diff --git a/libsolidity/Compiler.cpp b/libsolidity/Compiler.cpp index 781f36800..578d63bbd 100644 --- a/libsolidity/Compiler.cpp +++ b/libsolidity/Compiler.cpp @@ -130,7 +130,6 @@ unsigned Compiler::appendCalldataUnpacker(FunctionDefinition const& _function, b { // We do not check the calldata size, everything is zero-padded. unsigned dataOffset = 1; - eth::Instruction load = _fromMemory ? eth::Instruction::MLOAD : eth::Instruction::CALLDATALOAD; //@todo this can be done more efficiently, saving some CALLDATALOAD calls for (ASTPointer const& var: _function.getParameters()) @@ -140,14 +139,8 @@ unsigned Compiler::appendCalldataUnpacker(FunctionDefinition const& _function, b BOOST_THROW_EXCEPTION(CompilerError() << errinfo_sourceLocation(var->getLocation()) << errinfo_comment("Type " + var->getType()->toString() + " not yet supported.")); - if (numBytes == 32) - m_context << u256(dataOffset) << load; - else if (var->getType()->getCategory() == Type::Category::STRING) - m_context << (u256(1) << ((32 - numBytes) * 8)) << eth::Instruction::DUP1 - << u256(dataOffset) << load << eth::Instruction::DIV << eth::Instruction::MUL; - else - m_context << (u256(1) << ((32 - numBytes) * 8)) << u256(dataOffset) - << load << eth::Instruction::DIV; + bool leftAligned = var->getType()->getCategory() == Type::Category::STRING; + CompilerUtils(m_context).loadFromMemory(dataOffset, numBytes, leftAligned, !_fromMemory); dataOffset += numBytes; } return dataOffset; @@ -168,10 +161,8 @@ void Compiler::appendReturnValuePacker(FunctionDefinition const& _function) << errinfo_sourceLocation(parameters[i]->getLocation()) << errinfo_comment("Type " + paramType.toString() + " not yet supported.")); CompilerUtils(m_context).copyToStackTop(stackDepth, paramType); - if (numBytes != 32) - if (paramType.getCategory() != Type::Category::STRING) - m_context << (u256(1) << ((32 - numBytes) * 8)) << eth::Instruction::MUL; - m_context << u256(dataOffset) << eth::Instruction::MSTORE; + bool const leftAligned = paramType.getCategory() == Type::Category::STRING; + CompilerUtils(m_context).storeInMemory(dataOffset, numBytes, leftAligned); stackDepth -= paramType.getSizeOnStack(); dataOffset += numBytes; } diff --git a/libsolidity/CompilerUtils.cpp b/libsolidity/CompilerUtils.cpp index d4dfbe3c0..0ee4a53cb 100644 --- a/libsolidity/CompilerUtils.cpp +++ b/libsolidity/CompilerUtils.cpp @@ -31,6 +31,36 @@ namespace dev namespace solidity { +void CompilerUtils::loadFromMemory(unsigned _offset, unsigned _bytes, bool _leftAligned, bool _fromCalldata) +{ + eth::Instruction load = _fromCalldata ? eth::Instruction::CALLDATALOAD : eth::Instruction::MLOAD; + if (asserts(0 < _bytes && _bytes <= 32)) + BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Memory load of 0 or more than 32 bytes requested.")); + if (_bytes == 32) + m_context << u256(_offset) << load; + else + { + // load data and add leading or trailing zeros by dividing/multiplying depending on alignment + u256 shiftFactor = u256(1) << ((32 - _bytes) * 8); + m_context << shiftFactor; + if (_leftAligned) + m_context << eth::Instruction::DUP1; + m_context << u256(_offset) << load << eth::Instruction::DIV; + if (_leftAligned) + m_context << eth::Instruction::MUL; + } +} + +void CompilerUtils::storeInMemory(unsigned _offset, unsigned _bytes, bool _leftAligned) +{ + if (asserts(0 < _bytes && _bytes <= 32)) + BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Memory store of 0 or more than 32 bytes requested.")); + if (_bytes != 32 && !_leftAligned) + // shift the value accordingly before storing + m_context << (u256(1) << ((32 - _bytes) * 8)) << eth::Instruction::MUL; + m_context << u256(_offset) << eth::Instruction::MSTORE; +} + void CompilerUtils::moveToStackVariable(VariableDeclaration const& _variable) { unsigned const stackPosition = m_context.baseToCurrentStackOffset(m_context.getBaseStackOffsetOfVariable(_variable)); diff --git a/libsolidity/CompilerUtils.h b/libsolidity/CompilerUtils.h index 4da533752..928f0e2d3 100644 --- a/libsolidity/CompilerUtils.h +++ b/libsolidity/CompilerUtils.h @@ -35,6 +35,18 @@ class CompilerUtils public: CompilerUtils(CompilerContext& _context): m_context(_context) {} + /// Loads data from memory to the stack. + /// @param _offset offset in memory (or calldata) + /// @param _bytes number of bytes to load + /// @param _leftAligned if true, store left aligned on stack (otherwise right aligned) + /// @param _fromCalldata if true, load from calldata, not from memory + void loadFromMemory(unsigned _offset, unsigned _bytes = 32, bool _leftAligned = false, bool _fromCalldata = false); + /// Stores data from stack in memory. + /// @param _offset offset in memory + /// @param _bytes number of bytes to store + /// @param _leftAligned if true, data is left aligned on stack (otherwise right aligned) + void storeInMemory(unsigned _offset, unsigned _bytes = 32, bool _leftAligned = false); + /// Moves the value that is at the top of the stack to a stack variable. void moveToStackVariable(VariableDeclaration const& _variable); /// Copies a variable of type @a _type from a stack depth of @a _stackDepth to the top of the stack. diff --git a/libsolidity/ExpressionCompiler.cpp b/libsolidity/ExpressionCompiler.cpp index 5e688f6bd..d71d98cd6 100644 --- a/libsolidity/ExpressionCompiler.cpp +++ b/libsolidity/ExpressionCompiler.cpp @@ -225,15 +225,14 @@ bool ExpressionCompiler::visit(FunctionCall& _functionCall) BOOST_THROW_EXCEPTION(CompilerError() << errinfo_sourceLocation(arguments[i]->getLocation()) << errinfo_comment("Type " + type.toString() + " not yet supported.")); - if (numBytes != 32) - if (type.getCategory() != Type::Category::STRING) - m_context << (u256(1) << ((32 - numBytes) * 8)) << eth::Instruction::MUL; - m_context << u256(dataOffset) << eth::Instruction::MSTORE; + bool const leftAligned = type.getCategory() == Type::Category::STRING; + CompilerUtils(m_context).storeInMemory(dataOffset, numBytes, leftAligned); dataOffset += numBytes; } //@todo only return the first return value for now - unsigned retSize = function.getReturnParameterTypes().empty() ? 0 - : function.getReturnParameterTypes().front()->getCalldataEncodedSize(); + Type const* firstType = function.getReturnParameterTypes().empty() ? nullptr : + function.getReturnParameterTypes().front().get(); + unsigned retSize = firstType ? firstType->getCalldataEncodedSize() : 0; // CALL arguments: outSize, outOff, inSize, inOff, value, addr, gas (stack top) m_context << u256(retSize) << u256(0) << u256(dataOffset) << u256(0) << u256(0); _functionCall.getExpression().accept(*this); // pushes addr and function index @@ -241,17 +240,10 @@ bool ExpressionCompiler::visit(FunctionCall& _functionCall) << u256(25) << eth::Instruction::GAS << eth::Instruction::SUB << eth::Instruction::CALL << eth::Instruction::POP; // @todo do not ignore failure indicator - if (retSize == 32) - m_context << u256(0) << eth::Instruction::MLOAD; - else if (retSize > 0) + if (retSize > 0) { - if (function.getReturnParameterTypes().front()->getCategory() == Type::Category::STRING) - m_context << (u256(1) << ((32 - retSize) * 8)) << eth::Instruction::DUP1 - << u256(0) << eth::Instruction::MLOAD - << eth::Instruction::DIV << eth::Instruction::MUL; - else - m_context << (u256(1) << ((32 - retSize) * 8)) - << u256(0) << eth::Instruction::MLOAD << eth::Instruction::DIV; + bool const leftAligned = firstType->getCategory() == Type::Category::STRING; + CompilerUtils(m_context).loadFromMemory(0, retSize, leftAligned); } break; } @@ -275,7 +267,8 @@ bool ExpressionCompiler::visit(FunctionCall& _functionCall) arguments.front()->accept(*this); appendTypeConversion(*arguments.front()->getType(), *function.getParameterTypes().front(), true); // @todo move this once we actually use memory - m_context << u256(0) << eth::Instruction::MSTORE << u256(32) << u256(0) << eth::Instruction::SHA3; + CompilerUtils(m_context).storeInMemory(0); + m_context << u256(32) << u256(0) << eth::Instruction::SHA3; break; case Location::ECRECOVER: case Location::SHA256: @@ -291,13 +284,13 @@ bool ExpressionCompiler::visit(FunctionCall& _functionCall) arguments[i]->accept(*this); appendTypeConversion(*arguments[i]->getType(), *function.getParameterTypes()[i], true); // @todo move this once we actually use memory - m_context << u256(i * 32) << eth::Instruction::MSTORE; + CompilerUtils(m_context).storeInMemory(i * 32); } m_context << u256(32) << u256(0) << u256(arguments.size() * 32) << u256(0) << u256(0) << contractAddress << u256(500) //@todo determine actual gas requirement << eth::Instruction::CALL - << eth::Instruction::POP - << u256(0) << eth::Instruction::MLOAD; + << eth::Instruction::POP; + CompilerUtils(m_context).loadFromMemory(0); break; } default: @@ -381,7 +374,8 @@ bool ExpressionCompiler::visit(IndexAccess& _indexAccess) *dynamic_cast(*_indexAccess.getBaseExpression().getType()).getKeyType(), true); // @todo move this once we actually use memory - m_context << u256(32) << eth::Instruction::MSTORE << u256(0) << eth::Instruction::MSTORE; + CompilerUtils(m_context).storeInMemory(0); + CompilerUtils(m_context).storeInMemory(32); m_context << u256(64) << u256(0) << eth::Instruction::SHA3; m_currentLValue = LValue(m_context, LValue::STORAGE, *_indexAccess.getType());