diff options
7 files changed, 263 insertions, 23 deletions
diff --git a/docs/types.rst b/docs/types.rst index c216fd83..251f1edd 100644 --- a/docs/types.rst +++ b/docs/types.rst @@ -426,8 +426,26 @@ function type should not return anything, the whole ``returns (<return types>)`` part has to be omitted. By default, function types are internal, so the ``internal`` keyword can be -omitted. In contrast, contract functions themselves are public by default, -only when used as the name of a type, the default is internal. +omitted. Note that this only applies to function types. Visibility has +to be specified explicitly for functions defined in contracts, they +do not have a default. + +A function type ``A`` is implicitly convertible to a function type ``B`` if and only if +their parameter types are identical, their return types are identical, +their internal/external property is identical and the state mutability of ``A`` +is not more restrictive than the state mutability of ``B``. In particular: + + - ``pure`` functions can be converted to ``view`` and ``non-payable`` functions + - ``view`` functions can be converted to ``non-payable`` functions + - ``payable`` functions can be converted to ``non-payable`` functions + +No other conversions are possible. + +The rule about ``payable`` and ``non-payable`` might be a little +confusing, but in essence, if a function is ``payable``, this means that it +also accepts a payment of zero Ether, so it also is ``non-payable``. +On the other hand, a ``non-payable`` function will reject Ether sent to it, +so ``non-payable`` functions cannot be converted to ``payable`` functions. If a function type variable is not initialized, calling it will result in an exception. The same happens if you call a function after using ``delete`` diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp index 0d69ae1a..9e815ca8 100644 --- a/libsolidity/ast/Types.cpp +++ b/libsolidity/ast/Types.cpp @@ -2569,28 +2569,10 @@ bool FunctionType::operator==(Type const& _other) const { if (_other.category() != category()) return false; - FunctionType const& other = dynamic_cast<FunctionType const&>(_other); - if ( - m_kind != other.m_kind || - m_stateMutability != other.stateMutability() || - m_parameterTypes.size() != other.m_parameterTypes.size() || - m_returnParameterTypes.size() != other.m_returnParameterTypes.size() - ) - return false; - - auto typeCompare = [](TypePointer const& _a, TypePointer const& _b) -> bool { return *_a == *_b; }; - if ( - !equal(m_parameterTypes.cbegin(), m_parameterTypes.cend(), other.m_parameterTypes.cbegin(), typeCompare) || - !equal(m_returnParameterTypes.cbegin(), m_returnParameterTypes.cend(), other.m_returnParameterTypes.cbegin(), typeCompare) - ) - return false; - //@todo this is ugly, but cannot be prevented right now - if (m_gasSet != other.m_gasSet || m_valueSet != other.m_valueSet) - return false; - if (bound() != other.bound()) + if (!equalExcludingStateMutability(other)) return false; - if (bound() && *selfType() != *other.selfType()) + if (m_stateMutability != other.stateMutability()) return false; return true; } @@ -2606,6 +2588,31 @@ bool FunctionType::isExplicitlyConvertibleTo(Type const& _convertTo) const return _convertTo.category() == category(); } +bool FunctionType::isImplicitlyConvertibleTo(Type const& _convertTo) const +{ + if (_convertTo.category() != category()) + return false; + + FunctionType const& convertTo = dynamic_cast<FunctionType const&>(_convertTo); + + if (!equalExcludingStateMutability(convertTo)) + return false; + + // non-payable should not be convertible to payable + if (m_stateMutability != StateMutability::Payable && convertTo.stateMutability() == StateMutability::Payable) + return false; + + // payable should be convertible to non-payable, because you are free to pay 0 ether + if (m_stateMutability == StateMutability::Payable && convertTo.stateMutability() == StateMutability::NonPayable) + return true; + + // e.g. pure should be convertible to view, but not the other way around. + if (m_stateMutability > convertTo.stateMutability()) + return false; + + return true; +} + TypePointer FunctionType::unaryOperatorResult(Token::Value _operator) const { if (_operator == Token::Value::Delete) @@ -2863,6 +2870,38 @@ bool FunctionType::hasEqualParameterTypes(FunctionType const& _other) const ); } +bool FunctionType::hasEqualReturnTypes(FunctionType const& _other) const +{ + if (m_returnParameterTypes.size() != _other.m_returnParameterTypes.size()) + return false; + return equal( + m_returnParameterTypes.cbegin(), + m_returnParameterTypes.cend(), + _other.m_returnParameterTypes.cbegin(), + [](TypePointer const& _a, TypePointer const& _b) -> bool { return *_a == *_b; } + ); +} + +bool FunctionType::equalExcludingStateMutability(FunctionType const& _other) const +{ + if (m_kind != _other.m_kind) + return false; + + if (!hasEqualParameterTypes(_other) || !hasEqualReturnTypes(_other)) + return false; + + //@todo this is ugly, but cannot be prevented right now + if (m_gasSet != _other.m_gasSet || m_valueSet != _other.m_valueSet) + return false; + + if (bound() != _other.bound()) + return false; + + solAssert(!bound() || *selfType() == *_other.selfType(), ""); + + return true; +} + bool FunctionType::isBareCall() const { switch (m_kind) diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h index 8bae3d41..cc96ac4b 100644 --- a/libsolidity/ast/Types.h +++ b/libsolidity/ast/Types.h @@ -1012,6 +1012,7 @@ public: virtual std::string richIdentifier() const override; virtual bool operator==(Type const& _other) const override; + virtual bool isImplicitlyConvertibleTo(Type const& _convertTo) const override; virtual bool isExplicitlyConvertibleTo(Type const& _convertTo) const override; virtual TypePointer unaryOperatorResult(Token::Value _operator) const override; virtual TypePointer binaryOperatorResult(Token::Value, TypePointer const&) const override; @@ -1041,8 +1042,12 @@ public: /// @param _selfType if the function is bound, this has to be supplied and is the type of the /// expression the function is called on. bool canTakeArguments(TypePointers const& _arguments, TypePointer const& _selfType = TypePointer()) const; - /// @returns true if the types of parameters are equal (doesn't check return parameter types) + /// @returns true if the types of parameters are equal (does not check return parameter types) bool hasEqualParameterTypes(FunctionType const& _other) const; + /// @returns true iff the return types are equal (does not check parameter types) + bool hasEqualReturnTypes(FunctionType const& _other) const; + /// @returns true iff the function type is equal to the given type, ignoring state mutability differences. + bool equalExcludingStateMutability(FunctionType const& _other) const; /// @returns true if the ABI is used for this call (only meaningful for external calls) bool isBareCall() const; diff --git a/test/libsolidity/syntaxTests/types/function_types/function_parameter_return_types_fail.sol b/test/libsolidity/syntaxTests/types/function_types/function_parameter_return_types_fail.sol new file mode 100644 index 00000000..0d4fded1 --- /dev/null +++ b/test/libsolidity/syntaxTests/types/function_types/function_parameter_return_types_fail.sol @@ -0,0 +1,42 @@ +contract Test +{ + function uint256_to_uint256(uint256 x) internal pure returns (uint256) { return x; } + function uint256_to_string(uint256 x) internal pure returns (string memory) { return x == 0 ? "a" : "b"; } + function uint256_to_string_storage(uint256) internal pure returns (string storage); + function string_to_uint256(string memory x) internal pure returns (uint256) { return bytes(x).length; } + function string_to_string(string memory x) internal pure returns (string memory) { return x; } + + function uint256_uint256_to_uint256(uint256 x, uint256 y) internal pure returns (uint256) { return x + y; } + function uint256_uint256_to_string(uint256 x, uint256 y) internal pure returns (string memory) { return x == y ? "a" : "b"; } + function string_uint256_to_string(string memory x, uint256 y) internal pure returns (string memory) { return y == 0 ? "a" : x; } + function string_string_to_string(string memory x, string memory y) internal pure returns (string memory) { return bytes(x).length == 0 ? y : x; } + function uint256_string_to_string(uint256 x, string memory y) internal pure returns (string memory) { return x == 0 ? "a" : y; } + + function tests() internal pure + { + function (uint256) internal pure returns (uint256) var_uint256_to_uint256 = uint256_to_string; + function (uint256) internal pure returns (string memory) var_uint256_to_string = uint256_to_string_storage; + function (string memory) internal pure returns (uint256) var_string_to_uint256 = uint256_to_string; + function (string memory) internal pure returns (string memory) var_string_to_string = var_uint256_to_string; + + function (uint256, uint256) internal pure returns (uint256) var_uint256_uint256_to_uint256 = uint256_to_uint256; + function (string memory, uint256) internal pure returns (string memory) var_string_uint256_to_string = string_to_string; + function (string memory, string memory) internal pure returns (string memory) var_string_string_to_string = string_to_string; + + var_uint256_to_uint256(1); + var_uint256_to_string(2); + var_string_to_uint256("a"); + var_string_to_string("b"); + var_uint256_uint256_to_uint256(3, 4); + var_string_uint256_to_string("c", 7); + var_string_string_to_string("d", "e"); + } +} +// ---- +// TypeError: (1218-1311): Type function (uint256) pure returns (string memory) is not implicitly convertible to expected type function (uint256) pure returns (uint256). +// TypeError: (1319-1425): Type function (uint256) pure returns (string storage pointer) is not implicitly convertible to expected type function (uint256) pure returns (string memory). +// TypeError: (1433-1531): Type function (uint256) pure returns (string memory) is not implicitly convertible to expected type function (string memory) pure returns (uint256). +// TypeError: (1539-1646): Type function (uint256) pure returns (string memory) is not implicitly convertible to expected type function (string memory) pure returns (string memory). +// TypeError: (1655-1766): Type function (uint256) pure returns (uint256) is not implicitly convertible to expected type function (uint256,uint256) pure returns (uint256). +// TypeError: (1774-1893): Type function (string memory) pure returns (string memory) is not implicitly convertible to expected type function (string memory,uint256) pure returns (string memory). +// TypeError: (1901-2025): Type function (string memory) pure returns (string memory) is not implicitly convertible to expected type function (string memory,string memory) pure returns (string memory). diff --git a/test/libsolidity/syntaxTests/types/function_types/function_parameter_return_types_success.sol b/test/libsolidity/syntaxTests/types/function_types/function_parameter_return_types_success.sol new file mode 100644 index 00000000..f750632e --- /dev/null +++ b/test/libsolidity/syntaxTests/types/function_types/function_parameter_return_types_success.sol @@ -0,0 +1,39 @@ +contract Test +{ + function uint256_to_uint256(uint256 x) internal pure returns (uint256) { return x; } + function uint256_to_string(uint256 x) internal pure returns (string memory) { return x == 0 ? "a" : "b"; } + function string_to_uint256(string memory x) internal pure returns (uint256) { return bytes(x).length; } + function string_to_string(string memory x) internal pure returns (string memory) { return x; } + + function uint256_uint256_to_uint256(uint256 x, uint256 y) internal pure returns (uint256) { return x + y; } + function uint256_uint256_to_string(uint256 x, uint256 y) internal pure returns (string memory) { return x == y ? "a" : "b"; } + function string_uint256_to_string(string memory x, uint256 y) internal pure returns (string memory) { return y == 0 ? "a" : x; } + function string_string_to_string(string memory x, string memory y) internal pure returns (string memory) { return bytes(x).length == 0 ? y : x; } + function uint256_string_to_string(uint256 x, string memory y) internal pure returns (string memory) { return x == 0 ? "a" : y; } + + function tests() internal pure + { + function (uint256) internal pure returns (uint256) var_uint256_to_uint256 = uint256_to_uint256; + function (uint256) internal pure returns (string memory) var_uint256_to_string = uint256_to_string; + function (string memory) internal pure returns (uint256) var_string_to_uint256 = string_to_uint256; + function (string memory) internal pure returns (string memory) var_string_to_string = string_to_string; + + function (uint256, uint256) internal pure returns (uint256) var_uint256_uint256_to_uint256 = uint256_uint256_to_uint256; + function (uint256, uint256) internal pure returns (string memory) var_uint256_uint256_to_string = uint256_uint256_to_string; + function (string memory, uint256) internal pure returns (string memory) var_string_uint256_to_string = string_uint256_to_string; + function (string memory, string memory) internal pure returns (string memory) var_string_string_to_string = string_string_to_string; + function (uint256, string memory) internal pure returns (string memory) var_uint256_string_to_string = uint256_string_to_string; + + // Avoid unused variable warnings: + var_uint256_to_uint256(1); + var_uint256_to_string(2); + var_string_to_uint256("a"); + var_string_to_string("b"); + var_uint256_uint256_to_uint256(3, 4); + var_uint256_uint256_to_string(5, 6); + var_string_uint256_to_string("c", 7); + var_string_string_to_string("d", "e"); + var_uint256_string_to_string(8, "f"); + } +} +// ---- diff --git a/test/libsolidity/syntaxTests/types/function_types/function_state_mutability_fail.sol b/test/libsolidity/syntaxTests/types/function_types/function_state_mutability_fail.sol new file mode 100644 index 00000000..818d7840 --- /dev/null +++ b/test/libsolidity/syntaxTests/types/function_types/function_state_mutability_fail.sol @@ -0,0 +1,51 @@ +contract Test +{ + function internalPureFunc(uint256 x) internal pure returns (uint256) { return x; } + function internalViewFunc(uint256 x) internal view returns (uint256) { return x; } + function internalMutableFunc(uint256 x) internal returns (uint256) { return x; } + + function externalPureFunc(uint256 x) external pure returns (uint256) { return x; } + function externalViewFunc(uint256 x) external view returns (uint256) { return x; } + function externalPayableFunc(uint256 x) external payable returns (uint256) { return x; } + function externalMutableFunc(uint256 x) external returns (uint256) { return x; } + + function funcTakesInternalPure(function(uint256) internal pure returns(uint256) a) internal returns (uint256) { return a(4); } + function funcTakesInternalView(function(uint256) internal view returns(uint256) a) internal returns (uint256) { return a(4); } + function funcTakesInternalMutable(function(uint256) internal returns(uint256) a) internal returns (uint256) { return a(4); } + + function funcTakesExternalPure(function(uint256) external pure returns(uint256) a) internal returns (uint256) { return a(4); } + function funcTakesExternalView(function(uint256) external view returns(uint256) a) internal returns (uint256) { return a(4); } + function funcTakesExternalPayable(function(uint256) external payable returns(uint256) a) internal returns (uint256) { return a(4); } + function funcTakesExternalMutable(function(uint256) external returns(uint256) a) internal returns (uint256) { return a(4); } + + function tests() internal + { + funcTakesInternalPure(internalViewFunc); // view -> pure should fail + funcTakesInternalPure(internalMutableFunc); // mutable -> pure should fail + + funcTakesInternalView(internalMutableFunc); // mutable -> view should fail + + funcTakesExternalPure(this.externalViewFunc); // view -> pure should fail + funcTakesExternalPure(this.externalPayableFunc); // payable -> pure should fail + funcTakesExternalPure(this.externalMutableFunc); // mutable -> pure should fail + + funcTakesExternalView(this.externalPayableFunc); // payable -> view should fail + funcTakesExternalView(this.externalMutableFunc); // mutable -> view should fail + + funcTakesExternalPayable(this.externalPureFunc); // pure -> payable should fail + funcTakesExternalPayable(this.externalViewFunc); // view -> payable should fail + funcTakesExternalPayable(this.externalMutableFunc); // mutable -> payable should fail + } +} +// ---- +// TypeError: (1580-1596): Invalid type for argument in function call. Invalid implicit conversion from function (uint256) view returns (uint256) to function (uint256) pure returns (uint256) requested. +// TypeError: (1653-1672): Invalid type for argument in function call. Invalid implicit conversion from function (uint256) returns (uint256) to function (uint256) pure returns (uint256) requested. +// TypeError: (1733-1752): Invalid type for argument in function call. Invalid implicit conversion from function (uint256) returns (uint256) to function (uint256) view returns (uint256) requested. +// TypeError: (1813-1834): Invalid type for argument in function call. Invalid implicit conversion from function (uint256) view external returns (uint256) to function (uint256) pure external returns (uint256) requested. +// TypeError: (1891-1915): Invalid type for argument in function call. Invalid implicit conversion from function (uint256) payable external returns (uint256) to function (uint256) pure external returns (uint256) requested. +// TypeError: (1975-1999): Invalid type for argument in function call. Invalid implicit conversion from function (uint256) external returns (uint256) to function (uint256) pure external returns (uint256) requested. +// TypeError: (2060-2084): Invalid type for argument in function call. Invalid implicit conversion from function (uint256) payable external returns (uint256) to function (uint256) view external returns (uint256) requested. +// TypeError: (2144-2168): Invalid type for argument in function call. Invalid implicit conversion from function (uint256) external returns (uint256) to function (uint256) view external returns (uint256) requested. +// TypeError: (2232-2253): Invalid type for argument in function call. Invalid implicit conversion from function (uint256) pure external returns (uint256) to function (uint256) payable external returns (uint256) requested. +// TypeError: (2316-2337): Invalid type for argument in function call. Invalid implicit conversion from function (uint256) view external returns (uint256) to function (uint256) payable external returns (uint256) requested. +// TypeError: (2400-2424): Invalid type for argument in function call. Invalid implicit conversion from function (uint256) external returns (uint256) to function (uint256) payable external returns (uint256) requested. diff --git a/test/libsolidity/syntaxTests/types/function_types/function_state_mutability_success.sol b/test/libsolidity/syntaxTests/types/function_types/function_state_mutability_success.sol new file mode 100644 index 00000000..4ee515fc --- /dev/null +++ b/test/libsolidity/syntaxTests/types/function_types/function_state_mutability_success.sol @@ -0,0 +1,46 @@ +contract Test +{ + uint y; + function internalPureFunc(uint256 x) internal pure returns (uint256) { return x; } + function internalViewFunc(uint256 x) internal view returns (uint256) { return x + y; } + function internalMutableFunc(uint256 x) internal returns (uint256) { y = x; return x; } + + function externalPureFunc(uint256 x) external pure returns (uint256) { return x; } + function externalViewFunc(uint256 x) external view returns (uint256) { return x + y; } + function externalPayableFunc(uint256 x) external payable returns (uint256) { return x + y; } + function externalMutableFunc(uint256 x) external returns (uint256) { y = x; return x; } + + function funcTakesInternalPure(function(uint256) internal pure returns(uint256) a) internal pure returns (uint256) { return a(4); } + function funcTakesInternalView(function(uint256) internal view returns(uint256) a) internal view returns (uint256) { return a(4); } + function funcTakesInternalMutable(function(uint256) internal returns(uint256) a) internal returns (uint256) { return a(4); } + + function funcTakesExternalPure(function(uint256) external pure returns(uint256) a) internal pure returns (uint256) { return a(4); } + function funcTakesExternalView(function(uint256) external view returns(uint256) a) internal view returns (uint256) { return a(4); } + function funcTakesExternalPayable(function(uint256) external payable returns(uint256) a) internal returns (uint256) { return a(4); } + function funcTakesExternalMutable(function(uint256) external returns(uint256) a) internal returns (uint256) { return a(4); } + + function tests() internal + { + funcTakesInternalPure(internalPureFunc); + + funcTakesInternalView(internalPureFunc); + funcTakesInternalView(internalViewFunc); + + funcTakesInternalMutable(internalPureFunc); + funcTakesInternalMutable(internalViewFunc); + funcTakesInternalMutable(internalMutableFunc); + + funcTakesExternalPure(this.externalPureFunc); + + funcTakesExternalView(this.externalPureFunc); + funcTakesExternalView(this.externalViewFunc); + + funcTakesExternalPayable(this.externalPayableFunc); + + funcTakesExternalMutable(this.externalPureFunc); + funcTakesExternalMutable(this.externalViewFunc); + funcTakesExternalMutable(this.externalPayableFunc); + funcTakesExternalMutable(this.externalMutableFunc); + } +} +// ---- |