parser.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

	ctxt->nsNr = 0;
	ctxt->nsTab = (const xmlChar **)
	              xmlMalloc(ctxt->nsMax * sizeof(xmlChar *));
	if (ctxt->nsTab == NULL) {
	    xmlErrMemory(ctxt, NULL);
	    ctxt->nsMax = 0;
            return (-1);
	}
    } else if (ctxt->nsNr >= ctxt->nsMax) {
        ctxt->nsMax *= 2;
        ctxt->nsTab = (const xmlChar **)
	              xmlRealloc((char *) ctxt->nsTab,
				 ctxt->nsMax * sizeof(ctxt->nsTab[0]));
        if (ctxt->nsTab == NULL) {
            xmlErrMemory(ctxt, NULL);
	    ctxt->nsMax /= 2;
            return (-1);
        }
    }
    ctxt->nsTab[ctxt->nsNr++] = prefix;
    ctxt->nsTab[ctxt->nsNr++] = URL;
    return (ctxt->nsNr);
}
/**
 * nsPop:
 * @ctxt: an XML parser context
 * @nr:  the number to pop
 *
 * Pops the top @nr parser prefix/namespace from the ns stack
 *
 * Returns the number of namespaces removed
 */
static int
nsPop(xmlParserCtxtPtr ctxt, int nr)
{
    int i;

    if (ctxt->nsTab == NULL) return(0);
    if (ctxt->nsNr < nr) {
        xmlGenericError(xmlGenericErrorContext, "Pbm popping %d NS\n", nr);
        nr = ctxt->nsNr;
    }
    if (ctxt->nsNr <= 0)
        return (0);
    
    for (i = 0;i < nr;i++) {
         ctxt->nsNr--;
	 ctxt->nsTab[ctxt->nsNr] = NULL;
    }
    return(nr);
}
#endif

static int
xmlCtxtGrowAttrs(xmlParserCtxtPtr ctxt, int nr) {
    const xmlChar **atts;
    int *attallocs;
    int maxatts;

    if (ctxt->atts == NULL) {
	maxatts = 55; /* allow for 10 attrs by default */
	atts = (const xmlChar **)
	       xmlMalloc(maxatts * sizeof(xmlChar *));
	if (atts == NULL) goto mem_error;
	ctxt->atts = atts;
	attallocs = (int *) xmlMalloc((maxatts / 5) * sizeof(int));
	if (attallocs == NULL) goto mem_error;
	ctxt->attallocs = attallocs;
	ctxt->maxatts = maxatts;
    } else if (nr + 5 > ctxt->maxatts) {
	maxatts = (nr + 5) * 2;
	atts = (const xmlChar **) xmlRealloc((void *) ctxt->atts,
				     maxatts * sizeof(const xmlChar *));
	if (atts == NULL) goto mem_error;
	ctxt->atts = atts;
	attallocs = (int *) xmlRealloc((void *) ctxt->attallocs,
	                             (maxatts / 5) * sizeof(int));
	if (attallocs == NULL) goto mem_error;
	ctxt->attallocs = attallocs;
	ctxt->maxatts = maxatts;
    }
    return(ctxt->maxatts);
mem_error:
    xmlErrMemory(ctxt, NULL);
    return(-1);
}

/**
 * inputPush:
 * @ctxt:  an XML parser context
 * @value:  the parser input
 *
 * Pushes a new parser input on top of the input stack
 *
 * Returns 0 in case of error, the index in the stack otherwise
 */
int
inputPush(xmlParserCtxtPtr ctxt, xmlParserInputPtr value)
{
    if ((ctxt == NULL) || (value == NULL))
        return(0);
    if (ctxt->inputNr >= ctxt->inputMax) {
        ctxt->inputMax *= 2;
        ctxt->inputTab =
            (xmlParserInputPtr *) xmlRealloc(ctxt->inputTab,
                                             ctxt->inputMax *
                                             sizeof(ctxt->inputTab[0]));
        if (ctxt->inputTab == NULL) {
            xmlErrMemory(ctxt, NULL);
            return (0);
        }
    }
    ctxt->inputTab[ctxt->inputNr] = value;
    ctxt->input = value;
    return (ctxt->inputNr++);
}
/**
 * inputPop:
 * @ctxt: an XML parser context
 *
 * Pops the top parser input from the input stack
 *
 * Returns the input just removed
 */
xmlParserInputPtr
inputPop(xmlParserCtxtPtr ctxt)
{
    xmlParserInputPtr ret;

    if (ctxt == NULL)
        return(NULL);
    if (ctxt->inputNr <= 0)
        return (0);
    ctxt->inputNr--;
    if (ctxt->inputNr > 0)
        ctxt->input = ctxt->inputTab[ctxt->inputNr - 1];
    else
        ctxt->input = NULL;
    ret = ctxt->inputTab[ctxt->inputNr];
    ctxt->inputTab[ctxt->inputNr] = 0;
    return (ret);
}
/**
 * nodePush:
 * @ctxt:  an XML parser context
 * @value:  the element node
 *
 * Pushes a new element node on top of the node stack
 *
 * Returns 0 in case of error, the index in the stack otherwise
 */
int
nodePush(xmlParserCtxtPtr ctxt, xmlNodePtr value)
{
    if (ctxt == NULL) return(0);
    if (ctxt->nodeNr >= ctxt->nodeMax) {
        xmlNodePtr *tmp;

	tmp = (xmlNodePtr *) xmlRealloc(ctxt->nodeTab,
                                      ctxt->nodeMax * 2 *
                                      sizeof(ctxt->nodeTab[0]));
        if (tmp == NULL) {
            xmlErrMemory(ctxt, NULL);
            return (0);
        }
        ctxt->nodeTab = tmp;
	ctxt->nodeMax *= 2;
    }
    if (((unsigned int) ctxt->nodeNr) > xmlParserMaxDepth) {
	xmlFatalErrMsgInt(ctxt, XML_ERR_INTERNAL_ERROR,
		 "Excessive depth in document: change xmlParserMaxDepth = %d\n",
			  xmlParserMaxDepth);
	ctxt->instate = XML_PARSER_EOF;
	return(0);
    }
    ctxt->nodeTab[ctxt->nodeNr] = value;
    ctxt->node = value;
    return (ctxt->nodeNr++);
}
/**
 * nodePop:
 * @ctxt: an XML parser context
 *
 * Pops the top element node from the node stack
 *
 * Returns the node just removed
 */
xmlNodePtr
nodePop(xmlParserCtxtPtr ctxt)
{
    xmlNodePtr ret;

    if (ctxt == NULL) return(NULL);
    if (ctxt->nodeNr <= 0)
        return (NULL);
    ctxt->nodeNr--;
    if (ctxt->nodeNr > 0)
        ctxt->node = ctxt->nodeTab[ctxt->nodeNr - 1];
    else
        ctxt->node = NULL;
    ret = ctxt->nodeTab[ctxt->nodeNr];
    ctxt->nodeTab[ctxt->nodeNr] = 0;
    return (ret);
}

#ifdef LIBXML_PUSH_ENABLED
/**
 * nameNsPush:
 * @ctxt:  an XML parser context
 * @value:  the element name
 * @prefix:  the element prefix
 * @URI:  the element namespace name
 *
 * Pushes a new element name/prefix/URL on top of the name stack
 *
 * Returns -1 in case of error, the index in the stack otherwise
 */
static int
nameNsPush(xmlParserCtxtPtr ctxt, const xmlChar * value,
           const xmlChar *prefix, const xmlChar *URI, int nsNr)
{
    if (ctxt->nameNr >= ctxt->nameMax) {
        const xmlChar * *tmp;
        void **tmp2;
        ctxt->nameMax *= 2;
        tmp = (const xmlChar * *) xmlRealloc((xmlChar * *)ctxt->nameTab,
                                    ctxt->nameMax *
                                    sizeof(ctxt->nameTab[0]));
        if (tmp == NULL) {
	    ctxt->nameMax /= 2;
	    goto mem_error;
        }
	ctxt->nameTab = tmp;
        tmp2 = (void **) xmlRealloc((void * *)ctxt->pushTab,
                                    ctxt->nameMax * 3 *
                                    sizeof(ctxt->pushTab[0]));
        if (tmp2 == NULL) {
	    ctxt->nameMax /= 2;
	    goto mem_error;
        }
	ctxt->pushTab = tmp2;
    }
    ctxt->nameTab[ctxt->nameNr] = value;
    ctxt->name = value;
    ctxt->pushTab[ctxt->nameNr * 3] = (void *) prefix;
    ctxt->pushTab[ctxt->nameNr * 3 + 1] = (void *) URI;
    ctxt->pushTab[ctxt->nameNr * 3 + 2] = (void *) (long) nsNr;
    return (ctxt->nameNr++);
mem_error:
    xmlErrMemory(ctxt, NULL);
    return (-1);
}
/**
 * nameNsPop:
 * @ctxt: an XML parser context
 *
 * Pops the top element/prefix/URI name from the name stack
 *
 * Returns the name just removed
 */
static const xmlChar *
nameNsPop(xmlParserCtxtPtr ctxt)
{
    const xmlChar *ret;

    if (ctxt->nameNr <= 0)
        return (0);
    ctxt->nameNr--;
    if (ctxt->nameNr > 0)
        ctxt->name = ctxt->nameTab[ctxt->nameNr - 1];
    else
        ctxt->name = NULL;
    ret = ctxt->nameTab[ctxt->nameNr];
    ctxt->nameTab[ctxt->nameNr] = NULL;
    return (ret);
}
#endif /* LIBXML_PUSH_ENABLED */

/**
 * namePush:
 * @ctxt:  an XML parser context
 * @value:  the element name
 *
 * Pushes a new element name on top of the name stack
 *
 * Returns -1 in case of error, the index in the stack otherwise
 */
int
namePush(xmlParserCtxtPtr ctxt, const xmlChar * value)
{
    if (ctxt == NULL) return (-1);

    if (ctxt->nameNr >= ctxt->nameMax) {
        const xmlChar * *tmp;
        ctxt->nameMax *= 2;
        tmp = (const xmlChar * *) xmlRealloc((xmlChar * *)ctxt->nameTab,
                                    ctxt->nameMax *
                                    sizeof(ctxt->nameTab[0]));
        if (tmp == NULL) {
	    ctxt->nameMax /= 2;
	    goto mem_error;
        }
	ctxt->nameTab = tmp;
    }
    ctxt->nameTab[ctxt->nameNr] = value;
    ctxt->name = value;
    return (ctxt->nameNr++);
mem_error:
    xmlErrMemory(ctxt, NULL);
    return (-1);
}
/**
 * namePop:
 * @ctxt: an XML parser context
 *
 * Pops the top element name from the name stack
 *
 * Returns the name just removed
 */
const xmlChar *
namePop(xmlParserCtxtPtr ctxt)
{
    const xmlChar *ret;

    if ((ctxt == NULL) || (ctxt->nameNr <= 0))
        return (NULL);
    ctxt->nameNr--;
    if (ctxt->nameNr > 0)
        ctxt->name = ctxt->nameTab[ctxt->nameNr - 1];
    else
        ctxt->name = NULL;
    ret = ctxt->nameTab[ctxt->nameNr];
    ctxt->nameTab[ctxt->nameNr] = 0;
    return (ret);
}

static int spacePush(xmlParserCtxtPtr ctxt, int val) {
    if (ctxt->spaceNr >= ctxt->spaceMax) {
	ctxt->spaceMax *= 2;
        ctxt->spaceTab = (int *) xmlRealloc(ctxt->spaceTab,
	             ctxt->spaceMax * sizeof(ctxt->spaceTab[0]));
        if (ctxt->spaceTab == NULL) {
	    xmlErrMemory(ctxt, NULL);
	    return(0);
	}
    }
    ctxt->spaceTab[ctxt->spaceNr] = val;
    ctxt->space = &ctxt->spaceTab[ctxt->spaceNr];
    return(ctxt->spaceNr++);
}

static int spacePop(xmlParserCtxtPtr ctxt) {
    int ret;
    if (ctxt->spaceNr <= 0) return(0);
    ctxt->spaceNr--;
    if (ctxt->spaceNr > 0)
	ctxt->space = &ctxt->spaceTab[ctxt->spaceNr - 1];
    else
        ctxt->space = NULL;
    ret = ctxt->spaceTab[ctxt->spaceNr];
    ctxt->spaceTab[ctxt->spaceNr] = -1;
    return(ret);
}

/*
 * Macros for accessing the content. Those should be used only by the parser,
 * and not exported.
 *
 * Dirty macros, i.e. one often need to make assumption on the context to
 * use them
 *
 *   CUR_PTR return the current pointer to the xmlChar to be parsed.
 *           To be used with extreme caution since operations consuming
 *           characters may move the input buffer to a different location !
 *   CUR     returns the current xmlChar value, i.e. a 8 bit value if compiled
 *           This should be used internally by the parser
 *           only to compare to ASCII values otherwise it would break when
 *           running with UTF-8 encoding.
 *   RAW     same as CUR but in the input buffer, bypass any token
 *           extraction that may have been done
 *   NXT(n)  returns the n'th next xmlChar. Same as CUR is should be used only
 *           to compare on ASCII based substring.
 *   SKIP(n) Skip n xmlChar, and must also be used only to skip ASCII defined
 *           strings without newlines within the parser.
 *   NEXT1(l) Skip 1 xmlChar, and must also be used only to skip 1 non-newline ASCII 
 *           defined char within the parser.
 * Clean macros, not dependent of an ASCII context, expect UTF-8 encoding
 *
 *   NEXT    Skip to the next character, this does the proper decoding
 *           in UTF-8 mode. It also pop-up unfinished entities on the fly.
 *   NEXTL(l) Skip the current unicode character of l xmlChars long.
 *   CUR_CHAR(l) returns the current unicode character (int), set l
 *           to the number of xmlChars used for the encoding [0-5].
 *   CUR_SCHAR  same but operate on a string instead of the context
 *   COPY_BUF  copy the current unicode char to the target buffer, increment
 *            the index
 *   GROW, SHRINK  handling of input buffers
 */

#define RAW (*ctxt->input->cur)
#define CUR (*ctxt->input->cur)
#define NXT(val) ctxt->input->cur[(val)]
#define CUR_PTR ctxt->input->cur

#define CMP4( s, c1, c2, c3, c4 ) \
  ( ((unsigned char *) s)[ 0 ] == c1 && ((unsigned char *) s)[ 1 ] == c2 && \
    ((unsigned char *) s)[ 2 ] == c3 && ((unsigned char *) s)[ 3 ] == c4 )
#define CMP5( s, c1, c2, c3, c4, c5 ) \
  ( CMP4( s, c1, c2, c3, c4 ) && ((unsigned char *) s)[ 4 ] == c5 )
#define CMP6( s, c1, c2, c3, c4, c5, c6 ) \
  ( CMP5( s, c1, c2, c3, c4, c5 ) && ((unsigned char *) s)[ 5 ] == c6 )
#define CMP7( s, c1, c2, c3, c4, c5, c6, c7 ) \
  ( CMP6( s, c1, c2, c3, c4, c5, c6 ) && ((unsigned char *) s)[ 6 ] == c7 )
#define CMP8( s, c1, c2, c3, c4, c5, c6, c7, c8 ) \
  ( CMP7( s, c1, c2, c3, c4, c5, c6, c7 ) && ((unsigned char *) s)[ 7 ] == c8 )
#define CMP9( s, c1, c2, c3, c4, c5, c6, c7, c8, c9 ) \
  ( CMP8( s, c1, c2, c3, c4, c5, c6, c7, c8 ) && \
    ((unsigned char *) s)[ 8 ] == c9 )
#define CMP10( s, c1, c2, c3, c4, c5, c6, c7, c8, c9, c10 ) \
  ( CMP9( s, c1, c2, c3, c4, c5, c6, c7, c8, c9 ) && \
    ((unsigned char *) s)[ 9 ] == c10 )

#define SKIP(val) do {							\
    ctxt->nbChars += (val),ctxt->input->cur += (val),ctxt->input->col+=(val);			\
    if (*ctxt->input->cur == '%') xmlParserHandlePEReference(ctxt);	\
    if ((*ctxt->input->cur == 0) &&					\
        (xmlParserInputGrow(ctxt->input, INPUT_CHUNK) <= 0))		\