1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
|
/* Caching of GDB/DWARF index files.
Copyright (C) 1994-2019 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/scoped_mmap.h"
#include "common/pathstuff.h"
#include "dwarf-index-write.h"
#include "dwarf2read.h"
#include "objfiles.h"
#include "common/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;
/* 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);
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. */
if (!mkdir_recursive (m_dir.c_str ()))
{
warning (_("index cache: could not make cache directory: %s\n"),
safe_strerror (errno));
return;
}
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 (), dw_index_kind::GDB_INDEX);
}
catch (const gdb_exception_RETURN_MASK_ERROR &except)
{
if (debug_index_cache)
printf_unfiltered ("index cache: 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
{
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 (const gdb_exception_RETURN_MASK_ERROR &except)
{
if (debug_index_cache)
printf_unfiltered ("index cache: couldn't read %s: %s\n",
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;
}
/* "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)
{
/* Make sure the index cache directory is absolute and tilde-expanded. */
gdb::unique_xmalloc_ptr<char> abs (gdb_abspath (index_cache_directory));
xfree (index_cache_directory);
index_cache_directory = abs.release ();
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 ());
}
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 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);
}
|