[gcc r14-1274] ada: Fix handling of Global contracts inside generic subprograms

[Marc Poulhi?s <dkm@gcc.gnu.org>]

https://gcc.gnu.org/g:fd3eff65551876a04febca1621d7d19f9390aab6

commit r14-1274-gfd3eff65551876a04febca1621d7d19f9390aab6
Author: Piotr Trojanek <trojanek@adacore.com>
Date:   Tue Oct 5 15:29:44 2021 +0200

    ada: Fix handling of Global contracts inside generic subprograms
    
    Routine Get_Argument works differently for generic units (as explained
    in its comment), but it failed to reliably detect such units when their
    kind is temporarily made non-generic (for resolving recursive calls, as
    explained in the comment at the end of Is_Generic_Declaration_Or_Body).
    
    With this patch the frontend will look at the decorated expression of
    the Global contract attached to the Global aspect; previously it was
    looking at the undecorated expression attached to the corresponding
    pragma.
    
    gcc/ada/
    
            * sem_prag.adb (Get_Argument): Improve detection of generic units.

Diff:
---
 gcc/ada/sem_prag.adb | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/gcc/ada/sem_prag.adb b/gcc/ada/sem_prag.adb
index d66e5612135..96ea17209f3 100644
--- a/gcc/ada/sem_prag.adb
+++ b/gcc/ada/sem_prag.adb
@@ -31650,7 +31650,9 @@ package body Sem_Prag is
       --  to save the global references in the generic context.
 
       if From_Aspect_Specification (Prag)
-        and then (Present (Context_Id) and then Is_Generic_Unit (Context_Id))
+        and then Present (Context_Id)
+        and then
+          Is_Generic_Declaration_Or_Body (Unit_Declaration_Node (Context_Id))
       then
          return Corresponding_Aspect (Prag);