[Deprecation] Remove the deprecated Store trait (paritytech#3532)

# Description

*Removes the deprecated `trait Store` feature from the code base*

Fixes paritytech#222

---------

Co-authored-by: Dónal Murray <donalm@seadanda.dev>

substrate/frame/support/procedural/src/lib.rs

@@ -858,16 +858,6 @@ pub fn disable_frame_system_supertrait_check(_: TokenStream, _: TokenStream) ->
 	pallet_macro_stub()
 }
 
-///
-/// ---
-///
-/// Rust-Analyzer Users: Documentation for this macro can be found at
-/// `frame_support::pallet_macros::generate_store`.
-#[proc_macro_attribute]
-pub fn generate_store(_: TokenStream, _: TokenStream) -> TokenStream {
-	pallet_macro_stub()
-}
-
 ///
 /// ---
 ///

substrate/frame/support/procedural/src/pallet/expand/mod.rs

@@ -31,7 +31,6 @@ mod instances;
 mod origin;
 mod pallet_struct;
 mod storage;
-mod store_trait;
 mod tasks;
 mod tt_default_parts;
 mod type_value;
@@ -68,7 +67,6 @@ pub fn expand(mut def: Def) -> proc_macro2::TokenStream {
 	let storages = storage::expand_storages(&mut def);
 	let inherents = inherent::expand_inherents(&mut def);
 	let instances = instances::expand_instances(&mut def);
-	let store_trait = store_trait::expand_store_trait(&mut def);
 	let hooks = hooks::expand_hooks(&mut def);
 	let genesis_build = genesis_build::expand_genesis_build(&mut def);
 	let genesis_config = genesis_config::expand_genesis_config(&mut def);
@@ -110,7 +108,6 @@ storage item. Otherwise, all storage items are listed among [*Type Definitions*]
 		#storages
 		#inherents
 		#instances
-		#store_trait
 		#hooks
 		#genesis_build
 		#genesis_config

substrate/frame/support/procedural/src/pallet/parse/mod.rs

@@ -558,8 +558,6 @@ mod keyword {
 	syn::custom_keyword!(validate_unsigned);
 	syn::custom_keyword!(type_value);
 	syn::custom_keyword!(pallet);
-	syn::custom_keyword!(generate_store);
-	syn::custom_keyword!(Store);
 	syn::custom_keyword!(extra_constants);
 	syn::custom_keyword!(composite_enum);
 }

substrate/frame/support/procedural/src/pallet/parse/pallet_struct.rs

@@ -23,10 +23,8 @@ use syn::spanned::Spanned;
 mod keyword {
 	syn::custom_keyword!(pallet);
 	syn::custom_keyword!(Pallet);
-	syn::custom_keyword!(generate_store);
 	syn::custom_keyword!(without_storage_info);
 	syn::custom_keyword!(storage_version);
-	syn::custom_keyword!(Store);
 }
 
 /// Definition of the pallet pallet.
@@ -37,8 +35,6 @@ pub struct PalletStructDef {
 	pub instances: Vec<helper::InstanceUsage>,
 	/// The keyword Pallet used (contains span).
 	pub pallet: keyword::Pallet,
-	/// Whether the trait `Store` must be generated.
-	pub store: Option<(syn::Visibility, keyword::Store, proc_macro2::Span)>,
 	/// The span of the pallet::pallet attribute.
 	pub attr_span: proc_macro2::Span,
 	/// Whether to specify the storages max encoded len when implementing `StorageInfoTrait`.
@@ -49,21 +45,17 @@ pub struct PalletStructDef {
 }
 
 /// Parse for one variant of:
-/// * `#[pallet::generate_store($vis trait Store)]`
 /// * `#[pallet::without_storage_info]`
 /// * `#[pallet::storage_version(STORAGE_VERSION)]`
 pub enum PalletStructAttr {
-	GenerateStore { span: proc_macro2::Span, vis: syn::Visibility, keyword: keyword::Store },
 	WithoutStorageInfoTrait(proc_macro2::Span),
 	StorageVersion { storage_version: syn::Path, span: proc_macro2::Span },
 }
 
 impl PalletStructAttr {
 	fn span(&self) -> proc_macro2::Span {
 		match self {
-			Self::GenerateStore { span, .. } |
-			Self::WithoutStorageInfoTrait(span) |
-			Self::StorageVersion { span, .. } => *span,
+			Self::WithoutStorageInfoTrait(span) | Self::StorageVersion { span, .. } => *span,
 		}
 	}
 }
@@ -77,16 +69,7 @@ impl syn::parse::Parse for PalletStructAttr {
 		content.parse::<syn::Token![::]>()?;
 
 		let lookahead = content.lookahead1();
-		if lookahead.peek(keyword::generate_store) {
-			content.parse::<keyword::generate_store>()?;
-			let generate_content;
-			syn::parenthesized!(generate_content in content);
-			let vis = generate_content.parse::<syn::Visibility>()?;
-			generate_content.parse::<syn::Token![trait]>()?;
-			let keyword = generate_content.parse::<keyword::Store>()?;
-			let span = content.span();
-			Ok(Self::GenerateStore { vis, keyword, span })
-		} else if lookahead.peek(keyword::without_storage_info) {
+		if lookahead.peek(keyword::without_storage_info) {
 			let span = content.parse::<keyword::without_storage_info>()?.span();
 			Ok(Self::WithoutStorageInfoTrait(span))
 		} else if lookahead.peek(keyword::storage_version) {
@@ -116,16 +99,12 @@ impl PalletStructDef {
 			return Err(syn::Error::new(item.span(), msg))
 		};
 
-		let mut store = None;
 		let mut without_storage_info = None;
 		let mut storage_version_found = None;
 
 		let struct_attrs: Vec<PalletStructAttr> = helper::take_item_pallet_attrs(&mut item.attrs)?;
 		for attr in struct_attrs {
 			match attr {
-				PalletStructAttr::GenerateStore { vis, keyword, span } if store.is_none() => {
-					store = Some((vis, keyword, span));
-				},
 				PalletStructAttr::WithoutStorageInfoTrait(span)
 					if without_storage_info.is_none() =>
 				{
@@ -162,7 +141,6 @@ impl PalletStructDef {
 			index,
 			instances,
 			pallet,
-			store,
 			attr_span,
 			without_storage_info,
 			storage_version: storage_version_found,

substrate/frame/support/src/lib.rs

@@ -702,7 +702,7 @@ pub use frame_support_procedural::crate_to_crate_version;
 #[macro_export]
 macro_rules! fail {
 	( $y:expr ) => {{
-		return Err($y.into())
+		return Err($y.into());
 	}};
 }
 
@@ -949,7 +949,7 @@ pub mod pallet_prelude {
 /// 	pub trait Config: frame_system::Config {}
 /// }
 /// ```
-///
+//
 /// I.e. a regular struct definition named `Pallet`, with generic T and no where clause.
 ///
 /// ## Macro expansion:
@@ -1341,26 +1341,6 @@ pub mod pallet_macros {
 	/// See [`pallet::storage`](`frame_support::pallet_macros::storage`) for more info.
 	pub use frame_support_procedural::getter;
 
-	/// Allows generating the `Store` trait for all storages.
-	///
-	/// DEPRECATED: Will be removed, do not use.
-	/// See <https://github.com/paritytech/substrate/pull/13535> for more details.
-	///
-	/// To generate a `Store` trait associating all storages, annotate your `Pallet` struct
-	/// with the attribute `#[pallet::generate_store($vis trait Store)]`, e.g.:
-	///
-	/// ```ignore
-	/// #[pallet::pallet]
-	/// #[pallet::generate_store(pub(super) trait Store)]
-	/// pub struct Pallet<T>(_);
-	/// ```
-	/// More precisely, the `Store` trait contains an associated type for each storage. It is
-	/// implemented for `Pallet` allowing access to the storage from pallet struct.
-	///
-	/// Thus when defining a storage named `Foo`, it can later be accessed from `Pallet` using
-	/// `<Pallet as Store>::Foo`.
-	pub use frame_support_procedural::generate_store;
-
 	/// Defines constants that are added to the constant field of
 	/// [`PalletMetadata`](frame_metadata::v15::PalletMetadata) struct for this pallet.
 	///

substrate/frame/support/test/tests/pallet_ui/pallet_struct_invalid_attr.stderr

@@ -1,4 +1,4 @@
-error: expected one of: `generate_store`, `without_storage_info`, `storage_version`
+error: expected `without_storage_info` or `storage_version`
   --> tests/pallet_ui/pallet_struct_invalid_attr.rs:24:12
    |
 24 |     #[pallet::generate_storage_info] // invalid