binutils-gdb/gdb/xml-syscall.c

652 lines
16 KiB
C

/* Functions that provide the mechanism to parse a syscall XML file
and get its values.
Copyright (C) 2009-2017 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"
#include "gdbarch.h"
/* For the struct syscall definition. */
#include "target.h"
#include "filenames.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 (struct gdbarch *gdbarch, const char *name)
{
return;
}
void
get_syscall_by_number (struct gdbarch *gdbarch,
int syscall_number, struct syscall *s)
{
syscall_warn_user ();
s->number = syscall_number;
s->name = NULL;
}
void
get_syscall_by_name (struct gdbarch *gdbarch, const char *syscall_name,
struct syscall *s)
{
syscall_warn_user ();
s->number = UNKNOWN_SYSCALL;
s->name = syscall_name;
}
const char **
get_syscall_names (struct gdbarch *gdbarch)
{
syscall_warn_user ();
return NULL;
}
struct syscall *
get_syscalls_by_group (struct gdbarch *gdbarch, const char *group)
{
syscall_warn_user ();
return NULL;
}
const char **
get_syscall_group_names (struct gdbarch *gdbarch)
{
syscall_warn_user ();
return NULL;
}
#else /* ! HAVE_LIBEXPAT */
/* 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 of a syscall group. */
typedef struct syscall_group_desc
{
/* The group name. */
char *name;
/* The syscalls that are part of the group. */
VEC(syscall_desc_p) *syscalls;
} *syscall_group_desc_p;
DEF_VEC_P(syscall_group_desc_p);
/* Structure that represents syscalls information. */
struct syscalls_info
{
/* The syscalls. */
VEC(syscall_desc_p) *syscalls;
/* The syscall groups. */
VEC(syscall_group_desc_p) *groups;
/* 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. */
char *my_gdb_datadir;
};
/* Callback data for syscall information parsing. */
struct syscall_parsing_data
{
/* The syscalls_info we are building. */
struct syscalls_info *syscalls_info;
};
static struct syscalls_info *
allocate_syscalls_info (void)
{
return XCNEW (struct syscalls_info);
}
static void
syscalls_info_free_syscalls_desc (struct syscall_desc *sd)
{
xfree (sd->name);
}
/* Free syscall_group_desc members but not the structure itself. */
static void
syscalls_info_free_syscall_group_desc (struct syscall_group_desc *sd)
{
VEC_free (syscall_desc_p, sd->syscalls);
xfree (sd->name);
}
static void
free_syscalls_info (void *arg)
{
struct syscalls_info *syscalls_info = (struct syscalls_info *) arg;
struct syscall_desc *sysdesc;
struct syscall_group_desc *groupdesc;
int i;
xfree (syscalls_info->my_gdb_datadir);
if (syscalls_info->syscalls != NULL)
{
for (i = 0;
VEC_iterate (syscall_desc_p, syscalls_info->syscalls, i, sysdesc);
i++)
syscalls_info_free_syscalls_desc (sysdesc);
VEC_free (syscall_desc_p, syscalls_info->syscalls);
}
if (syscalls_info->groups != NULL)
{
for (i = 0;
VEC_iterate (syscall_group_desc_p,
syscalls_info->groups, i, groupdesc);
i++)
syscalls_info_free_syscall_group_desc (groupdesc);
VEC_free (syscall_group_desc_p, syscalls_info->groups);
}
xfree (syscalls_info);
}
static struct cleanup *
make_cleanup_free_syscalls_info (struct syscalls_info *syscalls_info)
{
return make_cleanup (free_syscalls_info, syscalls_info);
}
/* Create a new syscall group. Return pointer to the
syscall_group_desc structure that represents the new group. */
static struct syscall_group_desc *
syscall_group_create_syscall_group_desc (struct syscalls_info *syscalls_info,
const char *group)
{
struct syscall_group_desc *groupdesc = XCNEW (struct syscall_group_desc);
groupdesc->name = xstrdup (group);
VEC_safe_push (syscall_group_desc_p, syscalls_info->groups, groupdesc);
return groupdesc;
}
/* Add a syscall to the group. If group doesn't exist, create it. */
static void
syscall_group_add_syscall (struct syscalls_info *syscalls_info,
struct syscall_desc *syscall,
const char *group)
{
struct syscall_group_desc *groupdesc = NULL;
int i;
/* Search for an existing group. */
for (i = 0;
VEC_iterate (syscall_group_desc_p, syscalls_info->groups, i, groupdesc);
i++)
{
if (strcmp (groupdesc->name, group) == 0)
break;
}
if (groupdesc == NULL)
{
/* No group was found with this name. We must create a new
one. */
groupdesc = syscall_group_create_syscall_group_desc (syscalls_info,
group);
}
VEC_safe_push (syscall_desc_p, groupdesc->syscalls, syscall);
}
static void
syscall_create_syscall_desc (struct syscalls_info *syscalls_info,
const char *name, int number,
char *groups)
{
struct syscall_desc *sysdesc = XCNEW (struct syscall_desc);
char *group;
sysdesc->name = xstrdup (name);
sysdesc->number = number;
VEC_safe_push (syscall_desc_p, syscalls_info->syscalls, sysdesc);
/* Add syscall to its groups. */
if (groups != NULL)
{
for (group = strtok (groups, ",");
group != NULL;
group = strtok (NULL, ","))
syscall_group_add_syscall (syscalls_info, sysdesc, group);
}
}
/* 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 = (struct syscall_parsing_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;
char *groups = NULL;
len = VEC_length (gdb_xml_value_s, attributes);
for (i = 0; i < len; i++)
{
if (strcmp (attrs[i].name, "name") == 0)
name = (char *) attrs[i].value;
else if (strcmp (attrs[i].name, "number") == 0)
number = * (ULONGEST *) attrs[i].value;
else if (strcmp (attrs[i].name, "groups") == 0)
groups = (char *) attrs[i].value;
else
internal_error (__FILE__, __LINE__,
_("Unknown attribute name '%s'."), attrs[i].name);
}
gdb_assert (name);
syscall_create_syscall_desc (data->syscalls_info, name, number, groups);
}
/* 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 },
{ "groups", GDB_XML_AF_OPTIONAL, 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.syscalls_info = allocate_syscalls_info ();
result_cleanup = make_cleanup_free_syscalls_info (data.syscalls_info);
if (gdb_xml_parse_quick (_("syscalls info"), NULL,
syselements, document, &data) == 0)
{
/* Parsed successfully. */
discard_cleanups (result_cleanup);
return data.syscalls_info;
}
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 struct syscalls_info *
xml_init_syscalls_info (const char *filename)
{
char *full_file;
struct syscalls_info *syscalls_info;
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);
syscalls_info = syscall_parse_xml (full_file,
xml_fetch_content_from_file,
(void *) ldirname (filename).c_str ());
do_cleanups (back_to);
return syscalls_info;
}
/* Initializes the syscalls_info structure according to the
architecture. */
static void
init_syscalls_info (struct gdbarch *gdbarch)
{
struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
const char *xml_syscall_file = gdbarch_xml_syscall_file (gdbarch);
/* Should we re-read the XML info for this target? */
if (syscalls_info != NULL && syscalls_info->my_gdb_datadir != NULL
&& filename_cmp (syscalls_info->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. */
free_syscalls_info (syscalls_info);
syscalls_info = NULL;
set_gdbarch_syscalls_info (gdbarch, NULL);
}
/* Did we succeed at initializing this? */
if (syscalls_info != NULL)
return;
syscalls_info = xml_init_syscalls_info (xml_syscall_file);
/* If there was some error reading the XML file, we initialize
gdbarch->syscalls_info anyway, in order to store information
about our attempt. */
if (syscalls_info == NULL)
syscalls_info = allocate_syscalls_info ();
if (syscalls_info->syscalls == NULL)
{
if (xml_syscall_file != NULL)
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. */
syscalls_info->my_gdb_datadir = xstrdup (gdb_datadir);
set_gdbarch_syscalls_info (gdbarch, syscalls_info);
}
/* Search for a syscall group by its name. Return syscall_group_desc
structure for the group if found or NULL otherwise. */
static struct syscall_group_desc *
syscall_group_get_group_by_name (const struct syscalls_info *syscalls_info,
const char *group)
{
struct syscall_group_desc *groupdesc;
int i;
if (syscalls_info == NULL)
return NULL;
if (group == NULL)
return NULL;
/* Search for existing group. */
for (i = 0;
VEC_iterate (syscall_group_desc_p, syscalls_info->groups, i, groupdesc);
i++)
{
if (strcmp (groupdesc->name, group) == 0)
return groupdesc;
}
return NULL;
}
static int
xml_get_syscall_number (struct gdbarch *gdbarch,
const char *syscall_name)
{
struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
struct syscall_desc *sysdesc;
int i;
if (syscalls_info == NULL
|| syscall_name == NULL)
return UNKNOWN_SYSCALL;
for (i = 0;
VEC_iterate(syscall_desc_p, syscalls_info->syscalls, i, sysdesc);
i++)
if (strcmp (sysdesc->name, syscall_name) == 0)
return sysdesc->number;
return UNKNOWN_SYSCALL;
}
static const char *
xml_get_syscall_name (struct gdbarch *gdbarch,
int syscall_number)
{
struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
struct syscall_desc *sysdesc;
int i;
if (syscalls_info == NULL
|| syscall_number < 0)
return NULL;
for (i = 0;
VEC_iterate(syscall_desc_p, syscalls_info->syscalls, i, sysdesc);
i++)
if (sysdesc->number == syscall_number)
return sysdesc->name;
return NULL;
}
static const char **
xml_list_of_syscalls (struct gdbarch *gdbarch)
{
struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
struct syscall_desc *sysdesc;
const char **names = NULL;
int nsyscalls;
int i;
if (syscalls_info == NULL)
return NULL;
nsyscalls = VEC_length (syscall_desc_p, syscalls_info->syscalls);
names = XNEWVEC (const char *, nsyscalls + 1);
for (i = 0;
VEC_iterate (syscall_desc_p, syscalls_info->syscalls, i, sysdesc);
i++)
names[i] = sysdesc->name;
names[i] = NULL;
return names;
}
/* Iterate over the syscall_group_desc element to return a list of
syscalls that are part of the given group, terminated by an empty
element. If the syscall group doesn't exist, return NULL. */
static struct syscall *
xml_list_syscalls_by_group (struct gdbarch *gdbarch, const char *group)
{
struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
struct syscall_group_desc *groupdesc;
struct syscall_desc *sysdesc;
struct syscall *syscalls = NULL;
int nsyscalls;
int i;
if (syscalls_info == NULL)
return NULL;
groupdesc = syscall_group_get_group_by_name (syscalls_info, group);
if (groupdesc == NULL)
return NULL;
nsyscalls = VEC_length (syscall_desc_p, groupdesc->syscalls);
syscalls = (struct syscall*) xmalloc ((nsyscalls + 1)
* sizeof (struct syscall));
for (i = 0;
VEC_iterate (syscall_desc_p, groupdesc->syscalls, i, sysdesc);
i++)
{
syscalls[i].name = sysdesc->name;
syscalls[i].number = sysdesc->number;
}
/* Add final element marker. */
syscalls[i].name = NULL;
syscalls[i].number = 0;
return syscalls;
}
/* Return a NULL terminated list of syscall groups or an empty list, if
no syscall group is available. Return NULL, if there is no syscall
information available. */
static const char **
xml_list_of_groups (struct gdbarch *gdbarch)
{
struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
struct syscall_group_desc *groupdesc;
const char **names = NULL;
int i;
int ngroups;
if (syscalls_info == NULL)
return NULL;
ngroups = VEC_length (syscall_group_desc_p, syscalls_info->groups);
names = (const char**) xmalloc ((ngroups + 1) * sizeof (char *));
for (i = 0;
VEC_iterate (syscall_group_desc_p, syscalls_info->groups, i, groupdesc);
i++)
names[i] = groupdesc->name;
names[i] = NULL;
return names;
}
void
set_xml_syscall_file_name (struct gdbarch *gdbarch, const char *name)
{
set_gdbarch_xml_syscall_file (gdbarch, name);
}
void
get_syscall_by_number (struct gdbarch *gdbarch,
int syscall_number, struct syscall *s)
{
init_syscalls_info (gdbarch);
s->number = syscall_number;
s->name = xml_get_syscall_name (gdbarch, syscall_number);
}
void
get_syscall_by_name (struct gdbarch *gdbarch,
const char *syscall_name, struct syscall *s)
{
init_syscalls_info (gdbarch);
s->number = xml_get_syscall_number (gdbarch, syscall_name);
s->name = syscall_name;
}
const char **
get_syscall_names (struct gdbarch *gdbarch)
{
init_syscalls_info (gdbarch);
return xml_list_of_syscalls (gdbarch);
}
/* See comment in xml-syscall.h. */
struct syscall *
get_syscalls_by_group (struct gdbarch *gdbarch, const char *group)
{
init_syscalls_info (gdbarch);
return xml_list_syscalls_by_group (gdbarch, group);
}
/* See comment in xml-syscall.h. */
const char **
get_syscall_group_names (struct gdbarch *gdbarch)
{
init_syscalls_info (gdbarch);
return xml_list_of_groups (gdbarch);
}
#endif /* ! HAVE_LIBEXPAT */