old-cross-binutils/gdb/testsuite/gdb.dwarf2/dwzbuildid.exp
Tom Tromey dc294be54c 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.
2013-10-08 19:56:15 +00:00

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# Copyright 2013 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
load_lib dwarf.exp
# This test can only be run on targets which support DWARF-2 and use gas.
if {![dwarf2_support]} {
return 0
}
# No remote host testing either.
if {[is_remote host]} {
return 0
}
# Lots of source files since we test a few cases and make new files
# for each.
# The tests are:
# ok - the main file refers to a dwz and the buildids match
# mismatch - the buildids do not match
# fallback - the buildids do not match but a match is found via buildid
standard_testfile main.c \
dwzbuildid-ok-base.S dwzbuildid-ok-sep.S \
dwzbuildid-mismatch-base.S dwzbuildid-mismatch-sep.S \
dwzbuildid-fallback-base.S dwzbuildid-fallback-sep.S \
dwzbuildid-fallback-ok.S
# Write some assembly that just has a .gnu_debugaltlink section.
proc write_just_debugaltlink {filename dwzname buildid} {
set asm_file [standard_output_file $filename]
Dwarf::assemble $asm_file {
upvar dwzname dwzname
upvar buildid buildid
gnu_debugaltlink $dwzname $buildid
# Only the DWARF reader checks .gnu_debugaltlink, so make sure
# there is a bit of DWARF in here.
cu {} {
compile_unit {{language @DW_LANG_C}} {
}
}
}
}
# Write some DWARF that also sets the buildid.
proc write_dwarf_file {filename buildid {value 99}} {
set asm_file [standard_output_file $filename]
Dwarf::assemble $asm_file {
declare_labels partial_label double_label int_label int_label2
upvar buildid buildid
upvar value value
build_id $buildid
cu {} {
compile_unit {{language @DW_LANG_C}} {
int_label2: base_type {
{name int}
{byte_size 4 sdata}
{encoding @DW_ATE_signed}
}
constant {
{name the_int}
{type :$int_label2}
{const_value $value data1}
}
}
}
}
}
if { [gdb_compile ${srcdir}/${subdir}/${srcfile} ${binfile}1.o \
object {nodebug}] != "" } {
return -1
}
# The values don't really matter, just whether they are equal.
set ok_prefix 01
set ok_suffix 0203040506
set ok_suffix2 02030405ff
set ok_buildid ${ok_prefix}${ok_suffix}
set ok_buildid2 ${ok_prefix}${ok_suffix2}
set bad_buildid ffffffffffff
set outdir [standard_output_file {}]
set basedir $outdir/.build-id
file mkdir $basedir $basedir/$ok_prefix
# Test where the separate debuginfo's buildid matches.
write_just_debugaltlink $srcfile2 ${binfile}3.o $ok_buildid
write_dwarf_file $srcfile3 $ok_buildid
# Test where the separate debuginfo's buildid does not match.
write_just_debugaltlink $srcfile4 ${binfile}5.o $ok_buildid
write_dwarf_file $srcfile5 $bad_buildid
# Test where the separate debuginfo's buildid does not match, but then
# we find a match in the .build-id directory.
write_just_debugaltlink $srcfile6 ${binfile}7.o $ok_buildid2
# Use 77 as the value so that if we load the bad debuginfo, we will
# see the wrong result.
write_dwarf_file $srcfile7 $bad_buildid 77
write_dwarf_file $srcfile8 $ok_buildid2
# Compile everything.
for {set i 2} {$i <= 8} {incr i} {
if {[gdb_compile [standard_output_file [set srcfile$i]] \
${binfile}$i.o object nodebug] != ""} {
return -1
}
}
# Copy a file into the .build-id place for the "fallback" test.
file copy -force -- ${binfile}8.o $basedir/$ok_prefix/$ok_suffix2.debug
# Link the executables.
if {[gdb_compile [list ${binfile}1.o ${binfile}2.o] ${binfile}-ok \
executable {}] != ""} {
return -1
}
if {[gdb_compile [list ${binfile}1.o ${binfile}4.o] ${binfile}-mismatch \
executable {}] != ""} {
return -1
}
if {[gdb_compile [list ${binfile}1.o ${binfile}6.o] ${binfile}-fallback \
executable {}] != ""} {
return -1
}
foreach testname {ok mismatch fallback} {
with_test_prefix $testname {
gdb_exit
gdb_start
gdb_reinitialize_dir $srcdir/$subdir
gdb_test_no_output "set debug-file-directory $outdir"
gdb_load ${binfile}-${testname}
if {[runto_main]} {
if {$testname == "mismatch"} {
gdb_test "print the_int" \
"No symbol table is loaded.*"
} else {
gdb_test "print the_int" " = 99"
}
}
}
}