/* XML target description support for GDB. Copyright (C) 2006-2023 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) { 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) { struct tdesc_parsing_data data; /* Expand all XInclude directives. */ std::string expanded_text; if (!xml_process_xincludes (expanded_text, _("target description"), document, fetcher, 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.get (); memset (&data, 0, sizeof (struct tdesc_parsing_data)); target_desc_up description = allocate_target_description (); data.tdesc = description.get (); 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), std::move (description)); return data.tdesc; } else { warning (_("Could not load XML target description; ignoring")); 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; } const std::string dirname = ldirname (filename); auto fetch_another = [&dirname] (const char *name) { return xml_fetch_content_from_file (name, dirname.c_str ()); }; return tdesc_parse_xml (tdesc_str->data (), fetch_another); } /* 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, target_ops *ops) { /* 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; auto fetch_another = [ops] (const char *name) { return fetch_available_features_from_target (name, ops); }; return tdesc_parse_xml (tdesc_str->data (), fetch_another); } /* 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 {}; auto fetch_another = [ops] (const char *name) { return fetch_available_features_from_target (name, ops); }; std::string output; if (!xml_process_xincludes (output, _("target description"), tdesc_str->data (), fetch_another, 0)) { warning (_("Could not load XML target description; ignoring")); return {}; } return output; #endif } /* See xml-tdesc.h. */ const struct target_desc * string_read_description_xml (const char *xml) { return tdesc_parse_xml (xml, [] (const char *href) { error (_("xincludes are unsupported with this method")); return gdb::optional (); }); }