Emit error when Config part is imported but without the std feature

frame/support/test/Cargo.toml

@@ -25,6 +25,7 @@ pretty_assertions = "0.6.1"
 rustversion = "1.0.0"
 frame-metadata = { version = "13.0.0", default-features = false, path = "../../metadata" }
 frame-system = { version = "3.0.0", default-features = false, path = "../../system" }
+test-pallet = { package = "frame-support-test-pallet", default-features = false, path = "pallet" }
 
 [features]
 default = ["std"]

frame/support/test/pallet/Cargo.toml

@@ -0,0 +1,31 @@
+[package]
+name = "frame-support-test-pallet"
+version = "3.0.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2018"
+license = "Apache-2.0"
+publish = false
+homepage = "https://substrate.dev"
+repository = "https://github.com/paritytech/substrate/"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "2.0.0", default-features = false, features = ["derive"] }
+sp-io = { version = "3.0.0", path = "../../../../primitives/io", default-features = false }
+sp-runtime = { version = "3.0.0", default-features = false, path = "../../../../primitives/runtime" }
+sp-std = { version = "3.0.0", default-features = false, path = "../../../../primitives/std" }
+frame-support = { version = "3.0.0", default-features = false, path = "../../" }
+frame-system = { version = "3.0.0", default-features = false, path = "../../../system" }
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"frame-support/std",
+	"frame-system/std",
+	"sp-io/std",
+	"sp-std/std",
+	"sp-runtime/std",
+]

frame/support/test/pallet/src/lib.rs

@@ -0,0 +1,46 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2021 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.
+pub use pallet::*;
+
+#[frame_support::pallet]
+pub mod pallet {
+	#[allow(unused_imports)]
+	use frame_support::pallet_prelude::*;
+	#[allow(unused_imports)]
+	use frame_system::pallet_prelude::*;
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {}
+
+	#[pallet::genesis_config]
+	pub struct GenesisConfig {}
+
+	#[cfg(feature = "std")]
+	impl Default for GenesisConfig {
+		fn default() -> Self {
+			Self {}
+		}
+	}
+
+	#[pallet::genesis_build]
+	impl<T: Config> GenesisBuild<T> for GenesisConfig {
+		fn build(&self) {}
+	}
+}

frame/support/test/tests/construct_runtime_ui/no_std_genesis_config.rs

@@ -0,0 +1,24 @@
+use frame_support::construct_runtime;
+use sp_runtime::{generic, traits::BlakeTwo256};
+use sp_core::sr25519;
+
+pub type Signature = sr25519::Signature;
+pub type BlockNumber = u64;
+pub type Header = generic::Header<BlockNumber, BlakeTwo256>;
+pub type Block = generic::Block<Header, UncheckedExtrinsic>;
+pub type UncheckedExtrinsic = generic::UncheckedExtrinsic<u32, Call, Signature, ()>;
+
+impl test_pallet::Config for Runtime {}
+
+construct_runtime! {
+	pub enum Runtime where
+		Block = Block,
+		NodeBlock = Block,
+		UncheckedExtrinsic = UncheckedExtrinsic
+	{
+		System: system::{Pallet, Call, Storage, Config, Event<T>},
+		Pallet: test_pallet::{Pallet, Config},
+	}
+}
+
+fn main() {}

frame/support/test/tests/construct_runtime_ui/no_std_genesis_config.stderr

@@ -0,0 +1,66 @@
+error: `Pallet` does not have the std feature enabled, this will cause the `PalletConfig` type to be undefined.
+  --> $DIR/no_std_genesis_config.rs:13:1
+   |
+13 | / construct_runtime! {
+14 | |     pub enum Runtime where
+15 | |         Block = Block,
+16 | |         NodeBlock = Block,
+...  |
+21 | |     }
+22 | | }
+   | |_^
+   |
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0433]: failed to resolve: use of undeclared crate or module `system`
+  --> $DIR/no_std_genesis_config.rs:19:11
+   |
+19 |         System: system::{Pallet, Call, Storage, Config, Event<T>},
+   |                 ^^^^^^ use of undeclared crate or module `system`
+
+error[E0433]: failed to resolve: use of undeclared crate or module `system`
+  --> $DIR/no_std_genesis_config.rs:13:1
+   |
+13 | / construct_runtime! {
+14 | |     pub enum Runtime where
+15 | |         Block = Block,
+16 | |         NodeBlock = Block,
+...  |
+21 | |     }
+22 | | }
+   | |_^ not found in `system`
+   |
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider importing this enum
+   |
+1  | use frame_system::RawOrigin;
+   |
+
+error[E0412]: cannot find type `GenesisConfig` in crate `test_pallet`
+  --> $DIR/no_std_genesis_config.rs:13:1
+   |
+13 | / construct_runtime! {
+14 | |     pub enum Runtime where
+15 | |         Block = Block,
+16 | |         NodeBlock = Block,
+...  |
+21 | |     }
+22 | | }
+   | |_^ not found in `test_pallet`
+   |
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider importing this struct
+   |
+1  | use frame_system::GenesisConfig;
+   |
+
+error[E0277]: the trait bound `Runtime: frame_system::pallet::Config` is not satisfied
+  --> $DIR/no_std_genesis_config.rs:11:6
+   |
+11 | impl test_pallet::Config for Runtime {}
+   |      ^^^^^^^^^^^^^^^^^^^ the trait `frame_system::pallet::Config` is not implemented for `Runtime`
+   |
+  ::: $WORKSPACE/frame/support/test/pallet/src/lib.rs
+   |
+   |     pub trait Config: frame_system::Config {}
+   |                       -------------------- required by this bound in `Config`