| 1 | /* Functions that provide the mechanism to parse a syscall XML file |
| 2 | and get its values. |
| 3 | |
| 4 | Copyright (C) 2009, 2010 Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 3 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "gdbtypes.h" |
| 23 | #include "xml-support.h" |
| 24 | #include "xml-syscall.h" |
| 25 | |
| 26 | /* For the struct syscall definition. */ |
| 27 | #include "target.h" |
| 28 | |
| 29 | #include "filenames.h" |
| 30 | |
| 31 | #include "gdb_assert.h" |
| 32 | |
| 33 | #ifndef HAVE_LIBEXPAT |
| 34 | |
| 35 | /* Dummy functions to indicate that there's no support for fetching |
| 36 | syscalls information. */ |
| 37 | |
| 38 | static void |
| 39 | syscall_warn_user (void) |
| 40 | { |
| 41 | static int have_warned = 0; |
| 42 | if (!have_warned) |
| 43 | { |
| 44 | have_warned = 1; |
| 45 | warning (_("Can not parse XML syscalls information; XML support was " |
| 46 | "disabled at compile time.")); |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | void |
| 51 | set_xml_syscall_file_name (const char *name) |
| 52 | { |
| 53 | return; |
| 54 | } |
| 55 | |
| 56 | void |
| 57 | get_syscall_by_number (int syscall_number, |
| 58 | struct syscall *s) |
| 59 | { |
| 60 | syscall_warn_user (); |
| 61 | s->number = syscall_number; |
| 62 | s->name = NULL; |
| 63 | } |
| 64 | |
| 65 | void |
| 66 | get_syscall_by_name (const char *syscall_name, |
| 67 | struct syscall *s) |
| 68 | { |
| 69 | syscall_warn_user (); |
| 70 | s->number = UNKNOWN_SYSCALL; |
| 71 | s->name = syscall_name; |
| 72 | } |
| 73 | |
| 74 | const char ** |
| 75 | get_syscall_names (void) |
| 76 | { |
| 77 | syscall_warn_user (); |
| 78 | return NULL; |
| 79 | } |
| 80 | |
| 81 | #else /* ! HAVE_LIBEXPAT */ |
| 82 | |
| 83 | /* Variable that will hold the last known data-directory. This is useful to |
| 84 | know whether we should re-read the XML info for the target. */ |
| 85 | static char *my_gdb_datadir = NULL; |
| 86 | |
| 87 | /* Structure which describes a syscall. */ |
| 88 | typedef struct syscall_desc |
| 89 | { |
| 90 | /* The syscall number. */ |
| 91 | |
| 92 | int number; |
| 93 | |
| 94 | /* The syscall name. */ |
| 95 | |
| 96 | char *name; |
| 97 | } *syscall_desc_p; |
| 98 | DEF_VEC_P(syscall_desc_p); |
| 99 | |
| 100 | /* Structure that represents syscalls information. */ |
| 101 | struct syscalls_info |
| 102 | { |
| 103 | /* The syscalls. */ |
| 104 | |
| 105 | VEC(syscall_desc_p) *syscalls; |
| 106 | }; |
| 107 | |
| 108 | /* Callback data for syscall information parsing. */ |
| 109 | struct syscall_parsing_data |
| 110 | { |
| 111 | /* The syscalls_info we are building. */ |
| 112 | |
| 113 | struct syscalls_info *sysinfo; |
| 114 | }; |
| 115 | |
| 116 | /* Structure used to store information about the available syscalls in |
| 117 | the system. */ |
| 118 | static const struct syscalls_info *sysinfo = NULL; |
| 119 | |
| 120 | /* A flag to tell if we already initialized the structure above. */ |
| 121 | static int have_initialized_sysinfo = 0; |
| 122 | |
| 123 | /* The filename of the syscall's XML. */ |
| 124 | static const char *xml_syscall_file = NULL; |
| 125 | |
| 126 | static struct syscalls_info * |
| 127 | allocate_syscalls_info (void) |
| 128 | { |
| 129 | return XZALLOC (struct syscalls_info); |
| 130 | } |
| 131 | |
| 132 | static void |
| 133 | sysinfo_free_syscalls_desc (struct syscall_desc *sd) |
| 134 | { |
| 135 | xfree (sd->name); |
| 136 | } |
| 137 | |
| 138 | static void |
| 139 | free_syscalls_info (void *arg) |
| 140 | { |
| 141 | struct syscalls_info *sysinfo = arg; |
| 142 | struct syscall_desc *sysdesc; |
| 143 | int i; |
| 144 | |
| 145 | for (i = 0; |
| 146 | VEC_iterate (syscall_desc_p, sysinfo->syscalls, i, sysdesc); |
| 147 | i++) |
| 148 | sysinfo_free_syscalls_desc (sysdesc); |
| 149 | VEC_free (syscall_desc_p, sysinfo->syscalls); |
| 150 | |
| 151 | xfree (sysinfo); |
| 152 | } |
| 153 | |
| 154 | struct cleanup * |
| 155 | make_cleanup_free_syscalls_info (struct syscalls_info *sysinfo) |
| 156 | { |
| 157 | return make_cleanup (free_syscalls_info, sysinfo); |
| 158 | } |
| 159 | |
| 160 | static void |
| 161 | syscall_create_syscall_desc (struct syscalls_info *sysinfo, |
| 162 | const char *name, int number) |
| 163 | { |
| 164 | struct syscall_desc *sysdesc = XZALLOC (struct syscall_desc); |
| 165 | |
| 166 | sysdesc->name = xstrdup (name); |
| 167 | sysdesc->number = number; |
| 168 | |
| 169 | VEC_safe_push (syscall_desc_p, sysinfo->syscalls, sysdesc); |
| 170 | } |
| 171 | |
| 172 | /* Handle the start of a <syscall> element. */ |
| 173 | static void |
| 174 | syscall_start_syscall (struct gdb_xml_parser *parser, |
| 175 | const struct gdb_xml_element *element, |
| 176 | void *user_data, VEC(gdb_xml_value_s) *attributes) |
| 177 | { |
| 178 | struct syscall_parsing_data *data = user_data; |
| 179 | struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes); |
| 180 | int len, i; |
| 181 | /* syscall info. */ |
| 182 | char *name = NULL; |
| 183 | int number = 0; |
| 184 | |
| 185 | len = VEC_length (gdb_xml_value_s, attributes); |
| 186 | |
| 187 | for (i = 0; i < len; i++) |
| 188 | { |
| 189 | if (strcmp (attrs[i].name, "name") == 0) |
| 190 | name = attrs[i].value; |
| 191 | else if (strcmp (attrs[i].name, "number") == 0) |
| 192 | number = * (ULONGEST *) attrs[i].value; |
| 193 | else |
| 194 | internal_error (__FILE__, __LINE__, |
| 195 | _("Unknown attribute name '%s'."), attrs[i].name); |
| 196 | } |
| 197 | |
| 198 | syscall_create_syscall_desc (data->sysinfo, name, number); |
| 199 | } |
| 200 | |
| 201 | |
| 202 | /* The elements and attributes of an XML syscall document. */ |
| 203 | static const struct gdb_xml_attribute syscall_attr[] = { |
| 204 | { "number", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL }, |
| 205 | { "name", GDB_XML_AF_NONE, NULL, NULL }, |
| 206 | { NULL, GDB_XML_AF_NONE, NULL, NULL } |
| 207 | }; |
| 208 | |
| 209 | static const struct gdb_xml_element syscalls_info_children[] = { |
| 210 | { "syscall", syscall_attr, NULL, |
| 211 | GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE, |
| 212 | syscall_start_syscall, NULL }, |
| 213 | { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } |
| 214 | }; |
| 215 | |
| 216 | static const struct gdb_xml_element syselements[] = { |
| 217 | { "syscalls_info", NULL, syscalls_info_children, |
| 218 | GDB_XML_EF_NONE, NULL, NULL }, |
| 219 | { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } |
| 220 | }; |
| 221 | |
| 222 | static struct syscalls_info * |
| 223 | syscall_parse_xml (const char *document, xml_fetch_another fetcher, |
| 224 | void *fetcher_baton) |
| 225 | { |
| 226 | struct cleanup *result_cleanup; |
| 227 | struct gdb_xml_parser *parser; |
| 228 | struct syscall_parsing_data data; |
| 229 | |
| 230 | parser = gdb_xml_create_parser_and_cleanup (_("syscalls info"), |
| 231 | syselements, &data); |
| 232 | |
| 233 | memset (&data, 0, sizeof (struct syscall_parsing_data)); |
| 234 | data.sysinfo = allocate_syscalls_info (); |
| 235 | result_cleanup = make_cleanup_free_syscalls_info (data.sysinfo); |
| 236 | |
| 237 | if (gdb_xml_parse (parser, document) == 0) |
| 238 | { |
| 239 | /* Parsed successfully. */ |
| 240 | discard_cleanups (result_cleanup); |
| 241 | return data.sysinfo; |
| 242 | } |
| 243 | else |
| 244 | { |
| 245 | warning (_("Could not load XML syscalls info; ignoring")); |
| 246 | do_cleanups (result_cleanup); |
| 247 | return NULL; |
| 248 | } |
| 249 | } |
| 250 | |
| 251 | /* Function responsible for initializing the information |
| 252 | about the syscalls. It reads the XML file and fills the |
| 253 | struct syscalls_info with the values. |
| 254 | |
| 255 | Returns the struct syscalls_info if the file is valid, NULL otherwise. */ |
| 256 | static const struct syscalls_info * |
| 257 | xml_init_syscalls_info (const char *filename) |
| 258 | { |
| 259 | char *full_file; |
| 260 | char *dirname; |
| 261 | struct syscalls_info *sysinfo; |
| 262 | struct cleanup *back_to; |
| 263 | |
| 264 | full_file = xml_fetch_content_from_file (filename, gdb_datadir); |
| 265 | if (full_file == NULL) |
| 266 | return NULL; |
| 267 | |
| 268 | back_to = make_cleanup (xfree, full_file); |
| 269 | |
| 270 | dirname = ldirname (filename); |
| 271 | if (dirname != NULL) |
| 272 | make_cleanup (xfree, dirname); |
| 273 | |
| 274 | sysinfo = syscall_parse_xml (full_file, xml_fetch_content_from_file, dirname); |
| 275 | do_cleanups (back_to); |
| 276 | |
| 277 | return sysinfo; |
| 278 | } |
| 279 | |
| 280 | /* Initializes the syscalls_info structure according to the |
| 281 | architecture. */ |
| 282 | static void |
| 283 | init_sysinfo (void) |
| 284 | { |
| 285 | /* Should we re-read the XML info for this target? */ |
| 286 | if (my_gdb_datadir && strcmp (my_gdb_datadir, gdb_datadir) != 0) |
| 287 | { |
| 288 | /* The data-directory changed from the last time we used it. |
| 289 | It means that we have to re-read the XML info. */ |
| 290 | have_initialized_sysinfo = 0; |
| 291 | xfree (my_gdb_datadir); |
| 292 | my_gdb_datadir = NULL; |
| 293 | if (sysinfo) |
| 294 | free_syscalls_info ((void *) sysinfo); |
| 295 | } |
| 296 | |
| 297 | /* Did we already try to initialize the structure? */ |
| 298 | if (have_initialized_sysinfo) |
| 299 | return; |
| 300 | |
| 301 | sysinfo = xml_init_syscalls_info (xml_syscall_file); |
| 302 | |
| 303 | have_initialized_sysinfo = 1; |
| 304 | |
| 305 | if (sysinfo == NULL) |
| 306 | { |
| 307 | if (xml_syscall_file) |
| 308 | warning (_("\ |
| 309 | Could not load the syscall XML file `%s/%s'."), |
| 310 | gdb_datadir, xml_syscall_file); |
| 311 | else |
| 312 | warning (_("\ |
| 313 | There is no XML file to open.")); |
| 314 | |
| 315 | warning (_("\ |
| 316 | GDB will not be able to display syscall names nor to verify if\n\ |
| 317 | any provided syscall numbers are valid.")); |
| 318 | } |
| 319 | |
| 320 | /* Saving the data-directory used to read this XML info. */ |
| 321 | my_gdb_datadir = xstrdup (gdb_datadir); |
| 322 | } |
| 323 | |
| 324 | static int |
| 325 | xml_get_syscall_number (const struct syscalls_info *sysinfo, |
| 326 | const char *syscall_name) |
| 327 | { |
| 328 | struct syscall_desc *sysdesc; |
| 329 | int i; |
| 330 | |
| 331 | if (sysinfo == NULL |
| 332 | || syscall_name == NULL) |
| 333 | return UNKNOWN_SYSCALL; |
| 334 | |
| 335 | for (i = 0; |
| 336 | VEC_iterate(syscall_desc_p, sysinfo->syscalls, i, sysdesc); |
| 337 | i++) |
| 338 | if (strcmp (sysdesc->name, syscall_name) == 0) |
| 339 | return sysdesc->number; |
| 340 | |
| 341 | return UNKNOWN_SYSCALL; |
| 342 | } |
| 343 | |
| 344 | static const char * |
| 345 | xml_get_syscall_name (const struct syscalls_info *sysinfo, |
| 346 | int syscall_number) |
| 347 | { |
| 348 | struct syscall_desc *sysdesc; |
| 349 | int i; |
| 350 | |
| 351 | if (sysinfo == NULL |
| 352 | || syscall_number < 0) |
| 353 | return NULL; |
| 354 | |
| 355 | for (i = 0; |
| 356 | VEC_iterate(syscall_desc_p, sysinfo->syscalls, i, sysdesc); |
| 357 | i++) |
| 358 | if (sysdesc->number == syscall_number) |
| 359 | return sysdesc->name; |
| 360 | |
| 361 | return NULL; |
| 362 | } |
| 363 | |
| 364 | static const char ** |
| 365 | xml_list_of_syscalls (const struct syscalls_info *sysinfo) |
| 366 | { |
| 367 | struct syscall_desc *sysdesc; |
| 368 | const char **names = NULL; |
| 369 | int nsyscalls; |
| 370 | int i; |
| 371 | |
| 372 | if (sysinfo == NULL) |
| 373 | return NULL; |
| 374 | |
| 375 | nsyscalls = VEC_length (syscall_desc_p, sysinfo->syscalls); |
| 376 | names = xmalloc ((nsyscalls + 1) * sizeof (char *)); |
| 377 | |
| 378 | for (i = 0; |
| 379 | VEC_iterate (syscall_desc_p, sysinfo->syscalls, i, sysdesc); |
| 380 | i++) |
| 381 | names[i] = sysdesc->name; |
| 382 | |
| 383 | names[i] = NULL; |
| 384 | |
| 385 | return names; |
| 386 | } |
| 387 | |
| 388 | void |
| 389 | set_xml_syscall_file_name (const char *name) |
| 390 | { |
| 391 | xml_syscall_file = name; |
| 392 | } |
| 393 | |
| 394 | void |
| 395 | get_syscall_by_number (int syscall_number, |
| 396 | struct syscall *s) |
| 397 | { |
| 398 | init_sysinfo (); |
| 399 | |
| 400 | s->number = syscall_number; |
| 401 | s->name = xml_get_syscall_name (sysinfo, syscall_number); |
| 402 | } |
| 403 | |
| 404 | void |
| 405 | get_syscall_by_name (const char *syscall_name, |
| 406 | struct syscall *s) |
| 407 | { |
| 408 | init_sysinfo (); |
| 409 | |
| 410 | s->number = xml_get_syscall_number (sysinfo, syscall_name); |
| 411 | s->name = syscall_name; |
| 412 | } |
| 413 | |
| 414 | const char ** |
| 415 | get_syscall_names (void) |
| 416 | { |
| 417 | init_sysinfo (); |
| 418 | |
| 419 | return xml_list_of_syscalls (sysinfo); |
| 420 | } |
| 421 | |
| 422 | #endif /* ! HAVE_LIBEXPAT */ |