Mercurial > octave-nkf
view liboctave/util/lo-regexp.cc @ 16940:99122191d3dd
maint: Rename regexp.h to lo-regexp.h, regexp.cc to lo-regexp.cc in liboctave.
Remove namespace hit with regexp.cc in libinterp/corefcn.
* liboctave/util/lo-regexp.cc: Renamed from regexp.cc.
* liboctave/util/lo-regexp.h: Renamed from regexp.h.
* liboctave/util/module.mk: Add files to build system.
* libinterp/corefcn/regexp.cc, libinterp/corefcn/symtab.h,
libinterp/corefcn/variables.cc: Update #include stmts to new name.
author | Rik <rik@octave.org> |
---|---|
date | Tue, 09 Jul 2013 16:47:57 -0700 |
parents | liboctave/util/regexp.cc@1e9a6285acc4 |
children | 334d8edd48bc |
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/* Copyright (C) 2012 John W. Eaton Copyright (C) 2005-2012 David Bateman Copyright (C) 2002-2005 Paul Kienzle This file is part of Octave. Octave 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. Octave 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 Octave; see the file COPYING. If not, see <http://www.gnu.org/licenses/>. */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include <list> #include <sstream> #include <string> #include <vector> #if defined (HAVE_PCRE_H) #include <pcre.h> #elif defined (HAVE_PCRE_PCRE_H) #include <pcre/pcre.h> #endif #include "Matrix.h" #include "base-list.h" #include "lo-error.h" #include "oct-locbuf.h" #include "quit.h" #include "lo-regexp.h" #include "str-vec.h" // Define the maximum number of retries for a pattern that possibly // results in an infinite recursion. #define PCRE_MATCHLIMIT_MAX 10 // FIXME -- should this be configurable? #define MAXLOOKBEHIND 10 static bool lookbehind_warned = false; // FIXME -- don't bother collecting and composing return values the user // doesn't want. void regexp::free (void) { if (data) pcre_free (static_cast<pcre *> (data)); } void regexp::compile_internal (void) { // If we had a previously compiled pattern, release it. free (); size_t max_length = MAXLOOKBEHIND; size_t pos = 0; size_t new_pos; int inames = 0; std::ostringstream buf; while ((new_pos = pattern.find ("(?", pos)) != std::string::npos) { if (pattern.at (new_pos + 2) == '<' && !(pattern.at (new_pos + 3) == '=' || pattern.at (new_pos + 3) == '!')) { // The syntax of named tokens in pcre is "(?P<name>...)" while // we need a syntax "(?<name>...)", so fix that here. Also an // expression like // "(?<first>\w+)\s+(?<last>\w+)|(?<last>\w+),\s+(?<first>\w+)" // should be perfectly legal, while pcre does not allow the same // named token name on both sides of the alternative. Also fix // that here by replacing name tokens by dummy names, and dealing // with the dummy names later. size_t tmp_pos = pattern.find_first_of ('>', new_pos); if (tmp_pos == std::string::npos) { (*current_liboctave_error_handler) ("regexp: syntax error in pattern"); return; } std::string tmp_name = pattern.substr (new_pos+3, tmp_pos-new_pos-3); bool found = false; for (int i = 0; i < nnames; i++) { if (named_pats(i) == tmp_name) { named_idx.resize (dim_vector (inames+1, 1)); named_idx(inames) = i; found = true; break; } } if (! found) { named_idx.resize (dim_vector (inames+1, 1)); named_idx(inames) = nnames; named_pats.append (tmp_name); nnames++; } if (new_pos - pos > 0) buf << pattern.substr (pos, new_pos-pos); if (inames < 10) buf << "(?P<n00" << inames++; else if (inames < 100) buf << "(?P<n0" << inames++; else buf << "(?P<n" << inames++; pos = tmp_pos; } else if (pattern.at (new_pos + 2) == '<') { // Find lookbehind operators of arbitrary length (ie like // "(?<=[a-z]*)") and replace with a maximum length operator // as PCRE can not yet handle arbitrary length lookahead // operators. Use the string length as the maximum length to // avoid issues. int brackets = 1; size_t tmp_pos1 = new_pos + 2; size_t tmp_pos2 = tmp_pos1; while (tmp_pos1 < pattern.length () && brackets > 0) { char ch = pattern.at (tmp_pos1); if (ch == '(') brackets++; else if (ch == ')') { if (brackets > 1) tmp_pos2 = tmp_pos1; brackets--; } tmp_pos1++; } if (brackets != 0) { buf << pattern.substr (pos, new_pos - pos) << "(?"; pos = new_pos + 2; } else { size_t tmp_pos3 = pattern.find_first_of ("*+", tmp_pos2); if (tmp_pos3 != std::string::npos && tmp_pos3 < tmp_pos1) { if (!lookbehind_warned) { lookbehind_warned = true; (*current_liboctave_warning_handler) ("%s: arbitrary length lookbehind patterns are only supported up to length %d", who.c_str (), MAXLOOKBEHIND); } buf << pattern.substr (pos, new_pos - pos) << "("; size_t i; if (pattern.at (tmp_pos3) == '*') i = 0; else i = 1; for (; i < max_length + 1; i++) { buf << pattern.substr (new_pos, tmp_pos3 - new_pos) << "{" << i << "}"; buf << pattern.substr (tmp_pos3 + 1, tmp_pos1 - tmp_pos3 - 1); if (i != max_length) buf << "|"; } buf << ")"; } else buf << pattern.substr (pos, tmp_pos1 - pos); pos = tmp_pos1; } } else { buf << pattern.substr (pos, new_pos - pos) << "(?"; pos = new_pos + 2; } } buf << pattern.substr (pos); const char *err; int erroffset; std::string buf_str = buf.str (); int pcre_options = ((options.case_insensitive () ? PCRE_CASELESS : 0) | (options.dotexceptnewline () ? 0 : PCRE_DOTALL) | (options.lineanchors () ? PCRE_MULTILINE : 0) | (options.freespacing () ? PCRE_EXTENDED : 0)); data = pcre_compile (buf_str.c_str (), pcre_options, &err, &erroffset, 0); if (! data) (*current_liboctave_error_handler) ("%s: %s at position %d of expression", who.c_str (), err, erroffset); } regexp::match_data regexp::match (const std::string& buffer) { regexp::match_data retval; std::list<regexp::match_element> lst; int subpatterns; int namecount; int nameentrysize; char *nametable; size_t idx = 0; pcre *re = static_cast <pcre *> (data); pcre_fullinfo (re, 0, PCRE_INFO_CAPTURECOUNT, &subpatterns); pcre_fullinfo (re, 0, PCRE_INFO_NAMECOUNT, &namecount); pcre_fullinfo (re, 0, PCRE_INFO_NAMEENTRYSIZE, &nameentrysize); pcre_fullinfo (re, 0, PCRE_INFO_NAMETABLE, &nametable); OCTAVE_LOCAL_BUFFER (int, ovector, (subpatterns+1)*3); OCTAVE_LOCAL_BUFFER (int, nidx, namecount); for (int i = 0; i < namecount; i++) { // Index of subpattern in first two bytes MSB first of name. // Extract index. nidx[i] = (static_cast<int> (nametable[i*nameentrysize])) << 8 | static_cast<int> (nametable[i*nameentrysize+1]); } while (true) { OCTAVE_QUIT; int matches = pcre_exec (re, 0, buffer.c_str (), buffer.length (), idx, (idx ? PCRE_NOTBOL : 0), ovector, (subpatterns+1)*3); if (matches == PCRE_ERROR_MATCHLIMIT) { // Try harder; start with default value for MATCH_LIMIT // and increase it. (*current_liboctave_warning_handler) ("your pattern caused PCRE to hit its MATCH_LIMIT; trying harder now, but this will be slow"); pcre_extra pe; pcre_config (PCRE_CONFIG_MATCH_LIMIT, static_cast <void *> (&pe.match_limit)); pe.flags = PCRE_EXTRA_MATCH_LIMIT; int i = 0; while (matches == PCRE_ERROR_MATCHLIMIT && i++ < PCRE_MATCHLIMIT_MAX) { OCTAVE_QUIT; pe.match_limit *= 10; matches = pcre_exec (re, &pe, buffer.c_str (), buffer.length (), idx, (idx ? PCRE_NOTBOL : 0), ovector, (subpatterns+1)*3); } } if (matches < 0 && matches != PCRE_ERROR_NOMATCH) { (*current_liboctave_error_handler) ("%s: internal error calling pcre_exec; error code from pcre_exec is %i", who.c_str (), matches); return retval; } else if (matches == PCRE_ERROR_NOMATCH) break; else if (ovector[1] <= ovector[0] && ! options.emptymatch ()) { // Zero length match. Skip to next char. idx = ovector[0] + 1; if (idx < buffer.length ()) continue; else break; } else { int pos_match = 0; Matrix token_extents (matches-1, 2); for (int i = 1; i < matches; i++) { if (ovector[2*i] >= 0 && ovector[2*i+1] > 0 && (i == 1 || ovector[2*i] != ovector[2*i-2] || ovector[2*i-1] != ovector[2*i+1])) { token_extents(pos_match,0) = double (ovector[2*i]+1); token_extents(pos_match++,1) = double (ovector[2*i+1]); } } token_extents.resize (pos_match, 2); double start = double (ovector[0]+1); double end = double (ovector[1]); const char **listptr; int status = pcre_get_substring_list (buffer.c_str (), ovector, matches, &listptr); if (status == PCRE_ERROR_NOMEMORY) { (*current_liboctave_error_handler) ("%s: cannot allocate memory in pcre_get_substring_list", who.c_str ()); return retval; } string_vector tokens (pos_match); string_vector named_tokens (nnames); int pos_offset = 0; pos_match = 0; for (int i = 1; i < matches; i++) { if (ovector[2*i] >= 0 && ovector[2*i+1] > 0) { if (i == 1 || ovector[2*i] != ovector[2*i-2] || ovector[2*i-1] != ovector[2*i+1]) { if (namecount > 0) { // FIXME: Should probably do this with a map() // rather than a linear search. However, // the number of captured, named expressions // is usually pretty small (< 4) for (int j = 0; j < namecount; j++) { if (nidx[j] == i) { named_tokens(named_idx(j)) = std::string (*(listptr+i-pos_offset)); break; } } } tokens(pos_match++) = std::string (*(listptr+i)); } else pos_offset++; } } std::string match_string = std::string (*listptr); pcre_free_substring_list (listptr); regexp::match_element new_elem (named_tokens, tokens, match_string, token_extents, start, end); lst.push_back (new_elem); if (ovector[1] <= ovector[0]) { // Zero length match. Skip to next char. idx = ovector[0] + 1; if (idx <= buffer.length ()) continue; } else idx = ovector[1]; if (options.once () || idx >= buffer.length ()) break; } } retval = regexp::match_data (lst, named_pats); return retval; } bool regexp::is_match (const std::string& buffer) { regexp::match_data rx_lst = match (buffer); return rx_lst.size () > 0; } Array<bool> regexp::is_match (const string_vector& buffer) { octave_idx_type len = buffer.length (); Array<bool> retval (dim_vector (len, 1)); for (octave_idx_type i = 0; i < buffer.length (); i++) retval(i) = is_match (buffer(i)); return retval; } // Declare rep_token_t used in processing replacement string typedef struct { size_t pos; int num; } rep_token_t; std::string regexp::replace (const std::string& buffer, const std::string& replacement) { std::string retval; regexp::match_data rx_lst = match (buffer); size_t num_matches = rx_lst.size (); if (num_matches == 0) { retval = buffer; return retval; } // Identify replacement tokens; build a vector of group numbers in // the replacement string so that we can quickly calculate the size // of the replacement. // FIXME: All code assumes that only 10 tokens ($0-$9) exist. // $11 represents $1 followed by the character '1' rather than // the eleventh capture buffer. std::string repstr = replacement; std::vector<rep_token_t> tokens; tokens.reserve (5); // Reserve memory for 5 pattern replacements for (size_t i=0; i < repstr.size (); i++) { if (repstr[i] == '\\') { if (i < repstr.size () - 1 && repstr[i+1] == '$') { repstr.erase (i,1); // erase backslash i++; // skip over '$' continue; } if (i < repstr.size () - 1 && repstr[i+1] == '\\') { repstr.erase (i,1); // erase 1st backslash continue; } } else if (repstr[i] == '$') { if (i < repstr.size () - 1 && isdigit (repstr[i+1])) { rep_token_t tmp_token; tmp_token.pos = i; tmp_token.num = repstr[i+1]-'0'; tokens.push_back (tmp_token); } } } std::string rep; int num_tokens = tokens.size (); if (num_tokens > 0) { // Determine replacement length const size_t replen = repstr.size () - 2*num_tokens; int delta = 0; regexp::match_data::const_iterator p = rx_lst.begin (); for (size_t i = 0; i < num_matches; i++) { OCTAVE_QUIT; double start = p->start (); double end = p->end (); const Matrix pairs (p->token_extents ()); size_t pairlen = 0; for (int j = 0; j < num_tokens; j++) { if (tokens[j].num == 0) pairlen += static_cast<size_t> (end - start) + 1; else if (tokens[j].num <= pairs.rows ()) pairlen += static_cast<size_t> (pairs(tokens[j].num-1,1) - pairs(tokens[j].num-1,0)) + 1; } delta += (static_cast<int> (replen + pairlen) - static_cast<int> (end - start + 1)); p++; } // Build replacement string rep.reserve (buffer.size () + delta); size_t from = 0; p = rx_lst.begin (); for (size_t i = 0; i < num_matches; i++) { OCTAVE_QUIT; double start = p->start (); double end = p->end (); const Matrix pairs (p->token_extents ()); rep.append (&buffer[from], static_cast<size_t> (start - 1) - from); from = static_cast<size_t> (end - 1) + 1; size_t cur_pos = 0; for (int j = 0; j < num_tokens; j++) { rep.append (&repstr[cur_pos], (tokens[j].pos) - cur_pos); cur_pos = tokens[j].pos+2; int k = tokens[j].num; if (k == 0) { // replace with entire match rep.append (&buffer[static_cast<size_t> (end - 1)], static_cast<size_t> (end - start) + 1); } else if (k <= pairs.rows ()) { // replace with group capture rep.append (&buffer[static_cast<size_t> (pairs(k-1,0)-1)], static_cast<size_t> (pairs(k-1,1) - pairs(k-1,0)) + 1); } else { // replace with nothing } } if (cur_pos < repstr.size ()) rep.append (&repstr[cur_pos], repstr.size () - cur_pos); p++; } rep.append (&buffer[from], buffer.size () - from); } else { // Determine repstr length const size_t replen = repstr.size (); int delta = 0; regexp::match_data::const_iterator p = rx_lst.begin (); for (size_t i = 0; i < num_matches; i++) { OCTAVE_QUIT; delta += static_cast<int> (replen) - static_cast<int> (p->end () - p->start () + 1); p++; } // Build replacement string rep.reserve (buffer.size () + delta); size_t from = 0; p = rx_lst.begin (); for (size_t i = 0; i < num_matches; i++) { OCTAVE_QUIT; rep.append (&buffer[from], static_cast<size_t> (p->start () - 1) - from); from = static_cast<size_t> (p->end () - 1) + 1; rep.append (repstr); p++; } rep.append (&buffer[from], buffer.size () - from); } retval = rep; return retval; }