Record allocation spans inside force_allocation

[saethlin]

This expands rust-lang/miri#2940 to cover locals

r? @RalfJung

[rustbot]

Some changes occurred to the CTFE / Miri engine

cc @rust-lang/miri

The Miri subtree was changed

cc @rust-lang/miri

[RalfJung]

Thanks, looks great overall with minor nits!

Can you confirm that if you use current_span instead, at least one of the tests changes its output?

[saethlin]

Can you confirm that if you use current_span instead, at least one of the tests changes its output?

Their output does change, but not in a way that is meaningful. They highlight the span of the expression for the rvalue in the let, instead of the variable name. I'm adding a more direct test for the span selection.

[RalfJung]

Thanks!

One of my comments is still unresolved I think.

[RalfJung]

Looks good, thanks!
@bors r+

[bors]

📌 Commit 8ecdefb has been approved by RalfJung

It is now in the queue for this repository.

[bors]

⌛ Testing commit 8ecdefb with merge 296c7a6...

[bors]

☀️ Test successful - checks-actions
Approved by: RalfJung
Pushing 296c7a6 to master...

[rust-timer]

Finished benchmarking commit (296c7a6): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.5%	[-2.5%, -2.5%]	1
All ❌✅ (primary)	-	-	0

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 632.601s -> 629.829s (-0.44%)
Artifact size: 315.72 MiB -> 315.71 MiB (-0.01%)