X-Git-Url: http://git.sourceforge.jp/view?p=pf3gnuchains%2Fgcc-fork.git;a=blobdiff_plain;f=gcc%2Fada%2Fsem_ch13.adb;h=6a4d514958cb7755c39cf994f34b334a1aff3fce;hp=8f4d6eeb1ec024d45b1a4921bf291c98d5e90f97;hb=7717ea00902734bd90371e34af23d0b73287f875;hpb=e777155693d6c822bf12ef4958b3c4ab1fea9ec6 diff --git a/gcc/ada/sem_ch13.adb b/gcc/ada/sem_ch13.adb index 8f4d6eeb1ec..6a4d514958c 100644 --- a/gcc/ada/sem_ch13.adb +++ b/gcc/ada/sem_ch13.adb @@ -6,7 +6,7 @@ -- -- -- B o d y -- -- -- --- Copyright (C) 1992-2009, Free Software Foundation, Inc. -- +-- Copyright (C) 1992-2010, 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- -- @@ -26,7 +26,9 @@ with Atree; use Atree; with Checks; use Checks; with Einfo; use Einfo; +with Elists; use Elists; with Errout; use Errout; +with Exp_Disp; use Exp_Disp; with Exp_Tss; use Exp_Tss; with Exp_Util; use Exp_Util; with Lib; use Lib; @@ -40,6 +42,7 @@ with Rident; use Rident; with Rtsfind; use Rtsfind; with Sem; use Sem; with Sem_Aux; use Sem_Aux; +with Sem_Ch3; use Sem_Ch3; with Sem_Ch8; use Sem_Ch8; with Sem_Eval; use Sem_Eval; with Sem_Res; use Sem_Res; @@ -49,7 +52,6 @@ with Sem_Warn; use Sem_Warn; 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; @@ -72,10 +74,6 @@ package body Sem_Ch13 is -- 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 have 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 @@ -87,9 +85,6 @@ package body Sem_Ch13 is -- 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 New_Stream_Subprogram (N : Node_Id; Ent : Entity_Id; @@ -110,6 +105,16 @@ package body Sem_Ch13 is -- renaming_as_body. For tagged types, the specification is one of the -- primitive specs. + procedure Set_Biased + (E : Entity_Id; + N : Node_Id; + Msg : String; + Biased : Boolean := True); + -- If Biased is True, sets Has_Biased_Representation flag for E, and + -- outputs a warning message at node N if Warn_On_Biased_Representation is + -- is True. This warning inserts the string Msg to describe the construct + -- causing biasing. + ---------------------------------------------- -- Table for Validate_Unchecked_Conversions -- ---------------------------------------------- @@ -164,6 +169,9 @@ package body Sem_Ch13 is Y : Entity_Id; -- The entity of the object being overlaid + + Off : Boolean; + -- Whether the address is offseted within Y end record; package Address_Clause_Checks is new Table.Table ( @@ -174,297 +182,421 @@ package body Sem_Ch13 is Table_Increment => 200, Table_Name => "Address_Clause_Checks"); - ---------------------------- - -- 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 - P : Node_Id; - - begin - P := Prefix (N); - while Nkind_In (P, N_Selected_Component, N_Indexed_Component) loop - P := Prefix (P); - end loop; - - if Is_Entity_Name (P) then - return Entity (P); - end if; - end; - end if; - - return Empty; - end Address_Aliased_Entity; - ----------------------------------------- -- Adjust_Record_For_Reverse_Bit_Order -- ----------------------------------------- procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is - Max_Machine_Scalar_Size : constant Uint := - UI_From_Int - (Standard_Long_Long_Integer_Size); - -- We use this as the maximum machine scalar size in the sense of AI-133 - - Num_CC : Natural; - Comp : Entity_Id; - SSU : constant Uint := UI_From_Int (System_Storage_Unit); + Comp : Node_Id; + CC : Node_Id; begin - -- This first loop through components does two things. First it deals - -- with the case of components with component clauses whose length is - -- greater than the maximum machine scalar size (either accepting them - -- or rejecting as needed). Second, it counts the number of components - -- with component clauses whose length does not exceed this maximum for - -- later processing. - - Num_CC := 0; - Comp := First_Component_Or_Discriminant (R); - while Present (Comp) loop - declare - CC : constant Node_Id := Component_Clause (Comp); + -- Processing depends on version of Ada - begin - if Present (CC) then - declare - Fbit : constant Uint := Static_Integer (First_Bit (CC)); + -- For Ada 95, we just renumber bits within a storage unit. We do the + -- same for Ada 83 mode, since we recognize pragma Bit_Order in Ada 83, + -- and are free to add this extension. - begin - -- Case of component with size > max machine scalar + if Ada_Version < Ada_2005 then + Comp := First_Component_Or_Discriminant (R); + while Present (Comp) loop + CC := Component_Clause (Comp); - if Esize (Comp) > Max_Machine_Scalar_Size then + -- If component clause is present, then deal with the non-default + -- bit order case for Ada 95 mode. - -- Must begin on byte boundary + -- We only do this processing for the base type, and in fact that + -- is important, since otherwise if there are record subtypes, we + -- could reverse the bits once for each subtype, which is wrong. - if Fbit mod SSU /= 0 then - Error_Msg_N - ("illegal first bit value for reverse bit order", - First_Bit (CC)); - Error_Msg_Uint_1 := SSU; - Error_Msg_Uint_2 := Max_Machine_Scalar_Size; + if Present (CC) + and then Ekind (R) = E_Record_Type + then + declare + CFB : constant Uint := Component_Bit_Offset (Comp); + CSZ : constant Uint := Esize (Comp); + CLC : constant Node_Id := Component_Clause (Comp); + Pos : constant Node_Id := Position (CLC); + FB : constant Node_Id := First_Bit (CLC); - Error_Msg_N - ("\must be a multiple of ^ if size greater than ^", - First_Bit (CC)); + Storage_Unit_Offset : constant Uint := + CFB / System_Storage_Unit; - -- Must end on byte boundary + Start_Bit : constant Uint := + CFB mod System_Storage_Unit; - elsif Esize (Comp) mod SSU /= 0 then - Error_Msg_N - ("illegal last bit value for reverse bit order", - Last_Bit (CC)); - Error_Msg_Uint_1 := SSU; - Error_Msg_Uint_2 := Max_Machine_Scalar_Size; + begin + -- Cases where field goes over storage unit boundary - Error_Msg_N - ("\must be a multiple of ^ if size greater than ^", - Last_Bit (CC)); + if Start_Bit + CSZ > System_Storage_Unit then - -- OK, give warning if enabled + -- Allow multi-byte field but generate warning - elsif Warn_On_Reverse_Bit_Order then + if Start_Bit mod System_Storage_Unit = 0 + and then CSZ mod System_Storage_Unit = 0 + then Error_Msg_N ("multi-byte field specified with non-standard" - & " Bit_Order?", CC); + & " Bit_Order?", CLC); if Bytes_Big_Endian then Error_Msg_N - ("\bytes are not reversed " - & "(component is big-endian)?", CC); + ("bytes are not reversed " + & "(component is big-endian)?", CLC); else Error_Msg_N - ("\bytes are not reversed " - & "(component is little-endian)?", CC); + ("bytes are not reversed " + & "(component is little-endian)?", CLC); end if; + + -- Do not allow non-contiguous field + + else + Error_Msg_N + ("attempt to specify non-contiguous field " + & "not permitted", CLC); + Error_Msg_N + ("\caused by non-standard Bit_Order " + & "specified", CLC); + Error_Msg_N + ("\consider possibility of using " + & "Ada 2005 mode here", CLC); end if; - -- Case where size is not greater than max machine - -- scalar. For now, we just count these. + -- Case where field fits in one storage unit else - Num_CC := Num_CC + 1; + -- Give warning if suspicious component clause + + if Intval (FB) >= System_Storage_Unit + and then Warn_On_Reverse_Bit_Order + then + Error_Msg_N + ("?Bit_Order clause does not affect " & + "byte ordering", Pos); + Error_Msg_Uint_1 := + Intval (Pos) + Intval (FB) / + System_Storage_Unit; + Error_Msg_N + ("?position normalized to ^ before bit " & + "order interpreted", Pos); + end if; + + -- Here is where we fix up the Component_Bit_Offset value + -- to account for the reverse bit order. Some examples of + -- what needs to be done are: + + -- First_Bit .. Last_Bit Component_Bit_Offset + -- old new old new + + -- 0 .. 0 7 .. 7 0 7 + -- 0 .. 1 6 .. 7 0 6 + -- 0 .. 2 5 .. 7 0 5 + -- 0 .. 7 0 .. 7 0 4 + + -- 1 .. 1 6 .. 6 1 6 + -- 1 .. 4 3 .. 6 1 3 + -- 4 .. 7 0 .. 3 4 0 + + -- The rule is that the first bit is is obtained by + -- subtracting the old ending bit from storage_unit - 1. + + Set_Component_Bit_Offset + (Comp, + (Storage_Unit_Offset * System_Storage_Unit) + + (System_Storage_Unit - 1) - + (Start_Bit + CSZ - 1)); + + Set_Normalized_First_Bit + (Comp, + Component_Bit_Offset (Comp) mod + System_Storage_Unit); end if; end; end if; - end; - Next_Component_Or_Discriminant (Comp); - end loop; + Next_Component_Or_Discriminant (Comp); + end loop; - -- We need to sort the component clauses on the basis of the Position - -- values in the clause, so we can group clauses with the same Position. - -- together to determine the relevant machine scalar size. + -- For Ada 2005, we do machine scalar processing, as fully described In + -- AI-133. This involves gathering all components which start at the + -- same byte offset and processing them together. Same approach is still + -- valid in later versions including Ada 2012. - declare - Comps : array (0 .. Num_CC) of Entity_Id; - -- Array to collect component and discriminant entities. The data - -- starts at index 1, the 0'th entry is for the sort routine. + else + declare + Max_Machine_Scalar_Size : constant Uint := + UI_From_Int + (Standard_Long_Long_Integer_Size); + -- We use this as the maximum machine scalar size + + Num_CC : Natural; + SSU : constant Uint := UI_From_Int (System_Storage_Unit); + + begin + -- This first loop through components does two things. First it + -- deals with the case of components with component clauses whose + -- length is greater than the maximum machine scalar size (either + -- accepting them or rejecting as needed). Second, it counts the + -- number of components with component clauses whose length does + -- not exceed this maximum for later processing. + + Num_CC := 0; + Comp := First_Component_Or_Discriminant (R); + while Present (Comp) loop + CC := Component_Clause (Comp); - function CP_Lt (Op1, Op2 : Natural) return Boolean; - -- Compare routine for Sort + if Present (CC) then + declare + Fbit : constant Uint := + Static_Integer (First_Bit (CC)); - procedure CP_Move (From : Natural; To : Natural); - -- Move routine for Sort + begin + -- Case of component with size > max machine scalar - package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt); + if Esize (Comp) > Max_Machine_Scalar_Size then - Start : Natural; - Stop : Natural; - -- Start and stop positions in component list of set of components - -- with the same starting position (that constitute components in - -- a single machine scalar). + -- Must begin on byte boundary - MaxL : Uint; - -- Maximum last bit value of any component in this set + if Fbit mod SSU /= 0 then + Error_Msg_N + ("illegal first bit value for " + & "reverse bit order", + First_Bit (CC)); + Error_Msg_Uint_1 := SSU; + Error_Msg_Uint_2 := Max_Machine_Scalar_Size; - MSS : Uint; - -- Corresponding machine scalar size + Error_Msg_N + ("\must be a multiple of ^ " + & "if size greater than ^", + First_Bit (CC)); - ----------- - -- CP_Lt -- - ----------- + -- Must end on byte boundary - function CP_Lt (Op1, Op2 : Natural) return Boolean is - begin - return Position (Component_Clause (Comps (Op1))) < - Position (Component_Clause (Comps (Op2))); - end CP_Lt; + elsif Esize (Comp) mod SSU /= 0 then + Error_Msg_N + ("illegal last bit value for " + & "reverse bit order", + Last_Bit (CC)); + Error_Msg_Uint_1 := SSU; + Error_Msg_Uint_2 := Max_Machine_Scalar_Size; - ------------- - -- CP_Move -- - ------------- + Error_Msg_N + ("\must be a multiple of ^ if size " + & "greater than ^", + Last_Bit (CC)); - procedure CP_Move (From : Natural; To : Natural) is - begin - Comps (To) := Comps (From); - end CP_Move; + -- OK, give warning if enabled - begin - -- Collect the component clauses + elsif Warn_On_Reverse_Bit_Order then + Error_Msg_N + ("multi-byte field specified with " + & " non-standard Bit_Order?", CC); - Num_CC := 0; - Comp := First_Component_Or_Discriminant (R); - while Present (Comp) loop - if Present (Component_Clause (Comp)) - and then Esize (Comp) <= Max_Machine_Scalar_Size - then - Num_CC := Num_CC + 1; - Comps (Num_CC) := Comp; - end if; + if Bytes_Big_Endian then + Error_Msg_N + ("\bytes are not reversed " + & "(component is big-endian)?", CC); + else + Error_Msg_N + ("\bytes are not reversed " + & "(component is little-endian)?", CC); + end if; + end if; - Next_Component_Or_Discriminant (Comp); - end loop; + -- Case where size is not greater than max machine + -- scalar. For now, we just count these. - -- Sort by ascending position number - - Sorting.Sort (Num_CC); - - -- We now have all the components whose size does not exceed the max - -- machine scalar value, sorted by starting position. In this loop - -- we gather groups of clauses starting at the same position, to - -- process them in accordance with Ada 2005 AI-133. - - Stop := 0; - while Stop < Num_CC loop - Start := Stop + 1; - Stop := Start; - MaxL := - Static_Integer (Last_Bit (Component_Clause (Comps (Start)))); - while Stop < Num_CC loop - if Static_Integer - (Position (Component_Clause (Comps (Stop + 1)))) = - Static_Integer - (Position (Component_Clause (Comps (Stop)))) - then - Stop := Stop + 1; - MaxL := - UI_Max - (MaxL, - Static_Integer - (Last_Bit (Component_Clause (Comps (Stop))))); - else - exit; + else + Num_CC := Num_CC + 1; + end if; + end; end if; + + Next_Component_Or_Discriminant (Comp); end loop; - -- Now we have a group of component clauses from Start to Stop - -- whose positions are identical, and MaxL is the maximum last bit - -- value of any of these components. + -- We need to sort the component clauses on the basis of the + -- Position values in the clause, so we can group clauses with + -- the same Position. together to determine the relevant machine + -- scalar size. - -- We need to determine the corresponding machine scalar size. - -- This loop assumes that machine scalar sizes are even, and that - -- each possible machine scalar has twice as many bits as the - -- next smaller one. + Sort_CC : declare + Comps : array (0 .. Num_CC) of Entity_Id; + -- Array to collect component and discriminant entities. The + -- data starts at index 1, the 0'th entry is for the sort + -- routine. - MSS := Max_Machine_Scalar_Size; - while MSS mod 2 = 0 - and then (MSS / 2) >= SSU - and then (MSS / 2) > MaxL - loop - MSS := MSS / 2; - end loop; + function CP_Lt (Op1, Op2 : Natural) return Boolean; + -- Compare routine for Sort - -- Here is where we fix up the Component_Bit_Offset value to - -- account for the reverse bit order. Some examples of what needs - -- to be done for the case of a machine scalar size of 8 are: + procedure CP_Move (From : Natural; To : Natural); + -- Move routine for Sort - -- First_Bit .. Last_Bit Component_Bit_Offset - -- old new old new + package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt); - -- 0 .. 0 7 .. 7 0 7 - -- 0 .. 1 6 .. 7 0 6 - -- 0 .. 2 5 .. 7 0 5 - -- 0 .. 7 0 .. 7 0 4 + Start : Natural; + Stop : Natural; + -- Start and stop positions in the component list of the set of + -- components with the same starting position (that constitute + -- components in a single machine scalar). - -- 1 .. 1 6 .. 6 1 6 - -- 1 .. 4 3 .. 6 1 3 - -- 4 .. 7 0 .. 3 4 0 + MaxL : Uint; + -- Maximum last bit value of any component in this set - -- The general rule is that the first bit is obtained by - -- subtracting the old ending bit from machine scalar size - 1. + MSS : Uint; + -- Corresponding machine scalar size - for C in Start .. Stop loop - declare - Comp : constant Entity_Id := Comps (C); - CC : constant Node_Id := Component_Clause (Comp); - LB : constant Uint := Static_Integer (Last_Bit (CC)); - NFB : constant Uint := MSS - Uint_1 - LB; - NLB : constant Uint := NFB + Esize (Comp) - 1; - Pos : constant Uint := Static_Integer (Position (CC)); + ----------- + -- CP_Lt -- + ----------- + function CP_Lt (Op1, Op2 : Natural) return Boolean is begin - if Warn_On_Reverse_Bit_Order then - Error_Msg_Uint_1 := MSS; - Error_Msg_N - ("info: reverse bit order in machine " & - "scalar of length^?", First_Bit (CC)); - Error_Msg_Uint_1 := NFB; - Error_Msg_Uint_2 := NLB; + return Position (Component_Clause (Comps (Op1))) < + Position (Component_Clause (Comps (Op2))); + end CP_Lt; - if Bytes_Big_Endian then - Error_Msg_NE - ("?\info: big-endian range for " - & "component & is ^ .. ^", - First_Bit (CC), Comp); + ------------- + -- CP_Move -- + ------------- + + procedure CP_Move (From : Natural; To : Natural) is + begin + Comps (To) := Comps (From); + end CP_Move; + + -- Start of processing for Sort_CC + + begin + -- Collect the component clauses + + Num_CC := 0; + Comp := First_Component_Or_Discriminant (R); + while Present (Comp) loop + if Present (Component_Clause (Comp)) + and then Esize (Comp) <= Max_Machine_Scalar_Size + then + Num_CC := Num_CC + 1; + Comps (Num_CC) := Comp; + end if; + + Next_Component_Or_Discriminant (Comp); + end loop; + + -- Sort by ascending position number + + Sorting.Sort (Num_CC); + + -- We now have all the components whose size does not exceed + -- the max machine scalar value, sorted by starting position. + -- In this loop we gather groups of clauses starting at the + -- same position, to process them in accordance with AI-133. + + Stop := 0; + while Stop < Num_CC loop + Start := Stop + 1; + Stop := Start; + MaxL := + Static_Integer + (Last_Bit (Component_Clause (Comps (Start)))); + while Stop < Num_CC loop + if Static_Integer + (Position (Component_Clause (Comps (Stop + 1)))) = + Static_Integer + (Position (Component_Clause (Comps (Stop)))) + then + Stop := Stop + 1; + MaxL := + UI_Max + (MaxL, + Static_Integer + (Last_Bit + (Component_Clause (Comps (Stop))))); else - Error_Msg_NE - ("?\info: little-endian range " - & "for component & is ^ .. ^", - First_Bit (CC), Comp); + exit; end if; - end if; + end loop; - Set_Component_Bit_Offset (Comp, Pos * SSU + NFB); - Set_Normalized_First_Bit (Comp, NFB mod SSU); - end; - end loop; - end loop; - end; + -- Now we have a group of component clauses from Start to + -- Stop whose positions are identical, and MaxL is the + -- maximum last bit value of any of these components. + + -- We need to determine the corresponding machine scalar + -- size. This loop assumes that machine scalar sizes are + -- even, and that each possible machine scalar has twice + -- as many bits as the next smaller one. + + MSS := Max_Machine_Scalar_Size; + while MSS mod 2 = 0 + and then (MSS / 2) >= SSU + and then (MSS / 2) > MaxL + loop + MSS := MSS / 2; + end loop; + + -- Here is where we fix up the Component_Bit_Offset value + -- to account for the reverse bit order. Some examples of + -- what needs to be done for the case of a machine scalar + -- size of 8 are: + + -- First_Bit .. Last_Bit Component_Bit_Offset + -- old new old new + + -- 0 .. 0 7 .. 7 0 7 + -- 0 .. 1 6 .. 7 0 6 + -- 0 .. 2 5 .. 7 0 5 + -- 0 .. 7 0 .. 7 0 4 + + -- 1 .. 1 6 .. 6 1 6 + -- 1 .. 4 3 .. 6 1 3 + -- 4 .. 7 0 .. 3 4 0 + + -- The rule is that the first bit is obtained by subtracting + -- the old ending bit from machine scalar size - 1. + + for C in Start .. Stop loop + declare + Comp : constant Entity_Id := Comps (C); + CC : constant Node_Id := + Component_Clause (Comp); + LB : constant Uint := + Static_Integer (Last_Bit (CC)); + NFB : constant Uint := MSS - Uint_1 - LB; + NLB : constant Uint := NFB + Esize (Comp) - 1; + Pos : constant Uint := + Static_Integer (Position (CC)); + + begin + if Warn_On_Reverse_Bit_Order then + Error_Msg_Uint_1 := MSS; + Error_Msg_N + ("info: reverse bit order in machine " & + "scalar of length^?", First_Bit (CC)); + Error_Msg_Uint_1 := NFB; + Error_Msg_Uint_2 := NLB; + + if Bytes_Big_Endian then + Error_Msg_NE + ("?\info: big-endian range for " + & "component & is ^ .. ^", + First_Bit (CC), Comp); + else + Error_Msg_NE + ("?\info: little-endian range " + & "for component & is ^ .. ^", + First_Bit (CC), Comp); + end if; + end if; + + Set_Component_Bit_Offset (Comp, Pos * SSU + NFB); + Set_Normalized_First_Bit (Comp, NFB mod SSU); + end; + end loop; + end loop; + end Sort_CC; + end; + end if; end Adjust_Record_For_Reverse_Bit_Order; -------------------------------------- @@ -702,8 +834,7 @@ package body Sem_Ch13 is -- affect legality (except possibly to be rejected because they -- are incompatible with the compilation target). - when Attribute_Address | - Attribute_Alignment | + when Attribute_Alignment | Attribute_Bit_Order | Attribute_Component_Size | Attribute_Machine_Radix | @@ -731,7 +862,8 @@ package body Sem_Ch13 is Attribute_Write => null; - -- Other cases are errors, which will be caught below + -- Other cases are errors ("attribute& cannot be set with + -- definition clause"), which will be caught below. when others => null; @@ -825,6 +957,18 @@ package body Sem_Ch13 is Analyze_And_Resolve (Expr, RTE (RE_Address)); + -- Even when ignoring rep clauses we need to indicate that the + -- entity has an address clause and thus it is legal to declare + -- it imported. + + if Ignore_Rep_Clauses then + if Ekind_In (U_Ent, E_Variable, E_Constant) then + Record_Rep_Item (U_Ent, N); + end if; + + return; + end if; + if Present (Address_Clause (U_Ent)) then Error_Msg_N ("address already given for &", Nam); @@ -906,24 +1050,27 @@ package body Sem_Ch13 is Ekind (U_Ent) = E_Constant then declare - Expr : constant Node_Id := Expression (N); - Aent : constant Entity_Id := Address_Aliased_Entity (Expr); - Ent_Y : constant Entity_Id := Find_Overlaid_Object (N); + Expr : constant Node_Id := Expression (N); + O_Ent : Entity_Id; + Off : Boolean; begin - -- Exported variables cannot have an address clause, - -- because this cancels the effect of the pragma Export + -- 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); return; + end if; + + Find_Overlaid_Entity (N, O_Ent, Off); -- Overlaying controlled objects is erroneous - elsif Present (Aent) - and then (Has_Controlled_Component (Etype (Aent)) - or else Is_Controlled (Etype (Aent))) + if Present (O_Ent) + and then (Has_Controlled_Component (Etype (O_Ent)) + or else Is_Controlled (Etype (O_Ent))) then Error_Msg_N ("?cannot overlay with controlled object", Expr); @@ -934,9 +1081,9 @@ package body Sem_Ch13 is Reason => PE_Overlaid_Controlled_Object)); return; - elsif Present (Aent) + elsif Present (O_Ent) and then Ekind (U_Ent) = E_Constant - and then not Is_Constant_Object (Aent) + and then not Is_Constant_Object (O_Ent) then Error_Msg_N ("constant overlays a variable?", Expr); @@ -964,10 +1111,15 @@ package body Sem_Ch13 is -- Here we are checking for explicit overlap of one variable -- by another, and if we find this then mark the overlapped -- variable as also being volatile to prevent unwanted - -- optimizations. + -- optimizations. This is a significant pessimization so + -- avoid it when there is an offset, i.e. when the object + -- is composite; they cannot be optimized easily anyway. - if Present (Ent_Y) then - Set_Treat_As_Volatile (Ent_Y); + if Present (O_Ent) + and then Is_Object (O_Ent) + and then not Off + then + Set_Treat_As_Volatile (O_Ent); end if; -- Legality checks on the address clause for initialized @@ -1015,53 +1167,48 @@ package body Sem_Ch13 is -- the variable, it is somewhere else. Kill_Size_Check_Code (U_Ent); - end; - - -- If the address clause is of the form: - - -- for Y'Address use X'Address - -- or + -- If the address clause is of the form: - -- Const : constant Address := X'Address; - -- ... - -- for Y'Address use Const; + -- for Y'Address use X'Address - -- then we make an entry in the table for checking the size and - -- alignment of the overlaying variable. We defer this check - -- till after code generation to take full advantage of the - -- annotation done by the back end. This entry is only made if - -- we have not already posted a warning about size/alignment - -- (some warnings of this type are posted in Checks), and if - -- the address clause comes from source. + -- or - if Address_Clause_Overlay_Warnings - and then Comes_From_Source (N) - then - declare - Ent_X : Entity_Id := Empty; - Ent_Y : Entity_Id := Empty; + -- Const : constant Address := X'Address; + -- ... + -- for Y'Address use Const; - begin - Ent_Y := Find_Overlaid_Object (N); + -- then we make an entry in the table for checking the size + -- and alignment of the overlaying variable. We defer this + -- check till after code generation to take full advantage + -- of the annotation done by the back end. This entry is + -- only made if the address clause comes from source. + -- If the entity has a generic type, the check will be + -- performed in the instance if the actual type justifies + -- it, and we do not insert the clause in the table to + -- prevent spurious warnings. - if Present (Ent_Y) and then Is_Entity_Name (Name (N)) then - Ent_X := Entity (Name (N)); - Address_Clause_Checks.Append ((N, Ent_X, Ent_Y)); + if Address_Clause_Overlay_Warnings + and then Comes_From_Source (N) + and then Present (O_Ent) + and then Is_Object (O_Ent) + then + if not Is_Generic_Type (Etype (U_Ent)) then + Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off)); + end if; - -- If variable overlays a constant view, and we are - -- warning on overlays, then mark the variable as - -- overlaying a constant (we will give warnings later - -- if this variable is assigned). + -- If variable overlays a constant view, and we are + -- warning on overlays, then mark the variable as + -- overlaying a constant (we will give warnings later + -- if this variable is assigned). - if Is_Constant_Object (Ent_Y) - and then Ekind (Ent_X) = E_Variable - then - Set_Overlays_Constant (Ent_X); - end if; + if Is_Constant_Object (O_Ent) + and then Ekind (U_Ent) = E_Variable + then + Set_Overlays_Constant (U_Ent); end if; - end; - end if; + end if; + end; -- Not a valid entity for an address clause @@ -1076,7 +1223,7 @@ package body Sem_Ch13 is -- Alignment attribute definition clause - when Attribute_Alignment => Alignment_Block : declare + when Attribute_Alignment => Alignment : declare Align : constant Uint := Get_Alignment_Value (Expr); begin @@ -1095,8 +1242,17 @@ package body Sem_Ch13 is elsif Align /= No_Uint then Set_Has_Alignment_Clause (U_Ent); Set_Alignment (U_Ent, Align); + + -- For an array type, U_Ent is the first subtype. In that case, + -- also set the alignment of the anonymous base type so that + -- other subtypes (such as the itypes for aggregates of the + -- type) also receive the expected alignment. + + if Is_Array_Type (U_Ent) then + Set_Alignment (Base_Type (U_Ent), Align); + end if; end if; - end Alignment_Block; + end Alignment; --------------- -- Bit_Order -- @@ -1136,6 +1292,7 @@ package body Sem_Ch13 is when Attribute_Component_Size => Component_Size_Case : declare Csize : constant Uint := Static_Integer (Expr); + Ctyp : Entity_Id; Btype : Entity_Id; Biased : Boolean; New_Ctyp : Entity_Id; @@ -1148,23 +1305,17 @@ package body Sem_Ch13 is end if; Btype := Base_Type (U_Ent); + Ctyp := Component_Type (Btype); if Has_Component_Size_Clause (Btype) then Error_Msg_N ("component size clause for& previously given", Nam); - elsif Csize /= No_Uint then - Check_Size (Expr, Component_Type (Btype), Csize, Biased); + elsif Rep_Item_Too_Early (Btype, N) then + null; - 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; + elsif Csize /= No_Uint then + Check_Size (Expr, Ctyp, Csize, Biased); -- For the biased case, build a declaration for a subtype -- that will be used to represent the biased subtype that @@ -1193,17 +1344,11 @@ package body Sem_Ch13 is 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); - - if Warn_On_Biased_Representation then - Error_Msg_N - ("?component size clause forces biased " - & "representation", N); - end if; + Set_Biased (New_Ctyp, N, "component size clause"); end if; Set_Component_Size (Btype, Csize); @@ -1220,8 +1365,19 @@ package body Sem_Ch13 is end if; end if; + -- Deal with warning on overridden size + + if Warn_On_Overridden_Size + and then Has_Size_Clause (Ctyp) + and then RM_Size (Ctyp) /= Csize + then + Error_Msg_NE + ("?component size overrides size clause for&", + N, Ctyp); + end if; + Set_Has_Component_Size_Clause (Btype, True); - Set_Has_Non_Standard_Rep (Btype, True); + Set_Has_Non_Standard_Rep (Btype, True); end if; end Component_Size_Case; @@ -1244,7 +1400,7 @@ package body Sem_Ch13 is if VM_Target = No_VM then Set_Has_External_Tag_Rep_Clause (U_Ent); - elsif not Inspector_Mode then + else Error_Msg_Name_1 := Attr; Error_Msg_N ("% attribute unsupported in this configuration", Nam); @@ -1386,6 +1542,17 @@ package body Sem_Ch13 is ("size cannot be given for unconstrained array", Nam); elsif Size /= No_Uint then + + if VM_Target /= No_VM and then not GNAT_Mode then + + -- Size clause is not handled properly on VM targets. + -- Display a warning unless we are in GNAT mode, in which + -- case this is useless. + + Error_Msg_N + ("?size clauses are ignored in this configuration", N); + end if; + if Is_Type (U_Ent) then Etyp := U_Ent; else @@ -1403,12 +1570,7 @@ package body Sem_Ch13 is or else Has_Small_Clause (U_Ent) then Check_Size (Expr, Etyp, Size, Biased); - Set_Has_Biased_Representation (U_Ent, Biased); - - if Biased and Warn_On_Biased_Representation then - Error_Msg_N - ("?size clause forces biased representation", N); - end if; + Set_Biased (U_Ent, N, "size clause", Biased); end if; -- For types set RM_Size and Esize if possible @@ -1535,8 +1697,8 @@ package body Sem_Ch13 is Nam); return; - elsif Ekind (U_Ent) /= E_Access_Type - and then Ekind (U_Ent) /= E_General_Access_Type + elsif not + Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type) then Error_Msg_N ("storage pool can only be given for access types", Nam); @@ -1593,9 +1755,7 @@ package body Sem_Ch13 is if not Is_Entity_Name (Expr) and then Is_Object_Reference (Expr) then - Pool := - Make_Defining_Identifier (Loc, - Chars => New_Internal_Name ('P')); + Pool := Make_Temporary (Loc, 'P', Expr); declare Rnode : constant Node_Id := @@ -1603,7 +1763,7 @@ package body Sem_Ch13 is Defining_Identifier => Pool, Subtype_Mark => New_Occurrence_Of (Etype (Expr), Loc), - Name => Expr); + Name => Expr); begin Insert_Before (N, Rnode); @@ -1663,8 +1823,7 @@ package body Sem_Ch13 is Error_Msg_N ("storage size clause for task is an " & "obsolescent feature (RM J.9)?", N); - Error_Msg_N - ("\use Storage_Size pragma instead?", N); + Error_Msg_N ("\use Storage_Size pragma instead?", N); end if; FOnly := True; @@ -1692,7 +1851,7 @@ package body Sem_Ch13 is return; end if; - if Compile_Time_Known_Value (Expr) + if Is_OK_Static_Expression (Expr) and then Expr_Value (Expr) = 0 then Set_No_Pool_Assigned (Btype); @@ -1785,12 +1944,7 @@ package body Sem_Ch13 is else if Is_Elementary_Type (U_Ent) then Check_Size (Expr, U_Ent, Size, Biased); - Set_Has_Biased_Representation (U_Ent, Biased); - - if Biased and Warn_On_Biased_Representation then - Error_Msg_N - ("?value size clause forces biased representation", N); - end if; + Set_Biased (U_Ent, N, "value size clause", Biased); end if; Set_RM_Size (U_Ent, Size); @@ -1930,10 +2084,16 @@ package body Sem_Ch13 is 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)); + Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer)); + Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer)); + -- Allowed range of universal integer (= allowed range of enum lit vals) + Min : Uint; Max : Uint; + -- Minimum and maximum values of entries + + Max_Node : Node_Id; + -- Pointer to node for literal providing max value begin if Ignore_Rep_Clauses then @@ -2092,7 +2252,7 @@ package body Sem_Ch13 is Err := True; end if; - Set_Enumeration_Rep_Expr (Elit, Choice); + Set_Enumeration_Rep_Expr (Elit, Expression (Assoc)); Expr := Expression (Assoc); Val := Static_Integer (Expr); @@ -2138,15 +2298,16 @@ package body Sem_Ch13 is if Max /= No_Uint and then Val <= Max then Error_Msg_NE ("enumeration value for& not ordered!", - Enumeration_Rep_Expr (Elit), Elit); + Enumeration_Rep_Expr (Elit), Elit); end if; + Max_Node := Enumeration_Rep_Expr (Elit); 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 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)); @@ -2163,18 +2324,32 @@ package body Sem_Ch13 is begin if Has_Size_Clause (Enumtype) then - if Esize (Enumtype) >= Minsize then + + -- All OK, if size is OK now + + if RM_Size (Enumtype) >= Minsize then null; else + -- Try if we can get by with biasing + Minsize := UI_From_Int (Minimum_Size (Enumtype, Biased => True)); - if Esize (Enumtype) < Minsize then - Error_Msg_N ("previously given size is too small", N); + -- Error message if even biasing does not work + + if RM_Size (Enumtype) < Minsize then + Error_Msg_Uint_1 := RM_Size (Enumtype); + Error_Msg_Uint_2 := Max; + Error_Msg_N + ("previously given size (^) is too small " + & "for this value (^)", Max_Node); + + -- If biasing worked, indicate that we now have biased rep else - Set_Has_Biased_Representation (Enumtype); + Set_Biased + (Enumtype, Size_Clause (Enumtype), "size clause"); end if; end if; @@ -2205,53 +2380,153 @@ package body Sem_Ch13 is 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 + --------------------------- + -- Analyze_Freeze_Entity -- + --------------------------- - CR_Pragma : Node_Id := Empty; - -- Points to N_Pragma node if Complete_Representation pragma present + procedure Analyze_Freeze_Entity (N : Node_Id) is + E : constant Entity_Id := Entity (N); begin - if Ignore_Rep_Clauses then - return; + -- Remember that we are processing a freezing entity. Required to + -- ensure correct decoration of internal entities associated with + -- interfaces (see New_Overloaded_Entity). + + Inside_Freezing_Actions := Inside_Freezing_Actions + 1; + + -- For tagged types covering interfaces add internal entities that link + -- the primitives of the interfaces with the primitives that cover them. + -- Note: These entities were originally generated only when generating + -- code because their main purpose was to provide support to initialize + -- the secondary dispatch tables. They are now generated also when + -- compiling with no code generation to provide ASIS the relationship + -- between interface primitives and tagged type primitives. They are + -- also used to locate primitives covering interfaces when processing + -- generics (see Derive_Subprograms). + + if Ada_Version >= Ada_05 + and then Ekind (E) = E_Record_Type + and then Is_Tagged_Type (E) + and then not Is_Interface (E) + and then Has_Interfaces (E) + then + -- This would be a good common place to call the routine that checks + -- overriding of interface primitives (and thus factorize calls to + -- Check_Abstract_Overriding located at different contexts in the + -- compiler). However, this is not possible because it causes + -- spurious errors in case of late overriding. + + Add_Internal_Interface_Entities (E); end if; - Find_Type (Ident); - Rectype := Entity (Ident); + -- Check CPP types - if Rectype = Any_Type - or else Rep_Item_Too_Early (Rectype, N) + if Ekind (E) = E_Record_Type + and then Is_CPP_Class (E) + and then Is_Tagged_Type (E) + and then Tagged_Type_Expansion + and then Expander_Active then - return; - else - Rectype := Underlying_Type (Rectype); - end if; + if CPP_Num_Prims (E) = 0 then + + -- If the CPP type has user defined components then it must import + -- primitives from C++. This is required because if the C++ class + -- has no primitives then the C++ compiler does not added the _tag + -- component to the type. + + pragma Assert (Chars (First_Entity (E)) = Name_uTag); + + if First_Entity (E) /= Last_Entity (E) then + Error_Msg_N + ("?'C'P'P type must import at least one primitive from C++", + E); + end if; + end if; + + -- Check that all its primitives are abstract or imported from C++. + -- Check also availability of the C++ constructor. + + declare + Has_Constructors : constant Boolean := Has_CPP_Constructors (E); + Elmt : Elmt_Id; + Error_Reported : Boolean := False; + Prim : Node_Id; + + begin + Elmt := First_Elmt (Primitive_Operations (E)); + while Present (Elmt) loop + Prim := Node (Elmt); + + if Comes_From_Source (Prim) then + if Is_Abstract_Subprogram (Prim) then + null; + + elsif not Is_Imported (Prim) + or else Convention (Prim) /= Convention_CPP + then + Error_Msg_N + ("?primitives of 'C'P'P types must be imported from C++" + & " or abstract", Prim); + + elsif not Has_Constructors + and then not Error_Reported + then + Error_Msg_Name_1 := Chars (E); + Error_Msg_N + ("?'C'P'P constructor required for type %", Prim); + Error_Reported := True; + end if; + end if; + + Next_Elmt (Elmt); + end loop; + end; + end if; + + Inside_Freezing_Actions := Inside_Freezing_Actions - 1; + end Analyze_Freeze_Entity; + + ------------------------------------------ + -- Analyze_Record_Representation_Clause -- + ------------------------------------------ + + -- Note: we check as much as we can here, but we can't do any checks + -- based on the position values (e.g. overlap checks) until freeze time + -- because especially in Ada 2005 (machine scalar mode), the processing + -- for non-standard bit order can substantially change the positions. + -- See procedure Check_Record_Representation_Clause (called from Freeze) + -- for the remainder of this processing. + + procedure Analyze_Record_Representation_Clause (N : Node_Id) is + Ident : constant Node_Id := Identifier (N); + Biased : Boolean; + CC : Node_Id; + Comp : Entity_Id; + Fbit : Uint; + Hbit : Uint := Uint_0; + Lbit : Uint; + Ocomp : Entity_Id; + Posit : Uint; + Rectype : Entity_Id; + + CR_Pragma : Node_Id := Empty; + -- Points to N_Pragma node if Complete_Representation pragma present + + begin + if Ignore_Rep_Clauses then + return; + end if; + + 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 @@ -2260,10 +2535,6 @@ package body Sem_Ch13 is ("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; @@ -2330,7 +2601,6 @@ package body Sem_Ch13 is -- Get the alignment value to perform error checking Mod_Val := Get_Alignment_Value (Expression (M)); - end if; end; end if; @@ -2357,51 +2627,12 @@ package body Sem_Ch13 is 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). - - Fent := First_Entity (Rectype); - - 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 @@ -2420,7 +2651,6 @@ package body Sem_Ch13 is -- 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)); @@ -2480,6 +2710,24 @@ package body Sem_Ch13 is Error_Msg_N ("component clause is for non-existent field", CC); + -- Ada 2012 (AI05-0026): Any name that denotes a + -- discriminant of an object of an unchecked union type + -- shall not occur within a record_representation_clause. + + -- The general restriction of using record rep clauses on + -- Unchecked_Union types has now been lifted. Since it is + -- possible to introduce a record rep clause which mentions + -- the discriminant of an Unchecked_Union in non-Ada 2012 + -- code, this check is applied to all versions of the + -- language. + + elsif Ekind (Comp) = E_Discriminant + and then Is_Unchecked_Union (Rectype) + then + Error_Msg_N + ("cannot reference discriminant of Unchecked_Union", + Component_Name (CC)); + elsif Present (Component_Clause (Comp)) then -- Diagnose duplicate rep clause, or check consistency @@ -2513,6 +2761,9 @@ package body Sem_Ch13 is end; end if; + -- Normal case where this is the first component clause we + -- have seen for this entity, so set it up properly. + else -- Make reference for field in record rep clause and set -- appropriate entity field in the field identifier. @@ -2526,12 +2777,6 @@ package body Sem_Ch13 is 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 @@ -2545,15 +2790,13 @@ package body Sem_Ch13 is 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 + if Warn_On_Overridden_Size + and then Has_Size_Clause (Etype (Comp)) + and then RM_Size (Etype (Comp)) /= Esize (Comp) then Error_Msg_NE - ("component overlaps tag field of&", - CC, Rectype); + ("?component size overrides size clause for&", + Component_Name (CC), Etype (Comp)); end if; -- This information is also set in the corresponding @@ -2572,13 +2815,8 @@ package body Sem_Ch13 is Esize (Comp), Biased); - Set_Has_Biased_Representation (Comp, Biased); - - if Biased and Warn_On_Biased_Representation then - Error_Msg_F - ("?component clause forces biased " - & "representation", CC); - end if; + Set_Biased + (Comp, First_Node (CC), "component clause", Biased); if Present (Ocomp) then Set_Component_Clause (Ocomp, CC); @@ -2590,6 +2828,10 @@ package body Sem_Ch13 is Set_Normalized_Position_Max (Ocomp, Normalized_Position (Ocomp)); + -- Note: we don't use Set_Biased here, because we + -- already gave a warning above if needed, and we + -- would get a duplicate for the same name here. + Set_Has_Biased_Representation (Ocomp, Has_Biased_Representation (Comp)); end if; @@ -2606,378 +2848,95 @@ package body Sem_Ch13 is 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 + -- Check missing components if Complete_Representation pragma appeared - 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. + if Present (CR_Pragma) then + Comp := First_Component_Or_Discriminant (Rectype); + while Present (Comp) loop + if No (Component_Clause (Comp)) then + Error_Msg_NE + ("missing component clause for &", CR_Pragma, Comp); + end if; - 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. + Next_Component_Or_Discriminant (Comp); + end loop; - OC_Count : Natural := 0; - -- Count of entries in OC_Fbit and OC_Lbit + -- If no Complete_Representation pragma, warn if missing components - function OC_Lt (Op1, Op2 : Natural) return Boolean; - -- Compare routine for Sort + elsif Warn_On_Unrepped_Components then + declare + Num_Repped_Components : Nat := 0; + Num_Unrepped_Components : Nat := 0; - procedure OC_Move (From : Natural; To : Natural); - -- Move routine for Sort + begin + -- First count number of repped and unrepped components - package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt); + Comp := First_Component_Or_Discriminant (Rectype); + while Present (Comp) loop + if Present (Component_Clause (Comp)) then + Num_Repped_Components := Num_Repped_Components + 1; + else + Num_Unrepped_Components := Num_Unrepped_Components + 1; + end if; - function OC_Lt (Op1, Op2 : Natural) return Boolean is - begin - return OC_Fbit (Op1) < OC_Fbit (Op2); - end OC_Lt; + Next_Component_Or_Discriminant (Comp); + end loop; - procedure OC_Move (From : Natural; To : Natural) is - begin - OC_Fbit (To) := OC_Fbit (From); - OC_Lbit (To) := OC_Lbit (From); - end OC_Move; + -- We are only interested in the case where there is at least one + -- unrepped component, and at least half the components have rep + -- clauses. We figure that if less than half have them, then the + -- partial rep clause is really intentional. If the component + -- type has no underlying type set at this point (as for a generic + -- formal type), we don't know enough to give a warning on the + -- component. - 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 + if Num_Unrepped_Components > 0 + and then Num_Unrepped_Components < Num_Repped_Components + then + Comp := First_Component_Or_Discriminant (Rectype); + while Present (Comp) loop + if No (Component_Clause (Comp)) + and then Comes_From_Source (Comp) + and then Present (Underlying_Type (Etype (Comp))) + and then (Is_Scalar_Type (Underlying_Type (Etype (Comp))) + or else Size_Known_At_Compile_Time + (Underlying_Type (Etype (Comp)))) + and then not Has_Warnings_Off (Rectype) then - OC_Count := OC_Count + 1; - Posit := Posit * SSU; - OC_Fbit (OC_Count) := Fbit + Posit; - OC_Lbit (OC_Count) := Lbit + Posit; + Error_Msg_Sloc := Sloc (Comp); + Error_Msg_NE + ("?no component clause given for & declared #", + N, Comp); end if; - end if; - - Next (CC); - end loop; - Sorting.Sort (OC_Count); - - 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; + Next_Component_Or_Discriminant (Comp); + end loop; + end if; + end; end if; + end Analyze_Record_Representation_Clause; - -- 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 - -- different 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 + ----------------------------------- + -- Check_Constant_Address_Clause -- + ----------------------------------- - Clist : Node_Id; - -- Component_List node whose Component_Items are being checked + 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. - Citem : Node_Id; - -- Component declaration for component being checked + 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. - 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_In (Clist, N_Full_Type_Declaration, - 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 the parent of the component list is the - -- record definition, and its parent is the full type - -- declaration containing 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; - - <> - 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 appropriate 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 has no component clause - - Comp := First_Component_Or_Discriminant (Rectype); - while Present (Comp) loop - exit when No (Component_Clause (Comp)); - Next_Component_Or_Discriminant (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_Component_Or_Discriminant (Rectype); - while Present (Comp) loop - if No (Component_Clause (Comp)) then - Error_Msg_NE - ("missing component clause for &", CR_Pragma, Comp); - end if; - - Next_Component_Or_Discriminant (Comp); - end loop; - - -- If no Complete_Representation pragma, warn if missing components - - elsif Warn_On_Unrepped_Components then - declare - Num_Repped_Components : Nat := 0; - Num_Unrepped_Components : Nat := 0; - - begin - -- First count number of repped and unrepped components - - Comp := First_Component_Or_Discriminant (Rectype); - while Present (Comp) loop - if Present (Component_Clause (Comp)) then - Num_Repped_Components := Num_Repped_Components + 1; - else - Num_Unrepped_Components := Num_Unrepped_Components + 1; - end if; - - Next_Component_Or_Discriminant (Comp); - end loop; - - -- We are only interested in the case where there is at least one - -- unrepped component, and at least half the components have rep - -- clauses. We figure that if less than half have them, then the - -- partial rep clause is really intentional. If the component - -- type has no underlying type set at this point (as for a generic - -- formal type), we don't know enough to give a warning on the - -- component. - - if Num_Unrepped_Components > 0 - and then Num_Unrepped_Components < Num_Repped_Components - then - Comp := First_Component_Or_Discriminant (Rectype); - while Present (Comp) loop - if No (Component_Clause (Comp)) - and then Comes_From_Source (Comp) - and then Present (Underlying_Type (Etype (Comp))) - and then (Is_Scalar_Type (Underlying_Type (Etype (Comp))) - or else Size_Known_At_Compile_Time - (Underlying_Type (Etype (Comp)))) - and then not Has_Warnings_Off (Rectype) - then - Error_Msg_Sloc := Sloc (Comp); - Error_Msg_NE - ("?no component clause given for & declared #", - N, Comp); - end if; - - Next_Component_Or_Discriminant (Comp); - end loop; - end if; - end; - 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. + 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 -- @@ -3103,11 +3062,8 @@ package body Sem_Ch13 is -- 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) + if Ekind_In (Ent, E_Named_Integer, E_Named_Real) + or else Is_Type (Ent) then return; @@ -3229,82 +3185,833 @@ package body Sem_Ch13 is Check_Expr_Constants (Left_Opnd (Nod)); Check_Expr_Constants (Right_Opnd (Nod)); - when N_Unary_Op => - 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 (RM 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& (RM 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 + -- If rep_clauses are to be ignored, no need for legality checks. In + -- particular, no need to pester user about rep clauses that violate + -- the rule on constant addresses, given that these clauses will be + -- removed by Freeze before they reach the back end. + + if not Ignore_Rep_Clauses then + Check_Expr_Constants (Expr); + end if; + end Check_Constant_Address_Clause; + + ---------------------------------------- + -- Check_Record_Representation_Clause -- + ---------------------------------------- + + procedure Check_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; + Fbit : Uint; + Lbit : Uint; + Hbit : Uint := Uint_0; + Comp : Entity_Id; + Pcomp : Entity_Id; + + 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. + + Tagged_Parent : Entity_Id := Empty; + -- This is set in the case of a derived tagged type for which we have + -- Is_Fully_Repped_Tagged_Type True (indicating that all components are + -- positioned by record representation clauses). In this case we must + -- check for overlap between components of this tagged type, and the + -- components of its parent. Tagged_Parent will point to this parent + -- type. For all other cases Tagged_Parent is left set to Empty. + + Parent_Last_Bit : Uint; + -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the + -- last bit position for any field in the parent type. We only need to + -- check overlap for fields starting below this point. + + Overlap_Check_Required : Boolean; + -- Used to keep track of whether or not an overlap check is required + + Overlap_Detected : Boolean := False; + -- Set True if an overlap is detected + + Ccount : Natural := 0; + -- Number of component clauses in record rep clause + + procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id); + -- Given two entities for record components or discriminants, checks + -- if they have overlapping component clauses and issues errors if so. + + procedure Find_Component; + -- Finds component entity corresponding to current component clause (in + -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin + -- start/stop bits for the field. If there is no matching component or + -- if the matching component does not have a component clause, then + -- that's an error and Comp is set to Empty, but no error message is + -- issued, since the message was already given. Comp is also set to + -- Empty if the current "component clause" is in fact a pragma. + + ----------------------------- + -- Check_Component_Overlap -- + ----------------------------- + + procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is + CC1 : constant Node_Id := Component_Clause (C1_Ent); + CC2 : constant Node_Id := Component_Clause (C2_Ent); + + begin + if Present (CC1) and then Present (CC2) 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, perhaps on an error. + + 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 (CC2); + Error_Msg_Sloc := Sloc (Error_Msg_Node_2); + Error_Msg_Node_1 := Component_Name (CC1); + Error_Msg_N + ("component& overlaps & #", Component_Name (CC1)); + Overlap_Detected := True; + end if; + end; + end if; + end Check_Component_Overlap; + + -------------------- + -- Find_Component -- + -------------------- + + procedure Find_Component is + + procedure Search_Component (R : Entity_Id); + -- Search components of R for a match. If found, Comp is set. + + ---------------------- + -- Search_Component -- + ---------------------- + + procedure Search_Component (R : Entity_Id) is + begin + Comp := First_Component_Or_Discriminant (R); + while Present (Comp) loop + + -- Ignore error of attribute name for component name (we + -- already gave an error message for this, so no need to + -- complain here) + + if Nkind (Component_Name (CC)) = N_Attribute_Reference then + null; + else + exit when Chars (Comp) = Chars (Component_Name (CC)); + end if; + + Next_Component_Or_Discriminant (Comp); + end loop; + end Search_Component; + + -- Start of processing for Find_Component + + begin + -- Return with Comp set to Empty if we have a pragma + + if Nkind (CC) = N_Pragma then + Comp := Empty; + return; + end if; + + -- Search current record for matching component + + Search_Component (Rectype); + + -- If not found, maybe component of base type that is absent from + -- statically constrained first subtype. + + if No (Comp) then + Search_Component (Base_Type (Rectype)); + end if; + + -- If no component, or the component does not reference the component + -- clause in question, then there was some previous error for which + -- we already gave a message, so just return with Comp Empty. + + if No (Comp) + or else Component_Clause (Comp) /= CC + then + Comp := Empty; + + -- Normal case where we have a component clause + + else + Fbit := Component_Bit_Offset (Comp); + Lbit := Fbit + Esize (Comp) - 1; + end if; + end Find_Component; + + -- Start of processing for Check_Record_Representation_Clause + + begin + Find_Type (Ident); + Rectype := Entity (Ident); + + if Rectype = Any_Type then + return; + else + Rectype := Underlying_Type (Rectype); + end if; + + -- See if we have a fully repped derived tagged type + + declare + PS : constant Entity_Id := Parent_Subtype (Rectype); + + begin + if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then + Tagged_Parent := PS; + + -- Find maximum bit of any component of the parent type + + Parent_Last_Bit := UI_From_Int (System_Address_Size - 1); + Pcomp := First_Entity (Tagged_Parent); + while Present (Pcomp) loop + if Ekind_In (Pcomp, E_Discriminant, E_Component) then + if Component_Bit_Offset (Pcomp) /= No_Uint + and then Known_Static_Esize (Pcomp) + then + Parent_Last_Bit := + UI_Max + (Parent_Last_Bit, + Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1); + end if; + + Next_Entity (Pcomp); + end if; + end loop; + end if; + end; + + -- 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). + + Fent := First_Entity (Rectype); + + 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; + + Max_Bit_So_Far := Uint_Minus_1; + Overlap_Check_Required := False; + + -- Process the component clauses + + while Present (CC) loop + Find_Component; + + if Present (Comp) then + Ccount := Ccount + 1; + + -- We need a full overlap check if record positions non-monotonic + + if Fbit <= Max_Bit_So_Far then + Overlap_Check_Required := True; + end if; + + Max_Bit_So_Far := Lbit; + + -- Check bit position out of range of specified size + + 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)); + + -- Check for overlap with tag field + + else + if Is_Tagged_Type (Rectype) + and then Fbit < System_Address_Size + then + Error_Msg_NE + ("component overlaps tag field of&", + Component_Name (CC), Rectype); + Overlap_Detected := True; + end if; + + if Hbit < Lbit then + Hbit := Lbit; + end if; + end if; + + -- Check parent overlap if component might overlap parent field + + if Present (Tagged_Parent) + and then Fbit <= Parent_Last_Bit + then + Pcomp := First_Component_Or_Discriminant (Tagged_Parent); + while Present (Pcomp) loop + if not Is_Tag (Pcomp) + and then Chars (Pcomp) /= Name_uParent + then + Check_Component_Overlap (Comp, Pcomp); + end if; + + Next_Component_Or_Discriminant (Pcomp); + end loop; + 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 + + procedure OC_Move (From : Natural; To : Natural); + -- Move routine for Sort + + package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt); + + ----------- + -- OC_Lt -- + ----------- + + function OC_Lt (Op1, Op2 : Natural) return Boolean is + begin + return OC_Fbit (Op1) < OC_Fbit (Op2); + end OC_Lt; + + ------------- + -- OC_Move -- + ------------- + + procedure OC_Move (From : Natural; To : Natural) is + begin + OC_Fbit (To) := OC_Fbit (From); + OC_Lbit (To) := OC_Lbit (From); + end OC_Move; + + -- Start of processing for Overlap_Check + + begin + CC := First (Component_Clauses (N)); + while Present (CC) loop + + -- Exclude component clause already marked in error + + if not Error_Posted (CC) then + Find_Component; + + if Present (Comp) then + OC_Count := OC_Count + 1; + OC_Fbit (OC_Count) := Fbit; + OC_Lbit (OC_Count) := Lbit; + end if; + end if; + + Next (CC); + end loop; + + Sorting.Sort (OC_Count); + + 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 + -- different 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 not Ekind_In (C1_Ent, E_Component, 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. + -- Possibly 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_In (Clist, N_Full_Type_Declaration, + 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 the parent of the component + -- list is the record definition, and its parent is the + -- full type declaration containing 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; + + <> + Next_Entity (C1_Ent); + + end loop Main_Component_Loop; + end Overlap_Check2; + end if; + + -- The following circuit deals with warning on record holes (gaps). We + -- skip this check if overlap was detected, since it makes sense for the + -- programmer to fix this illegality before worrying about warnings. + + if not Overlap_Detected and Warn_On_Record_Holes then + Record_Hole_Check : declare + Decl : constant Node_Id := Declaration_Node (Base_Type (Rectype)); + -- Full declaration of record type + + procedure Check_Component_List + (CL : Node_Id; + Sbit : Uint; + DS : List_Id); + -- Check component list CL for holes. The starting bit should be + -- Sbit. which is zero for the main record component list and set + -- appropriately for recursive calls for variants. DS is set to + -- a list of discriminant specifications to be included in the + -- consideration of components. It is No_List if none to consider. + + -------------------------- + -- Check_Component_List -- + -------------------------- + + procedure Check_Component_List + (CL : Node_Id; + Sbit : Uint; + DS : List_Id) + is + Compl : Integer; + + begin + Compl := Integer (List_Length (Component_Items (CL))); + + if DS /= No_List then + Compl := Compl + Integer (List_Length (DS)); + end if; + + declare + Comps : array (Natural range 0 .. Compl) of Entity_Id; + -- Gather components (zero entry is for sort routine) + + Ncomps : Natural := 0; + -- Number of entries stored in Comps (starting at Comps (1)) + + Citem : Node_Id; + -- One component item or discriminant specification + + Nbit : Uint; + -- Starting bit for next component + + CEnt : Entity_Id; + -- Component entity + + Variant : Node_Id; + -- One variant + + function Lt (Op1, Op2 : Natural) return Boolean; + -- Compare routine for Sort + + procedure Move (From : Natural; To : Natural); + -- Move routine for Sort + + package Sorting is new GNAT.Heap_Sort_G (Move, Lt); + + -------- + -- Lt -- + -------- + + function Lt (Op1, Op2 : Natural) return Boolean is + begin + return Component_Bit_Offset (Comps (Op1)) + < + Component_Bit_Offset (Comps (Op2)); + end Lt; + + ---------- + -- Move -- + ---------- + + procedure Move (From : Natural; To : Natural) is + begin + Comps (To) := Comps (From); + end Move; + + begin + -- Gather discriminants into Comp + + if DS /= No_List then + Citem := First (DS); + while Present (Citem) loop + if Nkind (Citem) = N_Discriminant_Specification then + declare + Ent : constant Entity_Id := + Defining_Identifier (Citem); + begin + if Ekind (Ent) = E_Discriminant then + Ncomps := Ncomps + 1; + Comps (Ncomps) := Ent; + end if; + end; + end if; + + Next (Citem); + end loop; + end if; + + -- Gather component entities into Comp + + Citem := First (Component_Items (CL)); + while Present (Citem) loop + if Nkind (Citem) = N_Component_Declaration then + Ncomps := Ncomps + 1; + Comps (Ncomps) := Defining_Identifier (Citem); + end if; + + Next (Citem); + end loop; + + -- Now sort the component entities based on the first bit. + -- Note we already know there are no overlapping components. + + Sorting.Sort (Ncomps); + + -- Loop through entries checking for holes + + Nbit := Sbit; + for J in 1 .. Ncomps loop + CEnt := Comps (J); + Error_Msg_Uint_1 := Component_Bit_Offset (CEnt) - Nbit; - when N_Type_Conversion | - N_Qualified_Expression | - N_Allocator => - Check_Expr_Constants (Expression (Nod)); + if Error_Msg_Uint_1 > 0 then + Error_Msg_NE + ("?^-bit gap before component&", + Component_Name (Component_Clause (CEnt)), CEnt); + end if; - when N_Unchecked_Type_Conversion => - Check_Expr_Constants (Expression (Nod)); + Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt); + end loop; - -- 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. + -- Process variant parts recursively if present - 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; + if Present (Variant_Part (CL)) then + Variant := First (Variants (Variant_Part (CL))); + while Present (Variant) loop + Check_Component_List + (Component_List (Variant), Nbit, No_List); + Next (Variant); + end loop; + end if; + end; + end Check_Component_List; - when N_Function_Call => - if not Is_Pure (Entity (Name (Nod))) then - Error_Msg_NE - ("invalid address clause for initialized object &!", - Nod, U_Ent); + -- Start of processing for Record_Hole_Check - Error_Msg_NE - ("\function & is not pure (RM 13.1(22))!", - Nod, Entity (Name (Nod))); + begin + declare + Sbit : Uint; + begin + if Is_Tagged_Type (Rectype) then + Sbit := UI_From_Int (System_Address_Size); else - Check_List_Constants (Parameter_Associations (Nod)); + Sbit := Uint_0; end if; - when N_Parameter_Association => - Check_Expr_Constants (Explicit_Actual_Parameter (Nod)); + if Nkind (Decl) = N_Full_Type_Declaration + and then Nkind (Type_Definition (Decl)) = N_Record_Definition + then + Check_Component_List + (Component_List (Type_Definition (Decl)), + Sbit, + Discriminant_Specifications (Decl)); + end if; + end; + end Record_Hole_Check; + end if; - when others => - Error_Msg_NE - ("invalid address clause for initialized object &!", - Nod, U_Ent); - Error_Msg_NE - ("\must be constant defined before& (RM 13.1(22))!", - Nod, U_Ent); - end case; - end Check_Expr_Constants; + -- 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. - -------------------------- - -- Check_List_Constants -- - -------------------------- + -- 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. - procedure Check_List_Constants (Lst : List_Id) is - Nod1 : Node_Id; + -- 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 appropriate to round up the size + -- to some convenient boundary, based on alignment considerations, etc). - 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; + if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then - -- Start of processing for Check_Constant_Address_Clause + -- Nothing to do if at least one component has no component clause - begin - Check_Expr_Constants (Expr); - end Check_Constant_Address_Clause; + Comp := First_Component_Or_Discriminant (Rectype); + while Present (Comp) loop + exit when No (Component_Clause (Comp)); + Next_Component_Or_Discriminant (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; + end Check_Record_Representation_Clause; ---------------- -- Check_Size -- @@ -3466,6 +4173,8 @@ package body Sem_Ch13 is procedure Initialize is begin + Address_Clause_Checks.Init; + Independence_Checks.Init; Unchecked_Conversions.Init; end Initialize; @@ -3779,9 +4488,10 @@ package body Sem_Ch13 is Out_Present => Out_P, Parameter_Type => T_Ref)); - Spec := Make_Procedure_Specification (Loc, - Defining_Unit_Name => Subp_Id, - Parameter_Specifications => Formals); + Spec := + Make_Procedure_Specification (Loc, + Defining_Unit_Name => Subp_Id, + Parameter_Specifications => Formals); end if; return Spec; @@ -3855,8 +4565,7 @@ package body Sem_Ch13 is elsif Is_Type (T) and then Is_Generic_Type (Root_Type (T)) then - Error_Msg_N - ("representation item not allowed for generic type", N); + Error_Msg_N ("representation item not allowed for generic type", N); return True; end if; @@ -4156,7 +4865,6 @@ package body Sem_Ch13 is -- cases were already dealt with. elsif Is_Enumeration_Type (T1) then - Enumeration_Case : declare L1, L2 : Entity_Id; @@ -4184,6 +4892,27 @@ package body Sem_Ch13 is end if; end Same_Representation; + ---------------- + -- Set_Biased -- + ---------------- + + procedure Set_Biased + (E : Entity_Id; + N : Node_Id; + Msg : String; + Biased : Boolean := True) + is + begin + if Biased then + Set_Has_Biased_Representation (E); + + if Warn_On_Biased_Representation then + Error_Msg_NE + ("?" & Msg & " forces biased representation for&", N, E); + end if; + end if; + end Set_Biased; + -------------------- -- Set_Enum_Esize -- -------------------- @@ -4255,6 +4984,8 @@ package body Sem_Ch13 is ACCR : Address_Clause_Check_Record renames Address_Clause_Checks.Table (J); + Expr : Node_Id; + X_Alignment : Uint; Y_Alignment : Uint; @@ -4266,35 +4997,17 @@ package body Sem_Ch13 is if not Address_Warning_Posted (ACCR.N) then - -- Get alignments. Really we should always have the alignment - -- of the objects properly back annotated, but right now the - -- back end fails to back annotate for address clauses??? + Expr := Original_Node (Expression (ACCR.N)); - if Known_Alignment (ACCR.X) then - X_Alignment := Alignment (ACCR.X); - else - X_Alignment := Alignment (Etype (ACCR.X)); - end if; + -- Get alignments - if Known_Alignment (ACCR.Y) then - Y_Alignment := Alignment (ACCR.Y); - else - Y_Alignment := Alignment (Etype (ACCR.Y)); - end if; + X_Alignment := Alignment (ACCR.X); + Y_Alignment := Alignment (ACCR.Y); -- Similarly obtain sizes - if Known_Esize (ACCR.X) then - X_Size := Esize (ACCR.X); - else - X_Size := Esize (Etype (ACCR.X)); - end if; - - if Known_Esize (ACCR.Y) then - Y_Size := Esize (ACCR.Y); - else - Y_Size := Esize (Etype (ACCR.Y)); - end if; + X_Size := Esize (ACCR.X); + Y_Size := Esize (ACCR.Y); -- Check for large object overlaying smaller one @@ -4302,8 +5015,10 @@ package body Sem_Ch13 is and then X_Size > Uint_0 and then X_Size > Y_Size then + Error_Msg_NE + ("?& overlays smaller object", ACCR.N, ACCR.X); Error_Msg_N - ("?size for overlaid object is too small", ACCR.N); + ("\?program execution may be erroneous", ACCR.N); Error_Msg_Uint_1 := X_Size; Error_Msg_NE ("\?size of & is ^", ACCR.N, ACCR.X); @@ -4311,16 +5026,23 @@ package body Sem_Ch13 is Error_Msg_NE ("\?size of & is ^", ACCR.N, ACCR.Y); - -- Check for inadequate alignment. Again the defensive check - -- on Y_Alignment should not be needed, but because of the - -- failure in back end annotation, we can have an alignment - -- of 0 here??? + -- Check for inadequate alignment, both of the base object + -- and of the offset, if any. - -- Note: we do not check alignments if we gave a size - -- warning, since it would likely be redundant. + -- Note: we do not check the alignment if we gave a size + -- warning, since it would likely be redundant. elsif Y_Alignment /= Uint_0 - and then Y_Alignment < X_Alignment + and then (Y_Alignment < X_Alignment + or else (ACCR.Off + and then + Nkind (Expr) = N_Attribute_Reference + and then + Attribute_Name (Expr) = Name_Address + and then + Has_Compatible_Alignment + (ACCR.X, Prefix (Expr)) + /= Known_Compatible)) then Error_Msg_NE ("?specified address for& may be inconsistent " @@ -4337,12 +5059,303 @@ package body Sem_Ch13 is Error_Msg_NE ("\?alignment of & is ^", ACCR.N, ACCR.Y); + if Y_Alignment >= X_Alignment then + Error_Msg_N + ("\?but offset is not multiple of alignment", + ACCR.N); + end if; end if; end if; end; end loop; end Validate_Address_Clauses; + --------------------------- + -- Validate_Independence -- + --------------------------- + + procedure Validate_Independence is + SU : constant Uint := UI_From_Int (System_Storage_Unit); + N : Node_Id; + E : Entity_Id; + IC : Boolean; + Comp : Entity_Id; + Addr : Node_Id; + P : Node_Id; + + procedure Check_Array_Type (Atyp : Entity_Id); + -- Checks if the array type Atyp has independent components, and + -- if not, outputs an appropriate set of error messages. + + procedure No_Independence; + -- Output message that independence cannot be guaranteed + + function OK_Component (C : Entity_Id) return Boolean; + -- Checks one component to see if it is independently accessible, and + -- if so yields True, otherwise yields False if independent access + -- cannot be guaranteed. This is a conservative routine, it only + -- returns True if it knows for sure, it returns False if it knows + -- there is a problem, or it cannot be sure there is no problem. + + procedure Reason_Bad_Component (C : Entity_Id); + -- Outputs continuation message if a reason can be determined for + -- the component C being bad. + + ---------------------- + -- Check_Array_Type -- + ---------------------- + + procedure Check_Array_Type (Atyp : Entity_Id) is + Ctyp : constant Entity_Id := Component_Type (Atyp); + + begin + -- OK if no alignment clause, no pack, and no component size + + if not Has_Component_Size_Clause (Atyp) + and then not Has_Alignment_Clause (Atyp) + and then not Is_Packed (Atyp) + then + return; + end if; + + -- Check actual component size + + if not Known_Component_Size (Atyp) + or else not (Addressable (Component_Size (Atyp)) + and then Component_Size (Atyp) < 64) + or else Component_Size (Atyp) mod Esize (Ctyp) /= 0 + then + No_Independence; + + -- Bad component size, check reason + + if Has_Component_Size_Clause (Atyp) then + P := + Get_Attribute_Definition_Clause + (Atyp, Attribute_Component_Size); + + if Present (P) then + Error_Msg_Sloc := Sloc (P); + Error_Msg_N ("\because of Component_Size clause#", N); + return; + end if; + end if; + + if Is_Packed (Atyp) then + P := Get_Rep_Pragma (Atyp, Name_Pack); + + if Present (P) then + Error_Msg_Sloc := Sloc (P); + Error_Msg_N ("\because of pragma Pack#", N); + return; + end if; + end if; + + -- No reason found, just return + + return; + end if; + + -- Array type is OK independence-wise + + return; + end Check_Array_Type; + + --------------------- + -- No_Independence -- + --------------------- + + procedure No_Independence is + begin + if Pragma_Name (N) = Name_Independent then + Error_Msg_NE + ("independence cannot be guaranteed for&", N, E); + else + Error_Msg_NE + ("independent components cannot be guaranteed for&", N, E); + end if; + end No_Independence; + + ------------------ + -- OK_Component -- + ------------------ + + function OK_Component (C : Entity_Id) return Boolean is + Rec : constant Entity_Id := Scope (C); + Ctyp : constant Entity_Id := Etype (C); + + begin + -- OK if no component clause, no Pack, and no alignment clause + + if No (Component_Clause (C)) + and then not Is_Packed (Rec) + and then not Has_Alignment_Clause (Rec) + then + return True; + end if; + + -- Here we look at the actual component layout. A component is + -- addressable if its size is a multiple of the Esize of the + -- component type, and its starting position in the record has + -- appropriate alignment, and the record itself has appropriate + -- alignment to guarantee the component alignment. + + -- Make sure sizes are static, always assume the worst for any + -- cases where we cannot check static values. + + if not (Known_Static_Esize (C) + and then Known_Static_Esize (Ctyp)) + then + return False; + end if; + + -- Size of component must be addressable or greater than 64 bits + -- and a multiple of bytes. + + if not Addressable (Esize (C)) + and then Esize (C) < Uint_64 + then + return False; + end if; + + -- Check size is proper multiple + + if Esize (C) mod Esize (Ctyp) /= 0 then + return False; + end if; + + -- Check alignment of component is OK + + if not Known_Component_Bit_Offset (C) + or else Component_Bit_Offset (C) < Uint_0 + or else Component_Bit_Offset (C) mod Esize (Ctyp) /= 0 + then + return False; + end if; + + -- Check alignment of record type is OK + + if not Known_Alignment (Rec) + or else (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0 + then + return False; + end if; + + -- All tests passed, component is addressable + + return True; + end OK_Component; + + -------------------------- + -- Reason_Bad_Component -- + -------------------------- + + procedure Reason_Bad_Component (C : Entity_Id) is + Rec : constant Entity_Id := Scope (C); + Ctyp : constant Entity_Id := Etype (C); + + begin + -- If component clause present assume that's the problem + + if Present (Component_Clause (C)) then + Error_Msg_Sloc := Sloc (Component_Clause (C)); + Error_Msg_N ("\because of Component_Clause#", N); + return; + end if; + + -- If pragma Pack clause present, assume that's the problem + + if Is_Packed (Rec) then + P := Get_Rep_Pragma (Rec, Name_Pack); + + if Present (P) then + Error_Msg_Sloc := Sloc (P); + Error_Msg_N ("\because of pragma Pack#", N); + return; + end if; + end if; + + -- See if record has bad alignment clause + + if Has_Alignment_Clause (Rec) + and then Known_Alignment (Rec) + and then (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0 + then + P := Get_Attribute_Definition_Clause (Rec, Attribute_Alignment); + + if Present (P) then + Error_Msg_Sloc := Sloc (P); + Error_Msg_N ("\because of Alignment clause#", N); + end if; + end if; + + -- Couldn't find a reason, so return without a message + + return; + end Reason_Bad_Component; + + -- Start of processing for Validate_Independence + + begin + for J in Independence_Checks.First .. Independence_Checks.Last loop + N := Independence_Checks.Table (J).N; + E := Independence_Checks.Table (J).E; + IC := Pragma_Name (N) = Name_Independent_Components; + + -- Deal with component case + + if Ekind (E) = E_Discriminant or else Ekind (E) = E_Component then + if not OK_Component (E) then + No_Independence; + Reason_Bad_Component (E); + goto Continue; + end if; + end if; + + -- Deal with record with Independent_Components + + if IC and then Is_Record_Type (E) then + Comp := First_Component_Or_Discriminant (E); + while Present (Comp) loop + if not OK_Component (Comp) then + No_Independence; + Reason_Bad_Component (Comp); + goto Continue; + end if; + + Next_Component_Or_Discriminant (Comp); + end loop; + end if; + + -- Deal with address clause case + + if Is_Object (E) then + Addr := Address_Clause (E); + + if Present (Addr) then + No_Independence; + Error_Msg_Sloc := Sloc (Addr); + Error_Msg_N ("\because of Address clause#", N); + goto Continue; + end if; + end if; + + -- Deal with independent components for array type + + if IC and then Is_Array_Type (E) then + Check_Array_Type (E); + end if; + + -- Deal with independent components for array object + + if IC and then Is_Object (E) and then Is_Array_Type (Etype (E)) then + Check_Array_Type (Etype (E)); + end if; + + <> null; + end loop; + end Validate_Independence; + ----------------------------------- -- Validate_Unchecked_Conversion -- -----------------------------------