Merge pull request #4437 from ethereum/report-empty-var-decls

[BREAKING] Report empty var tuple decls

test/libsolidity/syntaxTests/nameAndTypeResolution/239_multi_variable_declaration_wildcards_fine.sol

@@ -13,6 +13,8 @@ contract C {
     }
 }
 // ----
+// SyntaxError: (307-325): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
+// SyntaxError: (335-350): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
 // Warning: (179-198): Different number of components on the left hand side (2) than on the right hand side (3).
 // Warning: (208-233): Different number of components on the left hand side (3) than on the right hand side (2).
 // Warning: (243-262): Different number of components on the left hand side (2) than on the right hand side (3).

test/libsolidity/syntaxTests/nameAndTypeResolution/246_multi_variable_declaration_wildcards_fail_5.sol

@@ -3,4 +3,5 @@ contract C {
     function f() public { var (,) = one(); }
 }
 // ----
+// SyntaxError: (81-96): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
 // TypeError: (81-96): Wildcard both at beginning and end of variable declaration list is only allowed if the number of components is equal.

test/libsolidity/syntaxTests/types/unnamed_tuple_decl.sol

@@ -0,0 +1,19 @@
+pragma solidity ^0.4.20;
+
+contract C {
+    function f() internal pure {}
+    function g() internal pure returns (uint) { return 1; }
+    function h() internal pure returns (uint, uint) { return (1, 2); }
+
+    function test() internal pure {
+        var () = f();
+        var () = g();
+        var (,) = h();
+    }
+}
+
+// ----
+// SyntaxError: (249-261): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
+// SyntaxError: (271-283): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
+// SyntaxError: (293-306): The use of the "var" keyword is disallowed. The declaration part of the statement can be removed, since it is empty.
+// TypeError: (271-283): Too many components (1) in value for variable assignment (0) needed