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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/arguments-inl.h"
#include "src/conversions.h"
#include "src/counters.h"
#include "src/heap/heap-inl.h"
#include "src/objects-inl.h"
#include "src/objects/js-array-inl.h"
#include "src/objects/slots.h"
#include "src/objects/smi.h"
#include "src/regexp/jsregexp-inl.h"
#include "src/regexp/regexp-utils.h"
#include "src/runtime/runtime-utils.h"
#include "src/string-builder-inl.h"
#include "src/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_StringTrim) {
HandleScope scope(isolate);
DCHECK_EQ(2, args.length());
Handle<String> string = args.at<String>(0);
CONVERT_SMI_ARG_CHECKED(mode, 1);
String::TrimMode trim_mode = static_cast<String::TrimMode>(mode);
return *String::Trim(isolate, string, trim_mode);
}
// ES6 #sec-string.prototype.includes
// String.prototype.includes(searchString [, position])
RUNTIME_FUNCTION(Runtime_StringIncludes) {
HandleScope scope(isolate);
DCHECK_EQ(3, args.length());
Handle<Object> receiver = args.at(0);
if (receiver->IsNullOrUndefined(isolate)) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kCalledOnNullOrUndefined,
isolate->factory()->NewStringFromAsciiChecked(
"String.prototype.includes")));
}
Handle<String> receiver_string;
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, receiver_string,
Object::ToString(isolate, receiver));
// Check if the search string is a regExp and fail if it is.
Handle<Object> search = args.at(1);
Maybe<bool> is_reg_exp = RegExpUtils::IsRegExp(isolate, search);
if (is_reg_exp.IsNothing()) {
DCHECK(isolate->has_pending_exception());
return ReadOnlyRoots(isolate).exception();
}
if (is_reg_exp.FromJust()) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kFirstArgumentNotRegExp,
isolate->factory()->NewStringFromStaticChars(
"String.prototype.includes")));
}
Handle<String> search_string;
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, search_string,
Object::ToString(isolate, args.at(1)));
Handle<Object> position;
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, position,
Object::ToInteger(isolate, args.at(2)));
uint32_t index = receiver_string->ToValidIndex(*position);
int index_in_str =
String::IndexOf(isolate, receiver_string, search_string, index);
return *isolate->factory()->ToBoolean(index_in_str != -1);
}
// ES6 #sec-string.prototype.indexof
// String.prototype.indexOf(searchString [, position])
RUNTIME_FUNCTION(Runtime_StringIndexOf) {
HandleScope scope(isolate);
DCHECK_EQ(3, args.length());
return String::IndexOf(isolate, args.at(0), args.at(1), args.at(2));
}
// ES6 #sec-string.prototype.indexof
// String.prototype.indexOf(searchString, position)
// Fast version that assumes that does not perform conversions of the incoming
// arguments.
RUNTIME_FUNCTION(Runtime_StringIndexOfUnchecked) {
HandleScope scope(isolate);
DCHECK_EQ(3, args.length());
Handle<String> receiver_string = args.at<String>(0);
Handle<String> search_string = args.at<String>(1);
int index = std::min(std::max(args.smi_at(2), 0), receiver_string->length());
return Smi::FromInt(String::IndexOf(isolate, receiver_string, search_string,
static_cast<uint32_t>(index)));
}
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();
{
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 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));
DisallowHeapAllocation 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));
DisallowHeapAllocation 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) {
DisallowHeapAllocation 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::kZero, 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_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>(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(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.start(),
*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_StringCompareSequence) {
HandleScope handle_scope(isolate);
DCHECK_EQ(3, args.length());
CONVERT_ARG_HANDLE_CHECKED(String, string, 0);
CONVERT_ARG_HANDLE_CHECKED(String, search_string, 1);
CONVERT_NUMBER_CHECKED(int, start, Int32, args[2]);
// Check if start + searchLength is in bounds.
DCHECK_LE(start + search_string->length(), string->length());
FlatStringReader string_reader(isolate, String::Flatten(isolate, string));
FlatStringReader search_reader(isolate,
String::Flatten(isolate, search_string));
for (int i = 0; i < search_string->length(); i++) {
if (string_reader.Get(start + i) != search_reader.Get(i)) {
return ReadOnlyRoots(isolate).false_value();
}
}
return ReadOnlyRoots(isolate).true_value();
}
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, "&quot")`, 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("&quot;");
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