Disallow structs in events without ABIEncoderV2

Changelog.md

@@ -80,6 +80,7 @@ Bugfixes:
  * References Resolver: Enforce ``storage`` as data location for mappings.
  * References Resolver: Report error instead of assertion fail when FunctionType has an undeclared type as parameter.
  * Type Checker: Consider fixed size arrays when checking for recursive structs.
+ * Type Checker: Report error when using structs in events without experimental ABIEncoderV2. This used to crash or log the wrong values.
  * Type System: Allow arbitrary exponents for literals with a mantissa of zero.
 
 ### 0.4.24 (2018-05-16)

libsolidity/analysis/TypeChecker.cpp

@@ -817,6 +817,7 @@ void TypeChecker::visitManually(
 
 bool TypeChecker::visit(EventDefinition const& _eventDef)
 {
+	solAssert(_eventDef.visibility() > Declaration::Visibility::Internal, "");
 	unsigned numIndexed = 0;
 	for (ASTPointer<VariableDeclaration> const& var: _eventDef.parameters())
 	{
@@ -826,6 +827,15 @@ bool TypeChecker::visit(EventDefinition const& _eventDef)
 			m_errorReporter.typeError(var->location(), "Type is required to live outside storage.");
 		if (!type(*var)->interfaceType(false))
 			m_errorReporter.typeError(var->location(), "Internal or recursive type is not allowed as event parameter type.");
+		if (
+			!_eventDef.sourceUnit().annotation().experimentalFeatures.count(ExperimentalFeature::ABIEncoderV2) &&
+			!typeSupportedByOldABIEncoder(*type(*var))
+		)
+			m_errorReporter.typeError(
+				var->location(),
+				"This type is only supported in the new experimental ABI encoder. "
+				"Use \"pragma experimental ABIEncoderV2;\" to enable the feature."
+			);
 	}
 	if (_eventDef.isAnonymous() && numIndexed > 4)
 		m_errorReporter.typeError(_eventDef.location(), "More than 4 indexed arguments for anonymous event.");

test/libsolidity/SolidityABIJSON.cpp

@@ -980,6 +980,7 @@ BOOST_AUTO_TEST_CASE(return_structs_with_contracts)
 BOOST_AUTO_TEST_CASE(event_structs)
 {
 	char const* text = R"(
+		pragma experimental ABIEncoderV2;
 		contract C {
 			struct S { uint a; T[] sub; bytes b; }
 			struct T { uint[2] x; }

test/libsolidity/syntaxTests/events/event_nested_array.sol

@@ -0,0 +1,5 @@
+contract c {
+    event E(uint[][]);
+}
+// ----
+// TypeError: (25-33): This type is only supported in the new experimental ABI encoder. Use "pragma experimental ABIEncoderV2;" to enable the feature.

test/libsolidity/syntaxTests/events/event_nested_array_2.sol

@@ -0,0 +1,4 @@
+contract c {
+    event E(uint[2][]);
+}
+// ----

test/libsolidity/syntaxTests/events/event_nested_array_in_struct.sol

@@ -0,0 +1,6 @@
+contract c {
+	struct S { uint x; uint[][] arr; }
+    event E(S);
+}
+// ----
+// TypeError: (61-62): This type is only supported in the new experimental ABI encoder. Use "pragma experimental ABIEncoderV2;" to enable the feature.

test/libsolidity/syntaxTests/events/event_struct.sol

@@ -0,0 +1,6 @@
+contract c {
+    struct S { uint a ; }
+    event E(S);
+}
+// ----
+// TypeError: (51-52): This type is only supported in the new experimental ABI encoder. Use "pragma experimental ABIEncoderV2;" to enable the feature.

test/libsolidity/syntaxTests/events/event_struct_indexed.sol

@@ -0,0 +1,6 @@
+contract c {
+    struct S { uint a ; }
+    event E(S indexed);
+}
+// ----
+// TypeError: (51-52): This type is only supported in the new experimental ABI encoder. Use "pragma experimental ABIEncoderV2;" to enable the feature.