| // Copyright 2003-2009 The RE2 Authors. All Rights Reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // Regular expression interface RE2. |
| // |
| // Originally the PCRE C++ wrapper, but adapted to use |
| // the new automata-based regular expression engines. |
| |
| #include "re2/re2.h" |
| |
| #include <stdio.h> |
| #include <string> |
| #include <pthread.h> |
| #include <errno.h> |
| #include "util/util.h" |
| #include "util/flags.h" |
| #include "re2/prog.h" |
| #include "re2/regexp.h" |
| |
| DEFINE_bool(trace_re2, false, "trace RE2 execution"); |
| |
| namespace re2 { |
| |
| // Maximum number of args we can set |
| static const int kMaxArgs = 16; |
| static const int kVecSize = 1+kMaxArgs; |
| |
| const VariadicFunction2<bool, const StringPiece&, const RE2&, RE2::Arg, RE2::FullMatchN> RE2::FullMatch; |
| const VariadicFunction2<bool, const StringPiece&, const RE2&, RE2::Arg, RE2::PartialMatchN> RE2::PartialMatch; |
| const VariadicFunction2<bool, StringPiece*, const RE2&, RE2::Arg, RE2::ConsumeN> RE2::Consume; |
| const VariadicFunction2<bool, StringPiece*, const RE2&, RE2::Arg, RE2::FindAndConsumeN> RE2::FindAndConsume; |
| |
| // This will trigger LNK2005 error in MSVC. |
| #ifndef COMPILER_MSVC |
| const int RE2::Options::kDefaultMaxMem; // initialized in re2.h |
| #endif // COMPILER_MSVC |
| |
| RE2::Options::Options(RE2::CannedOptions opt) |
| : encoding_(opt == RE2::Latin1 ? EncodingLatin1 : EncodingUTF8), |
| posix_syntax_(opt == RE2::POSIX), |
| longest_match_(opt == RE2::POSIX), |
| log_errors_(opt != RE2::Quiet), |
| max_mem_(kDefaultMaxMem), |
| literal_(false), |
| never_nl_(false), |
| never_capture_(false), |
| case_sensitive_(true), |
| perl_classes_(false), |
| word_boundary_(false), |
| one_line_(false) { |
| } |
| |
| // static empty things for use as const references. |
| // To avoid global constructors, initialized on demand. |
| GLOBAL_MUTEX(empty_mutex); |
| static const string *empty_string; |
| static const map<string, int> *empty_named_groups; |
| static const map<int, string> *empty_group_names; |
| |
| static void InitEmpty() { |
| GLOBAL_MUTEX_LOCK(empty_mutex); |
| if (empty_string == NULL) { |
| empty_string = new string; |
| empty_named_groups = new map<string, int>; |
| empty_group_names = new map<int, string>; |
| } |
| GLOBAL_MUTEX_UNLOCK(empty_mutex); |
| } |
| |
| // Converts from Regexp error code to RE2 error code. |
| // Maybe some day they will diverge. In any event, this |
| // hides the existence of Regexp from RE2 users. |
| static RE2::ErrorCode RegexpErrorToRE2(re2::RegexpStatusCode code) { |
| switch (code) { |
| case re2::kRegexpSuccess: |
| return RE2::NoError; |
| case re2::kRegexpInternalError: |
| return RE2::ErrorInternal; |
| case re2::kRegexpBadEscape: |
| return RE2::ErrorBadEscape; |
| case re2::kRegexpBadCharClass: |
| return RE2::ErrorBadCharClass; |
| case re2::kRegexpBadCharRange: |
| return RE2::ErrorBadCharRange; |
| case re2::kRegexpMissingBracket: |
| return RE2::ErrorMissingBracket; |
| case re2::kRegexpMissingParen: |
| return RE2::ErrorMissingParen; |
| case re2::kRegexpTrailingBackslash: |
| return RE2::ErrorTrailingBackslash; |
| case re2::kRegexpRepeatArgument: |
| return RE2::ErrorRepeatArgument; |
| case re2::kRegexpRepeatSize: |
| return RE2::ErrorRepeatSize; |
| case re2::kRegexpRepeatOp: |
| return RE2::ErrorRepeatOp; |
| case re2::kRegexpBadPerlOp: |
| return RE2::ErrorBadPerlOp; |
| case re2::kRegexpBadUTF8: |
| return RE2::ErrorBadUTF8; |
| case re2::kRegexpBadNamedCapture: |
| return RE2::ErrorBadNamedCapture; |
| } |
| return RE2::ErrorInternal; |
| } |
| |
| static string trunc(const StringPiece& pattern) { |
| if (pattern.size() < 100) |
| return pattern.as_string(); |
| return pattern.substr(0, 100).as_string() + "..."; |
| } |
| |
| |
| RE2::RE2(const char* pattern) { |
| Init(pattern, DefaultOptions); |
| } |
| |
| RE2::RE2(const string& pattern) { |
| Init(pattern, DefaultOptions); |
| } |
| |
| RE2::RE2(const StringPiece& pattern) { |
| Init(pattern, DefaultOptions); |
| } |
| |
| RE2::RE2(const StringPiece& pattern, const Options& options) { |
| Init(pattern, options); |
| } |
| |
| int RE2::Options::ParseFlags() const { |
| int flags = Regexp::ClassNL; |
| switch (encoding()) { |
| default: |
| if (log_errors()) |
| LOG(ERROR) << "Unknown encoding " << encoding(); |
| break; |
| case RE2::Options::EncodingUTF8: |
| break; |
| case RE2::Options::EncodingLatin1: |
| flags |= Regexp::Latin1; |
| break; |
| } |
| |
| if (!posix_syntax()) |
| flags |= Regexp::LikePerl; |
| |
| if (literal()) |
| flags |= Regexp::Literal; |
| |
| if (never_nl()) |
| flags |= Regexp::NeverNL; |
| |
| if (never_capture()) |
| flags |= Regexp::NeverCapture; |
| |
| if (!case_sensitive()) |
| flags |= Regexp::FoldCase; |
| |
| if (perl_classes()) |
| flags |= Regexp::PerlClasses; |
| |
| if (word_boundary()) |
| flags |= Regexp::PerlB; |
| |
| if (one_line()) |
| flags |= Regexp::OneLine; |
| |
| return flags; |
| } |
| |
| void RE2::Init(const StringPiece& pattern, const Options& options) { |
| mutex_ = new Mutex; |
| pattern_ = pattern.as_string(); |
| options_.Copy(options); |
| InitEmpty(); |
| error_ = empty_string; |
| error_code_ = NoError; |
| suffix_regexp_ = NULL; |
| entire_regexp_ = NULL; |
| prog_ = NULL; |
| rprog_ = NULL; |
| named_groups_ = NULL; |
| group_names_ = NULL; |
| num_captures_ = -1; |
| |
| RegexpStatus status; |
| entire_regexp_ = Regexp::Parse( |
| pattern_, |
| static_cast<Regexp::ParseFlags>(options_.ParseFlags()), |
| &status); |
| if (entire_regexp_ == NULL) { |
| if (error_ == empty_string) |
| error_ = new string(status.Text()); |
| if (options_.log_errors()) { |
| LOG(ERROR) << "Error parsing '" << trunc(pattern_) << "': " |
| << status.Text(); |
| } |
| error_arg_ = status.error_arg().as_string(); |
| error_code_ = RegexpErrorToRE2(status.code()); |
| return; |
| } |
| |
| prefix_.clear(); |
| prefix_foldcase_ = false; |
| re2::Regexp* suffix; |
| if (entire_regexp_->RequiredPrefix(&prefix_, &prefix_foldcase_, &suffix)) |
| suffix_regexp_ = suffix; |
| else |
| suffix_regexp_ = entire_regexp_->Incref(); |
| |
| // Two thirds of the memory goes to the forward Prog, |
| // one third to the reverse prog, because the forward |
| // Prog has two DFAs but the reverse prog has one. |
| prog_ = suffix_regexp_->CompileToProg(options_.max_mem()*2/3); |
| if (prog_ == NULL) { |
| if (options_.log_errors()) |
| LOG(ERROR) << "Error compiling '" << trunc(pattern_) << "'"; |
| error_ = new string("pattern too large - compile failed"); |
| error_code_ = RE2::ErrorPatternTooLarge; |
| return; |
| } |
| |
| // Could delay this until the first match call that |
| // cares about submatch information, but the one-pass |
| // machine's memory gets cut from the DFA memory budget, |
| // and that is harder to do if the DFA has already |
| // been built. |
| is_one_pass_ = prog_->IsOnePass(); |
| } |
| |
| // Returns rprog_, computing it if needed. |
| re2::Prog* RE2::ReverseProg() const { |
| MutexLock l(mutex_); |
| if (rprog_ == NULL && error_ == empty_string) { |
| rprog_ = suffix_regexp_->CompileToReverseProg(options_.max_mem()/3); |
| if (rprog_ == NULL) { |
| if (options_.log_errors()) |
| LOG(ERROR) << "Error reverse compiling '" << trunc(pattern_) << "'"; |
| error_ = new string("pattern too large - reverse compile failed"); |
| error_code_ = RE2::ErrorPatternTooLarge; |
| return NULL; |
| } |
| } |
| return rprog_; |
| } |
| |
| RE2::~RE2() { |
| if (suffix_regexp_) |
| suffix_regexp_->Decref(); |
| if (entire_regexp_) |
| entire_regexp_->Decref(); |
| delete mutex_; |
| delete prog_; |
| delete rprog_; |
| if (error_ != empty_string) |
| delete error_; |
| if (named_groups_ != NULL && named_groups_ != empty_named_groups) |
| delete named_groups_; |
| if (group_names_ != NULL && group_names_ != empty_group_names) |
| delete group_names_; |
| } |
| |
| int RE2::ProgramSize() const { |
| if (prog_ == NULL) |
| return -1; |
| return prog_->size(); |
| } |
| |
| // Returns named_groups_, computing it if needed. |
| const map<string, int>& RE2::NamedCapturingGroups() const { |
| MutexLock l(mutex_); |
| if (!ok()) |
| return *empty_named_groups; |
| if (named_groups_ == NULL) { |
| named_groups_ = suffix_regexp_->NamedCaptures(); |
| if (named_groups_ == NULL) |
| named_groups_ = empty_named_groups; |
| } |
| return *named_groups_; |
| } |
| |
| // Returns group_names_, computing it if needed. |
| const map<int, string>& RE2::CapturingGroupNames() const { |
| MutexLock l(mutex_); |
| if (!ok()) |
| return *empty_group_names; |
| if (group_names_ == NULL) { |
| group_names_ = suffix_regexp_->CaptureNames(); |
| if (group_names_ == NULL) |
| group_names_ = empty_group_names; |
| } |
| return *group_names_; |
| } |
| |
| /***** Convenience interfaces *****/ |
| |
| bool RE2::FullMatchN(const StringPiece& text, const RE2& re, |
| const Arg* const args[], int n) { |
| return re.DoMatch(text, ANCHOR_BOTH, NULL, args, n); |
| } |
| |
| bool RE2::PartialMatchN(const StringPiece& text, const RE2& re, |
| const Arg* const args[], int n) { |
| return re.DoMatch(text, UNANCHORED, NULL, args, n); |
| } |
| |
| bool RE2::ConsumeN(StringPiece* input, const RE2& re, |
| const Arg* const args[], int n) { |
| int consumed; |
| if (re.DoMatch(*input, ANCHOR_START, &consumed, args, n)) { |
| input->remove_prefix(consumed); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| bool RE2::FindAndConsumeN(StringPiece* input, const RE2& re, |
| const Arg* const args[], int n) { |
| int consumed; |
| if (re.DoMatch(*input, UNANCHORED, &consumed, args, n)) { |
| input->remove_prefix(consumed); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| // Returns the maximum submatch needed for the rewrite to be done by Replace(). |
| // E.g. if rewrite == "foo \\2,\\1", returns 2. |
| int RE2::MaxSubmatch(const StringPiece& rewrite) { |
| int max = 0; |
| for (const char *s = rewrite.data(), *end = s + rewrite.size(); |
| s < end; s++) { |
| if (*s == '\\') { |
| s++; |
| int c = (s < end) ? *s : -1; |
| if (isdigit(c)) { |
| int n = (c - '0'); |
| if (n > max) |
| max = n; |
| } |
| } |
| } |
| return max; |
| } |
| |
| bool RE2::Replace(string *str, |
| const RE2& re, |
| const StringPiece& rewrite) { |
| StringPiece vec[kVecSize]; |
| int nvec = 1 + MaxSubmatch(rewrite); |
| if (nvec > arraysize(vec)) |
| return false; |
| if (!re.Match(*str, 0, str->size(), UNANCHORED, vec, nvec)) |
| return false; |
| |
| string s; |
| if (!re.Rewrite(&s, rewrite, vec, nvec)) |
| return false; |
| |
| assert(vec[0].begin() >= str->data()); |
| assert(vec[0].end() <= str->data()+str->size()); |
| str->replace(vec[0].data() - str->data(), vec[0].size(), s); |
| return true; |
| } |
| |
| int RE2::GlobalReplace(string *str, |
| const RE2& re, |
| const StringPiece& rewrite) { |
| StringPiece vec[kVecSize]; |
| int nvec = 1 + MaxSubmatch(rewrite); |
| if (nvec > arraysize(vec)) |
| return false; |
| |
| const char* p = str->data(); |
| const char* ep = p + str->size(); |
| const char* lastend = NULL; |
| string out; |
| int count = 0; |
| while (p <= ep) { |
| if (!re.Match(*str, p - str->data(), str->size(), UNANCHORED, vec, nvec)) |
| break; |
| if (p < vec[0].begin()) |
| out.append(p, vec[0].begin() - p); |
| if (vec[0].begin() == lastend && vec[0].size() == 0) { |
| // Disallow empty match at end of last match: skip ahead. |
| if (p < ep) |
| out.append(p, 1); |
| p++; |
| continue; |
| } |
| re.Rewrite(&out, rewrite, vec, nvec); |
| p = vec[0].end(); |
| lastend = p; |
| count++; |
| } |
| |
| if (count == 0) |
| return 0; |
| |
| if (p < ep) |
| out.append(p, ep - p); |
| swap(out, *str); |
| return count; |
| } |
| |
| bool RE2::Extract(const StringPiece &text, |
| const RE2& re, |
| const StringPiece &rewrite, |
| string *out) { |
| StringPiece vec[kVecSize]; |
| int nvec = 1 + MaxSubmatch(rewrite); |
| if (nvec > arraysize(vec)) |
| return false; |
| |
| if (!re.Match(text, 0, text.size(), UNANCHORED, vec, nvec)) |
| return false; |
| |
| out->clear(); |
| return re.Rewrite(out, rewrite, vec, nvec); |
| } |
| |
| string RE2::QuoteMeta(const StringPiece& unquoted) { |
| string result; |
| result.reserve(unquoted.size() << 1); |
| |
| // Escape any ascii character not in [A-Za-z_0-9]. |
| // |
| // Note that it's legal to escape a character even if it has no |
| // special meaning in a regular expression -- so this function does |
| // that. (This also makes it identical to the perl function of the |
| // same name except for the null-character special case; |
| // see `perldoc -f quotemeta`.) |
| for (int ii = 0; ii < unquoted.length(); ++ii) { |
| // Note that using 'isalnum' here raises the benchmark time from |
| // 32ns to 58ns: |
| if ((unquoted[ii] < 'a' || unquoted[ii] > 'z') && |
| (unquoted[ii] < 'A' || unquoted[ii] > 'Z') && |
| (unquoted[ii] < '0' || unquoted[ii] > '9') && |
| unquoted[ii] != '_' && |
| // If this is the part of a UTF8 or Latin1 character, we need |
| // to copy this byte without escaping. Experimentally this is |
| // what works correctly with the regexp library. |
| !(unquoted[ii] & 128)) { |
| if (unquoted[ii] == '\0') { // Special handling for null chars. |
| // Note that this special handling is not strictly required for RE2, |
| // but this quoting is required for other regexp libraries such as |
| // PCRE. |
| // Can't use "\\0" since the next character might be a digit. |
| result += "\\x00"; |
| continue; |
| } |
| result += '\\'; |
| } |
| result += unquoted[ii]; |
| } |
| |
| return result; |
| } |
| |
| bool RE2::PossibleMatchRange(string* min, string* max, int maxlen) const { |
| if (prog_ == NULL) |
| return false; |
| |
| int n = prefix_.size(); |
| if (n > maxlen) |
| n = maxlen; |
| |
| // Determine initial min max from prefix_ literal. |
| string pmin, pmax; |
| pmin = prefix_.substr(0, n); |
| pmax = prefix_.substr(0, n); |
| if (prefix_foldcase_) { |
| // prefix is ASCII lowercase; change pmin to uppercase. |
| for (int i = 0; i < n; i++) { |
| if ('a' <= pmin[i] && pmin[i] <= 'z') |
| pmin[i] += 'A' - 'a'; |
| } |
| } |
| |
| // Add to prefix min max using PossibleMatchRange on regexp. |
| string dmin, dmax; |
| maxlen -= n; |
| if (maxlen > 0 && prog_->PossibleMatchRange(&dmin, &dmax, maxlen)) { |
| pmin += dmin; |
| pmax += dmax; |
| } else if (pmax.size() > 0) { |
| // prog_->PossibleMatchRange has failed us, |
| // but we still have useful information from prefix_. |
| // Round up pmax to allow any possible suffix. |
| pmax = PrefixSuccessor(pmax); |
| } else { |
| // Nothing useful. |
| *min = ""; |
| *max = ""; |
| return false; |
| } |
| |
| *min = pmin; |
| *max = pmax; |
| return true; |
| } |
| |
| // Avoid possible locale nonsense in standard strcasecmp. |
| // The string a is known to be all lowercase. |
| static int ascii_strcasecmp(const char* a, const char* b, int len) { |
| const char *ae = a + len; |
| |
| for (; a < ae; a++, b++) { |
| uint8 x = *a; |
| uint8 y = *b; |
| if ('A' <= y && y <= 'Z') |
| y += 'a' - 'A'; |
| if (x != y) |
| return x - y; |
| } |
| return 0; |
| } |
| |
| |
| /***** Actual matching and rewriting code *****/ |
| |
| bool RE2::Match(const StringPiece& text, |
| int startpos, |
| int endpos, |
| Anchor re_anchor, |
| StringPiece* submatch, |
| int nsubmatch) const { |
| if (!ok() || suffix_regexp_ == NULL) { |
| if (options_.log_errors()) |
| LOG(ERROR) << "Invalid RE2: " << *error_; |
| return false; |
| } |
| |
| if (startpos < 0 || startpos > endpos || endpos > text.size()) { |
| if (options_.log_errors()) |
| LOG(ERROR) << "RE2: invalid startpos, endpos pair."; |
| return false; |
| } |
| |
| StringPiece subtext = text; |
| subtext.remove_prefix(startpos); |
| subtext.remove_suffix(text.size() - endpos); |
| |
| // Use DFAs to find exact location of match, filter out non-matches. |
| |
| // Don't ask for the location if we won't use it. |
| // SearchDFA can do extra optimizations in that case. |
| StringPiece match; |
| StringPiece* matchp = &match; |
| if (nsubmatch == 0) |
| matchp = NULL; |
| |
| int ncap = 1 + NumberOfCapturingGroups(); |
| if (ncap > nsubmatch) |
| ncap = nsubmatch; |
| |
| // If the regexp is anchored explicitly, must not be in middle of text. |
| if (prog_->anchor_start() && startpos != 0) |
| return false; |
| |
| // If the regexp is anchored explicitly, update re_anchor |
| // so that we can potentially fall into a faster case below. |
| if (prog_->anchor_start() && prog_->anchor_end()) |
| re_anchor = ANCHOR_BOTH; |
| else if (prog_->anchor_start() && re_anchor != ANCHOR_BOTH) |
| re_anchor = ANCHOR_START; |
| |
| // Check for the required prefix, if any. |
| int prefixlen = 0; |
| if (!prefix_.empty()) { |
| if (startpos != 0) |
| return false; |
| prefixlen = prefix_.size(); |
| if (prefixlen > subtext.size()) |
| return false; |
| if (prefix_foldcase_) { |
| if (ascii_strcasecmp(&prefix_[0], subtext.data(), prefixlen) != 0) |
| return false; |
| } else { |
| if (memcmp(&prefix_[0], subtext.data(), prefixlen) != 0) |
| return false; |
| } |
| subtext.remove_prefix(prefixlen); |
| // If there is a required prefix, the anchor must be at least ANCHOR_START. |
| if (re_anchor != ANCHOR_BOTH) |
| re_anchor = ANCHOR_START; |
| } |
| |
| Prog::Anchor anchor = Prog::kUnanchored; |
| Prog::MatchKind kind = Prog::kFirstMatch; |
| if (options_.longest_match()) |
| kind = Prog::kLongestMatch; |
| bool skipped_test = false; |
| |
| bool can_one_pass = (is_one_pass_ && ncap <= Prog::kMaxOnePassCapture); |
| |
| // SearchBitState allocates a bit vector of size prog_->size() * text.size(). |
| // It also allocates a stack of 3-word structures which could potentially |
| // grow as large as prog_->size() * text.size() but in practice is much |
| // smaller. |
| // Conditions for using SearchBitState: |
| const int MaxBitStateProg = 500; // prog_->size() <= Max. |
| const int MaxBitStateVector = 256*1024; // bit vector size <= Max (bits) |
| bool can_bit_state = prog_->size() <= MaxBitStateProg; |
| int bit_state_text_max = MaxBitStateVector / prog_->size(); |
| |
| bool dfa_failed = false; |
| switch (re_anchor) { |
| default: |
| case UNANCHORED: { |
| if (!prog_->SearchDFA(subtext, text, anchor, kind, |
| matchp, &dfa_failed, NULL)) { |
| if (dfa_failed) { |
| // Fall back to NFA below. |
| skipped_test = true; |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " DFA failed."; |
| break; |
| } |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " used DFA - no match."; |
| return false; |
| } |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " used DFA - match"; |
| if (matchp == NULL) // Matched. Don't care where |
| return true; |
| // SearchDFA set match[0].end() but didn't know where the |
| // match started. Run the regexp backward from match[0].end() |
| // to find the longest possible match -- that's where it started. |
| Prog* prog = ReverseProg(); |
| if (prog == NULL) |
| return false; |
| if (!prog->SearchDFA(match, text, Prog::kAnchored, |
| Prog::kLongestMatch, &match, &dfa_failed, NULL)) { |
| if (dfa_failed) { |
| // Fall back to NFA below. |
| skipped_test = true; |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " reverse DFA failed."; |
| break; |
| } |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " DFA inconsistency."; |
| if (options_.log_errors()) |
| LOG(ERROR) << "DFA inconsistency"; |
| return false; |
| } |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " used reverse DFA."; |
| break; |
| } |
| |
| case ANCHOR_BOTH: |
| case ANCHOR_START: |
| if (re_anchor == ANCHOR_BOTH) |
| kind = Prog::kFullMatch; |
| anchor = Prog::kAnchored; |
| |
| // If only a small amount of text and need submatch |
| // information anyway and we're going to use OnePass or BitState |
| // to get it, we might as well not even bother with the DFA: |
| // OnePass or BitState will be fast enough. |
| // On tiny texts, OnePass outruns even the DFA, and |
| // it doesn't have the shared state and occasional mutex that |
| // the DFA does. |
| if (can_one_pass && text.size() <= 4096 && |
| (ncap > 1 || text.size() <= 8)) { |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " skipping DFA for OnePass."; |
| skipped_test = true; |
| break; |
| } |
| if (can_bit_state && text.size() <= bit_state_text_max && ncap > 1) { |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " skipping DFA for BitState."; |
| skipped_test = true; |
| break; |
| } |
| if (!prog_->SearchDFA(subtext, text, anchor, kind, |
| &match, &dfa_failed, NULL)) { |
| if (dfa_failed) { |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " DFA failed."; |
| skipped_test = true; |
| break; |
| } |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " used DFA - no match."; |
| return false; |
| } |
| break; |
| } |
| |
| if (!skipped_test && ncap <= 1) { |
| // We know exactly where it matches. That's enough. |
| if (ncap == 1) |
| submatch[0] = match; |
| } else { |
| StringPiece subtext1; |
| if (skipped_test) { |
| // DFA ran out of memory or was skipped: |
| // need to search in entire original text. |
| subtext1 = subtext; |
| } else { |
| // DFA found the exact match location: |
| // let NFA run an anchored, full match search |
| // to find submatch locations. |
| subtext1 = match; |
| anchor = Prog::kAnchored; |
| kind = Prog::kFullMatch; |
| } |
| |
| if (can_one_pass && anchor != Prog::kUnanchored) { |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " using OnePass."; |
| if (!prog_->SearchOnePass(subtext1, text, anchor, kind, submatch, ncap)) { |
| if (!skipped_test && options_.log_errors()) |
| LOG(ERROR) << "SearchOnePass inconsistency"; |
| return false; |
| } |
| } else if (can_bit_state && subtext1.size() <= bit_state_text_max) { |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " using BitState."; |
| if (!prog_->SearchBitState(subtext1, text, anchor, |
| kind, submatch, ncap)) { |
| if (!skipped_test && options_.log_errors()) |
| LOG(ERROR) << "SearchBitState inconsistency"; |
| return false; |
| } |
| } else { |
| if (FLAGS_trace_re2) |
| LOG(INFO) << "Match " << trunc(pattern_) |
| << " [" << CEscape(subtext) << "]" |
| << " using NFA."; |
| if (!prog_->SearchNFA(subtext1, text, anchor, kind, submatch, ncap)) { |
| if (!skipped_test && options_.log_errors()) |
| LOG(ERROR) << "SearchNFA inconsistency"; |
| return false; |
| } |
| } |
| } |
| |
| // Adjust overall match for required prefix that we stripped off. |
| if (prefixlen > 0 && nsubmatch > 0) |
| submatch[0] = StringPiece(submatch[0].begin() - prefixlen, |
| submatch[0].size() + prefixlen); |
| |
| // Zero submatches that don't exist in the regexp. |
| for (int i = ncap; i < nsubmatch; i++) |
| submatch[i] = NULL; |
| return true; |
| } |
| |
| // Internal matcher - like Match() but takes Args not StringPieces. |
| bool RE2::DoMatch(const StringPiece& text, |
| Anchor anchor, |
| int* consumed, |
| const Arg* const* args, |
| int n) const { |
| if (!ok()) { |
| if (options_.log_errors()) |
| LOG(ERROR) << "Invalid RE2: " << *error_; |
| return false; |
| } |
| |
| // Count number of capture groups needed. |
| int nvec; |
| if (n == 0 && consumed == NULL) |
| nvec = 0; |
| else |
| nvec = n+1; |
| |
| StringPiece* vec; |
| StringPiece stkvec[kVecSize]; |
| StringPiece* heapvec = NULL; |
| |
| if (nvec <= arraysize(stkvec)) { |
| vec = stkvec; |
| } else { |
| vec = new StringPiece[nvec]; |
| heapvec = vec; |
| } |
| |
| if (!Match(text, 0, text.size(), anchor, vec, nvec)) { |
| delete[] heapvec; |
| return false; |
| } |
| |
| if(consumed != NULL) |
| *consumed = vec[0].end() - text.begin(); |
| |
| if (n == 0 || args == NULL) { |
| // We are not interested in results |
| delete[] heapvec; |
| return true; |
| } |
| |
| int ncap = NumberOfCapturingGroups(); |
| if (ncap < n) { |
| // RE has fewer capturing groups than number of arg pointers passed in |
| VLOG(1) << "Asked for " << n << " but only have " << ncap; |
| delete[] heapvec; |
| return false; |
| } |
| |
| // If we got here, we must have matched the whole pattern. |
| for (int i = 0; i < n; i++) { |
| const StringPiece& s = vec[i+1]; |
| if (!args[i]->Parse(s.data(), s.size())) { |
| // TODO: Should we indicate what the error was? |
| VLOG(1) << "Parse error on #" << i << " " << s << " " |
| << (void*)s.data() << "/" << s.size(); |
| delete[] heapvec; |
| return false; |
| } |
| } |
| |
| delete[] heapvec; |
| return true; |
| } |
| |
| // Append the "rewrite" string, with backslash subsitutions from "vec", |
| // to string "out". |
| bool RE2::Rewrite(string *out, const StringPiece &rewrite, |
| const StringPiece *vec, int veclen) const { |
| for (const char *s = rewrite.data(), *end = s + rewrite.size(); |
| s < end; s++) { |
| int c = *s; |
| if (c == '\\') { |
| s++; |
| c = (s < end) ? *s : -1; |
| if (isdigit(c)) { |
| int n = (c - '0'); |
| if (n >= veclen) { |
| if (options_.log_errors()) { |
| LOG(ERROR) << "requested group " << n |
| << " in regexp " << rewrite.data(); |
| } |
| return false; |
| } |
| StringPiece snip = vec[n]; |
| if (snip.size() > 0) |
| out->append(snip.data(), snip.size()); |
| } else if (c == '\\') { |
| out->push_back('\\'); |
| } else { |
| if (options_.log_errors()) |
| LOG(ERROR) << "invalid rewrite pattern: " << rewrite.data(); |
| return false; |
| } |
| } else { |
| out->push_back(c); |
| } |
| } |
| return true; |
| } |
| |
| // Return the number of capturing subpatterns, or -1 if the |
| // regexp wasn't valid on construction. |
| int RE2::NumberOfCapturingGroups() const { |
| if (suffix_regexp_ == NULL) |
| return -1; |
| ANNOTATE_BENIGN_RACE(&num_captures_, "benign race: in the worst case" |
| " multiple threads end up doing the same work in parallel."); |
| if (num_captures_ == -1) |
| num_captures_ = suffix_regexp_->NumCaptures(); |
| return num_captures_; |
| } |
| |
| // Checks that the rewrite string is well-formed with respect to this |
| // regular expression. |
| bool RE2::CheckRewriteString(const StringPiece& rewrite, string* error) const { |
| int max_token = -1; |
| for (const char *s = rewrite.data(), *end = s + rewrite.size(); |
| s < end; s++) { |
| int c = *s; |
| if (c != '\\') { |
| continue; |
| } |
| if (++s == end) { |
| *error = "Rewrite schema error: '\\' not allowed at end."; |
| return false; |
| } |
| c = *s; |
| if (c == '\\') { |
| continue; |
| } |
| if (!isdigit(c)) { |
| *error = "Rewrite schema error: " |
| "'\\' must be followed by a digit or '\\'."; |
| return false; |
| } |
| int n = (c - '0'); |
| if (max_token < n) { |
| max_token = n; |
| } |
| } |
| |
| if (max_token > NumberOfCapturingGroups()) { |
| SStringPrintf(error, "Rewrite schema requests %d matches, " |
| "but the regexp only has %d parenthesized subexpressions.", |
| max_token, NumberOfCapturingGroups()); |
| return false; |
| } |
| return true; |
| } |
| |
| /***** Parsers for various types *****/ |
| |
| bool RE2::Arg::parse_null(const char* str, int n, void* dest) { |
| // We fail if somebody asked us to store into a non-NULL void* pointer |
| return (dest == NULL); |
| } |
| |
| bool RE2::Arg::parse_string(const char* str, int n, void* dest) { |
| if (dest == NULL) return true; |
| reinterpret_cast<string*>(dest)->assign(str, n); |
| return true; |
| } |
| |
| bool RE2::Arg::parse_stringpiece(const char* str, int n, void* dest) { |
| if (dest == NULL) return true; |
| reinterpret_cast<StringPiece*>(dest)->set(str, n); |
| return true; |
| } |
| |
| bool RE2::Arg::parse_char(const char* str, int n, void* dest) { |
| if (n != 1) return false; |
| if (dest == NULL) return true; |
| *(reinterpret_cast<char*>(dest)) = str[0]; |
| return true; |
| } |
| |
| bool RE2::Arg::parse_uchar(const char* str, int n, void* dest) { |
| if (n != 1) return false; |
| if (dest == NULL) return true; |
| *(reinterpret_cast<unsigned char*>(dest)) = str[0]; |
| return true; |
| } |
| |
| // Largest number spec that we are willing to parse |
| static const int kMaxNumberLength = 32; |
| |
| // REQUIRES "buf" must have length at least kMaxNumberLength+1 |
| // Copies "str" into "buf" and null-terminates. |
| // Overwrites *np with the new length. |
| static const char* TerminateNumber(char* buf, const char* str, int* np) { |
| int n = *np; |
| if (n <= 0) return ""; |
| if (n > 0 && isspace(*str)) { |
| // We are less forgiving than the strtoxxx() routines and do not |
| // allow leading spaces. |
| return ""; |
| } |
| |
| // Although buf has a fixed maximum size, we can still handle |
| // arbitrarily large integers correctly by omitting leading zeros. |
| // (Numbers that are still too long will be out of range.) |
| // Before deciding whether str is too long, |
| // remove leading zeros with s/000+/00/. |
| // Leaving the leading two zeros in place means that |
| // we don't change 0000x123 (invalid) into 0x123 (valid). |
| // Skip over leading - before replacing. |
| bool neg = false; |
| if (n >= 1 && str[0] == '-') { |
| neg = true; |
| n--; |
| str++; |
| } |
| |
| if (n >= 3 && str[0] == '0' && str[1] == '0') { |
| while (n >= 3 && str[2] == '0') { |
| n--; |
| str++; |
| } |
| } |
| |
| if (neg) { // make room in buf for - |
| n++; |
| str--; |
| } |
| |
| if (n > kMaxNumberLength) return ""; |
| |
| memmove(buf, str, n); |
| if (neg) { |
| buf[0] = '-'; |
| } |
| buf[n] = '\0'; |
| *np = n; |
| return buf; |
| } |
| |
| bool RE2::Arg::parse_long_radix(const char* str, |
| int n, |
| void* dest, |
| int radix) { |
| if (n == 0) return false; |
| char buf[kMaxNumberLength+1]; |
| str = TerminateNumber(buf, str, &n); |
| char* end; |
| errno = 0; |
| long r = strtol(str, &end, radix); |
| if (end != str + n) return false; // Leftover junk |
| if (errno) return false; |
| if (dest == NULL) return true; |
| *(reinterpret_cast<long*>(dest)) = r; |
| return true; |
| } |
| |
| bool RE2::Arg::parse_ulong_radix(const char* str, |
| int n, |
| void* dest, |
| int radix) { |
| if (n == 0) return false; |
| char buf[kMaxNumberLength+1]; |
| str = TerminateNumber(buf, str, &n); |
| if (str[0] == '-') { |
| // strtoul() will silently accept negative numbers and parse |
| // them. This module is more strict and treats them as errors. |
| return false; |
| } |
| |
| char* end; |
| errno = 0; |
| unsigned long r = strtoul(str, &end, radix); |
| if (end != str + n) return false; // Leftover junk |
| if (errno) return false; |
| if (dest == NULL) return true; |
| *(reinterpret_cast<unsigned long*>(dest)) = r; |
| return true; |
| } |
| |
| bool RE2::Arg::parse_short_radix(const char* str, |
| int n, |
| void* dest, |
| int radix) { |
| long r; |
| if (!parse_long_radix(str, n, &r, radix)) return false; // Could not parse |
| if ((short)r != r) return false; // Out of range |
| if (dest == NULL) return true; |
| *(reinterpret_cast<short*>(dest)) = r; |
| return true; |
| } |
| |
| bool RE2::Arg::parse_ushort_radix(const char* str, |
| int n, |
| void* dest, |
| int radix) { |
| unsigned long r; |
| if (!parse_ulong_radix(str, n, &r, radix)) return false; // Could not parse |
| if ((ushort)r != r) return false; // Out of range |
| if (dest == NULL) return true; |
| *(reinterpret_cast<unsigned short*>(dest)) = r; |
| return true; |
| } |
| |
| bool RE2::Arg::parse_int_radix(const char* str, |
| int n, |
| void* dest, |
| int radix) { |
| long r; |
| if (!parse_long_radix(str, n, &r, radix)) return false; // Could not parse |
| if ((int)r != r) return false; // Out of range |
| if (dest == NULL) return true; |
| *(reinterpret_cast<int*>(dest)) = r; |
| return true; |
| } |
| |
| bool RE2::Arg::parse_uint_radix(const char* str, |
| int n, |
| void* dest, |
| int radix) { |
| unsigned long r; |
| if (!parse_ulong_radix(str, n, &r, radix)) return false; // Could not parse |
| if ((uint)r != r) return false; // Out of range |
| if (dest == NULL) return true; |
| *(reinterpret_cast<unsigned int*>(dest)) = r; |
| return true; |
| } |
| |
| bool RE2::Arg::parse_longlong_radix(const char* str, |
| int n, |
| void* dest, |
| int radix) { |
| if (n == 0) return false; |
| char buf[kMaxNumberLength+1]; |
| str = TerminateNumber(buf, str, &n); |
| char* end; |
| errno = 0; |
| int64 r = strtoll(str, &end, radix); |
| if (end != str + n) return false; // Leftover junk |
| if (errno) return false; |
| if (dest == NULL) return true; |
| *(reinterpret_cast<int64*>(dest)) = r; |
| return true; |
| } |
| |
| bool RE2::Arg::parse_ulonglong_radix(const char* str, |
| int n, |
| void* dest, |
| int radix) { |
| if (n == 0) return false; |
| char buf[kMaxNumberLength+1]; |
| str = TerminateNumber(buf, str, &n); |
| if (str[0] == '-') { |
| // strtoull() will silently accept negative numbers and parse |
| // them. This module is more strict and treats them as errors. |
| return false; |
| } |
| char* end; |
| errno = 0; |
| uint64 r = strtoull(str, &end, radix); |
| if (end != str + n) return false; // Leftover junk |
| if (errno) return false; |
| if (dest == NULL) return true; |
| *(reinterpret_cast<uint64*>(dest)) = r; |
| return true; |
| } |
| |
| static bool parse_double_float(const char* str, int n, bool isfloat, void *dest) { |
| if (n == 0) return false; |
| static const int kMaxLength = 200; |
| char buf[kMaxLength]; |
| if (n >= kMaxLength) return false; |
| memcpy(buf, str, n); |
| buf[n] = '\0'; |
| errno = 0; |
| char* end; |
| double r; |
| if (isfloat) { |
| r = strtof(buf, &end); |
| } else { |
| r = strtod(buf, &end); |
| } |
| if (end != buf + n) return false; // Leftover junk |
| if (errno) return false; |
| if (dest == NULL) return true; |
| if (isfloat) { |
| *(reinterpret_cast<float*>(dest)) = r; |
| } else { |
| *(reinterpret_cast<double*>(dest)) = r; |
| } |
| return true; |
| } |
| |
| bool RE2::Arg::parse_double(const char* str, int n, void* dest) { |
| return parse_double_float(str, n, false, dest); |
| } |
| |
| bool RE2::Arg::parse_float(const char* str, int n, void* dest) { |
| return parse_double_float(str, n, true, dest); |
| } |
| |
| |
| #define DEFINE_INTEGER_PARSERS(name) \ |
| bool RE2::Arg::parse_##name(const char* str, int n, void* dest) { \ |
| return parse_##name##_radix(str, n, dest, 10); \ |
| } \ |
| bool RE2::Arg::parse_##name##_hex(const char* str, int n, void* dest) { \ |
| return parse_##name##_radix(str, n, dest, 16); \ |
| } \ |
| bool RE2::Arg::parse_##name##_octal(const char* str, int n, void* dest) { \ |
| return parse_##name##_radix(str, n, dest, 8); \ |
| } \ |
| bool RE2::Arg::parse_##name##_cradix(const char* str, int n, void* dest) { \ |
| return parse_##name##_radix(str, n, dest, 0); \ |
| } |
| |
| DEFINE_INTEGER_PARSERS(short); |
| DEFINE_INTEGER_PARSERS(ushort); |
| DEFINE_INTEGER_PARSERS(int); |
| DEFINE_INTEGER_PARSERS(uint); |
| DEFINE_INTEGER_PARSERS(long); |
| DEFINE_INTEGER_PARSERS(ulong); |
| DEFINE_INTEGER_PARSERS(longlong); |
| DEFINE_INTEGER_PARSERS(ulonglong); |
| |
| #undef DEFINE_INTEGER_PARSERS |
| |
| } // namespace re2 |
