[SMTChecker] Support enums

test/libsolidity/smtCheckerTests/special/msg_data.sol

@@ -8,5 +8,4 @@ contract C
 }
 // ----
 // Warning: (86-101): Assertion checker does not yet support this expression.
-// Warning: (86-101): Internal error: Expression undefined for SMT solver.
 // Warning: (79-106): Assertion violation happens here

test/libsolidity/smtCheckerTests/typecast/enum_from_uint.sol

@@ -0,0 +1,14 @@
+pragma experimental SMTChecker;
+
+contract C
+{
+	enum D { Left, Right }
+	function f(uint x) public pure {
+		require(x == 0);
+		D _a = D(x);
+		assert(_a == D.Left);
+	}
+}
+// ----
+// Warning: (132-136): Type conversion is not yet fully supported and might yield false positives.
+// Warning: (140-160): Assertion violation happens here

test/libsolidity/smtCheckerTests/typecast/enum_to_uint_max_value.sol

@@ -0,0 +1,12 @@
+pragma experimental SMTChecker;
+
+contract C
+{
+	enum D { Left, Right }
+	function f(D _a) public pure {
+		uint x = uint(_a);
+		assert(x < 10);
+	}
+}
+// ----
+// Warning: (113-121): Type conversion is not yet fully supported and might yield false positives.

test/libsolidity/smtCheckerTests/types/enum_explicit_values.sol

@@ -0,0 +1,12 @@
+pragma experimental SMTChecker;
+
+contract C
+{
+	enum D { Left, Right }
+	D d;
+	function f(D _a) public {
+		require(_a == D.Left);
+		d = D.Right;
+		assert(d != _a);
+	}
+}

test/libsolidity/smtCheckerTests/types/enum_explicit_values_2.sol

@@ -0,0 +1,14 @@
+pragma experimental SMTChecker;
+
+contract C
+{
+	enum D { Left, Right }
+	D d;
+	function f(D _a) public {
+		require(_a == D.Left);
+		d = D.Left;
+		assert(d != _a);
+	}
+}
+// ----
+// Warning: (144-159): Assertion violation happens here

test/libsolidity/smtCheckerTests/types/enum_in_library.sol

@@ -0,0 +1,15 @@
+pragma experimental SMTChecker;
+
+library L
+{
+	enum D { Left, Right }
+}
+
+contract C
+{
+	enum E { Left, Right }
+	function f(E _d) internal pure {
+		_d = E.Left;
+		assert(_d == E.Left);
+	}
+}

test/libsolidity/smtCheckerTests/types/enum_in_library_2.sol

@@ -0,0 +1,17 @@
+pragma experimental SMTChecker;
+
+library L
+{
+	enum D { Left, Right }
+}
+
+contract C
+{
+	enum E { Left, Right }
+	function f(E _d) internal pure {
+		_d = E.Right;
+		assert(_d == E.Left);
+	}
+}
+// ----
+// Warning: (161-181): Assertion violation happens here

test/libsolidity/smtCheckerTests/types/enum_in_struct.sol

@@ -0,0 +1,17 @@
+pragma experimental SMTChecker;
+
+contract C
+{
+	enum D { Left, Right }
+	struct S { uint x; D d; }
+	function f(S memory s) internal pure {
+		s.d = D.Left;
+		assert(s.d == D.Left);
+	}
+}
+// ----
+// Warning: (109-119): Assertion checker does not yet support the type of this variable.
+// Warning: (139-142): Assertion checker does not yet support this expression.
+// Warning: (139-151): Assertion checker does not yet implement such assignments.
+// Warning: (162-165): Assertion checker does not yet support this expression.
+// Warning: (155-176): Assertion violation happens here

test/libsolidity/smtCheckerTests/types/enum_storage_eq.sol

@@ -0,0 +1,13 @@
+pragma experimental SMTChecker;
+
+contract C
+{
+	enum D { Left, Right }
+	D d;
+	function f(D _d) public {
+		d = _d;
+		assert(d != _d);
+	}
+}
+// ----
+// Warning: (115-130): Assertion violation happens here

test/libsolidity/smtCheckerTests/types/enum_transitivity.sol

@@ -0,0 +1,12 @@
+pragma experimental SMTChecker;
+
+contract C
+{
+	enum D { Left, Right }
+	D d;
+	function f(D _a, D _b) public view {
+		require(_a == _b);
+		require(_a == d);
+		assert(d == _b);
+	}
+}

test/libsolidity/smtCheckerTests/types/string_1.sol

@@ -9,6 +9,4 @@ contract C
 // ----
 // Warning: (117-133): Assertion checker does not yet support this expression.
 // Warning: (137-153): Assertion checker does not yet support this expression.
-// Warning: (117-133): Internal error: Expression undefined for SMT solver.
-// Warning: (137-153): Internal error: Expression undefined for SMT solver.
 // Warning: (110-154): Assertion violation happens here