/* XML target description support for GDB.
Copyright (C) 2006-2018 Free Software Foundation, Inc.
Contributed by CodeSourcery.
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 . */
#include "defs.h"
#include "target.h"
#include "target-descriptions.h"
#include "xml-support.h"
#include "xml-tdesc.h"
#include "osabi.h"
#include "filenames.h"
#include
#include
/* Maximum sizes.
This is just to catch obviously wrong values. */
#define MAX_FIELD_SIZE 65536
#define MAX_FIELD_BITSIZE (MAX_FIELD_SIZE * TARGET_CHAR_BIT)
#define MAX_VECTOR_SIZE 65536
#if !defined(HAVE_LIBEXPAT)
/* Parse DOCUMENT into a target description. Or don't, since we don't have
an XML parser. */
static struct target_desc *
tdesc_parse_xml (const char *document, xml_fetch_another fetcher,
void *fetcher_baton)
{
static int have_warned;
if (!have_warned)
{
have_warned = 1;
warning (_("Can not parse XML target description; XML support was "
"disabled at compile time"));
}
return NULL;
}
#else /* HAVE_LIBEXPAT */
/* A record of every XML description we have parsed. We never discard
old descriptions, because we never discard gdbarches. As long as we
have a gdbarch referencing this description, we want to have a copy
of it here, so that if we parse the same XML document again we can
return the same "struct target_desc *"; if they are not singletons,
then we will create unnecessary duplicate gdbarches. See
gdbarch_list_lookup_by_info. */
static std::unordered_map xml_cache;
/* Callback data for target description parsing. */
struct tdesc_parsing_data
{
/* The target description we are building. */
struct target_desc *tdesc;
/* The target feature we are currently parsing, or last parsed. */
struct tdesc_feature *current_feature;
/* The register number to use for the next register we see, if
it does not have its own. This starts at zero. */
int next_regnum;
/* The struct or union we are currently parsing, or last parsed. */
tdesc_type_with_fields *current_type;
/* The byte size of the current struct/flags type, if specified. Zero
if not specified. Flags values must specify a size. */
int current_type_size;
};
/* Handle the end of an element and its value. */
static void
tdesc_end_arch (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, const char *body_text)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
const struct bfd_arch_info *arch;
arch = bfd_scan_arch (body_text);
if (arch == NULL)
gdb_xml_error (parser, _("Target description specified unknown "
"architecture \"%s\""), body_text);
set_tdesc_architecture (data->tdesc, arch);
}
/* Handle the end of an element and its value. */
static void
tdesc_end_osabi (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, const char *body_text)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
enum gdb_osabi osabi;
osabi = osabi_from_tdesc_string (body_text);
if (osabi == GDB_OSABI_UNKNOWN)
warning (_("Target description specified unknown osabi \"%s\""),
body_text);
else
set_tdesc_osabi (data->tdesc, osabi);
}
/* Handle the end of a element and its value. */
static void
tdesc_end_compatible (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, const char *body_text)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
const struct bfd_arch_info *arch;
arch = bfd_scan_arch (body_text);
tdesc_add_compatible (data->tdesc, arch);
}
/* Handle the start of a element. */
static void
tdesc_start_target (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, std::vector &attributes)
{
char *version
= (char *) xml_find_attribute (attributes, "version")->value.get ();
if (strcmp (version, "1.0") != 0)
gdb_xml_error (parser,
_("Target description has unsupported version \"%s\""),
version);
}
/* Handle the start of a element. */
static void
tdesc_start_feature (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, std::vector &attributes)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
char *name = (char *) xml_find_attribute (attributes, "name")->value.get ();
data->current_feature = tdesc_create_feature (data->tdesc, name);
}
/* Handle the start of a element. Fill in the optional
attributes and attach it to the containing feature. */
static void
tdesc_start_reg (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, std::vector &attributes)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
int ix = 0;
char *name, *group;
const char *type;
int bitsize, regnum, save_restore;
int length = attributes.size ();
name = (char *) attributes[ix++].value.get ();
bitsize = * (ULONGEST *) attributes[ix++].value.get ();
if (ix < length && strcmp (attributes[ix].name, "regnum") == 0)
regnum = * (ULONGEST *) attributes[ix++].value.get ();
else
regnum = data->next_regnum;
if (ix < length && strcmp (attributes[ix].name, "type") == 0)
type = (char *) attributes[ix++].value.get ();
else
type = "int";
if (ix < length && strcmp (attributes[ix].name, "group") == 0)
group = (char *) attributes[ix++].value.get ();
else
group = NULL;
if (ix < length && strcmp (attributes[ix].name, "save-restore") == 0)
save_restore = * (ULONGEST *) attributes[ix++].value.get ();
else
save_restore = 1;
if (strcmp (type, "int") != 0
&& strcmp (type, "float") != 0
&& tdesc_named_type (data->current_feature, type) == NULL)
gdb_xml_error (parser, _("Register \"%s\" has unknown type \"%s\""),
name, type);
tdesc_create_reg (data->current_feature, name, regnum, save_restore, group,
bitsize, type);
data->next_regnum = regnum + 1;
}
/* Handle the start of a element. Initialize the type and
record it with the current feature. */
static void
tdesc_start_union (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, std::vector &attributes)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
char *id = (char *) xml_find_attribute (attributes, "id")->value.get ();
data->current_type = tdesc_create_union (data->current_feature, id);
data->current_type_size = 0;
}
/* Handle the start of a element. Initialize the type and
record it with the current feature. */
static void
tdesc_start_struct (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, std::vector &attributes)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
char *id = (char *) xml_find_attribute (attributes, "id")->value.get ();
struct gdb_xml_value *attr;
tdesc_type_with_fields *type_with_fields
= tdesc_create_struct (data->current_feature, id);
data->current_type = type_with_fields;
data->current_type_size = 0;
attr = xml_find_attribute (attributes, "size");
if (attr != NULL)
{
ULONGEST size = * (ULONGEST *) attr->value.get ();
if (size > MAX_FIELD_SIZE)
{
gdb_xml_error (parser,
_("Struct size %s is larger than maximum (%d)"),
pulongest (size), MAX_FIELD_SIZE);
}
tdesc_set_struct_size (type_with_fields, size);
data->current_type_size = size;
}
}
static void
tdesc_start_flags (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, std::vector &attributes)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
char *id = (char *) xml_find_attribute (attributes, "id")->value.get ();
ULONGEST size = * (ULONGEST *)
xml_find_attribute (attributes, "size")->value.get ();
if (size > MAX_FIELD_SIZE)
{
gdb_xml_error (parser,
_("Flags size %s is larger than maximum (%d)"),
pulongest (size), MAX_FIELD_SIZE);
}
data->current_type = tdesc_create_flags (data->current_feature, id, size);
data->current_type_size = size;
}
static void
tdesc_start_enum (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, std::vector &attributes)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
char *id = (char *) xml_find_attribute (attributes, "id")->value.get ();
int size = * (ULONGEST *)
xml_find_attribute (attributes, "size")->value.get ();
if (size > MAX_FIELD_SIZE)
{
gdb_xml_error (parser,
_("Enum size %s is larger than maximum (%d)"),
pulongest (size), MAX_FIELD_SIZE);
}
data->current_type = tdesc_create_enum (data->current_feature, id, size);
data->current_type_size = 0;
}
/* Handle the start of a element. Attach the field to the
current struct, union or flags. */
static void
tdesc_start_field (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, std::vector &attributes)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
struct gdb_xml_value *attr;
struct tdesc_type *field_type;
char *field_name, *field_type_id;
int start, end;
field_name = (char *) xml_find_attribute (attributes, "name")->value.get ();
attr = xml_find_attribute (attributes, "type");
if (attr != NULL)
{
field_type_id = (char *) attr->value.get ();
field_type = tdesc_named_type (data->current_feature, field_type_id);
}
else
{
field_type_id = NULL;
field_type = NULL;
}
attr = xml_find_attribute (attributes, "start");
if (attr != NULL)
{
ULONGEST ul_start = * (ULONGEST *) attr->value.get ();
if (ul_start > MAX_FIELD_BITSIZE)
{
gdb_xml_error (parser,
_("Field start %s is larger than maximum (%d)"),
pulongest (ul_start), MAX_FIELD_BITSIZE);
}
start = ul_start;
}
else
start = -1;
attr = xml_find_attribute (attributes, "end");
if (attr != NULL)
{
ULONGEST ul_end = * (ULONGEST *) attr->value.get ();
if (ul_end > MAX_FIELD_BITSIZE)
{
gdb_xml_error (parser,
_("Field end %s is larger than maximum (%d)"),
pulongest (ul_end), MAX_FIELD_BITSIZE);
}
end = ul_end;
}
else
end = -1;
if (start != -1)
{
tdesc_type_with_fields *t = data->current_type;
/* Older versions of gdb can't handle elided end values.
Stick with that for now, to help ensure backward compatibility.
E.g., If a newer gdbserver is talking to an older gdb. */
if (end == -1)
gdb_xml_error (parser, _("Missing end value"));
if (data->current_type_size == 0)
gdb_xml_error (parser,
_("Bitfields must live in explicitly sized types"));
if (field_type_id != NULL
&& strcmp (field_type_id, "bool") == 0
&& start != end)
{
gdb_xml_error (parser,
_("Boolean fields must be one bit in size"));
}
if (end >= 64)
gdb_xml_error (parser,
_("Bitfield \"%s\" goes past "
"64 bits (unsupported)"),
field_name);
/* Assume that the bit numbering in XML is "lsb-zero". Most
architectures other than PowerPC use this ordering. In the
future, we can add an XML tag to indicate "msb-zero" numbering. */
if (start > end)
gdb_xml_error (parser, _("Bitfield \"%s\" has start after end"),
field_name);
if (end >= data->current_type_size * TARGET_CHAR_BIT)
gdb_xml_error (parser, _("Bitfield \"%s\" does not fit in struct"),
field_name);
if (field_type != NULL)
tdesc_add_typed_bitfield (t, field_name, start, end, field_type);
else if (start == end)
tdesc_add_flag (t, start, field_name);
else
tdesc_add_bitfield (t, field_name, start, end);
}
else if (start == -1 && end != -1)
gdb_xml_error (parser, _("End specified but not start"));
else if (field_type_id != NULL)
{
/* TDESC_TYPE_FLAGS values are explicitly sized, so the following test
catches adding non-bitfield types to flags as well. */
if (data->current_type_size != 0)
gdb_xml_error (parser,
_("Explicitly sized type cannot "
"contain non-bitfield \"%s\""),
field_name);
if (field_type == NULL)
gdb_xml_error (parser, _("Field \"%s\" references undefined "
"type \"%s\""),
field_name, field_type_id);
tdesc_add_field (data->current_type, field_name, field_type);
}
else
gdb_xml_error (parser, _("Field \"%s\" has neither type nor bit position"),
field_name);
}
/* Handle the start of an element. Attach the value to the
current enum. */
static void
tdesc_start_enum_value (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, std::vector &attributes)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
struct gdb_xml_value *attr;
char *field_name;
ULONGEST ul_value;
int value;
field_name = (char *) xml_find_attribute (attributes, "name")->value.get ();
attr = xml_find_attribute (attributes, "value");
ul_value = * (ULONGEST *) attr->value.get ();
if (ul_value > INT_MAX)
{
gdb_xml_error (parser,
_("Enum value %s is larger than maximum (%d)"),
pulongest (ul_value), INT_MAX);
}
value = ul_value;
tdesc_add_enum_value (data->current_type, value, field_name);
}
/* Handle the start of a element. Initialize the type and
record it with the current feature. */
static void
tdesc_start_vector (struct gdb_xml_parser *parser,
const struct gdb_xml_element *element,
void *user_data, std::vector &attributes)
{
struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
struct tdesc_type *field_type;
char *id, *field_type_id;
ULONGEST count;
id = (char *) attributes[0].value.get ();
field_type_id = (char *) attributes[1].value.get ();
count = * (ULONGEST *) attributes[2].value.get ();
if (count > MAX_VECTOR_SIZE)
{
gdb_xml_error (parser,
_("Vector size %s is larger than maximum (%d)"),
pulongest (count), MAX_VECTOR_SIZE);
}
field_type = tdesc_named_type (data->current_feature, field_type_id);
if (field_type == NULL)
gdb_xml_error (parser, _("Vector \"%s\" references undefined type \"%s\""),
id, field_type_id);
tdesc_create_vector (data->current_feature, id, field_type, count);
}
/* The elements and attributes of an XML target description. */
static const struct gdb_xml_attribute field_attributes[] = {
{ "name", GDB_XML_AF_NONE, NULL, NULL },
{ "type", GDB_XML_AF_OPTIONAL, NULL, NULL },
{ "start", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
{ "end", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
static const struct gdb_xml_attribute enum_value_attributes[] = {
{ "name", GDB_XML_AF_NONE, NULL, NULL },
{ "value", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
static const struct gdb_xml_element struct_union_children[] = {
{ "field", field_attributes, NULL, GDB_XML_EF_REPEATABLE,
tdesc_start_field, NULL },
{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};
static const struct gdb_xml_element enum_children[] = {
{ "evalue", enum_value_attributes, NULL, GDB_XML_EF_REPEATABLE,
tdesc_start_enum_value, NULL },
{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};
static const struct gdb_xml_attribute reg_attributes[] = {
{ "name", GDB_XML_AF_NONE, NULL, NULL },
{ "bitsize", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
{ "regnum", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
{ "type", GDB_XML_AF_OPTIONAL, NULL, NULL },
{ "group", GDB_XML_AF_OPTIONAL, NULL, NULL },
{ "save-restore", GDB_XML_AF_OPTIONAL,
gdb_xml_parse_attr_enum, gdb_xml_enums_boolean },
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
static const struct gdb_xml_attribute struct_union_attributes[] = {
{ "id", GDB_XML_AF_NONE, NULL, NULL },
{ "size", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL},
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
static const struct gdb_xml_attribute flags_attributes[] = {
{ "id", GDB_XML_AF_NONE, NULL, NULL },
{ "size", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL},
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
static const struct gdb_xml_attribute enum_attributes[] = {
{ "id", GDB_XML_AF_NONE, NULL, NULL },
{ "size", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL},
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
static const struct gdb_xml_attribute vector_attributes[] = {
{ "id", GDB_XML_AF_NONE, NULL, NULL },
{ "type", GDB_XML_AF_NONE, NULL, NULL },
{ "count", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
static const struct gdb_xml_attribute feature_attributes[] = {
{ "name", GDB_XML_AF_NONE, NULL, NULL },
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
static const struct gdb_xml_element feature_children[] = {
{ "reg", reg_attributes, NULL,
GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
tdesc_start_reg, NULL },
{ "struct", struct_union_attributes, struct_union_children,
GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
tdesc_start_struct, NULL },
{ "union", struct_union_attributes, struct_union_children,
GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
tdesc_start_union, NULL },
{ "flags", flags_attributes, struct_union_children,
GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
tdesc_start_flags, NULL },
{ "enum", enum_attributes, enum_children,
GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
tdesc_start_enum, NULL },
{ "vector", vector_attributes, NULL,
GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
tdesc_start_vector, NULL },
{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};
static const struct gdb_xml_attribute target_attributes[] = {
{ "version", GDB_XML_AF_NONE, NULL, NULL },
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
static const struct gdb_xml_element target_children[] = {
{ "architecture", NULL, NULL, GDB_XML_EF_OPTIONAL,
NULL, tdesc_end_arch },
{ "osabi", NULL, NULL, GDB_XML_EF_OPTIONAL,
NULL, tdesc_end_osabi },
{ "compatible", NULL, NULL, GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
NULL, tdesc_end_compatible },
{ "feature", feature_attributes, feature_children,
GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
tdesc_start_feature, NULL },
{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};
static const struct gdb_xml_element tdesc_elements[] = {
{ "target", target_attributes, target_children, GDB_XML_EF_NONE,
tdesc_start_target, NULL },
{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};
/* Parse DOCUMENT into a target description and return it. */
static struct target_desc *
tdesc_parse_xml (const char *document, xml_fetch_another fetcher,
void *fetcher_baton)
{
struct tdesc_parsing_data data;
/* Expand all XInclude directives. */
std::string expanded_text;
if (!xml_process_xincludes (expanded_text,
_("target description"),
document, fetcher, fetcher_baton, 0))
{
warning (_("Could not load XML target description; ignoring"));
return NULL;
}
/* Check for an exact match in the list of descriptions we have
previously parsed. */
const auto it = xml_cache.find (expanded_text);
if (it != xml_cache.end ())
return it->second;
memset (&data, 0, sizeof (struct tdesc_parsing_data));
data.tdesc = allocate_target_description ();
struct cleanup *result_cleanup
= make_cleanup_free_target_description (data.tdesc);
if (gdb_xml_parse_quick (_("target description"), "gdb-target.dtd",
tdesc_elements, expanded_text.c_str (), &data) == 0)
{
/* Parsed successfully. */
xml_cache.emplace (std::move (expanded_text), data.tdesc);
discard_cleanups (result_cleanup);
return data.tdesc;
}
else
{
warning (_("Could not load XML target description; ignoring"));
do_cleanups (result_cleanup);
return NULL;
}
}
#endif /* HAVE_LIBEXPAT */
/* Read an XML target description from FILENAME. Parse it, and return
the parsed description. */
const struct target_desc *
file_read_description_xml (const char *filename)
{
gdb::optional tdesc_str
= xml_fetch_content_from_file (filename, NULL);
if (!tdesc_str)
{
warning (_("Could not open \"%s\""), filename);
return NULL;
}
return tdesc_parse_xml (tdesc_str->data (), xml_fetch_content_from_file,
(void *) ldirname (filename).c_str ());
}
/* Read a string representation of available features from the target,
using TARGET_OBJECT_AVAILABLE_FEATURES. The returned string is
malloc allocated and NUL-terminated. NAME should be a non-NULL
string identifying the XML document we want; the top level document
is "target.xml". Other calls may be performed for the DTD or
for . */
static gdb::optional
fetch_available_features_from_target (const char *name, void *baton_)
{
struct target_ops *ops = (struct target_ops *) baton_;
/* Read this object as a string. This ensures that a NUL
terminator is added. */
return target_read_stralloc (ops,
TARGET_OBJECT_AVAILABLE_FEATURES,
name);
}
/* Read an XML target description using OPS. Parse it, and return the
parsed description. */
const struct target_desc *
target_read_description_xml (struct target_ops *ops)
{
gdb::optional tdesc_str
= fetch_available_features_from_target ("target.xml", ops);
if (!tdesc_str)
return NULL;
return tdesc_parse_xml (tdesc_str->data (),
fetch_available_features_from_target,
ops);
}
/* Fetches an XML target description using OPS, processing
includes, but not parsing it. Used to dump whole tdesc
as a single XML file. */
gdb::optional
target_fetch_description_xml (struct target_ops *ops)
{
#if !defined(HAVE_LIBEXPAT)
static int have_warned;
if (!have_warned)
{
have_warned = 1;
warning (_("Can not fetch XML target description; XML support was "
"disabled at compile time"));
}
return {};
#else
gdb::optional
tdesc_str = fetch_available_features_from_target ("target.xml", ops);
if (!tdesc_str)
return {};
std::string output;
if (!xml_process_xincludes (output,
_("target description"),
tdesc_str->data (),
fetch_available_features_from_target, ops, 0))
{
warning (_("Could not load XML target description; ignoring"));
return {};
}
return output;
#endif
}