| /* |
| * Copyright (C) 2015 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. 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. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS 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 "config.h" |
| #include "DFABytecodeCompiler.h" |
| |
| #if ENABLE(CONTENT_EXTENSIONS) |
| |
| #include "ContentExtensionRule.h" |
| #include "DFA.h" |
| #include "DFANode.h" |
| |
| namespace WebCore::ContentExtensions { |
| |
| template <typename IntType> |
| void append(Vector<DFABytecode>& bytecode, IntType value) |
| { |
| bytecode.grow(bytecode.size() + sizeof(IntType)); |
| memcpy(&bytecode[bytecode.size() - sizeof(IntType)], &value, sizeof(IntType)); |
| } |
| |
| static void append24BitUnsignedInteger(Vector<DFABytecode>& bytecode, uint32_t value) |
| { |
| append<uint16_t>(bytecode, value); |
| append<uint8_t>(bytecode, value >> 16); |
| } |
| |
| static void appendZeroes(Vector<DFABytecode>& bytecode, DFABytecodeJumpSize jumpSize) |
| { |
| switch (jumpSize) { |
| case DFABytecodeJumpSize::Int8: |
| append<int8_t>(bytecode, 0); // This value will be set when linking. |
| break; |
| case DFABytecodeJumpSize::Int16: |
| append<int16_t>(bytecode, 0); // This value will be set when linking. |
| break; |
| case DFABytecodeJumpSize::Int24: |
| append<uint16_t>(bytecode, 0); |
| append<int8_t>(bytecode, 0); // These values will be set when linking. |
| break; |
| case DFABytecodeJumpSize::Int32: |
| append<int32_t>(bytecode, 0); // This value will be set when linking. |
| break; |
| } |
| } |
| |
| template <typename IntType> |
| void setBits(Vector<DFABytecode>& bytecode, uint32_t index, IntType value) |
| { |
| RELEASE_ASSERT(index + sizeof(IntType) <= bytecode.size()); |
| ASSERT_WITH_MESSAGE(!*reinterpret_cast<IntType*>(&bytecode[index]), "Right now we should only be using setBits to overwrite values that were zero as a placeholder."); |
| *reinterpret_cast<IntType*>(&bytecode[index]) = value; |
| } |
| |
| static DFABytecodeFlagsSize bytecodeFlagsSize(ResourceFlags flags) |
| { |
| if (flags <= std::numeric_limits<uint8_t>::max()) |
| return DFABytecodeFlagsSize::UInt8; |
| if (flags <= std::numeric_limits<uint16_t>::max()) |
| return DFABytecodeFlagsSize::UInt16; |
| RELEASE_ASSERT(flags <= UInt24Max); |
| return DFABytecodeFlagsSize::UInt24; |
| } |
| |
| static DFABytecodeActionSize bytecodeActionSize(uint32_t actionWithoutFlags) |
| { |
| if (actionWithoutFlags <= std::numeric_limits<uint8_t>::max()) |
| return DFABytecodeActionSize::UInt8; |
| if (actionWithoutFlags <= std::numeric_limits<uint16_t>::max()) |
| return DFABytecodeActionSize::UInt16; |
| if (actionWithoutFlags <= UInt24Max) |
| return DFABytecodeActionSize::UInt24; |
| return DFABytecodeActionSize::UInt32; |
| } |
| |
| static size_t toSizeT(DFABytecodeFlagsSize size) |
| { |
| switch (size) { |
| case DFABytecodeFlagsSize::UInt8: |
| return sizeof(uint8_t); |
| case DFABytecodeFlagsSize::UInt16: |
| return sizeof(uint16_t); |
| case DFABytecodeFlagsSize::UInt24: |
| return UInt24Size; |
| } |
| RELEASE_ASSERT_NOT_REACHED(); |
| } |
| |
| static size_t toSizeT(DFABytecodeActionSize size) |
| { |
| switch (size) { |
| case DFABytecodeActionSize::UInt8: |
| return sizeof(uint8_t); |
| case DFABytecodeActionSize::UInt16: |
| return sizeof(uint16_t); |
| case DFABytecodeActionSize::UInt24: |
| return UInt24Size; |
| case DFABytecodeActionSize::UInt32: |
| return sizeof(uint32_t); |
| } |
| RELEASE_ASSERT_NOT_REACHED(); |
| } |
| |
| static size_t appendActionBytecodeSize(uint64_t action) |
| { |
| auto flags = static_cast<ResourceFlags>((action & ActionFlagMask) >> 32); |
| return sizeof(DFABytecodeInstruction) |
| + (flags ? toSizeT(bytecodeFlagsSize(flags)) : 0) |
| + toSizeT(bytecodeActionSize(action)); |
| } |
| |
| static void appendVariableLengthUnsignedInteger(Vector<DFABytecode>& bytecode, uint32_t integer) |
| { |
| if (integer <= std::numeric_limits<uint8_t>::max()) |
| return append<uint8_t>(bytecode, integer); |
| if (integer <= std::numeric_limits<uint16_t>::max()) |
| return append<uint16_t>(bytecode, integer); |
| if (integer <= UInt24Max) |
| return append24BitUnsignedInteger(bytecode, integer); |
| return append<uint32_t>(bytecode, integer); |
| } |
| |
| void DFABytecodeCompiler::emitAppendAction(uint64_t action) |
| { |
| uint32_t actionWithoutFlags = action; |
| auto actionSize = bytecodeActionSize(actionWithoutFlags); |
| |
| // High bits are used to store flags. See compileRuleList. |
| if (ResourceFlags flags = (action & ActionFlagMask) >> 32) { |
| auto flagsSize = bytecodeFlagsSize(flags); |
| auto instruction = DFABytecodeInstruction::TestFlagsAndAppendAction; |
| ASSERT(!(static_cast<uint8_t>(instruction) & static_cast<uint8_t>(flagsSize) & static_cast<uint8_t>(actionSize))); |
| append<uint8_t>(m_bytecode, static_cast<uint8_t>(instruction) | static_cast<uint8_t>(flagsSize) | static_cast<uint8_t>(actionSize)); |
| appendVariableLengthUnsignedInteger(m_bytecode, flags); |
| appendVariableLengthUnsignedInteger(m_bytecode, actionWithoutFlags); |
| return; |
| } |
| |
| auto instruction = DFABytecodeInstruction::AppendAction; |
| ASSERT(!(static_cast<uint8_t>(instruction) & static_cast<uint8_t>(actionSize))); |
| append<uint8_t>(m_bytecode, static_cast<uint8_t>(instruction) | static_cast<uint8_t>(actionSize)); |
| appendVariableLengthUnsignedInteger(m_bytecode, actionWithoutFlags); |
| } |
| |
| int32_t DFABytecodeCompiler::longestPossibleJump(uint32_t instructionLocation, uint32_t sourceNodeIndex, uint32_t destinationNodeIndex) |
| { |
| if (m_nodeStartOffsets[destinationNodeIndex] == std::numeric_limits<uint32_t>::max()) { |
| // Jumping to a node that hasn't been compiled yet, we don't know exactly how far forward we will need to jump, |
| // so make sure we have enough room for the worst possible case, the farthest possible jump |
| // which would be the distance if there were no compacted branches between this jump and its destination. |
| ASSERT(instructionLocation >= m_nodeStartOffsets[sourceNodeIndex]); |
| ASSERT(m_maxNodeStartOffsets[destinationNodeIndex] > m_maxNodeStartOffsets[sourceNodeIndex]); |
| ASSERT(m_nodeStartOffsets[sourceNodeIndex] != std::numeric_limits<uint32_t>::max()); |
| return m_maxNodeStartOffsets[destinationNodeIndex] - m_maxNodeStartOffsets[sourceNodeIndex] - (m_nodeStartOffsets[sourceNodeIndex] - instructionLocation); |
| } |
| |
| // Jumping to an already compiled node, we already know exactly where we will need to jump to. |
| ASSERT(m_nodeStartOffsets[destinationNodeIndex] <= instructionLocation); |
| return m_nodeStartOffsets[destinationNodeIndex] - instructionLocation; |
| } |
| |
| static DFABytecodeJumpSize smallestPossibleJumpSize(int32_t longestPossibleJump) |
| { |
| if (longestPossibleJump <= std::numeric_limits<int8_t>::max() && longestPossibleJump >= std::numeric_limits<int8_t>::min()) |
| return DFABytecodeJumpSize::Int8; |
| if (longestPossibleJump <= std::numeric_limits<int16_t>::max() && longestPossibleJump >= std::numeric_limits<int16_t>::min()) |
| return DFABytecodeJumpSize::Int16; |
| if (longestPossibleJump <= Int24Max && longestPossibleJump >= Int24Min) |
| return DFABytecodeJumpSize::Int24; |
| return DFABytecodeJumpSize::Int32; |
| } |
| |
| void DFABytecodeCompiler::emitJump(uint32_t sourceNodeIndex, uint32_t destinationNodeIndex) |
| { |
| uint32_t instructionLocation = m_bytecode.size(); |
| uint32_t jumpLocation = instructionLocation + sizeof(uint8_t); |
| int32_t longestPossibleJumpDistance = longestPossibleJump(instructionLocation, sourceNodeIndex, destinationNodeIndex); |
| DFABytecodeJumpSize jumpSize = smallestPossibleJumpSize(longestPossibleJumpDistance); |
| append<uint8_t>(m_bytecode, static_cast<uint8_t>(DFABytecodeInstruction::Jump) | static_cast<uint8_t>(jumpSize)); |
| |
| m_linkRecords.append(LinkRecord({jumpSize, longestPossibleJumpDistance, instructionLocation, jumpLocation, destinationNodeIndex})); |
| appendZeroes(m_bytecode, jumpSize); |
| } |
| |
| void DFABytecodeCompiler::emitCheckValue(uint8_t value, uint32_t sourceNodeIndex, uint32_t destinationNodeIndex, bool caseSensitive) |
| { |
| uint32_t instructionLocation = m_bytecode.size(); |
| uint32_t jumpLocation = instructionLocation + 2 * sizeof(uint8_t); |
| int32_t longestPossibleJumpDistance = longestPossibleJump(instructionLocation, sourceNodeIndex, destinationNodeIndex); |
| DFABytecodeJumpSize jumpSize = smallestPossibleJumpSize(longestPossibleJumpDistance); |
| DFABytecodeInstruction instruction = caseSensitive ? DFABytecodeInstruction::CheckValueCaseSensitive : DFABytecodeInstruction::CheckValueCaseInsensitive; |
| append<uint8_t>(m_bytecode, static_cast<uint8_t>(instruction) | static_cast<uint8_t>(jumpSize)); |
| append<uint8_t>(m_bytecode, value); |
| m_linkRecords.append(LinkRecord({jumpSize, longestPossibleJumpDistance, instructionLocation, jumpLocation, destinationNodeIndex})); |
| appendZeroes(m_bytecode, jumpSize); |
| } |
| |
| void DFABytecodeCompiler::emitCheckValueRange(uint8_t lowValue, uint8_t highValue, uint32_t sourceNodeIndex, uint32_t destinationNodeIndex, bool caseSensitive) |
| { |
| ASSERT_WITH_MESSAGE(lowValue < highValue, "The instruction semantic impose lowValue is strictly less than highValue."); |
| |
| uint32_t instructionLocation = m_bytecode.size(); |
| uint32_t jumpLocation = instructionLocation + 3 * sizeof(uint8_t); |
| int32_t longestPossibleJumpDistance = longestPossibleJump(instructionLocation, sourceNodeIndex, destinationNodeIndex); |
| DFABytecodeJumpSize jumpSize = smallestPossibleJumpSize(longestPossibleJumpDistance); |
| DFABytecodeInstruction instruction = caseSensitive ? DFABytecodeInstruction::CheckValueRangeCaseSensitive : DFABytecodeInstruction::CheckValueRangeCaseInsensitive; |
| append<uint8_t>(m_bytecode, static_cast<uint8_t>(instruction) | static_cast<uint8_t>(jumpSize)); |
| append<uint8_t>(m_bytecode, lowValue); |
| append<uint8_t>(m_bytecode, highValue); |
| m_linkRecords.append(LinkRecord({jumpSize, longestPossibleJumpDistance, instructionLocation, jumpLocation, destinationNodeIndex})); |
| appendZeroes(m_bytecode, jumpSize); |
| } |
| |
| void DFABytecodeCompiler::emitTerminate() |
| { |
| append<DFABytecodeInstruction>(m_bytecode, DFABytecodeInstruction::Terminate); |
| } |
| |
| void DFABytecodeCompiler::compileNode(uint32_t index, bool root) |
| { |
| unsigned startSize = m_bytecode.size(); |
| |
| const DFANode& node = m_dfa.nodes[index]; |
| if (node.isKilled()) { |
| ASSERT(m_nodeStartOffsets[index] == std::numeric_limits<uint32_t>::max()); |
| return; |
| } |
| |
| // Record starting index for linking. |
| if (!root) |
| m_nodeStartOffsets[index] = m_bytecode.size(); |
| |
| for (uint64_t action : node.actions(m_dfa)) |
| emitAppendAction(action); |
| |
| // If we jump to the root, we don't want to re-add its actions to a HashSet. |
| // We know we have already added them because the root is always compiled first and we always start interpreting at the beginning. |
| if (root) |
| m_nodeStartOffsets[index] = m_bytecode.size(); |
| |
| compileNodeTransitions(index); |
| |
| ASSERT_UNUSED(startSize, m_bytecode.size() - startSize <= compiledNodeMaxBytecodeSize(index)); |
| } |
| |
| unsigned DFABytecodeCompiler::compiledNodeMaxBytecodeSize(uint32_t index) |
| { |
| const DFANode& node = m_dfa.nodes[index]; |
| if (node.isKilled()) |
| return 0; |
| unsigned size = 0; |
| for (uint64_t action : node.actions(m_dfa)) |
| size += appendActionBytecodeSize(action); |
| size += nodeTransitionsMaxBytecodeSize(node); |
| return size; |
| } |
| |
| DFABytecodeCompiler::JumpTable DFABytecodeCompiler::extractJumpTable(Vector<DFABytecodeCompiler::Range>& ranges, unsigned firstRange, unsigned lastRange) |
| { |
| ASSERT(lastRange > firstRange); |
| ASSERT(lastRange < ranges.size()); |
| |
| JumpTable jumpTable; |
| jumpTable.min = ranges[firstRange].min; |
| jumpTable.max = ranges[lastRange].max; |
| jumpTable.caseSensitive = ranges[lastRange].caseSensitive; |
| |
| unsigned size = lastRange - firstRange + 1; |
| jumpTable.destinations.reserveInitialCapacity(size); |
| for (unsigned i = firstRange; i <= lastRange; ++i) { |
| const Range& range = ranges[i]; |
| |
| ASSERT(range.caseSensitive == jumpTable.caseSensitive); |
| ASSERT(range.min == range.max); |
| ASSERT(range.min >= jumpTable.min); |
| ASSERT(range.min <= jumpTable.max); |
| |
| jumpTable.destinations.uncheckedAppend(range.destination); |
| } |
| |
| ranges.remove(firstRange, size); |
| |
| return jumpTable; |
| } |
| |
| auto DFABytecodeCompiler::transitions(const DFANode& node) -> Transitions |
| { |
| Transitions transitions; |
| |
| uint32_t destinations[128]; |
| memset(destinations, 0xff, sizeof(destinations)); |
| const uint32_t noDestination = std::numeric_limits<uint32_t>::max(); |
| |
| transitions.useFallbackTransition = node.canUseFallbackTransition(m_dfa); |
| if (transitions.useFallbackTransition) |
| transitions.fallbackTransitionTarget = node.bestFallbackTarget(m_dfa); |
| |
| for (const auto& transition : node.transitions(m_dfa)) { |
| uint32_t targetNodeIndex = transition.target(); |
| if (transitions.useFallbackTransition && transitions.fallbackTransitionTarget == targetNodeIndex) |
| continue; |
| |
| for (uint16_t i = transition.range().first; i <= transition.range().last; ++i) |
| destinations[i] = targetNodeIndex; |
| } |
| |
| Vector<Range>& ranges = transitions.ranges; |
| uint8_t rangeMin = 0; |
| bool hasRangeMin = false; |
| for (uint8_t i = 0; i < 128; i++) { |
| if (hasRangeMin) { |
| if (destinations[i] != destinations[rangeMin]) { |
| |
| // This is the end of a range. Check if it can be case insensitive. |
| uint8_t rangeMax = i - 1; |
| bool caseSensitive = true; |
| if (rangeMin >= 'A' && rangeMax <= 'Z') { |
| caseSensitive = false; |
| for (uint8_t rangeIndex = rangeMin; rangeIndex <= rangeMax; rangeIndex++) { |
| if (destinations[rangeMin] != destinations[toASCIILower(rangeIndex)]) { |
| caseSensitive = true; |
| break; |
| } |
| } |
| } |
| |
| if (!caseSensitive) { |
| // If all the lower-case destinations are the same as the upper-case destinations, |
| // then they will be covered by a case-insensitive range and will not need their own range. |
| for (uint8_t rangeIndex = rangeMin; rangeIndex <= rangeMax; rangeIndex++) { |
| ASSERT(destinations[rangeMin] == destinations[toASCIILower(rangeIndex)]); |
| destinations[toASCIILower(rangeIndex)] = noDestination; |
| } |
| ranges.append(Range(toASCIILower(rangeMin), toASCIILower(rangeMax), destinations[rangeMin], caseSensitive)); |
| } else |
| ranges.append(Range(rangeMin, rangeMax, destinations[rangeMin], caseSensitive)); |
| |
| if (destinations[i] == noDestination) |
| hasRangeMin = false; |
| else |
| rangeMin = i; |
| } |
| } else { |
| if (destinations[i] != noDestination) { |
| rangeMin = i; |
| hasRangeMin = true; |
| } |
| } |
| } |
| if (hasRangeMin) { |
| // Ranges are appended after passing the end of them. |
| // If a range goes to 127, we will have an uncommitted rangeMin because the loop does not check 128. |
| // If a range goes to 127, there will never be values higher than it, so checking for case-insensitive ranges would always fail. |
| ranges.append(Range(rangeMin, 127, destinations[rangeMin], true)); |
| } |
| |
| Vector<JumpTable>& jumpTables = transitions.jumpTables; |
| unsigned rangePosition = 0; |
| unsigned baseRangePosition = std::numeric_limits<unsigned>::max(); |
| Range* baseRange = nullptr; |
| while (rangePosition < ranges.size()) { |
| auto& range = ranges[rangePosition]; |
| if (baseRange) { |
| if (range.min != range.max |
| || baseRange->caseSensitive != range.caseSensitive |
| || ranges[rangePosition - 1].max + 1 != range.min) { |
| if (rangePosition - baseRangePosition > 1) { |
| jumpTables.append(extractJumpTable(ranges, baseRangePosition, rangePosition - 1)); |
| rangePosition = baseRangePosition; |
| } |
| baseRangePosition = std::numeric_limits<unsigned>::max(); |
| baseRange = nullptr; |
| } |
| } else { |
| if (range.min == range.max) { |
| baseRangePosition = rangePosition; |
| baseRange = ⦥ |
| } |
| } |
| ++rangePosition; |
| } |
| |
| if (baseRange && ranges.size() - baseRangePosition > 1) |
| jumpTables.append(extractJumpTable(ranges, baseRangePosition, ranges.size() - 1)); |
| |
| return transitions; |
| } |
| |
| unsigned DFABytecodeCompiler::checkForJumpTableMaxBytecodeSize(const JumpTable& jumpTable) |
| { |
| unsigned baselineSize = sizeof(DFABytecodeInstruction::CheckValueRangeCaseInsensitive) + 2 * sizeof(uint8_t); |
| unsigned targetsSize = (jumpTable.max - jumpTable.min + 1) * sizeof(uint32_t); |
| return baselineSize + targetsSize; |
| } |
| |
| unsigned DFABytecodeCompiler::checkForRangeMaxBytecodeSize(const Range& range) |
| { |
| if (range.min == range.max) |
| return sizeof(DFABytecodeInstruction::CheckValueCaseInsensitive) + sizeof(uint8_t) + sizeof(uint32_t); |
| return sizeof(DFABytecodeInstruction::CheckValueRangeCaseInsensitive) + 2 * sizeof(uint8_t) + sizeof(uint32_t); |
| } |
| |
| void DFABytecodeCompiler::compileJumpTable(uint32_t nodeIndex, const JumpTable& jumpTable) |
| { |
| unsigned startSize = m_bytecode.size(); |
| ASSERT_WITH_MESSAGE(jumpTable.max < 128, "The DFA engine only supports the ASCII alphabet."); |
| ASSERT(jumpTable.min <= jumpTable.max); |
| |
| uint32_t instructionLocation = m_bytecode.size(); |
| auto jumpSize = DFABytecodeJumpSize::Int8; |
| for (uint32_t destinationNodeIndex : jumpTable.destinations) { |
| int32_t longestPossibleJumpDistance = longestPossibleJump(instructionLocation, nodeIndex, destinationNodeIndex); |
| DFABytecodeJumpSize localJumpSize = smallestPossibleJumpSize(longestPossibleJumpDistance); |
| jumpSize = std::max(jumpSize, localJumpSize); |
| } |
| |
| DFABytecodeInstruction instruction = jumpTable.caseSensitive ? DFABytecodeInstruction::JumpTableCaseSensitive : DFABytecodeInstruction::JumpTableCaseInsensitive; |
| append<uint8_t>(m_bytecode, static_cast<uint8_t>(instruction) | static_cast<uint8_t>(jumpSize)); |
| append<uint8_t>(m_bytecode, jumpTable.min); |
| append<uint8_t>(m_bytecode, jumpTable.max); |
| |
| for (uint32_t destinationNodeIndex : jumpTable.destinations) { |
| int32_t longestPossibleJumpDistance = longestPossibleJump(instructionLocation, nodeIndex, destinationNodeIndex); |
| uint32_t jumpLocation = m_bytecode.size(); |
| m_linkRecords.append(LinkRecord({jumpSize, longestPossibleJumpDistance, instructionLocation, jumpLocation, destinationNodeIndex})); |
| appendZeroes(m_bytecode, jumpSize); |
| } |
| |
| ASSERT_UNUSED(startSize, m_bytecode.size() - startSize <= checkForJumpTableMaxBytecodeSize(jumpTable)); |
| } |
| |
| void DFABytecodeCompiler::compileCheckForRange(uint32_t nodeIndex, const Range& range) |
| { |
| unsigned startSize = m_bytecode.size(); |
| ASSERT_WITH_MESSAGE(range.max < 128, "The DFA engine only supports the ASCII alphabet."); |
| ASSERT(range.min <= range.max); |
| |
| if (range.min == range.max) |
| emitCheckValue(range.min, nodeIndex, range.destination, range.caseSensitive); |
| else |
| emitCheckValueRange(range.min, range.max, nodeIndex, range.destination, range.caseSensitive); |
| |
| ASSERT_UNUSED(startSize, m_bytecode.size() - startSize <= checkForRangeMaxBytecodeSize(range)); |
| } |
| |
| unsigned DFABytecodeCompiler::nodeTransitionsMaxBytecodeSize(const DFANode& node) |
| { |
| unsigned size = 0; |
| Transitions nodeTransitions = transitions(node); |
| for (const auto& jumpTable : nodeTransitions.jumpTables) |
| size += checkForJumpTableMaxBytecodeSize(jumpTable); |
| for (const auto& range : nodeTransitions.ranges) |
| size += checkForRangeMaxBytecodeSize(range); |
| if (nodeTransitions.useFallbackTransition) |
| size += sizeof(DFABytecodeInstruction::Jump) + sizeof(uint32_t); |
| else |
| size += sizeof(DFABytecodeInstruction::Terminate); |
| return size; |
| } |
| |
| void DFABytecodeCompiler::compileNodeTransitions(uint32_t nodeIndex) |
| { |
| const DFANode& node = m_dfa.nodes[nodeIndex]; |
| unsigned startSize = m_bytecode.size(); |
| |
| Transitions nodeTransitions = transitions(node); |
| for (const auto& jumpTable : nodeTransitions.jumpTables) |
| compileJumpTable(nodeIndex, jumpTable); |
| for (const auto& range : nodeTransitions.ranges) |
| compileCheckForRange(nodeIndex, range); |
| if (nodeTransitions.useFallbackTransition) |
| emitJump(nodeIndex, nodeTransitions.fallbackTransitionTarget); |
| else |
| emitTerminate(); |
| |
| ASSERT_UNUSED(startSize, m_bytecode.size() - startSize <= nodeTransitionsMaxBytecodeSize(node)); |
| } |
| |
| void DFABytecodeCompiler::compile() |
| { |
| uint32_t startLocation = m_bytecode.size(); |
| append<DFAHeader>(m_bytecode, 0); // This will be set when we are finished compiling this DFA. |
| |
| m_nodeStartOffsets.resize(m_dfa.nodes.size()); |
| for (unsigned i = 0; i < m_dfa.nodes.size(); ++i) |
| m_nodeStartOffsets[i] = std::numeric_limits<uint32_t>::max(); |
| |
| // Populate m_maxNodeStartOffsets with a worst-case index of where the node would be with no branch compaction. |
| // Compacting the branches using 1-4 byte signed jump distances should only make nodes closer together than this. |
| ASSERT(m_maxNodeStartOffsets.isEmpty()); |
| m_maxNodeStartOffsets.clear(); |
| m_maxNodeStartOffsets.resize(m_dfa.nodes.size()); |
| unsigned rootActionsSize = 0; |
| for (uint64_t action : m_dfa.nodes[m_dfa.root].actions(m_dfa)) |
| rootActionsSize += appendActionBytecodeSize(action); |
| m_maxNodeStartOffsets[m_dfa.root] = sizeof(DFAHeader) + rootActionsSize; |
| unsigned nextIndex = sizeof(DFAHeader) + compiledNodeMaxBytecodeSize(m_dfa.root); |
| for (uint32_t i = 0; i < m_dfa.nodes.size(); i++) { |
| if (i != m_dfa.root) { |
| m_maxNodeStartOffsets[i] = nextIndex; |
| nextIndex += compiledNodeMaxBytecodeSize(i); |
| } |
| } |
| |
| // Make sure the root is always at the beginning of the bytecode. |
| compileNode(m_dfa.root, true); |
| for (uint32_t i = 0; i < m_dfa.nodes.size(); i++) { |
| if (i != m_dfa.root) |
| compileNode(i, false); |
| } |
| |
| ASSERT(m_maxNodeStartOffsets.size() == m_nodeStartOffsets.size()); |
| for (unsigned i = 0; i < m_dfa.nodes.size(); ++i) { |
| if (m_nodeStartOffsets[i] != std::numeric_limits<uint32_t>::max()) |
| ASSERT(m_maxNodeStartOffsets[i] >= m_nodeStartOffsets[i]); |
| } |
| |
| // Link. |
| for (const auto& linkRecord : m_linkRecords) { |
| uint32_t destination = m_nodeStartOffsets[linkRecord.destinationNodeIndex]; |
| RELEASE_ASSERT(destination < static_cast<uint32_t>(std::numeric_limits<int32_t>::max())); |
| int32_t distance = destination - linkRecord.instructionLocation; |
| ASSERT(abs(distance) <= abs(linkRecord.longestPossibleJump)); |
| |
| switch (linkRecord.jumpSize) { |
| case DFABytecodeJumpSize::Int8: |
| RELEASE_ASSERT(distance == static_cast<int8_t>(distance)); |
| setBits<int8_t>(m_bytecode, linkRecord.jumpLocation, static_cast<int8_t>(distance)); |
| break; |
| case DFABytecodeJumpSize::Int16: |
| RELEASE_ASSERT(distance == static_cast<int16_t>(distance)); |
| setBits<int16_t>(m_bytecode, linkRecord.jumpLocation, static_cast<int16_t>(distance)); |
| break; |
| case DFABytecodeJumpSize::Int24: |
| RELEASE_ASSERT(distance >= Int24Min && distance <= Int24Max); |
| setBits<uint16_t>(m_bytecode, linkRecord.jumpLocation, static_cast<uint16_t>(distance)); |
| setBits<int8_t>(m_bytecode, linkRecord.jumpLocation + sizeof(int16_t), static_cast<int8_t>(distance >> 16)); |
| break; |
| case DFABytecodeJumpSize::Int32: |
| setBits<int32_t>(m_bytecode, linkRecord.jumpLocation, distance); |
| break; |
| } |
| } |
| |
| setBits<DFAHeader>(m_bytecode, startLocation, m_bytecode.size() - startLocation); |
| } |
| |
| } // namespace WebCore::ContentExtensions |
| |
| #endif // ENABLE(CONTENT_EXTENSIONS) |
