turnidge@google.com
2803d78dfd
Instead of passing a size in bytes to the allocation function, we now have a templatized Alloc function: zone->Alloc<Type>(len) This is better for security, as we can check for integer overflow in the size computation before performing the allocation. Before, we often failed to check this. Review URL: https://chromiumcodereview.appspot.com//10836061 git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@10254 260f80e4-7a28-3924-810f-c04153c831b5
110 lines
2.8 KiB
C++
110 lines
2.8 KiB
C++
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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#include "vm/bitmap.h"
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#include "platform/assert.h"
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#include "vm/object.h"
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namespace dart {
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bool BitmapBuilder::Get(intptr_t bit_offset) const {
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if (!InRange(bit_offset)) {
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return false;
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}
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return GetBit(bit_offset);
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}
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void BitmapBuilder::Set(intptr_t bit_offset, bool value) {
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while (!InRange(bit_offset)) {
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intptr_t new_size = size_in_bytes_ + kIncrementSizeInBytes;
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ASSERT(new_size > 0);
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uint8_t* new_bit_list =
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Isolate::Current()->current_zone()->Alloc<uint8_t>(new_size);
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ASSERT(new_bit_list != NULL);
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ASSERT(bit_list_ != NULL);
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uint8_t* old_bit_list = bit_list_;
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memmove(new_bit_list, old_bit_list, size_in_bytes_);
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memset((new_bit_list + size_in_bytes_), 0, kIncrementSizeInBytes);
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size_in_bytes_ = new_size;
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bit_list_ = new_bit_list;
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}
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SetBit(bit_offset, value);
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}
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// Return the bit offset of the highest bit set.
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intptr_t BitmapBuilder::Maximum() const {
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intptr_t bound = SizeInBits();
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for (intptr_t i = (bound - 1); i >= 0; i--) {
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if (Get(i)) return i;
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}
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return Stackmap::kNoMaximum;
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}
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// Return the bit offset of the lowest bit set.
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intptr_t BitmapBuilder::Minimum() const {
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intptr_t bound = SizeInBits();
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for (intptr_t i = 0; i < bound; i++) {
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if (Get(i)) return i;
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}
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return Stackmap::kNoMinimum;
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}
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void BitmapBuilder::SetRange(intptr_t min, intptr_t max, bool value) {
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for (intptr_t i = min; i <= max; i++) {
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Set(i, value);
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}
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}
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void BitmapBuilder::SetBits(const Stackmap& stackmap) {
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intptr_t min = stackmap.MinimumBitIndex();
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intptr_t max = stackmap.MaximumBitIndex();
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if (min == Stackmap::kNoMinimum || max == Stackmap::kNoMaximum) {
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return;
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}
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for (intptr_t i = 0; i < min; i++) {
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Set(i, false);
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}
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for (intptr_t i = min; i <= max; i++) {
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Set(i, stackmap.IsObject(i));
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}
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intptr_t bound = SizeInBits();
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for (intptr_t i = (max + 1); i < bound; i++) {
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Set(i, false);
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}
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}
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bool BitmapBuilder::GetBit(intptr_t bit_offset) const {
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ASSERT(InRange(bit_offset));
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int byte_offset = bit_offset >> kBitsPerByteLog2;
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int bit_remainder = bit_offset & (kBitsPerByte - 1);
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uint8_t mask = 1U << bit_remainder;
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ASSERT(bit_list_ != NULL);
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return ((bit_list_[byte_offset] & mask) != 0);
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}
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void BitmapBuilder::SetBit(intptr_t bit_offset, bool value) {
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ASSERT(InRange(bit_offset));
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int byte_offset = bit_offset >> kBitsPerByteLog2;
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int bit_remainder = bit_offset & (kBitsPerByte - 1);
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uint8_t mask = 1U << bit_remainder;
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uint8_t* byte_addr;
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ASSERT(bit_list_ != NULL);
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byte_addr = &(bit_list_[byte_offset]);
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if (value) {
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*byte_addr |= mask;
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} else {
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*byte_addr &= ~mask;
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}
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}
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} // namespace dart
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