cerc-io/solidity
16
0
Fork 0
mirror of https://github.com/ethereum/solidity synced 2023-10-03 13:03:40 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Implement overridding of functions by public variables

Browse Source
This commit is contained in:
Mathias Baumann 2019-11-28 16:53:13 +01:00 committed by Mathias Baumann
parent 52467108ac
commit b7d5de59c5
31 changed files with 285 additions and 68 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
Changelog.md
View File

@ -35,6 +35,7 @@ Language Features:
* Introduce ``virtual`` and ``override`` keywords.
* Modify ``push(element)`` for dynamic storage arrays such that it does not return the new length anymore.
* Yul: Introduce ``leave`` statement that exits the current function.
* Allow public variables to override external functions.
Compiler Features:
* Allow revert strings to be stripped from the binary using the ``--revert-strings`` option or the ``settings.debug.revertStrings`` setting.

23
docs/contracts/inheritance.rst
View File

@ -259,6 +259,29 @@ overridden when used with multiple inheritance:
Functions without implementation have to be marked ``virtual``
outside of interfaces.
Public state variables can override external functions if the
parameter and return types of the function matches the getter function
of the variable:
::
pragma solidity >=0.5.0 <0.7.0;
contract A
{
function f() external virtual pure returns(uint) { return 5; }
}
contract B is A
{
uint public override f;
}
.. note::
While public state variables can override external functions, they themselves cannot
be overridden.
.. _modifier-overriding:
.. index:: ! overriding;modifier

111
libsolidity/analysis/ContractLevelChecker.cpp
View File

@ -69,8 +69,8 @@ vector<ASTPointer<UserDefinedTypeName>> sortByContract(vector<ASTPointer<UserDef
return sorted;
}
template <class T>
bool hasEqualNameAndParameters(T const& _a, T const& _b)
template <class T, class B>
bool hasEqualNameAndParameters(T const& _a, B const& _b)
{
return
_a.name() == _b.name() &&
@ -243,6 +243,36 @@ void ContractLevelChecker::checkIllegalOverrides(ContractDefinition const& _cont
checkModifierOverrides(funcSet, modSet, _contract.functionModifiers());
for (auto const* stateVar: _contract.stateVariables())
{
if (!stateVar->isPublic())
continue;
bool found = false;
for (
auto it = find_if(funcSet.begin(), funcSet.end(), MatchByName{stateVar->name()});
it != funcSet.end();
it = find_if(++it, funcSet.end(), MatchByName{stateVar->name()})
)
{
if (!hasEqualNameAndParameters(*stateVar, **it))
continue;
if ((*it)->visibility() != Declaration::Visibility::External)
overrideError(*stateVar, **it, "Public state variables can only override functions with external visibility.");
else
checkFunctionOverride(*stateVar, **it);
found = true;
}
if (!found && stateVar->overrides())
m_errorReporter.typeError(
stateVar->overrides()->location(),
"Public state variable has override specified but does not override anything."
);
}
for (FunctionDefinition const* function: _contract.definedFunctions())
{
if (function->isConstructor())
@ -262,49 +292,64 @@ void ContractLevelChecker::checkIllegalOverrides(ContractDefinition const& _cont
}
}
void ContractLevelChecker::checkFunctionOverride(FunctionDefinition const& _function, FunctionDefinition const& _super)
template<class T>
void ContractLevelChecker::checkFunctionOverride(T const& _overriding, FunctionDefinition const& _super)
{
FunctionTypePointer functionType = FunctionType(_function).asCallableFunction(false);
string overridingName;
if constexpr(std::is_same<FunctionDefinition, T>::value)
overridingName = "function";
else
overridingName = "public state variable";
FunctionTypePointer functionType = FunctionType(_overriding).asCallableFunction(false);
FunctionTypePointer superType = FunctionType(_super).asCallableFunction(false);
solAssert(functionType->hasEqualParameterTypes(*superType), "");
solAssert(functionType->hasEqualParameterTypes(*superType), "Override doesn't have equal parameters!");
if (!_function.overrides())
overrideError(_function, _super, "Overriding function is missing 'override' specifier.");
if (!_overriding.overrides())
overrideError(_overriding, _super, "Overriding " + overridingName + " is missing 'override' specifier.");
if (!_super.virtualSemantics())
overrideError( _super, _function, "Trying to override non-virtual function. Did you forget to add \"virtual\"?", "Overriding function is here:");
overrideError( _super, _overriding, "Trying to override non-virtual function. Did you forget to add \"virtual\"?", "Overriding " + overridingName + " is here:");
if (!functionType->hasEqualReturnTypes(*superType))
overrideError(_function, _super, "Overriding function return types differ.");
overrideError(_overriding, _super, "Overriding " + overridingName + " return types differ.");
_function.annotation().baseFunctions.emplace(&_super);
if constexpr(std::is_same<T, FunctionDefinition>::value)
_overriding.annotation().baseFunctions.emplace(&_super);
if (_function.visibility() != _super.visibility())
if (_overriding.visibility() != _super.visibility())
{
// Visibility change from external to public is fine.
// Any other change is disallowed.
if (!(
_super.visibility() == FunctionDefinition::Visibility::External &&
_function.visibility() == FunctionDefinition::Visibility::Public
_overriding.visibility() == FunctionDefinition::Visibility::Public
))
overrideError(_function, _super, "Overriding function visibility differs.");
if (_function.stateMutability() != _super.stateMutability())
overrideError(
_function,
_super,
"Overriding function changes state mutability from \"" +
stateMutabilityToString(_super.stateMutability()) +
"\" to \"" +
stateMutabilityToString(_function.stateMutability()) +
"\"."
);
overrideError(_overriding, _super, "Overriding " + overridingName + " visibility differs.");
}
if (!_function.isImplemented() && _super.isImplemented())
overrideError(
_function,
_super,
"Overriding an implemented function with an unimplemented function is not allowed."
);
if constexpr(std::is_same<T, FunctionDefinition>::value)
{
if (_overriding.stateMutability() != _super.stateMutability())
overrideError(
_overriding,
_super,
"Overriding function changes state mutability from \"" +
stateMutabilityToString(_super.stateMutability()) +
"\" to \"" +
stateMutabilityToString(_overriding.stateMutability()) +
"\"."
);
if (!_overriding.isImplemented() && _super.isImplemented())
overrideError(
_overriding,
_super,
"Overriding an implemented function with an unimplemented function is not allowed."
);
}
}
void ContractLevelChecker::overrideListError(FunctionDefinition const& function, set<ContractDefinition const*, LessFunction> _secondary, string const& _message1, string const& _message2)
@ -332,12 +377,12 @@ void ContractLevelChecker::overrideListError(FunctionDefinition const& function,
);
}
void ContractLevelChecker::overrideError(CallableDeclaration const& function, CallableDeclaration const& super, string message, string secondaryMsg)
void ContractLevelChecker::overrideError(Declaration const& _overriding, Declaration const& _super, string _message, string _secondaryMsg)
{
m_errorReporter.typeError(
function.location(),
SecondarySourceLocation().append(secondaryMsg, super.location()),
message
_overriding.location(),
SecondarySourceLocation().append(_secondaryMsg, _super.location()),
_message
);
}

5
libsolidity/analysis/ContractLevelChecker.h
View File

@ -73,9 +73,10 @@ private:
/// Performs various checks related to @a _function overriding @a _super like
/// different return type, invalid visibility change, etc.
/// Also stores @a _super as a base function of @a _function in its AST annotations.
void checkFunctionOverride(FunctionDefinition const& _function, FunctionDefinition const& _super);
template<class T>
void checkFunctionOverride(T const& _overriding, FunctionDefinition const& _super);
void overrideListError(FunctionDefinition const& function, std::set<ContractDefinition const*, LessFunction> _secondary, std::string const& _message1, std::string const& _message2);
void overrideError(CallableDeclaration const& function, CallableDeclaration const& super, std::string message, std::string secondaryMsg = "Overridden function is here:");
void overrideError(Declaration const& _overriding, Declaration const& _super, std::string _message, std::string _secondaryMsg = "Overridden function is here:");
void checkAbstractFunctions(ContractDefinition const& _contract);
/// Checks that the base constructor arguments are properly provided.
/// Fills the list of unimplemented functions in _contract's annotations.

14
libsolidity/analysis/NameAndTypeResolver.cpp
View File

@ -346,9 +346,21 @@ void NameAndTypeResolver::importInheritedScope(ContractDefinition const& _base)
solAssert(conflictingDeclaration, "");
// Usual shadowing is not an error
if (dynamic_cast<ModifierDefinition const*>(declaration) && dynamic_cast<ModifierDefinition const*>(conflictingDeclaration))
if (
dynamic_cast<ModifierDefinition const*>(declaration) &&
dynamic_cast<ModifierDefinition const*>(conflictingDeclaration)
)
continue;
// Public state variable can override functions
if (auto varDecl = dynamic_cast<VariableDeclaration const*>(conflictingDeclaration))
if (
dynamic_cast<FunctionDefinition const*>(declaration) &&
varDecl->isStateVariable() &&
varDecl->isPublic()
)
continue;
if (declaration->location().start < conflictingDeclaration->location().start)
{
firstDeclarationLocation = declaration->location();

19
test/libsolidity/semanticTests/variables/public_state_overridding.sol Normal file
View File

@ -0,0 +1,19 @@
contract A
{
function test() external virtual returns (uint256)
{
return 5;
}
}
contract X is A
{
uint256 public override test;
function set() public { test = 2; }
}
// ----
// test() -> 0
// set() ->
// test() -> 2

2
test/libsolidity/syntaxTests/inheritance/override/function_state_variable.sol
View File

@ -1,2 +1,2 @@
interface ERC20 { function x() external returns (uint); }
contract C is ERC20 { uint public x; }
contract C is ERC20 { uint public override x; }

2
test/libsolidity/syntaxTests/inheritance/override/implement_interface_by_public_variable.sol
View File

@ -1,6 +1,6 @@
interface X { function test() external returns (uint256); }
contract Y is X {
uint256 public test = 42;
uint256 public override test = 42;
}
contract T {
constructor() public { new Y(); }

4
test/libsolidity/syntaxTests/inheritance/override/implement_internal_function_by_public_variable.sol
View File

@ -1,9 +1,9 @@
abstract contract X { function test() internal virtual returns (uint256); }
contract Y is X {
uint256 public test = 42;
uint256 public override test = 42;
}
contract T {
constructor() public { new Y(); }
}
// ----
// DeclarationError: (98-122): Identifier already declared.
// TypeError: (98-131): Public state variables can only override functions with external visibility.

6
test/libsolidity/syntaxTests/inheritance/override/implement_private_function_by_public_variable.sol
View File

@ -1,8 +1,10 @@
abstract contract X { function test() private returns (uint256) {} }
abstract contract X { function test() private virtual returns (uint256); }
contract Y is X {
uint256 public test = 42;
uint256 public override test = 42;
}
contract T {
constructor() public { new Y(); }
}
// ----
// TypeError: (97-130): Public state variables can only override functions with external visibility.
// TypeError: (22-72): "virtual" and "private" cannot be used together.

5
test/libsolidity/syntaxTests/inheritance/override/implement_public_function_by_public_variable.sol
View File

@ -1,9 +1,8 @@
abstract contract X { function test() public virtual returns (uint256); }
abstract contract X { function test() external virtual returns (uint256); }
contract Y is X {
uint256 public test = 42;
uint256 public override test = 42;
}
contract T {
constructor() public { new Y(); }
}
// ----
// DeclarationError: (96-120): Identifier already declared.

3
test/libsolidity/syntaxTests/inheritance/override/override.sol
View File

@ -1,12 +1,9 @@
abstract contract A {
int public testvar;
function test() internal virtual returns (uint256);
function test2() internal virtual returns (uint256);
}
contract X is A {
int public override testvar;
function test() internal override returns (uint256) {}
function test2() internal override(A) returns (uint256) {}
}
// ----
// DeclarationError: (171-198): Identifier already declared.

5
test/libsolidity/syntaxTests/inheritance/override/override_ambiguous.sol
View File

@ -1,5 +1,4 @@
abstract contract A {
int public testvar;
function foo() internal virtual returns (uint256);
}
abstract contract B {
@ -7,9 +6,7 @@ abstract contract B {
function test() internal virtual returns (uint256);
}
abstract contract X is A, B {
int public override testvar;
function test() internal override returns (uint256) {}
}
// ----
// DeclarationError: (257-284): Identifier already declared.
// TypeError: (226-343): Derived contract must override function "foo". Function with the same name and parameter types defined in two or more base classes.
// TypeError: (205-292): Derived contract must override function "foo". Function with the same name and parameter types defined in two or more base classes.

1
test/libsolidity/syntaxTests/inheritance/override/override_multiple.sol
View File

@ -13,7 +13,6 @@ abstract contract D {
function foo() internal virtual returns (uint256);
}
contract X is A, B, C, D {
int public override testvar;
function test() internal override returns (uint256) {}
function foo() internal override(A, B, C, D) returns (uint256) {}
}

11
test/libsolidity/syntaxTests/inheritance/override/override_multiple_duplicated.sol
View File

@ -1,5 +1,4 @@
abstract contract A {
int public testvar;
function foo() internal virtual returns (uint256);
function test(uint8 _a) internal virtual returns (uint256);
}
@ -15,13 +14,11 @@ abstract contract D {
function test() internal virtual returns (uint256);
}
abstract contract X is A, B, C, D {
int public override testvar;
function test() internal override(B, D, D) virtual returns (uint256);
function foo() internal override(A, C, B, B, B, D ,D) virtual returns (uint256);
}
// ----
// DeclarationError: (529-556): Identifier already declared.
// TypeError: (599-600): Duplicate contract "D" found in override list of "test".
// TypeError: (672-673): Duplicate contract "B" found in override list of "foo".
// TypeError: (675-676): Duplicate contract "B" found in override list of "foo".
// TypeError: (681-682): Duplicate contract "D" found in override list of "foo".
// TypeError: (548-549): Duplicate contract "D" found in override list of "test".
// TypeError: (621-622): Duplicate contract "B" found in override list of "foo".
// TypeError: (624-625): Duplicate contract "B" found in override list of "foo".
// TypeError: (630-631): Duplicate contract "D" found in override list of "foo".

5
test/libsolidity/syntaxTests/inheritance/override/override_multiple_missing.sol
View File

@ -14,10 +14,9 @@ abstract contract D {
function test() internal virtual returns (uint256);
}
abstract contract X is A, B, C, D {
int public override testvar;
function test() internal override(B, D, C) virtual returns (uint256);
function foo() internal override(A, C) virtual returns (uint256);
}
// ----
// TypeError: (563-580): Invalid contract specified in override list: C.
// TypeError: (633-647): Function needs to specify overridden contracts B and D.
// TypeError: (533-550): Invalid contract specified in override list: C.
// TypeError: (603-617): Function needs to specify overridden contracts B and D.

9
test/libsolidity/syntaxTests/inheritance/override/override_public_vars.sol Normal file
View File

@ -0,0 +1,9 @@
abstract contract A {
int public testvar;
}
abstract contract X is A {
int public override testvar;
}
// ----
// DeclarationError: (73-100): Identifier already declared.
// TypeError: (84-92): Public state variable has override specified but does not override anything.

3
test/libsolidity/syntaxTests/inheritance/override/override_return_mismatch.sol
View File

@ -6,8 +6,7 @@ abstract contract B {
function test() internal virtual returns (uint256);
}
abstract contract X is A, B {
int public override testvar;
function test() internal override virtual returns (uint256);
}
// ----
// TypeError: (203-326): Derived contract must override function "foo". Function with the same name and parameter types defined in two or more base classes.
// TypeError: (203-296): Derived contract must override function "foo". Function with the same name and parameter types defined in two or more base classes.

5
test/libsolidity/syntaxTests/inheritance/override/override_type_mismatch.sol
View File

@ -16,10 +16,9 @@ abstract contract X is A, B, C, D {
struct MyStruct { int abc; }
enum ENUM { F,G,H }
int public override testvar;
function test() internal override virtual returns (uint256);
function foo() internal override(MyStruct, ENUM, A, B, C, D) virtual returns (uint256);
}
// ----
// TypeError: (632-640): Expected contract but got struct X.MyStruct.
// TypeError: (642-646): Expected contract but got enum X.ENUM.
// TypeError: (602-610): Expected contract but got struct X.MyStruct.
// TypeError: (612-616): Expected contract but got enum X.ENUM.

8
test/libsolidity/syntaxTests/inheritance/override/public_var_no_override_but_function.sol Normal file
View File

@ -0,0 +1,8 @@
contract A {
function foo() internal virtual pure returns(uint) { return 5; }
}
contract X is A {
uint public foo;
}
// ----
// TypeError: (100-115): Public state variables can only override functions with external visibility.

7
test/libsolidity/syntaxTests/inheritance/override/public_var_same_name_but_different_args.sol Normal file
View File

@ -0,0 +1,7 @@
contract A {
function foo(uint) internal virtual pure returns(uint) { return 5; }
}
contract X is A {
uint public foo;
}
// ----

11
test/libsolidity/syntaxTests/inheritance/override/public_vars_multiple.sol Normal file
View File

@ -0,0 +1,11 @@
contract A {
function foo() external virtual pure returns(uint) { return 5; }
}
contract B {
function foo() external virtual pure returns(uint) { return 5; }
}
contract X is A, B {
uint public override foo;
}
// ----
// TypeError: (162-211): Derived contract must override function "foo". Function with the same name and parameter types defined in two or more base classes.

11
test/libsolidity/syntaxTests/inheritance/override/public_vars_multiple1.sol Normal file
View File

@ -0,0 +1,11 @@
contract A {
uint public foo;
}
contract B {
function foo() external virtual pure returns(uint) { return 5; }
}
contract X is A, B {
uint public override foo;
}
// ----
// DeclarationError: (136-160): Identifier already declared.

9
test/libsolidity/syntaxTests/inheritance/override/public_vars_multiple2.sol Normal file
View File

@ -0,0 +1,9 @@
contract A {
function foo() external virtual pure returns(uint) { return 4; }
function foo(uint ) external virtual pure returns(uint) { return 4; }
function foo(uint , uint ) external pure virtual returns(A) { }
}
contract X is A {
uint public override foo;
}
// ----

10
test/libsolidity/syntaxTests/inheritance/override/public_vars_multiple3.sol Normal file
View File

@ -0,0 +1,10 @@
contract A {
function foo() external virtual pure returns(A) { }
function foo(uint ) external virtual pure returns(uint) { return 4; }
function foo(uint , uint ) external pure virtual returns(A) { }
}
contract X is A {
uint public override foo;
}
// ----
// TypeError: (225-249): Overriding public state variable return types differ.

8
test/libsolidity/syntaxTests/inheritance/override/public_vars_multiple4.sol Normal file
View File

@ -0,0 +1,8 @@
contract ERC20 {
function balanceOf(address) external virtual view returns (uint) {}
function balanceOf(uint) external virtual view returns (uint) {}
function balanceOf() external virtual view returns (uint) {}
}
contract C is ERC20 {
mapping(address => uint) public override balanceOf;
}

10
test/libsolidity/syntaxTests/inheritance/override/public_vars_multiple5.sol Normal file
View File

@ -0,0 +1,10 @@
contract ERC20 {
function balanceOf(address, uint) external virtual view returns (uint) {}
function balanceOf(uint) external virtual view returns (uint) {}
function balanceOf() external virtual view returns (uint) {}
}
contract C is ERC20 {
mapping(address => uint) public override balanceOf;
}
// ----
// TypeError: (281-289): Public state variable has override specified but does not override anything.

14
test/libsolidity/syntaxTests/inheritance/override/public_vars_multiple_diamond.sol Normal file
View File

@ -0,0 +1,14 @@
contract A {
function foo() external virtual pure returns(uint) { return 5; }
}
contract B is A {
function foo() external virtual override pure returns(uint) { return 5; }
}
contract C is A {
function foo() external virtual override pure returns(uint) { return 5; }
}
contract X is B, C {
uint public override foo;
}
// ----
// TypeError: (271-320): Derived contract must override function "foo". Function with the same name and parameter types defined in two or more base classes.

15
test/libsolidity/syntaxTests/inheritance/override/public_vars_multiple_diamond1.sol Normal file
View File

@ -0,0 +1,15 @@
contract A {
function foo() external virtual pure returns(uint) { return 5; }
}
contract B is A {
uint public override foo;
}
contract C is A {
function foo() external virtual override pure returns(uint) { return 5; }
}
contract X is B, C {
uint public override foo;
}
// ----
// DeclarationError: (245-269): Identifier already declared.
// TypeError: (223-272): Derived contract must override function "foo". Function with the same name and parameter types defined in two or more base classes.

11
test/libsolidity/syntaxTests/inheritance/override/public_vars_multiple_explicit_override.sol Normal file
View File

@ -0,0 +1,11 @@
contract A {
function foo() external virtual pure returns(uint) { return 5; }
}
contract B {
function foo() external virtual pure returns(uint) { return 5; }
}
contract X is A, B {
uint public override(A, B) foo;
}
// ----
// TypeError: (162-217): Derived contract must override function "foo". Function with the same name and parameter types defined in two or more base classes.

5
test/libsolidity/syntaxTests/inheritance/override/public_vars_wrong_override.sol Normal file
View File

@ -0,0 +1,5 @@
contract X {
uint public override foo;
}
// ----
// TypeError: (26-34): Public state variable has override specified but does not override anything.