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chromium / v8 / v8 / refs/heads/main / . / src / regexp / regexp-parser.cc
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// 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/execution/isolate.h"
#include "src/objects/string-inl.h"
#include "src/regexp/regexp-ast.h"
#include "src/regexp/regexp-macro-assembler.h"
#include "src/regexp/regexp.h"
#include "src/strings/char-predicates-inl.h"
#include "src/utils/ostreams.h"
#include "src/utils/utils.h"
#include "src/zone/zone-allocator.h"
#include "src/zone/zone-list-inl.h"
#ifdef V8_INTL_SUPPORT
#include "unicode/uniset.h"
#include "unicode/unistr.h"
#include "unicode/usetiter.h"
#include "unicode/utf16.h" // For U16_NEXT
#endif // V8_INTL_SUPPORT
namespace v8 {
namespace internal {
namespace {
// Whether we're currently inside the ClassEscape production
// (tc39.es/ecma262/#prod-annexB-CharacterEscape).
enum class InClassEscapeState {
kInClass,
kNotInClass,
};
// The production used to derive ClassSetOperand.
enum class ClassSetOperandType {
kClassSetCharacter,
kClassStringDisjunction,
kNestedClass,
kCharacterClassEscape, // \ CharacterClassEscape is a special nested class,
// as we can fold it directly into another range.
kClassSetRange
};
class RegExpTextBuilder {
public:
using SmallRegExpTreeVector = SmallZoneVector<RegExpTree*, 8>;
RegExpTextBuilder(Zone* zone, SmallRegExpTreeVector* terms_storage,
RegExpFlags flags)
: zone_(zone), flags_(flags), terms_(terms_storage), text_(zone) {}
void AddCharacter(base::uc16 character);
void AddUnicodeCharacter(base::uc32 character);
void AddEscapedUnicodeCharacter(base::uc32 character);
void AddAtom(RegExpTree* atom);
void AddTerm(RegExpTree* term);
void AddClassRanges(RegExpClassRanges* cc);
void FlushPendingSurrogate();
void FlushText();
RegExpTree* PopLastAtom();
RegExpTree* ToRegExp();
private:
static const base::uc16 kNoPendingSurrogate = 0;
void AddLeadSurrogate(base::uc16 lead_surrogate);
void AddTrailSurrogate(base::uc16 trail_surrogate);
void FlushCharacters();
bool NeedsDesugaringForUnicode(RegExpClassRanges* cc);
bool NeedsDesugaringForIgnoreCase(base::uc32 c);
void AddClassRangesForDesugaring(base::uc32 c);
bool ignore_case() const { return IsIgnoreCase(flags_); }
bool IsUnicodeMode() const {
// Either /v or /u enable UnicodeMode
// https://tc39.es/ecma262/#sec-parsepattern
return IsUnicode(flags_) || IsUnicodeSets(flags_);
}
Zone* zone() const { return zone_; }
Zone* const zone_;
const RegExpFlags flags_;
ZoneList<base::uc16>* characters_ = nullptr;
base::uc16 pending_surrogate_ = kNoPendingSurrogate;
SmallRegExpTreeVector* terms_;
SmallRegExpTreeVector text_;
};
void RegExpTextBuilder::AddLeadSurrogate(base::uc16 lead_surrogate) {
DCHECK(unibrow::Utf16::IsLeadSurrogate(lead_surrogate));
FlushPendingSurrogate();
// Hold onto the lead surrogate, waiting for a trail surrogate to follow.
pending_surrogate_ = lead_surrogate;
}
void RegExpTextBuilder::AddTrailSurrogate(base::uc16 trail_surrogate) {
DCHECK(unibrow::Utf16::IsTrailSurrogate(trail_surrogate));
if (pending_surrogate_ != kNoPendingSurrogate) {
base::uc16 lead_surrogate = pending_surrogate_;
pending_surrogate_ = kNoPendingSurrogate;
DCHECK(unibrow::Utf16::IsLeadSurrogate(lead_surrogate));
base::uc32 combined =
unibrow::Utf16::CombineSurrogatePair(lead_surrogate, trail_surrogate);
if (NeedsDesugaringForIgnoreCase(combined)) {
AddClassRangesForDesugaring(combined);
} else {
ZoneList<base::uc16> surrogate_pair(2, zone());
surrogate_pair.Add(lead_surrogate, zone());
surrogate_pair.Add(trail_surrogate, zone());
RegExpAtom* atom =
zone()->New<RegExpAtom>(surrogate_pair.ToConstVector());
AddAtom(atom);
}
} else {
pending_surrogate_ = trail_surrogate;
FlushPendingSurrogate();
}
}
void RegExpTextBuilder::FlushPendingSurrogate() {
if (pending_surrogate_ != kNoPendingSurrogate) {
DCHECK(IsUnicodeMode());
base::uc32 c = pending_surrogate_;
pending_surrogate_ = kNoPendingSurrogate;
AddClassRangesForDesugaring(c);
}
}
void RegExpTextBuilder::FlushCharacters() {
FlushPendingSurrogate();
if (characters_ != nullptr) {
RegExpTree* atom = zone()->New<RegExpAtom>(characters_->ToConstVector());
characters_ = nullptr;
text_.emplace_back(atom);
}
}
void RegExpTextBuilder::FlushText() {
FlushCharacters();
size_t num_text = text_.size();
if (num_text == 0) {
return;
} else if (num_text == 1) {
terms_->emplace_back(text_.back());
} else {
RegExpText* text = zone()->New<RegExpText>(zone());
for (size_t i = 0; i < num_text; i++) {
text_[i]->AppendToText(text, zone());
}
terms_->emplace_back(text);
}
text_.clear();
}
void RegExpTextBuilder::AddCharacter(base::uc16 c) {
FlushPendingSurrogate();
if (characters_ == nullptr) {
characters_ = zone()->New<ZoneList<base::uc16>>(4, zone());
}
characters_->Add(c, zone());
}
void RegExpTextBuilder::AddUnicodeCharacter(base::uc32 c) {
if (c > static_cast<base::uc32>(unibrow::Utf16::kMaxNonSurrogateCharCode)) {
DCHECK(IsUnicodeMode());
AddLeadSurrogate(unibrow::Utf16::LeadSurrogate(c));
AddTrailSurrogate(unibrow::Utf16::TrailSurrogate(c));
} else if (IsUnicodeMode() && unibrow::Utf16::IsLeadSurrogate(c)) {
AddLeadSurrogate(c);
} else if (IsUnicodeMode() && unibrow::Utf16::IsTrailSurrogate(c)) {
AddTrailSurrogate(c);
} else {
AddCharacter(static_cast<base::uc16>(c));
}
}
void RegExpTextBuilder::AddEscapedUnicodeCharacter(base::uc32 character) {
// A lead or trail surrogate parsed via escape sequence will not
// pair up with any preceding lead or following trail surrogate.
FlushPendingSurrogate();
AddUnicodeCharacter(character);
FlushPendingSurrogate();
}
void RegExpTextBuilder::AddClassRanges(RegExpClassRanges* cr) {
if (NeedsDesugaringForUnicode(cr)) {
// With /u or /v, character class needs to be desugared, so it
// must be a standalone term instead of being part of a RegExpText.
AddTerm(cr);
} else {
AddAtom(cr);
}
}
void RegExpTextBuilder::AddClassRangesForDesugaring(base::uc32 c) {
AddTerm(zone()->New<RegExpClassRanges>(
zone(), CharacterRange::List(zone(), CharacterRange::Singleton(c))));
}
void RegExpTextBuilder::AddAtom(RegExpTree* atom) {
DCHECK(atom->IsTextElement());
FlushCharacters();
text_.emplace_back(atom);
}
void RegExpTextBuilder::AddTerm(RegExpTree* term) {
DCHECK(term->IsTextElement());
FlushText();
terms_->emplace_back(term);
}
bool RegExpTextBuilder::NeedsDesugaringForUnicode(RegExpClassRanges* cc) {
if (!IsUnicodeMode()) return false;
// TODO(yangguo): we could be smarter than this. Case-insensitivity does not
// necessarily mean that we need to desugar. It's probably nicer to have a
// separate pass to figure out unicode desugarings.
if (ignore_case()) return true;
ZoneList<CharacterRange>* ranges = cc->ranges(zone());
CharacterRange::Canonicalize(ranges);
if (cc->is_negated()) {
ZoneList<CharacterRange>* negated_ranges =
zone()->New<ZoneList<CharacterRange>>(ranges->length(), zone());
CharacterRange::Negate(ranges, negated_ranges, zone());
ranges = negated_ranges;
}
for (int i = ranges->length() - 1; i >= 0; i--) {
base::uc32 from = ranges->at(i).from();
base::uc32 to = ranges->at(i).to();
// Check for non-BMP characters.
if (to >= kNonBmpStart) return true;
// Check for lone surrogates.
if (from <= kTrailSurrogateEnd && to >= kLeadSurrogateStart) return true;
}
return false;
}
// We only use this for characters made of surrogate pairs. All other
// characters outside of character classes are made case independent in the
// code generation.
bool RegExpTextBuilder::NeedsDesugaringForIgnoreCase(base::uc32 c) {
#ifdef V8_INTL_SUPPORT
if (IsUnicodeMode() && ignore_case()) {
icu::UnicodeSet set(c, c);
set.closeOver(USET_CASE_INSENSITIVE);
set.removeAllStrings();
return set.size() > 1;
}
// In the case where ICU is not included, we act as if the unicode flag is
// not set, and do not desugar.
#endif // V8_INTL_SUPPORT
return false;
}
RegExpTree* RegExpTextBuilder::PopLastAtom() {
FlushPendingSurrogate();
RegExpTree* atom;
if (characters_ != nullptr) {
base::Vector<const base::uc16> char_vector = characters_->ToConstVector();
int num_chars = char_vector.length();
if (num_chars > 1) {
base::Vector<const base::uc16> prefix =
char_vector.SubVector(0, num_chars - 1);
text_.emplace_back(zone()->New<RegExpAtom>(prefix));
char_vector = char_vector.SubVector(num_chars - 1, num_chars);
}
characters_ = nullptr;
atom = zone()->New<RegExpAtom>(char_vector);
return atom;
} else if (!text_.empty()) {
atom = text_.back();
text_.pop_back();
return atom;
}
return nullptr;
}
RegExpTree* RegExpTextBuilder::ToRegExp() {
FlushText();
size_t number_of_terms = terms_->size();
if (number_of_terms == 0) return zone()->New<RegExpEmpty>();
if (number_of_terms == 1) return terms_->back();
return zone()->New<RegExpAlternative>(zone()->New<ZoneList<RegExpTree*>>(
base::VectorOf(terms_->begin(), terms_->size()), zone()));
}
// Accumulates RegExp atoms and assertions into lists of terms and alternatives.
class RegExpBuilder {
public:
RegExpBuilder(Zone* zone, RegExpFlags flags)
: zone_(zone),
flags_(flags),
terms_(zone),
alternatives_(zone),
text_builder_(RegExpTextBuilder{zone, &terms_, flags}) {}
void AddCharacter(base::uc16 character);
void AddUnicodeCharacter(base::uc32 character);
void AddEscapedUnicodeCharacter(base::uc32 character);
// "Adds" an empty expression. Does nothing except consume a
// following quantifier
void AddEmpty();
void AddClassRanges(RegExpClassRanges* cc);
void AddAtom(RegExpTree* tree);
void AddTerm(RegExpTree* tree);
void AddAssertion(RegExpTree* tree);
void NewAlternative(); // '|'
bool AddQuantifierToAtom(int min, int max, int index,
RegExpQuantifier::QuantifierType type);
void FlushText();
RegExpTree* ToRegExp();
RegExpFlags flags() const { return flags_; }
bool ignore_case() const { return IsIgnoreCase(flags_); }
bool multiline() const { return IsMultiline(flags_); }
bool dotall() const { return IsDotAll(flags_); }
private:
void FlushTerms();
bool IsUnicodeMode() const {
// Either /v or /u enable UnicodeMode
// https://tc39.es/ecma262/#sec-parsepattern
return IsUnicode(flags_) || IsUnicodeSets(flags_);
}
Zone* zone() const { return zone_; }
RegExpTextBuilder& text_builder() { return text_builder_; }
Zone* const zone_;
bool pending_empty_ = false;
const RegExpFlags flags_;
using SmallRegExpTreeVector = SmallZoneVector<RegExpTree*, 8>;
SmallRegExpTreeVector terms_;
SmallRegExpTreeVector alternatives_;
RegExpTextBuilder text_builder_;
};
enum SubexpressionType {
INITIAL,
CAPTURE, // All positive values represent captures.
POSITIVE_LOOKAROUND,
NEGATIVE_LOOKAROUND,
GROUPING
};
class RegExpParserState : public ZoneObject {
public:
// Push a state on the stack.
RegExpParserState(RegExpParserState* previous_state,
SubexpressionType group_type,
RegExpLookaround::Type lookaround_type,
int disjunction_capture_index,
const ZoneVector<base::uc16>* capture_name,
RegExpFlags flags, Zone* zone)
: previous_state_(previous_state),
builder_(zone, flags),
group_type_(group_type),
lookaround_type_(lookaround_type),
disjunction_capture_index_(disjunction_capture_index),
capture_name_(capture_name),
non_participating_capture_group_intervals_(zone) {
if (previous_state != nullptr) {
non_participating_capture_group_intervals_.insert(
non_participating_capture_group_intervals_.begin(),
previous_state->non_participating_capture_group_intervals_);
}
}
using IntervalVector = SmallZoneVector<Interval, 1>;
// Parser state of containing expression, if any.
RegExpParserState* previous_state() const { return previous_state_; }
bool IsSubexpression() { return previous_state_ != nullptr; }
// RegExpBuilder building this regexp's AST.
RegExpBuilder* builder() { return &builder_; }
// Type of regexp being parsed (parenthesized group or entire regexp).
SubexpressionType group_type() const { return group_type_; }
// Lookahead or Lookbehind.
RegExpLookaround::Type lookaround_type() const { return lookaround_type_; }
// Index in captures array of first capture in this sub-expression, if any.
// Also the capture index of this sub-expression itself, if group_type
// is CAPTURE.
int capture_index() const { return disjunction_capture_index_; }
// The name of the current sub-expression, if group_type is CAPTURE. Only
// used for named captures.
const ZoneVector<base::uc16>* capture_name() const { return capture_name_; }
const IntervalVector& non_participating_capture_group_intervals() const {
return non_participating_capture_group_intervals_;
}
bool IsNamedCapture() const { return capture_name_ != nullptr; }
// Check whether the parser is inside a capture group with the given index.
bool IsInsideCaptureGroup(int index) const {
for (const RegExpParserState* s = this; s != nullptr;
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;
}
// Check whether the parser is inside a capture group with the given name.
bool IsInsideCaptureGroup(const ZoneVector<base::uc16>* name) const {
DCHECK_NOT_NULL(name);
for (const RegExpParserState* s = this; s != nullptr;
s = s->previous_state()) {
if (s->capture_name() == nullptr) continue;
if (*s->capture_name() == *name) return true;
}
return false;
}
void NewAlternative(int captures_started) {
// Nothing to do if there were no new captures started before the
// alternative.
if (capture_index() == captures_started) return;
// +1 to create a closed interval (capture_index() is exclusive).
int from = capture_index() + 1;
int to = captures_started;
DCHECK_LE(from, to);
// Extend the last interval if we increase its range by exactly 1.
if (!non_participating_capture_group_intervals().empty() &&
non_participating_capture_group_intervals().back().to() + 1 == to) {
Interval& interval = non_participating_capture_group_intervals_.back();
DCHECK(!interval.is_empty());
DCHECK_GE(from, interval.from());
interval = interval.Union({from, to});
} else {
non_participating_capture_group_intervals_.push_back({from, to});
}
}
private:
// Linked list implementation of stack of states.
RegExpParserState* const previous_state_;
// Builder for the stored disjunction.
RegExpBuilder builder_;
// Stored disjunction type (capture, look-ahead or grouping), if any.
const SubexpressionType group_type_;
// Stored read direction.
const RegExpLookaround::Type lookaround_type_;
// Stored disjunction's capture index (if any).
const int disjunction_capture_index_;
// Stored capture name (if any).
const ZoneVector<base::uc16>* const capture_name_;
// List of Intervals of (named) capture indices [from, to] that are not
// participating in the current state (i.e. they cannot match).
// Capture indices are not participating if they were created in a different
// alternative.
IntervalVector non_participating_capture_group_intervals_;
};
template <class CharT>
class RegExpParserImpl final {
private:
RegExpParserImpl(const CharT* input, int input_length, RegExpFlags flags,
uintptr_t stack_limit, Zone* zone,
const DisallowGarbageCollection& no_gc);
bool Parse(RegExpCompileData* result);
RegExpTree* ParsePattern();
RegExpTree* ParseDisjunction();
RegExpTree* ParseGroup();
// Parses a {...,...} quantifier and stores the range in the given
// out parameters.
bool ParseIntervalQuantifier(int* min_out, int* max_out);
// Checks whether the following is a length-digit hexadecimal number,
// and sets the value if it is.
bool ParseHexEscape(int length, base::uc32* value);
bool ParseUnicodeEscape(base::uc32* value);
bool ParseUnlimitedLengthHexNumber(int max_value, base::uc32* value);
bool ParsePropertyClassName(ZoneVector<char>* name_1,
ZoneVector<char>* name_2);
bool AddPropertyClassRange(ZoneList<CharacterRange>* add_to_range,
CharacterClassStrings* add_to_strings, bool negate,
const ZoneVector<char>& name_1,
const ZoneVector<char>& name_2);
RegExpTree* ParseClassRanges(ZoneList<CharacterRange>* ranges,
bool add_unicode_case_equivalents);
// Parse inside a class. Either add escaped class to the range, or return
// false and pass parsed single character through |char_out|.
void ParseClassEscape(ZoneList<CharacterRange>* ranges, Zone* zone,
bool add_unicode_case_equivalents, base::uc32* char_out,
bool* is_class_escape);
// Returns true iff parsing was successful.
bool TryParseCharacterClassEscape(base::uc32 next,
InClassEscapeState in_class_escape_state,
ZoneList<CharacterRange>* ranges,
CharacterClassStrings* strings, Zone* zone,
bool add_unicode_case_equivalents);
RegExpTree* ParseClassStringDisjunction(ZoneList<CharacterRange>* ranges,
CharacterClassStrings* strings);
RegExpTree* ParseClassSetOperand(const RegExpBuilder* builder,
ClassSetOperandType* type_out);
RegExpTree* ParseClassSetOperand(const RegExpBuilder* builder,
ClassSetOperandType* type_out,
ZoneList<CharacterRange>* ranges,
CharacterClassStrings* strings,
base::uc32* character);
base::uc32 ParseClassSetCharacter();
// Parses and returns a single escaped character.
base::uc32 ParseCharacterEscape(InClassEscapeState in_class_escape_state,
bool* is_escaped_unicode_character);
void AddMaybeSimpleCaseFoldedRange(ZoneList<CharacterRange>* ranges,
CharacterRange new_range);
RegExpTree* ParseClassUnion(const RegExpBuilder* builder, bool is_negated,
RegExpTree* first_operand,
ClassSetOperandType first_operand_type,
ZoneList<CharacterRange>* ranges,
CharacterClassStrings* strings,
base::uc32 first_character);
RegExpTree* ParseClassIntersection(const RegExpBuilder* builder,
bool is_negated, RegExpTree* first_operand,
ClassSetOperandType first_operand_type);
RegExpTree* ParseClassSubtraction(const RegExpBuilder* builder,
bool is_negated, RegExpTree* first_operand,
ClassSetOperandType first_operand_type);
RegExpTree* ParseCharacterClass(const RegExpBuilder* state);
base::uc32 ParseOctalLiteral();
// Tries to parse the input as a back reference. If successful it
// stores the result in the output parameter and returns true. If
// it fails it will push back the characters read so the same characters
// can be reparsed.
bool ParseBackReferenceIndex(int* index_out);
RegExpTree* ReportError(RegExpError error);
void Advance();
void Advance(int dist);
void RewindByOneCodepoint(); // Rewinds to before the previous Advance().
void Reset(int pos);
// Reports whether the pattern might be used as a literal search string.
// Only use if the result of the parse is a single atom node.
bool simple() const { return simple_; }
bool contains_anchor() const { return contains_anchor_; }
void set_contains_anchor() { contains_anchor_ = true; }
int captures_started() const { return captures_started_; }
int position() const {
const bool current_is_surrogate =
current() != kEndMarker &&
current() > unibrow::Utf16::kMaxNonSurrogateCharCode;
const int rewind_bytes = current_is_surrogate ? 2 : 1;
return next_pos_ - rewind_bytes;
}
bool failed() const { return failed_; }
RegExpFlags flags() const { return flags_; }
bool IsUnicodeMode() const {
// Either /v or /u enable UnicodeMode
// https://tc39.es/ecma262/#sec-parsepattern
return IsUnicode(flags()) || IsUnicodeSets(flags()) || force_unicode_;
}
bool unicode_sets() const { return IsUnicodeSets(flags()); }
bool ignore_case() const { return IsIgnoreCase(flags()); }
static bool IsSyntaxCharacterOrSlash(base::uc32 c);
static bool IsClassSetSyntaxCharacter(base::uc32 c);
static bool IsClassSetReservedPunctuator(base::uc32 c);
bool IsClassSetReservedDoublePunctuator(base::uc32 c);
static const base::uc32 kEndMarker = (1 << 21);
private:
// Return the 1-indexed RegExpCapture object, allocate if necessary.
RegExpCapture* GetCapture(int index);
// Creates a new named capture at the specified index. Must be called exactly
// once for each named capture. Fails if a capture with the same name is
// encountered.
bool CreateNamedCaptureAtIndex(const RegExpParserState* state, int index);
// Parses the name of a capture group (?<name>pattern). The name must adhere
// to IdentifierName in the ECMAScript standard.
const ZoneVector<base::uc16>* ParseCaptureGroupName();
bool ParseNamedBackReference(RegExpBuilder* builder,
RegExpParserState* state);
RegExpParserState* ParseOpenParenthesis(RegExpParserState* state);
// After the initial parsing pass, patch corresponding RegExpCapture objects
// into all RegExpBackReferences. This is done after initial parsing in order
// to avoid complicating cases in which references comes before the capture.
void PatchNamedBackReferences();
ZoneVector<RegExpCapture*>* GetNamedCaptures();
// Returns true iff the pattern contains named captures. May call
// ScanForCaptures to look ahead at the remaining pattern.
bool HasNamedCaptures(InClassEscapeState in_class_escape_state);
Zone* zone() const { return zone_; }
base::uc32 current() const { return current_; }
bool has_more() const { return has_more_; }
bool has_next() const { return next_pos_ < input_length(); }
base::uc32 Next();
template <bool update_position>
base::uc32 ReadNext();
CharT InputAt(int index) const {
DCHECK(0 <= index && index < input_length());
return input_[index];
}
int input_length() const { return input_length_; }
void ScanForCaptures(InClassEscapeState in_class_escape_state);
struct RegExpCaptureNameLess {
bool operator()(const RegExpCapture* lhs, const RegExpCapture* rhs) const {
DCHECK_NOT_NULL(lhs);
DCHECK_NOT_NULL(rhs);
return *lhs->name() < *rhs->name();
}
};
class ForceUnicodeScope final {
public:
explicit ForceUnicodeScope(RegExpParserImpl<CharT>* parser)
: parser_(parser) {
DCHECK(!parser_->force_unicode_);
parser_->force_unicode_ = true;
}
~ForceUnicodeScope() {
DCHECK(parser_->force_unicode_);
parser_->force_unicode_ = false;
}
private:
RegExpParserImpl<CharT>* const parser_;
};
const DisallowGarbageCollection no_gc_;
Zone* const zone_;
RegExpError error_ = RegExpError::kNone;
int error_pos_ = 0;
ZoneList<RegExpCapture*>* captures_;
// Maps capture names to a list of capture indices with this name.
ZoneMap<RegExpCapture*, ZoneList<int>*, RegExpCaptureNameLess>*
named_captures_;
ZoneList<RegExpBackReference*>* named_back_references_;
const CharT* const input_;
const int input_length_;
base::uc32 current_;
RegExpFlags flags_;
bool force_unicode_ = false; // Force parser to act as if unicode were set.
int next_pos_;
int captures_started_;
int capture_count_; // Only valid after we have scanned for captures.
int quantifier_count_;
int lookaround_count_; // Only valid after we have scanned for lookbehinds.
bool has_more_;
bool simple_;
bool contains_anchor_;
bool is_scanned_for_captures_;
bool has_named_captures_; // Only valid after we have scanned for captures.
bool failed_;
const uintptr_t stack_limit_;
friend class v8::internal::RegExpParser;
};
template <class CharT>
RegExpParserImpl<CharT>::RegExpParserImpl(
const CharT* input, int input_length, RegExpFlags flags,
uintptr_t stack_limit, Zone* zone, const DisallowGarbageCollection& no_gc)
: zone_(zone),
captures_(nullptr),
named_captures_(nullptr),
named_back_references_(nullptr),
input_(input),
input_length_(input_length),
current_(kEndMarker),
flags_(flags),
next_pos_(0),
captures_started_(0),
capture_count_(0),
quantifier_count_(0),
lookaround_count_(0),
has_more_(true),
simple_(false),
contains_anchor_(false),
is_scanned_for_captures_(false),
has_named_captures_(false),
failed_(false),
stack_limit_(stack_limit) {
Advance();
}
template <>
template <bool update_position>
inline base::uc32 RegExpParserImpl<uint8_t>::ReadNext() {
int position = next_pos_;
base::uc16 c0 = InputAt(position);
position++;
DCHECK(!unibrow::Utf16::IsLeadSurrogate(c0));
if (update_position) next_pos_ = position;
return c0;
}
template <>
template <bool update_position>
inline base::uc32 RegExpParserImpl<base::uc16>::ReadNext() {
int position = next_pos_;
base::uc16 c0 = InputAt(position);
base::uc32 result = c0;
position++;
// Read the whole surrogate pair in case of unicode mode, if possible.
if (IsUnicodeMode() && position < input_length() &&
unibrow::Utf16::IsLeadSurrogate(c0)) {
base::uc16 c1 = InputAt(position);
if (unibrow::Utf16::IsTrailSurrogate(c1)) {
result = unibrow::Utf16::CombineSurrogatePair(c0, c1);
position++;
}
}
if (update_position) next_pos_ = position;
return result;
}
template <class CharT>
base::uc32 RegExpParserImpl<CharT>::Next() {
if (has_next()) {
return ReadNext<false>();
} else {
return kEndMarker;
}
}
template <class CharT>
void RegExpParserImpl<CharT>::Advance() {
if (has_next()) {
if (GetCurrentStackPosition() < stack_limit_) {
if (v8_flags.correctness_fuzzer_suppressions) {
FATAL("Aborting on stack overflow");
}
ReportError(RegExpError::kStackOverflow);
} else {
current_ = ReadNext<true>();
}
} 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_ = input_length() + 1;
has_more_ = false;
}
}
template <class CharT>
void RegExpParserImpl<CharT>::RewindByOneCodepoint() {
if (!has_more()) return;
// Rewinds by one code point, i.e.: two code units if `current` is outside
// the basic multilingual plane (= composed of a lead and trail surrogate),
// or one code unit otherwise.
const int rewind_by =
current() > unibrow::Utf16::kMaxNonSurrogateCharCode ? -2 : -1;
Advance(rewind_by); // Undo the last Advance.
}
template <class CharT>
void RegExpParserImpl<CharT>::Reset(int pos) {
next_pos_ = pos;
has_more_ = (pos < input_length());
Advance();
}
template <class CharT>
void RegExpParserImpl<CharT>::Advance(int dist) {
next_pos_ += dist - 1;
Advance();
}
// static
template <class CharT>
bool RegExpParserImpl<CharT>::IsSyntaxCharacterOrSlash(base::uc32 c) {
switch (c) {
case '^':
case '$':
case '\\':
case '.':
case '*':
case '+':
case '?':
case '(':
case ')':
case '[':
case ']':
case '{':
case '}':
case '|':
case '/':
return true;
default:
break;
}
return false;
}
// static
template <class CharT>
bool RegExpParserImpl<CharT>::IsClassSetSyntaxCharacter(base::uc32 c) {
switch (c) {
case '(':
case ')':
case '[':
case ']':
case '{':
case '}':
case '/':
case '-':
case '\\':
case '|':
return true;
default:
break;
}
return false;
}
// static
template <class CharT>
bool RegExpParserImpl<CharT>::IsClassSetReservedPunctuator(base::uc32 c) {
switch (c) {
case '&':
case '-':
case '!':
case '#':
case '%':
case ',':
case ':':
case ';':
case '<':
case '=':
case '>':
case '@':
case '`':
case '~':
return true;
default:
break;
}
return false;
}
template <class CharT>
bool RegExpParserImpl<CharT>::IsClassSetReservedDoublePunctuator(base::uc32 c) {
#define DOUBLE_PUNCTUATOR_CASE(Char) \
case Char: \
return Next() == Char
switch (c) {
DOUBLE_PUNCTUATOR_CASE('&');
DOUBLE_PUNCTUATOR_CASE('!');
DOUBLE_PUNCTUATOR_CASE('#');
DOUBLE_PUNCTUATOR_CASE('$');
DOUBLE_PUNCTUATOR_CASE('%');
DOUBLE_PUNCTUATOR_CASE('*');
DOUBLE_PUNCTUATOR_CASE('+');
DOUBLE_PUNCTUATOR_CASE(',');
DOUBLE_PUNCTUATOR_CASE('.');
DOUBLE_PUNCTUATOR_CASE(':');
DOUBLE_PUNCTUATOR_CASE(';');
DOUBLE_PUNCTUATOR_CASE('<');
DOUBLE_PUNCTUATOR_CASE('=');
DOUBLE_PUNCTUATOR_CASE('>');
DOUBLE_PUNCTUATOR_CASE('?');
DOUBLE_PUNCTUATOR_CASE('@');
DOUBLE_PUNCTUATOR_CASE('^');
DOUBLE_PUNCTUATOR_CASE('`');
DOUBLE_PUNCTUATOR_CASE('~');
default:
break;
}
#undef DOUBLE_PUNCTUATOR_CASE
return false;
}
template <class CharT>
RegExpTree* RegExpParserImpl<CharT>::ReportError(RegExpError error) {
if (failed_) return nullptr; // Do not overwrite any existing error.
failed_ = true;
error_ = error;
error_pos_ = position();
// Zip to the end to make sure no more input is read.
current_ = kEndMarker;
next_pos_ = input_length();
has_more_ = false;
return nullptr;
}
#define CHECK_FAILED /**/); \
if (failed_) return nullptr; \
((void)0
// Pattern ::
// Disjunction
template <class CharT>
RegExpTree* RegExpParserImpl<CharT>::ParsePattern() {
RegExpTree* result = ParseDisjunction(CHECK_FAILED);
PatchNamedBackReferences(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() == input_length()) {
simple_ = true;
}
return result;
}
// Disjunction ::
// Alternative
// Alternative | Disjunction
// Alternative ::
// [empty]
// Term Alternative
// Term ::
// Assertion
// Atom
// Atom Quantifier
template <class CharT>
RegExpTree* RegExpParserImpl<CharT>::ParseDisjunction() {
// Used to store current state while parsing subexpressions.
RegExpParserState initial_state(nullptr, INITIAL, RegExpLookaround::LOOKAHEAD,
0, nullptr, flags(), 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 (failed()) return nullptr; // E.g. the initial Advance failed.
if (state->IsSubexpression()) {
// Inside a parenthesized group when hitting end of input.
return ReportError(RegExpError::kUnterminatedGroup);
}
DCHECK_EQ(INITIAL, state->group_type());
// Parsing completed successfully.
return builder->ToRegExp();
case ')': {
if (!state->IsSubexpression()) {
return ReportError(RegExpError::kUnmatchedParen);
}
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) {
if (state->IsNamedCapture()) {
CreateNamedCaptureAtIndex(state, capture_index CHECK_FAILED);
}
RegExpCapture* capture = GetCapture(capture_index);
capture->set_body(body);
body = capture;
} else if (group_type == GROUPING) {
body = zone()->template New<RegExpGroup>(body, builder->flags());
} else {
DCHECK(group_type == POSITIVE_LOOKAROUND ||
group_type == NEGATIVE_LOOKAROUND);
bool is_positive = (group_type == POSITIVE_LOOKAROUND);
body = zone()->template New<RegExpLookaround>(
body, is_positive, end_capture_index - capture_index,
capture_index, state->lookaround_type(), lookaround_count_);
lookaround_count_++;
}
// Restore previous state.
state = state->previous_state();
builder = state->builder();
builder->AddAtom(body);
// For compatibility with JSC and ES3, we allow quantifiers after
// lookaheads, and break in all cases.
break;
}
case '|': {
Advance();
state->NewAlternative(captures_started());
builder->NewAlternative();
continue;
}
case '*':
case '+':
case '?':
return ReportError(RegExpError::kNothingToRepeat);
case '^': {
Advance();
builder->AddAssertion(zone()->template New<RegExpAssertion>(
builder->multiline() ? RegExpAssertion::Type::START_OF_LINE
: RegExpAssertion::Type::START_OF_INPUT));
set_contains_anchor();
continue;
}
case '$': {
Advance();
RegExpAssertion::Type assertion_type =
builder->multiline() ? RegExpAssertion::Type::END_OF_LINE
: RegExpAssertion::Type::END_OF_INPUT;
builder->AddAssertion(
zone()->template New<RegExpAssertion>(assertion_type));
continue;
}
case '.': {
Advance();
ZoneList<CharacterRange>* ranges =
zone()->template New<ZoneList<CharacterRange>>(2, zone());
if (builder->dotall()) {
// Everything.
CharacterRange::AddClassEscape(StandardCharacterSet::kEverything,
ranges, false, zone());
} else {
// Everything except \x0A, \x0D, \u2028 and \u2029.
CharacterRange::AddClassEscape(
StandardCharacterSet::kNotLineTerminator, ranges, false, zone());
}
RegExpClassRanges* cc =
zone()->template New<RegExpClassRanges>(zone(), ranges);
builder->AddClassRanges(cc);
break;
}
case '(': {
state = ParseOpenParenthesis(state CHECK_FAILED);
builder = state->builder();
flags_ = builder->flags();
continue;
}
case '[': {
RegExpTree* cc = ParseCharacterClass(builder CHECK_FAILED);
if (cc->IsClassRanges()) {
builder->AddClassRanges(cc->AsClassRanges());
} else {
DCHECK(cc->IsClassSetExpression());
builder->AddTerm(cc);
}
break;
}
// Atom ::
// \ AtomEscape
case '\\':
switch (Next()) {
case kEndMarker:
return ReportError(RegExpError::kEscapeAtEndOfPattern);
// AtomEscape ::
// [+UnicodeMode] DecimalEscape
// [~UnicodeMode] DecimalEscape but only if the CapturingGroupNumber
// of DecimalEscape is ≤ NcapturingParens
// CharacterEscape (some cases of this mixed in too)
//
// TODO(jgruber): It may make sense to disentangle all the different
// cases and make the structure mirror the spec, e.g. for AtomEscape:
//
// if (TryParseDecimalEscape(...)) return;
// if (TryParseCharacterClassEscape(...)) return;
// if (TryParseCharacterEscape(...)) return;
// if (TryParseGroupName(...)) return;
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9': {
int index = 0;
const bool is_backref =
ParseBackReferenceIndex(&index CHECK_FAILED);
if (is_backref) {
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 =
zone()->template New<RegExpBackReference>(capture, zone());
builder->AddAtom(atom);
}
break;
}
// With /u and /v, no identity escapes except for syntax characters
// are allowed. Otherwise, all identity escapes are allowed.
if (IsUnicodeMode()) {
return ReportError(RegExpError::kInvalidEscape);
}
base::uc32 first_digit = Next();
if (first_digit == '8' || first_digit == '9') {
builder->AddCharacter(first_digit);
Advance(2);
break;
}
[[fallthrough]];
}
case '0': {
Advance();
if (IsUnicodeMode() && Next() >= '0' && Next() <= '9') {
// Decimal escape with leading 0 are not parsed as octal.
return ReportError(RegExpError::kInvalidDecimalEscape);
}
base::uc32 octal = ParseOctalLiteral();
builder->AddCharacter(octal);
break;
}
case 'b':
Advance(2);
builder->AddAssertion(zone()->template New<RegExpAssertion>(
RegExpAssertion::Type::BOUNDARY));
continue;
case 'B':
Advance(2);
builder->AddAssertion(zone()->template New<RegExpAssertion>(
RegExpAssertion::Type::NON_BOUNDARY));
continue;
// AtomEscape ::
// CharacterClassEscape
case 'd':
case 'D':
case 's':
case 'S':
case 'w':
case 'W': {
base::uc32 next = Next();
ZoneList<CharacterRange>* ranges =
zone()->template New<ZoneList<CharacterRange>>(2, zone());
bool add_unicode_case_equivalents =
IsUnicodeMode() && ignore_case();
bool parsed_character_class_escape = TryParseCharacterClassEscape(
next, InClassEscapeState::kNotInClass, ranges, nullptr, zone(),
add_unicode_case_equivalents CHECK_FAILED);
if (parsed_character_class_escape) {
RegExpClassRanges* cc =
zone()->template New<RegExpClassRanges>(zone(), ranges);
builder->AddClassRanges(cc);
} else {
CHECK(!IsUnicodeMode());
Advance(2);
builder->AddCharacter(next); // IdentityEscape.
}
break;
}
case 'p':
case 'P': {
base::uc32 next = Next();
ZoneList<CharacterRange>* ranges =
zone()->template New<ZoneList<CharacterRange>>(2, zone());
CharacterClassStrings* strings = nullptr;
if (unicode_sets()) {
strings = zone()->template New<CharacterClassStrings>(zone());
}
bool add_unicode_case_equivalents = ignore_case();
bool parsed_character_class_escape = TryParseCharacterClassEscape(
next, InClassEscapeState::kNotInClass, ranges, strings, zone(),
add_unicode_case_equivalents CHECK_FAILED);
if (parsed_character_class_escape) {
if (unicode_sets()) {
RegExpClassSetOperand* op =
zone()->template New<RegExpClassSetOperand>(ranges,
strings);
builder->AddTerm(op);
} else {
RegExpClassRanges* cc =
zone()->template New<RegExpClassRanges>(zone(), ranges);
builder->AddClassRanges(cc);
}
} else {
CHECK(!IsUnicodeMode());
Advance(2);
builder->AddCharacter(next); // IdentityEscape.
}
break;
}
// AtomEscape ::
// k GroupName
case 'k': {
// Either an identity escape or a named back-reference. The two
// interpretations are mutually exclusive: '\k' is interpreted as
// an identity escape for non-Unicode patterns without named
// capture groups, and as the beginning of a named back-reference
// in all other cases.
const bool has_named_captures =
HasNamedCaptures(InClassEscapeState::kNotInClass CHECK_FAILED);
if (IsUnicodeMode() || has_named_captures) {
Advance(2);
ParseNamedBackReference(builder, state CHECK_FAILED);
break;
}
}
[[fallthrough]];
// AtomEscape ::
// CharacterEscape
default: {
bool is_escaped_unicode_character = false;
base::uc32 c = ParseCharacterEscape(
InClassEscapeState::kNotInClass,
&is_escaped_unicode_character CHECK_FAILED);
if (is_escaped_unicode_character) {
builder->AddEscapedUnicodeCharacter(c);
} else {
builder->AddCharacter(c);
}
break;
}
}
break;
case '{': {
int dummy;
bool parsed = ParseIntervalQuantifier(&dummy, &dummy CHECK_FAILED);
if (parsed) return ReportError(RegExpError::kNothingToRepeat);
[[fallthrough]];
}
case '}':
case ']':
if (IsUnicodeMode()) {
return ReportError(RegExpError::kLoneQuantifierBrackets);
}
[[fallthrough]];
default:
builder->AddUnicodeCharacter(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) {
return ReportError(RegExpError::kRangeOutOfOrder);
}
break;
} else if (IsUnicodeMode()) {
// Incomplete quantifiers are not allowed.
return ReportError(RegExpError::kIncompleteQuantifier);
}
continue;
default:
continue;
}
RegExpQuantifier::QuantifierType quantifier_type = RegExpQuantifier::GREEDY;
if (current() == '?') {
quantifier_type = RegExpQuantifier::NON_GREEDY;
Advance();
} else if (v8_flags.regexp_possessive_quantifier && current() == '+') {
// v8_flags.regexp_possessive_quantifier is a debug-only flag.
quantifier_type = RegExpQuantifier::POSSESSIVE;
Advance();
}
if (!builder->AddQuantifierToAtom(min, max, quantifier_count_,
quantifier_type)) {
return ReportError(RegExpError::kInvalidQuantifier);
}
++quantifier_count_;
}
}
template <class CharT>
RegExpParserState* RegExpParserImpl<CharT>::ParseOpenParenthesis(
RegExpParserState* state) {
RegExpLookaround::Type lookaround_type = state->lookaround_type();
bool is_named_capture = false;
const ZoneVector<base::uc16>* capture_name = nullptr;
SubexpressionType subexpr_type = CAPTURE;
RegExpFlags flags = state->builder()->flags();
bool parsing_modifiers = false;
bool modifiers_polarity = true;
RegExpFlags modifiers;
Advance();
if (current() == '?') {
do {
base::uc32 next = Next();
switch (next) {
case '-':
if (!v8_flags.js_regexp_modifiers) {
ReportError(RegExpError::kInvalidGroup);
return nullptr;
}
Advance();
parsing_modifiers = true;
if (modifiers_polarity == false) {
ReportError(RegExpError::kMultipleFlagDashes);
return nullptr;
}
modifiers_polarity = false;
break;
case 'm':
case 'i':
case 's': {
if (!v8_flags.js_regexp_modifiers) {
ReportError(RegExpError::kInvalidGroup);
return nullptr;
}
Advance();
parsing_modifiers = true;
RegExpFlag flag = TryRegExpFlagFromChar(next).value();
if ((modifiers & flag) != 0) {
ReportError(RegExpError::kRepeatedFlag);
return nullptr;
}
modifiers |= flag;
flags.set(flag, modifiers_polarity);
break;
}
case ':':
Advance(2);
parsing_modifiers = false;
subexpr_type = GROUPING;
break;
case '=':
Advance(2);
if (parsing_modifiers) {
DCHECK(v8_flags.js_regexp_modifiers);
ReportError(RegExpError::kInvalidGroup);
return nullptr;
}
lookaround_type = RegExpLookaround::LOOKAHEAD;
subexpr_type = POSITIVE_LOOKAROUND;
break;
case '!':
Advance(2);
if (parsing_modifiers) {
DCHECK(v8_flags.js_regexp_modifiers);
ReportError(RegExpError::kInvalidGroup);
return nullptr;
}
lookaround_type = RegExpLookaround::LOOKAHEAD;
subexpr_type = NEGATIVE_LOOKAROUND;
break;
case '<':
Advance();
if (parsing_modifiers) {
DCHECK(v8_flags.js_regexp_modifiers);
ReportError(RegExpError::kInvalidGroup);
return nullptr;
}
if (Next() == '=') {
Advance(2);
lookaround_type = RegExpLookaround::LOOKBEHIND;
subexpr_type = POSITIVE_LOOKAROUND;
break;
} else if (Next() == '!') {
Advance(2);
lookaround_type = RegExpLookaround::LOOKBEHIND;
subexpr_type = NEGATIVE_LOOKAROUND;
break;
}
is_named_capture = true;
has_named_captures_ = true;
Advance();
break;
default:
ReportError(RegExpError::kInvalidGroup);
return nullptr;
}
} while (parsing_modifiers);
}
if (modifiers_polarity == false) {
// We encountered a dash.
if (modifiers == 0) {
ReportError(RegExpError::kInvalidFlagGroup);
return nullptr;
}
}
if (subexpr_type == CAPTURE) {
if (captures_started_ >= RegExpMacroAssembler::kMaxCaptures) {
ReportError(RegExpError::kTooManyCaptures);
return nullptr;
}
captures_started_++;
if (is_named_capture) {
capture_name = ParseCaptureGroupName(CHECK_FAILED);
}
}
// Store current state and begin new disjunction parsing.
return zone()->template New<RegExpParserState>(
state, subexpr_type, lookaround_type, captures_started_, capture_name,
flags, zone());
}
// 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.
//
// Important: The scanner has to be in a consistent state when calling
// ScanForCaptures, e.g. not in the middle of an escape sequence '\[' or while
// parsing a nested class.
template <class CharT>
void RegExpParserImpl<CharT>::ScanForCaptures(
InClassEscapeState in_class_escape_state) {
DCHECK(!is_scanned_for_captures_);
const int saved_position = position();
// Start with captures started previous to current position
int capture_count = captures_started();
// When we start inside a character class, skip everything inside the class.
if (in_class_escape_state == InClassEscapeState::kInClass) {
// \k is always invalid within a class in unicode mode, thus we should never
// call ScanForCaptures within a class.
DCHECK(!IsUnicodeMode());
int c;
while ((c = current()) != kEndMarker) {
Advance();
if (c == '\\') {
Advance();
} else {
if (c == ']') break;
}
}
}
// Add count of captures after this position.
int n;
while ((n = current()) != kEndMarker) {
Advance();
switch (n) {
case '\\':
Advance();
break;
case '[': {
int class_nest_level = 0;
int c;
while ((c = current()) != kEndMarker) {
Advance();
if (c == '\\') {
Advance();
} else if (c == '[') {
// With /v, '[' inside a class is treated as a nested class.
// Without /v, '[' is a normal character.
if (unicode_sets()) class_nest_level++;
} else if (c == ']') {
if (class_nest_level == 0) break;
class_nest_level--;
}
}
break;
}
case '(':
if (current() == '?') {
// At this point we could be in
// * a non-capturing group '(:',
// * a lookbehind assertion '(?<=' '(?<!'
// * or a named capture '(?<'.
//
// Of these, only named captures are capturing groups.
Advance();
if (current() != '<') break;
Advance();
if (current() == '=' || current() == '!') break;
// Found a possible named capture. It could turn out to be a syntax
// error (e.g. an unterminated or invalid name), but that distinction
// does not matter for our purposes.
has_named_captures_ = true;
}
capture_count++;
break;
}
}
capture_count_ = capture_count;
is_scanned_for_captures_ = true;
Reset(saved_position);
}
template <class CharT>
bool RegExpParserImpl<CharT>::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) {
base::uc32 c = current();
if (IsDecimalDigit(c)) {
value = 10 * value + (c - '0');
if (value > RegExpMacroAssembler::kMaxCaptures) {
Reset(start);
return false;
}
Advance();
} else {
break;
}
}
if (value > captures_started()) {
if (!is_scanned_for_captures_) {
ScanForCaptures(InClassEscapeState::kNotInClass);
}
if (value > capture_count_) {
Reset(start);
return false;
}
}
*index_out = value;
return true;
}
namespace {
void push_code_unit(ZoneVector<base::uc16>* v, uint32_t code_unit) {
if (code_unit <= unibrow::Utf16::kMaxNonSurrogateCharCode) {
v->push_back(code_unit);
} else {
v->push_back(unibrow::Utf16::LeadSurrogate(code_unit));
v->push_back(unibrow::Utf16::TrailSurrogate(code_unit));
}
}
} // namespace
template <class CharT>
const ZoneVector<base::uc16>* RegExpParserImpl<CharT>::ParseCaptureGroupName() {
// Due to special Advance requirements (see the next comment), rewind by one
// such that names starting with a surrogate pair are parsed correctly for
// patterns where the unicode flag is unset.
//
// Note that we use this odd pattern of rewinding the last advance in order
// to adhere to the common parser behavior of expecting `current` to point at
// the first candidate character for a function (e.g. when entering ParseFoo,
// `current` should point at the first character of Foo).
RewindByOneCodepoint();
ZoneVector<base::uc16>* name =
zone()->template New<ZoneVector<base::uc16>>(zone());
{
// Advance behavior inside this function is tricky since
// RegExpIdentifierName explicitly enables unicode (in spec terms, sets +U)
// and thus allows surrogate pairs and \u{}-style escapes even in
// non-unicode patterns. Therefore Advance within the capture group name
// has to force-enable unicode, and outside the name revert to default
// behavior.
ForceUnicodeScope force_unicode(this);
bool at_start = true;
while (true) {
Advance();
base::uc32 c = current();
// Convert unicode escapes.
if (c == '\\' && Next() == 'u') {
Advance(2);
if (!ParseUnicodeEscape(&c)) {
ReportError(RegExpError::kInvalidUnicodeEscape);
return nullptr;
}
RewindByOneCodepoint();
}
// The backslash char is misclassified as both ID_Start and ID_Continue.
if (c == '\\') {
ReportError(RegExpError::kInvalidCaptureGroupName);
return nullptr;
}
if (at_start) {
if (!IsIdentifierStart(c)) {
ReportError(RegExpError::kInvalidCaptureGroupName);
return nullptr;
}
push_code_unit(name, c);
at_start = false;
} else {
if (c == '>') {
break;
} else if (IsIdentifierPart(c)) {
push_code_unit(name, c);
} else {
ReportError(RegExpError::kInvalidCaptureGroupName);
return nullptr;
}
}
}
}
// This final advance goes back into the state of pointing at the next
// relevant char, which the rest of the parser expects. See also the previous
// comments in this function.
Advance();
return name;
}
template <class CharT>
bool RegExpParserImpl<CharT>::CreateNamedCaptureAtIndex(
const RegExpParserState* state, int index) {
const ZoneVector<base::uc16>* name = state->capture_name();
const auto& non_participating_capture_group_intervals =
state->non_participating_capture_group_intervals();
DCHECK(0 < index && index <= captures_started_);
DCHECK_NOT_NULL(name);
RegExpCapture* capture = GetCapture(index);
DCHECK_NULL(capture->name());
capture->set_name(name);
if (named_captures_ == nullptr) {
named_captures_ = zone_->template New<
ZoneMap<RegExpCapture*, ZoneList<int>*, RegExpCaptureNameLess>>(zone());
} else {
// Check for duplicates and bail if we find any.
const auto& named_capture_it = named_captures_->find(capture);
if (named_capture_it != named_captures_->end()) {
if (v8_flags.js_regexp_duplicate_named_groups) {
ZoneList<int>* named_capture_indices = named_capture_it->second;
DCHECK_NOT_NULL(named_capture_indices);
DCHECK(!named_capture_indices->is_empty());
for (int named_index : *named_capture_indices) {
bool is_duplicate = true;
for (Interval interval : non_participating_capture_group_intervals) {
DCHECK(!interval.is_empty());
// We can stop as soon as we are inside one non-participating
// interval. There can't be a non-participating and participating
// interval, as intervals are never decreasing.
if (interval.Contains(named_index)) {
is_duplicate = false;
break;
}
// Intervals are ordered strictly increasing, so we can stop early
// when the current interval is past the current index.
if (named_index <= interval.from()) {
break;
}
}
if (is_duplicate) {
ReportError(RegExpError::kDuplicateCaptureGroupName);
return false;
}
}
} else {
ReportError(RegExpError::kDuplicateCaptureGroupName);
return false;
}
}
}
if (v8_flags.js_regexp_duplicate_named_groups) {
// Check for nested named captures. This is necessary to find duplicate
// named captures within the same disjunct.
RegExpParserState* parent_state = state->previous_state();
if (parent_state && parent_state->IsInsideCaptureGroup(name)) {
ReportError(RegExpError::kDuplicateCaptureGroupName);
return false;
}
}
auto entry = named_captures_->try_emplace(
capture, zone()->template New<ZoneList<int>>(1, zone()));
entry.first->second->Add(index, zone());
return true;
}
template <class CharT>
bool RegExpParserImpl<CharT>::ParseNamedBackReference(
RegExpBuilder* builder, RegExpParserState* state) {
// The parser is assumed to be on the '<' in \k<name>.
if (current() != '<') {
ReportError(RegExpError::kInvalidNamedReference);
return false;
}
Advance();
const ZoneVector<base::uc16>* name = ParseCaptureGroupName();
if (name == nullptr) {
return false;
}
if (state->IsInsideCaptureGroup(name)) {
builder->AddEmpty();
} else {
RegExpBackReference* atom =
zone()->template New<RegExpBackReference>(zone());
atom->set_name(name);
builder->AddAtom(atom);
if (named_back_references_ == nullptr) {
named_back_references_ =
zone()->template New<ZoneList<RegExpBackReference*>>(1, zone());
}
named_back_references_->Add(atom, zone());
}
return true;
}
template <class CharT>
void RegExpParserImpl<CharT>::PatchNamedBackReferences() {
if (named_back_references_ == nullptr) return;
if (named_captures_ == nullptr) {
ReportError(RegExpError::kInvalidNamedCaptureReference);
return;
}
// Look up and patch the actual capture for each named back reference.
for (int i = 0; i < named_back_references_->length(); i++) {
RegExpBackReference* ref = named_back_references_->at(i);
// Capture used to search the named_captures_ by name, index of the
// capture is never used.
static const int kInvalidIndex = 0;
RegExpCapture* search_capture =
zone()->template New<RegExpCapture>(kInvalidIndex);
DCHECK_NULL(search_capture->name());
search_capture->set_name(ref->name());
const auto& capture_it = named_captures_->find(search_capture);
if (capture_it == named_captures_->end()) {
ReportError(RegExpError::kInvalidNamedCaptureReference);
return;
}
DCHECK_IMPLIES(!v8_flags.js_regexp_duplicate_named_groups,
capture_it->second->length() == 1);
for (int index : *capture_it->second) {
ref->add_capture(GetCapture(index), zone());
}
}
}
template <class CharT>
RegExpCapture* RegExpParserImpl<CharT>::GetCapture(int index) {
// The index for the capture groups are one-based. Its index in the list is
// zero-based.
const int known_captures =
is_scanned_for_captures_ ? capture_count_ : captures_started_;
SBXCHECK(index >= 1 && index <= known_captures);
if (captures_ == nullptr) {
captures_ =
zone()->template New<ZoneList<RegExpCapture*>>(known_captures, zone());
}
while (captures_->length() < known_captures) {
captures_->Add(zone()->template New<RegExpCapture>(captures_->length() + 1),
zone());
}
return captures_->at(index - 1);
}
template <class CharT>
ZoneVector<RegExpCapture*>* RegExpParserImpl<CharT>::GetNamedCaptures() {
if (named_captures_ == nullptr) {
return nullptr;
}
DCHECK(!named_captures_->empty());
ZoneVector<RegExpCapture*>* flattened_named_captures =
zone()->template New<ZoneVector<RegExpCapture*>>(zone());
for (auto capture : *named_captures_) {
DCHECK_IMPLIES(!v8_flags.js_regexp_duplicate_named_groups,
capture.second->length() == 1);
for (int index : *capture.second) {
flattened_named_captures->push_back(GetCapture(index));
}
}
return flattened_named_captures;
}
template <class CharT>
bool RegExpParserImpl<CharT>::HasNamedCaptures(
InClassEscapeState in_class_escape_state) {
if (has_named_captures_ || is_scanned_for_captures_) {
return has_named_captures_;
}
ScanForCaptures(in_class_escape_state);
DCHECK(is_scanned_for_captures_);
return has_named_captures_;
}
// 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.
template <class CharT>
bool RegExpParserImpl<CharT>::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;
}
template <class CharT>
base::uc32 RegExpParserImpl<CharT>::ParseOctalLiteral() {
DCHECK(('0' <= current() && current() <= '7') || !has_more());
// For compatibility with some other browsers (not all), we parse
// up to three octal digits with a value below 256.
// ES#prod-annexB-LegacyOctalEscapeSequence
base::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;
}
template <class CharT>
bool RegExpParserImpl<CharT>::ParseHexEscape(int length, base::uc32* value) {
int start = position();
base::uc32 val = 0;
for (int i = 0; i < length; ++i) {
base::uc32 c = current();
int d = base::HexValue(c);
if (d < 0) {
Reset(start);
return false;
}
val = val * 16 + d;
Advance();
}
*value = val;
return true;
}
// This parses RegExpUnicodeEscapeSequence as described in ECMA262.
template <class CharT>
bool RegExpParserImpl<CharT>::ParseUnicodeEscape(base::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() == '{' && IsUnicodeMode()) {
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.
bool result = ParseHexEscape(4, value);
if (result && IsUnicodeMode() && unibrow::Utf16::IsLeadSurrogate(*value) &&
current() == '\\') {
// Attempt to read trail surrogate.
int start = position();
if (Next() == 'u') {
Advance(2);
base::uc32 trail;
if (ParseHexEscape(4, &trail) &&
unibrow::Utf16::IsTrailSurrogate(trail)) {
*value = unibrow::Utf16::CombineSurrogatePair(
static_cast<base::uc16>(*value), static_cast<base::uc16>(trail));
return true;
}
}
Reset(start);
}
return result;
}
#ifdef V8_INTL_SUPPORT
namespace {
bool IsExactPropertyAlias(const char* property_name, UProperty property) {
const char* short_name = u_getPropertyName(property, U_SHORT_PROPERTY_NAME);
if (short_name != nullptr && strcmp(property_name, short_name) == 0)
return true;
for (int i = 0;; i++) {
const char* long_name = u_getPropertyName(
property, static_cast<UPropertyNameChoice>(U_LONG_PROPERTY_NAME + i));
if (long_name == nullptr) break;
if (strcmp(property_name, long_name) == 0) return true;
}
return false;
}
bool IsExactPropertyValueAlias(const char* property_value_name,
UProperty property, int32_t property_value) {
const char* short_name =
u_getPropertyValueName(property, property_value, U_SHORT_PROPERTY_NAME);
if (short_name != nullptr && strcmp(property_value_name, short_name) == 0) {
return true;
}
for (int i = 0;; i++) {
const char* long_name = u_getPropertyValueName(
property, property_value,
static_cast<UPropertyNameChoice>(U_LONG_PROPERTY_NAME + i));
if (long_name == nullptr) break;
if (strcmp(property_value_name, long_name) == 0) return true;
}
return false;
}
void ExtractStringsFromUnicodeSet(const icu::UnicodeSet& set,
CharacterClassStrings* strings,
RegExpFlags flags, Zone* zone) {
DCHECK(set.hasStrings());
DCHECK(IsUnicodeSets(flags));
DCHECK_NOT_NULL(strings);
RegExpTextBuilder::SmallRegExpTreeVector string_storage(zone);
RegExpTextBuilder string_builder(zone, &string_storage, flags);
const bool needs_case_folding = IsIgnoreCase(flags);
icu::UnicodeSetIterator iter(set);
iter.skipToStrings();
while (iter.next()) {
const icu::UnicodeString& s = iter.getString();
const char16_t* p = s.getBuffer();
int32_t length = s.length();
ZoneList<base::uc32>* string =
zone->template New<ZoneList<base::uc32>>(length, zone);
for (int32_t i = 0; i < length;) {
UChar32 c;
U16_NEXT(p, i, length, c);
string_builder.AddUnicodeCharacter(c);
if (needs_case_folding) {
c = u_foldCase(c, U_FOLD_CASE_DEFAULT);
}
string->Add(c, zone);
}
strings->emplace(string->ToVector(), string_builder.ToRegExp());
string_storage.clear();
}
}
bool LookupPropertyValueName(UProperty property,
const char* property_value_name, bool negate,
ZoneList<CharacterRange>* result_ranges,
CharacterClassStrings* result_strings,
RegExpFlags flags, Zone* zone) {
UProperty property_for_lookup = property;
if (property_for_lookup == UCHAR_SCRIPT_EXTENSIONS) {
// For the property Script_Extensions, we have to do the property value
// name lookup as if the property is Script.
property_for_lookup = UCHAR_SCRIPT;
}
int32_t property_value =
u_getPropertyValueEnum(property_for_lookup, property_value_name);
if (property_value == UCHAR_INVALID_CODE) return false;
// We require the property name to match exactly to one of the property value
// aliases. However, u_getPropertyValueEnum uses loose matching.
if (!IsExactPropertyValueAlias(property_value_name, property_for_lookup,
property_value)) {
return false;
}
UErrorCode ec = U_ZERO_ERROR;
icu::UnicodeSet set;
set.applyIntPropertyValue(property, property_value, ec);
bool success = ec == U_ZERO_ERROR && !set.isEmpty();
if (success) {
if (set.hasStrings()) {
ExtractStringsFromUnicodeSet(set, result_strings, flags, zone);
}
const bool needs_case_folding = IsUnicodeSets(flags) && IsIgnoreCase(flags);
if (needs_case_folding) set.closeOver(USET_SIMPLE_CASE_INSENSITIVE);
set.removeAllStrings();
if (negate) set.complement();
for (int i = 0; i < set.getRangeCount(); i++) {
result_ranges->Add(
CharacterRange::Range(set.getRangeStart(i), set.getRangeEnd(i)),
zone);
}
}
return success;
}
template <size_t N>
inline bool NameEquals(const char* name, const char (&literal)[N]) {
return strncmp(name, literal, N + 1) == 0;
}
bool LookupSpecialPropertyValueName(const char* name,
ZoneList<CharacterRange>* result,
bool negate, RegExpFlags flags,
Zone* zone) {
if (NameEquals(name, "Any")) {
if (negate) {
// Leave the list of character ranges empty, since the negation of 'Any'
// is the empty set.
} else {
result->Add(CharacterRange::Everything(), zone);
}
} else if (NameEquals(name, "ASCII")) {
result->Add(negate ? CharacterRange::Range(0x80, String::kMaxCodePoint)
: CharacterRange::Range(0x0, 0x7F),
zone);
} else if (NameEquals(name, "Assigned")) {
return LookupPropertyValueName(UCHAR_GENERAL_CATEGORY, "Unassigned",
!negate, result, nullptr, flags, zone);
} else {
return false;
}
return true;
}
// Explicitly allowlist supported binary properties. The spec forbids supporting
// properties outside of this set to ensure interoperability.
bool IsSupportedBinaryProperty(UProperty property, bool unicode_sets) {
switch (property) {
case UCHAR_ALPHABETIC:
// 'Any' is not supported by ICU. See LookupSpecialPropertyValueName.
// 'ASCII' is not supported by ICU. See LookupSpecialPropertyValueName.
case UCHAR_ASCII_HEX_DIGIT:
// 'Assigned' is not supported by ICU. See LookupSpecialPropertyValueName.
case UCHAR_BIDI_CONTROL:
case UCHAR_BIDI_MIRRORED:
case UCHAR_CASE_IGNORABLE:
case UCHAR_CASED:
case UCHAR_CHANGES_WHEN_CASEFOLDED:
case UCHAR_CHANGES_WHEN_CASEMAPPED:
case UCHAR_CHANGES_WHEN_LOWERCASED:
case UCHAR_CHANGES_WHEN_NFKC_CASEFOLDED:
case UCHAR_CHANGES_WHEN_TITLECASED:
case UCHAR_CHANGES_WHEN_UPPERCASED:
case UCHAR_DASH:
case UCHAR_DEFAULT_IGNORABLE_CODE_POINT:
case UCHAR_DEPRECATED:
case UCHAR_DIACRITIC:
case UCHAR_EMOJI:
case UCHAR_EMOJI_COMPONENT:
case UCHAR_EMOJI_MODIFIER_BASE:
case UCHAR_EMOJI_MODIFIER:
case UCHAR_EMOJI_PRESENTATION:
case UCHAR_EXTENDED_PICTOGRAPHIC:
case UCHAR_EXTENDER:
case UCHAR_GRAPHEME_BASE:
case UCHAR_GRAPHEME_EXTEND:
case UCHAR_HEX_DIGIT:
case UCHAR_ID_CONTINUE:
case UCHAR_ID_START:
case UCHAR_IDEOGRAPHIC:
case UCHAR_IDS_BINARY_OPERATOR:
case UCHAR_IDS_TRINARY_OPERATOR:
case UCHAR_JOIN_CONTROL:
case UCHAR_LOGICAL_ORDER_EXCEPTION:
case UCHAR_LOWERCASE:
case UCHAR_MATH:
case UCHAR_NONCHARACTER_CODE_POINT:
case UCHAR_PATTERN_SYNTAX:
case UCHAR_PATTERN_WHITE_SPACE:
case UCHAR_QUOTATION_MARK:
case UCHAR_RADICAL:
case UCHAR_REGIONAL_INDICATOR:
case UCHAR_S_TERM:
case UCHAR_SOFT_DOTTED:
case UCHAR_TERMINAL_PUNCTUATION:
case UCHAR_UNIFIED_IDEOGRAPH:
case UCHAR_UPPERCASE:
case UCHAR_VARIATION_SELECTOR:
case UCHAR_WHITE_SPACE:
case UCHAR_XID_CONTINUE:
case UCHAR_XID_START:
return true;
case UCHAR_BASIC_EMOJI:
case UCHAR_EMOJI_KEYCAP_SEQUENCE:
case UCHAR_RGI_EMOJI_MODIFIER_SEQUENCE:
case UCHAR_RGI_EMOJI_FLAG_SEQUENCE:
case UCHAR_RGI_EMOJI_TAG_SEQUENCE:
case UCHAR_RGI_EMOJI_ZWJ_SEQUENCE:
case UCHAR_RGI_EMOJI:
return unicode_sets;
default:
break;
}
return false;
}
bool IsBinaryPropertyOfStrings(UProperty property) {
switch (property) {
case UCHAR_BASIC_EMOJI:
case UCHAR_EMOJI_KEYCAP_SEQUENCE:
case UCHAR_RGI_EMOJI_MODIFIER_SEQUENCE:
case UCHAR_RGI_EMOJI_FLAG_SEQUENCE:
case UCHAR_RGI_EMOJI_TAG_SEQUENCE:
case UCHAR_RGI_EMOJI_ZWJ_SEQUENCE:
case UCHAR_RGI_EMOJI:
return true;
default:
break;
}
return false;
}
bool IsUnicodePropertyValueCharacter(char c) {
// https://tc39.github.io/proposal-regexp-unicode-property-escapes/
//
// Note that using this to validate each parsed char is quite conservative.
// A possible alternative solution would be to only ensure the parsed
// property name/value candidate string does not contain '\0' characters and
// let ICU lookups trigger the final failure.
if ('a' <= c && c <= 'z') return true;
if ('A' <= c && c <= 'Z') return true;
if ('0' <= c && c <= '9') return true;
return (c == '_');
}
} // namespace
template <class CharT>
bool RegExpParserImpl<CharT>::ParsePropertyClassName(ZoneVector<char>* name_1,
ZoneVector<char>* name_2) {
DCHECK(name_1->empty());
DCHECK(name_2->empty());
// Parse the property class as follows:
// - In \p{name}, 'name' is interpreted
// - either as a general category property value name.
// - or as a binary property name.
// - In \p{name=value}, 'name' is interpreted as an enumerated property name,
// and 'value' is interpreted as one of the available property value names.
// - Aliases in PropertyAlias.txt and PropertyValueAlias.txt can be used.
// - Loose matching is not applied.
if (current() == '{') {
// Parse \p{[PropertyName=]PropertyNameValue}
for (Advance(); current() != '}' && current() != '='; Advance()) {
if (!IsUnicodePropertyValueCharacter(current())) return false;
if (!has_next()) return false;
name_1->push_back(static_cast<char>(current()));
}
if (current() == '=') {
for (Advance(); current() != '}'; Advance()) {
if (!IsUnicodePropertyValueCharacter(current())) return false;
if (!has_next()) return false;
name_2->push_back(static_cast<char>(current()));
}
name_2->push_back(0); // null-terminate string.
}
} else {
return false;
}
Advance();
name_1->push_back(0); // null-terminate string.
DCHECK(name_1->size() - 1 == std::strlen(name_1->data()));
DCHECK(name_2->empty() || name_2->size() - 1 == std::strlen(name_2->data()));
return true;
}
template <class CharT>
bool RegExpParserImpl<CharT>::AddPropertyClassRange(
ZoneList<CharacterRange>* add_to_ranges,
CharacterClassStrings* add_to_strings, bool negate,
const ZoneVector<char>& name_1, const ZoneVector<char>& name_2) {
if (name_2.empty()) {
// First attempt to interpret as general category property value name.
const char* name = name_1.data();
if (LookupPropertyValueName(UCHAR_GENERAL_CATEGORY_MASK, name, negate,
add_to_ranges, add_to_strings, flags(),
zone())) {
return true;
}
// Interpret "Any", "ASCII", and "Assigned".
if (LookupSpecialPropertyValueName(name, add_to_ranges, negate, flags(),
zone())) {
return true;
}
// Then attempt to interpret as binary property name with value name 'Y'.
UProperty property = u_getPropertyEnum(name);
if (!IsSupportedBinaryProperty(property, unicode_sets())) return false;
if (!IsExactPropertyAlias(name, property)) return false;
// Negation of properties with strings is not allowed.
// See
// https://tc39.es/ecma262/#sec-static-semantics-maycontainstrings
if (negate && IsBinaryPropertyOfStrings(property)) return false;
if (unicode_sets()) {
// In /v mode we can't simple lookup the "false" binary property values,
// as the spec requires us to perform case folding before calculating the
// complement.
// See https://tc39.es/ecma262/#sec-compiletocharset
// UnicodePropertyValueExpression :: LoneUnicodePropertyNameOrValue
return LookupPropertyValueName(property, "Y", negate, add_to_ranges,
add_to_strings, flags(), zone());
} else {
return LookupPropertyValueName(property, negate ? "N" : "Y", false,
add_to_ranges, add_to_strings, flags(),
zone());
}
} else {
// Both property name and value name are specified. Attempt to interpret
// the property name as enumerated property.
const char* property_name = name_1.data();
const char* value_name = name_2.data();
UProperty property = u_getPropertyEnum(property_name);
if (!IsExactPropertyAlias(property_name, property)) return false;
if (property == UCHAR_GENERAL_CATEGORY) {
// We want to allow aggregate value names such as "Letter".
property = UCHAR_GENERAL_CATEGORY_MASK;
} else if (property != UCHAR_SCRIPT &&
property != UCHAR_SCRIPT_EXTENSIONS) {
return false;
}
return LookupPropertyValueName(property, value_name, negate, add_to_ranges,
add_to_strings, flags(), zone());
}
}
#else // V8_INTL_SUPPORT
template <class CharT>
bool RegExpParserImpl<CharT>::ParsePropertyClassName(ZoneVector<char>* name_1,
ZoneVector<char>* name_2) {
return false;
}
template <class CharT>
bool RegExpParserImpl<CharT>::AddPropertyClassRange(
ZoneList<CharacterRange>* add_to_ranges,
CharacterClassStrings* add_to_strings, bool negate,
const ZoneVector<char>& name_1, const ZoneVector<char>& name_2) {
return false;
}
#endif // V8_INTL_SUPPORT
template <class CharT>
bool RegExpParserImpl<CharT>::ParseUnlimitedLengthHexNumber(int max_value,
base::uc32* value) {
base::uc32 x = 0;
int d = base::HexValue(current());
if (d < 0) {
return false;
}
while (d >= 0) {
x = x * 16 + d;
if (x > static_cast<base::uc32>(max_value)) {
return false;
}
Advance();
d = base::HexValue(current());
}
*value = x;
return true;
}
// https://tc39.es/ecma262/#prod-CharacterEscape
template <class CharT>
base::uc32 RegExpParserImpl<CharT>::ParseCharacterEscape(
InClassEscapeState in_class_escape_state,
bool* is_escaped_unicode_character) {
DCHECK_EQ('\\', current());
DCHECK(has_next());
Advance();
const base::uc32 c = current();
switch (c) {
// CharacterEscape ::
// 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';
// CharacterEscape ::
// c ControlLetter
case 'c': {
base::uc32 controlLetter = Next();
base::uc32 letter = controlLetter & ~('A' ^ 'a');
if (letter >= 'A' && letter <= 'Z') {
Advance(2);
// Control letters mapped to ASCII control characters in the range
// 0x00-0x1F.
return controlLetter & 0x1F;
}
if (IsUnicodeMode()) {
// With /u and /v, invalid escapes are not treated as identity escapes.
ReportError(RegExpError::kInvalidUnicodeEscape);
return 0;
}
if (in_class_escape_state == InClassEscapeState::kInClass) {
// Inside a character class, we also accept digits and underscore as
// control characters, unless with /u or /v. See Annex B:
// ES#prod-annexB-ClassControlLetter
if ((controlLetter >= '0' && controlLetter <= '9') ||
controlLetter == '_') {
Advance(2);
return controlLetter & 0x1F;
}
}
// We match JSC in reading the backslash as a literal
// character instead of as starting an escape.
return '\\';
}
// CharacterEscape ::
// 0 [lookahead ∉ DecimalDigit]
// [~UnicodeMode] LegacyOctalEscapeSequence
case '0':
// \0 is interpreted as NUL if not followed by another digit.
if (Next() < '0' || Next() > '9') {
Advance();
return 0;
}
[[fallthrough]];
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.
// ES#prod-annexB-LegacyOctalEscapeSequence
if (IsUnicodeMode()) {
// With /u or /v, decimal escape is not interpreted as octal character
// code.
ReportError(RegExpError::kInvalidDecimalEscape);
return 0;
}
return ParseOctalLiteral();
// CharacterEscape ::
// HexEscapeSequence
case 'x': {
Advance();
base::uc32 value;
if (ParseHexEscape(2, &value)) return value;
if (IsUnicodeMode()) {
// With /u or /v, invalid escapes are not treated as identity escapes.
ReportError(RegExpError::kInvalidEscape);
return 0;
}
// If \x is not followed by a two-digit hexadecimal, treat it
// as an identity escape.
return 'x';
}
// CharacterEscape ::
// RegExpUnicodeEscapeSequence [?UnicodeMode]
case 'u': {
Advance();
base::uc32 value;
if (ParseUnicodeEscape(&value)) {
*is_escaped_unicode_character = true;
return value;
}
if (IsUnicodeMode()) {
// With /u or /v, invalid escapes are not treated as identity escapes.
ReportError(RegExpError::kInvalidUnicodeEscape);
return 0;
}
// If \u is not followed by a two-digit hexadecimal, treat it
// as an identity escape.
return 'u';
}
default:
break;
}
// CharacterEscape ::
// IdentityEscape[?UnicodeMode, ?N]
//
// * With /u, no identity escapes except for syntax characters are
// allowed.
// * With /v, no identity escapes except for syntax characters and
// ClassSetReservedPunctuators (if within a class) are allowed.
// * Without /u or /v:
// * '\c' is not an IdentityEscape.
// * '\k' is not an IdentityEscape when named captures exist.
// * Otherwise, all identity escapes are allowed.
if (unicode_sets() && in_class_escape_state == InClassEscapeState::kInClass) {
if (IsClassSetReservedPunctuator(c)) {
Advance();
return c;
}
}
if (IsUnicodeMode()) {
if (!IsSyntaxCharacterOrSlash(c)) {
ReportError(RegExpError::kInvalidEscape);
return 0;
}
Advance();
return c;
}
DCHECK(!IsUnicodeMode());
if (c == 'c') {
ReportError(RegExpError::kInvalidEscape);
return 0;
}
Advance();
// Note: It's important to Advance before the HasNamedCaptures call s.t. we
// don't start scanning in the middle of an escape.
if (c == 'k' && HasNamedCaptures(in_class_escape_state)) {
ReportError(RegExpError::kInvalidEscape);
return 0;
}
return c;
}
// https://tc39.es/ecma262/#prod-ClassRanges
template <class CharT>
RegExpTree* RegExpParserImpl<CharT>::ParseClassRanges(
ZoneList<CharacterRange>* ranges, bool add_unicode_case_equivalents) {
base::uc32 char_1, char_2;
bool is_class_1, is_class_2;
while (has_more() && current() != ']') {
ParseClassEscape(ranges, zone(), add_unicode_case_equivalents, &char_1,
&is_class_1 CHECK_FAILED);
// ClassAtom
if (current() == '-') {
Advance();
if (!has_more()) {
// If we reach the end we break out of the loop and let the
// following code report an error.
break;
} else if (current() == ']') {
if (!is_class_1) ranges->Add(CharacterRange::Singleton(char_1), zone());
ranges->Add(CharacterRange::Singleton('-'), zone());
break;
}
ParseClassEscape(ranges, zone(), add_unicode_case_equivalents, &char_2,
&is_class_2 CHECK_FAILED);
if (is_class_1 || is_class_2) {
// Either end is an escaped character class. Treat the '-' verbatim.
if (IsUnicodeMode()) {
// ES2015 21.2.2.15.1 step 1.
return ReportError(RegExpError::kInvalidCharacterClass);
}
if (!is_class_1) ranges->Add(CharacterRange::Singleton(char_1), zone());
ranges->Add(CharacterRange::Singleton('-'), zone());
if (!is_class_2) ranges->Add(CharacterRange::Singleton(char_2), zone());
continue;
}
// ES2015 21.2.2.15.1 step 6.
if (char_1 > char_2) {
return ReportError(RegExpError::kOutOfOrderCharacterClass);
}
ranges->Add(CharacterRange::Range(char_1, char_2), zone());
} else {
if (!is_class_1) ranges->Add(CharacterRange::Singleton(char_1), zone());
}
}
return nullptr;
}
// https://tc39.es/ecma262/#prod-ClassEscape
template <class CharT>
void RegExpParserImpl<CharT>::ParseClassEscape(
ZoneList<CharacterRange>* ranges, Zone* zone,
bool add_unicode_case_equivalents, base::uc32* char_out,
bool* is_class_escape) {
*is_class_escape = false;
if (current() != '\\') {
// Not a ClassEscape.
*char_out = current();
Advance();
return;
}
const base::uc32 next = Next();
switch (next) {
case 'b':
*char_out = '\b';
Advance(2);
return;
case '-':
if (IsUnicodeMode()) {
*char_out = next;
Advance(2);
return;
}
break;
case kEndMarker:
ReportError(RegExpError::kEscapeAtEndOfPattern);
return;
default:
break;
}
static constexpr InClassEscapeState kInClassEscape =
InClassEscapeState::kInClass;
*is_class_escape =
TryParseCharacterClassEscape(next, kInClassEscape, ranges, nullptr, zone,
add_unicode_case_equivalents);
if (*is_class_escape) return;
bool dummy = false; // Unused.
*char_out = ParseCharacterEscape(kInClassEscape, &dummy);
}
// https://tc39.es/ecma262/#prod-CharacterClassEscape
template <class CharT>
bool RegExpParserImpl<CharT>::TryParseCharacterClassEscape(
base::uc32 next, InClassEscapeState in_class_escape_state,
ZoneList<CharacterRange>* ranges, CharacterClassStrings* strings,
Zone* zone, bool add_unicode_case_equivalents) {
DCHECK_EQ(current(), '\\');
DCHECK_EQ(Next(), next);
switch (next) {
case 'd':
case 'D':
case 's':
case 'S':
case 'w':
case 'W':
CharacterRange::AddClassEscape(static_cast<StandardCharacterSet>(next),
ranges, add_unicode_case_equivalents,
zone);
Advance(2);
return true;
case 'p':
case 'P': {
if (!IsUnicodeMode()) return false;
bool negate = next == 'P';
Advance(2);
ZoneVector<char> name_1(zone);
ZoneVector<char> name_2(zone);
if (!ParsePropertyClassName(&name_1, &name_2) ||
!AddPropertyClassRange(ranges, strings, negate, name_1, name_2)) {
ReportError(in_class_escape_state == InClassEscapeState::kInClass
? RegExpError::kInvalidClassPropertyName
: RegExpError::kInvalidPropertyName);
}
return true;
}
default:
return false;
}
}
namespace {
// Add |string| to |ranges| if length of |string| == 1, otherwise add |string|
// to |strings|.
void AddClassString(ZoneList<base::uc32>* normalized_string,
RegExpTree* regexp_string, ZoneList<CharacterRange>* ranges,
CharacterClassStrings* strings, Zone* zone) {
if (normalized_string->length() == 1) {
ranges->Add(CharacterRange::Singleton(normalized_string->at(0)), zone);
} else {
strings->emplace(normalized_string->ToVector(), regexp_string);
}
}
} // namespace
// https://tc39.es/ecma262/#prod-ClassStringDisjunction
template <class CharT>
RegExpTree* RegExpParserImpl<CharT>::ParseClassStringDisjunction(
ZoneList<CharacterRange>* ranges, CharacterClassStrings* strings) {
DCHECK(unicode_sets());
DCHECK_EQ(current(), '\\');
DCHECK_EQ(Next(), 'q');
Advance(2);
if (current() != '{') {
// Identity escape of 'q' is not allowed in unicode mode.
return ReportError(RegExpError::kInvalidEscape);
}
Advance();
ZoneList<base::uc32>* string =
zone()->template New<ZoneList<base::uc32>>(4, zone());
RegExpTextBuilder::SmallRegExpTreeVector string_storage(zone());
RegExpTextBuilder string_builder(zone(), &string_storage, flags());
while (has_more() && current() != '}') {
if (current() == '|') {
AddClassString(string, string_builder.ToRegExp(), ranges, strings,
zone());
string = zone()->template New<ZoneList<base::uc32>>(4, zone());
string_storage.clear();
Advance();
} else {
base::uc32 c = ParseClassSetCharacter(CHECK_FAILED);
if (ignore_case()) {
#ifdef V8_INTL_SUPPORT
c = u_foldCase(c, U_FOLD_CASE_DEFAULT);
#else
c = AsciiAlphaToLower(c);
#endif
}
string->Add(c, zone());
string_builder.AddUnicodeCharacter(c);
}
}
AddClassString(string, string_builder.ToRegExp(), ranges, strings, zone());
CharacterRange::Canonicalize(ranges);
// We don't need to handle missing closing '}' here.
// If the character class is correctly closed, ParseClassSetCharacter will
// report an error.
Advance();
return nullptr;
}
// https://tc39.es/ecma262/#prod-ClassSetOperand
// Tree returned based on type_out:
// * kNestedClass: RegExpClassSetExpression
// * For all other types: RegExpClassSetOperand
template <class CharT>
RegExpTree* RegExpParserImpl<CharT>::ParseClassSetOperand(
const RegExpBuilder* builder, ClassSetOperandType* type_out) {
ZoneList<CharacterRange>* ranges =
zone()->template New<ZoneList<CharacterRange>>(1, zone());
CharacterClassStrings* strings =
zone()->template New<CharacterClassStrings>(zone());
base::uc32 character;
RegExpTree* tree = ParseClassSetOperand(builder, type_out, ranges, strings,
&character CHECK_FAILED);
DCHECK_IMPLIES(*type_out != ClassSetOperandType::kNestedClass,
tree == nullptr);
DCHECK_IMPLIES(*type_out == ClassSetOperandType::kClassSetCharacter,
ranges->is_empty());
DCHECK_IMPLIES(*type_out == ClassSetOperandType::kClassSetCharacter,
strings->empty());
DCHECK_IMPLIES(*type_out == ClassSetOperandType::kNestedClass,
ranges->is_empty());
DCHECK_IMPLIES(*type_out == ClassSetOperandType::kNestedClass,
strings->empty());
DCHECK_IMPLIES(*type_out == ClassSetOperandType::kNestedClass,
tree->IsClassSetExpression());
// ClassSetRange is only used within ClassSetUnion().
DCHECK_NE(*type_out, ClassSetOperandType::kClassSetRange);
// There are no restrictions for kCharacterClassEscape.
// CharacterClassEscape includes \p{}, which can contain ranges, strings or
// both and \P{}, which could contain nothing (i.e. \P{Any}).
if (tree == nullptr) {
if (*type_out == ClassSetOperandType::kClassSetCharacter) {
AddMaybeSimpleCaseFoldedRange(ranges,
CharacterRange::Singleton(character));
}
tree = zone()->template New<RegExpClassSetOperand>(ranges, strings);
}
return tree;
}
// https://tc39.es/ecma262/#prod-ClassSetOperand
// Based on |type_out| either a tree is returned or
// |ranges|/|strings|/|character| modified. If a tree is returned,
// ranges/strings are not modified. If |type_out| is kNestedClass, a tree of
// type RegExpClassSetExpression is returned. If | type_out| is
// kClassSetCharacter, |character| is set and nullptr returned. For all other
// types, |ranges|/|strings|/|character| is modified and nullptr is returned.
template <class CharT>
RegExpTree* RegExpParserImpl<CharT>::ParseClassSetOperand(
const RegExpBuilder* builder, ClassSetOperandType* type_out,
ZoneList<CharacterRange>* ranges, CharacterClassStrings* strings,
base::uc32* character) {
DCHECK(unicode_sets());
base::uc32 c = current();
if (c == '\\') {
const base::uc32 next = Next();
if (next == 'q') {
*type_out = ClassSetOperandType::kClassStringDisjunction;
ParseClassStringDisjunction(ranges, strings CHECK_FAILED);
return nullptr;
}
static constexpr InClassEscapeState kInClassEscape =
InClassEscapeState::kInClass;
const bool add_unicode_case_equivalents = ignore_case();
if (TryParseCharacterClassEscape(next, kInClassEscape, ranges, strings,
zone(), add_unicode_case_equivalents)) {
*type_out = ClassSetOperandType::kCharacterClassEscape;
return nullptr;
}
}
if (c == '[') {
*type_out = ClassSetOperandType::kNestedClass;
return ParseCharacterClass(builder);
}
*type_out = ClassSetOperandType::kClassSetCharacter;
c = ParseClassSetCharacter(CHECK_FAILED);
*character = c;
return nullptr;
}
template <class CharT>
base::uc32 RegExpParserImpl<CharT>::ParseClassSetCharacter() {
DCHECK(unicode_sets());
const base::uc32 c = current();
if (c == '\\') {
const base::uc32 next = Next();
switch (next) {
case 'b':
Advance(2);
return '\b';
case kEndMarker:
ReportError(RegExpError::kEscapeAtEndOfPattern);
return 0;
}
static constexpr InClassEscapeState kInClassEscape =
InClassEscapeState::kInClass;
bool dummy = false; // Unused.
return ParseCharacterEscape(kInClassEscape, &dummy);
}
if (IsClassSetSyntaxCharacter(c)) {
ReportError(RegExpError::kInvalidCharacterInClass);
return 0;
}
if (IsClassSetReservedDoublePunctuator(c)) {
ReportError(RegExpError::kInvalidClassSetOperation);
return 0;
}
Advance();
return c;
}
namespace {
bool MayContainStrings(ClassSetOperandType type, RegExpTree* operand) {
switch (type) {
case ClassSetOperandType::kClassSetCharacter:
case ClassSetOperandType::kClassSetRange:
return false;
case ClassSetOperandType::kCharacterClassEscape:
case ClassSetOperandType::kClassStringDisjunction:
return operand->AsClassSetOperand()->has_strings();
case ClassSetOperandType::kNestedClass:
if (operand->IsClassRanges()) return false;
return operand->AsClassSetExpression()->may_contain_strings();
}
}
} // namespace
template <class CharT>
void RegExpParserImpl<CharT>::AddMaybeSimpleCaseFoldedRange(
ZoneList<CharacterRange>* ranges, CharacterRange new_range) {
DCHECK(unicode_sets());
if (ignore_case()) {
ZoneList<CharacterRange>* new_ranges =
zone()->template New<ZoneList<CharacterRange>>(2, zone());
new_ranges->Add(new_range, zone());
CharacterRange::AddUnicodeCaseEquivalents(new_ranges, zone());
ranges->AddAll(*new_ranges, zone());
} else {
ranges->Add(new_range, zone());
}
CharacterRange::Canonicalize(ranges);
}
// https://tc39.es/ecma262/#prod-ClassUnion
template <class CharT>
RegExpTree* RegExpParserImpl<CharT>::ParseClassUnion(
const RegExpBuilder* builder, bool is_negated, RegExpTree* first_operand,
ClassSetOperandType first_operand_type, ZoneList<CharacterRange>* ranges,
CharacterClassStrings* strings, base::uc32 character) {
DCHECK(unicode_sets());
ZoneList<RegExpTree*>* operands =
zone()->template New<ZoneList<RegExpTree*>>(2, zone());
bool may_contain_strings = false;
// Add the lhs to operands if necessary.
// Either the lhs values were added to |ranges|/|strings| (in which case
// |first_operand| is nullptr), or the lhs was evaluated to a tree and passed
// as |first_operand| (in which case |ranges| and |strings| are empty).
if (first_operand != nullptr) {
may_contain_strings = MayContainStrings(first_operand_type, first_operand);
operands->Add(first_operand, zone());
}
ClassSetOperandType last_type = first_operand_type;
while (has_more() && current() != ']') {
if (current() == '-') {
// Mix of ClassSetRange and ClassSubtraction is not allowed.
if (Next() == '-') {
return ReportError(RegExpError::kInvalidClassSetOperation);
}
Advance();
if (!has_more()) {
// If we reach the end we break out of the loop and let the
// following code report an error.
break;
}
// If the lhs and rhs around '-' are both ClassSetCharacters, they
// represent a character range.
// In case one of them is not a ClassSetCharacter, it is a syntax error,
// as '-' can not be used unescaped within a class with /v.
// See
// https://tc39.es/ecma262/#prod-ClassSetRange
if (last_type != ClassSetOperandType::kClassSetCharacter) {
return ReportError(RegExpError::kInvalidCharacterClass);
}
base::uc32 from = character;
ParseClassSetOperand(builder, &last_type, ranges, strings,
&character CHECK_FAILED);
if (last_type != ClassSetOperandType::kClassSetCharacter) {
return ReportError(RegExpError::kInvalidCharacterClass);
}
if (from > character) {
return ReportError(RegExpError::kOutOfOrderCharacterClass);
}
AddMaybeSimpleCaseFoldedRange(ranges,
CharacterRange::Range(from, character));
last_type = ClassSetOperandType::kClassSetRange;
} else {
DCHECK_NE(current(), '-');
if (last_type == ClassSetOperandType::kClassSetCharacter) {
AddMaybeSimpleCaseFoldedRange(ranges,
CharacterRange::Singleton(character));
}
RegExpTree* operand = ParseClassSetOperand(
builder, &last_type, ranges, strings, &character CHECK_FAILED);
if (operand != nullptr) {
may_contain_strings |= MayContainStrings(last_type, operand);
// Add the range we started building as operand and reset the current
// range.
if (!ranges->is_empty() || !strings->empty()) {
may_contain_strings |= !strings->empty();
operands->Add(
zone()->template New<RegExpClassSetOperand>(ranges, strings),
zone());
ranges = zone()->template New<ZoneList<CharacterRange>>(2, zone());
strings = zone()->template New<CharacterClassStrings>(zone());
}
operands->Add(operand, zone());
}
}
}
if (!has_more()) {
return ReportError(RegExpError::kUnterminatedCharacterClass);
}
if (last_type == ClassSetOperandType::kClassSetCharacter) {
AddMaybeSimpleCaseFoldedRange(ranges, CharacterRange::Singleton(character));
}
// Add the range we started building as operand.
if (!ranges->is_empty() || !strings->empty()) {
may_contain_strings |= !strings->empty();
operands->Add(zone()->template New<RegExpClassSetOperand>(ranges, strings),
zone());
}
DCHECK_EQ(current(), ']');
Advance();
if (is_negated && may_contain_strings) {
return ReportError(RegExpError::kNegatedCharacterClassWithStrings);
}
if (operands->is_empty()) {
// Return empty expression if no operands were added (e.g. [\P{Any}]
// produces an empty range).
DCHECK(ranges->is_empty());
DCHECK(strings->empty());
return RegExpClassSetExpression::Empty(zone(), is_negated);
}
return zone()->template New<RegExpClassSetExpression>(
RegExpClassSetExpression::OperationType::kUnion, is_negated,
may_contain_strings, operands);
}
// https://tc39.es/ecma262/#prod-ClassIntersection
template <class CharT>
RegExpTree* RegExpParserImpl<CharT>::ParseClassIntersection(
const RegExpBuilder* builder, bool is_negated, RegExpTree* first_operand,
ClassSetOperandType first_operand_type) {
DCHECK(unicode_sets());
DCHECK(current() == '&' && Next() == '&');
bool may_contain_strings =
MayContainStrings(first_operand_type, first_operand);
ZoneList<RegExpTree*>* operands =
zone()->template New<ZoneList<RegExpTree*>>(2, zone());
operands->Add(first_operand, zone());
while (has_more() && current() != ']') {
if (current() != '&' || Next() != '&') {
return ReportError(RegExpError::kInvalidClassSetOperation);
}
Advance(2);
// [lookahead ≠ &]
if (current() == '&') {
return ReportError(RegExpError::kInvalidCharacterInClass);
}
ClassSetOperandType operand_type;
RegExpTree* operand =
ParseClassSetOperand(builder, &operand_type CHECK_FAILED);
may_contain_strings &= MayContainStrings(operand_type, operand);
operands->Add(operand, zone());
}
if (!has_more()) {
return ReportError(RegExpError::kUnterminatedCharacterClass);
}
if (is_negated && may_contain_strings) {
return ReportError(RegExpError::kNegatedCharacterClassWithStrings);
}
DCHECK_EQ(current(), ']');
Advance();
return zone()->template New<RegExpClassSetExpression>(
RegExpClassSetExpression::OperationType::kIntersection, is_negated,
may_contain_strings, operands);
}
// https://tc39.es/ecma262/#prod-ClassSubtraction
template <class CharT>
RegExpTree* RegExpParserImpl<CharT>::ParseClassSubtraction(
const RegExpBuilder* builder, bool is_negated, RegExpTree* first_operand,
ClassSetOperandType first_operand_type) {
DCHECK(unicode_sets());
DCHECK(current() == '-' && Next() == '-');
const bool may_contain_strings =
MayContainStrings(first_operand_type, first_operand);
if (is_negated && may_contain_strings) {
return ReportError(RegExpError::kNegatedCharacterClassWithStrings);
}
ZoneList<RegExpTree*>* operands =
zone()->template New<ZoneList<RegExpTree*>>(2, zone());
operands->Add(first_operand, zone());
while (has_more() && current() != ']') {
if (current() != '-' || Next() != '-') {
return ReportError(RegExpError::kInvalidClassSetOperation);
}
Advance(2);
ClassSetOperandType dummy; // unused
RegExpTree* operand = ParseClassSetOperand(builder, &dummy CHECK_FAILED);
operands->Add(operand, zone());
}
if (!has_more()) {
return ReportError(RegExpError::kUnterminatedCharacterClass);
}
DCHECK_EQ(current(), ']');
Advance();
return zone()->template New<RegExpClassSetExpression>(
RegExpClassSetExpression::OperationType::kSubtraction, is_negated,
may_contain_strings, operands);
}
// https://tc39.es/ecma262/#prod-CharacterClass
template <class CharT>
RegExpTree* RegExpParserImpl<CharT>::ParseCharacterClass(
const RegExpBuilder* builder) {
DCHECK_EQ(current(), '[');
Advance();
bool is_negated = false;
if (current() == '^') {
is_negated = true;
Advance();
}
ZoneList<CharacterRange>* ranges =
zone()->template New<ZoneList<CharacterRange>>(2, zone());
if (current() == ']') {
Advance();
if (unicode_sets()) {
return RegExpClassSetExpression::Empty(zone(), is_negated);
} else {
RegExpClassRanges::ClassRangesFlags class_ranges_flags;
if (is_negated) class_ranges_flags = RegExpClassRanges::NEGATED;
return zone()->template New<RegExpClassRanges>(zone(), ranges,
class_ranges_flags);
}
}
if (!unicode_sets()) {
bool add_unicode_case_equivalents = IsUnicodeMode() && ignore_case();
ParseClassRanges(ranges, add_unicode_case_equivalents CHECK_FAILED);
if (!has_more()) {
return ReportError(RegExpError::kUnterminatedCharacterClass);
}
DCHECK_EQ(current(), ']');
Advance();
RegExpClassRanges::ClassRangesFlags character_class_flags;
if (is_negated) character_class_flags = RegExpClassRanges::NEGATED;
return zone()->template New<RegExpClassRanges>(zone(), ranges,
character_class_flags);
} else {
ClassSetOperandType operand_type;
CharacterClassStrings* strings =
zone()->template New<CharacterClassStrings>(zone());
base::uc32 character;
RegExpTree* operand = ParseClassSetOperand(
builder, &operand_type, ranges, strings, &character CHECK_FAILED);
switch (current()) {
case '-':
if (Next() == '-') {
if (operand == nullptr) {
if (operand_type == ClassSetOperandType::kClassSetCharacter) {
AddMaybeSimpleCaseFoldedRange(
ranges, CharacterRange::Singleton(character));
}
operand =
zone()->template New<RegExpClassSetOperand>(ranges, strings);
}
return ParseClassSubtraction(builder, is_negated, operand,
operand_type);
}
// ClassSetRange is handled in ParseClassUnion().
break;
case '&':
if (Next() == '&') {
if (operand == nullptr) {
if (operand_type == ClassSetOperandType::kClassSetCharacter) {
AddMaybeSimpleCaseFoldedRange(
ranges, CharacterRange::Singleton(character));
}
operand =
zone()->template New<RegExpClassSetOperand>(ranges, strings);
}
return ParseClassIntersection(builder, is_negated, operand,
operand_type);
}
}
return ParseClassUnion(builder, is_negated, operand, operand_type, ranges,
strings, character);
}
}
#undef CHECK_FAILED
template <class CharT>
bool RegExpParserImpl<CharT>::Parse(RegExpCompileData* result) {
DCHECK_NOT_NULL(result);
RegExpTree* tree = ParsePattern();
if (failed()) {
DCHECK_NULL(tree);
DCHECK_NE(error_, RegExpError::kNone);
result->error = error_;
result->error_pos = error_pos_;
return false;
}
DCHECK_NOT_NULL(tree);
DCHECK_EQ(error_, RegExpError::kNone);
if (v8_flags.trace_regexp_parser) {
StdoutStream os;
tree->Print(os, zone());
os << "\n";
}
result->tree = tree;
const int capture_count = captures_started();
result->simple = tree->IsAtom() && simple() && capture_count == 0;
result->contains_anchor = contains_anchor();
result->capture_count = capture_count;
result->named_captures = GetNamedCaptures();
return true;
}
void RegExpBuilder::FlushText() { text_builder().FlushText(); }
void RegExpBuilder::AddCharacter(base::uc16 c) {
pending_empty_ = false;
text_builder().AddCharacter(c);
}
void RegExpBuilder::AddUnicodeCharacter(base::uc32 c) {
pending_empty_ = false;
text_builder().AddUnicodeCharacter(c);
}
void RegExpBuilder::AddEscapedUnicodeCharacter(base::uc32 character) {
pending_empty_ = false;
text_builder().AddEscapedUnicodeCharacter(character);
}
void RegExpBuilder::AddEmpty() {
text_builder().FlushPendingSurrogate();
pending_empty_ = true;
}
void RegExpBuilder::AddClassRanges(RegExpClassRanges* cc) {
pending_empty_ = false;
text_builder().AddClassRanges(cc);
}
void RegExpBuilder::AddAtom(RegExpTree* term) {
if (term->IsEmpty()) {
AddEmpty();
return;
}
pending_empty_ = false;
if (term->IsTextElement()) {
text_builder().AddAtom(term);
} else {
FlushText();
terms_.emplace_back(term);
}
}
void RegExpBuilder::AddTerm(RegExpTree* term) {
DCHECK(!term->IsEmpty());
pending_empty_ = false;
if (term->IsTextElement()) {
text_builder().AddTerm(term);
} else {
FlushText();
terms_.emplace_back(term);
}
}
void RegExpBuilder::AddAssertion(RegExpTree* assert) {
FlushText();
pending_empty_ = false;
terms_.emplace_back(assert);
}
void RegExpBuilder::NewAlternative() { FlushTerms(); }
void RegExpBuilder::FlushTerms() {
FlushText();
size_t num_terms = terms_.size();
RegExpTree* alternative;
if (num_terms == 0) {
alternative = zone()->New<RegExpEmpty>();
} else if (num_terms == 1) {
alternative = terms_.back();
} else {
alternative =
zone()->New<RegExpAlternative>(zone()->New<ZoneList<RegExpTree*>>(
base::VectorOf(terms_.begin(), terms_.size()), zone()));
}
alternatives_.emplace_back(alternative);
terms_.clear();
}
RegExpTree* RegExpBuilder::ToRegExp() {
FlushTerms();
size_t num_alternatives = alternatives_.size();
if (num_alternatives == 0) return zone()->New<RegExpEmpty>();
if (num_alternatives == 1) return alternatives_.back();
return zone()->New<RegExpDisjunction>(zone()->New<ZoneList<RegExpTree*>>(
base::VectorOf(alternatives_.begin(), alternatives_.size()), zone()));
}
bool RegExpBuilder::AddQuantifierToAtom(
int min, int max, int index,
RegExpQuantifier::QuantifierType quantifier_type) {
if (pending_empty_) {
pending_empty_ = false;
return true;
}
RegExpTree* atom = text_builder().PopLastAtom();
if (atom != nullptr) {
FlushText();
} else if (!terms_.empty()) {
atom = terms_.back();
terms_.pop_back();
if (atom->IsLookaround()) {
// With /u or /v, lookarounds are not quantifiable.
if (IsUnicodeMode()) return false;
// Lookbehinds are not quantifiable.
if (atom->AsLookaround()->type() == RegExpLookaround::LOOKBEHIND) {
return false;
}
}
if (atom->max_match() == 0) {
// Guaranteed to only match an empty string.
if (min == 0) {
return true;
}
terms_.emplace_back(atom);
return true;
}
} else {
// Only call immediately after adding an atom or character!
UNREACHABLE();
}
terms_.emplace_back(
zone()->New<RegExpQuantifier>(min, max, quantifier_type, index, atom));
return true;
}
template class RegExpParserImpl<uint8_t>;
template class RegExpParserImpl<base::uc16>;
} // namespace
// static
bool RegExpParser::ParseRegExpFromHeapString(Isolate* isolate, Zone* zone,
DirectHandle<String> input,
RegExpFlags flags,
RegExpCompileData* result) {
DisallowGarbageCollection no_gc;
uintptr_t stack_limit = isolate->stack_guard()->real_climit();
String::FlatContent content = input->GetFlatContent(no_gc);
if (content.IsOneByte()) {
base::Vector<const uint8_t> v = content.ToOneByteVector();
return RegExpParserImpl<uint8_t>{v.begin(), v.length(), flags,
stack_limit, zone, no_gc}
.Parse(result);
} else {
base::Vector<const base::uc16> v = content.ToUC16Vector();
return RegExpParserImpl<base::uc16>{v.begin(), v.length(), flags,
stack_limit, zone, no_gc}
.Parse(result);
}
}
// static
template <class CharT>
bool RegExpParser::VerifyRegExpSyntax(Zone* zone, uintptr_t stack_limit,
const CharT* input, int input_length,
RegExpFlags flags,
RegExpCompileData* result,
const DisallowGarbageCollection& no_gc) {
return RegExpParserImpl<CharT>{input, input_length, flags,
stack_limit, zone, no_gc}
.Parse(result);
}
template bool RegExpParser::VerifyRegExpSyntax<uint8_t>(
Zone*, uintptr_t, const uint8_t*, int, RegExpFlags, RegExpCompileData*,
const DisallowGarbageCollection&);
template bool RegExpParser::VerifyRegExpSyntax<base::uc16>(
Zone*, uintptr_t, const base::uc16*, int, RegExpFlags, RegExpCompileData*,
const DisallowGarbageCollection&);
} // namespace internal
} // namespace v8