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Diffstat (limited to 'src/grep/lib/dfa.h')
| -rw-r--r-- | src/grep/lib/dfa.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/src/grep/lib/dfa.h b/src/grep/lib/dfa.h new file mode 100644 index 0000000..edc39dc --- /dev/null +++ b/src/grep/lib/dfa.h @@ -0,0 +1,154 @@ +/* dfa.h - declarations for GNU deterministic regexp compiler + Copyright (C) 1988, 1998, 2007, 2009-2021 Free Software Foundation, Inc. + + 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 3, 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; if not, write to the Free Software + Foundation, Inc., + 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA */ + +/* Written June, 1988 by Mike Haertel */ + +#ifndef DFA_H_ +#define DFA_H_ + +#include <regex.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdlib.h> + +#ifdef __cplusplus +extern "C" { +#endif + +struct localeinfo; /* See localeinfo.h. */ + +/* Element of a list of strings, at least one of which is known to + appear in any R.E. matching the DFA. */ +struct dfamust +{ + bool exact; + bool begline; + bool endline; + char must[FLEXIBLE_ARRAY_MEMBER]; +}; + +/* The dfa structure. It is completely opaque. */ +struct dfa; + +/* Needed when Gnulib is not used. */ +#ifndef _GL_ATTRIBUTE_MALLOC +# define _GL_ATTRIBUTE_MALLOC +# define _GL_ATTRIBUTE_DEALLOC_FREE +# define _GL_ATTRIBUTE_RETURNS_NONNULL +#endif + +/* Entry points. */ + +/* Allocate a struct dfa. The struct dfa is completely opaque. + It should be initialized via dfasyntax or dfacopysyntax before other use. + The returned pointer should be passed directly to free() after + calling dfafree() on it. */ +extern struct dfa *dfaalloc (void) + _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE + _GL_ATTRIBUTE_RETURNS_NONNULL; + +/* DFA options that can be ORed together, for dfasyntax's 4th arg. */ +enum + { + /* ^ and $ match only the start and end of data, and do not match + end-of-line within data. This is always false for grep, but + possibly true for other apps. */ + DFA_ANCHOR = 1 << 0, + + /* '\0' in data is end-of-line, instead of the traditional '\n'. */ + DFA_EOL_NUL = 1 << 1 + }; + +/* Initialize or reinitialize a DFA. The arguments are: + 1. The DFA to operate on. + 2. Information about the current locale. + 3. Syntax bits described in regex.h. + 4. Additional DFA options described above. */ +extern void dfasyntax (struct dfa *, struct localeinfo const *, + reg_syntax_t, int); + +/* Initialize or reinitialize a DFA from an already-initialized DFA. */ +extern void dfacopysyntax (struct dfa *, struct dfa const *); + +/* Parse the given string of given length into the given struct dfa. */ +extern void dfaparse (char const *, ptrdiff_t, struct dfa *); + +struct dfamust; + +/* Free the storage held by the components of a struct dfamust. */ +extern void dfamustfree (struct dfamust *); + +/* Allocate and return a struct dfamust from a struct dfa that was + initialized by dfaparse and not yet given to dfacomp. */ +extern struct dfamust *dfamust (struct dfa const *) + _GL_ATTRIBUTE_DEALLOC (dfamustfree, 1); + +/* Compile the given string of the given length into the given struct dfa. + The last argument says whether to build a searching or an exact matcher. + A null first argument means the struct dfa has already been + initialized by dfaparse; the second argument is ignored. */ +extern void dfacomp (char const *, ptrdiff_t, struct dfa *, bool); + +/* Search through a buffer looking for a match to the given struct dfa. + Find the first occurrence of a string matching the regexp in the + buffer, and the shortest possible version thereof. Return a pointer to + the first character after the match, or NULL if none is found. BEGIN + points to the beginning of the buffer, and END points to the first byte + after its end. Note however that we store a sentinel byte (usually + newline) in *END, so the actual buffer must be one byte longer. + When ALLOW_NL is true, newlines may appear in the matching string. + If COUNT is non-NULL, increment *COUNT once for each newline processed. + Finally, if BACKREF is non-NULL set *BACKREF to indicate whether we + encountered a back-reference. The caller can use this to decide + whether to fall back on a backtracking matcher. */ +extern char *dfaexec (struct dfa *d, char const *begin, char *end, + bool allow_nl, ptrdiff_t *count, bool *backref); + +/* Return a superset for D. The superset matches everything that D + matches, along with some other strings (though the latter should be + rare, for efficiency reasons). Return a null pointer if no useful + superset is available. */ +extern struct dfa *dfasuperset (struct dfa const *d) _GL_ATTRIBUTE_PURE; + +/* The DFA is likely to be fast. */ +extern bool dfaisfast (struct dfa const *) _GL_ATTRIBUTE_PURE; + +/* Return true if every construct in D is supported by this DFA matcher. */ +extern bool dfasupported (struct dfa const *) _GL_ATTRIBUTE_PURE; + +/* Free the storage held by the components of a struct dfa. */ +extern void dfafree (struct dfa *); + +/* Error handling. */ + +/* dfawarn() is called by the regexp routines whenever a regex is compiled + that likely doesn't do what the user wanted. It takes a single + argument, a NUL-terminated string describing the situation. The user + must supply a dfawarn. */ +extern void dfawarn (const char *); + +/* dfaerror() is called by the regexp routines whenever an error occurs. It + takes a single argument, a NUL-terminated string describing the error. + The user must supply a dfaerror. */ +extern _Noreturn void dfaerror (const char *); + +#ifdef __cplusplus +} +#endif + +#endif /* dfa.h */ |