expand_Internal_Init_Call;
-- A call to an operation of the type may occur in the initialization
-- of a private component. In that case the prefix of the call is an
-- entity name and the call is treated as internal even though it
-- appears in code outside of the protected type.
procedure Freeze_Called_Function;
-- If it is a function call it can appear in elaboration code and
-- the called entity must be frozen before the call. This must be
-- done before the call is expanded, as the expansion may rewrite it
-- to something other than a call (e.g. a temporary initialized in a
-- transient block).
-------------------------------
-- Expand_Internal_Init_Call --
-------------------------------
procedure Expand_Internal_Init_Call is
begin
-- If the context is a protected object (rather than a protected
-- type) the call itself is bound to raise program_error because
-- the protected body will not have been elaborated yet. This is
-- diagnosed subsequently in Sem_Elab.
Freeze_Called_Function;
-- The target of the internal call is the first formal of the
-- enclosing initialization procedure.
Rec := New_Occurrence_Of (First_Formal (Current_Scope), Sloc (N));
Build_Protected_Subprogram_Call (N,
Name => Name (N),
Rec => Rec,
External => False);
Analyze (N);
Resolve (N, Etype (Subp));
end Expand_Internal_Init_Call;
----------------------------
-- Freeze_Called_Function --
----------------------------
procedure Freeze_Called_Function is
begin
if Ekind (Subp) = E_Function then
Freeze_Expression (Name (N));
end if;
end Freeze_Called_Function;
-- Start of processing for Expand_Protected_Subprogram_Call
begin
-- If the protected object is not an enclosing scope, this is an inter-
-- object function call. Inter-object procedure calls are expanded by
-- Exp_Ch9.Build_Simple_Entry_Call. The call is intra-object only if the
-- subprogram being called is in the protected body being compiled, and
-- if the protected object in the call is statically the enclosing type.
-- The object may be a component of some other data structure, in which
-- case this must be handled as an inter-object call.
if not In_Open_Scopes (Scop)
or else Is_Entry_Wrapper (Current_Scope)
or else not Is_Entity_Name (Name (N))
then
if Nkind (Name (N)) = N_Selected_Component then
Rec := Prefix (Name (N));
elsif Nkind (Name (N)) = N_Indexed_Component then
Rec := Prefix (Prefix (Name (N)));
-- If this is a call within an entry wrapper, it appears within a
-- precondition that calls another primitive of the synchronized
-- type. The target object of the call is the first actual on the
-- wrapper. Note that this is an external call, because the wrapper
-- is called outside of the synchronized object. This means that
-- an entry call to an entry with preconditions involves two
-- synchronized operations.
elsif Ekind (Current_Scope) = E_Procedure
and then Is_Entry_Wrapper (Current_Scope)
then
Rec := New_Occurrence_Of (First_Entity (Current_Scope), Sloc (N));
-- A default parameter of a protected operation may be a call to
-- a protected function of the type. This appears as an internal
-- call in the profile of the operation, but if the context is an
-- external call we must convert the call into an external one,
-- using the protected object that is the target, so that:
-- Prot.P (F)
-- is transformed into
-- Prot.P (Prot.F)
elsif Nkind (Parent (N)) = N_Procedure_Call_Statement
and then Nkind (Name (Parent (N))) = N_Selected_Component
and then Is_Protected_Type (Etype (Prefix (Name (Parent (N)))))
and then Is_Entity_Name (Name (N))
and then Scope (Entity (Name (N))) =
Etype (Prefix (Name (Parent (N))))
then
Rewrite (Name (N),
Make_Selected_Component (Sloc (N),
Prefix => New_Copy_Tree (Prefix (Name (Parent (N)))),
Selector_Name => Relocate_Node (Name (N))));
Analyze_And_Resolve (N);
return;
else
-- If the context is the initialization procedure for a protected
-- type, the call is legal because the called entity must be a
-- function of that enclosing type, and this is treated as an
-- internal call.
pragma Assert
(Is_Entity_Name (Name (N)) and then Inside_Init_Proc);
Expand_Internal_Init_Call;
return;
end if;
Freeze_Called_Function;
Build_Protected_Subprogram_Call (N,
Name => New_Occurrence_Of (Subp, Sloc (N)),
Rec => Convert_Concurrent (Rec, Etype (Rec)),
External => True);
else
Rec := Expand_Protected_Object_Reference (N, Scop);
if No (Rec) then
return;
end if;
Freeze_Called_Function;
Build_Protected_Subprogram_Call (N,
Name => Name (N),
Rec => Rec,
External => False);
end if;
-- Analyze and resolve the new call. The actuals have already been
-- resolved, but expansion of a function call will add extra actuals
-- if needed. Analysis of a procedure call already includes resolution.
Analyze (N);
if Ekind (Subp) = E_Function then
Resolve (N, Etype (Subp));
end if;
end Expand_Protected_Subprogram_Call;
-----------------------------------
-- Expand_Simple_Function_Return --
-----------------------------------
-- The "simple" comes from the syntax rule simple_return_statement. The
-- semantics are not at all simple.
procedure Expand_Simple_Function_Return (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Scope_Id : constant Entity_Id :=
Return_Applies_To (Return_Statement_Entity (N));
-- The function we are returning from
R_Type : constant Entity_Id := Etype (Scope_Id);
-- The result type of the function
Utyp : constant Entity_Id := Underlying_Type (R_Type);
Exp : Node_Id := Expression (N);
pragma Assert (Present (Exp));
Exp_Is_Function_Call : constant Boolean :=
Nkind (Exp) = N_Function_Call
or else (Nkind (Exp) = N_Explicit_Dereference
and then Is_Entity_Name (Prefix (Exp))
and then Ekind (Entity (Prefix (Exp))) = E_Constant
and then Is_Related_To_Func_Return (Entity (Prefix (Exp))));
Exp_Typ : constant Entity_Id := Etype (Exp);
-- The type of the expression (not necessarily the same as R_Type)
Subtype_Ind : Node_Id;
-- If the result type of the function is class-wide and the expression
-- has a specific type, then we use the expression's type as the type of
-- the return object. In cases where the expression is an aggregate that
-- is built in place, this avoids the need for an expensive conversion
-- of the return object to the specific type on assignments to the
-- individual components.
-- Start of processing for Expand_Simple_Function_Return
begin
if Is_Class_Wide_Type (R_Type)
and then not Is_Class_Wide_Type (Exp_Typ)
and then Nkind (Exp) /= N_Type_Conversion
then
Subtype_Ind := New_Occurrence_Of (Exp_Typ, Loc);
else
Subtype_Ind := New_Occurrence_Of (R_Type, Loc);
-- If the result type is class-wide and the expression is a view
-- conversion, the conversion plays no role in the expansion because
-- it does not modify the tag of the object. Remove the conversion
-- altogether to prevent tag overwriting.
if Is_Class_Wide_Type (R_Type)
and then not Is_Class_Wide_Type (Exp_Typ)
and then Nkind (Exp) = N_Type_Conversion
then
Exp := Expression (Exp);
end if;
end if;
-- Assert that if F says "return G(...);"
-- then F and G are both b-i-p, or neither b-i-p.
if Nkind (Exp) = N_Function_Call then
pragma Assert (Ekind (Scope_Id) = E_Function);
pragma Assert
(Is_Build_In_Place_Function (Scope_Id) =
Is_Build_In_Place_Function_Call (Exp));
null;
end if;
-- For the case of a simple return that does not come from an
-- extended return, in the case of build-in-place, we rewrite
-- "return <expression>;" to be:
-- return _anon_ : <return_subtype> := <expression>
-- The expansion produced by Expand_N_Extended_Return_Statement will
-- contain simple return statements (for example, a block containing
-- simple return of the return object), which brings us back here with
-- Comes_From_Extended_Return_Statement set. The reason for the barrier
-- checking for a simple return that does not come from an extended
-- return is to avoid this infinite recursion.
-- The reason for this design is that for Ada 2005 limited returns, we
-- need to reify the return object, so we can build it "in place", and
-- we need a block statement to hang finalization and tasking stuff.
-- ??? In order to avoid disruption, we avoid translating to extended
-- return except in the cases where we really need to (Ada 2005 for
-- inherently limited). We might prefer to do this translation in all
-- cases (except perhaps for the case of Ada 95 inherently limited),
-- in order to fully exercise the Expand_N_Extended_Return_Statement
-- code. This would also allow us to do the build-in-place optimization
-- for efficiency even in cases where it is semantically not required.
-- As before, we check the type of the return expression rather than the
-- return type of the function, because the latter may be a limited
-- class-wide interface type, which is not a limited type, even though
-- the type of the expression may be.
pragma Assert
(Comes_From_Extended_Return_Statement (N)
or else not Is_Build_In_Place_Function_Call (Exp)
or else Is_Build_In_Place_Function (Scope_Id));
if not Comes_From_Extended_Return_Statement (N)
and then Is_Build_In_Place_Function (Scope_Id)
and then not Debug_Flag_Dot_L
-- The functionality of interface thunks is simple and it is always
-- handled by means of simple return statements. This leaves their
-- expansion simple and clean.
and then not Is_Thunk (Scope_Id)
then
declare
Return_Object_Entity : constant Entity_Id :=
Make_Temporary (Loc, 'R', Exp);
Obj_Decl : constant Node_Id :=
Make_Object_Declaration (Loc,
Defining_Identifier => Return_Object_Entity,
Object_Definition => Subtype_Ind,
Expression => Exp);
Ext : constant Node_Id :=
Make_Extended_Return_Statement (Loc,
Return_Object_Declarations => New_List (Obj_Decl));
-- Do not perform this high-level optimization if the result type
-- is an interface because the "this" pointer must be displaced.
begin
Rewrite (N, Ext);
Analyze (N);
return;
end;
end if;
-- Here we have a simple return statement that is part of the expansion
-- of an extended return statement (either written by the user, or
-- generated by the above code).
-- Always normalize C/Fortran boolean result. This is not always needed,
-- but it seems a good idea to minimize the passing around of non-
-- normalized values, and in any case this handles the processing of
-- barrier functions for protected types, which turn the condition into
-- a return statement.
if Is_Boolean_Type (Exp_Typ) and then Nonzero_Is_True (Exp_Typ) then
Adjust_Condition (Exp);
Adjust_Result_Type (Exp, Exp_Typ);
end if;
-- Do validity check if enabled for returns
if Validity_Checks_On and then Validity_Check_Returns then
Ensure_Valid (Exp);
end if;
-- Check the result expression of a scalar function against the subtype
-- of the function by inserting a conversion. This conversion must
-- eventually be performed for other classes of types, but for now it's
-- only done for scalars ???
if Is_Scalar_Type (Exp_Typ) and then Exp_Typ /= R_Type then
Rewrite (Exp, Convert_To (R_Type, Exp));
-- The expression is resolved to ensure that the conversion gets
-- expanded to generate a possible constraint check.
Analyze_And_Resolve (Exp, R_Type);
end if;
-- Deal with returning variable length objects and controlled types
-- Nothing to do if we are returning by reference, or this is not a
-- type that requires special processing (indicated by the fact that
-- it requires a cleanup scope for the secondary stack case).
if Is_Build_In_Place_Function (Scope_Id)
or else Is_Limited_Interface (Exp_Typ)
then
null;
-- No copy needed for thunks returning interface type objects since
-- the object is returned by reference and the maximum functionality
-- required is just to displace the pointer.
elsif Is_Thunk (Scope_Id) and then Is_Interface (Exp_Typ) then
null;
-- If the call is within a thunk and the type is a limited view, the
-- backend will eventually see the non-limited view of the type.
elsif Is_Thunk (Scope_Id) and then Is_Incomplete_Type (Exp_Typ) then
return;
-- A return statement from an ignored Ghost function does not use the
-- secondary stack (or any other one).
elsif not Requires_Transient_Scope (R_Type)
or else Is_Ignored_Ghost_Entity (Scope_Id)
then
-- Mutable records with variable-length components are not returned
-- on the sec-stack, so we need to make sure that the back end will
-- only copy back the size of the actual value, and not the maximum
-- size. We create an actual subtype for this purpose. However we
-- need not do it if the expression is a function call since this
-- will be done in the called function and doing it here too would
-- cause a temporary with maximum size to be created.
declare
Ubt : constant Entity_Id := Underlying_Type (Base_Type (Exp_Typ));
Decl : Node_Id;
Ent : Entity_Id;
begin
if not Exp_Is_Function_Call
and then Has_Discriminants (Ubt)
and then not Is_Constrained (Ubt)
and then not Has_Unchecked_Union (Ubt)
then
Decl := Build_Actual_Subtype (Ubt, Exp);
Ent := Defining_Identifier (Decl);
Insert_Action (Exp, Decl);
Rewrite (Exp, Unchecked_Convert_To (Ent, Exp));
Analyze_And_Resolve (Exp);
end if;
end;
-- Here if secondary stack is used
else
-- Prevent the reclamation of the secondary stack by all enclosing
-- blocks and loops as well as the related function; otherwise the
-- result would be reclaimed too early.
Set_Enclosing_Sec_Stack_Return (N);
-- Optimize the case where the result is a function call that also
-- returns on the secondary stack. In this case the result is already
-- on the secondary stack and no further processing is required
-- except to set the By_Ref flag to ensure that gigi does not attempt
-- an extra unnecessary copy. (Actually not just unnecessary but
-- wrong in the case of a controlled type, where gigi does not know
-- how to do a copy.)
pragma Assert (Requires_Transient_Scope (R_Type));
if Exp_Is_Function_Call and then Requires_Transient_Scope (Exp_Typ)
then
Set_By_Ref (N);
-- Remove side effects from the expression now so that other parts
-- of the expander do not have to reanalyze this node without this
-- optimization
Rewrite (Exp, Duplicate_Subexpr_No_Checks (Exp));
-- Ada 2005 (AI-251): If the type of the returned object is
-- an interface then add an implicit type conversion to force
-- displacement of the "this" pointer.
if Is_Interface (R_Type) then
Rewrite (Exp, Convert_To (R_Type, Relocate_Node (Exp)));
end if;
Analyze_And_Resolve (Exp, R_Type);
-- For controlled types, do the allocation on the secondary stack
-- manually in order to call adjust at the right time:
-- type Anon1 is access R_Type;
-- for Anon1'Storage_pool use ss_pool;
-- Anon2 : anon1 := new R_Type'(expr);
-- return Anon2.all;
-- We do the same for classwide types that are not potentially
-- controlled (by the virtue of restriction No_Finalization) because
-- gigi is not able to properly allocate class-wide types.
elsif CW_Or_Has_Controlled_Part (Utyp) then
declare
Loc : constant Source_Ptr := Sloc (N);
Acc_Typ : constant Entity_Id := Make_Temporary (Loc, 'A');
Alloc_Node : Node_Id;
Temp : Entity_Id;
begin
Mutate_Ekind (Acc_Typ, E_Access_Type);
Set_Associated_Storage_Pool (Acc_Typ, RTE (RE_SS_Pool));
-- This is an allocator for the secondary stack, and it's fine
-- to have Comes_From_Source set False on it, as gigi knows not
-- to flag it as a violation of No_Implicit_Heap_Allocations.
Alloc_Node :=
Make_Allocator (Loc,
Expression =>
Make_Qualified_Expression (Loc,
Subtype_Mark => New_Occurrence_Of (Etype (Exp), Loc),
Expression => Relocate_Node (Exp)));
-- We do not want discriminant checks on the declaration,
-- given that it gets its value from the allocator.
Set_No_Initialization (Alloc_Node);
Temp := Make_Temporary (Loc, 'R', Alloc_Node);
Insert_List_Before_And_Analyze (N, New_List (
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Acc_Typ,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
Subtype_Indication => Subtype_Ind)),
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition => New_Occurrence_Of (Acc_Typ, Loc),
Expression => Alloc_Node)));
Rewrite (Exp,
Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (Temp, Loc)));
-- Ada 2005 (AI-251): If the type of the returned object is
-- an interface then add an implicit type conversion to force
-- displacement of the "this" pointer.
if Is_Interface (R_Type) then
Rewrite (Exp, Convert_To (R_Type, Relocate_Node (Exp)));
end if;
Analyze_And_Resolve (Exp, R_Type);
end;
-- Otherwise use the gigi mechanism to allocate result on the
-- secondary stack.
else
Check_Restriction (No_Secondary_Stack, N);
Set_Storage_Pool (N, RTE (RE_SS_Pool));
Set_Procedure_To_Call (N, RTE (RE_SS_Allocate));
end if;
end if;
-- Implement the rules of 6.5(8-10), which require a tag check in
-- the case of a limited tagged return type, and tag reassignment for
-- nonlimited tagged results. These actions are needed when the return
-- type is a specific tagged type and the result expression is a
-- conversion or a formal parameter, because in that case the tag of
-- the expression might differ from the tag of the specific result type.
-- We must also verify an underlying type exists for the return type in
-- case it is incomplete - in which case is not necessary to generate a
-- check anyway since an incomplete limited tagged return type would
-- qualify as a premature usage.
if Present (Utyp)
and then Is_Tagged_Type (Utyp)
and then not Is_Class_Wide_Type (Utyp)
and then (Nkind (Exp) in
N_Type_Conversion | N_Unchecked_Type_Conversion
or else (Nkind (Exp) = N_Explicit_Dereference
and then Nkind (Prefix (Exp)) in
N_Type_Conversion |
N_Unchecked_Type_Conversion)
or else (Is_Entity_Name (Exp)
and then Is_Formal (Entity (Exp))))
then
-- When the return type is limited, perform a check that the tag of
-- the result is the same as the tag of the return type.
if Is_Limited_Type (R_Type) then
Insert_Action (Exp,
Make_Raise_Constraint_Error (Loc,
Condition =>
Make_Op_Ne (Loc,
Left_Opnd =>
Make_Selected_Component (Loc,
Prefix => Duplicate_Subexpr (Exp),
Selector_Name => Make_Identifier (Loc, Name_uTag)),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Base_Type (Utyp), Loc),
Attribute_Name => Name_Tag)),
Reason => CE_Tag_Check_Failed));
-- If the result type is a specific nonlimited tagged type, then we
-- have to ensure that the tag of the result is that of the result
-- type. This is handled by making a copy of the expression in
-- the case where it might have a different tag, namely when the
-- expression is a conversion or a formal parameter. We create a new
-- object of the result type and initialize it from the expression,
-- which will implicitly force the tag to be set appropriately.
else
declare
ExpR : constant Node_Id := Relocate_Node (Exp);
Result_Id : constant Entity_Id :=
Make_Temporary (Loc, 'R', ExpR);
Result_Exp : constant Node_Id :=
New_Occurrence_Of (Result_Id, Loc);
Result_Obj : constant Node_Id :=
Make_Object_Declaration (Loc,
Defining_Identifier => Result_Id,
Object_Definition =>
New_Occurrence_Of (R_Type, Loc),
Constant_Present => True,
Expression => ExpR);
begin
Set_Assignment_OK (Result_Obj);
Insert_Action (Exp, Result_Obj);
Rewrite (Exp, Result_Exp);
Analyze_And_Resolve (Exp, R_Type);
end;
end if;
-- Ada 2005 (AI95-344): If the result type is class-wide, then insert
-- a check that the level of the return expression's underlying type
-- is not deeper than the level of the master enclosing the function.
-- AI12-043: The check is made immediately after the return object is
-- created. This means that we do not apply it to the simple return
-- generated by the expansion of an extended return statement.
-- No runtime check needed in interface thunks since it is performed
-- by the target primitive associated with the thunk.
elsif Is_Class_Wide_Type (R_Type)
and then not Comes_From_Extended_Return_Statement (N)
and then not Is_Thunk (Scope_Id)
then
Apply_CW_Accessibility_Check (Exp, Scope_Id);
-- Ada 2012 (AI05-0073): If the result subtype of the function is
-- defined by an access_definition designating a specific tagged
-- type T, a check is made that the result value is null or the tag
-- of the object designated by the result value identifies T.
-- The return expression is referenced twice in the code below, so it
-- must be made free of side effects. Given that different compilers
-- may evaluate these parameters in different order, both occurrences
-- perform a copy.
elsif Ekind (R_Type) = E_Anonymous_Access_Type
and then Is_Tagged_Type (Designated_Type (R_Type))
and then not Is_Class_Wide_Type (Designated_Type (R_Type))
and then Nkind (Original_Node (Exp)) /= N_Null
and then not Tag_Checks_Suppressed (Designated_Type (R_Type))
then
-- Generate:
-- [Constraint_Error
-- when Exp /= null
-- and then Exp.all not in Designated_Type]
Insert_Action (N,
Make_Raise_Constraint_Error (Loc,
Condition =>
Make_And_Then (Loc,
Left_Opnd =>
Make_Op_Ne (Loc,
Left_Opnd => Duplicate_Subexpr (Exp),
Right_Opnd => Make_Null (Loc)),
Right_Opnd =>
Make_Not_In (Loc,
Left_Opnd =>
Make_Explicit_Dereference (Loc,
Prefix => Duplicate_Subexpr (Exp)),
Right_Opnd =>
New_Occurrence_Of (Designated_Type (R_Type), Loc))),
Reason => CE_Tag_Check_Failed),
Suppress => All_Checks);
end if;
-- If the result is of an unconstrained array subtype with fixed lower
-- bound, then sliding to that bound may be needed.
if Is_Fixed_Lower_Bound_Array_Subtype (R_Type) then
Expand_Sliding_Conversion (Exp, R_Type);
end if;
-- If we are returning a nonscalar object that is possibly unaligned,
-- then copy the value into a temporary first. This copy may need to
-- expand to a loop of component operations.
if Is_Possibly_Unaligned_Slice (Exp)
or else (Is_Possibly_Unaligned_Object (Exp)
and then not Represented_As_Scalar (Etype (Exp)))
then
declare
ExpR : constant Node_Id := Relocate_Node (Exp);
Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', ExpR);
begin
Insert_Action (Exp,
Make_Object_Declaration (Loc,
Defining_Identifier => Tnn,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (R_Type, Loc),
Expression => ExpR),
Suppress => All_Checks);
Rewrite (Exp, New_Occurrence_Of (Tnn, Loc));
end;
end if;
-- Call the _Postconditions procedure if the related function has
-- contract assertions that need to be verified on exit.
if Ekind (Scope_Id) = E_Function
and then Present (Postconditions_Proc (Scope_Id))
then
-- In the case of discriminated objects, we have created a
-- constrained subtype above, and used the underlying type. This
-- transformation is post-analysis and harmless, except that now the
-- call to the post-condition will be analyzed and the type kinds
-- have to match.
if Nkind (Exp) = N_Unchecked_Type_Conversion
and then Is_Private_Type (R_Type) /= Is_Private_Type (Etype (Exp))
then
Rewrite (Exp, Expression (Relocate_Node (Exp)));
end if;
-- We are going to reference the returned value twice in this case,
-- once in the call to _Postconditions, and once in the actual return
-- statement, but we can't have side effects happening twice.
Force_Evaluation (Exp, Mode => Strict);
-- Save the return value or a pointer to the return value since we
-- may need to call postconditions after finalization when cleanup
-- actions are present.
-- Generate:
--
-- Result_Object_For_Postcond := [Exp]'Unrestricted_Access;
Insert_Action (Exp,
Make_Assignment_Statement (Loc,
Name =>
New_Occurrence_Of
(Get_Result_Object_For_Postcond (Scope_Id), Loc),
Expression =>
(if Is_Elementary_Type (Etype (R_Type)) then
New_Copy_Tree (Exp)
else
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Unrestricted_Access,
Prefix => New_Copy_Tree (Exp)))));
-- Mark the successful return to signal that postconditions need to
-- be evaluated when finalization occurs.
-- Generate:
--
-- Return_Success_For_Postcond := True;
-- if Postcond_Enabled then
-- _Postconditions ([exp]);
-- end if;
Insert_Action (Exp,
Make_Assignment_Statement (Loc,
Name =>
New_Occurrence_Of
(Get_Return_Success_For_Postcond (Scope_Id), Loc),
Expression => New_Occurrence_Of (Standard_True, Loc)));
-- Wrap the call to _postconditions within a test of the
-- Postcond_Enabled flag to delay postcondition evaluation until
-- after finalization when required.
Insert_Action (Exp,
Make_If_Statement (Loc,
Condition =>
New_Occurrence_Of (Get_Postcond_Enabled (Scope_Id), Loc),
Then_Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of
(Postconditions_Proc (Scope_Id), Loc),
Parameter_Associations => New_List (New_Copy_Tree (Exp))))));
end if;
-- Ada 2005 (AI-251): If this return statement corresponds with an
-- simple return statement associated with an extended return statement
-- and the type of the returned object is an interface then generate an
-- implicit conversion to force displacement of the "this" pointer.
if Ada_Version >= Ada_2005
and then Comes_From_Extended_Return_Statement (N)
and then Nkind (Expression (N)) = N_Identifier
and then Is_Interface (Utyp)
and then Utyp /= Underlying_Type (Exp_Typ)
then
Rewrite (Exp, Convert_To (Utyp, Relocate_Node (Exp)));
Analyze_And_Resolve (Exp);
end if;
-- Ada 2022 (AI12-0279)
if Has_Yield_Aspect (Scope_Id)
and then RTE_Available (RE_Yield)
then
Insert_Action (N,
Make_Procedure_Call_Statement (Loc,
New_Occurrence_Of (RTE (RE_Yield), Loc)));
end if;
end Expand_Simple_Function_Return;
-----------------------
-- Freeze_Subprogram --
-----------------------
procedure Freeze_Subprogram (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
procedure Register_Predefined_DT_Entry (Prim : Entity_Id);
-- (Ada 2005): Register a predefined primitive in all the secondary
-- dispatch tables of its primitive type.
----------------------------------
-- Register_Predefined_DT_Entry --
----------------------------------
procedure Register_Predefined_DT_Entry (Prim : Entity_Id) is
Iface_DT_Ptr : Elmt_Id;
Tagged_Typ : Entity_Id;
Thunk_Id : Entity_Id;
Thunk_Code : Node_Id;
begin
Tagged_Typ := Find_Dispatching_Type (Prim);
if No (Access_Disp_Table (Tagged_Typ))
or else not Has_Interfaces (Tagged_Typ)
or else not RTE_Available (RE_Interface_Tag)
or else Restriction_Active (No_Dispatching_Calls)
then
return;
end if;
-- Skip the first two access-to-dispatch-table pointers since they
-- leads to the primary dispatch table (predefined DT and user
-- defined DT). We are only concerned with the secondary dispatch
-- table pointers. Note that the access-to- dispatch-table pointer
-- corresponds to the first implemented interface retrieved below.
Iface_DT_Ptr :=
Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Tagged_Typ))));
while Present (Iface_DT_Ptr)
and then Ekind (Node (Iface_DT_Ptr)) = E_Constant
loop
pragma Assert (Has_Thunks (Node (Iface_DT_Ptr)));
Expand_Interface_Thunk (Prim, Thunk_Id, Thunk_Code,
Iface => Related_Type (Node (Iface_DT_Ptr)));
if Present (Thunk_Code) then
Insert_Actions_After (N, New_List (
Thunk_Code,
Build_Set_Predefined_Prim_Op_Address (Loc,
Tag_Node =>
New_Occurrence_Of (Node (Next_Elmt (Iface_DT_Ptr)), Loc),
Position => DT_Position (Prim),
Address_Node =>
Unchecked_Convert_To (RTE (RE_Prim_Ptr),
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Thunk_Id, Loc),
Attribute_Name => Name_Unrestricted_Access))),
Build_Set_Predefined_Prim_Op_Address (Loc,
Tag_Node =>
New_Occurrence_Of
(Node (Next_Elmt (Next_Elmt (Next_Elmt (Iface_DT_Ptr)))),
Loc),
Position => DT_Position (Prim),
Address_Node =>
Unchecked_Convert_To (RTE (RE_Prim_Ptr),
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Prim, Loc),
Attribute_Name => Name_Unrestricted_Access)))));
end if;
-- Skip the tag of the predefined primitives dispatch table
Next_Elmt (Iface_DT_Ptr);
pragma Assert (Has_Thunks (Node (Iface_DT_Ptr)));
-- Skip tag of the no-thunks dispatch table
Next_Elmt (Iface_DT_Ptr);
pragma Assert (not Has_Thunks (Node (Iface_DT_Ptr)));
-- Skip tag of predefined primitives no-thunks dispatch table
Next_Elmt (Iface_DT_Ptr);
pragma Assert (not Has_Thunks (Node (Iface_DT_Ptr)));
Next_Elmt (Iface_DT_Ptr);
end loop;
end Register_Predefined_DT_Entry;
-- Local variables
Subp : constant Entity_Id := Entity (N);
-- Start of processing for Freeze_Subprogram
begin
-- We suppress the initialization of the dispatch table entry when
-- not Tagged_Type_Expansion because the dispatching mechanism is
-- handled internally by the target.
if Is_Dispatching_Operation (Subp)
and then not Is_Abstract_Subprogram (Subp)
and then Present (DTC_Entity (Subp))
and then Present (Scope (DTC_Entity (Subp)))
and then Tagged_Type_Expansion
and then not Restriction_Active (No_Dispatching_Calls)
and then RTE_Available (RE_Tag)
then
declare
Typ : constant Entity_Id := Scope (DTC_Entity (Subp));
begin
-- Handle private overridden primitives
if not Is_CPP_Class (Typ) then
Check_Overriding_Operation (Subp);
end if;
-- We assume that imported CPP primitives correspond with objects
-- whose constructor is in the CPP side; therefore we don't need
-- to generate code to register them in the dispatch table.
if Is_CPP_Class (Typ) then
null;
-- Handle CPP primitives found in derivations of CPP_Class types.
-- These primitives must have been inherited from some parent, and
-- there is no need to register them in the dispatch table because
-- Build_Inherit_Prims takes care of initializing these slots.
elsif Is_Imported (Subp)
and then Convention (Subp) in Convention_C_Family
then
null;
-- Generate code to register the primitive in non statically
-- allocated dispatch tables
elsif not Building_Static_DT (Scope (DTC_Entity (Subp))) then
-- When a primitive is frozen, enter its name in its dispatch
-- table slot.
if not Is_Interface (Typ)
or else Present (Interface_Alias (Subp))
then
if Is_Predefined_Dispatching_Operation (Subp) then
Register_Predefined_DT_Entry (Subp);
end if;
Insert_Actions_After (N,
Register_Primitive (Loc, Prim => Subp));
end if;
end if;
end;
end if;
-- Mark functions that return by reference. Note that it cannot be part
-- of the normal semantic analysis of the spec since the underlying
-- returned type may not be known yet (for private types).
Compute_Returns_By_Ref (Subp);
end Freeze_Subprogram;
--------------------------
-- Has_BIP_Extra_Formal --
--------------------------
function Has_BIP_Extra_Formal
(E : Entity_Id;
Kind : BIP_Formal_Kind) return Boolean
is
Extra_Formal : Entity_Id := Extra_Formals (E);
begin
-- We can only rely on the availability of the extra formals in frozen
-- entities or in subprogram types of dispatching calls (since their
-- extra formals are added when the target subprogram is frozen; see
-- Expand_Dispatching_Call).
pragma Assert (Is_Frozen (E)
or else (Ekind (E) = E_Subprogram_Type
and then Is_Dispatch_Table_Entity (E))
or else (Is_Dispatching_Operation (E)
and then Is_Frozen (Find_Dispatching_Type (E))));
while Present (Extra_Formal) loop
if Is_Build_In_Place_Entity (Extra_Formal)
and then BIP_Suffix_Kind (Extra_Formal) = Kind
then
return True;
end if;
Next_Formal_With_Extras (Extra_Formal);
end loop;
return False;
end Has_BIP_Extra_Formal;
------------------------------
-- Insert_Post_Call_Actions --
------------------------------
procedure Insert_Post_Call_Actions (N : Node_Id; Post_Call : List_Id) is
Context : constant Node_Id := Parent (N);
begin
if Is_Empty_List (Post_Call) then
return;
end if;
-- Cases where the call is not a member of a statement list. This also
-- includes the cases where the call is an actual in another function
-- call, or is an index, or is an operand of an if-expression, i.e. is
-- in an expression context.
if not Is_List_Member (N)
or else Nkind (Context) in N_Function_Call
| N_If_Expression
| N_Indexed_Component
then
-- In Ada 2012 the call may be a function call in an expression
-- (since OUT and IN OUT parameters are now allowed for such calls).
-- The write-back of (in)-out parameters is handled by the back-end,
-- but the constraint checks generated when subtypes of formal and
-- actual don't match must be inserted in the form of assignments.
-- Also do this in the case of explicit dereferences, which can occur
-- due to rewritings of function calls with controlled results.
if Nkind (N) = N_Function_Call
or else Nkind (Original_Node (N)) = N_Function_Call
or else Nkind (N) = N_Explicit_Dereference
then
pragma Assert (Ada_Version >= Ada_2012);
-- Functions with '[in] out' parameters are only allowed in Ada
-- 2012.
-- We used to handle this by climbing up parents to a
-- non-statement/declaration and then simply making a call to
-- Insert_Actions_After (P, Post_Call), but that doesn't work
-- for Ada 2012. If we are in the middle of an expression, e.g.
-- the condition of an IF, this call would insert after the IF
-- statement, which is much too late to be doing the write back.
-- For example:
-- if Clobber (X) then
-- Put_Line (X'Img);
-- else
-- goto Junk
-- end if;
-- Now assume Clobber changes X, if we put the write back after
-- the IF, the Put_Line gets the wrong value and the goto causes
-- the write back to be skipped completely.
-- To deal with this, we replace the call by
--
-- do
-- Tnnn : constant function-result-type := function-call;
-- Post_Call actions
-- in
-- Tnnn;
-- end;
--
-- However, that doesn't work if function-result-type requires
-- finalization (because function-call's result never gets
-- finalized). So in that case, we instead replace the call by
--
-- do
-- type Ref is access all function-result-type;
-- Ptr : constant Ref := function-call'Reference;
-- Tnnn : constant function-result-type := Ptr.all;
-- Finalize (Ptr.all);
-- Post_Call actions
-- in
-- Tnnn;
-- end;
--
declare
Loc : constant Source_Ptr := Sloc (N);
Tnnn : constant Entity_Id := Make_Temporary (Loc, 'T');
FRTyp : constant Entity_Id := Etype (N);
Name : constant Node_Id := Relocate_Node (N);
begin
if Needs_Finalization (FRTyp) then
declare
Ptr_Typ : constant Entity_Id := Make_Temporary (Loc, 'A');
Ptr_Typ_Decl : constant Node_Id :=
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 (FRTyp, Loc)));
Ptr_Obj : constant Entity_Id :=
Make_Temporary (Loc, 'P');
Ptr_Obj_Decl : constant Node_Id :=
Make_Object_Declaration (Loc,
Defining_Identifier => Ptr_Obj,
Object_Definition =>
New_Occurrence_Of (Ptr_Typ, Loc),
Constant_Present => True,
Expression =>
Make_Attribute_Reference (Loc,
Prefix => Name,
Attribute_Name => Name_Unrestricted_Access));
function Ptr_Dereference return Node_Id is
(Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (Ptr_Obj, Loc)));
Tnn_Decl : constant Node_Id :=
Make_Object_Declaration (Loc,
Defining_Identifier => Tnnn,
Object_Definition => New_Occurrence_Of (FRTyp, Loc),
Constant_Present => True,
Expression => Ptr_Dereference);
Finalize_Call : constant Node_Id :=
Make_Final_Call
(Obj_Ref => Ptr_Dereference, Typ => FRTyp);
begin
-- Prepend in reverse order
Prepend_To (Post_Call, Finalize_Call);
Prepend_To (Post_Call, Tnn_Decl);
Prepend_To (Post_Call, Ptr_Obj_Decl);
Prepend_To (Post_Call, Ptr_Typ_Decl);
end;
else
Prepend_To (Post_Call,
Make_Object_Declaration (Loc,
Defining_Identifier => Tnnn,
Object_Definition => New_Occurrence_Of (FRTyp, Loc),
Constant_Present => True,
Expression => Name));
end if;
Rewrite (N,
Make_Expression_With_Actions (Loc,
Actions => Post_Call,
Expression => New_Occurrence_Of (Tnnn, Loc)));
-- We don't want to just blindly call Analyze_And_Resolve
-- because that would cause unwanted recursion on the call.
-- So for a moment set the call as analyzed to prevent that
-- recursion, and get the rest analyzed properly, then reset
-- the analyzed flag, so our caller can continue.
Set_Analyzed (Name, True);
Analyze_And_Resolve (N, FRTyp);
Set_Analyzed (Name, False);
end;
-- If not the special Ada 2012 case of a function call, then we must
-- have the triggering statement of a triggering alternative or an
-- entry call alternative, and we can add the post call stuff to the
-- corresponding statement list.
else
pragma Assert (Nkind (Context) in N_Entry_Call_Alternative
| N_Triggering_Alternative);
if Is_Non_Empty_List (Statements (Context)) then
Insert_List_Before_And_Analyze
(First (Statements (Context)), Post_Call);
else
Set_Statements (Context, Post_Call);
end if;
end if;
-- A procedure call is always part of a declarative or statement list,
-- however a function call may appear nested within a construct. Most
-- cases of function call nesting are handled in the special case above.
-- The only exception is when the function call acts as an actual in a
-- procedure call. In this case the function call is in a list, but the
-- post-call actions must be inserted after the procedure call.
-- What if the function call is an aggregate component ???
elsif Nkind (Context) = N_Procedure_Call_Statement then
Insert_Actions_After (Context, Post_Call);
-- Otherwise, normal case where N is in a statement sequence, just put
-- the post-call stuff after the call statement.
else
Insert_Actions_After (N, Post_Call);
end if;
end Insert_Post_Call_Actions;
---------------------------------------
-- Install_Class_Preconditions_Check --
---------------------------------------
procedure Install_Class_Preconditions_Check (Call_Node : Node_Id) is
Loc : constant Source_Ptr := Sloc (Call_Node);
function Build_Dynamic_Check_Helper_Call return Node_Id;
-- Build call to the helper runtime function of the nearest ancestor
-- of the target subprogram that dynamically evaluates the merged
-- or-else preconditions.
function Build_Error_Message (Subp_Id : Entity_Id) return Node_Id;
-- Build message associated with the class-wide precondition of Subp_Id
-- indicating the call that caused it.
function Build_Static_Check_Helper_Call return Node_Id;
-- Build call to the helper runtime function of the nearest ancestor
-- of the target subprogram that dynamically evaluates the merged
-- or-else preconditions.
function Class_Preconditions_Subprogram
(Spec_Id : Entity_Id;
Dynamic : Boolean) return Node_Id;
-- Return the nearest ancestor of Spec_Id defining a helper function
-- that evaluates a combined or-else expression containing all the
-- inherited class-wide preconditions; Dynamic enables searching for
-- the helper that dynamically evaluates preconditions using dispatching
-- calls; if False it searches for the helper that statically evaluates
-- preconditions; return Empty when not available (which means that no
-- preconditions check is required).
-------------------------------------
-- Build_Dynamic_Check_Helper_Call --
-------------------------------------
function Build_Dynamic_Check_Helper_Call return Node_Id is
Spec_Id : constant Entity_Id := Entity (Name (Call_Node));
CW_Subp : constant Entity_Id :=
Class_Preconditions_Subprogram (Spec_Id,
Dynamic => True);
Helper_Id : constant Entity_Id :=
Dynamic_Call_Helper (CW_Subp);
Actuals : constant List_Id := New_List;
A : Node_Id := First_Actual (Call_Node);
F : Entity_Id := First_Formal (Helper_Id);
begin
while Present (A) loop
-- Ensure that the evaluation of the actuals will not produce
-- side effects.
Remove_Side_Effects (A);
Append_To (Actuals, New_Copy_Tree (A));
Next_Formal (F);
Next_Actual (A);
end loop;
return
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Helper_Id, Loc),
Parameter_Associations => Actuals);
end Build_Dynamic_Check_Helper_Call;
-------------------------
-- Build_Error_Message --
-------------------------
function Build_Error_Message (Subp_Id : Entity_Id) return Node_Id is
procedure Append_Message
(Id : Entity_Id;
Is_First : in out Boolean);
-- Build the fragment of the message associated with subprogram Id;
-- Is_First facilitates identifying continuation messages.
--------------------
-- Append_Message --
--------------------
procedure Append_Message
(Id : Entity_Id;
Is_First : in out Boolean)
is
Prag : constant Node_Id := Get_Class_Wide_Pragma (Id,
Pragma_Precondition);
Msg : Node_Id;
Str_Id : String_Id;
begin
if No (Prag) or else Is_Ignored (Prag) then
return;
end if;
Msg := Expression (Last (Pragma_Argument_Associations (Prag)));
Str_Id := Strval (Msg);
if Is_First then
Is_First := False;
Append (Global_Name_Buffer, Strval (Msg));
if Id /= Subp_Id
and then Name_Buffer (1 .. 19) = "failed precondition"
then
Insert_Str_In_Name_Buffer ("inherited ", 8);
end if;
else
declare
Str : constant String := To_String (Str_Id);
From_Idx : Integer;
begin
Append (Global_Name_Buffer, ASCII.LF);
Append (Global_Name_Buffer, " or ");
From_Idx := Name_Len;
Append (Global_Name_Buffer, Str_Id);
if Str (1 .. 19) = "failed precondition" then
Insert_Str_In_Name_Buffer ("inherited ", From_Idx + 8);
end if;
end;
end if;
end Append_Message;
-- Local variables
Str_Loc : constant String := Build_Location_String (Loc);
Subps : constant Subprogram_List :=
Inherited_Subprograms (Subp_Id);
Is_First : Boolean := True;
-- Start of processing for Build_Error_Message
begin
Name_Len := 0;
Append_Message (Subp_Id, Is_First);
for Index in Subps'Range loop
Append_Message (Subps (Index), Is_First);
end loop;
if Present (Controlling_Argument (Call_Node)) then
Append (Global_Name_Buffer, " in dispatching call at ");
else
Append (Global_Name_Buffer, " in call at ");
end if;
Append (Global_Name_Buffer, Str_Loc);
return Make_String_Literal (Loc, Name_Buffer (1 .. Name_Len));
end Build_Error_Message;
------------------------------------
-- Build_Static_Check_Helper_Call --
------------------------------------
function Build_Static_Check_Helper_Call return Node_Id is
Actuals : constant List_Id := New_List;
A : Node_Id;
Helper_Id : Entity_Id;
F : Entity_Id;
CW_Subp : Entity_Id;
Spec_Id : constant Entity_Id := Entity (Name (Call_Node));
begin
-- The target is the wrapper built to support inheriting body but
-- overriding pre/postconditions (AI12-0195).
if Is_Dispatch_Table_Wrapper (Spec_Id) then
CW_Subp := Spec_Id;
-- Common case
else
CW_Subp := Class_Preconditions_Subprogram (Spec_Id,
Dynamic => False);
end if;
Helper_Id := Static_Call_Helper (CW_Subp);
F := First_Formal (Helper_Id);
A := First_Actual (Call_Node);
while Present (A) loop
-- Ensure that the evaluation of the actuals will not produce
-- side effects.
Remove_Side_Effects (A);
if Is_Controlling_Actual (A)
and then Etype (F) /= Etype (A)
then
Append_To (Actuals,
Make_Unchecked_Type_Conversion (Loc,
New_Occurrence_Of (Etype (F), Loc),
New_Copy_Tree (A)));
else
Append_To (Actuals, New_Copy_Tree (A));
end if;
Next_Formal (F);
Next_Actual (A);
end loop;
return
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Helper_Id, Loc),
Parameter_Associations => Actuals);
end Build_Static_Check_Helper_Call;
------------------------------------
-- Class_Preconditions_Subprogram --
------------------------------------
function Class_Preconditions_Subprogram
(Spec_Id : Entity_Id;
Dynamic : Boolean) return Node_Id
is
Subp_Id : constant Entity_Id := Ultimate_Alias (Spec_Id);
begin
-- Prevent cascaded errors
if not Is_Dispatching_Operation (Subp_Id) then
return Empty;
-- No need to search if this subprogram has the helper we are
-- searching
elsif Dynamic then
if Present (Dynamic_Call_Helper (Subp_Id)) then
return Subp_Id;
end if;
else
if Present (Static_Call_Helper (Subp_Id)) then
return Subp_Id;
end if;
end if;
-- Process inherited subprograms looking for class-wide
-- preconditions.
declare
Subps : constant Subprogram_List :=
Inherited_Subprograms (Subp_Id);
Subp_Id : Entity_Id;
begin
for Index in Subps'Range loop
Subp_Id := Subps (Index);
if Present (Alias (Subp_Id)) then
Subp_Id := Ultimate_Alias (Subp_Id);
end if;
-- Wrappers of class-wide pre/postconditions reference the
-- parent primitive that has the inherited contract.
if Is_Wrapper (Subp_Id)
and then Present (LSP_Subprogram (Subp_Id))
then
Subp_Id := LSP_Subprogram (Subp_Id);
end if;
if Dynamic then
if Present (Dynamic_Call_Helper (Subp_Id)) then
return Subp_Id;
end if;
else
if Present (Static_Call_Helper (Subp_Id)) then
return Subp_Id;
end if;
end if;
end loop;
end;
return Empty;
end Class_Preconditions_Subprogram;
-- Local variables
Dynamic_Check : constant Boolean :=
Present (Controlling_Argument (Call_Node));
Class_Subp : Entity_Id;
Cond : Node_Id;
Subp : Entity_Id;
-- Start of processing for Install_Class_Preconditions_Check
begin
-- Do not expand the check if we are compiling under restriction
-- No_Dispatching_Calls; the semantic analyzer has previously
-- notified the violation of this restriction.
if Dynamic_Check
and then Restriction_Active (No_Dispatching_Calls)
then
return;
-- Class-wide precondition check not needed in interface thunks since
-- they are installed in the dispatching call that caused invoking the
-- thunk.
elsif Is_Thunk (Current_Scope) then
return;
end if;
Subp := Entity (Name (Call_Node));
-- No check needed for this subprogram call if no class-wide
-- preconditions apply (or if the unique available preconditions
-- are ignored preconditions).
Class_Subp := Class_Preconditions_Subprogram (Subp, Dynamic_Check);
if No (Class_Subp)
or else No (Class_Preconditions (Class_Subp))
then
return;
end if;
-- Build and install the check
if Dynamic_Check then
Cond := Build_Dynamic_Check_Helper_Call;
else
Cond := Build_Static_Check_Helper_Call;
end if;
if Exception_Locations_Suppressed then
Insert_Action (Call_Node,
Make_If_Statement (Loc,
Condition => Make_Op_Not (Loc, Cond),
Then_Statements => New_List (
Make_Raise_Statement (Loc,
Name =>
New_Occurrence_Of
(RTE (RE_Assert_Failure), Loc)))));
-- Failed check with message indicating the failed precondition and the
-- call that caused it.
else
Insert_Action (Call_Node,
Make_If_Statement (Loc,
Condition => Make_Op_Not (Loc, Cond),
Then_Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of
(RTE (RE_Raise_Assert_Failure), Loc),
Parameter_Associations =>
New_List (Build_Error_Message (Subp))))));
end if;
end Install_Class_Preconditions_Check;
-----------------------------------
-- Is_Build_In_Place_Result_Type --
-----------------------------------
function Is_Build_In_Place_Result_Type (Typ : Entity_Id) return Boolean is
begin
if not Expander_Active then
return False;
end if;
-- In Ada 2005 all functions with an inherently limited return type
-- must be handled using a build-in-place profile, including the case
-- of a function with a limited interface result, where the function
-- may return objects of nonlimited descendants.
if Is_Limited_View (Typ) then
return Ada_Version >= Ada_2005 and then not Debug_Flag_Dot_L;
else
if Debug_Flag_Dot_9 then
return False;
end if;
if Has_Interfaces (Typ) then
return False;
end if;
declare
T : Entity_Id := Typ;
begin
-- For T'Class, return True if it's True for T. This is necessary
-- because a class-wide function might say "return F (...)", where
-- F returns the corresponding specific type. We need a loop in
-- case T is a subtype of a class-wide type.
while Is_Class_Wide_Type (T) loop
T := Etype (T);
end loop;
-- If this is a generic formal type in an instance, return True if
-- it's True for the generic actual type.
if Nkind (Parent (T)) = N_Subtype_Declaration
and then Present (Generic_Parent_Type (Parent (T)))
then
T := Entity (Subtype_Indication (Parent (T)));
if Present (Full_View (T)) then
T := Full_View (T);
end if;
end if;
if Present (Underlying_Type (T)) then
T := Underlying_Type (T);
end if;
declare
Result : Boolean;
-- So we can stop here in the debugger
begin
-- ???For now, enable build-in-place for a very narrow set of
-- controlled types. Change "if True" to "if False" to
-- experiment with more controlled types. Eventually, we might
-- like to enable build-in-place for all tagged types, all
-- types that need finalization, and all caller-unknown-size
-- types.
if True then
Result := Is_Controlled (T)
and then not Is_Generic_Actual_Type (T)
and then Present (Enclosing_Subprogram (T))
and then not Is_Compilation_Unit (Enclosing_Subprogram (T))
and then Ekind (Enclosing_Subprogram (T)) = E_Procedure;
else
Result := Is_Controlled (T);
end if;
return Result;
end;
end;
end if;
end Is_Build_In_Place_Result_Type;
------------------------------
-- Is_Build_In_Place_Entity --
------------------------------
function Is_Build_In_Place_Entity (E : Entity_Id) return Boolean is
Nam : constant String := Get_Name_String (Chars (E));
function Has_Suffix (Suffix : String) return Boolean;
-- Return True if Nam has suffix Suffix
function Has_Suffix (Suffix : String) return Boolean is
Len : constant Natural := Suffix'Length;
begin
return Nam'Length > Len
and then Nam (Nam'Last - Len + 1 .. Nam'Last) = Suffix;
end Has_Suffix;
-- Start of processing for Is_Build_In_Place_Entity
begin
return Has_Suffix (BIP_Alloc_Suffix)
or else Has_Suffix (BIP_Storage_Pool_Suffix)
or else Has_Suffix (BIP_Finalization_Master_Suffix)
or else Has_Suffix (BIP_Task_Master_Suffix)
or else Has_Suffix (BIP_Activation_Chain_Suffix)
or else Has_Suffix (BIP_Object_Access_Suffix);
end Is_Build_In_Place_Entity;
--------------------------------
-- Is_Build_In_Place_Function --
--------------------------------
function Is_Build_In_Place_Function (E : Entity_Id) return Boolean is
begin
-- This function is called from Expand_Subtype_From_Expr during
-- semantic analysis, even when expansion is off. In those cases
-- the build_in_place expansion will not take place.
if not Expander_Active then
return False;
end if;
if Ekind (E) in E_Function | E_Generic_Function
or else (Ekind (E) = E_Subprogram_Type
and then Etype (E) /= Standard_Void_Type)
then
-- If the function is imported from a foreign language, we don't do
-- build-in-place. Note that Import (Ada) functions can do
-- build-in-place. Note that it is OK for a build-in-place function
-- to return a type with a foreign convention; the build-in-place
-- machinery will ensure there is no copying.
return Is_Build_In_Place_Result_Type (Etype (E))
and then not (Has_Foreign_Convention (E) and then Is_Imported (E))
and then not Debug_Flag_Dot_L;
else
return False;
end if;
end Is_Build_In_Place_Function;
-------------------------------------
-- Is_Build_In_Place_Function_Call --
-------------------------------------
function Is_Build_In_Place_Function_Call (N : Node_Id) return Boolean is
Exp_Node : constant Node_Id := Unqual_Conv (N);
Function_Id : Entity_Id;
begin
-- Return False if the expander is currently inactive, since awareness
-- of build-in-place treatment is only relevant during expansion. Note
-- that Is_Build_In_Place_Function, which is called as part of this
-- function, is also conditioned this way, but we need to check here as
-- well to avoid blowing up on processing protected calls when expansion
-- is disabled (such as with -gnatc) since those would trip over the
-- raise of Program_Error below.
-- In SPARK mode, build-in-place calls are not expanded, so that we
-- may end up with a call that is neither resolved to an entity, nor
-- an indirect call.
if not Expander_Active or else Nkind (Exp_Node) /= N_Function_Call then
return False;
end if;
if Is_Entity_Name (Name (Exp_Node)) then
Function_Id := Entity (Name (Exp_Node));
-- In the case of an explicitly dereferenced call, use the subprogram
-- type generated for the dereference.
elsif Nkind (Name (Exp_Node)) = N_Explicit_Dereference then
Function_Id := Etype (Name (Exp_Node));
-- This may be a call to a protected function.
elsif Nkind (Name (Exp_Node)) = N_Selected_Component then
-- The selector in question might not have been analyzed due to a
-- previous error, so analyze it here to output the appropriate
-- error message instead of crashing when attempting to fetch its
-- entity.
if not Analyzed (Selector_Name (Name (Exp_Node))) then
Analyze (Selector_Name (Name (Exp_Node)));
end if;
Function_Id := Etype (Entity (Selector_Name (Name (Exp_Node))));
else
raise Program_Error;
end if;
declare
Result : constant Boolean := Is_Build_In_Place_Function (Function_Id);
-- So we can stop here in the debugger
begin
return Result;
end;
end Is_Build_In_Place_Function_Call;
-----------------------
-- Is_Null_Procedure --
-----------------------
function Is_Null_Procedure (Subp : Entity_Id) return Boolean is
Decl : constant Node_Id := Unit_Declaration_Node (Subp);
begin
if Ekind (Subp) /= E_Procedure then
return False;
-- Check if this is a declared null procedure
elsif Nkind (Decl) = N_Subprogram_Declaration then
if not Null_Present (Specification (Decl)) then
return False;
elsif No (Body_To_Inline (Decl)) then
return False;
-- Check if the body contains only a null statement, followed by
-- the return statement added during expansion.
else
declare
Orig_Bod : constant Node_Id := Body_To_Inline (Decl);
Stat : Node_Id;
Stat2 : Node_Id;
begin
if Nkind (Orig_Bod) /= N_Subprogram_Body then
return False;
else
-- We must skip SCIL nodes because they are currently
-- implemented as special N_Null_Statement nodes.
Stat :=
First_Non_SCIL_Node
(Statements (Handled_Statement_Sequence (Orig_Bod)));
Stat2 := Next_Non_SCIL_Node (Stat);
return
Is_Empty_List (Declarations (Orig_Bod))
and then Nkind (Stat) = N_Null_Statement
and then
(No (Stat2)
or else
(Nkind (Stat2) = N_Simple_Return_Statement
and then No (Next (Stat2))));
end if;
end;
end if;
else
return False;
end if;
end Is_Null_Procedure;
-------------------------------------------
-- Make_Build_In_Place_Call_In_Allocator --
-------------------------------------------
procedure Make_Build_In_Place_Call_In_Allocator
(Allocator : Node_Id;
Function_Call : Node_Id)
is
Acc_Type : constant Entity_Id := Etype (Allocator);
Loc : constant Source_Ptr := Sloc (Function_Call);
Func_Call : Node_Id := Function_Call;
Ref_Func_Call : Node_Id;
Function_Id : Entity_Id;
Result_Subt : Entity_Id;
New_Allocator : Node_Id;
Return_Obj_Access : Entity_Id; -- temp for function result
Temp_Init : Node_Id; -- initial value of Return_Obj_Access
Alloc_Form : BIP_Allocation_Form;
Pool : Node_Id; -- nonnull if Alloc_Form = User_Storage_Pool
Return_Obj_Actual : Node_Id; -- the temp.all, in caller-allocates case
Chain : Entity_Id; -- activation chain, in case of tasks
begin
-- Step past qualification or unchecked conversion (the latter can occur
-- in cases of calls to 'Input).
if Nkind (Func_Call) in N_Qualified_Expression
| N_Type_Conversion
| N_Unchecked_Type_Conversion
then
Func_Call := Expression (Func_Call);
end if;
-- Mark the call as processed as a build-in-place call
pragma Assert (not Is_Expanded_Build_In_Place_Call (Func_Call));
Set_Is_Expanded_Build_In_Place_Call (Func_Call);
if Is_Entity_Name (Name (Func_Call)) then
Function_Id := Entity (Name (Func_Call));
elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
Function_Id := Etype (Name (Func_Call));
else
raise Program_Error;
end if;
Warn_BIP (Func_Call);
Result_Subt := Available_View (Etype (Function_Id));
-- Create a temp for the function result. In the caller-allocates case,
-- this will be initialized to the result of a new uninitialized
-- allocator. Note: we do not use Allocator as the Related_Node of
-- Return_Obj_Access in call to Make_Temporary below as this would
-- create a sort of infinite "recursion".
Return_Obj_Access := Make_Temporary (Loc, 'R');
Set_Etype (Return_Obj_Access, Acc_Type);
Set_Can_Never_Be_Null (Acc_Type, False);
-- It gets initialized to null, so we can't have that
-- When the result subtype is constrained, the return object is created
-- on the caller side, and access to it is passed to the function. This
-- optimization is disabled when the result subtype needs finalization
-- actions because the caller side allocation may result in undesirable
-- finalization. Consider the following example:
--
-- function Make_Lim_Ctrl return Lim_Ctrl is
-- begin
-- return Result : Lim_Ctrl := raise Program_Error do
-- null;
-- end return;
-- end Make_Lim_Ctrl;
--
-- Obj : Lim_Ctrl_Ptr := new Lim_Ctrl'(Make_Lim_Ctrl);
--
-- Even though the size of limited controlled type Lim_Ctrl is known,
-- allocating Obj at the caller side will chain Obj on Lim_Ctrl_Ptr's
-- finalization master. The subsequent call to Make_Lim_Ctrl will fail
-- during the initialization actions for Result, which implies that
-- Result (and Obj by extension) should not be finalized. However Obj
-- will be finalized when access type Lim_Ctrl_Ptr goes out of scope
-- since it is already attached on the related finalization master.
-- Here and in related routines, we must examine the full view of the
-- type, because the view at the point of call may differ from the
-- one in the function body, and the expansion mechanism depends on
-- the characteristics of the full view.
if Needs_BIP_Alloc_Form (Function_Id) then
Temp_Init := Empty;
-- Case of a user-defined storage pool. Pass an allocation parameter
-- indicating that the function should allocate its result in the
-- pool, and pass the pool. Use 'Unrestricted_Access because the
-- pool may not be aliased.
if Present (Associated_Storage_Pool (Acc_Type)) then
Alloc_Form := User_Storage_Pool;
Pool :=
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of
(Associated_Storage_Pool (Acc_Type), Loc),
Attribute_Name => Name_Unrestricted_Access);
-- No user-defined pool; pass an allocation parameter indicating that
-- the function should allocate its result on the heap.
else
Alloc_Form := Global_Heap;
Pool := Make_Null (No_Location);
end if;
-- The caller does not provide the return object in this case, so we
-- have to pass null for the object access actual.
Return_Obj_Actual := Empty;
else
-- Replace the initialized allocator of form "new T'(Func (...))"
-- with an uninitialized allocator of form "new T", where T is the
-- result subtype of the called function. The call to the function
-- is handled separately further below.
New_Allocator :=
Make_Allocator (Loc,
Expression => New_Occurrence_Of (Result_Subt, Loc));
Set_No_Initialization (New_Allocator);
-- Copy attributes to new allocator. Note that the new allocator
-- logically comes from source if the original one did, so copy the
-- relevant flag. This ensures proper treatment of the restriction
-- No_Implicit_Heap_Allocations in this case.
Set_Storage_Pool (New_Allocator, Storage_Pool (Allocator));
Set_Procedure_To_Call (New_Allocator, Procedure_To_Call (Allocator));
Set_Comes_From_Source (New_Allocator, Comes_From_Source (Allocator));
Rewrite (Allocator, New_Allocator);
-- Initial value of the temp is the result of the uninitialized
-- allocator. Unchecked_Convert is needed for T'Input where T is
-- derived from a controlled type.
Temp_Init := Relocate_Node (Allocator);
if Nkind (Function_Call) in
N_Type_Conversion | N_Unchecked_Type_Conversion
then
Temp_Init := Unchecked_Convert_To (Acc_Type, Temp_Init);
end if;
-- Indicate that caller allocates, and pass in the return object
Alloc_Form := Caller_Allocation;
Pool := Make_Null (No_Location);
Return_Obj_Actual := Unchecked_Convert_To
(Result_Subt,
Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (Return_Obj_Access, Loc)));
-- When the result subtype is unconstrained, the function itself must
-- perform the allocation of the return object, so we pass parameters
-- indicating that.
end if;
-- Declare the temp object
Insert_Action (Allocator,
Make_Object_Declaration (Loc,
Defining_Identifier => Return_Obj_Access,
Object_Definition => New_Occurrence_Of (Acc_Type, Loc),
Expression => Temp_Init));
Ref_Func_Call := Make_Reference (Loc, Func_Call);
-- Ada 2005 (AI-251): If the type of the allocator is an interface
-- then generate an implicit conversion to force displacement of the
-- "this" pointer.
if Is_Interface (Designated_Type (Acc_Type)) then
Rewrite
(Ref_Func_Call,
OK_Convert_To (Acc_Type, Ref_Func_Call));
-- If the types are incompatible, we need an unchecked conversion. Note
-- that the full types will be compatible, but the types not visibly
-- compatible.
elsif Nkind (Function_Call)
in N_Type_Conversion | N_Unchecked_Type_Conversion
then
Ref_Func_Call := Unchecked_Convert_To (Acc_Type, Ref_Func_Call);
end if;
declare
Assign : constant Node_Id :=
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Return_Obj_Access, Loc),
Expression => Ref_Func_Call);
-- Assign the result of the function call into the temp. In the
-- caller-allocates case, this is overwriting the temp with its
-- initial value, which has no effect. In the callee-allocates case,
-- this is setting the temp to point to the object allocated by the
-- callee. Unchecked_Convert is needed for T'Input where T is derived
-- from a controlled type.
Actions : List_Id;
-- Actions to be inserted. If there are no tasks, this is just the
-- assignment statement. If the allocated object has tasks, we need
-- to wrap the assignment in a block that activates them. The
-- activation chain of that block must be passed to the function,
-- rather than some outer chain.
begin
if Might_Have_Tasks (Result_Subt) then
Actions := New_List;
Build_Task_Allocate_Block_With_Init_Stmts
(Actions, Allocator, Init_Stmts => New_List (Assign));
Chain := Activation_Chain_Entity (Last (Actions));
else
Actions := New_List (Assign);
Chain := Empty;
end if;
Insert_Actions (Allocator, Actions);
end;
-- When the function has a controlling result, an allocation-form
-- parameter must be passed indicating that the caller is allocating
-- the result object. This is needed because such a function can be
-- called as a dispatching operation and must be treated similarly
-- to functions with unconstrained result subtypes.
Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Alloc_Form, Pool_Actual => Pool);
Add_Finalization_Master_Actual_To_Build_In_Place_Call
(Func_Call, Function_Id, Acc_Type);
Add_Task_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type),
Chain => Chain);
-- Add an implicit actual to the function call that provides access
-- to the allocated object. An unchecked conversion to the (specific)
-- result subtype of the function is inserted to handle cases where
-- the access type of the allocator has a class-wide designated type.
Add_Access_Actual_To_Build_In_Place_Call
(Func_Call, Function_Id, Return_Obj_Actual);
-- Finally, replace the allocator node with a reference to the temp
Rewrite (Allocator, New_Occurrence_Of (Return_Obj_Access, Loc));
Analyze_And_Resolve (Allocator, Acc_Type);
pragma Assert (Check_Number_Of_Actuals (Func_Call, Function_Id));
pragma Assert (Check_BIP_Actuals (Func_Call, Function_Id));
end Make_Build_In_Place_Call_In_Allocator;
---------------------------------------------------
-- Make_Build_In_Place_Call_In_Anonymous_Context --
---------------------------------------------------
procedure Make_Build_In_Place_Call_In_Anonymous_Context
(Function_Call : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Function_Call);
Func_Call : constant Node_Id := Unqual_Conv (Function_Call);
Function_Id : Entity_Id;
Result_Subt : Entity_Id;
Return_Obj_Id : Entity_Id;
Return_Obj_Decl : Entity_Id;
begin
-- If the call has already been processed to add build-in-place actuals
-- then return. One place this can occur is for calls to build-in-place
-- functions that occur within a call to a protected operation, where
-- due to rewriting and expansion of the protected call there can be
-- more than one call to Expand_Actuals for the same set of actuals.
if Is_Expanded_Build_In_Place_Call (Func_Call) then
return;
end if;
-- Mark the call as processed as a build-in-place call
Set_Is_Expanded_Build_In_Place_Call (Func_Call);
if Is_Entity_Name (Name (Func_Call)) then
Function_Id := Entity (Name (Func_Call));
elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
Function_Id := Etype (Name (Func_Call));
else
raise Program_Error;
end if;
Warn_BIP (Func_Call);
Result_Subt := Etype (Function_Id);
-- If the build-in-place function returns a controlled object, then the
-- object needs to be finalized immediately after the context. Since
-- this case produces a transient scope, the servicing finalizer needs
-- to name the returned object. Create a temporary which is initialized
-- with the function call:
--
-- Temp_Id : Func_Type := BIP_Func_Call;
--
-- The initialization expression of the temporary will be rewritten by
-- the expander using the appropriate mechanism in Make_Build_In_Place_
-- Call_In_Object_Declaration.
if Needs_Finalization (Result_Subt) then
declare
Temp_Id : constant Entity_Id := Make_Temporary (Loc, 'R');
Temp_Decl : Node_Id;
begin
-- Reset the guard on the function call since the following does
-- not perform actual call expansion.
Set_Is_Expanded_Build_In_Place_Call (Func_Call, False);
Temp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp_Id,
Object_Definition =>
New_Occurrence_Of (Result_Subt, Loc),
Expression =>
New_Copy_Tree (Function_Call));
Insert_Action (Function_Call, Temp_Decl);
Rewrite (Function_Call, New_Occurrence_Of (Temp_Id, Loc));
Analyze (Function_Call);
end;
-- When the result subtype is definite, an object of the subtype is
-- declared and an access value designating it is passed as an actual.
elsif Caller_Known_Size (Func_Call, Result_Subt) then
-- Create a temporary object to hold the function result
Return_Obj_Id := Make_Temporary (Loc, 'R');
Set_Etype (Return_Obj_Id, Result_Subt);
Return_Obj_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Return_Obj_Id,
Aliased_Present => True,
Object_Definition => New_Occurrence_Of (Result_Subt, Loc));
Set_No_Initialization (Return_Obj_Decl);
Insert_Action (Func_Call, Return_Obj_Decl);
-- When the function has a controlling result, an allocation-form
-- parameter must be passed indicating that the caller is allocating
-- the result object. This is needed because such a function can be
-- called as a dispatching operation and must be treated similarly
-- to functions with unconstrained result subtypes.
Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
Add_Finalization_Master_Actual_To_Build_In_Place_Call
(Func_Call, Function_Id);
Add_Task_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
-- Add an implicit actual to the function call that provides access
-- to the caller's return object.
Add_Access_Actual_To_Build_In_Place_Call
(Func_Call, Function_Id, New_Occurrence_Of (Return_Obj_Id, Loc));
pragma Assert (Check_Number_Of_Actuals (Func_Call, Function_Id));
pragma Assert (Check_BIP_Actuals (Func_Call, Function_Id));
-- When the result subtype is unconstrained, the function must allocate
-- the return object in the secondary stack, so appropriate implicit
-- parameters are added to the call to indicate that. A transient
-- scope is established to ensure eventual cleanup of the result.
else
-- Pass an allocation parameter indicating that the function should
-- allocate its result on the secondary stack.
Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
Add_Finalization_Master_Actual_To_Build_In_Place_Call
(Func_Call, Function_Id);
Add_Task_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
-- Pass a null value to the function since no return object is
-- available on the caller side.
Add_Access_Actual_To_Build_In_Place_Call
(Func_Call, Function_Id, Empty);
pragma Assert (Check_Number_Of_Actuals (Func_Call, Function_Id));
pragma Assert (Check_BIP_Actuals (Func_Call, Function_Id));
end if;
end Make_Build_In_Place_Call_In_Anonymous_Context;
--------------------------------------------
-- Make_Build_In_Place_Call_In_Assignment --
--------------------------------------------
procedure Make_Build_In_Place_Call_In_Assignment
(Assign : Node_Id;
Function_Call : Node_Id)
is
Func_Call : constant Node_Id := Unqual_Conv (Function_Call);
Lhs : constant Node_Id := Name (Assign);
Loc : constant Source_Ptr := Sloc (Function_Call);
Func_Id : Entity_Id;
Obj_Decl : Node_Id;
Obj_Id : Entity_Id;
Ptr_Typ : Entity_Id;
Ptr_Typ_Decl : Node_Id;
New_Expr : Node_Id;
Result_Subt : Entity_Id;
begin
-- Mark the call as processed as a build-in-place call
pragma Assert (not Is_Expanded_Build_In_Place_Call (Func_Call));
Set_Is_Expanded_Build_In_Place_Call (Func_Call);
if Is_Entity_Name (Name (Func_Call)) then
Func_Id := Entity (Name (Func_Call));
elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
Func_Id := Etype (Name (Func_Call));
else
raise Program_Error;
end if;
Warn_BIP (Func_Call);
Result_Subt := Etype (Func_Id);
-- When the result subtype is unconstrained, an additional actual must
-- be passed to indicate that the caller is providing the return object.
-- This parameter must also be passed when the called function has a
-- controlling result, because dispatching calls to the function needs
-- to be treated effectively the same as calls to class-wide functions.
Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Func_Id, Alloc_Form => Caller_Allocation);
Add_Finalization_Master_Actual_To_Build_In_Place_Call
(Func_Call, Func_Id);
Add_Task_Actuals_To_Build_In_Place_Call
(Func_Call, Func_Id, Make_Identifier (Loc, Name_uMaster));
-- Add an implicit actual to the function call that provides access to
-- the caller's return object.
Add_Access_Actual_To_Build_In_Place_Call
(Func_Call, Func_Id, Unchecked_Convert_To (Result_Subt, Lhs));
-- Create an access type designating the function's result subtype
Ptr_Typ := Make_Temporary (Loc, 'A');
Ptr_Typ_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 (Result_Subt, Loc)));
Insert_After_And_Analyze (Assign, Ptr_Typ_Decl);
-- Finally, create an access object initialized to a reference to the
-- function call. We know this access value is non-null, so mark the
-- entity accordingly to suppress junk access checks.
New_Expr := Make_Reference (Loc, Relocate_Node (Func_Call));
-- Add a conversion if it's the wrong type
New_Expr := Unchecked_Convert_To (Ptr_Typ, New_Expr);
Obj_Id := Make_Temporary (Loc, 'R', New_Expr);
Set_Etype (Obj_Id, Ptr_Typ);
Set_Is_Known_Non_Null (Obj_Id);
Obj_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Obj_Id,
Object_Definition => New_Occurrence_Of (Ptr_Typ, Loc),
Expression => New_Expr);
Insert_After_And_Analyze (Ptr_Typ_Decl, Obj_Decl);
Rewrite (Assign, Make_Null_Statement (Loc));
pragma Assert (Check_Number_Of_Actuals (Func_Call, Func_Id));
pragma Assert (Check_BIP_Actuals (Func_Call, Func_Id));
end Make_Build_In_Place_Call_In_Assignment;
----------------------------------------------------
-- Make_Build_In_Place_Call_In_Object_Declaration --
----------------------------------------------------
procedure Make_Build_In_Place_Call_In_Object_Declaration
(Obj_Decl : Node_Id;
Function_Call : Node_Id)
is
function Get_Function_Id (Func_Call : Node_Id) return Entity_Id;
-- Get the value of Function_Id, below
---------------------
-- Get_Function_Id --
---------------------
function Get_Function_Id (Func_Call : Node_Id) return Entity_Id is
begin
if Is_Entity_Name (Name (Func_Call)) then
return Entity (Name (Func_Call));
elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
return Etype (Name (Func_Call));
else
raise Program_Error;
end if;
end Get_Function_Id;
-- Local variables
Func_Call : constant Node_Id := Unqual_Conv (Function_Call);
Function_Id : constant Entity_Id := Get_Function_Id (Func_Call);
Loc : constant Source_Ptr := Sloc (Function_Call);
Obj_Loc : constant Source_Ptr := Sloc (Obj_Decl);
Obj_Def_Id : constant Entity_Id := Defining_Identifier (Obj_Decl);
Obj_Typ : constant Entity_Id := Etype (Obj_Def_Id);
Encl_Func : constant Entity_Id := Enclosing_Subprogram (Obj_Def_Id);
Result_Subt : constant Entity_Id := Etype (Function_Id);
Call_Deref : Node_Id;
Caller_Object : Node_Id;
Def_Id : Entity_Id;
Designated_Type : Entity_Id;
Fmaster_Actual : Node_Id := Empty;
Pool_Actual : Node_Id;
Ptr_Typ : Entity_Id;
Ptr_Typ_Decl : Node_Id;
Pass_Caller_Acc : Boolean := False;
Res_Decl : Node_Id;
Definite : constant Boolean :=
Caller_Known_Size (Func_Call, Result_Subt)
and then not Is_Class_Wide_Type (Obj_Typ);
-- In the case of "X : T'Class := F(...);", where F returns a
-- Caller_Known_Size (specific) tagged type, we treat it as
-- indefinite, because the code for the Definite case below sets the
-- initialization expression of the object to Empty, which would be
-- illegal Ada, and would cause gigi to misallocate X.
-- Start of processing for Make_Build_In_Place_Call_In_Object_Declaration
begin
-- If the call has already been processed to add build-in-place actuals
-- then return.
if Is_Expanded_Build_In_Place_Call (Func_Call) then
return;
end if;
-- Mark the call as processed as a build-in-place call
Set_Is_Expanded_Build_In_Place_Call (Func_Call);
Warn_BIP (Func_Call);
-- Create an access type designating the function's result subtype.
-- We use the type of the original call because it may be a call to an
-- inherited operation, which the expansion has replaced with the parent
-- operation that yields the parent type. Note that this access type
-- must be declared before we establish a transient scope, so that it
-- receives the proper accessibility level.
if Is_Class_Wide_Type (Obj_Typ)
and then not Is_Interface (Obj_Typ)
and then not Is_Class_Wide_Type (Etype (Function_Call))
then
Designated_Type := Obj_Typ;
else
Designated_Type := Etype (Function_Call);
end if;
Ptr_Typ := Make_Temporary (Loc, 'A');
Ptr_Typ_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 (Designated_Type, Loc)));
-- The access type and its accompanying object must be inserted after
-- the object declaration in the constrained case, so that the function
-- call can be passed access to the object. In the indefinite case, or
-- if the object declaration is for a return object, the access type and
-- object must be inserted before the object, since the object
-- declaration is rewritten to be a renaming of a dereference of the
-- access object. Note: we need to freeze Ptr_Typ explicitly, because
-- the result object is in a different (transient) scope, so won't cause
-- freezing.
if Definite and then not Is_Return_Object (Obj_Def_Id) then
-- The presence of an address clause complicates the build-in-place
-- expansion because the indicated address must be processed before
-- the indirect call is generated (including the definition of a
-- local pointer to the object). The address clause may come from
-- an aspect specification or from an explicit attribute
-- specification appearing after the object declaration. These two
-- cases require different processing.
if Has_Aspect (Obj_Def_Id, Aspect_Address) then
-- Skip non-delayed pragmas that correspond to other aspects, if
-- any, to find proper insertion point for freeze node of object.
declare
D : Node_Id := Obj_Decl;
N : Node_Id := Next (D);
begin
while Present (N)
and then Nkind (N) in N_Attribute_Reference | N_Pragma
loop
Analyze (N);
D := N;
Next (N);
end loop;
Insert_After (D, Ptr_Typ_Decl);
-- Freeze object before pointer declaration, to ensure that
-- generated attribute for address is inserted at the proper
-- place.
Freeze_Before (Ptr_Typ_Decl, Obj_Def_Id);
end;
Analyze (Ptr_Typ_Decl);
elsif Present (Following_Address_Clause (Obj_Decl)) then
-- Locate explicit address clause, which may also follow pragmas
-- generated by other aspect specifications.
declare
Addr : constant Node_Id := Following_Address_Clause (Obj_Decl);
D : Node_Id := Next (Obj_Decl);
begin
while Present (D) loop
Analyze (D);
exit when D = Addr;
Next (D);
end loop;
Insert_After_And_Analyze (Addr, Ptr_Typ_Decl);
end;
else
Insert_After_And_Analyze (Obj_Decl, Ptr_Typ_Decl);
end if;
else
Insert_Action (Obj_Decl, Ptr_Typ_Decl);
end if;
-- Force immediate freezing of Ptr_Typ because Res_Decl will be
-- elaborated in an inner (transient) scope and thus won't cause
-- freezing by itself. It's not an itype, but it needs to be frozen
-- inside the current subprogram (see Freeze_Outside in freeze.adb).
Freeze_Itype (Ptr_Typ, Ptr_Typ_Decl);
-- If the object is a return object of an enclosing build-in-place
-- function, then the implicit build-in-place parameters of the
-- enclosing function are simply passed along to the called function.
-- (Unfortunately, this won't cover the case of extension aggregates
-- where the ancestor part is a build-in-place indefinite function
-- call that should be passed along the caller's parameters.
-- Currently those get mishandled by reassigning the result of the
-- call to the aggregate return object, when the call result should
-- really be directly built in place in the aggregate and not in a
-- temporary. ???)
if Is_Return_Object (Obj_Def_Id) then
Pass_Caller_Acc := True;
-- When the enclosing function has a BIP_Alloc_Form formal then we
-- pass it along to the callee (such as when the enclosing function
-- has an unconstrained or tagged result type).
if Needs_BIP_Alloc_Form (Encl_Func) then
if RTE_Available (RE_Root_Storage_Pool_Ptr) then
Pool_Actual :=
New_Occurrence_Of
(Build_In_Place_Formal
(Encl_Func, BIP_Storage_Pool), Loc);
-- The build-in-place pool formal is not built on e.g. ZFP
else
Pool_Actual := Empty;
end if;
Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Function_Call => Func_Call,
Function_Id => Function_Id,
Alloc_Form_Exp =>
New_Occurrence_Of
(Build_In_Place_Formal (Encl_Func, BIP_Alloc_Form), Loc),
Pool_Actual => Pool_Actual);
-- Otherwise, if enclosing function has a definite result subtype,
-- then caller allocation will be used.
else
Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
end if;
if Needs_BIP_Finalization_Master (Encl_Func) then
Fmaster_Actual :=
New_Occurrence_Of
(Build_In_Place_Formal
(Encl_Func, BIP_Finalization_Master), Loc);
end if;
-- Retrieve the BIPacc formal from the enclosing function and convert
-- it to the access type of the callee's BIP_Object_Access formal.
Caller_Object :=
Unchecked_Convert_To
(Etype (Build_In_Place_Formal (Function_Id, BIP_Object_Access)),
New_Occurrence_Of
(Build_In_Place_Formal (Encl_Func, BIP_Object_Access), Loc));
-- In the definite case, add an implicit actual to the function call
-- that provides access to the declared object. An unchecked conversion
-- to the (specific) result type of the function is inserted to handle
-- the case where the object is declared with a class-wide type.
elsif Definite then
Caller_Object := Unchecked_Convert_To
(Result_Subt, New_Occurrence_Of (Obj_Def_Id, Loc));
-- When the function has a controlling result, an allocation-form
-- parameter must be passed indicating that the caller is allocating
-- the result object. This is needed because such a function can be
-- called as a dispatching operation and must be treated similarly to
-- functions with indefinite result subtypes.
Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
-- The allocation for indefinite library-level objects occurs on the
-- heap as opposed to the secondary stack. This accommodates DLLs where
-- the secondary stack is destroyed after each library unload. This is a
-- hybrid mechanism where a stack-allocated object lives on the heap.
elsif Is_Library_Level_Entity (Obj_Def_Id)
and then not Restriction_Active (No_Implicit_Heap_Allocations)
then
Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Alloc_Form => Global_Heap);
Caller_Object := Empty;
-- Create a finalization master for the access result type to ensure
-- that the heap allocation can properly chain the object and later
-- finalize it when the library unit goes out of scope.
if Needs_Finalization (Etype (Func_Call)) then
Build_Finalization_Master
(Typ => Ptr_Typ,
For_Lib_Level => True,
Insertion_Node => Ptr_Typ_Decl);
Fmaster_Actual :=
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Finalization_Master (Ptr_Typ), Loc),
Attribute_Name => Name_Unrestricted_Access);
end if;
-- In other indefinite cases, pass an indication to do the allocation
-- on the secondary stack and set Caller_Object to Empty so that a null
-- value will be passed for the caller's object address. A transient
-- scope is established to ensure eventual cleanup of the result.
else
Add_Unconstrained_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
Caller_Object := Empty;
Establish_Transient_Scope (Obj_Decl, Manage_Sec_Stack => True);
end if;
-- Pass along any finalization master actual, which is needed in the
-- case where the called function initializes a return object of an
-- enclosing build-in-place function.
Add_Finalization_Master_Actual_To_Build_In_Place_Call
(Func_Call => Func_Call,
Func_Id => Function_Id,
Master_Exp => Fmaster_Actual);
if Nkind (Parent (Obj_Decl)) = N_Extended_Return_Statement
and then Needs_BIP_Task_Actuals (Function_Id)
then
-- Here we're passing along the master that was passed in to this
-- function.
Add_Task_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id,
Master_Actual =>
New_Occurrence_Of
(Build_In_Place_Formal (Encl_Func, BIP_Task_Master), Loc));
else
Add_Task_Actuals_To_Build_In_Place_Call
(Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
end if;
Add_Access_Actual_To_Build_In_Place_Call
(Func_Call,
Function_Id,
Caller_Object,
Is_Access => Pass_Caller_Acc);
-- Finally, create an access object initialized to a reference to the
-- function call. We know this access value cannot be null, so mark the
-- entity accordingly to suppress the access check. We need to suppress
-- warnings, because this can be part of the expansion of "for ... of"
-- and similar constructs that generate finalization actions. Such
-- finalization actions are safe, because they check a count that
-- indicates which objects should be finalized, but the back end
-- nonetheless warns about uninitialized objects.
Def_Id := Make_Temporary (Loc, 'R', Func_Call);
Set_Warnings_Off (Def_Id);
Set_Etype (Def_Id, Ptr_Typ);
Set_Is_Known_Non_Null (Def_Id);
if Nkind (Function_Call) in N_Type_Conversion
| N_Unchecked_Type_Conversion
then
Res_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (Ptr_Typ, Loc),
Expression =>
Unchecked_Convert_To
(Ptr_Typ, Make_Reference (Loc, Relocate_Node (Func_Call))));
else
Res_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (Ptr_Typ, Loc),
Expression =>
Make_Reference (Loc, Relocate_Node (Func_Call)));
end if;
Insert_After_And_Analyze (Ptr_Typ_Decl, Res_Decl);
-- If the result subtype of the called function is definite and is not
-- itself the return expression of an enclosing BIP function, then mark
-- the object as having no initialization.
if Definite and then not Is_Return_Object (Obj_Def_Id) then
-- The related object declaration is encased in a transient block
-- because the build-in-place function call contains at least one
-- nested function call that produces a controlled transient
-- temporary:
-- Obj : ... := BIP_Func_Call (Ctrl_Func_Call);
-- Since the build-in-place expansion decouples the call from the
-- object declaration, the finalization machinery lacks the context
-- which prompted the generation of the transient block. To resolve
-- this scenario, store the build-in-place call.
if Scope_Is_Transient then
Set_BIP_Initialization_Call (Obj_Def_Id, Res_Decl);
end if;
Set_Expression (Obj_Decl, Empty);
Set_No_Initialization (Obj_Decl);
-- In case of an indefinite result subtype, or if the call is the
-- return expression of an enclosing BIP function, rewrite the object
-- declaration as an object renaming where the renamed object is a
-- dereference of <function_Call>'reference:
--
-- Obj : Subt renames <function_call>'Ref.all;
else
Call_Deref :=
Make_Explicit_Dereference (Obj_Loc,
Prefix => New_Occurrence_Of (Def_Id, Obj_Loc));
Rewrite (Obj_Decl,
Make_Object_Renaming_Declaration (Obj_Loc,
Defining_Identifier => Make_Temporary (Obj_Loc, 'D'),
Subtype_Mark =>
New_Occurrence_Of (Designated_Type, Obj_Loc),
Name => Call_Deref));
-- At this point, Defining_Identifier (Obj_Decl) is no longer equal
-- to Obj_Def_Id.
Set_Renamed_Object (Defining_Identifier (Obj_Decl), Call_Deref);
-- If the original entity comes from source, then mark the new
-- entity as needing debug information, even though it's defined
-- by a generated renaming that does not come from source, so that
-- the Materialize_Entity flag will be set on the entity when
-- Debug_Renaming_Declaration is called during analysis.
if Comes_From_Source (Obj_Def_Id) then
Set_Debug_Info_Needed (Defining_Identifier (Obj_Decl));
end if;
Analyze (Obj_Decl);
Replace_Renaming_Declaration_Id
(Obj_Decl, Original_Node (Obj_Decl));
end if;
pragma Assert (Check_Number_Of_Actuals (Func_Call, Function_Id));
pragma Assert (Check_BIP_Actuals (Func_Call, Function_Id));
end Make_Build_In_Place_Call_In_Object_Declaration;
-------------------------------------------------
-- Make_Build_In_Place_Iface_Call_In_Allocator --
-------------------------------------------------
procedure Make_Build_In_Place_Iface_Call_In_Allocator
(Allocator : Node_Id;
Function_Call : Node_Id)
is
BIP_Func_Call : constant Node_Id :=
Unqual_BIP_Iface_Function_Call (Function_Call);
Loc : constant Source_Ptr := Sloc (Function_Call);
Anon_Type : Entity_Id;
Tmp_Decl : Node_Id;
Tmp_Id : Entity_Id;
begin
-- No action if the call has already been processed
if Is_Expanded_Build_In_Place_Call (BIP_Func_Call) then
return;
end if;
Tmp_Id := Make_Temporary (Loc, 'D');
-- Insert a temporary before N initialized with the BIP function call
-- without its enclosing type conversions and analyze it without its
-- expansion. This temporary facilitates us reusing the BIP machinery,
-- which takes care of adding the extra build-in-place actuals and
-- transforms this object declaration into an object renaming
-- declaration.
Anon_Type := Create_Itype (E_Anonymous_Access_Type, Function_Call);
Set_Directly_Designated_Type (Anon_Type, Etype (BIP_Func_Call));
Set_Etype (Anon_Type, Anon_Type);
Build_Class_Wide_Master (Anon_Type);
Tmp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Tmp_Id,
Object_Definition => New_Occurrence_Of (Anon_Type, Loc),
Expression =>
Make_Allocator (Loc,
Expression =>
Make_Qualified_Expression (Loc,
Subtype_Mark =>
New_Occurrence_Of (Etype (BIP_Func_Call), Loc),
Expression => New_Copy_Tree (BIP_Func_Call))));
-- Manually set the associated node for the anonymous access type to
-- be its local declaration, to avoid confusing and complicating
-- the accessibility machinery.
Set_Associated_Node_For_Itype (Anon_Type, Tmp_Decl);
Expander_Mode_Save_And_Set (False);
Insert_Action (Allocator, Tmp_Decl);
Expander_Mode_Restore;
Make_Build_In_Place_Call_In_Allocator
(Allocator => Expression (Tmp_Decl),
Function_Call => Expression (Expression (Tmp_Decl)));
-- Add a conversion to displace the pointer to the allocated object
-- to reference the corresponding dispatch table.
Rewrite (Allocator,
Convert_To (Etype (Allocator),
New_Occurrence_Of (Tmp_Id, Loc)));
end Make_Build_In_Place_Iface_Call_In_Allocator;
---------------------------------------------------------
-- Make_Build_In_Place_Iface_Call_In_Anonymous_Context --
---------------------------------------------------------
procedure Make_Build_In_Place_Iface_Call_In_Anonymous_Context
(Function_Call : Node_Id)
is
BIP_Func_Call : constant Node_Id :=
Unqual_BIP_Iface_Function_Call (Function_Call);
Loc : constant Source_Ptr := Sloc (Function_Call);
Tmp_Decl : Node_Id;
Tmp_Id : Entity_Id;
begin
-- No action of the call has already been processed
if Is_Expanded_Build_In_Place_Call (BIP_Func_Call) then
return;
end if;
pragma Assert (Needs_Finalization (Etype (BIP_Func_Call)));
-- Insert a temporary before the call initialized with function call to
-- reuse the BIP machinery which takes care of adding the extra build-in
-- place actuals and transforms this object declaration into an object
-- renaming declaration.
Tmp_Id := Make_Temporary (Loc, 'D');
Tmp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Tmp_Id,
Object_Definition =>
New_Occurrence_Of (Etype (Function_Call), Loc),
Expression => Relocate_Node (Function_Call));
Expander_Mode_Save_And_Set (False);
Insert_Action (Function_Call, Tmp_Decl);
Expander_Mode_Restore;
Make_Build_In_Place_Iface_Call_In_Object_Declaration
(Obj_Decl => Tmp_Decl,
Function_Call => Expression (Tmp_Decl));
end Make_Build_In_Place_Iface_Call_In_Anonymous_Context;
----------------------------------------------------------
-- Make_Build_In_Place_Iface_Call_In_Object_Declaration --
----------------------------------------------------------
procedure Make_Build_In_Place_Iface_Call_In_Object_Declaration
(Obj_Decl : Node_Id;
Function_Call : Node_Id)
is
BIP_Func_Call : constant Node_Id :=
Unqual_BIP_Iface_Function_Call (Function_Call);
Loc : constant Source_Ptr := Sloc (Function_Call);
Obj_Id : constant Entity_Id := Defining_Entity (Obj_Decl);
Tmp_Decl : Node_Id;
Tmp_Id : Entity_Id;
begin
-- No action of the call has already been processed
if Is_Expanded_Build_In_Place_Call (BIP_Func_Call) then
return;
end if;
Tmp_Id := Make_Temporary (Loc, 'D');
-- Insert a temporary before N initialized with the BIP function call
-- without its enclosing type conversions and analyze it without its
-- expansion. This temporary facilitates us reusing the BIP machinery,
-- which takes care of adding the extra build-in-place actuals and
-- transforms this object declaration into an object renaming
-- declaration.
Tmp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Tmp_Id,
Object_Definition =>
New_Occurrence_Of (Etype (BIP_Func_Call), Loc),
Expression => New_Copy_Tree (BIP_Func_Call));
Expander_Mode_Save_And_Set (False);
Insert_Action (Obj_Decl, Tmp_Decl);
Expander_Mode_Restore;
Make_Build_In_Place_Call_In_Object_Declaration
(Obj_Decl => Tmp_Decl,
Function_Call => Expression (Tmp_Decl));
pragma Assert (Nkind (Tmp_Decl) = N_Object_Renaming_Declaration);
-- Replace the original build-in-place function call by a reference to
-- the resulting temporary object renaming declaration. In this way,
-- all the interface conversions performed in the original Function_Call
-- on the build-in-place object are preserved.
Rewrite (BIP_Func_Call, New_Occurrence_Of (Tmp_Id, Loc));
-- Replace the original object declaration by an internal object
-- renaming declaration. This leaves the generated code more clean (the
-- build-in-place function call in an object renaming declaration and
-- displacements of the pointer to the build-in-place object in another
-- renaming declaration) and allows us to invoke the routine that takes
-- care of replacing the identifier of the renaming declaration (routine
-- originally developed for the regular build-in-place management).
Rewrite (Obj_Decl,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Make_Temporary (Loc, 'D'),
Subtype_Mark => New_Occurrence_Of (Etype (Obj_Id), Loc),
Name => Function_Call));
Analyze (Obj_Decl);
Replace_Renaming_Declaration_Id (Obj_Decl, Original_Node (Obj_Decl));
end Make_Build_In_Place_Iface_Call_In_Object_Declaration;
--------------------------------------------
-- Make_CPP_Constructor_Call_In_Allocator --
--------------------------------------------
procedure Make_CPP_Constructor_Call_In_Allocator
(Allocator : Node_Id;
Function_Call : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Function_Call);
Acc_Type : constant Entity_Id := Etype (Allocator);
Function_Id : constant Entity_Id := Entity (Name (Function_Call));
Result_Subt : constant Entity_Id := Available_View (Etype (Function_Id));
New_Allocator : Node_Id;
Return_Obj_Access : Entity_Id;
Tmp_Obj : Node_Id;
begin
pragma Assert (Nkind (Allocator) = N_Allocator
and then Nkind (Function_Call) = N_Function_Call);
pragma Assert (Convention (Function_Id) = Convention_CPP
and then Is_Constructor (Function_Id));
pragma Assert (Is_Constrained (Underlying_Type (Result_Subt)));
-- Replace the initialized allocator of form "new T'(Func (...))" with
-- an uninitialized allocator of form "new T", where T is the result
-- subtype of the called function. The call to the function is handled
-- separately further below.
New_Allocator :=
Make_Allocator (Loc,
Expression => New_Occurrence_Of (Result_Subt, Loc));
Set_No_Initialization (New_Allocator);
-- Copy attributes to new allocator. Note that the new allocator
-- logically comes from source if the original one did, so copy the
-- relevant flag. This ensures proper treatment of the restriction
-- No_Implicit_Heap_Allocations in this case.
Set_Storage_Pool (New_Allocator, Storage_Pool (Allocator));
Set_Procedure_To_Call (New_Allocator, Procedure_To_Call (Allocator));
Set_Comes_From_Source (New_Allocator, Comes_From_Source (Allocator));
Rewrite (Allocator, New_Allocator);
-- Create a new access object and initialize it to the result of the
-- new uninitialized allocator. Note: we do not use Allocator as the
-- Related_Node of Return_Obj_Access in call to Make_Temporary below
-- as this would create a sort of infinite "recursion".
Return_Obj_Access := Make_Temporary (Loc, 'R');
Set_Etype (Return_Obj_Access, Acc_Type);
-- Generate:
-- Rnnn : constant ptr_T := new (T);
-- Init (Rnn.all,...);
Tmp_Obj :=
Make_Object_Declaration (Loc,
Defining_Identifier => Return_Obj_Access,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (Acc_Type, Loc),
Expression => Relocate_Node (Allocator));
Insert_Action (Allocator, Tmp_Obj);
Insert_List_After_And_Analyze (Tmp_Obj,
Build_Initialization_Call (Loc,
Id_Ref =>
Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (Return_Obj_Access, Loc)),
Typ => Etype (Function_Id),
Constructor_Ref => Function_Call));
-- Finally, replace the allocator node with a reference to the result of
-- the function call itself (which will effectively be an access to the
-- object created by the allocator).
Rewrite (Allocator, New_Occurrence_Of (Return_Obj_Access, Loc));
-- Ada 2005 (AI-251): If the type of the allocator is an interface then
-- generate an implicit conversion to force displacement of the "this"
-- pointer.
if Is_Interface (Designated_Type (Acc_Type)) then
Rewrite (Allocator, Convert_To (Acc_Type, Relocate_Node (Allocator)));
end if;
Analyze_And_Resolve (Allocator, Acc_Type);
end Make_CPP_Constructor_Call_In_Allocator;
----------------------
-- Might_Have_Tasks --
----------------------
function Might_Have_Tasks (Typ : Entity_Id) return Boolean is
begin
return not Global_No_Tasking
and then not No_Run_Time_Mode
and then (Has_Task (Typ)
or else (Is_Class_Wide_Type (Typ)
and then Is_Limited_Record (Typ)
and then not Has_Aspect
(Etype (Typ), Aspect_No_Task_Parts)));
end Might_Have_Tasks;
----------------------------
-- Needs_BIP_Task_Actuals --
----------------------------
function Needs_BIP_Task_Actuals (Func_Id : Entity_Id) return Boolean is
pragma Assert (Is_Build_In_Place_Function (Func_Id));
Subp_Id : Entity_Id;
Func_Typ : Entity_Id;
begin
if Global_No_Tasking or else No_Run_Time_Mode then
return False;
end if;
-- For thunks we must rely on their target entity; otherwise, given that
-- the profile of thunks for functions returning a limited interface
-- type returns a class-wide type, we would erroneously add these extra
-- formals.
if Is_Thunk (Func_Id) then
Subp_Id := Thunk_Entity (Func_Id);
-- Common case
else
Subp_Id := Func_Id;
end if;
Func_Typ := Underlying_Type (Etype (Subp_Id));
-- At first sight, for all the following cases, we could add assertions
-- to ensure that if Func_Id is frozen then the computed result matches
-- with the availability of the task master extra formal; unfortunately
-- this is not feasible because we may be precisely freezing this entity
-- (that is, Is_Frozen has been set by Freeze_Entity but it has not
-- completed its work).
if Has_Task (Func_Typ) then
return True;
elsif Ekind (Func_Id) = E_Function then
return Might_Have_Tasks (Func_Typ);
-- Handle subprogram type internally generated for dispatching call. We
-- cannot rely on the return type of the subprogram type of dispatching
-- calls since it is always a class-wide type (cf. Expand_Dispatching_
-- Call).
elsif Ekind (Func_Id) = E_Subprogram_Type then
if Is_Dispatch_Table_Entity (Func_Id) then
return Has_BIP_Extra_Formal (Func_Id, BIP_Task_Master);
else
return Might_Have_Tasks (Func_Typ);
end if;
else
raise Program_Error;
end if;
end Needs_BIP_Task_Actuals;
-----------------------------------
-- Needs_BIP_Finalization_Master --
-----------------------------------
function Needs_BIP_Finalization_Master
(Func_Id : Entity_Id) return Boolean
is
pragma Assert (Is_Build_In_Place_Function (Func_Id));
Func_Typ : constant Entity_Id := Underlying_Type (Etype (Func_Id));
begin
-- A formal giving the finalization master is needed for build-in-place
-- functions whose result type needs finalization or is a tagged type.
-- Tagged primitive build-in-place functions need such a formal because
-- they can be called by a dispatching call, and extensions may require
-- finalization even if the root type doesn't. This means they're also
-- needed for tagged nonprimitive build-in-place functions with tagged
-- results, since such functions can be called via access-to-function
-- types, and those can be used to call primitives, so masters have to
-- be passed to all such build-in-place functions, primitive or not.
return
not Restriction_Active (No_Finalization)
and then (Needs_Finalization (Func_Typ)
or else Is_Tagged_Type (Func_Typ));
end Needs_BIP_Finalization_Master;
--------------------------
-- Needs_BIP_Alloc_Form --
--------------------------
function Needs_BIP_Alloc_Form (Func_Id : Entity_Id) return Boolean is
pragma Assert (Is_Build_In_Place_Function (Func_Id));
Func_Typ : constant Entity_Id := Underlying_Type (Etype (Func_Id));
begin
return Requires_Transient_Scope (Func_Typ);
end Needs_BIP_Alloc_Form;
-------------------------------------
-- Replace_Renaming_Declaration_Id --
-------------------------------------
procedure Replace_Renaming_Declaration_Id
(New_Decl : Node_Id;
Orig_Decl : Node_Id)
is
New_Id : constant Entity_Id := Defining_Entity (New_Decl);
Orig_Id : constant Entity_Id := Defining_Entity (Orig_Decl);
begin
Set_Chars (New_Id, Chars (Orig_Id));
-- Swap next entity links in preparation for exchanging entities
declare
Next_Id : constant Entity_Id := Next_Entity (New_Id);
begin
Link_Entities (New_Id, Next_Entity (Orig_Id));
Link_Entities (Orig_Id, Next_Id);
end;
Set_Homonym (New_Id, Homonym (Orig_Id));
Exchange_Entities (New_Id, Orig_Id);
-- Preserve source indication of original declaration, so that xref
-- information is properly generated for the right entity.
Preserve_Comes_From_Source (New_Decl, Orig_Decl);
Preserve_Comes_From_Source (Orig_Id, Orig_Decl);
Set_Comes_From_Source (New_Id, False);
end Replace_Renaming_Declaration_Id;
---------------------------------
-- Rewrite_Function_Call_For_C --
---------------------------------
procedure Rewrite_Function_Call_For_C (N : Node_Id) is
Orig_Func : constant Entity_Id := Entity (Name (N));
Func_Id : constant Entity_Id := Ultimate_Alias (Orig_Func);
Par : constant Node_Id := Parent (N);
Proc_Id : constant Entity_Id := Corresponding_Procedure (Func_Id);
Loc : constant Source_Ptr := Sloc (Par);
Actuals : List_Id;
Last_Actual : Node_Id;
Last_Formal : Entity_Id;
-- Start of processing for Rewrite_Function_Call_For_C
begin
-- The actuals may be given by named associations, so the added actual
-- that is the target of the return value of the call must be a named
-- association as well, so we retrieve the name of the generated
-- out_formal.
Last_Formal := First_Formal (Proc_Id);
while Present (Next_Formal (Last_Formal)) loop
Next_Formal (Last_Formal);
end loop;
Actuals := Parameter_Associations (N);
-- The original function may lack parameters
if No (Actuals) then
Actuals := New_List;
end if;
-- If the function call is the expression of an assignment statement,
-- transform the assignment into a procedure call. Generate:
-- LHS := Func_Call (...);
-- Proc_Call (..., LHS);
-- If function is inherited, a conversion may be necessary.
if Nkind (Par) = N_Assignment_Statement then
Last_Actual := Name (Par);
if not Comes_From_Source (Orig_Func)
and then Etype (Orig_Func) /= Etype (Func_Id)
then
Last_Actual :=
Make_Type_Conversion (Loc,
New_Occurrence_Of (Etype (Func_Id), Loc),
Last_Actual);
end if;
Append_To (Actuals,
Make_Parameter_Association (Loc,
Selector_Name =>
Make_Identifier (Loc, Chars (Last_Formal)),
Explicit_Actual_Parameter => Last_Actual));
Rewrite (Par,
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Proc_Id, Loc),
Parameter_Associations => Actuals));
Analyze (Par);
-- Otherwise the context is an expression. Generate a temporary and a
-- procedure call to obtain the function result. Generate:
-- ... Func_Call (...) ...
-- Temp : ...;
-- Proc_Call (..., Temp);
-- ... Temp ...
else
declare
Temp_Id : constant Entity_Id := Make_Temporary (Loc, 'T');
Call : Node_Id;
Decl : Node_Id;
begin
-- Generate:
-- Temp : ...;
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp_Id,
Object_Definition =>
New_Occurrence_Of (Etype (Func_Id), Loc));
-- Generate:
-- Proc_Call (..., Temp);
Append_To (Actuals,
Make_Parameter_Association (Loc,
Selector_Name =>
Make_Identifier (Loc, Chars (Last_Formal)),
Explicit_Actual_Parameter =>
New_Occurrence_Of (Temp_Id, Loc)));
Call :=
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Proc_Id, Loc),
Parameter_Associations => Actuals);
Insert_Actions (Par, New_List (Decl, Call));
Rewrite (N, New_Occurrence_Of (Temp_Id, Loc));
end;
end if;
end Rewrite_Function_Call_For_C;
------------------------------------
-- Set_Enclosing_Sec_Stack_Return --
------------------------------------
procedure Set_Enclosing_Sec_Stack_Return (N : Node_Id) is
P : Node_Id := N;
begin
-- Due to a possible mix of internally generated blocks, source blocks
-- and loops, the scope stack may not be contiguous as all labels are
-- inserted at the top level within the related function. Instead,
-- perform a parent-based traversal and mark all appropriate constructs.
while Present (P) loop
-- Mark the label of a source or internally generated block or
-- loop.
if Nkind (P) in N_Block_Statement | N_Loop_Statement then
Set_Sec_Stack_Needed_For_Return (Entity (Identifier (P)));
-- Mark the enclosing function
elsif Nkind (P) = N_Subprogram_Body then
if Present (Corresponding_Spec (P)) then
Set_Sec_Stack_Needed_For_Return (Corresponding_Spec (P));
else
Set_Sec_Stack_Needed_For_Return (Defining_Entity (P));
end if;
-- Do not go beyond the enclosing function
exit;
end if;
P := Parent (P);
end loop;
end Set_Enclosing_Sec_Stack_Return;
------------------------------------
-- Unqual_BIP_Iface_Function_Call --
------------------------------------
function Unqual_BIP_Iface_Function_Call (Expr : Node_Id) return Node_Id is
Has_Pointer_Displacement : Boolean := False;
On_Object_Declaration : Boolean := False;
-- Remember if processing the renaming expressions on recursion we have
-- traversed an object declaration, since we can traverse many object
-- declaration renamings but just one regular object declaration.
function Unqual_BIP_Function_Call (Expr : Node_Id) return Node_Id;
-- Search for a build-in-place function call skipping any qualification
-- including qualified expressions, type conversions, references, calls
-- to displace the pointer to the object, and renamings. Return Empty if
-- no build-in-place function call is found.
------------------------------
-- Unqual_BIP_Function_Call --
------------------------------
function Unqual_BIP_Function_Call (Expr : Node_Id) return Node_Id is
begin
-- Recurse to handle case of multiple levels of qualification and/or
-- conversion.
if Nkind (Expr) in N_Qualified_Expression
| N_Type_Conversion
| N_Unchecked_Type_Conversion
then
return Unqual_BIP_Function_Call (Expression (Expr));
-- Recurse to handle case of multiple levels of references and
-- explicit dereferences.
elsif Nkind (Expr) in N_Attribute_Reference
| N_Explicit_Dereference
| N_Reference
then
return Unqual_BIP_Function_Call (Prefix (Expr));
-- Recurse on object renamings
elsif Nkind (Expr) = N_Identifier
and then Present (Entity (Expr))
and then Ekind (Entity (Expr)) in E_Constant | E_Variable
and then Nkind (Parent (Entity (Expr))) =
N_Object_Renaming_Declaration
and then Present (Renamed_Object (Entity (Expr)))
then
return Unqual_BIP_Function_Call (Renamed_Object (Entity (Expr)));
-- Recurse on the initializing expression of the first reference of
-- an object declaration.
elsif not On_Object_Declaration
and then Nkind (Expr) = N_Identifier
and then Present (Entity (Expr))
and then Ekind (Entity (Expr)) in E_Constant | E_Variable
and then Nkind (Parent (Entity (Expr))) = N_Object_Declaration
and then Present (Expression (Parent (Entity (Expr))))
then
On_Object_Declaration := True;
return
Unqual_BIP_Function_Call (Expression (Parent (Entity (Expr))));
-- Recurse to handle calls to displace the pointer to the object to
-- reference a secondary dispatch table.
elsif Nkind (Expr) = N_Function_Call
and then Nkind (Name (Expr)) in N_Has_Entity
and then Present (Entity (Name (Expr)))
and then Is_RTE (Entity (Name (Expr)), RE_Displace)
then
Has_Pointer_Displacement := True;
return
Unqual_BIP_Function_Call (First (Parameter_Associations (Expr)));
-- Normal case: check if the inner expression is a BIP function call
-- and the pointer to the object is displaced.
elsif Has_Pointer_Displacement
and then Is_Build_In_Place_Function_Call (Expr)
then
return Expr;
else
return Empty;
end if;
end Unqual_BIP_Function_Call;
-- Start of processing for Unqual_BIP_Iface_Function_Call
begin
if Nkind (Expr) = N_Identifier and then No (Entity (Expr)) then
-- Can happen for X'Elab_Spec in the binder-generated file
return Empty;
end if;
return Unqual_BIP_Function_Call (Expr);
end Unqual_BIP_Iface_Function_Call;
--------------
-- Warn_BIP --
--------------
procedure Warn_BIP (Func_Call : Node_Id) is
begin
if Debug_Flag_Underscore_BB then
Error_Msg_N ("build-in-place function call??", Func_Call);
end if;
end Warn_BIP;
end Exp_Ch6;