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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ A T T R --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Aspects; use Aspects;
with Atree; use Atree;
with 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 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.
function Build_Record_VS_Func
(R_Type : Entity_Id;
Nod : Node_Id) return Entity_Id;
-- Build function to test Valid_Scalars for record 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.
-- If we are within an instance body all visibility has been established
-- already and there is no need to install the package.
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_Loop_Entry_Attribute (N : Node_Id);
-- Handle the expansion of attribute 'Loop_Entry. As a result, the related
-- loop may be converted into a conditional block. See body for details.
procedure Expand_Min_Max_Attribute (N : Node_Id);
-- Handle the expansion of attributes 'Max and 'Min, including expanding
-- then out if we are in Modify_Tree_For_C mode.
procedure Expand_Pred_Succ_Attribute (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);
Func_Id : constant Entity_Id := Make_Temporary (Loc, 'V');
Comp_Type : constant Entity_Id := Component_Type (A_Type);
Body_Stmts : List_Id;
Index_List : List_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_Occurrence_Of (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;
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_Occurrence_Of (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;
Set_Is_Pure (Func_Id);
return Func_Id;
end Build_Array_VS_Func;
--------------------------
-- Build_Record_VS_Func --
--------------------------
-- Generates:
-- function _Valid_Scalars (X : T) return Boolean is
-- begin
-- -- Check discriminants
-- if not X.D1'Valid_Scalars or else
-- not X.D2'Valid_Scalars or else
-- ...
-- then
-- return False;
-- end if;
-- -- Check components
-- if not X.C1'Valid_Scalars or else
-- not X.C2'Valid_Scalars or else
-- ...
-- then
-- return False;
-- end if;
-- -- Check variant part
-- case X.D1 is
-- when V1 =>
-- if not X.C2'Valid_Scalars or else
-- not X.C3'Valid_Scalars or else
-- ...
-- then
-- return False;
-- end if;
-- ...
-- when Vn =>
-- if not X.Cn'Valid_Scalars or else
-- ...
-- then
-- return False;
-- end if;
-- end case;
-- return True;
-- end _Valid_Scalars;
function Build_Record_VS_Func
(R_Type : Entity_Id;
Nod : Node_Id) return Entity_Id
is
Loc : constant Source_Ptr := Sloc (R_Type);
Func_Id : constant Entity_Id := Make_Temporary (Loc, 'V');
X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_X);
function Make_VS_Case
(E : Entity_Id;
CL : Node_Id;
Discrs : Elist_Id := New_Elmt_List) return List_Id;
-- Building block for variant valid scalars. Given a Component_List node
-- CL, it generates an 'if' followed by a 'case' statement that compares
-- all components of local temporaries named X and Y (that are declared
-- as formals at some upper level). E provides the Sloc to be used for
-- the generated code.
function Make_VS_If
(E : Entity_Id;
L : List_Id) return Node_Id;
-- Building block for variant validate scalars. Given the list, L, of
-- components (or discriminants) L, it generates a return statement that
-- compares all components of local temporaries named X and Y (that are
-- declared as formals at some upper level). E provides the Sloc to be
-- used for the generated code.
------------------
-- Make_VS_Case --
------------------
-- <Make_VS_If on shared components>
-- case X.D1 is
-- when V1 => <Make_VS_Case> on subcomponents
-- ...
-- when Vn => <Make_VS_Case> on subcomponents
-- end case;
function Make_VS_Case
(E : Entity_Id;
CL : Node_Id;
Discrs : Elist_Id := New_Elmt_List) return List_Id
is
Loc : constant Source_Ptr := Sloc (E);
Result : constant List_Id := New_List;
Variant : Node_Id;
Alt_List : List_Id;
begin
Append_To (Result, Make_VS_If (E, Component_Items (CL)));
if No (Variant_Part (CL)) then
return Result;
end if;
Variant := First_Non_Pragma (Variants (Variant_Part (CL)));
if No (Variant) then
return Result;
end if;
Alt_List := New_List;
while Present (Variant) loop
Append_To (Alt_List,
Make_Case_Statement_Alternative (Loc,
Discrete_Choices => New_Copy_List (Discrete_Choices (Variant)),
Statements =>
Make_VS_Case (E, Component_List (Variant), Discrs)));
Next_Non_Pragma (Variant);
end loop;
Append_To (Result,
Make_Case_Statement (Loc,
Expression =>
Make_Selected_Component (Loc,
Prefix => Make_Identifier (Loc, Name_X),
Selector_Name => New_Copy (Name (Variant_Part (CL)))),
Alternatives => Alt_List));
return Result;
end Make_VS_Case;
----------------
-- Make_VS_If --
----------------
-- Generates:
-- if
-- not X.C1'Valid_Scalars
-- or else
-- not X.C2'Valid_Scalars
-- ...
-- then
-- return False;
-- end if;
-- or a null statement if the list L is empty
function Make_VS_If
(E : Entity_Id;
L : List_Id) return Node_Id
is
Loc : constant Source_Ptr := Sloc (E);
C : Node_Id;
Def_Id : Entity_Id;
Field_Name : Name_Id;
Cond : Node_Id;
begin
if No (L) then
return Make_Null_Statement (Loc);
else
Cond := Empty;
C := First_Non_Pragma (L);
while Present (C) loop
Def_Id := Defining_Identifier (C);
Field_Name := Chars (Def_Id);
-- The tags need not be checked since they will always be valid
-- Note also that in the following, we use Make_Identifier for
-- the component names. Use of New_Occurrence_Of to identify
-- the components would be incorrect because wrong entities for
-- discriminants could be picked up in the private type case.
-- Don't bother with abstract parent in interface case
if Field_Name = Name_uParent
and then Is_Interface (Etype (Def_Id))
then
null;
-- Don't bother with tag, always valid, and not scalar anyway
elsif Field_Name = Name_uTag then
null;
-- Don't bother with component with no scalar components
elsif not Scalar_Part_Present (Etype (Def_Id)) then
null;
-- Normal case, generate Valid_Scalars attribute reference
else
Evolve_Or_Else (Cond,
Make_Op_Not (Loc,
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix =>
Make_Identifier (Loc, Name_X),
Selector_Name =>
Make_Identifier (Loc, Field_Name)),
Attribute_Name => Name_Valid_Scalars)));
end if;
Next_Non_Pragma (C);
end loop;
if No (Cond) then
return Make_Null_Statement (Loc);
else
return
Make_Implicit_If_Statement (E,
Condition => Cond,
Then_Statements => New_List (
Make_Simple_Return_Statement (Loc,
Expression =>
New_Occurrence_Of (Standard_False, Loc))));
end if;
end if;
end Make_VS_If;
-- Local Declarations
Def : constant Node_Id := Parent (R_Type);
Comps : constant Node_Id := Component_List (Type_Definition (Def));
Stmts : constant List_Id := New_List;
Pspecs : constant List_Id := New_List;
begin
Append_To (Pspecs,
Make_Parameter_Specification (Loc,
Defining_Identifier => X,
Parameter_Type => New_Occurrence_Of (R_Type, Loc)));
Append_To (Stmts,
Make_VS_If (R_Type, Discriminant_Specifications (Def)));
Append_List_To (Stmts, Make_VS_Case (R_Type, Comps));
Append_To (Stmts,
Make_Simple_Return_Statement (Loc,
Expression => New_Occurrence_Of (Standard_True, Loc)));
Insert_Action (Nod,
Make_Subprogram_Body (Loc,
Specification =>
Make_Function_Specification (Loc,
Defining_Unit_Name => Func_Id,
Parameter_Specifications => Pspecs,
Result_Definition => New_Occurrence_Of (Standard_Boolean, Loc)),
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts)),
Suppress => Discriminant_Check);
if not Debug_Generated_Code then
Set_Debug_Info_Off (Func_Id);
end if;
Set_Is_Pure (Func_Id);
return Func_Id;
end Build_Record_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
-- If we are within an instance body, then all visibility has been
-- established already and there is no need to install the package.
and then not In_Instance_Body
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;
-- 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
-- All indirect calls are external calls, so must do locking and
-- barrier reevaluation, even if the 'Access occurs within the
-- protected body. Hence the call to External_Subprogram, as opposed
-- to Protected_Body_Subprogram, below. See RM-9.5(5). This means
-- that indirect calls from within the same protected body will
-- deadlock, as allowed by RM-9.5.1(8,15,17).
Sub := New_Occurrence_Of (External_Subprogram (Entity (Pref)), Loc);
-- 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_Occurrence_Of (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));
E2 : constant Node_Id := Next (E1);
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)),
Unchecked_Convert_To (Ftp, Relocate_Node (E2))));
end Expand_Fpt_Attribute_RR;
---------------------------------
-- Expand_Loop_Entry_Attribute --
---------------------------------
procedure Expand_Loop_Entry_Attribute (N : Node_Id) is
procedure Build_Conditional_Block
(Loc : Source_Ptr;
Cond : Node_Id;
Loop_Stmt : Node_Id;
If_Stmt : out Node_Id;
Blk_Stmt : out Node_Id);
-- Create a block Blk_Stmt with an empty declarative list and a single
-- loop Loop_Stmt. The block is encased in an if statement If_Stmt with
-- condition Cond. If_Stmt is Empty when there is no condition provided.
function Is_Array_Iteration (N : Node_Id) return Boolean;
-- Determine whether loop statement N denotes an Ada 2012 iteration over
-- an array object.
-----------------------------
-- Build_Conditional_Block --
-----------------------------
procedure Build_Conditional_Block
(Loc : Source_Ptr;
Cond : Node_Id;
Loop_Stmt : Node_Id;
If_Stmt : out Node_Id;
Blk_Stmt : out Node_Id)
is
begin
-- Do not reanalyze the original loop statement because it is simply
-- being relocated.
Set_Analyzed (Loop_Stmt);
Blk_Stmt :=
Make_Block_Statement (Loc,
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Loop_Stmt)));
if Present (Cond) then
If_Stmt :=
Make_If_Statement (Loc,
Condition => Cond,
Then_Statements => New_List (Blk_Stmt));
else
If_Stmt := Empty;
end if;
end Build_Conditional_Block;
------------------------
-- Is_Array_Iteration --
------------------------
function Is_Array_Iteration (N : Node_Id) return Boolean is
Stmt : constant Node_Id := Original_Node (N);
Iter : Node_Id;
begin
if Nkind (Stmt) = N_Loop_Statement
and then Present (Iteration_Scheme (Stmt))
and then Present (Iterator_Specification (Iteration_Scheme (Stmt)))
then
Iter := Iterator_Specification (Iteration_Scheme (Stmt));
return
Of_Present (Iter) and then Is_Array_Type (Etype (Name (Iter)));
end if;
return False;
end Is_Array_Iteration;
-- Local variables
Exprs : constant List_Id := Expressions (N);
Pref : constant Node_Id := Prefix (N);
Typ : constant Entity_Id := Etype (Pref);
Blk : Node_Id;
CW_Decl : Node_Id;
CW_Temp : Entity_Id;
CW_Typ : Entity_Id;
Decls : List_Id;
Installed : Boolean;
Loc : Source_Ptr;
Loop_Id : Entity_Id;
Loop_Stmt : Node_Id;
Result : Node_Id;
Scheme : Node_Id;
Temp_Decl : Node_Id;
Temp_Id : Entity_Id;
-- Start of processing for Expand_Loop_Entry_Attribute
begin
-- Step 1: Find the related loop
-- The loop label variant of attribute 'Loop_Entry already has all the
-- information in its expression.
if Present (Exprs) then
Loop_Id := Entity (First (Exprs));
Loop_Stmt := Label_Construct (Parent (Loop_Id));
-- Climb the parent chain to find the nearest enclosing loop. Skip all
-- internally generated loops for quantified expressions.
else
Loop_Stmt := N;
while Present (Loop_Stmt) loop
if Nkind (Loop_Stmt) = N_Loop_Statement
and then Present (Identifier (Loop_Stmt))
then
exit;
end if;
Loop_Stmt := Parent (Loop_Stmt);
end loop;
Loop_Id := Entity (Identifier (Loop_Stmt));
end if;
Loc := Sloc (Loop_Stmt);
-- Step 2: Transform the loop
-- The loop has already been transformed during the expansion of a prior
-- 'Loop_Entry attribute. Retrieve the declarative list of the block.
if Has_Loop_Entry_Attributes (Loop_Id) then
-- When the related loop name appears as the argument of attribute
-- Loop_Entry, the corresponding label construct is the generated
-- block statement. This is because the expander reuses the label.
if Nkind (Loop_Stmt) = N_Block_Statement then
Decls := Declarations (Loop_Stmt);
-- In all other cases, the loop must appear in the handled sequence
-- of statements of the generated block.
else
pragma Assert
(Nkind (Parent (Loop_Stmt)) = N_Handled_Sequence_Of_Statements
and then
Nkind (Parent (Parent (Loop_Stmt))) = N_Block_Statement);
Decls := Declarations (Parent (Parent (Loop_Stmt)));
end if;
Result := Empty;
-- Transform the loop into a conditional block
else
Set_Has_Loop_Entry_Attributes (Loop_Id);
Scheme := Iteration_Scheme (Loop_Stmt);
-- Infinite loops are transformed into:
-- declare
-- Temp1 : constant <type of Pref1> := <Pref1>;
-- . . .
-- TempN : constant <type of PrefN> := <PrefN>;
-- begin
-- loop
-- <original source statements with attribute rewrites>
-- end loop;
-- end;
if No (Scheme) then
Build_Conditional_Block (Loc,
Cond => Empty,
Loop_Stmt => Relocate_Node (Loop_Stmt),
If_Stmt => Result,
Blk_Stmt => Blk);
Result := Blk;
-- While loops are transformed into:
-- function Fnn return Boolean is
-- begin
-- <condition actions>
-- return <condition>;
-- end Fnn;
-- if Fnn then
-- declare
-- Temp1 : constant <type of Pref1> := <Pref1>;
-- . . .
-- TempN : constant <type of PrefN> := <PrefN>;
-- begin
-- loop
-- <original source statements with attribute rewrites>
-- exit when not Fnn;
-- end loop;
-- end;
-- end if;
-- Note that loops over iterators and containers are already
-- converted into while loops.
elsif Present (Condition (Scheme)) then
declare
Func_Decl : Node_Id;
Func_Id : Entity_Id;
Stmts : List_Id;
begin
-- Wrap the condition of the while loop in a Boolean function.
-- This avoids the duplication of the same code which may lead
-- to gigi issues with respect to multiple declaration of the
-- same entity in the presence of side effects or checks. Note
-- that the condition actions must also be relocated to the
-- wrapping function.
-- Generate:
-- <condition actions>
-- return <condition>;
if Present (Condition_Actions (Scheme)) then
Stmts := Condition_Actions (Scheme);
else
Stmts := New_List;
end if;
Append_To (Stmts,
Make_Simple_Return_Statement (Loc,
Expression => Relocate_Node (Condition (Scheme))));
-- Generate:
-- function Fnn return Boolean is
-- begin
-- <Stmts>
-- end Fnn;
Func_Id := Make_Temporary (Loc, 'F');
Func_Decl :=
Make_Subprogram_Body (Loc,
Specification =>
Make_Function_Specification (Loc,
Defining_Unit_Name => Func_Id,
Result_Definition =>
New_Occurrence_Of (Standard_Boolean, Loc)),
Declarations => Empty_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stmts));
-- The function is inserted before the related loop. Make sure
-- to analyze it in the context of the loop's enclosing scope.
Push_Scope (Scope (Loop_Id));
Insert_Action (Loop_Stmt, Func_Decl);
Pop_Scope;
-- Transform the original while loop into an infinite loop
-- where the last statement checks the negated condition. This
-- placement ensures that the condition will not be evaluated
-- twice on the first iteration.
Set_Iteration_Scheme (Loop_Stmt, Empty);
Scheme := Empty;
-- Generate:
-- exit when not Fnn;
Append_To (Statements (Loop_Stmt),
Make_Exit_Statement (Loc,
Condition =>
Make_Op_Not (Loc,
Right_Opnd =>
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Func_Id, Loc)))));
Build_Conditional_Block (Loc,
Cond =>
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Func_Id, Loc)),
Loop_Stmt => Relocate_Node (Loop_Stmt),
If_Stmt => Result,
Blk_Stmt => Blk);
end;
-- Ada 2012 iteration over an array is transformed into:
-- if <Array_Nam>'Length (1) > 0
-- and then <Array_Nam>'Length (N) > 0
-- then
-- declare
-- Temp1 : constant <type of Pref1> := <Pref1>;
-- . . .
-- TempN : constant <type of PrefN> := <PrefN>;
-- begin
-- for X in ... loop -- multiple loops depending on dims
-- <original source statements with attribute rewrites>
-- end loop;
-- end;
-- end if;
elsif Is_Array_Iteration (Loop_Stmt) then
declare
Array_Nam : constant Entity_Id :=
Entity (Name (Iterator_Specification
(Iteration_Scheme (Original_Node (Loop_Stmt)))));
Num_Dims : constant Pos :=
Number_Dimensions (Etype (Array_Nam));
Cond : Node_Id := Empty;
Check : Node_Id;
begin
-- Generate a check which determines whether all dimensions of
-- the array are non-null.
for Dim in 1 .. Num_Dims loop
Check :=
Make_Op_Gt (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Array_Nam, Loc),
Attribute_Name => Name_Length,
Expressions => New_List (
Make_Integer_Literal (Loc, Dim))),
Right_Opnd =>
Make_Integer_Literal (Loc, 0));
if No (Cond) then
Cond := Check;
else
Cond :=
Make_And_Then (Loc,
Left_Opnd => Cond,
Right_Opnd => Check);
end if;
end loop;
Build_Conditional_Block (Loc,
Cond => Cond,
Loop_Stmt => Relocate_Node (Loop_Stmt),
If_Stmt => Result,
Blk_Stmt => Blk);
end;
-- For loops are transformed into:
-- if <Low> <= <High> then
-- declare
-- Temp1 : constant <type of Pref1> := <Pref1>;
-- . . .
-- TempN : constant <type of PrefN> := <PrefN>;
-- begin
-- for <Def_Id> in <Low> .. <High> loop
-- <original source statements with attribute rewrites>
-- end loop;
-- end;
-- end if;
elsif Present (Loop_Parameter_Specification (Scheme)) then
declare
Loop_Spec : constant Node_Id :=
Loop_Parameter_Specification (Scheme);
Cond : Node_Id;
Subt_Def : Node_Id;
begin
Subt_Def := Discrete_Subtype_Definition (Loop_Spec);
-- When the loop iterates over a subtype indication with a
-- range, use the low and high bounds of the subtype itself.
if Nkind (Subt_Def) = N_Subtype_Indication then
Subt_Def := Scalar_Range (Etype (Subt_Def));
end if;
pragma Assert (Nkind (Subt_Def) = N_Range);
-- Generate
-- Low <= High
Cond :=
Make_Op_Le (Loc,
Left_Opnd => New_Copy_Tree (Low_Bound (Subt_Def)),
Right_Opnd => New_Copy_Tree (High_Bound (Subt_Def)));
Build_Conditional_Block (Loc,
Cond => Cond,
Loop_Stmt => Relocate_Node (Loop_Stmt),
If_Stmt => Result,
Blk_Stmt => Blk);
end;
end if;
Decls := Declarations (Blk);
end if;
-- Step 3: Create a constant to capture the value of the prefix at the
-- entry point into the loop.
Temp_Id := Make_Temporary (Loc, 'P');
-- Preserve the tag of the prefix by offering a specific view of the
-- class-wide version of the prefix.
if Is_Tagged_Type (Typ) then
-- Generate:
-- CW_Temp : constant Typ'Class := Typ'Class (Pref);
CW_Temp := Make_Temporary (Loc, 'T');
CW_Typ := Class_Wide_Type (Typ);
CW_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => CW_Temp,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (CW_Typ, Loc),
Expression =>
Convert_To (CW_Typ, Relocate_Node (Pref)));
Append_To (Decls, CW_Decl);
-- Generate:
-- Temp : Typ renames Typ (CW_Temp);
Temp_Decl :=
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Temp_Id,
Subtype_Mark => New_Occurrence_Of (Typ, Loc),
Name =>
Convert_To (Typ, New_Occurrence_Of (CW_Temp, Loc)));
Append_To (Decls, Temp_Decl);
-- Non-tagged case
else
CW_Decl := Empty;
-- Generate:
-- Temp : constant Typ := Pref;
Temp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp_Id,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (Typ, Loc),
Expression => Relocate_Node (Pref));
Append_To (Decls, Temp_Decl);
end if;
-- Step 4: Analyze all bits
Installed := Current_Scope = Scope (Loop_Id);
-- Depending on the pracement of attribute 'Loop_Entry relative to the
-- associated loop, ensure the proper visibility for analysis.
if not Installed then
Push_Scope (Scope (Loop_Id));
end if;
-- The analysis of the conditional block takes care of the constant
-- declaration.
if Present (Result) then
Rewrite (Loop_Stmt, Result);
Analyze (Loop_Stmt);
-- The conditional block was analyzed when a previous 'Loop_Entry was
-- expanded. There is no point in reanalyzing the block, simply analyze
-- the declaration of the constant.
else
if Present (CW_Decl) then
Analyze (CW_Decl);
end if;
Analyze (Temp_Decl);
end if;
Rewrite (N, New_Occurrence_Of (Temp_Id, Loc));
Analyze (N);
if not Installed then
Pop_Scope;
end if;
end Expand_Loop_Entry_Attribute;
------------------------------
-- Expand_Min_Max_Attribute --
------------------------------
procedure Expand_Min_Max_Attribute (N : Node_Id) is
begin
-- Min and Max are handled by the back end (except that static cases
-- have already been evaluated during semantic processing, although the
-- back end should not count on this). The one bit of special processing
-- required in the normal case is that these two attributes typically
-- generate conditionals in the code, so check the relevant restriction.
Check_Restriction (No_Implicit_Conditionals, N);
-- In Modify_Tree_For_C mode, we rewrite as an if expression
if Modify_Tree_For_C then
declare
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Expr : constant Node_Id := First (Expressions (N));
Left : constant Node_Id := Relocate_Node (Expr);
Right : constant Node_Id := Relocate_Node (Next (Expr));
function Make_Compare (Left, Right : Node_Id) return Node_Id;
-- Returns Left >= Right for Max, Left <= Right for Min
------------------
-- Make_Compare --
------------------
function Make_Compare (Left, Right : Node_Id) return Node_Id is
begin
if Attribute_Name (N) = Name_Max then
return
Make_Op_Ge (Loc,
Left_Opnd => Left,
Right_Opnd => Right);
else
return
Make_Op_Le (Loc,
Left_Opnd => Left,
Right_Opnd => Right);
end if;
end Make_Compare;
-- Start of processing for Min_Max
begin
-- If both Left and Right are side effect free, then we can just
-- use Duplicate_Expr to duplicate the references and return
-- (if Left >=|<= Right then Left else Right)
if Side_Effect_Free (Left) and then Side_Effect_Free (Right) then
Rewrite (N,
Make_If_Expression (Loc,
Expressions => New_List (
Make_Compare (Left, Right),
Duplicate_Subexpr_No_Checks (Left),
Duplicate_Subexpr_No_Checks (Right))));
-- Otherwise we generate declarations to capture the values. We
-- can't put these declarations inside the if expression, since
-- we could end up with an N_Expression_With_Actions which has
-- declarations in the actions, forbidden for Modify_Tree_For_C.
-- The translation is
-- T1 : styp; -- inserted high up in tree
-- T2 : styp; -- inserted high up in tree
-- do
-- T1 := styp!(Left);
-- T2 := styp!(Right);
-- in
-- (if T1 >=|<= T2 then typ!(T1) else typ!(T2))
-- end;
-- We insert the T1,T2 declarations with Insert_Declaration which
-- inserts these declarations high up in the tree unconditionally.
-- This is safe since no code is associated with the declarations.
-- Here styp is a standard type whose Esize matches the size of
-- our type. We do this because the actual type may be a result of
-- some local declaration which would not be visible at the point
-- where we insert the declarations of T1 and T2.
else
declare
T1 : constant Entity_Id := Make_Temporary (Loc, 'T', Left);
T2 : constant Entity_Id := Make_Temporary (Loc, 'T', Left);
Styp : constant Entity_Id := Matching_Standard_Type (Typ);
begin
Insert_Declaration (N,
Make_Object_Declaration (Loc,
Defining_Identifier => T1,
Object_Definition => New_Occurrence_Of (Styp, Loc)));
Insert_Declaration (N,
Make_Object_Declaration (Loc,
Defining_Identifier => T2,
Object_Definition => New_Occurrence_Of (Styp, Loc)));
Rewrite (N,
Make_Expression_With_Actions (Loc,
Actions => New_List (
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (T1, Loc),
Expression => Unchecked_Convert_To (Styp, Left)),
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (T2, Loc),
Expression => Unchecked_Convert_To (Styp, Right))),
Expression =>
Make_If_Expression (Loc,
Expressions => New_List (
Make_Compare
(New_Occurrence_Of (T1, Loc),
New_Occurrence_Of (T2, Loc)),
Unchecked_Convert_To (Typ,
New_Occurrence_Of (T1, Loc)),
Unchecked_Convert_To (Typ,
New_Occurrence_Of (T2, Loc))))));
end;
end if;
Analyze_And_Resolve (N, Typ);
end;
end if;
end Expand_Min_Max_Attribute;
----------------------------------
-- 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 may be 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
when Attribute_Constant_Indexing |
Attribute_Default_Iterator |
Attribute_Implicit_Dereference |
Attribute_Iterable |
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_Limited_With (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_Limited_With (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).
-- The code may be nested in a block, so find enclosing
-- scope that is a protected operation.
else
declare
Subp : Entity_Id;
begin
Subp := Current_Scope;
while Ekind_In (Subp, E_Loop, E_Block) loop
Subp := Scope (Subp);
end loop;
Formal :=
First_Entity
(Protected_Body_Subprogram (Subp));
-- For a protected subprogram the _Object parameter
-- is the protected record, so we create an access
-- to it. The _Object parameter of an entry is an
-- address.
if Ekind (Subp) = E_Entry then
Rewrite (N,
Unchecked_Convert_To (Typ,
New_Occurrence_Of (Formal, Loc)));
Set_Etype (N, Typ);
else
Rewrite (N,
Unchecked_Convert_To (Typ,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Unrestricted_Access,
Prefix =>
New_Occurrence_Of (Formal, Loc))));
Analyze_And_Resolve (N);
end if;
end;
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_Occurrence_Of (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_Occurrence_Of (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;
---------
-- 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_Occurrence_Of (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_Occurrence_Of (RTE (RE_Callable), Loc),
Parameter_Associations => New_List (
Make_Unchecked_Type_Conversion (Loc,
Subtype_Mark =>
New_Occurrence_Of (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_Occurrence_Of
(RTE (RE_Protected_Entry_Caller), Loc);
when System_Tasking_Protected_Objects_Single_Entry =>
Name :=
New_Occurrence_Of
(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_Occurrence_Of
(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_Occurrence_Of (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 Object_Type_Has_Constrained_Partial_View
(Typ => Base_Type (Etype (Obj)),
Scop => Current_Scope)));
end if;
end Is_Constrained_Aliased_View;
-- Start of processing for 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_Occurrence_Of (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_Occurrence_Of (
Boolean_Literals (
not Is_Variable (Pref)
or else
(Nkind (Pref) = N_Explicit_Dereference
and then
not Object_Type_Has_Constrained_Partial_View
(Typ => Base_Type (Ptyp),
Scop => Current_Scope))
or else Is_Constrained (Underlying_Type (Ptyp))
or else (Ada_Version >= Ada_2012
and then Is_Tagged_Type (Underlying_Type (Ptyp))
and then Is_Limited_Type (Ptyp))),
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_Occurrence_Of (RTE (RE_Protected_Count), Loc);
Call :=
Make_Function_Call (Loc,
Name => Name,
Parameter_Associations => New_List (
New_Occurrence_Of
(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_Occurrence_Of (RTE (RE_Protected_Count_Entry), Loc);
Call :=
Make_Function_Call (Loc,
Name => Name,
Parameter_Associations => New_List (
New_Occurrence_Of
(Find_Protection_Object (Current_Scope), Loc)));
when others =>
raise Program_Error;
end case;
-- Task case
else
Call :=
Make_Function_Call (Loc,
Name => New_Occurrence_Of (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_Occurrence_Of (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_Occurrence_Of (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_Impl_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_Occurrence_Of (Get_Index_Subtype (N), Loc)));
Analyze_And_Resolve (N, Typ);
-- For access type, apply access check as needed
elsif Is_Access_Type (Ptyp) then
Apply_Access_Check (N);
-- For scalar type, if low bound is a reference to an entity, just
-- replace with a direct reference. Note that we can only have a
-- reference to a constant entity at this stage, anything else would
-- have already been rewritten.
elsif Is_Scalar_Type (Ptyp) then
declare
Lo : constant Node_Id := Type_Low_Bound (Ptyp);
begin
if Is_Entity_Name (Lo) then
Rewrite (N, New_Occurrence_Of (Entity (Lo), Loc));
end if;
end;
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 non-default 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 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 default 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_Occurrence_Of (RTE (RE_Fore), Loc),
Parameter_Associations => New_List (
Convert_To (Universal_Real,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Attribute_Name => Name_First)),
Convert_To (Universal_Real,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (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;
----------------------
-- Has_Same_Storage --
----------------------
when Attribute_Has_Same_Storage => Has_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 Has_Same_Storage;
--------------
-- 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_Occurrence_Of (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;
-- Stream operations can appear in user code even if the restriction
-- No_Streams is active (for example, when instantiating a predefined
-- container). In that case rewrite the attribute as a Raise to
-- prevent any run-time use.
if Restriction_Active (No_Streams) then
Rewrite (N,
Make_Raise_Program_Error (Sloc (N),
Reason => PE_Stream_Operation_Not_Allowed));
Set_Etype (N, B_Type);
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);
Expr : Node_Id;
begin
-- Read the internal tag (RM 13.13.2(34)) and use it to
-- initialize a dummy tag value:
-- Descendant_Tag (String'Input (Strm), P_Type);
-- This value 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).
-- Note: we used to generate an explicit declaration of a
-- constant Ada.Tags.Tag object, and use an occurrence of
-- this constant in Cntrl, but this caused a secondary stack
-- leak.
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_Occurrence_Of (P_Type, Loc),
Attribute_Name => Name_Tag)));
Set_Etype (Expr, RTE (RE_Tag));
-- 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, Expr);
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_Impl_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_Occurrence_Of (Get_Index_Subtype (N), Loc)));
Analyze_And_Resolve (N, Typ);
-- For access type, apply access check as needed
elsif Is_Access_Type (Ptyp) then
Apply_Access_Check (N);
-- For scalar type, if low bound is a reference to an entity, just
-- replace with a direct reference. Note that we can only have a
-- reference to a constant entity at this stage, anything else would
-- have already been rewritten.
elsif Is_Scalar_Type (Ptyp) then
declare
Hi : constant Node_Id := Type_High_Bound (Ptyp);
begin
if Is_Entity_Name (Hi) then
Rewrite (N, New_Occurrence_Of (Entity (Hi), Loc));
end if;
end;
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 non-default 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 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 default 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_Impl_Type representation defined,
-- then replace this attribute with a 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).s
elsif Is_Constrained (Ptyp) then
Rewrite (N,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Range_Length,
Prefix => New_Occurrence_Of (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;
-- Attribute Loop_Entry is replaced with a reference to a constant value
-- which captures the prefix at the entry point of the related loop. The
-- loop itself may be transformed into a conditional block.
when Attribute_Loop_Entry =>
Expand_Loop_Entry_Attribute (N);
-------------
-- Machine --
-------------
-- Transforms 'Machine into a call to the floating-point attribute
-- function Machine in Fat_xxx (where xxx is the root type).
-- Expansion is avoided for cases the back end can handle directly.
when Attribute_Machine =>
if not Is_Inline_Floating_Point_Attribute (N) then
Expand_Fpt_Attribute_R (N);
end if;
----------------------
-- 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 --
---------
when Attribute_Max =>
Expand_Min_Max_Attribute (N);
----------------------------------
-- 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
-- If the prefix is X'Class, we transform it into a direct reference
-- to the class-wide type, because the back end must not see a 'Class
-- reference. See also 'Size.
if Is_Entity_Name (Pref)
and then Is_Class_Wide_Type (Entity (Pref))
then
Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
return;
end if;
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;
pragma Assert (Nkind (Attr) = N_Attribute_Reference);
-- 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 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_Occurrence_Of
(RTE (RE_Header_Size_With_Padding), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (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_Occurrence_Of (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 i the renamed case
if Is_Entity_Name (Pref)
and then Present (Alias (Entity (Pref)))
then
Set_Renamed_Subprogram (Pref, Alias (Entity (Pref)));
end if;
---------
-- Min --
---------
when Attribute_Min =>
Expand_Min_Max_Attribute (N);
---------
-- Mod --
---------