[binutils-gdb] segv in debug_write_type

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=049a70652a9a1cca7d3f3445f6d649fb125ecabd

commit 049a70652a9a1cca7d3f3445f6d649fb125ecabd
Author: Alan Modra <amodra@gmail.com>
Date:   Mon Oct 6 13:01:19 2025 +1030

    segv in debug_write_type
    
    In commit 6c3458a8b7ee I claimed that u.kenum is always non-NULL,
    which is true for debug_make_enum_type, but not for enums made by
    debug_make_undefined_tagged_type.  Fix that oversight
    
            PR 32829
            * debug.c (debug_write_type): Handle NULL u.kenum.
            (debug_type_samep): Likewise.

Diff:
---
 binutils/debug.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/binutils/debug.c b/binutils/debug.c
index 465b18e7c0a..78cdd3ceca8 100644
--- a/binutils/debug.c
+++ b/binutils/debug.c
@@ -2554,8 +2554,9 @@ debug_write_type (struct debug_handle *info,
     case DEBUG_KIND_UNION_CLASS:
       return debug_write_class_type (info, fns, fhandle, type, tag);
     case DEBUG_KIND_ENUM:
-      return (*fns->enum_type) (fhandle, tag, type->u.kenum->names,
-				type->u.kenum->values);
+      return (*fns->enum_type) (fhandle, tag,
+				type->u.kenum ? type->u.kenum->names : NULL,
+				type->u.kenum ? type->u.kenum->values : NULL);
     case DEBUG_KIND_POINTER:
       if (! debug_write_type (info, fns, fhandle, type->u.kpointer,
 			      (struct debug_name *) NULL))
@@ -3094,7 +3095,11 @@ debug_type_samep (struct debug_handle *info, struct debug_type_s *t1,
       break;
 
     case DEBUG_KIND_ENUM:
-      if (t1->u.kenum->names == NULL)
+      if (t1->u.kenum == NULL)
+	ret = t2->u.kenum == NULL;
+      else if (t2->u.kenum == NULL)
+	ret = false;
+      else if (t1->u.kenum->names == NULL)
 	ret = t2->u.kenum->names == NULL;
       else if (t2->u.kenum->names == NULL)
 	ret = false;