diff options
| -rw-r--r-- | docs/types.rst | 2 | ||||
| -rw-r--r-- | libsolidity/codegen/ExpressionCompiler.cpp | 13 | ||||
| -rw-r--r-- | test/libsolidity/SolidityEndToEndTest.cpp | 21 |
3 files changed, 33 insertions, 3 deletions
diff --git a/docs/types.rst b/docs/types.rst index 31f6b53d..d6445ed9 100644 --- a/docs/types.rst +++ b/docs/types.rst @@ -57,6 +57,8 @@ Operators: Division always truncates (it just maps to the DIV opcode of the EVM), but it does not truncate if both operators are :ref:`literals<rational_literals>` (or literal expressions). +Division by zero and modulus with zero throws an exception. + .. index:: address, balance, send, call, callcode, delegatecall .. _address: diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp index 1f93cf8c..4695ff96 100644 --- a/libsolidity/codegen/ExpressionCompiler.cpp +++ b/libsolidity/codegen/ExpressionCompiler.cpp @@ -1324,11 +1324,18 @@ void ExpressionCompiler::appendArithmeticOperatorCode(Token::Value _operator, Ty m_context << Instruction::MUL; break; case Token::Div: - m_context << (c_isSigned ? Instruction::SDIV : Instruction::DIV); - break; case Token::Mod: - m_context << (c_isSigned ? Instruction::SMOD : Instruction::MOD); + { + // Test for division by zero + m_context << Instruction::DUP2 << Instruction::ISZERO; + m_context.appendConditionalJumpTo(m_context.errorTag()); + + if (_operator == Token::Div) + m_context << (c_isSigned ? Instruction::SDIV : Instruction::DIV); + else + m_context << (c_isSigned ? Instruction::SMOD : Instruction::MOD); break; + } case Token::Exp: m_context << Instruction::EXP; break; diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp index 3920d948..647199ea 100644 --- a/test/libsolidity/SolidityEndToEndTest.cpp +++ b/test/libsolidity/SolidityEndToEndTest.cpp @@ -6208,6 +6208,27 @@ BOOST_AUTO_TEST_CASE(addmod_mulmod) BOOST_CHECK(callContractFunction("test()") == encodeArgs(u256(0))); } +BOOST_AUTO_TEST_CASE(divisiod_by_zero) +{ + char const* sourceCode = R"( + contract C { + function div(uint a, uint b) returns (uint) { + return a / b; + } + function mod(uint a, uint b) returns (uint) { + return a % b; + } + } + )"; + compileAndRun(sourceCode); + BOOST_CHECK(callContractFunction("div(uint256,uint256)", 7, 2) == encodeArgs(u256(3))); + // throws + BOOST_CHECK(callContractFunction("div(uint256,uint256)", 7, 0) == encodeArgs()); + BOOST_CHECK(callContractFunction("mod(uint256,uint256)", 7, 2) == encodeArgs(u256(1))); + // throws + BOOST_CHECK(callContractFunction("mod(uint256,uint256)", 7, 0) == encodeArgs()); +} + BOOST_AUTO_TEST_CASE(string_allocation_bug) { char const* sourceCode = R"( |