Commit graph

5605 commits

Author SHA1 Message Date
Jonas Schievink
99f2f5a830
Rollup merge of #80404 - JulianKnodt:arr_ref, r=oli-obk
Remove const_in_array_repeat

Fixes #80371. Fixes #81315. Fixes #80767. Fixes #75682.

I thought there might be some issue with `Repeats(_, 0)`, but if you increase the items in the array it still ICEs. I'm not sure if this is the best fix but it does fix the given issue.
2021-01-31 16:36:42 +01:00
kadmin
6946534d84 Remove const_in_array_rep_expr 2021-01-30 23:20:24 +00:00
Yuki Okushi
d9e56f48c5
Rollup merge of #79570 - alexcrichton:split-debuginfo, r=bjorn3
rustc: Stabilize `-Zrun-dsymutil` as `-Csplit-debuginfo`

This commit adds a new stable codegen option to rustc,
`-Csplit-debuginfo`. The old `-Zrun-dsymutil` flag is deleted and now
subsumed by this stable flag. Additionally `-Zsplit-dwarf` is also
subsumed by this flag but still requires `-Zunstable-options` to
actually activate. The `-Csplit-debuginfo` flag takes one of
three values:

* `off` - This indicates that split-debuginfo from the final artifact is
  not desired. This is not supported on Windows and is the default on
  Unix platforms except macOS. On macOS this means that `dsymutil` is
  not executed.

* `packed` - This means that debuginfo is desired in one location
  separate from the main executable. This is the default on Windows
  (`*.pdb`) and macOS (`*.dSYM`). On other Unix platforms this subsumes
  `-Zsplit-dwarf=single` and produces a `*.dwp` file.

* `unpacked` - This means that debuginfo will be roughly equivalent to
  object files, meaning that it's throughout the build directory
  rather than in one location (often the fastest for local development).
  This is not the default on any platform and is not supported on Windows.

Each target can indicate its own default preference for how debuginfo is
handled. Almost all platforms default to `off` except for Windows and
macOS which default to `packed` for historical reasons.

Some equivalencies for previous unstable flags with the new flags are:

* `-Zrun-dsymutil=yes` -> `-Csplit-debuginfo=packed`
* `-Zrun-dsymutil=no` -> `-Csplit-debuginfo=unpacked`
* `-Zsplit-dwarf=single` -> `-Csplit-debuginfo=packed`
* `-Zsplit-dwarf=split` -> `-Csplit-debuginfo=unpacked`

Note that `-Csplit-debuginfo` still requires `-Zunstable-options` for
non-macOS platforms since split-dwarf support was *just* implemented in
rustc.

There's some more rationale listed on #79361, but the main gist of the
motivation for this commit is that `dsymutil` can take quite a long time
to execute in debug builds and provides little benefit. This means that
incremental compile times appear that much worse on macOS because the
compiler is constantly running `dsymutil` over every single binary it
produces during `cargo build` (even build scripts!). Ideally rustc would
switch to not running `dsymutil` by default, but that's a problem left
to get tackled another day.

Closes #79361
2021-01-29 09:17:20 +09:00
Alex Crichton
a124043fb0 rustc: Stabilize -Zrun-dsymutil as -Csplit-debuginfo
This commit adds a new stable codegen option to rustc,
`-Csplit-debuginfo`. The old `-Zrun-dsymutil` flag is deleted and now
subsumed by this stable flag. Additionally `-Zsplit-dwarf` is also
subsumed by this flag but still requires `-Zunstable-options` to
actually activate. The `-Csplit-debuginfo` flag takes one of
three values:

* `off` - This indicates that split-debuginfo from the final artifact is
  not desired. This is not supported on Windows and is the default on
  Unix platforms except macOS. On macOS this means that `dsymutil` is
  not executed.

* `packed` - This means that debuginfo is desired in one location
  separate from the main executable. This is the default on Windows
  (`*.pdb`) and macOS (`*.dSYM`). On other Unix platforms this subsumes
  `-Zsplit-dwarf=single` and produces a `*.dwp` file.

* `unpacked` - This means that debuginfo will be roughly equivalent to
  object files, meaning that it's throughout the build directory
  rather than in one location (often the fastest for local development).
  This is not the default on any platform and is not supported on Windows.

Each target can indicate its own default preference for how debuginfo is
handled. Almost all platforms default to `off` except for Windows and
macOS which default to `packed` for historical reasons.

Some equivalencies for previous unstable flags with the new flags are:

* `-Zrun-dsymutil=yes` -> `-Csplit-debuginfo=packed`
* `-Zrun-dsymutil=no` -> `-Csplit-debuginfo=unpacked`
* `-Zsplit-dwarf=single` -> `-Csplit-debuginfo=packed`
* `-Zsplit-dwarf=split` -> `-Csplit-debuginfo=unpacked`

Note that `-Csplit-debuginfo` still requires `-Zunstable-options` for
non-macOS platforms since split-dwarf support was *just* implemented in
rustc.

There's some more rationale listed on #79361, but the main gist of the
motivation for this commit is that `dsymutil` can take quite a long time
to execute in debug builds and provides little benefit. This means that
incremental compile times appear that much worse on macOS because the
compiler is constantly running `dsymutil` over every single binary it
produces during `cargo build` (even build scripts!). Ideally rustc would
switch to not running `dsymutil` by default, but that's a problem left
to get tackled another day.

Closes #79361
2021-01-28 08:51:11 -08:00
Yuki Okushi
9da36082c2
Rollup merge of #81399 - ehuss:update-books, r=ehuss
Update books

## nomicon

7 commits in a8584998eacdea7106a1dfafcbf6c1c06fcdf925..bbf06ad39d1f45654047e9596b750cc6e6d1b693
2021-01-06 12:49:49 -0500 to 2021-01-22 07:07:31 -0800
- Fix alloc link in exotic-sizes for local docs (rust-lang-nursery/nomicon#255)
- Remove TODO
- Fix small punctuation error
- Arc revisions (Clone atomic explanation) (pt2/3(+?))
- Fix Arc Clone
- Arc revisions (pt1/2(+?))
- Simple Arc implementation (without Weak refs)

## reference

5 commits in 50af691f838937c300b47812d0507c6d88c14f97..f02b09eb6e8af340ad1256a54adb7aae2ff3163e
2021-01-12 21:19:20 -0800 to 2021-01-22 01:53:02 -0800
- Fix missing space (rust-lang-nursery/reference#941)
- Start documenting name resolution. (rust-lang-nursery/reference#937)
- Fix plural and delete spurious words in comparison ops (rust-lang-nursery/reference#932)
- Document execution order (rust-lang-nursery/reference#888)
- Compound operator expressions (rust-lang-nursery/reference#915)

## book

3 commits in ac57a0ddd23d173b26731ccf939f3ba729753275..e724bd826580ff95df48a8533af7dec1080693d4
2021-01-09 14:18:45 -0500 to 2021-01-20 08:19:49 -0600
- Fixes rust-lang/book#2417. Get the index from user input instead of a const. (rust-lang/book#2566)
- Turn off the playground in a bunch more lib.rs inclusions (rust-lang/book#2569)
- Merge pull request rust-lang/book#2567 from rust-lang/rust-1.49

## rust-by-example

1 commits in 03e23af01f0b4f83a3a513da280e1ca92587f2ec..f633769acef68574427a6fae6c06f13bc2199573
2021-01-09 10:20:28 -0300 to 2021-01-13 20:58:25 -0300
- Fixed styling on closure example (rust-lang/rust-by-example#1405)
2021-01-27 04:43:32 +09:00
Eric Huss
fdd592acd0 Update books 2021-01-25 15:10:10 -08:00
Eric Huss
1c0a52d304 rustdoc: Document CommonMark extensions. 2021-01-25 11:03:15 -08:00
Joshua Nelson
fc53594756 Feature-gate pointer and reference in intra-doc links
- Only feature gate associated items
- Add docs to unstable book
2021-01-17 15:27:35 -05:00
Mara Bos
3fe37c3830
Rollup merge of #80973 - ehuss:update-books, r=ehuss
Update books

## nomicon

2 commits in a5a48441d411f61556b57d762b03d6874afe575d..a8584998eacdea7106a1dfafcbf6c1c06fcdf925
2020-12-06 10:39:41 +0900 to 2021-01-06 12:49:49 -0500
- Update vector code examples
- Remove outdated information about `jemalloc`

## reference

13 commits in b278478b766178491a8b6f67afa4bcd6b64d977a..50af691f838937c300b47812d0507c6d88c14f97
2020-12-21 18:18:03 -0800 to 2021-01-12 21:19:20 -0800
- Update grammar for parser unification. (rust-lang/reference#927)
- Define constraining an implementation (rust-lang/reference#928)
- Document extra behavior of #[no_mangle] (rust-lang/reference#930)
- Add a float examle without a `.`. (rust-lang/reference#929)
- Add more details about const generics. (rust-lang/reference#921)
- Fix footnotes. (rust-lang/reference#926)
- Add "Logic errors" as behavior not considered unsafe (rust-lang/reference#919)
- Update grammar for order of parameters/arguments. (rust-lang/reference#920)
- Fix formatting in the tuple section (rust-lang/reference#923)
- document const generics (rust-lang/reference#901)
- Update mdbook (rust-lang/reference#918)
- linkage.md: update link to FFI section of the Book. (rust-lang/reference#917)
- Document array expression with a const. (rust-lang/reference#914)

## book

8 commits in 5bb44f8b5b0aa105c8b22602e9b18800484afa21..ac57a0ddd23d173b26731ccf939f3ba729753275
2020-12-18 20:07:31 -0500 to 2021-01-09 14:18:45 -0500
- Update version of mdbook we're testing with to 0.4.5 (rust-lang/book#2561)
- Fix grammar in ch13-01-closures.md (rust-lang/book#2534)
- Merge remote-tracking branch 'origin/pr/2527'
- Clarify code example ch6.3 (rust-lang/book#2485)
- Fix link added in rust-lang/book#2495 to be relative and at the bottom
- Merge remote-tracking branch 'origin/pr/2495'
- Update output to match the updated poem punctuation
- Fix rust-lang/book#2539 - Remove fancy apostrophes from poem for Windows

## rust-by-example

3 commits in 1cce0737d6a7d3ceafb139b4a206861fb1dcb2ab..03e23af01f0b4f83a3a513da280e1ca92587f2ec
2020-12-21 17:36:29 -0300 to 2021-01-09 10:20:28 -0300
- Replace for loop with iteration (rust-lang/rust-by-example#1404)
- Update mdbook (rust-lang/rust-by-example#1402)
- Add note for match guards to include catch-all (rust-lang/rust-by-example#1401)

## embedded-book

1 commits in ba34b8a968f9531d38c4dc4411d5568b7c076bfe..ceec19e873be87c6ee5666b030c6bb612f889a96
2020-11-17 00:20:43 +0000 to 2021-01-03 13:13:10 +0000
- book.toml: add link to GitHub repo  (rust-embedded/book#276)
2021-01-14 18:00:20 +00:00
Mark Rousskov
8a3edb1d66 Update tests for extern block linting 2021-01-13 07:49:16 -05:00
Eric Huss
6bfd987aa0 Update books 2021-01-12 21:20:21 -08:00
Ikko Ashimine
9ca80a29ec
Fix typo in source-based-code-coverage.md
preceeding -> preceding
2021-01-10 22:17:51 +09:00
Corey Farwell
d482de30ea Merge remote-tracking branch 'origin/master' into frewsxcv-san 2020-12-31 23:27:33 -05:00
Ikko Ashimine
02db77c2d1
Fix typo in ffi-pure.md
accesing -> accessing
2020-12-29 13:37:21 +09:00
Mara Bos
7800c70fab
Rollup merge of #80410 - MarcoIeni:patch-1, r=jonas-schievink
rustdoc book: fix example

`lib.rs` file is created only if `--lib` flag is specified
2020-12-28 19:09:29 +00:00
Mara Bos
bae6475443
Rollup merge of #80393 - ehuss:doc-git-link, r=jyn514
Add links to the source for the rustc and rustdoc books.

This adds a little icon in the upper-right corner of the books so that readers can find the source if they want to make changes or file issues. This is already included in several of the other books.
2020-12-28 19:09:22 +00:00
Marco Ieni
f57152f640
rustdoc book: fix example 2020-12-27 14:10:00 +01:00
bors
dc6121ca68 Auto merge of #79642 - ijackson:default-theme-stab, r=jyn514
rustdoc: stabilise --default-theme command line option

As discussed in #77213, this seems like it has bedded in and can be safely and usefully made stable.

(rustdoc already has other stable options that interact quite intimately with the rustdoc-supplied CSS, and also an option for supplying entirely different CSS, so exposing the theme names this way seems a very minor step.)

There is also a commit to do some minor grammar fixes to the help message.
2020-12-27 09:55:51 +00:00
Eric Huss
6dab9265c8 Fix missing deny-by-default.md file. 2020-12-26 13:53:10 -08:00
Eric Huss
142764f79e Add links to the source for the rustc and rustdoc books. 2020-12-26 13:22:33 -08:00
bors
1832bdd7de Auto merge of #80296 - wesleywiser:revert_missing_fragment_specifier_hard_error, r=Mark-Simulacrum
Revert missing fragment specifier hard error

Closes #76605

Reopens #40107

r? `@Mark-Simulacrum`
2020-12-25 14:09:08 +00:00
Wesley Wiser
9414f0b833 Revert "Remove missing_fragment_specifier lint"
This reverts commit 5ba961018c.
2020-12-22 08:35:52 -05:00
Eric Huss
1339c81390 Update books 2020-12-21 19:00:49 -08:00
EFanZh
7662626f77
Fix cargo-binutils link 2020-12-13 19:23:16 +08:00
Tyler Mandry
8709ac81d3
Rollup merge of #79858 - sasurau4:doc/update-unstable-book-const-fn, r=oli-obk
Update const-fn doc in unstable-book

Fix #79691

I couldn't find suitable examples. It seems that `const_fn` feature-gate used only following place. 810324d1f3/compiler/rustc_ast_passes/src/feature_gate.rs (L560-L562)

And example like following emits [E0379](https://doc.rust-lang.org/error-index.html#E0379).

```rust
#![feature(const_fn)]

trait Foo {
    const fn bar() -> Self;
}
```

Any other suitable example exists, please let me know.
2020-12-10 21:33:12 -08:00
Corey Farwell
7ee606f514 Update sanitizer supported docs to reflect reality 2020-12-10 19:11:58 -05:00
Daiki Ihara
caab16fa20 Update const-fn doc in unstable-book
Update src/doc/unstable-book/src/language-features/const-fn.md

Co-authored-by: Ivan Tham <pickfire@riseup.net>
2020-12-10 22:29:43 +09:00
Rich Kadel
95c268f64d Fixes to Rust coverage
Fixes: #79725

Some macros can create a situation where `fn_sig_span` and `body_span`
map to different files.

New documentation on coverage tests incorrectly assumed multiple test
binaries could just be listed at the end of the `llvm-cov` command,
but it turns out each binary needs a `--object` prefix.

This PR fixes the bug and updates the documentation to correct that
issue. It also fixes a few other minor issues in internal implementation
comments, and adds documentation on getting coverage results for doc
tests.
2020-12-07 17:56:19 -08:00
Rich Kadel
d96f351fa3 Addressed feedback from 2020-12-01
Added one more test (two files) showing coverage of generics and unused
functions across crates.

Created and referenced new Issues, as requested.

Added comments.

Added a note about the possible effects of compiler options on LLVM
coverage maps.
2020-12-03 09:50:10 -08:00
Rich Kadel
def932ca86 Combination of commits
Fixes multiple issue with counters, with simplification

  Includes a change to the implicit else span in ast_lowering, so coverage
  of the implicit else no longer spans the `then` block.

  Adds coverage for unused closures and async function bodies.

  Fixes: #78542

Adding unreachable regions for known MIR missing from coverage map

Cleaned up PR commits, and removed link-dead-code requirement and tests

  Coverage no longer depends on Issue #76038 (`-C link-dead-code` is
  no longer needed or enforced, so MSVC can use the same tests as
  Linux and MacOS now)

Restrict adding unreachable regions to covered files

  Improved the code that adds coverage for uncalled functions (with MIR
  but not-codegenned) to avoid generating coverage in files not already
  included in the files with covered functions.

Resolved last known issue requiring --emit llvm-ir workaround

  Fixed bugs in how unreachable code spans were added.
2020-12-03 09:50:10 -08:00
Rich Kadel
c45ee4bb29 Coverage tests for remaining TerminatorKinds and async, improve Assert
Tested and validate results for panic unwind, panic abort, assert!()
macro, TerminatorKind::Assert (for example, numeric overflow), and
async/await.

Implemented a previous documented idea to change Assert handling to be
the same as FalseUnwind and Goto, so it doesn't get its own
BasicCoverageBlock anymore. This changed a couple of coverage regions,
but I validated those changes are not any worse than the prior results,
and probably help assure some consistency (even if some people might
disagree with how the code region is consistently computed).

Fixed issue with async/await. AggregateKind::Generator needs to be
handled like AggregateKind::Closure; coverage span for the outer async
function should not "cover" the async body, which is actually executed
in a separate "closure" MIR.
2020-12-03 09:50:09 -08:00
Ian Jackson
63f3876b85
fix typo in src/doc/rustdoc/src/command-line-arguments.md
Co-authored-by: Guillaume Gomez <guillaume1.gomez@gmail.com>
2020-12-03 10:22:57 +00:00
Ian Jackson
c21b275d35 rustdoc: document --default-theme option in command line doc
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
2020-12-03 00:50:37 +00:00
bors
6645da366e Auto merge of #78684 - devsnek:inline-asm-wasm, r=Amanieu
Add wasm32 support to inline asm

There is some contention around inline asm and wasm, and I really only made this to figure out the process of hacking on rustc, but I figured as long as the code existed, it was worth uploading.

cc `@Amanieu`
2020-12-01 20:23:06 +00:00
Gus Caplan
d9f237caa6
Add wasm32 support to inline asm 2020-12-01 12:18:21 -06:00
Mara Bos
c06a00e21d
Rollup merge of #79583 - ehuss:update-books, r=ehuss
Update books

## nomicon

1 commits in 23c49f1d5ce4720bc5b7e3a920f47eccc8da6b63..d8383b65f7948c2ca19191b3b4bd709b403aaf45
2020-11-05 13:30:53 +0900 to 2020-11-22 10:24:42 -0500
- Clarify that any alignment is valid for ZSTs

## reference

5 commits in a7de763c213292f5b44bf10acb87ffa38724814d..a8afdca5d0715b2257b6f8b9a032fd4dd7dae855
2020-11-11 19:13:21 -0800 to 2020-11-30 06:44:46 -0800
- Describe relationship between reference and optimizers (rust-lang/reference#902)
- A simple missing space (rust-lang/reference#909)
- Cleanup formatting (rust-lang/reference#907)
- Use `doc`, not `test` for fn item inner attr example (rust-lang/reference#906)
- Update where our chat is. (rust-lang/reference#903)

## book

1 commits in 13e1c05420bca86ecc79e4ba5b6d02de9bd53c62..a190438d77d28041f24da4f6592e287fab073a61
2020-10-20 14:57:32 -0500 to 2020-11-16 10:44:08 -0600
- Change SipHash not found (404) link to SipHash in Wikipedia (rust-lang/book#2503)

## rust-by-example

4 commits in 1886fda6981b723e4de637074455558f8bc1e83c..236c734a2cb323541b3394f98682cb981b9ec086
2020-10-28 13:46:54 -0500 to 2020-11-30 14:05:49 -0300
- Update old invalid link (rust-lang/rust-by-example#1392)
- Moved "See also" link to the correct page. (rust-lang/rust-by-example#1389)
- Fix some markdown lint warnings (rust-lang/rust-by-example#1388)
- Minor grammar suggestion (rust-lang/rust-by-example#1386)

## embedded-book

1 commits in ca8169e69b479f615855d0eece7e318138fcfc00..ba34b8a968f9531d38c4dc4411d5568b7c076bfe
2020-10-15 15:06:35 +0000 to 2020-11-17 00:20:43 +0000
- Clarify CAS availability  (rust-embedded/book#273)
2020-12-01 10:50:26 +00:00
Mara Bos
2891f3ff3d
Rollup merge of #79573 - he32:master, r=jonas-schievink
Update with status for various NetBSD ports.

The NetBSD ports of rust to aarch64, armv7*, i686, and powerpc**
all both build and run.  Status is as of rust 1.47.0.

*) Natively requires repeated successive build attempts (`rustc` is
   such a resource pig VM-consumption-wise), or run in a chroot
   on an aarch64 host where the available VM space is 4GB instead
   of the native 2GB.
**) Powerpc either requires `-latomic` in a directory searched by
   default by `ld` or to be built within pkgsrc which has a patch and
   support package to tackle this issue.
2020-12-01 10:50:25 +00:00
Eric Huss
9ba8d6e234 Update books 2020-11-30 17:25:23 -08:00
Havard Eidnes
1c367c0a70 Update with status for various NetBSD ports.
The NetBSD ports of rust to aarch64, armv7*, i686, and powerpc**
all both build and run.

*) Natively requires repeated successive build attempts (rustc is
   such a resource pig VM-consumption-wise), or run in a chroot
   on an aarch64 host where the available VM space is 4GB instead
   of the native 2GB.
**) Powerpc either requires -latomic in a directory searched by
   default by 'ld' or to be built within pkgsrc which has a patch
   to tackle this.
2020-11-30 19:18:21 +01:00
Ondrej Perutka
b2ad73e8a4 Add built-in support for the armv5te-unknown-linux-uclibceabi target 2020-11-30 09:47:09 +01:00
Benedikt Terhechte
836d43933d Add to platform-support.md 2020-11-26 11:33:38 +01:00
Benedikt Terhechte
96779647c4 Add support for Arm64 Catalyst on ARM Macs 2020-11-26 11:31:59 +01:00
bors
ec039bd075 Auto merge of #79336 - camelid:rename-feature-oibit-to-auto, r=oli-obk
Rename `optin_builtin_traits` to `auto_traits`

They were originally called "opt-in, built-in traits" (OIBITs), but
people realized that the name was too confusing and a mouthful, and so
they were renamed to just "auto traits". The feature flag's name wasn't
updated, though, so that's what this PR does.

There are some other spots in the compiler that still refer to OIBITs,
but I don't think changing those now is worth it since they are internal
and not particularly relevant to this PR.

Also see <https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/opt-in.2C.20built-in.20traits.20(auto.20traits).20feature.20name>.

r? `@oli-obk` (feel free to re-assign if you're not the right reviewer for this)
2020-11-25 07:25:19 +00:00
Jonas Schievink
8fde4be7d0
Rollup merge of #76858 - rcvalle:rust-lang-exploit-mitigations, r=steveklabnik
Add exploit mitigations chapter to the rustc book

This section documents the exploit mitigations applicable to the Rust compiler when building programs for the Linux operating system on the AMD64 architecture and equivalent. This was done for a project I'm currently working on, and I hope it'll also be helpful to others.
2020-11-24 13:17:28 +01:00
Ramon de C Valle
5b1cb0eb8a Add exploit mitigations chapter to the rustc book
This section documents the exploit mitigations applicable to the Rust
compiler when building programs for the Linux operating system on the
AMD64 architecture and equivalent.
2020-11-23 19:25:59 -08:00
Camelid
810324d1f3 Rename optin_builtin_traits to auto_traits
They were originally called "opt-in, built-in traits" (OIBITs), but
people realized that the name was too confusing and a mouthful, and so
they were renamed to just "auto traits". The feature flag's name wasn't
updated, though, so that's what this PR does.

There are some other spots in the compiler that still refer to OIBITs,
but I don't think changing those now is worth it since they are internal
and not particularly relevant to this PR.

Also see <https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/opt-in.2C.20built-in.20traits.20(auto.20traits).20feature.20name>.
2020-11-23 14:14:06 -08:00
Lzu Tao
6bfe27a3e0 Drop support for cloudabi targets 2020-11-22 17:11:41 -05:00
Mara Bos
11ce918c75
Rollup merge of #78714 - m-ou-se:simplify-local-streams, r=KodrAus
Simplify output capturing

This is a sequence of incremental improvements to the unstable/internal `set_panic` and `set_print` mechanism used by the `test` crate:

1. Remove the `LocalOutput` trait and use `Arc<Mutex<dyn Write>>` instead of `Box<dyn LocalOutput>`. In practice, all implementations of `LocalOutput` were just `Arc<Mutex<..>>`. This simplifies some logic and removes all custom `Sink` implementations such as `library/test/src/helpers/sink.rs`. Also removes a layer of indirection, as the outermost `Box` is now gone. It also means that locking now happens per `write_fmt`, not per individual `write` within. (So `"{} {}\n"` now results in one `lock()`, not four or more.)

2. Since in all cases the `dyn Write`s were just `Vec<u8>`s, replace the type with `Arc<Mutex<Vec<u8>>>`. This simplifies things more, as error handling and flushing can be removed now. This also removes the hack needed in the default panic handler to make this work with `::realstd`, as (unlike `Write`) `Vec<u8>` is from `alloc`, not `std`.

3. Replace the `RefCell`s by regular `Cell`s. The `RefCell`s were mostly used as `mem::replace(&mut *cell.borrow_mut(), something)`, which is just `Cell::replace`. This removes an unecessary bookkeeping and makes the code a bit easier to read.

4. Merge `set_panic` and `set_print` into a single `set_output_capture`. Neither the test crate nor rustc (the only users of this feature) have a use for using these separately. Merging them simplifies things even more. This uses a new function name and feature name, to make it clearer this is internal and not supposed to be used by other crates.

Might be easier to review per commit.
2020-11-16 17:26:27 +01:00
Eric Huss
a8bc9545eb Update books 2020-11-11 19:35:50 -08:00
Mara Bos
aff7bd66e8 Merge set_panic and set_print into set_output_capture.
There were no use cases for setting them separately.
Merging them simplifies some things.
2020-11-10 21:58:13 +01:00