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Diffstat (limited to 'libsolidity/CompilerUtils.cpp')
| -rw-r--r-- | libsolidity/CompilerUtils.cpp | 734 |
1 files changed, 734 insertions, 0 deletions
diff --git a/libsolidity/CompilerUtils.cpp b/libsolidity/CompilerUtils.cpp new file mode 100644 index 00000000..49247581 --- /dev/null +++ b/libsolidity/CompilerUtils.cpp @@ -0,0 +1,734 @@ +/* + This file is part of cpp-ethereum. + + cpp-ethereum is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + cpp-ethereum is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with cpp-ethereum. If not, see <http://www.gnu.org/licenses/>. +*/ +/** + * @author Christian <c@ethdev.com> + * @date 2014 + * Routines used by both the compiler and the expression compiler. + */ + +#include <libsolidity/CompilerUtils.h> +#include <libsolidity/AST.h> +#include <libevmcore/Instruction.h> +#include <libevmcore/Params.h> +#include <libsolidity/ArrayUtils.h> +#include <libsolidity/LValue.h> + +using namespace std; + +namespace dev +{ +namespace solidity +{ + +const unsigned CompilerUtils::dataStartOffset = 4; +const size_t CompilerUtils::freeMemoryPointer = 64; +const unsigned CompilerUtils::identityContractAddress = 4; + +void CompilerUtils::initialiseFreeMemoryPointer() +{ + m_context << u256(freeMemoryPointer + 32); + storeFreeMemoryPointer(); +} + +void CompilerUtils::fetchFreeMemoryPointer() +{ + m_context << u256(freeMemoryPointer) << eth::Instruction::MLOAD; +} + +void CompilerUtils::storeFreeMemoryPointer() +{ + m_context << u256(freeMemoryPointer) << eth::Instruction::MSTORE; +} + +void CompilerUtils::allocateMemory() +{ + fetchFreeMemoryPointer(); + m_context << eth::Instruction::SWAP1 << eth::Instruction::DUP2 << eth::Instruction::ADD; + storeFreeMemoryPointer(); +} + +void CompilerUtils::toSizeAfterFreeMemoryPointer() +{ + fetchFreeMemoryPointer(); + m_context << eth::Instruction::DUP1 << eth::Instruction::SWAP2 << eth::Instruction::SUB; + m_context << eth::Instruction::SWAP1; +} + +unsigned CompilerUtils::loadFromMemory( + unsigned _offset, + Type const& _type, + bool _fromCalldata, + bool _padToWordBoundaries +) +{ + solAssert(_type.getCategory() != Type::Category::Array, "Unable to statically load dynamic type."); + m_context << u256(_offset); + return loadFromMemoryHelper(_type, _fromCalldata, _padToWordBoundaries); +} + +void CompilerUtils::loadFromMemoryDynamic( + Type const& _type, + bool _fromCalldata, + bool _padToWordBoundaries, + bool _keepUpdatedMemoryOffset +) +{ + solAssert(_type.getCategory() != Type::Category::Array, "Arrays not yet implemented."); + if (_keepUpdatedMemoryOffset) + m_context << eth::Instruction::DUP1; + unsigned numBytes = loadFromMemoryHelper(_type, _fromCalldata, _padToWordBoundaries); + if (_keepUpdatedMemoryOffset) + { + // update memory counter + moveToStackTop(_type.getSizeOnStack()); + m_context << u256(numBytes) << eth::Instruction::ADD; + } +} + +void CompilerUtils::storeInMemory(unsigned _offset) +{ + unsigned numBytes = prepareMemoryStore(IntegerType(256), true); + if (numBytes > 0) + m_context << u256(_offset) << eth::Instruction::MSTORE; +} + +void CompilerUtils::storeInMemoryDynamic(Type const& _type, bool _padToWordBoundaries) +{ + if (auto ref = dynamic_cast<ReferenceType const*>(&_type)) + { + solAssert(ref->location() == DataLocation::Memory, ""); + storeInMemoryDynamic(IntegerType(256), _padToWordBoundaries); + } + else if (auto str = dynamic_cast<StringLiteralType const*>(&_type)) + { + m_context << eth::Instruction::DUP1; + storeStringData(bytesConstRef(str->value())); + if (_padToWordBoundaries) + m_context << u256(((str->value().size() + 31) / 32) * 32); + else + m_context << u256(str->value().size()); + m_context << eth::Instruction::ADD; + } + else + { + unsigned numBytes = prepareMemoryStore(_type, _padToWordBoundaries); + if (numBytes > 0) + { + solAssert( + _type.getSizeOnStack() == 1, + "Memory store of types with stack size != 1 not implemented." + ); + m_context << eth::Instruction::DUP2 << eth::Instruction::MSTORE; + m_context << u256(numBytes) << eth::Instruction::ADD; + } + } +} + +void CompilerUtils::encodeToMemory( + TypePointers const& _givenTypes, + TypePointers const& _targetTypes, + bool _padToWordBoundaries, + bool _copyDynamicDataInPlace +) +{ + // stack: <v1> <v2> ... <vn> <mem> + TypePointers targetTypes = _targetTypes.empty() ? _givenTypes : _targetTypes; + solAssert(targetTypes.size() == _givenTypes.size(), ""); + for (TypePointer& t: targetTypes) + t = t->mobileType()->externalType(); + + // Stack during operation: + // <v1> <v2> ... <vn> <mem_start> <dyn_head_1> ... <dyn_head_r> <end_of_mem> + // The values dyn_head_i are added during the first loop and they point to the head part + // of the ith dynamic parameter, which is filled once the dynamic parts are processed. + + // store memory start pointer + m_context << eth::Instruction::DUP1; + + unsigned argSize = CompilerUtils::getSizeOnStack(_givenTypes); + unsigned stackPos = 0; // advances through the argument values + unsigned dynPointers = 0; // number of dynamic head pointers on the stack + for (size_t i = 0; i < _givenTypes.size(); ++i) + { + TypePointer targetType = targetTypes[i]; + solAssert(!!targetType, "Externalable type expected."); + if (targetType->isDynamicallySized() && !_copyDynamicDataInPlace) + { + // leave end_of_mem as dyn head pointer + m_context << eth::Instruction::DUP1 << u256(32) << eth::Instruction::ADD; + dynPointers++; + } + else + { + copyToStackTop(argSize - stackPos + dynPointers + 2, _givenTypes[i]->getSizeOnStack()); + solAssert(!!targetType, "Externalable type expected."); + TypePointer type = targetType; + if ( + _givenTypes[i]->dataStoredIn(DataLocation::Storage) || + _givenTypes[i]->dataStoredIn(DataLocation::CallData) || + _givenTypes[i]->getCategory() == Type::Category::StringLiteral + ) + type = _givenTypes[i]; // delay conversion + else + convertType(*_givenTypes[i], *targetType, true); + if (auto arrayType = dynamic_cast<ArrayType const*>(type.get())) + ArrayUtils(m_context).copyArrayToMemory(*arrayType, _padToWordBoundaries); + else + storeInMemoryDynamic(*type, _padToWordBoundaries); + } + stackPos += _givenTypes[i]->getSizeOnStack(); + } + + // now copy the dynamic part + // Stack: <v1> <v2> ... <vn> <mem_start> <dyn_head_1> ... <dyn_head_r> <end_of_mem> + stackPos = 0; + unsigned thisDynPointer = 0; + for (size_t i = 0; i < _givenTypes.size(); ++i) + { + TypePointer targetType = targetTypes[i]; + solAssert(!!targetType, "Externalable type expected."); + if (targetType->isDynamicallySized() && !_copyDynamicDataInPlace) + { + // copy tail pointer (=mem_end - mem_start) to memory + m_context << eth::dupInstruction(2 + dynPointers) << eth::Instruction::DUP2; + m_context << eth::Instruction::SUB; + m_context << eth::dupInstruction(2 + dynPointers - thisDynPointer); + m_context << eth::Instruction::MSTORE; + // stack: ... <end_of_mem> + if (_givenTypes[i]->getCategory() == Type::Category::StringLiteral) + { + auto const& strType = dynamic_cast<StringLiteralType const&>(*_givenTypes[i]); + m_context << u256(strType.value().size()); + storeInMemoryDynamic(IntegerType(256), true); + // stack: ... <end_of_mem'> + storeInMemoryDynamic(strType, _padToWordBoundaries); + } + else + { + solAssert(_givenTypes[i]->getCategory() == Type::Category::Array, "Unknown dynamic type."); + auto const& arrayType = dynamic_cast<ArrayType const&>(*_givenTypes[i]); + // now copy the array + copyToStackTop(argSize - stackPos + dynPointers + 2, arrayType.getSizeOnStack()); + // stack: ... <end_of_mem> <value...> + // copy length to memory + m_context << eth::dupInstruction(1 + arrayType.getSizeOnStack()); + if (arrayType.location() == DataLocation::CallData) + m_context << eth::Instruction::DUP2; // length is on stack + else if (arrayType.location() == DataLocation::Storage) + m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD; + else + { + solAssert(arrayType.location() == DataLocation::Memory, ""); + m_context << eth::Instruction::DUP2 << eth::Instruction::MLOAD; + } + // stack: ... <end_of_mem> <value...> <end_of_mem'> <length> + storeInMemoryDynamic(IntegerType(256), true); + // stack: ... <end_of_mem> <value...> <end_of_mem''> + // copy the new memory pointer + m_context << eth::swapInstruction(arrayType.getSizeOnStack() + 1) << eth::Instruction::POP; + // stack: ... <end_of_mem''> <value...> + // copy data part + ArrayUtils(m_context).copyArrayToMemory(arrayType, _padToWordBoundaries); + // stack: ... <end_of_mem'''> + } + + thisDynPointer++; + } + stackPos += _givenTypes[i]->getSizeOnStack(); + } + + // remove unneeded stack elements (and retain memory pointer) + m_context << eth::swapInstruction(argSize + dynPointers + 1); + popStackSlots(argSize + dynPointers + 1); +} + +void CompilerUtils::memoryCopy() +{ + // Stack here: size target source + // stack for call: outsize target size source value contract gas + //@TODO do not use ::CALL if less than 32 bytes? + m_context << eth::Instruction::DUP3 << eth::Instruction::SWAP1; + m_context << u256(0) << u256(identityContractAddress); + // compute gas costs + m_context << u256(32) << eth::Instruction::DUP5 << u256(31) << eth::Instruction::ADD; + m_context << eth::Instruction::DIV << u256(eth::c_identityWordGas) << eth::Instruction::MUL; + m_context << u256(eth::c_identityGas) << eth::Instruction::ADD; + m_context << eth::Instruction::CALL; + m_context << eth::Instruction::POP; // ignore return value +} + +void CompilerUtils::convertType(Type const& _typeOnStack, Type const& _targetType, bool _cleanupNeeded) +{ + // For a type extension, we need to remove all higher-order bits that we might have ignored in + // previous operations. + // @todo: store in the AST whether the operand might have "dirty" higher order bits + + if (_typeOnStack == _targetType && !_cleanupNeeded) + return; + Type::Category stackTypeCategory = _typeOnStack.getCategory(); + Type::Category targetTypeCategory = _targetType.getCategory(); + + switch (stackTypeCategory) + { + case Type::Category::FixedBytes: + { + FixedBytesType const& typeOnStack = dynamic_cast<FixedBytesType const&>(_typeOnStack); + if (targetTypeCategory == Type::Category::Integer) + { + // conversion from bytes to integer. no need to clean the high bit + // only to shift right because of opposite alignment + IntegerType const& targetIntegerType = dynamic_cast<IntegerType const&>(_targetType); + m_context << (u256(1) << (256 - typeOnStack.numBytes() * 8)) << eth::Instruction::SWAP1 << eth::Instruction::DIV; + if (targetIntegerType.getNumBits() < typeOnStack.numBytes() * 8) + convertType(IntegerType(typeOnStack.numBytes() * 8), _targetType, _cleanupNeeded); + } + else + { + // clear lower-order bytes for conversion to shorter bytes - we always clean + solAssert(targetTypeCategory == Type::Category::FixedBytes, "Invalid type conversion requested."); + FixedBytesType const& targetType = dynamic_cast<FixedBytesType const&>(_targetType); + if (targetType.numBytes() < typeOnStack.numBytes()) + { + if (targetType.numBytes() == 0) + m_context << eth::Instruction::DUP1 << eth::Instruction::XOR; + else + { + m_context << (u256(1) << (256 - targetType.numBytes() * 8)); + m_context << eth::Instruction::DUP1 << eth::Instruction::SWAP2; + m_context << eth::Instruction::DIV << eth::Instruction::MUL; + } + } + } + } + break; + case Type::Category::Enum: + solAssert(targetTypeCategory == Type::Category::Integer || targetTypeCategory == Type::Category::Enum, ""); + break; + case Type::Category::Integer: + case Type::Category::Contract: + case Type::Category::IntegerConstant: + if (targetTypeCategory == Type::Category::FixedBytes) + { + solAssert(stackTypeCategory == Type::Category::Integer || stackTypeCategory == Type::Category::IntegerConstant, + "Invalid conversion to FixedBytesType requested."); + // conversion from bytes to string. no need to clean the high bit + // only to shift left because of opposite alignment + FixedBytesType const& targetBytesType = dynamic_cast<FixedBytesType const&>(_targetType); + if (auto typeOnStack = dynamic_cast<IntegerType const*>(&_typeOnStack)) + if (targetBytesType.numBytes() * 8 > typeOnStack->getNumBits()) + cleanHigherOrderBits(*typeOnStack); + m_context << (u256(1) << (256 - targetBytesType.numBytes() * 8)) << eth::Instruction::MUL; + } + else if (targetTypeCategory == Type::Category::Enum) + // just clean + convertType(_typeOnStack, *_typeOnStack.mobileType(), true); + else + { + solAssert(targetTypeCategory == Type::Category::Integer || targetTypeCategory == Type::Category::Contract, ""); + IntegerType addressType(0, IntegerType::Modifier::Address); + IntegerType const& targetType = targetTypeCategory == Type::Category::Integer + ? dynamic_cast<IntegerType const&>(_targetType) : addressType; + if (stackTypeCategory == Type::Category::IntegerConstant) + { + IntegerConstantType const& constType = dynamic_cast<IntegerConstantType const&>(_typeOnStack); + // We know that the stack is clean, we only have to clean for a narrowing conversion + // where cleanup is forced. + if (targetType.getNumBits() < constType.getIntegerType()->getNumBits() && _cleanupNeeded) + cleanHigherOrderBits(targetType); + } + else + { + IntegerType const& typeOnStack = stackTypeCategory == Type::Category::Integer + ? dynamic_cast<IntegerType const&>(_typeOnStack) : addressType; + // Widening: clean up according to source type width + // Non-widening and force: clean up according to target type bits + if (targetType.getNumBits() > typeOnStack.getNumBits()) + cleanHigherOrderBits(typeOnStack); + else if (_cleanupNeeded) + cleanHigherOrderBits(targetType); + } + } + break; + case Type::Category::StringLiteral: + { + auto const& literalType = dynamic_cast<StringLiteralType const&>(_typeOnStack); + string const& value = literalType.value(); + bytesConstRef data(value); + if (targetTypeCategory == Type::Category::FixedBytes) + { + solAssert(data.size() <= 32, ""); + m_context << h256::Arith(h256(data, h256::AlignLeft)); + } + else if (targetTypeCategory == Type::Category::Array) + { + auto const& arrayType = dynamic_cast<ArrayType const&>(_targetType); + solAssert(arrayType.isByteArray(), ""); + u256 storageSize(32 + ((data.size() + 31) / 32) * 32); + m_context << storageSize; + allocateMemory(); + // stack: mempos + m_context << eth::Instruction::DUP1 << u256(data.size()); + storeInMemoryDynamic(IntegerType(256)); + // stack: mempos datapos + storeStringData(data); + break; + } + else + solAssert( + false, + "Invalid conversion from string literal to " + _targetType.toString(false) + " requested." + ); + break; + } + case Type::Category::Array: + { + solAssert(targetTypeCategory == stackTypeCategory, ""); + ArrayType const& typeOnStack = dynamic_cast<ArrayType const&>(_typeOnStack); + ArrayType const& targetType = dynamic_cast<ArrayType const&>(_targetType); + switch (targetType.location()) + { + case DataLocation::Storage: + // Other cases are done explicitly in LValue::storeValue, and only possible by assignment. + solAssert( + (targetType.isPointer() || (typeOnStack.isByteArray() && targetType.isByteArray())) && + typeOnStack.location() == DataLocation::Storage, + "Invalid conversion to storage type." + ); + break; + case DataLocation::Memory: + { + // Copy the array to a free position in memory, unless it is already in memory. + if (typeOnStack.location() != DataLocation::Memory) + { + // stack: <source ref> (variably sized) + unsigned stackSize = typeOnStack.getSizeOnStack(); + ArrayUtils(m_context).retrieveLength(typeOnStack); + + // allocate memory + // stack: <source ref> (variably sized) <length> + m_context << eth::Instruction::DUP1; + ArrayUtils(m_context).convertLengthToSize(targetType, true); + // stack: <source ref> (variably sized) <length> <size> + if (targetType.isDynamicallySized()) + m_context << u256(0x20) << eth::Instruction::ADD; + allocateMemory(); + // stack: <source ref> (variably sized) <length> <mem start> + m_context << eth::Instruction::DUP1; + moveIntoStack(2 + stackSize); + if (targetType.isDynamicallySized()) + { + m_context << eth::Instruction::DUP2; + storeInMemoryDynamic(IntegerType(256)); + } + // stack: <mem start> <source ref> (variably sized) <length> <mem data pos> + if (targetType.getBaseType()->isValueType()) + { + solAssert(typeOnStack.getBaseType()->isValueType(), ""); + copyToStackTop(2 + stackSize, stackSize); + ArrayUtils(m_context).copyArrayToMemory(typeOnStack); + } + else + { + m_context << u256(0) << eth::Instruction::SWAP1; + // stack: <mem start> <source ref> (variably sized) <length> <counter> <mem data pos> + auto repeat = m_context.newTag(); + m_context << repeat; + m_context << eth::Instruction::DUP3 << eth::Instruction::DUP3; + m_context << eth::Instruction::LT << eth::Instruction::ISZERO; + auto loopEnd = m_context.appendConditionalJump(); + copyToStackTop(3 + stackSize, stackSize); + copyToStackTop(2 + stackSize, 1); + ArrayUtils(m_context).accessIndex(typeOnStack, false); + if (typeOnStack.location() == DataLocation::Storage) + StorageItem(m_context, *typeOnStack.getBaseType()).retrieveValue(SourceLocation(), true); + convertType(*typeOnStack.getBaseType(), *targetType.getBaseType(), _cleanupNeeded); + storeInMemoryDynamic(*targetType.getBaseType(), true); + m_context << eth::Instruction::SWAP1 << u256(1) << eth::Instruction::ADD; + m_context << eth::Instruction::SWAP1; + m_context.appendJumpTo(repeat); + m_context << loopEnd; + m_context << eth::Instruction::POP; + } + // stack: <mem start> <source ref> (variably sized) <length> <mem data pos updated> + popStackSlots(2 + stackSize); + // Stack: <mem start> + } + break; + } + case DataLocation::CallData: + solAssert( + targetType.isByteArray() && + typeOnStack.isByteArray() && + typeOnStack.location() == DataLocation::CallData, + "Invalid conversion to calldata type."); + break; + default: + solAssert( + false, + "Invalid type conversion " + + _typeOnStack.toString(false) + + " to " + + _targetType.toString(false) + + " requested." + ); + } + break; + } + case Type::Category::Struct: + { + solAssert(targetTypeCategory == stackTypeCategory, ""); + auto& targetType = dynamic_cast<StructType const&>(_targetType); + auto& typeOnStack = dynamic_cast<StructType const&>(_typeOnStack); + solAssert( + targetType.location() != DataLocation::CallData && + typeOnStack.location() != DataLocation::CallData + , ""); + switch (targetType.location()) + { + case DataLocation::Storage: + // Other cases are done explicitly in LValue::storeValue, and only possible by assignment. + solAssert( + targetType.isPointer() && + typeOnStack.location() == DataLocation::Storage, + "Invalid conversion to storage type." + ); + break; + case DataLocation::Memory: + // Copy the array to a free position in memory, unless it is already in memory. + if (typeOnStack.location() != DataLocation::Memory) + { + solAssert(typeOnStack.location() == DataLocation::Storage, ""); + // stack: <source ref> + m_context << typeOnStack.memorySize(); + allocateMemory(); + m_context << eth::Instruction::SWAP1 << eth::Instruction::DUP2; + // stack: <memory ptr> <source ref> <memory ptr> + for (auto const& member: typeOnStack.getMembers()) + { + if (!member.type->canLiveOutsideStorage()) + continue; + pair<u256, unsigned> const& offsets = typeOnStack.getStorageOffsetsOfMember(member.name); + m_context << offsets.first << eth::Instruction::DUP3 << eth::Instruction::ADD; + m_context << u256(offsets.second); + StorageItem(m_context, *member.type).retrieveValue(SourceLocation(), true); + TypePointer targetMemberType = targetType.getMemberType(member.name); + solAssert(!!targetMemberType, "Member not found in target type."); + convertType(*member.type, *targetMemberType, true); + storeInMemoryDynamic(*targetMemberType, true); + } + m_context << eth::Instruction::POP << eth::Instruction::POP; + } + break; + case DataLocation::CallData: + solAssert(false, "Invalid type conversion target location CallData."); + break; + } + break; + } + default: + // All other types should not be convertible to non-equal types. + solAssert(_typeOnStack == _targetType, "Invalid type conversion requested."); + break; + } +} + +void CompilerUtils::pushZeroValue(const Type& _type) +{ + auto const* referenceType = dynamic_cast<ReferenceType const*>(&_type); + if (!referenceType || referenceType->location() == DataLocation::Storage) + { + for (size_t i = 0; i < _type.getSizeOnStack(); ++i) + m_context << u256(0); + return; + } + solAssert(referenceType->location() == DataLocation::Memory, ""); + + m_context << u256(max(32u, _type.getCalldataEncodedSize())); + allocateMemory(); + m_context << eth::Instruction::DUP1; + + if (auto structType = dynamic_cast<StructType const*>(&_type)) + for (auto const& member: structType->getMembers()) + { + pushZeroValue(*member.type); + storeInMemoryDynamic(*member.type); + } + else if (auto arrayType = dynamic_cast<ArrayType const*>(&_type)) + { + if (arrayType->isDynamicallySized()) + { + // zero length + m_context << u256(0); + storeInMemoryDynamic(IntegerType(256)); + } + else if (arrayType->getLength() > 0) + { + m_context << arrayType->getLength() << eth::Instruction::SWAP1; + // stack: items_to_do memory_pos + auto repeat = m_context.newTag(); + m_context << repeat; + pushZeroValue(*arrayType->getBaseType()); + storeInMemoryDynamic(*arrayType->getBaseType()); + m_context << eth::Instruction::SWAP1 << u256(1) << eth::Instruction::SWAP1; + m_context << eth::Instruction::SUB << eth::Instruction::SWAP1; + m_context << eth::Instruction::DUP2; + m_context.appendConditionalJumpTo(repeat); + m_context << eth::Instruction::SWAP1 << eth::Instruction::POP; + } + } + else + solAssert(false, "Requested initialisation for unknown type: " + _type.toString()); + + // remove the updated memory pointer + m_context << eth::Instruction::POP; +} + +void CompilerUtils::moveToStackVariable(VariableDeclaration const& _variable) +{ + unsigned const stackPosition = m_context.baseToCurrentStackOffset(m_context.getBaseStackOffsetOfVariable(_variable)); + unsigned const size = _variable.getType()->getSizeOnStack(); + solAssert(stackPosition >= size, "Variable size and position mismatch."); + // move variable starting from its top end in the stack + if (stackPosition - size + 1 > 16) + BOOST_THROW_EXCEPTION( + CompilerError() << + errinfo_sourceLocation(_variable.getLocation()) << + errinfo_comment("Stack too deep, try removing local variables.") + ); + for (unsigned i = 0; i < size; ++i) + m_context << eth::swapInstruction(stackPosition - size + 1) << eth::Instruction::POP; +} + +void CompilerUtils::copyToStackTop(unsigned _stackDepth, unsigned _itemSize) +{ + solAssert(_stackDepth <= 16, "Stack too deep, try removing local variables."); + for (unsigned i = 0; i < _itemSize; ++i) + m_context << eth::dupInstruction(_stackDepth); +} + +void CompilerUtils::moveToStackTop(unsigned _stackDepth) +{ + solAssert(_stackDepth <= 15, "Stack too deep, try removing local variables."); + for (unsigned i = 0; i < _stackDepth; ++i) + m_context << eth::swapInstruction(1 + i); +} + +void CompilerUtils::moveIntoStack(unsigned _stackDepth) +{ + solAssert(_stackDepth <= 16, "Stack too deep, try removing local variables."); + for (unsigned i = _stackDepth; i > 0; --i) + m_context << eth::swapInstruction(i); +} + +void CompilerUtils::popStackElement(Type const& _type) +{ + popStackSlots(_type.getSizeOnStack()); +} + +void CompilerUtils::popStackSlots(size_t _amount) +{ + for (size_t i = 0; i < _amount; ++i) + m_context << eth::Instruction::POP; +} + +unsigned CompilerUtils::getSizeOnStack(vector<shared_ptr<Type const>> const& _variableTypes) +{ + unsigned size = 0; + for (shared_ptr<Type const> const& type: _variableTypes) + size += type->getSizeOnStack(); + return size; +} + +void CompilerUtils::computeHashStatic() +{ + storeInMemory(0); + m_context << u256(32) << u256(0) << eth::Instruction::SHA3; +} + +void CompilerUtils::storeStringData(bytesConstRef _data) +{ + //@todo provide both alternatives to the optimiser + // stack: mempos + if (_data.size() <= 128) + { + for (unsigned i = 0; i < _data.size(); i += 32) + { + m_context << h256::Arith(h256(_data.cropped(i), h256::AlignLeft)); + storeInMemoryDynamic(IntegerType(256)); + } + m_context << eth::Instruction::POP; + } + else + { + // stack: mempos mempos_data + m_context.appendData(_data.toBytes()); + m_context << u256(_data.size()) << eth::Instruction::SWAP2; + m_context << eth::Instruction::CODECOPY; + } +} + +unsigned CompilerUtils::loadFromMemoryHelper(Type const& _type, bool _fromCalldata, bool _padToWordBoundaries) +{ + unsigned numBytes = _type.getCalldataEncodedSize(_padToWordBoundaries); + bool leftAligned = _type.getCategory() == Type::Category::FixedBytes; + if (numBytes == 0) + m_context << eth::Instruction::POP << u256(0); + else + { + solAssert(numBytes <= 32, "Static memory load of more than 32 bytes requested."); + m_context << (_fromCalldata ? eth::Instruction::CALLDATALOAD : eth::Instruction::MLOAD); + if (numBytes != 32) + { + // add leading or trailing zeros by dividing/multiplying depending on alignment + u256 shiftFactor = u256(1) << ((32 - numBytes) * 8); + m_context << shiftFactor << eth::Instruction::SWAP1 << eth::Instruction::DIV; + if (leftAligned) + m_context << shiftFactor << eth::Instruction::MUL; + } + } + + return numBytes; +} + +void CompilerUtils::cleanHigherOrderBits(IntegerType const& _typeOnStack) +{ + if (_typeOnStack.getNumBits() == 256) + return; + else if (_typeOnStack.isSigned()) + m_context << u256(_typeOnStack.getNumBits() / 8 - 1) << eth::Instruction::SIGNEXTEND; + else + m_context << ((u256(1) << _typeOnStack.getNumBits()) - 1) << eth::Instruction::AND; +} + +unsigned CompilerUtils::prepareMemoryStore(Type const& _type, bool _padToWordBoundaries) const +{ + unsigned numBytes = _type.getCalldataEncodedSize(_padToWordBoundaries); + bool leftAligned = _type.getCategory() == Type::Category::FixedBytes; + if (numBytes == 0) + m_context << eth::Instruction::POP; + else + { + solAssert(numBytes <= 32, "Memory store of more than 32 bytes requested."); + if (numBytes != 32 && !leftAligned && !_padToWordBoundaries) + // shift the value accordingly before storing + m_context << (u256(1) << ((32 - numBytes) * 8)) << eth::Instruction::MUL; + } + return numBytes; +} + +} +} |