1 /* Helper routines for parsing XML using Expat. 2 3 Copyright (C) 2006-2019 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 21 #ifndef XML_SUPPORT_H 22 #define XML_SUPPORT_H 23 24 #include "gdb_obstack.h" 25 #include "common/vec.h" 26 #include "common/xml-utils.h" 27 #include "common/byte-vector.h" 28 29 struct gdb_xml_parser; 30 struct gdb_xml_element; 31 struct gdb_xml_attribute; 32 33 /* Return an XML document which was compiled into GDB, from 34 the given FILENAME, or NULL if the file was not compiled in. */ 35 36 const char *fetch_xml_builtin (const char *filename); 37 38 /* A to_xfer_partial helper function which reads XML files which were 39 compiled into GDB. The target may call this function from its own 40 to_xfer_partial handler, after converting object and annex to the 41 appropriate filename. */ 42 43 LONGEST xml_builtin_xfer_partial (const char *filename, 44 gdb_byte *readbuf, const gdb_byte *writebuf, 45 ULONGEST offset, LONGEST len); 46 47 /* The text of compiled-in XML documents, from xml-builtin.c 48 (generated). */ 49 50 extern const char *xml_builtin[][2]; 51 52 /* Support for XInclude. */ 53 54 /* Callback to fetch a new XML file, based on the provided HREF. */ 55 56 typedef gdb::optional<gdb::char_vector> (*xml_fetch_another) (const char *href, 57 void *baton); 58 59 /* Append the expansion of TEXT after processing <xi:include> tags in 60 RESULT. FETCHER will be called (with FETCHER_BATON) to retrieve 61 any new files. DEPTH should be zero on the initial call. 62 63 On failure, this function uses NAME in a warning and returns false. 64 It may throw an exception, but does not for XML parsing 65 problems. */ 66 67 bool xml_process_xincludes (std::string &result, 68 const char *name, const char *text, 69 xml_fetch_another fetcher, void *fetcher_baton, 70 int depth); 71 72 /* Simplified XML parser infrastructure. */ 73 74 /* A name and value pair, used to record parsed attributes. */ 75 76 struct gdb_xml_value 77 { 78 gdb_xml_value (const char *name_, void *value_) 79 : name (name_), value (value_) 80 {} 81 82 const char *name; 83 gdb::unique_xmalloc_ptr<void> value; 84 }; 85 86 /* The type of an attribute handler. 87 88 PARSER is the current XML parser, which should be used to issue any 89 debugging or error messages. The second argument is the 90 corresponding attribute description, so that a single handler can 91 be used for multiple attributes; the attribute name is available 92 for error messages and the handler data is available for additional 93 customization (see gdb_xml_parse_attr_enum). VALUE is the string 94 value of the attribute. 95 96 The returned value should be freeable with xfree, and will be freed 97 after the start handler is called. Errors should be reported by 98 calling gdb_xml_error. */ 99 100 typedef void *(gdb_xml_attribute_handler) (struct gdb_xml_parser *parser, 101 const struct gdb_xml_attribute *, 102 const char *value); 103 104 /* Flags for attributes. If no flags are specified, the attribute is 105 required. */ 106 107 enum gdb_xml_attribute_flag 108 { 109 GDB_XML_AF_NONE, 110 GDB_XML_AF_OPTIONAL = 1 << 0, /* The attribute is optional. */ 111 }; 112 113 /* An expected attribute and the handler to call when it is 114 encountered. Arrays of struct gdb_xml_attribute are terminated 115 by an entry with NAME == NULL. */ 116 117 struct gdb_xml_attribute 118 { 119 const char *name; 120 int flags; 121 gdb_xml_attribute_handler *handler; 122 const void *handler_data; 123 }; 124 125 /* Flags for elements. If no flags are specified, the element is 126 required exactly once. */ 127 128 enum gdb_xml_element_flag 129 { 130 GDB_XML_EF_NONE, 131 GDB_XML_EF_OPTIONAL = 1 << 0, /* The element is optional. */ 132 GDB_XML_EF_REPEATABLE = 1 << 1, /* The element is repeatable. */ 133 }; 134 135 /* A handler called at the beginning of an element. 136 137 PARSER is the current XML parser, which should be used to issue any 138 debugging or error messages. ELEMENT is the current element. 139 USER_DATA is the opaque pointer supplied when the parser was 140 created. ATTRIBUTES is a vector of the values of any attributes 141 attached to this element. 142 143 The start handler will only be called if all the required 144 attributes were present and parsed successfully, and elements of 145 ATTRIBUTES are guaranteed to be in the same order used in 146 ELEMENT->ATTRIBUTES (not the order from the XML file). Accordingly 147 fixed offsets can be used to find any non-optional attributes as 148 long as no optional attributes precede them. */ 149 150 typedef void (gdb_xml_element_start_handler) 151 (struct gdb_xml_parser *parser, const struct gdb_xml_element *element, 152 void *user_data, std::vector<gdb_xml_value> &attributes); 153 154 /* A handler called at the end of an element. 155 156 PARSER, ELEMENT, and USER_DATA are as for the start handler. BODY 157 is any accumulated body text inside the element, with leading and 158 trailing whitespace removed. It will never be NULL. */ 159 160 typedef void (gdb_xml_element_end_handler) 161 (struct gdb_xml_parser *, const struct gdb_xml_element *, 162 void *user_data, const char *body_text); 163 164 /* An expected element and the handlers to call when it is 165 encountered. Arrays of struct gdb_xml_element are terminated 166 by an entry with NAME == NULL. */ 167 168 struct gdb_xml_element 169 { 170 const char *name; 171 const struct gdb_xml_attribute *attributes; 172 const struct gdb_xml_element *children; 173 int flags; 174 175 gdb_xml_element_start_handler *start_handler; 176 gdb_xml_element_end_handler *end_handler; 177 }; 178 179 /* Parse a XML document. DOCUMENT is the data to parse, which should 180 be NUL-terminated. If non-NULL, use the compiled-in DTD named 181 DTD_NAME to drive the parsing. 182 183 The return value is 0 for success or -1 for error. It may throw, 184 but only if something unexpected goes wrong during parsing; parse 185 errors will be caught, warned about, and reported as failure. */ 186 187 int gdb_xml_parse_quick (const char *name, const char *dtd_name, 188 const struct gdb_xml_element *elements, 189 const char *document, void *user_data); 190 191 /* Issue a debugging message from one of PARSER's handlers. */ 192 193 void gdb_xml_debug (struct gdb_xml_parser *parser, const char *format, ...) 194 ATTRIBUTE_PRINTF (2, 3); 195 196 /* Issue an error message from one of PARSER's handlers, and stop 197 parsing. */ 198 199 void gdb_xml_error (struct gdb_xml_parser *parser, const char *format, ...) 200 ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (2, 3); 201 202 /* Find the attribute named NAME in the set of parsed attributes 203 ATTRIBUTES. Returns NULL if not found. */ 204 205 struct gdb_xml_value *xml_find_attribute 206 (std::vector<gdb_xml_value> &attributes, const char *name); 207 208 /* Parse an integer attribute into a ULONGEST. */ 209 210 extern gdb_xml_attribute_handler gdb_xml_parse_attr_ulongest; 211 212 /* Map NAME to VALUE. A struct gdb_xml_enum * should be saved as the 213 value of handler_data when using gdb_xml_parse_attr_enum to parse a 214 fixed list of possible strings. The list is terminated by an entry 215 with NAME == NULL. */ 216 217 struct gdb_xml_enum 218 { 219 const char *name; 220 ULONGEST value; 221 }; 222 223 /* A handler_data for yes/no boolean values. */ 224 extern const struct gdb_xml_enum gdb_xml_enums_boolean[]; 225 226 extern gdb_xml_attribute_handler gdb_xml_parse_attr_enum; 227 228 /* Parse an integer string into a ULONGEST and return it, or call 229 gdb_xml_error if it could not be parsed. */ 230 231 ULONGEST gdb_xml_parse_ulongest (struct gdb_xml_parser *parser, 232 const char *value); 233 234 /* Open FILENAME, read all its text into memory, close it, and return 235 the text. If something goes wrong, return an uninstantiated optional 236 and warn. */ 237 238 extern gdb::optional<gdb::char_vector> xml_fetch_content_from_file 239 (const char *filename, void *baton); 240 241 #endif 242