Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(114)

Issues Search
    My Issues | Starred     Open | Closed | All

Unified Diff: src/regexp/regexp-parser.cc

Issue 1565183002: [regexp] move regexp parser into own files. (Closed) Base URL: https://chromium.googlesource.com/v8/v8.git@master
Patch Set: fix test compile Created 4 years, 11 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « src/regexp/regexp-parser.h ('k') | src/utils.h » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: src/regexp/regexp-parser.cc
diff --git a/src/regexp/regexp-parser.cc b/src/regexp/regexp-parser.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fd8906c79c394049778f8478697376fee53f79ce
--- /dev/null
+++ b/src/regexp/regexp-parser.cc
@@ -0,0 +1,1154 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/regexp/regexp-parser.h"
+
+#include "src/char-predicates-inl.h"
+#include "src/factory.h"
+#include "src/isolate.h"
+#include "src/objects-inl.h"
+#include "src/regexp/jsregexp.h"
+#include "src/utils.h"
+
+namespace v8 {
+namespace internal {
+
+RegExpParser::RegExpParser(FlatStringReader* in, Handle<String>* error,
+ bool multiline, bool unicode, Isolate* isolate,
+ Zone* zone)
+ : isolate_(isolate),
+ zone_(zone),
+ error_(error),
+ captures_(NULL),
+ in_(in),
+ current_(kEndMarker),
+ next_pos_(0),
+ captures_started_(0),
+ capture_count_(0),
+ has_more_(true),
+ multiline_(multiline),
+ unicode_(unicode),
+ simple_(false),
+ contains_anchor_(false),
+ is_scanned_for_captures_(false),
+ failed_(false) {
+ Advance();
+}
+
+
+uc32 RegExpParser::Next() {
+ if (has_next()) {
+ return in()->Get(next_pos_);
+ } else {
+ return kEndMarker;
+ }
+}
+
+
+void RegExpParser::Advance() {
+ if (next_pos_ < in()->length()) {
+ StackLimitCheck check(isolate());
+ if (check.HasOverflowed()) {
+ ReportError(CStrVector(Isolate::kStackOverflowMessage));
+ } else if (zone()->excess_allocation()) {
+ ReportError(CStrVector("Regular expression too large"));
+ } else {
+ current_ = in()->Get(next_pos_);
+ next_pos_++;
+ }
+ } else {
+ current_ = kEndMarker;
+ // Advance so that position() points to 1-after-the-last-character. This is
+ // important so that Reset() to this position works correctly.
+ next_pos_ = in()->length() + 1;
+ has_more_ = false;
+ }
+}
+
+
+void RegExpParser::Reset(int pos) {
+ next_pos_ = pos;
+ has_more_ = (pos < in()->length());
+ Advance();
+}
+
+
+void RegExpParser::Advance(int dist) {
+ next_pos_ += dist - 1;
+ Advance();
+}
+
+
+bool RegExpParser::simple() { return simple_; }
+
+
+bool RegExpParser::IsSyntaxCharacter(uc32 c) {
+ return c == '^' || c == '$' || c == '\\' || c == '.' || c == '*' ||
+ c == '+' || c == '?' || c == '(' || c == ')' || c == '[' || c == ']' ||
+ c == '{' || c == '}' || c == '|';
+}
+
+
+RegExpTree* RegExpParser::ReportError(Vector<const char> message) {
+ failed_ = true;
+ *error_ = isolate()->factory()->NewStringFromAscii(message).ToHandleChecked();
+ // Zip to the end to make sure the no more input is read.
+ current_ = kEndMarker;
+ next_pos_ = in()->length();
+ return NULL;
+}
+
+
+#define CHECK_FAILED /**/); \
+ if (failed_) return NULL; \
+ ((void)0
+
+
+// Pattern ::
+// Disjunction
+RegExpTree* RegExpParser::ParsePattern() {
+ RegExpTree* result = ParseDisjunction(CHECK_FAILED);
+ DCHECK(!has_more());
+ // If the result of parsing is a literal string atom, and it has the
+ // same length as the input, then the atom is identical to the input.
+ if (result->IsAtom() && result->AsAtom()->length() == in()->length()) {
+ simple_ = true;
+ }
+ return result;
+}
+
+
+// Disjunction ::
+// Alternative
+// Alternative | Disjunction
+// Alternative ::
+// [empty]
+// Term Alternative
+// Term ::
+// Assertion
+// Atom
+// Atom Quantifier
+RegExpTree* RegExpParser::ParseDisjunction() {
+ // Used to store current state while parsing subexpressions.
+ RegExpParserState initial_state(NULL, INITIAL, RegExpLookaround::LOOKAHEAD, 0,
+ zone());
+ RegExpParserState* state = &initial_state;
+ // Cache the builder in a local variable for quick access.
+ RegExpBuilder* builder = initial_state.builder();
+ while (true) {
+ switch (current()) {
+ case kEndMarker:
+ if (state->IsSubexpression()) {
+ // Inside a parenthesized group when hitting end of input.
+ ReportError(CStrVector("Unterminated group") CHECK_FAILED);
+ }
+ DCHECK_EQ(INITIAL, state->group_type());
+ // Parsing completed successfully.
+ return builder->ToRegExp();
+ case ')': {
+ if (!state->IsSubexpression()) {
+ ReportError(CStrVector("Unmatched ')'") CHECK_FAILED);
+ }
+ DCHECK_NE(INITIAL, state->group_type());
+
+ Advance();
+ // End disjunction parsing and convert builder content to new single
+ // regexp atom.
+ RegExpTree* body = builder->ToRegExp();
+
+ int end_capture_index = captures_started();
+
+ int capture_index = state->capture_index();
+ SubexpressionType group_type = state->group_type();
+
+ // Build result of subexpression.
+ if (group_type == CAPTURE) {
+ RegExpCapture* capture = GetCapture(capture_index);
+ capture->set_body(body);
+ body = capture;
+ } else if (group_type != GROUPING) {
+ DCHECK(group_type == POSITIVE_LOOKAROUND ||
+ group_type == NEGATIVE_LOOKAROUND);
+ bool is_positive = (group_type == POSITIVE_LOOKAROUND);
+ body = new (zone()) RegExpLookaround(
+ body, is_positive, end_capture_index - capture_index,
+ capture_index, state->lookaround_type());
+ }
+
+ // Restore previous state.
+ state = state->previous_state();
+ builder = state->builder();
+
+ builder->AddAtom(body);
+ // For compatability with JSC and ES3, we allow quantifiers after
+ // lookaheads, and break in all cases.
+ break;
+ }
+ case '|': {
+ Advance();
+ builder->NewAlternative();
+ continue;
+ }
+ case '*':
+ case '+':
+ case '?':
+ return ReportError(CStrVector("Nothing to repeat"));
+ case '^': {
+ Advance();
+ if (multiline_) {
+ builder->AddAssertion(
+ new (zone()) RegExpAssertion(RegExpAssertion::START_OF_LINE));
+ } else {
+ builder->AddAssertion(
+ new (zone()) RegExpAssertion(RegExpAssertion::START_OF_INPUT));
+ set_contains_anchor();
+ }
+ continue;
+ }
+ case '$': {
+ Advance();
+ RegExpAssertion::AssertionType assertion_type =
+ multiline_ ? RegExpAssertion::END_OF_LINE
+ : RegExpAssertion::END_OF_INPUT;
+ builder->AddAssertion(new (zone()) RegExpAssertion(assertion_type));
+ continue;
+ }
+ case '.': {
+ Advance();
+ // everything except \x0a, \x0d, \u2028 and \u2029
+ ZoneList<CharacterRange>* ranges =
+ new (zone()) ZoneList<CharacterRange>(2, zone());
+ CharacterRange::AddClassEscape('.', ranges, zone());
+ RegExpTree* atom = new (zone()) RegExpCharacterClass(ranges, false);
+ builder->AddAtom(atom);
+ break;
+ }
+ case '(': {
+ SubexpressionType subexpr_type = CAPTURE;
+ RegExpLookaround::Type lookaround_type = state->lookaround_type();
+ Advance();
+ if (current() == '?') {
+ switch (Next()) {
+ case ':':
+ subexpr_type = GROUPING;
+ break;
+ case '=':
+ lookaround_type = RegExpLookaround::LOOKAHEAD;
+ subexpr_type = POSITIVE_LOOKAROUND;
+ break;
+ case '!':
+ lookaround_type = RegExpLookaround::LOOKAHEAD;
+ subexpr_type = NEGATIVE_LOOKAROUND;
+ break;
+ case '<':
+ if (FLAG_harmony_regexp_lookbehind) {
+ Advance();
+ lookaround_type = RegExpLookaround::LOOKBEHIND;
+ if (Next() == '=') {
+ subexpr_type = POSITIVE_LOOKAROUND;
+ break;
+ } else if (Next() == '!') {
+ subexpr_type = NEGATIVE_LOOKAROUND;
+ break;
+ }
+ }
+ // Fall through.
+ default:
+ ReportError(CStrVector("Invalid group") CHECK_FAILED);
+ break;
+ }
+ Advance(2);
+ } else {
+ if (captures_started_ >= kMaxCaptures) {
+ ReportError(CStrVector("Too many captures") CHECK_FAILED);
+ }
+ captures_started_++;
+ }
+ // Store current state and begin new disjunction parsing.
+ state = new (zone()) RegExpParserState(
+ state, subexpr_type, lookaround_type, captures_started_, zone());
+ builder = state->builder();
+ continue;
+ }
+ case '[': {
+ RegExpTree* atom = ParseCharacterClass(CHECK_FAILED);
+ builder->AddAtom(atom);
+ break;
+ }
+ // Atom ::
+ // \ AtomEscape
+ case '\\':
+ switch (Next()) {
+ case kEndMarker:
+ return ReportError(CStrVector("\\ at end of pattern"));
+ case 'b':
+ Advance(2);
+ builder->AddAssertion(
+ new (zone()) RegExpAssertion(RegExpAssertion::BOUNDARY));
+ continue;
+ case 'B':
+ Advance(2);
+ builder->AddAssertion(
+ new (zone()) RegExpAssertion(RegExpAssertion::NON_BOUNDARY));
+ continue;
+ // AtomEscape ::
+ // CharacterClassEscape
+ //
+ // CharacterClassEscape :: one of
+ // d D s S w W
+ case 'd':
+ case 'D':
+ case 's':
+ case 'S':
+ case 'w':
+ case 'W': {
+ uc32 c = Next();
+ Advance(2);
+ ZoneList<CharacterRange>* ranges =
+ new (zone()) ZoneList<CharacterRange>(2, zone());
+ CharacterRange::AddClassEscape(c, ranges, zone());
+ RegExpTree* atom = new (zone()) RegExpCharacterClass(ranges, false);
+ builder->AddAtom(atom);
+ break;
+ }
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ case '5':
+ case '6':
+ case '7':
+ case '8':
+ case '9': {
+ int index = 0;
+ if (ParseBackReferenceIndex(&index)) {
+ if (state->IsInsideCaptureGroup(index)) {
+ // The back reference is inside the capture group it refers to.
+ // Nothing can possibly have been captured yet, so we use empty
+ // instead. This ensures that, when checking a back reference,
+ // the capture registers of the referenced capture are either
+ // both set or both cleared.
+ builder->AddEmpty();
+ } else {
+ RegExpCapture* capture = GetCapture(index);
+ RegExpTree* atom = new (zone()) RegExpBackReference(capture);
+ builder->AddAtom(atom);
+ }
+ break;
+ }
+ uc32 first_digit = Next();
+ if (first_digit == '8' || first_digit == '9') {
+ // If the 'u' flag is present, only syntax characters can be
+ // escaped,
+ // no other identity escapes are allowed. If the 'u' flag is not
+ // present, all identity escapes are allowed.
+ if (!FLAG_harmony_unicode_regexps || !unicode_) {
+ builder->AddCharacter(first_digit);
+ Advance(2);
+ } else {
+ return ReportError(CStrVector("Invalid escape"));
+ }
+ break;
+ }
+ }
+ // FALLTHROUGH
+ case '0': {
+ Advance();
+ uc32 octal = ParseOctalLiteral();
+ builder->AddCharacter(octal);
+ break;
+ }
+ // ControlEscape :: one of
+ // f n r t v
+ case 'f':
+ Advance(2);
+ builder->AddCharacter('\f');
+ break;
+ case 'n':
+ Advance(2);
+ builder->AddCharacter('\n');
+ break;
+ case 'r':
+ Advance(2);
+ builder->AddCharacter('\r');
+ break;
+ case 't':
+ Advance(2);
+ builder->AddCharacter('\t');
+ break;
+ case 'v':
+ Advance(2);
+ builder->AddCharacter('\v');
+ break;
+ case 'c': {
+ Advance();
+ uc32 controlLetter = Next();
+ // Special case if it is an ASCII letter.
+ // Convert lower case letters to uppercase.
+ uc32 letter = controlLetter & ~('a' ^ 'A');
+ if (letter < 'A' || 'Z' < letter) {
+ // controlLetter is not in range 'A'-'Z' or 'a'-'z'.
+ // This is outside the specification. We match JSC in
+ // reading the backslash as a literal character instead
+ // of as starting an escape.
+ builder->AddCharacter('\\');
+ } else {
+ Advance(2);
+ builder->AddCharacter(controlLetter & 0x1f);
+ }
+ break;
+ }
+ case 'x': {
+ Advance(2);
+ uc32 value;
+ if (ParseHexEscape(2, &value)) {
+ builder->AddCharacter(value);
+ } else if (!FLAG_harmony_unicode_regexps || !unicode_) {
+ builder->AddCharacter('x');
+ } else {
+ // If the 'u' flag is present, invalid escapes are not treated as
+ // identity escapes.
+ return ReportError(CStrVector("Invalid escape"));
+ }
+ break;
+ }
+ case 'u': {
+ Advance(2);
+ uc32 value;
+ if (ParseUnicodeEscape(&value)) {
+ builder->AddCharacter(value);
+ } else if (!FLAG_harmony_unicode_regexps || !unicode_) {
+ builder->AddCharacter('u');
+ } else {
+ // If the 'u' flag is present, invalid escapes are not treated as
+ // identity escapes.
+ return ReportError(CStrVector("Invalid unicode escape"));
+ }
+ break;
+ }
+ default:
+ Advance();
+ // If the 'u' flag is present, only syntax characters can be
+ // escaped, no
+ // other identity escapes are allowed. If the 'u' flag is not
+ // present,
+ // all identity escapes are allowed.
+ if (!FLAG_harmony_unicode_regexps || !unicode_ ||
+ IsSyntaxCharacter(current())) {
+ builder->AddCharacter(current());
+ Advance();
+ } else {
+ return ReportError(CStrVector("Invalid escape"));
+ }
+ break;
+ }
+ break;
+ case '{': {
+ int dummy;
+ if (ParseIntervalQuantifier(&dummy, &dummy)) {
+ ReportError(CStrVector("Nothing to repeat") CHECK_FAILED);
+ }
+ // fallthrough
+ }
+ default:
+ builder->AddCharacter(current());
+ Advance();
+ break;
+ } // end switch(current())
+
+ int min;
+ int max;
+ switch (current()) {
+ // QuantifierPrefix ::
+ // *
+ // +
+ // ?
+ // {
+ case '*':
+ min = 0;
+ max = RegExpTree::kInfinity;
+ Advance();
+ break;
+ case '+':
+ min = 1;
+ max = RegExpTree::kInfinity;
+ Advance();
+ break;
+ case '?':
+ min = 0;
+ max = 1;
+ Advance();
+ break;
+ case '{':
+ if (ParseIntervalQuantifier(&min, &max)) {
+ if (max < min) {
+ ReportError(CStrVector("numbers out of order in {} quantifier.")
+ CHECK_FAILED);
+ }
+ break;
+ } else {
+ continue;
+ }
+ default:
+ continue;
+ }
+ RegExpQuantifier::QuantifierType quantifier_type = RegExpQuantifier::GREEDY;
+ if (current() == '?') {
+ quantifier_type = RegExpQuantifier::NON_GREEDY;
+ Advance();
+ } else if (FLAG_regexp_possessive_quantifier && current() == '+') {
+ // FLAG_regexp_possessive_quantifier is a debug-only flag.
+ quantifier_type = RegExpQuantifier::POSSESSIVE;
+ Advance();
+ }
+ builder->AddQuantifierToAtom(min, max, quantifier_type);
+ }
+}
+
+
+#ifdef DEBUG
+// Currently only used in an DCHECK.
+static bool IsSpecialClassEscape(uc32 c) {
+ switch (c) {
+ case 'd':
+ case 'D':
+ case 's':
+ case 'S':
+ case 'w':
+ case 'W':
+ return true;
+ default:
+ return false;
+ }
+}
+#endif
+
+
+// In order to know whether an escape is a backreference or not we have to scan
+// the entire regexp and find the number of capturing parentheses. However we
+// don't want to scan the regexp twice unless it is necessary. This mini-parser
+// is called when needed. It can see the difference between capturing and
+// noncapturing parentheses and can skip character classes and backslash-escaped
+// characters.
+void RegExpParser::ScanForCaptures() {
+ // Start with captures started previous to current position
+ int capture_count = captures_started();
+ // Add count of captures after this position.
+ int n;
+ while ((n = current()) != kEndMarker) {
+ Advance();
+ switch (n) {
+ case '\\':
+ Advance();
+ break;
+ case '[': {
+ int c;
+ while ((c = current()) != kEndMarker) {
+ Advance();
+ if (c == '\\') {
+ Advance();
+ } else {
+ if (c == ']') break;
+ }
+ }
+ break;
+ }
+ case '(':
+ if (current() != '?') capture_count++;
+ break;
+ }
+ }
+ capture_count_ = capture_count;
+ is_scanned_for_captures_ = true;
+}
+
+
+bool RegExpParser::ParseBackReferenceIndex(int* index_out) {
+ DCHECK_EQ('\\', current());
+ DCHECK('1' <= Next() && Next() <= '9');
+ // Try to parse a decimal literal that is no greater than the total number
+ // of left capturing parentheses in the input.
+ int start = position();
+ int value = Next() - '0';
+ Advance(2);
+ while (true) {
+ uc32 c = current();
+ if (IsDecimalDigit(c)) {
+ value = 10 * value + (c - '0');
+ if (value > kMaxCaptures) {
+ Reset(start);
+ return false;
+ }
+ Advance();
+ } else {
+ break;
+ }
+ }
+ if (value > captures_started()) {
+ if (!is_scanned_for_captures_) {
+ int saved_position = position();
+ ScanForCaptures();
+ Reset(saved_position);
+ }
+ if (value > capture_count_) {
+ Reset(start);
+ return false;
+ }
+ }
+ *index_out = value;
+ return true;
+}
+
+
+RegExpCapture* RegExpParser::GetCapture(int index) {
+ // The index for the capture groups are one-based. Its index in the list is
+ // zero-based.
+ int know_captures =
+ is_scanned_for_captures_ ? capture_count_ : captures_started_;
+ DCHECK(index <= know_captures);
+ if (captures_ == NULL) {
+ captures_ = new (zone()) ZoneList<RegExpCapture*>(know_captures, zone());
+ }
+ while (captures_->length() < know_captures) {
+ captures_->Add(new (zone()) RegExpCapture(captures_->length() + 1), zone());
+ }
+ return captures_->at(index - 1);
+}
+
+
+bool RegExpParser::RegExpParserState::IsInsideCaptureGroup(int index) {
+ for (RegExpParserState* s = this; s != NULL; s = s->previous_state()) {
+ if (s->group_type() != CAPTURE) continue;
+ // Return true if we found the matching capture index.
+ if (index == s->capture_index()) return true;
+ // Abort if index is larger than what has been parsed up till this state.
+ if (index > s->capture_index()) return false;
+ }
+ return false;
+}
+
+
+// QuantifierPrefix ::
+// { DecimalDigits }
+// { DecimalDigits , }
+// { DecimalDigits , DecimalDigits }
+//
+// Returns true if parsing succeeds, and set the min_out and max_out
+// values. Values are truncated to RegExpTree::kInfinity if they overflow.
+bool RegExpParser::ParseIntervalQuantifier(int* min_out, int* max_out) {
+ DCHECK_EQ(current(), '{');
+ int start = position();
+ Advance();
+ int min = 0;
+ if (!IsDecimalDigit(current())) {
+ Reset(start);
+ return false;
+ }
+ while (IsDecimalDigit(current())) {
+ int next = current() - '0';
+ if (min > (RegExpTree::kInfinity - next) / 10) {
+ // Overflow. Skip past remaining decimal digits and return -1.
+ do {
+ Advance();
+ } while (IsDecimalDigit(current()));
+ min = RegExpTree::kInfinity;
+ break;
+ }
+ min = 10 * min + next;
+ Advance();
+ }
+ int max = 0;
+ if (current() == '}') {
+ max = min;
+ Advance();
+ } else if (current() == ',') {
+ Advance();
+ if (current() == '}') {
+ max = RegExpTree::kInfinity;
+ Advance();
+ } else {
+ while (IsDecimalDigit(current())) {
+ int next = current() - '0';
+ if (max > (RegExpTree::kInfinity - next) / 10) {
+ do {
+ Advance();
+ } while (IsDecimalDigit(current()));
+ max = RegExpTree::kInfinity;
+ break;
+ }
+ max = 10 * max + next;
+ Advance();
+ }
+ if (current() != '}') {
+ Reset(start);
+ return false;
+ }
+ Advance();
+ }
+ } else {
+ Reset(start);
+ return false;
+ }
+ *min_out = min;
+ *max_out = max;
+ return true;
+}
+
+
+uc32 RegExpParser::ParseOctalLiteral() {
+ DCHECK(('0' <= current() && current() <= '7') || current() == kEndMarker);
+ // For compatibility with some other browsers (not all), we parse
+ // up to three octal digits with a value below 256.
+ uc32 value = current() - '0';
+ Advance();
+ if ('0' <= current() && current() <= '7') {
+ value = value * 8 + current() - '0';
+ Advance();
+ if (value < 32 && '0' <= current() && current() <= '7') {
+ value = value * 8 + current() - '0';
+ Advance();
+ }
+ }
+ return value;
+}
+
+
+bool RegExpParser::ParseHexEscape(int length, uc32* value) {
+ int start = position();
+ uc32 val = 0;
+ for (int i = 0; i < length; ++i) {
+ uc32 c = current();
+ int d = HexValue(c);
+ if (d < 0) {
+ Reset(start);
+ return false;
+ }
+ val = val * 16 + d;
+ Advance();
+ }
+ *value = val;
+ return true;
+}
+
+
+bool RegExpParser::ParseUnicodeEscape(uc32* value) {
+ // Accept both \uxxxx and \u{xxxxxx} (if harmony unicode escapes are
+ // allowed). In the latter case, the number of hex digits between { } is
+ // arbitrary. \ and u have already been read.
+ if (current() == '{' && FLAG_harmony_unicode_regexps && unicode_) {
+ int start = position();
+ Advance();
+ if (ParseUnlimitedLengthHexNumber(0x10ffff, value)) {
+ if (current() == '}') {
+ Advance();
+ return true;
+ }
+ }
+ Reset(start);
+ return false;
+ }
+ // \u but no {, or \u{...} escapes not allowed.
+ return ParseHexEscape(4, value);
+}
+
+
+bool RegExpParser::ParseUnlimitedLengthHexNumber(int max_value, uc32* value) {
+ uc32 x = 0;
+ int d = HexValue(current());
+ if (d < 0) {
+ return false;
+ }
+ while (d >= 0) {
+ x = x * 16 + d;
+ if (x > max_value) {
+ return false;
+ }
+ Advance();
+ d = HexValue(current());
+ }
+ *value = x;
+ return true;
+}
+
+
+uc32 RegExpParser::ParseClassCharacterEscape() {
+ DCHECK(current() == '\\');
+ DCHECK(has_next() && !IsSpecialClassEscape(Next()));
+ Advance();
+ switch (current()) {
+ case 'b':
+ Advance();
+ return '\b';
+ // ControlEscape :: one of
+ // f n r t v
+ case 'f':
+ Advance();
+ return '\f';
+ case 'n':
+ Advance();
+ return '\n';
+ case 'r':
+ Advance();
+ return '\r';
+ case 't':
+ Advance();
+ return '\t';
+ case 'v':
+ Advance();
+ return '\v';
+ case 'c': {
+ uc32 controlLetter = Next();
+ uc32 letter = controlLetter & ~('A' ^ 'a');
+ // For compatibility with JSC, inside a character class
+ // we also accept digits and underscore as control characters.
+ if ((controlLetter >= '0' && controlLetter <= '9') ||
+ controlLetter == '_' || (letter >= 'A' && letter <= 'Z')) {
+ Advance(2);
+ // Control letters mapped to ASCII control characters in the range
+ // 0x00-0x1f.
+ return controlLetter & 0x1f;
+ }
+ // We match JSC in reading the backslash as a literal
+ // character instead of as starting an escape.
+ return '\\';
+ }
+ case '0':
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ case '5':
+ case '6':
+ case '7':
+ // For compatibility, we interpret a decimal escape that isn't
+ // a back reference (and therefore either \0 or not valid according
+ // to the specification) as a 1..3 digit octal character code.
+ return ParseOctalLiteral();
+ case 'x': {
+ Advance();
+ uc32 value;
+ if (ParseHexEscape(2, &value)) {
+ return value;
+ }
+ if (!FLAG_harmony_unicode_regexps || !unicode_) {
+ // If \x is not followed by a two-digit hexadecimal, treat it
+ // as an identity escape.
+ return 'x';
+ }
+ // If the 'u' flag is present, invalid escapes are not treated as
+ // identity escapes.
+ ReportError(CStrVector("Invalid escape"));
+ return 0;
+ }
+ case 'u': {
+ Advance();
+ uc32 value;
+ if (ParseUnicodeEscape(&value)) {
+ return value;
+ }
+ if (!FLAG_harmony_unicode_regexps || !unicode_) {
+ return 'u';
+ }
+ // If the 'u' flag is present, invalid escapes are not treated as
+ // identity escapes.
+ ReportError(CStrVector("Invalid unicode escape"));
+ return 0;
+ }
+ default: {
+ uc32 result = current();
+ // If the 'u' flag is present, only syntax characters can be escaped, no
+ // other identity escapes are allowed. If the 'u' flag is not present, all
+ // identity escapes are allowed.
+ if (!FLAG_harmony_unicode_regexps || !unicode_ ||
+ IsSyntaxCharacter(result)) {
+ Advance();
+ return result;
+ }
+ ReportError(CStrVector("Invalid escape"));
+ return 0;
+ }
+ }
+ return 0;
+}
+
+
+CharacterRange RegExpParser::ParseClassAtom(uc16* char_class) {
+ DCHECK_EQ(0, *char_class);
+ uc32 first = current();
+ if (first == '\\') {
+ switch (Next()) {
+ case 'w':
+ case 'W':
+ case 'd':
+ case 'D':
+ case 's':
+ case 'S': {
+ *char_class = Next();
+ Advance(2);
+ return CharacterRange::Singleton(0); // Return dummy value.
+ }
+ case kEndMarker:
+ return ReportError(CStrVector("\\ at end of pattern"));
+ default:
+ uc32 c = ParseClassCharacterEscape(CHECK_FAILED);
+ return CharacterRange::Singleton(c);
+ }
+ } else {
+ Advance();
+ return CharacterRange::Singleton(first);
+ }
+}
+
+
+static const uc16 kNoCharClass = 0;
+
+// Adds range or pre-defined character class to character ranges.
+// If char_class is not kInvalidClass, it's interpreted as a class
+// escape (i.e., 's' means whitespace, from '\s').
+static inline void AddRangeOrEscape(ZoneList<CharacterRange>* ranges,
+ uc16 char_class, CharacterRange range,
+ Zone* zone) {
+ if (char_class != kNoCharClass) {
+ CharacterRange::AddClassEscape(char_class, ranges, zone);
+ } else {
+ ranges->Add(range, zone);
+ }
+}
+
+
+RegExpTree* RegExpParser::ParseCharacterClass() {
+ static const char* kUnterminated = "Unterminated character class";
+ static const char* kRangeOutOfOrder = "Range out of order in character class";
+
+ DCHECK_EQ(current(), '[');
+ Advance();
+ bool is_negated = false;
+ if (current() == '^') {
+ is_negated = true;
+ Advance();
+ }
+ ZoneList<CharacterRange>* ranges =
+ new (zone()) ZoneList<CharacterRange>(2, zone());
+ while (has_more() && current() != ']') {
+ uc16 char_class = kNoCharClass;
+ CharacterRange first = ParseClassAtom(&char_class CHECK_FAILED);
+ if (current() == '-') {
+ Advance();
+ if (current() == kEndMarker) {
+ // If we reach the end we break out of the loop and let the
+ // following code report an error.
+ break;
+ } else if (current() == ']') {
+ AddRangeOrEscape(ranges, char_class, first, zone());
+ ranges->Add(CharacterRange::Singleton('-'), zone());
+ break;
+ }
+ uc16 char_class_2 = kNoCharClass;
+ CharacterRange next = ParseClassAtom(&char_class_2 CHECK_FAILED);
+ if (char_class != kNoCharClass || char_class_2 != kNoCharClass) {
+ // Either end is an escaped character class. Treat the '-' verbatim.
+ AddRangeOrEscape(ranges, char_class, first, zone());
+ ranges->Add(CharacterRange::Singleton('-'), zone());
+ AddRangeOrEscape(ranges, char_class_2, next, zone());
+ continue;
+ }
+ if (first.from() > next.to()) {
+ return ReportError(CStrVector(kRangeOutOfOrder) CHECK_FAILED);
+ }
+ ranges->Add(CharacterRange::Range(first.from(), next.to()), zone());
+ } else {
+ AddRangeOrEscape(ranges, char_class, first, zone());
+ }
+ }
+ if (!has_more()) {
+ return ReportError(CStrVector(kUnterminated) CHECK_FAILED);
+ }
+ Advance();
+ if (ranges->length() == 0) {
+ ranges->Add(CharacterRange::Everything(), zone());
+ is_negated = !is_negated;
+ }
+ return new (zone()) RegExpCharacterClass(ranges, is_negated);
+}
+
+
+#undef CHECK_FAILED
+
+
+bool RegExpParser::ParseRegExp(Isolate* isolate, Zone* zone,
+ FlatStringReader* input, bool multiline,
+ bool unicode, RegExpCompileData* result) {
+ DCHECK(result != NULL);
+ RegExpParser parser(input, &result->error, multiline, unicode, isolate, zone);
+ RegExpTree* tree = parser.ParsePattern();
+ if (parser.failed()) {
+ DCHECK(tree == NULL);
+ DCHECK(!result->error.is_null());
+ } else {
+ DCHECK(tree != NULL);
+ DCHECK(result->error.is_null());
+ result->tree = tree;
+ int capture_count = parser.captures_started();
+ result->simple = tree->IsAtom() && parser.simple() && capture_count == 0;
+ result->contains_anchor = parser.contains_anchor();
+ result->capture_count = capture_count;
+ }
+ return !parser.failed();
+}
+
+
+RegExpBuilder::RegExpBuilder(Zone* zone)
+ : zone_(zone),
+ pending_empty_(false),
+ characters_(NULL),
+ terms_(),
+ alternatives_()
+#ifdef DEBUG
+ ,
+ last_added_(ADD_NONE)
+#endif
+{
+}
+
+
+void RegExpBuilder::FlushCharacters() {
+ pending_empty_ = false;
+ if (characters_ != NULL) {
+ RegExpTree* atom = new (zone()) RegExpAtom(characters_->ToConstVector());
+ characters_ = NULL;
+ text_.Add(atom, zone());
+ LAST(ADD_ATOM);
+ }
+}
+
+
+void RegExpBuilder::FlushText() {
+ FlushCharacters();
+ int num_text = text_.length();
+ if (num_text == 0) {
+ return;
+ } else if (num_text == 1) {
+ terms_.Add(text_.last(), zone());
+ } else {
+ RegExpText* text = new (zone()) RegExpText(zone());
+ for (int i = 0; i < num_text; i++) text_.Get(i)->AppendToText(text, zone());
+ terms_.Add(text, zone());
+ }
+ text_.Clear();
+}
+
+
+void RegExpBuilder::AddCharacter(uc16 c) {
+ pending_empty_ = false;
+ if (characters_ == NULL) {
+ characters_ = new (zone()) ZoneList<uc16>(4, zone());
+ }
+ characters_->Add(c, zone());
+ LAST(ADD_CHAR);
+}
+
+
+void RegExpBuilder::AddEmpty() { pending_empty_ = true; }
+
+
+void RegExpBuilder::AddAtom(RegExpTree* term) {
+ if (term->IsEmpty()) {
+ AddEmpty();
+ return;
+ }
+ if (term->IsTextElement()) {
+ FlushCharacters();
+ text_.Add(term, zone());
+ } else {
+ FlushText();
+ terms_.Add(term, zone());
+ }
+ LAST(ADD_ATOM);
+}
+
+
+void RegExpBuilder::AddAssertion(RegExpTree* assert) {
+ FlushText();
+ terms_.Add(assert, zone());
+ LAST(ADD_ASSERT);
+}
+
+
+void RegExpBuilder::NewAlternative() { FlushTerms(); }
+
+
+void RegExpBuilder::FlushTerms() {
+ FlushText();
+ int num_terms = terms_.length();
+ RegExpTree* alternative;
+ if (num_terms == 0) {
+ alternative = new (zone()) RegExpEmpty();
+ } else if (num_terms == 1) {
+ alternative = terms_.last();
+ } else {
+ alternative = new (zone()) RegExpAlternative(terms_.GetList(zone()));
+ }
+ alternatives_.Add(alternative, zone());
+ terms_.Clear();
+ LAST(ADD_NONE);
+}
+
+
+RegExpTree* RegExpBuilder::ToRegExp() {
+ FlushTerms();
+ int num_alternatives = alternatives_.length();
+ if (num_alternatives == 0) return new (zone()) RegExpEmpty();
+ if (num_alternatives == 1) return alternatives_.last();
+ return new (zone()) RegExpDisjunction(alternatives_.GetList(zone()));
+}
+
+
+void RegExpBuilder::AddQuantifierToAtom(
+ int min, int max, RegExpQuantifier::QuantifierType quantifier_type) {
+ if (pending_empty_) {
+ pending_empty_ = false;
+ return;
+ }
+ RegExpTree* atom;
+ if (characters_ != NULL) {
+ DCHECK(last_added_ == ADD_CHAR);
+ // Last atom was character.
+ Vector<const uc16> char_vector = characters_->ToConstVector();
+ int num_chars = char_vector.length();
+ if (num_chars > 1) {
+ Vector<const uc16> prefix = char_vector.SubVector(0, num_chars - 1);
+ text_.Add(new (zone()) RegExpAtom(prefix), zone());
+ char_vector = char_vector.SubVector(num_chars - 1, num_chars);
+ }
+ characters_ = NULL;
+ atom = new (zone()) RegExpAtom(char_vector);
+ FlushText();
+ } else if (text_.length() > 0) {
+ DCHECK(last_added_ == ADD_ATOM);
+ atom = text_.RemoveLast();
+ FlushText();
+ } else if (terms_.length() > 0) {
+ DCHECK(last_added_ == ADD_ATOM);
+ atom = terms_.RemoveLast();
+ if (atom->max_match() == 0) {
+ // Guaranteed to only match an empty string.
+ LAST(ADD_TERM);
+ if (min == 0) {
+ return;
+ }
+ terms_.Add(atom, zone());
+ return;
+ }
+ } else {
+ // Only call immediately after adding an atom or character!
+ UNREACHABLE();
+ return;
+ }
+ terms_.Add(new (zone()) RegExpQuantifier(min, max, quantifier_type, atom),
+ zone());
+ LAST(ADD_TERM);
+}
+
+} // namespace internal
+} // namespace v8
« no previous file with comments | « src/regexp/regexp-parser.h ('k') | src/utils.h » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698