Commit Graph

948 Commits

Author SHA1 Message Date
Vadim Petrochenkov
fd73d01c98 rustc_resolve: Remove Resolver::clone_output
And remove `Clone` impls and `Lrc`s that are no longer necessary
2023-02-13 00:10:15 +04:00
Vadim Petrochenkov
9080b79f2b rustdoc: Eliminate remaining uses of resolver 2023-02-13 00:10:15 +04:00
bors
51cb5614dd Auto merge of #105601 - BelovDV:change-rlib-with-not-stable, r=petrochenkov
Enable new rlib in non stable cases

If bundled static library uses cfg (unstable) or whole-archive (wasn't supported) bundled libs are packed even without packed_bundled_libs.

r? `@petrochenkov`
2023-02-12 07:15:27 +00:00
Daniil Belov
601fc8b36b [link] enable packed bundled lib in non stable cases 2023-02-10 12:51:12 +03:00
Vadim Petrochenkov
b62b82aef4 Resolve documentation links in rustc and store the results in metadata
This commit implements MCP https://github.com/rust-lang/compiler-team/issues/584

It also removes code that is no longer used, and that includes code cloning resolver, so issue #83761 is fixed.
2023-02-10 09:34:13 +04:00
Matthias Krüger
6d225bb080
Rollup merge of #100599 - MatthewPeterKelly:add-E0523-description-and-test, r=compiler-errors,GuillaumeGomez
Add compiler error E0523 long description and test

This PR is one step towards addressing:  https://github.com/rust-lang/rust/issues/61137.
2023-02-07 17:57:13 +01:00
Matthew Kelly
2bcd4e256a Add extended error message for E0523
Adds the extended error documentation for E0523 to indicate that the
error is no longer produced by the compiler.

Update the E0464 documentation to include example code that produces the
error.

Remove the error message E0523 from the compiler and replace it with an
internal compiler error.
2023-02-06 06:58:30 -05:00
Vadim Petrochenkov
f4e2b954a1 rustc_metadata: Encode/decode DefPathHashes without an Option 2023-02-05 18:53:47 +04:00
Vadim Petrochenkov
c60cc43985 rustc_metadata: Encode/decode some LazyArrays without an Option
Also add asserts to decoding `LazyArray`s with `Option`
2023-02-05 18:19:52 +04:00
Vadim Petrochenkov
eb5f2d3980 rustc_metadata: Support encoding/decoding LazyArray without an Option 2023-02-05 18:19:52 +04:00
Vadim Petrochenkov
8cc5aa561c rustc_metadata: Refactor lazy table reading/writing
Change wording from "nullable" to "default".
Introduce a trait `IsDefault` for detecting values that are encoded as zeros or not encoded at all.
Add panics to impossible cases.
Some other minor cleanups.
2023-02-05 18:19:52 +04:00
est31
4442f13b03 rustc_metadata: remove huge error imports 2023-02-05 03:47:38 +01:00
Michael Woerister
227b2858da Retry opening proc-macro DLLs a few times on Windows. 2023-02-02 16:18:16 +01:00
Guillaume Gomez
53bb6322db
Rollup merge of #107467 - WaffleLapkin:uneq, r=oli-obk
Improve enum checks

Some light refactoring.
2023-01-31 23:38:52 +01:00
Maybe Waffle
f1d273cbfb Replace some _ == _ || _ == _s with matches!(_, _ | _)s 2023-01-30 12:26:26 +00:00
Maybe Waffle
fd649a3cc5 Replace enum ==s with matches where it makes sense 2023-01-30 12:26:26 +00:00
Camille GILLOT
1d3f5b49d6 Test drop_tracking_mir before querying generator. 2023-01-29 13:50:07 +00:00
bors
bcb064a7f4 Auto merge of #107406 - cjgillot:eliminate-witnesses, r=compiler-errors
Only compute mir_generator_witnesses query in drop_tracking_mir mode.

Attempt to fix the perf regression in https://github.com/rust-lang/rust/pull/101692

r? `@ghost`
2023-01-29 01:27:11 +00:00
Camille GILLOT
15d6325747 Remove HirId -> LocalDefId map from HIR. 2023-01-28 09:55:26 +00:00
Camille GILLOT
4db4860503 Only compute mir_generator_witnesses query in drop_tracking_mir mode. 2023-01-28 08:41:22 +00:00
Camille GILLOT
400cb9aa41 Separate witness type computation from the generator transform. 2023-01-27 19:00:26 +00:00
bors
7919ef0ec5 Auto merge of #107055 - kylematsuda:eb-fn-sig, r=lcnr
Switch to `EarlyBinder` for `fn_sig` query

Part of the work to finish #105779 (also see https://github.com/rust-lang/types-team/issues/78).

Several queries `X` have a `bound_X` variant that wraps the output in [`EarlyBinder`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/subst/struct.EarlyBinder.html). This adds `EarlyBinder` to the return type of the `fn_sig` query and removes `bound_fn_sig`.

r? `@lcnr`
2023-01-27 15:02:44 +00:00
bors
6874f4e3fc Auto merge of #107054 - petrochenkov:effvisdoc3, r=GuillaumeGomez
rustdoc: Collect "rustdoc-reachable" items during early doc link resolution

This pass only needs to know about visibilities, attributes and reexports, so it can be run early, similarly to `compute_effective_visibilities` in rustc.
Results of this pass can be used to prune the list of extern impls early thus improving performance of https://github.com/rust-lang/rust/pull/94857.
2023-01-27 09:01:05 +00:00
Yuki Okushi
eb5e63e3f0
Rollup merge of #107171 - petrochenkov:encattrs, r=cjgillot
rustc_metadata: Fix `encode_attrs`

This function didn't do what the authors intended it to do.

- Due to `move` in the closure `is_public` wasn't captured by mutalbe reference and wasn't used as a cache.
- Due to iterator cloning all the `should_encode_attr` logic run for the second time to calculate `may_have_doc_links`

This PR fixes these issues, and calculates all the needed attribute flags in one go.

(Noticed while implementing https://github.com/rust-lang/rust/pull/107136.)
2023-01-27 12:57:54 +09:00
Kyle Matsuda
c2414dfaa4 change fn_sig query to use EarlyBinder; remove bound_fn_sig query; add EarlyBinder to fn_sig in metadata 2023-01-26 20:28:25 -07:00
Kyle Matsuda
e982971ff2 replace usages of fn_sig query with bound_fn_sig 2023-01-26 20:15:36 -07:00
Matthias Krüger
82455a799e
Rollup merge of #107189 - cjgillot:meta-adt, r=compiler-errors
Encode info for Adt in a single place.

Split from https://github.com/rust-lang/rust/pull/98867
2023-01-26 15:02:21 +01:00
Vadim Petrochenkov
957bc606dd rustdoc: Collect rustdoc-reachable items during early doc link resolution 2023-01-25 23:14:09 +04:00
Vadim Petrochenkov
c70b7aafae rustc_metadata: Fix encode_attrs
This function didn't do what the authors intended it to do.

- Due to `move` in the closure `is_public` wasn't captured by mutalbe reference and wasn't used as a cache.
- Due to iterator cloning all the `should_encode_attr` logic run for the second time to calculate `may_have_doc_links`

This PR fixes these issues, and calculates all the needed attribute flags in one go.
2023-01-25 10:08:48 +04:00
Vadim Petrochenkov
91fdbd7343 rustc_metadata: Support non-Option nullable values in metadata tables
This is a convenience feature for cases in which "no value in the table" and "default value in the table" are equivalent.
Tables using `Table<DefIndex, ()>` are migrated in this PR, some other cases can be migrated later.

This helps `DocFlags` in https://github.com/rust-lang/rust/pull/107136 in particular.
2023-01-23 19:35:03 +04:00
Camille GILLOT
4d11206ee7 Tweak comments. 2023-01-22 11:13:19 +00:00
Camille GILLOT
6ecf30d67d Inline encode_enum_variant_info. 2023-01-22 11:04:53 +00:00
Camille GILLOT
d7f6564fdd Encode AdtDef in the def-id loop. 2023-01-22 11:04:52 +00:00
Vadim Petrochenkov
415c14129b rustc_metadata: Encode doc(hidden) flag to metadata
To retrieve these flags rustdoc currently has to mass decode full attributes for items in the whole crate tree, so it's better to pre-compute it in advance.

This is especially for short-term performance of https://github.com/rust-lang/rust/pull/107054 because resolver cannot use memoization of query results yet.
2023-01-21 22:35:20 +04:00
bors
005fc0f00f Auto merge of #106977 - michaelwoerister:unord_id_collections, r=oli-obk
Use UnordMap and UnordSet for id collections (DefIdMap, LocalDefIdMap, etc)

This PR changes the `rustc_data_structures::define_id_collections!` macro to use `UnordMap` and `UnordSet` instead of `FxHashMap` and `FxHashSet`. This should account for a large portion of hash-maps being used in places where they can cause trouble.

The changes required are moderate but non-zero:
- In some places the collections are extracted into sorted vecs.
- There are a few instances where for-loops have been changed to extends.

~~Let's see what the performance impact is. With a bit more refactoring, we might be able to get rid of some of the additional sorting -- but the change set is already big enough. Unless there's a performance impact, I'd like to do further changes in subsequent PRs.~~

Performance does not seem to be negatively affected ([perf-run here](https://github.com/rust-lang/rust/pull/106977#issuecomment-1396776699)).

Part of [MCP 533](https://github.com/rust-lang/compiler-team/issues/533).

r? `@ghost`
2023-01-21 14:18:17 +00:00
Michael Goulet
7e0b1f1115 Conditionally encode boolean 2023-01-19 16:09:10 +00:00
Michael Goulet
200f466d1a Encode whether foreign opaques are TAITs or not 2023-01-19 15:45:49 +00:00
Michael Woerister
72ee14ce39 Allow for more efficient sorting when exporting Unord collections. 2023-01-19 10:40:54 +01:00
Michael Woerister
c3d2573120 Use UnordMap instead of FxHashMap in define_id_collections!(). 2023-01-19 10:40:47 +01:00
Michael Goulet
a637e2a950
Rollup merge of #106917 - compiler-errors:const-closure-foreign, r=tmiasko
Encode const mir for closures if they're const

Fixes #106913
2023-01-18 18:00:29 -05:00
Matthias Krüger
68f12338af
Rollup merge of #104505 - WaffleLapkin:no-double-spaces-in-comments, r=jackh726
Remove double spaces after dots in comments

Most of the comments do not have double spaces, so I assume these are typos.
2023-01-17 20:21:25 +01:00
Maybe Waffle
6a28fb42a8 Remove double spaces after dots in comments 2023-01-17 08:09:33 +00:00
Michael Goulet
3a4fdcf86c Encode const mir for closures if they're const 2023-01-16 14:59:27 +00:00
Kyle Matsuda
6e969ea85e fix various subst_identity vs skip_binder 2023-01-14 00:30:03 -07:00
Kyle Matsuda
f29a334c90 change impl_trait_ref query to return EarlyBinder; remove bound_impl_trait_ref query; add EarlyBinder to impl_trait_ref in metadata 2023-01-14 00:29:56 -07:00
Kyle Matsuda
be130b57d4 change usages of impl_trait_ref to bound_impl_trait_ref 2023-01-14 00:23:32 -07:00
Kyle Matsuda
ef58baf8b8 change const_param_default query to return EarlyBinder; remove bound_const_param_default query; add EarlyBinder to const_param_default in metadata 2023-01-14 00:13:07 -07:00
Kyle Matsuda
bd6c63597b change usages of const_param_default query to bound_const_param_default 2023-01-14 00:13:07 -07:00
Deadbeef
6e63f7be54 attempt to make a minimal example work 2023-01-12 02:28:37 +00:00
Nilstrieb
2855794257 Use newtype for unused generic parameters 2023-01-09 19:10:00 +01:00
nils
fd7a159710 Fix uninlined_format_args for some compiler crates
Convert all the crates that have had their diagnostic migration
completed (except save_analysis because that will be deleted soon and
apfloat because of the licensing problem).
2023-01-05 19:01:12 +01:00
bors
3b1c8a94a4 Auto merge of #105609 - bjorn3:shrink_rustc_dev, r=jyn514
Only include metadata for non-dynamic libraries in rustc-dev

The actual object code should be linked from librustc_driver.so, which is still included in rustc-dev. This saves on download time and disk usage.

Fixes https://github.com/rust-lang/rust/issues/103538
2023-01-03 08:05:54 +00:00
bjorn3
7837058073 Add help for the error message when missing rustc_driver 2022-12-31 17:20:13 +00:00
Ezra Shaw
24b39ece2f
refactor: merge E0465 into E0464 2022-12-31 20:44:54 +13:00
bors
83a28ef095 Auto merge of #106129 - compiler-errors:compare_method-tweaks, r=BoxyUwU
Some `compare_method` tweaks

1. Make some of the comparison functions' names more regular
2. Reduce pub scope of some of the things in `compare_method`
~3. Remove some unnecessary opaque type handling code -- `InferCtxt` already is in a mode that doesn't define opaque types~
  * moved to a different PR
4. Bubble up `ErrorGuaranteed` for region constraint errors in `compare_method` - Improves a redundant error message in one unit test.
5. Move the `compare_method` module to have a more general name, since it's more like `compare_impl_item` :)
6. Rename `collect_trait_impl_trait_tys`
2022-12-28 13:07:30 +00:00
Michael Goulet
96d8011fa8 better names and a comment 2022-12-28 04:18:37 +00:00
Matthias Krüger
23967a9990
Rollup merge of #106137 - matthiaskrgr:clippy_style, r=jyn514
fix more clippy::style findings

match_result_ok
obfuscated_if_else
single_char_add
writeln_empty_string
collapsible_match
iter_cloned_collect
unnecessary_mut_passed

r? `@compiler-errors`
2022-12-25 22:15:00 +01:00
Matthias Krüger
6689d2df08
Rollup merge of #105955 - Nilstrieb:no-trivial-opt-wrappers-we-have-field-accesses-for-that, r=cjgillot
Remove wrapper functions for some unstable options

They are trivial and just forward to the option. Like most other options, we can just access it directly.
2022-12-25 22:15:00 +01:00
Matthias Krüger
d8874f259a fix more clippy::style findings
match_result_ok
obfuscated_if_else
single_char_add
writeln_empty_string
collapsible_match
iter_cloned_collect
unnecessary_mut_passed
2022-12-25 17:32:26 +01:00
KaDiWa
7b371d2ad9
fix some typos 2022-12-25 00:43:50 +01:00
Matthias Krüger
d23cb738d2
Rollup merge of #105975 - jeremystucki:rustc-remove-needless-lifetimes, r=eholk
rustc: Remove needless lifetimes
2022-12-24 00:31:41 +01:00
Nilstrieb
d846cf0971 A few metadata nits 2022-12-22 23:21:00 +01:00
Jeremy Stucki
3dde32ca97
rustc: Remove needless lifetimes 2022-12-20 22:10:40 +01:00
Nilstrieb
fb79e44df6 Remove wrapper functions for some unstable options
They are trivial and just forward to the option. Like most other
options, we can just access it directly.
2022-12-20 15:02:15 +01:00
Matthias Krüger
221e71e7a1
Rollup merge of #105869 - matthiaskrgr:clone_on_copy, r=compiler-errors
don't clone Copy types
2022-12-18 23:03:07 +01:00
Matthias Krüger
a108d55ce6 don't restuct references just to reborrow 2022-12-18 17:04:32 +01:00
Matthias Krüger
fec9e9ecf1 don't clone Copy types 2022-12-18 14:25:55 +01:00
bors
bbb9cfbbc5 Auto merge of #102318 - Amanieu:default_alloc_error_handler, r=oli-obk
Stabilize default_alloc_error_handler

Tracking issue: #66741

This turns `feature(default_alloc_error_handler)` on by default, which causes the compiler to automatically generate a default OOM handler which panics if `#[alloc_error_handler]` is not provided.

The FCP completed over 2 years ago but the stabilization was blocked due to an issue with unwinding. This was fixed by #88098 so stabilization can be unblocked.

Closes #66741
2022-12-16 21:08:45 +00:00
bors
918d0ac38e Auto merge of #104986 - compiler-errors:opaques, r=oli-obk
Combine `ty::Projection` and `ty::Opaque` into `ty::Alias`

Implements https://github.com/rust-lang/types-team/issues/79.

This PR consolidates `ty::Projection` and `ty::Opaque` into a single `ty::Alias`, with an `AliasKind` and `AliasTy` type (renamed from `ty::ProjectionTy`, which is the inner data of `ty::Projection`) defined as so:

```
enum AliasKind {
  Projection,
  Opaque,
}

struct AliasTy<'tcx> {
  def_id: DefId,
  substs: SubstsRef<'tcx>,
}
```

Since we don't have access to `TyCtxt` in type flags computation, and because repeatedly calling `DefKind` on the def-id is expensive, these two types are distinguished with `ty::AliasKind`, conveniently glob-imported into `ty::{Projection, Opaque}`. For example:

```diff
  match ty.kind() {
-   ty::Opaque(..) =>
+   ty::Alias(ty::Opaque, ..) => {}
    _ => {}
  }
```

This PR also consolidates match arms that treated `ty::Opaque` and `ty::Projection` identically.

r? `@ghost`
2022-12-14 01:19:24 +00:00
Michael Goulet
61adaf8187 Combine projection and opaque into alias 2022-12-13 17:48:55 +00:00
Michael Goulet
5c6afb850c ProjectionTy.item_def_id -> ProjectionTy.def_id 2022-12-13 17:34:44 +00:00
Oli Scherer
cb26b35b12 Make some diagnostics not depend on the source of what they reference being available 2022-12-13 09:48:22 +00:00
Matthias Krüger
6ed8cb6616
Rollup merge of #105472 - spastorino:make-encoder-use-queries, r=oli-obk
Make encode_info_for_trait_item use queries instead of accessing the HIR

This change avoids accessing the HIR on `encode_info_for_trait_item` and uses queries. We will need to execute this function for elements that have no HIR and by using queries we will be able to feed for definitions that have no HIR.

r? ``@oli-obk``
2022-12-11 23:36:46 +01:00
KaDiWa
9bc69925cb
compiler: remove unnecessary imports and qualified paths 2022-12-10 18:45:34 +01:00
Oli Scherer
75ff5c7dd3 Fold Definitions into the untracked data 2022-12-09 14:59:39 +00:00
Oli Scherer
1c1d3570ee Move the untracked cstore and source_span into a struct 2022-12-09 14:53:24 +00:00
Oli Scherer
2cd36f2c89 Generate crate loaders on the fly 2022-12-09 14:53:23 +00:00
Santiago Pastorino
99d229095e
Make encode_info_for_trait_item use queries instead of accessing the HIR 2022-12-08 11:58:14 -03:00
Oli Scherer
d30848b30a Use Symbol for the crate name instead of String/str 2022-12-07 20:30:02 +00:00
Oli Scherer
c38ff3b385 Remove all but one call site of prepare_outputs and fetch the value from the TyCtxt instead 2022-12-03 12:28:01 +00:00
Santiago Pastorino
537488efd6
Make inferred_outlives_crate return Clause 2022-11-29 12:01:58 -03:00
Dylan DPC
f33d4094f0
Rollup merge of #104360 - petrochenkov:stabverb, r=TaKO8Ki
Stabilize native library modifier `verbatim`

Stabilization report - https://github.com/rust-lang/rust/pull/104360#issuecomment-1312724787.

cc https://github.com/rust-lang/rust/issues/81490
Closes https://github.com/rust-lang/rust/issues/99425
2022-11-28 15:42:09 +05:30
Vadim Petrochenkov
5b0e80ecf3 Stabilize native library modifier verbatim 2022-11-27 22:36:32 +03:00
Maybe Waffle
1d42936b18 Prefer doc comments over //-comments in compiler 2022-11-27 11:19:04 +00:00
bors
f8a2e491eb Auto merge of #104730 - petrochenkov:modchild5, r=cjgillot
rustc_metadata: Switch module children decoding to an iterator

Previously https://github.com/rust-lang/rust/pull/103578, https://github.com/rust-lang/rust/pull/103524 and previous PRs simplified it as much as possible.

A couple of cleanup commits is also added.
r? `@cjgillot`
2022-11-26 05:41:34 +00:00
kadmin
f9750c1554 Add empty ConstKind::Abstract
Initial pass at expr/abstract const/s

Address comments

Switch to using a list instead of &[ty::Const], rm `AbstractConst`

Remove try_unify_abstract_consts

Update comments

Add edits

Recurse more

More edits

Prevent equating associated consts

Move failing test to ui

Changes this test from incremental to ui, and mark it as failing and a known bug.
Does not cause the compiler to ICE, so should be ok.
2022-11-25 09:28:43 +00:00
bors
872631d0f0 Auto merge of #104507 - WaffleLapkin:asderefsyou, r=wesleywiser
Use `as_deref` in compiler (but only where it makes sense)

This simplifies some code :3

(there are some changes that are not exacly `as_deref`, but more like "clever `Option`/`Result` method use")
2022-11-24 00:17:35 +00:00
Manish Goregaokar
54b6292855
Rollup merge of #104621 - YC:master, r=davidtwco
Fix --extern library finding errors

- `crate_name` is not specified/passed to `metadata_crate_location_unknown_type`
c493bae0d8/compiler/rustc_error_messages/locales/en-US/metadata.ftl (L274-L275)
- `metadata_lib_filename_form` is missing `$`
- Add additional check to ensure that library is file

Testing
1. Create file `a.rs`
```rust
extern crate t;
fn main() {}
```
1. Create empty file `x`
1. Create empty directory `y`
1. Run
```sh
$ rustc -o a a.rs --extern t=x
$ rustc -o a a.rs --extern t=y
```
Both currently panic with stable.
2022-11-22 22:54:40 -05:00
Vadim Petrochenkov
24f2ee1efd rustc_metadata: Cleanup to get_module_children
to unify proc-macro and non-proc-macro cases in particular.
2022-11-22 20:43:48 +03:00
Vadim Petrochenkov
6a233b5e2a rustc_metadata: Switch module children decoding to an iterator 2022-11-22 20:43:48 +03:00
Vadim Petrochenkov
f3b5791a47 rustc_metadata: Do not encode empty reexport lists
This is more a cleanup than optimization
2022-11-22 20:43:48 +03:00
bors
b7463e8bdb Auto merge of #103578 - petrochenkov:nofict, r=nagisa
Unreserve braced enum variants in value namespace

With this PR braced enum variants (`enum E { V { /*...*/ } }`) no longer take a slot in value namespace, so the special case mentioned in the note in https://github.com/rust-lang/rfcs/blob/master/text/1506-adt-kinds.md#braced-structs is removed.

Report - https://github.com/rust-lang/rust/pull/103578#issuecomment-1292594900.
2022-11-22 10:17:09 +00:00
Steven Tang
7169c7d105
Tests for bad --extern library path and file 2022-11-22 17:44:38 +11:00
Nicholas Nethercote
3e3a4192d8 Split MacArgs in two.
`MacArgs` is an enum with three variants: `Empty`, `Delimited`, and `Eq`. It's
used in two ways:
- For representing attribute macro arguments (e.g. in `AttrItem`), where all
  three variants are used.
- For representing function-like macros (e.g. in `MacCall` and `MacroDef`),
  where only the `Delimited` variant is used.

In other words, `MacArgs` is used in two quite different places due to them
having partial overlap. I find this makes the code hard to read. It also leads
to various unreachable code paths, and allows invalid values (such as
accidentally using `MacArgs::Empty` in a `MacCall`).

This commit splits `MacArgs` in two:
- `DelimArgs` is a new struct just for the "delimited arguments" case. It is
  now used in `MacCall` and `MacroDef`.
- `AttrArgs` is a renaming of the old `MacArgs` enum for the attribute macro
  case. Its `Delimited` variant now contains a `DelimArgs`.

Various other related things are renamed as well.

These changes make the code clearer, avoids several unreachable paths, and
disallows the invalid values.
2022-11-22 09:04:15 +11:00
Vadim Petrochenkov
7a5376d23c Unreserve braced enum variants in value namespace 2022-11-21 22:40:06 +03:00
bors
7fe6f36224 Auto merge of #103491 - cjgillot:self-rpit, r=oli-obk
Support using `Self` or projections inside an RPIT/async fn

I reuse the same idea as https://github.com/rust-lang/rust/pull/103449 to use variances to encode whether a lifetime parameter is captured by impl-trait.

The current implementation of async and RPIT replace all lifetimes from the parent generics by `'static`.  This PR changes the scheme
```rust
impl<'a> Foo<'a> {
    fn foo<'b, T>() -> impl Into<Self> + 'b { ... }
}

opaque Foo::<'_a>::foo::<'_b, T>::opaque<'b>: Into<Foo<'_a>> + 'b;
impl<'a> Foo<'a> {
    // OLD
    fn foo<'b, T>() -> Foo::<'static>::foo::<'static, T>::opaque::<'b> { ... }
                             ^^^^^^^ the `Self` becomes `Foo<'static>`

    // NEW
    fn foo<'b, T>() -> Foo::<'a>::foo::<'b, T>::opaque::<'b> { ... }
                             ^^ the `Self` stays `Foo<'a>`
}
```

There is the same issue with projections. In the example, substitute `Self` by `<T as Trait<'b>>::Assoc` in the sugared version, and `Foo<'_a>` by `<T as Trait<'_b>>::Assoc` in the desugared one.

This allows to support `Self` in impl-trait, since we do not replace lifetimes by `'static` any more.  The same trick allows to use projections like `T::Assoc` where `Self` is allowed.  The feature is gated behind a `impl_trait_projections` feature gate.

The implementation relies on 2 tweaking rules for opaques in 2 places:
- we only relate substs that correspond to captured lifetimes during TypeRelation;
- we only list captured lifetimes in choice region computation.

For simplicity, I encoded the "capturedness" of lifetimes as a variance, `Bivariant` vs `Invariant` for unused vs captured lifetimes. The `variances_of` query used to ICE for opaques.

Impl-trait that do not reference `Self` or projections will have their variances as:
- `o` (invariant) for each parent type or const;
- `*` (bivariant) for each parent lifetime --> will not participate in borrowck;
- `o` (invariant) for each own lifetime.

Impl-trait that does reference `Self` and/or projections will have some parent lifetimes marked as `o` (as the example above), and participate in type relation and borrowck.  In the example above, `variances_of(opaque) = ['_a: o, '_b: *, T: o, 'b: o]`.

r? types
cc `@compiler-errors` , as you asked about the issue with `Self` and projections.
2022-11-21 12:17:03 +00:00
Steven Tang
a1ea1c128d
Check that library is file 2022-11-20 10:48:55 +11:00
Steven Tang
1e4adaf11f
Fix CrateLocationUnknownType error 2022-11-20 10:48:37 +11:00
bors
7c75fe4c85 Auto merge of #104170 - cjgillot:hir-def-id, r=fee1-dead
Record `LocalDefId` in HIR nodes instead of a side table

This is part of an attempt to remove the `HirId -> LocalDefId` table from HIR.
This attempt is a prerequisite to creation of `LocalDefId` after HIR lowering (https://github.com/rust-lang/rust/pull/96840), by controlling how `def_id` information is accessed.

This first part adds the information to HIR nodes themselves instead of a table.
The second part is https://github.com/rust-lang/rust/pull/103902
The third part will be to make `hir::Visitor::visit_fn` take a `LocalDefId` as last parameter.
The fourth part will be to completely remove the side table.
2022-11-17 07:42:27 +00:00
Maybe Waffle
94470f4efd Use as_deref in compiler (but only where it makes sense) 2022-11-16 21:58:58 +00:00
Daniil Belov
e16c77847d Wrap bundlen static libraries into object files 2022-11-14 12:01:49 +03:00
Camille GILLOT
9d20aca983 Store a LocalDefId in hir::Variant & hir::Field. 2022-11-13 14:06:51 +00:00
Camille GILLOT
18482f7b23 Store a LocalDefId in hir::GenericParam. 2022-11-13 14:05:30 +00:00
Camille GILLOT
290f0781b4 Store LocalDefId in hir::Closure. 2022-11-13 14:04:02 +00:00
Camille GILLOT
b95650930b Compute variance for opaques too. 2022-11-12 09:56:23 +00:00
Amanieu d'Antras
f5e0b760d0 Stabilize default_alloc_error_handler
Closes #66741
2022-11-03 07:12:58 +00:00
bors
11ebe6512b Auto merge of #103217 - mejrs:track, r=eholk
Track where diagnostics were created.

This implements the `-Ztrack-diagnostics` flag, which uses `#[track_caller]` to track where diagnostics are created. It is meant as a debugging tool much like `-Ztreat-err-as-bug`.

For example, the following code...

```rust
struct A;
struct B;

fn main(){
    let _: A = B;
}
```
...now emits the following error message:

```
error[E0308]: mismatched types
 --> src\main.rs:5:16
  |
5 |     let _: A = B;
  |            -   ^ expected struct `A`, found struct `B`
  |            |
  |            expected due to this
-Ztrack-diagnostics: created at compiler\rustc_infer\src\infer\error_reporting\mod.rs:2275:31
```
2022-11-01 21:09:45 +00:00
bors
4c736a21ae Auto merge of #103496 - petrochenkov:effvisdoc2, r=lqd
rustc_metadata: Encode even less doc comments

The fact that `def_id` is in the `tcx.privacy_access_levels(())` table is not very meaningful, especially after https://github.com/rust-lang/rust/pull/102026, `is_exported` (or `is_reachable` in the worst case) is what you need.

Follow up to https://github.com/rust-lang/rust/pull/98450.
r? `@GuillaumeGomez` `@lqd`
2022-11-01 15:05:14 +00:00
Amanieu d'Antras
56074b5231 Rewrite implementation of #[alloc_error_handler]
The new implementation doesn't use weak lang items and instead changes
`#[alloc_error_handler]` to an attribute macro just like
`#[global_allocator]`.

The attribute will generate the `__rg_oom` function which is called by
the compiler-generated `__rust_alloc_error_handler`. If no `__rg_oom`
function is defined in any crate then the compiler shim will call
`__rdl_oom` in the alloc crate which will simply panic.

This also fixes link errors with `-C link-dead-code` with
`default_alloc_error_handler`: `__rg_oom` was previously defined in the
alloc crate and would attempt to reference the `oom` lang item, even if
it didn't exist. This worked as long as `__rg_oom` was excluded from
linking since it was not called.

This is a prerequisite for the stabilization of
`default_alloc_error_handler` (#102318).
2022-10-31 16:32:57 +00:00
mejrs
cbeb244b05 Add more track_caller 2022-10-31 16:14:29 +01:00
Cameron Steffen
ebfa1f0185 Encode LangItem directly 2022-10-29 16:04:10 -05:00
Nicholas Nethercote
c8c25ce5a1 Rename some OwnerId fields.
spastorino noticed some silly expressions like `item_id.def_id.def_id`.

This commit renames several `def_id: OwnerId` fields as `owner_id`, so
those expressions become `item_id.owner_id.def_id`.

`item_id.owner_id.local_def_id` would be even clearer, but the use of
`def_id` for values of type `LocalDefId` is *very* widespread, so I left
that alone.
2022-10-29 20:28:38 +11:00
Vadim Petrochenkov
d0805321d5 rustc_metadata: Encode even less doc comments 2022-10-29 12:56:33 +04:00
bors
33b55ac39f Auto merge of #102233 - petrochenkov:effvis, r=jackh726
privacy: Rename "accessibility levels" to "effective visibilities"

And a couple of other naming and comment tweaks.

Related to https://github.com/rust-lang/rust/issues/48054

For `enum Level` I initially used naming `enum EffectiveVisibilityLevel`, but it was too long and inconvenient because it's used pretty often.
So I shortened it to just `Level`, if it needs to be used from some context where this name would be ambiguous, then it can be imported with renaming like `use rustc_middle::privacy::Level as EffVisLevel` or something.
2022-10-29 03:08:59 +00:00
Matthias Krüger
4a01cab4b7
Rollup merge of #103524 - petrochenkov:modchild4, r=cjgillot
rustc_metadata: Add struct and variant constructors to module children at encoding time

instead of decoding time.

Continuation of https://github.com/rust-lang/rust/pull/95899.
The last time it caused some ICEs from generator use, but not everything seems ok.
2022-10-27 15:03:57 +02:00
Vadim Petrochenkov
34eb73c72d privacy: Rename "accessibility levels" to "effective visibilities"
And a couple of other naming tweaks

Related to https://github.com/rust-lang/rust/issues/48054
2022-10-26 16:34:53 +04:00
bors
43dd3d514b Auto merge of #103284 - compiler-errors:const-sad, r=oli-obk
Revert "Unify tcx.constness and param env constness checks"

Too much of a perf regression https://github.com/rust-lang/rust/pull/102975#issuecomment-1282702513, and an attempt in #103263 didn't fix it except for just a tiny bit.

This change isn't really needed (see https://github.com/rust-lang/rust/pull/102830#issuecomment-1272514096), so this should be an easy revert.
2022-10-26 11:29:15 +00:00
Vadim Petrochenkov
2283a5e65b rustc_metadata: Add constructors to module children at encoding time
instead of decoding time.
2022-10-25 18:11:50 +04:00
bors
9be2f35a4c Auto merge of #103431 - Dylan-DPC:rollup-oozfo89, r=Dylan-DPC
Rollup of 6 pull requests

Successful merges:

 - #101293 (Recover when unclosed char literal is parsed as a lifetime in some positions)
 - #101908 (Suggest let for assignment, and some code refactor)
 - #103192 (rustdoc: Eliminate uses of `EarlyDocLinkResolver::all_traits`)
 - #103226 (Check `needs_infer` before `needs_drop` during HIR generator analysis)
 - #103249 (resolve: Revert "Set effective visibilities for imports more precisely")
 - #103305 (Move some tests to more reasonable places)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2022-10-23 11:33:18 +00:00
Dylan DPC
e426874788
Rollup merge of #103192 - petrochenkov:noalltraits, r=jyn514
rustdoc: Eliminate uses of `EarlyDocLinkResolver::all_traits`

Another step to https://github.com/rust-lang/rust/pull/94857.
2022-10-23 15:20:17 +05:30
Nilstrieb
c65ebae221
Migrate all diagnostics 2022-10-23 10:09:44 +02:00
bors
3022afe3d1 Auto merge of #103196 - Nilstrieb:no-meta-query, r=cjgillot
Get rid of native_library projection queries

They don't seem particularly useful as I don't expect native libraries to change frequently.

Maybe they do provide significant value of keeping incremental compilation green though, I'm not sure.
2022-10-22 05:08:51 +00:00
bors
eecde5850c Auto merge of #103172 - pcwalton:deduced-param-attrs, r=oli-obk
Introduce deduced parameter attributes, and use them for deducing `readonly` on indirect immutable freeze by-value function parameters.

Introduce deduced parameter attributes, and use them for deducing `readonly` on
indirect immutable freeze by-value function parameters.

Right now, `rustc` only examines function signatures and the platform ABI when
determining the LLVM attributes to apply to parameters. This results in missed
optimizations, because there are some attributes that can be determined via
analysis of the MIR making up the function body. In particular, `readonly`
could be applied to most indirectly-passed by-value function arguments
(specifically, those that are freeze and are observed not to be mutated), but
it currently is not.

This patch introduces the machinery that allows `rustc` to determine those
attributes. It consists of a query, `deduced_param_attrs`, that, when
evaluated, analyzes the MIR of the function to determine supplementary
attributes. The results of this query for each function are written into the
crate metadata so that the deduced parameter attributes can be applied to
cross-crate functions. In this patch, we simply check the parameter for
mutations to determine whether the `readonly` attribute should be applied to
parameters that are indirect immutable freeze by-value.  More attributes could
conceivably be deduced in the future: `nocapture` and `noalias` come to mind.

Adding `readonly` to indirect function parameters where applicable enables some
potential optimizations in LLVM that are discussed in [issue 103103] and [PR
103070] around avoiding stack-to-stack memory copies that appear in functions
like `core::fmt::Write::write_fmt` and `core::panicking::assert_failed`. These
functions pass a large structure unchanged by value to a subfunction that also
doesn't mutate it. Since the structure in this case is passed as an indirect
parameter, it's a pointer from LLVM's perspective. As a result, the
intermediate copy of the structure that our codegen emits could be optimized
away by LLVM's MemCpyOptimizer if it knew that the pointer is `readonly
nocapture noalias` in both the caller and callee. We already pass `nocapture
noalias`, but we're missing `readonly`, as we can't determine whether a
by-value parameter is mutated by examining the signature in Rust. I didn't have
much success with having LLVM infer the `readonly` attribute, even with fat
LTO; it seems that deducing it at the MIR level is necessary.

No large benefits should be expected from this optimization *now*; LLVM needs
some changes (discussed in [PR 103070]) to more aggressively use the `noalias
nocapture readonly` combination in its alias analysis. I have some LLVM patches
for these optimizations and have had them looked over. With all the patches
applied locally, I enabled LLVM to remove all the `memcpy`s from the following
code:

```rust
fn main() {
    println!("Hello {}", 3);
}
```

which is a significant codegen improvement over the status quo. I expect that if this optimization kicks in in multiple places even for such a simple program, then it will apply to Rust code all over the place.

[issue 103103]: https://github.com/rust-lang/rust/issues/103103

[PR 103070]: https://github.com/rust-lang/rust/pull/103070
2022-10-22 02:28:05 +00:00
Patrick Walton
da630ac79d Introduce deduced parameter attributes, and use them for deducing readonly on
indirect immutable freeze by-value function parameters.

Right now, `rustc` only examines function signatures and the platform ABI when
determining the LLVM attributes to apply to parameters. This results in missed
optimizations, because there are some attributes that can be determined via
analysis of the MIR making up the function body. In particular, `readonly`
could be applied to most indirectly-passed by-value function arguments
(specifically, those that are freeze and are observed not to be mutated), but
it currently is not.

This patch introduces the machinery that allows `rustc` to determine those
attributes. It consists of a query, `deduced_param_attrs`, that, when
evaluated, analyzes the MIR of the function to determine supplementary
attributes. The results of this query for each function are written into the
crate metadata so that the deduced parameter attributes can be applied to
cross-crate functions. In this patch, we simply check the parameter for
mutations to determine whether the `readonly` attribute should be applied to
parameters that are indirect immutable freeze by-value.  More attributes could
conceivably be deduced in the future: `nocapture` and `noalias` come to mind.

Adding `readonly` to indirect function parameters where applicable enables some
potential optimizations in LLVM that are discussed in [issue 103103] and [PR
103070] around avoiding stack-to-stack memory copies that appear in functions
like `core::fmt::Write::write_fmt` and `core::panicking::assert_failed`. These
functions pass a large structure unchanged by value to a subfunction that also
doesn't mutate it. Since the structure in this case is passed as an indirect
parameter, it's a pointer from LLVM's perspective. As a result, the
intermediate copy of the structure that our codegen emits could be optimized
away by LLVM's MemCpyOptimizer if it knew that the pointer is `readonly
nocapture noalias` in both the caller and callee. We already pass `nocapture
noalias`, but we're missing `readonly`, as we can't determine whether a
by-value parameter is mutated by examining the signature in Rust. I didn't have
much success with having LLVM infer the `readonly` attribute, even with fat
LTO; it seems that deducing it at the MIR level is necessary.

No large benefits should be expected from this optimization *now*; LLVM needs
some changes (discussed in [PR 103070]) to more aggressively use the `noalias
nocapture readonly` combination in its alias analysis. I have some LLVM patches
for these optimizations and have had them looked over. With all the patches
applied locally, I enabled LLVM to remove all the `memcpy`s from the following
code:

```rust
fn main() {
    println!("Hello {}", 3);
}
```

which is a significant codegen improvement over the status quo. I expect that
if this optimization kicks in in multiple places even for such a simple
program, then it will apply to Rust code all over the place.

[issue 103103]: https://github.com/rust-lang/rust/issues/103103

[PR 103070]: https://github.com/rust-lang/rust/pull/103070
2022-10-21 02:33:15 -07:00
Guillaume Gomez
ae5108a1ed Add code comments and documentation 2022-10-20 22:44:10 +00:00
Guillaume Gomez
72d6fde130 Remove doc comments only for private items or some specific doc comments 2022-10-20 22:44:10 +00:00
Michael Goulet
ab36a2fe16 Revert "Unify tcx.constness and param env constness checks"
This reverts commit bef8681a18.
This reverts commit c646c4d403.
2022-10-20 03:44:12 +00:00
nils
ccc54613c3
Get rid of native_library projection queries
They don't seem particularly useful as I don't expect
native libraries to change frequently.
2022-10-19 16:21:21 +02:00
Vadim Petrochenkov
175474549c rustdoc: Eliminate uses of EarlyDocLinkResolver::all_traits 2022-10-19 12:55:38 +04:00
Wesley Wiser
097b6d3baf Add suggestion to the "missing native library" error
If we fail to locate a native library that we are linking with, it could
be the case the user entered a complete file name like `foo.lib` or
`libfoo.a` when we expect them to simply provide `foo`.

In this situation, we now detect that case and suggest the user only
provide the library name itself.
2022-10-13 07:35:36 -04:00
Michael Goulet
bef8681a18 TyAlias needs encoded constness too, for layout computation in rustdoc 2022-10-12 04:17:21 +00:00
Michael Goulet
c646c4d403 Unify tcx.constness and param env constness checks 2022-10-12 04:04:09 +00:00
Cameron Steffen
ff940db666 Rewrite representability 2022-10-07 09:33:46 -05:00
bors
0152393048 Auto merge of #99324 - reez12g:issue-99144, r=jyn514
Enable doctests in compiler/ crates

Helps with https://github.com/rust-lang/rust/issues/99144
2022-10-06 03:01:57 +00:00
bors
b3aa4997d4 Auto merge of #102164 - compiler-errors:rpitit-foreign, r=TaKO8Ki
Serialize return-position `impl Trait` in trait hidden values in foreign libraries

Fixes #101630
2022-09-30 04:24:14 +00:00
reez12g
9a4c5abe45 Remove from compiler/ crates 2022-09-29 16:49:04 +09:00
Pietro Albini
3975d55d98
remove cfg(bootstrap) 2022-09-26 10:14:45 +02:00
Takayuki Maeda
8fe936099a separate definitions and HIR owners
fix a ui test

use `into`

fix clippy ui test

fix a run-make-fulldeps test

implement `IntoQueryParam<DefId>` for `OwnerId`

use `OwnerId` for more queries

change the type of `ParentOwnerIterator::Item` to `(OwnerId, OwnerNode)`
2022-09-24 23:21:19 +09:00
Michael Goulet
2fa31d3e78 Serialize RPITIT values in libs 2022-09-23 00:56:55 +00:00
bors
9062b780b3 Auto merge of #101558 - JhonnyBillM:session-diagnostic-to-diagnostic-handler-refactor, r=davidtwco
Move and rename `SessionDiagnostic` & `SessionSubdiagnostic` traits and macros

After PR #101434, we want to:
- [x] Move `SessionDiagnostic` to `rustc_errors`.
- [x] Add `emit_` methods that accept `impl SessionDiagnostic` to `Handler`.
- [x] _(optional)_ Rename trait `SessionDiagnostic` to `DiagnosticHandler`.
- [x] _(optional)_ Rename macro `SessionDiagnostic` to `DiagnosticHandler`.
- [x] Update Rustc Dev Guide and Docs to reflect these changes. https://github.com/rust-lang/rustc-dev-guide/pull/1460

Now I am having build issues getting the compiler to build when trying to rename the macro.

<details>
  <summary>See diagnostics errors and context when building.</summary>

```
error: diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
  --> compiler/rustc_attr/src/session_diagnostics.rs:13:10
   |
13 |   #[derive(DiagnosticHandler)]
   |            ^^^^^^^^^^^^^^^^^ in this derive macro expansion
   |
  ::: /Users/jhonny/.cargo/registry/src/github.com-1ecc6299db9ec823/synstructure-0.12.6/src/macros.rs:94:9
   |
94 | /         pub fn $derives(
95 | |             i: $crate::macros::TokenStream
96 | |         ) -> $crate::macros::TokenStream {
   | |________________________________________- in this expansion of `#[derive(DiagnosticHandler)]`
   |
note: the lint level is defined here
  --> compiler/rustc_attr/src/lib.rs:10:9
   |
10 | #![deny(rustc::diagnostic_outside_of_impl)]
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

```

And also this one:

```
error: diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
   --> compiler/rustc_attr/src/session_diagnostics.rs:213:32
    |
213 |         let mut diag = handler.struct_span_err_with_code(
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^
```

> **Note**
> Can't find where this message is coming from, because you can see in [this experimental branch](https://github.com/JhonnyBillM/rust/tree/experimental/trying-to-rename-session-diagnostic-macro)  that I updated all errors and diags to say:
> error: diagnostics should only be created in **`DiagnosticHandler`**/`AddSubdiagnostic` impls
> and not:
> error: diagnostics should only be created in **`SessionDiagnostic`**/`AddSubdiagnostic` impls

</details>

I tried building the compiler in different ways (playing with the stages etc), but nothing worked.

## Question

**Do we need to build or do something different when renaming a macro and identifiers?**

For context, see experimental commit f2193a98b4 where the macro and symbols are renamed, but it doesn't compile.
2022-09-21 19:58:39 +00:00
Jhonny Bill Mena
e52e2344dc FIX - adopt new Diagnostic naming in newly migrated modules
FIX - ambiguous Diagnostic link in docs

UPDATE - rename diagnostic_items to IntoDiagnostic and AddToDiagnostic

[Gardening] FIX - formatting via `x fmt`

FIX - rebase conflicts. NOTE: Confirm wheather or not we want to handle TargetDataLayoutErrorsWrapper this way

DELETE - unneeded allow attributes in Handler method

FIX - broken test

FIX - Rebase conflict

UPDATE - rename residual _SessionDiagnostic and fix LintDiag link
2022-09-21 11:43:22 -04:00
Jhonny Bill Mena
a3396b2070 UPDATE - rename DiagnosticHandler macro to Diagnostic 2022-09-21 11:39:53 -04:00
Jhonny Bill Mena
19b348fed4 UPDATE - rename DiagnosticHandler trait to IntoDiagnostic 2022-09-21 11:39:52 -04:00
Jhonny Bill Mena
5b8152807c UPDATE - move SessionDiagnostic from rustc_session to rustc_errors 2022-09-21 11:39:52 -04:00
Nicholas Nethercote
a7b35b5618 Overhaul -Zmeta-stats output.
It's now much more like the `-Zhir-stats` output.
- Each line is preceded with `meta-stats`, which makes the provenance
  clearer and allows filtering of the output.
- Sections are now sorted in reverse order of size.
- Column headings avoid the need to repeat the word "bytes" on every line.
- Long numbers now have `_` separators for easier reading.
- Consistent use of '-' within section labels, rather than a mix of '-',
  '_', and ' '.

The code itself is shorter and easier to read thanks to:
- the `stat` macro, which encapsulates each section's encoding, avoids
  some boilerplate, and removes the need for some low-value comments;
- the `stats` vector, which replaces dozens of local variables.
2022-09-21 11:22:31 +10:00
Nicholas Nethercote
b7dc9341b5 Wrap some long comment lines. 2022-09-21 08:06:06 +10:00
bors
8fd6d03e22 Auto merge of #101806 - BelovDV:issue-fix-fn-find_library, r=petrochenkov
fix verbatim with upstream dependencies

https://github.com/rust-lang/rust/issues/99425#issuecomment-1207224161

r? `@petrochenkov`
2022-09-20 07:10:18 +00:00
bors
a38a082afb fix verbatim with upstream dependencies
https://github.com/rust-lang/rust/issues/99425#issuecomment-1207224161

r? `@petrochenkov`
2022-09-20 07:10:17 +00:00
Dylan DPC
3ad81e0dd8
Rollup merge of #93628 - est31:stabilize_let_else, r=joshtriplett
Stabilize `let else`

🎉  **Stabilizes the `let else` feature, added by [RFC 3137](https://github.com/rust-lang/rfcs/pull/3137).** 🎉

Reference PR: https://github.com/rust-lang/reference/pull/1156

closes #87335 (`let else` tracking issue)

FCP: https://github.com/rust-lang/rust/pull/93628#issuecomment-1029383585

----------

## Stabilization report

### Summary

The feature allows refutable patterns in `let` statements if the expression is
followed by a diverging `else`:

```Rust
fn get_count_item(s: &str) -> (u64, &str) {
    let mut it = s.split(' ');
    let (Some(count_str), Some(item)) = (it.next(), it.next()) else {
        panic!("Can't segment count item pair: '{s}'");
    };
    let Ok(count) = u64::from_str(count_str) else {
        panic!("Can't parse integer: '{count_str}'");
    };
    (count, item)
}
assert_eq!(get_count_item("3 chairs"), (3, "chairs"));
```

### Differences from the RFC / Desugaring

Outside of desugaring I'm not aware of any differences between the implementation and the RFC. The chosen desugaring has been changed from the RFC's [original](https://rust-lang.github.io/rfcs/3137-let-else.html#reference-level-explanations). You can read a detailed discussion of the implementation history of it in `@cormacrelf` 's [summary](https://github.com/rust-lang/rust/pull/93628#issuecomment-1041143670) in this thread, as well as the [followup](https://github.com/rust-lang/rust/pull/93628#issuecomment-1046598419). Since that followup, further changes have happened to the desugaring, in #98574, #99518, #99954. The later changes were mostly about the drop order: On match, temporaries drop in the same order as they would for a `let` declaration. On mismatch, temporaries drop before the `else` block.

### Test cases

In chronological order as they were merged.

Added by df9a2e0687 (#87688):

* [`ui/pattern/usefulness/top-level-alternation.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/pattern/usefulness/top-level-alternation.rs) to ensure the unreachable pattern lint visits patterns inside `let else`.

Added by 5b95df4bdc (#87688):

* [`ui/let-else/let-else-bool-binop-init.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-bool-binop-init.rs) to ensure that no lazy boolean expressions (using `&&` or `||`) are allowed in the expression, as the RFC mandates.
* [`ui/let-else/let-else-brace-before-else.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-brace-before-else.rs) to ensure that no `}` directly preceding the `else` is allowed in the expression, as the RFC mandates.
* [`ui/let-else/let-else-check.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-check.rs) to ensure that `#[allow(...)]` attributes added to the entire `let` statement apply for the `else` block.
* [`ui/let-else/let-else-irrefutable.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-irrefutable.rs) to ensure that the `irrefutable_let_patterns` lint fires.
* [`ui/let-else/let-else-missing-semicolon.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-missing-semicolon.rs) to ensure the presence of semicolons at the end of the `let` statement.
* [`ui/let-else/let-else-non-diverging.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-non-diverging.rs) to ensure the `else` block diverges.
* [`ui/let-else/let-else-run-pass.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-run-pass.rs) to ensure the feature works in some simple test case settings.
* [`ui/let-else/let-else-scope.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-scope.rs) to ensure the bindings created by the outer `let` expression are not available in the `else` block of it.

Added by bf7c32a447 (#89965):

* [`ui/let-else/issue-89960.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/issue-89960.rs) as a regression test for the ICE-on-error bug #89960 . Later in 102b9125e1 this got removed in favour of more comprehensive tests.

Added by 856541963c (#89974):

* [`ui/let-else/let-else-if.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-if.rs) to test for the improved error message that points out that `let else if` is not possible.

Added by 9b45713b6c:

* [`ui/let-else/let-else-allow-unused.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-allow-unused.rs) as a regression test for #89807, to ensure that `#[allow(...)]` attributes added to the entire `let` statement apply for bindings created by the `let else` pattern.

Added by 61bcd8d307 (#89841):

* [`ui/let-else/let-else-non-copy.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-non-copy.rs) to ensure that a copy is performed out of non-copy wrapper types. This mirrors `if let` behaviour. The test case bases on rustc internal changes originally meant for #89933 but then removed from the PR due to the error prior to the improvements of #89841.
* [`ui/let-else/let-else-source-expr-nomove-pass.rs `](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-source-expr-nomove-pass.rs) to ensure that while there is a move of the binding in the successful case, the `else` case can still access the non-matching value. This mirrors `if let` behaviour.

Added by 102b9125e1 (#89841):

* [`ui/let-else/let-else-ref-bindings.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-ref-bindings.rs) and [`ui/let-else/let-else-ref-bindings-pass.rs `](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-ref-bindings-pass.rs) to check `ref` and `ref mut` keywords in the pattern work correctly and error when needed.

Added by 2715c5f984 (#89841):

* Match ergonomic tests adapted from the `rfc2005` test suite.

Added by fec8a507a2 (#89841):

* [`ui/let-else/let-else-deref-coercion-annotated.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-deref-coercion-annotated.rs) and [`ui/let-else/let-else-deref-coercion.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-deref-coercion.rs) to check deref coercions.

#### Added since this stabilization report was originally written (2022-02-09)

Added by 76ea566677 (#94211):

* [`ui/let-else/let-else-destructuring.rs`](https://github.com/rust-lang/rust/blob/1.63.0/src/test/ui/let-else/let-else-destructuring.rs) to give a nice error message if an user tries to do an assignment with a (possibly refutable) pattern and an `else` block, like asked for in #93995.

Added by e7730dcb7e (#94208):

* [`ui/let-else/let-else-allow-in-expr.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-allow-in-expr.rs) to test whether `#[allow(unused_variables)]` works in the expr, as well as its non presence, as well as putting it on the entire `let else` *affects* the expr, too. This was adding a missing test as pointed out by the stabilization report.
* Expansion of `ui/let-else/let-else-allow-unused.rs` and `ui/let-else/let-else-check.rs` to ensure that non-presence of `#[allow(unused)]` does issue the unused lint. This was adding a missing test case as pointed out by the stabilization report.

Added by 5bd71063b3 (#94208):

* [`ui/let-else/let-else-slicing-error.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-slicing-error.rs), a regression test for #92069, which got fixed without addition of a regression test. This resolves a missing test as pointed out by the stabilization report.

Added by 5374688e1d (#98574):

* [`src/test/ui/async-await/async-await-let-else.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/async-await/async-await-let-else.rs) to test the interaction of async/await with `let else`

Added by 6c529ded86 (#98574):

* [`src/test/ui/let-else/let-else-temporary-lifetime.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) as a (partial) regression test for #98672

Added by 9b56640106 (#99518):

* [`src/test/ui/let-else/let-else-temp-borrowck.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) as a regression test for #93951
* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a partial regression test for #98672 (especially regarding `else` drop order)

Added by baf9a7cb57 (#99518):

* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a partial regression test for #93951, similar to `let-else-temp-borrowck.rs`

Added by 60be2de8b7 (#99518):

* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a program that can now be compiled thanks to borrow checker implications of #99518

Added by 47a7a91c96 (#100132):

* [`src/test/ui/let-else/issue-100103.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-100103.rs), as a regression test for #100103, to ensure that there is no ICE when doing `Err(...)?` inside else blocks.

Added by e3c5bd617d (#100443):

* [`src/test/ui/let-else/let-else-then-diverge.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-then-diverge.rs), to verify that there is no unreachable code error with the current desugaring.

Added by 981852677c (#100443):

* [`src/test/ui/let-else/issue-94176.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-94176.rs), to make sure that a correct span is emitted for a missing trailing expression error. Regression test for #94176.

Added by e182d12a84 (#100434):

* [src/test/ui/unpretty/pretty-let-else.rs](https://github.com/rust-lang/rust/blob/master/src/test/ui/unpretty/pretty-let-else.rs), as a regression test to ensure pretty printing works for `let else` (this bug surfaced in many different ways)

Added by e26285603c (#99954):

* [`src/test/ui/let-else/let-else-temporary-lifetime.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) extended to contain & borrows as well, as this was identified as an earlier issue with the desugaring: https://github.com/rust-lang/rust/issues/98672#issuecomment-1200196921

Added by 2d8460ef43 (#99291):

* [`src/test/ui/let-else/let-else-drop-order.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-drop-order.rs) a matrix based test for various drop order behaviour of `let else`. Especially, it verifies equality of `let` and `let else` drop orders, [resolving](https://github.com/rust-lang/rust/pull/93628#issuecomment-1238498468) a [stabilization blocker](https://github.com/rust-lang/rust/pull/93628#issuecomment-1055738523).

Added by 1b87ce0d40 (#101410):

* Edit to `src/test/ui/let-else/let-else-temporary-lifetime.rs` to add the `-Zvalidate-mir` flag, as a regression test for #99228

Added by af591ebe4d (#101410):

* [`src/test/ui/let-else/issue-99975.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-99975.rs) as a regression test for the ICE #99975.

Added by this PR:

* `ui/let-else/let-else.rs`, a simple run-pass check, similar to `ui/let-else/let-else-run-pass.rs`.

### Things not currently tested

* ~~The `#[allow(...)]` tests check whether allow works, but they don't check whether the non-presence of allow causes a lint to fire.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~There is no `#[allow(...)]` test for the expression, as there are tests for the pattern and the else block.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~`let-else-brace-before-else.rs` forbids the `let ... = {} else {}` pattern and there is a rustfix to obtain `let ... = ({}) else {}`. I'm not sure whether the `.fixed` files are checked by the tooling that they compile. But if there is no such check, it would be neat to make sure that `let ... = ({}) else {}` compiles.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~#92069 got closed as fixed, but no regression test was added. Not sure it's worth to add one.~~ → *test added by 5bd71063b3810d977aa376d1e6dd7cec359330cc*
* ~~consistency between `let else` and `if let` regarding lifetimes and drop order: https://github.com/rust-lang/rust/pull/93628#issuecomment-1055738523~~ → *test added by 2d8460ef43d902f34ba2133fe38f66ee8d2fdafc*

Edit: they are all tested now.

### Possible future work / Refutable destructuring assignments

[RFC 2909](https://rust-lang.github.io/rfcs/2909-destructuring-assignment.html) specifies destructuring assignment, allowing statements like `FooBar { a, b, c } = foo();`.
As it was stabilized, destructuring assignment only allows *irrefutable* patterns, which before the advent of `let else` were the only patterns that `let` supported.
So the combination of `let else` and destructuring assignments gives reason to think about extensions of the destructuring assignments feature that allow refutable patterns, discussed in #93995.

A naive mapping of `let else` to destructuring assignments in the form of `Some(v) = foo() else { ... };` might not be the ideal way. `let else` needs a diverging `else` clause as it introduces new bindings, while assignments have a default behaviour to fall back to if the pattern does not match, in the form of not performing the assignment. Thus, there is no good case to require divergence, or even an `else` clause at all, beyond the need for having *some* introducer syntax so that it is clear to readers that the assignment is not a given (enums and structs look similar). There are better candidates for introducer syntax however than an empty `else {}` clause, like `maybe` which could be added as a keyword on an edition boundary:

```Rust
let mut v = 0;
maybe Some(v) = foo(&v);
maybe Some(v) = foo(&v) else { bar() };
```

Further design discussion is left to an RFC, or the linked issue.
2022-09-17 15:31:06 +05:30
Dylan DPC
61126d3611
Rollup merge of #101738 - dpaoliello:linkname, r=petrochenkov
Fix `#[link kind="raw-dylib"]` to respect `#[link_name]`

Issue Details:
When using `#[link kind="raw-dylib"]` (#58713), the Rust compiler ignored any `#[link_name]` attributes when generating the import library and so the resulting binary would fail to link due to missing symbols.

Fix Details:
Use the name from `#[link_name]` if present when generating the `raw-dylib` import library, otherwise default back to the actual symbol name.
2022-09-16 11:17:00 +05:30