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deps/v8/src/runtime/runtime-strings.cc
615 строк
22 KB
Michaël Zasso
deps: update V8 to 14.1.146.11
04 окт 2025, 19:47
Не верифицирован
04 окт 2025, 19:47
7772a2d
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// 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/execution/arguments-inl.h" #include "src/heap/heap-inl.h" #include "src/numbers/conversions.h" #include "src/objects/js-array-inl.h" #include "src/objects/objects-inl.h" #include "src/objects/slots.h" #include "src/objects/smi.h" #include "src/runtime/runtime-utils.h" #include "src/strings/string-builder-inl.h" #include "src/strings/unicode-inl.h" namespace v8 { namespace internal { RUNTIME_FUNCTION(Runtime_GetSubstitution) { HandleScope scope(isolate); DCHECK_EQ(5, args.length()); DirectHandle<String> matched = args.at<String>(0); DirectHandle<String> subject = args.at<String>(1); int position = args.smi_value_at(2); DirectHandle<String> replacement = args.at<String>(3); int start_index = args.smi_value_at(4); // A simple match without captures. class SimpleMatch : public String::Match { public: SimpleMatch(DirectHandle<String> match, DirectHandle<String> prefix, DirectHandle<String> suffix) : match_(match), prefix_(prefix), suffix_(suffix) {} DirectHandle<String> GetMatch() override { return match_; } DirectHandle<String> GetPrefix() override { return prefix_; } DirectHandle<String> GetSuffix() override { return suffix_; } int CaptureCount() override { return 0; } bool HasNamedCaptures() override { return false; } MaybeDirectHandle<String> GetCapture(int i, bool* capture_exists) override { *capture_exists = false; return match_; // Return arbitrary string handle. } MaybeDirectHandle<String> GetNamedCapture(DirectHandle<String> name, CaptureState* state) override { UNREACHABLE(); } private: DirectHandle<String> match_, prefix_, suffix_; }; DirectHandle<String> prefix = isolate->factory()->NewSubString(subject, 0, position); DirectHandle<String> suffix = isolate->factory()->NewSubString( subject, position + matched->length(), subject->length()); SimpleMatch match(matched, prefix, suffix); RETURN_RESULT_OR_FAILURE( isolate, String::GetSubstitution(isolate, &match, replacement, start_index)); } // This may return an empty MaybeDirectHandle if an exception is thrown or // we abort due to reaching the recursion limit. MaybeDirectHandle<String> StringReplaceOneCharWithString( Isolate* isolate, DirectHandle<String> subject, DirectHandle<String> search, DirectHandle<String> replace, bool* found, int recursion_limit) { StackLimitCheck stackLimitCheck(isolate); if (stackLimitCheck.HasOverflowed() || (recursion_limit == 0)) { return MaybeDirectHandle<String>(); } recursion_limit--; if (IsConsString(*subject)) { Tagged<ConsString> cons = Cast<ConsString>(*subject); DirectHandle<String> first(cons->first(), isolate); DirectHandle<String> second(cons->second(), isolate); DirectHandle<String> new_first; if (!StringReplaceOneCharWithString(isolate, first, search, replace, found, recursion_limit).ToHandle(&new_first)) { return MaybeDirectHandle<String>(); } if (*found) return isolate->factory()->NewConsString(new_first, second); DirectHandle<String> new_second; if (!StringReplaceOneCharWithString(isolate, second, search, replace, found, recursion_limit) .ToHandle(&new_second)) { return MaybeDirectHandle<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; DirectHandle<String> first = isolate->factory()->NewSubString(subject, 0, index); DirectHandle<String> cons1; ASSIGN_RETURN_ON_EXCEPTION( isolate, cons1, isolate->factory()->NewConsString(first, replace)); DirectHandle<String> second = isolate->factory()->NewSubString(subject, index + 1, subject->length()); return isolate->factory()->NewConsString(cons1, second); } } RUNTIME_FUNCTION(Runtime_StringReplaceOneCharWithString) { HandleScope scope(isolate); DCHECK_EQ(3, args.length()); DirectHandle<String> subject = args.at<String>(0); DirectHandle<String> search = args.at<String>(1); DirectHandle<String> replace = args.at<String>(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; DirectHandle<String> result; if (StringReplaceOneCharWithString(isolate, subject, search, replace, &found, kRecursionLimit).ToHandle(&result)) { return *result; } if (isolate->has_exception()) return ReadOnlyRoots(isolate).exception(); subject = String::Flatten(isolate, subject); if (StringReplaceOneCharWithString(isolate, subject, search, replace, &found, kRecursionLimit).ToHandle(&result)) { return *result; } if (isolate->has_exception()) return ReadOnlyRoots(isolate).exception(); // In case of empty handle and no exception we have stack overflow. return isolate->StackOverflow(); } RUNTIME_FUNCTION(Runtime_StringLastIndexOf) { HandleScope handle_scope(isolate); return String::LastIndexOf(isolate, args.at(0), args.at(1), isolate->factory()->undefined_value()); } RUNTIME_FUNCTION(Runtime_StringSubstring) { HandleScope scope(isolate); DCHECK_EQ(3, args.length()); DirectHandle<String> string = args.at<String>(0); int start = args.smi_value_at(1); int end = args.smi_value_at(2); DCHECK_LE(0, start); DCHECK_LE(start, end); DCHECK_LE(end, string->length()); return *isolate->factory()->NewSubString(string, start, end); } RUNTIME_FUNCTION(Runtime_StringAdd) { HandleScope scope(isolate); DCHECK_EQ(2, args.length()); DirectHandle<String> str1 = args.at<String>(0); DirectHandle<String> str2 = args.at<String>(1); RETURN_RESULT_OR_FAILURE(isolate, isolate->factory()->NewConsString(str1, str2)); } namespace { using ASVariant = AddStringConstantAndInternalizeVariant; Tagged<Object> StringAdd_StringConstant_Internalize( Isolate* isolate, DirectHandle<Object> lhs, DirectHandle<Object> rhs, Handle<HeapObject> maybe_feedback_vector, int slot_index, ASVariant as_variant) { const bool lhs_is_string_constant = as_variant == ASVariant::kLhsIsStringConstant; DirectHandle<Object> const_str_operand = lhs_is_string_constant ? lhs : rhs; DirectHandle<Object> other_operand = lhs_is_string_constant ? rhs : lhs; DCHECK(IsInternalizedString(*const_str_operand)); DirectHandle<String> other_operand_string; if (IsString(*other_operand)) { other_operand_string = Cast<String>(other_operand); } else { // According to spec we first have to do ToPrimitive and only then // ToString. // https://tc39.es/ecma262/#sec-applystringornumericbinaryoperator ASSIGN_RETURN_FAILURE_ON_EXCEPTION( isolate, other_operand, Object::ToPrimitive(isolate, other_operand)); ASSIGN_RETURN_FAILURE_ON_EXCEPTION( isolate, other_operand_string, Object::ToString(isolate, other_operand)); } auto f = isolate->factory(); auto other_operand_internalize = IsInternalizedString(*other_operand_string) ? Cast<InternalizedString>(other_operand_string) : f->InternalizeString(other_operand_string); auto lhs_internalize = lhs_is_string_constant ? Cast<String>(const_str_operand) : Cast<String>(other_operand_internalize); auto rhs_internalize = lhs_is_string_constant ? Cast<String>(other_operand_internalize) : Cast<String>(const_str_operand); if (IsUndefined(*maybe_feedback_vector)) { DirectHandle<String> cons; ASSIGN_RETURN_FAILURE_ON_EXCEPTION( isolate, cons, f->NewConsString(lhs_internalize, rhs_internalize)); return *f->InternalizeString(cons); } auto feedback_vector = Cast<FeedbackVector>(maybe_feedback_vector); FeedbackSlot cache_slot(FeedbackVector::ToSlot( slot_index + kAdd_StringConstant_Internalize_CacheSlotOffset)); DCHECK_LT(cache_slot.ToInt(), feedback_vector->length()); Handle<Object> cache_obj(Cast<Object>(feedback_vector->Get(cache_slot)), isolate); Handle<SimpleNameDictionary> cache; if (*cache_obj == ReadOnlyRoots{isolate}.uninitialized_symbol()) { cache = SimpleNameDictionary::New(isolate, 1); feedback_vector->SynchronizedSet(cache_slot, *cache); } else { cache = Cast<SimpleNameDictionary>(cache_obj); } InternalIndex entry = cache->FindEntry(isolate, other_operand_internalize); if (entry.is_found()) { auto result = cache->ValueAt(entry); DCHECK(IsInternalizedString(result)); return result; } DirectHandle<String> cons; ASSIGN_RETURN_FAILURE_ON_EXCEPTION( isolate, cons, f->NewConsString(lhs_internalize, rhs_internalize)); auto internalized = f->InternalizeString(cons); auto new_cache = SimpleNameDictionary::Set( isolate, cache, other_operand_internalize, internalized); if (*new_cache != *cache) { feedback_vector->SynchronizedSet(cache_slot, *new_cache); } return *internalized; } } // namespace RUNTIME_FUNCTION(Runtime_StringAdd_LhsIsStringConstant_Internalize) { HandleScope scope(isolate); DCHECK_EQ(4, args.length()); DirectHandle<String> lhs = args.at<String>(0); DirectHandle<Object> rhs = args.at<Object>(1); Handle<HeapObject> maybe_feedback_vector = args.at<HeapObject>(2); int slot_index = args.tagged_index_value_at(3); return StringAdd_StringConstant_Internalize(isolate, lhs, rhs, maybe_feedback_vector, slot_index, ASVariant::kLhsIsStringConstant); } RUNTIME_FUNCTION(Runtime_StringAdd_RhsIsStringConstant_Internalize) { HandleScope scope(isolate); DCHECK_EQ(4, args.length()); DirectHandle<Object> lhs = args.at<Object>(0); DirectHandle<String> rhs = args.at<String>(1); Handle<HeapObject> maybe_feedback_vector = args.at<HeapObject>(2); int slot_index = args.tagged_index_value_at(3); return StringAdd_StringConstant_Internalize(isolate, lhs, rhs, maybe_feedback_vector, slot_index, ASVariant::kRhsIsStringConstant); } RUNTIME_FUNCTION(Runtime_InternalizeString) { HandleScope handles(isolate); DCHECK_EQ(1, args.length()); DirectHandle<String> string = args.at<String>(0); return *isolate->factory()->InternalizeString(string); } RUNTIME_FUNCTION(Runtime_StringCharCodeAt) { HandleScope handle_scope(isolate); DCHECK_EQ(2, args.length()); DirectHandle<String> subject = args.at<String>(0); uint32_t i = NumberToUint32(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(isolate, subject); if (i >= static_cast<uint32_t>(subject->length())) { return ReadOnlyRoots(isolate).nan_value(); } return Smi::FromInt(subject->Get(i)); } RUNTIME_FUNCTION(Runtime_StringCodePointAt) { HandleScope handle_scope(isolate); DCHECK_EQ(2, args.length()); DirectHandle<String> subject = args.at<String>(0); uint32_t i = NumberToUint32(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(isolate, subject); if (i >= static_cast<uint32_t>(subject->length())) { return ReadOnlyRoots(isolate).nan_value(); } int first_code_point = subject->Get(i); if ((first_code_point & 0xFC00) != 0xD800) { return Smi::FromInt(first_code_point); } if (i + 1 >= static_cast<uint32_t>(subject->length())) { return Smi::FromInt(first_code_point); } int second_code_point = subject->Get(i + 1); if ((second_code_point & 0xFC00) != 0xDC00) { return Smi::FromInt(first_code_point); } int surrogate_offset = 0x10000 - (0xD800 << 10) - 0xDC00; return Smi::FromInt((first_code_point << 10) + (second_code_point + surrogate_offset)); } RUNTIME_FUNCTION(Runtime_StringBuilderConcat) { HandleScope scope(isolate); DCHECK_EQ(3, args.length()); DirectHandle<FixedArray> array = args.at<FixedArray>(0); int array_length = args.smi_value_at(1); DirectHandle<String> special = args.at<String>(2); // This assumption is used by the slice encoding in one or two smis. DCHECK_GE(Smi::kMaxValue, String::kMaxLength); int special_length = special->length(); int length; bool one_byte = special->IsOneByteRepresentation(); { DisallowGarbageCollection no_gc; Tagged<FixedArray> fixed_array = *array; if (array_length == 0) { return ReadOnlyRoots(isolate).empty_string(); } else if (array_length == 1) { Tagged<Object> first = fixed_array->get(0); if (IsString(first)) return first; } length = StringBuilderConcatLength(special_length, fixed_array, array_length, &one_byte); } if (length == -1) { return isolate->Throw(ReadOnlyRoots(isolate).illegal_argument_string()); } if (length == 0) { return ReadOnlyRoots(isolate).empty_string(); } if (one_byte) { DirectHandle<SeqOneByteString> answer; ASSIGN_RETURN_FAILURE_ON_EXCEPTION( isolate, answer, isolate->factory()->NewRawOneByteString(length)); DisallowGarbageCollection no_gc; StringBuilderConcatHelper(*special, answer->GetChars(no_gc), *array, array_length); return *answer; } else { DirectHandle<SeqTwoByteString> answer; ASSIGN_RETURN_FAILURE_ON_EXCEPTION( isolate, answer, isolate->factory()->NewRawTwoByteString(length)); DisallowGarbageCollection no_gc; StringBuilderConcatHelper(*special, answer->GetChars(no_gc), *array, array_length); return *answer; } } // Converts a String to JSArray. // For example, "foo" => ["f", "o", "o"]. RUNTIME_FUNCTION(Runtime_StringToArray) { HandleScope scope(isolate); DCHECK_EQ(2, args.length()); DirectHandle<String> s = args.at<String>(0); uint32_t limit = NumberToUint32(args[1]); s = String::Flatten(isolate, s); const int length = static_cast<int>(std::min(static_cast<uint32_t>(s->length()), limit)); DirectHandle<FixedArray> elements = isolate->factory()->NewFixedArray(length); bool elements_are_initialized = false; if (s->IsFlat() && s->IsOneByteRepresentation()) { DisallowGarbageCollection no_gc; String::FlatContent content = s->GetFlatContent(no_gc); // Use pre-initialized single characters to initialize all the elements. // This can be false if the string is sliced from an externalized // two-byte string that has only one-byte chars, in that case we will do // a LookupSingleCharacterStringFromCode for each of the characters. if (content.IsOneByte()) { base::Vector<const uint8_t> chars = content.ToOneByteVector(); ReadOnlyRoots roots(isolate); for (int i = 0; i < length; ++i) { Tagged<String> value = roots.single_character_string(chars[i]); DCHECK(ReadOnlyHeap::Contains(Cast<HeapObject>(value))); // The single-character strings are in RO space so it should // be safe to skip the write barriers. elements->set(i, value, SKIP_WRITE_BARRIER); } elements_are_initialized = true; } } if (!elements_are_initialized) { for (int i = 0; i < length; ++i) { DirectHandle<Object> str = isolate->factory()->LookupSingleCharacterStringFromCode(s->Get(i)); elements->set(i, *str); } } #ifdef DEBUG for (int i = 0; i < length; ++i) { DCHECK_EQ(Cast<String>(elements->get(i))->length(), 1); } #endif return *isolate->factory()->NewJSArrayWithElements(elements); } RUNTIME_FUNCTION(Runtime_StringLessThan) { HandleScope handle_scope(isolate); DCHECK_EQ(2, args.length()); DirectHandle<String> x = args.at<String>(0); DirectHandle<String> y = args.at<String>(1); ComparisonResult result = String::Compare(isolate, x, y); DCHECK_NE(result, ComparisonResult::kUndefined); return isolate->heap()->ToBoolean( ComparisonResultToBool(Operation::kLessThan, result)); } RUNTIME_FUNCTION(Runtime_StringLessThanOrEqual) { HandleScope handle_scope(isolate); DCHECK_EQ(2, args.length()); DirectHandle<String> x = args.at<String>(0); DirectHandle<String> y = args.at<String>(1); ComparisonResult result = String::Compare(isolate, x, y); DCHECK_NE(result, ComparisonResult::kUndefined); return isolate->heap()->ToBoolean( ComparisonResultToBool(Operation::kLessThanOrEqual, result)); } RUNTIME_FUNCTION(Runtime_StringGreaterThan) { HandleScope handle_scope(isolate); DCHECK_EQ(2, args.length()); DirectHandle<String> x = args.at<String>(0); DirectHandle<String> y = args.at<String>(1); ComparisonResult result = String::Compare(isolate, x, y); DCHECK_NE(result, ComparisonResult::kUndefined); return isolate->heap()->ToBoolean( ComparisonResultToBool(Operation::kGreaterThan, result)); } RUNTIME_FUNCTION(Runtime_StringGreaterThanOrEqual) { HandleScope handle_scope(isolate); DCHECK_EQ(2, args.length()); DirectHandle<String> x = args.at<String>(0); DirectHandle<String> y = args.at<String>(1); ComparisonResult result = String::Compare(isolate, x, y); DCHECK_NE(result, ComparisonResult::kUndefined); return isolate->heap()->ToBoolean( ComparisonResultToBool(Operation::kGreaterThanOrEqual, result)); } RUNTIME_FUNCTION(Runtime_StringEqual) { HandleScope handle_scope(isolate); DCHECK_EQ(2, args.length()); // This function can be called from Wasm: optimized Wasm code calls // straight to the "StringEqual" builtin, which tail-calls here. So on // the stack, the CEntryStub's EXIT frame will sit right on top of the // Wasm frame; and Wasm frames don't scan their outgoing parameters (in // order to support tail-calls between Wasm functions), while the EXIT // frame doesn't scan its incoming parameters (because it expects to be // called from JS). // Working around this by calling through a trampoline builtin is slow. // Teaching the stack walker to be smarter has proven to be difficult. // In the future, Conservative Stack Scanning will trivially solve the // problem. In the meantime, we can work around it by explicitly creating // handles here (rather than treating the on-stack arguments as handles). // // TODO(42203211): Don't create new handles here once direct handles and CSS // are enabled by default. DirectHandle<String> x(*args.at<String>(0), isolate); DirectHandle<String> y(*args.at<String>(1), isolate); return isolate->heap()->ToBoolean(String::Equals(isolate, x, y)); } RUNTIME_FUNCTION(Runtime_StringCompare) { DCHECK_EQ(2, args.length()); HandleScope scope(isolate); DirectHandle<String> lhs(Cast<String>(args[0]), isolate); DirectHandle<String> rhs(Cast<String>(args[1]), isolate); ComparisonResult result = String::Compare(isolate, lhs, rhs); DCHECK_NE(result, ComparisonResult::kUndefined); return Smi::FromInt(static_cast<int>(result)); } RUNTIME_FUNCTION(Runtime_FlattenString) { HandleScope scope(isolate); DCHECK_EQ(1, args.length()); DirectHandle<String> str = args.at<String>(0); return *String::Flatten(isolate, str); } RUNTIME_FUNCTION(Runtime_StringMaxLength) { SealHandleScope shs(isolate); return Smi::FromInt(String::kMaxLength); } RUNTIME_FUNCTION(Runtime_StringEscapeQuotes) { HandleScope handle_scope(isolate); DCHECK_EQ(1, args.length()); DirectHandle<String> string = args.at<String>(0); // Equivalent to global replacement `string.replace(/"/g, """)`, but this // does not modify any global state (e.g. the regexp match info). const int string_length = string->length(); DirectHandle<String> quotes = isolate->factory()->LookupSingleCharacterStringFromCode('"'); int quote_index = String::IndexOf(isolate, string, quotes, 0); // No quotes, nothing to do. if (quote_index == -1) return *string; // Find all quotes. std::vector<int> indices = {quote_index}; while (quote_index + 1 < string_length) { quote_index = String::IndexOf(isolate, string, quotes, quote_index + 1); if (quote_index == -1) break; indices.emplace_back(quote_index); } // Build the replacement string. DirectHandle<String> replacement = isolate->factory()->NewStringFromAsciiChecked("""); const int estimated_part_count = static_cast<int>(indices.size()) * 2 + 1; ReplacementStringBuilder builder(isolate->heap(), string, estimated_part_count); int prev_index = -1; // Start at -1 to avoid special-casing the first match. for (int index : indices) { const int slice_start = prev_index + 1; const int slice_end = index; if (slice_end > slice_start) { builder.AddSubjectSlice(slice_start, slice_end); } builder.AddString(replacement); prev_index = index; } if (prev_index < string_length - 1) { builder.AddSubjectSlice(prev_index + 1, string_length); } DirectHandle<String> result; ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, builder.ToString()); return *result; } RUNTIME_FUNCTION(Runtime_StringIsWellFormed) { HandleScope handle_scope(isolate); DCHECK_EQ(1, args.length()); DirectHandle<String> string = args.at<String>(0); return isolate->heap()->ToBoolean( String::IsWellFormedUnicode(isolate, string)); } RUNTIME_FUNCTION(Runtime_StringToWellFormed) { HandleScope handle_scope(isolate); DCHECK_EQ(1, args.length()); DirectHandle<String> source = args.at<String>(0); if (String::IsWellFormedUnicode(isolate, source)) return *source; // String::IsWellFormedUnicode would have returned true above otherwise. DCHECK(!String::IsOneByteRepresentationUnderneath(*source)); const int length = source->length(); DirectHandle<SeqTwoByteString> dest = isolate->factory()->NewRawTwoByteString(length).ToHandleChecked(); DisallowGarbageCollection no_gc; String::FlatContent source_contents = source->GetFlatContent(no_gc); DCHECK(source_contents.IsFlat()); const uint16_t* source_data = source_contents.ToUC16Vector().begin(); uint16_t* dest_data = dest->GetChars(no_gc); unibrow::Utf16::ReplaceUnpairedSurrogates(source_data, dest_data, length); return *dest; } } // namespace internal } // namespace v8