Rename ModuleToIndex to PalletRuntimeSetup (#7148)

* Rename `ModuleToIndex` to `PalletRuntimeSetup`

Besides the renaming it also adds support getting the name of a pallet
as configured in the runtime.

* Rename it to `PalletInfo`

* Remove accidentally added files

substrate/frame/support/procedural/src/construct_runtime/mod.rs

@@ -52,6 +52,8 @@ fn construct_runtime_parsed(definition: RuntimeDefinition) -> Result<TokenStream
 		..
 	} = definition;
 
+	let modules = modules.into_pairs().map(|v| v.into_value()).collect::<Vec<_>>();
+
 	// Assert we have system module declared
 	let system_module = match find_system_module(modules.iter()) {
 		Some(sm) => sm,
@@ -82,7 +84,7 @@ fn construct_runtime_parsed(definition: RuntimeDefinition) -> Result<TokenStream
 		&scrate,
 	)?;
 	let all_modules = decl_all_modules(&name, modules.iter());
-	let module_to_index = decl_module_to_index(modules.iter(), modules.len(), &scrate);
+	let module_to_index = decl_pallet_runtime_setup(&modules, &scrate);
 
 	let dispatch = decl_outer_dispatch(&name, modules.iter(), &scrate);
 	let metadata = decl_runtime_metadata(&name, modules.iter(), &scrate, &unchecked_extrinsic);
@@ -376,22 +378,23 @@ fn decl_all_modules<'a>(
 	)
 }
 
-fn decl_module_to_index<'a>(
-	module_declarations: impl Iterator<Item = &'a ModuleDeclaration>,
-	num_modules: usize,
+fn decl_pallet_runtime_setup(
+	module_declarations: &[ModuleDeclaration],
 	scrate: &TokenStream2,
 ) -> TokenStream2 {
-	let names = module_declarations.map(|d| &d.name);
-	let indices = 0..num_modules;
+	let names = module_declarations.iter().map(|d| &d.name);
+	let names2 = module_declarations.iter().map(|d| &d.name);
+	let name_strings = module_declarations.iter().map(|d| d.name.to_string());
+	let indices = 0..module_declarations.len();
 
 	quote!(
-		/// Provides an implementation of `ModuleToIndex` to map a module
-		/// to its index in the runtime.
-		pub struct ModuleToIndex;
+		/// Provides an implementation of `PalletInfo` to provide information
+		/// about the pallet setup in the runtime.
+		pub struct PalletInfo;
 
-		impl #scrate::traits::ModuleToIndex for ModuleToIndex {
-			fn module_to_index<M: 'static>() -> Option<usize> {
-				let type_id = #scrate::sp_std::any::TypeId::of::<M>();
+		impl #scrate::traits::PalletInfo for PalletInfo {
+			fn index<P: 'static>() -> Option<usize> {
+				let type_id = #scrate::sp_std::any::TypeId::of::<P>();
 				#(
 					if type_id == #scrate::sp_std::any::TypeId::of::<#names>() {
 						return Some(#indices)
@@ -400,6 +403,17 @@ fn decl_module_to_index<'a>(
 
 				None
 			}
+
+			fn name<P: 'static>() -> Option<&'static str> {
+				let type_id = #scrate::sp_std::any::TypeId::of::<P>();
+				#(
+					if type_id == #scrate::sp_std::any::TypeId::of::<#names2>() {
+						return Some(#name_strings)
+					}
+				)*
+
+				None
+			}
 		}
 	)
 }

substrate/frame/support/src/error.rs

@@ -140,8 +140,8 @@ macro_rules! decl_error {
 			for $crate::sp_runtime::DispatchError
 		{
 			fn from(err: $error<$generic $(, $inst_generic)?>) -> Self {
-				let index = <$generic::ModuleToIndex as $crate::traits::ModuleToIndex>
-					::module_to_index::<$module<$generic $(, $inst_generic)?>>()
+				let index = <$generic::PalletInfo as $crate::traits::PalletInfo>
+					::index::<$module<$generic $(, $inst_generic)?>>()
 					.expect("Every active module has an index in the runtime; qed") as u8;
 
 				$crate::sp_runtime::DispatchError::Module {

substrate/frame/support/src/metadata.rs

@@ -297,7 +297,7 @@ mod tests {
 			type AccountId: From<u32> + Encode;
 			type BlockNumber: From<u32> + Encode;
 			type SomeValue: Get<u32>;
-			type ModuleToIndex: crate::traits::ModuleToIndex;
+			type PalletInfo: crate::traits::PalletInfo;
 			type Call;
 		}
 
@@ -443,7 +443,7 @@ mod tests {
 		type AccountId = u32;
 		type BlockNumber = u32;
 		type SomeValue = SystemValue;
-		type ModuleToIndex = ();
+		type PalletInfo = ();
 		type Call = Call;
 	}
 

substrate/frame/support/src/traits.rs

@@ -1313,8 +1313,6 @@ impl<T: Clone + Ord> ChangeMembers<T> for () {
 	fn set_prime(_: Option<T>) {}
 }
 
-
-
 /// Trait for type that can handle the initialization of account IDs at genesis.
 pub trait InitializeMembers<AccountId> {
 	/// Initialize the members to the given `members`.
@@ -1380,16 +1378,20 @@ pub trait ValidatorRegistration<ValidatorId> {
 	fn is_registered(id: &ValidatorId) -> bool;
 }
 
-/// Something that can convert a given module into the index of the module in the runtime.
+/// Provides information about the pallet setup in the runtime.
 ///
-/// The index of a module is determined by the position it appears in `construct_runtime!`.
-pub trait ModuleToIndex {
-	/// Convert the given module `M` into an index.
-	fn module_to_index<M: 'static>() -> Option<usize>;
+/// An implementor should be able to provide information about each pallet that
+/// is configured in `construct_runtime!`.
+pub trait PalletInfo {
+	/// Convert the given pallet `P` into its index as configured in the runtime.
+	fn index<P: 'static>() -> Option<usize>;
+	/// Convert the given pallet `P` into its name as configured in the runtime.
+	fn name<P: 'static>() -> Option<&'static str>;
 }
 
-impl ModuleToIndex for () {
-	fn module_to_index<M: 'static>() -> Option<usize> { Some(0) }
+impl PalletInfo for () {
+	fn index<P: 'static>() -> Option<usize> { Some(0) }
+	fn name<P: 'static>() -> Option<&'static str> { Some("test") }
 }
 
 /// The function and pallet name of the Call.

substrate/frame/support/test/tests/construct_runtime.rs

@@ -24,13 +24,14 @@
 use sp_runtime::{generic, traits::{BlakeTwo256, Block as _, Verify}, DispatchError};
 use sp_core::{H256, sr25519};
 use sp_std::cell::RefCell;
+use frame_support::traits::PalletInfo as _;
 
 mod system;
 
 pub trait Currency {}
 
 thread_local! {
-    pub static INTEGRITY_TEST_EXEC: RefCell<u32> = RefCell::new(0);
+	pub static INTEGRITY_TEST_EXEC: RefCell<u32> = RefCell::new(0);
 }
 
 mod module1 {
@@ -107,7 +108,7 @@ impl system::Trait for Runtime {
 	type BlockNumber = BlockNumber;
 	type AccountId = AccountId;
 	type Event = Event;
-	type ModuleToIndex = ModuleToIndex;
+	type PalletInfo = PalletInfo;
 	type Call = Call;
 }
 
@@ -157,3 +158,15 @@ fn integrity_test_works() {
 	__construct_runtime_integrity_test::runtime_integrity_tests();
 	assert_eq!(INTEGRITY_TEST_EXEC.with(|i| *i.borrow()), 1);
 }
+
+#[test]
+fn pallet_in_runtime_is_correct() {
+	assert_eq!(PalletInfo::index::<System>().unwrap(), 0);
+	assert_eq!(PalletInfo::name::<System>().unwrap(), "System");
+
+	assert_eq!(PalletInfo::index::<Module1_2>().unwrap(), 3);
+	assert_eq!(PalletInfo::name::<Module1_2>().unwrap(), "Module1_2");
+
+	assert_eq!(PalletInfo::index::<Module2>().unwrap(), 2);
+	assert_eq!(PalletInfo::name::<Module2>().unwrap(), "Module2");
+}

substrate/frame/support/test/tests/instance.rs

@@ -241,7 +241,7 @@ impl system::Trait for Runtime {
 	type BlockNumber = BlockNumber;
 	type AccountId = AccountId;
 	type Event = Event;
-	type ModuleToIndex = ();
+	type PalletInfo = ();
 	type Call = Call;
 }
 

substrate/frame/support/test/tests/issue2219.rs

@@ -164,7 +164,7 @@ impl system::Trait for Runtime {
 	type BlockNumber = BlockNumber;
 	type AccountId = AccountId;
 	type Event = Event;
-	type ModuleToIndex = ();
+	type PalletInfo = ();
 	type Call = Call;
 }
 

substrate/frame/support/test/tests/system.rs

@@ -27,7 +27,7 @@ pub trait Trait: 'static + Eq + Clone {
 	type AccountId: Encode + EncodeLike + Decode;
 	type Call;
 	type Event: From<Event<Self>>;
-	type ModuleToIndex: frame_support::traits::ModuleToIndex;
+	type PalletInfo: frame_support::traits::PalletInfo;
 }
 
 frame_support::decl_module! {