X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Fada%2Fsem_ch6.adb;h=668a2a7b204aa37ca73c1977a957e2f304dbd215;hb=bb66f6b859a369e128c5df4a8e1a02476d4678ee;hp=45a2015850746c3b423f3c933106ba0dcd908899;hpb=7189d17fd684291638652f906a2c14487fe77419;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/ada/sem_ch6.adb b/gcc/ada/sem_ch6.adb index 45a20158507..668a2a7b204 100644 --- a/gcc/ada/sem_ch6.adb +++ b/gcc/ada/sem_ch6.adb @@ -6,18 +6,17 @@ -- -- -- B o d y -- -- -- --- Copyright (C) 1992-2005, Free Software Foundation, Inc. -- +-- Copyright (C) 1992-2008, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- --- ware Foundation; either version 2, or (at your option) any later ver- -- +-- 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 COPYING. If not, write -- --- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- --- MA 02111-1307, USA. -- +-- 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. -- @@ -31,10 +30,16 @@ with Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; with Expander; use Expander; +with Exp_Ch6; use Exp_Ch6; with Exp_Ch7; use Exp_Ch7; +with Exp_Ch9; use Exp_Ch9; +with Exp_Tss; use Exp_Tss; +with Exp_Util; use Exp_Util; with Fname; use Fname; with Freeze; use Freeze; +with Itypes; use Itypes; with Lib.Xref; use Lib.Xref; +with Layout; use Layout; with Namet; use Namet; with Lib; use Lib; with Nlists; use Nlists; @@ -75,10 +80,26 @@ with Validsw; use Validsw; package body Sem_Ch6 is + May_Hide_Profile : Boolean := False; + -- This flag is used to indicate that two formals in two subprograms being + -- checked for conformance differ only in that one is an access parameter + -- while the other is of a general access type with the same designated + -- type. In this case, if the rest of the signatures match, a call to + -- either subprogram may be ambiguous, which is worth a warning. The flag + -- is set in Compatible_Types, and the warning emitted in + -- New_Overloaded_Entity. + ----------------------- -- Local Subprograms -- ----------------------- + procedure Analyze_Return_Statement (N : Node_Id); + -- Common processing for simple_ and extended_return_statements + + procedure Analyze_Function_Return (N : Node_Id); + -- Subsidiary to Analyze_Return_Statement. Called when the return statement + -- applies to a [generic] function. + procedure Analyze_Return_Type (N : Node_Id); -- Subsidiary to Process_Formals: analyze subtype mark in function -- specification, in a context where the formals are visible and hide @@ -97,19 +118,15 @@ package body Sem_Ch6 is -- If proper warnings are enabled and the subprogram contains a construct -- that cannot be inlined, the offending construct is flagged accordingly. - type Conformance_Type is - (Type_Conformant, Mode_Conformant, Subtype_Conformant, Fully_Conformant); - -- Conformance type used for following call, meaning matches the - -- RM definitions of the corresponding terms. - procedure Check_Conformance - (New_Id : Entity_Id; - Old_Id : Entity_Id; - Ctype : Conformance_Type; - Errmsg : Boolean; - Conforms : out Boolean; - Err_Loc : Node_Id := Empty; - Get_Inst : Boolean := False); + (New_Id : Entity_Id; + Old_Id : Entity_Id; + Ctype : Conformance_Type; + Errmsg : Boolean; + Conforms : out Boolean; + Err_Loc : Node_Id := Empty; + Get_Inst : Boolean := False; + Skip_Controlling_Formals : Boolean := False); -- Given two entities, this procedure checks that the profiles associated -- with these entities meet the conformance criterion given by the third -- parameter. If they conform, Conforms is set True and control returns @@ -122,14 +139,6 @@ package body Sem_Ch6 is -- against a formal access-to-subprogram type so Get_Instance_Of must -- be called. - procedure Check_Overriding_Operation - (N : Node_Id; - Subp : Entity_Id); - -- Check that a subprogram with a pragma Overriding or Optional_Overriding - -- is legal. This check is performed here rather than in Sem_Prag because - -- the pragma must follow immediately the declaration, and can be treated - -- as part of the declaration itself, as described in AI-218. - procedure Check_Subprogram_Order (N : Node_Id); -- N is the N_Subprogram_Body node for a subprogram. This routine applies -- the alpha ordering rule for N if this ordering requirement applicable. @@ -137,23 +146,17 @@ package body Sem_Ch6 is procedure Check_Returns (HSS : Node_Id; Mode : Character; - Err : out Boolean); - -- Called to check for missing return statements in a function body, or - -- for returns present in a procedure body which has No_Return set. L is - -- the handled statement sequence for the subprogram body. This procedure - -- checks all flow paths to make sure they either have return (Mode = 'F') - -- or do not have a return (Mode = 'P'). The flag Err is set if there are - -- any control paths not explicitly terminated by a return in the function - -- case, and is True otherwise. - - function Conforming_Types - (T1 : Entity_Id; - T2 : Entity_Id; - Ctype : Conformance_Type; - Get_Inst : Boolean := False) return Boolean; - -- Check that two formal parameter types conform, checking both for - -- equality of base types, and where required statically matching - -- subtypes, depending on the setting of Ctype. + Err : out Boolean; + Proc : Entity_Id := Empty); + -- Called to check for missing return statements in a function body, or for + -- returns present in a procedure body which has No_Return set. HSS is the + -- handled statement sequence for the subprogram body. This procedure + -- checks all flow paths to make sure they either have return (Mode = 'F', + -- used for functions) or do not have a return (Mode = 'P', used for + -- No_Return procedures). The flag Err is set if there are any control + -- paths not explicitly terminated by a return in the function case, and is + -- True otherwise. Proc is the entity for the procedure case and is used + -- in posting the warning message. procedure Enter_Overloaded_Entity (S : Entity_Id); -- This procedure makes S, a new overloaded entity, into the first visible @@ -162,11 +165,6 @@ package body Sem_Ch6 is procedure Install_Entity (E : Entity_Id); -- Make single entity visible. Used for generic formals as well - procedure Install_Formals (Id : Entity_Id); - -- On entry to a subprogram body, make the formals visible. Note that - -- simply placing the subprogram on the scope stack is not sufficient: - -- the formals must become the current entities for their names. - function Is_Non_Overriding_Operation (Prev_E : Entity_Id; New_E : Entity_Id) return Boolean; @@ -184,17 +182,152 @@ package body Sem_Ch6 is -- Flag functions that can be called without parameters, i.e. those that -- have no parameters, or those for which defaults exist for all parameters - procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id); - -- If there is a separate spec for a subprogram or generic subprogram, the - -- formals of the body are treated as references to the corresponding - -- formals of the spec. This reference does not count as an actual use of - -- the formal, in order to diagnose formals that are unused in the body. + procedure Process_PPCs + (N : Node_Id; + Spec_Id : Entity_Id; + Body_Id : Entity_Id); + -- Called from Analyze_Body to deal with scanning post conditions for the + -- body and assembling and inserting the _postconditions procedure. N is + -- the node for the subprogram body and Body_Id/Spec_Id are the entities + -- for the body and separate spec (if there is no separate spec, Spec_Id + -- is Empty). procedure Set_Formal_Validity (Formal_Id : Entity_Id); -- Formal_Id is an formal parameter entity. This procedure deals with -- setting the proper validity status for this entity, which depends -- on the kind of parameter and the validity checking mode. + ------------------------------ + -- Analyze_Return_Statement -- + ------------------------------ + + procedure Analyze_Return_Statement (N : Node_Id) is + + pragma Assert (Nkind_In (N, N_Simple_Return_Statement, + N_Extended_Return_Statement)); + + Returns_Object : constant Boolean := + Nkind (N) = N_Extended_Return_Statement + or else + (Nkind (N) = N_Simple_Return_Statement + and then Present (Expression (N))); + -- True if we're returning something; that is, "return ;" + -- or "return Result : T [:= ...]". False for "return;". Used for error + -- checking: If Returns_Object is True, N should apply to a function + -- body; otherwise N should apply to a procedure body, entry body, + -- accept statement, or extended return statement. + + function Find_What_It_Applies_To return Entity_Id; + -- Find the entity representing the innermost enclosing body, accept + -- statement, or extended return statement. If the result is a callable + -- construct or extended return statement, then this will be the value + -- of the Return_Applies_To attribute. Otherwise, the program is + -- illegal. See RM-6.5(4/2). + + ----------------------------- + -- Find_What_It_Applies_To -- + ----------------------------- + + function Find_What_It_Applies_To return Entity_Id is + Result : Entity_Id := Empty; + + begin + -- Loop outward through the Scope_Stack, skipping blocks and loops + + for J in reverse 0 .. Scope_Stack.Last loop + Result := Scope_Stack.Table (J).Entity; + exit when Ekind (Result) /= E_Block and then + Ekind (Result) /= E_Loop; + end loop; + + pragma Assert (Present (Result)); + return Result; + end Find_What_It_Applies_To; + + -- Local declarations + + Scope_Id : constant Entity_Id := Find_What_It_Applies_To; + Kind : constant Entity_Kind := Ekind (Scope_Id); + Loc : constant Source_Ptr := Sloc (N); + Stm_Entity : constant Entity_Id := + New_Internal_Entity + (E_Return_Statement, Current_Scope, Loc, 'R'); + + -- Start of processing for Analyze_Return_Statement + + begin + Set_Return_Statement_Entity (N, Stm_Entity); + + Set_Etype (Stm_Entity, Standard_Void_Type); + Set_Return_Applies_To (Stm_Entity, Scope_Id); + + -- Place Return entity on scope stack, to simplify enforcement of 6.5 + -- (4/2): an inner return statement will apply to this extended return. + + if Nkind (N) = N_Extended_Return_Statement then + Push_Scope (Stm_Entity); + end if; + + -- Check that pragma No_Return is obeyed + + if No_Return (Scope_Id) then + Error_Msg_N ("RETURN statement not allowed (No_Return)", N); + end if; + + -- Warn on any unassigned OUT parameters if in procedure + + if Ekind (Scope_Id) = E_Procedure then + Warn_On_Unassigned_Out_Parameter (N, Scope_Id); + end if; + + -- Check that functions return objects, and other things do not + + if Kind = E_Function or else Kind = E_Generic_Function then + if not Returns_Object then + Error_Msg_N ("missing expression in return from function", N); + end if; + + elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then + if Returns_Object then + Error_Msg_N ("procedure cannot return value (use function)", N); + end if; + + elsif Kind = E_Entry or else Kind = E_Entry_Family then + if Returns_Object then + if Is_Protected_Type (Scope (Scope_Id)) then + Error_Msg_N ("entry body cannot return value", N); + else + Error_Msg_N ("accept statement cannot return value", N); + end if; + end if; + + elsif Kind = E_Return_Statement then + + -- We are nested within another return statement, which must be an + -- extended_return_statement. + + if Returns_Object then + Error_Msg_N + ("extended_return_statement cannot return value; " & + "use `""RETURN;""`", N); + end if; + + else + Error_Msg_N ("illegal context for return statement", N); + end if; + + if Kind = E_Function or else Kind = E_Generic_Function then + Analyze_Function_Return (N); + end if; + + if Nkind (N) = N_Extended_Return_Statement then + End_Scope; + end if; + + Kill_Current_Values (Last_Assignment_Only => True); + Check_Unreachable_Code (N); + end Analyze_Return_Statement; + --------------------------------------------- -- Analyze_Abstract_Subprogram_Declaration -- --------------------------------------------- @@ -206,7 +339,7 @@ package body Sem_Ch6 is begin Generate_Definition (Designator); - Set_Is_Abstract (Designator); + Set_Is_Abstract_Subprogram (Designator); New_Overloaded_Entity (Designator); Check_Delayed_Subprogram (Designator); @@ -215,11 +348,33 @@ package body Sem_Ch6 is if Ekind (Scope (Designator)) = E_Protected_Type then Error_Msg_N ("abstract subprogram not allowed in protected type", N); + + -- Issue a warning if the abstract subprogram is neither a dispatching + -- operation nor an operation that overrides an inherited subprogram or + -- predefined operator, since this most likely indicates a mistake. + + elsif Warn_On_Redundant_Constructs + and then not Is_Dispatching_Operation (Designator) + and then not Is_Overriding_Operation (Designator) + and then (not Is_Operator_Symbol_Name (Chars (Designator)) + or else Scop /= Scope (Etype (First_Formal (Designator)))) + then + Error_Msg_N + ("?abstract subprogram is not dispatching or overriding", N); end if; Generate_Reference_To_Formals (Designator); end Analyze_Abstract_Subprogram_Declaration; + ---------------------------------------- + -- Analyze_Extended_Return_Statement -- + ---------------------------------------- + + procedure Analyze_Extended_Return_Statement (N : Node_Id) is + begin + Analyze_Return_Statement (N); + end Analyze_Extended_Return_Statement; + ---------------------------- -- Analyze_Function_Call -- ---------------------------- @@ -233,7 +388,7 @@ package body Sem_Ch6 is Analyze (P); -- A call of the form A.B (X) may be an Ada05 call, which is rewritten - -- as B(A, X). If the rewriting is successful, the call has been + -- as B (A, X). If the rewriting is successful, the call has been -- analyzed and we just return. if Nkind (P) = N_Selected_Component @@ -255,7 +410,6 @@ package body Sem_Ch6 is if Present (L) then Actual := First (L); - while Present (Actual) loop Analyze (Actual); Check_Parameterless_Call (Actual); @@ -266,6 +420,333 @@ package body Sem_Ch6 is Analyze_Call (N); end Analyze_Function_Call; + ----------------------------- + -- Analyze_Function_Return -- + ----------------------------- + + procedure Analyze_Function_Return (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Stm_Entity : constant Entity_Id := Return_Statement_Entity (N); + Scope_Id : constant Entity_Id := Return_Applies_To (Stm_Entity); + + R_Type : constant Entity_Id := Etype (Scope_Id); + -- Function result subtype + + procedure Check_Limited_Return (Expr : Node_Id); + -- Check the appropriate (Ada 95 or Ada 2005) rules for returning + -- limited types. Used only for simple return statements. + -- Expr is the expression returned. + + procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id); + -- Check that the return_subtype_indication properly matches the result + -- subtype of the function, as required by RM-6.5(5.1/2-5.3/2). + + -------------------------- + -- Check_Limited_Return -- + -------------------------- + + procedure Check_Limited_Return (Expr : Node_Id) is + begin + -- Ada 2005 (AI-318-02): Return-by-reference types have been + -- removed and replaced by anonymous access results. This is an + -- incompatibility with Ada 95. Not clear whether this should be + -- enforced yet or perhaps controllable with special switch. ??? + + if Is_Limited_Type (R_Type) + and then Comes_From_Source (N) + and then not In_Instance_Body + and then not OK_For_Limited_Init_In_05 (Expr) + then + -- Error in Ada 2005 + + if Ada_Version >= Ada_05 + and then not Debug_Flag_Dot_L + and then not GNAT_Mode + then + Error_Msg_N + ("(Ada 2005) cannot copy object of a limited type " & + "(RM-2005 6.5(5.5/2))", Expr); + if Is_Inherently_Limited_Type (R_Type) then + Error_Msg_N + ("\return by reference not permitted in Ada 2005", Expr); + end if; + + -- Warn in Ada 95 mode, to give folks a heads up about this + -- incompatibility. + + -- In GNAT mode, this is just a warning, to allow it to be + -- evilly turned off. Otherwise it is a real error. + + elsif Warn_On_Ada_2005_Compatibility or GNAT_Mode then + if Is_Inherently_Limited_Type (R_Type) then + Error_Msg_N + ("return by reference not permitted in Ada 2005 " & + "(RM-2005 6.5(5.5/2))?", Expr); + else + Error_Msg_N + ("cannot copy object of a limited type in Ada 2005 " & + "(RM-2005 6.5(5.5/2))?", Expr); + end if; + + -- Ada 95 mode, compatibility warnings disabled + + else + return; -- skip continuation messages below + end if; + + Error_Msg_N + ("\consider switching to return of access type", Expr); + Explain_Limited_Type (R_Type, Expr); + end if; + end Check_Limited_Return; + + ------------------------------------- + -- Check_Return_Subtype_Indication -- + ------------------------------------- + + procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id) is + Return_Obj : constant Node_Id := Defining_Identifier (Obj_Decl); + R_Stm_Type : constant Entity_Id := Etype (Return_Obj); + -- Subtype given in the extended return statement; + -- this must match R_Type. + + Subtype_Ind : constant Node_Id := + Object_Definition (Original_Node (Obj_Decl)); + + R_Type_Is_Anon_Access : + constant Boolean := + Ekind (R_Type) = E_Anonymous_Access_Subprogram_Type + or else + Ekind (R_Type) = E_Anonymous_Access_Protected_Subprogram_Type + or else + Ekind (R_Type) = E_Anonymous_Access_Type; + -- True if return type of the function is an anonymous access type + -- Can't we make Is_Anonymous_Access_Type in einfo ??? + + R_Stm_Type_Is_Anon_Access : + constant Boolean := + Ekind (R_Stm_Type) = E_Anonymous_Access_Subprogram_Type + or else + Ekind (R_Stm_Type) = E_Anonymous_Access_Protected_Subprogram_Type + or else + Ekind (R_Stm_Type) = E_Anonymous_Access_Type; + -- True if type of the return object is an anonymous access type + + begin + -- First, avoid cascade errors: + + if Error_Posted (Obj_Decl) or else Error_Posted (Subtype_Ind) then + return; + end if; + + -- "return access T" case; check that the return statement also has + -- "access T", and that the subtypes statically match: + + if R_Type_Is_Anon_Access then + if R_Stm_Type_Is_Anon_Access then + if Base_Type (Designated_Type (R_Stm_Type)) /= + Base_Type (Designated_Type (R_Type)) + or else not Subtypes_Statically_Match (R_Stm_Type, R_Type) + then + Error_Msg_N + ("subtype must statically match function result subtype", + Subtype_Mark (Subtype_Ind)); + end if; + + else + Error_Msg_N ("must use anonymous access type", Subtype_Ind); + end if; + + -- Subtype_indication case; check that the types are the same, and + -- statically match if appropriate. A null exclusion may be present + -- on the return type, on the function specification, on the object + -- declaration or on the subtype itself. + + elsif Base_Type (R_Stm_Type) = Base_Type (R_Type) then + if Is_Access_Type (R_Type) + and then + (Can_Never_Be_Null (R_Type) + or else Null_Exclusion_Present (Parent (Scope_Id))) /= + Can_Never_Be_Null (R_Stm_Type) + then + Error_Msg_N + ("subtype must statically match function result subtype", + Subtype_Ind); + end if; + + if Is_Constrained (R_Type) then + if not Subtypes_Statically_Match (R_Stm_Type, R_Type) then + Error_Msg_N + ("subtype must statically match function result subtype", + Subtype_Ind); + end if; + end if; + + -- If the function's result type doesn't match the return object + -- entity's type, then we check for the case where the result type + -- is class-wide, and allow the declaration if the type of the object + -- definition matches the class-wide type. This prevents rejection + -- in the case where the object declaration is initialized by a call + -- to a build-in-place function with a specific result type and the + -- object entity had its type changed to that specific type. (Note + -- that the ARG believes that return objects should be allowed to + -- have a type covered by a class-wide result type in any case, so + -- once that relaxation is made (see AI05-32), the above check for + -- type compatibility should be changed to test Covers rather than + -- equality, and then the following special test will no longer be + -- needed. ???) + + elsif Is_Class_Wide_Type (R_Type) + and then + R_Type = Etype (Object_Definition (Original_Node (Obj_Decl))) + then + null; + + else + Error_Msg_N + ("wrong type for return_subtype_indication", Subtype_Ind); + end if; + end Check_Return_Subtype_Indication; + + --------------------- + -- Local Variables -- + --------------------- + + Expr : Node_Id; + + -- Start of processing for Analyze_Function_Return + + begin + Set_Return_Present (Scope_Id); + + if Nkind (N) = N_Simple_Return_Statement then + Expr := Expression (N); + Analyze_And_Resolve (Expr, R_Type); + Check_Limited_Return (Expr); + + else + -- Analyze parts specific to extended_return_statement: + + declare + Obj_Decl : constant Node_Id := + Last (Return_Object_Declarations (N)); + + HSS : constant Node_Id := Handled_Statement_Sequence (N); + + begin + Expr := Expression (Obj_Decl); + + -- Note: The check for OK_For_Limited_Init will happen in + -- Analyze_Object_Declaration; we treat it as a normal + -- object declaration. + + Analyze (Obj_Decl); + + Set_Is_Return_Object (Defining_Identifier (Obj_Decl)); + Check_Return_Subtype_Indication (Obj_Decl); + + if Present (HSS) then + Analyze (HSS); + + if Present (Exception_Handlers (HSS)) then + + -- ???Has_Nested_Block_With_Handler needs to be set. + -- Probably by creating an actual N_Block_Statement. + -- Probably in Expand. + + null; + end if; + end if; + + Check_References (Stm_Entity); + end; + end if; + + -- Case of Expr present + + if Present (Expr) + + -- Defend against previous errors + + and then Nkind (Expr) /= N_Empty + and then Present (Etype (Expr)) + then + -- Apply constraint check. Note that this is done before the implicit + -- conversion of the expression done for anonymous access types to + -- ensure correct generation of the null-excluding check asssociated + -- with null-excluding expressions found in return statements. + + Apply_Constraint_Check (Expr, R_Type); + + -- Ada 2005 (AI-318-02): When the result type is an anonymous access + -- type, apply an implicit conversion of the expression to that type + -- to force appropriate static and run-time accessibility checks. + + if Ada_Version >= Ada_05 + and then Ekind (R_Type) = E_Anonymous_Access_Type + then + Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr))); + Analyze_And_Resolve (Expr, R_Type); + end if; + + -- If the result type is class-wide, then check that the return + -- expression's type is not declared at a deeper level than the + -- function (RM05-6.5(5.6/2)). + + if Ada_Version >= Ada_05 + and then Is_Class_Wide_Type (R_Type) + then + if Type_Access_Level (Etype (Expr)) > + Subprogram_Access_Level (Scope_Id) + then + Error_Msg_N + ("level of return expression type is deeper than " & + "class-wide function!", Expr); + end if; + end if; + + if (Is_Class_Wide_Type (Etype (Expr)) + or else Is_Dynamically_Tagged (Expr)) + and then not Is_Class_Wide_Type (R_Type) + then + Error_Msg_N + ("dynamically tagged expression not allowed!", Expr); + end if; + + -- ??? A real run-time accessibility check is needed in cases + -- involving dereferences of access parameters. For now we just + -- check the static cases. + + if (Ada_Version < Ada_05 or else Debug_Flag_Dot_L) + and then Is_Inherently_Limited_Type (Etype (Scope_Id)) + and then Object_Access_Level (Expr) > + Subprogram_Access_Level (Scope_Id) + then + Rewrite (N, + Make_Raise_Program_Error (Loc, + Reason => PE_Accessibility_Check_Failed)); + Analyze (N); + + Error_Msg_N + ("cannot return a local value by reference?", N); + Error_Msg_NE + ("\& will be raised at run time?", + N, Standard_Program_Error); + end if; + + if Known_Null (Expr) + and then Nkind (Parent (Scope_Id)) = N_Function_Specification + and then Null_Exclusion_Present (Parent (Scope_Id)) + then + Apply_Compile_Time_Constraint_Error + (N => Expr, + Msg => "(Ada 2005) null not allowed for " + & "null-excluding return?", + Reason => CE_Null_Not_Allowed); + end if; + end if; + end Analyze_Function_Return; + ------------------------------------- -- Analyze_Generic_Subprogram_Body -- ------------------------------------- @@ -336,7 +817,7 @@ package body Sem_Ch6 is -- needed to process the formals declarations. Then make the formals -- visible in a separate step. - New_Scope (Gen_Id); + Push_Scope (Gen_Id); declare E : Entity_Id; @@ -374,10 +855,11 @@ package body Sem_Ch6 is -- Visible generic entity is callable within its own body - Set_Ekind (Gen_Id, Ekind (Body_Id)); - Set_Ekind (Body_Id, E_Subprogram_Body); - Set_Convention (Body_Id, Convention (Gen_Id)); - Set_Scope (Body_Id, Scope (Gen_Id)); + Set_Ekind (Gen_Id, Ekind (Body_Id)); + Set_Ekind (Body_Id, E_Subprogram_Body); + Set_Convention (Body_Id, Convention (Gen_Id)); + Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Gen_Id)); + Set_Scope (Body_Id, Scope (Gen_Id)); Check_Fully_Conformant (Body_Id, Gen_Id, Body_Id); if Nkind (N) = N_Subprogram_Body_Stub then @@ -403,6 +885,10 @@ package body Sem_Ch6 is Set_Is_Immediately_Visible (Gen_Id); Reference_Body_Formals (Gen_Id, Body_Id); + if Is_Child_Unit (Gen_Id) then + Generate_Reference (Gen_Id, Scope (Gen_Id), 'k', False); + end if; + Set_Actual_Subtypes (N, Current_Scope); Analyze_Declarations (Declarations (N)); Check_Completion; @@ -428,7 +914,10 @@ package body Sem_Ch6 is Set_Ekind (Gen_Id, Kind); Generate_Reference (Gen_Id, Body_Id, 'b', Set_Ref => False); - Style.Check_Identifier (Body_Id, Gen_Id); + + if Style_Check then + Style.Check_Identifier (Body_Id, Gen_Id); + end if; End_Generic; end Analyze_Generic_Subprogram_Body; @@ -447,14 +936,16 @@ package body Sem_Ch6 is Par : constant Node_Id := Parent (N); begin - if (Nkind (Par) = N_Function_Call and then N = Name (Par)) + if (Nkind (Par) = N_Function_Call + and then N = Name (Par)) or else Nkind (Par) = N_Function_Instantiation - or else (Nkind (Par) = N_Indexed_Component and then N = Prefix (Par)) + or else (Nkind (Par) = N_Indexed_Component + and then N = Prefix (Par)) or else (Nkind (Par) = N_Pragma_Argument_Association and then not Is_Pragma_String_Literal (Par)) or else Nkind (Par) = N_Subprogram_Renaming_Declaration - or else (Nkind (Par) = N_Attribute_Reference - and then Attribute_Name (Par) /= Name_Value) + or else (Nkind (Par) = N_Attribute_Reference + and then Attribute_Name (Par) /= Name_Value) then Find_Direct_Name (N); @@ -515,6 +1006,14 @@ package body Sem_Ch6 is Analyze (P); + -- If this is a call of the form Obj.Op, the call may have been + -- analyzed and possibly rewritten into a block, in which case + -- we are done. + + if Analyzed (N) then + return; + end if; + -- If error analyzing prefix, then set Any_Type as result and return if Etype (P) = Any_Type then @@ -679,130 +1178,68 @@ package body Sem_Ch6 is -- Anything else is an error else - Error_Msg_N ("Invalid procedure or entry call", N); + Error_Msg_N ("invalid procedure or entry call", N); end if; end Analyze_Procedure_Call; - ------------------------------ - -- Analyze_Return_Statement -- - ------------------------------ - - procedure Analyze_Return_Statement (N : Node_Id) is - Loc : constant Source_Ptr := Sloc (N); - Expr : Node_Id; - Scope_Id : Entity_Id; - Kind : Entity_Kind; - R_Type : Entity_Id; + ------------------------------------- + -- Analyze_Simple_Return_Statement -- + ------------------------------------- + procedure Analyze_Simple_Return_Statement (N : Node_Id) is begin - -- Find subprogram or accept statement enclosing the return statement - - Scope_Id := Empty; - for J in reverse 0 .. Scope_Stack.Last loop - Scope_Id := Scope_Stack.Table (J).Entity; - exit when Ekind (Scope_Id) /= E_Block and then - Ekind (Scope_Id) /= E_Loop; - end loop; + if Present (Expression (N)) then + Mark_Coextensions (N, Expression (N)); + end if; - pragma Assert (Present (Scope_Id)); + Analyze_Return_Statement (N); + end Analyze_Simple_Return_Statement; - Kind := Ekind (Scope_Id); - Expr := Expression (N); + ------------------------- + -- Analyze_Return_Type -- + ------------------------- - if Kind /= E_Function - and then Kind /= E_Generic_Function - and then Kind /= E_Procedure - and then Kind /= E_Generic_Procedure - and then Kind /= E_Entry - and then Kind /= E_Entry_Family - then - Error_Msg_N ("illegal context for return statement", N); + procedure Analyze_Return_Type (N : Node_Id) is + Designator : constant Entity_Id := Defining_Entity (N); + Typ : Entity_Id := Empty; - elsif Present (Expr) then - if Kind = E_Function or else Kind = E_Generic_Function then - Set_Return_Present (Scope_Id); - R_Type := Etype (Scope_Id); - Set_Return_Type (N, R_Type); - Analyze_And_Resolve (Expr, R_Type); + begin + -- Normal case where result definition does not indicate an error - if (Is_Class_Wide_Type (Etype (Expr)) - or else Is_Dynamically_Tagged (Expr)) - and then not Is_Class_Wide_Type (R_Type) - then - Error_Msg_N - ("dynamically tagged expression not allowed!", Expr); - end if; + if Result_Definition (N) /= Error then + if Nkind (Result_Definition (N)) = N_Access_Definition then + Typ := Access_Definition (N, Result_Definition (N)); + Set_Parent (Typ, Result_Definition (N)); + Set_Is_Local_Anonymous_Access (Typ); + Set_Etype (Designator, Typ); - Apply_Constraint_Check (Expr, R_Type); + -- Subtype_Mark case - -- ??? A real run-time accessibility check is needed in cases - -- involving dereferences of access parameters. For now we just - -- check the static cases. + else + Find_Type (Result_Definition (N)); + Typ := Entity (Result_Definition (N)); + Set_Etype (Designator, Typ); - if Is_Return_By_Reference_Type (Etype (Scope_Id)) - and then Object_Access_Level (Expr) - > Subprogram_Access_Level (Scope_Id) + if Ekind (Typ) = E_Incomplete_Type + and then Is_Value_Type (Typ) then - Rewrite (N, - Make_Raise_Program_Error (Loc, - Reason => PE_Accessibility_Check_Failed)); - Analyze (N); + null; + elsif Ekind (Typ) = E_Incomplete_Type + or else (Is_Class_Wide_Type (Typ) + and then + Ekind (Root_Type (Typ)) = E_Incomplete_Type) + then Error_Msg_N - ("cannot return a local value by reference?", N); - Error_Msg_NE - ("& will be raised at run time?!", - N, Standard_Program_Error); + ("invalid use of incomplete type", Result_Definition (N)); end if; - - elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then - Error_Msg_N ("procedure cannot return value (use function)", N); - - else - Error_Msg_N ("accept statement cannot return value", N); - end if; - - -- No expression present - - else - if Kind = E_Function or Kind = E_Generic_Function then - Error_Msg_N ("missing expression in return from function", N); - end if; - - if (Ekind (Scope_Id) = E_Procedure - or else Ekind (Scope_Id) = E_Generic_Procedure) - and then No_Return (Scope_Id) - then - Error_Msg_N - ("RETURN statement not allowed (No_Return)", N); end if; - end if; - Check_Unreachable_Code (N); - end Analyze_Return_Statement; + -- Ada 2005 (AI-231): Ensure proper usage of null exclusion - ------------------------- - -- Analyze_Return_Type -- - ------------------------- + Null_Exclusion_Static_Checks (N); - procedure Analyze_Return_Type (N : Node_Id) is - Designator : constant Entity_Id := Defining_Entity (N); - Typ : Entity_Id := Empty; - - begin - if Subtype_Mark (N) /= Error then - Find_Type (Subtype_Mark (N)); - Typ := Entity (Subtype_Mark (N)); - Set_Etype (Designator, Typ); - - if Ekind (Typ) = E_Incomplete_Type - or else (Is_Class_Wide_Type (Typ) - and then - Ekind (Root_Type (Typ)) = E_Incomplete_Type) - then - Error_Msg_N - ("invalid use of incomplete type", Subtype_Mark (N)); - end if; + -- Case where result definition does indicate an error else Set_Etype (Designator, Any_Type); @@ -824,42 +1261,264 @@ package body Sem_Ch6 is Body_Id : Entity_Id := Defining_Entity (Body_Spec); Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id); Body_Deleted : constant Boolean := False; - - HSS : Node_Id; - Spec_Id : Entity_Id; - Spec_Decl : Node_Id := Empty; - Last_Formal : Entity_Id := Empty; Conformant : Boolean; + HSS : Node_Id; Missing_Ret : Boolean; P_Ent : Entity_Id; + Prot_Typ : Entity_Id := Empty; + Spec_Id : Entity_Id; + Spec_Decl : Node_Id := Empty; + + Last_Real_Spec_Entity : Entity_Id := Empty; + -- When we analyze a separate spec, the entity chain ends up containing + -- the formals, as well as any itypes generated during analysis of the + -- default expressions for parameters, or the arguments of associated + -- precondition/postcondition pragmas (which are analyzed in the context + -- of the spec since they have visibility on formals). + -- + -- These entities belong with the spec and not the body. However we do + -- the analysis of the body in the context of the spec (again to obtain + -- visibility to the formals), and all the entities generated during + -- this analysis end up also chained to the entity chain of the spec. + -- But they really belong to the body, and there is circuitry to move + -- them from the spec to the body. + -- + -- However, when we do this move, we don't want to move the real spec + -- entities (first para above) to the body. The Last_Real_Spec_Entity + -- variable points to the last real spec entity, so we only move those + -- chained beyond that point. It is initialized to Empty to deal with + -- the case where there is no separate spec. + + procedure Check_Anonymous_Return; + -- (Ada 2005): if a function returns an access type that denotes a task, + -- or a type that contains tasks, we must create a master entity for + -- the anonymous type, which typically will be used in an allocator + -- in the body of the function. + + procedure Check_Inline_Pragma (Spec : in out Node_Id); + -- Look ahead to recognize a pragma that may appear after the body. + -- If there is a previous spec, check that it appears in the same + -- declarative part. If the pragma is Inline_Always, perform inlining + -- unconditionally, otherwise only if Front_End_Inlining is requested. + -- If the body acts as a spec, and inlining is required, we create a + -- subprogram declaration for it, in order to attach the body to inline. + -- If pragma does not appear after the body, check whether there is + -- an inline pragma before any local declarations. + + procedure Set_Trivial_Subprogram (N : Node_Id); + -- Sets the Is_Trivial_Subprogram flag in both spec and body of the + -- subprogram whose body is being analyzed. N is the statement node + -- causing the flag to be set, if the following statement is a return + -- of an entity, we mark the entity as set in source to suppress any + -- warning on the stylized use of function stubs with a dummy return. + + procedure Verify_Overriding_Indicator; + -- If there was a previous spec, the entity has been entered in the + -- current scope previously. If the body itself carries an overriding + -- indicator, check that it is consistent with the known status of the + -- entity. + + ---------------------------- + -- Check_Anonymous_Return -- + ---------------------------- + + procedure Check_Anonymous_Return is + Decl : Node_Id; + Scop : Entity_Id; + + begin + if Present (Spec_Id) then + Scop := Spec_Id; + else + Scop := Body_Id; + end if; + + if Ekind (Scop) = E_Function + and then Ekind (Etype (Scop)) = E_Anonymous_Access_Type + and then Has_Task (Designated_Type (Etype (Scop))) + and then Expander_Active + then + Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Name_uMaster), + Constant_Present => True, + Object_Definition => + New_Reference_To (RTE (RE_Master_Id), Loc), + Expression => + Make_Explicit_Dereference (Loc, + New_Reference_To (RTE (RE_Current_Master), Loc))); + + if Present (Declarations (N)) then + Prepend (Decl, Declarations (N)); + else + Set_Declarations (N, New_List (Decl)); + end if; - procedure Check_Following_Pragma; - -- If front-end inlining is enabled, look ahead to recognize a pragma - -- that may appear after the body. + Set_Master_Id (Etype (Scop), Defining_Identifier (Decl)); + Set_Has_Master_Entity (Scop); + end if; + end Check_Anonymous_Return; + + ------------------------- + -- Check_Inline_Pragma -- + ------------------------- + + procedure Check_Inline_Pragma (Spec : in out Node_Id) is + Prag : Node_Id; + Plist : List_Id; + + function Is_Inline_Pragma (N : Node_Id) return Boolean; + -- Simple predicate, used twice. + + ----------------------- + -- Is_Inline_Pragma -- + ----------------------- + + function Is_Inline_Pragma (N : Node_Id) return Boolean is + begin + return + Nkind (N) = N_Pragma + and then + (Pragma_Name (N) = Name_Inline_Always + or else + (Front_End_Inlining + and then Pragma_Name (N) = Name_Inline)) + and then + Chars + (Expression (First (Pragma_Argument_Associations (N)))) + = Chars (Body_Id); + end Is_Inline_Pragma; - procedure Check_Following_Pragma is - Prag : Node_Id; + -- Start of processing for Check_Inline_Pragma begin - if Front_End_Inlining - and then Is_List_Member (N) - and then Present (Spec_Decl) - and then List_Containing (N) = List_Containing (Spec_Decl) + if not Expander_Active then + return; + end if; + + if Is_List_Member (N) + and then Present (Next (N)) + and then Is_Inline_Pragma (Next (N)) then Prag := Next (N); - if Present (Prag) - and then Nkind (Prag) = N_Pragma - and then Get_Pragma_Id (Chars (Prag)) = Pragma_Inline - and then - Chars - (Expression (First (Pragma_Argument_Associations (Prag)))) - = Chars (Body_Id) + elsif Nkind (N) /= N_Subprogram_Body_Stub + and then Present (Declarations (N)) + and then Is_Inline_Pragma (First (Declarations (N))) + then + Prag := First (Declarations (N)); + + else + Prag := Empty; + end if; + + if Present (Prag) then + if Present (Spec_Id) then + if List_Containing (N) = + List_Containing (Unit_Declaration_Node (Spec_Id)) + then + Analyze (Prag); + end if; + + else + -- Create a subprogram declaration, to make treatment uniform + + declare + Subp : constant Entity_Id := + Make_Defining_Identifier (Loc, Chars (Body_Id)); + Decl : constant Node_Id := + Make_Subprogram_Declaration (Loc, + Specification => New_Copy_Tree (Specification (N))); + begin + Set_Defining_Unit_Name (Specification (Decl), Subp); + + if Present (First_Formal (Body_Id)) then + Plist := Copy_Parameter_List (Body_Id); + Set_Parameter_Specifications + (Specification (Decl), Plist); + end if; + + Insert_Before (N, Decl); + Analyze (Decl); + Analyze (Prag); + Set_Has_Pragma_Inline (Subp); + + if Pragma_Name (Prag) = Name_Inline_Always then + Set_Is_Inlined (Subp); + Set_Has_Pragma_Inline_Always (Subp); + end if; + + Spec := Subp; + end; + end if; + end if; + end Check_Inline_Pragma; + + ---------------------------- + -- Set_Trivial_Subprogram -- + ---------------------------- + + procedure Set_Trivial_Subprogram (N : Node_Id) is + Nxt : constant Node_Id := Next (N); + + begin + Set_Is_Trivial_Subprogram (Body_Id); + + if Present (Spec_Id) then + Set_Is_Trivial_Subprogram (Spec_Id); + end if; + + if Present (Nxt) + and then Nkind (Nxt) = N_Simple_Return_Statement + and then No (Next (Nxt)) + and then Present (Expression (Nxt)) + and then Is_Entity_Name (Expression (Nxt)) + then + Set_Never_Set_In_Source (Entity (Expression (Nxt)), False); + end if; + end Set_Trivial_Subprogram; + + --------------------------------- + -- Verify_Overriding_Indicator -- + --------------------------------- + + procedure Verify_Overriding_Indicator is + begin + if Must_Override (Body_Spec) then + if Nkind (Spec_Id) = N_Defining_Operator_Symbol + and then Operator_Matches_Spec (Spec_Id, Spec_Id) + then + null; + + elsif not Is_Overriding_Operation (Spec_Id) then + Error_Msg_NE + ("subprogram& is not overriding", Body_Spec, Spec_Id); + end if; + + elsif Must_Not_Override (Body_Spec) then + if Is_Overriding_Operation (Spec_Id) then + Error_Msg_NE + ("subprogram& overrides inherited operation", + Body_Spec, Spec_Id); + + elsif Nkind (Spec_Id) = N_Defining_Operator_Symbol + and then Operator_Matches_Spec (Spec_Id, Spec_Id) then - Analyze (Prag); + Error_Msg_NE + ("subprogram & overrides predefined operator ", + Body_Spec, Spec_Id); + + -- If this is not a primitive operation the overriding indicator + -- is altogether illegal. + + elsif not Is_Primitive (Spec_Id) then + Error_Msg_N ("overriding indicator only allowed " & + "if subprogram is primitive", + Body_Spec); end if; end if; - end Check_Following_Pragma; + end Verify_Overriding_Indicator; -- Start of processing for Analyze_Subprogram_Body @@ -872,7 +1531,7 @@ package body Sem_Ch6 is Write_Eol; end if; - Trace_Scope (N, Body_Id, " Analyze subprogram"); + Trace_Scope (N, Body_Id, " Analyze subprogram: "); -- Generic subprograms are handled separately. They always have a -- generic specification. Determine whether current scope has a @@ -933,8 +1592,7 @@ package body Sem_Ch6 is -- subprogram will get frozen too late (there may be code within -- the body that depends on the subprogram having been frozen, -- such as uses of extra formals), so we force it to be frozen - -- here. Same holds if the body and the spec are compilation - -- units. + -- here. Same holds if the body and spec are compilation units. if No (Spec_Id) then Freeze_Before (N, Body_Id); @@ -983,6 +1641,8 @@ package body Sem_Ch6 is end loop; end if; + Check_Inline_Pragma (Spec_Id); + -- Case of fully private operation in the body of the protected type. -- We must create a declaration for the subprogram, in order to attach -- the protected subprogram that will be used in internal calls. @@ -1007,29 +1667,11 @@ package body Sem_Ch6 is if Present (Formal) or else Expander_Active then - Plist := New_List; - + Plist := Copy_Parameter_List (Body_Id); else Plist := No_List; end if; - while Present (Formal) loop - Append - (Make_Parameter_Specification (Loc, - Defining_Identifier => - Make_Defining_Identifier (Sloc (Formal), - Chars => Chars (Formal)), - In_Present => In_Present (Parent (Formal)), - Out_Present => Out_Present (Parent (Formal)), - Parameter_Type => - New_Reference_To (Etype (Formal), Loc), - Expression => - New_Copy_Tree (Expression (Parent (Formal)))), - Plist); - - Next_Formal (Formal); - end loop; - if Nkind (Body_Spec) = N_Procedure_Specification then New_Spec := Make_Procedure_Specification (Loc, @@ -1044,7 +1686,8 @@ package body Sem_Ch6 is Make_Defining_Identifier (Sloc (Body_Id), Chars => Chars (Body_Id)), Parameter_Specifications => Plist, - Subtype_Mark => New_Occurrence_Of (Etype (Body_Id), Loc)); + Result_Definition => + New_Occurrence_Of (Etype (Body_Id), Loc)); end if; Decl := @@ -1066,6 +1709,29 @@ package body Sem_Ch6 is elsif Present (Spec_Id) then Spec_Decl := Unit_Declaration_Node (Spec_Id); + Verify_Overriding_Indicator; + + -- In general, the spec will be frozen when we start analyzing the + -- body. However, for internally generated operations, such as + -- wrapper functions for inherited operations with controlling + -- results, the spec may not have been frozen by the time we + -- expand the freeze actions that include the bodies. In particular, + -- extra formals for accessibility or for return-in-place may need + -- to be generated. Freeze nodes, if any, are inserted before the + -- current body. + + if not Is_Frozen (Spec_Id) + and then Expander_Active + then + -- Force the generation of its freezing node to ensure proper + -- management of access types in the backend. + + -- This is definitely needed for some cases, but it is not clear + -- why, to be investigated further??? + + Set_Has_Delayed_Freeze (Spec_Id); + Insert_Actions (N, Freeze_Entity (Spec_Id, Loc)); + end if; end if; -- Place subprogram on scope stack, and make formals visible. If there @@ -1073,6 +1739,11 @@ package body Sem_Ch6 is if Present (Spec_Id) then Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False); + + if Is_Child_Unit (Spec_Id) then + Generate_Reference (Spec_Id, Scope (Spec_Id), 'k', False); + end if; + if Style_Check then Style.Check_Identifier (Body_Id, Spec_Id); end if; @@ -1080,15 +1751,16 @@ package body Sem_Ch6 is Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id)); Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id)); - if Is_Abstract (Spec_Id) then + if Is_Abstract_Subprogram (Spec_Id) then Error_Msg_N ("an abstract subprogram cannot have a body", N); return; + else Set_Convention (Body_Id, Convention (Spec_Id)); Set_Has_Completion (Spec_Id); if Is_Protected_Type (Scope (Spec_Id)) then - Set_Privals_Chain (Spec_Id, New_Elmt_List); + Prot_Typ := Scope (Spec_Id); end if; -- If this is a body generated for a renaming, do not check for @@ -1108,10 +1780,11 @@ package body Sem_Ch6 is N_Subprogram_Renaming_Declaration)) then Conformant := True; + else Check_Conformance (Body_Id, Spec_Id, - Fully_Conformant, True, Conformant, Body_Id); + Fully_Conformant, True, Conformant, Body_Id); end if; -- If the body is not fully conformant, we have to decide if we @@ -1137,9 +1810,51 @@ package body Sem_Ch6 is if Nkind (N) /= N_Subprogram_Body_Stub then Set_Corresponding_Spec (N, Spec_Id); + + -- Ada 2005 (AI-345): If the operation is a primitive operation + -- of a concurrent type, the type of the first parameter has been + -- replaced with the corresponding record, which is the proper + -- run-time structure to use. However, within the body there may + -- be uses of the formals that depend on primitive operations + -- of the type (in particular calls in prefixed form) for which + -- we need the original concurrent type. The operation may have + -- several controlling formals, so the replacement must be done + -- for all of them. + + if Comes_From_Source (Spec_Id) + and then Present (First_Entity (Spec_Id)) + and then Ekind (Etype (First_Entity (Spec_Id))) = E_Record_Type + and then Is_Tagged_Type (Etype (First_Entity (Spec_Id))) + and then + Present (Abstract_Interfaces (Etype (First_Entity (Spec_Id)))) + and then + Present + (Corresponding_Concurrent_Type + (Etype (First_Entity (Spec_Id)))) + then + declare + Typ : constant Entity_Id := Etype (First_Entity (Spec_Id)); + Form : Entity_Id; + + begin + Form := First_Formal (Spec_Id); + while Present (Form) loop + if Etype (Form) = Typ then + Set_Etype (Form, Corresponding_Concurrent_Type (Typ)); + end if; + + Next_Formal (Form); + end loop; + end; + end if; + + -- Make the formals visible, and place subprogram on scope stack. + -- This is also the point at which we set Last_Real_Spec_Entity + -- to mark the entities which will not be moved to the body. + Install_Formals (Spec_Id); - Last_Formal := Last_Entity (Spec_Id); - New_Scope (Spec_Id); + Last_Real_Spec_Entity := Last_Entity (Spec_Id); + Push_Scope (Spec_Id); -- Make sure that the subprogram is immediately visible. For -- child units that have no separate spec this is indispensable. @@ -1151,6 +1866,7 @@ package body Sem_Ch6 is Set_Corresponding_Body (Unit_Declaration_Node (Spec_Id), Body_Id); Set_Ekind (Body_Id, E_Subprogram_Body); Set_Scope (Body_Id, Scope (Spec_Id)); + Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id)); -- Case of subprogram body with no previous spec @@ -1172,10 +1888,37 @@ package body Sem_Ch6 is (Body_Id, Body_Id, 'b', Set_Ref => False, Force => True); Generate_Reference_To_Formals (Body_Id); Install_Formals (Body_Id); - New_Scope (Body_Id); + Push_Scope (Body_Id); end if; end if; + -- If the return type is an anonymous access type whose designated type + -- is the limited view of a class-wide type and the non-limited view is + -- available, update the return type accordingly. + + if Ada_Version >= Ada_05 + and then Comes_From_Source (N) + then + declare + Etyp : Entity_Id; + Rtyp : Entity_Id; + + begin + Rtyp := Etype (Current_Scope); + + if Ekind (Rtyp) = E_Anonymous_Access_Type then + Etyp := Directly_Designated_Type (Rtyp); + + if Is_Class_Wide_Type (Etyp) + and then From_With_Type (Etyp) + then + Set_Directly_Designated_Type + (Etype (Current_Scope), Available_View (Etyp)); + end if; + end if; + end; + end if; + -- If this is the proper body of a stub, we must verify that the stub -- conforms to the body, and to the previous spec if one was present. -- we know already that the body conforms to that spec. This test is @@ -1219,34 +1962,93 @@ package body Sem_Ch6 is if Nkind (N) = N_Subprogram_Body_Stub then return; - elsif Present (Spec_Id) + elsif Present (Spec_Id) and then Expander_Active + and then + (Has_Pragma_Inline_Always (Spec_Id) + or else (Has_Pragma_Inline (Spec_Id) and Front_End_Inlining)) then - Check_Following_Pragma; - - if Is_Always_Inlined (Spec_Id) - or else (Has_Pragma_Inline (Spec_Id) and then Front_End_Inlining) - then - Build_Body_To_Inline (N, Spec_Id); - end if; + Build_Body_To_Inline (N, Spec_Id); end if; -- Ada 2005 (AI-262): In library subprogram bodies, after the analysis -- if its specification we have to install the private withed units. + -- This holds for child units as well. if Is_Compilation_Unit (Body_Id) - and then Scope (Body_Id) = Standard_Standard + or else Nkind (Parent (N)) = N_Compilation_Unit then Install_Private_With_Clauses (Body_Id); end if; + Check_Anonymous_Return; + + -- Set the Protected_Formal field of each extra formal of the protected + -- subprogram to reference the corresponding extra formal of the + -- subprogram that implements it. For regular formals this occurs when + -- the protected subprogram's declaration is expanded, but the extra + -- formals don't get created until the subprogram is frozen. We need to + -- do this before analyzing the protected subprogram's body so that any + -- references to the original subprogram's extra formals will be changed + -- refer to the implementing subprogram's formals (see Expand_Formal). + + if Present (Spec_Id) + and then Is_Protected_Type (Scope (Spec_Id)) + and then Present (Protected_Body_Subprogram (Spec_Id)) + then + declare + Impl_Subp : constant Entity_Id := + Protected_Body_Subprogram (Spec_Id); + Prot_Ext_Formal : Entity_Id := Extra_Formals (Spec_Id); + Impl_Ext_Formal : Entity_Id := Extra_Formals (Impl_Subp); + begin + while Present (Prot_Ext_Formal) loop + pragma Assert (Present (Impl_Ext_Formal)); + Set_Protected_Formal (Prot_Ext_Formal, Impl_Ext_Formal); + Next_Formal_With_Extras (Prot_Ext_Formal); + Next_Formal_With_Extras (Impl_Ext_Formal); + end loop; + end; + end if; + -- Now we can go on to analyze the body HSS := Handled_Statement_Sequence (N); Set_Actual_Subtypes (N, Current_Scope); + + -- Deal with preconditions and postconditions + + Process_PPCs (N, Spec_Id, Body_Id); + + -- Add a declaration for the Protection objcect, renaming declarations + -- for discriminals and privals and finally a declaration for the entry + -- family index (if applicable). This form of early expansion is done + -- when the Expander is active because Install_Private_Data_Declarations + -- references entities which were created during regular expansion. + + if Expander_Active + and then Comes_From_Source (N) + and then Present (Prot_Typ) + and then Present (Spec_Id) + and then not Is_Eliminated (Spec_Id) + then + Install_Private_Data_Declarations + (Sloc (N), Spec_Id, Prot_Typ, N, Declarations (N)); + end if; + + -- Analyze the declarations (this call will analyze the precondition + -- Check pragmas we prepended to the list, as well as the declaration + -- of the _Postconditions procedure). + Analyze_Declarations (Declarations (N)); + + -- Check completion, and analyze the statements + Check_Completion; Analyze (HSS); + + -- Deal with end of scope processing for the body + Process_End_Label (HSS, 't', Current_Scope); End_Scope; Check_Subprogram_Order (N); @@ -1259,26 +2061,46 @@ package body Sem_Ch6 is if Present (Spec_Id) then - -- If a parent unit is categorized, the context of a subunit must - -- conform to the categorization. Conversely, if a child unit is - -- categorized, the parents themselves must conform. + -- We must conform to the categorization of our spec + + Validate_Categorization_Dependency (N, Spec_Id); - if Nkind (Parent (N)) = N_Subunit then - Validate_Categorization_Dependency (N, Spec_Id); + -- And if this is a child unit, the parent units must conform - elsif Is_Child_Unit (Spec_Id) then + if Is_Child_Unit (Spec_Id) then Validate_Categorization_Dependency (Unit_Declaration_Node (Spec_Id), Spec_Id); end if; - if Present (Last_Formal) then - Set_Next_Entity - (Last_Entity (Body_Id), Next_Entity (Last_Formal)); - Set_Next_Entity (Last_Formal, Empty); + -- Here is where we move entities from the spec to the body + + -- Case where there are entities that stay with the spec + + if Present (Last_Real_Spec_Entity) then + + -- No body entities (happens when the only real spec entities + -- come from precondition and postcondition pragmas) + + if No (Last_Entity (Body_Id)) then + Set_First_Entity + (Body_Id, Next_Entity (Last_Real_Spec_Entity)); + + -- Body entities present (formals), so chain stuff past them + + else + Set_Next_Entity + (Last_Entity (Body_Id), Next_Entity (Last_Real_Spec_Entity)); + end if; + + Set_Next_Entity (Last_Real_Spec_Entity, Empty); Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); - Set_Last_Entity (Spec_Id, Last_Formal); + Set_Last_Entity (Spec_Id, Last_Real_Spec_Entity); + + -- Case where there are no spec entities, in this case there can + -- be no body entities either, so just move everything. else + pragma Assert (No (Last_Entity (Body_Id))); Set_First_Entity (Body_Id, First_Entity (Spec_Id)); Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); Set_First_Entity (Spec_Id, Empty); @@ -1319,11 +2141,16 @@ package body Sem_Ch6 is and then Present (Spec_Id) and then No_Return (Spec_Id) then - Check_Returns (HSS, 'P', Missing_Ret); + Check_Returns (HSS, 'P', Missing_Ret, Spec_Id); end if; -- Now we are going to check for variables that are never modified in - -- the body of the procedure. We omit these checks if the first + -- the body of the procedure. But first we deal with a special case + -- where we want to modify this check. If the body of the subprogram + -- starts with a raise statement or its equivalent, or if the body + -- consists entirely of a null statement, then it is pretty obvious + -- that it is OK to not reference the parameters. For example, this + -- might be the following common idiom for a stubbed function: -- statement of the procedure raises an exception. In particular this -- deals with the common idiom of a stubbed function, which might -- appear as something like @@ -1335,21 +2162,32 @@ package body Sem_Ch6 is -- return X; -- end F; - -- Here the purpose of X is simply to satisfy the (annoying) - -- requirement in Ada that there be at least one return, and we - -- certainly do not want to go posting warnings on X that it is not - -- initialized! + -- Here the purpose of X is simply to satisfy the annoying requirement + -- in Ada that there be at least one return, and we certainly do not + -- want to go posting warnings on X that it is not initialized! On + -- the other hand, if X is entirely unreferenced that should still + -- get a warning. + + -- What we do is to detect these cases, and if we find them, flag the + -- subprogram as being Is_Trivial_Subprogram and then use that flag to + -- suppress unwanted warnings. For the case of the function stub above + -- we have a special test to set X as apparently assigned to suppress + -- the warning. declare - Stm : Node_Id := First (Statements (HSS)); + Stm : Node_Id; begin - -- Skip an initial label (for one thing this occurs when we are in - -- front end ZCX mode, but in any case it is irrelevant). + -- Skip initial labels (for one thing this occurs when we are in + -- front end ZCX mode, but in any case it is irrelevant), and also + -- initial Push_xxx_Error_Label nodes, which are also irrelevant. - if Nkind (Stm) = N_Label then + Stm := First (Statements (HSS)); + while Nkind (Stm) = N_Label + or else Nkind (Stm) in N_Push_xxx_Label + loop Next (Stm); - end if; + end loop; -- Do the test on the original statement before expansion @@ -1357,10 +2195,18 @@ package body Sem_Ch6 is Ostm : constant Node_Id := Original_Node (Stm); begin - -- If explicit raise statement, return with no checks + -- If explicit raise statement, turn on flag if Nkind (Ostm) = N_Raise_Statement then - return; + Set_Trivial_Subprogram (Stm); + + -- If null statement, and no following statemennts, turn on flag + + elsif Nkind (Stm) = N_Null_Statement + and then Comes_From_Source (Stm) + and then No (Next (Stm)) + then + Set_Trivial_Subprogram (Stm); -- Check for explicit call cases which likely raise an exception @@ -1372,22 +2218,23 @@ package body Sem_Ch6 is begin -- If the procedure is marked No_Return, then likely it -- raises an exception, but in any case it is not coming - -- back here, so no need to check beyond the call. + -- back here, so turn on the flag. if Ekind (Ent) = E_Procedure and then No_Return (Ent) then - return; + Set_Trivial_Subprogram (Stm); -- If the procedure name is Raise_Exception, then also -- assume that it raises an exception. The main target -- here is Ada.Exceptions.Raise_Exception, but this name -- is pretty evocative in any context! Note that the -- procedure in Ada.Exceptions is not marked No_Return - -- because of the annoying case of the null exception Id. + -- because of the annoying case of the null exception Id + -- when operating in Ada 95 mode. elsif Chars (Ent) = Name_Raise_Exception then - return; + Set_Trivial_Subprogram (Stm); end if; end; end if; @@ -1408,7 +2255,6 @@ package body Sem_Ch6 is if Present (Spec_Id) then E1 := First_Entity (Spec_Id); - while Present (E1) loop if Ekind (E1) = E_Out_Parameter then E2 := First_Entity (Body_Id); @@ -1450,16 +2296,16 @@ package body Sem_Ch6 is begin Generate_Definition (Designator); - -- Check for RCI unit subprogram declarations against in-lined + -- Check for RCI unit subprogram declarations for illegal inlined -- subprograms and subprograms having access parameter or limited - -- parameter without Read and Write (RM E.2.3(12-13)). + -- parameter without Read and Write attributes (RM E.2.3(12-13)). Validate_RCI_Subprogram_Declaration (N); Trace_Scope (N, Defining_Entity (N), - " Analyze subprogram spec. "); + " Analyze subprogram spec: "); if Debug_Flag_C then Write_Str ("==== Compiling subprogram spec "); @@ -1472,6 +2318,50 @@ package body Sem_Ch6 is New_Overloaded_Entity (Designator); Check_Delayed_Subprogram (Designator); + -- Ada 2005 (AI-251): Abstract interface primitives must be abstract + -- or null. + + if Ada_Version >= Ada_05 + and then Comes_From_Source (N) + and then Is_Dispatching_Operation (Designator) + then + declare + E : Entity_Id; + Etyp : Entity_Id; + + begin + if Has_Controlling_Result (Designator) then + Etyp := Etype (Designator); + + else + E := First_Entity (Designator); + while Present (E) + and then Is_Formal (E) + and then not Is_Controlling_Formal (E) + loop + Next_Entity (E); + end loop; + + Etyp := Etype (E); + end if; + + if Is_Access_Type (Etyp) then + Etyp := Directly_Designated_Type (Etyp); + end if; + + if Is_Interface (Etyp) + and then not Is_Abstract_Subprogram (Designator) + and then not (Ekind (Designator) = E_Procedure + and then Null_Present (Specification (N))) + then + Error_Msg_Name_1 := Chars (Defining_Entity (N)); + Error_Msg_N + ("(Ada 2005) interface subprogram % must be abstract or null", + N); + end if; + end; + end if; + -- What is the following code for, it used to be -- ??? Set_Suppress_Elaboration_Checks @@ -1490,7 +2380,7 @@ package body Sem_Ch6 is else -- For a compilation unit, check for library-unit pragmas - New_Scope (Designator); + Push_Scope (Designator); Set_Categorization_From_Pragmas (N); Validate_Categorization_Dependency (N, Designator); Pop_Scope; @@ -1501,17 +2391,33 @@ package body Sem_Ch6 is if Nkind (Parent (N)) = N_Compilation_Unit then Set_Body_Required (Parent (N), True); + + if Ada_Version >= Ada_05 + and then Nkind (Specification (N)) = N_Procedure_Specification + and then Null_Present (Specification (N)) + then + Error_Msg_N + ("null procedure cannot be declared at library level", N); + end if; end if; Generate_Reference_To_Formals (Designator); Check_Eliminated (Designator); - if Comes_From_Source (N) - and then Is_List_Member (N) + -- Ada 2005: if procedure is declared with "is null" qualifier, + -- it requires no body. + + if Nkind (Specification (N)) = N_Procedure_Specification + and then Null_Present (Specification (N)) then - Check_Overriding_Operation (N, Designator); - end if; + Set_Has_Completion (Designator); + Set_Is_Inlined (Designator); + if Is_Protected_Type (Current_Scope) then + Error_Msg_N + ("protected operation cannot be a null procedure", N); + end if; + end if; end Analyze_Subprogram_Declaration; -------------------------------------- @@ -1525,6 +2431,10 @@ package body Sem_Ch6 is function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id is Designator : constant Entity_Id := Defining_Entity (N); Formals : constant List_Id := Parameter_Specifications (N); + Formal : Entity_Id; + Formal_Typ : Entity_Id; + + -- Start of processing for Analyze_Subprogram_Specification begin Generate_Definition (Designator); @@ -1538,14 +2448,38 @@ package body Sem_Ch6 is Set_Etype (Designator, Standard_Void_Type); end if; - -- Introduce new scope for analysis of the formals and of the - -- return type. + -- Introduce new scope for analysis of the formals and the return type Set_Scope (Designator, Current_Scope); if Present (Formals) then - New_Scope (Designator); + Push_Scope (Designator); Process_Formals (Formals, N); + + -- Ada 2005 (AI-345): Allow the overriding of interface primitives + -- by subprograms which belong to a concurrent type implementing an + -- interface. Set the parameter type of each controlling formal to + -- the corresponding record type. + + if Ada_Version >= Ada_05 then + Formal := First_Formal (Designator); + while Present (Formal) loop + Formal_Typ := Etype (Formal); + + if (Ekind (Formal_Typ) = E_Protected_Type + or else Ekind (Formal_Typ) = E_Task_Type) + and then Present (Corresponding_Record_Type (Formal_Typ)) + and then Present (Abstract_Interfaces + (Corresponding_Record_Type (Formal_Typ))) + then + Set_Etype (Formal, + Corresponding_Record_Type (Formal_Typ)); + end if; + + Formal := Next_Formal (Formal); + end loop; + end if; + End_Scope; elsif Nkind (N) = N_Function_Specification then @@ -1559,14 +2493,21 @@ package body Sem_Ch6 is May_Need_Actuals (Designator); - if Is_Abstract (Etype (Designator)) - and then Nkind (Parent (N)) - /= N_Abstract_Subprogram_Declaration - and then (Nkind (Parent (N))) - /= N_Formal_Abstract_Subprogram_Declaration - and then (Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration - or else not Is_Entity_Name (Name (Parent (N))) - or else not Is_Abstract (Entity (Name (Parent (N))))) + -- Ada 2005 (AI-251): In case of primitives associated with abstract + -- interface types the following error message will be reported later + -- (see Analyze_Subprogram_Declaration). + + if Is_Abstract_Type (Etype (Designator)) + and then not Is_Interface (Etype (Designator)) + and then Nkind (Parent (N)) /= + N_Abstract_Subprogram_Declaration + and then + (Nkind (Parent (N))) /= N_Formal_Abstract_Subprogram_Declaration + and then + (Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration + or else not Is_Entity_Name (Name (Parent (N))) + or else not Is_Abstract_Subprogram + (Entity (Name (Parent (N))))) then Error_Msg_N ("function that returns abstract type must be abstract", N); @@ -1581,7 +2522,7 @@ package body Sem_Ch6 is -------------------------- procedure Build_Body_To_Inline (N : Node_Id; Subp : Entity_Id) is - Decl : constant Node_Id := Unit_Declaration_Node (Subp); + Decl : constant Node_Id := Unit_Declaration_Node (Subp); Original_Body : Node_Id; Body_To_Analyze : Node_Id; Max_Size : constant := 10; @@ -1596,17 +2537,24 @@ package body Sem_Ch6 is -- elementary statements, as a measure of acceptable size. function Has_Pending_Instantiation return Boolean; - -- If some enclosing body contains instantiations that appear before - -- the corresponding generic body, the enclosing body has a freeze node - -- so that it can be elaborated after the generic itself. This might + -- If some enclosing body contains instantiations that appear before the + -- corresponding generic body, the enclosing body has a freeze node so + -- that it can be elaborated after the generic itself. This might -- conflict with subsequent inlinings, so that it is unsafe to try to -- inline in such a case. + function Has_Single_Return return Boolean; + -- In general we cannot inline functions that return unconstrained type. + -- However, we can handle such functions if all return statements return + -- a local variable that is the only declaration in the body of the + -- function. In that case the call can be replaced by that local + -- variable as is done for other inlined calls. + procedure Remove_Pragmas; - -- A pragma Unreferenced that mentions a formal parameter has no - -- meaning when the body is inlined and the formals are rewritten. - -- Remove it from body to inline. The analysis of the non-inlined body - -- will handle the pragma properly. + -- A pragma Unreferenced or pragma Unmodified that mentions a formal + -- parameter has no meaning when the body is inlined and the formals + -- are rewritten. Remove it from body to inline. The analysis of the + -- non-inlined body will handle the pragma properly. function Uses_Secondary_Stack (Bod : Node_Id) return Boolean; -- If the body of the subprogram includes a call that returns an @@ -1640,18 +2588,17 @@ package body Sem_Ch6 is then Conv := Current_Entity (Id); - elsif Nkind (Id) = N_Selected_Component + elsif Nkind_In (Id, N_Selected_Component, N_Expanded_Name) and then Chars (Selector_Name (Id)) = Name_Unchecked_Conversion then Conv := Current_Entity (Selector_Name (Id)); - else return False; end if; - return - Present (Conv) - and then Scope (Conv) = Standard_Standard + return Present (Conv) + and then Is_Predefined_File_Name + (Unit_File_Name (Get_Source_Unit (Conv))) and then Is_Intrinsic_Subprogram (Conv); end Is_Unchecked_Conversion; @@ -1659,16 +2606,15 @@ package body Sem_Ch6 is begin D := First (Decls); - while Present (D) loop - if (Nkind (D) = N_Function_Instantiation - and then not Is_Unchecked_Conversion (D)) - or else Nkind (D) = N_Protected_Type_Declaration - or else Nkind (D) = N_Package_Declaration - or else Nkind (D) = N_Package_Instantiation - or else Nkind (D) = N_Subprogram_Body - or else Nkind (D) = N_Procedure_Instantiation - or else Nkind (D) = N_Task_Type_Declaration + if (Nkind (D) = N_Function_Instantiation + and then not Is_Unchecked_Conversion (D)) + or else Nkind_In (D, N_Protected_Type_Declaration, + N_Package_Declaration, + N_Package_Instantiation, + N_Subprogram_Body, + N_Procedure_Instantiation, + N_Task_Type_Declaration) then Cannot_Inline ("cannot inline & (non-allowed declaration)?", D, Subp); @@ -1691,17 +2637,16 @@ package body Sem_Ch6 is begin S := First (Stats); - while Present (S) loop Stat_Count := Stat_Count + 1; - if Nkind (S) = N_Abort_Statement - or else Nkind (S) = N_Asynchronous_Select - or else Nkind (S) = N_Conditional_Entry_Call - or else Nkind (S) = N_Delay_Relative_Statement - or else Nkind (S) = N_Delay_Until_Statement - or else Nkind (S) = N_Selective_Accept - or else Nkind (S) = N_Timed_Entry_Call + if Nkind_In (S, N_Abort_Statement, + N_Asynchronous_Select, + N_Conditional_Entry_Call, + N_Delay_Relative_Statement, + N_Delay_Until_Statement, + N_Selective_Accept, + N_Timed_Entry_Call) then Cannot_Inline ("cannot inline & (non-allowed statement)?", S, Subp); @@ -1772,9 +2717,10 @@ package body Sem_Ch6 is ------------------------------- function Has_Pending_Instantiation return Boolean is - S : Entity_Id := Current_Scope; + S : Entity_Id; begin + S := Current_Scope; while Present (S) loop if Is_Compilation_Unit (S) or else Is_Child_Unit (S) @@ -1792,6 +2738,61 @@ package body Sem_Ch6 is return False; end Has_Pending_Instantiation; + ------------------------ + -- Has_Single_Return -- + ------------------------ + + function Has_Single_Return return Boolean is + Return_Statement : Node_Id := Empty; + + function Check_Return (N : Node_Id) return Traverse_Result; + + ------------------ + -- Check_Return -- + ------------------ + + function Check_Return (N : Node_Id) return Traverse_Result is + begin + if Nkind (N) = N_Simple_Return_Statement then + if Present (Expression (N)) + and then Is_Entity_Name (Expression (N)) + then + if No (Return_Statement) then + Return_Statement := N; + return OK; + + elsif Chars (Expression (N)) = + Chars (Expression (Return_Statement)) + then + return OK; + + else + return Abandon; + end if; + + else + -- Expression has wrong form + + return Abandon; + end if; + + else + return OK; + end if; + end Check_Return; + + function Check_All_Returns is new Traverse_Func (Check_Return); + + -- Start of processing for Has_Single_Return + + begin + return Check_All_Returns (N) = OK + and then Present (Declarations (N)) + and then Present (First (Declarations (N))) + and then Chars (Expression (Return_Statement)) = + Chars (Defining_Identifier (First (Declarations (N)))); + end Has_Single_Return; + -------------------- -- Remove_Pragmas -- -------------------- @@ -1806,7 +2807,9 @@ package body Sem_Ch6 is Nxt := Next (Decl); if Nkind (Decl) = N_Pragma - and then Chars (Decl) = Name_Unreferenced + and then (Pragma_Name (Decl) = Name_Unreferenced + or else + Pragma_Name (Decl) = Name_Unmodified) then Remove (Decl); end if; @@ -1857,19 +2860,24 @@ package body Sem_Ch6 is then return; -- Done already. - -- Functions that return unconstrained composite types will require - -- secondary stack handling, and cannot currently be inlined. - -- Ditto for functions that return controlled types, where controlled - -- actions interfere in complex ways with inlining. + -- Functions that return unconstrained composite types require + -- secondary stack handling, and cannot currently be inlined, unless + -- all return statements return a local variable that is the first + -- local declaration in the body. elsif Ekind (Subp) = E_Function and then not Is_Scalar_Type (Etype (Subp)) and then not Is_Access_Type (Etype (Subp)) and then not Is_Constrained (Etype (Subp)) then - Cannot_Inline - ("cannot inline & (unconstrained return type)?", N, Subp); - return; + if not Has_Single_Return then + Cannot_Inline + ("cannot inline & (unconstrained return type)?", N, Subp); + return; + end if; + + -- Ditto for functions that return controlled types, where controlled + -- actions interfere in complex ways with inlining. elsif Ekind (Subp) = E_Function and then Controlled_Type (Etype (Subp)) @@ -1905,7 +2913,7 @@ package body Sem_Ch6 is -- checks on inlining (forbidden declarations, handlers, etc). if Stat_Count > Max_Size - and then not Is_Always_Inlined (Subp) + and then not Has_Pragma_Inline_Always (Subp) then Cannot_Inline ("cannot inline& (body too large)?", N, Subp); return; @@ -1921,7 +2929,11 @@ package body Sem_Ch6 is -- Within an instance, the body to inline must be treated as a nested -- generic, so that the proper global references are preserved. - if In_Instance then + -- Note that we do not do this at the library level, because it is not + -- needed, and furthermore this causes trouble if front end inlining + -- is activated (-gnatN). + + if In_Instance and then Scope (Current_Scope) /= Standard_Standard then Save_Env (Scope (Current_Scope), Scope (Current_Scope)); Original_Body := Copy_Generic_Node (N, Empty, True); else @@ -1948,7 +2960,7 @@ package body Sem_Ch6 is -- to be resolved. if Ekind (Subp) = E_Function then - Set_Subtype_Mark (Specification (Body_To_Analyze), + Set_Result_Definition (Specification (Body_To_Analyze), New_Occurrence_Of (Etype (Subp), Sloc (N))); end if; @@ -1962,14 +2974,16 @@ package body Sem_Ch6 is Remove_Pragmas; Analyze (Body_To_Analyze); - New_Scope (Defining_Entity (Body_To_Analyze)); + Push_Scope (Defining_Entity (Body_To_Analyze)); Save_Global_References (Original_Body); End_Scope; Remove (Body_To_Analyze); Expander_Mode_Restore; - if In_Instance then + -- Restore environment if previously saved + + if In_Instance and then Scope (Current_Scope) /= Standard_Standard then Restore_Env; end if; @@ -2001,12 +3015,12 @@ package body Sem_Ch6 is then null; - elsif Is_Always_Inlined (Subp) then + elsif Has_Pragma_Inline_Always (Subp) then -- Remove last character (question mark) to make this into an error, -- because the Inline_Always pragma cannot be obeyed. - Error_Msg_NE (Msg (1 .. Msg'Length - 1), N, Subp); + Error_Msg_NE (Msg (Msg'First .. Msg'Last - 1), N, Subp); elsif Ineffective_Inline_Warnings then Error_Msg_NE (Msg, N, Subp); @@ -2018,19 +3032,15 @@ package body Sem_Ch6 is ----------------------- procedure Check_Conformance - (New_Id : Entity_Id; - Old_Id : Entity_Id; - Ctype : Conformance_Type; - Errmsg : Boolean; - Conforms : out Boolean; - Err_Loc : Node_Id := Empty; - Get_Inst : Boolean := False) + (New_Id : Entity_Id; + Old_Id : Entity_Id; + Ctype : Conformance_Type; + Errmsg : Boolean; + Conforms : out Boolean; + Err_Loc : Node_Id := Empty; + Get_Inst : Boolean := False; + Skip_Controlling_Formals : Boolean := False) is - Old_Type : constant Entity_Id := Etype (Old_Id); - New_Type : constant Entity_Id := Etype (New_Id); - Old_Formal : Entity_Id; - New_Formal : Entity_Id; - procedure Conformance_Error (Msg : String; N : Node_Id := New_Id); -- Post error message for conformance error on given node. Two messages -- are output. The first points to the previous declaration with a @@ -2064,22 +3074,50 @@ package body Sem_Ch6 is ("not type conformant with declaration#!", Enode); when Mode_Conformant => - Error_Msg_N - ("not mode conformant with declaration#!", Enode); + if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then + Error_Msg_N + ("not mode conformant with operation inherited#!", + Enode); + else + Error_Msg_N + ("not mode conformant with declaration#!", Enode); + end if; when Subtype_Conformant => - Error_Msg_N - ("not subtype conformant with declaration#!", Enode); + if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then + Error_Msg_N + ("not subtype conformant with operation inherited#!", + Enode); + else + Error_Msg_N + ("not subtype conformant with declaration#!", Enode); + end if; when Fully_Conformant => - Error_Msg_N - ("not fully conformant with declaration#!", Enode); + if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then + Error_Msg_N + ("not fully conformant with operation inherited#!", + Enode); + else + Error_Msg_N + ("not fully conformant with declaration#!", Enode); + end if; end case; Error_Msg_NE (Msg, Enode, N); end if; end Conformance_Error; + -- Local Variables + + Old_Type : constant Entity_Id := Etype (Old_Id); + New_Type : constant Entity_Id := Etype (New_Id); + Old_Formal : Entity_Id; + New_Formal : Entity_Id; + Access_Types_Match : Boolean; + Old_Formal_Base : Entity_Id; + New_Formal_Base : Entity_Id; + -- Start of processing for Check_Conformance begin @@ -2102,7 +3140,22 @@ package body Sem_Ch6 is and then New_Type /= Standard_Void_Type then if not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then - Conformance_Error ("return type does not match!", New_Id); + Conformance_Error ("\return type does not match!", New_Id); + return; + end if; + + -- Ada 2005 (AI-231): In case of anonymous access types check the + -- null-exclusion and access-to-constant attributes match. + + if Ada_Version >= Ada_05 + and then Ekind (Etype (Old_Type)) = E_Anonymous_Access_Type + and then + (Can_Never_Be_Null (Old_Type) + /= Can_Never_Be_Null (New_Type) + or else Is_Access_Constant (Etype (Old_Type)) + /= Is_Access_Constant (Etype (New_Type))) + then + Conformance_Error ("\return type does not match!", New_Id); return; end if; @@ -2111,11 +3164,11 @@ package body Sem_Ch6 is elsif Old_Type /= Standard_Void_Type or else New_Type /= Standard_Void_Type then - Conformance_Error ("functions can only match functions!", New_Id); + Conformance_Error ("\functions can only match functions!", New_Id); return; end if; - -- In subtype conformant case, conventions must match (RM 6.3.1(16)) + -- In subtype conformant case, conventions must match (RM 6.3.1(16)). -- If this is a renaming as body, refine error message to indicate that -- the conflict is with the original declaration. If the entity is not -- frozen, the conventions don't have to match, the one of the renamed @@ -2135,10 +3188,10 @@ package body Sem_Ch6 is Error_Msg_Name_2 := Name_Ada + Convention_Id'Pos (Convention (New_Id)); - Conformance_Error ("prior declaration for% has convention %!"); + Conformance_Error ("\prior declaration for% has convention %!"); else - Conformance_Error ("calling conventions do not match!"); + Conformance_Error ("\calling conventions do not match!"); end if; return; @@ -2146,7 +3199,7 @@ package body Sem_Ch6 is elsif Is_Formal_Subprogram (Old_Id) or else Is_Formal_Subprogram (New_Id) then - Conformance_Error ("formal subprograms not allowed!"); + Conformance_Error ("\formal subprograms not allowed!"); return; end if; end if; @@ -2162,13 +3215,20 @@ package body Sem_Ch6 is New_Formal := First_Formal (New_Id); while Present (Old_Formal) and then Present (New_Formal) loop + if Is_Controlling_Formal (Old_Formal) + and then Is_Controlling_Formal (New_Formal) + and then Skip_Controlling_Formals + then + goto Skip_Controlling_Formal; + end if; + if Ctype = Fully_Conformant then -- Names must match. Error message is more accurate if we do -- this before checking that the types of the formals match. if Chars (Old_Formal) /= Chars (New_Formal) then - Conformance_Error ("name & does not match!", New_Formal); + Conformance_Error ("\name & does not match!", New_Formal); -- Set error posted flag on new formal as well to stop -- junk cascaded messages in some cases. @@ -2178,6 +3238,73 @@ package body Sem_Ch6 is end if; end if; + -- Ada 2005 (AI-423): Possible access [sub]type and itype match. This + -- case occurs whenever a subprogram is being renamed and one of its + -- parameters imposes a null exclusion. For example: + + -- type T is null record; + -- type Acc_T is access T; + -- subtype Acc_T_Sub is Acc_T; + + -- procedure P (Obj : not null Acc_T_Sub); -- itype + -- procedure Ren_P (Obj : Acc_T_Sub) -- subtype + -- renames P; + + Old_Formal_Base := Etype (Old_Formal); + New_Formal_Base := Etype (New_Formal); + + if Get_Inst then + Old_Formal_Base := Get_Instance_Of (Old_Formal_Base); + New_Formal_Base := Get_Instance_Of (New_Formal_Base); + end if; + + Access_Types_Match := Ada_Version >= Ada_05 + + -- Ensure that this rule is only applied when New_Id is a + -- renaming of Old_Id. + + and then Nkind (Parent (Parent (New_Id))) = + N_Subprogram_Renaming_Declaration + and then Nkind (Name (Parent (Parent (New_Id)))) in N_Has_Entity + and then Present (Entity (Name (Parent (Parent (New_Id))))) + and then Entity (Name (Parent (Parent (New_Id)))) = Old_Id + + -- Now handle the allowed access-type case + + and then Is_Access_Type (Old_Formal_Base) + and then Is_Access_Type (New_Formal_Base) + + -- The type kinds must match. The only exception occurs with + -- multiple generics of the form: + + -- generic generic + -- type F is private; type A is private; + -- type F_Ptr is access F; type A_Ptr is access A; + -- with proc F_P (X : F_Ptr); with proc A_P (X : A_Ptr); + -- package F_Pack is ... package A_Pack is + -- package F_Inst is + -- new F_Pack (A, A_Ptr, A_P); + + -- When checking for conformance between the parameters of A_P + -- and F_P, the type kinds of F_Ptr and A_Ptr will not match + -- because the compiler has transformed A_Ptr into a subtype of + -- F_Ptr. We catch this case in the code below. + + and then (Ekind (Old_Formal_Base) = Ekind (New_Formal_Base) + or else + (Is_Generic_Type (Old_Formal_Base) + and then Is_Generic_Type (New_Formal_Base) + and then Is_Internal (New_Formal_Base) + and then Etype (Etype (New_Formal_Base)) = + Old_Formal_Base)) + and then Directly_Designated_Type (Old_Formal_Base) = + Directly_Designated_Type (New_Formal_Base) + and then ((Is_Itype (Old_Formal_Base) + and then Can_Never_Be_Null (Old_Formal_Base)) + or else + (Is_Itype (New_Formal_Base) + and then Can_Never_Be_Null (New_Formal_Base))); + -- Types must always match. In the visible part of an instance, -- usual overloading rules for dispatching operations apply, and -- we check base types (not the actual subtypes). @@ -2186,37 +3313,93 @@ package body Sem_Ch6 is and then Is_Dispatching_Operation (New_Id) then if not Conforming_Types - (Base_Type (Etype (Old_Formal)), - Base_Type (Etype (New_Formal)), Ctype, Get_Inst) + (T1 => Base_Type (Etype (Old_Formal)), + T2 => Base_Type (Etype (New_Formal)), + Ctype => Ctype, + Get_Inst => Get_Inst) + and then not Access_Types_Match then - Conformance_Error ("type of & does not match!", New_Formal); + Conformance_Error ("\type of & does not match!", New_Formal); return; end if; elsif not Conforming_Types - (Etype (Old_Formal), Etype (New_Formal), Ctype, Get_Inst) + (T1 => Old_Formal_Base, + T2 => New_Formal_Base, + Ctype => Ctype, + Get_Inst => Get_Inst) + and then not Access_Types_Match then - Conformance_Error ("type of & does not match!", New_Formal); + Conformance_Error ("\type of & does not match!", New_Formal); return; end if; -- For mode conformance, mode must match - if Ctype >= Mode_Conformant - and then Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal) - then - Conformance_Error ("mode of & does not match!", New_Formal); - return; + if Ctype >= Mode_Conformant then + if Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal) then + Conformance_Error ("\mode of & does not match!", New_Formal); + return; + + -- Part of mode conformance for access types is having the same + -- constant modifier. + + elsif Access_Types_Match + and then Is_Access_Constant (Old_Formal_Base) /= + Is_Access_Constant (New_Formal_Base) + then + Conformance_Error + ("\constant modifier does not match!", New_Formal); + return; + end if; + end if; + + if Ctype >= Subtype_Conformant then + + -- Ada 2005 (AI-231): In case of anonymous access types check + -- the null-exclusion and access-to-constant attributes must + -- match. + + if Ada_Version >= Ada_05 + and then Ekind (Etype (Old_Formal)) = E_Anonymous_Access_Type + and then Ekind (Etype (New_Formal)) = E_Anonymous_Access_Type + and then + (Can_Never_Be_Null (Old_Formal) /= + Can_Never_Be_Null (New_Formal) + or else + Is_Access_Constant (Etype (Old_Formal)) /= + Is_Access_Constant (Etype (New_Formal))) + then + -- It is allowed to omit the null-exclusion in case of stream + -- attribute subprograms. We recognize stream subprograms + -- through their TSS-generated suffix. + + declare + TSS_Name : constant TSS_Name_Type := Get_TSS_Name (New_Id); + begin + if TSS_Name /= TSS_Stream_Read + and then TSS_Name /= TSS_Stream_Write + and then TSS_Name /= TSS_Stream_Input + and then TSS_Name /= TSS_Stream_Output + then + Conformance_Error + ("\type of & does not match!", New_Formal); + return; + end if; + end; + end if; end if; -- Full conformance checks if Ctype = Fully_Conformant then - -- We have checked already that names match. Check default - -- expressions for in parameters + -- We have checked already that names match if Parameter_Mode (Old_Formal) = E_In_Parameter then + + -- Check default expressions for in parameters + declare NewD : constant Boolean := Present (Default_Value (New_Formal)); @@ -2227,13 +3410,12 @@ package body Sem_Ch6 is -- The old default value has been analyzed because the -- current full declaration will have frozen everything - -- before. The new default values have not been - -- analyzed, so analyze them now before we check for - -- conformance. + -- before. The new default value has not been analyzed, + -- so analyze it now before we check for conformance. if NewD then - New_Scope (New_Id); - Analyze_Per_Use_Expression + Push_Scope (New_Id); + Preanalyze_Spec_Expression (Default_Value (New_Formal), Etype (New_Formal)); End_Scope; end if; @@ -2244,7 +3426,7 @@ package body Sem_Ch6 is Default_Value (New_Formal)) then Conformance_Error - ("default expression for & does not match!", + ("\default expression for & does not match!", New_Formal); return; end if; @@ -2254,7 +3436,7 @@ package body Sem_Ch6 is end if; -- A couple of special checks for Ada 83 mode. These checks are - -- skipped if either entity is an operator in package Standard. + -- skipped if either entity is an operator in package Standard, -- or if either old or new instance is not from the source program. if Ada_Version = Ada_83 @@ -2275,7 +3457,7 @@ package body Sem_Ch6 is and then Ctype = Fully_Conformant then Conformance_Error - ("(Ada 83) IN must appear in both declarations", + ("\(Ada 83) IN must appear in both declarations", New_Formal); return; end if; @@ -2283,7 +3465,7 @@ package body Sem_Ch6 is -- Grouping (use of comma in param lists) must be the same -- This is where we catch a misconformance like: - -- A,B : Integer + -- A, B : Integer -- A : Integer; B : Integer -- which are represented identically in the tree except @@ -2293,26 +3475,168 @@ package body Sem_Ch6 is or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param) then Conformance_Error - ("grouping of & does not match!", New_Formal); + ("\grouping of & does not match!", New_Formal); return; end if; end; end if; - Next_Formal (Old_Formal); - Next_Formal (New_Formal); - end loop; + -- This label is required when skipping controlling formals + + <> + + Next_Formal (Old_Formal); + Next_Formal (New_Formal); + end loop; + + if Present (Old_Formal) then + Conformance_Error ("\too few parameters!"); + return; + + elsif Present (New_Formal) then + Conformance_Error ("\too many parameters!", New_Formal); + return; + end if; + end Check_Conformance; + + ----------------------- + -- Check_Conventions -- + ----------------------- + + procedure Check_Conventions (Typ : Entity_Id) is + + function Skip_Check (Op : Entity_Id) return Boolean; + pragma Inline (Skip_Check); + -- A small optimization: skip the predefined dispatching operations, + -- since they always have the same convention. Also do not consider + -- abstract primitives since those are left by an erroneous overriding. + -- This function returns True for any operation that is thus exempted + -- exempted from checking. + + procedure Check_Convention + (Op : Entity_Id; + Search_From : Elmt_Id); + -- Verify that the convention of inherited dispatching operation Op is + -- consistent among all subprograms it overrides. In order to minimize + -- the search, Search_From is utilized to designate a specific point in + -- the list rather than iterating over the whole list once more. + + ---------------------- + -- Check_Convention -- + ---------------------- + + procedure Check_Convention + (Op : Entity_Id; + Search_From : Elmt_Id) + is + procedure Error_Msg_Operation (Op : Entity_Id); + -- Emit a continuation to an error message depicting the kind, name, + -- convention and source location of subprogram Op. + + ------------------------- + -- Error_Msg_Operation -- + ------------------------- + + procedure Error_Msg_Operation (Op : Entity_Id) is + begin + Error_Msg_Name_1 := Chars (Op); + + -- Error messages of primitive subprograms do not contain a + -- convention attribute since the convention may have been first + -- inherited from a parent subprogram, then changed by a pragma. + + if Comes_From_Source (Op) then + Error_Msg_Sloc := Sloc (Op); + Error_Msg_N + ("\ primitive % defined #", Typ); + + else + Error_Msg_Name_2 := Get_Convention_Name (Convention (Op)); + + if Present (Abstract_Interface_Alias (Op)) then + Error_Msg_Sloc := Sloc (Abstract_Interface_Alias (Op)); + Error_Msg_N ("\\overridden operation % with " & + "convention % defined #", Typ); + + else pragma Assert (Present (Alias (Op))); + Error_Msg_Sloc := Sloc (Alias (Op)); + Error_Msg_N ("\\inherited operation % with " & + "convention % defined #", Typ); + end if; + end if; + end Error_Msg_Operation; + + -- Local variables + + Second_Prim_Op : Entity_Id; + Second_Prim_Op_Elmt : Elmt_Id; + + -- Start of processing for Check_Convention + + begin + Second_Prim_Op_Elmt := Next_Elmt (Search_From); + while Present (Second_Prim_Op_Elmt) loop + Second_Prim_Op := Node (Second_Prim_Op_Elmt); + + if not Skip_Check (Second_Prim_Op) + and then Chars (Second_Prim_Op) = Chars (Op) + and then Type_Conformant (Second_Prim_Op, Op) + and then Convention (Second_Prim_Op) /= Convention (Op) + then + Error_Msg_N + ("inconsistent conventions in primitive operations", Typ); + + Error_Msg_Operation (Op); + Error_Msg_Operation (Second_Prim_Op); + + -- Avoid cascading errors + + return; + end if; + + Next_Elmt (Second_Prim_Op_Elmt); + end loop; + end Check_Convention; + + ---------------- + -- Skip_Check -- + ---------------- - if Present (Old_Formal) then - Conformance_Error ("too few parameters!"); - return; + function Skip_Check (Op : Entity_Id) return Boolean is + begin + return Is_Predefined_Dispatching_Operation (Op) + or else Is_Abstract_Subprogram (Op); + end Skip_Check; - elsif Present (New_Formal) then - Conformance_Error ("too many parameters!", New_Formal); - return; - end if; + -- Local variables - end Check_Conformance; + Prim_Op : Entity_Id; + Prim_Op_Elmt : Elmt_Id; + + -- Start of processing for Check_Conventions + + begin + -- The algorithm checks every overriding dispatching operation against + -- all the corresponding overridden dispatching operations, detecting + -- differences in coventions. + + Prim_Op_Elmt := First_Elmt (Primitive_Operations (Typ)); + while Present (Prim_Op_Elmt) loop + Prim_Op := Node (Prim_Op_Elmt); + + -- A small optimization: skip the predefined dispatching operations + -- since they always have the same convention. Also avoid processing + -- of abstract primitives left from an erroneous overriding. + + if not Skip_Check (Prim_Op) then + Check_Convention + (Op => Prim_Op, + Search_From => Prim_Op_Elmt); + end if; + + Next_Elmt (Prim_Op_Elmt); + end loop; + end Check_Conventions; ------------------------------ -- Check_Delayed_Subprogram -- @@ -2350,7 +3674,9 @@ package body Sem_Ch6 is begin -- Never need to freeze abstract subprogram - if Is_Abstract (Designator) then + if Ekind (Designator) /= E_Subprogram_Type + and then Is_Abstract_Subprogram (Designator) + then null; else -- Need delayed freeze if return type itself needs a delayed @@ -2382,10 +3708,10 @@ package body Sem_Ch6 is Utyp : constant Entity_Id := Underlying_Type (Typ); begin - if Is_Return_By_Reference_Type (Typ) then + if Is_Inherently_Limited_Type (Typ) then Set_Returns_By_Ref (Designator); - elsif Present (Utyp) and then Controlled_Type (Utyp) then + elsif Present (Utyp) and then CW_Or_Controlled_Type (Utyp) then Set_Returns_By_Ref (Designator); end if; end; @@ -2483,7 +3809,7 @@ package body Sem_Ch6 is -- expanded, so expand now to check conformance. if NewD then - Analyze_Per_Use_Expression + Preanalyze_Spec_Expression (Expression (New_Discr), New_Discr_Type); end if; @@ -2552,7 +3878,7 @@ package body Sem_Ch6 is Err_Loc : Node_Id := Empty) is Result : Boolean; - + pragma Warnings (Off, Result); begin Check_Conformance (New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc); @@ -2569,116 +3895,143 @@ package body Sem_Ch6 is Get_Inst : Boolean := False) is Result : Boolean; - + pragma Warnings (Off, Result); begin Check_Conformance (New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst); end Check_Mode_Conformant; -------------------------------- - -- Check_Overriding_Operation -- + -- Check_Overriding_Indicator -- -------------------------------- - procedure Check_Overriding_Operation - (N : Node_Id; - Subp : Entity_Id) + procedure Check_Overriding_Indicator + (Subp : Entity_Id; + Overridden_Subp : Entity_Id; + Is_Primitive : Boolean) is - Arg1 : Node_Id; - Decl : Node_Id; - Has_Pragma : Boolean := False; + Decl : Node_Id; + Spec : Node_Id; begin - -- See whether there is an overriding pragma immediately following - -- the declaration. Intervening pragmas, such as Inline, are allowed. - - Decl := Next (N); - while Present (Decl) - and then Nkind (Decl) = N_Pragma - loop - if Chars (Decl) = Name_Overriding - or else Chars (Decl) = Name_Optional_Overriding - then - -- For now disable the use of these pragmas, until the ARG - -- finalizes the design of this feature. + -- No overriding indicator for literals - Error_Msg_N ("?unrecognized pragma", Decl); + if Ekind (Subp) = E_Enumeration_Literal then + return; - if not Is_Overriding_Operation (Subp) then + elsif Ekind (Subp) = E_Entry then + Decl := Parent (Subp); - -- Before emitting an error message, check whether this - -- may override an operation that is not yet visible, as - -- in the case of a derivation of a private operation in - -- a child unit. Such an operation is introduced with a - -- different name, but its alias is the parent operation. + else + Decl := Unit_Declaration_Node (Subp); + end if; - declare - E : Entity_Id; + if Nkind_In (Decl, N_Subprogram_Body, + N_Subprogram_Body_Stub, + N_Subprogram_Declaration, + N_Abstract_Subprogram_Declaration, + N_Subprogram_Renaming_Declaration) + then + Spec := Specification (Decl); - begin - E := First_Entity (Current_Scope); + elsif Nkind (Decl) = N_Entry_Declaration then + Spec := Decl; - while Present (E) loop - if Ekind (E) = Ekind (Subp) - and then not Comes_From_Source (E) - and then Present (Alias (E)) - and then Chars (Alias (E)) = Chars (Subp) - and then In_Open_Scopes (Scope (Alias (E))) - then - exit; - else - Next_Entity (E); - end if; - end loop; + else + return; + end if; - if No (E) then - Error_Msg_NE - ("& must override an inherited operation", - Decl, Subp); - end if; - end; + if Present (Overridden_Subp) then + if Must_Not_Override (Spec) then + Error_Msg_Sloc := Sloc (Overridden_Subp); + + if Ekind (Subp) = E_Entry then + Error_Msg_NE + ("entry & overrides inherited operation #", Spec, Subp); + else + Error_Msg_NE + ("subprogram & overrides inherited operation #", Spec, Subp); end if; - -- Verify syntax of pragma + elsif Is_Subprogram (Subp) then + Set_Is_Overriding_Operation (Subp); + end if; - Arg1 := First (Pragma_Argument_Associations (Decl)); + -- If Subp is an operator, it may override a predefined operation. + -- In that case overridden_subp is empty because of our implicit + -- representation for predefined operators. We have to check whether the + -- signature of Subp matches that of a predefined operator. Note that + -- first argument provides the name of the operator, and the second + -- argument the signature that may match that of a standard operation. + -- If the indicator is overriding, then the operator must match a + -- predefined signature, because we know already that there is no + -- explicit overridden operation. - if Present (Arg1) then - if not Is_Entity_Name (Expression (Arg1)) then - Error_Msg_N ("pragma applies to local subprogram", Decl); + elsif Nkind (Subp) = N_Defining_Operator_Symbol then - elsif Chars (Expression (Arg1)) /= Chars (Subp) then - Error_Msg_N - ("pragma must apply to preceding subprogram", Decl); + if Must_Not_Override (Spec) then + if not Is_Primitive then + Error_Msg_N + ("overriding indicator only allowed " + & "if subprogram is primitive", Subp); - elsif Present (Next (Arg1)) then - Error_Msg_N ("illegal pragma format", Decl); - end if; + elsif Operator_Matches_Spec (Subp, Subp) then + Error_Msg_NE + ("subprogram & overrides predefined operator ", Spec, Subp); end if; - Set_Analyzed (Decl); - Has_Pragma := True; - exit; + elsif Is_Overriding_Operation (Subp) then + null; + + elsif Must_Override (Spec) then + if not Operator_Matches_Spec (Subp, Subp) then + Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); + + else + Set_Is_Overriding_Operation (Subp); + end if; end if; - Next (Decl); - end loop; + elsif Must_Override (Spec) then + if Ekind (Subp) = E_Entry then + Error_Msg_NE ("entry & is not overriding", Spec, Subp); + else + Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); + end if; - if not Has_Pragma - and then Explicit_Overriding - and then Is_Overriding_Operation (Subp) + -- If the operation is marked "not overriding" and it's not primitive + -- then an error is issued, unless this is an operation of a task or + -- protected type (RM05-8.3.1(3/2-4/2)). Error cases where "overriding" + -- has been specified have already been checked above. + + elsif Must_Not_Override (Spec) + and then not Is_Primitive + and then Ekind (Subp) /= E_Entry + and then Ekind (Scope (Subp)) /= E_Protected_Type then - Error_Msg_NE ("Missing overriding pragma for&", Subp, Subp); + Error_Msg_N + ("overriding indicator only allowed if subprogram is primitive", + Subp); + return; end if; - end Check_Overriding_Operation; + end Check_Overriding_Indicator; ------------------- -- Check_Returns -- ------------------- + -- Note: this procedure needs to know far too much about how the expander + -- messes with exceptions. The use of the flag Exception_Junk and the + -- incorporation of knowledge of Exp_Ch11.Expand_Local_Exception_Handlers + -- works, but is not very clean. It would be better if the expansion + -- routines would leave Original_Node working nicely, and we could use + -- Original_Node here to ignore all the peculiar expander messing ??? + procedure Check_Returns (HSS : Node_Id; Mode : Character; - Err : out Boolean) + Err : out Boolean; + Proc : Entity_Id := Empty) is Handler : Node_Id; @@ -2693,6 +4046,7 @@ package body Sem_Ch6 is procedure Check_Statement_Sequence (L : List_Id) is Last_Stm : Node_Id; + Stm : Node_Id; Kind : Node_Kind; Raise_Exception_Call : Boolean; @@ -2706,6 +4060,65 @@ package body Sem_Ch6 is Last_Stm := Last (L); + -- Deal with digging out exception handler statement sequences that + -- have been transformed by the local raise to goto optimization. + -- See Exp_Ch11.Expand_Local_Exception_Handlers for details. If this + -- optimization has occurred, we are looking at something like: + + -- begin + -- original stmts in block + + -- exception \ + -- when excep1 => | + -- goto L1; | omitted if No_Exception_Propagation + -- when excep2 => | + -- goto L2; / + -- end; + + -- goto L3; -- skip handler when exception not raised + + -- <> -- target label for local exception + -- begin + -- estmts1 + -- end; + + -- goto L3; + + -- <> + -- begin + -- estmts2 + -- end; + + -- <> + + -- and what we have to do is to dig out the estmts1 and estmts2 + -- sequences (which were the original sequences of statements in + -- the exception handlers) and check them. + + if Nkind (Last_Stm) = N_Label + and then Exception_Junk (Last_Stm) + then + Stm := Last_Stm; + loop + Prev (Stm); + exit when No (Stm); + exit when Nkind (Stm) /= N_Block_Statement; + exit when not Exception_Junk (Stm); + Prev (Stm); + exit when No (Stm); + exit when Nkind (Stm) /= N_Label; + exit when not Exception_Junk (Stm); + Check_Statement_Sequence + (Statements (Handled_Statement_Sequence (Next (Stm)))); + + Prev (Stm); + Last_Stm := Stm; + exit when No (Stm); + exit when Nkind (Stm) /= N_Goto_Statement; + exit when not Exception_Junk (Stm); + end loop; + end if; + -- Don't count pragmas while Nkind (Last_Stm) = N_Pragma @@ -2722,10 +4135,12 @@ package body Sem_Ch6 is -- Don't count exception junk or else - ((Nkind (Last_Stm) = N_Goto_Statement - or else Nkind (Last_Stm) = N_Label - or else Nkind (Last_Stm) = N_Object_Declaration) - and then Exception_Junk (Last_Stm)) + (Nkind_In (Last_Stm, N_Goto_Statement, + N_Label, + N_Object_Declaration) + and then Exception_Junk (Last_Stm)) + or else Nkind (Last_Stm) in N_Push_xxx_Label + or else Nkind (Last_Stm) in N_Pop_xxx_Label loop Prev (Last_Stm); end loop; @@ -2755,6 +4170,9 @@ package body Sem_Ch6 is -- missing return curious, and raising Program_Error does not -- seem such a bad behavior if this does occur. + -- Note that in the Ada 2005 case for Raise_Exception, the actual + -- behavior will be to raise Constraint_Error (see AI-329). + if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception) or else Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence) @@ -2768,7 +4186,6 @@ package body Sem_Ch6 is declare Arg : constant Node_Id := Original_Node (First_Actual (Last_Stm)); - begin if Nkind (Arg) = N_Attribute_Reference and then Attribute_Name (Arg) = Name_Identity @@ -2806,7 +4223,6 @@ package body Sem_Ch6 is elsif Kind = N_Case_Statement then declare Case_Alt : Node_Id; - begin Case_Alt := First_Non_Pragma (Alternatives (Last_Stm)); while Present (Case_Alt) loop @@ -2923,13 +4339,12 @@ package body Sem_Ch6 is -- If we fall through, issue appropriate message if Mode = 'F' then - if not Raise_Exception_Call then Error_Msg_N ("?RETURN statement missing following this statement!", Last_Stm); Error_Msg_N - ("\?Program_Error may be raised at run time", + ("\?Program_Error may be raised at run time!", Last_Stm); end if; @@ -2940,10 +4355,27 @@ package body Sem_Ch6 is Err := True; + -- Otherwise we have the case of a procedure marked No_Return + else - Error_Msg_N - ("implied return after this statement not allowed (No_Return)", - Last_Stm); + if not Raise_Exception_Call then + Error_Msg_N + ("?implied return after this statement " & + "will raise Program_Error", + Last_Stm); + Error_Msg_NE + ("\?procedure & is marked as No_Return!", + Last_Stm, Proc); + end if; + + declare + RE : constant Node_Id := + Make_Raise_Program_Error (Sloc (Last_Stm), + Reason => PE_Implicit_Return); + begin + Insert_After (Last_Stm, RE); + Analyze (RE); + end; end if; end Check_Statement_Sequence; @@ -3068,6 +4500,7 @@ package body Sem_Ch6 is Err_Loc : Node_Id := Empty) is Result : Boolean; + pragma Warnings (Off, Result); begin Check_Conformance (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc); @@ -3083,6 +4516,7 @@ package body Sem_Ch6 is Err_Loc : Node_Id := Empty) is Result : Boolean; + pragma Warnings (Off, Result); begin Check_Conformance (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc); @@ -3103,13 +4537,26 @@ package body Sem_Ch6 is Are_Anonymous_Access_To_Subprogram_Types : Boolean := False; function Base_Types_Match (T1, T2 : Entity_Id) return Boolean; - -- If neither T1 nor T2 are generic actual types, or if they are - -- in different scopes (e.g. parent and child instances), then verify - -- that the base types are equal. Otherwise T1 and T2 must be - -- on the same subtype chain. The whole purpose of this procedure - -- is to prevent spurious ambiguities in an instantiation that may - -- arise if two distinct generic types are instantiated with the - -- same actual. + -- If neither T1 nor T2 are generic actual types, or if they are in + -- different scopes (e.g. parent and child instances), then verify that + -- the base types are equal. Otherwise T1 and T2 must be on the same + -- subtype chain. The whole purpose of this procedure is to prevent + -- spurious ambiguities in an instantiation that may arise if two + -- distinct generic types are instantiated with the same actual. + + function Find_Designated_Type (T : Entity_Id) return Entity_Id; + -- An access parameter can designate an incomplete type. If the + -- incomplete type is the limited view of a type from a limited_ + -- with_clause, check whether the non-limited view is available. If + -- it is a (non-limited) incomplete type, get the full view. + + function Matches_Limited_With_View (T1, T2 : Entity_Id) return Boolean; + -- Returns True if and only if either T1 denotes a limited view of T2 + -- or T2 denotes a limited view of T1. This can arise when the limited + -- with view of a type is used in a subprogram declaration and the + -- subprogram body is in the scope of a regular with clause for the + -- same unit. In such a case, the two type entities can be considered + -- identical for purposes of conformance checking. ---------------------- -- Base_Types_Match -- @@ -3122,7 +4569,7 @@ package body Sem_Ch6 is elsif Base_Type (T1) = Base_Type (T2) then - -- The following is too permissive. A more precise test must + -- The following is too permissive. A more precise test should -- check that the generic actual is an ancestor subtype of the -- other ???. @@ -3130,21 +4577,66 @@ package body Sem_Ch6 is or else not Is_Generic_Actual_Type (T2) or else Scope (T1) /= Scope (T2); - -- In some cases a type imported through a limited_with clause, - -- and its non-limited view are both visible, for example in an - -- anonymous access_to_classwide type in a formal. Both entities - -- designate the same type. + else + return False; + end if; + end Base_Types_Match; + + -------------------------- + -- Find_Designated_Type -- + -------------------------- + + function Find_Designated_Type (T : Entity_Id) return Entity_Id is + Desig : Entity_Id; - elsif From_With_Type (T1) - and then Ekind (T1) = E_Incomplete_Type - and then T2 = Non_Limited_View (T1) + begin + Desig := Directly_Designated_Type (T); + + if Ekind (Desig) = E_Incomplete_Type then + + -- If regular incomplete type, get full view if available + + if Present (Full_View (Desig)) then + Desig := Full_View (Desig); + + -- If limited view of a type, get non-limited view if available, + -- and check again for a regular incomplete type. + + elsif Present (Non_Limited_View (Desig)) then + Desig := Get_Full_View (Non_Limited_View (Desig)); + end if; + end if; + + return Desig; + end Find_Designated_Type; + + ------------------------------- + -- Matches_Limited_With_View -- + ------------------------------- + + function Matches_Limited_With_View (T1, T2 : Entity_Id) return Boolean is + begin + -- In some cases a type imported through a limited_with clause, and + -- its nonlimited view are both visible, for example in an anonymous + -- access-to-class-wide type in a formal. Both entities designate the + -- same type. + + if From_With_Type (T1) + and then T2 = Available_View (T1) + then + return True; + + elsif From_With_Type (T2) + and then T1 = Available_View (T2) then return True; else return False; end if; - end Base_Types_Match; + end Matches_Limited_With_View; + + -- Start of processing for Conforming_Types begin -- The context is an instance association for a formal @@ -3157,9 +4649,13 @@ package body Sem_Ch6 is Type_2 := Get_Instance_Of (T2); end if; - -- First see if base types match + -- If one of the types is a view of the other introduced by a limited + -- with clause, treat these as conforming for all purposes. - if Base_Types_Match (Type_1, Type_2) then + if Matches_Limited_With_View (T1, T2) then + return True; + + elsif Base_Types_Match (Type_1, Type_2) then return Ctype <= Mode_Conformant or else Subtypes_Statically_Match (Type_1, Type_2); @@ -3186,37 +4682,24 @@ package body Sem_Ch6 is or else Subtypes_Statically_Match (Type_1, Full_View (Type_2)); end if; - -- Ada 2005 (AI-254): Detect anonymous access to subprogram types + -- Ada 2005 (AI-254): Anonymous access-to-subprogram types must be + -- treated recursively because they carry a signature. Are_Anonymous_Access_To_Subprogram_Types := - - -- Case 1: Anonymous access to subprogram types - - (Ekind (Type_1) = E_Anonymous_Access_Subprogram_Type - and then Ekind (Type_2) = E_Anonymous_Access_Subprogram_Type) - - -- Case 2: Anonymous access to PROTECTED subprogram types. In this - -- case the anonymous type_declaration has been replaced by an - -- occurrence of an internal access to subprogram type declaration - -- available through the Original_Access_Type attribute - - or else - (Ekind (Type_1) = E_Access_Protected_Subprogram_Type - and then Ekind (Type_2) = E_Access_Protected_Subprogram_Type - and then not Comes_From_Source (Type_1) - and then not Comes_From_Source (Type_2) - and then Present (Original_Access_Type (Type_1)) - and then Present (Original_Access_Type (Type_2)) - and then Ekind (Original_Access_Type (Type_1)) = - E_Anonymous_Access_Protected_Subprogram_Type - and then Ekind (Original_Access_Type (Type_2)) = - E_Anonymous_Access_Protected_Subprogram_Type); + Ekind (Type_1) = Ekind (Type_2) + and then + (Ekind (Type_1) = E_Anonymous_Access_Subprogram_Type + or else + Ekind (Type_1) = E_Anonymous_Access_Protected_Subprogram_Type); -- Test anonymous access type case. For this case, static subtype - -- matching is required for mode conformance (RM 6.3.1(15)) + -- matching is required for mode conformance (RM 6.3.1(15)). We check + -- the base types because we may have built internal subtype entities + -- to handle null-excluding types (see Process_Formals). - if (Ekind (Type_1) = E_Anonymous_Access_Type - and then Ekind (Type_2) = E_Anonymous_Access_Type) + if (Ekind (Base_Type (Type_1)) = E_Anonymous_Access_Type + and then + Ekind (Base_Type (Type_2)) = E_Anonymous_Access_Type) or else Are_Anonymous_Access_To_Subprogram_Types -- Ada 2005 (AI-254) then declare @@ -3224,25 +4707,22 @@ package body Sem_Ch6 is Desig_2 : Entity_Id; begin - Desig_1 := Directly_Designated_Type (Type_1); + -- In Ada2005, access constant indicators must match for + -- subtype conformance. - -- An access parameter can designate an incomplete type - - if Ekind (Desig_1) = E_Incomplete_Type - and then Present (Full_View (Desig_1)) + if Ada_Version >= Ada_05 + and then Ctype >= Subtype_Conformant + and then + Is_Access_Constant (Type_1) /= Is_Access_Constant (Type_2) then - Desig_1 := Full_View (Desig_1); + return False; end if; - Desig_2 := Directly_Designated_Type (Type_2); + Desig_1 := Find_Designated_Type (Type_1); - if Ekind (Desig_2) = E_Incomplete_Type - and then Present (Full_View (Desig_2)) - then - Desig_2 := Full_View (Desig_2); - end if; + Desig_2 := Find_Designated_Type (Type_2); - -- The context is an instance association for a formal + -- If the context is an instance association for a formal -- access-to-subprogram type; formal access parameter designated -- types require mapping because they may denote other formal -- parameters of the generic unit. @@ -3268,10 +4748,23 @@ package body Sem_Ch6 is Etype (Base_Type (Desig_2)), Ctype); elsif Are_Anonymous_Access_To_Subprogram_Types then - return Ctype = Type_Conformant - or else + if Ada_Version < Ada_05 then + return Ctype = Type_Conformant + or else Subtypes_Statically_Match (Desig_1, Desig_2); + -- We must check the conformance of the signatures themselves + + else + declare + Conformant : Boolean; + begin + Check_Conformance + (Desig_1, Desig_2, Ctype, False, Conformant); + return Conformant; + end; + end if; + else return Base_Type (Desig_1) = Base_Type (Desig_2) and then (Ctype = Type_Conformant @@ -3283,9 +4776,19 @@ package body Sem_Ch6 is -- Otherwise definitely no match else + if ((Ekind (Type_1) = E_Anonymous_Access_Type + and then Is_Access_Type (Type_2)) + or else (Ekind (Type_2) = E_Anonymous_Access_Type + and then Is_Access_Type (Type_1))) + and then + Conforming_Types + (Designated_Type (Type_1), Designated_Type (Type_2), Ctype) + then + May_Hide_Profile := True; + end if; + return False; end if; - end Conforming_Types; -------------------------- @@ -3294,32 +4797,38 @@ package body Sem_Ch6 is procedure Create_Extra_Formals (E : Entity_Id) is Formal : Entity_Id; + First_Extra : Entity_Id := Empty; Last_Extra : Entity_Id; Formal_Type : Entity_Id; P_Formal : Entity_Id := Empty; - function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id; - -- Add an extra formal, associated with the current Formal. The extra - -- formal is added to the list of extra formals, and also returned as - -- the result. These formals are always of mode IN. + function Add_Extra_Formal + (Assoc_Entity : Entity_Id; + Typ : Entity_Id; + Scope : Entity_Id; + Suffix : String) return Entity_Id; + -- Add an extra formal to the current list of formals and extra formals. + -- The extra formal is added to the end of the list of extra formals, + -- and also returned as the result. These formals are always of mode IN. + -- The new formal has the type Typ, is declared in Scope, and its name + -- is given by a concatenation of the name of Assoc_Entity and Suffix. ---------------------- -- Add_Extra_Formal -- ---------------------- - function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id is + function Add_Extra_Formal + (Assoc_Entity : Entity_Id; + Typ : Entity_Id; + Scope : Entity_Id; + Suffix : String) return Entity_Id + is EF : constant Entity_Id := - Make_Defining_Identifier (Sloc (Formal), - Chars => New_External_Name (Chars (Formal), 'F')); + Make_Defining_Identifier (Sloc (Assoc_Entity), + Chars => New_External_Name (Chars (Assoc_Entity), + Suffix => Suffix)); begin - -- We never generate extra formals if expansion is not active - -- because we don't need them unless we are generating code. - - if not Expander_Active then - return Empty; - end if; - -- A little optimization. Never generate an extra formal for the -- _init operand of an initialization procedure, since it could -- never be used. @@ -3331,18 +4840,34 @@ package body Sem_Ch6 is Set_Ekind (EF, E_In_Parameter); Set_Actual_Subtype (EF, Typ); Set_Etype (EF, Typ); - Set_Scope (EF, Scope (Formal)); + Set_Scope (EF, Scope); Set_Mechanism (EF, Default_Mechanism); Set_Formal_Validity (EF); - Set_Extra_Formal (Last_Extra, EF); + if No (First_Extra) then + First_Extra := EF; + Set_Extra_Formals (Scope, First_Extra); + end if; + + if Present (Last_Extra) then + Set_Extra_Formal (Last_Extra, EF); + end if; + Last_Extra := EF; + return EF; end Add_Extra_Formal; -- Start of processing for Create_Extra_Formals begin + -- We never generate extra formals if expansion is not active + -- because we don't need them unless we are generating code. + + if not Expander_Active then + return; + end if; + -- If this is a derived subprogram then the subtypes of the parent -- subprogram's formal parameters will be used to to determine the need -- for extra formals. @@ -3358,7 +4883,7 @@ package body Sem_Ch6 is Next_Formal (Formal); end loop; - -- If Extra_formals where already created, don't do it again. This + -- If Extra_formals were already created, don't do it again. This -- situation may arise for subprogram types created as part of -- dispatching calls (see Expand_Dispatching_Call) @@ -3368,8 +4893,18 @@ package body Sem_Ch6 is return; end if; - Formal := First_Formal (E); + -- If the subprogram is a predefined dispatching subprogram then don't + -- generate any extra constrained or accessibility level formals. In + -- general we suppress these for internal subprograms (by not calling + -- Freeze_Subprogram and Create_Extra_Formals at all), but internally + -- generated stream attributes do get passed through because extra + -- build-in-place formals are needed in some cases (limited 'Input). + if Is_Predefined_Dispatching_Operation (E) then + goto Test_For_BIP_Extras; + end if; + + Formal := First_Formal (E); while Present (Formal) loop -- Create extra formal for supporting the attribute 'Constrained. @@ -3399,33 +4934,40 @@ package body Sem_Ch6 is end if; if Has_Discriminants (Formal_Type) - and then - ((not Is_Constrained (Formal_Type) - and then not Is_Indefinite_Subtype (Formal_Type)) - or else Present (Extra_Formal (Formal))) + and then not Is_Constrained (Formal_Type) + and then not Is_Indefinite_Subtype (Formal_Type) then Set_Extra_Constrained - (Formal, Add_Extra_Formal (Standard_Boolean)); + (Formal, Add_Extra_Formal (Formal, Standard_Boolean, E, "F")); end if; end if; - -- Create extra formal for supporting accessibility checking + -- Create extra formal for supporting accessibility checking. This + -- is done for both anonymous access formals and formals of named + -- access types that are marked as controlling formals. The latter + -- case can occur when Expand_Dispatching_Call creates a subprogram + -- type and substitutes the types of access-to-class-wide actuals + -- for the anonymous access-to-specific-type of controlling formals. + -- Base_Type is applied because in cases where there is a null + -- exclusion the formal may have an access subtype. -- This is suppressed if we specifically suppress accessibility - -- checks at the pacage level for either the subprogram, or the + -- checks at the package level for either the subprogram, or the -- package in which it resides. However, we do not suppress it -- simply if the scope has accessibility checks suppressed, since -- this could cause trouble when clients are compiled with a -- different suppression setting. The explicit checks at the -- package level are safe from this point of view. - if Ekind (Etype (Formal)) = E_Anonymous_Access_Type + if (Ekind (Base_Type (Etype (Formal))) = E_Anonymous_Access_Type + or else (Is_Controlling_Formal (Formal) + and then Is_Access_Type (Base_Type (Etype (Formal))))) and then not (Explicit_Suppress (E, Accessibility_Check) or else Explicit_Suppress (Scope (E), Accessibility_Check)) and then - (not Present (P_Formal) + (No (P_Formal) or else Present (Extra_Accessibility (P_Formal))) then -- Temporary kludge: for now we avoid creating the extra formal @@ -3436,21 +4978,125 @@ package body Sem_Ch6 is and then Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Body then Set_Extra_Accessibility - (Formal, Add_Extra_Formal (Standard_Natural)); + (Formal, Add_Extra_Formal (Formal, Standard_Natural, E, "F")); end if; end if; - if Present (P_Formal) then - Next_Formal (P_Formal); - end if; - -- This label is required when skipping extra formal generation for -- Unchecked_Union parameters. <> + if Present (P_Formal) then + Next_Formal (P_Formal); + end if; + Next_Formal (Formal); end loop; + + <> + + -- Ada 2005 (AI-318-02): In the case of build-in-place functions, add + -- appropriate extra formals. See type Exp_Ch6.BIP_Formal_Kind. + + if Ada_Version >= Ada_05 and then Is_Build_In_Place_Function (E) then + declare + Result_Subt : constant Entity_Id := Etype (E); + + Discard : Entity_Id; + pragma Warnings (Off, Discard); + + begin + -- In the case of functions with unconstrained result subtypes, + -- add a 3-state formal indicating whether the return object is + -- allocated by the caller (0), or should be allocated by the + -- callee on the secondary stack (1) or in the global heap (2). + -- For the moment we just use Natural for the type of this formal. + -- Note that this formal isn't usually needed in the case where + -- the result subtype is constrained, but it is needed when the + -- function has a tagged result, because generally such functions + -- can be called in a dispatching context and such calls must be + -- handled like calls to a class-wide function. + + if not Is_Constrained (Result_Subt) + or else Is_Tagged_Type (Underlying_Type (Result_Subt)) + then + Discard := + Add_Extra_Formal + (E, Standard_Natural, + E, BIP_Formal_Suffix (BIP_Alloc_Form)); + end if; + + -- In the case of functions whose result type has controlled + -- parts, we have an extra formal of type + -- System.Finalization_Implementation.Finalizable_Ptr_Ptr. That + -- is, we are passing a pointer to a finalization list (which is + -- itself a pointer). This extra formal is then passed along to + -- Move_Final_List in case of successful completion of a return + -- statement. We cannot pass an 'in out' parameter, because we + -- need to update the finalization list during an abort-deferred + -- region, rather than using copy-back after the function + -- returns. This is true even if we are able to get away with + -- having 'in out' parameters, which are normally illegal for + -- functions. This formal is also needed when the function has + -- a tagged result, because generally such functions can be called + -- in a dispatching context and such calls must be handled like + -- calls to class-wide functions. + + if Controlled_Type (Result_Subt) + or else Is_Tagged_Type (Underlying_Type (Result_Subt)) + then + Discard := + Add_Extra_Formal + (E, RTE (RE_Finalizable_Ptr_Ptr), + E, BIP_Formal_Suffix (BIP_Final_List)); + end if; + + -- If the result type contains tasks, we have two extra formals: + -- the master of the tasks to be created, and the caller's + -- activation chain. + + if Has_Task (Result_Subt) then + Discard := + Add_Extra_Formal + (E, RTE (RE_Master_Id), + E, BIP_Formal_Suffix (BIP_Master)); + Discard := + Add_Extra_Formal + (E, RTE (RE_Activation_Chain_Access), + E, BIP_Formal_Suffix (BIP_Activation_Chain)); + end if; + + -- All build-in-place functions get an extra formal that will be + -- passed the address of the return object within the caller. + + declare + Formal_Type : constant Entity_Id := + Create_Itype + (E_Anonymous_Access_Type, E, + Scope_Id => Scope (E)); + begin + Set_Directly_Designated_Type (Formal_Type, Result_Subt); + Set_Etype (Formal_Type, Formal_Type); + Set_Depends_On_Private + (Formal_Type, Has_Private_Component (Formal_Type)); + Set_Is_Public (Formal_Type, Is_Public (Scope (Formal_Type))); + Set_Is_Access_Constant (Formal_Type, False); + + -- Ada 2005 (AI-50217): Propagate the attribute that indicates + -- the designated type comes from the limited view (for + -- back-end purposes). + + Set_From_With_Type (Formal_Type, From_With_Type (Result_Subt)); + + Layout_Type (Formal_Type); + + Discard := + Add_Extra_Formal + (E, Formal_Type, E, BIP_Formal_Suffix (BIP_Object_Access)); + end; + end; + end if; end Create_Extra_Formals; ----------------------------- @@ -3518,8 +5164,10 @@ package body Sem_Ch6 is -- Warn unless genuine overloading - if (not Is_Overloadable (E)) - or else Subtype_Conformant (E, S) + if (not Is_Overloadable (E) or else Subtype_Conformant (E, S)) + and then (Is_Immediately_Visible (E) + or else + Is_Potentially_Use_Visible (S)) then Error_Msg_Sloc := Sloc (E); Error_Msg_N ("declaration of & hides one#?", S); @@ -3540,7 +5188,6 @@ package body Sem_Ch6 is begin E := Current_Entity (Designator); - while Present (E) loop -- We are looking for a matching spec. It must have the same scope, @@ -3592,6 +5239,36 @@ package body Sem_Ch6 is return E; + -- If E is an internal function with a controlling result + -- that was created for an operation inherited by a null + -- extension, it may be overridden by a body without a previous + -- spec (one more reason why these should be shunned). In that + -- case remove the generated body, because the current one is + -- the explicit overriding. + + elsif Ekind (E) = E_Function + and then Ada_Version >= Ada_05 + and then not Comes_From_Source (E) + and then Has_Controlling_Result (E) + and then Is_Null_Extension (Etype (E)) + and then Comes_From_Source (Spec) + then + Set_Has_Completion (E, False); + + if Expander_Active then + Remove + (Unit_Declaration_Node + (Corresponding_Body (Unit_Declaration_Node (E)))); + return E; + + -- If expansion is disabled, the wrapper function has not + -- been generated, and this is the standard case of a late + -- body overriding an inherited operation. + + else + return Empty; + end if; + -- If body already exists, this is an error unless the -- previous declaration is the implicit declaration of -- a derived subprogram, or this is a spurious overloading @@ -3615,10 +5292,9 @@ package body Sem_Ch6 is and then Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body and then - Nkind (Parent (Unit_Declaration_Node (Designator))) - = N_Compilation_Unit + Nkind (Parent (Unit_Declaration_Node (Designator))) = + N_Compilation_Unit then - -- Child units cannot be overloaded, so a conformance mismatch -- between body and a previous spec is an error. @@ -3642,7 +5318,6 @@ package body Sem_Ch6 is function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is Result : Boolean; - begin Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result); return Result; @@ -3751,7 +5426,7 @@ package body Sem_Ch6 is begin -- Non-conformant if paren count does not match. Note: if some idiot -- complains that we don't do this right for more than 3 levels of - -- parentheses, they will be treated with the respect they deserve :-) + -- parentheses, they will be treated with the respect they deserve! if Paren_Count (E1) /= Paren_Count (E2) then return False; @@ -3883,7 +5558,7 @@ package body Sem_Ch6 is and then FCE (Left_Opnd (E1), Left_Opnd (E2)) and then FCE (Right_Opnd (E1), Right_Opnd (E2)); - when N_And_Then | N_Or_Else | N_In | N_Not_In => + when N_And_Then | N_Or_Else | N_Membership_Test => return FCE (Left_Opnd (E1), Left_Opnd (E2)) and then @@ -4039,6 +5714,10 @@ package body Sem_Ch6 is function Conforming_Ranges (R1, R2 : Node_Id) return Boolean; -- Check both bounds + ----------------------- + -- Conforming_Bounds -- + ----------------------- + function Conforming_Bounds (B1, B2 : Node_Id) return Boolean is begin if Is_Entity_Name (B1) @@ -4052,6 +5731,10 @@ package body Sem_Ch6 is end if; end Conforming_Bounds; + ----------------------- + -- Conforming_Ranges -- + ----------------------- + function Conforming_Ranges (R1, R2 : Node_Id) return Boolean is begin return @@ -4090,7 +5773,6 @@ package body Sem_Ch6 is procedure Install_Entity (E : Entity_Id) is Prev : constant Entity_Id := Current_Entity (E); - begin Set_Is_Immediately_Visible (E); Set_Current_Entity (E); @@ -4103,10 +5785,8 @@ package body Sem_Ch6 is procedure Install_Formals (Id : Entity_Id) is F : Entity_Id; - begin F := First_Formal (Id); - while Present (F) loop Install_Entity (F); Next_Formal (F); @@ -4126,9 +5806,8 @@ package body Sem_Ch6 is G_Typ : Entity_Id := Empty; function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id; - -- If F_Type is a derived type associated with a generic actual - -- subtype, then return its Generic_Parent_Type attribute, else return - -- Empty. + -- If F_Type is a derived type associated with a generic actual subtype, + -- then return its Generic_Parent_Type attribute, else return Empty. function Types_Correspond (P_Type : Entity_Id; @@ -4242,7 +5921,7 @@ package body Sem_Ch6 is Next_Formal (Formal); end loop; - if not Present (G_Typ) and then Ekind (Prev_E) = E_Function then + if No (G_Typ) and then Ekind (Prev_E) = E_Function then G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E))); end if; @@ -4298,8 +5977,8 @@ package body Sem_Ch6 is -- formal ancestor type, so the new subprogram is -- overriding. - if not Present (P_Formal) - and then not Present (N_Formal) + if No (P_Formal) + and then No (N_Formal) and then (Ekind (New_E) /= E_Function or else Types_Correspond @@ -4338,61 +6017,77 @@ package body Sem_Ch6 is Formals : List_Id; Op_Name : Entity_Id; - A : Entity_Id; - B : Entity_Id; + FF : constant Entity_Id := First_Formal (S); + NF : constant Entity_Id := Next_Formal (FF); begin - -- Check that equality was properly defined + -- Check that equality was properly defined, ignore call if not - if No (Next_Formal (First_Formal (S))) then + if No (NF) then return; end if; - A := Make_Defining_Identifier (Loc, Chars (First_Formal (S))); - B := Make_Defining_Identifier (Loc, - Chars (Next_Formal (First_Formal (S)))); - - Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne); - - Formals := New_List ( - Make_Parameter_Specification (Loc, - Defining_Identifier => A, - Parameter_Type => - New_Reference_To (Etype (First_Formal (S)), Loc)), - - Make_Parameter_Specification (Loc, - Defining_Identifier => B, - Parameter_Type => - New_Reference_To (Etype (Next_Formal (First_Formal (S))), Loc))); - - Decl := - Make_Subprogram_Declaration (Loc, - Specification => - Make_Function_Specification (Loc, - Defining_Unit_Name => Op_Name, - Parameter_Specifications => Formals, - Subtype_Mark => New_Reference_To (Standard_Boolean, Loc))); - - -- Insert inequality right after equality if it is explicit or after - -- the derived type when implicit. These entities are created only - -- for visibility purposes, and eventually replaced in the course of - -- expansion, so they do not need to be attached to the tree and seen - -- by the back-end. Keeping them internal also avoids spurious freezing - -- problems. The parent field is set simply to make analysis safe. - - if No (Alias (S)) then - Set_Parent (Decl, Parent (Unit_Declaration_Node (S))); - else - Set_Parent (Decl, Parent (Parent (Etype (First_Formal (S))))); - end if; + declare + A : constant Entity_Id := + Make_Defining_Identifier (Sloc (FF), + Chars => Chars (FF)); + + B : constant Entity_Id := + Make_Defining_Identifier (Sloc (NF), + Chars => Chars (NF)); - Mark_Rewrite_Insertion (Decl); - Set_Is_Intrinsic_Subprogram (Op_Name); - Analyze (Decl); - Set_Has_Completion (Op_Name); - Set_Corresponding_Equality (Op_Name, S); - Set_Is_Abstract (Op_Name, Is_Abstract (S)); + begin + Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne); + + Formals := New_List ( + Make_Parameter_Specification (Loc, + Defining_Identifier => A, + Parameter_Type => + New_Reference_To (Etype (First_Formal (S)), + Sloc (Etype (First_Formal (S))))), + + Make_Parameter_Specification (Loc, + Defining_Identifier => B, + Parameter_Type => + New_Reference_To (Etype (Next_Formal (First_Formal (S))), + Sloc (Etype (Next_Formal (First_Formal (S))))))); + + Decl := + Make_Subprogram_Declaration (Loc, + Specification => + Make_Function_Specification (Loc, + Defining_Unit_Name => Op_Name, + Parameter_Specifications => Formals, + Result_Definition => + New_Reference_To (Standard_Boolean, Loc))); + + -- Insert inequality right after equality if it is explicit or after + -- the derived type when implicit. These entities are created only + -- for visibility purposes, and eventually replaced in the course of + -- expansion, so they do not need to be attached to the tree and seen + -- by the back-end. Keeping them internal also avoids spurious + -- freezing problems. The declaration is inserted in the tree for + -- analysis, and removed afterwards. If the equality operator comes + -- from an explicit declaration, attach the inequality immediately + -- after. Else the equality is inherited from a derived type + -- declaration, so insert inequality after that declaration. + + if No (Alias (S)) then + Insert_After (Unit_Declaration_Node (S), Decl); + elsif Is_List_Member (Parent (S)) then + Insert_After (Parent (S), Decl); + else + Insert_After (Parent (Etype (First_Formal (S))), Decl); + end if; + Mark_Rewrite_Insertion (Decl); + Set_Is_Intrinsic_Subprogram (Op_Name); + Analyze (Decl); + Remove (Decl); + Set_Has_Completion (Op_Name); + Set_Corresponding_Equality (Op_Name, S); + Set_Is_Abstract_Subprogram (Op_Name, Is_Abstract_Subprogram (S)); + end; end Make_Inequality_Operator; ---------------------- @@ -4406,7 +6101,6 @@ package body Sem_Ch6 is begin F := First_Formal (Fun); B := True; - while Present (F) loop if No (Default_Value (F)) then B := False; @@ -4438,56 +6132,52 @@ package body Sem_Ch6 is (S : Entity_Id; Derived_Type : Entity_Id := Empty) is + Overridden_Subp : Entity_Id := Empty; + -- Set if the current scope has an operation that is type-conformant + -- with S, and becomes hidden by S. + + Is_Primitive_Subp : Boolean; + -- Set to True if the new subprogram is primitive + E : Entity_Id; -- Entity that S overrides Prev_Vis : Entity_Id := Empty; - -- Needs comment ??? + -- Predecessor of E in Homonym chain + + procedure Check_For_Primitive_Subprogram + (Is_Primitive : out Boolean; + Is_Overriding : Boolean := False); + -- If the subprogram being analyzed is a primitive operation of the type + -- of a formal or result, set the Has_Primitive_Operations flag on the + -- type, and set Is_Primitive to True (otherwise set to False). Set the + -- corresponding flag on the entity itself for later use. + + procedure Check_Synchronized_Overriding + (Def_Id : Entity_Id; + First_Hom : Entity_Id; + Overridden_Subp : out Entity_Id); + -- First determine if Def_Id is an entry or a subprogram either defined + -- in the scope of a task or protected type, or is a primitive of such + -- a type. Check whether Def_Id overrides a subprogram of an interface + -- implemented by the synchronized type, return the overridden entity + -- or Empty. function Is_Private_Declaration (E : Entity_Id) return Boolean; -- Check that E is declared in the private part of the current package, - -- or in the package body, where it may hide a previous declaration. - -- We can't use In_Private_Part by itself because this flag is also - -- set when freezing entities, so we must examine the place of the - -- declaration in the tree, and recognize wrapper packages as well. - - procedure Maybe_Primitive_Operation (Is_Overriding : Boolean := False); - -- If the subprogram being analyzed is a primitive operation of - -- the type of one of its formals, set the corresponding flag. - - ---------------------------- - -- Is_Private_Declaration -- - ---------------------------- - - function Is_Private_Declaration (E : Entity_Id) return Boolean is - Priv_Decls : List_Id; - Decl : constant Node_Id := Unit_Declaration_Node (E); - - begin - if Is_Package (Current_Scope) - and then In_Private_Part (Current_Scope) - then - Priv_Decls := - Private_Declarations ( - Specification (Unit_Declaration_Node (Current_Scope))); - - return In_Package_Body (Current_Scope) - or else List_Containing (Decl) = Priv_Decls - or else (Nkind (Parent (Decl)) = N_Package_Specification - and then not Is_Compilation_Unit ( - Defining_Entity (Parent (Decl))) - and then List_Containing (Parent (Parent (Decl))) - = Priv_Decls); - else - return False; - end if; - end Is_Private_Declaration; + -- or in the package body, where it may hide a previous declaration. + -- We can't use In_Private_Part by itself because this flag is also + -- set when freezing entities, so we must examine the place of the + -- declaration in the tree, and recognize wrapper packages as well. - ------------------------------- - -- Maybe_Primitive_Operation -- - ------------------------------- + ------------------------------------ + -- Check_For_Primitive_Subprogram -- + ------------------------------------ - procedure Maybe_Primitive_Operation (Is_Overriding : Boolean := False) is + procedure Check_For_Primitive_Subprogram + (Is_Primitive : out Boolean; + Is_Overriding : Boolean := False) + is Formal : Entity_Id; F_Typ : Entity_Id; B_Typ : Entity_Id; @@ -4516,12 +6206,13 @@ package body Sem_Ch6 is and then Visible_Part_Type (T) and then not In_Instance then - if Is_Abstract (T) - and then Is_Abstract (S) - and then (not Is_Overriding or else not Is_Abstract (E)) + if Is_Abstract_Type (T) + and then Is_Abstract_Subprogram (S) + and then (not Is_Overriding + or else not Is_Abstract_Subprogram (E)) then Error_Msg_N ("abstract subprograms must be visible " - & "('R'M 3.9.3(10))!", S); + & "(RM 3.9.3(10))!", S); elsif Ekind (S) = E_Function and then Is_Tagged_Type (T) @@ -4533,7 +6224,7 @@ package body Sem_Ch6 is & " override visible-part function", S); Error_Msg_N ("\move subprogram to the visible part" - & " ('R'M 3.9.3(10))", S); + & " (RM 3.9.3(10))", S); end if; end if; end Check_Private_Overriding; @@ -4568,9 +6259,8 @@ package body Sem_Ch6 is then return True; - elsif (Nkind (N) = N_Private_Type_Declaration - or else - Nkind (N) = N_Private_Extension_Declaration) + elsif Nkind_In (N, N_Private_Type_Declaration, + N_Private_Extension_Declaration) and then Present (Defining_Identifier (N)) and then T = Full_View (Defining_Identifier (N)) then @@ -4583,29 +6273,42 @@ package body Sem_Ch6 is return False; end Visible_Part_Type; - -- Start of processing for Maybe_Primitive_Operation + -- Start of processing for Check_For_Primitive_Subprogram begin + Is_Primitive := False; + if not Comes_From_Source (S) then null; - -- If the subprogram is at library level, it is not primitive - -- operation. + -- If subprogram is at library level, it is not primitive operation elsif Current_Scope = Standard_Standard then null; - elsif (Ekind (Current_Scope) = E_Package + elsif ((Ekind (Current_Scope) = E_Package + or else Ekind (Current_Scope) = E_Generic_Package) and then not In_Package_Body (Current_Scope)) or else Is_Overriding then -- For function, check return type if Ekind (S) = E_Function then - B_Typ := Base_Type (Etype (S)); + if Ekind (Etype (S)) = E_Anonymous_Access_Type then + F_Typ := Designated_Type (Etype (S)); + else + F_Typ := Etype (S); + end if; + + B_Typ := Base_Type (F_Typ); - if Scope (B_Typ) = Current_Scope then + if Scope (B_Typ) = Current_Scope + and then not Is_Class_Wide_Type (B_Typ) + and then not Is_Generic_Type (B_Typ) + then + Is_Primitive := True; Set_Has_Primitive_Operations (B_Typ); + Set_Is_Primitive (S); Check_Private_Overriding (B_Typ); end if; end if; @@ -4622,7 +6325,16 @@ package body Sem_Ch6 is B_Typ := Base_Type (F_Typ); - if Scope (B_Typ) = Current_Scope then + if Ekind (B_Typ) = E_Access_Subtype then + B_Typ := Base_Type (B_Typ); + end if; + + if Scope (B_Typ) = Current_Scope + and then not Is_Class_Wide_Type (B_Typ) + and then not Is_Generic_Type (B_Typ) + then + Is_Primitive := True; + Set_Is_Primitive (S); Set_Has_Primitive_Operations (B_Typ); Check_Private_Overriding (B_Typ); end if; @@ -4630,7 +6342,123 @@ package body Sem_Ch6 is Next_Formal (Formal); end loop; end if; - end Maybe_Primitive_Operation; + end Check_For_Primitive_Subprogram; + + ----------------------------------- + -- Check_Synchronized_Overriding -- + ----------------------------------- + + procedure Check_Synchronized_Overriding + (Def_Id : Entity_Id; + First_Hom : Entity_Id; + Overridden_Subp : out Entity_Id) + is + Formal_Typ : Entity_Id; + Ifaces_List : Elist_Id; + In_Scope : Boolean; + Typ : Entity_Id; + + begin + Overridden_Subp := Empty; + + -- Def_Id must be an entry or a subprogram + + if Ekind (Def_Id) /= E_Entry + and then Ekind (Def_Id) /= E_Function + and then Ekind (Def_Id) /= E_Procedure + then + return; + end if; + + -- Search for the concurrent declaration since it contains the list + -- of all implemented interfaces. In this case, the subprogram is + -- declared within the scope of a protected or a task type. + + if Present (Scope (Def_Id)) + and then Is_Concurrent_Type (Scope (Def_Id)) + and then not Is_Generic_Actual_Type (Scope (Def_Id)) + then + Typ := Scope (Def_Id); + In_Scope := True; + + -- The subprogram may be a primitive of a concurrent type + + elsif Present (First_Formal (Def_Id)) then + Formal_Typ := Etype (First_Formal (Def_Id)); + + if Is_Concurrent_Type (Formal_Typ) + and then not Is_Generic_Actual_Type (Formal_Typ) + then + Typ := Formal_Typ; + In_Scope := False; + + -- This case occurs when the concurrent type is declared within + -- a generic unit. As a result the corresponding record has been + -- built and used as the type of the first formal, we just have + -- to retrieve the corresponding concurrent type. + + elsif Is_Concurrent_Record_Type (Formal_Typ) + and then Present (Corresponding_Concurrent_Type (Formal_Typ)) + then + Typ := Corresponding_Concurrent_Type (Formal_Typ); + In_Scope := False; + + else + return; + end if; + else + return; + end if; + + -- Gather all limited, protected and task interfaces that Typ + -- implements. There is no overriding to check if is an inherited + -- operation in a type derivation on for a generic actual. + + if Nkind (Parent (Typ)) /= N_Full_Type_Declaration + and then + not Nkind_In (Parent (Def_Id), N_Subtype_Declaration, + N_Task_Type_Declaration, + N_Protected_Type_Declaration) + then + Collect_Abstract_Interfaces (Typ, Ifaces_List); + + if not Is_Empty_Elmt_List (Ifaces_List) then + Overridden_Subp := + Find_Overridden_Synchronized_Primitive + (Def_Id, First_Hom, Ifaces_List, In_Scope); + end if; + end if; + end Check_Synchronized_Overriding; + + ---------------------------- + -- Is_Private_Declaration -- + ---------------------------- + + function Is_Private_Declaration (E : Entity_Id) return Boolean is + Priv_Decls : List_Id; + Decl : constant Node_Id := Unit_Declaration_Node (E); + + begin + if Is_Package_Or_Generic_Package (Current_Scope) + and then In_Private_Part (Current_Scope) + then + Priv_Decls := + Private_Declarations ( + Specification (Unit_Declaration_Node (Current_Scope))); + + return In_Package_Body (Current_Scope) + or else + (Is_List_Member (Decl) + and then List_Containing (Decl) = Priv_Decls) + or else (Nkind (Parent (Decl)) = N_Package_Specification + and then not Is_Compilation_Unit ( + Defining_Entity (Parent (Decl))) + and then List_Containing (Parent (Parent (Decl))) + = Priv_Decls); + else + return False; + end if; + end Is_Private_Declaration; -- Start of processing for New_Overloaded_Entity @@ -4646,7 +6474,16 @@ package body Sem_Ch6 is if No (E) then Enter_Overloaded_Entity (S); Check_Dispatching_Operation (S, Empty); - Maybe_Primitive_Operation; + Check_For_Primitive_Subprogram (Is_Primitive_Subp); + + -- If subprogram has an explicit declaration, check whether it + -- has an overriding indicator. + + if Comes_From_Source (S) then + Check_Synchronized_Overriding (S, Homonym (S), Overridden_Subp); + Check_Overriding_Indicator + (S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp); + end if; -- If there is a homonym that is not overloadable, then we have an -- error, except for the special cases checked explicitly below. @@ -4671,6 +6508,7 @@ package body Sem_Ch6 is Enter_Overloaded_Entity (S); Set_Homonym (S, Homonym (E)); Check_Dispatching_Operation (S, Empty); + Check_Overriding_Indicator (S, Empty, Is_Primitive => False); -- If the subprogram is implicit it is hidden by the previous -- declaration. However if it is dispatching, it must appear in the @@ -4690,12 +6528,14 @@ package body Sem_Ch6 is else Error_Msg_Sloc := Sloc (E); - Error_Msg_N ("& conflicts with declaration#", S); - -- Useful additional warning + -- Generate message,with useful additionalwarning if in generic if Is_Generic_Unit (E) then - Error_Msg_N ("\previous generic unit cannot be overloaded", S); + Error_Msg_N ("previous generic unit cannot be overloaded", S); + Error_Msg_N ("\& conflicts with declaration#", S); + else + Error_Msg_N ("& conflicts with declaration#", S); end if; return; @@ -4704,6 +6544,22 @@ package body Sem_Ch6 is -- E exists and is overloadable else + -- Ada 2005 (AI-251): Derivation of abstract interface primitives + -- need no check against the homonym chain. They are directly added + -- to the list of primitive operations of Derived_Type. + + if Ada_Version >= Ada_05 + and then Present (Derived_Type) + and then Is_Dispatching_Operation (Alias (S)) + and then Present (Find_Dispatching_Type (Alias (S))) + and then Is_Interface (Find_Dispatching_Type (Alias (S))) + and then not Is_Predefined_Dispatching_Operation (Alias (S)) + then + goto Add_New_Entity; + end if; + + Check_Synchronized_Overriding (S, E, Overridden_Subp); + -- Loop through E and its homonyms to determine if any of them is -- the candidate for overriding by S. @@ -4725,7 +6581,7 @@ package body Sem_Ch6 is -- There are some cases when both can be implicit, for example -- when both a literal and a function that overrides it are -- inherited in a derivation, or when an inhertited operation - -- of a tagged full type overrides the ineherited operation of + -- of a tagged full type overrides the inherited operation of -- a private extension. Ada 83 had a special rule for the the -- literal case. In Ada95, the later implicit operation hides -- the former, and the literal is always the former. In the @@ -4750,7 +6606,7 @@ package body Sem_Ch6 is -- the fact that the full view of a private extension -- re-inherits. It has to be dealt with. - if Is_Package (Current_Scope) + if Is_Package_Or_Generic_Package (Current_Scope) and then In_Private_Part (Current_Scope) then Check_Operation_From_Private_View (S, E); @@ -4760,6 +6616,20 @@ package body Sem_Ch6 is -- the existing declaration, which is overriding. Set_Is_Overriding_Operation (E); + + if Comes_From_Source (E) then + Check_Overriding_Indicator (E, S, Is_Primitive => False); + + -- Indicate that E overrides the operation from which + -- S is inherited. + + if Present (Alias (S)) then + Set_Overridden_Operation (E, Alias (S)); + else + Set_Overridden_Operation (E, S); + end if; + end if; + return; -- Within an instance, the renaming declarations for @@ -4788,7 +6658,7 @@ package body Sem_Ch6 is if Is_Non_Overriding_Operation (E, S) then Enter_Overloaded_Entity (S); - if not Present (Derived_Type) + if No (Derived_Type) or else Is_Tagged_Type (Derived_Type) then Check_Dispatching_Operation (S, Empty); @@ -4803,6 +6673,8 @@ package body Sem_Ch6 is -- replaced in the list of primitive operations of its type -- (see Override_Dispatching_Operation). + Overridden_Subp := E; + declare Prev : Entity_Id; @@ -4858,7 +6730,7 @@ package body Sem_Ch6 is -- If the private operation is dispatching, we achieve -- the overriding by keeping the implicit operation - -- but setting its alias to be the overring one. In + -- but setting its alias to be the overriding one. In -- this fashion the proper body is executed in all -- cases, but the original signature is used outside -- of the package. @@ -4910,6 +6782,18 @@ package body Sem_Ch6 is Enter_Overloaded_Entity (S); Set_Is_Overriding_Operation (S); + Check_Overriding_Indicator (S, E, Is_Primitive => True); + + -- Indicate that S overrides the operation from which + -- E is inherited. + + if Comes_From_Source (S) then + if Present (Alias (E)) then + Set_Overridden_Operation (S, Alias (E)); + else + Set_Overridden_Operation (S, E); + end if; + end if; if Is_Dispatching_Operation (E) then @@ -4918,13 +6802,14 @@ package body Sem_Ch6 is -- AI-117). Set_Convention (S, Convention (E)); - Check_Dispatching_Operation (S, E); + else Check_Dispatching_Operation (S, Empty); end if; - Maybe_Primitive_Operation (Is_Overriding => True); + Check_For_Primitive_Subprogram + (Is_Primitive_Subp, Is_Overriding => True); goto Check_Inequality; end; @@ -4952,37 +6837,85 @@ package body Sem_Ch6 is Set_Scope (S, Current_Scope); - Error_Msg_N ("& conflicts with declaration#", S); + -- Generate error, with extra useful warning for the case + -- of a generic instance with no completion. if Is_Generic_Instance (S) and then not Has_Completion (E) then Error_Msg_N - ("\instantiation cannot provide body for it", S); + ("instantiation cannot provide body for&", S); + Error_Msg_N ("\& conflicts with declaration#", S); + else + Error_Msg_N ("& conflicts with declaration#", S); end if; return; end if; else - null; + -- If one subprogram has an access parameter and the other + -- a parameter of an access type, calls to either might be + -- ambiguous. Verify that parameters match except for the + -- access parameter. + + if May_Hide_Profile then + declare + F1 : Entity_Id; + F2 : Entity_Id; + begin + F1 := First_Formal (S); + F2 := First_Formal (E); + while Present (F1) and then Present (F2) loop + if Is_Access_Type (Etype (F1)) then + if not Is_Access_Type (Etype (F2)) + or else not Conforming_Types + (Designated_Type (Etype (F1)), + Designated_Type (Etype (F2)), + Type_Conformant) + then + May_Hide_Profile := False; + end if; + + elsif + not Conforming_Types + (Etype (F1), Etype (F2), Type_Conformant) + then + May_Hide_Profile := False; + end if; + + Next_Formal (F1); + Next_Formal (F2); + end loop; + + if May_Hide_Profile + and then No (F1) + and then No (F2) + then + Error_Msg_NE ("calls to& may be ambiguous?", S, S); + end if; + end; + end if; end if; - Prev_Vis := E; E := Homonym (E); end loop; + <> + -- On exit, we know that S is a new entity Enter_Overloaded_Entity (S); - Maybe_Primitive_Operation; + Check_For_Primitive_Subprogram (Is_Primitive_Subp); + Check_Overriding_Indicator + (S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp); -- If S is a derived operation for an untagged type then by -- definition it's not a dispatching operation (even if the parent -- operation was dispatching), so we don't call -- Check_Dispatching_Operation in that case. - if not Present (Derived_Type) + if No (Derived_Type) or else Is_Tagged_Type (Derived_Type) then Check_Dispatching_Operation (S, Empty); @@ -5018,6 +6951,10 @@ package body Sem_Ch6 is Default : Node_Id; Ptype : Entity_Id; + Num_Out_Params : Nat := 0; + First_Out_Param : Entity_Id := Empty; + -- Used for setting Is_Only_Out_Parameter + function Is_Class_Wide_Default (D : Node_Id) return Boolean; -- Check whether the default has a class-wide type. After analysis the -- default has the type of the formal, so we must also check explicitly @@ -5043,10 +6980,9 @@ package body Sem_Ch6 is -- analyzed. The Ekind is established in a separate loop at the end. Param_Spec := First (T); - while Present (Param_Spec) loop - Formal := Defining_Identifier (Param_Spec); + Set_Never_Set_In_Source (Formal, True); Enter_Name (Formal); -- Case of ordinary parameters @@ -5061,23 +6997,33 @@ package body Sem_Ch6 is Formal_Type := Entity (Ptype); - if Ekind (Formal_Type) = E_Incomplete_Type - or else (Is_Class_Wide_Type (Formal_Type) - and then Ekind (Root_Type (Formal_Type)) = - E_Incomplete_Type) + if Is_Incomplete_Type (Formal_Type) + or else + (Is_Class_Wide_Type (Formal_Type) + and then Is_Incomplete_Type (Root_Type (Formal_Type))) then - -- Ada 2005 (AI-50217): Incomplete tagged types that are made - -- visible by a limited with_clause are valid formal types. + -- Ada 2005 (AI-326): Tagged incomplete types allowed - if From_With_Type (Formal_Type) - and then Is_Tagged_Type (Formal_Type) - then + if Is_Tagged_Type (Formal_Type) then null; - elsif Nkind (Parent (T)) /= N_Access_Function_Definition - and then Nkind (Parent (T)) /= N_Access_Procedure_Definition + -- Special handling of Value_Type for CIL case + + elsif Is_Value_Type (Formal_Type) then + null; + + elsif not Nkind_In (Parent (T), N_Access_Function_Definition, + N_Access_Procedure_Definition) then Error_Msg_N ("invalid use of incomplete type", Param_Spec); + + -- An incomplete type that is not tagged is allowed in an + -- access-to-subprogram type only if it is a local declaration + -- with a forthcoming completion (3.10.1 (9.2/2)). + + elsif Scope (Formal_Type) /= Scope (Current_Scope) then + Error_Msg_N + ("invalid use of limited view of type", Param_Spec); end if; elsif Ekind (Formal_Type) = E_Void then @@ -5087,71 +7033,44 @@ package body Sem_Ch6 is -- Ada 2005 (AI-231): Create and decorate an internal subtype -- declaration corresponding to the null-excluding type of the - -- formal in the enclosing scope. In addition, replace the - -- parameter type of the formal to this internal subtype. - - if Null_Exclusion_Present (Param_Spec) then - declare - Loc : constant Source_Ptr := Sloc (Param_Spec); + -- formal in the enclosing scope. Finally, replace the parameter + -- type of the formal with the internal subtype. - Anon : constant Entity_Id := - Make_Defining_Identifier (Loc, - Chars => New_Internal_Name ('S')); - - Curr_Scope : constant Scope_Stack_Entry := - Scope_Stack.Table (Scope_Stack.Last); - - Ptype : constant Node_Id := Parameter_Type (Param_Spec); - Decl : Node_Id; - P : Node_Id := Parent (Parent (Related_Nod)); - - begin - Set_Is_Internal (Anon); - - Decl := - Make_Subtype_Declaration (Loc, - Defining_Identifier => Anon, - Null_Exclusion_Present => True, - Subtype_Indication => - New_Occurrence_Of (Etype (Ptype), Loc)); - - -- Propagate the null-excluding attribute to the new entity + if Ada_Version >= Ada_05 + and then Null_Exclusion_Present (Param_Spec) + then + if not Is_Access_Type (Formal_Type) then + Error_Msg_N + ("`NOT NULL` allowed only for an access type", Param_Spec); - if Null_Exclusion_Present (Param_Spec) then - Set_Null_Exclusion_Present (Param_Spec, False); - Set_Can_Never_Be_Null (Anon); + else + if Can_Never_Be_Null (Formal_Type) + and then Comes_From_Source (Related_Nod) + then + Error_Msg_NE + ("`NOT NULL` not allowed (& already excludes null)", + Param_Spec, + Formal_Type); end if; - Mark_Rewrite_Insertion (Decl); - - -- Insert the new declaration in the nearest enclosing scope - - while not Has_Declarations (P) loop - P := Parent (P); - end loop; - - Prepend (Decl, Declarations (P)); - - Rewrite (Ptype, New_Occurrence_Of (Anon, Loc)); - Mark_Rewrite_Insertion (Ptype); - - -- Analyze the new declaration in the context of the - -- enclosing scope - - Scope_Stack.Decrement_Last; - Analyze (Decl); - Scope_Stack.Append (Curr_Scope); + Formal_Type := + Create_Null_Excluding_Itype + (T => Formal_Type, + Related_Nod => Related_Nod, + Scope_Id => Scope (Current_Scope)); - Formal_Type := Anon; - end; - end if; + -- If the designated type of the itype is an itype we + -- decorate it with the Has_Delayed_Freeze attribute to + -- avoid problems with the backend. - -- Ada 2005 (AI-231): Static checks + -- Example: + -- type T is access procedure; + -- procedure Op (O : not null T); - if Null_Exclusion_Present (Param_Spec) - or else Can_Never_Be_Null (Entity (Ptype)) - then - Null_Exclusion_Static_Checks (Param_Spec); + if Is_Itype (Directly_Designated_Type (Formal_Type)) then + Set_Has_Delayed_Freeze (Formal_Type); + end if; + end if; end if; -- An access formal type @@ -5160,6 +7079,12 @@ package body Sem_Ch6 is Formal_Type := Access_Definition (Related_Nod, Parameter_Type (Param_Spec)); + -- No need to continue if we already notified errors + + if not Present (Formal_Type) then + return; + end if; + -- Ada 2005 (AI-254) declare @@ -5170,7 +7095,7 @@ package body Sem_Ch6 is if Present (AD) and then Protected_Present (AD) then Formal_Type := Replace_Anonymous_Access_To_Protected_Subprogram - (Param_Spec, Formal_Type); + (Param_Spec); end if; end; end if; @@ -5188,13 +7113,27 @@ package body Sem_Ch6 is -- Do the special preanalysis of the expression (see section on -- "Handling of Default Expressions" in the spec of package Sem). - Analyze_Per_Use_Expression (Default, Formal_Type); + Preanalyze_Spec_Expression (Default, Formal_Type); + + -- An access to constant cannot be the default for + -- an access parameter that is an access to variable. + + if Ekind (Formal_Type) = E_Anonymous_Access_Type + and then not Is_Access_Constant (Formal_Type) + and then Is_Access_Type (Etype (Default)) + and then Is_Access_Constant (Etype (Default)) + then + Error_Msg_N + ("formal that is access to variable cannot be initialized " & + "with an access-to-constant expression", Default); + end if; - -- Check that the designated type of an access parameter's - -- default is not a class-wide type unless the parameter's - -- designated type is also class-wide. + -- Check that the designated type of an access parameter's default + -- is not a class-wide type unless the parameter's designated type + -- is also class-wide. if Ekind (Formal_Type) = E_Anonymous_Access_Type + and then not From_With_Type (Formal_Type) and then Is_Class_Wide_Default (Default) and then not Is_Class_Wide_Type (Designated_Type (Formal_Type)) then @@ -5203,6 +7142,15 @@ package body Sem_Ch6 is end if; end if; + -- Ada 2005 (AI-231): Static checks + + if Ada_Version >= Ada_05 + and then Is_Access_Type (Etype (Formal)) + and then Can_Never_Be_Null (Etype (Formal)) + then + Null_Exclusion_Static_Checks (Param_Spec); + end if; + <> Next (Param_Spec); end loop; @@ -5243,13 +7191,213 @@ package body Sem_Ch6 is Apply_Scalar_Range_Check (Default, Formal_Type); end if; end if; + + elsif Ekind (Formal) = E_Out_Parameter then + Num_Out_Params := Num_Out_Params + 1; + + if Num_Out_Params = 1 then + First_Out_Param := Formal; + end if; + + elsif Ekind (Formal) = E_In_Out_Parameter then + Num_Out_Params := Num_Out_Params + 1; end if; Next (Param_Spec); end loop; + if Present (First_Out_Param) and then Num_Out_Params = 1 then + Set_Is_Only_Out_Parameter (First_Out_Param); + end if; end Process_Formals; + ------------------ + -- Process_PPCs -- + ------------------ + + procedure Process_PPCs + (N : Node_Id; + Spec_Id : Entity_Id; + Body_Id : Entity_Id) + is + Loc : constant Source_Ptr := Sloc (N); + Prag : Node_Id; + Plist : List_Id := No_List; + Subp : Entity_Id; + Parms : List_Id; + + function Grab_PPC (Nam : Name_Id) return Node_Id; + -- Prag contains an analyzed precondition or postcondition pragma. + -- This function copies the pragma, changes it to the corresponding + -- Check pragma and returns the Check pragma as the result. The + -- argument Nam is either Name_Precondition or Name_Postcondition. + + -------------- + -- Grab_PPC -- + -------------- + + function Grab_PPC (Nam : Name_Id) return Node_Id is + CP : constant Node_Id := New_Copy_Tree (Prag); + + begin + -- Set Analyzed to false, since we want to reanalyze the check + -- procedure. Note that it is only at the outer level that we + -- do this fiddling, for the spec cases, the already preanalyzed + -- parameters are not affected. + + Set_Analyzed (CP, False); + + -- Change pragma into corresponding pragma Check + + Prepend_To (Pragma_Argument_Associations (CP), + Make_Pragma_Argument_Association (Sloc (Prag), + Expression => + Make_Identifier (Loc, + Chars => Nam))); + Set_Pragma_Identifier (CP, + Make_Identifier (Sloc (Prag), + Chars => Name_Check)); + + return CP; + end Grab_PPC; + + -- Start of processing for Process_PPCs + + begin + -- Grab preconditions from spec + + if Present (Spec_Id) then + + -- Loop through PPC pragmas from spec. Note that preconditions from + -- the body will be analyzed and converted when we scan the body + -- declarations below. + + Prag := Spec_PPC_List (Spec_Id); + while Present (Prag) loop + if Pragma_Name (Prag) = Name_Precondition + and then PPC_Enabled (Prag) + then + -- Add pragma Check at the start of the declarations of N. + -- Note that this processing reverses the order of the list, + -- which is what we want since new entries were chained to + -- the head of the list. + + Prepend (Grab_PPC (Name_Precondition), Declarations (N)); + end if; + + Prag := Next_Pragma (Prag); + end loop; + end if; + + -- Build postconditions procedure if needed and prepend the following + -- declaration to the start of the declarations for the subprogram. + + -- procedure _postconditions [(_Result : resulttype)] is + -- begin + -- pragma Check (Postcondition, condition [,message]); + -- pragma Check (Postcondition, condition [,message]); + -- ... + -- end; + + -- First we deal with the postconditions in the body + + if Is_Non_Empty_List (Declarations (N)) then + + -- Loop through declarations + + Prag := First (Declarations (N)); + while Present (Prag) loop + if Nkind (Prag) = N_Pragma then + + -- If pragma, capture if enabled postcondition, else ignore + + if Pragma_Name (Prag) = Name_Postcondition + and then Check_Enabled (Name_Postcondition) + then + if Plist = No_List then + Plist := Empty_List; + end if; + + Analyze (Prag); + Append (Grab_PPC (Name_Postcondition), Plist); + end if; + + Next (Prag); + + -- Not a pragma, if comes from source, then end scan + + elsif Comes_From_Source (Prag) then + exit; + + -- Skip stuff not coming from source + + else + Next (Prag); + end if; + end loop; + end if; + + -- Now deal with any postconditions from the spec + + if Present (Spec_Id) then + + -- Loop through PPC pragmas from spec + + Prag := Spec_PPC_List (Spec_Id); + while Present (Prag) loop + if Pragma_Name (Prag) = Name_Postcondition + and then PPC_Enabled (Prag) + then + if Plist = No_List then + Plist := Empty_List; + end if; + + Append (Grab_PPC (Name_Postcondition), Plist); + end if; + + Prag := Next_Pragma (Prag); + end loop; + end if; + + -- If we had any postconditions, build the procedure + + if Present (Plist) then + Subp := Defining_Entity (N); + + if Etype (Subp) /= Standard_Void_Type then + Parms := New_List ( + Make_Parameter_Specification (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, + Chars => Name_uResult), + Parameter_Type => New_Occurrence_Of (Etype (Subp), Loc))); + else + Parms := No_List; + end if; + + Prepend_To (Declarations (N), + Make_Subprogram_Body (Loc, + Specification => + Make_Procedure_Specification (Loc, + Defining_Unit_Name => + Make_Defining_Identifier (Loc, + Chars => Name_uPostconditions), + Parameter_Specifications => Parms), + + Declarations => Empty_List, + + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => Plist))); + + if Present (Spec_Id) then + Set_Has_Postconditions (Spec_Id); + else + Set_Has_Postconditions (Body_Id); + end if; + end if; + end Process_PPCs; + ---------------------------- -- Reference_Body_Formals -- ---------------------------- @@ -5263,10 +7411,12 @@ package body Sem_Ch6 is return; end if; + -- Iterate over both lists. They may be of different lengths if the two + -- specs are not conformant. + Fs := First_Formal (Spec); Fb := First_Formal (Bod); - - while Present (Fs) loop + while Present (Fs) and then Present (Fb) loop Generate_Reference (Fs, Fb, 'b'); if Style_Check then @@ -5325,18 +7475,19 @@ package body Sem_Ch6 is elsif Is_Array_Type (T) then AS_Needed := True; - -- The only other case which needs an actual subtype is an - -- unconstrained record type which is an IN parameter (we cannot - -- generate actual subtypes for the OUT or IN OUT case, since an - -- assignment can change the discriminant values. However we exclude - -- the case of initialization procedures, since discriminants are - -- handled very specially in this context, see the section entitled - -- "Handling of Discriminants" in Einfo. We also exclude the case of - -- Discrim_SO_Functions (functions used in front end layout mode for - -- size/offset values), since in such functions only discriminants - -- are referenced, and not only are such subtypes not needed, but - -- they cannot always be generated, because of order of elaboration - -- issues. + -- The only other case needing an actual subtype is an unconstrained + -- record type which is an IN parameter (we cannot generate actual + -- subtypes for the OUT or IN OUT case, since an assignment can + -- change the discriminant values. However we exclude the case of + -- initialization procedures, since discriminants are handled very + -- specially in this context, see the section entitled "Handling of + -- Discriminants" in Einfo. + + -- We also exclude the case of Discrim_SO_Functions (functions used + -- in front end layout mode for size/offset values), since in such + -- functions only discriminants are referenced, and not only are such + -- subtypes not needed, but they cannot always be generated, because + -- of order of elaboration issues. elsif Is_Record_Type (T) and then Ekind (Formal) = E_In_Parameter @@ -5454,15 +7605,22 @@ package body Sem_Ch6 is if Nkind (Parameter_Type (Spec)) = N_Access_Definition then - -- Ada 2005 (AI-231): This behaviour has been modified in Ada 2005. - -- It is only forced if the null_exclusion appears. + -- Ada 2005 (AI-231): In Ada95, access parameters are always non- + -- null; In Ada 2005, only if then null_exclusion is explicit. if Ada_Version < Ada_05 - or else Null_Exclusion_Present (Spec) + or else Can_Never_Be_Null (Etype (Formal_Id)) then Set_Is_Known_Non_Null (Formal_Id); Set_Can_Never_Be_Null (Formal_Id); end if; + + -- Ada 2005 (AI-231): Null-exclusion access subtype + + elsif Is_Access_Type (Etype (Formal_Id)) + and then Can_Never_Be_Null (Etype (Formal_Id)) + then + Set_Is_Known_Non_Null (Formal_Id); end if; Set_Mechanism (Formal_Id, Default_Mechanism); @@ -5511,7 +7669,6 @@ package body Sem_Ch6 is function Subtype_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is Result : Boolean; - begin Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result); return Result; @@ -5521,10 +7678,18 @@ package body Sem_Ch6 is -- Type_Conformant -- --------------------- - function Type_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is + function Type_Conformant + (New_Id : Entity_Id; + Old_Id : Entity_Id; + Skip_Controlling_Formals : Boolean := False) return Boolean + is Result : Boolean; begin - Check_Conformance (New_Id, Old_Id, Type_Conformant, False, Result); + May_Hide_Profile := False; + + Check_Conformance + (New_Id, Old_Id, Type_Conformant, False, Result, + Skip_Controlling_Formals => Skip_Controlling_Formals); return Result; end Type_Conformant; @@ -5540,7 +7705,6 @@ package body Sem_Ch6 is begin F := First_Formal (Designator); - while Present (F) loop N := N + 1;