Merge pull request #6093 from ethereum/mapping-string-keys

Allow dynamic types in public mappings

Changelog.md

@@ -1,6 +1,7 @@
 ### 0.5.5 (unreleased)
 
 Language Features:
+ * Add support for accessors for mappings with string or byte key types
  * Meta programming: Provide access to the name of contracts via ``type(C).name``.
 
 

libsolidity/analysis/TypeChecker.cpp

@@ -511,14 +511,6 @@ bool TypeChecker::visit(VariableDeclaration const& _variable)
 			)
 				m_errorReporter.typeError(_variable.location(), "Array is too large to be encoded.");
 		break;
-	case Type::Category::Mapping:
-		if (auto mappingType = dynamic_cast<MappingType const*>(varType.get()))
-			if (
-				mappingType->keyType()->isDynamicallySized() &&
-				_variable.visibility() == Declaration::Visibility::Public
-			)
-				m_errorReporter.typeError(_variable.location(), "Dynamically-sized keys for public mappings are not supported.");
-		break;
 	default:
 		break;
 	}

libsolidity/codegen/ExpressionCompiler.cpp

@@ -106,18 +106,49 @@ void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const&
 		if (auto mappingType = dynamic_cast<MappingType const*>(returnType.get()))
 		{
 			solAssert(CompilerUtils::freeMemoryPointer >= 0x40, "");
-			solUnimplementedAssert(
-				!paramTypes[i]->isDynamicallySized(),
-				"Accessors for mapping with dynamically-sized keys not yet implemented."
-			);
+
 			// pop offset
 			m_context << Instruction::POP;
-			// move storage offset to memory.
-			utils().storeInMemory(32);
-			// move key to memory.
-			utils().copyToStackTop(paramTypes.size() - i, 1);
-			utils().storeInMemory(0);
-			m_context << u256(64) << u256(0) << Instruction::KECCAK256;
+			if (paramTypes[i]->isDynamicallySized())
+			{
+				solAssert(
+					dynamic_cast<ArrayType const&>(*paramTypes[i]).isByteArray(),
+					"Expected string or byte array for mapping key type"
+				);
+
+				// stack: <keys..> <slot position>
+
+				// copy key[i] to top.
+				utils().copyToStackTop(paramTypes.size() - i + 1, 1);
+
+				m_context.appendInlineAssembly(R"({
+					let key_len := mload(key_ptr)
+					// Temp. use the memory after the array data for the slot
+					// position
+					let post_data_ptr := add(key_ptr, add(key_len, 0x20))
+					let orig_data := mload(post_data_ptr)
+					mstore(post_data_ptr, slot_pos)
+					let hash := keccak256(add(key_ptr, 0x20), add(key_len, 0x20))
+					mstore(post_data_ptr, orig_data)
+					slot_pos := hash
+				})", {"slot_pos", "key_ptr"});
+
+				m_context << Instruction::POP;
+			}
+			else
+			{
+				solAssert(paramTypes[i]->isValueType(), "Expected value type for mapping key");
+
+				// move storage offset to memory.
+				utils().storeInMemory(32);
+
+				// move key to memory.
+				utils().copyToStackTop(paramTypes.size() - i, 1);
+				utils().storeInMemory(0);
+				m_context << u256(64) << u256(0);
+				m_context << Instruction::KECCAK256;
+			}
+
 			// push offset
 			m_context << u256(0);
 			returnType = mappingType->valueType();

test/libsolidity/SolidityEndToEndTest.cpp

@@ -51,6 +51,11 @@ namespace test
 
 BOOST_FIXTURE_TEST_SUITE(SolidityEndToEndTest, SolidityExecutionFramework)
 
+int constexpr roundTo32(int _num)
+{
+	return (_num + 31) / 32 * 32;
+}
+
 BOOST_AUTO_TEST_CASE(transaction_status)
 {
 	char const* sourceCode = R"(
@@ -8435,6 +8440,144 @@ BOOST_AUTO_TEST_CASE(string_as_mapping_key)
 		), encodeArgs(u256(7 + i)));
 }
 
+BOOST_AUTO_TEST_CASE(string_as_public_mapping_key)
+{
+	char const* sourceCode = R"(
+		contract Test {
+			mapping(string => uint) public data;
+			function set(string memory _s, uint _v) public { data[_s] = _v; }
+		}
+	)";
+	compileAndRun(sourceCode, 0, "Test");
+	vector<string> strings{
+		"Hello, World!",
+		"Hello,                            World!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1111",
+		"",
+		"1"
+	};
+	for (unsigned i = 0; i < strings.size(); i++)
+		ABI_CHECK(callContractFunction(
+			"set(string,uint256)",
+			u256(0x40),
+			u256(7 + i),
+			u256(strings[i].size()),
+			strings[i]
+		), encodeArgs());
+	for (unsigned i = 0; i < strings.size(); i++)
+		ABI_CHECK(callContractFunction(
+			"data(string)",
+			u256(0x20),
+			u256(strings[i].size()),
+			strings[i]
+		), encodeArgs(u256(7 + i)));
+}
+
+BOOST_AUTO_TEST_CASE(nested_string_as_public_mapping_key)
+{
+	char const* sourceCode = R"(
+		contract Test {
+			mapping(string => mapping(string => uint)) public data;
+			function set(string memory _s, string memory _s2, uint _v) public {
+				data[_s][_s2] = _v; }
+		}
+	)";
+	compileAndRun(sourceCode, 0, "Test");
+	vector<string> strings{
+		"Hello, World!",
+		"Hello,                            World!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1111",
+		"",
+		"1",
+		"last one"
+	};
+	for (unsigned i = 0; i + 1 < strings.size(); i++)
+		ABI_CHECK(callContractFunction(
+			"set(string,string,uint256)",
+			u256(0x60),
+			u256(roundTo32(0x80 + strings[i].size())),
+			u256(7 + i),
+			u256(strings[i].size()),
+			strings[i],
+			u256(strings[i+1].size()),
+			strings[i+1]
+		), encodeArgs());
+	for (unsigned i = 0; i + 1 < strings.size(); i++)
+		ABI_CHECK(callContractFunction(
+			"data(string,string)",
+			u256(0x40),
+			u256(roundTo32(0x60 + strings[i].size())),
+			u256(strings[i].size()),
+			strings[i],
+			u256(strings[i+1].size()),
+			strings[i+1]
+		), encodeArgs(u256(7 + i)));
+}
+
+BOOST_AUTO_TEST_CASE(nested_mixed_string_as_public_mapping_key)
+{
+	char const* sourceCode = R"(
+		contract Test {
+			mapping(string =>
+				mapping(int =>
+					mapping(address =>
+						mapping(bytes => int)))) public data;
+
+			function set(
+				string memory _s1,
+				int _s2,
+				address _s3,
+				bytes memory _s4,
+				int _value
+			) public
+			{
+				data[_s1][_s2][_s3][_s4] = _value;
+			}
+		}
+	)";
+	compileAndRun(sourceCode, 0, "Test");
+
+	struct Index
+	{
+		string s1;
+		int s2;
+		int s3;
+		string s4;
+	};
+
+	vector<Index> data{
+		{ "aabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcbc", 4, 23, "efg" },
+		{ "tiaron", 456, 63245, "908apzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapzapz" },
+		{ "", 2345, 12934, "665i65i65i65i65i65i65i65i65i65i65i65i65i65i65i65i65i65i5iart" },
+		{ "¡¿…", 9781, 8148, "" },
+		{ "ρν♀♀ω₂₃♀", 929608, 303030, "" }
+	};
+
+	for (size_t i = 0; i + 1 < data.size(); i++)
+		ABI_CHECK(callContractFunction(
+			"set(string,int256,address,bytes,int256)",
+			u256(0xA0),
+			u256(data[i].s2),
+			u256(data[i].s3),
+			u256(roundTo32(0xC0 + data[i].s1.size())),
+			u256(i - 3),
+			u256(data[i].s1.size()),
+			data[i].s1,
+			u256(data[i].s4.size()),
+			data[i].s4
+		), encodeArgs());
+	for (size_t i = 0; i + 1 < data.size(); i++)
+		ABI_CHECK(callContractFunction(
+			"data(string,int256,address,bytes)",
+			u256(0x80),
+			u256(data[i].s2),
+			u256(data[i].s3),
+			u256(roundTo32(0xA0 + data[i].s1.size())),
+			u256(data[i].s1.size()),
+			data[i].s1,
+			u256(data[i].s4.size()),
+			data[i].s4
+		), encodeArgs(u256(i - 3)));
+}
+
 BOOST_AUTO_TEST_CASE(accessor_for_state_variable)
 {
 	char const* sourceCode = R"(

test/libsolidity/syntaxTests/types/mapping/mapping_dynamic_key_public.sol

@@ -2,4 +2,3 @@ contract c {
 	mapping(string => uint) public data;
 }
 // ----
-// TypeError: (14-49): Dynamically-sized keys for public mappings are not supported.