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authorTom Tromey <tromey@redhat.com>2013-10-08 19:56:15 +0000
committerTom Tromey <tromey@redhat.com>2013-10-08 19:56:15 +0000
commitdc294be54c96414035eed7d53dafdea0a6f31a72 (patch)
treee2ec6dd2f5754858a562b4b7105ab16fd5b302af /gdb/testsuite
parent5bb7df2edfeb80282ce424bc0d32f07713e24220 (diff)
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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.
Diffstat (limited to 'gdb/testsuite')
-rw-r--r--gdb/testsuite/ChangeLog10
-rw-r--r--gdb/testsuite/gdb.dwarf2/dwzbuildid.exp170
-rw-r--r--gdb/testsuite/lib/dwarf.exp62
3 files changed, 237 insertions, 5 deletions
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 4c15ae8..3e5e970 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,13 @@
+2013-10-08 Tom Tromey <tromey@redhat.com>
+
+ * 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 Joel Brobecker <brobecker@adacore.com>
* gdb.ada/mi_catch_ex.exp: Make "mi_execute_to" test names unique.
diff --git a/gdb/testsuite/gdb.dwarf2/dwzbuildid.exp b/gdb/testsuite/gdb.dwarf2/dwzbuildid.exp
new file mode 100644
index 0000000..e6ae881
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dwzbuildid.exp
@@ -0,0 +1,170 @@
+# 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"
+ }
+ }
+ }
+}
diff --git a/gdb/testsuite/lib/dwarf.exp b/gdb/testsuite/lib/dwarf.exp
index 5264def..c28b986 100644
--- a/gdb/testsuite/lib/dwarf.exp
+++ b/gdb/testsuite/lib/dwarf.exp
@@ -523,20 +523,27 @@ namespace eval Dwarf {
}
}
- proc _section {name} {
- _emit " .section $name"
+ proc _section {name {flags ""} {type ""}} {
+ if {$flags == "" && $type == ""} {
+ _emit " .section $name"
+ } elseif {$type == ""} {
+ _emit " .section $name, \"$flags\""
+ } else {
+ _emit " .section $name, \"$flags\", %$type"
+ }
}
- proc _defer_output {section body} {
+ # SECTION_SPEC is a list of arguments to _section.
+ proc _defer_output {section_spec body} {
variable _defer
variable _deferred_output
set old_defer $_defer
- set _defer $section
+ set _defer [lindex $section_spec 0]
if {![info exists _deferred_output($_defer)]} {
set _deferred_output($_defer) ""
- _section $section
+ eval _section $section_spec
}
uplevel $body
@@ -948,6 +955,51 @@ namespace eval Dwarf {
unset the_array(_)
}
+ # Emit a .gnu_debugaltlink section with the given file name and
+ # build-id. The buildid should be represented as a hexadecimal
+ # string, like "ffeeddcc".
+ proc gnu_debugaltlink {filename buildid} {
+ _defer_output .gnu_debugaltlink {
+ _op .ascii [_quote $filename]
+ foreach {a b} [split $buildid {}] {
+ _op .byte 0x$a$b
+ }
+ }
+ }
+
+ proc _note {type name hexdata} {
+ set namelen [expr [string length $name] + 1]
+
+ # Name size.
+ _op .4byte $namelen
+ # Data size.
+ _op .4byte [expr [string length $hexdata] / 2]
+ # Type.
+ _op .4byte $type
+ # The name.
+ _op .ascii [_quote $name]
+ # Alignment.
+ set align 2
+ set total [expr {($namelen + (1 << $align) - 1) & (-1 << $align)}]
+ for {set i $namelen} {$i < $total} {incr i} {
+ _op .byte 0
+ }
+ # The data.
+ foreach {a b} [split $hexdata {}] {
+ _op .byte 0x$a$b
+ }
+ }
+
+ # Emit a note section holding the given build-id.
+ proc build_id {buildid} {
+ _defer_output {.note.gnu.build-id a note} {
+ # From elf/common.h.
+ set NT_GNU_BUILD_ID 3
+
+ _note $NT_GNU_BUILD_ID GNU $buildid
+ }
+ }
+
# The top-level interface to the DWARF assembler.
# FILENAME is the name of the file where the generated assembly
# code is written.