/src/libxml2/xmlregexp.c

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/*
 * regexp.c: generic and extensible Regular Expression engine
 *
 * Basically designed with the purpose of compiling regexps for
 * the variety of validation/schemas mechanisms now available in
 * XML related specifications these include:
 *    - XML-1.0 DTD validation
 *    - XML Schemas structure part 1
 *    - XML Schemas Datatypes part 2 especially Appendix F
 *    - RELAX-NG/TREX i.e. the counter proposal
 *
 * See Copyright for the status of this software.
 *
 * Daniel Veillard <veillard@redhat.com>
 */

#define IN_LIBXML
#include "libxml.h"

#ifdef LIBXML_REGEXP_ENABLED

/* #define DEBUG_ERR */

#include <stdio.h>
#include <string.h>
#include <limits.h>

#include <libxml/tree.h>
#include <libxml/parserInternals.h>
#include <libxml/xmlregexp.h>
#include <libxml/xmlautomata.h>
#include <libxml/xmlunicode.h>

#include "private/error.h"
#include "private/regexp.h"

#ifndef SIZE_MAX
#define SIZE_MAX ((size_t) -1)
#endif

/* #define DEBUG_REGEXP_GRAPH */
/* #define DEBUG_REGEXP_EXEC */
/* #define DEBUG_PUSH */
/* #define DEBUG_COMPACTION */

#define MAX_PUSH 10000000

#ifdef ERROR
#undef ERROR
#endif
#define ERROR(str)              \
    ctxt->error = XML_REGEXP_COMPILE_ERROR;       \
    xmlRegexpErrCompile(ctxt, str);
#define NEXT ctxt->cur++
#define CUR (*(ctxt->cur))
#define NXT(index) (ctxt->cur[index])

#define CUR_SCHAR(s, l) xmlStringCurrentChar(NULL, s, &l)
#define NEXTL(l) ctxt->cur += l;
#define XML_REG_STRING_SEPARATOR '|'
/*
 * Need PREV to check on a '-' within a Character Group. May only be used
 * when it's guaranteed that cur is not at the beginning of ctxt->string!
 */
#define PREV (ctxt->cur[-1])

/**
 * TODO:
 *
 * macro to flag unimplemented blocks
 */
#define TODO                \
    xmlGenericError(xmlGenericErrorContext,       \
      "Unimplemented block at %s:%d\n",       \
            __FILE__, __LINE__);

/************************************************************************
 *                  *
 *      Datatypes and structures      *
 *                  *
 ************************************************************************/

/*
 * Note: the order of the enums below is significant, do not shuffle
 */
typedef enum {
    XML_REGEXP_EPSILON = 1,
    XML_REGEXP_CHARVAL,
    XML_REGEXP_RANGES,
    XML_REGEXP_SUBREG,  /* used for () sub regexps */
    XML_REGEXP_STRING,
    XML_REGEXP_ANYCHAR, /* . */
    XML_REGEXP_ANYSPACE, /* \s */
    XML_REGEXP_NOTSPACE, /* \S */
    XML_REGEXP_INITNAME, /* \l */
    XML_REGEXP_NOTINITNAME, /* \L */
    XML_REGEXP_NAMECHAR, /* \c */
    XML_REGEXP_NOTNAMECHAR, /* \C */
    XML_REGEXP_DECIMAL, /* \d */
    XML_REGEXP_NOTDECIMAL, /* \D */
    XML_REGEXP_REALCHAR, /* \w */
    XML_REGEXP_NOTREALCHAR, /* \W */
    XML_REGEXP_LETTER = 100,
    XML_REGEXP_LETTER_UPPERCASE,
    XML_REGEXP_LETTER_LOWERCASE,
    XML_REGEXP_LETTER_TITLECASE,
    XML_REGEXP_LETTER_MODIFIER,
    XML_REGEXP_LETTER_OTHERS,
    XML_REGEXP_MARK,
    XML_REGEXP_MARK_NONSPACING,
    XML_REGEXP_MARK_SPACECOMBINING,
    XML_REGEXP_MARK_ENCLOSING,
    XML_REGEXP_NUMBER,
    XML_REGEXP_NUMBER_DECIMAL,
    XML_REGEXP_NUMBER_LETTER,
    XML_REGEXP_NUMBER_OTHERS,
    XML_REGEXP_PUNCT,
    XML_REGEXP_PUNCT_CONNECTOR,
    XML_REGEXP_PUNCT_DASH,
    XML_REGEXP_PUNCT_OPEN,
    XML_REGEXP_PUNCT_CLOSE,
    XML_REGEXP_PUNCT_INITQUOTE,
    XML_REGEXP_PUNCT_FINQUOTE,
    XML_REGEXP_PUNCT_OTHERS,
    XML_REGEXP_SEPAR,
    XML_REGEXP_SEPAR_SPACE,
    XML_REGEXP_SEPAR_LINE,
    XML_REGEXP_SEPAR_PARA,
    XML_REGEXP_SYMBOL,
    XML_REGEXP_SYMBOL_MATH,
    XML_REGEXP_SYMBOL_CURRENCY,
    XML_REGEXP_SYMBOL_MODIFIER,
    XML_REGEXP_SYMBOL_OTHERS,
    XML_REGEXP_OTHER,
    XML_REGEXP_OTHER_CONTROL,
    XML_REGEXP_OTHER_FORMAT,
    XML_REGEXP_OTHER_PRIVATE,
    XML_REGEXP_OTHER_NA,
    XML_REGEXP_BLOCK_NAME
} xmlRegAtomType;

typedef enum {
    XML_REGEXP_QUANT_EPSILON = 1,
    XML_REGEXP_QUANT_ONCE,
    XML_REGEXP_QUANT_OPT,
    XML_REGEXP_QUANT_MULT,
    XML_REGEXP_QUANT_PLUS,
    XML_REGEXP_QUANT_ONCEONLY,
    XML_REGEXP_QUANT_ALL,
    XML_REGEXP_QUANT_RANGE
} xmlRegQuantType;

typedef enum {
    XML_REGEXP_START_STATE = 1,
    XML_REGEXP_FINAL_STATE,
    XML_REGEXP_TRANS_STATE,
    XML_REGEXP_SINK_STATE,
    XML_REGEXP_UNREACH_STATE
} xmlRegStateType;

typedef enum {
    XML_REGEXP_MARK_NORMAL = 0,
    XML_REGEXP_MARK_START,
    XML_REGEXP_MARK_VISITED
} xmlRegMarkedType;

typedef struct _xmlRegRange xmlRegRange;
typedef xmlRegRange *xmlRegRangePtr;

struct _xmlRegRange {
    int neg;    /* 0 normal, 1 not, 2 exclude */
    xmlRegAtomType type;
    int start;
    int end;
    xmlChar *blockName;
};

typedef struct _xmlRegAtom xmlRegAtom;
typedef xmlRegAtom *xmlRegAtomPtr;

typedef struct _xmlAutomataState xmlRegState;
typedef xmlRegState *xmlRegStatePtr;

struct _xmlRegAtom {
    int no;
    xmlRegAtomType type;
    xmlRegQuantType quant;
    int min;
    int max;

    void *valuep;
    void *valuep2;
    int neg;
    int codepoint;
    xmlRegStatePtr start;
    xmlRegStatePtr start0;
    xmlRegStatePtr stop;
    int maxRanges;
    int nbRanges;
    xmlRegRangePtr *ranges;
    void *data;
};

typedef struct _xmlRegCounter xmlRegCounter;
typedef xmlRegCounter *xmlRegCounterPtr;

struct _xmlRegCounter {
    int min;
    int max;
};

typedef struct _xmlRegTrans xmlRegTrans;
typedef xmlRegTrans *xmlRegTransPtr;

struct _xmlRegTrans {
    xmlRegAtomPtr atom;
    int to;
    int counter;
    int count;
    int nd;
};

struct _xmlAutomataState {
    xmlRegStateType type;
    xmlRegMarkedType mark;
    xmlRegMarkedType markd;
    xmlRegMarkedType reached;
    int no;
    int maxTrans;
    int nbTrans;
    xmlRegTrans *trans;
    /*  knowing states pointing to us can speed things up */
    int maxTransTo;
    int nbTransTo;
    int *transTo;
};

typedef struct _xmlAutomata xmlRegParserCtxt;
typedef xmlRegParserCtxt *xmlRegParserCtxtPtr;

#define AM_AUTOMATA_RNG 1

struct _xmlAutomata {
    xmlChar *string;
    xmlChar *cur;

    int error;
    int neg;

    xmlRegStatePtr start;
    xmlRegStatePtr end;
    xmlRegStatePtr state;

    xmlRegAtomPtr atom;

    int maxAtoms;
    int nbAtoms;
    xmlRegAtomPtr *atoms;

    int maxStates;
    int nbStates;
    xmlRegStatePtr *states;

    int maxCounters;
    int nbCounters;
    xmlRegCounter *counters;

    int determinist;
    int negs;
    int flags;

    int depth;
};

struct _xmlRegexp {
    xmlChar *string;
    int nbStates;
    xmlRegStatePtr *states;
    int nbAtoms;
    xmlRegAtomPtr *atoms;
    int nbCounters;
    xmlRegCounter *counters;
    int determinist;
    int flags;
    /*
     * That's the compact form for determinists automatas
     */
    int nbstates;
    int *compact;
    void **transdata;
    int nbstrings;
    xmlChar **stringMap;
};

typedef struct _xmlRegExecRollback xmlRegExecRollback;
typedef xmlRegExecRollback *xmlRegExecRollbackPtr;

struct _xmlRegExecRollback {
    xmlRegStatePtr state;/* the current state */
    int index;    /* the index in the input stack */
    int nextbranch; /* the next transition to explore in that state */
    int *counts;  /* save the automata state if it has some */
};

typedef struct _xmlRegInputToken xmlRegInputToken;
typedef xmlRegInputToken *xmlRegInputTokenPtr;

struct _xmlRegInputToken {
    xmlChar *value;
    void *data;
};

struct _xmlRegExecCtxt {
    int status;   /* execution status != 0 indicate an error */
    int determinist;  /* did we find an indeterministic behaviour */
    xmlRegexpPtr comp;  /* the compiled regexp */
    xmlRegExecCallbacks callback;
    void *data;

    xmlRegStatePtr state;/* the current state */
    int transno;  /* the current transition on that state */
    int transcount; /* the number of chars in char counted transitions */

    /*
     * A stack of rollback states
     */
    int maxRollbacks;
    int nbRollbacks;
    xmlRegExecRollback *rollbacks;

    /*
     * The state of the automata if any
     */
    int *counts;

    /*
     * The input stack
     */
    int inputStackMax;
    int inputStackNr;
    int index;
    int *charStack;
    const xmlChar *inputString; /* when operating on characters */
    xmlRegInputTokenPtr inputStack;/* when operating on strings */

    /*
     * error handling
     */
    int errStateNo;   /* the error state number */
    xmlRegStatePtr errState;    /* the error state */
    xmlChar *errString;   /* the string raising the error */
    int *errCounts;   /* counters at the error state */
    int nbPush;
};

#define REGEXP_ALL_COUNTER  0x123456
#define REGEXP_ALL_LAX_COUNTER  0x123457

static void xmlFAParseRegExp(xmlRegParserCtxtPtr ctxt, int top);
static void xmlRegFreeState(xmlRegStatePtr state);
static void xmlRegFreeAtom(xmlRegAtomPtr atom);
static int xmlRegStrEqualWildcard(const xmlChar *expStr, const xmlChar *valStr);
static int xmlRegCheckCharacter(xmlRegAtomPtr atom, int codepoint);
static int xmlRegCheckCharacterRange(xmlRegAtomType type, int codepoint,
                  int neg, int start, int end, const xmlChar *blockName);

/************************************************************************
 *                  *
 *    Regexp memory error handler       *
 *                  *
 ************************************************************************/
/**
 * xmlRegexpErrMemory:
 * @extra:  extra information
 *
 * Handle an out of memory condition
 */
static void
xmlRegexpErrMemory(xmlRegParserCtxtPtr ctxt, const char *extra)
{
    const char *regexp = NULL;
    if (ctxt != NULL) {
        regexp = (const char *) ctxt->string;
  ctxt->error = XML_ERR_NO_MEMORY;
    }
    __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_REGEXP,
        XML_ERR_NO_MEMORY, XML_ERR_FATAL, NULL, 0, extra,
        regexp, NULL, 0, 0,
        "Memory allocation failed : %s\n", extra);
}

/**
 * xmlRegexpErrCompile:
 * @extra:  extra information
 *
 * Handle a compilation failure
 */
static void
xmlRegexpErrCompile(xmlRegParserCtxtPtr ctxt, const char *extra)
{
    const char *regexp = NULL;
    int idx = 0;

    if (ctxt != NULL) {
        regexp = (const char *) ctxt->string;
  idx = ctxt->cur - ctxt->string;
  ctxt->error = XML_REGEXP_COMPILE_ERROR;
    }
    __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_REGEXP,
        XML_REGEXP_COMPILE_ERROR, XML_ERR_FATAL, NULL, 0, extra,
        regexp, NULL, idx, 0,
        "failed to compile: %s\n", extra);
}

/************************************************************************
 *                  *
 *      Allocation/Deallocation       *
 *                  *
 ************************************************************************/

static int xmlFAComputesDeterminism(xmlRegParserCtxtPtr ctxt);

/**
 * xmlRegCalloc2:
 * @dim1:  size of first dimension
 * @dim2:  size of second dimension
 * @elemSize:  size of element
 *
 * Allocate a two-dimensional array and set all elements to zero.
 *
 * Returns the new array or NULL in case of error.
 */
static void*
xmlRegCalloc2(size_t dim1, size_t dim2, size_t elemSize) {
    size_t totalSize;
    void *ret;

    /* Check for overflow */
    if ((dim2 == 0) || (elemSize == 0) ||
        (dim1 > SIZE_MAX / dim2 / elemSize))
        return (NULL);
    totalSize = dim1 * dim2 * elemSize;
    ret = xmlMalloc(totalSize);
    if (ret != NULL)
        memset(ret, 0, totalSize);
    return (ret);
}

/**
 * xmlRegEpxFromParse:
 * @ctxt:  the parser context used to build it
 *
 * Allocate a new regexp and fill it with the result from the parser
 *
 * Returns the new regexp or NULL in case of error
 */
static xmlRegexpPtr
xmlRegEpxFromParse(xmlRegParserCtxtPtr ctxt) {
    xmlRegexpPtr ret;

    ret = (xmlRegexpPtr) xmlMalloc(sizeof(xmlRegexp));
    if (ret == NULL) {
  xmlRegexpErrMemory(ctxt, "compiling regexp");
  return(NULL);
    }
    memset(ret, 0, sizeof(xmlRegexp));
    ret->string = ctxt->string;
    ret->nbStates = ctxt->nbStates;
    ret->states = ctxt->states;
    ret->nbAtoms = ctxt->nbAtoms;
    ret->atoms = ctxt->atoms;
    ret->nbCounters = ctxt->nbCounters;
    ret->counters = ctxt->counters;
    ret->determinist = ctxt->determinist;
    ret->flags = ctxt->flags;
    if (ret->determinist == -1) {
        xmlRegexpIsDeterminist(ret);
    }

    if ((ret->determinist != 0) &&
  (ret->nbCounters == 0) &&
  (ctxt->negs == 0) &&
  (ret->atoms != NULL) &&
  (ret->atoms[0] != NULL) &&
  (ret->atoms[0]->type == XML_REGEXP_STRING)) {
  int i, j, nbstates = 0, nbatoms = 0;
  int *stateRemap;
  int *stringRemap;
  int *transitions;
  void **transdata;
  xmlChar **stringMap;
        xmlChar *value;

  /*
   * Switch to a compact representation
   * 1/ counting the effective number of states left
   * 2/ counting the unique number of atoms, and check that
   *    they are all of the string type
   * 3/ build a table state x atom for the transitions
   */

  stateRemap = xmlMalloc(ret->nbStates * sizeof(int));
  if (stateRemap == NULL) {
      xmlRegexpErrMemory(ctxt, "compiling regexp");
      xmlFree(ret);
      return(NULL);
  }
  for (i = 0;i < ret->nbStates;i++) {
      if (ret->states[i] != NULL) {
    stateRemap[i] = nbstates;
    nbstates++;
      } else {
    stateRemap[i] = -1;
      }
  }
#ifdef DEBUG_COMPACTION
  printf("Final: %d states\n", nbstates);
#endif
  stringMap = xmlMalloc(ret->nbAtoms * sizeof(char *));
  if (stringMap == NULL) {
      xmlRegexpErrMemory(ctxt, "compiling regexp");
      xmlFree(stateRemap);
      xmlFree(ret);
      return(NULL);
  }
  stringRemap = xmlMalloc(ret->nbAtoms * sizeof(int));
  if (stringRemap == NULL) {
      xmlRegexpErrMemory(ctxt, "compiling regexp");
      xmlFree(stringMap);
      xmlFree(stateRemap);
      xmlFree(ret);
      return(NULL);
  }
  for (i = 0;i < ret->nbAtoms;i++) {
      if ((ret->atoms[i]->type == XML_REGEXP_STRING) &&
    (ret->atoms[i]->quant == XML_REGEXP_QUANT_ONCE)) {
    value = ret->atoms[i]->valuep;
                for (j = 0;j < nbatoms;j++) {
        if (xmlStrEqual(stringMap[j], value)) {
      stringRemap[i] = j;
      break;
        }
    }
    if (j >= nbatoms) {
        stringRemap[i] = nbatoms;
        stringMap[nbatoms] = xmlStrdup(value);
        if (stringMap[nbatoms] == NULL) {
      for (i = 0;i < nbatoms;i++)
          xmlFree(stringMap[i]);
      xmlFree(stringRemap);
      xmlFree(stringMap);
      xmlFree(stateRemap);
      xmlFree(ret);
      return(NULL);
        }
        nbatoms++;
    }
      } else {
    xmlFree(stateRemap);
    xmlFree(stringRemap);
    for (i = 0;i < nbatoms;i++)
        xmlFree(stringMap[i]);
    xmlFree(stringMap);
    xmlFree(ret);
    return(NULL);
      }
  }
#ifdef DEBUG_COMPACTION
  printf("Final: %d atoms\n", nbatoms);
#endif
  transitions = (int *) xmlRegCalloc2(nbstates + 1, nbatoms + 1,
                                            sizeof(int));
  if (transitions == NULL) {
      xmlFree(stateRemap);
      xmlFree(stringRemap);
            for (i = 0;i < nbatoms;i++)
    xmlFree(stringMap[i]);
      xmlFree(stringMap);
      xmlFree(ret);
      return(NULL);
  }

  /*
   * Allocate the transition table. The first entry for each
   * state corresponds to the state type.
   */
  transdata = NULL;

  for (i = 0;i < ret->nbStates;i++) {
      int stateno, atomno, targetno, prev;
      xmlRegStatePtr state;
      xmlRegTransPtr trans;

      stateno = stateRemap[i];
      if (stateno == -1)
    continue;
      state = ret->states[i];

      transitions[stateno * (nbatoms + 1)] = state->type;

      for (j = 0;j < state->nbTrans;j++) {
    trans = &(state->trans[j]);
    if ((trans->to < 0) || (trans->atom == NULL))
        continue;
                atomno = stringRemap[trans->atom->no];
    if ((trans->atom->data != NULL) && (transdata == NULL)) {
        transdata = (void **) xmlRegCalloc2(nbstates, nbatoms,
                                      sizeof(void *));
        if (transdata == NULL) {
      xmlRegexpErrMemory(ctxt, "compiling regexp");
      break;
        }
    }
    targetno = stateRemap[trans->to];
    /*
     * if the same atom can generate transitions to 2 different
     * states then it means the automata is not deterministic and
     * the compact form can't be used !
     */
    prev = transitions[stateno * (nbatoms + 1) + atomno + 1];
    if (prev != 0) {
        if (prev != targetno + 1) {
      ret->determinist = 0;
#ifdef DEBUG_COMPACTION
      printf("Indet: state %d trans %d, atom %d to %d : %d to %d\n",
             i, j, trans->atom->no, trans->to, atomno, targetno);
      printf("       previous to is %d\n", prev);
#endif
      if (transdata != NULL)
          xmlFree(transdata);
      xmlFree(transitions);
      xmlFree(stateRemap);
      xmlFree(stringRemap);
      for (i = 0;i < nbatoms;i++)
          xmlFree(stringMap[i]);
      xmlFree(stringMap);
      goto not_determ;
        }
    } else {
#if 0
        printf("State %d trans %d: atom %d to %d : %d to %d\n",
         i, j, trans->atom->no, trans->to, atomno, targetno);
#endif
        transitions[stateno * (nbatoms + 1) + atomno + 1] =
      targetno + 1; /* to avoid 0 */
        if (transdata != NULL)
      transdata[stateno * nbatoms + atomno] =
          trans->atom->data;
    }
      }
  }
  ret->determinist = 1;
#ifdef DEBUG_COMPACTION
  /*
   * Debug
   */
  for (i = 0;i < nbstates;i++) {
      for (j = 0;j < nbatoms + 1;j++) {
                printf("%02d ", transitions[i * (nbatoms + 1) + j]);
      }
      printf("\n");
  }
  printf("\n");
#endif
  /*
   * Cleanup of the old data
   */
  if (ret->states != NULL) {
      for (i = 0;i < ret->nbStates;i++)
    xmlRegFreeState(ret->states[i]);
      xmlFree(ret->states);
  }
  ret->states = NULL;
  ret->nbStates = 0;
  if (ret->atoms != NULL) {
      for (i = 0;i < ret->nbAtoms;i++)
    xmlRegFreeAtom(ret->atoms[i]);
      xmlFree(ret->atoms);
  }
  ret->atoms = NULL;
  ret->nbAtoms = 0;

  ret->compact = transitions;
  ret->transdata = transdata;
  ret->stringMap = stringMap;
  ret->nbstrings = nbatoms;
  ret->nbstates = nbstates;
  xmlFree(stateRemap);
  xmlFree(stringRemap);
    }
not_determ:
    ctxt->string = NULL;
    ctxt->nbStates = 0;
    ctxt->states = NULL;
    ctxt->nbAtoms = 0;
    ctxt->atoms = NULL;
    ctxt->nbCounters = 0;
    ctxt->counters = NULL;
    return(ret);
}

/**
 * xmlRegNewParserCtxt:
 * @string:  the string to parse
 *
 * Allocate a new regexp parser context
 *
 * Returns the new context or NULL in case of error
 */
static xmlRegParserCtxtPtr
xmlRegNewParserCtxt(const xmlChar *string) {
    xmlRegParserCtxtPtr ret;

    ret = (xmlRegParserCtxtPtr) xmlMalloc(sizeof(xmlRegParserCtxt));
    if (ret == NULL)
  return(NULL);
    memset(ret, 0, sizeof(xmlRegParserCtxt));
    if (string != NULL)
  ret->string = xmlStrdup(string);
    ret->cur = ret->string;
    ret->neg = 0;
    ret->negs = 0;
    ret->error = 0;
    ret->determinist = -1;
    return(ret);
}

/**
 * xmlRegNewRange:
 * @ctxt:  the regexp parser context
 * @neg:  is that negative
 * @type:  the type of range
 * @start:  the start codepoint
 * @end:  the end codepoint
 *
 * Allocate a new regexp range
 *
 * Returns the new range or NULL in case of error
 */
static xmlRegRangePtr
xmlRegNewRange(xmlRegParserCtxtPtr ctxt,
         int neg, xmlRegAtomType type, int start, int end) {
    xmlRegRangePtr ret;

    ret = (xmlRegRangePtr) xmlMalloc(sizeof(xmlRegRange));
    if (ret == NULL) {
  xmlRegexpErrMemory(ctxt, "allocating range");
  return(NULL);
    }
    ret->neg = neg;
    ret->type = type;
    ret->start = start;
    ret->end = end;
    return(ret);
}

/**
 * xmlRegFreeRange:
 * @range:  the regexp range
 *
 * Free a regexp range
 */
static void
xmlRegFreeRange(xmlRegRangePtr range) {
    if (range == NULL)
  return;

    if (range->blockName != NULL)
  xmlFree(range->blockName);
    xmlFree(range);
}

/**
 * xmlRegCopyRange:
 * @range:  the regexp range
 *
 * Copy a regexp range
 *
 * Returns the new copy or NULL in case of error.
 */
static xmlRegRangePtr
xmlRegCopyRange(xmlRegParserCtxtPtr ctxt, xmlRegRangePtr range) {
    xmlRegRangePtr ret;

    if (range == NULL)
  return(NULL);

    ret = xmlRegNewRange(ctxt, range->neg, range->type, range->start,
                         range->end);
    if (ret == NULL)
        return(NULL);
    if (range->blockName != NULL) {
  ret->blockName = xmlStrdup(range->blockName);
  if (ret->blockName == NULL) {
      xmlRegexpErrMemory(ctxt, "allocating range");
      xmlRegFreeRange(ret);
      return(NULL);
  }
    }
    return(ret);
}

/**
 * xmlRegNewAtom:
 * @ctxt:  the regexp parser context
 * @type:  the type of atom
 *
 * Allocate a new atom
 *
 * Returns the new atom or NULL in case of error
 */
static xmlRegAtomPtr
xmlRegNewAtom(xmlRegParserCtxtPtr ctxt, xmlRegAtomType type) {
    xmlRegAtomPtr ret;

    ret = (xmlRegAtomPtr) xmlMalloc(sizeof(xmlRegAtom));
    if (ret == NULL) {
  xmlRegexpErrMemory(ctxt, "allocating atom");
  return(NULL);
    }
    memset(ret, 0, sizeof(xmlRegAtom));
    ret->type = type;
    ret->quant = XML_REGEXP_QUANT_ONCE;
    ret->min = 0;
    ret->max = 0;
    return(ret);
}

/**
 * xmlRegFreeAtom:
 * @atom:  the regexp atom
 *
 * Free a regexp atom
 */
static void
xmlRegFreeAtom(xmlRegAtomPtr atom) {
    int i;

    if (atom == NULL)
  return;

    for (i = 0;i < atom->nbRanges;i++)
  xmlRegFreeRange(atom->ranges[i]);
    if (atom->ranges != NULL)
  xmlFree(atom->ranges);
    if ((atom->type == XML_REGEXP_STRING) && (atom->valuep != NULL))
  xmlFree(atom->valuep);
    if ((atom->type == XML_REGEXP_STRING) && (atom->valuep2 != NULL))
  xmlFree(atom->valuep2);
    if ((atom->type == XML_REGEXP_BLOCK_NAME) && (atom->valuep != NULL))
  xmlFree(atom->valuep);
    xmlFree(atom);
}

/**
 * xmlRegCopyAtom:
 * @ctxt:  the regexp parser context
 * @atom:  the original atom
 *
 * Allocate a new regexp range
 *
 * Returns the new atom or NULL in case of error
 */
static xmlRegAtomPtr
xmlRegCopyAtom(xmlRegParserCtxtPtr ctxt, xmlRegAtomPtr atom) {
    xmlRegAtomPtr ret;

    ret = (xmlRegAtomPtr) xmlMalloc(sizeof(xmlRegAtom));
    if (ret == NULL) {
  xmlRegexpErrMemory(ctxt, "copying atom");
  return(NULL);
    }
    memset(ret, 0, sizeof(xmlRegAtom));
    ret->type = atom->type;
    ret->quant = atom->quant;
    ret->min = atom->min;
    ret->max = atom->max;
    if (atom->nbRanges > 0) {
        int i;

        ret->ranges = (xmlRegRangePtr *) xmlMalloc(sizeof(xmlRegRangePtr) *
                                             atom->nbRanges);
  if (ret->ranges == NULL) {
      xmlRegexpErrMemory(ctxt, "copying atom");
      goto error;
  }
  for (i = 0;i < atom->nbRanges;i++) {
      ret->ranges[i] = xmlRegCopyRange(ctxt, atom->ranges[i]);
      if (ret->ranges[i] == NULL)
          goto error;
      ret->nbRanges = i + 1;
  }
    }
    return(ret);

error:
    xmlRegFreeAtom(ret);
    return(NULL);
}

static xmlRegStatePtr
xmlRegNewState(xmlRegParserCtxtPtr ctxt) {
    xmlRegStatePtr ret;

    ret = (xmlRegStatePtr) xmlMalloc(sizeof(xmlRegState));
    if (ret == NULL) {
  xmlRegexpErrMemory(ctxt, "allocating state");
  return(NULL);
    }
    memset(ret, 0, sizeof(xmlRegState));
    ret->type = XML_REGEXP_TRANS_STATE;
    ret->mark = XML_REGEXP_MARK_NORMAL;
    return(ret);
}

/**
 * xmlRegFreeState:
 * @state:  the regexp state
 *
 * Free a regexp state
 */
static void
xmlRegFreeState(xmlRegStatePtr state) {
    if (state == NULL)
  return;

    if (state->trans != NULL)
  xmlFree(state->trans);
    if (state->transTo != NULL)
  xmlFree(state->transTo);
    xmlFree(state);
}

/**
 * xmlRegFreeParserCtxt:
 * @ctxt:  the regexp parser context
 *
 * Free a regexp parser context
 */
static void
xmlRegFreeParserCtxt(xmlRegParserCtxtPtr ctxt) {
    int i;
    if (ctxt == NULL)
  return;

    if (ctxt->string != NULL)
  xmlFree(ctxt->string);
    if (ctxt->states != NULL) {
  for (i = 0;i < ctxt->nbStates;i++)
      xmlRegFreeState(ctxt->states[i]);
  xmlFree(ctxt->states);
    }
    if (ctxt->atoms != NULL) {
  for (i = 0;i < ctxt->nbAtoms;i++)
      xmlRegFreeAtom(ctxt->atoms[i]);
  xmlFree(ctxt->atoms);
    }
    if (ctxt->counters != NULL)
  xmlFree(ctxt->counters);
    xmlFree(ctxt);
}

/************************************************************************
 *                  *
 *      Display of Data structures      *
 *                  *
 ************************************************************************/

static void
xmlRegPrintAtomType(FILE *output, xmlRegAtomType type) {
    switch (type) {
        case XML_REGEXP_EPSILON:
      fprintf(output, "epsilon "); break;
        case XML_REGEXP_CHARVAL:
      fprintf(output, "charval "); break;
        case XML_REGEXP_RANGES:
      fprintf(output, "ranges "); break;
        case XML_REGEXP_SUBREG:
      fprintf(output, "subexpr "); break;
        case XML_REGEXP_STRING:
      fprintf(output, "string "); break;
        case XML_REGEXP_ANYCHAR:
      fprintf(output, "anychar "); break;
        case XML_REGEXP_ANYSPACE:
      fprintf(output, "anyspace "); break;
        case XML_REGEXP_NOTSPACE:
      fprintf(output, "notspace "); break;
        case XML_REGEXP_INITNAME:
      fprintf(output, "initname "); break;
        case XML_REGEXP_NOTINITNAME:
      fprintf(output, "notinitname "); break;
        case XML_REGEXP_NAMECHAR:
      fprintf(output, "namechar "); break;
        case XML_REGEXP_NOTNAMECHAR:
      fprintf(output, "notnamechar "); break;
        case XML_REGEXP_DECIMAL:
      fprintf(output, "decimal "); break;
        case XML_REGEXP_NOTDECIMAL:
      fprintf(output, "notdecimal "); break;
        case XML_REGEXP_REALCHAR:
      fprintf(output, "realchar "); break;
        case XML_REGEXP_NOTREALCHAR:
      fprintf(output, "notrealchar "); break;
        case XML_REGEXP_LETTER:
            fprintf(output, "LETTER "); break;
        case XML_REGEXP_LETTER_UPPERCASE:
            fprintf(output, "LETTER_UPPERCASE "); break;
        case XML_REGEXP_LETTER_LOWERCASE:
            fprintf(output, "LETTER_LOWERCASE "); break;
        case XML_REGEXP_LETTER_TITLECASE:
            fprintf(output, "LETTER_TITLECASE "); break;
        case XML_REGEXP_LETTER_MODIFIER:
            fprintf(output, "LETTER_MODIFIER "); break;
        case XML_REGEXP_LETTER_OTHERS:
            fprintf(output, "LETTER_OTHERS "); break;
        case XML_REGEXP_MARK:
            fprintf(output, "MARK "); break;
        case XML_REGEXP_MARK_NONSPACING:
            fprintf(output, "MARK_NONSPACING "); break;
        case XML_REGEXP_MARK_SPACECOMBINING:
            fprintf(output, "MARK_SPACECOMBINING "); break;
        case XML_REGEXP_MARK_ENCLOSING:
            fprintf(output, "MARK_ENCLOSING "); break;
        case XML_REGEXP_NUMBER:
            fprintf(output, "NUMBER "); break;
        case XML_REGEXP_NUMBER_DECIMAL:
            fprintf(output, "NUMBER_DECIMAL "); break;
        case XML_REGEXP_NUMBER_LETTER:
            fprintf(output, "NUMBER_LETTER "); break;
        case XML_REGEXP_NUMBER_OTHERS:
            fprintf(output, "NUMBER_OTHERS "); break;
        case XML_REGEXP_PUNCT:
            fprintf(output, "PUNCT "); break;
        case XML_REGEXP_PUNCT_CONNECTOR:
            fprintf(output, "PUNCT_CONNECTOR "); break;
        case XML_REGEXP_PUNCT_DASH:
            fprintf(output, "PUNCT_DASH "); break;
        case XML_REGEXP_PUNCT_OPEN:
            fprintf(output, "PUNCT_OPEN "); break;
        case XML_REGEXP_PUNCT_CLOSE:
            fprintf(output, "PUNCT_CLOSE "); break;
        case XML_REGEXP_PUNCT_INITQUOTE:
            fprintf(output, "PUNCT_INITQUOTE "); break;
        case XML_REGEXP_PUNCT_FINQUOTE:
            fprintf(output, "PUNCT_FINQUOTE "); break;
        case XML_REGEXP_PUNCT_OTHERS:
            fprintf(output, "PUNCT_OTHERS "); break;
        case XML_REGEXP_SEPAR:
            fprintf(output, "SEPAR "); break;
        case XML_REGEXP_SEPAR_SPACE:
            fprintf(output, "SEPAR_SPACE "); break;
        case XML_REGEXP_SEPAR_LINE:
            fprintf(output, "SEPAR_LINE "); break;
        case XML_REGEXP_SEPAR_PARA:
            fprintf(output, "SEPAR_PARA "); break;
        case XML_REGEXP_SYMBOL:
            fprintf(output, "SYMBOL "); break;
        case XML_REGEXP_SYMBOL_MATH:
            fprintf(output, "SYMBOL_MATH "); break;
        case XML_REGEXP_SYMBOL_CURRENCY:
            fprintf(output, "SYMBOL_CURRENCY "); break;
        case XML_REGEXP_SYMBOL_MODIFIER:
            fprintf(output, "SYMBOL_MODIFIER "); break;
        case XML_REGEXP_SYMBOL_OTHERS:
            fprintf(output, "SYMBOL_OTHERS "); break;
        case XML_REGEXP_OTHER:
            fprintf(output, "OTHER "); break;
        case XML_REGEXP_OTHER_CONTROL:
            fprintf(output, "OTHER_CONTROL "); break;
        case XML_REGEXP_OTHER_FORMAT:
            fprintf(output, "OTHER_FORMAT "); break;
        case XML_REGEXP_OTHER_PRIVATE:
            fprintf(output, "OTHER_PRIVATE "); break;
        case XML_REGEXP_OTHER_NA:
            fprintf(output, "OTHER_NA "); break;
        case XML_REGEXP_BLOCK_NAME:
      fprintf(output, "BLOCK "); break;
    }
}

static void
xmlRegPrintQuantType(FILE *output, xmlRegQuantType type) {
    switch (type) {
        case XML_REGEXP_QUANT_EPSILON:
      fprintf(output, "epsilon "); break;
        case XML_REGEXP_QUANT_ONCE:
      fprintf(output, "once "); break;
        case XML_REGEXP_QUANT_OPT:
      fprintf(output, "? "); break;
        case XML_REGEXP_QUANT_MULT:
      fprintf(output, "* "); break;
        case XML_REGEXP_QUANT_PLUS:
      fprintf(output, "+ "); break;
  case XML_REGEXP_QUANT_RANGE:
      fprintf(output, "range "); break;
  case XML_REGEXP_QUANT_ONCEONLY:
      fprintf(output, "onceonly "); break;
  case XML_REGEXP_QUANT_ALL:
      fprintf(output, "all "); break;
    }
}
static void
xmlRegPrintRange(FILE *output, xmlRegRangePtr range) {
    fprintf(output, "  range: ");
    if (range->neg)
  fprintf(output, "negative ");
    xmlRegPrintAtomType(output, range->type);
    fprintf(output, "%c - %c\n", range->start, range->end);
}

static void
xmlRegPrintAtom(FILE *output, xmlRegAtomPtr atom) {
    fprintf(output, " atom: ");
    if (atom == NULL) {
  fprintf(output, "NULL\n");
  return;
    }
    if (atom->neg)
        fprintf(output, "not ");
    xmlRegPrintAtomType(output, atom->type);
    xmlRegPrintQuantType(output, atom->quant);
    if (atom->quant == XML_REGEXP_QUANT_RANGE)
  fprintf(output, "%d-%d ", atom->min, atom->max);
    if (atom->type == XML_REGEXP_STRING)
  fprintf(output, "'%s' ", (char *) atom->valuep);
    if (atom->type == XML_REGEXP_CHARVAL)
  fprintf(output, "char %c\n", atom->codepoint);
    else if (atom->type == XML_REGEXP_RANGES) {
  int i;
  fprintf(output, "%d entries\n", atom->nbRanges);
  for (i = 0; i < atom->nbRanges;i++)
      xmlRegPrintRange(output, atom->ranges[i]);
    } else if (atom->type == XML_REGEXP_SUBREG) {
  fprintf(output, "start %d end %d\n", atom->start->no, atom->stop->no);
    } else {
  fprintf(output, "\n");
    }
}

static void
xmlRegPrintTrans(FILE *output, xmlRegTransPtr trans) {
    fprintf(output, "  trans: ");
    if (trans == NULL) {
  fprintf(output, "NULL\n");
  return;
    }
    if (trans->to < 0) {
  fprintf(output, "removed\n");
  return;
    }
    if (trans->nd != 0) {
  if (trans->nd == 2)
      fprintf(output, "last not determinist, ");
  else
      fprintf(output, "not determinist, ");
    }
    if (trans->counter >= 0) {
  fprintf(output, "counted %d, ", trans->counter);
    }
    if (trans->count == REGEXP_ALL_COUNTER) {
  fprintf(output, "all transition, ");
    } else if (trans->count >= 0) {
  fprintf(output, "count based %d, ", trans->count);
    }
    if (trans->atom == NULL) {
  fprintf(output, "epsilon to %d\n", trans->to);
  return;
    }
    if (trans->atom->type == XML_REGEXP_CHARVAL)
  fprintf(output, "char %c ", trans->atom->codepoint);
    fprintf(output, "atom %d, to %d\n", trans->atom->no, trans->to);
}

static void
xmlRegPrintState(FILE *output, xmlRegStatePtr state) {
    int i;

    fprintf(output, " state: ");
    if (state == NULL) {
  fprintf(output, "NULL\n");
  return;
    }
    if (state->type == XML_REGEXP_START_STATE)
  fprintf(output, "START ");
    if (state->type == XML_REGEXP_FINAL_STATE)
  fprintf(output, "FINAL ");

    fprintf(output, "%d, %d transitions:\n", state->no, state->nbTrans);
    for (i = 0;i < state->nbTrans; i++) {
  xmlRegPrintTrans(output, &(state->trans[i]));
    }
}

#ifdef DEBUG_REGEXP_GRAPH
static void
xmlRegPrintCtxt(FILE *output, xmlRegParserCtxtPtr ctxt) {
    int i;

    fprintf(output, " ctxt: ");
    if (ctxt == NULL) {
  fprintf(output, "NULL\n");
  return;
    }
    fprintf(output, "'%s' ", ctxt->string);
    if (ctxt->error)
  fprintf(output, "error ");
    if (ctxt->neg)
  fprintf(output, "neg ");
    fprintf(output, "\n");
    fprintf(output, "%d atoms:\n", ctxt->nbAtoms);
    for (i = 0;i < ctxt->nbAtoms; i++) {
  fprintf(output, " %02d ", i);
  xmlRegPrintAtom(output, ctxt->atoms[i]);
    }
    if (ctxt->atom != NULL) {
  fprintf(output, "current atom:\n");
  xmlRegPrintAtom(output, ctxt->atom);
    }
    fprintf(output, "%d states:", ctxt->nbStates);
    if (ctxt->start != NULL)
  fprintf(output, " start: %d", ctxt->start->no);
    if (ctxt->end != NULL)
  fprintf(output, " end: %d", ctxt->end->no);
    fprintf(output, "\n");
    for (i = 0;i < ctxt->nbStates; i++) {
  xmlRegPrintState(output, ctxt->states[i]);
    }
    fprintf(output, "%d counters:\n", ctxt->nbCounters);
    for (i = 0;i < ctxt->nbCounters; i++) {
  fprintf(output, " %d: min %d max %d\n", i, ctxt->counters[i].min,
                                    ctxt->counters[i].max);
    }
}
#endif

/************************************************************************
 *                  *
 *     Finite Automata structures manipulations   *
 *                  *
 ************************************************************************/

static xmlRegRangePtr
xmlRegAtomAddRange(xmlRegParserCtxtPtr ctxt, xmlRegAtomPtr atom,
             int neg, xmlRegAtomType type, int start, int end,
       xmlChar *blockName) {
    xmlRegRangePtr range;

    if (atom == NULL) {
  ERROR("add range: atom is NULL");
  return(NULL);
    }
    if (atom->type != XML_REGEXP_RANGES) {
  ERROR("add range: atom is not ranges");
  return(NULL);
    }
    if (atom->maxRanges == 0) {
  atom->maxRanges = 4;
  atom->ranges = (xmlRegRangePtr *) xmlMalloc(atom->maxRanges *
                                 sizeof(xmlRegRangePtr));
  if (atom->ranges == NULL) {
      xmlRegexpErrMemory(ctxt, "adding ranges");
      atom->maxRanges = 0;
      return(NULL);
  }
    } else if (atom->nbRanges >= atom->maxRanges) {
  xmlRegRangePtr *tmp;
  atom->maxRanges *= 2;
  tmp = (xmlRegRangePtr *) xmlRealloc(atom->ranges, atom->maxRanges *
                                 sizeof(xmlRegRangePtr));
  if (tmp == NULL) {
      xmlRegexpErrMemory(ctxt, "adding ranges");
      atom->maxRanges /= 2;
      return(NULL);
  }
  atom->ranges = tmp;
    }
    range = xmlRegNewRange(ctxt, neg, type, start, end);
    if (range == NULL)
  return(NULL);
    range->blockName = blockName;
    atom->ranges[atom->nbRanges++] = range;

    return(range);
}

static int
xmlRegGetCounter(xmlRegParserCtxtPtr ctxt) {
    if (ctxt->maxCounters == 0) {
  ctxt->maxCounters = 4;
  ctxt->counters = (xmlRegCounter *) xmlMalloc(ctxt->maxCounters *
                                 sizeof(xmlRegCounter));
  if (ctxt->counters == NULL) {
      xmlRegexpErrMemory(ctxt, "allocating counter");
      ctxt->maxCounters = 0;
      return(-1);
  }
    } else if (ctxt->nbCounters >= ctxt->maxCounters) {
  xmlRegCounter *tmp;
  ctxt->maxCounters *= 2;
  tmp = (xmlRegCounter *) xmlRealloc(ctxt->counters, ctxt->maxCounters *
                               sizeof(xmlRegCounter));
  if (tmp == NULL) {
      xmlRegexpErrMemory(ctxt, "allocating counter");
      ctxt->maxCounters /= 2;
      return(-1);
  }
  ctxt->counters = tmp;
    }
    ctxt->counters[ctxt->nbCounters].min = -1;
    ctxt->counters[ctxt->nbCounters].max = -1;
    return(ctxt->nbCounters++);
}

static int
xmlRegAtomPush(xmlRegParserCtxtPtr ctxt, xmlRegAtomPtr atom) {
    if (atom == NULL) {
  ERROR("atom push: atom is NULL");
  return(-1);
    }
    if (ctxt->nbAtoms >= ctxt->maxAtoms) {
        size_t newSize = ctxt->maxAtoms ? ctxt->maxAtoms * 2 : 4;
  xmlRegAtomPtr *tmp;

  tmp = xmlRealloc(ctxt->atoms, newSize * sizeof(xmlRegAtomPtr));
  if (tmp == NULL) {
      xmlRegexpErrMemory(ctxt, "allocating counter");
      return(-1);
  }
  ctxt->atoms = tmp;
        ctxt->maxAtoms = newSize;
    }
    atom->no = ctxt->nbAtoms;
    ctxt->atoms[ctxt->nbAtoms++] = atom;
    return(0);
}

static void
xmlRegStateAddTransTo(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr target,
                      int from) {
    if (target->maxTransTo == 0) {
  target->maxTransTo = 8;
  target->transTo = (int *) xmlMalloc(target->maxTransTo *
                                 sizeof(int));
  if (target->transTo == NULL) {
      xmlRegexpErrMemory(ctxt, "adding transition");
      target->maxTransTo = 0;
      return;
  }
    } else if (target->nbTransTo >= target->maxTransTo) {
  int *tmp;
  target->maxTransTo *= 2;
  tmp = (int *) xmlRealloc(target->transTo, target->maxTransTo *
                                 sizeof(int));
  if (tmp == NULL) {
      xmlRegexpErrMemory(ctxt, "adding transition");
      target->maxTransTo /= 2;
      return;
  }
  target->transTo = tmp;
    }
    target->transTo[target->nbTransTo] = from;
    target->nbTransTo++;
}

static void
xmlRegStateAddTrans(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr state,
              xmlRegAtomPtr atom, xmlRegStatePtr target,
        int counter, int count) {

    int nrtrans;

    if (state == NULL) {
  ERROR("add state: state is NULL");
  return;
    }
    if (target == NULL) {
  ERROR("add state: target is NULL");
  return;
    }
    /*
     * Other routines follow the philosophy 'When in doubt, add a transition'
     * so we check here whether such a transition is already present and, if
     * so, silently ignore this request.
     */

    for (nrtrans = state->nbTrans - 1; nrtrans >= 0; nrtrans--) {
  xmlRegTransPtr trans = &(state->trans[nrtrans]);
  if ((trans->atom == atom) &&
      (trans->to == target->no) &&
      (trans->counter == counter) &&
      (trans->count == count)) {
#ifdef DEBUG_REGEXP_GRAPH
      printf("Ignoring duplicate transition from %d to %d\n",
        state->no, target->no);
#endif
      return;
  }
    }

    if (state->maxTrans == 0) {
  state->maxTrans = 8;
  state->trans = (xmlRegTrans *) xmlMalloc(state->maxTrans *
                                 sizeof(xmlRegTrans));
  if (state->trans == NULL) {
      xmlRegexpErrMemory(ctxt, "adding transition");
      state->maxTrans = 0;
      return;
  }
    } else if (state->nbTrans >= state->maxTrans) {
  xmlRegTrans *tmp;
  state->maxTrans *= 2;
  tmp = (xmlRegTrans *) xmlRealloc(state->trans, state->maxTrans *
                                 sizeof(xmlRegTrans));
  if (tmp == NULL) {
      xmlRegexpErrMemory(ctxt, "adding transition");
      state->maxTrans /= 2;
      return;
  }
  state->trans = tmp;
    }
#ifdef DEBUG_REGEXP_GRAPH
    printf("Add trans from %d to %d ", state->no, target->no);
    if (count == REGEXP_ALL_COUNTER)
  printf("all transition\n");
    else if (count >= 0)
  printf("count based %d\n", count);
    else if (counter >= 0)
  printf("counted %d\n", counter);
    else if (atom == NULL)
  printf("epsilon transition\n");
    else if (atom != NULL)
        xmlRegPrintAtom(stdout, atom);
#endif

    state->trans[state->nbTrans].atom = atom;
    state->trans[state->nbTrans].to = target->no;
    state->trans[state->nbTrans].counter = counter;
    state->trans[state->nbTrans].count = count;
    state->trans[state->nbTrans].nd = 0;
    state->nbTrans++;
    xmlRegStateAddTransTo(ctxt, target, state->no);
}

static xmlRegStatePtr
xmlRegStatePush(xmlRegParserCtxtPtr ctxt) {
    xmlRegStatePtr state;

    if (ctxt->nbStates >= ctxt->maxStates) {
        size_t newSize = ctxt->maxStates ? ctxt->maxStates * 2 : 4;
  xmlRegStatePtr *tmp;

  tmp = xmlRealloc(ctxt->states, newSize * sizeof(tmp[0]));
  if (tmp == NULL) {
      xmlRegexpErrMemory(ctxt, "adding state");
      return(NULL);
  }
  ctxt->states = tmp;
  ctxt->maxStates = newSize;
    }

    state = xmlRegNewState(ctxt);
    if (state == NULL)
        return(NULL);

    state->no = ctxt->nbStates;
    ctxt->states[ctxt->nbStates++] = state;

    return(state);
}

/**
 * xmlFAGenerateAllTransition:
 * @ctxt:  a regexp parser context
 * @from:  the from state
 * @to:  the target state or NULL for building a new one
 * @lax:
 *
 */
static int
xmlFAGenerateAllTransition(xmlRegParserCtxtPtr ctxt,
         xmlRegStatePtr from, xmlRegStatePtr to,
         int lax) {
    if (to == NULL) {
  to = xmlRegStatePush(ctxt);
        if (to == NULL)
            return(-1);
  ctxt->state = to;
    }
    if (lax)
  xmlRegStateAddTrans(ctxt, from, NULL, to, -1, REGEXP_ALL_LAX_COUNTER);
    else
  xmlRegStateAddTrans(ctxt, from, NULL, to, -1, REGEXP_ALL_COUNTER);
    return(0);
}

/**
 * xmlFAGenerateEpsilonTransition:
 * @ctxt:  a regexp parser context
 * @from:  the from state
 * @to:  the target state or NULL for building a new one
 *
 */
static int
xmlFAGenerateEpsilonTransition(xmlRegParserCtxtPtr ctxt,
             xmlRegStatePtr from, xmlRegStatePtr to) {
    if (to == NULL) {
  to = xmlRegStatePush(ctxt);
        if (to == NULL)
            return(-1);
  ctxt->state = to;
    }
    xmlRegStateAddTrans(ctxt, from, NULL, to, -1, -1);
    return(0);
}

/**
 * xmlFAGenerateCountedEpsilonTransition:
 * @ctxt:  a regexp parser context
 * @from:  the from state
 * @to:  the target state or NULL for building a new one
 * counter:  the counter for that transition
 *
 */
static int
xmlFAGenerateCountedEpsilonTransition(xmlRegParserCtxtPtr ctxt,
      xmlRegStatePtr from, xmlRegStatePtr to, int counter) {
    if (to == NULL) {
  to = xmlRegStatePush(ctxt);
        if (to == NULL)
            return(-1);
  ctxt->state = to;
    }
    xmlRegStateAddTrans(ctxt, from, NULL, to, counter, -1);
    return(0);
}

/**
 * xmlFAGenerateCountedTransition:
 * @ctxt:  a regexp parser context
 * @from:  the from state
 * @to:  the target state or NULL for building a new one
 * counter:  the counter for that transition
 *
 */
static int
xmlFAGenerateCountedTransition(xmlRegParserCtxtPtr ctxt,
      xmlRegStatePtr from, xmlRegStatePtr to, int counter) {
    if (to == NULL) {
  to = xmlRegStatePush(ctxt);
        if (to == NULL)
            return(-1);
  ctxt->state = to;
    }
    xmlRegStateAddTrans(ctxt, from, NULL, to, -1, counter);
    return(0);
}

/**
 * xmlFAGenerateTransitions:
 * @ctxt:  a regexp parser context
 * @from:  the from state
 * @to:  the target state or NULL for building a new one
 * @atom:  the atom generating the transition
 *
 * Returns 0 if success and -1 in case of error.
 */
static int
xmlFAGenerateTransitions(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr from,
                   xmlRegStatePtr to, xmlRegAtomPtr atom) {
    xmlRegStatePtr end;
    int nullable = 0;

    if (atom == NULL) {
  ERROR("generate transition: atom == NULL");
  return(-1);
    }
    if (atom->type == XML_REGEXP_SUBREG) {
  /*
   * this is a subexpression handling one should not need to
   * create a new node except for XML_REGEXP_QUANT_RANGE.
   */
  if ((to != NULL) && (atom->stop != to) &&
      (atom->quant != XML_REGEXP_QUANT_RANGE)) {
      /*
       * Generate an epsilon transition to link to the target
       */
      xmlFAGenerateEpsilonTransition(ctxt, atom->stop, to);
#ifdef DV
  } else if ((to == NULL) && (atom->quant != XML_REGEXP_QUANT_RANGE) &&
       (atom->quant != XML_REGEXP_QUANT_ONCE)) {
      to = xmlRegStatePush(ctxt, to);
            if (to == NULL)
                return(-1);
      ctxt->state = to;
      xmlFAGenerateEpsilonTransition(ctxt, atom->stop, to);
#endif
  }
  switch (atom->quant) {
      case XML_REGEXP_QUANT_OPT:
    atom->quant = XML_REGEXP_QUANT_ONCE;
    /*
     * transition done to the state after end of atom.
     *      1. set transition from atom start to new state
     *      2. set transition from atom end to this state.
     */
                if (to == NULL) {
                    xmlFAGenerateEpsilonTransition(ctxt, atom->start, 0);
                    xmlFAGenerateEpsilonTransition(ctxt, atom->stop,
                                                   ctxt->state);
                } else {
                    xmlFAGenerateEpsilonTransition(ctxt, atom->start, to);
                }
    break;
      case XML_REGEXP_QUANT_MULT:
    atom->quant = XML_REGEXP_QUANT_ONCE;
    xmlFAGenerateEpsilonTransition(ctxt, atom->start, atom->stop);
    xmlFAGenerateEpsilonTransition(ctxt, atom->stop, atom->start);
    break;
      case XML_REGEXP_QUANT_PLUS:
    atom->quant = XML_REGEXP_QUANT_ONCE;
    xmlFAGenerateEpsilonTransition(ctxt, atom->stop, atom->start);
    break;
      case XML_REGEXP_QUANT_RANGE: {
    int counter;
    xmlRegStatePtr inter, newstate;

    /*
     * create the final state now if needed
     */
    if (to != NULL) {
        newstate = to;
    } else {
        newstate = xmlRegStatePush(ctxt);
                    if (newstate == NULL)
                        return(-1);
    }

    /*
     * The principle here is to use counted transition
     * to avoid explosion in the number of states in the
     * graph. This is clearly more complex but should not
     * be exploitable at runtime.
     */
    if ((atom->min == 0) && (atom->start0 == NULL)) {
        xmlRegAtomPtr copy;
        /*
         * duplicate a transition based on atom to count next
         * occurrences after 1. We cannot loop to atom->start
         * directly because we need an epsilon transition to
         * newstate.
         */
         /* ???? For some reason it seems we never reach that
            case, I suppose this got optimized out before when
      building the automata */
        copy = xmlRegCopyAtom(ctxt, atom);
        if (copy == NULL)
            return(-1);
        copy->quant = XML_REGEXP_QUANT_ONCE;
        copy->min = 0;
        copy->max = 0;

        if (xmlFAGenerateTransitions(ctxt, atom->start, NULL, copy)
            < 0) {
                        xmlRegFreeAtom(copy);
      return(-1);
                    }
        inter = ctxt->state;
        counter = xmlRegGetCounter(ctxt);
                    if (counter < 0)
                        return(-1);
        ctxt->counters[counter].min = atom->min - 1;
        ctxt->counters[counter].max = atom->max - 1;
        /* count the number of times we see it again */
        xmlFAGenerateCountedEpsilonTransition(ctxt, inter,
               atom->stop, counter);
        /* allow a way out based on the count */
        xmlFAGenerateCountedTransition(ctxt, inter,
                                 newstate, counter);
        /* and also allow a direct exit for 0 */
        xmlFAGenerateEpsilonTransition(ctxt, atom->start,
                                       newstate);
    } else {
        /*
         * either we need the atom at least once or there
         * is an atom->start0 allowing to easily plug the
         * epsilon transition.
         */
        counter = xmlRegGetCounter(ctxt);
                    if (counter < 0)
                        return(-1);
        ctxt->counters[counter].min = atom->min - 1;
        ctxt->counters[counter].max = atom->max - 1;
        /* allow a way out based on the count */
        xmlFAGenerateCountedTransition(ctxt, atom->stop,
                                 newstate, counter);
        /* count the number of times we see it again */
        xmlFAGenerateCountedEpsilonTransition(ctxt, atom->stop,
               atom->start, counter);
        /* and if needed allow a direct exit for 0 */
        if (atom->min == 0)
      xmlFAGenerateEpsilonTransition(ctxt, atom->start0,
                   newstate);

    }
    atom->min = 0;
    atom->max = 0;
    atom->quant = XML_REGEXP_QUANT_ONCE;
    ctxt->state = newstate;
      }
      default:
    break;
  }
  if (xmlRegAtomPush(ctxt, atom) < 0)
      return(-1);
  return(0);
    }
    if ((atom->min == 0) && (atom->max == 0) &&
               (atom->quant == XML_REGEXP_QUANT_RANGE)) {
        /*
   * we can discard the atom and generate an epsilon transition instead
   */
  if (to == NULL) {
      to = xmlRegStatePush(ctxt);
      if (to == NULL)
    return(-1);
  }
  xmlFAGenerateEpsilonTransition(ctxt, from, to);
  ctxt->state = to;
  xmlRegFreeAtom(atom);
  return(0);
    }
    if (to == NULL) {
  to = xmlRegStatePush(ctxt);
  if (to == NULL)
      return(-1);
    }
    end = to;
    if ((atom->quant == XML_REGEXP_QUANT_MULT) ||
        (atom->quant == XML_REGEXP_QUANT_PLUS)) {
  /*
   * Do not pollute the target state by adding transitions from
   * it as it is likely to be the shared target of multiple branches.
   * So isolate with an epsilon transition.
   */
        xmlRegStatePtr tmp;

  tmp = xmlRegStatePush(ctxt);
        if (tmp == NULL)
      return(-1);
  xmlFAGenerateEpsilonTransition(ctxt, tmp, to);
  to = tmp;
    }
    if ((atom->quant == XML_REGEXP_QUANT_RANGE) &&
        (atom->min == 0) && (atom->max > 0)) {
  nullable = 1;
  atom->min = 1;
        if (atom->max == 1)
      atom->quant = XML_REGEXP_QUANT_OPT;
    }
    xmlRegStateAddTrans(ctxt, from, atom, to, -1, -1);
    ctxt->state = end;
    switch (atom->quant) {
  case XML_REGEXP_QUANT_OPT:
      atom->quant = XML_REGEXP_QUANT_ONCE;
      xmlFAGenerateEpsilonTransition(ctxt, from, to);
      break;
  case XML_REGEXP_QUANT_MULT:
      atom->quant = XML_REGEXP_QUANT_ONCE;
      xmlFAGenerateEpsilonTransition(ctxt, from, to);
      xmlRegStateAddTrans(ctxt, to, atom, to, -1, -1);
      break;
  case XML_REGEXP_QUANT_PLUS:
      atom->quant = XML_REGEXP_QUANT_ONCE;
      xmlRegStateAddTrans(ctxt, to, atom, to, -1, -1);
      break;
  case XML_REGEXP_QUANT_RANGE:
      if (nullable)
    xmlFAGenerateEpsilonTransition(ctxt, from, to);
      break;
  default:
      break;
    }
    if (xmlRegAtomPush(ctxt, atom) < 0)
  return(-1);
    return(0);
}

/**
 * xmlFAReduceEpsilonTransitions:
 * @ctxt:  a regexp parser context
 * @fromnr:  the from state
 * @tonr:  the to state
 * @counter:  should that transition be associated to a counted
 *
 */
static void
xmlFAReduceEpsilonTransitions(xmlRegParserCtxtPtr ctxt, int fromnr,
                        int tonr, int counter) {
    int transnr;
    xmlRegStatePtr from;
    xmlRegStatePtr to;

#ifdef DEBUG_REGEXP_GRAPH
    printf("xmlFAReduceEpsilonTransitions(%d, %d)\n", fromnr, tonr);
#endif
    from = ctxt->states[fromnr];
    if (from == NULL)
  return;
    to = ctxt->states[tonr];
    if (to == NULL)
  return;
    if ((to->mark == XML_REGEXP_MARK_START) ||
  (to->mark == XML_REGEXP_MARK_VISITED))
  return;

    to->mark = XML_REGEXP_MARK_VISITED;
    if (to->type == XML_REGEXP_FINAL_STATE) {
#ifdef DEBUG_REGEXP_GRAPH
  printf("State %d is final, so %d becomes final\n", tonr, fromnr);
#endif
  from->type = XML_REGEXP_FINAL_STATE;
    }
    for (transnr = 0;transnr < to->nbTrans;transnr++) {
        xmlRegTransPtr t1 = &to->trans[transnr];
        int tcounter;

        if (t1->to < 0)
      continue;
        if (t1->counter >= 0) {
            /* assert(counter < 0); */
            tcounter = t1->counter;
        } else {
            tcounter = counter;
        }
  if (t1->atom == NULL) {
      /*
       * Don't remove counted transitions
       * Don't loop either
       */
      if (t1->to != fromnr) {
    if (t1->count >= 0) {
        xmlRegStateAddTrans(ctxt, from, NULL, ctxt->states[t1->to],
          -1, t1->count);
    } else {
#ifdef DEBUG_REGEXP_GRAPH
        printf("Found epsilon trans %d from %d to %d\n",
         transnr, tonr, t1->to);
#endif
                    xmlFAReduceEpsilonTransitions(ctxt, fromnr, t1->to,
                                                  tcounter);
    }
      }
  } else {
            xmlRegStateAddTrans(ctxt, from, t1->atom,
                                ctxt->states[t1->to], tcounter, -1);
  }
    }
}

/**
 * xmlFAFinishReduceEpsilonTransitions:
 * @ctxt:  a regexp parser context
 * @fromnr:  the from state
 * @tonr:  the to state
 * @counter:  should that transition be associated to a counted
 *
 */
static void
xmlFAFinishReduceEpsilonTransitions(xmlRegParserCtxtPtr ctxt, int tonr) {
    int transnr;
    xmlRegStatePtr to;

    to = ctxt->states[tonr];
    if (to == NULL)
  return;
    if ((to->mark == XML_REGEXP_MARK_START) ||
  (to->mark == XML_REGEXP_MARK_NORMAL))
  return;

    to->mark = XML_REGEXP_MARK_NORMAL;
    for (transnr = 0;transnr < to->nbTrans;transnr++) {
  xmlRegTransPtr t1 = &to->trans[transnr];
  if ((t1->to >= 0) && (t1->atom == NULL))
            xmlFAFinishReduceEpsilonTransitions(ctxt, t1->to);
    }
}

/**
 * xmlFAEliminateSimpleEpsilonTransitions:
 * @ctxt:  a regexp parser context
 *
 * Eliminating general epsilon transitions can get costly in the general
 * algorithm due to the large amount of generated new transitions and
 * associated comparisons. However for simple epsilon transition used just
 * to separate building blocks when generating the automata this can be
 * reduced to state elimination:
 *    - if there exists an epsilon from X to Y
 *    - if there is no other transition from X
 * then X and Y are semantically equivalent and X can be eliminated
 * If X is the start state then make Y the start state, else replace the
 * target of all transitions to X by transitions to Y.
 *
 * If X is a final state, skip it.
 * Otherwise it would be necessary to manipulate counters for this case when
 * eliminating state 2:
 * State 1 has a transition with an atom to state 2.
 * State 2 is final and has an epsilon transition to state 1.
 */
static void
xmlFAEliminateSimpleEpsilonTransitions(xmlRegParserCtxtPtr ctxt) {
    int statenr, i, j, newto;
    xmlRegStatePtr state, tmp;

    for (statenr = 0;statenr < ctxt->nbStates;statenr++) {
  state = ctxt->states[statenr];
  if (state == NULL)
      continue;
  if (state->nbTrans != 1)
      continue;
       if (state->type == XML_REGEXP_UNREACH_STATE ||
           state->type == XML_REGEXP_FINAL_STATE)
      continue;
  /* is the only transition out a basic transition */
  if ((state->trans[0].atom == NULL) &&
      (state->trans[0].to >= 0) &&
      (state->trans[0].to != statenr) &&
      (state->trans[0].counter < 0) &&
      (state->trans[0].count < 0)) {
      newto = state->trans[0].to;

            if (state->type == XML_REGEXP_START_STATE) {
#ifdef DEBUG_REGEXP_GRAPH
    printf("Found simple epsilon trans from start %d to %d\n",
           statenr, newto);
#endif
            } else {
#ifdef DEBUG_REGEXP_GRAPH
    printf("Found simple epsilon trans from %d to %d\n",
           statenr, newto);
#endif
          for (i = 0;i < state->nbTransTo;i++) {
        tmp = ctxt->states[state->transTo[i]];
        for (j = 0;j < tmp->nbTrans;j++) {
      if (tmp->trans[j].to == statenr) {
#ifdef DEBUG_REGEXP_GRAPH
          printf("Changed transition %d on %d to go to %d\n",
           j, tmp->no, newto);
#endif
          tmp->trans[j].to = -1;
          xmlRegStateAddTrans(ctxt, tmp, tmp->trans[j].atom,
            ctxt->states[newto],
                  tmp->trans[j].counter,
            tmp->trans[j].count);
      }
        }
    }
    if (state->type == XML_REGEXP_FINAL_STATE)
        ctxt->states[newto]->type = XML_REGEXP_FINAL_STATE;
    /* eliminate the transition completely */
    state->nbTrans = 0;

                state->type = XML_REGEXP_UNREACH_STATE;

      }

  }
    }
}
/**
 * xmlFAEliminateEpsilonTransitions:
 * @ctxt:  a regexp parser context
 *
 */
static void
xmlFAEliminateEpsilonTransitions(xmlRegParserCtxtPtr ctxt) {
    int statenr, transnr;
    xmlRegStatePtr state;
    int has_epsilon;

    if (ctxt->states == NULL) return;

    /*
     * Eliminate simple epsilon transition and the associated unreachable
     * states.
     */
    xmlFAEliminateSimpleEpsilonTransitions(ctxt);
    for (statenr = 0;statenr < ctxt->nbStates;statenr++) {
  state = ctxt->states[statenr];
  if ((state != NULL) && (state->type == XML_REGEXP_UNREACH_STATE)) {
#ifdef DEBUG_REGEXP_GRAPH
      printf("Removed unreachable state %d\n", statenr);
#endif
      xmlRegFreeState(state);
      ctxt->states[statenr] = NULL;
  }
    }

    has_epsilon = 0;

    /*
     * Build the completed transitions bypassing the epsilons
     * Use a marking algorithm to avoid loops
     * Mark sink states too.
     * Process from the latest states backward to the start when
     * there is long cascading epsilon chains this minimize the
     * recursions and transition compares when adding the new ones
     */
    for (statenr = ctxt->nbStates - 1;statenr >= 0;statenr--) {
  state = ctxt->states[statenr];
  if (state == NULL)
      continue;
  if ((state->nbTrans == 0) &&
      (state->type != XML_REGEXP_FINAL_STATE)) {
      state->type = XML_REGEXP_SINK_STATE;
  }
  for (transnr = 0;transnr < state->nbTrans;transnr++) {
      if ((state->trans[transnr].atom == NULL) &&
    (state->trans[transnr].to >= 0)) {
    if (state->trans[transnr].to == statenr) {
        state->trans[transnr].to = -1;
#ifdef DEBUG_REGEXP_GRAPH
        printf("Removed loopback epsilon trans %d on %d\n",
         transnr, statenr);
#endif
    } else if (state->trans[transnr].count < 0) {
        int newto = state->trans[transnr].to;

#ifdef DEBUG_REGEXP_GRAPH
        printf("Found epsilon trans %d from %d to %d\n",
         transnr, statenr, newto);
#endif
        has_epsilon = 1;
        state->trans[transnr].to = -2;
        state->mark = XML_REGEXP_MARK_START;
        xmlFAReduceEpsilonTransitions(ctxt, statenr,
              newto, state->trans[transnr].counter);
        xmlFAFinishReduceEpsilonTransitions(ctxt, newto);
        state->mark = XML_REGEXP_MARK_NORMAL;
#ifdef DEBUG_REGEXP_GRAPH
    } else {
        printf("Found counted transition %d on %d\n",
         transnr, statenr);
#endif
          }
      }
  }
    }
    /*
     * Eliminate the epsilon transitions
     */
    if (has_epsilon) {
  for (statenr = 0;statenr < ctxt->nbStates;statenr++) {
      state = ctxt->states[statenr];
      if (state == NULL)
    continue;
      for (transnr = 0;transnr < state->nbTrans;transnr++) {
    xmlRegTransPtr trans = &(state->trans[transnr]);
    if ((trans->atom == NULL) &&
        (trans->count < 0) &&
        (trans->to >= 0)) {
        trans->to = -1;
    }
      }
  }
    }

    /*
     * Use this pass to detect unreachable states too
     */
    for (statenr = 0;statenr < ctxt->nbStates;statenr++) {
  state = ctxt->states[statenr];
  if (state != NULL)
      state->reached = XML_REGEXP_MARK_NORMAL;
    }
    state = ctxt->states[0];
    if (state != NULL)
  state->reached = XML_REGEXP_MARK_START;
    while (state != NULL) {
  xmlRegStatePtr target = NULL;
  state->reached = XML_REGEXP_MARK_VISITED;
  /*
   * Mark all states reachable from the current reachable state
   */
  for (transnr = 0;transnr < state->nbTrans;transnr++) {
      if ((state->trans[transnr].to >= 0) &&
    ((state->trans[transnr].atom != NULL) ||
     (state->trans[transnr].count >= 0))) {
    int newto = state->trans[transnr].to;

    if (ctxt->states[newto] == NULL)
        continue;
    if (ctxt->states[newto]->reached == XML_REGEXP_MARK_NORMAL) {
        ctxt->states[newto]->reached = XML_REGEXP_MARK_START;
        target = ctxt->states[newto];
    }
      }
  }

  /*
   * find the next accessible state not explored
   */
  if (target == NULL) {
      for (statenr = 1;statenr < ctxt->nbStates;statenr++) {
    state = ctxt->states[statenr];
    if ((state != NULL) && (state->reached ==
      XML_REGEXP_MARK_START)) {
        target = state;
        break;
    }
      }
  }
  state = target;
    }
    for (statenr = 0;statenr < ctxt->nbStates;statenr++) {
  state = ctxt->states[statenr];
  if ((state != NULL) && (state->reached == XML_REGEXP_MARK_NORMAL)) {
#ifdef DEBUG_REGEXP_GRAPH
      printf("Removed unreachable state %d\n", statenr);
#endif
      xmlRegFreeState(state);
      ctxt->states[statenr] = NULL;
  }
    }

}

static int
xmlFACompareRanges(xmlRegRangePtr range1, xmlRegRangePtr range2) {
    int ret = 0;

    if ((range1->type == XML_REGEXP_RANGES) ||
        (range2->type == XML_REGEXP_RANGES) ||
        (range2->type == XML_REGEXP_SUBREG) ||
        (range1->type == XML_REGEXP_SUBREG) ||
        (range1->type == XML_REGEXP_STRING) ||
        (range2->type == XML_REGEXP_STRING))
  return(-1);

    /* put them in order */
    if (range1->type > range2->type) {
        xmlRegRangePtr tmp;

  tmp = range1;
  range1 = range2;
  range2 = tmp;
    }
    if ((range1->type == XML_REGEXP_ANYCHAR) ||
        (range2->type == XML_REGEXP_ANYCHAR)) {
  ret = 1;
    } else if ((range1->type == XML_REGEXP_EPSILON) ||
               (range2->type == XML_REGEXP_EPSILON)) {
  return(0);
    } else if (range1->type == range2->type) {
        if (range1->type != XML_REGEXP_CHARVAL)
            ret = 1;
        else if ((range1->end < range2->start) ||
           (range2->end < range1->start))
      ret = 0;
  else
      ret = 1;
    } else if (range1->type == XML_REGEXP_CHARVAL) {
        int codepoint;
  int neg = 0;

  /*
   * just check all codepoints in the range for acceptance,
   * this is usually way cheaper since done only once at
   * compilation than testing over and over at runtime or
   * pushing too many states when evaluating.
   */
  if (((range1->neg == 0) && (range2->neg != 0)) ||
      ((range1->neg != 0) && (range2->neg == 0)))
      neg = 1;

  for (codepoint = range1->start;codepoint <= range1->end ;codepoint++) {
      ret = xmlRegCheckCharacterRange(range2->type, codepoint,
              0, range2->start, range2->end,
              range2->blockName);
      if (ret < 0)
          return(-1);
      if (((neg == 1) && (ret == 0)) ||
          ((neg == 0) && (ret == 1)))
    return(1);
  }
  return(0);
    } else if ((range1->type == XML_REGEXP_BLOCK_NAME) ||
               (range2->type == XML_REGEXP_BLOCK_NAME)) {
  if (range1->type == range2->type) {
      ret = xmlStrEqual(range1->blockName, range2->blockName);
  } else {
      /*
       * comparing a block range with anything else is way
       * too costly, and maintaining the table is like too much
       * memory too, so let's force the automata to save state
       * here.
       */
      return(1);
  }
    } else if ((range1->type < XML_REGEXP_LETTER) ||
               (range2->type < XML_REGEXP_LETTER)) {
  if ((range1->type == XML_REGEXP_ANYSPACE) &&
      (range2->type == XML_REGEXP_NOTSPACE))
      ret = 0;
  else if ((range1->type == XML_REGEXP_INITNAME) &&
           (range2->type == XML_REGEXP_NOTINITNAME))
      ret = 0;
  else if ((range1->type == XML_REGEXP_NAMECHAR) &&
           (range2->type == XML_REGEXP_NOTNAMECHAR))
      ret = 0;
  else if ((range1->type == XML_REGEXP_DECIMAL) &&
           (range2->type == XML_REGEXP_NOTDECIMAL))
      ret = 0;
  else if ((range1->type == XML_REGEXP_REALCHAR) &&
           (range2->type == XML_REGEXP_NOTREALCHAR))
      ret = 0;
  else {
      /* same thing to limit complexity */
      return(1);
  }
    } else {
        ret = 0;
        /* range1->type < range2->type here */
        switch (range1->type) {
      case XML_REGEXP_LETTER:
           /* all disjoint except in the subgroups */
           if ((range2->type == XML_REGEXP_LETTER_UPPERCASE) ||
         (range2->type == XML_REGEXP_LETTER_LOWERCASE) ||
         (range2->type == XML_REGEXP_LETTER_TITLECASE) ||
         (range2->type == XML_REGEXP_LETTER_MODIFIER) ||
         (range2->type == XML_REGEXP_LETTER_OTHERS))
         ret = 1;
     break;
      case XML_REGEXP_MARK:
           if ((range2->type == XML_REGEXP_MARK_NONSPACING) ||
         (range2->type == XML_REGEXP_MARK_SPACECOMBINING) ||
         (range2->type == XML_REGEXP_MARK_ENCLOSING))
         ret = 1;
     break;
      case XML_REGEXP_NUMBER:
           if ((range2->type == XML_REGEXP_NUMBER_DECIMAL) ||
         (range2->type == XML_REGEXP_NUMBER_LETTER) ||
         (range2->type == XML_REGEXP_NUMBER_OTHERS))
         ret = 1;
     break;
      case XML_REGEXP_PUNCT:
           if ((range2->type == XML_REGEXP_PUNCT_CONNECTOR) ||
         (range2->type == XML_REGEXP_PUNCT_DASH) ||
         (range2->type == XML_REGEXP_PUNCT_OPEN) ||
         (range2->type == XML_REGEXP_PUNCT_CLOSE) ||
         (range2->type == XML_REGEXP_PUNCT_INITQUOTE) ||
         (range2->type == XML_REGEXP_PUNCT_FINQUOTE) ||
         (range2->type == XML_REGEXP_PUNCT_OTHERS))
         ret = 1;
     break;
      case XML_REGEXP_SEPAR:
           if ((range2->type == XML_REGEXP_SEPAR_SPACE) ||
         (range2->type == XML_REGEXP_SEPAR_LINE) ||
         (range2->type == XML_REGEXP_SEPAR_PARA))
         ret = 1;
     break;
      case XML_REGEXP_SYMBOL:
           if ((range2->type == XML_REGEXP_SYMBOL_MATH) ||
         (range2->type == XML_REGEXP_SYMBOL_CURRENCY) ||
         (range2->type == XML_REGEXP_SYMBOL_MODIFIER) ||
         (range2->type == XML_REGEXP_SYMBOL_OTHERS))
         ret = 1;
     break;
      case XML_REGEXP_OTHER:
           if ((range2->type == XML_REGEXP_OTHER_CONTROL) ||
         (range2->type == XML_REGEXP_OTHER_FORMAT) ||
         (range2->type == XML_REGEXP_OTHER_PRIVATE))
         ret = 1;
     break;
            default:
           if ((range2->type >= XML_REGEXP_LETTER) &&
         (range2->type < XML_REGEXP_BLOCK_NAME))
         ret = 0;
     else {
         /* safety net ! */
         return(1);
     }
  }
    }
    if (((range1->neg == 0) && (range2->neg != 0)) ||
        ((range1->neg != 0) && (range2->neg == 0)))
  ret = !ret;
    return(ret);
}

/**
 * xmlFACompareAtomTypes:
 * @type1:  an atom type
 * @type2:  an atom type
 *
 * Compares two atoms type to check whether they intersect in some ways,
 * this is used by xmlFACompareAtoms only
 *
 * Returns 1 if they may intersect and 0 otherwise
 */
static int
xmlFACompareAtomTypes(xmlRegAtomType type1, xmlRegAtomType type2) {
    if ((type1 == XML_REGEXP_EPSILON) ||
        (type1 == XML_REGEXP_CHARVAL) ||
  (type1 == XML_REGEXP_RANGES) ||
  (type1 == XML_REGEXP_SUBREG) ||
  (type1 == XML_REGEXP_STRING) ||
  (type1 == XML_REGEXP_ANYCHAR))
  return(1);
    if ((type2 == XML_REGEXP_EPSILON) ||
        (type2 == XML_REGEXP_CHARVAL) ||
  (type2 == XML_REGEXP_RANGES) ||
  (type2 == XML_REGEXP_SUBREG) ||
  (type2 == XML_REGEXP_STRING) ||
  (type2 == XML_REGEXP_ANYCHAR))
  return(1);

    if (type1 == type2) return(1);

    /* simplify subsequent compares by making sure type1 < type2 */
    if (type1 > type2) {
        xmlRegAtomType tmp = type1;
  type1 = type2;
  type2 = tmp;
    }
    switch (type1) {
        case XML_REGEXP_ANYSPACE: /* \s */
      /* can't be a letter, number, mark, punctuation, symbol */
      if ((type2 == XML_REGEXP_NOTSPACE) ||
    ((type2 >= XML_REGEXP_LETTER) &&
     (type2 <= XML_REGEXP_LETTER_OTHERS)) ||
          ((type2 >= XML_REGEXP_NUMBER) &&
     (type2 <= XML_REGEXP_NUMBER_OTHERS)) ||
          ((type2 >= XML_REGEXP_MARK) &&
     (type2 <= XML_REGEXP_MARK_ENCLOSING)) ||
          ((type2 >= XML_REGEXP_PUNCT) &&
     (type2 <= XML_REGEXP_PUNCT_OTHERS)) ||
          ((type2 >= XML_REGEXP_SYMBOL) &&
     (type2 <= XML_REGEXP_SYMBOL_OTHERS))
          ) return(0);
      break;
        case XML_REGEXP_NOTSPACE: /* \S */
      break;
        case XML_REGEXP_INITNAME: /* \l */
      /* can't be a number, mark, separator, punctuation, symbol or other */
      if ((type2 == XML_REGEXP_NOTINITNAME) ||
          ((type2 >= XML_REGEXP_NUMBER) &&
     (type2 <= XML_REGEXP_NUMBER_OTHERS)) ||
          ((type2 >= XML_REGEXP_MARK) &&
     (type2 <= XML_REGEXP_MARK_ENCLOSING)) ||
          ((type2 >= XML_REGEXP_SEPAR) &&
     (type2 <= XML_REGEXP_SEPAR_PARA)) ||
          ((type2 >= XML_REGEXP_PUNCT) &&
     (type2 <= XML_REGEXP_PUNCT_OTHERS)) ||
          ((type2 >= XML_REGEXP_SYMBOL) &&
     (type2 <= XML_REGEXP_SYMBOL_OTHERS)) ||
          ((type2 >= XML_REGEXP_OTHER) &&
     (type2 <= XML_REGEXP_OTHER_NA))
    ) return(0);
      break;
        case XML_REGEXP_NOTINITNAME: /* \L */
      break;
        case XML_REGEXP_NAMECHAR: /* \c */
      /* can't be a mark, separator, punctuation, symbol or other */
      if ((type2 == XML_REGEXP_NOTNAMECHAR) ||
          ((type2 >= XML_REGEXP_MARK) &&
     (type2 <= XML_REGEXP_MARK_ENCLOSING)) ||
          ((type2 >= XML_REGEXP_PUNCT) &&
     (type2 <= XML_REGEXP_PUNCT_OTHERS)) ||
          ((type2 >= XML_REGEXP_SEPAR) &&
     (type2 <= XML_REGEXP_SEPAR_PARA)) ||
          ((type2 >= XML_REGEXP_SYMBOL) &&
     (type2 <= XML_REGEXP_SYMBOL_OTHERS)) ||
          ((type2 >= XML_REGEXP_OTHER) &&
     (type2 <= XML_REGEXP_OTHER_NA))
    ) return(0);
      break;
        case XML_REGEXP_NOTNAMECHAR: /* \C */
      break;
        case XML_REGEXP_DECIMAL: /* \d */
      /* can't be a letter, mark, separator, punctuation, symbol or other */
      if ((type2 == XML_REGEXP_NOTDECIMAL) ||
          (type2 == XML_REGEXP_REALCHAR) ||
    ((type2 >= XML_REGEXP_LETTER) &&
     (type2 <= XML_REGEXP_LETTER_OTHERS)) ||
          ((type2 >= XML_REGEXP_MARK) &&
     (type2 <= XML_REGEXP_MARK_ENCLOSING)) ||
          ((type2 >= XML_REGEXP_PUNCT) &&
     (type2 <= XML_REGEXP_PUNCT_OTHERS)) ||
          ((type2 >= XML_REGEXP_SEPAR) &&
     (type2 <= XML_REGEXP_SEPAR_PARA)) ||
          ((type2 >= XML_REGEXP_SYMBOL) &&
     (type2 <= XML_REGEXP_SYMBOL_OTHERS)) ||
          ((type2 >= XML_REGEXP_OTHER) &&
     (type2 <= XML_REGEXP_OTHER_NA))
    )return(0);
      break;
        case XML_REGEXP_NOTDECIMAL: /* \D */
      break;
        case XML_REGEXP_REALCHAR: /* \w */
      /* can't be a mark, separator, punctuation, symbol or other */
      if ((type2 == XML_REGEXP_NOTDECIMAL) ||
          ((type2 >= XML_REGEXP_MARK) &&
     (type2 <= XML_REGEXP_MARK_ENCLOSING)) ||
          ((type2 >= XML_REGEXP_PUNCT) &&
     (type2 <= XML_REGEXP_PUNCT_OTHERS)) ||
          ((type2 >= XML_REGEXP_SEPAR) &&
     (type2 <= XML_REGEXP_SEPAR_PARA)) ||
          ((type2 >= XML_REGEXP_SYMBOL) &&
     (type2 <= XML_REGEXP_SYMBOL_OTHERS)) ||
          ((type2 >= XML_REGEXP_OTHER) &&
     (type2 <= XML_REGEXP_OTHER_NA))
    )return(0);
      break;
        case XML_REGEXP_NOTREALCHAR: /* \W */
      break;
  /*
   * at that point we know both type 1 and type2 are from
   * character categories are ordered and are different,
   * it becomes simple because this is a partition
   */
        case XML_REGEXP_LETTER:
      if (type2 <= XML_REGEXP_LETTER_OTHERS)
          return(1);
      return(0);
        case XML_REGEXP_LETTER_UPPERCASE:
        case XML_REGEXP_LETTER_LOWERCASE:
        case XML_REGEXP_LETTER_TITLECASE:
        case XML_REGEXP_LETTER_MODIFIER:
        case XML_REGEXP_LETTER_OTHERS:
      return(0);
        case XML_REGEXP_MARK:
      if (type2 <= XML_REGEXP_MARK_ENCLOSING)
          return(1);
      return(0);
        case XML_REGEXP_MARK_NONSPACING:
        case XML_REGEXP_MARK_SPACECOMBINING:
        case XML_REGEXP_MARK_ENCLOSING:
      return(0);
        case XML_REGEXP_NUMBER:
      if (type2 <= XML_REGEXP_NUMBER_OTHERS)
          return(1);
      return(0);
        case XML_REGEXP_NUMBER_DECIMAL:
        case XML_REGEXP_NUMBER_LETTER:
        case XML_REGEXP_NUMBER_OTHERS:
      return(0);
        case XML_REGEXP_PUNCT:
      if (type2 <= XML_REGEXP_PUNCT_OTHERS)
          return(1);
      return(0);
        case XML_REGEXP_PUNCT_CONNECTOR:
        case XML_REGEXP_PUNCT_DASH:
        case XML_REGEXP_PUNCT_OPEN:
        case XML_REGEXP_PUNCT_CLOSE:
        case XML_REGEXP_PUNCT_INITQUOTE:
        case XML_REGEXP_PUNCT_FINQUOTE:
        case XML_REGEXP_PUNCT_OTHERS:
      return(0);
        case XML_REGEXP_SEPAR:
      if (type2 <= XML_REGEXP_SEPAR_PARA)
          return(1);
      return(0);
        case XML_REGEXP_SEPAR_SPACE:
        case XML_REGEXP_SEPAR_LINE:
        case XML_REGEXP_SEPAR_PARA:
      return(0);
        case XML_REGEXP_SYMBOL:
      if (type2 <= XML_REGEXP_SYMBOL_OTHERS)
          return(1);
      return(0);
        case XML_REGEXP_SYMBOL_MATH:
        case XML_REGEXP_SYMBOL_CURRENCY:
        case XML_REGEXP_SYMBOL_MODIFIER:
        case XML_REGEXP_SYMBOL_OTHERS:
      return(0);
        case XML_REGEXP_OTHER:
      if (type2 <= XML_REGEXP_OTHER_NA)
          return(1);
      return(0);
        case XML_REGEXP_OTHER_CONTROL:
        case XML_REGEXP_OTHER_FORMAT:
        case XML_REGEXP_OTHER_PRIVATE:
        case XML_REGEXP_OTHER_NA:
      return(0);
  default:
      break;
    }
    return(1);
}

/**
 * xmlFAEqualAtoms:
 * @atom1:  an atom
 * @atom2:  an atom
 * @deep: if not set only compare string pointers
 *
 * Compares two atoms to check whether they are the same exactly
 * this is used to remove equivalent transitions
 *
 * Returns 1 if same and 0 otherwise
 */
static int
xmlFAEqualAtoms(xmlRegAtomPtr atom1, xmlRegAtomPtr atom2, int deep) {
    int ret = 0;

    if (atom1 == atom2)
  return(1);
    if ((atom1 == NULL) || (atom2 == NULL))
  return(0);

    if (atom1->type != atom2->type)
        return(0);
    switch (atom1->type) {
        case XML_REGEXP_EPSILON:
      ret = 0;
      break;
        case XML_REGEXP_STRING:
            if (!deep)
                ret = (atom1->valuep == atom2->valuep);
            else
                ret = xmlStrEqual((xmlChar *)atom1->valuep,
                                  (xmlChar *)atom2->valuep);
      break;
        case XML_REGEXP_CHARVAL:
      ret = (atom1->codepoint == atom2->codepoint);
      break;
  case XML_REGEXP_RANGES:
      /* too hard to do in the general case */
      ret = 0;
  default:
      break;
    }
    return(ret);
}

/**
 * xmlFACompareAtoms:
 * @atom1:  an atom
 * @atom2:  an atom
 * @deep: if not set only compare string pointers
 *
 * Compares two atoms to check whether they intersect in some ways,
 * this is used by xmlFAComputesDeterminism and xmlFARecurseDeterminism only
 *
 * Returns 1 if yes and 0 otherwise
 */
static int
xmlFACompareAtoms(xmlRegAtomPtr atom1, xmlRegAtomPtr atom2, int deep) {
    int ret = 1;

    if (atom1 == atom2)
  return(1);
    if ((atom1 == NULL) || (atom2 == NULL))
  return(0);

    if ((atom1->type == XML_REGEXP_ANYCHAR) ||
        (atom2->type == XML_REGEXP_ANYCHAR))
  return(1);

    if (atom1->type > atom2->type) {
  xmlRegAtomPtr tmp;
  tmp = atom1;
  atom1 = atom2;
  atom2 = tmp;
    }
    if (atom1->type != atom2->type) {
        ret = xmlFACompareAtomTypes(atom1->type, atom2->type);
  /* if they can't intersect at the type level break now */
  if (ret == 0)
      return(0);
    }
    switch (atom1->type) {
        case XML_REGEXP_STRING:
            if (!deep)
                ret = (atom1->valuep != atom2->valuep);
            else {
                xmlChar *val1 = (xmlChar *)atom1->valuep;
                xmlChar *val2 = (xmlChar *)atom2->valuep;
                int compound1 = (xmlStrchr(val1, '|') != NULL);
                int compound2 = (xmlStrchr(val2, '|') != NULL);

                /* Ignore negative match flag for ##other namespaces */
                if (compound1 != compound2)
                    return(0);

                ret = xmlRegStrEqualWildcard(val1, val2);
            }
      break;
        case XML_REGEXP_EPSILON:
      goto not_determinist;
        case XML_REGEXP_CHARVAL:
      if (atom2->type == XML_REGEXP_CHARVAL) {
    ret = (atom1->codepoint == atom2->codepoint);
      } else {
          ret = xmlRegCheckCharacter(atom2, atom1->codepoint);
    if (ret < 0)
        ret = 1;
      }
      break;
        case XML_REGEXP_RANGES:
      if (atom2->type == XML_REGEXP_RANGES) {
          int i, j, res;
    xmlRegRangePtr r1, r2;

    /*
     * need to check that none of the ranges eventually matches
     */
    for (i = 0;i < atom1->nbRanges;i++) {
        for (j = 0;j < atom2->nbRanges;j++) {
      r1 = atom1->ranges[i];
      r2 = atom2->ranges[j];
      res = xmlFACompareRanges(r1, r2);
      if (res == 1) {
          ret = 1;
          goto done;
      }
        }
    }
    ret = 0;
      }
      break;
  default:
      goto not_determinist;
    }
done:
    if (atom1->neg != atom2->neg) {
        ret = !ret;
    }
    if (ret == 0)
        return(0);
not_determinist:
    return(1);
}

/**
 * xmlFARecurseDeterminism:
 * @ctxt:  a regexp parser context
 *
 * Check whether the associated regexp is determinist,
 * should be called after xmlFAEliminateEpsilonTransitions()
 *
 */
static int
xmlFARecurseDeterminism(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr state,
                  int fromnr, int tonr, xmlRegAtomPtr atom) {
    int ret = 1;
    int res;
    int transnr, nbTrans;
    xmlRegTransPtr t1;
    int deep = 1;

    if (state == NULL)
  return(ret);
    if (state->markd == XML_REGEXP_MARK_VISITED)
  return(ret);

    if (ctxt->flags & AM_AUTOMATA_RNG)
        deep = 0;

    /*
     * don't recurse on transitions potentially added in the course of
     * the elimination.
     */
    nbTrans = state->nbTrans;
    for (transnr = 0;transnr < nbTrans;transnr++) {
  t1 = &(state->trans[transnr]);
  /*
   * check transitions conflicting with the one looked at
   */
        if ((t1->to < 0) || (t1->to == fromnr))
            continue;
  if (t1->atom == NULL) {
      state->markd = XML_REGEXP_MARK_VISITED;
      res = xmlFARecurseDeterminism(ctxt, ctxt->states[t1->to],
                              fromnr, tonr, atom);
      if (res == 0) {
          ret = 0;
    /* t1->nd = 1; */
      }
      continue;
  }
  if (xmlFACompareAtoms(t1->atom, atom, deep)) {
            /* Treat equal transitions as deterministic. */
            if ((t1->to != tonr) ||
                (!xmlFAEqualAtoms(t1->atom, atom, deep)))
                ret = 0;
      /* mark the transition as non-deterministic */
      t1->nd = 1;
  }
    }
    return(ret);
}

/**
 * xmlFAFinishRecurseDeterminism:
 * @ctxt:  a regexp parser context
 *
 * Reset flags after checking determinism.
 */
static void
xmlFAFinishRecurseDeterminism(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr state) {
    int transnr, nbTrans;

    if (state == NULL)
  return;
    if (state->markd != XML_REGEXP_MARK_VISITED)
  return;
    state->markd = 0;

    nbTrans = state->nbTrans;
    for (transnr = 0; transnr < nbTrans; transnr++) {
  xmlRegTransPtr t1 = &state->trans[transnr];
  if ((t1->atom == NULL) && (t1->to >= 0))
      xmlFAFinishRecurseDeterminism(ctxt, ctxt->states[t1->to]);
    }
}

/**
 * xmlFAComputesDeterminism:
 * @ctxt:  a regexp parser context
 *
 * Check whether the associated regexp is determinist,
 * should be called after xmlFAEliminateEpsilonTransitions()
 *
 */
static int
xmlFAComputesDeterminism(xmlRegParserCtxtPtr ctxt) {
    int statenr, transnr;
    xmlRegStatePtr state;
    xmlRegTransPtr t1, t2, last;
    int i;
    int ret = 1;
    int deep = 1;

#ifdef DEBUG_REGEXP_GRAPH
    printf("xmlFAComputesDeterminism\n");
    xmlRegPrintCtxt(stdout, ctxt);
#endif
    if (ctxt->determinist != -1)
  return(ctxt->determinist);

    if (ctxt->flags & AM_AUTOMATA_RNG)
        deep = 0;

    /*
     * First cleanup the automata removing cancelled transitions
     */
    for (statenr = 0;statenr < ctxt->nbStates;statenr++) {
  state = ctxt->states[statenr];
  if (state == NULL)
      continue;
  if (state->nbTrans < 2)
      continue;
  for (transnr = 0;transnr < state->nbTrans;transnr++) {
      t1 = &(state->trans[transnr]);
      /*
       * Determinism checks in case of counted or all transitions
       * will have to be handled separately
       */
      if (t1->atom == NULL) {
    /* t1->nd = 1; */
    continue;
      }
      if (t1->to < 0) /* eliminated */
    continue;
      for (i = 0;i < transnr;i++) {
    t2 = &(state->trans[i]);
    if (t2->to < 0) /* eliminated */
        continue;
    if (t2->atom != NULL) {
        if (t1->to == t2->to) {
                        /*
                         * Here we use deep because we want to keep the
                         * transitions which indicate a conflict
                         */
      if (xmlFAEqualAtoms(t1->atom, t2->atom, deep) &&
                            (t1->counter == t2->counter) &&
                            (t1->count == t2->count))
          t2->to = -1; /* eliminated */
        }
    }
      }
  }
    }

    /*
     * Check for all states that there aren't 2 transitions
     * with the same atom and a different target.
     */
    for (statenr = 0;statenr < ctxt->nbStates;statenr++) {
  state = ctxt->states[statenr];
  if (state == NULL)
      continue;
  if (state->nbTrans < 2)
      continue;
  last = NULL;
  for (transnr = 0;transnr < state->nbTrans;transnr++) {
      t1 = &(state->trans[transnr]);
      /*
       * Determinism checks in case of counted or all transitions
       * will have to be handled separately
       */
      if (t1->atom == NULL) {
    continue;
      }
      if (t1->to < 0) /* eliminated */
    continue;
      for (i = 0;i < transnr;i++) {
    t2 = &(state->trans[i]);
    if (t2->to < 0) /* eliminated */
        continue;
    if (t2->atom != NULL) {
                    /*
                     * But here we don't use deep because we want to
                     * find transitions which indicate a conflict
                     */
        if (xmlFACompareAtoms(t1->atom, t2->atom, 1)) {
                        /*
                         * Treat equal counter transitions that couldn't be
                         * eliminated as deterministic.
                         */
                        if ((t1->to != t2->to) ||
                            (t1->counter == t2->counter) ||
                            (!xmlFAEqualAtoms(t1->atom, t2->atom, deep)))
                            ret = 0;
      /* mark the transitions as non-deterministic ones */
      t1->nd = 1;
      t2->nd = 1;
      last = t1;
        }
    } else {
                    int res;

        /*
         * do the closure in case of remaining specific
         * epsilon transitions like choices or all
         */
        res = xmlFARecurseDeterminism(ctxt, ctxt->states[t2->to],
              statenr, t1->to, t1->atom);
                    xmlFAFinishRecurseDeterminism(ctxt, ctxt->states[t2->to]);
        /* don't shortcut the computation so all non deterministic
           transition get marked down
        if (ret == 0)
      return(0);
         */
        if (res == 0) {
      t1->nd = 1;
      /* t2->nd = 1; */
      last = t1;
                        ret = 0;
        }
    }
      }
      /* don't shortcut the computation so all non deterministic
         transition get marked down
      if (ret == 0)
    break; */
  }

  /*
   * mark specifically the last non-deterministic transition
   * from a state since there is no need to set-up rollback
   * from it
   */
  if (last != NULL) {
      last->nd = 2;
  }

  /* don't shortcut the computation so all non deterministic
     transition get marked down
  if (ret == 0)
      break; */
    }

    ctxt->determinist = ret;
    return(ret);
}

/************************************************************************
 *                  *
 *  Routines to check input against transition atoms    *
 *                  *
 ************************************************************************/

static int
xmlRegCheckCharacterRange(xmlRegAtomType type, int codepoint, int neg,
                    int start, int end, const xmlChar *blockName) {
    int ret = 0;

    switch (type) {
        case XML_REGEXP_STRING:
        case XML_REGEXP_SUBREG:
        case XML_REGEXP_RANGES:
        case XML_REGEXP_EPSILON:
      return(-1);
        case XML_REGEXP_ANYCHAR:
      ret = ((codepoint != '\n') && (codepoint != '\r'));
      break;
        case XML_REGEXP_CHARVAL:
      ret = ((codepoint >= start) && (codepoint <= end));
      break;
        case XML_REGEXP_NOTSPACE:
      neg = !neg;
            /* Falls through. */
        case XML_REGEXP_ANYSPACE:
      ret = ((codepoint == '\n') || (codepoint == '\r') ||
       (codepoint == '\t') || (codepoint == ' '));
      break;
        case XML_REGEXP_NOTINITNAME:
      neg = !neg;
            /* Falls through. */
        case XML_REGEXP_INITNAME:
      ret = (IS_LETTER(codepoint) ||
       (codepoint == '_') || (codepoint == ':'));
      break;
        case XML_REGEXP_NOTNAMECHAR:
      neg = !neg;
            /* Falls through. */
        case XML_REGEXP_NAMECHAR:
      ret = (IS_LETTER(codepoint) || IS_DIGIT(codepoint) ||
       (codepoint == '.') || (codepoint == '-') ||
       (codepoint == '_') || (codepoint == ':') ||
       IS_COMBINING(codepoint) || IS_EXTENDER(codepoint));
      break;
        case XML_REGEXP_NOTDECIMAL:
      neg = !neg;
            /* Falls through. */
        case XML_REGEXP_DECIMAL:
      ret = xmlUCSIsCatNd(codepoint);
      break;
        case XML_REGEXP_REALCHAR:
      neg = !neg;
            /* Falls through. */
        case XML_REGEXP_NOTREALCHAR:
      ret = xmlUCSIsCatP(codepoint);
      if (ret == 0)
    ret = xmlUCSIsCatZ(codepoint);
      if (ret == 0)
    ret = xmlUCSIsCatC(codepoint);
      break;
        case XML_REGEXP_LETTER:
      ret = xmlUCSIsCatL(codepoint);
      break;
        case XML_REGEXP_LETTER_UPPERCASE:
      ret = xmlUCSIsCatLu(codepoint);
      break;
        case XML_REGEXP_LETTER_LOWERCASE:
      ret = xmlUCSIsCatLl(codepoint);
      break;
        case XML_REGEXP_LETTER_TITLECASE:
      ret = xmlUCSIsCatLt(codepoint);
      break;
        case XML_REGEXP_LETTER_MODIFIER:
      ret = xmlUCSIsCatLm(codepoint);
      break;
        case XML_REGEXP_LETTER_OTHERS:
      ret = xmlUCSIsCatLo(codepoint);
      break;
        case XML_REGEXP_MARK:
      ret = xmlUCSIsCatM(codepoint);
      break;
        case XML_REGEXP_MARK_NONSPACING:
      ret = xmlUCSIsCatMn(codepoint);
      break;
        case XML_REGEXP_MARK_SPACECOMBINING:
      ret = xmlUCSIsCatMc(codepoint);
      break;
        case XML_REGEXP_MARK_ENCLOSING:
      ret = xmlUCSIsCatMe(codepoint);
      break;
        case XML_REGEXP_NUMBER:
      ret = xmlUCSIsCatN(codepoint);
      break;
        case XML_REGEXP_NUMBER_DECIMAL:
      ret = xmlUCSIsCatNd(codepoint);
      break;
        case XML_REGEXP_NUMBER_LETTER:
      ret = xmlUCSIsCatNl(codepoint);
      break;
        case XML_REGEXP_NUMBER_OTHERS:
      ret = xmlUCSIsCatNo(codepoint);
      break;
        case XML_REGEXP_PUNCT:
      ret = xmlUCSIsCatP(codepoint);
      break;
        case XML_REGEXP_PUNCT_CONNECTOR:
      ret = xmlUCSIsCatPc(codepoint);
      break;
        case XML_REGEXP_PUNCT_DASH:
      ret = xmlUCSIsCatPd(codepoint);
      break;
        case XML_REGEXP_PUNCT_OPEN:
      ret = xmlUCSIsCatPs(codepoint);
      break;
        case XML_REGEXP_PUNCT_CLOSE:
      ret = xmlUCSIsCatPe(codepoint);
      break;
        case XML_REGEXP_PUNCT_INITQUOTE:
      ret = xmlUCSIsCatPi(codepoint);
      break;
        case XML_REGEXP_PUNCT_FINQUOTE:
      ret = xmlUCSIsCatPf(codepoint);
      break;
        case XML_REGEXP_PUNCT_OTHERS:
      ret = xmlUCSIsCatPo(codepoint);
      break;
        case XML_REGEXP_SEPAR:
      ret = xmlUCSIsCatZ(codepoint);
      break;
        case XML_REGEXP_SEPAR_SPACE:
      ret = xmlUCSIsCatZs(codepoint);
      break;
        case XML_REGEXP_SEPAR_LINE:
      ret = xmlUCSIsCatZl(codepoint);
      break;
        case XML_REGEXP_SEPAR_PARA:
      ret = xmlUCSIsCatZp(codepoint);
      break;
        case XML_REGEXP_SYMBOL:
      ret = xmlUCSIsCatS(codepoint);
      break;
        case XML_REGEXP_SYMBOL_MATH:
      ret = xmlUCSIsCatSm(codepoint);
      break;
        case XML_REGEXP_SYMBOL_CURRENCY:
      ret = xmlUCSIsCatSc(codepoint);
      break;
        case XML_REGEXP_SYMBOL_MODIFIER:
      ret = xmlUCSIsCatSk(codepoint);
      break;
        case XML_REGEXP_SYMBOL_OTHERS:
      ret = xmlUCSIsCatSo(codepoint);
      break;
        case XML_REGEXP_OTHER:
      ret = xmlUCSIsCatC(codepoint);
      break;
        case XML_REGEXP_OTHER_CONTROL:
      ret = xmlUCSIsCatCc(codepoint);
      break;
        case XML_REGEXP_OTHER_FORMAT:
      ret = xmlUCSIsCatCf(codepoint);
      break;
        case XML_REGEXP_OTHER_PRIVATE:
      ret = xmlUCSIsCatCo(codepoint);
      break;
        case XML_REGEXP_OTHER_NA:
      /* ret = xmlUCSIsCatCn(codepoint); */
      /* Seems it doesn't exist anymore in recent Unicode releases */
      ret = 0;
      break;
        case XML_REGEXP_BLOCK_NAME:
      ret = xmlUCSIsBlock(codepoint, (const char *) blockName);
      break;
    }
    if (neg)
  return(!ret);
    return(ret);
}

static int
xmlRegCheckCharacter(xmlRegAtomPtr atom, int codepoint) {
    int i, ret = 0;
    xmlRegRangePtr range;

    if ((atom == NULL) || (!IS_CHAR(codepoint)))
  return(-1);

    switch (atom->type) {
        case XML_REGEXP_SUBREG:
        case XML_REGEXP_EPSILON:
      return(-1);
        case XML_REGEXP_CHARVAL:
            return(codepoint == atom->codepoint);
        case XML_REGEXP_RANGES: {
      int accept = 0;

      for (i = 0;i < atom->nbRanges;i++) {
    range = atom->ranges[i];
    if (range->neg == 2) {
        ret = xmlRegCheckCharacterRange(range->type, codepoint,
            0, range->start, range->end,
            range->blockName);
        if (ret != 0)
      return(0); /* excluded char */
    } else if (range->neg) {
        ret = xmlRegCheckCharacterRange(range->type, codepoint,
            0, range->start, range->end,
            range->blockName);
        if (ret == 0)
            accept = 1;
        else
            return(0);
    } else {
        ret = xmlRegCheckCharacterRange(range->type, codepoint,
            0, range->start, range->end,
            range->blockName);
        if (ret != 0)
      accept = 1; /* might still be excluded */
    }
      }
      return(accept);
  }
        case XML_REGEXP_STRING:
      printf("TODO: XML_REGEXP_STRING\n");
      return(-1);
        case XML_REGEXP_ANYCHAR:
        case XML_REGEXP_ANYSPACE:
        case XML_REGEXP_NOTSPACE:
        case XML_REGEXP_INITNAME:
        case XML_REGEXP_NOTINITNAME:
        case XML_REGEXP_NAMECHAR:
        case XML_REGEXP_NOTNAMECHAR:
        case XML_REGEXP_DECIMAL:
        case XML_REGEXP_NOTDECIMAL:
        case XML_REGEXP_REALCHAR:
        case XML_REGEXP_NOTREALCHAR:
        case XML_REGEXP_LETTER:
        case XML_REGEXP_LETTER_UPPERCASE:
        case XML_REGEXP_LETTER_LOWERCASE:
        case XML_REGEXP_LETTER_TITLECASE:
        case XML_REGEXP_LETTER_MODIFIER:
        case XML_REGEXP_LETTER_OTHERS:
        case XML_REGEXP_MARK:
        case XML_REGEXP_MARK_NONSPACING:
        case XML_REGEXP_MARK_SPACECOMBINING:
        case XML_REGEXP_MARK_ENCLOSING:
        case XML_REGEXP_NUMBER:
        case XML_REGEXP_NUMBER_DECIMAL:
        case XML_REGEXP_NUMBER_LETTER:
        case XML_REGEXP_NUMBER_OTHERS:
        case XML_REGEXP_PUNCT:
        case XML_REGEXP_PUNCT_CONNECTOR:
        case XML_REGEXP_PUNCT_DASH:
        case XML_REGEXP_PUNCT_OPEN:
        case XML_REGEXP_PUNCT_CLOSE:
        case XML_REGEXP_PUNCT_INITQUOTE:
        case XML_REGEXP_PUNCT_FINQUOTE:
        case XML_REGEXP_PUNCT_OTHERS:
        case XML_REGEXP_SEPAR:
        case XML_REGEXP_SEPAR_SPACE:
        case XML_REGEXP_SEPAR_LINE:
        case XML_REGEXP_SEPAR_PARA:
        case XML_REGEXP_SYMBOL:
        case XML_REGEXP_SYMBOL_MATH:
        case XML_REGEXP_SYMBOL_CURRENCY:
        case XML_REGEXP_SYMBOL_MODIFIER:
        case XML_REGEXP_SYMBOL_OTHERS:
        case XML_REGEXP_OTHER:
        case XML_REGEXP_OTHER_CONTROL:
        case XML_REGEXP_OTHER_FORMAT:
        case XML_REGEXP_OTHER_PRIVATE:
        case XML_REGEXP_OTHER_NA:
  case XML_REGEXP_BLOCK_NAME:
      ret = xmlRegCheckCharacterRange(atom->type, codepoint, 0, 0, 0,
                                (const xmlChar *)atom->valuep);
      if (atom->neg)
    ret = !ret;
      break;
    }
    return(ret);
}

/************************************************************************
 *                  *
 *  Saving and restoring state of an execution context    *
 *                  *
 ************************************************************************/

#ifdef DEBUG_REGEXP_EXEC
static void
xmlFARegDebugExec(xmlRegExecCtxtPtr exec) {
    printf("state: %d:%d:idx %d", exec->state->no, exec->transno, exec->index);
    if (exec->inputStack != NULL) {
  int i;
  printf(": ");
  for (i = 0;(i < 3) && (i < exec->inputStackNr);i++)
      printf("%s ", (const char *)
             exec->inputStack[exec->inputStackNr - (i + 1)].value);
    } else {
  printf(": %s", &(exec->inputString[exec->index]));
    }
    printf("\n");
}
#endif

static void
xmlFARegExecSave(xmlRegExecCtxtPtr exec) {
#ifdef DEBUG_REGEXP_EXEC
    printf("saving ");
    exec->transno++;
    xmlFARegDebugExec(exec);
    exec->transno--;
#endif
#ifdef MAX_PUSH
    if (exec->nbPush > MAX_PUSH) {
        return;
    }
    exec->nbPush++;
#endif

    if (exec->maxRollbacks == 0) {
  exec->maxRollbacks = 4;
  exec->rollbacks = (xmlRegExecRollback *) xmlMalloc(exec->maxRollbacks *
                                 sizeof(xmlRegExecRollback));
  if (exec->rollbacks == NULL) {
      xmlRegexpErrMemory(NULL, "saving regexp");
      exec->maxRollbacks = 0;
      return;
  }
  memset(exec->rollbacks, 0,
         exec->maxRollbacks * sizeof(xmlRegExecRollback));
    } else if (exec->nbRollbacks >= exec->maxRollbacks) {
  xmlRegExecRollback *tmp;
  int len = exec->maxRollbacks;

  exec->maxRollbacks *= 2;
  tmp = (xmlRegExecRollback *) xmlRealloc(exec->rollbacks,
      exec->maxRollbacks * sizeof(xmlRegExecRollback));
  if (tmp == NULL) {
      xmlRegexpErrMemory(NULL, "saving regexp");
      exec->maxRollbacks /= 2;
      return;
  }
  exec->rollbacks = tmp;
  tmp = &exec->rollbacks[len];
  memset(tmp, 0, (exec->maxRollbacks - len) * sizeof(xmlRegExecRollback));
    }
    exec->rollbacks[exec->nbRollbacks].state = exec->state;
    exec->rollbacks[exec->nbRollbacks].index = exec->index;
    exec->rollbacks[exec->nbRollbacks].nextbranch = exec->transno + 1;
    if (exec->comp->nbCounters > 0) {
  if (exec->rollbacks[exec->nbRollbacks].counts == NULL) {
      exec->rollbacks[exec->nbRollbacks].counts = (int *)
    xmlMalloc(exec->comp->nbCounters * sizeof(int));
      if (exec->rollbacks[exec->nbRollbacks].counts == NULL) {
    xmlRegexpErrMemory(NULL, "saving regexp");
    exec->status = -5;
    return;
      }
  }
  memcpy(exec->rollbacks[exec->nbRollbacks].counts, exec->counts,
         exec->comp->nbCounters * sizeof(int));
    }
    exec->nbRollbacks++;
}

static void
xmlFARegExecRollBack(xmlRegExecCtxtPtr exec) {
    if (exec->nbRollbacks <= 0) {
  exec->status = -1;
#ifdef DEBUG_REGEXP_EXEC
  printf("rollback failed on empty stack\n");
#endif
  return;
    }
    exec->nbRollbacks--;
    exec->state = exec->rollbacks[exec->nbRollbacks].state;
    exec->index = exec->rollbacks[exec->nbRollbacks].index;
    exec->transno = exec->rollbacks[exec->nbRollbacks].nextbranch;
    if (exec->comp->nbCounters > 0) {
  if (exec->rollbacks[exec->nbRollbacks].counts == NULL) {
      fprintf(stderr, "exec save: allocation failed");
      exec->status = -6;
      return;
  }
  if (exec->counts) {
      memcpy(exec->counts, exec->rollbacks[exec->nbRollbacks].counts,
         exec->comp->nbCounters * sizeof(int));
  }
    }

#ifdef DEBUG_REGEXP_EXEC
    printf("restored ");
    xmlFARegDebugExec(exec);
#endif
}

/************************************************************************
 *                  *
 *  Verifier, running an input against a compiled regexp    *
 *                  *
 ************************************************************************/

static int
xmlFARegExec(xmlRegexpPtr comp, const xmlChar *content) {
    xmlRegExecCtxt execval;
    xmlRegExecCtxtPtr exec = &execval;
    int ret, codepoint = 0, len, deter;

    exec->inputString = content;
    exec->index = 0;
    exec->nbPush = 0;
    exec->determinist = 1;
    exec->maxRollbacks = 0;
    exec->nbRollbacks = 0;
    exec->rollbacks = NULL;
    exec->status = 0;
    exec->comp = comp;
    exec->state = comp->states[0];
    exec->transno = 0;
    exec->transcount = 0;
    exec->inputStack = NULL;
    exec->inputStackMax = 0;
    if (comp->nbCounters > 0) {
  exec->counts = (int *) xmlMalloc(comp->nbCounters * sizeof(int));
  if (exec->counts == NULL) {
      xmlRegexpErrMemory(NULL, "running regexp");
      return(-1);
  }
        memset(exec->counts, 0, comp->nbCounters * sizeof(int));
    } else
  exec->counts = NULL;
    while ((exec->status == 0) && (exec->state != NULL) &&
     ((exec->inputString[exec->index] != 0) ||
      ((exec->state != NULL) &&
       (exec->state->type != XML_REGEXP_FINAL_STATE)))) {
  xmlRegTransPtr trans;
  xmlRegAtomPtr atom;

  /*
   * If end of input on non-terminal state, rollback, however we may
   * still have epsilon like transition for counted transitions
   * on counters, in that case don't break too early.  Additionally,
   * if we are working on a range like "AB{0,2}", where B is not present,
   * we don't want to break.
   */
  len = 1;
  if ((exec->inputString[exec->index] == 0) && (exec->counts == NULL)) {
      /*
       * if there is a transition, we must check if
       *  atom allows minOccurs of 0
       */
      if (exec->transno < exec->state->nbTrans) {
          trans = &exec->state->trans[exec->transno];
    if (trans->to >=0) {
        atom = trans->atom;
        if (!((atom->min == 0) && (atom->max > 0)))
            goto rollback;
    }
      } else
          goto rollback;
  }

  exec->transcount = 0;
  for (;exec->transno < exec->state->nbTrans;exec->transno++) {
      trans = &exec->state->trans[exec->transno];
      if (trans->to < 0)
    continue;
      atom = trans->atom;
      ret = 0;
      deter = 1;
      if (trans->count >= 0) {
    int count;
    xmlRegCounterPtr counter;

    if (exec->counts == NULL) {
        exec->status = -1;
        goto error;
    }
    /*
     * A counted transition.
     */

    count = exec->counts[trans->count];
    counter = &exec->comp->counters[trans->count];
#ifdef DEBUG_REGEXP_EXEC
    printf("testing count %d: val %d, min %d, max %d\n",
           trans->count, count, counter->min,  counter->max);
#endif
    ret = ((count >= counter->min) && (count <= counter->max));
    if ((ret) && (counter->min != counter->max))
        deter = 0;
      } else if (atom == NULL) {
    fprintf(stderr, "epsilon transition left at runtime\n");
    exec->status = -2;
    break;
      } else if (exec->inputString[exec->index] != 0) {
                codepoint = CUR_SCHAR(&(exec->inputString[exec->index]), len);
    ret = xmlRegCheckCharacter(atom, codepoint);
    if ((ret == 1) && (atom->min >= 0) && (atom->max > 0)) {
        xmlRegStatePtr to = comp->states[trans->to];

        /*
         * this is a multiple input sequence
         * If there is a counter associated increment it now.
         * do not increment if the counter is already over the
         * maximum limit in which case get to next transition
         */
        if (trans->counter >= 0) {
      xmlRegCounterPtr counter;

      if ((exec->counts == NULL) ||
          (exec->comp == NULL) ||
          (exec->comp->counters == NULL)) {
          exec->status = -1;
          goto error;
      }
      counter = &exec->comp->counters[trans->counter];
      if (exec->counts[trans->counter] >= counter->max)
          continue; /* for loop on transitions */
                    }
                    /* Save before incrementing */
        if (exec->state->nbTrans > exec->transno + 1) {
      xmlFARegExecSave(exec);
        }
        if (trans->counter >= 0) {
#ifdef DEBUG_REGEXP_EXEC
      printf("Increasing count %d\n", trans->counter);
#endif
      exec->counts[trans->counter]++;
        }
        exec->transcount = 1;
        do {
      /*
       * Try to progress as much as possible on the input
       */
      if (exec->transcount == atom->max) {
          break;
      }
      exec->index += len;
      /*
       * End of input: stop here
       */
      if (exec->inputString[exec->index] == 0) {
          exec->index -= len;
          break;
      }
      if (exec->transcount >= atom->min) {
          int transno = exec->transno;
          xmlRegStatePtr state = exec->state;

          /*
           * The transition is acceptable save it
           */
          exec->transno = -1; /* trick */
          exec->state = to;
          xmlFARegExecSave(exec);
          exec->transno = transno;
          exec->state = state;
      }
      codepoint = CUR_SCHAR(&(exec->inputString[exec->index]),
                      len);
      ret = xmlRegCheckCharacter(atom, codepoint);
      exec->transcount++;
        } while (ret == 1);
        if (exec->transcount < atom->min)
      ret = 0;

        /*
         * If the last check failed but one transition was found
         * possible, rollback
         */
        if (ret < 0)
      ret = 0;
        if (ret == 0) {
      goto rollback;
        }
        if (trans->counter >= 0) {
      if (exec->counts == NULL) {
          exec->status = -1;
          goto error;
      }
#ifdef DEBUG_REGEXP_EXEC
      printf("Decreasing count %d\n", trans->counter);
#endif
      exec->counts[trans->counter]--;
        }
    } else if ((ret == 0) && (atom->min == 0) && (atom->max > 0)) {
        /*
         * we don't match on the codepoint, but minOccurs of 0
         * says that's ok.  Setting len to 0 inhibits stepping
         * over the codepoint.
         */
        exec->transcount = 1;
        len = 0;
        ret = 1;
    }
      } else if ((atom->min == 0) && (atom->max > 0)) {
          /* another spot to match when minOccurs is 0 */
    exec->transcount = 1;
    len = 0;
    ret = 1;
      }
      if (ret == 1) {
    if ((trans->nd == 1) ||
        ((trans->count >= 0) && (deter == 0) &&
         (exec->state->nbTrans > exec->transno + 1))) {
#ifdef DEBUG_REGEXP_EXEC
        if (trans->nd == 1)
            printf("Saving on nd transition atom %d for %c at %d\n",
             trans->atom->no, codepoint, exec->index);
        else
            printf("Saving on counted transition count %d for %c at %d\n",
             trans->count, codepoint, exec->index);
#endif
        xmlFARegExecSave(exec);
    }
    if (trans->counter >= 0) {
        xmlRegCounterPtr counter;

                    /* make sure we don't go over the counter maximum value */
        if ((exec->counts == NULL) ||
      (exec->comp == NULL) ||
      (exec->comp->counters == NULL)) {
      exec->status = -1;
      goto error;
        }
        counter = &exec->comp->counters[trans->counter];
        if (exec->counts[trans->counter] >= counter->max)
      continue; /* for loop on transitions */
#ifdef DEBUG_REGEXP_EXEC
        printf("Increasing count %d\n", trans->counter);
#endif
        exec->counts[trans->counter]++;
    }
    if ((trans->count >= 0) &&
        (trans->count < REGEXP_ALL_COUNTER)) {
        if (exec->counts == NULL) {
            exec->status = -1;
      goto error;
        }
#ifdef DEBUG_REGEXP_EXEC
        printf("resetting count %d on transition\n",
               trans->count);
#endif
        exec->counts[trans->count] = 0;
    }
#ifdef DEBUG_REGEXP_EXEC
    printf("entering state %d\n", trans->to);
#endif
    exec->state = comp->states[trans->to];
    exec->transno = 0;
    if (trans->atom != NULL) {
        exec->index += len;
    }
    goto progress;
      } else if (ret < 0) {
    exec->status = -4;
    break;
      }
  }
  if ((exec->transno != 0) || (exec->state->nbTrans == 0)) {
rollback:
      /*
       * Failed to find a way out
       */
      exec->determinist = 0;
#ifdef DEBUG_REGEXP_EXEC
      printf("rollback from state %d on %d:%c\n", exec->state->no,
             codepoint,codepoint);
#endif
      xmlFARegExecRollBack(exec);
  }
progress:
  continue;
    }
error:
    if (exec->rollbacks != NULL) {
  if (exec->counts != NULL) {
      int i;

      for (i = 0;i < exec->maxRollbacks;i++)
    if (exec->rollbacks[i].counts != NULL)
        xmlFree(exec->rollbacks[i].counts);
  }
  xmlFree(exec->rollbacks);
    }
    if (exec->state == NULL)
        return(-1);
    if (exec->counts != NULL)
  xmlFree(exec->counts);
    if (exec->status == 0)
  return(1);
    if (exec->status == -1) {
  if (exec->nbPush > MAX_PUSH)
      return(-1);
  return(0);
    }
    return(exec->status);
}

/************************************************************************
 *                  *
 *  Progressive interface to the verifier one atom at a time  *
 *                  *
 ************************************************************************/
#ifdef DEBUG_ERR
static void testerr(xmlRegExecCtxtPtr exec);
#endif

/**
 * xmlRegNewExecCtxt:
 * @comp: a precompiled regular expression
 * @callback: a callback function used for handling progresses in the
 *            automata matching phase
 * @data: the context data associated to the callback in this context
 *
 * Build a context used for progressive evaluation of a regexp.
 *
 * Returns the new context
 */
xmlRegExecCtxtPtr
xmlRegNewExecCtxt(xmlRegexpPtr comp, xmlRegExecCallbacks callback, void *data) {
    xmlRegExecCtxtPtr exec;

    if (comp == NULL)
  return(NULL);
    if ((comp->compact == NULL) && (comp->states == NULL))
        return(NULL);
    exec = (xmlRegExecCtxtPtr) xmlMalloc(sizeof(xmlRegExecCtxt));
    if (exec == NULL) {
  xmlRegexpErrMemory(NULL, "creating execution context");
  return(NULL);
    }
    memset(exec, 0, sizeof(xmlRegExecCtxt));
    exec->inputString = NULL;
    exec->index = 0;
    exec->determinist = 1;
    exec->maxRollbacks = 0;
    exec->nbRollbacks = 0;
    exec->rollbacks = NULL;
    exec->status = 0;
    exec->comp = comp;
    if (comp->compact == NULL)
  exec->state = comp->states[0];
    exec->transno = 0;
    exec->transcount = 0;
    exec->callback = callback;
    exec->data = data;
    if (comp->nbCounters > 0) {
        /*
   * For error handling, exec->counts is allocated twice the size
   * the second half is used to store the data in case of rollback
   */
  exec->counts = (int *) xmlMalloc(comp->nbCounters * sizeof(int)
                                   * 2);
  if (exec->counts == NULL) {
      xmlRegexpErrMemory(NULL, "creating execution context");
      xmlFree(exec);
      return(NULL);
  }
        memset(exec->counts, 0, comp->nbCounters * sizeof(int) * 2);
  exec->errCounts = &exec->counts[comp->nbCounters];
    } else {
  exec->counts = NULL;
  exec->errCounts = NULL;
    }
    exec->inputStackMax = 0;
    exec->inputStackNr = 0;
    exec->inputStack = NULL;
    exec->errStateNo = -1;
    exec->errString = NULL;
    exec->nbPush = 0;
    return(exec);
}

/**
 * xmlRegFreeExecCtxt:
 * @exec: a regular expression evaluation context
 *
 * Free the structures associated to a regular expression evaluation context.
 */
void
xmlRegFreeExecCtxt(xmlRegExecCtxtPtr exec) {
    if (exec == NULL)
  return;

    if (exec->rollbacks != NULL) {
  if (exec->counts != NULL) {
      int i;

      for (i = 0;i < exec->maxRollbacks;i++)
    if (exec->rollbacks[i].counts != NULL)
        xmlFree(exec->rollbacks[i].counts);
  }
  xmlFree(exec->rollbacks);
    }
    if (exec->counts != NULL)
  xmlFree(exec->counts);
    if (exec->inputStack != NULL) {
  int i;

  for (i = 0;i < exec->inputStackNr;i++) {
      if (exec->inputStack[i].value != NULL)
    xmlFree(exec->inputStack[i].value);
  }
  xmlFree(exec->inputStack);
    }
    if (exec->errString != NULL)
        xmlFree(exec->errString);
    xmlFree(exec);
}

static void
xmlFARegExecSaveInputString(xmlRegExecCtxtPtr exec, const xmlChar *value,
                      void *data) {
#ifdef DEBUG_PUSH
    printf("saving value: %d:%s\n", exec->inputStackNr, value);
#endif
    if (exec->inputStackMax == 0) {
  exec->inputStackMax = 4;
  exec->inputStack = (xmlRegInputTokenPtr)
      xmlMalloc(exec->inputStackMax * sizeof(xmlRegInputToken));
  if (exec->inputStack == NULL) {
      xmlRegexpErrMemory(NULL, "pushing input string");
      exec->inputStackMax = 0;
      return;
  }
    } else if (exec->inputStackNr + 1 >= exec->inputStackMax) {
  xmlRegInputTokenPtr tmp;

  exec->inputStackMax *= 2;
  tmp = (xmlRegInputTokenPtr) xmlRealloc(exec->inputStack,
      exec->inputStackMax * sizeof(xmlRegInputToken));
  if (tmp == NULL) {
      xmlRegexpErrMemory(NULL, "pushing input string");
      exec->inputStackMax /= 2;
      return;
  }
  exec->inputStack = tmp;
    }
    exec->inputStack[exec->inputStackNr].value = xmlStrdup(value);
    exec->inputStack[exec->inputStackNr].data = data;
    exec->inputStackNr++;
    exec->inputStack[exec->inputStackNr].value = NULL;
    exec->inputStack[exec->inputStackNr].data = NULL;
}

/**
 * xmlRegStrEqualWildcard:
 * @expStr:  the string to be evaluated
 * @valStr:  the validation string
 *
 * Checks if both strings are equal or have the same content. "*"
 * can be used as a wildcard in @valStr; "|" is used as a separator of
 * substrings in both @expStr and @valStr.
 *
 * Returns 1 if the comparison is satisfied and the number of substrings
 * is equal, 0 otherwise.
 */

static int
xmlRegStrEqualWildcard(const xmlChar *expStr, const xmlChar *valStr) {
    if (expStr == valStr) return(1);
    if (expStr == NULL) return(0);
    if (valStr == NULL) return(0);
    do {
  /*
  * Eval if we have a wildcard for the current item.
  */
        if (*expStr != *valStr) {
      /* if one of them starts with a wildcard make valStr be it */
      if (*valStr == '*') {
          const xmlChar *tmp;

    tmp = valStr;
    valStr = expStr;
    expStr = tmp;
      }
      if ((*valStr != 0) && (*expStr != 0) && (*expStr++ == '*')) {
    do {
        if (*valStr == XML_REG_STRING_SEPARATOR)
      break;
        valStr++;
    } while (*valStr != 0);
    continue;
      } else
    return(0);
  }
  expStr++;
  valStr++;
    } while (*valStr != 0);
    if (*expStr != 0)
  return (0);
    else
  return (1);
}

/**
 * xmlRegCompactPushString:
 * @exec: a regexp execution context
 * @comp:  the precompiled exec with a compact table
 * @value: a string token input
 * @data: data associated to the token to reuse in callbacks
 *
 * Push one input token in the execution context
 *
 * Returns: 1 if the regexp reached a final state, 0 if non-final, and
 *     a negative value in case of error.
 */
static int
xmlRegCompactPushString(xmlRegExecCtxtPtr exec,
                  xmlRegexpPtr comp,
                  const xmlChar *value,
                  void *data) {
    int state = exec->index;
    int i, target;

    if ((comp == NULL) || (comp->compact == NULL) || (comp->stringMap == NULL))
  return(-1);

    if (value == NULL) {
  /*
   * are we at a final state ?
   */
  if (comp->compact[state * (comp->nbstrings + 1)] ==
            XML_REGEXP_FINAL_STATE)
      return(1);
  return(0);
    }

#ifdef DEBUG_PUSH
    printf("value pushed: %s\n", value);
#endif

    /*
     * Examine all outside transitions from current state
     */
    for (i = 0;i < comp->nbstrings;i++) {
  target = comp->compact[state * (comp->nbstrings + 1) + i + 1];
  if ((target > 0) && (target <= comp->nbstates)) {
      target--; /* to avoid 0 */
      if (xmlRegStrEqualWildcard(comp->stringMap[i], value)) {
    exec->index = target;
    if ((exec->callback != NULL) && (comp->transdata != NULL)) {
        exec->callback(exec->data, value,
        comp->transdata[state * comp->nbstrings + i], data);
    }
#ifdef DEBUG_PUSH
    printf("entering state %d\n", target);
#endif
    if (comp->compact[target * (comp->nbstrings + 1)] ==
        XML_REGEXP_SINK_STATE)
        goto error;

    if (comp->compact[target * (comp->nbstrings + 1)] ==
        XML_REGEXP_FINAL_STATE)
        return(1);
    return(0);
      }
  }
    }
    /*
     * Failed to find an exit transition out from current state for the
     * current token
     */
#ifdef DEBUG_PUSH
    printf("failed to find a transition for %s on state %d\n", value, state);
#endif
error:
    if (exec->errString != NULL)
        xmlFree(exec->errString);
    exec->errString = xmlStrdup(value);
    exec->errStateNo = state;
    exec->status = -1;
#ifdef DEBUG_ERR
    testerr(exec);
#endif
    return(-1);
}

/**
 * xmlRegExecPushStringInternal:
 * @exec: a regexp execution context or NULL to indicate the end
 * @value: a string token input
 * @data: data associated to the token to reuse in callbacks
 * @compound: value was assembled from 2 strings
 *
 * Push one input token in the execution context
 *
 * Returns: 1 if the regexp reached a final state, 0 if non-final, and
 *     a negative value in case of error.
 */
static int
xmlRegExecPushStringInternal(xmlRegExecCtxtPtr exec, const xmlChar *value,
                       void *data, int compound) {
    xmlRegTransPtr trans;
    xmlRegAtomPtr atom;
    int ret;
    int final = 0;
    int progress = 1;

    if (exec == NULL)
  return(-1);
    if (exec->comp == NULL)
  return(-1);
    if (exec->status != 0)
  return(exec->status);

    if (exec->comp->compact != NULL)
  return(xmlRegCompactPushString(exec, exec->comp, value, data));

    if (value == NULL) {
        if (exec->state->type == XML_REGEXP_FINAL_STATE)
      return(1);
  final = 1;
    }

#ifdef DEBUG_PUSH
    printf("value pushed: %s\n", value);
#endif
    /*
     * If we have an active rollback stack push the new value there
     * and get back to where we were left
     */
    if ((value != NULL) && (exec->inputStackNr > 0)) {
  xmlFARegExecSaveInputString(exec, value, data);
  value = exec->inputStack[exec->index].value;
  data = exec->inputStack[exec->index].data;
#ifdef DEBUG_PUSH
  printf("value loaded: %s\n", value);
#endif
    }

    while ((exec->status == 0) &&
     ((value != NULL) ||
      ((final == 1) &&
       (exec->state->type != XML_REGEXP_FINAL_STATE)))) {

  /*
   * End of input on non-terminal state, rollback, however we may
   * still have epsilon like transition for counted transitions
   * on counters, in that case don't break too early.
   */
  if ((value == NULL) && (exec->counts == NULL))
      goto rollback;

  exec->transcount = 0;
  for (;exec->transno < exec->state->nbTrans;exec->transno++) {
      trans = &exec->state->trans[exec->transno];
      if (trans->to < 0)
    continue;
      atom = trans->atom;
      ret = 0;
      if (trans->count == REGEXP_ALL_LAX_COUNTER) {
    int i;
    int count;
    xmlRegTransPtr t;
    xmlRegCounterPtr counter;

    ret = 0;

#ifdef DEBUG_PUSH
    printf("testing all lax %d\n", trans->count);
#endif
    /*
     * Check all counted transitions from the current state
     */
    if ((value == NULL) && (final)) {
        ret = 1;
    } else if (value != NULL) {
        for (i = 0;i < exec->state->nbTrans;i++) {
      t = &exec->state->trans[i];
      if ((t->counter < 0) || (t == trans))
          continue;
      counter = &exec->comp->counters[t->counter];
      count = exec->counts[t->counter];
      if ((count < counter->max) &&
                (t->atom != NULL) &&
          (xmlStrEqual(value, t->atom->valuep))) {
          ret = 0;
          break;
      }
      if ((count >= counter->min) &&
          (count < counter->max) &&
          (t->atom != NULL) &&
          (xmlStrEqual(value, t->atom->valuep))) {
          ret = 1;
          break;
      }
        }
    }
      } else if (trans->count == REGEXP_ALL_COUNTER) {
    int i;
    int count;
    xmlRegTransPtr t;
    xmlRegCounterPtr counter;

    ret = 1;

#ifdef DEBUG_PUSH
    printf("testing all %d\n", trans->count);
#endif
    /*
     * Check all counted transitions from the current state
     */
    for (i = 0;i < exec->state->nbTrans;i++) {
                    t = &exec->state->trans[i];
        if ((t->counter < 0) || (t == trans))
      continue;
                    counter = &exec->comp->counters[t->counter];
        count = exec->counts[t->counter];
        if ((count < counter->min) || (count > counter->max)) {
      ret = 0;
      break;
        }
    }
      } else if (trans->count >= 0) {
    int count;
    xmlRegCounterPtr counter;

    /*
     * A counted transition.
     */

    count = exec->counts[trans->count];
    counter = &exec->comp->counters[trans->count];
#ifdef DEBUG_PUSH
    printf("testing count %d: val %d, min %d, max %d\n",
           trans->count, count, counter->min,  counter->max);
#endif
    ret = ((count >= counter->min) && (count <= counter->max));
      } else if (atom == NULL) {
    fprintf(stderr, "epsilon transition left at runtime\n");
    exec->status = -2;
    break;
      } else if (value != NULL) {
    ret = xmlRegStrEqualWildcard(atom->valuep, value);
    if (atom->neg) {
        ret = !ret;
        if (!compound)
            ret = 0;
    }
    if ((ret == 1) && (trans->counter >= 0)) {
        xmlRegCounterPtr counter;
        int count;

        count = exec->counts[trans->counter];
        counter = &exec->comp->counters[trans->counter];
        if (count >= counter->max)
      ret = 0;
    }

    if ((ret == 1) && (atom->min > 0) && (atom->max > 0)) {
        xmlRegStatePtr to = exec->comp->states[trans->to];

        /*
         * this is a multiple input sequence
         */
        if (exec->state->nbTrans > exec->transno + 1) {
      if (exec->inputStackNr <= 0) {
          xmlFARegExecSaveInputString(exec, value, data);
      }
      xmlFARegExecSave(exec);
        }
        exec->transcount = 1;
        do {
      /*
       * Try to progress as much as possible on the input
       */
      if (exec->transcount == atom->max) {
          break;
      }
      exec->index++;
      value = exec->inputStack[exec->index].value;
      data = exec->inputStack[exec->index].data;
#ifdef DEBUG_PUSH
      printf("value loaded: %s\n", value);
#endif

      /*
       * End of input: stop here
       */
      if (value == NULL) {
          exec->index --;
          break;
      }
      if (exec->transcount >= atom->min) {
          int transno = exec->transno;
          xmlRegStatePtr state = exec->state;

          /*
           * The transition is acceptable save it
           */
          exec->transno = -1; /* trick */
          exec->state = to;
          if (exec->inputStackNr <= 0) {
        xmlFARegExecSaveInputString(exec, value, data);
          }
          xmlFARegExecSave(exec);
          exec->transno = transno;
          exec->state = state;
      }
      ret = xmlStrEqual(value, atom->valuep);
      exec->transcount++;
        } while (ret == 1);
        if (exec->transcount < atom->min)
      ret = 0;

        /*
         * If the last check failed but one transition was found
         * possible, rollback
         */
        if (ret < 0)
      ret = 0;
        if (ret == 0) {
      goto rollback;
        }
    }
      }
      if (ret == 1) {
    if ((exec->callback != NULL) && (atom != NULL) &&
      (data != NULL)) {
        exec->callback(exec->data, atom->valuep,
                 atom->data, data);
    }
    if (exec->state->nbTrans > exec->transno + 1) {
        if (exec->inputStackNr <= 0) {
      xmlFARegExecSaveInputString(exec, value, data);
        }
        xmlFARegExecSave(exec);
    }
    if (trans->counter >= 0) {
#ifdef DEBUG_PUSH
        printf("Increasing count %d\n", trans->counter);
#endif
        exec->counts[trans->counter]++;
    }
    if ((trans->count >= 0) &&
        (trans->count < REGEXP_ALL_COUNTER)) {
#ifdef DEBUG_REGEXP_EXEC
        printf("resetting count %d on transition\n",
               trans->count);
#endif
        exec->counts[trans->count] = 0;
    }
#ifdef DEBUG_PUSH
    printf("entering state %d\n", trans->to);
#endif
                if ((exec->comp->states[trans->to] != NULL) &&
        (exec->comp->states[trans->to]->type ==
         XML_REGEXP_SINK_STATE)) {
        /*
         * entering a sink state, save the current state as error
         * state.
         */
        if (exec->errString != NULL)
      xmlFree(exec->errString);
        exec->errString = xmlStrdup(value);
        exec->errState = exec->state;
        memcpy(exec->errCounts, exec->counts,
         exec->comp->nbCounters * sizeof(int));
    }
    exec->state = exec->comp->states[trans->to];
    exec->transno = 0;
    if (trans->atom != NULL) {
        if (exec->inputStack != NULL) {
      exec->index++;
      if (exec->index < exec->inputStackNr) {
          value = exec->inputStack[exec->index].value;
          data = exec->inputStack[exec->index].data;
#ifdef DEBUG_PUSH
          printf("value loaded: %s\n", value);
#endif
      } else {
          value = NULL;
          data = NULL;
#ifdef DEBUG_PUSH
          printf("end of input\n");
#endif
      }
        } else {
      value = NULL;
      data = NULL;
#ifdef DEBUG_PUSH
      printf("end of input\n");
#endif
        }
    }
    goto progress;
      } else if (ret < 0) {
    exec->status = -4;
    break;
      }
  }
  if ((exec->transno != 0) || (exec->state->nbTrans == 0)) {
rollback:
            /*
       * if we didn't yet rollback on the current input
       * store the current state as the error state.
       */
      if ((progress) && (exec->state != NULL) &&
          (exec->state->type != XML_REGEXP_SINK_STATE)) {
          progress = 0;
    if (exec->errString != NULL)
        xmlFree(exec->errString);
    exec->errString = xmlStrdup(value);
    exec->errState = exec->state;
                if (exec->comp->nbCounters)
                    memcpy(exec->errCounts, exec->counts,
                           exec->comp->nbCounters * sizeof(int));
      }

      /*
       * Failed to find a way out
       */
      exec->determinist = 0;
      xmlFARegExecRollBack(exec);
      if ((exec->inputStack != NULL ) && (exec->status == 0)) {
    value = exec->inputStack[exec->index].value;
    data = exec->inputStack[exec->index].data;
#ifdef DEBUG_PUSH
    printf("value loaded: %s\n", value);
#endif
      }
  }
  continue;
progress:
        progress = 1;
  continue;
    }
    if (exec->status == 0) {
        return(exec->state->type == XML_REGEXP_FINAL_STATE);
    }
#ifdef DEBUG_ERR
    if (exec->status < 0) {
  testerr(exec);
    }
#endif
    return(exec->status);
}

/**
 * xmlRegExecPushString:
 * @exec: a regexp execution context or NULL to indicate the end
 * @value: a string token input
 * @data: data associated to the token to reuse in callbacks
 *
 * Push one input token in the execution context
 *
 * Returns: 1 if the regexp reached a final state, 0 if non-final, and
 *     a negative value in case of error.
 */
int
xmlRegExecPushString(xmlRegExecCtxtPtr exec, const xmlChar *value,
               void *data) {
    return(xmlRegExecPushStringInternal(exec, value, data, 0));
}

/**
 * xmlRegExecPushString2:
 * @exec: a regexp execution context or NULL to indicate the end
 * @value: the first string token input
 * @value2: the second string token input
 * @data: data associated to the token to reuse in callbacks
 *
 * Push one input token in the execution context
 *
 * Returns: 1 if the regexp reached a final state, 0 if non-final, and
 *     a negative value in case of error.
 */
int
xmlRegExecPushString2(xmlRegExecCtxtPtr exec, const xmlChar *value,
                      const xmlChar *value2, void *data) {
    xmlChar buf[150];
    int lenn, lenp, ret;
    xmlChar *str;

    if (exec == NULL)
  return(-1);
    if (exec->comp == NULL)
  return(-1);
    if (exec->status != 0)
  return(exec->status);

    if (value2 == NULL)
        return(xmlRegExecPushString(exec, value, data));

    lenn = strlen((char *) value2);
    lenp = strlen((char *) value);

    if (150 < lenn + lenp + 2) {
  str = (xmlChar *) xmlMallocAtomic(lenn + lenp + 2);
  if (str == NULL) {
      exec->status = -1;
      return(-1);
  }
    } else {
  str = buf;
    }
    memcpy(&str[0], value, lenp);
    str[lenp] = XML_REG_STRING_SEPARATOR;
    memcpy(&str[lenp + 1], value2, lenn);
    str[lenn + lenp + 1] = 0;

    if (exec->comp->compact != NULL)
  ret = xmlRegCompactPushString(exec, exec->comp, str, data);
    else
        ret = xmlRegExecPushStringInternal(exec, str, data, 1);

    if (str != buf)
        xmlFree(str);
    return(ret);
}

/**
 * xmlRegExecGetValues:
 * @exec: a regexp execution context
 * @err: error extraction or normal one
 * @nbval: pointer to the number of accepted values IN/OUT
 * @nbneg: return number of negative transitions
 * @values: pointer to the array of acceptable values
 * @terminal: return value if this was a terminal state
 *
 * Extract information from the regexp execution, internal routine to
 * implement xmlRegExecNextValues() and xmlRegExecErrInfo()
 *
 * Returns: 0 in case of success or -1 in case of error.
 */
static int
xmlRegExecGetValues(xmlRegExecCtxtPtr exec, int err,
                    int *nbval, int *nbneg,
        xmlChar **values, int *terminal) {
    int maxval;
    int nb = 0;

    if ((exec == NULL) || (nbval == NULL) || (nbneg == NULL) ||
        (values == NULL) || (*nbval <= 0))
        return(-1);

    maxval = *nbval;
    *nbval = 0;
    *nbneg = 0;
    if ((exec->comp != NULL) && (exec->comp->compact != NULL)) {
        xmlRegexpPtr comp;
  int target, i, state;

        comp = exec->comp;

  if (err) {
      if (exec->errStateNo == -1) return(-1);
      state = exec->errStateNo;
  } else {
      state = exec->index;
  }
  if (terminal != NULL) {
      if (comp->compact[state * (comp->nbstrings + 1)] ==
          XML_REGEXP_FINAL_STATE)
    *terminal = 1;
      else
    *terminal = 0;
  }
  for (i = 0;(i < comp->nbstrings) && (nb < maxval);i++) {
      target = comp->compact[state * (comp->nbstrings + 1) + i + 1];
      if ((target > 0) && (target <= comp->nbstates) &&
          (comp->compact[(target - 1) * (comp->nbstrings + 1)] !=
     XML_REGEXP_SINK_STATE)) {
          values[nb++] = comp->stringMap[i];
    (*nbval)++;
      }
  }
  for (i = 0;(i < comp->nbstrings) && (nb < maxval);i++) {
      target = comp->compact[state * (comp->nbstrings + 1) + i + 1];
      if ((target > 0) && (target <= comp->nbstates) &&
          (comp->compact[(target - 1) * (comp->nbstrings + 1)] ==
     XML_REGEXP_SINK_STATE)) {
          values[nb++] = comp->stringMap[i];
    (*nbneg)++;
      }
  }
    } else {
        int transno;
  xmlRegTransPtr trans;
  xmlRegAtomPtr atom;
  xmlRegStatePtr state;

  if (terminal != NULL) {
      if (exec->state->type == XML_REGEXP_FINAL_STATE)
    *terminal = 1;
      else
    *terminal = 0;
  }

  if (err) {
      if (exec->errState == NULL) return(-1);
      state = exec->errState;
  } else {
      if (exec->state == NULL) return(-1);
      state = exec->state;
  }
  for (transno = 0;
       (transno < state->nbTrans) && (nb < maxval);
       transno++) {
      trans = &state->trans[transno];
      if (trans->to < 0)
    continue;
      atom = trans->atom;
      if ((atom == NULL) || (atom->valuep == NULL))
    continue;
      if (trans->count == REGEXP_ALL_LAX_COUNTER) {
          /* this should not be reached but ... */
          TODO;
      } else if (trans->count == REGEXP_ALL_COUNTER) {
          /* this should not be reached but ... */
          TODO;
      } else if (trans->counter >= 0) {
    xmlRegCounterPtr counter = NULL;
    int count;

    if (err)
        count = exec->errCounts[trans->counter];
    else
        count = exec->counts[trans->counter];
    if (exec->comp != NULL)
        counter = &exec->comp->counters[trans->counter];
    if ((counter == NULL) || (count < counter->max)) {
        if (atom->neg)
      values[nb++] = (xmlChar *) atom->valuep2;
        else
      values[nb++] = (xmlChar *) atom->valuep;
        (*nbval)++;
    }
      } else {
                if ((exec->comp != NULL) && (exec->comp->states[trans->to] != NULL) &&
        (exec->comp->states[trans->to]->type !=
         XML_REGEXP_SINK_STATE)) {
        if (atom->neg)
      values[nb++] = (xmlChar *) atom->valuep2;
        else
      values[nb++] = (xmlChar *) atom->valuep;
        (*nbval)++;
    }
      }
  }
  for (transno = 0;
       (transno < state->nbTrans) && (nb < maxval);
       transno++) {
      trans = &state->trans[transno];
      if (trans->to < 0)
    continue;
      atom = trans->atom;
      if ((atom == NULL) || (atom->valuep == NULL))
    continue;
      if (trans->count == REGEXP_ALL_LAX_COUNTER) {
          continue;
      } else if (trans->count == REGEXP_ALL_COUNTER) {
          continue;
      } else if (trans->counter >= 0) {
          continue;
      } else {
                if ((exec->comp->states[trans->to] != NULL) &&
        (exec->comp->states[trans->to]->type ==
         XML_REGEXP_SINK_STATE)) {
        if (atom->neg)
      values[nb++] = (xmlChar *) atom->valuep2;
        else
      values[nb++] = (xmlChar *) atom->valuep;
        (*nbneg)++;
    }
      }
  }
    }
    return(0);
}

/**
 * xmlRegExecNextValues:
 * @exec: a regexp execution context
 * @nbval: pointer to the number of accepted values IN/OUT
 * @nbneg: return number of negative transitions
 * @values: pointer to the array of acceptable values
 * @terminal: return value if this was a terminal state
 *
 * Extract information from the regexp execution,
 * the parameter @values must point to an array of @nbval string pointers
 * on return nbval will contain the number of possible strings in that
 * state and the @values array will be updated with them. The string values
 * returned will be freed with the @exec context and don't need to be
 * deallocated.
 *
 * Returns: 0 in case of success or -1 in case of error.
 */
int
xmlRegExecNextValues(xmlRegExecCtxtPtr exec, int *nbval, int *nbneg,
                     xmlChar **values, int *terminal) {
    return(xmlRegExecGetValues(exec, 0, nbval, nbneg, values, terminal));
}

/**
 * xmlRegExecErrInfo:
 * @exec: a regexp execution context generating an error
 * @string: return value for the error string
 * @nbval: pointer to the number of accepted values IN/OUT
 * @nbneg: return number of negative transitions
 * @values: pointer to the array of acceptable values
 * @terminal: return value if this was a terminal state
 *
 * Extract error information from the regexp execution, the parameter
 * @string will be updated with the value pushed and not accepted,
 * the parameter @values must point to an array of @nbval string pointers
 * on return nbval will contain the number of possible strings in that
 * state and the @values array will be updated with them. The string values
 * returned will be freed with the @exec context and don't need to be
 * deallocated.
 *
 * Returns: 0 in case of success or -1 in case of error.
 */
int
xmlRegExecErrInfo(xmlRegExecCtxtPtr exec, const xmlChar **string,
                  int *nbval, int *nbneg, xmlChar **values, int *terminal) {
    if (exec == NULL)
        return(-1);
    if (string != NULL) {
        if (exec->status != 0)
      *string = exec->errString;
  else
      *string = NULL;
    }
    return(xmlRegExecGetValues(exec, 1, nbval, nbneg, values, terminal));
}

#ifdef DEBUG_ERR
static void testerr(xmlRegExecCtxtPtr exec) {
    const xmlChar *string;
    xmlChar *values[5];
    int nb = 5;
    int nbneg;
    int terminal;
    xmlRegExecErrInfo(exec, &string, &nb, &nbneg, &values[0], &terminal);
}
#endif

#if 0
static int
xmlRegExecPushChar(xmlRegExecCtxtPtr exec, int UCS) {
    xmlRegTransPtr trans;
    xmlRegAtomPtr atom;
    int ret;
    int codepoint, len;

    if (exec == NULL)
  return(-1);
    if (exec->status != 0)
  return(exec->status);

    while ((exec->status == 0) &&
     ((exec->inputString[exec->index] != 0) ||
      (exec->state->type != XML_REGEXP_FINAL_STATE))) {

  /*
   * End of input on non-terminal state, rollback, however we may
   * still have epsilon like transition for counted transitions
   * on counters, in that case don't break too early.
   */
  if ((exec->inputString[exec->index] == 0) && (exec->counts == NULL))
      goto rollback;

  exec->transcount = 0;
  for (;exec->transno < exec->state->nbTrans;exec->transno++) {
      trans = &exec->state->trans[exec->transno];
      if (trans->to < 0)
    continue;
      atom = trans->atom;
      ret = 0;
      if (trans->count >= 0) {
    int count;
    xmlRegCounterPtr counter;

    /*
     * A counted transition.
     */

    count = exec->counts[trans->count];
    counter = &exec->comp->counters[trans->count];
#ifdef DEBUG_REGEXP_EXEC
    printf("testing count %d: val %d, min %d, max %d\n",
           trans->count, count, counter->min,  counter->max);
#endif
    ret = ((count >= counter->min) && (count <= counter->max));
      } else if (atom == NULL) {
    fprintf(stderr, "epsilon transition left at runtime\n");
    exec->status = -2;
    break;
      } else if (exec->inputString[exec->index] != 0) {
                codepoint = CUR_SCHAR(&(exec->inputString[exec->index]), len);
    ret = xmlRegCheckCharacter(atom, codepoint);
    if ((ret == 1) && (atom->min > 0) && (atom->max > 0)) {
        xmlRegStatePtr to = exec->comp->states[trans->to];

        /*
         * this is a multiple input sequence
         */
        if (exec->state->nbTrans > exec->transno + 1) {
      xmlFARegExecSave(exec);
        }
        exec->transcount = 1;
        do {
      /*
       * Try to progress as much as possible on the input
       */
      if (exec->transcount == atom->max) {
          break;
      }
      exec->index += len;
      /*
       * End of input: stop here
       */
      if (exec->inputString[exec->index] == 0) {
          exec->index -= len;
          break;
      }
      if (exec->transcount >= atom->min) {
          int transno = exec->transno;
          xmlRegStatePtr state = exec->state;

          /*
           * The transition is acceptable save it
           */
          exec->transno = -1; /* trick */
          exec->state = to;
          xmlFARegExecSave(exec);
          exec->transno = transno;
          exec->state = state;
      }
      codepoint = CUR_SCHAR(&(exec->inputString[exec->index]),
                      len);
      ret = xmlRegCheckCharacter(atom, codepoint);
      exec->transcount++;
        } while (ret == 1);
        if (exec->transcount < atom->min)
      ret = 0;

        /*
         * If the last check failed but one transition was found
         * possible, rollback
         */
        if (ret < 0)
      ret = 0;
        if (ret == 0) {
      goto rollback;
        }
    }
      }
      if (ret == 1) {
    if (exec->state->nbTrans > exec->transno + 1) {
        xmlFARegExecSave(exec);
    }
    /*
     * restart count for expressions like this ((abc){2})*
     */
    if (trans->count >= 0) {
#ifdef DEBUG_REGEXP_EXEC
        printf("Reset count %d\n", trans->count);
#endif
        exec->counts[trans->count] = 0;
    }
    if (trans->counter >= 0) {
#ifdef DEBUG_REGEXP_EXEC
        printf("Increasing count %d\n", trans->counter);
#endif
        exec->counts[trans->counter]++;
    }
#ifdef DEBUG_REGEXP_EXEC
    printf("entering state %d\n", trans->to);
#endif
    exec->state = exec->comp->states[trans->to];
    exec->transno = 0;
    if (trans->atom != NULL) {
        exec->index += len;
    }
    goto progress;
      } else if (ret < 0) {
    exec->status = -4;
    break;
      }
  }
  if ((exec->transno != 0) || (exec->state->nbTrans == 0)) {
rollback:
      /*
       * Failed to find a way out
       */
      exec->determinist = 0;
      xmlFARegExecRollBack(exec);
  }
progress:
  continue;
    }
}
#endif
/************************************************************************
 *                  *
 *  Parser for the Schemas Datatype Regular Expressions   *
 *  http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#regexs  *
 *                  *
 ************************************************************************/

/**
 * xmlFAIsChar:
 * @ctxt:  a regexp parser context
 *
 * [10]   Char   ::=   [^.\?*+()|#x5B#x5D]
 */
static int
xmlFAIsChar(xmlRegParserCtxtPtr ctxt) {
    int cur;
    int len;

    cur = CUR_SCHAR(ctxt->cur, len);
    if ((cur == '.') || (cur == '\\') || (cur == '?') ||
  (cur == '*') || (cur == '+') || (cur == '(') ||
  (cur == ')') || (cur == '|') || (cur == 0x5B) ||
  (cur == 0x5D) || (cur == 0))
  return(-1);
    return(cur);
}

/**
 * xmlFAParseCharProp:
 * @ctxt:  a regexp parser context
 *
 * [27]   charProp   ::=   IsCategory | IsBlock
 * [28]   IsCategory ::= Letters | Marks | Numbers | Punctuation |
 *                       Separators | Symbols | Others
 * [29]   Letters   ::=   'L' [ultmo]?
 * [30]   Marks   ::=   'M' [nce]?
 * [31]   Numbers   ::=   'N' [dlo]?
 * [32]   Punctuation   ::=   'P' [cdseifo]?
 * [33]   Separators   ::=   'Z' [slp]?
 * [34]   Symbols   ::=   'S' [mcko]?
 * [35]   Others   ::=   'C' [cfon]?
 * [36]   IsBlock   ::=   'Is' [a-zA-Z0-9#x2D]+
 */
static void
xmlFAParseCharProp(xmlRegParserCtxtPtr ctxt) {
    int cur;
    xmlRegAtomType type = (xmlRegAtomType) 0;
    xmlChar *blockName = NULL;

    cur = CUR;
    if (cur == 'L') {
  NEXT;
  cur = CUR;
  if (cur == 'u') {
      NEXT;
      type = XML_REGEXP_LETTER_UPPERCASE;
  } else if (cur == 'l') {
      NEXT;
      type = XML_REGEXP_LETTER_LOWERCASE;
  } else if (cur == 't') {
      NEXT;
      type = XML_REGEXP_LETTER_TITLECASE;
  } else if (cur == 'm') {
      NEXT;
      type = XML_REGEXP_LETTER_MODIFIER;
  } else if (cur == 'o') {
      NEXT;
      type = XML_REGEXP_LETTER_OTHERS;
  } else {
      type = XML_REGEXP_LETTER;
  }
    } else if (cur == 'M') {
  NEXT;
  cur = CUR;
  if (cur == 'n') {
      NEXT;
      /* nonspacing */
      type = XML_REGEXP_MARK_NONSPACING;
  } else if (cur == 'c') {
      NEXT;
      /* spacing combining */
      type = XML_REGEXP_MARK_SPACECOMBINING;
  } else if (cur == 'e') {
      NEXT;
      /* enclosing */
      type = XML_REGEXP_MARK_ENCLOSING;
  } else {
      /* all marks */
      type = XML_REGEXP_MARK;
  }
    } else if (cur == 'N') {
  NEXT;
  cur = CUR;
  if (cur == 'd') {
      NEXT;
      /* digital */
      type = XML_REGEXP_NUMBER_DECIMAL;
  } else if (cur == 'l') {
      NEXT;
      /* letter */
      type = XML_REGEXP_NUMBER_LETTER;
  } else if (cur == 'o') {
      NEXT;
      /* other */
      type = XML_REGEXP_NUMBER_OTHERS;
  } else {
      /* all numbers */
      type = XML_REGEXP_NUMBER;
  }
    } else if (cur == 'P') {
  NEXT;
  cur = CUR;
  if (cur == 'c') {
      NEXT;
      /* connector */
      type = XML_REGEXP_PUNCT_CONNECTOR;
  } else if (cur == 'd') {
      NEXT;
      /* dash */
      type = XML_REGEXP_PUNCT_DASH;
  } else if (cur == 's') {
      NEXT;
      /* open */
      type = XML_REGEXP_PUNCT_OPEN;
  } else if (cur == 'e') {
      NEXT;
      /* close */
      type = XML_REGEXP_PUNCT_CLOSE;
  } else if (cur == 'i') {
      NEXT;
      /* initial quote */
      type = XML_REGEXP_PUNCT_INITQUOTE;
  } else if (cur == 'f') {
      NEXT;
      /* final quote */
      type = XML_REGEXP_PUNCT_FINQUOTE;
  } else if (cur == 'o') {
      NEXT;
      /* other */
      type = XML_REGEXP_PUNCT_OTHERS;
  } else {
      /* all punctuation */
      type = XML_REGEXP_PUNCT;
  }
    } else if (cur == 'Z') {
  NEXT;
  cur = CUR;
  if (cur == 's') {
      NEXT;
      /* space */
      type = XML_REGEXP_SEPAR_SPACE;
  } else if (cur == 'l') {
      NEXT;
      /* line */
      type = XML_REGEXP_SEPAR_LINE;
  } else if (cur == 'p') {
      NEXT;
      /* paragraph */
      type = XML_REGEXP_SEPAR_PARA;
  } else {
      /* all separators */
      type = XML_REGEXP_SEPAR;
  }
    } else if (cur == 'S') {
  NEXT;
  cur = CUR;
  if (cur == 'm') {
      NEXT;
      type = XML_REGEXP_SYMBOL_MATH;
      /* math */
  } else if (cur == 'c') {
      NEXT;
      type = XML_REGEXP_SYMBOL_CURRENCY;
      /* currency */
  } else if (cur == 'k') {
      NEXT;
      type = XML_REGEXP_SYMBOL_MODIFIER;
      /* modifiers */
  } else if (cur == 'o') {
      NEXT;
      type = XML_REGEXP_SYMBOL_OTHERS;
      /* other */
  } else {
      /* all symbols */
      type = XML_REGEXP_SYMBOL;
  }
    } else if (cur == 'C') {
  NEXT;
  cur = CUR;
  if (cur == 'c') {
      NEXT;
      /* control */
      type = XML_REGEXP_OTHER_CONTROL;
  } else if (cur == 'f') {
      NEXT;
      /* format */
      type = XML_REGEXP_OTHER_FORMAT;
  } else if (cur == 'o') {
      NEXT;
      /* private use */
      type = XML_REGEXP_OTHER_PRIVATE;
  } else if (cur == 'n') {
      NEXT;
      /* not assigned */
      type = XML_REGEXP_OTHER_NA;
  } else {
      /* all others */
      type = XML_REGEXP_OTHER;
  }
    } else if (cur == 'I') {
  const xmlChar *start;
  NEXT;
  cur = CUR;
  if (cur != 's') {
      ERROR("IsXXXX expected");
      return;
  }
  NEXT;
  start = ctxt->cur;
  cur = CUR;
  if (((cur >= 'a') && (cur <= 'z')) ||
      ((cur >= 'A') && (cur <= 'Z')) ||
      ((cur >= '0') && (cur <= '9')) ||
      (cur == 0x2D)) {
      NEXT;
      cur = CUR;
      while (((cur >= 'a') && (cur <= 'z')) ||
    ((cur >= 'A') && (cur <= 'Z')) ||
    ((cur >= '0') && (cur <= '9')) ||
    (cur == 0x2D)) {
    NEXT;
    cur = CUR;
      }
  }
  type = XML_REGEXP_BLOCK_NAME;
  blockName = xmlStrndup(start, ctxt->cur - start);
    } else {
  ERROR("Unknown char property");
  return;
    }
    if (ctxt->atom == NULL) {
  ctxt->atom = xmlRegNewAtom(ctxt, type);
        if (ctxt->atom == NULL) {
            xmlFree(blockName);
            return;
        }
  ctxt->atom->valuep = blockName;
    } else if (ctxt->atom->type == XML_REGEXP_RANGES) {
        if (xmlRegAtomAddRange(ctxt, ctxt->atom, ctxt->neg,
                               type, 0, 0, blockName) == NULL) {
            xmlFree(blockName);
        }
    }
}

static int parse_escaped_codeunit(xmlRegParserCtxtPtr ctxt)
{
    int val = 0, i, cur;
    for (i = 0; i < 4; i++) {
  NEXT;
  val *= 16;
  cur = CUR;
  if (cur >= '0' && cur <= '9') {
      val += cur - '0';
  } else if (cur >= 'A' && cur <= 'F') {
      val += cur - 'A' + 10;
  } else if (cur >= 'a' && cur <= 'f') {
      val += cur - 'a' + 10;
  } else {
      ERROR("Expecting hex digit");
      return -1;
  }
    }
    return val;
}

static int parse_escaped_codepoint(xmlRegParserCtxtPtr ctxt)
{
    int val = parse_escaped_codeunit(ctxt);
    if (0xD800 <= val && val <= 0xDBFF) {
  NEXT;
  if (CUR == '\\') {
      NEXT;
      if (CUR == 'u') {
    int low = parse_escaped_codeunit(ctxt);
    if (0xDC00 <= low && low <= 0xDFFF) {
        return (val - 0xD800) * 0x400 + (low - 0xDC00) + 0x10000;
    }
      }
  }
  ERROR("Invalid low surrogate pair code unit");
  val = -1;
    }
    return val;
}

/**
 * xmlFAParseCharClassEsc:
 * @ctxt:  a regexp parser context
 *
 * [23] charClassEsc ::= ( SingleCharEsc | MultiCharEsc | catEsc | complEsc )
 * [24] SingleCharEsc ::= '\' [nrt\|.?*+(){}#x2D#x5B#x5D#x5E]
 * [25] catEsc   ::=   '\p{' charProp '}'
 * [26] complEsc ::=   '\P{' charProp '}'
 * [37] MultiCharEsc ::= '.' | ('\' [sSiIcCdDwW])
 */
static void
xmlFAParseCharClassEsc(xmlRegParserCtxtPtr ctxt) {
    int cur;

    if (CUR == '.') {
  if (ctxt->atom == NULL) {
      ctxt->atom = xmlRegNewAtom(ctxt, XML_REGEXP_ANYCHAR);
  } else if (ctxt->atom->type == XML_REGEXP_RANGES) {
      xmlRegAtomAddRange(ctxt, ctxt->atom, ctxt->neg,
             XML_REGEXP_ANYCHAR, 0, 0, NULL);
  }
  NEXT;
  return;
    }
    if (CUR != '\\') {
  ERROR("Escaped sequence: expecting \\");
  return;
    }
    NEXT;
    cur = CUR;
    if (cur == 'p') {
  NEXT;
  if (CUR != '{') {
      ERROR("Expecting '{'");
      return;
  }
  NEXT;
  xmlFAParseCharProp(ctxt);
  if (CUR != '}') {
      ERROR("Expecting '}'");
      return;
  }
  NEXT;
    } else if (cur == 'P') {
  NEXT;
  if (CUR != '{') {
      ERROR("Expecting '{'");
      return;
  }
  NEXT;
  xmlFAParseCharProp(ctxt);
        if (ctxt->atom != NULL)
      ctxt->atom->neg = 1;
  if (CUR != '}') {
      ERROR("Expecting '}'");
      return;
  }
  NEXT;
    } else if ((cur == 'n') || (cur == 'r') || (cur == 't') || (cur == '\\') ||
  (cur == '|') || (cur == '.') || (cur == '?') || (cur == '*') ||
  (cur == '+') || (cur == '(') || (cur == ')') || (cur == '{') ||
  (cur == '}') || (cur == 0x2D) || (cur == 0x5B) || (cur == 0x5D) ||
  (cur == 0x5E) ||

  /* Non-standard escape sequences:
   *                  Java 1.8|.NET Core 3.1|MSXML 6 */
  (cur == '!') ||     /*   +  |     +       |    +   */
  (cur == '"') ||     /*   +  |     +       |    +   */
  (cur == '#') ||     /*   +  |     +       |    +   */
  (cur == '$') ||     /*   +  |     +       |    +   */
  (cur == '%') ||     /*   +  |     +       |    +   */
  (cur == ',') ||     /*   +  |     +       |    +   */
  (cur == '/') ||     /*   +  |     +       |    +   */
  (cur == ':') ||     /*   +  |     +       |    +   */
  (cur == ';') ||     /*   +  |     +       |    +   */
  (cur == '=') ||     /*   +  |     +       |    +   */
  (cur == '>') ||     /*      |     +       |    +   */
  (cur == '@') ||     /*   +  |     +       |    +   */
  (cur == '`') ||     /*   +  |     +       |    +   */
  (cur == '~') ||     /*   +  |     +       |    +   */
  (cur == 'u')) {     /*      |     +       |    +   */
  if (ctxt->atom == NULL) {
      ctxt->atom = xmlRegNewAtom(ctxt, XML_REGEXP_CHARVAL);
      if (ctxt->atom != NULL) {
          switch (cur) {
        case 'n':
            ctxt->atom->codepoint = '\n';
      break;
        case 'r':
            ctxt->atom->codepoint = '\r';
      break;
        case 't':
            ctxt->atom->codepoint = '\t';
      break;
        case 'u':
      cur = parse_escaped_codepoint(ctxt);
      if (cur < 0) {
          return;
      }
      ctxt->atom->codepoint = cur;
      break;
        default:
      ctxt->atom->codepoint = cur;
    }
      }
  } else if (ctxt->atom->type == XML_REGEXP_RANGES) {
            switch (cur) {
                case 'n':
                    cur = '\n';
                    break;
                case 'r':
                    cur = '\r';
                    break;
                case 't':
                    cur = '\t';
                    break;
            }
      xmlRegAtomAddRange(ctxt, ctxt->atom, ctxt->neg,
             XML_REGEXP_CHARVAL, cur, cur, NULL);
  }
  NEXT;
    } else if ((cur == 's') || (cur == 'S') || (cur == 'i') || (cur == 'I') ||
  (cur == 'c') || (cur == 'C') || (cur == 'd') || (cur == 'D') ||
  (cur == 'w') || (cur == 'W')) {
  xmlRegAtomType type = XML_REGEXP_ANYSPACE;

  switch (cur) {
      case 's':
    type = XML_REGEXP_ANYSPACE;
    break;
      case 'S':
    type = XML_REGEXP_NOTSPACE;
    break;
      case 'i':
    type = XML_REGEXP_INITNAME;
    break;
      case 'I':
    type = XML_REGEXP_NOTINITNAME;
    break;
      case 'c':
    type = XML_REGEXP_NAMECHAR;
    break;
      case 'C':
    type = XML_REGEXP_NOTNAMECHAR;
    break;
      case 'd':
    type = XML_REGEXP_DECIMAL;
    break;
      case 'D':
    type = XML_REGEXP_NOTDECIMAL;
    break;
      case 'w':
    type = XML_REGEXP_REALCHAR;
    break;
      case 'W':
    type = XML_REGEXP_NOTREALCHAR;
    break;
  }
  NEXT;
  if (ctxt->atom == NULL) {
      ctxt->atom = xmlRegNewAtom(ctxt, type);
  } else if (ctxt->atom->type == XML_REGEXP_RANGES) {
      xmlRegAtomAddRange(ctxt, ctxt->atom, ctxt->neg,
             type, 0, 0, NULL);
  }
    } else {
  ERROR("Wrong escape sequence, misuse of character '\\'");
    }
}

/**
 * xmlFAParseCharRange:
 * @ctxt:  a regexp parser context
 *
 * [17]   charRange   ::=     seRange | XmlCharRef | XmlCharIncDash
 * [18]   seRange   ::=   charOrEsc '-' charOrEsc
 * [20]   charOrEsc   ::=   XmlChar | SingleCharEsc
 * [21]   XmlChar   ::=   [^\#x2D#x5B#x5D]
 * [22]   XmlCharIncDash   ::=   [^\#x5B#x5D]
 */
static void
xmlFAParseCharRange(xmlRegParserCtxtPtr ctxt) {
    int cur, len;
    int start = -1;
    int end = -1;

    if (CUR == '\0') {
        ERROR("Expecting ']'");
  return;
    }

    cur = CUR;
    if (cur == '\\') {
  NEXT;
  cur = CUR;
  switch (cur) {
      case 'n': start = 0xA; break;
      case 'r': start = 0xD; break;
      case 't': start = 0x9; break;
      case '\\': case '|': case '.': case '-': case '^': case '?':
      case '*': case '+': case '{': case '}': case '(': case ')':
      case '[': case ']':
    start = cur; break;
      default:
    ERROR("Invalid escape value");
    return;
  }
  end = start;
        len = 1;
    } else if ((cur != 0x5B) && (cur != 0x5D)) {
        end = start = CUR_SCHAR(ctxt->cur, len);
    } else {
  ERROR("Expecting a char range");
  return;
    }
    /*
     * Since we are "inside" a range, we can assume ctxt->cur is past
     * the start of ctxt->string, and PREV should be safe
     */
    if ((start == '-') && (NXT(1) != ']') && (PREV != '[') && (PREV != '^')) {
  NEXTL(len);
  return;
    }
    NEXTL(len);
    cur = CUR;
    if ((cur != '-') || (NXT(1) == '[') || (NXT(1) == ']')) {
        xmlRegAtomAddRange(ctxt, ctxt->atom, ctxt->neg,
                  XML_REGEXP_CHARVAL, start, end, NULL);
  return;
    }
    NEXT;
    cur = CUR;
    if (cur == '\\') {
  NEXT;
  cur = CUR;
  switch (cur) {
      case 'n': end = 0xA; break;
      case 'r': end = 0xD; break;
      case 't': end = 0x9; break;
      case '\\': case '|': case '.': case '-': case '^': case '?':
      case '*': case '+': case '{': case '}': case '(': case ')':
      case '[': case ']':
    end = cur; break;
      default:
    ERROR("Invalid escape value");
    return;
  }
        len = 1;
    } else if ((cur != '\0') && (cur != 0x5B) && (cur != 0x5D)) {
        end = CUR_SCHAR(ctxt->cur, len);
    } else {
  ERROR("Expecting the end of a char range");
  return;
    }

    /* TODO check that the values are acceptable character ranges for XML */
    if (end < start) {
  ERROR("End of range is before start of range");
    } else {
        NEXTL(len);
        xmlRegAtomAddRange(ctxt, ctxt->atom, ctxt->neg,
               XML_REGEXP_CHARVAL, start, end, NULL);
    }
    return;
}

/**
 * xmlFAParsePosCharGroup:
 * @ctxt:  a regexp parser context
 *
 * [14]   posCharGroup ::= ( charRange | charClassEsc  )+
 */
static void
xmlFAParsePosCharGroup(xmlRegParserCtxtPtr ctxt) {
    do {
  if (CUR == '\\') {
      xmlFAParseCharClassEsc(ctxt);
  } else {
      xmlFAParseCharRange(ctxt);
  }
    } while ((CUR != ']') && (CUR != '-') &&
             (CUR != 0) && (ctxt->error == 0));
}

/**
 * xmlFAParseCharGroup:
 * @ctxt:  a regexp parser context
 *
 * [13]   charGroup    ::= posCharGroup | negCharGroup | charClassSub
 * [15]   negCharGroup ::= '^' posCharGroup
 * [16]   charClassSub ::= ( posCharGroup | negCharGroup ) '-' charClassExpr
 * [12]   charClassExpr ::= '[' charGroup ']'
 */
static void
xmlFAParseCharGroup(xmlRegParserCtxtPtr ctxt) {
    int neg = ctxt->neg;

    if (CUR == '^') {
  NEXT;
  ctxt->neg = !ctxt->neg;
  xmlFAParsePosCharGroup(ctxt);
  ctxt->neg = neg;
    }
    while ((CUR != ']') && (ctxt->error == 0)) {
  if ((CUR == '-') && (NXT(1) == '[')) {
      NEXT; /* eat the '-' */
      NEXT; /* eat the '[' */
      ctxt->neg = 2;
      xmlFAParseCharGroup(ctxt);
      ctxt->neg = neg;
      if (CUR == ']') {
    NEXT;
      } else {
    ERROR("charClassExpr: ']' expected");
      }
      break;
  } else {
      xmlFAParsePosCharGroup(ctxt);
  }
    }
}

/**
 * xmlFAParseCharClass:
 * @ctxt:  a regexp parser context
 *
 * [11]   charClass   ::=     charClassEsc | charClassExpr
 * [12]   charClassExpr   ::=   '[' charGroup ']'
 */
static void
xmlFAParseCharClass(xmlRegParserCtxtPtr ctxt) {
    if (CUR == '[') {
  NEXT;
  ctxt->atom = xmlRegNewAtom(ctxt, XML_REGEXP_RANGES);
  if (ctxt->atom == NULL)
      return;
  xmlFAParseCharGroup(ctxt);
  if (CUR == ']') {
      NEXT;
  } else {
      ERROR("xmlFAParseCharClass: ']' expected");
  }
    } else {
  xmlFAParseCharClassEsc(ctxt);
    }
}

/**
 * xmlFAParseQuantExact:
 * @ctxt:  a regexp parser context
 *
 * [8]   QuantExact   ::=   [0-9]+
 *
 * Returns 0 if success or -1 in case of error
 */
static int
xmlFAParseQuantExact(xmlRegParserCtxtPtr ctxt) {
    int ret = 0;
    int ok = 0;
    int overflow = 0;

    while ((CUR >= '0') && (CUR <= '9')) {
        if (ret > INT_MAX / 10) {
            overflow = 1;
        } else {
            int digit = CUR - '0';

            ret *= 10;
            if (ret > INT_MAX - digit)
                overflow = 1;
            else
                ret += digit;
        }
  ok = 1;
  NEXT;
    }
    if ((ok != 1) || (overflow == 1)) {
  return(-1);
    }
    return(ret);
}

/**
 * xmlFAParseQuantifier:
 * @ctxt:  a regexp parser context
 *
 * [4]   quantifier   ::=   [?*+] | ( '{' quantity '}' )
 * [5]   quantity   ::=   quantRange | quantMin | QuantExact
 * [6]   quantRange   ::=   QuantExact ',' QuantExact
 * [7]   quantMin   ::=   QuantExact ','
 * [8]   QuantExact   ::=   [0-9]+
 */
static int
xmlFAParseQuantifier(xmlRegParserCtxtPtr ctxt) {
    int cur;

    cur = CUR;
    if ((cur == '?') || (cur == '*') || (cur == '+')) {
  if (ctxt->atom != NULL) {
      if (cur == '?')
    ctxt->atom->quant = XML_REGEXP_QUANT_OPT;
      else if (cur == '*')
    ctxt->atom->quant = XML_REGEXP_QUANT_MULT;
      else if (cur == '+')
    ctxt->atom->quant = XML_REGEXP_QUANT_PLUS;
  }
  NEXT;
  return(1);
    }
    if (cur == '{') {
  int min = 0, max = 0;

  NEXT;
  cur = xmlFAParseQuantExact(ctxt);
  if (cur >= 0)
      min = cur;
        else {
            ERROR("Improper quantifier");
        }
  if (CUR == ',') {
      NEXT;
      if (CUR == '}')
          max = INT_MAX;
      else {
          cur = xmlFAParseQuantExact(ctxt);
          if (cur >= 0)
        max = cur;
    else {
        ERROR("Improper quantifier");
    }
      }
  }
  if (CUR == '}') {
      NEXT;
  } else {
      ERROR("Unterminated quantifier");
  }
  if (max == 0)
      max = min;
  if (ctxt->atom != NULL) {
      ctxt->atom->quant = XML_REGEXP_QUANT_RANGE;
      ctxt->atom->min = min;
      ctxt->atom->max = max;
  }
  return(1);
    }
    return(0);
}

/**
 * xmlFAParseAtom:
 * @ctxt:  a regexp parser context
 *
 * [9]   atom   ::=   Char | charClass | ( '(' regExp ')' )
 */
static int
xmlFAParseAtom(xmlRegParserCtxtPtr ctxt) {
    int codepoint, len;

    codepoint = xmlFAIsChar(ctxt);
    if (codepoint > 0) {
  ctxt->atom = xmlRegNewAtom(ctxt, XML_REGEXP_CHARVAL);
  if (ctxt->atom == NULL)
      return(-1);
  codepoint = CUR_SCHAR(ctxt->cur, len);
  ctxt->atom->codepoint = codepoint;
  NEXTL(len);
  return(1);
    } else if (CUR == '|') {
  return(0);
    } else if (CUR == 0) {
  return(0);
    } else if (CUR == ')') {
  return(0);
    } else if (CUR == '(') {
  xmlRegStatePtr start, oldend, start0;

  NEXT;
        if (ctxt->depth >= 50) {
      ERROR("xmlFAParseAtom: maximum nesting depth exceeded");
            return(-1);
        }
  /*
   * this extra Epsilon transition is needed if we count with 0 allowed
   * unfortunately this can't be known at that point
   */
  xmlFAGenerateEpsilonTransition(ctxt, ctxt->state, NULL);
  start0 = ctxt->state;
  xmlFAGenerateEpsilonTransition(ctxt, ctxt->state, NULL);
  start = ctxt->state;
  oldend = ctxt->end;
  ctxt->end = NULL;
  ctxt->atom = NULL;
        ctxt->depth++;
  xmlFAParseRegExp(ctxt, 0);
        ctxt->depth--;
  if (CUR == ')') {
      NEXT;
  } else {
      ERROR("xmlFAParseAtom: expecting ')'");
  }
  ctxt->atom = xmlRegNewAtom(ctxt, XML_REGEXP_SUBREG);
  if (ctxt->atom == NULL)
      return(-1);
  ctxt->atom->start = start;
  ctxt->atom->start0 = start0;
  ctxt->atom->stop = ctxt->state;
  ctxt->end = oldend;
  return(1);
    } else if ((CUR == '[') || (CUR == '\\') || (CUR == '.')) {
  xmlFAParseCharClass(ctxt);
  return(1);
    }
    return(0);
}

/**
 * xmlFAParsePiece:
 * @ctxt:  a regexp parser context
 *
 * [3]   piece   ::=   atom quantifier?
 */
static int
xmlFAParsePiece(xmlRegParserCtxtPtr ctxt) {
    int ret;

    ctxt->atom = NULL;
    ret = xmlFAParseAtom(ctxt);
    if (ret == 0)
  return(0);
    if (ctxt->atom == NULL) {
  ERROR("internal: no atom generated");
    }
    xmlFAParseQuantifier(ctxt);
    return(1);
}

/**
 * xmlFAParseBranch:
 * @ctxt:  a regexp parser context
 * @to: optional target to the end of the branch
 *
 * @to is used to optimize by removing duplicate path in automata
 * in expressions like (a|b)(c|d)
 *
 * [2]   branch   ::=   piece*
 */
static int
xmlFAParseBranch(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr to) {
    xmlRegStatePtr previous;
    int ret;

    previous = ctxt->state;
    ret = xmlFAParsePiece(ctxt);
    if (ret == 0) {
        /* Empty branch */
  xmlFAGenerateEpsilonTransition(ctxt, previous, to);
    } else {
  if (xmlFAGenerateTransitions(ctxt, previous,
          (CUR=='|' || CUR==')' || CUR==0) ? to : NULL,
                ctxt->atom) < 0) {
            xmlRegFreeAtom(ctxt->atom);
            ctxt->atom = NULL;
      return(-1);
        }
  previous = ctxt->state;
  ctxt->atom = NULL;
    }
    while ((ret != 0) && (ctxt->error == 0)) {
  ret = xmlFAParsePiece(ctxt);
  if (ret != 0) {
      if (xmlFAGenerateTransitions(ctxt, previous,
              (CUR=='|' || CUR==')' || CUR==0) ? to : NULL,
                    ctxt->atom) < 0) {
                xmlRegFreeAtom(ctxt->atom);
                ctxt->atom = NULL;
                return(-1);
            }
      previous = ctxt->state;
      ctxt->atom = NULL;
  }
    }
    return(0);
}

/**
 * xmlFAParseRegExp:
 * @ctxt:  a regexp parser context
 * @top:  is this the top-level expression ?
 *
 * [1]   regExp   ::=     branch  ( '|' branch )*
 */
static void
xmlFAParseRegExp(xmlRegParserCtxtPtr ctxt, int top) {
    xmlRegStatePtr start, end;

    /* if not top start should have been generated by an epsilon trans */
    start = ctxt->state;
    ctxt->end = NULL;
    xmlFAParseBranch(ctxt, NULL);
    if (top) {
#ifdef DEBUG_REGEXP_GRAPH
  printf("State %d is final\n", ctxt->state->no);
#endif
  ctxt->state->type = XML_REGEXP_FINAL_STATE;
    }
    if (CUR != '|') {
  ctxt->end = ctxt->state;
  return;
    }
    end = ctxt->state;
    while ((CUR == '|') && (ctxt->error == 0)) {
  NEXT;
  ctxt->state = start;
  ctxt->end = NULL;
  xmlFAParseBranch(ctxt, end);
    }
    if (!top) {
  ctxt->state = end;
  ctxt->end = end;
    }
}

/************************************************************************
 *                  *
 *      The basic API         *
 *                  *
 ************************************************************************/

/**
 * xmlRegexpPrint:
 * @output: the file for the output debug
 * @regexp: the compiled regexp
 *
 * Print the content of the compiled regular expression
 */
void
xmlRegexpPrint(FILE *output, xmlRegexpPtr regexp) {
    int i;

    if (output == NULL)
        return;
    fprintf(output, " regexp: ");
    if (regexp == NULL) {
  fprintf(output, "NULL\n");
  return;
    }
    fprintf(output, "'%s' ", regexp->string);
    fprintf(output, "\n");
    fprintf(output, "%d atoms:\n", regexp->nbAtoms);
    for (i = 0;i < regexp->nbAtoms; i++) {
  fprintf(output, " %02d ", i);
  xmlRegPrintAtom(output, regexp->atoms[i]);
    }
    fprintf(output, "%d states:", regexp->nbStates);
    fprintf(output, "\n");
    for (i = 0;i < regexp->nbStates; i++) {
  xmlRegPrintState(output, regexp->states[i]);
    }
    fprintf(output, "%d counters:\n", regexp->nbCounters);
    for (i = 0;i < regexp->nbCounters; i++) {
  fprintf(output, " %d: min %d max %d\n", i, regexp->counters[i].min,
                                    regexp->counters[i].max);
    }
}

/**
 * xmlRegexpCompile:
 * @regexp:  a regular expression string
 *
 * Parses a regular expression conforming to XML Schemas Part 2 Datatype
 * Appendix F and builds an automata suitable for testing strings against
 * that regular expression
 *
 * Returns the compiled expression or NULL in case of error
 */
xmlRegexpPtr
xmlRegexpCompile(const xmlChar *regexp) {
    xmlRegexpPtr ret = NULL;
    xmlRegParserCtxtPtr ctxt;

    ctxt = xmlRegNewParserCtxt(regexp);
    if (ctxt == NULL)
  return(NULL);

    /* initialize the parser */
    ctxt->state = xmlRegStatePush(ctxt);
    if (ctxt->state == NULL)
        goto error;
    ctxt->start = ctxt->state;
    ctxt->end = NULL;

    /* parse the expression building an automata */
    xmlFAParseRegExp(ctxt, 1);
    if (CUR != 0) {
  ERROR("xmlFAParseRegExp: extra characters");
    }
    if (ctxt->error != 0)
        goto error;
    ctxt->end = ctxt->state;
    ctxt->start->type = XML_REGEXP_START_STATE;
    ctxt->end->type = XML_REGEXP_FINAL_STATE;

    /* remove the Epsilon except for counted transitions */
    xmlFAEliminateEpsilonTransitions(ctxt);


    if (ctxt->error != 0)
        goto error;
    ret = xmlRegEpxFromParse(ctxt);

error:
    xmlRegFreeParserCtxt(ctxt);
    return(ret);
}

/**
 * xmlRegexpExec:
 * @comp:  the compiled regular expression
 * @content:  the value to check against the regular expression
 *
 * Check if the regular expression generates the value
 *
 * Returns 1 if it matches, 0 if not and a negative value in case of error
 */
int
xmlRegexpExec(xmlRegexpPtr comp, const xmlChar *content) {
    if ((comp == NULL) || (content == NULL))
  return(-1);
    return(xmlFARegExec(comp, content));
}

/**
 * xmlRegexpIsDeterminist:
 * @comp:  the compiled regular expression
 *
 * Check if the regular expression is determinist
 *
 * Returns 1 if it yes, 0 if not and a negative value in case of error
 */
int
xmlRegexpIsDeterminist(xmlRegexpPtr comp) {
    xmlAutomataPtr am;
    int ret;

    if (comp == NULL)
  return(-1);
    if (comp->determinist != -1)
  return(comp->determinist);

    am = xmlNewAutomata();
    if (am == NULL)
        return(-1);
    if (am->states != NULL) {
  int i;

  for (i = 0;i < am->nbStates;i++)
      xmlRegFreeState(am->states[i]);
  xmlFree(am->states);
    }
    am->nbAtoms = comp->nbAtoms;
    am->atoms = comp->atoms;
    am->nbStates = comp->nbStates;
    am->states = comp->states;
    am->determinist = -1;
    am->flags = comp->flags;
    ret = xmlFAComputesDeterminism(am);
    am->atoms = NULL;
    am->states = NULL;
    xmlFreeAutomata(am);
    comp->determinist = ret;
    return(ret);
}

/**
 * xmlRegFreeRegexp:
 * @regexp:  the regexp
 *
 * Free a regexp
 */
void
xmlRegFreeRegexp(xmlRegexpPtr regexp) {
    int i;
    if (regexp == NULL)
  return;

    if (regexp->string != NULL)
  xmlFree(regexp->string);
    if (regexp->states != NULL) {
  for (i = 0;i < regexp->nbStates;i++)
      xmlRegFreeState(regexp->states[i]);
  xmlFree(regexp->states);
    }
    if (regexp->atoms != NULL) {
  for (i = 0;i < regexp->nbAtoms;i++)
      xmlRegFreeAtom(regexp->atoms[i]);
  xmlFree(regexp->atoms);
    }
    if (regexp->counters != NULL)
  xmlFree(regexp->counters);
    if (regexp->compact != NULL)
  xmlFree(regexp->compact);
    if (regexp->transdata != NULL)
  xmlFree(regexp->transdata);
    if (regexp->stringMap != NULL) {
  for (i = 0; i < regexp->nbstrings;i++)
      xmlFree(regexp->stringMap[i]);
  xmlFree(regexp->stringMap);
    }

    xmlFree(regexp);
}

#ifdef LIBXML_AUTOMATA_ENABLED
/************************************************************************
 *                  *
 *      The Automata interface        *
 *                  *
 ************************************************************************/

/**
 * xmlNewAutomata:
 *
 * Create a new automata
 *
 * Returns the new object or NULL in case of failure
 */
xmlAutomataPtr
xmlNewAutomata(void) {
    xmlAutomataPtr ctxt;

    ctxt = xmlRegNewParserCtxt(NULL);
    if (ctxt == NULL)
  return(NULL);

    /* initialize the parser */
    ctxt->state = xmlRegStatePush(ctxt);
    if (ctxt->state == NULL) {
  xmlFreeAutomata(ctxt);
  return(NULL);
    }
    ctxt->start = ctxt->state;
    ctxt->end = NULL;

    ctxt->start->type = XML_REGEXP_START_STATE;
    ctxt->flags = 0;

    return(ctxt);
}

/**
 * xmlFreeAutomata:
 * @am: an automata
 *
 * Free an automata
 */
void
xmlFreeAutomata(xmlAutomataPtr am) {
    if (am == NULL)
  return;
    xmlRegFreeParserCtxt(am);
}

/**
 * xmlAutomataSetFlags:
 * @am: an automata
 * @flags:  a set of internal flags
 *
 * Set some flags on the automata
 */
void
xmlAutomataSetFlags(xmlAutomataPtr am, int flags) {
    if (am == NULL)
  return;
    am->flags |= flags;
}

/**
 * xmlAutomataGetInitState:
 * @am: an automata
 *
 * Initial state lookup
 *
 * Returns the initial state of the automata
 */
xmlAutomataStatePtr
xmlAutomataGetInitState(xmlAutomataPtr am) {
    if (am == NULL)
  return(NULL);
    return(am->start);
}

/**
 * xmlAutomataSetFinalState:
 * @am: an automata
 * @state: a state in this automata
 *
 * Makes that state a final state
 *
 * Returns 0 or -1 in case of error
 */
int
xmlAutomataSetFinalState(xmlAutomataPtr am, xmlAutomataStatePtr state) {
    if ((am == NULL) || (state == NULL))
  return(-1);
    state->type = XML_REGEXP_FINAL_STATE;
    return(0);
}

/**
 * xmlAutomataNewTransition:
 * @am: an automata
 * @from: the starting point of the transition
 * @to: the target point of the transition or NULL
 * @token: the input string associated to that transition
 * @data: data passed to the callback function if the transition is activated
 *
 * If @to is NULL, this creates first a new target state in the automata
 * and then adds a transition from the @from state to the target state
 * activated by the value of @token
 *
 * Returns the target state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewTransition(xmlAutomataPtr am, xmlAutomataStatePtr from,
       xmlAutomataStatePtr to, const xmlChar *token,
       void *data) {
    xmlRegAtomPtr atom;

    if ((am == NULL) || (from == NULL) || (token == NULL))
  return(NULL);
    atom = xmlRegNewAtom(am, XML_REGEXP_STRING);
    if (atom == NULL)
        return(NULL);
    atom->data = data;
    atom->valuep = xmlStrdup(token);

    if (xmlFAGenerateTransitions(am, from, to, atom) < 0) {
        xmlRegFreeAtom(atom);
  return(NULL);
    }
    if (to == NULL)
  return(am->state);
    return(to);
}

/**
 * xmlAutomataNewTransition2:
 * @am: an automata
 * @from: the starting point of the transition
 * @to: the target point of the transition or NULL
 * @token: the first input string associated to that transition
 * @token2: the second input string associated to that transition
 * @data: data passed to the callback function if the transition is activated
 *
 * If @to is NULL, this creates first a new target state in the automata
 * and then adds a transition from the @from state to the target state
 * activated by the value of @token
 *
 * Returns the target state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewTransition2(xmlAutomataPtr am, xmlAutomataStatePtr from,
        xmlAutomataStatePtr to, const xmlChar *token,
        const xmlChar *token2, void *data) {
    xmlRegAtomPtr atom;

    if ((am == NULL) || (from == NULL) || (token == NULL))
  return(NULL);
    atom = xmlRegNewAtom(am, XML_REGEXP_STRING);
    if (atom == NULL)
  return(NULL);
    atom->data = data;
    if ((token2 == NULL) || (*token2 == 0)) {
  atom->valuep = xmlStrdup(token);
    } else {
  int lenn, lenp;
  xmlChar *str;

  lenn = strlen((char *) token2);
  lenp = strlen((char *) token);

  str = (xmlChar *) xmlMallocAtomic(lenn + lenp + 2);
  if (str == NULL) {
      xmlRegFreeAtom(atom);
      return(NULL);
  }
  memcpy(&str[0], token, lenp);
  str[lenp] = '|';
  memcpy(&str[lenp + 1], token2, lenn);
  str[lenn + lenp + 1] = 0;

  atom->valuep = str;
    }

    if (xmlFAGenerateTransitions(am, from, to, atom) < 0) {
        xmlRegFreeAtom(atom);
  return(NULL);
    }
    if (to == NULL)
  return(am->state);
    return(to);
}

/**
 * xmlAutomataNewNegTrans:
 * @am: an automata
 * @from: the starting point of the transition
 * @to: the target point of the transition or NULL
 * @token: the first input string associated to that transition
 * @token2: the second input string associated to that transition
 * @data: data passed to the callback function if the transition is activated
 *
 * If @to is NULL, this creates first a new target state in the automata
 * and then adds a transition from the @from state to the target state
 * activated by any value except (@token,@token2)
 * Note that if @token2 is not NULL, then (X, NULL) won't match to follow
 # the semantic of XSD ##other
 *
 * Returns the target state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewNegTrans(xmlAutomataPtr am, xmlAutomataStatePtr from,
           xmlAutomataStatePtr to, const xmlChar *token,
           const xmlChar *token2, void *data) {
    xmlRegAtomPtr atom;
    xmlChar err_msg[200];

    if ((am == NULL) || (from == NULL) || (token == NULL))
  return(NULL);
    atom = xmlRegNewAtom(am, XML_REGEXP_STRING);
    if (atom == NULL)
  return(NULL);
    atom->data = data;
    atom->neg = 1;
    if ((token2 == NULL) || (*token2 == 0)) {
  atom->valuep = xmlStrdup(token);
    } else {
  int lenn, lenp;
  xmlChar *str;

  lenn = strlen((char *) token2);
  lenp = strlen((char *) token);

  str = (xmlChar *) xmlMallocAtomic(lenn + lenp + 2);
  if (str == NULL) {
      xmlRegFreeAtom(atom);
      return(NULL);
  }
  memcpy(&str[0], token, lenp);
  str[lenp] = '|';
  memcpy(&str[lenp + 1], token2, lenn);
  str[lenn + lenp + 1] = 0;

  atom->valuep = str;
    }
    snprintf((char *) err_msg, 199, "not %s", (const char *) atom->valuep);
    err_msg[199] = 0;
    atom->valuep2 = xmlStrdup(err_msg);

    if (xmlFAGenerateTransitions(am, from, to, atom) < 0) {
        xmlRegFreeAtom(atom);
  return(NULL);
    }
    am->negs++;
    if (to == NULL)
  return(am->state);
    return(to);
}

/**
 * xmlAutomataNewCountTrans2:
 * @am: an automata
 * @from: the starting point of the transition
 * @to: the target point of the transition or NULL
 * @token: the input string associated to that transition
 * @token2: the second input string associated to that transition
 * @min:  the minimum successive occurrences of token
 * @max:  the maximum successive occurrences of token
 * @data:  data associated to the transition
 *
 * If @to is NULL, this creates first a new target state in the automata
 * and then adds a transition from the @from state to the target state
 * activated by a succession of input of value @token and @token2 and
 * whose number is between @min and @max
 *
 * Returns the target state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewCountTrans2(xmlAutomataPtr am, xmlAutomataStatePtr from,
       xmlAutomataStatePtr to, const xmlChar *token,
       const xmlChar *token2,
       int min, int max, void *data) {
    xmlRegAtomPtr atom;
    int counter;

    if ((am == NULL) || (from == NULL) || (token == NULL))
  return(NULL);
    if (min < 0)
  return(NULL);
    if ((max < min) || (max < 1))
  return(NULL);
    atom = xmlRegNewAtom(am, XML_REGEXP_STRING);
    if (atom == NULL)
  return(NULL);
    if ((token2 == NULL) || (*token2 == 0)) {
  atom->valuep = xmlStrdup(token);
        if (atom->valuep == NULL)
            goto error;
    } else {
  int lenn, lenp;
  xmlChar *str;

  lenn = strlen((char *) token2);
  lenp = strlen((char *) token);

  str = (xmlChar *) xmlMallocAtomic(lenn + lenp + 2);
  if (str == NULL)
      goto error;
  memcpy(&str[0], token, lenp);
  str[lenp] = '|';
  memcpy(&str[lenp + 1], token2, lenn);
  str[lenn + lenp + 1] = 0;

  atom->valuep = str;
    }
    atom->data = data;
    if (min == 0)
  atom->min = 1;
    else
  atom->min = min;
    atom->max = max;

    /*
     * associate a counter to the transition.
     */
    counter = xmlRegGetCounter(am);
    if (counter < 0)
        goto error;
    am->counters[counter].min = min;
    am->counters[counter].max = max;

    /* xmlFAGenerateTransitions(am, from, to, atom); */
    if (to == NULL) {
  to = xmlRegStatePush(am);
        if (to == NULL)
            goto error;
    }
    xmlRegStateAddTrans(am, from, atom, to, counter, -1);
    if (xmlRegAtomPush(am, atom) < 0)
        goto error;
    am->state = to;

    if (to == NULL)
  to = am->state;
    if (to == NULL)
  return(NULL);
    if (min == 0)
  xmlFAGenerateEpsilonTransition(am, from, to);
    return(to);

error:
    xmlRegFreeAtom(atom);
    return(NULL);
}

/**
 * xmlAutomataNewCountTrans:
 * @am: an automata
 * @from: the starting point of the transition
 * @to: the target point of the transition or NULL
 * @token: the input string associated to that transition
 * @min:  the minimum successive occurrences of token
 * @max:  the maximum successive occurrences of token
 * @data:  data associated to the transition
 *
 * If @to is NULL, this creates first a new target state in the automata
 * and then adds a transition from the @from state to the target state
 * activated by a succession of input of value @token and whose number
 * is between @min and @max
 *
 * Returns the target state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewCountTrans(xmlAutomataPtr am, xmlAutomataStatePtr from,
       xmlAutomataStatePtr to, const xmlChar *token,
       int min, int max, void *data) {
    xmlRegAtomPtr atom;
    int counter;

    if ((am == NULL) || (from == NULL) || (token == NULL))
  return(NULL);
    if (min < 0)
  return(NULL);
    if ((max < min) || (max < 1))
  return(NULL);
    atom = xmlRegNewAtom(am, XML_REGEXP_STRING);
    if (atom == NULL)
  return(NULL);
    atom->valuep = xmlStrdup(token);
    if (atom->valuep == NULL)
        goto error;
    atom->data = data;
    if (min == 0)
  atom->min = 1;
    else
  atom->min = min;
    atom->max = max;

    /*
     * associate a counter to the transition.
     */
    counter = xmlRegGetCounter(am);
    if (counter < 0)
        goto error;
    am->counters[counter].min = min;
    am->counters[counter].max = max;

    /* xmlFAGenerateTransitions(am, from, to, atom); */
    if (to == NULL) {
  to = xmlRegStatePush(am);
        if (to == NULL)
            goto error;
    }
    xmlRegStateAddTrans(am, from, atom, to, counter, -1);
    if (xmlRegAtomPush(am, atom) < 0)
        goto error;
    am->state = to;

    if (to == NULL)
  to = am->state;
    if (to == NULL)
  return(NULL);
    if (min == 0)
  xmlFAGenerateEpsilonTransition(am, from, to);
    return(to);

error:
    xmlRegFreeAtom(atom);
    return(NULL);
}

/**
 * xmlAutomataNewOnceTrans2:
 * @am: an automata
 * @from: the starting point of the transition
 * @to: the target point of the transition or NULL
 * @token: the input string associated to that transition
 * @token2: the second input string associated to that transition
 * @min:  the minimum successive occurrences of token
 * @max:  the maximum successive occurrences of token
 * @data:  data associated to the transition
 *
 * If @to is NULL, this creates first a new target state in the automata
 * and then adds a transition from the @from state to the target state
 * activated by a succession of input of value @token and @token2 and whose
 * number is between @min and @max, moreover that transition can only be
 * crossed once.
 *
 * Returns the target state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewOnceTrans2(xmlAutomataPtr am, xmlAutomataStatePtr from,
       xmlAutomataStatePtr to, const xmlChar *token,
       const xmlChar *token2,
       int min, int max, void *data) {
    xmlRegAtomPtr atom;
    int counter;

    if ((am == NULL) || (from == NULL) || (token == NULL))
  return(NULL);
    if (min < 1)
  return(NULL);
    if (max < min)
  return(NULL);
    atom = xmlRegNewAtom(am, XML_REGEXP_STRING);
    if (atom == NULL)
  return(NULL);
    if ((token2 == NULL) || (*token2 == 0)) {
  atom->valuep = xmlStrdup(token);
        if (atom->valuep == NULL)
            goto error;
    } else {
  int lenn, lenp;
  xmlChar *str;

  lenn = strlen((char *) token2);
  lenp = strlen((char *) token);

  str = (xmlChar *) xmlMallocAtomic(lenn + lenp + 2);
  if (str == NULL)
      goto error;
  memcpy(&str[0], token, lenp);
  str[lenp] = '|';
  memcpy(&str[lenp + 1], token2, lenn);
  str[lenn + lenp + 1] = 0;

  atom->valuep = str;
    }
    atom->data = data;
    atom->quant = XML_REGEXP_QUANT_ONCEONLY;
    atom->min = min;
    atom->max = max;
    /*
     * associate a counter to the transition.
     */
    counter = xmlRegGetCounter(am);
    if (counter < 0)
        goto error;
    am->counters[counter].min = 1;
    am->counters[counter].max = 1;

    /* xmlFAGenerateTransitions(am, from, to, atom); */
    if (to == NULL) {
  to = xmlRegStatePush(am);
        if (to == NULL)
            goto error;
    }
    xmlRegStateAddTrans(am, from, atom, to, counter, -1);
    if (xmlRegAtomPush(am, atom) < 0)
        goto error;
    am->state = to;
    return(to);

error:
    xmlRegFreeAtom(atom);
    return(NULL);
}



/**
 * xmlAutomataNewOnceTrans:
 * @am: an automata
 * @from: the starting point of the transition
 * @to: the target point of the transition or NULL
 * @token: the input string associated to that transition
 * @min:  the minimum successive occurrences of token
 * @max:  the maximum successive occurrences of token
 * @data:  data associated to the transition
 *
 * If @to is NULL, this creates first a new target state in the automata
 * and then adds a transition from the @from state to the target state
 * activated by a succession of input of value @token and whose number
 * is between @min and @max, moreover that transition can only be crossed
 * once.
 *
 * Returns the target state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewOnceTrans(xmlAutomataPtr am, xmlAutomataStatePtr from,
       xmlAutomataStatePtr to, const xmlChar *token,
       int min, int max, void *data) {
    xmlRegAtomPtr atom;
    int counter;

    if ((am == NULL) || (from == NULL) || (token == NULL))
  return(NULL);
    if (min < 1)
  return(NULL);
    if (max < min)
  return(NULL);
    atom = xmlRegNewAtom(am, XML_REGEXP_STRING);
    if (atom == NULL)
  return(NULL);
    atom->valuep = xmlStrdup(token);
    atom->data = data;
    atom->quant = XML_REGEXP_QUANT_ONCEONLY;
    atom->min = min;
    atom->max = max;
    /*
     * associate a counter to the transition.
     */
    counter = xmlRegGetCounter(am);
    if (counter < 0)
        goto error;
    am->counters[counter].min = 1;
    am->counters[counter].max = 1;

    /* xmlFAGenerateTransitions(am, from, to, atom); */
    if (to == NULL) {
  to = xmlRegStatePush(am);
        if (to == NULL)
            goto error;
    }
    xmlRegStateAddTrans(am, from, atom, to, counter, -1);
    if (xmlRegAtomPush(am, atom) < 0)
        goto error;
    am->state = to;
    return(to);

error:
    xmlRegFreeAtom(atom);
    return(NULL);
}

/**
 * xmlAutomataNewState:
 * @am: an automata
 *
 * Create a new disconnected state in the automata
 *
 * Returns the new state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewState(xmlAutomataPtr am) {
    if (am == NULL)
  return(NULL);
    return(xmlRegStatePush(am));
}

/**
 * xmlAutomataNewEpsilon:
 * @am: an automata
 * @from: the starting point of the transition
 * @to: the target point of the transition or NULL
 *
 * If @to is NULL, this creates first a new target state in the automata
 * and then adds an epsilon transition from the @from state to the
 * target state
 *
 * Returns the target state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewEpsilon(xmlAutomataPtr am, xmlAutomataStatePtr from,
          xmlAutomataStatePtr to) {
    if ((am == NULL) || (from == NULL))
  return(NULL);
    xmlFAGenerateEpsilonTransition(am, from, to);
    if (to == NULL)
  return(am->state);
    return(to);
}

/**
 * xmlAutomataNewAllTrans:
 * @am: an automata
 * @from: the starting point of the transition
 * @to: the target point of the transition or NULL
 * @lax: allow to transition if not all all transitions have been activated
 *
 * If @to is NULL, this creates first a new target state in the automata
 * and then adds a an ALL transition from the @from state to the
 * target state. That transition is an epsilon transition allowed only when
 * all transitions from the @from node have been activated.
 *
 * Returns the target state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewAllTrans(xmlAutomataPtr am, xmlAutomataStatePtr from,
           xmlAutomataStatePtr to, int lax) {
    if ((am == NULL) || (from == NULL))
  return(NULL);
    xmlFAGenerateAllTransition(am, from, to, lax);
    if (to == NULL)
  return(am->state);
    return(to);
}

/**
 * xmlAutomataNewCounter:
 * @am: an automata
 * @min:  the minimal value on the counter
 * @max:  the maximal value on the counter
 *
 * Create a new counter
 *
 * Returns the counter number or -1 in case of error
 */
int
xmlAutomataNewCounter(xmlAutomataPtr am, int min, int max) {
    int ret;

    if (am == NULL)
  return(-1);

    ret = xmlRegGetCounter(am);
    if (ret < 0)
  return(-1);
    am->counters[ret].min = min;
    am->counters[ret].max = max;
    return(ret);
}

/**
 * xmlAutomataNewCountedTrans:
 * @am: an automata
 * @from: the starting point of the transition
 * @to: the target point of the transition or NULL
 * @counter: the counter associated to that transition
 *
 * If @to is NULL, this creates first a new target state in the automata
 * and then adds an epsilon transition from the @from state to the target state
 * which will increment the counter provided
 *
 * Returns the target state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewCountedTrans(xmlAutomataPtr am, xmlAutomataStatePtr from,
    xmlAutomataStatePtr to, int counter) {
    if ((am == NULL) || (from == NULL) || (counter < 0))
  return(NULL);
    xmlFAGenerateCountedEpsilonTransition(am, from, to, counter);
    if (to == NULL)
  return(am->state);
    return(to);
}

/**
 * xmlAutomataNewCounterTrans:
 * @am: an automata
 * @from: the starting point of the transition
 * @to: the target point of the transition or NULL
 * @counter: the counter associated to that transition
 *
 * If @to is NULL, this creates first a new target state in the automata
 * and then adds an epsilon transition from the @from state to the target state
 * which will be allowed only if the counter is within the right range.
 *
 * Returns the target state or NULL in case of error
 */
xmlAutomataStatePtr
xmlAutomataNewCounterTrans(xmlAutomataPtr am, xmlAutomataStatePtr from,
    xmlAutomataStatePtr to, int counter) {
    if ((am == NULL) || (from == NULL) || (counter < 0))
  return(NULL);
    xmlFAGenerateCountedTransition(am, from, to, counter);
    if (to == NULL)
  return(am->state);
    return(to);
}

/**
 * xmlAutomataCompile:
 * @am: an automata
 *
 * Compile the automata into a Reg Exp ready for being executed.
 * The automata should be free after this point.
 *
 * Returns the compiled regexp or NULL in case of error
 */
xmlRegexpPtr
xmlAutomataCompile(xmlAutomataPtr am) {
    xmlRegexpPtr ret;

    if ((am == NULL) || (am->error != 0)) return(NULL);
    xmlFAEliminateEpsilonTransitions(am);
    /* xmlFAComputesDeterminism(am); */
    ret = xmlRegEpxFromParse(am);

    return(ret);
}

/**
 * xmlAutomataIsDeterminist:
 * @am: an automata
 *
 * Checks if an automata is determinist.
 *
 * Returns 1 if true, 0 if not, and -1 in case of error
 */
int
xmlAutomataIsDeterminist(xmlAutomataPtr am) {
    int ret;

    if (am == NULL)
  return(-1);

    ret = xmlFAComputesDeterminism(am);
    return(ret);
}
#endif /* LIBXML_AUTOMATA_ENABLED */

#ifdef LIBXML_EXPR_ENABLED
/************************************************************************
 *                  *
 *    Formal Expression handling code       *
 *                  *
 ************************************************************************/
/************************************************************************
 *                  *
 *    Expression handling context       *
 *                  *
 ************************************************************************/

struct _xmlExpCtxt {
    xmlDictPtr dict;
    xmlExpNodePtr *table;
    int size;
    int nbElems;
    int nb_nodes;
    int maxNodes;
    const char *expr;
    const char *cur;
    int nb_cons;
    int tabSize;
};

/**
 * xmlExpNewCtxt:
 * @maxNodes:  the maximum number of nodes
 * @dict:  optional dictionary to use internally
 *
 * Creates a new context for manipulating expressions
 *
 * Returns the context or NULL in case of error
 */
xmlExpCtxtPtr
xmlExpNewCtxt(int maxNodes, xmlDictPtr dict) {
    xmlExpCtxtPtr ret;
    int size = 256;

    if (maxNodes <= 4096)
        maxNodes = 4096;

    ret = (xmlExpCtxtPtr) xmlMalloc(sizeof(xmlExpCtxt));
    if (ret == NULL)
        return(NULL);
    memset(ret, 0, sizeof(xmlExpCtxt));
    ret->size = size;
    ret->nbElems = 0;
    ret->maxNodes = maxNodes;
    ret->table = xmlMalloc(size * sizeof(xmlExpNodePtr));
    if (ret->table == NULL) {
        xmlFree(ret);
  return(NULL);
    }
    memset(ret->table, 0, size * sizeof(xmlExpNodePtr));
    if (dict == NULL) {
        ret->dict = xmlDictCreate();
  if (ret->dict == NULL) {
      xmlFree(ret->table);
      xmlFree(ret);
      return(NULL);
  }
    } else {
        ret->dict = dict;
  xmlDictReference(ret->dict);
    }
    return(ret);
}

/**
 * xmlExpFreeCtxt:
 * @ctxt:  an expression context
 *
 * Free an expression context
 */
void
xmlExpFreeCtxt(xmlExpCtxtPtr ctxt) {
    if (ctxt == NULL)
        return;
    xmlDictFree(ctxt->dict);
    if (ctxt->table != NULL)
  xmlFree(ctxt->table);
    xmlFree(ctxt);
}

/************************************************************************
 *                  *
 *    Structure associated to an expression node    *
 *                  *
 ************************************************************************/
#define MAX_NODES 10000

/* #define DEBUG_DERIV */

/*
 * TODO:
 * - Wildcards
 * - public API for creation
 *
 * Started
 * - regression testing
 *
 * Done
 * - split into module and test tool
 * - memleaks
 */

typedef enum {
    XML_EXP_NILABLE = (1 << 0)
} xmlExpNodeInfo;

#define IS_NILLABLE(node) ((node)->info & XML_EXP_NILABLE)

struct _xmlExpNode {
    unsigned char type;/* xmlExpNodeType */
    unsigned char info;/* OR of xmlExpNodeInfo */
    unsigned short key; /* the hash key */
    unsigned int ref; /* The number of references */
    int c_max;    /* the maximum length it can consume */
    xmlExpNodePtr exp_left;
    xmlExpNodePtr next;/* the next node in the hash table or free list */
    union {
  struct {
      int f_min;
      int f_max;
  } count;
  struct {
      xmlExpNodePtr f_right;
  } children;
        const xmlChar *f_str;
    } field;
};

#define exp_min field.count.f_min
#define exp_max field.count.f_max
/* #define exp_left field.children.f_left */
#define exp_right field.children.f_right
#define exp_str field.f_str

static xmlExpNodePtr xmlExpNewNode(xmlExpCtxtPtr ctxt, xmlExpNodeType type);
static xmlExpNode forbiddenExpNode = {
    XML_EXP_FORBID, 0, 0, 0, 0, NULL, NULL, {{ 0, 0}}
};
xmlExpNodePtr forbiddenExp = &forbiddenExpNode;
static xmlExpNode emptyExpNode = {
    XML_EXP_EMPTY, 1, 0, 0, 0, NULL, NULL, {{ 0, 0}}
};
xmlExpNodePtr emptyExp = &emptyExpNode;

/************************************************************************
 *                  *
 *  The custom hash table for unicity and canonicalization    *
 *  of sub-expressions pointers           *
 *                  *
 ************************************************************************/
/*
 * xmlExpHashNameComputeKey:
 * Calculate the hash key for a token
 */
static unsigned short
xmlExpHashNameComputeKey(const xmlChar *name) {
    unsigned short value = 0L;
    char ch;

    if (name != NULL) {
  value += 30 * (*name);
  while ((ch = *name++) != 0) {
      value = value ^ ((value << 5) + (value >> 3) + (unsigned long)ch);
  }
    }
    return (value);
}

/*
 * xmlExpHashComputeKey:
 * Calculate the hash key for a compound expression
 */
static unsigned short
xmlExpHashComputeKey(xmlExpNodeType type, xmlExpNodePtr left,
                     xmlExpNodePtr right) {
    unsigned long value;
    unsigned short ret;

    switch (type) {
        case XML_EXP_SEQ:
      value = left->key;
      value += right->key;
      value *= 3;
      ret = (unsigned short) value;
      break;
        case XML_EXP_OR:
      value = left->key;
      value += right->key;
      value *= 7;
      ret = (unsigned short) value;
      break;
        case XML_EXP_COUNT:
      value = left->key;
      value += right->key;
      ret = (unsigned short) value;
      break;
  default:
      ret = 0;
    }
    return(ret);
}


static xmlExpNodePtr
xmlExpNewNode(xmlExpCtxtPtr ctxt, xmlExpNodeType type) {
    xmlExpNodePtr ret;

    if (ctxt->nb_nodes >= MAX_NODES)
        return(NULL);
    ret = (xmlExpNodePtr) xmlMalloc(sizeof(xmlExpNode));
    if (ret == NULL)
        return(NULL);
    memset(ret, 0, sizeof(xmlExpNode));
    ret->type = type;
    ret->next = NULL;
    ctxt->nb_nodes++;
    ctxt->nb_cons++;
    return(ret);
}

/**
 * xmlExpHashGetEntry:
 * @table: the hash table
 *
 * Get the unique entry from the hash table. The entry is created if
 * needed. @left and @right are consumed, i.e. their ref count will
 * be decremented by the operation.
 *
 * Returns the pointer or NULL in case of error
 */
static xmlExpNodePtr
xmlExpHashGetEntry(xmlExpCtxtPtr ctxt, xmlExpNodeType type,
                   xmlExpNodePtr left, xmlExpNodePtr right,
       const xmlChar *name, int min, int max) {
    unsigned short kbase, key;
    xmlExpNodePtr entry;
    xmlExpNodePtr insert;

    if (ctxt == NULL)
  return(NULL);

    /*
     * Check for duplicate and insertion location.
     */
    if (type == XML_EXP_ATOM) {
  kbase = xmlExpHashNameComputeKey(name);
    } else if (type == XML_EXP_COUNT) {
        /* COUNT reduction rule 1 */
  /* a{1} -> a */
  if (min == max) {
      if (min == 1) {
    return(left);
      }
      if (min == 0) {
    xmlExpFree(ctxt, left);
          return(emptyExp);
      }
  }
  if (min < 0) {
      xmlExpFree(ctxt, left);
      return(forbiddenExp);
  }
        if (max == -1)
      kbase = min + 79;
  else
      kbase = max - min;
  kbase += left->key;
    } else if (type == XML_EXP_OR) {
        /* Forbid reduction rules */
        if (left->type == XML_EXP_FORBID) {
      xmlExpFree(ctxt, left);
      return(right);
  }
        if (right->type == XML_EXP_FORBID) {
      xmlExpFree(ctxt, right);
      return(left);
  }

        /* OR reduction rule 1 */
  /* a | a reduced to a */
        if (left == right) {
      xmlExpFree(ctxt, right);
      return(left);
  }
        /* OR canonicalization rule 1 */
  /* linearize (a | b) | c into a | (b | c) */
        if ((left->type == XML_EXP_OR) && (right->type != XML_EXP_OR)) {
      xmlExpNodePtr tmp = left;
            left = right;
      right = tmp;
  }
        /* OR reduction rule 2 */
  /* a | (a | b) and b | (a | b) are reduced to a | b */
        if (right->type == XML_EXP_OR) {
      if ((left == right->exp_left) ||
          (left == right->exp_right)) {
    xmlExpFree(ctxt, left);
    return(right);
      }
  }
        /* OR canonicalization rule 2 */
  /* linearize (a | b) | c into a | (b | c) */
        if (left->type == XML_EXP_OR) {
      xmlExpNodePtr tmp;

      /* OR canonicalization rule 2 */
      if ((left->exp_right->type != XML_EXP_OR) &&
          (left->exp_right->key < left->exp_left->key)) {
          tmp = left->exp_right;
    left->exp_right = left->exp_left;
    left->exp_left = tmp;
      }
      left->exp_right->ref++;
      tmp = xmlExpHashGetEntry(ctxt, XML_EXP_OR, left->exp_right, right,
                               NULL, 0, 0);
      left->exp_left->ref++;
      tmp = xmlExpHashGetEntry(ctxt, XML_EXP_OR, left->exp_left, tmp,
                               NULL, 0, 0);

      xmlExpFree(ctxt, left);
      return(tmp);
  }
  if (right->type == XML_EXP_OR) {
      /* Ordering in the tree */
      /* C | (A | B) -> A | (B | C) */
      if (left->key > right->exp_right->key) {
    xmlExpNodePtr tmp;
    right->exp_right->ref++;
    tmp = xmlExpHashGetEntry(ctxt, XML_EXP_OR, right->exp_right,
                             left, NULL, 0, 0);
    right->exp_left->ref++;
    tmp = xmlExpHashGetEntry(ctxt, XML_EXP_OR, right->exp_left,
                             tmp, NULL, 0, 0);
    xmlExpFree(ctxt, right);
    return(tmp);
      }
      /* Ordering in the tree */
      /* B | (A | C) -> A | (B | C) */
      if (left->key > right->exp_left->key) {
    xmlExpNodePtr tmp;
    right->exp_right->ref++;
    tmp = xmlExpHashGetEntry(ctxt, XML_EXP_OR, left,
                             right->exp_right, NULL, 0, 0);
    right->exp_left->ref++;
    tmp = xmlExpHashGetEntry(ctxt, XML_EXP_OR, right->exp_left,
                             tmp, NULL, 0, 0);
    xmlExpFree(ctxt, right);
    return(tmp);
      }
  }
  /* we know both types are != XML_EXP_OR here */
        else if (left->key > right->key) {
      xmlExpNodePtr tmp = left;
            left = right;
      right = tmp;
  }
  kbase = xmlExpHashComputeKey(type, left, right);
    } else if (type == XML_EXP_SEQ) {
        /* Forbid reduction rules */
        if (left->type == XML_EXP_FORBID) {
      xmlExpFree(ctxt, right);
      return(left);
  }
        if (right->type == XML_EXP_FORBID) {
      xmlExpFree(ctxt, left);
      return(right);
  }
        /* Empty reduction rules */
        if (right->type == XML_EXP_EMPTY) {
      return(left);
  }
        if (left->type == XML_EXP_EMPTY) {
      return(right);
  }
  kbase = xmlExpHashComputeKey(type, left, right);
    } else
        return(NULL);

    key = kbase % ctxt->size;
    if (ctxt->table[key] != NULL) {
  for (insert = ctxt->table[key]; insert != NULL;
       insert = insert->next) {
      if ((insert->key == kbase) &&
          (insert->type == type)) {
    if (type == XML_EXP_ATOM) {
        if (name == insert->exp_str) {
      insert->ref++;
      return(insert);
        }
    } else if (type == XML_EXP_COUNT) {
        if ((insert->exp_min == min) && (insert->exp_max == max) &&
            (insert->exp_left == left)) {
      insert->ref++;
      left->ref--;
      return(insert);
        }
    } else if ((insert->exp_left == left) &&
         (insert->exp_right == right)) {
        insert->ref++;
        left->ref--;
        right->ref--;
        return(insert);
    }
      }
  }
    }

    entry = xmlExpNewNode(ctxt, type);
    if (entry == NULL)
        return(NULL);
    entry->key = kbase;
    if (type == XML_EXP_ATOM) {
  entry->exp_str = name;
  entry->c_max = 1;
    } else if (type == XML_EXP_COUNT) {
        entry->exp_min = min;
        entry->exp_max = max;
  entry->exp_left = left;
  if ((min == 0) || (IS_NILLABLE(left)))
      entry->info |= XML_EXP_NILABLE;
  if (max < 0)
      entry->c_max = -1;
  else
      entry->c_max = max * entry->exp_left->c_max;
    } else {
  entry->exp_left = left;
  entry->exp_right = right;
  if (type == XML_EXP_OR) {
      if ((IS_NILLABLE(left)) || (IS_NILLABLE(right)))
    entry->info |= XML_EXP_NILABLE;
      if ((entry->exp_left->c_max == -1) ||
          (entry->exp_right->c_max == -1))
    entry->c_max = -1;
      else if (entry->exp_left->c_max > entry->exp_right->c_max)
          entry->c_max = entry->exp_left->c_max;
      else
          entry->c_max = entry->exp_right->c_max;
  } else {
      if ((IS_NILLABLE(left)) && (IS_NILLABLE(right)))
    entry->info |= XML_EXP_NILABLE;
      if ((entry->exp_left->c_max == -1) ||
          (entry->exp_right->c_max == -1))
    entry->c_max = -1;
      else
          entry->c_max = entry->exp_left->c_max + entry->exp_right->c_max;
  }
    }
    entry->ref = 1;
    if (ctxt->table[key] != NULL)
        entry->next = ctxt->table[key];

    ctxt->table[key] = entry;
    ctxt->nbElems++;

    return(entry);
}

/**
 * xmlExpFree:
 * @ctxt: the expression context
 * @exp: the expression
 *
 * Dereference the expression
 */
void
xmlExpFree(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp) {
    if ((exp == NULL) || (exp == forbiddenExp) || (exp == emptyExp))
        return;
    exp->ref--;
    if (exp->ref == 0) {
        unsigned short key;

        /* Unlink it first from the hash table */
  key = exp->key % ctxt->size;
  if (ctxt->table[key] == exp) {
      ctxt->table[key] = exp->next;
  } else {
      xmlExpNodePtr tmp;

      tmp = ctxt->table[key];
      while (tmp != NULL) {
          if (tmp->next == exp) {
        tmp->next = exp->next;
        break;
    }
          tmp = tmp->next;
      }
  }

        if ((exp->type == XML_EXP_SEQ) || (exp->type == XML_EXP_OR)) {
      xmlExpFree(ctxt, exp->exp_left);
      xmlExpFree(ctxt, exp->exp_right);
  } else if (exp->type == XML_EXP_COUNT) {
      xmlExpFree(ctxt, exp->exp_left);
  }
        xmlFree(exp);
  ctxt->nb_nodes--;
    }
}

/**
 * xmlExpRef:
 * @exp: the expression
 *
 * Increase the reference count of the expression
 */
void
xmlExpRef(xmlExpNodePtr exp) {
    if (exp != NULL)
        exp->ref++;
}

/**
 * xmlExpNewAtom:
 * @ctxt: the expression context
 * @name: the atom name
 * @len: the atom name length in byte (or -1);
 *
 * Get the atom associated to this name from that context
 *
 * Returns the node or NULL in case of error
 */
xmlExpNodePtr
xmlExpNewAtom(xmlExpCtxtPtr ctxt, const xmlChar *name, int len) {
    if ((ctxt == NULL) || (name == NULL))
        return(NULL);
    name = xmlDictLookup(ctxt->dict, name, len);
    if (name == NULL)
        return(NULL);
    return(xmlExpHashGetEntry(ctxt, XML_EXP_ATOM, NULL, NULL, name, 0, 0));
}

/**
 * xmlExpNewOr:
 * @ctxt: the expression context
 * @left: left expression
 * @right: right expression
 *
 * Get the atom associated to the choice @left | @right
 * Note that @left and @right are consumed in the operation, to keep
 * an handle on them use xmlExpRef() and use xmlExpFree() to release them,
 * this is true even in case of failure (unless ctxt == NULL).
 *
 * Returns the node or NULL in case of error
 */
xmlExpNodePtr
xmlExpNewOr(xmlExpCtxtPtr ctxt, xmlExpNodePtr left, xmlExpNodePtr right) {
    if (ctxt == NULL)
        return(NULL);
    if ((left == NULL) || (right == NULL)) {
        xmlExpFree(ctxt, left);
        xmlExpFree(ctxt, right);
        return(NULL);
    }
    return(xmlExpHashGetEntry(ctxt, XML_EXP_OR, left, right, NULL, 0, 0));
}

/**
 * xmlExpNewSeq:
 * @ctxt: the expression context
 * @left: left expression
 * @right: right expression
 *
 * Get the atom associated to the sequence @left , @right
 * Note that @left and @right are consumed in the operation, to keep
 * an handle on them use xmlExpRef() and use xmlExpFree() to release them,
 * this is true even in case of failure (unless ctxt == NULL).
 *
 * Returns the node or NULL in case of error
 */
xmlExpNodePtr
xmlExpNewSeq(xmlExpCtxtPtr ctxt, xmlExpNodePtr left, xmlExpNodePtr right) {
    if (ctxt == NULL)
        return(NULL);
    if ((left == NULL) || (right == NULL)) {
        xmlExpFree(ctxt, left);
        xmlExpFree(ctxt, right);
        return(NULL);
    }
    return(xmlExpHashGetEntry(ctxt, XML_EXP_SEQ, left, right, NULL, 0, 0));
}

/**
 * xmlExpNewRange:
 * @ctxt: the expression context
 * @subset: the expression to be repeated
 * @min: the lower bound for the repetition
 * @max: the upper bound for the repetition, -1 means infinite
 *
 * Get the atom associated to the range (@subset){@min, @max}
 * Note that @subset is consumed in the operation, to keep
 * an handle on it use xmlExpRef() and use xmlExpFree() to release it,
 * this is true even in case of failure (unless ctxt == NULL).
 *
 * Returns the node or NULL in case of error
 */
xmlExpNodePtr
xmlExpNewRange(xmlExpCtxtPtr ctxt, xmlExpNodePtr subset, int min, int max) {
    if (ctxt == NULL)
        return(NULL);
    if ((subset == NULL) || (min < 0) || (max < -1) ||
        ((max >= 0) && (min > max))) {
  xmlExpFree(ctxt, subset);
        return(NULL);
    }
    return(xmlExpHashGetEntry(ctxt, XML_EXP_COUNT, subset,
                              NULL, NULL, min, max));
}

/************************************************************************
 *                  *
 *    Public API for operations on expressions    *
 *                  *
 ************************************************************************/

static int
xmlExpGetLanguageInt(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp,
                     const xmlChar**list, int len, int nb) {
    int tmp, tmp2;
tail:
    switch (exp->type) {
        case XML_EXP_EMPTY:
      return(0);
        case XML_EXP_ATOM:
      for (tmp = 0;tmp < nb;tmp++)
          if (list[tmp] == exp->exp_str)
        return(0);
            if (nb >= len)
          return(-2);
      list[nb] = exp->exp_str;
      return(1);
        case XML_EXP_COUNT:
      exp = exp->exp_left;
      goto tail;
        case XML_EXP_SEQ:
        case XML_EXP_OR:
      tmp = xmlExpGetLanguageInt(ctxt, exp->exp_left, list, len, nb);
      if (tmp < 0)
          return(tmp);
      tmp2 = xmlExpGetLanguageInt(ctxt, exp->exp_right, list, len,
                                  nb + tmp);
      if (tmp2 < 0)
          return(tmp2);
            return(tmp + tmp2);
    }
    return(-1);
}

/**
 * xmlExpGetLanguage:
 * @ctxt: the expression context
 * @exp: the expression
 * @langList: where to store the tokens
 * @len: the allocated length of @list
 *
 * Find all the strings used in @exp and store them in @list
 *
 * Returns the number of unique strings found, -1 in case of errors and
 *         -2 if there is more than @len strings
 */
int
xmlExpGetLanguage(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp,
                  const xmlChar**langList, int len) {
    if ((ctxt == NULL) || (exp == NULL) || (langList == NULL) || (len <= 0))
        return(-1);
    return(xmlExpGetLanguageInt(ctxt, exp, langList, len, 0));
}

static int
xmlExpGetStartInt(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp,
                  const xmlChar**list, int len, int nb) {
    int tmp, tmp2;
tail:
    switch (exp->type) {
        case XML_EXP_FORBID:
      return(0);
        case XML_EXP_EMPTY:
      return(0);
        case XML_EXP_ATOM:
      for (tmp = 0;tmp < nb;tmp++)
          if (list[tmp] == exp->exp_str)
        return(0);
            if (nb >= len)
          return(-2);
      list[nb] = exp->exp_str;
      return(1);
        case XML_EXP_COUNT:
      exp = exp->exp_left;
      goto tail;
        case XML_EXP_SEQ:
      tmp = xmlExpGetStartInt(ctxt, exp->exp_left, list, len, nb);
      if (tmp < 0)
          return(tmp);
      if (IS_NILLABLE(exp->exp_left)) {
    tmp2 = xmlExpGetStartInt(ctxt, exp->exp_right, list, len,
              nb + tmp);
    if (tmp2 < 0)
        return(tmp2);
    tmp += tmp2;
      }
            return(tmp);
        case XML_EXP_OR:
      tmp = xmlExpGetStartInt(ctxt, exp->exp_left, list, len, nb);
      if (tmp < 0)
          return(tmp);
      tmp2 = xmlExpGetStartInt(ctxt, exp->exp_right, list, len,
                                  nb + tmp);
      if (tmp2 < 0)
          return(tmp2);
            return(tmp + tmp2);
    }
    return(-1);
}

/**
 * xmlExpGetStart:
 * @ctxt: the expression context
 * @exp: the expression
 * @tokList: where to store the tokens
 * @len: the allocated length of @list
 *
 * Find all the strings that appears at the start of the languages
 * accepted by @exp and store them in @list. E.g. for (a, b) | c
 * it will return the list [a, c]
 *
 * Returns the number of unique strings found, -1 in case of errors and
 *         -2 if there is more than @len strings
 */
int
xmlExpGetStart(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp,
               const xmlChar**tokList, int len) {
    if ((ctxt == NULL) || (exp == NULL) || (tokList == NULL) || (len <= 0))
        return(-1);
    return(xmlExpGetStartInt(ctxt, exp, tokList, len, 0));
}

/**
 * xmlExpIsNillable:
 * @exp: the expression
 *
 * Finds if the expression is nillable, i.e. if it accepts the empty sequence
 *
 * Returns 1 if nillable, 0 if not and -1 in case of error
 */
int
xmlExpIsNillable(xmlExpNodePtr exp) {
    if (exp == NULL)
        return(-1);
    return(IS_NILLABLE(exp) != 0);
}

static xmlExpNodePtr
xmlExpStringDeriveInt(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp, const xmlChar *str)
{
    xmlExpNodePtr ret;

    switch (exp->type) {
  case XML_EXP_EMPTY:
      return(forbiddenExp);
  case XML_EXP_FORBID:
      return(forbiddenExp);
  case XML_EXP_ATOM:
      if (exp->exp_str == str) {
#ifdef DEBUG_DERIV
    printf("deriv atom: equal => Empty\n");
#endif
          ret = emptyExp;
      } else {
#ifdef DEBUG_DERIV
    printf("deriv atom: mismatch => forbid\n");
#endif
          /* TODO wildcards here */
    ret = forbiddenExp;
      }
      return(ret);
  case XML_EXP_OR: {
      xmlExpNodePtr tmp;

#ifdef DEBUG_DERIV
      printf("deriv or: => or(derivs)\n");
#endif
      tmp = xmlExpStringDeriveInt(ctxt, exp->exp_left, str);
      if (tmp == NULL) {
    return(NULL);
      }
      ret = xmlExpStringDeriveInt(ctxt, exp->exp_right, str);
      if (ret == NULL) {
          xmlExpFree(ctxt, tmp);
    return(NULL);
      }
            ret = xmlExpHashGetEntry(ctxt, XML_EXP_OR, tmp, ret,
           NULL, 0, 0);
      return(ret);
  }
  case XML_EXP_SEQ:
#ifdef DEBUG_DERIV
      printf("deriv seq: starting with left\n");
#endif
      ret = xmlExpStringDeriveInt(ctxt, exp->exp_left, str);
      if (ret == NULL) {
          return(NULL);
      } else if (ret == forbiddenExp) {
          if (IS_NILLABLE(exp->exp_left)) {
#ifdef DEBUG_DERIV
        printf("deriv seq: left failed but nillable\n");
#endif
        ret = xmlExpStringDeriveInt(ctxt, exp->exp_right, str);
    }
      } else {
#ifdef DEBUG_DERIV
    printf("deriv seq: left match => sequence\n");
#endif
          exp->exp_right->ref++;
          ret = xmlExpHashGetEntry(ctxt, XML_EXP_SEQ, ret, exp->exp_right,
                             NULL, 0, 0);
      }
      return(ret);
  case XML_EXP_COUNT: {
      int min, max;
      xmlExpNodePtr tmp;

      if (exp->exp_max == 0)
    return(forbiddenExp);
      ret = xmlExpStringDeriveInt(ctxt, exp->exp_left, str);
      if (ret == NULL)
          return(NULL);
      if (ret == forbiddenExp) {
#ifdef DEBUG_DERIV
    printf("deriv count: pattern mismatch => forbid\n");
#endif
          return(ret);
      }
      if (exp->exp_max == 1)
    return(ret);
      if (exp->exp_max < 0) /* unbounded */
    max = -1;
      else
    max = exp->exp_max - 1;
      if (exp->exp_min > 0)
    min = exp->exp_min - 1;
      else
    min = 0;
      exp->exp_left->ref++;
      tmp = xmlExpHashGetEntry(ctxt, XML_EXP_COUNT, exp->exp_left, NULL,
             NULL, min, max);
      if (ret == emptyExp) {
#ifdef DEBUG_DERIV
    printf("deriv count: match to empty => new count\n");
#endif
          return(tmp);
      }
#ifdef DEBUG_DERIV
      printf("deriv count: match => sequence with new count\n");
#endif
      return(xmlExpHashGetEntry(ctxt, XML_EXP_SEQ, ret, tmp,
                                NULL, 0, 0));
  }
    }
    return(NULL);
}

/**
 * xmlExpStringDerive:
 * @ctxt: the expression context
 * @exp: the expression
 * @str: the string
 * @len: the string len in bytes if available
 *
 * Do one step of Brzozowski derivation of the expression @exp with
 * respect to the input string
 *
 * Returns the resulting expression or NULL in case of internal error
 */
xmlExpNodePtr
xmlExpStringDerive(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp,
                   const xmlChar *str, int len) {
    const xmlChar *input;

    if ((exp == NULL) || (ctxt == NULL) || (str == NULL)) {
        return(NULL);
    }
    /*
     * check the string is in the dictionary, if yes use an interned
     * copy, otherwise we know it's not an acceptable input
     */
    input = xmlDictExists(ctxt->dict, str, len);
    if (input == NULL) {
        return(forbiddenExp);
    }
    return(xmlExpStringDeriveInt(ctxt, exp, input));
}

static int
xmlExpCheckCard(xmlExpNodePtr exp, xmlExpNodePtr sub) {
    int ret = 1;

    if (sub->c_max == -1) {
        if (exp->c_max != -1)
      ret = 0;
    } else if ((exp->c_max >= 0) && (exp->c_max < sub->c_max)) {
        ret = 0;
    }
#if 0
    if ((IS_NILLABLE(sub)) && (!IS_NILLABLE(exp)))
        ret = 0;
#endif
    return(ret);
}

static xmlExpNodePtr xmlExpExpDeriveInt(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp,
                                        xmlExpNodePtr sub);
/**
 * xmlExpDivide:
 * @ctxt: the expressions context
 * @exp: the englobing expression
 * @sub: the subexpression
 * @mult: the multiple expression
 * @remain: the remain from the derivation of the multiple
 *
 * Check if exp is a multiple of sub, i.e. if there is a finite number n
 * so that sub{n} subsume exp
 *
 * Returns the multiple value if successful, 0 if it is not a multiple
 *         and -1 in case of internal error.
 */

static int
xmlExpDivide(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp, xmlExpNodePtr sub,
             xmlExpNodePtr *mult, xmlExpNodePtr *remain) {
    int i;
    xmlExpNodePtr tmp, tmp2;

    if (mult != NULL) *mult = NULL;
    if (remain != NULL) *remain = NULL;
    if (exp->c_max == -1) return(0);
    if (IS_NILLABLE(exp) && (!IS_NILLABLE(sub))) return(0);

    for (i = 1;i <= exp->c_max;i++) {
        sub->ref++;
        tmp = xmlExpHashGetEntry(ctxt, XML_EXP_COUNT,
         sub, NULL, NULL, i, i);
  if (tmp == NULL) {
      return(-1);
  }
  if (!xmlExpCheckCard(tmp, exp)) {
      xmlExpFree(ctxt, tmp);
      continue;
  }
  tmp2 = xmlExpExpDeriveInt(ctxt, tmp, exp);
  if (tmp2 == NULL) {
      xmlExpFree(ctxt, tmp);
      return(-1);
  }
  if ((tmp2 != forbiddenExp) && (IS_NILLABLE(tmp2))) {
      if (remain != NULL)
          *remain = tmp2;
      else
          xmlExpFree(ctxt, tmp2);
      if (mult != NULL)
          *mult = tmp;
      else
          xmlExpFree(ctxt, tmp);
#ifdef DEBUG_DERIV
      printf("Divide succeeded %d\n", i);
#endif
      return(i);
  }
  xmlExpFree(ctxt, tmp);
  xmlExpFree(ctxt, tmp2);
    }
#ifdef DEBUG_DERIV
    printf("Divide failed\n");
#endif
    return(0);
}

/**
 * xmlExpExpDeriveInt:
 * @ctxt: the expressions context
 * @exp: the englobing expression
 * @sub: the subexpression
 *
 * Try to do a step of Brzozowski derivation but at a higher level
 * the input being a subexpression.
 *
 * Returns the resulting expression or NULL in case of internal error
 */
static xmlExpNodePtr
xmlExpExpDeriveInt(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp, xmlExpNodePtr sub) {
    xmlExpNodePtr ret, tmp, tmp2, tmp3;
    const xmlChar **tab;
    int len, i;

    /*
     * In case of equality and if the expression can only consume a finite
     * amount, then the derivation is empty
     */
    if ((exp == sub) && (exp->c_max >= 0)) {
#ifdef DEBUG_DERIV
        printf("Equal(exp, sub) and finite -> Empty\n");
#endif
        return(emptyExp);
    }
    /*
     * decompose sub sequence first
     */
    if (sub->type == XML_EXP_EMPTY) {
#ifdef DEBUG_DERIV
        printf("Empty(sub) -> Empty\n");
#endif
  exp->ref++;
        return(exp);
    }
    if (sub->type == XML_EXP_SEQ) {
#ifdef DEBUG_DERIV
        printf("Seq(sub) -> decompose\n");
#endif
        tmp = xmlExpExpDeriveInt(ctxt, exp, sub->exp_left);
  if (tmp == NULL)
      return(NULL);
  if (tmp == forbiddenExp)
      return(tmp);
  ret = xmlExpExpDeriveInt(ctxt, tmp, sub->exp_right);
  xmlExpFree(ctxt, tmp);
  return(ret);
    }
    if (sub->type == XML_EXP_OR) {
#ifdef DEBUG_DERIV
        printf("Or(sub) -> decompose\n");
#endif
        tmp = xmlExpExpDeriveInt(ctxt, exp, sub->exp_left);
  if (tmp == forbiddenExp)
      return(tmp);
  if (tmp == NULL)
      return(NULL);
  ret = xmlExpExpDeriveInt(ctxt, exp, sub->exp_right);
  if ((ret == NULL) || (ret == forbiddenExp)) {
      xmlExpFree(ctxt, tmp);
      return(ret);
  }
  return(xmlExpHashGetEntry(ctxt, XML_EXP_OR, tmp, ret, NULL, 0, 0));
    }
    if (!xmlExpCheckCard(exp, sub)) {
#ifdef DEBUG_DERIV
        printf("CheckCard(exp, sub) failed -> Forbid\n");
#endif
        return(forbiddenExp);
    }
    switch (exp->type) {
        case XML_EXP_EMPTY:
      if (sub == emptyExp)
          return(emptyExp);
#ifdef DEBUG_DERIV
      printf("Empty(exp) -> Forbid\n");
#endif
      return(forbiddenExp);
        case XML_EXP_FORBID:
#ifdef DEBUG_DERIV
      printf("Forbid(exp) -> Forbid\n");
#endif
      return(forbiddenExp);
        case XML_EXP_ATOM:
      if (sub->type == XML_EXP_ATOM) {
          /* TODO: handle wildcards */
          if (exp->exp_str == sub->exp_str) {
#ifdef DEBUG_DERIV
        printf("Atom match -> Empty\n");
#endif
        return(emptyExp);
                }
#ifdef DEBUG_DERIV
    printf("Atom mismatch -> Forbid\n");
#endif
          return(forbiddenExp);
      }
      if ((sub->type == XML_EXP_COUNT) &&
          (sub->exp_max == 1) &&
          (sub->exp_left->type == XML_EXP_ATOM)) {
          /* TODO: handle wildcards */
          if (exp->exp_str == sub->exp_left->exp_str) {
#ifdef DEBUG_DERIV
        printf("Atom match -> Empty\n");
#endif
        return(emptyExp);
    }
#ifdef DEBUG_DERIV
    printf("Atom mismatch -> Forbid\n");
#endif
          return(forbiddenExp);
      }
#ifdef DEBUG_DERIV
      printf("Complex exp vs Atom -> Forbid\n");
#endif
      return(forbiddenExp);
        case XML_EXP_SEQ:
      /* try to get the sequence consumed only if possible */
      if (xmlExpCheckCard(exp->exp_left, sub)) {
    /* See if the sequence can be consumed directly */
#ifdef DEBUG_DERIV
    printf("Seq trying left only\n");
#endif
    ret = xmlExpExpDeriveInt(ctxt, exp->exp_left, sub);
    if ((ret != forbiddenExp) && (ret != NULL)) {
#ifdef DEBUG_DERIV
        printf("Seq trying left only worked\n");
#endif
        /*
         * TODO: assumption here that we are determinist
         *       i.e. we won't get to a nillable exp left
         *       subset which could be matched by the right
         *       part too.
         * e.g.: (a | b)+,(a | c) and 'a+,a'
         */
        exp->exp_right->ref++;
        return(xmlExpHashGetEntry(ctxt, XML_EXP_SEQ, ret,
                exp->exp_right, NULL, 0, 0));
    }
#ifdef DEBUG_DERIV
      } else {
    printf("Seq: left too short\n");
#endif
      }
      /* Try instead to decompose */
      if (sub->type == XML_EXP_COUNT) {
    int min, max;

#ifdef DEBUG_DERIV
    printf("Seq: sub is a count\n");
#endif
          ret = xmlExpExpDeriveInt(ctxt, exp->exp_left, sub->exp_left);
    if (ret == NULL)
        return(NULL);
    if (ret != forbiddenExp) {
#ifdef DEBUG_DERIV
        printf("Seq , Count match on left\n");
#endif
        if (sub->exp_max < 0)
            max = -1;
              else
            max = sub->exp_max -1;
        if (sub->exp_min > 0)
            min = sub->exp_min -1;
        else
            min = 0;
        exp->exp_right->ref++;
        tmp = xmlExpHashGetEntry(ctxt, XML_EXP_SEQ, ret,
                                 exp->exp_right, NULL, 0, 0);
        if (tmp == NULL)
            return(NULL);

        sub->exp_left->ref++;
        tmp2 = xmlExpHashGetEntry(ctxt, XML_EXP_COUNT,
              sub->exp_left, NULL, NULL, min, max);
        if (tmp2 == NULL) {
            xmlExpFree(ctxt, tmp);
      return(NULL);
        }
        ret = xmlExpExpDeriveInt(ctxt, tmp, tmp2);
        xmlExpFree(ctxt, tmp);
        xmlExpFree(ctxt, tmp2);
        return(ret);
    }
      }
      /* we made no progress on structured operations */
      break;
        case XML_EXP_OR:
#ifdef DEBUG_DERIV
      printf("Or , trying both side\n");
#endif
      ret = xmlExpExpDeriveInt(ctxt, exp->exp_left, sub);
      if (ret == NULL)
          return(NULL);
      tmp = xmlExpExpDeriveInt(ctxt, exp->exp_right, sub);
      if (tmp == NULL) {
    xmlExpFree(ctxt, ret);
          return(NULL);
      }
      return(xmlExpHashGetEntry(ctxt, XML_EXP_OR, ret, tmp, NULL, 0, 0));
        case XML_EXP_COUNT: {
      int min, max;

      if (sub->type == XML_EXP_COUNT) {
          /*
     * Try to see if the loop is completely subsumed
     */
          tmp = xmlExpExpDeriveInt(ctxt, exp->exp_left, sub->exp_left);
    if (tmp == NULL)
        return(NULL);
    if (tmp == forbiddenExp) {
        int mult;

#ifdef DEBUG_DERIV
        printf("Count, Count inner don't subsume\n");
#endif
        mult = xmlExpDivide(ctxt, sub->exp_left, exp->exp_left,
                            NULL, &tmp);
        if (mult <= 0) {
#ifdef DEBUG_DERIV
      printf("Count, Count not multiple => forbidden\n");
#endif
                        return(forbiddenExp);
        }
        if (sub->exp_max == -1) {
            max = -1;
      if (exp->exp_max == -1) {
          if (exp->exp_min <= sub->exp_min * mult)
              min = 0;
          else
              min = exp->exp_min - sub->exp_min * mult;
      } else {
#ifdef DEBUG_DERIV
          printf("Count, Count finite can't subsume infinite\n");
#endif
                            xmlExpFree(ctxt, tmp);
          return(forbiddenExp);
      }
        } else {
      if (exp->exp_max == -1) {
#ifdef DEBUG_DERIV
          printf("Infinite loop consume mult finite loop\n");
#endif
          if (exp->exp_min > sub->exp_min * mult) {
        max = -1;
        min = exp->exp_min - sub->exp_min * mult;
          } else {
        max = -1;
        min = 0;
          }
      } else {
          if (exp->exp_max < sub->exp_max * mult) {
#ifdef DEBUG_DERIV
        printf("loops max mult mismatch => forbidden\n");
#endif
        xmlExpFree(ctxt, tmp);
        return(forbiddenExp);
          }
          if (sub->exp_max * mult > exp->exp_min)
        min = 0;
          else
        min = exp->exp_min - sub->exp_max * mult;
          max = exp->exp_max - sub->exp_max * mult;
      }
        }
    } else if (!IS_NILLABLE(tmp)) {
        /*
         * TODO: loop here to try to grow if working on finite
         *       blocks.
         */
#ifdef DEBUG_DERIV
        printf("Count, Count remain not nillable => forbidden\n");
#endif
        xmlExpFree(ctxt, tmp);
        return(forbiddenExp);
    } else if (sub->exp_max == -1) {
        if (exp->exp_max == -1) {
            if (exp->exp_min <= sub->exp_min) {
#ifdef DEBUG_DERIV
          printf("Infinite loops Okay => COUNT(0,Inf)\n");
#endif
                            max = -1;
          min = 0;
      } else {
#ifdef DEBUG_DERIV
          printf("Infinite loops min => Count(X,Inf)\n");
#endif
                            max = -1;
          min = exp->exp_min - sub->exp_min;
      }
        } else if (exp->exp_min > sub->exp_min) {
#ifdef DEBUG_DERIV
      printf("loops min mismatch 1 => forbidden ???\n");
#endif
            xmlExpFree(ctxt, tmp);
            return(forbiddenExp);
        } else {
      max = -1;
      min = 0;
        }
    } else {
        if (exp->exp_max == -1) {
#ifdef DEBUG_DERIV
      printf("Infinite loop consume finite loop\n");
#endif
            if (exp->exp_min > sub->exp_min) {
          max = -1;
          min = exp->exp_min - sub->exp_min;
      } else {
          max = -1;
          min = 0;
      }
        } else {
            if (exp->exp_max < sub->exp_max) {
#ifdef DEBUG_DERIV
          printf("loops max mismatch => forbidden\n");
#endif
          xmlExpFree(ctxt, tmp);
          return(forbiddenExp);
      }
      if (sub->exp_max > exp->exp_min)
          min = 0;
      else
          min = exp->exp_min - sub->exp_max;
      max = exp->exp_max - sub->exp_max;
        }
    }
#ifdef DEBUG_DERIV
    printf("loops match => SEQ(COUNT())\n");
#endif
    exp->exp_left->ref++;
    tmp2 = xmlExpHashGetEntry(ctxt, XML_EXP_COUNT, exp->exp_left,
                              NULL, NULL, min, max);
    if (tmp2 == NULL) {
        return(NULL);
    }
                ret = xmlExpHashGetEntry(ctxt, XML_EXP_SEQ, tmp, tmp2,
                             NULL, 0, 0);
    return(ret);
      }
      tmp = xmlExpExpDeriveInt(ctxt, exp->exp_left, sub);
      if (tmp == NULL)
    return(NULL);
      if (tmp == forbiddenExp) {
#ifdef DEBUG_DERIV
    printf("loop mismatch => forbidden\n");
#endif
    return(forbiddenExp);
      }
      if (exp->exp_min > 0)
    min = exp->exp_min - 1;
      else
    min = 0;
      if (exp->exp_max < 0)
    max = -1;
      else
    max = exp->exp_max - 1;

#ifdef DEBUG_DERIV
      printf("loop match => SEQ(COUNT())\n");
#endif
      exp->exp_left->ref++;
      tmp2 = xmlExpHashGetEntry(ctxt, XML_EXP_COUNT, exp->exp_left,
              NULL, NULL, min, max);
      if (tmp2 == NULL)
    return(NULL);
      ret = xmlExpHashGetEntry(ctxt, XML_EXP_SEQ, tmp, tmp2,
             NULL, 0, 0);
      return(ret);
  }
    }

#ifdef DEBUG_DERIV
    printf("Fallback to derivative\n");
#endif
    if (IS_NILLABLE(sub)) {
        if (!(IS_NILLABLE(exp)))
      return(forbiddenExp);
  else
      ret = emptyExp;
    } else
  ret = NULL;
    /*
     * here the structured derivation made no progress so
     * we use the default token based derivation to force one more step
     */
    if (ctxt->tabSize == 0)
        ctxt->tabSize = 40;

    tab = (const xmlChar **) xmlMalloc(ctxt->tabSize *
                                 sizeof(const xmlChar *));
    if (tab == NULL) {
  return(NULL);
    }

    /*
     * collect all the strings accepted by the subexpression on input
     */
    len = xmlExpGetStartInt(ctxt, sub, tab, ctxt->tabSize, 0);
    while (len < 0) {
        const xmlChar **temp;
  temp = (const xmlChar **) xmlRealloc((xmlChar **) tab, ctxt->tabSize * 2 *
                                       sizeof(const xmlChar *));
  if (temp == NULL) {
      xmlFree((xmlChar **) tab);
      return(NULL);
  }
  tab = temp;
  ctxt->tabSize *= 2;
  len = xmlExpGetStartInt(ctxt, sub, tab, ctxt->tabSize, 0);
    }
    for (i = 0;i < len;i++) {
        tmp = xmlExpStringDeriveInt(ctxt, exp, tab[i]);
  if ((tmp == NULL) || (tmp == forbiddenExp)) {
      xmlExpFree(ctxt, ret);
      xmlFree((xmlChar **) tab);
      return(tmp);
  }
  tmp2 = xmlExpStringDeriveInt(ctxt, sub, tab[i]);
  if ((tmp2 == NULL) || (tmp2 == forbiddenExp)) {
      xmlExpFree(ctxt, tmp);
      xmlExpFree(ctxt, ret);
      xmlFree((xmlChar **) tab);
      return(tmp);
  }
  tmp3 = xmlExpExpDeriveInt(ctxt, tmp, tmp2);
  xmlExpFree(ctxt, tmp);
  xmlExpFree(ctxt, tmp2);

  if ((tmp3 == NULL) || (tmp3 == forbiddenExp)) {
      xmlExpFree(ctxt, ret);
      xmlFree((xmlChar **) tab);
      return(tmp3);
  }

  if (ret == NULL)
      ret = tmp3;
  else {
      ret = xmlExpHashGetEntry(ctxt, XML_EXP_OR, ret, tmp3, NULL, 0, 0);
      if (ret == NULL) {
    xmlFree((xmlChar **) tab);
          return(NULL);
      }
  }
    }
    xmlFree((xmlChar **) tab);
    return(ret);
}

/**
 * xmlExpExpDerive:
 * @ctxt: the expressions context
 * @exp: the englobing expression
 * @sub: the subexpression
 *
 * Evaluates the expression resulting from @exp consuming a sub expression @sub
 * Based on algebraic derivation and sometimes direct Brzozowski derivation
 * it usually takes less than linear time and can handle expressions generating
 * infinite languages.
 *
 * Returns the resulting expression or NULL in case of internal error, the
 *         result must be freed
 */
xmlExpNodePtr
xmlExpExpDerive(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp, xmlExpNodePtr sub) {
    if ((exp == NULL) || (ctxt == NULL) || (sub == NULL))
        return(NULL);

    /*
     * O(1) speedups
     */
    if (IS_NILLABLE(sub) && (!IS_NILLABLE(exp))) {
#ifdef DEBUG_DERIV
  printf("Sub nillable and not exp : can't subsume\n");
#endif
        return(forbiddenExp);
    }
    if (xmlExpCheckCard(exp, sub) == 0) {
#ifdef DEBUG_DERIV
  printf("sub generate longer sequences than exp : can't subsume\n");
#endif
        return(forbiddenExp);
    }
    return(xmlExpExpDeriveInt(ctxt, exp, sub));
}

/**
 * xmlExpSubsume:
 * @ctxt: the expressions context
 * @exp: the englobing expression
 * @sub: the subexpression
 *
 * Check whether @exp accepts all the languages accepted by @sub
 * the input being a subexpression.
 *
 * Returns 1 if true 0 if false and -1 in case of failure.
 */
int
xmlExpSubsume(xmlExpCtxtPtr ctxt, xmlExpNodePtr exp, xmlExpNodePtr sub) {
    xmlExpNodePtr tmp;

    if ((exp == NULL) || (ctxt == NULL) || (sub == NULL))
        return(-1);

    /*
     * TODO: speedup by checking the language of sub is a subset of the
     *       language of exp
     */
    /*
     * O(1) speedups
     */
    if (IS_NILLABLE(sub) && (!IS_NILLABLE(exp))) {
#ifdef DEBUG_DERIV
  printf("Sub nillable and not exp : can't subsume\n");
#endif
        return(0);
    }
    if (xmlExpCheckCard(exp, sub) == 0) {
#ifdef DEBUG_DERIV
  printf("sub generate longer sequences than exp : can't subsume\n");
#endif
        return(0);
    }
    tmp = xmlExpExpDeriveInt(ctxt, exp, sub);
#ifdef DEBUG_DERIV
    printf("Result derivation :\n");
    PRINT_EXP(tmp);
#endif
    if (tmp == NULL)
        return(-1);
    if (tmp == forbiddenExp)
  return(0);
    if (tmp == emptyExp)
  return(1);
    if ((tmp != NULL) && (IS_NILLABLE(tmp))) {
        xmlExpFree(ctxt, tmp);
        return(1);
    }
    xmlExpFree(ctxt, tmp);
    return(0);
}

/************************************************************************
 *                  *
 *      Parsing expression        *
 *                  *
 ************************************************************************/

static xmlExpNodePtr xmlExpParseExpr(xmlExpCtxtPtr ctxt);

#undef CUR
#define CUR (*ctxt->cur)
#undef NEXT
#define NEXT ctxt->cur++;
#undef IS_BLANK
#define IS_BLANK(c) ((c == ' ') || (c == '\n') || (c == '\r') || (c == '\t'))
#define SKIP_BLANKS while (IS_BLANK(*ctxt->cur)) ctxt->cur++;

static int
xmlExpParseNumber(xmlExpCtxtPtr ctxt) {
    int ret = 0;

    SKIP_BLANKS
    if (CUR == '*') {
  NEXT
  return(-1);
    }
    if ((CUR < '0') || (CUR > '9'))
        return(-1);
    while ((CUR >= '0') && (CUR <= '9')) {
        ret = ret * 10 + (CUR - '0');
  NEXT
    }
    return(ret);
}

static xmlExpNodePtr
xmlExpParseOr(xmlExpCtxtPtr ctxt) {
    const char *base;
    xmlExpNodePtr ret;
    const xmlChar *val;

    SKIP_BLANKS
    base = ctxt->cur;
    if (*ctxt->cur == '(') {
        NEXT
  ret = xmlExpParseExpr(ctxt);
  SKIP_BLANKS
  if (*ctxt->cur != ')') {
      fprintf(stderr, "unbalanced '(' : %s\n", base);
      xmlExpFree(ctxt, ret);
      return(NULL);
  }
  NEXT;
  SKIP_BLANKS
  goto parse_quantifier;
    }
    while ((CUR != 0) && (!(IS_BLANK(CUR))) && (CUR != '(') &&
           (CUR != ')') && (CUR != '|') && (CUR != ',') && (CUR != '{') &&
     (CUR != '*') && (CUR != '+') && (CUR != '?') && (CUR != '}'))
  NEXT;
    val = xmlDictLookup(ctxt->dict, BAD_CAST base, ctxt->cur - base);
    if (val == NULL)
        return(NULL);
    ret = xmlExpHashGetEntry(ctxt, XML_EXP_ATOM, NULL, NULL, val, 0, 0);
    if (ret == NULL)
        return(NULL);
    SKIP_BLANKS
parse_quantifier:
    if (CUR == '{') {
        int min, max;

        NEXT
  min = xmlExpParseNumber(ctxt);
  if (min < 0) {
      xmlExpFree(ctxt, ret);
      return(NULL);
  }
  SKIP_BLANKS
  if (CUR == ',') {
      NEXT
      max = xmlExpParseNumber(ctxt);
      SKIP_BLANKS
  } else
      max = min;
  if (CUR != '}') {
      xmlExpFree(ctxt, ret);
      return(NULL);
  }
        NEXT
  ret = xmlExpHashGetEntry(ctxt, XML_EXP_COUNT, ret, NULL, NULL,
                           min, max);
  SKIP_BLANKS
    } else if (CUR == '?') {
        NEXT
  ret = xmlExpHashGetEntry(ctxt, XML_EXP_COUNT, ret, NULL, NULL,
                           0, 1);
  SKIP_BLANKS
    } else if (CUR == '+') {
        NEXT
  ret = xmlExpHashGetEntry(ctxt, XML_EXP_COUNT, ret, NULL, NULL,
                           1, -1);
  SKIP_BLANKS
    } else if (CUR == '*') {
        NEXT
  ret = xmlExpHashGetEntry(ctxt, XML_EXP_COUNT, ret, NULL, NULL,
                           0, -1);
  SKIP_BLANKS
    }
    return(ret);
}


static xmlExpNodePtr
xmlExpParseSeq(xmlExpCtxtPtr ctxt) {
    xmlExpNodePtr ret, right;

    ret = xmlExpParseOr(ctxt);
    SKIP_BLANKS
    while (CUR == '|') {
        NEXT
  right = xmlExpParseOr(ctxt);
  if (right == NULL) {
      xmlExpFree(ctxt, ret);
      return(NULL);
  }
  ret = xmlExpHashGetEntry(ctxt, XML_EXP_OR, ret, right, NULL, 0, 0);
  if (ret == NULL)
      return(NULL);
    }
    return(ret);
}

static xmlExpNodePtr
xmlExpParseExpr(xmlExpCtxtPtr ctxt) {
    xmlExpNodePtr ret, right;

    ret = xmlExpParseSeq(ctxt);
    SKIP_BLANKS
    while (CUR == ',') {
        NEXT
  right = xmlExpParseSeq(ctxt);
  if (right == NULL) {
      xmlExpFree(ctxt, ret);
      return(NULL);
  }
  ret = xmlExpHashGetEntry(ctxt, XML_EXP_SEQ, ret, right, NULL, 0, 0);
  if (ret == NULL)
      return(NULL);
    }
    return(ret);
}

/**
 * xmlExpParse:
 * @ctxt: the expressions context
 * @expr: the 0 terminated string
 *
 * Minimal parser for regexps, it understand the following constructs
 *  - string terminals
 *  - choice operator |
 *  - sequence operator ,
 *  - subexpressions (...)
 *  - usual cardinality operators + * and ?
 *  - finite sequences  { min, max }
 *  - infinite sequences { min, * }
 * There is minimal checkings made especially no checking on strings values
 *
 * Returns a new expression or NULL in case of failure
 */
xmlExpNodePtr
xmlExpParse(xmlExpCtxtPtr ctxt, const char *expr) {
    xmlExpNodePtr ret;

    ctxt->expr = expr;
    ctxt->cur = expr;

    ret = xmlExpParseExpr(ctxt);
    SKIP_BLANKS
    if (*ctxt->cur != 0) {
        xmlExpFree(ctxt, ret);
        return(NULL);
    }
    return(ret);
}

static void
xmlExpDumpInt(xmlBufferPtr buf, xmlExpNodePtr expr, int glob) {
    xmlExpNodePtr c;

    if (expr == NULL) return;
    if (glob) xmlBufferWriteChar(buf, "(");
    switch (expr->type) {
        case XML_EXP_EMPTY:
      xmlBufferWriteChar(buf, "empty");
      break;
        case XML_EXP_FORBID:
      xmlBufferWriteChar(buf, "forbidden");
      break;
        case XML_EXP_ATOM:
      xmlBufferWriteCHAR(buf, expr->exp_str);
      break;
        case XML_EXP_SEQ:
      c = expr->exp_left;
      if ((c->type == XML_EXP_SEQ) || (c->type == XML_EXP_OR))
          xmlExpDumpInt(buf, c, 1);
      else
          xmlExpDumpInt(buf, c, 0);
      xmlBufferWriteChar(buf, " , ");
      c = expr->exp_right;
      if ((c->type == XML_EXP_SEQ) || (c->type == XML_EXP_OR))
          xmlExpDumpInt(buf, c, 1);
      else
          xmlExpDumpInt(buf, c, 0);
            break;
        case XML_EXP_OR:
      c = expr->exp_left;
      if ((c->type == XML_EXP_SEQ) || (c->type == XML_EXP_OR))
          xmlExpDumpInt(buf, c, 1);
      else
          xmlExpDumpInt(buf, c, 0);
      xmlBufferWriteChar(buf, " | ");
      c = expr->exp_right;
      if ((c->type == XML_EXP_SEQ) || (c->type == XML_EXP_OR))
          xmlExpDumpInt(buf, c, 1);
      else
          xmlExpDumpInt(buf, c, 0);
            break;
        case XML_EXP_COUNT: {
      char rep[40];

      c = expr->exp_left;
      if ((c->type == XML_EXP_SEQ) || (c->type == XML_EXP_OR))
          xmlExpDumpInt(buf, c, 1);
      else
          xmlExpDumpInt(buf, c, 0);
      if ((expr->exp_min == 0) && (expr->exp_max == 1)) {
    rep[0] = '?';
    rep[1] = 0;
      } else if ((expr->exp_min == 0) && (expr->exp_max == -1)) {
    rep[0] = '*';
    rep[1] = 0;
      } else if ((expr->exp_min == 1) && (expr->exp_max == -1)) {
    rep[0] = '+';
    rep[1] = 0;
      } else if (expr->exp_max == expr->exp_min) {
          snprintf(rep, 39, "{%d}", expr->exp_min);
      } else if (expr->exp_max < 0) {
          snprintf(rep, 39, "{%d,inf}", expr->exp_min);
      } else {
          snprintf(rep, 39, "{%d,%d}", expr->exp_min, expr->exp_max);
      }
      rep[39] = 0;
      xmlBufferWriteChar(buf, rep);
      break;
  }
  default:
      fprintf(stderr, "Error in tree\n");
    }
    if (glob)
        xmlBufferWriteChar(buf, ")");
}
/**
 * xmlExpDump:
 * @buf:  a buffer to receive the output
 * @expr:  the compiled expression
 *
 * Serialize the expression as compiled to the buffer
 */
void
xmlExpDump(xmlBufferPtr buf, xmlExpNodePtr expr) {
    if ((buf == NULL) || (expr == NULL))
        return;
    xmlExpDumpInt(buf, expr, 0);
}

/**
 * xmlExpMaxToken:
 * @expr: a compiled expression
 *
 * Indicate the maximum number of input a expression can accept
 *
 * Returns the maximum length or -1 in case of error
 */
int
xmlExpMaxToken(xmlExpNodePtr expr) {
    if (expr == NULL)
        return(-1);
    return(expr->c_max);
}

/**
 * xmlExpCtxtNbNodes:
 * @ctxt: an expression context
 *
 * Debugging facility provides the number of allocated nodes at a that point
 *
 * Returns the number of nodes in use or -1 in case of error
 */
int
xmlExpCtxtNbNodes(xmlExpCtxtPtr ctxt) {
    if (ctxt == NULL)
        return(-1);
    return(ctxt->nb_nodes);
}

/**
 * xmlExpCtxtNbCons:
 * @ctxt: an expression context
 *
 * Debugging facility provides the number of allocated nodes over lifetime
 *
 * Returns the number of nodes ever allocated or -1 in case of error
 */
int
xmlExpCtxtNbCons(xmlExpCtxtPtr ctxt) {
    if (ctxt == NULL)
        return(-1);
    return(ctxt->nb_cons);
}

#endif /* LIBXML_EXPR_ENABLED */

#endif /* LIBXML_REGEXP_ENABLED */

Coverage Report

Created: 2023-06-07 06:54