Make literals an error for tight packing (experimental 0.5.0)

Changelog.md

@@ -2,7 +2,7 @@
 
 Features:
  * Optimizer: Remove unnecessary masking of the result of known short instructions (``ADDRESS``, ``CALLER``, ``ORIGIN`` and ``COINBASE``).
-
+ * Type Checker: Make literals (without explicit type casting) an error for tight packing as experimental 0.5.0 feature.
 
 Bugfixes:
 

libsolidity/analysis/TypeChecker.cpp

@@ -1648,6 +1648,8 @@ bool TypeChecker::visit(FunctionCall const& _functionCall)
 	else
 		_functionCall.annotation().type = make_shared<TupleType>(returnTypes);
 
+	bool const v050 = m_scope->sourceUnit().annotation().experimentalFeatures.count(ExperimentalFeature::V050);
+
 	if (auto functionName = dynamic_cast<Identifier const*>(&_functionCall.expression()))
 	{
 		if (functionName->name() == "sha3" && functionType->kind() == FunctionType::Kind::SHA3)
@@ -1674,14 +1676,22 @@ bool TypeChecker::visit(FunctionCall const& _functionCall)
 			{
 				/* If no mobile type is available an error will be raised elsewhere. */
 				if (literal->mobileType())
-					m_errorReporter.warning(
-						arguments[i]->location(),
-						"The type of \"" +
-						argType->toString() +
-						"\" was inferred as " +
-						literal->mobileType()->toString() +
-						". This is probably not desired. Use an explicit type to silence this warning."
-					);
+				{
+					if (v050)
+						m_errorReporter.typeError(
+							arguments[i]->location(),
+							"Cannot perform packed encoding for a literal. Please convert it to an explicit type first."
+						);
+					else
+						m_errorReporter.warning(
+							arguments[i]->location(),
+							"The type of \"" +
+							argType->toString() +
+							"\" was inferred as " +
+							literal->mobileType()->toString() +
+							". This is probably not desired. Use an explicit type to silence this warning."
+						);
+				}
 			}
 		}
 	}

test/libsolidity/syntaxTests/tight_packing_literals_050.sol

@@ -0,0 +1,26 @@
+pragma experimental "v0.5.0";
+contract C {
+    function f() pure public returns (bytes32) {
+        return keccak256(1);
+    }
+    function g() pure public returns (bytes32) {
+        return sha3(1);
+    }
+    function h() pure public returns (bytes32) {
+        return sha256(1);
+    }
+    function j() pure public returns (bytes32) {
+        return ripemd160(1);
+    }
+    function k() pure public returns (bytes) {
+        return abi.encodePacked(1);
+    }
+}
+
+// ----
+// TypeError: (117-118): Cannot perform packed encoding for a literal. Please convert it to an explicit type first.
+// Warning: (191-198): "sha3" has been deprecated in favour of "keccak256"
+// TypeError: (196-197): Cannot perform packed encoding for a literal. Please convert it to an explicit type first.
+// TypeError: (277-278): Cannot perform packed encoding for a literal. Please convert it to an explicit type first.
+// TypeError: (361-362): Cannot perform packed encoding for a literal. Please convert it to an explicit type first.
+// TypeError: (450-451): Cannot perform packed encoding for a literal. Please convert it to an explicit type first.