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------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ C H 6 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2012, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Checks; use Checks; with Debug; use Debug; 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_Disp; use Exp_Disp; 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; with Nmake; use Nmake; with Opt; use Opt; with Output; use Output; with Restrict; use Restrict; with Rident; use Rident; with Rtsfind; use Rtsfind; with Sem; use Sem; with Sem_Aux; use Sem_Aux; with Sem_Cat; use Sem_Cat; with Sem_Ch3; use Sem_Ch3; with Sem_Ch4; use Sem_Ch4; with Sem_Ch5; use Sem_Ch5; with Sem_Ch8; use Sem_Ch8; with Sem_Ch10; use Sem_Ch10; with Sem_Ch12; use Sem_Ch12; with Sem_Ch13; use Sem_Ch13; with Sem_Dim; use Sem_Dim; with Sem_Disp; use Sem_Disp; with Sem_Dist; use Sem_Dist; with Sem_Elim; use Sem_Elim; with Sem_Eval; use Sem_Eval; with Sem_Mech; use Sem_Mech; with Sem_Prag; use Sem_Prag; with Sem_Res; use Sem_Res; with Sem_Util; use Sem_Util; with Sem_Type; use Sem_Type; with Sem_Warn; use Sem_Warn; with Sinput; use Sinput; with Stand; use Stand; with Sinfo; use Sinfo; with Sinfo.CN; use Sinfo.CN; with Snames; use Snames; with Stringt; use Stringt; with Style; with Stylesw; use Stylesw; with Targparm; use Targparm; with Tbuild; use Tbuild; with Uintp; use Uintp; with Urealp; use Urealp; 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 -- outer homographs. procedure Analyze_Subprogram_Body_Helper (N : Node_Id); -- Does all the real work of Analyze_Subprogram_Body. This is split out so -- that we can use RETURN but not skip the debug output at the end. procedure Analyze_Generic_Subprogram_Body (N : Node_Id; Gen_Id : Entity_Id); -- Analyze a generic subprogram body. N is the body to be analyzed, and -- Gen_Id is the defining entity Id for the corresponding spec. procedure Build_Body_To_Inline (N : Node_Id; Subp : Entity_Id); -- If a subprogram has pragma Inline and inlining is active, use generic -- machinery to build an unexpanded body for the subprogram. This body is -- subsequently used for inline expansions at call sites. If subprogram can -- be inlined (depending on size and nature of local declarations) this -- function returns true. Otherwise subprogram body is treated normally. -- If proper warnings are enabled and the subprogram contains a construct -- that cannot be inlined, the offending construct is flagged accordingly. function Can_Override_Operator (Subp : Entity_Id) return Boolean; -- Returns true if Subp can override a predefined operator. 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; 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 -- to the caller. If they do not conform, Conforms is set to False, and -- in addition, if Errmsg is True on the call, proper messages are output -- to complain about the conformance failure. If Err_Loc is non_Empty -- the error messages are placed on Err_Loc, if Err_Loc is empty, then -- error messages are placed on the appropriate part of the construct -- denoted by New_Id. If Get_Inst is true, then this is a mode conformance -- against a formal access-to-subprogram type so Get_Instance_Of must -- be called. 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. procedure Check_Returns (HSS : Node_Id; Mode : Character; 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 Check_Untagged_Equality (Eq_Op : Entity_Id); -- In Ada 2012, a primitive equality operator on an untagged record type -- must appear before the type is frozen, and have the same visibility as -- that of the type. This procedure checks that this rule is met, and -- otherwise emits an error on the subprogram declaration and a warning -- on the earlier freeze point if it is easy to locate. procedure Enter_Overloaded_Entity (S : Entity_Id); -- This procedure makes S, a new overloaded entity, into the first visible -- entity with that name. function Is_Non_Overriding_Operation (Prev_E : Entity_Id; New_E : Entity_Id) return Boolean; -- Enforce the rule given in 12.3(18): a private operation in an instance -- overrides an inherited operation only if the corresponding operation -- was overriding in the generic. This needs to be checked for primitive -- operations of types derived (in the generic unit) from formal private -- or formal derived types. procedure Make_Inequality_Operator (S : Entity_Id); -- Create the declaration for an inequality operator that is implicitly -- created by a user-defined equality operator that yields a boolean. procedure May_Need_Actuals (Fun : Entity_Id); -- 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 Process_PPCs (N : Node_Id; Spec_Id : Entity_Id; Body_Id : Entity_Id); -- Called from Analyze[_Generic]_Subprogram_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). Note that invariants and predicates may also -- provide postconditions, and are also handled in this procedure. 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_Abstract_Subprogram_Declaration -- --------------------------------------------- procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id) is Designator : constant Entity_Id := Analyze_Subprogram_Specification (Specification (N)); Scop : constant Entity_Id := Current_Scope; begin Check_SPARK_Restriction ("abstract subprogram is not allowed", N); Generate_Definition (Designator); Set_Contract (Designator, Make_Contract (Sloc (Designator))); Set_Is_Abstract_Subprogram (Designator); New_Overloaded_Entity (Designator); Check_Delayed_Subprogram (Designator); Set_Categorization_From_Scope (Designator, Scop); 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 Present (Overridden_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); Check_Eliminated (Designator); if Has_Aspects (N) then Analyze_Aspect_Specifications (N, Designator); end if; end Analyze_Abstract_Subprogram_Declaration; --------------------------------- -- Analyze_Expression_Function -- --------------------------------- procedure Analyze_Expression_Function (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); LocX : constant Source_Ptr := Sloc (Expression (N)); Expr : constant Node_Id := Expression (N); Spec : constant Node_Id := Specification (N); Def_Id : Entity_Id; Prev : Entity_Id; -- If the expression is a completion, Prev is the entity whose -- declaration is completed. Def_Id is needed to analyze the spec. New_Body : Node_Id; New_Decl : Node_Id; New_Spec : Node_Id; Ret : Node_Id; begin -- This is one of the occasions on which we transform the tree during -- semantic analysis. If this is a completion, transform the expression -- function into an equivalent subprogram body, and analyze it. -- Expression functions are inlined unconditionally. The back-end will -- determine whether this is possible. Inline_Processing_Required := True; -- Create a specification for the generated body. Types and defauts in -- the profile are copies of the spec, but new entities must be created -- for the unit name and the formals. New_Spec := New_Copy_Tree (Spec); Set_Defining_Unit_Name (New_Spec, Make_Defining_Identifier (Sloc (Defining_Unit_Name (Spec)), Chars (Defining_Unit_Name (Spec)))); if Present (Parameter_Specifications (New_Spec)) then declare Formal_Spec : Node_Id; begin Formal_Spec := First (Parameter_Specifications (New_Spec)); while Present (Formal_Spec) loop Set_Defining_Identifier (Formal_Spec, Make_Defining_Identifier (Sloc (Formal_Spec), Chars => Chars (Defining_Identifier (Formal_Spec)))); Next (Formal_Spec); end loop; end; end if; Prev := Current_Entity_In_Scope (Defining_Entity (Spec)); -- If there are previous overloadable entities with the same name, -- check whether any of them is completed by the expression function. if Present (Prev) and then Is_Overloadable (Prev) then Def_Id := Analyze_Subprogram_Specification (Spec); Prev := Find_Corresponding_Spec (N); end if; Ret := Make_Simple_Return_Statement (LocX, Expression (N)); New_Body := Make_Subprogram_Body (Loc, Specification => New_Spec, Declarations => Empty_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (LocX, Statements => New_List (Ret))); if Present (Prev) and then Ekind (Prev) = E_Generic_Function then -- If the expression completes a generic subprogram, we must create a -- separate node for the body, because at instantiation the original -- node of the generic copy must be a generic subprogram body, and -- cannot be a expression function. Otherwise we just rewrite the -- expression with the non-generic body. Insert_After (N, New_Body); Rewrite (N, Make_Null_Statement (Loc)); Set_Has_Completion (Prev, False); Analyze (N); Analyze (New_Body); Set_Is_Inlined (Prev); elsif Present (Prev) and then Comes_From_Source (Prev) then Set_Has_Completion (Prev, False); -- For navigation purposes, indicate that the function is a body Generate_Reference (Prev, Defining_Entity (N), 'b', Force => True); Rewrite (N, New_Body); Analyze (N); -- Prev is the previous entity with the same name, but it is can -- be an unrelated spec that is not completed by the expression -- function. In that case the relevant entity is the one in the body. -- Not clear that the backend can inline it in this case ??? if Has_Completion (Prev) then Set_Is_Inlined (Prev); -- The formals of the expression function are body formals, -- and do not appear in the ali file, which will only contain -- references to the formals of the original subprogram spec. declare F1 : Entity_Id; F2 : Entity_Id; begin F1 := First_Formal (Def_Id); F2 := First_Formal (Prev); while Present (F1) loop Set_Spec_Entity (F1, F2); Next_Formal (F1); Next_Formal (F2); end loop; end; else Set_Is_Inlined (Defining_Entity (New_Body)); end if; -- If this is not a completion, create both a declaration and a body, so -- that the expression can be inlined whenever possible. else New_Decl := Make_Subprogram_Declaration (Loc, Specification => Spec); Rewrite (N, New_Decl); Analyze (N); Set_Is_Inlined (Defining_Entity (New_Decl)); -- To prevent premature freeze action, insert the new body at the end -- of the current declarations, or at the end of the package spec. -- However, resolve usage names now, to prevent spurious visibility -- on later entities. declare Decls : List_Id := List_Containing (N); Par : constant Node_Id := Parent (Decls); Id : constant Entity_Id := Defining_Entity (New_Decl); begin if Nkind (Par) = N_Package_Specification and then Decls = Visible_Declarations (Par) and then Present (Private_Declarations (Par)) and then not Is_Empty_List (Private_Declarations (Par)) then Decls := Private_Declarations (Par); end if; Insert_After (Last (Decls), New_Body); Push_Scope (Id); Install_Formals (Id); Preanalyze_Spec_Expression (Expression (Ret), Etype (Id)); End_Scope; end; end if; -- If the return expression is a static constant, we suppress warning -- messages on unused formals, which in most cases will be noise. Set_Is_Trivial_Subprogram (Defining_Entity (New_Body), Is_OK_Static_Expression (Expr)); end Analyze_Expression_Function; ---------------------------------------- -- 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 -- ---------------------------- procedure Analyze_Function_Call (N : Node_Id) is P : constant Node_Id := Name (N); Actuals : constant List_Id := Parameter_Associations (N); Actual : Node_Id; begin Analyze (P); -- A call of the form A.B (X) may be an Ada 2005 call, which is -- rewritten as B (A, X). If the rewriting is successful, the call -- has been analyzed and we just return. if Nkind (P) = N_Selected_Component and then Name (N) /= P and then Is_Rewrite_Substitution (N) and then Present (Etype (N)) then return; end if; -- If error analyzing name, then set Any_Type as result type and return if Etype (P) = Any_Type then Set_Etype (N, Any_Type); return; end if; -- Otherwise analyze the parameters if Present (Actuals) then Actual := First (Actuals); while Present (Actual) loop Analyze (Actual); Check_Parameterless_Call (Actual); Next (Actual); end loop; end if; 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. ??? -- A limited interface that is not immutably limited is OK. if Is_Limited_Interface (R_Type) and then not (Is_Task_Interface (R_Type) or else Is_Protected_Interface (R_Type) or else Is_Synchronized_Interface (R_Type)) then null; elsif Is_Limited_Type (R_Type) and then not Is_Interface (R_Type) and then Comes_From_Source (N) and then not In_Instance_Body and then not OK_For_Limited_Init_In_05 (R_Type, Expr) then -- Error in Ada 2005 if Ada_Version >= Ada_2005 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_Immutably_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. -- In a generic context, simplify the warning because it makes -- no sense to discuss pass-by-reference or copy. elsif Warn_On_Ada_2005_Compatibility or GNAT_Mode then if Inside_A_Generic then Error_Msg_N ("return of limited object not permitted in Ada 2005 " & "(RM-2005 6.5(5.5/2))?", Expr); elsif Is_Immutably_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; if not Inside_A_Generic then Error_Msg_N ("\consider switching to return of access type", Expr); Explain_Limited_Type (R_Type, Expr); end if; 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 (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 cascaded 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 this is an access to subprogram the signatures must match. if R_Type_Is_Anon_Access then if R_Stm_Type_Is_Anon_Access then if Ekind (Designated_Type (R_Stm_Type)) /= E_Subprogram_Type 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 -- For two anonymous access to subprogram types, the -- types themselves must be type conformant. if not Conforming_Types (R_Stm_Type, R_Type, Fully_Conformant) then Error_Msg_N ("subtype must statically match function result subtype", Subtype_Ind); end if; end if; else Error_Msg_N ("must use anonymous access type", Subtype_Ind); end if; -- If the return object is of an anonymous access type, then report -- an error if the function's result type is not also anonymous. elsif R_Stm_Type_Is_Anon_Access and then not R_Type_Is_Anon_Access then Error_Msg_N ("anonymous access not allowed for function with " & "named access result", Subtype_Ind); -- Subtype indication case: check that the return object's type is -- covered by the result type, and that the subtypes statically match -- when the result subtype is constrained. Also handle record types -- with unknown discriminants for which we have built the underlying -- record view. Coverage is needed to allow specific-type return -- objects when the result type is class-wide (see AI05-32). elsif Covers (Base_Type (R_Type), Base_Type (R_Stm_Type)) or else (Is_Underlying_Record_View (Base_Type (R_Stm_Type)) and then Covers (Base_Type (R_Type), Underlying_Record_View (Base_Type (R_Stm_Type)))) then -- A null exclusion may be present on the return type, on the -- function specification, on the object declaration or on the -- subtype itself. 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; -- AI05-103: for elementary types, subtypes must statically match if Is_Constrained (R_Type) or else Is_Access_Type (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; elsif Etype (Base_Type (R_Type)) = R_Stm_Type and then Is_Null_Extension (Base_Type (R_Type)) 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); -- Guard against a malformed expression. The parser may have tried to -- recover but the node is not analyzable. if Nkind (Expr) = N_Error then Set_Etype (Expr, Any_Type); Expander_Mode_Save_And_Set (False); return; else -- The resolution of a controlled [extension] aggregate associated -- with a return statement creates a temporary which needs to be -- finalized on function exit. Wrap the return statement inside a -- block so that the finalization machinery can detect this case. -- This early expansion is done only when the return statement is -- not part of a handled sequence of statements. if Nkind_In (Expr, N_Aggregate, N_Extension_Aggregate) and then Needs_Finalization (R_Type) and then Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements then Rewrite (N, Make_Block_Statement (Loc, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List (Relocate_Node (N))))); Analyze (N); return; end if; Analyze_And_Resolve (Expr, R_Type); Check_Limited_Return (Expr); end if; -- RETURN only allowed in SPARK as the last statement in function if Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements and then (Nkind (Parent (Parent (N))) /= N_Subprogram_Body or else Present (Next (N))) then Check_SPARK_Restriction ("RETURN should be the last statement in function", N); end if; else Check_SPARK_Restriction ("extended RETURN is not allowed", N); -- 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. Set_Is_Return_Object (Defining_Identifier (Obj_Decl)); Analyze (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; -- Mark the return object as referenced, since the return is an -- implicit reference of the object. Set_Referenced (Defining_Identifier (Obj_Decl)); 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 associated -- 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_2005 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_2005 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; -- Check incorrect use of dynamically tagged expression if Is_Tagged_Type (R_Type) then Check_Dynamically_Tagged_Expression (Expr => Expr, Typ => R_Type, Related_Nod => N); 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_2005 or else Debug_Flag_Dot_L) and then Is_Immutably_Limited_Type (Etype (Scope_Id)) and then Object_Access_Level (Expr) > Subprogram_Access_Level (Scope_Id) then -- Suppress the message in a generic, where the rewriting -- is irrelevant. if Inside_A_Generic then null; else 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; 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; -- Apply checks suggested by AI05-0144 (dangerous order dependence) Check_Order_Dependence; end if; end Analyze_Function_Return; ------------------------------------- -- Analyze_Generic_Subprogram_Body -- ------------------------------------- procedure Analyze_Generic_Subprogram_Body (N : Node_Id; Gen_Id : Entity_Id) is Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Id); Kind : constant Entity_Kind := Ekind (Gen_Id); Body_Id : Entity_Id; New_N : Node_Id; Spec : Node_Id; begin -- Copy body and disable expansion while analyzing the generic For a -- stub, do not copy the stub (which would load the proper body), this -- will be done when the proper body is analyzed. if Nkind (N) /= N_Subprogram_Body_Stub then New_N := Copy_Generic_Node (N, Empty, Instantiating => False); Rewrite (N, New_N); Start_Generic; end if; Spec := Specification (N); -- Within the body of the generic, the subprogram is callable, and -- behaves like the corresponding non-generic unit. Body_Id := Defining_Entity (Spec); if Kind = E_Generic_Procedure and then Nkind (Spec) /= N_Procedure_Specification then Error_Msg_N ("invalid body for generic procedure ", Body_Id); return; elsif Kind = E_Generic_Function and then Nkind (Spec) /= N_Function_Specification then Error_Msg_N ("invalid body for generic function ", Body_Id); return; end if; Set_Corresponding_Body (Gen_Decl, Body_Id); if Has_Completion (Gen_Id) and then Nkind (Parent (N)) /= N_Subunit then Error_Msg_N ("duplicate generic body", N); return; else Set_Has_Completion (Gen_Id); end if; if Nkind (N) = N_Subprogram_Body_Stub then Set_Ekind (Defining_Entity (Specification (N)), Kind); else Set_Corresponding_Spec (N, Gen_Id); end if; if Nkind (Parent (N)) = N_Compilation_Unit then Set_Cunit_Entity (Current_Sem_Unit, Defining_Entity (N)); end if; -- Make generic parameters immediately visible in the body. They are -- needed to process the formals declarations. Then make the formals -- visible in a separate step. Push_Scope (Gen_Id); declare E : Entity_Id; First_Ent : Entity_Id; begin First_Ent := First_Entity (Gen_Id); E := First_Ent; while Present (E) and then not Is_Formal (E) loop Install_Entity (E); Next_Entity (E); end loop; Set_Use (Generic_Formal_Declarations (Gen_Decl)); -- Now generic formals are visible, and the specification can be -- analyzed, for subsequent conformance check. Body_Id := Analyze_Subprogram_Specification (Spec); -- Make formal parameters visible if Present (E) then -- E is the first formal parameter, we loop through the formals -- installing them so that they will be visible. Set_First_Entity (Gen_Id, E); while Present (E) loop Install_Entity (E); Next_Formal (E); end loop; end if; -- 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_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 -- No body to analyze, so restore state of generic unit Set_Ekind (Gen_Id, Kind); Set_Ekind (Body_Id, Kind); if Present (First_Ent) then Set_First_Entity (Gen_Id, First_Ent); end if; End_Scope; return; end if; -- If this is a compilation unit, it must be made visible explicitly, -- because the compilation of the declaration, unlike other library -- unit declarations, does not. If it is not a unit, the following -- is redundant but harmless. 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); -- Deal with preconditions and postconditions. In formal verification -- mode, we keep pre- and postconditions attached to entities rather -- than inserted in the code, in order to facilitate a distinct -- treatment for them. if not Alfa_Mode then Process_PPCs (N, Gen_Id, Body_Id); end if; -- If the generic unit carries pre- or post-conditions, copy them -- to the original generic tree, so that they are properly added -- to any instantiation. declare Orig : constant Node_Id := Original_Node (N); Cond : Node_Id; begin Cond := First (Declarations (N)); while Present (Cond) loop if Nkind (Cond) = N_Pragma and then Pragma_Name (Cond) = Name_Check then Prepend (New_Copy_Tree (Cond), Declarations (Orig)); elsif Nkind (Cond) = N_Pragma and then Pragma_Name (Cond) = Name_Postcondition then Set_Ekind (Defining_Entity (Orig), Ekind (Gen_Id)); Prepend (New_Copy_Tree (Cond), Declarations (Orig)); else exit; end if; Next (Cond); end loop; end; Analyze_Declarations (Declarations (N)); Check_Completion; Analyze (Handled_Statement_Sequence (N)); Save_Global_References (Original_Node (N)); -- Prior to exiting the scope, include generic formals again (if any -- are present) in the set of local entities. if Present (First_Ent) then Set_First_Entity (Gen_Id, First_Ent); end if; Check_References (Gen_Id); end; Process_End_Label (Handled_Statement_Sequence (N), 't', Current_Scope); End_Scope; Check_Subprogram_Order (N); -- Outside of its body, unit is generic again Set_Ekind (Gen_Id, Kind); Generate_Reference (Gen_Id, Body_Id, 'b', Set_Ref => False); if Style_Check then Style.Check_Identifier (Body_Id, Gen_Id); end if; End_Generic; end Analyze_Generic_Subprogram_Body; ----------------------------- -- Analyze_Operator_Symbol -- ----------------------------- -- An operator symbol such as "+" or "and" may appear in context where the -- literal denotes an entity name, such as "+"(x, y) or in context when it -- is just a string, as in (conjunction = "or"). In these cases the parser -- generates this node, and the semantics does the disambiguation. Other -- such case are actuals in an instantiation, the generic unit in an -- instantiation, and pragma arguments. procedure Analyze_Operator_Symbol (N : Node_Id) is Par : constant Node_Id := Parent (N); begin 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_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) then Find_Direct_Name (N); else Change_Operator_Symbol_To_String_Literal (N); Analyze (N); end if; end Analyze_Operator_Symbol; ----------------------------------- -- Analyze_Parameter_Association -- ----------------------------------- procedure Analyze_Parameter_Association (N : Node_Id) is begin Analyze (Explicit_Actual_Parameter (N)); end Analyze_Parameter_Association; ---------------------------- -- Analyze_Procedure_Call -- ---------------------------- procedure Analyze_Procedure_Call (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); P : constant Node_Id := Name (N); Actuals : constant List_Id := Parameter_Associations (N); Actual : Node_Id; New_N : Node_Id; procedure Analyze_Call_And_Resolve; -- Do Analyze and Resolve calls for procedure call -- At end, check illegal order dependence. ------------------------------ -- Analyze_Call_And_Resolve -- ------------------------------ procedure Analyze_Call_And_Resolve is begin if Nkind (N) = N_Procedure_Call_Statement then Analyze_Call (N); Resolve (N, Standard_Void_Type); -- Apply checks suggested by AI05-0144 Check_Order_Dependence; else Analyze (N); end if; end Analyze_Call_And_Resolve; -- Start of processing for Analyze_Procedure_Call begin -- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote -- a procedure call or an entry call. The prefix may denote an access -- to subprogram type, in which case an implicit dereference applies. -- If the prefix is an indexed component (without implicit dereference) -- then the construct denotes a call to a member of an entire family. -- If the prefix is a simple name, it may still denote a call to a -- parameterless member of an entry family. Resolution of these various -- interpretations is delicate. 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 there is an error analyzing the name (which may have been -- rewritten if the original call was in prefix notation) then error -- has been emitted already, mark node and return. if Error_Posted (N) or else Etype (Name (N)) = Any_Type then Set_Etype (N, Any_Type); return; end if; -- Otherwise analyze the parameters if Present (Actuals) then Actual := First (Actuals); while Present (Actual) loop Analyze (Actual); Check_Parameterless_Call (Actual); Next (Actual); end loop; end if; -- Special processing for Elab_Spec, Elab_Body and Elab_Subp_Body calls if Nkind (P) = N_Attribute_Reference and then (Attribute_Name (P) = Name_Elab_Spec or else Attribute_Name (P) = Name_Elab_Body or else Attribute_Name (P) = Name_Elab_Subp_Body) then if Present (Actuals) then Error_Msg_N ("no parameters allowed for this call", First (Actuals)); return; end if; Set_Etype (N, Standard_Void_Type); Set_Analyzed (N); elsif Is_Entity_Name (P) and then Is_Record_Type (Etype (Entity (P))) and then Remote_AST_I_Dereference (P) then return; elsif Is_Entity_Name (P) and then Ekind (Entity (P)) /= E_Entry_Family then if Is_Access_Type (Etype (P)) and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type and then No (Actuals) and then Comes_From_Source (N) then Error_Msg_N ("missing explicit dereference in call", N); end if; Analyze_Call_And_Resolve; -- If the prefix is the simple name of an entry family, this is -- a parameterless call from within the task body itself. elsif Is_Entity_Name (P) and then Nkind (P) = N_Identifier and then Ekind (Entity (P)) = E_Entry_Family and then Present (Actuals) and then No (Next (First (Actuals))) then -- Can be call to parameterless entry family. What appears to be the -- sole argument is in fact the entry index. Rewrite prefix of node -- accordingly. Source representation is unchanged by this -- transformation. New_N := Make_Indexed_Component (Loc, Prefix => Make_Selected_Component (Loc, Prefix => New_Occurrence_Of (Scope (Entity (P)), Loc), Selector_Name => New_Occurrence_Of (Entity (P), Loc)), Expressions => Actuals); Set_Name (N, New_N); Set_Etype (New_N, Standard_Void_Type); Set_Parameter_Associations (N, No_List); Analyze_Call_And_Resolve; elsif Nkind (P) = N_Explicit_Dereference then if Ekind (Etype (P)) = E_Subprogram_Type then Analyze_Call_And_Resolve; else Error_Msg_N ("expect access to procedure in call", P); end if; -- The name can be a selected component or an indexed component that -- yields an access to subprogram. Such a prefix is legal if the call -- has parameter associations. elsif Is_Access_Type (Etype (P)) and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type then if Present (Actuals) then Analyze_Call_And_Resolve; else Error_Msg_N ("missing explicit dereference in call ", N); end if; -- If not an access to subprogram, then the prefix must resolve to the -- name of an entry, entry family, or protected operation. -- For the case of a simple entry call, P is a selected component where -- the prefix is the task and the selector name is the entry. A call to -- a protected procedure will have the same syntax. If the protected -- object contains overloaded operations, the entity may appear as a -- function, the context will select the operation whose type is Void. elsif Nkind (P) = N_Selected_Component and then (Ekind (Entity (Selector_Name (P))) = E_Entry or else Ekind (Entity (Selector_Name (P))) = E_Procedure or else Ekind (Entity (Selector_Name (P))) = E_Function) then Analyze_Call_And_Resolve; elsif Nkind (P) = N_Selected_Component and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family and then Present (Actuals) and then No (Next (First (Actuals))) then -- Can be call to parameterless entry family. What appears to be the -- sole argument is in fact the entry index. Rewrite prefix of node -- accordingly. Source representation is unchanged by this -- transformation. New_N := Make_Indexed_Component (Loc, Prefix => New_Copy (P), Expressions => Actuals); Set_Name (N, New_N); Set_Etype (New_N, Standard_Void_Type); Set_Parameter_Associations (N, No_List); Analyze_Call_And_Resolve; -- For the case of a reference to an element of an entry family, P is -- an indexed component whose prefix is a selected component (task and -- entry family), and whose index is the entry family index. elsif Nkind (P) = N_Indexed_Component and then Nkind (Prefix (P)) = N_Selected_Component and then Ekind (Entity (Selector_Name (Prefix (P)))) = E_Entry_Family then Analyze_Call_And_Resolve; -- If the prefix is the name of an entry family, it is a call from -- within the task body itself. elsif Nkind (P) = N_Indexed_Component and then Nkind (Prefix (P)) = N_Identifier and then Ekind (Entity (Prefix (P))) = E_Entry_Family then New_N := Make_Selected_Component (Loc, Prefix => New_Occurrence_Of (Scope (Entity (Prefix (P))), Loc), Selector_Name => New_Occurrence_Of (Entity (Prefix (P)), Loc)); Rewrite (Prefix (P), New_N); Analyze (P); Analyze_Call_And_Resolve; -- In Ada 2012. a qualified expression is a name, but it cannot be a -- procedure name, so the construct can only be a qualified expression. elsif Nkind (P) = N_Qualified_Expression and then Ada_Version >= Ada_2012 then Rewrite (N, Make_Code_Statement (Loc, Expression => P)); Analyze (N); -- Anything else is an error else 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 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 <expression>;" -- 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, loops, -- and postconditions. for J in reverse 0 .. Scope_Stack.Last loop Result := Scope_Stack.Table (J).Entity; exit when not Ekind_In (Result, E_Block, E_Loop) and then Chars (Result) /= Name_uPostconditions; 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. Don't complain about the -- implicitly-generated return that is placed at the end. if No_Return (Scope_Id) and then Comes_From_Source (N) 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 if Nkind (N) = N_Extended_Return_Statement then Error_Msg_N ("extended return statement cannot be nested (use `RETURN;`)", N); -- Case of a simple return statement with a value inside extended -- return statement. else Error_Msg_N ("return nested in extended return statement cannot return " & "value (use `RETURN;`)", N); end if; end if; else Error_Msg_N ("illegal context for return statement", N); end if; if Ekind_In (Kind, E_Function, E_Generic_Function) then Analyze_Function_Return (N); elsif Ekind_In (Kind, E_Procedure, E_Generic_Procedure) then Set_Return_Present (Scope_Id); 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); Analyze_Dimension (N); end Analyze_Return_Statement; ------------------------------------- -- Analyze_Simple_Return_Statement -- ------------------------------------- procedure Analyze_Simple_Return_Statement (N : Node_Id) is begin if Present (Expression (N)) then Mark_Coextensions (N, Expression (N)); end if; Analyze_Return_Statement (N); end Analyze_Simple_Return_Statement; ------------------------- -- Analyze_Return_Type -- ------------------------- procedure Analyze_Return_Type (N : Node_Id) is Designator : constant Entity_Id := Defining_Entity (N); Typ : Entity_Id := Empty; begin -- Normal case where result definition does not indicate an error if Result_Definition (N) /= Error then if Nkind (Result_Definition (N)) = N_Access_Definition then Check_SPARK_Restriction ("access result is not allowed", Result_Definition (N)); -- Ada 2005 (AI-254): Handle anonymous access to subprograms declare AD : constant Node_Id := Access_To_Subprogram_Definition (Result_Definition (N)); begin if Present (AD) and then Protected_Present (AD) then Typ := Replace_Anonymous_Access_To_Protected_Subprogram (N); else Typ := Access_Definition (N, Result_Definition (N)); end if; end; Set_Parent (Typ, Result_Definition (N)); Set_Is_Local_Anonymous_Access (Typ); Set_Etype (Designator, Typ); -- Ada 2005 (AI-231): Ensure proper usage of null exclusion Null_Exclusion_Static_Checks (N); -- Subtype_Mark case else Find_Type (Result_Definition (N)); Typ := Entity (Result_Definition (N)); Set_Etype (Designator, Typ); -- Unconstrained array as result is not allowed in SPARK if Is_Array_Type (Typ) and then not Is_Constrained (Typ) then Check_SPARK_Restriction ("returning an unconstrained array is not allowed", Result_Definition (N)); end if; -- Ada 2005 (AI-231): Ensure proper usage of null exclusion Null_Exclusion_Static_Checks (N); -- If a null exclusion is imposed on the result type, then create -- a null-excluding itype (an access subtype) and use it as the -- function's Etype. Note that the null exclusion checks are done -- right before this, because they don't get applied to types that -- do not come from source. if Is_Access_Type (Typ) and then Null_Exclusion_Present (N) then Set_Etype (Designator, Create_Null_Excluding_Itype (T => Typ, Related_Nod => N, Scope_Id => Scope (Current_Scope))); -- The new subtype must be elaborated before use because -- it is visible outside of the function. However its base -- type may not be frozen yet, so the reference that will -- force elaboration must be attached to the freezing of -- the base type. -- If the return specification appears on a proper body, -- the subtype will have been created already on the spec. if Is_Frozen (Typ) then if Nkind (Parent (N)) = N_Subprogram_Body and then Nkind (Parent (Parent (N))) = N_Subunit then null; else Build_Itype_Reference (Etype (Designator), Parent (N)); end if; else Ensure_Freeze_Node (Typ); declare IR : constant Node_Id := Make_Itype_Reference (Sloc (N)); begin Set_Itype (IR, Etype (Designator)); Append_Freeze_Actions (Typ, New_List (IR)); end; end if; else Set_Etype (Designator, Typ); end if; if Ekind (Typ) = E_Incomplete_Type and then Is_Value_Type (Typ) then null; elsif Ekind (Typ) = E_Incomplete_Type or else (Is_Class_Wide_Type (Typ) and then Ekind (Root_Type (Typ)) = E_Incomplete_Type) then -- AI05-0151: Tagged incomplete types are allowed in all formal -- parts. Untagged incomplete types are not allowed in bodies. if Ada_Version >= Ada_2012 then if Is_Tagged_Type (Typ) then null; elsif Nkind_In (Parent (Parent (N)), N_Accept_Statement, N_Entry_Body, N_Subprogram_Body) then Error_Msg_NE ("invalid use of untagged incomplete type&", Designator, Typ); end if; -- The type must be completed in the current package. This -- is checked at the end of the package declaraton, when -- Taft-amendment types are identified. If the return type -- is class-wide, there is no required check, the type can -- be a bona fide TAT. if Ekind (Scope (Current_Scope)) = E_Package and then In_Private_Part (Scope (Current_Scope)) and then not Is_Class_Wide_Type (Typ) then Append_Elmt (Designator, Private_Dependents (Typ)); end if; else Error_Msg_NE ("invalid use of incomplete type&", Designator, Typ); end if; end if; end if; -- Case where result definition does indicate an error else Set_Etype (Designator, Any_Type); end if; end Analyze_Return_Type; ----------------------------- -- Analyze_Subprogram_Body -- ----------------------------- procedure Analyze_Subprogram_Body (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Body_Spec : constant Node_Id := Specification (N); Body_Id : constant Entity_Id := Defining_Entity (Body_Spec); begin if Debug_Flag_C then Write_Str ("==> subprogram body "); Write_Name (Chars (Body_Id)); Write_Str (" from "); Write_Location (Loc); Write_Eol; Indent; end if; Trace_Scope (N, Body_Id, " Analyze subprogram: "); -- The real work is split out into the helper, so it can do "return;" -- without skipping the debug output: Analyze_Subprogram_Body_Helper (N); if Debug_Flag_C then Outdent; Write_Str ("<== subprogram body "); Write_Name (Chars (Body_Id)); Write_Str (" from "); Write_Location (Loc); Write_Eol; end if; end Analyze_Subprogram_Body; ------------------------------------ -- Analyze_Subprogram_Body_Helper -- ------------------------------------ -- This procedure is called for regular subprogram bodies, generic bodies, -- and for subprogram stubs of both kinds. In the case of stubs, only the -- specification matters, and is used to create a proper declaration for -- the subprogram, or to perform conformance checks. procedure Analyze_Subprogram_Body_Helper (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Body_Deleted : constant Boolean := False; Body_Spec : constant Node_Id := Specification (N); Body_Id : Entity_Id := Defining_Entity (Body_Spec); Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id); Conformant : Boolean; HSS : Node_Id; 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 Check_Missing_Return; -- Checks for a function with a no return statements, and also performs -- the warning checks implemented by Check_Returns. In formal mode, also -- verify that a function ends with a RETURN and that a procedure does -- not contain any RETURN. function Disambiguate_Spec return Entity_Id; -- When a primitive is declared between the private view and the full -- view of a concurrent type which implements an interface, a special -- mechanism is used to find the corresponding spec of the primitive -- body. procedure Exchange_Limited_Views (Subp_Id : Entity_Id); -- Ada 2012 (AI05-0151): Detect whether the profile of Subp_Id contains -- incomplete types coming from a limited context and swap their limited -- views with the non-limited ones. function Is_Private_Concurrent_Primitive (Subp_Id : Entity_Id) return Boolean; -- Determine whether subprogram Subp_Id is a primitive of a concurrent -- type that implements an interface and has a private view. 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; Par : 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 not Is_Thunk (Scop) and then (Has_Task (Designated_Type (Etype (Scop))) or else (Is_Class_Wide_Type (Designated_Type (Etype (Scop))) and then Is_Limited_Record (Designated_Type (Etype (Scop))))) and then Expander_Active -- Avoid cases with no tasking support and then RTE_Available (RE_Current_Master) and then not Restriction_Active (No_Task_Hierarchy) 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; Set_Master_Id (Etype (Scop), Defining_Identifier (Decl)); Set_Has_Master_Entity (Scop); -- Now mark the containing scope as a task master Par := N; while Nkind (Par) /= N_Compilation_Unit loop Par := Parent (Par); pragma Assert (Present (Par)); -- If we fall off the top, we are at the outer level, and -- the environment task is our effective master, so nothing -- to mark. if Nkind_In (Par, N_Task_Body, N_Block_Statement, N_Subprogram_Body) then Set_Is_Task_Master (Par, True); exit; end if; end loop; 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; -- True when N is a pragma Inline or Inline_Always that applies -- to this subprogram. ----------------------- -- 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; -- Start of processing for Check_Inline_Pragma begin 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); 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 In_Same_List (N, 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; -------------------------- -- Check_Missing_Return -- -------------------------- procedure Check_Missing_Return is Id : Entity_Id; Missing_Ret : Boolean; begin if Nkind (Body_Spec) = N_Function_Specification then if Present (Spec_Id) then Id := Spec_Id; else Id := Body_Id; end if; if Return_Present (Id) then Check_Returns (HSS, 'F', Missing_Ret); if Missing_Ret then Set_Has_Missing_Return (Id); end if; elsif (Is_Generic_Subprogram (Id) or else not Is_Machine_Code_Subprogram (Id)) and then not Body_Deleted then Error_Msg_N ("missing RETURN statement in function body", N); end if; -- If procedure with No_Return, check returns elsif Nkind (Body_Spec) = N_Procedure_Specification and then Present (Spec_Id) and then No_Return (Spec_Id) then Check_Returns (HSS, 'P', Missing_Ret, Spec_Id); end if; -- Special checks in SPARK mode if Nkind (Body_Spec) = N_Function_Specification then -- In SPARK mode, last statement of a function should be a return declare Stat : constant Node_Id := Last_Source_Statement (HSS); begin if Present (Stat) and then not Nkind_In (Stat, N_Simple_Return_Statement, N_Extended_Return_Statement) then Check_SPARK_Restriction ("last statement in function should be RETURN", Stat); end if; end; -- In SPARK mode, verify that a procedure has no return elsif Nkind (Body_Spec) = N_Procedure_Specification then if Present (Spec_Id) then Id := Spec_Id; else Id := Body_Id; end if; -- Would be nice to point to return statement here, can we -- borrow the Check_Returns procedure here ??? if Return_Present (Id) then Check_SPARK_Restriction ("procedure should not have RETURN", N); end if; end if; end Check_Missing_Return; ----------------------- -- Disambiguate_Spec -- ----------------------- function Disambiguate_Spec return Entity_Id is Priv_Spec : Entity_Id; Spec_N : Entity_Id; procedure Replace_Types (To_Corresponding : Boolean); -- Depending on the flag, replace the type of formal parameters of -- Body_Id if it is a concurrent type implementing interfaces with -- the corresponding record type or the other way around. procedure Replace_Types (To_Corresponding : Boolean) is Formal : Entity_Id; Formal_Typ : Entity_Id; begin Formal := First_Formal (Body_Id); while Present (Formal) loop Formal_Typ := Etype (Formal); if Is_Class_Wide_Type (Formal_Typ) then Formal_Typ := Root_Type (Formal_Typ); end if; -- From concurrent type to corresponding record if To_Corresponding then if Is_Concurrent_Type (Formal_Typ) and then Present (Corresponding_Record_Type (Formal_Typ)) and then Present (Interfaces ( Corresponding_Record_Type (Formal_Typ))) then Set_Etype (Formal, Corresponding_Record_Type (Formal_Typ)); end if; -- From corresponding record to concurrent type else if Is_Concurrent_Record_Type (Formal_Typ) and then Present (Interfaces (Formal_Typ)) then Set_Etype (Formal, Corresponding_Concurrent_Type (Formal_Typ)); end if; end if; Next_Formal (Formal); end loop; end Replace_Types; -- Start of processing for Disambiguate_Spec begin -- Try to retrieve the specification of the body as is. All error -- messages are suppressed because the body may not have a spec in -- its current state. Spec_N := Find_Corresponding_Spec (N, False); -- It is possible that this is the body of a primitive declared -- between a private and a full view of a concurrent type. The -- controlling parameter of the spec carries the concurrent type, -- not the corresponding record type as transformed by Analyze_ -- Subprogram_Specification. In such cases, we undo the change -- made by the analysis of the specification and try to find the -- spec again. -- Note that wrappers already have their corresponding specs and -- bodies set during their creation, so if the candidate spec is -- a wrapper, then we definitely need to swap all types to their -- original concurrent status. if No (Spec_N) or else Is_Primitive_Wrapper (Spec_N) then -- Restore all references of corresponding record types to the -- original concurrent types. Replace_Types (To_Corresponding => False); Priv_Spec := Find_Corresponding_Spec (N, False); -- The current body truly belongs to a primitive declared between -- a private and a full view. We leave the modified body as is, -- and return the true spec. if Present (Priv_Spec) and then Is_Private_Primitive (Priv_Spec) then return Priv_Spec; end if; -- In case that this is some sort of error, restore the original -- state of the body. Replace_Types (To_Corresponding => True); end if; return Spec_N; end Disambiguate_Spec; ---------------------------- -- Exchange_Limited_Views -- ---------------------------- procedure Exchange_Limited_Views (Subp_Id : Entity_Id) is procedure Detect_And_Exchange (Id : Entity_Id); -- Determine whether Id's type denotes an incomplete type associated -- with a limited with clause and exchange the limited view with the -- non-limited one. ------------------------- -- Detect_And_Exchange -- ------------------------- procedure Detect_And_Exchange (Id : Entity_Id) is Typ : constant Entity_Id := Etype (Id); begin if Ekind (Typ) = E_Incomplete_Type and then From_With_Type (Typ) and then Present (Non_Limited_View (Typ)) then Set_Etype (Id, Non_Limited_View (Typ)); end if; end Detect_And_Exchange; -- Local variables Formal : Entity_Id; -- Start of processing for Exchange_Limited_Views begin if No (Subp_Id) then return; -- Do not process subprogram bodies as they already use the non- -- limited view of types. elsif not Ekind_In (Subp_Id, E_Function, E_Procedure) then return; end if; -- Examine all formals and swap views when applicable Formal := First_Formal (Subp_Id); while Present (Formal) loop Detect_And_Exchange (Formal); Next_Formal (Formal); end loop; -- Process the return type of a function if Ekind (Subp_Id) = E_Function then Detect_And_Exchange (Subp_Id); end if; end Exchange_Limited_Views; ------------------------------------- -- Is_Private_Concurrent_Primitive -- ------------------------------------- function Is_Private_Concurrent_Primitive (Subp_Id : Entity_Id) return Boolean is Formal_Typ : Entity_Id; begin if Present (First_Formal (Subp_Id)) then Formal_Typ := Etype (First_Formal (Subp_Id)); if Is_Concurrent_Record_Type (Formal_Typ) then if Is_Class_Wide_Type (Formal_Typ) then Formal_Typ := Root_Type (Formal_Typ); end if; Formal_Typ := Corresponding_Concurrent_Type (Formal_Typ); end if; -- The type of the first formal is a concurrent tagged type with -- a private view. return Is_Concurrent_Type (Formal_Typ) and then Is_Tagged_Type (Formal_Typ) and then Has_Private_Declaration (Formal_Typ); end if; return False; end Is_Private_Concurrent_Primitive; ---------------------------- -- 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 Present (Overridden_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 Present (Overridden_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 Error_Msg_NE ("subprogram & overrides predefined operator ", Body_Spec, Spec_Id); -- If this is not a primitive operation or protected subprogram, -- then the overriding indicator is altogether illegal. elsif not Is_Primitive (Spec_Id) and then Ekind (Scope (Spec_Id)) /= E_Protected_Type then Error_Msg_N ("overriding indicator only allowed " & "if subprogram is primitive", Body_Spec); end if; elsif Style_Check and then Present (Overridden_Operation (Spec_Id)) then pragma Assert (Unit_Declaration_Node (Body_Id) = N); Style.Missing_Overriding (N, Body_Id); elsif Style_Check and then Can_Override_Operator (Spec_Id) and then not Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Spec_Id))) then pragma Assert (Unit_Declaration_Node (Body_Id) = N); Style.Missing_Overriding (N, Body_Id); end if; end Verify_Overriding_Indicator; -- Start of processing for Analyze_Subprogram_Body_Helper begin -- Generic subprograms are handled separately. They always have a -- generic specification. Determine whether current scope has a -- previous declaration. -- If the subprogram body is defined within an instance of the same -- name, the instance appears as a package renaming, and will be hidden -- within the subprogram. if Present (Prev_Id) and then not Is_Overloadable (Prev_Id) and then (Nkind (Parent (Prev_Id)) /= N_Package_Renaming_Declaration or else Comes_From_Source (Prev_Id)) then if Is_Generic_Subprogram (Prev_Id) then Spec_Id := Prev_Id; Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id)); Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id)); Analyze_Generic_Subprogram_Body (N, Spec_Id); if Nkind (N) = N_Subprogram_Body then HSS := Handled_Statement_Sequence (N); Check_Missing_Return; end if; return; else -- Previous entity conflicts with subprogram name. Attempting to -- enter name will post error. Enter_Name (Body_Id); return; end if; -- Non-generic case, find the subprogram declaration, if one was seen, -- or enter new overloaded entity in the current scope. If the -- Current_Entity is the Body_Id itself, the unit is being analyzed as -- part of the context of one of its subunits. No need to redo the -- analysis. elsif Prev_Id = Body_Id and then Has_Completion (Body_Id) then return; else Body_Id := Analyze_Subprogram_Specification (Body_Spec); if Nkind (N) = N_Subprogram_Body_Stub or else No (Corresponding_Spec (N)) then if Is_Private_Concurrent_Primitive (Body_Id) then Spec_Id := Disambiguate_Spec; else Spec_Id := Find_Corresponding_Spec (N); end if; -- If this is a duplicate body, no point in analyzing it if Error_Posted (N) then return; end if; -- A subprogram body should cause freezing of its own declaration, -- but if there was no previous explicit declaration, then the -- 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 spec are compilation units. -- Finally, if the return type is an anonymous access to protected -- subprogram, it must be frozen before the body because its -- expansion has generated an equivalent type that is used when -- elaborating the body. -- An exception in the case of Ada 2012, AI05-177: The bodies -- created for expression functions do not freeze. if No (Spec_Id) and then Nkind (Original_Node (N)) /= N_Expression_Function then Freeze_Before (N, Body_Id); elsif Nkind (Parent (N)) = N_Compilation_Unit then Freeze_Before (N, Spec_Id); elsif Is_Access_Subprogram_Type (Etype (Body_Id)) then Freeze_Before (N, Etype (Body_Id)); end if; else Spec_Id := Corresponding_Spec (N); end if; end if; -- Do not inline any subprogram that contains nested subprograms, since -- the backend inlining circuit seems to generate uninitialized -- references in this case. We know this happens in the case of front -- end ZCX support, but it also appears it can happen in other cases as -- well. The backend often rejects attempts to inline in the case of -- nested procedures anyway, so little if anything is lost by this. -- Note that this is test is for the benefit of the back-end. There is -- a separate test for front-end inlining that also rejects nested -- subprograms. -- Do not do this test if errors have been detected, because in some -- error cases, this code blows up, and we don't need it anyway if -- there have been errors, since we won't get to the linker anyway. if Comes_From_Source (Body_Id) and then Serious_Errors_Detected = 0 then P_Ent := Body_Id; loop P_Ent := Scope (P_Ent); exit when No (P_Ent) or else P_Ent = Standard_Standard; if Is_Subprogram (P_Ent) then Set_Is_Inlined (P_Ent, False); if Comes_From_Source (P_Ent) and then Has_Pragma_Inline (P_Ent) then Cannot_Inline ("cannot inline& (nested subprogram)?", N, P_Ent); end if; end if; end loop; end if; Check_Inline_Pragma (Spec_Id); -- Deal with special case of a 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. We exclude compiler generated bodies from the -- expander since the issue does not arise for those cases. if No (Spec_Id) and then Comes_From_Source (N) and then Is_Protected_Type (Current_Scope) then Spec_Id := Build_Private_Protected_Declaration (N); end if; -- If a separate spec is present, then deal with freezing issues if 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. These freeze actions are also needed in ASIS mode to enable -- the proper back-annotations. if not Is_Frozen (Spec_Id) and then (Expander_Active or ASIS_Mode) 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); Freeze_Before (N, Spec_Id); end if; end if; -- Mark presence of postcondition procedure in current scope and mark -- the procedure itself as needing debug info. The latter is important -- when analyzing decision coverage (for example, for MC/DC coverage). if Chars (Body_Id) = Name_uPostconditions then Set_Has_Postconditions (Current_Scope); Set_Debug_Info_Needed (Body_Id); end if; -- Place subprogram on scope stack, and make formals visible. If there -- is a spec, the visible entity remains that of the spec. 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; 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_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 Prot_Typ := Scope (Spec_Id); end if; -- If this is a body generated for a renaming, do not check for -- full conformance. The check is redundant, because the spec of -- the body is a copy of the spec in the renaming declaration, -- and the test can lead to spurious errors on nested defaults. if Present (Spec_Decl) and then not Comes_From_Source (N) and then (Nkind (Original_Node (Spec_Decl)) = N_Subprogram_Renaming_Declaration or else (Present (Corresponding_Body (Spec_Decl)) and then Nkind (Unit_Declaration_Node (Corresponding_Body (Spec_Decl))) = N_Subprogram_Renaming_Declaration)) then Conformant := True; -- Conversely, the spec may have been generated for specless body -- with an inline pragma. elsif Comes_From_Source (N) and then not Comes_From_Source (Spec_Id) and then Has_Pragma_Inline (Spec_Id) then Conformant := True; else Check_Conformance (Body_Id, Spec_Id, Fully_Conformant, True, Conformant, Body_Id); end if; -- If the body is not fully conformant, we have to decide if we -- should analyze it or not. If it has a really messed up profile -- then we probably should not analyze it, since we will get too -- many bogus messages. -- Our decision is to go ahead in the non-fully conformant case -- only if it is at least mode conformant with the spec. Note -- that the call to Check_Fully_Conformant has issued the proper -- error messages to complain about the lack of conformance. if not Conformant and then not Mode_Conformant (Body_Id, Spec_Id) then return; end if; end if; if Spec_Id /= Body_Id then Reference_Body_Formals (Spec_Id, Body_Id); end if; 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 (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_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. -- Otherwise it is safe albeit redundant. Set_Is_Immediately_Visible (Spec_Id); end if; 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 else -- Check for style warning required if Style_Check -- Only apply check for source level subprograms for which checks -- have not been suppressed. and then Comes_From_Source (Body_Id) and then not Suppress_Style_Checks (Body_Id) -- No warnings within an instance and then not In_Instance -- No warnings for expression functions and then Nkind (Original_Node (N)) /= N_Expression_Function then Style.Body_With_No_Spec (N); end if; New_Overloaded_Entity (Body_Id); if Nkind (N) /= N_Subprogram_Body_Stub then Set_Acts_As_Spec (N); Generate_Definition (Body_Id); Set_Contract (Body_Id, Make_Contract (Sloc (Body_Id))); Generate_Reference (Body_Id, Body_Id, 'b', Set_Ref => False, Force => True); Install_Formals (Body_Id); Push_Scope (Body_Id); end if; -- For stubs and bodies with no previous spec, generate references to -- formals. Generate_Reference_To_Formals (Body_Id); 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_2005 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 -- only required for subprograms that come from source. if Nkind (Parent (N)) = N_Subunit and then Comes_From_Source (N) and then not Error_Posted (Body_Id) and then Nkind (Corresponding_Stub (Parent (N))) = N_Subprogram_Body_Stub then declare Old_Id : constant Entity_Id := Defining_Entity (Specification (Corresponding_Stub (Parent (N)))); Conformant : Boolean := False; begin if No (Spec_Id) then Check_Fully_Conformant (Body_Id, Old_Id); else Check_Conformance (Body_Id, Old_Id, Fully_Conformant, False, Conformant); if not Conformant then -- The stub was taken to be a new declaration. Indicate that -- it lacks a body. Set_Has_Completion (Old_Id, False); end if; end if; end; end if; Set_Has_Completion (Body_Id); Check_Eliminated (Body_Id); if Nkind (N) = N_Subprogram_Body_Stub then return; 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 Build_Body_To_Inline (N, Spec_Id); end if; -- Ada 2005 (AI-262): In library subprogram bodies, after the analysis -- of the specification we have to install the private withed units. -- This holds for child units as well. if Is_Compilation_Unit (Body_Id) 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. In formal verification -- mode, we keep pre- and postconditions attached to entities rather -- than inserted in the code, in order to facilitate a distinct -- treatment for them. if not Alfa_Mode then Process_PPCs (N, Spec_Id, Body_Id); end if; -- Add a declaration for the Protection object, 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. The -- body may be the rewritting of an expression function, and we need to -- verify that the original node is in the source. if Full_Expander_Active and then Comes_From_Source (Original_Node (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; -- Ada 2012 (AI05-0151): Incomplete types coming from a limited context -- may now appear in parameter and result profiles. Since the analysis -- of a subprogram body may use the parameter and result profile of the -- spec, swap any limited views with their non-limited counterpart. if Ada_Version >= Ada_2012 then Exchange_Limited_Views (Spec_Id); 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; Inspect_Deferred_Constant_Completion (Declarations (N)); Analyze (HSS); -- Deal with end of scope processing for the body Process_End_Label (HSS, 't', Current_Scope); End_Scope; Check_Subprogram_Order (N); Set_Analyzed (Body_Id); -- If we have a separate spec, then the analysis of the declarations -- caused the entities in the body to be chained to the spec id, but -- we want them chained to the body id. Only the formal parameters -- end up chained to the spec id in this case. if Present (Spec_Id) then -- We must conform to the categorization of our spec Validate_Categorization_Dependency (N, Spec_Id); -- And if this is a child unit, the parent units must conform if Is_Child_Unit (Spec_Id) then Validate_Categorization_Dependency (Unit_Declaration_Node (Spec_Id), Spec_Id); end if; -- 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_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); Set_Last_Entity (Spec_Id, Empty); end if; end if; Check_Missing_Return; -- Now we are going to check for variables that are never modified in -- 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: -- function F (A : Integer) return Some_Type; -- X : Some_Type; -- begin -- raise Program_Error; -- 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! 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; begin -- 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. Stm := First (Statements (HSS)); while Nkind (Stm) = N_Label or else Nkind (Stm) in N_Push_xxx_Label loop Next (Stm); end loop; -- Do the test on the original statement before expansion declare Ostm : constant Node_Id := Original_Node (Stm); begin -- If explicit raise statement, turn on flag if Nkind (Ostm) = N_Raise_Statement then Set_Trivial_Subprogram (Stm); -- If null statement, and no following statements, 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 elsif Nkind (Ostm) = N_Procedure_Call_Statement then if Is_Entity_Name (Name (Ostm)) then declare Ent : constant Entity_Id := Entity (Name (Ostm)); 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 turn on the flag. if Present (Ent) and then Ekind (Ent) = E_Procedure and then No_Return (Ent) then Set_Trivial_Subprogram (Stm); end if; end; end if; end if; end; end; -- Check for variables that are never modified declare E1, E2 : Entity_Id; begin -- If there is a separate spec, then transfer Never_Set_In_Source -- flags from out parameters to the corresponding entities in the -- body. The reason we do that is we want to post error flags on -- the body entities, not the spec entities. 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); while Present (E2) loop exit when Chars (E1) = Chars (E2); Next_Entity (E2); end loop; if Present (E2) then Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1)); end if; end if; Next_Entity (E1); end loop; end if; -- Check references in body unless it was deleted. Note that the -- check of Body_Deleted here is not just for efficiency, it is -- necessary to avoid junk warnings on formal parameters. if not Body_Deleted then Check_References (Body_Id); end if; end; end Analyze_Subprogram_Body_Helper; ------------------------------------ -- Analyze_Subprogram_Declaration -- ------------------------------------ procedure Analyze_Subprogram_Declaration (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Scop : constant Entity_Id := Current_Scope; Designator : Entity_Id; Form : Node_Id; Null_Body : Node_Id := Empty; -- Start of processing for Analyze_Subprogram_Declaration begin -- Null procedures are not allowed in SPARK if Nkind (Specification (N)) = N_Procedure_Specification and then Null_Present (Specification (N)) then Check_SPARK_Restriction ("null procedure is not allowed", N); end if; -- For a null procedure, capture the profile before analysis, for -- expansion at the freeze point and at each point of call. The body -- will only be used if the procedure has preconditions. In that case -- the body is analyzed at the freeze point. if Nkind (Specification (N)) = N_Procedure_Specification and then Null_Present (Specification (N)) and then Expander_Active then Null_Body := Make_Subprogram_Body (Loc, Specification => New_Copy_Tree (Specification (N)), Declarations => New_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List (Make_Null_Statement (Loc)))); -- Create new entities for body and formals Set_Defining_Unit_Name (Specification (Null_Body), Make_Defining_Identifier (Loc, Chars (Defining_Entity (N)))); Form := First (Parameter_Specifications (Specification (Null_Body))); while Present (Form) loop Set_Defining_Identifier (Form, Make_Defining_Identifier (Loc, Chars (Defining_Identifier (Form)))); -- Resolve the types of the formals now, because the freeze point -- may appear in a different context, e.g. an instantiation. if Nkind (Parameter_Type (Form)) /= N_Access_Definition then Find_Type (Parameter_Type (Form)); elsif No (Access_To_Subprogram_Definition (Parameter_Type (Form))) then Find_Type (Subtype_Mark (Parameter_Type (Form))); else -- the case of a null procedure with a formal that is an -- access_to_subprogram type, and that is used as an actual -- in an instantiation is left to the enthusiastic reader. null; end if; Next (Form); end loop; if Is_Protected_Type (Current_Scope) then Error_Msg_N ("protected operation cannot be a null procedure", N); end if; end if; Designator := Analyze_Subprogram_Specification (Specification (N)); -- A reference may already have been generated for the unit name, in -- which case the following call is redundant. However it is needed for -- declarations that are the rewriting of an expression function. Generate_Definition (Designator); if Debug_Flag_C then Write_Str ("==> subprogram spec "); Write_Name (Chars (Designator)); Write_Str (" from "); Write_Location (Sloc (N)); Write_Eol; Indent; end if; if Nkind (Specification (N)) = N_Procedure_Specification and then Null_Present (Specification (N)) then Set_Has_Completion (Designator); -- Null procedures are always inlined, but generic formal subprograms -- which appear as such in the internal instance of formal packages, -- need no completion and are not marked Inline. if Present (Null_Body) and then Nkind (N) /= N_Formal_Concrete_Subprogram_Declaration then Set_Corresponding_Body (N, Defining_Entity (Null_Body)); Set_Body_To_Inline (N, Null_Body); Set_Is_Inlined (Designator); end if; end if; Validate_RCI_Subprogram_Declaration (N); New_Overloaded_Entity (Designator); Check_Delayed_Subprogram (Designator); -- If the type of the first formal of the current subprogram is a -- nongeneric tagged private type, mark the subprogram as being a -- private primitive. Ditto if this is a function with controlling -- result, and the return type is currently private. In both cases, -- the type of the controlling argument or result must be in the -- current scope for the operation to be primitive. if Has_Controlling_Result (Designator) and then Is_Private_Type (Etype (Designator)) and then Scope (Etype (Designator)) = Current_Scope and then not Is_Generic_Actual_Type (Etype (Designator)) then Set_Is_Private_Primitive (Designator); elsif Present (First_Formal (Designator)) then declare Formal_Typ : constant Entity_Id := Etype (First_Formal (Designator)); begin Set_Is_Private_Primitive (Designator, Is_Tagged_Type (Formal_Typ) and then Scope (Formal_Typ) = Current_Scope and then Is_Private_Type (Formal_Typ) and then not Is_Generic_Actual_Type (Formal_Typ)); end; end if; -- Ada 2005 (AI-251): Abstract interface primitives must be abstract -- or null. if Ada_Version >= Ada_2005 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)); -- Specialize error message based on procedures vs. functions, -- since functions can't be null subprograms. if Ekind (Designator) = E_Procedure then Error_Msg_N ("interface procedure % must be abstract or null", N); else Error_Msg_N ("interface function % must be abstract", N); end if; end if; end; end if; -- What is the following code for, it used to be -- ??? Set_Suppress_Elaboration_Checks -- ??? (Designator, Elaboration_Checks_Suppressed (Designator)); -- The following seems equivalent, but a bit dubious if Elaboration_Checks_Suppressed (Designator) then Set_Kill_Elaboration_Checks (Designator); end if; if Scop /= Standard_Standard and then not Is_Child_Unit (Designator) then Set_Categorization_From_Scope (Designator, Scop); else -- For a compilation unit, check for library-unit pragmas Push_Scope (Designator); Set_Categorization_From_Pragmas (N); Validate_Categorization_Dependency (N, Designator); Pop_Scope; end if; -- For a compilation unit, set body required. This flag will only be -- reset if a valid Import or Interface pragma is processed later on. if Nkind (Parent (N)) = N_Compilation_Unit then Set_Body_Required (Parent (N), True); if Ada_Version >= Ada_2005 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 Debug_Flag_C then Outdent; Write_Str ("<== subprogram spec "); Write_Name (Chars (Designator)); Write_Str (" from "); Write_Location (Sloc (N)); Write_Eol; end if; if Is_Protected_Type (Current_Scope) then -- Indicate that this is a protected operation, because it may be -- used in subsequent declarations within the protected type. Set_Convention (Designator, Convention_Protected); end if; List_Inherited_Pre_Post_Aspects (Designator); if Has_Aspects (N) then Analyze_Aspect_Specifications (N, Designator); end if; end Analyze_Subprogram_Declaration; -------------------------------------- -- Analyze_Subprogram_Specification -- -------------------------------------- -- Reminder: N here really is a subprogram specification (not a subprogram -- declaration). This procedure is called to analyze the specification in -- both subprogram bodies and subprogram declarations (specs). 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); -- Start of processing for Analyze_Subprogram_Specification begin -- User-defined operator is not allowed in SPARK, except as a renaming if Nkind (Defining_Unit_Name (N)) = N_Defining_Operator_Symbol and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration then Check_SPARK_Restriction ("user-defined operator is not allowed", N); end if; -- Proceed with analysis. Do not emit a cross-reference entry if the -- specification comes from an expression function, because it may be -- the completion of a previous declaration. It is is not, the cross- -- reference entry will be emitted for the new subprogram declaration. if Nkind (Parent (N)) /= N_Expression_Function then Generate_Definition (Designator); end if; Set_Contract (Designator, Make_Contract (Sloc (Designator))); if Nkind (N) = N_Function_Specification then Set_Ekind (Designator, E_Function); Set_Mechanism (Designator, Default_Mechanism); else Set_Ekind (Designator, E_Procedure); Set_Etype (Designator, Standard_Void_Type); end if; -- Introduce new scope for analysis of the formals and the return type Set_Scope (Designator, Current_Scope); if Present (Formals) then Push_Scope (Designator); Process_Formals (Formals, N); -- Ada 2005 (AI-345): If this is an overriding operation of an -- inherited interface operation, and the controlling type is -- a synchronized type, replace the type with its corresponding -- record, to match the proper signature of an overriding operation. -- Same processing for an access parameter whose designated type is -- derived from a synchronized interface. if Ada_Version >= Ada_2005 then declare Formal : Entity_Id; Formal_Typ : Entity_Id; Rec_Typ : Entity_Id; Desig_Typ : Entity_Id; begin Formal := First_Formal (Designator); while Present (Formal) loop Formal_Typ := Etype (Formal); if Is_Concurrent_Type (Formal_Typ) and then Present (Corresponding_Record_Type (Formal_Typ)) then Rec_Typ := Corresponding_Record_Type (Formal_Typ); if Present (Interfaces (Rec_Typ)) then Set_Etype (Formal, Rec_Typ); end if; elsif Ekind (Formal_Typ) = E_Anonymous_Access_Type then Desig_Typ := Designated_Type (Formal_Typ); if Is_Concurrent_Type (Desig_Typ) and then Present (Corresponding_Record_Type (Desig_Typ)) then Rec_Typ := Corresponding_Record_Type (Desig_Typ); if Present (Interfaces (Rec_Typ)) then Set_Directly_Designated_Type (Formal_Typ, Rec_Typ); end if; end if; end if; Next_Formal (Formal); end loop; end; end if; End_Scope; -- The subprogram scope is pushed and popped around the processing of -- the return type for consistency with call above to Process_Formals -- (which itself can call Analyze_Return_Type), and to ensure that any -- itype created for the return type will be associated with the proper -- scope. elsif Nkind (N) = N_Function_Specification then Push_Scope (Designator); Analyze_Return_Type (N); End_Scope; end if; -- Function case if Nkind (N) = N_Function_Specification then -- Deal with operator symbol case if Nkind (Designator) = N_Defining_Operator_Symbol then Valid_Operator_Definition (Designator); end if; May_Need_Actuals (Designator); -- Ada 2005 (AI-251): If the return type is abstract, verify that -- the subprogram is abstract also. This does not apply to renaming -- declarations, where abstractness is inherited, and to subprogram -- bodies generated for stream operations, which become renamings as -- bodies. -- In case of primitives associated with abstract interface types -- the check is applied later (see Analyze_Subprogram_Declaration). if not Nkind_In (Original_Node (Parent (N)), N_Subprogram_Renaming_Declaration, N_Abstract_Subprogram_Declaration, N_Formal_Abstract_Subprogram_Declaration) then if Is_Abstract_Type (Etype (Designator)) and then not Is_Interface (Etype (Designator)) then Error_Msg_N ("function that returns abstract type must be abstract", N); -- Ada 2012 (AI-0073): Extend this test to subprograms with an -- access result whose designated type is abstract. elsif Nkind (Result_Definition (N)) = N_Access_Definition and then not Is_Class_Wide_Type (Designated_Type (Etype (Designator))) and then Is_Abstract_Type (Designated_Type (Etype (Designator))) and then Ada_Version >= Ada_2012 then Error_Msg_N ("function whose access result designates " & "abstract type must be abstract", N); end if; end if; end if; return Designator; end Analyze_Subprogram_Specification; -------------------------- -- Build_Body_To_Inline -- -------------------------- procedure Build_Body_To_Inline (N : Node_Id; Subp : Entity_Id) is Decl : constant Node_Id := Unit_Declaration_Node (Subp); Original_Body : Node_Id; Body_To_Analyze : Node_Id; Max_Size : constant := 10; Stat_Count : Integer := 0; function Has_Excluded_Declaration (Decls : List_Id) return Boolean; -- Check for declarations that make inlining not worthwhile function Has_Excluded_Statement (Stats : List_Id) return Boolean; -- Check for statements that make inlining not worthwhile: any tasking -- statement, nested at any level. Keep track of total number of -- 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 -- 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 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 -- unconstrained type, the secondary stack is involved, and it -- is not worth inlining. ------------------------------ -- Has_Excluded_Declaration -- ------------------------------ function Has_Excluded_Declaration (Decls : List_Id) return Boolean is D : Node_Id; function Is_Unchecked_Conversion (D : Node_Id) return Boolean; -- Nested subprograms make a given body ineligible for inlining, but -- we make an exception for instantiations of unchecked conversion. -- The body has not been analyzed yet, so check the name, and verify -- that the visible entity with that name is the predefined unit. ----------------------------- -- Is_Unchecked_Conversion -- ----------------------------- function Is_Unchecked_Conversion (D : Node_Id) return Boolean is Id : constant Node_Id := Name (D); Conv : Entity_Id; begin if Nkind (Id) = N_Identifier and then Chars (Id) = Name_Unchecked_Conversion then Conv := Current_Entity (Id); 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 Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Conv))) and then Is_Intrinsic_Subprogram (Conv); end Is_Unchecked_Conversion; -- Start of processing for Has_Excluded_Declaration begin D := First (Decls); while Present (D) loop 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); return True; end if; Next (D); end loop; return False; end Has_Excluded_Declaration; ---------------------------- -- Has_Excluded_Statement -- ---------------------------- function Has_Excluded_Statement (Stats : List_Id) return Boolean is S : Node_Id; E : Node_Id; begin S := First (Stats); while Present (S) loop Stat_Count := Stat_Count + 1; 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); return True; elsif Nkind (S) = N_Block_Statement then if Present (Declarations (S)) and then Has_Excluded_Declaration (Declarations (S)) then return True; elsif Present (Handled_Statement_Sequence (S)) and then (Present (Exception_Handlers (Handled_Statement_Sequence (S))) or else Has_Excluded_Statement (Statements (Handled_Statement_Sequence (S)))) then return True; end if; elsif Nkind (S) = N_Case_Statement then E := First (Alternatives (S)); while Present (E) loop if Has_Excluded_Statement (Statements (E)) then return True; end if; Next (E); end loop; elsif Nkind (S) = N_If_Statement then if Has_Excluded_Statement (Then_Statements (S)) then return True; end if; if Present (Elsif_Parts (S)) then E := First (Elsif_Parts (S)); while Present (E) loop if Has_Excluded_Statement (Then_Statements (E)) then return True; end if; Next (E); end loop; end if; if Present (Else_Statements (S)) and then Has_Excluded_Statement (Else_Statements (S)) then return True; end if; elsif Nkind (S) = N_Loop_Statement and then Has_Excluded_Statement (Statements (S)) then return True; elsif Nkind (S) = N_Extended_Return_Statement then if Has_Excluded_Statement (Statements (Handled_Statement_Sequence (S))) or else Present (Exception_Handlers (Handled_Statement_Sequence (S))) then return True; end if; end if; Next (S); end loop; return False; end Has_Excluded_Statement; ------------------------------- -- Has_Pending_Instantiation -- ------------------------------- function Has_Pending_Instantiation return Boolean is S : Entity_Id; begin S := Current_Scope; while Present (S) loop if Is_Compilation_Unit (S) or else Is_Child_Unit (S) then return False; elsif Ekind (S) = E_Package and then Has_Forward_Instantiation (S) then return True; end if; S := Scope (S); end loop; 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; -- A return statement within an extended return is a noop -- after inlining. elsif No (Expression (N)) and then Nkind (Parent (Parent (N))) = N_Extended_Return_Statement then return OK; else -- Expression has wrong form return Abandon; end if; -- We can only inline a build-in-place function if -- it has a single extended return. elsif Nkind (N) = N_Extended_Return_Statement then if No (Return_Statement) then Return_Statement := N; return OK; else 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 if Check_All_Returns (N) /= OK then return False; elsif Nkind (Return_Statement) = N_Extended_Return_Statement then return True; else return Present (Declarations (N)) and then Present (First (Declarations (N))) and then Chars (Expression (Return_Statement)) = Chars (Defining_Identifier (First (Declarations (N)))); end if; end Has_Single_Return; -------------------- -- Remove_Pragmas -- -------------------- procedure Remove_Pragmas is Decl : Node_Id; Nxt : Node_Id; begin Decl := First (Declarations (Body_To_Analyze)); while Present (Decl) loop Nxt := Next (Decl); if Nkind (Decl) = N_Pragma and then (Pragma_Name (Decl) = Name_Unreferenced or else Pragma_Name (Decl) = Name_Unmodified) then Remove (Decl); end if; Decl := Nxt; end loop; end Remove_Pragmas; -------------------------- -- Uses_Secondary_Stack -- -------------------------- function Uses_Secondary_Stack (Bod : Node_Id) return Boolean is function Check_Call (N : Node_Id) return Traverse_Result; -- Look for function calls that return an unconstrained type ---------------- -- Check_Call -- ---------------- function Check_Call (N : Node_Id) return Traverse_Result is begin if Nkind (N) = N_Function_Call and then Is_Entity_Name (Name (N)) and then Is_Composite_Type (Etype (Entity (Name (N)))) and then not Is_Constrained (Etype (Entity (Name (N)))) then Cannot_Inline ("cannot inline & (call returns unconstrained type)?", N, Subp); return Abandon; else return OK; end if; end Check_Call; function Check_Calls is new Traverse_Func (Check_Call); begin return Check_Calls (Bod) = Abandon; end Uses_Secondary_Stack; -- Start of processing for Build_Body_To_Inline begin -- Return immediately if done already if Nkind (Decl) = N_Subprogram_Declaration and then Present (Body_To_Inline (Decl)) then return; -- 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 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 Needs_Finalization (Etype (Subp)) then Cannot_Inline ("cannot inline & (controlled return type)?", N, Subp); return; end if; if Present (Declarations (N)) and then Has_Excluded_Declaration (Declarations (N)) then return; end if; if Present (Handled_Statement_Sequence (N)) then if Present (Exception_Handlers (Handled_Statement_Sequence (N))) then Cannot_Inline ("cannot inline& (exception handler)?", First (Exception_Handlers (Handled_Statement_Sequence (N))), Subp); return; elsif Has_Excluded_Statement (Statements (Handled_Statement_Sequence (N))) then return; end if; end if; -- We do not inline a subprogram that is too large, unless it is -- marked Inline_Always. This pragma does not suppress the other -- checks on inlining (forbidden declarations, handlers, etc). if Stat_Count > Max_Size and then not Has_Pragma_Inline_Always (Subp) then Cannot_Inline ("cannot inline& (body too large)?", N, Subp); return; end if; if Has_Pending_Instantiation then Cannot_Inline ("cannot inline& (forward instance within enclosing body)?", N, Subp); return; end if; -- Within an instance, the body to inline must be treated as a nested -- generic, so that the proper global references are preserved. -- 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 Original_Body := Copy_Separate_Tree (N); end if; -- We need to capture references to the formals in order to substitute -- the actuals at the point of inlining, i.e. instantiation. To treat -- the formals as globals to the body to inline, we nest it within -- a dummy parameterless subprogram, declared within the real one. -- To avoid generating an internal name (which is never public, and -- which affects serial numbers of other generated names), we use -- an internal symbol that cannot conflict with user declarations. Set_Parameter_Specifications (Specification (Original_Body), No_List); Set_Defining_Unit_Name (Specification (Original_Body), Make_Defining_Identifier (Sloc (N), Name_uParent)); Set_Corresponding_Spec (Original_Body, Empty); Body_To_Analyze := Copy_Generic_Node (Original_Body, Empty, False); -- Set return type of function, which is also global and does not need -- to be resolved. if Ekind (Subp) = E_Function then Set_Result_Definition (Specification (Body_To_Analyze), New_Occurrence_Of (Etype (Subp), Sloc (N))); end if; if No (Declarations (N)) then Set_Declarations (N, New_List (Body_To_Analyze)); else Append (Body_To_Analyze, Declarations (N)); end if; Expander_Mode_Save_And_Set (False); Remove_Pragmas; Analyze (Body_To_Analyze); Push_Scope (Defining_Entity (Body_To_Analyze)); Save_Global_References (Original_Body); End_Scope; Remove (Body_To_Analyze); Expander_Mode_Restore; -- Restore environment if previously saved if In_Instance and then Scope (Current_Scope) /= Standard_Standard then Restore_Env; end if; -- If secondary stk used there is no point in inlining. We have -- already issued the warning in this case, so nothing to do. if Uses_Secondary_Stack (Body_To_Analyze) then return; end if; Set_Body_To_Inline (Decl, Original_Body); Set_Ekind (Defining_Entity (Original_Body), Ekind (Subp)); Set_Is_Inlined (Subp); end Build_Body_To_Inline; ------------------- -- Cannot_Inline -- ------------------- procedure Cannot_Inline (Msg : String; N : Node_Id; Subp : Entity_Id) is begin -- Do not emit warning if this is a predefined unit which is not the -- main unit. With validity checks enabled, some predefined subprograms -- may contain nested subprograms and become ineligible for inlining. if Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Subp))) and then not In_Extended_Main_Source_Unit (Subp) then null; 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 (Msg'First .. Msg'Last - 1), N, Subp); elsif Ineffective_Inline_Warnings then Error_Msg_NE (Msg, N, Subp); end if; end Cannot_Inline; ----------------------- -- Check_Conformance -- ----------------------- 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; Skip_Controlling_Formals : Boolean := False) is procedure Conformance_Error (Msg : String; N : Node_Id := New_Id); -- Sets Conforms to False. If Errmsg is False, then that's all it does. -- If Errmsg is True, then processing continues to post an error message -- for conformance error on given node. Two messages are output. The -- first message points to the previous declaration with a general "no -- conformance" message. The second is the detailed reason, supplied as -- Msg. The parameter N provide information for a possible & insertion -- in the message, and also provides the location for posting the -- message in the absence of a specified Err_Loc location. ----------------------- -- Conformance_Error -- ----------------------- procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is Enode : Node_Id; begin Conforms := False; if Errmsg then if No (Err_Loc) then Enode := N; else Enode := Err_Loc; end if; Error_Msg_Sloc := Sloc (Old_Id); case Ctype is when Type_Conformant => Error_Msg_N -- CODEFIX ("not type conformant with declaration#!", Enode); when Mode_Conformant => 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 => 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 => if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then Error_Msg_N -- CODEFIX ("not fully conformant with operation inherited#!", Enode); else Error_Msg_N -- CODEFIX ("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 Conforms := True; -- We need a special case for operators, since they don't appear -- explicitly. if Ctype = Type_Conformant then if Ekind (New_Id) = E_Operator and then Operator_Matches_Spec (New_Id, Old_Id) then return; end if; end if; -- If both are functions/operators, check return types conform if Old_Type /= Standard_Void_Type and then New_Type /= Standard_Void_Type then -- If we are checking interface conformance we omit controlling -- arguments and result, because we are only checking the conformance -- of the remaining parameters. if Has_Controlling_Result (Old_Id) and then Has_Controlling_Result (New_Id) and then Skip_Controlling_Formals then null; elsif not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then 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_2005 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; -- If either is a function/operator and the other isn't, error elsif Old_Type /= Standard_Void_Type or else New_Type /= Standard_Void_Type then Conformance_Error ("\functions can only match functions!", New_Id); return; end if; -- 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 -- entity is inherited. if Ctype >= Subtype_Conformant then if Convention (Old_Id) /= Convention (New_Id) then if not Is_Frozen (New_Id) then null; elsif Present (Err_Loc) and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration and then Present (Corresponding_Spec (Err_Loc)) then Error_Msg_Name_1 := Chars (New_Id); Error_Msg_Name_2 := Name_Ada + Convention_Id'Pos (Convention (New_Id)); Conformance_Error ("\prior declaration for% has convention %!"); else Conformance_Error ("\calling conventions do not match!"); end if; return; elsif Is_Formal_Subprogram (Old_Id) or else Is_Formal_Subprogram (New_Id) then Conformance_Error ("\formal subprograms not allowed!"); return; end if; end if; -- Deal with parameters -- Note: we use the entity information, rather than going directly -- to the specification in the tree. This is not only simpler, but -- absolutely necessary for some cases of conformance tests between -- operators, where the declaration tree simply does not exist! Old_Formal := First_Formal (Old_Id); 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 -- The controlling formals will have different types when -- comparing an interface operation with its match, but both -- or neither must be access parameters. if Is_Access_Type (Etype (Old_Formal)) = Is_Access_Type (Etype (New_Formal)) then goto Skip_Controlling_Formal; else Conformance_Error ("\access parameter does not match!", New_Formal); end if; 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); -- Set error posted flag on new formal as well to stop -- junk cascaded messages in some cases. Set_Error_Posted (New_Formal); return; end if; -- Null exclusion must match if Null_Exclusion_Present (Parent (Old_Formal)) /= Null_Exclusion_Present (Parent (New_Formal)) then -- Only give error if both come from source. This should be -- investigated some time, since it should not be needed ??? if Comes_From_Source (Old_Formal) and then Comes_From_Source (New_Formal) then Conformance_Error ("\null exclusion for & does not match", New_Formal); -- Mark error posted on the new formal to avoid duplicated -- complaint about types not matching. Set_Error_Posted (New_Formal); end if; 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_2005 -- 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). if In_Instance_Visible_Part and then Is_Dispatching_Operation (New_Id) then if not Conforming_Types (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); return; end if; elsif not Conforming_Types (T1 => Old_Formal_Base, T2 => New_Formal_Base, Ctype => Ctype, Get_Inst => Get_Inst) and then not Access_Types_Match then -- Don't give error message if old type is Any_Type. This test -- avoids some cascaded errors, e.g. in case of a bad spec. if Errmsg and then Old_Formal_Base = Any_Type then Conforms := False; else Conformance_Error ("\type of & does not match!", New_Formal); end if; return; end if; -- For mode conformance, mode must match if Ctype >= Mode_Conformant then if Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal) then if not Ekind_In (New_Id, E_Function, E_Procedure) or else not Is_Primitive_Wrapper (New_Id) then Conformance_Error ("\mode of & does not match!", New_Formal); else declare T : constant Entity_Id := Find_Dispatching_Type (New_Id); begin if Is_Protected_Type (Corresponding_Concurrent_Type (T)) then Error_Msg_PT (T, New_Id); else Conformance_Error ("\mode of & does not match!", New_Formal); end if; end; end if; 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. For null exclusion, we test the types rather than the -- formals themselves, since the attribute is only set reliably -- on the formals in the Ada 95 case, and we exclude the case -- where Old_Formal is marked as controlling, to avoid errors -- when matching completing bodies with dispatching declarations -- (access formals in the bodies aren't marked Can_Never_Be_Null). if Ada_Version >= Ada_2005 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 (Etype (Old_Formal)) /= Can_Never_Be_Null (Etype (New_Formal)) and then not Is_Controlling_Formal (Old_Formal)) or else Is_Access_Constant (Etype (Old_Formal)) /= Is_Access_Constant (Etype (New_Formal))) -- Do not complain if error already posted on New_Formal. This -- avoids some redundant error messages. and then not Error_Posted (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 if Parameter_Mode (Old_Formal) = E_In_Parameter then -- Check default expressions for in parameters declare NewD : constant Boolean := Present (Default_Value (New_Formal)); OldD : constant Boolean := Present (Default_Value (Old_Formal)); begin if NewD or OldD then -- The old default value has been analyzed because the -- current full declaration will have frozen everything -- before. The new default value has not been analyzed, -- so analyze it now before we check for conformance. if NewD then Push_Scope (New_Id); Preanalyze_Spec_Expression (Default_Value (New_Formal), Etype (New_Formal)); End_Scope; end if; if not (NewD and OldD) or else not Fully_Conformant_Expressions (Default_Value (Old_Formal), Default_Value (New_Formal)) then Conformance_Error ("\default expression for & does not match!", New_Formal); return; end if; end if; end; end if; end if; -- A couple of special checks for Ada 83 mode. These checks are -- 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 and then Sloc (Old_Id) > Standard_Location and then Sloc (New_Id) > Standard_Location and then Comes_From_Source (Old_Id) and then Comes_From_Source (New_Id) then declare Old_Param : constant Node_Id := Declaration_Node (Old_Formal); New_Param : constant Node_Id := Declaration_Node (New_Formal); begin -- Explicit IN must be present or absent in both cases. This -- test is required only in the full conformance case. if In_Present (Old_Param) /= In_Present (New_Param) and then Ctype = Fully_Conformant then Conformance_Error ("\(Ada 83) IN must appear in both declarations", New_Formal); return; end if; -- Grouping (use of comma in param lists) must be the same -- This is where we catch a misconformance like: -- A, B : Integer -- A : Integer; B : Integer -- which are represented identically in the tree except -- for the setting of the flags More_Ids and Prev_Ids. if More_Ids (Old_Param) /= More_Ids (New_Param) or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param) then Conformance_Error ("\grouping of & does not match!", New_Formal); return; end if; end; end if; -- This label is required when skipping controlling formals <<Skip_Controlling_Formal>> 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 Ifaces_List : Elist_Id; procedure Check_Convention (Op : Entity_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) is Iface_Elmt : Elmt_Id; Iface_Prim_Elmt : Elmt_Id; Iface_Prim : Entity_Id; begin Iface_Elmt := First_Elmt (Ifaces_List); while Present (Iface_Elmt) loop Iface_Prim_Elmt := First_Elmt (Primitive_Operations (Node (Iface_Elmt))); while Present (Iface_Prim_Elmt) loop Iface_Prim := Node (Iface_Prim_Elmt); if Is_Interface_Conformant (Typ, Iface_Prim, Op) and then Convention (Iface_Prim) /= Convention (Op) then Error_Msg_N ("inconsistent conventions in primitive operations", Typ); Error_Msg_Name_1 := Chars (Op); Error_Msg_Name_2 := Get_Convention_Name (Convention (Op)); Error_Msg_Sloc := Sloc (Op); if Comes_From_Source (Op) or else No (Alias (Op)) then if not Present (Overridden_Operation (Op)) then Error_Msg_N ("\\primitive % defined #", Typ); else Error_Msg_N ("\\overriding operation % with " & "convention % defined #", Typ); end if; else pragma Assert (Present (Alias (Op))); Error_Msg_Sloc := Sloc (Alias (Op)); Error_Msg_N ("\\inherited operation % with " & "convention % defined #", Typ); end if; Error_Msg_Name_1 := Chars (Op); Error_Msg_Name_2 := Get_Convention_Name (Convention (Iface_Prim)); Error_Msg_Sloc := Sloc (Iface_Prim); Error_Msg_N ("\\overridden operation % with " & "convention % defined #", Typ); -- Avoid cascading errors return; end if; Next_Elmt (Iface_Prim_Elmt); end loop; Next_Elmt (Iface_Elmt); end loop; end Check_Convention; -- Local variables Prim_Op : Entity_Id; Prim_Op_Elmt : Elmt_Id; -- Start of processing for Check_Conventions begin if not Has_Interfaces (Typ) then return; end if; Collect_Interfaces (Typ, Ifaces_List); -- The algorithm checks every overriding dispatching operation against -- all the corresponding overridden dispatching operations, detecting -- differences in conventions. 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. if not Is_Predefined_Dispatching_Operation (Prim_Op) then Check_Convention (Prim_Op); end if; Next_Elmt (Prim_Op_Elmt); end loop; end Check_Conventions; ------------------------------ -- Check_Delayed_Subprogram -- ------------------------------ procedure Check_Delayed_Subprogram (Designator : Entity_Id) is F : Entity_Id; procedure Possible_Freeze (T : Entity_Id); -- T is the type of either a formal parameter or of the return type. -- If T is not yet frozen and needs a delayed freeze, then the -- subprogram itself must be delayed. If T is the limited view of an -- incomplete type the subprogram must be frozen as well, because -- T may depend on local types that have not been frozen yet. --------------------- -- Possible_Freeze -- --------------------- procedure Possible_Freeze (T : Entity_Id) is begin if Has_Delayed_Freeze (T) and then not Is_Frozen (T) then Set_Has_Delayed_Freeze (Designator); elsif Is_Access_Type (T) and then Has_Delayed_Freeze (Designated_Type (T)) and then not Is_Frozen (Designated_Type (T)) then Set_Has_Delayed_Freeze (Designator); elsif Ekind (T) = E_Incomplete_Type and then From_With_Type (T) then Set_Has_Delayed_Freeze (Designator); -- AI05-0151: In Ada 2012, Incomplete types can appear in the profile -- of a subprogram or entry declaration. elsif Ekind (T) = E_Incomplete_Type and then Ada_Version >= Ada_2012 then Set_Has_Delayed_Freeze (Designator); end if; end Possible_Freeze; -- Start of processing for Check_Delayed_Subprogram begin -- All subprograms, including abstract subprograms, may need a freeze -- node if some formal type or the return type needs one. Possible_Freeze (Etype (Designator)); Possible_Freeze (Base_Type (Etype (Designator))); -- needed ??? -- Need delayed freeze if any of the formal types themselves need -- a delayed freeze and are not yet frozen. F := First_Formal (Designator); while Present (F) loop Possible_Freeze (Etype (F)); Possible_Freeze (Base_Type (Etype (F))); -- needed ??? Next_Formal (F); end loop; -- Mark functions that return by reference. Note that it cannot be -- done for delayed_freeze subprograms because the underlying -- returned type may not be known yet (for private types) if not Has_Delayed_Freeze (Designator) and then Expander_Active then declare Typ : constant Entity_Id := Etype (Designator); Utyp : constant Entity_Id := Underlying_Type (Typ); begin if Is_Immutably_Limited_Type (Typ) then Set_Returns_By_Ref (Designator); elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then Set_Returns_By_Ref (Designator); end if; end; end if; end Check_Delayed_Subprogram; ------------------------------------ -- Check_Discriminant_Conformance -- ------------------------------------ procedure Check_Discriminant_Conformance (N : Node_Id; Prev : Entity_Id; Prev_Loc : Node_Id) is Old_Discr : Entity_Id := First_Discriminant (Prev); New_Discr : Node_Id := First (Discriminant_Specifications (N)); New_Discr_Id : Entity_Id; New_Discr_Type : Entity_Id; procedure Conformance_Error (Msg : String; N : Node_Id); -- Post error message for conformance error on given node. Two messages -- are output. The first points to the previous declaration with a -- general "no conformance" message. The second is the detailed reason, -- supplied as Msg. The parameter N provide information for a possible -- & insertion in the message. ----------------------- -- Conformance_Error -- ----------------------- procedure Conformance_Error (Msg : String; N : Node_Id) is begin Error_Msg_Sloc := Sloc (Prev_Loc); Error_Msg_N -- CODEFIX ("not fully conformant with declaration#!", N); Error_Msg_NE (Msg, N, N); end Conformance_Error; -- Start of processing for Check_Discriminant_Conformance begin while Present (Old_Discr) and then Present (New_Discr) loop New_Discr_Id := Defining_Identifier (New_Discr); -- The subtype mark of the discriminant on the full type has not -- been analyzed so we do it here. For an access discriminant a new -- type is created. if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then New_Discr_Type := Access_Definition (N, Discriminant_Type (New_Discr)); else Analyze (Discriminant_Type (New_Discr)); New_Discr_Type := Etype (Discriminant_Type (New_Discr)); -- Ada 2005: if the discriminant definition carries a null -- exclusion, create an itype to check properly for consistency -- with partial declaration. if Is_Access_Type (New_Discr_Type) and then Null_Exclusion_Present (New_Discr) then New_Discr_Type := Create_Null_Excluding_Itype (T => New_Discr_Type, Related_Nod => New_Discr, Scope_Id => Current_Scope); end if; end if; if not Conforming_Types (Etype (Old_Discr), New_Discr_Type, Fully_Conformant) then Conformance_Error ("type of & does not match!", New_Discr_Id); return; else -- Treat the new discriminant as an occurrence of the old one, -- for navigation purposes, and fill in some semantic -- information, for completeness. Generate_Reference (Old_Discr, New_Discr_Id, 'r'); Set_Etype (New_Discr_Id, Etype (Old_Discr)); Set_Scope (New_Discr_Id, Scope (Old_Discr)); end if; -- Names must match if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then Conformance_Error ("name & does not match!", New_Discr_Id); return; end if; -- Default expressions must match declare NewD : constant Boolean := Present (Expression (New_Discr)); OldD : constant Boolean := Present (Expression (Parent (Old_Discr))); begin if NewD or OldD then -- The old default value has been analyzed and expanded, -- because the current full declaration will have frozen -- everything before. The new default values have not been -- expanded, so expand now to check conformance. if NewD then Preanalyze_Spec_Expression (Expression (New_Discr), New_Discr_Type); end if; if not (NewD and OldD) or else not Fully_Conformant_Expressions (Expression (Parent (Old_Discr)), Expression (New_Discr)) then Conformance_Error ("default expression for & does not match!", New_Discr_Id); return; end if; end if; end; -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X) if Ada_Version = Ada_83 then declare Old_Disc : constant Node_Id := Declaration_Node (Old_Discr); begin -- Grouping (use of comma in param lists) must be the same -- This is where we catch a misconformance like: -- A, B : Integer -- A : Integer; B : Integer -- which are represented identically in the tree except -- for the setting of the flags More_Ids and Prev_Ids. if More_Ids (Old_Disc) /= More_Ids (New_Discr) or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr) then Conformance_Error ("grouping of & does not match!", New_Discr_Id); return; end if; end; end if; Next_Discriminant (Old_Discr); Next (New_Discr); end loop; if Present (Old_Discr) then Conformance_Error ("too few discriminants!", Defining_Identifier (N)); return; elsif Present (New_Discr) then Conformance_Error ("too many discriminants!", Defining_Identifier (New_Discr)); return; end if; end Check_Discriminant_Conformance; ---------------------------- -- Check_Fully_Conformant -- ---------------------------- procedure Check_Fully_Conformant (New_Id : Entity_Id; Old_Id : Entity_Id; 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); end Check_Fully_Conformant; --------------------------- -- Check_Mode_Conformant -- --------------------------- procedure Check_Mode_Conformant (New_Id : Entity_Id; Old_Id : Entity_Id; Err_Loc : Node_Id := Empty; 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_Indicator -- -------------------------------- procedure Check_Overriding_Indicator (Subp : Entity_Id; Overridden_Subp : Entity_Id; Is_Primitive : Boolean) is Decl : Node_Id; Spec : Node_Id; begin -- No overriding indicator for literals if Ekind (Subp) = E_Enumeration_Literal then return; elsif Ekind (Subp) = E_Entry then Decl := Parent (Subp); -- No point in analyzing a malformed operator elsif Nkind (Subp) = N_Defining_Operator_Symbol and then Error_Posted (Subp) then return; else Decl := Unit_Declaration_Node (Subp); end if; 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); elsif Nkind (Decl) = N_Entry_Declaration then Spec := Decl; else return; end if; -- The overriding operation is type conformant with the overridden one, -- but the names of the formals are not required to match. If the names -- appear permuted in the overriding operation, this is a possible -- source of confusion that is worth diagnosing. Controlling formals -- often carry names that reflect the type, and it is not worthwhile -- requiring that their names match. if Present (Overridden_Subp) and then Nkind (Subp) /= N_Defining_Operator_Symbol then declare Form1 : Entity_Id; Form2 : Entity_Id; begin Form1 := First_Formal (Subp); Form2 := First_Formal (Overridden_Subp); -- If the overriding operation is a synchronized operation, skip -- the first parameter of the overridden operation, which is -- implicit in the new one. If the operation is declared in the -- body it is not primitive and all formals must match. if Is_Concurrent_Type (Scope (Subp)) and then Is_Tagged_Type (Scope (Subp)) and then not Has_Completion (Scope (Subp)) then Form2 := Next_Formal (Form2); end if; if Present (Form1) then Form1 := Next_Formal (Form1); Form2 := Next_Formal (Form2); end if; while Present (Form1) loop if not Is_Controlling_Formal (Form1) and then Present (Next_Formal (Form2)) and then Chars (Form1) = Chars (Next_Formal (Form2)) then Error_Msg_Node_2 := Alias (Overridden_Subp); Error_Msg_Sloc := Sloc (Error_Msg_Node_2); Error_Msg_NE ("& does not match corresponding formal of&#", Form1, Form1); exit; end if; Next_Formal (Form1); Next_Formal (Form2); end loop; end; end if; -- If there is an overridden subprogram, then check that there is no -- "not overriding" indicator, and mark the subprogram as overriding. -- This is not done if the overridden subprogram is marked as hidden, -- which can occur for the case of inherited controlled operations -- (see Derive_Subprogram), unless the inherited subprogram's parent -- subprogram is not itself hidden. (Note: This condition could probably -- be simplified, leaving out the testing for the specific controlled -- cases, but it seems safer and clearer this way, and echoes similar -- special-case tests of this kind in other places.) if Present (Overridden_Subp) and then (not Is_Hidden (Overridden_Subp) or else ((Chars (Overridden_Subp) = Name_Initialize or else Chars (Overridden_Subp) = Name_Adjust or else Chars (Overridden_Subp) = Name_Finalize) and then Present (Alias (Overridden_Subp)) and then not Is_Hidden (Alias (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; -- Special-case to fix a GNAT oddity: Limited_Controlled is declared -- as an extension of Root_Controlled, and thus has a useless Adjust -- operation. This operation should not be inherited by other limited -- controlled types. An explicit Adjust for them is not overriding. elsif Must_Override (Spec) and then Chars (Overridden_Subp) = Name_Adjust and then Is_Limited_Type (Etype (First_Formal (Subp))) and then Present (Alias (Overridden_Subp)) and then Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Alias (Overridden_Subp)))) then Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); elsif Is_Subprogram (Subp) then if Is_Init_Proc (Subp) then null; elsif No (Overridden_Operation (Subp)) then -- For entities generated by Derive_Subprograms the overridden -- operation is the inherited primitive (which is available -- through the attribute alias) if (Is_Dispatching_Operation (Subp) or else Is_Dispatching_Operation (Overridden_Subp)) and then not Comes_From_Source (Overridden_Subp) and then Find_Dispatching_Type (Overridden_Subp) = Find_Dispatching_Type (Subp) and then Present (Alias (Overridden_Subp)) and then Comes_From_Source (Alias (Overridden_Subp)) then Set_Overridden_Operation (Subp, Alias (Overridden_Subp)); else Set_Overridden_Operation (Subp, Overridden_Subp); end if; end if; end if; -- If primitive flag is set or this is a protected operation, then -- the operation is overriding at the point of its declaration, so -- warn if necessary. Otherwise it may have been declared before the -- operation it overrides and no check is required. if Style_Check and then not Must_Override (Spec) and then (Is_Primitive or else Ekind (Scope (Subp)) = E_Protected_Type) then Style.Missing_Overriding (Decl, Subp); end if; -- If Subp is an operator, it may override a predefined operation, if -- it is defined in the same scope as the type to which it applies. -- 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. elsif Nkind (Subp) = N_Defining_Operator_Symbol then if Must_Not_Override (Spec) then -- If this is not a primitive or a protected subprogram, then -- "not overriding" is illegal. if not Is_Primitive and then Ekind (Scope (Subp)) /= E_Protected_Type then Error_Msg_N ("overriding indicator only allowed " & "if subprogram is primitive", Subp); elsif Can_Override_Operator (Subp) then Error_Msg_NE ("subprogram& overrides predefined operator ", Spec, Subp); end if; elsif Must_Override (Spec) then if No (Overridden_Operation (Subp)) and then not Can_Override_Operator (Subp) then Error_Msg_NE ("subprogram & is not overriding", Spec, Subp); end if; elsif not Error_Posted (Subp) and then Style_Check and then Can_Override_Operator (Subp) and then not Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Subp))) then -- If style checks are enabled, indicate that the indicator is -- missing. However, at the point of declaration, the type of -- which this is a primitive operation may be private, in which -- case the indicator would be premature. if Has_Private_Declaration (Etype (Subp)) or else Has_Private_Declaration (Etype (First_Formal (Subp))) then null; else Style.Missing_Overriding (Decl, Subp); end if; end if; 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 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_N ("overriding indicator only allowed if subprogram is primitive", Subp); return; end if; 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; Proc : Entity_Id := Empty) is Handler : Node_Id; procedure Check_Statement_Sequence (L : List_Id); -- Internal recursive procedure to check a list of statements for proper -- termination by a return statement (or a transfer of control or a -- compound statement that is itself internally properly terminated). ------------------------------ -- Check_Statement_Sequence -- ------------------------------ procedure Check_Statement_Sequence (L : List_Id) is Last_Stm : Node_Id; Stm : Node_Id; Kind : Node_Kind; Raise_Exception_Call : Boolean; -- Set True if statement sequence terminated by Raise_Exception call -- or a Reraise_Occurrence call. begin Raise_Exception_Call := False; -- Get last real statement 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 -- <<L1>> -- target label for local exception -- begin -- estmts1 -- end; -- goto L3; -- <<L2>> -- begin -- estmts2 -- end; -- <<L3>> -- 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 -- Don't count call to SS_Release (can happen after Raise_Exception) or else (Nkind (Last_Stm) = N_Procedure_Call_Statement and then Nkind (Name (Last_Stm)) = N_Identifier and then Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release)) -- Don't count exception junk or else (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; -- Here we have the "real" last statement Kind := Nkind (Last_Stm); -- Transfer of control, OK. Note that in the No_Return procedure -- case, we already diagnosed any explicit return statements, so -- we can treat them as OK in this context. if Is_Transfer (Last_Stm) then return; -- Check cases of explicit non-indirect procedure calls elsif Kind = N_Procedure_Call_Statement and then Is_Entity_Name (Name (Last_Stm)) then -- Check call to Raise_Exception procedure which is treated -- specially, as is a call to Reraise_Occurrence. -- We suppress the warning in these cases since it is likely that -- the programmer really does not expect to deal with the case -- of Null_Occurrence, and thus would find a warning about a -- 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) then Raise_Exception_Call := True; -- For Raise_Exception call, test first argument, if it is -- an attribute reference for a 'Identity call, then we know -- that the call cannot possibly return. 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 then return; end if; end; end if; -- If statement, need to look inside if there is an else and check -- each constituent statement sequence for proper termination. elsif Kind = N_If_Statement and then Present (Else_Statements (Last_Stm)) then Check_Statement_Sequence (Then_Statements (Last_Stm)); Check_Statement_Sequence (Else_Statements (Last_Stm)); if Present (Elsif_Parts (Last_Stm)) then declare Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm)); begin while Present (Elsif_Part) loop Check_Statement_Sequence (Then_Statements (Elsif_Part)); Next (Elsif_Part); end loop; end; end if; return; -- Case statement, check each case for proper termination 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 Check_Statement_Sequence (Statements (Case_Alt)); Next_Non_Pragma (Case_Alt); end loop; end; return; -- Block statement, check its handled sequence of statements elsif Kind = N_Block_Statement then declare Err1 : Boolean; begin Check_Returns (Handled_Statement_Sequence (Last_Stm), Mode, Err1); if Err1 then Err := True; end if; return; end; -- Loop statement. If there is an iteration scheme, we can definitely -- fall out of the loop. Similarly if there is an exit statement, we -- can fall out. In either case we need a following return. elsif Kind = N_Loop_Statement then if Present (Iteration_Scheme (Last_Stm)) or else Has_Exit (Entity (Identifier (Last_Stm))) then null; -- A loop with no exit statement or iteration scheme is either -- an infinite loop, or it has some other exit (raise/return). -- In either case, no warning is required. else return; end if; -- Timed entry call, check entry call and delay alternatives -- Note: in expanded code, the timed entry call has been converted -- to a set of expanded statements on which the check will work -- correctly in any case. elsif Kind = N_Timed_Entry_Call then declare ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm); DCA : constant Node_Id := Delay_Alternative (Last_Stm); begin -- If statement sequence of entry call alternative is missing, -- then we can definitely fall through, and we post the error -- message on the entry call alternative itself. if No (Statements (ECA)) then Last_Stm := ECA; -- If statement sequence of delay alternative is missing, then -- we can definitely fall through, and we post the error -- message on the delay alternative itself. -- Note: if both ECA and DCA are missing the return, then we -- post only one message, should be enough to fix the bugs. -- If not we will get a message next time on the DCA when the -- ECA is fixed! elsif No (Statements (DCA)) then Last_Stm := DCA; -- Else check both statement sequences else Check_Statement_Sequence (Statements (ECA)); Check_Statement_Sequence (Statements (DCA)); return; end if; end; -- Conditional entry call, check entry call and else part -- Note: in expanded code, the conditional entry call has been -- converted to a set of expanded statements on which the check -- will work correctly in any case. elsif Kind = N_Conditional_Entry_Call then declare ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm); begin -- If statement sequence of entry call alternative is missing, -- then we can definitely fall through, and we post the error -- message on the entry call alternative itself. if No (Statements (ECA)) then Last_Stm := ECA; -- Else check statement sequence and else part else Check_Statement_Sequence (Statements (ECA)); Check_Statement_Sequence (Else_Statements (Last_Stm)); return; end if; end; end if; -- 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!", Last_Stm); end if; -- Note: we set Err even though we have not issued a warning -- because we still have a case of a missing return. This is -- an extremely marginal case, probably will never be noticed -- but we might as well get it right. Err := True; -- Otherwise we have the case of a procedure marked No_Return else 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; -- Start of processing for Check_Returns begin Err := False; Check_Statement_Sequence (Statements (HSS)); if Present (Exception_Handlers (HSS)) then Handler := First_Non_Pragma (Exception_Handlers (HSS)); while Present (Handler) loop Check_Statement_Sequence (Statements (Handler)); Next_Non_Pragma (Handler); end loop; end if; end Check_Returns; ------------------------------- -- Check_Subprogram_Contract -- ------------------------------- procedure Check_Subprogram_Contract (Spec_Id : Entity_Id) is -- Code is currently commented out as, in some cases, it causes crashes -- because Direct_Primitive_Operations is not available for a private -- type. This may cause more warnings to be issued than necessary. See -- below for the intended use of this variable. ??? -- Inherited : constant Subprogram_List := -- Inherited_Subprograms (Spec_Id); -- -- List of subprograms inherited by this subprogram Last_Postcondition : Node_Id := Empty; -- Last postcondition on the subprogram, or else Empty if either no -- postcondition or only inherited postconditions. Attribute_Result_Mentioned : Boolean := False; -- Whether attribute 'Result is mentioned in a postcondition Post_State_Mentioned : Boolean := False; -- Whether some expression mentioned in a postcondition can have a -- different value in the post-state than in the pre-state. function Check_Attr_Result (N : Node_Id) return Traverse_Result; -- Check if N is a reference to the attribute 'Result, and if so set -- Attribute_Result_Mentioned and return Abandon. Otherwise return OK. function Check_Post_State (N : Node_Id) return Traverse_Result; -- Check whether the value of evaluating N can be different in the -- post-state, compared to the same evaluation in the pre-state, and -- if so set Post_State_Mentioned and return Abandon. Return Skip on -- reference to attribute 'Old, in order to ignore its prefix, which -- is precisely evaluated in the pre-state. Otherwise return OK. procedure Process_Post_Conditions (Spec : Node_Id; Class : Boolean); -- This processes the Spec_PPC_List from Spec, processing any -- postconditions from the list. If Class is True, then only -- postconditions marked with Class_Present are considered. The -- caller has checked that Spec_PPC_List is non-Empty. function Find_Attribute_Result is new Traverse_Func (Check_Attr_Result); function Find_Post_State is new Traverse_Func (Check_Post_State); ----------------------- -- Check_Attr_Result -- ----------------------- function Check_Attr_Result (N : Node_Id) return Traverse_Result is begin if Nkind (N) = N_Attribute_Reference and then Get_Attribute_Id (Attribute_Name (N)) = Attribute_Result then Attribute_Result_Mentioned := True; return Abandon; else return OK; end if; end Check_Attr_Result; ---------------------- -- Check_Post_State -- ---------------------- function Check_Post_State (N : Node_Id) return Traverse_Result is Found : Boolean := False; begin case Nkind (N) is when N_Function_Call | N_Explicit_Dereference => Found := True; when N_Identifier | N_Expanded_Name => declare E : constant Entity_Id := Entity (N); begin -- ???Quantified expressions get analyzed later, so E can -- be empty at this point. In this case, we suppress the -- warning, just in case E is assignable. It seems better to -- have false negatives than false positives. At some point, -- we should make the warning more accurate, either by -- analyzing quantified expressions earlier, or moving -- this processing later. if No (E) or else (Is_Entity_Name (N) and then Ekind (E) in Assignable_Kind) then Found := True; end if; end; when N_Attribute_Reference => case Get_Attribute_Id (Attribute_Name (N)) is when Attribute_Old => return Skip; when Attribute_Result => Found := True; when others => null; end case; when others => null; end case; if Found then Post_State_Mentioned := True; return Abandon; else return OK; end if; end Check_Post_State; ----------------------------- -- Process_Post_Conditions -- ----------------------------- procedure Process_Post_Conditions (Spec : Node_Id; Class : Boolean) is Prag : Node_Id; Arg : Node_Id; Ignored : Traverse_Final_Result; pragma Unreferenced (Ignored); begin Prag := Spec_PPC_List (Contract (Spec)); loop Arg := First (Pragma_Argument_Associations (Prag)); -- Since pre- and post-conditions are listed in reverse order, the -- first postcondition in the list is the last in the source. if Pragma_Name (Prag) = Name_Postcondition and then not Class and then No (Last_Postcondition) then Last_Postcondition := Prag; end if; -- For functions, look for presence of 'Result in postcondition if Ekind_In (Spec_Id, E_Function, E_Generic_Function) then Ignored := Find_Attribute_Result (Arg); end if; -- For each individual non-inherited postcondition, look for -- presence of an expression that could be evaluated differently -- in post-state. if Pragma_Name (Prag) = Name_Postcondition and then not Class then Post_State_Mentioned := False; Ignored := Find_Post_State (Arg); if not Post_State_Mentioned then Error_Msg_N ("?postcondition refers only to pre-state", Prag); end if; end if; Prag := Next_Pragma (Prag); exit when No (Prag); end loop; end Process_Post_Conditions; -- Start of processing for Check_Subprogram_Contract begin if not Warn_On_Suspicious_Contract then return; end if; if Present (Spec_PPC_List (Contract (Spec_Id))) then Process_Post_Conditions (Spec_Id, Class => False); end if; -- Process inherited postconditions -- Code is currently commented out as, in some cases, it causes crashes -- because Direct_Primitive_Operations is not available for a private -- type. This may cause more warnings to be issued than necessary. ??? -- for J in Inherited'Range loop -- if Present (Spec_PPC_List (Contract (Inherited (J)))) then -- Process_Post_Conditions (Inherited (J), Class => True); -- end if; -- end loop; -- Issue warning for functions whose postcondition does not mention -- 'Result after all postconditions have been processed. if Ekind_In (Spec_Id, E_Function, E_Generic_Function) and then Present (Last_Postcondition) and then not Attribute_Result_Mentioned then Error_Msg_N ("?function postcondition does not mention result", Last_Postcondition); end if; end Check_Subprogram_Contract; ---------------------------- -- Check_Subprogram_Order -- ---------------------------- procedure Check_Subprogram_Order (N : Node_Id) is function Subprogram_Name_Greater (S1, S2 : String) return Boolean; -- This is used to check if S1 > S2 in the sense required by this test, -- for example nameab < namec, but name2 < name10. ----------------------------- -- Subprogram_Name_Greater -- ----------------------------- function Subprogram_Name_Greater (S1, S2 : String) return Boolean is L1, L2 : Positive; N1, N2 : Natural; begin -- Remove trailing numeric parts L1 := S1'Last; while S1 (L1) in '0' .. '9' loop L1 := L1 - 1; end loop; L2 := S2'Last; while S2 (L2) in '0' .. '9' loop L2 := L2 - 1; end loop; -- If non-numeric parts non-equal, that's decisive if S1 (S1'First .. L1) < S2 (S2'First .. L2) then return False; elsif S1 (S1'First .. L1) > S2 (S2'First .. L2) then return True; -- If non-numeric parts equal, compare suffixed numeric parts. Note -- that a missing suffix is treated as numeric zero in this test. else N1 := 0; while L1 < S1'Last loop L1 := L1 + 1; N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0'); end loop; N2 := 0; while L2 < S2'Last loop L2 := L2 + 1; N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0'); end loop; return N1 > N2; end if; end Subprogram_Name_Greater; -- Start of processing for Check_Subprogram_Order begin -- Check body in alpha order if this is option if Style_Check and then Style_Check_Order_Subprograms and then Nkind (N) = N_Subprogram_Body and then Comes_From_Source (N) and then In_Extended_Main_Source_Unit (N) then declare LSN : String_Ptr renames Scope_Stack.Table (Scope_Stack.Last).Last_Subprogram_Name; Body_Id : constant Entity_Id := Defining_Entity (Specification (N)); begin Get_Decoded_Name_String (Chars (Body_Id)); if LSN /= null then if Subprogram_Name_Greater (LSN.all, Name_Buffer (1 .. Name_Len)) then Style.Subprogram_Not_In_Alpha_Order (Body_Id); end if; Free (LSN); end if; LSN := new String'(Name_Buffer (1 .. Name_Len)); end; end if; end Check_Subprogram_Order; ------------------------------ -- Check_Subtype_Conformant -- ------------------------------ procedure Check_Subtype_Conformant (New_Id : Entity_Id; Old_Id : Entity_Id; Err_Loc : Node_Id := Empty; Skip_Controlling_Formals : Boolean := False) is Result : Boolean; pragma Warnings (Off, Result); begin Check_Conformance (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc, Skip_Controlling_Formals => Skip_Controlling_Formals); end Check_Subtype_Conformant; --------------------------- -- Check_Type_Conformant -- --------------------------- procedure Check_Type_Conformant (New_Id : Entity_Id; Old_Id : Entity_Id; 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); end Check_Type_Conformant; --------------------------- -- Can_Override_Operator -- --------------------------- function Can_Override_Operator (Subp : Entity_Id) return Boolean is Typ : Entity_Id; begin if Nkind (Subp) /= N_Defining_Operator_Symbol then return False; else Typ := Base_Type (Etype (First_Formal (Subp))); return Operator_Matches_Spec (Subp, Subp) and then Scope (Subp) = Scope (Typ) and then not Is_Class_Wide_Type (Typ); end if; end Can_Override_Operator; ---------------------- -- Conforming_Types -- ---------------------- function Conforming_Types (T1 : Entity_Id; T2 : Entity_Id; Ctype : Conformance_Type; Get_Inst : Boolean := False) return Boolean is Type_1 : Entity_Id := T1; Type_2 : Entity_Id := T2; 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. 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 -- ---------------------- function Base_Types_Match (T1, T2 : Entity_Id) return Boolean is begin if T1 = T2 then return True; elsif Base_Type (T1) = Base_Type (T2) then -- The following is too permissive. A more precise test should -- check that the generic actual is an ancestor subtype of the -- other ???. return not Is_Generic_Actual_Type (T1) or else not Is_Generic_Actual_Type (T2) or else Scope (T1) /= Scope (T2); 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; 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; elsif From_With_Type (T1) and then From_With_Type (T2) and then Available_View (T1) = Available_View (T2) then return True; else return False; end if; end Matches_Limited_With_View; -- Start of processing for Conforming_Types begin -- The context is an instance association for a formal -- access-to-subprogram type; the formal parameter types require -- mapping because they may denote other formal parameters of the -- generic unit. if Get_Inst then Type_1 := Get_Instance_Of (T1); Type_2 := Get_Instance_Of (T2); end if; -- 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 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); elsif Is_Incomplete_Or_Private_Type (Type_1) and then Present (Full_View (Type_1)) and then Base_Types_Match (Full_View (Type_1), Type_2) then return Ctype <= Mode_Conformant or else Subtypes_Statically_Match (Full_View (Type_1), Type_2); elsif Ekind (Type_2) = E_Incomplete_Type and then Present (Full_View (Type_2)) and then Base_Types_Match (Type_1, Full_View (Type_2)) then return Ctype <= Mode_Conformant or else Subtypes_Statically_Match (Type_1, Full_View (Type_2)); elsif Is_Private_Type (Type_2) and then In_Instance and then Present (Full_View (Type_2)) and then Base_Types_Match (Type_1, Full_View (Type_2)) then return Ctype <= Mode_Conformant or else Subtypes_Statically_Match (Type_1, Full_View (Type_2)); end if; -- Ada 2005 (AI-254): Anonymous access-to-subprogram types must be -- treated recursively because they carry a signature. Are_Anonymous_Access_To_Subprogram_Types := 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)). We check -- the base types because we may have built internal subtype entities -- to handle null-excluding types (see Process_Formals). 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 Desig_1 : Entity_Id; Desig_2 : Entity_Id; begin -- In Ada 2005, access constant indicators must match for -- subtype conformance. if Ada_Version >= Ada_2005 and then Ctype >= Subtype_Conformant and then Is_Access_Constant (Type_1) /= Is_Access_Constant (Type_2) then return False; end if; Desig_1 := Find_Designated_Type (Type_1); Desig_2 := Find_Designated_Type (Type_2); -- 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. if Get_Inst then Desig_1 := Get_Instance_Of (Desig_1); Desig_2 := Get_Instance_Of (Desig_2); end if; -- It is possible for a Class_Wide_Type to be introduced for an -- incomplete type, in which case there is a separate class_ wide -- type for the full view. The types conform if their Etypes -- conform, i.e. one may be the full view of the other. This can -- only happen in the context of an access parameter, other uses -- of an incomplete Class_Wide_Type are illegal. if Is_Class_Wide_Type (Desig_1) and then Is_Class_Wide_Type (Desig_2) then return Conforming_Types (Etype (Base_Type (Desig_1)), Etype (Base_Type (Desig_2)), Ctype); elsif Are_Anonymous_Access_To_Subprogram_Types then if Ada_Version < Ada_2005 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 or else Subtypes_Statically_Match (Desig_1, Desig_2)); end if; end; -- 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; -------------------------- -- Create_Extra_Formals -- -------------------------- 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 (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. -- The following suffixes are currently used. They should not be changed -- without coordinating with CodePeer, which makes use of these to -- provide better messages. -- O denotes the Constrained bit. -- L denotes the accessibility level. -- BIP_xxx denotes an extra formal for a build-in-place function. See -- the full list in exp_ch6.BIP_Formal_Kind. ---------------------- -- Add_Extra_Formal -- ---------------------- 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 (Assoc_Entity), Chars => New_External_Name (Chars (Assoc_Entity), Suffix => Suffix)); begin -- A little optimization. Never generate an extra formal for the -- _init operand of an initialization procedure, since it could -- never be used. if Chars (Formal) = Name_uInit then return Empty; end if; Set_Ekind (EF, E_In_Parameter); Set_Actual_Subtype (EF, Typ); Set_Etype (EF, Typ); Set_Scope (EF, Scope); Set_Mechanism (EF, Default_Mechanism); Set_Formal_Validity (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 determine the need -- for extra formals. if Is_Overloadable (E) and then Present (Alias (E)) then P_Formal := First_Formal (Alias (E)); end if; Last_Extra := Empty; Formal := First_Formal (E); while Present (Formal) loop Last_Extra := Formal; Next_Formal (Formal); end loop; -- 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) if Present (Last_Extra) and then Present (Extra_Formal (Last_Extra)) then return; end if; -- 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_Internal_Operation (E) then goto Test_For_Func_Result_Extras; end if; Formal := First_Formal (E); while Present (Formal) loop -- Create extra formal for supporting the attribute 'Constrained. -- The case of a private type view without discriminants also -- requires the extra formal if the underlying type has defaulted -- discriminants. if Ekind (Formal) /= E_In_Parameter then if Present (P_Formal) then Formal_Type := Etype (P_Formal); else Formal_Type := Etype (Formal); end if; -- Do not produce extra formals for Unchecked_Union parameters. -- Jump directly to the end of the loop. if Is_Unchecked_Union (Base_Type (Formal_Type)) then goto Skip_Extra_Formal_Generation; end if; if not Has_Discriminants (Formal_Type) and then Ekind (Formal_Type) in Private_Kind and then Present (Underlying_Type (Formal_Type)) then Formal_Type := Underlying_Type (Formal_Type); end if; -- Suppress the extra formal if formal's subtype is constrained or -- indefinite, or we're compiling for Ada 2012 and the underlying -- type is tagged and limited. In Ada 2012, a limited tagged type -- can have defaulted discriminants, but 'Constrained is required -- to return True, so the formal is never needed (see AI05-0214). -- Note that this ensures consistency of calling sequences for -- dispatching operations when some types in a class have defaults -- on discriminants and others do not (and requiring the extra -- formal would introduce distributed overhead). if Has_Discriminants (Formal_Type) and then not Is_Constrained (Formal_Type) and then not Is_Indefinite_Subtype (Formal_Type) and then (Ada_Version < Ada_2012 or else not (Is_Tagged_Type (Underlying_Type (Formal_Type)) and then Is_Limited_Type (Formal_Type))) then Set_Extra_Constrained (Formal, Add_Extra_Formal (Formal, Standard_Boolean, E, "O")); end if; end if; -- 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 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 (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 (No (P_Formal) or else Present (Extra_Accessibility (P_Formal))) then Set_Extra_Accessibility (Formal, Add_Extra_Formal (Formal, Standard_Natural, E, "L")); end if; -- This label is required when skipping extra formal generation for -- Unchecked_Union parameters. <<Skip_Extra_Formal_Generation>> if Present (P_Formal) then Next_Formal (P_Formal); end if; Next_Formal (Formal); end loop; <<Test_For_Func_Result_Extras>> -- Ada 2012 (AI05-234): "the accessibility level of the result of a -- function call is ... determined by the point of call ...". if Needs_Result_Accessibility_Level (E) then Set_Extra_Accessibility_Of_Result (E, Add_Extra_Formal (E, Standard_Natural, E, "L")); end if; -- 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_2005 and then Is_Build_In_Place_Function (E) then declare Result_Subt : constant Entity_Id := Etype (E); Full_Subt : constant Entity_Id := Available_View (Result_Subt); Formal_Typ : Entity_Id; Discard : Entity_Id; pragma Warnings (Off, Discard); begin -- In the case of functions with unconstrained result subtypes, -- add a 4-state formal indicating whether the return object is -- allocated by the caller (1), or should be allocated by the -- callee on the secondary stack (2), in the global heap (3), or -- in a user-defined storage pool (4). 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 Needs_BIP_Alloc_Form (E) then Discard := Add_Extra_Formal (E, Standard_Natural, E, BIP_Formal_Suffix (BIP_Alloc_Form)); -- Add BIP_Storage_Pool, in case BIP_Alloc_Form indicates to -- use a user-defined pool. This formal is not added on -- .NET/JVM/ZFP as those targets do not support pools. if VM_Target = No_VM and then RTE_Available (RE_Root_Storage_Pool_Ptr) then Discard := Add_Extra_Formal (E, RTE (RE_Root_Storage_Pool_Ptr), E, BIP_Formal_Suffix (BIP_Storage_Pool)); end if; end if; -- In the case of functions whose result type needs finalization, -- add an extra formal which represents the finalization master. if Needs_BIP_Finalization_Master (E) then Discard := Add_Extra_Formal (E, RTE (RE_Finalization_Master_Ptr), E, BIP_Formal_Suffix (BIP_Finalization_Master)); end if; -- When the result type contains tasks, add two extra formals: the -- master of the tasks to be created, and the caller's activation -- chain. if Has_Task (Full_Subt) then Discard := Add_Extra_Formal (E, RTE (RE_Master_Id), E, BIP_Formal_Suffix (BIP_Task_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. Formal_Typ := Create_Itype (E_Anonymous_Access_Type, E, Scope_Id => Scope (E)); Set_Directly_Designated_Type (Formal_Typ, Result_Subt); Set_Etype (Formal_Typ, Formal_Typ); Set_Depends_On_Private (Formal_Typ, Has_Private_Component (Formal_Typ)); Set_Is_Public (Formal_Typ, Is_Public (Scope (Formal_Typ))); Set_Is_Access_Constant (Formal_Typ, 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_Typ, From_With_Type (Result_Subt)); Layout_Type (Formal_Typ); Discard := Add_Extra_Formal (E, Formal_Typ, E, BIP_Formal_Suffix (BIP_Object_Access)); end; end if; end Create_Extra_Formals; ----------------------------- -- Enter_Overloaded_Entity -- ----------------------------- procedure Enter_Overloaded_Entity (S : Entity_Id) is E : Entity_Id := Current_Entity_In_Scope (S); C_E : Entity_Id := Current_Entity (S); begin if Present (E) then Set_Has_Homonym (E); Set_Has_Homonym (S); end if; Set_Is_Immediately_Visible (S); Set_Scope (S, Current_Scope); -- Chain new entity if front of homonym in current scope, so that -- homonyms are contiguous. if Present (E) and then E /= C_E then while Homonym (C_E) /= E loop C_E := Homonym (C_E); end loop; Set_Homonym (C_E, S); else E := C_E; Set_Current_Entity (S); end if; Set_Homonym (S, E); Append_Entity (S, Current_Scope); Set_Public_Status (S); if Debug_Flag_E then Write_Str ("New overloaded entity chain: "); Write_Name (Chars (S)); E := S; while Present (E) loop Write_Str (" "); Write_Int (Int (E)); E := Homonym (E); end loop; Write_Eol; end if; -- Generate warning for hiding if Warn_On_Hiding and then Comes_From_Source (S) and then In_Extended_Main_Source_Unit (S) then E := S; loop E := Homonym (E); exit when No (E); -- Warn unless genuine overloading. Do not emit warning on -- hiding predefined operators in Standard (these are either an -- (artifact of our implicit declarations, or simple noise) but -- keep warning on a operator defined on a local subtype, because -- of the real danger that different operators may be applied in -- various parts of the program. -- Note that if E and S have the same scope, there is never any -- hiding. Either the two conflict, and the program is illegal, -- or S is overriding an implicit inherited subprogram. if Scope (E) /= Scope (S) and then (not Is_Overloadable (E) or else Subtype_Conformant (E, S)) and then (Is_Immediately_Visible (E) or else Is_Potentially_Use_Visible (S)) then if Scope (E) /= Standard_Standard then Error_Msg_Sloc := Sloc (E); Error_Msg_N ("declaration of & hides one#?", S); elsif Nkind (S) = N_Defining_Operator_Symbol and then Scope (Base_Type (Etype (First_Formal (S)))) /= Scope (S) then Error_Msg_N ("declaration of & hides predefined operator?", S); end if; end if; end loop; end if; end Enter_Overloaded_Entity; ----------------------------- -- Check_Untagged_Equality -- ----------------------------- procedure Check_Untagged_Equality (Eq_Op : Entity_Id) is Typ : constant Entity_Id := Etype (First_Formal (Eq_Op)); Decl : constant Node_Id := Unit_Declaration_Node (Eq_Op); Obj_Decl : Node_Id; begin if Nkind (Decl) = N_Subprogram_Declaration and then Is_Record_Type (Typ) and then not Is_Tagged_Type (Typ) then -- If the type is not declared in a package, or if we are in the -- body of the package or in some other scope, the new operation is -- not primitive, and therefore legal, though suspicious. If the -- type is a generic actual (sub)type, the operation is not primitive -- either because the base type is declared elsewhere. if Is_Frozen (Typ) then if Ekind (Scope (Typ)) /= E_Package or else Scope (Typ) /= Current_Scope then null; elsif Is_Generic_Actual_Type (Typ) then null; elsif In_Package_Body (Scope (Typ)) then Error_Msg_NE ("equality operator must be declared " & "before type& is frozen", Eq_Op, Typ); Error_Msg_N ("\move declaration to package spec", Eq_Op); else Error_Msg_NE ("equality operator must be declared " & "before type& is frozen", Eq_Op, Typ); Obj_Decl := Next (Parent (Typ)); while Present (Obj_Decl) and then Obj_Decl /= Decl loop if Nkind (Obj_Decl) = N_Object_Declaration and then Etype (Defining_Identifier (Obj_Decl)) = Typ then Error_Msg_NE ("type& is frozen by declaration?", Obj_Decl, Typ); Error_Msg_N ("\an equality operator cannot be declared after this " & "point (RM 4.5.2 (9.8)) (Ada 2012))?", Obj_Decl); exit; end if; Next (Obj_Decl); end loop; end if; elsif not In_Same_List (Parent (Typ), Decl) and then not Is_Limited_Type (Typ) then -- This makes it illegal to have a primitive equality declared in -- the private part if the type is visible. Error_Msg_N ("equality operator appears too late", Eq_Op); end if; end if; end Check_Untagged_Equality; ----------------------------- -- Find_Corresponding_Spec -- ----------------------------- function Find_Corresponding_Spec (N : Node_Id; Post_Error : Boolean := True) return Entity_Id is Spec : constant Node_Id := Specification (N); Designator : constant Entity_Id := Defining_Entity (Spec); E : Entity_Id; begin E := Current_Entity (Designator); while Present (E) loop -- We are looking for a matching spec. It must have the same scope, -- and the same name, and either be type conformant, or be the case -- of a library procedure spec and its body (which belong to one -- another regardless of whether they are type conformant or not). if Scope (E) = Current_Scope then if Current_Scope = Standard_Standard or else (Ekind (E) = Ekind (Designator) and then Type_Conformant (E, Designator)) then -- Within an instantiation, we know that spec and body are -- subtype conformant, because they were subtype conformant -- in the generic. We choose the subtype-conformant entity -- here as well, to resolve spurious ambiguities in the -- instance that were not present in the generic (i.e. when -- two different types are given the same actual). If we are -- looking for a spec to match a body, full conformance is -- expected. if In_Instance then Set_Convention (Designator, Convention (E)); -- Skip past subprogram bodies and subprogram renamings that -- may appear to have a matching spec, but that aren't fully -- conformant with it. That can occur in cases where an -- actual type causes unrelated homographs in the instance. if Nkind_In (N, N_Subprogram_Body, N_Subprogram_Renaming_Declaration) and then Present (Homonym (E)) and then not Fully_Conformant (Designator, E) then goto Next_Entity; elsif not Subtype_Conformant (Designator, E) then goto Next_Entity; end if; end if; -- Ada 2012 (AI05-0165): For internally generated bodies of -- null procedures locate the internally generated spec. We -- enforce mode conformance since a tagged type may inherit -- from interfaces several null primitives which differ only -- in the mode of the formals. if not (Comes_From_Source (E)) and then Is_Null_Procedure (E) and then not Mode_Conformant (Designator, E) then null; elsif not Has_Completion (E) then if Nkind (N) /= N_Subprogram_Body_Stub then Set_Corresponding_Spec (N, E); end if; Set_Has_Completion (E); return E; elsif Nkind (Parent (N)) = N_Subunit then -- If this is the proper body of a subunit, the completion -- flag is set when analyzing the stub. 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 if present, because the -- current one is the explicit overriding. elsif Ekind (E) = E_Function and then Ada_Version >= Ada_2005 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 and then Nkind (Parent (E)) = N_Function_Specification then Remove (Unit_Declaration_Node (Corresponding_Body (Unit_Declaration_Node (E)))); return E; -- If expansion is disabled, or if the wrapper function has -- not been generated yet, this a late body overriding an -- inherited operation, or it is an overriding by some other -- declaration before the controlling result is frozen. In -- either case this is a declaration of a new entity. else return Empty; end if; -- If the body already exists, then this is an error unless -- the previous declaration is the implicit declaration of a -- derived subprogram. It is also legal for an instance to -- contain type conformant overloadable declarations (but the -- generic declaration may not), per 8.3(26/2). elsif No (Alias (E)) and then not Is_Intrinsic_Subprogram (E) and then not In_Instance and then Post_Error then Error_Msg_Sloc := Sloc (E); if Is_Imported (E) then Error_Msg_NE ("body not allowed for imported subprogram & declared#", N, E); else Error_Msg_NE ("duplicate body for & declared#", N, E); end if; end if; -- Child units cannot be overloaded, so a conformance mismatch -- between body and a previous spec is an error. elsif Is_Child_Unit (E) and then Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body and then Nkind (Parent (Unit_Declaration_Node (Designator))) = N_Compilation_Unit and then Post_Error then Error_Msg_N ("body of child unit does not match previous declaration", N); end if; end if; <<Next_Entity>> E := Homonym (E); end loop; -- On exit, we know that no previous declaration of subprogram exists return Empty; end Find_Corresponding_Spec; ---------------------- -- Fully_Conformant -- ---------------------- 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; end Fully_Conformant; ---------------------------------- -- Fully_Conformant_Expressions -- ---------------------------------- function Fully_Conformant_Expressions (Given_E1 : Node_Id; Given_E2 : Node_Id) return Boolean is E1 : constant Node_Id := Original_Node (Given_E1); E2 : constant Node_Id := Original_Node (Given_E2); -- We always test conformance on original nodes, since it is possible -- for analysis and/or expansion to make things look as though they -- conform when they do not, e.g. by converting 1+2 into 3. function FCE (Given_E1, Given_E2 : Node_Id) return Boolean renames Fully_Conformant_Expressions; function FCL (L1, L2 : List_Id) return Boolean; -- Compare elements of two lists for conformance. Elements have to -- be conformant, and actuals inserted as default parameters do not -- match explicit actuals with the same value. function FCO (Op_Node, Call_Node : Node_Id) return Boolean; -- Compare an operator node with a function call --------- -- FCL -- --------- function FCL (L1, L2 : List_Id) return Boolean is N1, N2 : Node_Id; begin if L1 = No_List then N1 := Empty; else N1 := First (L1); end if; if L2 = No_List then N2 := Empty; else N2 := First (L2); end if; -- Compare two lists, skipping rewrite insertions (we want to -- compare the original trees, not the expanded versions!) loop if Is_Rewrite_Insertion (N1) then Next (N1); elsif Is_Rewrite_Insertion (N2) then Next (N2); elsif No (N1) then return No (N2); elsif No (N2) then return False; elsif not FCE (N1, N2) then return False; else Next (N1); Next (N2); end if; end loop; end FCL; --------- -- FCO -- --------- function FCO (Op_Node, Call_Node : Node_Id) return Boolean is Actuals : constant List_Id := Parameter_Associations (Call_Node); Act : Node_Id; begin if No (Actuals) or else Entity (Op_Node) /= Entity (Name (Call_Node)) then return False; else Act := First (Actuals); if Nkind (Op_Node) in N_Binary_Op then if not FCE (Left_Opnd (Op_Node), Act) then return False; end if; Next (Act); end if; return Present (Act) and then FCE (Right_Opnd (Op_Node), Act) and then No (Next (Act)); end if; end FCO; -- Start of processing for Fully_Conformant_Expressions 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! if Paren_Count (E1) /= Paren_Count (E2) then return False; -- If same entities are referenced, then they are conformant even if -- they have different forms (RM 8.3.1(19-20)). elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then if Present (Entity (E1)) then return Entity (E1) = Entity (E2) or else (Chars (Entity (E1)) = Chars (Entity (E2)) and then Ekind (Entity (E1)) = E_Discriminant and then Ekind (Entity (E2)) = E_In_Parameter); elsif Nkind (E1) = N_Expanded_Name and then Nkind (E2) = N_Expanded_Name and then Nkind (Selector_Name (E1)) = N_Character_Literal and then Nkind (Selector_Name (E2)) = N_Character_Literal then return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2)); else -- Identifiers in component associations don't always have -- entities, but their names must conform. return Nkind (E1) = N_Identifier and then Nkind (E2) = N_Identifier and then Chars (E1) = Chars (E2); end if; elsif Nkind (E1) = N_Character_Literal and then Nkind (E2) = N_Expanded_Name then return Nkind (Selector_Name (E2)) = N_Character_Literal and then Chars (E1) = Chars (Selector_Name (E2)); elsif Nkind (E2) = N_Character_Literal and then Nkind (E1) = N_Expanded_Name then return Nkind (Selector_Name (E1)) = N_Character_Literal and then Chars (E2) = Chars (Selector_Name (E1)); elsif Nkind (E1) in N_Op and then Nkind (E2) = N_Function_Call then return FCO (E1, E2); elsif Nkind (E2) in N_Op and then Nkind (E1) = N_Function_Call then return FCO (E2, E1); -- Otherwise we must have the same syntactic entity elsif Nkind (E1) /= Nkind (E2) then return False; -- At this point, we specialize by node type else case Nkind (E1) is when N_Aggregate => return FCL (Expressions (E1), Expressions (E2)) and then FCL (Component_Associations (E1), Component_Associations (E2)); when N_Allocator => if Nkind (Expression (E1)) = N_Qualified_Expression or else Nkind (Expression (E2)) = N_Qualified_Expression then return FCE (Expression (E1), Expression (E2)); -- Check that the subtype marks and any constraints -- are conformant else declare Indic1 : constant Node_Id := Expression (E1); Indic2 : constant Node_Id := Expression (E2); Elt1 : Node_Id; Elt2 : Node_Id; begin if Nkind (Indic1) /= N_Subtype_Indication then return Nkind (Indic2) /= N_Subtype_Indication and then Entity (Indic1) = Entity (Indic2); elsif Nkind (Indic2) /= N_Subtype_Indication then return Nkind (Indic1) /= N_Subtype_Indication and then Entity (Indic1) = Entity (Indic2); else if Entity (Subtype_Mark (Indic1)) /= Entity (Subtype_Mark (Indic2)) then return False; end if; Elt1 := First (Constraints (Constraint (Indic1))); Elt2 := First (Constraints (Constraint (Indic2))); while Present (Elt1) and then Present (Elt2) loop if not FCE (Elt1, Elt2) then return False; end if; Next (Elt1); Next (Elt2); end loop; return True; end if; end; end if; when N_Attribute_Reference => return Attribute_Name (E1) = Attribute_Name (E2) and then FCL (Expressions (E1), Expressions (E2)); when N_Binary_Op => return Entity (E1) = Entity (E2) and then FCE (Left_Opnd (E1), Left_Opnd (E2)) and then FCE (Right_Opnd (E1), Right_Opnd (E2)); when N_Short_Circuit | N_Membership_Test => return FCE (Left_Opnd (E1), Left_Opnd (E2)) and then FCE (Right_Opnd (E1), Right_Opnd (E2)); when N_Case_Expression => declare Alt1 : Node_Id; Alt2 : Node_Id; begin if not FCE (Expression (E1), Expression (E2)) then return False; else Alt1 := First (Alternatives (E1)); Alt2 := First (Alternatives (E2)); loop if Present (Alt1) /= Present (Alt2) then return False; elsif No (Alt1) then return True; end if; if not FCE (Expression (Alt1), Expression (Alt2)) or else not FCL (Discrete_Choices (Alt1), Discrete_Choices (Alt2)) then return False; end if; Next (Alt1); Next (Alt2); end loop; end if; end; when N_Character_Literal => return Char_Literal_Value (E1) = Char_Literal_Value (E2); when N_Component_Association => return FCL (Choices (E1), Choices (E2)) and then FCE (Expression (E1), Expression (E2)); when N_Conditional_Expression => return FCL (Expressions (E1), Expressions (E2)); when N_Explicit_Dereference => return FCE (Prefix (E1), Prefix (E2)); when N_Extension_Aggregate => return FCL (Expressions (E1), Expressions (E2)) and then Null_Record_Present (E1) = Null_Record_Present (E2) and then FCL (Component_Associations (E1), Component_Associations (E2)); when N_Function_Call => return FCE (Name (E1), Name (E2)) and then FCL (Parameter_Associations (E1), Parameter_Associations (E2)); when N_Indexed_Component => return FCE (Prefix (E1), Prefix (E2)) and then FCL (Expressions (E1), Expressions (E2)); when N_Integer_Literal => return (Intval (E1) = Intval (E2)); when N_Null => return True; when N_Operator_Symbol => return Chars (E1) = Chars (E2); when N_Others_Choice => return True; when N_Parameter_Association => return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2)) and then FCE (Explicit_Actual_Parameter (E1), Explicit_Actual_Parameter (E2)); when N_Qualified_Expression => return FCE (Subtype_Mark (E1), Subtype_Mark (E2)) and then FCE (Expression (E1), Expression (E2)); when N_Quantified_Expression => if not FCE (Condition (E1), Condition (E2)) then return False; end if; if Present (Loop_Parameter_Specification (E1)) and then Present (Loop_Parameter_Specification (E2)) then declare L1 : constant Node_Id := Loop_Parameter_Specification (E1); L2 : constant Node_Id := Loop_Parameter_Specification (E2); begin return Reverse_Present (L1) = Reverse_Present (L2) and then FCE (Defining_Identifier (L1), Defining_Identifier (L2)) and then FCE (Discrete_Subtype_Definition (L1), Discrete_Subtype_Definition (L2)); end; else -- quantified expression with an iterator declare I1 : constant Node_Id := Iterator_Specification (E1); I2 : constant Node_Id := Iterator_Specification (E2); begin return FCE (Defining_Identifier (I1), Defining_Identifier (I2)) and then Of_Present (I1) = Of_Present (I2) and then Reverse_Present (I1) = Reverse_Present (I2) and then FCE (Name (I1), Name (I2)) and then FCE (Subtype_Indication (I1), Subtype_Indication (I2)); end; end if; when N_Range => return FCE (Low_Bound (E1), Low_Bound (E2)) and then FCE (High_Bound (E1), High_Bound (E2)); when N_Real_Literal => return (Realval (E1) = Realval (E2)); when N_Selected_Component => return FCE (Prefix (E1), Prefix (E2)) and then FCE (Selector_Name (E1), Selector_Name (E2)); when N_Slice => return FCE (Prefix (E1), Prefix (E2)) and then FCE (Discrete_Range (E1), Discrete_Range (E2)); when N_String_Literal => declare S1 : constant String_Id := Strval (E1); S2 : constant String_Id := Strval (E2); L1 : constant Nat := String_Length (S1); L2 : constant Nat := String_Length (S2); begin if L1 /= L2 then return False; else for J in 1 .. L1 loop if Get_String_Char (S1, J) /= Get_String_Char (S2, J) then return False; end if; end loop; return True; end if; end; when N_Type_Conversion => return FCE (Subtype_Mark (E1), Subtype_Mark (E2)) and then FCE (Expression (E1), Expression (E2)); when N_Unary_Op => return Entity (E1) = Entity (E2) and then FCE (Right_Opnd (E1), Right_Opnd (E2)); when N_Unchecked_Type_Conversion => return FCE (Subtype_Mark (E1), Subtype_Mark (E2)) and then FCE (Expression (E1), Expression (E2)); -- All other node types cannot appear in this context. Strictly -- we should raise a fatal internal error. Instead we just ignore -- the nodes. This means that if anyone makes a mistake in the -- expander and mucks an expression tree irretrievably, the -- result will be a failure to detect a (probably very obscure) -- case of non-conformance, which is better than bombing on some -- case where two expressions do in fact conform. when others => return True; end case; end if; end Fully_Conformant_Expressions; ---------------------------------------- -- Fully_Conformant_Discrete_Subtypes -- ---------------------------------------- function Fully_Conformant_Discrete_Subtypes (Given_S1 : Node_Id; Given_S2 : Node_Id) return Boolean is S1 : constant Node_Id := Original_Node (Given_S1); S2 : constant Node_Id := Original_Node (Given_S2); function Conforming_Bounds (B1, B2 : Node_Id) return Boolean; -- Special-case for a bound given by a discriminant, which in the body -- is replaced with the discriminal of the enclosing type. 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) and then Is_Entity_Name (B2) and then Ekind (Entity (B1)) = E_Discriminant then return Chars (B1) = Chars (B2); else return Fully_Conformant_Expressions (B1, B2); end if; end Conforming_Bounds; ----------------------- -- Conforming_Ranges -- ----------------------- function Conforming_Ranges (R1, R2 : Node_Id) return Boolean is begin return Conforming_Bounds (Low_Bound (R1), Low_Bound (R2)) and then Conforming_Bounds (High_Bound (R1), High_Bound (R2)); end Conforming_Ranges; -- Start of processing for Fully_Conformant_Discrete_Subtypes begin if Nkind (S1) /= Nkind (S2) then return False; elsif Is_Entity_Name (S1) then return Entity (S1) = Entity (S2); elsif Nkind (S1) = N_Range then return Conforming_Ranges (S1, S2); elsif Nkind (S1) = N_Subtype_Indication then return Entity (Subtype_Mark (S1)) = Entity (Subtype_Mark (S2)) and then Conforming_Ranges (Range_Expression (Constraint (S1)), Range_Expression (Constraint (S2))); else return True; end if; end Fully_Conformant_Discrete_Subtypes; -------------------- -- Install_Entity -- -------------------- procedure Install_Entity (E : Entity_Id) is Prev : constant Entity_Id := Current_Entity (E); begin Set_Is_Immediately_Visible (E); Set_Current_Entity (E); Set_Homonym (E, Prev); end Install_Entity; --------------------- -- Install_Formals -- --------------------- 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); end loop; end Install_Formals; ----------------------------- -- Is_Interface_Conformant -- ----------------------------- function Is_Interface_Conformant (Tagged_Type : Entity_Id; Iface_Prim : Entity_Id; Prim : Entity_Id) return Boolean is Iface : constant Entity_Id := Find_Dispatching_Type (Iface_Prim); Typ : constant Entity_Id := Find_Dispatching_Type (Prim); function Controlling_Formal (Prim : Entity_Id) return Entity_Id; -- Return the controlling formal of Prim ------------------------ -- Controlling_Formal -- ------------------------ function Controlling_Formal (Prim : Entity_Id) return Entity_Id is E : Entity_Id := First_Entity (Prim); begin while Present (E) loop if Is_Formal (E) and then Is_Controlling_Formal (E) then return E; end if; Next_Entity (E); end loop; return Empty; end Controlling_Formal; -- Local variables Iface_Ctrl_F : constant Entity_Id := Controlling_Formal (Iface_Prim); Prim_Ctrl_F : constant Entity_Id := Controlling_Formal (Prim); -- Start of processing for Is_Interface_Conformant begin pragma Assert (Is_Subprogram (Iface_Prim) and then Is_Subprogram (Prim) and then Is_Dispatching_Operation (Iface_Prim) and then Is_Dispatching_Operation (Prim)); pragma Assert (Is_Interface (Iface) or else (Present (Alias (Iface_Prim)) and then Is_Interface (Find_Dispatching_Type (Ultimate_Alias (Iface_Prim))))); if Prim = Iface_Prim or else not Is_Subprogram (Prim) or else Ekind (Prim) /= Ekind (Iface_Prim) or else not Is_Dispatching_Operation (Prim) or else Scope (Prim) /= Scope (Tagged_Type) or else No (Typ) or else Base_Type (Typ) /= Tagged_Type or else not Primitive_Names_Match (Iface_Prim, Prim) then return False; -- The mode of the controlling formals must match elsif Present (Iface_Ctrl_F) and then Present (Prim_Ctrl_F) and then Ekind (Iface_Ctrl_F) /= Ekind (Prim_Ctrl_F) then return False; -- Case of a procedure, or a function whose result type matches the -- result type of the interface primitive, or a function that has no -- controlling result (I or access I). elsif Ekind (Iface_Prim) = E_Procedure or else Etype (Prim) = Etype (Iface_Prim) or else not Has_Controlling_Result (Prim) then return Type_Conformant (Iface_Prim, Prim, Skip_Controlling_Formals => True); -- Case of a function returning an interface, or an access to one. -- Check that the return types correspond. elsif Implements_Interface (Typ, Iface) then if (Ekind (Etype (Prim)) = E_Anonymous_Access_Type) /= (Ekind (Etype (Iface_Prim)) = E_Anonymous_Access_Type) then return False; else return Type_Conformant (Prim, Iface_Prim, Skip_Controlling_Formals => True); end if; else return False; end if; end Is_Interface_Conformant; --------------------------------- -- Is_Non_Overriding_Operation -- --------------------------------- function Is_Non_Overriding_Operation (Prev_E : Entity_Id; New_E : Entity_Id) return Boolean is Formal : Entity_Id; F_Typ : Entity_Id; 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. function Types_Correspond (P_Type : Entity_Id; N_Type : Entity_Id) return Boolean; -- Returns true if and only if the types (or designated types in the -- case of anonymous access types) are the same or N_Type is derived -- directly or indirectly from P_Type. ----------------------------- -- Get_Generic_Parent_Type -- ----------------------------- function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is G_Typ : Entity_Id; Defn : Node_Id; Indic : Node_Id; begin if Is_Derived_Type (F_Typ) and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration then -- The tree must be traversed to determine the parent subtype in -- the generic unit, which unfortunately isn't always available -- via semantic attributes. ??? (Note: The use of Original_Node -- is needed for cases where a full derived type has been -- rewritten.) Defn := Type_Definition (Original_Node (Parent (F_Typ))); if Nkind (Defn) = N_Derived_Type_Definition then Indic := Subtype_Indication (Defn); if Nkind (Indic) = N_Subtype_Indication then G_Typ := Entity (Subtype_Mark (Indic)); else G_Typ := Entity (Indic); end if; if Nkind (Parent (G_Typ)) = N_Subtype_Declaration and then Present (Generic_Parent_Type (Parent (G_Typ))) then return Generic_Parent_Type (Parent (G_Typ)); end if; end if; end if; return Empty; end Get_Generic_Parent_Type; ---------------------- -- Types_Correspond -- ---------------------- function Types_Correspond (P_Type : Entity_Id; N_Type : Entity_Id) return Boolean is Prev_Type : Entity_Id := Base_Type (P_Type); New_Type : Entity_Id := Base_Type (N_Type); begin if Ekind (Prev_Type) = E_Anonymous_Access_Type then Prev_Type := Designated_Type (Prev_Type); end if; if Ekind (New_Type) = E_Anonymous_Access_Type then New_Type := Designated_Type (New_Type); end if; if Prev_Type = New_Type then return True; elsif not Is_Class_Wide_Type (New_Type) then while Etype (New_Type) /= New_Type loop New_Type := Etype (New_Type); if New_Type = Prev_Type then return True; end if; end loop; end if; return False; end Types_Correspond; -- Start of processing for Is_Non_Overriding_Operation begin -- In the case where both operations are implicit derived subprograms -- then neither overrides the other. This can only occur in certain -- obscure cases (e.g., derivation from homographs created in a generic -- instantiation). if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then return True; elsif Ekind (Current_Scope) = E_Package and then Is_Generic_Instance (Current_Scope) and then In_Private_Part (Current_Scope) and then Comes_From_Source (New_E) then -- We examine the formals and result type of the inherited operation, -- to determine whether their type is derived from (the instance of) -- a generic type. The first such formal or result type is the one -- tested. Formal := First_Formal (Prev_E); while Present (Formal) loop F_Typ := Base_Type (Etype (Formal)); if Ekind (F_Typ) = E_Anonymous_Access_Type then F_Typ := Designated_Type (F_Typ); end if; G_Typ := Get_Generic_Parent_Type (F_Typ); exit when Present (G_Typ); Next_Formal (Formal); end loop; 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; if No (G_Typ) then return False; end if; -- If the generic type is a private type, then the original operation -- was not overriding in the generic, because there was no primitive -- operation to override. if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration and then Nkind (Formal_Type_Definition (Parent (G_Typ))) = N_Formal_Private_Type_Definition then return True; -- The generic parent type is the ancestor of a formal derived -- type declaration. We need to check whether it has a primitive -- operation that should be overridden by New_E in the generic. else declare P_Formal : Entity_Id; N_Formal : Entity_Id; P_Typ : Entity_Id; N_Typ : Entity_Id; P_Prim : Entity_Id; Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ)); begin while Present (Prim_Elt) loop P_Prim := Node (Prim_Elt); if Chars (P_Prim) = Chars (New_E) and then Ekind (P_Prim) = Ekind (New_E) then P_Formal := First_Formal (P_Prim); N_Formal := First_Formal (New_E); while Present (P_Formal) and then Present (N_Formal) loop P_Typ := Etype (P_Formal); N_Typ := Etype (N_Formal); if not Types_Correspond (P_Typ, N_Typ) then exit; end if; Next_Entity (P_Formal); Next_Entity (N_Formal); end loop; -- Found a matching primitive operation belonging to the -- formal ancestor type, so the new subprogram is -- overriding. if No (P_Formal) and then No (N_Formal) and then (Ekind (New_E) /= E_Function or else Types_Correspond (Etype (P_Prim), Etype (New_E))) then return False; end if; end if; Next_Elmt (Prim_Elt); end loop; -- If no match found, then the new subprogram does not -- override in the generic (nor in the instance). -- If the type in question is not abstract, and the subprogram -- is, this will be an error if the new operation is in the -- private part of the instance. Emit a warning now, which will -- make the subsequent error message easier to understand. if not Is_Abstract_Type (F_Typ) and then Is_Abstract_Subprogram (Prev_E) and then In_Private_Part (Current_Scope) then Error_Msg_Node_2 := F_Typ; Error_Msg_NE ("private operation& in generic unit does not override " & "any primitive operation of& (RM 12.3 (18))?", New_E, New_E); end if; return True; end; end if; else return False; end if; end Is_Non_Overriding_Operation; ------------------------------------- -- List_Inherited_Pre_Post_Aspects -- ------------------------------------- procedure List_Inherited_Pre_Post_Aspects (E : Entity_Id) is begin if Opt.List_Inherited_Aspects and then (Is_Subprogram (E) or else Is_Generic_Subprogram (E)) then declare Inherited : constant Subprogram_List := Inherited_Subprograms (E); P : Node_Id; begin for J in Inherited'Range loop P := Spec_PPC_List (Contract (Inherited (J))); while Present (P) loop Error_Msg_Sloc := Sloc (P); if Class_Present (P) and then not Split_PPC (P) then if Pragma_Name (P) = Name_Precondition then Error_Msg_N ("?info: & inherits `Pre''Class` aspect from #", E); else Error_Msg_N ("?info: & inherits `Post''Class` aspect from #", E); end if; end if; P := Next_Pragma (P); end loop; end loop; end; end if; end List_Inherited_Pre_Post_Aspects; ------------------------------ -- Make_Inequality_Operator -- ------------------------------ -- S is the defining identifier of an equality operator. We build a -- subprogram declaration with the right signature. This operation is -- intrinsic, because it is always expanded as the negation of the -- call to the equality function. procedure Make_Inequality_Operator (S : Entity_Id) is Loc : constant Source_Ptr := Sloc (S); Decl : Node_Id; Formals : List_Id; Op_Name : Entity_Id; FF : constant Entity_Id := First_Formal (S); NF : constant Entity_Id := Next_Formal (FF); begin -- Check that equality was properly defined, ignore call if not if No (NF) then return; 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)); 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; ---------------------- -- May_Need_Actuals -- ---------------------- procedure May_Need_Actuals (Fun : Entity_Id) is F : Entity_Id; B : Boolean; begin F := First_Formal (Fun); B := True; while Present (F) loop if No (Default_Value (F)) then B := False; exit; end if; Next_Formal (F); end loop; Set_Needs_No_Actuals (Fun, B); end May_Need_Actuals; --------------------- -- Mode_Conformant -- --------------------- function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is Result : Boolean; begin Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result); return Result; end Mode_Conformant; --------------------------- -- New_Overloaded_Entity -- --------------------------- procedure New_Overloaded_Entity (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; -- 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; 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. function Is_Overriding_Alias (Old_E : Entity_Id; New_E : Entity_Id) return Boolean; -- Check whether new subprogram and old subprogram are both inherited -- from subprograms that have distinct dispatch table entries. This can -- occur with derivations from instances with accidental homonyms. -- The function is conservative given that the converse is only true -- within instances that contain accidental overloadings. ------------------------------------ -- Check_For_Primitive_Subprogram -- ------------------------------------ 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; function Visible_Part_Type (T : Entity_Id) return Boolean; -- Returns true if T is declared in the visible part of the current -- package scope; otherwise returns false. Assumes that T is declared -- in a package. procedure Check_Private_Overriding (T : Entity_Id); -- Checks that if a primitive abstract subprogram of a visible -- abstract type is declared in a private part, then it must override -- an abstract subprogram declared in the visible part. Also checks -- that if a primitive function with a controlling result is declared -- in a private part, then it must override a function declared in -- the visible part. ------------------------------ -- Check_Private_Overriding -- ------------------------------ procedure Check_Private_Overriding (T : Entity_Id) is begin if Is_Package_Or_Generic_Package (Current_Scope) and then In_Private_Part (Current_Scope) and then Visible_Part_Type (T) and then not In_Instance then 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 " & "(RM 3.9.3(10))!", S); elsif Ekind (S) = E_Function and then not Is_Overriding then if Is_Tagged_Type (T) and then T = Base_Type (Etype (S)) then Error_Msg_N ("private function with tagged result must" & " override visible-part function", S); Error_Msg_N ("\move subprogram to the visible part" & " (RM 3.9.3(10))", S); -- AI05-0073: extend this test to the case of a function -- with a controlling access result. elsif Ekind (Etype (S)) = E_Anonymous_Access_Type and then Is_Tagged_Type (Designated_Type (Etype (S))) and then not Is_Class_Wide_Type (Designated_Type (Etype (S))) and then Ada_Version >= Ada_2012 then Error_Msg_N ("private function with controlling access result " & "must override visible-part function", S); Error_Msg_N ("\move subprogram to the visible part" & " (RM 3.9.3(10))", S); end if; end if; end if; end Check_Private_Overriding; ----------------------- -- Visible_Part_Type -- ----------------------- function Visible_Part_Type (T : Entity_Id) return Boolean is P : constant Node_Id := Unit_Declaration_Node (Scope (T)); N : Node_Id; begin -- If the entity is a private type, then it must be declared in a -- visible part. if Ekind (T) in Private_Kind then return True; end if; -- Otherwise, we traverse the visible part looking for its -- corresponding declaration. We cannot use the declaration -- node directly because in the private part the entity of a -- private type is the one in the full view, which does not -- indicate that it is the completion of something visible. N := First (Visible_Declarations (Specification (P))); while Present (N) loop if Nkind (N) = N_Full_Type_Declaration and then Present (Defining_Identifier (N)) and then T = Defining_Identifier (N) then return True; 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 return True; end if; Next (N); end loop; return False; end Visible_Part_Type; -- Start of processing for Check_For_Primitive_Subprogram begin Is_Primitive := False; if not Comes_From_Source (S) then null; -- If subprogram is at library level, it is not primitive operation elsif Current_Scope = Standard_Standard then null; elsif (Is_Package_Or_Generic_Package (Current_Scope) and then not In_Package_Body (Current_Scope)) or else Is_Overriding then -- For function, check return type if Ekind (S) = E_Function then 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 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; -- For all subprograms, check formals Formal := First_Formal (S); while Present (Formal) loop if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then F_Typ := Designated_Type (Etype (Formal)); else F_Typ := Etype (Formal); end if; B_Typ := Base_Type (F_Typ); 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; Next_Formal (Formal); end loop; end if; end Check_For_Primitive_Subprogram; ----------------------------------- -- Check_Synchronized_Overriding -- ----------------------------------- procedure Check_Synchronized_Overriding (Def_Id : Entity_Id; Overridden_Subp : out Entity_Id) is Ifaces_List : Elist_Id; In_Scope : Boolean; Typ : Entity_Id; function Matches_Prefixed_View_Profile (Prim_Params : List_Id; Iface_Params : List_Id) return Boolean; -- Determine whether a subprogram's parameter profile Prim_Params -- matches that of a potentially overridden interface subprogram -- Iface_Params. Also determine if the type of first parameter of -- Iface_Params is an implemented interface. ----------------------------------- -- Matches_Prefixed_View_Profile -- ----------------------------------- function Matches_Prefixed_View_Profile (Prim_Params : List_Id; Iface_Params : List_Id) return Boolean is Iface_Id : Entity_Id; Iface_Param : Node_Id; Iface_Typ : Entity_Id; Prim_Id : Entity_Id; Prim_Param : Node_Id; Prim_Typ : Entity_Id; function Is_Implemented (Ifaces_List : Elist_Id; Iface : Entity_Id) return Boolean; -- Determine if Iface is implemented by the current task or -- protected type. -------------------- -- Is_Implemented -- -------------------- function Is_Implemented (Ifaces_List : Elist_Id; Iface : Entity_Id) return Boolean is Iface_Elmt : Elmt_Id; begin Iface_Elmt := First_Elmt (Ifaces_List); while Present (Iface_Elmt) loop if Node (Iface_Elmt) = Iface then return True; end if; Next_Elmt (Iface_Elmt); end loop; return False; end Is_Implemented; -- Start of processing for Matches_Prefixed_View_Profile begin Iface_Param := First (Iface_Params); Iface_Typ := Etype (Defining_Identifier (Iface_Param)); if Is_Access_Type (Iface_Typ) then Iface_Typ := Designated_Type (Iface_Typ); end if; Prim_Param := First (Prim_Params); -- The first parameter of the potentially overridden subprogram -- must be an interface implemented by Prim. if not Is_Interface (Iface_Typ) or else not Is_Implemented (Ifaces_List, Iface_Typ) then return False; end if; -- The checks on the object parameters are done, move onto the -- rest of the parameters. if not In_Scope then Prim_Param := Next (Prim_Param); end if; Iface_Param := Next (Iface_Param); while Present (Iface_Param) and then Present (Prim_Param) loop Iface_Id := Defining_Identifier (Iface_Param); Iface_Typ := Find_Parameter_Type (Iface_Param); Prim_Id := Defining_Identifier (Prim_Param); Prim_Typ := Find_Parameter_Type (Prim_Param); if Ekind (Iface_Typ) = E_Anonymous_Access_Type and then Ekind (Prim_Typ) = E_Anonymous_Access_Type and then Is_Concurrent_Type (Designated_Type (Prim_Typ)) then Iface_Typ := Designated_Type (Iface_Typ); Prim_Typ := Designated_Type (Prim_Typ); end if; -- Case of multiple interface types inside a parameter profile -- (Obj_Param : in out Iface; ...; Param : Iface) -- If the interface type is implemented, then the matching type -- in the primitive should be the implementing record type. if Ekind (Iface_Typ) = E_Record_Type and then Is_Interface (Iface_Typ) and then Is_Implemented (Ifaces_List, Iface_Typ) then if Prim_Typ /= Typ then return False; end if; -- The two parameters must be both mode and subtype conformant elsif Ekind (Iface_Id) /= Ekind (Prim_Id) or else not Conforming_Types (Iface_Typ, Prim_Typ, Subtype_Conformant) then return False; end if; Next (Iface_Param); Next (Prim_Param); end loop; -- One of the two lists contains more parameters than the other if Present (Iface_Param) or else Present (Prim_Param) then return False; end if; return True; end Matches_Prefixed_View_Profile; -- Start of processing for Check_Synchronized_Overriding begin Overridden_Subp := Empty; -- Def_Id must be an entry or a subprogram. We should skip predefined -- primitives internally generated by the frontend; however at this -- stage predefined primitives are still not fully decorated. As a -- minor optimization we skip here internally generated subprograms. if (Ekind (Def_Id) /= E_Entry and then Ekind (Def_Id) /= E_Function and then Ekind (Def_Id) /= E_Procedure) or else not Comes_From_Source (Def_Id) 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 enclosing scope is not a synchronized type and the subprogram -- has no formals. elsif No (First_Formal (Def_Id)) then return; -- The subprogram has formals and hence it may be a primitive of a -- concurrent type. else Typ := Etype (First_Formal (Def_Id)); if Is_Access_Type (Typ) then Typ := Directly_Designated_Type (Typ); end if; if Is_Concurrent_Type (Typ) and then not Is_Generic_Actual_Type (Typ) then 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 (Typ) and then not Is_Class_Wide_Type (Typ) and then Present (Corresponding_Concurrent_Type (Typ)) then Typ := Corresponding_Concurrent_Type (Typ); In_Scope := False; else return; end if; end if; -- There is no overriding to check if is an inherited operation in a -- type derivation on for a generic actual. Collect_Interfaces (Typ, Ifaces_List); if Is_Empty_Elmt_List (Ifaces_List) then return; end if; -- Determine whether entry or subprogram Def_Id overrides a primitive -- operation that belongs to one of the interfaces in Ifaces_List. declare Candidate : Entity_Id := Empty; Hom : Entity_Id := Empty; Iface_Typ : Entity_Id; Subp : Entity_Id := Empty; begin -- Traverse the homonym chain, looking for a potentially -- overridden subprogram that belongs to an implemented -- interface. Hom := Current_Entity_In_Scope (Def_Id); while Present (Hom) loop Subp := Hom; if Subp = Def_Id or else not Is_Overloadable (Subp) or else not Is_Primitive (Subp) or else not Is_Dispatching_Operation (Subp) or else not Present (Find_Dispatching_Type (Subp)) or else not Is_Interface (Find_Dispatching_Type (Subp)) then null; -- Entries and procedures can override abstract or null -- interface procedures. elsif (Ekind (Def_Id) = E_Procedure or else Ekind (Def_Id) = E_Entry) and then Ekind (Subp) = E_Procedure and then Matches_Prefixed_View_Profile (Parameter_Specifications (Parent (Def_Id)), Parameter_Specifications (Parent (Subp))) then Candidate := Subp; -- For an overridden subprogram Subp, check whether the mode -- of its first parameter is correct depending on the kind -- of synchronized type. declare Formal : constant Node_Id := First_Formal (Candidate); begin -- In order for an entry or a protected procedure to -- override, the first parameter of the overridden -- routine must be of mode "out", "in out" or -- access-to-variable. if (Ekind (Candidate) = E_Entry or else Ekind (Candidate) = E_Procedure) and then Is_Protected_Type (Typ) and then Ekind (Formal) /= E_In_Out_Parameter and then Ekind (Formal) /= E_Out_Parameter and then Nkind (Parameter_Type (Parent (Formal))) /= N_Access_Definition then null; -- All other cases are OK since a task entry or routine -- does not have a restriction on the mode of the first -- parameter of the overridden interface routine. else Overridden_Subp := Candidate; return; end if; end; -- Functions can override abstract interface functions elsif Ekind (Def_Id) = E_Function and then Ekind (Subp) = E_Function and then Matches_Prefixed_View_Profile (Parameter_Specifications (Parent (Def_Id)), Parameter_Specifications (Parent (Subp))) and then Etype (Result_Definition (Parent (Def_Id))) = Etype (Result_Definition (Parent (Subp))) then Overridden_Subp := Subp; return; end if; Hom := Homonym (Hom); end loop; -- After examining all candidates for overriding, we are left with -- the best match which is a mode incompatible interface routine. -- Do not emit an error if the Expander is active since this error -- will be detected later on after all concurrent types are -- expanded and all wrappers are built. This check is meant for -- spec-only compilations. if Present (Candidate) and then not Expander_Active then Iface_Typ := Find_Parameter_Type (Parent (First_Formal (Candidate))); -- Def_Id is primitive of a protected type, declared inside the -- type, and the candidate is primitive of a limited or -- synchronized interface. if In_Scope and then Is_Protected_Type (Typ) and then (Is_Limited_Interface (Iface_Typ) or else Is_Protected_Interface (Iface_Typ) or else Is_Synchronized_Interface (Iface_Typ) or else Is_Task_Interface (Iface_Typ)) then Error_Msg_PT (Parent (Typ), Candidate); end if; end if; Overridden_Subp := Candidate; return; end; 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; -------------------------- -- Is_Overriding_Alias -- -------------------------- function Is_Overriding_Alias (Old_E : Entity_Id; New_E : Entity_Id) return Boolean is AO : constant Entity_Id := Alias (Old_E); AN : constant Entity_Id := Alias (New_E); begin return Scope (AO) /= Scope (AN) or else No (DTC_Entity (AO)) or else No (DTC_Entity (AN)) or else DT_Position (AO) = DT_Position (AN); end Is_Overriding_Alias; -- Start of processing for New_Overloaded_Entity begin -- We need to look for an entity that S may override. This must be a -- homonym in the current scope, so we look for the first homonym of -- S in the current scope as the starting point for the search. E := Current_Entity_In_Scope (S); -- Ada 2005 (AI-251): Derivation of abstract interface primitives. -- They are directly added to the list of primitive operations of -- Derived_Type, unless this is a rederivation in the private part -- of an operation that was already derived in the visible part of -- the current package. if Ada_Version >= Ada_2005 and then Present (Derived_Type) and then Present (Alias (S)) and then Is_Dispatching_Operation (Alias (S)) and then Present (Find_Dispatching_Type (Alias (S))) and then Is_Interface (Find_Dispatching_Type (Alias (S))) then -- For private types, when the full-view is processed we propagate to -- the full view the non-overridden entities whose attribute "alias" -- references an interface primitive. These entities were added by -- Derive_Subprograms to ensure that interface primitives are -- covered. -- Inside_Freeze_Actions is non zero when S corresponds with an -- internal entity that links an interface primitive with its -- covering primitive through attribute Interface_Alias (see -- Add_Internal_Interface_Entities). if Inside_Freezing_Actions = 0 and then Is_Package_Or_Generic_Package (Current_Scope) and then In_Private_Part (Current_Scope) and then Nkind (Parent (E)) = N_Private_Extension_Declaration and then Nkind (Parent (S)) = N_Full_Type_Declaration and then Full_View (Defining_Identifier (Parent (E))) = Defining_Identifier (Parent (S)) and then Alias (E) = Alias (S) then Check_Operation_From_Private_View (S, E); Set_Is_Dispatching_Operation (S); -- Common case else Enter_Overloaded_Entity (S); Check_Dispatching_Operation (S, Empty); Check_For_Primitive_Subprogram (Is_Primitive_Subp); end if; return; end if; -- If there is no homonym then this is definitely not overriding if No (E) then Enter_Overloaded_Entity (S); Check_Dispatching_Operation (S, Empty); 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, Overridden_Subp); -- (Ada 2012: AI05-0125-1): If S is a dispatching operation then -- it may have overridden some hidden inherited primitive. Update -- Overridden_Subp to avoid spurious errors when checking the -- overriding indicator. if Ada_Version >= Ada_2012 and then No (Overridden_Subp) and then Is_Dispatching_Operation (S) and then Present (Overridden_Operation (S)) then Overridden_Subp := Overridden_Operation (S); end if; 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. elsif not Is_Overloadable (E) then -- Check for spurious conflict produced by a subprogram that has the -- same name as that of the enclosing generic package. The conflict -- occurs within an instance, between the subprogram and the renaming -- declaration for the package. After the subprogram, the package -- renaming declaration becomes hidden. if Ekind (E) = E_Package and then Present (Renamed_Object (E)) and then Renamed_Object (E) = Current_Scope and then Nkind (Parent (Renamed_Object (E))) = N_Package_Specification and then Present (Generic_Parent (Parent (Renamed_Object (E)))) then Set_Is_Hidden (E); Set_Is_Immediately_Visible (E, False); 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 -- dispatch table anyway, because it can be dispatched to even if it -- cannot be called directly. elsif Present (Alias (S)) and then not Comes_From_Source (S) then Set_Scope (S, Current_Scope); if Is_Dispatching_Operation (Alias (S)) then Check_Dispatching_Operation (S, Empty); end if; return; else Error_Msg_Sloc := Sloc (E); -- Generate message, with useful additional warning if in generic if Is_Generic_Unit (E) then 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; end if; -- E exists and is overloadable else Check_Synchronized_Overriding (S, Overridden_Subp); -- Loop through E and its homonyms to determine if any of them is -- the candidate for overriding by S. while Present (E) loop -- Definitely not interesting if not in the current scope if Scope (E) /= Current_Scope then null; -- Ada 2012 (AI05-0165): For internally generated bodies of -- null procedures locate the internally generated spec. We -- enforce mode conformance since a tagged type may inherit -- from interfaces several null primitives which differ only -- in the mode of the formals. elsif not Comes_From_Source (S) and then Is_Null_Procedure (S) and then not Mode_Conformant (E, S) then null; -- Check if we have type conformance elsif Type_Conformant (E, S) then -- If the old and new entities have the same profile and one -- is not the body of the other, then this is an error, unless -- one of them is implicitly declared. -- 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 inherited operation -- of a tagged full type overrides the inherited operation of -- a private extension. Ada 83 had a special rule for the -- literal case. In Ada 95, the later implicit operation hides -- the former, and the literal is always the former. In the -- odd case where both are derived operations declared at the -- same point, both operations should be declared, and in that -- case we bypass the following test and proceed to the next -- part. This can only occur for certain obscure cases in -- instances, when an operation on a type derived from a formal -- private type does not override a homograph inherited from -- the actual. In subsequent derivations of such a type, the -- DT positions of these operations remain distinct, if they -- have been set. if Present (Alias (S)) and then (No (Alias (E)) or else Comes_From_Source (E) or else Is_Abstract_Subprogram (S) or else (Is_Dispatching_Operation (E) and then Is_Overriding_Alias (E, S))) and then Ekind (E) /= E_Enumeration_Literal then -- When an derived operation is overloaded it may be due to -- the fact that the full view of a private extension -- re-inherits. It has to be dealt with. if Is_Package_Or_Generic_Package (Current_Scope) and then In_Private_Part (Current_Scope) then Check_Operation_From_Private_View (S, E); end if; -- In any case the implicit operation remains hidden by the -- existing declaration, which is overriding. 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; if Comes_From_Source (E) then Check_Overriding_Indicator (E, S, Is_Primitive => False); end if; return; -- Within an instance, the renaming declarations for actual -- subprograms may become ambiguous, but they do not hide each -- other. elsif Ekind (E) /= E_Entry and then not Comes_From_Source (E) and then not Is_Generic_Instance (E) and then (Present (Alias (E)) or else Is_Intrinsic_Subprogram (E)) and then (not In_Instance or else No (Parent (E)) or else Nkind (Unit_Declaration_Node (E)) /= N_Subprogram_Renaming_Declaration) then -- A subprogram child unit is not allowed to override an -- inherited subprogram (10.1.1(20)). if Is_Child_Unit (S) then Error_Msg_N ("child unit overrides inherited subprogram in parent", S); return; end if; if Is_Non_Overriding_Operation (E, S) then Enter_Overloaded_Entity (S); if No (Derived_Type) or else Is_Tagged_Type (Derived_Type) then Check_Dispatching_Operation (S, Empty); end if; return; end if; -- E is a derived operation or an internal operator which -- is being overridden. Remove E from further visibility. -- Furthermore, if E is a dispatching operation, it must be -- replaced in the list of primitive operations of its type -- (see Override_Dispatching_Operation). Overridden_Subp := E; declare Prev : Entity_Id; begin Prev := First_Entity (Current_Scope); while Present (Prev) and then Next_Entity (Prev) /= E loop Next_Entity (Prev); end loop; -- It is possible for E to be in the current scope and -- yet not in the entity chain. This can only occur in a -- generic context where E is an implicit concatenation -- in the formal part, because in a generic body the -- entity chain starts with the formals. pragma Assert (Present (Prev) or else Chars (E) = Name_Op_Concat); -- E must be removed both from the entity_list of the -- current scope, and from the visibility chain if Debug_Flag_E then Write_Str ("Override implicit operation "); Write_Int (Int (E)); Write_Eol; end if; -- If E is a predefined concatenation, it stands for four -- different operations. As a result, a single explicit -- declaration does not hide it. In a possible ambiguous -- situation, Disambiguate chooses the user-defined op, -- so it is correct to retain the previous internal one. if Chars (E) /= Name_Op_Concat or else Ekind (E) /= E_Operator then -- For nondispatching derived operations that are -- overridden by a subprogram declared in the private -- part of a package, we retain the derived subprogram -- but mark it as not immediately visible. If the -- derived operation was declared in the visible part -- then this ensures that it will still be visible -- outside the package with the proper signature -- (calls from outside must also be directed to this -- version rather than the overriding one, unlike the -- dispatching case). Calls from inside the package -- will still resolve to the overriding subprogram -- since the derived one is marked as not visible -- within the package. -- If the private operation is dispatching, we achieve -- the overriding by keeping the implicit operation -- 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. -- If the overriding is not in the private part, we -- remove the implicit operation altogether. if Is_Private_Declaration (S) then if not Is_Dispatching_Operation (E) then Set_Is_Immediately_Visible (E, False); else -- Work done in Override_Dispatching_Operation, -- so nothing else needs to be done here. null; end if; else -- Find predecessor of E in Homonym chain if E = Current_Entity (E) then Prev_Vis := Empty; else Prev_Vis := Current_Entity (E); while Homonym (Prev_Vis) /= E loop Prev_Vis := Homonym (Prev_Vis); end loop; end if; if Prev_Vis /= Empty then -- Skip E in the visibility chain Set_Homonym (Prev_Vis, Homonym (E)); else Set_Name_Entity_Id (Chars (E), Homonym (E)); end if; Set_Next_Entity (Prev, Next_Entity (E)); if No (Next_Entity (Prev)) then Set_Last_Entity (Current_Scope, Prev); end if; end if; end if; Enter_Overloaded_Entity (S); -- For entities generated by Derive_Subprograms the -- overridden operation is the inherited primitive -- (which is available through the attribute alias). if not (Comes_From_Source (E)) and then Is_Dispatching_Operation (E) and then Find_Dispatching_Type (E) = Find_Dispatching_Type (S) and then Present (Alias (E)) and then Comes_From_Source (Alias (E)) then Set_Overridden_Operation (S, Alias (E)); -- Normal case of setting entity as overridden -- Note: Static_Initialization and Overridden_Operation -- attributes use the same field in subprogram entities. -- Static_Initialization is only defined for internal -- initialization procedures, where Overridden_Operation -- is irrelevant. Therefore the setting of this attribute -- must check whether the target is an init_proc. elsif not Is_Init_Proc (S) then Set_Overridden_Operation (S, E); end if; Check_Overriding_Indicator (S, E, Is_Primitive => True); -- If S is a user-defined subprogram or a null procedure -- expanded to override an inherited null procedure, or a -- predefined dispatching primitive then indicate that E -- overrides the operation from which S is inherited. if Comes_From_Source (S) or else (Present (Parent (S)) and then Nkind (Parent (S)) = N_Procedure_Specification and then Null_Present (Parent (S))) or else (Present (Alias (E)) and then Is_Predefined_Dispatching_Operation (Alias (E))) then if Present (Alias (E)) then Set_Overridden_Operation (S, Alias (E)); end if; end if; if Is_Dispatching_Operation (E) then -- An overriding dispatching subprogram inherits the -- convention of the overridden subprogram (AI-117). Set_Convention (S, Convention (E)); Check_Dispatching_Operation (S, E); else Check_Dispatching_Operation (S, Empty); end if; Check_For_Primitive_Subprogram (Is_Primitive_Subp, Is_Overriding => True); goto Check_Inequality; end; -- Apparent redeclarations in instances can occur when two -- formal types get the same actual type. The subprograms in -- in the instance are legal, even if not callable from the -- outside. Calls from within are disambiguated elsewhere. -- For dispatching operations in the visible part, the usual -- rules apply, and operations with the same profile are not -- legal (B830001). elsif (In_Instance_Visible_Part and then not Is_Dispatching_Operation (E)) or else In_Instance_Not_Visible then null; -- Here we have a real error (identical profile) else Error_Msg_Sloc := Sloc (E); -- Avoid cascaded errors if the entity appears in -- subsequent calls. Set_Scope (S, Current_Scope); -- 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&", S); Error_Msg_N ("\& conflicts with declaration#", S); else Error_Msg_N ("& conflicts with declaration#", S); end if; return; end if; else -- 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; E := Homonym (E); end loop; -- On exit, we know that S is a new entity Enter_Overloaded_Entity (S); Check_For_Primitive_Subprogram (Is_Primitive_Subp); Check_Overriding_Indicator (S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp); -- Overloading is not allowed in SPARK, except for operators if Nkind (S) /= N_Defining_Operator_Symbol then Error_Msg_Sloc := Sloc (Homonym (S)); Check_SPARK_Restriction ("overloading not allowed with entity#", S); end if; -- 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 Check_Dispatching_Operation is not -- called in that case. if No (Derived_Type) or else Is_Tagged_Type (Derived_Type) then Check_Dispatching_Operation (S, Empty); end if; end if; -- If this is a user-defined equality operator that is not a derived -- subprogram, create the corresponding inequality. If the operation is -- dispatching, the expansion is done elsewhere, and we do not create -- an explicit inequality operation. <<Check_Inequality>> if Chars (S) = Name_Op_Eq and then Etype (S) = Standard_Boolean and then Present (Parent (S)) and then not Is_Dispatching_Operation (S) then Make_Inequality_Operator (S); if Ada_Version >= Ada_2012 then Check_Untagged_Equality (S); end if; end if; end New_Overloaded_Entity; --------------------- -- Process_Formals -- --------------------- procedure Process_Formals (T : List_Id; Related_Nod : Node_Id) is Param_Spec : Node_Id; Formal : Entity_Id; Formal_Type : Entity_Id; 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 Designates_From_With_Type (Typ : Entity_Id) return Boolean; -- Determine whether an access type designates a type coming from a -- limited view. 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 -- for an access attribute. ------------------------------- -- Designates_From_With_Type -- ------------------------------- function Designates_From_With_Type (Typ : Entity_Id) return Boolean is Desig : Entity_Id := Typ; begin if Is_Access_Type (Desig) then Desig := Directly_Designated_Type (Desig); end if; if Is_Class_Wide_Type (Desig) then Desig := Root_Type (Desig); end if; return Ekind (Desig) = E_Incomplete_Type and then From_With_Type (Desig); end Designates_From_With_Type; --------------------------- -- Is_Class_Wide_Default -- --------------------------- function Is_Class_Wide_Default (D : Node_Id) return Boolean is begin return Is_Class_Wide_Type (Designated_Type (Etype (D))) or else (Nkind (D) = N_Attribute_Reference and then Attribute_Name (D) = Name_Access and then Is_Class_Wide_Type (Etype (Prefix (D)))); end Is_Class_Wide_Default; -- Start of processing for Process_Formals begin -- In order to prevent premature use of the formals in the same formal -- part, the Ekind is left undefined until all default expressions are -- 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 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then Find_Type (Parameter_Type (Param_Spec)); Ptype := Parameter_Type (Param_Spec); if Ptype = Error then goto Continue; end if; Formal_Type := Entity (Ptype); 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-326): Tagged incomplete types allowed in -- primitive operations, as long as their completion is -- in the same declarative part. If in the private part -- this means that the type cannot be a Taft-amendment type. -- Check is done on package exit. For access to subprograms, -- the use is legal for Taft-amendment types. if Is_Tagged_Type (Formal_Type) then if Ekind (Scope (Current_Scope)) = E_Package and then not From_With_Type (Formal_Type) and then not Is_Class_Wide_Type (Formal_Type) then if not Nkind_In (Parent (T), N_Access_Function_Definition, N_Access_Procedure_Definition) then Append_Elmt (Current_Scope, Private_Dependents (Base_Type (Formal_Type))); -- Freezing is delayed to ensure that Register_Prim -- will get called for this operation, which is needed -- in cases where static dispatch tables aren't built. -- (Note that the same is done for controlling access -- parameter cases in function Access_Definition.) Set_Has_Delayed_Freeze (Current_Scope); end if; end if; -- 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 -- AI05-0151: Tagged incomplete types are allowed in all -- formal parts. Untagged incomplete types are not allowed -- in bodies. if Ada_Version >= Ada_2012 then if Is_Tagged_Type (Formal_Type) then null; elsif Nkind_In (Parent (Parent (T)), N_Accept_Statement, N_Entry_Body, N_Subprogram_Body) then Error_Msg_NE ("invalid use of untagged incomplete type&", Ptype, Formal_Type); end if; else Error_Msg_NE ("invalid use of incomplete type&", Param_Spec, Formal_Type); -- Further checks on the legality of incomplete types -- in formal parts are delayed until the freeze point -- of the enclosing subprogram or access to subprogram. end if; end if; elsif Ekind (Formal_Type) = E_Void then Error_Msg_NE ("premature use of&", Parameter_Type (Param_Spec), Formal_Type); end if; -- Ada 2012 (AI-142): Handle aliased parameters if Ada_Version >= Ada_2012 and then Aliased_Present (Param_Spec) then Set_Is_Aliased (Formal); end if; -- Ada 2005 (AI-231): Create and decorate an internal subtype -- declaration corresponding to the null-excluding type of the -- formal in the enclosing scope. Finally, replace the parameter -- type of the formal with the internal subtype. if Ada_Version >= Ada_2005 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); 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; Formal_Type := Create_Null_Excluding_Itype (T => Formal_Type, Related_Nod => Related_Nod, Scope_Id => Scope (Current_Scope)); -- 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. -- Example: -- type T is access procedure; -- procedure Op (O : not null T); 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 else 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 AD : constant Node_Id := Access_To_Subprogram_Definition (Parameter_Type (Param_Spec)); begin if Present (AD) and then Protected_Present (AD) then Formal_Type := Replace_Anonymous_Access_To_Protected_Subprogram (Param_Spec); end if; end; end if; Set_Etype (Formal, Formal_Type); -- Deal with default expression if present Default := Expression (Param_Spec); if Present (Default) then Check_SPARK_Restriction ("default expression is not allowed", Default); if Out_Present (Param_Spec) then Error_Msg_N ("default initialization only allowed for IN parameters", Param_Spec); end if; -- Do the special preanalysis of the expression (see section on -- "Handling of Default Expressions" in the spec of package Sem). 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. if Ekind (Formal_Type) = E_Anonymous_Access_Type and then not Designates_From_With_Type (Formal_Type) and then Is_Class_Wide_Default (Default) and then not Is_Class_Wide_Type (Designated_Type (Formal_Type)) then Error_Msg_N ("access to class-wide expression not allowed here", Default); end if; -- Check incorrect use of dynamically tagged expressions if Is_Tagged_Type (Formal_Type) then Check_Dynamically_Tagged_Expression (Expr => Default, Typ => Formal_Type, Related_Nod => Default); end if; end if; -- Ada 2005 (AI-231): Static checks if Ada_Version >= Ada_2005 and then Is_Access_Type (Etype (Formal)) and then Can_Never_Be_Null (Etype (Formal)) then Null_Exclusion_Static_Checks (Param_Spec); end if; <<Continue>> Next (Param_Spec); end loop; -- If this is the formal part of a function specification, analyze the -- subtype mark in the context where the formals are visible but not -- yet usable, and may hide outer homographs. if Nkind (Related_Nod) = N_Function_Specification then Analyze_Return_Type (Related_Nod); end if; -- Now set the kind (mode) of each formal Param_Spec := First (T); while Present (Param_Spec) loop Formal := Defining_Identifier (Param_Spec); Set_Formal_Mode (Formal); if Ekind (Formal) = E_In_Parameter then Set_Default_Value (Formal, Expression (Param_Spec)); if Present (Expression (Param_Spec)) then Default := Expression (Param_Spec); if Is_Scalar_Type (Etype (Default)) then if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then Formal_Type := Entity (Parameter_Type (Param_Spec)); else Formal_Type := Access_Definition (Related_Nod, Parameter_Type (Param_Spec)); end if; 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; -- Skip remaining processing if formal type was in error if Etype (Formal) = Any_Type or else Error_Posted (Formal) then goto Next_Parameter; end if; -- Force call by reference if aliased if Is_Aliased (Formal) then Set_Mechanism (Formal, By_Reference); -- Warn if user asked this to be passed by copy if Convention (Formal_Type) = Convention_Ada_Pass_By_Copy then Error_Msg_N ("?cannot pass aliased parameter & by copy", Formal); end if; -- Force mechanism if type has Convention Ada_Pass_By_Ref/Copy elsif Convention (Formal_Type) = Convention_Ada_Pass_By_Copy then Set_Mechanism (Formal, By_Copy); elsif Convention (Formal_Type) = Convention_Ada_Pass_By_Reference then Set_Mechanism (Formal, By_Reference); end if; <<Next_Parameter>> 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; Parms : List_Id; Designator : Entity_Id; -- Subprogram designator, set from Spec_Id if present, else Body_Id Precond : Node_Id := Empty; -- Set non-Empty if we prepend precondition to the declarations. This -- is used to hook up inherited preconditions (adding the condition -- expression with OR ELSE, and adding the message). Inherited_Precond : Node_Id; -- Precondition inherited from parent subprogram Inherited : constant Subprogram_List := Inherited_Subprograms (Spec_Id); -- List of subprograms inherited by this subprogram Plist : List_Id := No_List; -- List of generated postconditions function Grab_PPC (Pspec : Entity_Id := Empty) 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. If Pspec is non- -- empty, this is the case of inheriting a PPC, where we must change -- references to parameters of the inherited subprogram to point to the -- corresponding parameters of the current subprogram. function Invariants_Or_Predicates_Present return Boolean; -- Determines if any invariants or predicates are present for any OUT -- or IN OUT parameters of the subprogram, or (for a function) if the -- return value has an invariant. function Is_Public_Subprogram_For (T : Entity_Id) return Boolean; -- T is the entity for a private type for which invariants are defined. -- This function returns True if the procedure corresponding to the -- value of Designator is a public procedure from the point of view of -- this type (i.e. its spec is in the visible part of the package that -- contains the declaration of the private type). A True value means -- that an invariant check is required (for an IN OUT parameter, or -- the returned value of a function. -------------- -- Grab_PPC -- -------------- function Grab_PPC (Pspec : Entity_Id := Empty) return Node_Id is Nam : constant Name_Id := Pragma_Name (Prag); Map : Elist_Id; CP : Node_Id; begin -- Prepare map if this is the case where we have to map entities of -- arguments in the overridden subprogram to corresponding entities -- of the current subprogram. if No (Pspec) then Map := No_Elist; else declare PF : Entity_Id; CF : Entity_Id; begin Map := New_Elmt_List; PF := First_Formal (Pspec); CF := First_Formal (Designator); while Present (PF) loop Append_Elmt (PF, Map); Append_Elmt (CF, Map); Next_Formal (PF); Next_Formal (CF); end loop; end; end if; -- Now we can copy the tree, doing any required substitutions CP := New_Copy_Tree (Prag, Map => Map, New_Scope => Current_Scope); -- 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); -- We also make sure Comes_From_Source is False for the copy Set_Comes_From_Source (CP, False); -- For a postcondition pragma within a generic, preserve the pragma -- for later expansion. if Nam = Name_Postcondition and then not Expander_Active then return CP; end if; -- Change copy of pragma into corresponding pragma Check Prepend_To (Pragma_Argument_Associations (CP), Make_Pragma_Argument_Association (Sloc (Prag), Expression => Make_Identifier (Loc, Nam))); Set_Pragma_Identifier (CP, Make_Identifier (Sloc (Prag), Name_Check)); -- If this is inherited case and the current message starts with -- "failed p", we change it to "failed inherited p...". if Present (Pspec) then declare Msg : constant Node_Id := Last (Pragma_Argument_Associations (CP)); begin if Chars (Msg) = Name_Message then String_To_Name_Buffer (Strval (Expression (Msg))); if Name_Buffer (1 .. 8) = "failed p" then Insert_Str_In_Name_Buffer ("inherited ", 8); Set_Strval (Expression (Last (Pragma_Argument_Associations (CP))), String_From_Name_Buffer); end if; end if; end; end if; -- Return the check pragma return CP; end Grab_PPC; -------------------------------------- -- Invariants_Or_Predicates_Present -- -------------------------------------- function Invariants_Or_Predicates_Present return Boolean is Formal : Entity_Id; begin -- Check function return result if Ekind (Designator) /= E_Procedure and then Has_Invariants (Etype (Designator)) then return True; end if; -- Check parameters Formal := First_Formal (Designator); while Present (Formal) loop if Ekind (Formal) /= E_In_Parameter and then (Has_Invariants (Etype (Formal)) or else Present (Predicate_Function (Etype (Formal)))) then return True; end if; Next_Formal (Formal); end loop; return False; end Invariants_Or_Predicates_Present; ------------------------------ -- Is_Public_Subprogram_For -- ------------------------------ -- The type T is a private type, its declaration is therefore in -- the list of public declarations of some package. The test for a -- public subprogram is that its declaration is in this same list -- of declarations for the same package (note that all the public -- declarations are in one list, and all the private declarations -- in another, so this deals with the public/private distinction). function Is_Public_Subprogram_For (T : Entity_Id) return Boolean is DD : constant Node_Id := Unit_Declaration_Node (Designator); -- The subprogram declaration for the subprogram in question TL : constant List_Id := Visible_Declarations (Specification (Unit_Declaration_Node (Scope (T)))); -- The list of declarations containing the private declaration of -- the type. We know it is a private type, so we know its scope is -- the package in question, and we know it must be in the visible -- declarations of this package. begin -- If the subprogram declaration is not a list member, it must be -- an Init_Proc, in which case we want to consider it to be a -- public subprogram, since we do get initializations to deal with. if not Is_List_Member (DD) then return True; -- Otherwise we test whether the subprogram is declared in the -- visible declarations of the package containing the type. else return TL = List_Containing (DD); end if; end Is_Public_Subprogram_For; -- Start of processing for Process_PPCs begin -- Capture designator from spec if present, else from body if Present (Spec_Id) then Designator := Spec_Id; else Designator := Body_Id; end if; -- 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 (Contract (Spec_Id)); while Present (Prag) loop if Pragma_Name (Prag) = Name_Precondition then -- For Pre (or Precondition pragma), we simply prepend the -- pragma to the list of declarations right away so that it -- will be executed at the start of the procedure. 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. There can be more than one precondition when we -- use pragma Precondition. if not Class_Present (Prag) then Prepend (Grab_PPC, Declarations (N)); -- For Pre'Class there can only be one pragma, and we save -- it in Precond for now. We will add inherited Pre'Class -- stuff before inserting this pragma in the declarations. else Precond := Grab_PPC; end if; end if; Prag := Next_Pragma (Prag); end loop; -- Now deal with inherited preconditions for J in Inherited'Range loop Prag := Spec_PPC_List (Contract (Inherited (J))); while Present (Prag) loop if Pragma_Name (Prag) = Name_Precondition and then Class_Present (Prag) then Inherited_Precond := Grab_PPC (Inherited (J)); -- No precondition so far, so establish this as the first if No (Precond) then Precond := Inherited_Precond; -- Here we already have a precondition, add inherited one else -- Add new precondition to old one using OR ELSE declare New_Expr : constant Node_Id := Get_Pragma_Arg (Next (First (Pragma_Argument_Associations (Inherited_Precond)))); Old_Expr : constant Node_Id := Get_Pragma_Arg (Next (First (Pragma_Argument_Associations (Precond)))); begin if Paren_Count (Old_Expr) = 0 then Set_Paren_Count (Old_Expr, 1); end if; if Paren_Count (New_Expr) = 0 then Set_Paren_Count (New_Expr, 1); end if; Rewrite (Old_Expr, Make_Or_Else (Sloc (Old_Expr), Left_Opnd => Relocate_Node (Old_Expr), Right_Opnd => New_Expr)); end; -- Add new message in the form: -- failed precondition from bla -- also failed inherited precondition from bla -- ... -- Skip this if exception locations are suppressed if not Exception_Locations_Suppressed then declare New_Msg : constant Node_Id := Get_Pragma_Arg (Last (Pragma_Argument_Associations (Inherited_Precond))); Old_Msg : constant Node_Id := Get_Pragma_Arg (Last (Pragma_Argument_Associations (Precond))); begin Start_String (Strval (Old_Msg)); Store_String_Chars (ASCII.LF & " also "); Store_String_Chars (Strval (New_Msg)); Set_Strval (Old_Msg, End_String); end; end if; end if; end if; Prag := Next_Pragma (Prag); end loop; end loop; -- If we have built a precondition for Pre'Class (including any -- Pre'Class aspects inherited from parent subprograms), then we -- insert this composite precondition at this stage. if Present (Precond) then Prepend (Precond, Declarations (N)); end if; 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]); -- ... -- Invariant_Procedure (_Result) ... -- Invariant_Procedure (Arg1) -- ... -- 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); -- If expansion is disabled, as in a generic unit, save -- pragma for later expansion. if not Expander_Active then Prepend (Grab_PPC, Declarations (N)); else Append (Grab_PPC, Plist); end if; 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 Spec_Postconditions : declare procedure Process_Post_Conditions (Spec : Node_Id; Class : Boolean); -- This processes the Spec_PPC_List from Spec, processing any -- postconditions from the list. If Class is True, then only -- postconditions marked with Class_Present are considered. -- The caller has checked that Spec_PPC_List is non-Empty. ----------------------------- -- Process_Post_Conditions -- ----------------------------- procedure Process_Post_Conditions (Spec : Node_Id; Class : Boolean) is Pspec : Node_Id; begin if Class then Pspec := Spec; else Pspec := Empty; end if; -- Loop through PPC pragmas from spec Prag := Spec_PPC_List (Contract (Spec)); loop if Pragma_Name (Prag) = Name_Postcondition and then (not Class or else Class_Present (Prag)) then if Plist = No_List then Plist := Empty_List; end if; if not Expander_Active then Prepend (Grab_PPC (Pspec), Declarations (N)); else Append (Grab_PPC (Pspec), Plist); end if; end if; Prag := Next_Pragma (Prag); exit when No (Prag); end loop; end Process_Post_Conditions; -- Start of processing for Spec_Postconditions begin if Present (Spec_PPC_List (Contract (Spec_Id))) then Process_Post_Conditions (Spec_Id, Class => False); end if; -- Process inherited postconditions for J in Inherited'Range loop if Present (Spec_PPC_List (Contract (Inherited (J)))) then Process_Post_Conditions (Inherited (J), Class => True); end if; end loop; end Spec_Postconditions; end if; -- If we had any postconditions and expansion is enabled, or if the -- procedure has invariants, then build the _Postconditions procedure. if (Present (Plist) or else Invariants_Or_Predicates_Present) and then Expander_Active then if No (Plist) then Plist := Empty_List; end if; -- Special processing for function case if Ekind (Designator) /= E_Procedure then declare Rent : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uResult); Ftyp : constant Entity_Id := Etype (Designator); begin Set_Etype (Rent, Ftyp); -- Add argument for return Parms := New_List ( Make_Parameter_Specification (Loc, Parameter_Type => New_Occurrence_Of (Ftyp, Loc), Defining_Identifier => Rent)); -- Add invariant call if returning type with invariants and -- this is a public function, i.e. a function declared in the -- visible part of the package defining the private type. if Has_Invariants (Etype (Rent)) and then Present (Invariant_Procedure (Etype (Rent))) and then Is_Public_Subprogram_For (Etype (Rent)) then Append_To (Plist, Make_Invariant_Call (New_Occurrence_Of (Rent, Loc))); end if; end; -- Procedure rather than a function else Parms := No_List; end if; -- Add invariant calls and predicate calls for parameters. Note that -- this is done for functions as well, since in Ada 2012 they can -- have IN OUT args. declare Formal : Entity_Id; Ftype : Entity_Id; begin Formal := First_Formal (Designator); while Present (Formal) loop if Ekind (Formal) /= E_In_Parameter then Ftype := Etype (Formal); if Has_Invariants (Ftype) and then Present (Invariant_Procedure (Ftype)) and then Is_Public_Subprogram_For (Ftype) then Append_To (Plist, Make_Invariant_Call (New_Occurrence_Of (Formal, Loc))); end if; if Present (Predicate_Function (Ftype)) then Append_To (Plist, Make_Predicate_Check (Ftype, New_Occurrence_Of (Formal, Loc))); end if; end if; Next_Formal (Formal); end loop; end; -- Build and insert postcondition procedure declare Post_Proc : constant Entity_Id := Make_Defining_Identifier (Loc, Chars => Name_uPostconditions); -- The entity for the _Postconditions procedure begin Prepend_To (Declarations (N), Make_Subprogram_Body (Loc, Specification => Make_Procedure_Specification (Loc, Defining_Unit_Name => Post_Proc, Parameter_Specifications => Parms), Declarations => Empty_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => Plist))); Set_Ekind (Post_Proc, E_Procedure); -- If this is a procedure, set the Postcondition_Proc attribute on -- the proper defining entity for the subprogram. if Ekind (Designator) = E_Procedure then Set_Postcondition_Proc (Designator, Post_Proc); end if; end; Set_Has_Postconditions (Designator); end if; end Process_PPCs; ---------------------------- -- Reference_Body_Formals -- ---------------------------- procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id) is Fs : Entity_Id; Fb : Entity_Id; begin if Error_Posted (Spec) then 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) and then Present (Fb) loop Generate_Reference (Fs, Fb, 'b'); if Style_Check then Style.Check_Identifier (Fb, Fs); end if; Set_Spec_Entity (Fb, Fs); Set_Referenced (Fs, False); Next_Formal (Fs); Next_Formal (Fb); end loop; end Reference_Body_Formals; ------------------------- -- Set_Actual_Subtypes -- ------------------------- procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is Decl : Node_Id; Formal : Entity_Id; T : Entity_Id; First_Stmt : Node_Id := Empty; AS_Needed : Boolean; begin -- If this is an empty initialization procedure, no need to create -- actual subtypes (small optimization). if Ekind (Subp) = E_Procedure and then Is_Null_Init_Proc (Subp) then return; end if; Formal := First_Formal (Subp); while Present (Formal) loop T := Etype (Formal); -- We never need an actual subtype for a constrained formal if Is_Constrained (T) then AS_Needed := False; -- If we have unknown discriminants, then we do not need an actual -- subtype, or more accurately we cannot figure it out! Note that -- all class-wide types have unknown discriminants. elsif Has_Unknown_Discriminants (T) then AS_Needed := False; -- At this stage we have an unconstrained type that may need an -- actual subtype. For sure the actual subtype is needed if we have -- an unconstrained array type. elsif Is_Array_Type (T) then AS_Needed := True; -- 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 and then Chars (Formal) /= Name_uInit and then not Is_Unchecked_Union (T) and then not Is_Discrim_SO_Function (Subp) then AS_Needed := True; -- All other cases do not need an actual subtype else AS_Needed := False; end if; -- Generate actual subtypes for unconstrained arrays and -- unconstrained discriminated records. if AS_Needed then if Nkind (N) = N_Accept_Statement then -- If expansion is active, the formal is replaced by a local -- variable that renames the corresponding entry of the -- parameter block, and it is this local variable that may -- require an actual subtype. if Full_Expander_Active then Decl := Build_Actual_Subtype (T, Renamed_Object (Formal)); else Decl := Build_Actual_Subtype (T, Formal); end if; if Present (Handled_Statement_Sequence (N)) then First_Stmt := First (Statements (Handled_Statement_Sequence (N))); Prepend (Decl, Statements (Handled_Statement_Sequence (N))); Mark_Rewrite_Insertion (Decl); else -- If the accept statement has no body, there will be no -- reference to the actuals, so no need to compute actual -- subtypes. return; end if; else Decl := Build_Actual_Subtype (T, Formal); Prepend (Decl, Declarations (N)); Mark_Rewrite_Insertion (Decl); end if; -- The declaration uses the bounds of an existing object, and -- therefore needs no constraint checks. Analyze (Decl, Suppress => All_Checks); -- We need to freeze manually the generated type when it is -- inserted anywhere else than in a declarative part. if Present (First_Stmt) then Insert_List_Before_And_Analyze (First_Stmt, Freeze_Entity (Defining_Identifier (Decl), N)); end if; if Nkind (N) = N_Accept_Statement and then Full_Expander_Active then Set_Actual_Subtype (Renamed_Object (Formal), Defining_Identifier (Decl)); else Set_Actual_Subtype (Formal, Defining_Identifier (Decl)); end if; end if; Next_Formal (Formal); end loop; end Set_Actual_Subtypes; --------------------- -- Set_Formal_Mode -- --------------------- procedure Set_Formal_Mode (Formal_Id : Entity_Id) is Spec : constant Node_Id := Parent (Formal_Id); begin -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters -- since we ensure that corresponding actuals are always valid at the -- point of the call. if Out_Present (Spec) then if Ekind (Scope (Formal_Id)) = E_Function or else Ekind (Scope (Formal_Id)) = E_Generic_Function then -- [IN] OUT parameters allowed for functions in Ada 2012 if Ada_Version >= Ada_2012 then if In_Present (Spec) then Set_Ekind (Formal_Id, E_In_Out_Parameter); else Set_Ekind (Formal_Id, E_Out_Parameter); end if; -- But not in earlier versions of Ada else Error_Msg_N ("functions can only have IN parameters", Spec); Set_Ekind (Formal_Id, E_In_Parameter); end if; elsif In_Present (Spec) then Set_Ekind (Formal_Id, E_In_Out_Parameter); else Set_Ekind (Formal_Id, E_Out_Parameter); Set_Never_Set_In_Source (Formal_Id, True); Set_Is_True_Constant (Formal_Id, False); Set_Current_Value (Formal_Id, Empty); end if; else Set_Ekind (Formal_Id, E_In_Parameter); end if; -- Set Is_Known_Non_Null for access parameters since the language -- guarantees that access parameters are always non-null. We also set -- Can_Never_Be_Null, since there is no way to change the value. if Nkind (Parameter_Type (Spec)) = N_Access_Definition then -- Ada 2005 (AI-231): In Ada 95, access parameters are always non- -- null; In Ada 2005, only if then null_exclusion is explicit. if Ada_Version < Ada_2005 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); -- We can also set Can_Never_Be_Null (thus preventing some junk -- access checks) for the case of an IN parameter, which cannot -- be changed, or for an IN OUT parameter, which can be changed but -- not to a null value. But for an OUT parameter, the initial value -- passed in can be null, so we can't set this flag in that case. if Ekind (Formal_Id) /= E_Out_Parameter then Set_Can_Never_Be_Null (Formal_Id); end if; end if; Set_Mechanism (Formal_Id, Default_Mechanism); Set_Formal_Validity (Formal_Id); end Set_Formal_Mode; ------------------------- -- Set_Formal_Validity -- ------------------------- procedure Set_Formal_Validity (Formal_Id : Entity_Id) is begin -- If no validity checking, then we cannot assume anything about the -- validity of parameters, since we do not know there is any checking -- of the validity on the call side. if not Validity_Checks_On then return; -- If validity checking for parameters is enabled, this means we are -- not supposed to make any assumptions about argument values. elsif Validity_Check_Parameters then return; -- If we are checking in parameters, we will assume that the caller is -- also checking parameters, so we can assume the parameter is valid. elsif Ekind (Formal_Id) = E_In_Parameter and then Validity_Check_In_Params then Set_Is_Known_Valid (Formal_Id, True); -- Similar treatment for IN OUT parameters elsif Ekind (Formal_Id) = E_In_Out_Parameter and then Validity_Check_In_Out_Params then Set_Is_Known_Valid (Formal_Id, True); end if; end Set_Formal_Validity; ------------------------ -- Subtype_Conformant -- ------------------------ function Subtype_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, Subtype_Conformant, False, Result, Skip_Controlling_Formals => Skip_Controlling_Formals); return Result; end Subtype_Conformant; --------------------- -- Type_Conformant -- --------------------- function Type_Conformant (New_Id : Entity_Id; Old_Id : Entity_Id; Skip_Controlling_Formals : Boolean := False) return Boolean is Result : Boolean; begin 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; ------------------------------- -- Valid_Operator_Definition -- ------------------------------- procedure Valid_Operator_Definition (Designator : Entity_Id) is N : Integer := 0; F : Entity_Id; Id : constant Name_Id := Chars (Designator); N_OK : Boolean; begin F := First_Formal (Designator); while Present (F) loop N := N + 1; if Present (Default_Value (F)) then Error_Msg_N ("default values not allowed for operator parameters", Parent (F)); end if; Next_Formal (F); end loop; -- Verify that user-defined operators have proper number of arguments -- First case of operators which can only be unary if Id = Name_Op_Not or else Id = Name_Op_Abs then N_OK := (N = 1); -- Case of operators which can be unary or binary elsif Id = Name_Op_Add or Id = Name_Op_Subtract then N_OK := (N in 1 .. 2); -- All other operators can only be binary else N_OK := (N = 2); end if; if not N_OK then Error_Msg_N ("incorrect number of arguments for operator", Designator); end if; if Id = Name_Op_Ne and then Base_Type (Etype (Designator)) = Standard_Boolean and then not Is_Intrinsic_Subprogram (Designator) then Error_Msg_N ("explicit definition of inequality not allowed", Designator); end if; end Valid_Operator_Definition; end Sem_Ch6;
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