xemacs-beta: src/regex.c comparison

comparison src/regex.c @ 0:376386a54a3c r19-14

Import from CVS: tag r19-14

author	cvs
date	Mon, 13 Aug 2007 08:45:50 +0200
parents
children	ac2d302a0011

comparison

equal deleted inserted replaced

--1:000000000000
+:376386a54a3c
+/* Extended regular expression matching and search library,
+version 0.12, extended for XEmacs.
+(Implements POSIX draft P10003.2/D11.2, except for
+internationalization features.)
+Copyright (C) 1993, 1994, 1995 Free Software Foundation, Inc.
+Copyright (C) 1995 Sun Microsystems, Inc.
+Copyright (C) 1995 Ben Wing.
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program; see the file COPYING.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA. */
+/* Synched up with: FSF 19.29. */
+/* Changes made for XEmacs:
+(1) the REGEX_BEGLINE_CHECK code from the XEmacs v18 regex routines
+was added.  This causes a huge speedup in font-locking.
+(2) Rel-alloc is disabled when the MMAP version of rel-alloc is
+being used, because it's too slow -- all those calls to mmap()
+add humongous overhead.
+*/
+/* AIX requires this to be the first thing in the file. */
+#if defined (_AIX) && !defined (REGEX_MALLOC)
+#pragma alloca
+#endif
+#define _GNU_SOURCE
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+/* We need this for `regex.h', and perhaps for the Emacs include files.  */
+#include <sys/types.h>
+/* This is for other GNU distributions with internationalized messages.  */
+#if defined (I18N3) && (defined (HAVE_LIBINTL_H) || defined (_LIBC))
+# include <libintl.h>
+#else
+# define gettext(msgid) (msgid)
+#endif
+/* XEmacs: define this to add in a speedup for patterns anchored at
+the beginning of a line.  Keep the ifdefs so that it's easier to
+tell where/why this code has diverged from v19. */
+#define REGEX_BEGLINE_CHECK
+/* XEmacs: the current mmap-based ralloc handles small blocks very
+poorly, so we disable it here. */
+#if defined (REL_ALLOC) && defined (HAVE_MMAP)
+# undef REL_ALLOC
+#endif
+/* The `emacs' switch turns on certain matching commands
+that make sense only in Emacs. */
+#ifdef emacs
+#include "lisp.h"
+#include "buffer.h"
+#include "syntax.h"
+#if (defined (DEBUG_XEMACS) && !defined (DEBUG))
+#define DEBUG
+#endif
+void
+complex_vars_of_regex (void)
+{
+}
+#else  /* not emacs */
+/* If we are not linking with Emacs proper,
+we can't use the relocating allocator
+even if config.h says that we can.  */
+#undef REL_ALLOC
+#if defined (STDC_HEADERS) || defined (_LIBC)
+#include <stdlib.h>
+#else
+char *malloc ();
+char *realloc ();
+#endif
+#define charptr_emchar(str)		((Emchar) (str)[0])
+#if (LONGBITS > INTBITS)
+# define EMACS_INT long
+#else
+# define EMACS_INT int
+#endif
+typedef int Emchar;
+#define INC_CHARPTR(p) ((p)++)
+#define DEC_CHARPTR(p) ((p)--)
+/* When used in Emacs's lib-src, we need to get bzero and bcopy somehow.
+If nothing else has been done, use the method below.  */
+#ifdef INHIBIT_STRING_HEADER
+#if !(defined (HAVE_BZERO) && defined (HAVE_BCOPY))
+#if !defined (bzero) && !defined (bcopy)
+#undef INHIBIT_STRING_HEADER
+#endif
+#endif
+#endif
+/* This is the normal way of making sure we have a bcopy and a bzero.
+This is used in most programs--a few other programs avoid this
+by defining INHIBIT_STRING_HEADER.  */
+#ifndef INHIBIT_STRING_HEADER
+#if defined (HAVE_STRING_H) || defined (STDC_HEADERS) || defined (_LIBC)
+#include <string.h>
+#ifndef bcmp
+#define bcmp(s1, s2, n)	memcmp ((s1), (s2), (n))
+#endif
+#ifndef bcopy
+#define bcopy(s, d, n)	memcpy ((d), (s), (n))
+#endif
+#ifndef bzero
+#define bzero(s, n)	memset ((s), 0, (n))
+#endif
+#else
+#include <strings.h>
+#endif
+#endif
+/* Define the syntax stuff for \<, \>, etc.  */
+/* This must be nonzero for the wordchar and notwordchar pattern
+commands in re_match_2.  */
+#ifndef Sword
+#define Sword 1
+#endif
+#ifdef SYNTAX_TABLE
+extern char *re_syntax_table;
+#else /* not SYNTAX_TABLE */
+/* How many characters in the character set.  */
+#define CHAR_SET_SIZE 256
+static char re_syntax_table[CHAR_SET_SIZE];
+static void
+init_syntax_once (void)
+{
+register int c;
+static int done = 0;
+if (done)
+return;
+bzero (re_syntax_table, sizeof re_syntax_table);
+for (c = 'a'; c <= 'z'; c++)
+re_syntax_table[c] = Sword;
+for (c = 'A'; c <= 'Z'; c++)
+re_syntax_table[c] = Sword;
+for (c = '0'; c <= '9'; c++)
+re_syntax_table[c] = Sword;
+re_syntax_table['_'] = Sword;
+done = 1;
+}
+#endif /* not SYNTAX_TABLE */
+#define SYNTAX_UNSAFE(ignored, c) re_syntax_table[c]
+#endif /* not emacs */
+/* Under XEmacs, this is needed because we don't define it elsewhere. */
+#ifdef SWITCH_ENUM_BUG
+#define SWITCH_ENUM_CAST(x) ((int)(x))
+#else
+#define SWITCH_ENUM_CAST(x) (x)
+#endif
+/* Get the interface, including the syntax bits.  */
+#include "regex.h"
+/* isalpha etc. are used for the character classes.  */
+#include <ctype.h>
+/* Jim Meyering writes:
+"... Some ctype macros are valid only for character codes that
+isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
+using /bin/cc or gcc but without giving an ansi option).  So, all
+ctype uses should be through macros like ISPRINT...  If
+STDC_HEADERS is defined, then autoconf has verified that the ctype
+macros don't need to be guarded with references to isascii. ...
+Defining isascii to 1 should let any compiler worth its salt
+eliminate the && through constant folding."  */
+#if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
+#define ISASCII_1(c) 1
+#else
+#define ISASCII_1(c) isascii(c)
+#endif
+#define ISASCII(c) ISASCII_1 (c)
+#ifdef isblank
+#define ISBLANK(c) (ISASCII (c) && isblank (c))
+#else
+#define ISBLANK(c) ((c) == ' ' || (c) == '\t')
+#endif
+#ifdef isgraph
+#define ISGRAPH(c) (ISASCII (c) && isgraph (c))
+#else
+#define ISGRAPH(c) (ISASCII (c) && isprint (c) && !isspace (c))
+#endif
+#define ISPRINT(c) (ISASCII (c) && isprint (c))
+#define ISDIGIT(c) (ISASCII (c) && isdigit (c))
+#define ISALNUM(c) (ISASCII (c) && isalnum (c))
+#define ISALPHA(c) (ISASCII (c) && isalpha (c))
+#define ISCNTRL(c) (ISASCII (c) && iscntrl (c))
+#define ISLOWER(c) (ISASCII (c) && islower (c))
+#define ISPUNCT(c) (ISASCII (c) && ispunct (c))
+#define ISSPACE(c) (ISASCII (c) && isspace (c))
+#define ISUPPER(c) (ISASCII (c) && isupper (c))
+#define ISXDIGIT(c) (ISASCII (c) && isxdigit (c))
+#ifndef NULL
+#define NULL (void *)0
+#endif
+/* We remove any previous definition of `SIGN_EXTEND_CHAR',
+since ours (we hope) works properly with all combinations of
+machines, compilers, `char' and `unsigned char' argument types.
+(Per Bothner suggested the basic approach.)  */
+#undef SIGN_EXTEND_CHAR
+#if __STDC__
+#define SIGN_EXTEND_CHAR(c) ((signed char) (c))
+#else  /* not __STDC__ */
+/* As in Harbison and Steele.  */
+#define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
+#endif
+/* Should we use malloc or alloca?  If REGEX_MALLOC is not defined, we
+use `alloca' instead of `malloc'.  This is because using malloc in
+re_search* or re_match* could cause memory leaks when C-g is used in
+Emacs; also, malloc is slower and causes storage fragmentation.  On
+the other hand, malloc is more portable, and easier to debug.
+Because we sometimes use alloca, some routines have to be macros,
+not functions -- `alloca'-allocated space disappears at the end of the
+function it is called in.  */
+#ifdef REGEX_MALLOC
+#define REGEX_ALLOCATE malloc
+#define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
+#define REGEX_FREE free
+#else /* not REGEX_MALLOC  */
+/* Emacs already defines alloca, sometimes.  */
+#ifndef alloca
+/* Make alloca work the best possible way.  */
+#ifdef __GNUC__
+#define alloca __builtin_alloca
+#else /* not __GNUC__ */
+#if HAVE_ALLOCA_H
+#include <alloca.h>
+#else /* not __GNUC__ or HAVE_ALLOCA_H */
+#ifndef _AIX /* Already did AIX, up at the top.  */
+char *alloca ();
+#endif /* not _AIX */
+#endif /* not HAVE_ALLOCA_H */
+#endif /* not __GNUC__ */
+#endif /* not alloca */
+#define REGEX_ALLOCATE alloca
+/* Assumes a `char *destination' variable.  */
+#define REGEX_REALLOCATE(source, osize, nsize)				\
+(destination = (char *) alloca (nsize),				\
+memmove (destination, source, osize),				\
+destination)
+/* No need to do anything to free, after alloca.  */
+#define REGEX_FREE(arg) ((void)0) /* Do nothing!  But inhibit gcc warning.  */
+#endif /* not REGEX_MALLOC */
+/* Define how to allocate the failure stack.  */
+#ifdef REL_ALLOC
+#define REGEX_ALLOCATE_STACK(size)				\
+r_alloc ((char **) &failure_stack_ptr, (size))
+#define REGEX_REALLOCATE_STACK(source, osize, nsize)		\
+r_re_alloc ((char **) &failure_stack_ptr, (nsize))
+#define REGEX_FREE_STACK(ptr)					\
+r_alloc_free ((void **) &failure_stack_ptr)
+#else /* not REL_ALLOC */
+#ifdef REGEX_MALLOC
+#define REGEX_ALLOCATE_STACK malloc
+#define REGEX_REALLOCATE_STACK(source, osize, nsize) realloc (source, nsize)
+#define REGEX_FREE_STACK free
+#else /* not REGEX_MALLOC */
+#define REGEX_ALLOCATE_STACK alloca
+#define REGEX_REALLOCATE_STACK(source, osize, nsize)			\
+REGEX_REALLOCATE (source, osize, nsize)
+/* No need to explicitly free anything.  */
+#define REGEX_FREE_STACK(arg)
+#endif /* not REGEX_MALLOC */
+#endif /* not REL_ALLOC */
+/* True if `size1' is non-NULL and PTR is pointing anywhere inside
+`string1' or just past its end.  This works if PTR is NULL, which is
+a good thing.  */
+#define FIRST_STRING_P(ptr) 					\
+(size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
+/* (Re)Allocate N items of type T using malloc, or fail.  */
+#define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
+#define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
+#define RETALLOC_IF(addr, n, t) \
+if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
+#define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
+#define BYTEWIDTH 8 /* In bits.  */
+#define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
+#undef MAX
+#undef MIN
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+typedef char boolean;
+#define false 0
+#define true 1
+/* These are the command codes that appear in compiled regular
+expressions.  Some opcodes are followed by argument bytes.  A
+command code can specify any interpretation whatsoever for its
+arguments.  Zero bytes may appear in the compiled regular expression.  */
+typedef enum
+{
+no_op = 0,
+/* Succeed right away--no more backtracking.  */
+succeed,
+/* Followed by one byte giving n, then by n literal bytes.  */
+exactn,
+/* Matches any (more or less) character.  */
+anychar,
+/* Matches any one char belonging to specified set.  First
+following byte is number of bitmap bytes.  Then come bytes
+for a bitmap saying which chars are in.  Bits in each byte
+are ordered low-bit-first.  A character is in the set if its
+bit is 1.  A character too large to have a bit in the map is
+automatically not in the set.  */
+charset,
+/* Same parameters as charset, but match any character that is
+not one of those specified.  */
+charset_not,
+/* Start remembering the text that is matched, for storing in a
+register.  Followed by one byte with the register number, in
+the range 0 to one less than the pattern buffer's re_nsub
+field.  Then followed by one byte with the number of groups
+inner to this one.  (This last has to be part of the
+start_memory only because we need it in the on_failure_jump
+of re_match_2.)  */
+start_memory,
+/* Stop remembering the text that is matched and store it in a
+memory register.  Followed by one byte with the register
+number, in the range 0 to one less than `re_nsub' in the
+pattern buffer, and one byte with the number of inner groups,
+just like `start_memory'.  (We need the number of inner
+groups here because we don't have any easy way of finding the
+corresponding start_memory when we're at a stop_memory.)  */
+stop_memory,
+/* Match a duplicate of something remembered. Followed by one
+byte containing the register number.  */
+duplicate,
+/* Fail unless at beginning of line.  */
+begline,
+/* Fail unless at end of line.  */
+endline,
+/* Succeeds if at beginning of buffer (if emacs) or at beginning
+of string to be matched (if not).  */
+begbuf,
+/* Analogously, for end of buffer/string.  */
+endbuf,
+/* Followed by two byte relative address to which to jump.  */
+jump,
+	/* Same as jump, but marks the end of an alternative.  */
+jump_past_alt,
+/* Followed by two-byte relative address of place to resume at
+in case of failure.  */
+on_failure_jump,
+/* Like on_failure_jump, but pushes a placeholder instead of the
+current string position when executed.  */
+on_failure_keep_string_jump,
+/* Throw away latest failure point and then jump to following
+two-byte relative address.  */
+pop_failure_jump,
+/* Change to pop_failure_jump if know won't have to backtrack to
+match; otherwise change to jump.  This is used to jump
+back to the beginning of a repeat.  If what follows this jump
+clearly won't match what the repeat does, such that we can be
+sure that there is no use backtracking out of repetitions
+already matched, then we change it to a pop_failure_jump.
+Followed by two-byte address.  */
+maybe_pop_jump,
+/* Jump to following two-byte address, and push a dummy failure
+point. This failure point will be thrown away if an attempt
+is made to use it for a failure.  A `+' construct makes this
+before the first repeat.  Also used as an intermediary kind
+of jump when compiling an alternative.  */
+dummy_failure_jump,
+	/* Push a dummy failure point and continue.  Used at the end of
+	   alternatives.  */
+push_dummy_failure,
+/* Followed by two-byte relative address and two-byte number n.
+After matching N times, jump to the address upon failure.  */
+succeed_n,
+/* Followed by two-byte relative address, and two-byte number n.
+Jump to the address N times, then fail.  */
+jump_n,
+/* Set the following two-byte relative address to the
+subsequent two-byte number.  The address *includes* the two
+bytes of number.  */
+set_number_at,
+wordchar,	/* Matches any word-constituent character.  */
+notwordchar,	/* Matches any char that is not a word-constituent.  */
+wordbeg,	/* Succeeds if at word beginning.  */
+wordend,	/* Succeeds if at word end.  */
+wordbound,	/* Succeeds if at a word boundary.  */
+notwordbound	/* Succeeds if not at a word boundary.  */
+#ifdef emacs
+,before_dot,	/* Succeeds if before point.  */
+at_dot,	/* Succeeds if at point.  */
+after_dot,	/* Succeeds if after point.  */
+	/* Matches any character whose syntax is specified.  Followed by
+a byte which contains a syntax code, e.g., Sword.  */
+syntaxspec,
+	/* Matches any character whose syntax is not that specified.  */
+notsyntaxspec
+#endif /* emacs */
+} re_opcode_t;
+/* Common operations on the compiled pattern.  */
+/* Store NUMBER in two contiguous bytes starting at DESTINATION.  */
+#define STORE_NUMBER(destination, number)				\
+do {									\
+(destination)[0] = (number) & 0377;					\
+(destination)[1] = (number) >> 8;					\
+} while (0)
+/* Same as STORE_NUMBER, except increment DESTINATION to
+the byte after where the number is stored.  Therefore, DESTINATION
+must be an lvalue.  */
+#define STORE_NUMBER_AND_INCR(destination, number)			\
+do {									\
+STORE_NUMBER (destination, number);					\
+(destination) += 2;							\
+} while (0)
+/* Put into DESTINATION a number stored in two contiguous bytes starting
+at SOURCE.  */
+#define EXTRACT_NUMBER(destination, source)				\
+do {									\
+(destination) = *(source) & 0377;					\
+(destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8;		\
+} while (0)
+#ifdef DEBUG
+static void
+extract_number (int *dest, unsigned char *source)
+{
+int temp = SIGN_EXTEND_CHAR (*(source + 1));
+*dest = *source & 0377;
+*dest += temp << 8;
+}
+#ifndef EXTRACT_MACROS /* To debug the macros.  */
+#undef EXTRACT_NUMBER
+#define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
+#endif /* not EXTRACT_MACROS */
+#endif /* DEBUG */
+/* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
+SOURCE must be an lvalue.  */
+#define EXTRACT_NUMBER_AND_INCR(destination, source)			\
+do {									\
+EXTRACT_NUMBER (destination, source);				\
+(source) += 2; 							\
+} while (0)
+#ifdef DEBUG
+static void
+extract_number_and_incr (int *destination, unsigned char **source)
+{
+extract_number (destination, *source);
+*source += 2;
+}
+#ifndef EXTRACT_MACROS
+#undef EXTRACT_NUMBER_AND_INCR
+#define EXTRACT_NUMBER_AND_INCR(dest, src) \
+extract_number_and_incr (&dest, &src)
+#endif /* not EXTRACT_MACROS */
+#endif /* DEBUG */
+/* If DEBUG is defined, Regex prints many voluminous messages about what
+it is doing (if the variable `debug' is nonzero).  If linked with the
+main program in `iregex.c', you can enter patterns and strings
+interactively.  And if linked with the main program in `main.c' and
+the other test files, you can run the already-written tests.  */
+#if defined (DEBUG)
+/* We use standard I/O for debugging.  */
+#include <stdio.h>
+#ifndef emacs
+/* XEmacs provides its own version of assert() */
+/* It is useful to test things that ``must'' be true when debugging.  */
+#include <assert.h>
+#endif
+static int debug = 0;
+#define DEBUG_STATEMENT(e) e
+#define DEBUG_PRINT1(x) if (debug) printf (x)
+#define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
+#define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
+#define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
+#define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) 				\
+if (debug) print_partial_compiled_pattern (s, e)
+#define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)			\
+if (debug) print_double_string (w, s1, sz1, s2, sz2)
+/* Print the fastmap in human-readable form.  */
+static void
+print_fastmap (char *fastmap)
+{
+unsigned was_a_range = 0;
+unsigned i = 0;
+while (i < (1 << BYTEWIDTH))
+{
+if (fastmap[i++])
+	{
+	  was_a_range = 0;
+putchar (i - 1);
+while (i < (1 << BYTEWIDTH)  &&  fastmap[i])
+{
+was_a_range = 1;
+i++;
+}
+	  if (was_a_range)
+{
+printf ("-");
+putchar (i - 1);
+}
+}
+}
+putchar ('\n');
+}
+/* Print a compiled pattern string in human-readable form, starting at
+the START pointer into it and ending just before the pointer END.  */
+static void
+print_partial_compiled_pattern (unsigned char *start, unsigned char *end)
+{
+int mcnt, mcnt2;
+unsigned char *p = start;
+unsigned char *pend = end;
+if (start == NULL)
+{
+printf ("(null)\n");
+return;
+}
+/* Loop over pattern commands.  */
+while (p < pend)
+{
+printf ("%d:\t", p - start);
+switch ((re_opcode_t) *p++)
+	{
+case no_op:
+printf ("/no_op");
+break;
+	case exactn:
+	  mcnt = *p++;
+printf ("/exactn/%d", mcnt);
+do
+	    {
+putchar ('/');
+	      putchar (*p++);
+}
+while (--mcnt);
+break;
+	case start_memory:
+mcnt = *p++;
+printf ("/start_memory/%d/%d", mcnt, *p++);
+break;
+	case stop_memory:
+mcnt = *p++;
+	  printf ("/stop_memory/%d/%d", mcnt, *p++);
+break;
+	case duplicate:
+	  printf ("/duplicate/%d", *p++);
+	  break;
+	case anychar:
+	  printf ("/anychar");
+	  break;
+	case charset:
+case charset_not:
+{
+register int c, last = -100;
+	    register int in_range = 0;
+	    printf ("/charset [%s",
+	            (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
+assert (p + *p < pend);
+for (c = 0; c < 256; c++)
+	      if (((unsigned char) (c / 8) < *p)
+		  && (p[1 + (c/8)] & (1 << (c % 8))))
+		{
+		  /* Are we starting a range?  */
+		  if (last + 1 == c && ! in_range)
+		    {
+		      putchar ('-');
+		      in_range = 1;
+		    }
+		  /* Have we broken a range?  */
+		  else if (last + 1 != c && in_range)
+		    {
+		      putchar (last);
+		      in_range = 0;
+		    }
+		  if (! in_range)
+		    putchar (c);
+		  last = c;
+}
+	    if (in_range)
+	      putchar (last);
+	    putchar (']');
+	    p += 1 + *p;
+	  }
+	  break;
+	case begline:
+	  printf ("/begline");
+break;
+	case endline:
+printf ("/endline");
+break;
+	case on_failure_jump:
+extract_number_and_incr (&mcnt, &p);
+	  printf ("/on_failure_jump to %d", p + mcnt - start);
+break;
+	case on_failure_keep_string_jump:
+extract_number_and_incr (&mcnt, &p);
+	  printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
+break;
+	case dummy_failure_jump:
+extract_number_and_incr (&mcnt, &p);
+	  printf ("/dummy_failure_jump to %d", p + mcnt - start);
+break;
+	case push_dummy_failure:
+printf ("/push_dummy_failure");
+break;
+case maybe_pop_jump:
+extract_number_and_incr (&mcnt, &p);
+	  printf ("/maybe_pop_jump to %d", p + mcnt - start);
+	  break;
+case pop_failure_jump:
+	  extract_number_and_incr (&mcnt, &p);
+	  printf ("/pop_failure_jump to %d", p + mcnt - start);
+	  break;
+case jump_past_alt:
+	  extract_number_and_incr (&mcnt, &p);
+	  printf ("/jump_past_alt to %d", p + mcnt - start);
+	  break;
+case jump:
+	  extract_number_and_incr (&mcnt, &p);
+	  printf ("/jump to %d", p + mcnt - start);
+	  break;
+case succeed_n:
+extract_number_and_incr (&mcnt, &p);
+extract_number_and_incr (&mcnt2, &p);
+	  printf ("/succeed_n to %d, %d times", p + mcnt - start, mcnt2);
+break;
+case jump_n:
+extract_number_and_incr (&mcnt, &p);
+extract_number_and_incr (&mcnt2, &p);
+	  printf ("/jump_n to %d, %d times", p + mcnt - start, mcnt2);
+break;
+case set_number_at:
+extract_number_and_incr (&mcnt, &p);
+extract_number_and_incr (&mcnt2, &p);
+	  printf ("/set_number_at location %d to %d", p + mcnt - start, mcnt2);
+break;
+case wordbound:
+	  printf ("/wordbound");
+	  break;
+	case notwordbound:
+	  printf ("/notwordbound");
+break;
+	case wordbeg:
+	  printf ("/wordbeg");
+	  break;
+	case wordend:
+	  printf ("/wordend");
+#ifdef emacs
+	case before_dot:
+	  printf ("/before_dot");
+break;
+	case at_dot:
+	  printf ("/at_dot");
+break;
+	case after_dot:
+	  printf ("/after_dot");
+break;
+	case syntaxspec:
+printf ("/syntaxspec");
+	  mcnt = *p++;
+	  printf ("/%d", mcnt);
+break;
+	case notsyntaxspec:
+printf ("/notsyntaxspec");
+	  mcnt = *p++;
+	  printf ("/%d", mcnt);
+	  break;
+#endif /* emacs */
+	case wordchar:
+	  printf ("/wordchar");
+break;
+	case notwordchar:
+	  printf ("/notwordchar");
+break;
+	case begbuf:
+	  printf ("/begbuf");
+break;
+	case endbuf:
+	  printf ("/endbuf");
+break;
+default:
+printf ("?%d", *(p-1));
+	}
+putchar ('\n');
+}
+printf ("%d:\tend of pattern.\n", p - start);
+}
+static void
+print_compiled_pattern (struct re_pattern_buffer *bufp)
+{
+unsigned char *buffer = bufp->buffer;
+print_partial_compiled_pattern (buffer, buffer + bufp->used);
+printf ("%ld bytes used/%ld bytes allocated.\n", bufp->used,
+	  bufp->allocated);
+if (bufp->fastmap_accurate && bufp->fastmap)
+{
+printf ("fastmap: ");
+print_fastmap (bufp->fastmap);
+}
+printf ("re_nsub: %ld\t", (long)bufp->re_nsub);
+printf ("regs_alloc: %d\t", bufp->regs_allocated);
+printf ("can_be_null: %d\t", bufp->can_be_null);
+printf ("newline_anchor: %d\n", bufp->newline_anchor);
+printf ("no_sub: %d\t", bufp->no_sub);
+printf ("not_bol: %d\t", bufp->not_bol);
+printf ("not_eol: %d\t", bufp->not_eol);
+printf ("syntax: %d\n", bufp->syntax);
+/* Perhaps we should print the translate table?  */
+}
+static void
+print_double_string (CONST char *where, CONST char *string1, int size1,
+		     CONST char *string2, int size2)
+{
+unsigned this_char;
+if (where == NULL)
+printf ("(null)");
+else
+{
+if (FIRST_STRING_P (where))
+{
+for (this_char = where - string1; this_char < size1; this_char++)
+putchar (string1[this_char]);
+where = string2;
+}
+for (this_char = where - string2; this_char < size2; this_char++)
+putchar (string2[this_char]);
+}
+}
+#else /* not DEBUG */
+#undef assert
+#define assert(e)
+#define DEBUG_STATEMENT(e)
+#define DEBUG_PRINT1(x)
+#define DEBUG_PRINT2(x1, x2)
+#define DEBUG_PRINT3(x1, x2, x3)
+#define DEBUG_PRINT4(x1, x2, x3, x4)
+#define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
+#define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
+#endif /* not DEBUG */
+/* Set by `re_set_syntax' to the current regexp syntax to recognize.  Can
+also be assigned to arbitrarily: each pattern buffer stores its own
+syntax, so it can be changed between regex compilations.  */
+/* This has no initializer because initialized variables in Emacs
+become read-only after dumping.  */
+reg_syntax_t re_syntax_options;
+/* Specify the precise syntax of regexps for compilation.  This provides
+for compatibility for various utilities which historically have
+different, incompatible syntaxes.
+The argument SYNTAX is a bit mask comprised of the various bits
+defined in regex.h.  We return the old syntax.  */
+reg_syntax_t
+re_set_syntax (reg_syntax_t syntax)
+{
+reg_syntax_t ret = re_syntax_options;
+re_syntax_options = syntax;
+return ret;
+}
+/* This table gives an error message for each of the error codes listed
+in regex.h.  Obviously the order here has to be same as there.
+POSIX doesn't require that we do anything for REG_NOERROR,
+but why not be nice?  */
+static CONST char *re_error_msgid[] =
+{ "Success",					/* REG_NOERROR */
+"No match",					/* REG_NOMATCH */
+"Invalid regular expression",		/* REG_BADPAT */
+"Invalid collation character",		/* REG_ECOLLATE */
+"Invalid character class name",		/* REG_ECTYPE */
+"Trailing backslash",			/* REG_EESCAPE */
+"Invalid back reference",			/* REG_ESUBREG */
+"Unmatched [ or [^",			/* REG_EBRACK */
+"Unmatched ( or \\(",			/* REG_EPAREN */
+"Unmatched \\{",				/* REG_EBRACE */
+"Invalid content of \\{\\}",		/* REG_BADBR */
+"Invalid range end",			/* REG_ERANGE */
+"Memory exhausted",				/* REG_ESPACE */
+"Invalid preceding regular expression",	/* REG_BADRPT */
+"Premature end of regular expression",	/* REG_EEND */
+"Regular expression too big",		/* REG_ESIZE */
+"Unmatched ) or \\)",			/* REG_ERPAREN */
+#ifdef emacs
+"Invalid syntax designator",		/* REG_ESYNTAX */
+#endif
+};
+/* Avoiding alloca during matching, to placate r_alloc.  */
+/* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
+searching and matching functions should not call alloca.  On some
+systems, alloca is implemented in terms of malloc, and if we're
+using the relocating allocator routines, then malloc could cause a
+relocation, which might (if the strings being searched are in the
+ralloc heap) shift the data out from underneath the regexp
+routines.
+Here's another reason to avoid allocation: Emacs
+processes input from X in a signal handler; processing X input may
+call malloc; if input arrives while a matching routine is calling
+malloc, then we're scrod.  But Emacs can't just block input while
+calling matching routines; then we don't notice interrupts when
+they come in.  So, Emacs blocks input around all regexp calls
+except the matching calls, which it leaves unprotected, in the
+faith that they will not malloc.  */
+/* Normally, this is fine.  */
+#define MATCH_MAY_ALLOCATE
+/* When using GNU C, we are not REALLY using the C alloca, no matter
+what config.h may say.  So don't take precautions for it.  */
+#ifdef __GNUC__
+#undef C_ALLOCA
+#endif
+/* The match routines may not allocate if (1) they would do it with malloc
+and (2) it's not safe for them to use malloc.
+Note that if REL_ALLOC is defined, matching would not use malloc for the
+failure stack, but we would still use it for the register vectors;
+so REL_ALLOC should not affect this.  */
+#if (defined (C_ALLOCA) || defined (REGEX_MALLOC)) && defined (emacs)
+#undef MATCH_MAY_ALLOCATE
+#endif
+/* Failure stack declarations and macros; both re_compile_fastmap and
+re_match_2 use a failure stack.  These have to be macros because of
+REGEX_ALLOCATE_STACK.  */
+/* Number of failure points for which to initially allocate space
+when matching.  If this number is exceeded, we allocate more
+space, so it is not a hard limit.  */
+#ifndef INIT_FAILURE_ALLOC
+#define INIT_FAILURE_ALLOC 5
+#endif
+/* Roughly the maximum number of failure points on the stack.  Would be
+exactly that if always used MAX_FAILURE_SPACE each time we failed.
+This is a variable only so users of regex can assign to it; we never
+change it ourselves.  */
+#if defined (MATCH_MAY_ALLOCATE)
+int re_max_failures = 200000;
+#else
+int re_max_failures = 2000;
+#endif
+union fail_stack_elt
+{
+unsigned char *pointer;
+int integer;
+};
+typedef union fail_stack_elt fail_stack_elt_t;
+typedef struct
+{
+fail_stack_elt_t *stack;
+unsigned size;
+unsigned avail;			/* Offset of next open position.  */
+} fail_stack_type;
+#define FAIL_STACK_EMPTY()     (fail_stack.avail == 0)
+#define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
+#define FAIL_STACK_FULL()      (fail_stack.avail == fail_stack.size)
+/* Define macros to initialize and free the failure stack.
+Do `return -2' if the alloc fails.  */
+#ifdef MATCH_MAY_ALLOCATE
+#define INIT_FAIL_STACK()						\
+do {									\
+fail_stack.stack = (fail_stack_elt_t *)				\
+REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t));	\
+									\
+if (fail_stack.stack == NULL)					\
+return -2;							\
+									\
+fail_stack.size = INIT_FAILURE_ALLOC;				\
+fail_stack.avail = 0;						\
+} while (0)
+#define RESET_FAIL_STACK()  REGEX_FREE_STACK (fail_stack.stack)
+#else
+#define INIT_FAIL_STACK()						\
+do {									\
+fail_stack.avail = 0;						\
+} while (0)
+#define RESET_FAIL_STACK()
+#endif
+/* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
+Return 1 if succeeds, and 0 if either ran out of memory
+allocating space for it or it was already too large.
+REGEX_REALLOCATE_STACK requires `destination' be declared.   */
+#define DOUBLE_FAIL_STACK(fail_stack)					\
+((fail_stack).size > re_max_failures * MAX_FAILURE_ITEMS		\
+? 0									\
+: ((fail_stack).stack = (fail_stack_elt_t *)				\
+REGEX_REALLOCATE_STACK ((fail_stack).stack, 			\
+(fail_stack).size * sizeof (fail_stack_elt_t),		\
+((fail_stack).size << 1) * sizeof (fail_stack_elt_t)),	\
+									\
+(fail_stack).stack == NULL					\
+? 0								\
+: ((fail_stack).size <<= 1, 					\
+1)))
+/* Push pointer POINTER on FAIL_STACK.
+Return 1 if was able to do so and 0 if ran out of memory allocating
+space to do so.  */
+#define PUSH_PATTERN_OP(POINTER, FAIL_STACK)				\
+((FAIL_STACK_FULL ()							\
+&& !DOUBLE_FAIL_STACK (FAIL_STACK))					\
+? 0									\
+: ((FAIL_STACK).stack[(FAIL_STACK).avail++].pointer = POINTER,	\
+1))
+/* Push a pointer value onto the failure stack.
+Assumes the variable `fail_stack'.  Probably should only
+be called from within `PUSH_FAILURE_POINT'.  */
+#define PUSH_FAILURE_POINTER(item)					\
+fail_stack.stack[fail_stack.avail++].pointer = (unsigned char *) (item)
+/* This pushes an integer-valued item onto the failure stack.
+Assumes the variable `fail_stack'.  Probably should only
+be called from within `PUSH_FAILURE_POINT'.  */
+#define PUSH_FAILURE_INT(item)					\
+fail_stack.stack[fail_stack.avail++].integer = (item)
+/* Push a fail_stack_elt_t value onto the failure stack.
+Assumes the variable `fail_stack'.  Probably should only
+be called from within `PUSH_FAILURE_POINT'.  */
+#define PUSH_FAILURE_ELT(item)					\
+fail_stack.stack[fail_stack.avail++] =  (item)
+/* These three POP... operations complement the three PUSH... operations.
+All assume that `fail_stack' is nonempty.  */
+#define POP_FAILURE_POINTER() fail_stack.stack[--fail_stack.avail].pointer
+#define POP_FAILURE_INT() fail_stack.stack[--fail_stack.avail].integer
+#define POP_FAILURE_ELT() fail_stack.stack[--fail_stack.avail]
+/* Used to omit pushing failure point id's when we're not debugging.  */
+#ifdef DEBUG
+#define DEBUG_PUSH PUSH_FAILURE_INT
+#define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_INT ()
+#else
+#define DEBUG_PUSH(item)
+#define DEBUG_POP(item_addr)
+#endif
+/* Push the information about the state we will need
+if we ever fail back to it.
+Requires variables fail_stack, regstart, regend, reg_info, and
+num_regs be declared.  DOUBLE_FAIL_STACK requires `destination' be
+declared.
+Does `return FAILURE_CODE' if runs out of memory.  */
+#if !defined (REGEX_MALLOC) && !defined (REL_ALLOC)
+#define DECLARE_DESTINATION char *destination;
+#else
+#define DECLARE_DESTINATION
+#endif
+#define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code)	\
+do {									\
+DECLARE_DESTINATION							\
+/* Must be int, so when we don't save any registers, the arithmetic	\
+of 0 + -1 isn't done as unsigned.  */				\
+int this_reg;							\
+									\
+DEBUG_STATEMENT (failure_id++);					\
+DEBUG_STATEMENT (nfailure_points_pushed++);				\
+DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id);		\
+DEBUG_PRINT2 ("  Before push, next avail: %d\n", (fail_stack).avail);\
+DEBUG_PRINT2 ("                     size: %d\n", (fail_stack).size);\
+									\
+DEBUG_PRINT2 ("  slots needed: %d\n", NUM_FAILURE_ITEMS);		\
+DEBUG_PRINT2 ("     available: %d\n", REMAINING_AVAIL_SLOTS);	\
+									\
+/* Ensure we have enough space allocated for what we will push.  */	\
+while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS)			\
+{									\
+if (!DOUBLE_FAIL_STACK (fail_stack))				\
+return failure_code;						\
+									\
+DEBUG_PRINT2 ("\n  Doubled stack; size now: %d\n",		\
+		       (fail_stack).size);				\
+DEBUG_PRINT2 ("  slots available: %d\n", REMAINING_AVAIL_SLOTS);\
+}									\
+									\
+/* Push the info, starting with the registers.  */			\
+DEBUG_PRINT1 ("\n");						\
+									\
+for (this_reg = lowest_active_reg; this_reg <= highest_active_reg;	\
+this_reg++)							\
+{									\
+	DEBUG_PRINT2 ("  Pushing reg: %d\n", this_reg);			\
+DEBUG_STATEMENT (num_regs_pushed++);				\
+									\
+	DEBUG_PRINT2 ("    start: 0x%lx\n",				\
+		      (unsigned long) regstart[this_reg]);		\
+PUSH_FAILURE_POINTER (regstart[this_reg]);			\
+\
+	DEBUG_PRINT2 ("    end: 0x%lx\n",				\
+		      (unsigned long) regend[this_reg]);		\
+PUSH_FAILURE_POINTER (regend[this_reg]);			\
+									\
+	DEBUG_PRINT2 ("    info: 0x%lx\n      ",			\
+		      * (unsigned long *) (&reg_info[this_reg]));	\
+DEBUG_PRINT2 (" match_null=%d",					\
+REG_MATCH_NULL_STRING_P (reg_info[this_reg]));	\
+DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg]));	\
+DEBUG_PRINT2 (" matched_something=%d",				\
+MATCHED_SOMETHING (reg_info[this_reg]));		\
+DEBUG_PRINT2 (" ever_matched=%d",				\
+EVER_MATCHED_SOMETHING (reg_info[this_reg]));	\
+	DEBUG_PRINT1 ("\n");						\
+PUSH_FAILURE_ELT (reg_info[this_reg].word);			\
+}									\
+									\
+DEBUG_PRINT2 ("  Pushing  low active reg: %d\n", lowest_active_reg);\
+PUSH_FAILURE_INT (lowest_active_reg);				\
+									\
+DEBUG_PRINT2 ("  Pushing high active reg: %d\n", highest_active_reg);\
+PUSH_FAILURE_INT (highest_active_reg);				\
+									\
+DEBUG_PRINT2 ("  Pushing pattern 0x%lx: ",				\
+		  (unsigned long) pattern_place);			\
+DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend);		\
+PUSH_FAILURE_POINTER (pattern_place);				\
+									\
+DEBUG_PRINT2 ("  Pushing string 0x%lx: `",				\
+		  (unsigned long) string_place);			\
+DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2,   \
+				 size2);				\
+DEBUG_PRINT1 ("'\n");						\
+PUSH_FAILURE_POINTER (string_place);				\
+									\
+DEBUG_PRINT2 ("  Pushing failure id: %u\n", failure_id);		\
+DEBUG_PUSH (failure_id);						\
+} while (0)
+/* This is the number of items that are pushed and popped on the stack
+for each register.  */
+#define NUM_REG_ITEMS  3
+/* Individual items aside from the registers.  */
+#ifdef DEBUG
+#define NUM_NONREG_ITEMS 5 /* Includes failure point id.  */
+#else
+#define NUM_NONREG_ITEMS 4
+#endif
+/* We push at most this many items on the stack.  */
+#define MAX_FAILURE_ITEMS ((num_regs - 1) * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
+/* We actually push this many items.  */
+#define NUM_FAILURE_ITEMS						\
+((highest_active_reg - lowest_active_reg + 1) * NUM_REG_ITEMS 	\
++ NUM_NONREG_ITEMS)
+/* How many items can still be added to the stack without overflowing it.  */
+#define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
+/* Pops what PUSH_FAIL_STACK pushes.
+We restore into the parameters, all of which should be lvalues:
+STR -- the saved data position.
+PAT -- the saved pattern position.
+LOW_REG, HIGH_REG -- the highest and lowest active registers.
+REGSTART, REGEND -- arrays of string positions.
+REG_INFO -- array of information about each subexpression.
+Also assumes the variables `fail_stack' and (if debugging), `bufp',
+`pend', `string1', `size1', `string2', and `size2'.  */
+#define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
+{									\
+DEBUG_STATEMENT (fail_stack_elt_t ffailure_id;)			\
+int this_reg;								\
+CONST unsigned char *string_temp;					\
+									\
+assert (!FAIL_STACK_EMPTY ());					\
+									\
+/* Remove failure points and point to how many regs pushed.  */	\
+DEBUG_PRINT1 ("POP_FAILURE_POINT:\n");				\
+DEBUG_PRINT2 ("  Before pop, next avail: %d\n", fail_stack.avail);	\
+DEBUG_PRINT2 ("                    size: %d\n", fail_stack.size);	\
+									\
+assert (fail_stack.avail >= NUM_NONREG_ITEMS);			\
+									\
+DEBUG_POP (&ffailure_id.integer);					\
+DEBUG_PRINT2 ("  Popping failure id: %u\n",				\
+		* (unsigned int *) &ffailure_id);			\
+									\
+/* If the saved string location is NULL, it came from an		\
+on_failure_keep_string_jump opcode, and we want to throw away the	\
+saved NULL, thus retaining our current position in the string.  */	\
+string_temp = POP_FAILURE_POINTER ();					\
+if (string_temp != NULL)						\
+str = (CONST char *) string_temp;					\
+									\
+DEBUG_PRINT2 ("  Popping string 0x%lx: `", (unsigned long) str);	\
+DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2);	\
+DEBUG_PRINT1 ("'\n");							\
+									\
+pat = (unsigned char *) POP_FAILURE_POINTER ();			\
+DEBUG_PRINT2 ("  Popping pattern 0x%lx: ", (unsigned long) pat);	\
+DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend);			\
+									\
+/* Restore register info.  */						\
+high_reg = (unsigned) POP_FAILURE_INT ();				\
+DEBUG_PRINT2 ("  Popping high active reg: %d\n", high_reg);		\
+									\
+low_reg = (unsigned) POP_FAILURE_INT ();				\
+DEBUG_PRINT2 ("  Popping  low active reg: %d\n", low_reg);		\
+									\
+for (this_reg = high_reg; this_reg >= low_reg; this_reg--)		\
+{									\
+DEBUG_PRINT2 ("    Popping reg: %d\n", this_reg);			\
+									\
+reg_info[this_reg].word = POP_FAILURE_ELT ();			\
+DEBUG_PRINT2 ("      info: 0x%lx\n",				\
+		    * (unsigned long *) &reg_info[this_reg]);		\
+									\
+regend[this_reg] = (CONST char *) POP_FAILURE_POINTER ();		\
+DEBUG_PRINT2 ("      end: 0x%lx\n",				\
+		    (unsigned long) regend[this_reg]);			\
+									\
+regstart[this_reg] = (CONST char *) POP_FAILURE_POINTER ();	\
+DEBUG_PRINT2 ("      start: 0x%lx\n",				\
+		    (unsigned long) regstart[this_reg]);		\
+}									\
+									\
+set_regs_matched_done = 0;						\
+DEBUG_STATEMENT (nfailure_points_popped++);				\
+} /* POP_FAILURE_POINT */
+/* Structure for per-register (a.k.a. per-group) information.
+Other register information, such as the
+starting and ending positions (which are addresses), and the list of
+inner groups (which is a bits list) are maintained in separate
+variables.
+We are making a (strictly speaking) nonportable assumption here: that
+the compiler will pack our bit fields into something that fits into
+the type of `word', i.e., is something that fits into one item on the
+failure stack.  */
+typedef union
+{
+fail_stack_elt_t word;
+struct
+{
+/* This field is one if this group can match the empty string,
+zero if not.  If not yet determined,  `MATCH_NULL_UNSET_VALUE'.  */
+#define MATCH_NULL_UNSET_VALUE 3
+unsigned match_null_string_p : 2;
+unsigned is_active : 1;
+unsigned matched_something : 1;
+unsigned ever_matched_something : 1;
+} bits;
+} register_info_type;
+#define REG_MATCH_NULL_STRING_P(R)  ((R).bits.match_null_string_p)
+#define IS_ACTIVE(R)  ((R).bits.is_active)
+#define MATCHED_SOMETHING(R)  ((R).bits.matched_something)
+#define EVER_MATCHED_SOMETHING(R)  ((R).bits.ever_matched_something)
+/* Call this when have matched a real character; it sets `matched' flags
+for the subexpressions which we are currently inside.  Also records
+that those subexprs have matched.  */
+#define SET_REGS_MATCHED()						\
+do									\
+{									\
+if (!set_regs_matched_done)					\
+	{								\
+	  unsigned r;							\
+	  set_regs_matched_done = 1;					\
+	  for (r = lowest_active_reg; r <= highest_active_reg; r++)	\
+	    {								\
+	      MATCHED_SOMETHING (reg_info[r])				\
+		= EVER_MATCHED_SOMETHING (reg_info[r])			\
+		= 1;							\
+	    }								\
+	}								\
+}									\
+while (0)
+/* Registers are set to a sentinel when they haven't yet matched.  */
+static char reg_unset_dummy;
+#define REG_UNSET_VALUE (&reg_unset_dummy)
+#define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
+/* Subroutine declarations and macros for regex_compile.  */
+/* Fetch the next character in the uncompiled pattern---translating it
+if necessary.  Also cast from a signed character in the constant
+string passed to us by the user to an unsigned char that we can use
+as an array index (in, e.g., `translate').  */
+#define PATFETCH(c)							\
+do {if (p == pend) return REG_EEND;					\
+assert (p < pend);							\
+c = (unsigned char) *p++;						\
+if (translate) c = (unsigned char) translate[c]; 			\
+} while (0)
+/* Fetch the next character in the uncompiled pattern, with no
+translation.  */
+#define PATFETCH_RAW(c)							\
+do {if (p == pend) return REG_EEND;					\
+assert (p < pend);							\
+c = (unsigned char) *p++; 						\
+} while (0)
+/* Go backwards one character in the pattern.  */
+#define PATUNFETCH p--
+#define PATFETCH_EITHER(emch) PATFETCH (emch)
+#define PATFETCH_RAW_EITHER(emch) PATFETCH_RAW (emch)
+#define PATUNFETCH_EITHER PATUNFETCH
+/* If `translate' is non-null, return translate[D], else just D.  We
+cast the subscript to translate because some data is declared as
+`char *', to avoid warnings when a string constant is passed.  But
+when we use a character as a subscript we must make it unsigned.  */
+#define TRANSLATE(d) (translate ? translate[(unsigned char) (d)] : (d))
+/* Macros for outputting the compiled pattern into `buffer'.  */
+/* If the buffer isn't allocated when it comes in, use this.  */
+#define INIT_BUF_SIZE  32
+/* Make sure we have at least N more bytes of space in buffer.  */
+#define GET_BUFFER_SPACE(n)						\
+while (b - bufp->buffer + (n) > bufp->allocated)			\
+EXTEND_BUFFER ()
+/* Make sure we have one more byte of buffer space and then add C to it.  */
+#define BUF_PUSH(c)							\
+do {									\
+GET_BUFFER_SPACE (1);						\
+*b++ = (unsigned char) (c);						\
+} while (0)
+/* Ensure we have two more bytes of buffer space and then append C1 and C2.  */
+#define BUF_PUSH_2(c1, c2)						\
+do {									\
+GET_BUFFER_SPACE (2);						\
+*b++ = (unsigned char) (c1);					\
+*b++ = (unsigned char) (c2);					\
+} while (0)
+/* As with BUF_PUSH_2, except for three bytes.  */
+#define BUF_PUSH_3(c1, c2, c3)						\
+do {									\
+GET_BUFFER_SPACE (3);						\
+*b++ = (unsigned char) (c1);					\
+*b++ = (unsigned char) (c2);					\
+*b++ = (unsigned char) (c3);					\
+} while (0)
+/* Store a jump with opcode OP at LOC to location TO.  We store a
+relative address offset by the three bytes the jump itself occupies.  */
+#define STORE_JUMP(op, loc, to) \
+store_op1 (op, loc, (to) - (loc) - 3)
+/* Likewise, for a two-argument jump.  */
+#define STORE_JUMP2(op, loc, to, arg) \
+store_op2 (op, loc, (to) - (loc) - 3, arg)
+/* Like `STORE_JUMP', but for inserting.  Assume `b' is the buffer end.  */
+#define INSERT_JUMP(op, loc, to) \
+insert_op1 (op, loc, (to) - (loc) - 3, b)
+/* Like `STORE_JUMP2', but for inserting.  Assume `b' is the buffer end.  */
+#define INSERT_JUMP2(op, loc, to, arg) \
+insert_op2 (op, loc, (to) - (loc) - 3, arg, b)
+/* This is not an arbitrary limit: the arguments which represent offsets
+into the pattern are two bytes long.  So if 2^16 bytes turns out to
+be too small, many things would have to change.  */
+#define MAX_BUF_SIZE (1L << 16)
+/* Extend the buffer by twice its current size via realloc and
+reset the pointers that pointed into the old block to point to the
+correct places in the new one.  If extending the buffer results in it
+being larger than MAX_BUF_SIZE, then flag memory exhausted.  */
+#define EXTEND_BUFFER()							\
+do { 									\
+unsigned char *old_buffer = bufp->buffer;				\
+if (bufp->allocated == MAX_BUF_SIZE) 				\
+return REG_ESIZE;							\
+bufp->allocated <<= 1;						\
+if (bufp->allocated > MAX_BUF_SIZE)					\
+bufp->allocated = MAX_BUF_SIZE; 					\
+bufp->buffer = (unsigned char *) realloc (bufp->buffer, bufp->allocated);\
+if (bufp->buffer == NULL)						\
+return REG_ESPACE;						\
+/* If the buffer moved, move all the pointers into it.  */		\
+if (old_buffer != bufp->buffer)					\
+{									\
+b = (b - old_buffer) + bufp->buffer;				\
+begalt = (begalt - old_buffer) + bufp->buffer;			\
+if (fixup_alt_jump)						\
+fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
+if (laststart)							\
+laststart = (laststart - old_buffer) + bufp->buffer;		\
+if (pending_exact)						\
+pending_exact = (pending_exact - old_buffer) + bufp->buffer;	\
+}									\
+} while (0)
+/* Since we have one byte reserved for the register number argument to
+{start,stop}_memory, the maximum number of groups we can report
+things about is what fits in that byte.  */
+#define MAX_REGNUM 255
+/* But patterns can have more than `MAX_REGNUM' registers.  We just
+ignore the excess.  */
+typedef unsigned regnum_t;
+/* Macros for the compile stack.  */
+/* Since offsets can go either forwards or backwards, this type needs to
+be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1.  */
+typedef int pattern_offset_t;
+typedef struct
+{
+pattern_offset_t begalt_offset;
+pattern_offset_t fixup_alt_jump;
+pattern_offset_t inner_group_offset;
+pattern_offset_t laststart_offset;
+regnum_t regnum;
+} compile_stack_elt_t;
+typedef struct
+{
+compile_stack_elt_t *stack;
+unsigned size;
+unsigned avail;			/* Offset of next open position.  */
+} compile_stack_type;
+#define INIT_COMPILE_STACK_SIZE 32
+#define COMPILE_STACK_EMPTY  (compile_stack.avail == 0)
+#define COMPILE_STACK_FULL  (compile_stack.avail == compile_stack.size)
+/* The next available element.  */
+#define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
+/* Set the bit for character C in a bit vector.  */
+#define SET_LIST_BIT(c)				\
+(b[((unsigned char) (c)) / BYTEWIDTH]		\
+|= 1 << (((unsigned char) c) % BYTEWIDTH))
+#define SET_EITHER_BIT(c) SET_LIST_BIT (c)
+/* Get the next unsigned number in the uncompiled pattern.  */
+#define GET_UNSIGNED_NUMBER(num) 					\
+{ if (p != pend)							\
+{									\
+PATFETCH (c); 							\
+while (ISDIGIT (c)) 						\
+{ 								\
+if (num < 0)							\
+num = 0;							\
+num = num * 10 + c - '0'; 					\
+if (p == pend) 						\
+break; 							\
+PATFETCH (c);						\
+} 								\
+} 								\
+}
+#define CHAR_CLASS_MAX_LENGTH  6 /* Namely, `xdigit'.  */
+#define IS_CHAR_CLASS(string)						\
+(STREQ (string, "alpha") || STREQ (string, "upper")			\
+|| STREQ (string, "lower") || STREQ (string, "digit")		\
+|| STREQ (string, "alnum") || STREQ (string, "xdigit")		\
+|| STREQ (string, "space") || STREQ (string, "print")		\
+|| STREQ (string, "punct") || STREQ (string, "graph")		\
+|| STREQ (string, "cntrl") || STREQ (string, "blank"))
+static void store_op1 (re_opcode_t op, unsigned char *loc, int arg);
+static void store_op2 (re_opcode_t op, unsigned char *loc, int arg1, int arg2);
+static void insert_op1 (re_opcode_t op, unsigned char *loc, int arg,
+			unsigned char *end);
+static void insert_op2 (re_opcode_t op, unsigned char *loc, int arg1, int arg2,
+			unsigned char *end);
+static boolean at_begline_loc_p (CONST char *pattern, CONST char *p,
+				 reg_syntax_t syntax);
+static boolean at_endline_loc_p (CONST char *p, CONST char *pend, int syntax);
+static boolean group_in_compile_stack (compile_stack_type compile_stack,
+				       regnum_t regnum);
+static reg_errcode_t compile_range (CONST char **p_ptr, CONST char *pend,
+				    char *translate, reg_syntax_t syntax,
+				    unsigned char *b);
+static boolean group_match_null_string_p (unsigned char **p,
+					  unsigned char *end,
+					  register_info_type *reg_info);
+static boolean alt_match_null_string_p (unsigned char *p, unsigned char *end,
+					register_info_type *reg_info);
+static boolean common_op_match_null_string_p (unsigned char **p,
+					      unsigned char *end,
+					      register_info_type *reg_info);
+static int bcmp_translate (CONST unsigned char *s1, CONST unsigned char *s2,
+			   register int len, char *translate);
+static int re_match_2_internal (struct re_pattern_buffer *bufp,
+				CONST char *string1, int size1,
+				CONST char *string2, int size2, int pos,
+				struct re_registers *regs, int stop);
+#ifndef MATCH_MAY_ALLOCATE
+/* If we cannot allocate large objects within re_match_2_internal,
+we make the fail stack and register vectors global.
+The fail stack, we grow to the maximum size when a regexp
+is compiled.
+The register vectors, we adjust in size each time we
+compile a regexp, according to the number of registers it needs.  */
+static fail_stack_type fail_stack;
+/* Size with which the following vectors are currently allocated.
+That is so we can make them bigger as needed,
+but never make them smaller.  */
+static int regs_allocated_size;
+static CONST char **     regstart, **     regend;
+static CONST char ** old_regstart, ** old_regend;
+static CONST char **best_regstart, **best_regend;
+static register_info_type *reg_info;
+static CONST char **reg_dummy;
+static register_info_type *reg_info_dummy;
+/* Make the register vectors big enough for NUM_REGS registers,
+but don't make them smaller.  */
+static
+regex_grow_registers (int num_regs)
+{
+if (num_regs > regs_allocated_size)
+{
+RETALLOC_IF (regstart,	 num_regs, CONST char *);
+RETALLOC_IF (regend,	 num_regs, CONST char *);
+RETALLOC_IF (old_regstart, num_regs, CONST char *);
+RETALLOC_IF (old_regend,	 num_regs, CONST char *);
+RETALLOC_IF (best_regstart, num_regs, CONST char *);
+RETALLOC_IF (best_regend,	 num_regs, CONST char *);
+RETALLOC_IF (reg_info,	 num_regs, register_info_type);
+RETALLOC_IF (reg_dummy,	 num_regs, CONST char *);
+RETALLOC_IF (reg_info_dummy, num_regs, register_info_type);
+regs_allocated_size = num_regs;
+}
+}
+#endif /* not MATCH_MAY_ALLOCATE */
+/* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
+Returns one of error codes defined in `regex.h', or zero for success.
+Assumes the `allocated' (and perhaps `buffer') and `translate'
+fields are set in BUFP on entry.
+If it succeeds, results are put in BUFP (if it returns an error, the
+contents of BUFP are undefined):
+`buffer' is the compiled pattern;
+`syntax' is set to SYNTAX;
+`used' is set to the length of the compiled pattern;
+`fastmap_accurate' is zero;
+`re_nsub' is the number of subexpressions in PATTERN;
+`not_bol' and `not_eol' are zero;
+The `fastmap' and `newline_anchor' fields are neither
+examined nor set.  */
+/* Return, freeing storage we allocated.  */
+#define FREE_STACK_RETURN(value)		\
+return (free (compile_stack.stack), value)
+static reg_errcode_t
+regex_compile (CONST char *pattern, int size, reg_syntax_t syntax,
+	       struct re_pattern_buffer *bufp)
+{
+/* We fetch characters from PATTERN here.  We declare these as int
+(or possibly long) so that chars above 127 can be used as
+array indices.  The macros that fetch a character from the pattern
+make sure to coerce to unsigned char before assigning, so we won't
+get bitten by negative numbers here. */
+/* XEmacs change: used to be unsigned char. */
+register EMACS_INT c, c1;
+/* A random temporary spot in PATTERN.  */
+CONST char *p1;
+/* Points to the end of the buffer, where we should append.  */
+register unsigned char *b;
+/* Keeps track of unclosed groups.  */
+compile_stack_type compile_stack;
+/* Points to the current (ending) position in the pattern.  */
+CONST char *p = pattern;
+CONST char *pend = pattern + size;
+/* How to translate the characters in the pattern.  */
+char *translate = bufp->translate;
+/* Address of the count-byte of the most recently inserted `exactn'
+command.  This makes it possible to tell if a new exact-match
+character can be added to that command or if the character requires
+a new `exactn' command.  */
+unsigned char *pending_exact = 0;
+/* Address of start of the most recently finished expression.
+This tells, e.g., postfix * where to find the start of its
+operand.  Reset at the beginning of groups and alternatives.  */
+unsigned char *laststart = 0;
+/* Address of beginning of regexp, or inside of last group.  */
+unsigned char *begalt;
+/* Place in the uncompiled pattern (i.e., the {) to
+which to go back if the interval is invalid.  */
+CONST char *beg_interval;
+/* Address of the place where a forward jump should go to the end of
+the containing expression.  Each alternative of an `or' -- except the
+last -- ends with a forward jump of this sort.  */
+unsigned char *fixup_alt_jump = 0;
+/* Counts open-groups as they are encountered.  Remembered for the
+matching close-group on the compile stack, so the same register
+number is put in the stop_memory as the start_memory.  */
+regnum_t regnum = 0;
+#ifdef DEBUG
+DEBUG_PRINT1 ("\nCompiling pattern: ");
+if (debug)
+{
+unsigned debug_count;
+for (debug_count = 0; debug_count < size; debug_count++)
+putchar (pattern[debug_count]);
+putchar ('\n');
+}
+#endif /* DEBUG */
+/* Initialize the compile stack.  */
+compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
+if (compile_stack.stack == NULL)
+return REG_ESPACE;
+compile_stack.size = INIT_COMPILE_STACK_SIZE;
+compile_stack.avail = 0;
+/* Initialize the pattern buffer.  */
+bufp->syntax = syntax;
+bufp->fastmap_accurate = 0;
+bufp->not_bol = bufp->not_eol = 0;
+/* Set `used' to zero, so that if we return an error, the pattern
+printer (for debugging) will think there's no pattern.  We reset it
+at the end.  */
+bufp->used = 0;
+/* Always count groups, whether or not bufp->no_sub is set.  */
+bufp->re_nsub = 0;
+#if !defined (emacs) && !defined (SYNTAX_TABLE)
+/* Initialize the syntax table.  */
+init_syntax_once ();
+#endif
+if (bufp->allocated == 0)
+{
+if (bufp->buffer)
+	{ /* If zero allocated, but buffer is non-null, try to realloc
+enough space.  This loses if buffer's address is bogus, but
+that is the user's responsibility.  */
+RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
+}
+else
+{ /* Caller did not allocate a buffer.  Do it for them.  */
+bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
+}
+if (!bufp->buffer) FREE_STACK_RETURN (REG_ESPACE);
+bufp->allocated = INIT_BUF_SIZE;
+}
+begalt = b = bufp->buffer;
+/* Loop through the uncompiled pattern until we're at the end.  */
+while (p != pend)
+{
+PATFETCH (c);
+switch (c)
+{
+case '^':
+{
+if (   /* If at start of pattern, it's an operator.  */
+p == pattern + 1
+/* If context independent, it's an operator.  */
+|| syntax & RE_CONTEXT_INDEP_ANCHORS
+/* Otherwise, depends on what's come before.  */
+|| at_begline_loc_p (pattern, p, syntax))
+BUF_PUSH (begline);
+else
+goto normal_char;
+}
+break;
+case '$':
+{
+if (   /* If at end of pattern, it's an operator.  */
+p == pend
+/* If context independent, it's an operator.  */
+|| syntax & RE_CONTEXT_INDEP_ANCHORS
+/* Otherwise, depends on what's next.  */
+|| at_endline_loc_p (p, pend, syntax))
+BUF_PUSH (endline);
+else
+goto normal_char;
+}
+break;
+	case '+':
+case '?':
+if ((syntax & RE_BK_PLUS_QM)
+|| (syntax & RE_LIMITED_OPS))
+goto normal_char;
+handle_plus:
+case '*':
+/* If there is no previous pattern... */
+if (!laststart)
+{
+if (syntax & RE_CONTEXT_INVALID_OPS)
+FREE_STACK_RETURN (REG_BADRPT);
+else if (!(syntax & RE_CONTEXT_INDEP_OPS))
+goto normal_char;
+}
+{
+/* Are we optimizing this jump?  */
+boolean keep_string_p = false;
+/* 1 means zero (many) matches is allowed.  */
+char zero_times_ok = 0, many_times_ok = 0;
+/* If there is a sequence of repetition chars, collapse it
+down to just one (the right one).  We can't combine
+interval operators with these because of, e.g., `a{2}*',
+which should only match an even number of `a's.  */
+for (;;)
+{
+zero_times_ok |= c != '+';
+many_times_ok |= c != '?';
+if (p == pend)
+break;
+PATFETCH (c);
+if (c == '*'
+|| (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
+;
+else if (syntax & RE_BK_PLUS_QM  &&  c == '\\')
+{
+if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
+PATFETCH (c1);
+if (!(c1 == '+' || c1 == '?'))
+{
+PATUNFETCH;
+PATUNFETCH;
+break;
+}
+c = c1;
+}
+else
+{
+PATUNFETCH;
+break;
+}
+/* If we get here, we found another repeat character.  */
+}
+/* Star, etc. applied to an empty pattern is equivalent
+to an empty pattern.  */
+if (!laststart)
+break;
+/* Now we know whether or not zero matches is allowed
+and also whether or not two or more matches is allowed.  */
+if (many_times_ok)
+{ /* More than one repetition is allowed, so put in at the
+end a backward relative jump from `b' to before the next
+jump we're going to put in below (which jumps from
+laststart to after this jump).
+But if we are at the `*' in the exact sequence `.*\n',
+insert an unconditional jump backwards to the .,
+instead of the beginning of the loop.  This way we only
+push a failure point once, instead of every time
+through the loop.  */
+assert (p - 1 > pattern);
+/* Allocate the space for the jump.  */
+GET_BUFFER_SPACE (3);
+/* We know we are not at the first character of the pattern,
+because laststart was nonzero.  And we've already
+incremented `p', by the way, to be the character after
+the `*'.  Do we have to do something analogous here
+for null bytes, because of RE_DOT_NOT_NULL?  */
+if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
+		    && zero_times_ok
+&& p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
+&& !(syntax & RE_DOT_NEWLINE))
+{ /* We have .*\n.  */
+STORE_JUMP (jump, b, laststart);
+keep_string_p = true;
+}
+else
+/* Anything else.  */
+STORE_JUMP (maybe_pop_jump, b, laststart - 3);
+/* We've added more stuff to the buffer.  */
+b += 3;
+}
+/* On failure, jump from laststart to b + 3, which will be the
+end of the buffer after this jump is inserted.  */
+GET_BUFFER_SPACE (3);
+INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
+: on_failure_jump,
+laststart, b + 3);
+pending_exact = 0;
+b += 3;
+if (!zero_times_ok)
+{
+/* At least one repetition is required, so insert a
+`dummy_failure_jump' before the initial
+`on_failure_jump' instruction of the loop. This
+effects a skip over that instruction the first time
+we hit that loop.  */
+GET_BUFFER_SPACE (3);
+INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
+b += 3;
+}
+}
+	  break;
+	case '.':
+laststart = b;
+BUF_PUSH (anychar);
+break;
+case '[':
+{
+	    /* XEmacs change: this whole section */
+boolean had_char_class = false;
+if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+/* Ensure that we have enough space to push a charset: the
+opcode, the length count, and the bitset; 34 bytes in all.  */
+	    GET_BUFFER_SPACE (34);
+laststart = b;
+/* We test `*p == '^' twice, instead of using an if
+statement, so we only need one BUF_PUSH.  */
+BUF_PUSH (*p == '^' ? charset_not : charset);
+if (*p == '^')
+p++;
+/* Remember the first position in the bracket expression.  */
+p1 = p;
+/* Push the number of bytes in the bitmap.  */
+BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
+/* Clear the whole map.  */
+bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
+/* charset_not matches newline according to a syntax bit.  */
+if ((re_opcode_t) b[-2] == charset_not
+&& (syntax & RE_HAT_LISTS_NOT_NEWLINE))
+SET_LIST_BIT ('\n');
+/* Read in characters and ranges, setting map bits.  */
+for (;;)
+{
+if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+PATFETCH_EITHER (c);
+/* \ might escape characters inside [...] and [^...].  */
+if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
+{
+if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
+PATFETCH_EITHER (c1);
+SET_EITHER_BIT (c1);
+continue;
+}
+/* Could be the end of the bracket expression.  If it's
+not (i.e., when the bracket expression is `[]' so
+far), the ']' character bit gets set way below.  */
+if (c == ']' && p != p1 + 1)
+break;
+/* Look ahead to see if it's a range when the last thing
+was a character class.  */
+if (had_char_class && c == '-' && *p != ']')
+FREE_STACK_RETURN (REG_ERANGE);
+/* Look ahead to see if it's a range when the last thing
+was a character: if this is a hyphen not at the
+beginning or the end of a list, then it's the range
+operator.  */
+if (c == '-'
+&& !(p - 2 >= pattern && p[-2] == '[')
+&& !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
+&& *p != ']')
+{
+reg_errcode_t ret;
+		    ret = compile_range (&p, pend, translate, syntax, b);
+if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
+}
+else if (p[0] == '-' && p[1] != ']')
+{ /* This handles ranges made up of characters only.  */
+reg_errcode_t ret;
+		    /* Move past the `-'.  */
+PATFETCH (c1);
+		    ret = compile_range (&p, pend, translate, syntax, b);
+if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
+}
+/* See if we're at the beginning of a possible character
+class.  */
+else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
+{ /* Leave room for the null.  */
+char str[CHAR_CLASS_MAX_LENGTH + 1];
+PATFETCH (c);
+c1 = 0;
+/* If pattern is `[[:'.  */
+if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+for (;;)
+{
+			/* Do not do PATFETCH_EITHER() here.  We want
+			   to just see if the bytes match particular
+			   strings, and we put them all back if not.
+			   #### May need to be changed once trt tables
+			   are working. */
+PATFETCH (c);
+if (c == ':' || c == ']' || p == pend
+|| c1 == CHAR_CLASS_MAX_LENGTH)
+break;
+str[c1++] = c;
+}
+str[c1] = '\0';
+/* If isn't a word bracketed by `[:' and:`]':
+undo the ending character, the letters, and leave
+the leading `:' and `[' (but set bits for them).  */
+if (c == ':' && *p == ']')
+{
+int ch;
+boolean is_alnum = STREQ (str, "alnum");
+boolean is_alpha = STREQ (str, "alpha");
+boolean is_blank = STREQ (str, "blank");
+boolean is_cntrl = STREQ (str, "cntrl");
+boolean is_digit = STREQ (str, "digit");
+boolean is_graph = STREQ (str, "graph");
+boolean is_lower = STREQ (str, "lower");
+boolean is_print = STREQ (str, "print");
+boolean is_punct = STREQ (str, "punct");
+boolean is_space = STREQ (str, "space");
+boolean is_upper = STREQ (str, "upper");
+boolean is_xdigit = STREQ (str, "xdigit");
+if (!IS_CHAR_CLASS (str))
+			  FREE_STACK_RETURN (REG_ECTYPE);
+/* Throw away the ] at the end of the character
+class.  */
+PATFETCH (c);
+if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
+{
+			    /* This was split into 3 if's to
+			       avoid an arbitrary limit in some compiler.  */
+if (   (is_alnum  && ISALNUM (ch))
+|| (is_alpha  && ISALPHA (ch))
+|| (is_blank  && ISBLANK (ch))
+|| (is_cntrl  && ISCNTRL (ch)))
+			      SET_EITHER_BIT (ch);
+			    if (   (is_digit  && ISDIGIT (ch))
+|| (is_graph  && ISGRAPH (ch))
+|| (is_lower  && ISLOWER (ch))
+|| (is_print  && ISPRINT (ch)))
+			      SET_EITHER_BIT (ch);
+			    if (   (is_punct  && ISPUNCT (ch))
+|| (is_space  && ISSPACE (ch))
+|| (is_upper  && ISUPPER (ch))
+|| (is_xdigit && ISXDIGIT (ch)))
+			      SET_EITHER_BIT (ch);
+}
+had_char_class = true;
+}
+else
+{
+c1++;
+while (c1--)
+PATUNFETCH;
+SET_EITHER_BIT ('[');
+SET_EITHER_BIT (':');
+had_char_class = false;
+}
+}
+else
+{
+had_char_class = false;
+SET_EITHER_BIT (c);
+}
+}
+/* Discard any (non)matching list bytes that are all 0 at the
+end of the map.  Decrease the map-length byte too.  */
+while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
+b[-1]--;
+b += b[-1];
+	  }
+	  break;
+	case '(':
+if (syntax & RE_NO_BK_PARENS)
+goto handle_open;
+else
+goto normal_char;
+case ')':
+if (syntax & RE_NO_BK_PARENS)
+goto handle_close;
+else
+goto normal_char;
+case '\n':
+if (syntax & RE_NEWLINE_ALT)
+goto handle_alt;
+else
+goto normal_char;
+	case '|':
+if (syntax & RE_NO_BK_VBAR)
+goto handle_alt;
+else
+goto normal_char;
+case '{':
+if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
+goto handle_interval;
+else
+goto normal_char;
+case '\\':
+if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
+/* Do not translate the character after the \, so that we can
+distinguish, e.g., \B from \b, even if we normally would
+translate, e.g., B to b.  */
+PATFETCH_RAW (c);
+switch (c)
+{
+case '(':
+if (syntax & RE_NO_BK_PARENS)
+goto normal_backslash;
+handle_open:
+bufp->re_nsub++;
+regnum++;
+if (COMPILE_STACK_FULL)
+{
+RETALLOC (compile_stack.stack, compile_stack.size << 1,
+compile_stack_elt_t);
+if (compile_stack.stack == NULL) return REG_ESPACE;
+compile_stack.size <<= 1;
+}
+/* These are the values to restore when we hit end of this
+group.  They are all relative offsets, so that if the
+whole pattern moves because of realloc, they will still
+be valid.  */
+COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
+COMPILE_STACK_TOP.fixup_alt_jump
+= fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
+COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
+COMPILE_STACK_TOP.regnum = regnum;
+/* We will eventually replace the 0 with the number of
+groups inner to this one.  But do not push a
+start_memory for groups beyond the last one we can
+represent in the compiled pattern.  */
+if (regnum <= MAX_REGNUM)
+{
+COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
+BUF_PUSH_3 (start_memory, regnum, 0);
+}
+compile_stack.avail++;
+fixup_alt_jump = 0;
+laststart = 0;
+begalt = b;
+	      /* If we've reached MAX_REGNUM groups, then this open
+		 won't actually generate any code, so we'll have to
+		 clear pending_exact explicitly.  */
+	      pending_exact = 0;
+break;
+case ')':
+if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
+if (COMPILE_STACK_EMPTY)
+if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
+goto normal_backslash;
+else
+FREE_STACK_RETURN (REG_ERPAREN);
+handle_close:
+if (fixup_alt_jump)
+{ /* Push a dummy failure point at the end of the
+alternative for a possible future
+`pop_failure_jump' to pop.  See comments at
+`push_dummy_failure' in `re_match_2'.  */
+BUF_PUSH (push_dummy_failure);
+/* We allocated space for this jump when we assigned
+to `fixup_alt_jump', in the `handle_alt' case below.  */
+STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
+}
+/* See similar code for backslashed left paren above.  */
+if (COMPILE_STACK_EMPTY)
+if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
+goto normal_char;
+else
+FREE_STACK_RETURN (REG_ERPAREN);
+/* Since we just checked for an empty stack above, this
+``can't happen''.  */
+assert (compile_stack.avail != 0);
+{
+/* We don't just want to restore into `regnum', because
+later groups should continue to be numbered higher,
+as in `(ab)c(de)' -- the second group is #2.  */
+regnum_t this_group_regnum;
+compile_stack.avail--;
+begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
+fixup_alt_jump
+= COMPILE_STACK_TOP.fixup_alt_jump
+? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
+: 0;
+laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
+this_group_regnum = COMPILE_STACK_TOP.regnum;
+		/* If we've reached MAX_REGNUM groups, then this open
+		   won't actually generate any code, so we'll have to
+		   clear pending_exact explicitly.  */
+		pending_exact = 0;
+/* We're at the end of the group, so now we know how many
+groups were inside this one.  */
+if (this_group_regnum <= MAX_REGNUM)
+{
+unsigned char *inner_group_loc
+= bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
+*inner_group_loc = regnum - this_group_regnum;
+BUF_PUSH_3 (stop_memory, this_group_regnum,
+regnum - this_group_regnum);
+}
+}
+break;
+case '|':					/* `\|'.  */
+if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
+goto normal_backslash;
+handle_alt:
+if (syntax & RE_LIMITED_OPS)
+goto normal_char;
+/* Insert before the previous alternative a jump which
+jumps to this alternative if the former fails.  */
+GET_BUFFER_SPACE (3);
+INSERT_JUMP (on_failure_jump, begalt, b + 6);
+pending_exact = 0;
+b += 3;
+/* The alternative before this one has a jump after it
+which gets executed if it gets matched.  Adjust that
+jump so it will jump to this alternative's analogous
+jump (put in below, which in turn will jump to the next
+(if any) alternative's such jump, etc.).  The last such
+jump jumps to the correct final destination.  A picture:
+_____ _____
+|   | |   |
+|   v |   v
+a | b   | c
+If we are at `b', then fixup_alt_jump right now points to a
+three-byte space after `a'.  We'll put in the jump, set
+fixup_alt_jump to right after `b', and leave behind three
+bytes which we'll fill in when we get to after `c'.  */
+if (fixup_alt_jump)
+STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
+/* Mark and leave space for a jump after this alternative,
+to be filled in later either by next alternative or
+when know we're at the end of a series of alternatives.  */
+fixup_alt_jump = b;
+GET_BUFFER_SPACE (3);
+b += 3;
+laststart = 0;
+begalt = b;
+break;
+case '{':
+/* If \{ is a literal.  */
+if (!(syntax & RE_INTERVALS)
+/* If we're at `\{' and it's not the open-interval
+operator.  */
+|| ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
+|| (p - 2 == pattern  &&  p == pend))
+goto normal_backslash;
+handle_interval:
+{
+/* If got here, then the syntax allows intervals.  */
+/* At least (most) this many matches must be made.  */
+int lower_bound = -1, upper_bound = -1;
+beg_interval = p - 1;
+if (p == pend)
+{
+if (syntax & RE_NO_BK_BRACES)
+goto unfetch_interval;
+else
+FREE_STACK_RETURN (REG_EBRACE);
+}
+GET_UNSIGNED_NUMBER (lower_bound);
+if (c == ',')
+{
+GET_UNSIGNED_NUMBER (upper_bound);
+if (upper_bound < 0) upper_bound = RE_DUP_MAX;
+}
+else
+/* Interval such as `{1}' => match exactly once. */
+upper_bound = lower_bound;
+if (lower_bound < 0 || upper_bound > RE_DUP_MAX
+|| lower_bound > upper_bound)
+{
+if (syntax & RE_NO_BK_BRACES)
+goto unfetch_interval;
+else
+FREE_STACK_RETURN (REG_BADBR);
+}
+if (!(syntax & RE_NO_BK_BRACES))
+{
+if (c != '\\') FREE_STACK_RETURN (REG_EBRACE);
+PATFETCH (c);
+}
+if (c != '}')
+{
+if (syntax & RE_NO_BK_BRACES)
+goto unfetch_interval;
+else
+FREE_STACK_RETURN (REG_BADBR);
+}
+/* We just parsed a valid interval.  */
+/* If it's invalid to have no preceding re.  */
+if (!laststart)
+{
+if (syntax & RE_CONTEXT_INVALID_OPS)
+FREE_STACK_RETURN (REG_BADRPT);
+else if (syntax & RE_CONTEXT_INDEP_OPS)
+laststart = b;
+else
+goto unfetch_interval;
+}
+/* If the upper bound is zero, don't want to succeed at
+all; jump from `laststart' to `b + 3', which will be
+the end of the buffer after we insert the jump.  */
+if (upper_bound == 0)
+{
+GET_BUFFER_SPACE (3);
+INSERT_JUMP (jump, laststart, b + 3);
+b += 3;
+}
+/* Otherwise, we have a nontrivial interval.  When
+we're all done, the pattern will look like:
+set_number_at <jump count> <upper bound>
+set_number_at <succeed_n count> <lower bound>
+succeed_n <after jump addr> <succeed_n count>
+<body of loop>
+jump_n <succeed_n addr> <jump count>
+(The upper bound and `jump_n' are omitted if
+`upper_bound' is 1, though.)  */
+else
+{ /* If the upper bound is > 1, we need to insert
+more at the end of the loop.  */
+unsigned nbytes = 10 + (upper_bound > 1) * 10;
+GET_BUFFER_SPACE (nbytes);
+/* Initialize lower bound of the `succeed_n', even
+though it will be set during matching by its
+attendant `set_number_at' (inserted next),
+because `re_compile_fastmap' needs to know.
+Jump to the `jump_n' we might insert below.  */
+INSERT_JUMP2 (succeed_n, laststart,
+b + 5 + (upper_bound > 1) * 5,
+lower_bound);
+b += 5;
+/* Code to initialize the lower bound.  Insert
+before the `succeed_n'.  The `5' is the last two
+bytes of this `set_number_at', plus 3 bytes of
+the following `succeed_n'.  */
+insert_op2 (set_number_at, laststart, 5, lower_bound, b);
+b += 5;
+if (upper_bound > 1)
+{ /* More than one repetition is allowed, so
+append a backward jump to the `succeed_n'
+that starts this interval.
+When we've reached this during matching,
+we'll have matched the interval once, so
+jump back only `upper_bound - 1' times.  */
+STORE_JUMP2 (jump_n, b, laststart + 5,
+upper_bound - 1);
+b += 5;
+/* The location we want to set is the second
+parameter of the `jump_n'; that is `b-2' as
+an absolute address.  `laststart' will be
+the `set_number_at' we're about to insert;
+`laststart+3' the number to set, the source
+for the relative address.  But we are
+inserting into the middle of the pattern --
+so everything is getting moved up by 5.
+Conclusion: (b - 2) - (laststart + 3) + 5,
+i.e., b - laststart.
+We insert this at the beginning of the loop
+so that if we fail during matching, we'll
+reinitialize the bounds.  */
+insert_op2 (set_number_at, laststart, b - laststart,
+upper_bound - 1, b);
+b += 5;
+}
+}
+pending_exact = 0;
+beg_interval = NULL;
+}
+break;
+unfetch_interval:
+/* If an invalid interval, match the characters as literals.  */
+assert (beg_interval);
+p = beg_interval;
+beg_interval = NULL;
+/* normal_char and normal_backslash need `c'.  */
+PATFETCH (c);
+if (!(syntax & RE_NO_BK_BRACES))
+{
+if (p > pattern  &&  p[-1] == '\\')
+goto normal_backslash;
+}
+goto normal_char;
+#ifdef emacs
+/* There is no way to specify the before_dot and after_dot
+operators.  rms says this is ok.  --karl  */
+case '=':
+BUF_PUSH (at_dot);
+break;
+case 's':
+laststart = b;
+PATFETCH (c);
+	      /* XEmacs addition */
+	      if (c >= 0x80 || syntax_spec_code[c] == 0377)
+		FREE_STACK_RETURN (REG_ESYNTAX);
+BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
+break;
+case 'S':
+laststart = b;
+PATFETCH (c);
+	      /* XEmacs addition */
+	      if (c >= 0x80 || syntax_spec_code[c] == 0377)
+		FREE_STACK_RETURN (REG_ESYNTAX);
+BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
+break;
+#endif /* emacs */
+case 'w':
+laststart = b;
+BUF_PUSH (wordchar);
+break;
+case 'W':
+laststart = b;
+BUF_PUSH (notwordchar);
+break;
+case '<':
+BUF_PUSH (wordbeg);
+break;
+case '>':
+BUF_PUSH (wordend);
+break;
+case 'b':
+BUF_PUSH (wordbound);
+break;
+case 'B':
+BUF_PUSH (notwordbound);
+break;
+case '`':
+BUF_PUSH (begbuf);
+break;
+case '\'':
+BUF_PUSH (endbuf);
+break;
+case '1': case '2': case '3': case '4': case '5':
+case '6': case '7': case '8': case '9':
+if (syntax & RE_NO_BK_REFS)
+goto normal_char;
+c1 = c - '0';
+if (c1 > regnum)
+FREE_STACK_RETURN (REG_ESUBREG);
+/* Can't back reference to a subexpression if inside of it.  */
+if (group_in_compile_stack (compile_stack, c1))
+goto normal_char;
+laststart = b;
+BUF_PUSH_2 (duplicate, c1);
+break;
+case '+':
+case '?':
+if (syntax & RE_BK_PLUS_QM)
+goto handle_plus;
+else
+goto normal_backslash;
+default:
+normal_backslash:
+/* You might think it would be useful for \ to mean
+not to translate; but if we don't translate it
+it will never match anything.  */
+c = TRANSLATE (c);
+goto normal_char;
+}
+break;
+	default:
+/* Expects the character in `c'.  */
+	/* `p' points to the location after where `c' came from. */
+	normal_char:
+	  {
+	    /* XEmacs: modifications here for Mule. */
+	    /* `q' points to the beginning of the next char. */
+	    CONST char *q = p - 1;
+	    INC_CHARPTR (q);
+	    /* If no exactn currently being built.  */
+	    if (!pending_exact
+		/* If last exactn not at current position.  */
+		|| pending_exact + *pending_exact + 1 != b
+		/* We have only one byte following the exactn for the count. */
+		|| ((unsigned int) (*pending_exact + (q - p)) >=
+		    ((unsigned int) (1 << BYTEWIDTH) - 1))
+		/* If followed by a repetition operator.  */
+		|| *q == '*' || *q == '^'
+		|| ((syntax & RE_BK_PLUS_QM)
+		    ? *q == '\\' && (q[1] == '+' || q[1] == '?')
+		    : (*q == '+' || *q == '?'))
+		|| ((syntax & RE_INTERVALS)
+		    && ((syntax & RE_NO_BK_BRACES)
+			? *q == '{'
+			: (q[0] == '\\' && q[1] == '{'))))
+	      {
+		/* Start building a new exactn.  */
+		laststart = b;
+		BUF_PUSH_2 (exactn, 0);
+		pending_exact = b - 1;
+	      }
+	    BUF_PUSH (c);
+	    (*pending_exact)++;
+	    while (p < q)
+	      {
+		PATFETCH (c);
+		BUF_PUSH (c);
+		(*pending_exact)++;
+	      }
+	    break;
+	  }
+} /* switch (c) */
+} /* while p != pend */
+/* Through the pattern now.  */
+if (fixup_alt_jump)
+STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
+if (!COMPILE_STACK_EMPTY)
+FREE_STACK_RETURN (REG_EPAREN);
+/* If we don't want backtracking, force success
+the first time we reach the end of the compiled pattern.  */
+if (syntax & RE_NO_POSIX_BACKTRACKING)
+BUF_PUSH (succeed);
+free (compile_stack.stack);
+/* We have succeeded; set the length of the buffer.  */
+bufp->used = b - bufp->buffer;
+#ifdef DEBUG
+if (debug)
+{
+DEBUG_PRINT1 ("\nCompiled pattern: \n");
+print_compiled_pattern (bufp);
+}
+#endif /* DEBUG */
+#ifndef MATCH_MAY_ALLOCATE
+/* Initialize the failure stack to the largest possible stack.  This
+isn't necessary unless we're trying to avoid calling alloca in
+the search and match routines.  */
+{
+int num_regs = bufp->re_nsub + 1;
+/* Since DOUBLE_FAIL_STACK refuses to double only if the current size
+is strictly greater than re_max_failures, the largest possible stack
+is 2 * re_max_failures failure points.  */
+if (fail_stack.size < (2 * re_max_failures * MAX_FAILURE_ITEMS))
+{
+	fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);
+#ifdef emacs
+	if (! fail_stack.stack)
+	  fail_stack.stack
+	    = (fail_stack_elt_t *) xmalloc (fail_stack.size
+					    * sizeof (fail_stack_elt_t));
+	else
+	  fail_stack.stack
+	    = (fail_stack_elt_t *) xrealloc (fail_stack.stack,
+					     (fail_stack.size
+					      * sizeof (fail_stack_elt_t)));
+#else /* not emacs */
+	if (! fail_stack.stack)
+	  fail_stack.stack
+	    = (fail_stack_elt_t *) malloc (fail_stack.size
+					   * sizeof (fail_stack_elt_t));
+	else
+	  fail_stack.stack
+	    = (fail_stack_elt_t *) realloc (fail_stack.stack,
+					    (fail_stack.size
+					     * sizeof (fail_stack_elt_t)));
+#endif /* not emacs */
+}
+regex_grow_registers (num_regs);
+}
+#endif /* not MATCH_MAY_ALLOCATE */
+return REG_NOERROR;
+} /* regex_compile */
+/* Subroutines for `regex_compile'.  */
+/* Store OP at LOC followed by two-byte integer parameter ARG.  */
+static void
+store_op1 (re_opcode_t op, unsigned char *loc, int arg)
+{
+*loc = (unsigned char) op;
+STORE_NUMBER (loc + 1, arg);
+}
+/* Like `store_op1', but for two two-byte parameters ARG1 and ARG2.  */
+static void
+store_op2 (re_opcode_t op, unsigned char *loc, int arg1, int arg2)
+{
+*loc = (unsigned char) op;
+STORE_NUMBER (loc + 1, arg1);
+STORE_NUMBER (loc + 3, arg2);
+}
+/* Copy the bytes from LOC to END to open up three bytes of space at LOC
+for OP followed by two-byte integer parameter ARG.  */
+static void
+insert_op1 (re_opcode_t op, unsigned char *loc, int arg, unsigned char *end)
+{
+register unsigned char *pfrom = end;
+register unsigned char *pto = end + 3;
+while (pfrom != loc)
+*--pto = *--pfrom;
+store_op1 (op, loc, arg);
+}
+/* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2.  */
+static void
+insert_op2 (re_opcode_t op, unsigned char *loc, int arg1, int arg2,
+	    unsigned char *end)
+{
+register unsigned char *pfrom = end;
+register unsigned char *pto = end + 5;
+while (pfrom != loc)
+*--pto = *--pfrom;
+store_op2 (op, loc, arg1, arg2);
+}
+/* P points to just after a ^ in PATTERN.  Return true if that ^ comes
+after an alternative or a begin-subexpression.  We assume there is at
+least one character before the ^.  */
+static boolean
+at_begline_loc_p (CONST char *pattern, CONST char *p, reg_syntax_t syntax)
+{
+CONST char *prev = p - 2;
+boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
+return
+/* After a subexpression?  */
+(*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
+/* After an alternative?  */
+|| (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
+}
+/* The dual of at_begline_loc_p.  This one is for $.  We assume there is
+at least one character after the $, i.e., `P < PEND'.  */
+static boolean
+at_endline_loc_p (CONST char *p, CONST char *pend, int syntax)
+{
+CONST char *next = p;
+boolean next_backslash = *next == '\\';
+CONST char *next_next = p + 1 < pend ? p + 1 : 0;
+return
+/* Before a subexpression?  */
+(syntax & RE_NO_BK_PARENS ? *next == ')'
+: next_backslash && next_next && *next_next == ')')
+/* Before an alternative?  */
+|| (syntax & RE_NO_BK_VBAR ? *next == '|'
+: next_backslash && next_next && *next_next == '|');
+}
+/* Returns true if REGNUM is in one of COMPILE_STACK's elements and
+false if it's not.  */
+static boolean
+group_in_compile_stack (compile_stack_type compile_stack, regnum_t regnum)
+{
+int this_element;
+for (this_element = compile_stack.avail - 1;
+this_element >= 0;
+this_element--)
+if (compile_stack.stack[this_element].regnum == regnum)
+return true;
+return false;
+}
+/* Read the ending character of a range (in a bracket expression) from the
+uncompiled pattern *P_PTR (which ends at PEND).  We assume the
+starting character is in `P[-2]'.  (`P[-1]' is the character `-'.)
+Then we set the translation of all bits between the starting and
+ending characters (inclusive) in the compiled pattern B.
+Return an error code.
+We use these short variable names so we can use the same macros as
+`regex_compile' itself.  */
+static reg_errcode_t
+compile_range (CONST char **p_ptr, CONST char *pend, char *translate,
+	       reg_syntax_t syntax, unsigned char *b)
+{
+unsigned this_char;
+CONST char *p = *p_ptr;
+int range_start, range_end;
+if (p == pend)
+return REG_ERANGE;
+/* Even though the pattern is a signed `char *', we need to fetch
+with unsigned char *'s; if the high bit of the pattern character
+is set, the range endpoints will be negative if we fetch using a
+signed char *.
+We also want to fetch the endpoints without translating them; the
+appropriate translation is done in the bit-setting loop below.  */
+/* The SVR4 compiler on the 3B2 had trouble with unsigned CONST char *.  */
+range_start = ((CONST unsigned char *) p)[-2];
+range_end   = ((CONST unsigned char *) p)[0];
+/* Have to increment the pointer into the pattern string, so the
+caller isn't still at the ending character.  */
+(*p_ptr)++;
+/* If the start is after the end, the range is empty.  */
+if (range_start > range_end)
+return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
+/* Here we see why `this_char' has to be larger than an `unsigned
+char' -- the range is inclusive, so if `range_end' == 0xff
+(assuming 8-bit characters), we would otherwise go into an infinite
+loop, since all characters <= 0xff.  */
+for (this_char = range_start; this_char <= range_end; this_char++)
+{
+SET_LIST_BIT (TRANSLATE (this_char));
+}
+return REG_NOERROR;
+}
+/* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
+BUFP.  A fastmap records which of the (1 << BYTEWIDTH) possible
+characters can start a string that matches the pattern.  This fastmap
+is used by re_search to skip quickly over impossible starting points.
+The caller must supply the address of a (1 << BYTEWIDTH)-byte data
+area as BUFP->fastmap.
+We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
+the pattern buffer.
+Returns 0 if we succeed, -2 if an internal error.   */
+int
+re_compile_fastmap (struct re_pattern_buffer *bufp)
+{
+int j, k;
+#ifdef MATCH_MAY_ALLOCATE
+fail_stack_type fail_stack;
+#endif
+DECLARE_DESTINATION
+/* We don't push any register information onto the failure stack.  */
+unsigned num_regs = 0;
+register char *fastmap = bufp->fastmap;
+unsigned char *pattern = bufp->buffer;
+unsigned long size = bufp->used;
+unsigned char *p = pattern;
+register unsigned char *pend = pattern + size;
+#ifdef REL_ALLOC
+/* This holds the pointer to the failure stack, when
+it is allocated relocatably.  */
+fail_stack_elt_t *failure_stack_ptr;
+#endif
+/* Assume that each path through the pattern can be null until
+proven otherwise.  We set this false at the bottom of switch
+statement, to which we get only if a particular path doesn't
+match the empty string.  */
+boolean path_can_be_null = true;
+/* We aren't doing a `succeed_n' to begin with.  */
+boolean succeed_n_p = false;
+assert (fastmap != NULL && p != NULL);
+INIT_FAIL_STACK ();
+bzero (fastmap, 1 << BYTEWIDTH);  /* Assume nothing's valid.  */
+bufp->fastmap_accurate = 1;	    /* It will be when we're done.  */
+bufp->can_be_null = 0;
+while (1)
+{
+if (p == pend || *p == succeed)
+	{
+	  /* We have reached the (effective) end of pattern.  */
+	  if (!FAIL_STACK_EMPTY ())
+	    {
+	      bufp->can_be_null |= path_can_be_null;
+	      /* Reset for next path.  */
+	      path_can_be_null = true;
+	      p = fail_stack.stack[--fail_stack.avail].pointer;
+	      continue;
+	    }
+	  else
+	    break;
+	}
+/* We should never be about to go beyond the end of the pattern.  */
+assert (p < pend);
+switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
+	{
+/* I guess the idea here is to simply not bother with a fastmap
+if a backreference is used, since it's too hard to figure out
+the fastmap for the corresponding group.  Setting
+`can_be_null' stops `re_search_2' from using the fastmap, so
+that is all we do.  */
+	case duplicate:
+	  bufp->can_be_null = 1;
+goto done;
+/* Following are the cases which match a character.  These end
+with `break'.  */
+	case exactn:
+fastmap[p[1]] = 1;
+	  break;
+case charset:
+for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
+	    if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
+fastmap[j] = 1;
+	  break;
+	case charset_not:
+	  /* Chars beyond end of map must be allowed.  */
+	  for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
+fastmap[j] = 1;
+	  for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
+	    if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
+fastmap[j] = 1;
+break;
+	case wordchar:
+#ifdef emacs
+	  k = (int) Sword;
+	  goto matchsyntax;
+#else
+	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+	    if (SYNTAX_UNSAFE (regex_emacs_buffer->syntax_table, j) == Sword)
+	      fastmap[j] = 1;
+	  break;
+#endif
+	case notwordchar:
+#ifdef emacs
+	  k = (int) Sword;
+	  goto matchnotsyntax;
+#else
+	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+	    if (SYNTAX_UNSAFE (regex_emacs_buffer->syntax_table, j) != Sword)
+	      fastmap[j] = 1;
+	  break;
+#endif
+case anychar:
+	  {
+	    int fastmap_newline = fastmap['\n'];
+	    /* `.' matches anything ...  */
+	    for (j = 0; j < (1 << BYTEWIDTH); j++)
+	      fastmap[j] = 1;
+	    /* ... except perhaps newline.  */
+	    if (!(bufp->syntax & RE_DOT_NEWLINE))
+	      fastmap['\n'] = fastmap_newline;
+	    /* Return if we have already set `can_be_null'; if we have,
+	       then the fastmap is irrelevant.  Something's wrong here.  */
+	    else if (bufp->can_be_null)
+	      goto done;
+	    /* Otherwise, have to check alternative paths.  */
+	    break;
+	  }
+#ifdef emacs
+case syntaxspec:
+	  k = *p++;
+	  matchsyntax:
+	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+	    if (SYNTAX_UNSAFE (regex_emacs_buffer->syntax_table, j) ==
+		(enum syntaxcode) k)
+	      fastmap[j] = 1;
+	  break;
+	case notsyntaxspec:
+	  k = *p++;
+	  matchnotsyntax:
+	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+	    if (SYNTAX_UNSAFE (regex_emacs_buffer->syntax_table, j) !=
+		(enum syntaxcode) k)
+	      fastmap[j] = 1;
+	  break;
+/* All cases after this match the empty string.  These end with
+`continue'.  */
+	case before_dot:
+	case at_dot:
+	case after_dot:
+continue;
+#endif /* not emacs */
+case no_op:
+case begline:
+case endline:
+	case begbuf:
+	case endbuf:
+	case wordbound:
+	case notwordbound:
+	case wordbeg:
+	case wordend:
+case push_dummy_failure:
+continue;
+	case jump_n:
+case pop_failure_jump:
+	case maybe_pop_jump:
+	case jump:
+case jump_past_alt:
+	case dummy_failure_jump:
+EXTRACT_NUMBER_AND_INCR (j, p);
+	  p += j;
+	  if (j > 0)
+	    continue;
+/* Jump backward implies we just went through the body of a
+loop and matched nothing.  Opcode jumped to should be
+`on_failure_jump' or `succeed_n'.  Just treat it like an
+ordinary jump.  For a * loop, it has pushed its failure
+point already; if so, discard that as redundant.  */
+if ((re_opcode_t) *p != on_failure_jump
+	      && (re_opcode_t) *p != succeed_n)
+	    continue;
+p++;
+EXTRACT_NUMBER_AND_INCR (j, p);
+p += j;
+/* If what's on the stack is where we are now, pop it.  */
+if (!FAIL_STACK_EMPTY ()
+	      && fail_stack.stack[fail_stack.avail - 1].pointer == p)
+fail_stack.avail--;
+continue;
+case on_failure_jump:
+case on_failure_keep_string_jump:
+	handle_on_failure_jump:
+EXTRACT_NUMBER_AND_INCR (j, p);
+/* For some patterns, e.g., `(a?)?', `p+j' here points to the
+end of the pattern.  We don't want to push such a point,
+since when we restore it above, entering the switch will
+increment `p' past the end of the pattern.  We don't need
+to push such a point since we obviously won't find any more
+fastmap entries beyond `pend'.  Such a pattern can match
+the null string, though.  */
+if (p + j < pend)
+{
+if (!PUSH_PATTERN_OP (p + j, fail_stack))
+		{
+		  RESET_FAIL_STACK ();
+		  return -2;
+		}
+}
+else
+bufp->can_be_null = 1;
+if (succeed_n_p)
+{
+EXTRACT_NUMBER_AND_INCR (k, p);	/* Skip the n.  */
+succeed_n_p = false;
+	    }
+continue;
+	case succeed_n:
+/* Get to the number of times to succeed.  */
+p += 2;
+/* Increment p past the n for when k != 0.  */
+EXTRACT_NUMBER_AND_INCR (k, p);
+if (k == 0)
+	    {
+p -= 4;
+	      succeed_n_p = true;  /* Spaghetti code alert.  */
+goto handle_on_failure_jump;
+}
+continue;
+	case set_number_at:
+p += 4;
+continue;
+	case start_memory:
+case stop_memory:
+	  p += 2;
+	  continue;
+	default:
+abort (); /* We have listed all the cases.  */
+} /* switch *p++ */
+/* Getting here means we have found the possible starting
+characters for one path of the pattern -- and that the empty
+string does not match.  We need not follow this path further.
+Instead, look at the next alternative (remembered on the
+stack), or quit if no more.  The test at the top of the loop
+does these things.  */
+path_can_be_null = false;
+p = pend;
+} /* while p */
+/* Set `can_be_null' for the last path (also the first path, if the
+pattern is empty).  */
+bufp->can_be_null |= path_can_be_null;
+done:
+RESET_FAIL_STACK ();
+return 0;
+} /* re_compile_fastmap */
+/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
+ENDS.  Subsequent matches using PATTERN_BUFFER and REGS will use
+this memory for recording register information.  STARTS and ENDS
+must be allocated using the malloc library routine, and must each
+be at least NUM_REGS * sizeof (regoff_t) bytes long.
+If NUM_REGS == 0, then subsequent matches should allocate their own
+register data.
+Unless this function is called, the first search or match using
+PATTERN_BUFFER will allocate its own register data, without
+freeing the old data.  */
+void
+re_set_registers (struct re_pattern_buffer *bufp, struct re_registers *regs,
+		  unsigned num_regs, regoff_t *starts, regoff_t *ends)
+{
+if (num_regs)
+{
+bufp->regs_allocated = REGS_REALLOCATE;
+regs->num_regs = num_regs;
+regs->start = starts;
+regs->end = ends;
+}
+else
+{
+bufp->regs_allocated = REGS_UNALLOCATED;
+regs->num_regs = 0;
+regs->start = regs->end = (regoff_t *) 0;
+}
+}
+/* Searching routines.  */
+/* Like re_search_2, below, but only one string is specified, and
+doesn't let you say where to stop matching. */
+int
+re_search (struct re_pattern_buffer *bufp, CONST char *string, int size,
+	   int startpos, int range, struct re_registers *regs)
+{
+return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
+		      regs, size);
+}
+/* Using the compiled pattern in BUFP->buffer, first tries to match the
+virtual concatenation of STRING1 and STRING2, starting first at index
+STARTPOS, then at STARTPOS + 1, and so on.
+STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
+RANGE is how far to scan while trying to match.  RANGE = 0 means try
+only at STARTPOS; in general, the last start tried is STARTPOS +
+RANGE.
+In REGS, return the indices of the virtual concatenation of STRING1
+and STRING2 that matched the entire BUFP->buffer and its contained
+subexpressions.
+Do not consider matching one past the index STOP in the virtual
+concatenation of STRING1 and STRING2.
+We return either the position in the strings at which the match was
+found, -1 if no match, or -2 if error (such as failure
+stack overflow).  */
+int
+re_search_2 (struct re_pattern_buffer *bufp, CONST char *string1,
+	     int size1, CONST char *string2, int size2, int startpos,
+	     int range, struct re_registers *regs, int stop)
+{
+int val;
+register char *fastmap = bufp->fastmap;
+register char *translate = bufp->translate;
+int total_size = size1 + size2;
+int endpos = startpos + range;
+#ifdef REGEX_BEGLINE_CHECK
+int anchored_at_begline = 0;
+#endif
+/* Check for out-of-range STARTPOS.  */
+if (startpos < 0 || startpos > total_size)
+return -1;
+/* Fix up RANGE if it might eventually take us outside
+the virtual concatenation of STRING1 and STRING2.  */
+if (endpos < -1)
+range = -1 - startpos;
+else if (endpos > total_size)
+range = total_size - startpos;
+/* If the search isn't to be a backwards one, don't waste time in a
+search for a pattern that must be anchored.  */
+if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
+{
+if (startpos > 0)
+	return -1;
+else
+	range = 1;
+}
+/* Update the fastmap now if not correct already.  */
+if (fastmap && !bufp->fastmap_accurate)
+if (re_compile_fastmap (bufp) == -2)
+return -2;
+#ifdef REGEX_BEGLINE_CHECK
+{
+int i = 0;
+while (i < bufp->used)
+{
+	if (bufp->buffer[i] == start_memory ||
+	    bufp->buffer[i] == stop_memory)
+	  i += 2;
+	else
+	  break;
+}
+anchored_at_begline = i < bufp->used && bufp->buffer[i] == begline;
+}
+#endif
+/* Loop through the string, looking for a place to start matching.  */
+for (;;)
+{
+#ifdef REGEX_BEGLINE_CHECK
+/* If the regex is anchored at the beginning of a line (i.e. with a ^),
+	 then we can speed things up by skipping to the next beginning-of-
+	 line. */
+if (anchored_at_begline && startpos > 0 && startpos != size1 &&
+	  range > 0)
+	{
+	  /* whose stupid idea was it anyway to make this
+	     function take two strings to match?? */
+	  int lim = 0;
+	  unsigned char *p;
+	  int irange = range;
+	  if (startpos < size1 && startpos + range >= size1)
+	    lim = range - (size1 - startpos);
+	  p = ((unsigned char *)
+	       &(startpos >= size1 ? string2 - size1 : string1)[startpos]);
+	  p--;
+	  if (translate)
+	    {
+	      while (range > lim && translate[*p++] != '\n')
+		range--;
+	    }
+	  else
+	    {
+	      while (range > lim && *p++ != '\n')
+		range--;
+	    }
+	  startpos += irange - range;
+	}
+#endif /* REGEX_BEGLINE_CHECK */
+/* If a fastmap is supplied, skip quickly over characters that
+cannot be the start of a match.  If the pattern can match the
+null string, however, we don't need to skip characters; we want
+the first null string.  */
+if (fastmap && startpos < total_size && !bufp->can_be_null)
+	{
+	  if (range > 0)	/* Searching forwards.  */
+	    {
+	      register CONST char *d;
+	      register int lim = 0;
+	      int irange = range;
+if (startpos < size1 && startpos + range >= size1)
+lim = range - (size1 - startpos);
+	      d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
+/* Written out as an if-else to avoid testing `translate'
+inside the loop.  */
+	      if (translate)
+while (range > lim
+&& !fastmap[(unsigned char)
+				   translate[(unsigned char) *d++]])
+range--;
+	      else
+while (range > lim && !fastmap[(unsigned char) *d++])
+range--;
+	      startpos += irange - range;
+	    }
+	  else				/* Searching backwards.  */
+	    {
+	      register char c = (size1 == 0 || startpos >= size1
+? string2[startpos - size1]
+: string1[startpos]);
+	      if (!fastmap[(unsigned char) TRANSLATE (c)])
+		goto advance;
+	    }
+	}
+/* If can't match the null string, and that's all we have left, fail.  */
+if (range >= 0 && startpos == total_size && fastmap
+&& !bufp->can_be_null)
+	return -1;
+#ifdef emacs /* XEmacs added, w/removal of immediate_quit */
+if (!no_quit_in_re_search)
+	QUIT;
+#endif
+val = re_match_2_internal (bufp, string1, size1, string2, size2,
+				 startpos, regs, stop);
+#ifndef REGEX_MALLOC
+#ifdef C_ALLOCA
+alloca (0);
+#endif
+#endif
+if (val >= 0)
+	return startpos;
+if (val == -2)
+	return -2;
+advance:
+if (!range)
+break;
+else if (range > 0)
+{
+range--;
+startpos++;
+}
+else
+{
+range++;
+startpos--;
+}
+}
+return -1;
+} /* re_search_2 */
+/* Declarations and macros for re_match_2.  */
+/* This converts PTR, a pointer into one of the search strings `string1'
+and `string2' into an offset from the beginning of that string.  */
+#define POINTER_TO_OFFSET(ptr)			\
+(FIRST_STRING_P (ptr)				\
+? ((regoff_t) ((ptr) - string1))		\
+: ((regoff_t) ((ptr) - string2 + size1)))
+/* Macros for dealing with the split strings in re_match_2.  */
+#define MATCHING_IN_FIRST_STRING  (dend == end_match_1)
+/* Call before fetching a character with *d.  This switches over to
+string2 if necessary.  */
+#define PREFETCH()							\
+while (d == dend)						    	\
+{									\
+/* End of string2 => fail.  */					\
+if (dend == end_match_2) 						\
+goto fail;							\
+/* End of string1 => advance to string2.  */ 			\
+d = string2;						        \
+dend = end_match_2;						\
+}
+/* Test if at very beginning or at very end of the virtual concatenation
+of `string1' and `string2'.  If only one string, it's `string2'.  */
+#define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
+#define AT_STRINGS_END(d) ((d) == end2)
+/* XEmacs change:
+If the given position straddles the string gap, return the equivalent
+position that is before or after the gap, respectively; otherwise,
+return the same position. */
+#define POS_BEFORE_GAP_UNSAFE(d) ((d) == string2 ? end1 : (d))
+#define POS_AFTER_GAP_UNSAFE(d) ((d) == end1 ? string2 : (d))
+/* Test if CH is a word-constituent character. (XEmacs change) */
+#define WORDCHAR_P_UNSAFE(ch)						   \
+(SYNTAX_UNSAFE (regex_emacs_buffer->syntax_table, ch) == Sword)
+/* Free everything we malloc.  */
+#ifdef MATCH_MAY_ALLOCATE
+#define FREE_VAR(var) if (var) REGEX_FREE (var); var = NULL
+#define FREE_VARIABLES()						\
+do {									\
+REGEX_FREE_STACK (fail_stack.stack);				\
+FREE_VAR (regstart);						\
+FREE_VAR (regend);							\
+FREE_VAR (old_regstart);						\
+FREE_VAR (old_regend);						\
+FREE_VAR (best_regstart);						\
+FREE_VAR (best_regend);						\
+FREE_VAR (reg_info);						\
+FREE_VAR (reg_dummy);						\
+FREE_VAR (reg_info_dummy);						\
+} while (0)
+#else
+#define FREE_VARIABLES() ((void)0) /* Do nothing!  But inhibit gcc warning.  */
+#endif /* not MATCH_MAY_ALLOCATE */
+/* These values must meet several constraints.  They must not be valid
+register values; since we have a limit of 255 registers (because
+we use only one byte in the pattern for the register number), we can
+use numbers larger than 255.  They must differ by 1, because of
+NUM_FAILURE_ITEMS above.  And the value for the lowest register must
+be larger than the value for the highest register, so we do not try
+to actually save any registers when none are active.  */
+#define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
+#define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
+/* Matching routines.  */
+#ifndef emacs   /* Emacs never uses this.  */
+/* re_match is like re_match_2 except it takes only a single string.  */
+int
+re_match (struct re_pattern_buffer *bufp, CONST char *string, int size,
+	  int pos, struct re_registers *regs)
+{
+int result = re_match_2_internal (bufp, NULL, 0, string, size,
+				    pos, regs, size);
+alloca (0);
+return result;
+}
+#endif /* not emacs */
+/* re_match_2 matches the compiled pattern in BUFP against the
+the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
+and SIZE2, respectively).  We start matching at POS, and stop
+matching at STOP.
+If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
+store offsets for the substring each group matched in REGS.  See the
+documentation for exactly how many groups we fill.
+We return -1 if no match, -2 if an internal error (such as the
+failure stack overflowing).  Otherwise, we return the length of the
+matched substring.  */
+int
+re_match_2 (struct re_pattern_buffer *bufp, CONST char *string1,
+	    int size1, CONST char *string2, int size2, int pos,
+	    struct re_registers *regs, int stop)
+{
+int result = re_match_2_internal (bufp, string1, size1, string2, size2,
+				    pos, regs, stop);
+alloca (0);
+return result;
+}
+/* This is a separate function so that we can force an alloca cleanup
+afterwards.  */
+static int
+re_match_2_internal (struct re_pattern_buffer *bufp, CONST char *string1,
+		     int size1, CONST char *string2, int size2, int pos,
+		     struct re_registers *regs, int stop)
+{
+/* General temporaries.  */
+int mcnt;
+unsigned char *p1;
+int should_succeed; /* XEmacs change */
+/* Just past the end of the corresponding string.  */
+CONST char *end1, *end2;
+/* Pointers into string1 and string2, just past the last characters in
+each to consider matching.  */
+CONST char *end_match_1, *end_match_2;
+/* Where we are in the data, and the end of the current string.  */
+CONST char *d, *dend;
+/* Where we are in the pattern, and the end of the pattern.  */
+unsigned char *p = bufp->buffer;
+register unsigned char *pend = p + bufp->used;
+/* Mark the opcode just after a start_memory, so we can test for an
+empty subpattern when we get to the stop_memory.  */
+unsigned char *just_past_start_mem = 0;
+/* We use this to map every character in the string.  */
+char *translate = bufp->translate;
+/* Failure point stack.  Each place that can handle a failure further
+down the line pushes a failure point on this stack.  It consists of
+restart, regend, and reg_info for all registers corresponding to
+the subexpressions we're currently inside, plus the number of such
+registers, and, finally, two char *'s.  The first char * is where
+to resume scanning the pattern; the second one is where to resume
+scanning the strings.  If the latter is zero, the failure point is
+a ``dummy''; if a failure happens and the failure point is a dummy,
+it gets discarded and the next next one is tried.  */
+#ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global.  */
+fail_stack_type fail_stack;
+#endif
+#ifdef DEBUG
+static unsigned failure_id;
+unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
+#endif
+#ifdef REL_ALLOC
+/* This holds the pointer to the failure stack, when
+it is allocated relocatably.  */
+fail_stack_elt_t *failure_stack_ptr;
+#endif
+/* We fill all the registers internally, independent of what we
+return, for use in backreferences.  The number here includes
+an element for register zero.  */
+unsigned num_regs = bufp->re_nsub + 1;
+/* The currently active registers.  */
+unsigned lowest_active_reg = NO_LOWEST_ACTIVE_REG;
+unsigned highest_active_reg = NO_HIGHEST_ACTIVE_REG;
+/* Information on the contents of registers. These are pointers into
+the input strings; they record just what was matched (on this
+attempt) by a subexpression part of the pattern, that is, the
+regnum-th regstart pointer points to where in the pattern we began
+matching and the regnum-th regend points to right after where we
+stopped matching the regnum-th subexpression.  (The zeroth register
+keeps track of what the whole pattern matches.)  */
+#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
+CONST char **regstart, **regend;
+#endif
+/* If a group that's operated upon by a repetition operator fails to
+match anything, then the register for its start will need to be
+restored because it will have been set to wherever in the string we
+are when we last see its open-group operator.  Similarly for a
+register's end.  */
+#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
+CONST char **old_regstart, **old_regend;
+#endif
+/* The is_active field of reg_info helps us keep track of which (possibly
+nested) subexpressions we are currently in. The matched_something
+field of reg_info[reg_num] helps us tell whether or not we have
+matched any of the pattern so far this time through the reg_num-th
+subexpression.  These two fields get reset each time through any
+loop their register is in.  */
+#ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global.  */
+register_info_type *reg_info;
+#endif
+/* The following record the register info as found in the above
+variables when we find a match better than any we've seen before.
+This happens as we backtrack through the failure points, which in
+turn happens only if we have not yet matched the entire string. */
+unsigned best_regs_set = false;
+#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
+CONST char **best_regstart, **best_regend;
+#endif
+/* Logically, this is `best_regend[0]'.  But we don't want to have to
+allocate space for that if we're not allocating space for anything
+else (see below).  Also, we never need info about register 0 for
+any of the other register vectors, and it seems rather a kludge to
+treat `best_regend' differently than the rest.  So we keep track of
+the end of the best match so far in a separate variable.  We
+initialize this to NULL so that when we backtrack the first time
+and need to test it, it's not garbage.  */
+CONST char *match_end = NULL;
+/* This helps SET_REGS_MATCHED avoid doing redundant work.  */
+int set_regs_matched_done = 0;
+/* Used when we pop values we don't care about.  */
+#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
+CONST char **reg_dummy;
+register_info_type *reg_info_dummy;
+#endif
+#ifdef DEBUG
+/* Counts the total number of registers pushed.  */
+unsigned num_regs_pushed = 0;
+#endif
+DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
+INIT_FAIL_STACK ();
+#ifdef MATCH_MAY_ALLOCATE
+/* Do not bother to initialize all the register variables if there are
+no groups in the pattern, as it takes a fair amount of time.  If
+there are groups, we include space for register 0 (the whole
+pattern), even though we never use it, since it simplifies the
+array indexing.  We should fix this.  */
+if (bufp->re_nsub)
+{
+regstart = REGEX_TALLOC (num_regs, CONST char *);
+regend = REGEX_TALLOC (num_regs, CONST char *);
+old_regstart = REGEX_TALLOC (num_regs, CONST char *);
+old_regend = REGEX_TALLOC (num_regs, CONST char *);
+best_regstart = REGEX_TALLOC (num_regs, CONST char *);
+best_regend = REGEX_TALLOC (num_regs, CONST char *);
+reg_info = REGEX_TALLOC (num_regs, register_info_type);
+reg_dummy = REGEX_TALLOC (num_regs, CONST char *);
+reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
+if (!(regstart && regend && old_regstart && old_regend && reg_info
+&& best_regstart && best_regend && reg_dummy && reg_info_dummy))
+{
+FREE_VARIABLES ();
+return -2;
+}
+}
+else
+{
+/* We must initialize all our variables to NULL, so that
+`FREE_VARIABLES' doesn't try to free them.  */
+regstart = regend = old_regstart = old_regend = best_regstart
+= best_regend = reg_dummy = NULL;
+reg_info = reg_info_dummy = (register_info_type *) NULL;
+}
+#endif /* MATCH_MAY_ALLOCATE */
+/* The starting position is bogus.  */
+if (pos < 0 || pos > size1 + size2)
+{
+FREE_VARIABLES ();
+return -1;
+}
+/* Initialize subexpression text positions to -1 to mark ones that no
+start_memory/stop_memory has been seen for. Also initialize the
+register information struct.  */
+for (mcnt = 1; mcnt < num_regs; mcnt++)
+{
+regstart[mcnt] = regend[mcnt]
+= old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
+REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
+IS_ACTIVE (reg_info[mcnt]) = 0;
+MATCHED_SOMETHING (reg_info[mcnt]) = 0;
+EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
+}
+/* We move `string1' into `string2' if the latter's empty -- but not if
+`string1' is null.  */
+if (size2 == 0 && string1 != NULL)
+{
+string2 = string1;
+size2 = size1;
+string1 = 0;
+size1 = 0;
+}
+end1 = string1 + size1;
+end2 = string2 + size2;
+/* Compute where to stop matching, within the two strings.  */
+if (stop <= size1)
+{
+end_match_1 = string1 + stop;
+end_match_2 = string2;
+}
+else
+{
+end_match_1 = end1;
+end_match_2 = string2 + stop - size1;
+}
+/* `p' scans through the pattern as `d' scans through the data.
+`dend' is the end of the input string that `d' points within.  `d'
+is advanced into the following input string whenever necessary, but
+this happens before fetching; therefore, at the beginning of the
+loop, `d' can be pointing at the end of a string, but it cannot
+equal `string2'.  */
+if (size1 > 0 && pos <= size1)
+{
+d = string1 + pos;
+dend = end_match_1;
+}
+else
+{
+d = string2 + pos - size1;
+dend = end_match_2;
+}
+DEBUG_PRINT1 ("The compiled pattern is: ");
+DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
+DEBUG_PRINT1 ("The string to match is: `");
+DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
+DEBUG_PRINT1 ("'\n");
+/* This loops over pattern commands.  It exits by returning from the
+function if the match is complete, or it drops through if the match
+fails at this starting point in the input data.  */
+for (;;)
+{
+DEBUG_PRINT2 ("\n0x%lx: ", (unsigned long) p);
+if (p == pend)
+	{ /* End of pattern means we might have succeeded.  */
+DEBUG_PRINT1 ("end of pattern ... ");
+	  /* If we haven't matched the entire string, and we want the
+longest match, try backtracking.  */
+if (d != end_match_2)
+	    {
+	      /* 1 if this match ends in the same string (string1 or string2)
+		 as the best previous match.  */
+	      boolean same_str_p = (FIRST_STRING_P (match_end)
+				    == MATCHING_IN_FIRST_STRING);
+	      /* 1 if this match is the best seen so far.  */
+	      boolean best_match_p;
+	      /* AIX compiler got confused when this was combined
+		 with the previous declaration.  */
+	      if (same_str_p)
+		best_match_p = d > match_end;
+	      else
+		best_match_p = !MATCHING_IN_FIRST_STRING;
+DEBUG_PRINT1 ("backtracking.\n");
+if (!FAIL_STACK_EMPTY ())
+{ /* More failure points to try.  */
+/* If exceeds best match so far, save it.  */
+if (!best_regs_set || best_match_p)
+{
+best_regs_set = true;
+match_end = d;
+DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
+for (mcnt = 1; mcnt < num_regs; mcnt++)
+{
+best_regstart[mcnt] = regstart[mcnt];
+best_regend[mcnt] = regend[mcnt];
+}
+}
+goto fail;
+}
+/* If no failure points, don't restore garbage.  And if
+last match is real best match, don't restore second
+best one. */
+else if (best_regs_set && !best_match_p)
+{
+	        restore_best_regs:
+/* Restore best match.  It may happen that `dend ==
+end_match_1' while the restored d is in string2.
+For example, the pattern `x.*y.*z' against the
+strings `x-' and `y-z-', if the two strings are
+not consecutive in memory.  */
+DEBUG_PRINT1 ("Restoring best registers.\n");
+d = match_end;
+dend = ((d >= string1 && d <= end1)
+		           ? end_match_1 : end_match_2);
+		  for (mcnt = 1; mcnt < num_regs; mcnt++)
+		    {
+		      regstart[mcnt] = best_regstart[mcnt];
+		      regend[mcnt] = best_regend[mcnt];
+		    }
+}
+} /* d != end_match_2 */
+	succeed_label:
+DEBUG_PRINT1 ("Accepting match.\n");
+/* If caller wants register contents data back, do it.  */
+if (regs && !bufp->no_sub)
+	    {
+/* Have the register data arrays been allocated?  */
+if (bufp->regs_allocated == REGS_UNALLOCATED)
+{ /* No.  So allocate them with malloc.  We need one
+extra element beyond `num_regs' for the `-1' marker
+GNU code uses.  */
+regs->num_regs = MAX (RE_NREGS, num_regs + 1);
+regs->start = TALLOC (regs->num_regs, regoff_t);
+regs->end = TALLOC (regs->num_regs, regoff_t);
+if (regs->start == NULL || regs->end == NULL)
+		    {
+		      FREE_VARIABLES ();
+		      return -2;
+		    }
+bufp->regs_allocated = REGS_REALLOCATE;
+}
+else if (bufp->regs_allocated == REGS_REALLOCATE)
+{ /* Yes.  If we need more elements than were already
+allocated, reallocate them.  If we need fewer, just
+leave it alone.  */
+if (regs->num_regs < num_regs + 1)
+{
+regs->num_regs = num_regs + 1;
+RETALLOC (regs->start, regs->num_regs, regoff_t);
+RETALLOC (regs->end, regs->num_regs, regoff_t);
+if (regs->start == NULL || regs->end == NULL)
+			{
+			  FREE_VARIABLES ();
+			  return -2;
+			}
+}
+}
+else
+		{
+		  /* These braces fend off a "empty body in an else-statement"
+		     warning under GCC when assert expands to nothing.  */
+		  assert (bufp->regs_allocated == REGS_FIXED);
+		}
+/* Convert the pointer data in `regstart' and `regend' to
+indices.  Register zero has to be set differently,
+since we haven't kept track of any info for it.  */
+if (regs->num_regs > 0)
+{
+regs->start[0] = pos;
+regs->end[0] = (MATCHING_IN_FIRST_STRING
+				  ? ((regoff_t) (d - string1))
+			          : ((regoff_t) (d - string2 + size1)));
+}
+/* Go through the first `min (num_regs, regs->num_regs)'
+registers, since that is all we initialized.  */
+	      for (mcnt = 1; mcnt < MIN (num_regs, regs->num_regs); mcnt++)
+		{
+if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
+regs->start[mcnt] = regs->end[mcnt] = -1;
+else
+{
+		      regs->start[mcnt]
+			= (regoff_t) POINTER_TO_OFFSET (regstart[mcnt]);
+regs->end[mcnt]
+			= (regoff_t) POINTER_TO_OFFSET (regend[mcnt]);
+}
+		}
+/* If the regs structure we return has more elements than
+were in the pattern, set the extra elements to -1.  If
+we (re)allocated the registers, this is the case,
+because we always allocate enough to have at least one
+-1 at the end.  */
+for (mcnt = num_regs; mcnt < regs->num_regs; mcnt++)
+regs->start[mcnt] = regs->end[mcnt] = -1;
+	    } /* regs && !bufp->no_sub */
+DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
+nfailure_points_pushed, nfailure_points_popped,
+nfailure_points_pushed - nfailure_points_popped);
+DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
+mcnt = d - pos - (MATCHING_IN_FIRST_STRING
+			    ? string1
+			    : string2 - size1);
+DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
+FREE_VARIABLES ();
+return mcnt;
+}
+/* Otherwise match next pattern command.  */
+switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
+	{
+/* Ignore these.  Used to ignore the n of succeed_n's which
+currently have n == 0.  */
+case no_op:
+DEBUG_PRINT1 ("EXECUTING no_op.\n");
+break;
+	case succeed:
+DEBUG_PRINT1 ("EXECUTING succeed.\n");
+	  goto succeed_label;
+/* Match the next n pattern characters exactly.  The following
+byte in the pattern defines n, and the n bytes after that
+are the characters to match.  */
+	case exactn:
+	  mcnt = *p++;
+DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
+/* This is written out as an if-else so we don't waste time
+testing `translate' inside the loop.  */
+if (translate)
+	    {
+	      do
+		{
+		  PREFETCH ();
+		  if (translate[(unsigned char) *d++] != (char) *p++)
+goto fail;
+		}
+	      while (--mcnt);
+	    }
+	  else
+	    {
+	      do
+		{
+		  PREFETCH ();
+		  if (*d++ != (char) *p++) goto fail;
+		}
+	      while (--mcnt);
+	    }
+	  SET_REGS_MATCHED ();
+break;
+/* Match any character except possibly a newline or a null.  */
+	case anychar:
+DEBUG_PRINT1 ("EXECUTING anychar.\n");
+PREFETCH ();
+if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
+|| (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
+	    goto fail;
+SET_REGS_MATCHED ();
+DEBUG_PRINT2 ("  Matched `%d'.\n", *d);
+	  INC_CHARPTR (d); /* XEmacs change */
+	  break;
+	case charset:
+	case charset_not:
+	  {
+	    register unsigned char c;
+	    boolean not = (re_opcode_t) *(p - 1) == charset_not;
+DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
+	    PREFETCH ();
+	    c = TRANSLATE (*d); /* The character to match.  */
+/* Cast to `unsigned' instead of `unsigned char' in case the
+bit list is a full 32 bytes long.  */
+	    if (c < (unsigned) (*p * BYTEWIDTH)
+		&& p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
+	      not = !not;
+	    p += 1 + *p;
+	    if (!not) goto fail;
+	    SET_REGS_MATCHED ();
+d++;
+	    break;
+	  }
+/* The beginning of a group is represented by start_memory.
+The arguments are the register number in the next byte, and the
+number of groups inner to this one in the next.  The text
+matched within the group is recorded (in the internal
+registers data structure) under the register number.  */
+case start_memory:
+	  DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
+/* Find out if this group can match the empty string.  */
+	  p1 = p;		/* To send to group_match_null_string_p.  */
+if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
+REG_MATCH_NULL_STRING_P (reg_info[*p])
+= group_match_null_string_p (&p1, pend, reg_info);
+/* Save the position in the string where we were the last time
+we were at this open-group operator in case the group is
+operated upon by a repetition operator, e.g., with `(a*)*b'
+against `ab'; then we want to ignore where we are now in
+the string in case this attempt to match fails.  */
+old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
+? REG_UNSET (regstart[*p]) ? d : regstart[*p]
+: regstart[*p];
+	  DEBUG_PRINT2 ("  old_regstart: %d\n",
+			 POINTER_TO_OFFSET (old_regstart[*p]));
+regstart[*p] = d;
+	  DEBUG_PRINT2 ("  regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
+IS_ACTIVE (reg_info[*p]) = 1;
+MATCHED_SOMETHING (reg_info[*p]) = 0;
+	  /* Clear this whenever we change the register activity status.  */
+	  set_regs_matched_done = 0;
+/* This is the new highest active register.  */
+highest_active_reg = *p;
+/* If nothing was active before, this is the new lowest active
+register.  */
+if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
+lowest_active_reg = *p;
+/* Move past the register number and inner group count.  */
+p += 2;
+	  just_past_start_mem = p;
+break;
+/* The stop_memory opcode represents the end of a group.  Its
+arguments are the same as start_memory's: the register
+number, and the number of inner groups.  */
+	case stop_memory:
+	  DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
+/* We need to save the string position the last time we were at
+this close-group operator in case the group is operated
+upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
+against `aba'; then we want to ignore where we are now in
+the string in case this attempt to match fails.  */
+old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
+? REG_UNSET (regend[*p]) ? d : regend[*p]
+			   : regend[*p];
+	  DEBUG_PRINT2 ("      old_regend: %d\n",
+			 POINTER_TO_OFFSET (old_regend[*p]));
+regend[*p] = d;
+	  DEBUG_PRINT2 ("      regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
+/* This register isn't active anymore.  */
+IS_ACTIVE (reg_info[*p]) = 0;
+	  /* Clear this whenever we change the register activity status.  */
+	  set_regs_matched_done = 0;
+/* If this was the only register active, nothing is active
+anymore.  */
+if (lowest_active_reg == highest_active_reg)
+{
+lowest_active_reg = NO_LOWEST_ACTIVE_REG;
+highest_active_reg = NO_HIGHEST_ACTIVE_REG;
+}
+else
+{ /* We must scan for the new highest active register, since
+it isn't necessarily one less than now: consider
+(a(b)c(d(e)f)g).  When group 3 ends, after the f), the
+new highest active register is 1.  */
+unsigned char r = *p - 1;
+while (r > 0 && !IS_ACTIVE (reg_info[r]))
+r--;
+/* If we end up at register zero, that means that we saved
+the registers as the result of an `on_failure_jump', not
+a `start_memory', and we jumped to past the innermost
+`stop_memory'.  For example, in ((.)*) we save
+registers 1 and 2 as a result of the *, but when we pop
+back to the second ), we are at the stop_memory 1.
+Thus, nothing is active.  */
+	      if (r == 0)
+{
+lowest_active_reg = NO_LOWEST_ACTIVE_REG;
+highest_active_reg = NO_HIGHEST_ACTIVE_REG;
+}
+else
+highest_active_reg = r;
+}
+/* If just failed to match something this time around with a
+group that's operated on by a repetition operator, try to
+force exit from the ``loop'', and restore the register
+information for this group that we had before trying this
+last match.  */
+if ((!MATCHED_SOMETHING (reg_info[*p])
+|| just_past_start_mem == p - 1)
+	      && (p + 2) < pend)
+{
+boolean is_a_jump_n = false;
+p1 = p + 2;
+mcnt = 0;
+switch ((re_opcode_t) *p1++)
+{
+case jump_n:
+		    is_a_jump_n = true;
+case pop_failure_jump:
+		  case maybe_pop_jump:
+		  case jump:
+		  case dummy_failure_jump:
+EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+		    if (is_a_jump_n)
+		      p1 += 2;
+break;
+default:
+/* do nothing */ ;
+}
+	      p1 += mcnt;
+/* If the next operation is a jump backwards in the pattern
+	         to an on_failure_jump right before the start_memory
+corresponding to this stop_memory, exit from the loop
+by forcing a failure after pushing on the stack the
+on_failure_jump's jump in the pattern, and d.  */
+if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
+&& (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
+		{
+/* If this group ever matched anything, then restore
+what its registers were before trying this last
+failed match, e.g., with `(a*)*b' against `ab' for
+regstart[1], and, e.g., with `((a*)*(b*)*)*'
+against `aba' for regend[3].
+Also restore the registers for inner groups for,
+e.g., `((a*)(b*))*' against `aba' (register 3 would
+otherwise get trashed).  */
+if (EVER_MATCHED_SOMETHING (reg_info[*p]))
+		    {
+		      unsigned r;
+EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
+		      /* Restore this and inner groups' (if any) registers.  */
+for (r = *p; r < *p + *(p + 1); r++)
+{
+regstart[r] = old_regstart[r];
+/* xx why this test?  */
+if (old_regend[r] >= regstart[r])
+regend[r] = old_regend[r];
+}
+}
+		  p1++;
+EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
+goto fail;
+}
+}
+/* Move past the register number and the inner group count.  */
+p += 2;
+break;
+	/* \<digit> has been turned into a `duplicate' command which is
+followed by the numeric value of <digit> as the register number.  */
+case duplicate:
+	  {
+	    register CONST char *d2, *dend2;
+	    int regno = *p++;   /* Get which register to match against.  */
+	    DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
+	    /* Can't back reference a group which we've never matched.  */
+if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
+goto fail;
+/* Where in input to try to start matching.  */
+d2 = regstart[regno];
+/* Where to stop matching; if both the place to start and
+the place to stop matching are in the same string, then
+set to the place to stop, otherwise, for now have to use
+the end of the first string.  */
+dend2 = ((FIRST_STRING_P (regstart[regno])
+		      == FIRST_STRING_P (regend[regno]))
+		     ? regend[regno] : end_match_1);
+	    for (;;)
+	      {
+		/* If necessary, advance to next segment in register
+contents.  */
+		while (d2 == dend2)
+		  {
+		    if (dend2 == end_match_2) break;
+		    if (dend2 == regend[regno]) break;
+/* End of string1 => advance to string2. */
+d2 = string2;
+dend2 = regend[regno];
+		  }
+		/* At end of register contents => success */
+		if (d2 == dend2) break;
+		/* If necessary, advance to next segment in data.  */
+		PREFETCH ();
+		/* How many characters left in this segment to match.  */
+		mcnt = dend - d;
+		/* Want how many consecutive characters we can match in
+one shot, so, if necessary, adjust the count.  */
+if (mcnt > dend2 - d2)
+		  mcnt = dend2 - d2;
+		/* Compare that many; failure if mismatch, else move
+past them.  */
+		if (translate
+? bcmp_translate ((unsigned char *) d,
+				      (unsigned char *) d2, mcnt, translate)
+: memcmp (d, d2, mcnt))
+		  goto fail;
+		d += mcnt, d2 += mcnt;
+		/* Do this because we've match some characters.  */
+		SET_REGS_MATCHED ();
+	      }
+	  }
+	  break;
+/* begline matches the empty string at the beginning of the string
+(unless `not_bol' is set in `bufp'), and, if
+`newline_anchor' is set, after newlines.  */
+	case begline:
+DEBUG_PRINT1 ("EXECUTING begline.\n");
+if (AT_STRINGS_BEG (d))
+{
+if (!bufp->not_bol) break;
+}
+else if (d[-1] == '\n' && bufp->newline_anchor)
+{
+break;
+}
+/* In all other cases, we fail.  */
+goto fail;
+/* endline is the dual of begline.  */
+	case endline:
+DEBUG_PRINT1 ("EXECUTING endline.\n");
+if (AT_STRINGS_END (d))
+{
+if (!bufp->not_eol) break;
+}
+/* We have to ``prefetch'' the next character.  */
+else if ((d == end1 ? *string2 : *d) == '\n'
+&& bufp->newline_anchor)
+{
+break;
+}
+goto fail;
+	/* Match at the very beginning of the data.  */
+case begbuf:
+DEBUG_PRINT1 ("EXECUTING begbuf.\n");
+if (AT_STRINGS_BEG (d))
+break;
+goto fail;
+	/* Match at the very end of the data.  */
+case endbuf:
+DEBUG_PRINT1 ("EXECUTING endbuf.\n");
+	  if (AT_STRINGS_END (d))
+	    break;
+goto fail;
+/* on_failure_keep_string_jump is used to optimize `.*\n'.  It
+pushes NULL as the value for the string on the stack.  Then
+`pop_failure_point' will keep the current value for the
+string, instead of restoring it.  To see why, consider
+matching `foo\nbar' against `.*\n'.  The .* matches the foo;
+then the . fails against the \n.  But the next thing we want
+to do is match the \n against the \n; if we restored the
+string value, we would be back at the foo.
+Because this is used only in specific cases, we don't need to
+check all the things that `on_failure_jump' does, to make
+sure the right things get saved on the stack.  Hence we don't
+share its code.  The only reason to push anything on the
+stack at all is that otherwise we would have to change
+`anychar's code to do something besides goto fail in this
+case; that seems worse than this.  */
+case on_failure_keep_string_jump:
+DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
+EXTRACT_NUMBER_AND_INCR (mcnt, p);
+DEBUG_PRINT3 (" %d (to 0x%lx):\n", mcnt, (unsigned long) (p + mcnt));
+PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
+break;
+	/* Uses of on_failure_jump:
+Each alternative starts with an on_failure_jump that points
+to the beginning of the next alternative.  Each alternative
+except the last ends with a jump that in effect jumps past
+the rest of the alternatives.  (They really jump to the
+ending jump of the following alternative, because tensioning
+these jumps is a hassle.)
+Repeats start with an on_failure_jump that points past both
+the repetition text and either the following jump or
+pop_failure_jump back to this on_failure_jump.  */
+	case on_failure_jump:
+on_failure:
+DEBUG_PRINT1 ("EXECUTING on_failure_jump");
+EXTRACT_NUMBER_AND_INCR (mcnt, p);
+DEBUG_PRINT3 (" %d (to 0x%lx)", mcnt, (unsigned long) (p + mcnt));
+/* If this on_failure_jump comes right before a group (i.e.,
+the original * applied to a group), save the information
+for that group and all inner ones, so that if we fail back
+to this point, the group's information will be correct.
+For example, in \(a*\)*\1, we need the preceding group,
+and in \(\(a*\)b*\)\2, we need the inner group.  */
+/* We can't use `p' to check ahead because we push
+a failure point to `p + mcnt' after we do this.  */
+p1 = p;
+/* We need to skip no_op's before we look for the
+start_memory in case this on_failure_jump is happening as
+the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
+against aba.  */
+while (p1 < pend && (re_opcode_t) *p1 == no_op)
+p1++;
+if (p1 < pend && (re_opcode_t) *p1 == start_memory)
+{
+/* We have a new highest active register now.  This will
+get reset at the start_memory we are about to get to,
+but we will have saved all the registers relevant to
+this repetition op, as described above.  */
+highest_active_reg = *(p1 + 1) + *(p1 + 2);
+if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
+lowest_active_reg = *(p1 + 1);
+}
+DEBUG_PRINT1 (":\n");
+PUSH_FAILURE_POINT (p + mcnt, d, -2);
+break;
+/* A smart repeat ends with `maybe_pop_jump'.
+	   We change it to either `pop_failure_jump' or `jump'.  */
+case maybe_pop_jump:
+EXTRACT_NUMBER_AND_INCR (mcnt, p);
+DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
+{
+	    register unsigned char *p2 = p;
+/* Compare the beginning of the repeat with what in the
+pattern follows its end. If we can establish that there
+is nothing that they would both match, i.e., that we
+would have to backtrack because of (as in, e.g., `a*a')
+then we can change to pop_failure_jump, because we'll
+never have to backtrack.
+This is not true in the case of alternatives: in
+`(a|ab)*' we do need to backtrack to the `ab' alternative
+(e.g., if the string was `ab').  But instead of trying to
+detect that here, the alternative has put on a dummy
+failure point which is what we will end up popping.  */
+	    /* Skip over open/close-group commands.
+	       If what follows this loop is a ...+ construct,
+	       look at what begins its body, since we will have to
+	       match at least one of that.  */
+	    while (1)
+	      {
+		if (p2 + 2 < pend
+		    && ((re_opcode_t) *p2 == stop_memory
+			|| (re_opcode_t) *p2 == start_memory))
+		  p2 += 3;
+		else if (p2 + 6 < pend
+			 && (re_opcode_t) *p2 == dummy_failure_jump)
+		  p2 += 6;
+		else
+		  break;
+	      }
+	    p1 = p + mcnt;
+	    /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
+	       to the `maybe_finalize_jump' of this case.  Examine what
+	       follows.  */
+/* If we're at the end of the pattern, we can change.  */
+if (p2 == pend)
+	      {
+		/* Consider what happens when matching ":\(.*\)"
+		   against ":/".  I don't really understand this code
+		   yet.  */
+	        p[-3] = (unsigned char) pop_failure_jump;
+DEBUG_PRINT1
+("  End of pattern: change to `pop_failure_jump'.\n");
+}
+else if ((re_opcode_t) *p2 == exactn
+		     || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
+	      {
+		register unsigned char c
+= *p2 == (unsigned char) endline ? '\n' : p2[2];
+if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
+{
+		    p[-3] = (unsigned char) pop_failure_jump;
+DEBUG_PRINT3 ("  %c != %c => pop_failure_jump.\n",
+c, p1[5]);
+}
+		else if ((re_opcode_t) p1[3] == charset
+			 || (re_opcode_t) p1[3] == charset_not)
+		  {
+		    int not = (re_opcode_t) p1[3] == charset_not;
+		    if (c < (unsigned char) (p1[4] * BYTEWIDTH)
+			&& p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
+		      not = !not;
+/* `not' is equal to 1 if c would match, which means
+that we can't change to pop_failure_jump.  */
+		    if (!not)
+{
+		        p[-3] = (unsigned char) pop_failure_jump;
+DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
+}
+		  }
+	      }
+else if ((re_opcode_t) *p2 == charset)
+	      {
+#ifdef DEBUG
+		register unsigned char c
+= *p2 == (unsigned char) endline ? '\n' : p2[2];
+#endif
+if ((re_opcode_t) p1[3] == exactn
+		    && ! ((int) p2[1] * BYTEWIDTH > (int) p1[4]
+			  && (p2[1 + p1[4] / BYTEWIDTH]
+			      & (1 << (p1[4] % BYTEWIDTH)))))
+{
+		    p[-3] = (unsigned char) pop_failure_jump;
+DEBUG_PRINT3 ("  %c != %c => pop_failure_jump.\n",
+c, p1[5]);
+}
+		else if ((re_opcode_t) p1[3] == charset_not)
+		  {
+		    int idx;
+		    /* We win if the charset_not inside the loop
+		       lists every character listed in the charset after.  */
+		    for (idx = 0; idx < (int) p2[1]; idx++)
+		      if (! (p2[2 + idx] == 0
+			     || (idx < (int) p1[4]
+				 && ((p2[2 + idx] & ~ p1[5 + idx]) == 0))))
+			break;
+		    if (idx == p2[1])
+{
+		        p[-3] = (unsigned char) pop_failure_jump;
+DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
+}
+		  }
+		else if ((re_opcode_t) p1[3] == charset)
+		  {
+		    int idx;
+		    /* We win if the charset inside the loop
+		       has no overlap with the one after the loop.  */
+		    for (idx = 0;
+			 idx < (int) p2[1] && idx < (int) p1[4];
+			 idx++)
+		      if ((p2[2 + idx] & p1[5 + idx]) != 0)
+			break;
+		    if (idx == p2[1] || idx == p1[4])
+{
+		        p[-3] = (unsigned char) pop_failure_jump;
+DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
+}
+		  }
+	      }
+	  }
+	  p -= 2;		/* Point at relative address again.  */
+	  if ((re_opcode_t) p[-1] != pop_failure_jump)
+	    {
+	      p[-1] = (unsigned char) jump;
+DEBUG_PRINT1 ("  Match => jump.\n");
+	      goto unconditional_jump;
+	    }
+/* Note fall through.  */
+	/* The end of a simple repeat has a pop_failure_jump back to
+its matching on_failure_jump, where the latter will push a
+failure point.  The pop_failure_jump takes off failure
+points put on by this pop_failure_jump's matching
+on_failure_jump; we got through the pattern to here from the
+matching on_failure_jump, so didn't fail.  */
+case pop_failure_jump:
+{
+/* We need to pass separate storage for the lowest and
+highest registers, even though we don't care about the
+actual values.  Otherwise, we will restore only one
+register from the stack, since lowest will == highest in
+`pop_failure_point'.  */
+unsigned dummy_low_reg, dummy_high_reg;
+unsigned char *pdummy;
+CONST char *sdummy;
+DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
+POP_FAILURE_POINT (sdummy, pdummy,
+dummy_low_reg, dummy_high_reg,
+reg_dummy, reg_dummy, reg_info_dummy);
+}
+/* Note fall through.  */
+/* Unconditionally jump (without popping any failure points).  */
+case jump:
+	unconditional_jump:
+	  EXTRACT_NUMBER_AND_INCR (mcnt, p);	/* Get the amount to jump.  */
+DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
+	  p += mcnt;				/* Do the jump.  */
+DEBUG_PRINT2 ("(to 0x%lx).\n", (unsigned long) p);
+	  break;
+/* We need this opcode so we can detect where alternatives end
+in `group_match_null_string_p' et al.  */
+case jump_past_alt:
+DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
+goto unconditional_jump;
+/* Normally, the on_failure_jump pushes a failure point, which
+then gets popped at pop_failure_jump.  We will end up at
+pop_failure_jump, also, and with a pattern of, say, `a+', we
+are skipping over the on_failure_jump, so we have to push
+something meaningless for pop_failure_jump to pop.  */
+case dummy_failure_jump:
+DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
+/* It doesn't matter what we push for the string here.  What
+the code at `fail' tests is the value for the pattern.  */
+PUSH_FAILURE_POINT (0, 0, -2);
+goto unconditional_jump;
+/* At the end of an alternative, we need to push a dummy failure
+point in case we are followed by a `pop_failure_jump', because
+we don't want the failure point for the alternative to be
+popped.  For example, matching `(a|ab)*' against `aab'
+requires that we match the `ab' alternative.  */
+case push_dummy_failure:
+DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
+/* See comments just above at `dummy_failure_jump' about the
+two zeroes.  */
+PUSH_FAILURE_POINT (0, 0, -2);
+break;
+/* Have to succeed matching what follows at least n times.
+After that, handle like `on_failure_jump'.  */
+case succeed_n:
+EXTRACT_NUMBER (mcnt, p + 2);
+DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
+assert (mcnt >= 0);
+/* Originally, this is how many times we HAVE to succeed.  */
+if (mcnt > 0)
+{
+mcnt--;
+	       p += 2;
+STORE_NUMBER_AND_INCR (p, mcnt);
+DEBUG_PRINT3 ("  Setting 0x%lx to %d.\n", (unsigned long) p,
+			     mcnt);
+}
+	  else if (mcnt == 0)
+{
+DEBUG_PRINT2 ("  Setting two bytes from 0x%lx to no_op.\n",
+			    (unsigned long) p+2);
+	      p[2] = (unsigned char) no_op;
+p[3] = (unsigned char) no_op;
+goto on_failure;
+}
+break;
+case jump_n:
+EXTRACT_NUMBER (mcnt, p + 2);
+DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
+/* Originally, this is how many times we CAN jump.  */
+if (mcnt)
+{
+mcnt--;
+STORE_NUMBER (p + 2, mcnt);
+	       goto unconditional_jump;
+}
+/* If don't have to jump any more, skip over the rest of command.  */
+	  else
+	    p += 4;
+break;
+	case set_number_at:
+	  {
+DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
+EXTRACT_NUMBER_AND_INCR (mcnt, p);
+p1 = p + mcnt;
+EXTRACT_NUMBER_AND_INCR (mcnt, p);
+DEBUG_PRINT3 ("  Setting 0x%lx to %d.\n", (unsigned long) p1,
+			  mcnt);
+	    STORE_NUMBER (p1, mcnt);
+break;
+}
+case wordbound:
+DEBUG_PRINT1 ("EXECUTING wordbound.\n");
+	  should_succeed = 1;
+	matchwordbound:
+	  {
+	    /* XEmacs change */
+	    int result;
+	    if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
+	      result = 1;
+	    else
+	      {
+		CONST unsigned char *d_before =
+		  (CONST unsigned char *) POS_BEFORE_GAP_UNSAFE (d);
+		CONST unsigned char *d_after =
+		  (CONST unsigned char *) POS_AFTER_GAP_UNSAFE (d);
+		Emchar emch1, emch2;
+		DEC_CHARPTR (d_before);
+		emch1 = charptr_emchar (d_before);
+		emch2 = charptr_emchar (d_after);
+		result = (WORDCHAR_P_UNSAFE (emch1) !=
+			  WORDCHAR_P_UNSAFE (emch2));
+	      }
+	    if (result == should_succeed)
+	      break;
+	    goto fail;
+	  }
+	case notwordbound:
+DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
+	  should_succeed = 0;
+	  goto matchwordbound;
+	case wordbeg:
+DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
+	  {
+	    /* XEmacs: this originally read:
+	    if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
+	      break;
+	      */
+	    CONST unsigned char *dtmp =
+	      (CONST unsigned char *) POS_AFTER_GAP_UNSAFE (d);
+	    Emchar emch = charptr_emchar (dtmp);
+	    if (!WORDCHAR_P_UNSAFE (emch))
+	      goto fail;
+	    if (AT_STRINGS_BEG (d))
+	      break;
+	    dtmp = (CONST unsigned char *) POS_BEFORE_GAP_UNSAFE (d);
+	    DEC_CHARPTR (dtmp);
+	    emch = charptr_emchar (dtmp);
+	    if (!WORDCHAR_P_UNSAFE (emch))
+	      break;
+	    goto fail;
+	  }
+	case wordend:
+DEBUG_PRINT1 ("EXECUTING wordend.\n");
+	  {
+	    /* XEmacs: this originally read:
+	    if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
+		&& (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
+	      break;
+	      The or condition is incorrect (reversed).
+	      */
+	    CONST unsigned char *dtmp;
+	    Emchar emch;
+	    if (AT_STRINGS_BEG (d))
+	      goto fail;
+	    dtmp = (CONST unsigned char *) POS_BEFORE_GAP_UNSAFE (d);
+	    DEC_CHARPTR (dtmp);
+	    emch = charptr_emchar (dtmp);
+	    if (!WORDCHAR_P_UNSAFE (emch))
+	      goto fail;
+	    if (AT_STRINGS_END (d))
+	      break;
+	    dtmp = (CONST unsigned char *) POS_AFTER_GAP_UNSAFE (d);
+	    emch = charptr_emchar (dtmp);
+	    if (!WORDCHAR_P_UNSAFE (emch))
+	      break;
+	    goto fail;
+	  }
+#ifdef emacs
+	case before_dot:
+DEBUG_PRINT1 ("EXECUTING before_dot.\n");
+	  if (BUF_PTR_BYTE_POS (regex_emacs_buffer, (unsigned char *) d) >=
+	      BUF_PT (regex_emacs_buffer))
+	    goto fail;
+	  break;
+	case at_dot:
+DEBUG_PRINT1 ("EXECUTING at_dot.\n");
+	  if (BUF_PTR_BYTE_POS (regex_emacs_buffer, (unsigned char *) d)
+	      != BUF_PT (regex_emacs_buffer))
+	    goto fail;
+	  break;
+	case after_dot:
+DEBUG_PRINT1 ("EXECUTING after_dot.\n");
+if (BUF_PTR_BYTE_POS (regex_emacs_buffer, (unsigned char *) d)
+	      <= BUF_PT (regex_emacs_buffer))
+	    goto fail;
+	  break;
+#if 0 /* not emacs19 */
+	case at_dot:
+DEBUG_PRINT1 ("EXECUTING at_dot.\n");
+	  if (BUF_PTR_BYTE_POS (regex_emacs_buffer, (unsigned char *) d) + 1
+	      != BUF_PT (regex_emacs_buffer))
+	    goto fail;
+	  break;
+#endif /* not emacs19 */
+	case syntaxspec:
+DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
+	  mcnt = *p++;
+	  goto matchsyntax;
+case wordchar:
+DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
+	  mcnt = (int) Sword;
+matchsyntax:
+	  should_succeed = 1;
+	matchornotsyntax:
+	  {
+	    int matches;
+	    Emchar emch;
+	    PREFETCH ();
+	    emch = charptr_emchar ((CONST Bufbyte *) d);
+	    matches = (SYNTAX_UNSAFE (regex_emacs_buffer->syntax_table,
+				      emch) == (enum syntaxcode) mcnt);
+	    INC_CHARPTR (d);
+	    if (matches != should_succeed)
+	      goto fail;
+	    SET_REGS_MATCHED ();
+	  }
+	  break;
+	case notsyntaxspec:
+DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
+	  mcnt = *p++;
+	  goto matchnotsyntax;
+case notwordchar:
+DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
+	  mcnt = (int) Sword;
+matchnotsyntax:
+	  should_succeed = 0;
+	  goto matchornotsyntax;
+#else /* not emacs */
+	case wordchar:
+DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
+	  PREFETCH ();
+if (!WORDCHAR_P_UNSAFE ((int) (*d)))
+goto fail;
+	  SET_REGS_MATCHED ();
+d++;
+	  break;
+	case notwordchar:
+DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
+	  PREFETCH ();
+if (!WORDCHAR_P_UNSAFE ((int) (*d)))
+goto fail;
+SET_REGS_MATCHED ();
+d++;
+	  break;
+#endif /* not emacs */
+default:
+abort ();
+	}
+continue;  /* Successfully executed one pattern command; keep going.  */
+/* We goto here if a matching operation fails. */
+fail:
+if (!FAIL_STACK_EMPTY ())
+	{ /* A restart point is known.  Restore to that state.  */
+DEBUG_PRINT1 ("\nFAIL:\n");
+POP_FAILURE_POINT (d, p,
+lowest_active_reg, highest_active_reg,
+regstart, regend, reg_info);
+/* If this failure point is a dummy, try the next one.  */
+if (!p)
+	    goto fail;
+/* If we failed to the end of the pattern, don't examine *p.  */
+	  assert (p <= pend);
+if (p < pend)
+{
+boolean is_a_jump_n = false;
+/* If failed to a backwards jump that's part of a repetition
+loop, need to pop this failure point and use the next one.  */
+switch ((re_opcode_t) *p)
+{
+case jump_n:
+is_a_jump_n = true;
+case maybe_pop_jump:
+case pop_failure_jump:
+case jump:
+p1 = p + 1;
+EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+p1 += mcnt;
+if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
+|| (!is_a_jump_n
+&& (re_opcode_t) *p1 == on_failure_jump))
+goto fail;
+break;
+default:
+/* do nothing */ ;
+}
+}
+if (d >= string1 && d <= end1)
+	    dend = end_match_1;
+}
+else
+break;   /* Matching at this starting point really fails.  */
+} /* for (;;) */
+if (best_regs_set)
+goto restore_best_regs;
+FREE_VARIABLES ();
+return -1;         			/* Failure to match.  */
+} /* re_match_2 */
+/* Subroutine definitions for re_match_2.  */
+/* We are passed P pointing to a register number after a start_memory.
+Return true if the pattern up to the corresponding stop_memory can
+match the empty string, and false otherwise.
+If we find the matching stop_memory, sets P to point to one past its number.
+Otherwise, sets P to an undefined byte less than or equal to END.
+We don't handle duplicates properly (yet).  */
+static boolean
+group_match_null_string_p (unsigned char **p, unsigned char *end,
+			   register_info_type *reg_info)
+{
+int mcnt;
+/* Point to after the args to the start_memory.  */
+unsigned char *p1 = *p + 2;
+while (p1 < end)
+{
+/* Skip over opcodes that can match nothing, and return true or
+	 false, as appropriate, when we get to one that can't, or to the
+matching stop_memory.  */
+switch ((re_opcode_t) *p1)
+{
+/* Could be either a loop or a series of alternatives.  */
+case on_failure_jump:
+p1++;
+EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+/* If the next operation is not a jump backwards in the
+	     pattern.  */
+	  if (mcnt >= 0)
+	    {
+/* Go through the on_failure_jumps of the alternatives,
+seeing if any of the alternatives cannot match nothing.
+The last alternative starts with only a jump,
+whereas the rest start with on_failure_jump and end
+with a jump, e.g., here is the pattern for `a|b|c':
+/on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
+/on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
+/exactn/1/c
+So, we have to first go through the first (n-1)
+alternatives and then deal with the last one separately.  */
+/* Deal with the first (n-1) alternatives, which start
+with an on_failure_jump (see above) that jumps to right
+past a jump_past_alt.  */
+while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
+{
+/* `mcnt' holds how many bytes long the alternative
+is, including the ending `jump_past_alt' and
+its number.  */
+if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
+				                      reg_info))
+return false;
+/* Move to right after this alternative, including the
+		     jump_past_alt.  */
+p1 += mcnt;
+/* Break if it's the beginning of an n-th alternative
+that doesn't begin with an on_failure_jump.  */
+if ((re_opcode_t) *p1 != on_failure_jump)
+break;
+		  /* Still have to check that it's not an n-th
+		     alternative that starts with an on_failure_jump.  */
+		  p1++;
+EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
+{
+		      /* Get to the beginning of the n-th alternative.  */
+p1 -= 3;
+break;
+}
+}
+/* Deal with the last alternative: go back and get number
+of the `jump_past_alt' just before it.  `mcnt' contains
+the length of the alternative.  */
+EXTRACT_NUMBER (mcnt, p1 - 2);
+if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
+return false;
+p1 += mcnt;	/* Get past the n-th alternative.  */
+} /* if mcnt > 0 */
+break;
+case stop_memory:
+	  assert (p1[1] == **p);
+*p = p1 + 2;
+return true;
+default:
+if (!common_op_match_null_string_p (&p1, end, reg_info))
+return false;
+}
+} /* while p1 < end */
+return false;
+} /* group_match_null_string_p */
+/* Similar to group_match_null_string_p, but doesn't deal with alternatives:
+It expects P to be the first byte of a single alternative and END one
+byte past the last. The alternative can contain groups.  */
+static boolean
+alt_match_null_string_p (unsigned char *p, unsigned char *end,
+			 register_info_type *reg_info)
+{
+int mcnt;
+unsigned char *p1 = p;
+while (p1 < end)
+{
+/* Skip over opcodes that can match nothing, and break when we get
+to one that can't.  */
+switch ((re_opcode_t) *p1)
+{
+	/* It's a loop.  */
+case on_failure_jump:
+p1++;
+EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+p1 += mcnt;
+break;
+	default:
+if (!common_op_match_null_string_p (&p1, end, reg_info))
+return false;
+}
+}  /* while p1 < end */
+return true;
+} /* alt_match_null_string_p */
+/* Deals with the ops common to group_match_null_string_p and
+alt_match_null_string_p.
+Sets P to one after the op and its arguments, if any.  */
+static boolean
+common_op_match_null_string_p (unsigned char **p, unsigned char *end,
+			       register_info_type *reg_info)
+{
+int mcnt;
+boolean ret;
+int reg_no;
+unsigned char *p1 = *p;
+switch ((re_opcode_t) *p1++)
+{
+case no_op:
+case begline:
+case endline:
+case begbuf:
+case endbuf:
+case wordbeg:
+case wordend:
+case wordbound:
+case notwordbound:
+#ifdef emacs
+case before_dot:
+case at_dot:
+case after_dot:
+#endif
+break;
+case start_memory:
+reg_no = *p1;
+assert (reg_no > 0 && reg_no <= MAX_REGNUM);
+ret = group_match_null_string_p (&p1, end, reg_info);
+/* Have to set this here in case we're checking a group which
+contains a group and a back reference to it.  */
+if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
+REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
+if (!ret)
+return false;
+break;
+/* If this is an optimized succeed_n for zero times, make the jump.  */
+case jump:
+EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+if (mcnt >= 0)
+p1 += mcnt;
+else
+return false;
+break;
+case succeed_n:
+/* Get to the number of times to succeed.  */
+p1 += 2;
+EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+if (mcnt == 0)
+{
+p1 -= 4;
+EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+p1 += mcnt;
+}
+else
+return false;
+break;
+case duplicate:
+if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
+return false;
+break;
+case set_number_at:
+p1 += 4;
+default:
+/* All other opcodes mean we cannot match the empty string.  */
+return false;
+}
+*p = p1;
+return true;
+} /* common_op_match_null_string_p */
+/* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
+bytes; nonzero otherwise.  */
+static int
+bcmp_translate (CONST unsigned char *s1, CONST unsigned char *s2,
+		register int len, char *translate)
+{
+register CONST unsigned char *p1 = s1, *p2 = s2;
+while (len)
+{
+if (translate[*p1++] != translate[*p2++]) return 1;
+len--;
+}
+return 0;
+}
+/* Entry points for GNU code.  */
+/* re_compile_pattern is the GNU regular expression compiler: it
+compiles PATTERN (of length SIZE) and puts the result in BUFP.
+Returns 0 if the pattern was valid, otherwise an error string.
+Assumes the `allocated' (and perhaps `buffer') and `translate' fields
+are set in BUFP on entry.
+We call regex_compile to do the actual compilation.  */
+CONST char *
+re_compile_pattern (CONST char *pattern, int length,
+		    struct re_pattern_buffer *bufp)
+{
+reg_errcode_t ret;
+/* GNU code is written to assume at least RE_NREGS registers will be set
+(and at least one extra will be -1).  */
+bufp->regs_allocated = REGS_UNALLOCATED;
+/* And GNU code determines whether or not to get register information
+by passing null for the REGS argument to re_match, etc., not by
+setting no_sub.  */
+bufp->no_sub = 0;
+/* Match anchors at newline.  */
+bufp->newline_anchor = 1;
+ret = regex_compile (pattern, length, re_syntax_options, bufp);
+if (!ret)
+return NULL;
+return gettext (re_error_msgid[(int) ret]);
+}
+/* Entry points compatible with 4.2 BSD regex library.  We don't define
+them unless specifically requested.  */
+#ifdef _REGEX_RE_COMP
+/* BSD has one and only one pattern buffer.  */
+static struct re_pattern_buffer re_comp_buf;
+char *
+re_comp (CONST char *s)
+{
+reg_errcode_t ret;
+if (!s)
+{
+if (!re_comp_buf.buffer)
+	return gettext ("No previous regular expression");
+return 0;
+}
+if (!re_comp_buf.buffer)
+{
+re_comp_buf.buffer = (unsigned char *) malloc (200);
+if (re_comp_buf.buffer == NULL)
+return gettext (re_error_msgid[(int) REG_ESPACE]);
+re_comp_buf.allocated = 200;
+re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
+if (re_comp_buf.fastmap == NULL)
+	return gettext (re_error_msgid[(int) REG_ESPACE]);
+}
+/* Since `re_exec' always passes NULL for the `regs' argument, we
+don't need to initialize the pattern buffer fields which affect it.  */
+/* Match anchors at newlines.  */
+re_comp_buf.newline_anchor = 1;
+ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
+if (!ret)
+return NULL;
+/* Yes, we're discarding `CONST' here if !HAVE_LIBINTL.  */
+return (char *) gettext (re_error_msgid[(int) ret]);
+}
+int
+re_exec (CONST char *s)
+{
+CONST int len = strlen (s);
+return
+0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
+}
+#endif /* _REGEX_RE_COMP */
+/* POSIX.2 functions.  Don't define these for Emacs.  */
+#ifndef emacs
+/* regcomp takes a regular expression as a string and compiles it.
+PREG is a regex_t *.  We do not expect any fields to be initialized,
+since POSIX says we shouldn't.  Thus, we set
+`buffer' to the compiled pattern;
+`used' to the length of the compiled pattern;
+`syntax' to RE_SYNTAX_POSIX_EXTENDED if the
+REG_EXTENDED bit in CFLAGS is set; otherwise, to
+RE_SYNTAX_POSIX_BASIC;
+`newline_anchor' to REG_NEWLINE being set in CFLAGS;
+`fastmap' and `fastmap_accurate' to zero;
+`re_nsub' to the number of subexpressions in PATTERN.
+PATTERN is the address of the pattern string.
+CFLAGS is a series of bits which affect compilation.
+If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
+use POSIX basic syntax.
+If REG_NEWLINE is set, then . and [^...] don't match newline.
+Also, regexec will try a match beginning after every newline.
+If REG_ICASE is set, then we considers upper- and lowercase
+versions of letters to be equivalent when matching.
+If REG_NOSUB is set, then when PREG is passed to regexec, that
+routine will report only success or failure, and nothing about the
+registers.
+It returns 0 if it succeeds, nonzero if it doesn't.  (See regex.h for
+the return codes and their meanings.)  */
+int
+regcomp (regex_t *preg, CONST char *pattern, int cflags)
+{
+reg_errcode_t ret;
+unsigned syntax
+= (cflags & REG_EXTENDED) ?
+RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
+/* regex_compile will allocate the space for the compiled pattern.  */
+preg->buffer = 0;
+preg->allocated = 0;
+preg->used = 0;
+/* Don't bother to use a fastmap when searching.  This simplifies the
+REG_NEWLINE case: if we used a fastmap, we'd have to put all the
+characters after newlines into the fastmap.  This way, we just try
+every character.  */
+preg->fastmap = 0;
+if (cflags & REG_ICASE)
+{
+unsigned i;
+preg->translate = (char *) malloc (CHAR_SET_SIZE);
+if (preg->translate == NULL)
+return (int) REG_ESPACE;
+/* Map uppercase characters to corresponding lowercase ones.  */
+for (i = 0; i < CHAR_SET_SIZE; i++)
+preg->translate[i] = ISUPPER (i) ? tolower (i) : i;
+}
+else
+preg->translate = NULL;
+/* If REG_NEWLINE is set, newlines are treated differently.  */
+if (cflags & REG_NEWLINE)
+{ /* REG_NEWLINE implies neither . nor [^...] match newline.  */
+syntax &= ~RE_DOT_NEWLINE;
+syntax |= RE_HAT_LISTS_NOT_NEWLINE;
+/* It also changes the matching behavior.  */
+preg->newline_anchor = 1;
+}
+else
+preg->newline_anchor = 0;
+preg->no_sub = !!(cflags & REG_NOSUB);
+/* POSIX says a null character in the pattern terminates it, so we
+can use strlen here in compiling the pattern.  */
+ret = regex_compile (pattern, strlen (pattern), syntax, preg);
+/* POSIX doesn't distinguish between an unmatched open-group and an
+unmatched close-group: both are REG_EPAREN.  */
+if (ret == REG_ERPAREN) ret = REG_EPAREN;
+return (int) ret;
+}
+/* regexec searches for a given pattern, specified by PREG, in the
+string STRING.
+If NMATCH is zero or REG_NOSUB was set in the cflags argument to
+`regcomp', we ignore PMATCH.  Otherwise, we assume PMATCH has at
+least NMATCH elements, and we set them to the offsets of the
+corresponding matched substrings.
+EFLAGS specifies `execution flags' which affect matching: if
+REG_NOTBOL is set, then ^ does not match at the beginning of the
+string; if REG_NOTEOL is set, then $ does not match at the end.
+We return 0 if we find a match and REG_NOMATCH if not.  */
+int
+regexec (CONST regex_t *preg, CONST char *string, size_t nmatch,
+	 regmatch_t pmatch[], int eflags)
+{
+int ret;
+struct re_registers regs;
+regex_t private_preg;
+int len = strlen (string);
+boolean want_reg_info = !preg->no_sub && nmatch > 0;
+private_preg = *preg;
+private_preg.not_bol = !!(eflags & REG_NOTBOL);
+private_preg.not_eol = !!(eflags & REG_NOTEOL);
+/* The user has told us exactly how many registers to return
+information about, via `nmatch'.  We have to pass that on to the
+matching routines.  */
+private_preg.regs_allocated = REGS_FIXED;
+if (want_reg_info)
+{
+regs.num_regs = nmatch;
+regs.start = TALLOC (nmatch, regoff_t);
+regs.end = TALLOC (nmatch, regoff_t);
+if (regs.start == NULL || regs.end == NULL)
+return (int) REG_NOMATCH;
+}
+/* Perform the searching operation.  */
+ret = re_search (&private_preg, string, len,
+/* start: */ 0, /* range: */ len,
+want_reg_info ? &regs : (struct re_registers *) 0);
+/* Copy the register information to the POSIX structure.  */
+if (want_reg_info)
+{
+if (ret >= 0)
+{
+unsigned r;
+for (r = 0; r < nmatch; r++)
+{
+pmatch[r].rm_so = regs.start[r];
+pmatch[r].rm_eo = regs.end[r];
+}
+}
+/* If we needed the temporary register info, free the space now.  */
+free (regs.start);
+free (regs.end);
+}
+/* We want zero return to mean success, unlike `re_search'.  */
+return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
+}
+/* Returns a message corresponding to an error code, ERRCODE, returned
+from either regcomp or regexec.   We don't use PREG here.  */
+size_t
+regerror (int errcode, CONST regex_t *preg, char *errbuf, size_t errbuf_size)
+{
+CONST char *msg;
+size_t msg_size;
+if (errcode < 0
+|| errcode >= (sizeof (re_error_msgid) / sizeof (re_error_msgid[0])))
+/* Only error codes returned by the rest of the code should be passed
+to this routine.  If we are given anything else, or if other regex
+code generates an invalid error code, then the program has a bug.
+Dump core so we can fix it.  */
+abort ();
+msg = gettext (re_error_msgid[errcode]);
+msg_size = strlen (msg) + 1; /* Includes the null.  */
+if (errbuf_size != 0)
+{
+if (msg_size > errbuf_size)
+{
+strncpy (errbuf, msg, errbuf_size - 1);
+errbuf[errbuf_size - 1] = 0;
+}
+else
+strcpy (errbuf, msg);
+}
+return msg_size;
+}
+/* Free dynamically allocated space used by PREG.  */
+void
+regfree (regex_t *preg)
+{
+if (preg->buffer != NULL)
+free (preg->buffer);
+preg->buffer = NULL;
+preg->allocated = 0;
+preg->used = 0;
+if (preg->fastmap != NULL)
+free (preg->fastmap);
+preg->fastmap = NULL;
+preg->fastmap_accurate = 0;
+if (preg->translate != NULL)
+free (preg->translate);
+preg->translate = NULL;
+}
+#endif /* not emacs  */
+/*
+Local variables:
+make-backup-files: t
+version-control: t
+trim-versions-without-asking: nil
+End:
+*/

Mercurial > hg > xemacs-beta

comparison src/regex.c @ 0:376386a54a3c r19-14