[Enhancement] Throw an error when there are too many pallets

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

@@ -157,7 +157,7 @@ use proc_macro::TokenStream;
 use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
 use std::{collections::HashSet, str::FromStr};
-use syn::{Ident, Result};
+use syn::{spanned::Spanned, Ident, Result};
 
 /// The fixed name of the system pallet.
 const SYSTEM_PALLET_NAME: &str = "System";
@@ -170,9 +170,12 @@ pub fn construct_runtime(input: TokenStream) -> TokenStream {
 
 	let res = match definition {
 		RuntimeDeclaration::Implicit(implicit_def) =>
-			construct_runtime_intermediary_expansion(input_copy.into(), implicit_def),
+			check_pallet_number(input_copy.clone().into(), implicit_def.pallets.len()).and_then(
+				|_| construct_runtime_intermediary_expansion(input_copy.into(), implicit_def),
+			),
 		RuntimeDeclaration::Explicit(explicit_decl) =>
-			construct_runtime_final_expansion(explicit_decl),
+			check_pallet_number(input_copy.into(), explicit_decl.pallets.len())
+				.and_then(|_| construct_runtime_final_expansion(explicit_decl)),
 	};
 
 	res.unwrap_or_else(|e| e.to_compile_error()).into()
@@ -616,3 +619,34 @@ fn decl_static_assertions(
 		#(#error_encoded_size_check)*
 	}
 }
+
+fn check_pallet_number(input: TokenStream2, pallet_num: usize) -> Result<()> {
+	let max_pallet_num = {
+		if cfg!(feature = "tuples-96") {
+			96
+		} else if cfg!(feature = "tuples-128") {
+			128
+		} else {
+			64
+		}
+	};
+
+	if pallet_num > max_pallet_num {
+		let no_feature = max_pallet_num == 128;
+		return Err(syn::Error::new(
+			input.span(),
+			format!(
+				"{} To increase this limit, enable the tuples-{} feature of [frame_support]. {}",
+				"The number of pallets exceeds the maximum number of tuple elements.",
+				max_pallet_num + 32,
+				if no_feature {
+					"If the feature does not exist - it needs to be implemented."
+				} else {
+					""
+				},
+			),
+		))
+	}
+
+	Ok(())
+}

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

@@ -0,0 +1,169 @@
+use frame_support::construct_runtime;
+use sp_core::sr25519;
+use sp_runtime::{generic, traits::BlakeTwo256};
+
+#[frame_support::pallet]
+mod pallet {
+	#[pallet::config]
+	pub trait Config: frame_system::Config {}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(core::marker::PhantomData<T>);
+}
+
+pub type Signature = sr25519::Signature;
+pub type BlockNumber = u32;
+pub type Header = generic::Header<BlockNumber, BlakeTwo256>;
+pub type Block = generic::Block<Header, UncheckedExtrinsic>;
+pub type UncheckedExtrinsic = generic::UncheckedExtrinsic<u32, RuntimeCall, Signature, ()>;
+
+impl pallet::Config for Runtime {}
+
+impl frame_system::Config for Runtime {
+	type BaseCallFilter = frame_support::traits::Everything;
+	type RuntimeOrigin = RuntimeOrigin;
+	type Index = u64;
+	type BlockNumber = u32;
+	type RuntimeCall = RuntimeCall;
+	type Hash = sp_runtime::testing::H256;
+	type Hashing = sp_runtime::traits::BlakeTwo256;
+	type AccountId = u64;
+	type Lookup = sp_runtime::traits::IdentityLookup<Self::AccountId>;
+	type Header = Header;
+	type RuntimeEvent = RuntimeEvent;
+	type BlockHashCount = frame_support::traits::ConstU32<250>;
+	type BlockWeights = ();
+	type BlockLength = ();
+	type DbWeight = ();
+	type Version = ();
+	type PalletInfo = PalletInfo;
+	type AccountData = ();
+	type OnNewAccount = ();
+	type OnKilledAccount = ();
+	type SystemWeightInfo = ();
+	type SS58Prefix = ();
+	type OnSetCode = ();
+	type MaxConsumers = frame_support::traits::ConstU32<16>;
+}
+
+construct_runtime! {
+	pub struct Runtime where
+		Block = Block,
+		NodeBlock = Block,
+		UncheckedExtrinsic = UncheckedExtrinsic
+	{
+		System: frame_system::{Pallet, Call, Storage, Config, Event<T>},
+		Pallet1: pallet::{Pallet},
+		Pallet2: pallet::{Pallet},
+		Pallet3: pallet::{Pallet},
+		Pallet4: pallet::{Pallet},
+		Pallet5: pallet::{Pallet},
+		Pallet6: pallet::{Pallet},
+		Pallet7: pallet::{Pallet},
+		Pallet8: pallet::{Pallet},
+		Pallet9: pallet::{Pallet},
+		Pallet10: pallet::{Pallet},
+		Pallet11: pallet::{Pallet},
+		Pallet12: pallet::{Pallet},
+		Pallet13: pallet::{Pallet},
+		Pallet14: pallet::{Pallet},
+		Pallet15: pallet::{Pallet},
+		Pallet16: pallet::{Pallet},
+		Pallet17: pallet::{Pallet},
+		Pallet18: pallet::{Pallet},
+		Pallet19: pallet::{Pallet},
+		Pallet20: pallet::{Pallet},
+		Pallet21: pallet::{Pallet},
+		Pallet22: pallet::{Pallet},
+		Pallet23: pallet::{Pallet},
+		Pallet24: pallet::{Pallet},
+		Pallet25: pallet::{Pallet},
+		Pallet26: pallet::{Pallet},
+		Pallet27: pallet::{Pallet},
+		Pallet28: pallet::{Pallet},
+		Pallet29: pallet::{Pallet},
+		Pallet30: pallet::{Pallet},
+		Pallet31: pallet::{Pallet},
+		Pallet32: pallet::{Pallet},
+		Pallet33: pallet::{Pallet},
+		Pallet34: pallet::{Pallet},
+		Pallet35: pallet::{Pallet},
+		Pallet36: pallet::{Pallet},
+		Pallet37: pallet::{Pallet},
+		Pallet38: pallet::{Pallet},
+		Pallet39: pallet::{Pallet},
+		Pallet40: pallet::{Pallet},
+		Pallet41: pallet::{Pallet},
+		Pallet42: pallet::{Pallet},
+		Pallet43: pallet::{Pallet},
+		Pallet44: pallet::{Pallet},
+		Pallet45: pallet::{Pallet},
+		Pallet46: pallet::{Pallet},
+		Pallet47: pallet::{Pallet},
+		Pallet48: pallet::{Pallet},
+		Pallet49: pallet::{Pallet},
+		Pallet50: pallet::{Pallet},
+		Pallet51: pallet::{Pallet},
+		Pallet52: pallet::{Pallet},
+		Pallet53: pallet::{Pallet},
+		Pallet54: pallet::{Pallet},
+		Pallet55: pallet::{Pallet},
+		Pallet56: pallet::{Pallet},
+		Pallet57: pallet::{Pallet},
+		Pallet58: pallet::{Pallet},
+		Pallet59: pallet::{Pallet},
+		Pallet60: pallet::{Pallet},
+		Pallet61: pallet::{Pallet},
+		Pallet62: pallet::{Pallet},
+		Pallet63: pallet::{Pallet},
+		Pallet64: pallet::{Pallet},
+		Pallet65: pallet::{Pallet},
+		Pallet66: pallet::{Pallet},
+		Pallet67: pallet::{Pallet},
+		Pallet68: pallet::{Pallet},
+		Pallet69: pallet::{Pallet},
+		Pallet70: pallet::{Pallet},
+		Pallet71: pallet::{Pallet},
+		Pallet72: pallet::{Pallet},
+		Pallet73: pallet::{Pallet},
+		Pallet74: pallet::{Pallet},
+		Pallet75: pallet::{Pallet},
+		Pallet76: pallet::{Pallet},
+		Pallet77: pallet::{Pallet},
+		Pallet78: pallet::{Pallet},
+		Pallet79: pallet::{Pallet},
+		Pallet80: pallet::{Pallet},
+		Pallet81: pallet::{Pallet},
+		Pallet82: pallet::{Pallet},
+		Pallet83: pallet::{Pallet},
+		Pallet84: pallet::{Pallet},
+		Pallet85: pallet::{Pallet},
+		Pallet86: pallet::{Pallet},
+		Pallet87: pallet::{Pallet},
+		Pallet88: pallet::{Pallet},
+		Pallet89: pallet::{Pallet},
+		Pallet90: pallet::{Pallet},
+		Pallet91: pallet::{Pallet},
+		Pallet92: pallet::{Pallet},
+		Pallet93: pallet::{Pallet},
+		Pallet94: pallet::{Pallet},
+		Pallet95: pallet::{Pallet},
+		Pallet96: pallet::{Pallet},
+		Pallet97: pallet::{Pallet},
+		Pallet98: pallet::{Pallet},
+		Pallet99: pallet::{Pallet},
+		Pallet100: pallet::{Pallet},
+		Pallet101: pallet::{Pallet},
+		Pallet102: pallet::{Pallet},
+		Pallet103: pallet::{Pallet},
+		Pallet104: pallet::{Pallet},
+		Pallet105: pallet::{Pallet},
+		Pallet106: pallet::{Pallet},
+		Pallet107: pallet::{Pallet},
+		Pallet108: pallet::{Pallet},
+		Pallet109: pallet::{Pallet},
+		Pallet110: pallet::{Pallet},
+	}
+}
+
+fn main() {}

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

@@ -0,0 +1,61 @@
+error: The number of pallets exceeds the maximum number of tuple elements. To increase this limit, enable the tuples-96 feature of [frame_support].
+  --> tests/construct_runtime_ui/number_of_pallets_exceeds_tuple_size.rs:50:2
+   |
+50 |     pub struct Runtime where
+   |     ^^^
+
+error[E0412]: cannot find type `RuntimeCall` in this scope
+  --> tests/construct_runtime_ui/number_of_pallets_exceeds_tuple_size.rs:18:64
+   |
+18 | pub type UncheckedExtrinsic = generic::UncheckedExtrinsic<u32, RuntimeCall, Signature, ()>;
+   |                                                                ^^^^^^^^^^^ not found in this scope
+   |
+help: you might be missing a type parameter
+   |
+18 | pub type UncheckedExtrinsic<RuntimeCall> = generic::UncheckedExtrinsic<u32, RuntimeCall, Signature, ()>;
+   |                            +++++++++++++
+
+error[E0412]: cannot find type `Runtime` in this scope
+  --> tests/construct_runtime_ui/number_of_pallets_exceeds_tuple_size.rs:20:25
+   |
+20 | impl pallet::Config for Runtime {}
+   |                         ^^^^^^^ not found in this scope
+
+error[E0412]: cannot find type `Runtime` in this scope
+  --> tests/construct_runtime_ui/number_of_pallets_exceeds_tuple_size.rs:22:31
+   |
+22 | impl frame_system::Config for Runtime {
+   |                               ^^^^^^^ not found in this scope
+
+error[E0412]: cannot find type `RuntimeOrigin` in this scope
+  --> tests/construct_runtime_ui/number_of_pallets_exceeds_tuple_size.rs:24:23
+   |
+24 |     type RuntimeOrigin = RuntimeOrigin;
+   |                          ^^^^^^^^^^^^^ help: you might have meant to use the associated type: `Self::RuntimeOrigin`
+
+error[E0412]: cannot find type `RuntimeCall` in this scope
+  --> tests/construct_runtime_ui/number_of_pallets_exceeds_tuple_size.rs:27:21
+   |
+27 |     type RuntimeCall = RuntimeCall;
+   |                        ^^^^^^^^^^^ help: you might have meant to use the associated type: `Self::RuntimeCall`
+
+error[E0412]: cannot find type `RuntimeEvent` in this scope
+  --> tests/construct_runtime_ui/number_of_pallets_exceeds_tuple_size.rs:33:22
+   |
+33 |     type RuntimeEvent = RuntimeEvent;
+   |                         ^^^^^^^^^^^^ help: you might have meant to use the associated type: `Self::RuntimeEvent`
+
+error[E0412]: cannot find type `PalletInfo` in this scope
+  --> tests/construct_runtime_ui/number_of_pallets_exceeds_tuple_size.rs:39:20
+   |
+39 |     type PalletInfo = PalletInfo;
+   |                       ^^^^^^^^^^
+   |
+help: you might have meant to use the associated type
+   |
+39 |     type PalletInfo = Self::PalletInfo;
+   |                       ~~~~~~~~~~~~~~~~
+help: consider importing this trait
+   |
+1  | use frame_support::traits::PalletInfo;
+   |