Merge pull request #5557 from ethereum/fixInterfaceImplementedByPublicStateVariable

Public state variables are implementing external functions.

test/libsolidity/syntaxTests/inheritance/override/implement_interface_by_public_variable.sol

@@ -0,0 +1,7 @@
+interface X { function test() external returns (uint256); }
+contract Y is X {
+    uint256 public test = 42;
+}
+contract T {
+    constructor() public { new Y(); }
+}

test/libsolidity/syntaxTests/inheritance/override/implement_internal_function_by_public_variable.sol

@@ -0,0 +1,9 @@
+contract X { function test() internal returns (uint256); }
+contract Y is X {
+    uint256 public test = 42;
+}
+contract T {
+    constructor() public { new Y(); }
+}
+// ----
+// DeclarationError: (81-105): Identifier already declared.

test/libsolidity/syntaxTests/inheritance/override/implement_private_function_by_public_variable.sol

@@ -0,0 +1,7 @@
+contract X { function test() private returns (uint256); }
+contract Y is X {
+    uint256 public test = 42;
+}
+contract T {
+    constructor() public { new Y(); }
+}

test/libsolidity/syntaxTests/inheritance/override/implement_public_function_by_public_variable.sol

@@ -0,0 +1,9 @@
+contract X { function test() public returns (uint256); }
+contract Y is X {
+    uint256 public test = 42;
+}
+contract T {
+    constructor() public { new Y(); }
+}
+// ----
+// DeclarationError: (79-103): Identifier already declared.

test/libsolidity/syntaxTests/inheritance/override/state_variable_function.sol

@@ -6,3 +6,4 @@ contract C is A {
 }
 // ----
 // DeclarationError: (50-85): Identifier already declared.
+// TypeError: (50-85): Redeclaring an already implemented function as abstract