binutils-gdb/gdb/xml-syscall.c

567 lines
14 KiB
C

/* Functions that provide the mechanism to parse a syscall XML file
and get its values.
Copyright (C) 2009-2018 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. */
struct syscall_desc
{
syscall_desc (int number_, std::string name_)
: number (number_), name (name_)
{}
/* The syscall number. */
int number;
/* The syscall name. */
std::string name;
};
typedef std::unique_ptr<syscall_desc> syscall_desc_up;
/* Structure of a syscall group. */
struct syscall_group_desc
{
syscall_group_desc (const std::string &name_)
: name (name_)
{}
/* The group name. */
std::string name;
/* The syscalls that are part of the group. This is a non-owning
reference. */
std::vector<syscall_desc *> syscalls;
};
typedef std::unique_ptr<syscall_group_desc> syscall_group_desc_up;
/* Structure that represents syscalls information. */
struct syscalls_info
{
/* The syscalls. */
std::vector<syscall_desc_up> syscalls;
/* The syscall groups. */
std::vector<syscall_group_desc_up> 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. */
std::string my_gdb_datadir;
};
typedef std::unique_ptr<syscalls_info> syscalls_info_up;
/* Callback data for syscall information parsing. */
struct syscall_parsing_data
{
/* The syscalls_info we are building. */
struct 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)
{
syscall_group_desc *groupdesc = new syscall_group_desc (group);
syscalls_info->groups.emplace_back (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)
{
/* Search for an existing group. */
std::vector<syscall_group_desc_up>::iterator it
= syscalls_info->groups.begin ();
for (; it != syscalls_info->groups.end (); it++)
{
if ((*it)->name == group)
break;
}
syscall_group_desc *groupdesc;
if (it != syscalls_info->groups.end ())
groupdesc = it->get ();
else
{
/* No group was found with this name. We must create a new
one. */
groupdesc = syscall_group_create_syscall_group_desc (syscalls_info,
group);
}
groupdesc->syscalls.push_back (syscall);
}
static void
syscall_create_syscall_desc (struct syscalls_info *syscalls_info,
const char *name, int number,
char *groups)
{
syscall_desc *sysdesc = new syscall_desc (number, name);
syscalls_info->syscalls.emplace_back (sysdesc);
/* Add syscall to its groups. */
if (groups != NULL)
{
for (char *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 syscall_parsing_data data;
syscalls_info_up sysinfo (new syscalls_info ());
data.syscalls_info = sysinfo.get ();
if (gdb_xml_parse_quick (_("syscalls info"), NULL,
syselements, document, &data) == 0)
{
/* Parsed successfully. */
return sysinfo.release ();
}
else
{
warning (_("Could not load XML syscalls info; ignoring"));
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)
{
gdb::unique_xmalloc_ptr<char> full_file
= xml_fetch_content_from_file (filename, gdb_datadir);
if (full_file == NULL)
return NULL;
return syscall_parse_xml (full_file.get (),
xml_fetch_content_from_file,
(void *) ldirname (filename).c_str ());
}
/* 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.empty ()
&& filename_cmp (syscalls_info->my_gdb_datadir.c_str (),
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. */
delete 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 = new struct syscalls_info ();
if (syscalls_info->syscalls.empty ())
{
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.assign (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)
{
if (syscalls_info == NULL)
return NULL;
if (group == NULL)
return NULL;
/* Search for existing group. */
for (const syscall_group_desc_up &groupdesc : syscalls_info->groups)
{
if (groupdesc->name == group)
return groupdesc.get ();
}
return NULL;
}
static int
xml_get_syscall_number (struct gdbarch *gdbarch,
const char *syscall_name)
{
struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
if (syscalls_info == NULL
|| syscall_name == NULL)
return UNKNOWN_SYSCALL;
for (const syscall_desc_up &sysdesc : syscalls_info->syscalls)
if (sysdesc->name == syscall_name)
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);
if (syscalls_info == NULL
|| syscall_number < 0)
return NULL;
for (const syscall_desc_up &sysdesc : syscalls_info->syscalls)
if (sysdesc->number == syscall_number)
return sysdesc->name.c_str ();
return NULL;
}
static const char **
xml_list_of_syscalls (struct gdbarch *gdbarch)
{
struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch);
if (syscalls_info == NULL)
return NULL;
int nsyscalls = syscalls_info->syscalls.size ();
const char **names = XNEWVEC (const char *, nsyscalls + 1);
int i;
for (i = 0; i < syscalls_info->syscalls.size (); i++)
names[i] = syscalls_info->syscalls[i]->name.c_str ();
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 *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 = groupdesc->syscalls.size ();
syscalls = (struct syscall*) xmalloc ((nsyscalls + 1)
* sizeof (struct syscall));
for (i = 0; i < groupdesc->syscalls.size (); i++)
{
syscalls[i].name = groupdesc->syscalls[i]->name.c_str ();
syscalls[i].number = groupdesc->syscalls[i]->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);
const char **names = NULL;
int ngroups;
int i;
if (syscalls_info == NULL)
return NULL;
ngroups = syscalls_info->groups.size ();
names = (const char**) xmalloc ((ngroups + 1) * sizeof (char *));
for (i = 0; i < syscalls_info->groups.size (); i++)
names[i] = syscalls_info->groups[i]->name.c_str ();
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 */