gdb/xml-syscall.c - gdb

Global variables defined

Data types defined

Functions defined

Source code

  1. /* Functions that provide the mechanism to parse a syscall XML file
  2.    and get its values.

  4.    Copyright (C) 2009-2015 Free Software Foundation, Inc.

  6.    This file is part of GDB.

  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.

  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.

  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/>.  */

  21. #include "defs.h"
  22. #include "gdbtypes.h"
  23. #include "xml-support.h"
  24. #include "xml-syscall.h"
  25. #include "gdbarch.h"

  27. /* For the struct syscall definition.  */
  28. #include "target.h"

  30. #include "filenames.h"

  32. #ifndef HAVE_LIBEXPAT

  34. /* Dummy functions to indicate that there's no support for fetching
  35.    syscalls information.  */

  37. static void
  38. ‌syscall_warn_user (void)
  39. {
  40.   static int have_warned = 0;
  41.   if (!have_warned)
  42.     {
  43.       have_warned = 1;
  44.       warning (_("Can not parse XML syscalls information; XML support was "
  45.                  "disabled at compile time."));
  46.     }
  47. }

  49. void
  50. ‌set_xml_syscall_file_name (struct gdbarch *gdbarch, const char *name)
  51. {
  52.   return;
  53. }

  55. void
  56. ‌get_syscall_by_number (struct gdbarch *gdbarch,
  57.                        int syscall_number, struct syscall *s)
  58. {
  59.   syscall_warn_user ();
  60.   s->number = syscall_number;
  61.   s->name = NULL;
  62. }

  64. void
  65. ‌get_syscall_by_name (struct gdbarch *gdbarch, const char *syscall_name,
  66.                      struct syscall *s)
  67. {
  68.   syscall_warn_user ();
  69.   s->number = UNKNOWN_SYSCALL;
  70.   s->name = syscall_name;
  71. }

  73. const char **
  74. ‌get_syscall_names (struct gdbarch *gdbarch)
  75. {
  76.   syscall_warn_user ();
  77.   return NULL;
  78. }

  80. #else /* ! HAVE_LIBEXPAT */

  82. /* Structure which describes a syscall.  */
  83. ‌typedef struct syscall_desc
  84. {
  85.   /* The syscall number.  */

  87.   int number;

  89.   /* The syscall name.  */

  91.   char *name;
  92. ‌} *syscall_desc_p;
  93. ‌DEF_VEC_P(syscall_desc_p);

  95. /* Structure that represents syscalls information.  */
  96. ‌struct syscalls_info
  97. {
  98.   /* The syscalls.  */

  100.   VEC(syscall_desc_p) *syscalls;

  102.   /* Variable that will hold the last known data-directory.  This is
  103.      useful to know whether we should re-read the XML info for the
  104.      target.  */

  106.   char *my_gdb_datadir;
  107. };

  109. /* Callback data for syscall information parsing.  */
  110. ‌struct syscall_parsing_data
  111. {
  112.   /* The syscalls_info we are building.  */

  114.   struct syscalls_info *syscalls_info;
  115. };

  117. static struct syscalls_info *
  118. ‌allocate_syscalls_info (void)
  119. {
  120.   return XCNEW (struct syscalls_info);
  121. }

  123. static void
  124. ‌syscalls_info_free_syscalls_desc (struct syscall_desc *sd)
  125. {
  126.   xfree (sd->name);
  127. }

  129. static void
  130. ‌free_syscalls_info (void *arg)
  131. {
  132.   struct syscalls_info *syscalls_info = arg;
  133.   struct syscall_desc *sysdesc;
  134.   int i;

  136.   xfree (syscalls_info->my_gdb_datadir);

  138.   if (syscalls_info->syscalls != NULL)
  139.     {
  140.       for (i = 0;
  141.            VEC_iterate (syscall_desc_p, syscalls_info->syscalls, i, sysdesc);
  142.            i++)
  143.         syscalls_info_free_syscalls_desc (sysdesc);
  144.       VEC_free (syscall_desc_p, syscalls_info->syscalls);
  145.     }

  147.   xfree (syscalls_info);
  148. }

  150. static struct cleanup *
  151. ‌make_cleanup_free_syscalls_info (struct syscalls_info *syscalls_info)
  152. {
  153.   return make_cleanup (free_syscalls_info, syscalls_info);
  154. }

  156. static void
  157. ‌syscall_create_syscall_desc (struct syscalls_info *syscalls_info,
  158.                              const char *name, int number)
  159. {
  160.   struct syscall_desc *sysdesc = XCNEW (struct syscall_desc);

  162.   sysdesc->name = xstrdup (name);
  163.   sysdesc->number = number;

  165.   VEC_safe_push (syscall_desc_p, syscalls_info->syscalls, sysdesc);
  166. }

  168. /* Handle the start of a <syscall> element.  */
  169. static void
  170. ‌syscall_start_syscall (struct gdb_xml_parser *parser,
  171.                        const struct gdb_xml_element *element,
  172.                        void *user_data, VEC(gdb_xml_value_s) *attributes)
  173. {
  174.   struct syscall_parsing_data *data = user_data;
  175.   struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
  176.   int len, i;
  177.   /* syscall info.  */
  178.   char *name = NULL;
  179.   int number = 0;

  181.   len = VEC_length (gdb_xml_value_s, attributes);

  183.   for (i = 0; i < len; i++)
  184.     {
  185.       if (strcmp (attrs[i].name, "name") == 0)
  186.         name = attrs[i].value;
  187.       else if (strcmp (attrs[i].name, "number") == 0)
  188.         number = * (ULONGEST *) attrs[i].value;
  189.       else
  190.         internal_error (__FILE__, __LINE__,
  191.                         _("Unknown attribute name '%s'."), attrs[i].name);
  192.     }

  194.   gdb_assert (name);
  195.   syscall_create_syscall_desc (data->syscalls_info, name, number);
  196. }


  199. /* The elements and attributes of an XML syscall document.  */
  200. ‌static const struct gdb_xml_attribute syscall_attr[] = {
  201.   { "number", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
  202.   { "name", GDB_XML_AF_NONE, NULL, NULL },
  203.   { NULL, GDB_XML_AF_NONE, NULL, NULL }
  204. };

  206. ‌static const struct gdb_xml_element syscalls_info_children[] = {
  207.   { "syscall", syscall_attr, NULL,
  208.     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
  209.     syscall_start_syscall, NULL },
  210.   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
  211. };

  213. ‌static const struct gdb_xml_element syselements[] = {
  214.   { "syscalls_info", NULL, syscalls_info_children,
  215.     GDB_XML_EF_NONE, NULL, NULL },
  216.   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
  217. };

  219. static struct syscalls_info *
  220. ‌syscall_parse_xml (const char *document, xml_fetch_another fetcher,
  221.                    void *fetcher_baton)
  222. {
  223.   struct cleanup *result_cleanup;
  224.   struct syscall_parsing_data data;

  226.   data.syscalls_info = allocate_syscalls_info ();
  227.   result_cleanup = make_cleanup_free_syscalls_info (data.syscalls_info);

  229.   if (gdb_xml_parse_quick (_("syscalls info"), NULL,
  230.                            syselements, document, &data) == 0)
  231.     {
  232.       /* Parsed successfully.  */
  233.       discard_cleanups (result_cleanup);
  234.       return data.syscalls_info;
  235.     }
  236.   else
  237.     {
  238.       warning (_("Could not load XML syscalls info; ignoring"));
  239.       do_cleanups (result_cleanup);
  240.       return NULL;
  241.     }
  242. }

  244. /* Function responsible for initializing the information
  245.    about the syscalls.  It reads the XML file and fills the
  246.    struct syscalls_info with the values.

  248.    Returns the struct syscalls_info if the file is valid, NULL otherwise.  */
  249. static struct syscalls_info *
  250. ‌xml_init_syscalls_info (const char *filename)
  251. {
  252.   char *full_file;
  253.   char *dirname;
  254.   struct syscalls_info *syscalls_info;
  255.   struct cleanup *back_to;

  257.   full_file = xml_fetch_content_from_file (filename, gdb_datadir);
  258.   if (full_file == NULL)
  259.     return NULL;

  261.   back_to = make_cleanup (xfree, full_file);

  263.   dirname = ldirname (filename);
  264.   if (dirname != NULL)
  265.     make_cleanup (xfree, dirname);

  267.   syscalls_info = syscall_parse_xml (full_file,
  268.                                      xml_fetch_content_from_file, dirname);
  269.   do_cleanups (back_to);

  271.   return syscalls_info;
  272. }

  274. /* Initializes the syscalls_info structure according to the
  275.    architecture.  */
  276. static void
  277. ‌init_syscalls_info (struct gdbarch *gdbarch)
  278. {
  279.   struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
  280.   const char *xml_syscall_file = gdbarch_xml_syscall_file (gdbarch);

  282.   /* Should we re-read the XML info for this target?  */
  283.   if (syscalls_info != NULL && syscalls_info->my_gdb_datadir != NULL
  284.       && filename_cmp (syscalls_info->my_gdb_datadir, gdb_datadir) != 0)
  285.     {
  286.       /* The data-directory changed from the last time we used it.
  287.          It means that we have to re-read the XML info.  */
  288.       free_syscalls_info (syscalls_info);
  289.       syscalls_info = NULL;
  290.       set_gdbarch_syscalls_info (gdbarch, NULL);
  291.     }

  293.   /* Did we succeed at initializing this?  */
  294.   if (syscalls_info != NULL)
  295.     return;

  297.   syscalls_info = xml_init_syscalls_info (xml_syscall_file);

  299.   /* If there was some error reading the XML file, we initialize
  300.      gdbarch->syscalls_info anyway, in order to store information
  301.      about our attempt.  */
  302.   if (syscalls_info == NULL)
  303.     syscalls_info = allocate_syscalls_info ();

  305.   if (syscalls_info->syscalls == NULL)
  306.     {
  307.       if (xml_syscall_file != NULL)
  308.         warning (_("Could not load the syscall XML file `%s/%s'."),
  309.                  gdb_datadir, xml_syscall_file);
  310.       else
  311.         warning (_("There is no XML file to open."));

  313.       warning (_("GDB will not be able to display "
  314.                  "syscall names nor to verify if\n"
  315.                  "any provided syscall numbers are valid."));
  316.     }

  318.   /* Saving the data-directory used to read this XML info.  */
  319.   syscalls_info->my_gdb_datadir = xstrdup (gdb_datadir);

  321.   set_gdbarch_syscalls_info (gdbarch, syscalls_info);
  322. }

  324. static int
  325. ‌xml_get_syscall_number (struct gdbarch *gdbarch,
  326.                         const char *syscall_name)
  327. {
  328.   struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
  329.   struct syscall_desc *sysdesc;
  330.   int i;

  332.   if (syscalls_info == NULL
  333.       || syscall_name == NULL)
  334.     return UNKNOWN_SYSCALL;

  336.   for (i = 0;
  337.        VEC_iterate(syscall_desc_p, syscalls_info->syscalls, i, sysdesc);
  338.        i++)
  339.     if (strcmp (sysdesc->name, syscall_name) == 0)
  340.       return sysdesc->number;

  342.   return UNKNOWN_SYSCALL;
  343. }

  345. static const char *
  346. ‌xml_get_syscall_name (struct gdbarch *gdbarch,
  347.                       int syscall_number)
  348. {
  349.   struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
  350.   struct syscall_desc *sysdesc;
  351.   int i;

  353.   if (syscalls_info == NULL
  354.       || syscall_number < 0)
  355.     return NULL;

  357.   for (i = 0;
  358.        VEC_iterate(syscall_desc_p, syscalls_info->syscalls, i, sysdesc);
  359.        i++)
  360.     if (sysdesc->number == syscall_number)
  361.       return sysdesc->name;

  363.   return NULL;
  364. }

  366. static const char **
  367. ‌xml_list_of_syscalls (struct gdbarch *gdbarch)
  368. {
  369.   struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
  370.   struct syscall_desc *sysdesc;
  371.   const char **names = NULL;
  372.   int nsyscalls;
  373.   int i;

  375.   if (syscalls_info == NULL)
  376.     return NULL;

  378.   nsyscalls = VEC_length (syscall_desc_p, syscalls_info->syscalls);
  379.   names = xmalloc ((nsyscalls + 1) * sizeof (char *));

  381.   for (i = 0;
  382.        VEC_iterate (syscall_desc_p, syscalls_info->syscalls, i, sysdesc);
  383.        i++)
  384.     names[i] = sysdesc->name;

  386.   names[i] = NULL;

  388.   return names;
  389. }

  391. void
  392. ‌set_xml_syscall_file_name (struct gdbarch *gdbarch, const char *name)
  393. {
  394.   set_gdbarch_xml_syscall_file (gdbarch, name);
  395. }

  397. void
  398. ‌get_syscall_by_number (struct gdbarch *gdbarch,
  399.                        int syscall_number, struct syscall *s)
  400. {
  401.   init_syscalls_info (gdbarch);

  403.   s->number = syscall_number;
  404.   s->name = xml_get_syscall_name (gdbarch, syscall_number);
  405. }

  407. void
  408. ‌get_syscall_by_name (struct gdbarch *gdbarch,
  409.                      const char *syscall_name, struct syscall *s)
  410. {
  411.   init_syscalls_info (gdbarch);

  413.   s->number = xml_get_syscall_number (gdbarch, syscall_name);
  414.   s->name = syscall_name;
  415. }

  417. const char **
  418. ‌get_syscall_names (struct gdbarch *gdbarch)
  419. {
  420.   init_syscalls_info (gdbarch);

  422.   return xml_list_of_syscalls (gdbarch);
  423. }

  425. #endif /* ! HAVE_LIBEXPAT */