runtime.cc.svn-base

Google浏览器V8内核代码

  return f->shared()->GetSourceCode();
}


static Object* Runtime_FunctionGetScriptSourcePosition(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 1);

  CONVERT_CHECKED(JSFunction, fun, args[0]);
  int pos = fun->shared()->start_position();
  return Smi::FromInt(pos);
}


static Object* Runtime_FunctionSetInstanceClassName(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_CHECKED(JSFunction, fun, args[0]);
  CONVERT_CHECKED(String, name, args[1]);
  fun->SetInstanceClassName(name);
  return Heap::undefined_value();
}


static Object* Runtime_FunctionSetLength(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_CHECKED(JSFunction, fun, args[0]);
  CONVERT_CHECKED(Smi, length, args[1]);
  fun->shared()->set_length(length->value());
  return length;
}


static Object* Runtime_FunctionSetPrototype(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_CHECKED(JSFunction, fun, args[0]);
  Object* obj = Accessors::FunctionSetPrototype(fun, args[1], NULL);
  if (obj->IsFailure()) return obj;
  return args[0];  // return TOS
}


static Object* Runtime_SetCode(Arguments args) {
  HandleScope scope;
  ASSERT(args.length() == 2);

  CONVERT_CHECKED(JSFunction, raw_target, args[0]);
  Handle<JSFunction> target(raw_target);
  Handle<Object> code = args.at<Object>(1);

  Handle<Context> context(target->context());

  if (!code->IsNull()) {
    RUNTIME_ASSERT(code->IsJSFunction());
    Handle<JSFunction> fun = Handle<JSFunction>::cast(code);
    SetExpectedNofProperties(target, fun->shared()->expected_nof_properties());
    if (!fun->is_compiled() && !CompileLazy(fun, KEEP_EXCEPTION)) {
      return Failure::Exception();
    }
    // Set the code, formal parameter count, and the length of the target
    // function.
    target->set_code(fun->code());
    target->shared()->set_length(fun->shared()->length());
    target->shared()->set_formal_parameter_count(
                          fun->shared()->formal_parameter_count());
    // Set the source code of the target function.
    target->shared()->set_script(fun->shared()->script());
    target->shared()->set_start_position(fun->shared()->start_position());
    target->shared()->set_end_position(fun->shared()->end_position());
    context = Handle<Context>(fun->context());

    // Make sure we get a fresh copy of the literal vector to avoid
    // cross context contamination.
    int number_of_literals = fun->NumberOfLiterals();
    Handle<FixedArray> literals =
        Factory::NewFixedArray(number_of_literals, TENURED);
    if (number_of_literals > 0) {
      // Insert the object, regexp and array functions in the literals
      // array prefix.  These are the functions that will be used when
      // creating object, regexp and array literals.
      literals->set(JSFunction::kLiteralGlobalContextIndex,
                    context->global_context());
    }
    target->set_literals(*literals);
  }

  target->set_context(*context);
  return *target;
}


static Object* CharCodeAt(String* subject, Object* index) {
  uint32_t i = 0;
  if (!Array::IndexFromObject(index, &i)) return Heap::nan_value();
  // Flatten the string.  If someone wants to get a char at an index
  // in a cons string, it is likely that more indices will be
  // accessed.
  subject->TryFlatten();
  if (i >= static_cast<uint32_t>(subject->length())) return Heap::nan_value();
  return Smi::FromInt(subject->Get(i));
}


static Object* Runtime_StringCharCodeAt(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_CHECKED(String, subject, args[0]);
  Object* index = args[1];
  return CharCodeAt(subject, index);
}


static Object* Runtime_CharFromCode(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 1);
  uint32_t code;
  if (Array::IndexFromObject(args[0], &code)) {
    if (code <= 0xffff) {
      return Heap::LookupSingleCharacterStringFromCode(code);
    }
  }
  return Heap::empty_string();
}


static inline void ComputeKMPNextTable(String* pattern, int next_table[]) {
  int i = 0;
  int j = -1;
  next_table[0] = -1;

  Access<StringInputBuffer> buffer(&string_input_buffer);
  buffer->Reset(pattern);
  int length = pattern->length();
  uint16_t p = buffer->GetNext();
  while (i < length - 1) {
    while (j > -1 && p != pattern->Get(j)) {
      j = next_table[j];
    }
    i++;
    j++;
    p = buffer->GetNext();
    if (p == pattern->Get(j)) {
      next_table[i] = next_table[j];
    } else {
      next_table[i] = j;
    }
  }
}


static Object* Runtime_StringIndexOf(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 3);

  CONVERT_CHECKED(String, sub, args[0]);
  CONVERT_CHECKED(String, pat, args[1]);
  Object* index = args[2];

  sub->TryFlatten();
  pat->TryFlatten();

  int subject_length = sub->length();
  int pattern_length = pat->length();

  uint32_t start_index;
  if (!Array::IndexFromObject(index, &start_index)) return Smi::FromInt(-1);
  if (pattern_length == 0) return Smi::FromInt(start_index);

  // Searching for one specific character is common.  For one
  // character patterns the KMP algorithm is guaranteed to slow down
  // the search, so we just run through the subject string.
  if (pattern_length == 1) {
    uint16_t pattern_char = pat->Get(0);
    for (int i = start_index; i < subject_length; i++) {
      if (sub->Get(i) == pattern_char) {
        return Smi::FromInt(i);
      }
    }
    return Smi::FromInt(-1);
  }

  // For small searches, KMP is not worth the setup overhead.
  if (subject_length < 100) {
    // We know our pattern is at least 2 characters, we cache the first so
    // the common case of the first character not matching is faster.
    uint16_t pattern_first_char = pat->Get(0);
    for (int i = start_index; i + pattern_length <= subject_length; i++) {
      if (sub->Get(i) != pattern_first_char) continue;

      for (int j = 1; j < pattern_length; j++) {
        if (pat->Get(j) != sub->Get(j + i)) break;
        if (j == pattern_length - 1) return Smi::FromInt(i);
      }
    }
    return Smi::FromInt(-1);
  }

  // For patterns with a larger length we use the KMP algorithm.
  //
  // Compute the 'next' table.
  int* next_table = NewArray<int>(pattern_length);
  ComputeKMPNextTable(pat, next_table);
  // Search using the 'next' table.
  int pattern_index = 0;
  // We would like to use StringInputBuffer here, but it does not have
  // the ability to start anywhere but the first character of a
  // string.  It would be nice to have efficient forward-seeking
  // support on StringInputBuffers.
  int subject_index = start_index;
  while (subject_index < subject_length) {
    uint16_t subject_char = sub->Get(subject_index);
    while (pattern_index > -1 && pat->Get(pattern_index) != subject_char) {
      pattern_index = next_table[pattern_index];
    }
    pattern_index++;
    subject_index++;
    if (pattern_index >= pattern_length) {
      DeleteArray(next_table);
      return Smi::FromInt(subject_index - pattern_index);
    }
  }
  DeleteArray(next_table);
  return Smi::FromInt(-1);
}


static Object* Runtime_StringLastIndexOf(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 3);

  CONVERT_CHECKED(String, sub, args[0]);
  CONVERT_CHECKED(String, pat, args[1]);
  Object* index = args[2];

  sub->TryFlatten();
  pat->TryFlatten();

  uint32_t start_index;
  if (!Array::IndexFromObject(index, &start_index)) return Smi::FromInt(-1);

  uint32_t pattern_length = pat->length();
  uint32_t sub_length = sub->length();

  if (start_index + pattern_length > sub_length) {
    start_index = sub_length - pattern_length;
  }

  for (int i = start_index; i >= 0; i--) {
    bool found = true;
    for (uint32_t j = 0; j < pattern_length; j++) {
      if (sub->Get(i + j) != pat->Get(j)) {
        found = false;
        break;
      }
    }
    if (found) return Smi::FromInt(i);
  }

  return Smi::FromInt(-1);
}


static Object* Runtime_StringLocaleCompare(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_CHECKED(String, str1, args[0]);
  CONVERT_CHECKED(String, str2, args[1]);

  if (str1 == str2) return Smi::FromInt(0);  // Equal.
  int str1_length = str1->length();
  int str2_length = str2->length();

  // Decide trivial cases without flattening.
  if (str1_length == 0) {
    if (str2_length == 0) return Smi::FromInt(0);  // Equal.
    return Smi::FromInt(-str2_length);
  } else {
    if (str2_length == 0) return Smi::FromInt(str1_length);
  }

  int end = str1_length < str2_length ? str1_length : str2_length;

  // No need to flatten if we are going to find the answer on the first
  // character.  At this point we know there is at least one character
  // in each string, due to the trivial case handling above.
  int d = str1->Get(0) - str2->Get(0);
  if (d != 0) return Smi::FromInt(d);

  str1->TryFlatten();
  str2->TryFlatten();

  static StringInputBuffer buf1;
  static StringInputBuffer buf2;

  buf1.Reset(str1);
  buf2.Reset(str2);

  for (int i = 0; i < end; i++) {
    uint16_t char1 = buf1.GetNext();
    uint16_t char2 = buf2.GetNext();
    if (char1 != char2) return Smi::FromInt(char1 - char2);
  }

  return Smi::FromInt(str1_length - str2_length);
}


static Object* Runtime_StringSlice(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 3);

  CONVERT_CHECKED(String, value, args[0]);
  CONVERT_DOUBLE_CHECKED(from_number, args[1]);
  CONVERT_DOUBLE_CHECKED(to_number, args[2]);

  int start = FastD2I(from_number);
  int end = FastD2I(to_number);

  RUNTIME_ASSERT(end >= start);
  RUNTIME_ASSERT(start >= 0);
  RUNTIME_ASSERT(end <= value->length());
  return value->Slice(start, end);
}


static Object* Runtime_NumberToRadixString(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_DOUBLE_CHECKED(value, args[0]);
  if (isnan(value)) {
    return Heap::AllocateStringFromAscii(CStrVector("NaN"));
  }
  if (isinf(value)) {
    if (value < 0) {
      return Heap::AllocateStringFromAscii(CStrVector("-Infinity"));
    }
    return Heap::AllocateStringFromAscii(CStrVector("Infinity"));
  }
  CONVERT_DOUBLE_CHECKED(radix_number, args[1]);
  int radix = FastD2I(radix_number);
  RUNTIME_ASSERT(2 <= radix && radix <= 36);
  char* str = DoubleToRadixCString(value, radix);
  Object* result = Heap::AllocateStringFromAscii(CStrVector(str));
  DeleteArray(str);
  return result;
}


static Object* Runtime_NumberToFixed(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_DOUBLE_CHECKED(value, args[0]);
  if (isnan(value)) {
    return Heap::AllocateStringFromAscii(CStrVector("NaN"));
  }
  if (isinf(value)) {
    if (value < 0) {
      return Heap::AllocateStringFromAscii(CStrVector("-Infinity"));
    }
    return Heap::AllocateStringFromAscii(CStrVector("Infinity"));
  }
  CONVERT_DOUBLE_CHECKED(f_number, args[1]);
  int f = FastD2I(f_number);
  RUNTIME_ASSERT(f >= 0);
  char* str = DoubleToFixedCString(value, f);
  Object* res = Heap::AllocateStringFromAscii(CStrVector(str));
  DeleteArray(str);
  return res;
}


static Object* Runtime_NumberToExponential(Arguments args) {
  NoHandleAllocation ha;
  ASSERT(args.length() == 2);

  CONVERT_DOUBLE_CHECKED(value, args[0]);
  if (isnan(value)) {
    return Heap::AllocateStringFromAscii(CStrVector("NaN"));
  }
  if (isinf(value)) {
    if (value < 0) {
      return Heap::AllocateStringFromAscii(CStrVector("-Infinity"));
    }
    return Heap::AllocateStringFromAscii(CStrVector("Infinity"));
  }