Create a more rigid overseer builder pattern that fails at compile time (#4753)

Introduces `Missing<Field>` and `Init<Field>` states, that are used in place of builder generics, and make this possible.
2026-05-30 10:31:03 +00:00 · 2022-02-09 16:01:16 +00:00
parent 227e39bff6
commit 84f55cc8d5
20 changed files with 891 additions and 267 deletions
@@ -1,5 +1,5 @@
 error[E0119]: conflicting implementations of trait `std::convert::From<MsgStrukt>` for type `AllMessages`
-  --> $DIR/err-01-duplicate-consumer.rs:19:1
+  --> tests/ui/err-01-duplicate-consumer.rs:19:1
   |
 19 | #[overlord(signal=SigSigSig, event=Event, gen=AllMessages, error=OverseerError)]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -10,7 +10,7 @@ error[E0119]: conflicting implementations of trait `std::convert::From<MsgStrukt
   = note: this error originates in the attribute macro `overlord` (in Nightly builds, run with -Z macro-backtrace for more info)

 error[E0119]: conflicting implementations of trait `polkadot_overseer_gen::SubsystemSender<MsgStrukt>` for type `OverseerSubsystemSender`
-  --> $DIR/err-01-duplicate-consumer.rs:19:1
+  --> tests/ui/err-01-duplicate-consumer.rs:19:1
   |
 19 | #[overlord(signal=SigSigSig, event=Event, gen=AllMessages, error=OverseerError)]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -0,0 +1,61 @@
+#![allow(dead_code)]
+
+use polkadot_overseer_gen::*;
+
+#[derive(Default)]
+struct AwesomeSubSys;
+
+impl ::polkadot_overseer_gen::Subsystem<OverseerSubsystemContext<MsgStrukt>, OverseerError> for AwesomeSubSys {
+	fn start(self, _ctx: OverseerSubsystemContext<MsgStrukt>) -> SpawnedSubsystem<OverseerError> {
+		unimplemented!("starting yay!")
+	}
+}
+
+#[derive(Clone, Debug)]
+pub struct SigSigSig;
+
+pub struct Event;
+
+#[derive(Clone, Debug)]
+pub struct MsgStrukt(u8);
+
+#[overlord(signal=SigSigSig, error=OverseerError, event=Event, gen=AllMessages)]
+struct Overseer {
+	#[subsystem(no_dispatch, MsgStrukt)]
+	sub0: AwesomeSubSys,
+	i_like_pie: f64,
+}
+
+#[derive(Debug, Clone)]
+pub struct DummySpawner;
+
+impl SpawnNamed for DummySpawner {
+	fn spawn_blocking(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		unimplemented!("spawn blocking {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+
+	fn spawn(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		unimplemented!("spawn {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+}
+
+struct DummyCtx;
+
+fn main() {
+	let _ = Overseer::builder()
+		.sub0(AwesomeSubSys::default())
+		//.i_like_pie(std::f64::consts::PI) // The filed is not initialised
+		.spawner(DummySpawner)
+		.build()
+		.unwrap();
+}
@@ -0,0 +1,15 @@
+error[E0599]: no method named `build` found for struct `OverseerBuilder<Init<DummySpawner>, Init<AwesomeSubSys>, Missing<f64>>` in the current scope
+  --> tests/ui/err-05-missing-field.rs:59:4
+   |
+22 | #[overlord(signal=SigSigSig, error=OverseerError, event=Event, gen=AllMessages)]
+   | -------------------------------------------------------------------------------- method `build` not found for this
+...
+59 |         .build()
+   |          ^^^^^ method not found in `OverseerBuilder<Init<DummySpawner>, Init<AwesomeSubSys>, Missing<f64>>`
+   |
+   = note: the method was found for
+           - `OverseerBuilder<Init<S>, Init<AwesomeSubSys>, Init<f64>>`
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following traits define an item `build`, perhaps you need to implement one of them:
+           candidate #1: `frame_support::traits::hooks::GenesisBuild`
+           candidate #2: `prometheus::vec::MetricVecBuilder`
@@ -0,0 +1,61 @@
+#![allow(dead_code)]
+
+use polkadot_overseer_gen::*;
+
+#[derive(Default)]
+struct AwesomeSubSys;
+
+impl ::polkadot_overseer_gen::Subsystem<OverseerSubsystemContext<MsgStrukt>, OverseerError> for AwesomeSubSys {
+	fn start(self, _ctx: OverseerSubsystemContext<MsgStrukt>) -> SpawnedSubsystem<OverseerError> {
+		unimplemented!("starting yay!")
+	}
+}
+
+#[derive(Clone, Debug)]
+pub struct SigSigSig;
+
+pub struct Event;
+
+#[derive(Clone, Debug)]
+pub struct MsgStrukt(u8);
+
+#[overlord(signal=SigSigSig, error=OverseerError, event=Event, gen=AllMessages)]
+struct Overseer {
+	#[subsystem(no_dispatch, MsgStrukt)]
+	sub0: AwesomeSubSys,
+	i_like_pie: f64,
+}
+
+#[derive(Debug, Clone)]
+pub struct DummySpawner;
+
+impl SpawnNamed for DummySpawner {
+	fn spawn_blocking(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		unimplemented!("spawn blocking {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+
+	fn spawn(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		unimplemented!("spawn {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+}
+
+struct DummyCtx;
+
+fn main() {
+	let _ = Overseer::builder()
+		//.sub0(AwesomeSubSys::default()) // Subsystem is uninitialized
+		.i_like_pie(std::f64::consts::PI)
+		.spawner(DummySpawner)
+		.build()
+		.unwrap();
+}
@@ -0,0 +1,15 @@
+error[E0599]: no method named `build` found for struct `OverseerBuilder<Init<DummySpawner>, Missing<_>, Init<f64>>` in the current scope
+  --> tests/ui/err-06-missing-subsystem.rs:59:4
+   |
+22 | #[overlord(signal=SigSigSig, error=OverseerError, event=Event, gen=AllMessages)]
+   | -------------------------------------------------------------------------------- method `build` not found for this
+...
+59 |         .build()
+   |          ^^^^^ method not found in `OverseerBuilder<Init<DummySpawner>, Missing<_>, Init<f64>>`
+   |
+   = note: the method was found for
+           - `OverseerBuilder<Init<S>, Init<AwesomeSubSys>, Init<f64>>`
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following traits define an item `build`, perhaps you need to implement one of them:
+           candidate #1: `frame_support::traits::hooks::GenesisBuild`
+           candidate #2: `prometheus::vec::MetricVecBuilder`
@@ -0,0 +1,61 @@
+#![allow(dead_code)]
+
+use polkadot_overseer_gen::*;
+
+#[derive(Default)]
+struct AwesomeSubSys;
+
+impl ::polkadot_overseer_gen::Subsystem<OverseerSubsystemContext<MsgStrukt>, OverseerError> for AwesomeSubSys {
+	fn start(self, _ctx: OverseerSubsystemContext<MsgStrukt>) -> SpawnedSubsystem<OverseerError> {
+		unimplemented!("starting yay!")
+	}
+}
+
+#[derive(Clone, Debug)]
+pub struct SigSigSig;
+
+pub struct Event;
+
+#[derive(Clone, Debug)]
+pub struct MsgStrukt(u8);
+
+#[overlord(signal=SigSigSig, error=OverseerError, event=Event, gen=AllMessages)]
+struct Overseer {
+	#[subsystem(no_dispatch, MsgStrukt)]
+	sub0: AwesomeSubSys,
+	i_like_pie: f64,
+}
+
+#[derive(Debug, Clone)]
+pub struct DummySpawner;
+
+impl SpawnNamed for DummySpawner {
+	fn spawn_blocking(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		unimplemented!("spawn blocking {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+
+	fn spawn(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		unimplemented!("spawn {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+}
+
+struct DummyCtx;
+
+fn main() {
+	let _ = Overseer::builder()
+		.sub0(AwesomeSubSys::default())
+		.i_like_pie(std::f64::consts::PI)
+		//.spawner(DummySpawner) // Spawner is missing
+		.build()
+		.unwrap();
+}
@@ -0,0 +1,15 @@
+error[E0599]: no method named `build` found for struct `OverseerBuilder<Missing<_>, Init<AwesomeSubSys>, Init<f64>>` in the current scope
+  --> tests/ui/err-07-missing-spawner.rs:59:4
+   |
+22 | #[overlord(signal=SigSigSig, error=OverseerError, event=Event, gen=AllMessages)]
+   | -------------------------------------------------------------------------------- method `build` not found for this
+...
+59 |         .build()
+   |          ^^^^^ method not found in `OverseerBuilder<Missing<_>, Init<AwesomeSubSys>, Init<f64>>`
+   |
+   = note: the method was found for
+           - `OverseerBuilder<Init<S>, Init<AwesomeSubSys>, Init<f64>>`
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following traits define an item `build`, perhaps you need to implement one of them:
+           candidate #1: `frame_support::traits::hooks::GenesisBuild`
+           candidate #2: `prometheus::vec::MetricVecBuilder`
@@ -0,0 +1,62 @@
+#![allow(dead_code)]
+
+use polkadot_overseer_gen::*;
+
+#[derive(Default)]
+struct AwesomeSubSys;
+
+impl ::polkadot_overseer_gen::Subsystem<OverseerSubsystemContext<MsgStrukt>, OverseerError> for AwesomeSubSys {
+	fn start(self, _ctx: OverseerSubsystemContext<MsgStrukt>) -> SpawnedSubsystem<OverseerError> {
+		unimplemented!("starting yay!")
+	}
+}
+
+#[derive(Clone, Debug)]
+pub struct SigSigSig;
+
+pub struct Event;
+
+#[derive(Clone, Debug)]
+pub struct MsgStrukt(u8);
+
+#[overlord(signal=SigSigSig, error=OverseerError, event=Event, gen=AllMessages)]
+struct Overseer {
+	#[subsystem(no_dispatch, MsgStrukt)]
+	sub0: AwesomeSubSys,
+	i_like_pie: f64,
+}
+
+#[derive(Debug, Clone)]
+pub struct DummySpawner;
+
+impl SpawnNamed for DummySpawner {
+	fn spawn_blocking(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		unimplemented!("spawn blocking {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+
+	fn spawn(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		unimplemented!("spawn {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+}
+
+struct DummyCtx;
+
+fn main() {
+	let _ = Overseer::builder()
+		.sub0(AwesomeSubSys::default())
+		.sub0(AwesomeSubSys::default()) // Duplicate subsystem
+		.i_like_pie(std::f64::consts::PI)
+		.spawner(DummySpawner)
+		.build()
+		.unwrap();
+}
@@ -0,0 +1,10 @@
+error[E0599]: no method named `sub0` found for struct `OverseerBuilder<Missing<_>, Init<AwesomeSubSys>, Missing<f64>>` in the current scope
+  --> tests/ui/err-08-duplicate-subsystem.rs:57:4
+   |
+22 | #[overlord(signal=SigSigSig, error=OverseerError, event=Event, gen=AllMessages)]
+   | -------------------------------------------------------------------------------- method `sub0` not found for this
+...
+57 |         .sub0(AwesomeSubSys::default()) // Duplicate subsystem
+   |          ^^^^-------------------------- help: remove the arguments
+   |          |
+   |          field, not a method
@@ -0,0 +1,61 @@
+#![allow(dead_code)]
+
+use polkadot_overseer_gen::*;
+
+#[derive(Default)]
+struct AwesomeSubSys;
+
+impl ::polkadot_overseer_gen::Subsystem<OverseerSubsystemContext<MsgStrukt>, OverseerError> for AwesomeSubSys {
+	fn start(self, _ctx: OverseerSubsystemContext<MsgStrukt>) -> SpawnedSubsystem<OverseerError> {
+		unimplemented!("starting yay!")
+	}
+}
+
+#[derive(Clone, Debug)]
+pub struct SigSigSig;
+
+pub struct Event;
+
+#[derive(Clone, Debug)]
+pub struct MsgStrukt(u8);
+
+#[overlord(signal=SigSigSig, error=OverseerError, event=Event, gen=AllMessages)]
+struct Overseer<T> {
+	#[subsystem(no_dispatch, MsgStrukt)]
+	sub0: AwesomeSubSys,
+	i_like_pie: T,
+}
+
+#[derive(Debug, Clone)]
+pub struct DummySpawner;
+
+impl SpawnNamed for DummySpawner {
+	fn spawn_blocking(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		unimplemented!("spawn blocking {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+
+	fn spawn(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		unimplemented!("spawn {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+}
+
+struct DummyCtx;
+
+fn main() {
+	let (_, _): (Overseer<_, f64>, _) = Overseer::builder()
+		.sub0(AwesomeSubSys::default())
+		//.i_like_pie(std::f64::consts::PI) // The filed is not initialised
+		.spawner(DummySpawner)
+		.build()
+		.unwrap();
+}
@@ -0,0 +1,15 @@
+error[E0599]: no method named `build` found for struct `OverseerBuilder<Init<DummySpawner>, Init<AwesomeSubSys>, Missing<_>>` in the current scope
+  --> tests/ui/err-09-uninit_generic_baggage.rs:59:4
+   |
+22 | #[overlord(signal=SigSigSig, error=OverseerError, event=Event, gen=AllMessages)]
+   | -------------------------------------------------------------------------------- method `build` not found for this
+...
+59 |         .build()
+   |          ^^^^^ method not found in `OverseerBuilder<Init<DummySpawner>, Init<AwesomeSubSys>, Missing<_>>`
+   |
+   = note: the method was found for
+           - `OverseerBuilder<Init<S>, Init<AwesomeSubSys>, Init<T>>`
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following traits define an item `build`, perhaps you need to implement one of them:
+           candidate #1: `frame_support::traits::hooks::GenesisBuild`
+           candidate #2: `prometheus::vec::MetricVecBuilder`
@@ -0,0 +1,75 @@
+#![allow(dead_code)]
+
+use polkadot_overseer_gen::*;
+
+#[derive(Default)]
+struct AwesomeSubSysA;
+
+
+impl ::polkadot_overseer_gen::Subsystem<OverseerSubsystemContext<MsgA>, OverseerError> for AwesomeSubSysA {
+	fn start(self, _ctx: OverseerSubsystemContext<MsgA>) -> SpawnedSubsystem<OverseerError> {
+		SpawnedSubsystem { name: "sub A", future: Box::pin(async move { Ok(()) }) }
+	}
+}
+impl ::polkadot_overseer_gen::Subsystem<OverseerSubsystemContext<MsgB>, OverseerError> for AwesomeSubSysB {
+	fn start(self, _ctx: OverseerSubsystemContext<MsgB>) -> SpawnedSubsystem<OverseerError> {
+		SpawnedSubsystem { name: "sub B", future: Box::pin(async move { Ok(()) }) }
+	}
+}
+
+#[derive(Debug, Clone)]
+pub struct DummySpawner;
+
+impl SpawnNamed for DummySpawner {
+	fn spawn_blocking(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		println!("spawn blocking {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+
+	fn spawn(
+		&self,
+		task_name: &'static str,
+		subsystem_name: Option<&'static str>,
+		_future: futures::future::BoxFuture<'static, ()>,
+	) {
+		println!("spawn {} {}", task_name, subsystem_name.unwrap_or("default"))
+	}
+}
+
+#[derive(Default)]
+struct AwesomeSubSysB;
+
+#[derive(Clone, Debug)]
+pub struct SigSigSig;
+
+pub struct Event;
+
+#[derive(Clone, Debug)]
+pub struct MsgA(u8);
+
+#[derive(Clone, Debug)]
+pub struct MsgB(u8);
+
+#[overlord(signal=SigSigSig, event=Event, gen=AllMessages, error=OverseerError)]
+pub struct Overseer {
+	#[subsystem(MsgA)]
+	sub_a: AwesomeSubSysA,
+
+	#[subsystem(wip, MsgB)]
+	sub_b: AwesomeSubSysB,
+}
+
+pub struct DummyCtx;
+
+fn main() {
+	let _overseer_builder = Overseer::builder()
+		.sub_a(AwesomeSubSysA::default())
+		// b is tagged as `wip`
+		// .sub_b(AwesomeSubSysB::default())
+		.spawner(DummySpawner)
+		.build();
+}