Avoid specialization in the metadata serialization code
With the exception of a perf-only specialization for byte slices and byte vectors.
This uses the same trick of introducing a new trait and having the Encodable and Decodable derives add a bound to it as used for TyEncoder/TyDecoder. The new code is clearer about which encoder/decoder uses which impl and it reduces the dependency of rustc on specialization, making it easier to remove support for specialization entirely or turn it into a construct that is only allowed for perf optimizations if we decide to do this.
Rollup of 9 pull requests
Successful merges:
- #119208 (coverage: Hoist some complex code out of the main span refinement loop)
- #119216 (Use diagnostic namespace in stdlib)
- #119414 (bootstrap: Move -Clto= setting from Rustc::run to rustc_cargo)
- #119420 (Handle ForeignItem as TAIT scope.)
- #119468 (rustdoc-search: tighter encoding for f index)
- #119628 (remove duplicate test)
- #119638 (fix cyle error when suggesting to use associated function instead of constructor)
- #119640 (library: Fix warnings in rtstartup)
- #119642 (library: Fix a symlink test failing on Windows)
r? `@ghost`
`@rustbot` modify labels: rollup
fix cyle error when suggesting to use associated function instead of constructor
Fixes https://github.com/rust-lang/rust/issues/119625.
The first commit fixes the infinite recursion and makes the cycle error actually show up. We do this by making the `Display` for `ty::Instance` impl respect `with_no_queries` so that it can be used in query descriptions.
The second commit fixes the cycle error `resolver_for_lowering` -> `normalize` -> `resolve_instance` (for evaluating const) -> `lang_items` (for `drop_in_place`) -> `resolver_for_lowering` (for collecting lang items). We do this by simply skipping the suggestion when encountering an unnormalized type.
remove duplicate test
This was added in ace6fc3646 where overflowing-rsh-6 differed from overflowing-rsh-5 in a feature gate, but the feature has since been stabilized, making the tests 100% identical.
Most of these tests in numbers-arithmetic could be put into one file rather than having so many files that all test the same lint... but it doesn't seem worth the effort. After https://github.com/rust-lang/rust/pull/119432 we might be able to remove most of them entirely as they will be covered by the new tests added there.
rustdoc-search: tighter encoding for f index
Depends on https://github.com/rust-lang/rust/pull/119457
Two optimizations for the function signature search:
* Instead of using JSON arrays, like `[1,20]`, it uses VLQ
hex with no commas, like `[aAd]`.
* This also adds backrefs: if you have more than one function
with exactly the same signature, it'll not only store it once,
it'll *decode* it once, and store in the typeIdMap only once.
Based partially on discussions on zulip:
https://rust-lang.zulipchat.com/#narrow/stream/266220-t-rustdoc/topic/search.20index.20size
Performance
-----------
https://notriddle.com/rustdoc-html-demo-8/compression-perf-v2/index.html
### memory/time profiler output (for more details, consult the above link)
<table>
<thead><tr><th>benchmark<th>before<th>after</tr></thead>
<tbody>
<tr><th>arti<td>
```
user: 002.789 s
sys: 000.390 s
wall: 002.096 s
child_RSS_high: 440796 KiB
group_mem_high: 414924 KiB
```
</td><td>
```
user: 002.295 s
sys: 000.278 s
wall: 001.738 s
child_RSS_high: 314588 KiB
group_mem_high: 285220 KiB
```
</td></tr><tr><th>cortex-m<td>
```
user: 000.127 s
sys: 000.030 s
wall: 000.134 s
child_RSS_high: 60264 KiB
group_mem_high: 23824 KiB
```
</td><td>
```
user: 000.136 s
sys: 000.038 s
wall: 000.137 s
child_RSS_high: 59204 KiB
group_mem_high: 22712 KiB
```
</td></tr><tr><th>sqlx<td>
```
user: 000.887 s
sys: 000.118 s
wall: 000.592 s
child_RSS_high: 190408 KiB
group_mem_high: 157804 KiB
```
</td><td>
```
user: 000.798 s
sys: 000.101 s
wall: 000.525 s
child_RSS_high: 159292 KiB
group_mem_high: 126292 KiB
```
</td></tr><tr><th>stm32f4<td>
```
user: 013.884 s
sys: 005.399 s
wall: 013.149 s
child_RSS_high: 1942244 KiB
group_mem_high: 1954916 KiB
```
</td><td>
```
user: 006.128 s
sys: 003.297 s
wall: 007.994 s
child_RSS_high: 1038108 KiB
group_mem_high: 1023900 KiB
```
</td></tr><tr><th>ripgrep<td>
```
user: 000.441 s
sys: 000.063 s
wall: 000.264 s
child_RSS_high: 109180 KiB
group_mem_high: 74272 KiB
```
</td><td>
```
user: 000.408 s
sys: 000.044 s
wall: 000.238 s
child_RSS_high: 101488 KiB
group_mem_high: 66000 KiB
```
</td></tr></tbody></table>
Size change
-----------
standard library without gzip:
```console
$ du -bs search-index-old.js search-index-new.js
4976370 search-index-old.js
4404391 search-index-new.js
```
((4976370-4404391)/4404391)*100% = 12.9%
with gzip:
```console
$ du -hs search-index-old.js.gz search-index-new.js.gz
520K search-index-old.js.gz
504K search-index-new.js.gz
$ du -bs search-index-old.js.gz search-index-new.js.gz
522092 search-index-old.js.gz
507654 search-index-new.js.gz
```
((522092-507654)/507654)*100% = 2.8%
Benchmarks are similarly shrunk.
Without gzip:
```console
$ du -hs tmp/{arti,cortex-m,sqlx,stm32f4,ripgrep}/toolchain_{old,new}/doc/search-index.js
10555067 tmp/arti/toolchain_old/doc/search-index.js
8921236 tmp/arti/toolchain_new/doc/search-index.js
77018 tmp/cortex-m/toolchain_old/doc/search-index.js
66676 tmp/cortex-m/toolchain_new/doc/search-index.js
2876330 tmp/sqlx/toolchain_old/doc/search-index.js
2436812 tmp/sqlx/toolchain_new/doc/search-index.js
63632890 tmp/stm32f4/toolchain_old/doc/search-index.js
52337438 tmp/stm32f4/toolchain_new/doc/search-index.js
631150 tmp/ripgrep/toolchain_old/doc/search-index.js
541646 tmp/ripgrep/toolchain_new/doc/search-index.js
```
With gzip:
```console
$ du -bs tmp/{arti,cortex-m,sqlx,stm32f4,ripgrep}/toolchain_{old,new}/doc/search-index.js.gz
1618852 tmp/arti/toolchain_old/doc/search-index.js.gz
1582007 tmp/arti/toolchain_new/doc/search-index.js.gz
16109 tmp/cortex-m/toolchain_old/doc/search-index.js.gz
15831 tmp/cortex-m/toolchain_new/doc/search-index.js.gz
422257 tmp/sqlx/toolchain_old/doc/search-index.js.gz
411507 tmp/sqlx/toolchain_new/doc/search-index.js.gz
4454761 tmp/stm32f4/toolchain_old/doc/search-index.js.gz
4334924 tmp/stm32f4/toolchain_new/doc/search-index.js.gz
98312 tmp/ripgrep/toolchain_old/doc/search-index.js.gz
96864 tmp/ripgrep/toolchain_new/doc/search-index.js.gz
$ du -hs tmp/{arti,cortex-m,sqlx,stm32f4,ripgrep}/toolchain_{old,new}/doc/search-index.j
s.gz
1.6M tmp/arti/toolchain_old/doc/search-index.js.gz
1.6M tmp/arti/toolchain_new/doc/search-index.js.gz
24K tmp/cortex-m/toolchain_old/doc/search-index.js.gz
24K tmp/cortex-m/toolchain_new/doc/search-index.js.gz
424K tmp/sqlx/toolchain_old/doc/search-index.js.gz
412K tmp/sqlx/toolchain_new/doc/search-index.js.gz
4.3M tmp/stm32f4/toolchain_old/doc/search-index.js.gz
4.2M tmp/stm32f4/toolchain_new/doc/search-index.js.gz
108K tmp/ripgrep/toolchain_old/doc/search-index.js.gz
104K tmp/ripgrep/toolchain_new/doc/search-index.js.gz
```
bootstrap: Move -Clto= setting from Rustc::run to rustc_cargo
It prevents a full rebuild of stage 1 compiler when issuing "x.py test" with rust.lto != thin-local in config.toml.
Use diagnostic namespace in stdlib
This required a minor fix to have the diagnostics shown in third party crates when the `diagnostic_namespace` feature is not enabled. See 5d63f5d8d1 for details. I've opted for having a single PR for both changes as it's really not that much code. If it is required it should be easy to split up the change into several PR's.
r? `@compiler-errors`
coverage: Hoist some complex code out of the main span refinement loop
The span refinement loop in `spans.rs` takes the spans that have been extracted from MIR, and modifies them to produce more helpful output in coverage reports.
It is also one of the most complicated pieces of code in the coverage instrumentor. It has an abundance of moving pieces that make it difficult to understand, and most attempts to modify it end up accidentally changing its behaviour in unacceptable ways.
This PR nevertheless tries to make a dent in it by hoisting two pieces of special-case logic out of the main loop, and into separate preprocessing passes. Coverage tests show that the resulting mappings are *almost* identical, with all known differences being unimportant.
This should hopefully unlock further simplifications to the refinement loop, since it now has fewer edge cases to worry about.
Exhaustiveness: Statically enforce revealing of opaques
In https://github.com/rust-lang/rust/pull/116821 it was decided that exhaustiveness should operate on the hidden type of an opaque type when relevant. This PR makes sure we consistently reveal opaques within exhaustiveness. This makes it possible to remove `reveal_opaque_ty` from the `TypeCx` trait which was an unfortunate implementation detail.
r? `@compiler-errors`
Rollup of 8 pull requests
Successful merges:
- #119151 (Hide foreign `#[doc(hidden)]` paths in import suggestions)
- #119350 (Imply outlives-bounds on lazy type aliases)
- #119354 (Make `negative_bounds` internal & fix some of its issues)
- #119506 (Use `resolutions(()).effective_visiblities` to avoid cycle errors in `report_object_error`)
- #119554 (Fix scoping for let chains in match guards)
- #119563 (Check yield terminator's resume type in borrowck)
- #119589 (cstore: Remove unnecessary locking from `CrateMetadata`)
- #119622 (never patterns: Document behavior of never patterns with macros-by-example)
r? `@ghost`
`@rustbot` modify labels: rollup
By using FxIndexMap instead of FxHashMap, so that the order of visiting
of locals is deterministic.
We also need to bless
copy_propagation_arg.foo.DestinationPropagation.panic*.diff. Do not
review the diff of the diff. Instead look at the diff file before and
after this commit. Both before and after this commit, 3 statements are
replaced with nop. It's just that due to change in ordering, different
statements are replaced. But the net result is the same.
never patterns: Document behavior of never patterns with macros-by-example
`never_patterns` makes `!` parse as a pattern so I was worried about breaking macros-by-example matching. Turns out we're fine because the cases that now match `$p:pat` used to error in the past. The only tricky case is `!` by itself, which backwards-compatibly doesn't match `$p:pat`. I have no idea why tho, I didn't think of that when I was implementing parsing 😅.
This adds tests so we don't regress the current behavior.
r? `@compiler-errors`
cstore: Remove unnecessary locking from `CrateMetadata`
Locks and atomics in `CrateMetadata` fields were necessary before https://github.com/rust-lang/rust/pull/107765 when `CStore` was cloneable, but now they are not necessary and can be removed after restructuring the code a bit to please borrow checker.
All remaining locked fields in `CrateMetadata` are lazily populated caches.
Check yield terminator's resume type in borrowck
In borrowck, we didn't check that the lifetimes of the `TerminatorKind::Yield`'s `resume_place` were actually compatible with the coroutine's signature. That means that the lifetimes were totally going unchecked. Whoops!
This PR implements this checking.
Fixes#119564
r? types
Fix scoping for let chains in match guards
If let guards were previously represented as a different type of guard in HIR and THIR. This meant that let chains in match guards were not handled correctly because they were treated exactly like normal guards.
- Remove `hir::Guard` and `thir::Guard`.
- Make the scoping different between normal guards and if let guards also check for let chains.
closes#118593
Use `resolutions(()).effective_visiblities` to avoid cycle errors in `report_object_error`
Inside of `report_object_error`, using the `effective_visibilities` query causes cycles since it calls `type_of`, which itself may call `typeck`, which may end up reporting its own object-safety errors.
Fixes#119346Fixes#119502
Hide foreign `#[doc(hidden)]` paths in import suggestions
Stops the compiler from suggesting to import foreign `#[doc(hidden)]` paths.
```@rustbot``` label A-suggestion-diagnostics
Replace a number of FxHashMaps/Sets with stable-iteration-order alternatives
This PR replaces almost all of the remaining `FxHashMap`s in query results with either `FxIndexMap` or `UnordMap`. The only case that is missing is the `EffectiveVisibilities` struct which turned out to not be straightforward to transform. Once that is done too, we can remove the `HashStable` implementation from `HashMap`.
The first commit adds the `StableCompare` trait which is a companion trait to `StableOrd`. Some types like `Symbol` can be compared in a cross-session stable way, but their `Ord` implementation is not stable. In such cases, a `StableCompare` implementation can be provided to offer a lightweight way for stable sorting. The more heavyweight option is to sort via `ToStableHashKey`, but then sorting needs to have access to a stable hashing context and `ToStableHashKey` can also be expensive as in the case of `Symbol` where it has to allocate a `String`.
The rest of the commits are rather mechanical and don't overlap, so they are best reviewed individually.
Part of [MCP 533](https://github.com/rust-lang/compiler-team/issues/533).
In the past it did create a fresh expansion, but now, after surviving a number of refactorings, it does not.
Now it's just a thin wrapper around `apply_mark`.
Move `i586-unknown-netbsd` from tier 2 to tier 3 platform support table
It appears it was intended to be tier 3, but was accidentally added to tier 2. Based on inspecting the PR adding it the table https://github.com/rust-lang/rust/pull/117170 and the fact that it is not built in CI which is one of the tier 2 requirements.
cc ````@he32````
r? ````@Nilstrieb````
[rustdoc] Fix invalid handling for static method calls in jump to definition feature
I realized when working on a clippy lint that static method calls on `Self` could not give me the method `Res`. For that, we need to use `typeck` and so that's what I did in here.
It fixes the linking to static method calls.
r? ````@notriddle````
Migrate memory overlap check from validator to lint
The check attempts to identify potential undefined behaviour, rather
than whether MIR is well-formed. It belongs in the lint not validator.
Follow up to changes from #119077.
Remove `-Zreport-delayed-bugs`.
It's not used within the repository in any way (e.g. in tests), and doesn't seem useful.
It was added in #52568.
r? ````@oli-obk````
