[gcc r17-1308] ada: Attribute reference in subunit causes compiler Assertion_Error

[Marc Poulhies]

https://gcc.gnu.org/g:1025bb39ef4bf810ff996530ba49955749242824

commit r17-1308-g1025bb39ef4bf810ff996530ba49955749242824
Author: Steve Baird <baird@adacore.com>
Date:   Wed May 13 15:56:17 2026 -0700

    ada: Attribute reference in subunit causes compiler Assertion_Error
    
    In the case of a separate subunit subprogram body, do not take a path that
    is intended for the case where there is no enclosing declaration list.
    The subunit's stub has an enclosing declaration list.
    
    gcc/ada/ChangeLog:
    
            * exp_attr.adb (Build_And_Insert_Type_Attr_Subp): Test for subunit case before
            concluding that a subprogram body has no enclosing declaration list.

Diff:
---
 gcc/ada/exp_attr.adb | 1 +
 1 file changed, 1 insertion(+)

diff --git a/gcc/ada/exp_attr.adb b/gcc/ada/exp_attr.adb
index 32b8297cd580..d1b9510ce120 100644
--- a/gcc/ada/exp_attr.adb
+++ b/gcc/ada/exp_attr.adb
@@ -2197,6 +2197,7 @@ package body Exp_Attr is
                    (No (Insertion_Point)
                      or else List_Containing (Insertion_Point) /=
                        Declarations (Ancestor))
+                 and then Nkind (Parent (Ancestor)) /= N_Subunit
                then
                   Insertion_Point := First (Declarations (Ancestor));
                   Skip_Non_Source_Subps;