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49f4c39d6d
v8/src/ast.cc
kmillikin@chromium.org 49f4c39d6d Deoptimize to the proper target after assignment side effects. 
This fixes V8 issue 989.

Before, assignments used the AST ID of the assignment expression to
mark the side effect of the store, which became a target for
deoptimization bailout for code after the assignment.  In effect
contexts this environment included the value of the assignment, which
was unexpected by the unoptimized code.

Now we introduce a new assignment ID for AST node types that include
an assignment (Assignment, CountOperation, and ForInStatement) and use
it for the side effect of the store.

Review URL: http://codereview.chromium.org/5682010

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5990 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2010-12-13 16:29:47 +00:00

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// Copyright 2010 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "v8.h"
#include "ast.h"
#include "jump-target-inl.h"
#include "parser.h"
#include "scopes.h"
#include "string-stream.h"
namespace v8 {
namespace internal {
unsigned AstNode::current_id_ = 0;
unsigned AstNode::count_ = 0;
VariableProxySentinel VariableProxySentinel::this_proxy_(true);
VariableProxySentinel VariableProxySentinel::identifier_proxy_(false);
ValidLeftHandSideSentinel ValidLeftHandSideSentinel::instance_;
Property Property::this_property_(VariableProxySentinel::this_proxy(), NULL, 0);
Call Call::sentinel_(NULL, NULL, 0);
// ----------------------------------------------------------------------------
// All the Accept member functions for each syntax tree node type.
void Slot::Accept(AstVisitor* v) { v->VisitSlot(this); }
#define DECL_ACCEPT(type) \
void type::Accept(AstVisitor* v) { v->Visit##type(this); }
AST_NODE_LIST(DECL_ACCEPT)
#undef DECL_ACCEPT
// ----------------------------------------------------------------------------
// Implementation of other node functionality.
Assignment* ExpressionStatement::StatementAsSimpleAssignment() {
return (expression()->AsAssignment() != NULL &&
!expression()->AsAssignment()->is_compound())
? expression()->AsAssignment()
: NULL;
}
CountOperation* ExpressionStatement::StatementAsCountOperation() {
return expression()->AsCountOperation();
}
VariableProxy::VariableProxy(Variable* var)
: name_(var->name()),
var_(NULL), // Will be set by the call to BindTo.
is_this_(var->is_this()),
inside_with_(false),
is_trivial_(false) {
BindTo(var);
}
VariableProxy::VariableProxy(Handle<String> name,
bool is_this,
bool inside_with)
: name_(name),
var_(NULL),
is_this_(is_this),
inside_with_(inside_with),
is_trivial_(false) {
// names must be canonicalized for fast equality checks
ASSERT(name->IsSymbol());
}
VariableProxy::VariableProxy(bool is_this)
: var_(NULL),
is_this_(is_this),
inside_with_(false),
is_trivial_(false) {
}
void VariableProxy::BindTo(Variable* var) {
ASSERT(var_ == NULL); // must be bound only once
ASSERT(var != NULL); // must bind
ASSERT((is_this() && var->is_this()) || name_.is_identical_to(var->name()));
// Ideally CONST-ness should match. However, this is very hard to achieve
// because we don't know the exact semantics of conflicting (const and
// non-const) multiple variable declarations, const vars introduced via
// eval() etc. Const-ness and variable declarations are a complete mess
// in JS. Sigh...
var_ = var;
var->set_is_used(true);
}
Assignment::Assignment(Token::Value op,
Expression* target,
Expression* value,
int pos)
: op_(op),
target_(target),
value_(value),
pos_(pos),
binary_operation_(NULL),
compound_load_id_(kNoNumber),
assignment_id_(GetNextId()),
block_start_(false),
block_end_(false),
is_monomorphic_(false),
receiver_types_(NULL) {
ASSERT(Token::IsAssignmentOp(op));
if (is_compound()) {
binary_operation_ =
new BinaryOperation(binary_op(), target, value, pos + 1);
compound_load_id_ = GetNextId();
}
}
Token::Value Assignment::binary_op() const {
switch (op_) {
case Token::ASSIGN_BIT_OR: return Token::BIT_OR;
case Token::ASSIGN_BIT_XOR: return Token::BIT_XOR;
case Token::ASSIGN_BIT_AND: return Token::BIT_AND;
case Token::ASSIGN_SHL: return Token::SHL;
case Token::ASSIGN_SAR: return Token::SAR;
case Token::ASSIGN_SHR: return Token::SHR;
case Token::ASSIGN_ADD: return Token::ADD;
case Token::ASSIGN_SUB: return Token::SUB;
case Token::ASSIGN_MUL: return Token::MUL;
case Token::ASSIGN_DIV: return Token::DIV;
case Token::ASSIGN_MOD: return Token::MOD;
default: UNREACHABLE();
}
return Token::ILLEGAL;
}
bool FunctionLiteral::AllowsLazyCompilation() {
return scope()->AllowsLazyCompilation();
}
bool FunctionLiteral::AllowOptimize() {
// We can't deal with heap-allocated locals.
return scope()->num_heap_slots() == 0;
}
ObjectLiteral::Property::Property(Literal* key, Expression* value) {
emit_store_ = true;
key_ = key;
value_ = value;
Object* k = *key->handle();
if (k->IsSymbol() && Heap::Proto_symbol()->Equals(String::cast(k))) {
kind_ = PROTOTYPE;
} else if (value_->AsMaterializedLiteral() != NULL) {
kind_ = MATERIALIZED_LITERAL;
} else if (value_->AsLiteral() != NULL) {
kind_ = CONSTANT;
} else {
kind_ = COMPUTED;
}
}
ObjectLiteral::Property::Property(bool is_getter, FunctionLiteral* value) {
emit_store_ = true;
key_ = new Literal(value->name());
value_ = value;
kind_ = is_getter ? GETTER : SETTER;
}
bool ObjectLiteral::Property::IsCompileTimeValue() {
return kind_ == CONSTANT ||
(kind_ == MATERIALIZED_LITERAL &&
CompileTimeValue::IsCompileTimeValue(value_));
}
void ObjectLiteral::Property::set_emit_store(bool emit_store) {
emit_store_ = emit_store;
}
bool ObjectLiteral::Property::emit_store() {
return emit_store_;
}
bool IsEqualString(void* first, void* second) {
Handle<String> h1(reinterpret_cast<String**>(first));
Handle<String> h2(reinterpret_cast<String**>(second));
return (*h1)->Equals(*h2);
}
bool IsEqualSmi(void* first, void* second) {
Handle<Smi> h1(reinterpret_cast<Smi**>(first));
Handle<Smi> h2(reinterpret_cast<Smi**>(second));
return (*h1)->value() == (*h2)->value();
}
void ObjectLiteral::CalculateEmitStore() {
HashMap properties(&IsEqualString);
HashMap elements(&IsEqualSmi);
for (int i = this->properties()->length() - 1; i >= 0; i--) {
ObjectLiteral::Property* property = this->properties()->at(i);
Literal* literal = property->key();
Handle<Object> handle = literal->handle();
if (handle->IsNull()) {
continue;
}
uint32_t hash;
HashMap* table;
void* key;
uint32_t index;
if (handle->IsSymbol()) {
Handle<String> name(String::cast(*handle));
ASSERT(!name->AsArrayIndex(&index));
key = name.location();
hash = name->Hash();
table = &properties;
} else if (handle->ToArrayIndex(&index)) {
key = handle.location();
hash = index;
table = &elements;
} else {
ASSERT(handle->IsNumber());
double num = handle->Number();
char arr[100];
Vector<char> buffer(arr, ARRAY_SIZE(arr));
const char* str = DoubleToCString(num, buffer);
Handle<String> name = Factory::NewStringFromAscii(CStrVector(str));
key = name.location();
hash = name->Hash();
table = &properties;
}
// If the key of a computed property is in the table, do not emit
// a store for the property later.
if (property->kind() == ObjectLiteral::Property::COMPUTED) {
if (table->Lookup(literal, hash, false) != NULL) {
property->set_emit_store(false);
}
}
// Add key to the table.
table->Lookup(literal, hash, true);
}
}
void TargetCollector::AddTarget(BreakTarget* target) {
// Add the label to the collector, but discard duplicates.
int length = targets_->length();
for (int i = 0; i < length; i++) {
if (targets_->at(i) == target) return;
}
targets_->Add(target);
}
bool Expression::GuaranteedSmiResult() {
BinaryOperation* node = AsBinaryOperation();
if (node == NULL) return false;
Token::Value op = node->op();
switch (op) {
case Token::COMMA:
case Token::OR:
case Token::AND:
case Token::ADD:
case Token::SUB:
case Token::MUL:
case Token::DIV:
case Token::MOD:
case Token::BIT_XOR:
case Token::SHL:
return false;
break;
case Token::BIT_OR:
case Token::BIT_AND: {
Literal* left = node->left()->AsLiteral();
Literal* right = node->right()->AsLiteral();
if (left != NULL && left->handle()->IsSmi()) {
int value = Smi::cast(*left->handle())->value();
if (op == Token::BIT_OR && ((value & 0xc0000000) == 0xc0000000)) {
// Result of bitwise or is always a negative Smi.
return true;
}
if (op == Token::BIT_AND && ((value & 0xc0000000) == 0)) {
// Result of bitwise and is always a positive Smi.
return true;
}
}
if (right != NULL && right->handle()->IsSmi()) {
int value = Smi::cast(*right->handle())->value();
if (op == Token::BIT_OR && ((value & 0xc0000000) == 0xc0000000)) {
// Result of bitwise or is always a negative Smi.
return true;
}
if (op == Token::BIT_AND && ((value & 0xc0000000) == 0)) {
// Result of bitwise and is always a positive Smi.
return true;
}
}
return false;
break;
}
case Token::SAR:
case Token::SHR: {
Literal* right = node->right()->AsLiteral();
if (right != NULL && right->handle()->IsSmi()) {
int value = Smi::cast(*right->handle())->value();
if ((value & 0x1F) > 1 ||
(op == Token::SAR && (value & 0x1F) == 1)) {
return true;
}
}
return false;
break;
}
default:
UNREACHABLE();
break;
}
return false;
}
void Expression::CopyAnalysisResultsFrom(Expression* other) {
bitfields_ = other->bitfields_;
type_ = other->type_;
}
bool UnaryOperation::ResultOverwriteAllowed() {
switch (op_) {
case Token::BIT_NOT:
case Token::SUB:
return true;
default:
return false;
}
}
bool BinaryOperation::ResultOverwriteAllowed() {
switch (op_) {
case Token::COMMA:
case Token::OR:
case Token::AND:
return false;
case Token::BIT_OR:
case Token::BIT_XOR:
case Token::BIT_AND:
case Token::SHL:
case Token::SAR:
case Token::SHR:
case Token::ADD:
case Token::SUB:
case Token::MUL:
case Token::DIV:
case Token::MOD:
return true;
default:
UNREACHABLE();
}
return false;
}
BinaryOperation::BinaryOperation(Assignment* assignment) {
ASSERT(assignment->is_compound());
op_ = assignment->binary_op();
left_ = assignment->target();
right_ = assignment->value();
pos_ = assignment->position();
CopyAnalysisResultsFrom(assignment);
}
// ----------------------------------------------------------------------------
// Inlining support
bool Block::IsInlineable() const {
const int count = statements_.length();
for (int i = 0; i < count; ++i) {
if (!statements_[i]->IsInlineable()) return false;
}
return true;
}
bool ExpressionStatement::IsInlineable() const {
return expression()->IsInlineable();
}
bool IfStatement::IsInlineable() const {
return condition()->IsInlineable() && then_statement()->IsInlineable() &&
else_statement()->IsInlineable();
}
bool ReturnStatement::IsInlineable() const {
return expression()->IsInlineable();
}
bool Conditional::IsInlineable() const {
return condition()->IsInlineable() && then_expression()->IsInlineable() &&
else_expression()->IsInlineable();
}
bool VariableProxy::IsInlineable() const {
return var()->is_global() || var()->IsStackAllocated();
}
bool Assignment::IsInlineable() const {
return target()->IsInlineable() && value()->IsInlineable();
}
bool Property::IsInlineable() const {
return obj()->IsInlineable() && key()->IsInlineable();
}
bool Call::IsInlineable() const {
if (!expression()->IsInlineable()) return false;
const int count = arguments()->length();
for (int i = 0; i < count; ++i) {
if (!arguments()->at(i)->IsInlineable()) return false;
}
return true;
}
bool CallNew::IsInlineable() const {
if (!expression()->IsInlineable()) return false;
const int count = arguments()->length();
for (int i = 0; i < count; ++i) {
if (!arguments()->at(i)->IsInlineable()) return false;
}
return true;
}
bool CallRuntime::IsInlineable() const {
const int count = arguments()->length();
for (int i = 0; i < count; ++i) {
if (!arguments()->at(i)->IsInlineable()) return false;
}
return true;
}
bool UnaryOperation::IsInlineable() const {
return expression()->IsInlineable();
}
bool BinaryOperation::IsInlineable() const {
return left()->IsInlineable() && right()->IsInlineable();
}
bool CompareOperation::IsInlineable() const {
return left()->IsInlineable() && right()->IsInlineable();
}
bool CompareToNull::IsInlineable() const {
return expression()->IsInlineable();
}
bool CountOperation::IsInlineable() const {
return expression()->IsInlineable();
}
// ----------------------------------------------------------------------------
// Recording of type feedback
void Property::RecordTypeFeedback(TypeFeedbackOracle* oracle) {
// Record type feedback from the oracle in the AST.
is_monomorphic_ = oracle->LoadIsMonomorphic(this);
if (key()->IsPropertyName()) {
if (oracle->LoadIsBuiltin(this, Builtins::LoadIC_ArrayLength)) {
is_array_length_ = true;
} else {
Literal* lit_key = key()->AsLiteral();
ASSERT(lit_key != NULL && lit_key->handle()->IsString());
Handle<String> name = Handle<String>::cast(lit_key->handle());
ZoneMapList* types = oracle->LoadReceiverTypes(this, name);
receiver_types_ = types;
}
} else if (is_monomorphic_) {
monomorphic_receiver_type_ = oracle->LoadMonomorphicReceiverType(this);
}
}
void Assignment::RecordTypeFeedback(TypeFeedbackOracle* oracle) {
Property* prop = target()->AsProperty();
ASSERT(prop != NULL);
is_monomorphic_ = oracle->StoreIsMonomorphic(this);
if (prop->key()->IsPropertyName()) {
Literal* lit_key = prop->key()->AsLiteral();
ASSERT(lit_key != NULL && lit_key->handle()->IsString());
Handle<String> name = Handle<String>::cast(lit_key->handle());
ZoneMapList* types = oracle->StoreReceiverTypes(this, name);
receiver_types_ = types;
} else if (is_monomorphic_) {
// Record receiver type for monomorphic keyed loads.
monomorphic_receiver_type_ = oracle->StoreMonomorphicReceiverType(this);
}
}
void CaseClause::RecordTypeFeedback(TypeFeedbackOracle* oracle) {
TypeInfo info = oracle->SwitchType(this);
if (info.IsSmi()) {
compare_type_ = SMI_ONLY;
} else if (info.IsNonPrimitive()) {
compare_type_ = OBJECT_ONLY;
} else {
ASSERT(compare_type_ == NONE);
}
}
static bool CallWithoutIC(Handle<JSFunction> target, int arity) {
if (target->NeedsArgumentsAdaption()) {
// If the number of formal parameters of the target function
// does not match the number of arguments we're passing, we
// don't want to deal with it.
return target->shared()->formal_parameter_count() == arity;
} else {
// If the target doesn't need arguments adaption, we can call
// it directly, but we avoid to do so if it has a custom call
// generator, because that is likely to generate better code.
return !target->shared()->HasCustomCallGenerator();
}
}
bool Call::ComputeTarget(Handle<Map> type, Handle<String> name) {
holder_ = Handle<JSObject>::null();
while (true) {
LookupResult lookup;
type->LookupInDescriptors(NULL, *name, &lookup);
// If the function wasn't found directly in the map, we start
// looking upwards through the prototype chain.
if (!lookup.IsFound() && type->prototype()->IsJSObject()) {
holder_ = Handle<JSObject>(JSObject::cast(type->prototype()));
type = Handle<Map>(holder()->map());
} else if (lookup.IsProperty() && lookup.type() == CONSTANT_FUNCTION) {
target_ = Handle<JSFunction>(lookup.GetConstantFunctionFromMap(*type));
return CallWithoutIC(target_, arguments()->length());
} else {
return false;
}
}
}
bool Call::ComputeGlobalTarget(Handle<GlobalObject> global,
Handle<String> name) {
target_ = Handle<JSFunction>::null();
cell_ = Handle<JSGlobalPropertyCell>::null();
LookupResult lookup;
global->Lookup(*name, &lookup);
if (lookup.IsProperty() && lookup.type() == NORMAL) {
cell_ = Handle<JSGlobalPropertyCell>(global->GetPropertyCell(&lookup));
if (cell_->value()->IsJSFunction()) {
Handle<JSFunction> candidate(JSFunction::cast(cell_->value()));
// If the function is in new space we assume it's more likely to
// change and thus prefer the general IC code.
if (!Heap::InNewSpace(*candidate)
&& CallWithoutIC(candidate, arguments()->length())) {
target_ = candidate;
return true;
}
}
}
return false;
}
void Call::RecordTypeFeedback(TypeFeedbackOracle* oracle) {
Property* property = expression()->AsProperty();
ASSERT(property != NULL);
// Specialize for the receiver types seen at runtime.
Literal* key = property->key()->AsLiteral();
ASSERT(key != NULL && key->handle()->IsString());
Handle<String> name = Handle<String>::cast(key->handle());
receiver_types_ = oracle->CallReceiverTypes(this, name);
#ifdef DEBUG
if (FLAG_enable_slow_asserts) {
if (receiver_types_ != NULL) {
int length = receiver_types_->length();
for (int i = 0; i < length; i++) {
Handle<Map> map = receiver_types_->at(i);
ASSERT(!map.is_null() && *map != NULL);
}
}
}
#endif
if (receiver_types_ != NULL && receiver_types_->length() > 0) {
Handle<Map> type = receiver_types_->at(0);
is_monomorphic_ = oracle->CallIsMonomorphic(this);
if (is_monomorphic_) is_monomorphic_ = ComputeTarget(type, name);
}
}
void BinaryOperation::RecordTypeFeedback(TypeFeedbackOracle* oracle) {
TypeInfo left = oracle->BinaryType(this, TypeFeedbackOracle::LEFT);
TypeInfo right = oracle->BinaryType(this, TypeFeedbackOracle::RIGHT);
is_smi_only_ = left.IsSmi() && right.IsSmi();
}
void CompareOperation::RecordTypeFeedback(TypeFeedbackOracle* oracle) {
TypeInfo left = oracle->CompareType(this, TypeFeedbackOracle::LEFT);
TypeInfo right = oracle->CompareType(this, TypeFeedbackOracle::RIGHT);
if (left.IsSmi() && right.IsSmi()) {
compare_type_ = SMI_ONLY;
} else if (left.IsNonPrimitive() && right.IsNonPrimitive()) {
compare_type_ = OBJECT_ONLY;
} else {
ASSERT(compare_type_ == NONE);
}
}
// ----------------------------------------------------------------------------
// Implementation of AstVisitor
bool AstVisitor::CheckStackOverflow() {
if (stack_overflow_) return true;
StackLimitCheck check;
if (!check.HasOverflowed()) return false;
return (stack_overflow_ = true);
}
void AstVisitor::VisitDeclarations(ZoneList<Declaration*>* declarations) {
for (int i = 0; i < declarations->length(); i++) {
Visit(declarations->at(i));
}
}
void AstVisitor::VisitStatements(ZoneList<Statement*>* statements) {
for (int i = 0; i < statements->length(); i++) {
Visit(statements->at(i));
}
}
void AstVisitor::VisitExpressions(ZoneList<Expression*>* expressions) {
for (int i = 0; i < expressions->length(); i++) {
// The variable statement visiting code may pass NULL expressions
// to this code. Maybe this should be handled by introducing an
// undefined expression or literal? Revisit this code if this
// changes
Expression* expression = expressions->at(i);
if (expression != NULL) Visit(expression);
}
}
// ----------------------------------------------------------------------------
// Regular expressions
#define MAKE_ACCEPT(Name) \
void* RegExp##Name::Accept(RegExpVisitor* visitor, void* data) { \
return visitor->Visit##Name(this, data); \
}
FOR_EACH_REG_EXP_TREE_TYPE(MAKE_ACCEPT)
#undef MAKE_ACCEPT
#define MAKE_TYPE_CASE(Name) \
RegExp##Name* RegExpTree::As##Name() { \
return NULL; \
} \
bool RegExpTree::Is##Name() { return false; }
FOR_EACH_REG_EXP_TREE_TYPE(MAKE_TYPE_CASE)
#undef MAKE_TYPE_CASE
#define MAKE_TYPE_CASE(Name) \
RegExp##Name* RegExp##Name::As##Name() { \
return this; \
} \
bool RegExp##Name::Is##Name() { return true; }
FOR_EACH_REG_EXP_TREE_TYPE(MAKE_TYPE_CASE)
#undef MAKE_TYPE_CASE
RegExpEmpty RegExpEmpty::kInstance;
static Interval ListCaptureRegisters(ZoneList<RegExpTree*>* children) {
Interval result = Interval::Empty();
for (int i = 0; i < children->length(); i++)
result = result.Union(children->at(i)->CaptureRegisters());
return result;
}
Interval RegExpAlternative::CaptureRegisters() {
return ListCaptureRegisters(nodes());
}
Interval RegExpDisjunction::CaptureRegisters() {
return ListCaptureRegisters(alternatives());
}
Interval RegExpLookahead::CaptureRegisters() {
return body()->CaptureRegisters();
}
Interval RegExpCapture::CaptureRegisters() {
Interval self(StartRegister(index()), EndRegister(index()));
return self.Union(body()->CaptureRegisters());
}
Interval RegExpQuantifier::CaptureRegisters() {
return body()->CaptureRegisters();
}
bool RegExpAssertion::IsAnchoredAtStart() {
return type() == RegExpAssertion::START_OF_INPUT;
}
bool RegExpAssertion::IsAnchoredAtEnd() {
return type() == RegExpAssertion::END_OF_INPUT;
}
bool RegExpAlternative::IsAnchoredAtStart() {
ZoneList<RegExpTree*>* nodes = this->nodes();
for (int i = 0; i < nodes->length(); i++) {
RegExpTree* node = nodes->at(i);
if (node->IsAnchoredAtStart()) { return true; }
if (node->max_match() > 0) { return false; }
}
return false;
}
bool RegExpAlternative::IsAnchoredAtEnd() {
ZoneList<RegExpTree*>* nodes = this->nodes();
for (int i = nodes->length() - 1; i >= 0; i--) {
RegExpTree* node = nodes->at(i);
if (node->IsAnchoredAtEnd()) { return true; }
if (node->max_match() > 0) { return false; }
}
return false;
}
bool RegExpDisjunction::IsAnchoredAtStart() {
ZoneList<RegExpTree*>* alternatives = this->alternatives();
for (int i = 0; i < alternatives->length(); i++) {
if (!alternatives->at(i)->IsAnchoredAtStart())
return false;
}
return true;
}
bool RegExpDisjunction::IsAnchoredAtEnd() {
ZoneList<RegExpTree*>* alternatives = this->alternatives();
for (int i = 0; i < alternatives->length(); i++) {
if (!alternatives->at(i)->IsAnchoredAtEnd())
return false;
}
return true;
}
bool RegExpLookahead::IsAnchoredAtStart() {
return is_positive() && body()->IsAnchoredAtStart();
}
bool RegExpCapture::IsAnchoredAtStart() {
return body()->IsAnchoredAtStart();
}
bool RegExpCapture::IsAnchoredAtEnd() {
return body()->IsAnchoredAtEnd();
}
// Convert regular expression trees to a simple sexp representation.
// This representation should be different from the input grammar
// in as many cases as possible, to make it more difficult for incorrect
// parses to look as correct ones which is likely if the input and
// output formats are alike.
class RegExpUnparser: public RegExpVisitor {
public:
RegExpUnparser();
void VisitCharacterRange(CharacterRange that);
SmartPointer<const char> ToString() { return stream_.ToCString(); }
#define MAKE_CASE(Name) virtual void* Visit##Name(RegExp##Name*, void* data);
FOR_EACH_REG_EXP_TREE_TYPE(MAKE_CASE)
#undef MAKE_CASE
private:
StringStream* stream() { return &stream_; }
HeapStringAllocator alloc_;
StringStream stream_;
};
RegExpUnparser::RegExpUnparser() : stream_(&alloc_) {
}
void* RegExpUnparser::VisitDisjunction(RegExpDisjunction* that, void* data) {
stream()->Add("(|");
for (int i = 0; i < that->alternatives()->length(); i++) {
stream()->Add(" ");
that->alternatives()->at(i)->Accept(this, data);
}
stream()->Add(")");
return NULL;
}
void* RegExpUnparser::VisitAlternative(RegExpAlternative* that, void* data) {
stream()->Add("(:");
for (int i = 0; i < that->nodes()->length(); i++) {
stream()->Add(" ");
that->nodes()->at(i)->Accept(this, data);
}
stream()->Add(")");
return NULL;
}
void RegExpUnparser::VisitCharacterRange(CharacterRange that) {
stream()->Add("%k", that.from());
if (!that.IsSingleton()) {
stream()->Add("-%k", that.to());
}
}
void* RegExpUnparser::VisitCharacterClass(RegExpCharacterClass* that,
void* data) {
if (that->is_negated())
stream()->Add("^");
stream()->Add("[");
for (int i = 0; i < that->ranges()->length(); i++) {
if (i > 0) stream()->Add(" ");
VisitCharacterRange(that->ranges()->at(i));
}
stream()->Add("]");
return NULL;
}
void* RegExpUnparser::VisitAssertion(RegExpAssertion* that, void* data) {
switch (that->type()) {
case RegExpAssertion::START_OF_INPUT:
stream()->Add("@^i");
break;
case RegExpAssertion::END_OF_INPUT:
stream()->Add("@$i");
break;
case RegExpAssertion::START_OF_LINE:
stream()->Add("@^l");
break;
case RegExpAssertion::END_OF_LINE:
stream()->Add("@$l");
break;
case RegExpAssertion::BOUNDARY:
stream()->Add("@b");
break;
case RegExpAssertion::NON_BOUNDARY:
stream()->Add("@B");
break;
}
return NULL;
}
void* RegExpUnparser::VisitAtom(RegExpAtom* that, void* data) {
stream()->Add("'");
Vector<const uc16> chardata = that->data();
for (int i = 0; i < chardata.length(); i++) {
stream()->Add("%k", chardata[i]);
}
stream()->Add("'");
return NULL;
}
void* RegExpUnparser::VisitText(RegExpText* that, void* data) {
if (that->elements()->length() == 1) {
that->elements()->at(0).data.u_atom->Accept(this, data);
} else {
stream()->Add("(!");
for (int i = 0; i < that->elements()->length(); i++) {
stream()->Add(" ");
that->elements()->at(i).data.u_atom->Accept(this, data);
}
stream()->Add(")");
}
return NULL;
}
void* RegExpUnparser::VisitQuantifier(RegExpQuantifier* that, void* data) {
stream()->Add("(# %i ", that->min());
if (that->max() == RegExpTree::kInfinity) {
stream()->Add("- ");
} else {
stream()->Add("%i ", that->max());
}
stream()->Add(that->is_greedy() ? "g " : that->is_possessive() ? "p " : "n ");
that->body()->Accept(this, data);
stream()->Add(")");
return NULL;
}
void* RegExpUnparser::VisitCapture(RegExpCapture* that, void* data) {
stream()->Add("(^ ");
that->body()->Accept(this, data);
stream()->Add(")");
return NULL;
}
void* RegExpUnparser::VisitLookahead(RegExpLookahead* that, void* data) {
stream()->Add("(-> ");
stream()->Add(that->is_positive() ? "+ " : "- ");
that->body()->Accept(this, data);
stream()->Add(")");
return NULL;
}
void* RegExpUnparser::VisitBackReference(RegExpBackReference* that,
void* data) {
stream()->Add("(<- %i)", that->index());
return NULL;
}
void* RegExpUnparser::VisitEmpty(RegExpEmpty* that, void* data) {
stream()->Put('%');
return NULL;
}
SmartPointer<const char> RegExpTree::ToString() {
RegExpUnparser unparser;
Accept(&unparser, NULL);
return unparser.ToString();
}
RegExpDisjunction::RegExpDisjunction(ZoneList<RegExpTree*>* alternatives)
: alternatives_(alternatives) {
ASSERT(alternatives->length() > 1);
RegExpTree* first_alternative = alternatives->at(0);
min_match_ = first_alternative->min_match();
max_match_ = first_alternative->max_match();
for (int i = 1; i < alternatives->length(); i++) {
RegExpTree* alternative = alternatives->at(i);
min_match_ = Min(min_match_, alternative->min_match());
max_match_ = Max(max_match_, alternative->max_match());
}
}
RegExpAlternative::RegExpAlternative(ZoneList<RegExpTree*>* nodes)
: nodes_(nodes) {
ASSERT(nodes->length() > 1);
min_match_ = 0;
max_match_ = 0;
for (int i = 0; i < nodes->length(); i++) {
RegExpTree* node = nodes->at(i);
min_match_ += node->min_match();
int node_max_match = node->max_match();
if (kInfinity - max_match_ < node_max_match) {
max_match_ = kInfinity;
} else {
max_match_ += node->max_match();
}
}
}
CaseClause::CaseClause(Expression* label,
ZoneList<Statement*>* statements,
int pos)
: label_(label),
statements_(statements),
position_(pos),
compare_type_(NONE) {}
} } // namespace v8::internal
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