binutils-gdb/gdb/xml-syscall.c

419 lines
10 KiB
C

/* Functions that provide the mechanism to parse a syscall XML file
and get its values.
Copyright (C) 2009-2014 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 "gdbtypes.h"
#include "xml-support.h"
#include "xml-syscall.h"
/* For the struct syscall definition. */
#include "target.h"
#include "filenames.h"
#include "gdb_assert.h"
#ifndef HAVE_LIBEXPAT
/* Dummy functions to indicate that there's no support for fetching
syscalls information. */
static void
syscall_warn_user (void)
{
static int have_warned = 0;
if (!have_warned)
{
have_warned = 1;
warning (_("Can not parse XML syscalls information; XML support was "
"disabled at compile time."));
}
}
void
set_xml_syscall_file_name (const char *name)
{
return;
}
void
get_syscall_by_number (int syscall_number,
struct syscall *s)
{
syscall_warn_user ();
s->number = syscall_number;
s->name = NULL;
}
void
get_syscall_by_name (const char *syscall_name,
struct syscall *s)
{
syscall_warn_user ();
s->number = UNKNOWN_SYSCALL;
s->name = syscall_name;
}
const char **
get_syscall_names (void)
{
syscall_warn_user ();
return NULL;
}
#else /* ! HAVE_LIBEXPAT */
/* Variable that will hold the last known data-directory. This is useful to
know whether we should re-read the XML info for the target. */
static char *my_gdb_datadir = NULL;
/* Structure which describes a syscall. */
typedef struct syscall_desc
{
/* The syscall number. */
int number;
/* The syscall name. */
char *name;
} *syscall_desc_p;
DEF_VEC_P(syscall_desc_p);
/* Structure that represents syscalls information. */
struct syscalls_info
{
/* The syscalls. */
VEC(syscall_desc_p) *syscalls;
};
/* Callback data for syscall information parsing. */
struct syscall_parsing_data
{
/* The syscalls_info we are building. */
struct syscalls_info *sysinfo;
};
/* Structure used to store information about the available syscalls in
the system. */
static const struct syscalls_info *sysinfo = NULL;
/* A flag to tell if we already initialized the structure above. */
static int have_initialized_sysinfo = 0;
/* The filename of the syscall's XML. */
static const char *xml_syscall_file = NULL;
static struct syscalls_info *
allocate_syscalls_info (void)
{
return XCNEW (struct syscalls_info);
}
static void
sysinfo_free_syscalls_desc (struct syscall_desc *sd)
{
xfree (sd->name);
}
static void
free_syscalls_info (void *arg)
{
struct syscalls_info *sysinfo = arg;
struct syscall_desc *sysdesc;
int i;
for (i = 0;
VEC_iterate (syscall_desc_p, sysinfo->syscalls, i, sysdesc);
i++)
sysinfo_free_syscalls_desc (sysdesc);
VEC_free (syscall_desc_p, sysinfo->syscalls);
xfree (sysinfo);
}
static struct cleanup *
make_cleanup_free_syscalls_info (struct syscalls_info *sysinfo)
{
return make_cleanup (free_syscalls_info, sysinfo);
}
static void
syscall_create_syscall_desc (struct syscalls_info *sysinfo,
const char *name, int number)
{
struct syscall_desc *sysdesc = XCNEW (struct syscall_desc);
sysdesc->name = xstrdup (name);
sysdesc->number = number;
VEC_safe_push (syscall_desc_p, sysinfo->syscalls, sysdesc);
}
/* Handle the start of a <syscall> element. */
static void
syscall_start_syscall (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, VEC(gdb_xml_value_s) *attributes)
{
struct syscall_parsing_data *data = user_data;
struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
int len, i;
/* syscall info. */
char *name = NULL;
int number = 0;
len = VEC_length (gdb_xml_value_s, attributes);
for (i = 0; i < len; i++)
{
if (strcmp (attrs[i].name, "name") == 0)
name = attrs[i].value;
else if (strcmp (attrs[i].name, "number") == 0)
number = * (ULONGEST *) attrs[i].value;
else
internal_error (__FILE__, __LINE__,
_("Unknown attribute name '%s'."), attrs[i].name);
}
gdb_assert (name);
syscall_create_syscall_desc (data->sysinfo, name, number);
}
/* The elements and attributes of an XML syscall document. */
static const struct gdb_xml_attribute syscall_attr[] = {
{ "number", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
{ "name", GDB_XML_AF_NONE, NULL, NULL },
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
static const struct gdb_xml_element syscalls_info_children[] = {
{ "syscall", syscall_attr, NULL,
GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
syscall_start_syscall, NULL },
{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};
static const struct gdb_xml_element syselements[] = {
{ "syscalls_info", NULL, syscalls_info_children,
GDB_XML_EF_NONE, NULL, NULL },
{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};
static struct syscalls_info *
syscall_parse_xml (const char *document, xml_fetch_another fetcher,
void *fetcher_baton)
{
struct cleanup *result_cleanup;
struct syscall_parsing_data data;
data.sysinfo = allocate_syscalls_info ();
result_cleanup = make_cleanup_free_syscalls_info (data.sysinfo);
if (gdb_xml_parse_quick (_("syscalls info"), NULL,
syselements, document, &data) == 0)
{
/* Parsed successfully. */
discard_cleanups (result_cleanup);
return data.sysinfo;
}
else
{
warning (_("Could not load XML syscalls info; ignoring"));
do_cleanups (result_cleanup);
return NULL;
}
}
/* Function responsible for initializing the information
about the syscalls. It reads the XML file and fills the
struct syscalls_info with the values.
Returns the struct syscalls_info if the file is valid, NULL otherwise. */
static const struct syscalls_info *
xml_init_syscalls_info (const char *filename)
{
char *full_file;
char *dirname;
struct syscalls_info *sysinfo;
struct cleanup *back_to;
full_file = xml_fetch_content_from_file (filename, gdb_datadir);
if (full_file == NULL)
return NULL;
back_to = make_cleanup (xfree, full_file);
dirname = ldirname (filename);
if (dirname != NULL)
make_cleanup (xfree, dirname);
sysinfo = syscall_parse_xml (full_file,
xml_fetch_content_from_file, dirname);
do_cleanups (back_to);
return sysinfo;
}
/* Initializes the syscalls_info structure according to the
architecture. */
static void
init_sysinfo (void)
{
/* Should we re-read the XML info for this target? */
if (my_gdb_datadir && filename_cmp (my_gdb_datadir, gdb_datadir) != 0)
{
/* The data-directory changed from the last time we used it.
It means that we have to re-read the XML info. */
have_initialized_sysinfo = 0;
xfree (my_gdb_datadir);
my_gdb_datadir = NULL;
if (sysinfo)
free_syscalls_info ((void *) sysinfo);
}
/* Did we already try to initialize the structure? */
if (have_initialized_sysinfo)
return;
sysinfo = xml_init_syscalls_info (xml_syscall_file);
have_initialized_sysinfo = 1;
if (sysinfo == NULL)
{
if (xml_syscall_file)
warning (_("Could not load the syscall XML file `%s/%s'."),
gdb_datadir, xml_syscall_file);
else
warning (_("There is no XML file to open."));
warning (_("GDB will not be able to display "
"syscall names nor to verify if\n"
"any provided syscall numbers are valid."));
}
/* Saving the data-directory used to read this XML info. */
my_gdb_datadir = xstrdup (gdb_datadir);
}
static int
xml_get_syscall_number (const struct syscalls_info *sysinfo,
const char *syscall_name)
{
struct syscall_desc *sysdesc;
int i;
if (sysinfo == NULL
|| syscall_name == NULL)
return UNKNOWN_SYSCALL;
for (i = 0;
VEC_iterate(syscall_desc_p, sysinfo->syscalls, i, sysdesc);
i++)
if (strcmp (sysdesc->name, syscall_name) == 0)
return sysdesc->number;
return UNKNOWN_SYSCALL;
}
static const char *
xml_get_syscall_name (const struct syscalls_info *sysinfo,
int syscall_number)
{
struct syscall_desc *sysdesc;
int i;
if (sysinfo == NULL
|| syscall_number < 0)
return NULL;
for (i = 0;
VEC_iterate(syscall_desc_p, sysinfo->syscalls, i, sysdesc);
i++)
if (sysdesc->number == syscall_number)
return sysdesc->name;
return NULL;
}
static const char **
xml_list_of_syscalls (const struct syscalls_info *sysinfo)
{
struct syscall_desc *sysdesc;
const char **names = NULL;
int nsyscalls;
int i;
if (sysinfo == NULL)
return NULL;
nsyscalls = VEC_length (syscall_desc_p, sysinfo->syscalls);
names = xmalloc ((nsyscalls + 1) * sizeof (char *));
for (i = 0;
VEC_iterate (syscall_desc_p, sysinfo->syscalls, i, sysdesc);
i++)
names[i] = sysdesc->name;
names[i] = NULL;
return names;
}
void
set_xml_syscall_file_name (const char *name)
{
xml_syscall_file = name;
}
void
get_syscall_by_number (int syscall_number,
struct syscall *s)
{
init_sysinfo ();
s->number = syscall_number;
s->name = xml_get_syscall_name (sysinfo, syscall_number);
}
void
get_syscall_by_name (const char *syscall_name,
struct syscall *s)
{
init_sysinfo ();
s->number = xml_get_syscall_number (sysinfo, syscall_name);
s->name = syscall_name;
}
const char **
get_syscall_names (void)
{
init_sysinfo ();
return xml_list_of_syscalls (sysinfo);
}
#endif /* ! HAVE_LIBEXPAT */