[COMMITTED 30/42] ada: Improve retrieval of nominal unconstrained type in extended return

[Marc Poulhiès]

From: Piotr Trojanek <troja...@adacore.com>

When extended return statement declares object using an explicit subtype
indication, then it is better to recover the original unconstrained type using
the explicit subtype indication. This appears to be necessary for subtypes with
predicates.

gcc/ada/ChangeLog:

        * sem_ch3.adb (Check_Return_Subtype_Indication): Use type from
        explicit subtype indication, when possible.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/sem_ch3.adb | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/gcc/ada/sem_ch3.adb b/gcc/ada/sem_ch3.adb
index 98a8fa56391..f25941d72a8 100644
--- a/gcc/ada/sem_ch3.adb
+++ b/gcc/ada/sem_ch3.adb
@@ -4204,7 +4204,11 @@ package body Sem_Ch3 is
          --  to recover the nominal unconstrained type.
 
          if Is_Constr_Subt_For_U_Nominal (Obj_Typ) then
-            Obj_Typ := Etype (Obj_Typ);
+            if Nkind (Object_Definition (Obj_Decl)) = N_Subtype_Indication then
+               Obj_Typ := Entity (Subtype_Mark (Object_Definition (Obj_Decl)));
+            else
+               Obj_Typ := Etype (Obj_Typ);
+            end if;
             pragma Assert (not Is_Constrained (Obj_Typ));
          end if;
 
-- 
2.43.0