Server : Apache/2.4.6 (CentOS) OpenSSL/1.0.2k-fips PHP/7.4.20 System : Linux st2.domain.com 3.10.0-1127.10.1.el7.x86_64 #1 SMP Wed Jun 3 14:28:03 UTC 2020 x86_64 User : apache ( 48) PHP Version : 7.4.20 Disable Function : NONE Directory : /home/real/node-v13.0.1/deps/v8/src/ast/ |
// Copyright 2014 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "src/ast/ast-value-factory.h"
#include "src/objects/objects-inl.h"
#include "src/objects/objects.h"
#include "src/strings/char-predicates-inl.h"
#include "src/strings/string-hasher.h"
#include "src/utils/utils-inl.h"
namespace v8 {
namespace internal {
namespace {
// For using StringToArrayIndex.
class OneByteStringStream {
public:
explicit OneByteStringStream(Vector<const byte> lb) :
literal_bytes_(lb), pos_(0) {}
bool HasMore() { return pos_ < literal_bytes_.length(); }
uint16_t GetNext() { return literal_bytes_[pos_++]; }
private:
Vector<const byte> literal_bytes_;
int pos_;
};
} // namespace
void AstRawString::Internalize(Isolate* isolate) {
DCHECK(!has_string_);
if (literal_bytes_.length() == 0) {
set_string(isolate->factory()->empty_string());
} else if (is_one_byte()) {
OneByteStringKey key(hash_field_, literal_bytes_);
set_string(StringTable::LookupKey(isolate, &key));
} else {
TwoByteStringKey key(hash_field_,
Vector<const uint16_t>::cast(literal_bytes_));
set_string(StringTable::LookupKey(isolate, &key));
}
}
bool AstRawString::AsArrayIndex(uint32_t* index) const {
// The StringHasher will set up the hash in such a way that we can use it to
// figure out whether the string is convertible to an array index.
if ((hash_field_ & Name::kIsNotArrayIndexMask) != 0) return false;
if (length() <= Name::kMaxCachedArrayIndexLength) {
*index = Name::ArrayIndexValueBits::decode(hash_field_);
} else {
OneByteStringStream stream(literal_bytes_);
CHECK(StringToArrayIndex(&stream, index));
}
return true;
}
bool AstRawString::IsOneByteEqualTo(const char* data) const {
if (!is_one_byte()) return false;
size_t length = static_cast<size_t>(literal_bytes_.length());
if (length != strlen(data)) return false;
return 0 == strncmp(reinterpret_cast<const char*>(literal_bytes_.begin()),
data, length);
}
uint16_t AstRawString::FirstCharacter() const {
if (is_one_byte()) return literal_bytes_[0];
const uint16_t* c = reinterpret_cast<const uint16_t*>(literal_bytes_.begin());
return *c;
}
bool AstRawString::Compare(void* a, void* b) {
const AstRawString* lhs = static_cast<AstRawString*>(a);
const AstRawString* rhs = static_cast<AstRawString*>(b);
DCHECK_EQ(lhs->Hash(), rhs->Hash());
if (lhs->length() != rhs->length()) return false;
if (lhs->length() == 0) return true;
const unsigned char* l = lhs->raw_data();
const unsigned char* r = rhs->raw_data();
size_t length = rhs->length();
if (lhs->is_one_byte()) {
if (rhs->is_one_byte()) {
return CompareCharsUnsigned(reinterpret_cast<const uint8_t*>(l),
reinterpret_cast<const uint8_t*>(r),
length) == 0;
} else {
return CompareCharsUnsigned(reinterpret_cast<const uint8_t*>(l),
reinterpret_cast<const uint16_t*>(r),
length) == 0;
}
} else {
if (rhs->is_one_byte()) {
return CompareCharsUnsigned(reinterpret_cast<const uint16_t*>(l),
reinterpret_cast<const uint8_t*>(r),
length) == 0;
} else {
return CompareCharsUnsigned(reinterpret_cast<const uint16_t*>(l),
reinterpret_cast<const uint16_t*>(r),
length) == 0;
}
}
}
void AstConsString::Internalize(Isolate* isolate) {
if (IsEmpty()) {
set_string(isolate->factory()->empty_string());
return;
}
// AstRawStrings are internalized before AstConsStrings, so
// AstRawString::string() will just work.
Handle<String> tmp(segment_.string->string());
for (AstConsString::Segment* current = segment_.next; current != nullptr;
current = current->next) {
tmp = isolate->factory()
->NewConsString(current->string->string(), tmp)
.ToHandleChecked();
}
set_string(tmp);
}
std::forward_list<const AstRawString*> AstConsString::ToRawStrings() const {
std::forward_list<const AstRawString*> result;
if (IsEmpty()) {
return result;
}
result.emplace_front(segment_.string);
for (AstConsString::Segment* current = segment_.next; current != nullptr;
current = current->next) {
result.emplace_front(current->string);
}
return result;
}
AstStringConstants::AstStringConstants(Isolate* isolate, uint64_t hash_seed)
: zone_(isolate->allocator(), ZONE_NAME),
string_table_(AstRawString::Compare),
hash_seed_(hash_seed) {
DCHECK_EQ(ThreadId::Current(), isolate->thread_id());
#define F(name, str) \
{ \
const char* data = str; \
Vector<const uint8_t> literal(reinterpret_cast<const uint8_t*>(data), \
static_cast<int>(strlen(data))); \
uint32_t hash_field = StringHasher::HashSequentialString<uint8_t>( \
literal.begin(), literal.length(), hash_seed_); \
name##_string_ = new (&zone_) AstRawString(true, literal, hash_field); \
/* The Handle returned by the factory is located on the roots */ \
/* array, not on the temporary HandleScope, so this is safe. */ \
name##_string_->set_string(isolate->factory()->name##_string()); \
base::HashMap::Entry* entry = \
string_table_.InsertNew(name##_string_, name##_string_->Hash()); \
DCHECK_NULL(entry->value); \
entry->value = reinterpret_cast<void*>(1); \
}
AST_STRING_CONSTANTS(F)
#undef F
}
AstRawString* AstValueFactory::GetOneByteStringInternal(
Vector<const uint8_t> literal) {
if (literal.length() == 1 && literal[0] < kMaxOneCharStringValue) {
int key = literal[0];
if (V8_UNLIKELY(one_character_strings_[key] == nullptr)) {
uint32_t hash_field = StringHasher::HashSequentialString<uint8_t>(
literal.begin(), literal.length(), hash_seed_);
one_character_strings_[key] = GetString(hash_field, true, literal);
}
return one_character_strings_[key];
}
uint32_t hash_field = StringHasher::HashSequentialString<uint8_t>(
literal.begin(), literal.length(), hash_seed_);
return GetString(hash_field, true, literal);
}
AstRawString* AstValueFactory::GetTwoByteStringInternal(
Vector<const uint16_t> literal) {
uint32_t hash_field = StringHasher::HashSequentialString<uint16_t>(
literal.begin(), literal.length(), hash_seed_);
return GetString(hash_field, false, Vector<const byte>::cast(literal));
}
const AstRawString* AstValueFactory::GetString(Handle<String> literal) {
AstRawString* result = nullptr;
DisallowHeapAllocation no_gc;
String::FlatContent content = literal->GetFlatContent(no_gc);
if (content.IsOneByte()) {
result = GetOneByteStringInternal(content.ToOneByteVector());
} else {
DCHECK(content.IsTwoByte());
result = GetTwoByteStringInternal(content.ToUC16Vector());
}
return result;
}
const AstRawString* AstValueFactory::CloneFromOtherFactory(
const AstRawString* raw_string) {
const AstRawString* result = GetString(
raw_string->hash_field(), raw_string->is_one_byte(),
Vector<const byte>(raw_string->raw_data(), raw_string->byte_length()));
return result;
}
AstConsString* AstValueFactory::NewConsString() {
AstConsString* new_string = new (zone_) AstConsString;
DCHECK_NOT_NULL(new_string);
AddConsString(new_string);
return new_string;
}
AstConsString* AstValueFactory::NewConsString(const AstRawString* str) {
return NewConsString()->AddString(zone_, str);
}
AstConsString* AstValueFactory::NewConsString(const AstRawString* str1,
const AstRawString* str2) {
return NewConsString()->AddString(zone_, str1)->AddString(zone_, str2);
}
void AstValueFactory::Internalize(Isolate* isolate) {
// Strings need to be internalized before values, because values refer to
// strings.
for (AstRawString* current = strings_; current != nullptr;) {
AstRawString* next = current->next();
current->Internalize(isolate);
current = next;
}
// AstConsStrings refer to AstRawStrings.
for (AstConsString* current = cons_strings_; current != nullptr;) {
AstConsString* next = current->next();
current->Internalize(isolate);
current = next;
}
ResetStrings();
}
AstRawString* AstValueFactory::GetString(uint32_t hash_field, bool is_one_byte,
Vector<const byte> literal_bytes) {
// literal_bytes here points to whatever the user passed, and this is OK
// because we use vector_compare (which checks the contents) to compare
// against the AstRawStrings which are in the string_table_. We should not
// return this AstRawString.
AstRawString key(is_one_byte, literal_bytes, hash_field);
base::HashMap::Entry* entry = string_table_.LookupOrInsert(&key, key.Hash());
if (entry->value == nullptr) {
// Copy literal contents for later comparison.
int length = literal_bytes.length();
byte* new_literal_bytes = zone_->NewArray<byte>(length);
memcpy(new_literal_bytes, literal_bytes.begin(), length);
AstRawString* new_string = new (zone_) AstRawString(
is_one_byte, Vector<const byte>(new_literal_bytes, length), hash_field);
CHECK_NOT_NULL(new_string);
AddString(new_string);
entry->key = new_string;
entry->value = reinterpret_cast<void*>(1);
}
return reinterpret_cast<AstRawString*>(entry->key);
}
} // namespace internal
} // namespace v8