@@ -1001,6 +1001,7 @@ COMMON_SFILES = \
disasm.c \
disasm-selftests.c \
dummy-frame.c \
+ dwarf-index-cache.c \
dwarf-index-common.c \
dwarf-index-write.c \
dwarf2-frame.c \
@@ -1224,6 +1225,7 @@ HFILES_NO_SRCDIR = \
dictionary.h \
disasm.h \
dummy-frame.h \
+ dwarf-index-cache.h \
dwarf-index-common.h \
dwarf2-frame.h \
dwarf2-frame-tailcall.h \
@@ -21,6 +21,7 @@
#define BUILD_ID_H
#include "gdb_bfd.h"
+#include "common/rsp-low.h"
/* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
@@ -47,4 +48,14 @@ extern gdb_bfd_ref_ptr build_id_to_debug_bfd (size_t build_id_len,
extern std::string find_separate_debug_file_by_buildid
(struct objfile *objfile);
+/* Return an hex-string representation of BUILD_ID. */
+
+static inline std::string
+build_id_to_string (const bfd_build_id *build_id)
+{
+ gdb_assert (build_id != NULL);
+
+ return bin2hex (build_id->data, build_id->size);
+}
+
#endif /* BUILD_ID_H */
@@ -158,3 +158,19 @@ contains_dir_separator (const char *path)
return false;
}
+
+/* See common/pathstuff.h. */
+
+std::string
+get_standard_cache_dir ()
+{
+ char *xdg_cache_home = getenv ("XDG_CACHE_HOME");
+ if (xdg_cache_home != NULL)
+ return string_printf ("%s/gdb", xdg_cache_home);
+
+ char *home = getenv ("HOME");
+ if (home != NULL)
+ return string_printf ("%s/.cache/gdb", home);
+
+ return {};
+}
@@ -50,4 +50,14 @@ extern gdb::unique_xmalloc_ptr<char> gdb_abspath (const char *path);
extern bool contains_dir_separator (const char *path);
+/* Get the usual user cache directory for the current platform.
+
+ On Linux, it follows the XDG Base Directory specification: use
+ $XDG_CACHE_HOME/gdb if the XDG_CACHE_HOME environment variable is defined,
+ otherwise $HOME/.cache.
+
+ Return an empty string if neither XDG_CACHE_HOME or HOME are defined. */
+
+extern std::string get_standard_cache_dir ();
+
#endif /* PATHSTUFF_H */
new file mode 100644
@@ -0,0 +1,474 @@
+/* Caching of GDB/DWARF index files.
+
+ Copyright (C) 1994-2018 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 "defs.h"
+#include "dwarf-index-cache.h"
+
+#include "build-id.h"
+#include "cli/cli-cmds.h"
+#include "command.h"
+#include "common/pathstuff.h"
+#include "common/scoped_mmapped_file.h"
+#include "dwarf-index-write.h"
+#include "dwarf2read.h"
+#include "objfiles.h"
+#include "selftest.h"
+#include <string>
+#include <stdlib.h>
+
+/* When set to 1, show debug messages about the index cache. */
+static int debug_index_cache = 0;
+
+/* The index cache directory, used for "set/show index-cache directory". */
+static char *index_cache_directory = NULL;
+
+/* See dwarf-index.cache.h. */
+index_cache global_index_cache;
+
+/* Stuff necessary for "set/show index-cache format". */
+static const char index_format_gdb[] = "gdb";
+static const char index_format_dwarf_5[] = "dwarf-5";
+static const char *index_formats[] = {
+ index_format_gdb,
+ index_format_dwarf_5,
+ nullptr,
+};
+
+/* Index format to use for the index cache. */
+static const char *index_cache_format_ = index_format_gdb;
+
+/* set/show index-cache commands. */
+static cmd_list_element *set_index_cache_prefix_list;
+static cmd_list_element *show_index_cache_prefix_list;
+
+/* Return the index format to use when writing files to the cache. */
+
+static dw_index_kind
+index_cache_format ()
+{
+ if (index_cache_format_ == index_format_gdb)
+ return dw_index_kind::GDB_INDEX;
+ else if (index_cache_format_ == index_format_dwarf_5)
+ return dw_index_kind::DEBUG_NAMES;
+ else
+ gdb_assert_not_reached (_("Invalid value for index cache format."));
+}
+
+
+/* A cheap (as in low-quality) recursive mkdir. Try to create all the parents
+ directories up to DIR and DIR itself. Stop if we hit an error along the way.
+ There is no attempt to remove created directories in case of failure. */
+
+static void
+mkdir_recursive (const char *dir)
+{
+ gdb::unique_xmalloc_ptr<char> holder (xstrdup (dir));
+ char * const start = holder.get ();
+ char *component_start = start;
+ char *component_end = start;
+
+ while (1)
+ {
+ /* Find the beginning of the next component. */
+ while (*component_start == '/')
+ component_start++;
+
+ /* Are we done? */
+ if (*component_start == '\0')
+ return;
+
+ /* Find the slash or null-terminator after this component. */
+ component_end = component_start;
+ while (*component_end != '/' && *component_end != '\0')
+ component_end++;
+
+ /* Temporarily replace the slash with a null terminator, so we can create
+ the directory up to this component. */
+ char saved_char = *component_end;
+ *component_end = '\0';
+
+ /* If we get EEXIST and the existing path is a directory, then we're
+ happy. If it exists, but it's a regular file and this is not the last
+ component, we'll fail at the next component. If this is the last
+ component, the caller will fail with ENOTDIR when trying to
+ open/create a file under that path. */
+ if (mkdir (start, 0700) != 0)
+ if (errno != EEXIST)
+ return;
+
+ /* Restore the overwritten char. */
+ *component_end = saved_char;
+ component_start = component_end;
+ }
+}
+
+/* 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);
+
+ if (debug_index_cache)
+ printf_unfiltered ("index cache: now using directory %s\n", m_dir.c_str ());
+}
+
+/* See dwarf-index-cache.h. */
+
+void
+index_cache::enable ()
+{
+ if (debug_index_cache)
+ printf_unfiltered ("index cache: enabling (%s)\n", m_dir.c_str ());
+
+ m_enabled = true;
+}
+
+/* See dwarf-index-cache.h. */
+
+void
+index_cache::disable ()
+{
+ if (debug_index_cache)
+ printf_unfiltered ("index cache: disabling\n");
+
+ m_enabled = false;
+}
+
+/* See dwarf-index-cache.h. */
+
+void
+index_cache::store (struct dwarf2_per_objfile *dwarf2_per_objfile)
+{
+ objfile *obj = dwarf2_per_objfile->objfile;
+
+ if (!enabled ())
+ return;
+
+ const bfd_build_id *build_id = build_id_bfd_get (obj->obfd);
+ if (build_id == nullptr)
+ {
+ if (debug_index_cache)
+ printf_unfiltered ("index cache: objfile %s has no build id\n",
+ objfile_name (obj));
+ return;
+ }
+
+ if (m_dir.empty ())
+ {
+ warning (_("The index cache directory name is empty, skipping store."));
+ return;
+ }
+
+ std::string build_id_str = build_id_to_string (build_id);
+
+ TRY
+ {
+ /* Try to create the containing directory. */
+ mkdir_recursive (m_dir.c_str ());
+
+ if (debug_index_cache)
+ printf_unfiltered ("index cache: writing index cache for objfile %s\n",
+ objfile_name (obj));
+
+ /* Write the index itself to the directory, using the build id as the
+ filename. */
+ write_psymtabs_to_index (dwarf2_per_objfile, m_dir.c_str (),
+ build_id_str.c_str (), index_cache_format ());
+ }
+ CATCH (except, RETURN_MASK_ERROR)
+ {
+ if (debug_index_cache)
+ printf_unfiltered ("index cache: couldn't store index cache for objfile "
+ "%s: %s", objfile_name (obj), except.message);
+ }
+ END_CATCH
+}
+
+#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 (filename)
+ {}
+
+ scoped_mmapped_file 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
+ {
+ if (debug_index_cache)
+ printf_unfiltered ("index cache: trying to read %s\n",
+ 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 (except, RETURN_MASK_ERROR)
+ {
+ if (debug_index_cache)
+ printf_unfiltered ("index cache: couldn't read %s: %s\n",
+ filename.c_str (), except.message);
+ }
+ END_CATCH
+
+ 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;
+}
+
+/* "set index-cache" handler. */
+
+static void
+set_index_cache_command (const char *arg, int from_tty)
+{
+ printf_unfiltered ("\
+Missing arguments. See \"help set index-cache\" for help.\n");
+}
+
+/* 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, "");
+
+ printf_unfiltered ("\n");
+ printf_unfiltered ("The index cache is currently %s.\n",
+ global_index_cache.enabled () ? "enabled" : "disabled");
+}
+
+/* "set index-cache on" handler. */
+
+static void
+set_index_cache_on_command (const char *arg, int from_tty)
+{
+ global_index_cache.enable ();
+}
+
+/* "set index-cache off" handler. */
+
+static void
+set_index_cache_off_command (const char *arg, int from_tty)
+{
+ global_index_cache.disable ();
+}
+
+/* "set index-cache directory" handler. */
+
+static void
+set_index_cache_directory_command (const char *arg, int from_tty,
+ cmd_list_element *element)
+{
+ 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 = " ";
+ printf_unfiltered ("\n");
+ }
+
+ printf_unfiltered ("%s Cache hits (this session): %u\n",
+ indent, global_index_cache.n_hits ());
+ printf_unfiltered ("%sCache misses (this session): %u\n",
+ indent, global_index_cache.n_misses ());
+}
+
+#if GDB_SELF_TEST && defined (HAVE_MKDTEMP)
+namespace selftests
+{
+
+/* Try to create DIR using mkdir_recursive and make sure it exists. */
+
+static bool
+create_dir_and_check (const char *dir)
+{
+ mkdir_recursive (dir);
+
+ struct stat st;
+ if (stat (dir, &st) != 0)
+ perror_with_name ("stat");
+
+ return (st.st_mode & S_IFDIR) != 0;
+}
+
+/* Test mkdir_recursive. */
+
+static void
+test_mkdir_recursive ()
+{
+ char base[] = "/tmp/gdb-selftests-XXXXXX";
+
+ if (mkdtemp (base) == NULL)
+ perror_with_name ("mkdtemp");
+
+ std::string dir = string_printf ("%s/a/b", base);
+ SELF_CHECK (create_dir_and_check (dir.c_str ()));
+
+ dir = string_printf ("%s/a/b/c//d/e/", base);
+ SELF_CHECK (create_dir_and_check (dir.c_str ()));
+}
+}
+#endif /* GDB_SELF_TEST && defined (HAVE_MKDTEMP) */
+
+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 = xstrdup (cache_dir.c_str ());
+ 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_prefix_cmd ("index-cache", class_files, set_index_cache_command,
+ _("Set index-cache options"), &set_index_cache_prefix_list,
+ "set index-cache ", 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,
+ "show index-cache ", false, &showlist);
+
+ /* set index-cache on */
+ add_cmd ("on", class_files, set_index_cache_on_command,
+ _("Enable the index cache."), &set_index_cache_prefix_list);
+
+ /* set index-cache off */
+ add_cmd ("off", class_files, set_index_cache_off_command,
+ _("Disable the index cache."), &set_index_cache_prefix_list);
+
+ /* set index-cache format */
+ add_setshow_enum_cmd ("format", class_files, index_formats,
+ &index_cache_format_, "\
+Set the index format to use for the index cache.", "\
+Show the index format to use for the index cache.", "\
+Index format to use for the index cache.", nullptr, nullptr,
+ &set_index_cache_prefix_list,
+ &show_index_cache_prefix_list);
+
+ /* 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);
+
+#if GDB_SELF_TEST && defined (HAVE_MKDTEMP)
+ selftests::register_test ("mkdir_recursive", selftests::test_mkdir_recursive);
+#endif
+}
new file mode 100644
@@ -0,0 +1,112 @@
+/* Caching of GDB/DWARF index files.
+
+ Copyright (C) 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/>. */
+
+#ifndef DWARF_INDEX_CACHE_H
+#define DWARF_INDEX_CACHE_H
+
+#include "dwarf-index-common.h"
+#include "common/array-view.h"
+#include "symfile.h"
+
+/* Base of the classes used to hold the resources of the indices loaded from
+ the cache (e.g. mmapped files). */
+
+struct index_cache_resource
+{
+ virtual ~index_cache_resource () = 0;
+};
+
+/* Class to manage the access to the DWARF index cache. */
+
+class index_cache
+{
+public:
+ /* Change the directory used to save/load index files. */
+ void set_directory (std::string &&dir);
+
+ /* Return true if the usage of the cache is enabled. */
+ bool enabled () const
+ {
+ return m_enabled;
+ }
+
+ /* Enable the cache. */
+ void enable ();
+
+ /* Disable the cache. */
+ void disable ();
+
+ /* Store an index for the specified object file in the cache. */
+ void store (struct dwarf2_per_objfile *dwarf2_per_objfile);
+
+ /* Look for an index file matching BUILD_ID. If found, return the contents
+ as an array_view and store the underlying resources (allocated memory,
+ mapped file, etc) in RESOURCE. The returned array_view is valid as long
+ as RESOURCE is not destroyed.
+
+ If no matching index file is found, return an empty array view. */
+ gdb::array_view<const gdb_byte>
+ lookup_gdb_index (const bfd_build_id *build_id,
+ std::unique_ptr<index_cache_resource> *resource);
+
+ /* Return the number of cache hits. */
+ unsigned int n_hits () const
+ { return m_n_hits; }
+
+ /* Record a cache hit. */
+ void hit ()
+ {
+ if (enabled ())
+ m_n_hits++;
+ }
+
+ /* Return the number of cache misses. */
+ unsigned int n_misses () const
+ { return m_n_misses; }
+
+ /* Record a cache miss. */
+ void miss ()
+ {
+ if (enabled ())
+ m_n_misses++;
+ }
+
+private:
+
+ /* Compute the absolute filename where the index of the objfile with build
+ id BUILD_ID will be stored. SUFFIX is appended at the end of the
+ filename. */
+ std::string make_index_filename (const bfd_build_id *build_id,
+ const char *suffix) const;
+
+ /* The base directory where we are storing and looking up index files. */
+ std::string m_dir;
+
+ /* Whether the cache is enabled. */
+ bool m_enabled = false;
+
+ /* Number of cache hits and misses during this GDB session. */
+ unsigned int m_n_hits = 0;
+ unsigned int m_n_misses = 0;
+};
+
+/* The global instance of the index cache. */
+extern index_cache global_index_cache;
+
+#endif /* DWARF_INDEX_CACHE_H */
@@ -20,6 +20,11 @@
#ifndef DWARF_INDEX_COMMON_H
#define DWARF_INDEX_COMMON_H
+/* The suffix for an index file. */
+#define INDEX4_SUFFIX ".gdb-index"
+#define INDEX5_SUFFIX ".debug_names"
+#define DEBUG_STR_SUFFIX ".debug_str"
+
/* All offsets in the index are of this type. It must be
architecture-independent. */
typedef uint32_t offset_type;
@@ -24,6 +24,7 @@
#include "common/byte-vector.h"
#include "common/filestuff.h"
#include "common/gdb_unlinker.h"
+#include "common/scoped_fd.h"
#include "complaints.h"
#include "dwarf-index-common.h"
#include "dwarf2.h"
@@ -39,11 +40,6 @@
#include <unordered_map>
#include <unordered_set>
-/* The suffix for an index file. */
-#define INDEX4_SUFFIX ".gdb-index"
-#define INDEX5_SUFFIX ".debug_names"
-#define DEBUG_STR_SUFFIX ".debug_str"
-
/* Ensure only legit values are used. */
#define DW2_GDB_INDEX_SYMBOL_STATIC_SET_VALUE(cu_index, value) \
do { \
@@ -1545,11 +1541,11 @@ assert_file_size (FILE *file, const char *filename, size_t expected_size)
gdb_assert (file_size == expected_size);
}
-/* Create an index file for OBJFILE in the directory DIR. */
+/* See dwarf-index-write.h. */
-static void
+void
write_psymtabs_to_index (struct dwarf2_per_objfile *dwarf2_per_objfile,
- const char *dir,
+ const char *dir, const char *basename,
dw_index_kind index_kind)
{
struct objfile *objfile = dwarf2_per_objfile->objfile;
@@ -1567,50 +1563,83 @@ write_psymtabs_to_index (struct dwarf2_per_objfile *dwarf2_per_objfile,
if (stat (objfile_name (objfile), &st) < 0)
perror_with_name (objfile_name (objfile));
- std::string filename (std::string (dir) + SLASH_STRING
- + lbasename (objfile_name (objfile))
+ /* Make a filename suitable to pass to mkstemp based on F (e.g.
+ /tmp/foo -> /tmp/foo-XXXXXX). */
+ auto make_temp_filename = [] (const std::string &f) -> gdb::char_vector
+ {
+ 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;
+ };
+
+ std::string filename (std::string (dir) + SLASH_STRING + basename
+ (index_kind == dw_index_kind::DEBUG_NAMES
? INDEX5_SUFFIX : INDEX4_SUFFIX));
+ gdb::char_vector filename_temp = make_temp_filename (filename);
- FILE *out_file = gdb_fopen_cloexec (filename.c_str (), "wb").release ();
- if (!out_file)
- error (_("Can't open `%s' for writing"), filename.c_str ());
+ scoped_fd out_file_fd (mkstemp (filename_temp.data ()));
+ if (out_file_fd.get () == -1)
+ perror_with_name ("mkstemp");
- /* Order matters here; we want FILE to be closed before FILENAME is
+ FILE *out_file = gdb_fopen_cloexec (filename_temp.data (), "wb").release ();
+ if (out_file == nullptr)
+ error (_("Can't open `%s' for writing"), filename_temp.data ());
+
+ /* Order matters here; we want FILE to be closed before FILENAME_TEMP is
unlinked, because on MS-Windows one cannot delete a file that is
still open. (Don't call anything here that might throw until
- file_closer is created.) */
- gdb::unlinker unlink_file (filename.c_str ());
+ file_closer is created.) We don't need OUT_FILE_FD anymore, so we might
+ as well close it now. */
+ out_file_fd.reset (-1);
+ gdb::unlinker unlink_file (filename_temp.data ());
gdb_file_up close_out_file (out_file);
if (index_kind == dw_index_kind::DEBUG_NAMES)
{
std::string filename_str (std::string (dir) + SLASH_STRING
- + lbasename (objfile_name (objfile))
- + DEBUG_STR_SUFFIX);
+ + basename + DEBUG_STR_SUFFIX);
+ gdb::char_vector filename_str_temp = make_temp_filename (filename_str);
+
+ scoped_fd out_file_str_fd (mkstemp (filename_str_temp.data ()));
+ if (out_file_str_fd.get () == -1)
+ perror_with_name ("mkstemp");
+
FILE *out_file_str
- = gdb_fopen_cloexec (filename_str.c_str (), "wb").release ();
- if (!out_file_str)
- error (_("Can't open `%s' for writing"), filename_str.c_str ());
- gdb::unlinker unlink_file_str (filename_str.c_str ());
+ = gdb_fopen_cloexec (filename_str_temp.data (), "wb").release ();
+ if (out_file_str == nullptr)
+ error (_("Can't open `%s' for writing"), filename_str_temp.data ());
+
+ out_file_str_fd.reset (-1);
+ gdb::unlinker unlink_file_str (filename_str_temp.data ());
gdb_file_up close_out_file_str (out_file_str);
const size_t total_len
= write_debug_names (dwarf2_per_objfile, out_file, out_file_str);
- assert_file_size (out_file, filename.c_str (), total_len);
+ assert_file_size (out_file, filename_temp.data (), total_len);
/* We want to keep the file .debug_str file too. */
unlink_file_str.keep ();
+
+ /* Close and move the str file in place. */
+ close_out_file_str.reset ();
+ if (rename (filename_str_temp.data (), filename_str.c_str ()) != 0)
+ perror_with_name ("rename");
}
else
{
const size_t total_len
= write_gdbindex (dwarf2_per_objfile, out_file);
- assert_file_size (out_file, filename.c_str (), total_len);
+ assert_file_size (out_file, filename_temp.data (), total_len);
}
/* We want to keep the file. */
unlink_file.keep ();
+
+ /* Close and move the file in place. */
+ close_out_file.reset ();
+ if (rename (filename_temp.data (), filename.c_str ()) != 0)
+ perror_with_name ("rename");
}
/* Implementation of the `save gdb-index' command.
@@ -1655,7 +1684,9 @@ save_gdb_index_command (const char *arg, int from_tty)
{
TRY
{
- write_psymtabs_to_index (dwarf2_per_objfile, arg, index_kind);
+ const char *basename = lbasename (objfile_name (objfile));
+ write_psymtabs_to_index (dwarf2_per_objfile, arg, basename,
+ index_kind);
}
CATCH (except, RETURN_MASK_ERROR)
{
new file mode 100644
@@ -0,0 +1,34 @@
+/* DWARF index writing support for GDB.
+
+ Copyright (C) 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/>. */
+
+#ifndef DWARF_INDEX_WRITE_H
+#define DWARF_INDEX_WRITE_H
+
+#include "symfile.h"
+#include "dwarf2read.h"
+
+/* Create an index file for OBJFILE in the directory DIR. BASENAME is the
+ desired filename, minus the extension, which gets added by this function
+ based on INDEX_KIND. */
+
+void write_psymtabs_to_index (struct dwarf2_per_objfile *dwarf2_per_objfile,
+ const char *dir, const char *basename,
+ dw_index_kind index_kind);
+
+#endif /* DWARF_INDEX_WRITE_H */
@@ -30,6 +30,7 @@
#include "defs.h"
#include "dwarf2read.h"
+#include "dwarf-index-cache.h"
#include "dwarf-index-common.h"
#include "bfd.h"
#include "elf-bfd.h"
@@ -864,6 +865,10 @@ struct dwz_file
/* The dwz's BFD. */
gdb_bfd_ref_ptr dwz_bfd;
+
+ /* If we loaded the index from an external file, this contains the
+ resources associated to the open file, memory mapping, etc. */
+ std::unique_ptr<index_cache_resource> index_cache_res;
};
/* Struct used to pass misc. parameters to read_die_and_children, et
@@ -6216,6 +6221,32 @@ get_debug_names_contents_from_section (objfile *obj, T *section_owner)
return {section->buffer, section->size};
}
+/* Lookup the index cache for the contents of the index associated to
+ DWARF2_OBJ. */
+
+static gdb::array_view<const gdb_byte>
+get_gdb_index_contents_from_cache (objfile *obj, dwarf2_per_objfile *dwarf2_obj)
+{
+ const bfd_build_id *build_id = build_id_bfd_get (obj->obfd);
+ if (build_id == nullptr)
+ return {};
+
+ return global_index_cache.lookup_gdb_index (build_id,
+ &dwarf2_obj->index_cache_res);
+}
+
+/* Same as the above, but for DWZ. */
+
+static gdb::array_view<const gdb_byte>
+get_gdb_index_contents_from_cache_dwz (objfile *obj, dwz_file *dwz)
+{
+ const bfd_build_id *build_id = build_id_bfd_get (dwz->dwz_bfd.get ());
+ if (build_id == nullptr)
+ return {};
+
+ return global_index_cache.lookup_gdb_index (build_id, &dwz->index_cache_res);
+}
+
/* See symfile.h. */
bool
@@ -6253,6 +6284,7 @@ dwarf2_initialize_objfile (struct objfile *objfile, dw_index_kind *index_kind)
return true;
}
+ /* First, try to read the index from a section of the object file... */
if (dwarf2_read_debug_names (dwarf2_per_objfile,
get_debug_names_contents_from_section<struct dwarf2_per_objfile>,
get_debug_names_contents_from_section<dwz_file>))
@@ -6269,6 +6301,17 @@ dwarf2_initialize_objfile (struct objfile *objfile, dw_index_kind *index_kind)
return true;
}
+ /* ... otherwise, try to find the index in the index cache. */
+ if (dwarf2_read_gdb_index (dwarf2_per_objfile,
+ get_gdb_index_contents_from_cache,
+ get_gdb_index_contents_from_cache_dwz))
+ {
+ global_index_cache.hit ();
+ *index_kind = dw_index_kind::GDB_INDEX;
+ return true;
+ }
+
+ global_index_cache.miss ();
return false;
}
@@ -6294,6 +6337,9 @@ dwarf2_build_psymtabs (struct objfile *objfile)
psymtab_discarder psymtabs (objfile);
dwarf2_build_psymtabs_hard (dwarf2_per_objfile);
psymtabs.keep ();
+
+ /* (maybe) store an index in the cache. */
+ global_index_cache.store (dwarf2_per_objfile);
}
CATCH (except, RETURN_MASK_ERROR)
{
@@ -20,6 +20,7 @@
#ifndef DWARF2READ_H
#define DWARF2READ_H
+#include "dwarf-index-cache.h"
#include "filename-seen-cache.h"
#include "gdb_obstack.h"
@@ -241,6 +242,10 @@ public:
/* Table containing all filenames. This is an optional because the
table is lazily constructed on first access. */
gdb::optional<filename_seen_cache> filenames_cache;
+
+ /* If we loaded the index from an external file, this contains the
+ resources associated to the open file, memory mapping, etc. */
+ std::unique_ptr<index_cache_resource> index_cache_res;
};
/* Get the dwarf2_per_objfile associated to OBJFILE. */
new file mode 100644
@@ -0,0 +1,23 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2018 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+int
+main ()
+{
+ return 0;
+}
+
new file mode 100644
@@ -0,0 +1,204 @@
+# Copyright 2018 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# This test checks that the index-cache feature generates the expected files at
+# the expected location.
+
+standard_testfile
+
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } {
+ return
+}
+
+# List the files in DIR on the host (where GDB-under-test runs).
+# Return a list of two elements:
+# - 0 on success, -1 on failure
+# - the list of files on success, empty on failure
+
+proc ls_host { dir } {
+ lassign [remote_exec host ls "-1 $dir"] ret output
+
+ if { $ret != 0 } {
+ fail "failed to list files on host in $dir"
+ return -1
+ }
+
+ # ls -1 returns a list separated by \r\n. split will return a bunch of
+ # empty entries (it treats a sequence of split characters as separate
+ # fields, plus there is a \r\n at the end of the result). Ignore empty
+ # list elements.
+ set filtered {}
+ set files [split $output \r\n]
+
+ foreach file $files {
+ if { $file != "" } {
+ lappend filtered $file
+ }
+ }
+
+ return "0 $filtered"
+}
+
+# Execute "show index-cache stats" and verify the output against expected
+# values.
+
+proc check_cache_stats { expected_hits expected_misses } {
+ set re [multi_line \
+ " Cache hits .this session.: $expected_hits" \
+ "Cache misses .this session.: $expected_misses" \
+ ]
+
+ gdb_test "show index-cache stats" $re "check index-cache stats"
+}
+
+# Run CODE using a fresh GDB configured based on the other parameters.
+
+proc run_test_with_flags { index_format cache_dir cache_enabled code } {
+ global GDBFLAGS testfile
+
+ save_vars { GDBFLAGS } {
+ set GDBFLAGS "$GDBFLAGS -iex \"set index-cache format $index_format\""
+ set GDBFLAGS "$GDBFLAGS -iex \"set index-cache directory $cache_dir\""
+ set GDBFLAGS "$GDBFLAGS -iex \"set index-cache $cache_enabled\""
+
+ clean_restart ${testfile}
+
+ uplevel 1 $code
+ }
+}
+
+# Test administrative stuff.
+
+proc_with_prefix test_basic_stuff { } {
+ global testfile
+
+ clean_restart ${testfile}
+
+ # Check that the index cache is disabled by default.
+ gdb_test \
+ "show index-cache" \
+ " is currently disabled." \
+ "index-cache is disabled by default"
+
+ # Test that we can enable it and "show index-cache" reflects that.
+ gdb_test_no_output "set index-cache on" "enable index cache"
+ gdb_test \
+ "show index-cache" \
+ " is currently enabled." \
+ "index-cache is now enabled"
+
+ # Test the "set/show index-cache directory" commands.
+ gdb_test "set index-cache directory" "Argument required.*" "set index-cache directory without arg"
+ gdb_test_no_output "set index-cache directory /tmp" "change the index cache directory"
+ gdb_test \
+ "show index-cache directory" \
+ "The directory of the index cache is \"/tmp\"." \
+ "show index cache directory"
+}
+
+# Test loading a binary with the cache disabled. No file should be created.
+
+proc_with_prefix test_cache_disabled { index_format cache_dir } {
+ lassign [ls_host $cache_dir] ret files_before
+
+ run_test_with_flags $index_format $cache_dir off {
+ lassign [ls_host $cache_dir] ret files_after
+
+ set nfiles_created [expr [llength $files_after] - [llength $files_before]]
+ gdb_assert "$nfiles_created == 0" "no files were created"
+
+ check_cache_stats 0 0
+ }
+}
+
+# Test with the cache enabled, we expect to have exactly one file created.
+
+proc_with_prefix test_cache_enabled_miss { index_format cache_dir } {
+ global testfile
+
+ lassign [ls_host $cache_dir] ret files_before
+
+ run_test_with_flags $index_format $cache_dir on {
+
+ lassign [ls_host $cache_dir] ret files_after
+ set nfiles_created [expr [llength $files_after] - [llength $files_before]]
+ gdb_assert "$nfiles_created > 0" "at least one file was created"
+
+ set build_id [get_build_id [standard_output_file ${testfile}]]
+ if { $build_id == "" } {
+ fail "couldn't get executable build id"
+ return
+ }
+
+ if { $index_format == "gdb" } {
+ set expected_created_file [list "${build_id}.gdb-index"]
+ } else {
+ set expected_created_file [list "${build_id}.debug_names"]
+ }
+
+ set found_idx [lsearch -exact $files_after $expected_created_file]
+ gdb_assert "$found_idx >= 0" "expected file is there"
+
+ remote_exec host rm "-f $cache_dir/$expected_created_file"
+
+ check_cache_stats 0 1
+ }
+}
+
+
+# Test with the cache enabled, this time we should have one file (the
+# same), but one cache read hit.
+
+proc_with_prefix test_cache_enabled_hit { index_format cache_dir } {
+ # Just to populate the cache.
+ run_test_with_flags $index_format $cache_dir on {}
+
+ lassign [ls_host $cache_dir] ret files_before
+
+ run_test_with_flags $index_format $cache_dir on {
+ lassign [ls_host $cache_dir] ret files_after
+ set nfiles_created [expr [llength $files_after] - [llength $files_before]]
+ gdb_assert "$nfiles_created == 0" "no files were created"
+
+ # Reading DWARF5 from cache is not implemented yet.
+ if { $index_format == "dwarf-5" } {
+ setup_xfail "*-*-*"
+ }
+ check_cache_stats 1 0
+ }
+}
+
+test_basic_stuff
+
+foreach_with_prefix index_format { "gdb" "dwarf-5" } {
+ # The cache dir should be on the host (possibly remote), so we can't use the
+ # standard output directory for that (it's on the build machine).
+ lassign [remote_exec host mktemp -d] ret cache_dir
+
+ if { $ret != 0 } {
+ fail "couldn't create temporary cache dir"
+ return
+ }
+
+ # The ouput of mktemp contains an end of line, remove it.
+ set cache_dir [string trimright $cache_dir \r\n]
+
+ test_cache_disabled $index_format $cache_dir
+ test_cache_enabled_miss $index_format $cache_dir
+ test_cache_enabled_hit $index_format $cache_dir
+
+ # Test again with the cache disabled, now that it is populated.
+ test_cache_disabled $index_format $cache_dir
+}
@@ -123,6 +123,30 @@ gdb_test_multiple "maint info sections .gdb_index .debug_names" "check for .gdb_
}
}
+# There also won't be any psymtabs if we read the index from the index cache.
+# We can detect this by looking if the index-cache is enabled and if the number
+# of cache misses is 0.
+set index_cache_misses -1
+gdb_test_multiple "show index-cache stats" "check index cache stats" {
+ -re ".*Cache misses \\(this session\\): (\\d+)\r\n.*$gdb_prompt $" {
+ set index_cache_misses $expect_out(1,string)
+ }
+}
+
+set using_index_cache 0
+gdb_test_multiple "show index-cache" "check index cache status" {
+ -re ".*is currently disabled.\r\n$gdb_prompt $" {
+ set using_index_cache 0
+ }
+ -re ".*is currently enabled.\r\n$gdb_prompt $" {
+ set using_index_cache 1
+ }
+}
+
+if { $index_cache_misses == 0 && $using_index_cache } {
+ set have_gdb_index 1
+}
+
#
# this command does not produce any output
# unless there is some problem with the symtabs and psymtabs