Add separate feature gate for async fn track caller

[bryangarza]

This patch adds a feature gate async_fn_track_caller that is separate from closure_track_caller. This is to allow enabling async_fn_track_caller separately.

Fixes #110009

[rustbot]

r? @wesleywiser

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[bryangarza]

@rustbot author

[bryangarza]

One thing I'm not sure is if I should be updating this line that sets allow_gen_future:

rust/compiler/rustc_ast_lowering/src/item.rs

Line 85 in e6d4725

allow_gen_future: Some([sym::gen_future, sym::closure_track_caller][..].into()),

It's used here:
https://github.com/rust-lang/rust/blob/18de7625ce234a0ac6d789bb358885f9ac8a64f2/compiler/rustc_ast_lowering/src/expr.rs#L663-L664

The tests pass as-is, but I'm not sure if I should have to reference the new feature gate inside of allow_gen_future.

[compiler-errors]

Why is this using cls and not afn? This is an async block -- shouldn't it only work when async_fn_track_caller is enabled?

[compiler-errors]

Well, I guess it's separate.

[bryangarza]

yeah it's separate, this case is still gated by closure_track_caller

[compiler-errors]

Can you add more tests to make sure, e.g., nested closures inside of async fns don't accidentally allow #[track_caller] with just the async_fn_track_caller feature gate?

[bryangarza]

Can you add more tests to make sure, e.g., nested closures inside of async fns don't accidentally allow #[track_caller] with just the async_fn_track_caller feature gate?

@compiler-errors I now updated async-block.rs and async-closure-gate.rs now with a couple more cases, is that what you had in mind?

[compiler-errors]

Also while we're at it, that line you mentioned:

allow_gen_future: Some([sym::gen_future, sym::closure_track_caller][..].into()),

We could actually be even more conservative and change it so that we only add sym::closure_track_caller if tcx.features().async_fn_track_caller is active... 🤔

[bryangarza]

@rustbot ready

[compiler-errors]

@bors r+

[bors]

📌 Commit b9e395fd4e612742d7d41542fbbe2a80eb9b95d7 has been approved by compiler-errors

It is now in the queue for this repository.

[bors]

⌛ Testing commit b9e395fd4e612742d7d41542fbbe2a80eb9b95d7 with merge ea47e718b84c05a876f43cd313e78683bdfd7cca...

[bors]

💔 Test failed - checks-actions

[compiler-errors]

@bryangarza you need to bless ui tests

@rustbot author

[bryangarza]

@rustbot ready

[compiler-errors]

@bors r+

[bors]

📌 Commit 673ab17 has been approved by compiler-errors

It is now in the queue for this repository.

[bors]

⌛ Testing commit 673ab17 with merge e173a8e...

[bors]

☀️ Test successful - checks-actions
Approved by: compiler-errors
Pushing e173a8e to master...

[rust-timer]

Finished benchmarking commit (e173a8e): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.7%	[-1.2%, -0.4%]	36
Improvements ✅ (secondary)	-0.6%	[-0.9%, -0.2%]	10
All ❌✅ (primary)	-0.7%	[-1.2%, -0.4%]	36

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.4%	[1.0%, 1.8%]	3
Regressions ❌ (secondary)	2.2%	[1.7%, 2.5%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.0%	[-3.1%, -1.4%]	4
All ❌✅ (primary)	1.4%	[1.0%, 1.8%]	3

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.1%	[-2.1%, -2.1%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.1%	[-2.1%, -2.1%]	1

Binary size

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.1%	[-0.1%, -0.1%]	9
All ❌✅ (primary)	-	-	0

Bootstrap: 650.779s -> 650.501s (-0.04%)