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src/gdb ChangeLog Makefile.in dwarf2read.c elf ...
- From: tromey at sourceware dot org
- To: gdb-cvs at sourceware dot org
- Date: Tue, 08 Oct 2013 19:56:16 +0000
- Subject: src/gdb ChangeLog Makefile.in dwarf2read.c elf ...
CVSROOT: /cvs/src
Module name: src
Changes by: tromey@sourceware.org 2013-10-08 19:56:16
Modified files:
gdb : ChangeLog Makefile.in dwarf2read.c elfread.c
gdb/testsuite : ChangeLog
gdb/testsuite/lib: dwarf.exp
Added files:
gdb : build-id.c build-id.h
gdb/testsuite/gdb.dwarf2: dwzbuildid.exp
Log message:
fix PR symtab/15597
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.
Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/build-id.c.diff?cvsroot=src&r1=NONE&r2=1.1
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/build-id.h.diff?cvsroot=src&r1=NONE&r2=1.1
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/ChangeLog.diff?cvsroot=src&r1=1.16083&r2=1.16084
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/Makefile.in.diff?cvsroot=src&r1=1.1270&r2=1.1271
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/dwarf2read.c.diff?cvsroot=src&r1=1.841&r2=1.842
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/elfread.c.diff?cvsroot=src&r1=1.162&r2=1.163
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/testsuite/ChangeLog.diff?cvsroot=src&r1=1.3827&r2=1.3828
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/testsuite/gdb.dwarf2/dwzbuildid.exp.diff?cvsroot=src&r1=NONE&r2=1.1
http://sourceware.org/cgi-bin/cvsweb.cgi/src/gdb/testsuite/lib/dwarf.exp.diff?cvsroot=src&r1=1.13&r2=1.14