Also remove a no-longer accurate comments

…the others

Co-Authored-By: RalfJung <post@ralfj.de>

Simplify input validation for `#[unwind]`, add tests

…ategy

Make `Unique::as_ptr` const without feature attribute as it's unstable
Make `NonNull::dangling` and `NonNull::cast` const with `feature = "const_ptr_nonnull"`

The old logic would incorrectly look for "python2.exe" when searching
for "python2.7.exe".

Before this commit, if you're running x.py directly on a system where
`python` is symlinked to Python 3, then the `python` config option will
default to a Python 3 interpreter. This causes debuginfo tests to fail
with an opaque error message, since they have a hard requirement on
Python 2.

This commit modifies the Python probe behavior to look for python2.7 and
python2 *before* using the interpreter used to execute `x.py`.

These tests currently segfault sometimes. Android is a tier-2 target so
this is fine to disable instead of fixing.

Unfortunately, this isn't quite enough as rustdoc doesn't currently
correctly interpret the --exclude-should-panic flag (i.e., ignores it).
That proved to be harder to fix than I had time for so we're going to
leave it and hope that at least some of the failures are fixed.

… end

In indexmap-rs/indexmap#88, we found that there was no easy way to implement
`Debug` for our `IterMut` and `Drain` iterators. Those are built on
`slice::IterMut` and `vec::Drain`, which implement `Debug` themselves,
but have no other way to access their data. With a new `as_slice()`
method, we can read the data and customize its presentation.

Co-Authored-By: cuviper <cuviper@gmail.com>

…ions required for AccessLevels

…guarantees that it will run immediately

…ompiler

Co-Authored-By: RalfJung <post@ralfj.de>

This commit deletes the `connect_timeout_unbound` test from the standard
library which, unfortunately, is by definition eventually going to be a
spuriously failing test. There's no way to reserve a port as unbound so
we can rely on ecosystem testing for this feature for now.

Closes rust-lang#52590

…r=RalfJung

Use early unwraps instead of bubbling up errors just to unwrap in the end

r? @RalfJung

…llaumeGomez

rustdoc: add option to calculate "documentation coverage"

This PR adds a new flag to rustdoc, `--show-coverage`. When passed, this flag will make rustdoc count the number of items in a crate with documentation instead of generating docs. This count will be output as a table of each file in the crate, like this (when run on my crate `egg-mode`):

```
+-------------------------------------+------------+------------+------------+
| File                                | Documented |      Total | Percentage |
+-------------------------------------+------------+------------+------------+
| src/auth.rs                         |         16 |         16 |     100.0% |
| src/common/mod.rs                   |          1 |          1 |     100.0% |
| src/common/response.rs              |          9 |          9 |     100.0% |
| src/cursor.rs                       |         24 |         24 |     100.0% |
| src/direct/fun.rs                   |          6 |          6 |     100.0% |
| src/direct/mod.rs                   |         41 |         41 |     100.0% |
| src/entities.rs                     |         50 |         50 |     100.0% |
| src/error.rs                        |         27 |         27 |     100.0% |
| src/lib.rs                          |          1 |          1 |     100.0% |
| src/list/fun.rs                     |         19 |         19 |     100.0% |
| src/list/mod.rs                     |         22 |         22 |     100.0% |
| src/media/mod.rs                    |         27 |         27 |     100.0% |
| src/place/fun.rs                    |          8 |          8 |     100.0% |
| src/place/mod.rs                    |         35 |         35 |     100.0% |
| src/search.rs                       |         26 |         26 |     100.0% |
| src/service.rs                      |         74 |         74 |     100.0% |
| src/stream/mod.rs                   |         49 |         49 |     100.0% |
| src/tweet/fun.rs                    |         15 |         15 |     100.0% |
| src/tweet/mod.rs                    |         73 |         73 |     100.0% |
| src/user/fun.rs                     |         24 |         24 |     100.0% |
| src/user/mod.rs                     |         87 |         87 |     100.0% |
+-------------------------------------+------------+------------+------------+
| Total                               |        634 |        634 |     100.0% |
+-------------------------------------+------------+------------+------------+
```

Trait implementations are not counted because by default they "inherit" the docs from the trait, even though an impl can override those docs. Similarly, inherent impl blocks are not counted at all, because for the majority of cases such docs are not useful. (The usual pattern for inherent impl blocks is to throw all the methods on a type into a single impl block. Any docs you would put on that block would be better served on the type itself.)

In addition, `--show-coverage` can be combined with `--document-private-items` to get the coverage counts for everything in the crate, not just public items.

The coverage calculation is implemented as a late pass and two new sets of passes which strip out most of the work that rustdoc otherwise does when generating docs. The is because after the new pass is executed, rustdoc immediately closes instead of going on to generate documentation.

Many examples of coverage calculations have been included as `rustdoc-ui` tests.

r? @rust-lang/rustdoc

rust-lldb: fix crash when printing empty string

Fixes rust-lang#52185.

~Re-enables the pretty-std debuginfo test and tweaks the test as necessary to get it to pass again. This reveals that lldb's formatting of enums is broken (rust-lang#58492). I also removed the emoji from the test because I couldn't get the docker image's gdb to print the emoji, just octal escapes (https://github.com/rust-lang/rust/pull/53154/files#r208263904).~

MaybeUninit: add read_initialized, add examples

This adds a new `read_initialized` method, similar to suggestions by @Amanieu and @shepmaster. I also added examples to this and other methods.

…k_kinds, r=oli-obk

fixes rust-lang#52482

…hton

look for python2 symlinks before bootstrap python

Before this commit, if you're running x.py directly on a system where
`python` is symlinked to Python 3, then the `python` config option will
default to a Python 3 interpreter. This causes debuginfo tests to fail
with an opaque error message, since they have a hard requirement on
Python 2.

This commit modifies the Python probe behavior to look for python2.7 and
python2 *before* using the interpreter used to execute `x.py`.

…ister

Refactor passes and pass execution to be more parallel

For `syntex_syntax` (with 16 threads and 8 cores):
- Cuts `misc checking 1` from `0.096s` to `0.08325s`.
- Cuts `misc checking 2` from `0.3575s` to `0.2545s`.
- Cuts `misc checking 3` from `0.34625s` to `0.21375s`.
- Cuts `wf checking` from `0.3085s` to `0.05025s`.

Reduces overall execution time for `syntex_syntax` (with 8 threads and cores) from `4.92s` to `4.34s`.

Subsumes rust-lang#58494
Blocked on rust-lang#58250

r? @michaelwoerister

…hton

Add tests for several E-needstest issues

This PR adds a number of tests for various `E-needstest` errors. These tend to have been left open for a long time and seem unlikely to be closed otherwise.

Closes rust-lang#10876.
Closes rust-lang#22892.
Closes rust-lang#26448.
Closes rust-lang#26577.
Closes rust-lang#26619.
Closes rust-lang#27054.
Closes rust-lang#28587.
Closes rust-lang#44127.
Closes rust-lang#44255.
Closes rust-lang#55731.
Closes rust-lang#57781.

Make `Unique::as_ptr`, `NonNull::dangling` and `NonNull::cast` const

Mention `unwind(aborts)` in diagnostics for `#[unwind]`

Simplify input validation for `#[unwind]`, add tests

cc rust-lang#58760
r? @Mark-Simulacrum

…-android, r=kennytm

Ignore should_panic tests on android

These tests currently segfault sometimes. Android is a tier-2 target so
this is fine to disable instead of fixing.

Unfortunately, this isn't quite enough as rustdoc doesn't currently
correctly interpret the --exclude-should-panic flag (i.e., ignores it).
That proved to be harder to fix than I had time for so we're going to
leave it and hope that at least some of the failures are fixed.

Hopefully alleviates rust-lang#55861; I don't have the time to investigate fixing rustdoc.

Add as_slice() to slice::IterMut and vec::Drain

In indexmap-rs/indexmap#88, we found that there was no easy way to implement
`Debug` for our `IterMut` and `Drain` iterators. Those are built on
`slice::IterMut` and `vec::Drain`, which implement `Debug` themselves,
but have no other way to access their data. With a new `as_slice()`
method, we can read the data and customize its presentation.

Actually publish miri in the manifest

std: Delete a by-definition spuriously failing test

This commit deletes the `connect_timeout_unbound` test from the standard
library which, unfortunately, is by definition eventually going to be a
spuriously failing test. There's no way to reserve a port as unbound so
we can rely on ecosystem testing for this feature for now.

Closes rust-lang#52590