binutils-gdb/gdb/xml-support.c
Pedro Alves 492d29ea1c Split TRY_CATCH into TRY + CATCH
This patch splits the TRY_CATCH macro into three, so that we go from
this:

~~~
  volatile gdb_exception ex;

  TRY_CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  if (ex.reason < 0)
    {
    }
~~~

to this:

~~~
  TRY
    {
    }
  CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  END_CATCH
~~~

Thus, we'll be getting rid of the local volatile exception object, and
declaring the caught exception in the catch block.

This allows reimplementing TRY/CATCH in terms of C++ exceptions when
building in C++ mode, while still allowing to build GDB in C mode
(using setjmp/longjmp), as a transition step.

TBC, after this patch, is it _not_ valid to have code between the TRY
and the CATCH blocks, like:

  TRY
    {
    }

  // some code here.

  CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  END_CATCH

Just like it isn't valid to do that with C++'s native try/catch.

By switching to creating the exception object inside the CATCH block
scope, we can get rid of all the explicitly allocated volatile
exception objects all over the tree, and map the CATCH block more
directly to C++'s catch blocks.

The majority of the TRY_CATCH -> TRY+CATCH+END_CATCH conversion was
done with a script, rerun from scratch at every rebase, no manual
editing involved.  After the mechanical conversion, a few places
needed manual intervention, to fix preexisting cases where we were
using the exception object outside of the TRY_CATCH block, and cases
where we were using "else" after a 'if (ex.reason) < 0)' [a CATCH
after this patch].  The result was folded into this patch so that GDB
still builds at each incremental step.

END_CATCH is necessary for two reasons:

First, because we name the exception object in the CATCH block, which
requires creating a scope, which in turn must be closed somewhere.
Declaring the exception variable in the initializer field of a for
block, like:

  #define CATCH(EXCEPTION, mask) \
    for (struct gdb_exception EXCEPTION; \
         exceptions_state_mc_catch (&EXCEPTION, MASK); \
	 EXCEPTION = exception_none)

would avoid needing END_CATCH, but alas, in C mode, we build with C90,
which doesn't allow mixed declarations and code.

Second, because when TRY/CATCH are wired to real C++ try/catch, as
long as we need to handle cleanup chains, even if there's no CATCH
block that wants to catch the exception, we need for stop at every
frame in the unwind chain and run cleanups, then rethrow.  That will
be done in END_CATCH.

After we require C++, we'll still need TRY/CATCH/END_CATCH until
cleanups are completely phased out -- TRY/CATCH in C++ mode will
save/restore the current cleanup chain, like in C mode, and END_CATCH
catches otherwise uncaugh exceptions, runs cleanups and rethrows, so
that C++ cleanups and exceptions can coexist.

IMO, this still makes the TRY/CATCH code look a bit more like a
newcomer would expect, so IMO worth it even if we weren't considering
C++.

gdb/ChangeLog.
2015-03-07  Pedro Alves  <palves@redhat.com>

	* common/common-exceptions.c (struct catcher) <exception>: No
	longer a pointer to volatile exception.  Now an exception value.
	<mask>: Delete field.
	(exceptions_state_mc_init): Remove all parameters.  Adjust.
	(exceptions_state_mc): No longer pop the catcher here.
	(exceptions_state_mc_catch): New function.
	(throw_exception): Adjust.
	* common/common-exceptions.h (exceptions_state_mc_init): Remove
	all parameters.
	(exceptions_state_mc_catch): Declare.
	(TRY_CATCH): Rename to ...
	(TRY): ... this.  Remove EXCEPTION and MASK parameters.
	(CATCH, END_CATCH): New.
	All callers adjusted.

gdb/gdbserver/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	Adjust all callers of TRY_CATCH to use TRY/CATCH/END_CATCH
	instead.
2015-03-07 15:14:14 +00:00

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/* Helper routines for parsing XML using Expat.
Copyright (C) 2006-2015 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 "gdbcmd.h"
#include "xml-support.h"
#include "filestuff.h"
#include "safe-ctype.h"
/* Debugging flag. */
static int debug_xml;
/* The contents of this file are only useful if XML support is
available. */
#ifdef HAVE_LIBEXPAT
#include "gdb_expat.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 scope_level
{
/* Elements we allow at this level. */
const struct gdb_xml_element *elements;
/* The element which we are within. */
const struct gdb_xml_element *element;
/* Mask of which elements we've seen at this level (used for
optional and repeatable checking). */
unsigned int seen;
/* Body text accumulation. */
struct obstack *body;
};
typedef struct scope_level scope_level_s;
DEF_VEC_O(scope_level_s);
/* The parser itself, and our additional state. */
struct gdb_xml_parser
{
XML_Parser expat_parser; /* The underlying expat parser. */
const char *name; /* Name of this parser. */
void *user_data; /* The user's callback data, for handlers. */
VEC(scope_level_s) *scopes; /* Scoping stack. */
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
wrong to do anything with it immediately, because a single block of
text might be broken up into multiple calls to this function. */
static void
gdb_xml_body_text (void *data, const XML_Char *text, int length)
{
struct gdb_xml_parser *parser = data;
struct scope_level *scope = VEC_last (scope_level_s, parser->scopes);
if (parser->error.reason < 0)
return;
if (scope->body == NULL)
{
scope->body = XCNEW (struct obstack);
obstack_init (scope->body);
}
obstack_grow (scope->body, text, length);
}
/* Issue a debugging message from one of PARSER's handlers. */
void
gdb_xml_debug (struct gdb_xml_parser *parser, const char *format, ...)
{
int line = XML_GetCurrentLineNumber (parser->expat_parser);
va_list ap;
char *message;
if (!debug_xml)
return;
va_start (ap, format);
message = xstrvprintf (format, ap);
if (line)
fprintf_unfiltered (gdb_stderr, "%s (line %d): %s\n",
parser->name, line, message);
else
fprintf_unfiltered (gdb_stderr, "%s: %s\n",
parser->name, message);
xfree (message);
}
/* Issue an error message from one of PARSER's handlers, and stop
parsing. */
void
gdb_xml_error (struct gdb_xml_parser *parser, const char *format, ...)
{
int line = XML_GetCurrentLineNumber (parser->expat_parser);
va_list ap;
parser->last_line = line;
va_start (ap, format);
throw_verror (XML_PARSE_ERROR, format, ap);
}
/* Find the attribute named NAME in the set of parsed attributes
ATTRIBUTES. Returns NULL if not found. */
struct gdb_xml_value *
xml_find_attribute (VEC(gdb_xml_value_s) *attributes, const char *name)
{
struct gdb_xml_value *value;
int ix;
for (ix = 0; VEC_iterate (gdb_xml_value_s, attributes, ix, value); ix++)
if (strcmp (value->name, name) == 0)
return value;
return NULL;
}
/* Clean up a vector of parsed attribute values. */
static void
gdb_xml_values_cleanup (void *data)
{
VEC(gdb_xml_value_s) **values = data;
struct gdb_xml_value *value;
int ix;
for (ix = 0; VEC_iterate (gdb_xml_value_s, *values, ix, value); ix++)
xfree (value->value);
VEC_free (gdb_xml_value_s, *values);
}
/* Handle the start of an element. DATA is our local XML parser, NAME
is the element, and ATTRS are the names and values of this
element's attributes. */
static void
gdb_xml_start_element (void *data, const XML_Char *name,
const XML_Char **attrs)
{
struct gdb_xml_parser *parser = data;
struct scope_level *scope;
struct scope_level new_scope;
const struct gdb_xml_element *element;
const struct gdb_xml_attribute *attribute;
VEC(gdb_xml_value_s) *attributes = NULL;
unsigned int seen;
struct cleanup *back_to;
/* 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_quick_push (scope_level_s, parser->scopes, &new_scope);
gdb_xml_debug (parser, _("Entering element <%s>"), name);
/* Find this element in the list of the current scope's allowed
children. Record that we've seen it. */
seen = 1;
for (element = scope->elements; element && element->name;
element++, seen <<= 1)
if (strcmp (element->name, name) == 0)
break;
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);
return;
}
if (!(element->flags & GDB_XML_EF_REPEATABLE) && (seen & scope->seen))
gdb_xml_error (parser, _("Element <%s> only expected once"), name);
scope->seen |= seen;
back_to = make_cleanup (gdb_xml_values_cleanup, &attributes);
for (attribute = element->attributes;
attribute != NULL && attribute->name != NULL;
attribute++)
{
const char *val = NULL;
const XML_Char **p;
void *parsed_value;
struct gdb_xml_value new_value;
for (p = attrs; *p != NULL; p += 2)
if (!strcmp (attribute->name, p[0]))
{
val = p[1];
break;
}
if (*p != NULL && val == NULL)
{
gdb_xml_debug (parser, _("Attribute \"%s\" missing a value"),
attribute->name);
continue;
}
if (*p == NULL && !(attribute->flags & GDB_XML_AF_OPTIONAL))
{
gdb_xml_error (parser, _("Required attribute \"%s\" of "
"<%s> not specified"),
attribute->name, element->name);
continue;
}
if (*p == NULL)
continue;
gdb_xml_debug (parser, _("Parsing attribute %s=\"%s\""),
attribute->name, val);
if (attribute->handler)
parsed_value = attribute->handler (parser, attribute, val);
else
parsed_value = xstrdup (val);
new_value.name = attribute->name;
new_value.value = parsed_value;
VEC_safe_push (gdb_xml_value_s, attributes, &new_value);
}
/* Check for unrecognized attributes. */
if (debug_xml)
{
const XML_Char **p;
for (p = attrs; *p != NULL; p += 2)
{
for (attribute = element->attributes;
attribute != NULL && attribute->name != NULL;
attribute++)
if (strcmp (attribute->name, *p) == 0)
break;
if (attribute == NULL || attribute->name == NULL)
gdb_xml_debug (parser, _("Ignoring unknown attribute %s"), *p);
}
}
/* Call the element handler if there is one. */
if (element->start_handler)
element->start_handler (parser, element, parser->user_data, attributes);
/* Fill in a new scope level. */
scope = VEC_last (scope_level_s, parser->scopes);
scope->element = element;
scope->elements = element->children;
do_cleanups (back_to);
}
/* Wrapper for gdb_xml_start_element, to prevent throwing exceptions
through expat. */
static void
gdb_xml_start_element_wrapper (void *data, const XML_Char *name,
const XML_Char **attrs)
{
struct gdb_xml_parser *parser = data;
if (parser->error.reason < 0)
return;
TRY
{
gdb_xml_start_element (data, name, attrs);
}
CATCH (ex, RETURN_MASK_ALL)
{
parser->error = ex;
#ifdef HAVE_XML_STOPPARSER
XML_StopParser (parser->expat_parser, XML_FALSE);
#endif
}
END_CATCH
}
/* Handle the end of an element. DATA is our local XML parser, and
NAME is the current element. */
static void
gdb_xml_end_element (void *data, const XML_Char *name)
{
struct gdb_xml_parser *parser = data;
struct scope_level *scope = VEC_last (scope_level_s, parser->scopes);
const struct gdb_xml_element *element;
unsigned int seen;
gdb_xml_debug (parser, _("Leaving element <%s>"), name);
for (element = scope->elements, seen = 1;
element != NULL && element->name != NULL;
element++, seen <<= 1)
if ((scope->seen & seen) == 0
&& (element->flags & GDB_XML_EF_OPTIONAL) == 0)
gdb_xml_error (parser, _("Required element <%s> is missing"),
element->name);
/* Call the element processor. */
if (scope->element != NULL && scope->element->end_handler)
{
char *body;
if (scope->body == NULL)
body = "";
else
{
int length;
length = obstack_object_size (scope->body);
obstack_1grow (scope->body, '\0');
body = obstack_finish (scope->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)
{
obstack_free (scope->body, NULL);
xfree (scope->body);
}
VEC_pop (scope_level_s, parser->scopes);
}
/* Wrapper for gdb_xml_end_element, to prevent throwing exceptions
through expat. */
static void
gdb_xml_end_element_wrapper (void *data, const XML_Char *name)
{
struct gdb_xml_parser *parser = data;
if (parser->error.reason < 0)
return;
TRY
{
gdb_xml_end_element (data, name);
}
CATCH (ex, RETURN_MASK_ALL)
{
parser->error = ex;
#ifdef HAVE_XML_STOPPARSER
XML_StopParser (parser->expat_parser, XML_FALSE);
#endif
}
END_CATCH
}
/* Free a parser and all its associated state. */
static void
gdb_xml_cleanup (void *arg)
{
struct gdb_xml_parser *parser = arg;
struct scope_level *scope;
int ix;
XML_ParserFree (parser->expat_parser);
/* Clean up the scopes. */
for (ix = 0; VEC_iterate (scope_level_s, parser->scopes, ix, scope); ix++)
if (scope->body)
{
obstack_free (scope->body, NULL);
xfree (scope->body);
}
VEC_free (scope_level_s, parser->scopes);
xfree (parser);
}
/* Initialize a parser and store it to *PARSER_RESULT. Register a
cleanup to destroy the parser. */
static struct cleanup *
gdb_xml_create_parser_and_cleanup (const char *name,
const struct gdb_xml_element *elements,
void *user_data,
struct gdb_xml_parser **parser_result)
{
struct gdb_xml_parser *parser;
struct scope_level start_scope;
struct cleanup *result;
/* Initialize the parser. */
parser = XCNEW (struct gdb_xml_parser);
parser->expat_parser = XML_ParserCreateNS (NULL, '!');
if (parser->expat_parser == NULL)
{
xfree (parser);
malloc_failure (0);
}
parser->name = name;
parser->user_data = user_data;
XML_SetUserData (parser->expat_parser, parser);
/* Set the callbacks. */
XML_SetElementHandler (parser->expat_parser, gdb_xml_start_element_wrapper,
gdb_xml_end_element_wrapper);
XML_SetCharacterDataHandler (parser->expat_parser, gdb_xml_body_text);
/* Initialize the outer scope. */
memset (&start_scope, 0, sizeof (start_scope));
start_scope.elements = elements;
VEC_safe_push (scope_level_s, parser->scopes, &start_scope);
*parser_result = parser;
return make_cleanup (gdb_xml_cleanup, 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.
The return value is 0 for success or -1 for error. It may throw,
but only if something unexpected goes wrong during parsing; parse
errors will be caught, warned about, and reported as failure. */
int
gdb_xml_parse (struct gdb_xml_parser *parser, const char *buffer)
{
enum XML_Status status;
const char *error_string;
gdb_xml_debug (parser, _("Starting:\n%s"), buffer);
status = XML_Parse (parser->expat_parser, buffer, strlen (buffer), 1);
if (status == XML_STATUS_OK && parser->error.reason == 0)
return 0;
if (parser->error.reason == RETURN_ERROR
&& parser->error.error == XML_PARSE_ERROR)
{
gdb_assert (parser->error.message != NULL);
error_string = parser->error.message;
}
else if (status == XML_STATUS_ERROR)
{
enum XML_Error err = XML_GetErrorCode (parser->expat_parser);
error_string = XML_ErrorString (err);
}
else
{
gdb_assert (parser->error.reason < 0);
throw_exception (parser->error);
}
if (parser->last_line != 0)
warning (_("while parsing %s (at line %d): %s"), parser->name,
parser->last_line, error_string);
else
warning (_("while parsing %s: %s"), parser->name, error_string);
return -1;
}
int
gdb_xml_parse_quick (const char *name, const char *dtd_name,
const struct gdb_xml_element *elements,
const char *document, void *user_data)
{
struct gdb_xml_parser *parser;
struct cleanup *back_to;
int result;
back_to = gdb_xml_create_parser_and_cleanup (name, elements,
user_data, &parser);
if (dtd_name != NULL)
gdb_xml_use_dtd (parser, dtd_name);
result = gdb_xml_parse (parser, document);
do_cleanups (back_to);
return result;
}
/* Parse a field VALSTR that we expect to contain an integer value.
The integer is returned in *VALP. The string is parsed with an
equivalent to strtoul.
Returns 0 for success, -1 for error. */
static int
xml_parse_unsigned_integer (const char *valstr, ULONGEST *valp)
{
const char *endptr;
ULONGEST result;
if (*valstr == '\0')
return -1;
result = strtoulst (valstr, &endptr, 0);
if (*endptr != '\0')
return -1;
*valp = result;
return 0;
}
/* Parse an integer string into a ULONGEST and return it, or call
gdb_xml_error if it could not be parsed. */
ULONGEST
gdb_xml_parse_ulongest (struct gdb_xml_parser *parser, const char *value)
{
ULONGEST result;
if (xml_parse_unsigned_integer (value, &result) != 0)
gdb_xml_error (parser, _("Can't convert \"%s\" to an integer"), value);
return result;
}
/* Parse an integer attribute into a ULONGEST. */
void *
gdb_xml_parse_attr_ulongest (struct gdb_xml_parser *parser,
const struct gdb_xml_attribute *attribute,
const char *value)
{
ULONGEST result;
void *ret;
if (xml_parse_unsigned_integer (value, &result) != 0)
gdb_xml_error (parser, _("Can't convert %s=\"%s\" to an integer"),
attribute->name, value);
ret = xmalloc (sizeof (result));
memcpy (ret, &result, sizeof (result));
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
with NAME == NULL. */
void *
gdb_xml_parse_attr_enum (struct gdb_xml_parser *parser,
const struct gdb_xml_attribute *attribute,
const char *value)
{
const struct gdb_xml_enum *enums = attribute->handler_data;
void *ret;
for (enums = attribute->handler_data; enums->name != NULL; enums++)
if (strcasecmp (enums->name, value) == 0)
break;
if (enums->name == NULL)
gdb_xml_error (parser, _("Unknown attribute value %s=\"%s\""),
attribute->name, value);
ret = xmalloc (sizeof (enums->value));
memcpy (ret, &enums->value, sizeof (enums->value));
return ret;
}
/* 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 = xml_find_attribute (attributes, "href")->value;
struct cleanup *back_to;
char *text, *output;
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)
{
struct gdb_xml_parser *parser;
struct xinclude_parsing_data *data;
struct cleanup *back_to;
char *result = NULL;
data = XCNEW (struct xinclude_parsing_data);
obstack_init (&data->obstack);
back_to = make_cleanup (xml_xinclude_cleanup, data);
gdb_xml_create_parser_and_cleanup (name, xinclude_elements,
data, &parser);
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."));
}
else
result = NULL;
do_cleanups (back_to);
return result;
}
#endif /* HAVE_LIBEXPAT */
/* 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;
}
static void
show_debug_xml (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
{
fprintf_filtered (file, _("XML debugging is %s.\n"), value);
}
void
obstack_xml_printf (struct obstack *obstack, const char *format, ...)
{
va_list ap;
const char *f;
const char *prev;
int percent = 0;
va_start (ap, format);
prev = format;
for (f = format; *f; f++)
{
if (percent)
{
switch (*f)
{
case 's':
{
char *p;
char *a = va_arg (ap, char *);
obstack_grow (obstack, prev, f - prev - 1);
p = xml_escape_text (a);
obstack_grow_str (obstack, p);
xfree (p);
prev = f + 1;
}
break;
}
percent = 0;
}
else if (*f == '%')
percent = 1;
}
obstack_grow_str (obstack, prev);
va_end (ap);
}
char *
xml_fetch_content_from_file (const char *filename, void *baton)
{
const char *dirname = baton;
FILE *file;
struct cleanup *back_to;
char *text;
size_t len, offset;
if (dirname && *dirname)
{
char *fullname = concat (dirname, "/", filename, (char *) NULL);
if (fullname == NULL)
malloc_failure (0);
file = gdb_fopen_cloexec (fullname, FOPEN_RT);
xfree (fullname);
}
else
file = gdb_fopen_cloexec (filename, FOPEN_RT);
if (file == NULL)
return NULL;
back_to = make_cleanup_fclose (file);
/* Read in the whole file, one chunk at a time. */
len = 4096;
offset = 0;
text = xmalloc (len);
make_cleanup (free_current_contents, &text);
while (1)
{
size_t bytes_read;
/* Continue reading where the last read left off. Leave at least
one byte so that we can NUL-terminate the result. */
bytes_read = fread (text + offset, 1, len - offset - 1, file);
if (ferror (file))
{
warning (_("Read error from \"%s\""), filename);
do_cleanups (back_to);
return NULL;
}
offset += bytes_read;
if (feof (file))
break;
len = len * 2;
text = xrealloc (text, len);
}
fclose (file);
discard_cleanups (back_to);
text[offset] = '\0';
return text;
}
void _initialize_xml_support (void);
void
_initialize_xml_support (void)
{
add_setshow_boolean_cmd ("xml", class_maintenance, &debug_xml,
_("Set XML parser debugging."),
_("Show XML parser debugging."),
_("When set, debugging messages for XML parsers "
"are displayed."),
NULL, show_debug_xml,
&setdebuglist, &showdebuglist);
}