/* Helper routines for parsing XML using Expat.
- Copyright (C) 2006
- Free Software Foundation, Inc.
+ Copyright (C) 2006, 2007 Free Software Foundation, Inc.
This file is part of GDB.
#include "defs.h"
#include "gdbcmd.h"
+#include "exceptions.h"
+#include "xml-support.h"
+
+#include "gdb_string.h"
+#include "safe-ctype.h"
/* Debugging flag. */
static int debug_xml;
available. */
#ifdef HAVE_LIBEXPAT
-#include "exceptions.h"
-#include "xml-support.h"
-
#include "gdb_expat.h"
-#include "gdb_string.h"
-#include "safe-ctype.h"
+
+/* The maximum depth of <xi:include> nesting. No need to be miserly,
+ we just want to avoid running out of stack on loops. */
+#define MAX_XINCLUDE_DEPTH 30
+
+/* Simplified XML parser infrastructure. */
/* A parsing level -- used to keep track of the current element
nesting. */
struct gdb_exception error; /* A thrown error, if any. */
int last_line; /* The line of the thrown error, or 0. */
+
+ const char *dtd_name; /* The name of the expected / default DTD,
+ if specified. */
+ int is_xinclude; /* Are we the special <xi:include> parser? */
};
/* Process some body text. We accumulate the text for later use; it's
const XML_Char **attrs)
{
struct gdb_xml_parser *parser = data;
- struct scope_level *scope = VEC_last (scope_level_s, parser->scopes);
+ struct scope_level *scope;
struct scope_level new_scope;
const struct gdb_xml_element *element;
const struct gdb_xml_attribute *attribute;
unsigned int seen;
struct cleanup *back_to;
- back_to = make_cleanup (gdb_xml_values_cleanup, &attributes);
-
/* Push an error scope. If we return or throw an exception before
filling this in, it will tell us to ignore children of this
element. */
+ VEC_reserve (scope_level_s, parser->scopes, 1);
+ scope = VEC_last (scope_level_s, parser->scopes);
memset (&new_scope, 0, sizeof (new_scope));
- VEC_safe_push (scope_level_s, parser->scopes, &new_scope);
+ VEC_quick_push (scope_level_s, parser->scopes, &new_scope);
gdb_xml_debug (parser, _("Entering element <%s>"), name);
if (element == NULL || element->name == NULL)
{
+ /* If we're working on XInclude, <xi:include> can be the child
+ of absolutely anything. Copy the previous scope's element
+ list into the new scope even if there was no match. */
+ if (parser->is_xinclude)
+ {
+ struct scope_level *unknown_scope;
+
+ XML_DefaultCurrent (parser->expat_parser);
+
+ unknown_scope = VEC_last (scope_level_s, parser->scopes);
+ unknown_scope->elements = scope->elements;
+ return;
+ }
+
gdb_xml_debug (parser, _("Element <%s> unknown"), name);
- do_cleanups (back_to);
return;
}
scope->seen |= seen;
+ back_to = make_cleanup (gdb_xml_values_cleanup, &attributes);
+
for (attribute = element->attributes;
attribute != NULL && attribute->name != NULL;
attribute++)
struct scope_level *scope = VEC_last (scope_level_s, parser->scopes);
const struct gdb_xml_element *element;
unsigned int seen;
- char *body;
gdb_xml_debug (parser, _("Leaving element <%s>"), name);
element->name);
/* Call the element processor. */
- if (scope->body == NULL)
- body = "";
- else
+ if (scope->element != NULL && scope->element->end_handler)
{
- int length;
+ char *body;
- length = obstack_object_size (scope->body);
- obstack_1grow (scope->body, '\0');
- body = obstack_finish (scope->body);
+ if (scope->body == NULL)
+ body = "";
+ else
+ {
+ int length;
- /* Strip leading and trailing whitespace. */
- while (length > 0 && ISSPACE (body[length-1]))
- body[--length] = '\0';
- while (*body && ISSPACE (*body))
- body++;
- }
+ length = obstack_object_size (scope->body);
+ obstack_1grow (scope->body, '\0');
+ body = obstack_finish (scope->body);
- if (scope->element != NULL && scope->element->end_handler)
- scope->element->end_handler (parser, scope->element, parser->user_data,
- body);
+ /* Strip leading and trailing whitespace. */
+ while (length > 0 && ISSPACE (body[length-1]))
+ body[--length] = '\0';
+ while (*body && ISSPACE (*body))
+ body++;
+ }
+
+ scope->element->end_handler (parser, scope->element, parser->user_data,
+ body);
+ }
+ else if (scope->element == NULL)
+ XML_DefaultCurrent (parser->expat_parser);
/* Pop the scope level. */
if (scope->body)
return parser;
}
+/* External entity handler. The only external entities we support
+ are those compiled into GDB (we do not fetch entities from the
+ target). */
+
+static int XMLCALL
+gdb_xml_fetch_external_entity (XML_Parser expat_parser,
+ const XML_Char *context,
+ const XML_Char *base,
+ const XML_Char *systemId,
+ const XML_Char *publicId)
+{
+ struct gdb_xml_parser *parser = XML_GetUserData (expat_parser);
+ XML_Parser entity_parser;
+ const char *text;
+ enum XML_Status status;
+
+ if (systemId == NULL)
+ {
+ text = fetch_xml_builtin (parser->dtd_name);
+ if (text == NULL)
+ internal_error (__FILE__, __LINE__, "could not locate built-in DTD %s",
+ parser->dtd_name);
+ }
+ else
+ {
+ text = fetch_xml_builtin (systemId);
+ if (text == NULL)
+ return XML_STATUS_ERROR;
+ }
+
+ entity_parser = XML_ExternalEntityParserCreate (expat_parser, context, NULL);
+
+ /* Don't use our handlers for the contents of the DTD. Just let expat
+ process it. */
+ XML_SetElementHandler (entity_parser, NULL, NULL);
+ XML_SetDoctypeDeclHandler (entity_parser, NULL, NULL);
+ XML_SetXmlDeclHandler (entity_parser, NULL);
+ XML_SetDefaultHandler (entity_parser, NULL);
+ XML_SetUserData (entity_parser, NULL);
+
+ status = XML_Parse (entity_parser, text, strlen (text), 1);
+
+ XML_ParserFree (entity_parser);
+ return status;
+}
+
+/* Associate DTD_NAME, which must be the name of a compiled-in DTD,
+ with PARSER. */
+
+void
+gdb_xml_use_dtd (struct gdb_xml_parser *parser, const char *dtd_name)
+{
+ enum XML_Error err;
+
+ parser->dtd_name = dtd_name;
+
+ XML_SetParamEntityParsing (parser->expat_parser,
+ XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE);
+ XML_SetExternalEntityRefHandler (parser->expat_parser,
+ gdb_xml_fetch_external_entity);
+
+ /* Even if no DTD is provided, use the built-in DTD anyway. */
+ err = XML_UseForeignDTD (parser->expat_parser, XML_TRUE);
+ if (err != XML_ERROR_NONE)
+ internal_error (__FILE__, __LINE__,
+ "XML_UseForeignDTD failed: %s", XML_ErrorString (err));
+}
+
/* Invoke PARSER on BUFFER. BUFFER is the data to parse, which
should be NUL-terminated.
return ret;
}
+/* A handler_data for yes/no boolean values. */
+
+const struct gdb_xml_enum gdb_xml_enums_boolean[] = {
+ { "yes", 1 },
+ { "no", 0 },
+ { NULL, 0 }
+};
+
/* Map NAME to VALUE. A struct gdb_xml_enum * should be saved as the
value of handler_data when using gdb_xml_parse_attr_enum to parse a
fixed list of possible strings. The list is terminated by an entry
void *ret;
for (enums = attribute->handler_data; enums->name != NULL; enums++)
- if (strcmp (enums->name, value) == 0)
+ if (strcasecmp (enums->name, value) == 0)
break;
if (enums->name == NULL)
memcpy (ret, &enums->value, sizeof (enums->value));
return ret;
}
+\f
+
+/* XInclude processing. This is done as a separate step from actually
+ parsing the document, so that we can produce a single combined XML
+ document - e.g. to hand to a front end or to simplify comparing two
+ documents. We make extensive use of XML_DefaultCurrent, to pass
+ input text directly into the output without reformatting or
+ requoting it.
+
+ We output the DOCTYPE declaration for the first document unchanged,
+ if present, and discard DOCTYPEs from included documents. Only the
+ one we pass through here is used when we feed the result back to
+ expat. The XInclude standard explicitly does not discuss
+ validation of the result; we choose to apply the same DTD applied
+ to the outermost document.
+
+ We can not simply include the external DTD subset in the document
+ as an internal subset, because <!IGNORE> and <!INCLUDE> are valid
+ only in external subsets. But if we do not pass the DTD into the
+ output at all, default values will not be filled in.
+
+ We don't pass through any <?xml> declaration because we generate
+ UTF-8, not whatever the input encoding was. */
+
+struct xinclude_parsing_data
+{
+ /* The obstack to build the output in. */
+ struct obstack obstack;
+
+ /* A count indicating whether we are in an element whose
+ children should not be copied to the output, and if so,
+ how deep we are nested. This is used for anything inside
+ an xi:include, and for the DTD. */
+ int skip_depth;
+
+ /* The number of <xi:include> elements currently being processed,
+ to detect loops. */
+ int include_depth;
+
+ /* A function to call to obtain additional features, and its
+ baton. */
+ xml_fetch_another fetcher;
+ void *fetcher_baton;
+};
+
+static void
+xinclude_start_include (struct gdb_xml_parser *parser,
+ const struct gdb_xml_element *element,
+ void *user_data, VEC(gdb_xml_value_s) *attributes)
+{
+ struct xinclude_parsing_data *data = user_data;
+ char *href = VEC_index (gdb_xml_value_s, attributes, 0)->value;
+ struct cleanup *back_to;
+ char *text, *output;
+ int ret;
+
+ gdb_xml_debug (parser, _("Processing XInclude of \"%s\""), href);
+
+ if (data->include_depth > MAX_XINCLUDE_DEPTH)
+ gdb_xml_error (parser, _("Maximum XInclude depth (%d) exceeded"),
+ MAX_XINCLUDE_DEPTH);
+
+ text = data->fetcher (href, data->fetcher_baton);
+ if (text == NULL)
+ gdb_xml_error (parser, _("Could not load XML document \"%s\""), href);
+ back_to = make_cleanup (xfree, text);
+
+ output = xml_process_xincludes (parser->name, text, data->fetcher,
+ data->fetcher_baton,
+ data->include_depth + 1);
+ if (output == NULL)
+ gdb_xml_error (parser, _("Parsing \"%s\" failed"), href);
+
+ obstack_grow (&data->obstack, output, strlen (output));
+ xfree (output);
+ do_cleanups (back_to);
+
+ data->skip_depth++;
+}
+
+static void
+xinclude_end_include (struct gdb_xml_parser *parser,
+ const struct gdb_xml_element *element,
+ void *user_data, const char *body_text)
+{
+ struct xinclude_parsing_data *data = user_data;
+
+ data->skip_depth--;
+}
+
+static void XMLCALL
+xml_xinclude_default (void *data_, const XML_Char *s, int len)
+{
+ struct gdb_xml_parser *parser = data_;
+ struct xinclude_parsing_data *data = parser->user_data;
+
+ /* If we are inside of e.g. xi:include or the DTD, don't save this
+ string. */
+ if (data->skip_depth)
+ return;
+
+ /* Otherwise just add it to the end of the document we're building
+ up. */
+ obstack_grow (&data->obstack, s, len);
+}
+
+static void XMLCALL
+xml_xinclude_start_doctype (void *data_, const XML_Char *doctypeName,
+ const XML_Char *sysid, const XML_Char *pubid,
+ int has_internal_subset)
+{
+ struct gdb_xml_parser *parser = data_;
+ struct xinclude_parsing_data *data = parser->user_data;
+
+ /* Don't print out the doctype, or the contents of the DTD internal
+ subset, if any. */
+ data->skip_depth++;
+}
+
+static void XMLCALL
+xml_xinclude_end_doctype (void *data_)
+{
+ struct gdb_xml_parser *parser = data_;
+ struct xinclude_parsing_data *data = parser->user_data;
+
+ data->skip_depth--;
+}
+
+static void XMLCALL
+xml_xinclude_xml_decl (void *data_, const XML_Char *version,
+ const XML_Char *encoding, int standalone)
+{
+ /* Do nothing - this function prevents the default handler from
+ being called, thus suppressing the XML declaration from the
+ output. */
+}
+
+static void
+xml_xinclude_cleanup (void *data_)
+{
+ struct xinclude_parsing_data *data = data_;
+
+ obstack_free (&data->obstack, NULL);
+ xfree (data);
+}
+
+const struct gdb_xml_attribute xinclude_attributes[] = {
+ { "href", GDB_XML_AF_NONE, NULL, NULL },
+ { NULL, GDB_XML_AF_NONE, NULL, NULL }
+};
+
+const struct gdb_xml_element xinclude_elements[] = {
+ { "http://www.w3.org/2001/XInclude!include", xinclude_attributes, NULL,
+ GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
+ xinclude_start_include, xinclude_end_include },
+ { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
+};
+
+/* The main entry point for <xi:include> processing. */
+
+char *
+xml_process_xincludes (const char *name, const char *text,
+ xml_fetch_another fetcher, void *fetcher_baton,
+ int depth)
+{
+ enum XML_Error err;
+ struct gdb_xml_parser *parser;
+ struct xinclude_parsing_data *data;
+ struct cleanup *back_to;
+ char *result = NULL;
+
+ data = XZALLOC (struct xinclude_parsing_data);
+ obstack_init (&data->obstack);
+ back_to = make_cleanup (xml_xinclude_cleanup, data);
+
+ parser = gdb_xml_create_parser_and_cleanup (name, xinclude_elements, data);
+ parser->is_xinclude = 1;
+
+ data->include_depth = depth;
+ data->fetcher = fetcher;
+ data->fetcher_baton = fetcher_baton;
+
+ XML_SetCharacterDataHandler (parser->expat_parser, NULL);
+ XML_SetDefaultHandler (parser->expat_parser, xml_xinclude_default);
+
+ /* Always discard the XML version declarations; the only important
+ thing this provides is encoding, and our result will have been
+ converted to UTF-8. */
+ XML_SetXmlDeclHandler (parser->expat_parser, xml_xinclude_xml_decl);
+
+ if (depth > 0)
+ /* Discard the doctype for included documents. */
+ XML_SetDoctypeDeclHandler (parser->expat_parser,
+ xml_xinclude_start_doctype,
+ xml_xinclude_end_doctype);
+
+ gdb_xml_use_dtd (parser, "xinclude.dtd");
+
+ if (gdb_xml_parse (parser, text) == 0)
+ {
+ obstack_1grow (&data->obstack, '\0');
+ result = xstrdup (obstack_finish (&data->obstack));
+
+ if (depth == 0)
+ gdb_xml_debug (parser, _("XInclude processing succeeded:\n%s"),
+ result);
+ }
+ else
+ result = NULL;
+
+ do_cleanups (back_to);
+ return result;
+}
#endif /* HAVE_LIBEXPAT */
+\f
+
+/* Return an XML document which was compiled into GDB, from
+ the given FILENAME, or NULL if the file was not compiled in. */
+
+const char *
+fetch_xml_builtin (const char *filename)
+{
+ const char *(*p)[2];
+
+ for (p = xml_builtin; (*p)[0]; p++)
+ if (strcmp ((*p)[0], filename) == 0)
+ return (*p)[1];
+
+ return NULL;
+}
+
+/* A to_xfer_partial helper function which reads XML files which were
+ compiled into GDB. The target may call this function from its own
+ to_xfer_partial handler, after converting object and annex to the
+ appropriate filename. */
+
+LONGEST
+xml_builtin_xfer_partial (const char *filename,
+ gdb_byte *readbuf, const gdb_byte *writebuf,
+ ULONGEST offset, LONGEST len)
+{
+ const char *buf;
+ LONGEST len_avail;
+
+ gdb_assert (readbuf != NULL && writebuf == NULL);
+ gdb_assert (filename != NULL);
+
+ buf = fetch_xml_builtin (filename);
+ if (buf == NULL)
+ return -1;
+
+ len_avail = strlen (buf);
+ if (offset >= len_avail)
+ return 0;
+
+ if (len > len_avail - offset)
+ len = len_avail - offset;
+ memcpy (readbuf, buf + offset, len);
+ return len;
+}
+\f
static void
show_debug_xml (struct ui_file *file, int from_tty,