Merge pull request #13367 from ethereum/invalidTupleAssignment

Fix ICE on invalid tuple assignments.

Author: ekpyron

Changelog.md

@@ -10,6 +10,7 @@ Compiler Features:
 
 
 Bugfixes:
+ * Type Checker: Fix internal compiler error on tuple assignments with invalid left-hand side.
 
 
 ### 0.8.16 (2022-08-08)

libsolidity/analysis/TypeChecker.cpp

@@ -166,8 +166,15 @@ void TypeChecker::checkDoubleStorageAssignment(Assignment const& _assignment)
 						);
 		}
 	};
+
+	TupleExpression const* lhsTupleExpression = dynamic_cast<TupleExpression const*>(&_assignment.leftHandSide());
+	if (!lhsTupleExpression)
+	{
+		solAssert(m_errorReporter.hasErrors());
+		return;
+	}
 	count(
-		dynamic_cast<TupleExpression const&>(_assignment.leftHandSide()),
+		*lhsTupleExpression,
 		dynamic_cast<TupleType const&>(*type(_assignment.rightHandSide())),
 		count
 	);

test/libsolidity/syntaxTests/tupleAssignments/tuple_to_function_assignment.sol

@@ -0,0 +1,17 @@
+contract C {
+	function f() internal pure {}
+	function g() internal pure returns (uint256) {}
+	function h() internal pure returns (uint256, uint256) {}
+	function test() public pure {
+		f() = ();
+		g() = (uint256(1));
+		h() = (uint256(1), uint256(2));
+		h() = ();
+	}
+}
+// ----
+// TypeError 4247: (184-187): Expression has to be an lvalue.
+// TypeError 4247: (196-199): Expression has to be an lvalue.
+// TypeError 4247: (218-221): Expression has to be an lvalue.
+// TypeError 4247: (252-255): Expression has to be an lvalue.
+// TypeError 7407: (258-260): Type tuple() is not implicitly convertible to expected type tuple(uint256,uint256).