| // Copyright 2014 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/runtime/runtime-utils.h" |
| |
| #include "src/arguments.h" |
| #include "src/regexp/jsregexp-inl.h" |
| #include "src/string-builder.h" |
| #include "src/string-search.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // This may return an empty MaybeHandle if an exception is thrown or |
| // we abort due to reaching the recursion limit. |
| MaybeHandle<String> StringReplaceOneCharWithString( |
| Isolate* isolate, Handle<String> subject, Handle<String> search, |
| Handle<String> replace, bool* found, int recursion_limit) { |
| StackLimitCheck stackLimitCheck(isolate); |
| if (stackLimitCheck.HasOverflowed() || (recursion_limit == 0)) { |
| return MaybeHandle<String>(); |
| } |
| recursion_limit--; |
| if (subject->IsConsString()) { |
| ConsString* cons = ConsString::cast(*subject); |
| Handle<String> first = Handle<String>(cons->first()); |
| Handle<String> second = Handle<String>(cons->second()); |
| Handle<String> new_first; |
| if (!StringReplaceOneCharWithString(isolate, first, search, replace, found, |
| recursion_limit).ToHandle(&new_first)) { |
| return MaybeHandle<String>(); |
| } |
| if (*found) return isolate->factory()->NewConsString(new_first, second); |
| |
| Handle<String> new_second; |
| if (!StringReplaceOneCharWithString(isolate, second, search, replace, found, |
| recursion_limit) |
| .ToHandle(&new_second)) { |
| return MaybeHandle<String>(); |
| } |
| if (*found) return isolate->factory()->NewConsString(first, new_second); |
| |
| return subject; |
| } else { |
| int index = String::IndexOf(isolate, subject, search, 0); |
| if (index == -1) return subject; |
| *found = true; |
| Handle<String> first = isolate->factory()->NewSubString(subject, 0, index); |
| Handle<String> cons1; |
| ASSIGN_RETURN_ON_EXCEPTION( |
| isolate, cons1, isolate->factory()->NewConsString(first, replace), |
| String); |
| Handle<String> second = |
| isolate->factory()->NewSubString(subject, index + 1, subject->length()); |
| return isolate->factory()->NewConsString(cons1, second); |
| } |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_StringReplaceOneCharWithString) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 3); |
| CONVERT_ARG_HANDLE_CHECKED(String, subject, 0); |
| CONVERT_ARG_HANDLE_CHECKED(String, search, 1); |
| CONVERT_ARG_HANDLE_CHECKED(String, replace, 2); |
| |
| // If the cons string tree is too deep, we simply abort the recursion and |
| // retry with a flattened subject string. |
| const int kRecursionLimit = 0x1000; |
| bool found = false; |
| Handle<String> result; |
| if (StringReplaceOneCharWithString(isolate, subject, search, replace, &found, |
| kRecursionLimit).ToHandle(&result)) { |
| return *result; |
| } |
| if (isolate->has_pending_exception()) return isolate->heap()->exception(); |
| |
| subject = String::Flatten(subject); |
| if (StringReplaceOneCharWithString(isolate, subject, search, replace, &found, |
| kRecursionLimit).ToHandle(&result)) { |
| return *result; |
| } |
| if (isolate->has_pending_exception()) return isolate->heap()->exception(); |
| // In case of empty handle and no pending exception we have stack overflow. |
| return isolate->StackOverflow(); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_StringIndexOf) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 3); |
| return String::IndexOf(isolate, args.at<Object>(0), args.at<Object>(1), |
| args.at<Object>(2)); |
| } |
| |
| RUNTIME_FUNCTION(Runtime_StringLastIndexOf) { |
| HandleScope handle_scope(isolate); |
| return String::LastIndexOf(isolate, args.at<Object>(0), args.at<Object>(1), |
| isolate->factory()->undefined_value()); |
| } |
| |
| RUNTIME_FUNCTION(Runtime_SubString) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 3); |
| |
| CONVERT_ARG_HANDLE_CHECKED(String, string, 0); |
| int start, end; |
| // We have a fast integer-only case here to avoid a conversion to double in |
| // the common case where from and to are Smis. |
| if (args[1]->IsSmi() && args[2]->IsSmi()) { |
| CONVERT_SMI_ARG_CHECKED(from_number, 1); |
| CONVERT_SMI_ARG_CHECKED(to_number, 2); |
| start = from_number; |
| end = to_number; |
| } else if (args[1]->IsNumber() && args[2]->IsNumber()) { |
| CONVERT_DOUBLE_ARG_CHECKED(from_number, 1); |
| CONVERT_DOUBLE_ARG_CHECKED(to_number, 2); |
| start = FastD2IChecked(from_number); |
| end = FastD2IChecked(to_number); |
| } else { |
| return isolate->ThrowIllegalOperation(); |
| } |
| // The following condition is intentionally robust because the SubStringStub |
| // delegates here and we test this in cctest/test-strings/RobustSubStringStub. |
| if (end < start || start < 0 || end > string->length()) { |
| return isolate->ThrowIllegalOperation(); |
| } |
| isolate->counters()->sub_string_runtime()->Increment(); |
| |
| return *isolate->factory()->NewSubString(string, start, end); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_StringAdd) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 2); |
| CONVERT_ARG_HANDLE_CHECKED(Object, obj1, 0); |
| CONVERT_ARG_HANDLE_CHECKED(Object, obj2, 1); |
| isolate->counters()->string_add_runtime()->Increment(); |
| MaybeHandle<String> maybe_str1(Object::ToString(isolate, obj1)); |
| MaybeHandle<String> maybe_str2(Object::ToString(isolate, obj2)); |
| Handle<String> str1; |
| Handle<String> str2; |
| maybe_str1.ToHandle(&str1); |
| maybe_str2.ToHandle(&str2); |
| RETURN_RESULT_OR_FAILURE(isolate, |
| isolate->factory()->NewConsString(str1, str2)); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_InternalizeString) { |
| HandleScope handles(isolate); |
| DCHECK(args.length() == 1); |
| CONVERT_ARG_HANDLE_CHECKED(String, string, 0); |
| return *isolate->factory()->InternalizeString(string); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_StringCharCodeAtRT) { |
| HandleScope handle_scope(isolate); |
| DCHECK(args.length() == 2); |
| |
| CONVERT_ARG_HANDLE_CHECKED(String, subject, 0); |
| CONVERT_NUMBER_CHECKED(uint32_t, i, Uint32, args[1]); |
| |
| // 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 = String::Flatten(subject); |
| |
| if (i >= static_cast<uint32_t>(subject->length())) { |
| return isolate->heap()->nan_value(); |
| } |
| |
| return Smi::FromInt(subject->Get(i)); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_StringCompare) { |
| HandleScope handle_scope(isolate); |
| DCHECK_EQ(2, args.length()); |
| CONVERT_ARG_HANDLE_CHECKED(String, x, 0); |
| CONVERT_ARG_HANDLE_CHECKED(String, y, 1); |
| isolate->counters()->string_compare_runtime()->Increment(); |
| switch (String::Compare(x, y)) { |
| case ComparisonResult::kLessThan: |
| return Smi::FromInt(LESS); |
| case ComparisonResult::kEqual: |
| return Smi::FromInt(EQUAL); |
| case ComparisonResult::kGreaterThan: |
| return Smi::FromInt(GREATER); |
| case ComparisonResult::kUndefined: |
| break; |
| } |
| UNREACHABLE(); |
| return Smi::kZero; |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_StringBuilderConcat) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 3); |
| CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0); |
| int32_t array_length; |
| if (!args[1]->ToInt32(&array_length)) { |
| THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError()); |
| } |
| CONVERT_ARG_HANDLE_CHECKED(String, special, 2); |
| |
| size_t actual_array_length = 0; |
| CHECK(TryNumberToSize(array->length(), &actual_array_length)); |
| CHECK(array_length >= 0); |
| CHECK(static_cast<size_t>(array_length) <= actual_array_length); |
| |
| // This assumption is used by the slice encoding in one or two smis. |
| DCHECK(Smi::kMaxValue >= String::kMaxLength); |
| |
| CHECK(array->HasFastElements()); |
| JSObject::EnsureCanContainHeapObjectElements(array); |
| |
| int special_length = special->length(); |
| if (!array->HasFastObjectElements()) { |
| return isolate->Throw(isolate->heap()->illegal_argument_string()); |
| } |
| |
| int length; |
| bool one_byte = special->HasOnlyOneByteChars(); |
| |
| { |
| DisallowHeapAllocation no_gc; |
| FixedArray* fixed_array = FixedArray::cast(array->elements()); |
| if (fixed_array->length() < array_length) { |
| array_length = fixed_array->length(); |
| } |
| |
| if (array_length == 0) { |
| return isolate->heap()->empty_string(); |
| } else if (array_length == 1) { |
| Object* first = fixed_array->get(0); |
| if (first->IsString()) return first; |
| } |
| length = StringBuilderConcatLength(special_length, fixed_array, |
| array_length, &one_byte); |
| } |
| |
| if (length == -1) { |
| return isolate->Throw(isolate->heap()->illegal_argument_string()); |
| } |
| |
| if (one_byte) { |
| Handle<SeqOneByteString> answer; |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION( |
| isolate, answer, isolate->factory()->NewRawOneByteString(length)); |
| StringBuilderConcatHelper(*special, answer->GetChars(), |
| FixedArray::cast(array->elements()), |
| array_length); |
| return *answer; |
| } else { |
| Handle<SeqTwoByteString> answer; |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION( |
| isolate, answer, isolate->factory()->NewRawTwoByteString(length)); |
| StringBuilderConcatHelper(*special, answer->GetChars(), |
| FixedArray::cast(array->elements()), |
| array_length); |
| return *answer; |
| } |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_StringBuilderJoin) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 3); |
| CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0); |
| int32_t array_length; |
| if (!args[1]->ToInt32(&array_length)) { |
| THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError()); |
| } |
| CONVERT_ARG_HANDLE_CHECKED(String, separator, 2); |
| CHECK(array->HasFastObjectElements()); |
| CHECK(array_length >= 0); |
| |
| Handle<FixedArray> fixed_array(FixedArray::cast(array->elements())); |
| if (fixed_array->length() < array_length) { |
| array_length = fixed_array->length(); |
| } |
| |
| if (array_length == 0) { |
| return isolate->heap()->empty_string(); |
| } else if (array_length == 1) { |
| Object* first = fixed_array->get(0); |
| CHECK(first->IsString()); |
| return first; |
| } |
| |
| int separator_length = separator->length(); |
| CHECK(separator_length > 0); |
| int max_nof_separators = |
| (String::kMaxLength + separator_length - 1) / separator_length; |
| if (max_nof_separators < (array_length - 1)) { |
| THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError()); |
| } |
| int length = (array_length - 1) * separator_length; |
| for (int i = 0; i < array_length; i++) { |
| Object* element_obj = fixed_array->get(i); |
| CHECK(element_obj->IsString()); |
| String* element = String::cast(element_obj); |
| int increment = element->length(); |
| if (increment > String::kMaxLength - length) { |
| STATIC_ASSERT(String::kMaxLength < kMaxInt); |
| length = kMaxInt; // Provoke exception; |
| break; |
| } |
| length += increment; |
| } |
| |
| Handle<SeqTwoByteString> answer; |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION( |
| isolate, answer, isolate->factory()->NewRawTwoByteString(length)); |
| |
| DisallowHeapAllocation no_gc; |
| |
| uc16* sink = answer->GetChars(); |
| #ifdef DEBUG |
| uc16* end = sink + length; |
| #endif |
| |
| CHECK(fixed_array->get(0)->IsString()); |
| String* first = String::cast(fixed_array->get(0)); |
| String* separator_raw = *separator; |
| |
| int first_length = first->length(); |
| String::WriteToFlat(first, sink, 0, first_length); |
| sink += first_length; |
| |
| for (int i = 1; i < array_length; i++) { |
| DCHECK(sink + separator_length <= end); |
| String::WriteToFlat(separator_raw, sink, 0, separator_length); |
| sink += separator_length; |
| |
| CHECK(fixed_array->get(i)->IsString()); |
| String* element = String::cast(fixed_array->get(i)); |
| int element_length = element->length(); |
| DCHECK(sink + element_length <= end); |
| String::WriteToFlat(element, sink, 0, element_length); |
| sink += element_length; |
| } |
| DCHECK(sink == end); |
| |
| // Use %_FastOneByteArrayJoin instead. |
| DCHECK(!answer->IsOneByteRepresentation()); |
| return *answer; |
| } |
| |
| template <typename sinkchar> |
| static void WriteRepeatToFlat(String* src, Vector<sinkchar> buffer, int cursor, |
| int repeat, int length) { |
| if (repeat == 0) return; |
| |
| sinkchar* start = &buffer[cursor]; |
| String::WriteToFlat<sinkchar>(src, start, 0, length); |
| |
| int done = 1; |
| sinkchar* next = start + length; |
| |
| while (done < repeat) { |
| int block = Min(done, repeat - done); |
| int block_chars = block * length; |
| CopyChars(next, start, block_chars); |
| next += block_chars; |
| done += block; |
| } |
| } |
| |
| template <typename Char> |
| static void JoinSparseArrayWithSeparator(FixedArray* elements, |
| int elements_length, |
| uint32_t array_length, |
| String* separator, |
| Vector<Char> buffer) { |
| DisallowHeapAllocation no_gc; |
| int previous_separator_position = 0; |
| int separator_length = separator->length(); |
| DCHECK_LT(0, separator_length); |
| int cursor = 0; |
| for (int i = 0; i < elements_length; i += 2) { |
| int position = NumberToInt32(elements->get(i)); |
| String* string = String::cast(elements->get(i + 1)); |
| int string_length = string->length(); |
| if (string->length() > 0) { |
| int repeat = position - previous_separator_position; |
| WriteRepeatToFlat<Char>(separator, buffer, cursor, repeat, |
| separator_length); |
| cursor += repeat * separator_length; |
| previous_separator_position = position; |
| String::WriteToFlat<Char>(string, &buffer[cursor], 0, string_length); |
| cursor += string->length(); |
| } |
| } |
| |
| int last_array_index = static_cast<int>(array_length - 1); |
| // Array length must be representable as a signed 32-bit number, |
| // otherwise the total string length would have been too large. |
| DCHECK(array_length <= 0x7fffffff); // Is int32_t. |
| int repeat = last_array_index - previous_separator_position; |
| WriteRepeatToFlat<Char>(separator, buffer, cursor, repeat, separator_length); |
| cursor += repeat * separator_length; |
| DCHECK(cursor <= buffer.length()); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_SparseJoinWithSeparator) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 3); |
| CONVERT_ARG_HANDLE_CHECKED(JSArray, elements_array, 0); |
| CONVERT_NUMBER_CHECKED(uint32_t, array_length, Uint32, args[1]); |
| CONVERT_ARG_HANDLE_CHECKED(String, separator, 2); |
| // elements_array is fast-mode JSarray of alternating positions |
| // (increasing order) and strings. |
| CHECK(elements_array->HasFastSmiOrObjectElements()); |
| // array_length is length of original array (used to add separators); |
| // separator is string to put between elements. Assumed to be non-empty. |
| CHECK(array_length > 0); |
| |
| // Find total length of join result. |
| int string_length = 0; |
| bool is_one_byte = separator->IsOneByteRepresentation(); |
| bool overflow = false; |
| CONVERT_NUMBER_CHECKED(int, elements_length, Int32, elements_array->length()); |
| CHECK(elements_length <= elements_array->elements()->length()); |
| CHECK((elements_length & 1) == 0); // Even length. |
| FixedArray* elements = FixedArray::cast(elements_array->elements()); |
| { |
| DisallowHeapAllocation no_gc; |
| for (int i = 0; i < elements_length; i += 2) { |
| String* string = String::cast(elements->get(i + 1)); |
| int length = string->length(); |
| if (is_one_byte && !string->IsOneByteRepresentation()) { |
| is_one_byte = false; |
| } |
| if (length > String::kMaxLength || |
| String::kMaxLength - length < string_length) { |
| overflow = true; |
| break; |
| } |
| string_length += length; |
| } |
| } |
| |
| int separator_length = separator->length(); |
| if (!overflow && separator_length > 0) { |
| if (array_length <= 0x7fffffffu) { |
| int separator_count = static_cast<int>(array_length) - 1; |
| int remaining_length = String::kMaxLength - string_length; |
| if ((remaining_length / separator_length) >= separator_count) { |
| string_length += separator_length * (array_length - 1); |
| } else { |
| // Not room for the separators within the maximal string length. |
| overflow = true; |
| } |
| } else { |
| // Nonempty separator and at least 2^31-1 separators necessary |
| // means that the string is too large to create. |
| STATIC_ASSERT(String::kMaxLength < 0x7fffffff); |
| overflow = true; |
| } |
| } |
| if (overflow) { |
| // Throw an exception if the resulting string is too large. See |
| // https://code.google.com/p/chromium/issues/detail?id=336820 |
| // for details. |
| THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError()); |
| } |
| |
| if (is_one_byte) { |
| Handle<SeqOneByteString> result = isolate->factory() |
| ->NewRawOneByteString(string_length) |
| .ToHandleChecked(); |
| JoinSparseArrayWithSeparator<uint8_t>( |
| FixedArray::cast(elements_array->elements()), elements_length, |
| array_length, *separator, |
| Vector<uint8_t>(result->GetChars(), string_length)); |
| return *result; |
| } else { |
| Handle<SeqTwoByteString> result = isolate->factory() |
| ->NewRawTwoByteString(string_length) |
| .ToHandleChecked(); |
| JoinSparseArrayWithSeparator<uc16>( |
| FixedArray::cast(elements_array->elements()), elements_length, |
| array_length, *separator, |
| Vector<uc16>(result->GetChars(), string_length)); |
| return *result; |
| } |
| } |
| |
| |
| // Copies Latin1 characters to the given fixed array looking up |
| // one-char strings in the cache. Gives up on the first char that is |
| // not in the cache and fills the remainder with smi zeros. Returns |
| // the length of the successfully copied prefix. |
| static int CopyCachedOneByteCharsToArray(Heap* heap, const uint8_t* chars, |
| FixedArray* elements, int length) { |
| DisallowHeapAllocation no_gc; |
| FixedArray* one_byte_cache = heap->single_character_string_cache(); |
| Object* undefined = heap->undefined_value(); |
| int i; |
| WriteBarrierMode mode = elements->GetWriteBarrierMode(no_gc); |
| for (i = 0; i < length; ++i) { |
| Object* value = one_byte_cache->get(chars[i]); |
| if (value == undefined) break; |
| elements->set(i, value, mode); |
| } |
| if (i < length) { |
| DCHECK(Smi::kZero == 0); |
| memset(elements->data_start() + i, 0, kPointerSize * (length - i)); |
| } |
| #ifdef DEBUG |
| for (int j = 0; j < length; ++j) { |
| Object* element = elements->get(j); |
| DCHECK(element == Smi::kZero || |
| (element->IsString() && String::cast(element)->LooksValid())); |
| } |
| #endif |
| return i; |
| } |
| |
| |
| // Converts a String to JSArray. |
| // For example, "foo" => ["f", "o", "o"]. |
| RUNTIME_FUNCTION(Runtime_StringToArray) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 2); |
| CONVERT_ARG_HANDLE_CHECKED(String, s, 0); |
| CONVERT_NUMBER_CHECKED(uint32_t, limit, Uint32, args[1]); |
| |
| s = String::Flatten(s); |
| const int length = static_cast<int>(Min<uint32_t>(s->length(), limit)); |
| |
| Handle<FixedArray> elements; |
| int position = 0; |
| if (s->IsFlat() && s->IsOneByteRepresentation()) { |
| // Try using cached chars where possible. |
| elements = isolate->factory()->NewUninitializedFixedArray(length); |
| |
| DisallowHeapAllocation no_gc; |
| String::FlatContent content = s->GetFlatContent(); |
| if (content.IsOneByte()) { |
| Vector<const uint8_t> chars = content.ToOneByteVector(); |
| // Note, this will initialize all elements (not only the prefix) |
| // to prevent GC from seeing partially initialized array. |
| position = CopyCachedOneByteCharsToArray(isolate->heap(), chars.start(), |
| *elements, length); |
| } else { |
| MemsetPointer(elements->data_start(), isolate->heap()->undefined_value(), |
| length); |
| } |
| } else { |
| elements = isolate->factory()->NewFixedArray(length); |
| } |
| for (int i = position; i < length; ++i) { |
| Handle<Object> str = |
| isolate->factory()->LookupSingleCharacterStringFromCode(s->Get(i)); |
| elements->set(i, *str); |
| } |
| |
| #ifdef DEBUG |
| for (int i = 0; i < length; ++i) { |
| DCHECK(String::cast(elements->get(i))->length() == 1); |
| } |
| #endif |
| |
| return *isolate->factory()->NewJSArrayWithElements(elements); |
| } |
| |
| |
| static inline bool ToUpperOverflows(uc32 character) { |
| // y with umlauts and the micro sign are the only characters that stop |
| // fitting into one-byte when converting to uppercase. |
| static const uc32 yuml_code = 0xff; |
| static const uc32 micro_code = 0xb5; |
| return (character == yuml_code || character == micro_code); |
| } |
| |
| |
| template <class Converter> |
| MUST_USE_RESULT static Object* ConvertCaseHelper( |
| Isolate* isolate, String* string, SeqString* result, int result_length, |
| unibrow::Mapping<Converter, 128>* mapping) { |
| DisallowHeapAllocation no_gc; |
| // We try this twice, once with the assumption that the result is no longer |
| // than the input and, if that assumption breaks, again with the exact |
| // length. This may not be pretty, but it is nicer than what was here before |
| // and I hereby claim my vaffel-is. |
| // |
| // NOTE: This assumes that the upper/lower case of an ASCII |
| // character is also ASCII. This is currently the case, but it |
| // might break in the future if we implement more context and locale |
| // dependent upper/lower conversions. |
| bool has_changed_character = false; |
| |
| // Convert all characters to upper case, assuming that they will fit |
| // in the buffer |
| StringCharacterStream stream(string); |
| unibrow::uchar chars[Converter::kMaxWidth]; |
| // We can assume that the string is not empty |
| uc32 current = stream.GetNext(); |
| bool ignore_overflow = Converter::kIsToLower || result->IsSeqTwoByteString(); |
| for (int i = 0; i < result_length;) { |
| bool has_next = stream.HasMore(); |
| uc32 next = has_next ? stream.GetNext() : 0; |
| int char_length = mapping->get(current, next, chars); |
| if (char_length == 0) { |
| // The case conversion of this character is the character itself. |
| result->Set(i, current); |
| i++; |
| } else if (char_length == 1 && |
| (ignore_overflow || !ToUpperOverflows(current))) { |
| // Common case: converting the letter resulted in one character. |
| DCHECK(static_cast<uc32>(chars[0]) != current); |
| result->Set(i, chars[0]); |
| has_changed_character = true; |
| i++; |
| } else if (result_length == string->length()) { |
| bool overflows = ToUpperOverflows(current); |
| // We've assumed that the result would be as long as the |
| // input but here is a character that converts to several |
| // characters. No matter, we calculate the exact length |
| // of the result and try the whole thing again. |
| // |
| // Note that this leaves room for optimization. We could just |
| // memcpy what we already have to the result string. Also, |
| // the result string is the last object allocated we could |
| // "realloc" it and probably, in the vast majority of cases, |
| // extend the existing string to be able to hold the full |
| // result. |
| int next_length = 0; |
| if (has_next) { |
| next_length = mapping->get(next, 0, chars); |
| if (next_length == 0) next_length = 1; |
| } |
| int current_length = i + char_length + next_length; |
| while (stream.HasMore()) { |
| current = stream.GetNext(); |
| overflows |= ToUpperOverflows(current); |
| // NOTE: we use 0 as the next character here because, while |
| // the next character may affect what a character converts to, |
| // it does not in any case affect the length of what it convert |
| // to. |
| int char_length = mapping->get(current, 0, chars); |
| if (char_length == 0) char_length = 1; |
| current_length += char_length; |
| if (current_length > String::kMaxLength) { |
| AllowHeapAllocation allocate_error_and_return; |
| THROW_NEW_ERROR_RETURN_FAILURE(isolate, |
| NewInvalidStringLengthError()); |
| } |
| } |
| // Try again with the real length. Return signed if we need |
| // to allocate a two-byte string for to uppercase. |
| return (overflows && !ignore_overflow) ? Smi::FromInt(-current_length) |
| : Smi::FromInt(current_length); |
| } else { |
| for (int j = 0; j < char_length; j++) { |
| result->Set(i, chars[j]); |
| i++; |
| } |
| has_changed_character = true; |
| } |
| current = next; |
| } |
| if (has_changed_character) { |
| return result; |
| } else { |
| // If we didn't actually change anything in doing the conversion |
| // we simple return the result and let the converted string |
| // become garbage; there is no reason to keep two identical strings |
| // alive. |
| return string; |
| } |
| } |
| |
| |
| static const uintptr_t kOneInEveryByte = kUintptrAllBitsSet / 0xFF; |
| static const uintptr_t kAsciiMask = kOneInEveryByte << 7; |
| |
| // Given a word and two range boundaries returns a word with high bit |
| // set in every byte iff the corresponding input byte was strictly in |
| // the range (m, n). All the other bits in the result are cleared. |
| // This function is only useful when it can be inlined and the |
| // boundaries are statically known. |
| // Requires: all bytes in the input word and the boundaries must be |
| // ASCII (less than 0x7F). |
| static inline uintptr_t AsciiRangeMask(uintptr_t w, char m, char n) { |
| // Use strict inequalities since in edge cases the function could be |
| // further simplified. |
| DCHECK(0 < m && m < n); |
| // Has high bit set in every w byte less than n. |
| uintptr_t tmp1 = kOneInEveryByte * (0x7F + n) - w; |
| // Has high bit set in every w byte greater than m. |
| uintptr_t tmp2 = w + kOneInEveryByte * (0x7F - m); |
| return (tmp1 & tmp2 & (kOneInEveryByte * 0x80)); |
| } |
| |
| |
| #ifdef DEBUG |
| static bool CheckFastAsciiConvert(char* dst, const char* src, int length, |
| bool changed, bool is_to_lower) { |
| bool expected_changed = false; |
| for (int i = 0; i < length; i++) { |
| if (dst[i] == src[i]) continue; |
| expected_changed = true; |
| if (is_to_lower) { |
| DCHECK('A' <= src[i] && src[i] <= 'Z'); |
| DCHECK(dst[i] == src[i] + ('a' - 'A')); |
| } else { |
| DCHECK('a' <= src[i] && src[i] <= 'z'); |
| DCHECK(dst[i] == src[i] - ('a' - 'A')); |
| } |
| } |
| return (expected_changed == changed); |
| } |
| #endif |
| |
| |
| template <class Converter> |
| static bool FastAsciiConvert(char* dst, const char* src, int length, |
| bool* changed_out) { |
| #ifdef DEBUG |
| char* saved_dst = dst; |
| const char* saved_src = src; |
| #endif |
| DisallowHeapAllocation no_gc; |
| // We rely on the distance between upper and lower case letters |
| // being a known power of 2. |
| DCHECK('a' - 'A' == (1 << 5)); |
| // Boundaries for the range of input characters than require conversion. |
| static const char lo = Converter::kIsToLower ? 'A' - 1 : 'a' - 1; |
| static const char hi = Converter::kIsToLower ? 'Z' + 1 : 'z' + 1; |
| bool changed = false; |
| uintptr_t or_acc = 0; |
| const char* const limit = src + length; |
| |
| // dst is newly allocated and always aligned. |
| DCHECK(IsAligned(reinterpret_cast<intptr_t>(dst), sizeof(uintptr_t))); |
| // Only attempt processing one word at a time if src is also aligned. |
| if (IsAligned(reinterpret_cast<intptr_t>(src), sizeof(uintptr_t))) { |
| // Process the prefix of the input that requires no conversion one aligned |
| // (machine) word at a time. |
| while (src <= limit - sizeof(uintptr_t)) { |
| const uintptr_t w = *reinterpret_cast<const uintptr_t*>(src); |
| or_acc |= w; |
| if (AsciiRangeMask(w, lo, hi) != 0) { |
| changed = true; |
| break; |
| } |
| *reinterpret_cast<uintptr_t*>(dst) = w; |
| src += sizeof(uintptr_t); |
| dst += sizeof(uintptr_t); |
| } |
| // Process the remainder of the input performing conversion when |
| // required one word at a time. |
| while (src <= limit - sizeof(uintptr_t)) { |
| const uintptr_t w = *reinterpret_cast<const uintptr_t*>(src); |
| or_acc |= w; |
| uintptr_t m = AsciiRangeMask(w, lo, hi); |
| // The mask has high (7th) bit set in every byte that needs |
| // conversion and we know that the distance between cases is |
| // 1 << 5. |
| *reinterpret_cast<uintptr_t*>(dst) = w ^ (m >> 2); |
| src += sizeof(uintptr_t); |
| dst += sizeof(uintptr_t); |
| } |
| } |
| // Process the last few bytes of the input (or the whole input if |
| // unaligned access is not supported). |
| while (src < limit) { |
| char c = *src; |
| or_acc |= c; |
| if (lo < c && c < hi) { |
| c ^= (1 << 5); |
| changed = true; |
| } |
| *dst = c; |
| ++src; |
| ++dst; |
| } |
| |
| if ((or_acc & kAsciiMask) != 0) return false; |
| |
| DCHECK(CheckFastAsciiConvert(saved_dst, saved_src, length, changed, |
| Converter::kIsToLower)); |
| |
| *changed_out = changed; |
| return true; |
| } |
| |
| |
| template <class Converter> |
| MUST_USE_RESULT static Object* ConvertCase( |
| Handle<String> s, Isolate* isolate, |
| unibrow::Mapping<Converter, 128>* mapping) { |
| s = String::Flatten(s); |
| int length = s->length(); |
| // Assume that the string is not empty; we need this assumption later |
| if (length == 0) return *s; |
| |
| // Simpler handling of ASCII strings. |
| // |
| // NOTE: This assumes that the upper/lower case of an ASCII |
| // character is also ASCII. This is currently the case, but it |
| // might break in the future if we implement more context and locale |
| // dependent upper/lower conversions. |
| if (s->IsOneByteRepresentationUnderneath()) { |
| // Same length as input. |
| Handle<SeqOneByteString> result = |
| isolate->factory()->NewRawOneByteString(length).ToHandleChecked(); |
| DisallowHeapAllocation no_gc; |
| String::FlatContent flat_content = s->GetFlatContent(); |
| DCHECK(flat_content.IsFlat()); |
| bool has_changed_character = false; |
| bool is_ascii = FastAsciiConvert<Converter>( |
| reinterpret_cast<char*>(result->GetChars()), |
| reinterpret_cast<const char*>(flat_content.ToOneByteVector().start()), |
| length, &has_changed_character); |
| // If not ASCII, we discard the result and take the 2 byte path. |
| if (is_ascii) return has_changed_character ? *result : *s; |
| } |
| |
| Handle<SeqString> result; // Same length as input. |
| if (s->IsOneByteRepresentation()) { |
| result = isolate->factory()->NewRawOneByteString(length).ToHandleChecked(); |
| } else { |
| result = isolate->factory()->NewRawTwoByteString(length).ToHandleChecked(); |
| } |
| |
| Object* answer = ConvertCaseHelper(isolate, *s, *result, length, mapping); |
| if (answer->IsException(isolate) || answer->IsString()) return answer; |
| |
| DCHECK(answer->IsSmi()); |
| length = Smi::cast(answer)->value(); |
| if (s->IsOneByteRepresentation() && length > 0) { |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION( |
| isolate, result, isolate->factory()->NewRawOneByteString(length)); |
| } else { |
| if (length < 0) length = -length; |
| ASSIGN_RETURN_FAILURE_ON_EXCEPTION( |
| isolate, result, isolate->factory()->NewRawTwoByteString(length)); |
| } |
| return ConvertCaseHelper(isolate, *s, *result, length, mapping); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_StringToLowerCase) { |
| HandleScope scope(isolate); |
| DCHECK_EQ(args.length(), 1); |
| CONVERT_ARG_HANDLE_CHECKED(String, s, 0); |
| return ConvertCase(s, isolate, isolate->runtime_state()->to_lower_mapping()); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_StringToUpperCase) { |
| HandleScope scope(isolate); |
| DCHECK_EQ(args.length(), 1); |
| CONVERT_ARG_HANDLE_CHECKED(String, s, 0); |
| return ConvertCase(s, isolate, isolate->runtime_state()->to_upper_mapping()); |
| } |
| |
| RUNTIME_FUNCTION(Runtime_StringLessThan) { |
| HandleScope handle_scope(isolate); |
| DCHECK_EQ(2, args.length()); |
| CONVERT_ARG_HANDLE_CHECKED(String, x, 0); |
| CONVERT_ARG_HANDLE_CHECKED(String, y, 1); |
| switch (String::Compare(x, y)) { |
| case ComparisonResult::kLessThan: |
| return isolate->heap()->true_value(); |
| case ComparisonResult::kEqual: |
| case ComparisonResult::kGreaterThan: |
| return isolate->heap()->false_value(); |
| case ComparisonResult::kUndefined: |
| break; |
| } |
| UNREACHABLE(); |
| return Smi::kZero; |
| } |
| |
| RUNTIME_FUNCTION(Runtime_StringLessThanOrEqual) { |
| HandleScope handle_scope(isolate); |
| DCHECK_EQ(2, args.length()); |
| CONVERT_ARG_HANDLE_CHECKED(String, x, 0); |
| CONVERT_ARG_HANDLE_CHECKED(String, y, 1); |
| switch (String::Compare(x, y)) { |
| case ComparisonResult::kEqual: |
| case ComparisonResult::kLessThan: |
| return isolate->heap()->true_value(); |
| case ComparisonResult::kGreaterThan: |
| return isolate->heap()->false_value(); |
| case ComparisonResult::kUndefined: |
| break; |
| } |
| UNREACHABLE(); |
| return Smi::kZero; |
| } |
| |
| RUNTIME_FUNCTION(Runtime_StringGreaterThan) { |
| HandleScope handle_scope(isolate); |
| DCHECK_EQ(2, args.length()); |
| CONVERT_ARG_HANDLE_CHECKED(String, x, 0); |
| CONVERT_ARG_HANDLE_CHECKED(String, y, 1); |
| switch (String::Compare(x, y)) { |
| case ComparisonResult::kGreaterThan: |
| return isolate->heap()->true_value(); |
| case ComparisonResult::kEqual: |
| case ComparisonResult::kLessThan: |
| return isolate->heap()->false_value(); |
| case ComparisonResult::kUndefined: |
| break; |
| } |
| UNREACHABLE(); |
| return Smi::kZero; |
| } |
| |
| RUNTIME_FUNCTION(Runtime_StringGreaterThanOrEqual) { |
| HandleScope handle_scope(isolate); |
| DCHECK_EQ(2, args.length()); |
| CONVERT_ARG_HANDLE_CHECKED(String, x, 0); |
| CONVERT_ARG_HANDLE_CHECKED(String, y, 1); |
| switch (String::Compare(x, y)) { |
| case ComparisonResult::kEqual: |
| case ComparisonResult::kGreaterThan: |
| return isolate->heap()->true_value(); |
| case ComparisonResult::kLessThan: |
| return isolate->heap()->false_value(); |
| case ComparisonResult::kUndefined: |
| break; |
| } |
| UNREACHABLE(); |
| return Smi::kZero; |
| } |
| |
| RUNTIME_FUNCTION(Runtime_StringEqual) { |
| HandleScope handle_scope(isolate); |
| DCHECK_EQ(2, args.length()); |
| CONVERT_ARG_HANDLE_CHECKED(String, x, 0); |
| CONVERT_ARG_HANDLE_CHECKED(String, y, 1); |
| return isolate->heap()->ToBoolean(String::Equals(x, y)); |
| } |
| |
| RUNTIME_FUNCTION(Runtime_StringNotEqual) { |
| HandleScope handle_scope(isolate); |
| DCHECK_EQ(2, args.length()); |
| CONVERT_ARG_HANDLE_CHECKED(String, x, 0); |
| CONVERT_ARG_HANDLE_CHECKED(String, y, 1); |
| return isolate->heap()->ToBoolean(!String::Equals(x, y)); |
| } |
| |
| RUNTIME_FUNCTION(Runtime_FlattenString) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 1); |
| CONVERT_ARG_HANDLE_CHECKED(String, str, 0); |
| return *String::Flatten(str); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_StringCharFromCode) { |
| HandleScope handlescope(isolate); |
| DCHECK_EQ(1, args.length()); |
| if (args[0]->IsNumber()) { |
| CONVERT_NUMBER_CHECKED(uint32_t, code, Uint32, args[0]); |
| code &= 0xffff; |
| return *isolate->factory()->LookupSingleCharacterStringFromCode(code); |
| } |
| return isolate->heap()->empty_string(); |
| } |
| |
| RUNTIME_FUNCTION(Runtime_ExternalStringGetChar) { |
| SealHandleScope shs(isolate); |
| DCHECK_EQ(2, args.length()); |
| CONVERT_ARG_CHECKED(ExternalString, string, 0); |
| CONVERT_INT32_ARG_CHECKED(index, 1); |
| return Smi::FromInt(string->Get(index)); |
| } |
| |
| RUNTIME_FUNCTION(Runtime_StringCharCodeAt) { |
| SealHandleScope shs(isolate); |
| DCHECK(args.length() == 2); |
| if (!args[0]->IsString()) return isolate->heap()->undefined_value(); |
| if (!args[1]->IsNumber()) return isolate->heap()->undefined_value(); |
| if (std::isinf(args.number_at(1))) return isolate->heap()->nan_value(); |
| return __RT_impl_Runtime_StringCharCodeAtRT(args, isolate); |
| } |
| |
| } // namespace internal |
| } // namespace v8 |