Google Git
Sign in
gnu / gcc / refs/heads/releases/gcc-4.8 / . / gcc / ada / exp_attr.adb
blob: 54442db72b4e7e899cc4fbaf4368b72178aa8103 [file] [log] [blame]
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ A T T R --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2013, 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 Checks; use Checks;
with Einfo; use Einfo;
with Elists; use Elists;
with Exp_Atag; use Exp_Atag;
with Exp_Ch2; use Exp_Ch2;
with Exp_Ch3; use Exp_Ch3;
with Exp_Ch6; use Exp_Ch6;
with Exp_Ch9; use Exp_Ch9;
with Exp_Dist; use Exp_Dist;
with Exp_Imgv; use Exp_Imgv;
with Exp_Pakd; use Exp_Pakd;
with Exp_Strm; use Exp_Strm;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Exp_VFpt; use Exp_VFpt;
with Fname; use Fname;
with Freeze; use Freeze;
with Gnatvsn; use Gnatvsn;
with Itypes; use Itypes;
with Lib; use Lib;
with Namet; use Namet;
with Nmake; use Nmake;
with Nlists; use Nlists;
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_Ch7; use Sem_Ch7;
with Sem_Ch8; use Sem_Ch8;
with Sem_Eval; use Sem_Eval;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stand; use Stand;
with Stringt; use Stringt;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Ttypes; use Ttypes;
with Uintp; use Uintp;
with Uname; use Uname;
with Validsw; use Validsw;
package body Exp_Attr is
-----------------------
-- Local Subprograms --
-----------------------
function Build_Array_VS_Func
(A_Type : Entity_Id;
Nod : Node_Id) return Entity_Id;
-- Build function to test Valid_Scalars for array type A_Type. Nod is the
-- Valid_Scalars attribute node, used to insert the function body, and the
-- value returned is the entity of the constructed function body. We do not
-- bother to generate a separate spec for this subprogram.
procedure Compile_Stream_Body_In_Scope
(N : Node_Id;
Decl : Node_Id;
Arr : Entity_Id;
Check : Boolean);
-- The body for a stream subprogram may be generated outside of the scope
-- of the type. If the type is fully private, it may depend on the full
-- view of other types (e.g. indexes) that are currently private as well.
-- We install the declarations of the package in which the type is declared
-- before compiling the body in what is its proper environment. The Check
-- parameter indicates if checks are to be suppressed for the stream body.
-- We suppress checks for array/record reads, since the rule is that these
-- are like assignments, out of range values due to uninitialized storage,
-- or other invalid values do NOT cause a Constraint_Error to be raised.
procedure Expand_Access_To_Protected_Op
(N : Node_Id;
Pref : Node_Id;
Typ : Entity_Id);
-- An attribute reference to a protected subprogram is transformed into
-- a pair of pointers: one to the object, and one to the operations.
-- This expansion is performed for 'Access and for 'Unrestricted_Access.
procedure Expand_Fpt_Attribute
(N : Node_Id;
Pkg : RE_Id;
Nam : Name_Id;
Args : List_Id);
-- This procedure expands a call to a floating-point attribute function.
-- N is the attribute reference node, and Args is a list of arguments to
-- be passed to the function call. Pkg identifies the package containing
-- the appropriate instantiation of System.Fat_Gen. Float arguments in Args
-- have already been converted to the floating-point type for which Pkg was
-- instantiated. The Nam argument is the relevant attribute processing
-- routine to be called. This is the same as the attribute name, except in
-- the Unaligned_Valid case.
procedure Expand_Fpt_Attribute_R (N : Node_Id);
-- This procedure expands a call to a floating-point attribute function
-- that takes a single floating-point argument. The function to be called
-- is always the same as the attribute name.
procedure Expand_Fpt_Attribute_RI (N : Node_Id);
-- This procedure expands a call to a floating-point attribute function
-- that takes one floating-point argument and one integer argument. The
-- function to be called is always the same as the attribute name.
procedure Expand_Fpt_Attribute_RR (N : Node_Id);
-- This procedure expands a call to a floating-point attribute function
-- that takes two floating-point arguments. The function to be called
-- is always the same as the attribute name.
procedure Expand_Pred_Succ (N : Node_Id);
-- Handles expansion of Pred or Succ attributes for case of non-real
-- operand with overflow checking required.
procedure Expand_Update_Attribute (N : Node_Id);
-- Handle the expansion of attribute Update
function Get_Index_Subtype (N : Node_Id) return Entity_Id;
-- Used for Last, Last, and Length, when the prefix is an array type.
-- Obtains the corresponding index subtype.
procedure Find_Fat_Info
(T : Entity_Id;
Fat_Type : out Entity_Id;
Fat_Pkg : out RE_Id);
-- Given a floating-point type T, identifies the package containing the
-- attributes for this type (returned in Fat_Pkg), and the corresponding
-- type for which this package was instantiated from Fat_Gen. Error if T
-- is not a floating-point type.
function Find_Stream_Subprogram
(Typ : Entity_Id;
Nam : TSS_Name_Type) return Entity_Id;
-- Returns the stream-oriented subprogram attribute for Typ. For tagged
-- types, the corresponding primitive operation is looked up, else the
-- appropriate TSS from the type itself, or from its closest ancestor
-- defining it, is returned. In both cases, inheritance of representation
-- aspects is thus taken into account.
function Full_Base (T : Entity_Id) return Entity_Id;
-- The stream functions need to examine the underlying representation of
-- composite types. In some cases T may be non-private but its base type
-- is, in which case the function returns the corresponding full view.
function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id;
-- Given a type, find a corresponding stream convert pragma that applies to
-- the implementation base type of this type (Typ). If found, return the
-- pragma node, otherwise return Empty if no pragma is found.
function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean;
-- Utility for array attributes, returns true on packed constrained
-- arrays, and on access to same.
function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean;
-- Returns true iff the given node refers to an attribute call that
-- can be expanded directly by the back end and does not need front end
-- expansion. Typically used for rounding and truncation attributes that
-- appear directly inside a conversion to integer.
-------------------------
-- Build_Array_VS_Func --
-------------------------
function Build_Array_VS_Func
(A_Type : Entity_Id;
Nod : Node_Id) return Entity_Id
is
Loc : constant Source_Ptr := Sloc (Nod);
Comp_Type : constant Entity_Id := Component_Type (A_Type);
Body_Stmts : List_Id;
Index_List : List_Id;
Func_Id : Entity_Id;
Formals : List_Id;
function Test_Component return List_Id;
-- Create one statement to test validity of one component designated by
-- a full set of indexes. Returns statement list containing test.
function Test_One_Dimension (N : Int) return List_Id;
-- Create loop to test one dimension of the array. The single statement
-- in the loop body tests the inner dimensions if any, or else the
-- single component. Note that this procedure is called recursively,
-- with N being the dimension to be initialized. A call with N greater
-- than the number of dimensions simply generates the component test,
-- terminating the recursion. Returns statement list containing tests.
--------------------
-- Test_Component --
--------------------
function Test_Component return List_Id is
Comp : Node_Id;
Anam : Name_Id;
begin
Comp :=
Make_Indexed_Component (Loc,
Prefix => Make_Identifier (Loc, Name_uA),
Expressions => Index_List);
if Is_Scalar_Type (Comp_Type) then
Anam := Name_Valid;
else
Anam := Name_Valid_Scalars;
end if;
return New_List (
Make_If_Statement (Loc,
Condition =>
Make_Op_Not (Loc,
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Anam,
Prefix => Comp)),
Then_Statements => New_List (
Make_Simple_Return_Statement (Loc,
Expression => New_Occurrence_Of (Standard_False, Loc)))));
end Test_Component;
------------------------
-- Test_One_Dimension --
------------------------
function Test_One_Dimension (N : Int) return List_Id is
Index : Entity_Id;
begin
-- If all dimensions dealt with, we simply test the component
if N > Number_Dimensions (A_Type) then
return Test_Component;
-- Here we generate the required loop
else
Index :=
Make_Defining_Identifier (Loc, New_External_Name ('J', N));
Append (New_Reference_To (Index, Loc), Index_List);
return New_List (
Make_Implicit_Loop_Statement (Nod,
Identifier => Empty,
Iteration_Scheme =>
Make_Iteration_Scheme (Loc,
Loop_Parameter_Specification =>
Make_Loop_Parameter_Specification (Loc,
Defining_Identifier => Index,
Discrete_Subtype_Definition =>
Make_Attribute_Reference (Loc,
Prefix => Make_Identifier (Loc, Name_uA),
Attribute_Name => Name_Range,
Expressions => New_List (
Make_Integer_Literal (Loc, N))))),
Statements => Test_One_Dimension (N + 1)),
Make_Simple_Return_Statement (Loc,
Expression => New_Occurrence_Of (Standard_True, Loc)));
end if;
end Test_One_Dimension;
-- Start of processing for Build_Array_VS_Func
begin
Index_List := New_List;
Func_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('V'));
Body_Stmts := Test_One_Dimension (1);
-- Parameter is always (A : A_Typ)
Formals := New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => Make_Defining_Identifier (Loc, Name_uA),
In_Present => True,
Out_Present => False,
Parameter_Type => New_Reference_To (A_Type, Loc)));
-- Build body
Set_Ekind (Func_Id, E_Function);
Set_Is_Internal (Func_Id);
Insert_Action (Nod,
Make_Subprogram_Body (Loc,
Specification =>
Make_Function_Specification (Loc,
Defining_Unit_Name => Func_Id,
Parameter_Specifications => Formals,
Result_Definition =>
New_Occurrence_Of (Standard_Boolean, Loc)),
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Body_Stmts)));
if not Debug_Generated_Code then
Set_Debug_Info_Off (Func_Id);
end if;
return Func_Id;
end Build_Array_VS_Func;
----------------------------------
-- Compile_Stream_Body_In_Scope --
----------------------------------
procedure Compile_Stream_Body_In_Scope
(N : Node_Id;
Decl : Node_Id;
Arr : Entity_Id;
Check : Boolean)
is
Installed : Boolean := False;
Scop : constant Entity_Id := Scope (Arr);
Curr : constant Entity_Id := Current_Scope;
begin
if Is_Hidden (Arr)
and then not In_Open_Scopes (Scop)
and then Ekind (Scop) = E_Package
then
Push_Scope (Scop);
Install_Visible_Declarations (Scop);
Install_Private_Declarations (Scop);
Installed := True;
-- The entities in the package are now visible, but the generated
-- stream entity must appear in the current scope (usually an
-- enclosing stream function) so that itypes all have their proper
-- scopes.
Push_Scope (Curr);
end if;
if Check then
Insert_Action (N, Decl);
else
Insert_Action (N, Decl, Suppress => All_Checks);
end if;
if Installed then
-- Remove extra copy of current scope, and package itself
Pop_Scope;
End_Package_Scope (Scop);
end if;
end Compile_Stream_Body_In_Scope;
-----------------------------------
-- Expand_Access_To_Protected_Op --
-----------------------------------
procedure Expand_Access_To_Protected_Op
(N : Node_Id;
Pref : Node_Id;
Typ : Entity_Id)
is
-- The value of the attribute_reference is a record containing two
-- fields: an access to the protected object, and an access to the
-- subprogram itself. The prefix is a selected component.
Loc : constant Source_Ptr := Sloc (N);
Agg : Node_Id;
Btyp : constant Entity_Id := Base_Type (Typ);
Sub : Entity_Id;
Sub_Ref : Node_Id;
E_T : constant Entity_Id := Equivalent_Type (Btyp);
Acc : constant Entity_Id :=
Etype (Next_Component (First_Component (E_T)));
Obj_Ref : Node_Id;
Curr : Entity_Id;
function May_Be_External_Call return Boolean;
-- If the 'Access is to a local operation, but appears in a context
-- where it may lead to a call from outside the object, we must treat
-- this as an external call. Clearly we cannot tell without full
-- flow analysis, and a subsequent call that uses this 'Access may
-- lead to a bounded error (trying to seize locks twice, e.g.). For
-- now we treat 'Access as a potential external call if it is an actual
-- in a call to an outside subprogram.
--------------------------
-- May_Be_External_Call --
--------------------------
function May_Be_External_Call return Boolean is
Subp : Entity_Id;
Par : Node_Id := Parent (N);
begin
-- Account for the case where the Access attribute is part of a
-- named parameter association.
if Nkind (Par) = N_Parameter_Association then
Par := Parent (Par);
end if;
if Nkind (Par) in N_Subprogram_Call
and then Is_Entity_Name (Name (Par))
then
Subp := Entity (Name (Par));
return not In_Open_Scopes (Scope (Subp));
else
return False;
end if;
end May_Be_External_Call;
-- Start of processing for Expand_Access_To_Protected_Op
begin
-- Within the body of the protected type, the prefix designates a local
-- operation, and the object is the first parameter of the corresponding
-- protected body of the current enclosing operation.
if Is_Entity_Name (Pref) then
if May_Be_External_Call then
Sub :=
New_Occurrence_Of (External_Subprogram (Entity (Pref)), Loc);
else
Sub :=
New_Occurrence_Of
(Protected_Body_Subprogram (Entity (Pref)), Loc);
end if;
-- Don't traverse the scopes when the attribute occurs within an init
-- proc, because we directly use the _init formal of the init proc in
-- that case.
Curr := Current_Scope;
if not Is_Init_Proc (Curr) then
pragma Assert (In_Open_Scopes (Scope (Entity (Pref))));
while Scope (Curr) /= Scope (Entity (Pref)) loop
Curr := Scope (Curr);
end loop;
end if;
-- In case of protected entries the first formal of its Protected_
-- Body_Subprogram is the address of the object.
if Ekind (Curr) = E_Entry then
Obj_Ref :=
New_Occurrence_Of
(First_Formal
(Protected_Body_Subprogram (Curr)), Loc);
-- If the current scope is an init proc, then use the address of the
-- _init formal as the object reference.
elsif Is_Init_Proc (Curr) then
Obj_Ref :=
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (First_Formal (Curr), Loc),
Attribute_Name => Name_Address);
-- In case of protected subprograms the first formal of its
-- Protected_Body_Subprogram is the object and we get its address.
else
Obj_Ref :=
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of
(First_Formal
(Protected_Body_Subprogram (Curr)), Loc),
Attribute_Name => Name_Address);
end if;
-- Case where the prefix is not an entity name. Find the
-- version of the protected operation to be called from
-- outside the protected object.
else
Sub :=
New_Occurrence_Of
(External_Subprogram
(Entity (Selector_Name (Pref))), Loc);
Obj_Ref :=
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Prefix (Pref)),
Attribute_Name => Name_Address);
end if;
Sub_Ref :=
Make_Attribute_Reference (Loc,
Prefix => Sub,
Attribute_Name => Name_Access);
-- We set the type of the access reference to the already generated
-- access_to_subprogram type, and declare the reference analyzed, to
-- prevent further expansion when the enclosing aggregate is analyzed.
Set_Etype (Sub_Ref, Acc);
Set_Analyzed (Sub_Ref);
Agg :=
Make_Aggregate (Loc,
Expressions => New_List (Obj_Ref, Sub_Ref));
-- Sub_Ref has been marked as analyzed, but we still need to make sure
-- Sub is correctly frozen.
Freeze_Before (N, Entity (Sub));
Rewrite (N, Agg);
Analyze_And_Resolve (N, E_T);
-- For subsequent analysis, the node must retain its type. The backend
-- will replace it with the equivalent type where needed.
Set_Etype (N, Typ);
end Expand_Access_To_Protected_Op;
--------------------------
-- Expand_Fpt_Attribute --
--------------------------
procedure Expand_Fpt_Attribute
(N : Node_Id;
Pkg : RE_Id;
Nam : Name_Id;
Args : List_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Fnm : Node_Id;
begin
-- The function name is the selected component Attr_xxx.yyy where
-- Attr_xxx is the package name, and yyy is the argument Nam.
-- Note: it would be more usual to have separate RE entries for each
-- of the entities in the Fat packages, but first they have identical
-- names (so we would have to have lots of renaming declarations to
-- meet the normal RE rule of separate names for all runtime entities),
-- and second there would be an awful lot of them!
Fnm :=
Make_Selected_Component (Loc,
Prefix => New_Reference_To (RTE (Pkg), Loc),
Selector_Name => Make_Identifier (Loc, Nam));
-- The generated call is given the provided set of parameters, and then
-- wrapped in a conversion which converts the result to the target type
-- We use the base type as the target because a range check may be
-- required.
Rewrite (N,
Unchecked_Convert_To (Base_Type (Etype (N)),
Make_Function_Call (Loc,
Name => Fnm,
Parameter_Associations => Args)));
Analyze_And_Resolve (N, Typ);
end Expand_Fpt_Attribute;
----------------------------
-- Expand_Fpt_Attribute_R --
----------------------------
-- The single argument is converted to its root type to call the
-- appropriate runtime function, with the actual call being built
-- by Expand_Fpt_Attribute
procedure Expand_Fpt_Attribute_R (N : Node_Id) is
E1 : constant Node_Id := First (Expressions (N));
Ftp : Entity_Id;
Pkg : RE_Id;
begin
Find_Fat_Info (Etype (E1), Ftp, Pkg);
Expand_Fpt_Attribute
(N, Pkg, Attribute_Name (N),
New_List (Unchecked_Convert_To (Ftp, Relocate_Node (E1))));
end Expand_Fpt_Attribute_R;
-----------------------------
-- Expand_Fpt_Attribute_RI --
-----------------------------
-- The first argument is converted to its root type and the second
-- argument is converted to standard long long integer to call the
-- appropriate runtime function, with the actual call being built
-- by Expand_Fpt_Attribute
procedure Expand_Fpt_Attribute_RI (N : Node_Id) is
E1 : constant Node_Id := First (Expressions (N));
Ftp : Entity_Id;
Pkg : RE_Id;
E2 : constant Node_Id := Next (E1);
begin
Find_Fat_Info (Etype (E1), Ftp, Pkg);
Expand_Fpt_Attribute
(N, Pkg, Attribute_Name (N),
New_List (
Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
Unchecked_Convert_To (Standard_Integer, Relocate_Node (E2))));
end Expand_Fpt_Attribute_RI;
-----------------------------
-- Expand_Fpt_Attribute_RR --
-----------------------------
-- The two arguments are converted to their root types to call the
-- appropriate runtime function, with the actual call being built
-- by Expand_Fpt_Attribute
procedure Expand_Fpt_Attribute_RR (N : Node_Id) is
E1 : constant Node_Id := First (Expressions (N));
Ftp : Entity_Id;
Pkg : RE_Id;
E2 : constant Node_Id := Next (E1);
begin
Find_Fat_Info (Etype (E1), Ftp, Pkg);
Expand_Fpt_Attribute
(N, Pkg, Attribute_Name (N),
New_List (
Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
Unchecked_Convert_To (Ftp, Relocate_Node (E2))));
end Expand_Fpt_Attribute_RR;
----------------------------------
-- Expand_N_Attribute_Reference --
----------------------------------
procedure Expand_N_Attribute_Reference (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Btyp : constant Entity_Id := Base_Type (Typ);
Pref : constant Node_Id := Prefix (N);
Ptyp : constant Entity_Id := Etype (Pref);
Exprs : constant List_Id := Expressions (N);
Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id);
-- Rewrites a stream attribute for Read, Write or Output with the
-- procedure call. Pname is the entity for the procedure to call.
------------------------------
-- Rewrite_Stream_Proc_Call --
------------------------------
procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id) is
Item : constant Node_Id := Next (First (Exprs));
Formal : constant Entity_Id := Next_Formal (First_Formal (Pname));
Formal_Typ : constant Entity_Id := Etype (Formal);
Is_Written : constant Boolean := (Ekind (Formal) /= E_In_Parameter);
begin
-- The expansion depends on Item, the second actual, which is
-- the object being streamed in or out.
-- If the item is a component of a packed array type, and
-- a conversion is needed on exit, we introduce a temporary to
-- hold the value, because otherwise the packed reference will
-- not be properly expanded.
if Nkind (Item) = N_Indexed_Component
and then Is_Packed (Base_Type (Etype (Prefix (Item))))
and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
and then Is_Written
then
declare
Temp : constant Entity_Id := Make_Temporary (Loc, 'V');
Decl : Node_Id;
Assn : Node_Id;
begin
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition =>
New_Occurrence_Of (Formal_Typ, Loc));
Set_Etype (Temp, Formal_Typ);
Assn :=
Make_Assignment_Statement (Loc,
Name => New_Copy_Tree (Item),
Expression =>
Unchecked_Convert_To
(Etype (Item), New_Occurrence_Of (Temp, Loc)));
Rewrite (Item, New_Occurrence_Of (Temp, Loc));
Insert_Actions (N,
New_List (
Decl,
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Pname, Loc),
Parameter_Associations => Exprs),
Assn));
Rewrite (N, Make_Null_Statement (Loc));
return;
end;
end if;
-- For the class-wide dispatching cases, and for cases in which
-- the base type of the second argument matches the base type of
-- the corresponding formal parameter (that is to say the stream
-- operation is not inherited), we are all set, and can use the
-- argument unchanged.
-- For all other cases we do an unchecked conversion of the second
-- parameter to the type of the formal of the procedure we are
-- calling. This deals with the private type cases, and with going
-- to the root type as required in elementary type case.
if not Is_Class_Wide_Type (Entity (Pref))
and then not Is_Class_Wide_Type (Etype (Item))
and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
then
Rewrite (Item,
Unchecked_Convert_To (Formal_Typ, Relocate_Node (Item)));
-- For untagged derived types set Assignment_OK, to prevent
-- copies from being created when the unchecked conversion
-- is expanded (which would happen in Remove_Side_Effects
-- if Expand_N_Unchecked_Conversion were allowed to call
-- Force_Evaluation). The copy could violate Ada semantics
-- in cases such as an actual that is an out parameter.
-- Note that this approach is also used in exp_ch7 for calls
-- to controlled type operations to prevent problems with
-- actuals wrapped in unchecked conversions.
if Is_Untagged_Derivation (Etype (Expression (Item))) then
Set_Assignment_OK (Item);
end if;
end if;
-- The stream operation to call maybe a renaming created by
-- an attribute definition clause, and may not be frozen yet.
-- Ensure that it has the necessary extra formals.
if not Is_Frozen (Pname) then
Create_Extra_Formals (Pname);
end if;
-- And now rewrite the call
Rewrite (N,
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Pname, Loc),
Parameter_Associations => Exprs));
Analyze (N);
end Rewrite_Stream_Proc_Call;
-- Start of processing for Expand_N_Attribute_Reference
begin
-- Do required validity checking, if enabled. Do not apply check to
-- output parameters of an Asm instruction, since the value of this
-- is not set till after the attribute has been elaborated, and do
-- not apply the check to the arguments of a 'Read or 'Input attribute
-- reference since the scalar argument is an OUT scalar.
if Validity_Checks_On and then Validity_Check_Operands
and then Id /= Attribute_Asm_Output
and then Id /= Attribute_Read
and then Id /= Attribute_Input
then
declare
Expr : Node_Id;
begin
Expr := First (Expressions (N));
while Present (Expr) loop
Ensure_Valid (Expr);
Next (Expr);
end loop;
end;
end if;
-- Ada 2005 (AI-318-02): If attribute prefix 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. 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.
if Ada_Version >= Ada_2005
and then Is_Build_In_Place_Function_Call (Pref)
then
Make_Build_In_Place_Call_In_Anonymous_Context (Pref);
end if;
-- If prefix is a protected type name, this is a reference to the
-- current instance of the type. For a component definition, nothing
-- to do (expansion will occur in the init proc). In other contexts,
-- rewrite into reference to current instance.
if Is_Protected_Self_Reference (Pref)
and then not
(Nkind_In (Parent (N), N_Index_Or_Discriminant_Constraint,
N_Discriminant_Association)
and then Nkind (Parent (Parent (Parent (Parent (N))))) =
N_Component_Definition)
-- No action needed for these attributes since the current instance
-- will be rewritten to be the name of the _object parameter
-- associated with the enclosing protected subprogram (see below).
and then Id /= Attribute_Access
and then Id /= Attribute_Unchecked_Access
and then Id /= Attribute_Unrestricted_Access
then
Rewrite (Pref, Concurrent_Ref (Pref));
Analyze (Pref);
end if;
-- Remaining processing depends on specific attribute
-- Note: individual sections of the following case statement are
-- allowed to assume there is no code after the case statement, and
-- are legitimately allowed to execute return statements if they have
-- nothing more to do.
case Id is
-- Attributes related to Ada 2012 iterators (placeholder ???)
when Attribute_Constant_Indexing |
Attribute_Default_Iterator |
Attribute_Implicit_Dereference |
Attribute_Iterator_Element |
Attribute_Variable_Indexing =>
null;
-- Internal attributes used to deal with Ada 2012 delayed aspects. These
-- were already rejected by the parser. Thus they shouldn't appear here.
when Internal_Attribute_Id =>
raise Program_Error;
------------
-- Access --
------------
when Attribute_Access |
Attribute_Unchecked_Access |
Attribute_Unrestricted_Access =>
Access_Cases : declare
Ref_Object : constant Node_Id := Get_Referenced_Object (Pref);
Btyp_DDT : Entity_Id;
function Enclosing_Object (N : Node_Id) return Node_Id;
-- If N denotes a compound name (selected component, indexed
-- component, or slice), returns the name of the outermost such
-- enclosing object. Otherwise returns N. If the object is a
-- renaming, then the renamed object is returned.
----------------------
-- Enclosing_Object --
----------------------
function Enclosing_Object (N : Node_Id) return Node_Id is
Obj_Name : Node_Id;
begin
Obj_Name := N;
while Nkind_In (Obj_Name, N_Selected_Component,
N_Indexed_Component,
N_Slice)
loop
Obj_Name := Prefix (Obj_Name);
end loop;
return Get_Referenced_Object (Obj_Name);
end Enclosing_Object;
-- Local declarations
Enc_Object : constant Node_Id := Enclosing_Object (Ref_Object);
-- Start of processing for Access_Cases
begin
Btyp_DDT := Designated_Type (Btyp);
-- Handle designated types that come from the limited view
if Ekind (Btyp_DDT) = E_Incomplete_Type
and then From_With_Type (Btyp_DDT)
and then Present (Non_Limited_View (Btyp_DDT))
then
Btyp_DDT := Non_Limited_View (Btyp_DDT);
elsif Is_Class_Wide_Type (Btyp_DDT)
and then Ekind (Etype (Btyp_DDT)) = E_Incomplete_Type
and then From_With_Type (Etype (Btyp_DDT))
and then Present (Non_Limited_View (Etype (Btyp_DDT)))
and then Present (Class_Wide_Type
(Non_Limited_View (Etype (Btyp_DDT))))
then
Btyp_DDT :=
Class_Wide_Type (Non_Limited_View (Etype (Btyp_DDT)));
end if;
-- In order to improve the text of error messages, the designated
-- type of access-to-subprogram itypes is set by the semantics as
-- the associated subprogram entity (see sem_attr). Now we replace
-- such node with the proper E_Subprogram_Type itype.
if Id = Attribute_Unrestricted_Access
and then Is_Subprogram (Directly_Designated_Type (Typ))
then
-- The following conditions ensure that this special management
-- is done only for "Address!(Prim'Unrestricted_Access)" nodes.
-- At this stage other cases in which the designated type is
-- still a subprogram (instead of an E_Subprogram_Type) are
-- wrong because the semantics must have overridden the type of
-- the node with the type imposed by the context.
if Nkind (Parent (N)) = N_Unchecked_Type_Conversion
and then Etype (Parent (N)) = RTE (RE_Prim_Ptr)
then
Set_Etype (N, RTE (RE_Prim_Ptr));
else
declare
Subp : constant Entity_Id :=
Directly_Designated_Type (Typ);
Etyp : Entity_Id;
Extra : Entity_Id := Empty;
New_Formal : Entity_Id;
Old_Formal : Entity_Id := First_Formal (Subp);
Subp_Typ : Entity_Id;
begin
Subp_Typ := Create_Itype (E_Subprogram_Type, N);
Set_Etype (Subp_Typ, Etype (Subp));
Set_Returns_By_Ref (Subp_Typ, Returns_By_Ref (Subp));
if Present (Old_Formal) then
New_Formal := New_Copy (Old_Formal);
Set_First_Entity (Subp_Typ, New_Formal);
loop
Set_Scope (New_Formal, Subp_Typ);
Etyp := Etype (New_Formal);
-- Handle itypes. There is no need to duplicate
-- here the itypes associated with record types
-- (i.e the implicit full view of private types).
if Is_Itype (Etyp)
and then Ekind (Base_Type (Etyp)) /= E_Record_Type
then
Extra := New_Copy (Etyp);
Set_Parent (Extra, New_Formal);
Set_Etype (New_Formal, Extra);
Set_Scope (Extra, Subp_Typ);
end if;
Extra := New_Formal;
Next_Formal (Old_Formal);
exit when No (Old_Formal);
Set_Next_Entity (New_Formal,
New_Copy (Old_Formal));
Next_Entity (New_Formal);
end loop;
Set_Next_Entity (New_Formal, Empty);
Set_Last_Entity (Subp_Typ, Extra);
end if;
-- Now that the explicit formals have been duplicated,
-- any extra formals needed by the subprogram must be
-- created.
if Present (Extra) then
Set_Extra_Formal (Extra, Empty);
end if;
Create_Extra_Formals (Subp_Typ);
Set_Directly_Designated_Type (Typ, Subp_Typ);
end;
end if;
end if;
if Is_Access_Protected_Subprogram_Type (Btyp) then
Expand_Access_To_Protected_Op (N, Pref, Typ);
-- If prefix is a type name, this is a reference to the current
-- instance of the type, within its initialization procedure.
elsif Is_Entity_Name (Pref)
and then Is_Type (Entity (Pref))
then
declare
Par : Node_Id;
Formal : Entity_Id;
begin
-- If the current instance name denotes a task type, then
-- the access attribute is rewritten to be the name of the
-- "_task" parameter associated with the task type's task
-- procedure. An unchecked conversion is applied to ensure
-- a type match in cases of expander-generated calls (e.g.
-- init procs).
if Is_Task_Type (Entity (Pref)) then
Formal :=
First_Entity (Get_Task_Body_Procedure (Entity (Pref)));
while Present (Formal) loop
exit when Chars (Formal) = Name_uTask;
Next_Entity (Formal);
end loop;
pragma Assert (Present (Formal));
Rewrite (N,
Unchecked_Convert_To (Typ,
New_Occurrence_Of (Formal, Loc)));
Set_Etype (N, Typ);
elsif Is_Protected_Type (Entity (Pref)) then
-- No action needed for current instance located in a
-- component definition (expansion will occur in the
-- init proc)
if Is_Protected_Type (Current_Scope) then
null;
-- If the current instance reference is located in a
-- protected subprogram or entry then rewrite the access
-- attribute to be the name of the "_object" parameter.
-- An unchecked conversion is applied to ensure a type
-- match in cases of expander-generated calls (e.g. init
-- procs).
else
Formal :=
First_Entity
(Protected_Body_Subprogram (Current_Scope));
Rewrite (N,
Unchecked_Convert_To (Typ,
New_Occurrence_Of (Formal, Loc)));
Set_Etype (N, Typ);
end if;
-- The expression must appear in a default expression,
-- (which in the initialization procedure is the right-hand
-- side of an assignment), and not in a discriminant
-- constraint.
else
Par := Parent (N);
while Present (Par) loop
exit when Nkind (Par) = N_Assignment_Statement;
if Nkind (Par) = N_Component_Declaration then
return;
end if;
Par := Parent (Par);
end loop;
if Present (Par) then
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => Make_Identifier (Loc, Name_uInit),
Attribute_Name => Attribute_Name (N)));
Analyze_And_Resolve (N, Typ);
end if;
end if;
end;
-- If the prefix of an Access attribute is a dereference of an
-- access parameter (or a renaming of such a dereference, or a
-- subcomponent of such a dereference) and the context is a
-- general access type (including the type of an object or
-- component with an access_definition, but not the anonymous
-- type of an access parameter or access discriminant), then
-- apply an accessibility check to the access parameter. We used
-- to rewrite the access parameter as a type conversion, but that
-- could only be done if the immediate prefix of the Access
-- attribute was the dereference, and didn't handle cases where
-- the attribute is applied to a subcomponent of the dereference,
-- since there's generally no available, appropriate access type
-- to convert to in that case. The attribute is passed as the
-- point to insert the check, because the access parameter may
-- come from a renaming, possibly in a different scope, and the
-- check must be associated with the attribute itself.
elsif Id = Attribute_Access
and then Nkind (Enc_Object) = N_Explicit_Dereference
and then Is_Entity_Name (Prefix (Enc_Object))
and then (Ekind (Btyp) = E_General_Access_Type
or else Is_Local_Anonymous_Access (Btyp))
and then Ekind (Entity (Prefix (Enc_Object))) in Formal_Kind
and then Ekind (Etype (Entity (Prefix (Enc_Object))))
= E_Anonymous_Access_Type
and then Present (Extra_Accessibility
(Entity (Prefix (Enc_Object))))
then
Apply_Accessibility_Check (Prefix (Enc_Object), Typ, N);
-- Ada 2005 (AI-251): If the designated type is an interface we
-- add an implicit conversion to force the displacement of the
-- pointer to reference the secondary dispatch table.
elsif Is_Interface (Btyp_DDT)
and then (Comes_From_Source (N)
or else Comes_From_Source (Ref_Object)
or else (Nkind (Ref_Object) in N_Has_Chars
and then Chars (Ref_Object) = Name_uInit))
then
if Nkind (Ref_Object) /= N_Explicit_Dereference then
-- No implicit conversion required if types match, or if
-- the prefix is the class_wide_type of the interface. In
-- either case passing an object of the interface type has
-- already set the pointer correctly.
if Btyp_DDT = Etype (Ref_Object)
or else (Is_Class_Wide_Type (Etype (Ref_Object))
and then
Class_Wide_Type (Btyp_DDT) = Etype (Ref_Object))
then
null;
else
Rewrite (Prefix (N),
Convert_To (Btyp_DDT,
New_Copy_Tree (Prefix (N))));
Analyze_And_Resolve (Prefix (N), Btyp_DDT);
end if;
-- When the object is an explicit dereference, convert the
-- dereference's prefix.
else
declare
Obj_DDT : constant Entity_Id :=
Base_Type
(Directly_Designated_Type
(Etype (Prefix (Ref_Object))));
begin
-- No implicit conversion required if designated types
-- match, or if we have an unrestricted access.
if Obj_DDT /= Btyp_DDT
and then Id /= Attribute_Unrestricted_Access
and then not (Is_Class_Wide_Type (Obj_DDT)
and then Etype (Obj_DDT) = Btyp_DDT)
then
Rewrite (N,
Convert_To (Typ,
New_Copy_Tree (Prefix (Ref_Object))));
Analyze_And_Resolve (N, Typ);
end if;
end;
end if;
end if;
end Access_Cases;
--------------
-- Adjacent --
--------------
-- Transforms 'Adjacent into a call to the floating-point attribute
-- function Adjacent in Fat_xxx (where xxx is the root type)
when Attribute_Adjacent =>
Expand_Fpt_Attribute_RR (N);
-------------
-- Address --
-------------
when Attribute_Address => Address : declare
Task_Proc : Entity_Id;
begin
-- If the prefix is a task or a task type, the useful address is that
-- of the procedure for the task body, i.e. the actual program unit.
-- We replace the original entity with that of the procedure.
if Is_Entity_Name (Pref)
and then Is_Task_Type (Entity (Pref))
then
Task_Proc := Next_Entity (Root_Type (Ptyp));
while Present (Task_Proc) loop
exit when Ekind (Task_Proc) = E_Procedure
and then Etype (First_Formal (Task_Proc)) =
Corresponding_Record_Type (Ptyp);
Next_Entity (Task_Proc);
end loop;
if Present (Task_Proc) then
Set_Entity (Pref, Task_Proc);
Set_Etype (Pref, Etype (Task_Proc));
end if;
-- Similarly, the address of a protected operation is the address
-- of the corresponding protected body, regardless of the protected
-- object from which it is selected.
elsif Nkind (Pref) = N_Selected_Component
and then Is_Subprogram (Entity (Selector_Name (Pref)))
and then Is_Protected_Type (Scope (Entity (Selector_Name (Pref))))
then
Rewrite (Pref,
New_Occurrence_Of (
External_Subprogram (Entity (Selector_Name (Pref))), Loc));
elsif Nkind (Pref) = N_Explicit_Dereference
and then Ekind (Ptyp) = E_Subprogram_Type
and then Convention (Ptyp) = Convention_Protected
then
-- The prefix is be a dereference of an access_to_protected_
-- subprogram. The desired address is the second component of
-- the record that represents the access.
declare
Addr : constant Entity_Id := Etype (N);
Ptr : constant Node_Id := Prefix (Pref);
T : constant Entity_Id :=
Equivalent_Type (Base_Type (Etype (Ptr)));
begin
Rewrite (N,
Unchecked_Convert_To (Addr,
Make_Selected_Component (Loc,
Prefix => Unchecked_Convert_To (T, Ptr),
Selector_Name => New_Occurrence_Of (
Next_Entity (First_Entity (T)), Loc))));
Analyze_And_Resolve (N, Addr);
end;
-- Ada 2005 (AI-251): Class-wide interface objects are always
-- "displaced" to reference the tag associated with the interface
-- type. In order to obtain the real address of such objects we
-- generate a call to a run-time subprogram that returns the base
-- address of the object.
-- This processing is not needed in the VM case, where dispatching
-- issues are taken care of by the virtual machine.
elsif Is_Class_Wide_Type (Ptyp)
and then Is_Interface (Ptyp)
and then Tagged_Type_Expansion
and then not (Nkind (Pref) in N_Has_Entity
and then Is_Subprogram (Entity (Pref)))
then
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Base_Address), Loc),
Parameter_Associations => New_List (
Relocate_Node (N))));
Analyze (N);
return;
end if;
-- Deal with packed array reference, other cases are handled by
-- the back end.
if Involves_Packed_Array_Reference (Pref) then
Expand_Packed_Address_Reference (N);
end if;
end Address;
---------------
-- Alignment --
---------------
when Attribute_Alignment => Alignment : declare
New_Node : Node_Id;
begin
-- For class-wide types, X'Class'Alignment is transformed into a
-- direct reference to the Alignment of the class type, so that the
-- back end does not have to deal with the X'Class'Alignment
-- reference.
if Is_Entity_Name (Pref)
and then Is_Class_Wide_Type (Entity (Pref))
then
Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
return;
-- For x'Alignment applied to an object of a class wide type,
-- transform X'Alignment into a call to the predefined primitive
-- operation _Alignment applied to X.
elsif Is_Class_Wide_Type (Ptyp) then
New_Node :=
Make_Attribute_Reference (Loc,
Prefix => Pref,
Attribute_Name => Name_Tag);
if VM_Target = No_VM then
New_Node := Build_Get_Alignment (Loc, New_Node);
else
New_Node :=
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Get_Alignment), Loc),
Parameter_Associations => New_List (New_Node));
end if;
-- Case where the context is a specific integer type with which
-- the original attribute was compatible. The function has a
-- specific type as well, so to preserve the compatibility we
-- must convert explicitly.
if Typ /= Standard_Integer then
New_Node := Convert_To (Typ, New_Node);
end if;
Rewrite (N, New_Node);
Analyze_And_Resolve (N, Typ);
return;
-- For all other cases, we just have to deal with the case of
-- the fact that the result can be universal.
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end Alignment;
---------------
-- AST_Entry --
---------------
when Attribute_AST_Entry => AST_Entry : declare
Ttyp : Entity_Id;
T_Id : Node_Id;
Eent : Entity_Id;
Entry_Ref : Node_Id;
-- The reference to the entry or entry family
Index : Node_Id;
-- The index expression for an entry family reference, or
-- the Empty if Entry_Ref references a simple entry.
begin
if Nkind (Pref) = N_Indexed_Component then
Entry_Ref := Prefix (Pref);
Index := First (Expressions (Pref));
else
Entry_Ref := Pref;
Index := Empty;
end if;
-- Get expression for Task_Id and the entry entity
if Nkind (Entry_Ref) = N_Selected_Component then
T_Id :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Identity,
Prefix => Prefix (Entry_Ref));
Ttyp := Etype (Prefix (Entry_Ref));
Eent := Entity (Selector_Name (Entry_Ref));
else
T_Id :=
Make_Function_Call (Loc,
Name => New_Occurrence_Of (RTE (RE_Current_Task), Loc));
Eent := Entity (Entry_Ref);
-- We have to find the enclosing task to get the task type
-- There must be one, since we already validated this earlier
Ttyp := Current_Scope;
while not Is_Task_Type (Ttyp) loop
Ttyp := Scope (Ttyp);
end loop;
end if;
-- Now rewrite the attribute with a call to Create_AST_Handler
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Occurrence_Of (RTE (RE_Create_AST_Handler), Loc),
Parameter_Associations => New_List (
T_Id,
Entry_Index_Expression (Loc, Eent, Index, Ttyp))));
Analyze_And_Resolve (N, RTE (RE_AST_Handler));
end AST_Entry;
---------
-- Bit --
---------
-- We compute this if a packed array reference was present, otherwise we
-- leave the computation up to the back end.
when Attribute_Bit =>
if Involves_Packed_Array_Reference (Pref) then
Expand_Packed_Bit_Reference (N);
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
------------------
-- Bit_Position --
------------------
-- We compute this if a component clause was present, otherwise we leave
-- the computation up to the back end, since we don't know what layout
-- will be chosen.
-- Note that the attribute can apply to a naked record component
-- in generated code (i.e. the prefix is an identifier that
-- references the component or discriminant entity).
when Attribute_Bit_Position => Bit_Position : declare
CE : Entity_Id;
begin
if Nkind (Pref) = N_Identifier then
CE := Entity (Pref);
else
CE := Entity (Selector_Name (Pref));
end if;
if Known_Static_Component_Bit_Offset (CE) then
Rewrite (N,
Make_Integer_Literal (Loc,
Intval => Component_Bit_Offset (CE)));
Analyze_And_Resolve (N, Typ);
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end Bit_Position;
------------------
-- Body_Version --
------------------
-- A reference to P'Body_Version or P'Version is expanded to
-- Vnn : Unsigned;
-- pragma Import (C, Vnn, "uuuuT");
-- ...
-- Get_Version_String (Vnn)
-- where uuuu is the unit name (dots replaced by double underscore)
-- and T is B for the cases of Body_Version, or Version applied to a
-- subprogram acting as its own spec, and S for Version applied to a
-- subprogram spec or package. This sequence of code references the
-- unsigned constant created in the main program by the binder.
-- A special exception occurs for Standard, where the string returned
-- is a copy of the library string in gnatvsn.ads.
when Attribute_Body_Version | Attribute_Version => Version : declare
E : constant Entity_Id := Make_Temporary (Loc, 'V');
Pent : Entity_Id;
S : String_Id;
begin
-- If not library unit, get to containing library unit
Pent := Entity (Pref);
while Pent /= Standard_Standard
and then Scope (Pent) /= Standard_Standard
and then not Is_Child_Unit (Pent)
loop
Pent := Scope (Pent);
end loop;
-- Special case Standard and Standard.ASCII
if Pent = Standard_Standard or else Pent = Standard_ASCII then
Rewrite (N,
Make_String_Literal (Loc,
Strval => Verbose_Library_Version));
-- All other cases
else
-- Build required string constant
Get_Name_String (Get_Unit_Name (Pent));
Start_String;
for J in 1 .. Name_Len - 2 loop
if Name_Buffer (J) = '.' then
Store_String_Chars ("__");
else
Store_String_Char (Get_Char_Code (Name_Buffer (J)));
end if;
end loop;
-- Case of subprogram acting as its own spec, always use body
if Nkind (Declaration_Node (Pent)) in N_Subprogram_Specification
and then Nkind (Parent (Declaration_Node (Pent))) =
N_Subprogram_Body
and then Acts_As_Spec (Parent (Declaration_Node (Pent)))
then
Store_String_Chars ("B");
-- Case of no body present, always use spec
elsif not Unit_Requires_Body (Pent) then
Store_String_Chars ("S");
-- Otherwise use B for Body_Version, S for spec
elsif Id = Attribute_Body_Version then
Store_String_Chars ("B");
else
Store_String_Chars ("S");
end if;
S := End_String;
Lib.Version_Referenced (S);
-- Insert the object declaration
Insert_Actions (N, New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => E,
Object_Definition =>
New_Occurrence_Of (RTE (RE_Unsigned), Loc))));
-- Set entity as imported with correct external name
Set_Is_Imported (E);
Set_Interface_Name (E, Make_String_Literal (Loc, S));
-- Set entity as internal to ensure proper Sprint output of its
-- implicit importation.
Set_Is_Internal (E);
-- And now rewrite original reference
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Get_Version_String), Loc),
Parameter_Associations => New_List (
New_Occurrence_Of (E, Loc))));
end if;
Analyze_And_Resolve (N, RTE (RE_Version_String));
end Version;
-------------
-- Ceiling --
-------------
-- Transforms 'Ceiling into a call to the floating-point attribute
-- function Ceiling in Fat_xxx (where xxx is the root type)
when Attribute_Ceiling =>
Expand_Fpt_Attribute_R (N);
--------------
-- Callable --
--------------
-- Transforms 'Callable attribute into a call to the Callable function
when Attribute_Callable => Callable :
begin
-- We have an object of a task interface class-wide type as a prefix
-- to Callable. Generate:
-- callable (Task_Id (Pref._disp_get_task_id));
if Ada_Version >= Ada_2005
and then Ekind (Ptyp) = E_Class_Wide_Type
and then Is_Interface (Ptyp)
and then Is_Task_Interface (Ptyp)
then
Rewrite (N,
Make_Function_Call (Loc,
Name =>
New_Reference_To (RTE (RE_Callable), Loc),
Parameter_Associations => New_List (
Make_Unchecked_Type_Conversion (Loc,
Subtype_Mark =>
New_Reference_To (RTE (RO_ST_Task_Id), Loc),
Expression =>
Make_Selected_Component (Loc,
Prefix =>
New_Copy_Tree (Pref),
Selector_Name =>
Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
else
Rewrite (N,
Build_Call_With_Task (Pref, RTE (RE_Callable)));
end if;
Analyze_And_Resolve (N, Standard_Boolean);
end Callable;
------------
-- Caller --
------------
-- Transforms 'Caller attribute into a call to either the
-- Task_Entry_Caller or the Protected_Entry_Caller function.
when Attribute_Caller => Caller : declare
Id_Kind : constant Entity_Id := RTE (RO_AT_Task_Id);
Ent : constant Entity_Id := Entity (Pref);
Conctype : constant Entity_Id := Scope (Ent);
Nest_Depth : Integer := 0;
Name : Node_Id;
S : Entity_Id;
begin
-- Protected case
if Is_Protected_Type (Conctype) then
case Corresponding_Runtime_Package (Conctype) is
when System_Tasking_Protected_Objects_Entries =>
Name :=
New_Reference_To
(RTE (RE_Protected_Entry_Caller), Loc);
when System_Tasking_Protected_Objects_Single_Entry =>
Name :=
New_Reference_To
(RTE (RE_Protected_Single_Entry_Caller), Loc);
when others =>
raise Program_Error;
end case;
Rewrite (N,
Unchecked_Convert_To (Id_Kind,
Make_Function_Call (Loc,
Name => Name,
Parameter_Associations => New_List (
New_Reference_To
(Find_Protection_Object (Current_Scope), Loc)))));
-- Task case
else
-- Determine the nesting depth of the E'Caller attribute, that
-- is, how many accept statements are nested within the accept
-- statement for E at the point of E'Caller. The runtime uses
-- this depth to find the specified entry call.
for J in reverse 0 .. Scope_Stack.Last loop
S := Scope_Stack.Table (J).Entity;
-- We should not reach the scope of the entry, as it should
-- already have been checked in Sem_Attr that this attribute
-- reference is within a matching accept statement.
pragma Assert (S /= Conctype);
if S = Ent then
exit;
elsif Is_Entry (S) then
Nest_Depth := Nest_Depth + 1;
end if;
end loop;
Rewrite (N,
Unchecked_Convert_To (Id_Kind,
Make_Function_Call (Loc,
Name =>
New_Reference_To (RTE (RE_Task_Entry_Caller), Loc),
Parameter_Associations => New_List (
Make_Integer_Literal (Loc,
Intval => Int (Nest_Depth))))));
end if;
Analyze_And_Resolve (N, Id_Kind);
end Caller;
-------------
-- Compose --
-------------
-- Transforms 'Compose into a call to the floating-point attribute
-- function Compose in Fat_xxx (where xxx is the root type)
-- Note: we strictly should have special code here to deal with the
-- case of absurdly negative arguments (less than Integer'First)
-- which will return a (signed) zero value, but it hardly seems
-- worth the effort. Absurdly large positive arguments will raise
-- constraint error which is fine.
when Attribute_Compose =>
Expand_Fpt_Attribute_RI (N);
-----------------
-- Constrained --
-----------------
when Attribute_Constrained => Constrained : declare
Formal_Ent : constant Entity_Id := Param_Entity (Pref);
function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean;
-- Ada 2005 (AI-363): Returns True if the object name Obj denotes a
-- view of an aliased object whose subtype is constrained.
---------------------------------
-- Is_Constrained_Aliased_View --
---------------------------------
function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean is
E : Entity_Id;
begin
if Is_Entity_Name (Obj) then
E := Entity (Obj);
if Present (Renamed_Object (E)) then
return Is_Constrained_Aliased_View (Renamed_Object (E));
else
return Is_Aliased (E) and then Is_Constrained (Etype (E));
end if;
else
return Is_Aliased_View (Obj)
and then
(Is_Constrained (Etype (Obj))
or else
(Nkind (Obj) = N_Explicit_Dereference
and then
not Effectively_Has_Constrained_Partial_View
(Typ => Base_Type (Etype (Obj)),
Scop => Current_Scope)));
end if;
end Is_Constrained_Aliased_View;
-- Start of processing for Constrained
begin
-- Reference to a parameter where the value is passed as an extra
-- actual, corresponding to the extra formal referenced by the
-- Extra_Constrained field of the corresponding formal. If this
-- is an entry in-parameter, it is replaced by a constant renaming
-- for which Extra_Constrained is never created.
if Present (Formal_Ent)
and then Ekind (Formal_Ent) /= E_Constant
and then Present (Extra_Constrained (Formal_Ent))
then
Rewrite (N,
New_Occurrence_Of
(Extra_Constrained (Formal_Ent), Sloc (N)));
-- For variables with a Extra_Constrained field, we use the
-- corresponding entity.
elsif Nkind (Pref) = N_Identifier
and then Ekind (Entity (Pref)) = E_Variable
and then Present (Extra_Constrained (Entity (Pref)))
then
Rewrite (N,
New_Occurrence_Of
(Extra_Constrained (Entity (Pref)), Sloc (N)));
-- For all other entity names, we can tell at compile time
elsif Is_Entity_Name (Pref) then
declare
Ent : constant Entity_Id := Entity (Pref);
Res : Boolean;
begin
-- (RM J.4) obsolescent cases
if Is_Type (Ent) then
-- Private type
if Is_Private_Type (Ent) then
Res := not Has_Discriminants (Ent)
or else Is_Constrained (Ent);
-- It not a private type, must be a generic actual type
-- that corresponded to a private type. We know that this
-- correspondence holds, since otherwise the reference
-- within the generic template would have been illegal.
else
if Is_Composite_Type (Underlying_Type (Ent)) then
Res := Is_Constrained (Ent);
else
Res := True;
end if;
end if;
-- If the prefix is not a variable or is aliased, then
-- definitely true; if it's a formal parameter without an
-- associated extra formal, then treat it as constrained.
-- Ada 2005 (AI-363): An aliased prefix must be known to be
-- constrained in order to set the attribute to True.
elsif not Is_Variable (Pref)
or else Present (Formal_Ent)
or else (Ada_Version < Ada_2005
and then Is_Aliased_View (Pref))
or else (Ada_Version >= Ada_2005
and then Is_Constrained_Aliased_View (Pref))
then
Res := True;
-- Variable case, look at type to see if it is constrained.
-- Note that the one case where this is not accurate (the
-- procedure formal case), has been handled above.
-- We use the Underlying_Type here (and below) in case the
-- type is private without discriminants, but the full type
-- has discriminants. This case is illegal, but we generate it
-- internally for passing to the Extra_Constrained parameter.
else
-- In Ada 2012, test for case of a limited tagged type, in
-- which case the attribute is always required to return
-- True. The underlying type is tested, to make sure we also
-- return True for cases where there is an unconstrained
-- object with an untagged limited partial view which has
-- defaulted discriminants (such objects always produce a
-- False in earlier versions of Ada). (Ada 2012: AI05-0214)
Res := Is_Constrained (Underlying_Type (Etype (Ent)))
or else
(Ada_Version >= Ada_2012
and then Is_Tagged_Type (Underlying_Type (Ptyp))
and then Is_Limited_Type (Ptyp));
end if;
Rewrite (N, New_Reference_To (Boolean_Literals (Res), Loc));
end;
-- Prefix is not an entity name. These are also cases where we can
-- always tell at compile time by looking at the form and type of the
-- prefix. If an explicit dereference of an object with constrained
-- partial view, this is unconstrained (Ada 2005: AI95-0363). If the
-- underlying type is a limited tagged type, then Constrained is
-- required to always return True (Ada 2012: AI05-0214).
else
Rewrite (N,
New_Reference_To (
Boolean_Literals (
not Is_Variable (Pref)
or else
(Nkind (Pref) = N_Explicit_Dereference
and then
not Effectively_Has_Constrained_Partial_View
(Typ => Base_Type (Ptyp),
Scop => Current_Scope))
or else Is_Constrained (Underlying_Type (Ptyp))
or else (Ada_Version >= Ada_2012
and then Is_Tagged_Type (Underlying_Type (Ptyp))
and then Is_Limited_Type (Ptyp))),
Loc));
end if;
Analyze_And_Resolve (N, Standard_Boolean);
end Constrained;
---------------
-- Copy_Sign --
---------------
-- Transforms 'Copy_Sign into a call to the floating-point attribute
-- function Copy_Sign in Fat_xxx (where xxx is the root type)
when Attribute_Copy_Sign =>
Expand_Fpt_Attribute_RR (N);
-----------
-- Count --
-----------
-- Transforms 'Count attribute into a call to the Count function
when Attribute_Count => Count : declare
Call : Node_Id;
Conctyp : Entity_Id;
Entnam : Node_Id;
Entry_Id : Entity_Id;
Index : Node_Id;
Name : Node_Id;
begin
-- If the prefix is a member of an entry family, retrieve both
-- entry name and index. For a simple entry there is no index.
if Nkind (Pref) = N_Indexed_Component then
Entnam := Prefix (Pref);
Index := First (Expressions (Pref));
else
Entnam := Pref;
Index := Empty;
end if;
Entry_Id := Entity (Entnam);
-- Find the concurrent type in which this attribute is referenced
-- (there had better be one).
Conctyp := Current_Scope;
while not Is_Concurrent_Type (Conctyp) loop
Conctyp := Scope (Conctyp);
end loop;
-- Protected case
if Is_Protected_Type (Conctyp) then
case Corresponding_Runtime_Package (Conctyp) is
when System_Tasking_Protected_Objects_Entries =>
Name := New_Reference_To (RTE (RE_Protected_Count), Loc);
Call :=
Make_Function_Call (Loc,
Name => Name,
Parameter_Associations => New_List (
New_Reference_To
(Find_Protection_Object (Current_Scope), Loc),
Entry_Index_Expression
(Loc, Entry_Id, Index, Scope (Entry_Id))));
when System_Tasking_Protected_Objects_Single_Entry =>
Name :=
New_Reference_To (RTE (RE_Protected_Count_Entry), Loc);
Call :=
Make_Function_Call (Loc,
Name => Name,
Parameter_Associations => New_List (
New_Reference_To
(Find_Protection_Object (Current_Scope), Loc)));
when others =>
raise Program_Error;
end case;
-- Task case
else
Call :=
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Task_Count), Loc),
Parameter_Associations => New_List (
Entry_Index_Expression (Loc,
Entry_Id, Index, Scope (Entry_Id))));
end if;
-- The call returns type Natural but the context is universal integer
-- so any integer type is allowed. The attribute was already resolved
-- so its Etype is the required result type. If the base type of the
-- context type is other than Standard.Integer we put in a conversion
-- to the required type. This can be a normal typed conversion since
-- both input and output types of the conversion are integer types
if Base_Type (Typ) /= Base_Type (Standard_Integer) then
Rewrite (N, Convert_To (Typ, Call));
else
Rewrite (N, Call);
end if;
Analyze_And_Resolve (N, Typ);
end Count;
---------------------
-- Descriptor_Size --
---------------------
when Attribute_Descriptor_Size =>
-- Attribute Descriptor_Size is handled by the back end when applied
-- to an unconstrained array type.
if Is_Array_Type (Ptyp)
and then not Is_Constrained (Ptyp)
then
Apply_Universal_Integer_Attribute_Checks (N);
-- For any other type, the descriptor size is 0 because there is no
-- actual descriptor, but the result is not formally static.
else
Rewrite (N, Make_Integer_Literal (Loc, 0));
Analyze (N);
Set_Is_Static_Expression (N, False);
end if;
---------------
-- Elab_Body --
---------------
-- This processing is shared by Elab_Spec
-- What we do is to insert the following declarations
-- procedure tnn;
-- pragma Import (C, enn, "name___elabb/s");
-- and then the Elab_Body/Spec attribute is replaced by a reference
-- to this defining identifier.
when Attribute_Elab_Body |
Attribute_Elab_Spec =>
-- Leave attribute unexpanded in CodePeer mode: the gnat2scil
-- back-end knows how to handle these attributes directly.
if CodePeer_Mode then
return;
end if;
Elab_Body : declare
Ent : constant Entity_Id := Make_Temporary (Loc, 'E');
Str : String_Id;
Lang : Node_Id;
procedure Make_Elab_String (Nod : Node_Id);
-- Given Nod, an identifier, or a selected component, put the
-- image into the current string literal, with double underline
-- between components.
----------------------
-- Make_Elab_String --
----------------------
procedure Make_Elab_String (Nod : Node_Id) is
begin
if Nkind (Nod) = N_Selected_Component then
Make_Elab_String (Prefix (Nod));
case VM_Target is
when JVM_Target =>
Store_String_Char ('$');
when CLI_Target =>
Store_String_Char ('.');
when No_VM =>
Store_String_Char ('_');
Store_String_Char ('_');
end case;
Get_Name_String (Chars (Selector_Name (Nod)));
else
pragma Assert (Nkind (Nod) = N_Identifier);
Get_Name_String (Chars (Nod));
end if;
Store_String_Chars (Name_Buffer (1 .. Name_Len));
end Make_Elab_String;
-- Start of processing for Elab_Body/Elab_Spec
begin
-- First we need to prepare the string literal for the name of
-- the elaboration routine to be referenced.
Start_String;
Make_Elab_String (Pref);
if VM_Target = No_VM then
Store_String_Chars ("___elab");
Lang := Make_Identifier (Loc, Name_C);
else
Store_String_Chars ("._elab");
Lang := Make_Identifier (Loc, Name_Ada);
end if;
if Id = Attribute_Elab_Body then
Store_String_Char ('b');
else
Store_String_Char ('s');
end if;
Str := End_String;
Insert_Actions (N, New_List (
Make_Subprogram_Declaration (Loc,
Specification =>
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Ent)),
Make_Pragma (Loc,
Chars => Name_Import,
Pragma_Argument_Associations => New_List (
Make_Pragma_Argument_Association (Loc, Expression => Lang),
Make_Pragma_Argument_Association (Loc,
Expression => Make_Identifier (Loc, Chars (Ent))),
Make_Pragma_Argument_Association (Loc,
Expression => Make_String_Literal (Loc, Str))))));
Set_Entity (N, Ent);
Rewrite (N, New_Occurrence_Of (Ent, Loc));
end Elab_Body;
--------------------
-- Elab_Subp_Body --
--------------------
-- Always ignored. In CodePeer mode, gnat2scil knows how to handle
-- this attribute directly, and if we are not in CodePeer mode it is
-- entirely ignored ???
when Attribute_Elab_Subp_Body =>
return;
----------------
-- Elaborated --
----------------
-- Elaborated is always True for preelaborated units, predefined units,
-- pure units and units which have Elaborate_Body pragmas. These units
-- have no elaboration entity.
-- Note: The Elaborated attribute is never passed to the back end
when Attribute_Elaborated => Elaborated : declare
Ent : constant Entity_Id := Entity (Pref);
begin
if Present (Elaboration_Entity (Ent)) then
Rewrite (N,
Make_Op_Ne (Loc,
Left_Opnd =>
New_Occurrence_Of (Elaboration_Entity (Ent), Loc),
Right_Opnd =>
Make_Integer_Literal (Loc, Uint_0)));
Analyze_And_Resolve (N, Typ);
else
Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
end if;
end Elaborated;
--------------
-- Enum_Rep --
--------------
when Attribute_Enum_Rep => Enum_Rep :
begin
-- X'Enum_Rep (Y) expands to
-- target-type (Y)
-- This is simply a direct conversion from the enumeration type to
-- the target integer type, which is treated by the back end as a
-- normal integer conversion, treating the enumeration type as an
-- integer, which is exactly what we want! We set Conversion_OK to
-- make sure that the analyzer does not complain about what otherwise
-- might be an illegal conversion.
if Is_Non_Empty_List (Exprs) then
Rewrite (N,
OK_Convert_To (Typ, Relocate_Node (First (Exprs))));
-- X'Enum_Rep where X is an enumeration literal is replaced by
-- the literal value.
elsif Ekind (Entity (Pref)) = E_Enumeration_Literal then
Rewrite (N,
Make_Integer_Literal (Loc, Enumeration_Rep (Entity (Pref))));
-- If this is a renaming of a literal, recover the representation
-- of the original.
elsif Ekind (Entity (Pref)) = E_Constant
and then Present (Renamed_Object (Entity (Pref)))
and then
Ekind (Entity (Renamed_Object (Entity (Pref))))
= E_Enumeration_Literal
then
Rewrite (N,
Make_Integer_Literal (Loc,
Enumeration_Rep (Entity (Renamed_Object (Entity (Pref))))));
-- X'Enum_Rep where X is an object does a direct unchecked conversion
-- of the object value, as described for the type case above.
else
Rewrite (N,
OK_Convert_To (Typ, Relocate_Node (Pref)));
end if;
Set_Etype (N, Typ);
Analyze_And_Resolve (N, Typ);
end Enum_Rep;
--------------
-- Enum_Val --
--------------
when Attribute_Enum_Val => Enum_Val : declare
Expr : Node_Id;
Btyp : constant Entity_Id := Base_Type (Ptyp);
begin
-- X'Enum_Val (Y) expands to
-- [constraint_error when _rep_to_pos (Y, False) = -1, msg]
-- X!(Y);
Expr := Unchecked_Convert_To (Ptyp, First (Exprs));
Insert_Action (N,
Make_Raise_Constraint_Error (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To (TSS (Btyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations => New_List (
Relocate_Node (Duplicate_Subexpr (Expr)),
New_Occurrence_Of (Standard_False, Loc))),
Right_Opnd => Make_Integer_Literal (Loc, -1)),
Reason => CE_Range_Check_Failed));
Rewrite (N, Expr);
Analyze_And_Resolve (N, Ptyp);
end Enum_Val;
--------------
-- Exponent --
--------------
-- Transforms 'Exponent into a call to the floating-point attribute
-- function Exponent in Fat_xxx (where xxx is the root type)
when Attribute_Exponent =>
Expand_Fpt_Attribute_R (N);
------------------
-- External_Tag --
------------------
-- transforme X'External_Tag into Ada.Tags.External_Tag (X'tag)
when Attribute_External_Tag => External_Tag :
begin
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_External_Tag), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Tag,
Prefix => Prefix (N)))));
Analyze_And_Resolve (N, Standard_String);
end External_Tag;
-----------
-- First --
-----------
when Attribute_First =>
-- If the prefix type is a constrained packed array type which
-- already has a Packed_Array_Type representation defined, then
-- replace this attribute with a direct reference to 'First of the
-- appropriate index subtype (since otherwise the back end will try
-- to give us the value of 'First for this implementation type).
if Is_Constrained_Packed_Array (Ptyp) then
Rewrite (N,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
Analyze_And_Resolve (N, Typ);
elsif Is_Access_Type (Ptyp) then
Apply_Access_Check (N);
end if;
---------------
-- First_Bit --
---------------
-- Compute this if component clause was present, otherwise we leave the
-- computation to be completed in the back-end, since we don't know what
-- layout will be chosen.
when Attribute_First_Bit => First_Bit_Attr : declare
CE : constant Entity_Id := Entity (Selector_Name (Pref));
begin
-- In Ada 2005 (or later) if we have the standard nondefault
-- bit order, then we return the original value as given in
-- the component clause (RM 2005 13.5.2(3/2)).
if Present (Component_Clause (CE))
and then Ada_Version >= Ada_2005
and then not Reverse_Bit_Order (Scope (CE))
then
Rewrite (N,
Make_Integer_Literal (Loc,
Intval => Expr_Value (First_Bit (Component_Clause (CE)))));
Analyze_And_Resolve (N, Typ);
-- Otherwise (Ada 83/95 or Ada 2005 or later with reverse bit order),
-- rewrite with normalized value if we know it statically.
elsif Known_Static_Component_Bit_Offset (CE) then
Rewrite (N,
Make_Integer_Literal (Loc,
Component_Bit_Offset (CE) mod System_Storage_Unit));
Analyze_And_Resolve (N, Typ);
-- Otherwise left to back end, just do universal integer checks
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end First_Bit_Attr;
-----------------
-- Fixed_Value --
-----------------
-- We transform:
-- fixtype'Fixed_Value (integer-value)
-- into
-- fixtype(integer-value)
-- We do all the required analysis of the conversion here, because we do
-- not want this to go through the fixed-point conversion circuits. Note
-- that the back end always treats fixed-point as equivalent to the
-- corresponding integer type anyway.
when Attribute_Fixed_Value => Fixed_Value :
begin
Rewrite (N,
Make_Type_Conversion (Loc,
Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
Expression => Relocate_Node (First (Exprs))));
Set_Etype (N, Entity (Pref));
Set_Analyzed (N);
-- Note: it might appear that a properly analyzed unchecked conversion
-- would be just fine here, but that's not the case, since the full
-- range checks performed by the following call are critical!
Apply_Type_Conversion_Checks (N);
end Fixed_Value;
-----------
-- Floor --
-----------
-- Transforms 'Floor into a call to the floating-point attribute
-- function Floor in Fat_xxx (where xxx is the root type)
when Attribute_Floor =>
Expand_Fpt_Attribute_R (N);
----------
-- Fore --
----------
-- For the fixed-point type Typ:
-- Typ'Fore
-- expands into
-- Result_Type (System.Fore (Universal_Real (Type'First)),
-- Universal_Real (Type'Last))
-- Note that we know that the type is a non-static subtype, or Fore
-- would have itself been computed dynamically in Eval_Attribute.
when Attribute_Fore => Fore : begin
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Fore), Loc),
Parameter_Associations => New_List (
Convert_To (Universal_Real,
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Ptyp, Loc),
Attribute_Name => Name_First)),
Convert_To (Universal_Real,
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Ptyp, Loc),
Attribute_Name => Name_Last))))));
Analyze_And_Resolve (N, Typ);
end Fore;
--------------
-- Fraction --
--------------
-- Transforms 'Fraction into a call to the floating-point attribute
-- function Fraction in Fat_xxx (where xxx is the root type)
when Attribute_Fraction =>
Expand_Fpt_Attribute_R (N);
--------------
-- From_Any --
--------------
when Attribute_From_Any => From_Any : declare
P_Type : constant Entity_Id := Etype (Pref);
Decls : constant List_Id := New_List;
begin
Rewrite (N,
Build_From_Any_Call (P_Type,
Relocate_Node (First (Exprs)),
Decls));
Insert_Actions (N, Decls);
Analyze_And_Resolve (N, P_Type);
end From_Any;
--------------
-- Identity --
--------------
-- For an exception returns a reference to the exception data:
-- Exception_Id!(Prefix'Reference)
-- For a task it returns a reference to the _task_id component of
-- corresponding record:
-- taskV!(Prefix)._Task_Id, converted to the type Task_Id defined
-- in Ada.Task_Identification
when Attribute_Identity => Identity : declare
Id_Kind : Entity_Id;
begin
if Ptyp = Standard_Exception_Type then
Id_Kind := RTE (RE_Exception_Id);
if Present (Renamed_Object (Entity (Pref))) then
Set_Entity (Pref, Renamed_Object (Entity (Pref)));
end if;
Rewrite (N,
Unchecked_Convert_To (Id_Kind, Make_Reference (Loc, Pref)));
else
Id_Kind := RTE (RO_AT_Task_Id);
-- If the prefix is a task interface, the Task_Id is obtained
-- dynamically through a dispatching call, as for other task
-- attributes applied to interfaces.
if Ada_Version >= Ada_2005
and then Ekind (Ptyp) = E_Class_Wide_Type
and then Is_Interface (Ptyp)
and then Is_Task_Interface (Ptyp)
then
Rewrite (N,
Unchecked_Convert_To (Id_Kind,
Make_Selected_Component (Loc,
Prefix =>
New_Copy_Tree (Pref),
Selector_Name =>
Make_Identifier (Loc, Name_uDisp_Get_Task_Id))));
else
Rewrite (N,
Unchecked_Convert_To (Id_Kind, Concurrent_Ref (Pref)));
end if;
end if;
Analyze_And_Resolve (N, Id_Kind);
end Identity;
-----------
-- Image --
-----------
-- Image attribute is handled in separate unit Exp_Imgv
when Attribute_Image =>
Exp_Imgv.Expand_Image_Attribute (N);
---------
-- Img --
---------
-- X'Img is expanded to typ'Image (X), where typ is the type of X
when Attribute_Img => Img :
begin
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Ptyp, Loc),
Attribute_Name => Name_Image,
Expressions => New_List (Relocate_Node (Pref))));
Analyze_And_Resolve (N, Standard_String);
end Img;
-----------
-- Input --
-----------
when Attribute_Input => Input : declare
P_Type : constant Entity_Id := Entity (Pref);
B_Type : constant Entity_Id := Base_Type (P_Type);
U_Type : constant Entity_Id := Underlying_Type (P_Type);
Strm : constant Node_Id := First (Exprs);
Fname : Entity_Id;
Decl : Node_Id;
Call : Node_Id;
Prag : Node_Id;
Arg2 : Node_Id;
Rfunc : Node_Id;
Cntrl : Node_Id := Empty;
-- Value for controlling argument in call. Always Empty except in
-- the dispatching (class-wide type) case, where it is a reference
-- to the dummy object initialized to the right internal tag.
procedure Freeze_Stream_Subprogram (F : Entity_Id);
-- The expansion of the attribute reference may generate a call to
-- a user-defined stream subprogram that is frozen by the call. This
-- can lead to access-before-elaboration problem if the reference
-- appears in an object declaration and the subprogram body has not
-- been seen. The freezing of the subprogram requires special code
-- because it appears in an expanded context where expressions do
-- not freeze their constituents.
------------------------------
-- Freeze_Stream_Subprogram --
------------------------------
procedure Freeze_Stream_Subprogram (F : Entity_Id) is
Decl : constant Node_Id := Unit_Declaration_Node (F);
Bod : Node_Id;
begin
-- If this is user-defined subprogram, the corresponding
-- stream function appears as a renaming-as-body, and the
-- user subprogram must be retrieved by tree traversal.
if Present (Decl)
and then Nkind (Decl) = N_Subprogram_Declaration
and then Present (Corresponding_Body (Decl))
then
Bod := Corresponding_Body (Decl);
if Nkind (Unit_Declaration_Node (Bod)) =
N_Subprogram_Renaming_Declaration
then
Set_Is_Frozen (Entity (Name (Unit_Declaration_Node (Bod))));
end if;
end if;
end Freeze_Stream_Subprogram;
-- Start of processing for Input
begin
-- If no underlying type, we have an error that will be diagnosed
-- elsewhere, so here we just completely ignore the expansion.
if No (U_Type) then
return;
end if;
-- If there is a TSS for Input, just call it
Fname := Find_Stream_Subprogram (P_Type, TSS_Stream_Input);
if Present (Fname) then
null;
else
-- If there is a Stream_Convert pragma, use it, we rewrite
-- sourcetyp'Input (stream)
-- as
-- sourcetyp (streamread (strmtyp'Input (stream)));
-- where streamread is the given Read function that converts an
-- argument of type strmtyp to type sourcetyp or a type from which
-- it is derived (extra conversion required for the derived case).
Prag := Get_Stream_Convert_Pragma (P_Type);
if Present (Prag) then
Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
Rfunc := Entity (Expression (Arg2));
Rewrite (N,
Convert_To (B_Type,
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Rfunc, Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of
(Etype (First_Formal (Rfunc)), Loc),
Attribute_Name => Name_Input,
Expressions => Exprs)))));
Analyze_And_Resolve (N, B_Type);
return;
-- Elementary types
elsif Is_Elementary_Type (U_Type) then
-- A special case arises if we have a defined _Read routine,
-- since in this case we are required to call this routine.
if Present (TSS (Base_Type (U_Type), TSS_Stream_Read)) then
Build_Record_Or_Elementary_Input_Function
(Loc, U_Type, Decl, Fname);
Insert_Action (N, Decl);
-- For normal cases, we call the I_xxx routine directly
else
Rewrite (N, Build_Elementary_Input_Call (N));
Analyze_And_Resolve (N, P_Type);
return;
end if;
-- Array type case
elsif Is_Array_Type (U_Type) then
Build_Array_Input_Function (Loc, U_Type, Decl, Fname);
Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
-- Dispatching case with class-wide type
elsif Is_Class_Wide_Type (P_Type) then
-- No need to do anything else compiling under restriction
-- No_Dispatching_Calls. During the semantic analysis we
-- already notified such violation.
if Restriction_Active (No_Dispatching_Calls) then
return;
end if;
declare
Rtyp : constant Entity_Id := Root_Type (P_Type);
Dnn : Entity_Id;
Decl : Node_Id;
Expr : Node_Id;
begin
-- Read the internal tag (RM 13.13.2(34)) and use it to
-- initialize a dummy tag object:
-- Dnn : Ada.Tags.Tag :=
-- Descendant_Tag (String'Input (Strm), P_Type);
-- This dummy object is used only to provide a controlling
-- argument for the eventual _Input call. Descendant_Tag is
-- called rather than Internal_Tag to ensure that we have a
-- tag for a type that is descended from the prefix type and
-- declared at the same accessibility level (the exception
-- Tag_Error will be raised otherwise). The level check is
-- required for Ada 2005 because tagged types can be
-- extended in nested scopes (AI-344).
Expr :=
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Descendant_Tag), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Standard_String, Loc),
Attribute_Name => Name_Input,
Expressions => New_List (
Relocate_Node (Duplicate_Subexpr (Strm)))),
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (P_Type, Loc),
Attribute_Name => Name_Tag)));
Dnn := Make_Temporary (Loc, 'D', Expr);
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Dnn,
Object_Definition =>
New_Occurrence_Of (RTE (RE_Tag), Loc),
Expression => Expr);
Insert_Action (N, Decl);
-- Now we need to get the entity for the call, and construct
-- a function call node, where we preset a reference to Dnn
-- as the controlling argument (doing an unchecked convert
-- to the class-wide tagged type to make it look like a real
-- tagged object).
Fname := Find_Prim_Op (Rtyp, TSS_Stream_Input);
Cntrl :=
Unchecked_Convert_To (P_Type,
New_Occurrence_Of (Dnn, Loc));
Set_Etype (Cntrl, P_Type);
Set_Parent (Cntrl, N);
end;
-- For tagged types, use the primitive Input function
elsif Is_Tagged_Type (U_Type) then
Fname := Find_Prim_Op (U_Type, TSS_Stream_Input);
-- All other record type cases, including protected records. The
-- latter only arise for expander generated code for handling
-- shared passive partition access.
else
pragma Assert
(Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
-- Ada 2005 (AI-216): Program_Error is raised executing default
-- implementation of the Input attribute of an unchecked union
-- type if the type lacks default discriminant values.
if Is_Unchecked_Union (Base_Type (U_Type))
and then No (Discriminant_Constraint (U_Type))
then
Insert_Action (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction));
return;
end if;
-- Build the type's Input function, passing the subtype rather
-- than its base type, because checks are needed in the case of
-- constrained discriminants (see Ada 2012 AI05-0192).
Build_Record_Or_Elementary_Input_Function
(Loc, U_Type, Decl, Fname);
Insert_Action (N, Decl);
if Nkind (Parent (N)) = N_Object_Declaration
and then Is_Record_Type (U_Type)
then
-- The stream function may contain calls to user-defined
-- Read procedures for individual components.
declare
Comp : Entity_Id;
Func : Entity_Id;
begin
Comp := First_Component (U_Type);
while Present (Comp) loop
Func :=
Find_Stream_Subprogram
(Etype (Comp), TSS_Stream_Read);
if Present (Func) then
Freeze_Stream_Subprogram (Func);
end if;
Next_Component (Comp);
end loop;
end;
end if;
end if;
end if;
-- If we fall through, Fname is the function to be called. The result
-- is obtained by calling the appropriate function, then converting
-- the result. The conversion does a subtype check.
Call :=
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Fname, Loc),
Parameter_Associations => New_List (
Relocate_Node (Strm)));
Set_Controlling_Argument (Call, Cntrl);
Rewrite (N, Unchecked_Convert_To (P_Type, Call));
Analyze_And_Resolve (N, P_Type);
if Nkind (Parent (N)) = N_Object_Declaration then
Freeze_Stream_Subprogram (Fname);
end if;
end Input;
-------------------
-- Integer_Value --
-------------------
-- We transform
-- inttype'Fixed_Value (fixed-value)
-- into
-- inttype(integer-value))
-- we do all the required analysis of the conversion here, because we do
-- not want this to go through the fixed-point conversion circuits. Note
-- that the back end always treats fixed-point as equivalent to the
-- corresponding integer type anyway.
when Attribute_Integer_Value => Integer_Value :
begin
Rewrite (N,
Make_Type_Conversion (Loc,
Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
Expression => Relocate_Node (First (Exprs))));
Set_Etype (N, Entity (Pref));
Set_Analyzed (N);
-- Note: it might appear that a properly analyzed unchecked conversion
-- would be just fine here, but that's not the case, since the full
-- range checks performed by the following call are critical!
Apply_Type_Conversion_Checks (N);
end Integer_Value;
-------------------
-- Invalid_Value --
-------------------
when Attribute_Invalid_Value =>
Rewrite (N, Get_Simple_Init_Val (Ptyp, N));
----------
-- Last --
----------
when Attribute_Last =>
-- If the prefix type is a constrained packed array type which
-- already has a Packed_Array_Type representation defined, then
-- replace this attribute with a direct reference to 'Last of the
-- appropriate index subtype (since otherwise the back end will try
-- to give us the value of 'Last for this implementation type).
if Is_Constrained_Packed_Array (Ptyp) then
Rewrite (N,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
Analyze_And_Resolve (N, Typ);
elsif Is_Access_Type (Ptyp) then
Apply_Access_Check (N);
end if;
--------------
-- Last_Bit --
--------------
-- We compute this if a component clause was present, otherwise we leave
-- the computation up to the back end, since we don't know what layout
-- will be chosen.
when Attribute_Last_Bit => Last_Bit_Attr : declare
CE : constant Entity_Id := Entity (Selector_Name (Pref));
begin
-- In Ada 2005 (or later) if we have the standard nondefault
-- bit order, then we return the original value as given in
-- the component clause (RM 2005 13.5.2(4/2)).
if Present (Component_Clause (CE))
and then Ada_Version >= Ada_2005
and then not Reverse_Bit_Order (Scope (CE))
then
Rewrite (N,
Make_Integer_Literal (Loc,
Intval => Expr_Value (Last_Bit (Component_Clause (CE)))));
Analyze_And_Resolve (N, Typ);
-- Otherwise (Ada 83/95 or Ada 2005 or later with reverse bit order),
-- rewrite with normalized value if we know it statically.
elsif Known_Static_Component_Bit_Offset (CE)
and then Known_Static_Esize (CE)
then
Rewrite (N,
Make_Integer_Literal (Loc,
Intval => (Component_Bit_Offset (CE) mod System_Storage_Unit)
+ Esize (CE) - 1));
Analyze_And_Resolve (N, Typ);
-- Otherwise leave to back end, just apply universal integer checks
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end Last_Bit_Attr;
------------------
-- Leading_Part --
------------------
-- Transforms 'Leading_Part into a call to the floating-point attribute
-- function Leading_Part in Fat_xxx (where xxx is the root type)
-- Note: strictly, we should generate special case code to deal with
-- absurdly large positive arguments (greater than Integer'Last), which
-- result in returning the first argument unchanged, but it hardly seems
-- worth the effort. We raise constraint error for absurdly negative
-- arguments which is fine.
when Attribute_Leading_Part =>
Expand_Fpt_Attribute_RI (N);
------------
-- Length --
------------
when Attribute_Length => Length : declare
Ityp : Entity_Id;
Xnum : Uint;
begin
-- Processing for packed array types
if Is_Array_Type (Ptyp) and then Is_Packed (Ptyp) then
Ityp := Get_Index_Subtype (N);
-- If the index type, Ityp, is an enumeration type with holes,
-- then we calculate X'Length explicitly using
-- Typ'Max
-- (0, Ityp'Pos (X'Last (N)) -
-- Ityp'Pos (X'First (N)) + 1);
-- Since the bounds in the template are the representation values
-- and the back end would get the wrong value.
if Is_Enumeration_Type (Ityp)
and then Present (Enum_Pos_To_Rep (Base_Type (Ityp)))
then
if No (Exprs) then
Xnum := Uint_1;
else
Xnum := Expr_Value (First (Expressions (N)));
end if;
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Typ, Loc),
Attribute_Name => Name_Max,
Expressions => New_List
(Make_Integer_Literal (Loc, 0),
Make_Op_Add (Loc,
Left_Opnd =>
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ityp, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr (Pref),
Attribute_Name => Name_Last,
Expressions => New_List (
Make_Integer_Literal (Loc, Xnum))))),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ityp, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
Duplicate_Subexpr_No_Checks (Pref),
Attribute_Name => Name_First,
Expressions => New_List (
Make_Integer_Literal (Loc, Xnum)))))),
Right_Opnd => Make_Integer_Literal (Loc, 1)))));
Analyze_And_Resolve (N, Typ, Suppress => All_Checks);
return;
-- If the prefix type is a constrained packed array type which
-- already has a Packed_Array_Type representation defined, then
-- replace this attribute with a direct reference to 'Range_Length
-- of the appropriate index subtype (since otherwise the back end
-- will try to give us the value of 'Length for this
-- implementation type).
elsif Is_Constrained (Ptyp) then
Rewrite (N,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Range_Length,
Prefix => New_Reference_To (Ityp, Loc)));
Analyze_And_Resolve (N, Typ);
end if;
-- Access type case
elsif Is_Access_Type (Ptyp) then
Apply_Access_Check (N);
-- If the designated type is a packed array type, then we convert
-- the reference to:
-- typ'Max (0, 1 +
-- xtyp'Pos (Pref'Last (Expr)) -
-- xtyp'Pos (Pref'First (Expr)));
-- This is a bit complex, but it is the easiest thing to do that
-- works in all cases including enum types with holes xtyp here
-- is the appropriate index type.
declare
Dtyp : constant Entity_Id := Designated_Type (Ptyp);
Xtyp : Entity_Id;
begin
if Is_Array_Type (Dtyp) and then Is_Packed (Dtyp) then
Xtyp := Get_Index_Subtype (N);
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Typ, Loc),
Attribute_Name => Name_Max,
Expressions => New_List (
Make_Integer_Literal (Loc, 0),
Make_Op_Add (Loc,
Make_Integer_Literal (Loc, 1),
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Xtyp, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr (Pref),
Attribute_Name => Name_Last,
Expressions =>
New_Copy_List (Exprs)))),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Xtyp, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
Duplicate_Subexpr_No_Checks (Pref),
Attribute_Name => Name_First,
Expressions =>
New_Copy_List (Exprs)))))))));
Analyze_And_Resolve (N, Typ);
end if;
end;
-- Otherwise leave it to the back end
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end Length;
-- The expansion of this attribute is carried out when the target loop
-- is processed. See Expand_Loop_Entry_Attributes for details.
when Attribute_Loop_Entry =>
null;
-------------
-- Machine --
-------------
-- Transforms 'Machine into a call to the floating-point attribute
-- function Machine in Fat_xxx (where xxx is the root type)
when Attribute_Machine =>
Expand_Fpt_Attribute_R (N);
----------------------
-- Machine_Rounding --
----------------------
-- Transforms 'Machine_Rounding into a call to the floating-point
-- attribute function Machine_Rounding in Fat_xxx (where xxx is the root
-- type). Expansion is avoided for cases the back end can handle
-- directly.
when Attribute_Machine_Rounding =>
if not Is_Inline_Floating_Point_Attribute (N) then
Expand_Fpt_Attribute_R (N);
end if;
------------------
-- Machine_Size --
------------------
-- Machine_Size is equivalent to Object_Size, so transform it into
-- Object_Size and that way the back end never sees Machine_Size.
when Attribute_Machine_Size =>
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => Prefix (N),
Attribute_Name => Name_Object_Size));
Analyze_And_Resolve (N, Typ);
--------------
-- Mantissa --
--------------
-- The only case that can get this far is the dynamic case of the old
-- Ada 83 Mantissa attribute for the fixed-point case. For this case,
-- we expand:
-- typ'Mantissa
-- into
-- ityp (System.Mantissa.Mantissa_Value
-- (Integer'Integer_Value (typ'First),
-- Integer'Integer_Value (typ'Last)));
when Attribute_Mantissa => Mantissa : begin
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name => New_Occurrence_Of (RTE (RE_Mantissa_Value), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Standard_Integer, Loc),
Attribute_Name => Name_Integer_Value,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Attribute_Name => Name_First))),
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Standard_Integer, Loc),
Attribute_Name => Name_Integer_Value,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Attribute_Name => Name_Last)))))));
Analyze_And_Resolve (N, Typ);
end Mantissa;
----------------------------------
-- Max_Size_In_Storage_Elements --
----------------------------------
when Attribute_Max_Size_In_Storage_Elements => declare
Typ : constant Entity_Id := Etype (N);
Attr : Node_Id;
Conversion_Added : Boolean := False;
-- A flag which tracks whether the original attribute has been
-- wrapped inside a type conversion.
begin
Apply_Universal_Integer_Attribute_Checks (N);
-- The universal integer check may sometimes add a type conversion,
-- retrieve the original attribute reference from the expression.
Attr := N;
if Nkind (Attr) = N_Type_Conversion then
Attr := Expression (Attr);
Conversion_Added := True;
end if;
-- Heap-allocated controlled objects contain two extra pointers which
-- are not part of the actual type. Transform the attribute reference
-- into a runtime expression to add the size of the hidden header.
-- Do not perform this expansion on .NET/JVM targets because the
-- two pointers are already present in the type.
if VM_Target = No_VM
and then Nkind (Attr) = N_Attribute_Reference
and then Needs_Finalization (Ptyp)
and then not Header_Size_Added (Attr)
then
Set_Header_Size_Added (Attr);
-- Generate:
-- P'Max_Size_In_Storage_Elements +
-- Universal_Integer
-- (Header_Size_With_Padding (Ptyp'Alignment))
Rewrite (Attr,
Make_Op_Add (Loc,
Left_Opnd => Relocate_Node (Attr),
Right_Opnd =>
Convert_To (Universal_Integer,
Make_Function_Call (Loc,
Name =>
New_Reference_To
(RTE (RE_Header_Size_With_Padding), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
New_Reference_To (Ptyp, Loc),
Attribute_Name => Name_Alignment))))));
-- Add a conversion to the target type
if not Conversion_Added then
Rewrite (Attr,
Make_Type_Conversion (Loc,
Subtype_Mark => New_Reference_To (Typ, Loc),
Expression => Relocate_Node (Attr)));
end if;
Analyze (Attr);
return;
end if;
end;
--------------------
-- Mechanism_Code --
--------------------
when Attribute_Mechanism_Code =>
-- We must replace the prefix in the renamed case
if Is_Entity_Name (Pref)
and then Present (Alias (Entity (Pref)))
then
Set_Renamed_Subprogram (Pref, Alias (Entity (Pref)));
end if;
---------
-- Mod --
---------
when Attribute_Mod => Mod_Case : declare
Arg : constant Node_Id := Relocate_Node (First (Exprs));
Hi : constant Node_Id := Type_High_Bound (Etype (Arg));
Modv : constant Uint := Modulus (Btyp);
begin
-- This is not so simple. The issue is what type to use for the
-- computation of the modular value.
-- The easy case is when the modulus value is within the bounds
-- of the signed integer type of the argument. In this case we can
-- just do the computation in that signed integer type, and then
-- do an ordinary conversion to the target type.
if Modv <= Expr_Value (Hi) then
Rewrite (N,
Convert_To (Btyp,
Make_Op_Mod (Loc,
Left_Opnd => Arg,
Right_Opnd => Make_Integer_Literal (Loc, Modv))));
-- Here we know that the modulus is larger than type'Last of the
-- integer type. There are two cases to consider:
-- a) The integer value is non-negative. In this case, it is
-- returned as the result (since it is less than the modulus).
-- b) The integer value is negative. In this case, we know that the
-- result is modulus + value, where the value might be as small as
-- -modulus. The trouble is what type do we use to do the subtract.
-- No type will do, since modulus can be as big as 2**64, and no
-- integer type accommodates this value. Let's do bit of algebra
-- modulus + value
-- = modulus - (-value)
-- = (modulus - 1) - (-value - 1)
-- Now modulus - 1 is certainly in range of the modular type.
-- -value is in the range 1 .. modulus, so -value -1 is in the
-- range 0 .. modulus-1 which is in range of the modular type.
-- Furthermore, (-value - 1) can be expressed as -(value + 1)
-- which we can compute using the integer base type.
-- Once this is done we analyze the if expression without range
-- checks, because we know everything is in range, and we want
-- to prevent spurious warnings on either branch.
else
Rewrite (N,
Make_If_Expression (Loc,
Expressions => New_List (
Make_Op_Ge (Loc,
Left_Opnd => Duplicate_Subexpr (Arg),
Right_Opnd => Make_Integer_Literal (Loc, 0)),
Convert_To (Btyp,
Duplicate_Subexpr_No_Checks (Arg)),
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Integer_Literal (Loc,
Intval => Modv - 1),
Right_Opnd =>
Convert_To (Btyp,
Make_Op_Minus (Loc,
Right_Opnd =>
Make_Op_Add (Loc,
Left_Opnd => Duplicate_Subexpr_No_Checks (Arg),
Right_Opnd =>
Make_Integer_Literal (Loc,
Intval => 1))))))));
end if;
Analyze_And_Resolve (N, Btyp, Suppress => All_Checks);
end Mod_Case;
-----------
-- Model --
-----------
-- Transforms 'Model into a call to the floating-point attribute
-- function Model in Fat_xxx (where xxx is the root type)
when Attribute_Model =>
Expand_Fpt_Attribute_R (N);
-----------------
-- Object_Size --
-----------------
-- The processing for Object_Size shares the processing for Size
---------
-- Old --
---------
when Attribute_Old => Old : declare
Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', Pref);
Subp : Node_Id;
Asn_Stm : Node_Id;
begin
-- If assertions are disabled, no need to create the declaration
-- that preserves the value.
if not Assertions_Enabled then
return;
end if;
-- Find the nearest subprogram body, ignoring _Preconditions
Subp := N;
loop
Subp := Parent (Subp);
exit when Nkind (Subp) = N_Subprogram_Body
and then Chars (Defining_Entity (Subp)) /= Name_uPostconditions;
end loop;
-- Insert the initialized object declaration at the start of the
-- subprogram's declarations.
Asn_Stm :=
Make_Object_Declaration (Loc,
Defining_Identifier => Tnn,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (Etype (N), Loc),
Expression => Pref);
-- Push the subprogram's scope, so that the object will be analyzed
-- in that context (rather than the context of the Precondition
-- subprogram) and will have its Scope set properly.
if Present (Corresponding_Spec (Subp)) then
Push_Scope (Corresponding_Spec (Subp));
else
Push_Scope (Defining_Entity (Subp));
end if;
if Is_Empty_List (Declarations (Subp)) then
Set_Declarations (Subp, New_List (Asn_Stm));
Analyze (Asn_Stm);
else
Insert_Action (First (Declarations (Subp)), Asn_Stm);
end if;
Pop_Scope;
Rewrite (N, New_Occurrence_Of (Tnn, Loc));
end Old;
----------------------
-- Overlaps_Storage --
----------------------
when Attribute_Overlaps_Storage => Overlaps_Storage : declare
Loc : constant Source_Ptr := Sloc (N);
X : constant Node_Id := Prefix (N);
Y : constant Node_Id := First (Expressions (N));
-- The argumens
X_Addr, Y_Addr : Node_Id;
-- the expressions for their integer addresses
X_Size, Y_Size : Node_Id;
-- the expressions for their sizes
Cond : Node_Id;
begin
-- Attribute expands into:
-- if X'Address < Y'address then
-- (X'address + X'Size - 1) >= Y'address
-- else
-- (Y'address + Y'size - 1) >= X'Address
-- end if;
-- with the proper address operations. We convert addresses to
-- integer addresses to use predefined arithmetic. The size is
-- expressed in storage units.
X_Addr :=
Unchecked_Convert_To (RTE (RE_Integer_Address),
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Address,
Prefix => New_Copy_Tree (X)));
Y_Addr :=
Unchecked_Convert_To (RTE (RE_Integer_Address),
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Address,
Prefix => New_Copy_Tree (Y)));
X_Size :=
Make_Op_Divide (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Size,
Prefix => New_Copy_Tree (X)),
Right_Opnd =>
Make_Integer_Literal (Loc, System_Storage_Unit));
Y_Size :=
Make_Op_Divide (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Size,
Prefix => New_Copy_Tree (Y)),
Right_Opnd =>
Make_Integer_Literal (Loc, System_Storage_Unit));
Cond :=
Make_Op_Le (Loc,
Left_Opnd => X_Addr,
Right_Opnd => Y_Addr);
Rewrite (N,
Make_If_Expression (Loc,
New_List (
Cond,
Make_Op_Ge (Loc,
Left_Opnd =>
Make_Op_Add (Loc,
Left_Opnd => X_Addr,
Right_Opnd =>
Make_Op_Subtract (Loc,
Left_Opnd => X_Size,
Right_Opnd => Make_Integer_Literal (Loc, 1))),
Right_Opnd => Y_Addr),
Make_Op_Ge (Loc,
Make_Op_Add (Loc,
Left_Opnd => Y_Addr,
Right_Opnd =>
Make_Op_Subtract (Loc,
Left_Opnd => Y_Size,
Right_Opnd => Make_Integer_Literal (Loc, 1))),
Right_Opnd => X_Addr))));
Analyze_And_Resolve (N, Standard_Boolean);
end Overlaps_Storage;
------------
-- Output --
------------
when Attribute_Output => Output : declare
P_Type : constant Entity_Id := Entity (Pref);
U_Type : constant Entity_Id := Underlying_Type (P_Type);
Pname : Entity_Id;
Decl : Node_Id;
Prag : Node_Id;
Arg3 : Node_Id;
Wfunc : Node_Id;
begin
-- If no underlying type, we have an error that will be diagnosed
-- elsewhere, so here we just completely ignore the expansion.
if No (U_Type) then
return;
end if;
-- If TSS for Output is present, just call it
Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Output);
if Present (Pname) then
null;
else
-- If there is a Stream_Convert pragma, use it, we rewrite
-- sourcetyp'Output (stream, Item)
-- as
-- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
-- where strmwrite is the given Write function that converts an
-- argument of type sourcetyp or a type acctyp, from which it is
-- derived to type strmtyp. The conversion to acttyp is required
-- for the derived case.
Prag := Get_Stream_Convert_Pragma (P_Type);
if Present (Prag) then
Arg3 :=
Next (Next (First (Pragma_Argument_Associations (Prag))));
Wfunc := Entity (Expression (Arg3));
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
Attribute_Name => Name_Output,
Expressions => New_List (
Relocate_Node (First (Exprs)),
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Wfunc, Loc),
Parameter_Associations => New_List (
OK_Convert_To (Etype (First_Formal (Wfunc)),
Relocate_Node (Next (First (Exprs)))))))));
Analyze (N);
return;
-- For elementary types, we call the W_xxx routine directly.
-- Note that the effect of Write and Output is identical for
-- the case of an elementary type, since there are no
-- discriminants or bounds.
elsif Is_Elementary_Type (U_Type) then
-- A special case arises if we have a defined _Write routine,
-- since in this case we are required to call this routine.
if Present (TSS (Base_Type (U_Type), TSS_Stream_Write)) then
Build_Record_Or_Elementary_Output_Procedure
(Loc, U_Type, Decl, Pname);
Insert_Action (N, Decl);
-- For normal cases, we call the W_xxx routine directly
else
Rewrite (N, Build_Elementary_Write_Call (N));
Analyze (N);
return;
end if;
-- Array type case
elsif Is_Array_Type (U_Type) then
Build_Array_Output_Procedure (Loc, U_Type, Decl, Pname);
Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
-- Class-wide case, first output external tag, then dispatch
-- to the appropriate primitive Output function (RM 13.13.2(31)).
elsif Is_Class_Wide_Type (P_Type) then
-- No need to do anything else compiling under restriction
-- No_Dispatching_Calls. During the semantic analysis we
-- already notified such violation.
if Restriction_Active (No_Dispatching_Calls) then
return;
end if;
Tag_Write : declare
Strm : constant Node_Id := First (Exprs);
Item : constant Node_Id := Next (Strm);
begin
-- Ada 2005 (AI-344): Check that the accessibility level
-- of the type of the output object is not deeper than
-- that of the attribute's prefix type.
-- if Get_Access_Level (Item'Tag)
-- /= Get_Access_Level (P_Type'Tag)
-- then
-- raise Tag_Error;
-- end if;
-- String'Output (Strm, External_Tag (Item'Tag));
-- We cannot figure out a practical way to implement this
-- accessibility check on virtual machines, so we omit it.
if Ada_Version >= Ada_2005
and then Tagged_Type_Expansion
then
Insert_Action (N,
Make_Implicit_If_Statement (N,
Condition =>
Make_Op_Ne (Loc,
Left_Opnd =>
Build_Get_Access_Level (Loc,
Make_Attribute_Reference (Loc,
Prefix =>
Relocate_Node (
Duplicate_Subexpr (Item,
Name_Req => True)),
Attribute_Name => Name_Tag)),
Right_Opnd =>
Make_Integer_Literal (Loc,
Type_Access_Level (P_Type))),
Then_Statements =>
New_List (Make_Raise_Statement (Loc,
New_Occurrence_Of (
RTE (RE_Tag_Error), Loc)))));
end if;
Insert_Action (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Standard_String, Loc),
Attribute_Name => Name_Output,
Expressions => New_List (
Relocate_Node (Duplicate_Subexpr (Strm)),
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_External_Tag), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
Relocate_Node
(Duplicate_Subexpr (Item, Name_Req => True)),
Attribute_Name => Name_Tag))))));
end Tag_Write;
Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
-- Tagged type case, use the primitive Output function
elsif Is_Tagged_Type (U_Type) then
Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
-- All other record type cases, including protected records.
-- The latter only arise for expander generated code for
-- handling shared passive partition access.
else
pragma Assert
(Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
-- Ada 2005 (AI-216): Program_Error is raised when executing
-- the default implementation of the Output attribute of an
-- unchecked union type if the type lacks default discriminant
-- values.
if Is_Unchecked_Union (Base_Type (U_Type))
and then No (Discriminant_Constraint (U_Type))
then
Insert_Action (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction));
return;
end if;
Build_Record_Or_Elementary_Output_Procedure
(Loc, Base_Type (U_Type), Decl, Pname);
Insert_Action (N, Decl);
end if;
end if;
-- If we fall through, Pname is the name of the procedure to call
Rewrite_Stream_Proc_Call (Pname);
end Output;
---------
-- Pos --
---------
-- For enumeration types with a standard representation, Pos is
-- handled by the back end.
-- For enumeration types, with a non-standard representation we generate
-- a call to the _Rep_To_Pos function created when the type was frozen.
-- The call has the form
-- _rep_to_pos (expr, flag)
-- The parameter flag is True if range checks are enabled, causing
-- Program_Error to be raised if the expression has an invalid
-- representation, and False if range checks are suppressed.
-- For integer types, Pos is equivalent to a simple integer
-- conversion and we rewrite it as such
when Attribute_Pos => Pos :
declare
Etyp : Entity_Id := Base_Type (Entity (Pref));
begin
-- Deal with zero/non-zero boolean values
if Is_Boolean_Type (Etyp) then
Adjust_Condition (First (Exprs));
Etyp := Standard_Boolean;
Set_Prefix (N, New_Occurrence_Of (Standard_Boolean, Loc));
end if;
-- Case of enumeration type
if Is_Enumeration_Type (Etyp) then
-- Non-standard enumeration type (generate call)
if Present (Enum_Pos_To_Rep (Etyp)) then
Append_To (Exprs, Rep_To_Pos_Flag (Etyp, Loc));
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name =>
New_Reference_To (TSS (Etyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations => Exprs)));
Analyze_And_Resolve (N, Typ);
-- Standard enumeration type (do universal integer check)
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
-- Deal with integer types (replace by conversion)
elsif Is_Integer_Type (Etyp) then
Rewrite (N, Convert_To (Typ, First (Exprs)));
Analyze_And_Resolve (N, Typ);
end if;
end Pos;
--------------
-- Position --
--------------
-- We compute this if a component clause was present, otherwise we leave
-- the computation up to the back end, since we don't know what layout
-- will be chosen.
when Attribute_Position => Position_Attr :
declare
CE : constant Entity_Id := Entity (Selector_Name (Pref));
begin
if Present (Component_Clause (CE)) then
-- In Ada 2005 (or later) if we have the standard nondefault
-- bit order, then we return the original value as given in
-- the component clause (RM 2005 13.5.2(2/2)).
if Ada_Version >= Ada_2005
and then not Reverse_Bit_Order (Scope (CE))
then
Rewrite (N,
Make_Integer_Literal (Loc,
Intval => Expr_Value (Position (Component_Clause (CE)))));
-- Otherwise (Ada 83 or 95, or reverse bit order specified in
-- later Ada version), return the normalized value.
else
Rewrite (N,
Make_Integer_Literal (Loc,
Intval => Component_Bit_Offset (CE) / System_Storage_Unit));
end if;
Analyze_And_Resolve (N, Typ);
-- If back end is doing things, just apply universal integer checks
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end Position_Attr;
----------
-- Pred --
----------
-- 1. Deal with enumeration types with holes
-- 2. For floating-point, generate call to attribute function
-- 3. For other cases, deal with constraint checking
when Attribute_Pred => Pred :
declare
Etyp : constant Entity_Id := Base_Type (Ptyp);
begin
-- For enumeration types with non-standard representations, we
-- expand typ'Pred (x) into
-- Pos_To_Rep (Rep_To_Pos (x) - 1)
-- If the representation is contiguous, we compute instead
-- Lit1 + Rep_to_Pos (x -1), to catch invalid representations.
-- The conversion function Enum_Pos_To_Rep is defined on the
-- base type, not the subtype, so we have to use the base type
-- explicitly for this and other enumeration attributes.
if Is_Enumeration_Type (Ptyp)
and then Present (Enum_Pos_To_Rep (Etyp))
then
if Has_Contiguous_Rep (Etyp) then
Rewrite (N,
Unchecked_Convert_To (Ptyp,
Make_Op_Add (Loc,
Left_Opnd =>
Make_Integer_Literal (Loc,
Enumeration_Rep (First_Literal (Ptyp))),
Right_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To
(TSS (Etyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations =>
New_List (
Unchecked_Convert_To (Ptyp,
Make_Op_Subtract (Loc,
Left_Opnd =>
Unchecked_Convert_To (Standard_Integer,
Relocate_Node (First (Exprs))),
Right_Opnd =>
Make_Integer_Literal (Loc, 1))),
Rep_To_Pos_Flag (Ptyp, Loc))))));
else
-- Add Boolean parameter True, to request program errror if
-- we have a bad representation on our hands. If checks are
-- suppressed, then add False instead
Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
Rewrite (N,
Make_Indexed_Component (Loc,
Prefix =>
New_Reference_To
(Enum_Pos_To_Rep (Etyp), Loc),
Expressions => New_List (
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To
(TSS (Etyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations => Exprs),
Right_Opnd => Make_Integer_Literal (Loc, 1)))));
end if;
Analyze_And_Resolve (N, Typ);
-- For floating-point, we transform 'Pred into a call to the Pred
-- floating-point attribute function in Fat_xxx (xxx is root type)
elsif Is_Floating_Point_Type (Ptyp) then
Expand_Fpt_Attribute_R (N);
Analyze_And_Resolve (N, Typ);
-- For modular types, nothing to do (no overflow, since wraps)
elsif Is_Modular_Integer_Type (Ptyp) then
null;
-- For other types, if argument is marked as needing a range check or
-- overflow checking is enabled, we must generate a check.
elsif not Overflow_Checks_Suppressed (Ptyp)
or else Do_Range_Check (First (Exprs))
then
Set_Do_Range_Check (First (Exprs), False);
Expand_Pred_Succ (N);
end if;
end Pred;
--------------
-- Priority --
--------------
-- Ada 2005 (AI-327): Dynamic ceiling priorities
-- We rewrite X'Priority as the following run-time call:
-- Get_Ceiling (X._Object)
-- Note that although X'Priority is notionally an object, it is quite
-- deliberately not defined as an aliased object in the RM. This means
-- that it works fine to rewrite it as a call, without having to worry
-- about complications that would other arise from X'Priority'Access,
-- which is illegal, because of the lack of aliasing.
when Attribute_Priority =>
declare
Call : Node_Id;
Conctyp : Entity_Id;
Object_Parm : Node_Id;
Subprg : Entity_Id;
RT_Subprg_Name : Node_Id;
begin
-- Look for the enclosing concurrent type
Conctyp := Current_Scope;
while not Is_Concurrent_Type (Conctyp) loop
Conctyp := Scope (Conctyp);
end loop;
pragma Assert (Is_Protected_Type (Conctyp));
-- Generate the actual of the call
Subprg := Current_Scope;
while not Present (Protected_Body_Subprogram (Subprg)) loop
Subprg := Scope (Subprg);
end loop;
-- Use of 'Priority inside protected entries and barriers (in
-- both cases the type of the first formal of their expanded
-- subprogram is Address)
if Etype (First_Entity (Protected_Body_Subprogram (Subprg)))
= RTE (RE_Address)
then
declare
New_Itype : Entity_Id;
begin
-- In the expansion of protected entries the type of the
-- first formal of the Protected_Body_Subprogram is an
-- Address. In order to reference the _object component
-- we generate:
-- type T is access p__ptTV;
-- freeze T []
New_Itype := Create_Itype (E_Access_Type, N);
Set_Etype (New_Itype, New_Itype);
Set_Directly_Designated_Type (New_Itype,
Corresponding_Record_Type (Conctyp));
Freeze_Itype (New_Itype, N);
-- Generate:
-- T!(O)._object'unchecked_access
Object_Parm :=
Make_Attribute_Reference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix =>
Unchecked_Convert_To (New_Itype,
New_Reference_To
(First_Entity
(Protected_Body_Subprogram (Subprg)),
Loc)),
Selector_Name =>
Make_Identifier (Loc, Name_uObject)),
Attribute_Name => Name_Unchecked_Access);
end;
-- Use of 'Priority inside a protected subprogram
else
Object_Parm :=
Make_Attribute_Reference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix => New_Reference_To
(First_Entity
(Protected_Body_Subprogram (Subprg)),
Loc),
Selector_Name => Make_Identifier (Loc, Name_uObject)),
Attribute_Name => Name_Unchecked_Access);
end if;
-- Select the appropriate run-time subprogram
if Number_Entries (Conctyp) = 0 then
RT_Subprg_Name :=
New_Reference_To (RTE (RE_Get_Ceiling), Loc);
else
RT_Subprg_Name :=
New_Reference_To (RTE (RO_PE_Get_Ceiling), Loc);
end if;
Call :=
Make_Function_Call (Loc,
Name => RT_Subprg_Name,
Parameter_Associations => New_List (Object_Parm));
Rewrite (N, Call);
-- Avoid the generation of extra checks on the pointer to the
-- protected object.
Analyze_And_Resolve (N, Typ, Suppress => Access_Check);
end;
------------------
-- Range_Length --
------------------
when Attribute_Range_Length => Range_Length : begin
-- The only special processing required is for the case where
-- Range_Length is applied to an enumeration type with holes.
-- In this case we transform
-- X'Range_Length
-- to
-- X'Pos (X'Last) - X'Pos (X'First) + 1
-- So that the result reflects the proper Pos values instead
-- of the underlying representations.
if Is_Enumeration_Type (Ptyp)
and then Has_Non_Standard_Rep (Ptyp)
then
Rewrite (N,
Make_Op_Add (Loc,
Left_Opnd =>
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Pos,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Expressions => New_List (
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix => New_Occurrence_Of (Ptyp, Loc)))),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Pos,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Expressions => New_List (
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix => New_Occurrence_Of (Ptyp, Loc))))),
Right_Opnd => Make_Integer_Literal (Loc, 1)));
Analyze_And_Resolve (N, Typ);
-- For all other cases, the attribute is handled by the back end, but
-- we need to deal with the case of the range check on a universal
-- integer.
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end Range_Length;
----------
-- Read --
----------
when Attribute_Read => Read : declare
P_Type : constant Entity_Id := Entity (Pref);
B_Type : constant Entity_Id := Base_Type (P_Type);
U_Type : constant Entity_Id := Underlying_Type (P_Type);
Pname : Entity_Id;
Decl : Node_Id;
Prag : Node_Id;
Arg2 : Node_Id;
Rfunc : Node_Id;
Lhs : Node_Id;
Rhs : Node_Id;
begin
-- If no underlying type, we have an error that will be diagnosed
-- elsewhere, so here we just completely ignore the expansion.
if No (U_Type) then
return;
end if;
-- The simple case, if there is a TSS for Read, just call it
Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Read);
if Present (Pname) then
null;
else
-- If there is a Stream_Convert pragma, use it, we rewrite
-- sourcetyp'Read (stream, Item)
-- as
-- Item := sourcetyp (strmread (strmtyp'Input (Stream)));
-- where strmread is the given Read function that converts an
-- argument of type strmtyp to type sourcetyp or a type from which
-- it is derived. The conversion to sourcetyp is required in the
-- latter case.
-- A special case arises if Item is a type conversion in which
-- case, we have to expand to:
-- Itemx := typex (strmread (strmtyp'Input (Stream)));
-- where Itemx is the expression of the type conversion (i.e.
-- the actual object), and typex is the type of Itemx.
Prag := Get_Stream_Convert_Pragma (P_Type);
if Present (Prag) then
Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
Rfunc := Entity (Expression (Arg2));
Lhs := Relocate_Node (Next (First (Exprs)));
Rhs :=
OK_Convert_To (B_Type,
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Rfunc, Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of
(Etype (First_Formal (Rfunc)), Loc),
Attribute_Name => Name_Input,
Expressions => New_List (
Relocate_Node (First (Exprs)))))));
if Nkind (Lhs) = N_Type_Conversion then
Lhs := Expression (Lhs);
Rhs := Convert_To (Etype (Lhs), Rhs);
end if;
Rewrite (N,
Make_Assignment_Statement (Loc,
Name => Lhs,
Expression => Rhs));
Set_Assignment_OK (Lhs);
Analyze (N);
return;
-- For elementary types, we call the I_xxx routine using the first
-- parameter and then assign the result into the second parameter.
-- We set Assignment_OK to deal with the conversion case.
elsif Is_Elementary_Type (U_Type) then
declare
Lhs : Node_Id;
Rhs : Node_Id;
begin
Lhs := Relocate_Node (Next (First (Exprs)));
Rhs := Build_Elementary_Input_Call (N);
if Nkind (Lhs) = N_Type_Conversion then
Lhs := Expression (Lhs);
Rhs := Convert_To (Etype (Lhs), Rhs);
end if;
Set_Assignment_OK (Lhs);
Rewrite (N,
Make_Assignment_Statement (Loc,
Name => Lhs,
Expression => Rhs));
Analyze (N);
return;
end;
-- Array type case
elsif Is_Array_Type (U_Type) then
Build_Array_Read_Procedure (N, U_Type, Decl, Pname);
Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
-- Tagged type case, use the primitive Read function. Note that
-- this will dispatch in the class-wide case which is what we want
elsif Is_Tagged_Type (U_Type) then
Pname := Find_Prim_Op (U_Type, TSS_Stream_Read);
-- All other record type cases, including protected records. The
-- latter only arise for expander generated code for handling
-- shared passive partition access.
else
pragma Assert
(Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
-- Ada 2005 (AI-216): Program_Error is raised when executing
-- the default implementation of the Read attribute of an
-- Unchecked_Union type.
if Is_Unchecked_Union (Base_Type (U_Type)) then
Insert_Action (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction));
end if;
if Has_Discriminants (U_Type)
and then Present
(Discriminant_Default_Value (First_Discriminant (U_Type)))
then
Build_Mutable_Record_Read_Procedure
(Loc, Full_Base (U_Type), Decl, Pname);
else
Build_Record_Read_Procedure
(Loc, Full_Base (U_Type), Decl, Pname);
end if;
-- Suppress checks, uninitialized or otherwise invalid
-- data does not cause constraint errors to be raised for
-- a complete record read.
Insert_Action (N, Decl, All_Checks);
end if;
end if;
Rewrite_Stream_Proc_Call (Pname);
end Read;
---------
-- Ref --
---------
-- Ref is identical to To_Address, see To_Address for processing
---------------
-- Remainder --
---------------
-- Transforms 'Remainder into a call to the floating-point attribute
-- function Remainder in Fat_xxx (where xxx is the root type)
when Attribute_Remainder =>
Expand_Fpt_Attribute_RR (N);
------------
-- Result --
------------
-- Transform 'Result into reference to _Result formal. At the point
-- where a legal 'Result attribute is expanded, we know that we are in
-- the context of a _Postcondition function with a _Result parameter.
when Attribute_Result =>
Rewrite (N, Make_Identifier (Loc, Chars => Name_uResult));
Analyze_And_Resolve (N, Typ);
-----------
-- Round --
-----------
-- The handling of the Round attribute is quite delicate. The processing
-- in Sem_Attr introduced a conversion to universal real, reflecting the
-- semantics of Round, but we do not want anything to do with universal
-- real at runtime, since this corresponds to using floating-point
-- arithmetic.
-- What we have now is that the Etype of the Round attribute correctly
-- indicates the final result type. The operand of the Round is the
-- conversion to universal real, described above, and the operand of
-- this conversion is the actual operand of Round, which may be the
-- special case of a fixed point multiplication or division (Etype =
-- universal fixed)
-- The exapander will expand first the operand of the conversion, then
-- the conversion, and finally the round attribute itself, since we
-- always work inside out. But we cannot simply process naively in this
-- order. In the semantic world where universal fixed and real really
-- exist and have infinite precision, there is no problem, but in the
-- implementation world, where universal real is a floating-point type,
-- we would get the wrong result.
-- So the approach is as follows. First, when expanding a multiply or
-- divide whose type is universal fixed, we do nothing at all, instead
-- deferring the operation till later.
-- The actual processing is done in Expand_N_Type_Conversion which
-- handles the special case of Round by looking at its parent to see if
-- it is a Round attribute, and if it is, handling the conversion (or
-- its fixed multiply/divide child) in an appropriate manner.
-- This means that by the time we get to expanding the Round attribute
-- itself, the Round is nothing more than a type conversion (and will
-- often be a null type conversion), so we just replace it with the
-- appropriate conversion operation.
when Attribute_Round =>
Rewrite (N,
Convert_To (Etype (N), Relocate_Node (First (Exprs))));
Analyze_And_Resolve (N);
--------------
-- Rounding --
--------------
-- Transforms 'Rounding into a call to the floating-point attribute
-- function Rounding in Fat_xxx (where xxx is the root type)
when Attribute_Rounding =>
Expand_Fpt_Attribute_R (N);
------------------
-- Same_Storage --
------------------
when Attribute_Same_Storage => Same_Storage : declare
Loc : constant Source_Ptr := Sloc (N);
X : constant Node_Id := Prefix (N);
Y : constant Node_Id := First (Expressions (N));
-- The arguments
X_Addr, Y_Addr : Node_Id;
-- Rhe expressions for their addresses
X_Size, Y_Size : Node_Id;
-- Rhe expressions for their sizes
begin
-- The attribute is expanded as:
-- (X'address = Y'address)
-- and then (X'Size = Y'Size)
-- If both arguments have the same Etype the second conjunct can be
-- omitted.
X_Addr :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Address,
Prefix => New_Copy_Tree (X));
Y_Addr :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Address,
Prefix => New_Copy_Tree (Y));
X_Size :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Size,
Prefix => New_Copy_Tree (X));
Y_Size :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Size,
Prefix => New_Copy_Tree (Y));
if Etype (X) = Etype (Y) then
Rewrite (N,
(Make_Op_Eq (Loc,
Left_Opnd => X_Addr,
Right_Opnd => Y_Addr)));
else
Rewrite (N,
Make_Op_And (Loc,
Left_Opnd =>
Make_Op_Eq (Loc,
Left_Opnd => X_Addr,
Right_Opnd => Y_Addr),
Right_Opnd =>
Make_Op_Eq (Loc,
Left_Opnd => X_Size,
Right_Opnd => Y_Size)));
end if;
Analyze_And_Resolve (N, Standard_Boolean);
end Same_Storage;
-------------
-- Scaling --
-------------
-- Transforms 'Scaling into a call to the floating-point attribute
-- function Scaling in Fat_xxx (where xxx is the root type)
when Attribute_Scaling =>
Expand_Fpt_Attribute_RI (N);
-------------------------
-- Simple_Storage_Pool --
-------------------------
when Attribute_Simple_Storage_Pool =>
Rewrite (N,
Make_Type_Conversion (Loc,
Subtype_Mark => New_Reference_To (Etype (N), Loc),
Expression => New_Reference_To (Entity (N), Loc)));
Analyze_And_Resolve (N, Typ);
----------
-- Size --
----------
when Attribute_Size |
Attribute_Object_Size |
Attribute_Value_Size |
Attribute_VADS_Size => Size :
declare
Siz : Uint;
New_Node : Node_Id;
begin
-- Processing for VADS_Size case. Note that this processing removes
-- all traces of VADS_Size from the tree, and completes all required
-- processing for VADS_Size by translating the attribute reference
-- to an appropriate Size or Object_Size reference.
if Id = Attribute_VADS_Size
or else (Use_VADS_Size and then Id = Attribute_Size)
then
-- If the size is specified, then we simply use the specified
-- size. This applies to both types and objects. The size of an
-- object can be specified in the following ways:
-- An explicit size object is given for an object
-- A component size is specified for an indexed component
-- A component clause is specified for a selected component
-- The object is a component of a packed composite object
-- If the size is specified, then VADS_Size of an object
if (Is_Entity_Name (Pref)
and then Present (Size_Clause (Entity (Pref))))
or else
(Nkind (Pref) = N_Component_Clause
and then (Present (Component_Clause
(Entity (Selector_Name (Pref))))
or else Is_Packed (Etype (Prefix (Pref)))))
or else
(Nkind (Pref) = N_Indexed_Component
and then (Component_Size (Etype (Prefix (Pref))) /= 0
or else Is_Packed (Etype (Prefix (Pref)))))
then
Set_Attribute_Name (N, Name_Size);
-- Otherwise if we have an object rather than a type, then the
-- VADS_Size attribute applies to the type of the object, rather
-- than the object itself. This is one of the respects in which
-- VADS_Size differs from Size.
else
if (not Is_Entity_Name (Pref)
or else not Is_Type (Entity (Pref)))
and then (Is_Scalar_Type (Ptyp) or else Is_Constrained (Ptyp))
then
Rewrite (Pref, New_Occurrence_Of (Ptyp, Loc));
end if;
-- For a scalar type for which no size was explicitly given,
-- VADS_Size means Object_Size. This is the other respect in
-- which VADS_Size differs from Size.
if Is_Scalar_Type (Ptyp) and then No (Size_Clause (Ptyp)) then
Set_Attribute_Name (N, Name_Object_Size);
-- In all other cases, Size and VADS_Size are the sane
else
Set_Attribute_Name (N, Name_Size);
end if;
end if;
end if;
-- For class-wide types, X'Class'Size is transformed into a direct
-- reference to the Size of the class type, so that the back end does
-- not have to deal with the X'Class'Size reference.
if Is_Entity_Name (Pref)
and then Is_Class_Wide_Type (Entity (Pref))
then
Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
return;
-- For X'Size applied to an object of a class-wide type, transform
-- X'Size into a call to the primitive operation _Size applied to X.
elsif Is_Class_Wide_Type (Ptyp)
or else (Id = Attribute_Size
and then Is_Tagged_Type (Ptyp)
and then Has_Unknown_Discriminants (Ptyp))
then
-- No need to do anything else compiling under restriction
-- No_Dispatching_Calls. During the semantic analysis we
-- already notified such violation.
if Restriction_Active (No_Dispatching_Calls) then
return;
end if;
New_Node :=
Make_Function_Call (Loc,
Name => New_Reference_To
(Find_Prim_Op (Ptyp, Name_uSize), Loc),
Parameter_Associations => New_List (Pref));
if Typ /= Standard_Long_Long_Integer then
-- The context is a specific integer type with which the
-- original attribute was compatible. The function has a
-- specific type as well, so to preserve the compatibility
-- we must convert explicitly.
New_Node := Convert_To (Typ, New_Node);
end if;
Rewrite (N, New_Node);
Analyze_And_Resolve (N, Typ);
return;
-- Case of known RM_Size of a type
elsif (Id = Attribute_Size or else Id = Attribute_Value_Size)
and then Is_Entity_Name (Pref)
and then Is_Type (Entity (Pref))
and then Known_Static_RM_Size (Entity (Pref))
then
Siz := RM_Size (Entity (Pref));
-- Case of known Esize of a type
elsif Id = Attribute_Object_Size
and then Is_Entity_Name (Pref)
and then Is_Type (Entity (Pref))
and then Known_Static_Esize (Entity (Pref))
then
Siz := Esize (Entity (Pref));
-- Case of known size of object
elsif Id = Attribute_Size
and then Is_Entity_Name (Pref)
and then Is_Object (Entity (Pref))
and then Known_Esize (Entity (Pref))
and then Known_Static_Esize (Entity (Pref))
then
Siz := Esize (Entity (Pref));
-- For an array component, we can do Size in the front end
-- if the component_size of the array is set.
elsif Nkind (Pref) = N_Indexed_Component then
Siz := Component_Size (Etype (Prefix (Pref)));
-- For a record component, we can do Size in the front end if there
-- is a component clause, or if the record is packed and the
-- component's size is known at compile time.
elsif Nkind (Pref) = N_Selected_Component then
declare
Rec : constant Entity_Id := Etype (Prefix (Pref));
Comp : constant Entity_Id := Entity (Selector_Name (Pref));
begin
if Present (Component_Clause (Comp)) then
Siz := Esize (Comp);
elsif Is_Packed (Rec) then
Siz := RM_Size (Ptyp);
else
Apply_Universal_Integer_Attribute_Checks (N);
return;
end if;
end;
-- All other cases are handled by the back end
else
Apply_Universal_Integer_Attribute_Checks (N);
-- If Size is applied to a formal parameter that is of a packed
-- array subtype, then apply Size to the actual subtype.
if Is_Entity_Name (Pref)
and then Is_Formal (Entity (Pref))
and then Is_Array_Type (Ptyp)
and then Is_Packed (Ptyp)
then
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Get_Actual_Subtype (Pref), Loc),
Attribute_Name => Name_Size));
Analyze_And_Resolve (N, Typ);
end if;
-- If Size applies to a dereference of an access to unconstrained
-- packed array, the back end needs to see its unconstrained
-- nominal type, but also a hint to the actual constrained type.
if Nkind (Pref) = N_Explicit_Dereference
and then Is_Array_Type (Ptyp)
and then not Is_Constrained (Ptyp)
and then Is_Packed (Ptyp)
then
Set_Actual_Designated_Subtype (Pref,
Get_Actual_Subtype (Pref));
end if;
return;
end if;
-- Common processing for record and array component case
if Siz /= No_Uint and then Siz /= 0 then
declare
CS : constant Boolean := Comes_From_Source (N);
begin
Rewrite (N, Make_Integer_Literal (Loc, Siz));
-- This integer literal is not a static expression. We do not
-- call Analyze_And_Resolve here, because this would activate
-- the circuit for deciding that a static value was out of
-- range, and we don't want that.
-- So just manually set the type, mark the expression as non-
-- static, and then ensure that the result is checked properly
-- if the attribute comes from source (if it was internally
-- generated, we never need a constraint check).
Set_Etype (N, Typ);
Set_Is_Static_Expression (N, False);
if CS then
Apply_Constraint_Check (N, Typ);
end if;
end;
end if;
end Size;
------------------
-- Storage_Pool --
------------------
when Attribute_Storage_Pool =>
Rewrite (N,
Make_Type_Conversion (Loc,
Subtype_Mark => New_Reference_To (Etype (N), Loc),
Expression => New_Reference_To (Entity (N), Loc)));
Analyze_And_Resolve (N, Typ);
------------------
-- Storage_Size --
------------------
when Attribute_Storage_Size => Storage_Size : declare
Alloc_Op : Entity_Id := Empty;
begin
-- Access type case, always go to the root type
-- The case of access types results in a value of zero for the case
-- where no storage size attribute clause has been given. If a
-- storage size has been given, then the attribute is converted
-- to a reference to the variable used to hold this value.
if Is_Access_Type (Ptyp) then
if Present (Storage_Size_Variable (Root_Type (Ptyp))) then
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Typ, Loc),
Attribute_Name => Name_Max,
Expressions => New_List (
Make_Integer_Literal (Loc, 0),
Convert_To (Typ,
New_Reference_To
(Storage_Size_Variable (Root_Type (Ptyp)), Loc)))));
elsif Present (Associated_Storage_Pool (Root_Type (Ptyp))) then
-- If the access type is associated with a simple storage pool
-- object, then attempt to locate the optional Storage_Size
-- function of the simple storage pool type. If not found,
-- then the result will default to zero.
if Present (Get_Rep_Pragma (Root_Type (Ptyp),
Name_Simple_Storage_Pool_Type))
then
declare
Pool_Type : constant Entity_Id :=
Base_Type (Etype (Entity (N)));
begin
Alloc_Op := Get_Name_Entity_Id (Name_Storage_Size);
while Present (Alloc_Op) loop
if Scope (Alloc_Op) = Scope (Pool_Type)
and then Present (First_Formal (Alloc_Op))
and then Etype (First_Formal (Alloc_Op)) = Pool_Type
then
exit;
end if;
Alloc_Op := Homonym (Alloc_Op);
end loop;
end;
-- In the normal Storage_Pool case, retrieve the primitive
-- function associated with the pool type.
else
Alloc_Op :=
Find_Prim_Op
(Etype (Associated_Storage_Pool (Root_Type (Ptyp))),
Attribute_Name (N));
end if;
-- If Storage_Size wasn't found (can only occur in the simple
-- storage pool case), then simply use zero for the result.
if not Present (Alloc_Op) then
Rewrite (N, Make_Integer_Literal (Loc, 0));
-- Otherwise, rewrite the allocator as a call to pool type's
-- Storage_Size function.
else
Rewrite (N,
OK_Convert_To (Typ,
Make_Function_Call (Loc,
Name =>
New_Reference_To (Alloc_Op, Loc),
Parameter_Associations => New_List (
New_Reference_To
(Associated_Storage_Pool
(Root_Type (Ptyp)), Loc)))));
end if;
else
Rewrite (N, Make_Integer_Literal (Loc, 0));
end if;
Analyze_And_Resolve (N, Typ);
-- For tasks, we retrieve the size directly from the TCB. The
-- size may depend on a discriminant of the type, and therefore
-- can be a per-object expression, so type-level information is
-- not sufficient in general. There are four cases to consider:
-- a) If the attribute appears within a task body, the designated
-- TCB is obtained by a call to Self.
-- b) If the prefix of the attribute is the name of a task object,
-- the designated TCB is the one stored in the corresponding record.
-- c) If the prefix is a task type, the size is obtained from the
-- size variable created for each task type
-- d) If no storage_size was specified for the type , there is no
-- size variable, and the value is a system-specific default.
else
if In_Open_Scopes (Ptyp) then
-- Storage_Size (Self)
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
Parameter_Associations =>
New_List (
Make_Function_Call (Loc,
Name =>
New_Reference_To (RTE (RE_Self), Loc))))));
elsif not Is_Entity_Name (Pref)
or else not Is_Type (Entity (Pref))
then
-- Storage_Size (Rec (Obj).Size)
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
Parameter_Associations =>
New_List (
Make_Selected_Component (Loc,
Prefix =>
Unchecked_Convert_To (
Corresponding_Record_Type (Ptyp),
New_Copy_Tree (Pref)),
Selector_Name =>
Make_Identifier (Loc, Name_uTask_Id))))));
elsif Present (Storage_Size_Variable (Ptyp)) then
-- Static storage size pragma given for type: retrieve value
-- from its allocated storage variable.
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name => New_Occurrence_Of (
RTE (RE_Adjust_Storage_Size), Loc),
Parameter_Associations =>
New_List (
New_Reference_To (
Storage_Size_Variable (Ptyp), Loc)))));
else
-- Get system default
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (
RTE (RE_Default_Stack_Size), Loc))));
end if;
Analyze_And_Resolve (N, Typ);
end if;
end Storage_Size;
-----------------
-- Stream_Size --
-----------------
when Attribute_Stream_Size =>
Rewrite (N,
Make_Integer_Literal (Loc, Intval => Get_Stream_Size (Ptyp)));
Analyze_And_Resolve (N, Typ);
----------
-- Succ --
----------
-- 1. Deal with enumeration types with holes
-- 2. For floating-point, generate call to attribute function
-- 3. For other cases, deal with constraint checking
when Attribute_Succ => Succ : declare
Etyp : constant Entity_Id := Base_Type (Ptyp);
begin
-- For enumeration types with non-standard representations, we
-- expand typ'Succ (x) into
-- Pos_To_Rep (Rep_To_Pos (x) + 1)
-- If the representation is contiguous, we compute instead
-- Lit1 + Rep_to_Pos (x+1), to catch invalid representations.
if Is_Enumeration_Type (Ptyp)
and then Present (Enum_Pos_To_Rep (Etyp))
then
if Has_Contiguous_Rep (Etyp) then
Rewrite (N,
Unchecked_Convert_To (Ptyp,
Make_Op_Add (Loc,
Left_Opnd =>
Make_Integer_Literal (Loc,
Enumeration_Rep (First_Literal (Ptyp))),
Right_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To
(TSS (Etyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations =>
New_List (
Unchecked_Convert_To (Ptyp,
Make_Op_Add (Loc,
Left_Opnd =>
Unchecked_Convert_To (Standard_Integer,
Relocate_Node (First (Exprs))),
Right_Opnd =>
Make_Integer_Literal (Loc, 1))),
Rep_To_Pos_Flag (Ptyp, Loc))))));
else
-- Add Boolean parameter True, to request program errror if
-- we have a bad representation on our hands. Add False if
-- checks are suppressed.
Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
Rewrite (N,
Make_Indexed_Component (Loc,
Prefix =>
New_Reference_To
(Enum_Pos_To_Rep (Etyp), Loc),
Expressions => New_List (
Make_Op_Add (Loc,
Left_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To
(TSS (Etyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations => Exprs),
Right_Opnd => Make_Integer_Literal (Loc, 1)))));
end if;
Analyze_And_Resolve (N, Typ);
-- For floating-point, we transform 'Succ into a call to the Succ
-- floating-point attribute function in Fat_xxx (xxx is root type)
elsif Is_Floating_Point_Type (Ptyp) then
Expand_Fpt_Attribute_R (N);
Analyze_And_Resolve (N, Typ);
-- For modular types, nothing to do (no overflow, since wraps)
elsif Is_Modular_Integer_Type (Ptyp) then
null;
-- For other types, if argument is marked as needing a range check or
-- overflow checking is enabled, we must generate a check.
elsif not Overflow_Checks_Suppressed (Ptyp)
or else Do_Range_Check (First (Exprs))
then
Set_Do_Range_Check (First (Exprs), False);
Expand_Pred_Succ (N);
end if;
end Succ;
---------
-- Tag --
---------
-- Transforms X'Tag into a direct reference to the tag of X
when Attribute_Tag => Tag : declare
Ttyp : Entity_Id;
Prefix_Is_Type : Boolean;
begin
if Is_Entity_Name (Pref) and then Is_Type (Entity (Pref)) then
Ttyp := Entity (Pref);
Prefix_Is_Type := True;
else
Ttyp := Ptyp;
Prefix_Is_Type := False;
end if;
if Is_Class_Wide_Type (Ttyp) then
Ttyp := Root_Type (Ttyp);
end if;
Ttyp := Underlying_Type (Ttyp);
-- Ada 2005: The type may be a synchronized tagged type, in which
-- case the tag information is stored in the corresponding record.
if Is_Concurrent_Type (Ttyp) then
Ttyp := Corresponding_Record_Type (Ttyp);
end if;
if Prefix_Is_Type then
-- For VMs we leave the type attribute unexpanded because
-- there's not a dispatching table to reference.
if Tagged_Type_Expansion then
Rewrite (N,
Unchecked_Convert_To (RTE (RE_Tag),
New_Reference_To
(Node (First_Elmt (Access_Disp_Table (Ttyp))), Loc)));
Analyze_And_Resolve (N, RTE (RE_Tag));
end if;
-- Ada 2005 (AI-251): The use of 'Tag in the sources always
-- references the primary tag of the actual object. If 'Tag is
-- applied to class-wide interface objects we generate code that
-- displaces "this" to reference the base of the object.
elsif Comes_From_Source (N)
and then Is_Class_Wide_Type (Etype (Prefix (N)))
and then Is_Interface (Etype (Prefix (N)))
then
-- Generate:
-- (To_Tag_Ptr (Prefix'Address)).all
-- Note that Prefix'Address is recursively expanded into a call
-- to Base_Address (Obj.Tag)
-- Not needed for VM targets, since all handled by the VM
if Tagged_Type_Expansion then
Rewrite (N,
Make_Explicit_Dereference (Loc,
Unchecked_Convert_To (RTE (RE_Tag_Ptr),
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Pref),
Attribute_Name => Name_Address))));
Analyze_And_Resolve (N, RTE (RE_Tag));
end if;
else
Rewrite (N,
Make_Selected_Component (Loc,
Prefix => Relocate_Node (Pref),
Selector_Name =>
New_Reference_To (First_Tag_Component (Ttyp), Loc)));
Analyze_And_Resolve (N, RTE (RE_Tag));
end if;
end Tag;
----------------
-- Terminated --
----------------
-- Transforms 'Terminated attribute into a call to Terminated function
when Attribute_Terminated => Terminated :
begin
-- The prefix of Terminated is of a task interface class-wide type.
-- Generate:
-- terminated (Task_Id (Pref._disp_get_task_id));
if Ada_Version >= Ada_2005
and then Ekind (Ptyp) = E_Class_Wide_Type
and then Is_Interface (Ptyp)
and then Is_Task_Interface (Ptyp)
then
Rewrite (N,
Make_Function_Call (Loc,
Name =>
New_Reference_To (RTE (RE_Terminated), Loc),
Parameter_Associations => New_List (
Make_Unchecked_Type_Conversion (Loc,
Subtype_Mark =>
New_Reference_To (RTE (RO_ST_Task_Id), Loc),
Expression =>
Make_Selected_Component (Loc,
Prefix =>
New_Copy_Tree (Pref),
Selector_Name =>
Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
elsif Restricted_Profile then
Rewrite (N,
Build_Call_With_Task (Pref, RTE (RE_Restricted_Terminated)));
else
Rewrite (N,
Build_Call_With_Task (Pref, RTE (RE_Terminated)));
end if;
Analyze_And_Resolve (N, Standard_Boolean);
end Terminated;
----------------
-- To_Address --
----------------
-- Transforms System'To_Address (X) and System.Address'Ref (X) into
-- unchecked conversion from (integral) type of X to type address.
when Attribute_To_Address | Attribute_Ref =>
Rewrite (N,
Unchecked_Convert_To (RTE (RE_Address),
Relocate_Node (First (Exprs))));
Analyze_And_Resolve (N, RTE (RE_Address));
------------
-- To_Any --
------------
when Attribute_To_Any => To_Any : declare
P_Type : constant Entity_Id := Etype (Pref);
Decls : constant List_Id := New_List;
begin
Rewrite (N,
Build_To_Any_Call
(Loc,
Convert_To (P_Type,
Relocate_Node (First (Exprs))), Decls));
Insert_Actions (N, Decls);
Analyze_And_Resolve (N, RTE (RE_Any));
end To_Any;
----------------
-- Truncation --
----------------
-- Transforms 'Truncation into a call to the floating-point attribute
-- function Truncation in Fat_xxx (where xxx is the root type).
-- Expansion is avoided for cases the back end can handle directly.
when Attribute_Truncation =>
if not Is_Inline_Floating_Point_Attribute (N) then
Expand_Fpt_Attribute_R (N);
end if;
--------------
-- TypeCode --
--------------
when Attribute_TypeCode => TypeCode : declare
P_Type : constant Entity_Id := Etype (Pref);
Decls : constant List_Id := New_List;
begin
Rewrite (N, Build_TypeCode_Call (Loc, P_Type, Decls));
Insert_Actions (N, Decls);
Analyze_And_Resolve (N, RTE (RE_TypeCode));
end TypeCode;
-----------------------
-- Unbiased_Rounding --
-----------------------
-- Transforms 'Unbiased_Rounding into a call to the floating-point
-- attribute function Unbiased_Rounding in Fat_xxx (where xxx is the
-- root type). Expansion is avoided for cases the back end can handle
-- directly.
when Attribute_Unbiased_Rounding =>
if not Is_Inline_Floating_Point_Attribute (N) then
Expand_Fpt_Attribute_R (N);
end if;
-----------------
-- UET_Address --
-----------------
when Attribute_UET_Address => UET_Address : declare
Ent : constant Entity_Id := Make_Temporary (Loc, 'T');
begin
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Ent,
Aliased_Present => True,
Object_Definition =>
New_Occurrence_Of (RTE (RE_Address), Loc)));
-- Construct name __gnat_xxx__SDP, where xxx is the unit name
-- in normal external form.
Get_External_Unit_Name_String (Get_Unit_Name (Pref));
Name_Buffer (1 + 7 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
Name_Len := Name_Len + 7;
Name_Buffer (1 .. 7) := "__gnat_";
Name_Buffer (Name_Len + 1 .. Name_Len + 5) := "__SDP";
Name_Len := Name_Len + 5;
Set_Is_Imported (Ent);
Set_Interface_Name (Ent,
Make_String_Literal (Loc,
Strval => String_From_Name_Buffer));
-- Set entity as internal to ensure proper Sprint output of its
-- implicit importation.
Set_Is_Internal (Ent);
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ent, Loc),
Attribute_Name => Name_Address));
Analyze_And_Resolve (N, Typ);
end UET_Address;
------------
-- Update --
------------
when Attribute_Update =>
Expand_Update_Attribute (N);
---------------
-- VADS_Size --
---------------
-- The processing for VADS_Size is shared with Size
---------
-- Val --
---------
-- For enumeration types with a standard representation, and for all
-- other types, Val is handled by the back end. For enumeration types
-- with a non-standard representation we use the _Pos_To_Rep array that
-- was created when the type was frozen.
when Attribute_Val => Val : declare
Etyp : constant Entity_Id := Base_Type (Entity (Pref));
begin
if Is_Enumeration_Type (Etyp)
and then Present (Enum_Pos_To_Rep (Etyp))
then
if Has_Contiguous_Rep (Etyp) then
declare
Rep_Node : constant Node_Id :=
Unchecked_Convert_To (Etyp,
Make_Op_Add (Loc,
Left_Opnd =>
Make_Integer_Literal (Loc,
Enumeration_Rep (First_Literal (Etyp))),
Right_Opnd =>
(Convert_To (Standard_Integer,
Relocate_Node (First (Exprs))))));
begin
Rewrite (N,
Unchecked_Convert_To (Etyp,
Make_Op_Add (Loc,
Left_Opnd =>
Make_Integer_Literal (Loc,
Enumeration_Rep (First_Literal (Etyp))),
Right_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To
(TSS (Etyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations => New_List (
Rep_Node,
Rep_To_Pos_Flag (Etyp, Loc))))));
end;
else
Rewrite (N,
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (Enum_Pos_To_Rep (Etyp), Loc),
Expressions => New_List (
Convert_To (Standard_Integer,
Relocate_Node (First (Exprs))))));
end if;
Analyze_And_Resolve (N, Typ);
-- If the argument is marked as requiring a range check then generate
-- it here.
elsif Do_Range_Check (First (Exprs)) then
Set_Do_Range_Check (First (Exprs), False);
Generate_Range_Check (First (Exprs), Etyp, CE_Range_Check_Failed);
end if;
end Val;
-----------
-- Valid --
-----------
-- The code for valid is dependent on the particular types involved.
-- See separate sections below for the generated code in each case.
when Attribute_Valid => Valid : declare
Btyp : Entity_Id := Base_Type (Ptyp);
Tst : Node_Id;
Save_Validity_Checks_On : constant Boolean := Validity_Checks_On;
-- Save the validity checking mode. We always turn off validity
-- checking during process of 'Valid since this is one place
-- where we do not want the implicit validity checks to intefere
-- with the explicit validity check that the programmer is doing.
function Make_Range_Test return Node_Id;
-- Build the code for a range test of the form
-- Btyp!(Pref) in Btyp!(Ptyp'First) .. Btyp!(Ptyp'Last)
---------------------
-- Make_Range_Test --
---------------------
function Make_Range_Test return Node_Id is
Temp : constant Node_Id := Duplicate_Subexpr (Pref);
begin
-- The value whose validity is being checked has been captured in
-- an object declaration. We certainly don't want this object to
-- appear valid because the declaration initializes it!
if Is_Entity_Name (Temp) then
Set_Is_Known_Valid (Entity (Temp), False);
end if;
return
Make_In (Loc,
Left_Opnd =>
Unchecked_Convert_To (Btyp, Temp),
Right_Opnd =>
Make_Range (Loc,
Low_Bound =>
Unchecked_Convert_To (Btyp,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Attribute_Name => Name_First)),
High_Bound =>
Unchecked_Convert_To (Btyp,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Attribute_Name => Name_Last))));
end Make_Range_Test;
-- Start of processing for Attribute_Valid
begin
-- Do not expand sourced code 'Valid reference in CodePeer mode,
-- will be handled by the back-end directly.
if CodePeer_Mode and then Comes_From_Source (N) then
return;
end if;
-- Turn off validity checks. We do not want any implicit validity
-- checks to intefere with the explicit check from the attribute
Validity_Checks_On := False;
-- Retrieve the base type. Handle the case where the base type is a
-- private enumeration type.
if Is_Private_Type (Btyp) and then Present (Full_View (Btyp)) then
Btyp := Full_View (Btyp);
end if;
-- Floating-point case. This case is handled by the Valid attribute
-- code in the floating-point attribute run-time library.
if Is_Floating_Point_Type (Ptyp) then
declare
Pkg : RE_Id;
Ftp : Entity_Id;
begin
case Float_Rep (Btyp) is
-- For vax fpt types, call appropriate routine in special
-- vax floating point unit. No need to worry about loads in
-- this case, since these types have no signalling NaN's.
when VAX_Native => Expand_Vax_Valid (N);
-- The AAMP back end handles Valid for floating-point types
when AAMP =>
Analyze_And_Resolve (Pref, Ptyp);
Set_Etype (N, Standard_Boolean);
Set_Analyzed (N);
when IEEE_Binary =>
Find_Fat_Info (Ptyp, Ftp, Pkg);
-- If the floating-point object might be unaligned, we
-- need to call the special routine Unaligned_Valid,
-- which makes the needed copy, being careful not to
-- load the value into any floating-point register.
-- The argument in this case is obj'Address (see
-- Unaligned_Valid routine in Fat_Gen).
if Is_Possibly_Unaligned_Object (Pref) then
Expand_Fpt_Attribute
(N, Pkg, Name_Unaligned_Valid,
New_List (
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Pref),
Attribute_Name => Name_Address)));
-- In the normal case where we are sure the object is
-- aligned, we generate a call to Valid, and the argument
-- in this case is obj'Unrestricted_Access (after
-- converting obj to the right floating-point type).
else
Expand_Fpt_Attribute
(N, Pkg, Name_Valid,
New_List (
Make_Attribute_Reference (Loc,
Prefix => Unchecked_Convert_To (Ftp, Pref),
Attribute_Name => Name_Unrestricted_Access)));
end if;
end case;
-- One more task, we still need a range check. Required
-- only if we have a constraint, since the Valid routine
-- catches infinities properly (infinities are never valid).
-- The way we do the range check is simply to create the
-- expression: Valid (N) and then Base_Type(Pref) in Typ.
if not Subtypes_Statically_Match (Ptyp, Btyp) then
Rewrite (N,
Make_And_Then (Loc,
Left_Opnd => Relocate_Node (N),
Right_Opnd =>
Make_In (Loc,
Left_Opnd => Convert_To (Btyp, Pref),
Right_Opnd => New_Occurrence_Of (Ptyp, Loc))));
end if;
end;
-- Enumeration type with holes
-- For enumeration types with holes, the Pos value constructed by
-- the Enum_Rep_To_Pos function built in Exp_Ch3 called with a
-- second argument of False returns minus one for an invalid value,
-- and the non-negative pos value for a valid value, so the
-- expansion of X'Valid is simply:
-- type(X)'Pos (X) >= 0
-- We can't quite generate it that way because of the requirement
-- for the non-standard second argument of False in the resulting
-- rep_to_pos call, so we have to explicitly create:
-- _rep_to_pos (X, False) >= 0
-- If we have an enumeration subtype, we also check that the
-- value is in range:
-- _rep_to_pos (X, False) >= 0
-- and then
-- (X >= type(X)'First and then type(X)'Last <= X)
elsif Is_Enumeration_Type (Ptyp)
and then Present (Enum_Pos_To_Rep (Btyp))
then
Tst :=
Make_Op_Ge (Loc,
Left_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To (TSS (Btyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations => New_List (
Pref,
New_Occurrence_Of (Standard_False, Loc))),
Right_Opnd => Make_Integer_Literal (Loc, 0));
if Ptyp /= Btyp
and then
(Type_Low_Bound (Ptyp) /= Type_Low_Bound (Btyp)
or else
Type_High_Bound (Ptyp) /= Type_High_Bound (Btyp))
then
-- The call to Make_Range_Test will create declarations
-- that need a proper insertion point, but Pref is now
-- attached to a node with no ancestor. Attach to tree
-- even if it is to be rewritten below.
Set_Parent (Tst, Parent (N));
Tst :=
Make_And_Then (Loc,
Left_Opnd => Make_Range_Test,
Right_Opnd => Tst);
end if;
Rewrite (N, Tst);
-- Fortran convention booleans
-- For the very special case of Fortran convention booleans, the
-- value is always valid, since it is an integer with the semantics
-- that non-zero is true, and any value is permissible.
elsif Is_Boolean_Type (Ptyp)
and then Convention (Ptyp) = Convention_Fortran
then
Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
-- For biased representations, we will be doing an unchecked
-- conversion without unbiasing the result. That means that the range
-- test has to take this into account, and the proper form of the
-- test is:
-- Btyp!(Pref) < Btyp!(Ptyp'Range_Length)
elsif Has_Biased_Representation (Ptyp) then
Btyp := RTE (RE_Unsigned_32);
Rewrite (N,
Make_Op_Lt (Loc,
Left_Opnd =>
Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)),
Right_Opnd =>
Unchecked_Convert_To (Btyp,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Attribute_Name => Name_Range_Length))));
-- For all other scalar types, what we want logically is a
-- range test:
-- X in type(X)'First .. type(X)'Last
-- But that's precisely what won't work because of possible
-- unwanted optimization (and indeed the basic motivation for
-- the Valid attribute is exactly that this test does not work!)
-- What will work is:
-- Btyp!(X) >= Btyp!(type(X)'First)
-- and then
-- Btyp!(X) <= Btyp!(type(X)'Last)
-- where Btyp is an integer type large enough to cover the full
-- range of possible stored values (i.e. it is chosen on the basis
-- of the size of the type, not the range of the values). We write
-- this as two tests, rather than a range check, so that static
-- evaluation will easily remove either or both of the checks if
-- they can be -statically determined to be true (this happens
-- when the type of X is static and the range extends to the full
-- range of stored values).
-- Unsigned types. Note: it is safe to consider only whether the
-- subtype is unsigned, since we will in that case be doing all
-- unsigned comparisons based on the subtype range. Since we use the
-- actual subtype object size, this is appropriate.
-- For example, if we have
-- subtype x is integer range 1 .. 200;
-- for x'Object_Size use 8;
-- Now the base type is signed, but objects of this type are bits
-- unsigned, and doing an unsigned test of the range 1 to 200 is
-- correct, even though a value greater than 127 looks signed to a
-- signed comparison.
elsif Is_Unsigned_Type (Ptyp) then
if Esize (Ptyp) <= 32 then
Btyp := RTE (RE_Unsigned_32);
else
Btyp := RTE (RE_Unsigned_64);
end if;
Rewrite (N, Make_Range_Test);
-- Signed types
else
if Esize (Ptyp) <= Esize (Standard_Integer) then
Btyp := Standard_Integer;
else
Btyp := Universal_Integer;
end if;
Rewrite (N, Make_Range_Test);
end if;
-- If a predicate is present, then we do the predicate test, even if
-- within the predicate function (infinite recursion is warned about
-- in Sem_Attr in that case).
declare
Pred_Func : constant Entity_Id := Predicate_Function (Ptyp);
begin
if Present (Pred_Func) then
Rewrite (N,
Make_And_Then (Loc,
Left_Opnd => Relocate_Node (N),
Right_Opnd => Make_Predicate_Call (Ptyp, Pref)));
end if;
end;
Analyze_And_Resolve (N, Standard_Boolean);
Validity_Checks_On := Save_Validity_Checks_On;
end Valid;
-------------------
-- Valid_Scalars --
-------------------
when Attribute_Valid_Scalars => Valid_Scalars : declare
Ftyp : Entity_Id;
begin
if Present (Underlying_Type (Ptyp)) then
Ftyp := Underlying_Type (Ptyp);
else
Ftyp := Ptyp;
end if;
-- For scalar types, Valid_Scalars is the same as Valid
if Is_Scalar_Type (Ftyp) then
Rewrite (N,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Valid,
Prefix => Pref));
Analyze_And_Resolve (N, Standard_Boolean);
-- For array types, we construct a function that determines if there
-- are any non-valid scalar subcomponents, and call the function.
-- We only do this for arrays whose component type needs checking
elsif Is_Array_Type (Ftyp)
and then not No_Scalar_Parts (Component_Type (Ftyp))
then
Rewrite (N,
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (Build_Array_VS_Func (Ftyp, N), Loc),
Parameter_Associations => New_List (Pref)));
Analyze_And_Resolve (N, Standard_Boolean);
-- For record types, we build a big if expression, applying Valid or
-- Valid_Scalars as appropriate to all relevant components.
elsif (Is_Record_Type (Ptyp) or else Has_Discriminants (Ptyp))
and then not No_Scalar_Parts (Ptyp)
then
declare
C : Entity_Id;
X : Node_Id;
A : Name_Id;
begin
X := New_Occurrence_Of (Standard_True, Loc);
C := First_Component_Or_Discriminant (Ptyp);
while Present (C) loop
if No_Scalar_Parts (Etype (C)) then
goto Continue;
elsif Is_Scalar_Type (Etype (C)) then
A := Name_Valid;
else
A := Name_Valid_Scalars;
end if;
X :=
Make_And_Then (Loc,
Left_Opnd => X,
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => A,
Prefix =>
Make_Selected_Component (Loc,
Prefix =>
Duplicate_Subexpr (Pref, Name_Req => True),
Selector_Name =>
New_Occurrence_Of (C, Loc))));
<<Continue>>
Next_Component_Or_Discriminant (C);
end loop;
Rewrite (N, X);
Analyze_And_Resolve (N, Standard_Boolean);
end;
-- For all other types, result is True (but not static)
else
Rewrite (N, New_Occurrence_Of (Standard_Boolean, Loc));
Analyze_And_Resolve (N, Standard_Boolean);
Set_Is_Static_Expression (N, False);
end if;
end Valid_Scalars;
-----------
-- Value --
-----------
-- Value attribute is handled in separate unit Exp_Imgv
when Attribute_Value =>
Exp_Imgv.Expand_Value_Attribute (N);
-----------------
-- Value_Size --
-----------------
-- The processing for Value_Size shares the processing for Size
-------------
-- Version --
-------------
-- The processing for Version shares the processing for Body_Version
----------------
-- Wide_Image --
----------------
-- Wide_Image attribute is handled in separate unit Exp_Imgv
when Attribute_Wide_Image =>
Exp_Imgv.Expand_Wide_Image_Attribute (N);
---------------------
-- Wide_Wide_Image --
---------------------
-- Wide_Wide_Image attribute is handled in separate unit Exp_Imgv
when Attribute_Wide_Wide_Image =>
Exp_Imgv.Expand_Wide_Wide_Image_Attribute (N);
----------------
-- Wide_Value --
----------------
-- We expand typ'Wide_Value (X) into
-- typ'Value
-- (Wide_String_To_String (X, Wide_Character_Encoding_Method))
-- Wide_String_To_String is a runtime function that converts its wide
-- string argument to String, converting any non-translatable characters
-- into appropriate escape sequences. This preserves the required
-- semantics of Wide_Value in all cases, and results in a very simple
-- implementation approach.
-- Note: for this approach to be fully standard compliant for the cases
-- where typ is Wide_Character and Wide_Wide_Character, the encoding
-- method must cover the entire character range (e.g. UTF-8). But that
-- is a reasonable requirement when dealing with encoded character
-- sequences. Presumably if one of the restrictive encoding mechanisms
-- is in use such as Shift-JIS, then characters that cannot be
-- represented using this encoding will not appear in any case.
when Attribute_Wide_Value => Wide_Value :
begin
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => Pref,
Attribute_Name => Name_Value,
Expressions => New_List (
Make_Function_Call (Loc,
Name =>
New_Reference_To (RTE (RE_Wide_String_To_String), Loc),
Parameter_Associations => New_List (
Relocate_Node (First (Exprs)),
Make_Integer_Literal (Loc,
Intval => Int (Wide_Character_Encoding_Method)))))));
Analyze_And_Resolve (N, Typ);
end Wide_Value;
---------------------
-- Wide_Wide_Value --
---------------------
-- We expand typ'Wide_Value_Value (X) into
-- typ'Value
-- (Wide_Wide_String_To_String (X, Wide_Character_Encoding_Method))
-- Wide_Wide_String_To_String is a runtime function that converts its
-- wide string argument to String, converting any non-translatable
-- characters into appropriate escape sequences. This preserves the
-- required semantics of Wide_Wide_Value in all cases, and results in a
-- very simple implementation approach.
-- It's not quite right where typ = Wide_Wide_Character, because the
-- encoding method may not cover the whole character type ???
when Attribute_Wide_Wide_Value => Wide_Wide_Value :
begin
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => Pref,
Attribute_Name => Name_Value,
Expressions => New_List (
Make_Function_Call (Loc,
Name =>
New_Reference_To (RTE (RE_Wide_Wide_String_To_String), Loc),
Parameter_Associations => New_List (
Relocate_Node (First (Exprs)),
Make_Integer_Literal (Loc,
Intval => Int (Wide_Character_Encoding_Method)))))));
Analyze_And_Resolve (N, Typ);
end Wide_Wide_Value;
---------------------
-- Wide_Wide_Width --
---------------------
-- Wide_Wide_Width attribute is handled in separate unit Exp_Imgv
when Attribute_Wide_Wide_Width =>
Exp_Imgv.Expand_Width_Attribute (N, Wide_Wide);
----------------
-- Wide_Width --
----------------
-- Wide_Width attribute is handled in separate unit Exp_Imgv
when Attribute_Wide_Width =>
Exp_Imgv.Expand_Width_Attribute (N, Wide);
-----------
-- Width --
-----------
-- Width attribute is handled in separate unit Exp_Imgv
when Attribute_Width =>
Exp_Imgv.Expand_Width_Attribute (N, Normal);
-----------
-- Write --
-----------
when Attribute_Write => Write : declare
P_Type : constant Entity_Id := Entity (Pref);
U_Type : constant Entity_Id := Underlying_Type (P_Type);
Pname : Entity_Id;
Decl : Node_Id;
Prag : Node_Id;
Arg3 : Node_Id;
Wfunc : Node_Id;
begin
-- If no underlying type, we have an error that will be diagnosed
-- elsewhere, so here we just completely ignore the expansion.
if No (U_Type) then
return;
end if;
-- The simple case, if there is a TSS for Write, just call it
Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Write);
if Present (Pname) then
null;
else
-- If there is a Stream_Convert pragma, use it, we rewrite
-- sourcetyp'Output (stream, Item)
-- as
-- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
-- where strmwrite is the given Write function that converts an
-- argument of type sourcetyp or a type acctyp, from which it is
-- derived to type strmtyp. The conversion to acttyp is required
-- for the derived case.
Prag := Get_Stream_Convert_Pragma (P_Type);
if Present (Prag) then
Arg3 :=
Next (Next (First (Pragma_Argument_Associations (Prag))));
Wfunc := Entity (Expression (Arg3));
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
Attribute_Name => Name_Output,
Expressions => New_List (
Relocate_Node (First (Exprs)),
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Wfunc, Loc),
Parameter_Associations => New_List (
OK_Convert_To (Etype (First_Formal (Wfunc)),
Relocate_Node (Next (First (Exprs)))))))));
Analyze (N);
return;
-- For elementary types, we call the W_xxx routine directly
elsif Is_Elementary_Type (U_Type) then
Rewrite (N, Build_Elementary_Write_Call (N));
Analyze (N);
return;
-- Array type case
elsif Is_Array_Type (U_Type) then
Build_Array_Write_Procedure (N, U_Type, Decl, Pname);
Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
-- Tagged type case, use the primitive Write function. Note that
-- this will dispatch in the class-wide case which is what we want
elsif Is_Tagged_Type (U_Type) then
Pname := Find_Prim_Op (U_Type, TSS_Stream_Write);
-- All other record type cases, including protected records.
-- The latter only arise for expander generated code for
-- handling shared passive partition access.
else
pragma Assert
(Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
-- Ada 2005 (AI-216): Program_Error is raised when executing
-- the default implementation of the Write attribute of an
-- Unchecked_Union type. However, if the 'Write reference is
-- within the generated Output stream procedure, Write outputs
-- the components, and the default values of the discriminant
-- are streamed by the Output procedure itself.
if Is_Unchecked_Union (Base_Type (U_Type))
and not Is_TSS (Current_Scope, TSS_Stream_Output)
then
Insert_Action (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction));
end if;
if Has_Discriminants (U_Type)
and then Present
(Discriminant_Default_Value (First_Discriminant (U_Type)))
then
Build_Mutable_Record_Write_Procedure
(Loc, Full_Base (U_Type), Decl, Pname);
else
Build_Record_Write_Procedure
(Loc, Full_Base (U_Type), Decl, Pname);
end if;
Insert_Action (N, Decl);
end if;
end if;
-- If we fall through, Pname is the procedure to be called
Rewrite_Stream_Proc_Call (Pname);
end Write;
-- Component_Size is handled by the back end, unless the component size
-- is known at compile time, which is always true in the packed array
-- case. It is important that the packed array case is handled in the
-- front end (see Eval_Attribute) since the back end would otherwise get
-- confused by the equivalent packed array type.
when Attribute_Component_Size =>
null;
-- The following attributes are handled by the back end (except that
-- static cases have already been evaluated during semantic processing,
-- but in any case the back end should not count on this). The one bit
-- of special processing required is that these attributes typically
-- generate conditionals in the code, so we need to check the relevant
-- restriction.
when Attribute_Max |
Attribute_Min =>
Check_Restriction (No_Implicit_Conditionals, N);
-- The following attributes are handled by the back end (except that
-- static cases have already been evaluated during semantic processing,
-- but in any case the back end should not count on this).
-- The back end also handles the non-class-wide cases of Size
when Attribute_Bit_Order |
Attribute_Code_Address |
Attribute_Definite |
Attribute_Null_Parameter |
Attribute_Passed_By_Reference |
Attribute_Pool_Address |
Attribute_Scalar_Storage_Order =>
null;
-- The following attributes are also handled by the back end, but return
-- a universal integer result, so may need a conversion for checking
-- that the result is in range.
when Attribute_Aft |
Attribute_Max_Alignment_For_Allocation =>
Apply_Universal_Integer_Attribute_Checks (N);
-- The following attributes should not appear at this stage, since they
-- have already been handled by the analyzer (and properly rewritten
-- with corresponding values or entities to represent the right values)
when Attribute_Abort_Signal |
Attribute_Address_Size |
Attribute_Atomic_Always_Lock_Free |
Attribute_Base |
Attribute_Class |
Attribute_Compiler_Version |
Attribute_Default_Bit_Order |
Attribute_Delta |
Attribute_Denorm |
Attribute_Digits |
Attribute_Emax |
Attribute_Enabled |
Attribute_Epsilon |
Attribute_Fast_Math |
Attribute_First_Valid |
Attribute_Has_Access_Values |
Attribute_Has_Discriminants |
Attribute_Has_Tagged_Values |
Attribute_Large |
Attribute_Last_Valid |
Attribute_Lock_Free |
Attribute_Machine_Emax |
Attribute_Machine_Emin |
Attribute_Machine_Mantissa |
Attribute_Machine_Overflows |
Attribute_Machine_Radix |
Attribute_Machine_Rounds |
Attribute_Maximum_Alignment |
Attribute_Model_Emin |
Attribute_Model_Epsilon |
Attribute_Model_Mantissa |
Attribute_Model_Small |
Attribute_Modulus |
Attribute_Partition_ID |
Attribute_Range |
Attribute_Safe_Emax |
Attribute_Safe_First |
Attribute_Safe_Large |
Attribute_Safe_Last |
Attribute_Safe_Small |
Attribute_Scale |
Attribute_Signed_Zeros |
Attribute_Small |
Attribute_Storage_Unit |
Attribute_Stub_Type |
Attribute_System_Allocator_Alignment |
Attribute_Target_Name |
Attribute_Type_Class |
Attribute_Type_Key |
Attribute_Unconstrained_Array |
Attribute_Universal_Literal_String |
Attribute_Wchar_T_Size |
Attribute_Word_Size =>
raise Program_Error;
-- The Asm_Input and Asm_Output attributes are not expanded at this
-- stage, but will be eliminated in the expansion of the Asm call, see
-- Exp_Intr for details. So the back end will never see these either.
when Attribute_Asm_Input |
Attribute_Asm_Output =>
null;
end case;
-- Note: as mentioned earlier, individual sections of the above case
-- statement assume there is no code after the case statement, and are
-- legitimately allowed to execute return statements if they have nothing
-- more to do, so DO NOT add code at this point.
exception
when RE_Not_Available =>
return;
end Expand_N_Attribute_Reference;
----------------------
-- Expand_Pred_Succ --
----------------------
-- For typ'Pred (exp), we generate the check
-- [constraint_error when exp = typ'Base'First]
-- Similarly, for typ'Succ (exp), we generate the check
-- [constraint_error when exp = typ'Base'Last]
-- These checks are not generated for modular types, since the proper
-- semantics for Succ and Pred on modular types is to wrap, not raise CE.
-- We also suppress these checks if we are the right side of an assignment
-- statement or the expression of an object declaration, where the flag
-- Suppress_Assignment_Checks is set for the assignment/declaration.
procedure Expand_Pred_Succ (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
P : constant Node_Id := Parent (N);
Cnam : Name_Id;
begin
if Attribute_Name (N) = Name_Pred then
Cnam := Name_First;
else
Cnam := Name_Last;
end if;
if not Nkind_In (P, N_Assignment_Statement, N_Object_Declaration)
or else not Suppress_Assignment_Checks (P)
then
Insert_Action (N,
Make_Raise_Constraint_Error (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd =>
Duplicate_Subexpr_Move_Checks (First (Expressions (N))),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix =>
New_Reference_To (Base_Type (Etype (Prefix (N))), Loc),
Attribute_Name => Cnam)),
Reason => CE_Overflow_Check_Failed));
end if;
end Expand_Pred_Succ;
-----------------------------
-- Expand_Update_Attribute --
-----------------------------
procedure Expand_Update_Attribute (N : Node_Id) is
procedure Process_Component_Or_Element_Update
(Temp : Entity_Id;
Comp : Node_Id;
Expr : Node_Id;
Typ : Entity_Id);
-- Generate the statements necessary to update a single component or an
-- element of the prefix. The code is inserted before the attribute N.
-- Temp denotes the entity of the anonymous object created to reflect
-- the changes in values. Comp is the component/index expression to be
-- updated. Expr is an expression yielding the new value of Comp. Typ
-- is the type of the prefix of attribute Update.
procedure Process_Range_Update
(Temp : Entity_Id;
Comp : Node_Id;
Expr : Node_Id);
-- Generate the statements necessary to update a slice of the prefix.
-- The code is inserted before the attribute N. Temp denotes the entity
-- of the anonymous object created to reflect the changes in values.
-- Comp is range of the slice to be updated. Expr is an expression
-- yielding the new value of Comp.
-----------------------------------------
-- Process_Component_Or_Element_Update --
-----------------------------------------
procedure Process_Component_Or_Element_Update
(Temp : Entity_Id;
Comp : Node_Id;
Expr : Node_Id;
Typ : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (Comp);
Exprs : List_Id;
LHS : Node_Id;
begin
-- An array element may be modified by the following relations
-- depending on the number of dimensions:
-- 1 => Expr -- one dimensional update
-- (1, ..., N) => Expr -- multi dimensional update
-- The above forms are converted in assignment statements where the
-- left hand side is an indexed component:
-- Temp (1) := Expr; -- one dimensional update
-- Temp (1, ..., N) := Expr; -- multi dimensional update
if Is_Array_Type (Typ) then
-- The index expressions of a multi dimensional array update
-- appear as an aggregate.
if Nkind (Comp) = N_Aggregate then
Exprs := New_Copy_List_Tree (Expressions (Comp));
else
Exprs := New_List (Relocate_Node (Comp));
end if;
LHS :=
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (Temp, Loc),
Expressions => Exprs);
-- A record component update appears in the following form:
-- Comp => Expr
-- The above relation is transformed into an assignment statement
-- where the left hand side is a selected component:
-- Temp.Comp := Expr;
else pragma Assert (Is_Record_Type (Typ));
LHS :=
Make_Selected_Component (Loc,
Prefix => New_Reference_To (Temp, Loc),
Selector_Name => Relocate_Node (Comp));
end if;
Insert_Action (N,
Make_Assignment_Statement (Loc,
Name => LHS,
Expression => Relocate_Node (Expr)));
end Process_Component_Or_Element_Update;
--------------------------
-- Process_Range_Update --
--------------------------
procedure Process_Range_Update
(Temp : Entity_Id;
Comp : Node_Id;
Expr : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Comp);
Index : Entity_Id;
begin
-- A range update appears as
-- (Low .. High => Expr)
-- The above construct is transformed into a loop that iterates over
-- the given range and modifies the corresponding array values to the
-- value of Expr:
-- for Index in Low .. High loop
-- Temp (Index) := Expr;
-- end loop;
Index := Make_Temporary (Loc, 'I');
Insert_Action (N,
Make_Loop_Statement (Loc,
Iteration_Scheme =>
Make_Iteration_Scheme (Loc,
Loop_Parameter_Specification =>
Make_Loop_Parameter_Specification (Loc,
Defining_Identifier => Index,
Discrete_Subtype_Definition => Relocate_Node (Comp))),
Statements => New_List (
Make_Assignment_Statement (Loc,
Name =>
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (Temp, Loc),
Expressions => New_List (New_Reference_To (Index, Loc))),
Expression => Relocate_Node (Expr))),
End_Label => Empty));
end Process_Range_Update;
-- Local variables
Aggr : constant Node_Id := First (Expressions (N));
Loc : constant Source_Ptr := Sloc (N);
Pref : constant Node_Id := Prefix (N);
Typ : constant Entity_Id := Etype (Pref);
Assoc : Node_Id;
Comp : Node_Id;
Expr : Node_Id;
Temp : Entity_Id;
-- Start of processing for Expand_Update_Attribute
begin
-- Create the anonymous object that stores the value of the prefix and
-- reflects subsequent changes in value. Generate:
-- Temp : <type of Pref> := Pref;
Temp := Make_Temporary (Loc, 'T');
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition => New_Reference_To (Typ, Loc),
Expression => Relocate_Node (Pref)));
-- Process the update aggregate
Assoc := First (Component_Associations (Aggr));
while Present (Assoc) loop
Comp := First (Choices (Assoc));
Expr := Expression (Assoc);
while Present (Comp) loop
if Nkind (Comp) = N_Range then
Process_Range_Update (Temp, Comp, Expr);
else
Process_Component_Or_Element_Update (Temp, Comp, Expr, Typ);
end if;
Next (Comp);
end loop;
Next (Assoc);
end loop;
-- The attribute is replaced by a reference to the anonymous object
Rewrite (N, New_Reference_To (Temp, Loc));
Analyze (N);
end Expand_Update_Attribute;
-------------------
-- Find_Fat_Info --
-------------------
procedure Find_Fat_Info
(T : Entity_Id;
Fat_Type : out Entity_Id;
Fat_Pkg : out RE_Id)
is
Btyp : constant Entity_Id := Base_Type (T);
Rtyp : constant Entity_Id := Root_Type (T);
Digs : constant Nat := UI_To_Int (Digits_Value (Btyp));
begin
-- If the base type is VAX float, then get appropriate VAX float type
if Vax_Float (Btyp) then
case Digs is
when 6 =>
Fat_Type := RTE (RE_Fat_VAX_F);
Fat_Pkg := RE_Attr_VAX_F_Float;
when 9 =>
Fat_Type := RTE (RE_Fat_VAX_D);
Fat_Pkg := RE_Attr_VAX_D_Float;
when 15 =>
Fat_Type := RTE (RE_Fat_VAX_G);
Fat_Pkg := RE_Attr_VAX_G_Float;
when others =>
raise Program_Error;
end case;
-- If root type is VAX float, this is the case where the library has
-- been recompiled in VAX float mode, and we have an IEEE float type.
-- This is when we use the special IEEE Fat packages.
elsif Vax_Float (Rtyp) then
case Digs is
when 6 =>
Fat_Type := RTE (RE_Fat_IEEE_Short);
Fat_Pkg := RE_Attr_IEEE_Short;
when 15 =>
Fat_Type := RTE (RE_Fat_IEEE_Long);
Fat_Pkg := RE_Attr_IEEE_Long;
when others =>
raise Program_Error;
end case;
-- If neither the base type nor the root type is VAX_Native then VAX
-- float is out of the picture, and we can just use the root type.
else
Fat_Type := Rtyp;
if Fat_Type = Standard_Short_Float then
Fat_Pkg := RE_Attr_Short_Float;
elsif Fat_Type = Standard_Float then
Fat_Pkg := RE_Attr_Float;
elsif Fat_Type = Standard_Long_Float then
Fat_Pkg := RE_Attr_Long_Float;
elsif Fat_Type = Standard_Long_Long_Float then
Fat_Pkg := RE_Attr_Long_Long_Float;
-- Universal real (which is its own root type) is treated as being
-- equivalent to Standard.Long_Long_Float, since it is defined to
-- have the same precision as the longest Float type.
elsif Fat_Type = Universal_Real then
Fat_Type := Standard_Long_Long_Float;
Fat_Pkg := RE_Attr_Long_Long_Float;
else
raise Program_Error;
end if;
end if;
end Find_Fat_Info;
----------------------------
-- Find_Stream_Subprogram --
----------------------------
function Find_Stream_Subprogram
(Typ : Entity_Id;
Nam : TSS_Name_Type) return Entity_Id
is
Base_Typ : constant Entity_Id := Base_Type (Typ);
Ent : constant Entity_Id := TSS (Typ, Nam);
function Is_Available (Entity : RE_Id) return Boolean;
pragma Inline (Is_Available);
-- Function to check whether the specified run-time call is available
-- in the run time used. In the case of a configurable run time, it
-- is normal that some subprograms are not there.
-- I don't understand this routine at all, why is this not just a
-- call to RTE_Available? And if for some reason we need a different
-- routine with different semantics, why is not in Rtsfind ???
------------------
-- Is_Available --
------------------
function Is_Available (Entity : RE_Id) return Boolean is
begin
-- Assume that the unit will always be available when using a
-- "normal" (not configurable) run time.
return not Configurable_Run_Time_Mode
or else RTE_Available (Entity);
end Is_Available;
-- Start of processing for Find_Stream_Subprogram
begin
if Present (Ent) then
return Ent;
end if;
-- Stream attributes for strings are expanded into library calls. The
-- following checks are disabled when the run-time is not available or
-- when compiling predefined types due to bootstrap issues. As a result,
-- the compiler will generate in-place stream routines for string types
-- that appear in GNAT's library, but will generate calls via rtsfind
-- to library routines for user code.
-- ??? For now, disable this code for JVM, since this generates a
-- VerifyError exception at run time on e.g. c330001.
-- This is disabled for AAMP, to avoid creating dependences on files not
-- supported in the AAMP library (such as s-fileio.adb).
-- Note: In the case of using a configurable run time, it is very likely
-- that stream routines for string types are not present (they require
-- file system support). In this case, the specific stream routines for
-- strings are not used, relying on the regular stream mechanism
-- instead. That is why we include the test Is_Available when dealing
-- with these cases.
if VM_Target /= JVM_Target
and then not AAMP_On_Target
and then
not Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
then
-- String as defined in package Ada
if Base_Typ = Standard_String then
if Restriction_Active (No_Stream_Optimizations) then
if Nam = TSS_Stream_Input
and then Is_Available (RE_String_Input)
then
return RTE (RE_String_Input);
elsif Nam = TSS_Stream_Output
and then Is_Available (RE_String_Output)
then
return RTE (RE_String_Output);
elsif Nam = TSS_Stream_Read
and then Is_Available (RE_String_Read)
then
return RTE (RE_String_Read);
elsif Nam = TSS_Stream_Write
and then Is_Available (RE_String_Write)
then
return RTE (RE_String_Write);
elsif Nam /= TSS_Stream_Input and then
Nam /= TSS_Stream_Output and then
Nam /= TSS_Stream_Read and then
Nam /= TSS_Stream_Write
then
raise Program_Error;
end if;
else
if Nam = TSS_Stream_Input
and then Is_Available (RE_String_Input_Blk_IO)
then
return RTE (RE_String_Input_Blk_IO);
elsif Nam = TSS_Stream_Output
and then Is_Available (RE_String_Output_Blk_IO)
then
return RTE (RE_String_Output_Blk_IO);
elsif Nam = TSS_Stream_Read
and then Is_Available (RE_String_Read_Blk_IO)
then
return RTE (RE_String_Read_Blk_IO);
elsif Nam = TSS_Stream_Write
and then Is_Available (RE_String_Write_Blk_IO)
then
return RTE (RE_String_Write_Blk_IO);
elsif Nam /= TSS_Stream_Input and then
Nam /= TSS_Stream_Output and then
Nam /= TSS_Stream_Read and then
Nam /= TSS_Stream_Write
then
raise Program_Error;
end if;
end if;
-- Wide_String as defined in package Ada
elsif Base_Typ = Standard_Wide_String then
if Restriction_Active (No_Stream_Optimizations) then
if Nam = TSS_Stream_Input
and then Is_Available (RE_Wide_String_Input)
then
return RTE (RE_Wide_String_Input);
elsif Nam = TSS_Stream_Output
and then Is_Available (RE_Wide_String_Output)
then
return RTE (RE_Wide_String_Output);
elsif Nam = TSS_Stream_Read
and then Is_Available (RE_Wide_String_Read)
then
return RTE (RE_Wide_String_Read);
elsif Nam = TSS_Stream_Write
and then Is_Available (RE_Wide_String_Write)
then
return RTE (RE_Wide_String_Write);
elsif Nam /= TSS_Stream_Input and then
Nam /= TSS_Stream_Output and then
Nam /= TSS_Stream_Read and then
Nam /= TSS_Stream_Write
then
raise Program_Error;
end if;
else
if Nam = TSS_Stream_Input
and then Is_Available (RE_Wide_String_Input_Blk_IO)
then
return RTE (RE_Wide_String_Input_Blk_IO);
elsif Nam = TSS_Stream_Output
and then Is_Available (RE_Wide_String_Output_Blk_IO)
then
return RTE (RE_Wide_String_Output_Blk_IO);
elsif Nam = TSS_Stream_Read
and then Is_Available (RE_Wide_String_Read_Blk_IO)
then
return RTE (RE_Wide_String_Read_Blk_IO);
elsif Nam = TSS_Stream_Write
and then Is_Available (RE_Wide_String_Write_Blk_IO)
then
return RTE (RE_Wide_String_Write_Blk_IO);
elsif Nam /= TSS_Stream_Input and then
Nam /= TSS_Stream_Output and then
Nam /= TSS_Stream_Read and then
Nam /= TSS_Stream_Write
then
raise Program_Error;
end if;
end if;
-- Wide_Wide_String as defined in package Ada
elsif Base_Typ = Standard_Wide_Wide_String then
if Restriction_Active (No_Stream_Optimizations) then
if Nam = TSS_Stream_Input
and then Is_Available (RE_Wide_Wide_String_Input)
then
return RTE (RE_Wide_Wide_String_Input);
elsif Nam = TSS_Stream_Output
and then Is_Available (RE_Wide_Wide_String_Output)
then
return RTE (RE_Wide_Wide_String_Output);
elsif Nam = TSS_Stream_Read
and then Is_Available (RE_Wide_Wide_String_Read)
then
return RTE (RE_Wide_Wide_String_Read);
elsif Nam = TSS_Stream_Write
and then Is_Available (RE_Wide_Wide_String_Write)
then
return RTE (RE_Wide_Wide_String_Write);
elsif Nam /= TSS_Stream_Input and then
Nam /= TSS_Stream_Output and then
Nam /= TSS_Stream_Read and then
Nam /= TSS_Stream_Write
then
raise Program_Error;
end if;
else
if Nam = TSS_Stream_Input
and then Is_Available (RE_Wide_Wide_String_Input_Blk_IO)
then
return RTE (RE_Wide_Wide_String_Input_Blk_IO);
elsif Nam = TSS_Stream_Output
and then Is_Available (RE_Wide_Wide_String_Output_Blk_IO)
then
return RTE (RE_Wide_Wide_String_Output_Blk_IO);
elsif Nam = TSS_Stream_Read
and then Is_Available (RE_Wide_Wide_String_Read_Blk_IO)
then
return RTE (RE_Wide_Wide_String_Read_Blk_IO);
elsif Nam = TSS_Stream_Write
and then Is_Available (RE_Wide_Wide_String_Write_Blk_IO)
then
return RTE (RE_Wide_Wide_String_Write_Blk_IO);
elsif Nam /= TSS_Stream_Input and then
Nam /= TSS_Stream_Output and then
Nam /= TSS_Stream_Read and then
Nam /= TSS_Stream_Write
then
raise Program_Error;
end if;
end if;
end if;
end if;
if Is_Tagged_Type (Typ)
and then Is_Derived_Type (Typ)
then
return Find_Prim_Op (Typ, Nam);
else
return Find_Inherited_TSS (Typ, Nam);
end if;
end Find_Stream_Subprogram;
---------------
-- Full_Base --
---------------
function Full_Base (T : Entity_Id) return Entity_Id is
BT : Entity_Id;
begin
BT := Base_Type (T);
if Is_Private_Type (BT)
and then Present (Full_View (BT))
then
BT := Full_View (BT);
end if;
return BT;
end Full_Base;
-----------------------
-- Get_Index_Subtype --
-----------------------
function Get_Index_Subtype (N : Node_Id) return Node_Id is
P_Type : Entity_Id := Etype (Prefix (N));
Indx : Node_Id;
J : Int;
begin
if Is_Access_Type (P_Type) then
P_Type := Designated_Type (P_Type);
end if;
if No (Expressions (N)) then
J := 1;
else
J := UI_To_Int (Expr_Value (First (Expressions (N))));
end if;
Indx := First_Index (P_Type);
while J > 1 loop
Next_Index (Indx);
J := J - 1;
end loop;
return Etype (Indx);
end Get_Index_Subtype;
-------------------------------
-- Get_Stream_Convert_Pragma --
-------------------------------
function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id is
Typ : Entity_Id;
N : Node_Id;
begin
-- Note: we cannot use Get_Rep_Pragma here because of the peculiarity
-- that a stream convert pragma for a tagged type is not inherited from
-- its parent. Probably what is wrong here is that it is basically
-- incorrect to consider a stream convert pragma to be a representation
-- pragma at all ???
N := First_Rep_Item (Implementation_Base_Type (T));
while Present (N) loop
if Nkind (N) = N_Pragma
and then Pragma_Name (N) = Name_Stream_Convert
then
-- For tagged types this pragma is not inherited, so we
-- must verify that it is defined for the given type and
-- not an ancestor.
Typ :=
Entity (Expression (First (Pragma_Argument_Associations (N))));
if not Is_Tagged_Type (T)
or else T = Typ
or else (Is_Private_Type (Typ) and then T = Full_View (Typ))
then
return N;
end if;
end if;
Next_Rep_Item (N);
end loop;
return Empty;
end Get_Stream_Convert_Pragma;
---------------------------------
-- Is_Constrained_Packed_Array --
---------------------------------
function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean is
Arr : Entity_Id := Typ;
begin
if Is_Access_Type (Arr) then
Arr := Designated_Type (Arr);
end if;
return Is_Array_Type (Arr)
and then Is_Constrained (Arr)
and then Present (Packed_Array_Type (Arr));
end Is_Constrained_Packed_Array;
----------------------------------------
-- Is_Inline_Floating_Point_Attribute --
----------------------------------------
function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean is
Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
begin
if Nkind (Parent (N)) /= N_Type_Conversion
or else not Is_Integer_Type (Etype (Parent (N)))
then
return False;
end if;
-- Should also support 'Machine_Rounding and 'Unbiased_Rounding, but
-- required back end support has not been implemented yet ???
return Id = Attribute_Truncation;
end Is_Inline_Floating_Point_Attribute;
end Exp_Attr;