Google Git
Sign in
gnu / gcc / 82b61df521d17a96f60e56ede06a55a8894b1c2e / . / gcc / ada / sem_ch13.adb
blob: f15850a3b4b5f65bd0c62f1627ec6883f13ac0b5 [file] [log] [blame]
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 1 3 --
-- --
-- B o d y --
-- --
-- $Revision: 1.3 $
-- --
-- Copyright (C) 1992-2001, 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. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Checks; use Checks;
with Einfo; use Einfo;
with Errout; use Errout;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Hostparm; use Hostparm;
with Lib; use Lib;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Ch8; use Sem_Ch8;
with Sem_Eval; use Sem_Eval;
with Sem_Res; use Sem_Res;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Table;
with Ttypes; use Ttypes;
with Tbuild; use Tbuild;
with Urealp; use Urealp;
with GNAT.Heap_Sort_A; use GNAT.Heap_Sort_A;
package body Sem_Ch13 is
SSU : constant Pos := System_Storage_Unit;
-- Convenient short hand for commonly used constant
-----------------------
-- Local Subprograms --
-----------------------
procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
-- This routine is called after setting the Esize of type entity Typ.
-- The purpose is to deal with the situation where an aligment has been
-- inherited from a derived type that is no longer appropriate for the
-- new Esize value. In this case, we reset the Alignment to unknown.
procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
-- Given two entities for record components or discriminants, checks
-- if they hav overlapping component clauses and issues errors if so.
function Get_Alignment_Value (Expr : Node_Id) return Uint;
-- Given the expression for an alignment value, returns the corresponding
-- Uint value. If the value is inappropriate, then error messages are
-- posted as required, and a value of No_Uint is returned.
function Is_Operational_Item (N : Node_Id) return Boolean;
-- A specification for a stream attribute is allowed before the full
-- type is declared, as explained in AI-00137 and the corrigendum.
-- Attributes that do not specify a representation characteristic are
-- operational attributes.
procedure New_Stream_Function
(N : Node_Id;
Ent : Entity_Id;
Subp : Entity_Id;
Nam : Name_Id);
-- Create a function renaming of a given stream attribute to the
-- designated subprogram and then in the tagged case, provide this as
-- a primitive operation, or in the non-tagged case make an appropriate
-- TSS entry. Used for Input. This is more properly an expansion activity
-- than just semantics, but the presence of user-defined stream functions
-- for limited types is a legality check, which is why this takes place
-- here rather than in exp_ch13, where it was previously.
procedure New_Stream_Procedure
(N : Node_Id;
Ent : Entity_Id;
Subp : Entity_Id;
Nam : Name_Id;
Out_P : Boolean := False);
-- Create a procedure renaming of a given stream attribute to the
-- designated subprogram and then in the tagged case, provide this as
-- a primitive operation, or in the non-tagged case make an appropriate
-- TSS entry. Used for Read, Output, Write.
procedure Check_Constant_Address_Clause (Expr : Node_Id; U_Ent : Entity_Id);
-- Expr is an expression for an address clause. This procedure checks
-- that the expression is constant, in the limited sense that it is safe
-- to evaluate it at the point the object U_Ent is declared, rather than
-- at the point of the address clause. The condition for this to be true
-- is that the expression has no variables, no constants declared after
-- U_Ent, and no calls to non-pure functions. If this condition is not
-- met, then an appropriate error message is posted.
procedure Warn_Overlay
(Expr : Node_Id;
Typ : Entity_Id;
Nam : Node_Id);
-- Expr is the expression for an address clause for entity Nam whose type
-- is Typ. If Typ has a default initialization, check whether the address
-- clause might overlay two entities, and emit a warning on the side effect
-- that the initialization will cause.
----------------------------------------------
-- Table for Validate_Unchecked_Conversions --
----------------------------------------------
-- The following table collects unchecked conversions for validation.
-- Entries are made by Validate_Unchecked_Conversion and then the
-- call to Validate_Unchecked_Conversions does the actual error
-- checking and posting of warnings. The reason for this delayed
-- processing is to take advantage of back-annotations of size and
-- alignment values peformed by the back end.
type UC_Entry is record
Enode : Node_Id; -- node used for posting warnings
Source : Entity_Id; -- source type for unchecked conversion
Target : Entity_Id; -- target type for unchecked conversion
end record;
package Unchecked_Conversions is new Table.Table (
Table_Component_Type => UC_Entry,
Table_Index_Type => Int,
Table_Low_Bound => 1,
Table_Initial => 50,
Table_Increment => 200,
Table_Name => "Unchecked_Conversions");
--------------------------------------
-- Alignment_Check_For_Esize_Change --
--------------------------------------
procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
begin
-- If the alignment is known, and not set by a rep clause, and is
-- inconsistent with the size being set, then reset it to unknown,
-- we assume in this case that the size overrides the inherited
-- alignment, and that the alignment must be recomputed.
if Known_Alignment (Typ)
and then not Has_Alignment_Clause (Typ)
and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
then
Init_Alignment (Typ);
end if;
end Alignment_Check_For_Esize_Change;
-----------------------
-- Analyze_At_Clause --
-----------------------
-- An at clause is replaced by the corresponding Address attribute
-- definition clause that is the preferred approach in Ada 95.
procedure Analyze_At_Clause (N : Node_Id) is
begin
Rewrite (N,
Make_Attribute_Definition_Clause (Sloc (N),
Name => Identifier (N),
Chars => Name_Address,
Expression => Expression (N)));
Analyze_Attribute_Definition_Clause (N);
end Analyze_At_Clause;
-----------------------------------------
-- Analyze_Attribute_Definition_Clause --
-----------------------------------------
procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Nam : constant Node_Id := Name (N);
Attr : constant Name_Id := Chars (N);
Expr : constant Node_Id := Expression (N);
Id : constant Attribute_Id := Get_Attribute_Id (Attr);
Ent : Entity_Id;
U_Ent : Entity_Id;
FOnly : Boolean := False;
-- Reset to True for subtype specific attribute (Alignment, Size)
-- and for stream attributes, i.e. those cases where in the call
-- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
-- rules are checked. Note that the case of stream attributes is not
-- clear from the RM, but see AI95-00137. Also, the RM seems to
-- disallow Storage_Size for derived task types, but that is also
-- clearly unintentional.
begin
Analyze (Nam);
Ent := Entity (Nam);
if Rep_Item_Too_Early (Ent, N) then
return;
end if;
-- Rep clause applies to full view of incomplete type or private type
-- if we have one (if not, this is a premature use of the type).
-- However, certain semantic checks need to be done on the specified
-- entity (i.e. the private view), so we save it in Ent.
if Is_Private_Type (Ent)
and then Is_Derived_Type (Ent)
and then not Is_Tagged_Type (Ent)
and then No (Full_View (Ent))
then
-- If this is a private type whose completion is a derivation
-- from another private type, there is no full view, and the
-- attribute belongs to the type itself, not its underlying parent.
U_Ent := Ent;
elsif Ekind (Ent) = E_Incomplete_Type then
Ent := Underlying_Type (Ent);
U_Ent := Ent;
else
U_Ent := Underlying_Type (Ent);
end if;
-- Complete other routine error checks
if Etype (Nam) = Any_Type then
return;
elsif Scope (Ent) /= Current_Scope then
Error_Msg_N ("entity must be declared in this scope", Nam);
return;
elsif Is_Type (U_Ent)
and then not Is_First_Subtype (U_Ent)
and then Id /= Attribute_Object_Size
and then Id /= Attribute_Value_Size
and then not From_At_Mod (N)
then
Error_Msg_N ("cannot specify attribute for subtype", Nam);
return;
end if;
-- Switch on particular attribute
case Id is
-------------
-- Address --
-------------
-- Address attribute definition clause
when Attribute_Address => Address : begin
Analyze_And_Resolve (Expr, RTE (RE_Address));
if Present (Address_Clause (U_Ent)) then
Error_Msg_N ("address already given for &", Nam);
-- Case of address clause for subprogram
elsif Is_Subprogram (U_Ent) then
if Has_Homonym (U_Ent) then
Error_Msg_N
("address clause cannot be given " &
"for overloaded subprogram",
Nam);
end if;
-- For subprograms, all address clauses are permitted,
-- and we mark the subprogram as having a deferred freeze
-- so that Gigi will not elaborate it too soon.
-- Above needs more comments, what is too soon about???
Set_Has_Delayed_Freeze (U_Ent);
-- Case of address clause for entry
elsif Ekind (U_Ent) = E_Entry then
if Nkind (Parent (N)) = N_Task_Body then
Error_Msg_N
("entry address must be specified in task spec", Nam);
end if;
-- For entries, we require a constant address
Check_Constant_Address_Clause (Expr, U_Ent);
-- Case of address clause for an object
elsif
Ekind (U_Ent) = E_Variable
or else
Ekind (U_Ent) = E_Constant
then
declare
Decl : constant Node_Id := Declaration_Node (U_Ent);
Expr : constant Node_Id := Expression (N);
Typ : constant Entity_Id := Etype (U_Ent);
begin
-- Exported variables cannot have an address clause,
-- because this cancels the effect of the pragma Export
if Is_Exported (U_Ent) then
Error_Msg_N
("cannot export object with address clause", Nam);
-- Imported variables can have an address clause, but then
-- the import is pretty meaningless except to suppress
-- initializations, so we do not need such variables to
-- be statically allocated (and in fact it causes trouble
-- if the address clause is a local value).
elsif Is_Imported (U_Ent) then
Set_Is_Statically_Allocated (U_Ent, False);
end if;
-- We mark a possible modification of a variable with an
-- address clause, since it is likely aliasing is occurring.
Note_Possible_Modification (Nam);
-- If we have no initialization of any kind, then we can
-- safely defer the elaboration of the variable to its
-- freezing point, so that the address clause will be
-- computed at the proper point.
-- The same processing applies to all initialized scalar
-- types and all access types. Packed bit arrays of size
-- up to 64 are represented using a modular type with an
-- initialization (to zero) and can be processed like
-- other initialized scalar types.
if (No (Expression (Decl))
and then not Has_Non_Null_Base_Init_Proc (Typ))
or else
(Present (Expression (Decl))
and then Is_Scalar_Type (Typ))
or else
Is_Access_Type (Typ)
or else
(Is_Bit_Packed_Array (Base_Type (Typ))
and then
Is_Modular_Integer_Type (Packed_Array_Type (Typ)))
then
Set_Has_Delayed_Freeze (U_Ent);
-- Otherwise, we require the address clause to be constant
else
Check_Constant_Address_Clause (Expr, U_Ent);
end if;
if Is_Exported (U_Ent) then
Error_Msg_N
("& cannot be exported if an address clause is given",
Nam);
Error_Msg_N
("\define and export a variable " &
"that holds its address instead",
Nam);
end if;
if not Error_Posted (Expr) then
Warn_Overlay (Expr, Typ, Nam);
end if;
-- If entity has delayed freeze then we will generate
-- an alignment check at the freeze point. If there is
-- no delayed freeze we can do it right now.
if not Has_Delayed_Freeze (U_Ent) then
Apply_Alignment_Check (U_Ent, N);
end if;
-- Kill the size check code, since we are not allocating
-- the variable, it is somewhere else.
Kill_Size_Check_Code (U_Ent);
end;
-- Not a valid entity for an address clause
else
Error_Msg_N ("address cannot be given for &", Nam);
end if;
end Address;
---------------
-- Alignment --
---------------
-- Alignment attribute definition clause
when Attribute_Alignment => Alignment_Block : declare
Align : Uint := Get_Alignment_Value (Expr);
begin
FOnly := True;
if not Is_Type (U_Ent)
and then Ekind (U_Ent) /= E_Variable
and then Ekind (U_Ent) /= E_Constant
then
Error_Msg_N ("alignment cannot be given for &", Nam);
elsif Has_Alignment_Clause (U_Ent) then
Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
Error_Msg_N ("alignment clause previously given#", N);
elsif Align /= No_Uint then
Set_Has_Alignment_Clause (U_Ent);
Set_Alignment (U_Ent, Align);
end if;
end Alignment_Block;
---------------
-- Bit_Order --
---------------
-- Bit_Order attribute definition clause
when Attribute_Bit_Order => Bit_Order : declare
begin
if not Is_Record_Type (U_Ent) then
Error_Msg_N
("Bit_Order can only be defined for record type", Nam);
else
Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
if Etype (Expr) = Any_Type then
return;
elsif not Is_Static_Expression (Expr) then
Error_Msg_N ("Bit_Order requires static expression", Expr);
else
if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
Set_Reverse_Bit_Order (U_Ent, True);
end if;
end if;
end if;
end Bit_Order;
--------------------
-- Component_Size --
--------------------
-- Component_Size attribute definition clause
when Attribute_Component_Size => Component_Size_Case : declare
Csize : constant Uint := Static_Integer (Expr);
Btype : Entity_Id;
Biased : Boolean;
New_Ctyp : Entity_Id;
Decl : Node_Id;
begin
if not Is_Array_Type (U_Ent) then
Error_Msg_N ("component size requires array type", Nam);
return;
end if;
Btype := Base_Type (U_Ent);
if Has_Component_Size_Clause (Btype) then
Error_Msg_N
("component size clase for& previously given", Nam);
elsif Csize /= No_Uint then
Check_Size (Expr, Component_Type (Btype), Csize, Biased);
if Has_Aliased_Components (Btype)
and then Csize < 32
and then Csize /= 8
and then Csize /= 16
then
Error_Msg_N
("component size incorrect for aliased components", N);
return;
end if;
-- For the biased case, build a declaration for a subtype
-- that will be used to represent the biased subtype that
-- reflects the biased representation of components. We need
-- this subtype to get proper conversions on referencing
-- elements of the array.
if Biased then
New_Ctyp :=
Make_Defining_Identifier (Loc,
Chars => New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => New_Ctyp,
Subtype_Indication =>
New_Occurrence_Of (Component_Type (Btype), Loc));
Set_Parent (Decl, N);
Analyze (Decl, Suppress => All_Checks);
Set_Has_Delayed_Freeze (New_Ctyp, False);
Set_Esize (New_Ctyp, Csize);
Set_RM_Size (New_Ctyp, Csize);
Init_Alignment (New_Ctyp);
Set_Has_Biased_Representation (New_Ctyp, True);
Set_Is_Itype (New_Ctyp, True);
Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
Set_Component_Type (Btype, New_Ctyp);
end if;
Set_Component_Size (Btype, Csize);
Set_Has_Component_Size_Clause (Btype, True);
Set_Has_Non_Standard_Rep (Btype, True);
end if;
end Component_Size_Case;
------------------
-- External_Tag --
------------------
when Attribute_External_Tag => External_Tag :
begin
if not Is_Tagged_Type (U_Ent) then
Error_Msg_N ("should be a tagged type", Nam);
end if;
Analyze_And_Resolve (Expr, Standard_String);
if not Is_Static_Expression (Expr) then
Error_Msg_N ("must be a static string", Nam);
end if;
Set_Has_External_Tag_Rep_Clause (U_Ent);
end External_Tag;
-----------
-- Input --
-----------
when Attribute_Input => Input : declare
Subp : Entity_Id := Empty;
I : Interp_Index;
It : Interp;
Pnam : Entity_Id;
function Has_Good_Profile (Subp : Entity_Id) return Boolean;
-- Return true if the entity is a function with an appropriate
-- profile for the Input attribute.
function Has_Good_Profile (Subp : Entity_Id) return Boolean is
F : Entity_Id;
Ok : Boolean := False;
begin
if Ekind (Subp) = E_Function then
F := First_Formal (Subp);
if Present (F) and then No (Next_Formal (F)) then
if Ekind (Etype (F)) = E_Anonymous_Access_Type
and then
Designated_Type (Etype (F)) =
Class_Wide_Type (RTE (RE_Root_Stream_Type))
then
Ok := Base_Type (Etype (Subp)) = Base_Type (Ent);
end if;
end if;
end if;
return Ok;
end Has_Good_Profile;
-- Start of processing for Input attribute definition
begin
FOnly := True;
if not Is_Type (U_Ent) then
Error_Msg_N ("local name must be a subtype", Nam);
return;
else
Pnam := TSS (Base_Type (U_Ent), Name_uInput);
if Present (Pnam)
and then Base_Type (Etype (Pnam)) = Base_Type (U_Ent)
then
Error_Msg_Sloc := Sloc (Pnam);
Error_Msg_N ("input attribute already defined #", Nam);
return;
end if;
end if;
Analyze (Expr);
if Is_Entity_Name (Expr) then
if not Is_Overloaded (Expr) then
if Has_Good_Profile (Entity (Expr)) then
Subp := Entity (Expr);
end if;
else
Get_First_Interp (Expr, I, It);
while Present (It.Nam) loop
if Has_Good_Profile (It.Nam) then
Subp := It.Nam;
exit;
end if;
Get_Next_Interp (I, It);
end loop;
end if;
end if;
if Present (Subp) then
Set_Entity (Expr, Subp);
Set_Etype (Expr, Etype (Subp));
New_Stream_Function (N, U_Ent, Subp, Name_uInput);
else
Error_Msg_N ("incorrect expression for input attribute", Expr);
return;
end if;
end Input;
-------------------
-- Machine_Radix --
-------------------
-- Machine radix attribute definition clause
when Attribute_Machine_Radix => Machine_Radix : declare
Radix : constant Uint := Static_Integer (Expr);
begin
if not Is_Decimal_Fixed_Point_Type (U_Ent) then
Error_Msg_N ("decimal fixed-point type expected for &", Nam);
elsif Has_Machine_Radix_Clause (U_Ent) then
Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
Error_Msg_N ("machine radix clause previously given#", N);
elsif Radix /= No_Uint then
Set_Has_Machine_Radix_Clause (U_Ent);
Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
if Radix = 2 then
null;
elsif Radix = 10 then
Set_Machine_Radix_10 (U_Ent);
else
Error_Msg_N ("machine radix value must be 2 or 10", Expr);
end if;
end if;
end Machine_Radix;
-----------------
-- Object_Size --
-----------------
-- Object_Size attribute definition clause
when Attribute_Object_Size => Object_Size : declare
Size : constant Uint := Static_Integer (Expr);
Biased : Boolean;
begin
if not Is_Type (U_Ent) then
Error_Msg_N ("Object_Size cannot be given for &", Nam);
elsif Has_Object_Size_Clause (U_Ent) then
Error_Msg_N ("Object_Size already given for &", Nam);
else
Check_Size (Expr, U_Ent, Size, Biased);
if Size /= 8
and then
Size /= 16
and then
Size /= 32
and then
UI_Mod (Size, 64) /= 0
then
Error_Msg_N
("Object_Size must be 8, 16, 32, or multiple of 64",
Expr);
end if;
Set_Esize (U_Ent, Size);
Set_Has_Object_Size_Clause (U_Ent);
Alignment_Check_For_Esize_Change (U_Ent);
end if;
end Object_Size;
------------
-- Output --
------------
when Attribute_Output => Output : declare
Subp : Entity_Id := Empty;
I : Interp_Index;
It : Interp;
Pnam : Entity_Id;
function Has_Good_Profile (Subp : Entity_Id) return Boolean;
-- Return true if the entity is a procedure with an
-- appropriate profile for the output attribute.
function Has_Good_Profile (Subp : Entity_Id) return Boolean is
F : Entity_Id;
Ok : Boolean := False;
begin
if Ekind (Subp) = E_Procedure then
F := First_Formal (Subp);
if Present (F) then
if Ekind (Etype (F)) = E_Anonymous_Access_Type
and then
Designated_Type (Etype (F)) =
Class_Wide_Type (RTE (RE_Root_Stream_Type))
then
Next_Formal (F);
Ok := Present (F)
and then Parameter_Mode (F) = E_In_Parameter
and then Base_Type (Etype (F)) = Base_Type (Ent)
and then No (Next_Formal (F));
end if;
end if;
end if;
return Ok;
end Has_Good_Profile;
begin
FOnly := True;
if not Is_Type (U_Ent) then
Error_Msg_N ("local name must be a subtype", Nam);
return;
else
Pnam := TSS (Base_Type (U_Ent), Name_uOutput);
if Present (Pnam)
and then
Base_Type (Etype (Next_Formal (First_Formal (Pnam))))
= Base_Type (U_Ent)
then
Error_Msg_Sloc := Sloc (Pnam);
Error_Msg_N ("output attribute already defined #", Nam);
return;
end if;
end if;
Analyze (Expr);
if Is_Entity_Name (Expr) then
if not Is_Overloaded (Expr) then
if Has_Good_Profile (Entity (Expr)) then
Subp := Entity (Expr);
end if;
else
Get_First_Interp (Expr, I, It);
while Present (It.Nam) loop
if Has_Good_Profile (It.Nam) then
Subp := It.Nam;
exit;
end if;
Get_Next_Interp (I, It);
end loop;
end if;
end if;
if Present (Subp) then
Set_Entity (Expr, Subp);
Set_Etype (Expr, Etype (Subp));
New_Stream_Procedure (N, U_Ent, Subp, Name_uOutput);
else
Error_Msg_N ("incorrect expression for output attribute", Expr);
return;
end if;
end Output;
----------
-- Read --
----------
when Attribute_Read => Read : declare
Subp : Entity_Id := Empty;
I : Interp_Index;
It : Interp;
Pnam : Entity_Id;
function Has_Good_Profile (Subp : Entity_Id) return Boolean;
-- Return true if the entity is a procedure with an appropriate
-- profile for the Read attribute.
function Has_Good_Profile (Subp : Entity_Id) return Boolean is
F : Entity_Id;
Ok : Boolean := False;
begin
if Ekind (Subp) = E_Procedure then
F := First_Formal (Subp);
if Present (F) then
if Ekind (Etype (F)) = E_Anonymous_Access_Type
and then
Designated_Type (Etype (F)) =
Class_Wide_Type (RTE (RE_Root_Stream_Type))
then
Next_Formal (F);
Ok := Present (F)
and then Parameter_Mode (F) = E_Out_Parameter
and then Base_Type (Etype (F)) = Base_Type (Ent)
and then No (Next_Formal (F));
end if;
end if;
end if;
return Ok;
end Has_Good_Profile;
-- Start of processing for Read attribute definition
begin
FOnly := True;
if not Is_Type (U_Ent) then
Error_Msg_N ("local name must be a subtype", Nam);
return;
else
Pnam := TSS (Base_Type (U_Ent), Name_uRead);
if Present (Pnam)
and then Base_Type (Etype (Next_Formal (First_Formal (Pnam))))
= Base_Type (U_Ent)
then
Error_Msg_Sloc := Sloc (Pnam);
Error_Msg_N ("read attribute already defined #", Nam);
return;
end if;
end if;
Analyze (Expr);
if Is_Entity_Name (Expr) then
if not Is_Overloaded (Expr) then
if Has_Good_Profile (Entity (Expr)) then
Subp := Entity (Expr);
end if;
else
Get_First_Interp (Expr, I, It);
while Present (It.Nam) loop
if Has_Good_Profile (It.Nam) then
Subp := It.Nam;
exit;
end if;
Get_Next_Interp (I, It);
end loop;
end if;
end if;
if Present (Subp) then
Set_Entity (Expr, Subp);
Set_Etype (Expr, Etype (Subp));
New_Stream_Procedure (N, U_Ent, Subp, Name_uRead, True);
else
Error_Msg_N ("incorrect expression for read attribute", Expr);
return;
end if;
end Read;
----------
-- Size --
----------
-- Size attribute definition clause
when Attribute_Size => Size : declare
Size : constant Uint := Static_Integer (Expr);
Etyp : Entity_Id;
Biased : Boolean;
begin
FOnly := True;
if Has_Size_Clause (U_Ent) then
Error_Msg_N ("size already given for &", Nam);
elsif not Is_Type (U_Ent)
and then Ekind (U_Ent) /= E_Variable
and then Ekind (U_Ent) /= E_Constant
then
Error_Msg_N ("size cannot be given for &", Nam);
elsif Is_Array_Type (U_Ent)
and then not Is_Constrained (U_Ent)
then
Error_Msg_N
("size cannot be given for unconstrained array", Nam);
elsif Size /= No_Uint then
if Is_Type (U_Ent) then
Etyp := U_Ent;
else
Etyp := Etype (U_Ent);
end if;
-- Check size, note that Gigi is in charge of checking
-- that the size of an array or record type is OK. Also
-- we do not check the size in the ordinary fixed-point
-- case, since it is too early to do so (there may be a
-- subsequent small clause that affects the size). We can
-- check the size if a small clause has already been given.
if not Is_Ordinary_Fixed_Point_Type (U_Ent)
or else Has_Small_Clause (U_Ent)
then
Check_Size (Expr, Etyp, Size, Biased);
Set_Has_Biased_Representation (U_Ent, Biased);
end if;
-- For types set RM_Size and Esize if possible
if Is_Type (U_Ent) then
Set_RM_Size (U_Ent, Size);
-- For scalar types, increase Object_Size to power of 2,
-- but not less than 8 in any case, i.e. byte addressable.
if Is_Scalar_Type (U_Ent) then
if Size <= 8 then
Init_Esize (U_Ent, 8);
elsif Size <= 16 then
Init_Esize (U_Ent, 16);
elsif Size <= 32 then
Init_Esize (U_Ent, 32);
else
Set_Esize (U_Ent, (Size + 63) / 64 * 64);
end if;
-- For all other types, object size = value size. The
-- backend will adjust as needed.
else
Set_Esize (U_Ent, Size);
end if;
Alignment_Check_For_Esize_Change (U_Ent);
-- For objects, set Esize only
else
Set_Esize (U_Ent, Size);
end if;
Set_Has_Size_Clause (U_Ent);
end if;
end Size;
-----------
-- Small --
-----------
-- Small attribute definition clause
when Attribute_Small => Small : declare
Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
Small : Ureal;
begin
Analyze_And_Resolve (Expr, Any_Real);
if Etype (Expr) = Any_Type then
return;
elsif not Is_Static_Expression (Expr) then
Error_Msg_N ("small requires static expression", Expr);
return;
else
Small := Expr_Value_R (Expr);
if Small <= Ureal_0 then
Error_Msg_N ("small value must be greater than zero", Expr);
return;
end if;
end if;
if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
Error_Msg_N
("small requires an ordinary fixed point type", Nam);
elsif Has_Small_Clause (U_Ent) then
Error_Msg_N ("small already given for &", Nam);
elsif Small > Delta_Value (U_Ent) then
Error_Msg_N
("small value must not be greater then delta value", Nam);
else
Set_Small_Value (U_Ent, Small);
Set_Small_Value (Implicit_Base, Small);
Set_Has_Small_Clause (U_Ent);
Set_Has_Small_Clause (Implicit_Base);
Set_Has_Non_Standard_Rep (Implicit_Base);
end if;
end Small;
------------------
-- Storage_Size --
------------------
-- Storage_Size attribute definition clause
when Attribute_Storage_Size => Storage_Size : declare
Btype : constant Entity_Id := Base_Type (U_Ent);
Sprag : Node_Id;
begin
if Is_Task_Type (U_Ent) then
FOnly := True;
end if;
if not Is_Access_Type (U_Ent)
and then Ekind (U_Ent) /= E_Task_Type
then
Error_Msg_N ("storage size cannot be given for &", Nam);
elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
Error_Msg_N
("storage size cannot be given for a derived access type",
Nam);
elsif Has_Storage_Size_Clause (Btype) then
Error_Msg_N ("storage size already given for &", Nam);
else
Analyze_And_Resolve (Expr, Any_Integer);
if Is_Access_Type (U_Ent) then
if Present (Associated_Storage_Pool (U_Ent)) then
Error_Msg_N ("storage pool already given for &", Nam);
return;
end if;
if Compile_Time_Known_Value (Expr)
and then Expr_Value (Expr) = 0
then
Set_No_Pool_Assigned (Btype);
end if;
else -- Is_Task_Type (U_Ent)
Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
if Present (Sprag) then
Error_Msg_Sloc := Sloc (Sprag);
Error_Msg_N
("Storage_Size already specified#", Nam);
return;
end if;
end if;
Set_Has_Storage_Size_Clause (Btype);
end if;
end Storage_Size;
------------------
-- Storage_Pool --
------------------
-- Storage_Pool attribute definition clause
when Attribute_Storage_Pool => Storage_Pool : declare
Pool : Entity_Id;
begin
if Ekind (U_Ent) /= E_Access_Type
and then Ekind (U_Ent) /= E_General_Access_Type
then
Error_Msg_N (
"storage pool can only be given for access types", Nam);
return;
elsif Is_Derived_Type (U_Ent) then
Error_Msg_N
("storage pool cannot be given for a derived access type",
Nam);
elsif Has_Storage_Size_Clause (U_Ent) then
Error_Msg_N ("storage size already given for &", Nam);
return;
elsif Present (Associated_Storage_Pool (U_Ent)) then
Error_Msg_N ("storage pool already given for &", Nam);
return;
end if;
Analyze_And_Resolve
(Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
-- If the argument is a name that is not an entity name, then
-- we construct a renaming operation to define an entity of
-- type storage pool.
if not Is_Entity_Name (Expr)
and then Is_Object_Reference (Expr)
then
Pool :=
Make_Defining_Identifier (Loc,
Chars => New_Internal_Name ('P'));
declare
Rnode : constant Node_Id :=
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Pool,
Subtype_Mark =>
New_Occurrence_Of (Etype (Expr), Loc),
Name => Expr);
begin
Insert_Before (N, Rnode);
Analyze (Rnode);
Set_Associated_Storage_Pool (U_Ent, Pool);
end;
elsif Is_Entity_Name (Expr) then
Pool := Entity (Expr);
-- If pool is a renamed object, get original one. This can
-- happen with an explicit renaming, and within instances.
while Present (Renamed_Object (Pool))
and then Is_Entity_Name (Renamed_Object (Pool))
loop
Pool := Entity (Renamed_Object (Pool));
end loop;
if Present (Renamed_Object (Pool))
and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
then
Pool := Entity (Expression (Renamed_Object (Pool)));
end if;
if Present (Etype (Pool))
and then Etype (Pool) /= RTE (RE_Stack_Bounded_Pool)
and then Etype (Pool) /= RTE (RE_Unbounded_Reclaim_Pool)
then
Set_Associated_Storage_Pool (U_Ent, Pool);
else
Error_Msg_N ("Non sharable GNAT Pool", Expr);
end if;
-- The pool may be specified as the Storage_Pool of some other
-- type. It is rewritten as a class_wide conversion of the
-- corresponding pool entity.
elsif Nkind (Expr) = N_Type_Conversion
and then Is_Entity_Name (Expression (Expr))
and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
then
Pool := Entity (Expression (Expr));
if Present (Etype (Pool))
and then Etype (Pool) /= RTE (RE_Stack_Bounded_Pool)
and then Etype (Pool) /= RTE (RE_Unbounded_Reclaim_Pool)
then
Set_Associated_Storage_Pool (U_Ent, Pool);
else
Error_Msg_N ("Non sharable GNAT Pool", Expr);
end if;
else
Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
return;
end if;
end Storage_Pool;
----------------
-- Value_Size --
----------------
-- Value_Size attribute definition clause
when Attribute_Value_Size => Value_Size : declare
Size : constant Uint := Static_Integer (Expr);
Biased : Boolean;
begin
if not Is_Type (U_Ent) then
Error_Msg_N ("Value_Size cannot be given for &", Nam);
elsif Present
(Get_Attribute_Definition_Clause
(U_Ent, Attribute_Value_Size))
then
Error_Msg_N ("Value_Size already given for &", Nam);
else
if Is_Elementary_Type (U_Ent) then
Check_Size (Expr, U_Ent, Size, Biased);
Set_Has_Biased_Representation (U_Ent, Biased);
end if;
Set_RM_Size (U_Ent, Size);
end if;
end Value_Size;
-----------
-- Write --
-----------
-- Write attribute definition clause
-- check for class-wide case will be performed later
when Attribute_Write => Write : declare
Subp : Entity_Id := Empty;
I : Interp_Index;
It : Interp;
Pnam : Entity_Id;
function Has_Good_Profile (Subp : Entity_Id) return Boolean;
-- Return true if the entity is a procedure with an
-- appropriate profile for the write attribute.
function Has_Good_Profile (Subp : Entity_Id) return Boolean is
F : Entity_Id;
Ok : Boolean := False;
begin
if Ekind (Subp) = E_Procedure then
F := First_Formal (Subp);
if Present (F) then
if Ekind (Etype (F)) = E_Anonymous_Access_Type
and then
Designated_Type (Etype (F)) =
Class_Wide_Type (RTE (RE_Root_Stream_Type))
then
Next_Formal (F);
Ok := Present (F)
and then Parameter_Mode (F) = E_In_Parameter
and then Base_Type (Etype (F)) = Base_Type (Ent)
and then No (Next_Formal (F));
end if;
end if;
end if;
return Ok;
end Has_Good_Profile;
-- Start of processing for Write attribute definition
begin
FOnly := True;
if not Is_Type (U_Ent) then
Error_Msg_N ("local name must be a subtype", Nam);
return;
end if;
Pnam := TSS (Base_Type (U_Ent), Name_uWrite);
if Present (Pnam)
and then Base_Type (Etype (Next_Formal (First_Formal (Pnam))))
= Base_Type (U_Ent)
then
Error_Msg_Sloc := Sloc (Pnam);
Error_Msg_N ("write attribute already defined #", Nam);
return;
end if;
Analyze (Expr);
if Is_Entity_Name (Expr) then
if not Is_Overloaded (Expr) then
if Has_Good_Profile (Entity (Expr)) then
Subp := Entity (Expr);
end if;
else
Get_First_Interp (Expr, I, It);
while Present (It.Nam) loop
if Has_Good_Profile (It.Nam) then
Subp := It.Nam;
exit;
end if;
Get_Next_Interp (I, It);
end loop;
end if;
end if;
if Present (Subp) then
Set_Entity (Expr, Subp);
Set_Etype (Expr, Etype (Subp));
New_Stream_Procedure (N, U_Ent, Subp, Name_uWrite);
else
Error_Msg_N ("incorrect expression for write attribute", Expr);
return;
end if;
end Write;
-- All other attributes cannot be set
when others =>
Error_Msg_N
("attribute& cannot be set with definition clause", N);
end case;
-- The test for the type being frozen must be performed after
-- any expression the clause has been analyzed since the expression
-- itself might cause freezing that makes the clause illegal.
if Rep_Item_Too_Late (U_Ent, N, FOnly) then
return;
end if;
end Analyze_Attribute_Definition_Clause;
----------------------------
-- Analyze_Code_Statement --
----------------------------
procedure Analyze_Code_Statement (N : Node_Id) is
HSS : constant Node_Id := Parent (N);
SBody : constant Node_Id := Parent (HSS);
Subp : constant Entity_Id := Current_Scope;
Stmt : Node_Id;
Decl : Node_Id;
StmtO : Node_Id;
DeclO : Node_Id;
begin
-- Analyze and check we get right type, note that this implements the
-- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
-- is the only way that Asm_Insn could possibly be visible.
Analyze_And_Resolve (Expression (N));
if Etype (Expression (N)) = Any_Type then
return;
elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
Error_Msg_N ("incorrect type for code statement", N);
return;
end if;
-- Make sure we appear in the handled statement sequence of a
-- subprogram (RM 13.8(3)).
if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
or else Nkind (SBody) /= N_Subprogram_Body
then
Error_Msg_N
("code statement can only appear in body of subprogram", N);
return;
end if;
-- Do remaining checks (RM 13.8(3)) if not already done
if not Is_Machine_Code_Subprogram (Subp) then
Set_Is_Machine_Code_Subprogram (Subp);
-- No exception handlers allowed
if Present (Exception_Handlers (HSS)) then
Error_Msg_N
("exception handlers not permitted in machine code subprogram",
First (Exception_Handlers (HSS)));
end if;
-- No declarations other than use clauses and pragmas (we allow
-- certain internally generated declarations as well).
Decl := First (Declarations (SBody));
while Present (Decl) loop
DeclO := Original_Node (Decl);
if Comes_From_Source (DeclO)
and then Nkind (DeclO) /= N_Pragma
and then Nkind (DeclO) /= N_Use_Package_Clause
and then Nkind (DeclO) /= N_Use_Type_Clause
and then Nkind (DeclO) /= N_Implicit_Label_Declaration
then
Error_Msg_N
("this declaration not allowed in machine code subprogram",
DeclO);
end if;
Next (Decl);
end loop;
-- No statements other than code statements, pragmas, and labels.
-- Again we allow certain internally generated statements.
Stmt := First (Statements (HSS));
while Present (Stmt) loop
StmtO := Original_Node (Stmt);
if Comes_From_Source (StmtO)
and then Nkind (StmtO) /= N_Pragma
and then Nkind (StmtO) /= N_Label
and then Nkind (StmtO) /= N_Code_Statement
then
Error_Msg_N
("this statement is not allowed in machine code subprogram",
StmtO);
end if;
Next (Stmt);
end loop;
end if;
end Analyze_Code_Statement;
-----------------------------------------------
-- Analyze_Enumeration_Representation_Clause --
-----------------------------------------------
procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
Ident : constant Node_Id := Identifier (N);
Aggr : constant Node_Id := Array_Aggregate (N);
Enumtype : Entity_Id;
Elit : Entity_Id;
Expr : Node_Id;
Assoc : Node_Id;
Choice : Node_Id;
Val : Uint;
Err : Boolean := False;
Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
Min : Uint;
Max : Uint;
begin
-- First some basic error checks
Find_Type (Ident);
Enumtype := Entity (Ident);
if Enumtype = Any_Type
or else Rep_Item_Too_Early (Enumtype, N)
then
return;
else
Enumtype := Underlying_Type (Enumtype);
end if;
if not Is_Enumeration_Type (Enumtype) then
Error_Msg_NE
("enumeration type required, found}",
Ident, First_Subtype (Enumtype));
return;
end if;
if Scope (Enumtype) /= Current_Scope then
Error_Msg_N ("type must be declared in this scope", Ident);
return;
elsif not Is_First_Subtype (Enumtype) then
Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
return;
elsif Has_Enumeration_Rep_Clause (Enumtype) then
Error_Msg_N ("duplicate enumeration rep clause ignored", N);
return;
elsif Root_Type (Enumtype) = Standard_Character
or else Root_Type (Enumtype) = Standard_Wide_Character
then
Error_Msg_N ("enumeration rep clause not allowed for this type", N);
else
Set_Has_Enumeration_Rep_Clause (Enumtype);
Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
end if;
-- Now we process the aggregate. Note that we don't use the normal
-- aggregate code for this purpose, because we don't want any of the
-- normal expansion activities, and a number of special semantic
-- rules apply (including the component type being any integer type)
-- Badent signals that we found some incorrect entries processing
-- the list. The final checks for completeness and ordering are
-- skipped in this case.
Elit := First_Literal (Enumtype);
-- First the positional entries if any
if Present (Expressions (Aggr)) then
Expr := First (Expressions (Aggr));
while Present (Expr) loop
if No (Elit) then
Error_Msg_N ("too many entries in aggregate", Expr);
return;
end if;
Val := Static_Integer (Expr);
if Val = No_Uint then
Err := True;
elsif Val < Lo or else Hi < Val then
Error_Msg_N ("value outside permitted range", Expr);
Err := True;
end if;
Set_Enumeration_Rep (Elit, Val);
Set_Enumeration_Rep_Expr (Elit, Expr);
Next (Expr);
Next (Elit);
end loop;
end if;
-- Now process the named entries if present
if Present (Component_Associations (Aggr)) then
Assoc := First (Component_Associations (Aggr));
while Present (Assoc) loop
Choice := First (Choices (Assoc));
if Present (Next (Choice)) then
Error_Msg_N
("multiple choice not allowed here", Next (Choice));
Err := True;
end if;
if Nkind (Choice) = N_Others_Choice then
Error_Msg_N ("others choice not allowed here", Choice);
Err := True;
elsif Nkind (Choice) = N_Range then
-- ??? should allow zero/one element range here
Error_Msg_N ("range not allowed here", Choice);
Err := True;
else
Analyze_And_Resolve (Choice, Enumtype);
if Is_Entity_Name (Choice)
and then Is_Type (Entity (Choice))
then
Error_Msg_N ("subtype name not allowed here", Choice);
Err := True;
-- ??? should allow static subtype with zero/one entry
elsif Etype (Choice) = Base_Type (Enumtype) then
if not Is_Static_Expression (Choice) then
Error_Msg_N
("non-static expression used for choice", Choice);
Err := True;
else
Elit := Expr_Value_E (Choice);
if Present (Enumeration_Rep_Expr (Elit)) then
Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
Error_Msg_NE
("representation for& previously given#",
Choice, Elit);
Err := True;
end if;
Set_Enumeration_Rep_Expr (Elit, Choice);
Expr := Expression (Assoc);
Val := Static_Integer (Expr);
if Val = No_Uint then
Err := True;
elsif Val < Lo or else Hi < Val then
Error_Msg_N ("value outside permitted range", Expr);
Err := True;
end if;
Set_Enumeration_Rep (Elit, Val);
end if;
end if;
end if;
Next (Assoc);
end loop;
end if;
-- Aggregate is fully processed. Now we check that a full set of
-- representations was given, and that they are in range and in order.
-- These checks are only done if no other errors occurred.
if not Err then
Min := No_Uint;
Max := No_Uint;
Elit := First_Literal (Enumtype);
while Present (Elit) loop
if No (Enumeration_Rep_Expr (Elit)) then
Error_Msg_NE ("missing representation for&!", N, Elit);
else
Val := Enumeration_Rep (Elit);
if Min = No_Uint then
Min := Val;
end if;
if Val /= No_Uint then
if Max /= No_Uint and then Val <= Max then
Error_Msg_NE
("enumeration value for& not ordered!",
Enumeration_Rep_Expr (Elit), Elit);
end if;
Max := Val;
end if;
-- If there is at least one literal whose representation
-- is not equal to the Pos value, then note that this
-- enumeration type has a non-standard representation.
if Val /= Enumeration_Pos (Elit) then
Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
end if;
end if;
Next (Elit);
end loop;
-- Now set proper size information
declare
Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
begin
if Has_Size_Clause (Enumtype) then
if Esize (Enumtype) >= Minsize then
null;
else
Minsize :=
UI_From_Int (Minimum_Size (Enumtype, Biased => True));
if Esize (Enumtype) < Minsize then
Error_Msg_N ("previously given size is too small", N);
else
Set_Has_Biased_Representation (Enumtype);
end if;
end if;
else
Set_RM_Size (Enumtype, Minsize);
Set_Enum_Esize (Enumtype);
end if;
Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
end;
end if;
-- We repeat the too late test in case it froze itself!
if Rep_Item_Too_Late (Enumtype, N) then
null;
end if;
end Analyze_Enumeration_Representation_Clause;
----------------------------
-- Analyze_Free_Statement --
----------------------------
procedure Analyze_Free_Statement (N : Node_Id) is
begin
Analyze (Expression (N));
end Analyze_Free_Statement;
------------------------------------------
-- Analyze_Record_Representation_Clause --
------------------------------------------
procedure Analyze_Record_Representation_Clause (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Ident : constant Node_Id := Identifier (N);
Rectype : Entity_Id;
Fent : Entity_Id;
CC : Node_Id;
Posit : Uint;
Fbit : Uint;
Lbit : Uint;
Hbit : Uint := Uint_0;
Comp : Entity_Id;
Ocomp : Entity_Id;
Biased : Boolean;
Max_Bit_So_Far : Uint;
-- Records the maximum bit position so far. If all field positoins
-- are monotonically increasing, then we can skip the circuit for
-- checking for overlap, since no overlap is possible.
Overlap_Check_Required : Boolean;
-- Used to keep track of whether or not an overlap check is required
Ccount : Natural := 0;
-- Number of component clauses in record rep clause
begin
Find_Type (Ident);
Rectype := Entity (Ident);
if Rectype = Any_Type
or else Rep_Item_Too_Early (Rectype, N)
then
return;
else
Rectype := Underlying_Type (Rectype);
end if;
-- First some basic error checks
if not Is_Record_Type (Rectype) then
Error_Msg_NE
("record type required, found}", Ident, First_Subtype (Rectype));
return;
elsif Is_Unchecked_Union (Rectype) then
Error_Msg_N
("record rep clause not allowed for Unchecked_Union", N);
elsif Scope (Rectype) /= Current_Scope then
Error_Msg_N ("type must be declared in this scope", N);
return;
elsif not Is_First_Subtype (Rectype) then
Error_Msg_N ("cannot give record rep clause for subtype", N);
return;
elsif Has_Record_Rep_Clause (Rectype) then
Error_Msg_N ("duplicate record rep clause ignored", N);
return;
elsif Rep_Item_Too_Late (Rectype, N) then
return;
end if;
if Present (Mod_Clause (N)) then
declare
Loc : constant Source_Ptr := Sloc (N);
M : constant Node_Id := Mod_Clause (N);
P : constant List_Id := Pragmas_Before (M);
Mod_Val : Uint;
AtM_Nod : Node_Id;
begin
if Present (P) then
Analyze_List (P);
end if;
-- In Tree_Output mode, expansion is disabled, but we must
-- convert the Mod clause into an alignment clause anyway, so
-- that the back-end can compute and back-annotate properly the
-- size and alignment of types that may include this record.
if Operating_Mode = Check_Semantics
and then Tree_Output
then
AtM_Nod :=
Make_Attribute_Definition_Clause (Loc,
Name => New_Reference_To (Base_Type (Rectype), Loc),
Chars => Name_Alignment,
Expression => Relocate_Node (Expression (M)));
Set_From_At_Mod (AtM_Nod);
Insert_After (N, AtM_Nod);
Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
Set_Mod_Clause (N, Empty);
else
-- Get the alignment value to perform error checking
Mod_Val := Get_Alignment_Value (Expression (M));
end if;
end;
end if;
-- Clear any existing component clauses for the type (this happens
-- with derived types, where we are now overriding the original)
Fent := First_Entity (Rectype);
Comp := Fent;
while Present (Comp) loop
if Ekind (Comp) = E_Component
or else Ekind (Comp) = E_Discriminant
then
Set_Component_Clause (Comp, Empty);
end if;
Next_Entity (Comp);
end loop;
-- All done if no component clauses
CC := First (Component_Clauses (N));
if No (CC) then
return;
end if;
-- If a tag is present, then create a component clause that places
-- it at the start of the record (otherwise gigi may place it after
-- other fields that have rep clauses).
if Nkind (Fent) = N_Defining_Identifier
and then Chars (Fent) = Name_uTag
then
Set_Component_Bit_Offset (Fent, Uint_0);
Set_Normalized_Position (Fent, Uint_0);
Set_Normalized_First_Bit (Fent, Uint_0);
Set_Normalized_Position_Max (Fent, Uint_0);
Init_Esize (Fent, System_Address_Size);
Set_Component_Clause (Fent,
Make_Component_Clause (Loc,
Component_Name =>
Make_Identifier (Loc,
Chars => Name_uTag),
Position =>
Make_Integer_Literal (Loc,
Intval => Uint_0),
First_Bit =>
Make_Integer_Literal (Loc,
Intval => Uint_0),
Last_Bit =>
Make_Integer_Literal (Loc,
UI_From_Int (System_Address_Size))));
Ccount := Ccount + 1;
end if;
Set_Has_Record_Rep_Clause (Rectype);
Set_Has_Specified_Layout (Rectype);
-- A representation like this applies to the base type as well
Set_Has_Record_Rep_Clause (Base_Type (Rectype));
Set_Has_Non_Standard_Rep (Base_Type (Rectype));
Set_Has_Specified_Layout (Base_Type (Rectype));
Max_Bit_So_Far := Uint_Minus_1;
Overlap_Check_Required := False;
-- Process the component clauses
while Present (CC) loop
-- If pragma, just analyze it
if Nkind (CC) = N_Pragma then
Analyze (CC);
-- Processing for real component clause
else
Ccount := Ccount + 1;
Posit := Static_Integer (Position (CC));
Fbit := Static_Integer (First_Bit (CC));
Lbit := Static_Integer (Last_Bit (CC));
if Posit /= No_Uint
and then Fbit /= No_Uint
and then Lbit /= No_Uint
then
if Posit < 0 then
Error_Msg_N
("position cannot be negative", Position (CC));
elsif Fbit < 0 then
Error_Msg_N
("first bit cannot be negative", First_Bit (CC));
-- Values look OK, so find the corresponding record component
-- Even though the syntax allows an attribute reference for
-- implementation-defined components, GNAT does not allow the
-- tag to get an explicit position.
elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
if Attribute_Name (Component_Name (CC)) = Name_Tag then
Error_Msg_N ("position of tag cannot be specified", CC);
else
Error_Msg_N ("illegal component name", CC);
end if;
else
Comp := First_Entity (Rectype);
while Present (Comp) loop
exit when Chars (Comp) = Chars (Component_Name (CC));
Next_Entity (Comp);
end loop;
if No (Comp) then
-- Maybe component of base type that is absent from
-- statically constrained first subtype.
Comp := First_Entity (Base_Type (Rectype));
while Present (Comp) loop
exit when Chars (Comp) = Chars (Component_Name (CC));
Next_Entity (Comp);
end loop;
end if;
if No (Comp) then
Error_Msg_N
("component clause is for non-existent field", CC);
elsif Present (Component_Clause (Comp)) then
Error_Msg_Sloc := Sloc (Component_Clause (Comp));
Error_Msg_N
("component clause previously given#", CC);
else
-- Update Fbit and Lbit to the actual bit number.
Fbit := Fbit + UI_From_Int (SSU) * Posit;
Lbit := Lbit + UI_From_Int (SSU) * Posit;
if Fbit <= Max_Bit_So_Far then
Overlap_Check_Required := True;
else
Max_Bit_So_Far := Lbit;
end if;
if Has_Size_Clause (Rectype)
and then Esize (Rectype) <= Lbit
then
Error_Msg_N
("bit number out of range of specified size",
Last_Bit (CC));
else
Set_Component_Clause (Comp, CC);
Set_Component_Bit_Offset (Comp, Fbit);
Set_Esize (Comp, 1 + (Lbit - Fbit));
Set_Normalized_First_Bit (Comp, Fbit mod SSU);
Set_Normalized_Position (Comp, Fbit / SSU);
Set_Normalized_Position_Max
(Fent, Normalized_Position (Fent));
if Is_Tagged_Type (Rectype)
and then Fbit < System_Address_Size
then
Error_Msg_NE
("component overlaps tag field of&",
CC, Rectype);
end if;
-- Test for large object that is not on a byte
-- boundary, defined as a large packed array not
-- represented by a modular type, or an object for
-- which a size of greater than 64 bits is specified.
if Fbit mod SSU /= 0 then
if (Is_Packed_Array_Type (Etype (Comp))
and then Is_Array_Type
(Packed_Array_Type (Etype (Comp))))
or else Esize (Etype (Comp)) > 64
then
Error_Msg_N
("large component must be on byte boundary",
First_Bit (CC));
end if;
end if;
-- This information is also set in the
-- corresponding component of the base type,
-- found by accessing the Original_Record_Component
-- link if it is present.
Ocomp := Original_Record_Component (Comp);
if Hbit < Lbit then
Hbit := Lbit;
end if;
Check_Size
(Component_Name (CC),
Etype (Comp),
Esize (Comp),
Biased);
Set_Has_Biased_Representation (Comp, Biased);
if Present (Ocomp) then
Set_Component_Clause (Ocomp, CC);
Set_Component_Bit_Offset (Ocomp, Fbit);
Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
Set_Normalized_Position (Ocomp, Fbit / SSU);
Set_Esize (Ocomp, 1 + (Lbit - Fbit));
Set_Normalized_Position_Max
(Ocomp, Normalized_Position (Ocomp));
Set_Has_Biased_Representation
(Ocomp, Has_Biased_Representation (Comp));
end if;
if Esize (Comp) < 0 then
Error_Msg_N ("component size is negative", CC);
end if;
end if;
end if;
end if;
end if;
end if;
Next (CC);
end loop;
-- Now that we have processed all the component clauses, check for
-- overlap. We have to leave this till last, since the components
-- can appear in any arbitrary order in the representation clause.
-- We do not need this check if all specified ranges were monotonic,
-- as recorded by Overlap_Check_Required being False at this stage.
-- This first section checks if there are any overlapping entries
-- at all. It does this by sorting all entries and then seeing if
-- there are any overlaps. If there are none, then that is decisive,
-- but if there are overlaps, they may still be OK (they may result
-- from fields in different variants).
if Overlap_Check_Required then
Overlap_Check1 : declare
OC_Fbit : array (0 .. Ccount) of Uint;
-- First-bit values for component clauses, the value is the
-- offset of the first bit of the field from start of record.
-- The zero entry is for use in sorting.
OC_Lbit : array (0 .. Ccount) of Uint;
-- Last-bit values for component clauses, the value is the
-- offset of the last bit of the field from start of record.
-- The zero entry is for use in sorting.
OC_Count : Natural := 0;
-- Count of entries in OC_Fbit and OC_Lbit
function OC_Lt (Op1, Op2 : Natural) return Boolean;
-- Compare routine for Sort (See GNAT.Heap_Sort_A)
procedure OC_Move (From : Natural; To : Natural);
-- Move routine for Sort (see GNAT.Heap_Sort_A)
function OC_Lt (Op1, Op2 : Natural) return Boolean is
begin
return OC_Fbit (Op1) < OC_Fbit (Op2);
end OC_Lt;
procedure OC_Move (From : Natural; To : Natural) is
begin
OC_Fbit (To) := OC_Fbit (From);
OC_Lbit (To) := OC_Lbit (From);
end OC_Move;
begin
CC := First (Component_Clauses (N));
while Present (CC) loop
if Nkind (CC) /= N_Pragma then
Posit := Static_Integer (Position (CC));
Fbit := Static_Integer (First_Bit (CC));
Lbit := Static_Integer (Last_Bit (CC));
if Posit /= No_Uint
and then Fbit /= No_Uint
and then Lbit /= No_Uint
then
OC_Count := OC_Count + 1;
Posit := Posit * SSU;
OC_Fbit (OC_Count) := Fbit + Posit;
OC_Lbit (OC_Count) := Lbit + Posit;
end if;
end if;
Next (CC);
end loop;
Sort
(OC_Count,
OC_Move'Unrestricted_Access,
OC_Lt'Unrestricted_Access);
Overlap_Check_Required := False;
for J in 1 .. OC_Count - 1 loop
if OC_Lbit (J) >= OC_Fbit (J + 1) then
Overlap_Check_Required := True;
exit;
end if;
end loop;
end Overlap_Check1;
end if;
-- If Overlap_Check_Required is still True, then we have to do
-- the full scale overlap check, since we have at least two fields
-- that do overlap, and we need to know if that is OK since they
-- are in the same variant, or whether we have a definite problem
if Overlap_Check_Required then
Overlap_Check2 : declare
C1_Ent, C2_Ent : Entity_Id;
-- Entities of components being checked for overlap
Clist : Node_Id;
-- Component_List node whose Component_Items are being checked
Citem : Node_Id;
-- Component declaration for component being checked
begin
C1_Ent := First_Entity (Base_Type (Rectype));
-- Loop through all components in record. For each component check
-- for overlap with any of the preceding elements on the component
-- list containing the component, and also, if the component is in
-- a variant, check against components outside the case structure.
-- This latter test is repeated recursively up the variant tree.
Main_Component_Loop : while Present (C1_Ent) loop
if Ekind (C1_Ent) /= E_Component
and then Ekind (C1_Ent) /= E_Discriminant
then
goto Continue_Main_Component_Loop;
end if;
-- Skip overlap check if entity has no declaration node. This
-- happens with discriminants in constrained derived types.
-- Probably we are missing some checks as a result, but that
-- does not seem terribly serious ???
if No (Declaration_Node (C1_Ent)) then
goto Continue_Main_Component_Loop;
end if;
Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
-- Loop through component lists that need checking. Check the
-- current component list and all lists in variants above us.
Component_List_Loop : loop
-- If derived type definition, go to full declaration
-- If at outer level, check discriminants if there are any
if Nkind (Clist) = N_Derived_Type_Definition then
Clist := Parent (Clist);
end if;
-- Outer level of record definition, check discriminants
if Nkind (Clist) = N_Full_Type_Declaration
or else Nkind (Clist) = N_Private_Type_Declaration
then
if Has_Discriminants (Defining_Identifier (Clist)) then
C2_Ent :=
First_Discriminant (Defining_Identifier (Clist));
while Present (C2_Ent) loop
exit when C1_Ent = C2_Ent;
Check_Component_Overlap (C1_Ent, C2_Ent);
Next_Discriminant (C2_Ent);
end loop;
end if;
-- Record extension case
elsif Nkind (Clist) = N_Derived_Type_Definition then
Clist := Empty;
-- Otherwise check one component list
else
Citem := First (Component_Items (Clist));
while Present (Citem) loop
if Nkind (Citem) = N_Component_Declaration then
C2_Ent := Defining_Identifier (Citem);
exit when C1_Ent = C2_Ent;
Check_Component_Overlap (C1_Ent, C2_Ent);
end if;
Next (Citem);
end loop;
end if;
-- Check for variants above us (the parent of the Clist can
-- be a variant, in which case its parent is a variant part,
-- and the parent of the variant part is a component list
-- whose components must all be checked against the current
-- component for overlap.
if Nkind (Parent (Clist)) = N_Variant then
Clist := Parent (Parent (Parent (Clist)));
-- Check for possible discriminant part in record, this is
-- treated essentially as another level in the recursion.
-- For this case we have the parent of the component list
-- is the record definition, and its parent is the full
-- type declaration which contains the discriminant
-- specifications.
elsif Nkind (Parent (Clist)) = N_Record_Definition then
Clist := Parent (Parent ((Clist)));
-- If neither of these two cases, we are at the top of
-- the tree
else
exit Component_List_Loop;
end if;
end loop Component_List_Loop;
<<Continue_Main_Component_Loop>>
Next_Entity (C1_Ent);
end loop Main_Component_Loop;
end Overlap_Check2;
end if;
-- For records that have component clauses for all components, and
-- whose size is less than or equal to 32, we need to know the size
-- in the front end to activate possible packed array processing
-- where the component type is a record.
-- At this stage Hbit + 1 represents the first unused bit from all
-- the component clauses processed, so if the component clauses are
-- complete, then this is the length of the record.
-- For records longer than System.Storage_Unit, and for those where
-- not all components have component clauses, the back end determines
-- the length (it may for example be appopriate to round up the size
-- to some convenient boundary, based on alignment considerations etc).
if Unknown_RM_Size (Rectype)
and then Hbit + 1 <= 32
then
-- Nothing to do if at least one component with no component clause
Comp := First_Entity (Rectype);
while Present (Comp) loop
if Ekind (Comp) = E_Component
or else Ekind (Comp) = E_Discriminant
then
if No (Component_Clause (Comp)) then
return;
end if;
end if;
Next_Entity (Comp);
end loop;
-- If we fall out of loop, all components have component clauses
-- and so we can set the size to the maximum value.
Set_RM_Size (Rectype, Hbit + 1);
end if;
end Analyze_Record_Representation_Clause;
-----------------------------
-- Check_Component_Overlap --
-----------------------------
procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
begin
if Present (Component_Clause (C1_Ent))
and then Present (Component_Clause (C2_Ent))
then
-- Exclude odd case where we have two tag fields in the same
-- record, both at location zero. This seems a bit strange,
-- but it seems to happen in some circumstances ???
if Chars (C1_Ent) = Name_uTag
and then Chars (C2_Ent) = Name_uTag
then
return;
end if;
-- Here we check if the two fields overlap
declare
S1 : constant Uint := Component_Bit_Offset (C1_Ent);
S2 : constant Uint := Component_Bit_Offset (C2_Ent);
E1 : constant Uint := S1 + Esize (C1_Ent);
E2 : constant Uint := S2 + Esize (C2_Ent);
begin
if E2 <= S1 or else E1 <= S2 then
null;
else
Error_Msg_Node_2 :=
Component_Name (Component_Clause (C2_Ent));
Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
Error_Msg_Node_1 :=
Component_Name (Component_Clause (C1_Ent));
Error_Msg_N
("component& overlaps & #",
Component_Name (Component_Clause (C1_Ent)));
end if;
end;
end if;
end Check_Component_Overlap;
-----------------------------------
-- Check_Constant_Address_Clause --
-----------------------------------
procedure Check_Constant_Address_Clause
(Expr : Node_Id;
U_Ent : Entity_Id)
is
procedure Check_At_Constant_Address (Nod : Node_Id);
-- Checks that the given node N represents a name whose 'Address
-- is constant (in the same sense as OK_Constant_Address_Clause,
-- i.e. the address value is the same at the point of declaration
-- of U_Ent and at the time of elaboration of the address clause.
procedure Check_Expr_Constants (Nod : Node_Id);
-- Checks that Nod meets the requirements for a constant address
-- clause in the sense of the enclosing procedure.
procedure Check_List_Constants (Lst : List_Id);
-- Check that all elements of list Lst meet the requirements for a
-- constant address clause in the sense of the enclosing procedure.
-------------------------------
-- Check_At_Constant_Address --
-------------------------------
procedure Check_At_Constant_Address (Nod : Node_Id) is
begin
if Is_Entity_Name (Nod) then
if Present (Address_Clause (Entity ((Nod)))) then
Error_Msg_NE
("invalid address clause for initialized object &!",
Nod, U_Ent);
Error_Msg_NE
("address for& cannot" &
" depend on another address clause! ('R'M 13.1(22))!",
Nod, U_Ent);
elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
and then Sloc (U_Ent) < Sloc (Entity (Nod))
then
Error_Msg_NE
("invalid address clause for initialized object &!",
Nod, U_Ent);
Error_Msg_Name_1 := Chars (Entity (Nod));
Error_Msg_Name_2 := Chars (U_Ent);
Error_Msg_N
("\% must be defined before % ('R'M 13.1(22))!",
Nod);
end if;
elsif Nkind (Nod) = N_Selected_Component then
declare
T : constant Entity_Id := Etype (Prefix (Nod));
begin
if (Is_Record_Type (T)
and then Has_Discriminants (T))
or else
(Is_Access_Type (T)
and then Is_Record_Type (Designated_Type (T))
and then Has_Discriminants (Designated_Type (T)))
then
Error_Msg_NE
("invalid address clause for initialized object &!",
Nod, U_Ent);
Error_Msg_N
("\address cannot depend on component" &
" of discriminated record ('R'M 13.1(22))!",
Nod);
else
Check_At_Constant_Address (Prefix (Nod));
end if;
end;
elsif Nkind (Nod) = N_Indexed_Component then
Check_At_Constant_Address (Prefix (Nod));
Check_List_Constants (Expressions (Nod));
else
Check_Expr_Constants (Nod);
end if;
end Check_At_Constant_Address;
--------------------------
-- Check_Expr_Constants --
--------------------------
procedure Check_Expr_Constants (Nod : Node_Id) is
begin
if Nkind (Nod) in N_Has_Etype
and then Etype (Nod) = Any_Type
then
return;
end if;
case Nkind (Nod) is
when N_Empty | N_Error =>
return;
when N_Identifier | N_Expanded_Name =>
declare
Ent : constant Entity_Id := Entity (Nod);
Loc_Ent : constant Source_Ptr := Sloc (Ent);
Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
begin
if Ekind (Ent) = E_Named_Integer
or else
Ekind (Ent) = E_Named_Real
or else
Is_Type (Ent)
then
return;
elsif
Ekind (Ent) = E_Constant
or else
Ekind (Ent) = E_In_Parameter
then
-- This is the case where we must have Ent defined
-- before U_Ent. Clearly if they are in different
-- units this requirement is met since the unit
-- containing Ent is already processed.
if not In_Same_Source_Unit (Ent, U_Ent) then
return;
-- Otherwise location of Ent must be before the
-- location of U_Ent, that's what prior defined means.
elsif Loc_Ent < Loc_U_Ent then
return;
else
Error_Msg_NE
("invalid address clause for initialized object &!",
Nod, U_Ent);
Error_Msg_Name_1 := Chars (Ent);
Error_Msg_Name_2 := Chars (U_Ent);
Error_Msg_N
("\% must be defined before % ('R'M 13.1(22))!",
Nod);
end if;
elsif Nkind (Original_Node (Nod)) = N_Function_Call then
Check_Expr_Constants (Original_Node (Nod));
else
Error_Msg_NE
("invalid address clause for initialized object &!",
Nod, U_Ent);
Error_Msg_Name_1 := Chars (Ent);
Error_Msg_N
("\reference to variable% not allowed ('R'M 13.1(22))!",
Nod);
end if;
end;
when N_Integer_Literal |
N_Real_Literal |
N_String_Literal |
N_Character_Literal =>
return;
when N_Range =>
Check_Expr_Constants (Low_Bound (Nod));
Check_Expr_Constants (High_Bound (Nod));
when N_Explicit_Dereference =>
Check_Expr_Constants (Prefix (Nod));
when N_Indexed_Component =>
Check_Expr_Constants (Prefix (Nod));
Check_List_Constants (Expressions (Nod));
when N_Slice =>
Check_Expr_Constants (Prefix (Nod));
Check_Expr_Constants (Discrete_Range (Nod));
when N_Selected_Component =>
Check_Expr_Constants (Prefix (Nod));
when N_Attribute_Reference =>
if (Attribute_Name (Nod) = Name_Address
or else
Attribute_Name (Nod) = Name_Access
or else
Attribute_Name (Nod) = Name_Unchecked_Access
or else
Attribute_Name (Nod) = Name_Unrestricted_Access)
then
Check_At_Constant_Address (Prefix (Nod));
else
Check_Expr_Constants (Prefix (Nod));
Check_List_Constants (Expressions (Nod));
end if;
when N_Aggregate =>
Check_List_Constants (Component_Associations (Nod));
Check_List_Constants (Expressions (Nod));
when N_Component_Association =>
Check_Expr_Constants (Expression (Nod));
when N_Extension_Aggregate =>
Check_Expr_Constants (Ancestor_Part (Nod));
Check_List_Constants (Component_Associations (Nod));
Check_List_Constants (Expressions (Nod));
when N_Null =>
return;
when N_Binary_Op | N_And_Then | N_Or_Else | N_In | N_Not_In =>
Check_Expr_Constants (Left_Opnd (Nod));
Check_Expr_Constants (Right_Opnd (Nod));
when N_Unary_Op =>
Check_Expr_Constants (Right_Opnd (Nod));
when N_Type_Conversion |
N_Qualified_Expression |
N_Allocator =>
Check_Expr_Constants (Expression (Nod));
when N_Unchecked_Type_Conversion =>
Check_Expr_Constants (Expression (Nod));
-- If this is a rewritten unchecked conversion, subtypes
-- in this node are those created within the instance.
-- To avoid order of elaboration issues, replace them
-- with their base types. Note that address clauses can
-- cause order of elaboration problems because they are
-- elaborated by the back-end at the point of definition,
-- and may mention entities declared in between (as long
-- as everything is static). It is user-friendly to allow
-- unchecked conversions in this context.
if Nkind (Original_Node (Nod)) = N_Function_Call then
Set_Etype (Expression (Nod),
Base_Type (Etype (Expression (Nod))));
Set_Etype (Nod, Base_Type (Etype (Nod)));
end if;
when N_Function_Call =>
if not Is_Pure (Entity (Name (Nod))) then
Error_Msg_NE
("invalid address clause for initialized object &!",
Nod, U_Ent);
Error_Msg_NE
("\function & is not pure ('R'M 13.1(22))!",
Nod, Entity (Name (Nod)));
else
Check_List_Constants (Parameter_Associations (Nod));
end if;
when N_Parameter_Association =>
Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
when others =>
Error_Msg_NE
("invalid address clause for initialized object &!",
Nod, U_Ent);
Error_Msg_NE
("\must be constant defined before& ('R'M 13.1(22))!",
Nod, U_Ent);
end case;
end Check_Expr_Constants;
--------------------------
-- Check_List_Constants --
--------------------------
procedure Check_List_Constants (Lst : List_Id) is
Nod1 : Node_Id;
begin
if Present (Lst) then
Nod1 := First (Lst);
while Present (Nod1) loop
Check_Expr_Constants (Nod1);
Next (Nod1);
end loop;
end if;
end Check_List_Constants;
-- Start of processing for Check_Constant_Address_Clause
begin
Check_Expr_Constants (Expr);
end Check_Constant_Address_Clause;
----------------
-- Check_Size --
----------------
procedure Check_Size
(N : Node_Id;
T : Entity_Id;
Siz : Uint;
Biased : out Boolean)
is
UT : constant Entity_Id := Underlying_Type (T);
M : Uint;
begin
Biased := False;
-- Immediate return if size is same as standard size or if composite
-- item, or generic type, or type with previous errors.
if No (UT)
or else UT = Any_Type
or else Is_Generic_Type (UT)
or else Is_Generic_Type (Root_Type (UT))
or else Is_Composite_Type (UT)
or else (Known_Esize (UT) and then Siz = Esize (UT))
then
return;
-- For fixed-point types, don't check minimum if type is not frozen,
-- since type is not known till then
-- at freeze time.
elsif Is_Fixed_Point_Type (UT)
and then not Is_Frozen (UT)
then
null;
-- Cases for which a minimum check is required
else
M := UI_From_Int (Minimum_Size (UT));
if Siz < M then
-- Size is less than minimum size, but one possibility remains
-- that we can manage with the new size if we bias the type
M := UI_From_Int (Minimum_Size (UT, Biased => True));
if Siz < M then
Error_Msg_Uint_1 := M;
Error_Msg_NE
("size for& too small, minimum allowed is ^", N, T);
else
Biased := True;
end if;
end if;
end if;
end Check_Size;
-------------------------
-- Get_Alignment_Value --
-------------------------
function Get_Alignment_Value (Expr : Node_Id) return Uint is
Align : constant Uint := Static_Integer (Expr);
begin
if Align = No_Uint then
return No_Uint;
elsif Align <= 0 then
Error_Msg_N ("alignment value must be positive", Expr);
return No_Uint;
else
for J in Int range 0 .. 64 loop
declare
M : constant Uint := Uint_2 ** J;
begin
exit when M = Align;
if M > Align then
Error_Msg_N
("alignment value must be power of 2", Expr);
return No_Uint;
end if;
end;
end loop;
return Align;
end if;
end Get_Alignment_Value;
-------------------------------------
-- Get_Attribute_Definition_Clause --
-------------------------------------
function Get_Attribute_Definition_Clause
(E : Entity_Id;
Id : Attribute_Id)
return Node_Id
is
N : Node_Id;
begin
N := First_Rep_Item (E);
while Present (N) loop
if Nkind (N) = N_Attribute_Definition_Clause
and then Get_Attribute_Id (Chars (N)) = Id
then
return N;
else
Next_Rep_Item (N);
end if;
end loop;
return Empty;
end Get_Attribute_Definition_Clause;
--------------------
-- Get_Rep_Pragma --
--------------------
function Get_Rep_Pragma (E : Entity_Id; Nam : Name_Id) return Node_Id is
N : Node_Id;
Typ : Entity_Id;
begin
N := First_Rep_Item (E);
while Present (N) loop
if Nkind (N) = N_Pragma and then Chars (N) = Nam then
if Nam = Name_Stream_Convert then
-- For tagged types this pragma is not inherited, so we
-- must verify that it is defined for the given type and
-- not an ancestor.
Typ := Entity (Expression
(First (Pragma_Argument_Associations (N))));
if not Is_Tagged_Type (E)
or else E = Typ
or else (Is_Private_Type (Typ)
and then E = Full_View (Typ))
then
return N;
else
Next_Rep_Item (N);
end if;
else
return N;
end if;
else
Next_Rep_Item (N);
end if;
end loop;
return Empty;
end Get_Rep_Pragma;
----------------
-- Initialize --
----------------
procedure Initialize is
begin
Unchecked_Conversions.Init;
end Initialize;
-------------------------
-- Is_Operational_Item --
-------------------------
function Is_Operational_Item (N : Node_Id) return Boolean is
begin
if Nkind (N) /= N_Attribute_Definition_Clause then
return False;
else
declare
Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
begin
return Id = Attribute_Input
or else Id = Attribute_Output
or else Id = Attribute_Read
or else Id = Attribute_Write;
end;
end if;
end Is_Operational_Item;
------------------
-- Minimum_Size --
------------------
function Minimum_Size
(T : Entity_Id;
Biased : Boolean := False)
return Nat
is
Lo : Uint := No_Uint;
Hi : Uint := No_Uint;
LoR : Ureal := No_Ureal;
HiR : Ureal := No_Ureal;
LoSet : Boolean := False;
HiSet : Boolean := False;
B : Uint;
S : Nat;
Ancest : Entity_Id;
begin
-- If bad type, return 0
if T = Any_Type then
return 0;
-- For generic types, just return zero. There cannot be any legitimate
-- need to know such a size, but this routine may be called with a
-- generic type as part of normal processing.
elsif Is_Generic_Type (Root_Type (T)) then
return 0;
-- Access types
elsif Is_Access_Type (T) then
return System_Address_Size;
-- Floating-point types
elsif Is_Floating_Point_Type (T) then
return UI_To_Int (Esize (Root_Type (T)));
-- Discrete types
elsif Is_Discrete_Type (T) then
-- The following loop is looking for the nearest compile time
-- known bounds following the ancestor subtype chain. The idea
-- is to find the most restrictive known bounds information.
Ancest := T;
loop
if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
return 0;
end if;
if not LoSet then
if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
LoSet := True;
exit when HiSet;
end if;
end if;
if not HiSet then
if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
HiSet := True;
exit when LoSet;
end if;
end if;
Ancest := Ancestor_Subtype (Ancest);
if No (Ancest) then
Ancest := Base_Type (T);
if Is_Generic_Type (Ancest) then
return 0;
end if;
end if;
end loop;
-- Fixed-point types. We can't simply use Expr_Value to get the
-- Corresponding_Integer_Value values of the bounds, since these
-- do not get set till the type is frozen, and this routine can
-- be called before the type is frozen. Similarly the test for
-- bounds being static needs to include the case where we have
-- unanalyzed real literals for the same reason.
elsif Is_Fixed_Point_Type (T) then
-- The following loop is looking for the nearest compile time
-- known bounds following the ancestor subtype chain. The idea
-- is to find the most restrictive known bounds information.
Ancest := T;
loop
if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
return 0;
end if;
if not LoSet then
if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
then
LoR := Expr_Value_R (Type_Low_Bound (Ancest));
LoSet := True;
exit when HiSet;
end if;
end if;
if not HiSet then
if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
then
HiR := Expr_Value_R (Type_High_Bound (Ancest));
HiSet := True;
exit when LoSet;
end if;
end if;
Ancest := Ancestor_Subtype (Ancest);
if No (Ancest) then
Ancest := Base_Type (T);
if Is_Generic_Type (Ancest) then
return 0;
end if;
end if;
end loop;
Lo := UR_To_Uint (LoR / Small_Value (T));
Hi := UR_To_Uint (HiR / Small_Value (T));
-- No other types allowed
else
raise Program_Error;
end if;
-- Fall through with Hi and Lo set. Deal with biased case.
if (Biased and then not Is_Fixed_Point_Type (T))
or else Has_Biased_Representation (T)
then
Hi := Hi - Lo;
Lo := Uint_0;
end if;
-- Signed case. Note that we consider types like range 1 .. -1 to be
-- signed for the purpose of computing the size, since the bounds
-- have to be accomodated in the base type.
if Lo < 0 or else Hi < 0 then
S := 1;
B := Uint_1;
-- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
-- Note that we accommodate the case where the bounds cross. This
-- can happen either because of the way the bounds are declared
-- or because of the algorithm in Freeze_Fixed_Point_Type.
while Lo < -B
or else Hi < -B
or else Lo >= B
or else Hi >= B
loop
B := Uint_2 ** S;
S := S + 1;
end loop;
-- Unsigned case
else
-- If both bounds are positive, make sure that both are represen-
-- table in the case where the bounds are crossed. This can happen
-- either because of the way the bounds are declared, or because of
-- the algorithm in Freeze_Fixed_Point_Type.
if Lo > Hi then
Hi := Lo;
end if;
-- S = size, (can accommodate 0 .. (2**size - 1))
S := 0;
while Hi >= Uint_2 ** S loop
S := S + 1;
end loop;
end if;
return S;
end Minimum_Size;
-------------------------
-- New_Stream_Function --
-------------------------
procedure New_Stream_Function
(N : Node_Id;
Ent : Entity_Id;
Subp : Entity_Id;
Nam : Name_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Subp_Id : Entity_Id := Make_Defining_Identifier (Loc, Nam);
Subp_Decl : Node_Id;
F : Entity_Id;
Etyp : Entity_Id;
begin
F := First_Formal (Subp);
Etyp := Etype (Subp);
Subp_Decl :=
Make_Subprogram_Renaming_Declaration (Loc,
Specification =>
Make_Function_Specification (Loc,
Defining_Unit_Name => Subp_Id,
Parameter_Specifications =>
New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_S),
Parameter_Type =>
Make_Access_Definition (Loc,
Subtype_Mark =>
New_Reference_To (
Designated_Type (Etype (F)), Loc)))),
Subtype_Mark =>
New_Reference_To (Etyp, Loc)),
Name => New_Reference_To (Subp, Loc));
if Is_Tagged_Type (Ent) and then not Is_Limited_Type (Ent) then
Set_TSS (Base_Type (Ent), Subp_Id);
else
Insert_Action (N, Subp_Decl);
Copy_TSS (Subp_Id, Base_Type (Ent));
end if;
end New_Stream_Function;
--------------------------
-- New_Stream_Procedure --
--------------------------
procedure New_Stream_Procedure
(N : Node_Id;
Ent : Entity_Id;
Subp : Entity_Id;
Nam : Name_Id;
Out_P : Boolean := False)
is
Loc : constant Source_Ptr := Sloc (N);
Subp_Id : Entity_Id := Make_Defining_Identifier (Loc, Nam);
Subp_Decl : Node_Id;
F : Entity_Id;
Etyp : Entity_Id;
begin
F := First_Formal (Subp);
Etyp := Etype (Next_Formal (F));
Subp_Decl :=
Make_Subprogram_Renaming_Declaration (Loc,
Specification =>
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Subp_Id,
Parameter_Specifications =>
New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_S),
Parameter_Type =>
Make_Access_Definition (Loc,
Subtype_Mark =>
New_Reference_To (
Designated_Type (Etype (F)), Loc))),
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_V),
Out_Present => Out_P,
Parameter_Type =>
New_Reference_To (Etyp, Loc)))),
Name => New_Reference_To (Subp, Loc));
if Is_Tagged_Type (Ent) and then not Is_Limited_Type (Ent) then
Set_TSS (Base_Type (Ent), Subp_Id);
else
Insert_Action (N, Subp_Decl);
Copy_TSS (Subp_Id, Base_Type (Ent));
end if;
end New_Stream_Procedure;
---------------------
-- Record_Rep_Item --
---------------------
procedure Record_Rep_Item (T : Entity_Id; N : Node_Id) is
begin
Set_Next_Rep_Item (N, First_Rep_Item (T));
Set_First_Rep_Item (T, N);
end Record_Rep_Item;
------------------------
-- Rep_Item_Too_Early --
------------------------
function Rep_Item_Too_Early
(T : Entity_Id;
N : Node_Id)
return Boolean
is
begin
-- Cannot apply rep items to generic types
if Is_Type (T)
and then Is_Generic_Type (Root_Type (T))
then
Error_Msg_N
("representation item not allowed for generic type", N);
return True;
end if;
-- Otherwise check for incompleted type
if Is_Incomplete_Or_Private_Type (T)
and then No (Underlying_Type (T))
then
Error_Msg_N
("representation item must be after full type declaration", N);
return True;
-- If the type has incompleted components, a representation clause is
-- illegal but stream attributes and Convention pragmas are correct.
elsif Has_Private_Component (T) then
if (Nkind (N) = N_Pragma or else Is_Operational_Item (N)) then
return False;
else
Error_Msg_N
("representation item must appear after type is fully defined",
N);
return True;
end if;
else
return False;
end if;
end Rep_Item_Too_Early;
-----------------------
-- Rep_Item_Too_Late --
-----------------------
function Rep_Item_Too_Late
(T : Entity_Id;
N : Node_Id;
FOnly : Boolean := False)
return Boolean
is
S : Entity_Id;
Parent_Type : Entity_Id;
procedure Too_Late;
-- Output the too late message
procedure Too_Late is
begin
Error_Msg_N ("representation item appears too late!", N);
end Too_Late;
-- Start of processing for Rep_Item_Too_Late
begin
-- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
-- types, which may be frozen if they appear in a representation clause
-- for a local type.
if Is_Frozen (T)
and then not From_With_Type (T)
then
Too_Late;
S := First_Subtype (T);
if Present (Freeze_Node (S)) then
Error_Msg_NE
("?no more representation items for }!", Freeze_Node (S), S);
end if;
return True;
-- Check for case of non-tagged derived type whose parent either has
-- primitive operations, or is a by reference type (RM 13.1(10)).
elsif Is_Type (T)
and then not FOnly
and then Is_Derived_Type (T)
and then not Is_Tagged_Type (T)
then
Parent_Type := Etype (Base_Type (T));
if Has_Primitive_Operations (Parent_Type) then
Too_Late;
Error_Msg_NE
("primitive operations already defined for&!", N, Parent_Type);
return True;
elsif Is_By_Reference_Type (Parent_Type) then
Too_Late;
Error_Msg_NE
("parent type & is a by reference type!", N, Parent_Type);
return True;
end if;
end if;
-- No error, link item into head of chain of rep items for the entity
Record_Rep_Item (T, N);
return False;
end Rep_Item_Too_Late;
-------------------------
-- Same_Representation --
-------------------------
function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
T1 : constant Entity_Id := Underlying_Type (Typ1);
T2 : constant Entity_Id := Underlying_Type (Typ2);
begin
-- A quick check, if base types are the same, then we definitely have
-- the same representation, because the subtype specific representation
-- attributes (Size and Alignment) do not affect representation from
-- the point of view of this test.
if Base_Type (T1) = Base_Type (T2) then
return True;
elsif Is_Private_Type (Base_Type (T2))
and then Base_Type (T1) = Full_View (Base_Type (T2))
then
return True;
end if;
-- Tagged types never have differing representations
if Is_Tagged_Type (T1) then
return True;
end if;
-- Representations are definitely different if conventions differ
if Convention (T1) /= Convention (T2) then
return False;
end if;
-- Representations are different if component alignments differ
if (Is_Record_Type (T1) or else Is_Array_Type (T1))
and then
(Is_Record_Type (T2) or else Is_Array_Type (T2))
and then Component_Alignment (T1) /= Component_Alignment (T2)
then
return False;
end if;
-- For arrays, the only real issue is component size. If we know the
-- component size for both arrays, and it is the same, then that's
-- good enough to know we don't have a change of representation.
if Is_Array_Type (T1) then
if Known_Component_Size (T1)
and then Known_Component_Size (T2)
and then Component_Size (T1) = Component_Size (T2)
then
return True;
end if;
end if;
-- Types definitely have same representation if neither has non-standard
-- representation since default representations are always consistent.
-- If only one has non-standard representation, and the other does not,
-- then we consider that they do not have the same representation. They
-- might, but there is no way of telling early enough.
if Has_Non_Standard_Rep (T1) then
if not Has_Non_Standard_Rep (T2) then
return False;
end if;
else
return not Has_Non_Standard_Rep (T2);
end if;
-- Here the two types both have non-standard representation, and we
-- need to determine if they have the same non-standard representation
-- For arrays, we simply need to test if the component sizes are the
-- same. Pragma Pack is reflected in modified component sizes, so this
-- check also deals with pragma Pack.
if Is_Array_Type (T1) then
return Component_Size (T1) = Component_Size (T2);
-- Tagged types always have the same representation, because it is not
-- possible to specify different representations for common fields.
elsif Is_Tagged_Type (T1) then
return True;
-- Case of record types
elsif Is_Record_Type (T1) then
-- Packed status must conform
if Is_Packed (T1) /= Is_Packed (T2) then
return False;
-- Otherwise we must check components. Typ2 maybe a constrained
-- subtype with fewer components, so we compare the components
-- of the base types.
else
Record_Case : declare
CD1, CD2 : Entity_Id;
function Same_Rep return Boolean;
-- CD1 and CD2 are either components or discriminants. This
-- function tests whether the two have the same representation
function Same_Rep return Boolean is
begin
if No (Component_Clause (CD1)) then
return No (Component_Clause (CD2));
else
return
Present (Component_Clause (CD2))
and then
Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
and then
Esize (CD1) = Esize (CD2);
end if;
end Same_Rep;
-- Start processing for Record_Case
begin
if Has_Discriminants (T1) then
CD1 := First_Discriminant (T1);
CD2 := First_Discriminant (T2);
while Present (CD1) loop
if not Same_Rep then
return False;
else
Next_Discriminant (CD1);
Next_Discriminant (CD2);
end if;
end loop;
end if;
CD1 := First_Component (Underlying_Type (Base_Type (T1)));
CD2 := First_Component (Underlying_Type (Base_Type (T2)));
while Present (CD1) loop
if not Same_Rep then
return False;
else
Next_Component (CD1);
Next_Component (CD2);
end if;
end loop;
return True;
end Record_Case;
end if;
-- For enumeration types, we must check each literal to see if the
-- representation is the same. Note that we do not permit enumeration
-- representation clauses for Character and Wide_Character, so these
-- cases were already dealt with.
elsif Is_Enumeration_Type (T1) then
Enumeration_Case : declare
L1, L2 : Entity_Id;
begin
L1 := First_Literal (T1);
L2 := First_Literal (T2);
while Present (L1) loop
if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
return False;
else
Next_Literal (L1);
Next_Literal (L2);
end if;
end loop;
return True;
end Enumeration_Case;
-- Any other types have the same representation for these purposes
else
return True;
end if;
end Same_Representation;
--------------------
-- Set_Enum_Esize --
--------------------
procedure Set_Enum_Esize (T : Entity_Id) is
Lo : Uint;
Hi : Uint;
Sz : Nat;
begin
Init_Alignment (T);
-- Find the minimum standard size (8,16,32,64) that fits
Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
if Lo < 0 then
if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
Sz := 8;
elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
Sz := 16;
elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
Sz := 32;
else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
Sz := 64;
end if;
else
if Hi < Uint_2**08 then
Sz := 8;
elsif Hi < Uint_2**16 then
Sz := 16;
elsif Hi < Uint_2**32 then
Sz := 32;
else pragma Assert (Hi < Uint_2**63);
Sz := 64;
end if;
end if;
-- That minimum is the proper size unless we have a foreign convention
-- and the size required is 32 or less, in which case we bump the size
-- up to 32. This is required for C and C++ and seems reasonable for
-- all other foreign conventions.
if Has_Foreign_Convention (T)
and then Esize (T) < Standard_Integer_Size
then
Init_Esize (T, Standard_Integer_Size);
else
Init_Esize (T, Sz);
end if;
end Set_Enum_Esize;
-----------------------------------
-- Validate_Unchecked_Conversion --
-----------------------------------
procedure Validate_Unchecked_Conversion
(N : Node_Id;
Act_Unit : Entity_Id)
is
Source : Entity_Id;
Target : Entity_Id;
Vnode : Node_Id;
begin
-- Obtain source and target types. Note that we call Ancestor_Subtype
-- here because the processing for generic instantiation always makes
-- subtypes, and we want the original frozen actual types.
-- If we are dealing with private types, then do the check on their
-- fully declared counterparts if the full declarations have been
-- encountered (they don't have to be visible, but they must exist!)
Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
if Is_Private_Type (Source)
and then Present (Underlying_Type (Source))
then
Source := Underlying_Type (Source);
end if;
Target := Ancestor_Subtype (Etype (Act_Unit));
-- If either type is generic, the instantiation happens within a
-- generic unit, and there is nothing to check. The proper check
-- will happen when the enclosing generic is instantiated.
if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
return;
end if;
if Is_Private_Type (Target)
and then Present (Underlying_Type (Target))
then
Target := Underlying_Type (Target);
end if;
-- Source may be unconstrained array, but not target
if Is_Array_Type (Target)
and then not Is_Constrained (Target)
then
Error_Msg_N
("unchecked conversion to unconstrained array not allowed", N);
return;
end if;
-- Make entry in unchecked conversion table for later processing
-- by Validate_Unchecked_Conversions, which will check sizes and
-- alignments (using values set by the back-end where possible).
Unchecked_Conversions.Append
(New_Val => UC_Entry'
(Enode => N,
Source => Source,
Target => Target));
-- Generate N_Validate_Unchecked_Conversion node for back end if
-- the back end needs to perform special validation checks. At the
-- current time, only the JVM version requires such checks.
if Java_VM then
Vnode :=
Make_Validate_Unchecked_Conversion (Sloc (N));
Set_Source_Type (Vnode, Source);
Set_Target_Type (Vnode, Target);
Insert_After (N, Vnode);
end if;
end Validate_Unchecked_Conversion;
------------------------------------
-- Validate_Unchecked_Conversions --
------------------------------------
procedure Validate_Unchecked_Conversions is
begin
for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
declare
T : UC_Entry renames Unchecked_Conversions.Table (N);
Enode : constant Node_Id := T.Enode;
Source : constant Entity_Id := T.Source;
Target : constant Entity_Id := T.Target;
Source_Siz : Uint;
Target_Siz : Uint;
begin
-- This validation check, which warns if we have unequal sizes
-- for unchecked conversion, and thus potentially implementation
-- dependent semantics, is one of the few occasions on which we
-- use the official RM size instead of Esize. See description
-- in Einfo "Handling of Type'Size Values" for details.
if Errors_Detected = 0
and then Known_Static_RM_Size (Source)
and then Known_Static_RM_Size (Target)
then
Source_Siz := RM_Size (Source);
Target_Siz := RM_Size (Target);
if Source_Siz /= Target_Siz then
Warn_On_Instance := True;
Error_Msg_N
("types for unchecked conversion have different sizes?",
Enode);
if All_Errors_Mode then
Error_Msg_Name_1 := Chars (Source);
Error_Msg_Uint_1 := Source_Siz;
Error_Msg_Name_2 := Chars (Target);
Error_Msg_Uint_2 := Target_Siz;
Error_Msg_N
("\size of % is ^, size of % is ^?", Enode);
Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
if Is_Discrete_Type (Source)
and then Is_Discrete_Type (Target)
then
if Source_Siz > Target_Siz then
Error_Msg_N
("\^ high order bits of source will be ignored?",
Enode);
elsif Is_Modular_Integer_Type (Source) then
Error_Msg_N
("\source will be extended with ^ high order " &
"zero bits?", Enode);
else
Error_Msg_N
("\source will be extended with ^ high order " &
"sign bits?",
Enode);
end if;
elsif Source_Siz < Target_Siz then
if Is_Discrete_Type (Target) then
if Bytes_Big_Endian then
Error_Msg_N
("\target value will include ^ undefined " &
"low order bits?",
Enode);
else
Error_Msg_N
("\target value will include ^ undefined " &
"high order bits?",
Enode);
end if;
else
Error_Msg_N
("\^ trailing bits of target value will be " &
"undefined?", Enode);
end if;
else pragma Assert (Source_Siz > Target_Siz);
Error_Msg_N
("\^ trailing bits of source will be ignored?",
Enode);
end if;
end if;
Warn_On_Instance := False;
end if;
end if;
-- If both types are access types, we need to check the alignment.
-- If the alignment of both is specified, we can do it here.
if Errors_Detected = 0
and then Ekind (Source) in Access_Kind
and then Ekind (Target) in Access_Kind
and then Target_Strict_Alignment
and then Present (Designated_Type (Source))
and then Present (Designated_Type (Target))
then
declare
D_Source : constant Entity_Id := Designated_Type (Source);
D_Target : constant Entity_Id := Designated_Type (Target);
begin
if Known_Alignment (D_Source)
and then Known_Alignment (D_Target)
then
declare
Source_Align : constant Uint := Alignment (D_Source);
Target_Align : constant Uint := Alignment (D_Target);
begin
if Source_Align < Target_Align
and then not Is_Tagged_Type (D_Source)
then
Warn_On_Instance := True;
Error_Msg_Uint_1 := Target_Align;
Error_Msg_Uint_2 := Source_Align;
Error_Msg_Node_2 := D_Source;
Error_Msg_NE
("alignment of & (^) is stricter than " &
"alignment of & (^)?", Enode, D_Target);
if All_Errors_Mode then
Error_Msg_N
("\resulting access value may have invalid " &
"alignment?", Enode);
end if;
Warn_On_Instance := False;
end if;
end;
end if;
end;
end if;
end;
end loop;
end Validate_Unchecked_Conversions;
------------------
-- Warn_Overlay --
------------------
procedure Warn_Overlay
(Expr : Node_Id;
Typ : Entity_Id;
Nam : Node_Id)
is
Old : Entity_Id := Empty;
Decl : Node_Id;
begin
if not Address_Clause_Overlay_Warnings then
return;
end if;
if Present (Expr)
and then (Has_Non_Null_Base_Init_Proc (Typ)
or else Is_Access_Type (Typ))
and then not Is_Imported (Entity (Nam))
then
if Nkind (Expr) = N_Attribute_Reference
and then Is_Entity_Name (Prefix (Expr))
then
Old := Entity (Prefix (Expr));
elsif Is_Entity_Name (Expr)
and then Ekind (Entity (Expr)) = E_Constant
then
Decl := Declaration_Node (Entity (Expr));
if Nkind (Decl) = N_Object_Declaration
and then Present (Expression (Decl))
and then Nkind (Expression (Decl)) = N_Attribute_Reference
and then Is_Entity_Name (Prefix (Expression (Decl)))
then
Old := Entity (Prefix (Expression (Decl)));
elsif Nkind (Expr) = N_Function_Call then
return;
end if;
-- A function call (most likely to To_Address) is probably not
-- an overlay, so skip warning. Ditto if the function call was
-- inlined and transformed into an entity.
elsif Nkind (Original_Node (Expr)) = N_Function_Call then
return;
end if;
Decl := Next (Parent (Expr));
-- If a pragma Import follows, we assume that it is for the current
-- target of the address clause, and skip the warning.
if Present (Decl)
and then Nkind (Decl) = N_Pragma
and then Chars (Decl) = Name_Import
then
return;
end if;
if Present (Old) then
Error_Msg_Node_2 := Old;
Error_Msg_N
("default initialization of & may modify &?",
Nam);
else
Error_Msg_N
("default initialization of & may modify overlaid storage?",
Nam);
end if;
-- Add friendly warning if initialization comes from a packed array
-- component.
if Is_Record_Type (Typ) then
declare
Comp : Entity_Id;
begin
Comp := First_Component (Typ);
while Present (Comp) loop
if Nkind (Parent (Comp)) = N_Component_Declaration
and then Present (Expression (Parent (Comp)))
then
exit;
elsif Is_Array_Type (Etype (Comp))
and then Present (Packed_Array_Type (Etype (Comp)))
then
Error_Msg_NE
("packed array component& will be initialized to zero?",
Nam, Comp);
exit;
else
Next_Component (Comp);
end if;
end loop;
end;
end if;
Error_Msg_N
("use pragma Import for & to " &
"suppress initialization ('R'M B.1(24))?",
Nam);
end if;
end Warn_Overlay;
end Sem_Ch13;