[xizheyin]

This pr introduce ModernIdent type to unify macro 2.0 hygiene handling

1. Added ModernIdent type. Wraps Ident and automatically calls normalize_to_macros_2_0()
2. Unified identifier normalization. Replaced scattered ident.normalize_to_macros_2_0() calls with ModernIdent::new(ident)

r? @petrochenkov

[rustbot]

HIR ty lowering was modified

cc @fmease

[fee1-dead]

What problem is this intended to solve? ModernIdent seems like a quite confusing name.

[petrochenkov]

In general, I have mixed feelings about both this and MacroRulesNormalizedIdent.
It clearly can potentially catch some mistakes or inefficiencies (like it did in fn define_macro, I think), on the other hand it can only be used opportunistically because most places either do not care about the normalization, or care but the normalization should be different in different cases (like in rib.bindings, I guess).

[xizheyin]

In this version, I removed some unnecessary uses.
The modifications are mainly centered around two fields.

1. BindingKey::ident
2. Resolver::extern_prelude

I rebased it @rustbot ready

It's getting clearer.

@rustbot ready

@bors r+

📌 Commit 6e7b9d5 has been approved by petrochenkov

It is now in the queue for this repository.

@rust-timer build b5d3bba

Finished benchmarking commit (b5d3bba): comparison URL.

Overall result: ❌✅ regressions and improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.0%	[0.0%, 0.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.3%	[-0.3%, -0.3%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (secondary 0.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	3.1%	[2.4%, 3.9%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.1%	[-3.2%, -3.1%]	2
All ❌✅ (primary)	-	-	0

Cycles

Results (primary 2.1%, secondary -1.7%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.1%	[1.8%, 2.4%]	2
Regressions ❌ (secondary)	3.2%	[2.3%, 4.4%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-4.1%	[-5.2%, -2.5%]	6
All ❌✅ (primary)	2.1%	[1.8%, 2.4%]	2

Binary size

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

Bootstrap: 465.283s -> 464.187s (-0.24%)
Artifact size: 377.41 MiB -> 377.33 MiB (-0.02%)