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/* dfa.h - declarations for GNU deterministic regexp compiler
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Copyright (C) 1988, 1998, 2007, 2009-2024 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3, or (at your option)
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA */
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/* Written June, 1988 by Mike Haertel */
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/* This file uses _Noreturn, _GL_ATTRIBUTE_DEALLOC, _GL_ATTRIBUTE_MALLOC,
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_GL_ATTRIBUTE_PURE, _GL_ATTRIBUTE_RETURNS_NONNULL. */
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#if !_GL_CONFIG_H_INCLUDED
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#error "Please include config.h first."
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struct localeinfo; /* See localeinfo.h. */
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/* Element of a list of strings, at least one of which is known to
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appear in any R.E. matching the DFA. */
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char must[FLEXIBLE_ARRAY_MEMBER];
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/* The dfa structure. It is completely opaque. */
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/* Needed when Gnulib is not used. */
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#ifndef _GL_ATTRIBUTE_MALLOC
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# define _GL_ATTRIBUTE_MALLOC
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# define _GL_ATTRIBUTE_DEALLOC(f, i)
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# define _GL_ATTRIBUTE_DEALLOC_FREE
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# define _GL_ATTRIBUTE_RETURNS_NONNULL
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/* Allocate a struct dfa. The struct dfa is completely opaque.
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It should be initialized via dfasyntax or dfacopysyntax before other use.
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The returned pointer should be passed directly to free() after
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calling dfafree() on it. */
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extern struct dfa *dfaalloc (void)
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_GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE
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_GL_ATTRIBUTE_RETURNS_NONNULL;
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/* DFA options that can be ORed together, for dfasyntax's 4th arg. */
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/* ^ and $ match only the start and end of data, and do not match
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end-of-line within data. This is always false for grep, but
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possibly true for other apps. */
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/* '\0' in data is end-of-line, instead of the traditional '\n'. */
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/* Treat [:alpha:] etc. as an error at the top level, instead of
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DFA_CONFUSING_BRACKETS_ERROR = 1 << 2,
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/* Warn about stray backslashes before ordinary characters other
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than ] and } which are special because even though POSIX
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says \] and \} have undefined interpretation, platforms
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reliably ignore those stray backlashes and warning about them
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would likely cause more trouble than it's worth. */
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DFA_STRAY_BACKSLASH_WARN = 1 << 3,
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/* Warn about * appearing out of context at the start of an
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expression or subexpression. */
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DFA_STAR_WARN = 1 << 4,
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/* Warn about +, ?, {...} appearing out of context at the start of
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an expression or subexpression. */
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DFA_PLUS_WARN = 1 << 5,
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/* Initialize or reinitialize a DFA. The arguments are:
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1. The DFA to operate on.
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2. Information about the current locale.
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3. Syntax bits described in regex.h.
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4. Additional DFA options described above. */
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extern void dfasyntax (struct dfa *, struct localeinfo const *,
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/* Initialize or reinitialize a DFA from an already-initialized DFA. */
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extern void dfacopysyntax (struct dfa *, struct dfa const *);
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/* Parse the given string of given length into the given struct dfa. */
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extern void dfaparse (char const *, idx_t, struct dfa *);
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/* Free the storage held by the components of a struct dfamust. */
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extern void dfamustfree (struct dfamust *);
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/* Allocate and return a struct dfamust from a struct dfa that was
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initialized by dfaparse and not yet given to dfacomp. */
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extern struct dfamust *dfamust (struct dfa const *)
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_GL_ATTRIBUTE_DEALLOC (dfamustfree, 1);
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/* Compile the given string of the given length into the given struct dfa.
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The last argument says whether to build a searching or an exact matcher.
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A null first argument means the struct dfa has already been
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initialized by dfaparse; the second argument is ignored. */
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extern void dfacomp (char const *, idx_t, struct dfa *, bool);
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/* Search through a buffer looking for a match to the given struct dfa.
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Find the first occurrence of a string matching the regexp in the
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buffer, and the shortest possible version thereof. Return a pointer to
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the first character after the match, or NULL if none is found. BEGIN
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points to the beginning of the buffer, and END points to the first byte
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after its end. Note however that we store a sentinel byte (usually
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newline) in *END, so the actual buffer must be one byte longer.
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When ALLOW_NL is true, newlines may appear in the matching string.
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If COUNT is non-NULL, increment *COUNT once for each newline processed.
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Finally, if BACKREF is non-NULL set *BACKREF to indicate whether we
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encountered a back-reference. The caller can use this to decide
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whether to fall back on a backtracking matcher. */
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extern char *dfaexec (struct dfa *d, char const *begin, char *end,
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bool allow_nl, idx_t *count, bool *backref);
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/* Return a superset for D. The superset matches everything that D
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matches, along with some other strings (though the latter should be
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rare, for efficiency reasons). Return a null pointer if no useful
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superset is available. */
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extern struct dfa *dfasuperset (struct dfa const *d) _GL_ATTRIBUTE_PURE;
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/* The DFA is likely to be fast. */
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extern bool dfaisfast (struct dfa const *) _GL_ATTRIBUTE_PURE;
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/* Return true if every construct in D is supported by this DFA matcher. */
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extern bool dfasupported (struct dfa const *) _GL_ATTRIBUTE_PURE;
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/* Free the storage held by the components of a struct dfa. */
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extern void dfafree (struct dfa *);
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/* Error handling. */
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/* dfawarn() is called by the regexp routines whenever a regex is compiled
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that likely doesn't do what the user wanted. It takes a single
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argument, a NUL-terminated string describing the situation. The user
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must supply a dfawarn. */
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extern void dfawarn (const char *);
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/* dfaerror() is called by the regexp routines whenever an error occurs. It
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takes a single argument, a NUL-terminated string describing the error.
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The user must supply a dfaerror. */
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extern _Noreturn void dfaerror (const char *);
added
removed
support/dfa.h
