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, 0 deletions

diff --git a/bfd/bfd.c b/bfd/bfd.c
index ab410cb0bd..e60f3581a3 100644
--- a/bfd/bfd.c
+++ b/bfd/bfd.c
@@ -51,6 +51,12 @@ CODE_FRAGMENT
 .    bfd_plugin_no = 2
 .  };
 .
+.struct bfd_build_id
+.  {
+.    size_t size;
+.    bfd_byte data[1];
+.  };
+.
 .struct bfd
 .{
 .  {* The filename the application opened the BFD with.  *}
@@ -335,6 +341,9 @@ CODE_FRAGMENT
 .     struct objalloc *, but we use void * to avoid requiring the inclusion
 .     of objalloc.h.  *}
 .  void *memory;
+.
+.  {* For input BFDs, the build ID, if the object has one. *}
+.  const struct bfd_build_id *build_id;
 .};
 .
 .{* See note beside bfd_set_section_userdata.  *}