ada: Error compiling reduction expression with overloaded reducer subprogram

In some cases involving a reduction expression with an overloaded reducer
subprogram, the accumulator type is not determined correctly. This can lead
to spurious compile-time errors.

gcc/ada/

	* exp_attr.adb (Expand_N_Attribute_Reference): In the case of a
	Reduce attribute reference, fix bugs in initializing Accum_Typ.
	The previous version was incorrect in the case where E1 refers to
	the first of multiple possible overload resolution candidates and
	that candidate does not turn out to be the right one. The previous
	version also had code to compute Accum_Typ via a different method
	if the initial computation turned out to yield a universal numeric
	type. Delete that initial computation and use the second method in
	all cases.

diff --git a/gcc/ada/exp_attr.adb b/gcc/ada/exp_attr.adb
index 7e71422eba3bc90a0d07b3906134b1055b42a289..2aac1063cc513ffb4aaf4b91825744a30570a31b 100644 (file)
--- a/gcc/ada/exp_attr.adb
+++ b/gcc/ada/exp_attr.adb
@@ -5982,7 +5982,7 @@ package body Exp_Attr is
             E2  : constant Node_Id    := Next (E1);
             Bnn : constant Entity_Id  := Make_Temporary (Loc, 'B', N);
 
-            Accum_Typ : Entity_Id;
+            Accum_Typ : Entity_Id := Empty;
             New_Loop  : Node_Id;
 
             function Build_Stat (Comp : Node_Id) return Node_Id;
@@ -6001,7 +6001,6 @@ package body Exp_Attr is
 
             begin
                if Nkind (E1) = N_Attribute_Reference then
-                  Accum_Typ := Entity (Prefix (E1));
                   Stat := Make_Assignment_Statement (Loc,
                             Name => New_Occurrence_Of (Bnn, Loc),
                             Expression => Make_Attribute_Reference (Loc,
@@ -6012,14 +6011,12 @@ package body Exp_Attr is
                                 Comp)));
 
                elsif Ekind (Entity (E1)) = E_Procedure then
-                  Accum_Typ := Etype (First_Formal (Entity (E1)));
                   Stat := Make_Procedure_Call_Statement (Loc,
                             Name => New_Occurrence_Of (Entity (E1), Loc),
                                Parameter_Associations => New_List (
                                  New_Occurrence_Of (Bnn, Loc),
                                  Comp));
                else
-                  Accum_Typ := Etype (Entity (E1));
                   Stat := Make_Assignment_Statement (Loc,
                             Name => New_Occurrence_Of (Bnn, Loc),
                             Expression => Make_Function_Call (Loc,
@@ -6080,12 +6077,9 @@ package body Exp_Attr is
                       Statements =>
                         New_List (Build_Stat (Relocate_Node (Expr))));
 
-                  --  If the reducer subprogram is a universal operator, then
-                  --  we still look at the context to find the type for now.
+                  --  Look at the context to find the type.
 
-                  if Is_Universal_Numeric_Type (Accum_Typ) then
-                     Accum_Typ := Etype (N);
-                  end if;
+                  Accum_Typ := Etype (N);
                end;
 
             else
@@ -6115,43 +6109,40 @@ package body Exp_Attr is
                       Statements => New_List (
                         Build_Stat (New_Occurrence_Of (Elem, Loc))));
 
-                  --  If the reducer subprogram is a universal operator, then
-                  --  we need to look at the prefix to find the type. This is
+                  --  Look at the prefix to find the type. This is
                   --  modeled on Analyze_Iterator_Specification in Sem_Ch5.
 
-                  if Is_Universal_Numeric_Type (Accum_Typ) then
-                     declare
-                        Ptyp : constant Entity_Id :=
-                                 Base_Type (Etype (Prefix (N)));
+                  declare
+                     Ptyp : constant Entity_Id :=
+                              Base_Type (Etype (Prefix (N)));
 
-                     begin
-                        if Is_Array_Type (Ptyp) then
-                           Accum_Typ := Component_Type (Ptyp);
-
-                        elsif Has_Aspect (Ptyp, Aspect_Iterable) then
-                           declare
-                              Element : constant Entity_Id :=
-                                          Get_Iterable_Type_Primitive
-                                            (Ptyp, Name_Element);
-                           begin
-                              if Present (Element) then
-                                 Accum_Typ := Etype (Element);
-                              end if;
-                           end;
-
-                        else
-                           declare
-                              Element : constant Node_Id :=
-                                          Find_Value_Of_Aspect
-                                            (Ptyp, Aspect_Iterator_Element);
-                           begin
-                              if Present (Element) then
-                                 Accum_Typ := Entity (Element);
-                              end if;
-                           end;
-                        end if;
-                     end;
-                  end if;
+                  begin
+                     if Is_Array_Type (Ptyp) then
+                        Accum_Typ := Component_Type (Ptyp);
+
+                     elsif Has_Aspect (Ptyp, Aspect_Iterable) then
+                        declare
+                           Element : constant Entity_Id :=
+                                       Get_Iterable_Type_Primitive
+                                         (Ptyp, Name_Element);
+                        begin
+                           if Present (Element) then
+                              Accum_Typ := Etype (Element);
+                           end if;
+                        end;
+
+                     else
+                        declare
+                           Element : constant Node_Id :=
+                                       Find_Value_Of_Aspect
+                                         (Ptyp, Aspect_Iterator_Element);
+                        begin
+                           if Present (Element) then
+                              Accum_Typ := Entity (Element);
+                           end if;
+                        end;
+                     end if;
+                  end;
                end;
             end if;