Tests.

test/libyul/ObjectParser.cpp

@@ -250,6 +250,36 @@ BOOST_AUTO_TEST_CASE(to_string)
 	BOOST_CHECK_EQUAL(asmStack.print(), expectation);
 }
 
+BOOST_AUTO_TEST_CASE(arg_to_dataoffset_must_be_literal)
+{
+	string code = R"(
+		object "outer" {
+			code { let x := "outer" let y := dataoffset(x) }
+		}
+	)";
+	CHECK_ERROR(code, TypeError, "Function expects direct literals as arguments.");
+}
+
+BOOST_AUTO_TEST_CASE(arg_to_datasize_must_be_literal)
+{
+	string code = R"(
+		object "outer" {
+			code { let x := "outer" let y := datasize(x) }
+		}
+	)";
+	CHECK_ERROR(code, TypeError, "Function expects direct literals as arguments.");
+}
+
+BOOST_AUTO_TEST_CASE(args_to_datacopy_are_arbitrary)
+{
+	string code = R"(
+		object "outer" {
+			code { let x := 0 let y := 2 let s := 3 datacopy(x, y, s) }
+		}
+	)";
+	BOOST_CHECK(successParse(code));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }

test/libyul/yulOptimizerTests/commonSubexpressionEliminator/object_access.yul

@@ -0,0 +1,23 @@
+{
+    // Arguments to ``datasize`` and ``dataoffset`` need to be
+    // literals. We cannot simplify their arguments, but we can
+    // simplify them as a full expression.
+    // ``datacopy`` does not have this restriction.
+    let r := "abc"
+    let a := datasize("abc")
+    let x := dataoffset("abc")
+    // should be replaced by a
+    let y := datasize("abc")
+    datacopy("abc", x, y)
+    mstore(a, x)
+}
+// ----
+// commonSubexpressionEliminator
+// {
+//     let r := "abc"
+//     let a := datasize("abc")
+//     let x := dataoffset("abc")
+//     let y := a
+//     datacopy(r, x, a)
+//     mstore(a, x)
+// }

test/libyul/yulOptimizerTests/expressionSplitter/object_access.yul

@@ -0,0 +1,21 @@
+{
+    // We should never split arguments to ``dataoffset``
+    // or ``datasize`` because they need to be literals
+    let x := dataoffset("abc")
+    let y := datasize("abc")
+    // datacopy is fine, though
+    datacopy(mload(0), mload(1), mload(2))
+}
+// ----
+// expressionSplitter
+// {
+//     let x := dataoffset("abc")
+//     let y := datasize("abc")
+//     let _1 := 2
+//     let _2 := mload(_1)
+//     let _3 := 1
+//     let _4 := mload(_3)
+//     let _5 := 0
+//     let _6 := mload(_5)
+//     datacopy(_6, _4, _2)
+// }