| /* Caching of GDB/DWARF index files. |
| |
| Copyright (C) 1994-2024 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 "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 <string> |
| #include <stdlib.h> |
| #include "run-on-main-thread.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 index-cache.h. */ |
| |
| index_cache_store_context::index_cache_store_context (const index_cache &ic, |
| dwarf2_per_bfd *per_bfd) |
| : m_enabled (ic.enabled ()), |
| m_dir (ic.m_dir), |
| m_per_bfd (per_bfd) |
| { |
| /* Capturing globals may only be done on the main thread. */ |
| gdb_assert (is_main_thread ()); |
| |
| if (!m_enabled) |
| return; |
| |
| /* Get build id of objfile. */ |
| const bfd_build_id *build_id = build_id_bfd_get (per_bfd->obfd); |
| if (build_id == nullptr) |
| { |
| index_cache_debug ("objfile %s has no build id", |
| bfd_get_filename (per_bfd->obfd)); |
| m_enabled = false; |
| return; |
| } |
| m_build_id_str = build_id_to_string (build_id); |
| |
| /* Get build id of dwz file, if present. */ |
| const dwz_file *dwz = dwarf2_get_dwz_file (per_bfd); |
| |
| 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 ()); |
| m_enabled = false; |
| return; |
| } |
| |
| m_dwz_build_id_str = build_id_to_string (dwz_build_id); |
| } |
| |
| if (m_dir.empty ()) |
| { |
| warning (_("The index cache directory name is empty, skipping store.")); |
| m_enabled = false; |
| 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)); |
| m_enabled = false; |
| return; |
| } |
| } |
| catch (const gdb_exception_error &except) |
| { |
| index_cache_debug ("couldn't store index cache for objfile %s: %s", |
| bfd_get_filename (per_bfd->obfd), except.what ()); |
| m_enabled = false; |
| } |
| } |
| |
| /* See dwarf-index-cache.h. */ |
| |
| void |
| index_cache_store_context::store () const |
| { |
| if (!m_enabled) |
| return; |
| |
| const char *dwz_build_id_ptr = (m_dwz_build_id_str.has_value () |
| ? m_dwz_build_id_str->c_str () |
| : nullptr); |
| |
| try |
| { |
| index_cache_debug ("writing index cache for objfile %s", |
| bfd_get_filename (m_per_bfd->obfd)); |
| |
| /* Write the index itself to the directory, using the build id as the |
| filename. */ |
| write_dwarf_index (m_per_bfd, m_dir.c_str (), |
| m_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", |
| bfd_get_filename (m_per_bfd->obfd), 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. */ |
| index_cache_directory = gdb_abspath (index_cache_directory); |
| 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); |
| } |