gecko/xpcom/io/nsWildCard.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* *
 *
 *
 * nsWildCard.cpp: shell-like wildcard match routines
 *
 * See nsIZipReader.findEntries documentation in nsIZipReader.idl for
 * a description of the syntax supported by the routines in this file.
 *
 * Rob McCool
 *
 */

#include "nsWildCard.h"
#include "nsXPCOM.h"
#include "nsCRTGlue.h"
#include "nsCharTraits.h"

/* -------------------- ASCII-specific character methods ------------------- */

typedef int static_assert_character_code_arrangement['a' > 'A' ? 1 : -1];

template<class T>
static int
alpha(T c)
{
  return ('a' <= c && c <= 'z') ||
         ('A' <= c && c <= 'Z');
}

template<class T>
static int
alphanumeric(T c)
{
  return ('0' <= c && c <= '9') || ::alpha(c);
}

template<class T>
static int
lower(T c)
{
  return ('A' <= c && c <= 'Z') ? c + ('a' - 'A') : c;
}

template<class T>
static int
upper(T c)
{
  return ('a' <= c && c <= 'z') ? c - ('a' - 'A') : c;
}

/* ----------------------------- _valid_subexp ---------------------------- */

template<class T>
static int
_valid_subexp(const T *expr, T stop1, T stop2)
{
  int x;
  int nsc = 0;     /* Number of special characters */
  int np;          /* Number of pipe characters in union */
  int tld = 0;     /* Number of tilde characters */

  for (x = 0; expr[x] && (expr[x] != stop1) && (expr[x] != stop2); ++x) {
    switch(expr[x]) {
      case '~':
        if(tld)                 /* at most one exclusion */
          return INVALID_SXP;
        if (stop1)              /* no exclusions within unions */
          return INVALID_SXP;
        if (!expr[x+1])         /* exclusion cannot be last character */
          return INVALID_SXP;
        if (!x)                 /* exclusion cannot be first character */
          return INVALID_SXP;
        ++tld;
        /* fall through */
      case '*':
      case '?':
      case '$':
        ++nsc;
        break;
      case '[':
        ++nsc;
        if((!expr[++x]) || (expr[x] == ']'))
          return INVALID_SXP;
        for(; expr[x] && (expr[x] != ']'); ++x) {
          if(expr[x] == '\\' && !expr[++x])
            return INVALID_SXP;
        }
        if(!expr[x])
          return INVALID_SXP;
        break;
      case '(':
        ++nsc;
        if (stop1)                  /* no nested unions */
          return INVALID_SXP;
        np = -1;
        do {
          int t = ::_valid_subexp(&expr[++x], T(')'), T('|'));
          if(t == 0 || t == INVALID_SXP)
            return INVALID_SXP;
          x+=t;
          if(!expr[x])
            return INVALID_SXP;
          ++np;
        } while (expr[x] == '|' );
        if(np < 1)  /* must be at least one pipe */
          return INVALID_SXP;
        break;
      case ')':
      case ']':
      case '|':
        return INVALID_SXP;
      case '\\':
        ++nsc;
        if(!expr[++x])
          return INVALID_SXP;
        break;
      default:
        break;
    }
  }
  if((!stop1) && (!nsc)) /* must be at least one special character */
    return NON_SXP;
  return ((expr[x] == stop1 || expr[x] == stop2) ? x : INVALID_SXP);
}


template<class T>
int
NS_WildCardValid_(const T *expr)
{
  int x = ::_valid_subexp(expr, T('\0'), T('\0'));
  return (x < 0 ? x : VALID_SXP);
}

int
NS_WildCardValid(const char *expr)
{
  return NS_WildCardValid_(expr);
}

int
NS_WildCardValid(const char16_t *expr)
{
  return NS_WildCardValid_(expr);
}

/* ----------------------------- _shexp_match ----------------------------- */


#define MATCH 0
#define NOMATCH 1
#define ABORTED -1

template<class T>
static int
_shexp_match(const T *str, const T *expr, bool case_insensitive, unsigned int level);

/**
 * Count characters until we reach a NUL character or either of the
 * two delimiter characters, stop1 or stop2.  If we encounter a bracketed
 * expression, look only for NUL or ']' inside it.  Do not look for stop1
 * or stop2 inside it. Return ABORTED if bracketed expression is unterminated.
 * Handle all escaping.
 * Return index in input string of first stop found, or ABORTED if not found.
 * If "dest" is non-nullptr, copy counted characters to it and null terminate.
 */
template<class T>
static int
_scan_and_copy(const T *expr, T stop1, T stop2, T *dest)
{
  int sx;     /* source index */
  T cc;

  for (sx = 0; (cc = expr[sx]) && cc != stop1 && cc != stop2; sx++) {
    if (cc == '\\') {
      if (!expr[++sx])
        return ABORTED; /* should be impossible */
    }
    else if (cc == '[') {
      while ((cc = expr[++sx]) && cc != ']') {
        if(cc == '\\' && !expr[++sx])
          return ABORTED;
      }
      if (!cc)
        return ABORTED; /* should be impossible */
    }
  }
  if (dest && sx) {
    /* Copy all but the closing delimiter. */
    memcpy(dest, expr, sx * sizeof(T));
    dest[sx] = 0;
  }
  return cc ? sx : ABORTED; /* index of closing delimiter */
}

/* On input, expr[0] is the opening parenthesis of a union.
 * See if any of the alternatives in the union matches as a pattern.
 * The strategy is to take each of the alternatives, in turn, and append
 * the rest of the expression (after the closing ')' that marks the end of
 * this union) to that alternative, and then see if the resultant expression
 * matches the input string.  Repeat this until some alternative matches,
 * or we have an abort.
 */
template<class T>
static int
_handle_union(const T *str, const T *expr, bool case_insensitive,
              unsigned int level)
{
  int sx;              /* source index */
  int cp;              /* source index of closing parenthesis */
  int count;
  int ret   = NOMATCH;
  T *e2;

  /* Find the closing parenthesis that ends this union in the expression */
  cp = ::_scan_and_copy(expr, T(')'), T('\0'), static_cast<T*>(nullptr));
  if (cp == ABORTED || cp < 4) /* must be at least "(a|b" before ')' */
    return ABORTED;
  ++cp;                /* now index of char after closing parenthesis */
  e2 = (T *) NS_Alloc((1 + nsCharTraits<T>::length(expr)) * sizeof(T));
  if (!e2)
    return ABORTED;
  for (sx = 1; ; ++sx) {
    /* Here, expr[sx] is one character past the preceding '(' or '|'. */
    /* Copy everything up to the next delimiter to e2 */
    count = ::_scan_and_copy(expr + sx, T(')'), T('|'), e2);
    if (count == ABORTED || !count) {
      ret = ABORTED;
      break;
    }
    sx += count;
    /* Append everything after closing parenthesis to e2. This is safe. */
    nsCharTraits<T>::copy(e2 + count, expr + cp, nsCharTraits<T>::length(expr + cp) + 1);
    ret = ::_shexp_match(str, e2, case_insensitive, level + 1);
    if (ret != NOMATCH || !expr[sx] || expr[sx] == ')')
      break;
  }
  NS_Free(e2);
  if (sx < 2)
    ret = ABORTED;
  return ret;
}

/* returns 1 if val is in range from start..end, case insensitive. */
static int
_is_char_in_range(unsigned char start, unsigned char end, unsigned char val)
{
  char map[256];
  memset(map, 0, sizeof map);
  while (start <= end)
    map[lower(start++)] = 1;
  return map[lower(val)];
}

template<class T>
static int
_shexp_match(const T *str, const T *expr, bool case_insensitive,
             unsigned int level)
{
  int x;   /* input string index */
  int y;   /* expression index */
  int ret,neg;

  if (level > 20)      /* Don't let the stack get too deep. */
    return ABORTED;
  for(x = 0, y = 0; expr[y]; ++y, ++x) {
    if((!str[x]) && (expr[y] != '$') && (expr[y] != '*')) {
      return NOMATCH;
    }
    switch(expr[y]) {
      case '$':
        if(str[x])
          return NOMATCH;
        --x;                 /* we don't want loop to increment x */
        break;
      case '*':
        while(expr[++y] == '*'){}
        if(!expr[y])
          return MATCH;
        while(str[x]) {
          ret = ::_shexp_match(&str[x++], &expr[y], case_insensitive,
                               level + 1);
          switch(ret) {
            case NOMATCH:
              continue;
            case ABORTED:
              return ABORTED;
            default:
              return MATCH;
          }
        }
        if((expr[y] == '$') && (expr[y+1] == '\0') && (!str[x]))
          return MATCH;
        else
          return NOMATCH;
      case '[': {
        T start, end = 0;
        int i;
        neg = ((expr[++y] == '^') && (expr[y+1] != ']'));
        if (neg)
          ++y;
        i = y;
        start = expr[i++];
        if (start == '\\')
          start = expr[i++];
        if (::alphanumeric(start) && expr[i++] == '-') {
          end = expr[i++];
          if (end == '\\')
            end = expr[i++];
        }
        if (::alphanumeric(end) && expr[i] == ']') {
          /* This is a range form: a-b */
          T val = str[x];
          if (end < start) { /* swap them */
            T tmp = end;
            end = start;
            start = tmp;
          }
          if (case_insensitive && ::alpha(val)) {
            val = ::_is_char_in_range((unsigned char) start,
                                      (unsigned char) end,
                                      (unsigned char) val);
            if (neg == val)
              return NOMATCH;
          }
          else if (neg != ((val < start) || (val > end))) {
            return NOMATCH;
          }
          y = i;
        }
        else {
          /* Not range form */
          int matched = 0;
          for (; expr[y] != ']'; y++) {
            if (expr[y] == '\\')
              ++y;
            if(case_insensitive)
              matched |= (::upper(str[x]) == ::upper(expr[y]));
            else
              matched |= (str[x] == expr[y]);
          }
          if (neg == matched)
            return NOMATCH;
        }
      }
      break;
      case '(':
        if (!expr[y+1])
          return ABORTED;
        return ::_handle_union(&str[x], &expr[y], case_insensitive, level + 1);
      case '?':
        break;
      case ')':
      case ']':
      case '|':
        return ABORTED;
      case '\\':
        ++y;
        /* fall through */
      default:
        if(case_insensitive) {
          if(::upper(str[x]) != ::upper(expr[y]))
            return NOMATCH;
        }
        else {
          if(str[x] != expr[y])
            return NOMATCH;
        }
        break;
    }
  }
  return (str[x] ? NOMATCH : MATCH);
}


template<class T>
static int
ns_WildCardMatch(const T *str, const T *xp, bool case_insensitive)
{
  T *expr = nullptr;
  int x, ret = MATCH;

  if (!nsCharTraits<T>::find(xp, nsCharTraits<T>::length(xp), T('~')))
    return ::_shexp_match(str, xp, case_insensitive, 0);

  expr = (T *) NS_Alloc((nsCharTraits<T>::length(xp) + 1) * sizeof(T));
  if(!expr)
    return NOMATCH;
  memcpy(expr, xp, (nsCharTraits<T>::length(xp) + 1) * sizeof(T));

  x = ::_scan_and_copy(expr, T('~'), T('\0'), static_cast<T*>(nullptr));
  if (x != ABORTED && expr[x] == '~') {
    expr[x++] = '\0';
    ret = ::_shexp_match(str, &expr[x], case_insensitive, 0);
    switch (ret) {
      case NOMATCH: ret = MATCH;   break;
      case MATCH:   ret = NOMATCH; break;
      default:                     break;
    }
  }
  if (ret == MATCH)
    ret = ::_shexp_match(str, expr, case_insensitive, 0);

  NS_Free(expr);
  return ret;
}

template<class T>
int
NS_WildCardMatch_(const T *str, const T *expr, bool case_insensitive)
{
  int is_valid = NS_WildCardValid(expr);
  switch(is_valid) {
    case INVALID_SXP:
      return -1;
    default:
      return ::ns_WildCardMatch(str, expr, case_insensitive);
  }
}

int
NS_WildCardMatch(const char *str, const char *xp,
                 bool case_insensitive)
{
  return NS_WildCardMatch_(str, xp, case_insensitive);
}

int
NS_WildCardMatch(const char16_t *str, const char16_t *xp,
                 bool case_insensitive)
{
  return NS_WildCardMatch_(str, xp, case_insensitive);
}