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Implement regex lookaround.

This commit is contained in:
Fedor 2019-12-25 15:45:50 +03:00
parent 45cfa8084f
commit b8c8d932f2
13 changed files with 361 additions and 159 deletions
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6
js/src/builtin/TestingFunctions.cpp
View File

@ -3900,10 +3900,10 @@ ConvertRegExpTreeToObject(JSContext* cx, irregexp::RegExpTree* tree)
return nullptr;
return obj;
}
if (tree->IsLookahead()) {
if (!StringProp(cx, obj, "type", "Lookahead"))
if (tree->IsLookaround()) {
if (!StringProp(cx, obj, "type", "Lookaround"))
return nullptr;
irregexp::RegExpLookahead* t = tree->AsLookahead();
irregexp::RegExpLookaround* t = tree->AsLookaround();
if (!BooleanProp(cx, obj, "is_positive", t->is_positive()))
return nullptr;
if (!TreeProp(cx, obj, "body", t->body()))

8
js/src/irregexp/NativeRegExpMacroAssembler.cpp
View File

@ -582,7 +582,7 @@ NativeRegExpMacroAssembler::CheckAtStart(Label* on_at_start)
}
void
NativeRegExpMacroAssembler::CheckNotAtStart(Label* on_not_at_start)
NativeRegExpMacroAssembler::CheckNotAtStart(int cp_offset, Label* on_not_at_start)
{
JitSpew(SPEW_PREFIX "CheckNotAtStart");
@ -673,7 +673,7 @@ NativeRegExpMacroAssembler::CheckGreedyLoop(Label* on_tos_equals_current_positio
}
void
NativeRegExpMacroAssembler::CheckNotBackReference(int start_reg, Label* on_no_match)
NativeRegExpMacroAssembler::CheckNotBackReference(int start_reg, bool read_backward, Label* on_no_match)
{
JitSpew(SPEW_PREFIX "CheckNotBackReference(%d)", start_reg);
@ -744,8 +744,8 @@ NativeRegExpMacroAssembler::CheckNotBackReference(int start_reg, Label* on_no_ma
}
void
NativeRegExpMacroAssembler::CheckNotBackReferenceIgnoreCase(int start_reg, Label* on_no_match,
bool unicode)
NativeRegExpMacroAssembler::CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
Label* on_no_match, bool unicode)
{
JitSpew(SPEW_PREFIX "CheckNotBackReferenceIgnoreCase(%d, %d)", start_reg, unicode);

7
js/src/irregexp/NativeRegExpMacroAssembler.h
View File

@ -105,9 +105,10 @@ class MOZ_STACK_CLASS NativeRegExpMacroAssembler final : public RegExpMacroAssem
void CheckCharacterGT(char16_t limit, jit::Label* on_greater);
void CheckCharacterLT(char16_t limit, jit::Label* on_less);
void CheckGreedyLoop(jit::Label* on_tos_equals_current_position);
void CheckNotAtStart(jit::Label* on_not_at_start);
void CheckNotBackReference(int start_reg, jit::Label* on_no_match);
void CheckNotBackReferenceIgnoreCase(int start_reg, jit::Label* on_no_match, bool unicode);
void CheckNotAtStart(int cp_offset, jit::Label* on_not_at_start);
void CheckNotBackReference(int start_reg, bool read_backward, jit::Label* on_no_match);
void CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
jit::Label* on_no_match, bool unicode);
void CheckNotCharacter(unsigned c, jit::Label* on_not_equal);
void CheckNotCharacterAfterAnd(unsigned c, unsigned and_with, jit::Label* on_not_equal);
void CheckNotCharacterAfterMinusAnd(char16_t c, char16_t minus, char16_t and_with,

8
js/src/irregexp/RegExpAST.cpp
View File

@ -250,16 +250,16 @@ RegExpCapture::CaptureRegisters()
}
// ----------------------------------------------------------------------------
// RegExpLookahead
// RegExpLookaround
Interval
RegExpLookahead::CaptureRegisters()
RegExpLookaround::CaptureRegisters()
{
return body()->CaptureRegisters();
}
bool
RegExpLookahead::IsAnchoredAtStart()
RegExpLookaround::IsAnchoredAtStart()
{
return is_positive() && body()->IsAnchoredAtStart();
return is_positive() && type() == LOOKAHEAD && body()->IsAnchoredAtStart();
}

33
js/src/irregexp/RegExpAST.h
View File

@ -360,6 +360,7 @@ class RegExpCapture : public RegExpTree
virtual int min_match() { return body_->min_match(); }
virtual int max_match() { return body_->max_match(); }
RegExpTree* body() { return body_; }
void set_body(RegExpTree* body) { body_ = body; }
int index() { return index_; }
static int StartRegister(int index) { return index * 2; }
static int EndRegister(int index) { return index * 2 + 1; }
@ -369,25 +370,29 @@ class RegExpCapture : public RegExpTree
int index_;
};
class RegExpLookahead : public RegExpTree
class RegExpLookaround : public RegExpTree
{
public:
RegExpLookahead(RegExpTree* body,
bool is_positive,
int capture_count,
int capture_from)
enum Type { LOOKAHEAD, LOOKBEHIND };
RegExpLookaround(RegExpTree* body,
bool is_positive,
int capture_count,
int capture_from,
Type type)
: body_(body),
is_positive_(is_positive),
capture_count_(capture_count),
capture_from_(capture_from)
capture_from_(capture_from),
type_(type)
{}
virtual void* Accept(RegExpVisitor* visitor, void* data);
virtual RegExpNode* ToNode(RegExpCompiler* compiler,
RegExpNode* on_success);
virtual RegExpLookahead* AsLookahead();
virtual RegExpLookaround* AsLookaround();
virtual Interval CaptureRegisters();
virtual bool IsLookahead();
virtual bool IsLookaround();
virtual bool IsAnchoredAtStart();
virtual int min_match() { return 0; }
virtual int max_match() { return 0; }
@ -395,12 +400,14 @@ class RegExpLookahead : public RegExpTree
bool is_positive() { return is_positive_; }
int capture_count() { return capture_count_; }
int capture_from() { return capture_from_; }
Type type() { return type_; }
private:
RegExpTree* body_;
bool is_positive_;
int capture_count_;
int capture_from_;
Type type_;
};
typedef InfallibleVector<RegExpCapture*, 1> RegExpCaptureVector;
@ -417,8 +424,14 @@ class RegExpBackReference : public RegExpTree
RegExpNode* on_success);
virtual RegExpBackReference* AsBackReference();
virtual bool IsBackReference();
virtual int min_match() { return 0; }
virtual int max_match() { return capture_->max_match(); }
virtual int min_match() override { return 0; }
// The capture may not be completely parsed yet, if the reference occurs
// before the capture. In the ordinary case, nothing has been captured yet,
// so the back reference must have the length 0. If the back reference is
// inside a lookbehind, effectively making it a forward reference, we return
virtual int max_match() override {
return capture_->body() ? capture_->max_match() : 0;
}
int index() { return capture_->index(); }
RegExpCapture* capture() { return capture_; }
private:

23
js/src/irregexp/RegExpBytecode.h
View File

@ -82,16 +82,19 @@ V(CHECK_LT, 35, 8) /* bc8 pad8 uc16 addr32 */ \
V(CHECK_GT, 36, 8) /* bc8 pad8 uc16 addr32 */ \
V(CHECK_NOT_BACK_REF, 37, 8) /* bc8 reg_idx24 addr32 */ \
V(CHECK_NOT_BACK_REF_NO_CASE, 38, 8) /* bc8 reg_idx24 addr32 */ \
V(CHECK_NOT_REGS_EQUAL, 39, 12) /* bc8 regidx24 reg_idx32 addr32 */ \
V(CHECK_REGISTER_LT, 40, 12) /* bc8 reg_idx24 value32 addr32 */ \
V(CHECK_REGISTER_GE, 41, 12) /* bc8 reg_idx24 value32 addr32 */ \
V(CHECK_REGISTER_EQ_POS, 42, 8) /* bc8 reg_idx24 addr32 */ \
V(CHECK_AT_START, 43, 8) /* bc8 pad24 addr32 */ \
V(CHECK_NOT_AT_START, 44, 8) /* bc8 pad24 addr32 */ \
V(CHECK_GREEDY, 45, 8) /* bc8 pad24 addr32 */ \
V(ADVANCE_CP_AND_GOTO, 46, 8) /* bc8 offset24 addr32 */ \
V(SET_CURRENT_POSITION_FROM_END, 47, 4) /* bc8 idx24 */ \
V(CHECK_NOT_BACK_REF_NO_CASE_UNICODE, 48, 8) /* bc8 reg_idx24 addr32 */
V(CHECK_NOT_BACK_REF_BACKWARD, 39, 8) /* bc8 reg_idx24 addr32 */ \
V(CHECK_NOT_BACK_REF_NO_CASE_BACKWARD, 40, 8) /* bc8 reg_idx24 addr32 */ \
V(CHECK_NOT_REGS_EQUAL, 41, 12) /* bc8 regidx24 reg_idx32 addr32 */ \
V(CHECK_REGISTER_LT, 42, 12) /* bc8 reg_idx24 value32 addr32 */ \
V(CHECK_REGISTER_GE, 43, 12) /* bc8 reg_idx24 value32 addr32 */ \
V(CHECK_REGISTER_EQ_POS, 44, 8) /* bc8 reg_idx24 addr32 */ \
V(CHECK_AT_START, 45, 8) /* bc8 pad24 addr32 */ \
V(CHECK_NOT_AT_START, 46, 8) /* bc8 pad24 addr32 */ \
V(CHECK_GREEDY, 47, 8) /* bc8 pad24 addr32 */ \
V(ADVANCE_CP_AND_GOTO, 48, 8) /* bc8 offset24 addr32 */ \
V(SET_CURRENT_POSITION_FROM_END, 49, 4) /* bc8 idx24 */ \
V(CHECK_NOT_BACK_REF_NO_CASE_UNICODE, 50, 8) /* bc8 reg_idx24 addr32 */ \
V(CHECK_NOT_BACK_REF_NO_CASE_BACKWARD_UNICODE, 51, 8) /* bc8 reg_idx24 addr32 */
#define DECLARE_BYTECODES(name, code, length) \
static const int BC_##name = code;

149
js/src/irregexp/RegExpEngine.cpp
View File

@ -721,6 +721,8 @@ ActionNode::EmptyMatchCheck(int start_register,
int
TextNode::EatsAtLeast(int still_to_find, int budget, bool not_at_start)
{
if (read_backward())
return 0;
int answer = Length();
if (answer >= still_to_find)
return answer;
@ -736,8 +738,7 @@ TextNode::EatsAtLeast(int still_to_find, int budget, bool not_at_start)
int
TextNode::GreedyLoopTextLength()
{
TextElement elm = elements()[elements().length() - 1];
return elm.cp_offset() + elm.length();
return Length();
}
RegExpNode*
@ -887,6 +888,8 @@ AssertionNode::FillInBMInfo(int offset, int budget, BoyerMooreLookahead* bm, boo
int
BackReferenceNode::EatsAtLeast(int still_to_find, int budget, bool not_at_start)
{
if (read_backward())
return 0;
if (budget <= 0)
return 0;
return on_success()->EatsAtLeast(still_to_find, budget - 1, not_at_start);
@ -1578,6 +1581,9 @@ class irregexp::RegExpCompiler
current_expansion_factor_ = value;
}
bool read_backward() { return read_backward_; }
void set_read_backward(bool value) { read_backward_ = value; }
JSContext* cx() const { return cx_; }
LifoAlloc* alloc() const { return alloc_; }
@ -1595,6 +1601,7 @@ class irregexp::RegExpCompiler
bool unicode_;
bool reg_exp_too_big_;
int current_expansion_factor_;
bool read_backward_;
FrequencyCollator frequency_collator_;
JSContext* cx_;
LifoAlloc* alloc_;
@ -1624,6 +1631,7 @@ RegExpCompiler::RegExpCompiler(JSContext* cx, LifoAlloc* alloc, int capture_coun
unicode_(unicode),
reg_exp_too_big_(false),
current_expansion_factor_(1),
read_backward_(false),
frequency_collator_(),
cx_(cx),
alloc_(alloc)
@ -1747,7 +1755,7 @@ irregexp::CompilePattern(JSContext* cx, RegExpShared* shared, RegExpCompileData*
// at the start of input.
ChoiceNode* first_step_node = alloc.newInfallible<ChoiceNode>(&alloc, 2);
RegExpNode* char_class =
alloc.newInfallible<TextNode>(alloc.newInfallible<RegExpCharacterClass>('*'), loop_node);
alloc.newInfallible<TextNode>(alloc.newInfallible<RegExpCharacterClass>('*'), false, loop_node);
first_step_node->AddAlternative(GuardedAlternative(captured_body));
first_step_node->AddAlternative(GuardedAlternative(char_class));
node = first_step_node;
@ -1850,19 +1858,19 @@ RegExpAtom::ToNode(RegExpCompiler* compiler, RegExpNode* on_success)
TextElementVector* elms =
compiler->alloc()->newInfallible<TextElementVector>(*compiler->alloc());
elms->append(TextElement::Atom(this));
return compiler->alloc()->newInfallible<TextNode>(elms, on_success);
return compiler->alloc()->newInfallible<TextNode>(elms, compiler->read_backward(), on_success);
}
RegExpNode*
RegExpText::ToNode(RegExpCompiler* compiler, RegExpNode* on_success)
{
return compiler->alloc()->newInfallible<TextNode>(&elements_, on_success);
return compiler->alloc()->newInfallible<TextNode>(&elements_, compiler->read_backward(), on_success);
}
RegExpNode*
RegExpCharacterClass::ToNode(RegExpCompiler* compiler, RegExpNode* on_success)
{
return compiler->alloc()->newInfallible<TextNode>(this, on_success);
return compiler->alloc()->newInfallible<TextNode>(this, compiler->read_backward(), on_success);
}
RegExpNode*
@ -2003,7 +2011,8 @@ RegExpQuantifier::ToNode(int min,
alternation->AddAlternative(GuardedAlternative(body->ToNode(compiler, answer)));
}
answer = alternation;
if (not_at_start) alternation->set_not_at_start();
if (not_at_start && !compiler->read_backward())
alternation->set_not_at_start();
}
return answer;
}
@ -2015,8 +2024,9 @@ RegExpQuantifier::ToNode(int min,
int reg_ctr = needs_counter
? compiler->AllocateRegister()
: RegExpCompiler::kNoRegister;
LoopChoiceNode* center = alloc->newInfallible<LoopChoiceNode>(alloc, body->min_match() == 0);
if (not_at_start)
LoopChoiceNode* center = alloc->newInfallible<LoopChoiceNode>(alloc, body->min_match() == 0,
compiler->read_backward());
if (not_at_start && !compiler->read_backward())
center->set_not_at_start();
RegExpNode* loop_return = needs_counter
? static_cast<RegExpNode*>(ActionNode::IncrementRegister(reg_ctr, center))
@ -2092,7 +2102,7 @@ RegExpAssertion::ToNode(RegExpCompiler* compiler,
CharacterRange::AddClassEscape(alloc, 'n', newline_ranges);
RegExpCharacterClass* newline_atom = alloc->newInfallible<RegExpCharacterClass>('n');
TextNode* newline_matcher =
alloc->newInfallible<TextNode>(newline_atom,
alloc->newInfallible<TextNode>(newline_atom, false,
ActionNode::PositiveSubmatchSuccess(stack_pointer_register,
position_register,
0, // No captures inside.
@ -2124,6 +2134,7 @@ RegExpBackReference::ToNode(RegExpCompiler* compiler, RegExpNode* on_success)
{
return compiler->alloc()->newInfallible<BackReferenceNode>(RegExpCapture::StartRegister(index()),
RegExpCapture::EndRegister(index()),
compiler->read_backward(),
on_success);
}
@ -2134,7 +2145,7 @@ RegExpEmpty::ToNode(RegExpCompiler* compiler, RegExpNode* on_success)
}
RegExpNode*
RegExpLookahead::ToNode(RegExpCompiler* compiler, RegExpNode* on_success)
RegExpLookaround::ToNode(RegExpCompiler* compiler, RegExpNode* on_success)
{
int stack_pointer_register = compiler->AllocateRegister();
int position_register = compiler->AllocateRegister();
@ -2145,6 +2156,10 @@ RegExpLookahead::ToNode(RegExpCompiler* compiler, RegExpNode* on_success)
int register_start =
register_of_first_capture + capture_from_ * registers_per_capture;
RegExpNode* result;
bool was_reading_backward = compiler->read_backward();
compiler->set_read_backward(type() == LOOKBEHIND);
if (is_positive()) {
RegExpNode* bodyNode =
body()->ToNode(compiler,
@ -2153,37 +2168,39 @@ RegExpLookahead::ToNode(RegExpCompiler* compiler, RegExpNode* on_success)
register_count,
register_start,
on_success));
return ActionNode::BeginSubmatch(stack_pointer_register,
result = ActionNode::BeginSubmatch(stack_pointer_register,
position_register,
bodyNode);
} else {
// We use a ChoiceNode for a negative lookahead because it has most of
// the characteristics we need. It has the body of the lookahead as its
// first alternative and the expression after the lookahead of the second
// alternative. If the first alternative succeeds then the
// NegativeSubmatchSuccess will unwind the stack including everything the
// choice node set up and backtrack. If the first alternative fails then
// the second alternative is tried, which is exactly the desired result
// for a negative lookahead. The NegativeLookaheadChoiceNode is a special
// ChoiceNode that knows to ignore the first exit when calculating quick
// checks.
LifoAlloc* alloc = compiler->alloc();
RegExpNode* success =
alloc->newInfallible<NegativeSubmatchSuccess>(alloc,
stack_pointer_register,
position_register,
register_count,
register_start);
GuardedAlternative body_alt(body()->ToNode(compiler, success));
ChoiceNode* choice_node =
alloc->newInfallible<NegativeLookaheadChoiceNode>(alloc, body_alt, GuardedAlternative(on_success));
result = ActionNode::BeginSubmatch(stack_pointer_register,
position_register,
bodyNode);
choice_node);
}
// We use a ChoiceNode for a negative lookahead because it has most of
// the characteristics we need. It has the body of the lookahead as its
// first alternative and the expression after the lookahead of the second
// alternative. If the first alternative succeeds then the
// NegativeSubmatchSuccess will unwind the stack including everything the
// choice node set up and backtrack. If the first alternative fails then
// the second alternative is tried, which is exactly the desired result
// for a negative lookahead. The NegativeLookaheadChoiceNode is a special
// ChoiceNode that knows to ignore the first exit when calculating quick
// checks.
LifoAlloc* alloc = compiler->alloc();
RegExpNode* success =
alloc->newInfallible<NegativeSubmatchSuccess>(alloc,
stack_pointer_register,
position_register,
register_count,
register_start);
GuardedAlternative body_alt(body()->ToNode(compiler, success));
ChoiceNode* choice_node =
alloc->newInfallible<NegativeLookaheadChoiceNode>(alloc, body_alt, GuardedAlternative(on_success));
return ActionNode::BeginSubmatch(stack_pointer_register,
position_register,
choice_node);
compiler->set_read_backward(was_reading_backward);
return result;
}
RegExpNode*
@ -2198,8 +2215,14 @@ RegExpCapture::ToNode(RegExpTree* body,
RegExpCompiler* compiler,
RegExpNode* on_success)
{
MOZ_ASSERT(body);
int start_reg = RegExpCapture::StartRegister(index);
int end_reg = RegExpCapture::EndRegister(index);
if (compiler->read_backward()) {
// std::swap(start_reg, end_reg);
start_reg = RegExpCapture::EndRegister(index);
end_reg = RegExpCapture::StartRegister(index);
}
RegExpNode* store_end = ActionNode::StorePosition(end_reg, true, on_success);
RegExpNode* body_node = body->ToNode(compiler, store_end);
return ActionNode::StorePosition(start_reg, true, body_node);
@ -2210,8 +2233,15 @@ RegExpAlternative::ToNode(RegExpCompiler* compiler, RegExpNode* on_success)
{
const RegExpTreeVector& children = nodes();
RegExpNode* current = on_success;
for (int i = children.length() - 1; i >= 0; i--)
current = children[i]->ToNode(compiler, current);
if (compiler->read_backward()) {
for (int i = 0; i < children.length(); i++) {
current = children[i]->ToNode(compiler, current);
}
} else {
for (int i = children.length() - 1; i >= 0; i--) {
current = children[i]->ToNode(compiler, current);
}
}
return current;
}
@ -2764,7 +2794,6 @@ Trace::InvalidateCurrentCharacter()
void
Trace::AdvanceCurrentPositionInTrace(int by, RegExpCompiler* compiler)
{
MOZ_ASSERT(by > 0);
// We don't have an instruction for shifting the current character register
// down or for using a shifted value for anything so lets just forget that
// we preloaded any characters into it.
@ -3109,9 +3138,9 @@ AssertionNode::Emit(RegExpCompiler* compiler, Trace* trace)
return;
}
if (trace->at_start() == Trace::UNKNOWN) {
assembler->CheckNotAtStart(trace->backtrack());
assembler->CheckNotAtStart(trace->cp_offset(), trace->backtrack());
Trace at_start_trace = *trace;
at_start_trace.set_at_start(true);
at_start_trace.set_at_start(Trace::TRUE_VALUE);
on_success()->Emit(compiler, &at_start_trace);
return;
}
@ -3814,9 +3843,10 @@ TextNode::TextEmitPass(RegExpCompiler* compiler,
jit::Label* backtrack = trace->backtrack();
QuickCheckDetails* quick_check = trace->quick_check_performed();
int element_count = elements().length();
int backward_offset = read_backward() ? -Length() : 0;
for (int i = preloaded ? 0 : element_count - 1; i >= 0; i--) {
TextElement elm = elements()[i];
int cp_offset = trace->cp_offset() + elm.cp_offset();
int cp_offset = trace->cp_offset() + elm.cp_offset() + backward_offset;
if (elm.text_type() == TextElement::ATOM) {
const CharacterVector& quarks = elm.atom()->data();
for (int j = preloaded ? 0 : quarks.length() - 1; j >= 0; j--) {
@ -3844,11 +3874,12 @@ TextNode::TextEmitPass(RegExpCompiler* compiler,
break;
}
if (emit_function != nullptr) {
bool bounds_check = *checked_up_to < cp_offset + j || read_backward();
bool bound_checked = emit_function(compiler,
quarks[j],
backtrack,
cp_offset + j,
*checked_up_to < cp_offset + j,
bounds_check,
preloaded);
if (bound_checked) UpdateBoundsCheck(cp_offset + j, checked_up_to);
}
@ -3859,13 +3890,14 @@ TextNode::TextEmitPass(RegExpCompiler* compiler,
if (first_element_checked && i == 0) continue;
if (DeterminedAlready(quick_check, elm.cp_offset())) continue;
RegExpCharacterClass* cc = elm.char_class();
bool bounds_check = *checked_up_to < cp_offset || read_backward();
EmitCharClass(alloc(),
assembler,
cc,
ascii,
backtrack,
cp_offset,
*checked_up_to < cp_offset,
bounds_check,
preloaded);
UpdateBoundsCheck(cp_offset, checked_up_to);
}
@ -3945,8 +3977,11 @@ TextNode::Emit(RegExpCompiler* compiler, Trace* trace)
}
Trace successor_trace(*trace);
successor_trace.set_at_start(false);
successor_trace.AdvanceCurrentPositionInTrace(Length(), compiler);
// If we advance backward, we may end up at the start.
successor_trace.AdvanceCurrentPositionInTrace(
read_backward() ? -Length() : Length(), compiler);
successor_trace.set_at_start(read_backward() ? Trace::UNKNOWN
: Trace::FALSE_VALUE);
RecursionCheck rc(compiler);
on_success()->Emit(compiler, &successor_trace);
}
@ -4118,6 +4153,8 @@ ChoiceNode::CalculatePreloadCharacters(RegExpCompiler* compiler, int eats_at_lea
RegExpNode*
TextNode::GetSuccessorOfOmnivorousTextNode(RegExpCompiler* compiler)
{
if (read_backward()) return NULL;
if (elements().length() != 1)
return nullptr;
@ -4165,7 +4202,7 @@ ChoiceNode::GreedyLoopTextLengthForAlternative(GuardedAlternative* alternative)
SeqRegExpNode* seq_node = static_cast<SeqRegExpNode*>(node);
node = seq_node->on_success();
}
return length;
return read_backward() ? -length : length;
}
// Creates a list of AlternativeGenerations. If the list has a reasonable
@ -4240,7 +4277,7 @@ ChoiceNode::Emit(RegExpCompiler* compiler, Trace* trace)
jit::Label greedy_loop_label;
Trace counter_backtrack_trace;
counter_backtrack_trace.set_backtrack(&greedy_loop_label);
if (not_at_start()) counter_backtrack_trace.set_at_start(false);
if (not_at_start()) counter_backtrack_trace.set_at_start(Trace::FALSE_VALUE);
if (choice_count > 1 && text_length != kNodeIsTooComplexForGreedyLoops) {
// Here we have special handling for greedy loops containing only text nodes
@ -4256,7 +4293,7 @@ ChoiceNode::Emit(RegExpCompiler* compiler, Trace* trace)
current_trace = &counter_backtrack_trace;
jit::Label greedy_match_failed;
Trace greedy_match_trace;
if (not_at_start()) greedy_match_trace.set_at_start(false);
if (not_at_start()) greedy_match_trace.set_at_start(Trace::FALSE_VALUE);
greedy_match_trace.set_backtrack(&greedy_match_failed);
jit::Label loop_label;
macro_assembler->Bind(&loop_label);
@ -4605,11 +4642,14 @@ BackReferenceNode::Emit(RegExpCompiler* compiler, Trace* trace)
MOZ_ASSERT(start_reg_ + 1 == end_reg_);
if (compiler->ignore_case()) {
assembler->CheckNotBackReferenceIgnoreCase(start_reg_,
read_backward(),
trace->backtrack(),
compiler->unicode());
} else {
assembler->CheckNotBackReference(start_reg_, trace->backtrack());
assembler->CheckNotBackReference(start_reg_, read_backward(), trace->backtrack());
}
// We are going to advance backward, so we may end up at the start.
if (read_backward()) trace->set_at_start(Trace::UNKNOWN);
on_success()->Emit(compiler, trace);
}
@ -4977,7 +5017,6 @@ QuickCheckDetails::Clear()
void
QuickCheckDetails::Advance(int by, bool ascii)
{
MOZ_ASSERT(by >= 0);
if (by >= characters_) {
Clear();
return;

31
js/src/irregexp/RegExpEngine.h
View File

@ -119,7 +119,7 @@ InterpretCode(JSContext* cx, const uint8_t* byteCode, const CharT* chars, size_t
VISIT(Atom) \
VISIT(Quantifier) \
VISIT(Capture) \
VISIT(Lookahead) \
VISIT(Lookaround) \
VISIT(BackReference) \
VISIT(Empty) \
VISIT(Text)
@ -763,15 +763,19 @@ class TextNode : public SeqRegExpNode
{
public:
TextNode(TextElementVector* elements,
bool read_backward,
RegExpNode* on_success)
: SeqRegExpNode(on_success),
elements_(elements)
elements_(elements),
read_backward_(read_backward)
{}
TextNode(RegExpCharacterClass* that,
bool read_backward,
RegExpNode* on_success)
: SeqRegExpNode(on_success),
elements_(alloc()->newInfallible<TextElementVector>(*alloc()))
elements_(alloc()->newInfallible<TextElementVector>(*alloc())),
read_backward_(read_backward)
{
elements_->append(TextElement::CharClass(that));
}
@ -784,6 +788,7 @@ class TextNode : public SeqRegExpNode
int characters_filled_in,
bool not_at_start);
TextElementVector& elements() { return *elements_; }
bool read_backward() { return read_backward_; }
void MakeCaseIndependent(bool is_ascii, bool unicode);
virtual int GreedyLoopTextLength();
virtual RegExpNode* GetSuccessorOfOmnivorousTextNode(
@ -814,6 +819,7 @@ class TextNode : public SeqRegExpNode
int* checked_up_to);
int Length();
TextElementVector* elements_;
bool read_backward_;
};
class AssertionNode : public SeqRegExpNode
@ -882,15 +888,18 @@ class BackReferenceNode : public SeqRegExpNode
public:
BackReferenceNode(int start_reg,
int end_reg,
bool read_backward,
RegExpNode* on_success)
: SeqRegExpNode(on_success),
start_reg_(start_reg),
end_reg_(end_reg)
end_reg_(end_reg),
read_backward_(read_backward)
{}
virtual void Accept(NodeVisitor* visitor);
int start_register() { return start_reg_; }
int end_register() { return end_reg_; }
bool read_backward() { return read_backward_; }
virtual void Emit(RegExpCompiler* compiler, Trace* trace);
virtual int EatsAtLeast(int still_to_find,
int recursion_depth,
@ -909,6 +918,7 @@ class BackReferenceNode : public SeqRegExpNode
private:
int start_reg_;
int end_reg_;
bool read_backward_;
};
class EndNode : public RegExpNode
@ -1053,6 +1063,7 @@ class ChoiceNode : public RegExpNode
void set_being_calculated(bool b) { being_calculated_ = b; }
virtual bool try_to_emit_quick_check_for_alternative(int i) { return true; }
virtual RegExpNode* FilterASCII(int depth, bool ignore_case, bool unicode);
virtual bool read_backward() { return false; }
protected:
int GreedyLoopTextLengthForAlternative(GuardedAlternative* alternative);
@ -1111,11 +1122,13 @@ class NegativeLookaheadChoiceNode : public ChoiceNode
class LoopChoiceNode : public ChoiceNode
{
public:
explicit LoopChoiceNode(LifoAlloc* alloc, bool body_can_be_zero_length)
explicit LoopChoiceNode(LifoAlloc* alloc, bool body_can_be_zero_length,
bool read_backward)
: ChoiceNode(alloc, 2),
loop_node_(nullptr),
continue_node_(nullptr),
body_can_be_zero_length_(body_can_be_zero_length)
body_can_be_zero_length_(body_can_be_zero_length),
read_backward_(read_backward)
{}
void AddLoopAlternative(GuardedAlternative alt);
@ -1133,6 +1146,7 @@ class LoopChoiceNode : public ChoiceNode
RegExpNode* loop_node() { return loop_node_; }
RegExpNode* continue_node() { return continue_node_; }
bool body_can_be_zero_length() { return body_can_be_zero_length_; }
virtual bool read_backward() { return read_backward_; }
virtual void Accept(NodeVisitor* visitor);
virtual RegExpNode* FilterASCII(int depth, bool ignore_case, bool unicode);
@ -1147,6 +1161,7 @@ class LoopChoiceNode : public ChoiceNode
RegExpNode* loop_node_;
RegExpNode* continue_node_;
bool body_can_be_zero_length_;
bool read_backward_;
};
// Improve the speed that we scan for an initial point where a non-anchored
@ -1422,8 +1437,8 @@ class Trace
}
TriBool at_start() { return at_start_; }
void set_at_start(bool at_start) {
at_start_ = at_start ? TRUE_VALUE : FALSE_VALUE;
void set_at_start(TriBool at_start) {
at_start_ = at_start;
}
jit::Label* backtrack() { return backtrack_; }
jit::Label* loop_label() { return loop_label_; }

74
js/src/irregexp/RegExpInterpreter.cpp
View File

@ -222,8 +222,8 @@ irregexp::InterpretCode(JSContext* cx, const uint8_t* byteCode, const CharT* cha
}
break;
BYTECODE(LOAD_CURRENT_CHAR) {
size_t pos = current + (insn >> BYTECODE_SHIFT);
if (pos >= length) {
int pos = current + (insn >> BYTECODE_SHIFT);
if (pos >= (int)length || pos < 0) {
pc = byteCode + Load32Aligned(pc + 4);
} else {
current_char = chars[pos];
@ -238,8 +238,8 @@ irregexp::InterpretCode(JSContext* cx, const uint8_t* byteCode, const CharT* cha
break;
}
BYTECODE(LOAD_2_CURRENT_CHARS) {
size_t pos = current + (insn >> BYTECODE_SHIFT);
if (pos + 2 > length) {
int pos = current + (insn >> BYTECODE_SHIFT);
if (pos + 2 > (int)length || pos < 0) {
pc = byteCode + Load32Aligned(pc + 4);
} else {
CharT next = chars[pos + 1];
@ -425,6 +425,30 @@ irregexp::InterpretCode(JSContext* cx, const uint8_t* byteCode, const CharT* cha
pc += BC_CHECK_NOT_BACK_REF_LENGTH;
break;
}
BYTECODE(CHECK_NOT_BACK_REF_BACKWARD) {
int from = registers[insn >> BYTECODE_SHIFT];
int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
if (from < 0 || len <= 0) {
pc += BC_CHECK_NOT_BACK_REF_BACKWARD_LENGTH;
break;
}
if (int(current) - len < 0) {
pc = byteCode + Load32Aligned(pc + 4);
break;
} else {
int i;
for (i = 0; i < len; i++) {
if (chars[from + i] != chars[int(current) - len + i]) {
pc = byteCode + Load32Aligned(pc + 4);
break;
}
}
if (i < len) break;
current -= len;
}
pc += BC_CHECK_NOT_BACK_REF_BACKWARD_LENGTH;
break;
}
BYTECODE(CHECK_NOT_BACK_REF_NO_CASE) {
int from = registers[insn >> BYTECODE_SHIFT];
int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
@ -465,6 +489,46 @@ irregexp::InterpretCode(JSContext* cx, const uint8_t* byteCode, const CharT* cha
}
break;
}
BYTECODE(CHECK_NOT_BACK_REF_NO_CASE_BACKWARD) {
int from = registers[insn >> BYTECODE_SHIFT];
int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
if (from < 0 || len <= 0) {
pc += BC_CHECK_NOT_BACK_REF_NO_CASE_BACKWARD_LENGTH;
break;
}
if (int(current) - len < 0) {
pc = byteCode + Load32Aligned(pc + 4);
break;
}
if (CaseInsensitiveCompareStrings(chars + from, chars + int(current) - len, len * sizeof(CharT))) {
current -= len;
pc += BC_CHECK_NOT_BACK_REF_NO_CASE_BACKWARD_LENGTH;
} else {
pc = byteCode + Load32Aligned(pc + 4);
}
break;
}
BYTECODE(CHECK_NOT_BACK_REF_NO_CASE_BACKWARD_UNICODE) {
int from = registers[insn >> BYTECODE_SHIFT];
int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
if (from < 0 || len <= 0) {
pc += BC_CHECK_NOT_BACK_REF_NO_CASE_BACKWARD_LENGTH;
break;
}
if (int(current) - len < 0) {
pc = byteCode + Load32Aligned(pc + 4);
break;
}
if (CaseInsensitiveCompareUCStrings(chars + from, chars + int(current) - len, len * sizeof(CharT))) {
current -= len;
pc += BC_CHECK_NOT_BACK_REF_NO_CASE_BACKWARD_LENGTH;
} else {
pc = byteCode + Load32Aligned(pc + 4);
}
break;
}
BYTECODE(CHECK_AT_START)
if (current == 0)
pc = byteCode + Load32Aligned(pc + 4);
@ -472,7 +536,7 @@ irregexp::InterpretCode(JSContext* cx, const uint8_t* byteCode, const CharT* cha
pc += BC_CHECK_AT_START_LENGTH;
break;
BYTECODE(CHECK_NOT_AT_START)
if (current == 0)
if (current + (insn >> BYTECODE_SHIFT) == 0)
pc += BC_CHECK_NOT_AT_START_LENGTH;
else
pc = byteCode + Load32Aligned(pc + 4);

17
js/src/irregexp/RegExpMacroAssembler.cpp
View File

@ -226,32 +226,37 @@ InterpretedRegExpMacroAssembler::CheckGreedyLoop(jit::Label* on_tos_equals_curre
}
void
InterpretedRegExpMacroAssembler::CheckNotAtStart(jit::Label* on_not_at_start)
InterpretedRegExpMacroAssembler::CheckNotAtStart(int cp_offset, jit::Label* on_not_at_start)
{
Emit(BC_CHECK_NOT_AT_START, 0);
Emit(BC_CHECK_NOT_AT_START, cp_offset);
EmitOrLink(on_not_at_start);
}
void
InterpretedRegExpMacroAssembler::CheckNotBackReference(int start_reg, jit::Label* on_no_match)
InterpretedRegExpMacroAssembler::CheckNotBackReference(int start_reg, bool read_backward,
jit::Label* on_no_match)
{
MOZ_ASSERT(start_reg >= 0);
MOZ_ASSERT(start_reg <= kMaxRegister);
Emit(BC_CHECK_NOT_BACK_REF, start_reg);
Emit(read_backward ? BC_CHECK_NOT_BACK_REF_BACKWARD : BC_CHECK_NOT_BACK_REF,
start_reg);
EmitOrLink(on_no_match);
}
void
InterpretedRegExpMacroAssembler::CheckNotBackReferenceIgnoreCase(int start_reg,
bool read_backward,
jit::Label* on_no_match,
bool unicode)
{
MOZ_ASSERT(start_reg >= 0);
MOZ_ASSERT(start_reg <= kMaxRegister);
if (unicode)
Emit(BC_CHECK_NOT_BACK_REF_NO_CASE_UNICODE, start_reg);
Emit(read_backward ? BC_CHECK_NOT_BACK_REF_NO_CASE_BACKWARD_UNICODE : BC_CHECK_NOT_BACK_REF_NO_CASE_UNICODE,
start_reg);
else
Emit(BC_CHECK_NOT_BACK_REF_NO_CASE, start_reg);
Emit(read_backward ? BC_CHECK_NOT_BACK_REF_NO_CASE_BACKWARD : BC_CHECK_NOT_BACK_REF_NO_CASE,
start_reg);
EmitOrLink(on_no_match);
}

15
js/src/irregexp/RegExpMacroAssembler.h
View File

@ -110,10 +110,10 @@ class MOZ_STACK_CLASS RegExpMacroAssembler
virtual void CheckCharacterGT(char16_t limit, jit::Label* on_greater) = 0;
virtual void CheckCharacterLT(char16_t limit, jit::Label* on_less) = 0;
virtual void CheckGreedyLoop(jit::Label* on_tos_equals_current_position) = 0;
virtual void CheckNotAtStart(jit::Label* on_not_at_start) = 0;
virtual void CheckNotBackReference(int start_reg, jit::Label* on_no_match) = 0;
virtual void CheckNotBackReferenceIgnoreCase(int start_reg, jit::Label* on_no_match,
bool unicode) = 0;
virtual void CheckNotAtStart(int cp_offset, jit::Label* on_not_at_start) = 0;
virtual void CheckNotBackReference(int start_reg, bool read_backward, jit::Label* on_no_match) = 0;
virtual void CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
jit::Label* on_no_match, bool unicode) = 0;
// Check the current character for a match with a literal character. If we
// fail to match then goto the on_failure label. End of input always
@ -245,9 +245,10 @@ class MOZ_STACK_CLASS InterpretedRegExpMacroAssembler final : public RegExpMacro
void CheckCharacterGT(char16_t limit, jit::Label* on_greater);
void CheckCharacterLT(char16_t limit, jit::Label* on_less);
void CheckGreedyLoop(jit::Label* on_tos_equals_current_position);
void CheckNotAtStart(jit::Label* on_not_at_start);
void CheckNotBackReference(int start_reg, jit::Label* on_no_match);
void CheckNotBackReferenceIgnoreCase(int start_reg, jit::Label* on_no_match, bool unicode);
void CheckNotAtStart(int cp_offset, jit::Label* on_not_at_start);
void CheckNotBackReference(int start_reg, bool read_backward, jit::Label* on_no_match);
void CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
jit::Label* on_no_match, bool unicode);
void CheckNotCharacter(unsigned c, jit::Label* on_not_equal);
void CheckNotCharacterAfterAnd(unsigned c, unsigned and_with, jit::Label* on_not_equal);
void CheckNotCharacterAfterMinusAnd(char16_t c, char16_t minus, char16_t and_with,

130
js/src/irregexp/RegExpParser.cpp
View File

@ -227,6 +227,7 @@ RegExpParser<CharT>::RegExpParser(frontend::TokenStream& ts, LifoAlloc* alloc,
alloc(alloc),
captures_(nullptr),
next_pos_(chars),
captures_started_(0),
end_(end),
current_(kEndMarker),
capture_count_(0),
@ -418,7 +419,8 @@ RangeAtom(LifoAlloc* alloc, char16_t from, char16_t to)
static inline RegExpTree*
NegativeLookahead(LifoAlloc* alloc, char16_t from, char16_t to)
{
return alloc->newInfallible<RegExpLookahead>(RangeAtom(alloc, from, to), false, 0, 0);
return alloc->newInfallible<RegExpLookaround>(RangeAtom(alloc, from, to), false,
0, 0, RegExpLookaround::LOOKAHEAD);
}
static bool
@ -1213,6 +1215,38 @@ RegExpParser<CharT>::ParseBackReferenceIndex(int* index_out)
return true;
}
template <typename CharT>
RegExpCapture*
RegExpParser<CharT>::GetCapture(int index) {
// The index for the capture groups are one-based. Its index in the list is
// zero-based.
int known_captures =
is_scanned_for_captures_ ? capture_count_ : captures_started_;
MOZ_ASSERT(index <= known_captures);
if (captures_ == NULL) {
captures_ = alloc->newInfallible<RegExpCaptureVector>(*alloc);
}
while ((int)captures_->length() < known_captures) {
RegExpCapture* capture = alloc->newInfallible<RegExpCapture>(nullptr, captures_->length() + 1);
captures_->append(capture);
}
return (*captures_)[index - 1];
}
template <typename CharT>
bool
RegExpParser<CharT>::RegExpParserState::IsInsideCaptureGroup(int index) {
for (RegExpParserState* s = this; s != NULL; s = s->previous_state()) {
if (s->group_type() != CAPTURE) continue;
// Return true if we found the matching capture index.
if (index == s->capture_index()) return true;
// Abort if index is larger than what has been parsed up till this state.
if (index > s->capture_index()) return false;
}
return false;
}
// QuantifierPrefix ::
// { DecimalDigits }
// { DecimalDigits , }
@ -1423,24 +1457,24 @@ RegExpTree*
RegExpParser<CharT>::ParseDisjunction()
{
// Used to store current state while parsing subexpressions.
RegExpParserState initial_state(alloc, nullptr, INITIAL, 0);
RegExpParserState* stored_state = &initial_state;
RegExpParserState initial_state(alloc, nullptr, INITIAL, RegExpLookaround::LOOKAHEAD, 0);
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 (stored_state->IsSubexpression()) {
if (state->IsSubexpression()) {
// Inside a parenthesized group when hitting end of input.
return ReportError(JSMSG_MISSING_PAREN);
}
MOZ_ASSERT(INITIAL == stored_state->group_type());
MOZ_ASSERT(INITIAL == state->group_type());
// Parsing completed successfully.
return builder->ToRegExp();
case ')': {
if (!stored_state->IsSubexpression())
if (!state->IsSubexpression())
return ReportError(JSMSG_UNMATCHED_RIGHT_PAREN);
MOZ_ASSERT(INITIAL != stored_state->group_type());
MOZ_ASSERT(INITIAL != state->group_type());
Advance();
// End disjunction parsing and convert builder content to new single
@ -1449,29 +1483,30 @@ RegExpParser<CharT>::ParseDisjunction()
int end_capture_index = captures_started();
int capture_index = stored_state->capture_index();
SubexpressionType group_type = stored_state->group_type();
// Restore previous state.
stored_state = stored_state->previous_state();
builder = stored_state->builder();
int capture_index = state->capture_index();
SubexpressionType group_type = state->group_type();
// Build result of subexpression.
if (group_type == CAPTURE) {
RegExpCapture* capture = alloc->newInfallible<RegExpCapture>(body, capture_index);
(*captures_)[capture_index - 1] = capture;
RegExpCapture* capture = GetCapture(capture_index);
capture->set_body(body);
body = capture;
} else if (group_type != GROUPING) {
MOZ_ASSERT(group_type == POSITIVE_LOOKAHEAD ||
group_type == NEGATIVE_LOOKAHEAD);
bool is_positive = (group_type == POSITIVE_LOOKAHEAD);
body = alloc->newInfallible<RegExpLookahead>(body,
MOZ_ASSERT(group_type == POSITIVE_LOOKAROUND ||
group_type == NEGATIVE_LOOKAROUND);
bool is_positive = (group_type == POSITIVE_LOOKAROUND);
body = alloc->newInfallible<RegExpLookaround>(body,
is_positive,
end_capture_index - capture_index,
capture_index);
capture_index,
state->lookaround_type());
}
// Restore previous state.
state = state->previous_state();
builder = state->builder();
builder->AddAtom(body);
if (unicode_ && (group_type == POSITIVE_LOOKAHEAD || group_type == NEGATIVE_LOOKAHEAD))
if (unicode_ && (group_type == POSITIVE_LOOKAROUND || group_type == NEGATIVE_LOOKAROUND))
continue;
// For compatability with JSC and ES3, we allow quantifiers after
// lookaheads, and break in all cases.
@ -1519,6 +1554,7 @@ RegExpParser<CharT>::ParseDisjunction()
}
case '(': {
SubexpressionType subexpr_type = CAPTURE;
RegExpLookaround::Type lookaround_type = state->lookaround_type();
Advance();
if (current() == '?') {
switch (Next()) {
@ -1526,26 +1562,39 @@ RegExpParser<CharT>::ParseDisjunction()
subexpr_type = GROUPING;
break;
case '=':
subexpr_type = POSITIVE_LOOKAHEAD;
lookaround_type = RegExpLookaround::LOOKAHEAD;
subexpr_type = POSITIVE_LOOKAROUND;
break;
case '!':
subexpr_type = NEGATIVE_LOOKAHEAD;
lookaround_type = RegExpLookaround::LOOKAHEAD;
subexpr_type = NEGATIVE_LOOKAROUND;
break;
case '<':
Advance();
lookaround_type = RegExpLookaround::LOOKBEHIND;
if (Next() == '=') {
subexpr_type = POSITIVE_LOOKAROUND;
break;
} else if (Next() == '!') {
subexpr_type = NEGATIVE_LOOKAROUND;
break;
}
// We didn't get a positive or negative after '<'.
// That's an error.
return ReportError(JSMSG_INVALID_GROUP);
default:
return ReportError(JSMSG_INVALID_GROUP);
}
Advance(2);
} else {
if (captures_ == nullptr)
captures_ = alloc->newInfallible<RegExpCaptureVector>(*alloc);
if (captures_started() >= kMaxCaptures)
return ReportError(JSMSG_TOO_MANY_PARENS);
captures_->append((RegExpCapture*) nullptr);
captures_started_++;
}
// Store current state and begin new disjunction parsing.
stored_state = alloc->newInfallible<RegExpParserState>(alloc, stored_state, subexpr_type,
captures_started());
builder = stored_state->builder();
state = alloc->newInfallible<RegExpParserState>(alloc, state, subexpr_type,
lookaround_type, captures_started_);
builder = state->builder();
continue;
}
case '[': {
@ -1600,19 +1649,18 @@ RegExpParser<CharT>::ParseDisjunction()
case '7': case '8': case '9': {
int index = 0;
if (ParseBackReferenceIndex(&index)) {
RegExpCapture* capture = nullptr;
if (captures_ != nullptr && index <= (int) captures_->length()) {
capture = (*captures_)[index - 1];
if (state->IsInsideCaptureGroup(index)) {
// The backreference is inside the capture group it refers to.
// Nothing can possibly have been captured yet.
builder->AddEmpty();
} else {
RegExpCapture* capture = GetCapture(index);
RegExpTree* atom = alloc->newInfallible<RegExpBackReference>(capture);
if (unicode_)
builder->AddAtom(UnicodeBackReferenceAtom(alloc, atom));
else
builder->AddAtom(atom);
}
if (capture == nullptr) {
builder->AddEmpty();
break;
}
RegExpTree* atom = alloc->newInfallible<RegExpBackReference>(capture);
if (unicode_)
builder->AddAtom(UnicodeBackReferenceAtom(alloc, atom));
else
builder->AddAtom(atom);
break;
}
if (unicode_)

19
js/src/irregexp/RegExpParser.h
View File

@ -229,7 +229,7 @@ class RegExpParser
bool simple() { return simple_; }
bool contains_anchor() { return contains_anchor_; }
void set_contains_anchor() { contains_anchor_ = true; }
int captures_started() { return captures_ == nullptr ? 0 : captures_->length(); }
int captures_started() { return captures_started_; }
const CharT* position() { return next_pos_ - 1; }
static const int kMaxCaptures = 1 << 16;
@ -239,8 +239,8 @@ class RegExpParser
enum SubexpressionType {
INITIAL,
CAPTURE, // All positive values represent captures.
POSITIVE_LOOKAHEAD,
NEGATIVE_LOOKAHEAD,
POSITIVE_LOOKAROUND,
NEGATIVE_LOOKAROUND,
GROUPING
};
@ -249,10 +249,12 @@ class RegExpParser
RegExpParserState(LifoAlloc* alloc,
RegExpParserState* previous_state,
SubexpressionType group_type,
RegExpLookaround::Type lookaround_type,
int disjunction_capture_index)
: previous_state_(previous_state),
builder_(alloc->newInfallible<RegExpBuilder>(alloc)),
group_type_(group_type),
lookaround_type_(lookaround_type),
disjunction_capture_index_(disjunction_capture_index)
{}
// Parser state of containing expression, if any.
@ -262,11 +264,16 @@ class RegExpParser
RegExpBuilder* builder() { return builder_; }
// Type of regexp being parsed (parenthesized group or entire regexp).
SubexpressionType group_type() { return group_type_; }
// Lookahead or Lookbehind.
RegExpLookaround::Type lookaround_type() { 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() { return disjunction_capture_index_; }
// Check whether the parser is inside a capture group with the given index.
bool IsInsideCaptureGroup(int index);
private:
// Linked list implementation of stack of states.
RegExpParserState* previous_state_;
@ -274,10 +281,15 @@ class RegExpParser
RegExpBuilder* builder_;
// Stored disjunction type (capture, look-ahead or grouping), if any.
SubexpressionType group_type_;
// Stored read direction.
RegExpLookaround::Type lookaround_type_;
// Stored disjunction's capture index (if any).
int disjunction_capture_index_;
};
// Return the 1-indexed RegExpCapture object, allocate if necessary.
RegExpCapture* GetCapture(int index);
widechar current() { return current_; }
bool has_more() { return has_more_; }
bool has_next() { return next_pos_ < end_; }
@ -294,6 +306,7 @@ class RegExpParser
const CharT* next_pos_;
const CharT* end_;
widechar current_;
int captures_started_;
// The capture count is only valid after we have scanned for captures.
int capture_count_;
bool has_more_;