/* Definitions for data structures and routines for the regular
   expression library, version 0.12.

   Copyright (C) 1985, 89, 90, 91, 92, 93, 95 Free Software Foundation, Inc.
   Copyright (C) 2002, 2010 Ben Wing.

   This file is part of XEmacs.
   
   XEmacs is free software: you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation, either version 3 of the License, or (at your
   option) any later version.
   
   XEmacs 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 XEmacs.  If not, see <http://www.gnu.org/licenses/>. */
/* Synched up with: FSF 19.29. */

#ifndef INCLUDED_regex_h_
#define INCLUDED_regex_h_

#ifdef emacs
#define RE_TRANSLATE_TYPE Lisp_Object
#define RE_LISP_SHORT_CONTEXT_ARGS_DECL , Lisp_Object UNUSED (lispobj), struct buffer *UNUSED (lispbuf)
#define RE_LISP_SHORT_CONTEXT_ARGS , lispobj, lispbuf
#define RE_LISP_CONTEXT_ARGS_DECL , Lisp_Object lispobj, struct buffer *lispbuf, struct syntax_cache *scache
#define RE_LISP_CONTEXT_ARGS , lispobj, lispbuf, scache
#define RE_ISWCTYPE_ARG_DECL , struct buffer *lispbuf
#define RE_ISWCTYPE_ARG(varname) , varname
#define RE_EXECUTE_CHARSET_MULE_ARGS_DECL , RE_TRANSLATE_TYPE translate, \
	   struct buffer *lispbuf
#define RE_EXECUTE_CHARSET_MULE_ARGS(translate, lispbuf) , translate, lispbuf
#else
#define RE_TRANSLATE_TYPE char *
#define RE_LISP_SHORT_CONTEXT_ARGS_DECL
#define RE_LISP_SHORT_CONTEXT_ARGS
#define RE_LISP_CONTEXT_ARGS_DECL
#define RE_LISP_CONTEXT_ARGS
#define RE_ISWCTYPE_ARG_DECL 
#define RE_ISWCTYPE_ARG(varname)
#define RE_EXECUTE_CHARSET_MULE_ARGS_DECL , RE_TRANSLATE_TYPE translate
#define RE_EXECUTE_CHARSET_MULE_ARGS(translate, lispbuf) , translate

#define Elemcount ssize_t
#define Bytecount ssize_t
#define Bytebpos ssize_t
#endif /* emacs */

#ifndef emacs
# ifdef __cplusplus
#  define BEGIN_C_DECLS extern "C" {
#  define END_C_DECLS }
# else
#  define BEGIN_C_DECLS
#  define END_C_DECLS
# endif
#endif /* emacs */

BEGIN_C_DECLS

/* POSIX says that <sys/types.h> must be included (by the caller) before
   <regex.h>.  */


/* The following bits are used to determine the regexp syntax we
   recognize.  The not-set meaning typically corresponds to the syntax
   used by Emacs (the exception is RE_INTERVALS, made for historical
   reasons).  The bits are given in alphabetical order, and the
   definitions shifted by one from the previous bit; thus, when we add or
   remove a bit, only one other definition need change.  */
typedef unsigned reg_syntax_t;

/* If this bit is set, then character classes are supported.  They are:
     [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
     [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
   If not set, then character classes are not supported.  */
#define RE_CHAR_CLASSES (1)

/* If this bit is set, then . matches newline.
   If not set, then it doesn't.  */
#define RE_DOT_NEWLINE (RE_CHAR_CLASSES << 1)

/* If this bit is set, either \{...\} or {...} defines an
     interval, depending on RE_NO_BK_BRACES.
   If not set, \{, \}, {, and } are literals.  */
#define RE_INTERVALS (RE_DOT_NEWLINE << 1)

/* If this bit is set, succeed as soon as we match the whole pattern,
   without further backtracking.  */
#define RE_NO_POSIX_BACKTRACKING (RE_INTERVALS << 1)

/* If this bit is set, then \22 will read as a back reference,
   provided at least 22 non-shy groups have been seen so far.  In all
   other cases (bit not set, not 22 non-shy groups seen so far), it
   reads as a back reference \2 followed by a digit 2. */
#define RE_NO_MULTI_DIGIT_BK_REFS (RE_NO_POSIX_BACKTRACKING << 1)

/* This global variable defines the particular regexp syntax to use (for
   some interfaces).  When a regexp is compiled, the syntax used is
   stored in the pattern buffer, so changing this does not affect
   already-compiled regexps.  */
extern reg_syntax_t re_syntax_options;

/* Define combinations of the above bits for the standard possibilities.
   (The [[[ comments delimit what gets put into the Texinfo file, so
   don't delete them!)  */
/* [[[begin syntaxes]]] */
#define RE_SYNTAX_EMACS (RE_INTERVALS | RE_CHAR_CLASSES)

/* [[[end syntaxes]]] */

/* Maximum number of duplicates an interval can allow.  Some systems
   (erroneously) define this in other header files, but we want our
   value, so remove any previous define.  */
#ifdef RE_DUP_MAX
#undef RE_DUP_MAX
#endif
/* Repeat counts are stored in opcodes as 2 byte integers.  This was
   previously limited to 7fff because the parsing code uses signed
   ints.  But Emacs only runs on 32 bit platforms anyway.  */
#define RE_DUP_MAX (0xffff)


/* POSIX `cflags' bits (i.e., information for `regcomp').  */

/* If this bit is set, then use extended regular expression syntax.
   If not set, then use basic regular expression syntax.  */
#define REG_EXTENDED 1

/* If this bit is set, then ignore case when matching.
   If not set, then case is significant.  */
#define REG_ICASE (REG_EXTENDED << 1)

/* If this bit is set, then anchors do not match at newline
     characters in the string.
   If not set, then anchors do match at newlines.  */
#define REG_NEWLINE (REG_ICASE << 1)

/* If this bit is set, then report only success or fail in regexec.
   If not set, then returns differ between not matching and errors.  */
#define REG_NOSUB (REG_NEWLINE << 1)


/* POSIX `eflags' bits (i.e., information for regexec).  */

/* If this bit is set, then the beginning-of-line operator doesn't match
     the beginning of the string (presumably because it's not the
     beginning of a line).
   If not set, then the beginning-of-line operator does match the
     beginning of the string.  */
#define REG_NOTBOL 1

/* Like REG_NOTBOL, except for the end-of-line.  */
#define REG_NOTEOL (1 << 1)


/* If any error codes are removed, changed, or added, update the
   `re_error_msg' table in regex.c.  */
typedef enum
{
  REG_NOERROR = 0,	/* Success.  */
  REG_NOMATCH,		/* Didn't find a match (for regexec).  */

  /* POSIX regcomp return error codes.  (In the order listed in the
     standard.)  */
  REG_BADPAT,		/* Invalid pattern.  */
  REG_ECOLLATE,		/* Not implemented.  */
  REG_ECTYPE,		/* Invalid character class name.  */
  REG_EESCAPE,		/* Trailing backslash.  */
  REG_ESUBREG,		/* Invalid back reference.  */
  REG_EBRACK,		/* Unmatched left bracket.  */
  REG_EPAREN,		/* Parenthesis imbalance.  */
  REG_EBRACE,		/* Unmatched \{.  */
  REG_BADBR,		/* Invalid contents of \{\}.  */
  REG_ERANGE,		/* Invalid range end.  */
  REG_ESPACE,		/* Ran out of memory.  */
  REG_BADRPT,		/* No preceding re for repetition op.  */

  /* Error codes we've added.  */
  REG_EEND,		/* Premature end.  */
  REG_ESIZE,		/* Compiled pattern bigger than 2^16 bytes.  */
  REG_ERPAREN,		/* Unmatched ) or \); not returned from regcomp.  */
  REG_ESIZEBR           /* n or m too big in \{n,m\} */
#ifdef emacs
  ,REG_ESYNTAX,		/* Invalid syntax designator. */
  REG_ERANGESPAN,	/* Ranges may not span charsets. */
  REG_ECATEGORY         /* Invalid category designator */
#endif
} reg_errcode_t;


/* 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 RE_MAX_BUF_SIZE (1L << 16)

/* Internal register numbers are stored in opcodes as 2 byte
   integers. Previously they were just one byte, and this was limited to 255,
   which was unreasonably small (since in the past shy groups also needed
   internal register numbers).

   Each register in the pattern needs at least a start_memory (three bytes in
   the buffer) and a stop_memory (three bytes in the buffer), so RE_MAX_BUF_SIZE
   / 6 is a reasonable limit. */
#define MAX_REGNUM ((RE_MAX_BUF_SIZE) / 6)

typedef int regnum_t;


/* This data structure represents a compiled pattern.  Before calling
   the pattern compiler, the fields `buffer', `allocated', `fastmap',
   `translate', and `no_sub' can be set.  After the pattern has been
   compiled, the `re_nsub' field is available.  All other fields are
   private to the regex routines.  */

struct re_pattern_buffer
{
/* [[[begin pattern_buffer]]] */
	/* Space that holds the compiled pattern.  It is declared as
          `unsigned char *' because its elements are
           sometimes used as array indexes.  */
  unsigned char *buffer;

	/* Number of bytes to which `buffer' points.  */
  Bytecount allocated;

	/* Number of bytes actually used in `buffer'.  */
  Bytecount used;

        /* Syntax setting with which the pattern was compiled.  */
  reg_syntax_t syntax;

        /* Pointer to a fastmap, if any, otherwise zero.  re_search uses
           the fastmap, if there is one, to skip over impossible
           starting points for matches.  */
  char *fastmap;

        /* Either a translate table to apply to all characters before
           comparing them, or zero for no translation.  The translation
           is applied to a pattern when it is compiled and to a string
           when it is matched.  */
  RE_TRANSLATE_TYPE translate;

        /* Inclusive upper bound on the subpattern numbers (the returnable
           groups) found by the compiler. This ignores shy groups. The range 0
           to re_nsub may have one or more discontinuities if one or more
           named non-shy groups were used. */
  regnum_t re_nsub;

        /* Inclusive upper bound on the number of groups found by the compiler,
           not including shy ones. The range 0 to re_ngroups should have no
           discontinuities. */
  regnum_t re_ngroups;

        /* Zero if this pattern cannot match the empty string, one else.
           Well, in truth it's used only in `re_search_2', to see
           whether or not we should use the fastmap, so we don't set
           this absolutely perfectly; see `re_compile_fastmap' (the
           `duplicate' case).  */
  unsigned int can_be_null : 1;

        /* If REGS_UNALLOCATED, allocate space in the `regs' structure
             for `max (RE_NREGS, re_nsub + 1)' groups.
           If REGS_REALLOCATE, reallocate space if necessary.
           If REGS_FIXED, use what's there.  */
#define REGS_UNALLOCATED 0
#define REGS_REALLOCATE 1
#define REGS_FIXED 2
  unsigned int regs_allocated : 2;

        /* Set to zero when `regex_compile' compiles a pattern; set to one
           by `re_compile_fastmap' if it updates the fastmap.  */
  unsigned int fastmap_accurate : 1;

        /* If set, `re_match_2' does not return information about
           subexpressions.  */
  unsigned int no_sub : 1;

        /* If set, a beginning-of-line anchor doesn't match at the
           beginning of the string.  */
  unsigned int not_bol : 1;

        /* Similarly for an end-of-line anchor.  */
  unsigned int not_eol : 1;

        /* If true, an anchor at a newline matches.  */
  unsigned int newline_anchor : 1;

  unsigned int warned_about_incompatible_back_references : 1;

	/* Mapping between back references and groups (may not be
	   equivalent with shy groups). */
  regnum_t *external_to_internal_register;

  Elemcount external_to_internal_register_size;

/* [[[end pattern_buffer]]] */
};

typedef struct re_pattern_buffer regex_t;

/* Type for byte offsets within the string.  POSIX mandates this.  */
typedef Bytecount regoff_t;


/* This is the structure we store register match data in.  See
   regex.texinfo for a full description of what registers match.  */
struct re_registers
{
  regnum_t num_regs;		/* number of registers allocated */
  regoff_t *start;
  regoff_t *end;
};


/* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
   `re_match_2' returns information about at least this many registers
   the first time a `regs' structure is passed.  */
#ifndef RE_NREGS
#define RE_NREGS 30
#endif


/* POSIX specification for registers.  Aside from the different names than
   `re_registers', POSIX uses an array of structures, instead of a
   structure of arrays.  */
typedef struct
{
  regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
  regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
} regmatch_t;

/* Declarations for routines.  */

/* Sets the current default syntax to SYNTAX, and return the old syntax.
   You can also simply assign to the `re_syntax_options' variable.  */
reg_syntax_t re_set_syntax (reg_syntax_t syntax);

/* Compile the regular expression PATTERN, with length LENGTH
   and syntax given by the global `re_syntax_options', into the buffer
   BUFFER.  Return NULL if successful, and an error string if not.  */
const char *re_compile_pattern (const char *pattern, int length,
				struct re_pattern_buffer *buffer);


/* Compile a fastmap for the compiled pattern in BUFFER; used to
   accelerate searches.  Return 0 if successful and -2 if was an
   internal error.  */
int re_compile_fastmap (struct re_pattern_buffer *buffer
			RE_LISP_SHORT_CONTEXT_ARGS_DECL);


/* Search in the string STRING (with length LENGTH) for the pattern
   compiled into BUFFER.  Start searching at position START, for RANGE
   characters.  Return the starting position of the match, -1 for no
   match, or -2 for an internal error.  Also return register
   information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
int re_search (struct re_pattern_buffer *buffer, const char *string,
	       int length, int start, int range,
	       struct re_registers *regs RE_LISP_CONTEXT_ARGS_DECL);


/* Like `re_search', but search in the concatenation of STRING1 and
   STRING2.  Also, stop searching at index START + STOP.  */
int re_search_2 (struct re_pattern_buffer *buffer, const char *string1,
		 int length1, const char *string2, int length2, int start,
		 int range, struct re_registers *regs, int stop
		 RE_LISP_CONTEXT_ARGS_DECL);

#ifndef emacs /* never used by XEmacs */

/* Like `re_search', but return how many characters in STRING the regexp
   in BUFFER matched, starting at position START.  */
int re_match (struct re_pattern_buffer *buffer, const char *string,
	      int length, int start, struct re_registers *regs
	      RE_LISP_CONTEXT_ARGS_DECL);

#endif /* not emacs */

/* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
int re_match_2 (struct re_pattern_buffer *buffer, const char *string1,
		int length1, const char *string2, int length2,
		int start, struct re_registers *regs, int stop
		RE_LISP_CONTEXT_ARGS_DECL);

/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
   ENDS.  Subsequent matches using BUFFER and REGS will use this memory
   for recording register information.  STARTS and ENDS must be
   allocated with malloc, 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 *buffer,
		       struct re_registers *regs, regnum_t num_regs,
		       regoff_t *starts, regoff_t *ends);

enum regex_debug
  {
    RE_DEBUG_COMPILATION = 1 << 0,
    RE_DEBUG_FAILURE_POINT = 1 << 1,
    RE_DEBUG_MATCHING = 1 << 2,
  };

extern int debug_regexps;

typedef enum
  {
    RECC_ERROR = 0,
    RECC_ALNUM, RECC_ALPHA, RECC_WORD,
    RECC_GRAPH, RECC_PRINT,
    RECC_LOWER, RECC_UPPER,
    RECC_PUNCT, RECC_CNTRL,
    RECC_DIGIT, RECC_XDIGIT,
    RECC_BLANK, RECC_SPACE,
    RECC_MULTIBYTE, RECC_NONASCII,
    RECC_ASCII, RECC_UNIBYTE
} re_wctype_t;

/* Map a string to the char class it names (if any).  */
re_wctype_t re_wctype (const unsigned char *, Bytecount length);

/* Is character CH a member of the character class CC? */
int re_iswctype (int ch, re_wctype_t cc RE_ISWCTYPE_ARG_DECL);

/* Bits used to implement the multibyte-part of the various character
   classes such as [:alnum:] in a charset's range table. XEmacs; use an
   enum, so they're visible in the debugger. */
enum
{
  BIT_WORD = (1 << 0),
  BIT_LOWER = (1 << 1),
  BIT_PUNCT = (1 << 2),
  BIT_SPACE = (1 << 3),
  BIT_UPPER = (1 << 4),
  /* XEmacs; we need this, because we unify treatment of ASCII and non-ASCII
     (possible matches) in charset_mule. [:alpha:] matches all characters
     with word syntax, with the exception of [0-9]. We don't need
     BIT_MULTIBYTE. */
  BIT_ALPHA = (1 << 5)
};

#ifdef emacs
reg_errcode_t compile_char_class (re_wctype_t cc, Lisp_Object rtab,
                                  Bitbyte *flags_out);

#endif

/* isalpha etc. are used for the character classes.  */
#include <ctype.h>

#ifdef emacs

/* 1 if C is an ASCII character.  */
#define ISASCII(c) ((c) < 0x80)

/* 1 if C is a unibyte character.  */
#define ISUNIBYTE ISASCII

/* The Emacs definitions should not be directly affected by locales.  */

/* In Emacs, these are only used for single-byte characters.  */
#define ISDIGIT(c) ((c) >= '0' && (c) <= '9')
#define ISCNTRL(c) ((c) < ' ')
#define ISXDIGIT(c) (ISDIGIT (c) || ((c) >= 'a' && (c) <= 'f')	\
		     || ((c) >= 'A' && (c) <= 'F'))

/* This is only used for single-byte characters.  */
#define ISBLANK(c) ((c) == ' ' || (c) == '\t')

/* The rest must handle multibyte characters.  */

#define ISGRAPH(c) ((c) > ' ' && (c) != 0x7f)
#define ISPRINT(c) ((c) == ' ' || ISGRAPH (c))
#define ISALPHA(c) (ISASCII (c) ? (((c) >= 'a' && (c) <= 'z')		\
				   || ((c) >= 'A' && (c) <= 'Z'))	\
		    : ISWORD (c))
#define ISALNUM(c) ISWORD (c)

#define ISLOWER(c) LOWERCASEP (lispbuf, c)

#define ISPUNCT(c) (ISASCII (c)                                 \
		    ? ((c) > ' ' && (c) < 0x7F			\
		       && !(((c) >= 'a' && (c) <= 'z')		\
		            || ((c) >= 'A' && (c) <= 'Z')	\
		            || ((c) >= '0' && (c) <= '9')))	\
		    : !ISWORD (c))

#define ISSPACE(c) \
	(SYNTAX (BUFFER_MIRROR_SYNTAX_TABLE (lispbuf), c) == Swhitespace)

#define ISUPPER(c) UPPERCASEP (lispbuf, c)

#define ISWORD(c) (SYNTAX (BUFFER_MIRROR_SYNTAX_TABLE (lispbuf), c) == Sword)

#endif 

END_C_DECLS

#endif /* INCLUDED_regex_h_ */
