src/variables.cc

// Copyright 2011 the V8 project authors. All rights reserved.
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#include "v8.h"

#include "ast.h"
#include "scopes.h"
#include "variables.h"

namespace v8 {
namespace internal {

// ----------------------------------------------------------------------------
// Implementation Variable.

const char* Variable::Mode2String(Mode mode) {
  switch (mode) {
    case VAR: return "VAR";
    case CONST: return "CONST";
    case DYNAMIC: return "DYNAMIC";
    case DYNAMIC_GLOBAL: return "DYNAMIC_GLOBAL";
    case DYNAMIC_LOCAL: return "DYNAMIC_LOCAL";
    case INTERNAL: return "INTERNAL";
    case TEMPORARY: return "TEMPORARY";
  }
  UNREACHABLE();
  return NULL;
}


Property* Variable::AsProperty() const {
  return rewrite_ == NULL ? NULL : rewrite_->AsProperty();
}


Slot* Variable::AsSlot() const {
  return rewrite_ == NULL ? NULL : rewrite_->AsSlot();
}


bool Variable::IsStackAllocated() const {
  Slot* slot = AsSlot();
  return slot != NULL && slot->IsStackAllocated();
}


bool Variable::IsParameter() const {
  Slot* s = AsSlot();
  return s != NULL && s->type() == Slot::PARAMETER;
}


bool Variable::IsStackLocal() const {
  Slot* s = AsSlot();
  return s != NULL && s->type() == Slot::LOCAL;
}


bool Variable::IsContextSlot() const {
  Slot* s = AsSlot();
  return s != NULL && s->type() == Slot::CONTEXT;
}


Variable::Variable(Scope* scope,
                   Handle<String> name,
                   Mode mode,
                   bool is_valid_LHS,
                   Kind kind)
  : scope_(scope),
    name_(name),
    mode_(mode),
    kind_(kind),
    local_if_not_shadowed_(NULL),
    rewrite_(NULL),
    is_valid_LHS_(is_valid_LHS),
    is_accessed_from_inner_scope_(false),
    is_used_(false) {
  // names must be canonicalized for fast equality checks
  ASSERT(name->IsSymbol());
}


bool Variable::is_global() const {
  // Temporaries are never global, they must always be allocated in the
  // activation frame.
  return mode_ != TEMPORARY && scope_ != NULL && scope_->is_global_scope();
}

} }  // namespace v8::internal