root/src/ast.cc

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DEFINITIONS

This source file includes following definitions.
  1. AST_NODE_LIST
  2. IsStringLiteral
  3. IsNullLiteral
  4. interface_
  5. interface_
  6. BindTo
  7. is_monomorphic_
  8. binary_op
  9. AllowsLazyCompilation
  10. AllowsLazyCompilationWithoutContext
  11. start_position
  12. end_position
  13. language_mode
  14. IsCompileTimeValue
  15. set_emit_store
  16. emit_store
  17. IsEqualString
  18. IsEqualNumber
  19. CalculateEmitStore
  20. AddTarget
  21. ResultOverwriteAllowed
  22. ResultOverwriteAllowed
  23. IsTypeof
  24. MatchLiteralCompareTypeof
  25. IsLiteralCompareTypeof
  26. IsVoidOfLiteral
  27. MatchLiteralCompareUndefined
  28. IsLiteralCompareUndefined
  29. MatchLiteralCompareNull
  30. IsLiteralCompareNull
  31. IsInlineable
  32. IsInlineable
  33. RecordTypeFeedback
  34. RecordTypeFeedback
  35. RecordTypeFeedback
  36. RecordTypeFeedback
  37. ComputeTarget
  38. ComputeGlobalTarget
  39. RecordTypeFeedback
  40. RecordTypeFeedback
  41. RecordTypeFeedback
  42. RecordTypeFeedback
  43. CheckStackOverflow
  44. VisitDeclarations
  45. VisitStatements
  46. VisitExpressions
  47. FOR_EACH_REG_EXP_TREE_TYPE
  48. Name
  49. FOR_EACH_REG_EXP_TREE_TYPE
  50. FOR_EACH_REG_EXP_TREE_TYPE
  51. CaptureRegisters
  52. CaptureRegisters
  53. CaptureRegisters
  54. CaptureRegisters
  55. CaptureRegisters
  56. IsAnchoredAtStart
  57. IsAnchoredAtEnd
  58. IsAnchoredAtStart
  59. IsAnchoredAtEnd
  60. IsAnchoredAtStart
  61. IsAnchoredAtEnd
  62. IsAnchoredAtStart
  63. IsAnchoredAtStart
  64. IsAnchoredAtEnd
  65. ToString
  66. FOR_EACH_REG_EXP_TREE_TYPE
  67. zone_
  68. VisitDisjunction
  69. VisitAlternative
  70. VisitCharacterRange
  71. VisitCharacterClass
  72. VisitAssertion
  73. VisitAtom
  74. VisitText
  75. VisitQuantifier
  76. VisitCapture
  77. VisitLookahead
  78. VisitBackReference
  79. VisitEmpty
  80. ToString
  81. IncreaseBy
  82. entry_id_
  83. REGULAR_NODE
  84. ToString

// Copyright 2012 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 "ast.h"

#include <math.h>  // For isfinite.
#include "builtins.h"
#include "conversions.h"
#include "hashmap.h"
#include "parser.h"
#include "property-details.h"
#include "property.h"
#include "scopes.h"
#include "string-stream.h"
#include "type-info.h"

namespace v8 {
namespace internal {

// ----------------------------------------------------------------------------
// All the Accept member functions for each syntax tree node type.

#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.


bool Expression::IsSmiLiteral() {
  return AsLiteral() != NULL && AsLiteral()->handle()->IsSmi();
}


bool Expression::IsStringLiteral() {
  return AsLiteral() != NULL && AsLiteral()->handle()->IsString();
}


bool Expression::IsNullLiteral() {
  return AsLiteral() != NULL && AsLiteral()->handle()->IsNull();
}


VariableProxy::VariableProxy(Isolate* isolate, Variable* var)
    : Expression(isolate),
      name_(var->name()),
      var_(NULL),  // Will be set by the call to BindTo.
      is_this_(var->is_this()),
      is_trivial_(false),
      is_lvalue_(false),
      position_(RelocInfo::kNoPosition),
      interface_(var->interface()) {
  BindTo(var);
}


VariableProxy::VariableProxy(Isolate* isolate,
                             Handle<String> name,
                             bool is_this,
                             Interface* interface,
                             int position)
    : Expression(isolate),
      name_(name),
      var_(NULL),
      is_this_(is_this),
      is_trivial_(false),
      is_lvalue_(false),
      position_(position),
      interface_(interface) {
  // Names must be canonicalized for fast equality checks.
  ASSERT(name->IsSymbol());
}


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(Isolate* isolate,
                       Token::Value op,
                       Expression* target,
                       Expression* value,
                       int pos)
    : Expression(isolate),
      op_(op),
      target_(target),
      value_(value),
      pos_(pos),
      binary_operation_(NULL),
      compound_load_id_(kNoNumber),
      assignment_id_(GetNextId(isolate)),
      block_start_(false),
      block_end_(false),
      is_monomorphic_(false) { }


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::AllowsLazyCompilationWithoutContext() {
  return scope()->AllowsLazyCompilationWithoutContext();
}


int FunctionLiteral::start_position() const {
  return scope()->start_position();
}


int FunctionLiteral::end_position() const {
  return scope()->end_position();
}


LanguageMode FunctionLiteral::language_mode() const {
  return scope()->language_mode();
}


ObjectLiteral::Property::Property(Literal* key,
                                  Expression* value,
                                  Isolate* isolate) {
  emit_store_ = true;
  key_ = key;
  value_ = value;
  Object* k = *key->handle();
  if (k->IsSymbol() &&
      isolate->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;
  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) {
  ASSERT((*reinterpret_cast<String**>(first))->IsString());
  ASSERT((*reinterpret_cast<String**>(second))->IsString());
  Handle<String> h1(reinterpret_cast<String**>(first));
  Handle<String> h2(reinterpret_cast<String**>(second));
  return (*h1)->Equals(*h2);
}


bool IsEqualNumber(void* first, void* second) {
  ASSERT((*reinterpret_cast<Object**>(first))->IsNumber());
  ASSERT((*reinterpret_cast<Object**>(second))->IsNumber());

  Handle<Object> h1(reinterpret_cast<Object**>(first));
  Handle<Object> h2(reinterpret_cast<Object**>(second));
  if (h1->IsSmi()) {
    return h2->IsSmi() && *h1 == *h2;
  }
  if (h2->IsSmi()) return false;
  Handle<HeapNumber> n1 = Handle<HeapNumber>::cast(h1);
  Handle<HeapNumber> n2 = Handle<HeapNumber>::cast(h2);
  ASSERT(isfinite(n1->value()));
  ASSERT(isfinite(n2->value()));
  return n1->value() == n2->value();
}


void ObjectLiteral::CalculateEmitStore(Zone* zone) {
  ZoneAllocationPolicy allocator(zone);

  ZoneHashMap table(Literal::Match, ZoneHashMap::kDefaultHashMapCapacity,
                    allocator);
  for (int i = properties()->length() - 1; i >= 0; i--) {
    ObjectLiteral::Property* property = properties()->at(i);
    Literal* literal = property->key();
    if (literal->handle()->IsNull()) continue;
    uint32_t hash = literal->Hash();
    // 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 &&
        table.Lookup(literal, hash, false, allocator) != NULL) {
      property->set_emit_store(false);
    } else {
      // Add key to the table.
      table.Lookup(literal, hash, true, allocator);
    }
  }
}


void TargetCollector::AddTarget(Label* target, Zone* zone) {
  // Add the label to the collector, but discard duplicates.
  int length = targets_.length();
  for (int i = 0; i < length; i++) {
    if (targets_[i] == target) return;
  }
  targets_.Add(target, zone);
}


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;
}


static bool IsTypeof(Expression* expr) {
  UnaryOperation* maybe_unary = expr->AsUnaryOperation();
  return maybe_unary != NULL && maybe_unary->op() == Token::TYPEOF;
}


// Check for the pattern: typeof <expression> equals <string literal>.
static bool MatchLiteralCompareTypeof(Expression* left,
                                      Token::Value op,
                                      Expression* right,
                                      Expression** expr,
                                      Handle<String>* check) {
  if (IsTypeof(left) && right->IsStringLiteral() && Token::IsEqualityOp(op)) {
    *expr = left->AsUnaryOperation()->expression();
    *check = Handle<String>::cast(right->AsLiteral()->handle());
    return true;
  }
  return false;
}


bool CompareOperation::IsLiteralCompareTypeof(Expression** expr,
                                              Handle<String>* check) {
  return MatchLiteralCompareTypeof(left_, op_, right_, expr, check) ||
      MatchLiteralCompareTypeof(right_, op_, left_, expr, check);
}


static bool IsVoidOfLiteral(Expression* expr) {
  UnaryOperation* maybe_unary = expr->AsUnaryOperation();
  return maybe_unary != NULL &&
      maybe_unary->op() == Token::VOID &&
      maybe_unary->expression()->AsLiteral() != NULL;
}


// Check for the pattern: void <literal> equals <expression>
static bool MatchLiteralCompareUndefined(Expression* left,
                                         Token::Value op,
                                         Expression* right,
                                         Expression** expr) {
  if (IsVoidOfLiteral(left) && Token::IsEqualityOp(op)) {
    *expr = right;
    return true;
  }
  return false;
}


bool CompareOperation::IsLiteralCompareUndefined(Expression** expr) {
  return MatchLiteralCompareUndefined(left_, op_, right_, expr) ||
      MatchLiteralCompareUndefined(right_, op_, left_, expr);
}


// Check for the pattern: null equals <expression>
static bool MatchLiteralCompareNull(Expression* left,
                                    Token::Value op,
                                    Expression* right,
                                    Expression** expr) {
  if (left->IsNullLiteral() && Token::IsEqualityOp(op)) {
    *expr = right;
    return true;
  }
  return false;
}


bool CompareOperation::IsLiteralCompareNull(Expression** expr) {
  return MatchLiteralCompareNull(left_, op_, right_, expr) ||
      MatchLiteralCompareNull(right_, op_, left_, expr);
}


// ----------------------------------------------------------------------------
// Inlining support

bool Declaration::IsInlineable() const {
  return proxy()->var()->IsStackAllocated();
}

bool FunctionDeclaration::IsInlineable() const {
  return false;
}


// ----------------------------------------------------------------------------
// Recording of type feedback

void Property::RecordTypeFeedback(TypeFeedbackOracle* oracle,
                                  Zone* zone) {
  // Record type feedback from the oracle in the AST.
  is_uninitialized_ = oracle->LoadIsUninitialized(this);
  if (is_uninitialized_) return;

  is_monomorphic_ = oracle->LoadIsMonomorphicNormal(this);
  receiver_types_.Clear();
  if (key()->IsPropertyName()) {
    if (oracle->LoadIsBuiltin(this, Builtins::kLoadIC_ArrayLength)) {
      is_array_length_ = true;
    } else if (oracle->LoadIsBuiltin(this, Builtins::kLoadIC_StringLength)) {
      is_string_length_ = true;
    } else if (oracle->LoadIsBuiltin(this,
                                     Builtins::kLoadIC_FunctionPrototype)) {
      is_function_prototype_ = true;
    } else {
      Literal* lit_key = key()->AsLiteral();
      ASSERT(lit_key != NULL && lit_key->handle()->IsString());
      Handle<String> name = Handle<String>::cast(lit_key->handle());
      oracle->LoadReceiverTypes(this, name, &receiver_types_);
    }
  } else if (oracle->LoadIsBuiltin(this, Builtins::kKeyedLoadIC_String)) {
    is_string_access_ = true;
  } else if (is_monomorphic_) {
    receiver_types_.Add(oracle->LoadMonomorphicReceiverType(this),
                        zone);
  } else if (oracle->LoadIsMegamorphicWithTypeInfo(this)) {
    receiver_types_.Reserve(kMaxKeyedPolymorphism, zone);
    oracle->CollectKeyedReceiverTypes(this->id(), &receiver_types_);
  }
}


void Assignment::RecordTypeFeedback(TypeFeedbackOracle* oracle,
                                    Zone* zone) {
  Property* prop = target()->AsProperty();
  ASSERT(prop != NULL);
  is_monomorphic_ = oracle->StoreIsMonomorphicNormal(this);
  receiver_types_.Clear();
  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());
    oracle->StoreReceiverTypes(this, name, &receiver_types_);
  } else if (is_monomorphic_) {
    // Record receiver type for monomorphic keyed stores.
    receiver_types_.Add(oracle->StoreMonomorphicReceiverType(this), zone);
  } else if (oracle->StoreIsMegamorphicWithTypeInfo(this)) {
    receiver_types_.Reserve(kMaxKeyedPolymorphism, zone);
    oracle->CollectKeyedReceiverTypes(this->id(), &receiver_types_);
  }
}


void CountOperation::RecordTypeFeedback(TypeFeedbackOracle* oracle,
                                        Zone* zone) {
  is_monomorphic_ = oracle->StoreIsMonomorphicNormal(this);
  receiver_types_.Clear();
  if (is_monomorphic_) {
    // Record receiver type for monomorphic keyed stores.
    receiver_types_.Add(oracle->StoreMonomorphicReceiverType(this), zone);
  } else if (oracle->StoreIsMegamorphicWithTypeInfo(this)) {
    receiver_types_.Reserve(kMaxKeyedPolymorphism, zone);
    oracle->CollectKeyedReceiverTypes(this->id(), &receiver_types_);
  }
}


void CaseClause::RecordTypeFeedback(TypeFeedbackOracle* oracle) {
  TypeInfo info = oracle->SwitchType(this);
  if (info.IsSmi()) {
    compare_type_ = SMI_ONLY;
  } else if (info.IsSymbol()) {
    compare_type_ = SYMBOL_ONLY;
  } else if (info.IsNonSymbol()) {
    compare_type_ = STRING_ONLY;
  } else if (info.IsNonPrimitive()) {
    compare_type_ = OBJECT_ONLY;
  } else {
    ASSERT(compare_type_ == NONE);
  }
}


bool Call::ComputeTarget(Handle<Map> type, Handle<String> name) {
  // If there is an interceptor, we can't compute the target for a direct call.
  if (type->has_named_interceptor()) return false;

  if (check_type_ == RECEIVER_MAP_CHECK) {
    // For primitive checks the holder is set up to point to the corresponding
    // prototype object, i.e. one step of the algorithm below has been already
    // performed. For non-primitive checks we clear it to allow computing
    // targets for polymorphic calls.
    holder_ = Handle<JSObject>::null();
  }
  LookupResult lookup(type->GetIsolate());
  while (true) {
    type->LookupDescriptor(NULL, *name, &lookup);
    if (lookup.IsFound()) {
      switch (lookup.type()) {
        case CONSTANT_FUNCTION:
          // We surely know the target for a constant function.
          target_ =
              Handle<JSFunction>(lookup.GetConstantFunctionFromMap(*type));
          return true;
        case NORMAL:
        case FIELD:
        case CALLBACKS:
        case HANDLER:
        case INTERCEPTOR:
          // We don't know the target.
          return false;
        case TRANSITION:
        case NONEXISTENT:
          UNREACHABLE();
          break;
      }
    }
    // If we reach the end of the prototype chain, we don't know the target.
    if (!type->prototype()->IsJSObject()) return false;
    // Go up the prototype chain, recording where we are currently.
    holder_ = Handle<JSObject>(JSObject::cast(type->prototype()));
    if (!holder_->HasFastProperties()) return false;
    type = Handle<Map>(holder()->map());
  }
}


bool Call::ComputeGlobalTarget(Handle<GlobalObject> global,
                               LookupResult* lookup) {
  target_ = Handle<JSFunction>::null();
  cell_ = Handle<JSGlobalPropertyCell>::null();
  ASSERT(lookup->IsFound() &&
         lookup->type() == NORMAL &&
         lookup->holder() == *global);
  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)) {
      target_ = candidate;
      return true;
    }
  }
  return false;
}


void Call::RecordTypeFeedback(TypeFeedbackOracle* oracle,
                              CallKind call_kind) {
  is_monomorphic_ = oracle->CallIsMonomorphic(this);
  Property* property = expression()->AsProperty();
  if (property == NULL) {
    // Function call.  Specialize for monomorphic calls.
    if (is_monomorphic_) target_ = oracle->GetCallTarget(this);
  } else {
    // Method call.  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_.Clear();
    oracle->CallReceiverTypes(this, name, call_kind, &receiver_types_);
#ifdef DEBUG
    if (FLAG_enable_slow_asserts) {
      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
    check_type_ = oracle->GetCallCheckType(this);
    if (is_monomorphic_) {
      Handle<Map> map;
      if (receiver_types_.length() > 0) {
        ASSERT(check_type_ == RECEIVER_MAP_CHECK);
        map = receiver_types_.at(0);
      } else {
        ASSERT(check_type_ != RECEIVER_MAP_CHECK);
        holder_ = Handle<JSObject>(
            oracle->GetPrototypeForPrimitiveCheck(check_type_));
        map = Handle<Map>(holder_->map());
      }
      is_monomorphic_ = ComputeTarget(map, name);
    }
  }
}


void CallNew::RecordTypeFeedback(TypeFeedbackOracle* oracle) {
  is_monomorphic_ = oracle->CallNewIsMonomorphic(this);
  if (is_monomorphic_) {
    target_ = oracle->GetCallNewTarget(this);
  }
}


void CompareOperation::RecordTypeFeedback(TypeFeedbackOracle* oracle) {
  TypeInfo info = oracle->CompareType(this);
  if (info.IsSmi()) {
    compare_type_ = SMI_ONLY;
  } else if (info.IsNonPrimitive()) {
    compare_type_ = OBJECT_ONLY;
  } else {
    ASSERT(compare_type_ == NONE);
  }
}


void ObjectLiteral::Property::RecordTypeFeedback(TypeFeedbackOracle* oracle) {
  receiver_type_ = oracle->ObjectLiteralStoreIsMonomorphic(this)
      ? oracle->GetObjectLiteralStoreMap(this)
      : Handle<Map>::null();
}


// ----------------------------------------------------------------------------
// Implementation of AstVisitor

bool AstVisitor::CheckStackOverflow() {
  if (stack_overflow_) return true;
  StackLimitCheck check(isolate_);
  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


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:
  explicit RegExpUnparser(Zone* zone);
  void VisitCharacterRange(CharacterRange that);
  SmartArrayPointer<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_;
  Zone* zone_;
};


RegExpUnparser::RegExpUnparser(Zone* zone) : stream_(&alloc_), zone_(zone) {
}


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(zone_)->length(); i++) {
    if (i > 0) stream()->Add(" ");
    VisitCharacterRange(that->ranges(zone_)->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;
}


SmartArrayPointer<const char> RegExpTree::ToString(Zone* zone) {
  RegExpUnparser unparser(zone);
  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());
  }
}


static int IncreaseBy(int previous, int increase) {
  if (RegExpTree::kInfinity - previous < increase) {
    return RegExpTree::kInfinity;
  } else {
    return previous + increase;
  }
}

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);
    int node_min_match = node->min_match();
    min_match_ = IncreaseBy(min_match_, node_min_match);
    int node_max_match = node->max_match();
    max_match_ = IncreaseBy(max_match_, node_max_match);
  }
}


CaseClause::CaseClause(Isolate* isolate,
                       Expression* label,
                       ZoneList<Statement*>* statements,
                       int pos)
    : label_(label),
      statements_(statements),
      position_(pos),
      compare_type_(NONE),
      compare_id_(AstNode::GetNextId(isolate)),
      entry_id_(AstNode::GetNextId(isolate)) {
}


#define REGULAR_NODE(NodeType) \
  void AstConstructionVisitor::Visit##NodeType(NodeType* node) { \
    increase_node_count(); \
  }
#define DONT_OPTIMIZE_NODE(NodeType) \
  void AstConstructionVisitor::Visit##NodeType(NodeType* node) { \
    increase_node_count(); \
    add_flag(kDontOptimize); \
    add_flag(kDontInline); \
    add_flag(kDontSelfOptimize); \
  }
#define DONT_INLINE_NODE(NodeType) \
  void AstConstructionVisitor::Visit##NodeType(NodeType* node) { \
    increase_node_count(); \
    add_flag(kDontInline); \
  }
#define DONT_SELFOPTIMIZE_NODE(NodeType) \
  void AstConstructionVisitor::Visit##NodeType(NodeType* node) { \
    increase_node_count(); \
    add_flag(kDontSelfOptimize); \
  }
#define DONT_CACHE_NODE(NodeType) \
  void AstConstructionVisitor::Visit##NodeType(NodeType* node) { \
    increase_node_count(); \
    add_flag(kDontOptimize); \
    add_flag(kDontInline); \
    add_flag(kDontSelfOptimize); \
    add_flag(kDontCache); \
  }

REGULAR_NODE(VariableDeclaration)
REGULAR_NODE(FunctionDeclaration)
REGULAR_NODE(Block)
REGULAR_NODE(ExpressionStatement)
REGULAR_NODE(EmptyStatement)
REGULAR_NODE(IfStatement)
REGULAR_NODE(ContinueStatement)
REGULAR_NODE(BreakStatement)
REGULAR_NODE(ReturnStatement)
REGULAR_NODE(SwitchStatement)
REGULAR_NODE(Conditional)
REGULAR_NODE(Literal)
REGULAR_NODE(ObjectLiteral)
REGULAR_NODE(RegExpLiteral)
REGULAR_NODE(Assignment)
REGULAR_NODE(Throw)
REGULAR_NODE(Property)
REGULAR_NODE(UnaryOperation)
REGULAR_NODE(CountOperation)
REGULAR_NODE(BinaryOperation)
REGULAR_NODE(CompareOperation)
REGULAR_NODE(ThisFunction)
REGULAR_NODE(Call)
REGULAR_NODE(CallNew)
// In theory, for VariableProxy we'd have to add:
// if (node->var()->IsLookupSlot()) add_flag(kDontInline);
// But node->var() is usually not bound yet at VariableProxy creation time, and
// LOOKUP variables only result from constructs that cannot be inlined anyway.
REGULAR_NODE(VariableProxy)

// We currently do not optimize any modules. Note in particular, that module
// instance objects associated with ModuleLiterals are allocated during
// scope resolution, and references to them are embedded into the code.
// That code may hence neither be cached nor re-compiled.
DONT_OPTIMIZE_NODE(ModuleDeclaration)
DONT_OPTIMIZE_NODE(ImportDeclaration)
DONT_OPTIMIZE_NODE(ExportDeclaration)
DONT_OPTIMIZE_NODE(ModuleVariable)
DONT_OPTIMIZE_NODE(ModulePath)
DONT_OPTIMIZE_NODE(ModuleUrl)
DONT_OPTIMIZE_NODE(WithStatement)
DONT_OPTIMIZE_NODE(TryCatchStatement)
DONT_OPTIMIZE_NODE(TryFinallyStatement)
DONT_OPTIMIZE_NODE(DebuggerStatement)
DONT_OPTIMIZE_NODE(SharedFunctionInfoLiteral)

DONT_INLINE_NODE(ArrayLiteral)  // TODO(1322): Allow materialized literals.
DONT_INLINE_NODE(FunctionLiteral)

DONT_SELFOPTIMIZE_NODE(DoWhileStatement)
DONT_SELFOPTIMIZE_NODE(WhileStatement)
DONT_SELFOPTIMIZE_NODE(ForStatement)
DONT_SELFOPTIMIZE_NODE(ForInStatement)

DONT_CACHE_NODE(ModuleLiteral)

void AstConstructionVisitor::VisitCallRuntime(CallRuntime* node) {
  increase_node_count();
  if (node->is_jsruntime()) {
    // Don't try to inline JS runtime calls because we don't (currently) even
    // optimize them.
    add_flag(kDontInline);
  } else if (node->function()->intrinsic_type == Runtime::INLINE &&
      (node->name()->IsEqualTo(CStrVector("_ArgumentsLength")) ||
       node->name()->IsEqualTo(CStrVector("_Arguments")))) {
    // Don't inline the %_ArgumentsLength or %_Arguments because their
    // implementation will not work.  There is no stack frame to get them
    // from.
    add_flag(kDontInline);
  }
}

#undef REGULAR_NODE
#undef DONT_OPTIMIZE_NODE
#undef DONT_INLINE_NODE
#undef DONT_SELFOPTIMIZE_NODE
#undef DONT_CACHE_NODE


Handle<String> Literal::ToString() {
  if (handle_->IsString()) return Handle<String>::cast(handle_);
  ASSERT(handle_->IsNumber());
  char arr[100];
  Vector<char> buffer(arr, ARRAY_SIZE(arr));
  const char* str;
  if (handle_->IsSmi()) {
    // Optimization only, the heap number case would subsume this.
    OS::SNPrintF(buffer, "%d", Smi::cast(*handle_)->value());
    str = arr;
  } else {
    str = DoubleToCString(handle_->Number(), buffer);
  }
  return FACTORY->NewStringFromAscii(CStrVector(str));
}


} }  // namespace v8::internal

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