Allow gdb to find debug symbols file by build-id for PE file format also

This promotes BFD's struct elf_build_id to the generic struct bfd_build_id,
populated when an ELF or PE BFD is read.

gdb is updated to use that, and to use the build-id to find symbols for PE files
also.

There is currently no generic way to extract the build-id from an object file,
perhaps an option to objdump to do this might make sense?

On x86_64-pc-cygwin, gdb's sepdebug.exp changes:

-# of unsupported tests          1
+# of expected passes            90

I don't seem to get consistent testsuite runs on i686-linux-gnu, but there
don't appear to be any regressions.

bfd/ChangeLog:

2015-06-10  Jon Turney  <jon.turney@dronecode.org.uk>

	* elf-bfd.h : Remove struct elf_build_id.
	* bfd.c : Add struct bfd_build_id.
	* bfd-in2.h: Regenerate.
	* elf.c (elfobj_grok_gnu_build_id): Update to use bfd_build_id.
	* libpei.h: Add protoype and macros for
	bfd_XXi_slurp_codeview_record.
	* peXXigen.c (_bfd_XXi_slurp_codeview_record): Make public
	* peicode.h (pe_bfd_read_buildid): Add.
	(pe_bfd_object_p): Use pe_bfd_read_buildid().

gdb/ChangeLog:

2015-06-10  Jon Turney  <jon.turney@dronecode.org.uk>

	* build-id.c: Don't include elf-bfd.h.
	(build_id_bfd_get): Use bfd_build_id.
	(build_id_verify): Ditto.
	* build-id.h: Ditto.
	(find_separate_debug_file_by_buildid): Ditto.
	* python/py-objfile.c: Don't include elf-bfd.h.
	(objfpy_get_build_id) Use bfd_build_id.
	(objfpy_build_id_matches, objfpy_lookup_objfile_by_build_id): Ditto.
	* coffread.c: Include build-id.h.
	(coff_symfile_read): Try find_separate_debug_file_by_buildid.

gdb/doc/ChangeLog:

2015-06-10  Jon Turney  <jon.turney@dronecode.org.uk>

	* gdb.texinfo (Separate Debug Files): Document that PE is also
	supported.

gdb/testsuite/ChangeLog:

2015-06-10  Jon Turney  <jon.turney@dronecode.org.uk>

	* gdb.base/sepdebug.exp: Add EXEEXT where needed.
	* lib/gdb.exp (get_build_id): Teach how to extract build-id from a
	PE file.
	* lib/future.exp (gdb_find_objdump): Add gdb_find_objdump.

Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>

1 files changed, 9 insertions, 12 deletions

diff --git a/gdb/build-id.c b/gdb/build-id.c
index 8f7bbb4..ebf9f45 100644
--- a/gdb/build-id.c
+++ b/gdb/build-id.c
@@ -19,7 +19,6 @@
 
 #include "defs.h"
 #include "bfd.h"
-#include "elf-bfd.h"
 #include "gdb_bfd.h"
 #include "build-id.h"
 #include "gdb_vecs.h"
@@ -30,19 +29,17 @@
 
 /* See build-id.h.  */
 
-const struct elf_build_id *
+const struct bfd_build_id *
 build_id_bfd_get (bfd *abfd)
 {
-  if (!bfd_check_format (abfd, bfd_object)
-      || bfd_get_flavour (abfd) != bfd_target_elf_flavour
-      /* Although this is ELF_specific, it is safe to do in generic
-	 code because it does not rely on any ELF-specific symbols at
-	 link time, and if the ELF code is not available in BFD, then
-	 ABFD will not have the ELF flavour.  */
-      || elf_tdata (abfd)->build_id == NULL)
+  if (!bfd_check_format (abfd, bfd_object))
     return NULL;
 
-  return elf_tdata (abfd)->build_id;
+  if (abfd->build_id != NULL)
+    return abfd->build_id;
+
+  /* No build-id */
+  return NULL;
 }
 
 /* See build-id.h.  */
@@ -50,7 +47,7 @@ build_id_bfd_get (bfd *abfd)
 int
 build_id_verify (bfd *abfd, size_t check_len, const bfd_byte *check)
 {
-  const struct elf_build_id *found;
+  const struct bfd_build_id *found;
   int retval = 0;
 
   found = build_id_bfd_get (abfd);
@@ -139,7 +136,7 @@ build_id_to_debug_bfd (size_t build_id_len, const bfd_byte *build_id)
 char *
 find_separate_debug_file_by_buildid (struct objfile *objfile)
 {
-  const struct elf_build_id *build_id;
+  const struct bfd_build_id *build_id;
 
   build_id = build_id_bfd_get (objfile->obfd);
   if (build_id != NULL)