binutils-gdb/gdb/common/pathstuff.c

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Create new common/pathstuff.[ch] This commit moves the path manipulation routines found on utils.c to a new common/pathstuff.c, and updates the Makefile.in's accordingly. The routines moved are "gdb_realpath", "gdb_realpath_keepfile" and "gdb_abspath". This will be needed because gdbserver will have to call "gdb_abspath" on my next patch, which implements a way to expand the path of the inferior provided by the user in order to allow specifying just the binary name when starting gdbserver, like: $ gdbserver :1234 a.out With the recent addition of the startup-with-shell feature on gdbserver, this scenario doesn't work anymore if the user doesn't have the current directory listed in the PATH variable. I had to do a minor adjustment on "gdb_abspath" because we don't have access to "tilde_expand" on gdbserver, so now the function is using "gdb_tilde_expand" instead. Otherwise, the code is the same. Regression tested on the BuildBot, without regressions. gdb/ChangeLog: 2018-02-28 Sergio Durigan Junior <sergiodj@redhat.com> * Makefile.in (COMMON_SFILES): Add "common/pathstuff.c". (HFILES_NO_SRCDIR): Add "common/pathstuff.h". * auto-load.c: Include "common/pathstuff.h". * common/common-def.h (current_directory): Move here. * common/gdb_tilde_expand.c (gdb_tilde_expand_up): New function. * common/gdb_tilde_expand.h (gdb_tilde_expand_up): New prototype. * common/pathstuff.c: New file. * common/pathstuff.h: New file. * compile/compile.c: Include "common/pathstuff.h". * defs.h (current_directory): Move to "common/common-defs.h". * dwarf2read.c: Include "common/pathstuff.h". * exec.c: Likewise. * guile/scm-safe-call.c: Likewise. * linux-thread-db.c: Likewise. * main.c: Likewise. * nto-tdep.c: Likewise. * objfiles.c: Likewise. * source.c: Likewise. * symtab.c: Likewise. * utils.c: Include "common/pathstuff.h". (gdb_realpath): Move to "common/pathstuff.c". (gdb_realpath_keepfile): Likewise. (gdb_abspath): Likewise. * utils.h (gdb_realpath): Move to "common/pathstuff.h". (gdb_realpath_keepfile): Likewise. (gdb_abspath): Likewise. gdb/gdbserver/ChangeLog: 2018-02-28 Sergio Durigan Junior <sergiodj@redhat.com> * Makefile.in (SFILES): Add "$(srcdir)/common/pathstuff.c". (OBJS): Add "pathstuff.o". * server.c (current_directory): New global variable. (captured_main): Initialize "current_directory".
2018-02-10 07:44:59 +08:00
/* Path manipulation routines for GDB and gdbserver.
Copyright (C) 1986-2018 Free Software Foundation, Inc.
This file is part of GDB.
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/>. */
#include "common-defs.h"
#include "pathstuff.h"
#include "host-defs.h"
#include "filenames.h"
#include "gdb_tilde_expand.h"
#ifdef USE_WIN32API
#include <windows.h>
#endif
Create new common/pathstuff.[ch] This commit moves the path manipulation routines found on utils.c to a new common/pathstuff.c, and updates the Makefile.in's accordingly. The routines moved are "gdb_realpath", "gdb_realpath_keepfile" and "gdb_abspath". This will be needed because gdbserver will have to call "gdb_abspath" on my next patch, which implements a way to expand the path of the inferior provided by the user in order to allow specifying just the binary name when starting gdbserver, like: $ gdbserver :1234 a.out With the recent addition of the startup-with-shell feature on gdbserver, this scenario doesn't work anymore if the user doesn't have the current directory listed in the PATH variable. I had to do a minor adjustment on "gdb_abspath" because we don't have access to "tilde_expand" on gdbserver, so now the function is using "gdb_tilde_expand" instead. Otherwise, the code is the same. Regression tested on the BuildBot, without regressions. gdb/ChangeLog: 2018-02-28 Sergio Durigan Junior <sergiodj@redhat.com> * Makefile.in (COMMON_SFILES): Add "common/pathstuff.c". (HFILES_NO_SRCDIR): Add "common/pathstuff.h". * auto-load.c: Include "common/pathstuff.h". * common/common-def.h (current_directory): Move here. * common/gdb_tilde_expand.c (gdb_tilde_expand_up): New function. * common/gdb_tilde_expand.h (gdb_tilde_expand_up): New prototype. * common/pathstuff.c: New file. * common/pathstuff.h: New file. * compile/compile.c: Include "common/pathstuff.h". * defs.h (current_directory): Move to "common/common-defs.h". * dwarf2read.c: Include "common/pathstuff.h". * exec.c: Likewise. * guile/scm-safe-call.c: Likewise. * linux-thread-db.c: Likewise. * main.c: Likewise. * nto-tdep.c: Likewise. * objfiles.c: Likewise. * source.c: Likewise. * symtab.c: Likewise. * utils.c: Include "common/pathstuff.h". (gdb_realpath): Move to "common/pathstuff.c". (gdb_realpath_keepfile): Likewise. (gdb_abspath): Likewise. * utils.h (gdb_realpath): Move to "common/pathstuff.h". (gdb_realpath_keepfile): Likewise. (gdb_abspath): Likewise. gdb/gdbserver/ChangeLog: 2018-02-28 Sergio Durigan Junior <sergiodj@redhat.com> * Makefile.in (SFILES): Add "$(srcdir)/common/pathstuff.c". (OBJS): Add "pathstuff.o". * server.c (current_directory): New global variable. (captured_main): Initialize "current_directory".
2018-02-10 07:44:59 +08:00
/* See common/pathstuff.h. */
gdb::unique_xmalloc_ptr<char>
gdb_realpath (const char *filename)
{
/* On most hosts, we rely on canonicalize_file_name to compute
the FILENAME's realpath.
But the situation is slightly more complex on Windows, due to some
versions of GCC which were reported to generate paths where
backlashes (the directory separator) were doubled. For instance:
c:\\some\\double\\slashes\\dir
... instead of ...
c:\some\double\slashes\dir
Those double-slashes were getting in the way when comparing paths,
for instance when trying to insert a breakpoint as follow:
(gdb) b c:/some/double/slashes/dir/foo.c:4
No source file named c:/some/double/slashes/dir/foo.c:4.
(gdb) b c:\some\double\slashes\dir\foo.c:4
No source file named c:\some\double\slashes\dir\foo.c:4.
To prevent this from happening, we need this function to always
strip those extra backslashes. While canonicalize_file_name does
perform this simplification, it only works when the path is valid.
Since the simplification would be useful even if the path is not
valid (one can always set a breakpoint on a file, even if the file
does not exist locally), we rely instead on GetFullPathName to
perform the canonicalization. */
#if defined (_WIN32)
{
char buf[MAX_PATH];
DWORD len = GetFullPathName (filename, MAX_PATH, buf, NULL);
/* The file system is case-insensitive but case-preserving.
So it is important we do not lowercase the path. Otherwise,
we might not be able to display the original casing in a given
path. */
if (len > 0 && len < MAX_PATH)
return gdb::unique_xmalloc_ptr<char> (xstrdup (buf));
}
#else
{
char *rp = canonicalize_file_name (filename);
if (rp != NULL)
return gdb::unique_xmalloc_ptr<char> (rp);
}
#endif
/* This system is a lost cause, just dup the buffer. */
return gdb::unique_xmalloc_ptr<char> (xstrdup (filename));
}
/* See common/pathstuff.h. */
gdb::unique_xmalloc_ptr<char>
gdb_realpath_keepfile (const char *filename)
{
const char *base_name = lbasename (filename);
char *dir_name;
char *result;
/* Extract the basename of filename, and return immediately
a copy of filename if it does not contain any directory prefix. */
if (base_name == filename)
return gdb::unique_xmalloc_ptr<char> (xstrdup (filename));
dir_name = (char *) alloca ((size_t) (base_name - filename + 2));
/* Allocate enough space to store the dir_name + plus one extra
character sometimes needed under Windows (see below), and
then the closing \000 character. */
strncpy (dir_name, filename, base_name - filename);
dir_name[base_name - filename] = '\000';
#ifdef HAVE_DOS_BASED_FILE_SYSTEM
/* We need to be careful when filename is of the form 'd:foo', which
is equivalent of d:./foo, which is totally different from d:/foo. */
if (strlen (dir_name) == 2 && isalpha (dir_name[0]) && dir_name[1] == ':')
{
dir_name[2] = '.';
dir_name[3] = '\000';
}
#endif
/* Canonicalize the directory prefix, and build the resulting
filename. If the dirname realpath already contains an ending
directory separator, avoid doubling it. */
gdb::unique_xmalloc_ptr<char> path_storage = gdb_realpath (dir_name);
const char *real_path = path_storage.get ();
if (IS_DIR_SEPARATOR (real_path[strlen (real_path) - 1]))
result = concat (real_path, base_name, (char *) NULL);
else
result = concat (real_path, SLASH_STRING, base_name, (char *) NULL);
return gdb::unique_xmalloc_ptr<char> (result);
}
/* See common/pathstuff.h. */
gdb::unique_xmalloc_ptr<char>
gdb_abspath (const char *path)
{
gdb_assert (path != NULL && path[0] != '\0');
if (path[0] == '~')
return gdb_tilde_expand_up (path);
if (IS_ABSOLUTE_PATH (path))
return gdb::unique_xmalloc_ptr<char> (xstrdup (path));
/* Beware the // my son, the Emacs barfs, the botch that catch... */
return gdb::unique_xmalloc_ptr<char>
(concat (current_directory,
IS_DIR_SEPARATOR (current_directory[strlen (current_directory) - 1])
? "" : SLASH_STRING,
path, (char *) NULL));
}
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
/* See common/pathstuff.h. */
bool
contains_dir_separator (const char *path)
{
for (; *path != '\0'; path++)
{
if (IS_DIR_SEPARATOR (*path))
return true;
}
return false;
}
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
/* See common/pathstuff.h. */
std::string
get_standard_cache_dir ()
{
#ifdef __APPLE__
#define HOME_CACHE_DIR "Library/Caches"
#else
#define HOME_CACHE_DIR ".cache"
#endif
#ifndef __APPLE__
const char *xdg_cache_home = getenv ("XDG_CACHE_HOME");
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
if (xdg_cache_home != NULL)
{
/* Make sure the path is absolute and tilde-expanded. */
gdb::unique_xmalloc_ptr<char> abs (gdb_abspath (xdg_cache_home));
return string_printf ("%s/gdb", abs.get ());
}
#endif
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
const char *home = getenv ("HOME");
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
if (home != NULL)
{
/* Make sure the path is absolute and tilde-expanded. */
gdb::unique_xmalloc_ptr<char> abs (gdb_abspath (home));
return string_printf ("%s/" HOME_CACHE_DIR "/gdb", abs.get ());
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
}
return {};
}
/* See common/pathstuff.h. */
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
std::string
get_standard_temp_dir ()
{
#ifdef WIN32
const char *tmp = getenv ("TMP");
if (tmp != nullptr)
return tmp;
tmp = getenv ("TEMP");
if (tmp != nullptr)
return tmp;
error (_("Couldn't find temp dir path, both TMP and TEMP are unset."));
#else
const char *tmp = getenv ("TMPDIR");
if (tmp != nullptr)
return tmp;
return "/tmp";
#endif
}
/* See common/pathstuff.h. */
const char *
get_shell ()
{
const char *ret = getenv ("SHELL");
if (ret == NULL)
ret = "/bin/sh";
return ret;
}
/* See common/pathstuff.h. */
gdb::char_vector
make_temp_filename (const std::string &f)
{
gdb::char_vector filename_temp (f.length () + 8);
strcpy (filename_temp.data (), f.c_str ());
strcat (filename_temp.data () + f.size (), "-XXXXXX");
return filename_temp;
}