Merge pull request #4376 from ethereum/fallbackExternal

Fallback functions have to be external

Changelog.md

@@ -3,6 +3,7 @@
 How to update your code:
  * Change every ``.call()`` to a ``.call("")`` and every ``.call(signature, a, b, c)`` to use ``.call(abi.encodeWithSignature(signature, a, b, c))`` (the last one only works for value types).
  * Change every ``keccak256(a, b, c)`` to ``keccak256(abi.encodePacked(a, b, c))``.
+ * Make your fallback functions ``external``.
 
 
 Breaking Changes:
@@ -37,6 +38,7 @@ Breaking Changes:
  * Type Checker: Disallow specifying base constructor arguments multiple times in the same inheritance hierarchy. This was already the case in the experimental 0.5.0 mode.
  * Type Checker: Disallow uninitialized storage variables. This was already the case in the experimental 0.5.0 mode.
  * Type Checker: Only accept a single ``bytes`` type for ``.call()`` (and family), ``keccak256()``, ``sha256()`` and ``ripemd160()``.
+ * Type Checker: Fallback function must be external. This was already the case in the experimental 0.5.0 mode.
  * Remove obsolete ``std`` directory from the Solidity repository. This means accessing ``https://github.com/ethereum/soldity/blob/develop/std/*.sol`` (or ``https://github.com/ethereum/solidity/std/*.sol`` in Remix) will not be possible.
  * Syntax Checker: Named return values in function types are an error.
  * Syntax Checker: Disallow unary ``+``. This was already the case in the experimental 0.5.0 mode.

libsolidity/analysis/TypeChecker.cpp

@@ -123,10 +123,7 @@ bool TypeChecker::visit(ContractDefinition const& _contract)
 				m_errorReporter.typeError(function->parameterList().location(), "Fallback function cannot take parameters.");
 			if (!function->returnParameters().empty())
 				m_errorReporter.typeError(function->returnParameterList()->location(), "Fallback function cannot return values.");
-			if (
-				_contract.sourceUnit().annotation().experimentalFeatures.count(ExperimentalFeature::V050) &&
-				function->visibility() != FunctionDefinition::Visibility::External
-			)
+			if (function->visibility() != FunctionDefinition::Visibility::External)
 				m_errorReporter.typeError(function->location(), "Fallback function must be defined as \"external\".");
 		}
 

test/libsolidity/syntaxTests/fallback/default_visibility.sol

@@ -3,4 +3,4 @@ contract C {
     function() {}
 }
 // ----
-// Warning: (90-103): No visibility specified. Defaulting to "public".
+// TypeError: (90-103): Fallback function must be defined as "external".

test/libsolidity/syntaxTests/inlineAssembly/storage_reference.sol

@@ -1,6 +1,6 @@
 contract C {
     uint[] x;
-    function() public { 
+    function() external { 
         uint[] storage y = x;
         assembly {
             pop(y)
@@ -8,4 +8,4 @@ contract C {
     }
 }
 // ----
-// TypeError: (117-118): You have to use the _slot or _offset suffix to access storage reference variables.
+// TypeError: (119-120): You have to use the _slot or _offset suffix to access storage reference variables.

test/libsolidity/syntaxTests/inlineAssembly/storage_reference_fine.sol

@@ -1,6 +1,6 @@
 contract C {
     uint[] x;
-    function() public { 
+    function() external { 
         uint[] storage y = x;
         assembly {
             pop(y_slot)

test/libsolidity/syntaxTests/nameAndTypeResolution/526_fallback_marked_external_v050.sol

@@ -1,4 +0,0 @@
-pragma experimental "v0.5.0";
-contract C {
-    function () external { }
-}

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

@@ -2,3 +2,4 @@ contract C {
     function () internal { }
 }
 // ----
+// TypeError: (17-41): Fallback function must be defined as "external".

test/libsolidity/syntaxTests/nameAndTypeResolution/527_fallback_marked_internal_v050.sol

@@ -1,6 +0,0 @@
-pragma experimental "v0.5.0";
-contract C {
-    function () internal { }
-}
-// ----
-// TypeError: (47-71): Fallback function must be defined as "external".

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

@@ -2,3 +2,4 @@ contract C {
     function () private { }
 }
 // ----
+// TypeError: (17-40): Fallback function must be defined as "external".

test/libsolidity/syntaxTests/nameAndTypeResolution/528_fallback_marked_private_v050.sol

@@ -1,6 +0,0 @@
-pragma experimental "v0.5.0";
-contract C {
-    function () private { }
-}
-// ----
-// TypeError: (47-70): Fallback function must be defined as "external".

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

@@ -2,3 +2,4 @@ contract C {
     function () public { }
 }
 // ----
+// TypeError: (17-39): Fallback function must be defined as "external".

test/libsolidity/syntaxTests/nameAndTypeResolution/529_fallback_marked_public_v050.sol

@@ -1,6 +0,0 @@
-pragma experimental "v0.5.0";
-contract C {
-    function () public { }
-}
-// ----
-// TypeError: (47-69): Fallback function must be defined as "external".