Emit error when construct_runtime imports a non-existent pallet part

[KiChjang]

Fixes #8945.

This PR causes an error to be thrown during compilation when Substrate detects that your construct_runtime is importing a pallet part that has not been declared by the pallet in question.

The expected UI for this error looks like the following:

error: Pallet does not have #[pallet::call] defined, perhaps you should remove it from `construct_runtime`?
  --> $DIR/undefined_call_part.rs:3:1
   |
3  |   #[frame_support::pallet]
   |   ^^^^^^^^^^^^^^^^^^^^^^^^
...
12 | / construct_runtime! {
13 | |     pub enum Runtime where
14 | |         Block = Block,
15 | |         NodeBlock = Block,
...  |
20 | |     }
21 | | }
   | |_- in this macro invocation
   |
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

polkadot companion: paritytech/polkadot#3216

[KiChjang]

I wanted to add a UI test for this, and I had the following under the construct_runtime_ui directory:

use frame_support::construct_runtime;

#[frame_support::pallet]
mod pallet {
	#[pallet::config]
	pub trait Config: frame_system::Config {}

	#[pallet::pallet]
	pub struct Pallet<T>(_);
}

construct_runtime! {
	pub enum Runtime where
		Block = Block,
		NodeBlock = Block,
		UncheckedExtrinsic = UncheckedExtrinsic
	{
		System: system::{Pallet},
		Pallet: pallet::{Pallet, Call},
	}
}

fn main() {}

This does generate the compiler error that I expect, but with a lot more junk associated with it:

error: Pallet does not have #[pallet::call] defined. Did you forget to include it?
  --> $DIR/undefined_call_part.rs:3:1
   |
3  |   #[frame_support::pallet]
   |   ^^^^^^^^^^^^^^^^^^^^^^^^
...
12 | / construct_runtime! {
13 | |     pub enum Runtime where
14 | |         Block = Block,
15 | |         NodeBlock = Block,
...  |
20 | |     }
21 | | }
   | |_- in this macro invocation
   |
   = 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/undefined_call_part.rs:18:11
   |
18 |         System: system::{Pallet},
   |                 ^^^^^^ use of undeclared crate or module `system`

error[E0412]: cannot find type `UncheckedExtrinsic` in this scope
  --> $DIR/undefined_call_part.rs:16:24
   |
16 |         UncheckedExtrinsic = UncheckedExtrinsic
   |                              ^^^^^^^^^^^^^^^^^^ not found in this scope
   |
help: consider importing this struct
   |
1  | use sp_runtime::generic::UncheckedExtrinsic;
   |

error[E0412]: cannot find type `Block` in this scope
  --> $DIR/undefined_call_part.rs:15:15
   |
15 |         NodeBlock = Block,
   |                     ^^^^^ not found in this scope
   |
help: consider importing one of these items
   |
1  | use sp_runtime::generic::Block;
   |
1  | use sp_runtime::testing::Block;
   |
1  | use sp_runtime::traits::Block;
   |

error[E0412]: cannot find type `Block` in this scope
  --> $DIR/undefined_call_part.rs:14:11
   |
14 |         Block = Block,
   |                 ^^^^^ not found in this scope
   |
help: consider importing one of these items
   |
1  | use sp_runtime::generic::Block;
   |
1  | use sp_runtime::testing::Block;
   |
1  | use sp_runtime::traits::Block;
   |

error[E0433]: failed to resolve: use of undeclared crate or module `system`
  --> $DIR/undefined_call_part.rs:12:1
   |
12 | / construct_runtime! {
13 | |     pub enum Runtime where
14 | |         Block = Block,
15 | |         NodeBlock = Block,
...  |
20 | |     }
21 | | }
   | |_^ 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[E0277]: the trait bound `Runtime: pallet::Config` is not satisfied
  --> $DIR/undefined_call_part.rs:12:1
   |
12 | / construct_runtime! {
13 | |     pub enum Runtime where
14 | |         Block = Block,
15 | |         NodeBlock = Block,
...  |
20 | |     }
21 | | }
   | |_^ the trait `pallet::Config` is not implemented for `Runtime`
   |
   = note: required because of the requirements on the impl of `Callable<Runtime>` for `pallet::Pallet<Runtime>`
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `Runtime: pallet::Config` is not satisfied
  --> $DIR/undefined_call_part.rs:12:1
   |
12 | / construct_runtime! {
13 | |     pub enum Runtime where
14 | |         Block = Block,
15 | |         NodeBlock = Block,
...  |
20 | |     }
21 | | }
   | |_^ the trait `pallet::Config` is not implemented for `Runtime`
   |
   = note: required because of the requirements on the impl of `Callable<Runtime>` for `pallet::Pallet<Runtime>`
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `Runtime: pallet::Config` is not satisfied
  --> $DIR/undefined_call_part.rs:12:1
   |
12 | / construct_runtime! {
13 | |     pub enum Runtime where
14 | |         Block = Block,
15 | |         NodeBlock = Block,
...  |
20 | |     }
21 | | }
   | |_^ the trait `pallet::Config` is not implemented for `Runtime`
   |
   = note: required because of the requirements on the impl of `Callable<Runtime>` for `pallet::Pallet<Runtime>`
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `Runtime: pallet::Config` is not satisfied
   --> $DIR/undefined_call_part.rs:12:1
    |
12  | / construct_runtime! {
13  | |     pub enum Runtime where
14  | |         Block = Block,
15  | |         NodeBlock = Block,
...   |
20  | |     }
21  | | }
    | |_^ the trait `pallet::Config` is not implemented for `Runtime`
    |
   ::: /home/keith/.cargo/registry/src/github.com-1ecc6299db9ec823/parity-scale-codec-2.1.0/src/codec.rs:270:19
    |
270 |   pub trait Decode: Sized {
    |                     ----- required by this bound in `Decode`
    |
    = note: required because of the requirements on the impl of `Callable<Runtime>` for `pallet::Pallet<Runtime>`
    = note: required because it appears within the type `Call`
    = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `Runtime: pallet::Config` is not satisfied
  --> $DIR/undefined_call_part.rs:12:1
   |
12 | / construct_runtime! {
13 | |     pub enum Runtime where
14 | |         Block = Block,
15 | |         NodeBlock = Block,
...  |
20 | |     }
21 | | }
   | |_^ the trait `pallet::Config` is not implemented for `Runtime`
   |
  ::: /home/keith/.cargo/registry/src/github.com-1ecc6299db9ec823/parity-scale-codec-2.1.0/src/encode_like.rs:73:41
   |
73 |   pub trait EncodeLike<T: Encode = Self>: Sized + Encode {}
   |                                           ----- required by this bound in `EncodeLike`
   |
   = note: required because of the requirements on the impl of `Callable<Runtime>` for `pallet::Pallet<Runtime>`
   = note: required because it appears within the type `Call`
   = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `Runtime: pallet::Config` is not satisfied
   --> $DIR/undefined_call_part.rs:12:1
    |
12  | / construct_runtime! {
13  | |     pub enum Runtime where
14  | |         Block = Block,
15  | |         NodeBlock = Block,
...   |
20  | |     }
21  | | }
    | |_^ the trait `pallet::Config` is not implemented for `Runtime`
    |
   ::: $RUST/core/src/clone.rs
    |
    |   pub trait Clone: Sized {
    |                    ----- required by this bound in `Clone`
    |
    = note: required because of the requirements on the impl of `Callable<Runtime>` for `pallet::Pallet<Runtime>`
    = note: required because it appears within the type `Call`
    = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `Runtime: pallet::Config` is not satisfied
  --> $DIR/undefined_call_part.rs:12:1
   |
12 | / construct_runtime! {
13 | |     pub enum Runtime where
14 | |         Block = Block,
15 | |         NodeBlock = Block,
...  |
20 | |     }
21 | | }
   | |_^ the trait `pallet::Config` is not implemented for `Runtime`
   |
   = note: required because of the requirements on the impl of `Callable<Runtime>` for `pallet::Pallet<Runtime>`
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `Runtime: pallet::Config` is not satisfied
  --> $DIR/undefined_call_part.rs:12:1
   |
12 | / construct_runtime! {
13 | |     pub enum Runtime where
14 | |         Block = Block,
15 | |         NodeBlock = Block,
...  |
20 | |     }
21 | | }
   | |_^ the trait `pallet::Config` is not implemented for `Runtime`
   |
   = note: required because of the requirements on the impl of `Callable<Runtime>` for `pallet::Pallet<Runtime>`
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `Runtime: pallet::Config` is not satisfied
   --> $DIR/undefined_call_part.rs:12:1
    |
12  | / construct_runtime! {
13  | |     pub enum Runtime where
14  | |         Block = Block,
15  | |         NodeBlock = Block,
...   |
20  | |     }
21  | | }
    | |_^ the trait `pallet::Config` is not implemented for `Runtime`
    |
   ::: $RUST/core/src/result.rs
    |
    |   pub enum Result<T, E> {
    |                   - required by this bound in `Result`
    |
    = note: required because of the requirements on the impl of `Callable<Runtime>` for `pallet::Pallet<Runtime>`
    = note: required because it appears within the type `Call`
    = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

[gui1117]

yes this is an improvment,

a sidenote: when we implement this: #8084 use will only give part not to include, and construct_runtime should be able to get all the available part of a pallet. Thus we can check that the "part not to include" specified by the user are sensible.

That makes me think of yet another improvement: currently when people forget to specify in their cargo.toml to compile the pallet crate with "std" feature, then the genesis config type is not available, when they are confused why the compiler say it can't find GenesisConfig.
With a similar trick as you propose we can have a macro: __is_std_enabled! which would be called before accessing the genesis config type. The macro __is_std_enabled! would fail saying that the pallet is not compile with std, in case ppl failed their cargo.toml definition.

[KiChjang]

So I'm really liking the suggestion made by @shawntabrizi over the FRAME steering call, where we create a brand new construct_runtime_v2 macro and document it so that it only works for FRAMEv2 macros, instead of trying to make FRAMEv1 macros forward-compatible with this PR.

This has an intended side effect of telling people "hey, look at all the cool stuff you can do with FRAMEv2" and incentivizing them to migrate over to v2 as soon as possible.

[KiChjang]

Ok, CI keeps choking on the tests/pallet_ui/storage_info_unsatisfied_nmap.rs test. Tried changing the test expectations for that file, but then the output matches the unchanged UI expectation. This is a real Heisenbug.

[KiChjang]

bot merge

[ghost]

Trying merge.