binutils-gdb/gdb/dwarf2/index-cache.c
Tom Tromey 6cb06a8cda Unify gdb printf functions
Now that filtered and unfiltered output can be treated identically, we
can unify the printf family of functions.  This is done under the name
"gdb_printf".  Most of this patch was written by script.
2022-03-29 12:46:24 -06:00

403 lines
11 KiB
C

/* Caching of GDB/DWARF index files.
Copyright (C) 1994-2022 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 "defs.h"
#include "dwarf2/index-cache.h"
#include "build-id.h"
#include "cli/cli-cmds.h"
#include "cli/cli-decode.h"
#include "command.h"
#include "gdbsupport/scoped_mmap.h"
#include "gdbsupport/pathstuff.h"
#include "dwarf2/index-write.h"
#include "dwarf2/read.h"
#include "dwarf2/dwz.h"
#include "objfiles.h"
#include "gdbsupport/selftest.h"
#include <string>
#include <stdlib.h>
/* When set to true, show debug messages about the index cache. */
static bool debug_index_cache = false;
#define index_cache_debug(FMT, ...) \
debug_prefixed_printf_cond_nofunc (debug_index_cache, "index-cache", \
FMT, ## __VA_ARGS__)
/* The index cache directory, used for "set/show index-cache directory". */
static std::string index_cache_directory;
/* See dwarf-index.cache.h. */
index_cache global_index_cache;
/* set/show index-cache commands. */
static cmd_list_element *set_index_cache_prefix_list;
static cmd_list_element *show_index_cache_prefix_list;
/* Default destructor of index_cache_resource. */
index_cache_resource::~index_cache_resource () = default;
/* See dwarf-index-cache.h. */
void
index_cache::set_directory (std::string dir)
{
gdb_assert (!dir.empty ());
m_dir = std::move (dir);
index_cache_debug ("now using directory %s", m_dir.c_str ());
}
/* See dwarf-index-cache.h. */
void
index_cache::enable ()
{
index_cache_debug ("enabling (%s)", m_dir.c_str ());
m_enabled = true;
}
/* See dwarf-index-cache.h. */
void
index_cache::disable ()
{
index_cache_debug ("disabling");
m_enabled = false;
}
/* See dwarf-index-cache.h. */
void
index_cache::store (dwarf2_per_objfile *per_objfile)
{
objfile *obj = per_objfile->objfile;
if (!enabled ())
return;
/* Get build id of objfile. */
const bfd_build_id *build_id = build_id_bfd_get (obj->obfd);
if (build_id == nullptr)
{
index_cache_debug ("objfile %s has no build id",
objfile_name (obj));
return;
}
std::string build_id_str = build_id_to_string (build_id);
/* Get build id of dwz file, if present. */
gdb::optional<std::string> dwz_build_id_str;
const dwz_file *dwz = dwarf2_get_dwz_file (per_objfile->per_bfd);
const char *dwz_build_id_ptr = NULL;
if (dwz != nullptr)
{
const bfd_build_id *dwz_build_id = build_id_bfd_get (dwz->dwz_bfd.get ());
if (dwz_build_id == nullptr)
{
index_cache_debug ("dwz objfile %s has no build id",
dwz->filename ());
return;
}
dwz_build_id_str = build_id_to_string (dwz_build_id);
dwz_build_id_ptr = dwz_build_id_str->c_str ();
}
if (m_dir.empty ())
{
warning (_("The index cache directory name is empty, skipping store."));
return;
}
try
{
/* Try to create the containing directory. */
if (!mkdir_recursive (m_dir.c_str ()))
{
warning (_("index cache: could not make cache directory: %s"),
safe_strerror (errno));
return;
}
index_cache_debug ("writing index cache for objfile %s",
objfile_name (obj));
/* Write the index itself to the directory, using the build id as the
filename. */
write_psymtabs_to_index (per_objfile, m_dir.c_str (),
build_id_str.c_str (), dwz_build_id_ptr,
dw_index_kind::GDB_INDEX);
}
catch (const gdb_exception_error &except)
{
index_cache_debug ("couldn't store index cache for objfile %s: %s",
objfile_name (obj), except.what ());
}
}
#if HAVE_SYS_MMAN_H
/* Hold the resources for an mmapped index file. */
struct index_cache_resource_mmap final : public index_cache_resource
{
/* Try to mmap FILENAME. Throw an exception on failure, including if the
file doesn't exist. */
index_cache_resource_mmap (const char *filename)
: mapping (mmap_file (filename))
{}
scoped_mmap mapping;
};
/* See dwarf-index-cache.h. */
gdb::array_view<const gdb_byte>
index_cache::lookup_gdb_index (const bfd_build_id *build_id,
std::unique_ptr<index_cache_resource> *resource)
{
if (!enabled ())
return {};
if (m_dir.empty ())
{
warning (_("The index cache directory name is empty, skipping cache "
"lookup."));
return {};
}
/* Compute where we would expect a gdb index file for this build id to be. */
std::string filename = make_index_filename (build_id, INDEX4_SUFFIX);
try
{
index_cache_debug ("trying to read %s",
filename.c_str ());
/* Try to map that file. */
index_cache_resource_mmap *mmap_resource
= new index_cache_resource_mmap (filename.c_str ());
/* Yay, it worked! Hand the resource to the caller. */
resource->reset (mmap_resource);
return gdb::array_view<const gdb_byte>
((const gdb_byte *) mmap_resource->mapping.get (),
mmap_resource->mapping.size ());
}
catch (const gdb_exception_error &except)
{
index_cache_debug ("couldn't read %s: %s",
filename.c_str (), except.what ());
}
return {};
}
#else /* !HAVE_SYS_MMAN_H */
/* See dwarf-index-cache.h. This is a no-op on unsupported systems. */
gdb::array_view<const gdb_byte>
index_cache::lookup_gdb_index (const bfd_build_id *build_id,
std::unique_ptr<index_cache_resource> *resource)
{
return {};
}
#endif
/* See dwarf-index-cache.h. */
std::string
index_cache::make_index_filename (const bfd_build_id *build_id,
const char *suffix) const
{
std::string build_id_str = build_id_to_string (build_id);
return m_dir + SLASH_STRING + build_id_str + suffix;
}
/* True when we are executing "show index-cache". This is used to improve the
printout a little bit. */
static bool in_show_index_cache_command = false;
/* "show index-cache" handler. */
static void
show_index_cache_command (const char *arg, int from_tty)
{
/* Note that we are executing "show index-cache". */
auto restore_flag = make_scoped_restore (&in_show_index_cache_command, true);
/* Call all "show index-cache" subcommands. */
cmd_show_list (show_index_cache_prefix_list, from_tty);
gdb_printf ("\n");
gdb_printf
(_("The index cache is currently %s.\n"),
global_index_cache.enabled () ? _("enabled") : _("disabled"));
}
/* "set/show index-cache enabled" set callback. */
static void
set_index_cache_enabled_command (bool value)
{
if (value)
global_index_cache.enable ();
else
global_index_cache.disable ();
}
/* "set/show index-cache enabled" get callback. */
static bool
get_index_cache_enabled_command ()
{
return global_index_cache.enabled ();
}
/* "set/show index-cache enabled" show callback. */
static void
show_index_cache_enabled_command (ui_file *stream, int from_tty,
cmd_list_element *cmd, const char *value)
{
gdb_printf (stream, _("The index cache is %s.\n"), value);
}
/* "set index-cache directory" handler. */
static void
set_index_cache_directory_command (const char *arg, int from_tty,
cmd_list_element *element)
{
/* Make sure the index cache directory is absolute and tilde-expanded. */
gdb::unique_xmalloc_ptr<char> abs
= gdb_abspath (index_cache_directory.c_str ());
index_cache_directory = abs.get ();
global_index_cache.set_directory (index_cache_directory);
}
/* "show index-cache stats" handler. */
static void
show_index_cache_stats_command (const char *arg, int from_tty)
{
const char *indent = "";
/* If this command is invoked through "show index-cache", make the display a
bit nicer. */
if (in_show_index_cache_command)
{
indent = " ";
gdb_printf ("\n");
}
gdb_printf (_("%s Cache hits (this session): %u\n"),
indent, global_index_cache.n_hits ());
gdb_printf (_("%sCache misses (this session): %u\n"),
indent, global_index_cache.n_misses ());
}
void _initialize_index_cache ();
void
_initialize_index_cache ()
{
/* Set the default index cache directory. */
std::string cache_dir = get_standard_cache_dir ();
if (!cache_dir.empty ())
{
index_cache_directory = cache_dir;
global_index_cache.set_directory (std::move (cache_dir));
}
else
warning (_("Couldn't determine a path for the index cache directory."));
/* set index-cache */
add_basic_prefix_cmd ("index-cache", class_files,
_("Set index-cache options."),
&set_index_cache_prefix_list,
false, &setlist);
/* show index-cache */
add_prefix_cmd ("index-cache", class_files, show_index_cache_command,
_("Show index-cache options."), &show_index_cache_prefix_list,
false, &showlist);
/* set/show index-cache enabled */
set_show_commands setshow_index_cache_enabled_cmds
= add_setshow_boolean_cmd ("enabled", class_files,
_("Enable the index cache."),
_("Show whether the index cache is enabled."),
_("When on, enable the use of the index cache."),
set_index_cache_enabled_command,
get_index_cache_enabled_command,
show_index_cache_enabled_command,
&set_index_cache_prefix_list,
&show_index_cache_prefix_list);
/* set index-cache on */
cmd_list_element *set_index_cache_on_cmd
= add_alias_cmd ("on", setshow_index_cache_enabled_cmds.set, class_files,
false, &set_index_cache_prefix_list);
deprecate_cmd (set_index_cache_on_cmd, "set index-cache enabled on");
set_index_cache_on_cmd->default_args = "on";
/* set index-cache off */
cmd_list_element *set_index_cache_off_cmd
= add_alias_cmd ("off", setshow_index_cache_enabled_cmds.set, class_files,
false, &set_index_cache_prefix_list);
deprecate_cmd (set_index_cache_off_cmd, "set index-cache enabled off");
set_index_cache_off_cmd->default_args = "off";
/* set index-cache directory */
add_setshow_filename_cmd ("directory", class_files, &index_cache_directory,
_("Set the directory of the index cache."),
_("Show the directory of the index cache."),
NULL,
set_index_cache_directory_command, NULL,
&set_index_cache_prefix_list,
&show_index_cache_prefix_list);
/* show index-cache stats */
add_cmd ("stats", class_files, show_index_cache_stats_command,
_("Show some stats about the index cache."),
&show_index_cache_prefix_list);
/* set debug index-cache */
add_setshow_boolean_cmd ("index-cache", class_maintenance,
&debug_index_cache,
_("Set display of index-cache debug messages."),
_("Show display of index-cache debug messages."),
_("\
When non-zero, debugging output for the index cache is displayed."),
NULL, NULL,
&setdebuglist, &showdebuglist);
}