Merge pull request #8824 from ethereum/solYulDirtyMemory

Fix accessing memory reference types in yul codegen and clean up on memory reads.

libsolidity/codegen/YulUtilFunctions.cpp

@@ -2245,7 +2245,6 @@ string YulUtilFunctions::readFromMemoryOrCalldata(Type const& _type, bool _fromC
 		}
 
 		solAssert(_type.isValueType(), "");
-
 		if (auto const* funType = dynamic_cast<FunctionType const*>(&_type))
 			if (funType->kind() == FunctionType::Kind::External)
 				return Whiskers(R"(
@@ -2259,18 +2258,23 @@ string YulUtilFunctions::readFromMemoryOrCalldata(Type const& _type, bool _fromC
 				("splitFunction", splitExternalFunctionIdFunction())
 				.render();
 
+
 		return Whiskers(R"(
-			function <functionName>(memPtr) -> value {
-				value := <load>(memPtr)
-				<?needsValidation>
+			function <functionName>(ptr) -> value {
+				<?fromCalldata>
+					value := calldataload(ptr)
 					<validate>(value)
-				</needsValidation>
+				<!fromCalldata>
+					value := <cleanup>(mload(ptr))
+				</fromCalldata>
 			}
 		)")
 		("functionName", functionName)
-		("load", _fromCalldata ? "calldataload" : "mload")
-		("needsValidation", _fromCalldata)
-		("validate", _fromCalldata ? validatorFunction(_type) : "")
+		("fromCalldata", _fromCalldata)
+		("validate", validatorFunction(_type))
+		// Byte array elements generally need cleanup.
+		// Other types are cleaned as well to account for dirty memory e.g. due to inline assembly.
+		("cleanup", cleanupFunction(_type))
 		.render();
 	});
 }

libsolidity/codegen/YulUtilFunctions.h

@@ -204,7 +204,7 @@ public:
 	std::string readFromStorage(Type const& _type, size_t _offset, bool _splitFunctionTypes);
 	std::string readFromStorageDynamic(Type const& _type, bool _splitFunctionTypes);
 
-	/// @returns a function that reads a value type from memory.
+	/// @returns a function that reads a value type from memory. Performs cleanup.
 	/// signature: (addr) -> value
 	std::string readFromMemory(Type const& _type);
 	/// @returns a function that reads a value type from calldata.

libsolidity/codegen/ir/IRGeneratorForStatements.cpp

@@ -117,10 +117,12 @@ struct CopyTranslate: public yul::ASTCopier
 			reference.isOffset == false && reference.isSlot == false,
 			"Should not be called for offset/slot"
 		);
+		auto const& var = m_context.localVariable(*varDecl);
+		solAssert(var.type().sizeOnStack() == 1, "");
 
 		return yul::Identifier{
 			_identifier.location,
-			yul::YulString{m_context.localVariable(*varDecl).name()}
+			yul::YulString{var.commaSeparatedList()}
 		};
 	}
 
@@ -2080,13 +2082,7 @@ IRVariable IRGeneratorForStatements::readFromLValue(IRLValue const& _lvalue)
 					")\n";
 		},
 		[&](IRLValue::Memory const& _memory) {
-			if (_memory.byteArrayElement)
-				define(result) <<
-					m_utils.cleanupFunction(_lvalue.type) <<
-					"(mload(" <<
-					_memory.address <<
-					"))\n";
-			else if (_lvalue.type.isValueType())
+			if (_lvalue.type.isValueType())
 				define(result) <<
 					m_utils.readFromMemory(_lvalue.type) <<
 					"(" <<