[gcc r12-972] Detect illegal conditions in Raise_xxx_Error nodes

[Eric Botcazou <ebotcazou@gcc.gnu.org>]

https://gcc.gnu.org/g:6fdacaf4b00619ad139ecf101cbb0136dcdd8c3a

commit r12-972-g6fdacaf4b00619ad139ecf101cbb0136dcdd8c3a
Author: Piotr Trojanek <trojanek@adacore.com>
Date:   Fri May 21 11:30:26 2021 +0200

    Detect illegal conditions in Raise_xxx_Error nodes
    
    Enforce comment from sinfo.ads about the Condition field in N_Raise_xxx_Error
    nodes. Only an extra sanity check; the behaviour is not affected.
    
    gcc/ada/
            * gcc-interface/trans.c (Raise_Error_to_gnu): Add an assertion.

Diff:
---
 gcc/ada/gcc-interface/trans.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/gcc/ada/gcc-interface/trans.c b/gcc/ada/gcc-interface/trans.c
index 289a2efcaf1..ee014a35cc2 100644
--- a/gcc/ada/gcc-interface/trans.c
+++ b/gcc/ada/gcc-interface/trans.c
@@ -6159,7 +6159,12 @@ Raise_Error_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p)
 	}
     }
   else
-    gnu_result = build1 (NULL_EXPR, *gnu_result_type_p, gnu_result);
+    {
+      /* The condition field must not be present when the node is used as an
+	 expression form.  */
+      gigi_checking_assert (No (gnat_cond));
+      gnu_result = build1 (NULL_EXPR, *gnu_result_type_p, gnu_result);
+    }
 
   return gnu_result;
 }