Method appendStateVariableAccessor

libsolidity/codegen/ExpressionCompiler.cpp:129–286

}

void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const& _varDecl)
{
	solAssert(!_varDecl.isConstant(), "");
	CompilerContext::LocationSetter locationSetter(m_context, _varDecl);
	FunctionType accessorType(_varDecl);

	TypePointers paramTypes = accessorType.parameterTypes();
	if (_varDecl.immutable())
		solAssert(paramTypes.empty(), "");

	m_context.adjustStackOffset(static_cast<int>(1 + CompilerUtils::sizeOnStack(paramTypes)));

	if (!_varDecl.immutable())
	{
		// retrieve the position of the variable
		auto const& location = m_context.storageLocationOfVariable(_varDecl);
		m_context << location.first << u256(location.second);
	}

	Type const* returnType = _varDecl.annotation().type;

	for (size_t i = 0; i < paramTypes.size(); ++i)
	{
		if (auto mappingType = dynamic_cast<MappingType const*>(returnType))
		{
			solAssert(CompilerUtils::freeMemoryPointer >= 0x40, "");
			solAssert(_varDecl.referenceLocation() != VariableDeclaration::Location::Transient);

			// pop offset
			m_context << Instruction::POP;
			if (paramTypes[i]->isDynamicallySized())
			{
				solAssert(
					dynamic_cast<ArrayType const&>(*paramTypes[i]).isByteArrayOrString(),
					"Expected string or byte array for mapping key type"
				);

				// stack: <keys..> <slot position>

				// copy key[i] to top.
				utils().copyToStackTop(static_cast<unsigned>(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
			{