Within an instance, a spurious ambiguity may arise between a local subprogram
and the actual for a formal subprogram of the enclosing instance. Previously
the code only handled spurious ambiguities between two actuals or two local
subprograms.
The following must compile quietly:
---
function Cutdown (A1, B1, A2, B2 : Boolean) return Boolean is
generic
type T1 is private;
A1, B1 : T1;
type T2 is private;
A2, B2 : T2;
with function Eq (X1, Y1 : T1) return Boolean;
package G1 is
generic
with function Eq (X2, Y2 : T2) return Boolean;
function G2 return Boolean;
end G1;
package body G1 is
function G2 return Boolean is
begin
return Eq (X1 => A1, Y1 => B1) and Eq (X2 => A2, Y2 => B2);
end G2;
end G1;
package I1 is new G1 (Boolean, A1, B1, Boolean, A2, B2, "=");
function I2 is new I1.G2 ("=");
begin
return I2;
end Cutdown;
Tested on x86_64-pc-linux-gnu, committed on trunk
2011-08-29 Ed Schonberg <schonb...@adacore.com>
* sem_type.adb (Collect_Interps): Within an instance, collect a homonym
that comes from an enclosing scope if it is not the renaming of an
actual, to handle properly a spurious ambiguity in an instance.
Index: sem_type.adb
===================================================================
--- sem_type.adb (revision 178155)
+++ sem_type.adb (working copy)
@@ -621,10 +621,15 @@
-- A homograph in the same scope can occur within an
-- instantiation, the resulting ambiguity has to be
- -- resolved later.
+ -- resolved later. The homographs may both be local
+ -- functions or actuals, or may be declared at different
+ -- levels within the instance. The renaming of an actual
+ -- within the instance must not be included.
- if Scope (H) = Scope (Ent)
+ if (Scope (H) = Scope (Ent)
+ or else Scope (H) = Scope (Scope (Ent)))
and then In_Instance
+ and then H /= Renamed_Entity (Ent)
and then not Is_Inherited_Operation (H)
then
All_Interp.Table (All_Interp.Last) :=
