-- --
-- 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- --
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;
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;
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;
-- 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
-- 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;
-- 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 --
----------------------------------------------
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 (
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;
--------------------------------------
-- 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 |
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;
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);
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);
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);
-- 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
-- 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
-- Alignment attribute definition clause
- when Attribute_Alignment => Alignment_Block : declare
+ when Attribute_Alignment => Alignment : declare
Align : constant Uint := Get_Alignment_Value (Expr);
begin
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 --
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;
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
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);
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;
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);
("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
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
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);
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 :=
Defining_Identifier => Pool,
Subtype_Mark =>
New_Occurrence_Of (Etype (Expr), Loc),
- Name => Expr);
+ Name => Expr);
begin
Insert_Before (N, Rnode);
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;
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);
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);
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
Err := True;
end if;
- Set_Enumeration_Rep_Expr (Elit, Choice);
+ Set_Enumeration_Rep_Expr (Elit, Expression (Assoc));
Expr := Expression (Assoc);
Val := Static_Integer (Expr);
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));
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;
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
("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;
-- Get the alignment value to perform error checking
Mod_Val := Get_Alignment_Value (Expression (M));
-
end if;
end;
end if;
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
-- 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));
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
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.
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
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
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);
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;
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;
-
- <<Continue_Main_Component_Loop>>
- Next_Entity (C1_Ent);
-
- end loop Main_Component_Loop;
- end Overlap_Check2;
- end if;
-
- -- For records that have component clauses for all components, and whose
- -- size is less than or equal to 32, we need to know the size in the
- -- front end to activate possible packed array processing where the
- -- component type is a record.
-
- -- At this stage Hbit + 1 represents the first unused bit from all the
- -- component clauses processed, so if the component clauses are
- -- complete, then this is the length of the record.
-
- -- For records longer than System.Storage_Unit, and for those where not
- -- all components have component clauses, the back end determines the
- -- length (it may for example be 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 --
-- 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;
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;
+
+ <<Continue_Main_Component_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 --
procedure Initialize is
begin
+ Address_Clause_Checks.Init;
+ Independence_Checks.Init;
Unchecked_Conversions.Init;
end Initialize;
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;
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;
-- cases were already dealt with.
elsif Is_Enumeration_Type (T1) then
-
Enumeration_Case : declare
L1, L2 : Entity_Id;
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 --
--------------------
ACCR : Address_Clause_Check_Record
renames Address_Clause_Checks.Table (J);
+ Expr : Node_Id;
+
X_Alignment : Uint;
Y_Alignment : Uint;
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
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);
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 "
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;
+
+ <<Continue>> null;
+ end loop;
+ end Validate_Independence;
+
-----------------------------------
-- Validate_Unchecked_Conversion --
-----------------------------------
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