Merge pull request #4375 from ethereum/fallbackExternalBackwardsCompatible

Fallback function has to be external: backwards-compatible changes.

docs/contracts.rst

@@ -543,7 +543,7 @@ Fallback Function
 =================
 
 A contract can have exactly one unnamed function. This function cannot have
-arguments and cannot return anything.
+arguments, cannot return anything and has to have ``external`` visibility.
 It is executed on a call to the contract if none of the other
 functions match the given function identifier (or if no data was supplied at
 all).
@@ -591,7 +591,7 @@ Like any function, the fallback function can execute complex operations as long
         // Sending Ether to this contract will cause an exception,
         // because the fallback function does not have the `payable`
         // modifier.
-        function() public { x = 1; }
+        function() external { x = 1; }
         uint x;
     }
 
@@ -599,7 +599,7 @@ Like any function, the fallback function can execute complex operations as long
     // This contract keeps all Ether sent to it with no way
     // to get it back.
     contract Sink {
-        function() public payable { }
+        function() external payable { }
     }
 
     contract Caller {

docs/security-considerations.rst

@@ -213,7 +213,7 @@ Now someone tricks you into sending ether to the address of this attack wallet:
             owner = msg.sender;
         }
 
-        function() public {
+        function() external {
             TxUserWallet(msg.sender).transferTo(owner, msg.sender.balance);
         }
     }

docs/style-guide.rst

@@ -278,7 +278,7 @@ Yes::
             ...
         }
 
-        function() public {
+        function() external {
             ...
         }
 
@@ -308,6 +308,10 @@ No::
         // External functions
         // ...
 
+        function() external {
+            ...
+        }
+
         // Private functions
         // ...
 
@@ -318,10 +322,6 @@ No::
             ...
         }
 
-        function() public {
-            ...
-        }
-
         // Internal functions
         // ...
     }
@@ -374,13 +374,13 @@ Don't include a whitespace in the fallback function:
 
 Yes::
 
-    function() public {
+    function() external {
         ...
     }
 
 No::
 
-    function () public {
+    function () external {
         ...
     }
 

test/compilationTests/MultiSigWallet/MultiSigWallet.sol

@@ -90,6 +90,7 @@ contract MultiSigWallet {
 
     /// @dev Fallback function allows to deposit ether.
     function()
+        external
         payable
     {
         if (msg.value > 0)

test/compilationTests/corion/ico.sol

@@ -275,7 +275,7 @@ contract ico is safeMath {
         require( msg.sender.send(_val) );
     }
     
-    function () payable {
+    function () external payable {
         /*
             Callback function. Simply calls the buy function as a beneficiary and there is no affilate address.
             If they call the contract without any function then this process will be taken place.

test/compilationTests/zeppelin/Bounty.sol

@@ -18,7 +18,7 @@ contract Bounty is PullPayment, Destructible {
   /**
    * @dev Fallback function allowing the contract to recieve funds, if they haven't already been claimed.
    */
-  function() payable {
+  function() external payable {
     if (claimed) {
       throw;
     }

test/compilationTests/zeppelin/MultisigWallet.sol

@@ -39,7 +39,7 @@ contract MultisigWallet is Multisig, Shareable, DayLimit {
   /** 
    * @dev Fallback function, receives value and emits a deposit event. 
    */
-  function() payable {
+  function() external payable {
     // just being sent some cash?
     if (msg.value > 0)
       emit Deposit(msg.sender, msg.value);

test/compilationTests/zeppelin/crowdsale/Crowdsale.sol

@@ -61,7 +61,7 @@ contract Crowdsale {
 
 
   // fallback function can be used to buy tokens
-  function () payable {
+  function () external payable {
     buyTokens(msg.sender);
   }
 

test/contracts/Wallet.cpp

@@ -379,7 +379,7 @@ contract Wallet is multisig, multiowned, daylimit {
 	}
 
 	// gets called when no other function matches
-	function() payable {
+	function() external payable {
 		// just being sent some cash?
 		if (msg.value > 0)
 			emit Deposit(msg.sender, msg.value);

test/libsolidity/GasMeter.cpp

@@ -301,7 +301,7 @@ BOOST_AUTO_TEST_CASE(regular_functions_exclude_fallback)
 	char const* sourceCode = R"(
 		contract A {
 			uint public x;
-			function() { x = 2; }
+			function() external { x = 2; }
 		}
 	)";
 	testCreationTimeGas(sourceCode);

test/libsolidity/Imports.cpp

@@ -109,7 +109,7 @@ BOOST_AUTO_TEST_CASE(simple_alias)
 {
 	CompilerStack c;
 	c.addSource("a", "contract A {} pragma solidity >=0.0;");
-	c.addSource("dir/a/b/c", "import \"../../.././a\" as x; contract B is x.A { function() { x.A r = x.A(20); } } pragma solidity >=0.0;");
+	c.addSource("dir/a/b/c", "import \"../../.././a\" as x; contract B is x.A { function() external { x.A r = x.A(20); } } pragma solidity >=0.0;");
 	c.setEVMVersion(dev::test::Options::get().evmVersion());
 	BOOST_CHECK(c.compile());
 }

test/libsolidity/SolidityABIJSON.cpp

@@ -843,7 +843,7 @@ BOOST_AUTO_TEST_CASE(include_fallback_function)
 {
 	char const* sourceCode = R"(
 		contract test {
-			function() {}
+			function() external {}
 		}
 	)";
 
@@ -897,7 +897,7 @@ BOOST_AUTO_TEST_CASE(payable_fallback_function)
 {
 	char const* sourceCode = R"(
 		contract test {
-			function () payable {}
+			function () external payable {}
 		}
 	)";
 

test/libsolidity/SolidityEndToEndTest.cpp

@@ -1812,7 +1812,7 @@ BOOST_AUTO_TEST_CASE(transfer_ether)
 		}
 
 		contract C {
-			function () payable {
+			function () external payable {
 				throw;
 			}
 		}
@@ -2506,7 +2506,7 @@ BOOST_AUTO_TEST_CASE(contracts_as_addresses)
 {
 	char const* sourceCode = R"(
 		contract helper {
-			function() payable { } // can receive ether
+			function() external payable { } // can receive ether
 		}
 		contract test {
 			helper h;
@@ -3054,7 +3054,7 @@ BOOST_AUTO_TEST_CASE(fallback_function)
 	char const* sourceCode = R"(
 		contract A {
 			uint data;
-			function() { data = 1; }
+			function() external { data = 1; }
 			function getData() returns (uint r) { return data; }
 		}
 	)";
@@ -3069,7 +3069,7 @@ BOOST_AUTO_TEST_CASE(inherited_fallback_function)
 	char const* sourceCode = R"(
 		contract A {
 			uint data;
-			function() { data = 1; }
+			function() external { data = 1; }
 			function getData() returns (uint r) { return data; }
 		}
 		contract B is A {}
@@ -3100,7 +3100,7 @@ BOOST_AUTO_TEST_CASE(short_data_calls_fallback)
 			uint public x;
 			// Signature is d88e0b00
 			function fow() { x = 3; }
-			function () { x = 2; }
+			function () external { x = 2; }
 		}
 	)";
 	compileAndRun(sourceCode);
@@ -3802,11 +3802,11 @@ BOOST_AUTO_TEST_CASE(call_forward_bytes)
 		contract receiver {
 			uint public received;
 			function receive(uint x) { received += x + 1; }
-			function() { received = 0x80; }
+			function() external { received = 0x80; }
 		}
 		contract sender {
 			function sender() { rec = new receiver(); }
-			function() { savedData = msg.data; }
+			function() external { savedData = msg.data; }
 			function forward() returns (bool) { !rec.call(savedData); return true; }
 			function clear() returns (bool) { delete savedData; return true; }
 			function val() returns (uint) { return rec.received(); }
@@ -3830,7 +3830,7 @@ BOOST_AUTO_TEST_CASE(call_forward_bytes_length)
 	char const* sourceCode = R"(
 		contract receiver {
 			uint public calledLength;
-			function() { calledLength = msg.data.length; }
+			function() external { calledLength = msg.data.length; }
 		}
 		contract sender {
 			receiver rec;
@@ -3872,11 +3872,11 @@ BOOST_AUTO_TEST_CASE(copying_bytes_multiassign)
 		contract receiver {
 			uint public received;
 			function receive(uint x) { received += x + 1; }
-			function() { received = 0x80; }
+			function() external { received = 0x80; }
 		}
 		contract sender {
 			function sender() { rec = new receiver(); }
-			function() { savedData1 = savedData2 = msg.data; }
+			function() external { savedData1 = savedData2 = msg.data; }
 			function forward(bool selector) returns (bool) {
 				if (selector) { rec.call(savedData1); delete savedData1; }
 				else { rec.call(savedData2); delete savedData2; }
@@ -3903,7 +3903,7 @@ BOOST_AUTO_TEST_CASE(delete_removes_bytes_data)
 {
 	char const* sourceCode = R"(
 		contract c {
-			function() { data = msg.data; }
+			function() external { data = msg.data; }
 			function del() returns (bool) { delete data; return true; }
 			bytes data;
 		}
@@ -3920,7 +3920,7 @@ BOOST_AUTO_TEST_CASE(copy_from_calldata_removes_bytes_data)
 	char const* sourceCode = R"(
 		contract c {
 			function set() returns (bool) { data = msg.data; return true; }
-			function() { data = msg.data; }
+			function() external { data = msg.data; }
 			bytes data;
 		}
 	)";
@@ -6265,7 +6265,7 @@ BOOST_AUTO_TEST_CASE(failing_send)
 	char const* sourceCode = R"(
 		contract Helper {
 			uint[] data;
-			function () {
+			function () external {
 				data[9]; // trigger exception
 			}
 		}
@@ -6289,7 +6289,7 @@ BOOST_AUTO_TEST_CASE(send_zero_ether)
 	// (it previously did not because the gas stipend was not provided by the EVM)
 	char const* sourceCode = R"(
 		contract Receiver {
-			function () payable {
+			function () external payable {
 			}
 		}
 		contract Main {
@@ -7805,7 +7805,7 @@ BOOST_AUTO_TEST_CASE(reject_ether_sent_to_library)
 			function f(address x) returns (bool) {
 				return x.send(1);
 			}
-			function () payable {}
+			function () external payable {}
 		}
 	)";
 	compileAndRun(sourceCode, 0, "lib");
@@ -9335,7 +9335,7 @@ BOOST_AUTO_TEST_CASE(mutex)
 				else
 					return fund.withdrawUnprotected(10);
 			}
-			function() payable {
+			function() external payable {
 				callDepth++;
 				if (callDepth < 4)
 					attackInternal();
@@ -9461,7 +9461,7 @@ BOOST_AUTO_TEST_CASE(payable_function)
 			function f() payable returns (uint) {
 				return msg.value;
 			}
-			function() payable {
+			function() external payable {
 				a = msg.value + 1;
 			}
 		}
@@ -9500,7 +9500,7 @@ BOOST_AUTO_TEST_CASE(non_payable_throw)
 			function f() returns (uint) {
 				return msg.value;
 			}
-			function() {
+			function() external {
 				a = msg.value + 1;
 			}
 		}
@@ -11189,7 +11189,7 @@ BOOST_AUTO_TEST_CASE(bubble_up_error_messages_through_transfer)
 {
 	char const* sourceCode = R"(
 		contract D {
-			function() public payable {
+			function() external payable {
 				revert("message");
 			}
 			function f() public {
@@ -11340,7 +11340,7 @@ BOOST_AUTO_TEST_CASE(interface_contract)
 		interface I {
 			event A();
 			function f() returns (bool);
-			function() payable;
+			function() external payable;
 		}
 
 		contract A is I {
@@ -11352,7 +11352,7 @@ BOOST_AUTO_TEST_CASE(interface_contract)
 				return true;
 			}
 
-			function() payable {
+			function() external payable {
 			}
 		}
 

test/libsolidity/syntaxTests/fallback/default_visibility.sol

@@ -0,0 +1,6 @@
+contract C {
+    // Check that visibility is also enforced for the fallback function.
+    function() {}
+}
+// ----
+// Warning: (90-103): No visibility specified. Defaulting to "public". 

test/libsolidity/syntaxTests/fallback/pure_modifier.sol

@@ -1,6 +1,6 @@
 contract C {
     uint x;
-    function() pure { x = 2; }
+    function() external pure { x = 2; }
 }
 // ----
-// TypeError: (29-55): Fallback function must be payable or non-payable, but is "pure".
+// TypeError: (29-64): Fallback function must be payable or non-payable, but is "pure".

test/libsolidity/syntaxTests/fallback/view_modifier.sol

@@ -1,6 +1,6 @@
 contract C {
     uint x;
-    function() view { x = 2; }
+    function() external view { x = 2; }
 }
 // ----
-// TypeError: (29-55): Fallback function must be payable or non-payable, but is "view".
+// TypeError: (29-64): Fallback function must be payable or non-payable, but is "view".

test/libsolidity/syntaxTests/nameAndTypeResolution/074_fallback_function.sol

@@ -1,4 +1,4 @@
 contract C {
     uint x;
-    function() public { x = 2; }
+    function() external { x = 2; }
 }

test/libsolidity/syntaxTests/nameAndTypeResolution/075_fallback_function_with_arguments.sol

@@ -1,6 +1,6 @@
 contract C {
     uint x;
-    function(uint a) public { x = 2; }
+    function(uint a) external { x = 2; }
 }
 // ----
 // TypeError: (37-45): Fallback function cannot take parameters.

test/libsolidity/syntaxTests/nameAndTypeResolution/076_fallback_function_in_library.sol

@@ -1,5 +1,5 @@
 library C {
-    function() public {}
+    function() external {}
 }
 // ----
-// TypeError: (16-36): Libraries cannot have fallback functions.
+// TypeError: (16-38): Libraries cannot have fallback functions.

test/libsolidity/syntaxTests/nameAndTypeResolution/077_fallback_function_with_return_parameters.sol

@@ -1,5 +1,5 @@
 contract C {
-    function() public returns (uint) { }
+    function() external returns (uint) { }
 }
 // ----
-// TypeError: (43-49): Fallback function cannot return values.
+// TypeError: (45-51): Fallback function cannot return values.

test/libsolidity/syntaxTests/nameAndTypeResolution/078_fallback_function_twice.sol

@@ -1,7 +1,7 @@
 contract C {
     uint x;
-    function() public { x = 2; }
-    function() public { x = 3; }
+    function() external { x = 2; }
+    function() external { x = 3; }
 }
 // ----
-// DeclarationError: (62-90): Only one fallback function is allowed.
+// DeclarationError: (64-94): Only one fallback function is allowed.

test/libsolidity/syntaxTests/nameAndTypeResolution/079_fallback_function_inheritance.sol

@@ -1,7 +1,7 @@
 contract A {
     uint x;
-    function() public { x = 1; }
+    function() external { x = 1; }
 }
 contract C is A {
-    function() public { x = 2; }
+    function() external { x = 2; }
 }

test/libsolidity/syntaxTests/nameAndTypeResolution/196_integer_boolean_or.sol

@@ -1,3 +1,3 @@
-contract test { function() public { uint x = 1; uint y = 2; x || y; } }
+contract test { function() external { uint x = 1; uint y = 2; x || y; } }
 // ----
-// TypeError: (60-66): Operator || not compatible with types uint256 and uint256
+// TypeError: (62-68): Operator || not compatible with types uint256 and uint256

test/libsolidity/syntaxTests/nameAndTypeResolution/197_integer_boolean_and.sol

@@ -1,3 +1,3 @@
-contract test { function() public { uint x = 1; uint y = 2; x && y; } }
+contract test { function() external { uint x = 1; uint y = 2; x && y; } }
 // ----
-// TypeError: (60-66): Operator && not compatible with types uint256 and uint256
+// TypeError: (62-68): Operator && not compatible with types uint256 and uint256

test/libsolidity/syntaxTests/nameAndTypeResolution/198_integer_boolean_not.sol

@@ -1,3 +1,3 @@
-contract test { function() public { uint x = 1; !x; } }
+contract test { function() external { uint x = 1; !x; } }
 // ----
-// TypeError: (48-50): Unary operator ! cannot be applied to type uint256
+// TypeError: (50-52): Unary operator ! cannot be applied to type uint256

test/libsolidity/syntaxTests/nameAndTypeResolution/199_integer_unsigned_exp_signed.sol

@@ -1,3 +1,3 @@
-contract test { function() public { uint x = 3; int y = -4; x ** y; } }
+contract test { function() external { uint x = 3; int y = -4; x ** y; } }
 // ----
-// TypeError: (60-66): Operator ** not compatible with types uint256 and int256
+// TypeError: (62-68): Operator ** not compatible with types uint256 and int256

test/libsolidity/syntaxTests/nameAndTypeResolution/200_integer_signed_exp_unsigned.sol

@@ -1,3 +1,3 @@
-contract test { function() public { uint x = 3; int y = -4; y ** x; } }
+contract test { function() external { uint x = 3; int y = -4; y ** x; } }
 // ----
-// TypeError: (60-66): Operator ** not compatible with types int256 and uint256
+// TypeError: (62-68): Operator ** not compatible with types int256 and uint256

test/libsolidity/syntaxTests/nameAndTypeResolution/201_integer_signed_exp_signed.sol

@@ -1,3 +1,3 @@
-contract test { function() public { int x = -3; int y = -4; x ** y; } }
+contract test { function() external { int x = -3; int y = -4; x ** y; } }
 // ----
-// TypeError: (60-66): Operator ** not compatible with types int256 and int256
+// TypeError: (62-68): Operator ** not compatible with types int256 and int256

test/libsolidity/syntaxTests/nameAndTypeResolution/202_bytes_reference_compare_operators.sol

@@ -1,3 +1,3 @@
-contract test { bytes a; bytes b; function() public { a == b; } }
+contract test { bytes a; bytes b; function() external { a == b; } }
 // ----
-// TypeError: (54-60): Operator == not compatible with types bytes storage ref and bytes storage ref
+// TypeError: (56-62): Operator == not compatible with types bytes storage ref and bytes storage ref

test/libsolidity/syntaxTests/nameAndTypeResolution/203_struct_reference_compare_operators.sol

@@ -1,3 +1,10 @@
-contract test { struct s {uint a;} s x; s y; function() public { x == y; } }
+contract test {
+  struct s {uint a;}
+  s x;
+  s y;
+  function() external {
+    x == y;
+  }
+}
 // ----
-// TypeError: (65-71): Operator == not compatible with types struct test.s storage ref and struct test.s storage ref
+// TypeError: (79-85): Operator == not compatible with types struct test.s storage ref and struct test.s storage ref

test/libsolidity/syntaxTests/nameAndTypeResolution/415_interface_functions.sol

@@ -1,9 +1,5 @@
 interface I {
-    function();
-    function f();
+    function() external;
+    function f() external;
 }
 // ----
-// Warning: (18-29): Functions in interfaces should be declared external.
-// Warning: (34-47): Functions in interfaces should be declared external.
-// Warning: (18-29): No visibility specified. Defaulting to "public". In interfaces it defaults to external.
-// Warning: (34-47): No visibility specified. Defaulting to "public". In interfaces it defaults to external.

test/libsolidity/syntaxTests/nameAndTypeResolution/424_using_interface_complex.sol

@@ -1,17 +1,11 @@
 interface I {
     event A();
-    function f();
-    function g();
-    function();
+    function f() external;
+    function g() external;
+    function() external;
 }
 contract C is I {
     function f() public {
     }
 }
 // ----
-// Warning: (33-46): Functions in interfaces should be declared external.
-// Warning: (51-64): Functions in interfaces should be declared external.
-// Warning: (69-80): Functions in interfaces should be declared external.
-// Warning: (33-46): No visibility specified. Defaulting to "public". In interfaces it defaults to external.
-// Warning: (51-64): No visibility specified. Defaulting to "public". In interfaces it defaults to external.
-// Warning: (69-80): No visibility specified. Defaulting to "public". In interfaces it defaults to external.

test/libsolidity/syntaxTests/nameAndTypeResolution/463_error_transfer_non_payable_fallback.sol

@@ -2,16 +2,16 @@
 // because A's fallback function is not payable.
 
 contract A {
-    function() public {}
+    function() external {}
 }
 
 contract B {
     A a;
 
-    function() public {
+    function() external {
         a.transfer(100);
     }
 }
 // ----
-// Warning: (209-219): Using contract member "transfer" inherited from the address type is deprecated. Convert the contract to "address" type to access the member, for example use "address(contract).transfer" instead.
-// TypeError: (209-219): Value transfer to a contract without a payable fallback function.
+// Warning: (213-223): Using contract member "transfer" inherited from the address type is deprecated. Convert the contract to "address" type to access the member, for example use "address(contract).transfer" instead.
+// TypeError: (213-223): Value transfer to a contract without a payable fallback function.

test/libsolidity/syntaxTests/nameAndTypeResolution/464_error_transfer_no_fallback.sol

@@ -6,10 +6,10 @@ contract A {}
 contract B {
     A a;
 
-    function() public {
+    function() external {
         a.transfer(100);
     }
 }
 // ----
-// Warning: (190-200): Using contract member "transfer" inherited from the address type is deprecated. Convert the contract to "address" type to access the member, for example use "address(contract).transfer" instead.
-// TypeError: (190-200): Value transfer to a contract without a payable fallback function.
+// Warning: (192-202): Using contract member "transfer" inherited from the address type is deprecated. Convert the contract to "address" type to access the member, for example use "address(contract).transfer" instead.
+// TypeError: (192-202): Value transfer to a contract without a payable fallback function.

test/libsolidity/syntaxTests/nameAndTypeResolution/465_error_send_non_payable_fallback.sol

@@ -2,16 +2,16 @@
 // because A does not have a payable fallback function.
 
 contract A {
-    function() public {}
+    function() external {}
 }
 
 contract B {
     A a;
 
-    function() public {
+    function() external {
         require(a.send(100));
     }
 }
 // ----
-// Warning: (220-226): Using contract member "send" inherited from the address type is deprecated. Convert the contract to "address" type to access the member, for example use "address(contract).send" instead.
-// TypeError: (220-226): Value transfer to a contract without a payable fallback function.
+// Warning: (224-230): Using contract member "send" inherited from the address type is deprecated. Convert the contract to "address" type to access the member, for example use "address(contract).send" instead.
+// TypeError: (224-230): Value transfer to a contract without a payable fallback function.

test/libsolidity/syntaxTests/nameAndTypeResolution/466_does_not_error_transfer_payable_fallback.sol

@@ -2,15 +2,15 @@
 // because A does not have a payable fallback function.
 
 contract A {
-    function() payable public {}
+    function() payable external {}
 }
 
 contract B {
     A a;
 
-    function() public {
+    function() external {
         a.transfer(100);
     }
 }
 // ----
-// Warning: (224-234): Using contract member "transfer" inherited from the address type is deprecated. Convert the contract to "address" type to access the member, for example use "address(contract).transfer" instead.
+// Warning: (228-238): Using contract member "transfer" inherited from the address type is deprecated. Convert the contract to "address" type to access the member, for example use "address(contract).transfer" instead.

test/libsolidity/syntaxTests/nameAndTypeResolution/467_does_not_error_transfer_regular_function.sol

@@ -5,7 +5,7 @@ contract A {
 contract B {
     A a;
 
-    function() public {
+    function() external {
         a.transfer();
     }
 }

test/libsolidity/syntaxTests/nameAndTypeResolution/526_fallback_marked_external.sol

@@ -0,0 +1,3 @@
+contract C {
+    function () external { }
+}

test/libsolidity/syntaxTests/nameAndTypeResolution/527_fallback_marked_internal.sol

@@ -0,0 +1,4 @@
+contract C {
+    function () internal { }
+}
+// ----

test/libsolidity/syntaxTests/nameAndTypeResolution/528_fallback_marked_private.sol

@@ -0,0 +1,4 @@
+contract C {
+    function () private { }
+}
+// ----

test/libsolidity/syntaxTests/nameAndTypeResolution/529_fallback_marked_public.sol

@@ -0,0 +1,4 @@
+contract C {
+    function () public { }
+}
+// ----

test/libsolidity/syntaxTests/parsing/fallback_function.sol

@@ -1,5 +1,4 @@
 contract c {
-    function() { }
+    function() external { }
 }
 // ----
-// Warning: (17-31): No visibility specified. Defaulting to "public". 

test/libsolidity/syntaxTests/viewPureChecker/builtin_functions.sol

@@ -14,5 +14,5 @@ contract C {
         assert(true);
         x; y; z;
     }
-    function() payable public {}
+    function() payable external {}
 }