+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNAT COMPILER COMPONENTS --
--- --
--- S E M _ C H 1 3 --
--- --
--- B o d y --
--- --
--- $Revision: 1.4.10.1 $
--- --
--- 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. --
--- Extensive contributions were provided by Ada Core Technologies Inc. --
--- --
-------------------------------------------------------------------------------
-
-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;
projects / msp430-gcc.git / blobdiff