/* Interface to libxml2.
Copyright (C) 2010-2020 Free Software Foundation, Inc.
This file is part of GNU Emacs.
GNU Emacs 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.
GNU Emacs 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 GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */
#include <config.h>
#include "lisp.h"
#include "buffer.h"
#ifdef HAVE_LIBXML2
#include <libxml/tree.h>
#include <libxml/parser.h>
#include <libxml/HTMLparser.h>
#ifdef WINDOWSNT
# include <windows.h>
# include "w32common.h"
# include "w32.h"
DEF_DLL_FN (htmlDocPtr, htmlReadMemory,
(const char *, int, const char *, const char *, int));
DEF_DLL_FN (xmlDocPtr, xmlReadMemory,
(const char *, int, const char *, const char *, int));
DEF_DLL_FN (xmlNodePtr, xmlDocGetRootElement, (xmlDocPtr));
DEF_DLL_FN (void, xmlFreeDoc, (xmlDocPtr));
DEF_DLL_FN (void, xmlCleanupParser, (void));
DEF_DLL_FN (void, xmlCheckVersion, (int));
static bool
libxml2_loaded_p (void)
{
Lisp_Object found = Fassq (Qlibxml2, Vlibrary_cache);
return CONSP (found) && EQ (XCDR (found), Qt);
}
# undef htmlReadMemory
# undef xmlCheckVersion
# undef xmlCleanupParser
# undef xmlDocGetRootElement
# undef xmlFreeDoc
# undef xmlReadMemory
# define htmlReadMemory fn_htmlReadMemory
# define xmlCheckVersion fn_xmlCheckVersion
# define xmlCleanupParser fn_xmlCleanupParser
# define xmlDocGetRootElement fn_xmlDocGetRootElement
# define xmlFreeDoc fn_xmlFreeDoc
# define xmlReadMemory fn_xmlReadMemory
static bool
load_dll_functions (HMODULE library)
{
LOAD_DLL_FN (library, htmlReadMemory);
LOAD_DLL_FN (library, xmlReadMemory);
LOAD_DLL_FN (library, xmlDocGetRootElement);
LOAD_DLL_FN (library, xmlFreeDoc);
LOAD_DLL_FN (library, xmlCleanupParser);
LOAD_DLL_FN (library, xmlCheckVersion);
return true;
}
#else /* !WINDOWSNT */
static bool
libxml2_loaded_p (void)
{
return true;
}
#endif /* !WINDOWSNT */
static bool
init_libxml2_functions (void)
{
#ifdef WINDOWSNT
if (libxml2_loaded_p ())
return true;
else
{
HMODULE library;
if (!(library = w32_delayed_load (Qlibxml2)))
{
message1 ("libxml2 library not found");
return false;
}
if (! load_dll_functions (library))
goto bad_library;
Vlibrary_cache = Fcons (Fcons (Qlibxml2, Qt), Vlibrary_cache);
return true;
}
bad_library:
Vlibrary_cache = Fcons (Fcons (Qlibxml2, Qnil), Vlibrary_cache);
return false;
#else /* !WINDOWSNT */
return true;
#endif /* !WINDOWSNT */
}
static Lisp_Object
make_dom (xmlNode *node)
{
if (node->type == XML_ELEMENT_NODE)
{
Lisp_Object result = list1 (intern ((char *) node->name));
xmlNode *child;
xmlAttr *property;
Lisp_Object plist = Qnil;
/* First add the attributes. */
property = node->properties;
while (property != NULL)
{
if (property->children &&
property->children->content)
{
char *content = (char *) property->children->content;
plist = Fcons (Fcons (intern ((char *) property->name),
build_string (content)),
plist);
}
property = property->next;
}
result = Fcons (Fnreverse (plist), result);
/* Then add the children of the node. */
child = node->children;
while (child != NULL)
{
result = Fcons (make_dom (child), result);
child = child->next;
}
return Fnreverse (result);
}
else if (node->type == XML_TEXT_NODE || node->type == XML_CDATA_SECTION_NODE)
{
if (node->content)
return build_string ((char *) node->content);
else
return Qnil;
}
else if (node->type == XML_COMMENT_NODE)
{
if (node->content)
return list3 (intern ("comment"), Qnil,
build_string ((char *) node->content));
else
return Qnil;
}
else
return Qnil;
}
static Lisp_Object
parse_region (Lisp_Object start, Lisp_Object end, Lisp_Object base_url,
Lisp_Object discard_comments, bool htmlp)
{
xmlDoc *doc;
Lisp_Object result = Qnil;
const char *burl = "";
ptrdiff_t istart, iend, istart_byte, iend_byte;
unsigned char *buftext;
xmlCheckVersion (LIBXML_VERSION);
validate_region (&start, &end);
istart = XFIXNUM (start);
iend = XFIXNUM (end);
istart_byte = CHAR_TO_BYTE (istart);
iend_byte = CHAR_TO_BYTE (iend);
if (istart < GPT && GPT < iend)
move_gap_both (iend, iend_byte);
if (! NILP (base_url))
{
CHECK_STRING (base_url);
burl = SSDATA (base_url);
}
buftext = BYTE_POS_ADDR (istart_byte);
#ifdef REL_ALLOC
/* Prevent ralloc.c from relocating the current buffer while libxml2
functions below read its text. */
r_alloc_inhibit_buffer_relocation (1);
#endif
if (htmlp)
doc = htmlReadMemory ((char *)buftext,
iend_byte - istart_byte, burl, "utf-8",
HTML_PARSE_RECOVER|HTML_PARSE_NONET|
HTML_PARSE_NOWARNING|HTML_PARSE_NOERROR|
HTML_PARSE_NOBLANKS);
else
doc = xmlReadMemory ((char *)buftext,
iend_byte - istart_byte, burl, "utf-8",
XML_PARSE_NONET|XML_PARSE_NOWARNING|
XML_PARSE_NOBLANKS |XML_PARSE_NOERROR);
#ifdef REL_ALLOC
r_alloc_inhibit_buffer_relocation (0);
#endif
/* If the assertion below fails, malloc was called inside the above
libxml2 functions, and ralloc.c caused relocation of buffer text,
so we could have read from unrelated memory. */
eassert (buftext == BYTE_POS_ADDR (istart_byte));
if (doc != NULL)
{
Lisp_Object r = Qnil;
if (NILP(discard_comments))
{
/* If the document has toplevel comments, then this should
get us the nodes and the comments. */
xmlNode *n = doc->children;
while (n) {
if (!NILP (r))
result = Fcons (r, result);
r = make_dom (n);
n = n->next;
}
}
if (NILP (result)) {
/* The document doesn't have toplevel comments or we discarded
them. Get the tree the proper way. */
xmlNode *node = xmlDocGetRootElement (doc);
if (node != NULL)
result = make_dom (node);
} else
result = Fcons (Qtop, Fcons (Qnil, Fnreverse (Fcons (r, result))));
xmlFreeDoc (doc);
}
return result;
}
void
xml_cleanup_parser (void)
{
if (libxml2_loaded_p ())
xmlCleanupParser ();
}
DEFUN ("libxml-parse-html-region", Flibxml_parse_html_region,
Slibxml_parse_html_region,
2, 4, 0,
doc: /* Parse the region as an HTML document and return the parse tree.
If BASE-URL is non-nil, it is used to expand relative URLs.
If you want comments to be stripped, use the `xml-remove-comments'
function to strip comments before calling this function. */)
(Lisp_Object start, Lisp_Object end, Lisp_Object base_url, Lisp_Object discard_comments)
{
if (init_libxml2_functions ())
return parse_region (start, end, base_url, discard_comments, true);
return Qnil;
}
DEFUN ("libxml-parse-xml-region", Flibxml_parse_xml_region,
Slibxml_parse_xml_region,
2, 4, 0,
doc: /* Parse the region as an XML document and return the parse tree.
If BASE-URL is non-nil, it is used to expand relative URLs.
If you want comments to be stripped, use the `xml-remove-comments'
function to strip comments before calling this function. */)
(Lisp_Object start, Lisp_Object end, Lisp_Object base_url, Lisp_Object discard_comments)
{
if (init_libxml2_functions ())
return parse_region (start, end, base_url, discard_comments, false);
return Qnil;
}
#endif /* HAVE_LIBXML2 */
DEFUN ("libxml-available-p", Flibxml_available_p, Slibxml_available_p, 0, 0, 0,
doc: /* Return t if libxml2 support is available in this instance of Emacs.*/)
(void)
{
#ifdef HAVE_LIBXML2
# ifdef WINDOWSNT
Lisp_Object found = Fassq (Qlibxml2, Vlibrary_cache);
if (CONSP (found))
return XCDR (found);
else
{
Lisp_Object status;
status = init_libxml2_functions () ? Qt : Qnil;
Vlibrary_cache = Fcons (Fcons (Qlibxml2, status), Vlibrary_cache);
return status;
}
# else
return Qt;
# endif /* WINDOWSNT */
#else
return Qnil;
#endif /* HAVE_LIBXML2 */
}
/***********************************************************************
Initialization
***********************************************************************/
void
syms_of_xml (void)
{
#ifdef HAVE_LIBXML2
defsubr (&Slibxml_parse_html_region);
defsubr (&Slibxml_parse_xml_region);
#endif
defsubr (&Slibxml_available_p);
}