maint/gnulib/lib/dfa.h

/* */
This source file includes following definitions.
dfaalloc
   1 /* dfa.h - declarations for GNU deterministic regexp compiler
   2    Copyright (C) 1988, 1998, 2007, 2009-2021 Free Software Foundation, Inc.
   3 
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3, or (at your option)
   7    any later version.
   8 
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13 
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc.,
  17    51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA */
  18 
  19 /* Written June, 1988 by Mike Haertel */
  20 
  21 #ifndef DFA_H_
  22 #define DFA_H_
  23 
  24 #include "idx.h"
  25 #include <regex.h>
  26 #include <stdbool.h>
  27 #include <stddef.h>
  28 #include <stdlib.h>
  29 
  30 #ifdef __cplusplus
  31 extern "C" {
  32 #endif
  33 
  34 struct localeinfo; /* See localeinfo.h.  */
  35 
  36 /* Element of a list of strings, at least one of which is known to
  37    appear in any R.E. matching the DFA. */
  38 struct dfamust
  39 {
  40   bool exact;
  41   bool begline;
  42   bool endline;
  43   char must[FLEXIBLE_ARRAY_MEMBER];
  44 };
  45 
  46 /* The dfa structure. It is completely opaque. */
  47 struct dfa;
  48 
  49 /* Needed when Gnulib is not used.  */
  50 #ifndef _GL_ATTRIBUTE_MALLOC
  51 # define _GL_ATTRIBUTE_MALLOC
  52 # define _GL_ATTRIBUTE_DEALLOC(f, i)
  53 # define _GL_ATTRIBUTE_DEALLOC_FREE
  54 # define _GL_ATTRIBUTE_RETURNS_NONNULL
  55 #endif
  56 
  57 /* Entry points. */
  58 
  59 /* Allocate a struct dfa.  The struct dfa is completely opaque.
  60    It should be initialized via dfasyntax or dfacopysyntax before other use.
  61    The returned pointer should be passed directly to free() after
  62    calling dfafree() on it. */
  63 extern struct dfa *dfaalloc (void)
     /*  */
  64   _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE
  65   _GL_ATTRIBUTE_RETURNS_NONNULL;
  66 
  67 /* DFA options that can be ORed together, for dfasyntax's 4th arg.  */
  68 enum
  69   {
  70     /* ^ and $ match only the start and end of data, and do not match
  71        end-of-line within data.  This is always false for grep, but
  72        possibly true for other apps.  */
  73     DFA_ANCHOR = 1 << 0,
  74 
  75     /* '\0' in data is end-of-line, instead of the traditional '\n'.  */
  76     DFA_EOL_NUL = 1 << 1
  77   };
  78 
  79 /* Initialize or reinitialize a DFA.  The arguments are:
  80    1. The DFA to operate on.
  81    2. Information about the current locale.
  82    3. Syntax bits described in regex.h.
  83    4. Additional DFA options described above.  */
  84 extern void dfasyntax (struct dfa *, struct localeinfo const *,
  85                        reg_syntax_t, int);
  86 
  87 /* Initialize or reinitialize a DFA from an already-initialized DFA.  */
  88 extern void dfacopysyntax (struct dfa *, struct dfa const *);
  89 
  90 /* Parse the given string of given length into the given struct dfa.  */
  91 extern void dfaparse (char const *, idx_t, struct dfa *);
  92 
  93 struct dfamust;
  94 
  95 /* Free the storage held by the components of a struct dfamust. */
  96 extern void dfamustfree (struct dfamust *);
  97 
  98 /* Allocate and return a struct dfamust from a struct dfa that was
  99    initialized by dfaparse and not yet given to dfacomp.  */
 100 extern struct dfamust *dfamust (struct dfa const *)
 101   _GL_ATTRIBUTE_DEALLOC (dfamustfree, 1);
 102 
 103 /* Compile the given string of the given length into the given struct dfa.
 104    The last argument says whether to build a searching or an exact matcher.
 105    A null first argument means the struct dfa has already been
 106    initialized by dfaparse; the second argument is ignored.  */
 107 extern void dfacomp (char const *, idx_t, struct dfa *, bool);
 108 
 109 /* Search through a buffer looking for a match to the given struct dfa.
 110    Find the first occurrence of a string matching the regexp in the
 111    buffer, and the shortest possible version thereof.  Return a pointer to
 112    the first character after the match, or NULL if none is found.  BEGIN
 113    points to the beginning of the buffer, and END points to the first byte
 114    after its end.  Note however that we store a sentinel byte (usually
 115    newline) in *END, so the actual buffer must be one byte longer.
 116    When ALLOW_NL is true, newlines may appear in the matching string.
 117    If COUNT is non-NULL, increment *COUNT once for each newline processed.
 118    Finally, if BACKREF is non-NULL set *BACKREF to indicate whether we
 119    encountered a back-reference.  The caller can use this to decide
 120    whether to fall back on a backtracking matcher.  */
 121 extern char *dfaexec (struct dfa *d, char const *begin, char *end,
 122                       bool allow_nl, idx_t *count, bool *backref);
 123 
 124 /* Return a superset for D.  The superset matches everything that D
 125    matches, along with some other strings (though the latter should be
 126    rare, for efficiency reasons).  Return a null pointer if no useful
 127    superset is available.  */
 128 extern struct dfa *dfasuperset (struct dfa const *d) _GL_ATTRIBUTE_PURE;
 129 
 130 /* The DFA is likely to be fast.  */
 131 extern bool dfaisfast (struct dfa const *) _GL_ATTRIBUTE_PURE;
 132 
 133 /* Return true if every construct in D is supported by this DFA matcher.  */
 134 extern bool dfasupported (struct dfa const *) _GL_ATTRIBUTE_PURE;
 135 
 136 /* Free the storage held by the components of a struct dfa. */
 137 extern void dfafree (struct dfa *);
 138 
 139 /* Error handling. */
 140 
 141 /* dfawarn() is called by the regexp routines whenever a regex is compiled
 142    that likely doesn't do what the user wanted.  It takes a single
 143    argument, a NUL-terminated string describing the situation.  The user
 144    must supply a dfawarn.  */
 145 extern void dfawarn (const char *);
 146 
 147 /* dfaerror() is called by the regexp routines whenever an error occurs.  It
 148    takes a single argument, a NUL-terminated string describing the error.
 149    The user must supply a dfaerror.  */
 150 extern _Noreturn void dfaerror (const char *);
 151 
 152 #ifdef __cplusplus
 153 }
 154 #endif
 155 
 156 #endif /* dfa.h */
/* */
root/maint/gnulib/lib/dfa.h

INCLUDED FROM

DEFINITIONS
