Merge pull request #13754 from ethereum/smt_fix_assignment

Fix internal error in assignment chains

test/libsolidity/smtCheckerTests/operators/assignment_chain_tuple_contract_1.sol

@@ -0,0 +1,10 @@
+contract C {
+    string public name = (C).name = type(C).name;
+
+    function f() external view {
+        assert(keccak256(bytes(name)) == keccak256(bytes("C"))); // should fail because SMTChecker doesn't support type(C).name
+    }
+}
+// ----
+// Warning 7507: (49-61): Assertion checker does not yet support this expression.
+// Warning 6328: (105-160): CHC: Assertion violation happens here.\nCounterexample:\n\n\nTransaction trace:\nC.constructor()\nC.f()

test/libsolidity/smtCheckerTests/operators/assignment_chain_tuple_contract_2.sol

@@ -0,0 +1,13 @@
+contract C {
+    uint x = ((((C)))).x = ((C)).x = 2;
+
+    function f() external view {
+        assert(x == 2); // should hold
+    }
+
+    function g() external view {
+        assert(x != 2); // should fail
+    }
+}
+// ----
+// Warning 6328: (174-188): CHC: Assertion violation happens here.\nCounterexample:\nx = 2\n\nTransaction trace:\nC.constructor()\nState: x = 2\nC.g()

test/libsolidity/smtCheckerTests/operators/assignment_chain_tuple_contract_3.sol

@@ -0,0 +1,22 @@
+contract C {
+    uint x = ((((C)))).x = ((C)).x = 2;
+
+    function f() external view {
+        assert(x == 2); // should fail for D
+    }
+
+    function g() external view {
+        assert(x != 2); // should fail for C
+    }
+}
+
+contract D is C {
+    uint y = ((C)).x = 3;
+
+    function h() external view {
+        assert(y == 3); // should hold
+    }
+}
+// ----
+// Warning 6328: (95-109): CHC: Assertion violation happens here.\nCounterexample:\ny = 3, x = 3\n\nTransaction trace:\nD.constructor()\nState: y = 3, x = 3\nC.f()
+// Warning 6328: (180-194): CHC: Assertion violation happens here.\nCounterexample:\nx = 2\n\nTransaction trace:\nC.constructor()\nState: x = 2\nC.g()