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Diffstat (limited to 'gcc-4.4.0/gcc/ada/sem_ch4.adb')
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diff --git a/gcc-4.4.0/gcc/ada/sem_ch4.adb b/gcc-4.4.0/gcc/ada/sem_ch4.adb deleted file mode 100644 index 47fd4e6aa..000000000 --- a/gcc-4.4.0/gcc/ada/sem_ch4.adb +++ /dev/null @@ -1,6696 +0,0 @@ ------------------------------------------------------------------------------- --- -- --- GNAT COMPILER COMPONENTS -- --- -- --- S E M _ C H 4 -- --- -- --- B o d y -- --- -- --- Copyright (C) 1992-2008, Free Software Foundation, Inc. -- --- -- --- GNAT is free software; you can redistribute it and/or modify it under -- --- terms of the GNU General Public License as published by the Free Soft- -- --- ware Foundation; either version 3, or (at your option) any later ver- -- --- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- --- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- --- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- --- for more details. You should have received a copy of the GNU General -- --- Public License distributed with GNAT; see file COPYING3. If not, go to -- --- http://www.gnu.org/licenses for a complete copy of the license. -- --- -- --- GNAT was originally developed by the GNAT team at New York University. -- --- Extensive contributions were provided by Ada Core Technologies Inc. -- --- -- ------------------------------------------------------------------------------- - -with Atree; use Atree; -with Debug; use Debug; -with Einfo; use Einfo; -with Elists; use Elists; -with Errout; use Errout; -with Exp_Util; use Exp_Util; -with Fname; use Fname; -with Itypes; use Itypes; -with Lib; use Lib; -with Lib.Xref; use Lib.Xref; -with Namet; use Namet; -with Namet.Sp; use Namet.Sp; -with Nlists; use Nlists; -with Nmake; use Nmake; -with Opt; use Opt; -with Output; use Output; -with Restrict; use Restrict; -with Rident; use Rident; -with Sem; use Sem; -with Sem_Cat; use Sem_Cat; -with Sem_Ch3; use Sem_Ch3; -with Sem_Ch6; use Sem_Ch6; -with Sem_Ch8; use Sem_Ch8; -with Sem_Disp; use Sem_Disp; -with Sem_Dist; use Sem_Dist; -with Sem_Eval; use Sem_Eval; -with Sem_Res; use Sem_Res; -with Sem_Util; use Sem_Util; -with Sem_Type; use Sem_Type; -with Stand; use Stand; -with Sinfo; use Sinfo; -with Snames; use Snames; -with Tbuild; use Tbuild; - -package body Sem_Ch4 is - - ----------------------- - -- Local Subprograms -- - ----------------------- - - procedure Analyze_Concatenation_Rest (N : Node_Id); - -- Does the "rest" of the work of Analyze_Concatenation, after the left - -- operand has been analyzed. See Analyze_Concatenation for details. - - procedure Analyze_Expression (N : Node_Id); - -- For expressions that are not names, this is just a call to analyze. - -- If the expression is a name, it may be a call to a parameterless - -- function, and if so must be converted into an explicit call node - -- and analyzed as such. This deproceduring must be done during the first - -- pass of overload resolution, because otherwise a procedure call with - -- overloaded actuals may fail to resolve. - - procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id); - -- Analyze a call of the form "+"(x, y), etc. The prefix of the call - -- is an operator name or an expanded name whose selector is an operator - -- name, and one possible interpretation is as a predefined operator. - - procedure Analyze_Overloaded_Selected_Component (N : Node_Id); - -- If the prefix of a selected_component is overloaded, the proper - -- interpretation that yields a record type with the proper selector - -- name must be selected. - - procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id); - -- Procedure to analyze a user defined binary operator, which is resolved - -- like a function, but instead of a list of actuals it is presented - -- with the left and right operands of an operator node. - - procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id); - -- Procedure to analyze a user defined unary operator, which is resolved - -- like a function, but instead of a list of actuals, it is presented with - -- the operand of the operator node. - - procedure Ambiguous_Operands (N : Node_Id); - -- for equality, membership, and comparison operators with overloaded - -- arguments, list possible interpretations. - - procedure Analyze_One_Call - (N : Node_Id; - Nam : Entity_Id; - Report : Boolean; - Success : out Boolean; - Skip_First : Boolean := False); - -- Check one interpretation of an overloaded subprogram name for - -- compatibility with the types of the actuals in a call. If there is a - -- single interpretation which does not match, post error if Report is - -- set to True. - -- - -- Nam is the entity that provides the formals against which the actuals - -- are checked. Nam is either the name of a subprogram, or the internal - -- subprogram type constructed for an access_to_subprogram. If the actuals - -- are compatible with Nam, then Nam is added to the list of candidate - -- interpretations for N, and Success is set to True. - -- - -- The flag Skip_First is used when analyzing a call that was rewritten - -- from object notation. In this case the first actual may have to receive - -- an explicit dereference, depending on the first formal of the operation - -- being called. The caller will have verified that the object is legal - -- for the call. If the remaining parameters match, the first parameter - -- will rewritten as a dereference if needed, prior to completing analysis. - - procedure Check_Misspelled_Selector - (Prefix : Entity_Id; - Sel : Node_Id); - -- Give possible misspelling diagnostic if Sel is likely to be - -- a misspelling of one of the selectors of the Prefix. - -- This is called by Analyze_Selected_Component after producing - -- an invalid selector error message. - - function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean; - -- Verify that type T is declared in scope S. Used to find interpretations - -- for operators given by expanded names. This is abstracted as a separate - -- function to handle extensions to System, where S is System, but T is - -- declared in the extension. - - procedure Find_Arithmetic_Types - (L, R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id); - -- L and R are the operands of an arithmetic operator. Find - -- consistent pairs of interpretations for L and R that have a - -- numeric type consistent with the semantics of the operator. - - procedure Find_Comparison_Types - (L, R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id); - -- L and R are operands of a comparison operator. Find consistent - -- pairs of interpretations for L and R. - - procedure Find_Concatenation_Types - (L, R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id); - -- For the four varieties of concatenation - - procedure Find_Equality_Types - (L, R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id); - -- Ditto for equality operators - - procedure Find_Boolean_Types - (L, R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id); - -- Ditto for binary logical operations - - procedure Find_Negation_Types - (R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id); - -- Find consistent interpretation for operand of negation operator - - procedure Find_Non_Universal_Interpretations - (N : Node_Id; - R : Node_Id; - Op_Id : Entity_Id; - T1 : Entity_Id); - -- For equality and comparison operators, the result is always boolean, - -- and the legality of the operation is determined from the visibility - -- of the operand types. If one of the operands has a universal interpre- - -- tation, the legality check uses some compatible non-universal - -- interpretation of the other operand. N can be an operator node, or - -- a function call whose name is an operator designator. - - function Find_Primitive_Operation (N : Node_Id) return Boolean; - -- Find candidate interpretations for the name Obj.Proc when it appears - -- in a subprogram renaming declaration. - - procedure Find_Unary_Types - (R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id); - -- Unary arithmetic types: plus, minus, abs - - procedure Check_Arithmetic_Pair - (T1, T2 : Entity_Id; - Op_Id : Entity_Id; - N : Node_Id); - -- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid - -- types for left and right operand. Determine whether they constitute - -- a valid pair for the given operator, and record the corresponding - -- interpretation of the operator node. The node N may be an operator - -- node (the usual case) or a function call whose prefix is an operator - -- designator. In both cases Op_Id is the operator name itself. - - procedure Diagnose_Call (N : Node_Id; Nam : Node_Id); - -- Give detailed information on overloaded call where none of the - -- interpretations match. N is the call node, Nam the designator for - -- the overloaded entity being called. - - function Junk_Operand (N : Node_Id) return Boolean; - -- Test for an operand that is an inappropriate entity (e.g. a package - -- name or a label). If so, issue an error message and return True. If - -- the operand is not an inappropriate entity kind, return False. - - procedure Operator_Check (N : Node_Id); - -- Verify that an operator has received some valid interpretation. If none - -- was found, determine whether a use clause would make the operation - -- legal. The variable Candidate_Type (defined in Sem_Type) is set for - -- every type compatible with the operator, even if the operator for the - -- type is not directly visible. The routine uses this type to emit a more - -- informative message. - - function Process_Implicit_Dereference_Prefix - (E : Entity_Id; - P : Node_Id) return Entity_Id; - -- Called when P is the prefix of an implicit dereference, denoting an - -- object E. The function returns the designated type of the prefix, taking - -- into account that the designated type of an anonymous access type may be - -- a limited view, when the non-limited view is visible. - -- If in semantics only mode (-gnatc or generic), the function also records - -- that the prefix is a reference to E, if any. Normally, such a reference - -- is generated only when the implicit dereference is expanded into an - -- explicit one, but for consistency we must generate the reference when - -- expansion is disabled as well. - - procedure Remove_Abstract_Operations (N : Node_Id); - -- Ada 2005: implementation of AI-310. An abstract non-dispatching - -- operation is not a candidate interpretation. - - function Try_Indexed_Call - (N : Node_Id; - Nam : Entity_Id; - Typ : Entity_Id; - Skip_First : Boolean) return Boolean; - -- If a function has defaults for all its actuals, a call to it may in fact - -- be an indexing on the result of the call. Try_Indexed_Call attempts the - -- interpretation as an indexing, prior to analysis as a call. If both are - -- possible, the node is overloaded with both interpretations (same symbol - -- but two different types). If the call is written in prefix form, the - -- prefix becomes the first parameter in the call, and only the remaining - -- actuals must be checked for the presence of defaults. - - function Try_Indirect_Call - (N : Node_Id; - Nam : Entity_Id; - Typ : Entity_Id) return Boolean; - -- Similarly, a function F that needs no actuals can return an access to a - -- subprogram, and the call F (X) interpreted as F.all (X). In this case - -- the call may be overloaded with both interpretations. - - function Try_Object_Operation (N : Node_Id) return Boolean; - -- Ada 2005 (AI-252): Support the object.operation notation - - procedure wpo (T : Entity_Id); - pragma Warnings (Off, wpo); - -- Used for debugging: obtain list of primitive operations even if - -- type is not frozen and dispatch table is not built yet. - - ------------------------ - -- Ambiguous_Operands -- - ------------------------ - - procedure Ambiguous_Operands (N : Node_Id) is - procedure List_Operand_Interps (Opnd : Node_Id); - - -------------------------- - -- List_Operand_Interps -- - -------------------------- - - procedure List_Operand_Interps (Opnd : Node_Id) is - Nam : Node_Id; - Err : Node_Id := N; - - begin - if Is_Overloaded (Opnd) then - if Nkind (Opnd) in N_Op then - Nam := Opnd; - elsif Nkind (Opnd) = N_Function_Call then - Nam := Name (Opnd); - else - return; - end if; - - else - return; - end if; - - if Opnd = Left_Opnd (N) then - Error_Msg_N - ("\left operand has the following interpretations", N); - else - Error_Msg_N - ("\right operand has the following interpretations", N); - Err := Opnd; - end if; - - List_Interps (Nam, Err); - end List_Operand_Interps; - - -- Start of processing for Ambiguous_Operands - - begin - if Nkind (N) in N_Membership_Test then - Error_Msg_N ("ambiguous operands for membership", N); - - elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) then - Error_Msg_N ("ambiguous operands for equality", N); - - else - Error_Msg_N ("ambiguous operands for comparison", N); - end if; - - if All_Errors_Mode then - List_Operand_Interps (Left_Opnd (N)); - List_Operand_Interps (Right_Opnd (N)); - else - Error_Msg_N ("\use -gnatf switch for details", N); - end if; - end Ambiguous_Operands; - - ----------------------- - -- Analyze_Aggregate -- - ----------------------- - - -- Most of the analysis of Aggregates requires that the type be known, - -- and is therefore put off until resolution. - - procedure Analyze_Aggregate (N : Node_Id) is - begin - if No (Etype (N)) then - Set_Etype (N, Any_Composite); - end if; - end Analyze_Aggregate; - - ----------------------- - -- Analyze_Allocator -- - ----------------------- - - procedure Analyze_Allocator (N : Node_Id) is - Loc : constant Source_Ptr := Sloc (N); - Sav_Errs : constant Nat := Serious_Errors_Detected; - E : Node_Id := Expression (N); - Acc_Type : Entity_Id; - Type_Id : Entity_Id; - - begin - -- In accordance with H.4(7), the No_Allocators restriction only applies - -- to user-written allocators. - - if Comes_From_Source (N) then - Check_Restriction (No_Allocators, N); - end if; - - if Nkind (E) = N_Qualified_Expression then - Acc_Type := Create_Itype (E_Allocator_Type, N); - Set_Etype (Acc_Type, Acc_Type); - Find_Type (Subtype_Mark (E)); - - -- Analyze the qualified expression, and apply the name resolution - -- rule given in 4.7 (3). - - Analyze (E); - Type_Id := Etype (E); - Set_Directly_Designated_Type (Acc_Type, Type_Id); - - Resolve (Expression (E), Type_Id); - - if Is_Limited_Type (Type_Id) - and then Comes_From_Source (N) - and then not In_Instance_Body - then - if not OK_For_Limited_Init (Expression (E)) then - Error_Msg_N ("initialization not allowed for limited types", N); - Explain_Limited_Type (Type_Id, N); - end if; - end if; - - -- A qualified expression requires an exact match of the type, - -- class-wide matching is not allowed. - - -- if Is_Class_Wide_Type (Type_Id) - -- and then Base_Type - -- (Etype (Expression (E))) /= Base_Type (Type_Id) - -- then - -- Wrong_Type (Expression (E), Type_Id); - -- end if; - - Check_Non_Static_Context (Expression (E)); - - -- We don't analyze the qualified expression itself because it's - -- part of the allocator - - Set_Etype (E, Type_Id); - - -- Case where allocator has a subtype indication - - else - declare - Def_Id : Entity_Id; - Base_Typ : Entity_Id; - - begin - -- If the allocator includes a N_Subtype_Indication then a - -- constraint is present, otherwise the node is a subtype mark. - -- Introduce an explicit subtype declaration into the tree - -- defining some anonymous subtype and rewrite the allocator to - -- use this subtype rather than the subtype indication. - - -- It is important to introduce the explicit subtype declaration - -- so that the bounds of the subtype indication are attached to - -- the tree in case the allocator is inside a generic unit. - - if Nkind (E) = N_Subtype_Indication then - - -- A constraint is only allowed for a composite type in Ada - -- 95. In Ada 83, a constraint is also allowed for an - -- access-to-composite type, but the constraint is ignored. - - Find_Type (Subtype_Mark (E)); - Base_Typ := Entity (Subtype_Mark (E)); - - if Is_Elementary_Type (Base_Typ) then - if not (Ada_Version = Ada_83 - and then Is_Access_Type (Base_Typ)) - then - Error_Msg_N ("constraint not allowed here", E); - - if Nkind (Constraint (E)) = - N_Index_Or_Discriminant_Constraint - then - Error_Msg_N - ("\if qualified expression was meant, " & - "use apostrophe", Constraint (E)); - end if; - end if; - - -- Get rid of the bogus constraint: - - Rewrite (E, New_Copy_Tree (Subtype_Mark (E))); - Analyze_Allocator (N); - return; - - -- Ada 2005, AI-363: if the designated type has a constrained - -- partial view, it cannot receive a discriminant constraint, - -- and the allocated object is unconstrained. - - elsif Ada_Version >= Ada_05 - and then Has_Constrained_Partial_View (Base_Typ) - then - Error_Msg_N - ("constraint no allowed when type " & - "has a constrained partial view", Constraint (E)); - end if; - - if Expander_Active then - Def_Id := - Make_Defining_Identifier (Loc, New_Internal_Name ('S')); - - Insert_Action (E, - Make_Subtype_Declaration (Loc, - Defining_Identifier => Def_Id, - Subtype_Indication => Relocate_Node (E))); - - if Sav_Errs /= Serious_Errors_Detected - and then Nkind (Constraint (E)) = - N_Index_Or_Discriminant_Constraint - then - Error_Msg_N - ("if qualified expression was meant, " & - "use apostrophe!", Constraint (E)); - end if; - - E := New_Occurrence_Of (Def_Id, Loc); - Rewrite (Expression (N), E); - end if; - end if; - - Type_Id := Process_Subtype (E, N); - Acc_Type := Create_Itype (E_Allocator_Type, N); - Set_Etype (Acc_Type, Acc_Type); - Set_Directly_Designated_Type (Acc_Type, Type_Id); - Check_Fully_Declared (Type_Id, N); - - -- Ada 2005 (AI-231): If the designated type is itself an access - -- type that excludes null, its default initialization will - -- be a null object, and we can insert an unconditional raise - -- before the allocator. - - if Can_Never_Be_Null (Type_Id) then - declare - Not_Null_Check : constant Node_Id := - Make_Raise_Constraint_Error (Sloc (E), - Reason => CE_Null_Not_Allowed); - begin - if Expander_Active then - Insert_Action (N, Not_Null_Check); - Analyze (Not_Null_Check); - else - Error_Msg_N ("null value not allowed here?", E); - end if; - end; - end if; - - -- Check restriction against dynamically allocated protected - -- objects. Note that when limited aggregates are supported, - -- a similar test should be applied to an allocator with a - -- qualified expression ??? - - if Is_Protected_Type (Type_Id) then - Check_Restriction (No_Protected_Type_Allocators, N); - end if; - - -- Check for missing initialization. Skip this check if we already - -- had errors on analyzing the allocator, since in that case these - -- are probably cascaded errors. - - if Is_Indefinite_Subtype (Type_Id) - and then Serious_Errors_Detected = Sav_Errs - then - if Is_Class_Wide_Type (Type_Id) then - Error_Msg_N - ("initialization required in class-wide allocation", N); - else - if Ada_Version < Ada_05 - and then Is_Limited_Type (Type_Id) - then - Error_Msg_N ("unconstrained allocation not allowed", N); - - if Is_Array_Type (Type_Id) then - Error_Msg_N - ("\constraint with array bounds required", N); - - elsif Has_Unknown_Discriminants (Type_Id) then - null; - - else pragma Assert (Has_Discriminants (Type_Id)); - Error_Msg_N - ("\constraint with discriminant values required", N); - end if; - - -- Limited Ada 2005 and general non-limited case - - else - Error_Msg_N - ("uninitialized unconstrained allocation not allowed", - N); - - if Is_Array_Type (Type_Id) then - Error_Msg_N - ("\qualified expression or constraint with " & - "array bounds required", N); - - elsif Has_Unknown_Discriminants (Type_Id) then - Error_Msg_N ("\qualified expression required", N); - - else pragma Assert (Has_Discriminants (Type_Id)); - Error_Msg_N - ("\qualified expression or constraint with " & - "discriminant values required", N); - end if; - end if; - end if; - end if; - end; - end if; - - if Is_Abstract_Type (Type_Id) then - Error_Msg_N ("cannot allocate abstract object", E); - end if; - - if Has_Task (Designated_Type (Acc_Type)) then - Check_Restriction (No_Tasking, N); - Check_Restriction (Max_Tasks, N); - Check_Restriction (No_Task_Allocators, N); - end if; - - -- If the No_Streams restriction is set, check that the type of the - -- object is not, and does not contain, any subtype derived from - -- Ada.Streams.Root_Stream_Type. Note that we guard the call to - -- Has_Stream just for efficiency reasons. There is no point in - -- spending time on a Has_Stream check if the restriction is not set. - - if Restrictions.Set (No_Streams) then - if Has_Stream (Designated_Type (Acc_Type)) then - Check_Restriction (No_Streams, N); - end if; - end if; - - Set_Etype (N, Acc_Type); - - if not Is_Library_Level_Entity (Acc_Type) then - Check_Restriction (No_Local_Allocators, N); - end if; - - if Serious_Errors_Detected > Sav_Errs then - Set_Error_Posted (N); - Set_Etype (N, Any_Type); - end if; - end Analyze_Allocator; - - --------------------------- - -- Analyze_Arithmetic_Op -- - --------------------------- - - procedure Analyze_Arithmetic_Op (N : Node_Id) is - L : constant Node_Id := Left_Opnd (N); - R : constant Node_Id := Right_Opnd (N); - Op_Id : Entity_Id; - - begin - Candidate_Type := Empty; - Analyze_Expression (L); - Analyze_Expression (R); - - -- If the entity is already set, the node is the instantiation of a - -- generic node with a non-local reference, or was manufactured by a - -- call to Make_Op_xxx. In either case the entity is known to be valid, - -- and we do not need to collect interpretations, instead we just get - -- the single possible interpretation. - - Op_Id := Entity (N); - - if Present (Op_Id) then - if Ekind (Op_Id) = E_Operator then - - if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem) - and then Treat_Fixed_As_Integer (N) - then - null; - else - Set_Etype (N, Any_Type); - Find_Arithmetic_Types (L, R, Op_Id, N); - end if; - - else - Set_Etype (N, Any_Type); - Add_One_Interp (N, Op_Id, Etype (Op_Id)); - end if; - - -- Entity is not already set, so we do need to collect interpretations - - else - Op_Id := Get_Name_Entity_Id (Chars (N)); - Set_Etype (N, Any_Type); - - while Present (Op_Id) loop - if Ekind (Op_Id) = E_Operator - and then Present (Next_Entity (First_Entity (Op_Id))) - then - Find_Arithmetic_Types (L, R, Op_Id, N); - - -- The following may seem superfluous, because an operator cannot - -- be generic, but this ignores the cleverness of the author of - -- ACVC bc1013a. - - elsif Is_Overloadable (Op_Id) then - Analyze_User_Defined_Binary_Op (N, Op_Id); - end if; - - Op_Id := Homonym (Op_Id); - end loop; - end if; - - Operator_Check (N); - end Analyze_Arithmetic_Op; - - ------------------ - -- Analyze_Call -- - ------------------ - - -- Function, procedure, and entry calls are checked here. The Name in - -- the call may be overloaded. The actuals have been analyzed and may - -- themselves be overloaded. On exit from this procedure, the node N - -- may have zero, one or more interpretations. In the first case an - -- error message is produced. In the last case, the node is flagged - -- as overloaded and the interpretations are collected in All_Interp. - - -- If the name is an Access_To_Subprogram, it cannot be overloaded, but - -- the type-checking is similar to that of other calls. - - procedure Analyze_Call (N : Node_Id) is - Actuals : constant List_Id := Parameter_Associations (N); - Nam : Node_Id; - X : Interp_Index; - It : Interp; - Nam_Ent : Entity_Id; - Success : Boolean := False; - - Deref : Boolean := False; - -- Flag indicates whether an interpretation of the prefix is a - -- parameterless call that returns an access_to_subprogram. - - function Name_Denotes_Function return Boolean; - -- If the type of the name is an access to subprogram, this may be the - -- type of a name, or the return type of the function being called. If - -- the name is not an entity then it can denote a protected function. - -- Until we distinguish Etype from Return_Type, we must use this routine - -- to resolve the meaning of the name in the call. - - procedure No_Interpretation; - -- Output error message when no valid interpretation exists - - --------------------------- - -- Name_Denotes_Function -- - --------------------------- - - function Name_Denotes_Function return Boolean is - begin - if Is_Entity_Name (Nam) then - return Ekind (Entity (Nam)) = E_Function; - - elsif Nkind (Nam) = N_Selected_Component then - return Ekind (Entity (Selector_Name (Nam))) = E_Function; - - else - return False; - end if; - end Name_Denotes_Function; - - ----------------------- - -- No_Interpretation -- - ----------------------- - - procedure No_Interpretation is - L : constant Boolean := Is_List_Member (N); - K : constant Node_Kind := Nkind (Parent (N)); - - begin - -- If the node is in a list whose parent is not an expression then it - -- must be an attempted procedure call. - - if L and then K not in N_Subexpr then - if Ekind (Entity (Nam)) = E_Generic_Procedure then - Error_Msg_NE - ("must instantiate generic procedure& before call", - Nam, Entity (Nam)); - else - Error_Msg_N - ("procedure or entry name expected", Nam); - end if; - - -- Check for tasking cases where only an entry call will do - - elsif not L - and then Nkind_In (K, N_Entry_Call_Alternative, - N_Triggering_Alternative) - then - Error_Msg_N ("entry name expected", Nam); - - -- Otherwise give general error message - - else - Error_Msg_N ("invalid prefix in call", Nam); - end if; - end No_Interpretation; - - -- Start of processing for Analyze_Call - - begin - -- Initialize the type of the result of the call to the error type, - -- which will be reset if the type is successfully resolved. - - Set_Etype (N, Any_Type); - - Nam := Name (N); - - if not Is_Overloaded (Nam) then - - -- Only one interpretation to check - - if Ekind (Etype (Nam)) = E_Subprogram_Type then - Nam_Ent := Etype (Nam); - - -- If the prefix is an access_to_subprogram, this may be an indirect - -- call. This is the case if the name in the call is not an entity - -- name, or if it is a function name in the context of a procedure - -- call. In this latter case, we have a call to a parameterless - -- function that returns a pointer_to_procedure which is the entity - -- being called. Finally, F (X) may be a call to a parameterless - -- function that returns a pointer to a function with parameters. - - elsif Is_Access_Type (Etype (Nam)) - and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type - and then - (not Name_Denotes_Function - or else Nkind (N) = N_Procedure_Call_Statement - or else - (Nkind (Parent (N)) /= N_Explicit_Dereference - and then Is_Entity_Name (Nam) - and then No (First_Formal (Entity (Nam))) - and then Present (Actuals))) - then - Nam_Ent := Designated_Type (Etype (Nam)); - Insert_Explicit_Dereference (Nam); - - -- Selected component case. Simple entry or protected operation, - -- where the entry name is given by the selector name. - - elsif Nkind (Nam) = N_Selected_Component then - Nam_Ent := Entity (Selector_Name (Nam)); - - if Ekind (Nam_Ent) /= E_Entry - and then Ekind (Nam_Ent) /= E_Entry_Family - and then Ekind (Nam_Ent) /= E_Function - and then Ekind (Nam_Ent) /= E_Procedure - then - Error_Msg_N ("name in call is not a callable entity", Nam); - Set_Etype (N, Any_Type); - return; - end if; - - -- If the name is an Indexed component, it can be a call to a member - -- of an entry family. The prefix must be a selected component whose - -- selector is the entry. Analyze_Procedure_Call normalizes several - -- kinds of call into this form. - - elsif Nkind (Nam) = N_Indexed_Component then - if Nkind (Prefix (Nam)) = N_Selected_Component then - Nam_Ent := Entity (Selector_Name (Prefix (Nam))); - else - Error_Msg_N ("name in call is not a callable entity", Nam); - Set_Etype (N, Any_Type); - return; - end if; - - elsif not Is_Entity_Name (Nam) then - Error_Msg_N ("name in call is not a callable entity", Nam); - Set_Etype (N, Any_Type); - return; - - else - Nam_Ent := Entity (Nam); - - -- If no interpretations, give error message - - if not Is_Overloadable (Nam_Ent) then - No_Interpretation; - return; - end if; - end if; - - -- Operations generated for RACW stub types are called only through - -- dispatching, and can never be the static interpretation of a call. - - if Is_RACW_Stub_Type_Operation (Nam_Ent) then - No_Interpretation; - return; - end if; - - Analyze_One_Call (N, Nam_Ent, True, Success); - - -- If this is an indirect call, the return type of the access_to - -- subprogram may be an incomplete type. At the point of the call, - -- use the full type if available, and at the same time update - -- the return type of the access_to_subprogram. - - if Success - and then Nkind (Nam) = N_Explicit_Dereference - and then Ekind (Etype (N)) = E_Incomplete_Type - and then Present (Full_View (Etype (N))) - then - Set_Etype (N, Full_View (Etype (N))); - Set_Etype (Nam_Ent, Etype (N)); - end if; - - else - -- An overloaded selected component must denote overloaded operations - -- of a concurrent type. The interpretations are attached to the - -- simple name of those operations. - - if Nkind (Nam) = N_Selected_Component then - Nam := Selector_Name (Nam); - end if; - - Get_First_Interp (Nam, X, It); - - while Present (It.Nam) loop - Nam_Ent := It.Nam; - Deref := False; - - -- Name may be call that returns an access to subprogram, or more - -- generally an overloaded expression one of whose interpretations - -- yields an access to subprogram. If the name is an entity, we - -- do not dereference, because the node is a call that returns - -- the access type: note difference between f(x), where the call - -- may return an access subprogram type, and f(x)(y), where the - -- type returned by the call to f is implicitly dereferenced to - -- analyze the outer call. - - if Is_Access_Type (Nam_Ent) then - Nam_Ent := Designated_Type (Nam_Ent); - - elsif Is_Access_Type (Etype (Nam_Ent)) - and then - (not Is_Entity_Name (Nam) - or else Nkind (N) = N_Procedure_Call_Statement) - and then Ekind (Designated_Type (Etype (Nam_Ent))) - = E_Subprogram_Type - then - Nam_Ent := Designated_Type (Etype (Nam_Ent)); - - if Is_Entity_Name (Nam) then - Deref := True; - end if; - end if; - - Analyze_One_Call (N, Nam_Ent, False, Success); - - -- If the interpretation succeeds, mark the proper type of the - -- prefix (any valid candidate will do). If not, remove the - -- candidate interpretation. This only needs to be done for - -- overloaded protected operations, for other entities disambi- - -- guation is done directly in Resolve. - - if Success then - if Deref - and then Nkind (Parent (N)) /= N_Explicit_Dereference - then - Set_Entity (Nam, It.Nam); - Insert_Explicit_Dereference (Nam); - Set_Etype (Nam, Nam_Ent); - - else - Set_Etype (Nam, It.Typ); - end if; - - elsif Nkind_In (Name (N), N_Selected_Component, - N_Function_Call) - then - Remove_Interp (X); - end if; - - Get_Next_Interp (X, It); - end loop; - - -- If the name is the result of a function call, it can only - -- be a call to a function returning an access to subprogram. - -- Insert explicit dereference. - - if Nkind (Nam) = N_Function_Call then - Insert_Explicit_Dereference (Nam); - end if; - - if Etype (N) = Any_Type then - - -- None of the interpretations is compatible with the actuals - - Diagnose_Call (N, Nam); - - -- Special checks for uninstantiated put routines - - if Nkind (N) = N_Procedure_Call_Statement - and then Is_Entity_Name (Nam) - and then Chars (Nam) = Name_Put - and then List_Length (Actuals) = 1 - then - declare - Arg : constant Node_Id := First (Actuals); - Typ : Entity_Id; - - begin - if Nkind (Arg) = N_Parameter_Association then - Typ := Etype (Explicit_Actual_Parameter (Arg)); - else - Typ := Etype (Arg); - end if; - - if Is_Signed_Integer_Type (Typ) then - Error_Msg_N - ("possible missing instantiation of " & - "'Text_'I'O.'Integer_'I'O!", Nam); - - elsif Is_Modular_Integer_Type (Typ) then - Error_Msg_N - ("possible missing instantiation of " & - "'Text_'I'O.'Modular_'I'O!", Nam); - - elsif Is_Floating_Point_Type (Typ) then - Error_Msg_N - ("possible missing instantiation of " & - "'Text_'I'O.'Float_'I'O!", Nam); - - elsif Is_Ordinary_Fixed_Point_Type (Typ) then - Error_Msg_N - ("possible missing instantiation of " & - "'Text_'I'O.'Fixed_'I'O!", Nam); - - elsif Is_Decimal_Fixed_Point_Type (Typ) then - Error_Msg_N - ("possible missing instantiation of " & - "'Text_'I'O.'Decimal_'I'O!", Nam); - - elsif Is_Enumeration_Type (Typ) then - Error_Msg_N - ("possible missing instantiation of " & - "'Text_'I'O.'Enumeration_'I'O!", Nam); - end if; - end; - end if; - - elsif not Is_Overloaded (N) - and then Is_Entity_Name (Nam) - then - -- Resolution yields a single interpretation. Verify that the - -- reference has capitalization consistent with the declaration. - - Set_Entity_With_Style_Check (Nam, Entity (Nam)); - Generate_Reference (Entity (Nam), Nam); - - Set_Etype (Nam, Etype (Entity (Nam))); - else - Remove_Abstract_Operations (N); - end if; - - End_Interp_List; - end if; - end Analyze_Call; - - --------------------------- - -- Analyze_Comparison_Op -- - --------------------------- - - procedure Analyze_Comparison_Op (N : Node_Id) is - L : constant Node_Id := Left_Opnd (N); - R : constant Node_Id := Right_Opnd (N); - Op_Id : Entity_Id := Entity (N); - - begin - Set_Etype (N, Any_Type); - Candidate_Type := Empty; - - Analyze_Expression (L); - Analyze_Expression (R); - - if Present (Op_Id) then - if Ekind (Op_Id) = E_Operator then - Find_Comparison_Types (L, R, Op_Id, N); - else - Add_One_Interp (N, Op_Id, Etype (Op_Id)); - end if; - - if Is_Overloaded (L) then - Set_Etype (L, Intersect_Types (L, R)); - end if; - - else - Op_Id := Get_Name_Entity_Id (Chars (N)); - while Present (Op_Id) loop - if Ekind (Op_Id) = E_Operator then - Find_Comparison_Types (L, R, Op_Id, N); - else - Analyze_User_Defined_Binary_Op (N, Op_Id); - end if; - - Op_Id := Homonym (Op_Id); - end loop; - end if; - - Operator_Check (N); - end Analyze_Comparison_Op; - - --------------------------- - -- Analyze_Concatenation -- - --------------------------- - - procedure Analyze_Concatenation (N : Node_Id) is - - -- We wish to avoid deep recursion, because concatenations are often - -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left - -- operands nonrecursively until we find something that is not a - -- concatenation (A in this case), or has already been analyzed. We - -- analyze that, and then walk back up the tree following Parent - -- pointers, calling Analyze_Concatenation_Rest to do the rest of the - -- work at each level. The Parent pointers allow us to avoid recursion, - -- and thus avoid running out of memory. - - NN : Node_Id := N; - L : Node_Id; - - begin - Candidate_Type := Empty; - - -- The following code is equivalent to: - - -- Set_Etype (N, Any_Type); - -- Analyze_Expression (Left_Opnd (N)); - -- Analyze_Concatenation_Rest (N); - - -- where the Analyze_Expression call recurses back here if the left - -- operand is a concatenation. - - -- Walk down left operands - - loop - Set_Etype (NN, Any_Type); - L := Left_Opnd (NN); - exit when Nkind (L) /= N_Op_Concat or else Analyzed (L); - NN := L; - end loop; - - -- Now (given the above example) NN is A&B and L is A - - -- First analyze L ... - - Analyze_Expression (L); - - -- ... then walk NN back up until we reach N (where we started), calling - -- Analyze_Concatenation_Rest along the way. - - loop - Analyze_Concatenation_Rest (NN); - exit when NN = N; - NN := Parent (NN); - end loop; - end Analyze_Concatenation; - - -------------------------------- - -- Analyze_Concatenation_Rest -- - -------------------------------- - - -- If the only one-dimensional array type in scope is String, - -- this is the resulting type of the operation. Otherwise there - -- will be a concatenation operation defined for each user-defined - -- one-dimensional array. - - procedure Analyze_Concatenation_Rest (N : Node_Id) is - L : constant Node_Id := Left_Opnd (N); - R : constant Node_Id := Right_Opnd (N); - Op_Id : Entity_Id := Entity (N); - LT : Entity_Id; - RT : Entity_Id; - - begin - Analyze_Expression (R); - - -- If the entity is present, the node appears in an instance, and - -- denotes a predefined concatenation operation. The resulting type is - -- obtained from the arguments when possible. If the arguments are - -- aggregates, the array type and the concatenation type must be - -- visible. - - if Present (Op_Id) then - if Ekind (Op_Id) = E_Operator then - - LT := Base_Type (Etype (L)); - RT := Base_Type (Etype (R)); - - if Is_Array_Type (LT) - and then (RT = LT or else RT = Base_Type (Component_Type (LT))) - then - Add_One_Interp (N, Op_Id, LT); - - elsif Is_Array_Type (RT) - and then LT = Base_Type (Component_Type (RT)) - then - Add_One_Interp (N, Op_Id, RT); - - -- If one operand is a string type or a user-defined array type, - -- and the other is a literal, result is of the specific type. - - elsif - (Root_Type (LT) = Standard_String - or else Scope (LT) /= Standard_Standard) - and then Etype (R) = Any_String - then - Add_One_Interp (N, Op_Id, LT); - - elsif - (Root_Type (RT) = Standard_String - or else Scope (RT) /= Standard_Standard) - and then Etype (L) = Any_String - then - Add_One_Interp (N, Op_Id, RT); - - elsif not Is_Generic_Type (Etype (Op_Id)) then - Add_One_Interp (N, Op_Id, Etype (Op_Id)); - - else - -- Type and its operations must be visible - - Set_Entity (N, Empty); - Analyze_Concatenation (N); - end if; - - else - Add_One_Interp (N, Op_Id, Etype (Op_Id)); - end if; - - else - Op_Id := Get_Name_Entity_Id (Name_Op_Concat); - while Present (Op_Id) loop - if Ekind (Op_Id) = E_Operator then - - -- Do not consider operators declared in dead code, they can - -- not be part of the resolution. - - if Is_Eliminated (Op_Id) then - null; - else - Find_Concatenation_Types (L, R, Op_Id, N); - end if; - - else - Analyze_User_Defined_Binary_Op (N, Op_Id); - end if; - - Op_Id := Homonym (Op_Id); - end loop; - end if; - - Operator_Check (N); - end Analyze_Concatenation_Rest; - - ------------------------------------ - -- Analyze_Conditional_Expression -- - ------------------------------------ - - procedure Analyze_Conditional_Expression (N : Node_Id) is - Condition : constant Node_Id := First (Expressions (N)); - Then_Expr : constant Node_Id := Next (Condition); - Else_Expr : constant Node_Id := Next (Then_Expr); - begin - Analyze_Expression (Condition); - Analyze_Expression (Then_Expr); - Analyze_Expression (Else_Expr); - Set_Etype (N, Etype (Then_Expr)); - end Analyze_Conditional_Expression; - - ------------------------- - -- Analyze_Equality_Op -- - ------------------------- - - procedure Analyze_Equality_Op (N : Node_Id) is - Loc : constant Source_Ptr := Sloc (N); - L : constant Node_Id := Left_Opnd (N); - R : constant Node_Id := Right_Opnd (N); - Op_Id : Entity_Id; - - begin - Set_Etype (N, Any_Type); - Candidate_Type := Empty; - - Analyze_Expression (L); - Analyze_Expression (R); - - -- If the entity is set, the node is a generic instance with a non-local - -- reference to the predefined operator or to a user-defined function. - -- It can also be an inequality that is expanded into the negation of a - -- call to a user-defined equality operator. - - -- For the predefined case, the result is Boolean, regardless of the - -- type of the operands. The operands may even be limited, if they are - -- generic actuals. If they are overloaded, label the left argument with - -- the common type that must be present, or with the type of the formal - -- of the user-defined function. - - if Present (Entity (N)) then - Op_Id := Entity (N); - - if Ekind (Op_Id) = E_Operator then - Add_One_Interp (N, Op_Id, Standard_Boolean); - else - Add_One_Interp (N, Op_Id, Etype (Op_Id)); - end if; - - if Is_Overloaded (L) then - if Ekind (Op_Id) = E_Operator then - Set_Etype (L, Intersect_Types (L, R)); - else - Set_Etype (L, Etype (First_Formal (Op_Id))); - end if; - end if; - - else - Op_Id := Get_Name_Entity_Id (Chars (N)); - while Present (Op_Id) loop - if Ekind (Op_Id) = E_Operator then - Find_Equality_Types (L, R, Op_Id, N); - else - Analyze_User_Defined_Binary_Op (N, Op_Id); - end if; - - Op_Id := Homonym (Op_Id); - end loop; - end if; - - -- If there was no match, and the operator is inequality, this may - -- be a case where inequality has not been made explicit, as for - -- tagged types. Analyze the node as the negation of an equality - -- operation. This cannot be done earlier, because before analysis - -- we cannot rule out the presence of an explicit inequality. - - if Etype (N) = Any_Type - and then Nkind (N) = N_Op_Ne - then - Op_Id := Get_Name_Entity_Id (Name_Op_Eq); - while Present (Op_Id) loop - if Ekind (Op_Id) = E_Operator then - Find_Equality_Types (L, R, Op_Id, N); - else - Analyze_User_Defined_Binary_Op (N, Op_Id); - end if; - - Op_Id := Homonym (Op_Id); - end loop; - - if Etype (N) /= Any_Type then - Op_Id := Entity (N); - - Rewrite (N, - Make_Op_Not (Loc, - Right_Opnd => - Make_Op_Eq (Loc, - Left_Opnd => Left_Opnd (N), - Right_Opnd => Right_Opnd (N)))); - - Set_Entity (Right_Opnd (N), Op_Id); - Analyze (N); - end if; - end if; - - Operator_Check (N); - end Analyze_Equality_Op; - - ---------------------------------- - -- Analyze_Explicit_Dereference -- - ---------------------------------- - - procedure Analyze_Explicit_Dereference (N : Node_Id) is - Loc : constant Source_Ptr := Sloc (N); - P : constant Node_Id := Prefix (N); - T : Entity_Id; - I : Interp_Index; - It : Interp; - New_N : Node_Id; - - function Is_Function_Type return Boolean; - -- Check whether node may be interpreted as an implicit function call - - ---------------------- - -- Is_Function_Type -- - ---------------------- - - function Is_Function_Type return Boolean is - I : Interp_Index; - It : Interp; - - begin - if not Is_Overloaded (N) then - return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type - and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type; - - else - Get_First_Interp (N, I, It); - while Present (It.Nam) loop - if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type - or else Etype (Base_Type (It.Typ)) = Standard_Void_Type - then - return False; - end if; - - Get_Next_Interp (I, It); - end loop; - - return True; - end if; - end Is_Function_Type; - - -- Start of processing for Analyze_Explicit_Dereference - - begin - Analyze (P); - Set_Etype (N, Any_Type); - - -- Test for remote access to subprogram type, and if so return - -- after rewriting the original tree. - - if Remote_AST_E_Dereference (P) then - return; - end if; - - -- Normal processing for other than remote access to subprogram type - - if not Is_Overloaded (P) then - if Is_Access_Type (Etype (P)) then - - -- Set the Etype. We need to go through Is_For_Access_Subtypes to - -- avoid other problems caused by the Private_Subtype and it is - -- safe to go to the Base_Type because this is the same as - -- converting the access value to its Base_Type. - - declare - DT : Entity_Id := Designated_Type (Etype (P)); - - begin - if Ekind (DT) = E_Private_Subtype - and then Is_For_Access_Subtype (DT) - then - DT := Base_Type (DT); - end if; - - -- An explicit dereference is a legal occurrence of an - -- incomplete type imported through a limited_with clause, - -- if the full view is visible. - - if From_With_Type (DT) - and then not From_With_Type (Scope (DT)) - and then - (Is_Immediately_Visible (Scope (DT)) - or else - (Is_Child_Unit (Scope (DT)) - and then Is_Visible_Child_Unit (Scope (DT)))) - then - Set_Etype (N, Available_View (DT)); - - else - Set_Etype (N, DT); - end if; - end; - - elsif Etype (P) /= Any_Type then - Error_Msg_N ("prefix of dereference must be an access type", N); - return; - end if; - - else - Get_First_Interp (P, I, It); - while Present (It.Nam) loop - T := It.Typ; - - if Is_Access_Type (T) then - Add_One_Interp (N, Designated_Type (T), Designated_Type (T)); - end if; - - Get_Next_Interp (I, It); - end loop; - - -- Error if no interpretation of the prefix has an access type - - if Etype (N) = Any_Type then - Error_Msg_N - ("access type required in prefix of explicit dereference", P); - Set_Etype (N, Any_Type); - return; - end if; - end if; - - if Is_Function_Type - and then Nkind (Parent (N)) /= N_Indexed_Component - - and then (Nkind (Parent (N)) /= N_Function_Call - or else N /= Name (Parent (N))) - - and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement - or else N /= Name (Parent (N))) - - and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration - and then (Nkind (Parent (N)) /= N_Attribute_Reference - or else - (Attribute_Name (Parent (N)) /= Name_Address - and then - Attribute_Name (Parent (N)) /= Name_Access)) - then - -- Name is a function call with no actuals, in a context that - -- requires deproceduring (including as an actual in an enclosing - -- function or procedure call). There are some pathological cases - -- where the prefix might include functions that return access to - -- subprograms and others that return a regular type. Disambiguation - -- of those has to take place in Resolve. - - New_N := - Make_Function_Call (Loc, - Name => Make_Explicit_Dereference (Loc, P), - Parameter_Associations => New_List); - - -- If the prefix is overloaded, remove operations that have formals, - -- we know that this is a parameterless call. - - if Is_Overloaded (P) then - Get_First_Interp (P, I, It); - while Present (It.Nam) loop - T := It.Typ; - - if No (First_Formal (Base_Type (Designated_Type (T)))) then - Set_Etype (P, T); - else - Remove_Interp (I); - end if; - - Get_Next_Interp (I, It); - end loop; - end if; - - Rewrite (N, New_N); - Analyze (N); - - elsif not Is_Function_Type - and then Is_Overloaded (N) - then - -- The prefix may include access to subprograms and other access - -- types. If the context selects the interpretation that is a - -- function call (not a procedure call) we cannot rewrite the node - -- yet, but we include the result of the call interpretation. - - Get_First_Interp (N, I, It); - while Present (It.Nam) loop - if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type - and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type - and then Nkind (Parent (N)) /= N_Procedure_Call_Statement - then - Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ)); - end if; - - Get_Next_Interp (I, It); - end loop; - end if; - - -- A value of remote access-to-class-wide must not be dereferenced - -- (RM E.2.2(16)). - - Validate_Remote_Access_To_Class_Wide_Type (N); - end Analyze_Explicit_Dereference; - - ------------------------ - -- Analyze_Expression -- - ------------------------ - - procedure Analyze_Expression (N : Node_Id) is - begin - Analyze (N); - Check_Parameterless_Call (N); - end Analyze_Expression; - - ------------------------------------ - -- Analyze_Indexed_Component_Form -- - ------------------------------------ - - procedure Analyze_Indexed_Component_Form (N : Node_Id) is - P : constant Node_Id := Prefix (N); - Exprs : constant List_Id := Expressions (N); - Exp : Node_Id; - P_T : Entity_Id; - E : Node_Id; - U_N : Entity_Id; - - procedure Process_Function_Call; - -- Prefix in indexed component form is an overloadable entity, - -- so the node is a function call. Reformat it as such. - - procedure Process_Indexed_Component; - -- Prefix in indexed component form is actually an indexed component. - -- This routine processes it, knowing that the prefix is already - -- resolved. - - procedure Process_Indexed_Component_Or_Slice; - -- An indexed component with a single index may designate a slice if - -- the index is a subtype mark. This routine disambiguates these two - -- cases by resolving the prefix to see if it is a subtype mark. - - procedure Process_Overloaded_Indexed_Component; - -- If the prefix of an indexed component is overloaded, the proper - -- interpretation is selected by the index types and the context. - - --------------------------- - -- Process_Function_Call -- - --------------------------- - - procedure Process_Function_Call is - Actual : Node_Id; - - begin - Change_Node (N, N_Function_Call); - Set_Name (N, P); - Set_Parameter_Associations (N, Exprs); - - -- Analyze actuals prior to analyzing the call itself - - Actual := First (Parameter_Associations (N)); - while Present (Actual) loop - Analyze (Actual); - Check_Parameterless_Call (Actual); - - -- Move to next actual. Note that we use Next, not Next_Actual - -- here. The reason for this is a bit subtle. If a function call - -- includes named associations, the parser recognizes the node as - -- a call, and it is analyzed as such. If all associations are - -- positional, the parser builds an indexed_component node, and - -- it is only after analysis of the prefix that the construct - -- is recognized as a call, in which case Process_Function_Call - -- rewrites the node and analyzes the actuals. If the list of - -- actuals is malformed, the parser may leave the node as an - -- indexed component (despite the presence of named associations). - -- The iterator Next_Actual is equivalent to Next if the list is - -- positional, but follows the normalized chain of actuals when - -- named associations are present. In this case normalization has - -- not taken place, and actuals remain unanalyzed, which leads to - -- subsequent crashes or loops if there is an attempt to continue - -- analysis of the program. - - Next (Actual); - end loop; - - Analyze_Call (N); - end Process_Function_Call; - - ------------------------------- - -- Process_Indexed_Component -- - ------------------------------- - - procedure Process_Indexed_Component is - Exp : Node_Id; - Array_Type : Entity_Id; - Index : Node_Id; - Pent : Entity_Id := Empty; - - begin - Exp := First (Exprs); - - if Is_Overloaded (P) then - Process_Overloaded_Indexed_Component; - - else - Array_Type := Etype (P); - - if Is_Entity_Name (P) then - Pent := Entity (P); - elsif Nkind (P) = N_Selected_Component - and then Is_Entity_Name (Selector_Name (P)) - then - Pent := Entity (Selector_Name (P)); - end if; - - -- Prefix must be appropriate for an array type, taking into - -- account a possible implicit dereference. - - if Is_Access_Type (Array_Type) then - Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); - Array_Type := Process_Implicit_Dereference_Prefix (Pent, P); - end if; - - if Is_Array_Type (Array_Type) then - null; - - elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then - Analyze (Exp); - Set_Etype (N, Any_Type); - - if not Has_Compatible_Type - (Exp, Entry_Index_Type (Pent)) - then - Error_Msg_N ("invalid index type in entry name", N); - - elsif Present (Next (Exp)) then - Error_Msg_N ("too many subscripts in entry reference", N); - - else - Set_Etype (N, Etype (P)); - end if; - - return; - - elsif Is_Record_Type (Array_Type) - and then Remote_AST_I_Dereference (P) - then - return; - - elsif Array_Type = Any_Type then - Set_Etype (N, Any_Type); - return; - - -- Here we definitely have a bad indexing - - else - if Nkind (Parent (N)) = N_Requeue_Statement - and then Present (Pent) and then Ekind (Pent) = E_Entry - then - Error_Msg_N - ("REQUEUE does not permit parameters", First (Exprs)); - - elsif Is_Entity_Name (P) - and then Etype (P) = Standard_Void_Type - then - Error_Msg_NE ("incorrect use of&", P, Entity (P)); - - else - Error_Msg_N ("array type required in indexed component", P); - end if; - - Set_Etype (N, Any_Type); - return; - end if; - - Index := First_Index (Array_Type); - while Present (Index) and then Present (Exp) loop - if not Has_Compatible_Type (Exp, Etype (Index)) then - Wrong_Type (Exp, Etype (Index)); - Set_Etype (N, Any_Type); - return; - end if; - - Next_Index (Index); - Next (Exp); - end loop; - - Set_Etype (N, Component_Type (Array_Type)); - - if Present (Index) then - Error_Msg_N - ("too few subscripts in array reference", First (Exprs)); - - elsif Present (Exp) then - Error_Msg_N ("too many subscripts in array reference", Exp); - end if; - end if; - end Process_Indexed_Component; - - ---------------------------------------- - -- Process_Indexed_Component_Or_Slice -- - ---------------------------------------- - - procedure Process_Indexed_Component_Or_Slice is - begin - Exp := First (Exprs); - while Present (Exp) loop - Analyze_Expression (Exp); - Next (Exp); - end loop; - - Exp := First (Exprs); - - -- If one index is present, and it is a subtype name, then the - -- node denotes a slice (note that the case of an explicit range - -- for a slice was already built as an N_Slice node in the first - -- place, so that case is not handled here). - - -- We use a replace rather than a rewrite here because this is one - -- of the cases in which the tree built by the parser is plain wrong. - - if No (Next (Exp)) - and then Is_Entity_Name (Exp) - and then Is_Type (Entity (Exp)) - then - Replace (N, - Make_Slice (Sloc (N), - Prefix => P, - Discrete_Range => New_Copy (Exp))); - Analyze (N); - - -- Otherwise (more than one index present, or single index is not - -- a subtype name), then we have the indexed component case. - - else - Process_Indexed_Component; - end if; - end Process_Indexed_Component_Or_Slice; - - ------------------------------------------ - -- Process_Overloaded_Indexed_Component -- - ------------------------------------------ - - procedure Process_Overloaded_Indexed_Component is - Exp : Node_Id; - I : Interp_Index; - It : Interp; - Typ : Entity_Id; - Index : Node_Id; - Found : Boolean; - - begin - Set_Etype (N, Any_Type); - - Get_First_Interp (P, I, It); - while Present (It.Nam) loop - Typ := It.Typ; - - if Is_Access_Type (Typ) then - Typ := Designated_Type (Typ); - Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); - end if; - - if Is_Array_Type (Typ) then - - -- Got a candidate: verify that index types are compatible - - Index := First_Index (Typ); - Found := True; - Exp := First (Exprs); - while Present (Index) and then Present (Exp) loop - if Has_Compatible_Type (Exp, Etype (Index)) then - null; - else - Found := False; - Remove_Interp (I); - exit; - end if; - - Next_Index (Index); - Next (Exp); - end loop; - - if Found and then No (Index) and then No (Exp) then - Add_One_Interp (N, - Etype (Component_Type (Typ)), - Etype (Component_Type (Typ))); - end if; - end if; - - Get_Next_Interp (I, It); - end loop; - - if Etype (N) = Any_Type then - Error_Msg_N ("no legal interpretation for indexed component", N); - Set_Is_Overloaded (N, False); - end if; - - End_Interp_List; - end Process_Overloaded_Indexed_Component; - - -- Start of processing for Analyze_Indexed_Component_Form - - begin - -- Get name of array, function or type - - Analyze (P); - - if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then - - -- If P is an explicit dereference whose prefix is of a - -- remote access-to-subprogram type, then N has already - -- been rewritten as a subprogram call and analyzed. - - return; - end if; - - pragma Assert (Nkind (N) = N_Indexed_Component); - - P_T := Base_Type (Etype (P)); - - if Is_Entity_Name (P) - or else Nkind (P) = N_Operator_Symbol - then - U_N := Entity (P); - - if Is_Type (U_N) then - - -- Reformat node as a type conversion - - E := Remove_Head (Exprs); - - if Present (First (Exprs)) then - Error_Msg_N - ("argument of type conversion must be single expression", N); - end if; - - Change_Node (N, N_Type_Conversion); - Set_Subtype_Mark (N, P); - Set_Etype (N, U_N); - Set_Expression (N, E); - - -- After changing the node, call for the specific Analysis - -- routine directly, to avoid a double call to the expander. - - Analyze_Type_Conversion (N); - return; - end if; - - if Is_Overloadable (U_N) then - Process_Function_Call; - - elsif Ekind (Etype (P)) = E_Subprogram_Type - or else (Is_Access_Type (Etype (P)) - and then - Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type) - then - -- Call to access_to-subprogram with possible implicit dereference - - Process_Function_Call; - - elsif Is_Generic_Subprogram (U_N) then - - -- A common beginner's (or C++ templates fan) error - - Error_Msg_N ("generic subprogram cannot be called", N); - Set_Etype (N, Any_Type); - return; - - else - Process_Indexed_Component_Or_Slice; - end if; - - -- If not an entity name, prefix is an expression that may denote - -- an array or an access-to-subprogram. - - else - if Ekind (P_T) = E_Subprogram_Type - or else (Is_Access_Type (P_T) - and then - Ekind (Designated_Type (P_T)) = E_Subprogram_Type) - then - Process_Function_Call; - - elsif Nkind (P) = N_Selected_Component - and then Is_Overloadable (Entity (Selector_Name (P))) - then - Process_Function_Call; - - else - -- Indexed component, slice, or a call to a member of a family - -- entry, which will be converted to an entry call later. - - Process_Indexed_Component_Or_Slice; - end if; - end if; - end Analyze_Indexed_Component_Form; - - ------------------------ - -- Analyze_Logical_Op -- - ------------------------ - - procedure Analyze_Logical_Op (N : Node_Id) is - L : constant Node_Id := Left_Opnd (N); - R : constant Node_Id := Right_Opnd (N); - Op_Id : Entity_Id := Entity (N); - - begin - Set_Etype (N, Any_Type); - Candidate_Type := Empty; - - Analyze_Expression (L); - Analyze_Expression (R); - - if Present (Op_Id) then - - if Ekind (Op_Id) = E_Operator then - Find_Boolean_Types (L, R, Op_Id, N); - else - Add_One_Interp (N, Op_Id, Etype (Op_Id)); - end if; - - else - Op_Id := Get_Name_Entity_Id (Chars (N)); - while Present (Op_Id) loop - if Ekind (Op_Id) = E_Operator then - Find_Boolean_Types (L, R, Op_Id, N); - else - Analyze_User_Defined_Binary_Op (N, Op_Id); - end if; - - Op_Id := Homonym (Op_Id); - end loop; - end if; - - Operator_Check (N); - end Analyze_Logical_Op; - - --------------------------- - -- Analyze_Membership_Op -- - --------------------------- - - procedure Analyze_Membership_Op (N : Node_Id) is - L : constant Node_Id := Left_Opnd (N); - R : constant Node_Id := Right_Opnd (N); - - Index : Interp_Index; - It : Interp; - Found : Boolean := False; - I_F : Interp_Index; - T_F : Entity_Id; - - procedure Try_One_Interp (T1 : Entity_Id); - -- Routine to try one proposed interpretation. Note that the context - -- of the operation plays no role in resolving the arguments, so that - -- if there is more than one interpretation of the operands that is - -- compatible with a membership test, the operation is ambiguous. - - -------------------- - -- Try_One_Interp -- - -------------------- - - procedure Try_One_Interp (T1 : Entity_Id) is - begin - if Has_Compatible_Type (R, T1) then - if Found - and then Base_Type (T1) /= Base_Type (T_F) - then - It := Disambiguate (L, I_F, Index, Any_Type); - - if It = No_Interp then - Ambiguous_Operands (N); - Set_Etype (L, Any_Type); - return; - - else - T_F := It.Typ; - end if; - - else - Found := True; - T_F := T1; - I_F := Index; - end if; - - Set_Etype (L, T_F); - end if; - - end Try_One_Interp; - - -- Start of processing for Analyze_Membership_Op - - begin - Analyze_Expression (L); - - if Nkind (R) = N_Range - or else (Nkind (R) = N_Attribute_Reference - and then Attribute_Name (R) = Name_Range) - then - Analyze (R); - - if not Is_Overloaded (L) then - Try_One_Interp (Etype (L)); - - else - Get_First_Interp (L, Index, It); - while Present (It.Typ) loop - Try_One_Interp (It.Typ); - Get_Next_Interp (Index, It); - end loop; - end if; - - -- If not a range, it can only be a subtype mark, or else there - -- is a more basic error, to be diagnosed in Find_Type. - - else - Find_Type (R); - - if Is_Entity_Name (R) then - Check_Fully_Declared (Entity (R), R); - end if; - end if; - - -- Compatibility between expression and subtype mark or range is - -- checked during resolution. The result of the operation is Boolean - -- in any case. - - Set_Etype (N, Standard_Boolean); - - if Comes_From_Source (N) - and then Is_CPP_Class (Etype (Etype (Right_Opnd (N)))) - then - Error_Msg_N ("membership test not applicable to cpp-class types", N); - end if; - end Analyze_Membership_Op; - - ---------------------- - -- Analyze_Negation -- - ---------------------- - - procedure Analyze_Negation (N : Node_Id) is - R : constant Node_Id := Right_Opnd (N); - Op_Id : Entity_Id := Entity (N); - - begin - Set_Etype (N, Any_Type); - Candidate_Type := Empty; - - Analyze_Expression (R); - - if Present (Op_Id) then - if Ekind (Op_Id) = E_Operator then - Find_Negation_Types (R, Op_Id, N); - else - Add_One_Interp (N, Op_Id, Etype (Op_Id)); - end if; - - else - Op_Id := Get_Name_Entity_Id (Chars (N)); - while Present (Op_Id) loop - if Ekind (Op_Id) = E_Operator then - Find_Negation_Types (R, Op_Id, N); - else - Analyze_User_Defined_Unary_Op (N, Op_Id); - end if; - - Op_Id := Homonym (Op_Id); - end loop; - end if; - - Operator_Check (N); - end Analyze_Negation; - - ------------------ - -- Analyze_Null -- - ------------------ - - procedure Analyze_Null (N : Node_Id) is - begin - Set_Etype (N, Any_Access); - end Analyze_Null; - - ---------------------- - -- Analyze_One_Call -- - ---------------------- - - procedure Analyze_One_Call - (N : Node_Id; - Nam : Entity_Id; - Report : Boolean; - Success : out Boolean; - Skip_First : Boolean := False) - is - Actuals : constant List_Id := Parameter_Associations (N); - Prev_T : constant Entity_Id := Etype (N); - - Must_Skip : constant Boolean := Skip_First - or else Nkind (Original_Node (N)) = N_Selected_Component - or else - (Nkind (Original_Node (N)) = N_Indexed_Component - and then Nkind (Prefix (Original_Node (N))) - = N_Selected_Component); - -- The first formal must be omitted from the match when trying to find - -- a primitive operation that is a possible interpretation, and also - -- after the call has been rewritten, because the corresponding actual - -- is already known to be compatible, and because this may be an - -- indexing of a call with default parameters. - - Formal : Entity_Id; - Actual : Node_Id; - Is_Indexed : Boolean := False; - Is_Indirect : Boolean := False; - Subp_Type : constant Entity_Id := Etype (Nam); - Norm_OK : Boolean; - - function Operator_Hidden_By (Fun : Entity_Id) return Boolean; - -- There may be a user-defined operator that hides the current - -- interpretation. We must check for this independently of the - -- analysis of the call with the user-defined operation, because - -- the parameter names may be wrong and yet the hiding takes place. - -- This fixes a problem with ACATS test B34014O. - -- - -- When the type Address is a visible integer type, and the DEC - -- system extension is visible, the predefined operator may be - -- hidden as well, by one of the address operations in auxdec. - -- Finally, The abstract operations on address do not hide the - -- predefined operator (this is the purpose of making them abstract). - - procedure Indicate_Name_And_Type; - -- If candidate interpretation matches, indicate name and type of - -- result on call node. - - ---------------------------- - -- Indicate_Name_And_Type -- - ---------------------------- - - procedure Indicate_Name_And_Type is - begin - Add_One_Interp (N, Nam, Etype (Nam)); - Success := True; - - -- If the prefix of the call is a name, indicate the entity - -- being called. If it is not a name, it is an expression that - -- denotes an access to subprogram or else an entry or family. In - -- the latter case, the name is a selected component, and the entity - -- being called is noted on the selector. - - if not Is_Type (Nam) then - if Is_Entity_Name (Name (N)) - or else Nkind (Name (N)) = N_Operator_Symbol - then - Set_Entity (Name (N), Nam); - - elsif Nkind (Name (N)) = N_Selected_Component then - Set_Entity (Selector_Name (Name (N)), Nam); - end if; - end if; - - if Debug_Flag_E and not Report then - Write_Str (" Overloaded call "); - Write_Int (Int (N)); - Write_Str (" compatible with "); - Write_Int (Int (Nam)); - Write_Eol; - end if; - end Indicate_Name_And_Type; - - ------------------------ - -- Operator_Hidden_By -- - ------------------------ - - function Operator_Hidden_By (Fun : Entity_Id) return Boolean is - Act1 : constant Node_Id := First_Actual (N); - Act2 : constant Node_Id := Next_Actual (Act1); - Form1 : constant Entity_Id := First_Formal (Fun); - Form2 : constant Entity_Id := Next_Formal (Form1); - - begin - if Ekind (Fun) /= E_Function - or else Is_Abstract_Subprogram (Fun) - then - return False; - - elsif not Has_Compatible_Type (Act1, Etype (Form1)) then - return False; - - elsif Present (Form2) then - if - No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2)) - then - return False; - end if; - - elsif Present (Act2) then - return False; - end if; - - -- Now we know that the arity of the operator matches the function, - -- and the function call is a valid interpretation. The function - -- hides the operator if it has the right signature, or if one of - -- its operands is a non-abstract operation on Address when this is - -- a visible integer type. - - return Hides_Op (Fun, Nam) - or else Is_Descendent_Of_Address (Etype (Form1)) - or else - (Present (Form2) - and then Is_Descendent_Of_Address (Etype (Form2))); - end Operator_Hidden_By; - - -- Start of processing for Analyze_One_Call - - begin - Success := False; - - -- If the subprogram has no formals or if all the formals have defaults, - -- and the return type is an array type, the node may denote an indexing - -- of the result of a parameterless call. In Ada 2005, the subprogram - -- may have one non-defaulted formal, and the call may have been written - -- in prefix notation, so that the rebuilt parameter list has more than - -- one actual. - - if not Is_Overloadable (Nam) - and then Ekind (Nam) /= E_Subprogram_Type - and then Ekind (Nam) /= E_Entry_Family - then - return; - end if; - - if Present (Actuals) - and then - (Needs_No_Actuals (Nam) - or else - (Needs_One_Actual (Nam) - and then Present (Next_Actual (First (Actuals))))) - then - if Is_Array_Type (Subp_Type) then - Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip); - - elsif Is_Access_Type (Subp_Type) - and then Is_Array_Type (Designated_Type (Subp_Type)) - then - Is_Indexed := - Try_Indexed_Call - (N, Nam, Designated_Type (Subp_Type), Must_Skip); - - -- The prefix can also be a parameterless function that returns an - -- access to subprogram, in which case this is an indirect call. - -- If this succeeds, an explicit dereference is added later on, - -- in Analyze_Call or Resolve_Call. - - elsif Is_Access_Type (Subp_Type) - and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type - then - Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type); - end if; - - end if; - - -- If the call has been transformed into a slice, it is of the form - -- F (Subtype) where F is parameterless. The node has been rewritten in - -- Try_Indexed_Call and there is nothing else to do. - - if Is_Indexed - and then Nkind (N) = N_Slice - then - return; - end if; - - Normalize_Actuals - (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK); - - if not Norm_OK then - - -- If an indirect call is a possible interpretation, indicate - -- success to the caller. - - if Is_Indirect then - Success := True; - return; - - -- Mismatch in number or names of parameters - - elsif Debug_Flag_E then - Write_Str (" normalization fails in call "); - Write_Int (Int (N)); - Write_Str (" with subprogram "); - Write_Int (Int (Nam)); - Write_Eol; - end if; - - -- If the context expects a function call, discard any interpretation - -- that is a procedure. If the node is not overloaded, leave as is for - -- better error reporting when type mismatch is found. - - elsif Nkind (N) = N_Function_Call - and then Is_Overloaded (Name (N)) - and then Ekind (Nam) = E_Procedure - then - return; - - -- Ditto for function calls in a procedure context - - elsif Nkind (N) = N_Procedure_Call_Statement - and then Is_Overloaded (Name (N)) - and then Etype (Nam) /= Standard_Void_Type - then - return; - - elsif No (Actuals) then - - -- If Normalize succeeds, then there are default parameters for - -- all formals. - - Indicate_Name_And_Type; - - elsif Ekind (Nam) = E_Operator then - if Nkind (N) = N_Procedure_Call_Statement then - return; - end if; - - -- This can occur when the prefix of the call is an operator - -- name or an expanded name whose selector is an operator name. - - Analyze_Operator_Call (N, Nam); - - if Etype (N) /= Prev_T then - - -- Check that operator is not hidden by a function interpretation - - if Is_Overloaded (Name (N)) then - declare - I : Interp_Index; - It : Interp; - - begin - Get_First_Interp (Name (N), I, It); - while Present (It.Nam) loop - if Operator_Hidden_By (It.Nam) then - Set_Etype (N, Prev_T); - return; - end if; - - Get_Next_Interp (I, It); - end loop; - end; - end if; - - -- If operator matches formals, record its name on the call. - -- If the operator is overloaded, Resolve will select the - -- correct one from the list of interpretations. The call - -- node itself carries the first candidate. - - Set_Entity (Name (N), Nam); - Success := True; - - elsif Report and then Etype (N) = Any_Type then - Error_Msg_N ("incompatible arguments for operator", N); - end if; - - else - -- Normalize_Actuals has chained the named associations in the - -- correct order of the formals. - - Actual := First_Actual (N); - Formal := First_Formal (Nam); - - -- If we are analyzing a call rewritten from object notation, - -- skip first actual, which may be rewritten later as an - -- explicit dereference. - - if Must_Skip then - Next_Actual (Actual); - Next_Formal (Formal); - end if; - - while Present (Actual) and then Present (Formal) loop - if Nkind (Parent (Actual)) /= N_Parameter_Association - or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal) - then - -- The actual can be compatible with the formal, but we must - -- also check that the context is not an address type that is - -- visibly an integer type, as is the case in VMS_64. In this - -- case the use of literals is illegal, except in the body of - -- descendents of system, where arithmetic operations on - -- address are of course used. - - if Has_Compatible_Type (Actual, Etype (Formal)) - and then - (Etype (Actual) /= Universal_Integer - or else not Is_Descendent_Of_Address (Etype (Formal)) - or else - Is_Predefined_File_Name - (Unit_File_Name (Get_Source_Unit (N)))) - then - Next_Actual (Actual); - Next_Formal (Formal); - - else - if Debug_Flag_E then - Write_Str (" type checking fails in call "); - Write_Int (Int (N)); - Write_Str (" with formal "); - Write_Int (Int (Formal)); - Write_Str (" in subprogram "); - Write_Int (Int (Nam)); - Write_Eol; - end if; - - if Report and not Is_Indexed and not Is_Indirect then - - -- Ada 2005 (AI-251): Complete the error notification - -- to help new Ada 2005 users - - if Is_Class_Wide_Type (Etype (Formal)) - and then Is_Interface (Etype (Etype (Formal))) - and then not Interface_Present_In_Ancestor - (Typ => Etype (Actual), - Iface => Etype (Etype (Formal))) - then - Error_Msg_NE - ("(Ada 2005) does not implement interface }", - Actual, Etype (Etype (Formal))); - end if; - - Wrong_Type (Actual, Etype (Formal)); - - if Nkind (Actual) = N_Op_Eq - and then Nkind (Left_Opnd (Actual)) = N_Identifier - then - Formal := First_Formal (Nam); - while Present (Formal) loop - if Chars (Left_Opnd (Actual)) = Chars (Formal) then - Error_Msg_N - ("possible misspelling of `='>`!", Actual); - exit; - end if; - - Next_Formal (Formal); - end loop; - end if; - - if All_Errors_Mode then - Error_Msg_Sloc := Sloc (Nam); - - if Is_Overloadable (Nam) - and then Present (Alias (Nam)) - and then not Comes_From_Source (Nam) - then - Error_Msg_NE - ("\\ =='> in call to inherited operation & #!", - Actual, Nam); - - elsif Ekind (Nam) = E_Subprogram_Type then - declare - Access_To_Subprogram_Typ : - constant Entity_Id := - Defining_Identifier - (Associated_Node_For_Itype (Nam)); - begin - Error_Msg_NE ( - "\\ =='> in call to dereference of &#!", - Actual, Access_To_Subprogram_Typ); - end; - - else - Error_Msg_NE - ("\\ =='> in call to &#!", Actual, Nam); - - end if; - end if; - end if; - - return; - end if; - - else - -- Normalize_Actuals has verified that a default value exists - -- for this formal. Current actual names a subsequent formal. - - Next_Formal (Formal); - end if; - end loop; - - -- On exit, all actuals match - - Indicate_Name_And_Type; - end if; - end Analyze_One_Call; - - --------------------------- - -- Analyze_Operator_Call -- - --------------------------- - - procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is - Op_Name : constant Name_Id := Chars (Op_Id); - Act1 : constant Node_Id := First_Actual (N); - Act2 : constant Node_Id := Next_Actual (Act1); - - begin - -- Binary operator case - - if Present (Act2) then - - -- If more than two operands, then not binary operator after all - - if Present (Next_Actual (Act2)) then - return; - - elsif Op_Name = Name_Op_Add - or else Op_Name = Name_Op_Subtract - or else Op_Name = Name_Op_Multiply - or else Op_Name = Name_Op_Divide - or else Op_Name = Name_Op_Mod - or else Op_Name = Name_Op_Rem - or else Op_Name = Name_Op_Expon - then - Find_Arithmetic_Types (Act1, Act2, Op_Id, N); - - elsif Op_Name = Name_Op_And - or else Op_Name = Name_Op_Or - or else Op_Name = Name_Op_Xor - then - Find_Boolean_Types (Act1, Act2, Op_Id, N); - - elsif Op_Name = Name_Op_Lt - or else Op_Name = Name_Op_Le - or else Op_Name = Name_Op_Gt - or else Op_Name = Name_Op_Ge - then - Find_Comparison_Types (Act1, Act2, Op_Id, N); - - elsif Op_Name = Name_Op_Eq - or else Op_Name = Name_Op_Ne - then - Find_Equality_Types (Act1, Act2, Op_Id, N); - - elsif Op_Name = Name_Op_Concat then - Find_Concatenation_Types (Act1, Act2, Op_Id, N); - - -- Is this else null correct, or should it be an abort??? - - else - null; - end if; - - -- Unary operator case - - else - if Op_Name = Name_Op_Subtract or else - Op_Name = Name_Op_Add or else - Op_Name = Name_Op_Abs - then - Find_Unary_Types (Act1, Op_Id, N); - - elsif - Op_Name = Name_Op_Not - then - Find_Negation_Types (Act1, Op_Id, N); - - -- Is this else null correct, or should it be an abort??? - - else - null; - end if; - end if; - end Analyze_Operator_Call; - - ------------------------------------------- - -- Analyze_Overloaded_Selected_Component -- - ------------------------------------------- - - procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is - Nam : constant Node_Id := Prefix (N); - Sel : constant Node_Id := Selector_Name (N); - Comp : Entity_Id; - I : Interp_Index; - It : Interp; - T : Entity_Id; - - begin - Set_Etype (Sel, Any_Type); - - Get_First_Interp (Nam, I, It); - while Present (It.Typ) loop - if Is_Access_Type (It.Typ) then - T := Designated_Type (It.Typ); - Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); - else - T := It.Typ; - end if; - - if Is_Record_Type (T) then - - -- If the prefix is a class-wide type, the visible components are - -- those of the base type. - - if Is_Class_Wide_Type (T) then - T := Etype (T); - end if; - - Comp := First_Entity (T); - while Present (Comp) loop - if Chars (Comp) = Chars (Sel) - and then Is_Visible_Component (Comp) - then - Set_Entity (Sel, Comp); - Set_Etype (Sel, Etype (Comp)); - Add_One_Interp (N, Etype (Comp), Etype (Comp)); - - -- This also specifies a candidate to resolve the name. - -- Further overloading will be resolved from context. - - Set_Etype (Nam, It.Typ); - end if; - - Next_Entity (Comp); - end loop; - - elsif Is_Concurrent_Type (T) then - Comp := First_Entity (T); - while Present (Comp) - and then Comp /= First_Private_Entity (T) - loop - if Chars (Comp) = Chars (Sel) then - if Is_Overloadable (Comp) then - Add_One_Interp (Sel, Comp, Etype (Comp)); - else - Set_Entity_With_Style_Check (Sel, Comp); - Generate_Reference (Comp, Sel); - end if; - - Set_Etype (Sel, Etype (Comp)); - Set_Etype (N, Etype (Comp)); - Set_Etype (Nam, It.Typ); - - -- For access type case, introduce explicit deference for - -- more uniform treatment of entry calls. Do this only - -- once if several interpretations yield an access type. - - if Is_Access_Type (Etype (Nam)) - and then Nkind (Nam) /= N_Explicit_Dereference - then - Insert_Explicit_Dereference (Nam); - Error_Msg_NW - (Warn_On_Dereference, "?implicit dereference", N); - end if; - end if; - - Next_Entity (Comp); - end loop; - - Set_Is_Overloaded (N, Is_Overloaded (Sel)); - end if; - - Get_Next_Interp (I, It); - end loop; - - if Etype (N) = Any_Type - and then not Try_Object_Operation (N) - then - Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel); - Set_Entity (Sel, Any_Id); - Set_Etype (Sel, Any_Type); - end if; - end Analyze_Overloaded_Selected_Component; - - ---------------------------------- - -- Analyze_Qualified_Expression -- - ---------------------------------- - - procedure Analyze_Qualified_Expression (N : Node_Id) is - Mark : constant Entity_Id := Subtype_Mark (N); - Expr : constant Node_Id := Expression (N); - I : Interp_Index; - It : Interp; - T : Entity_Id; - - begin - Analyze_Expression (Expr); - - Set_Etype (N, Any_Type); - Find_Type (Mark); - T := Entity (Mark); - Set_Etype (N, T); - - if T = Any_Type then - return; - end if; - - Check_Fully_Declared (T, N); - - -- If expected type is class-wide, check for exact match before - -- expansion, because if the expression is a dispatching call it - -- may be rewritten as explicit dereference with class-wide result. - -- If expression is overloaded, retain only interpretations that - -- will yield exact matches. - - if Is_Class_Wide_Type (T) then - if not Is_Overloaded (Expr) then - if Base_Type (Etype (Expr)) /= Base_Type (T) then - if Nkind (Expr) = N_Aggregate then - Error_Msg_N ("type of aggregate cannot be class-wide", Expr); - else - Wrong_Type (Expr, T); - end if; - end if; - - else - Get_First_Interp (Expr, I, It); - - while Present (It.Nam) loop - if Base_Type (It.Typ) /= Base_Type (T) then - Remove_Interp (I); - end if; - - Get_Next_Interp (I, It); - end loop; - end if; - end if; - - Set_Etype (N, T); - end Analyze_Qualified_Expression; - - ------------------- - -- Analyze_Range -- - ------------------- - - procedure Analyze_Range (N : Node_Id) is - L : constant Node_Id := Low_Bound (N); - H : constant Node_Id := High_Bound (N); - I1, I2 : Interp_Index; - It1, It2 : Interp; - - procedure Check_Common_Type (T1, T2 : Entity_Id); - -- Verify the compatibility of two types, and choose the - -- non universal one if the other is universal. - - procedure Check_High_Bound (T : Entity_Id); - -- Test one interpretation of the low bound against all those - -- of the high bound. - - procedure Check_Universal_Expression (N : Node_Id); - -- In Ada83, reject bounds of a universal range that are not - -- literals or entity names. - - ----------------------- - -- Check_Common_Type -- - ----------------------- - - procedure Check_Common_Type (T1, T2 : Entity_Id) is - begin - if Covers (T1 => T1, T2 => T2) - or else - Covers (T1 => T2, T2 => T1) - then - if T1 = Universal_Integer - or else T1 = Universal_Real - or else T1 = Any_Character - then - Add_One_Interp (N, Base_Type (T2), Base_Type (T2)); - - elsif T1 = T2 then - Add_One_Interp (N, T1, T1); - - else - Add_One_Interp (N, Base_Type (T1), Base_Type (T1)); - end if; - end if; - end Check_Common_Type; - - ---------------------- - -- Check_High_Bound -- - ---------------------- - - procedure Check_High_Bound (T : Entity_Id) is - begin - if not Is_Overloaded (H) then - Check_Common_Type (T, Etype (H)); - else - Get_First_Interp (H, I2, It2); - while Present (It2.Typ) loop - Check_Common_Type (T, It2.Typ); - Get_Next_Interp (I2, It2); - end loop; - end if; - end Check_High_Bound; - - ----------------------------- - -- Is_Universal_Expression -- - ----------------------------- - - procedure Check_Universal_Expression (N : Node_Id) is - begin - if Etype (N) = Universal_Integer - and then Nkind (N) /= N_Integer_Literal - and then not Is_Entity_Name (N) - and then Nkind (N) /= N_Attribute_Reference - then - Error_Msg_N ("illegal bound in discrete range", N); - end if; - end Check_Universal_Expression; - - -- Start of processing for Analyze_Range - - begin - Set_Etype (N, Any_Type); - Analyze_Expression (L); - Analyze_Expression (H); - - if Etype (L) = Any_Type or else Etype (H) = Any_Type then - return; - - else - if not Is_Overloaded (L) then - Check_High_Bound (Etype (L)); - else - Get_First_Interp (L, I1, It1); - while Present (It1.Typ) loop - Check_High_Bound (It1.Typ); - Get_Next_Interp (I1, It1); - end loop; - end if; - - -- If result is Any_Type, then we did not find a compatible pair - - if Etype (N) = Any_Type then - Error_Msg_N ("incompatible types in range ", N); - end if; - end if; - - if Ada_Version = Ada_83 - and then - (Nkind (Parent (N)) = N_Loop_Parameter_Specification - or else Nkind (Parent (N)) = N_Constrained_Array_Definition) - then - Check_Universal_Expression (L); - Check_Universal_Expression (H); - end if; - end Analyze_Range; - - ----------------------- - -- Analyze_Reference -- - ----------------------- - - procedure Analyze_Reference (N : Node_Id) is - P : constant Node_Id := Prefix (N); - E : Entity_Id; - T : Entity_Id; - Acc_Type : Entity_Id; - - begin - Analyze (P); - - -- An interesting error check, if we take the 'Reference of an object - -- for which a pragma Atomic or Volatile has been given, and the type - -- of the object is not Atomic or Volatile, then we are in trouble. The - -- problem is that no trace of the atomic/volatile status will remain - -- for the backend to respect when it deals with the resulting pointer, - -- since the pointer type will not be marked atomic (it is a pointer to - -- the base type of the object). - - -- It is not clear if that can ever occur, but in case it does, we will - -- generate an error message. Not clear if this message can ever be - -- generated, and pretty clear that it represents a bug if it is, still - -- seems worth checking! - - T := Etype (P); - - if Is_Entity_Name (P) - and then Is_Object_Reference (P) - then - E := Entity (P); - T := Etype (P); - - if (Has_Atomic_Components (E) - and then not Has_Atomic_Components (T)) - or else - (Has_Volatile_Components (E) - and then not Has_Volatile_Components (T)) - or else (Is_Atomic (E) and then not Is_Atomic (T)) - or else (Is_Volatile (E) and then not Is_Volatile (T)) - then - Error_Msg_N ("cannot take reference to Atomic/Volatile object", N); - end if; - end if; - - -- Carry on with normal processing - - Acc_Type := Create_Itype (E_Allocator_Type, N); - Set_Etype (Acc_Type, Acc_Type); - Set_Directly_Designated_Type (Acc_Type, Etype (P)); - Set_Etype (N, Acc_Type); - end Analyze_Reference; - - -------------------------------- - -- Analyze_Selected_Component -- - -------------------------------- - - -- Prefix is a record type or a task or protected type. In the - -- later case, the selector must denote a visible entry. - - procedure Analyze_Selected_Component (N : Node_Id) is - Name : constant Node_Id := Prefix (N); - Sel : constant Node_Id := Selector_Name (N); - Act_Decl : Node_Id; - Comp : Entity_Id; - Has_Candidate : Boolean := False; - In_Scope : Boolean; - Parent_N : Node_Id; - Pent : Entity_Id := Empty; - Prefix_Type : Entity_Id; - - Type_To_Use : Entity_Id; - -- In most cases this is the Prefix_Type, but if the Prefix_Type is - -- a class-wide type, we use its root type, whose components are - -- present in the class-wide type. - - function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean; - -- It is known that the parent of N denotes a subprogram call. Comp - -- is an overloadable component of the concurrent type of the prefix. - -- Determine whether all formals of the parent of N and Comp are mode - -- conformant. If the parent node is not analyzed yet it may be an - -- indexed component rather than a function call. - - ------------------------------ - -- Has_Mode_Conformant_Spec -- - ------------------------------ - - function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is - Comp_Param : Entity_Id; - Param : Node_Id; - Param_Typ : Entity_Id; - - begin - Comp_Param := First_Formal (Comp); - - if Nkind (Parent (N)) = N_Indexed_Component then - Param := First (Expressions (Parent (N))); - else - Param := First (Parameter_Associations (Parent (N))); - end if; - - while Present (Comp_Param) - and then Present (Param) - loop - Param_Typ := Find_Parameter_Type (Param); - - if Present (Param_Typ) - and then - not Conforming_Types - (Etype (Comp_Param), Param_Typ, Mode_Conformant) - then - return False; - end if; - - Next_Formal (Comp_Param); - Next (Param); - end loop; - - -- One of the specs has additional formals - - if Present (Comp_Param) or else Present (Param) then - return False; - end if; - - return True; - end Has_Mode_Conformant_Spec; - - -- Start of processing for Analyze_Selected_Component - - begin - Set_Etype (N, Any_Type); - - if Is_Overloaded (Name) then - Analyze_Overloaded_Selected_Component (N); - return; - - elsif Etype (Name) = Any_Type then - Set_Entity (Sel, Any_Id); - Set_Etype (Sel, Any_Type); - return; - - else - Prefix_Type := Etype (Name); - end if; - - if Is_Access_Type (Prefix_Type) then - - -- A RACW object can never be used as prefix of a selected - -- component since that means it is dereferenced without - -- being a controlling operand of a dispatching operation - -- (RM E.2.2(16/1)). Before reporting an error, we must check - -- whether this is actually a dispatching call in prefix form. - - if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type) - and then Comes_From_Source (N) - then - if Try_Object_Operation (N) then - return; - else - Error_Msg_N - ("invalid dereference of a remote access-to-class-wide value", - N); - end if; - - -- Normal case of selected component applied to access type - - else - Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); - - if Is_Entity_Name (Name) then - Pent := Entity (Name); - elsif Nkind (Name) = N_Selected_Component - and then Is_Entity_Name (Selector_Name (Name)) - then - Pent := Entity (Selector_Name (Name)); - end if; - - Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name); - end if; - - -- If we have an explicit dereference of a remote access-to-class-wide - -- value, then issue an error (see RM-E.2.2(16/1)). However we first - -- have to check for the case of a prefix that is a controlling operand - -- of a prefixed dispatching call, as the dereference is legal in that - -- case. Normally this condition is checked in Validate_Remote_Access_ - -- To_Class_Wide_Type, but we have to defer the checking for selected - -- component prefixes because of the prefixed dispatching call case. - -- Note that implicit dereferences are checked for this just above. - - elsif Nkind (Name) = N_Explicit_Dereference - and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name))) - and then Comes_From_Source (N) - then - if Try_Object_Operation (N) then - return; - else - Error_Msg_N - ("invalid dereference of a remote access-to-class-wide value", - N); - end if; - end if; - - -- (Ada 2005): if the prefix is the limited view of a type, and - -- the context already includes the full view, use the full view - -- in what follows, either to retrieve a component of to find - -- a primitive operation. If the prefix is an explicit dereference, - -- set the type of the prefix to reflect this transformation. - -- If the non-limited view is itself an incomplete type, get the - -- full view if available. - - if Is_Incomplete_Type (Prefix_Type) - and then From_With_Type (Prefix_Type) - and then Present (Non_Limited_View (Prefix_Type)) - then - Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type)); - - if Nkind (N) = N_Explicit_Dereference then - Set_Etype (Prefix (N), Prefix_Type); - end if; - - elsif Ekind (Prefix_Type) = E_Class_Wide_Type - and then From_With_Type (Prefix_Type) - and then Present (Non_Limited_View (Etype (Prefix_Type))) - then - Prefix_Type := - Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type))); - - if Nkind (N) = N_Explicit_Dereference then - Set_Etype (Prefix (N), Prefix_Type); - end if; - end if; - - if Ekind (Prefix_Type) = E_Private_Subtype then - Prefix_Type := Base_Type (Prefix_Type); - end if; - - Type_To_Use := Prefix_Type; - - -- For class-wide types, use the entity list of the root type. This - -- indirection is specially important for private extensions because - -- only the root type get switched (not the class-wide type). - - if Is_Class_Wide_Type (Prefix_Type) then - Type_To_Use := Root_Type (Prefix_Type); - end if; - - Comp := First_Entity (Type_To_Use); - - -- If the selector has an original discriminant, the node appears in - -- an instance. Replace the discriminant with the corresponding one - -- in the current discriminated type. For nested generics, this must - -- be done transitively, so note the new original discriminant. - - if Nkind (Sel) = N_Identifier - and then Present (Original_Discriminant (Sel)) - then - Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type); - - -- Mark entity before rewriting, for completeness and because - -- subsequent semantic checks might examine the original node. - - Set_Entity (Sel, Comp); - Rewrite (Selector_Name (N), - New_Occurrence_Of (Comp, Sloc (N))); - Set_Original_Discriminant (Selector_Name (N), Comp); - Set_Etype (N, Etype (Comp)); - - if Is_Access_Type (Etype (Name)) then - Insert_Explicit_Dereference (Name); - Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); - end if; - - elsif Is_Record_Type (Prefix_Type) then - - -- Find component with given name - - while Present (Comp) loop - if Chars (Comp) = Chars (Sel) - and then Is_Visible_Component (Comp) - then - Set_Entity_With_Style_Check (Sel, Comp); - Set_Etype (Sel, Etype (Comp)); - - if Ekind (Comp) = E_Discriminant then - if Is_Unchecked_Union (Base_Type (Prefix_Type)) then - Error_Msg_N - ("cannot reference discriminant of Unchecked_Union", - Sel); - end if; - - if Is_Generic_Type (Prefix_Type) - or else - Is_Generic_Type (Root_Type (Prefix_Type)) - then - Set_Original_Discriminant (Sel, Comp); - end if; - end if; - - -- Resolve the prefix early otherwise it is not possible to - -- build the actual subtype of the component: it may need - -- to duplicate this prefix and duplication is only allowed - -- on fully resolved expressions. - - Resolve (Name); - - -- Ada 2005 (AI-50217): Check wrong use of incomplete types or - -- subtypes in a package specification. - -- Example: - - -- limited with Pkg; - -- package Pkg is - -- type Acc_Inc is access Pkg.T; - -- X : Acc_Inc; - -- N : Natural := X.all.Comp; -- ERROR, limited view - -- end Pkg; -- Comp is not visible - - if Nkind (Name) = N_Explicit_Dereference - and then From_With_Type (Etype (Prefix (Name))) - and then not Is_Potentially_Use_Visible (Etype (Name)) - and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) = - N_Package_Specification - then - Error_Msg_NE - ("premature usage of incomplete}", Prefix (Name), - Etype (Prefix (Name))); - end if; - - -- We never need an actual subtype for the case of a selection - -- for a indexed component of a non-packed array, since in - -- this case gigi generates all the checks and can find the - -- necessary bounds information. - - -- We also do not need an actual subtype for the case of - -- a first, last, length, or range attribute applied to a - -- non-packed array, since gigi can again get the bounds in - -- these cases (gigi cannot handle the packed case, since it - -- has the bounds of the packed array type, not the original - -- bounds of the type). However, if the prefix is itself a - -- selected component, as in a.b.c (i), gigi may regard a.b.c - -- as a dynamic-sized temporary, so we do generate an actual - -- subtype for this case. - - Parent_N := Parent (N); - - if not Is_Packed (Etype (Comp)) - and then - ((Nkind (Parent_N) = N_Indexed_Component - and then Nkind (Name) /= N_Selected_Component) - or else - (Nkind (Parent_N) = N_Attribute_Reference - and then (Attribute_Name (Parent_N) = Name_First - or else - Attribute_Name (Parent_N) = Name_Last - or else - Attribute_Name (Parent_N) = Name_Length - or else - Attribute_Name (Parent_N) = Name_Range))) - then - Set_Etype (N, Etype (Comp)); - - -- If full analysis is not enabled, we do not generate an - -- actual subtype, because in the absence of expansion - -- reference to a formal of a protected type, for example, - -- will not be properly transformed, and will lead to - -- out-of-scope references in gigi. - - -- In all other cases, we currently build an actual subtype. - -- It seems likely that many of these cases can be avoided, - -- but right now, the front end makes direct references to the - -- bounds (e.g. in generating a length check), and if we do - -- not make an actual subtype, we end up getting a direct - -- reference to a discriminant, which will not do. - - elsif Full_Analysis then - Act_Decl := - Build_Actual_Subtype_Of_Component (Etype (Comp), N); - Insert_Action (N, Act_Decl); - - if No (Act_Decl) then - Set_Etype (N, Etype (Comp)); - - else - -- Component type depends on discriminants. Enter the - -- main attributes of the subtype. - - declare - Subt : constant Entity_Id := - Defining_Identifier (Act_Decl); - - begin - Set_Etype (Subt, Base_Type (Etype (Comp))); - Set_Ekind (Subt, Ekind (Etype (Comp))); - Set_Etype (N, Subt); - end; - end if; - - -- If Full_Analysis not enabled, just set the Etype - - else - Set_Etype (N, Etype (Comp)); - end if; - - return; - end if; - - -- If the prefix is a private extension, check only the visible - -- components of the partial view. This must include the tag, - -- which can appear in expanded code in a tag check. - - if Ekind (Type_To_Use) = E_Record_Type_With_Private - and then Chars (Selector_Name (N)) /= Name_uTag - then - exit when Comp = Last_Entity (Type_To_Use); - end if; - - Next_Entity (Comp); - end loop; - - -- Ada 2005 (AI-252): The selected component can be interpreted as - -- a prefixed view of a subprogram. Depending on the context, this is - -- either a name that can appear in a renaming declaration, or part - -- of an enclosing call given in prefix form. - - -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the - -- selected component should resolve to a name. - - if Ada_Version >= Ada_05 - and then Is_Tagged_Type (Prefix_Type) - and then not Is_Concurrent_Type (Prefix_Type) - then - if Nkind (Parent (N)) = N_Generic_Association - or else Nkind (Parent (N)) = N_Requeue_Statement - or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration - then - if Find_Primitive_Operation (N) then - return; - end if; - - elsif Try_Object_Operation (N) then - return; - end if; - - -- If the transformation fails, it will be necessary to redo the - -- analysis with all errors enabled, to indicate candidate - -- interpretations and reasons for each failure ??? - - end if; - - elsif Is_Private_Type (Prefix_Type) then - - -- Allow access only to discriminants of the type. If the type has - -- no full view, gigi uses the parent type for the components, so we - -- do the same here. - - if No (Full_View (Prefix_Type)) then - Type_To_Use := Root_Type (Base_Type (Prefix_Type)); - Comp := First_Entity (Type_To_Use); - end if; - - while Present (Comp) loop - if Chars (Comp) = Chars (Sel) then - if Ekind (Comp) = E_Discriminant then - Set_Entity_With_Style_Check (Sel, Comp); - Generate_Reference (Comp, Sel); - - Set_Etype (Sel, Etype (Comp)); - Set_Etype (N, Etype (Comp)); - - if Is_Generic_Type (Prefix_Type) - or else Is_Generic_Type (Root_Type (Prefix_Type)) - then - Set_Original_Discriminant (Sel, Comp); - end if; - - -- Before declaring an error, check whether this is tagged - -- private type and a call to a primitive operation. - - elsif Ada_Version >= Ada_05 - and then Is_Tagged_Type (Prefix_Type) - and then Try_Object_Operation (N) - then - return; - - else - Error_Msg_NE - ("invisible selector for }", - N, First_Subtype (Prefix_Type)); - Set_Entity (Sel, Any_Id); - Set_Etype (N, Any_Type); - end if; - - return; - end if; - - Next_Entity (Comp); - end loop; - - elsif Is_Concurrent_Type (Prefix_Type) then - - -- Find visible operation with given name. For a protected type, - -- the possible candidates are discriminants, entries or protected - -- procedures. For a task type, the set can only include entries or - -- discriminants if the task type is not an enclosing scope. If it - -- is an enclosing scope (e.g. in an inner task) then all entities - -- are visible, but the prefix must denote the enclosing scope, i.e. - -- can only be a direct name or an expanded name. - - Set_Etype (Sel, Any_Type); - In_Scope := In_Open_Scopes (Prefix_Type); - - while Present (Comp) loop - if Chars (Comp) = Chars (Sel) then - if Is_Overloadable (Comp) then - Add_One_Interp (Sel, Comp, Etype (Comp)); - - -- If the prefix is tagged, the correct interpretation may - -- lie in the primitive or class-wide operations of the - -- type. Perform a simple conformance check to determine - -- whether Try_Object_Operation should be invoked even if - -- a visible entity is found. - - if Is_Tagged_Type (Prefix_Type) - and then - Nkind_In (Parent (N), N_Procedure_Call_Statement, - N_Function_Call, - N_Indexed_Component) - and then Has_Mode_Conformant_Spec (Comp) - then - Has_Candidate := True; - end if; - - elsif Ekind (Comp) = E_Discriminant - or else Ekind (Comp) = E_Entry_Family - or else (In_Scope - and then Is_Entity_Name (Name)) - then - Set_Entity_With_Style_Check (Sel, Comp); - Generate_Reference (Comp, Sel); - - else - goto Next_Comp; - end if; - - Set_Etype (Sel, Etype (Comp)); - Set_Etype (N, Etype (Comp)); - - if Ekind (Comp) = E_Discriminant then - Set_Original_Discriminant (Sel, Comp); - end if; - - -- For access type case, introduce explicit deference for more - -- uniform treatment of entry calls. - - if Is_Access_Type (Etype (Name)) then - Insert_Explicit_Dereference (Name); - Error_Msg_NW - (Warn_On_Dereference, "?implicit dereference", N); - end if; - end if; - - <<Next_Comp>> - Next_Entity (Comp); - exit when not In_Scope - and then - Comp = First_Private_Entity (Base_Type (Prefix_Type)); - end loop; - - -- If there is no visible entity with the given name or none of the - -- visible entities are plausible interpretations, check whether - -- there is some other primitive operation with that name. - - if Ada_Version >= Ada_05 - and then Is_Tagged_Type (Prefix_Type) - then - if (Etype (N) = Any_Type - or else not Has_Candidate) - and then Try_Object_Operation (N) - then - return; - - -- If the context is not syntactically a procedure call, it - -- may be a call to a primitive function declared outside of - -- the synchronized type. - - -- If the context is a procedure call, there might still be - -- an overloading between an entry and a primitive procedure - -- declared outside of the synchronized type, called in prefix - -- notation. This is harder to disambiguate because in one case - -- the controlling formal is implicit ??? - - elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement - and then Nkind (Parent (N)) /= N_Indexed_Component - and then Try_Object_Operation (N) - then - return; - end if; - end if; - - Set_Is_Overloaded (N, Is_Overloaded (Sel)); - - else - -- Invalid prefix - - Error_Msg_NE ("invalid prefix in selected component&", N, Sel); - end if; - - -- If N still has no type, the component is not defined in the prefix - - if Etype (N) = Any_Type then - - -- If the prefix is a single concurrent object, use its name in the - -- error message, rather than that of its anonymous type. - - if Is_Concurrent_Type (Prefix_Type) - and then Is_Internal_Name (Chars (Prefix_Type)) - and then not Is_Derived_Type (Prefix_Type) - and then Is_Entity_Name (Name) - then - - Error_Msg_Node_2 := Entity (Name); - Error_Msg_NE ("no selector& for&", N, Sel); - - Check_Misspelled_Selector (Type_To_Use, Sel); - - elsif Is_Generic_Type (Prefix_Type) - and then Ekind (Prefix_Type) = E_Record_Type_With_Private - and then Prefix_Type /= Etype (Prefix_Type) - and then Is_Record_Type (Etype (Prefix_Type)) - then - -- If this is a derived formal type, the parent may have - -- different visibility at this point. Try for an inherited - -- component before reporting an error. - - Set_Etype (Prefix (N), Etype (Prefix_Type)); - Analyze_Selected_Component (N); - return; - - elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private - and then Is_Generic_Actual_Type (Prefix_Type) - and then Present (Full_View (Prefix_Type)) - then - -- Similarly, if this the actual for a formal derived type, the - -- component inherited from the generic parent may not be visible - -- in the actual, but the selected component is legal. - - declare - Comp : Entity_Id; - - begin - Comp := - First_Component (Generic_Parent_Type (Parent (Prefix_Type))); - while Present (Comp) loop - if Chars (Comp) = Chars (Sel) then - Set_Entity_With_Style_Check (Sel, Comp); - Set_Etype (Sel, Etype (Comp)); - Set_Etype (N, Etype (Comp)); - return; - end if; - - Next_Component (Comp); - end loop; - - pragma Assert (Etype (N) /= Any_Type); - end; - - else - if Ekind (Prefix_Type) = E_Record_Subtype then - - -- Check whether this is a component of the base type - -- which is absent from a statically constrained subtype. - -- This will raise constraint error at run-time, but is - -- not a compile-time error. When the selector is illegal - -- for base type as well fall through and generate a - -- compilation error anyway. - - Comp := First_Component (Base_Type (Prefix_Type)); - while Present (Comp) loop - if Chars (Comp) = Chars (Sel) - and then Is_Visible_Component (Comp) - then - Set_Entity_With_Style_Check (Sel, Comp); - Generate_Reference (Comp, Sel); - Set_Etype (Sel, Etype (Comp)); - Set_Etype (N, Etype (Comp)); - - -- Emit appropriate message. Gigi will replace the - -- node subsequently with the appropriate Raise. - - Apply_Compile_Time_Constraint_Error - (N, "component not present in }?", - CE_Discriminant_Check_Failed, - Ent => Prefix_Type, Rep => False); - Set_Raises_Constraint_Error (N); - return; - end if; - - Next_Component (Comp); - end loop; - - end if; - - Error_Msg_Node_2 := First_Subtype (Prefix_Type); - Error_Msg_NE ("no selector& for}", N, Sel); - - Check_Misspelled_Selector (Type_To_Use, Sel); - end if; - - Set_Entity (Sel, Any_Id); - Set_Etype (Sel, Any_Type); - end if; - end Analyze_Selected_Component; - - --------------------------- - -- Analyze_Short_Circuit -- - --------------------------- - - procedure Analyze_Short_Circuit (N : Node_Id) is - L : constant Node_Id := Left_Opnd (N); - R : constant Node_Id := Right_Opnd (N); - Ind : Interp_Index; - It : Interp; - - begin - Analyze_Expression (L); - Analyze_Expression (R); - Set_Etype (N, Any_Type); - - if not Is_Overloaded (L) then - if Root_Type (Etype (L)) = Standard_Boolean - and then Has_Compatible_Type (R, Etype (L)) - then - Add_One_Interp (N, Etype (L), Etype (L)); - end if; - - else - Get_First_Interp (L, Ind, It); - while Present (It.Typ) loop - if Root_Type (It.Typ) = Standard_Boolean - and then Has_Compatible_Type (R, It.Typ) - then - Add_One_Interp (N, It.Typ, It.Typ); - end if; - - Get_Next_Interp (Ind, It); - end loop; - end if; - - -- Here we have failed to find an interpretation. Clearly we know that - -- it is not the case that both operands can have an interpretation of - -- Boolean, but this is by far the most likely intended interpretation. - -- So we simply resolve both operands as Booleans, and at least one of - -- these resolutions will generate an error message, and we do not need - -- to give another error message on the short circuit operation itself. - - if Etype (N) = Any_Type then - Resolve (L, Standard_Boolean); - Resolve (R, Standard_Boolean); - Set_Etype (N, Standard_Boolean); - end if; - end Analyze_Short_Circuit; - - ------------------- - -- Analyze_Slice -- - ------------------- - - procedure Analyze_Slice (N : Node_Id) is - P : constant Node_Id := Prefix (N); - D : constant Node_Id := Discrete_Range (N); - Array_Type : Entity_Id; - - procedure Analyze_Overloaded_Slice; - -- If the prefix is overloaded, select those interpretations that - -- yield a one-dimensional array type. - - ------------------------------ - -- Analyze_Overloaded_Slice -- - ------------------------------ - - procedure Analyze_Overloaded_Slice is - I : Interp_Index; - It : Interp; - Typ : Entity_Id; - - begin - Set_Etype (N, Any_Type); - - Get_First_Interp (P, I, It); - while Present (It.Nam) loop - Typ := It.Typ; - - if Is_Access_Type (Typ) then - Typ := Designated_Type (Typ); - Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); - end if; - - if Is_Array_Type (Typ) - and then Number_Dimensions (Typ) = 1 - and then Has_Compatible_Type (D, Etype (First_Index (Typ))) - then - Add_One_Interp (N, Typ, Typ); - end if; - - Get_Next_Interp (I, It); - end loop; - - if Etype (N) = Any_Type then - Error_Msg_N ("expect array type in prefix of slice", N); - end if; - end Analyze_Overloaded_Slice; - - -- Start of processing for Analyze_Slice - - begin - Analyze (P); - Analyze (D); - - if Is_Overloaded (P) then - Analyze_Overloaded_Slice; - - else - Array_Type := Etype (P); - Set_Etype (N, Any_Type); - - if Is_Access_Type (Array_Type) then - Array_Type := Designated_Type (Array_Type); - Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); - end if; - - if not Is_Array_Type (Array_Type) then - Wrong_Type (P, Any_Array); - - elsif Number_Dimensions (Array_Type) > 1 then - Error_Msg_N - ("type is not one-dimensional array in slice prefix", N); - - elsif not - Has_Compatible_Type (D, Etype (First_Index (Array_Type))) - then - Wrong_Type (D, Etype (First_Index (Array_Type))); - - else - Set_Etype (N, Array_Type); - end if; - end if; - end Analyze_Slice; - - ----------------------------- - -- Analyze_Type_Conversion -- - ----------------------------- - - procedure Analyze_Type_Conversion (N : Node_Id) is - Expr : constant Node_Id := Expression (N); - T : Entity_Id; - - begin - -- If Conversion_OK is set, then the Etype is already set, and the - -- only processing required is to analyze the expression. This is - -- used to construct certain "illegal" conversions which are not - -- allowed by Ada semantics, but can be handled OK by Gigi, see - -- Sinfo for further details. - - if Conversion_OK (N) then - Analyze (Expr); - return; - end if; - - -- Otherwise full type analysis is required, as well as some semantic - -- checks to make sure the argument of the conversion is appropriate. - - Find_Type (Subtype_Mark (N)); - T := Entity (Subtype_Mark (N)); - Set_Etype (N, T); - Check_Fully_Declared (T, N); - Analyze_Expression (Expr); - Validate_Remote_Type_Type_Conversion (N); - - -- Only remaining step is validity checks on the argument. These - -- are skipped if the conversion does not come from the source. - - if not Comes_From_Source (N) then - return; - - -- If there was an error in a generic unit, no need to replicate the - -- error message. Conversely, constant-folding in the generic may - -- transform the argument of a conversion into a string literal, which - -- is legal. Therefore the following tests are not performed in an - -- instance. - - elsif In_Instance then - return; - - elsif Nkind (Expr) = N_Null then - Error_Msg_N ("argument of conversion cannot be null", N); - Error_Msg_N ("\use qualified expression instead", N); - Set_Etype (N, Any_Type); - - elsif Nkind (Expr) = N_Aggregate then - Error_Msg_N ("argument of conversion cannot be aggregate", N); - Error_Msg_N ("\use qualified expression instead", N); - - elsif Nkind (Expr) = N_Allocator then - Error_Msg_N ("argument of conversion cannot be an allocator", N); - Error_Msg_N ("\use qualified expression instead", N); - - elsif Nkind (Expr) = N_String_Literal then - Error_Msg_N ("argument of conversion cannot be string literal", N); - Error_Msg_N ("\use qualified expression instead", N); - - elsif Nkind (Expr) = N_Character_Literal then - if Ada_Version = Ada_83 then - Resolve (Expr, T); - else - Error_Msg_N ("argument of conversion cannot be character literal", - N); - Error_Msg_N ("\use qualified expression instead", N); - end if; - - elsif Nkind (Expr) = N_Attribute_Reference - and then - (Attribute_Name (Expr) = Name_Access or else - Attribute_Name (Expr) = Name_Unchecked_Access or else - Attribute_Name (Expr) = Name_Unrestricted_Access) - then - Error_Msg_N ("argument of conversion cannot be access", N); - Error_Msg_N ("\use qualified expression instead", N); - end if; - end Analyze_Type_Conversion; - - ---------------------- - -- Analyze_Unary_Op -- - ---------------------- - - procedure Analyze_Unary_Op (N : Node_Id) is - R : constant Node_Id := Right_Opnd (N); - Op_Id : Entity_Id := Entity (N); - - begin - Set_Etype (N, Any_Type); - Candidate_Type := Empty; - - Analyze_Expression (R); - - if Present (Op_Id) then - if Ekind (Op_Id) = E_Operator then - Find_Unary_Types (R, Op_Id, N); - else - Add_One_Interp (N, Op_Id, Etype (Op_Id)); - end if; - - else - Op_Id := Get_Name_Entity_Id (Chars (N)); - while Present (Op_Id) loop - if Ekind (Op_Id) = E_Operator then - if No (Next_Entity (First_Entity (Op_Id))) then - Find_Unary_Types (R, Op_Id, N); - end if; - - elsif Is_Overloadable (Op_Id) then - Analyze_User_Defined_Unary_Op (N, Op_Id); - end if; - - Op_Id := Homonym (Op_Id); - end loop; - end if; - - Operator_Check (N); - end Analyze_Unary_Op; - - ---------------------------------- - -- Analyze_Unchecked_Expression -- - ---------------------------------- - - procedure Analyze_Unchecked_Expression (N : Node_Id) is - begin - Analyze (Expression (N), Suppress => All_Checks); - Set_Etype (N, Etype (Expression (N))); - Save_Interps (Expression (N), N); - end Analyze_Unchecked_Expression; - - --------------------------------------- - -- Analyze_Unchecked_Type_Conversion -- - --------------------------------------- - - procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is - begin - Find_Type (Subtype_Mark (N)); - Analyze_Expression (Expression (N)); - Set_Etype (N, Entity (Subtype_Mark (N))); - end Analyze_Unchecked_Type_Conversion; - - ------------------------------------ - -- Analyze_User_Defined_Binary_Op -- - ------------------------------------ - - procedure Analyze_User_Defined_Binary_Op - (N : Node_Id; - Op_Id : Entity_Id) - is - begin - -- Only do analysis if the operator Comes_From_Source, since otherwise - -- the operator was generated by the expander, and all such operators - -- always refer to the operators in package Standard. - - if Comes_From_Source (N) then - declare - F1 : constant Entity_Id := First_Formal (Op_Id); - F2 : constant Entity_Id := Next_Formal (F1); - - begin - -- Verify that Op_Id is a visible binary function. Note that since - -- we know Op_Id is overloaded, potentially use visible means use - -- visible for sure (RM 9.4(11)). - - if Ekind (Op_Id) = E_Function - and then Present (F2) - and then (Is_Immediately_Visible (Op_Id) - or else Is_Potentially_Use_Visible (Op_Id)) - and then Has_Compatible_Type (Left_Opnd (N), Etype (F1)) - and then Has_Compatible_Type (Right_Opnd (N), Etype (F2)) - then - Add_One_Interp (N, Op_Id, Etype (Op_Id)); - - if Debug_Flag_E then - Write_Str ("user defined operator "); - Write_Name (Chars (Op_Id)); - Write_Str (" on node "); - Write_Int (Int (N)); - Write_Eol; - end if; - end if; - end; - end if; - end Analyze_User_Defined_Binary_Op; - - ----------------------------------- - -- Analyze_User_Defined_Unary_Op -- - ----------------------------------- - - procedure Analyze_User_Defined_Unary_Op - (N : Node_Id; - Op_Id : Entity_Id) - is - begin - -- Only do analysis if the operator Comes_From_Source, since otherwise - -- the operator was generated by the expander, and all such operators - -- always refer to the operators in package Standard. - - if Comes_From_Source (N) then - declare - F : constant Entity_Id := First_Formal (Op_Id); - - begin - -- Verify that Op_Id is a visible unary function. Note that since - -- we know Op_Id is overloaded, potentially use visible means use - -- visible for sure (RM 9.4(11)). - - if Ekind (Op_Id) = E_Function - and then No (Next_Formal (F)) - and then (Is_Immediately_Visible (Op_Id) - or else Is_Potentially_Use_Visible (Op_Id)) - and then Has_Compatible_Type (Right_Opnd (N), Etype (F)) - then - Add_One_Interp (N, Op_Id, Etype (Op_Id)); - end if; - end; - end if; - end Analyze_User_Defined_Unary_Op; - - --------------------------- - -- Check_Arithmetic_Pair -- - --------------------------- - - procedure Check_Arithmetic_Pair - (T1, T2 : Entity_Id; - Op_Id : Entity_Id; - N : Node_Id) - is - Op_Name : constant Name_Id := Chars (Op_Id); - - function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean; - -- Check whether the fixed-point type Typ has a user-defined operator - -- (multiplication or division) that should hide the corresponding - -- predefined operator. Used to implement Ada 2005 AI-264, to make - -- such operators more visible and therefore useful. - - -- If the name of the operation is an expanded name with prefix - -- Standard, the predefined universal fixed operator is available, - -- as specified by AI-420 (RM 4.5.5 (19.1/2)). - - function Specific_Type (T1, T2 : Entity_Id) return Entity_Id; - -- Get specific type (i.e. non-universal type if there is one) - - ------------------ - -- Has_Fixed_Op -- - ------------------ - - function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is - Bas : constant Entity_Id := Base_Type (Typ); - Ent : Entity_Id; - F1 : Entity_Id; - F2 : Entity_Id; - - begin - -- If the universal_fixed operation is given explicitly the rule - -- concerning primitive operations of the type do not apply. - - if Nkind (N) = N_Function_Call - and then Nkind (Name (N)) = N_Expanded_Name - and then Entity (Prefix (Name (N))) = Standard_Standard - then - return False; - end if; - - -- The operation is treated as primitive if it is declared in the - -- same scope as the type, and therefore on the same entity chain. - - Ent := Next_Entity (Typ); - while Present (Ent) loop - if Chars (Ent) = Chars (Op) then - F1 := First_Formal (Ent); - F2 := Next_Formal (F1); - - -- The operation counts as primitive if either operand or - -- result are of the given base type, and both operands are - -- fixed point types. - - if (Base_Type (Etype (F1)) = Bas - and then Is_Fixed_Point_Type (Etype (F2))) - - or else - (Base_Type (Etype (F2)) = Bas - and then Is_Fixed_Point_Type (Etype (F1))) - - or else - (Base_Type (Etype (Ent)) = Bas - and then Is_Fixed_Point_Type (Etype (F1)) - and then Is_Fixed_Point_Type (Etype (F2))) - then - return True; - end if; - end if; - - Next_Entity (Ent); - end loop; - - return False; - end Has_Fixed_Op; - - ------------------- - -- Specific_Type -- - ------------------- - - function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is - begin - if T1 = Universal_Integer or else T1 = Universal_Real then - return Base_Type (T2); - else - return Base_Type (T1); - end if; - end Specific_Type; - - -- Start of processing for Check_Arithmetic_Pair - - begin - if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then - - if Is_Numeric_Type (T1) - and then Is_Numeric_Type (T2) - and then (Covers (T1 => T1, T2 => T2) - or else - Covers (T1 => T2, T2 => T1)) - then - Add_One_Interp (N, Op_Id, Specific_Type (T1, T2)); - end if; - - elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then - - if Is_Fixed_Point_Type (T1) - and then (Is_Fixed_Point_Type (T2) - or else T2 = Universal_Real) - then - -- If Treat_Fixed_As_Integer is set then the Etype is already set - -- and no further processing is required (this is the case of an - -- operator constructed by Exp_Fixd for a fixed point operation) - -- Otherwise add one interpretation with universal fixed result - -- If the operator is given in functional notation, it comes - -- from source and Fixed_As_Integer cannot apply. - - if (Nkind (N) not in N_Op - or else not Treat_Fixed_As_Integer (N)) - and then - (not Has_Fixed_Op (T1, Op_Id) - or else Nkind (Parent (N)) = N_Type_Conversion) - then - Add_One_Interp (N, Op_Id, Universal_Fixed); - end if; - - elsif Is_Fixed_Point_Type (T2) - and then (Nkind (N) not in N_Op - or else not Treat_Fixed_As_Integer (N)) - and then T1 = Universal_Real - and then - (not Has_Fixed_Op (T1, Op_Id) - or else Nkind (Parent (N)) = N_Type_Conversion) - then - Add_One_Interp (N, Op_Id, Universal_Fixed); - - elsif Is_Numeric_Type (T1) - and then Is_Numeric_Type (T2) - and then (Covers (T1 => T1, T2 => T2) - or else - Covers (T1 => T2, T2 => T1)) - then - Add_One_Interp (N, Op_Id, Specific_Type (T1, T2)); - - elsif Is_Fixed_Point_Type (T1) - and then (Base_Type (T2) = Base_Type (Standard_Integer) - or else T2 = Universal_Integer) - then - Add_One_Interp (N, Op_Id, T1); - - elsif T2 = Universal_Real - and then Base_Type (T1) = Base_Type (Standard_Integer) - and then Op_Name = Name_Op_Multiply - then - Add_One_Interp (N, Op_Id, Any_Fixed); - - elsif T1 = Universal_Real - and then Base_Type (T2) = Base_Type (Standard_Integer) - then - Add_One_Interp (N, Op_Id, Any_Fixed); - - elsif Is_Fixed_Point_Type (T2) - and then (Base_Type (T1) = Base_Type (Standard_Integer) - or else T1 = Universal_Integer) - and then Op_Name = Name_Op_Multiply - then - Add_One_Interp (N, Op_Id, T2); - - elsif T1 = Universal_Real and then T2 = Universal_Integer then - Add_One_Interp (N, Op_Id, T1); - - elsif T2 = Universal_Real - and then T1 = Universal_Integer - and then Op_Name = Name_Op_Multiply - then - Add_One_Interp (N, Op_Id, T2); - end if; - - elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then - - -- Note: The fixed-point operands case with Treat_Fixed_As_Integer - -- set does not require any special processing, since the Etype is - -- already set (case of operation constructed by Exp_Fixed). - - if Is_Integer_Type (T1) - and then (Covers (T1 => T1, T2 => T2) - or else - Covers (T1 => T2, T2 => T1)) - then - Add_One_Interp (N, Op_Id, Specific_Type (T1, T2)); - end if; - - elsif Op_Name = Name_Op_Expon then - if Is_Numeric_Type (T1) - and then not Is_Fixed_Point_Type (T1) - and then (Base_Type (T2) = Base_Type (Standard_Integer) - or else T2 = Universal_Integer) - then - Add_One_Interp (N, Op_Id, Base_Type (T1)); - end if; - - else pragma Assert (Nkind (N) in N_Op_Shift); - - -- If not one of the predefined operators, the node may be one - -- of the intrinsic functions. Its kind is always specific, and - -- we can use it directly, rather than the name of the operation. - - if Is_Integer_Type (T1) - and then (Base_Type (T2) = Base_Type (Standard_Integer) - or else T2 = Universal_Integer) - then - Add_One_Interp (N, Op_Id, Base_Type (T1)); - end if; - end if; - end Check_Arithmetic_Pair; - - ------------------------------- - -- Check_Misspelled_Selector -- - ------------------------------- - - procedure Check_Misspelled_Selector - (Prefix : Entity_Id; - Sel : Node_Id) - is - Max_Suggestions : constant := 2; - Nr_Of_Suggestions : Natural := 0; - - Suggestion_1 : Entity_Id := Empty; - Suggestion_2 : Entity_Id := Empty; - - Comp : Entity_Id; - - begin - -- All the components of the prefix of selector Sel are matched - -- against Sel and a count is maintained of possible misspellings. - -- When at the end of the analysis there are one or two (not more!) - -- possible misspellings, these misspellings will be suggested as - -- possible correction. - - if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then - - -- Concurrent types should be handled as well ??? - - return; - end if; - - Comp := First_Entity (Prefix); - while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop - if Is_Visible_Component (Comp) then - if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then - Nr_Of_Suggestions := Nr_Of_Suggestions + 1; - - case Nr_Of_Suggestions is - when 1 => Suggestion_1 := Comp; - when 2 => Suggestion_2 := Comp; - when others => exit; - end case; - end if; - end if; - - Comp := Next_Entity (Comp); - end loop; - - -- Report at most two suggestions - - if Nr_Of_Suggestions = 1 then - Error_Msg_NE - ("\possible misspelling of&", Sel, Suggestion_1); - - elsif Nr_Of_Suggestions = 2 then - Error_Msg_Node_2 := Suggestion_2; - Error_Msg_NE - ("\possible misspelling of& or&", Sel, Suggestion_1); - end if; - end Check_Misspelled_Selector; - - ---------------------- - -- Defined_In_Scope -- - ---------------------- - - function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean - is - S1 : constant Entity_Id := Scope (Base_Type (T)); - begin - return S1 = S - or else (S1 = System_Aux_Id and then S = Scope (S1)); - end Defined_In_Scope; - - ------------------- - -- Diagnose_Call -- - ------------------- - - procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is - Actual : Node_Id; - X : Interp_Index; - It : Interp; - Err_Mode : Boolean; - New_Nam : Node_Id; - Void_Interp_Seen : Boolean := False; - - Success : Boolean; - pragma Warnings (Off, Boolean); - - begin - if Ada_Version >= Ada_05 then - Actual := First_Actual (N); - while Present (Actual) loop - - -- Ada 2005 (AI-50217): Post an error in case of premature - -- usage of an entity from the limited view. - - if not Analyzed (Etype (Actual)) - and then From_With_Type (Etype (Actual)) - then - Error_Msg_Qual_Level := 1; - Error_Msg_NE - ("missing with_clause for scope of imported type&", - Actual, Etype (Actual)); - Error_Msg_Qual_Level := 0; - end if; - - Next_Actual (Actual); - end loop; - end if; - - -- Analyze each candidate call again, with full error reporting - -- for each. - - Error_Msg_N - ("no candidate interpretations match the actuals:!", Nam); - Err_Mode := All_Errors_Mode; - All_Errors_Mode := True; - - -- If this is a call to an operation of a concurrent type, - -- the failed interpretations have been removed from the - -- name. Recover them to provide full diagnostics. - - if Nkind (Parent (Nam)) = N_Selected_Component then - Set_Entity (Nam, Empty); - New_Nam := New_Copy_Tree (Parent (Nam)); - Set_Is_Overloaded (New_Nam, False); - Set_Is_Overloaded (Selector_Name (New_Nam), False); - Set_Parent (New_Nam, Parent (Parent (Nam))); - Analyze_Selected_Component (New_Nam); - Get_First_Interp (Selector_Name (New_Nam), X, It); - else - Get_First_Interp (Nam, X, It); - end if; - - while Present (It.Nam) loop - if Etype (It.Nam) = Standard_Void_Type then - Void_Interp_Seen := True; - end if; - - Analyze_One_Call (N, It.Nam, True, Success); - Get_Next_Interp (X, It); - end loop; - - if Nkind (N) = N_Function_Call then - Get_First_Interp (Nam, X, It); - while Present (It.Nam) loop - if Ekind (It.Nam) = E_Function - or else Ekind (It.Nam) = E_Operator - then - return; - else - Get_Next_Interp (X, It); - end if; - end loop; - - -- If all interpretations are procedures, this deserves a - -- more precise message. Ditto if this appears as the prefix - -- of a selected component, which may be a lexical error. - - Error_Msg_N - ("\context requires function call, found procedure name", Nam); - - if Nkind (Parent (N)) = N_Selected_Component - and then N = Prefix (Parent (N)) - then - Error_Msg_N ( - "\period should probably be semicolon", Parent (N)); - end if; - - elsif Nkind (N) = N_Procedure_Call_Statement - and then not Void_Interp_Seen - then - Error_Msg_N ( - "\function name found in procedure call", Nam); - end if; - - All_Errors_Mode := Err_Mode; - end Diagnose_Call; - - --------------------------- - -- Find_Arithmetic_Types -- - --------------------------- - - procedure Find_Arithmetic_Types - (L, R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id) - is - Index1 : Interp_Index; - Index2 : Interp_Index; - It1 : Interp; - It2 : Interp; - - procedure Check_Right_Argument (T : Entity_Id); - -- Check right operand of operator - - -------------------------- - -- Check_Right_Argument -- - -------------------------- - - procedure Check_Right_Argument (T : Entity_Id) is - begin - if not Is_Overloaded (R) then - Check_Arithmetic_Pair (T, Etype (R), Op_Id, N); - else - Get_First_Interp (R, Index2, It2); - while Present (It2.Typ) loop - Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N); - Get_Next_Interp (Index2, It2); - end loop; - end if; - end Check_Right_Argument; - - -- Start processing for Find_Arithmetic_Types - - begin - if not Is_Overloaded (L) then - Check_Right_Argument (Etype (L)); - - else - Get_First_Interp (L, Index1, It1); - while Present (It1.Typ) loop - Check_Right_Argument (It1.Typ); - Get_Next_Interp (Index1, It1); - end loop; - end if; - - end Find_Arithmetic_Types; - - ------------------------ - -- Find_Boolean_Types -- - ------------------------ - - procedure Find_Boolean_Types - (L, R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id) - is - Index : Interp_Index; - It : Interp; - - procedure Check_Numeric_Argument (T : Entity_Id); - -- Special case for logical operations one of whose operands is an - -- integer literal. If both are literal the result is any modular type. - - ---------------------------- - -- Check_Numeric_Argument -- - ---------------------------- - - procedure Check_Numeric_Argument (T : Entity_Id) is - begin - if T = Universal_Integer then - Add_One_Interp (N, Op_Id, Any_Modular); - - elsif Is_Modular_Integer_Type (T) then - Add_One_Interp (N, Op_Id, T); - end if; - end Check_Numeric_Argument; - - -- Start of processing for Find_Boolean_Types - - begin - if not Is_Overloaded (L) then - if Etype (L) = Universal_Integer - or else Etype (L) = Any_Modular - then - if not Is_Overloaded (R) then - Check_Numeric_Argument (Etype (R)); - - else - Get_First_Interp (R, Index, It); - while Present (It.Typ) loop - Check_Numeric_Argument (It.Typ); - Get_Next_Interp (Index, It); - end loop; - end if; - - -- If operands are aggregates, we must assume that they may be - -- boolean arrays, and leave disambiguation for the second pass. - -- If only one is an aggregate, verify that the other one has an - -- interpretation as a boolean array - - elsif Nkind (L) = N_Aggregate then - if Nkind (R) = N_Aggregate then - Add_One_Interp (N, Op_Id, Etype (L)); - - elsif not Is_Overloaded (R) then - if Valid_Boolean_Arg (Etype (R)) then - Add_One_Interp (N, Op_Id, Etype (R)); - end if; - - else - Get_First_Interp (R, Index, It); - while Present (It.Typ) loop - if Valid_Boolean_Arg (It.Typ) then - Add_One_Interp (N, Op_Id, It.Typ); - end if; - - Get_Next_Interp (Index, It); - end loop; - end if; - - elsif Valid_Boolean_Arg (Etype (L)) - and then Has_Compatible_Type (R, Etype (L)) - then - Add_One_Interp (N, Op_Id, Etype (L)); - end if; - - else - Get_First_Interp (L, Index, It); - while Present (It.Typ) loop - if Valid_Boolean_Arg (It.Typ) - and then Has_Compatible_Type (R, It.Typ) - then - Add_One_Interp (N, Op_Id, It.Typ); - end if; - - Get_Next_Interp (Index, It); - end loop; - end if; - end Find_Boolean_Types; - - --------------------------- - -- Find_Comparison_Types -- - --------------------------- - - procedure Find_Comparison_Types - (L, R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id) - is - Index : Interp_Index; - It : Interp; - Found : Boolean := False; - I_F : Interp_Index; - T_F : Entity_Id; - Scop : Entity_Id := Empty; - - procedure Try_One_Interp (T1 : Entity_Id); - -- Routine to try one proposed interpretation. Note that the context - -- of the operator plays no role in resolving the arguments, so that - -- if there is more than one interpretation of the operands that is - -- compatible with comparison, the operation is ambiguous. - - -------------------- - -- Try_One_Interp -- - -------------------- - - procedure Try_One_Interp (T1 : Entity_Id) is - begin - - -- If the operator is an expanded name, then the type of the operand - -- must be defined in the corresponding scope. If the type is - -- universal, the context will impose the correct type. - - if Present (Scop) - and then not Defined_In_Scope (T1, Scop) - and then T1 /= Universal_Integer - and then T1 /= Universal_Real - and then T1 /= Any_String - and then T1 /= Any_Composite - then - return; - end if; - - if Valid_Comparison_Arg (T1) - and then Has_Compatible_Type (R, T1) - then - if Found - and then Base_Type (T1) /= Base_Type (T_F) - then - It := Disambiguate (L, I_F, Index, Any_Type); - - if It = No_Interp then - Ambiguous_Operands (N); - Set_Etype (L, Any_Type); - return; - - else - T_F := It.Typ; - end if; - - else - Found := True; - T_F := T1; - I_F := Index; - end if; - - Set_Etype (L, T_F); - Find_Non_Universal_Interpretations (N, R, Op_Id, T1); - - end if; - end Try_One_Interp; - - -- Start processing for Find_Comparison_Types - - begin - -- If left operand is aggregate, the right operand has to - -- provide a usable type for it. - - if Nkind (L) = N_Aggregate - and then Nkind (R) /= N_Aggregate - then - Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N); - return; - end if; - - if Nkind (N) = N_Function_Call - and then Nkind (Name (N)) = N_Expanded_Name - then - Scop := Entity (Prefix (Name (N))); - - -- The prefix may be a package renaming, and the subsequent test - -- requires the original package. - - if Ekind (Scop) = E_Package - and then Present (Renamed_Entity (Scop)) - then - Scop := Renamed_Entity (Scop); - Set_Entity (Prefix (Name (N)), Scop); - end if; - end if; - - if not Is_Overloaded (L) then - Try_One_Interp (Etype (L)); - - else - Get_First_Interp (L, Index, It); - while Present (It.Typ) loop - Try_One_Interp (It.Typ); - Get_Next_Interp (Index, It); - end loop; - end if; - end Find_Comparison_Types; - - ---------------------------------------- - -- Find_Non_Universal_Interpretations -- - ---------------------------------------- - - procedure Find_Non_Universal_Interpretations - (N : Node_Id; - R : Node_Id; - Op_Id : Entity_Id; - T1 : Entity_Id) - is - Index : Interp_Index; - It : Interp; - - begin - if T1 = Universal_Integer - or else T1 = Universal_Real - then - if not Is_Overloaded (R) then - Add_One_Interp - (N, Op_Id, Standard_Boolean, Base_Type (Etype (R))); - else - Get_First_Interp (R, Index, It); - while Present (It.Typ) loop - if Covers (It.Typ, T1) then - Add_One_Interp - (N, Op_Id, Standard_Boolean, Base_Type (It.Typ)); - end if; - - Get_Next_Interp (Index, It); - end loop; - end if; - else - Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1)); - end if; - end Find_Non_Universal_Interpretations; - - ------------------------------ - -- Find_Concatenation_Types -- - ------------------------------ - - procedure Find_Concatenation_Types - (L, R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id) - is - Op_Type : constant Entity_Id := Etype (Op_Id); - - begin - if Is_Array_Type (Op_Type) - and then not Is_Limited_Type (Op_Type) - - and then (Has_Compatible_Type (L, Op_Type) - or else - Has_Compatible_Type (L, Component_Type (Op_Type))) - - and then (Has_Compatible_Type (R, Op_Type) - or else - Has_Compatible_Type (R, Component_Type (Op_Type))) - then - Add_One_Interp (N, Op_Id, Op_Type); - end if; - end Find_Concatenation_Types; - - ------------------------- - -- Find_Equality_Types -- - ------------------------- - - procedure Find_Equality_Types - (L, R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id) - is - Index : Interp_Index; - It : Interp; - Found : Boolean := False; - I_F : Interp_Index; - T_F : Entity_Id; - Scop : Entity_Id := Empty; - - procedure Try_One_Interp (T1 : Entity_Id); - -- The context of the operator plays no role in resolving the - -- arguments, so that if there is more than one interpretation - -- of the operands that is compatible with equality, the construct - -- is ambiguous and an error can be emitted now, after trying to - -- disambiguate, i.e. applying preference rules. - - -------------------- - -- Try_One_Interp -- - -------------------- - - procedure Try_One_Interp (T1 : Entity_Id) is - begin - -- If the operator is an expanded name, then the type of the operand - -- must be defined in the corresponding scope. If the type is - -- universal, the context will impose the correct type. An anonymous - -- type for a 'Access reference is also universal in this sense, as - -- the actual type is obtained from context. - -- In Ada 2005, the equality operator for anonymous access types - -- is declared in Standard, and preference rules apply to it. - - if Present (Scop) then - if Defined_In_Scope (T1, Scop) - or else T1 = Universal_Integer - or else T1 = Universal_Real - or else T1 = Any_Access - or else T1 = Any_String - or else T1 = Any_Composite - or else (Ekind (T1) = E_Access_Subprogram_Type - and then not Comes_From_Source (T1)) - then - null; - - elsif Ekind (T1) = E_Anonymous_Access_Type - and then Scop = Standard_Standard - then - null; - - else - -- The scope does not contain an operator for the type - - return; - end if; - end if; - - -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95: - -- Do not allow anonymous access types in equality operators. - - if Ada_Version < Ada_05 - and then Ekind (T1) = E_Anonymous_Access_Type - then - return; - end if; - - if T1 /= Standard_Void_Type - and then not Is_Limited_Type (T1) - and then not Is_Limited_Composite (T1) - and then Has_Compatible_Type (R, T1) - then - if Found - and then Base_Type (T1) /= Base_Type (T_F) - then - It := Disambiguate (L, I_F, Index, Any_Type); - - if It = No_Interp then - Ambiguous_Operands (N); - Set_Etype (L, Any_Type); - return; - - else - T_F := It.Typ; - end if; - - else - Found := True; - T_F := T1; - I_F := Index; - end if; - - if not Analyzed (L) then - Set_Etype (L, T_F); - end if; - - Find_Non_Universal_Interpretations (N, R, Op_Id, T1); - - -- Case of operator was not visible, Etype still set to Any_Type - - if Etype (N) = Any_Type then - Found := False; - end if; - - elsif Scop = Standard_Standard - and then Ekind (T1) = E_Anonymous_Access_Type - then - Found := True; - end if; - end Try_One_Interp; - - -- Start of processing for Find_Equality_Types - - begin - -- If left operand is aggregate, the right operand has to - -- provide a usable type for it. - - if Nkind (L) = N_Aggregate - and then Nkind (R) /= N_Aggregate - then - Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N); - return; - end if; - - if Nkind (N) = N_Function_Call - and then Nkind (Name (N)) = N_Expanded_Name - then - Scop := Entity (Prefix (Name (N))); - - -- The prefix may be a package renaming, and the subsequent test - -- requires the original package. - - if Ekind (Scop) = E_Package - and then Present (Renamed_Entity (Scop)) - then - Scop := Renamed_Entity (Scop); - Set_Entity (Prefix (Name (N)), Scop); - end if; - end if; - - if not Is_Overloaded (L) then - Try_One_Interp (Etype (L)); - - else - Get_First_Interp (L, Index, It); - while Present (It.Typ) loop - Try_One_Interp (It.Typ); - Get_Next_Interp (Index, It); - end loop; - end if; - end Find_Equality_Types; - - ------------------------- - -- Find_Negation_Types -- - ------------------------- - - procedure Find_Negation_Types - (R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id) - is - Index : Interp_Index; - It : Interp; - - begin - if not Is_Overloaded (R) then - if Etype (R) = Universal_Integer then - Add_One_Interp (N, Op_Id, Any_Modular); - elsif Valid_Boolean_Arg (Etype (R)) then - Add_One_Interp (N, Op_Id, Etype (R)); - end if; - - else - Get_First_Interp (R, Index, It); - while Present (It.Typ) loop - if Valid_Boolean_Arg (It.Typ) then - Add_One_Interp (N, Op_Id, It.Typ); - end if; - - Get_Next_Interp (Index, It); - end loop; - end if; - end Find_Negation_Types; - - ------------------------------ - -- Find_Primitive_Operation -- - ------------------------------ - - function Find_Primitive_Operation (N : Node_Id) return Boolean is - Obj : constant Node_Id := Prefix (N); - Op : constant Node_Id := Selector_Name (N); - - Prim : Elmt_Id; - Prims : Elist_Id; - Typ : Entity_Id; - - begin - Set_Etype (Op, Any_Type); - - if Is_Access_Type (Etype (Obj)) then - Typ := Designated_Type (Etype (Obj)); - else - Typ := Etype (Obj); - end if; - - if Is_Class_Wide_Type (Typ) then - Typ := Root_Type (Typ); - end if; - - Prims := Primitive_Operations (Typ); - - Prim := First_Elmt (Prims); - while Present (Prim) loop - if Chars (Node (Prim)) = Chars (Op) then - Add_One_Interp (Op, Node (Prim), Etype (Node (Prim))); - Set_Etype (N, Etype (Node (Prim))); - end if; - - Next_Elmt (Prim); - end loop; - - -- Now look for class-wide operations of the type or any of its - -- ancestors by iterating over the homonyms of the selector. - - declare - Cls_Type : constant Entity_Id := Class_Wide_Type (Typ); - Hom : Entity_Id; - - begin - Hom := Current_Entity (Op); - while Present (Hom) loop - if (Ekind (Hom) = E_Procedure - or else - Ekind (Hom) = E_Function) - and then Scope (Hom) = Scope (Typ) - and then Present (First_Formal (Hom)) - and then - (Base_Type (Etype (First_Formal (Hom))) = Cls_Type - or else - (Is_Access_Type (Etype (First_Formal (Hom))) - and then - Ekind (Etype (First_Formal (Hom))) = - E_Anonymous_Access_Type - and then - Base_Type - (Designated_Type (Etype (First_Formal (Hom)))) = - Cls_Type)) - then - Add_One_Interp (Op, Hom, Etype (Hom)); - Set_Etype (N, Etype (Hom)); - end if; - - Hom := Homonym (Hom); - end loop; - end; - - return Etype (Op) /= Any_Type; - end Find_Primitive_Operation; - - ---------------------- - -- Find_Unary_Types -- - ---------------------- - - procedure Find_Unary_Types - (R : Node_Id; - Op_Id : Entity_Id; - N : Node_Id) - is - Index : Interp_Index; - It : Interp; - - begin - if not Is_Overloaded (R) then - if Is_Numeric_Type (Etype (R)) then - Add_One_Interp (N, Op_Id, Base_Type (Etype (R))); - end if; - - else - Get_First_Interp (R, Index, It); - while Present (It.Typ) loop - if Is_Numeric_Type (It.Typ) then - Add_One_Interp (N, Op_Id, Base_Type (It.Typ)); - end if; - - Get_Next_Interp (Index, It); - end loop; - end if; - end Find_Unary_Types; - - ------------------ - -- Junk_Operand -- - ------------------ - - function Junk_Operand (N : Node_Id) return Boolean is - Enode : Node_Id; - - begin - if Error_Posted (N) then - return False; - end if; - - -- Get entity to be tested - - if Is_Entity_Name (N) - and then Present (Entity (N)) - then - Enode := N; - - -- An odd case, a procedure name gets converted to a very peculiar - -- function call, and here is where we detect this happening. - - elsif Nkind (N) = N_Function_Call - and then Is_Entity_Name (Name (N)) - and then Present (Entity (Name (N))) - then - Enode := Name (N); - - -- Another odd case, there are at least some cases of selected - -- components where the selected component is not marked as having - -- an entity, even though the selector does have an entity - - elsif Nkind (N) = N_Selected_Component - and then Present (Entity (Selector_Name (N))) - then - Enode := Selector_Name (N); - - else - return False; - end if; - - -- Now test the entity we got to see if it is a bad case - - case Ekind (Entity (Enode)) is - - when E_Package => - Error_Msg_N - ("package name cannot be used as operand", Enode); - - when Generic_Unit_Kind => - Error_Msg_N - ("generic unit name cannot be used as operand", Enode); - - when Type_Kind => - Error_Msg_N - ("subtype name cannot be used as operand", Enode); - - when Entry_Kind => - Error_Msg_N - ("entry name cannot be used as operand", Enode); - - when E_Procedure => - Error_Msg_N - ("procedure name cannot be used as operand", Enode); - - when E_Exception => - Error_Msg_N - ("exception name cannot be used as operand", Enode); - - when E_Block | E_Label | E_Loop => - Error_Msg_N - ("label name cannot be used as operand", Enode); - - when others => - return False; - - end case; - - return True; - end Junk_Operand; - - -------------------- - -- Operator_Check -- - -------------------- - - procedure Operator_Check (N : Node_Id) is - begin - Remove_Abstract_Operations (N); - - -- Test for case of no interpretation found for operator - - if Etype (N) = Any_Type then - declare - L : Node_Id; - R : Node_Id; - Op_Id : Entity_Id := Empty; - - begin - R := Right_Opnd (N); - - if Nkind (N) in N_Binary_Op then - L := Left_Opnd (N); - else - L := Empty; - end if; - - -- If either operand has no type, then don't complain further, - -- since this simply means that we have a propagated error. - - if R = Error - or else Etype (R) = Any_Type - or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type) - then - return; - - -- We explicitly check for the case of concatenation of component - -- with component to avoid reporting spurious matching array types - -- that might happen to be lurking in distant packages (such as - -- run-time packages). This also prevents inconsistencies in the - -- messages for certain ACVC B tests, which can vary depending on - -- types declared in run-time interfaces. Another improvement when - -- aggregates are present is to look for a well-typed operand. - - elsif Present (Candidate_Type) - and then (Nkind (N) /= N_Op_Concat - or else Is_Array_Type (Etype (L)) - or else Is_Array_Type (Etype (R))) - then - - if Nkind (N) = N_Op_Concat then - if Etype (L) /= Any_Composite - and then Is_Array_Type (Etype (L)) - then - Candidate_Type := Etype (L); - - elsif Etype (R) /= Any_Composite - and then Is_Array_Type (Etype (R)) - then - Candidate_Type := Etype (R); - end if; - end if; - - Error_Msg_NE - ("operator for} is not directly visible!", - N, First_Subtype (Candidate_Type)); - Error_Msg_N ("use clause would make operation legal!", N); - return; - - -- If either operand is a junk operand (e.g. package name), then - -- post appropriate error messages, but do not complain further. - - -- Note that the use of OR in this test instead of OR ELSE is - -- quite deliberate, we may as well check both operands in the - -- binary operator case. - - elsif Junk_Operand (R) - or (Nkind (N) in N_Binary_Op and then Junk_Operand (L)) - then - return; - - -- If we have a logical operator, one of whose operands is - -- Boolean, then we know that the other operand cannot resolve to - -- Boolean (since we got no interpretations), but in that case we - -- pretty much know that the other operand should be Boolean, so - -- resolve it that way (generating an error) - - elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then - if Etype (L) = Standard_Boolean then - Resolve (R, Standard_Boolean); - return; - elsif Etype (R) = Standard_Boolean then - Resolve (L, Standard_Boolean); - return; - end if; - - -- For an arithmetic operator or comparison operator, if one - -- of the operands is numeric, then we know the other operand - -- is not the same numeric type. If it is a non-numeric type, - -- then probably it is intended to match the other operand. - - elsif Nkind_In (N, N_Op_Add, - N_Op_Divide, - N_Op_Ge, - N_Op_Gt, - N_Op_Le) - or else - Nkind_In (N, N_Op_Lt, - N_Op_Mod, - N_Op_Multiply, - N_Op_Rem, - N_Op_Subtract) - then - if Is_Numeric_Type (Etype (L)) - and then not Is_Numeric_Type (Etype (R)) - then - Resolve (R, Etype (L)); - return; - - elsif Is_Numeric_Type (Etype (R)) - and then not Is_Numeric_Type (Etype (L)) - then - Resolve (L, Etype (R)); - return; - end if; - - -- Comparisons on A'Access are common enough to deserve a - -- special message. - - elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) - and then Ekind (Etype (L)) = E_Access_Attribute_Type - and then Ekind (Etype (R)) = E_Access_Attribute_Type - then - Error_Msg_N - ("two access attributes cannot be compared directly", N); - Error_Msg_N - ("\use qualified expression for one of the operands", - N); - return; - - -- Another one for C programmers - - elsif Nkind (N) = N_Op_Concat - and then Valid_Boolean_Arg (Etype (L)) - and then Valid_Boolean_Arg (Etype (R)) - then - Error_Msg_N ("invalid operands for concatenation", N); - Error_Msg_N ("\maybe AND was meant", N); - return; - - -- A special case for comparison of access parameter with null - - elsif Nkind (N) = N_Op_Eq - and then Is_Entity_Name (L) - and then Nkind (Parent (Entity (L))) = N_Parameter_Specification - and then Nkind (Parameter_Type (Parent (Entity (L)))) = - N_Access_Definition - and then Nkind (R) = N_Null - then - Error_Msg_N ("access parameter is not allowed to be null", L); - Error_Msg_N ("\(call would raise Constraint_Error)", L); - return; - end if; - - -- If we fall through then just give general message. Note that in - -- the following messages, if the operand is overloaded we choose - -- an arbitrary type to complain about, but that is probably more - -- useful than not giving a type at all. - - if Nkind (N) in N_Unary_Op then - Error_Msg_Node_2 := Etype (R); - Error_Msg_N ("operator& not defined for}", N); - return; - - else - if Nkind (N) in N_Binary_Op then - if not Is_Overloaded (L) - and then not Is_Overloaded (R) - and then Base_Type (Etype (L)) = Base_Type (Etype (R)) - then - Error_Msg_Node_2 := First_Subtype (Etype (R)); - Error_Msg_N ("there is no applicable operator& for}", N); - - else - -- Another attempt to find a fix: one of the candidate - -- interpretations may not be use-visible. This has - -- already been checked for predefined operators, so - -- we examine only user-defined functions. - - Op_Id := Get_Name_Entity_Id (Chars (N)); - - while Present (Op_Id) loop - if Ekind (Op_Id) /= E_Operator - and then Is_Overloadable (Op_Id) - then - if not Is_Immediately_Visible (Op_Id) - and then not In_Use (Scope (Op_Id)) - and then not Is_Abstract_Subprogram (Op_Id) - and then not Is_Hidden (Op_Id) - and then Ekind (Scope (Op_Id)) = E_Package - and then - Has_Compatible_Type - (L, Etype (First_Formal (Op_Id))) - and then Present - (Next_Formal (First_Formal (Op_Id))) - and then - Has_Compatible_Type - (R, - Etype (Next_Formal (First_Formal (Op_Id)))) - then - Error_Msg_N - ("No legal interpretation for operator&", N); - Error_Msg_NE - ("\use clause on& would make operation legal", - N, Scope (Op_Id)); - exit; - end if; - end if; - - Op_Id := Homonym (Op_Id); - end loop; - - if No (Op_Id) then - Error_Msg_N ("invalid operand types for operator&", N); - - if Nkind (N) /= N_Op_Concat then - Error_Msg_NE ("\left operand has}!", N, Etype (L)); - Error_Msg_NE ("\right operand has}!", N, Etype (R)); - end if; - end if; - end if; - end if; - end if; - end; - end if; - end Operator_Check; - - ----------------------------------------- - -- Process_Implicit_Dereference_Prefix -- - ----------------------------------------- - - function Process_Implicit_Dereference_Prefix - (E : Entity_Id; - P : Entity_Id) return Entity_Id - is - Ref : Node_Id; - Typ : constant Entity_Id := Designated_Type (Etype (P)); - - begin - if Present (E) - and then (Operating_Mode = Check_Semantics or else not Expander_Active) - then - -- We create a dummy reference to E to ensure that the reference - -- is not considered as part of an assignment (an implicit - -- dereference can never assign to its prefix). The Comes_From_Source - -- attribute needs to be propagated for accurate warnings. - - Ref := New_Reference_To (E, Sloc (P)); - Set_Comes_From_Source (Ref, Comes_From_Source (P)); - Generate_Reference (E, Ref); - end if; - - -- An implicit dereference is a legal occurrence of an - -- incomplete type imported through a limited_with clause, - -- if the full view is visible. - - if From_With_Type (Typ) - and then not From_With_Type (Scope (Typ)) - and then - (Is_Immediately_Visible (Scope (Typ)) - or else - (Is_Child_Unit (Scope (Typ)) - and then Is_Visible_Child_Unit (Scope (Typ)))) - then - return Available_View (Typ); - else - return Typ; - end if; - - end Process_Implicit_Dereference_Prefix; - - -------------------------------- - -- Remove_Abstract_Operations -- - -------------------------------- - - procedure Remove_Abstract_Operations (N : Node_Id) is - Abstract_Op : Entity_Id := Empty; - Address_Kludge : Boolean := False; - I : Interp_Index; - It : Interp; - - -- AI-310: If overloaded, remove abstract non-dispatching operations. We - -- activate this if either extensions are enabled, or if the abstract - -- operation in question comes from a predefined file. This latter test - -- allows us to use abstract to make operations invisible to users. In - -- particular, if type Address is non-private and abstract subprograms - -- are used to hide its operators, they will be truly hidden. - - type Operand_Position is (First_Op, Second_Op); - Univ_Type : constant Entity_Id := Universal_Interpretation (N); - - procedure Remove_Address_Interpretations (Op : Operand_Position); - -- Ambiguities may arise when the operands are literal and the address - -- operations in s-auxdec are visible. In that case, remove the - -- interpretation of a literal as Address, to retain the semantics of - -- Address as a private type. - - ------------------------------------ - -- Remove_Address_Interpretations -- - ------------------------------------ - - procedure Remove_Address_Interpretations (Op : Operand_Position) is - Formal : Entity_Id; - - begin - if Is_Overloaded (N) then - Get_First_Interp (N, I, It); - while Present (It.Nam) loop - Formal := First_Entity (It.Nam); - - if Op = Second_Op then - Formal := Next_Entity (Formal); - end if; - - if Is_Descendent_Of_Address (Etype (Formal)) then - Address_Kludge := True; - Remove_Interp (I); - end if; - - Get_Next_Interp (I, It); - end loop; - end if; - end Remove_Address_Interpretations; - - -- Start of processing for Remove_Abstract_Operations - - begin - if Is_Overloaded (N) then - Get_First_Interp (N, I, It); - - while Present (It.Nam) loop - if Is_Overloadable (It.Nam) - and then Is_Abstract_Subprogram (It.Nam) - and then not Is_Dispatching_Operation (It.Nam) - then - Abstract_Op := It.Nam; - - if Is_Descendent_Of_Address (It.Typ) then - Address_Kludge := True; - Remove_Interp (I); - exit; - - -- In Ada 2005, this operation does not participate in Overload - -- resolution. If the operation is defined in a predefined - -- unit, it is one of the operations declared abstract in some - -- variants of System, and it must be removed as well. - - elsif Ada_Version >= Ada_05 - or else Is_Predefined_File_Name - (Unit_File_Name (Get_Source_Unit (It.Nam))) - then - Remove_Interp (I); - exit; - end if; - end if; - - Get_Next_Interp (I, It); - end loop; - - if No (Abstract_Op) then - - -- If some interpretation yields an integer type, it is still - -- possible that there are address interpretations. Remove them - -- if one operand is a literal, to avoid spurious ambiguities - -- on systems where Address is a visible integer type. - - if Is_Overloaded (N) - and then Nkind (N) in N_Op - and then Is_Integer_Type (Etype (N)) - then - if Nkind (N) in N_Binary_Op then - if Nkind (Right_Opnd (N)) = N_Integer_Literal then - Remove_Address_Interpretations (Second_Op); - - elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then - Remove_Address_Interpretations (First_Op); - end if; - end if; - end if; - - elsif Nkind (N) in N_Op then - - -- Remove interpretations that treat literals as addresses. This - -- is never appropriate, even when Address is defined as a visible - -- Integer type. The reason is that we would really prefer Address - -- to behave as a private type, even in this case, which is there - -- only to accommodate oddities of VMS address sizes. If Address - -- is a visible integer type, we get lots of overload ambiguities. - - if Nkind (N) in N_Binary_Op then - declare - U1 : constant Boolean := - Present (Universal_Interpretation (Right_Opnd (N))); - U2 : constant Boolean := - Present (Universal_Interpretation (Left_Opnd (N))); - - begin - if U1 then - Remove_Address_Interpretations (Second_Op); - end if; - - if U2 then - Remove_Address_Interpretations (First_Op); - end if; - - if not (U1 and U2) then - - -- Remove corresponding predefined operator, which is - -- always added to the overload set. - - Get_First_Interp (N, I, It); - while Present (It.Nam) loop - if Scope (It.Nam) = Standard_Standard - and then Base_Type (It.Typ) = - Base_Type (Etype (Abstract_Op)) - then - Remove_Interp (I); - end if; - - Get_Next_Interp (I, It); - end loop; - - elsif Is_Overloaded (N) - and then Present (Univ_Type) - then - -- If both operands have a universal interpretation, - -- it is still necessary to remove interpretations that - -- yield Address. Any remaining ambiguities will be - -- removed in Disambiguate. - - Get_First_Interp (N, I, It); - while Present (It.Nam) loop - if Is_Descendent_Of_Address (It.Typ) then - Remove_Interp (I); - - elsif not Is_Type (It.Nam) then - Set_Entity (N, It.Nam); - end if; - - Get_Next_Interp (I, It); - end loop; - end if; - end; - end if; - - elsif Nkind (N) = N_Function_Call - and then - (Nkind (Name (N)) = N_Operator_Symbol - or else - (Nkind (Name (N)) = N_Expanded_Name - and then - Nkind (Selector_Name (Name (N))) = N_Operator_Symbol)) - then - - declare - Arg1 : constant Node_Id := First (Parameter_Associations (N)); - U1 : constant Boolean := - Present (Universal_Interpretation (Arg1)); - U2 : constant Boolean := - Present (Next (Arg1)) and then - Present (Universal_Interpretation (Next (Arg1))); - - begin - if U1 then - Remove_Address_Interpretations (First_Op); - end if; - - if U2 then - Remove_Address_Interpretations (Second_Op); - end if; - - if not (U1 and U2) then - Get_First_Interp (N, I, It); - while Present (It.Nam) loop - if Scope (It.Nam) = Standard_Standard - and then It.Typ = Base_Type (Etype (Abstract_Op)) - then - Remove_Interp (I); - end if; - - Get_Next_Interp (I, It); - end loop; - end if; - end; - end if; - - -- If the removal has left no valid interpretations, emit an error - -- message now and label node as illegal. - - if Present (Abstract_Op) then - Get_First_Interp (N, I, It); - - if No (It.Nam) then - - -- Removal of abstract operation left no viable candidate - - Set_Etype (N, Any_Type); - Error_Msg_Sloc := Sloc (Abstract_Op); - Error_Msg_NE - ("cannot call abstract operation& declared#", N, Abstract_Op); - - -- In Ada 2005, an abstract operation may disable predefined - -- operators. Since the context is not yet known, we mark the - -- predefined operators as potentially hidden. Do not include - -- predefined operators when addresses are involved since this - -- case is handled separately. - - elsif Ada_Version >= Ada_05 - and then not Address_Kludge - then - while Present (It.Nam) loop - if Is_Numeric_Type (It.Typ) - and then Scope (It.Typ) = Standard_Standard - then - Set_Abstract_Op (I, Abstract_Op); - end if; - - Get_Next_Interp (I, It); - end loop; - end if; - end if; - end if; - end Remove_Abstract_Operations; - - ----------------------- - -- Try_Indirect_Call -- - ----------------------- - - function Try_Indirect_Call - (N : Node_Id; - Nam : Entity_Id; - Typ : Entity_Id) return Boolean - is - Actual : Node_Id; - Formal : Entity_Id; - - Call_OK : Boolean; - pragma Warnings (Off, Call_OK); - - begin - Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK); - - Actual := First_Actual (N); - Formal := First_Formal (Designated_Type (Typ)); - while Present (Actual) and then Present (Formal) loop - if not Has_Compatible_Type (Actual, Etype (Formal)) then - return False; - end if; - - Next (Actual); - Next_Formal (Formal); - end loop; - - if No (Actual) and then No (Formal) then - Add_One_Interp (N, Nam, Etype (Designated_Type (Typ))); - - -- Nam is a candidate interpretation for the name in the call, - -- if it is not an indirect call. - - if not Is_Type (Nam) - and then Is_Entity_Name (Name (N)) - then - Set_Entity (Name (N), Nam); - end if; - - return True; - else - return False; - end if; - end Try_Indirect_Call; - - ---------------------- - -- Try_Indexed_Call -- - ---------------------- - - function Try_Indexed_Call - (N : Node_Id; - Nam : Entity_Id; - Typ : Entity_Id; - Skip_First : Boolean) return Boolean - is - Loc : constant Source_Ptr := Sloc (N); - Actuals : constant List_Id := Parameter_Associations (N); - Actual : Node_Id; - Index : Entity_Id; - - begin - Actual := First (Actuals); - - -- If the call was originally written in prefix form, skip the first - -- actual, which is obviously not defaulted. - - if Skip_First then - Next (Actual); - end if; - - Index := First_Index (Typ); - while Present (Actual) and then Present (Index) loop - - -- If the parameter list has a named association, the expression - -- is definitely a call and not an indexed component. - - if Nkind (Actual) = N_Parameter_Association then - return False; - end if; - - if Is_Entity_Name (Actual) - and then Is_Type (Entity (Actual)) - and then No (Next (Actual)) - then - Rewrite (N, - Make_Slice (Loc, - Prefix => Make_Function_Call (Loc, - Name => Relocate_Node (Name (N))), - Discrete_Range => - New_Occurrence_Of (Entity (Actual), Sloc (Actual)))); - - Analyze (N); - return True; - - elsif not Has_Compatible_Type (Actual, Etype (Index)) then - return False; - end if; - - Next (Actual); - Next_Index (Index); - end loop; - - if No (Actual) and then No (Index) then - Add_One_Interp (N, Nam, Component_Type (Typ)); - - -- Nam is a candidate interpretation for the name in the call, - -- if it is not an indirect call. - - if not Is_Type (Nam) - and then Is_Entity_Name (Name (N)) - then - Set_Entity (Name (N), Nam); - end if; - - return True; - else - return False; - end if; - end Try_Indexed_Call; - - -------------------------- - -- Try_Object_Operation -- - -------------------------- - - function Try_Object_Operation (N : Node_Id) return Boolean is - K : constant Node_Kind := Nkind (Parent (N)); - Is_Subprg_Call : constant Boolean := Nkind_In - (K, N_Procedure_Call_Statement, - N_Function_Call); - Loc : constant Source_Ptr := Sloc (N); - Obj : constant Node_Id := Prefix (N); - Subprog : constant Node_Id := - Make_Identifier (Sloc (Selector_Name (N)), - Chars => Chars (Selector_Name (N))); - -- Identifier on which possible interpretations will be collected - - Report_Error : Boolean := False; - -- If no candidate interpretation matches the context, redo the - -- analysis with error enabled to provide additional information. - - Actual : Node_Id; - Candidate : Entity_Id := Empty; - New_Call_Node : Node_Id := Empty; - Node_To_Replace : Node_Id; - Obj_Type : Entity_Id := Etype (Obj); - Success : Boolean := False; - - function Valid_Candidate - (Success : Boolean; - Call : Node_Id; - Subp : Entity_Id) return Entity_Id; - -- If the subprogram is a valid interpretation, record it, and add - -- to the list of interpretations of Subprog. - - procedure Complete_Object_Operation - (Call_Node : Node_Id; - Node_To_Replace : Node_Id); - -- Make Subprog the name of Call_Node, replace Node_To_Replace with - -- Call_Node, insert the object (or its dereference) as the first actual - -- in the call, and complete the analysis of the call. - - procedure Report_Ambiguity (Op : Entity_Id); - -- If a prefixed procedure call is ambiguous, indicate whether the - -- call includes an implicit dereference or an implicit 'Access. - - procedure Transform_Object_Operation - (Call_Node : out Node_Id; - Node_To_Replace : out Node_Id); - -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..) - -- Call_Node is the resulting subprogram call, Node_To_Replace is - -- either N or the parent of N, and Subprog is a reference to the - -- subprogram we are trying to match. - - function Try_Class_Wide_Operation - (Call_Node : Node_Id; - Node_To_Replace : Node_Id) return Boolean; - -- Traverse all ancestor types looking for a class-wide subprogram - -- for which the current operation is a valid non-dispatching call. - - procedure Try_One_Prefix_Interpretation (T : Entity_Id); - -- If prefix is overloaded, its interpretation may include different - -- tagged types, and we must examine the primitive operations and - -- the class-wide operations of each in order to find candidate - -- interpretations for the call as a whole. - - function Try_Primitive_Operation - (Call_Node : Node_Id; - Node_To_Replace : Node_Id) return Boolean; - -- Traverse the list of primitive subprograms looking for a dispatching - -- operation for which the current node is a valid call . - - --------------------- - -- Valid_Candidate -- - --------------------- - - function Valid_Candidate - (Success : Boolean; - Call : Node_Id; - Subp : Entity_Id) return Entity_Id - is - Comp_Type : Entity_Id; - - begin - -- If the subprogram is a valid interpretation, record it in global - -- variable Subprog, to collect all possible overloadings. - - if Success then - if Subp /= Entity (Subprog) then - Add_One_Interp (Subprog, Subp, Etype (Subp)); - end if; - end if; - - -- If the call may be an indexed call, retrieve component type of - -- resulting expression, and add possible interpretation. - - Comp_Type := Empty; - - if Nkind (Call) = N_Function_Call - and then Nkind (Parent (N)) = N_Indexed_Component - and then Needs_One_Actual (Subp) - then - if Is_Array_Type (Etype (Subp)) then - Comp_Type := Component_Type (Etype (Subp)); - - elsif Is_Access_Type (Etype (Subp)) - and then Is_Array_Type (Designated_Type (Etype (Subp))) - then - Comp_Type := Component_Type (Designated_Type (Etype (Subp))); - end if; - end if; - - if Present (Comp_Type) - and then Etype (Subprog) /= Comp_Type - then - Add_One_Interp (Subprog, Subp, Comp_Type); - end if; - - if Etype (Call) /= Any_Type then - return Subp; - else - return Empty; - end if; - end Valid_Candidate; - - ------------------------------- - -- Complete_Object_Operation -- - ------------------------------- - - procedure Complete_Object_Operation - (Call_Node : Node_Id; - Node_To_Replace : Node_Id) - is - Control : constant Entity_Id := First_Formal (Entity (Subprog)); - Formal_Type : constant Entity_Id := Etype (Control); - First_Actual : Node_Id; - - begin - -- Place the name of the operation, with its interpretations, - -- on the rewritten call. - - Set_Name (Call_Node, Subprog); - - First_Actual := First (Parameter_Associations (Call_Node)); - - -- For cross-reference purposes, treat the new node as being in - -- the source if the original one is. - - Set_Comes_From_Source (Subprog, Comes_From_Source (N)); - Set_Comes_From_Source (Call_Node, Comes_From_Source (N)); - - if Nkind (N) = N_Selected_Component - and then not Inside_A_Generic - then - Set_Entity (Selector_Name (N), Entity (Subprog)); - end if; - - -- If need be, rewrite first actual as an explicit dereference - -- If the call is overloaded, the rewriting can only be done - -- once the primitive operation is identified. - - if Is_Overloaded (Subprog) then - - -- The prefix itself may be overloaded, and its interpretations - -- must be propagated to the new actual in the call. - - if Is_Overloaded (Obj) then - Save_Interps (Obj, First_Actual); - end if; - - Rewrite (First_Actual, Obj); - - elsif not Is_Access_Type (Formal_Type) - and then Is_Access_Type (Etype (Obj)) - then - Rewrite (First_Actual, - Make_Explicit_Dereference (Sloc (Obj), Obj)); - Analyze (First_Actual); - - -- If we need to introduce an explicit dereference, verify that - -- the resulting actual is compatible with the mode of the formal. - - if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter - and then Is_Access_Constant (Etype (Obj)) - then - Error_Msg_NE - ("expect variable in call to&", Prefix (N), Entity (Subprog)); - end if; - - -- Conversely, if the formal is an access parameter and the object - -- is not, replace the actual with a 'Access reference. Its analysis - -- will check that the object is aliased. - - elsif Is_Access_Type (Formal_Type) - and then not Is_Access_Type (Etype (Obj)) - then - -- A special case: A.all'access is illegal if A is an access to a - -- constant and the context requires an access to a variable. - - if not Is_Access_Constant (Formal_Type) then - if (Nkind (Obj) = N_Explicit_Dereference - and then Is_Access_Constant (Etype (Prefix (Obj)))) - or else not Is_Variable (Obj) - then - Error_Msg_NE - ("actual for& must be a variable", Obj, Control); - end if; - end if; - - Rewrite (First_Actual, - Make_Attribute_Reference (Loc, - Attribute_Name => Name_Access, - Prefix => Relocate_Node (Obj))); - - if not Is_Aliased_View (Obj) then - Error_Msg_NE - ("object in prefixed call to& must be aliased" - & " (RM-2005 4.3.1 (13))", - Prefix (First_Actual), Subprog); - end if; - - Analyze (First_Actual); - - else - if Is_Overloaded (Obj) then - Save_Interps (Obj, First_Actual); - end if; - - Rewrite (First_Actual, Obj); - end if; - - Rewrite (Node_To_Replace, Call_Node); - - -- Propagate the interpretations collected in subprog to the new - -- function call node, to be resolved from context. - - if Is_Overloaded (Subprog) then - Save_Interps (Subprog, Node_To_Replace); - else - Analyze (Node_To_Replace); - end if; - end Complete_Object_Operation; - - ---------------------- - -- Report_Ambiguity -- - ---------------------- - - procedure Report_Ambiguity (Op : Entity_Id) is - Access_Formal : constant Boolean := - Is_Access_Type (Etype (First_Formal (Op))); - Access_Actual : constant Boolean := - Is_Access_Type (Etype (Prefix (N))); - - begin - Error_Msg_Sloc := Sloc (Op); - - if Access_Formal and then not Access_Actual then - if Nkind (Parent (Op)) = N_Full_Type_Declaration then - Error_Msg_N - ("\possible interpretation" - & " (inherited, with implicit 'Access) #", N); - else - Error_Msg_N - ("\possible interpretation (with implicit 'Access) #", N); - end if; - - elsif not Access_Formal and then Access_Actual then - if Nkind (Parent (Op)) = N_Full_Type_Declaration then - Error_Msg_N - ("\possible interpretation" - & " ( inherited, with implicit dereference) #", N); - else - Error_Msg_N - ("\possible interpretation (with implicit dereference) #", N); - end if; - - else - if Nkind (Parent (Op)) = N_Full_Type_Declaration then - Error_Msg_N ("\possible interpretation (inherited)#", N); - else - Error_Msg_N ("\possible interpretation#", N); - end if; - end if; - end Report_Ambiguity; - - -------------------------------- - -- Transform_Object_Operation -- - -------------------------------- - - procedure Transform_Object_Operation - (Call_Node : out Node_Id; - Node_To_Replace : out Node_Id) - is - Dummy : constant Node_Id := New_Copy (Obj); - -- Placeholder used as a first parameter in the call, replaced - -- eventually by the proper object. - - Parent_Node : constant Node_Id := Parent (N); - - Actual : Node_Id; - Actuals : List_Id; - - begin - -- Common case covering 1) Call to a procedure and 2) Call to a - -- function that has some additional actuals. - - if Nkind_In (Parent_Node, N_Function_Call, - N_Procedure_Call_Statement) - - -- N is a selected component node containing the name of the - -- subprogram. If N is not the name of the parent node we must - -- not replace the parent node by the new construct. This case - -- occurs when N is a parameterless call to a subprogram that - -- is an actual parameter of a call to another subprogram. For - -- example: - -- Some_Subprogram (..., Obj.Operation, ...) - - and then Name (Parent_Node) = N - then - Node_To_Replace := Parent_Node; - - Actuals := Parameter_Associations (Parent_Node); - - if Present (Actuals) then - Prepend (Dummy, Actuals); - else - Actuals := New_List (Dummy); - end if; - - if Nkind (Parent_Node) = N_Procedure_Call_Statement then - Call_Node := - Make_Procedure_Call_Statement (Loc, - Name => New_Copy (Subprog), - Parameter_Associations => Actuals); - - else - Call_Node := - Make_Function_Call (Loc, - Name => New_Copy (Subprog), - Parameter_Associations => Actuals); - - end if; - - -- Before analysis, a function call appears as an indexed component - -- if there are no named associations. - - elsif Nkind (Parent_Node) = N_Indexed_Component - and then N = Prefix (Parent_Node) - then - Node_To_Replace := Parent_Node; - - Actuals := Expressions (Parent_Node); - - Actual := First (Actuals); - while Present (Actual) loop - Analyze (Actual); - Next (Actual); - end loop; - - Prepend (Dummy, Actuals); - - Call_Node := - Make_Function_Call (Loc, - Name => New_Copy (Subprog), - Parameter_Associations => Actuals); - - -- Parameterless call: Obj.F is rewritten as F (Obj) - - else - Node_To_Replace := N; - - Call_Node := - Make_Function_Call (Loc, - Name => New_Copy (Subprog), - Parameter_Associations => New_List (Dummy)); - end if; - end Transform_Object_Operation; - - ------------------------------ - -- Try_Class_Wide_Operation -- - ------------------------------ - - function Try_Class_Wide_Operation - (Call_Node : Node_Id; - Node_To_Replace : Node_Id) return Boolean - is - Anc_Type : Entity_Id; - Matching_Op : Entity_Id := Empty; - Error : Boolean; - - procedure Traverse_Homonyms - (Anc_Type : Entity_Id; - Error : out Boolean); - -- Traverse the homonym chain of the subprogram searching for those - -- homonyms whose first formal has the Anc_Type's class-wide type, - -- or an anonymous access type designating the class-wide type. If - -- an ambiguity is detected, then Error is set to True. - - procedure Traverse_Interfaces - (Anc_Type : Entity_Id; - Error : out Boolean); - -- Traverse the list of interfaces, if any, associated with Anc_Type - -- and search for acceptable class-wide homonyms associated with each - -- interface. If an ambiguity is detected, then Error is set to True. - - ----------------------- - -- Traverse_Homonyms -- - ----------------------- - - procedure Traverse_Homonyms - (Anc_Type : Entity_Id; - Error : out Boolean) - is - Cls_Type : Entity_Id; - Hom : Entity_Id; - Hom_Ref : Node_Id; - Success : Boolean; - - begin - Error := False; - - Cls_Type := Class_Wide_Type (Anc_Type); - - Hom := Current_Entity (Subprog); - - -- Find operation whose first parameter is of the class-wide - -- type, a subtype thereof, or an anonymous access to same. - - while Present (Hom) loop - if (Ekind (Hom) = E_Procedure - or else - Ekind (Hom) = E_Function) - and then Scope (Hom) = Scope (Anc_Type) - and then Present (First_Formal (Hom)) - and then - (Base_Type (Etype (First_Formal (Hom))) = Cls_Type - or else - (Is_Access_Type (Etype (First_Formal (Hom))) - and then - Ekind (Etype (First_Formal (Hom))) = - E_Anonymous_Access_Type - and then - Base_Type - (Designated_Type (Etype (First_Formal (Hom)))) = - Cls_Type)) - then - Set_Etype (Call_Node, Any_Type); - Set_Is_Overloaded (Call_Node, False); - Success := False; - - if No (Matching_Op) then - Hom_Ref := New_Reference_To (Hom, Sloc (Subprog)); - Set_Etype (Call_Node, Any_Type); - Set_Parent (Call_Node, Parent (Node_To_Replace)); - - Set_Name (Call_Node, Hom_Ref); - - Analyze_One_Call - (N => Call_Node, - Nam => Hom, - Report => Report_Error, - Success => Success, - Skip_First => True); - - Matching_Op := - Valid_Candidate (Success, Call_Node, Hom); - - else - Analyze_One_Call - (N => Call_Node, - Nam => Hom, - Report => Report_Error, - Success => Success, - Skip_First => True); - - if Present (Valid_Candidate (Success, Call_Node, Hom)) - and then Nkind (Call_Node) /= N_Function_Call - then - Error_Msg_NE ("ambiguous call to&", N, Hom); - Report_Ambiguity (Matching_Op); - Report_Ambiguity (Hom); - Error := True; - return; - end if; - end if; - end if; - - Hom := Homonym (Hom); - end loop; - end Traverse_Homonyms; - - ------------------------- - -- Traverse_Interfaces -- - ------------------------- - - procedure Traverse_Interfaces - (Anc_Type : Entity_Id; - Error : out Boolean) - is - Intface_List : constant List_Id := - Abstract_Interface_List (Anc_Type); - Intface : Node_Id; - - begin - Error := False; - - if Is_Non_Empty_List (Intface_List) then - Intface := First (Intface_List); - while Present (Intface) loop - - -- Look for acceptable class-wide homonyms associated with - -- the interface. - - Traverse_Homonyms (Etype (Intface), Error); - - if Error then - return; - end if; - - -- Continue the search by looking at each of the interface's - -- associated interface ancestors. - - Traverse_Interfaces (Etype (Intface), Error); - - if Error then - return; - end if; - - Next (Intface); - end loop; - end if; - end Traverse_Interfaces; - - -- Start of processing for Try_Class_Wide_Operation - - begin - -- Loop through ancestor types (including interfaces), traversing - -- the homonym chain of the subprogram, trying out those homonyms - -- whose first formal has the class-wide type of the ancestor, or - -- an anonymous access type designating the class-wide type. - - Anc_Type := Obj_Type; - loop - -- Look for a match among homonyms associated with the ancestor - - Traverse_Homonyms (Anc_Type, Error); - - if Error then - return True; - end if; - - -- Continue the search for matches among homonyms associated with - -- any interfaces implemented by the ancestor. - - Traverse_Interfaces (Anc_Type, Error); - - if Error then - return True; - end if; - - exit when Etype (Anc_Type) = Anc_Type; - Anc_Type := Etype (Anc_Type); - end loop; - - if Present (Matching_Op) then - Set_Etype (Call_Node, Etype (Matching_Op)); - end if; - - return Present (Matching_Op); - end Try_Class_Wide_Operation; - - ----------------------------------- - -- Try_One_Prefix_Interpretation -- - ----------------------------------- - - procedure Try_One_Prefix_Interpretation (T : Entity_Id) is - begin - Obj_Type := T; - - if Is_Access_Type (Obj_Type) then - Obj_Type := Designated_Type (Obj_Type); - end if; - - if Ekind (Obj_Type) = E_Private_Subtype then - Obj_Type := Base_Type (Obj_Type); - end if; - - if Is_Class_Wide_Type (Obj_Type) then - Obj_Type := Etype (Class_Wide_Type (Obj_Type)); - end if; - - -- The type may have be obtained through a limited_with clause, - -- in which case the primitive operations are available on its - -- non-limited view. If still incomplete, retrieve full view. - - if Ekind (Obj_Type) = E_Incomplete_Type - and then From_With_Type (Obj_Type) - then - Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type)); - end if; - - -- If the object is not tagged, or the type is still an incomplete - -- type, this is not a prefixed call. - - if not Is_Tagged_Type (Obj_Type) - or else Is_Incomplete_Type (Obj_Type) - then - return; - end if; - - if Try_Primitive_Operation - (Call_Node => New_Call_Node, - Node_To_Replace => Node_To_Replace) - or else - Try_Class_Wide_Operation - (Call_Node => New_Call_Node, - Node_To_Replace => Node_To_Replace) - then - null; - end if; - end Try_One_Prefix_Interpretation; - - ----------------------------- - -- Try_Primitive_Operation -- - ----------------------------- - - function Try_Primitive_Operation - (Call_Node : Node_Id; - Node_To_Replace : Node_Id) return Boolean - is - Elmt : Elmt_Id; - Prim_Op : Entity_Id; - Matching_Op : Entity_Id := Empty; - Prim_Op_Ref : Node_Id := Empty; - - Corr_Type : Entity_Id := Empty; - -- If the prefix is a synchronized type, the controlling type of - -- the primitive operation is the corresponding record type, else - -- this is the object type itself. - - Success : Boolean := False; - - function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id; - -- For tagged types the candidate interpretations are found in - -- the list of primitive operations of the type and its ancestors. - -- For formal tagged types we have to find the operations declared - -- in the same scope as the type (including in the generic formal - -- part) because the type itself carries no primitive operations, - -- except for formal derived types that inherit the operations of - -- the parent and progenitors. - -- If the context is a generic subprogram body, the generic formals - -- are visible by name, but are not in the entity list of the - -- subprogram because that list starts with the subprogram formals. - -- We retrieve the candidate operations from the generic declaration. - - function Valid_First_Argument_Of (Op : Entity_Id) return Boolean; - -- Verify that the prefix, dereferenced if need be, is a valid - -- controlling argument in a call to Op. The remaining actuals - -- are checked in the subsequent call to Analyze_One_Call. - - ------------------------------ - -- Collect_Generic_Type_Ops -- - ------------------------------ - - function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is - Bas : constant Entity_Id := Base_Type (T); - Candidates : constant Elist_Id := New_Elmt_List; - Subp : Entity_Id; - Formal : Entity_Id; - - procedure Check_Candidate; - -- The operation is a candidate if its first parameter is a - -- controlling operand of the desired type. - - ----------------------- - -- Check_Candidate; -- - ----------------------- - - procedure Check_Candidate is - begin - Formal := First_Formal (Subp); - - if Present (Formal) - and then Is_Controlling_Formal (Formal) - and then - (Base_Type (Etype (Formal)) = Bas - or else - (Is_Access_Type (Etype (Formal)) - and then Designated_Type (Etype (Formal)) = Bas)) - then - Append_Elmt (Subp, Candidates); - end if; - end Check_Candidate; - - -- Start of processing for Collect_Generic_Type_Ops - - begin - if Is_Derived_Type (T) then - return Primitive_Operations (T); - - elsif Ekind (Scope (T)) = E_Procedure - or else Ekind (Scope (T)) = E_Function - then - -- Scan the list of generic formals to find subprograms - -- that may have a first controlling formal of the type. - - declare - Decl : Node_Id; - - begin - Decl := - First (Generic_Formal_Declarations - (Unit_Declaration_Node (Scope (T)))); - while Present (Decl) loop - if Nkind (Decl) in N_Formal_Subprogram_Declaration then - Subp := Defining_Entity (Decl); - Check_Candidate; - end if; - - Next (Decl); - end loop; - end; - - return Candidates; - - else - -- Scan the list of entities declared in the same scope as - -- the type. In general this will be an open scope, given that - -- the call we are analyzing can only appear within a generic - -- declaration or body (either the one that declares T, or a - -- child unit). - - Subp := First_Entity (Scope (T)); - while Present (Subp) loop - if Is_Overloadable (Subp) then - Check_Candidate; - end if; - - Next_Entity (Subp); - end loop; - - return Candidates; - end if; - end Collect_Generic_Type_Ops; - - ----------------------------- - -- Valid_First_Argument_Of -- - ----------------------------- - - function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is - Typ : Entity_Id := Etype (First_Formal (Op)); - - begin - if Is_Concurrent_Type (Typ) - and then Present (Corresponding_Record_Type (Typ)) - then - Typ := Corresponding_Record_Type (Typ); - end if; - - -- Simple case. Object may be a subtype of the tagged type or - -- may be the corresponding record of a synchronized type. - - return Obj_Type = Typ - or else Base_Type (Obj_Type) = Typ - or else Corr_Type = Typ - - -- Prefix can be dereferenced - - or else - (Is_Access_Type (Corr_Type) - and then Designated_Type (Corr_Type) = Typ) - - -- Formal is an access parameter, for which the object - -- can provide an access. - - or else - (Ekind (Typ) = E_Anonymous_Access_Type - and then Designated_Type (Typ) = Base_Type (Corr_Type)); - end Valid_First_Argument_Of; - - -- Start of processing for Try_Primitive_Operation - - begin - -- Look for subprograms in the list of primitive operations. The name - -- must be identical, and the kind of call indicates the expected - -- kind of operation (function or procedure). If the type is a - -- (tagged) synchronized type, the primitive ops are attached to the - -- corresponding record (base) type. - - if Is_Concurrent_Type (Obj_Type) then - if not Present (Corresponding_Record_Type (Obj_Type)) then - return False; - end if; - - Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type)); - Elmt := First_Elmt (Primitive_Operations (Corr_Type)); - - elsif not Is_Generic_Type (Obj_Type) then - Corr_Type := Obj_Type; - Elmt := First_Elmt (Primitive_Operations (Obj_Type)); - - else - Corr_Type := Obj_Type; - Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type)); - end if; - - while Present (Elmt) loop - Prim_Op := Node (Elmt); - - if Chars (Prim_Op) = Chars (Subprog) - and then Present (First_Formal (Prim_Op)) - and then Valid_First_Argument_Of (Prim_Op) - and then - (Nkind (Call_Node) = N_Function_Call) - = (Ekind (Prim_Op) = E_Function) - then - -- Ada 2005 (AI-251): If this primitive operation corresponds - -- with an immediate ancestor interface there is no need to add - -- it to the list of interpretations; the corresponding aliased - -- primitive is also in this list of primitive operations and - -- will be used instead. - - if (Present (Interface_Alias (Prim_Op)) - and then Is_Ancestor (Find_Dispatching_Type - (Alias (Prim_Op)), Corr_Type)) - or else - - -- Do not consider hidden primitives unless the type is - -- in an open scope or we are within an instance, where - -- visibility is known to be correct. - - (Is_Hidden (Prim_Op) - and then not Is_Immediately_Visible (Obj_Type) - and then not In_Instance) - then - goto Continue; - end if; - - Set_Etype (Call_Node, Any_Type); - Set_Is_Overloaded (Call_Node, False); - - if No (Matching_Op) then - Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog)); - Candidate := Prim_Op; - - Set_Parent (Call_Node, Parent (Node_To_Replace)); - - Set_Name (Call_Node, Prim_Op_Ref); - Success := False; - - Analyze_One_Call - (N => Call_Node, - Nam => Prim_Op, - Report => Report_Error, - Success => Success, - Skip_First => True); - - Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op); - - -- More than one interpretation, collect for subsequent - -- disambiguation. If this is a procedure call and there - -- is another match, report ambiguity now. - - else - Analyze_One_Call - (N => Call_Node, - Nam => Prim_Op, - Report => Report_Error, - Success => Success, - Skip_First => True); - - if Present (Valid_Candidate (Success, Call_Node, Prim_Op)) - and then Nkind (Call_Node) /= N_Function_Call - then - Error_Msg_NE ("ambiguous call to&", N, Prim_Op); - Report_Ambiguity (Matching_Op); - Report_Ambiguity (Prim_Op); - return True; - end if; - end if; - end if; - - <<Continue>> - Next_Elmt (Elmt); - end loop; - - if Present (Matching_Op) then - Set_Etype (Call_Node, Etype (Matching_Op)); - end if; - - return Present (Matching_Op); - end Try_Primitive_Operation; - - -- Start of processing for Try_Object_Operation - - begin - Analyze_Expression (Obj); - - -- Analyze the actuals if node is known to be a subprogram call - - if Is_Subprg_Call and then N = Name (Parent (N)) then - Actual := First (Parameter_Associations (Parent (N))); - while Present (Actual) loop - Analyze_Expression (Actual); - Next (Actual); - end loop; - end if; - - -- Build a subprogram call node, using a copy of Obj as its first - -- actual. This is a placeholder, to be replaced by an explicit - -- dereference when needed. - - Transform_Object_Operation - (Call_Node => New_Call_Node, - Node_To_Replace => Node_To_Replace); - - Set_Etype (New_Call_Node, Any_Type); - Set_Etype (Subprog, Any_Type); - Set_Parent (New_Call_Node, Parent (Node_To_Replace)); - - if not Is_Overloaded (Obj) then - Try_One_Prefix_Interpretation (Obj_Type); - - else - declare - I : Interp_Index; - It : Interp; - begin - Get_First_Interp (Obj, I, It); - while Present (It.Nam) loop - Try_One_Prefix_Interpretation (It.Typ); - Get_Next_Interp (I, It); - end loop; - end; - end if; - - if Etype (New_Call_Node) /= Any_Type then - Complete_Object_Operation - (Call_Node => New_Call_Node, - Node_To_Replace => Node_To_Replace); - return True; - - elsif Present (Candidate) then - - -- The argument list is not type correct. Re-analyze with error - -- reporting enabled, and use one of the possible candidates. - -- In All_Errors_Mode, re-analyze all failed interpretations. - - if All_Errors_Mode then - Report_Error := True; - if Try_Primitive_Operation - (Call_Node => New_Call_Node, - Node_To_Replace => Node_To_Replace) - - or else - Try_Class_Wide_Operation - (Call_Node => New_Call_Node, - Node_To_Replace => Node_To_Replace) - then - null; - end if; - - else - Analyze_One_Call - (N => New_Call_Node, - Nam => Candidate, - Report => True, - Success => Success, - Skip_First => True); - end if; - - -- No need for further errors - - return True; - - else - -- There was no candidate operation, so report it as an error - -- in the caller: Analyze_Selected_Component. - - return False; - end if; - end Try_Object_Operation; - - --------- - -- wpo -- - --------- - - procedure wpo (T : Entity_Id) is - Op : Entity_Id; - E : Elmt_Id; - - begin - if not Is_Tagged_Type (T) then - return; - end if; - - E := First_Elmt (Primitive_Operations (Base_Type (T))); - while Present (E) loop - Op := Node (E); - Write_Int (Int (Op)); - Write_Str (" === "); - Write_Name (Chars (Op)); - Write_Str (" in "); - Write_Name (Chars (Scope (Op))); - Next_Elmt (E); - Write_Eol; - end loop; - end wpo; - -end Sem_Ch4; |