diff options
Diffstat (limited to 'libsolidity/codegen/ExpressionCompiler.cpp')
| -rw-r--r-- | libsolidity/codegen/ExpressionCompiler.cpp | 275 |
1 files changed, 226 insertions, 49 deletions
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp index 7162cb0d..3cf46a9d 100644 --- a/libsolidity/codegen/ExpressionCompiler.cpp +++ b/libsolidity/codegen/ExpressionCompiler.cpp @@ -33,6 +33,8 @@ #include <libsolidity/codegen/LValue.h> #include <libevmasm/GasMeter.h> +#include <libdevcore/Whiskers.h> + using namespace std; namespace dev @@ -139,8 +141,8 @@ void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const& utils().popStackSlots(paramTypes.size() - 1); } unsigned retSizeOnStack = 0; - solAssert(accessorType.returnParameterTypes().size() >= 1, ""); - auto const& returnTypes = accessorType.returnParameterTypes(); + auto returnTypes = accessorType.returnParameterTypes(); + solAssert(returnTypes.size() >= 1, ""); if (StructType const* structType = dynamic_cast<StructType const*>(returnType.get())) { // remove offset @@ -518,7 +520,23 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) arguments[i]->accept(*this); utils().convertType(*arguments[i]->annotation().type, *function.parameterTypes()[i]); } - _functionCall.expression().accept(*this); + + { + bool shortcutTaken = false; + if (auto identifier = dynamic_cast<Identifier const*>(&_functionCall.expression())) + if (auto functionDef = dynamic_cast<FunctionDefinition const*>(identifier->annotation().referencedDeclaration)) + { + // Do not directly visit the identifier, because this way, we can avoid + // the runtime entry label to be created at the creation time context. + CompilerContext::LocationSetter locationSetter2(m_context, *identifier); + utils().pushCombinedFunctionEntryLabel(m_context.resolveVirtualFunction(*functionDef), false); + shortcutTaken = true; + } + + if (!shortcutTaken) + _functionCall.expression().accept(*this); + } + unsigned parameterSize = CompilerUtils::sizeOnStack(function.parameterTypes()); if (function.bound()) { @@ -592,7 +610,8 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) m_context << Instruction::CREATE; // Check if zero (out of stack or not enough balance). m_context << Instruction::DUP1 << Instruction::ISZERO; - m_context.appendConditionalRevert(); + // TODO: Can we bubble up here? There might be different reasons for failure, I think. + m_context.appendConditionalRevert(true); if (function.valueSet()) m_context << swapInstruction(1) << Instruction::POP; break; @@ -654,8 +673,9 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) if (function.kind() == FunctionType::Kind::Transfer) { // Check if zero (out of stack or not enough balance). + // TODO: bubble up here, but might also be different error. m_context << Instruction::ISZERO; - m_context.appendConditionalRevert(); + m_context.appendConditionalRevert(true); } break; case FunctionType::Kind::Selfdestruct: @@ -664,8 +684,19 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) m_context << Instruction::SELFDESTRUCT; break; case FunctionType::Kind::Revert: - m_context.appendRevert(); + { + if (!arguments.empty()) + { + // function-sel(Error(string)) + encoding + solAssert(arguments.size() == 1, ""); + solAssert(function.parameterTypes().size() == 1, ""); + arguments.front()->accept(*this); + utils().revertWithStringData(*arguments.front()->annotation().type); + } + else + m_context.appendRevert(); break; + } case FunctionType::Kind::SHA3: { TypePointers argumentTypes; @@ -805,24 +836,27 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) function.kind() == FunctionType::Kind::ArrayPush ? make_shared<ArrayType>(DataLocation::Storage, paramType) : make_shared<ArrayType>(DataLocation::Storage); - // get the current length - ArrayUtils(m_context).retrieveLength(*arrayType); - m_context << Instruction::DUP1; - // stack: ArrayReference currentLength currentLength - m_context << u256(1) << Instruction::ADD; - // stack: ArrayReference currentLength newLength - m_context << Instruction::DUP3 << Instruction::DUP2; - ArrayUtils(m_context).resizeDynamicArray(*arrayType); - m_context << Instruction::SWAP2 << Instruction::SWAP1; - // stack: newLength ArrayReference oldLength - ArrayUtils(m_context).accessIndex(*arrayType, false); - // stack: newLength storageSlot slotOffset + // stack: ArrayReference arguments[0]->accept(*this); + TypePointer const& argType = arguments[0]->annotation().type; + // stack: ArrayReference argValue + utils().moveToStackTop(argType->sizeOnStack(), 1); + // stack: argValue ArrayReference + m_context << Instruction::DUP1; + ArrayUtils(m_context).incrementDynamicArraySize(*arrayType); + // stack: argValue ArrayReference newLength + m_context << Instruction::SWAP1; + // stack: argValue newLength ArrayReference + m_context << u256(1) << Instruction::DUP3 << Instruction::SUB; + // stack: argValue newLength ArrayReference (newLength-1) + ArrayUtils(m_context).accessIndex(*arrayType, false); + // stack: argValue newLength storageSlot slotOffset + utils().moveToStackTop(3, argType->sizeOnStack()); // stack: newLength storageSlot slotOffset argValue TypePointer type = arguments[0]->annotation().type->closestTemporaryType(arrayType->baseType()); solAssert(type, ""); - utils().convertType(*arguments[0]->annotation().type, *type); + utils().convertType(*argType, *type); utils().moveToStackTop(1 + type->sizeOnStack()); utils().moveToStackTop(1 + type->sizeOnStack()); // stack: newLength argValue storageSlot slotOffset @@ -834,8 +868,6 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) } case FunctionType::Kind::ObjectCreation: { - // Will allocate at the end of memory (MSIZE) and not write at all unless the base - // type is dynamically sized. ArrayType const& arrayType = dynamic_cast<ArrayType const&>(*_functionCall.annotation().type); _functionCall.expression().accept(*this); solAssert(arguments.size() == 1, ""); @@ -845,15 +877,7 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) utils().convertType(*arguments[0]->annotation().type, IntegerType(256)); // Stack: requested_length - // Allocate at max(MSIZE, freeMemoryPointer) utils().fetchFreeMemoryPointer(); - m_context << Instruction::DUP1 << Instruction::MSIZE; - m_context << Instruction::LT; - auto initialise = m_context.appendConditionalJump(); - // Free memory pointer does not point to empty memory, use MSIZE. - m_context << Instruction::POP; - m_context << Instruction::MSIZE; - m_context << initialise; // Stack: requested_length memptr m_context << Instruction::SWAP1; @@ -878,13 +902,10 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) // Check if length is zero m_context << Instruction::DUP1 << Instruction::ISZERO; auto skipInit = m_context.appendConditionalJump(); - - // We only have to initialise if the base type is a not a value type. - if (dynamic_cast<ReferenceType const*>(arrayType.baseType().get())) - { - m_context << Instruction::DUP2 << u256(32) << Instruction::ADD; - utils().zeroInitialiseMemoryArray(arrayType); - } + // Always initialize because the free memory pointer might point at + // a dirty memory area. + m_context << Instruction::DUP2 << u256(32) << Instruction::ADD; + utils().zeroInitialiseMemoryArray(arrayType); m_context << skipInit; m_context << Instruction::POP; break; @@ -894,16 +915,130 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall) { arguments.front()->accept(*this); utils().convertType(*arguments.front()->annotation().type, *function.parameterTypes().front(), false); + if (arguments.size() > 1) + { + // Users probably expect the second argument to be evaluated + // even if the condition is false, as would be the case for an actual + // function call. + solAssert(arguments.size() == 2, ""); + solAssert(function.kind() == FunctionType::Kind::Require, ""); + arguments.at(1)->accept(*this); + utils().moveIntoStack(1, arguments.at(1)->annotation().type->sizeOnStack()); + } + // Stack: <error string (unconverted)> <condition> // jump if condition was met m_context << Instruction::ISZERO << Instruction::ISZERO; auto success = m_context.appendConditionalJump(); if (function.kind() == FunctionType::Kind::Assert) // condition was not met, flag an error m_context.appendInvalid(); + else if (arguments.size() > 1) + utils().revertWithStringData(*arguments.at(1)->annotation().type); else m_context.appendRevert(); // the success branch m_context << success; + if (arguments.size() > 1) + utils().popStackElement(*arguments.at(1)->annotation().type); + break; + } + case FunctionType::Kind::ABIEncode: + case FunctionType::Kind::ABIEncodePacked: + case FunctionType::Kind::ABIEncodeWithSelector: + case FunctionType::Kind::ABIEncodeWithSignature: + { + bool const isPacked = function.kind() == FunctionType::Kind::ABIEncodePacked; + bool const hasSelectorOrSignature = + function.kind() == FunctionType::Kind::ABIEncodeWithSelector || + function.kind() == FunctionType::Kind::ABIEncodeWithSignature; + + TypePointers argumentTypes; + TypePointers targetTypes; + for (unsigned i = 0; i < arguments.size(); ++i) + { + arguments[i]->accept(*this); + // Do not keep the selector as part of the ABI encoded args + if (!hasSelectorOrSignature || i > 0) + argumentTypes.push_back(arguments[i]->annotation().type); + } + utils().fetchFreeMemoryPointer(); + // stack now: [<selector>] <arg1> .. <argN> <free_mem> + + // adjust by 32(+4) bytes to accommodate the length(+selector) + m_context << u256(32 + (hasSelectorOrSignature ? 4 : 0)) << Instruction::ADD; + // stack now: [<selector>] <arg1> .. <argN> <data_encoding_area_start> + + if (isPacked) + { + solAssert(!function.padArguments(), ""); + utils().packedEncode(argumentTypes, TypePointers()); + } + else + { + solAssert(function.padArguments(), ""); + utils().abiEncode(argumentTypes, TypePointers()); + } + utils().fetchFreeMemoryPointer(); + // stack: [<selector>] <data_encoding_area_end> <bytes_memory_ptr> + + // size is end minus start minus length slot + m_context.appendInlineAssembly(R"({ + mstore(mem_ptr, sub(sub(mem_end, mem_ptr), 0x20)) + })", {"mem_end", "mem_ptr"}); + m_context << Instruction::SWAP1; + utils().storeFreeMemoryPointer(); + // stack: [<selector>] <memory ptr> + + if (hasSelectorOrSignature) + { + // stack: <selector> <memory pointer> + solAssert(arguments.size() >= 1, ""); + TypePointer const& selectorType = arguments[0]->annotation().type; + utils().moveIntoStack(selectorType->sizeOnStack()); + TypePointer dataOnStack = selectorType; + // stack: <memory pointer> <selector> + if (function.kind() == FunctionType::Kind::ABIEncodeWithSignature) + { + // hash the signature + if (auto const* stringType = dynamic_cast<StringLiteralType const*>(selectorType.get())) + { + FixedHash<4> hash(dev::keccak256(stringType->value())); + m_context << (u256(FixedHash<4>::Arith(hash)) << (256 - 32)); + dataOnStack = make_shared<FixedBytesType>(4); + } + else + { + utils().fetchFreeMemoryPointer(); + // stack: <memory pointer> <selector> <free mem ptr> + utils().packedEncode(TypePointers{selectorType}, TypePointers()); + utils().toSizeAfterFreeMemoryPointer(); + m_context << Instruction::KECCAK256; + // stack: <memory pointer> <hash> + + dataOnStack = make_shared<FixedBytesType>(32); + } + } + else + { + solAssert(function.kind() == FunctionType::Kind::ABIEncodeWithSelector, ""); + } + + utils().convertType(*dataOnStack, FixedBytesType(4), true); + + // stack: <memory pointer> <selector> + + // load current memory, mask and combine the selector + string mask = formatNumber((u256(-1) >> 32)); + m_context.appendInlineAssembly(R"({ + let data_start := add(mem_ptr, 0x20) + let data := mload(data_start) + let mask := )" + mask + R"( + mstore(data_start, or(and(data, mask), selector)) + })", {"mem_ptr", "selector"}); + m_context << Instruction::POP; + } + + // stack now: <memory pointer> break; } case FunctionType::Kind::GasLeft: @@ -1147,6 +1282,9 @@ bool ExpressionCompiler::visit(MemberAccess const& _memberAccess) else if (member == "sig") m_context << u256(0) << Instruction::CALLDATALOAD << (u256(0xffffffff) << (256 - 32)) << Instruction::AND; + else if (member == "blockhash") + { + } else solAssert(false, "Unknown magic member."); break; @@ -1356,6 +1494,10 @@ void ExpressionCompiler::endVisit(Identifier const& _identifier) } } else if (FunctionDefinition const* functionDef = dynamic_cast<FunctionDefinition const*>(declaration)) + // If the identifier is called right away, this code is executed in visit(FunctionCall...), because + // we want to avoid having a reference to the runtime function entry point in the + // constructor context, since this would force the compiler to include unreferenced + // internal functions in the runtime contex. utils().pushCombinedFunctionEntryLabel(m_context.resolveVirtualFunction(*functionDef)); else if (auto variable = dynamic_cast<VariableDeclaration const*>(declaration)) appendVariable(*variable, static_cast<Expression const&>(_identifier)); @@ -1615,15 +1757,27 @@ void ExpressionCompiler::appendExternalFunctionCall( m_context.experimentalFeatureActive(ExperimentalFeature::V050) && m_context.evmVersion().hasStaticCall(); + bool haveReturndatacopy = m_context.evmVersion().supportsReturndata(); unsigned retSize = 0; + TypePointers returnTypes; if (returnSuccessCondition) retSize = 0; // return value actually is success condition + else if (haveReturndatacopy) + returnTypes = _functionType.returnParameterTypes(); else - for (auto const& retType: _functionType.returnParameterTypes()) + returnTypes = _functionType.returnParameterTypesWithoutDynamicTypes(); + + bool dynamicReturnSize = false; + for (auto const& retType: returnTypes) + if (retType->isDynamicallyEncoded()) { - solAssert(!retType->isDynamicallySized(), "Unable to return dynamic type from external call."); - retSize += retType->calldataEncodedSize(); + solAssert(haveReturndatacopy, ""); + dynamicReturnSize = true; + retSize = 0; + break; } + else + retSize += retType->calldataEncodedSize(); // Evaluate arguments. TypePointers argumentTypes; @@ -1755,6 +1909,7 @@ void ExpressionCompiler::appendExternalFunctionCall( if (funKind == FunctionType::Kind::External || funKind == FunctionType::Kind::CallCode || funKind == FunctionType::Kind::DelegateCall) { m_context << Instruction::DUP1 << Instruction::EXTCODESIZE << Instruction::ISZERO; + // TODO: error message? m_context.appendConditionalRevert(); existenceChecked = true; } @@ -1797,7 +1952,7 @@ void ExpressionCompiler::appendExternalFunctionCall( { //Propagate error condition (if CALL pushes 0 on stack). m_context << Instruction::ISZERO; - m_context.appendConditionalRevert(); + m_context.appendConditionalRevert(true); } utils().popStackSlots(remainsSize); @@ -1821,20 +1976,42 @@ void ExpressionCompiler::appendExternalFunctionCall( utils().fetchFreeMemoryPointer(); m_context << Instruction::SUB << Instruction::MLOAD; } - else if (!_functionType.returnParameterTypes().empty()) + else if (!returnTypes.empty()) { utils().fetchFreeMemoryPointer(); - bool memoryNeeded = false; - for (auto const& retType: _functionType.returnParameterTypes()) + // Stack: return_data_start + + // The old decoder did not allocate any memory (i.e. did not touch the free + // memory pointer), but kept references to the return data for + // (statically-sized) arrays + bool needToUpdateFreeMemoryPtr = false; + if (dynamicReturnSize || m_context.experimentalFeatureActive(ExperimentalFeature::ABIEncoderV2)) + needToUpdateFreeMemoryPtr = true; + else + for (auto const& retType: returnTypes) + if (dynamic_cast<ReferenceType const*>(retType.get())) + needToUpdateFreeMemoryPtr = true; + + // Stack: return_data_start + if (dynamicReturnSize) { - utils().loadFromMemoryDynamic(*retType, false, true, true); - if (dynamic_cast<ReferenceType const*>(retType.get())) - memoryNeeded = true; + solAssert(haveReturndatacopy, ""); + m_context.appendInlineAssembly("{ returndatacopy(return_data_start, 0, returndatasize()) }", {"return_data_start"}); } - if (memoryNeeded) - utils().storeFreeMemoryPointer(); else - m_context << Instruction::POP; + solAssert(retSize > 0, ""); + // Always use the actual return length, and not our calculated expected length, if returndatacopy is supported. + // This ensures it can catch badly formatted input from external calls. + m_context << (haveReturndatacopy ? eth::AssemblyItem(Instruction::RETURNDATASIZE) : u256(retSize)); + // Stack: return_data_start return_data_size + if (needToUpdateFreeMemoryPtr) + m_context.appendInlineAssembly(R"({ + // round size to the next multiple of 32 + let newMem := add(start, and(add(size, 0x1f), not(0x1f))) + mstore(0x40, newMem) + })", {"start", "size"}); + + utils().abiDecode(returnTypes, true, true); } } |