2018-02-10 07:44:59 +08:00
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/* Path manipulation routines for GDB and gdbserver.
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2021-01-01 16:03:39 +08:00
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Copyright (C) 1986-2021 Free Software Foundation, Inc.
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2018-02-10 07:44:59 +08:00
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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2019-01-28 03:51:36 +08:00
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#ifndef COMMON_PATHSTUFF_H
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#define COMMON_PATHSTUFF_H
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2018-02-10 07:44:59 +08:00
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Rename common to gdbsupport
This is the next patch in the ongoing series to move gdbsever to the
top level.
This patch just renames the "common" directory. The idea is to do
this move in two parts: first rename the directory (this patch), then
move the directory to the top. This approach makes the patches a bit
more tractable.
I chose the name "gdbsupport" for the directory. However, as this
patch was largely written by sed, we could pick a new name without too
much difficulty.
Tested by the buildbot.
gdb/ChangeLog
2019-07-09 Tom Tromey <tom@tromey.com>
* contrib/ari/gdb_ari.sh: Change common to gdbsupport.
* configure: Rebuild.
* configure.ac: Change common to gdbsupport.
* gdbsupport: Rename from common.
* acinclude.m4: Change common to gdbsupport.
* Makefile.in (CONFIG_SRC_SUBDIR, COMMON_SFILES)
(HFILES_NO_SRCDIR, stamp-version, ALLDEPFILES): Change common to
gdbsupport.
* aarch64-tdep.c, ada-lang.c, ada-lang.h, agent.c, alloc.c,
amd64-darwin-tdep.c, amd64-dicos-tdep.c, amd64-fbsd-nat.c,
amd64-fbsd-tdep.c, amd64-linux-nat.c, amd64-linux-tdep.c,
amd64-nbsd-tdep.c, amd64-obsd-tdep.c, amd64-sol2-tdep.c,
amd64-tdep.c, amd64-windows-tdep.c, arch-utils.c,
arch/aarch64-insn.c, arch/aarch64.c, arch/aarch64.h, arch/amd64.c,
arch/amd64.h, arch/arm-get-next-pcs.c, arch/arm-linux.c,
arch/arm.c, arch/i386.c, arch/i386.h, arch/ppc-linux-common.c,
arch/riscv.c, arch/riscv.h, arch/tic6x.c, arm-tdep.c, auto-load.c,
auxv.c, ax-gdb.c, ax-general.c, ax.h, breakpoint.c, breakpoint.h,
btrace.c, btrace.h, build-id.c, build-id.h, c-lang.h, charset.c,
charset.h, cli/cli-cmds.c, cli/cli-cmds.h, cli/cli-decode.c,
cli/cli-dump.c, cli/cli-option.h, cli/cli-script.c,
coff-pe-read.c, command.h, compile/compile-c-support.c,
compile/compile-c.h, compile/compile-cplus-symbols.c,
compile/compile-cplus-types.c, compile/compile-cplus.h,
compile/compile-loc2c.c, compile/compile.c, completer.c,
completer.h, contrib/ari/gdb_ari.sh, corefile.c, corelow.c,
cp-support.c, cp-support.h, cp-valprint.c, csky-tdep.c, ctf.c,
darwin-nat.c, debug.c, defs.h, disasm-selftests.c, disasm.c,
disasm.h, dtrace-probe.c, dwarf-index-cache.c,
dwarf-index-cache.h, dwarf-index-write.c, dwarf2-frame.c,
dwarf2expr.c, dwarf2loc.c, dwarf2read.c, event-loop.c,
event-top.c, exceptions.c, exec.c, extension.h, fbsd-nat.c,
features/aarch64-core.c, features/aarch64-fpu.c,
features/aarch64-pauth.c, features/aarch64-sve.c,
features/i386/32bit-avx.c, features/i386/32bit-avx512.c,
features/i386/32bit-core.c, features/i386/32bit-linux.c,
features/i386/32bit-mpx.c, features/i386/32bit-pkeys.c,
features/i386/32bit-segments.c, features/i386/32bit-sse.c,
features/i386/64bit-avx.c, features/i386/64bit-avx512.c,
features/i386/64bit-core.c, features/i386/64bit-linux.c,
features/i386/64bit-mpx.c, features/i386/64bit-pkeys.c,
features/i386/64bit-segments.c, features/i386/64bit-sse.c,
features/i386/x32-core.c, features/riscv/32bit-cpu.c,
features/riscv/32bit-csr.c, features/riscv/32bit-fpu.c,
features/riscv/64bit-cpu.c, features/riscv/64bit-csr.c,
features/riscv/64bit-fpu.c, features/tic6x-c6xp.c,
features/tic6x-core.c, features/tic6x-gp.c, filename-seen-cache.h,
findcmd.c, findvar.c, fork-child.c, gcore.c, gdb_bfd.c, gdb_bfd.h,
gdb_proc_service.h, gdb_regex.c, gdb_select.h, gdb_usleep.c,
gdbarch-selftests.c, gdbthread.h, gdbtypes.h, gnu-nat.c,
go32-nat.c, guile/guile.c, guile/scm-ports.c,
guile/scm-safe-call.c, guile/scm-type.c, i386-fbsd-nat.c,
i386-fbsd-tdep.c, i386-go32-tdep.c, i386-linux-nat.c,
i386-linux-tdep.c, i386-tdep.c, i387-tdep.c,
ia64-libunwind-tdep.c, ia64-linux-nat.c, inf-child.c,
inf-ptrace.c, infcall.c, infcall.h, infcmd.c, inferior-iter.h,
inferior.c, inferior.h, inflow.c, inflow.h, infrun.c, infrun.h,
inline-frame.c, language.h, linespec.c, linux-fork.c, linux-nat.c,
linux-tdep.c, linux-thread-db.c, location.c, machoread.c,
macrotab.h, main.c, maint.c, maint.h, memattr.c, memrange.h,
mi/mi-cmd-break.h, mi/mi-cmd-env.c, mi/mi-cmd-stack.c,
mi/mi-cmd-var.c, mi/mi-interp.c, mi/mi-main.c, mi/mi-parse.h,
minsyms.c, mips-linux-tdep.c, namespace.h,
nat/aarch64-linux-hw-point.c, nat/aarch64-linux-hw-point.h,
nat/aarch64-linux.c, nat/aarch64-sve-linux-ptrace.c,
nat/amd64-linux-siginfo.c, nat/fork-inferior.c,
nat/linux-btrace.c, nat/linux-btrace.h, nat/linux-namespaces.c,
nat/linux-nat.h, nat/linux-osdata.c, nat/linux-personality.c,
nat/linux-procfs.c, nat/linux-ptrace.c, nat/linux-ptrace.h,
nat/linux-waitpid.c, nat/mips-linux-watch.c,
nat/mips-linux-watch.h, nat/ppc-linux.c, nat/x86-dregs.c,
nat/x86-dregs.h, nat/x86-linux-dregs.c, nat/x86-linux.c,
nto-procfs.c, nto-tdep.c, objfile-flags.h, objfiles.c, objfiles.h,
obsd-nat.c, observable.h, osdata.c, p-valprint.c, parse.c,
parser-defs.h, ppc-linux-nat.c, printcmd.c, probe.c, proc-api.c,
procfs.c, producer.c, progspace.h, psymtab.h,
python/py-framefilter.c, python/py-inferior.c, python/py-ref.h,
python/py-type.c, python/python.c, record-btrace.c, record-full.c,
record.c, record.h, regcache-dump.c, regcache.c, regcache.h,
remote-fileio.c, remote-fileio.h, remote-sim.c, remote.c,
riscv-tdep.c, rs6000-aix-tdep.c, rust-exp.y, s12z-tdep.c,
selftest-arch.c, ser-base.c, ser-event.c, ser-pipe.c, ser-tcp.c,
ser-unix.c, skip.c, solib-aix.c, solib-target.c, solib.c,
source-cache.c, source.c, source.h, sparc-nat.c, spu-linux-nat.c,
stack.c, stap-probe.c, symfile-add-flags.h, symfile.c, symfile.h,
symtab.c, symtab.h, target-descriptions.c, target-descriptions.h,
target-memory.c, target.c, target.h, target/waitstatus.c,
target/waitstatus.h, thread-iter.h, thread.c, tilegx-tdep.c,
top.c, top.h, tracefile-tfile.c, tracefile.c, tracepoint.c,
tracepoint.h, tui/tui-io.c, ui-file.c, ui-out.h,
unittests/array-view-selftests.c,
unittests/child-path-selftests.c, unittests/cli-utils-selftests.c,
unittests/common-utils-selftests.c,
unittests/copy_bitwise-selftests.c, unittests/environ-selftests.c,
unittests/format_pieces-selftests.c,
unittests/function-view-selftests.c,
unittests/lookup_name_info-selftests.c,
unittests/memory-map-selftests.c, unittests/memrange-selftests.c,
unittests/mkdir-recursive-selftests.c,
unittests/observable-selftests.c,
unittests/offset-type-selftests.c, unittests/optional-selftests.c,
unittests/parse-connection-spec-selftests.c,
unittests/ptid-selftests.c, unittests/rsp-low-selftests.c,
unittests/scoped_fd-selftests.c,
unittests/scoped_mmap-selftests.c,
unittests/scoped_restore-selftests.c,
unittests/string_view-selftests.c, unittests/style-selftests.c,
unittests/tracepoint-selftests.c, unittests/unpack-selftests.c,
unittests/utils-selftests.c, unittests/xml-utils-selftests.c,
utils.c, utils.h, valarith.c, valops.c, valprint.c, value.c,
value.h, varobj.c, varobj.h, windows-nat.c, x86-linux-nat.c,
xml-support.c, xml-support.h, xml-tdesc.h, xstormy16-tdep.c,
xtensa-linux-nat.c, dwarf2read.h: Change common to gdbsupport.
gdb/gdbserver/ChangeLog
2019-07-09 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
* configure.ac: Change common to gdbsupport.
* acinclude.m4: Change common to gdbsupport.
* Makefile.in (SFILES, OBS, GDBREPLAY_OBS, IPA_OBJS)
(version-generated.c, gdbsupport/%-ipa.o, gdbsupport/%.o): Change
common to gdbsupport.
* ax.c, event-loop.c, fork-child.c, gdb_proc_service.h,
gdbreplay.c, gdbthread.h, hostio-errno.c, hostio.c, i387-fp.c,
inferiors.c, inferiors.h, linux-aarch64-tdesc-selftest.c,
linux-amd64-ipa.c, linux-i386-ipa.c, linux-low.c,
linux-tic6x-low.c, linux-x86-low.c, linux-x86-tdesc-selftest.c,
linux-x86-tdesc.c, lynx-i386-low.c, lynx-low.c, mem-break.h,
nto-x86-low.c, regcache.c, regcache.h, remote-utils.c, server.c,
server.h, spu-low.c, symbol.c, target.h, tdesc.c, tdesc.h,
thread-db.c, tracepoint.c, win32-i386-low.c, win32-low.c: Change
common to gdbsupport.
2019-05-06 10:29:24 +08:00
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#include "gdbsupport/byte-vector.h"
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2018-09-15 01:28:45 +08:00
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2020-11-09 21:55:39 +08:00
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <unistd.h>
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2018-02-10 07:44:59 +08:00
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/* Path utilities. */
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/* Return the real path of FILENAME, expanding all the symbolic links.
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Contrary to "gdb_abspath", this function does not use
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CURRENT_DIRECTORY for path expansion. Instead, it relies on the
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current working directory (CWD) of GDB or gdbserver. */
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extern gdb::unique_xmalloc_ptr<char> gdb_realpath (const char *filename);
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/* Return a copy of FILENAME, with its directory prefix canonicalized
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by gdb_realpath. */
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extern gdb::unique_xmalloc_ptr<char>
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gdb_realpath_keepfile (const char *filename);
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/* Return PATH in absolute form, performing tilde-expansion if necessary.
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PATH cannot be NULL or the empty string.
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This does not resolve symlinks however, use gdb_realpath for that.
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Contrary to "gdb_realpath", this function uses CURRENT_DIRECTORY
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for the path expansion. This may lead to scenarios the current
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Guard against 'current_directory == NULL' on gdb_abspath (PR gdb/23613)
Ref.: https://bugzilla.redhat.com/show_bug.cgi?id=1728147
Ref.: https://sourceware.org/bugzilla/show_bug.cgi?id=23613
Hi,
This bug has been reported against Fedora GDB, but there's also an
upstream bug. The problem reported is that GDB segfaults when the
working directory is deleted. It's pretty use to reproduce it:
mkdir bla
cd bla
rmdir ../bla
gdb echo
Debugging the problem is a bit tricky, because, since the current
directory doesn't exist anymore, a corefile cannot be saved there.
After a few attempts, I came up with the following:
gdb -ex 'shell mkdir bla' -ex 'cd bla' -ex 'shell rmdir ../bla' -ex 'r echo' ./gdb/gdb
This assumes that you're inside a build directory which contains
./gdb/gdb, of course.
After investigating it, I found that the problem happens at
gdb_abspath, where we're dereferencing 'current_directory' without
checking if it's NULL:
...
(concat (current_directory,
IS_DIR_SEPARATOR (current_directory[strlen (current_directory) - 1])
? "" : SLASH_STRING,
...
So I fixed the problem with the patch below. The idea is that, if
'current_directory' is NULL, then the final string returned should be
just the "path".
After fixing the bug, I found a similar one reported against our
bugzilla: PR gdb/23613. The problem is the same, but the reproducer
is a bit different.
I really tried writing a testcase for this, but unfortunately it's
apparently not possible to start GDB inside a non-existent directory
with DejaGNU.
I regression tested this patch on the BuildBot, and no regressions
were found.
gdb/ChangeLog:
2019-12-14 Sergio Durigan Junior <sergiodj@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1728147
PR gdb/23613
* bsd-kvm.c (bsd_kvm_target_open): Use 'gdb_abspath'.
* corelow.c: Include 'gdbsupport/pathstuff.h'.
(core_target_open): Use 'gdb_abspath'.
* gdbsupport/pathstuff.c (gdb_abspath): Guard against
'current_directory == NULL' case.
* gdbsupport/pathstuff.h (gdb_abspath): Expand comment and
explain what happens when 'current_directory' is NULL.
* go32-nat.c (go32_nat_target::wait): Check if
'current_directory' is NULL before call to 'chdir'.
* source.c (add_path): Use 'gdb_abspath'.
* top.c: Include 'gdbsupport/pathstuff.h'.
(init_history): Use 'gdb_abspath'.
(set_history_filename): Likewise.
* tracefile-tfile.c: Include 'gdbsupport/pathstuff.h'.
(tfile_target_open): Use 'gdb_abspath'.
Change-Id: Ibb0932fa25bc5c2d3ae4a7f64bd7f32885ca403b
2019-07-11 04:18:27 +08:00
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working directory (CWD) is different than CURRENT_DIRECTORY.
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If CURRENT_DIRECTORY is NULL, this function returns a copy of
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PATH. */
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2018-02-10 07:44:59 +08:00
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extern gdb::unique_xmalloc_ptr<char> gdb_abspath (const char *path);
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2019-02-13 05:56:16 +08:00
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/* If the path in CHILD is a child of the path in PARENT, return a
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pointer to the first component in the CHILD's pathname below the
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PARENT. Otherwise, return NULL. */
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extern const char *child_path (const char *parent, const char *child);
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Make gdbserver work with filename-only binaries
Simon mentioned on IRC that, after the startup-with-shell feature has
been implemented on gdbserver, it is not possible to specify a
filename-only binary, like:
$ gdbserver :1234 a.out
/bin/bash: line 0: exec: a.out: not found
During startup program exited with code 127.
Exiting
This happens on systems where the current directory "." is not listed
in the PATH environment variable. Although including "." in the PATH
variable is a possible workaround, this can be considered a regression
because before startup-with-shell it was possible to use only the
filename (due to reason that gdbserver used "exec*" directly).
The idea of the patch is to verify if the program path provided by the
user (or by the remote protocol) contains a directory separator
character. If it doesn't, it means we're dealing with a filename-only
binary, so we call "gdb_abspath" to properly expand it and transform
it into a full path. Otherwise, we leave the program path untouched.
This mimicks the behaviour seen on GDB (look at "openp" and
"attach_inferior", for example).
I am also submitting a testcase which exercises the scenario described
above. This test requires gdbserver to be executed in a different CWD
than the original, so I also created a helper function, "with_cwd" (on
testsuite/lib/gdb.exp), which takes care of cd'ing into and out of the
specified dir.
Built and regtested on BuildBot, without regressions.
gdb/ChangeLog:
2018-02-28 Sergio Durigan Junior <sergiodj@redhat.com>
Simon Marchi <simon.marchi@polymtl.ca>
* common/common-utils.c: Include "sys/stat.h".
(is_regular_file): Move here from "source.c"; change return
type to "bool".
* common/common-utils.h (is_regular_file): New prototype.
* common/pathstuff.c (contains_dir_separator): New function.
* common/pathstuff.h (contains_dir_separator): New prototype.
* source.c: Don't include "sys/stat.h".
(is_regular_file): Move to "common/common-utils.c".
gdb/gdbserver/ChangeLog:
2018-02-28 Sergio Durigan Junior <sergiodj@redhat.com>
* server.c: Include "filenames.h" and "pathstuff.h".
(program_name): Delete variable.
(program_path): New anonymous class.
(get_exec_wrapper): Use "program_path" instead of
"program_name".
(handle_v_run): Likewise.
(captured_main): Likewise.
(process_serial_event): Likewise.
gdb/testsuite/ChangeLog:
2018-02-28 Sergio Durigan Junior <sergiodj@redhat.com>
* gdb.server/abspath.exp: New file.
* lib/gdb.exp (with_cwd): New procedure.
2018-02-10 07:54:41 +08:00
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/* Return whether PATH contains a directory separator character. */
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extern bool contains_dir_separator (const char *path);
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Add DWARF index cache
New in v3:
- Remove things related to the dwarf-5 format.
- Fix compilation on mingw (scoped_mmap.c).
GDB can generate indexes for DWARF debug information, which, when
integrated in the original binary, can speed up loading object files.
This can be done using the gdb-add-index script or directly by the
linker itself. However, not many people know about this. And even
among those who do, because it requires additional steps, I don't know a
lot of people who actually go through that trouble.
To help make using the DWARF index more transparent, this patch
introduces a DWARF index cache. When enabled, loading an index-less
binary in GDB will automatically save an index file in ~/.cache/gdb.
When loading that same object file again, the index file will be looked
up and used to load the DWARF index. You therefore get the benefit of
the DWARF index without having to do additional manual steps or
modifying your build system. When an index section is already present
in the file, GDB will prefer that one over looking up the cache.
When doing my edit-compile-debug cycle, I often debug multiple times the
same build, so the cache helps reducing the load time of the debug
sessions after the first one.
- The saved index file is exactly the same as the output of the "save
gdb-index" command. It is therefore the exact same content that would
be found in the .gdb_index or .debug_names section. We just leave it
as a standalone file instead of merging it in the binary.
- The cache is just a directory with files named after the object
file's build-id. It is not possible to save/load the index for an
object file without build-id in the cache.
- The cache uses the gdb index format. The problem with the dwarf-5
format is that we can generate an addendum to the .debug_str section
that you're supposed to integrate to the original binary. This
complicates a little bit loading the data from the cached index files,
so I would leave this for later.
- The size taken up by ~/.cache/gdb is not limited. I was thinking we
could add configurable limit (like ccache does), but that would come
after. Also, maybe a command to flush the cache.
- The cache is disabled by default. I think once it's been out there
and tested for a while, it could be turned on by default, so that
everybody can enjoy it.
- The code was made to follow the XDG specification: if the
XDG_CACHE_HOME environment variable, it is used, otherwise it falls
back to ~/.cache/gdb. It is possible to change it using "set
index-cache directory". On other OSes than GNU/Linux, ~/.cache may
not be the best place to put such data. On macOS it should probably
default to ~/Library/Caches/... On Windows, %LocalAppData%/... I
don't intend to do this part, but further patches are welcome.
- I think that we need to be careful that multiple instances of GDB
don't interfere with each other (not far fetched at all if you run GDB
in some automated script) and the cache is always coherent (either the
file is not found, or it is found and entirely valid). Writing the
file directly to its final location seems like a recipe for failure.
One GDB could read a file in the index while it is being written by
another GDB. To mitigate this, I made write_psymtabs_to_index write
to temporary files and rename them once it's done. Two GDB instances
writing the index for the same file should not step on each other's
toes (the last file to be renamed will stay). A GDB looking up a file
will only see a complete file or no file. Also, if GDB crashes while
generating the index file, it will leave a work-in-progress file, but
it won't be picked up by other instances looking up in the cache.
gdb/ChangeLog:
* common/pathstuff.h (get_standard_cache_dir): New.
* common/pathstuff.c (get_standard_cache_dir): New.
* build-id.h (build_id_to_string): New.
* dwarf-index-common.h (INDEX4_SUFFIX, INDEX5_SUFFIX,
DEBUG_STR_SUFFIX): Move to here.
* dwarf-index-write.c (INDEX4_SUFFIX, INDEX5_SUFFIX,
DEBUG_STR_SUFFIX): Move from there.
(write_psymtabs_to_index): Make non-static, add basename
parameter. Write to temporary files, rename when done.
(save_gdb_index_command): Adjust call to
write_psymtabs_to_index.
* dwarf2read.h (dwarf2_per_objfile) <index_cache_res>: New
field.
* dwarf2read.c (dwz_file) <index_cache_res>: New field.
(get_gdb_index_contents_from_cache): New.
(get_gdb_index_contents_from_cache_dwz): New.
(dwarf2_initialize_objfile): Read index from cache.
(dwarf2_build_psymtabs): Save to index.
* dwarf-index-cache.h: New file.
* dwarf-index-cache.c: New file.
* dwarf-index-write.h: New file.
gdb/testsuite/ChangeLog:
* boards/index-cache-gdb.exp: New file.
* gdb.dwarf2/index-cache.exp: New file.
* gdb.dwarf2/index-cache.c: New file.
* gdb.base/maint.exp: Check if we are using the index cache.
2018-08-08 06:14:20 +08:00
|
|
|
/* Get the usual user cache directory for the current platform.
|
|
|
|
|
|
|
|
On Linux, it follows the XDG Base Directory specification: use
|
2018-09-14 22:48:22 +08:00
|
|
|
$XDG_CACHE_HOME/gdb if the XDG_CACHE_HOME environment variable is
|
|
|
|
defined, otherwise $HOME/.cache.
|
Add DWARF index cache
New in v3:
- Remove things related to the dwarf-5 format.
- Fix compilation on mingw (scoped_mmap.c).
GDB can generate indexes for DWARF debug information, which, when
integrated in the original binary, can speed up loading object files.
This can be done using the gdb-add-index script or directly by the
linker itself. However, not many people know about this. And even
among those who do, because it requires additional steps, I don't know a
lot of people who actually go through that trouble.
To help make using the DWARF index more transparent, this patch
introduces a DWARF index cache. When enabled, loading an index-less
binary in GDB will automatically save an index file in ~/.cache/gdb.
When loading that same object file again, the index file will be looked
up and used to load the DWARF index. You therefore get the benefit of
the DWARF index without having to do additional manual steps or
modifying your build system. When an index section is already present
in the file, GDB will prefer that one over looking up the cache.
When doing my edit-compile-debug cycle, I often debug multiple times the
same build, so the cache helps reducing the load time of the debug
sessions after the first one.
- The saved index file is exactly the same as the output of the "save
gdb-index" command. It is therefore the exact same content that would
be found in the .gdb_index or .debug_names section. We just leave it
as a standalone file instead of merging it in the binary.
- The cache is just a directory with files named after the object
file's build-id. It is not possible to save/load the index for an
object file without build-id in the cache.
- The cache uses the gdb index format. The problem with the dwarf-5
format is that we can generate an addendum to the .debug_str section
that you're supposed to integrate to the original binary. This
complicates a little bit loading the data from the cached index files,
so I would leave this for later.
- The size taken up by ~/.cache/gdb is not limited. I was thinking we
could add configurable limit (like ccache does), but that would come
after. Also, maybe a command to flush the cache.
- The cache is disabled by default. I think once it's been out there
and tested for a while, it could be turned on by default, so that
everybody can enjoy it.
- The code was made to follow the XDG specification: if the
XDG_CACHE_HOME environment variable, it is used, otherwise it falls
back to ~/.cache/gdb. It is possible to change it using "set
index-cache directory". On other OSes than GNU/Linux, ~/.cache may
not be the best place to put such data. On macOS it should probably
default to ~/Library/Caches/... On Windows, %LocalAppData%/... I
don't intend to do this part, but further patches are welcome.
- I think that we need to be careful that multiple instances of GDB
don't interfere with each other (not far fetched at all if you run GDB
in some automated script) and the cache is always coherent (either the
file is not found, or it is found and entirely valid). Writing the
file directly to its final location seems like a recipe for failure.
One GDB could read a file in the index while it is being written by
another GDB. To mitigate this, I made write_psymtabs_to_index write
to temporary files and rename them once it's done. Two GDB instances
writing the index for the same file should not step on each other's
toes (the last file to be renamed will stay). A GDB looking up a file
will only see a complete file or no file. Also, if GDB crashes while
generating the index file, it will leave a work-in-progress file, but
it won't be picked up by other instances looking up in the cache.
gdb/ChangeLog:
* common/pathstuff.h (get_standard_cache_dir): New.
* common/pathstuff.c (get_standard_cache_dir): New.
* build-id.h (build_id_to_string): New.
* dwarf-index-common.h (INDEX4_SUFFIX, INDEX5_SUFFIX,
DEBUG_STR_SUFFIX): Move to here.
* dwarf-index-write.c (INDEX4_SUFFIX, INDEX5_SUFFIX,
DEBUG_STR_SUFFIX): Move from there.
(write_psymtabs_to_index): Make non-static, add basename
parameter. Write to temporary files, rename when done.
(save_gdb_index_command): Adjust call to
write_psymtabs_to_index.
* dwarf2read.h (dwarf2_per_objfile) <index_cache_res>: New
field.
* dwarf2read.c (dwz_file) <index_cache_res>: New field.
(get_gdb_index_contents_from_cache): New.
(get_gdb_index_contents_from_cache_dwz): New.
(dwarf2_initialize_objfile): Read index from cache.
(dwarf2_build_psymtabs): Save to index.
* dwarf-index-cache.h: New file.
* dwarf-index-cache.c: New file.
* dwarf-index-write.h: New file.
gdb/testsuite/ChangeLog:
* boards/index-cache-gdb.exp: New file.
* gdb.dwarf2/index-cache.exp: New file.
* gdb.dwarf2/index-cache.c: New file.
* gdb.base/maint.exp: Check if we are using the index cache.
2018-08-08 06:14:20 +08:00
|
|
|
|
2018-09-14 22:48:22 +08:00
|
|
|
On macOS, it follows the local convention and uses
|
|
|
|
~/Library/Caches/gdb.
|
|
|
|
|
|
|
|
The return value is absolute and tilde-expanded. Return an empty
|
|
|
|
string if neither XDG_CACHE_HOME (on Linux) or HOME are defined. */
|
Add DWARF index cache
New in v3:
- Remove things related to the dwarf-5 format.
- Fix compilation on mingw (scoped_mmap.c).
GDB can generate indexes for DWARF debug information, which, when
integrated in the original binary, can speed up loading object files.
This can be done using the gdb-add-index script or directly by the
linker itself. However, not many people know about this. And even
among those who do, because it requires additional steps, I don't know a
lot of people who actually go through that trouble.
To help make using the DWARF index more transparent, this patch
introduces a DWARF index cache. When enabled, loading an index-less
binary in GDB will automatically save an index file in ~/.cache/gdb.
When loading that same object file again, the index file will be looked
up and used to load the DWARF index. You therefore get the benefit of
the DWARF index without having to do additional manual steps or
modifying your build system. When an index section is already present
in the file, GDB will prefer that one over looking up the cache.
When doing my edit-compile-debug cycle, I often debug multiple times the
same build, so the cache helps reducing the load time of the debug
sessions after the first one.
- The saved index file is exactly the same as the output of the "save
gdb-index" command. It is therefore the exact same content that would
be found in the .gdb_index or .debug_names section. We just leave it
as a standalone file instead of merging it in the binary.
- The cache is just a directory with files named after the object
file's build-id. It is not possible to save/load the index for an
object file without build-id in the cache.
- The cache uses the gdb index format. The problem with the dwarf-5
format is that we can generate an addendum to the .debug_str section
that you're supposed to integrate to the original binary. This
complicates a little bit loading the data from the cached index files,
so I would leave this for later.
- The size taken up by ~/.cache/gdb is not limited. I was thinking we
could add configurable limit (like ccache does), but that would come
after. Also, maybe a command to flush the cache.
- The cache is disabled by default. I think once it's been out there
and tested for a while, it could be turned on by default, so that
everybody can enjoy it.
- The code was made to follow the XDG specification: if the
XDG_CACHE_HOME environment variable, it is used, otherwise it falls
back to ~/.cache/gdb. It is possible to change it using "set
index-cache directory". On other OSes than GNU/Linux, ~/.cache may
not be the best place to put such data. On macOS it should probably
default to ~/Library/Caches/... On Windows, %LocalAppData%/... I
don't intend to do this part, but further patches are welcome.
- I think that we need to be careful that multiple instances of GDB
don't interfere with each other (not far fetched at all if you run GDB
in some automated script) and the cache is always coherent (either the
file is not found, or it is found and entirely valid). Writing the
file directly to its final location seems like a recipe for failure.
One GDB could read a file in the index while it is being written by
another GDB. To mitigate this, I made write_psymtabs_to_index write
to temporary files and rename them once it's done. Two GDB instances
writing the index for the same file should not step on each other's
toes (the last file to be renamed will stay). A GDB looking up a file
will only see a complete file or no file. Also, if GDB crashes while
generating the index file, it will leave a work-in-progress file, but
it won't be picked up by other instances looking up in the cache.
gdb/ChangeLog:
* common/pathstuff.h (get_standard_cache_dir): New.
* common/pathstuff.c (get_standard_cache_dir): New.
* build-id.h (build_id_to_string): New.
* dwarf-index-common.h (INDEX4_SUFFIX, INDEX5_SUFFIX,
DEBUG_STR_SUFFIX): Move to here.
* dwarf-index-write.c (INDEX4_SUFFIX, INDEX5_SUFFIX,
DEBUG_STR_SUFFIX): Move from there.
(write_psymtabs_to_index): Make non-static, add basename
parameter. Write to temporary files, rename when done.
(save_gdb_index_command): Adjust call to
write_psymtabs_to_index.
* dwarf2read.h (dwarf2_per_objfile) <index_cache_res>: New
field.
* dwarf2read.c (dwz_file) <index_cache_res>: New field.
(get_gdb_index_contents_from_cache): New.
(get_gdb_index_contents_from_cache_dwz): New.
(dwarf2_initialize_objfile): Read index from cache.
(dwarf2_build_psymtabs): Save to index.
* dwarf-index-cache.h: New file.
* dwarf-index-cache.c: New file.
* dwarf-index-write.h: New file.
gdb/testsuite/ChangeLog:
* boards/index-cache-gdb.exp: New file.
* gdb.dwarf2/index-cache.exp: New file.
* gdb.dwarf2/index-cache.c: New file.
* gdb.base/maint.exp: Check if we are using the index cache.
2018-08-08 06:14:20 +08:00
|
|
|
|
|
|
|
extern std::string get_standard_cache_dir ();
|
|
|
|
|
Import mkdtemp gnulib module, fix mingw build
Building with mingw currently fails:
CXX unittests/mkdir-recursive-selftests.o
/home/emaisin/src/binutils-gdb/gdb/unittests/mkdir-recursive-selftests.c: In function ‘void selftests::mkdir_recursive::test()’:
/home/emaisin/src/binutils-gdb/gdb/unittests/mkdir-recursive-selftests.c:49:20: error: ‘mkdtemp’ was not declared in this scope
if (mkdtemp (base) == NULL)
^
Commit
e418a61a67a ("Move mkdir_recursive to common/filestuff.c")
moved this code, but also removed the HAVE_MKDTEMP guard which prevented
the mkdtemp call to be compiled on mingw.
We can either put back the HAVE_MKDTEMP ifdef, or import the gnulib
mkdtemp module, which provides the function for mingw. Since the
mkdir_recursive is susceptible to be used on mingw at some point, I
think it would be nice to have it tested on mingw, so I did the latter.
Once built, I tested it on Windows (copied the resulting gdb.exe on a
Windows machine, ran it, and ran "maint selftest mkdir_recursive"). It
failed, because the temporary directory is hardcoded to "/tmp/...". I
therefore added and used a new get_standard_temp_dir function, which
returns an appropriate temporary directory for the host platform.
gdb/ChangeLog:
* common/pathstuff.c (get_standard_temp_dir): New.
* common/pathstuff.h (get_standard_temp_dir): New.
* config.in: Re-generate.
* configure: Re-generate.
* configure.ac: Don't check for mkdtemp.
* gnulib/aclocal-m4-deps.mk: Re-generate.
* gnulib/aclocal.m4: Re-generate.
* gnulib/config.in: Re-generate.
* gnulib/configure: Re-generate.
* gnulib/import/Makefile.am: Re-generate.
* gnulib/import/Makefile.in: Re-generate.
* gnulib/import/m4/gnulib-cache.m4: Re-generate.
* gnulib/import/m4/gnulib-comp.m4: Re-generate.
* gnulib/import/m4/mkdtemp.m4: New file.
* gnulib/import/mkdtemp.c: New file.
* gnulib/update-gnulib.sh (IMPORTED_GNULIB_MODULES):
Add mkdtemp module.
* unittests/mkdir-recursive-selftests.c (test): Use
get_standard_temp_dir.
(_initialize_mkdir_recursive_selftests): Remove HAVE_MKDTEMP
ifdef.
* compile/compile.c (get_compile_file_tempdir): Likewise.
2018-11-02 03:40:43 +08:00
|
|
|
/* Get the usual temporary directory for the current platform.
|
|
|
|
|
|
|
|
On Windows, this is the TMP or TEMP environment variable.
|
|
|
|
|
|
|
|
On the rest, this is the TMPDIR environment variable, if defined, else /tmp.
|
|
|
|
|
|
|
|
Throw an exception on error. */
|
|
|
|
|
|
|
|
extern std::string get_standard_temp_dir ();
|
|
|
|
|
2020-07-06 03:02:40 +08:00
|
|
|
/* Get the usual user config directory for the current platform.
|
|
|
|
|
|
|
|
On Linux, it follows the XDG Base Directory specification: use
|
|
|
|
$XDG_CONFIG_HOME/gdb if the XDG_CONFIG_HOME environment variable is
|
|
|
|
defined, otherwise $HOME/.config.
|
|
|
|
|
|
|
|
On macOS, it follows the local convention and uses
|
|
|
|
~/Library/Preferences/gdb.
|
|
|
|
|
|
|
|
The return value is absolute and tilde-expanded. Return an empty
|
|
|
|
string if neither XDG_CONFIG_HOME (on Linux) or HOME are defined. */
|
|
|
|
|
|
|
|
extern std::string get_standard_config_dir ();
|
|
|
|
|
2020-09-25 21:50:56 +08:00
|
|
|
/* Look for FILENAME in the standard configuration directory as returned by
|
|
|
|
GET_STANDARD_CONFIG_DIR and return the path to the file. No check is
|
|
|
|
performed that the file actually exists or not.
|
|
|
|
|
|
|
|
If FILENAME begins with a '.' then the path returned will remove the
|
|
|
|
leading '.' character, for example passing '.gdbinit' could return the
|
|
|
|
path '/home/username/.config/gdb/gdbinit'. */
|
|
|
|
|
|
|
|
extern std::string get_standard_config_filename (const char *filename);
|
|
|
|
|
|
|
|
/* Look for a file called NAME in either the standard config directory or
|
|
|
|
in the users home directory. If a suitable file is found then *BUF will
|
|
|
|
be filled with the contents of a call to 'stat' on the found file,
|
|
|
|
otherwise *BUF is undefined after this call.
|
|
|
|
|
|
|
|
If NAME starts with a '.' character then, when looking in the standard
|
|
|
|
config directory the file searched for has the '.' removed. For
|
|
|
|
example, if NAME is '.gdbinit' then on a Linux target GDB might look for
|
|
|
|
'~/.config/gdb/gdbinit' and then '~/.gdbinit'. */
|
|
|
|
|
|
|
|
extern std::string find_gdb_home_config_file (const char *name,
|
|
|
|
struct stat *buf);
|
|
|
|
|
2018-09-15 00:35:45 +08:00
|
|
|
/* Return the file name of the user's shell. Normally this comes from
|
|
|
|
the SHELL environment variable. */
|
|
|
|
|
|
|
|
extern const char *get_shell ();
|
|
|
|
|
2018-09-15 01:28:45 +08:00
|
|
|
/* Make a filename suitable to pass to mkstemp based on F (e.g.
|
|
|
|
/tmp/foo -> /tmp/foo-XXXXXX). */
|
|
|
|
|
|
|
|
extern gdb::char_vector make_temp_filename (const std::string &f);
|
|
|
|
|
2019-01-28 03:51:36 +08:00
|
|
|
#endif /* COMMON_PATHSTUFF_H */
|