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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ U T I L --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2004, 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 2, 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 COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Checks; use Checks;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Ch7; use Exp_Ch7;
with Exp_Ch11; use Exp_Ch11;
with Exp_Tss; use Exp_Tss;
with Hostparm; use Hostparm;
with Inline; use Inline;
with Itypes; use Itypes;
with Lib; use Lib;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Restrict; use Restrict;
with Sem; use Sem;
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 Urealp; use Urealp;
with Validsw; use Validsw;
package body Exp_Util is
-----------------------
-- Local Subprograms --
-----------------------
function Build_Task_Array_Image
(Loc : Source_Ptr;
Id_Ref : Node_Id;
A_Type : Entity_Id;
Dyn : Boolean := False)
return Node_Id;
-- Build function to generate the image string for a task that is an
-- array component, concatenating the images of each index. To avoid
-- storage leaks, the string is built with successive slice assignments.
-- The flag Dyn indicates whether this is called for the initialization
-- procedure of an array of tasks, or for the name of a dynamically
-- created task that is assigned to an indexed component.
function Build_Task_Image_Function
(Loc : Source_Ptr;
Decls : List_Id;
Stats : List_Id;
Res : Entity_Id)
return Node_Id;
-- Common processing for Task_Array_Image and Task_Record_Image.
-- Build function body that computes image.
procedure Build_Task_Image_Prefix
(Loc : Source_Ptr;
Len : out Entity_Id;
Res : out Entity_Id;
Pos : out Entity_Id;
Prefix : Entity_Id;
Sum : Node_Id;
Decls : in out List_Id;
Stats : in out List_Id);
-- Common processing for Task_Array_Image and Task_Record_Image.
-- Create local variables and assign prefix of name to result string.
function Build_Task_Record_Image
(Loc : Source_Ptr;
Id_Ref : Node_Id;
Dyn : Boolean := False)
return Node_Id;
-- Build function to generate the image string for a task that is a
-- record component. Concatenate name of variable with that of selector.
-- The flag Dyn indicates whether this is called for the initialization
-- procedure of record with task components, or for a dynamically
-- created task that is assigned to a selected component.
function Make_CW_Equivalent_Type
(T : Entity_Id;
E : Node_Id)
return Entity_Id;
-- T is a class-wide type entity, E is the initial expression node that
-- constrains T in case such as: " X: T := E" or "new T'(E)"
-- This function returns the entity of the Equivalent type and inserts
-- on the fly the necessary declaration such as:
--
-- type anon is record
-- _parent : Root_Type (T); constrained with E discriminants (if any)
-- Extension : String (1 .. expr to match size of E);
-- end record;
--
-- This record is compatible with any object of the class of T thanks
-- to the first field and has the same size as E thanks to the second.
function Make_Literal_Range
(Loc : Source_Ptr;
Literal_Typ : Entity_Id)
return Node_Id;
-- Produce a Range node whose bounds are:
-- Low_Bound (Literal_Type) ..
-- Low_Bound (Literal_Type) + Length (Literal_Typ) - 1
-- this is used for expanding declarations like X : String := "sdfgdfg";
function New_Class_Wide_Subtype
(CW_Typ : Entity_Id;
N : Node_Id)
return Entity_Id;
-- Create an implicit subtype of CW_Typ attached to node N.
----------------------
-- Adjust_Condition --
----------------------
procedure Adjust_Condition (N : Node_Id) is
begin
if No (N) then
return;
end if;
declare
Loc : constant Source_Ptr := Sloc (N);
T : constant Entity_Id := Etype (N);
Ti : Entity_Id;
begin
-- For now, we simply ignore a call where the argument has no
-- type (probably case of unanalyzed condition), or has a type
-- that is not Boolean. This is because this is a pretty marginal
-- piece of functionality, and violations of these rules are
-- likely to be truly marginal (how much code uses Fortran Logical
-- as the barrier to a protected entry?) and we do not want to
-- blow up existing programs. We can change this to an assertion
-- after 3.12a is released ???
if No (T) or else not Is_Boolean_Type (T) then
return;
end if;
-- Apply validity checking if needed
if Validity_Checks_On and Validity_Check_Tests then
Ensure_Valid (N);
end if;
-- Immediate return if standard boolean, the most common case,
-- where nothing needs to be done.
if Base_Type (T) = Standard_Boolean then
return;
end if;
-- Case of zero/non-zero semantics or non-standard enumeration
-- representation. In each case, we rewrite the node as:
-- ityp!(N) /= False'Enum_Rep
-- where ityp is an integer type with large enough size to hold
-- any value of type T.
if Nonzero_Is_True (T) or else Has_Non_Standard_Rep (T) then
if Esize (T) <= Esize (Standard_Integer) then
Ti := Standard_Integer;
else
Ti := Standard_Long_Long_Integer;
end if;
Rewrite (N,
Make_Op_Ne (Loc,
Left_Opnd => Unchecked_Convert_To (Ti, N),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Enum_Rep,
Prefix =>
New_Occurrence_Of (First_Literal (T), Loc))));
Analyze_And_Resolve (N, Standard_Boolean);
else
Rewrite (N, Convert_To (Standard_Boolean, N));
Analyze_And_Resolve (N, Standard_Boolean);
end if;
end;
end Adjust_Condition;
------------------------
-- Adjust_Result_Type --
------------------------
procedure Adjust_Result_Type (N : Node_Id; T : Entity_Id) is
begin
-- Ignore call if current type is not Standard.Boolean
if Etype (N) /= Standard_Boolean then
return;
end if;
-- If result is already of correct type, nothing to do. Note that
-- this will get the most common case where everything has a type
-- of Standard.Boolean.
if Base_Type (T) = Standard_Boolean then
return;
else
declare
KP : constant Node_Kind := Nkind (Parent (N));
begin
-- If result is to be used as a Condition in the syntax, no need
-- to convert it back, since if it was changed to Standard.Boolean
-- using Adjust_Condition, that is just fine for this usage.
if KP in N_Raise_xxx_Error or else KP in N_Has_Condition then
return;
-- If result is an operand of another logical operation, no need
-- to reset its type, since Standard.Boolean is just fine, and
-- such operations always do Adjust_Condition on their operands.
elsif KP in N_Op_Boolean
or else KP = N_And_Then
or else KP = N_Or_Else
or else KP = N_Op_Not
then
return;
-- Otherwise we perform a conversion from the current type,
-- which must be Standard.Boolean, to the desired type.
else
Set_Analyzed (N);
Rewrite (N, Convert_To (T, N));
Analyze_And_Resolve (N, T);
end if;
end;
end if;
end Adjust_Result_Type;
--------------------------
-- Append_Freeze_Action --
--------------------------
procedure Append_Freeze_Action (T : Entity_Id; N : Node_Id) is
Fnode : Node_Id := Freeze_Node (T);
begin
Ensure_Freeze_Node (T);
Fnode := Freeze_Node (T);
if not Present (Actions (Fnode)) then
Set_Actions (Fnode, New_List);
end if;
Append (N, Actions (Fnode));
end Append_Freeze_Action;
---------------------------
-- Append_Freeze_Actions --
---------------------------
procedure Append_Freeze_Actions (T : Entity_Id; L : List_Id) is
Fnode : constant Node_Id := Freeze_Node (T);
begin
if No (L) then
return;
else
if No (Actions (Fnode)) then
Set_Actions (Fnode, L);
else
Append_List (L, Actions (Fnode));
end if;
end if;
end Append_Freeze_Actions;
------------------------
-- Build_Runtime_Call --
------------------------
function Build_Runtime_Call (Loc : Source_Ptr; RE : RE_Id) return Node_Id is
begin
-- If entity is not available, we can skip making the call (this avoids
-- junk duplicated error messages in a number of cases).
if not RTE_Available (RE) then
return Make_Null_Statement (Loc);
else
return
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE), Loc));
end if;
end Build_Runtime_Call;
-----------------------------
-- Build_Task_Array_Image --
-----------------------------
-- This function generates the body for a function that constructs the
-- image string for a task that is an array component. The function is
-- local to the init proc for the array type, and is called for each one
-- of the components. The constructed image has the form of an indexed
-- component, whose prefix is the outer variable of the array type.
-- The n-dimensional array type has known indices Index, Index2...
-- Id_Ref is an indexed component form created by the enclosing init proc.
-- Its successive indices are Val1, Val2,.. which are the loop variables
-- in the loops that call the individual task init proc on each component.
-- The generated function has the following structure:
-- function F return String is
-- Pref : string renames Task_Name;
-- T1 : String := Index1'Image (Val1);
-- ...
-- Tn : String := indexn'image (Valn);
-- Len : Integer := T1'Length + ... + Tn'Length + n + 1;
-- -- Len includes commas and the end parentheses.
-- Res : String (1..Len);
-- Pos : Integer := Pref'Length;
--
-- begin
-- Res (1 .. Pos) := Pref;
-- Pos := Pos + 1;
-- Res (Pos) := '(';
-- Pos := Pos + 1;
-- Res (Pos .. Pos + T1'Length - 1) := T1;
-- Pos := Pos + T1'Length;
-- Res (Pos) := '.';
-- Pos := Pos + 1;
-- ...
-- Res (Pos .. Pos + Tn'Length - 1) := Tn;
-- Res (Len) := ')';
--
-- return Res;
-- end F;
--
-- Needless to say, multidimensional arrays of tasks are rare enough
-- that the bulkiness of this code is not really a concern.
function Build_Task_Array_Image
(Loc : Source_Ptr;
Id_Ref : Node_Id;
A_Type : Entity_Id;
Dyn : Boolean := False)
return Node_Id
is
Dims : constant Nat := Number_Dimensions (A_Type);
-- Number of dimensions for array of tasks.
Temps : array (1 .. Dims) of Entity_Id;
-- Array of temporaries to hold string for each index.
Indx : Node_Id;
-- Index expression
Len : Entity_Id;
-- Total length of generated name
Pos : Entity_Id;
-- Running index for substring assignments
Pref : Entity_Id;
-- Name of enclosing variable, prefix of resulting name
Res : Entity_Id;
-- String to hold result
Val : Node_Id;
-- Value of successive indices
Sum : Node_Id;
-- Expression to compute total size of string
T : Entity_Id;
-- Entity for name at one index position
Decls : List_Id := New_List;
Stats : List_Id := New_List;
begin
Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
-- For a dynamic task, the name comes from the target variable.
-- For a static one it is a formal of the enclosing init proc.
if Dyn then
Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Pref,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Expression =>
Make_String_Literal (Loc, Strval => String_From_Name_Buffer)));
else
Append_To (Decls,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Pref,
Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
Name => Make_Identifier (Loc, Name_uTask_Name)));
end if;
Indx := First_Index (A_Type);
Val := First (Expressions (Id_Ref));
for J in 1 .. Dims loop
T := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
Temps (J) := T;
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => T,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Image,
Prefix =>
New_Occurrence_Of (Etype (Indx), Loc),
Expressions => New_List (
New_Copy_Tree (Val)))));
Next_Index (Indx);
Next (Val);
end loop;
Sum := Make_Integer_Literal (Loc, Dims + 1);
Sum :=
Make_Op_Add (Loc,
Left_Opnd => Sum,
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix =>
New_Occurrence_Of (Pref, Loc),
Expressions => New_List (Make_Integer_Literal (Loc, 1))));
for J in 1 .. Dims loop
Sum :=
Make_Op_Add (Loc,
Left_Opnd => Sum,
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix =>
New_Occurrence_Of (Temps (J), Loc),
Expressions => New_List (Make_Integer_Literal (Loc, 1))));
end loop;
Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
Set_Character_Literal_Name (Char_Code (Character'Pos ('(')));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => Make_Indexed_Component (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
Expression =>
Make_Character_Literal (Loc,
Chars => Name_Find,
Char_Literal_Value =>
Char_Code (Character'Pos ('(')))));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd => Make_Integer_Literal (Loc, 1))));
for J in 1 .. Dims loop
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => Make_Slice (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Discrete_Range =>
Make_Range (Loc,
Low_Bound => New_Occurrence_Of (Pos, Loc),
High_Bound => Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix =>
New_Occurrence_Of (Temps (J), Loc),
Expressions =>
New_List (Make_Integer_Literal (Loc, 1)))),
Right_Opnd => Make_Integer_Literal (Loc, 1)))),
Expression => New_Occurrence_Of (Temps (J), Loc)));
if J < Dims then
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix => New_Occurrence_Of (Temps (J), Loc),
Expressions =>
New_List (Make_Integer_Literal (Loc, 1))))));
Set_Character_Literal_Name (Char_Code (Character'Pos (',')));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => Make_Indexed_Component (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
Expression =>
Make_Character_Literal (Loc,
Chars => Name_Find,
Char_Literal_Value =>
Char_Code (Character'Pos (',')))));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd => Make_Integer_Literal (Loc, 1))));
end if;
end loop;
Set_Character_Literal_Name (Char_Code (Character'Pos (')')));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => Make_Indexed_Component (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Expressions => New_List (New_Occurrence_Of (Len, Loc))),
Expression =>
Make_Character_Literal (Loc,
Chars => Name_Find,
Char_Literal_Value =>
Char_Code (Character'Pos (')')))));
return Build_Task_Image_Function (Loc, Decls, Stats, Res);
end Build_Task_Array_Image;
----------------------------
-- Build_Task_Image_Decls --
----------------------------
function Build_Task_Image_Decls
(Loc : Source_Ptr;
Id_Ref : Node_Id;
A_Type : Entity_Id)
return List_Id
is
Decls : constant List_Id := New_List;
T_Id : Entity_Id := Empty;
Decl : Node_Id;
Expr : Node_Id := Empty;
Fun : Node_Id := Empty;
Is_Dyn : constant Boolean :=
Nkind (Parent (Id_Ref)) = N_Assignment_Statement
and then
Nkind (Expression (Parent (Id_Ref))) = N_Allocator;
begin
-- If Discard_Names or No_Implicit_Heap_Allocations are in effect,
-- generate a dummy declaration only.
if Restrictions (No_Implicit_Heap_Allocations)
or else Global_Discard_Names
then
T_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
Name_Len := 0;
return
New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => T_Id,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Expression =>
Make_String_Literal
(Loc, Strval => String_From_Name_Buffer)));
else
if Nkind (Id_Ref) = N_Identifier
or else Nkind (Id_Ref) = N_Defining_Identifier
then
-- For a simple variable, the image of the task is the name
-- of the variable.
T_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (Id_Ref), 'T'));
Get_Name_String (Chars (Id_Ref));
Expr := Make_String_Literal
(Loc, Strval => String_From_Name_Buffer);
elsif Nkind (Id_Ref) = N_Selected_Component then
T_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (Selector_Name (Id_Ref)), 'T'));
Fun := Build_Task_Record_Image (Loc, Id_Ref, Is_Dyn);
elsif Nkind (Id_Ref) = N_Indexed_Component then
T_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (A_Type), 'N'));
Fun := Build_Task_Array_Image (Loc, Id_Ref, A_Type, Is_Dyn);
end if;
end if;
if Present (Fun) then
Append (Fun, Decls);
Expr := Make_Function_Call (Loc,
Name => New_Occurrence_Of (Defining_Entity (Fun), Loc));
end if;
Decl := Make_Object_Declaration (Loc,
Defining_Identifier => T_Id,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Constant_Present => True,
Expression => Expr);
Append (Decl, Decls);
return Decls;
end Build_Task_Image_Decls;
-------------------------------
-- Build_Task_Image_Function --
-------------------------------
function Build_Task_Image_Function
(Loc : Source_Ptr;
Decls : List_Id;
Stats : List_Id;
Res : Entity_Id)
return Node_Id
is
Spec : Node_Id;
begin
Append_To (Stats,
Make_Return_Statement (Loc,
Expression => New_Occurrence_Of (Res, Loc)));
Spec := Make_Function_Specification (Loc,
Defining_Unit_Name =>
Make_Defining_Identifier (Loc, New_Internal_Name ('F')),
Subtype_Mark => New_Occurrence_Of (Standard_String, Loc));
-- Calls to 'Image use the secondary stack, which must be cleaned
-- up after the task name is built.
Set_Uses_Sec_Stack (Defining_Unit_Name (Spec));
return Make_Subprogram_Body (Loc,
Specification => Spec,
Declarations => Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc, Statements => Stats));
end Build_Task_Image_Function;
-----------------------------
-- Build_Task_Image_Prefix --
-----------------------------
procedure Build_Task_Image_Prefix
(Loc : Source_Ptr;
Len : out Entity_Id;
Res : out Entity_Id;
Pos : out Entity_Id;
Prefix : Entity_Id;
Sum : Node_Id;
Decls : in out List_Id;
Stats : in out List_Id)
is
begin
Len := Make_Defining_Identifier (Loc, New_Internal_Name ('L'));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Len,
Object_Definition => New_Occurrence_Of (Standard_Integer, Loc),
Expression => Sum));
Res := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Res,
Object_Definition =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints =>
New_List (
Make_Range (Loc,
Low_Bound => Make_Integer_Literal (Loc, 1),
High_Bound => New_Occurrence_Of (Len, Loc)))))));
Pos := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Pos,
Object_Definition => New_Occurrence_Of (Standard_Integer, Loc)));
-- Pos := Prefix'Length;
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix => New_Occurrence_Of (Prefix, Loc),
Expressions =>
New_List (Make_Integer_Literal (Loc, 1)))));
-- Res (1 .. Pos) := Prefix;
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => Make_Slice (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Discrete_Range =>
Make_Range (Loc,
Low_Bound => Make_Integer_Literal (Loc, 1),
High_Bound => New_Occurrence_Of (Pos, Loc))),
Expression => New_Occurrence_Of (Prefix, Loc)));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd => Make_Integer_Literal (Loc, 1))));
end Build_Task_Image_Prefix;
-----------------------------
-- Build_Task_Record_Image --
-----------------------------
function Build_Task_Record_Image
(Loc : Source_Ptr;
Id_Ref : Node_Id;
Dyn : Boolean := False)
return Node_Id
is
Len : Entity_Id;
-- Total length of generated name
Pos : Entity_Id;
-- Index into result
Res : Entity_Id;
-- String to hold result
Pref : Entity_Id;
-- Name of enclosing variable, prefix of resulting name
Sum : Node_Id;
-- Expression to compute total size of string.
Sel : Entity_Id;
-- Entity for selector name
Decls : List_Id := New_List;
Stats : List_Id := New_List;
begin
Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
-- For a dynamic task, the name comes from the target variable.
-- For a static one it is a formal of the enclosing init proc.
if Dyn then
Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Pref,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Expression =>
Make_String_Literal (Loc, Strval => String_From_Name_Buffer)));
else
Append_To (Decls,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Pref,
Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
Name => Make_Identifier (Loc, Name_uTask_Name)));
end if;
Sel := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
Get_Name_String (Chars (Selector_Name (Id_Ref)));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Sel,
Object_Definition => New_Occurrence_Of (Standard_String, Loc),
Expression =>
Make_String_Literal (Loc, Strval => String_From_Name_Buffer)));
Sum := Make_Integer_Literal (Loc, Nat (Name_Len + 1));
Sum :=
Make_Op_Add (Loc,
Left_Opnd => Sum,
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Length,
Prefix =>
New_Occurrence_Of (Pref, Loc),
Expressions => New_List (Make_Integer_Literal (Loc, 1))));
Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
Set_Character_Literal_Name (Char_Code (Character'Pos ('.')));
-- Res (Pos) := '.';
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => Make_Indexed_Component (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
Expression =>
Make_Character_Literal (Loc,
Chars => Name_Find,
Char_Literal_Value =>
Char_Code (Character'Pos ('.')))));
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Pos, Loc),
Expression =>
Make_Op_Add (Loc,
Left_Opnd => New_Occurrence_Of (Pos, Loc),
Right_Opnd => Make_Integer_Literal (Loc, 1))));
-- Res (Pos .. Len) := Selector;
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => Make_Slice (Loc,
Prefix => New_Occurrence_Of (Res, Loc),
Discrete_Range =>
Make_Range (Loc,
Low_Bound => New_Occurrence_Of (Pos, Loc),
High_Bound => New_Occurrence_Of (Len, Loc))),
Expression => New_Occurrence_Of (Sel, Loc)));
return Build_Task_Image_Function (Loc, Decls, Stats, Res);
end Build_Task_Record_Image;
----------------------------------
-- Component_May_Be_Bit_Aligned --
----------------------------------
function Component_May_Be_Bit_Aligned (Comp : Entity_Id) return Boolean is
begin
-- If no component clause, then everything is fine, since the
-- back end never bit-misaligns by default, even if there is
-- a pragma Packed for the record.
if No (Component_Clause (Comp)) then
return False;
end if;
-- It is only array and record types that cause trouble
if not Is_Record_Type (Etype (Comp))
and then not Is_Array_Type (Etype (Comp))
then
return False;
-- If we know that we have a small (64 bits or less) record
-- or bit-packed array, then everything is fine, since the
-- back end can handle these cases correctly.
elsif Esize (Comp) <= 64
and then (Is_Record_Type (Etype (Comp))
or else Is_Bit_Packed_Array (Etype (Comp)))
then
return False;
-- Otherwise if the component is not byte aligned, we
-- know we have the nasty unaligned case.
elsif Normalized_First_Bit (Comp) /= Uint_0
or else Esize (Comp) mod System_Storage_Unit /= Uint_0
then
return True;
-- If we are large and byte aligned, then OK at this level
else
return False;
end if;
end Component_May_Be_Bit_Aligned;
-------------------------------
-- Convert_To_Actual_Subtype --
-------------------------------
procedure Convert_To_Actual_Subtype (Exp : Entity_Id) is
Act_ST : Entity_Id;
begin
Act_ST := Get_Actual_Subtype (Exp);
if Act_ST = Etype (Exp) then
return;
else
Rewrite (Exp,
Convert_To (Act_ST, Relocate_Node (Exp)));
Analyze_And_Resolve (Exp, Act_ST);
end if;
end Convert_To_Actual_Subtype;
-----------------------------------
-- Current_Sem_Unit_Declarations --
-----------------------------------
function Current_Sem_Unit_Declarations return List_Id is
U : Node_Id := Unit (Cunit (Current_Sem_Unit));
Decls : List_Id;
begin
-- If the current unit is a package body, locate the visible
-- declarations of the package spec.
if Nkind (U) = N_Package_Body then
U := Unit (Library_Unit (Cunit (Current_Sem_Unit)));
end if;
if Nkind (U) = N_Package_Declaration then
U := Specification (U);
Decls := Visible_Declarations (U);
if No (Decls) then
Decls := New_List;
Set_Visible_Declarations (U, Decls);
end if;
else
Decls := Declarations (U);
if No (Decls) then
Decls := New_List;
Set_Declarations (U, Decls);
end if;
end if;
return Decls;
end Current_Sem_Unit_Declarations;
-----------------------
-- Duplicate_Subexpr --
-----------------------
function Duplicate_Subexpr
(Exp : Node_Id;
Name_Req : Boolean := False)
return Node_Id
is
begin
Remove_Side_Effects (Exp, Name_Req);
return New_Copy_Tree (Exp);
end Duplicate_Subexpr;
---------------------------------
-- Duplicate_Subexpr_No_Checks --
---------------------------------
function Duplicate_Subexpr_No_Checks
(Exp : Node_Id;
Name_Req : Boolean := False)
return Node_Id
is
New_Exp : Node_Id;
begin
Remove_Side_Effects (Exp, Name_Req);
New_Exp := New_Copy_Tree (Exp);
Remove_Checks (New_Exp);
return New_Exp;
end Duplicate_Subexpr_No_Checks;
-----------------------------------
-- Duplicate_Subexpr_Move_Checks --
-----------------------------------
function Duplicate_Subexpr_Move_Checks
(Exp : Node_Id;
Name_Req : Boolean := False)
return Node_Id
is
New_Exp : Node_Id;
begin
Remove_Side_Effects (Exp, Name_Req);
New_Exp := New_Copy_Tree (Exp);
Remove_Checks (Exp);
return New_Exp;
end Duplicate_Subexpr_Move_Checks;
--------------------
-- Ensure_Defined --
--------------------
procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is
IR : Node_Id;
P : Node_Id;
begin
if Is_Itype (Typ) then
IR := Make_Itype_Reference (Sloc (N));
Set_Itype (IR, Typ);
if not In_Open_Scopes (Scope (Typ))
and then Is_Subprogram (Current_Scope)
and then Scope (Current_Scope) /= Standard_Standard
then
-- Insert node in front of subprogram, to avoid scope anomalies
-- in gigi.
P := Parent (N);
while Present (P)
and then Nkind (P) /= N_Subprogram_Body
loop
P := Parent (P);
end loop;
if Present (P) then
Insert_Action (P, IR);
else
Insert_Action (N, IR);
end if;
else
Insert_Action (N, IR);
end if;
end if;
end Ensure_Defined;
---------------------
-- Evolve_And_Then --
---------------------
procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is
begin
if No (Cond) then
Cond := Cond1;
else
Cond :=
Make_And_Then (Sloc (Cond1),
Left_Opnd => Cond,
Right_Opnd => Cond1);
end if;
end Evolve_And_Then;
--------------------
-- Evolve_Or_Else --
--------------------
procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is
begin
if No (Cond) then
Cond := Cond1;
else
Cond :=
Make_Or_Else (Sloc (Cond1),
Left_Opnd => Cond,
Right_Opnd => Cond1);
end if;
end Evolve_Or_Else;
------------------------------
-- Expand_Subtype_From_Expr --
------------------------------
-- This function is applicable for both static and dynamic allocation of
-- objects which are constrained by an initial expression. Basically it
-- transforms an unconstrained subtype indication into a constrained one.
-- The expression may also be transformed in certain cases in order to
-- avoid multiple evaulation. In the static allocation case, the general
-- scheme is :
-- Val : T := Expr;
-- is transformed into
-- Val : Constrained_Subtype_of_T := Maybe_Modified_Expr;
--
-- Here are the main cases :
--
-- <if Expr is a Slice>
-- Val : T ([Index_Subtype (Expr)]) := Expr;
--
-- <elsif Expr is a String Literal>
-- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr;
--
-- <elsif Expr is Constrained>
-- subtype T is Type_Of_Expr
-- Val : T := Expr;
--
-- <elsif Expr is an entity_name>
-- Val : T (constraints taken from Expr) := Expr;
--
-- <else>
-- type Axxx is access all T;
-- Rval : Axxx := Expr'ref;
-- Val : T (constraints taken from Rval) := Rval.all;
-- ??? note: when the Expression is allocated in the secondary stack
-- we could use it directly instead of copying it by declaring
-- Val : T (...) renames Rval.all
procedure Expand_Subtype_From_Expr
(N : Node_Id;
Unc_Type : Entity_Id;
Subtype_Indic : Node_Id;
Exp : Node_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Exp_Typ : constant Entity_Id := Etype (Exp);
T : Entity_Id;
begin
-- In general we cannot build the subtype if expansion is disabled,
-- because internal entities may not have been defined. However, to
-- avoid some cascaded errors, we try to continue when the expression
-- is an array (or string), because it is safe to compute the bounds.
-- It is in fact required to do so even in a generic context, because
-- there may be constants that depend on bounds of string literal.
if not Expander_Active
and then (No (Etype (Exp))
or else Base_Type (Etype (Exp)) /= Standard_String)
then
return;
end if;
if Nkind (Exp) = N_Slice then
declare
Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ));
begin
Rewrite (Subtype_Indic,
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Reference_To (Unc_Type, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => New_List
(New_Reference_To (Slice_Type, Loc)))));
-- This subtype indication may be used later for contraint checks
-- we better make sure that if a variable was used as a bound of
-- of the original slice, its value is frozen.
Force_Evaluation (Low_Bound (Scalar_Range (Slice_Type)));
Force_Evaluation (High_Bound (Scalar_Range (Slice_Type)));
end;
elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then
Rewrite (Subtype_Indic,
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Reference_To (Unc_Type, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => New_List (
Make_Literal_Range (Loc,
Literal_Typ => Exp_Typ)))));
elsif Is_Constrained (Exp_Typ)
and then not Is_Class_Wide_Type (Unc_Type)
then
if Is_Itype (Exp_Typ) then
-- No need to generate a new one.
T := Exp_Typ;
else
T :=
Make_Defining_Identifier (Loc,
Chars => New_Internal_Name ('T'));
Insert_Action (N,
Make_Subtype_Declaration (Loc,
Defining_Identifier => T,
Subtype_Indication => New_Reference_To (Exp_Typ, Loc)));
-- This type is marked as an itype even though it has an
-- explicit declaration because otherwise it can be marked
-- with Is_Generic_Actual_Type and generate spurious errors.
-- (see sem_ch8.Analyze_Package_Renaming and sem_type.covers)
Set_Is_Itype (T);
Set_Associated_Node_For_Itype (T, Exp);
end if;
Rewrite (Subtype_Indic, New_Reference_To (T, Loc));
-- nothing needs to be done for private types with unknown discriminants
-- if the underlying type is not an unconstrained composite type.
elsif Is_Private_Type (Unc_Type)
and then Has_Unknown_Discriminants (Unc_Type)
and then (not Is_Composite_Type (Underlying_Type (Unc_Type))
or else Is_Constrained (Underlying_Type (Unc_Type)))
then
null;
else
Remove_Side_Effects (Exp);
Rewrite (Subtype_Indic,
Make_Subtype_From_Expr (Exp, Unc_Type));
end if;
end Expand_Subtype_From_Expr;
------------------
-- Find_Prim_Op --
------------------
function Find_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is
Prim : Elmt_Id;
Typ : Entity_Id := T;
begin
if Is_Class_Wide_Type (Typ) then
Typ := Root_Type (Typ);
end if;
Typ := Underlying_Type (Typ);
Prim := First_Elmt (Primitive_Operations (Typ));
while Chars (Node (Prim)) /= Name loop
Next_Elmt (Prim);
pragma Assert (Present (Prim));
end loop;
return Node (Prim);
end Find_Prim_Op;
function Find_Prim_Op
(T : Entity_Id;
Name : TSS_Name_Type) return Entity_Id
is
Prim : Elmt_Id;
Typ : Entity_Id := T;
begin
if Is_Class_Wide_Type (Typ) then
Typ := Root_Type (Typ);
end if;
Typ := Underlying_Type (Typ);
Prim := First_Elmt (Primitive_Operations (Typ));
while not Is_TSS (Node (Prim), Name) loop
Next_Elmt (Prim);
pragma Assert (Present (Prim));
end loop;
return Node (Prim);
end Find_Prim_Op;
----------------------
-- Force_Evaluation --
----------------------
procedure Force_Evaluation (Exp : Node_Id; Name_Req : Boolean := False) is
begin
Remove_Side_Effects (Exp, Name_Req, Variable_Ref => True);
end Force_Evaluation;
------------------------
-- Generate_Poll_Call --
------------------------
procedure Generate_Poll_Call (N : Node_Id) is
begin
-- No poll call if polling not active
if not Polling_Required then
return;
-- Otherwise generate require poll call
else
Insert_Before_And_Analyze (N,
Make_Procedure_Call_Statement (Sloc (N),
Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N))));
end if;
end Generate_Poll_Call;
---------------------------------
-- Get_Current_Value_Condition --
---------------------------------
procedure Get_Current_Value_Condition
(Var : Node_Id;
Op : out Node_Kind;
Val : out Node_Id)
is
Loc : constant Source_Ptr := Sloc (Var);
CV : constant Node_Id := Current_Value (Entity (Var));
Sens : Boolean;
Stm : Node_Id;
Cond : Node_Id;
begin
Op := N_Empty;
Val := Empty;
-- If statement. Condition is known true in THEN section, known False
-- in any ELSIF or ELSE part, and unknown outside the IF statement.
if Nkind (CV) = N_If_Statement then
-- Before start of IF statement
if Loc < Sloc (CV) then
return;
-- After end of IF statement
elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then
return;
end if;
-- At this stage we know that we are within the IF statement, but
-- unfortunately, the tree does not record the SLOC of the ELSE so
-- we cannot use a simple SLOC comparison to distinguish between
-- the then/else statements, so we have to climb the tree.
declare
N : Node_Id;
begin
N := Parent (Var);
while Parent (N) /= CV loop
N := Parent (N);
-- If we fall off the top of the tree, then that's odd, but
-- perhaps it could occur in some error situation, and the
-- safest response is simply to assume that the outcome of
-- the condition is unknown. No point in bombing during an
-- attempt to optimize things.
if No (N) then
return;
end if;
end loop;
-- Now we have N pointing to a node whose parent is the IF
-- statement in question, so now we can tell if we are within
-- the THEN statements.
if Is_List_Member (N)
and then List_Containing (N) = Then_Statements (CV)
then
Sens := True;
-- Otherwise we must be in ELSIF or ELSE part
else
Sens := False;
end if;
end;
-- ELSIF part. Condition is known true within the referenced
-- ELSIF, known False in any subsequent ELSIF or ELSE part,
-- and unknown before the ELSE part or after the IF statement.
elsif Nkind (CV) = N_Elsif_Part then
Stm := Parent (CV);
-- Before start of ELSIF part
if Loc < Sloc (CV) then
return;
-- After end of IF statement
elsif Loc >= Sloc (Stm) +
Text_Ptr (UI_To_Int (End_Span (Stm)))
then
return;
end if;
-- Again we lack the SLOC of the ELSE, so we need to climb the
-- tree to see if we are within the ELSIF part in question.
declare
N : Node_Id;
begin
N := Parent (Var);
while Parent (N) /= Stm loop
N := Parent (N);
-- If we fall off the top of the tree, then that's odd, but
-- perhaps it could occur in some error situation, and the
-- safest response is simply to assume that the outcome of
-- the condition is unknown. No point in bombing during an
-- attempt to optimize things.
if No (N) then
return;
end if;
end loop;
-- Now we have N pointing to a node whose parent is the IF
-- statement in question, so see if is the ELSIF part we want.
-- the THEN statements.
if N = CV then
Sens := True;
-- Otherwise we must be in susbequent ELSIF or ELSE part
else
Sens := False;
end if;
end;
-- All other cases of Current_Value settings
else
return;
end if;
-- If we fall through here, then we have a reportable
-- condition, Sens is True if the condition is true and
-- False if it needs inverting.
Cond := Condition (CV);
-- Deal with NOT operators, inverting sense
while Nkind (Cond) = N_Op_Not loop
Cond := Right_Opnd (Cond);
Sens := not Sens;
end loop;
-- Now we must have a relational operator
pragma Assert (Entity (Var) = Entity (Left_Opnd (Cond)));
Val := Right_Opnd (Cond);
Op := Nkind (Cond);
if Sens = False then
case Op is
when N_Op_Eq => Op := N_Op_Ne;
when N_Op_Ne => Op := N_Op_Eq;
when N_Op_Lt => Op := N_Op_Ge;
when N_Op_Gt => Op := N_Op_Le;
when N_Op_Le => Op := N_Op_Gt;
when N_Op_Ge => Op := N_Op_Lt;
-- No other entry should be possible
when others =>
raise Program_Error;
end case;
end if;
end Get_Current_Value_Condition;
--------------------
-- Homonym_Number --
--------------------
function Homonym_Number (Subp : Entity_Id) return Nat is
Count : Nat;
Hom : Entity_Id;
begin
Count := 1;
Hom := Homonym (Subp);
while Present (Hom) loop
if Scope (Hom) = Scope (Subp) then
Count := Count + 1;
end if;
Hom := Homonym (Hom);
end loop;
return Count;
end Homonym_Number;
------------------------------
-- In_Unconditional_Context --
------------------------------
function In_Unconditional_Context (Node : Node_Id) return Boolean is
P : Node_Id;
begin
P := Node;
while Present (P) loop
case Nkind (P) is
when N_Subprogram_Body =>
return True;
when N_If_Statement =>
return False;
when N_Loop_Statement =>
return False;
when N_Case_Statement =>
return False;
when others =>
P := Parent (P);
end case;
end loop;
return False;
end In_Unconditional_Context;
-------------------
-- Insert_Action --
-------------------
procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id) is
begin
if Present (Ins_Action) then
Insert_Actions (Assoc_Node, New_List (Ins_Action));
end if;
end Insert_Action;
-- Version with check(s) suppressed
procedure Insert_Action
(Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id)
is
begin
Insert_Actions (Assoc_Node, New_List (Ins_Action), Suppress);
end Insert_Action;
--------------------
-- Insert_Actions --
--------------------
procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id) is
N : Node_Id;
P : Node_Id;
Wrapped_Node : Node_Id := Empty;
begin
if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then
return;
end if;
-- Ignore insert of actions from inside default expression in the
-- special preliminary analyze mode. Any insertions at this point
-- have no relevance, since we are only doing the analyze to freeze
-- the types of any static expressions. See section "Handling of
-- Default Expressions" in the spec of package Sem for further details.
if In_Default_Expression then
return;
end if;
-- If the action derives from stuff inside a record, then the actions
-- are attached to the current scope, to be inserted and analyzed on
-- exit from the scope. The reason for this is that we may also
-- be generating freeze actions at the same time, and they must
-- eventually be elaborated in the correct order.
if Is_Record_Type (Current_Scope)
and then not Is_Frozen (Current_Scope)
then
if No (Scope_Stack.Table
(Scope_Stack.Last).Pending_Freeze_Actions)
then
Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions :=
Ins_Actions;
else
Append_List
(Ins_Actions,
Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions);
end if;
return;
end if;
-- We now intend to climb up the tree to find the right point to
-- insert the actions. We start at Assoc_Node, unless this node is
-- a subexpression in which case we start with its parent. We do this
-- for two reasons. First it speeds things up. Second, if Assoc_Node
-- is itself one of the special nodes like N_And_Then, then we assume
-- that an initial request to insert actions for such a node does not
-- expect the actions to get deposited in the node for later handling
-- when the node is expanded, since clearly the node is being dealt
-- with by the caller. Note that in the subexpression case, N is
-- always the child we came from.
-- N_Raise_xxx_Error is an annoying special case, it is a statement
-- if it has type Standard_Void_Type, and a subexpression otherwise.
-- otherwise. Procedure attribute references are also statements.
if Nkind (Assoc_Node) in N_Subexpr
and then (Nkind (Assoc_Node) in N_Raise_xxx_Error
or else Etype (Assoc_Node) /= Standard_Void_Type)
and then (Nkind (Assoc_Node) /= N_Attribute_Reference
or else
not Is_Procedure_Attribute_Name
(Attribute_Name (Assoc_Node)))
then
P := Assoc_Node; -- ??? does not agree with above!
N := Parent (Assoc_Node);
-- Non-subexpression case. Note that N is initially Empty in this
-- case (N is only guaranteed Non-Empty in the subexpr case).
else
P := Assoc_Node;
N := Empty;
end if;
-- Capture root of the transient scope
if Scope_Is_Transient then
Wrapped_Node := Node_To_Be_Wrapped;
end if;
loop
pragma Assert (Present (P));
case Nkind (P) is
-- Case of right operand of AND THEN or OR ELSE. Put the actions
-- in the Actions field of the right operand. They will be moved
-- out further when the AND THEN or OR ELSE operator is expanded.
-- Nothing special needs to be done for the left operand since
-- in that case the actions are executed unconditionally.
when N_And_Then | N_Or_Else =>
if N = Right_Opnd (P) then
if Present (Actions (P)) then
Insert_List_After_And_Analyze
(Last (Actions (P)), Ins_Actions);
else
Set_Actions (P, Ins_Actions);
Analyze_List (Actions (P));
end if;
return;
end if;
-- Then or Else operand of conditional expression. Add actions to
-- Then_Actions or Else_Actions field as appropriate. The actions
-- will be moved further out when the conditional is expanded.
when N_Conditional_Expression =>
declare
ThenX : constant Node_Id := Next (First (Expressions (P)));
ElseX : constant Node_Id := Next (ThenX);
begin
-- Actions belong to the then expression, temporarily
-- place them as Then_Actions of the conditional expr.
-- They will be moved to the proper place later when
-- the conditional expression is expanded.
if N = ThenX then
if Present (Then_Actions (P)) then
Insert_List_After_And_Analyze
(Last (Then_Actions (P)), Ins_Actions);
else
Set_Then_Actions (P, Ins_Actions);
Analyze_List (Then_Actions (P));
end if;
return;
-- Actions belong to the else expression, temporarily
-- place them as Else_Actions of the conditional expr.
-- They will be moved to the proper place later when
-- the conditional expression is expanded.
elsif N = ElseX then
if Present (Else_Actions (P)) then
Insert_List_After_And_Analyze
(Last (Else_Actions (P)), Ins_Actions);
else
Set_Else_Actions (P, Ins_Actions);
Analyze_List (Else_Actions (P));
end if;
return;
-- Actions belong to the condition. In this case they are
-- unconditionally executed, and so we can continue the
-- search for the proper insert point.
else
null;
end if;
end;
-- Case of appearing in the condition of a while expression or
-- elsif. We insert the actions into the Condition_Actions field.
-- They will be moved further out when the while loop or elsif
-- is analyzed.
when N_Iteration_Scheme |
N_Elsif_Part
=>
if N = Condition (P) then
if Present (Condition_Actions (P)) then
Insert_List_After_And_Analyze
(Last (Condition_Actions (P)), Ins_Actions);
else
Set_Condition_Actions (P, Ins_Actions);
-- Set the parent of the insert actions explicitly.
-- This is not a syntactic field, but we need the
-- parent field set, in particular so that freeze
-- can understand that it is dealing with condition
-- actions, and properly insert the freezing actions.
Set_Parent (Ins_Actions, P);
Analyze_List (Condition_Actions (P));
end if;
return;
end if;
-- Statements, declarations, pragmas, representation clauses.
when
-- Statements
N_Procedure_Call_Statement |
N_Statement_Other_Than_Procedure_Call |
-- Pragmas
N_Pragma |
-- Representation_Clause
N_At_Clause |
N_Attribute_Definition_Clause |
N_Enumeration_Representation_Clause |
N_Record_Representation_Clause |
-- Declarations
N_Abstract_Subprogram_Declaration |
N_Entry_Body |
N_Exception_Declaration |
N_Exception_Renaming_Declaration |
N_Formal_Object_Declaration |
N_Formal_Subprogram_Declaration |
N_Formal_Type_Declaration |
N_Full_Type_Declaration |
N_Function_Instantiation |
N_Generic_Function_Renaming_Declaration |
N_Generic_Package_Declaration |
N_Generic_Package_Renaming_Declaration |
N_Generic_Procedure_Renaming_Declaration |
N_Generic_Subprogram_Declaration |
N_Implicit_Label_Declaration |
N_Incomplete_Type_Declaration |
N_Number_Declaration |
N_Object_Declaration |
N_Object_Renaming_Declaration |
N_Package_Body |
N_Package_Body_Stub |
N_Package_Declaration |
N_Package_Instantiation |
N_Package_Renaming_Declaration |
N_Private_Extension_Declaration |
N_Private_Type_Declaration |
N_Procedure_Instantiation |
N_Protected_Body_Stub |
N_Protected_Type_Declaration |
N_Single_Task_Declaration |
N_Subprogram_Body |
N_Subprogram_Body_Stub |
N_Subprogram_Declaration |
N_Subprogram_Renaming_Declaration |
N_Subtype_Declaration |
N_Task_Body |
N_Task_Body_Stub |
N_Task_Type_Declaration |
-- Freeze entity behaves like a declaration or statement
N_Freeze_Entity
=>
-- Do not insert here if the item is not a list member (this
-- happens for example with a triggering statement, and the
-- proper approach is to insert before the entire select).
if not Is_List_Member (P) then
null;
-- Do not insert if parent of P is an N_Component_Association
-- node (i.e. we are in the context of an N_Aggregate node.
-- In this case we want to insert before the entire aggregate.
elsif Nkind (Parent (P)) = N_Component_Association then
null;
-- Do not insert if the parent of P is either an N_Variant
-- node or an N_Record_Definition node, meaning in either
-- case that P is a member of a component list, and that
-- therefore the actions should be inserted outside the
-- complete record declaration.
elsif Nkind (Parent (P)) = N_Variant
or else Nkind (Parent (P)) = N_Record_Definition
then
null;
-- Do not insert freeze nodes within the loop generated for
-- an aggregate, because they may be elaborated too late for
-- subsequent use in the back end: within a package spec the
-- loop is part of the elaboration procedure and is only
-- elaborated during the second pass.
-- If the loop comes from source, or the entity is local to
-- the loop itself it must remain within.
elsif Nkind (Parent (P)) = N_Loop_Statement
and then not Comes_From_Source (Parent (P))
and then Nkind (First (Ins_Actions)) = N_Freeze_Entity
and then
Scope (Entity (First (Ins_Actions))) /= Current_Scope
then
null;
-- Otherwise we can go ahead and do the insertion
elsif P = Wrapped_Node then
Store_Before_Actions_In_Scope (Ins_Actions);
return;
else
Insert_List_Before_And_Analyze (P, Ins_Actions);
return;
end if;
-- A special case, N_Raise_xxx_Error can act either as a
-- statement or a subexpression. We tell the difference
-- by looking at the Etype. It is set to Standard_Void_Type
-- in the statement case.
when
N_Raise_xxx_Error =>
if Etype (P) = Standard_Void_Type then
if P = Wrapped_Node then
Store_Before_Actions_In_Scope (Ins_Actions);
else
Insert_List_Before_And_Analyze (P, Ins_Actions);
end if;
return;
-- In the subexpression case, keep climbing
else
null;
end if;
-- If a component association appears within a loop created for
-- an array aggregate, attach the actions to the association so
-- they can be subsequently inserted within the loop. For other
-- component associations insert outside of the aggregate. For
-- an association that will generate a loop, its Loop_Actions
-- attribute is already initialized (see exp_aggr.adb).
-- The list of loop_actions can in turn generate additional ones,
-- that are inserted before the associated node. If the associated
-- node is outside the aggregate, the new actions are collected
-- at the end of the loop actions, to respect the order in which
-- they are to be elaborated.
when
N_Component_Association =>
if Nkind (Parent (P)) = N_Aggregate
and then Present (Loop_Actions (P))
then
if Is_Empty_List (Loop_Actions (P)) then
Set_Loop_Actions (P, Ins_Actions);
Analyze_List (Ins_Actions);
else
declare
Decl : Node_Id := Assoc_Node;
begin
-- Check whether these actions were generated
-- by a declaration that is part of the loop_
-- actions for the component_association.
while Present (Decl) loop
exit when Parent (Decl) = P
and then Is_List_Member (Decl)
and then
List_Containing (Decl) = Loop_Actions (P);
Decl := Parent (Decl);
end loop;
if Present (Decl) then
Insert_List_Before_And_Analyze
(Decl, Ins_Actions);
else
Insert_List_After_And_Analyze
(Last (Loop_Actions (P)), Ins_Actions);
end if;
end;
end if;
return;
else
null;
end if;
-- Another special case, an attribute denoting a procedure call
when
N_Attribute_Reference =>
if Is_Procedure_Attribute_Name (Attribute_Name (P)) then
if P = Wrapped_Node then
Store_Before_Actions_In_Scope (Ins_Actions);
else
Insert_List_Before_And_Analyze (P, Ins_Actions);
end if;
return;
-- In the subexpression case, keep climbing
else
null;
end if;
-- For all other node types, keep climbing tree
when
N_Abortable_Part |
N_Accept_Alternative |
N_Access_Definition |
N_Access_Function_Definition |
N_Access_Procedure_Definition |
N_Access_To_Object_Definition |
N_Aggregate |
N_Allocator |
N_Case_Statement_Alternative |
N_Character_Literal |
N_Compilation_Unit |
N_Compilation_Unit_Aux |
N_Component_Clause |
N_Component_Declaration |
N_Component_Definition |
N_Component_List |
N_Constrained_Array_Definition |
N_Decimal_Fixed_Point_Definition |
N_Defining_Character_Literal |
N_Defining_Identifier |
N_Defining_Operator_Symbol |
N_Defining_Program_Unit_Name |
N_Delay_Alternative |
N_Delta_Constraint |
N_Derived_Type_Definition |
N_Designator |
N_Digits_Constraint |
N_Discriminant_Association |
N_Discriminant_Specification |
N_Empty |
N_Entry_Body_Formal_Part |
N_Entry_Call_Alternative |
N_Entry_Declaration |
N_Entry_Index_Specification |
N_Enumeration_Type_Definition |
N_Error |
N_Exception_Handler |
N_Expanded_Name |
N_Explicit_Dereference |
N_Extension_Aggregate |
N_Floating_Point_Definition |
N_Formal_Decimal_Fixed_Point_Definition |
N_Formal_Derived_Type_Definition |
N_Formal_Discrete_Type_Definition |
N_Formal_Floating_Point_Definition |
N_Formal_Modular_Type_Definition |
N_Formal_Ordinary_Fixed_Point_Definition |
N_Formal_Package_Declaration |
N_Formal_Private_Type_Definition |
N_Formal_Signed_Integer_Type_Definition |
N_Function_Call |
N_Function_Specification |
N_Generic_Association |
N_Handled_Sequence_Of_Statements |
N_Identifier |
N_In |
N_Index_Or_Discriminant_Constraint |
N_Indexed_Component |
N_Integer_Literal |
N_Itype_Reference |
N_Label |
N_Loop_Parameter_Specification |
N_Mod_Clause |
N_Modular_Type_Definition |
N_Not_In |
N_Null |
N_Op_Abs |
N_Op_Add |
N_Op_And |
N_Op_Concat |
N_Op_Divide |
N_Op_Eq |
N_Op_Expon |
N_Op_Ge |
N_Op_Gt |
N_Op_Le |
N_Op_Lt |
N_Op_Minus |
N_Op_Mod |
N_Op_Multiply |
N_Op_Ne |
N_Op_Not |
N_Op_Or |
N_Op_Plus |
N_Op_Rem |
N_Op_Rotate_Left |
N_Op_Rotate_Right |
N_Op_Shift_Left |
N_Op_Shift_Right |
N_Op_Shift_Right_Arithmetic |
N_Op_Subtract |
N_Op_Xor |
N_Operator_Symbol |
N_Ordinary_Fixed_Point_Definition |
N_Others_Choice |
N_Package_Specification |
N_Parameter_Association |
N_Parameter_Specification |
N_Pragma_Argument_Association |
N_Procedure_Specification |
N_Protected_Body |
N_Protected_Definition |
N_Qualified_Expression |
N_Range |
N_Range_Constraint |
N_Real_Literal |
N_Real_Range_Specification |
N_Record_Definition |
N_Reference |
N_Selected_Component |
N_Signed_Integer_Type_Definition |
N_Single_Protected_Declaration |
N_Slice |
N_String_Literal |
N_Subprogram_Info |
N_Subtype_Indication |
N_Subunit |
N_Task_Definition |
N_Terminate_Alternative |
N_Triggering_Alternative |
N_Type_Conversion |
N_Unchecked_Expression |
N_Unchecked_Type_Conversion |
N_Unconstrained_Array_Definition |
N_Unused_At_End |
N_Unused_At_Start |
N_Use_Package_Clause |
N_Use_Type_Clause |
N_Variant |
N_Variant_Part |
N_Validate_Unchecked_Conversion |
N_With_Clause |
N_With_Type_Clause
=>
null;
end case;
-- Make sure that inserted actions stay in the transient scope
if P = Wrapped_Node then
Store_Before_Actions_In_Scope (Ins_Actions);
return;
end if;
-- If we fall through above tests, keep climbing tree
N := P;
if Nkind (Parent (N)) = N_Subunit then
-- This is the proper body corresponding to a stub. Insertion
-- must be done at the point of the stub, which is in the decla-
-- tive part of the parent unit.
P := Corresponding_Stub (Parent (N));
else
P := Parent (N);
end if;
end loop;
end Insert_Actions;
-- Version with check(s) suppressed
procedure Insert_Actions
(Assoc_Node : Node_Id; Ins_Actions : List_Id; Suppress : Check_Id)
is
begin
if Suppress = All_Checks then
declare
Svg : constant Suppress_Array := Scope_Suppress;
begin
Scope_Suppress := (others => True);
Insert_Actions (Assoc_Node, Ins_Actions);
Scope_Suppress := Svg;
end;
else
declare
Svg : constant Boolean := Scope_Suppress (Suppress);
begin
Scope_Suppress (Suppress) := True;
Insert_Actions (Assoc_Node, Ins_Actions);
Scope_Suppress (Suppress) := Svg;
end;
end if;
end Insert_Actions;
--------------------------
-- Insert_Actions_After --
--------------------------
procedure Insert_Actions_After
(Assoc_Node : Node_Id;
Ins_Actions : List_Id)
is
begin
if Scope_Is_Transient
and then Assoc_Node = Node_To_Be_Wrapped
then
Store_After_Actions_In_Scope (Ins_Actions);
else
Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions);
end if;
end Insert_Actions_After;
---------------------------------
-- Insert_Library_Level_Action --
---------------------------------
procedure Insert_Library_Level_Action (N : Node_Id) is
Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
begin
New_Scope (Cunit_Entity (Main_Unit));
if No (Actions (Aux)) then
Set_Actions (Aux, New_List (N));
else
Append (N, Actions (Aux));
end if;
Analyze (N);
Pop_Scope;
end Insert_Library_Level_Action;
----------------------------------
-- Insert_Library_Level_Actions --
----------------------------------
procedure Insert_Library_Level_Actions (L : List_Id) is
Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
begin
if Is_Non_Empty_List (L) then
New_Scope (Cunit_Entity (Main_Unit));
if No (Actions (Aux)) then
Set_Actions (Aux, L);
Analyze_List (L);
else
Insert_List_After_And_Analyze (Last (Actions (Aux)), L);
end if;
Pop_Scope;
end if;
end Insert_Library_Level_Actions;
----------------------
-- Inside_Init_Proc --
----------------------
function Inside_Init_Proc return Boolean is
S : Entity_Id;
begin
S := Current_Scope;
while Present (S)
and then S /= Standard_Standard
loop
if Is_Init_Proc (S) then
return True;
else
S := Scope (S);
end if;
end loop;
return False;
end Inside_Init_Proc;
----------------------------
-- Is_All_Null_Statements --
----------------------------
function Is_All_Null_Statements (L : List_Id) return Boolean is
Stm : Node_Id;
begin
Stm := First (L);
while Present (Stm) loop
if Nkind (Stm) /= N_Null_Statement then
return False;
end if;
Next (Stm);
end loop;
return True;
end Is_All_Null_Statements;
----------------------------------
-- Is_Possibly_Unaligned_Object --
----------------------------------
function Is_Possibly_Unaligned_Object (P : Node_Id) return Boolean is
begin
-- If target does not have strict alignment, result is always
-- False, since correctness of code does no depend on alignment.
if not Target_Strict_Alignment then
return False;
end if;
-- If renamed object, apply test to underlying object
if Is_Entity_Name (P)
and then Is_Object (Entity (P))
and then Present (Renamed_Object (Entity (P)))
then
return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (P)));
end if;
-- If this is an element of a packed array, may be unaligned
if Is_Ref_To_Bit_Packed_Array (P) then
return True;
end if;
-- Case of component reference
if Nkind (P) = N_Selected_Component then
-- If component reference is for a record that is bit packed
-- or has a specified alignment (that might be too small) or
-- the component reference has a component clause, then the
-- object may be unaligned.
if Is_Packed (Etype (Prefix (P)))
or else Known_Alignment (Etype (Prefix (P)))
or else Present (Component_Clause (Entity (Selector_Name (P))))
then
return True;
-- Otherwise, for a component reference, test prefix
else
return Is_Possibly_Unaligned_Object (Prefix (P));
end if;
-- If not a component reference, must be aligned
else
return False;
end if;
end Is_Possibly_Unaligned_Object;
---------------------------------
-- Is_Possibly_Unaligned_Slice --
---------------------------------
function Is_Possibly_Unaligned_Slice (P : Node_Id) return Boolean is
begin
if Is_Entity_Name (P)
and then Is_Object (Entity (P))
and then Present (Renamed_Object (Entity (P)))
then
return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (P)));
end if;
-- We only need to worry if the target has strict alignment, unless
-- it is a nested record component with a component clause, which
-- Gigi does not handle well. This patch should disappear with GCC 3.0
-- and it is not clear why it is needed even when the representation
-- clause is a confirming one, but in its absence gigi complains that
-- the slice is not addressable.???
if not Target_Strict_Alignment then
if Nkind (P) /= N_Slice
or else Nkind (Prefix (P)) /= N_Selected_Component
or else Nkind (Prefix (Prefix (P))) /= N_Selected_Component
then
return False;
end if;
end if;
-- The reference must be a slice
if Nkind (P) /= N_Slice then
return False;
end if;
-- If it is a slice, then look at the array type being sliced
declare
Pref : constant Node_Id := Prefix (P);
Typ : constant Entity_Id := Etype (Prefix (P));
begin
-- The worrisome case is one where we don't know the alignment
-- of the array, or we know it and it is greater than 1 (if the
-- alignment is one, then obviously it cannot be misaligned).
if Known_Alignment (Typ) and then Alignment (Typ) = 1 then
return False;
end if;
-- The only way we can be unaligned is if the array being sliced
-- is a component of a record, and either the record is packed,
-- or the component has a component clause, or the record has
-- a specified alignment (that might be too small).
return
Nkind (Pref) = N_Selected_Component
and then
(Is_Packed (Etype (Prefix (Pref)))
or else
Known_Alignment (Etype (Prefix (Pref)))
or else
Present (Component_Clause (Entity (Selector_Name (Pref)))));
end;
end Is_Possibly_Unaligned_Slice;
--------------------------------
-- Is_Ref_To_Bit_Packed_Array --
--------------------------------
function Is_Ref_To_Bit_Packed_Array (P : Node_Id) return Boolean is
Result : Boolean;
Expr : Node_Id;
begin
if Is_Entity_Name (P)
and then Is_Object (Entity (P))
and then Present (Renamed_Object (Entity (P)))
then
return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (P)));
end if;
if Nkind (P) = N_Indexed_Component
or else
Nkind (P) = N_Selected_Component
then
if Is_Bit_Packed_Array (Etype (Prefix (P))) then
Result := True;
else
Result := Is_Ref_To_Bit_Packed_Array (Prefix (P));
end if;
if Result and then Nkind (P) = N_Indexed_Component then
Expr := First (Expressions (P));
while Present (Expr) loop
Force_Evaluation (Expr);
Next (Expr);
end loop;
end if;
return Result;
else
return False;
end if;
end Is_Ref_To_Bit_Packed_Array;
--------------------------------
-- Is_Ref_To_Bit_Packed_Slice --
--------------------------------
function Is_Ref_To_Bit_Packed_Slice (P : Node_Id) return Boolean is
begin
if Is_Entity_Name (P)
and then Is_Object (Entity (P))
and then Present (Renamed_Object (Entity (P)))
then
return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (P)));
end if;
if Nkind (P) = N_Slice
and then Is_Bit_Packed_Array (Etype (Prefix (P)))
then
return True;
elsif Nkind (P) = N_Indexed_Component
or else
Nkind (P) = N_Selected_Component
then
return Is_Ref_To_Bit_Packed_Slice (Prefix (P));
else
return False;
end if;
end Is_Ref_To_Bit_Packed_Slice;
-----------------------
-- Is_Renamed_Object --
-----------------------
function Is_Renamed_Object (N : Node_Id) return Boolean is
Pnod : constant Node_Id := Parent (N);
Kind : constant Node_Kind := Nkind (Pnod);
begin
if Kind = N_Object_Renaming_Declaration then
return True;
elsif Kind = N_Indexed_Component
or else Kind = N_Selected_Component
then
return Is_Renamed_Object (Pnod);
else
return False;
end if;
end Is_Renamed_Object;
----------------------------
-- Is_Untagged_Derivation --
----------------------------
function Is_Untagged_Derivation (T : Entity_Id) return Boolean is
begin
return (not Is_Tagged_Type (T) and then Is_Derived_Type (T))
or else
(Is_Private_Type (T) and then Present (Full_View (T))
and then not Is_Tagged_Type (Full_View (T))
and then Is_Derived_Type (Full_View (T))
and then Etype (Full_View (T)) /= T);
end Is_Untagged_Derivation;
--------------------
-- Kill_Dead_Code --
--------------------
procedure Kill_Dead_Code (N : Node_Id) is
begin
if Present (N) then
Remove_Handler_Entries (N);
Remove_Warning_Messages (N);
-- Recurse into block statements and bodies to process declarations
-- and statements
if Nkind (N) = N_Block_Statement
or else Nkind (N) = N_Subprogram_Body
or else Nkind (N) = N_Package_Body
then
Kill_Dead_Code (Declarations (N));
Kill_Dead_Code (Statements (Handled_Statement_Sequence (N)));
if Nkind (N) = N_Subprogram_Body then
Set_Is_Eliminated (Defining_Entity (N));
end if;
-- Recurse into composite statement to kill individual statements,
-- in particular instantiations.
elsif Nkind (N) = N_If_Statement then
Kill_Dead_Code (Then_Statements (N));
Kill_Dead_Code (Elsif_Parts (N));
Kill_Dead_Code (Else_Statements (N));
elsif Nkind (N) = N_Loop_Statement then
Kill_Dead_Code (Statements (N));
elsif Nkind (N) = N_Case_Statement then
declare
Alt : Node_Id := First (Alternatives (N));
begin
while Present (Alt) loop
Kill_Dead_Code (Statements (Alt));
Next (Alt);
end loop;
end;
elsif Nkind (N) = N_Case_Statement_Alternative then
Kill_Dead_Code (Statements (N));
-- Deal with dead instances caused by deleting instantiations
elsif Nkind (N) in N_Generic_Instantiation then
Remove_Dead_Instance (N);
end if;
Delete_Tree (N);
end if;
end Kill_Dead_Code;
-- Case where argument is a list of nodes to be killed
procedure Kill_Dead_Code (L : List_Id) is
N : Node_Id;
begin
if Is_Non_Empty_List (L) then
loop
N := Remove_Head (L);
exit when No (N);
Kill_Dead_Code (N);
end loop;
end if;
end Kill_Dead_Code;
------------------------
-- Known_Non_Negative --
------------------------
function Known_Non_Negative (Opnd : Node_Id) return Boolean is
begin
if Is_OK_Static_Expression (Opnd)
and then Expr_Value (Opnd) >= 0
then
return True;
else
declare
Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd));
begin
return
Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0;
end;
end if;
end Known_Non_Negative;
--------------------
-- Known_Non_Null --
--------------------
function Known_Non_Null (N : Node_Id) return Boolean is
begin
pragma Assert (Is_Access_Type (Underlying_Type (Etype (N))));
-- Case of entity for which Is_Known_Non_Null is True
if Is_Entity_Name (N) and then Is_Known_Non_Null (Entity (N)) then
-- If the entity is aliased or volatile, then we decide that
-- we don't know it is really non-null even if the sequential
-- flow indicates that it is, since such variables can be
-- changed without us noticing.
if Is_Aliased (Entity (N))
or else Treat_As_Volatile (Entity (N))
then
return False;
-- For all other cases, the flag is decisive
else
return True;
end if;
-- True if access attribute
elsif Nkind (N) = N_Attribute_Reference
and then (Attribute_Name (N) = Name_Access
or else
Attribute_Name (N) = Name_Unchecked_Access
or else
Attribute_Name (N) = Name_Unrestricted_Access)
then
return True;
-- True if allocator
elsif Nkind (N) = N_Allocator then
return True;
-- For a conversion, true if expression is known non-null
elsif Nkind (N) = N_Type_Conversion then
return Known_Non_Null (Expression (N));
-- One more case is when Current_Value references a condition
-- that ensures a non-null value.
elsif Is_Entity_Name (N) then
declare
Op : Node_Kind;
Val : Node_Id;
begin
Get_Current_Value_Condition (N, Op, Val);
return Op = N_Op_Ne and then Nkind (Val) = N_Null;
end;
-- Above are all cases where the value could be determined to be
-- non-null. In all other cases, we don't know, so return False.
else
return False;
end if;
end Known_Non_Null;
-----------------------------
-- Make_CW_Equivalent_Type --
-----------------------------
-- Create a record type used as an equivalent of any member
-- of the class which takes its size from exp.
-- Generate the following code:
-- type Equiv_T is record
-- _parent : T (List of discriminant constaints taken from Exp);
-- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8);
-- end Equiv_T;
--
-- ??? Note that this type does not guarantee same alignment as all
-- derived types
function Make_CW_Equivalent_Type
(T : Entity_Id;
E : Node_Id)
return Entity_Id
is
Loc : constant Source_Ptr := Sloc (E);
Root_Typ : constant Entity_Id := Root_Type (T);
List_Def : constant List_Id := Empty_List;
Equiv_Type : Entity_Id;
Range_Type : Entity_Id;
Str_Type : Entity_Id;
Constr_Root : Entity_Id;
Sizexpr : Node_Id;
begin
if not Has_Discriminants (Root_Typ) then
Constr_Root := Root_Typ;
else
Constr_Root :=
Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
-- subtype cstr__n is T (List of discr constraints taken from Exp)
Append_To (List_Def,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Constr_Root,
Subtype_Indication =>
Make_Subtype_From_Expr (E, Root_Typ)));
end if;
-- subtype rg__xx is Storage_Offset range
-- (Expr'size - typ'size) / Storage_Unit
Range_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('G'));
Sizexpr :=
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix =>
OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
Attribute_Name => Name_Size),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Constr_Root, Loc),
Attribute_Name => Name_Object_Size));
Set_Paren_Count (Sizexpr, 1);
Append_To (List_Def,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Range_Type,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Reference_To (RTE (RE_Storage_Offset), Loc),
Constraint => Make_Range_Constraint (Loc,
Range_Expression =>
Make_Range (Loc,
Low_Bound => Make_Integer_Literal (Loc, 1),
High_Bound =>
Make_Op_Divide (Loc,
Left_Opnd => Sizexpr,
Right_Opnd => Make_Integer_Literal (Loc,
Intval => System_Storage_Unit)))))));
-- subtype str__nn is Storage_Array (rg__x);
Str_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
Append_To (List_Def,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Str_Type,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Reference_To (RTE (RE_Storage_Array), Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints =>
New_List (New_Reference_To (Range_Type, Loc))))));
-- type Equiv_T is record
-- _parent : Tnn;
-- E : Str_Type;
-- end Equiv_T;
Equiv_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
-- When the target requires front-end layout, it's necessary to allow
-- the equivalent type to be frozen so that layout can occur (when the
-- associated class-wide subtype is frozen, the equivalent type will
-- be frozen, see freeze.adb). For other targets, Gigi wants to have
-- the equivalent type marked as frozen and deals with this type itself.
-- In the Gigi case this will also avoid the generation of an init
-- procedure for the type.
if not Frontend_Layout_On_Target then
Set_Is_Frozen (Equiv_Type);
end if;
Set_Ekind (Equiv_Type, E_Record_Type);
Set_Parent_Subtype (Equiv_Type, Constr_Root);
Append_To (List_Def,
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Equiv_Type,
Type_Definition =>
Make_Record_Definition (Loc,
Component_List => Make_Component_List (Loc,
Component_Items => New_List (
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uParent),
Component_Definition =>
Make_Component_Definition (Loc,
Aliased_Present => False,
Subtype_Indication =>
New_Reference_To (Constr_Root, Loc))),
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc,
Chars => New_Internal_Name ('C')),
Component_Definition =>
Make_Component_Definition (Loc,
Aliased_Present => False,
Subtype_Indication =>
New_Reference_To (Str_Type, Loc)))),
Variant_Part => Empty))));
Insert_Actions (E, List_Def);
return Equiv_Type;
end Make_CW_Equivalent_Type;
------------------------
-- Make_Literal_Range --
------------------------
function Make_Literal_Range
(Loc : Source_Ptr;
Literal_Typ : Entity_Id)
return Node_Id
is
Lo : constant Node_Id :=
New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ));
begin
Set_Analyzed (Lo, False);
return
Make_Range (Loc,
Low_Bound => Lo,
High_Bound =>
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Op_Add (Loc,
Left_Opnd => New_Copy_Tree (Lo),
Right_Opnd =>
Make_Integer_Literal (Loc,
String_Literal_Length (Literal_Typ))),
Right_Opnd => Make_Integer_Literal (Loc, 1)));
end Make_Literal_Range;
----------------------------
-- Make_Subtype_From_Expr --
----------------------------
-- 1. If Expr is an uncontrained array expression, creates
-- Unc_Type(Expr'first(1)..Expr'Last(1),..., Expr'first(n)..Expr'last(n))
-- 2. If Expr is a unconstrained discriminated type expression, creates
-- Unc_Type(Expr.Discr1, ... , Expr.Discr_n)
-- 3. If Expr is class-wide, creates an implicit class wide subtype
function Make_Subtype_From_Expr
(E : Node_Id;
Unc_Typ : Entity_Id)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (E);
List_Constr : constant List_Id := New_List;
D : Entity_Id;
Full_Subtyp : Entity_Id;
Priv_Subtyp : Entity_Id;
Utyp : Entity_Id;
Full_Exp : Node_Id;
begin
if Is_Private_Type (Unc_Typ)
and then Has_Unknown_Discriminants (Unc_Typ)
then
-- Prepare the subtype completion, Go to base type to
-- find underlying type.
Utyp := Underlying_Type (Base_Type (Unc_Typ));
Full_Subtyp := Make_Defining_Identifier (Loc,
New_Internal_Name ('C'));
Full_Exp :=
Unchecked_Convert_To
(Utyp, Duplicate_Subexpr_No_Checks (E));
Set_Parent (Full_Exp, Parent (E));
Priv_Subtyp :=
Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
Insert_Action (E,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Full_Subtyp,
Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp)));
-- Define the dummy private subtype
Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ)));
Set_Etype (Priv_Subtyp, Unc_Typ);
Set_Scope (Priv_Subtyp, Full_Subtyp);
Set_Is_Constrained (Priv_Subtyp);
Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ));
Set_Is_Itype (Priv_Subtyp);
Set_Associated_Node_For_Itype (Priv_Subtyp, E);
if Is_Tagged_Type (Priv_Subtyp) then
Set_Class_Wide_Type
(Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ));
Set_Primitive_Operations (Priv_Subtyp,
Primitive_Operations (Unc_Typ));
end if;
Set_Full_View (Priv_Subtyp, Full_Subtyp);
return New_Reference_To (Priv_Subtyp, Loc);
elsif Is_Array_Type (Unc_Typ) then
for J in 1 .. Number_Dimensions (Unc_Typ) loop
Append_To (List_Constr,
Make_Range (Loc,
Low_Bound =>
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr_No_Checks (E),
Attribute_Name => Name_First,
Expressions => New_List (
Make_Integer_Literal (Loc, J))),
High_Bound =>
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr_No_Checks (E),
Attribute_Name => Name_Last,
Expressions => New_List (
Make_Integer_Literal (Loc, J)))));
end loop;
elsif Is_Class_Wide_Type (Unc_Typ) then
declare
CW_Subtype : Entity_Id;
EQ_Typ : Entity_Id := Empty;
begin
-- A class-wide equivalent type is not needed when Java_VM
-- because the JVM back end handles the class-wide object
-- initialization itself (and doesn't need or want the
-- additional intermediate type to handle the assignment).
if Expander_Active and then not Java_VM then
EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E);
end if;
CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E);
Set_Equivalent_Type (CW_Subtype, EQ_Typ);
if Present (EQ_Typ) then
Set_Is_Class_Wide_Equivalent_Type (EQ_Typ);
end if;
Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ));
return New_Occurrence_Of (CW_Subtype, Loc);
end;
-- Comment needed (what case is this ???)
else
D := First_Discriminant (Unc_Typ);
while Present (D) loop
Append_To (List_Constr,
Make_Selected_Component (Loc,
Prefix => Duplicate_Subexpr_No_Checks (E),
Selector_Name => New_Reference_To (D, Loc)));
Next_Discriminant (D);
end loop;
end if;
return
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Reference_To (Unc_Typ, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => List_Constr));
end Make_Subtype_From_Expr;
-----------------------------
-- May_Generate_Large_Temp --
-----------------------------
-- At the current time, the only types that we return False for (i.e.
-- where we decide we know they cannot generate large temps) are ones
-- where we know the size is 128 bits or less at compile time, and we
-- are still not doing a thorough job on arrays and records ???
function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is
begin
if not Stack_Checking_Enabled then
return False;
elsif not Size_Known_At_Compile_Time (Typ) then
return False;
elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then
return False;
elsif Is_Array_Type (Typ)
and then Present (Packed_Array_Type (Typ))
then
return May_Generate_Large_Temp (Packed_Array_Type (Typ));
-- We could do more here to find other small types ???
else
return True;
end if;
end May_Generate_Large_Temp;
----------------------------
-- New_Class_Wide_Subtype --
----------------------------
function New_Class_Wide_Subtype
(CW_Typ : Entity_Id;
N : Node_Id)
return Entity_Id
is
Res : constant Entity_Id := Create_Itype (E_Void, N);
Res_Name : constant Name_Id := Chars (Res);
Res_Scope : constant Entity_Id := Scope (Res);
begin
Copy_Node (CW_Typ, Res);
Set_Sloc (Res, Sloc (N));
Set_Is_Itype (Res);
Set_Associated_Node_For_Itype (Res, N);
Set_Is_Public (Res, False); -- By default, may be changed below.
Set_Public_Status (Res);
Set_Chars (Res, Res_Name);
Set_Scope (Res, Res_Scope);
Set_Ekind (Res, E_Class_Wide_Subtype);
Set_Next_Entity (Res, Empty);
Set_Etype (Res, Base_Type (CW_Typ));
-- For targets where front-end layout is required, reset the Is_Frozen
-- status of the subtype to False (it can be implicitly set to true
-- from the copy of the class-wide type). For other targets, Gigi
-- doesn't want the class-wide subtype to go through the freezing
-- process (though it's unclear why that causes problems and it would
-- be nice to allow freezing to occur normally for all targets ???).
if Frontend_Layout_On_Target then
Set_Is_Frozen (Res, False);
end if;
Set_Freeze_Node (Res, Empty);
return (Res);
end New_Class_Wide_Subtype;
-------------------------
-- Remove_Side_Effects --
-------------------------
procedure Remove_Side_Effects
(Exp : Node_Id;
Name_Req : Boolean := False;
Variable_Ref : Boolean := False)
is
Loc : constant Source_Ptr := Sloc (Exp);
Exp_Type : constant Entity_Id := Etype (Exp);
Svg_Suppress : constant Suppress_Array := Scope_Suppress;
Def_Id : Entity_Id;
Ref_Type : Entity_Id;
Res : Node_Id;
Ptr_Typ_Decl : Node_Id;
New_Exp : Node_Id;
E : Node_Id;
function Side_Effect_Free (N : Node_Id) return Boolean;
-- Determines if the tree N represents an expession that is known
-- not to have side effects, and for which no processing is required.
function Side_Effect_Free (L : List_Id) return Boolean;
-- Determines if all elements of the list L are side effect free
function Safe_Prefixed_Reference (N : Node_Id) return Boolean;
-- The argument N is a construct where the Prefix is dereferenced
-- if it is a an access type and the result is a variable. The call
-- returns True if the construct is side effect free (not considering
-- side effects in other than the prefix which are to be tested by the
-- caller).
function Within_In_Parameter (N : Node_Id) return Boolean;
-- Determines if N is a subcomponent of a composite in-parameter.
-- If so, N is not side-effect free when the actual is global and
-- modifiable indirectly from within a subprogram, because it may
-- be passed by reference. The front-end must be conservative here
-- and assume that this may happen with any array or record type.
-- On the other hand, we cannot create temporaries for all expressions
-- for which this condition is true, for various reasons that might
-- require clearing up ??? For example, descriminant references that
-- appear out of place, or spurious type errors with class-wide
-- expressions. As a result, we limit the transformation to loop
-- bounds, which is so far the only case that requires it.
-----------------------------
-- Safe_Prefixed_Reference --
-----------------------------
function Safe_Prefixed_Reference (N : Node_Id) return Boolean is
begin
-- If prefix is not side effect free, definitely not safe
if not Side_Effect_Free (Prefix (N)) then
return False;
-- If the prefix is of an access type that is not access-to-constant,
-- then this construct is a variable reference, which means it is to
-- be considered to have side effects if Variable_Ref is set True
-- Exception is an access to an entity that is a constant or an
-- in-parameter which does not come from source, and is the result
-- of a previous removal of side-effects.
elsif Is_Access_Type (Etype (Prefix (N)))
and then not Is_Access_Constant (Etype (Prefix (N)))
and then Variable_Ref
then
if not Is_Entity_Name (Prefix (N)) then
return False;
else
return Ekind (Entity (Prefix (N))) = E_Constant
or else Ekind (Entity (Prefix (N))) = E_In_Parameter;
end if;
-- The following test is the simplest way of solving a complex
-- problem uncovered by BB08-010: Side effect on loop bound that
-- is a subcomponent of a global variable:
-- If a loop bound is a subcomponent of a global variable, a
-- modification of that variable within the loop may incorrectly
-- affect the execution of the loop.
elsif not
(Nkind (Parent (Parent (N))) /= N_Loop_Parameter_Specification
or else not Within_In_Parameter (Prefix (N)))
then
return False;
-- All other cases are side effect free
else
return True;
end if;
end Safe_Prefixed_Reference;
----------------------
-- Side_Effect_Free --
----------------------
function Side_Effect_Free (N : Node_Id) return Boolean is
begin
-- Note on checks that could raise Constraint_Error. Strictly, if
-- we take advantage of 11.6, these checks do not count as side
-- effects. However, we would just as soon consider that they are
-- side effects, since the backend CSE does not work very well on
-- expressions which can raise Constraint_Error. On the other
-- hand, if we do not consider them to be side effect free, then
-- we get some awkward expansions in -gnato mode, resulting in
-- code insertions at a point where we do not have a clear model
-- for performing the insertions. See 4908-002/comment for details.
-- Special handling for entity names
if Is_Entity_Name (N) then
-- If the entity is a constant, it is definitely side effect
-- free. Note that the test of Is_Variable (N) below might
-- be expected to catch this case, but it does not, because
-- this test goes to the original tree, and we may have
-- already rewritten a variable node with a constant as
-- a result of an earlier Force_Evaluation call.
if Ekind (Entity (N)) = E_Constant
or else Ekind (Entity (N)) = E_In_Parameter
then
return True;
-- Functions are not side effect free
elsif Ekind (Entity (N)) = E_Function then
return False;
-- Variables are considered to be a side effect if Variable_Ref
-- is set or if we have a volatile variable and Name_Req is off.
-- If Name_Req is True then we can't help returning a name which
-- effectively allows multiple references in any case.
elsif Is_Variable (N) then
return not Variable_Ref
and then (not Treat_As_Volatile (Entity (N))
or else Name_Req);
-- Any other entity (e.g. a subtype name) is definitely side
-- effect free.
else
return True;
end if;
-- A value known at compile time is always side effect free
elsif Compile_Time_Known_Value (N) then
return True;
end if;
-- For other than entity names and compile time known values,
-- check the node kind for special processing.
case Nkind (N) is
-- An attribute reference is side effect free if its expressions
-- are side effect free and its prefix is side effect free or
-- is an entity reference.
-- Is this right? what about x'first where x is a variable???
when N_Attribute_Reference =>
return Side_Effect_Free (Expressions (N))
and then (Is_Entity_Name (Prefix (N))
or else Side_Effect_Free (Prefix (N)));
-- A binary operator is side effect free if and both operands
-- are side effect free. For this purpose binary operators
-- include membership tests and short circuit forms
when N_Binary_Op |
N_In |
N_Not_In |
N_And_Then |
N_Or_Else
=>
return Side_Effect_Free (Left_Opnd (N))
and then Side_Effect_Free (Right_Opnd (N));
-- An explicit dereference is side effect free only if it is
-- a side effect free prefixed reference.
when N_Explicit_Dereference =>
return Safe_Prefixed_Reference (N);
-- A call to _rep_to_pos is side effect free, since we generate
-- this pure function call ourselves. Moreover it is critically
-- important to make this exception, since otherwise we can
-- have discriminants in array components which don't look
-- side effect free in the case of an array whose index type
-- is an enumeration type with an enumeration rep clause.
-- All other function calls are not side effect free
when N_Function_Call =>
return Nkind (Name (N)) = N_Identifier
and then Is_TSS (Name (N), TSS_Rep_To_Pos)
and then
Side_Effect_Free (First (Parameter_Associations (N)));
-- An indexed component is side effect free if it is a side
-- effect free prefixed reference and all the indexing
-- expressions are side effect free.
when N_Indexed_Component =>
return Side_Effect_Free (Expressions (N))
and then Safe_Prefixed_Reference (N);
-- A type qualification is side effect free if the expression
-- is side effect free.
when N_Qualified_Expression =>
return Side_Effect_Free (Expression (N));
-- A selected component is side effect free only if it is a
-- side effect free prefixed reference.
when N_Selected_Component =>
return Safe_Prefixed_Reference (N);
-- A range is side effect free if the bounds are side effect free
when N_Range =>
return Side_Effect_Free (Low_Bound (N))
and then Side_Effect_Free (High_Bound (N));
-- A slice is side effect free if it is a side effect free
-- prefixed reference and the bounds are side effect free.
when N_Slice =>
return Side_Effect_Free (Discrete_Range (N))
and then Safe_Prefixed_Reference (N);
-- A type conversion is side effect free if the expression
-- to be converted is side effect free.
when N_Type_Conversion =>
return Side_Effect_Free (Expression (N));
-- A unary operator is side effect free if the operand
-- is side effect free.
when N_Unary_Op =>
return Side_Effect_Free (Right_Opnd (N));
-- An unchecked type conversion is side effect free only if it
-- is safe and its argument is side effect free.
when N_Unchecked_Type_Conversion =>
return Safe_Unchecked_Type_Conversion (N)
and then Side_Effect_Free (Expression (N));
-- An unchecked expression is side effect free if its expression
-- is side effect free.
when N_Unchecked_Expression =>
return Side_Effect_Free (Expression (N));
-- We consider that anything else has side effects. This is a bit
-- crude, but we are pretty close for most common cases, and we
-- are certainly correct (i.e. we never return True when the
-- answer should be False).
when others =>
return False;
end case;
end Side_Effect_Free;
-- A list is side effect free if all elements of the list are
-- side effect free.
function Side_Effect_Free (L : List_Id) return Boolean is
N : Node_Id;
begin
if L = No_List or else L = Error_List then
return True;
else
N := First (L);
while Present (N) loop
if not Side_Effect_Free (N) then
return False;
else
Next (N);
end if;
end loop;
return True;
end if;
end Side_Effect_Free;
-------------------------
-- Within_In_Parameter --
-------------------------
function Within_In_Parameter (N : Node_Id) return Boolean is
begin
if not Comes_From_Source (N) then
return False;
elsif Is_Entity_Name (N) then
return
Ekind (Entity (N)) = E_In_Parameter;
elsif Nkind (N) = N_Indexed_Component
or else Nkind (N) = N_Selected_Component
then
return Within_In_Parameter (Prefix (N));
else
return False;
end if;
end Within_In_Parameter;
-- Start of processing for Remove_Side_Effects
begin
-- If we are side effect free already or expansion is disabled,
-- there is nothing to do.
if Side_Effect_Free (Exp) or else not Expander_Active then
return;
end if;
-- All this must not have any checks
Scope_Suppress := (others => True);
-- If the expression has the form v.all then we can just capture
-- the pointer, and then do an explicit dereference on the result.
if Nkind (Exp) = N_Explicit_Dereference then
Def_Id :=
Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
Res :=
Make_Explicit_Dereference (Loc, New_Reference_To (Def_Id, Loc));
Insert_Action (Exp,
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Object_Definition =>
New_Reference_To (Etype (Prefix (Exp)), Loc),
Constant_Present => True,
Expression => Relocate_Node (Prefix (Exp))));
-- Similar processing for an unchecked conversion of an expression
-- of the form v.all, where we want the same kind of treatment.
elsif Nkind (Exp) = N_Unchecked_Type_Conversion
and then Nkind (Expression (Exp)) = N_Explicit_Dereference
then
Remove_Side_Effects (Expression (Exp), Variable_Ref);
Scope_Suppress := Svg_Suppress;
return;
-- If this is a type conversion, leave the type conversion and remove
-- the side effects in the expression. This is important in several
-- circumstances: for change of representations, and also when this
-- is a view conversion to a smaller object, where gigi can end up
-- its own temporary of the wrong size.
-- ??? this transformation is inhibited for elementary types that are
-- not involved in a change of representation because it causes
-- regressions that are not fully understood yet.
elsif Nkind (Exp) = N_Type_Conversion
and then (not Is_Elementary_Type (Underlying_Type (Exp_Type))
or else Nkind (Parent (Exp)) = N_Assignment_Statement)
then
Remove_Side_Effects (Expression (Exp), Variable_Ref);
Scope_Suppress := Svg_Suppress;
return;
-- For expressions that denote objects, we can use a renaming scheme.
-- We skip using this if we have a volatile variable and we do not
-- have Nam_Req set true (see comments above for Side_Effect_Free).
-- We also skip this scheme for class-wide expressions in order to
-- avoid recursive expansion (see Expand_N_Object_Renaming_Declaration)
-- If the object is a function call, we need to create a temporary and
-- not a renaming.
-- Note that we could use ordinary object declarations in the case of
-- expressions not appearing as lvalues. That is left as a possible
-- optimization in the future but we prefer to generate renamings
-- right now, since we may indeed be transforming an lvalue.
elsif Is_Object_Reference (Exp)
and then Nkind (Exp) /= N_Function_Call
and then not Variable_Ref
and then (Name_Req
or else not Is_Entity_Name (Exp)
or else not Treat_As_Volatile (Entity (Exp)))
and then not Is_Class_Wide_Type (Exp_Type)
then
Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
if Nkind (Exp) = N_Selected_Component
and then Nkind (Prefix (Exp)) = N_Function_Call
and then Is_Array_Type (Etype (Exp))
then
-- Avoid generating a variable-sized temporary, by generating
-- the renaming declaration just for the function call. The
-- transformation could be refined to apply only when the array
-- component is constrained by a discriminant???
Res :=
Make_Selected_Component (Loc,
Prefix => New_Occurrence_Of (Def_Id, Loc),
Selector_Name => Selector_Name (Exp));
Insert_Action (Exp,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Mark =>
New_Reference_To (Base_Type (Etype (Prefix (Exp))), Loc),
Name => Relocate_Node (Prefix (Exp))));
-- The temporary must be elaborated by gigi, and is of course
-- not to be replaced in-line by the expression it renames,
-- which would defeat the purpose of removing the side-effect.
Set_Is_Renaming_Of_Object (Def_Id, False);
else
Res := New_Reference_To (Def_Id, Loc);
Insert_Action (Exp,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Mark => New_Reference_To (Exp_Type, Loc),
Name => Relocate_Node (Exp)));
Set_Is_Renaming_Of_Object (Def_Id, False);
end if;
-- If it is a scalar type, just make a copy.
elsif Is_Elementary_Type (Exp_Type) then
Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
Set_Etype (Def_Id, Exp_Type);
Res := New_Reference_To (Def_Id, Loc);
E :=
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Object_Definition => New_Reference_To (Exp_Type, Loc),
Constant_Present => True,
Expression => Relocate_Node (Exp));
Set_Assignment_OK (E);
Insert_Action (Exp, E);
-- Always use a renaming for an unchecked conversion
-- If this is an unchecked conversion that Gigi can't handle, make
-- a copy or a use a renaming to capture the value.
elsif Nkind (Exp) = N_Unchecked_Type_Conversion
and then not Safe_Unchecked_Type_Conversion (Exp)
then
if Controlled_Type (Etype (Exp)) then
-- Use a renaming to capture the expression, rather than create
-- a controlled temporary.
Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
Res := New_Reference_To (Def_Id, Loc);
Insert_Action (Exp,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Mark => New_Reference_To (Exp_Type, Loc),
Name => Relocate_Node (Exp)));
else
Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
Set_Etype (Def_Id, Exp_Type);
Res := New_Reference_To (Def_Id, Loc);
E :=
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Object_Definition => New_Reference_To (Exp_Type, Loc),
Constant_Present => not Is_Variable (Exp),
Expression => Relocate_Node (Exp));
Set_Assignment_OK (E);
Insert_Action (Exp, E);
end if;
-- Otherwise we generate a reference to the value
else
Ref_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
Ptr_Typ_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Ref_Type,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present => True,
Subtype_Indication =>
New_Reference_To (Exp_Type, Loc)));
E := Exp;
Insert_Action (Exp, Ptr_Typ_Decl);
Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
Set_Etype (Def_Id, Exp_Type);
Res :=
Make_Explicit_Dereference (Loc,
Prefix => New_Reference_To (Def_Id, Loc));
if Nkind (E) = N_Explicit_Dereference then
New_Exp := Relocate_Node (Prefix (E));
else
E := Relocate_Node (E);
New_Exp := Make_Reference (Loc, E);
end if;
if Nkind (E) = N_Aggregate and then Expansion_Delayed (E) then
Set_Expansion_Delayed (E, False);
Set_Analyzed (E, False);
end if;
Insert_Action (Exp,
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Object_Definition => New_Reference_To (Ref_Type, Loc),
Expression => New_Exp));
end if;
-- Preserve the Assignment_OK flag in all copies, since at least
-- one copy may be used in a context where this flag must be set
-- (otherwise why would the flag be set in the first place).
Set_Assignment_OK (Res, Assignment_OK (Exp));
-- Finally rewrite the original expression and we are done
Rewrite (Exp, Res);
Analyze_And_Resolve (Exp, Exp_Type);
Scope_Suppress := Svg_Suppress;
end Remove_Side_Effects;
------------------------------------
-- Safe_Unchecked_Type_Conversion --
------------------------------------
-- Note: this function knows quite a bit about the exact requirements
-- of Gigi with respect to unchecked type conversions, and its code
-- must be coordinated with any changes in Gigi in this area.
-- The above requirements should be documented in Sinfo ???
function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is
Otyp : Entity_Id;
Ityp : Entity_Id;
Oalign : Uint;
Ialign : Uint;
Pexp : constant Node_Id := Parent (Exp);
begin
-- If the expression is the RHS of an assignment or object declaration
-- we are always OK because there will always be a target.
-- Object renaming declarations, (generated for view conversions of
-- actuals in inlined calls), like object declarations, provide an
-- explicit type, and are safe as well.
if (Nkind (Pexp) = N_Assignment_Statement
and then Expression (Pexp) = Exp)
or else Nkind (Pexp) = N_Object_Declaration
or else Nkind (Pexp) = N_Object_Renaming_Declaration
then
return True;
-- If the expression is the prefix of an N_Selected_Component
-- we should also be OK because GCC knows to look inside the
-- conversion except if the type is discriminated. We assume
-- that we are OK anyway if the type is not set yet or if it is
-- controlled since we can't afford to introduce a temporary in
-- this case.
elsif Nkind (Pexp) = N_Selected_Component
and then Prefix (Pexp) = Exp
then
if No (Etype (Pexp)) then
return True;
else
return
not Has_Discriminants (Etype (Pexp))
or else Is_Constrained (Etype (Pexp));
end if;
end if;
-- Set the output type, this comes from Etype if it is set, otherwise
-- we take it from the subtype mark, which we assume was already
-- fully analyzed.
if Present (Etype (Exp)) then
Otyp := Etype (Exp);
else
Otyp := Entity (Subtype_Mark (Exp));
end if;
-- The input type always comes from the expression, and we assume
-- this is indeed always analyzed, so we can simply get the Etype.
Ityp := Etype (Expression (Exp));
-- Initialize alignments to unknown so far
Oalign := No_Uint;
Ialign := No_Uint;
-- Replace a concurrent type by its corresponding record type
-- and each type by its underlying type and do the tests on those.
-- The original type may be a private type whose completion is a
-- concurrent type, so find the underlying type first.
if Present (Underlying_Type (Otyp)) then
Otyp := Underlying_Type (Otyp);
end if;
if Present (Underlying_Type (Ityp)) then
Ityp := Underlying_Type (Ityp);
end if;
if Is_Concurrent_Type (Otyp) then
Otyp := Corresponding_Record_Type (Otyp);
end if;
if Is_Concurrent_Type (Ityp) then
Ityp := Corresponding_Record_Type (Ityp);
end if;
-- If the base types are the same, we know there is no problem since
-- this conversion will be a noop.
if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then
return True;
-- If the size of output type is known at compile time, there is
-- never a problem. Note that unconstrained records are considered
-- to be of known size, but we can't consider them that way here,
-- because we are talking about the actual size of the object.
-- We also make sure that in addition to the size being known, we do
-- not have a case which might generate an embarrassingly large temp
-- in stack checking mode.
elsif Size_Known_At_Compile_Time (Otyp)
and then not May_Generate_Large_Temp (Otyp)
and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp))
then
return True;
-- If either type is tagged, then we know the alignment is OK so
-- Gigi will be able to use pointer punning.
elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then
return True;
-- If either type is a limited record type, we cannot do a copy, so
-- say safe since there's nothing else we can do.
elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then
return True;
-- Conversions to and from packed array types are always ignored and
-- hence are safe.
elsif Is_Packed_Array_Type (Otyp)
or else Is_Packed_Array_Type (Ityp)
then
return True;
end if;
-- The only other cases known to be safe is if the input type's
-- alignment is known to be at least the maximum alignment for the
-- target or if both alignments are known and the output type's
-- alignment is no stricter than the input's. We can use the alignment
-- of the component type of an array if a type is an unpacked
-- array type.
if Present (Alignment_Clause (Otyp)) then
Oalign := Expr_Value (Expression (Alignment_Clause (Otyp)));
elsif Is_Array_Type (Otyp)
and then Present (Alignment_Clause (Component_Type (Otyp)))
then
Oalign := Expr_Value (Expression (Alignment_Clause
(Component_Type (Otyp))));
end if;
if Present (Alignment_Clause (Ityp)) then
Ialign := Expr_Value (Expression (Alignment_Clause (Ityp)));
elsif Is_Array_Type (Ityp)
and then Present (Alignment_Clause (Component_Type (Ityp)))
then
Ialign := Expr_Value (Expression (Alignment_Clause
(Component_Type (Ityp))));
end if;
if Ialign /= No_Uint and then Ialign > Maximum_Alignment then
return True;
elsif Ialign /= No_Uint and then Oalign /= No_Uint
and then Ialign <= Oalign
then
return True;
-- Otherwise, Gigi cannot handle this and we must make a temporary.
else
return False;
end if;
end Safe_Unchecked_Type_Conversion;
--------------------------
-- Set_Elaboration_Flag --
--------------------------
procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
Ent : constant Entity_Id := Elaboration_Entity (Spec_Id);
Asn : Node_Id;
begin
if Present (Ent) then
-- Nothing to do if at the compilation unit level, because in this
-- case the flag is set by the binder generated elaboration routine.
if Nkind (Parent (N)) = N_Compilation_Unit then
null;
-- Here we do need to generate an assignment statement
else
Check_Restriction (No_Elaboration_Code, N);
Asn :=
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Ent, Loc),
Expression => New_Occurrence_Of (Standard_True, Loc));
if Nkind (Parent (N)) = N_Subunit then
Insert_After (Corresponding_Stub (Parent (N)), Asn);
else
Insert_After (N, Asn);
end if;
Analyze (Asn);
-- Kill current value indication. This is necessary because
-- the tests of this flag are inserted out of sequence and must
-- not pick up bogus indications of the wrong constant value.
Set_Current_Value (Ent, Empty);
end if;
end if;
end Set_Elaboration_Flag;
--------------------------
-- Target_Has_Fixed_Ops --
--------------------------
Integer_Sized_Small : Ureal;
-- Set to 2.0 ** -(Integer'Size - 1) the first time that this
-- function is called (we don't want to compute it more than once!)
Long_Integer_Sized_Small : Ureal;
-- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this
-- functoin is called (we don't want to compute it more than once)
First_Time_For_THFO : Boolean := True;
-- Set to False after first call (if Fractional_Fixed_Ops_On_Target)
function Target_Has_Fixed_Ops
(Left_Typ : Entity_Id;
Right_Typ : Entity_Id;
Result_Typ : Entity_Id)
return Boolean
is
function Is_Fractional_Type (Typ : Entity_Id) return Boolean;
-- Return True if the given type is a fixed-point type with a small
-- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have
-- an absolute value less than 1.0. This is currently limited
-- to fixed-point types that map to Integer or Long_Integer.
------------------------
-- Is_Fractional_Type --
------------------------
function Is_Fractional_Type (Typ : Entity_Id) return Boolean is
begin
if Esize (Typ) = Standard_Integer_Size then
return Small_Value (Typ) = Integer_Sized_Small;
elsif Esize (Typ) = Standard_Long_Integer_Size then
return Small_Value (Typ) = Long_Integer_Sized_Small;
else
return False;
end if;
end Is_Fractional_Type;
-- Start of processing for Target_Has_Fixed_Ops
begin
-- Return False if Fractional_Fixed_Ops_On_Target is false
if not Fractional_Fixed_Ops_On_Target then
return False;
end if;
-- Here the target has Fractional_Fixed_Ops, if first time, compute
-- standard constants used by Is_Fractional_Type.
if First_Time_For_THFO then
First_Time_For_THFO := False;
Integer_Sized_Small :=
UR_From_Components
(Num => Uint_1,
Den => UI_From_Int (Standard_Integer_Size - 1),
Rbase => 2);
Long_Integer_Sized_Small :=
UR_From_Components
(Num => Uint_1,
Den => UI_From_Int (Standard_Long_Integer_Size - 1),
Rbase => 2);
end if;
-- Return True if target supports fixed-by-fixed multiply/divide
-- for fractional fixed-point types (see Is_Fractional_Type) and
-- the operand and result types are equivalent fractional types.
return Is_Fractional_Type (Base_Type (Left_Typ))
and then Is_Fractional_Type (Base_Type (Right_Typ))
and then Is_Fractional_Type (Base_Type (Result_Typ))
and then Esize (Left_Typ) = Esize (Right_Typ)
and then Esize (Left_Typ) = Esize (Result_Typ);
end Target_Has_Fixed_Ops;
------------------------------------------
-- Type_May_Have_Bit_Aligned_Components --
------------------------------------------
function Type_May_Have_Bit_Aligned_Components
(Typ : Entity_Id) return Boolean
is
begin
-- Array type, check component type
if Is_Array_Type (Typ) then
return
Type_May_Have_Bit_Aligned_Components (Component_Type (Typ));
-- Record type, check components
elsif Is_Record_Type (Typ) then
declare
E : Entity_Id;
begin
E := First_Entity (Typ);
while Present (E) loop
if Ekind (E) = E_Component
or else Ekind (E) = E_Discriminant
then
if Component_May_Be_Bit_Aligned (E)
or else
Type_May_Have_Bit_Aligned_Components (Etype (E))
then
return True;
end if;
end if;
Next_Entity (E);
end loop;
return False;
end;
-- Type other than array or record is always OK
else
return False;
end if;
end Type_May_Have_Bit_Aligned_Components;
----------------------------
-- Wrap_Cleanup_Procedure --
----------------------------
procedure Wrap_Cleanup_Procedure (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Stseq : constant Node_Id := Handled_Statement_Sequence (N);
Stmts : constant List_Id := Statements (Stseq);
begin
if Abort_Allowed then
Prepend_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
Append_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer));
end if;
end Wrap_Cleanup_Procedure;
end Exp_Util;