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17212 Commits

Author SHA1 Message Date
bors
432abd86f2 Auto merge of #102061 - notriddle:rollup-kwu9vp8, r=notriddle 
Rollup of 12 pull requests

Successful merges:

 - #100250 (Manually cleanup token stream when macro expansion aborts.)
 - #101014 (Fix -Zmeta-stats ICE by giving `FileEncoder` file read permissions)
 - #101958 (Improve error for when query is unsupported by crate)
 - #101976 (MirPhase: clarify that linting is not a semantic change)
 - #102001 (Use LLVM C-API to build atomic cmpxchg and fence)
 - #102008 (Add GUI test for notable traits element position)
 - #102013 (Simplify rpitit handling on lower_fn_decl)
 - #102021 (some post-valtree cleanup)
 - #102027 (rustdoc: remove `docblock` class from `item-decl`)
 - #102034 (rustdoc: remove no-op CSS `h1-6 { border-bottom-color }`)
 - #102038 (Make the `normalize-overflow` rustdoc test actually do something)
 - #102053 (⬆️ rust-analyzer)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
 2022-09-20 19:10:11 +00:00
Michael Howell
b149c48186
Rollup merge of #102021 - lcnr:tyConst-fun, r=b-naber,BoxyUwU 
some post-valtree cleanup

r? project-const-generics cc ```@b-naber```
 2022-09-20 10:13:01 -07:00
Michael Howell
08b369a501
Rollup merge of #102013 - spastorino:rpitit-lower-fn-decl, r=compiler-errors 
Simplify rpitit handling on lower_fn_decl

r? `````@compiler-errors`````
 2022-09-20 10:13:00 -07:00
Michael Howell
2c57a5b166
Rollup merge of #102001 - cuviper:build-atomic-capi, r=nikic 
Use LLVM C-API to build atomic cmpxchg and fence

We don't need C++ wrappers because the LLVM C API can build these.
 2022-09-20 10:12:59 -07:00
Michael Howell
0d2e57cb04
Rollup merge of #101976 - RalfJung:mir-semantic-phases, r=oli-obk 
MirPhase: clarify that linting is not a semantic change

r? ```@JakobDegen```
 2022-09-20 10:12:58 -07:00
Michael Howell
2c893737a6
Rollup merge of #101958 - hanar3:101666/enhance-error-message, r=oli-obk 
Improve error for when query is unsupported by crate

This is an improvement to the error message mentioned on #101666.  It seems like a good idea to also add [this link to the rustc-dev-guide](https://rustc-dev-guide.rust-lang.org/query.html), if explaining the query system in detail is a concern here, but I'm unsure if there is any restrictions on adding links to error messages.
 2022-09-20 10:12:58 -07:00
Michael Howell
3f377d3f96
Rollup merge of #101014 - isikkema:fix-zmeta-stats-file-encoder-no-read-perms, r=isikkema 
Fix -Zmeta-stats ICE by giving `FileEncoder` file read permissions

Fixes #101001

As far as I can tell, #101001 is caused because the file is being created with write-only permissions here: https://github.com/rust-lang/rust/blob/master/compiler/rustc_serialize/src/opaque.rs#L196

but it is trying to be read here: https://github.com/rust-lang/rust/blob/master/compiler/rustc_metadata/src/rmeta/encoder.rs#L780

This PR attempts to fix this by creating/opening the file with the same permissions as `File::create()` with the addition of read.
 2022-09-20 10:12:57 -07:00
Michael Howell
14b27cfd11
Rollup merge of #100250 - cjgillot:recover-token-stream, r=Aaron1011 
Manually cleanup token stream when macro expansion aborts.

In case of syntax error in macro expansion, the expansion code can decide to stop processing anything. In that case, the token stream is malformed. This makes downstream users, like derive macros, ICE.

In this case, this PR manually cleans up the token stream by closing all currently open delimiters.

Fixes https://github.com/rust-lang/rust/issues/96818.
Fixes https://github.com/rust-lang/rust/issues/80447.
Fixes https://github.com/rust-lang/rust/issues/81920.
Fixes https://github.com/rust-lang/rust/issues/91023.
 2022-09-20 10:12:56 -07:00
bors
cd8cc91045 Auto merge of #101989 - fee1-dead-contrib:const_trait_impl-assoc-caller-bounds, r=oli-obk 
make projection bounds with const bounds satisfy const

Fixes #101982.
 2022-09-20 16:24:36 +00:00
Sikkema, Isaac
a2cb8a4949 add comment explaining read permissions 2022-09-20 10:06:50 -04:00
bors
4136b59b7d Auto merge of #99806 - oli-obk:unconstrained_opaque_type, r=estebank 
Allow patterns to constrain the hidden type of opaque types

fixes #96572

reverts a revert as original PR was a perf regression that was fixed by reverting it: https://github.com/rust-lang/rust/pull/99368#issuecomment-1186587864)

TODO:

* check if https://github.com/rust-lang/rust/issues/99685 is avoided
 2022-09-20 12:09:52 +00:00
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
bors
acb8934fd5 Auto merge of #102022 - matthiaskrgr:rollup-emwfjd1, r=matthiaskrgr 
Rollup of 11 pull requests

Successful merges:

 - #101389 (Tone down explanation on RefCell::get_mut)
 - #101798 (Make `from_waker`, `waker` and `from_raw` unstably `const`)
 - #101881 (Remove an unused struct field `late_bound`)
 - #101904 (Add help for invalid inline argument)
 - #101966 (Add unit test for identifier Unicode emoji diagnostics)
 - #101979 (Update release notes for 1.64)
 - #101985 (interpret: expose generate_stacktrace without full InterpCx)
 - #102004 (Try to clarify what's new in 1.64.0 ffi types)
 - #102005 (rustdoc: remove unused CSS `td.summary-column`)
 - #102017 (Add all submodules to the list of directories tidy skips)
 - #102019 (Remove backed off PRs from relnotes)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
 2022-09-20 02:20:15 +00:00
bors
2019147c56 Auto merge of #101894 - dingxiangfei2009:let-else-avoid-duplicate-storage-live, r=oli-obk 
Avoid duplicating StorageLive in let-else

cc `@est31`

Fix #101867
Fix #101932

#101410 introduced directives to activate storages of bindings in let-else earlier. However, since it is using the machinery of `match` and friends for pattern matching and binding, those storages are activated for the second time. This PR adjusts this behavior and avoid the duplicated activation for let-else statements.
 2022-09-19 17:27:30 +00:00
Matthias Krüger
8c0f8a285f
Rollup merge of #101985 - RalfJung:generate_stacktrace, r=oli-obk 
interpret: expose generate_stacktrace without full InterpCx

In Miri we sometimes want to emit diagnostics without having a full `&InterpCx` available. To avoid duplicating code, this adds a way to get a stacktrace from an arbitrary slice of interpreter frames, that Miri can use with access to just a thread manager.
 2022-09-19 17:55:21 +02:00
Matthias Krüger
9f073b0de0
Rollup merge of #101904 - Rageking8:fix-101712, r=oli-obk 
Add help for invalid inline argument

Fixes #101712

Removed 1 part of the test as its identical with another one. Do let me know if this is undesirable, so I can revert those changes.
 2022-09-19 17:55:20 +02:00
Matthias Krüger
7697a244cc
Rollup merge of #101881 - TaKO8Ki:remove-unused-struct-field, r=sanxiyn 
Remove an unused struct field `late_bound`
 2022-09-19 17:55:19 +02:00
Oli Scherer
1905f8c441 Document projection condition 2022-09-19 15:33:36 +00:00
lcnr
c54c5a3c77 DestructuredConst split mir and ty 2022-09-19 17:00:38 +02:00
lcnr
526856768d ctfe, const_to_op only for mir constants 2022-09-19 16:17:33 +02:00
lcnr
638b612154 remove ty::Const::from_inline_const 2022-09-19 16:10:18 +02:00
lcnr
7207b4dc66 remove FnCtxt::to_const 2022-09-19 16:08:40 +02:00
Santiago Pastorino
550bd0945f
Simplify rpitit handling on lower_fn_decl 2022-09-19 09:30:39 -03:00
bors
11bb80a92b Auto merge of #101901 - lcnr:early-binder-type-foldable, r=compiler-errors 
`EarlyBinder` prevent misuse

folding a type before substituting is pretty much always wrong and could happen by accident, e.g. see https://github.com/rust-lang/rust/pull/99798#discussion_r968666538

this PR removes the `TypeFoldable` and `TypeVisitable` impl from `EarlyBinder`.

r? types cc `@jackh726`
 2022-09-19 10:35:09 +00:00
lcnr
0c3e01d8f6 extend polymorphization hack comment. 2022-09-19 11:44:29 +02:00
lcnr
647052fc04 remove the Subst trait, always use EarlyBinder 2022-09-19 11:37:27 +02:00
lcnr
d398b54de6 do not implement type traversal for EarlyBinder 2022-09-19 11:28:32 +02:00
bors
503e19d01e Auto merge of #101629 - compiler-errors:issue-101623, r=sanxiyn 
Be careful about `expr_ty_adjusted` when noting block tail type

Fixes #101623
 2022-09-19 07:41:54 +00:00
bors
efa717bc2d Auto merge of #101924 - jackh726:revert-static-hrtb-error, r=compiler-errors 
Re-add HRTB implied static bug note

r? `@compiler-errors` since you reviewed it previously

I deleted a `normalize` call and forgot about it. Whoops.
 2022-09-19 04:56:14 +00:00
Josh Stone
fac12e25dd Use LLVM C-API to build atomic cmpxchg and fence 2022-09-18 16:01:57 -07:00
Ralf Jung
9fa3171015 interpret: expose generate_stacktrace without full InterpCx 2022-09-18 20:51:04 +02:00
Deadbeef
ee96ae0a32 make projection bounds with const bounds satisfy const 2022-09-18 18:05:30 +00:00
Ralf Jung
eed6fdb0eb clarify that linting is not a semantic change 2022-09-18 14:14:42 +02:00
Ding Xiang Fei
48c1c1d190
avoid duplicating StorageLive in let-else 2022-09-18 12:10:53 +08:00
bors
65c16dc3a8 Auto merge of #101960 - matthiaskrgr:rollup-1l5v7ip, r=matthiaskrgr 
Rollup of 5 pull requests

Successful merges:

 - #101151 (Document x86_64-fortanix-unknown-sgx platform)
 - #101912 (Update `unicode-rs` crates to Unicode 15)
 - #101923 (Don't add rustdoc's CSS to other doc pages)
 - #101953 (Fix tooltip display for error codes)
 - #101954 (rustdoc: remove redundant `.location a { font-weight: 500 }`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
 2022-09-18 03:40:01 +00:00
Matthias Krüger
46ebe7cf41
Rollup merge of #101912 - crlf0710:compiler_update_unicode_15, r=Manishearth 
Update `unicode-rs` crates to Unicode 15

r? `@Manishearth`
 2022-09-18 02:55:29 +02:00
bors
bc7b17cfe3 Auto merge of #101862 - cjgillot:lint-regression, r=oli-obk 
Do not fetch HIR node when iterating to find lint.

Addresses the regression in https://github.com/rust-lang/rust/pull/101620
 2022-09-18 00:46:14 +00:00
hanar3
0405a5d4e9 improve error message for when a query isn't supported 2022-09-17 20:25:37 -03:00
bors
5253b0a0a1 Auto merge of #101949 - matthiaskrgr:rollup-xu5cqnd, r=matthiaskrgr 
Rollup of 7 pull requests

Successful merges:

 - #101093 (Initial version of 1.64 release notes)
 - #101713 (change AccessLevels representation)
 - #101821 (Bump Unicode to version 15.0.0, regenerate tables)
 - #101826 (Enforce "joined()" and "joined_with_noop()" test)
 - #101835 (Allow using vendoring when running bootstrap from outside the source root)
 - #101942 (Revert "Copy stage0 binaries into stage0-sysroot")
 - #101943 (rustdoc: remove unused CSS `.non-exhaustive { margin-bottom }`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
 2022-09-17 22:04:28 +00:00
Matthias Krüger
a6b34cd928
Rollup merge of #101713 - Bryanskiy:AccessLevels, r=petrochenkov 
change AccessLevels representation

Part of RFC (https://github.com/rust-lang/rust/issues/48054). This patch implements effective visibility table with basic methods and change AccessLevels table representation according to it.

r? ``@petrochenkov``
 2022-09-17 23:30:49 +02:00
Matthias Krüger
4757d2d57e
Rollup merge of #101801 - SparrowLii:query_depth_note, r=estebank 
add note for `layout_of` when query depth overflows

Fixes #101747
Added `try_find_layout_root` function to add a note for `layout_of` when query depth overflows. This would make the error in #101747 look like this:
```
error: queries overflow the depth limit!
   |
note: Query depth increased by 66 when computing layout of `core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<core::option::Option<alloc::boxed::Box<alloc::string::String>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>`!
  --> D:\rust-backup\parallel_rust\query_depth.rs:40:1
   |
40 | fn main() {
   | ^^^^^^^^^

error: aborting due to previous error
```

cc ``@semicoleon``
 2022-09-17 19:27:06 +02:00
Jack Huey
e7ca6e1b47 Use Predicate ConstraintCategory when normalizing 2022-09-17 11:46:05 -04:00
Jack Huey
1eb71f0893 Add back in normalize call 2022-09-17 11:46:04 -04:00
bors
48de123d7a Auto merge of #101857 - lcnr:make-dyn-again, r=jackh726 
change `FnMutDelegate` to trait objects

cc #100016 as mentioned in the last t-compiler meeting

r? `@jackh726`
 2022-09-17 13:37:48 +00:00
Dylan DPC
7c55c992ab
Rollup merge of #101807 - jackh726:no-gat-defaults, r=lcnr 
Disallow defaults on type GATs

Fixes #99205
 2022-09-17 15:31:08 +05:30
Dylan DPC
4c64c14420
Rollup merge of #101790 - TaKO8Ki:do-not-suggest-placeholder-to-const-and-static-without-type, r=compiler-errors 
Do not suggest a placeholder to const and static without a type

Fixes #101755
 2022-09-17 15:31:08 +05:30
Dylan DPC
cbd561d41f
Rollup merge of #98441 - calebzulawski:simd_as, r=oli-obk 
Implement simd_as for pointers

Expands `simd_as` (and `simd_cast`) to handle pointer-to-pointer, pointer-to-integer, and integer-to-pointer conversions.

cc ``@programmerjake`` ``@thomcc``
 2022-09-17 15:31:07 +05:30
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
bors
4a12d10bcc Auto merge of #101928 - notriddle:rollup-pexhhxe, r=notriddle 
Rollup of 8 pull requests

Successful merges:

 - #101340 (Adding Fuchsia zxdb debugging walkthrough to docs)
 - #101741 (Adding needs-unwind arg to applicable compiler ui tests)
 - #101782 (Update `symbol_mangling` diagnostics migration)
 - #101878 (More simple formatting)
 - #101898 (Remove some unused CSS rules)
 - #101911 (rustdoc: remove no-op CSS on `.source .content`)
 - #101914 (rustdoc-json-types: Document that ResolvedPath can also be a union)
 - #101921 (Pass --cfg=bootstrap for rustdoc for proc_macro crates)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
 2022-09-17 05:45:28 +00:00