v8/src/regexp-macro-assembler.cc

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// Copyright 2008 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 "v8.h"
#include "ast.h"
#include "assembler.h"
#include "regexp-stack.h"
#include "regexp-macro-assembler.h"
#if V8_TARGET_ARCH_ARM
#include "arm/simulator-arm.h"
#elif V8_TARGET_ARCH_IA32
#include "ia32/simulator-ia32.h"
#elif V8_TARGET_ARCH_X64
#include "x64/simulator-x64.h"
#endif
namespace v8 {
namespace internal {
RegExpMacroAssembler::RegExpMacroAssembler() {
}
RegExpMacroAssembler::~RegExpMacroAssembler() {
}
bool RegExpMacroAssembler::CanReadUnaligned() {
#ifdef V8_HOST_CAN_READ_UNALIGNED
return true;
#else
return false;
#endif
}
#ifdef V8_NATIVE_REGEXP // Avoid unused code, e.g., on ARM.
NativeRegExpMacroAssembler::NativeRegExpMacroAssembler() {
}
NativeRegExpMacroAssembler::~NativeRegExpMacroAssembler() {
}
bool NativeRegExpMacroAssembler::CanReadUnaligned() {
#ifdef V8_TARGET_CAN_READ_UNALIGNED
return true;
#else
return false;
#endif
}
const byte* NativeRegExpMacroAssembler::StringCharacterPosition(
String* subject,
int start_index) {
// Not just flat, but ultra flat.
ASSERT(subject->IsExternalString() || subject->IsSeqString());
ASSERT(start_index >= 0);
ASSERT(start_index <= subject->length());
if (subject->IsAsciiRepresentation()) {
const byte* address;
if (StringShape(subject).IsExternal()) {
const char* data = ExternalAsciiString::cast(subject)->resource()->data();
address = reinterpret_cast<const byte*>(data);
} else {
ASSERT(subject->IsSeqAsciiString());
char* data = SeqAsciiString::cast(subject)->GetChars();
address = reinterpret_cast<const byte*>(data);
}
return address + start_index;
}
const uc16* data;
if (StringShape(subject).IsExternal()) {
data = ExternalTwoByteString::cast(subject)->resource()->data();
} else {
ASSERT(subject->IsSeqTwoByteString());
data = SeqTwoByteString::cast(subject)->GetChars();
}
return reinterpret_cast<const byte*>(data + start_index);
}
NativeRegExpMacroAssembler::Result NativeRegExpMacroAssembler::Match(
Handle<Code> regexp_code,
Handle<String> subject,
int* offsets_vector,
int offsets_vector_length,
int previous_index) {
ASSERT(subject->IsFlat());
ASSERT(previous_index >= 0);
ASSERT(previous_index <= subject->length());
// No allocations before calling the regexp, but we can't use
// AssertNoAllocation, since regexps might be preempted, and another thread
// might do allocation anyway.
String* subject_ptr = *subject;
// Character offsets into string.
int start_offset = previous_index;
int end_offset = subject_ptr->length();
bool is_ascii = subject->IsAsciiRepresentation();
if (StringShape(subject_ptr).IsCons()) {
subject_ptr = ConsString::cast(subject_ptr)->first();
} else if (StringShape(subject_ptr).IsSliced()) {
SlicedString* slice = SlicedString::cast(subject_ptr);
start_offset += slice->start();
end_offset += slice->start();
subject_ptr = slice->buffer();
}
// Ensure that an underlying string has the same ascii-ness.
ASSERT(subject_ptr->IsAsciiRepresentation() == is_ascii);
ASSERT(subject_ptr->IsExternalString() || subject_ptr->IsSeqString());
// String is now either Sequential or External
int char_size_shift = is_ascii ? 0 : 1;
int char_length = end_offset - start_offset;
const byte* input_start =
StringCharacterPosition(subject_ptr, start_offset);
int byte_length = char_length << char_size_shift;
const byte* input_end = input_start + byte_length;
Result res = Execute(*regexp_code,
subject_ptr,
start_offset,
input_start,
input_end,
offsets_vector,
previous_index == 0);
if (res == SUCCESS) {
// Capture values are relative to start_offset only.
// Convert them to be relative to start of string.
for (int i = 0; i < offsets_vector_length; i++) {
if (offsets_vector[i] >= 0) {
offsets_vector[i] += previous_index;
}
}
}
return res;
}
NativeRegExpMacroAssembler::Result NativeRegExpMacroAssembler::Execute(
Code* code,
String* input,
int start_offset,
const byte* input_start,
const byte* input_end,
int* output,
bool at_start) {
typedef int (*matcher)(String*, int, const byte*,
const byte*, int*, int, Address);
matcher matcher_func = FUNCTION_CAST<matcher>(code->entry());
int at_start_val = at_start ? 1 : 0;
// Ensure that the minimum stack has been allocated.
RegExpStack stack;
Address stack_base = RegExpStack::stack_base();
int result = CALL_GENERATED_REGEXP_CODE(matcher_func,
input,
start_offset,
input_start,
input_end,
output,
at_start_val,
stack_base);
ASSERT(result <= SUCCESS);
ASSERT(result >= RETRY);
if (result == EXCEPTION && !Top::has_pending_exception()) {
// We detected a stack overflow (on the backtrack stack) in RegExp code,
// but haven't created the exception yet.
Top::StackOverflow();
}
return static_cast<Result>(result);
}
static unibrow::Mapping<unibrow::Ecma262Canonicalize> canonicalize;
int NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16(
Address byte_offset1,
Address byte_offset2,
size_t byte_length) {
// This function is not allowed to cause a garbage collection.
// A GC might move the calling generated code and invalidate the
// return address on the stack.
ASSERT(byte_length % 2 == 0);
uc16* substring1 = reinterpret_cast<uc16*>(byte_offset1);
uc16* substring2 = reinterpret_cast<uc16*>(byte_offset2);
size_t length = byte_length >> 1;
for (size_t i = 0; i < length; i++) {
unibrow::uchar c1 = substring1[i];
unibrow::uchar c2 = substring2[i];
if (c1 != c2) {
unibrow::uchar s1[1] = { c1 };
canonicalize.get(c1, '\0', s1);
if (s1[0] != c2) {
unibrow::uchar s2[1] = { c2 };
canonicalize.get(c2, '\0', s2);
if (s1[0] != s2[0]) {
return 0;
}
}
}
}
return 1;
}
Address NativeRegExpMacroAssembler::GrowStack(Address stack_pointer,
Address* stack_base) {
size_t size = RegExpStack::stack_capacity();
Address old_stack_base = RegExpStack::stack_base();
ASSERT(old_stack_base == *stack_base);
ASSERT(stack_pointer <= old_stack_base);
ASSERT(static_cast<size_t>(old_stack_base - stack_pointer) <= size);
Address new_stack_base = RegExpStack::EnsureCapacity(size * 2);
if (new_stack_base == NULL) {
return NULL;
}
*stack_base = new_stack_base;
intptr_t stack_content_size = old_stack_base - stack_pointer;
return new_stack_base - stack_content_size;
}
#endif // V8_NATIVE_REGEXP
} } // namespace v8::internal