in runtime/vm/regexp_interpreter.cc [179:685]
static ObjectPtr RawMatch(const TypedData& bytecode,
const String& subject,
int32_t* registers,
intptr_t current,
uint32_t current_char) {
// BacktrackStack ensures that the memory allocated for the backtracking stack
// is returned to the system or cached if there is no stack being cached at
// the moment.
BacktrackStack backtrack_stack;
if (backtrack_stack.out_of_memory()) {
Exceptions::ThrowOOM();
UNREACHABLE();
}
intptr_t* backtrack_stack_base = backtrack_stack.data();
intptr_t* backtrack_sp = backtrack_stack_base;
intptr_t backtrack_stack_space = backtrack_stack.max_size();
// TODO(zerny): Optimize as single instance. V8 has this as an
// isolate member.
unibrow::Mapping<unibrow::Ecma262Canonicalize> canonicalize;
intptr_t subject_length = subject.Length();
#ifdef DEBUG
if (FLAG_trace_regexp_bytecodes) {
OS::PrintErr("Start irregexp bytecode interpreter\n");
}
#endif
const auto thread = Thread::Current();
const uint8_t* code_base;
const uint8_t* pc;
{
NoSafepointScope no_safepoint;
code_base = reinterpret_cast<uint8_t*>(bytecode.DataAddr(0));
pc = code_base;
}
while (true) {
if (UNLIKELY(thread->HasScheduledInterrupts())) {
intptr_t pc_offset = pc - code_base;
ErrorPtr error = thread->HandleInterrupts();
if (error != Object::null()) {
// Needs to be propagated to the Dart native invoking the
// regex matcher.
return error;
}
NoSafepointScope no_safepoint;
code_base = reinterpret_cast<uint8_t*>(bytecode.DataAddr(0));
pc = code_base + pc_offset;
}
NoSafepointScope no_safepoint;
bool check_for_safepoint_now = false;
while (!check_for_safepoint_now) {
int32_t insn = Load32Aligned(pc);
switch (insn & BYTECODE_MASK) {
BYTECODE(BREAK)
UNREACHABLE();
return Bool::False().ptr();
BYTECODE(PUSH_CP)
if (--backtrack_stack_space < 0) {
return Object::null();
}
*backtrack_sp++ = current;
pc += BC_PUSH_CP_LENGTH;
break;
BYTECODE(PUSH_BT)
if (--backtrack_stack_space < 0) {
return Object::null();
}
*backtrack_sp++ = Load32Aligned(pc + 4);
pc += BC_PUSH_BT_LENGTH;
break;
BYTECODE(PUSH_REGISTER)
if (--backtrack_stack_space < 0) {
return Object::null();
}
*backtrack_sp++ = registers[insn >> BYTECODE_SHIFT];
pc += BC_PUSH_REGISTER_LENGTH;
break;
BYTECODE(SET_REGISTER)
registers[insn >> BYTECODE_SHIFT] = Load32Aligned(pc + 4);
pc += BC_SET_REGISTER_LENGTH;
break;
BYTECODE(ADVANCE_REGISTER)
registers[insn >> BYTECODE_SHIFT] += Load32Aligned(pc + 4);
pc += BC_ADVANCE_REGISTER_LENGTH;
break;
BYTECODE(SET_REGISTER_TO_CP)
registers[insn >> BYTECODE_SHIFT] = current + Load32Aligned(pc + 4);
pc += BC_SET_REGISTER_TO_CP_LENGTH;
break;
BYTECODE(SET_CP_TO_REGISTER)
current = registers[insn >> BYTECODE_SHIFT];
pc += BC_SET_CP_TO_REGISTER_LENGTH;
break;
BYTECODE(SET_REGISTER_TO_SP)
registers[insn >> BYTECODE_SHIFT] =
static_cast<int>(backtrack_sp - backtrack_stack_base);
pc += BC_SET_REGISTER_TO_SP_LENGTH;
break;
BYTECODE(SET_SP_TO_REGISTER)
backtrack_sp = backtrack_stack_base + registers[insn >> BYTECODE_SHIFT];
backtrack_stack_space =
backtrack_stack.max_size() -
static_cast<int>(backtrack_sp - backtrack_stack_base);
pc += BC_SET_SP_TO_REGISTER_LENGTH;
break;
BYTECODE(POP_CP)
backtrack_stack_space++;
--backtrack_sp;
current = *backtrack_sp;
pc += BC_POP_CP_LENGTH;
break;
BYTECODE(POP_BT)
backtrack_stack_space++;
--backtrack_sp;
pc = code_base + *backtrack_sp;
// This should match check cadence in JIT irregexp implementation.
check_for_safepoint_now = true;
break;
BYTECODE(POP_REGISTER)
backtrack_stack_space++;
--backtrack_sp;
registers[insn >> BYTECODE_SHIFT] = *backtrack_sp;
pc += BC_POP_REGISTER_LENGTH;
break;
BYTECODE(FAIL)
return Bool::False().ptr();
BYTECODE(SUCCEED)
return Bool::True().ptr();
BYTECODE(ADVANCE_CP)
current += insn >> BYTECODE_SHIFT;
pc += BC_ADVANCE_CP_LENGTH;
break;
BYTECODE(GOTO)
pc = code_base + Load32Aligned(pc + 4);
break;
BYTECODE(ADVANCE_CP_AND_GOTO)
current += insn >> BYTECODE_SHIFT;
pc = code_base + Load32Aligned(pc + 4);
break;
BYTECODE(CHECK_GREEDY)
if (current == backtrack_sp[-1]) {
backtrack_sp--;
backtrack_stack_space++;
pc = code_base + Load32Aligned(pc + 4);
} else {
pc += BC_CHECK_GREEDY_LENGTH;
}
break;
BYTECODE(LOAD_CURRENT_CHAR) {
int pos = current + (insn >> BYTECODE_SHIFT);
if (pos < 0 || pos >= subject_length) {
pc = code_base + Load32Aligned(pc + 4);
} else {
current_char = subject.CharAt(pos);
pc += BC_LOAD_CURRENT_CHAR_LENGTH;
}
break;
}
BYTECODE(LOAD_CURRENT_CHAR_UNCHECKED) {
int pos = current + (insn >> BYTECODE_SHIFT);
current_char = subject.CharAt(pos);
pc += BC_LOAD_CURRENT_CHAR_UNCHECKED_LENGTH;
break;
}
BYTECODE(LOAD_2_CURRENT_CHARS) {
int pos = current + (insn >> BYTECODE_SHIFT);
if (pos + 2 > subject_length) {
pc = code_base + Load32Aligned(pc + 4);
} else {
Char next = subject.CharAt(pos + 1);
current_char =
subject.CharAt(pos) | (next << (kBitsPerByte * sizeof(Char)));
pc += BC_LOAD_2_CURRENT_CHARS_LENGTH;
}
break;
}
BYTECODE(LOAD_2_CURRENT_CHARS_UNCHECKED) {
int pos = current + (insn >> BYTECODE_SHIFT);
Char next = subject.CharAt(pos + 1);
current_char =
subject.CharAt(pos) | (next << (kBitsPerByte * sizeof(Char)));
pc += BC_LOAD_2_CURRENT_CHARS_UNCHECKED_LENGTH;
break;
}
BYTECODE(LOAD_4_CURRENT_CHARS) {
ASSERT(sizeof(Char) == 1);
int pos = current + (insn >> BYTECODE_SHIFT);
if (pos + 4 > subject_length) {
pc = code_base + Load32Aligned(pc + 4);
} else {
Char next1 = subject.CharAt(pos + 1);
Char next2 = subject.CharAt(pos + 2);
Char next3 = subject.CharAt(pos + 3);
current_char = (subject.CharAt(pos) | (next1 << 8) | (next2 << 16) |
(next3 << 24));
pc += BC_LOAD_4_CURRENT_CHARS_LENGTH;
}
break;
}
BYTECODE(LOAD_4_CURRENT_CHARS_UNCHECKED) {
ASSERT(sizeof(Char) == 1);
int pos = current + (insn >> BYTECODE_SHIFT);
Char next1 = subject.CharAt(pos + 1);
Char next2 = subject.CharAt(pos + 2);
Char next3 = subject.CharAt(pos + 3);
current_char = (subject.CharAt(pos) | (next1 << 8) | (next2 << 16) |
(next3 << 24));
pc += BC_LOAD_4_CURRENT_CHARS_UNCHECKED_LENGTH;
break;
}
BYTECODE(CHECK_4_CHARS) {
uint32_t c = Load32Aligned(pc + 4);
if (c == current_char) {
pc = code_base + Load32Aligned(pc + 8);
} else {
pc += BC_CHECK_4_CHARS_LENGTH;
}
break;
}
BYTECODE(CHECK_CHAR) {
uint32_t c = (insn >> BYTECODE_SHIFT);
if (c == current_char) {
pc = code_base + Load32Aligned(pc + 4);
} else {
pc += BC_CHECK_CHAR_LENGTH;
}
break;
}
BYTECODE(CHECK_NOT_4_CHARS) {
uint32_t c = Load32Aligned(pc + 4);
if (c != current_char) {
pc = code_base + Load32Aligned(pc + 8);
} else {
pc += BC_CHECK_NOT_4_CHARS_LENGTH;
}
break;
}
BYTECODE(CHECK_NOT_CHAR) {
uint32_t c = (insn >> BYTECODE_SHIFT);
if (c != current_char) {
pc = code_base + Load32Aligned(pc + 4);
} else {
pc += BC_CHECK_NOT_CHAR_LENGTH;
}
break;
}
BYTECODE(AND_CHECK_4_CHARS) {
uint32_t c = Load32Aligned(pc + 4);
if (c == (current_char & Load32Aligned(pc + 8))) {
pc = code_base + Load32Aligned(pc + 12);
} else {
pc += BC_AND_CHECK_4_CHARS_LENGTH;
}
break;
}
BYTECODE(AND_CHECK_CHAR) {
uint32_t c = (insn >> BYTECODE_SHIFT);
if (c == (current_char & Load32Aligned(pc + 4))) {
pc = code_base + Load32Aligned(pc + 8);
} else {
pc += BC_AND_CHECK_CHAR_LENGTH;
}
break;
}
BYTECODE(AND_CHECK_NOT_4_CHARS) {
uint32_t c = Load32Aligned(pc + 4);
if (c != (current_char & Load32Aligned(pc + 8))) {
pc = code_base + Load32Aligned(pc + 12);
} else {
pc += BC_AND_CHECK_NOT_4_CHARS_LENGTH;
}
break;
}
BYTECODE(AND_CHECK_NOT_CHAR) {
uint32_t c = (insn >> BYTECODE_SHIFT);
if (c != (current_char & Load32Aligned(pc + 4))) {
pc = code_base + Load32Aligned(pc + 8);
} else {
pc += BC_AND_CHECK_NOT_CHAR_LENGTH;
}
break;
}
BYTECODE(MINUS_AND_CHECK_NOT_CHAR) {
uint32_t c = (insn >> BYTECODE_SHIFT);
uint32_t minus = Load16Aligned(pc + 4);
uint32_t mask = Load16Aligned(pc + 6);
if (c != ((current_char - minus) & mask)) {
pc = code_base + Load32Aligned(pc + 8);
} else {
pc += BC_MINUS_AND_CHECK_NOT_CHAR_LENGTH;
}
break;
}
BYTECODE(CHECK_CHAR_IN_RANGE) {
uint32_t from = Load16Aligned(pc + 4);
uint32_t to = Load16Aligned(pc + 6);
if (from <= current_char && current_char <= to) {
pc = code_base + Load32Aligned(pc + 8);
} else {
pc += BC_CHECK_CHAR_IN_RANGE_LENGTH;
}
break;
}
BYTECODE(CHECK_CHAR_NOT_IN_RANGE) {
uint32_t from = Load16Aligned(pc + 4);
uint32_t to = Load16Aligned(pc + 6);
if (from > current_char || current_char > to) {
pc = code_base + Load32Aligned(pc + 8);
} else {
pc += BC_CHECK_CHAR_NOT_IN_RANGE_LENGTH;
}
break;
}
BYTECODE(CHECK_BIT_IN_TABLE) {
int mask = RegExpMacroAssembler::kTableMask;
uint8_t b = pc[8 + ((current_char & mask) >> kBitsPerByteLog2)];
int bit = (current_char & (kBitsPerByte - 1));
if ((b & (1 << bit)) != 0) {
pc = code_base + Load32Aligned(pc + 4);
} else {
pc += BC_CHECK_BIT_IN_TABLE_LENGTH;
}
break;
}
BYTECODE(CHECK_LT) {
uint32_t limit = (insn >> BYTECODE_SHIFT);
if (current_char < limit) {
pc = code_base + Load32Aligned(pc + 4);
} else {
pc += BC_CHECK_LT_LENGTH;
}
break;
}
BYTECODE(CHECK_GT) {
uint32_t limit = (insn >> BYTECODE_SHIFT);
if (current_char > limit) {
pc = code_base + Load32Aligned(pc + 4);
} else {
pc += BC_CHECK_GT_LENGTH;
}
break;
}
BYTECODE(CHECK_REGISTER_LT)
if (registers[insn >> BYTECODE_SHIFT] < Load32Aligned(pc + 4)) {
pc = code_base + Load32Aligned(pc + 8);
} else {
pc += BC_CHECK_REGISTER_LT_LENGTH;
}
break;
BYTECODE(CHECK_REGISTER_GE)
if (registers[insn >> BYTECODE_SHIFT] >= Load32Aligned(pc + 4)) {
pc = code_base + Load32Aligned(pc + 8);
} else {
pc += BC_CHECK_REGISTER_GE_LENGTH;
}
break;
BYTECODE(CHECK_REGISTER_EQ_POS)
if (registers[insn >> BYTECODE_SHIFT] == current) {
pc = code_base + Load32Aligned(pc + 4);
} else {
pc += BC_CHECK_REGISTER_EQ_POS_LENGTH;
}
break;
BYTECODE(CHECK_NOT_REGS_EQUAL)
if (registers[insn >> BYTECODE_SHIFT] ==
registers[Load32Aligned(pc + 4)]) {
pc += BC_CHECK_NOT_REGS_EQUAL_LENGTH;
} else {
pc = code_base + Load32Aligned(pc + 8);
}
break;
BYTECODE(CHECK_NOT_BACK_REF) {
int from = registers[insn >> BYTECODE_SHIFT];
int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
if (from < 0 || len <= 0) {
pc += BC_CHECK_NOT_BACK_REF_LENGTH;
break;
}
if (current + len > subject_length) {
pc = code_base + Load32Aligned(pc + 4);
break;
} else {
int i;
for (i = 0; i < len; i++) {
if (subject.CharAt(from + i) != subject.CharAt(current + i)) {
pc = code_base + Load32Aligned(pc + 4);
break;
}
}
if (i < len) break;
current += len;
}
pc += BC_CHECK_NOT_BACK_REF_LENGTH;
break;
}
BYTECODE(CHECK_NOT_BACK_REF_NO_CASE_UNICODE)
FALL_THROUGH;
BYTECODE(CHECK_NOT_BACK_REF_NO_CASE) {
const bool unicode =
(insn & BYTECODE_MASK) == BC_CHECK_NOT_BACK_REF_NO_CASE_UNICODE;
int from = registers[insn >> BYTECODE_SHIFT];
int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
if (from < 0 || len <= 0) {
pc += BC_CHECK_NOT_BACK_REF_NO_CASE_LENGTH;
break;
}
if (current + len > subject_length) {
pc = code_base + Load32Aligned(pc + 4);
break;
} else {
if (BackRefMatchesNoCase<Char>(&canonicalize, from, current, len,
subject, unicode)) {
current += len;
pc += BC_CHECK_NOT_BACK_REF_NO_CASE_LENGTH;
} else {
pc = code_base + Load32Aligned(pc + 4);
}
}
break;
}
BYTECODE(CHECK_NOT_BACK_REF_BACKWARD) {
const int from = registers[insn >> BYTECODE_SHIFT];
const int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
if (from < 0 || len <= 0) {
pc += BC_CHECK_NOT_BACK_REF_BACKWARD_LENGTH;
break;
}
if ((current - len) < 0) {
pc = code_base + Load32Aligned(pc + 4);
break;
} else {
// When looking behind, the string to match (if it is there) lies
// before the current position, so we will check the [len]
// characters before the current position, excluding the current
// position itself.
const int start = current - len;
int i;
for (i = 0; i < len; i++) {
if (subject.CharAt(from + i) != subject.CharAt(start + i)) {
pc = code_base + Load32Aligned(pc + 4);
break;
}
}
if (i < len) break;
current -= len;
}
pc += BC_CHECK_NOT_BACK_REF_BACKWARD_LENGTH;
break;
}
BYTECODE(CHECK_NOT_BACK_REF_NO_CASE_UNICODE_BACKWARD)
FALL_THROUGH;
BYTECODE(CHECK_NOT_BACK_REF_NO_CASE_BACKWARD) {
bool unicode = (insn & BYTECODE_MASK) ==
BC_CHECK_NOT_BACK_REF_NO_CASE_UNICODE_BACKWARD;
int from = registers[insn >> BYTECODE_SHIFT];
int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
if (from < 0 || len <= 0) {
pc += BC_CHECK_NOT_BACK_REF_NO_CASE_BACKWARD_LENGTH;
break;
}
if (current < len) {
pc = code_base + Load32Aligned(pc + 4);
break;
} else {
if (BackRefMatchesNoCase<Char>(&canonicalize, from, current - len,
len, subject, unicode)) {
current -= len;
pc += BC_CHECK_NOT_BACK_REF_NO_CASE_BACKWARD_LENGTH;
} else {
pc = code_base + Load32Aligned(pc + 4);
}
}
break;
}
BYTECODE(CHECK_AT_START)
if (current == 0) {
pc = code_base + Load32Aligned(pc + 4);
} else {
pc += BC_CHECK_AT_START_LENGTH;
}
break;
BYTECODE(CHECK_NOT_AT_START) {
const int32_t cp_offset = insn >> BYTECODE_SHIFT;
if (current + cp_offset == 0) {
pc += BC_CHECK_NOT_AT_START_LENGTH;
} else {
pc = code_base + Load32Aligned(pc + 4);
}
break;
}
BYTECODE(SET_CURRENT_POSITION_FROM_END) {
int by = static_cast<uint32_t>(insn) >> BYTECODE_SHIFT;
if (subject_length - current > by) {
current = subject_length - by;
current_char = subject.CharAt(current - 1);
}
pc += BC_SET_CURRENT_POSITION_FROM_END_LENGTH;
break;
}
default:
UNREACHABLE();
break;
}
}
}
}