diff options
Diffstat (limited to 'libsolidity/codegen')
| -rw-r--r-- | libsolidity/codegen/CompilerContext.cpp | 20 | ||||
| -rw-r--r-- | libsolidity/codegen/CompilerContext.h | 7 | ||||
| -rw-r--r-- | libsolidity/codegen/CompilerUtils.cpp | 15 | ||||
| -rw-r--r-- | libsolidity/codegen/CompilerUtils.h | 7 | ||||
| -rw-r--r-- | libsolidity/codegen/ContractCompiler.cpp | 2 | ||||
| -rw-r--r-- | libsolidity/codegen/ExpressionCompiler.cpp | 139 |
6 files changed, 178 insertions, 12 deletions
diff --git a/libsolidity/codegen/CompilerContext.cpp b/libsolidity/codegen/CompilerContext.cpp index 47333046..a35eea73 100644 --- a/libsolidity/codegen/CompilerContext.cpp +++ b/libsolidity/codegen/CompilerContext.cpp @@ -262,12 +262,20 @@ CompilerContext& CompilerContext::appendRevert() return *this << u256(0) << u256(0) << Instruction::REVERT; } -CompilerContext& CompilerContext::appendConditionalRevert() -{ - *this << Instruction::ISZERO; - eth::AssemblyItem afterTag = appendConditionalJump(); - appendRevert(); - *this << afterTag; +CompilerContext& CompilerContext::appendConditionalRevert(bool _forwardReturnData) +{ + if (_forwardReturnData && m_evmVersion.supportsReturndata()) + appendInlineAssembly(R"({ + if condition { + returndatacopy(0, 0, returndatasize()) + revert(0, returndatasize()) + } + })", {"condition"}); + else + appendInlineAssembly(R"({ + if condition { revert(0, 0) } + })", {"condition"}); + *this << Instruction::POP; return *this; } diff --git a/libsolidity/codegen/CompilerContext.h b/libsolidity/codegen/CompilerContext.h index 7b663277..098472f7 100644 --- a/libsolidity/codegen/CompilerContext.h +++ b/libsolidity/codegen/CompilerContext.h @@ -156,8 +156,11 @@ public: CompilerContext& appendConditionalInvalid(); /// Appends a REVERT(0, 0) call CompilerContext& appendRevert(); - /// Appends a conditional REVERT(0, 0) call - CompilerContext& appendConditionalRevert(); + /// Appends a conditional REVERT-call, either forwarding the RETURNDATA or providing the + /// empty string. Consumes the condition. + /// If the current EVM version does not support RETURNDATA, uses REVERT but does not forward + /// the data. + CompilerContext& appendConditionalRevert(bool _forwardReturnData = false); /// Appends a JUMP to a specific tag CompilerContext& appendJumpTo(eth::AssemblyItem const& _tag) { m_asm->appendJump(_tag); return *this; } /// Appends pushing of a new tag and @returns the new tag. diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp index 79aef7b0..b4550153 100644 --- a/libsolidity/codegen/CompilerUtils.cpp +++ b/libsolidity/codegen/CompilerUtils.cpp @@ -78,6 +78,20 @@ void CompilerUtils::toSizeAfterFreeMemoryPointer() m_context << Instruction::SWAP1; } +void CompilerUtils::revertWithStringData(Type const& _argumentType) +{ + solAssert(_argumentType.isImplicitlyConvertibleTo(*Type::fromElementaryTypeName("string memory")), ""); + fetchFreeMemoryPointer(); + m_context << (u256(FixedHash<4>::Arith(FixedHash<4>(dev::keccak256("Error(string)")))) << (256 - 32)); + m_context << Instruction::DUP2 << Instruction::MSTORE; + m_context << u256(4) << Instruction::ADD; + // Stack: <string data> <mem pos of encoding start> + abiEncode({_argumentType.shared_from_this()}, {make_shared<ArrayType>(DataLocation::Memory, true)}); + toSizeAfterFreeMemoryPointer(); + m_context << Instruction::REVERT; + m_context.adjustStackOffset(_argumentType.sizeOnStack()); +} + unsigned CompilerUtils::loadFromMemory( unsigned _offset, Type const& _type, @@ -691,6 +705,7 @@ void CompilerUtils::convertType( solAssert(enumType.numberOfMembers() > 0, "empty enum should have caused a parser error."); m_context << u256(enumType.numberOfMembers() - 1) << Instruction::DUP2 << Instruction::GT; if (_asPartOfArgumentDecoding) + // TODO: error message? m_context.appendConditionalRevert(); else m_context.appendConditionalInvalid(); diff --git a/libsolidity/codegen/CompilerUtils.h b/libsolidity/codegen/CompilerUtils.h index a32c5c6e..476a7559 100644 --- a/libsolidity/codegen/CompilerUtils.h +++ b/libsolidity/codegen/CompilerUtils.h @@ -54,6 +54,13 @@ public: /// Stack post: <size> <mem_start> void toSizeAfterFreeMemoryPointer(); + /// Appends code that performs a revert, providing the given string data. + /// Will also append an error signature corresponding to Error(string). + /// @param _argumentType the type of the string argument, will be converted to memory string. + /// Stack pre: string data + /// Stack post: + void revertWithStringData(Type const& _argumentType); + /// Loads data from memory to the stack. /// @param _offset offset in memory (or calldata) /// @param _type data type to load diff --git a/libsolidity/codegen/ContractCompiler.cpp b/libsolidity/codegen/ContractCompiler.cpp index 5cb37103..0889ac7c 100644 --- a/libsolidity/codegen/ContractCompiler.cpp +++ b/libsolidity/codegen/ContractCompiler.cpp @@ -128,6 +128,7 @@ void ContractCompiler::appendCallValueCheck() { // Throw if function is not payable but call contained ether. m_context << Instruction::CALLVALUE; + // TODO: error message? m_context.appendConditionalRevert(); } @@ -327,6 +328,7 @@ void ContractCompiler::appendFunctionSelector(ContractDefinition const& _contrac m_context << Instruction::STOP; } else + // TODO: error message here? m_context.appendRevert(); for (auto const& it: interfaceFunctions) diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp index 57d49ac6..ed5af42e 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 @@ -608,7 +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; @@ -670,8 +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: @@ -680,8 +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; @@ -900,16 +915,131 @@ 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, ""); + } + + // Cleanup actually does not clean on shrinking the type. + 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), and(selector, not(mask)))) + })", {"mem_ptr", "selector"}); + m_context << Instruction::POP; + } + + // stack now: <memory pointer> break; } case FunctionType::Kind::GasLeft: @@ -1780,6 +1910,7 @@ 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; } @@ -1822,7 +1953,7 @@ 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); |