Yul interpreter: Limit nesting level

test/tools/ossfuzz/yulFuzzerCommon.cpp

@@ -27,12 +27,14 @@ yulFuzzerUtil::TerminationReason yulFuzzerUtil::interpret(
 	shared_ptr<yul::Block> _ast,
 	Dialect const& _dialect,
 	size_t _maxSteps,
-	size_t _maxTraceSize
+	size_t _maxTraceSize,
+	size_t _maxExprNesting
 )
 {
 	InterpreterState state;
 	state.maxTraceSize = _maxTraceSize;
 	state.maxSteps = _maxSteps;
+	state.maxExprNesting = _maxExprNesting;
 	// Add 64 bytes of pseudo-randomly generated calldata so that
 	// calldata opcodes perform non trivial work.
 	state.calldata = {
@@ -59,6 +61,10 @@ yulFuzzerUtil::TerminationReason yulFuzzerUtil::interpret(
 	{
 		reason = TerminationReason::TraceLimitReached;
 	}
+	catch (ExpressionNestingLimitReached const&)
+	{
+		reason = TerminationReason::ExpresionNestingLimitReached;
+	}
 	catch (ExplicitlyTerminated const&)
 	{
 		reason = TerminationReason::ExplicitlyTerminated;

test/tools/ossfuzz/yulFuzzerCommon.h

@@ -28,6 +28,7 @@ struct yulFuzzerUtil
 		ExplicitlyTerminated,
 		StepLimitReached,
 		TraceLimitReached,
+		ExpresionNestingLimitReached,
 		None
 	};
 
@@ -36,10 +37,12 @@ struct yulFuzzerUtil
 		std::shared_ptr<yul::Block> _ast,
 		Dialect const& _dialect,
 		size_t _maxSteps = maxSteps,
-		size_t _maxTraceSize = maxTraceSize
+		size_t _maxTraceSize = maxTraceSize,
+		size_t _maxExprNesting = maxExprNesting
 	);
 	static size_t constexpr maxSteps = 100;
 	static size_t constexpr maxTraceSize = 75;
+	static size_t constexpr maxExprNesting = 60;
 };
 
 }

test/tools/ossfuzz/yulProto_diff_ossfuzz.cpp

@@ -91,19 +91,25 @@ DEFINE_PROTO_FUZZER(Program const& _input)
 
 	ostringstream os1;
 	ostringstream os2;
-	yulFuzzerUtil::interpret(
+	yulFuzzerUtil::TerminationReason termReason = yulFuzzerUtil::interpret(
 		os1,
 		stack.parserResult()->code,
 		EVMDialect::strictAssemblyForEVMObjects(version)
 	);
 
+	if (
+		termReason == yulFuzzerUtil::TerminationReason::StepLimitReached ||
+		termReason == yulFuzzerUtil::TerminationReason::TraceLimitReached ||
+		termReason == yulFuzzerUtil::TerminationReason::ExpresionNestingLimitReached
+	)
+		return;
+
 	stack.optimize();
-	yulFuzzerUtil::TerminationReason termReason = yulFuzzerUtil::interpret(
+	termReason = yulFuzzerUtil::interpret(
 		os2,
 		stack.parserResult()->code,
 		EVMDialect::strictAssemblyForEVMObjects(version)
 	);
-
 	if (termReason == yulFuzzerUtil::TerminationReason::StepLimitReached)
 		return;