Replace QueryStruct with arrays local to rustc_query_impl

[Zoxc]

This removes QueryStruct and instead uses constant arrays of function pointers for try_collect_active_jobs, alloc_self_profile_query_strings and encode_query_results. This further decouples rustc_query_impl from rustc_middle.

r? @cjgillot

[cjgillot]

Could you add a comment saying that those arrays are not indexed per DepKind, so should only be used for iteration?

[cjgillot]

Thanks. One nit and r=me.

[cjgillot]

Can this use item_if_cached? Like this:

Suggested change

	] = &[$(expand_if_cached!([$($modifiers)*], query_impl::$name::encode_query_results)),*];
	] = &[$( item_if_cached!([$($modifiers)*], query_impl::$name::encode_query_results, ))*];

This will allow to remove the option.

[Zoxc]

The macro has to expand to a single expression, so it's not quite that simple.

[cjgillot]

@bors r+

[bors]

📌 Commit aa5d436 has been approved by cjgillot

It is now in the queue for this repository.

[bors]

⌛ Testing commit aa5d436 with merge 2440cca...

[bors]

☀️ Test successful - checks-actions
Approved by: cjgillot
Pushing 2440cca to master...

[rust-timer]

Finished benchmarking commit (2440cca): 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)	2.8%	[2.8%, 2.8%]	1
Improvements ✅ (primary)	-3.8%	[-3.9%, -3.6%]	2
Improvements ✅ (secondary)	-3.8%	[-4.1%, -3.3%]	4
All ❌✅ (primary)	-3.8%	[-3.9%, -3.6%]	2

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)	-	-	0
Improvements ✅ (secondary)	-2.0%	[-2.0%, -2.0%]	1
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 644.264s -> 643.64s (-0.10%)