This patch fixes a compiler abort on a call that is initially overloaded,
when the resolved function returns the limited view of a type.
The folllowing must compile quietly:
gcc -c p.adb
---
with R;
package body P is
function Get (A : Q.Ptr) return Integer is
begin
return R.Conv (A.Get);
end;
end P;
---
with Q;
package P is
function Get (A : Q.Ptr) return Integer;
end P;
---
limited with R;
package Q is
type Int1 is limited interface;
function Get (Self : access Int1) return Integer is abstract;
type Int2 is limited interface and Int1;
function Get (Self : access Int2) return R.Rec2 is abstract;
type Ptr is access all Int2'Class;
end Q;
---
package R is
type Rec1 is tagged null record;
function Conv (Item : Rec1) return Integer;
type Rec2 is new Rec1 with null record;
end R;
Tested on x86_64-pc-linux-gnu, committed on trunk
2016-10-12 Ed Schonberg <[email protected]>
* sem_res.adb (Resolve_Call): If a function call returns a
limited view of a type replace it with the non-limited view,
which must be available when compiling call. This was already
done elsewhere for non-overloaded calls, but needs to be done
after resolution if function name is overloaded.
Index: sem_res.adb
===================================================================
--- sem_res.adb (revision 241024)
+++ sem_res.adb (working copy)
@@ -6034,6 +6034,15 @@
end;
else
+ -- If the function returns the limited view of type, the call must
+ -- appear in a context in which the non-limited view is available.
+ -- As is done in Try_Object_Operation, use the available view to
+ -- prevent back-end confusion.
+
+ if From_Limited_With (Etype (Nam)) then
+ Set_Etype (Nam, Available_View (Etype (Nam)));
+ end if;
+
Set_Etype (N, Etype (Nam));
end if;
