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Diffstat (limited to 'gcc-4.2.1/gcc/ada/sem_ch6.adb')
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diff --git a/gcc-4.2.1/gcc/ada/sem_ch6.adb b/gcc-4.2.1/gcc/ada/sem_ch6.adb deleted file mode 100644 index 33696df52..000000000 --- a/gcc-4.2.1/gcc/ada/sem_ch6.adb +++ /dev/null @@ -1,6207 +0,0 @@ ------------------------------------------------------------------------------- --- -- --- GNAT COMPILER COMPONENTS -- --- -- --- S E M _ C H 6 -- --- -- --- B o d y -- --- -- --- Copyright (C) 1992-2006, Free Software Foundation, Inc. -- --- -- --- GNAT is free software; you can redistribute it and/or modify it under -- --- terms of the GNU General Public License as published by the Free Soft- -- --- ware Foundation; either version 2, or (at your option) any later ver- -- --- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- --- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- --- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- --- for more details. You should have received a copy of the GNU General -- --- Public License distributed with GNAT; see file COPYING. If not, write -- --- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- --- Boston, MA 02110-1301, USA. -- --- -- --- 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_Ch7; use Exp_Ch7; -with Exp_Tss; use Exp_Tss; -with Fname; use Fname; -with Freeze; use Freeze; -with Itypes; use Itypes; -with Lib.Xref; use Lib.Xref; -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 Rtsfind; use Rtsfind; -with Sem; use Sem; -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_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 Tbuild; use Tbuild; -with Uintp; use Uintp; -with Urealp; use Urealp; -with Validsw; use Validsw; - -package body Sem_Ch6 is - - -- The following 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. - - May_Hide_Profile : Boolean := False; - - ----------------------- - -- Local Subprograms -- - ----------------------- - - 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_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 - -- subsequenty 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. - - type Conformance_Type is - (Type_Conformant, Mode_Conformant, Subtype_Conformant, Fully_Conformant); - -- Conformance type used for following call, meaning matches the - -- RM definitions of the corresponding terms. - - procedure Check_Conformance - (New_Id : Entity_Id; - Old_Id : Entity_Id; - Ctype : Conformance_Type; - Errmsg : Boolean; - Conforms : out Boolean; - Err_Loc : Node_Id := Empty; - Get_Inst : Boolean := False; - 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_Overriding_Indicator - (Subp : Entity_Id; - Does_Override : Boolean); - -- Verify the consistency of an overriding_indicator given for subprogram - -- declaration, body, renaming, or instantiation. The flag Does_Override - -- is set if the scope into which we are introducing the subprogram - -- contains a type-conformant subprogram that becomes hidden by the new - -- subprogram. - - 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. L is the - -- handled statement sequence for the subprogram body. This procedure - -- checks all flow paths to make sure they either have return (Mode = 'F', - -- 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. - - function Conforming_Types - (T1 : Entity_Id; - T2 : Entity_Id; - Ctype : Conformance_Type; - Get_Inst : Boolean := False) return Boolean; - -- Check that two formal parameter types conform, checking both for - -- equality of base types, and where required statically matching - -- subtypes, depending on the setting of Ctype. - - procedure Enter_Overloaded_Entity (S : Entity_Id); - -- This procedure makes S, a new overloaded entity, into the first visible - -- entity with that name. - - procedure Install_Entity (E : Entity_Id); - -- Make single entity visible. Used for generic formals as well - - procedure Install_Formals (Id : Entity_Id); - -- On entry to a subprogram body, make the formals visible. Note that - -- simply placing the subprogram on the scope stack is not sufficient: - -- the formals must become the current entities for their names. - - function Is_Non_Overriding_Operation - (Prev_E : Entity_Id; - New_E : Entity_Id) return Boolean; - -- 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 can happen 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 Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id); - -- If there is a separate spec for a subprogram or generic subprogram, the - -- formals of the body are treated as references to the corresponding - -- formals of the spec. This reference does not count as an actual use of - -- the formal, in order to diagnose formals that are unused in the body. - - procedure 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 - Generate_Definition (Designator); - Set_Is_Abstract (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); - end if; - - Generate_Reference_To_Formals (Designator); - end Analyze_Abstract_Subprogram_Declaration; - - ---------------------------- - -- Analyze_Function_Call -- - ---------------------------- - - procedure Analyze_Function_Call (N : Node_Id) is - P : constant Node_Id := Name (N); - L : constant List_Id := Parameter_Associations (N); - Actual : Node_Id; - - begin - Analyze (P); - - -- A call of the form A.B (X) may be an Ada05 call, which is rewritten - -- as B (A, X). If the rewriting is successful, the call has been - -- 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 (L) then - Actual := First (L); - while Present (Actual) loop - Analyze (Actual); - Check_Parameterless_Call (Actual); - Next (Actual); - end loop; - end if; - - Analyze_Call (N); - end Analyze_Function_Call; - - ------------------------------------- - -- 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. - - New_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_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); - - Set_Actual_Subtypes (N, Current_Scope); - 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); - Style.Check_Identifier (Body_Id, Gen_Id); - 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 - - ------------------------------ - -- 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); - 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 defererence) - -- 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 error analyzing prefix, then set Any_Type as result 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; - - -- Special processing for Elab_Spec and Elab_Body calls - - if Nkind (P) = N_Attribute_Reference - and then (Attribute_Name (P) = Name_Elab_Spec - or else Attribute_Name (P) = Name_Elab_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; - - -- 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 - Loc : constant Source_Ptr := Sloc (N); - Expr : Node_Id; - Scope_Id : Entity_Id; - Kind : Entity_Kind; - R_Type : Entity_Id; - - begin - -- Find subprogram or accept statement enclosing the return statement - - Scope_Id := Empty; - for J in reverse 0 .. Scope_Stack.Last loop - Scope_Id := Scope_Stack.Table (J).Entity; - exit when Ekind (Scope_Id) /= E_Block and then - Ekind (Scope_Id) /= E_Loop; - end loop; - - pragma Assert (Present (Scope_Id)); - - Kind := Ekind (Scope_Id); - Expr := Expression (N); - - if Kind /= E_Function - and then Kind /= E_Generic_Function - and then Kind /= E_Procedure - and then Kind /= E_Generic_Procedure - and then Kind /= E_Entry - and then Kind /= E_Entry_Family - then - Error_Msg_N ("illegal context for return statement", N); - - elsif Present (Expr) then - if Kind = E_Function or else Kind = E_Generic_Function then - Set_Return_Present (Scope_Id); - R_Type := Etype (Scope_Id); - Set_Return_Type (N, R_Type); - Analyze_And_Resolve (Expr, R_Type); - - -- Ada 2005 (AI-318-02): When the result type is an anonymous - -- access type, apply an implicit conversion of the expression - -- to that type to force appropriate static and run-time - -- accessibility checks. - - if Ada_Version >= Ada_05 - and then Ekind (R_Type) = E_Anonymous_Access_Type - then - Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr))); - Analyze_And_Resolve (Expr, R_Type); - end if; - - if (Is_Class_Wide_Type (Etype (Expr)) - or else Is_Dynamically_Tagged (Expr)) - and then not Is_Class_Wide_Type (R_Type) - then - Error_Msg_N - ("dynamically tagged expression not allowed!", Expr); - end if; - - Apply_Constraint_Check (Expr, R_Type); - - -- 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 a - -- special switch. ??? - - -- if Ada_Version >= Ada_05 - -- and then Is_Limited_Type (R_Type) - -- and then Nkind (Expr) /= N_Aggregate - -- and then Nkind (Expr) /= N_Extension_Aggregate - -- and then Nkind (Expr) /= N_Function_Call - -- then - -- Error_Msg_N - -- ("(Ada 2005) illegal operand for limited return", 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 Is_Return_By_Reference_Type (Etype (Scope_Id)) - and then Object_Access_Level (Expr) - > Subprogram_Access_Level (Scope_Id) - then - Rewrite (N, - Make_Raise_Program_Error (Loc, - Reason => PE_Accessibility_Check_Failed)); - Analyze (N); - - Error_Msg_N - ("cannot return a local value by reference?", N); - Error_Msg_NE - ("\& will be raised at run time?", - N, Standard_Program_Error); - end if; - - elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then - Error_Msg_N ("procedure cannot return value (use function)", N); - - else - Error_Msg_N ("accept statement cannot return value", N); - end if; - - -- No expression present - - else - if Kind = E_Function or Kind = E_Generic_Function then - Error_Msg_N ("missing expression in return from function", N); - end if; - - if (Ekind (Scope_Id) = E_Procedure - or else Ekind (Scope_Id) = E_Generic_Procedure) - and then No_Return (Scope_Id) - then - Error_Msg_N - ("RETURN statement not allowed (No_Return)", N); - end if; - end if; - - Check_Unreachable_Code (N); - end Analyze_Return_Statement; - - ------------------------- - -- Analyze_Return_Type -- - ------------------------- - - procedure Analyze_Return_Type (N : Node_Id) is - Designator : constant Entity_Id := Defining_Entity (N); - Typ : Entity_Id := Empty; - - begin - if Result_Definition (N) /= Error then - if Nkind (Result_Definition (N)) = N_Access_Definition then - Typ := Access_Definition (N, Result_Definition (N)); - Set_Parent (Typ, Result_Definition (N)); - Set_Is_Local_Anonymous_Access (Typ); - Set_Etype (Designator, Typ); - - -- Ada 2005 (AI-231): Static checks - - -- Null_Exclusion_Static_Checks needs to be extended to handle - -- null exclusion checks for function specifications. ??? - - -- if Null_Exclusion_Present (N) then - -- Null_Exclusion_Static_Checks (Param_Spec); - -- end if; - - -- Subtype_Mark case - - else - Find_Type (Result_Definition (N)); - Typ := Entity (Result_Definition (N)); - Set_Etype (Designator, Typ); - - if Ekind (Typ) = E_Incomplete_Type - or else (Is_Class_Wide_Type (Typ) - and then - Ekind (Root_Type (Typ)) = E_Incomplete_Type) - then - Error_Msg_N - ("invalid use of incomplete type", Result_Definition (N)); - end if; - end if; - - else - Set_Etype (Designator, Any_Type); - end if; - end Analyze_Return_Type; - - ----------------------------- - -- Analyze_Subprogram_Body -- - ----------------------------- - - -- 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 (N : Node_Id) is - Loc : constant Source_Ptr := Sloc (N); - 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); - Body_Deleted : constant Boolean := False; - - HSS : Node_Id; - Spec_Id : Entity_Id; - Spec_Decl : Node_Id := Empty; - Last_Formal : Entity_Id := Empty; - Conformant : Boolean; - Missing_Ret : Boolean; - P_Ent : Entity_Id; - - 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. - - procedure Copy_Parameter_List (Plist : List_Id); - -- Comment required ??? - - 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_Inline_Pragma -- - ------------------------- - - procedure Check_Inline_Pragma (Spec : in out Node_Id) is - Prag : Node_Id; - Plist : List_Id; - - begin - if not Expander_Active then - return; - end if; - - if Is_List_Member (N) - and then Present (Next (N)) - and then Nkind (Next (N)) = N_Pragma - then - Prag := Next (N); - - if Nkind (Prag) = N_Pragma - and then - (Get_Pragma_Id (Chars (Prag)) = Pragma_Inline_Always - or else - (Front_End_Inlining - and then Get_Pragma_Id (Chars (Prag)) = Pragma_Inline)) - and then - Chars - (Expression (First (Pragma_Argument_Associations (Prag)))) - = Chars (Body_Id) - then - Prag := Next (N); - else - Prag := Empty; - end if; - else - Prag := Empty; - end if; - - if Present (Prag) then - if Present (Spec_Id) then - if List_Containing (N) = - List_Containing (Unit_Declaration_Node (Spec_Id)) - then - Analyze (Prag); - end if; - - else - -- Create a subprogram declaration, to make treatment uniform - - declare - Subp : constant Entity_Id := - Make_Defining_Identifier (Loc, Chars (Body_Id)); - Decl : constant Node_Id := - Make_Subprogram_Declaration (Loc, - Specification => New_Copy_Tree (Specification (N))); - begin - Set_Defining_Unit_Name (Specification (Decl), Subp); - - if Present (First_Formal (Body_Id)) then - Plist := New_List; - Copy_Parameter_List (Plist); - Set_Parameter_Specifications - (Specification (Decl), Plist); - end if; - - Insert_Before (N, Decl); - Analyze (Decl); - Analyze (Prag); - Set_Has_Pragma_Inline (Subp); - - if Get_Pragma_Id (Chars (Prag)) = Pragma_Inline_Always then - Set_Is_Inlined (Subp); - Set_Next_Rep_Item (Prag, First_Rep_Item (Subp)); - Set_First_Rep_Item (Subp, Prag); - end if; - - Spec := Subp; - end; - end if; - end if; - end Check_Inline_Pragma; - - ------------------------- - -- Copy_Parameter_List -- - ------------------------- - - procedure Copy_Parameter_List (Plist : List_Id) is - Formal : Entity_Id; - - begin - Formal := First_Formal (Body_Id); - - while Present (Formal) loop - Append - (Make_Parameter_Specification (Loc, - Defining_Identifier => - Make_Defining_Identifier (Sloc (Formal), - Chars => Chars (Formal)), - In_Present => In_Present (Parent (Formal)), - Out_Present => Out_Present (Parent (Formal)), - Parameter_Type => - New_Reference_To (Etype (Formal), Loc), - Expression => - New_Copy_Tree (Expression (Parent (Formal)))), - Plist); - - Next_Formal (Formal); - end loop; - end Copy_Parameter_List; - - --------------------------------- - -- Verify_Overriding_Indicator -- - --------------------------------- - - procedure Verify_Overriding_Indicator is - begin - if Must_Override (Body_Spec) - and then not Is_Overriding_Operation (Spec_Id) - then - Error_Msg_NE - ("subprogram& is not overriding", Body_Spec, Spec_Id); - - elsif Must_Not_Override (Body_Spec) - and then Is_Overriding_Operation (Spec_Id) - then - Error_Msg_NE - ("subprogram& overrides inherited operation", - Body_Spec, Spec_Id); - end if; - end Verify_Overriding_Indicator; - - -- Start of processing for Analyze_Subprogram_Body - - begin - if Debug_Flag_C then - Write_Str ("==== Compiling subprogram body "); - Write_Name (Chars (Body_Id)); - Write_Str (" from "); - Write_Location (Loc); - Write_Eol; - end if; - - Trace_Scope (N, Body_Id, " Analyze subprogram"); - - -- 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); - 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 - Spec_Id := Find_Corresponding_Spec (N); - - -- 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 the spec are compilation - -- units. - - if No (Spec_Id) then - Freeze_Before (N, Body_Id); - - elsif Nkind (Parent (N)) = N_Compilation_Unit then - Freeze_Before (N, Spec_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); - - -- Case of fully private operation in the body of the protected type. - -- We must create a declaration for the subprogram, in order to attach - -- the protected subprogram that will be used in internal calls. - - if No (Spec_Id) - and then Comes_From_Source (N) - and then Is_Protected_Type (Current_Scope) - then - declare - Decl : Node_Id; - Plist : List_Id; - Formal : Entity_Id; - New_Spec : Node_Id; - - begin - Formal := First_Formal (Body_Id); - - -- The protected operation always has at least one formal, namely - -- the object itself, but it is only placed in the parameter list - -- if expansion is enabled. - - if Present (Formal) - or else Expander_Active - then - Plist := New_List; - - else - Plist := No_List; - end if; - - Copy_Parameter_List (Plist); - - if Nkind (Body_Spec) = N_Procedure_Specification then - New_Spec := - Make_Procedure_Specification (Loc, - Defining_Unit_Name => - Make_Defining_Identifier (Sloc (Body_Id), - Chars => Chars (Body_Id)), - Parameter_Specifications => Plist); - else - New_Spec := - Make_Function_Specification (Loc, - Defining_Unit_Name => - Make_Defining_Identifier (Sloc (Body_Id), - Chars => Chars (Body_Id)), - Parameter_Specifications => Plist, - Result_Definition => - New_Occurrence_Of (Etype (Body_Id), Loc)); - end if; - - Decl := - Make_Subprogram_Declaration (Loc, - Specification => New_Spec); - Insert_Before (N, Decl); - Spec_Id := Defining_Unit_Name (New_Spec); - - -- Indicate that the entity comes from source, to ensure that - -- cross-reference information is properly generated. The body - -- itself is rewritten during expansion, and the body entity will - -- not appear in calls to the operation. - - Set_Comes_From_Source (Spec_Id, True); - Analyze (Decl); - Set_Has_Completion (Spec_Id); - Set_Convention (Spec_Id, Convention_Protected); - end; - - elsif Present (Spec_Id) then - Spec_Decl := Unit_Declaration_Node (Spec_Id); - Verify_Overriding_Indicator; - 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 (Spec_Id) then - Error_Msg_N ("an abstract subprogram cannot have a body", N); - return; - else - Set_Convention (Body_Id, Convention (Spec_Id)); - Set_Has_Completion (Spec_Id); - - if Is_Protected_Type (Scope (Spec_Id)) then - Set_Privals_Chain (Spec_Id, New_Elmt_List); - 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; - 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): Restore the correct Etype: here we undo the - -- work done by Analyze_Subprogram_Specification to allow the - -- overriding of task, protected and interface primitives. - - if Comes_From_Source (Spec_Id) - and then Present (First_Entity (Spec_Id)) - and then Ekind (Etype (First_Entity (Spec_Id))) = E_Record_Type - and then Is_Tagged_Type (Etype (First_Entity (Spec_Id))) - and then Present (Abstract_Interfaces - (Etype (First_Entity (Spec_Id)))) - and then Present (Corresponding_Concurrent_Type - (Etype (First_Entity (Spec_Id)))) - then - Set_Etype (First_Entity (Spec_Id), - Corresponding_Concurrent_Type - (Etype (First_Entity (Spec_Id)))); - end if; - - -- Ada 2005: A formal that is an access parameter may have a - -- designated type imported through a limited_with clause, while - -- the body has a regular with clause. Update the types of the - -- formals accordingly, so that the non-limited view of each type - -- is available in the body. We have already verified that the - -- declarations are type-conformant. - - if Ada_Version >= Ada_05 then - declare - F_Spec : Entity_Id; - F_Body : Entity_Id; - - begin - F_Spec := First_Formal (Spec_Id); - F_Body := First_Formal (Body_Id); - - while Present (F_Spec) loop - if Ekind (Etype (F_Spec)) = E_Anonymous_Access_Type - and then - From_With_Type (Designated_Type (Etype (F_Spec))) - then - Set_Etype (F_Spec, Etype (F_Body)); - end if; - - Next_Formal (F_Spec); - Next_Formal (F_Body); - end loop; - end; - end if; - - -- Now make the formals visible, and place subprogram - -- on scope stack. - - Install_Formals (Spec_Id); - Last_Formal := Last_Entity (Spec_Id); - New_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)); - - -- Case of subprogram body with no previous spec - - else - if Style_Check - and then Comes_From_Source (Body_Id) - and then not Suppress_Style_Checks (Body_Id) - and then not In_Instance - 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); - Generate_Reference - (Body_Id, Body_Id, 'b', Set_Ref => False, Force => True); - Generate_Reference_To_Formals (Body_Id); - Install_Formals (Body_Id); - New_Scope (Body_Id); - end if; - 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 - (Is_Always_Inlined (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 - -- if its specification we have to install the private withed units. - - if Is_Compilation_Unit (Body_Id) - and then Scope (Body_Id) = Standard_Standard - then - Install_Private_With_Clauses (Body_Id); - end if; - - -- Now we can go on to analyze the body - - HSS := Handled_Statement_Sequence (N); - Set_Actual_Subtypes (N, Current_Scope); - Analyze_Declarations (Declarations (N)); - Check_Completion; - Analyze (HSS); - 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; - - if Present (Last_Formal) then - Set_Next_Entity - (Last_Entity (Body_Id), Next_Entity (Last_Formal)); - Set_Next_Entity (Last_Formal, Empty); - Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); - Set_Last_Entity (Spec_Id, Last_Formal); - - else - 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; - - -- If function, check return statements - - if Nkind (Body_Spec) = N_Function_Specification then - declare - Id : Entity_Id; - - begin - 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 not Is_Machine_Code_Subprogram (Id) - and then not Body_Deleted - then - Error_Msg_N ("missing RETURN statement in function body", N); - end if; - end; - - -- 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; - - -- Now we are going to check for variables that are never modified in - -- the body of the procedure. We omit these checks if the first - -- 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! - - declare - Stm : Node_Id := First (Statements (HSS)); - - begin - -- Skip an initial label (for one thing this occurs when we are in - -- front end ZCX mode, but in any case it is irrelevant). - - if Nkind (Stm) = N_Label then - Next (Stm); - end if; - - -- Do the test on the original statement before expansion - - declare - Ostm : constant Node_Id := Original_Node (Stm); - - begin - -- If explicit raise statement, return with no checks - - if Nkind (Ostm) = N_Raise_Statement then - return; - - -- 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 no need to check beyond the call. - - if Ekind (Ent) = E_Procedure - and then No_Return (Ent) - then - return; - - -- If the procedure name is Raise_Exception, then also - -- assume that it raises an exception. The main target - -- here is Ada.Exceptions.Raise_Exception, but this name - -- is pretty evocative in any context! Note that the - -- procedure in Ada.Exceptions is not marked No_Return - -- because of the annoying case of the null exception Id. - - elsif Chars (Ent) = Name_Raise_Exception then - return; - 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; - - ------------------------------------ - -- Analyze_Subprogram_Declaration -- - ------------------------------------ - - procedure Analyze_Subprogram_Declaration (N : Node_Id) is - Designator : constant Entity_Id := - Analyze_Subprogram_Specification (Specification (N)); - Scop : constant Entity_Id := Current_Scope; - - -- Start of processing for Analyze_Subprogram_Declaration - - begin - Generate_Definition (Designator); - - -- Check for RCI unit subprogram declarations against in-lined - -- subprograms and subprograms having access parameter or limited - -- parameter without Read and Write (RM E.2.3(12-13)). - - Validate_RCI_Subprogram_Declaration (N); - - Trace_Scope - (N, - Defining_Entity (N), - " Analyze subprogram spec. "); - - if Debug_Flag_C then - Write_Str ("==== Compiling subprogram spec "); - Write_Name (Chars (Designator)); - Write_Str (" from "); - Write_Location (Sloc (N)); - Write_Eol; - end if; - - New_Overloaded_Entity (Designator); - Check_Delayed_Subprogram (Designator); - - -- 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 - - New_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_05 - and then Nkind (Specification (N)) = N_Procedure_Specification - and then Null_Present (Specification (N)) - then - Error_Msg_N - ("null procedure cannot be declared at library level", N); - end if; - end if; - - Generate_Reference_To_Formals (Designator); - Check_Eliminated (Designator); - - -- Ada 2005: if procedure is declared with "is null" qualifier, - -- it requires no body. - - if Nkind (Specification (N)) = N_Procedure_Specification - and then Null_Present (Specification (N)) - then - Set_Has_Completion (Designator); - Set_Is_Inlined (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); - - function Has_Interface_Formals (T : List_Id) return Boolean; - -- Ada 2005 (AI-251): Returns true if some non class-wide interface - -- formal is found. - - --------------------------- - -- Has_Interface_Formals -- - --------------------------- - - function Has_Interface_Formals (T : List_Id) return Boolean is - Param_Spec : Node_Id; - Formal : Entity_Id; - - begin - Param_Spec := First (T); - - while Present (Param_Spec) loop - Formal := Defining_Identifier (Param_Spec); - - if Is_Class_Wide_Type (Etype (Formal)) then - null; - - elsif Is_Interface (Etype (Formal)) then - return True; - end if; - - Next (Param_Spec); - end loop; - - return False; - end Has_Interface_Formals; - - -- Start of processing for Analyze_Subprogram_Specification - - begin - Generate_Definition (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 of the - -- return type. - - Set_Scope (Designator, Current_Scope); - - if Present (Formals) then - New_Scope (Designator); - Process_Formals (Formals, N); - - -- Ada 2005 (AI-345): Allow overriding primitives of protected - -- interfaces by means of normal subprograms. For this purpose - -- temporarily use the corresponding record type as the etype - -- of the first formal. - - if Ada_Version >= Ada_05 - and then Comes_From_Source (Designator) - and then Present (First_Entity (Designator)) - and then (Ekind (Etype (First_Entity (Designator))) - = E_Protected_Type - or else - Ekind (Etype (First_Entity (Designator))) - = E_Task_Type) - and then Present (Corresponding_Record_Type - (Etype (First_Entity (Designator)))) - and then Present (Abstract_Interfaces - (Corresponding_Record_Type - (Etype (First_Entity (Designator))))) - then - Set_Etype (First_Entity (Designator), - Corresponding_Record_Type (Etype (First_Entity (Designator)))); - end if; - - End_Scope; - - elsif Nkind (N) = N_Function_Specification then - Analyze_Return_Type (N); - end if; - - if Nkind (N) = N_Function_Specification then - if Nkind (Designator) = N_Defining_Operator_Symbol then - Valid_Operator_Definition (Designator); - end if; - - May_Need_Actuals (Designator); - - if Is_Abstract (Etype (Designator)) - and then Nkind (Parent (N)) - /= N_Abstract_Subprogram_Declaration - and then (Nkind (Parent (N))) - /= N_Formal_Abstract_Subprogram_Declaration - and then (Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration - or else not Is_Entity_Name (Name (Parent (N))) - or else not Is_Abstract (Entity (Name (Parent (N))))) - then - Error_Msg_N - ("function that returns abstract type must be abstract", N); - end if; - end if; - - if Ada_Version >= Ada_05 - and then Comes_From_Source (N) - and then Nkind (Parent (N)) /= N_Abstract_Subprogram_Declaration - and then (Nkind (N) /= N_Procedure_Specification - or else - not Null_Present (N)) - and then Has_Interface_Formals (Formals) - then - Error_Msg_Name_1 := Chars (Defining_Unit_Name - (Specification (Parent (N)))); - Error_Msg_N - ("(Ada 2005) interface subprogram % must be abstract or null", N); - 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 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 (Id) = N_Selected_Component - or else Nkind (Id) = 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 (D) = N_Protected_Type_Declaration - or else Nkind (D) = N_Package_Declaration - or else Nkind (D) = N_Package_Instantiation - or else Nkind (D) = N_Subprogram_Body - or else Nkind (D) = N_Procedure_Instantiation - or else Nkind (D) = N_Task_Type_Declaration - 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 (S) = N_Abort_Statement - or else Nkind (S) = N_Asynchronous_Select - or else Nkind (S) = N_Conditional_Entry_Call - or else Nkind (S) = N_Delay_Relative_Statement - or else Nkind (S) = N_Delay_Until_Statement - or else Nkind (S) = N_Selective_Accept - or else Nkind (S) = N_Timed_Entry_Call - 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; - 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 := Current_Scope; - - begin - 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_Return_Statement then - if Present (Expression (N)) - and then Is_Entity_Name (Expression (N)) - then - if No (Return_Statement) then - Return_Statement := N; - return OK; - - elsif Chars (Expression (N)) = - Chars (Expression (Return_Statement)) - then - return OK; - - else - return Abandon; - end if; - - else - -- Expression has wrong form - - return Abandon; - end if; - - else - return OK; - end if; - end Check_Return; - - function Check_All_Returns is new Traverse_Func (Check_Return); - - -- Start of processing for Has_Single_Return - - begin - return Check_All_Returns (N) = OK - and then Present (Declarations (N)) - and then Chars (Expression (Return_Statement)) = - Chars (Defining_Identifier (First (Declarations (N)))); - 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 Chars (Decl) = Name_Unreferenced - 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 - if Nkind (Decl) = N_Subprogram_Declaration - and then Present (Body_To_Inline (Decl)) - then - return; -- Done already. - - -- 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 Controlled_Type (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 Is_Always_Inlined (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. - - if In_Instance 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); - New_Scope (Defining_Entity (Body_To_Analyze)); - Save_Global_References (Original_Body); - End_Scope; - Remove (Body_To_Analyze); - - Expander_Mode_Restore; - - if In_Instance then - Restore_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 Is_Always_Inlined (Subp) then - - -- Remove last character (question mark) to make this into an error, - -- because the Inline_Always pragma cannot be obeyed. - - Error_Msg_NE (Msg (1 .. Msg'Length - 1), N, Subp); - - 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 - Old_Type : constant Entity_Id := Etype (Old_Id); - New_Type : constant Entity_Id := Etype (New_Id); - Old_Formal : Entity_Id; - New_Formal : Entity_Id; - - procedure Conformance_Error (Msg : String; N : Node_Id := New_Id); - -- Post error message for conformance error on given node. Two messages - -- are output. The first points to the previous declaration with a - -- 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 - ("not type conformant with declaration#!", Enode); - - when Mode_Conformant => - Error_Msg_N - ("not mode conformant with declaration#!", Enode); - - when Subtype_Conformant => - Error_Msg_N - ("not subtype conformant with declaration#!", Enode); - - when Fully_Conformant => - Error_Msg_N - ("not fully conformant with declaration#!", Enode); - end case; - - Error_Msg_NE (Msg, Enode, N); - end if; - end Conformance_Error; - - -- 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 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 must match. - - if Ada_Version >= Ada_05 - and then Ekind (Etype (Old_Type)) = E_Anonymous_Access_Type - and then - (Can_Never_Be_Null (Old_Type) - /= Can_Never_Be_Null (New_Type) - or else Is_Access_Constant (Etype (Old_Type)) - /= Is_Access_Constant (Etype (New_Type))) - then - Conformance_Error ("return type does not match!", New_Id); - return; - end if; - - -- 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 - goto Skip_Controlling_Formal; - end if; - - if Ctype = Fully_Conformant then - - -- Names must match. Error message is more accurate if we do - -- this before checking that the types of the formals match. - - if Chars (Old_Formal) /= Chars (New_Formal) then - Conformance_Error ("name & does not match!", New_Formal); - - -- 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; - end if; - - -- 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 - (Base_Type (Etype (Old_Formal)), - Base_Type (Etype (New_Formal)), Ctype, Get_Inst) - then - Conformance_Error ("type of & does not match!", New_Formal); - return; - end if; - - elsif not Conforming_Types - (Etype (Old_Formal), Etype (New_Formal), Ctype, Get_Inst) - then - Conformance_Error ("type of & does not match!", New_Formal); - return; - end if; - - -- For mode conformance, mode must match - - if Ctype >= Mode_Conformant - and then Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal) - then - Conformance_Error ("mode of & does not match!", New_Formal); - return; - 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 - - -- Ada 2005 (AI-231): In case of anonymous access types check - -- the null-exclusion and access-to-constant attributes must - -- match. - - if Ada_Version >= Ada_05 - and then Ekind (Etype (Old_Formal)) = E_Anonymous_Access_Type - and then - (Can_Never_Be_Null (Old_Formal) - /= Can_Never_Be_Null (New_Formal) - or else Is_Access_Constant (Etype (Old_Formal)) - /= Is_Access_Constant (Etype (New_Formal))) - then - -- It is allowed to omit the null-exclusion in case of - -- stream attribute subprograms - - declare - TSS_Name : TSS_Name_Type; - - begin - Get_Name_String (Chars (New_Id)); - TSS_Name := - TSS_Name_Type - (Name_Buffer - (Name_Len - TSS_Name'Length + 1 .. Name_Len)); - - 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; - - -- 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 values have not been - -- analyzed, so analyze them now before we check for - -- conformance. - - if NewD then - New_Scope (New_Id); - Analyze_Per_Use_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_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. - - --------------------- - -- 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); - end if; - end Possible_Freeze; - - -- Start of processing for Check_Delayed_Subprogram - - begin - -- Never need to freeze abstract subprogram - - if Is_Abstract (Designator) then - null; - else - -- Need delayed freeze if return type itself needs a delayed - -- freeze and is not yet frozen. - - 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; - end if; - - -- 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_Return_By_Reference_Type (Typ) then - Set_Returns_By_Ref (Designator); - - elsif Present (Utyp) and then Controlled_Type (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 ("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)); - 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 - Analyze_Per_Use_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; - 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; - - 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; - Does_Override : Boolean) - is - Decl : Node_Id; - Spec : Node_Id; - - begin - if Ekind (Subp) = E_Enumeration_Literal then - - -- No overriding indicator for literals - - return; - - else - Decl := Unit_Declaration_Node (Subp); - end if; - - if Nkind (Decl) = N_Subprogram_Declaration - or else Nkind (Decl) = N_Subprogram_Body - or else Nkind (Decl) = N_Subprogram_Renaming_Declaration - or else Nkind (Decl) = N_Subprogram_Body_Stub - then - Spec := Specification (Decl); - else - return; - end if; - - if not Does_Override then - if Must_Override (Spec) then - Error_Msg_NE ("subprogram& is not overriding", Spec, Subp); - end if; - - else - if Must_Not_Override (Spec) then - Error_Msg_NE - ("subprogram& overrides inherited operation", Spec, Subp); - end if; - end if; - end Check_Overriding_Indicator; - - ------------------- - -- Check_Returns -- - ------------------- - - 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; - 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); - - -- 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 (Last_Stm) = N_Goto_Statement - or else Nkind (Last_Stm) = N_Label - or else Nkind (Last_Stm) = N_Object_Declaration) - and then Exception_Junk (Last_Stm)) - 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 if either - -- an inifite 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 - 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); - - 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_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) - is - Result : Boolean; - begin - Check_Conformance - (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc); - 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; - begin - Check_Conformance - (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc); - end Check_Type_Conformant; - - ---------------------- - -- 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. - - ---------------------- - -- 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 must - -- 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); - - -- In some cases a type imported through a limited_with clause, - -- and its non-limited view are both visible, for example in an - -- anonymous access_to_classwide type in a formal. Both entities - -- designate the same type. - - elsif From_With_Type (T1) - and then Ekind (T1) = E_Incomplete_Type - and then T2 = Non_Limited_View (T1) - then - return True; - - elsif From_With_Type (T2) - and then Ekind (T2) = E_Incomplete_Type - and then T1 = Non_Limited_View (T2) - then - return True; - - else - return False; - end if; - end Base_Types_Match; - - -- 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; - - -- First see if base types match - - if 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 := - - -- Case 1: Anonymous access to subprogram types - - (Ekind (Type_1) = E_Anonymous_Access_Subprogram_Type - and then Ekind (Type_2) = E_Anonymous_Access_Subprogram_Type) - - -- Case 2: Anonymous access to PROTECTED subprogram types. In this - -- case the anonymous type_declaration has been replaced by an - -- occurrence of an internal access to subprogram type declaration - -- available through the Original_Access_Type attribute - - or else - (Ekind (Type_1) = E_Access_Protected_Subprogram_Type - and then Ekind (Type_2) = E_Access_Protected_Subprogram_Type - and then not Comes_From_Source (Type_1) - and then not Comes_From_Source (Type_2) - and then Present (Original_Access_Type (Type_1)) - and then Present (Original_Access_Type (Type_2)) - and then Ekind (Original_Access_Type (Type_1)) = - E_Anonymous_Access_Protected_Subprogram_Type - and then Ekind (Original_Access_Type (Type_2)) = - E_Anonymous_Access_Protected_Subprogram_Type); - - -- Test anonymous access type case. For this case, static subtype - -- matching is required for mode conformance (RM 6.3.1(15)) - - if (Ekind (Type_1) = E_Anonymous_Access_Type - and then Ekind (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 - Desig_1 := Directly_Designated_Type (Type_1); - - -- 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 Ekind (Desig_1) = E_Incomplete_Type then - if Present (Full_View (Desig_1)) then - Desig_1 := Full_View (Desig_1); - - elsif Present (Non_Limited_View (Desig_1)) then - Desig_1 := Non_Limited_View (Desig_1); - end if; - end if; - - Desig_2 := Directly_Designated_Type (Type_2); - - if Ekind (Desig_2) = E_Incomplete_Type then - if Present (Full_View (Desig_2)) then - Desig_2 := Full_View (Desig_2); - elsif Present (Non_Limited_View (Desig_2)) then - Desig_2 := Non_Limited_View (Desig_2); - end if; - end 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_05 then - return Ctype = Type_Conformant - or else - Subtypes_Statically_Match (Desig_1, Desig_2); - - -- We must check the conformance of the signatures themselves - - else - declare - Conformant : Boolean; - begin - Check_Conformance - (Desig_1, Desig_2, Ctype, False, Conformant); - return Conformant; - end; - end if; - - else - return Base_Type (Desig_1) = Base_Type (Desig_2) - and then (Ctype = Type_Conformant - 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; - Last_Extra : Entity_Id; - Formal_Type : Entity_Id; - P_Formal : Entity_Id := Empty; - - function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id; - -- Add an extra formal, associated with the current Formal. The extra - -- formal is added to the list of extra formals, and also returned as - -- the result. These formals are always of mode IN. - - ---------------------- - -- Add_Extra_Formal -- - ---------------------- - - function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id is - EF : constant Entity_Id := - Make_Defining_Identifier (Sloc (Formal), - Chars => New_External_Name (Chars (Formal), 'F')); - - begin - -- We never generate extra formals if expansion is not active - -- because we don't need them unless we are generating code. - - if not Expander_Active then - return Empty; - end if; - - -- A little optimization. Never generate an extra formal for the - -- _init operand of an initialization procedure, since it could - -- never be used. - - 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 (Formal)); - Set_Mechanism (EF, Default_Mechanism); - Set_Formal_Validity (EF); - - Set_Extra_Formal (Last_Extra, EF); - Last_Extra := EF; - return EF; - end Add_Extra_Formal; - - -- Start of processing for Create_Extra_Formals - - begin - -- If this is a derived subprogram then the subtypes of the parent - -- subprogram's formal parameters will be used to to determine the need - -- for extra formals. - - 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 where 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; - - 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; - - if Has_Discriminants (Formal_Type) - and then - ((not Is_Constrained (Formal_Type) - and then not Is_Indefinite_Subtype (Formal_Type)) - or else Present (Extra_Formal (Formal))) - then - Set_Extra_Constrained - (Formal, Add_Extra_Formal (Standard_Boolean)); - end if; - end if; - - -- Create extra formal for supporting accessibility checking - - -- This is suppressed if we specifically suppress accessibility - -- checks at the pacage level for either the subprogram, or the - -- package in which it resides. However, we do not suppress it - -- simply if the scope has accessibility checks suppressed, since - -- this could cause trouble when clients are compiled with a - -- different suppression setting. The explicit checks at the - -- package level are safe from this point of view. - - if Ekind (Etype (Formal)) = E_Anonymous_Access_Type - 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 - -- Temporary kludge: for now we avoid creating the extra formal - -- for access parameters of protected operations because of - -- problem with the case of internal protected calls. ??? - - if Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Definition - and then Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Body - then - Set_Extra_Accessibility - (Formal, Add_Extra_Formal (Standard_Natural)); - end if; - end if; - - if Present (P_Formal) then - Next_Formal (P_Formal); - end if; - - -- This label is required when skipping extra formal generation for - -- Unchecked_Union parameters. - - <<Skip_Extra_Formal_Generation>> - - Next_Formal (Formal); - end loop; - 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 - - if (not Is_Overloadable (E)) - or else Subtype_Conformant (E, S) - then - Error_Msg_Sloc := Sloc (E); - Error_Msg_N ("declaration of & hides one#?", S); - end if; - end loop; - end if; - end Enter_Overloaded_Entity; - - ----------------------------- - -- Find_Corresponding_Spec -- - ----------------------------- - - function Find_Corresponding_Spec (N : Node_Id) 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)); - - if Nkind (N) = N_Subprogram_Body - and then Present (Homonym (E)) - and then not Fully_Conformant (E, Designator) - then - goto Next_Entity; - - elsif not Subtype_Conformant (E, Designator) then - goto Next_Entity; - end if; - end if; - - if 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 body already exists, this is an error unless the - -- previous declaration is the implicit declaration of - -- a derived subprogram, or this is a spurious overloading - -- in an instance. - - elsif No (Alias (E)) - and then not Is_Intrinsic_Subprogram (E) - and then not In_Instance - 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; - - 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 - then - - -- Child units cannot be overloaded, so a conformance mismatch - -- between body and a previous spec is an error. - - 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_And_Then | N_Or_Else | N_In | N_Not_In => - return - FCE (Left_Opnd (E1), Left_Opnd (E2)) - and then - FCE (Right_Opnd (E1), Right_Opnd (E2)); - - 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_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 - - 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; - - 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_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; - 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.) - - Indic := Subtype_Indication - (Type_Definition (Original_Node (Parent (F_Typ)))); - - 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; - - 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 subtype of the inherited - -- operation, to determine whether their type is derived from (the - -- instance of) a generic type. - - 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); - - 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). - - return True; - end; - end if; - else - return False; - end if; - end Is_Non_Overriding_Operation; - - ------------------------------ - -- 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 (Op_Name, Is_Abstract (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 - Does_Override : Boolean := False; - -- Set if the current scope has an operation that is type-conformant - -- with S, and becomes hidden by S. - - E : Entity_Id; - -- Entity that S overrides - - Prev_Vis : Entity_Id := Empty; - -- Needs comment ??? - - Is_Alias_Interface : Boolean := False; - - function Is_Private_Declaration (E : Entity_Id) return Boolean; - -- Check that E is declared in the private part of the current package, - -- or in the package body, where it may hide a previous declaration. - -- We can't use In_Private_Part by itself because this flag is also - -- set when freezing entities, so we must examine the place of the - -- declaration in the tree, and recognize wrapper packages as well. - - procedure Maybe_Primitive_Operation (Is_Overriding : Boolean := False); - -- If the subprogram being analyzed is a primitive operation of - -- the type of one of its formals, set the corresponding flag. - - ---------------------------- - -- Is_Private_Declaration -- - ---------------------------- - - function Is_Private_Declaration (E : Entity_Id) return Boolean is - Priv_Decls : List_Id; - Decl : constant Node_Id := Unit_Declaration_Node (E); - - begin - if Is_Package_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; - - ------------------------------- - -- Maybe_Primitive_Operation -- - ------------------------------- - - procedure Maybe_Primitive_Operation (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 Ekind (Current_Scope) = E_Package - and then In_Private_Part (Current_Scope) - and then Visible_Part_Type (T) - and then not In_Instance - then - if Is_Abstract (T) - and then Is_Abstract (S) - and then (not Is_Overriding or else not Is_Abstract (E)) - then - if not Is_Interface (T) then - Error_Msg_N ("abstract subprograms must be visible " - & "('R'M 3.9.3(10))!", S); - - -- Ada 2005 (AI-251) - - else - Error_Msg_N ("primitive subprograms of interface types " - & "declared in a visible part, must be declared in " - & "the visible part ('R'M 3.9.4)!", S); - end if; - - elsif Ekind (S) = E_Function - and then Is_Tagged_Type (T) - and then T = Base_Type (Etype (S)) - and then not Is_Overriding - then - Error_Msg_N - ("private function with tagged result must" - & " override visible-part function", S); - Error_Msg_N - ("\move subprogram to the visible part" - & " ('R'M 3.9.3(10))", S); - 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 (N) = N_Private_Type_Declaration - or else - Nkind (N) = 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 Maybe_Primitive_Operation - - begin - if not Comes_From_Source (S) then - null; - - -- If the subprogram is at library level, it is not primitive - -- operation. - - elsif Current_Scope = Standard_Standard then - null; - - elsif (Ekind (Current_Scope) = E_Package - and then not In_Package_Body (Current_Scope)) - or else Is_Overriding - then - -- For function, check return type - - if Ekind (S) = E_Function then - B_Typ := Base_Type (Etype (S)); - - if Scope (B_Typ) = Current_Scope then - Set_Has_Primitive_Operations (B_Typ); - 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 Scope (B_Typ) = Current_Scope then - Set_Has_Primitive_Operations (B_Typ); - Check_Private_Overriding (B_Typ); - end if; - - Next_Formal (Formal); - end loop; - end if; - end Maybe_Primitive_Operation; - - -- 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); - - -- If there is no homonym then this is definitely not overriding - - if No (E) then - Enter_Overloaded_Entity (S); - Check_Dispatching_Operation (S, Empty); - Maybe_Primitive_Operation; - - -- Ada 2005 (AI-397): Subprograms in the context of protected - -- types have their overriding indicators checked in Sem_Ch9. - - if Ekind (S) not in Subprogram_Kind - or else Ekind (Scope (S)) /= E_Protected_Type - then - Check_Overriding_Indicator (S, False); - 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, 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); - Error_Msg_N ("& conflicts with declaration#", S); - - -- Useful additional warning - - if Is_Generic_Unit (E) then - Error_Msg_N ("\previous generic unit cannot be overloaded", S); - end if; - - return; - end if; - - -- E exists and is overloadable - - else - Is_Alias_Interface := - Present (Alias (S)) - and then Is_Dispatching_Operation (Alias (S)) - and then Present (DTC_Entity (Alias (S))) - and then Is_Interface (Scope (DTC_Entity (Alias (S)))); - - -- 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; - - -- Check if we have type conformance - - -- Ada 2005 (AI-251): In case of overriding an interface - -- subprogram it is not an error that the old and new entities - -- have the same profile, and hence we skip this code. - - elsif not Is_Alias_Interface - and then Type_Conformant (E, S) - - -- Ada 2005 (AI-251): Do not consider here entities that cover - -- abstract interface primitives. They will be handled after - -- the overriden entity is found (see comments bellow inside - -- this subprogram). - - and then not (Is_Subprogram (E) - and then Present (Abstract_Interface_Alias (E))) - 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 inhertited operation - -- of a tagged full type overrides the ineherited operation of - -- a private extension. Ada 83 had a special rule for the the - -- literal case. In Ada95, the later implicit operation hides - -- the former, and the literal is always the former. In the - -- 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 - -- involving homographs in instances and can't occur for - -- dispatching operations ???). Note that the following - -- condition is less than clear. For example, it's not at all - -- clear why there's a test for E_Entry here. ??? - - if Present (Alias (S)) - and then (No (Alias (E)) - or else Comes_From_Source (E) - or else Is_Dispatching_Operation (E)) - and then - (Ekind (E) = E_Entry - or else 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. - - Set_Is_Overriding_Operation (E); - - if Comes_From_Source (E) then - Check_Overriding_Indicator (E, True); - - -- Indicate that E overrides the operation from which - -- S is inherited. - - if Present (Alias (S)) then - Set_Overridden_Operation (E, Alias (S)); - else - Set_Overridden_Operation (E, S); - end if; - end if; - - return; - - -- Within an instance, the renaming declarations for - -- 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). - - Does_Override := True; - - 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 need 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); - Set_Is_Overriding_Operation (S); - Check_Overriding_Indicator (S, True); - - -- Indicate that S overrides the operation from which - -- E is inherited. - - if Comes_From_Source (S) then - if Present (Alias (E)) then - Set_Overridden_Operation (S, Alias (E)); - else - Set_Overridden_Operation (S, E); - end if; - end if; - - if Is_Dispatching_Operation (E) then - - -- An overriding dispatching subprogram inherits the - -- convention of the overridden subprogram (by - -- AI-117). - - Set_Convention (S, Convention (E)); - - -- AI-251: For an entity overriding an interface - -- primitive check if the entity also covers other - -- abstract subprograms in the same scope. This is - -- required to handle the general case, that is, - -- 1) overriding other interface primitives, and - -- 2) overriding abstract subprograms inherited from - -- some abstract ancestor type. - - if Has_Homonym (E) - and then Present (Alias (E)) - and then Ekind (Alias (E)) /= E_Operator - and then Present (DTC_Entity (Alias (E))) - and then Is_Interface (Scope (DTC_Entity - (Alias (E)))) - then - declare - E1 : Entity_Id; - - begin - E1 := Homonym (E); - while Present (E1) loop - if (Is_Overloadable (E1) - or else Ekind (E1) = E_Subprogram_Type) - and then Present (Alias (E1)) - and then Ekind (Alias (E1)) /= E_Operator - and then Present (DTC_Entity (Alias (E1))) - and then Is_Abstract - (Scope (DTC_Entity (Alias (E1)))) - and then Type_Conformant (E1, S) - then - Check_Dispatching_Operation (S, E1); - end if; - - E1 := Homonym (E1); - end loop; - end; - end if; - - Check_Dispatching_Operation (S, E); - - -- AI-251: Handle the case in which the entity - -- overrides a primitive operation that covered - -- several abstract interface primitives. - - declare - E1 : Entity_Id; - begin - E1 := Current_Entity_In_Scope (S); - while Present (E1) loop - if Is_Subprogram (E1) - and then Present - (Abstract_Interface_Alias (E1)) - and then Alias (E1) = E - then - Set_Alias (E1, S); - end if; - - E1 := Homonym (E1); - end loop; - end; - - else - Check_Dispatching_Operation (S, Empty); - end if; - - Maybe_Primitive_Operation (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); - - Error_Msg_N ("& conflicts with declaration#", S); - - if Is_Generic_Instance (S) - and then not Has_Completion (E) - then - Error_Msg_N - ("\instantiation cannot provide body for it", 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; - - Prev_Vis := E; - E := Homonym (E); - end loop; - - -- On exit, we know that S is a new entity - - Enter_Overloaded_Entity (S); - Maybe_Primitive_Operation; - Check_Overriding_Indicator (S, Does_Override); - - -- If S is a derived operation for an untagged type then by - -- definition it's not a dispatching operation (even if the parent - -- operation was dispatching), so we don't call - -- Check_Dispatching_Operation in that case. - - if 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); - 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; - - 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. - - --------------------------- - -- 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); - 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 Ekind (Formal_Type) = E_Incomplete_Type - or else (Is_Class_Wide_Type (Formal_Type) - and then Ekind (Root_Type (Formal_Type)) = - E_Incomplete_Type) - then - -- Ada 2005 (AI-326): Tagged incomplete types allowed - - if Is_Tagged_Type (Formal_Type) then - null; - - elsif Nkind (Parent (T)) /= N_Access_Function_Definition - and then Nkind (Parent (T)) /= N_Access_Procedure_Definition - then - Error_Msg_N ("invalid use of incomplete type", Param_Spec); - end if; - - elsif Ekind (Formal_Type) = E_Void then - Error_Msg_NE ("premature use of&", - Parameter_Type (Param_Spec), Formal_Type); - 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_05 - and then Is_Access_Type (Formal_Type) - and then Null_Exclusion_Present (Param_Spec) - then - if Can_Never_Be_Null (Formal_Type) - and then Comes_From_Source (Related_Nod) - then - Error_Msg_N - ("null exclusion must apply to a type that does not " - & "exclude null ('R'M 3.10 (14)", Related_Nod); - end if; - - Formal_Type := - Create_Null_Excluding_Itype - (T => Formal_Type, - Related_Nod => Related_Nod, - Scope_Id => Scope (Current_Scope)); - end if; - - -- An access formal type - - else - Formal_Type := - Access_Definition (Related_Nod, Parameter_Type (Param_Spec)); - - -- 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, Formal_Type); - end if; - end; - end if; - - Set_Etype (Formal, Formal_Type); - Default := Expression (Param_Spec); - - if Present (Default) then - 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). - - Analyze_Per_Use_Expression (Default, Formal_Type); - - -- Check that the designated type of an access parameter's default - -- is not a class-wide type unless the parameter's designated type - -- is also class-wide. - - if Ekind (Formal_Type) = E_Anonymous_Access_Type - and then not From_With_Type (Formal_Type) - and then Is_Class_Wide_Default (Default) - and then not Is_Class_Wide_Type (Designated_Type (Formal_Type)) - then - Error_Msg_N - ("access to class-wide expression not allowed here", Default); - end if; - end if; - - -- Ada 2005 (AI-231): Static checks - - if Ada_Version >= Ada_05 - and then Is_Access_Type (Etype (Formal)) - and then Can_Never_Be_Null (Etype (Formal)) - then - Null_Exclusion_Static_Checks (Param_Spec); - end if; - - <<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; - end if; - - Next (Param_Spec); - end loop; - - end Process_Formals; - - ---------------------------- - -- 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; - - Fs := First_Formal (Spec); - Fb := First_Formal (Bod); - - while Present (Fs) 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 - Loc : constant Source_Ptr := Sloc (N); - Decl : Node_Id; - Formal : Entity_Id; - T : Entity_Id; - First_Stmt : Node_Id := Empty; - AS_Needed : Boolean; - - begin - -- If this is an emtpy 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 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), Loc)); - end if; - - if Nkind (N) = N_Accept_Statement - and then 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 - Error_Msg_N ("functions can only have IN parameters", Spec); - Set_Ekind (Formal_Id, E_In_Parameter); - - 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 Ada95, access parameters are always non- - -- null; In Ada 2005, only if then null_exclusion is explicit. - - if Ada_Version < Ada_05 - or else Can_Never_Be_Null (Etype (Formal_Id)) - then - Set_Is_Known_Non_Null (Formal_Id); - Set_Can_Never_Be_Null (Formal_Id); - end if; - - -- Ada 2005 (AI-231): Null-exclusion access subtype - - elsif Is_Access_Type (Etype (Formal_Id)) - and then Can_Never_Be_Null (Etype (Formal_Id)) - then - Set_Is_Known_Non_Null (Formal_Id); - end if; - - Set_Mechanism (Formal_Id, Default_Mechanism); - 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, Old_Id : Entity_Id) return Boolean is - Result : Boolean; - begin - Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result); - 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; |