Deprecate Pallet decl_* Macros

frame/support/procedural/src/lib.rs

@@ -296,6 +296,8 @@ fn counter_prefix(prefix: &str) -> String {
 /// }
 /// ```
 #[proc_macro]
+#[deprecated(note = "Will be removed soon; use the attribute `#[pallet]` macro instead.
+	For more info, see: <https://github.com/paritytech/substrate/pull/13705>")]
 pub fn decl_storage(input: TokenStream) -> TokenStream {
 	storage::decl_storage_impl(input)
 }

frame/support/src/dispatch.rs

@@ -879,6 +879,8 @@ impl<T> PaysFee<T> for (u64, Pays) {
 ///   in an externalities-provided environment. Implement
 ///   [`IntegrityTest`](./trait.IntegrityTest.html) trait.
 #[macro_export]
+#[deprecated(note = "Will be removed soon; use the attribute `#[pallet]` macro instead.
+	For more info, see: <https://github.com/paritytech/substrate/pull/13705>")]
 macro_rules! decl_module {
 	// Entry point #1.
 	(

frame/support/src/error.rs

@@ -67,6 +67,8 @@ pub use sp_runtime::traits::{BadOrigin, LookupError};
 /// For instantiable modules you also need to give the instance generic type and bound to the
 /// error declaration.
 #[macro_export]
+#[deprecated(note = "Will be removed soon; use the attribute `#[pallet]` macro instead.
+	For more info, see: <https://github.com/paritytech/substrate/pull/13705>")]
 macro_rules! decl_error {
 	(
 		$(#[$attr:meta])*

frame/support/src/event.rs

@@ -101,6 +101,8 @@
 /// # fn main() {}
 /// ```
 #[macro_export]
+#[deprecated(note = "Will be removed soon; use the attribute `#[pallet]` macro instead.
+	For more info, see: <https://github.com/paritytech/substrate/pull/13705>")]
 macro_rules! decl_event {
 	(
 		$(#[$attr:meta])*