/* Extended regular expression matching and search library. Copyright (C) 2002-2007,2009,2010 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Isamu Hasegawa . The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ #if defined __TANDEM /* This is currently duplicated from git-compat-utils.h */ # ifdef NO_INTPTR_T typedef long intptr_t; typedef unsigned long uintptr_t; # endif #endif static reg_errcode_t re_compile_internal (regex_t *preg, const char * pattern, size_t length, reg_syntax_t syntax); static void re_compile_fastmap_iter (regex_t *bufp, const re_dfastate_t *init_state, char *fastmap); static reg_errcode_t init_dfa (re_dfa_t *dfa, size_t pat_len); #ifdef RE_ENABLE_I18N static void free_charset (re_charset_t *cset); #endif /* RE_ENABLE_I18N */ static void free_workarea_compile (regex_t *preg); static reg_errcode_t create_initial_state (re_dfa_t *dfa); #ifdef RE_ENABLE_I18N static void optimize_utf8 (re_dfa_t *dfa); #endif static reg_errcode_t analyze (regex_t *preg); static reg_errcode_t preorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)), void *extra); static reg_errcode_t postorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)), void *extra); static reg_errcode_t optimize_subexps (void *extra, bin_tree_t *node); static reg_errcode_t lower_subexps (void *extra, bin_tree_t *node); static bin_tree_t *lower_subexp (reg_errcode_t *err, regex_t *preg, bin_tree_t *node); static reg_errcode_t calc_first (void *extra, bin_tree_t *node); static reg_errcode_t calc_next (void *extra, bin_tree_t *node); static reg_errcode_t link_nfa_nodes (void *extra, bin_tree_t *node); static int duplicate_node (re_dfa_t *dfa, int org_idx, unsigned int constraint); static int search_duplicated_node (const re_dfa_t *dfa, int org_node, unsigned int constraint); static reg_errcode_t calc_eclosure (re_dfa_t *dfa); static reg_errcode_t calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, int node, int root); static reg_errcode_t calc_inveclosure (re_dfa_t *dfa); static int fetch_number (re_string_t *input, re_token_t *token, reg_syntax_t syntax); static int peek_token (re_token_t *token, re_string_t *input, reg_syntax_t syntax) internal_function; static bin_tree_t *parse (re_string_t *regexp, regex_t *preg, reg_syntax_t syntax, reg_errcode_t *err); static bin_tree_t *parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token, reg_syntax_t syntax, int nest, reg_errcode_t *err); static bin_tree_t *parse_branch (re_string_t *regexp, regex_t *preg, re_token_t *token, reg_syntax_t syntax, int nest, reg_errcode_t *err); static bin_tree_t *parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token, reg_syntax_t syntax, int nest, reg_errcode_t *err); static bin_tree_t *parse_sub_exp (re_string_t *regexp, regex_t *preg, re_token_t *token, reg_syntax_t syntax, int nest, reg_errcode_t *err); static bin_tree_t *parse_dup_op (bin_tree_t *dup_elem, re_string_t *regexp, re_dfa_t *dfa, re_token_t *token, reg_syntax_t syntax, reg_errcode_t *err); static bin_tree_t *parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token, reg_syntax_t syntax, reg_errcode_t *err); static reg_errcode_t parse_bracket_element (bracket_elem_t *elem, re_string_t *regexp, re_token_t *token, int token_len, re_dfa_t *dfa, reg_syntax_t syntax, int accept_hyphen); static reg_errcode_t parse_bracket_symbol (bracket_elem_t *elem, re_string_t *regexp, re_token_t *token); #ifdef RE_ENABLE_I18N static reg_errcode_t build_equiv_class (bitset_t sbcset, re_charset_t *mbcset, int *equiv_class_alloc, const unsigned char *name); static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset, re_charset_t *mbcset, int *char_class_alloc, const char *class_name, reg_syntax_t syntax); #else /* not RE_ENABLE_I18N */ static reg_errcode_t build_equiv_class (bitset_t sbcset, const unsigned char *name); static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset, const char *class_name, reg_syntax_t syntax); #endif /* not RE_ENABLE_I18N */ static bin_tree_t *build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans, const char *class_name, const char *extra, int non_match, reg_errcode_t *err); static bin_tree_t *create_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right, re_token_type_t type); static bin_tree_t *create_token_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right, const re_token_t *token); static bin_tree_t *duplicate_tree (const bin_tree_t *src, re_dfa_t *dfa); static void free_token (re_token_t *node); static reg_errcode_t free_tree (void *extra, bin_tree_t *node); static reg_errcode_t mark_opt_subexp (void *extra, bin_tree_t *node); /* 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? */ const char __re_error_msgid[] attribute_hidden = { #define REG_NOERROR_IDX 0 gettext_noop ("Success") /* REG_NOERROR */ "\0" #define REG_NOMATCH_IDX (REG_NOERROR_IDX + sizeof "Success") gettext_noop ("No match") /* REG_NOMATCH */ "\0" #define REG_BADPAT_IDX (REG_NOMATCH_IDX + sizeof "No match") gettext_noop ("Invalid regular expression") /* REG_BADPAT */ "\0" #define REG_ECOLLATE_IDX (REG_BADPAT_IDX + sizeof "Invalid regular expression") gettext_noop ("Invalid collation character") /* REG_ECOLLATE */ "\0" #define REG_ECTYPE_IDX (REG_ECOLLATE_IDX + sizeof "Invalid collation character") gettext_noop ("Invalid character class name") /* REG_ECTYPE */ "\0" #define REG_EESCAPE_IDX (REG_ECTYPE_IDX + sizeof "Invalid character class name") gettext_noop ("Trailing backslash") /* REG_EESCAPE */ "\0" #define REG_ESUBREG_IDX (REG_EESCAPE_IDX + sizeof "Trailing backslash") gettext_noop ("Invalid back reference") /* REG_ESUBREG */ "\0" #define REG_EBRACK_IDX (REG_ESUBREG_IDX + sizeof "Invalid back reference") gettext_noop ("Unmatched [ or [^") /* REG_EBRACK */ "\0" #define REG_EPAREN_IDX (REG_EBRACK_IDX + sizeof "Unmatched [ or [^") gettext_noop ("Unmatched ( or \\(") /* REG_EPAREN */ "\0" #define REG_EBRACE_IDX (REG_EPAREN_IDX + sizeof "Unmatched ( or \\(") gettext_noop ("Unmatched \\{") /* REG_EBRACE */ "\0" #define REG_BADBR_IDX (REG_EBRACE_IDX + sizeof "Unmatched \\{") gettext_noop ("Invalid content of \\{\\}") /* REG_BADBR */ "\0" #define REG_ERANGE_IDX (REG_BADBR_IDX + sizeof "Invalid content of \\{\\}") gettext_noop ("Invalid range end") /* REG_ERANGE */ "\0" #define REG_ESPACE_IDX (REG_ERANGE_IDX + sizeof "Invalid range end") gettext_noop ("Memory exhausted") /* REG_ESPACE */ "\0" #define REG_BADRPT_IDX (REG_ESPACE_IDX + sizeof "Memory exhausted") gettext_noop ("Invalid preceding regular expression") /* REG_BADRPT */ "\0" #define REG_EEND_IDX (REG_BADRPT_IDX + sizeof "Invalid preceding regular expression") gettext_noop ("Premature end of regular expression") /* REG_EEND */ "\0" #define REG_ESIZE_IDX (REG_EEND_IDX + sizeof "Premature end of regular expression") gettext_noop ("Regular expression too big") /* REG_ESIZE */ "\0" #define REG_ERPAREN_IDX (REG_ESIZE_IDX + sizeof "Regular expression too big") gettext_noop ("Unmatched ) or \\)") /* REG_ERPAREN */ }; const size_t __re_error_msgid_idx[] attribute_hidden = { REG_NOERROR_IDX, REG_NOMATCH_IDX, REG_BADPAT_IDX, REG_ECOLLATE_IDX, REG_ECTYPE_IDX, REG_EESCAPE_IDX, REG_ESUBREG_IDX, REG_EBRACK_IDX, REG_EPAREN_IDX, REG_EBRACE_IDX, REG_BADBR_IDX, REG_ERANGE_IDX, REG_ESPACE_IDX, REG_BADRPT_IDX, REG_EEND_IDX, REG_ESIZE_IDX, REG_ERPAREN_IDX }; /* Entry points for GNU code. */ #ifdef ZOS_USS /* For ZOS USS we must define btowc */ wchar_t btowc (int c) { wchar_t wtmp[2]; char tmp[2]; tmp[0] = c; tmp[1] = 0; mbtowc (wtmp, tmp, 1); return wtmp[0]; } #endif /* re_compile_pattern is the GNU regular expression compiler: it compiles PATTERN (of length LENGTH) 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. */ const char * re_compile_pattern (const char *pattern, size_t length, struct re_pattern_buffer *bufp) { reg_errcode_t ret; /* 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, unless RE_NO_SUB is set. */ bufp->no_sub = !!(re_syntax_options & RE_NO_SUB); /* Match anchors at newline. */ bufp->newline_anchor = 1; ret = re_compile_internal (bufp, pattern, length, re_syntax_options); if (!ret) return NULL; return gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]); } #ifdef _LIBC weak_alias (__re_compile_pattern, re_compile_pattern) #endif /* 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; } #ifdef _LIBC weak_alias (__re_set_syntax, re_set_syntax) #endif int re_compile_fastmap (struct re_pattern_buffer *bufp) { re_dfa_t *dfa = (re_dfa_t *) bufp->buffer; char *fastmap = bufp->fastmap; memset (fastmap, '\0', sizeof (char) * SBC_MAX); re_compile_fastmap_iter (bufp, dfa->init_state, fastmap); if (dfa->init_state != dfa->init_state_word) re_compile_fastmap_iter (bufp, dfa->init_state_word, fastmap); if (dfa->init_state != dfa->init_state_nl) re_compile_fastmap_iter (bufp, dfa->init_state_nl, fastmap); if (dfa->init_state != dfa->init_state_begbuf) re_compile_fastmap_iter (bufp, dfa->init_state_begbuf, fastmap); bufp->fastmap_accurate = 1; return 0; } #ifdef _LIBC weak_alias (__re_compile_fastmap, re_compile_fastmap) #endif static inline void __attribute ((always_inline)) re_set_fastmap (char *fastmap, int icase, int ch) { fastmap[ch] = 1; if (icase) fastmap[tolower (ch)] = 1; } /* Helper function for re_compile_fastmap. Compile fastmap for the initial_state INIT_STATE. */ static void re_compile_fastmap_iter (regex_t *bufp, const re_dfastate_t *init_state, char *fastmap) { volatile re_dfa_t *dfa = (re_dfa_t *) bufp->buffer; int node_cnt; int icase = (dfa->mb_cur_max == 1 && (bufp->syntax & RE_ICASE)); for (node_cnt = 0; node_cnt < init_state->nodes.nelem; ++node_cnt) { int node = init_state->nodes.elems[node_cnt]; re_token_type_t type = dfa->nodes[node].type; if (type == CHARACTER) { re_set_fastmap (fastmap, icase, dfa->nodes[node].opr.c); #ifdef RE_ENABLE_I18N if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1) { unsigned char *buf = re_malloc (unsigned char, dfa->mb_cur_max), *p; wchar_t wc; mbstate_t state; p = buf; *p++ = dfa->nodes[node].opr.c; while (++node < dfa->nodes_len && dfa->nodes[node].type == CHARACTER && dfa->nodes[node].mb_partial) *p++ = dfa->nodes[node].opr.c; memset (&state, '\0', sizeof (state)); if (__mbrtowc (&wc, (const char *) buf, p - buf, &state) == p - buf && (__wcrtomb ((char *) buf, towlower (wc), &state) != (size_t) -1)) re_set_fastmap (fastmap, 0, buf[0]); re_free (buf); } #endif } else if (type == SIMPLE_BRACKET) { int i, ch; for (i = 0, ch = 0; i < BITSET_WORDS; ++i) { int j; bitset_word_t w = dfa->nodes[node].opr.sbcset[i]; for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch) if (w & ((bitset_word_t) 1 << j)) re_set_fastmap (fastmap, icase, ch); } } #ifdef RE_ENABLE_I18N else if (type == COMPLEX_BRACKET) { re_charset_t *cset = dfa->nodes[node].opr.mbcset; int i; # ifdef _LIBC /* See if we have to try all bytes which start multiple collation elements. e.g. In da_DK, we want to catch 'a' since "aa" is a valid collation element, and don't catch 'b' since 'b' is the only collation element which starts from 'b' (and it is caught by SIMPLE_BRACKET). */ if (_NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES) != 0 && (cset->ncoll_syms || cset->nranges)) { const int32_t *table = (const int32_t *) _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB); for (i = 0; i < SBC_MAX; ++i) if (table[i] < 0) re_set_fastmap (fastmap, icase, i); } # endif /* _LIBC */ /* See if we have to start the match at all multibyte characters, i.e. where we would not find an invalid sequence. This only applies to multibyte character sets; for single byte character sets, the SIMPLE_BRACKET again suffices. */ if (dfa->mb_cur_max > 1 && (cset->nchar_classes || cset->non_match || cset->nranges # ifdef _LIBC || cset->nequiv_classes # endif /* _LIBC */ )) { unsigned char c = 0; do { mbstate_t mbs; memset (&mbs, 0, sizeof (mbs)); if (__mbrtowc (NULL, (char *) &c, 1, &mbs) == (size_t) -2) re_set_fastmap (fastmap, false, (int) c); } while (++c != 0); } else { /* ... Else catch all bytes which can start the mbchars. */ for (i = 0; i < cset->nmbchars; ++i) { char buf[256]; mbstate_t state; memset (&state, '\0', sizeof (state)); if (__wcrtomb (buf, cset->mbchars[i], &state) != (size_t) -1) re_set_fastmap (fastmap, icase, *(unsigned char *) buf); if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1) { if (__wcrtomb (buf, towlower (cset->mbchars[i]), &state) != (size_t) -1) re_set_fastmap (fastmap, false, *(unsigned char *) buf); } } } } #endif /* RE_ENABLE_I18N */ else if (type == OP_PERIOD #ifdef RE_ENABLE_I18N || type == OP_UTF8_PERIOD #endif /* RE_ENABLE_I18N */ || type == END_OF_RE) { memset (fastmap, '\1', sizeof (char) * SBC_MAX); if (type == END_OF_RE) bufp->can_be_null = 1; return; } } } /* Entry point for POSIX code. */ /* 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' to an allocated space for the fastmap; `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 *__restrict preg, const char *__restrict pattern, int cflags) { reg_errcode_t ret; reg_syntax_t syntax = ((cflags & REG_EXTENDED) ? RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC); preg->buffer = NULL; preg->allocated = 0; preg->used = 0; /* Try to allocate space for the fastmap. */ preg->fastmap = re_malloc (char, SBC_MAX); if (BE (preg->fastmap == NULL, 0)) return REG_ESPACE; syntax |= (cflags & REG_ICASE) ? RE_ICASE : 0; /* 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); preg->translate = NULL; ret = re_compile_internal (preg, pattern, strlen (pattern), syntax); /* 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; /* We have already checked preg->fastmap != NULL. */ if (BE (ret == REG_NOERROR, 1)) /* Compute the fastmap now, since regexec cannot modify the pattern buffer. This function never fails in this implementation. */ (void) re_compile_fastmap (preg); else { /* Some error occurred while compiling the expression. */ re_free (preg->fastmap); preg->fastmap = NULL; } return (int) ret; } #ifdef _LIBC weak_alias (__regcomp, regcomp) #endif /* 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 *__restrict preg, char *__restrict errbuf, size_t errbuf_size) { const char *msg; size_t msg_size; if (BE (errcode < 0 || errcode >= (int) (sizeof (__re_error_msgid_idx) / sizeof (__re_error_msgid_idx[0])), 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 + __re_error_msgid_idx[errcode]); msg_size = strlen (msg) + 1; /* Includes the null. */ if (BE (errbuf_size != 0, 1)) { if (BE (msg_size > errbuf_size, 0)) { memcpy (errbuf, msg, errbuf_size - 1); errbuf[errbuf_size - 1] = 0; } else memcpy (errbuf, msg, msg_size); } return msg_size; } #ifdef _LIBC weak_alias (__regerror, regerror) #endif #ifdef RE_ENABLE_I18N /* This static array is used for the map to single-byte characters when UTF-8 is used. Otherwise we would allocate memory just to initialize it the same all the time. UTF-8 is the preferred encoding so this is a worthwhile optimization. */ #if __GNUC__ >= 3 static const bitset_t utf8_sb_map = { /* Set the first 128 bits. */ [0 ... 0x80 / BITSET_WORD_BITS - 1] = BITSET_WORD_MAX }; #else /* ! (__GNUC__ >= 3) */ static bitset_t utf8_sb_map; #endif /* __GNUC__ >= 3 */ #endif /* RE_ENABLE_I18N */ static void free_dfa_content (re_dfa_t *dfa) { int i, j; if (dfa->nodes) for (i = 0; i < dfa->nodes_len; ++i) free_token (dfa->nodes + i); re_free (dfa->nexts); for (i = 0; i < dfa->nodes_len; ++i) { if (dfa->eclosures != NULL) re_node_set_free (dfa->eclosures + i); if (dfa->inveclosures != NULL) re_node_set_free (dfa->inveclosures + i); if (dfa->edests != NULL) re_node_set_free (dfa->edests + i); } re_free (dfa->edests); re_free (dfa->eclosures); re_free (dfa->inveclosures); re_free (dfa->nodes); if (dfa->state_table) for (i = 0; i <= dfa->state_hash_mask; ++i) { struct re_state_table_entry *entry = dfa->state_table + i; for (j = 0; j < entry->num; ++j) { re_dfastate_t *state = entry->array[j]; free_state (state); } re_free (entry->array); } re_free (dfa->state_table); #ifdef RE_ENABLE_I18N if (dfa->sb_char != utf8_sb_map) re_free (dfa->sb_char); #endif re_free (dfa->subexp_map); #ifdef DEBUG re_free (dfa->re_str); #endif re_free (dfa); } /* Free dynamically allocated space used by PREG. */ void regfree (regex_t *preg) { re_dfa_t *dfa = (re_dfa_t *) preg->buffer; if (BE (dfa != NULL, 1)) free_dfa_content (dfa); preg->buffer = NULL; preg->allocated = 0; re_free (preg->fastmap); preg->fastmap = NULL; re_free (preg->translate); preg->translate = NULL; } #ifdef _LIBC weak_alias (__regfree, regfree) #endif /* Entry points compatible with 4.2 BSD regex library. We don't define them unless specifically requested. */ #if defined _REGEX_RE_COMP || defined _LIBC /* BSD has one and only one pattern buffer. */ static struct re_pattern_buffer re_comp_buf; char * # ifdef _LIBC /* Make these definitions weak in libc, so POSIX programs can redefine these names if they don't use our functions, and still use regcomp/regexec above without link errors. */ weak_function # endif re_comp (s) const char *s; { reg_errcode_t ret; char *fastmap; if (!s) { if (!re_comp_buf.buffer) return gettext ("No previous regular expression"); return 0; } if (re_comp_buf.buffer) { fastmap = re_comp_buf.fastmap; re_comp_buf.fastmap = NULL; __regfree (&re_comp_buf); memset (&re_comp_buf, '\0', sizeof (re_comp_buf)); re_comp_buf.fastmap = fastmap; } if (re_comp_buf.fastmap == NULL) { re_comp_buf.fastmap = (char *) malloc (SBC_MAX); if (re_comp_buf.fastmap == NULL) return (char *) gettext (__re_error_msgid + __re_error_msgid_idx[(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 = re_compile_internal (&re_comp_buf, s, strlen (s), re_syntax_options); if (!ret) return NULL; /* Yes, we're discarding `const' here if !HAVE_LIBINTL. */ return (char *) gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]); } #ifdef _LIBC libc_freeres_fn (free_mem) { __regfree (&re_comp_buf); } #endif #endif /* _REGEX_RE_COMP */ /* Internal entry point. Compile the regular expression PATTERN, whose length is LENGTH. SYNTAX indicate regular expression's syntax. */ static reg_errcode_t re_compile_internal (regex_t *preg, const char * pattern, size_t length, reg_syntax_t syntax) { reg_errcode_t err = REG_NOERROR; re_dfa_t *dfa; re_string_t regexp; /* Initialize the pattern buffer. */ preg->fastmap_accurate = 0; preg->syntax = syntax; preg->not_bol = preg->not_eol = 0; preg->used = 0; preg->re_nsub = 0; preg->can_be_null = 0; preg->regs_allocated = REGS_UNALLOCATED; /* Initialize the dfa. */ dfa = (re_dfa_t *) preg->buffer; if (BE (preg->allocated < sizeof (re_dfa_t), 0)) { /* 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. If ->buffer is NULL this is a simple allocation. */ dfa = re_realloc (preg->buffer, re_dfa_t, 1); if (dfa == NULL) return REG_ESPACE; preg->allocated = sizeof (re_dfa_t); preg->buffer = (unsigned char *) dfa; } preg->used = sizeof (re_dfa_t); err = init_dfa (dfa, length); if (BE (err != REG_NOERROR, 0)) { free_dfa_content (dfa); preg->buffer = NULL; preg->allocated = 0; return err; } #ifdef DEBUG /* Note: length+1 will not overflow since it is checked in init_dfa. */ dfa->re_str = re_malloc (char, length + 1); strncpy (dfa->re_str, pattern, length + 1); #endif __libc_lock_init (dfa->lock); err = re_string_construct (®exp, pattern, length, preg->translate, syntax & RE_ICASE, dfa); if (BE (err != REG_NOERROR, 0)) { re_compile_internal_free_return: free_workarea_compile (preg); re_string_destruct (®exp); free_dfa_content (dfa); preg->buffer = NULL; preg->allocated = 0; return err; } /* Parse the regular expression, and build a structure tree. */ preg->re_nsub = 0; dfa->str_tree = parse (®exp, preg, syntax, &err); if (BE (dfa->str_tree == NULL, 0)) goto re_compile_internal_free_return; /* Analyze the tree and create the nfa. */ err = analyze (preg); if (BE (err != REG_NOERROR, 0)) goto re_compile_internal_free_return; #ifdef RE_ENABLE_I18N /* If possible, do searching in single byte encoding to speed things up. */ if (dfa->is_utf8 && !(syntax & RE_ICASE) && preg->translate == NULL) optimize_utf8 (dfa); #endif /* Then create the initial state of the dfa. */ err = create_initial_state (dfa); /* Release work areas. */ free_workarea_compile (preg); re_string_destruct (®exp); if (BE (err != REG_NOERROR, 0)) { free_dfa_content (dfa); preg->buffer = NULL; preg->allocated = 0; } return err; } /* Initialize DFA. We use the length of the regular expression PAT_LEN as the initial length of some arrays. */ static reg_errcode_t init_dfa (re_dfa_t *dfa, size_t pat_len) { unsigned int table_size; #ifndef _LIBC char *codeset_name; #endif memset (dfa, '\0', sizeof (re_dfa_t)); /* Force allocation of str_tree_storage the first time. */ dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE; /* Avoid overflows. */ if (pat_len == SIZE_MAX) return REG_ESPACE; dfa->nodes_alloc = pat_len + 1; dfa->nodes = re_malloc (re_token_t, dfa->nodes_alloc); /* table_size = 2 ^ ceil(log pat_len) */ for (table_size = 1; ; table_size <<= 1) if (table_size > pat_len) break; dfa->state_table = calloc (sizeof (struct re_state_table_entry), table_size); dfa->state_hash_mask = table_size - 1; dfa->mb_cur_max = MB_CUR_MAX; #ifdef _LIBC if (dfa->mb_cur_max == 6 && strcmp (_NL_CURRENT (LC_CTYPE, _NL_CTYPE_CODESET_NAME), "UTF-8") == 0) dfa->is_utf8 = 1; dfa->map_notascii = (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_MAP_TO_NONASCII) != 0); #else # ifdef HAVE_LANGINFO_CODESET codeset_name = nl_langinfo (CODESET); # else codeset_name = getenv ("LC_ALL"); if (codeset_name == NULL || codeset_name[0] == '\0') codeset_name = getenv ("LC_CTYPE"); if (codeset_name == NULL || codeset_name[0] == '\0') codeset_name = getenv ("LANG"); if (codeset_name == NULL) codeset_name = ""; else if (strchr (codeset_name, '.') != NULL) codeset_name = strchr (codeset_name, '.') + 1; # endif /* strcasecmp isn't a standard interface. brute force check */ #if 0 if (strcasecmp (codeset_name, "UTF-8") == 0 || strcasecmp (codeset_name, "UTF8") == 0) dfa->is_utf8 = 1; #else if ( (codeset_name[0] == 'U' || codeset_name[0] == 'u') && (codeset_name[1] == 'T' || codeset_name[1] == 't') && (codeset_name[2] == 'F' || codeset_name[2] == 'f') && (codeset_name[3] == '-' ? codeset_name[4] == '8' && codeset_name[5] == '\0' : codeset_name[3] == '8' && codeset_name[4] == '\0')) dfa->is_utf8 = 1; #endif /* We check exhaustively in the loop below if this charset is a superset of ASCII. */ dfa->map_notascii = 0; #endif #ifdef RE_ENABLE_I18N if (dfa->mb_cur_max > 1) { if (dfa->is_utf8) { #if !defined(__GNUC__) || __GNUC__ < 3 static short utf8_sb_map_inited = 0; if (! utf8_sb_map_inited) { int i; utf8_sb_map_inited = 0; for (i = 0; i <= 0x80 / BITSET_WORD_BITS - 1; i++) utf8_sb_map[i] = BITSET_WORD_MAX; } #endif dfa->sb_char = (re_bitset_ptr_t) utf8_sb_map; } else { int i, j, ch; dfa->sb_char = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1); if (BE (dfa->sb_char == NULL, 0)) return REG_ESPACE; /* Set the bits corresponding to single byte chars. */ for (i = 0, ch = 0; i < BITSET_WORDS; ++i) for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch) { wint_t wch = __btowc (ch); if (wch != WEOF) dfa->sb_char[i] |= (bitset_word_t) 1 << j; # ifndef _LIBC if (isascii (ch) && wch != ch) dfa->map_notascii = 1; # endif } } } #endif if (BE (dfa->nodes == NULL || dfa->state_table == NULL, 0)) return REG_ESPACE; return REG_NOERROR; } /* Initialize WORD_CHAR table, which indicate which character is "word". In this case "word" means that it is the word construction character used by some operators like "\<", "\>", etc. */ static void internal_function init_word_char (re_dfa_t *dfa) { int i, j, ch; dfa->word_ops_used = 1; for (i = 0, ch = 0; i < BITSET_WORDS; ++i) for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch) if (isalnum (ch) || ch == '_') dfa->word_char[i] |= (bitset_word_t) 1 << j; } /* Free the work area which are only used while compiling. */ static void free_workarea_compile (regex_t *preg) { re_dfa_t *dfa = (re_dfa_t *) preg->buffer; bin_tree_storage_t *storage, *next; for (storage = dfa->str_tree_storage; storage; storage = next) { next = storage->next; re_free (storage); } dfa->str_tree_storage = NULL; dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE; dfa->str_tree = NULL; re_free (dfa->org_indices); dfa->org_indices = NULL; } /* Create initial states for all contexts. */ static reg_errcode_t create_initial_state (re_dfa_t *dfa) { int first, i; reg_errcode_t err; re_node_set init_nodes; /* Initial states have the epsilon closure of the node which is the first node of the regular expression. */ first = dfa->str_tree->first->node_idx; dfa->init_node = first; err = re_node_set_init_copy (&init_nodes, dfa->eclosures + first); if (BE (err != REG_NOERROR, 0)) return err; /* The back-references which are in initial states can epsilon transit, since in this case all of the subexpressions can be null. Then we add epsilon closures of the nodes which are the next nodes of the back-references. */ if (dfa->nbackref > 0) for (i = 0; i < init_nodes.nelem; ++i) { int node_idx = init_nodes.elems[i]; re_token_type_t type = dfa->nodes[node_idx].type; int clexp_idx; if (type != OP_BACK_REF) continue; for (clexp_idx = 0; clexp_idx < init_nodes.nelem; ++clexp_idx) { re_token_t *clexp_node; clexp_node = dfa->nodes + init_nodes.elems[clexp_idx]; if (clexp_node->type == OP_CLOSE_SUBEXP && clexp_node->opr.idx == dfa->nodes[node_idx].opr.idx) break; } if (clexp_idx == init_nodes.nelem) continue; if (type == OP_BACK_REF) { int dest_idx = dfa->edests[node_idx].elems[0]; if (!re_node_set_contains (&init_nodes, dest_idx)) { reg_errcode_t err = re_node_set_merge (&init_nodes, dfa->eclosures + dest_idx); if (err != REG_NOERROR) return err; i = 0; } } } /* It must be the first time to invoke acquire_state. */ dfa->init_state = re_acquire_state_context (&err, dfa, &init_nodes, 0); /* We don't check ERR here, since the initial state must not be NULL. */ if (BE (dfa->init_state == NULL, 0)) return err; if (dfa->init_state->has_constraint) { dfa->init_state_word = re_acquire_state_context (&err, dfa, &init_nodes, CONTEXT_WORD); dfa->init_state_nl = re_acquire_state_context (&err, dfa, &init_nodes, CONTEXT_NEWLINE); dfa->init_state_begbuf = re_acquire_state_context (&err, dfa, &init_nodes, CONTEXT_NEWLINE | CONTEXT_BEGBUF); if (BE (dfa->init_state_word == NULL || dfa->init_state_nl == NULL || dfa->init_state_begbuf == NULL, 0)) return err; } else dfa->init_state_word = dfa->init_state_nl = dfa->init_state_begbuf = dfa->init_state; re_node_set_free (&init_nodes); return REG_NOERROR; } #ifdef RE_ENABLE_I18N /* If it is possible to do searching in single byte encoding instead of UTF-8 to speed things up, set dfa->mb_cur_max to 1, clear is_utf8 and change DFA nodes where needed. */ static void optimize_utf8 (re_dfa_t *dfa) { int node, i, mb_chars = 0, has_period = 0; for (node = 0; node < dfa->nodes_len; ++node) switch (dfa->nodes[node].type) { case CHARACTER: if (dfa->nodes[node].opr.c >= 0x80) mb_chars = 1; break; case ANCHOR: switch (dfa->nodes[node].opr.ctx_type) { case LINE_FIRST: case LINE_LAST: case BUF_FIRST: case BUF_LAST: break; default: /* Word anchors etc. cannot be handled. It's okay to test opr.ctx_type since constraints (for all DFA nodes) are created by ORing one or more opr.ctx_type values. */ return; } break; case OP_PERIOD: has_period = 1; break; case OP_BACK_REF: case OP_ALT: case END_OF_RE: case OP_DUP_ASTERISK: case OP_OPEN_SUBEXP: case OP_CLOSE_SUBEXP: break; case COMPLEX_BRACKET: return; case SIMPLE_BRACKET: /* Just double check. The non-ASCII range starts at 0x80. */ assert (0x80 % BITSET_WORD_BITS == 0); for (i = 0x80 / BITSET_WORD_BITS; i < BITSET_WORDS; ++i) if (dfa->nodes[node].opr.sbcset[i]) return; break; default: abort (); } if (mb_chars || has_period) for (node = 0; node < dfa->nodes_len; ++node) { if (dfa->nodes[node].type == CHARACTER && dfa->nodes[node].opr.c >= 0x80) dfa->nodes[node].mb_partial = 0; else if (dfa->nodes[node].type == OP_PERIOD) dfa->nodes[node].type = OP_UTF8_PERIOD; } /* The search can be in single byte locale. */ dfa->mb_cur_max = 1; dfa->is_utf8 = 0; dfa->has_mb_node = dfa->nbackref > 0 || has_period; } #endif /* Analyze the structure tree, and calculate "first", "next", "edest", "eclosure", and "inveclosure". */ static reg_errcode_t analyze (regex_t *preg) { re_dfa_t *dfa = (re_dfa_t *) preg->buffer; reg_errcode_t ret; /* Allocate arrays. */ dfa->nexts = re_malloc (int, dfa->nodes_alloc); dfa->org_indices = re_malloc (int, dfa->nodes_alloc); dfa->edests = re_malloc (re_node_set, dfa->nodes_alloc); dfa->eclosures = re_malloc (re_node_set, dfa->nodes_alloc); if (BE (dfa->nexts == NULL || dfa->org_indices == NULL || dfa->edests == NULL || dfa->eclosures == NULL, 0)) return REG_ESPACE; dfa->subexp_map = re_malloc (int, preg->re_nsub); if (dfa->subexp_map != NULL) { int i; for (i = 0; i < preg->re_nsub; i++) dfa->subexp_map[i] = i; preorder (dfa->str_tree, optimize_subexps, dfa); for (i = 0; i < preg->re_nsub; i++) if (dfa->subexp_map[i] != i) break; if (i == preg->re_nsub) { free (dfa->subexp_map); dfa->subexp_map = NULL; } } ret = postorder (dfa->str_tree, lower_subexps, preg); if (BE (ret != REG_NOERROR, 0)) return ret; ret = postorder (dfa->str_tree, calc_first, dfa); if (BE (ret != REG_NOERROR, 0)) return ret; preorder (dfa->str_tree, calc_next, dfa); ret = preorder (dfa->str_tree, link_nfa_nodes, dfa); if (BE (ret != REG_NOERROR, 0)) return ret; ret = calc_eclosure (dfa); if (BE (ret != REG_NOERROR, 0)) return ret; /* We only need this during the prune_impossible_nodes pass in regexec.c; skip it if p_i_n will not run, as calc_inveclosure can be quadratic. */ if ((!preg->no_sub && preg->re_nsub > 0 && dfa->has_plural_match) || dfa->nbackref) { dfa->inveclosures = re_malloc (re_node_set, dfa->nodes_len); if (BE (dfa->inveclosures == NULL, 0)) return REG_ESPACE; ret = calc_inveclosure (dfa); } return ret; } /* Our parse trees are very unbalanced, so we cannot use a stack to implement parse tree visits. Instead, we use parent pointers and some hairy code in these two functions. */ static reg_errcode_t postorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)), void *extra) { bin_tree_t *node, *prev; for (node = root; ; ) { /* Descend down the tree, preferably to the left (or to the right if that's the only child). */ while (node->left || node->right) if (node->left) node = node->left; else node = node->right; do { reg_errcode_t err = fn (extra, node); if (BE (err != REG_NOERROR, 0)) return err; if (node->parent == NULL) return REG_NOERROR; prev = node; node = node->parent; } /* Go up while we have a node that is reached from the right. */ while (node->right == prev || node->right == NULL); node = node->right; } } static reg_errcode_t preorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)), void *extra) { bin_tree_t *node; for (node = root; ; ) { reg_errcode_t err = fn (extra, node); if (BE (err != REG_NOERROR, 0)) return err; /* Go to the left node, or up and to the right. */ if (node->left) node = node->left; else { bin_tree_t *prev = NULL; while (node->right == prev || node->right == NULL) { prev = node; node = node->parent; if (!node) return REG_NOERROR; } node = node->right; } } } /* Optimization pass: if a SUBEXP is entirely contained, strip it and tell re_search_internal to map the inner one's opr.idx to this one's. Adjust backreferences as well. Requires a preorder visit. */ static reg_errcode_t optimize_subexps (void *extra, bin_tree_t *node) { re_dfa_t *dfa = (re_dfa_t *) extra; if (node->token.type == OP_BACK_REF && dfa->subexp_map) { int idx = node->token.opr.idx; node->token.opr.idx = dfa->subexp_map[idx]; dfa->used_bkref_map |= 1 << node->token.opr.idx; } else if (node->token.type == SUBEXP && node->left && node->left->token.type == SUBEXP) { int other_idx = node->left->token.opr.idx; node->left = node->left->left; if (node->left) node->left->parent = node; dfa->subexp_map[other_idx] = dfa->subexp_map[node->token.opr.idx]; if (other_idx < BITSET_WORD_BITS) dfa->used_bkref_map &= ~((bitset_word_t) 1 << other_idx); } return REG_NOERROR; } /* Lowering pass: Turn each SUBEXP node into the appropriate concatenation of OP_OPEN_SUBEXP, the body of the SUBEXP (if any) and OP_CLOSE_SUBEXP. */ static reg_errcode_t lower_subexps (void *extra, bin_tree_t *node) { regex_t *preg = (regex_t *) extra; reg_errcode_t err = REG_NOERROR; if (node->left && node->left->token.type == SUBEXP) { node->left = lower_subexp (&err, preg, node->left); if (node->left) node->left->parent = node; } if (node->right && node->right->token.type == SUBEXP) { node->right = lower_subexp (&err, preg, node->right); if (node->right) node->right->parent = node; } return err; } static bin_tree_t * lower_subexp (reg_errcode_t *err, regex_t *preg, bin_tree_t *node) { re_dfa_t *dfa = (re_dfa_t *) preg->buffer; bin_tree_t *body = node->left; bin_tree_t *op, *cls, *tree1, *tree; if (preg->no_sub /* We do not optimize empty subexpressions, because otherwise we may have bad CONCAT nodes with NULL children. This is obviously not very common, so we do not lose much. An example that triggers this case is the sed "script" /\(\)/x. */ && node->left != NULL && (node->token.opr.idx >= BITSET_WORD_BITS || !(dfa->used_bkref_map & ((bitset_word_t) 1 << node->token.opr.idx)))) return node->left; /* Convert the SUBEXP node to the concatenation of an OP_OPEN_SUBEXP, the contents, and an OP_CLOSE_SUBEXP. */ op = create_tree (dfa, NULL, NULL, OP_OPEN_SUBEXP); cls = create_tree (dfa, NULL, NULL, OP_CLOSE_SUBEXP); tree1 = body ? create_tree (dfa, body, cls, CONCAT) : cls; tree = create_tree (dfa, op, tree1, CONCAT); if (BE (tree == NULL || tree1 == NULL || op == NULL || cls == NULL, 0)) { *err = REG_ESPACE; return NULL; } op->token.opr.idx = cls->token.opr.idx = node->token.opr.idx; op->token.opt_subexp = cls->token.opt_subexp = node->token.opt_subexp; return tree; } /* Pass 1 in building the NFA: compute FIRST and create unlinked automaton nodes. Requires a postorder visit. */ static reg_errcode_t calc_first (void *extra, bin_tree_t *node) { re_dfa_t *dfa = (re_dfa_t *) extra; if (node->token.type == CONCAT) { node->first = node->left->first; node->node_idx = node->left->node_idx; } else { node->first = node; node->node_idx = re_dfa_add_node (dfa, node->token); if (BE (node->node_idx == -1, 0)) return REG_ESPACE; if (node->token.type == ANCHOR) dfa->nodes[node->node_idx].constraint = node->token.opr.ctx_type; } return REG_NOERROR; } /* Pass 2: compute NEXT on the tree. Preorder visit. */ static reg_errcode_t calc_next (void *extra, bin_tree_t *node) { switch (node->token.type) { case OP_DUP_ASTERISK: node->left->next = node; break; case CONCAT: node->left->next = node->right->first; node->right->next = node->next; break; default: if (node->left) node->left->next = node->next; if (node->right) node->right->next = node->next; break; } return REG_NOERROR; } /* Pass 3: link all DFA nodes to their NEXT node (any order will do). */ static reg_errcode_t link_nfa_nodes (void *extra, bin_tree_t *node) { re_dfa_t *dfa = (re_dfa_t *) extra; int idx = node->node_idx; reg_errcode_t err = REG_NOERROR; switch (node->token.type) { case CONCAT: break; case END_OF_RE: assert (node->next == NULL); break; case OP_DUP_ASTERISK: case OP_ALT: { int left, right; dfa->has_plural_match = 1; if (node->left != NULL) left = node->left->first->node_idx; else left = node->next->node_idx; if (node->right != NULL) right = node->right->first->node_idx; else right = node->next->node_idx; assert (left > -1); assert (right > -1); err = re_node_set_init_2 (dfa->edests + idx, left, right); } break; case ANCHOR: case OP_OPEN_SUBEXP: case OP_CLOSE_SUBEXP: err = re_node_set_init_1 (dfa->edests + idx, node->next->node_idx); break; case OP_BACK_REF: dfa->nexts[idx] = node->next->node_idx; if (node->token.type == OP_BACK_REF) err = re_node_set_init_1 (dfa->edests + idx, dfa->nexts[idx]); break; default: assert (!IS_EPSILON_NODE (node->token.type)); dfa->nexts[idx] = node->next->node_idx; break; } return err; } /* Duplicate the epsilon closure of the node ROOT_NODE. Note that duplicated nodes have constraint INIT_CONSTRAINT in addition to their own constraint. */ static reg_errcode_t internal_function duplicate_node_closure (re_dfa_t *dfa, int top_org_node, int top_clone_node, int root_node, unsigned int init_constraint) { int org_node, clone_node, ret; unsigned int constraint = init_constraint; for (org_node = top_org_node, clone_node = top_clone_node;;) { int org_dest, clone_dest; if (dfa->nodes[org_node].type == OP_BACK_REF) { /* If the back reference epsilon-transit, its destination must also have the constraint. Then duplicate the epsilon closure of the destination of the back reference, and store it in edests of the back reference. */ org_dest = dfa->nexts[org_node]; re_node_set_empty (dfa->edests + clone_node); clone_dest = duplicate_node (dfa, org_dest, constraint); if (BE (clone_dest == -1, 0)) return REG_ESPACE; dfa->nexts[clone_node] = dfa->nexts[org_node]; ret = re_node_set_insert (dfa->edests + clone_node, clone_dest); if (BE (ret < 0, 0)) return REG_ESPACE; } else if (dfa->edests[org_node].nelem == 0) { /* In case of the node can't epsilon-transit, don't duplicate the destination and store the original destination as the destination of the node. */ dfa->nexts[clone_node] = dfa->nexts[org_node]; break; } else if (dfa->edests[org_node].nelem == 1) { /* In case of the node can epsilon-transit, and it has only one destination. */ org_dest = dfa->edests[org_node].elems[0]; re_node_set_empty (dfa->edests + clone_node); /* If the node is root_node itself, it means the epsilon clsoure has a loop. Then tie it to the destination of the root_node. */ if (org_node == root_node && clone_node != org_node) { ret = re_node_set_insert (dfa->edests + clone_node, org_dest); if (BE (ret < 0, 0)) return REG_ESPACE; break; } /* In case of the node has another constraint, add it. */ constraint |= dfa->nodes[org_node].constraint; clone_dest = duplicate_node (dfa, org_dest, constraint); if (BE (clone_dest == -1, 0)) return REG_ESPACE; ret = re_node_set_insert (dfa->edests + clone_node, clone_dest); if (BE (ret < 0, 0)) return REG_ESPACE; } else /* dfa->edests[org_node].nelem == 2 */ { /* In case of the node can epsilon-transit, and it has two destinations. In the bin_tree_t and DFA, that's '|' and '*'. */ org_dest = dfa->edests[org_node].elems[0]; re_node_set_empty (dfa->edests + clone_node); /* Search for a duplicated node which satisfies the constraint. */ clone_dest = search_duplicated_node (dfa, org_dest, constraint); if (clone_dest == -1) { /* There is no such duplicated node, create a new one. */ reg_errcode_t err; clone_dest = duplicate_node (dfa, org_dest, constraint); if (BE (clone_dest == -1, 0)) return REG_ESPACE; ret = re_node_set_insert (dfa->edests + clone_node, clone_dest); if (BE (ret < 0, 0)) return REG_ESPACE; err = duplicate_node_closure (dfa, org_dest, clone_dest, root_node, constraint); if (BE (err != REG_NOERROR, 0)) return err; } else { /* There is a duplicated node which satisfies the constraint, use it to avoid infinite loop. */ ret = re_node_set_insert (dfa->edests + clone_node, clone_dest); if (BE (ret < 0, 0)) return REG_ESPACE; } org_dest = dfa->edests[org_node].elems[1]; clone_dest = duplicate_node (dfa, org_dest, constraint); if (BE (clone_dest == -1, 0)) return REG_ESPACE; ret = re_node_set_insert (dfa->edests + clone_node, clone_dest); if (BE (ret < 0, 0)) return REG_ESPACE; } org_node = org_dest; clone_node = clone_dest; } return REG_NOERROR; } /* Search for a node which is duplicated from the node ORG_NODE, and satisfies the constraint CONSTRAINT. */ static int search_duplicated_node (const re_dfa_t *dfa, int org_node, unsigned int constraint) { int idx; for (idx = dfa->nodes_len - 1; dfa->nodes[idx].duplicated && idx > 0; --idx) { if (org_node == dfa->org_indices[idx] && constraint == dfa->nodes[idx].constraint) return idx; /* Found. */ } return -1; /* Not found. */ } /* Duplicate the node whose index is ORG_IDX and set the constraint CONSTRAINT. Return the index of the new node, or -1 if insufficient storage is available. */ static int duplicate_node (re_dfa_t *dfa, int org_idx, unsigned int constraint) { int dup_idx = re_dfa_add_node (dfa, dfa->nodes[org_idx]); if (BE (dup_idx != -1, 1)) { dfa->nodes[dup_idx].constraint = constraint; dfa->nodes[dup_idx].constraint |= dfa->nodes[org_idx].constraint; dfa->nodes[dup_idx].duplicated = 1; /* Store the index of the original node. */ dfa->org_indices[dup_idx] = org_idx; } return dup_idx; } static reg_errcode_t calc_inveclosure (re_dfa_t *dfa) { int src, idx, ret; for (idx = 0; idx < dfa->nodes_len; ++idx) re_node_set_init_empty (dfa->inveclosures + idx); for (src = 0; src < dfa->nodes_len; ++src) { int *elems = dfa->eclosures[src].elems; for (idx = 0; idx < dfa->eclosures[src].nelem; ++idx) { ret = re_node_set_insert_last (dfa->inveclosures + elems[idx], src); if (BE (ret == -1, 0)) return REG_ESPACE; } } return REG_NOERROR; } /* Calculate "eclosure" for all the node in DFA. */ static reg_errcode_t calc_eclosure (re_dfa_t *dfa) { int node_idx, incomplete; #ifdef DEBUG assert (dfa->nodes_len > 0); #endif incomplete = 0; /* For each nodes, calculate epsilon closure. */ for (node_idx = 0; ; ++node_idx) { reg_errcode_t err; re_node_set eclosure_elem; if (node_idx == dfa->nodes_len) { if (!incomplete) break; incomplete = 0; node_idx = 0; } #ifdef DEBUG assert (dfa->eclosures[node_idx].nelem != -1); #endif /* If we have already calculated, skip it. */ if (dfa->eclosures[node_idx].nelem != 0) continue; /* Calculate epsilon closure of `node_idx'. */ err = calc_eclosure_iter (&eclosure_elem, dfa, node_idx, 1); if (BE (err != REG_NOERROR, 0)) return err; if (dfa->eclosures[node_idx].nelem == 0) { incomplete = 1; re_node_set_free (&eclosure_elem); } } return REG_NOERROR; } /* Calculate epsilon closure of NODE. */ static reg_errcode_t calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, int node, int root) { reg_errcode_t err; int i; re_node_set eclosure; int ret; int incomplete = 0; err = re_node_set_alloc (&eclosure, dfa->edests[node].nelem + 1); if (BE (err != REG_NOERROR, 0)) return err; /* This indicates that we are calculating this node now. We reference this value to avoid infinite loop. */ dfa->eclosures[node].nelem = -1; /* If the current node has constraints, duplicate all nodes since they must inherit the constraints. */ if (dfa->nodes[node].constraint && dfa->edests[node].nelem && !dfa->nodes[dfa->edests[node].elems[0]].duplicated) { err = duplicate_node_closure (dfa, node, node, node, dfa->nodes[node].constraint); if (BE (err != REG_NOERROR, 0)) return err; } /* Expand each epsilon destination nodes. */ if (IS_EPSILON_NODE(dfa->nodes[node].type)) for (i = 0; i < dfa->edests[node].nelem; ++i) { re_node_set eclosure_elem; int edest = dfa->edests[node].elems[i]; /* If calculating the epsilon closure of `edest' is in progress, return intermediate result. */ if (dfa->eclosures[edest].nelem == -1) { incomplete = 1; continue; } /* If we haven't calculated the epsilon closure of `edest' yet, calculate now. Otherwise use calculated epsilon closure. */ if (dfa->eclosures[edest].nelem == 0) { err = calc_eclosure_iter (&eclosure_elem, dfa, edest, 0); if (BE (err != REG_NOERROR, 0)) return err; } else eclosure_elem = dfa->eclosures[edest]; /* Merge the epsilon closure of `edest'. */ err = re_node_set_merge (&eclosure, &eclosure_elem); if (BE (err != REG_NOERROR, 0)) return err; /* If the epsilon closure of `edest' is incomplete, the epsilon closure of this node is also incomplete. */ if (dfa->eclosures[edest].nelem == 0) { incomplete = 1; re_node_set_free (&eclosure_elem); } } /* An epsilon closure includes itself. */ ret = re_node_set_insert (&eclosure, node); if (BE (ret < 0, 0)) return REG_ESPACE; if (incomplete && !root) dfa->eclosures[node].nelem = 0; else dfa->eclosures[node] = eclosure; *new_set = eclosure; return REG_NOERROR; } /* Functions for token which are used in the parser. */ /* Fetch a token from INPUT. We must not use this function inside bracket expressions. */ static void internal_function fetch_token (re_token_t *result, re_string_t *input, reg_syntax_t syntax) { re_string_skip_bytes (input, peek_token (result, input, syntax)); } /* Peek a token from INPUT, and return the length of the token. We must not use this function inside bracket expressions. */ static int internal_function peek_token (re_token_t *token, re_string_t *input, reg_syntax_t syntax) { unsigned char c; if (re_string_eoi (input)) { token->type = END_OF_RE; return 0; } c = re_string_peek_byte (input, 0); token->opr.c = c; token->word_char = 0; #ifdef RE_ENABLE_I18N token->mb_partial = 0; if (input->mb_cur_max > 1 && !re_string_first_byte (input, re_string_cur_idx (input))) { token->type = CHARACTER; token->mb_partial = 1; return 1; } #endif if (c == '\\') { unsigned char c2; if (re_string_cur_idx (input) + 1 >= re_string_length (input)) { token->type = BACK_SLASH; return 1; } c2 = re_string_peek_byte_case (input, 1); token->opr.c = c2; token->type = CHARACTER; #ifdef RE_ENABLE_I18N if (input->mb_cur_max > 1) { wint_t wc = re_string_wchar_at (input, re_string_cur_idx (input) + 1); token->word_char = IS_WIDE_WORD_CHAR (wc) != 0; } else #endif token->word_char = IS_WORD_CHAR (c2) != 0; switch (c2) { case '|': if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_NO_BK_VBAR)) token->type = OP_ALT; 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)) { token->type = OP_BACK_REF; token->opr.idx = c2 - '1'; } break; case '<': if (!(syntax & RE_NO_GNU_OPS)) { token->type = ANCHOR; token->opr.ctx_type = WORD_FIRST; } break; case '>': if (!(syntax & RE_NO_GNU_OPS)) { token->type = ANCHOR; token->opr.ctx_type = WORD_LAST; } break; case 'b': if (!(syntax & RE_NO_GNU_OPS)) { token->type = ANCHOR; token->opr.ctx_type = WORD_DELIM; } break; case 'B': if (!(syntax & RE_NO_GNU_OPS)) { token->type = ANCHOR; token->opr.ctx_type = NOT_WORD_DELIM; } break; case 'w': if (!(syntax & RE_NO_GNU_OPS)) token->type = OP_WORD; break; case 'W': if (!(syntax & RE_NO_GNU_OPS)) token->type = OP_NOTWORD; break; case 's': if (!(syntax & RE_NO_GNU_OPS)) token->type = OP_SPACE; break; case 'S': if (!(syntax & RE_NO_GNU_OPS)) token->type = OP_NOTSPACE; break; case '`': if (!(syntax & RE_NO_GNU_OPS)) { token->type = ANCHOR; token->opr.ctx_type = BUF_FIRST; } break; case '\'': if (!(syntax & RE_NO_GNU_OPS)) { token->type = ANCHOR; token->opr.ctx_type = BUF_LAST; } break; case '(': if (!(syntax & RE_NO_BK_PARENS)) token->type = OP_OPEN_SUBEXP; break; case ')': if (!(syntax & RE_NO_BK_PARENS)) token->type = OP_CLOSE_SUBEXP; break; case '+': if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM)) token->type = OP_DUP_PLUS; break; case '?': if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM)) token->type = OP_DUP_QUESTION; break; case '{': if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES))) token->type = OP_OPEN_DUP_NUM; break; case '}': if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES))) token->type = OP_CLOSE_DUP_NUM; break; default: break; } return 2; } token->type = CHARACTER; #ifdef RE_ENABLE_I18N if (input->mb_cur_max > 1) { wint_t wc = re_string_wchar_at (input, re_string_cur_idx (input)); token->word_char = IS_WIDE_WORD_CHAR (wc) != 0; } else #endif token->word_char = IS_WORD_CHAR (token->opr.c); switch (c) { case '\n': if (syntax & RE_NEWLINE_ALT) token->type = OP_ALT; break; case '|': if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_NO_BK_VBAR)) token->type = OP_ALT; break; case '*': token->type = OP_DUP_ASTERISK; break; case '+': if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM)) token->type = OP_DUP_PLUS; break; case '?': if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM)) token->type = OP_DUP_QUESTION; break; case '{': if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES)) token->type = OP_OPEN_DUP_NUM; break; case '}': if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES)) token->type = OP_CLOSE_DUP_NUM; break; case '(': if (syntax & RE_NO_BK_PARENS) token->type = OP_OPEN_SUBEXP; break; case ')': if (syntax & RE_NO_BK_PARENS) token->type = OP_CLOSE_SUBEXP; break; case '[': token->type = OP_OPEN_BRACKET; break; case '.': token->type = OP_PERIOD; break; case '^': if (!(syntax & (RE_CONTEXT_INDEP_ANCHORS | RE_CARET_ANCHORS_HERE)) && re_string_cur_idx (input) != 0) { char prev = re_string_peek_byte (input, -1); if (!(syntax & RE_NEWLINE_ALT) || prev != '\n') break; } token->type = ANCHOR; token->opr.ctx_type = LINE_FIRST; break; case '$': if (!(syntax & RE_CONTEXT_INDEP_ANCHORS) && re_string_cur_idx (input) + 1 != re_string_length (input)) { re_token_t next; re_string_skip_bytes (input, 1); peek_token (&next, input, syntax); re_string_skip_bytes (input, -1); if (next.type != OP_ALT && next.type != OP_CLOSE_SUBEXP) break; } token->type = ANCHOR; token->opr.ctx_type = LINE_LAST; break; default: break; } return 1; } /* Peek a token from INPUT, and return the length of the token. We must not use this function out of bracket expressions. */ static int internal_function peek_token_bracket (re_token_t *token, re_string_t *input, reg_syntax_t syntax) { unsigned char c; if (re_string_eoi (input)) { token->type = END_OF_RE; return 0; } c = re_string_peek_byte (input, 0); token->opr.c = c; #ifdef RE_ENABLE_I18N if (input->mb_cur_max > 1 && !re_string_first_byte (input, re_string_cur_idx (input))) { token->type = CHARACTER; return 1; } #endif /* RE_ENABLE_I18N */ if (c == '\\' && (syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && re_string_cur_idx (input) + 1 < re_string_length (input)) { /* In this case, '\' escape a character. */ unsigned char c2; re_string_skip_bytes (input, 1); c2 = re_string_peek_byte (input, 0); token->opr.c = c2; token->type = CHARACTER; return 1; } if (c == '[') /* '[' is a special char in a bracket exps. */ { unsigned char c2; int token_len; if (re_string_cur_idx (input) + 1 < re_string_length (input)) c2 = re_string_peek_byte (input, 1); else c2 = 0; token->opr.c = c2; token_len = 2; switch (c2) { case '.': token->type = OP_OPEN_COLL_ELEM; break; case '=': token->type = OP_OPEN_EQUIV_CLASS; break; case ':': if (syntax & RE_CHAR_CLASSES) { token->type = OP_OPEN_CHAR_CLASS; break; } /* else fall through. */ default: token->type = CHARACTER; token->opr.c = c; token_len = 1; break; } return token_len; } switch (c) { case '-': token->type = OP_CHARSET_RANGE; break; case ']': token->type = OP_CLOSE_BRACKET; break; case '^': token->type = OP_NON_MATCH_LIST; break; default: token->type = CHARACTER; } return 1; } /* Functions for parser. */ /* Entry point of the parser. Parse the regular expression REGEXP and return the structure tree. If an error has occurred, ERR is set by error code, and return NULL. This function build the following tree, from regular expression : CAT / \ / \ EOR CAT means concatenation. EOR means end of regular expression. */ static bin_tree_t * parse (re_string_t *regexp, regex_t *preg, reg_syntax_t syntax, reg_errcode_t *err) { re_dfa_t *dfa = (re_dfa_t *) preg->buffer; bin_tree_t *tree, *eor, *root; re_token_t current_token; dfa->syntax = syntax; fetch_token (¤t_token, regexp, syntax | RE_CARET_ANCHORS_HERE); tree = parse_reg_exp (regexp, preg, ¤t_token, syntax, 0, err); if (BE (*err != REG_NOERROR && tree == NULL, 0)) return NULL; eor = create_tree (dfa, NULL, NULL, END_OF_RE); if (tree != NULL) root = create_tree (dfa, tree, eor, CONCAT); else root = eor; if (BE (eor == NULL || root == NULL, 0)) { *err = REG_ESPACE; return NULL; } return root; } /* This function build the following tree, from regular expression |: ALT / \ / \ ALT means alternative, which represents the operator `|'. */ static bin_tree_t * parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token, reg_syntax_t syntax, int nest, reg_errcode_t *err) { re_dfa_t *dfa = (re_dfa_t *) preg->buffer; bin_tree_t *tree, *branch = NULL; tree = parse_branch (regexp, preg, token, syntax, nest, err); if (BE (*err != REG_NOERROR && tree == NULL, 0)) return NULL; while (token->type == OP_ALT) { fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE); if (token->type != OP_ALT && token->type != END_OF_RE && (nest == 0 || token->type != OP_CLOSE_SUBEXP)) { branch = parse_branch (regexp, preg, token, syntax, nest, err); if (BE (*err != REG_NOERROR && branch == NULL, 0)) return NULL; } else branch = NULL; tree = create_tree (dfa, tree, branch, OP_ALT); if (BE (tree == NULL, 0)) { *err = REG_ESPACE; return NULL; } } return tree; } /* This function build the following tree, from regular expression : CAT / \ / \ CAT means concatenation. */ static bin_tree_t * parse_branch (re_string_t *regexp, regex_t *preg, re_token_t *token, reg_syntax_t syntax, int nest, reg_errcode_t *err) { bin_tree_t *tree, *exp; re_dfa_t *dfa = (re_dfa_t *) preg->buffer; tree = parse_expression (regexp, preg, token, syntax, nest, err); if (BE (*err != REG_NOERROR && tree == NULL, 0)) return NULL; while (token->type != OP_ALT && token->type != END_OF_RE && (nest == 0 || token->type != OP_CLOSE_SUBEXP)) { exp = parse_expression (regexp, preg, token, syntax, nest, err); if (BE (*err != REG_NOERROR && exp == NULL, 0)) { return NULL; } if (tree != NULL && exp != NULL) { tree = create_tree (dfa, tree, exp, CONCAT); if (tree == NULL) { *err = REG_ESPACE; return NULL; } } else if (tree == NULL) tree = exp; /* Otherwise exp == NULL, we don't need to create new tree. */ } return tree; } /* This function build the following tree, from regular expression a*: * | a */ static bin_tree_t * parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token, reg_syntax_t syntax, int nest, reg_errcode_t *err) { re_dfa_t *dfa = (re_dfa_t *) preg->buffer; bin_tree_t *tree; switch (token->type) { case CHARACTER: tree = create_token_tree (dfa, NULL, NULL, token); if (BE (tree == NULL, 0)) { *err = REG_ESPACE; return NULL; } #ifdef RE_ENABLE_I18N if (dfa->mb_cur_max > 1) { while (!re_string_eoi (regexp) && !re_string_first_byte (regexp, re_string_cur_idx (regexp))) { bin_tree_t *mbc_remain; fetch_token (token, regexp, syntax); mbc_remain = create_token_tree (dfa, NULL, NULL, token); tree = create_tree (dfa, tree, mbc_remain, CONCAT); if (BE (mbc_remain == NULL || tree == NULL, 0)) { *err = REG_ESPACE; return NULL; } } } #endif break; case OP_OPEN_SUBEXP: tree = parse_sub_exp (regexp, preg, token, syntax, nest + 1, err); if (BE (*err != REG_NOERROR && tree == NULL, 0)) return