Contracts: Fix legacy uapi (#3994)

Fix some broken legacy definitions of pallet_contracts_uapi storage host
functions

substrate/frame/contracts/fixtures/contracts/common/src/lib.rs

@@ -149,3 +149,13 @@ macro_rules! output {
 		$host_fn($($arg,)* $output);
 	};
 }
+
+/// Similar to `output!` but unwraps the result.
+#[macro_export]
+macro_rules! unwrap_output {
+	($output: ident, $buffer: expr, $host_fn:path, $($arg:expr),*) => {
+		let mut $output = $buffer;
+		let $output = &mut &mut $output[..];
+		$host_fn($($arg,)* $output).unwrap();
+	};
+}

substrate/frame/contracts/fixtures/contracts/storage.rs

@@ -0,0 +1,63 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! This contract tests the storage APIs. It sets and clears storage values using the different
+//! versions of the storage APIs.
+#![no_std]
+#![no_main]
+
+use common::unwrap_output;
+use uapi::{HostFn, HostFnImpl as api};
+
+#[no_mangle]
+#[polkavm_derive::polkavm_export]
+pub extern "C" fn deploy() {}
+
+#[no_mangle]
+#[polkavm_derive::polkavm_export]
+pub extern "C" fn call() {
+	const KEY: [u8; 32] = [1u8; 32];
+	const VALUE_1: [u8; 4] = [1u8; 4];
+	const VALUE_2: [u8; 4] = [2u8; 4];
+	const VALUE_3: [u8; 4] = [3u8; 4];
+
+	api::set_storage(&KEY, &VALUE_1);
+	assert_eq!(api::contains_storage(&KEY), Some(VALUE_1.len() as _));
+	unwrap_output!(val, [0u8; 4], api::get_storage, &KEY);
+	assert_eq!(**val, VALUE_1);
+
+	let existing = api::set_storage_v1(&KEY, &VALUE_2);
+	assert_eq!(existing, Some(VALUE_1.len() as _));
+	unwrap_output!(val, [0u8; 4], api::get_storage, &KEY);
+	assert_eq!(**val, VALUE_2);
+
+	api::clear_storage(&KEY);
+	assert_eq!(api::contains_storage(&KEY), None);
+
+	let existing = api::set_storage_v2(&KEY, &VALUE_3);
+	assert_eq!(existing, None);
+	assert_eq!(api::contains_storage_v1(&KEY), Some(VALUE_1.len() as _));
+	unwrap_output!(val, [0u8; 32], api::get_storage_v1, &KEY);
+	assert_eq!(**val, VALUE_3);
+
+	api::clear_storage_v1(&KEY);
+	assert_eq!(api::contains_storage_v1(&KEY), None);
+	let existing = api::set_storage_v2(&KEY, &VALUE_3);
+	assert_eq!(existing, None);
+	unwrap_output!(val, [0u8; 32], api::take_storage, &KEY);
+	assert_eq!(**val, VALUE_3);
+}