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------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ C H 1 3 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2012, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Aspects; use Aspects; 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 Lib.Xref; use Lib.Xref; with Namet; use Namet; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Restrict; use Restrict; with Rident; use Rident; with Rtsfind; use Rtsfind; with Sem; use Sem; with Sem_Aux; use Sem_Aux; with Sem_Ch3; use Sem_Ch3; with Sem_Ch6; use Sem_Ch6; with Sem_Ch8; use Sem_Ch8; with Sem_Dim; use Sem_Dim; with Sem_Eval; use Sem_Eval; with Sem_Res; use Sem_Res; with Sem_Type; use Sem_Type; with Sem_Util; use Sem_Util; with Sem_Warn; use Sem_Warn; with Sinput; use Sinput; with Snames; use Snames; with Stand; use Stand; with Sinfo; use Sinfo; with Stringt; use Stringt; with Targparm; use Targparm; with Ttypes; use Ttypes; with Tbuild; use Tbuild; with Urealp; use Urealp; with Warnsw; use Warnsw; with GNAT.Heap_Sort_G; package body Sem_Ch13 is SSU : constant Pos := System_Storage_Unit; -- Convenient short hand for commonly used constant ----------------------- -- Local Subprograms -- ----------------------- procedure Alignment_Check_For_Size_Change (Typ : Entity_Id; Size : Uint); -- This routine is called after setting one of the sizes of type entity -- Typ to Size. The purpose is to deal with the situation of a derived -- type whose inherited alignment is no longer appropriate for the new -- size value. In this case, we reset the Alignment to unknown. procedure Build_Predicate_Function (Typ : Entity_Id; N : Node_Id); -- If Typ has predicates (indicated by Has_Predicates being set for Typ, -- then either there are pragma Invariant entries on the rep chain for the -- type (note that Predicate aspects are converted to pragma Predicate), or -- there are inherited aspects from a parent type, or ancestor subtypes. -- This procedure builds the spec and body for the Predicate function that -- tests these predicates. N is the freeze node for the type. The spec of -- the function is inserted before the freeze node, and the body of the -- function is inserted after the freeze node. procedure Build_Static_Predicate (Typ : Entity_Id; Expr : Node_Id; Nam : Name_Id); -- Given a predicated type Typ, where Typ is a discrete static subtype, -- whose predicate expression is Expr, tests if Expr is a static predicate, -- and if so, builds the predicate range list. Nam is the name of the one -- argument to the predicate function. Occurrences of the type name in the -- predicate expression have been replaced by identifier references to this -- name, which is unique, so any identifier with Chars matching Nam must be -- a reference to the type. If the predicate is non-static, this procedure -- returns doing nothing. If the predicate is static, then the predicate -- list is stored in Static_Predicate (Typ), and the Expr is rewritten as -- a canonicalized membership operation. function Get_Alignment_Value (Expr : Node_Id) return Uint; -- Given the expression for an alignment value, returns the corresponding -- Uint value. If the value is inappropriate, then error messages are -- posted as required, and a value of No_Uint is returned. function Is_Operational_Item (N : Node_Id) return Boolean; -- A specification for a stream attribute is allowed before the full type -- is declared, as explained in AI-00137 and the corrigendum. Attributes -- that do not specify a representation characteristic are operational -- attributes. procedure New_Stream_Subprogram (N : Node_Id; Ent : Entity_Id; Subp : Entity_Id; Nam : TSS_Name_Type); -- Create a subprogram renaming of a given stream attribute to the -- designated subprogram and then in the tagged case, provide this as a -- primitive operation, or in the non-tagged case make an appropriate TSS -- entry. This is more properly an expansion activity than just semantics, -- but the presence of user-defined stream functions for limited types is a -- legality check, which is why this takes place here rather than in -- exp_ch13, where it was previously. Nam indicates the name of the TSS -- function to be generated. -- -- To avoid elaboration anomalies with freeze nodes, for untagged types -- we generate both a subprogram declaration and a subprogram renaming -- declaration, so that the attribute specification is handled as a -- renaming_as_body. For tagged types, the specification is one of the -- primitive specs. generic with procedure Replace_Type_Reference (N : Node_Id); procedure Replace_Type_References_Generic (N : Node_Id; TName : Name_Id); -- This is used to scan an expression for a predicate or invariant aspect -- replacing occurrences of the name TName (the name of the subtype to -- which the aspect applies) with appropriate references to the parameter -- of the predicate function or invariant procedure. The procedure passed -- as a generic parameter does the actual replacement of node N, which is -- either a simple direct reference to TName, or a selected component that -- represents an appropriately qualified occurrence of TName. 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 -- ---------------------------------------------- -- The following table collects unchecked conversions for validation. -- Entries are made by Validate_Unchecked_Conversion and then the call -- to Validate_Unchecked_Conversions does the actual error checking and -- posting of warnings. The reason for this delayed processing is to take -- advantage of back-annotations of size and alignment values performed by -- the back end. -- Note: the reason we store a Source_Ptr value instead of a Node_Id is -- that by the time Validate_Unchecked_Conversions is called, Sprint will -- already have modified all Sloc values if the -gnatD option is set. type UC_Entry is record Eloc : Source_Ptr; -- node used for posting warnings Source : Entity_Id; -- source type for unchecked conversion Target : Entity_Id; -- target type for unchecked conversion end record; package Unchecked_Conversions is new Table.Table ( Table_Component_Type => UC_Entry, Table_Index_Type => Int, Table_Low_Bound => 1, Table_Initial => 50, Table_Increment => 200, Table_Name => "Unchecked_Conversions"); ---------------------------------------- -- Table for Validate_Address_Clauses -- ---------------------------------------- -- If an address clause has the form -- for X'Address use Expr -- where Expr is of the form Y'Address or recursively is a reference to a -- constant of either of these forms, and X and Y are entities of objects, -- then if Y has a smaller alignment than X, that merits a warning about -- possible bad alignment. The following table collects address clauses of -- this kind. We put these in a table so that they can be checked after the -- back end has completed annotation of the alignments of objects, since we -- can catch more cases that way. type Address_Clause_Check_Record is record N : Node_Id; -- The address clause X : Entity_Id; -- The entity of the object overlaying Y Y : Entity_Id; -- The entity of the object being overlaid Off : Boolean; -- Whether the address is offset within Y end record; package Address_Clause_Checks is new Table.Table ( Table_Component_Type => Address_Clause_Check_Record, Table_Index_Type => Int, Table_Low_Bound => 1, Table_Initial => 20, Table_Increment => 200, Table_Name => "Address_Clause_Checks"); ----------------------------------------- -- Adjust_Record_For_Reverse_Bit_Order -- ----------------------------------------- procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is Comp : Node_Id; CC : Node_Id; begin -- Processing depends on version of Ada -- For Ada 95, we just renumber bits within a storage unit. We do the -- same for Ada 83 mode, since we recognize the Bit_Order attribute in -- Ada 83, and are free to add this extension. if Ada_Version < Ada_2005 then Comp := First_Component_Or_Discriminant (R); while Present (Comp) loop CC := Component_Clause (Comp); -- If component clause is present, then deal with the non-default -- bit order case for Ada 95 mode. -- 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 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); Storage_Unit_Offset : constant Uint := CFB / System_Storage_Unit; Start_Bit : constant Uint := CFB mod System_Storage_Unit; begin -- Cases where field goes over storage unit boundary if Start_Bit + CSZ > System_Storage_Unit then -- Allow multi-byte field but generate warning 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?", CLC); if Bytes_Big_Endian then Error_Msg_N ("bytes are not reversed " & "(component is big-endian)?", CLC); else Error_Msg_N ("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 field fits in one storage unit else -- 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; Next_Component_Or_Discriminant (Comp); end loop; -- 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. 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); if Present (CC) then declare Fbit : constant Uint := Static_Integer (First_Bit (CC)); Lbit : constant Uint := Static_Integer (Last_Bit (CC)); begin -- Case of component with last bit >= max machine scalar if Lbit >= Max_Machine_Scalar_Size then -- This is allowed only if first bit is zero, and -- last bit + 1 is a multiple of storage unit size. if Fbit = 0 and then (Lbit + 1) mod SSU = 0 then -- This is the case to give a warning if enabled if Warn_On_Reverse_Bit_Order then Error_Msg_N ("multi-byte field specified with " & " non-standard Bit_Order?", CC); 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; -- Give error message for RM 13.4.1(10) violation else Error_Msg_FE ("machine scalar rules not followed for&", First_Bit (CC), Comp); Error_Msg_Uint_1 := Lbit; Error_Msg_Uint_2 := Max_Machine_Scalar_Size; Error_Msg_F ("\last bit (^) exceeds maximum machine " & "scalar size (^)", First_Bit (CC)); if (Lbit + 1) mod SSU /= 0 then Error_Msg_Uint_1 := SSU; Error_Msg_F ("\and is not a multiple of Storage_Unit (^) " & "(RM 13.4.1(10))", First_Bit (CC)); else Error_Msg_Uint_1 := Fbit; Error_Msg_F ("\and first bit (^) is non-zero " & "(RM 13.4.1(10))", First_Bit (CC)); end if; end if; -- OK case of machine scalar related component clause, -- For now, just count them. else Num_CC := Num_CC + 1; end if; end; end if; 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. 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. function CP_Lt (Op1, Op2 : Natural) return Boolean; -- Compare routine for Sort procedure CP_Move (From : Natural; To : Natural); -- Move routine for Sort package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt); 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). MaxL : Uint; -- Maximum last bit value of any component in this set MSS : Uint; -- Corresponding machine scalar size ----------- -- CP_Lt -- ----------- function CP_Lt (Op1, Op2 : Natural) return Boolean is begin return Position (Component_Clause (Comps (Op1))) < Position (Component_Clause (Comps (Op2))); end CP_Lt; ------------- -- 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 machine scalar relevant component clauses Num_CC := 0; Comp := First_Component_Or_Discriminant (R); while Present (Comp) loop declare CC : constant Node_Id := Component_Clause (Comp); begin -- Collect only component clauses whose last bit is less -- than machine scalar size. Any component clause whose -- last bit exceeds this value does not take part in -- machine scalar layout considerations. The test for -- Error_Posted makes sure we exclude component clauses -- for which we already posted an error. if Present (CC) and then not Error_Posted (Last_Bit (CC)) and then Static_Integer (Last_Bit (CC)) < Max_Machine_Scalar_Size then Num_CC := Num_CC + 1; Comps (Num_CC) := Comp; end if; end; 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 exit; end if; 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 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; ------------------------------------- -- Alignment_Check_For_Size_Change -- ------------------------------------- procedure Alignment_Check_For_Size_Change (Typ : Entity_Id; Size : Uint) is begin -- If the alignment is known, and not set by a rep clause, and is -- inconsistent with the size being set, then reset it to unknown, -- we assume in this case that the size overrides the inherited -- alignment, and that the alignment must be recomputed. if Known_Alignment (Typ) and then not Has_Alignment_Clause (Typ) and then Size mod (Alignment (Typ) * SSU) /= 0 then Init_Alignment (Typ); end if; end Alignment_Check_For_Size_Change; ----------------------------------- -- Analyze_Aspect_Specifications -- ----------------------------------- procedure Analyze_Aspect_Specifications (N : Node_Id; E : Entity_Id) is Aspect : Node_Id; Aitem : Node_Id; Ent : Node_Id; L : constant List_Id := Aspect_Specifications (N); Ins_Node : Node_Id := N; -- Insert pragmas (except Pre/Post/Invariant/Predicate) after this node -- The general processing involves building an attribute definition -- clause or a pragma node that corresponds to the aspect. Then one -- of two things happens: -- If we are required to delay the evaluation of this aspect to the -- freeze point, we attach the corresponding pragma/attribute definition -- clause to the aspect specification node, which is then placed in the -- Rep Item chain. In this case we mark the entity by setting the flag -- Has_Delayed_Aspects and we evaluate the rep item at the freeze point. -- If no delay is required, we just insert the pragma or attribute -- after the declaration, and it will get processed by the normal -- circuit. The From_Aspect_Specification flag is set on the pragma -- or attribute definition node in either case to activate special -- processing (e.g. not traversing the list of homonyms for inline). Delay_Required : Boolean := False; -- Set True if delay is required begin pragma Assert (Present (L)); -- Loop through aspects Aspect := First (L); Aspect_Loop : while Present (Aspect) loop declare Loc : constant Source_Ptr := Sloc (Aspect); Id : constant Node_Id := Identifier (Aspect); Expr : constant Node_Id := Expression (Aspect); Nam : constant Name_Id := Chars (Id); A_Id : constant Aspect_Id := Get_Aspect_Id (Nam); Anod : Node_Id; Eloc : Source_Ptr := No_Location; -- Source location of expression, modified when we split PPC's. It -- is set below when Expr is present. procedure Check_False_Aspect_For_Derived_Type; -- This procedure checks for the case of a false aspect for a -- derived type, which improperly tries to cancel an aspect -- inherited from the parent; ----------------------------------------- -- Check_False_Aspect_For_Derived_Type -- ----------------------------------------- procedure Check_False_Aspect_For_Derived_Type is begin -- We are only checking derived types if not Is_Derived_Type (E) then return; end if; case A_Id is when Aspect_Atomic | Aspect_Shared => if not Is_Atomic (E) then return; end if; when Aspect_Atomic_Components => if not Has_Atomic_Components (E) then return; end if; when Aspect_Discard_Names => if not Discard_Names (E) then return; end if; when Aspect_Pack => if not Is_Packed (E) then return; end if; when Aspect_Unchecked_Union => if not Is_Unchecked_Union (E) then return; end if; when Aspect_Volatile => if not Is_Volatile (E) then return; end if; when Aspect_Volatile_Components => if not Has_Volatile_Components (E) then return; end if; when others => return; end case; -- Fall through means we are canceling an inherited aspect Error_Msg_Name_1 := Nam; Error_Msg_NE ("derived type& inherits aspect%, cannot cancel", Expr, E); end Check_False_Aspect_For_Derived_Type; -- Start of processing for Aspect_Loop begin -- Skip aspect if already analyzed (not clear if this is needed) if Analyzed (Aspect) then goto Continue; end if; -- Set the source location of expression, used in the case of -- a failed precondition/postcondition or invariant. Note that -- the source location of the expression is not usually the best -- choice here. For example, it gets located on the last AND -- keyword in a chain of boolean expressiond AND'ed together. -- It is best to put the message on the first character of the -- assertion, which is the effect of the First_Node call here. if Present (Expr) then Eloc := Sloc (First_Node (Expr)); end if; -- Check restriction No_Implementation_Aspect_Specifications if Impl_Defined_Aspects (A_Id) then Check_Restriction (No_Implementation_Aspect_Specifications, Aspect); end if; -- Check restriction No_Specification_Of_Aspect Check_Restriction_No_Specification_Of_Aspect (Aspect); -- Analyze this aspect Set_Analyzed (Aspect); Set_Entity (Aspect, E); Ent := New_Occurrence_Of (E, Sloc (Id)); -- Check for duplicate aspect. Note that the Comes_From_Source -- test allows duplicate Pre/Post's that we generate internally -- to escape being flagged here. if No_Duplicates_Allowed (A_Id) then Anod := First (L); while Anod /= Aspect loop if Same_Aspect (A_Id, Get_Aspect_Id (Chars (Identifier (Anod)))) and then Comes_From_Source (Aspect) then Error_Msg_Name_1 := Nam; Error_Msg_Sloc := Sloc (Anod); -- Case of same aspect specified twice if Class_Present (Anod) = Class_Present (Aspect) then if not Class_Present (Anod) then Error_Msg_NE ("aspect% for & previously given#", Id, E); else Error_Msg_NE ("aspect `%''Class` for & previously given#", Id, E); end if; -- Case of Pre and Pre'Class both specified elsif Nam = Name_Pre then if Class_Present (Aspect) then Error_Msg_NE ("aspect `Pre''Class` for & is not allowed here", Id, E); Error_Msg_NE ("\since aspect `Pre` previously given#", Id, E); else Error_Msg_NE ("aspect `Pre` for & is not allowed here", Id, E); Error_Msg_NE ("\since aspect `Pre''Class` previously given#", Id, E); end if; end if; -- Allowed case of X and X'Class both specified end if; Next (Anod); end loop; end if; -- Check some general restrictions on language defined aspects if not Impl_Defined_Aspects (A_Id) then Error_Msg_Name_1 := Nam; -- Not allowed for renaming declarations if Nkind (N) in N_Renaming_Declaration then Error_Msg_N ("aspect % not allowed for renaming declaration", Aspect); end if; -- Not allowed for formal type declarations if Nkind (N) = N_Formal_Type_Declaration then Error_Msg_N ("aspect % not allowed for formal type declaration", Aspect); end if; end if; -- Copy expression for later processing by the procedures -- Check_Aspect_At_[Freeze_Point | End_Of_Declarations] Set_Entity (Id, New_Copy_Tree (Expr)); -- Processing based on specific aspect case A_Id is -- No_Aspect should be impossible when No_Aspect => raise Program_Error; -- Aspects taking an optional boolean argument. For all of -- these we just create a matching pragma and insert it, if -- the expression is missing or set to True. If the expression -- is False, we can ignore the aspect with the exception that -- in the case of a derived type, we must check for an illegal -- attempt to cancel an inherited aspect. when Boolean_Aspects => Set_Is_Boolean_Aspect (Aspect); if Present (Expr) and then Is_False (Static_Boolean (Expr)) then Check_False_Aspect_For_Derived_Type; goto Continue; end if; -- If True, build corresponding pragma node Aitem := Make_Pragma (Loc, Pragma_Argument_Associations => New_List (Ent), Pragma_Identifier => Make_Identifier (Sloc (Id), Chars (Id))); -- Never need to delay for boolean aspects pragma Assert (not Delay_Required); -- Library unit aspects. These are boolean aspects, but we -- have to do special things with the insertion, since the -- pragma belongs inside the declarations of a package. when Library_Unit_Aspects => if Present (Expr) and then Is_False (Static_Boolean (Expr)) then goto Continue; end if; -- Build corresponding pragma node Aitem := Make_Pragma (Loc, Pragma_Argument_Associations => New_List (Ent), Pragma_Identifier => Make_Identifier (Sloc (Id), Chars (Id))); -- This requires special handling in the case of a package -- declaration, the pragma needs to be inserted in the list -- of declarations for the associated package. There is no -- issue of visibility delay for these aspects. if Nkind (N) = N_Package_Declaration then if Nkind (Parent (N)) /= N_Compilation_Unit then Error_Msg_N ("incorrect context for library unit aspect&", Id); else Prepend (Aitem, Visible_Declarations (Specification (N))); end if; goto Continue; end if; -- If not package declaration, no delay is required pragma Assert (not Delay_Required); -- Aspects related to container iterators. These aspects denote -- subprograms, and thus must be delayed. when Aspect_Constant_Indexing | Aspect_Variable_Indexing => if not Is_Type (E) or else not Is_Tagged_Type (E) then Error_Msg_N ("indexing applies to a tagged type", N); end if; Aitem := Make_Attribute_Definition_Clause (Loc, Name => Ent, Chars => Chars (Id), Expression => Relocate_Node (Expr)); Delay_Required := True; Set_Is_Delayed_Aspect (Aspect); when Aspect_Default_Iterator | Aspect_Iterator_Element => Aitem := Make_Attribute_Definition_Clause (Loc, Name => Ent, Chars => Chars (Id), Expression => Relocate_Node (Expr)); Delay_Required := True; Set_Is_Delayed_Aspect (Aspect); when Aspect_Implicit_Dereference => if not Is_Type (E) or else not Has_Discriminants (E) then Error_Msg_N ("Aspect must apply to a type with discriminants", N); goto Continue; else declare Disc : Entity_Id; begin Disc := First_Discriminant (E); while Present (Disc) loop if Chars (Expr) = Chars (Disc) and then Ekind (Etype (Disc)) = E_Anonymous_Access_Type then Set_Has_Implicit_Dereference (E); Set_Has_Implicit_Dereference (Disc); goto Continue; end if; Next_Discriminant (Disc); end loop; -- Error if no proper access discriminant. Error_Msg_NE ("not an access discriminant of&", Expr, E); end; goto Continue; end if; -- Aspects corresponding to attribute definition clauses when Aspect_Address | Aspect_Alignment | Aspect_Bit_Order | Aspect_Component_Size | Aspect_External_Tag | Aspect_Input | Aspect_Machine_Radix | Aspect_Object_Size | Aspect_Output | Aspect_Read | Aspect_Size | Aspect_Small | Aspect_Simple_Storage_Pool | Aspect_Storage_Pool | Aspect_Storage_Size | Aspect_Stream_Size | Aspect_Value_Size | Aspect_Write => -- Construct the attribute definition clause Aitem := Make_Attribute_Definition_Clause (Loc, Name => Ent, Chars => Chars (Id), Expression => Relocate_Node (Expr)); -- A delay is required except in the common case where -- the expression is a literal, in which case it is fine -- to take care of it right away. if Nkind_In (Expr, N_Integer_Literal, N_String_Literal) then pragma Assert (not Delay_Required); null; else Delay_Required := True; Set_Is_Delayed_Aspect (Aspect); end if; -- Aspects corresponding to pragmas with two arguments, where -- the first argument is a local name referring to the entity, -- and the second argument is the aspect definition expression -- which is an expression that does not get analyzed. when Aspect_Suppress | Aspect_Unsuppress => -- Construct the pragma Aitem := Make_Pragma (Loc, Pragma_Argument_Associations => New_List ( New_Occurrence_Of (E, Loc), Relocate_Node (Expr)), Pragma_Identifier => Make_Identifier (Sloc (Id), Chars (Id))); -- We don't have to play the delay game here, since the only -- values are check names which don't get analyzed anyway. pragma Assert (not Delay_Required); when Aspect_Synchronization => -- The aspect corresponds to pragma Implemented. -- Construct the pragma Aitem := Make_Pragma (Loc, Pragma_Argument_Associations => New_List ( New_Occurrence_Of (E, Loc), Relocate_Node (Expr)), Pragma_Identifier => Make_Identifier (Sloc (Id), Name_Implemented)); pragma Assert (not Delay_Required); -- Aspects corresponding to pragmas with two arguments, where -- the second argument is a local name referring to the entity, -- and the first argument is the aspect definition expression. when Aspect_Warnings => -- Construct the pragma Aitem := Make_Pragma (Loc, Pragma_Argument_Associations => New_List ( Relocate_Node (Expr), New_Occurrence_Of (E, Loc)), Pragma_Identifier => Make_Identifier (Sloc (Id), Chars (Id)), Class_Present => Class_Present (Aspect)); -- We don't have to play the delay game here, since the only -- values are ON/OFF which don't get analyzed anyway. pragma Assert (not Delay_Required); -- Default_Value and Default_Component_Value aspects. These -- are specially handled because they have no corresponding -- pragmas or attributes. when Aspect_Default_Value | Aspect_Default_Component_Value => Error_Msg_Name_1 := Chars (Id); if not Is_Type (E) then Error_Msg_N ("aspect% can only apply to a type", Id); goto Continue; elsif not Is_First_Subtype (E) then Error_Msg_N ("aspect% cannot apply to subtype", Id); goto Continue; elsif A_Id = Aspect_Default_Value and then not Is_Scalar_Type (E) then Error_Msg_N ("aspect% can only be applied to scalar type", Id); goto Continue; elsif A_Id = Aspect_Default_Component_Value then if not Is_Array_Type (E) then Error_Msg_N ("aspect% can only be applied to array type", Id); goto Continue; elsif not Is_Scalar_Type (Component_Type (E)) then Error_Msg_N ("aspect% requires scalar components", Id); goto Continue; end if; end if; Aitem := Empty; Delay_Required := True; Set_Is_Delayed_Aspect (Aspect); Set_Has_Default_Aspect (Base_Type (Entity (Ent))); if Is_Scalar_Type (E) then Set_Default_Aspect_Value (Entity (Ent), Expr); else Set_Default_Aspect_Component_Value (Entity (Ent), Expr); end if; when Aspect_Attach_Handler => Aitem := Make_Pragma (Loc, Pragma_Identifier => Make_Identifier (Sloc (Id), Name_Attach_Handler), Pragma_Argument_Associations => New_List (Ent, Relocate_Node (Expr))); Set_From_Aspect_Specification (Aitem, True); Set_Corresponding_Aspect (Aitem, Aspect); pragma Assert (not Delay_Required); when Aspect_Priority | Aspect_Interrupt_Priority | Aspect_Dispatching_Domain | Aspect_CPU => declare Pname : Name_Id; begin if A_Id = Aspect_Priority then Pname := Name_Priority; elsif A_Id = Aspect_Interrupt_Priority then Pname := Name_Interrupt_Priority; elsif A_Id = Aspect_CPU then Pname := Name_CPU; else Pname := Name_Dispatching_Domain; end if; Aitem := Make_Pragma (Loc, Pragma_Identifier => Make_Identifier (Sloc (Id), Pname), Pragma_Argument_Associations => New_List (Make_Pragma_Argument_Association (Sloc => Sloc (Id), Expression => Relocate_Node (Expr)))); Set_From_Aspect_Specification (Aitem, True); Set_Corresponding_Aspect (Aitem, Aspect); pragma Assert (not Delay_Required); end; -- Aspects Pre/Post generate Precondition/Postcondition pragmas -- with a first argument that is the expression, and a second -- argument that is an informative message if the test fails. -- This is inserted right after the declaration, to get the -- required pragma placement. The processing for the pragmas -- takes care of the required delay. when Pre_Post_Aspects => declare Pname : Name_Id; begin if A_Id = Aspect_Pre or else A_Id = Aspect_Precondition then Pname := Name_Precondition; else Pname := Name_Postcondition; end if; -- If the expressions is of the form A and then B, then -- we generate separate Pre/Post aspects for the separate -- clauses. Since we allow multiple pragmas, there is no -- problem in allowing multiple Pre/Post aspects internally. -- These should be treated in reverse order (B first and -- A second) since they are later inserted just after N in -- the order they are treated. This way, the pragma for A -- ends up preceding the pragma for B, which may have an -- importance for the error raised (either constraint error -- or precondition error). -- We do not do this for Pre'Class, since we have to put -- these conditions together in a complex OR expression -- We do not do this in ASIS mode, as ASIS relies on the -- original node representing the complete expression, when -- retrieving it through the source aspect table. if not ASIS_Mode and then (Pname = Name_Postcondition or else not Class_Present (Aspect)) then while Nkind (Expr) = N_And_Then loop Insert_After (Aspect, Make_Aspect_Specification (Sloc (Left_Opnd (Expr)), Identifier => Identifier (Aspect), Expression => Relocate_Node (Left_Opnd (Expr)), Class_Present => Class_Present (Aspect), Split_PPC => True)); Rewrite (Expr, Relocate_Node (Right_Opnd (Expr))); Eloc := Sloc (Expr); end loop; end if; -- Build the precondition/postcondition pragma Aitem := Make_Pragma (Loc, Pragma_Identifier => Make_Identifier (Sloc (Id), Pname), Class_Present => Class_Present (Aspect), Split_PPC => Split_PPC (Aspect), Pragma_Argument_Associations => New_List ( Make_Pragma_Argument_Association (Eloc, Chars => Name_Check, Expression => Relocate_Node (Expr)))); -- Add message unless exception messages are suppressed if not Opt.Exception_Locations_Suppressed then Append_To (Pragma_Argument_Associations (Aitem), Make_Pragma_Argument_Association (Eloc, Chars => Name_Message, Expression => Make_String_Literal (Eloc, Strval => "failed " & Get_Name_String (Pname) & " from " & Build_Location_String (Eloc)))); end if; Set_From_Aspect_Specification (Aitem, True); Set_Corresponding_Aspect (Aitem, Aspect); Set_Is_Delayed_Aspect (Aspect); -- For Pre/Post cases, insert immediately after the entity -- declaration, since that is the required pragma placement. -- Note that for these aspects, we do not have to worry -- about delay issues, since the pragmas themselves deal -- with delay of visibility for the expression analysis. -- If the entity is a library-level subprogram, the pre/ -- postconditions must be treated as late pragmas. if Nkind (Parent (N)) = N_Compilation_Unit then Add_Global_Declaration (Aitem); else Insert_After (N, Aitem); end if; goto Continue; end; -- Invariant aspects generate a corresponding pragma with a -- first argument that is the entity, a second argument that is -- the expression and a third argument that is an appropriate -- message. This is inserted right after the declaration, to -- get the required pragma placement. The pragma processing -- takes care of the required delay. when Aspect_Invariant | Aspect_Type_Invariant => -- Analysis of the pragma will verify placement legality: -- an invariant must apply to a private type, or appear in -- the private part of a spec and apply to a completion. -- Construct the pragma Aitem := Make_Pragma (Loc, Pragma_Argument_Associations => New_List (Ent, Relocate_Node (Expr)), Class_Present => Class_Present (Aspect), Pragma_Identifier => Make_Identifier (Sloc (Id), Name_Invariant)); -- Add message unless exception messages are suppressed if not Opt.Exception_Locations_Suppressed then Append_To (Pragma_Argument_Associations (Aitem), Make_Pragma_Argument_Association (Eloc, Chars => Name_Message, Expression => Make_String_Literal (Eloc, Strval => "failed invariant from " & Build_Location_String (Eloc)))); end if; Set_From_Aspect_Specification (Aitem, True); Set_Corresponding_Aspect (Aitem, Aspect); Set_Is_Delayed_Aspect (Aspect); -- For Invariant case, insert immediately after the entity -- declaration. We do not have to worry about delay issues -- since the pragma processing takes care of this. Insert_After (N, Aitem); goto Continue; -- Predicate aspects generate a corresponding pragma with a -- first argument that is the entity, and the second argument -- is the expression. when Aspect_Dynamic_Predicate | Aspect_Predicate | Aspect_Static_Predicate => -- Construct the pragma (always a pragma Predicate, with -- flags recording whether it is static/dynamic). Aitem := Make_Pragma (Loc, Pragma_Argument_Associations => New_List (Ent, Relocate_Node (Expr)), Class_Present => Class_Present (Aspect), Pragma_Identifier => Make_Identifier (Sloc (Id), Name_Predicate)); Set_From_Aspect_Specification (Aitem, True); Set_Corresponding_Aspect (Aitem, Aspect); -- Make sure we have a freeze node (it might otherwise be -- missing in cases like subtype X is Y, and we would not -- have a place to build the predicate function). -- If the type is private, indicate that its completion -- has a freeze node, because that is the one that will be -- visible at freeze time. Set_Has_Predicates (E); if Is_Private_Type (E) and then Present (Full_View (E)) then Set_Has_Predicates (Full_View (E)); Set_Has_Delayed_Aspects (Full_View (E)); Ensure_Freeze_Node (Full_View (E)); end if; Ensure_Freeze_Node (E); Set_Is_Delayed_Aspect (Aspect); Delay_Required := True; when Aspect_Test_Case => declare Args : List_Id; Comp_Expr : Node_Id; Comp_Assn : Node_Id; New_Expr : Node_Id; begin Args := New_List; if Nkind (Parent (N)) = N_Compilation_Unit then Error_Msg_N ("incorrect placement of aspect `Test_Case`", E); goto Continue; end if; if Nkind (Expr) /= N_Aggregate then Error_Msg_NE ("wrong syntax for aspect `Test_Case` for &", Id, E); goto Continue; end if; -- Make pragma expressions refer to the original aspect -- expressions through the Original_Node link. This is used -- in semantic analysis for ASIS mode, so that the original -- expression also gets analyzed. Comp_Expr := First (Expressions (Expr)); while Present (Comp_Expr) loop New_Expr := Relocate_Node (Comp_Expr); Set_Original_Node (New_Expr, Comp_Expr); Append (Make_Pragma_Argument_Association (Sloc (Comp_Expr), Expression => New_Expr), Args); Next (Comp_Expr); end loop; Comp_Assn := First (Component_Associations (Expr)); while Present (Comp_Assn) loop if List_Length (Choices (Comp_Assn)) /= 1 or else Nkind (First (Choices (Comp_Assn))) /= N_Identifier then Error_Msg_NE ("wrong syntax for aspect `Test_Case` for &", Id, E); goto Continue; end if; New_Expr := Relocate_Node (Expression (Comp_Assn)); Set_Original_Node (New_Expr, Expression (Comp_Assn)); Append (Make_Pragma_Argument_Association ( Sloc => Sloc (Comp_Assn), Chars => Chars (First (Choices (Comp_Assn))), Expression => New_Expr), Args); Next (Comp_Assn); end loop; -- Build the test-case pragma Aitem := Make_Pragma (Loc, Pragma_Identifier => Make_Identifier (Sloc (Id), Name_Test_Case), Pragma_Argument_Associations => Args); Set_From_Aspect_Specification (Aitem, True); Set_Corresponding_Aspect (Aitem, Aspect); Set_Is_Delayed_Aspect (Aspect); -- Insert immediately after the entity declaration Insert_After (N, Aitem); goto Continue; end; when Aspect_Dimension => Analyze_Aspect_Dimension (N, Id, Expr); goto Continue; when Aspect_Dimension_System => Analyze_Aspect_Dimension_System (N, Id, Expr); goto Continue; end case; -- If a delay is required, we delay the freeze (not much point in -- delaying the aspect if we don't delay the freeze!). The pragma -- or attribute clause if there is one is then attached to the -- aspect specification which is placed in the rep item list. if Delay_Required then if Present (Aitem) then Set_From_Aspect_Specification (Aitem, True); if Nkind (Aitem) = N_Pragma then Set_Corresponding_Aspect (Aitem, Aspect); end if; Set_Is_Delayed_Aspect (Aitem); Set_Aspect_Rep_Item (Aspect, Aitem); end if; Ensure_Freeze_Node (E); Set_Has_Delayed_Aspects (E); Record_Rep_Item (E, Aspect); -- If no delay required, insert the pragma/clause in the tree else Set_From_Aspect_Specification (Aitem, True); if Nkind (Aitem) = N_Pragma then Set_Corresponding_Aspect (Aitem, Aspect); end if; -- If this is a compilation unit, we will put the pragma in -- the Pragmas_After list of the N_Compilation_Unit_Aux node. if Nkind (Parent (Ins_Node)) = N_Compilation_Unit then declare Aux : constant Node_Id := Aux_Decls_Node (Parent (Ins_Node)); begin pragma Assert (Nkind (Aux) = N_Compilation_Unit_Aux); if No (Pragmas_After (Aux)) then Set_Pragmas_After (Aux, Empty_List); end if; -- For Pre_Post put at start of list, otherwise at end if A_Id in Pre_Post_Aspects then Prepend (Aitem, Pragmas_After (Aux)); else Append (Aitem, Pragmas_After (Aux)); end if; end; -- Here if not compilation unit case else case A_Id is -- For Pre/Post cases, insert immediately after the -- entity declaration, since that is the required pragma -- placement. when Pre_Post_Aspects => Insert_After (N, Aitem); -- For Priority aspects, insert into the task or -- protected definition, which we need to create if it's -- not there. The same applies to CPU and -- Dispatching_Domain but only to tasks. when Aspect_Priority | Aspect_Interrupt_Priority | Aspect_Dispatching_Domain | Aspect_CPU => declare T : Node_Id; -- the type declaration L : List_Id; -- list of decls of task/protected begin if Nkind (N) = N_Object_Declaration then T := Parent (Etype (Defining_Identifier (N))); else T := N; end if; if Nkind (T) = N_Protected_Type_Declaration and then A_Id /= Aspect_Dispatching_Domain and then A_Id /= Aspect_CPU then pragma Assert (Present (Protected_Definition (T))); L := Visible_Declarations (Protected_Definition (T)); elsif Nkind (T) = N_Task_Type_Declaration then if No (Task_Definition (T)) then Set_Task_Definition (T, Make_Task_Definition (Sloc (T), Visible_Declarations => New_List, End_Label => Empty)); end if; L := Visible_Declarations (Task_Definition (T)); else raise Program_Error; end if; Prepend (Aitem, To => L); -- Analyze rewritten pragma. Otherwise, its -- analysis is done too late, after the task or -- protected object has been created. Analyze (Aitem); end; -- For all other cases, insert in sequence when others => Insert_After (Ins_Node, Aitem); Ins_Node := Aitem; end case; end if; end if; end; <<Continue>> Next (Aspect); end loop Aspect_Loop; end Analyze_Aspect_Specifications; ----------------------- -- Analyze_At_Clause -- ----------------------- -- An at clause is replaced by the corresponding Address attribute -- definition clause that is the preferred approach in Ada 95. procedure Analyze_At_Clause (N : Node_Id) is CS : constant Boolean := Comes_From_Source (N); begin -- This is an obsolescent feature Check_Restriction (No_Obsolescent_Features, N); if Warn_On_Obsolescent_Feature then Error_Msg_N ("at clause is an obsolescent feature (RM J.7(2))?", N); Error_Msg_N ("\use address attribute definition clause instead?", N); end if; -- Rewrite as address clause Rewrite (N, Make_Attribute_Definition_Clause (Sloc (N), Name => Identifier (N), Chars => Name_Address, Expression => Expression (N))); -- We preserve Comes_From_Source, since logically the clause still -- comes from the source program even though it is changed in form. Set_Comes_From_Source (N, CS); -- Analyze rewritten clause Analyze_Attribute_Definition_Clause (N); end Analyze_At_Clause; ----------------------------------------- -- Analyze_Attribute_Definition_Clause -- ----------------------------------------- procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Nam : constant Node_Id := Name (N); Attr : constant Name_Id := Chars (N); Expr : constant Node_Id := Expression (N); Id : constant Attribute_Id := Get_Attribute_Id (Attr); Ent : Entity_Id; -- The entity of Nam after it is analyzed. In the case of an incomplete -- type, this is the underlying type. U_Ent : Entity_Id; -- The underlying entity to which the attribute applies. Generally this -- is the Underlying_Type of Ent, except in the case where the clause -- applies to full view of incomplete type or private type in which case -- U_Ent is just a copy of Ent. FOnly : Boolean := False; -- Reset to True for subtype specific attribute (Alignment, Size) -- and for stream attributes, i.e. those cases where in the call -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing -- rules are checked. Note that the case of stream attributes is not -- clear from the RM, but see AI95-00137. Also, the RM seems to -- disallow Storage_Size for derived task types, but that is also -- clearly unintentional. procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type); -- Common processing for 'Read, 'Write, 'Input and 'Output attribute -- definition clauses. function Duplicate_Clause return Boolean; -- This routine checks if the aspect for U_Ent being given by attribute -- definition clause N is for an aspect that has already been specified, -- and if so gives an error message. If there is a duplicate, True is -- returned, otherwise if there is no error, False is returned. procedure Check_Indexing_Functions; -- Check that the function in Constant_Indexing or Variable_Indexing -- attribute has the proper type structure. If the name is overloaded, -- check that all interpretations are legal. procedure Check_Iterator_Functions; -- Check that there is a single function in Default_Iterator attribute -- has the proper type structure. function Check_Primitive_Function (Subp : Entity_Id) return Boolean; -- Common legality check for the previous two ----------------------------------- -- Analyze_Stream_TSS_Definition -- ----------------------------------- procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is Subp : Entity_Id := Empty; I : Interp_Index; It : Interp; Pnam : Entity_Id; Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read); -- True for Read attribute, false for other attributes function Has_Good_Profile (Subp : Entity_Id) return Boolean; -- Return true if the entity is a subprogram with an appropriate -- profile for the attribute being defined. ---------------------- -- Has_Good_Profile -- ---------------------- function Has_Good_Profile (Subp : Entity_Id) return Boolean is F : Entity_Id; Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input); Expected_Ekind : constant array (Boolean) of Entity_Kind := (False => E_Procedure, True => E_Function); Typ : Entity_Id; begin if Ekind (Subp) /= Expected_Ekind (Is_Function) then return False; end if; F := First_Formal (Subp); if No (F) or else Ekind (Etype (F)) /= E_Anonymous_Access_Type or else Designated_Type (Etype (F)) /= Class_Wide_Type (RTE (RE_Root_Stream_Type)) then return False; end if; if not Is_Function then Next_Formal (F); declare Expected_Mode : constant array (Boolean) of Entity_Kind := (False => E_In_Parameter, True => E_Out_Parameter); begin if Parameter_Mode (F) /= Expected_Mode (Is_Read) then return False; end if; end; Typ := Etype (F); else Typ := Etype (Subp); end if; return Base_Type (Typ) = Base_Type (Ent) and then No (Next_Formal (F)); end Has_Good_Profile; -- Start of processing for Analyze_Stream_TSS_Definition begin FOnly := True; if not Is_Type (U_Ent) then Error_Msg_N ("local name must be a subtype", Nam); return; end if; Pnam := TSS (Base_Type (U_Ent), TSS_Nam); -- If Pnam is present, it can be either inherited from an ancestor -- type (in which case it is legal to redefine it for this type), or -- be a previous definition of the attribute for the same type (in -- which case it is illegal). -- In the first case, it will have been analyzed already, and we -- can check that its profile does not match the expected profile -- for a stream attribute of U_Ent. In the second case, either Pnam -- has been analyzed (and has the expected profile), or it has not -- been analyzed yet (case of a type that has not been frozen yet -- and for which the stream attribute has been set using Set_TSS). if Present (Pnam) and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam)) then Error_Msg_Sloc := Sloc (Pnam); Error_Msg_Name_1 := Attr; Error_Msg_N ("% attribute already defined #", Nam); return; end if; Analyze (Expr); if Is_Entity_Name (Expr) then if not Is_Overloaded (Expr) then if Has_Good_Profile (Entity (Expr)) then Subp := Entity (Expr); end if; else Get_First_Interp (Expr, I, It); while Present (It.Nam) loop if Has_Good_Profile (It.Nam) then Subp := It.Nam; exit; end if; Get_Next_Interp (I, It); end loop; end if; end if; if Present (Subp) then if Is_Abstract_Subprogram (Subp) then Error_Msg_N ("stream subprogram must not be abstract", Expr); return; end if; Set_Entity (Expr, Subp); Set_Etype (Expr, Etype (Subp)); New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam); else Error_Msg_Name_1 := Attr; Error_Msg_N ("incorrect expression for% attribute", Expr); end if; end Analyze_Stream_TSS_Definition; ------------------------------ -- Check_Indexing_Functions -- ------------------------------ procedure Check_Indexing_Functions is procedure Check_One_Function (Subp : Entity_Id); -- Check one possible interpretation ------------------------ -- Check_One_Function -- ------------------------ procedure Check_One_Function (Subp : Entity_Id) is Default_Element : constant Node_Id := Find_Aspect (Etype (First_Formal (Subp)), Aspect_Iterator_Element); begin if not Check_Primitive_Function (Subp) then Error_Msg_NE ("aspect Indexing requires a function that applies to type&", Subp, Ent); end if; -- An indexing function must return either the default element of -- the container, or a reference type. if Present (Default_Element) then Analyze (Default_Element); if Is_Entity_Name (Default_Element) and then Covers (Entity (Default_Element), Etype (Subp)) then return; end if; end if; -- Otherwise the return type must be a reference type. if not Has_Implicit_Dereference (Etype (Subp)) then Error_Msg_N ("function for indexing must return a reference type", Subp); end if; end Check_One_Function; -- Start of processing for Check_Indexing_Functions begin if In_Instance then return; end if; Analyze (Expr); if not Is_Overloaded (Expr) then Check_One_Function (Entity (Expr)); else declare I : Interp_Index; It : Interp; begin Get_First_Interp (Expr, I, It); while Present (It.Nam) loop -- Note that analysis will have added the interpretation -- that corresponds to the dereference. We only check the -- subprogram itself. if Is_Overloadable (It.Nam) then Check_One_Function (It.Nam); end if; Get_Next_Interp (I, It); end loop; end; end if; end Check_Indexing_Functions; ------------------------------ -- Check_Iterator_Functions -- ------------------------------ procedure Check_Iterator_Functions is Default : Entity_Id; function Valid_Default_Iterator (Subp : Entity_Id) return Boolean; -- Check one possible interpretation for validity ---------------------------- -- Valid_Default_Iterator -- ---------------------------- function Valid_Default_Iterator (Subp : Entity_Id) return Boolean is Formal : Entity_Id; begin if not Check_Primitive_Function (Subp) then return False; else Formal := First_Formal (Subp); end if; -- False if any subsequent formal has no default expression Formal := Next_Formal (Formal); while Present (Formal) loop if No (Expression (Parent (Formal))) then return False; end if; Next_Formal (Formal); end loop; -- True if all subsequent formals have default expressions return True; end Valid_Default_Iterator; -- Start of processing for Check_Iterator_Functions begin Analyze (Expr); if not Is_Entity_Name (Expr) then Error_Msg_N ("aspect Iterator must be a function name", Expr); end if; if not Is_Overloaded (Expr) then if not Check_Primitive_Function (Entity (Expr)) then Error_Msg_NE ("aspect Indexing requires a function that applies to type&", Entity (Expr), Ent); end if; if not Valid_Default_Iterator (Entity (Expr)) then Error_Msg_N ("improper function for default iterator", Expr); end if; else Default := Empty; declare I : Interp_Index; It : Interp; begin Get_First_Interp (Expr, I, It); while Present (It.Nam) loop if not Check_Primitive_Function (It.Nam) or else not Valid_Default_Iterator (It.Nam) then Remove_Interp (I); elsif Present (Default) then Error_Msg_N ("default iterator must be unique", Expr); else Default := It.Nam; end if; Get_Next_Interp (I, It); end loop; end; if Present (Default) then Set_Entity (Expr, Default); Set_Is_Overloaded (Expr, False); end if; end if; end Check_Iterator_Functions; ------------------------------- -- Check_Primitive_Function -- ------------------------------- function Check_Primitive_Function (Subp : Entity_Id) return Boolean is Ctrl : Entity_Id; begin if Ekind (Subp) /= E_Function then return False; end if; if No (First_Formal (Subp)) then return False; else Ctrl := Etype (First_Formal (Subp)); end if; if Ctrl = Ent or else Ctrl = Class_Wide_Type (Ent) or else (Ekind (Ctrl) = E_Anonymous_Access_Type and then (Designated_Type (Ctrl) = Ent or else Designated_Type (Ctrl) = Class_Wide_Type (Ent))) then null; else return False; end if; return True; end Check_Primitive_Function; ---------------------- -- Duplicate_Clause -- ---------------------- function Duplicate_Clause return Boolean is A : Node_Id; begin -- Nothing to do if this attribute definition clause comes from -- an aspect specification, since we could not be duplicating an -- explicit clause, and we dealt with the case of duplicated aspects -- in Analyze_Aspect_Specifications. if From_Aspect_Specification (N) then return False; end if; -- Otherwise current clause may duplicate previous clause or a -- previously given aspect specification for the same aspect. A := Get_Rep_Item_For_Entity (U_Ent, Chars (N)); if Present (A) then if Entity (A) = U_Ent then Error_Msg_Name_1 := Chars (N); Error_Msg_Sloc := Sloc (A); Error_Msg_NE ("aspect% for & previously given#", N, U_Ent); return True; end if; end if; return False; end Duplicate_Clause; -- Start of processing for Analyze_Attribute_Definition_Clause begin -- The following code is a defense against recursion. Not clear that -- this can happen legitimately, but perhaps some error situations -- can cause it, and we did see this recursion during testing. if Analyzed (N) then return; else Set_Analyzed (N, True); end if; -- Ignore some selected attributes in CodePeer mode since they are not -- relevant in this context. if CodePeer_Mode then case Id is -- Ignore Component_Size in CodePeer mode, to avoid changing the -- internal representation of types by implicitly packing them. when Attribute_Component_Size => Rewrite (N, Make_Null_Statement (Sloc (N))); return; when others => null; end case; end if; -- Process Ignore_Rep_Clauses option if Ignore_Rep_Clauses then case Id is -- The following should be ignored. They do not affect legality -- and may be target dependent. The basic idea of -gnatI is to -- ignore any rep clauses that may be target dependent but do not -- affect legality (except possibly to be rejected because they -- are incompatible with the compilation target). when Attribute_Alignment | Attribute_Bit_Order | Attribute_Component_Size | Attribute_Machine_Radix | Attribute_Object_Size | Attribute_Size | Attribute_Stream_Size | Attribute_Value_Size => Rewrite (N, Make_Null_Statement (Sloc (N))); return; -- Perhaps 'Small should not be ignored by Ignore_Rep_Clauses ??? when Attribute_Small => if Ignore_Rep_Clauses then Rewrite (N, Make_Null_Statement (Sloc (N))); return; end if; -- The following should not be ignored, because in the first place -- they are reasonably portable, and should not cause problems in -- compiling code from another target, and also they do affect -- legality, e.g. failing to provide a stream attribute for a -- type may make a program illegal. when Attribute_External_Tag | Attribute_Input | Attribute_Output | Attribute_Read | Attribute_Simple_Storage_Pool | Attribute_Storage_Pool | Attribute_Storage_Size | Attribute_Write => null; -- Other cases are errors ("attribute& cannot be set with -- definition clause"), which will be caught below. when others => null; end case; end if; Analyze (Nam); Ent := Entity (Nam); if Rep_Item_Too_Early (Ent, N) then return; end if; -- Rep clause applies to full view of incomplete type or private type if -- we have one (if not, this is a premature use of the type). However, -- certain semantic checks need to be done on the specified entity (i.e. -- the private view), so we save it in Ent. if Is_Private_Type (Ent) and then Is_Derived_Type (Ent) and then not Is_Tagged_Type (Ent) and then No (Full_View (Ent)) then -- If this is a private type whose completion is a derivation from -- another private type, there is no full view, and the attribute -- belongs to the type itself, not its underlying parent. U_Ent := Ent; elsif Ekind (Ent) = E_Incomplete_Type then -- The attribute applies to the full view, set the entity of the -- attribute definition accordingly. Ent := Underlying_Type (Ent); U_Ent := Ent; Set_Entity (Nam, Ent); else U_Ent := Underlying_Type (Ent); end if; -- Avoid cascaded error if Etype (Nam) = Any_Type then return; -- Must be declared in current scope elsif Scope (Ent) /= Current_Scope then Error_Msg_N ("entity must be declared in this scope", Nam); return; -- Must not be a source renaming (we do have some cases where the -- expander generates a renaming, and those cases are OK, in such -- cases any attribute applies to the renamed object as well). elsif Is_Object (Ent) and then Present (Renamed_Object (Ent)) then -- Case of renamed object from source, this is an error if Comes_From_Source (Renamed_Object (Ent)) then Get_Name_String (Chars (N)); Error_Msg_Strlen := Name_Len; Error_Msg_String (1 .. Name_Len) := Name_Buffer (1 .. Name_Len); Error_Msg_N ("~ clause not allowed for a renaming declaration " & "(RM 13.1(6))", Nam); return; -- For the case of a compiler generated renaming, the attribute -- definition clause applies to the renamed object created by the -- expander. The easiest general way to handle this is to create a -- copy of the attribute definition clause for this object. else Insert_Action (N, Make_Attribute_Definition_Clause (Loc, Name => New_Occurrence_Of (Entity (Renamed_Object (Ent)), Loc), Chars => Chars (N), Expression => Duplicate_Subexpr (Expression (N)))); end if; -- If no underlying entity, use entity itself, applies to some -- previously detected error cases ??? elsif No (U_Ent) then U_Ent := Ent; -- Cannot specify for a subtype (exception Object/Value_Size) elsif Is_Type (U_Ent) and then not Is_First_Subtype (U_Ent) and then Id /= Attribute_Object_Size and then Id /= Attribute_Value_Size and then not From_At_Mod (N) then Error_Msg_N ("cannot specify attribute for subtype", Nam); return; end if; Set_Entity (N, U_Ent); -- Switch on particular attribute case Id is ------------- -- Address -- ------------- -- Address attribute definition clause when Attribute_Address => Address : begin -- A little error check, catch for X'Address use X'Address; if Nkind (Nam) = N_Identifier and then Nkind (Expr) = N_Attribute_Reference and then Attribute_Name (Expr) = Name_Address and then Nkind (Prefix (Expr)) = N_Identifier and then Chars (Nam) = Chars (Prefix (Expr)) then Error_Msg_NE ("address for & is self-referencing", Prefix (Expr), Ent); return; end if; -- Not that special case, carry on with analysis of expression 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 Duplicate_Clause then null; -- Case of address clause for subprogram elsif Is_Subprogram (U_Ent) then if Has_Homonym (U_Ent) then Error_Msg_N ("address clause cannot be given " & "for overloaded subprogram", Nam); return; end if; -- For subprograms, all address clauses are permitted, and we -- mark the subprogram as having a deferred freeze so that Gigi -- will not elaborate it too soon. -- Above needs more comments, what is too soon about??? Set_Has_Delayed_Freeze (U_Ent); -- Case of address clause for entry elsif Ekind (U_Ent) = E_Entry then if Nkind (Parent (N)) = N_Task_Body then Error_Msg_N ("entry address must be specified in task spec", Nam); return; end if; -- For entries, we require a constant address Check_Constant_Address_Clause (Expr, U_Ent); -- Special checks for task types if Is_Task_Type (Scope (U_Ent)) and then Comes_From_Source (Scope (U_Ent)) then Error_Msg_N ("?entry address declared for entry in task type", N); Error_Msg_N ("\?only one task can be declared of this type", N); end if; -- Entry address clauses are obsolescent Check_Restriction (No_Obsolescent_Features, N); if Warn_On_Obsolescent_Feature then Error_Msg_N ("attaching interrupt to task entry is an " & "obsolescent feature (RM J.7.1)?", N); Error_Msg_N ("\use interrupt procedure instead?", N); end if; -- Case of an address clause for a controlled object which we -- consider to be erroneous. elsif Is_Controlled (Etype (U_Ent)) or else Has_Controlled_Component (Etype (U_Ent)) then Error_Msg_NE ("?controlled object& must not be overlaid", Nam, U_Ent); Error_Msg_N ("\?Program_Error will be raised at run time", Nam); Insert_Action (Declaration_Node (U_Ent), Make_Raise_Program_Error (Loc, Reason => PE_Overlaid_Controlled_Object)); return; -- Case of address clause for a (non-controlled) object elsif Ekind (U_Ent) = E_Variable or else Ekind (U_Ent) = E_Constant then declare Expr : constant Node_Id := Expression (N); O_Ent : Entity_Id; Off : Boolean; begin -- Exported variables cannot have an address clause, because -- this cancels the effect of the pragma Export. if Is_Exported (U_Ent) then Error_Msg_N ("cannot export object with address clause", Nam); return; end if; Find_Overlaid_Entity (N, O_Ent, Off); -- Overlaying controlled objects is erroneous 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); Error_Msg_N ("\?Program_Error will be raised at run time", Expr); Insert_Action (Declaration_Node (U_Ent), Make_Raise_Program_Error (Loc, Reason => PE_Overlaid_Controlled_Object)); return; elsif Present (O_Ent) and then Ekind (U_Ent) = E_Constant and then not Is_Constant_Object (O_Ent) then Error_Msg_N ("constant overlays a variable?", Expr); -- Imported variables can have an address clause, but then -- the import is pretty meaningless except to suppress -- initializations, so we do not need such variables to -- be statically allocated (and in fact it causes trouble -- if the address clause is a local value). elsif Is_Imported (U_Ent) then Set_Is_Statically_Allocated (U_Ent, False); end if; -- We mark a possible modification of a variable with an -- address clause, since it is likely aliasing is occurring. Note_Possible_Modification (Nam, Sure => False); -- 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. 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 (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 -- objects is deferred until the freeze point, because -- a subsequent pragma might indicate that the object is -- imported and thus not initialized. Set_Has_Delayed_Freeze (U_Ent); -- If an initialization call has been generated for this -- object, it needs to be deferred to after the freeze node -- we have just now added, otherwise GIGI will see a -- reference to the variable (as actual to the IP call) -- before its definition. declare Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N); begin if Present (Init_Call) then Remove (Init_Call); Append_Freeze_Action (U_Ent, Init_Call); end if; end; if Is_Exported (U_Ent) then Error_Msg_N ("& cannot be exported if an address clause is given", Nam); Error_Msg_N ("\define and export a variable " & "that holds its address instead", Nam); end if; -- Entity has delayed freeze, so we will generate an -- alignment check at the freeze point unless suppressed. if not Range_Checks_Suppressed (U_Ent) and then not Alignment_Checks_Suppressed (U_Ent) then Set_Check_Address_Alignment (N); end if; -- Kill the size check code, since we are not allocating -- the variable, it is somewhere else. Kill_Size_Check_Code (U_Ent); -- If the address clause is of the form: -- for Y'Address use X'Address -- or -- Const : constant Address := X'Address; -- ... -- for Y'Address use Const; -- 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 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 Is_Constant_Object (O_Ent) and then Ekind (U_Ent) = E_Variable then Set_Overlays_Constant (U_Ent); end if; end if; end; -- Not a valid entity for an address clause else Error_Msg_N ("address cannot be given for &", Nam); end if; end Address; --------------- -- Alignment -- --------------- -- Alignment attribute definition clause when Attribute_Alignment => Alignment : declare Align : constant Uint := Get_Alignment_Value (Expr); Max_Align : constant Uint := UI_From_Int (Maximum_Alignment); begin FOnly := True; if not Is_Type (U_Ent) and then Ekind (U_Ent) /= E_Variable and then Ekind (U_Ent) /= E_Constant then Error_Msg_N ("alignment cannot be given for &", Nam); elsif Duplicate_Clause then null; elsif Align /= No_Uint then Set_Has_Alignment_Clause (U_Ent); -- Tagged type case, check for attempt to set alignment to a -- value greater than Max_Align, and reset if so. if Is_Tagged_Type (U_Ent) and then Align > Max_Align then Error_Msg_N ("?alignment for & set to Maximum_Aligment", Nam); Set_Alignment (U_Ent, Max_Align); -- All other cases else Set_Alignment (U_Ent, Align); end if; -- 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; --------------- -- Bit_Order -- --------------- -- Bit_Order attribute definition clause when Attribute_Bit_Order => Bit_Order : declare begin if not Is_Record_Type (U_Ent) then Error_Msg_N ("Bit_Order can only be defined for record type", Nam); elsif Duplicate_Clause then null; else Analyze_And_Resolve (Expr, RTE (RE_Bit_Order)); if Etype (Expr) = Any_Type then return; elsif not Is_Static_Expression (Expr) then Flag_Non_Static_Expr ("Bit_Order requires static expression!", Expr); else if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then Set_Reverse_Bit_Order (U_Ent, True); end if; end if; end if; end Bit_Order; -------------------- -- Component_Size -- -------------------- -- Component_Size attribute definition clause when Attribute_Component_Size => Component_Size_Case : declare Csize : constant Uint := Static_Integer (Expr); Ctyp : Entity_Id; Btype : Entity_Id; Biased : Boolean; New_Ctyp : Entity_Id; Decl : Node_Id; begin if not Is_Array_Type (U_Ent) then Error_Msg_N ("component size requires array type", Nam); return; end if; Btype := Base_Type (U_Ent); Ctyp := Component_Type (Btype); if Duplicate_Clause then null; elsif Rep_Item_Too_Early (Btype, N) then null; 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 reflects -- the biased representation of components. We need the subtype -- to get proper conversions on referencing elements of the -- array. Note: component size clauses are ignored in VM mode. if VM_Target = No_VM then if Biased then New_Ctyp := Make_Defining_Identifier (Loc, Chars => New_External_Name (Chars (U_Ent), 'C', 0, 'T')); Decl := Make_Subtype_Declaration (Loc, Defining_Identifier => New_Ctyp, Subtype_Indication => New_Occurrence_Of (Component_Type (Btype), Loc)); Set_Parent (Decl, N); Analyze (Decl, Suppress => All_Checks); Set_Has_Delayed_Freeze (New_Ctyp, False); Set_Esize (New_Ctyp, Csize); Set_RM_Size (New_Ctyp, Csize); Init_Alignment (New_Ctyp); Set_Is_Itype (New_Ctyp, True); Set_Associated_Node_For_Itype (New_Ctyp, U_Ent); Set_Component_Type (Btype, New_Ctyp); Set_Biased (New_Ctyp, N, "component size clause"); end if; Set_Component_Size (Btype, Csize); -- For VM case, we ignore component size clauses else -- Give a warning unless we are in GNAT mode, in which case -- the warning is suppressed since it is not useful. if not GNAT_Mode then Error_Msg_N ("?component size ignored in this configuration", N); 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); end if; end Component_Size_Case; ----------------------- -- Constant_Indexing -- ----------------------- when Attribute_Constant_Indexing => Check_Indexing_Functions; ---------------------- -- Default_Iterator -- ---------------------- when Attribute_Default_Iterator => Default_Iterator : declare Func : Entity_Id; begin if not Is_Tagged_Type (U_Ent) then Error_Msg_N ("aspect Default_Iterator applies to tagged type", Nam); end if; Check_Iterator_Functions; Analyze (Expr); if not Is_Entity_Name (Expr) or else Ekind (Entity (Expr)) /= E_Function then Error_Msg_N ("aspect Iterator must be a function", Expr); else Func := Entity (Expr); end if; if No (First_Formal (Func)) or else Etype (First_Formal (Func)) /= U_Ent then Error_Msg_NE ("Default Iterator must be a primitive of&", Func, U_Ent); end if; end Default_Iterator; ------------------ -- External_Tag -- ------------------ when Attribute_External_Tag => External_Tag : begin if not Is_Tagged_Type (U_Ent) then Error_Msg_N ("should be a tagged type", Nam); end if; if Duplicate_Clause then null; else Analyze_And_Resolve (Expr, Standard_String); if not Is_Static_Expression (Expr) then Flag_Non_Static_Expr ("static string required for tag name!", Nam); end if; if VM_Target = No_VM then Set_Has_External_Tag_Rep_Clause (U_Ent); else Error_Msg_Name_1 := Attr; Error_Msg_N ("% attribute unsupported in this configuration", Nam); end if; if not Is_Library_Level_Entity (U_Ent) then Error_Msg_NE ("?non-unique external tag supplied for &", N, U_Ent); Error_Msg_N ("?\same external tag applies to all subprogram calls", N); Error_Msg_N ("?\corresponding internal tag cannot be obtained", N); end if; end if; end External_Tag; -------------------------- -- Implicit_Dereference -- -------------------------- when Attribute_Implicit_Dereference => -- Legality checks already performed at the point of -- the type declaration, aspect is not delayed. null; ----------- -- Input -- ----------- when Attribute_Input => Analyze_Stream_TSS_Definition (TSS_Stream_Input); Set_Has_Specified_Stream_Input (Ent); ---------------------- -- Iterator_Element -- ---------------------- when Attribute_Iterator_Element => Analyze (Expr); if not Is_Entity_Name (Expr) or else not Is_Type (Entity (Expr)) then Error_Msg_N ("aspect Iterator_Element must be a type", Expr); end if; ------------------- -- Machine_Radix -- ------------------- -- Machine radix attribute definition clause when Attribute_Machine_Radix => Machine_Radix : declare Radix : constant Uint := Static_Integer (Expr); begin if not Is_Decimal_Fixed_Point_Type (U_Ent) then Error_Msg_N ("decimal fixed-point type expected for &", Nam); elsif Duplicate_Clause then null; elsif Radix /= No_Uint then Set_Has_Machine_Radix_Clause (U_Ent); Set_Has_Non_Standard_Rep (Base_Type (U_Ent)); if Radix = 2 then null; elsif Radix = 10 then Set_Machine_Radix_10 (U_Ent); else Error_Msg_N ("machine radix value must be 2 or 10", Expr); end if; end if; end Machine_Radix; ----------------- -- Object_Size -- ----------------- -- Object_Size attribute definition clause when Attribute_Object_Size => Object_Size : declare Size : constant Uint := Static_Integer (Expr); Biased : Boolean; pragma Warnings (Off, Biased); begin if not Is_Type (U_Ent) then Error_Msg_N ("Object_Size cannot be given for &", Nam); elsif Duplicate_Clause then null; else Check_Size (Expr, U_Ent, Size, Biased); if Size /= 8 and then Size /= 16 and then Size /= 32 and then UI_Mod (Size, 64) /= 0 then Error_Msg_N ("Object_Size must be 8, 16, 32, or multiple of 64", Expr); end if; Set_Esize (U_Ent, Size); Set_Has_Object_Size_Clause (U_Ent); Alignment_Check_For_Size_Change (U_Ent, Size); end if; end Object_Size; ------------ -- Output -- ------------ when Attribute_Output => Analyze_Stream_TSS_Definition (TSS_Stream_Output); Set_Has_Specified_Stream_Output (Ent); ---------- -- Read -- ---------- when Attribute_Read => Analyze_Stream_TSS_Definition (TSS_Stream_Read); Set_Has_Specified_Stream_Read (Ent); ---------- -- Size -- ---------- -- Size attribute definition clause when Attribute_Size => Size : declare Size : constant Uint := Static_Integer (Expr); Etyp : Entity_Id; Biased : Boolean; begin FOnly := True; if Duplicate_Clause then null; elsif not Is_Type (U_Ent) and then Ekind (U_Ent) /= E_Variable and then Ekind (U_Ent) /= E_Constant then Error_Msg_N ("size cannot be given for &", Nam); elsif Is_Array_Type (U_Ent) and then not Is_Constrained (U_Ent) then Error_Msg_N ("size cannot be given for unconstrained array", Nam); elsif Size /= No_Uint then if 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 Etyp := Etype (U_Ent); end if; -- Check size, note that Gigi is in charge of checking that the -- size of an array or record type is OK. Also we do not check -- the size in the ordinary fixed-point case, since it is too -- early to do so (there may be subsequent small clause that -- affects the size). We can check the size if a small clause -- has already been given. if not Is_Ordinary_Fixed_Point_Type (U_Ent) or else Has_Small_Clause (U_Ent) then Check_Size (Expr, Etyp, Size, Biased); Set_Biased (U_Ent, N, "size clause", Biased); end if; -- For types set RM_Size and Esize if possible if Is_Type (U_Ent) then Set_RM_Size (U_Ent, Size); -- For elementary types, increase Object_Size to power of 2, -- but not less than a storage unit in any case (normally -- this means it will be byte addressable). -- For all other types, nothing else to do, we leave Esize -- (object size) unset, the back end will set it from the -- size and alignment in an appropriate manner. -- In both cases, we check whether the alignment must be -- reset in the wake of the size change. if Is_Elementary_Type (U_Ent) then if Size <= System_Storage_Unit then Init_Esize (U_Ent, System_Storage_Unit); elsif Size <= 16 then Init_Esize (U_Ent, 16); elsif Size <= 32 then Init_Esize (U_Ent, 32); else Set_Esize (U_Ent, (Size + 63) / 64 * 64); end if; Alignment_Check_For_Size_Change (U_Ent, Esize (U_Ent)); else Alignment_Check_For_Size_Change (U_Ent, Size); end if; -- For objects, set Esize only else if Is_Elementary_Type (Etyp) then if Size /= System_Storage_Unit and then Size /= System_Storage_Unit * 2 and then Size /= System_Storage_Unit * 4 and then Size /= System_Storage_Unit * 8 then Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit); Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8; Error_Msg_N ("size for primitive object must be a power of 2" & " in the range ^-^", N); end if; end if; Set_Esize (U_Ent, Size); end if; Set_Has_Size_Clause (U_Ent); end if; end Size; ----------- -- Small -- ----------- -- Small attribute definition clause when Attribute_Small => Small : declare Implicit_Base : constant Entity_Id := Base_Type (U_Ent); Small : Ureal; begin Analyze_And_Resolve (Expr, Any_Real); if Etype (Expr) = Any_Type then return; elsif not Is_Static_Expression (Expr) then Flag_Non_Static_Expr ("small requires static expression!", Expr); return; else Small := Expr_Value_R (Expr); if Small <= Ureal_0 then Error_Msg_N ("small value must be greater than zero", Expr); return; end if; end if; if not Is_Ordinary_Fixed_Point_Type (U_Ent) then Error_Msg_N ("small requires an ordinary fixed point type", Nam); elsif Has_Small_Clause (U_Ent) then Error_Msg_N ("small already given for &", Nam); elsif Small > Delta_Value (U_Ent) then Error_Msg_N ("small value must not be greater then delta value", Nam); else Set_Small_Value (U_Ent, Small); Set_Small_Value (Implicit_Base, Small); Set_Has_Small_Clause (U_Ent); Set_Has_Small_Clause (Implicit_Base); Set_Has_Non_Standard_Rep (Implicit_Base); end if; end Small; ------------------ -- Storage_Pool -- ------------------ -- Storage_Pool attribute definition clause when Attribute_Storage_Pool | Attribute_Simple_Storage_Pool => declare Pool : Entity_Id; T : Entity_Id; begin if Ekind (U_Ent) = E_Access_Subprogram_Type then Error_Msg_N ("storage pool cannot be given for access-to-subprogram type", Nam); return; 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); return; elsif Is_Derived_Type (U_Ent) then Error_Msg_N ("storage pool cannot be given for a derived access type", Nam); elsif Duplicate_Clause then return; elsif Present (Associated_Storage_Pool (U_Ent)) then Error_Msg_N ("storage pool already given for &", Nam); return; end if; if Id = Attribute_Storage_Pool then Analyze_And_Resolve (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool))); -- In the Simple_Storage_Pool case, we allow a variable of any -- simple storage pool type, so we Resolve without imposing an -- expected type. else Analyze_And_Resolve (Expr); if not Present (Get_Rep_Pragma (Etype (Expr), Name_Simple_Storage_Pool_Type)) then Error_Msg_N ("expression must be of a simple storage pool type", Expr); end if; end if; if not Denotes_Variable (Expr) then Error_Msg_N ("storage pool must be a variable", Expr); return; end if; if Nkind (Expr) = N_Type_Conversion then T := Etype (Expression (Expr)); else T := Etype (Expr); end if; -- The Stack_Bounded_Pool is used internally for implementing -- access types with a Storage_Size. Since it only work properly -- when used on one specific type, we need to check that it is not -- hijacked improperly: -- type T is access Integer; -- for T'Storage_Size use n; -- type Q is access Float; -- for Q'Storage_Size use T'Storage_Size; -- incorrect if RTE_Available (RE_Stack_Bounded_Pool) and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool) then Error_Msg_N ("non-shareable internal Pool", Expr); return; end if; -- If the argument is a name that is not an entity name, then -- we construct a renaming operation to define an entity of -- type storage pool. if not Is_Entity_Name (Expr) and then Is_Object_Reference (Expr) then Pool := Make_Temporary (Loc, 'P', Expr); declare Rnode : constant Node_Id := Make_Object_Renaming_Declaration (Loc, Defining_Identifier => Pool, Subtype_Mark => New_Occurrence_Of (Etype (Expr), Loc), Name => Expr); begin Insert_Before (N, Rnode); Analyze (Rnode); Set_Associated_Storage_Pool (U_Ent, Pool); end; elsif Is_Entity_Name (Expr) then Pool := Entity (Expr); -- If pool is a renamed object, get original one. This can -- happen with an explicit renaming, and within instances. while Present (Renamed_Object (Pool)) and then Is_Entity_Name (Renamed_Object (Pool)) loop Pool := Entity (Renamed_Object (Pool)); end loop; if Present (Renamed_Object (Pool)) and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion and then Is_Entity_Name (Expression (Renamed_Object (Pool))) then Pool := Entity (Expression (Renamed_Object (Pool))); end if; Set_Associated_Storage_Pool (U_Ent, Pool); elsif Nkind (Expr) = N_Type_Conversion and then Is_Entity_Name (Expression (Expr)) and then Nkind (Original_Node (Expr)) = N_Attribute_Reference then Pool := Entity (Expression (Expr)); Set_Associated_Storage_Pool (U_Ent, Pool); else Error_Msg_N ("incorrect reference to a Storage Pool", Expr); return; end if; end; ------------------ -- Storage_Size -- ------------------ -- Storage_Size attribute definition clause when Attribute_Storage_Size => Storage_Size : declare Btype : constant Entity_Id := Base_Type (U_Ent); Sprag : Node_Id; begin if Is_Task_Type (U_Ent) then Check_Restriction (No_Obsolescent_Features, N); if Warn_On_Obsolescent_Feature then Error_Msg_N ("storage size clause for task is an " & "obsolescent feature (RM J.9)?", N); Error_Msg_N ("\use Storage_Size pragma instead?", N); end if; FOnly := True; end if; if not Is_Access_Type (U_Ent) and then Ekind (U_Ent) /= E_Task_Type then Error_Msg_N ("storage size cannot be given for &", Nam); elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then Error_Msg_N ("storage size cannot be given for a derived access type", Nam); elsif Duplicate_Clause then null; else Analyze_And_Resolve (Expr, Any_Integer); if Is_Access_Type (U_Ent) then if Present (Associated_Storage_Pool (U_Ent)) then Error_Msg_N ("storage pool already given for &", Nam); return; end if; if Is_OK_Static_Expression (Expr) and then Expr_Value (Expr) = 0 then Set_No_Pool_Assigned (Btype); end if; else -- Is_Task_Type (U_Ent) Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size); if Present (Sprag) then Error_Msg_Sloc := Sloc (Sprag); Error_Msg_N ("Storage_Size already specified#", Nam); return; end if; end if; Set_Has_Storage_Size_Clause (Btype); end if; end Storage_Size; ----------------- -- Stream_Size -- ----------------- when Attribute_Stream_Size => Stream_Size : declare Size : constant Uint := Static_Integer (Expr); begin if Ada_Version <= Ada_95 then Check_Restriction (No_Implementation_Attributes, N); end if; if Duplicate_Clause then null; elsif Is_Elementary_Type (U_Ent) then if Size /= System_Storage_Unit and then Size /= System_Storage_Unit * 2 and then Size /= System_Storage_Unit * 4 and then Size /= System_Storage_Unit * 8 then Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit); Error_Msg_N ("stream size for elementary type must be a" & " power of 2 and at least ^", N); elsif RM_Size (U_Ent) > Size then Error_Msg_Uint_1 := RM_Size (U_Ent); Error_Msg_N ("stream size for elementary type must be a" & " power of 2 and at least ^", N); end if; Set_Has_Stream_Size_Clause (U_Ent); else Error_Msg_N ("Stream_Size cannot be given for &", Nam); end if; end Stream_Size; ---------------- -- Value_Size -- ---------------- -- Value_Size attribute definition clause when Attribute_Value_Size => Value_Size : declare Size : constant Uint := Static_Integer (Expr); Biased : Boolean; begin if not Is_Type (U_Ent) then Error_Msg_N ("Value_Size cannot be given for &", Nam); elsif Duplicate_Clause then null; elsif Is_Array_Type (U_Ent) and then not Is_Constrained (U_Ent) then Error_Msg_N ("Value_Size cannot be given for unconstrained array", Nam); else if Is_Elementary_Type (U_Ent) then Check_Size (Expr, U_Ent, Size, Biased); Set_Biased (U_Ent, N, "value size clause", Biased); end if; Set_RM_Size (U_Ent, Size); end if; end Value_Size; ----------------------- -- Variable_Indexing -- ----------------------- when Attribute_Variable_Indexing => Check_Indexing_Functions; ----------- -- Write -- ----------- when Attribute_Write => Analyze_Stream_TSS_Definition (TSS_Stream_Write); Set_Has_Specified_Stream_Write (Ent); -- All other attributes cannot be set when others => Error_Msg_N ("attribute& cannot be set with definition clause", N); end case; -- The test for the type being frozen must be performed after any -- expression the clause has been analyzed since the expression itself -- might cause freezing that makes the clause illegal. if Rep_Item_Too_Late (U_Ent, N, FOnly) then return; end if; end Analyze_Attribute_Definition_Clause; ---------------------------- -- Analyze_Code_Statement -- ---------------------------- procedure Analyze_Code_Statement (N : Node_Id) is HSS : constant Node_Id := Parent (N); SBody : constant Node_Id := Parent (HSS); Subp : constant Entity_Id := Current_Scope; Stmt : Node_Id; Decl : Node_Id; StmtO : Node_Id; DeclO : Node_Id; begin -- Analyze and check we get right type, note that this implements the -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that -- is the only way that Asm_Insn could possibly be visible. Analyze_And_Resolve (Expression (N)); if Etype (Expression (N)) = Any_Type then return; elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then Error_Msg_N ("incorrect type for code statement", N); return; end if; Check_Code_Statement (N); -- Make sure we appear in the handled statement sequence of a -- subprogram (RM 13.8(3)). if Nkind (HSS) /= N_Handled_Sequence_Of_Statements or else Nkind (SBody) /= N_Subprogram_Body then Error_Msg_N ("code statement can only appear in body of subprogram", N); return; end if; -- Do remaining checks (RM 13.8(3)) if not already done if not Is_Machine_Code_Subprogram (Subp) then Set_Is_Machine_Code_Subprogram (Subp); -- No exception handlers allowed if Present (Exception_Handlers (HSS)) then Error_Msg_N ("exception handlers not permitted in machine code subprogram", First (Exception_Handlers (HSS))); end if; -- No declarations other than use clauses and pragmas (we allow -- certain internally generated declarations as well). Decl := First (Declarations (SBody)); while Present (Decl) loop DeclO := Original_Node (Decl); if Comes_From_Source (DeclO) and not Nkind_In (DeclO, N_Pragma, N_Use_Package_Clause, N_Use_Type_Clause, N_Implicit_Label_Declaration) then Error_Msg_N ("this declaration not allowed in machine code subprogram", DeclO); end if; Next (Decl); end loop; -- No statements other than code statements, pragmas, and labels. -- Again we allow certain internally generated statements. -- In Ada 2012, qualified expressions are names, and the code -- statement is initially parsed as a procedure call. Stmt := First (Statements (HSS)); while Present (Stmt) loop StmtO := Original_Node (Stmt); -- A procedure call transformed into a code statement is OK. if Ada_Version >= Ada_2012 and then Nkind (StmtO) = N_Procedure_Call_Statement and then Nkind (Name (StmtO)) = N_Qualified_Expression then null; elsif Comes_From_Source (StmtO) and then not Nkind_In (StmtO, N_Pragma, N_Label, N_Code_Statement) then Error_Msg_N ("this statement is not allowed in machine code subprogram", StmtO); end if; Next (Stmt); end loop; end if; end Analyze_Code_Statement; ----------------------------------------------- -- Analyze_Enumeration_Representation_Clause -- ----------------------------------------------- procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is Ident : constant Node_Id := Identifier (N); Aggr : constant Node_Id := Array_Aggregate (N); Enumtype : Entity_Id; Elit : Entity_Id; Expr : Node_Id; Assoc : Node_Id; Choice : Node_Id; Val : Uint; Err : Boolean := False; -- Set True to avoid cascade errors and crashes on incorrect source code 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 return; end if; -- First some basic error checks Find_Type (Ident); Enumtype := Entity (Ident); if Enumtype = Any_Type or else Rep_Item_Too_Early (Enumtype, N) then return; else Enumtype := Underlying_Type (Enumtype); end if; if not Is_Enumeration_Type (Enumtype) then Error_Msg_NE ("enumeration type required, found}", Ident, First_Subtype (Enumtype)); return; end if; -- Ignore rep clause on generic actual type. This will already have -- been flagged on the template as an error, and this is the safest -- way to ensure we don't get a junk cascaded message in the instance. if Is_Generic_Actual_Type (Enumtype) then return; -- Type must be in current scope elsif Scope (Enumtype) /= Current_Scope then Error_Msg_N ("type must be declared in this scope", Ident); return; -- Type must be a first subtype elsif not Is_First_Subtype (Enumtype) then Error_Msg_N ("cannot give enumeration rep clause for subtype", N); return; -- Ignore duplicate rep clause elsif Has_Enumeration_Rep_Clause (Enumtype) then Error_Msg_N ("duplicate enumeration rep clause ignored", N); return; -- Don't allow rep clause for standard [wide_[wide_]]character elsif Is_Standard_Character_Type (Enumtype) then Error_Msg_N ("enumeration rep clause not allowed for this type", N); return; -- Check that the expression is a proper aggregate (no parentheses) elsif Paren_Count (Aggr) /= 0 then Error_Msg ("extra parentheses surrounding aggregate not allowed", First_Sloc (Aggr)); return; -- All tests passed, so set rep clause in place else Set_Has_Enumeration_Rep_Clause (Enumtype); Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype)); end if; -- Now we process the aggregate. Note that we don't use the normal -- aggregate code for this purpose, because we don't want any of the -- normal expansion activities, and a number of special semantic -- rules apply (including the component type being any integer type) Elit := First_Literal (Enumtype); -- First the positional entries if any if Present (Expressions (Aggr)) then Expr := First (Expressions (Aggr)); while Present (Expr) loop if No (Elit) then Error_Msg_N ("too many entries in aggregate", Expr); return; end if; Val := Static_Integer (Expr); -- Err signals that we found some incorrect entries processing -- the list. The final checks for completeness and ordering are -- skipped in this case. if Val = No_Uint then Err := True; elsif Val < Lo or else Hi < Val then Error_Msg_N ("value outside permitted range", Expr); Err := True; end if; Set_Enumeration_Rep (Elit, Val); Set_Enumeration_Rep_Expr (Elit, Expr); Next (Expr); Next (Elit); end loop; end if; -- Now process the named entries if present if Present (Component_Associations (Aggr)) then Assoc := First (Component_Associations (Aggr)); while Present (Assoc) loop Choice := First (Choices (Assoc)); if Present (Next (Choice)) then Error_Msg_N ("multiple choice not allowed here", Next (Choice)); Err := True; end if; if Nkind (Choice) = N_Others_Choice then Error_Msg_N ("others choice not allowed here", Choice); Err := True; elsif Nkind (Choice) = N_Range then -- ??? should allow zero/one element range here Error_Msg_N ("range not allowed here", Choice); Err := True; else Analyze_And_Resolve (Choice, Enumtype); if Error_Posted (Choice) then Err := True; end if; if not Err then if Is_Entity_Name (Choice) and then Is_Type (Entity (Choice)) then Error_Msg_N ("subtype name not allowed here", Choice); Err := True; -- ??? should allow static subtype with zero/one entry elsif Etype (Choice) = Base_Type (Enumtype) then if not Is_Static_Expression (Choice) then Flag_Non_Static_Expr ("non-static expression used for choice!", Choice); Err := True; else Elit := Expr_Value_E (Choice); if Present (Enumeration_Rep_Expr (Elit)) then Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit)); Error_Msg_NE ("representation for& previously given#", Choice, Elit); Err := True; end if; Set_Enumeration_Rep_Expr (Elit, Expression (Assoc)); Expr := Expression (Assoc); Val := Static_Integer (Expr); if Val = No_Uint then Err := True; elsif Val < Lo or else Hi < Val then Error_Msg_N ("value outside permitted range", Expr); Err := True; end if; Set_Enumeration_Rep (Elit, Val); end if; end if; end if; end if; Next (Assoc); end loop; end if; -- Aggregate is fully processed. Now we check that a full set of -- representations was given, and that they are in range and in order. -- These checks are only done if no other errors occurred. if not Err then Min := No_Uint; Max := No_Uint; Elit := First_Literal (Enumtype); while Present (Elit) loop if No (Enumeration_Rep_Expr (Elit)) then Error_Msg_NE ("missing representation for&!", N, Elit); else Val := Enumeration_Rep (Elit); if Min = No_Uint then Min := Val; end if; if Val /= No_Uint then if Max /= No_Uint and then Val <= Max then Error_Msg_NE ("enumeration value for& not ordered!", Enumeration_Rep_Expr (Elit), Elit); end if; Max_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 Val /= Enumeration_Pos (Elit) then Set_Has_Non_Standard_Rep (Base_Type (Enumtype)); end if; end if; Next (Elit); end loop; -- Now set proper size information declare Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype)); begin if Has_Size_Clause (Enumtype) then -- 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)); -- 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_Biased (Enumtype, Size_Clause (Enumtype), "size clause"); end if; end if; else Set_RM_Size (Enumtype, Minsize); Set_Enum_Esize (Enumtype); end if; Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype)); Set_Esize (Base_Type (Enumtype), Esize (Enumtype)); Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype)); end; end if; -- We repeat the too late test in case it froze itself! if Rep_Item_Too_Late (Enumtype, N) then null; end if; end Analyze_Enumeration_Representation_Clause; ---------------------------- -- Analyze_Free_Statement -- ---------------------------- procedure Analyze_Free_Statement (N : Node_Id) is begin Analyze (Expression (N)); end Analyze_Free_Statement; --------------------------- -- Analyze_Freeze_Entity -- --------------------------- procedure Analyze_Freeze_Entity (N : Node_Id) is E : constant Entity_Id := Entity (N); begin -- 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_2005 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; -- Check CPP types 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 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; -- If we have a type with predicates, build predicate function if Is_Type (E) and then Has_Predicates (E) then Build_Predicate_Function (E, N); end if; -- If type has delayed aspects, this is where we do the preanalysis at -- the freeze point, as part of the consistent visibility check. Note -- that this must be done after calling Build_Predicate_Function or -- Build_Invariant_Procedure since these subprograms fix occurrences of -- the subtype name in the saved expression so that they will not cause -- trouble in the preanalysis. if Has_Delayed_Aspects (E) then declare Ritem : Node_Id; begin -- Look for aspect specification entries for this entity Ritem := First_Rep_Item (E); while Present (Ritem) loop if Nkind (Ritem) = N_Aspect_Specification and then Entity (Ritem) = E and then Is_Delayed_Aspect (Ritem) and then Scope (E) = Current_Scope then Check_Aspect_At_Freeze_Point (Ritem); end if; Next_Rep_Item (Ritem); end loop; end; end if; 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 if not Is_Record_Type (Rectype) then Error_Msg_NE ("record type required, found}", Ident, First_Subtype (Rectype)); return; elsif Scope (Rectype) /= Current_Scope then Error_Msg_N ("type must be declared in this scope", N); return; elsif not Is_First_Subtype (Rectype) then Error_Msg_N ("cannot give record rep clause for subtype", N); return; elsif Has_Record_Rep_Clause (Rectype) then Error_Msg_N ("duplicate record rep clause ignored", N); return; elsif Rep_Item_Too_Late (Rectype, N) then return; end if; if Present (Mod_Clause (N)) then declare Loc : constant Source_Ptr := Sloc (N); M : constant Node_Id := Mod_Clause (N); P : constant List_Id := Pragmas_Before (M); AtM_Nod : Node_Id; Mod_Val : Uint; pragma Warnings (Off, Mod_Val); begin Check_Restriction (No_Obsolescent_Features, Mod_Clause (N)); if Warn_On_Obsolescent_Feature then Error_Msg_N ("mod clause is an obsolescent feature (RM J.8)?", N); Error_Msg_N ("\use alignment attribute definition clause instead?", N); end if; if Present (P) then Analyze_List (P); end if; -- In ASIS_Mode mode, expansion is disabled, but we must convert -- the Mod clause into an alignment clause anyway, so that the -- back-end can compute and back-annotate properly the size and -- alignment of types that may include this record. -- This seems dubious, this destroys the source tree in a manner -- not detectable by ASIS ??? if Operating_Mode = Check_Semantics and then ASIS_Mode then AtM_Nod := Make_Attribute_Definition_Clause (Loc, Name => New_Reference_To (Base_Type (Rectype), Loc), Chars => Name_Alignment, Expression => Relocate_Node (Expression (M))); Set_From_At_Mod (AtM_Nod); Insert_After (N, AtM_Nod); Mod_Val := Get_Alignment_Value (Expression (AtM_Nod)); Set_Mod_Clause (N, Empty); else -- Get the alignment value to perform error checking Mod_Val := Get_Alignment_Value (Expression (M)); end if; end; end if; -- For untagged types, clear any existing component clauses for the -- type. If the type is derived, this is what allows us to override -- a rep clause for the parent. For type extensions, the representation -- of the inherited components is inherited, so we want to keep previous -- component clauses for completeness. if not Is_Tagged_Type (Rectype) then Comp := First_Component_Or_Discriminant (Rectype); while Present (Comp) loop Set_Component_Clause (Comp, Empty); Next_Component_Or_Discriminant (Comp); end loop; end if; -- All done if no component clauses CC := First (Component_Clauses (N)); if No (CC) then return; 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)); -- Process the component clauses while Present (CC) loop -- Pragma if Nkind (CC) = N_Pragma then Analyze (CC); -- The only pragma of interest is Complete_Representation if Pragma_Name (CC) = Name_Complete_Representation then CR_Pragma := CC; end if; -- Processing for real component clause else Posit := Static_Integer (Position (CC)); Fbit := Static_Integer (First_Bit (CC)); Lbit := Static_Integer (Last_Bit (CC)); if Posit /= No_Uint and then Fbit /= No_Uint and then Lbit /= No_Uint then if Posit < 0 then Error_Msg_N ("position cannot be negative", Position (CC)); elsif Fbit < 0 then Error_Msg_N ("first bit cannot be negative", First_Bit (CC)); -- The Last_Bit specified in a component clause must not be -- less than the First_Bit minus one (RM-13.5.1(10)). elsif Lbit < Fbit - 1 then Error_Msg_N ("last bit cannot be less than first bit minus one", Last_Bit (CC)); -- Values look OK, so find the corresponding record component -- Even though the syntax allows an attribute reference for -- implementation-defined components, GNAT does not allow the -- tag to get an explicit position. elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then if Attribute_Name (Component_Name (CC)) = Name_Tag then Error_Msg_N ("position of tag cannot be specified", CC); else Error_Msg_N ("illegal component name", CC); end if; else Comp := First_Entity (Rectype); while Present (Comp) loop exit when Chars (Comp) = Chars (Component_Name (CC)); Next_Entity (Comp); end loop; if No (Comp) then -- Maybe component of base type that is absent from -- statically constrained first subtype. Comp := First_Entity (Base_Type (Rectype)); while Present (Comp) loop exit when Chars (Comp) = Chars (Component_Name (CC)); Next_Entity (Comp); end loop; end if; if No (Comp) then Error_Msg_N ("component clause is for non-existent field", CC); -- 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 -- if this is an inherited component. In a double fault, -- there may be a duplicate inconsistent clause for an -- inherited component. if Scope (Original_Record_Component (Comp)) = Rectype or else Parent (Component_Clause (Comp)) = N then Error_Msg_Sloc := Sloc (Component_Clause (Comp)); Error_Msg_N ("component clause previously given#", CC); else declare Rep1 : constant Node_Id := Component_Clause (Comp); begin if Intval (Position (Rep1)) /= Intval (Position (CC)) or else Intval (First_Bit (Rep1)) /= Intval (First_Bit (CC)) or else Intval (Last_Bit (Rep1)) /= Intval (Last_Bit (CC)) then Error_Msg_N ("component clause inconsistent " & "with representation of ancestor", CC); elsif Warn_On_Redundant_Constructs then Error_Msg_N ("?redundant component clause " & "for inherited component!", CC); end if; 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. Generate_Reference (Comp, Component_Name (CC), Set_Ref => False); Set_Entity (Component_Name (CC), Comp); -- Update Fbit and Lbit to the actual bit number Fbit := Fbit + UI_From_Int (SSU) * Posit; Lbit := Lbit + UI_From_Int (SSU) * Posit; if Has_Size_Clause (Rectype) and then RM_Size (Rectype) <= Lbit then Error_Msg_N ("bit number out of range of specified size", Last_Bit (CC)); else Set_Component_Clause (Comp, CC); Set_Component_Bit_Offset (Comp, Fbit); Set_Esize (Comp, 1 + (Lbit - Fbit)); Set_Normalized_First_Bit (Comp, Fbit mod SSU); Set_Normalized_Position (Comp, Fbit / SSU); 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 size overrides size clause for&", Component_Name (CC), Etype (Comp)); end if; -- This information is also set in the corresponding -- component of the base type, found by accessing the -- Original_Record_Component link if it is present. Ocomp := Original_Record_Component (Comp); if Hbit < Lbit then Hbit := Lbit; end if; Check_Size (Component_Name (CC), Etype (Comp), Esize (Comp), Biased); Set_Biased (Comp, First_Node (CC), "component clause", Biased); if Present (Ocomp) then Set_Component_Clause (Ocomp, CC); Set_Component_Bit_Offset (Ocomp, Fbit); Set_Normalized_First_Bit (Ocomp, Fbit mod SSU); Set_Normalized_Position (Ocomp, Fbit / SSU); Set_Esize (Ocomp, 1 + (Lbit - Fbit)); Set_Normalized_Position_Max (Ocomp, Normalized_Position (Ocomp)); -- 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; if Esize (Comp) < 0 then Error_Msg_N ("component size is negative", CC); end if; end if; end if; end if; end if; end if; Next (CC); end loop; -- 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; ------------------------------- -- Build_Invariant_Procedure -- ------------------------------- -- The procedure that is constructed here has the form -- procedure typInvariant (Ixxx : typ) is -- begin -- pragma Check (Invariant, exp, "failed invariant from xxx"); -- pragma Check (Invariant, exp, "failed invariant from xxx"); -- ... -- pragma Check (Invariant, exp, "failed inherited invariant from xxx"); -- ... -- end typInvariant; procedure Build_Invariant_Procedure (Typ : Entity_Id; N : Node_Id) is Loc : constant Source_Ptr := Sloc (Typ); Stmts : List_Id; Spec : Node_Id; SId : Entity_Id; PDecl : Node_Id; PBody : Node_Id; Visible_Decls : constant List_Id := Visible_Declarations (N); Private_Decls : constant List_Id := Private_Declarations (N); procedure Add_Invariants (T : Entity_Id; Inherit : Boolean); -- Appends statements to Stmts for any invariants in the rep item chain -- of the given type. If Inherit is False, then we only process entries -- on the chain for the type Typ. If Inherit is True, then we ignore any -- Invariant aspects, but we process all Invariant'Class aspects, adding -- "inherited" to the exception message and generating an informational -- message about the inheritance of an invariant. Object_Name : constant Name_Id := New_Internal_Name ('I'); -- Name for argument of invariant procedure Object_Entity : constant Node_Id := Make_Defining_Identifier (Loc, Object_Name); -- The procedure declaration entity for the argument -------------------- -- Add_Invariants -- -------------------- procedure Add_Invariants (T : Entity_Id; Inherit : Boolean) is Ritem : Node_Id; Arg1 : Node_Id; Arg2 : Node_Id; Arg3 : Node_Id; Exp : Node_Id; Loc : Source_Ptr; Assoc : List_Id; Str : String_Id; procedure Replace_Type_Reference (N : Node_Id); -- Replace a single occurrence N of the subtype name with a reference -- to the formal of the predicate function. N can be an identifier -- referencing the subtype, or a selected component, representing an -- appropriately qualified occurrence of the subtype name. procedure Replace_Type_References is new Replace_Type_References_Generic (Replace_Type_Reference); -- Traverse an expression replacing all occurrences of the subtype -- name with appropriate references to the object that is the formal -- parameter of the predicate function. Note that we must ensure -- that the type and entity information is properly set in the -- replacement node, since we will do a Preanalyze call of this -- expression without proper visibility of the procedure argument. ---------------------------- -- Replace_Type_Reference -- ---------------------------- procedure Replace_Type_Reference (N : Node_Id) is begin -- Invariant'Class, replace with T'Class (obj) if Class_Present (Ritem) then Rewrite (N, Make_Type_Conversion (Loc, Subtype_Mark => Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (T, Loc), Attribute_Name => Name_Class), Expression => Make_Identifier (Loc, Object_Name))); Set_Entity (Expression (N), Object_Entity); Set_Etype (Expression (N), Typ); -- Invariant, replace with obj else Rewrite (N, Make_Identifier (Loc, Object_Name)); Set_Entity (N, Object_Entity); Set_Etype (N, Typ); end if; end Replace_Type_Reference; -- Start of processing for Add_Invariants begin Ritem := First_Rep_Item (T); while Present (Ritem) loop if Nkind (Ritem) = N_Pragma and then Pragma_Name (Ritem) = Name_Invariant then Arg1 := First (Pragma_Argument_Associations (Ritem)); Arg2 := Next (Arg1); Arg3 := Next (Arg2); Arg1 := Get_Pragma_Arg (Arg1); Arg2 := Get_Pragma_Arg (Arg2); -- For Inherit case, ignore Invariant, process only Class case if Inherit then if not Class_Present (Ritem) then goto Continue; end if; -- For Inherit false, process only item for right type else if Entity (Arg1) /= Typ then goto Continue; end if; end if; if No (Stmts) then Stmts := Empty_List; end if; Exp := New_Copy_Tree (Arg2); Loc := Sloc (Exp); -- We need to replace any occurrences of the name of the type -- with references to the object, converted to type'Class in -- the case of Invariant'Class aspects. Replace_Type_References (Exp, Chars (T)); -- If this invariant comes from an aspect, find the aspect -- specification, and replace the saved expression because -- we need the subtype references replaced for the calls to -- Preanalyze_Spec_Expressin in Check_Aspect_At_Freeze_Point -- and Check_Aspect_At_End_Of_Declarations. if From_Aspect_Specification (Ritem) then declare Aitem : Node_Id; begin -- Loop to find corresponding aspect, note that this -- must be present given the pragma is marked delayed. Aitem := Next_Rep_Item (Ritem); while Present (Aitem) loop if Nkind (Aitem) = N_Aspect_Specification and then Aspect_Rep_Item (Aitem) = Ritem then Set_Entity (Identifier (Aitem), New_Copy_Tree (Exp)); exit; end if; Aitem := Next_Rep_Item (Aitem); end loop; end; end if; -- Now we need to preanalyze the expression to properly capture -- the visibility in the visible part. The expression will not -- be analyzed for real until the body is analyzed, but that is -- at the end of the private part and has the wrong visibility. Set_Parent (Exp, N); Preanalyze_Spec_Expression (Exp, Standard_Boolean); -- Build first two arguments for Check pragma Assoc := New_List ( Make_Pragma_Argument_Association (Loc, Expression => Make_Identifier (Loc, Name_Invariant)), Make_Pragma_Argument_Association (Loc, Expression => Exp)); -- Add message if present in Invariant pragma if Present (Arg3) then Str := Strval (Get_Pragma_Arg (Arg3)); -- If inherited case, and message starts "failed invariant", -- change it to be "failed inherited invariant". if Inherit then String_To_Name_Buffer (Str); if Name_Buffer (1 .. 16) = "failed invariant" then Insert_Str_In_Name_Buffer ("inherited ", 8); Str := String_From_Name_Buffer; end if; end if; Append_To (Assoc, Make_Pragma_Argument_Association (Loc, Expression => Make_String_Literal (Loc, Str))); end if; -- Add Check pragma to list of statements Append_To (Stmts, Make_Pragma (Loc, Pragma_Identifier => Make_Identifier (Loc, Name_Check), Pragma_Argument_Associations => Assoc)); -- If Inherited case and option enabled, output info msg. Note -- that we know this is a case of Invariant'Class. if Inherit and Opt.List_Inherited_Aspects then Error_Msg_Sloc := Sloc (Ritem); Error_Msg_N ("?info: & inherits `Invariant''Class` aspect from #", Typ); end if; end if; <<Continue>> Next_Rep_Item (Ritem); end loop; end Add_Invariants; -- Start of processing for Build_Invariant_Procedure begin Stmts := No_List; PDecl := Empty; PBody := Empty; Set_Etype (Object_Entity, Typ); -- Add invariants for the current type Add_Invariants (Typ, Inherit => False); -- Add invariants for parent types declare Current_Typ : Entity_Id; Parent_Typ : Entity_Id; begin Current_Typ := Typ; loop Parent_Typ := Etype (Current_Typ); if Is_Private_Type (Parent_Typ) and then Present (Full_View (Base_Type (Parent_Typ))) then Parent_Typ := Full_View (Base_Type (Parent_Typ)); end if; exit when Parent_Typ = Current_Typ; Current_Typ := Parent_Typ; Add_Invariants (Current_Typ, Inherit => True); end loop; end; -- Build the procedure if we generated at least one Check pragma if Stmts /= No_List then -- Build procedure declaration SId := Make_Defining_Identifier (Loc, Chars => New_External_Name (Chars (Typ), "Invariant")); Set_Has_Invariants (SId); Set_Invariant_Procedure (Typ, SId); Spec := Make_Procedure_Specification (Loc, Defining_Unit_Name => SId, Parameter_Specifications => New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => Object_Entity, Parameter_Type => New_Occurrence_Of (Typ, Loc)))); PDecl := Make_Subprogram_Declaration (Loc, Specification => Spec); -- Build procedure body SId := Make_Defining_Identifier (Loc, Chars => New_External_Name (Chars (Typ), "Invariant")); Spec := Make_Procedure_Specification (Loc, Defining_Unit_Name => SId, Parameter_Specifications => New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => Make_Defining_Identifier (Loc, Object_Name), Parameter_Type => New_Occurrence_Of (Typ, Loc)))); PBody := Make_Subprogram_Body (Loc, Specification => Spec, Declarations => Empty_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts)); -- Insert procedure declaration and spec at the appropriate points. -- Skip this if there are no private declarations (that's an error -- that will be diagnosed elsewhere, and there is no point in having -- an invariant procedure set if the full declaration is missing). if Present (Private_Decls) then -- The spec goes at the end of visible declarations, but they have -- already been analyzed, so we need to explicitly do the analyze. Append_To (Visible_Decls, PDecl); Analyze (PDecl); -- The body goes at the end of the private declarations, which we -- have not analyzed yet, so we do not need to perform an explicit -- analyze call. We skip this if there are no private declarations -- (this is an error that will be caught elsewhere); Append_To (Private_Decls, PBody); -- If the invariant appears on the full view of a type, the -- analysis of the private part is complete, and we must -- analyze the new body explicitly. if In_Private_Part (Current_Scope) then Analyze (PBody); end if; end if; end if; end Build_Invariant_Procedure; ------------------------------ -- Build_Predicate_Function -- ------------------------------ -- The procedure that is constructed here has the form -- function typPredicate (Ixxx : typ) return Boolean is -- begin -- return -- exp1 and then exp2 and then ... -- and then typ1Predicate (typ1 (Ixxx)) -- and then typ2Predicate (typ2 (Ixxx)) -- and then ...; -- end typPredicate; -- Here exp1, and exp2 are expressions from Predicate pragmas. Note that -- this is the point at which these expressions get analyzed, providing the -- required delay, and typ1, typ2, are entities from which predicates are -- inherited. Note that we do NOT generate Check pragmas, that's because we -- use this function even if checks are off, e.g. for membership tests. procedure Build_Predicate_Function (Typ : Entity_Id; N : Node_Id) is Loc : constant Source_Ptr := Sloc (Typ); Spec : Node_Id; SId : Entity_Id; FDecl : Node_Id; FBody : Node_Id; Expr : Node_Id; -- This is the expression for the return statement in the function. It -- is build by connecting the component predicates with AND THEN. procedure Add_Call (T : Entity_Id); -- Includes a call to the predicate function for type T in Expr if T -- has predicates and Predicate_Function (T) is non-empty. procedure Add_Predicates; -- Appends expressions for any Predicate pragmas in the rep item chain -- Typ to Expr. Note that we look only at items for this exact entity. -- Inheritance of predicates for the parent type is done by calling the -- Predicate_Function of the parent type, using Add_Call above. Object_Name : constant Name_Id := New_Internal_Name ('I'); -- Name for argument of Predicate procedure Object_Entity : constant Entity_Id := Make_Defining_Identifier (Loc, Object_Name); -- The entity for the spec entity for the argument Dynamic_Predicate_Present : Boolean := False; -- Set True if a dynamic predicate is present, results in the entire -- predicate being considered dynamic even if it looks static Static_Predicate_Present : Node_Id := Empty; -- Set to N_Pragma node for a static predicate if one is encountered. -------------- -- Add_Call -- -------------- procedure Add_Call (T : Entity_Id) is Exp : Node_Id; begin if Present (T) and then Present (Predicate_Function (T)) then Set_Has_Predicates (Typ); -- Build the call to the predicate function of T Exp := Make_Predicate_Call (T, Convert_To (T, Make_Identifier (Loc, Object_Name))); -- Add call to evolving expression, using AND THEN if needed if No (Expr) then Expr := Exp; else Expr := Make_And_Then (Loc, Left_Opnd => Relocate_Node (Expr), Right_Opnd => Exp); end if; -- Output info message on inheritance if required. Note we do not -- give this information for generic actual types, since it is -- unwelcome noise in that case in instantiations. We also -- generally suppress the message in instantiations, and also -- if it involves internal names. if Opt.List_Inherited_Aspects and then not Is_Generic_Actual_Type (Typ) and then Instantiation_Depth (Sloc (Typ)) = 0 and then not Is_Internal_Name (Chars (T)) and then not Is_Internal_Name (Chars (Typ)) then Error_Msg_Sloc := Sloc (Predicate_Function (T)); Error_Msg_Node_2 := T; Error_Msg_N ("?info: & inherits predicate from & #", Typ); end if; end if; end Add_Call; -------------------- -- Add_Predicates -- -------------------- procedure Add_Predicates is Ritem : Node_Id; Arg1 : Node_Id; Arg2 : Node_Id; procedure Replace_Type_Reference (N : Node_Id); -- Replace a single occurrence N of the subtype name with a reference -- to the formal of the predicate function. N can be an identifier -- referencing the subtype, or a selected component, representing an -- appropriately qualified occurrence of the subtype name. procedure Replace_Type_References is new Replace_Type_References_Generic (Replace_Type_Reference); -- Traverse an expression changing every occurrence of an identifier -- whose name matches the name of the subtype with a reference to -- the formal parameter of the predicate function. ---------------------------- -- Replace_Type_Reference -- ---------------------------- procedure Replace_Type_Reference (N : Node_Id) is begin Rewrite (N, Make_Identifier (Loc, Object_Name)); Set_Entity (N, Object_Entity); Set_Etype (N, Typ); end Replace_Type_Reference; -- Start of processing for Add_Predicates begin Ritem := First_Rep_Item (Typ); while Present (Ritem) loop if Nkind (Ritem) = N_Pragma and then Pragma_Name (Ritem) = Name_Predicate then if Present (Corresponding_Aspect (Ritem)) then case Chars (Identifier (Corresponding_Aspect (Ritem))) is when Name_Dynamic_Predicate => Dynamic_Predicate_Present := True; when Name_Static_Predicate => Static_Predicate_Present := Ritem; when others => null; end case; end if; -- Acquire arguments Arg1 := First (Pragma_Argument_Associations (Ritem)); Arg2 := Next (Arg1); Arg1 := Get_Pragma_Arg (Arg1); Arg2 := Get_Pragma_Arg (Arg2); -- See if this predicate pragma is for the current type or for -- its full view. A predicate on a private completion is placed -- on the partial view beause this is the visible entity that -- is frozen. if Entity (Arg1) = Typ or else Full_View (Entity (Arg1)) = Typ then -- We have a match, this entry is for our subtype -- We need to replace any occurrences of the name of the -- type with references to the object. Replace_Type_References (Arg2, Chars (Typ)); -- If this predicate comes from an aspect, find the aspect -- specification, and replace the saved expression because -- we need the subtype references replaced for the calls to -- Preanalyze_Spec_Expressin in Check_Aspect_At_Freeze_Point -- and Check_Aspect_At_End_Of_Declarations. if From_Aspect_Specification (Ritem) then declare Aitem : Node_Id; begin -- Loop to find corresponding aspect, note that this -- must be present given the pragma is marked delayed. Aitem := Next_Rep_Item (Ritem); loop if Nkind (Aitem) = N_Aspect_Specification and then Aspect_Rep_Item (Aitem) = Ritem then Set_Entity (Identifier (Aitem), New_Copy_Tree (Arg2)); exit; end if; Aitem := Next_Rep_Item (Aitem); end loop; end; end if; -- Now we can add the expression if No (Expr) then Expr := Relocate_Node (Arg2); -- There already was a predicate, so add to it else Expr := Make_And_Then (Loc, Left_Opnd => Relocate_Node (Expr), Right_Opnd => Relocate_Node (Arg2)); end if; end if; end if; Next_Rep_Item (Ritem); end loop; end Add_Predicates; -- Start of processing for Build_Predicate_Function begin -- Initialize for construction of statement list Expr := Empty; -- Return if already built or if type does not have predicates if not Has_Predicates (Typ) or else Present (Predicate_Function (Typ)) then return; end if; -- Add Predicates for the current type Add_Predicates; -- Add predicates for ancestor if present declare Atyp : constant Entity_Id := Nearest_Ancestor (Typ); begin if Present (Atyp) then Add_Call (Atyp); end if; end; -- If we have predicates, build the function if Present (Expr) then -- Build function declaration pragma Assert (Has_Predicates (Typ)); SId := Make_Defining_Identifier (Loc, Chars => New_External_Name (Chars (Typ), "Predicate")); Set_Has_Predicates (SId); Set_Predicate_Function (Typ, SId); -- The predicate function is shared between views of a type. if Is_Private_Type (Typ) and then Present (Full_View (Typ)) then Set_Predicate_Function (Full_View (Typ), SId); end if; Spec := Make_Function_Specification (Loc, Defining_Unit_Name => SId, Parameter_Specifications => New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => Object_Entity, Parameter_Type => New_Occurrence_Of (Typ, Loc))), Result_Definition => New_Occurrence_Of (Standard_Boolean, Loc)); FDecl := Make_Subprogram_Declaration (Loc, Specification => Spec); -- Build function body SId := Make_Defining_Identifier (Loc, Chars => New_External_Name (Chars (Typ), "Predicate")); Spec := Make_Function_Specification (Loc, Defining_Unit_Name => SId, Parameter_Specifications => New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => Make_Defining_Identifier (Loc, Object_Name), Parameter_Type => New_Occurrence_Of (Typ, Loc))), Result_Definition => New_Occurrence_Of (Standard_Boolean, Loc)); FBody := Make_Subprogram_Body (Loc, Specification => Spec, Declarations => Empty_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List ( Make_Simple_Return_Statement (Loc, Expression => Expr)))); -- Insert declaration before freeze node and body after Insert_Before_And_Analyze (N, FDecl); Insert_After_And_Analyze (N, FBody); -- Deal with static predicate case if Ekind_In (Typ, E_Enumeration_Subtype, E_Modular_Integer_Subtype, E_Signed_Integer_Subtype) and then Is_Static_Subtype (Typ) and then not Dynamic_Predicate_Present then Build_Static_Predicate (Typ, Expr, Object_Name); if Present (Static_Predicate_Present) and No (Static_Predicate (Typ)) then Error_Msg_F ("expression does not have required form for " & "static predicate", Next (First (Pragma_Argument_Associations (Static_Predicate_Present)))); end if; end if; end if; end Build_Predicate_Function; ---------------------------- -- Build_Static_Predicate -- ---------------------------- procedure Build_Static_Predicate (Typ : Entity_Id; Expr : Node_Id; Nam : Name_Id) is Loc : constant Source_Ptr := Sloc (Expr); Non_Static : exception; -- Raised if something non-static is found Btyp : constant Entity_Id := Base_Type (Typ); BLo : constant Uint := Expr_Value (Type_Low_Bound (Btyp)); BHi : constant Uint := Expr_Value (Type_High_Bound (Btyp)); -- Low bound and high bound value of base type of Typ TLo : constant Uint := Expr_Value (Type_Low_Bound (Typ)); THi : constant Uint := Expr_Value (Type_High_Bound (Typ)); -- Low bound and high bound values of static subtype Typ type REnt is record Lo, Hi : Uint; end record; -- One entry in a Rlist value, a single REnt (range entry) value -- denotes one range from Lo to Hi. To represent a single value -- range Lo = Hi = value. type RList is array (Nat range <>) of REnt; -- A list of ranges. The ranges are sorted in increasing order, -- and are disjoint (there is a gap of at least one value between -- each range in the table). A value is in the set of ranges in -- Rlist if it lies within one of these ranges False_Range : constant RList := RList'(1 .. 0 => REnt'(No_Uint, No_Uint)); -- An empty set of ranges represents a range list that can never be -- satisfied, since there are no ranges in which the value could lie, -- so it does not lie in any of them. False_Range is a canonical value -- for this empty set, but general processing should test for an Rlist -- with length zero (see Is_False predicate), since other null ranges -- may appear which must be treated as False. True_Range : constant RList := RList'(1 => REnt'(BLo, BHi)); -- Range representing True, value must be in the base range function "and" (Left, Right : RList) return RList; -- And's together two range lists, returning a range list. This is -- a set intersection operation. function "or" (Left, Right : RList) return RList; -- Or's together two range lists, returning a range list. This is a -- set union operation. function "not" (Right : RList) return RList; -- Returns complement of a given range list, i.e. a range list -- representing all the values in TLo .. THi that are not in the -- input operand Right. function Build_Val (V : Uint) return Node_Id; -- Return an analyzed N_Identifier node referencing this value, suitable -- for use as an entry in the Static_Predicate list. This node is typed -- with the base type. function Build_Range (Lo, Hi : Uint) return Node_Id; -- Return an analyzed N_Range node referencing this range, suitable -- for use as an entry in the Static_Predicate list. This node is typed -- with the base type. function Get_RList (Exp : Node_Id) return RList; -- This is a recursive routine that converts the given expression into -- a list of ranges, suitable for use in building the static predicate. function Is_False (R : RList) return Boolean; pragma Inline (Is_False); -- Returns True if the given range list is empty, and thus represents -- a False list of ranges that can never be satisfied. function Is_True (R : RList) return Boolean; -- Returns True if R trivially represents the True predicate by having -- a single range from BLo to BHi. function Is_Type_Ref (N : Node_Id) return Boolean; pragma Inline (Is_Type_Ref); -- Returns if True if N is a reference to the type for the predicate in -- the expression (i.e. if it is an identifier whose Chars field matches -- the Nam given in the call). function Lo_Val (N : Node_Id) return Uint; -- Given static expression or static range from a Static_Predicate list, -- gets expression value or low bound of range. function Hi_Val (N : Node_Id) return Uint; -- Given static expression or static range from a Static_Predicate list, -- gets expression value of high bound of range. function Membership_Entry (N : Node_Id) return RList; -- Given a single membership entry (range, value, or subtype), returns -- the corresponding range list. Raises Static_Error if not static. function Membership_Entries (N : Node_Id) return RList; -- Given an element on an alternatives list of a membership operation, -- returns the range list corresponding to this entry and all following -- entries (i.e. returns the "or" of this list of values). function Stat_Pred (Typ : Entity_Id) return RList; -- Given a type, if it has a static predicate, then return the predicate -- as a range list, otherwise raise Non_Static. ----------- -- "and" -- ----------- function "and" (Left, Right : RList) return RList is FEnt : REnt; -- First range of result SLeft : Nat := Left'First; -- Start of rest of left entries SRight : Nat := Right'First; -- Start of rest of right entries begin -- If either range is True, return the other if Is_True (Left) then return Right; elsif Is_True (Right) then return Left; end if; -- If either range is False, return False if Is_False (Left) or else Is_False (Right) then return False_Range; end if; -- Loop to remove entries at start that are disjoint, and thus -- just get discarded from the result entirely. loop -- If no operands left in either operand, result is false if SLeft > Left'Last or else SRight > Right'Last then return False_Range; -- Discard first left operand entry if disjoint with right elsif Left (SLeft).Hi < Right (SRight).Lo then SLeft := SLeft + 1; -- Discard first right operand entry if disjoint with left elsif Right (SRight).Hi < Left (SLeft).Lo then SRight := SRight + 1; -- Otherwise we have an overlapping entry else exit; end if; end loop; -- Now we have two non-null operands, and first entries overlap. -- The first entry in the result will be the overlapping part of -- these two entries. FEnt := REnt'(Lo => UI_Max (Left (SLeft).Lo, Right (SRight).Lo), Hi => UI_Min (Left (SLeft).Hi, Right (SRight).Hi)); -- Now we can remove the entry that ended at a lower value, since -- its contribution is entirely contained in Fent. if Left (SLeft).Hi <= Right (SRight).Hi then SLeft := SLeft + 1; else SRight := SRight + 1; end if; -- Compute result by concatenating this first entry with the "and" -- of the remaining parts of the left and right operands. Note that -- if either of these is empty, "and" will yield empty, so that we -- will end up with just Fent, which is what we want in that case. return FEnt & (Left (SLeft .. Left'Last) and Right (SRight .. Right'Last)); end "and"; ----------- -- "not" -- ----------- function "not" (Right : RList) return RList is begin -- Return True if False range if Is_False (Right) then return True_Range; end if; -- Return False if True range if Is_True (Right) then return False_Range; end if; -- Here if not trivial case declare Result : RList (1 .. Right'Length + 1); -- May need one more entry for gap at beginning and end Count : Nat := 0; -- Number of entries stored in Result begin -- Gap at start if Right (Right'First).Lo > TLo then Count := Count + 1; Result (Count) := REnt'(TLo, Right (Right'First).Lo - 1); end if; -- Gaps between ranges for J in Right'First .. Right'Last - 1 loop Count := Count + 1; Result (Count) := REnt'(Right (J).Hi + 1, Right (J + 1).Lo - 1); end loop; -- Gap at end if Right (Right'Last).Hi < THi then Count := Count + 1; Result (Count) := REnt'(Right (Right'Last).Hi + 1, THi); end if; return Result (1 .. Count); end; end "not"; ---------- -- "or" -- ---------- function "or" (Left, Right : RList) return RList is FEnt : REnt; -- First range of result SLeft : Nat := Left'First; -- Start of rest of left entries SRight : Nat := Right'First; -- Start of rest of right entries begin -- If either range is True, return True if Is_True (Left) or else Is_True (Right) then return True_Range; end if; -- If either range is False (empty), return the other if Is_False (Left) then return Right; elsif Is_False (Right) then return Left; end if; -- Initialize result first entry from left or right operand -- depending on which starts with the lower range. if Left (SLeft).Lo < Right (SRight).Lo then FEnt := Left (SLeft); SLeft := SLeft + 1; else FEnt := Right (SRight); SRight := SRight + 1; end if; -- This loop eats ranges from left and right operands that -- are contiguous with the first range we are gathering. loop -- Eat first entry in left operand if contiguous or -- overlapped by gathered first operand of result. if SLeft <= Left'Last and then Left (SLeft).Lo <= FEnt.Hi + 1 then FEnt.Hi := UI_Max (FEnt.Hi, Left (SLeft).Hi); SLeft := SLeft + 1; -- Eat first entry in right operand if contiguous or -- overlapped by gathered right operand of result. elsif SRight <= Right'Last and then Right (SRight).Lo <= FEnt.Hi + 1 then FEnt.Hi := UI_Max (FEnt.Hi, Right (SRight).Hi); SRight := SRight + 1; -- All done if no more entries to eat! else exit; end if; end loop; -- Obtain result as the first entry we just computed, concatenated -- to the "or" of the remaining results (if one operand is empty, -- this will just concatenate with the other return FEnt & (Left (SLeft .. Left'Last) or Right (SRight .. Right'Last)); end "or"; ----------------- -- Build_Range -- ----------------- function Build_Range (Lo, Hi : Uint) return Node_Id is Result : Node_Id; begin if Lo = Hi then return Build_Val (Hi); else Result := Make_Range (Loc, Low_Bound => Build_Val (Lo), High_Bound => Build_Val (Hi)); Set_Etype (Result, Btyp); Set_Analyzed (Result); return Result; end if; end Build_Range; --------------- -- Build_Val -- --------------- function Build_Val (V : Uint) return Node_Id is Result : Node_Id; begin if Is_Enumeration_Type (Typ) then Result := Get_Enum_Lit_From_Pos (Typ, V, Loc); else Result := Make_Integer_Literal (Loc, V); end if; Set_Etype (Result, Btyp); Set_Is_Static_Expression (Result); Set_Analyzed (Result); return Result; end Build_Val; --------------- -- Get_RList -- --------------- function Get_RList (Exp : Node_Id) return RList is Op : Node_Kind; Val : Uint; begin -- Static expression can only be true or false if Is_OK_Static_Expression (Exp) then -- For False if Expr_Value (Exp) = 0 then return False_Range; else return True_Range; end if; end if; -- Otherwise test node type Op := Nkind (Exp); case Op is -- And when N_Op_And | N_And_Then => return Get_RList (Left_Opnd (Exp)) and Get_RList (Right_Opnd (Exp)); -- Or when N_Op_Or | N_Or_Else => return Get_RList (Left_Opnd (Exp)) or Get_RList (Right_Opnd (Exp)); -- Not when N_Op_Not => return not Get_RList (Right_Opnd (Exp)); -- Comparisons of type with static value when N_Op_Compare => -- Type is left operand if Is_Type_Ref (Left_Opnd (Exp)) and then Is_OK_Static_Expression (Right_Opnd (Exp)) then Val := Expr_Value (Right_Opnd (Exp)); -- Typ is right operand elsif Is_Type_Ref (Right_Opnd (Exp)) and then Is_OK_Static_Expression (Left_Opnd (Exp)) then Val := Expr_Value (Left_Opnd (Exp)); -- Invert sense of comparison case Op is when N_Op_Gt => Op := N_Op_Lt; when N_Op_Lt => Op := N_Op_Gt; when N_Op_Ge => Op := N_Op_Le; when N_Op_Le => Op := N_Op_Ge; when others => null; end case; -- Other cases are non-static else raise Non_Static; end if; -- Construct range according to comparison operation case Op is when N_Op_Eq => return RList'(1 => REnt'(Val, Val)); when N_Op_Ge => return RList'(1 => REnt'(Val, BHi)); when N_Op_Gt => return RList'(1 => REnt'(Val + 1, BHi)); when N_Op_Le => return RList'(1 => REnt'(BLo, Val)); when N_Op_Lt => return RList'(1 => REnt'(BLo, Val - 1)); when N_Op_Ne => return RList'(REnt'(BLo, Val - 1), REnt'(Val + 1, BHi)); when others => raise Program_Error; end case; -- Membership (IN) when N_In => if not Is_Type_Ref (Left_Opnd (Exp)) then raise Non_Static; end if; if Present (Right_Opnd (Exp)) then return Membership_Entry (Right_Opnd (Exp)); else return Membership_Entries (First (Alternatives (Exp))); end if; -- Negative membership (NOT IN) when N_Not_In => if not Is_Type_Ref (Left_Opnd (Exp)) then raise Non_Static; end if; if Present (Right_Opnd (Exp)) then return not Membership_Entry (Right_Opnd (Exp)); else return not Membership_Entries (First (Alternatives (Exp))); end if; -- Function call, may be call to static predicate when N_Function_Call => if Is_Entity_Name (Name (Exp)) then declare Ent : constant Entity_Id := Entity (Name (Exp)); begin if Has_Predicates (Ent) then return Stat_Pred (Etype (First_Formal (Ent))); end if; end; end if; -- Other function call cases are non-static raise Non_Static; -- Qualified expression, dig out the expression when N_Qualified_Expression => return Get_RList (Expression (Exp)); -- Xor operator when N_Op_Xor => return (Get_RList (Left_Opnd (Exp)) and not Get_RList (Right_Opnd (Exp))) or (Get_RList (Right_Opnd (Exp)) and not Get_RList (Left_Opnd (Exp))); -- Any other node type is non-static when others => raise Non_Static; end case; end Get_RList; ------------ -- Hi_Val -- ------------ function Hi_Val (N : Node_Id) return Uint is begin if Is_Static_Expression (N) then return Expr_Value (N); else pragma Assert (Nkind (N) = N_Range); return Expr_Value (High_Bound (N)); end if; end Hi_Val; -------------- -- Is_False -- -------------- function Is_False (R : RList) return Boolean is begin return R'Length = 0; end Is_False; ------------- -- Is_True -- ------------- function Is_True (R : RList) return Boolean is begin return R'Length = 1 and then R (R'First).Lo = BLo and then R (R'First).Hi = BHi; end Is_True; ----------------- -- Is_Type_Ref -- ----------------- function Is_Type_Ref (N : Node_Id) return Boolean is begin return Nkind (N) = N_Identifier and then Chars (N) = Nam; end Is_Type_Ref; ------------ -- Lo_Val -- ------------ function Lo_Val (N : Node_Id) return Uint is begin if Is_Static_Expression (N) then return Expr_Value (N); else pragma Assert (Nkind (N) = N_Range); return Expr_Value (Low_Bound (N)); end if; end Lo_Val; ------------------------ -- Membership_Entries -- ------------------------ function Membership_Entries (N : Node_Id) return RList is begin if No (Next (N)) then return Membership_Entry (N); else return Membership_Entry (N) or Membership_Entries (Next (N)); end if; end Membership_Entries; ---------------------- -- Membership_Entry -- ---------------------- function Membership_Entry (N : Node_Id) return RList is Val : Uint; SLo : Uint; SHi : Uint; begin -- Range case if Nkind (N) = N_Range then if not Is_Static_Expression (Low_Bound (N)) or else not Is_Static_Expression (High_Bound (N)) then raise Non_Static; else SLo := Expr_Value (Low_Bound (N)); SHi := Expr_Value (High_Bound (N)); return RList'(1 => REnt'(SLo, SHi)); end if; -- Static expression case elsif Is_Static_Expression (N) then Val := Expr_Value (N); return RList'(1 => REnt'(Val, Val)); -- Identifier (other than static expression) case else pragma Assert (Nkind (N) = N_Identifier); -- Type case if Is_Type (Entity (N)) then -- If type has predicates, process them if Has_Predicates (Entity (N)) then return Stat_Pred (Entity (N)); -- For static subtype without predicates, get range elsif Is_Static_Subtype (Entity (N)) then SLo := Expr_Value (Type_Low_Bound (Entity (N))); SHi := Expr_Value (Type_High_Bound (Entity (N))); return RList'(1 => REnt'(SLo, SHi)); -- Any other type makes us non-static else raise Non_Static; end if; -- Any other kind of identifier in predicate (e.g. a non-static -- expression value) means this is not a static predicate. else raise Non_Static; end if; end if; end Membership_Entry; --------------- -- Stat_Pred -- --------------- function Stat_Pred (Typ : Entity_Id) return RList is begin -- Not static if type does not have static predicates if not Has_Predicates (Typ) or else No (Static_Predicate (Typ)) then raise Non_Static; end if; -- Otherwise we convert the predicate list to a range list declare Result : RList (1 .. List_Length (Static_Predicate (Typ))); P : Node_Id; begin P := First (Static_Predicate (Typ)); for J in Result'Range loop Result (J) := REnt'(Lo_Val (P), Hi_Val (P)); Next (P); end loop; return Result; end; end Stat_Pred; -- Start of processing for Build_Static_Predicate begin -- Now analyze the expression to see if it is a static predicate declare Ranges : constant RList := Get_RList (Expr); -- Range list from expression if it is static Plist : List_Id; begin -- Convert range list into a form for the static predicate. In the -- Ranges array, we just have raw ranges, these must be converted -- to properly typed and analyzed static expressions or range nodes. -- Note: here we limit ranges to the ranges of the subtype, so that -- a predicate is always false for values outside the subtype. That -- seems fine, such values are invalid anyway, and considering them -- to fail the predicate seems allowed and friendly, and furthermore -- simplifies processing for case statements and loops. Plist := New_List; for J in Ranges'Range loop declare Lo : Uint := Ranges (J).Lo; Hi : Uint := Ranges (J).Hi; begin -- Ignore completely out of range entry if Hi < TLo or else Lo > THi then null; -- Otherwise process entry else -- Adjust out of range value to subtype range if Lo < TLo then Lo := TLo; end if; if Hi > THi then Hi := THi; end if; -- Convert range into required form if Lo = Hi then Append_To (Plist, Build_Val (Lo)); else Append_To (Plist, Build_Range (Lo, Hi)); end if; end if; end; end loop; -- Processing was successful and all entries were static, so now we -- can store the result as the predicate list. Set_Static_Predicate (Typ, Plist); -- The processing for static predicates put the expression into -- canonical form as a series of ranges. It also eliminated -- duplicates and collapsed and combined ranges. We might as well -- replace the alternatives list of the right operand of the -- membership test with the static predicate list, which will -- usually be more efficient. declare New_Alts : constant List_Id := New_List; Old_Node : Node_Id; New_Node : Node_Id; begin Old_Node := First (Plist); while Present (Old_Node) loop New_Node := New_Copy (Old_Node); if Nkind (New_Node) = N_Range then Set_Low_Bound (New_Node, New_Copy (Low_Bound (Old_Node))); Set_High_Bound (New_Node, New_Copy (High_Bound (Old_Node))); end if; Append_To (New_Alts, New_Node); Next (Old_Node); end loop; -- If empty list, replace by False if Is_Empty_List (New_Alts) then Rewrite (Expr, New_Occurrence_Of (Standard_False, Loc)); -- Else replace by set membership test else Rewrite (Expr, Make_In (Loc, Left_Opnd => Make_Identifier (Loc, Nam), Right_Opnd => Empty, Alternatives => New_Alts)); -- Resolve new expression in function context Install_Formals (Predicate_Function (Typ)); Push_Scope (Predicate_Function (Typ)); Analyze_And_Resolve (Expr, Standard_Boolean); Pop_Scope; end if; end; end; -- If non-static, return doing nothing exception when Non_Static => return; end Build_Static_Predicate; ----------------------------------------- -- Check_Aspect_At_End_Of_Declarations -- ----------------------------------------- procedure Check_Aspect_At_End_Of_Declarations (ASN : Node_Id) is Ent : constant Entity_Id := Entity (ASN); Ident : constant Node_Id := Identifier (ASN); Freeze_Expr : constant Node_Id := Expression (ASN); -- Expression from call to Check_Aspect_At_Freeze_Point End_Decl_Expr : constant Node_Id := Entity (Ident); -- Expression to be analyzed at end of declarations T : constant Entity_Id := Etype (Freeze_Expr); -- Type required for preanalyze call A_Id : constant Aspect_Id := Get_Aspect_Id (Chars (Ident)); Err : Boolean; -- Set False if error -- On entry to this procedure, Entity (Ident) contains a copy of the -- original expression from the aspect, saved for this purpose, and -- but Expression (Ident) is a preanalyzed copy of the expression, -- preanalyzed just after the freeze point. begin -- Case of stream attributes, just have to compare entities if A_Id = Aspect_Input or else A_Id = Aspect_Output or else A_Id = Aspect_Read or else A_Id = Aspect_Write then Analyze (End_Decl_Expr); Err := Entity (End_Decl_Expr) /= Entity (Freeze_Expr); elsif A_Id = Aspect_Variable_Indexing or else A_Id = Aspect_Constant_Indexing or else A_Id = Aspect_Default_Iterator or else A_Id = Aspect_Iterator_Element then -- Make type unfrozen before analysis, to prevent spurious errors -- about late attributes. Set_Is_Frozen (Ent, False); Analyze (End_Decl_Expr); Analyze (Aspect_Rep_Item (ASN)); Set_Is_Frozen (Ent, True); -- If the end of declarations comes before any other freeze -- point, the Freeze_Expr is not analyzed: no check needed. Err := Analyzed (Freeze_Expr) and then not In_Instance and then Entity (End_Decl_Expr) /= Entity (Freeze_Expr); -- All other cases else -- In a generic context the aspect expressions have not been -- preanalyzed, so do it now. There are no conformance checks -- to perform in this case. if No (T) then Check_Aspect_At_Freeze_Point (ASN); return; -- The default values attributes may be defined in the private part, -- and the analysis of the expression may take place when only the -- partial view is visible. The expression must be scalar, so use -- the full view to resolve. elsif (A_Id = Aspect_Default_Value or else A_Id = Aspect_Default_Component_Value) and then Is_Private_Type (T) then Preanalyze_Spec_Expression (End_Decl_Expr, Full_View (T)); else Preanalyze_Spec_Expression (End_Decl_Expr, T); end if; Err := not Fully_Conformant_Expressions (End_Decl_Expr, Freeze_Expr); end if; -- Output error message if error if Err then Error_Msg_NE ("visibility of aspect for& changes after freeze point", ASN, Ent); Error_Msg_NE ("?info: & is frozen here, aspects evaluated at this point", Freeze_Node (Ent), Ent); end if; end Check_Aspect_At_End_Of_Declarations; ---------------------------------- -- Check_Aspect_At_Freeze_Point -- ---------------------------------- procedure Check_Aspect_At_Freeze_Point (ASN : Node_Id) is Ident : constant Node_Id := Identifier (ASN); -- Identifier (use Entity field to save expression) T : Entity_Id; -- Type required for preanalyze call A_Id : constant Aspect_Id := Get_Aspect_Id (Chars (Ident)); begin -- On entry to this procedure, Entity (Ident) contains a copy of the -- original expression from the aspect, saved for this purpose. -- On exit from this procedure Entity (Ident) is unchanged, still -- containing that copy, but Expression (Ident) is a preanalyzed copy -- of the expression, preanalyzed just after the freeze point. -- Make a copy of the expression to be preanalyed Set_Expression (ASN, New_Copy_Tree (Entity (Ident))); -- Find type for preanalyze call case A_Id is -- No_Aspect should be impossible when No_Aspect => raise Program_Error; -- Library unit aspects should be impossible (never delayed) when Library_Unit_Aspects => raise Program_Error; -- Aspects taking an optional boolean argument. Should be impossible -- since these are never delayed. when Boolean_Aspects => raise Program_Error; -- Test_Case aspect applies to entries and subprograms, hence should -- never be delayed. when Aspect_Test_Case => raise Program_Error; when Aspect_Attach_Handler => T := RTE (RE_Interrupt_ID); -- Default_Value is resolved with the type entity in question when Aspect_Default_Value => T := Entity (ASN); -- Default_Component_Value is resolved with the component type when Aspect_Default_Component_Value => T := Component_Type (Entity (ASN)); -- Aspects corresponding to attribute definition clauses when Aspect_Address => T := RTE (RE_Address); when Aspect_Bit_Order => T := RTE (RE_Bit_Order); when Aspect_CPU => T := RTE (RE_CPU_Range); when Aspect_Dispatching_Domain => T := RTE (RE_Dispatching_Domain); when Aspect_External_Tag => T := Standard_String; when Aspect_Priority | Aspect_Interrupt_Priority => T := Standard_Integer; when Aspect_Small => T := Universal_Real; -- For a simple storage pool, we have to retrieve the type of the -- pool object associated with the aspect's corresponding attribute -- definition clause. when Aspect_Simple_Storage_Pool => T := Etype (Expression (Aspect_Rep_Item (ASN))); when Aspect_Storage_Pool => T := Class_Wide_Type (RTE (RE_Root_Storage_Pool)); when Aspect_Alignment | Aspect_Component_Size | Aspect_Machine_Radix | Aspect_Object_Size | Aspect_Size | Aspect_Storage_Size | Aspect_Stream_Size | Aspect_Value_Size => T := Any_Integer; -- Stream attribute. Special case, the expression is just an entity -- that does not need any resolution, so just analyze. when Aspect_Input | Aspect_Output | Aspect_Read | Aspect_Write => Analyze (Expression (ASN)); return; -- Same for Iterator aspects, where the expression is a function -- name. Legality rules are checked separately. when Aspect_Constant_Indexing | Aspect_Default_Iterator | Aspect_Iterator_Element | Aspect_Implicit_Dereference | Aspect_Variable_Indexing => Analyze (Expression (ASN)); return; -- Suppress/Unsuppress/Synchronization/Warnings should not be delayed when Aspect_Suppress | Aspect_Unsuppress | Aspect_Synchronization | Aspect_Warnings => raise Program_Error; -- Pre/Post/Invariant/Predicate take boolean expressions when Aspect_Dynamic_Predicate | Aspect_Invariant | Aspect_Pre | Aspect_Precondition | Aspect_Post | Aspect_Postcondition | Aspect_Predicate | Aspect_Static_Predicate | Aspect_Type_Invariant => T := Standard_Boolean; when Aspect_Dimension | Aspect_Dimension_System => raise Program_Error; end case; -- Do the preanalyze call Preanalyze_Spec_Expression (Expression (ASN), T); end Check_Aspect_At_Freeze_Point; ----------------------------------- -- Check_Constant_Address_Clause -- ----------------------------------- procedure Check_Constant_Address_Clause (Expr : Node_Id; U_Ent : Entity_Id) is procedure Check_At_Constant_Address (Nod : Node_Id); -- Checks that the given node N represents a name whose 'Address is -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the -- address value is the same at the point of declaration of U_Ent and at -- the time of elaboration of the address clause. procedure Check_Expr_Constants (Nod : Node_Id); -- Checks that Nod meets the requirements for a constant address clause -- in the sense of the enclosing procedure. procedure Check_List_Constants (Lst : List_Id); -- Check that all elements of list Lst meet the requirements for a -- constant address clause in the sense of the enclosing procedure. ------------------------------- -- Check_At_Constant_Address -- ------------------------------- procedure Check_At_Constant_Address (Nod : Node_Id) is begin if Is_Entity_Name (Nod) then if Present (Address_Clause (Entity ((Nod)))) then Error_Msg_NE ("invalid address clause for initialized object &!", Nod, U_Ent); Error_Msg_NE ("address for& cannot" & " depend on another address clause! (RM 13.1(22))!", Nod, U_Ent); elsif In_Same_Source_Unit (Entity (Nod), U_Ent) and then Sloc (U_Ent) < Sloc (Entity (Nod)) then Error_Msg_NE ("invalid address clause for initialized object &!", Nod, U_Ent); Error_Msg_Node_2 := U_Ent; Error_Msg_NE ("\& must be defined before & (RM 13.1(22))!", Nod, Entity (Nod)); end if; elsif Nkind (Nod) = N_Selected_Component then declare T : constant Entity_Id := Etype (Prefix (Nod)); begin if (Is_Record_Type (T) and then Has_Discriminants (T)) or else (Is_Access_Type (T) and then Is_Record_Type (Designated_Type (T)) and then Has_Discriminants (Designated_Type (T))) then Error_Msg_NE ("invalid address clause for initialized object &!", Nod, U_Ent); Error_Msg_N ("\address cannot depend on component" & " of discriminated record (RM 13.1(22))!", Nod); else Check_At_Constant_Address (Prefix (Nod)); end if; end; elsif Nkind (Nod) = N_Indexed_Component then Check_At_Constant_Address (Prefix (Nod)); Check_List_Constants (Expressions (Nod)); else Check_Expr_Constants (Nod); end if; end Check_At_Constant_Address; -------------------------- -- Check_Expr_Constants -- -------------------------- procedure Check_Expr_Constants (Nod : Node_Id) is Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent); Ent : Entity_Id := Empty; begin if Nkind (Nod) in N_Has_Etype and then Etype (Nod) = Any_Type then return; end if; case Nkind (Nod) is when N_Empty | N_Error => return; when N_Identifier | N_Expanded_Name => Ent := Entity (Nod); -- We need to look at the original node if it is different -- from the node, since we may have rewritten things and -- substituted an identifier representing the rewrite. if Original_Node (Nod) /= Nod then Check_Expr_Constants (Original_Node (Nod)); -- If the node is an object declaration without initial -- value, some code has been expanded, and the expression -- is not constant, even if the constituents might be -- acceptable, as in A'Address + offset. if Ekind (Ent) = E_Variable and then Nkind (Declaration_Node (Ent)) = N_Object_Declaration and then No (Expression (Declaration_Node (Ent))) then Error_Msg_NE ("invalid address clause for initialized object &!", Nod, U_Ent); -- If entity is constant, it may be the result of expanding -- a check. We must verify that its declaration appears -- before the object in question, else we also reject the -- address clause. elsif Ekind (Ent) = E_Constant and then In_Same_Source_Unit (Ent, U_Ent) and then Sloc (Ent) > Loc_U_Ent then Error_Msg_NE ("invalid address clause for initialized object &!", Nod, U_Ent); end if; return; end if; -- Otherwise look at the identifier and see if it is OK if Ekind_In (Ent, E_Named_Integer, E_Named_Real) or else Is_Type (Ent) then return; elsif Ekind (Ent) = E_Constant or else Ekind (Ent) = E_In_Parameter then -- This is the case where we must have Ent defined before -- U_Ent. Clearly if they are in different units this -- requirement is met since the unit containing Ent is -- already processed. if not In_Same_Source_Unit (Ent, U_Ent) then return; -- Otherwise location of Ent must be before the location -- of U_Ent, that's what prior defined means. elsif Sloc (Ent) < Loc_U_Ent then return; else Error_Msg_NE ("invalid address clause for initialized object &!", Nod, U_Ent); Error_Msg_Node_2 := U_Ent; Error_Msg_NE ("\& must be defined before & (RM 13.1(22))!", Nod, Ent); end if; elsif Nkind (Original_Node (Nod)) = N_Function_Call then Check_Expr_Constants (Original_Node (Nod)); else Error_Msg_NE ("invalid address clause for initialized object &!", Nod, U_Ent); if Comes_From_Source (Ent) then Error_Msg_NE ("\reference to variable& not allowed" & " (RM 13.1(22))!", Nod, Ent); else Error_Msg_N ("non-static expression not allowed" & " (RM 13.1(22))!", Nod); end if; end if; when N_Integer_Literal => -- If this is a rewritten unchecked conversion, in a system -- where Address is an integer type, always use the base type -- for a literal value. This is user-friendly and prevents -- order-of-elaboration issues with instances of unchecked -- conversion. if Nkind (Original_Node (Nod)) = N_Function_Call then Set_Etype (Nod, Base_Type (Etype (Nod))); end if; when N_Real_Literal | N_String_Literal | N_Character_Literal => return; when N_Range => Check_Expr_Constants (Low_Bound (Nod)); Check_Expr_Constants (High_Bound (Nod)); when N_Explicit_Dereference => Check_Expr_Constants (Prefix (Nod)); when N_Indexed_Component => Check_Expr_Constants (Prefix (Nod)); Check_List_Constants (Expressions (Nod)); when N_Slice => Check_Expr_Constants (Prefix (Nod)); Check_Expr_Constants (Discrete_Range (Nod)); when N_Selected_Component => Check_Expr_Constants (Prefix (Nod)); when N_Attribute_Reference => if Attribute_Name (Nod) = Name_Address or else Attribute_Name (Nod) = Name_Access or else Attribute_Name (Nod) = Name_Unchecked_Access or else Attribute_Name (Nod) = Name_Unrestricted_Access then Check_At_Constant_Address (Prefix (Nod)); else Check_Expr_Constants (Prefix (Nod)); Check_List_Constants (Expressions (Nod)); end if; when N_Aggregate => Check_List_Constants (Component_Associations (Nod)); Check_List_Constants (Expressions (Nod)); when N_Component_Association => Check_Expr_Constants (Expression (Nod)); when N_Extension_Aggregate => Check_Expr_Constants (Ancestor_Part (Nod)); Check_List_Constants (Component_Associations (Nod)); Check_List_Constants (Expressions (Nod)); when N_Null => return; when N_Binary_Op | N_Short_Circuit | N_Membership_Test => Check_Expr_Constants (Left_Opnd (Nod)); Check_Expr_Constants (Right_Opnd (Nod)); when N_Unary_Op => Check_Expr_Constants (Right_Opnd (Nod)); when N_Type_Conversion | N_Qualified_Expression | N_Allocator => Check_Expr_Constants (Expression (Nod)); when N_Unchecked_Type_Conversion => Check_Expr_Constants (Expression (Nod)); -- If this is a rewritten unchecked conversion, subtypes in -- this node are those created within the instance. To avoid -- order of elaboration issues, replace them with their base -- types. Note that address clauses can cause order of -- elaboration problems because they are elaborated by the -- back-end at the point of definition, and may mention -- entities declared in between (as long as everything is -- static). It is user-friendly to allow unchecked conversions -- in this context. if Nkind (Original_Node (Nod)) = N_Function_Call then Set_Etype (Expression (Nod), Base_Type (Etype (Expression (Nod)))); Set_Etype (Nod, Base_Type (Etype (Nod))); end if; when N_Function_Call => if not Is_Pure (Entity (Name (Nod))) then Error_Msg_NE ("invalid address clause for initialized object &!", Nod, U_Ent); Error_Msg_NE ("\function & is not pure (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, Name_uTag), Position => Make_Integer_Literal (Loc, Uint_0), First_Bit => Make_Integer_Literal (Loc, 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 RM_Size (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; if Error_Msg_Uint_1 > 0 then Error_Msg_NE ("?^-bit gap before component&", Component_Name (Component_Clause (CEnt)), CEnt); end if; Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt); end loop; -- Process variant parts recursively if present 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; -- Start of processing for Record_Hole_Check begin declare Sbit : Uint; begin if Is_Tagged_Type (Rectype) then Sbit := UI_From_Int (System_Address_Size); else Sbit := Uint_0; end if; 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; -- 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; end Check_Record_Representation_Clause; ---------------- -- Check_Size -- ---------------- procedure Check_Size (N : Node_Id; T : Entity_Id; Siz : Uint; Biased : out Boolean) is UT : constant Entity_Id := Underlying_Type (T); M : Uint; begin Biased := False; -- Dismiss cases for generic types or types with previous errors if No (UT) or else UT = Any_Type or else Is_Generic_Type (UT) or else Is_Generic_Type (Root_Type (UT)) then return; -- Check case of bit packed array elsif Is_Array_Type (UT) and then Known_Static_Component_Size (UT) and then Is_Bit_Packed_Array (UT) then declare Asiz : Uint; Indx : Node_Id; Ityp : Entity_Id; begin Asiz := Component_Size (UT); Indx := First_Index (UT); loop Ityp := Etype (Indx); -- If non-static bound, then we are not in the business of -- trying to check the length, and indeed an error will be -- issued elsewhere, since sizes of non-static array types -- cannot be set implicitly or explicitly. if not Is_Static_Subtype (Ityp) then return; end if; -- Otherwise accumulate next dimension Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) - Expr_Value (Type_Low_Bound (Ityp)) + Uint_1); Next_Index (Indx); exit when No (Indx); end loop; if Asiz <= Siz then return; else Error_Msg_Uint_1 := Asiz; Error_Msg_NE ("size for& too small, minimum allowed is ^", N, T); Set_Esize (T, Asiz); Set_RM_Size (T, Asiz); end if; end; -- All other composite types are ignored elsif Is_Composite_Type (UT) then return; -- For fixed-point types, don't check minimum if type is not frozen, -- since we don't know all the characteristics of the type that can -- affect the size (e.g. a specified small) till freeze time. elsif Is_Fixed_Point_Type (UT) and then not Is_Frozen (UT) then null; -- Cases for which a minimum check is required else -- Ignore if specified size is correct for the type if Known_Esize (UT) and then Siz = Esize (UT) then return; end if; -- Otherwise get minimum size M := UI_From_Int (Minimum_Size (UT)); if Siz < M then -- Size is less than minimum size, but one possibility remains -- that we can manage with the new size if we bias the type. M := UI_From_Int (Minimum_Size (UT, Biased => True)); if Siz < M then Error_Msg_Uint_1 := M; Error_Msg_NE ("size for& too small, minimum allowed is ^", N, T); Set_Esize (T, M); Set_RM_Size (T, M); else Biased := True; end if; end if; end if; end Check_Size; ------------------------- -- Get_Alignment_Value -- ------------------------- function Get_Alignment_Value (Expr : Node_Id) return Uint is Align : constant Uint := Static_Integer (Expr); begin if Align = No_Uint then return No_Uint; elsif Align <= 0 then Error_Msg_N ("alignment value must be positive", Expr); return No_Uint; else for J in Int range 0 .. 64 loop declare M : constant Uint := Uint_2 ** J; begin exit when M = Align; if M > Align then Error_Msg_N ("alignment value must be power of 2", Expr); return No_Uint; end if; end; end loop; return Align; end if; end Get_Alignment_Value; ---------------- -- Initialize -- ---------------- procedure Initialize is begin Address_Clause_Checks.Init; Independence_Checks.Init; Unchecked_Conversions.Init; end Initialize; ------------------------- -- Is_Operational_Item -- ------------------------- function Is_Operational_Item (N : Node_Id) return Boolean is begin if Nkind (N) /= N_Attribute_Definition_Clause then return False; else declare Id : constant Attribute_Id := Get_Attribute_Id (Chars (N)); begin return Id = Attribute_Input or else Id = Attribute_Output or else Id = Attribute_Read or else Id = Attribute_Write or else Id = Attribute_External_Tag; end; end if; end Is_Operational_Item; ------------------ -- Minimum_Size -- ------------------ function Minimum_Size (T : Entity_Id; Biased : Boolean := False) return Nat is Lo : Uint := No_Uint; Hi : Uint := No_Uint; LoR : Ureal := No_Ureal; HiR : Ureal := No_Ureal; LoSet : Boolean := False; HiSet : Boolean := False; B : Uint; S : Nat; Ancest : Entity_Id; R_Typ : constant Entity_Id := Root_Type (T); begin -- If bad type, return 0 if T = Any_Type then return 0; -- For generic types, just return zero. There cannot be any legitimate -- need to know such a size, but this routine may be called with a -- generic type as part of normal processing. elsif Is_Generic_Type (R_Typ) or else R_Typ = Any_Type then return 0; -- Access types. Normally an access type cannot have a size smaller -- than the size of System.Address. The exception is on VMS, where -- we have short and long addresses, and it is possible for an access -- type to have a short address size (and thus be less than the size -- of System.Address itself). We simply skip the check for VMS, and -- leave it to the back end to do the check. elsif Is_Access_Type (T) then if OpenVMS_On_Target then return 0; else return System_Address_Size; end if; -- Floating-point types elsif Is_Floating_Point_Type (T) then return UI_To_Int (Esize (R_Typ)); -- Discrete types elsif Is_Discrete_Type (T) then -- The following loop is looking for the nearest compile time known -- bounds following the ancestor subtype chain. The idea is to find -- the most restrictive known bounds information. Ancest := T; loop if Ancest = Any_Type or else Etype (Ancest) = Any_Type then return 0; end if; if not LoSet then if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then Lo := Expr_Rep_Value (Type_Low_Bound (Ancest)); LoSet := True; exit when HiSet; end if; end if; if not HiSet then if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then Hi := Expr_Rep_Value (Type_High_Bound (Ancest)); HiSet := True; exit when LoSet; end if; end if; Ancest := Ancestor_Subtype (Ancest); if No (Ancest) then Ancest := Base_Type (T); if Is_Generic_Type (Ancest) then return 0; end if; end if; end loop; -- Fixed-point types. We can't simply use Expr_Value to get the -- Corresponding_Integer_Value values of the bounds, since these do not -- get set till the type is frozen, and this routine can be called -- before the type is frozen. Similarly the test for bounds being static -- needs to include the case where we have unanalyzed real literals for -- the same reason. elsif Is_Fixed_Point_Type (T) then -- The following loop is looking for the nearest compile time known -- bounds following the ancestor subtype chain. The idea is to find -- the most restrictive known bounds information. Ancest := T; loop if Ancest = Any_Type or else Etype (Ancest) = Any_Type then return 0; end if; -- Note: In the following two tests for LoSet and HiSet, it may -- seem redundant to test for N_Real_Literal here since normally -- one would assume that the test for the value being known at -- compile time includes this case. However, there is a glitch. -- If the real literal comes from folding a non-static expression, -- then we don't consider any non- static expression to be known -- at compile time if we are in configurable run time mode (needed -- in some cases to give a clearer definition of what is and what -- is not accepted). So the test is indeed needed. Without it, we -- would set neither Lo_Set nor Hi_Set and get an infinite loop. if not LoSet then if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal or else Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then LoR := Expr_Value_R (Type_Low_Bound (Ancest)); LoSet := True; exit when HiSet; end if; end if; if not HiSet then if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal or else Compile_Time_Known_Value (Type_High_Bound (Ancest)) then HiR := Expr_Value_R (Type_High_Bound (Ancest)); HiSet := True; exit when LoSet; end if; end if; Ancest := Ancestor_Subtype (Ancest); if No (Ancest) then Ancest := Base_Type (T); if Is_Generic_Type (Ancest) then return 0; end if; end if; end loop; Lo := UR_To_Uint (LoR / Small_Value (T)); Hi := UR_To_Uint (HiR / Small_Value (T)); -- No other types allowed else raise Program_Error; end if; -- Fall through with Hi and Lo set. Deal with biased case if (Biased and then not Is_Fixed_Point_Type (T) and then not (Is_Enumeration_Type (T) and then Has_Non_Standard_Rep (T))) or else Has_Biased_Representation (T) then Hi := Hi - Lo; Lo := Uint_0; end if; -- Signed case. Note that we consider types like range 1 .. -1 to be -- signed for the purpose of computing the size, since the bounds have -- to be accommodated in the base type. if Lo < 0 or else Hi < 0 then S := 1; B := Uint_1; -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1)) -- Note that we accommodate the case where the bounds cross. This -- can happen either because of the way the bounds are declared -- or because of the algorithm in Freeze_Fixed_Point_Type. while Lo < -B or else Hi < -B or else Lo >= B or else Hi >= B loop B := Uint_2 ** S; S := S + 1; end loop; -- Unsigned case else -- If both bounds are positive, make sure that both are represen- -- table in the case where the bounds are crossed. This can happen -- either because of the way the bounds are declared, or because of -- the algorithm in Freeze_Fixed_Point_Type. if Lo > Hi then Hi := Lo; end if; -- S = size, (can accommodate 0 .. (2**size - 1)) S := 0; while Hi >= Uint_2 ** S loop S := S + 1; end loop; end if; return S; end Minimum_Size; --------------------------- -- New_Stream_Subprogram -- --------------------------- procedure New_Stream_Subprogram (N : Node_Id; Ent : Entity_Id; Subp : Entity_Id; Nam : TSS_Name_Type) is Loc : constant Source_Ptr := Sloc (N); Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam); Subp_Id : Entity_Id; Subp_Decl : Node_Id; F : Entity_Id; Etyp : Entity_Id; Defer_Declaration : constant Boolean := Is_Tagged_Type (Ent) or else Is_Private_Type (Ent); -- For a tagged type, there is a declaration for each stream attribute -- at the freeze point, and we must generate only a completion of this -- declaration. We do the same for private types, because the full view -- might be tagged. Otherwise we generate a declaration at the point of -- the attribute definition clause. function Build_Spec return Node_Id; -- Used for declaration and renaming declaration, so that this is -- treated as a renaming_as_body. ---------------- -- Build_Spec -- ---------------- function Build_Spec return Node_Id is Out_P : constant Boolean := (Nam = TSS_Stream_Read); Formals : List_Id; Spec : Node_Id; T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc); begin Subp_Id := Make_Defining_Identifier (Loc, Sname); -- S : access Root_Stream_Type'Class Formals := New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => Make_Defining_Identifier (Loc, Name_S), Parameter_Type => Make_Access_Definition (Loc, Subtype_Mark => New_Reference_To ( Designated_Type (Etype (F)), Loc)))); if Nam = TSS_Stream_Input then Spec := Make_Function_Specification (Loc, Defining_Unit_Name => Subp_Id, Parameter_Specifications => Formals, Result_Definition => T_Ref); else -- V : [out] T Append_To (Formals, Make_Parameter_Specification (Loc, Defining_Identifier => Make_Defining_Identifier (Loc, Name_V), Out_Present => Out_P, Parameter_Type => T_Ref)); Spec := Make_Procedure_Specification (Loc, Defining_Unit_Name => Subp_Id, Parameter_Specifications => Formals); end if; return Spec; end Build_Spec; -- Start of processing for New_Stream_Subprogram begin F := First_Formal (Subp); if Ekind (Subp) = E_Procedure then Etyp := Etype (Next_Formal (F)); else Etyp := Etype (Subp); end if; -- Prepare subprogram declaration and insert it as an action on the -- clause node. The visibility for this entity is used to test for -- visibility of the attribute definition clause (in the sense of -- 8.3(23) as amended by AI-195). if not Defer_Declaration then Subp_Decl := Make_Subprogram_Declaration (Loc, Specification => Build_Spec); -- For a tagged type, there is always a visible declaration for each -- stream TSS (it is a predefined primitive operation), and the -- completion of this declaration occurs at the freeze point, which is -- not always visible at places where the attribute definition clause is -- visible. So, we create a dummy entity here for the purpose of -- tracking the visibility of the attribute definition clause itself. else Subp_Id := Make_Defining_Identifier (Loc, New_External_Name (Sname, 'V')); Subp_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Subp_Id, Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc)); end if; Insert_Action (N, Subp_Decl); Set_Entity (N, Subp_Id); Subp_Decl := Make_Subprogram_Renaming_Declaration (Loc, Specification => Build_Spec, Name => New_Reference_To (Subp, Loc)); if Defer_Declaration then Set_TSS (Base_Type (Ent), Subp_Id); else Insert_Action (N, Subp_Decl); Copy_TSS (Subp_Id, Base_Type (Ent)); end if; end New_Stream_Subprogram; ------------------------ -- Rep_Item_Too_Early -- ------------------------ function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is begin -- Cannot apply non-operational rep items to generic types if Is_Operational_Item (N) then return False; elsif Is_Type (T) and then Is_Generic_Type (Root_Type (T)) then Error_Msg_N ("representation item not allowed for generic type", N); return True; end if; -- Otherwise check for incomplete type if Is_Incomplete_Or_Private_Type (T) and then No (Underlying_Type (T)) and then (Nkind (N) /= N_Pragma or else Get_Pragma_Id (N) /= Pragma_Import) then Error_Msg_N ("representation item must be after full type declaration", N); return True; -- If the type has incomplete components, a representation clause is -- illegal but stream attributes and Convention pragmas are correct. elsif Has_Private_Component (T) then if Nkind (N) = N_Pragma then return False; else Error_Msg_N ("representation item must appear after type is fully defined", N); return True; end if; else return False; end if; end Rep_Item_Too_Early; ----------------------- -- Rep_Item_Too_Late -- ----------------------- function Rep_Item_Too_Late (T : Entity_Id; N : Node_Id; FOnly : Boolean := False) return Boolean is S : Entity_Id; Parent_Type : Entity_Id; procedure Too_Late; -- Output the too late message. Note that this is not considered a -- serious error, since the effect is simply that we ignore the -- representation clause in this case. -------------- -- Too_Late -- -------------- procedure Too_Late is begin Error_Msg_N ("|representation item appears too late!", N); end Too_Late; -- Start of processing for Rep_Item_Too_Late begin -- First make sure entity is not frozen (RM 13.1(9)) if Is_Frozen (T) -- Exclude imported types, which may be frozen if they appear in a -- representation clause for a local type. and then not From_With_Type (T) -- Exclude generated entitiesa (not coming from source). The common -- case is when we generate a renaming which prematurely freezes the -- renamed internal entity, but we still want to be able to set copies -- of attribute values such as Size/Alignment. and then Comes_From_Source (T) then Too_Late; S := First_Subtype (T); if Present (Freeze_Node (S)) then Error_Msg_NE ("?no more representation items for }", Freeze_Node (S), S); end if; return True; -- Check for case of non-tagged derived type whose parent either has -- primitive operations, or is a by reference type (RM 13.1(10)). elsif Is_Type (T) and then not FOnly and then Is_Derived_Type (T) and then not Is_Tagged_Type (T) then Parent_Type := Etype (Base_Type (T)); if Has_Primitive_Operations (Parent_Type) then Too_Late; Error_Msg_NE ("primitive operations already defined for&!", N, Parent_Type); return True; elsif Is_By_Reference_Type (Parent_Type) then Too_Late; Error_Msg_NE ("parent type & is a by reference type!", N, Parent_Type); return True; end if; end if; -- No error, link item into head of chain of rep items for the entity, -- but avoid chaining if we have an overloadable entity, and the pragma -- is one that can apply to multiple overloaded entities. if Is_Overloadable (T) and then Nkind (N) = N_Pragma then declare Pname : constant Name_Id := Pragma_Name (N); begin if Pname = Name_Convention or else Pname = Name_Import or else Pname = Name_Export or else Pname = Name_External or else Pname = Name_Interface then return False; end if; end; end if; Record_Rep_Item (T, N); return False; end Rep_Item_Too_Late; ------------------------------------- -- Replace_Type_References_Generic -- ------------------------------------- procedure Replace_Type_References_Generic (N : Node_Id; TName : Name_Id) is function Replace_Node (N : Node_Id) return Traverse_Result; -- Processes a single node in the traversal procedure below, checking -- if node N should be replaced, and if so, doing the replacement. procedure Replace_Type_Refs is new Traverse_Proc (Replace_Node); -- This instantiation provides the body of Replace_Type_References ------------------ -- Replace_Node -- ------------------ function Replace_Node (N : Node_Id) return Traverse_Result is S : Entity_Id; P : Node_Id; begin -- Case of identifier if Nkind (N) = N_Identifier then -- If not the type name, all done with this node if Chars (N) /= TName then return Skip; -- Otherwise do the replacement and we are done with this node else Replace_Type_Reference (N); return Skip; end if; -- Case of selected component (which is what a qualification -- looks like in the unanalyzed tree, which is what we have. elsif Nkind (N) = N_Selected_Component then -- If selector name is not our type, keeping going (we might -- still have an occurrence of the type in the prefix). if Nkind (Selector_Name (N)) /= N_Identifier or else Chars (Selector_Name (N)) /= TName then return OK; -- Selector name is our type, check qualification else -- Loop through scopes and prefixes, doing comparison S := Current_Scope; P := Prefix (N); loop -- Continue if no more scopes or scope with no name if No (S) or else Nkind (S) not in N_Has_Chars then return OK; end if; -- Do replace if prefix is an identifier matching the -- scope that we are currently looking at. if Nkind (P) = N_Identifier and then Chars (P) = Chars (S) then Replace_Type_Reference (N); return Skip; end if; -- Go check scope above us if prefix is itself of the -- form of a selected component, whose selector matches -- the scope we are currently looking at. if Nkind (P) = N_Selected_Component and then Nkind (Selector_Name (P)) = N_Identifier and then Chars (Selector_Name (P)) = Chars (S) then S := Scope (S); P := Prefix (P); -- For anything else, we don't have a match, so keep on -- going, there are still some weird cases where we may -- still have a replacement within the prefix. else return OK; end if; end loop; end if; -- Continue for any other node kind else return OK; end if; end Replace_Node; begin Replace_Type_Refs (N); end Replace_Type_References_Generic; ------------------------- -- Same_Representation -- ------------------------- function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is T1 : constant Entity_Id := Underlying_Type (Typ1); T2 : constant Entity_Id := Underlying_Type (Typ2); begin -- A quick check, if base types are the same, then we definitely have -- the same representation, because the subtype specific representation -- attributes (Size and Alignment) do not affect representation from -- the point of view of this test. if Base_Type (T1) = Base_Type (T2) then return True; elsif Is_Private_Type (Base_Type (T2)) and then Base_Type (T1) = Full_View (Base_Type (T2)) then return True; end if; -- Tagged types never have differing representations if Is_Tagged_Type (T1) then return True; end if; -- Representations are definitely different if conventions differ if Convention (T1) /= Convention (T2) then return False; end if; -- Representations are different if component alignments differ if (Is_Record_Type (T1) or else Is_Array_Type (T1)) and then (Is_Record_Type (T2) or else Is_Array_Type (T2)) and then Component_Alignment (T1) /= Component_Alignment (T2) then return False; end if; -- For arrays, the only real issue is component size. If we know the -- component size for both arrays, and it is the same, then that's -- good enough to know we don't have a change of representation. if Is_Array_Type (T1) then if Known_Component_Size (T1) and then Known_Component_Size (T2) and then Component_Size (T1) = Component_Size (T2) then if VM_Target = No_VM then return True; -- In VM targets the representation of arrays with aliased -- components differs from arrays with non-aliased components else return Has_Aliased_Components (Base_Type (T1)) = Has_Aliased_Components (Base_Type (T2)); end if; end if; end if; -- Types definitely have same representation if neither has non-standard -- representation since default representations are always consistent. -- If only one has non-standard representation, and the other does not, -- then we consider that they do not have the same representation. They -- might, but there is no way of telling early enough. if Has_Non_Standard_Rep (T1) then if not Has_Non_Standard_Rep (T2) then return False; end if; else return not Has_Non_Standard_Rep (T2); end if; -- Here the two types both have non-standard representation, and we need -- to determine if they have the same non-standard representation. -- For arrays, we simply need to test if the component sizes are the -- same. Pragma Pack is reflected in modified component sizes, so this -- check also deals with pragma Pack. if Is_Array_Type (T1) then return Component_Size (T1) = Component_Size (T2); -- Tagged types always have the same representation, because it is not -- possible to specify different representations for common fields. elsif Is_Tagged_Type (T1) then return True; -- Case of record types elsif Is_Record_Type (T1) then -- Packed status must conform if Is_Packed (T1) /= Is_Packed (T2) then return False; -- Otherwise we must check components. Typ2 maybe a constrained -- subtype with fewer components, so we compare the components -- of the base types. else Record_Case : declare CD1, CD2 : Entity_Id; function Same_Rep return Boolean; -- CD1 and CD2 are either components or discriminants. This -- function tests whether the two have the same representation -------------- -- Same_Rep -- -------------- function Same_Rep return Boolean is begin if No (Component_Clause (CD1)) then return No (Component_Clause (CD2)); else return Present (Component_Clause (CD2)) and then Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2) and then Esize (CD1) = Esize (CD2); end if; end Same_Rep; -- Start of processing for Record_Case begin if Has_Discriminants (T1) then CD1 := First_Discriminant (T1); CD2 := First_Discriminant (T2); -- The number of discriminants may be different if the -- derived type has fewer (constrained by values). The -- invisible discriminants retain the representation of -- the original, so the discrepancy does not per se -- indicate a different representation. while Present (CD1) and then Present (CD2) loop if not Same_Rep then return False; else Next_Discriminant (CD1); Next_Discriminant (CD2); end if; end loop; end if; CD1 := First_Component (Underlying_Type (Base_Type (T1))); CD2 := First_Component (Underlying_Type (Base_Type (T2))); while Present (CD1) loop if not Same_Rep then return False; else Next_Component (CD1); Next_Component (CD2); end if; end loop; return True; end Record_Case; end if; -- For enumeration types, we must check each literal to see if the -- representation is the same. Note that we do not permit enumeration -- representation clauses for Character and Wide_Character, so these -- cases were already dealt with. elsif Is_Enumeration_Type (T1) then Enumeration_Case : declare L1, L2 : Entity_Id; begin L1 := First_Literal (T1); L2 := First_Literal (T2); while Present (L1) loop if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then return False; else Next_Literal (L1); Next_Literal (L2); end if; end loop; return True; end Enumeration_Case; -- Any other types have the same representation for these purposes else return True; end if; end Same_Representation; ---------------- -- Set_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 -- -------------------- procedure Set_Enum_Esize (T : Entity_Id) is Lo : Uint; Hi : Uint; Sz : Nat; begin Init_Alignment (T); -- Find the minimum standard size (8,16,32,64) that fits Lo := Enumeration_Rep (Entity (Type_Low_Bound (T))); Hi := Enumeration_Rep (Entity (Type_High_Bound (T))); if Lo < 0 then if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then Sz := Standard_Character_Size; -- May be > 8 on some targets elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then Sz := 16; elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then Sz := 32; else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63); Sz := 64; end if; else if Hi < Uint_2**08 then Sz := Standard_Character_Size; -- May be > 8 on some targets elsif Hi < Uint_2**16 then Sz := 16; elsif Hi < Uint_2**32 then Sz := 32; else pragma Assert (Hi < Uint_2**63); Sz := 64; end if; end if; -- That minimum is the proper size unless we have a foreign convention -- and the size required is 32 or less, in which case we bump the size -- up to 32. This is required for C and C++ and seems reasonable for -- all other foreign conventions. if Has_Foreign_Convention (T) and then Esize (T) < Standard_Integer_Size then Init_Esize (T, Standard_Integer_Size); else Init_Esize (T, Sz); end if; end Set_Enum_Esize; ------------------------------ -- Validate_Address_Clauses -- ------------------------------ procedure Validate_Address_Clauses is begin for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop declare ACCR : Address_Clause_Check_Record renames Address_Clause_Checks.Table (J); Expr : Node_Id; X_Alignment : Uint; Y_Alignment : Uint; X_Size : Uint; Y_Size : Uint; begin -- Skip processing of this entry if warning already posted if not Address_Warning_Posted (ACCR.N) then Expr := Original_Node (Expression (ACCR.N)); -- Get alignments X_Alignment := Alignment (ACCR.X); Y_Alignment := Alignment (ACCR.Y); -- Similarly obtain sizes X_Size := Esize (ACCR.X); Y_Size := Esize (ACCR.Y); -- Check for large object overlaying smaller one if Y_Size > Uint_0 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 ("\?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_Uint_1 := Y_Size; Error_Msg_NE ("\?size of & is ^", ACCR.N, ACCR.Y); -- Check for inadequate alignment, both of the base object -- and of the offset, if any. -- 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 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 " & "with alignment", ACCR.N, ACCR.X); Error_Msg_N ("\?program execution may be erroneous (RM 13.3(27))", ACCR.N); Error_Msg_Uint_1 := X_Alignment; Error_Msg_NE ("\?alignment of & is ^", ACCR.N, ACCR.X); Error_Msg_Uint_1 := Y_Alignment; 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 -- ----------------------------------- procedure Validate_Unchecked_Conversion (N : Node_Id; Act_Unit : Entity_Id) is Source : Entity_Id; Target : Entity_Id; Vnode : Node_Id; begin -- Obtain source and target types. Note that we call Ancestor_Subtype -- here because the processing for generic instantiation always makes -- subtypes, and we want the original frozen actual types. -- If we are dealing with private types, then do the check on their -- fully declared counterparts if the full declarations have been -- encountered (they don't have to be visible, but they must exist!) Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit))); if Is_Private_Type (Source) and then Present (Underlying_Type (Source)) then Source := Underlying_Type (Source); end if; Target := Ancestor_Subtype (Etype (Act_Unit)); -- If either type is generic, the instantiation happens within a generic -- unit, and there is nothing to check. The proper check will happen -- when the enclosing generic is instantiated. if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then return; end if; if Is_Private_Type (Target) and then Present (Underlying_Type (Target)) then Target := Underlying_Type (Target); end if; -- Source may be unconstrained array, but not target if Is_Array_Type (Target) and then not Is_Constrained (Target) then Error_Msg_N ("unchecked conversion to unconstrained array not allowed", N); return; end if; -- Warn if conversion between two different convention pointers if Is_Access_Type (Target) and then Is_Access_Type (Source) and then Convention (Target) /= Convention (Source) and then Warn_On_Unchecked_Conversion then -- Give warnings for subprogram pointers only on most targets. The -- exception is VMS, where data pointers can have different lengths -- depending on the pointer convention. if Is_Access_Subprogram_Type (Target) or else Is_Access_Subprogram_Type (Source) or else OpenVMS_On_Target then Error_Msg_N ("?conversion between pointers with different conventions!", N); end if; end if; -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a -- warning when compiling GNAT-related sources. if Warn_On_Unchecked_Conversion and then not In_Predefined_Unit (N) and then RTU_Loaded (Ada_Calendar) and then (Chars (Source) = Name_Time or else Chars (Target) = Name_Time) then -- If Ada.Calendar is loaded and the name of one of the operands is -- Time, there is a good chance that this is Ada.Calendar.Time. declare Calendar_Time : constant Entity_Id := Full_View (RTE (RO_CA_Time)); begin pragma Assert (Present (Calendar_Time)); if Source = Calendar_Time or else Target = Calendar_Time then Error_Msg_N ("?representation of 'Time values may change between " & "'G'N'A'T versions", N); end if; end; end if; -- Make entry in unchecked conversion table for later processing by -- Validate_Unchecked_Conversions, which will check sizes and alignments -- (using values set by the back-end where possible). This is only done -- if the appropriate warning is active. if Warn_On_Unchecked_Conversion then Unchecked_Conversions.Append (New_Val => UC_Entry' (Eloc => Sloc (N), Source => Source, Target => Target)); -- If both sizes are known statically now, then back end annotation -- is not required to do a proper check but if either size is not -- known statically, then we need the annotation. if Known_Static_RM_Size (Source) and then Known_Static_RM_Size (Target) then null; else Back_Annotate_Rep_Info := True; end if; end if; -- If unchecked conversion to access type, and access type is declared -- in the same unit as the unchecked conversion, then set the flag -- No_Strict_Aliasing (no strict aliasing is implicit here) if Is_Access_Type (Target) and then In_Same_Source_Unit (Target, N) then Set_No_Strict_Aliasing (Implementation_Base_Type (Target)); end if; -- Generate N_Validate_Unchecked_Conversion node for back end in case -- the back end needs to perform special validation checks. -- Shouldn't this be in Exp_Ch13, since the check only gets done if we -- have full expansion and the back end is called ??? Vnode := Make_Validate_Unchecked_Conversion (Sloc (N)); Set_Source_Type (Vnode, Source); Set_Target_Type (Vnode, Target); -- If the unchecked conversion node is in a list, just insert before it. -- If not we have some strange case, not worth bothering about. if Is_List_Member (N) then Insert_After (N, Vnode); end if; end Validate_Unchecked_Conversion; ------------------------------------ -- Validate_Unchecked_Conversions -- ------------------------------------ procedure Validate_Unchecked_Conversions is begin for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop declare T : UC_Entry renames Unchecked_Conversions.Table (N); Eloc : constant Source_Ptr := T.Eloc; Source : constant Entity_Id := T.Source; Target : constant Entity_Id := T.Target; Source_Siz : Uint; Target_Siz : Uint; begin -- This validation check, which warns if we have unequal sizes for -- unchecked conversion, and thus potentially implementation -- dependent semantics, is one of the few occasions on which we -- use the official RM size instead of Esize. See description in -- Einfo "Handling of Type'Size Values" for details. if Serious_Errors_Detected = 0 and then Known_Static_RM_Size (Source) and then Known_Static_RM_Size (Target) -- Don't do the check if warnings off for either type, note the -- deliberate use of OR here instead of OR ELSE to get the flag -- Warnings_Off_Used set for both types if appropriate. and then not (Has_Warnings_Off (Source) or Has_Warnings_Off (Target)) then Source_Siz := RM_Size (Source); Target_Siz := RM_Size (Target); if Source_Siz /= Target_Siz then Error_Msg ("?types for unchecked conversion have different sizes!", Eloc); if All_Errors_Mode then Error_Msg_Name_1 := Chars (Source); Error_Msg_Uint_1 := Source_Siz; Error_Msg_Name_2 := Chars (Target); Error_Msg_Uint_2 := Target_Siz; Error_Msg ("\size of % is ^, size of % is ^?", Eloc); Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz); if Is_Discrete_Type (Source) and then Is_Discrete_Type (Target) then if Source_Siz > Target_Siz then Error_Msg ("\?^ high order bits of source will be ignored!", Eloc); elsif Is_Unsigned_Type (Source) then Error_Msg ("\?source will be extended with ^ high order " & "zero bits?!", Eloc); else Error_Msg ("\?source will be extended with ^ high order " & "sign bits!", Eloc); end if; elsif Source_Siz < Target_Siz then if Is_Discrete_Type (Target) then if Bytes_Big_Endian then Error_Msg ("\?target value will include ^ undefined " & "low order bits!", Eloc); else Error_Msg ("\?target value will include ^ undefined " & "high order bits!", Eloc); end if; else Error_Msg ("\?^ trailing bits of target value will be " & "undefined!", Eloc); end if; else pragma Assert (Source_Siz > Target_Siz); Error_Msg ("\?^ trailing bits of source will be ignored!", Eloc); end if; end if; end if; end if; -- If both types are access types, we need to check the alignment. -- If the alignment of both is specified, we can do it here. if Serious_Errors_Detected = 0 and then Ekind (Source) in Access_Kind and then Ekind (Target) in Access_Kind and then Target_Strict_Alignment and then Present (Designated_Type (Source)) and then Present (Designated_Type (Target)) then declare D_Source : constant Entity_Id := Designated_Type (Source); D_Target : constant Entity_Id := Designated_Type (Target); begin if Known_Alignment (D_Source) and then Known_Alignment (D_Target) then declare Source_Align : constant Uint := Alignment (D_Source); Target_Align : constant Uint := Alignment (D_Target); begin if Source_Align < Target_Align and then not Is_Tagged_Type (D_Source) -- Suppress warning if warnings suppressed on either -- type or either designated type. Note the use of -- OR here instead of OR ELSE. That is intentional, -- we would like to set flag Warnings_Off_Used in -- all types for which warnings are suppressed. and then not (Has_Warnings_Off (D_Source) or Has_Warnings_Off (D_Target) or Has_Warnings_Off (Source) or Has_Warnings_Off (Target)) then Error_Msg_Uint_1 := Target_Align; Error_Msg_Uint_2 := Source_Align; Error_Msg_Node_1 := D_Target; Error_Msg_Node_2 := D_Source; Error_Msg ("?alignment of & (^) is stricter than " & "alignment of & (^)!", Eloc); Error_Msg ("\?resulting access value may have invalid " & "alignment!", Eloc); end if; end; end if; end; end if; end; end loop; end Validate_Unchecked_Conversions; end Sem_Ch13;
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