Merge pull request #1751 from ethereum/warnLiteralExpBase

Warn if base of exponentiation operation is a literal.
This commit is contained in:
Yoichi Hirai 2017-03-10 19:25:47 +01:00 committed by GitHub
commit ef8b56a058
3 changed files with 51 additions and 0 deletions

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@ -6,6 +6,7 @@ Features:
* Code generator: Support ``revert()`` to abort with rolling back, but not consuming all gas.
* Inline assembly: Support ``revert`` (EIP140) as an opcode.
* Type system: Support explicit conversion of external function to address.
* Type system: Warn if base of exponentiation is literal (result type might be unexpected).
Bugfixes:
* Commandline interface: Always escape filenames (replace ``/``, ``:`` and ``.`` with ``_``).

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@ -1105,6 +1105,26 @@ void TypeChecker::endVisit(BinaryOperation const& _operation)
Token::isCompareOp(_operation.getOperator()) ?
make_shared<BoolType>() :
commonType;
if (_operation.getOperator() == Token::Exp)
{
if (
leftType->category() == Type::Category::RationalNumber &&
rightType->category() != Type::Category::RationalNumber
)
if ((
commonType->category() == Type::Category::Integer &&
dynamic_cast<IntegerType const&>(*commonType).numBits() != 256
) || (
commonType->category() == Type::Category::FixedPoint &&
dynamic_cast<FixedPointType const&>(*commonType).numBits() != 256
))
warning(
_operation.location(),
"Result of exponentiation has type " + commonType->toString() + " and thus "
"might overflow. Silence this warning by converting the literal to the "
"expected type."
);
}
}
bool TypeChecker::visit(FunctionCall const& _functionCall)

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@ -1663,6 +1663,36 @@ BOOST_AUTO_TEST_CASE(exp_operator_exponent_too_big)
CHECK_ERROR(sourceCode, TypeError, "");
}
BOOST_AUTO_TEST_CASE(exp_warn_literal_base)
{
char const* sourceCode = R"(
contract test {
function f() returns(uint d) {
uint8 x = 100;
return 10**x;
}
}
)";
CHECK_WARNING(sourceCode, "might overflow");
sourceCode = R"(
contract test {
function f() returns(uint d) {
uint8 x = 100;
return uint8(10)**x;
}
}
)";
CHECK_SUCCESS(sourceCode);
sourceCode = R"(
contract test {
function f() returns(uint d) {
return 2**80;
}
}
)";
CHECK_SUCCESS(sourceCode);
}
BOOST_AUTO_TEST_CASE(enum_member_access)
{
char const* text = R"(