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>
This patch fixes gdb PR symtab/15597.
The bug is that the .gnu_debugaltlink section includes the build-id of
the alt file, but gdb does not use it.
This patch fixes the problem by changing gdb to do what it ought to
always have done: verify the build id of the file found using the
filename in .gnu_debugaltlink; and if that does not match, try to find
the correct debug file using the build-id and debug-file-directory.
This patch touches BFD. Previously, gdb had its own code for parsing
.gnu_debugaltlink; I changed it to use the BFD functions after those
were introduced. However, the BFD functions are incorrect -- they
assume that .gnu_debugaltlink is formatted like .gnu_debuglink.
However, it it is not. Instead, it consists of a file name followed
by the build-id -- no alignment, and the build-id is not a CRC.
Fixing this properly is a bit of a pain. But, because
separate_alt_debug_file_exists just has a FIXME for the build-id case,
I did not fix it properly. Instead I introduced a hack. This leaves
BFD working just as well as it did before my patch.
I'm willing to do something better here but I could use some guidance
as to what. It seems that the build-id code in BFD is largely punted
on.
FWIW gdb is the only user of bfd_get_alt_debug_link_info outside of
BFD itself.
I moved the build-id logic out of elfread.c and into a new file.
This seemed cleanest to me.
Writing a test case was a bit of a pain. I added a couple new
features to the DWARF assembler to handle this.
Built and regtested on x86-64 Fedora 18.
* bfd-in2.h: Rebuild.
* opncls.c (bfd_get_alt_debug_link_info): Add buildid_len
parameter. Change type of buildid_out. Update.
(get_alt_debug_link_info_shim): New function.
(bfd_follow_gnu_debuglink): Use it.
* Makefile.in (SFILES): Add build-id.c.
(HFILES_NO_SRCDIR): Add build-id.h.
* build-id.c: New file, largely from elfread.c. Modified
most functions.
* build-id.h: New file.
* dwarf2read.c (dwarf2_get_dwz_file): Update for change to
bfd_get_alt_debug_link_info. Verify dwz file's build-id.
Search for dwz file using build-id.
* elfread.c (build_id_bfd_get, build_id_verify)
(build_id_to_debug_filename, find_separate_debug_file): Remove.
* gdb.dwarf2/dwzbuildid.exp: New file.
* lib/dwarf.exp (Dwarf::_section): Add "flags" and "type"
parameters.
(Dwarf::_defer_output): Change "section" parameter to
"section_spec"; update.
(Dwarf::gnu_debugaltlink, Dwarf::_note, Dwarf::build_id): New
procs.
