From 6e73e3ab00f849dc7facec6ad9c359e32ec67122 Mon Sep 17 00:00:00 2001 From: Arnaud Charlet Date: Wed, 8 Dec 2004 12:48:22 +0100 Subject: [PATCH] sem_ch4.adb (Process_Implicit_Dereference_Prefix): New subprogram used to record an implicit dereference as a read operation on... * sem_ch4.adb (Process_Implicit_Dereference_Prefix): New subprogram used to record an implicit dereference as a read operation on its prefix when operating under -gnatc. Necessary to avoid spurious 'variable assigned but never read' warnings in that mode. (Process_Indexed_Component, Analyze_Selected_Component): When the prefix is a non-overloaded implicit dereference, call the above subprogram to ensure proper recording of references. From-SVN: r91892 --- gcc/ada/sem_ch4.adb | 111 +++++++++++++++++++++++++++----------------- 1 file changed, 68 insertions(+), 43 deletions(-) diff --git a/gcc/ada/sem_ch4.adb b/gcc/ada/sem_ch4.adb index 2629396cf1b..4c01fdb0809 100644 --- a/gcc/ada/sem_ch4.adb +++ b/gcc/ada/sem_ch4.adb @@ -145,25 +145,25 @@ package body Sem_Ch4 is (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id); - -- For the four varieties of concatenation. + -- 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. + -- Ditto for equality operators procedure Find_Boolean_Types (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id); - -- Ditto for binary logical operations. + -- 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. + -- Find consistent interpretation for operand of negation operator procedure Find_Non_Universal_Interpretations (N : Node_Id; @@ -181,7 +181,7 @@ package body Sem_Ch4 is (R : Node_Id; Op_Id : Entity_Id; N : Node_Id); - -- Unary arithmetic types: plus, minus, abs. + -- Unary arithmetic types: plus, minus, abs procedure Check_Arithmetic_Pair (T1, T2 : Entity_Id; @@ -212,6 +212,14 @@ package body Sem_Ch4 is -- 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), record that P + -- 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. @@ -1235,7 +1243,7 @@ package body Sem_Ch4 is End_Interp_List; - -- Error if no interpretation of the prefix has an access type. + -- Error if no interpretation of the prefix has an access type if Etype (N) = Any_Type then Error_Msg_N @@ -1371,7 +1379,7 @@ package body Sem_Ch4 is Exp : Node_Id; Array_Type : Entity_Id; Index : Node_Id; - Entry_Family : Entity_Id; + Pent : Entity_Id := Empty; begin Exp := First (Exprs); @@ -1382,38 +1390,32 @@ package body Sem_Ch4 is else Array_Type := Etype (P); - -- Prefix must be appropriate for an array type. - -- Dereference the prefix if it is an access type. + 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 (Is_Entity_Name (P) - and then - Ekind (Entity (P)) = E_Entry_Family) - or else - (Nkind (P) = N_Selected_Component - and then - Is_Entity_Name (Selector_Name (P)) - and then - Ekind (Entity (Selector_Name (P))) = E_Entry_Family) - then - if Is_Entity_Name (P) then - Entry_Family := Entity (P); - else - Entry_Family := Entity (Selector_Name (P)); - end if; - + 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 (Entry_Family)) + (Exp, Entry_Index_Type (Pent)) then Error_Msg_N ("invalid index type in entry name", N); @@ -1439,13 +1441,7 @@ package body Sem_Ch4 is else if Nkind (Parent (N)) = N_Requeue_Statement - and then - ((Is_Entity_Name (P) - and then Ekind (Entity (P)) = E_Entry) - or else - (Nkind (P) = N_Selected_Component - and then Is_Entity_Name (Selector_Name (P)) - and then Ekind (Entity (Selector_Name (P))) = E_Entry)) + and then Present (Pent) and then Ekind (Pent) = E_Entry then Error_Msg_N ("REQUEUE does not permit parameters", First (Exprs)); @@ -2471,6 +2467,7 @@ package body Sem_Ch4 is 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; @@ -2522,6 +2519,14 @@ package body Sem_Ch4 is 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); @@ -3961,10 +3966,9 @@ package body Sem_Ch4 is Find_Non_Universal_Interpretations (N, R, Op_Id, T1); - if Etype (N) = Any_Type then - - -- Operator was not visible. + -- Case of operator was not visible, Etype still set to Any_Type + if Etype (N) = Any_Type then Found := False; end if; end if; @@ -4353,6 +4357,27 @@ package body Sem_Ch4 is 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 Operating_Mode = Check_Semantics and then Present (E) 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 -- -------------------------------- @@ -4540,7 +4565,7 @@ package body Sem_Ch4 is if No (It.Nam) then - -- Removal of abstract operation left no viable candidate. + -- Removal of abstract operation left no viable candidate Set_Etype (N, Any_Type); Error_Msg_Sloc := Sloc (Abstract_Op); @@ -4886,14 +4911,14 @@ package body Sem_Ch4 is (Call_Node : Node_Id; Node_To_Replace : Node_Id) return Boolean is - Dummy : Node_Id; - Elmt : Elmt_Id; - Prim_Op : Entity_Id; - Prim_Op_Ref : Node_Id; - Success : Boolean; + Dummy : Node_Id; + Elmt : Elmt_Id; + Prim_Op : Entity_Id; + Prim_Op_Ref : Node_Id; + Success : Boolean; begin - -- Look for the subprogram in the list of primitive operations. + -- Look for the subprogram in the list of primitive operations Elmt := First_Elmt (Primitive_Operations (Obj_Type)); while Present (Elmt) loop -- 2.30.2