From: Alan Modra <amodra@gmail.com>
Date: Wed, 28 May 2025 08:50:17 +0000 (+0930)
Subject: PR 33029 segv in dwarf2_finish with --gdwarf-5
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f601ffb52199a883f16df385b73a14e756b3e19a;p=thirdparty%2Fbinutils-gdb.git

PR 33029 segv in dwarf2_finish with --gdwarf-5

Specifying --gdwarf-5 with a source lacking a ".file 0" directive
results in this segfault.

	* dwarf2dbg.c (out_debug_str): Use files[1] if files[0] is
	empty regardless of dwarf level.
---

diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
index fd1f96d80c5..a40fe6967d5 100644
--- a/gas/dwarf2dbg.c
+++ b/gas/dwarf2dbg.c
@@ -3019,6 +3019,11 @@ out_debug_str (segT str_seg, symbolS **name_sym, symbolS **comp_dir_sym,
   int len;
   int first_file = DWARF2_LINE_VERSION > 4 ? 0 : 1;
 
+  if (files_in_use == 0)
+    abort ();
+  if (first_file == 0 && files[first_file].filename == NULL)
+    first_file = 1;
+
   subseg_set (str_seg, 0);
 
   /* DW_AT_name.  We don't have the actual file name that was present
@@ -3026,8 +3031,7 @@ out_debug_str (segT str_seg, symbolS **name_sym, symbolS **comp_dir_sym,
      We're not supposed to get called unless at least one line number
      entry was emitted, so this should always be defined.  */
   *name_sym = symbol_temp_new_now_octets ();
-  if (files_in_use == 0)
-    abort ();
+
   if (files[first_file].dir)
     {
       char *dirname = remap_debug_filename (dirs[files[first_file].dir]);