Mercurial > octave
view liboctave/util/lo-regexp.cc @ 32094:f3d12359f0e4
lo-regexp.cc: Avoid unused variable warning with PCRE2.
* liboctave/util/lo-regexp.cc (octave::regexp::match): Avoid warning about set
but unused variable when building with PCRE2.
author | Markus Mützel <markus.muetzel@gmx.de> |
---|---|
date | Sat, 13 May 2023 15:15:51 +0200 |
parents | 0fe37636be04 |
children | 2e484f9f1f18 |
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//////////////////////////////////////////////////////////////////////// // // Copyright (C) 2002-2023 The Octave Project Developers // // See the file COPYRIGHT.md in the top-level directory of this // distribution or <https://octave.org/copyright/>. // // 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 // <https://www.gnu.org/licenses/>. // //////////////////////////////////////////////////////////////////////// #if defined (HAVE_CONFIG_H) # include "config.h" #endif #include <list> #include <sstream> #include <string> #include <vector> #if defined (HAVE_PCRE2) # define PCRE2_CODE_UNIT_WIDTH 8 # if defined (HAVE_PCRE2_H) # include <pcre2.h> # elif defined (HAVE_PCRE2_PCRE2_H) # include <pcre2/pcre2.h> # endif #elif defined (HAVE_PCRE) # if defined (HAVE_PCRE_H) # include <pcre.h> # elif defined (HAVE_PCRE_PCRE_H) # include <pcre/pcre.h> # endif #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" #include "unistr-wrappers.h" #include "unwind-prot.h" #if defined (HAVE_PCRE2) typedef pcre2_code octave_pcre_code; typedef PCRE2_SIZE OCTAVE_PCRE_SIZE; void (*octave_pcre_code_free) (octave_pcre_code *) = pcre2_code_free; # define OCTAVE_PCRE_CASELESS PCRE2_CASELESS # define OCTAVE_PCRE_DOTALL PCRE2_DOTALL # define OCTAVE_PCRE_MULTILINE PCRE2_MULTILINE # define OCTAVE_PCRE_EXTENDED PCRE2_EXTENDED # define OCTAVE_PCRE_UTF PCRE2_UTF # define OCTAVE_PCRE_INFO_CAPTURECOUNT PCRE2_INFO_CAPTURECOUNT # define OCTAVE_PCRE_INFO_NAMECOUNT PCRE2_INFO_NAMECOUNT # define OCTAVE_PCRE_INFO_NAMEENTRYSIZE PCRE2_INFO_NAMEENTRYSIZE # define OCTAVE_PCRE_INFO_NAMETABLE PCRE2_INFO_NAMETABLE #elif defined (HAVE_PCRE) typedef pcre octave_pcre_code; typedef int OCTAVE_PCRE_SIZE; void (*octave_pcre_code_free) (void *) = pcre_free; # define OCTAVE_PCRE_CASELESS PCRE_CASELESS # define OCTAVE_PCRE_DOTALL PCRE_DOTALL # define OCTAVE_PCRE_MULTILINE PCRE_MULTILINE # define OCTAVE_PCRE_EXTENDED PCRE_EXTENDED # define OCTAVE_PCRE_UTF PCRE_UTF8 # define OCTAVE_PCRE_INFO_CAPTURECOUNT PCRE_INFO_CAPTURECOUNT # define OCTAVE_PCRE_INFO_NAMECOUNT PCRE_INFO_NAMECOUNT # define OCTAVE_PCRE_INFO_NAMEENTRYSIZE PCRE_INFO_NAMEENTRYSIZE # define OCTAVE_PCRE_INFO_NAMETABLE PCRE_INFO_NAMETABLE #else # error "PCRE2 or PCRE library is required to build Octave" #endif static inline int octave_pcre_pattern_info (const octave_pcre_code *code, int what, void *where) { #if defined (HAVE_PCRE2) return pcre2_pattern_info (code, what, where); #else return pcre_fullinfo (code, nullptr, what, where); #endif } OCTAVE_BEGIN_NAMESPACE(octave) // 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 () { octave_pcre_code_free (static_cast<octave_pcre_code *> (m_code)); } void regexp::compile_internal () { // If we had a previously compiled pattern, release it. free (); std::size_t max_length = MAXLOOKBEHIND; std::size_t pos = 0; std::size_t new_pos; int inames = 0; std::ostringstream buf; while ((new_pos = m_pattern.find ("(?", pos)) != std::string::npos) { std::size_t tmp_pos; if (m_pattern.size () > new_pos + 2 && m_pattern.at (new_pos + 2) == '<' && ! (m_pattern.size () > new_pos + 3 && (m_pattern.at (new_pos + 3) == '=' || m_pattern.at (new_pos + 3) == '!')) && (tmp_pos = m_pattern.find_first_of ('>', new_pos)) != std::string::npos && m_pattern.find_first_of (')', tmp_pos) != std::string::npos) { // 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. std::string tmp_name = m_pattern.substr (new_pos+3, tmp_pos-new_pos-3); bool found = false; for (int i = 0; i < m_names; i++) { if (m_named_pats(i) == tmp_name) { m_named_idx.resize (dim_vector (inames+1, 1)); m_named_idx(inames) = i; found = true; break; } } if (! found) { m_named_idx.resize (dim_vector (inames+1, 1)); m_named_idx(inames) = m_names; m_named_pats.append (tmp_name); m_names++; } if (new_pos - pos > 0) buf << m_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 (m_pattern.size () > new_pos + 2 && m_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; std::size_t tmp_pos1 = new_pos + 2; std::size_t tmp_pos2 = tmp_pos1; while (tmp_pos1 < m_pattern.length () && brackets > 0) { char ch = m_pattern.at (tmp_pos1); if (ch == '(') brackets++; else if (ch == ')') { if (brackets > 1) tmp_pos2 = tmp_pos1; brackets--; } tmp_pos1++; } if (brackets != 0) { buf << m_pattern.substr (pos, new_pos - pos) << "(?"; pos = new_pos + 2; } else { std::size_t tmp_pos3 = m_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_with_id_handler) ("Octave:regexp-lookbehind-limit", "%s: arbitrary length lookbehind patterns are only supported up to length %d", m_who.c_str (), MAXLOOKBEHIND); } buf << m_pattern.substr (pos, new_pos - pos) << '('; std::size_t i; if (m_pattern.at (tmp_pos3) == '*') i = 0; else i = 1; for (; i < max_length + 1; i++) { buf << m_pattern.substr (new_pos, tmp_pos3 - new_pos) << '{' << i << '}'; buf << m_pattern.substr (tmp_pos3 + 1, tmp_pos1 - tmp_pos3 - 1); if (i != max_length) buf << '|'; } buf << ')'; } else buf << m_pattern.substr (pos, tmp_pos1 - pos); pos = tmp_pos1; } } else { buf << m_pattern.substr (pos, new_pos - pos) << "(?"; pos = new_pos + 2; } } buf << m_pattern.substr (pos); // Replace NULLs with escape sequence because conversion function c_str() // will terminate string early at embedded NULLs. std::string buf_str = buf.str (); while ((pos = buf_str.find ('\0')) != std::string::npos) buf_str.replace (pos, 1, "\\000"); int pcre_options = ( (m_options.case_insensitive () ? OCTAVE_PCRE_CASELESS : 0) | (m_options.dotexceptnewline () ? 0 : OCTAVE_PCRE_DOTALL) | (m_options.lineanchors () ? OCTAVE_PCRE_MULTILINE : 0) | (m_options.freespacing () ? OCTAVE_PCRE_EXTENDED : 0) | OCTAVE_PCRE_UTF); #if defined (HAVE_PCRE2) PCRE2_SIZE erroffset; int errnumber; m_code = pcre2_compile (reinterpret_cast<PCRE2_SPTR> (buf_str.c_str ()), PCRE2_ZERO_TERMINATED, pcre_options, &errnumber, &erroffset, nullptr); if (! m_code) { // PCRE docs say: // // If the buffer is too small, the message is truncated (but // still with a trailing zero), and the negative error code // PCRE2_ERROR_NOMEMORY is returned. None of the messages are // very long; a buffer size of 120 code units is ample. // // so we assume that 256 will be large enough to avoid truncated // messages. PCRE2_UCHAR err [256]; pcre2_get_error_message (errnumber, err, sizeof (err)); (*current_liboctave_error_handler) ("%s: %s at position %zu of expression", m_who.c_str (), err, erroffset); } #else const char *err; int erroffset; m_code = pcre_compile (buf_str.c_str (), pcre_options, &err, &erroffset, nullptr); if (! m_code) (*current_liboctave_error_handler) ("%s: %s at position %d of expression", m_who.c_str (), err, erroffset); #endif } regexp::match_data regexp::match (const std::string& buffer) const { // check if input is valid utf-8 const uint8_t *buf_str = reinterpret_cast<const uint8_t *> (buffer.c_str ()); if (octave_u8_check_wrapper (buf_str, buffer.length ())) (*current_liboctave_error_handler) ("%s: the input string is invalid UTF-8", m_who.c_str ()); regexp::match_data retval; std::list<regexp::match_element> lst; int subpatterns; int namecount; int nameentrysize; char *nametable; std::size_t idx = 0; octave_pcre_code *re = static_cast<octave_pcre_code *> (m_code); octave_pcre_pattern_info (re, OCTAVE_PCRE_INFO_CAPTURECOUNT, &subpatterns); octave_pcre_pattern_info (re, OCTAVE_PCRE_INFO_NAMECOUNT, &namecount); octave_pcre_pattern_info (re, OCTAVE_PCRE_INFO_NAMEENTRYSIZE, &nameentrysize); octave_pcre_pattern_info (re, OCTAVE_PCRE_INFO_NAMETABLE, &nametable); #if defined (HAVE_PCRE) OCTAVE_LOCAL_BUFFER (OCTAVE_PCRE_SIZE, ovector, (subpatterns+1)*3); #endif OCTAVE_LOCAL_BUFFER (int, nidx, namecount); for (int i = 0; i < namecount; i++) { // Index of subpattern in first two bytes of name (MSB first). // Extract index. nidx[i] = (static_cast<int> (nametable[i*nameentrysize])) << 8 | static_cast<int> (nametable[i*nameentrysize+1]); } while (true) { octave_quit (); #if defined (HAVE_PCRE2) pcre2_match_data *m_data = pcre2_match_data_create_from_pattern (re, nullptr); unwind_action cleanup_match_data ([=] () { pcre2_match_data_free (m_data); }); int matches = pcre2_match (re, reinterpret_cast<PCRE2_SPTR> (buffer.c_str ()), buffer.length (), idx, PCRE2_NO_UTF_CHECK | (idx ? PCRE2_NOTBOL : 0), m_data, nullptr); if (matches < 0 && matches != PCRE2_ERROR_NOMATCH) (*current_liboctave_error_handler) ("%s: internal error calling pcre2_match; " "error code from pcre2_match is %i", m_who.c_str (), matches); if (matches == PCRE2_ERROR_NOMATCH) break; OCTAVE_PCRE_SIZE *ovector = pcre2_get_ovector_pointer (m_data); #else int matches = pcre_exec (re, nullptr, buffer.c_str (), buffer.length (), idx, PCRE_NO_UTF8_CHECK | (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_with_id_handler) ("Octave:regexp-match-limit", "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, PCRE_NO_UTF8_CHECK | (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", m_who.c_str (), matches); if (matches == PCRE_ERROR_NOMATCH) break; #endif if (ovector[0] >= ovector[1] && ! m_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 defined (HAVE_PCRE2) if (ovector[2*i] != PCRE2_SIZE_MAX #else if (ovector[2*i] >= 0 #endif && 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); OCTAVE_PCRE_SIZE start = ovector[0] + 1; OCTAVE_PCRE_SIZE end = ovector[1]; #if defined (HAVE_PCRE2) // Must use explicit length constructor as match can contain '\0'. std::string match_string = std::string (buffer.c_str() + start - 1, end - start + 1); #else 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", m_who.c_str ()); // Must use explicit length constructor as match can contain '\0'. std::string match_string = std::string (*listptr, end - start + 1); #endif string_vector tokens (pos_match); string_vector named_tokens (m_names); #if ! defined (HAVE_PCRE2) int pos_offset = 0; #endif pos_match = 0; for (int i = 1; i < matches; i++) { #if defined (HAVE_PCRE2) if (ovector[2*i] != PCRE2_SIZE_MAX #else if (ovector[2*i] >= 0 #endif && 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) { std::size_t len = ovector[2*i+1] - ovector[2*i]; named_tokens(m_named_idx(j)) #if defined (HAVE_PCRE2) = std::string (buffer.c_str () + ovector[2*i], len); #else = std::string (*(listptr+i-pos_offset), len); #endif break; } } } std::size_t len = ovector[2*i+1] - ovector[2*i]; #if defined (HAVE_PCRE2) tokens(pos_match++) = std::string (buffer.c_str() + ovector[2*i], len); #else tokens(pos_match++) = std::string (*(listptr+i), len); #endif } #if ! defined (HAVE_PCRE2) else pos_offset++; #endif } } #if ! defined (HAVE_PCRE2) pcre_free_substring_list (listptr); #endif // FIXME: MATCH_ELEMENT uses double values for these, // presumably because that is what the Octave interpreter // uses. Should we check that the values don't exceed // flintmax here? It seems unlikely that it would happen, // but... double dstart = static_cast<double> (start); double dend = static_cast<double> (end); regexp::match_element new_elem (named_tokens, tokens, match_string, token_extents, dstart, dend); 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 (m_options.once () || idx >= buffer.length ()) break; } } retval = regexp::match_data (lst, m_named_pats); return retval; } bool regexp::is_match (const std::string& buffer) const { regexp::match_data rx_lst = match (buffer); return rx_lst.size () > 0; } Array<bool> regexp::is_match (const string_vector& buffer) const { octave_idx_type len = buffer.numel (); Array<bool> retval (dim_vector (len, 1)); for (octave_idx_type i = 0; i < buffer.numel (); i++) retval(i) = is_match (buffer(i)); return retval; } // Declare rep_token_t used in processing replacement string struct rep_token_t { std::size_t pos; int num; }; std::string regexp::replace (const std::string& buffer, const std::string& replacement) const { std::string retval; const regexp::match_data rx_lst = match (buffer); std::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 $1 followed by the character '1' rather than // the eleventh capture buffer. std::string repstr = replacement; std::vector<rep_token_t> tokens; tokens.reserve (5); // Reserve memory for 5 pattern replacements for (std::size_t i=0; i < repstr.size (); i++) { if (repstr[i] == '\\') { if (i < repstr.size () - 1 && repstr[i+1] == '$') { 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 std::size_t replen = repstr.size () - 2*num_tokens; int delta = 0; auto p = rx_lst.begin (); for (std::size_t i = 0; i < num_matches; i++) { octave_quit (); double start = p->start (); double end = p->end (); const Matrix pairs (p->token_extents ()); std::size_t pairlen = 0; for (int j = 0; j < num_tokens; j++) { if (tokens[j].num == 0) pairlen += static_cast<std::size_t> (end - start + 1); else if (tokens[j].num <= pairs.rows ()) pairlen += static_cast<std::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); std::size_t from = 0; p = rx_lst.begin (); for (std::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<std::size_t> (start - 1 - from)); from = static_cast<std::size_t> (end); std::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<std::size_t> (end - 1)], static_cast<std::size_t> (end - start + 1)); } else if (k <= pairs.rows ()) { // replace with group capture rep.append (&buffer[static_cast<std::size_t> (pairs(k-1, 0)-1)], static_cast<std::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 std::size_t replen = repstr.size (); int delta = 0; auto p = rx_lst.begin (); for (std::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); std::size_t from = 0; p = rx_lst.begin (); for (std::size_t i = 0; i < num_matches; i++) { octave_quit (); rep.append (&buffer[from], static_cast<std::size_t> (p->start () - 1 - from)); from = static_cast<std::size_t> (p->end ()); rep.append (repstr); p++; } rep.append (&buffer[from], buffer.size () - from); } retval = rep; return retval; } OCTAVE_END_NAMESPACE(octave)