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Diffstat (limited to 'gcc-4.2.1/gcc/ada/sem_ch4.adb')
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diff --git a/gcc-4.2.1/gcc/ada/sem_ch4.adb b/gcc-4.2.1/gcc/ada/sem_ch4.adb new file mode 100644 index 000000000..ac5f38da2 --- /dev/null +++ b/gcc-4.2.1/gcc/ada/sem_ch4.adb @@ -0,0 +1,5371 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ C H 4 -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2006, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 2, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING. If not, write -- +-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- +-- Boston, MA 02110-1301, USA. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +with Atree; use Atree; +with 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 Nlists; use Nlists; +with Nmake; use Nmake; +with Opt; use Opt; +with Output; use Output; +with Restrict; use Restrict; +with Rident; use Rident; +with Rtsfind; use Rtsfind; +with Sem; use Sem; +with Sem_Cat; use Sem_Cat; +with Sem_Ch3; use Sem_Ch3; +with Sem_Ch8; use Sem_Ch8; +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; + +with GNAT.Spelling_Checker; use GNAT.Spelling_Checker; + +package body Sem_Ch4 is + + ----------------------- + -- Local Subprograms -- + ----------------------- + + 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. See 4327-001 for an example. + + 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 intepretations + -- 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. + + 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. + + procedure Process_Implicit_Dereference_Prefix + (E : Entity_Id; + P : Node_Id); + -- Called when P is the prefix of an implicit dereference, denoting an + -- object E. If in semantics only mode (-gnatc or generic), record that is + -- a reference to E. Normally, such a reference is generated only when the + -- implicit dereference is expanded into an explicit one. E may be empty, + -- in which case this procedure does nothing. + + 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) 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). + + 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): Give support to the object operation notation + + ------------------------ + -- 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) = N_In + or else Nkind (N) = N_Not_In + then + Error_Msg_N ("ambiguous operands for membership", N); + + elsif Nkind (N) = N_Op_Eq + or else Nkind (N) = 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 + Check_Restriction (No_Allocators, N); + + if Nkind (E) = N_Qualified_Expression then + Acc_Type := Create_Itype (E_Allocator_Type, N); + Set_Etype (Acc_Type, Acc_Type); + Init_Size_Align (Acc_Type); + Find_Type (Subtype_Mark (E)); + Type_Id := Entity (Subtype_Mark (E)); + Check_Fully_Declared (Type_Id, N); + Set_Directly_Designated_Type (Acc_Type, Type_Id); + + if Is_Limited_Type (Type_Id) + and then Comes_From_Source (N) + and then not In_Instance_Body + then + -- Ada 2005 (AI-287): Do not post an error if the expression + -- corresponds to a limited aggregate. Limited aggregates + -- are checked in sem_aggr in a per-component manner + -- (compare with handling of Get_Value subprogram). + + if Ada_Version >= Ada_05 + and then Nkind (Expression (E)) = N_Aggregate + then + null; + else + Error_Msg_N ("initialization not allowed for limited types", N); + Explain_Limited_Type (Type_Id, N); + end if; + end if; + + Analyze_And_Resolve (Expression (E), Type_Id); + + -- 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 no qualified expression is present + + 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); + Init_Size_Align (Acc_Type); + Set_Directly_Designated_Type (Acc_Type, Type_Id); + Check_Fully_Declared (Type_Id, N); + + -- Ada 2005 (AI-231) + + if Can_Never_Be_Null (Type_Id) then + Error_Msg_N ("(Ada 2005) qualified expression required", + Expression (N)); + 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 + Error_Msg_N + ("initialization required in unconstrained allocation", N); + end if; + end if; + end; + end if; + + if Is_Abstract (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 (N) = N_Op_Divide or else + Nkind (N) = N_Op_Mod or else + Nkind (N) = N_Op_Multiply or else + Nkind (N) = 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 := Name (N); + X : Interp_Index; + It : Interp; + Nam_Ent : Entity_Id; + Success : Boolean := False; + + 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. + + --------------------------- + -- 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; + + -- 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); + + 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. + + 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) + 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 + declare + 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 (K = N_Entry_Call_Alternative + or else K = 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; + + return; + end; + end if; + 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; + + -- 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) + and then Ekind (Designated_Type (Etype (Nam_Ent))) + = E_Subprogram_Type + then + Nam_Ent := Designated_Type (Etype (Nam_Ent)); + 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 + Set_Etype (Nam, It.Typ); + + elsif Nkind (Name (N)) = N_Selected_Component + or else Nkind (Name (N)) = 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 + -- is has the proper capitalization. + + 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 -- + --------------------------- + + -- 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 (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 + Set_Etype (N, Any_Type); + Candidate_Type := Empty; + + Analyze_Expression (L); + 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; + + ------------------------------------ + -- 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 => Relocate_Node (Left_Opnd (N)), + Right_Opnd => Relocate_Node (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 thru 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; + + Set_Etype (N, DT); + 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. + -- See e.g. 7117-014 and E317-001. + + 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 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 + 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); + + Actual := First (Parameter_Associations (N)); + while Present (Actual) loop + Analyze (Actual); + Check_Parameterless_Call (Actual); + Next_Actual (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 + Array_Type := Designated_Type (Array_Type); + Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); + 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 interpetation 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 (N) = N_Function_Call + or else Nkind (N) = 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 Ekind (U_N) in Type_Kind 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); + Formal : Entity_Id; + Actual : Node_Id; + Is_Indexed : Boolean := False; + Subp_Type : constant Entity_Id := Etype (Nam); + Norm_OK : Boolean; + + 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; + + -- 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. + + if Needs_No_Actuals (Nam) + and then Present (Actuals) + then + if Is_Array_Type (Subp_Type) then + Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type); + + 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)); + + -- The prefix can also be a parameterless function that returns an + -- access to subprogram. in which case this is an indirect call. + + elsif Is_Access_Type (Subp_Type) + and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type + then + Is_Indexed := Try_Indirect_Call (N, Nam, Subp_Type); + end if; + + end if; + + Normalize_Actuals (N, Nam, (Report and not Is_Indexed), Norm_OK); + + if not Norm_OK then + + -- Mismatch in number or names of parameters + + if 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 + + -- 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. Fixes b34014o. + + 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 Ekind (It.Nam) /= E_Operator + and then Hides_Op (It.Nam, Nam) + and then + Has_Compatible_Type + (First_Actual (N), Etype (First_Formal (It.Nam))) + and then (No (Next_Actual (First_Actual (N))) + or else Has_Compatible_Type + (Next_Actual (First_Actual (N)), + Etype (Next_Formal (First_Formal (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 Skip_First 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 + if Has_Compatible_Type (Actual, Etype (Formal)) 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 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)!", 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 + Comp := First_Entity (T); + 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)); + 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. + + if Is_Access_Type (Etype (Nam)) 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 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); + T : Entity_Id; + + begin + Set_Etype (N, Any_Type); + Find_Type (Mark); + T := Entity (Mark); + + if T = Any_Type then + return; + end if; + + Check_Fully_Declared (T, N); + Analyze_Expression (Expression (N)); + 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, T2) or else Covers (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); + Acc_Type : Entity_Id; + begin + Analyze (P); + Acc_Type := Create_Itype (E_Allocator_Type, N); + Set_Etype (Acc_Type, Acc_Type); + Init_Size_Align (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); + Comp : Entity_Id; + Entity_List : Entity_Id; + Prefix_Type : Entity_Id; + Pent : Entity_Id := Empty; + Act_Decl : Node_Id; + In_Scope : Boolean; + Parent_N : Node_Id; + + -- 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(15)). + + if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type) + and then Comes_From_Source (N) + then + Error_Msg_N + ("invalid dereference of a remote access to class-wide value", + N); + + -- 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; + + Process_Implicit_Dereference_Prefix (Pent, Name); + end if; + + Prefix_Type := Designated_Type (Prefix_Type); + end if; + + if Ekind (Prefix_Type) = E_Private_Subtype then + Prefix_Type := Base_Type (Prefix_Type); + end if; + + Entity_List := 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 + Entity_List := Root_Type (Prefix_Type); + end if; + + Comp := First_Entity (Entity_List); + + -- 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); + Generate_Reference (Comp, Sel); + + 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 type. + -- Example: + + -- limited with Pkg; + -- package Pkg is + -- type Acc_Inc is access Pkg.T; + -- X : Acc_Inc; + -- N : Natural := X.all.Comp; -- ERROR + -- end Pkg; + + if Nkind (Name) = N_Explicit_Dereference + and then From_With_Type (Etype (Prefix (Name))) + and then not Is_Potentially_Use_Visible (Etype (Name)) + 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; + + Next_Entity (Comp); + end loop; + + -- Ada 2005 (AI-252) + + if Ada_Version >= Ada_05 + and then Is_Tagged_Type (Prefix_Type) + and then Try_Object_Operation (N) + then + return; + + -- 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 + Entity_List := Root_Type (Base_Type (Prefix_Type)); + Comp := First_Entity (Entity_List); + 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; + + 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 + + -- Prefix is concurrent type. Find visible operation with given name + -- For a task, this 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)); + + 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; + + 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 (Entity_List, 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 (Entity_List, 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 + -- a further 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; + + 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. + + 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 + Ent : Entity_Id; + F1 : Entity_Id; + F2 : Entity_Id; + + begin + -- 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 type, and both operands are fixed + -- point types. + + if (Etype (F1) = Typ + and then Is_Fixed_Point_Type (Etype (F2))) + + or else + (Etype (F2) = Typ + and then Is_Fixed_Point_Type (Etype (F1))) + + or else + (Etype (Ent) = Typ + 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, T2) or else Covers (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 (Ada_Version >= Ada_05 and then 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 (Ada_Version >= Ada_05 and then 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, T2) or else Covers (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, T2) or else Covers (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; + + Get_Name_String (Chars (Sel)); + + declare + S : constant String (1 .. Name_Len) := Name_Buffer (1 .. Name_Len); + + begin + Comp := First_Entity (Prefix); + while Nr_Of_Suggestions <= Max_Suggestions + and then Present (Comp) + loop + if Is_Visible_Component (Comp) then + Get_Name_String (Chars (Comp)); + + if Is_Bad_Spelling_Of (Name_Buffer (1 .. Name_Len), S) 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; + 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; + Success : Boolean; + Err_Mode : Boolean; + New_Nam : Node_Id; + Void_Interp_Seen : Boolean := False; + + 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 (R, L, Op_Id, 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 (R, L, Op_Id, 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_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; + + 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 (N) = N_Op_And + or else + Nkind (N) = N_Op_Or + or else + Nkind (N) = 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 (N) = N_Op_Add or else + Nkind (N) = N_Op_Divide or else + Nkind (N) = N_Op_Ge or else + Nkind (N) = N_Op_Gt or else + Nkind (N) = N_Op_Le or else + Nkind (N) = N_Op_Lt or else + Nkind (N) = N_Op_Mod or else + Nkind (N) = N_Op_Multiply or else + Nkind (N) = N_Op_Rem or else + Nkind (N) = 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 (N) = N_Op_Eq or else + Nkind (N) = 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 + ("\they must be converted to an explicit type for comparison", + 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 + 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; + end if; + end Operator_Check; + + ----------------------------------------- + -- Process_Implicit_Dereference_Prefix -- + ----------------------------------------- + + procedure Process_Implicit_Dereference_Prefix + (E : Entity_Id; + P : Entity_Id) + is + Ref : Node_Id; + + 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; + end Process_Implicit_Dereference_Prefix; + + -------------------------------- + -- Remove_Abstract_Operations -- + -------------------------------- + + procedure Remove_Abstract_Operations (N : Node_Id) is + I : Interp_Index; + It : Interp; + Abstract_Op : Entity_Id := Empty; + + -- 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 + 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 not Is_Type (It.Nam) + and then Is_Abstract (It.Nam) + and then not Is_Dispatching_Operation (It.Nam) + then + Abstract_Op := It.Nam; + + -- In Ada 2005, this operation does not participate in Overload + -- resolution. If the operation is defined in in a predefined + -- unit, it is one of the operations declared abstract in some + -- variants of System, and it must be removed as well. + + if Ada_Version >= Ada_05 + or else Is_Predefined_File_Name + (Unit_File_Name (Get_Source_Unit (It.Nam))) + or else Is_Descendent_Of_Address (It.Typ) + 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 accomodate 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 + -- 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); + 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; + + 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) return Boolean + is + Actuals : constant List_Id := Parameter_Associations (N); + Actual : Node_Id; + Index : Entity_Id; + + begin + Actual := First (Actuals); + 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 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)); + Loc : constant Source_Ptr := Sloc (N); + Is_Subprg_Call : constant Boolean := K = N_Procedure_Call_Statement + or else K = N_Function_Call; + Obj : constant Node_Id := Prefix (N); + Subprog : constant Node_Id := Selector_Name (N); + + Actual : Node_Id; + New_Call_Node : Node_Id := Empty; + Node_To_Replace : Node_Id; + Obj_Type : Entity_Id := Etype (Obj); + + procedure Complete_Object_Operation + (Call_Node : Node_Id; + Node_To_Replace : Node_Id; + Subprog : 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 Transform_Object_Operation + (Call_Node : out Node_Id; + Node_To_Replace : out Node_Id; + Subprog : 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. + + 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 . + + ------------------------------- + -- Complete_Object_Operation -- + ------------------------------- + + procedure Complete_Object_Operation + (Call_Node : Node_Id; + Node_To_Replace : Node_Id; + Subprog : Node_Id) + is + Formal_Type : constant Entity_Id := + Etype (First_Formal (Entity (Subprog))); + First_Actual : Node_Id; + + begin + First_Actual := First (Parameter_Associations (Call_Node)); + Set_Name (Call_Node, Subprog); + + 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 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); + + -- 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 + Rewrite (First_Actual, + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Access, + Prefix => Relocate_Node (Obj))); + Analyze (First_Actual); + + else + Rewrite (First_Actual, Obj); + end if; + + Rewrite (Node_To_Replace, Call_Node); + Analyze (Node_To_Replace); + end Complete_Object_Operation; + + -------------------------------- + -- Transform_Object_Operation -- + -------------------------------- + + procedure Transform_Object_Operation + (Call_Node : out Node_Id; + Node_To_Replace : out Node_Id; + Subprog : Node_Id) + is + Parent_Node : constant Node_Id := Parent (N); + + Dummy : constant Node_Id := New_Copy (Obj); + -- Placeholder used as a first parameter in the call, replaced + -- eventually by the proper object. + + Actuals : List_Id; + Actual : Node_Id; + + begin + -- Common case covering 1) Call to a procedure and 2) Call to a + -- function that has some additional actuals. + + if (Nkind (Parent_Node) = N_Function_Call + or else + Nkind (Parent_Node) = 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_Tree (Subprog), + Parameter_Associations => Actuals); + + else + Call_Node := + Make_Function_Call (Loc, + Name => New_Copy_Tree (Subprog), + Parameter_Associations => Actuals); + + end if; + + -- Before analysis, the 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_Tree (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_Tree (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; + Hom : Entity_Id; + Hom_Ref : Node_Id; + Success : Boolean; + + begin + -- Loop through ancestor types, traverse the homonym chain of the + -- subprogram, and try out those homonyms whose first formal has the + -- class-wide type of the ancestor. + + -- Should we verify that it is declared in the same package as the + -- ancestor type ??? + + Anc_Type := Obj_Type; + + loop + Hom := Current_Entity (Subprog); + while Present (Hom) loop + if (Ekind (Hom) = E_Procedure + or else + Ekind (Hom) = E_Function) + and then Present (First_Formal (Hom)) + and then Etype (First_Formal (Hom)) = + Class_Wide_Type (Anc_Type) + 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 => False, + Success => Success, + Skip_First => True); + + if Success then + + -- Reformat into the proper call + + Complete_Object_Operation + (Call_Node => Call_Node, + Node_To_Replace => Node_To_Replace, + Subprog => Hom_Ref); + + return True; + end if; + end if; + + Hom := Homonym (Hom); + end loop; + + -- Examine other ancestor types + + exit when Etype (Anc_Type) = Anc_Type; + Anc_Type := Etype (Anc_Type); + end loop; + + -- Nothing matched + + return False; + end Try_Class_Wide_Operation; + + ----------------------------- + -- 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; + Prim_Op_Ref : Node_Id := Empty; + Success : Boolean := False; + Op_Exists : Boolean := False; + + 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. + + ----------------------------- + -- Valid_First_Argument_Of -- + ----------------------------- + + function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is + Typ : constant Entity_Id := Etype (First_Formal (Op)); + + begin + -- Simple case + + return Base_Type (Obj_Type) = Typ + + -- Prefix can be dereferenced + + or else + (Is_Access_Type (Obj_Type) + and then Designated_Type (Obj_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) = Obj_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). + + Elmt := First_Elmt (Primitive_Operations (Obj_Type)); + 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 + -- 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 (Abstract_Interface_Alias (Prim_Op)) + and then Present (DTC_Entity (Alias (Prim_Op))) + and then Etype (DTC_Entity (Alias (Prim_Op))) = RTE (RE_Tag) + then + goto Continue; + end if; + + if not Success then + Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog)); + + Set_Etype (Call_Node, Any_Type); + Set_Parent (Call_Node, Parent (Node_To_Replace)); + + Set_Name (Call_Node, Prim_Op_Ref); + + Analyze_One_Call + (N => Call_Node, + Nam => Prim_Op, + Report => False, + Success => Success, + Skip_First => True); + + if Success then + Op_Exists := True; + + -- If the operation is a procedure call, there can only + -- be one candidate and we found it. If it is a function + -- we must collect all interpretations, because there + -- may be several primitive operations that differ only + -- in the return type. + + if Nkind (Call_Node) = N_Procedure_Call_Statement then + exit; + end if; + end if; + + elsif Ekind (Prim_Op) = E_Function then + + -- Collect remaining function interpretations, to be + -- resolved from context. + + Add_One_Interp (Prim_Op_Ref, Prim_Op, Etype (Prim_Op)); + end if; + end if; + + <<Continue>> + Next_Elmt (Elmt); + end loop; + + if Op_Exists then + Complete_Object_Operation + (Call_Node => Call_Node, + Node_To_Replace => Node_To_Replace, + Subprog => Prim_Op_Ref); + end if; + + return Op_Exists; + end Try_Primitive_Operation; + + -- Start of processing for Try_Object_Operation + + begin + 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 Ekind (Obj_Type) = E_Incomplete_Type + and then From_With_Type (Obj_Type) + then + Obj_Type := Non_Limited_View (Obj_Type); + end if; + + if not Is_Tagged_Type (Obj_Type) then + return False; + end if; + + -- Analyze the actuals if node is know 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; + + Analyze_Expression (Obj); + + -- 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, + Subprog => Subprog); + + Set_Etype (New_Call_Node, Any_Type); + Set_Parent (New_Call_Node, Parent (Node_To_Replace)); + + return + 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); + end Try_Object_Operation; + +end Sem_Ch4; |