[PATCH 01/12] Handle another edge case for TLS variable lookups.

[John Baldwin <jhb@FreeBSD.org>]

This is similar to the change in
df22c1e5d53c38f38bce6072bb46de240f9e0e2b but applies to the main
object file.  The original change I encountered when testing TLS on
RISC-V for which I was unable to test TLS variables in the main
executable due to issues with compiler-generated debug info, so I only
checked for a backlink before walking the list of shared library
object files.

However, I ran into this issue again (of a separate debug object file
being passed to svr4_fetch_objfile_link_map) when testing TLS
variables on 32-bit arm.  To fix, move the check for a backlink
earlier before the check for the main object file.
---
 gdb/solib-svr4.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c
index 69f2991f5e6..aba476f6cf2 100644
--- a/gdb/solib-svr4.c
+++ b/gdb/solib-svr4.c
@@ -1449,15 +1449,15 @@ svr4_fetch_objfile_link_map (struct objfile *objfile)
   if (info->main_lm_addr == 0)
     solib_add (NULL, 0, auto_solib_add);
 
-  /* svr4_current_sos() will set main_lm_addr for the main executable.  */
-  if (objfile == current_program_space->symfile_object_file)
-    return info->main_lm_addr;
-
   /* If OBJFILE is a separate debug object file, look for the
      original object file.  */
   if (objfile->separate_debug_objfile_backlink != NULL)
     objfile = objfile->separate_debug_objfile_backlink;
 
+  /* svr4_current_sos() will set main_lm_addr for the main executable.  */
+  if (objfile == current_program_space->symfile_object_file)
+    return info->main_lm_addr;
+
   /* The other link map addresses may be found by examining the list
      of shared libraries.  */
   for (struct so_list *so : current_program_space->solibs ())
-- 
2.34.1