// 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/logging/counters.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/regexp/regexp-utils.h" #include "src/runtime/runtime-utils.h" #include "src/strings/string-builder-inl.h" #include "src/strings/string-search.h" namespace v8 { namespace internal { RUNTIME_FUNCTION(Runtime_GetSubstitution) { HandleScope scope(isolate); DCHECK_EQ(5, args.length()); CONVERT_ARG_HANDLE_CHECKED(String, matched, 0); CONVERT_ARG_HANDLE_CHECKED(String, subject, 1); CONVERT_SMI_ARG_CHECKED(position, 2); CONVERT_ARG_HANDLE_CHECKED(String, replacement, 3); CONVERT_SMI_ARG_CHECKED(start_index, 4); // A simple match without captures. class SimpleMatch : public String::Match { public: SimpleMatch(Handle<String> match, Handle<String> prefix, Handle<String> suffix) : match_(match), prefix_(prefix), suffix_(suffix) {} Handle<String> GetMatch() override { return match_; } Handle<String> GetPrefix() override { return prefix_; } Handle<String> GetSuffix() override { return suffix_; } int CaptureCount() override { return 0; } bool HasNamedCaptures() override { return false; } MaybeHandle<String> GetCapture(int i, bool* capture_exists) override { *capture_exists = false; return match_; // Return arbitrary string handle. } MaybeHandle<String> GetNamedCapture(Handle<String> name, CaptureState* state) override { UNREACHABLE(); } private: Handle<String> match_, prefix_, suffix_; }; Handle<String> prefix = isolate->factory()->NewSubString(subject, 0, position); Handle<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 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(cons.first(), isolate); Handle<String> second = handle(cons.second(), isolate); 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_EQ(3, args.length()); 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 ReadOnlyRoots(isolate).exception(); subject = String::Flatten(isolate, subject); if (StringReplaceOneCharWithString(isolate, subject, search, replace, &found, kRecursionLimit).ToHandle(&result)) { return *result; } if (isolate->has_pending_exception()) return ReadOnlyRoots(isolate).exception(); // In case of empty handle and no pending 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()); CONVERT_ARG_HANDLE_CHECKED(String, string, 0); CONVERT_INT32_ARG_CHECKED(start, 1); CONVERT_INT32_ARG_CHECKED(end, 2); DCHECK_LE(0, start); DCHECK_LE(start, end); DCHECK_LE(end, string->length()); isolate->counters()->sub_string_runtime()->Increment(); return *isolate->factory()->NewSubString(string, start, end); } RUNTIME_FUNCTION(Runtime_StringAdd) { HandleScope scope(isolate); DCHECK_EQ(2, args.length()); CONVERT_ARG_HANDLE_CHECKED(String, str1, 0); CONVERT_ARG_HANDLE_CHECKED(String, str2, 1); isolate->counters()->string_add_runtime()->Increment(); RETURN_RESULT_OR_FAILURE(isolate, isolate->factory()->NewConsString(str1, str2)); } RUNTIME_FUNCTION(Runtime_InternalizeString) { HandleScope handles(isolate); DCHECK_EQ(1, args.length()); CONVERT_ARG_HANDLE_CHECKED(String, string, 0); return *isolate->factory()->InternalizeString(string); } RUNTIME_FUNCTION(Runtime_StringCharCodeAt) { HandleScope handle_scope(isolate); DCHECK_EQ(2, args.length()); 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(isolate, subject); if (i >= static_cast<uint32_t>(subject->length())) { return ReadOnlyRoots(isolate).nan_value(); } return Smi::FromInt(subject->Get(i)); } RUNTIME_FUNCTION(Runtime_StringBuilderConcat) { HandleScope scope(isolate); DCHECK_EQ(3, args.length()); 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_GE(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_GE(Smi::kMaxValue, String::kMaxLength); CHECK(array->HasFastElements()); JSObject::EnsureCanContainHeapObjectElements(array); int special_length = special->length(); if (!array->HasObjectElements()) { return isolate->Throw(ReadOnlyRoots(isolate).illegal_argument_string()); } int length; bool one_byte = special->IsOneByteRepresentation(); { DisallowGarbageCollection 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 ReadOnlyRoots(isolate).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(ReadOnlyRoots(isolate).illegal_argument_string()); } if (length == 0) { return ReadOnlyRoots(isolate).empty_string(); } if (one_byte) { Handle<SeqOneByteString> answer; ASSIGN_RETURN_FAILURE_ON_EXCEPTION( isolate, answer, isolate->factory()->NewRawOneByteString(length)); DisallowGarbageCollection no_gc; StringBuilderConcatHelper(*special, answer->GetChars(no_gc), FixedArray::cast(array->elements()), array_length); return *answer; } else { Handle<SeqTwoByteString> answer; ASSIGN_RETURN_FAILURE_ON_EXCEPTION( isolate, answer, isolate->factory()->NewRawTwoByteString(length)); DisallowGarbageCollection no_gc; StringBuilderConcatHelper(*special, answer->GetChars(no_gc), FixedArray::cast(array->elements()), array_length); return *answer; } } // 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) { DisallowGarbageCollection no_gc; FixedArray one_byte_cache = heap->single_character_string_cache(); Object undefined = ReadOnlyRoots(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) { MemsetTagged(elements.RawFieldOfElementAt(i), Smi::zero(), length - i); } #ifdef DEBUG for (int j = 0; j < length; ++j) { Object element = elements.get(j); DCHECK(element == Smi::zero() || (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_EQ(2, args.length()); CONVERT_ARG_HANDLE_CHECKED(String, s, 0); CONVERT_NUMBER_CHECKED(uint32_t, limit, Uint32, args[1]); s = String::Flatten(isolate, s); const int length = static_cast<int>(std::min(static_cast<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()->NewFixedArray(length); DisallowGarbageCollection no_gc; String::FlatContent content = s->GetFlatContent(no_gc); 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.begin(), *elements, length); } else { MemsetTagged(elements->data_start(), ReadOnlyRoots(isolate).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_EQ(String::cast(elements->get(i)).length(), 1); } #endif return *isolate->factory()->NewJSArrayWithElements(elements); } 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); 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()); CONVERT_ARG_HANDLE_CHECKED(String, x, 0); CONVERT_ARG_HANDLE_CHECKED(String, y, 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()); CONVERT_ARG_HANDLE_CHECKED(String, x, 0); CONVERT_ARG_HANDLE_CHECKED(String, y, 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()); CONVERT_ARG_HANDLE_CHECKED(String, x, 0); CONVERT_ARG_HANDLE_CHECKED(String, y, 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()); CONVERT_ARG_HANDLE_CHECKED(String, x, 0); CONVERT_ARG_HANDLE_CHECKED(String, y, 1); return isolate->heap()->ToBoolean(String::Equals(isolate, x, y)); } RUNTIME_FUNCTION(Runtime_FlattenString) { HandleScope scope(isolate); DCHECK_EQ(1, args.length()); CONVERT_ARG_HANDLE_CHECKED(String, str, 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()); CONVERT_ARG_HANDLE_CHECKED(String, 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(); Handle<String> quotes = isolate->factory()->LookupSingleCharacterStringFromCode('"'); int index = String::IndexOf(isolate, string, quotes, 0); // No quotes, nothing to do. if (index == -1) return *string; // Find all quotes. std::vector<int> indices = {index}; while (index + 1 < string_length) { index = String::IndexOf(isolate, string, quotes, index + 1); if (index == -1) break; indices.emplace_back(index); } // Build the replacement string. Handle<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); } return *builder.ToString().ToHandleChecked(); } } // namespace internal } // namespace v8