Abiv2 fuzzer: Enable differential fuzzing and remove support for string coding

co-authored-by: Leonardo <leo@ethereum.org>

test/tools/ossfuzz/AbiV2IsabelleFuzzer.cpp

@@ -24,9 +24,14 @@
 
 using namespace solidity::test::abiv2fuzzer;
 using namespace solidity::test;
+using namespace solidity::util;
+using namespace solidity;
 using namespace std;
 
 static constexpr size_t abiCoderHeapSize = 1024 * 512;
+static evmc::VM evmone = evmc::VM{evmc_create_evmone()};
+/// Expected output value is decimal 0
+static vector<uint8_t> const expectedOutput(32, 0);
 
 DEFINE_PROTO_FUZZER(Contract const& _contract)
 {
@@ -43,13 +48,60 @@ DEFINE_PROTO_FUZZER(Contract const& _contract)
 
 	string typeString = converter.isabelleTypeString();
 	string valueString = converter.isabelleValueString();
-	std::cout << typeString << std::endl;
-	std::cout << valueString << std::endl;
 	abicoder::ABICoder coder(abiCoderHeapSize);
-	if (!typeString.empty())
+	if (!typeString.empty() && converter.coderFunction())
 	{
 		auto [encodeStatus, encodedData] = coder.encode(typeString, valueString);
 		solAssert(encodeStatus, "Isabelle abicoder fuzzer: Encoding failed");
+
+		// Raw runtime byte code generated by solidity
+		bytes byteCode;
+		string hexEncodedInput;
+
+		try
+		{
+			// Compile contract generated by the proto fuzzer
+			SolidityCompilationFramework solCompilationFramework;
+			string contractName = ":C";
+			byteCode = solCompilationFramework.compileContract(contractSource, contractName);
+			Json::Value methodIdentifiers = solCompilationFramework.getMethodIdentifiers();
+			// We always call the second function from the list of alphabetically
+			// sorted interface functions
+			hexEncodedInput = (++methodIdentifiers.begin())->asString() + encodedData.substr(2, encodedData.size());
+		}
+		// Ignore stack too deep errors during compilation
+		catch (solidity::evmasm::StackTooDeepException const&)
+		{
+			return;
+		}
+
+		// We target the default EVM which is the latest
+		solidity::langutil::EVMVersion version;
+		EVMHost hostContext(version, evmone);
+
+		// Deploy contract and signal failure if deployment failed
+		evmc::result createResult = AbiV2Utility::deployContract(hostContext, byteCode);
+		solAssert(
+			createResult.status_code == EVMC_SUCCESS,
+			"Proto ABIv2 Fuzzer: Contract creation failed"
+		);
+
+		// Execute test function and signal failure if EVM reverted or
+		// did not return expected output on successful execution.
+		evmc::result callResult = AbiV2Utility::executeContract(
+			hostContext,
+			fromHex(hexEncodedInput),
+			createResult.create_address
+		);
+
+		// We don't care about EVM One failures other than EVMC_REVERT
+		solAssert(callResult.status_code != EVMC_REVERT, "Proto ABIv2 fuzzer: EVM One reverted");
+		if (callResult.status_code == EVMC_SUCCESS)
+			solAssert(
+				AbiV2Utility::isOutputExpected(callResult.output_data, callResult.output_size, expectedOutput),
+				"Proto ABIv2 fuzzer: ABIv2 coding failure found"
+			);
+
 	}
 	return;
 }

test/tools/ossfuzz/CMakeLists.txt

@@ -151,7 +151,7 @@ if (OSSFUZZ)
             protobuf-mutator.a
             protobuf.a
             abicoder
-            gmp
+            gmp.a
     )
     set_target_properties(abiv2_isabelle_ossfuzz PROPERTIES LINK_FLAGS ${LIB_FUZZING_ENGINE})
     target_compile_options(abiv2_isabelle_ossfuzz PUBLIC ${COMPILE_OPTIONS} -Wno-sign-conversion -Wno-suggest-destructor-override -Wno-inconsistent-missing-destructor-override)

test/tools/ossfuzz/abiV2Proto.proto

@@ -44,14 +44,8 @@ message ValueType {
     }
 }
 
-// bytes/string
-message DynamicByteArrayType {
-    enum DType {
-        BYTES = 0;
-        STRING = 1;
-    }
-    required DType type = 1;
-}
+// bytes
+message DynamicByteArrayType {}
 
 message ArrayType {
     required Type t = 1;

test/tools/ossfuzz/protoToAbiV2.cpp

@@ -830,10 +830,10 @@ string TypeVisitor::visit(ArrayType const& _type)
 	return baseType + arrayBracket;
 }
 
-string TypeVisitor::visit(DynamicByteArrayType const& _type)
+string TypeVisitor::visit(DynamicByteArrayType const&)
 {
 	m_isLastDynParamRightPadded = true;
-	m_baseType = bytesArrayTypeAsString(_type);
+	m_baseType = "bytes";
 	m_structTupleString.addTypeStringToTuple(m_baseType);
 	return m_baseType;
 }
@@ -967,7 +967,7 @@ pair<string, string> AssignCheckVisitor::visit(DynamicByteArrayType const& _type
 		string isabelleValue = ValueGetterVisitor{}.isabelleBytesValueAsString(value);
 		m_valueStream.appendValue(isabelleValue);
 	}
-	DataType dataType = _type.type() == DynamicByteArrayType::BYTES ? DataType::BYTES :	DataType::STRING;
+	DataType dataType = DataType::BYTES;
 	return assignAndCheckStringPair(m_varName, m_paramName, value, value, dataType);
 }
 
@@ -1127,12 +1127,6 @@ string AssignCheckVisitor::checkString(string const& _ref, string const& _value,
 	string checkPred;
 	switch (_type)
 	{
-	case DataType::STRING:
-		checkPred = Whiskers(R"(!bytesCompare(bytes(<varName>), <value>))")
-			("varName", _ref)
-			("value", _value)
-			.render();
-		break;
 	case DataType::BYTES:
 		checkPred = Whiskers(R"(!bytesCompare(<varName>, <value>))")
 			("varName", _ref)
@@ -1288,10 +1282,6 @@ std::string ValueGetterVisitor::variableLengthValueAsString(
 	bool _isHexLiteral
 )
 {
-	// TODO: Move this to caller
-//	solAssert(_numBytes >= 0 && _numBytes <= s_maxDynArrayLength,
-//	          "Proto ABIv2 fuzzer: Invalid hex length"
-//	);
 	if (_numBytes == 0)
 		return Whiskers(R"(<?isHex>hex</isHex>"")")
 			("isHex", _isHexLiteral)

test/tools/ossfuzz/protoToAbiV2.h

@@ -154,6 +154,10 @@ public:
 	std::string contractToString(Contract const& _input);
 	std::string isabelleTypeString() const;
 	std::string isabelleValueString() const;
+	bool coderFunction() const
+	{
+		return m_test == Contract_Test::Contract_Test_CALLDATA_CODER;
+	}
 private:
 	enum class Delimiter
 	{
@@ -448,7 +452,6 @@ public:
 	enum class DataType
 	{
 		BYTES,
-		STRING,
 		VALUE,
 		ARRAY
 	};
@@ -537,17 +540,6 @@ public:
 		else
 			return v;
 	}
-
-	static std::string bytesArrayTypeAsString(DynamicByteArrayType const& _x)
-	{
-		switch (_x.type())
-		{
-		case DynamicByteArrayType::BYTES:
-			return "bytes";
-		case DynamicByteArrayType::STRING:
-			return "string";
-		}
-	}
 protected:
 T visitValueType(ValueType const& _type)
 {