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Diffstat (limited to 'gcc-4.2.1/gcc/ada/sem_ch13.adb')
| -rw-r--r-- | gcc-4.2.1/gcc/ada/sem_ch13.adb | 3908 |
1 files changed, 0 insertions, 3908 deletions
diff --git a/gcc-4.2.1/gcc/ada/sem_ch13.adb b/gcc-4.2.1/gcc/ada/sem_ch13.adb deleted file mode 100644 index 88c0fc005..000000000 --- a/gcc-4.2.1/gcc/ada/sem_ch13.adb +++ /dev/null @@ -1,3908 +0,0 @@ ------------------------------------------------------------------------------- --- -- --- GNAT COMPILER COMPONENTS -- --- -- --- S E M _ C H 1 3 -- --- -- --- B o d y -- --- -- --- Copyright (C) 1992-2006, 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, 51 Franklin Street, Fifth Floor, -- --- Boston, MA 02110-1301, 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 Lib; use Lib; -with Nlists; use Nlists; -with Nmake; use Nmake; -with Opt; use Opt; -with Restrict; use Restrict; -with Rident; use Rident; -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 Snames; use Snames; -with Stand; use Stand; -with Sinfo; use Sinfo; -with Table; -with Targparm; use Targparm; -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. - - function Address_Aliased_Entity (N : Node_Id) return Entity_Id; - -- If expression N is of the form E'Address, return E - - procedure Mark_Aliased_Address_As_Volatile (N : Node_Id); - -- This is used for processing of an address representation clause. If - -- the expression N is of the form of K'Address, then the entity that - -- is associated with K is marked as volatile. - - procedure New_Stream_Function - (N : Node_Id; - Ent : Entity_Id; - Subp : Entity_Id; - Nam : TSS_Name_Type); - -- 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. Nam indicates - -- the name of the TSS function to be generated. - -- - -- To avoid elaboration anomalies with freeze nodes, for untagged types - -- we generate both a subprogram declaration and a subprogram renaming - -- declaration, so that the attribute specification is handled as a - -- renaming_as_body. For tagged types, the specification is one of the - -- primitive specs. - - procedure New_Stream_Procedure - (N : Node_Id; - Ent : Entity_Id; - Subp : Entity_Id; - Nam : TSS_Name_Type; - 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. Nam indicates the name of - -- the TSS procedure to be generated. - - ---------------------------------------------- - -- 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"); - - ---------------------------- - -- Address_Aliased_Entity -- - ---------------------------- - - function Address_Aliased_Entity (N : Node_Id) return Entity_Id is - begin - if Nkind (N) = N_Attribute_Reference - and then Attribute_Name (N) = Name_Address - then - declare - Nam : Node_Id := Prefix (N); - begin - while False - or else Nkind (Nam) = N_Selected_Component - or else Nkind (Nam) = N_Indexed_Component - loop - Nam := Prefix (Nam); - end loop; - - if Is_Entity_Name (Nam) then - return Entity (Nam); - end if; - end; - end if; - - return Empty; - end Address_Aliased_Entity; - - -------------------------------------- - -- 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 - Check_Restriction (No_Obsolescent_Features, N); - - if Warn_On_Obsolescent_Feature then - Error_Msg_N - ("at clause is an obsolescent feature ('R'M 'J.7(2))?", N); - Error_Msg_N - ("\use address attribute definition clause instead?", N); - end if; - - 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. - - procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type); - -- Common processing for 'Read, 'Write, 'Input and 'Output attribute - -- definition clauses. - - procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is - Subp : Entity_Id := Empty; - I : Interp_Index; - It : Interp; - Pnam : Entity_Id; - - Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read); - - function Has_Good_Profile (Subp : Entity_Id) return Boolean; - -- Return true if the entity is a subprogram with an appropriate - -- profile for the attribute being defined. - - ---------------------- - -- Has_Good_Profile -- - ---------------------- - - function Has_Good_Profile (Subp : Entity_Id) return Boolean is - F : Entity_Id; - Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input); - Expected_Ekind : constant array (Boolean) of Entity_Kind := - (False => E_Procedure, True => E_Function); - Typ : Entity_Id; - - begin - if Ekind (Subp) /= Expected_Ekind (Is_Function) then - return False; - end if; - - F := First_Formal (Subp); - - if No (F) - or else Ekind (Etype (F)) /= E_Anonymous_Access_Type - or else Designated_Type (Etype (F)) /= - Class_Wide_Type (RTE (RE_Root_Stream_Type)) - then - return False; - end if; - - if not Is_Function then - Next_Formal (F); - - declare - Expected_Mode : constant array (Boolean) of Entity_Kind := - (False => E_In_Parameter, - True => E_Out_Parameter); - begin - if Parameter_Mode (F) /= Expected_Mode (Is_Read) then - return False; - end if; - end; - - Typ := Etype (F); - - else - Typ := Etype (Subp); - end if; - - return Base_Type (Typ) = Base_Type (Ent) - and then No (Next_Formal (F)); - - end Has_Good_Profile; - - -- Start of processing for Analyze_Stream_TSS_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), TSS_Nam); - - if Present (Pnam) and then Has_Good_Profile (Pnam) then - Error_Msg_Sloc := Sloc (Pnam); - Error_Msg_Name_1 := Attr; - Error_Msg_N ("% 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 - if Is_Abstract (Subp) then - Error_Msg_N ("stream subprogram must not be abstract", Expr); - return; - end if; - - Set_Entity (Expr, Subp); - Set_Etype (Expr, Etype (Subp)); - - if TSS_Nam = TSS_Stream_Input then - New_Stream_Function (N, U_Ent, Subp, TSS_Nam); - else - New_Stream_Procedure (N, U_Ent, Subp, TSS_Nam, - Out_P => Is_Read); - end if; - - else - Error_Msg_Name_1 := Attr; - Error_Msg_N ("incorrect expression for% attribute", Expr); - end if; - end Analyze_Stream_TSS_Definition; - - -- Start of processing for Analyze_Attribute_Definition_Clause - - 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 - - -- The attribute applies to the full view, set the entity of the - -- attribute definition accordingly. - - Ent := Underlying_Type (Ent); - U_Ent := Ent; - Set_Entity (Nam, 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 No (U_Ent) then - U_Ent := Ent; - - 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); - - if Is_Task_Type (Scope (U_Ent)) - and then Comes_From_Source (Scope (U_Ent)) - then - Error_Msg_N - ("?entry address declared for entry in task type", N); - Error_Msg_N - ("\?only one task can be declared of this type", N); - end if; - - Check_Restriction (No_Obsolescent_Features, N); - - if Warn_On_Obsolescent_Feature then - Error_Msg_N - ("attaching interrupt to task entry is an " & - "obsolescent feature ('R'M 'J.7.1)?", N); - Error_Msg_N - ("\use interrupt procedure instead?", N); - end if; - - -- Case of an address clause for a controlled object: - -- erroneous execution. - - elsif Is_Controlled (Etype (U_Ent)) then - Error_Msg_NE - ("?controlled object& must not be overlaid", Nam, U_Ent); - Error_Msg_N - ("\?Program_Error will be raised at run time", Nam); - Insert_Action (Declaration_Node (U_Ent), - Make_Raise_Program_Error (Loc, - Reason => PE_Overlaid_Controlled_Object)); - - -- Case of address clause for a (non-controlled) object - - elsif - Ekind (U_Ent) = E_Variable - or else - Ekind (U_Ent) = E_Constant - then - declare - Expr : constant Node_Id := Expression (N); - Aent : constant Entity_Id := Address_Aliased_Entity (Expr); - - 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); - - -- Overlaying controlled objects is erroneous - - elsif Present (Aent) - and then Is_Controlled (Etype (Aent)) - then - Error_Msg_N - ("?controlled object must not be overlaid", Expr); - Error_Msg_N - ("\?Program_Error will be raised at run time", Expr); - Insert_Action (Declaration_Node (U_Ent), - Make_Raise_Program_Error (Loc, - Reason => PE_Overlaid_Controlled_Object)); - - elsif Present (Aent) - and then Ekind (U_Ent) = E_Constant - and then Ekind (Aent) /= E_Constant - then - Error_Msg_N ("constant overlays a variable?", Expr); - - elsif Present (Renamed_Object (U_Ent)) then - Error_Msg_N - ("address clause not allowed" - & " for a renaming declaration ('R'M 13.1(6))", 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); - - -- Here we are checking for explicit overlap of one - -- variable by another, and if we find this, then we - -- mark the overlapped variable as also being aliased. - - -- First case is where we have an explicit - - -- for J'Address use K'Address; - - -- In this case, we mark K as volatile - - Mark_Aliased_Address_As_Volatile (Expr); - - -- Second case is where we have a constant whose - -- definition is of the form of an address as in: - - -- A : constant Address := K'Address; - -- ... - -- for B'Address use A; - - -- In this case we also mark K as volatile - - if Is_Entity_Name (Expr) then - declare - Ent : constant Entity_Id := Entity (Expr); - Decl : constant Node_Id := Declaration_Node (Ent); - - begin - if Ekind (Ent) = E_Constant - and then Nkind (Decl) = N_Object_Declaration - and then Present (Expression (Decl)) - then - Mark_Aliased_Address_As_Volatile - (Expression (Decl)); - end if; - end; - end if; - - -- Legality checks on the address clause for initialized - -- objects is deferred until the freeze point, because - -- a subsequent pragma might indicate that the object is - -- imported and thus not initialized. - - Set_Has_Delayed_Freeze (U_Ent); - - 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; - - -- Entity has delayed freeze, so we will generate - -- an alignment check at the freeze point. - - Set_Check_Address_Alignment - (N, not Range_Checks_Suppressed (U_Ent)); - - -- 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 : constant 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 - Flag_Non_Static_Expr - ("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 - Flag_Non_Static_Expr - ("static string required for tag name!", Nam); - end if; - - Set_Has_External_Tag_Rep_Clause (U_Ent); - end External_Tag; - - ----------- - -- Input -- - ----------- - - when Attribute_Input => - Analyze_Stream_TSS_Definition (TSS_Stream_Input); - Set_Has_Specified_Stream_Input (Ent); - - ------------------- - -- 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 => - Analyze_Stream_TSS_Definition (TSS_Stream_Output); - Set_Has_Specified_Stream_Output (Ent); - - ---------- - -- Read -- - ---------- - - when Attribute_Read => - Analyze_Stream_TSS_Definition (TSS_Stream_Read); - Set_Has_Specified_Stream_Read (Ent); - - ---------- - -- 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 a storage unit in any case (i.e., - -- normally this means it will be byte addressable). - - if Is_Scalar_Type (U_Ent) then - if Size <= System_Storage_Unit then - Init_Esize (U_Ent, System_Storage_Unit); - 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 - if Is_Elementary_Type (Etyp) then - if Size /= System_Storage_Unit - and then - Size /= System_Storage_Unit * 2 - and then - Size /= System_Storage_Unit * 4 - and then - Size /= System_Storage_Unit * 8 - then - Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit); - Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8; - Error_Msg_N - ("size for primitive object must be a power of 2" - & " in the range ^-^", N); - end if; - end if; - - 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 - Flag_Non_Static_Expr - ("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 - Check_Restriction (No_Obsolescent_Features, N); - - if Warn_On_Obsolescent_Feature then - Error_Msg_N - ("storage size clause for task is an " & - "obsolescent feature ('R'M 'J.9)?", N); - Error_Msg_N - ("\use Storage_Size pragma instead?", N); - end if; - - 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; - T : 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 Nkind (Expr) = N_Type_Conversion then - T := Etype (Expression (Expr)); - else - T := Etype (Expr); - end if; - - -- The Stack_Bounded_Pool is used internally for implementing - -- access types with a Storage_Size. Since it only work - -- properly when used on one specific type, we need to check - -- that it is not highjacked improperly: - -- type T is access Integer; - -- for T'Storage_Size use n; - -- type Q is access Float; - -- for Q'Storage_Size use T'Storage_Size; -- incorrect - - if Base_Type (T) = RTE (RE_Stack_Bounded_Pool) then - Error_Msg_N ("non-sharable internal Pool", Expr); - return; - end if; - - -- 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; - - Set_Associated_Storage_Pool (U_Ent, Pool); - - 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)); - Set_Associated_Storage_Pool (U_Ent, Pool); - - else - Error_Msg_N ("incorrect reference to a Storage Pool", Expr); - return; - end if; - end Storage_Pool; - - ----------------- - -- Stream_Size -- - ----------------- - - when Attribute_Stream_Size => Stream_Size : declare - Size : constant Uint := Static_Integer (Expr); - - begin - if Has_Stream_Size_Clause (U_Ent) then - Error_Msg_N ("Stream_Size already given for &", Nam); - - elsif Is_Elementary_Type (U_Ent) then - if Size /= System_Storage_Unit - and then - Size /= System_Storage_Unit * 2 - and then - Size /= System_Storage_Unit * 4 - and then - Size /= System_Storage_Unit * 8 - then - Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit); - Error_Msg_N - ("stream size for elementary type must be a" - & " power of 2 and at least ^", N); - - elsif RM_Size (U_Ent) > Size then - Error_Msg_Uint_1 := RM_Size (U_Ent); - Error_Msg_N - ("stream size for elementary type must be a" - & " power of 2 and at least ^", N); - end if; - - Set_Has_Stream_Size_Clause (U_Ent); - - else - Error_Msg_N ("Stream_Size cannot be given for &", Nam); - end if; - end Stream_Size; - - ---------------- - -- 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 -- - ----------- - - when Attribute_Write => - Analyze_Stream_TSS_Definition (TSS_Stream_Write); - Set_Has_Specified_Stream_Write (Ent); - - -- 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; - - -- Ignore rep clause on generic actual type. This will already have - -- been flagged on the template as an error, and this is the safest - -- way to ensure we don't get a junk cascaded message in the instance. - - if Is_Generic_Actual_Type (Enumtype) then - return; - - -- Type must be in current scope - - elsif Scope (Enumtype) /= Current_Scope then - Error_Msg_N ("type must be declared in this scope", Ident); - return; - - -- Type must be a first subtype - - elsif not Is_First_Subtype (Enumtype) then - Error_Msg_N ("cannot give enumeration rep clause for subtype", N); - return; - - -- Ignore duplicate rep clause - - elsif Has_Enumeration_Rep_Clause (Enumtype) then - Error_Msg_N ("duplicate enumeration rep clause ignored", N); - return; - - -- Don't allow rep clause for standard [wide_[wide_]]character - - elsif Root_Type (Enumtype) = Standard_Character - or else Root_Type (Enumtype) = Standard_Wide_Character - or else Root_Type (Enumtype) = Standard_Wide_Wide_Character - then - Error_Msg_N ("enumeration rep clause not allowed for this type", N); - return; - - -- Check that the expression is a proper aggregate (no parentheses) - - elsif Paren_Count (Aggr) /= 0 then - Error_Msg - ("extra parentheses surrounding aggregate not allowed", - First_Sloc (Aggr)); - return; - - -- All tests passed, so set rep clause in place - - 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) - - 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); - - -- Err signals that we found some incorrect entries processing - -- the list. The final checks for completeness and ordering are - -- skipped in this case. - - 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 - Flag_Non_Static_Expr - ("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 positions - -- 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 - - CR_Pragma : Node_Id := Empty; - -- Points to N_Pragma node if Complete_Representation pragma present - - 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); - AtM_Nod : Node_Id; - - Mod_Val : Uint; - pragma Warnings (Off, Mod_Val); - - begin - Check_Restriction (No_Obsolescent_Features, Mod_Clause (N)); - - if Warn_On_Obsolescent_Feature then - Error_Msg_N - ("mod clause is an obsolescent feature ('R'M 'J.8)?", N); - Error_Msg_N - ("\use alignment attribute definition clause instead?", N); - end if; - - if Present (P) then - Analyze_List (P); - end if; - - -- In ASIS_Mode 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 ASIS_Mode - 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; - - -- A representation like this applies to the base type - - 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 - - -- Pragma - - if Nkind (CC) = N_Pragma then - Analyze (CC); - - -- The only pragma of interest is Complete_Representation - - if Chars (CC) = Name_Complete_Representation then - CR_Pragma := CC; - end if; - - -- 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; - - -- 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 - exit when No (Component_Clause (Comp)); - 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. - - if No (Comp) then - Set_RM_Size (Rectype, Hbit + 1); - end if; - end if; - - -- Check missing components if Complete_Representation pragma appeared - - if Present (CR_Pragma) then - 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 - Error_Msg_NE - ("missing component clause for &", CR_Pragma, Comp); - end if; - end if; - - Next_Entity (Comp); - end loop; - 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 - Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent); - Ent : Entity_Id := Empty; - - 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 => - Ent := Entity (Nod); - - -- We need to look at the original node if it is different - -- from the node, since we may have rewritten things and - -- substituted an identifier representing the rewrite. - - if Original_Node (Nod) /= Nod then - Check_Expr_Constants (Original_Node (Nod)); - - -- If the node is an object declaration without initial - -- value, some code has been expanded, and the expression - -- is not constant, even if the constituents might be - -- acceptable, as in A'Address + offset. - - if Ekind (Ent) = E_Variable - and then Nkind (Declaration_Node (Ent)) - = N_Object_Declaration - and then - No (Expression (Declaration_Node (Ent))) - then - Error_Msg_NE - ("invalid address clause for initialized object &!", - Nod, U_Ent); - - -- If entity is constant, it may be the result of expanding - -- a check. We must verify that its declaration appears - -- before the object in question, else we also reject the - -- address clause. - - elsif Ekind (Ent) = E_Constant - and then In_Same_Source_Unit (Ent, U_Ent) - and then Sloc (Ent) > Loc_U_Ent - then - Error_Msg_NE - ("invalid address clause for initialized object &!", - Nod, U_Ent); - end if; - - return; - end if; - - -- Otherwise look at the identifier and see if it is OK - - 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 Sloc (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); - - if Comes_From_Source (Ent) then - Error_Msg_Name_1 := Chars (Ent); - Error_Msg_N - ("\reference to variable% not allowed" - & " ('R'M 13.1(22))!", Nod); - else - Error_Msg_N - ("non-static expression not allowed" - & " ('R'M 13.1(22))!", Nod); - end if; - end if; - - when N_Integer_Literal => - - -- If this is a rewritten unchecked conversion, in a system - -- where Address is an integer type, always use the base type - -- for a literal value. This is user-friendly and prevents - -- order-of-elaboration issues with instances of unchecked - -- conversion. - - if Nkind (Original_Node (Nod)) = N_Function_Call then - Set_Etype (Nod, Base_Type (Etype (Nod))); - end if; - - when 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; - - -- Dismiss cases for generic types or types 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)) - then - return; - - -- Check case of bit packed array - - elsif Is_Array_Type (UT) - and then Known_Static_Component_Size (UT) - and then Is_Bit_Packed_Array (UT) - then - declare - Asiz : Uint; - Indx : Node_Id; - Ityp : Entity_Id; - - begin - Asiz := Component_Size (UT); - Indx := First_Index (UT); - loop - Ityp := Etype (Indx); - - -- If non-static bound, then we are not in the business of - -- trying to check the length, and indeed an error will be - -- issued elsewhere, since sizes of non-static array types - -- cannot be set implicitly or explicitly. - - if not Is_Static_Subtype (Ityp) then - return; - end if; - - -- Otherwise accumulate next dimension - - Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) - - Expr_Value (Type_Low_Bound (Ityp)) + - Uint_1); - - Next_Index (Indx); - exit when No (Indx); - end loop; - - if Asiz <= Siz then - return; - else - Error_Msg_Uint_1 := Asiz; - Error_Msg_NE - ("size for& too small, minimum allowed is ^", N, T); - Set_Esize (T, Asiz); - Set_RM_Size (T, Asiz); - end if; - end; - - -- All other composite types are ignored - - elsif Is_Composite_Type (UT) then - return; - - -- For fixed-point types, don't check minimum if type is not frozen, - -- since we don't know all the characteristics of the type that can - -- affect the size (e.g. a specified small) till 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 - -- Ignore if specified size is correct for the type - - if Known_Esize (UT) and then Siz = Esize (UT) then - return; - end if; - - -- Otherwise get minimum size - - 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); - Set_Esize (T, M); - Set_RM_Size (T, M); - 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; - - ---------------- - -- 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 - or else Id = Attribute_External_Tag; - end; - end if; - end Is_Operational_Item; - - -------------------------------------- - -- Mark_Aliased_Address_As_Volatile -- - -------------------------------------- - - procedure Mark_Aliased_Address_As_Volatile (N : Node_Id) is - Ent : constant Entity_Id := Address_Aliased_Entity (N); - - begin - if Present (Ent) then - Set_Treat_As_Volatile (Ent); - end if; - end Mark_Aliased_Address_As_Volatile; - - ------------------ - -- 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; - R_Typ : constant Entity_Id := Root_Type (T); - - 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 (R_Typ) - or else R_Typ = Any_Type - then - return 0; - - -- Access types. Normally an access type cannot have a size smaller - -- than the size of System.Address. The exception is on VMS, where - -- we have short and long addresses, and it is possible for an access - -- type to have a short address size (and thus be less than the size - -- of System.Address itself). We simply skip the check for VMS, and - -- leave the back end to do the check. - - elsif Is_Access_Type (T) then - if OpenVMS_On_Target then - return 0; - else - return System_Address_Size; - end if; - - -- Floating-point types - - elsif Is_Floating_Point_Type (T) then - return UI_To_Int (Esize (R_Typ)); - - -- 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 : TSS_Name_Type) - is - Loc : constant Source_Ptr := Sloc (N); - Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam); - Subp_Id : Entity_Id; - Subp_Decl : Node_Id; - F : Entity_Id; - Etyp : Entity_Id; - - function Build_Spec return Node_Id; - -- Used for declaration and renaming declaration, so that this is - -- treated as a renaming_as_body. - - ---------------- - -- Build_Spec -- - ---------------- - - function Build_Spec return Node_Id is - begin - Subp_Id := Make_Defining_Identifier (Loc, Sname); - - return - 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)))), - - Result_Definition => - New_Reference_To (Etyp, Loc)); - end Build_Spec; - - -- Start of processing for New_Stream_Function - - begin - F := First_Formal (Subp); - Etyp := Etype (Subp); - - if not Is_Tagged_Type (Ent) then - Subp_Decl := - Make_Subprogram_Declaration (Loc, - Specification => Build_Spec); - Insert_Action (N, Subp_Decl); - end if; - - Subp_Decl := - Make_Subprogram_Renaming_Declaration (Loc, - Specification => Build_Spec, - Name => New_Reference_To (Subp, Loc)); - - if Is_Tagged_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 : TSS_Name_Type; - Out_P : Boolean := False) - is - Loc : constant Source_Ptr := Sloc (N); - Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam); - Subp_Id : Entity_Id; - Subp_Decl : Node_Id; - F : Entity_Id; - Etyp : Entity_Id; - - function Build_Spec return Node_Id; - -- Used for declaration and renaming declaration, so that this is - -- treated as a renaming_as_body. - - ---------------- - -- Build_Spec -- - ---------------- - - function Build_Spec return Node_Id is - begin - Subp_Id := Make_Defining_Identifier (Loc, Sname); - - return - 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)))); - end Build_Spec; - - -- Start of processing for New_Stream_Procedure - - begin - F := First_Formal (Subp); - Etyp := Etype (Next_Formal (F)); - - if not Is_Tagged_Type (Ent) then - Subp_Decl := - Make_Subprogram_Declaration (Loc, - Specification => Build_Spec); - Insert_Action (N, Subp_Decl); - end if; - - Subp_Decl := - Make_Subprogram_Renaming_Declaration (Loc, - Specification => Build_Spec, - Name => New_Reference_To (Subp, Loc)); - - if Is_Tagged_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; - - ------------------------ - -- Rep_Item_Too_Early -- - ------------------------ - - function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is - begin - -- Cannot apply rep items that are not operational items - -- to generic types - - if Is_Operational_Item (N) then - return False; - - elsif 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 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. Note that this is not considered a - -- serious error, since the effect is simply that we ignore the - -- representation clause in this case. - - -------------- - -- Too_Late -- - -------------- - - 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 - - -------------- - -- Same_Rep -- - -------------- - - 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); - - -- The number of discriminants may be different if the - -- derived type has fewer (constrained by values). The - -- invisible discriminants retain the representation of - -- the original, so the discrepancy does not per se - -- indicate a different representation. - - while Present (CD1) - and then Present (CD2) - 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 - -- reprsentation 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 := Standard_Character_Size; -- May be > 8 on some targets - - 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 := Standard_Character_Size; -- May be > 8 on some targets - - 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). - -- This is only done if the appropriate warning is active - - if Warn_On_Unchecked_Conversion then - Unchecked_Conversions.Append - (New_Val => UC_Entry' - (Enode => N, - Source => Source, - Target => Target)); - - -- If both sizes are known statically now, then back end annotation - -- is not required to do a proper check but if either size is not - -- known statically, then we need the annotation. - - if Known_Static_RM_Size (Source) - and then Known_Static_RM_Size (Target) - then - null; - else - Back_Annotate_Rep_Info := True; - end if; - end if; - - -- If unchecked conversion to access type, and access type is - -- declared in the same unit as the unchecked conversion, then - -- set the No_Strict_Aliasing flag (no strict aliasing is - -- implicit in this situation). - - if Is_Access_Type (Target) and then - In_Same_Source_Unit (Target, N) - then - Set_No_Strict_Aliasing (Implementation_Base_Type (Target)); - end if; - - -- Generate N_Validate_Unchecked_Conversion node for back end in - -- case the back end needs to perform special validation checks. - - -- Shouldn't this be in exp_ch13, since the check only gets done - -- if we have full expansion and the back end is called ??? - - Vnode := - Make_Validate_Unchecked_Conversion (Sloc (N)); - Set_Source_Type (Vnode, Source); - Set_Target_Type (Vnode, Target); - - -- If the unchecked conversion node is in a list, just insert before - -- it. If not we have some strange case, not worth bothering about. - - if Is_List_Member (N) then - 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 Serious_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 - 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_Unsigned_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; - 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 Serious_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 - 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; - end if; - end; - end if; - end; - end if; - end; - end loop; - end Validate_Unchecked_Conversions; - -end Sem_Ch13; |