Dylan DPC [Tue, 30 Mar 2021 09:34:29 +0000 (11:34 +0200)]
Rollup merge of #83662 - ehuss:update-books, r=ehuss
Update books
## reference
4 commits in d10a0af8dca25d9d548ca6a369fd66ad06acb3c9..fd97729e2d82f8b08d68a31c9bfdf0c37a7fd542
2021-03-21 11:14:06 -0700 to 2021-03-28 14:29:19 -0700
- Editorial cleanup on expressions (part 1) (rust-lang-nursery/reference#967)
- Update type casts section (rust-lang-nursery/reference#961)
- Add missing "?" notion (rust-lang-nursery/reference#989)
- Fix typo (rust-lang-nursery/reference#988)
## book
8 commits in fc2f690fc16592abbead2360cfc0a42f5df78052..b54090a99ec7c4b46a5203a9c927fdbc311bb1f5
2021-03-05 14:03:22 -0500 to 2021-03-24 11:21:46 -0500
- correct the signature of the `deref` method (rust-lang/book#2658)
- Clarify the immutability of a reference (rust-lang/book#2646)
- Tweak wording around Windows representation of enter
- Ch. 02 note - Enter results in CRLF on Windows (rust-lang/book#2648)
- Added an example of slicing result (rust-lang/book#2649)
- Fix word wrapping, mention dictionary.txt is also in the ci dir
- README: note that spellcheck.sh is in ci directory (rust-lang/book#2652)
- Change someurl.com to example.org (rust-lang/book#2655)
## rust-by-example
12 commits in eead22c6c030fa4f3a167d1798658c341199e2ae..29d91f591c90dd18fdca6d23f1a9caf9c139d0d7
2021-03-04 16:26:43 -0300 to 2021-03-23 09:03:39 -0300
- Unwrap some drinks. (rust-lang/rust-by-example#1431)
- doc(testcase_linked_list): add a little extra note about pattern (rust-lang/rust-by-example#1408)
- Update function name in comment (rust-lang/rust-by-example#1413)
- Fixes minor typo in src/types/cast.md (rust-lang/rust-by-example#1414)
- Add destructuring example to generics new type (rust-lang/rust-by-example#1416)
- update struct.md (rust-lang/rust-by-example#1419)
- fix name from rectangle to Rectangle (rust-lang/rust-by-example#1420)
- Typo "incures" in code comment (rust-lang/rust-by-example#1422)
- Changed impl to use Self::Item (rust-lang/rust-by-example#1425)
- Fix code highlighting in some places (rust-lang/rust-by-example#1427)
- Update multi_bounds.md (rust-lang/rust-by-example#1428)
- Reformulated text for redability (rust-lang/rust-by-example#1429)
## rustc-dev-guide
3 commits in 67ebd4b55dba44edfc351621cef6e5e758169c55..0687daac28939c476df51778f5a1d1aff1a3fddf
2021-03-11 13:36:25 -0800 to 2021-03-28 13:33:56 -0400
- Add notes about nightly rustc version for the rustc-driver examples
- Update rustc-driver-*.rs examples (rust-lang/rustc-dev-guide#1095)
- Fix rust compiler meeting info (rust-lang/rustc-dev-guide#1087)
Dylan DPC [Tue, 30 Mar 2021 09:34:26 +0000 (11:34 +0200)]
Rollup merge of #83579 - RalfJung:ptr-arithmetic, r=dtolnay
Improve pointer arithmetic docs
* Add slightly more detailed definition of "allocated object" to the module docs, and link it from everywhere.
* Clarify the "remains attached" wording a bit (at least I hope this is clearer).
* Remove the sentence about using integer arithmetic; this seems to confuse people even if it is technically correct.
As usual, the edit needs to be done in a dozen places to remain consistent, I hope I got them all.
Dylan DPC [Tue, 30 Mar 2021 09:34:25 +0000 (11:34 +0200)]
Rollup merge of #83571 - a1phyr:feature_const_slice_first_last, r=dtolnay
Constantify some slice methods
Tracking issue: #83570
This PR constantifies the following functions under feature `const_slice_first_last`:
- `slice::first`
- `slice::split_first`
- `slice::last`
- `slice::split_last`
bors [Tue, 30 Mar 2021 06:22:29 +0000 (06:22 +0000)]
Auto merge of #83649 - bjorn3:dedup_providers, r=petrochenkov
Don't duplicate the extern providers once for each crate
This should give a small perf improvement for small crates by avoiding a memcpy of a pretty big struct for each loaded crate. In addition would be useful for replacing the sequential `CrateNum` everywhere with the hash based `StableCrateId` introduced in #81635, which would allow avoiding remapping of `CrateNum`'s when loading crate metadata. While this PR is not strictly needed for that, it is necessary to prevent a performance loss due to it.
I think this duplication was done in https://github.com/rust-lang/rust/pull/40008 (which introduced the query system) to make it possible to compile multiple crates in a single session in the future. I think this is unlikely to be implemented any time soon. In addition this PR can easily be reverted if necessary to implement this.
bors [Tue, 30 Mar 2021 03:41:14 +0000 (03:41 +0000)]
Auto merge of #83357 - saethlin:vec-reserve-inlining, r=dtolnay
Reduce the impact of Vec::reserve calls that do not cause any allocation
I think a lot of callers expect `Vec::reserve` to be nearly free when no resizing is required, but unfortunately that isn't the case. LLVM makes remarkably poor inlining choices (along the path from `Vec::reserve` to `RawVec::grow_amortized`), so depending on the surrounding context you either get a huge blob of `RawVec`'s resizing logic inlined into some seemingly-unrelated function, or not enough inlining happens and/or the actual check in `needs_to_grow` ends up behind a function call. My goal is to make the codegen for `Vec::reserve` match the mental that callers seem to have: It's reliably just a `sub cmp ja` if there is already sufficient capacity.
This patch has the following impact on the serde_json benchmarks: https://github.com/serde-rs/json-benchmark/tree/ca3efde8a5b75ff59271539b67452911860248c7 run with `cargo +stage1 run --release -- -n 1024`
That's approximately a one-third increase in throughput on two of the benchmarks, and no effect on one (The benchmark suite has sufficient jitter that I could pick a run where there are no regressions, so I'm not convinced they're meaningful here).
This also produces perf increases on the order of 3-5% in a few other microbenchmarks that I'm tracking. It might be useful to see if this has a cascading effect on inlining choices in some large codebases.
Compiling this simple program demonstrates the change in codegen that causes the perf impact:
```rust
fn main() {
reserve(&mut Vec::new());
}
bors [Tue, 30 Mar 2021 01:16:08 +0000 (01:16 +0000)]
Auto merge of #83664 - Dylan-DPC:rollup-wx6idpd, r=Dylan-DPC
Rollup of 7 pull requests
Successful merges:
- #82331 (alloc: Added `as_slice` method to `BinaryHeap` collection)
- #83130 (escape_ascii take 2)
- #83374 (unix: Fix feature(unix_socket_ancillary_data) on macos and other BSDs)
- #83543 (Lint on unknown intra-doc link disambiguators)
- #83636 (Add a regression test for issue-82792)
- #83643 (Remove a FIXME resolved by #73578)
- #83644 (:arrow_up: rust-analyzer)
Dylan DPC [Mon, 29 Mar 2021 22:32:21 +0000 (00:32 +0200)]
Rollup merge of #83374 - reyk:fix/bsd-ancillary, r=joshtriplett
unix: Fix feature(unix_socket_ancillary_data) on macos and other BSDs
This adds support for CMSG handling on macOS and fixes it on OpenBSD and possibly other BSDs.
When traversing the CMSG list, the previous code had an exception for Android where the next element after the last pointer could point to the first pointer instead of NULL. This is actually not specific to Android: the `libc::CMSG_NXTHDR` implementation for Linux and emscripten have a special case to return NULL when the length of the previous element is zero; most other implementations simply return the previous element plus a zero offset in this case.
This MR makes the check non-optional which fixes CMSG handling and a possible endless loop on such systems; tested with file descriptor passing on OpenBSD, Linux, and macOS.
This MR additionally adds `SocketAncillary::is_empty` because clippy is right that it should be added.
This belongs to the `feature(unix_socket_ancillary_data)` tracking issue: https://github.com/rust-lang/rust/issues/76915
Dylan DPC [Mon, 29 Mar 2021 22:32:20 +0000 (00:32 +0200)]
Rollup merge of #83130 - clarfonthey:escape, r=m-ou-se
escape_ascii take 2
The previous PR, #73111 was closed for inactivity; since I've had trouble in the past reopening closed PRs, I'm just making a new one.
I'm still running the tests locally but figured I'd open the PR in the meantime. Will fix whatever errors show up so we don't have to wait again for this.
Dylan DPC [Mon, 29 Mar 2021 22:32:18 +0000 (00:32 +0200)]
Rollup merge of #82331 - frol:feat/std-binary-heap-as-slice, r=Amanieu
alloc: Added `as_slice` method to `BinaryHeap` collection
I initially asked about whether it is useful addition on https://internals.rust-lang.org/t/should-i-add-as-slice-method-to-binaryheap/13816, and it seems there were no objections, so went ahead with this PR.
> There is [`BinaryHeap::into_vec`](https://doc.rust-lang.org/std/collections/struct.BinaryHeap.html#method.into_vec), but it consumes the value. I wonder if there is API design limitation that should be taken into account. Implementation-wise, the inner buffer is just a Vec, so it is trivial to expose as_slice from it.
Please, guide me through if I need to add tests or something else.
bors [Mon, 29 Mar 2021 22:27:16 +0000 (22:27 +0000)]
Auto merge of #82864 - jyn514:short-circuit, r=GuillaumeGomez
rustdoc: Don't enter an infer_ctxt in get_blanket_impls for impls that aren't blanket impls
Less broken version of https://github.com/rust-lang/rust/pull/82856.
get_blanket_impls is a *very* hot region of rustdoc, so even small changes like this should help. Unfortunately I don't have benchmarks for this until https://github.com/rust-lang/rustc-perf/pull/802 is merged.
Found with https://github.com/est31/warnalyzer.
See https://github.com/rust-lang/rust/pull/77739 for a similar change in the past.
Dubious changes:
- Maybe some of the dead code in rustc_data_structures should be kept, in case someone wants to use it in the future?
TODO:
- [ ] check if any of the comments on the deleted code should be kept.
- [x] update the compiler documentation; right now it fails to build
- [x] finish moving `cfg(test)` changes into https://github.com/rust-lang/rust/pull/83197
Joshua Nelson [Mon, 29 Mar 2021 17:50:40 +0000 (13:50 -0400)]
Revert changes to sync data structures
There isn't currently a good reviewer for these, and I don't want to
remove things that will just be added again. I plan to make a separate
PR for these changes so the rest of the cleanup can land.
bors [Mon, 29 Mar 2021 16:48:45 +0000 (16:48 +0000)]
Auto merge of #80839 - tblah:riscv64linux_links, r=Mark-Simulacrum
Riscv64linux Test fixes
Get tests passing again using the riscv64gc-unknown-linux-gnu docker image.
Test with
```
src/ci/docker/run.sh riscv64gc-linux
```
## linkcheck
Linkcheck tests that interdocument links in the documentation are correct. Some interdocument links go between rustc and tools (such as rustdoc and cargo). When cross compiling, rustc is built for the host while some tools are built for the target. This goes for the documentation too. Because of this, links in the rustc documentation reffering to cargo or rustdoc documentation look broken.
This issue is worked around by disabling linkcheck for cross compilation builds.
## run-make tests
#78911 seems to happen because `--target` was not passed to `rustc`, but the target linker was specified, causing the target linker to be called with options intended for the host.
Resolves #78911
In a separate issue, `issue-36710` was trying to run a binary built for the target on the host system. This will not work for any platform using `remote-test-server`/`client` (such as riscv64). I don't know of a way of skipping those platforms specifically, so I set this test to skip only on riscv64 for now.
bors [Mon, 29 Mar 2021 11:20:25 +0000 (11:20 +0000)]
Auto merge of #83637 - bjorn3:sync_cg_clif-2021-03-29, r=bjorn3
Sync rustc_codegen_cranelift
The main highlight of this sync is support for cross-compiling to Windows using MinGW. Native compilation with MinGW would also work I think, but using the MSVC toolchain is not yet supported as PE TLS is not yet implemented. Another nice improvement is that crate metadata is now loaded using mmap instead of by reading files. This improves compilation time a bit.
bors [Mon, 29 Mar 2021 08:27:59 +0000 (08:27 +0000)]
Auto merge of #83565 - RalfJung:miri, r=oli-obk
update Miri, and also run test suite with mir-opt-level=4
In the Miri repo, we run the Miri test suite once with default flags and once with `-O -Zmir-opt-level=4`. This helps identify and document situations where MIR optimizations mask UB -- it is okay for that to happen, but it might be god to look into it when it does happen. Recently these tests failed fairly frequently as new MIR optimizations were added, and since we only run them on the Miri side, it is not even clear which rustc PR introduced the change. So I propose we also run these tests in the rustc repo, such that toolstate tracking will tell us the exact PR (or at least the rollup) that caused the change.
bors [Mon, 29 Mar 2021 00:17:23 +0000 (00:17 +0000)]
Auto merge of #83605 - RalfJung:unaligned, r=petrochenkov
unaligned_references: align(N) fields in packed(N) structs are fine
This removes some false positives from the unaligned_references lint: in a `repr(packed(2))` struct, fields of alignment 2 (and less) are guaranteed to be properly aligned, so we do not have to consider them "disaligned".
Tom Eccles [Tue, 16 Mar 2021 18:22:21 +0000 (18:22 +0000)]
test: run-make: skip tests on unsupported platforms
The tests issue-36710 and incr-prev-body-beyond-eof were changed in a
previous commit so that the correct target was passed to rustc
(previously rustc was building for the host not for the specific
target).
Since that change it turns out that these platforms never worked (they
only appeared to work because rustc was actually building for the host
architecture).
The wasm architectures fall over trying to build the C++ file in
issue-36710. They look for clang (which isn't installed in the
test-various docker container). If clang is installed, they can't find
a wasm c++ standard library to link to.
nvtptx64-nvidia-cuda fails in rustc saying it can't find std. The rust
platforms support page says that std is supported on cuda so this is
surprising.
dist-i586-gnu-i586-i686-musl can't find the C++ compiler. There is only
a musl-gcc and no musl-g++ in /musl-i586/bin/. The Docker image probably
needs tweaking.
Tom Eccles [Sun, 21 Feb 2021 11:19:50 +0000 (11:19 +0000)]
bootstrap: don't run linkcheck when crosscompiling
When we cross compile, some things (and their documentation) are built
for the host (e.g. rustc), while others (and their documentation) are built
for the target. This generated documentation will have broken links
between documentation for different platforms e.g. between rustc and
cargo.
Tom Eccles [Sat, 9 Jan 2021 22:54:21 +0000 (22:54 +0000)]
run-make: Specify --target to rustc
Resolves #78911
The target's linker was used but rustc wasn't told to build for that
target (instead defaulting to the host). This led to the host instead of
the target getting tested and to the linker getting inappropriate
arguments.
bors [Sun, 28 Mar 2021 14:16:03 +0000 (14:16 +0000)]
Auto merge of #83582 - jyn514:might-not, r=joshtriplett
may not -> might not
may not -> might not
"may not" has two possible meanings:
1. A command: "You may not stay up past your bedtime."
2. A fact that's only sometimes true: "Some cities may not have bike lanes."
In some cases, the meaning is ambiguous: "Some cars may not have snow
tires." (do the cars *happen* to not have snow tires, or is it
physically impossible for them to have snow tires?)
This changes places where the standard library uses the "description of
fact" meaning to say "might not" instead.
This is just `std::vec` for now - if you think this is a good idea I can
convert the rest of the standard library.
bors [Sun, 28 Mar 2021 08:53:51 +0000 (08:53 +0000)]
Auto merge of #83593 - petrochenkov:nounwrap, r=nagisa
rustc_target: Avoid unwraps when adding linker flags
These `unwrap`s assume that some linker flags were already added by `*_base::opts()` methods, but that's doesn't necessarily remain the case when we are reducing the number of flags hardcoded in targets, as https://github.com/rust-lang/rust/pull/83587 shows.
bors [Sun, 28 Mar 2021 03:51:22 +0000 (03:51 +0000)]
Auto merge of #81354 - SkiFire13:binary-search-assume, r=nagisa
Instruct LLVM that binary_search returns a valid index
This allows removing bound checks when the return value of `binary_search` is used to index into the slice it was call on. I also added a codegen test for this, not sure if it's the right thing to do (I didn't find anything on the dev guide), but it felt so.
Joshua Nelson [Sun, 28 Mar 2021 02:16:17 +0000 (22:16 -0400)]
Address more review comments
- Add back various diagnostic methods on `Session`.
It seems unfortunate to duplicate these in so many places, but in the
meantime, making the API inconsistent between `Session` and `Diagnostic`
also seems unfortunate.
- Add back TyCtxtAt methods
These will hopefully be used in the near future.
- Add back `with_const`, it would need to be added soon after anyway.
- Add back `split()` and `get_mut()`, they're useful.
Joshua Nelson [Tue, 16 Mar 2021 16:57:31 +0000 (12:57 -0400)]
Address review comments
- Add back `HirIdVec`, with a comment that it will soon be used.
- Add back `*_region` functions, with a comment they may soon be used.
- Remove `-Z borrowck_stats` completely. It didn't do anything.
- Remove `make_nop` completely.
- Add back `current_loc`, which is used by an out-of-tree tool.
- Fix style nits
- Remove `AtomicCell` with `cfg(parallel_compiler)` for consistency.
Joshua Nelson [Tue, 16 Mar 2021 05:50:34 +0000 (01:50 -0400)]
Remove (lots of) dead code
Found with https://github.com/est31/warnalyzer.
Dubious changes:
- Is anyone else using rustc_apfloat? I feel weird completely deleting
x87 support.
- Maybe some of the dead code in rustc_data_structures, in case someone
wants to use it in the future?
- Don't change rustc_serialize
I plan to scrap most of the json module in the near future (see
https://github.com/rust-lang/compiler-team/issues/418) and fixing the
tests needed more work than I expected.
TODO: check if any of the comments on the deleted code should be kept.
bors [Sat, 27 Mar 2021 22:19:17 +0000 (22:19 +0000)]
Auto merge of #83103 - petrochenkov:unilex, r=Aaron1011
resolve: Partially unify early and late scope-relative identifier resolution
Reuse `early_resolve_ident_in_lexical_scope` instead of a chunk of code in `resolve_ident_in_lexical_scope` doing the same job.
`early_resolve_ident_in_lexical_scope`/`visit_scopes` had to be slightly extended to be able to 1) start from a specific module instead of the current parent scope and 2) report one deprecation lint.
`early_resolve_ident_in_lexical_scope` still doesn't support walking through "ribs", that part is left in `resolve_ident_in_lexical_scope` (moreover, I'm pretty sure it's buggy, but that's a separate issue, cc https://github.com/rust-lang/rust/issues/52389 at least).
Joshua Nelson [Sat, 27 Mar 2021 19:56:07 +0000 (15:56 -0400)]
may not -> might not
"may not" has two possible meanings:
1. A command: "You may not stay up past your bedtime."
2. A fact that's only sometimes true: "Some cities may not have bike lanes."
In some cases, the meaning is ambiguous: "Some cars may not have snow
tires." (do the cars *happen* to not have snow tires, or is it
physically impossible for them to have snow tires?)
This changes places where the standard library uses the "description of
fact" meaning to say "might not" instead.
This is just `std::vec` for now - if you think this is a good idea I can
convert the rest of the standard library.
Dylan DPC [Sat, 27 Mar 2021 19:37:12 +0000 (20:37 +0100)]
Rollup merge of #83548 - Aaron1011:capture-none-delims, r=petrochenkov
Always preserve `None`-delimited groups in a captured `TokenStream`
Previously, we would silently remove any `None`-delimiters when
capturing a `TokenStream`, 'flattenting' them to their inner tokens.
This was not normally visible, since we usually have
`TokenKind::Interpolated` (which gets converted to a `None`-delimited
group during macro invocation) instead of an actual `None`-delimited
group.
However, there are a couple of cases where this becomes visible to
proc-macros:
1. A cross-crate `macro_rules!` macro has a `None`-delimited group
stored in its body (as a result of being produced by another
`macro_rules!` macro). The cross-crate `macro_rules!` invocation
can then expand to an attribute macro invocation, which needs
to be able to see the `None`-delimited group.
2. A proc-macro can invoke an attribute proc-macro with its re-collected
input. If there are any nonterminals present in the input, they will
get re-collected to `None`-delimited groups, which will then get
captured as part of the attribute macro invocation.
Both of these cases are incredibly obscure, so there hopefully won't be
any breakage. This change will allow more agressive 'flattenting' of
nonterminals in #82608 without losing `None`-delimited groups.
Dylan DPC [Sat, 27 Mar 2021 19:37:09 +0000 (20:37 +0100)]
Rollup merge of #82993 - camelid:source-use-diag, r=jyn514
rustdoc: Use diagnostics for error when including sources
This error probably almost never happens, but we should still use the
diagnostic infrastructure. My guess is that the error was added back
before rustdoc used the rustc diagnostic infrastructure (it was all
`println!` and `eprintln!` back then!) and since it likely rarely occurs
and this code doesn't change that much, no one thought to transition it
to using diagnostics.
Note that the old error was actually a warning (it didn't stop the rest
of doc building). It seems very unlikely that this would fail without
the rest of the doc build failing, so it makes more sense for it to be a
hard error.
The error looks like this:
error: failed to render source code for `src/test/rustdoc/smart-punct.rs`: "bar": foo
--> src/test/rustdoc/smart-punct.rs:3:1
|
3 | / #![crate_name = "foo"]
4 | |
5 | | //! This is the "start" of the 'document'! How'd you know that "it's" ...
6 | | //!
... |
22 | | //! I say "don't smart-punct me -- please!"
23 | | //! ```
| |_______^
I wasn't sure how to trigger the error, so to create that message I
temporarily made rustdoc always emit it. That's also why it says "bar"
and "foo" instead of a real error message.
Note that the span of the diagnostic starts at line 3 because line 1 of
that file is a (non-doc) comment and line 2 is a blank line.
Dylan DPC [Sat, 27 Mar 2021 19:37:07 +0000 (20:37 +0100)]
Rollup merge of #82917 - cuviper:iter-zip, r=m-ou-se
Add function core::iter::zip
This makes it a little easier to `zip` iterators:
```rust
for (x, y) in zip(xs, ys) {}
// vs.
for (x, y) in xs.into_iter().zip(ys) {}
```
You can `zip(&mut xs, &ys)` for the conventional `iter_mut()` and
`iter()`, respectively. This can also support arbitrary nesting, where
it's easier to see the item layout than with arbitrary `zip` chains:
```rust
for ((x, y), z) in zip(zip(xs, ys), zs) {}
for (x, (y, z)) in zip(xs, zip(ys, zs)) {}
// vs.
for ((x, y), z) in xs.into_iter().zip(ys).zip(xz) {}
for (x, (y, z)) in xs.into_iter().zip((ys.into_iter().zip(xz)) {}
```
It may also format more nicely, especially when the first iterator is a
longer chain of methods -- for example:
Dylan DPC [Sat, 27 Mar 2021 19:37:05 +0000 (20:37 +0100)]
Rollup merge of #82525 - RalfJung:unaligned-ref-warn, r=petrochenkov
make unaligned_references future-incompat lint warn-by-default
and also remove the safe_packed_borrows lint that it replaces.
`std::ptr::addr_of!` has hit beta now and will hit stable in a month, so I propose we start fixing https://github.com/rust-lang/rust/issues/27060 for real: creating a reference to a field of a packed struct needs to eventually become a hard error; this PR makes it a warn-by-default future-incompat lint. (The lint already existed, this just raises its default level.) At the same time I removed the corresponding code from unsafety checking; really there's no reason an `unsafe` block should make any difference here.
For references to packed fields outside `unsafe` blocks, this means `unaligned_refereces` replaces the previous `safe_packed_borrows` warning with a link to https://github.com/rust-lang/rust/issues/82523 (and no more talk about unsafe blocks making any difference). So behavior barely changes, the warning is just worded differently. For references to packed fields inside `unsafe` blocks, this PR shows a new future-incompat warning.
Closes https://github.com/rust-lang/rust/issues/46043 because that lint no longer exists.
Dylan DPC [Sat, 27 Mar 2021 19:37:04 +0000 (20:37 +0100)]
Rollup merge of #81351 - lcnr:big-money-big-prices, r=oli-obk
combine: stop eagerly evaluating consts
`super_relate_consts` eagerly evaluates constants which doesn't seem too great.
I now also finally understand why all of the unused substs test passed. The reason being
that we just evaluated the constants in `super_relate_consts` :laughing:
While this change isn't strictly necessary as evaluating consts here doesn't hurt, it still feels a lot cleaner to do it this way
Yuki Okushi [Sat, 27 Mar 2021 16:33:19 +0000 (01:33 +0900)]
Rollup merge of #83560 - m-ou-se:io-chain-debug, r=sfackler
Derive Debug for io::Chain instead of manually implementing it.
This derives Debug for io::Chain instead of manually implementing it.
The manual implementation has the same bounds, so I don't think there's any reason for a manual implementation. The names used in the derive implementation are even nicer (`first`/`second`) than the manual implementation (`t`/`u`), and include the `done_first` field too.
Yuki Okushi [Sat, 27 Mar 2021 16:33:18 +0000 (01:33 +0900)]
Rollup merge of #83559 - m-ou-se:rwlock-guard-debug-fix, r=jackh726
Fix Debug implementation for RwLock{Read,Write}Guard.
This would attempt to print the Debug representation of the lock that the guard has locked, which will try to lock again, fail, and just print `"<locked>"` unhelpfully.
After this change, this just prints the contents of the mutex, like the other smart pointers (and MutexGuard) do.
MutexGuard had this problem too: https://github.com/rust-lang/rust/issues/57702
Yuki Okushi [Sat, 27 Mar 2021 16:33:15 +0000 (01:33 +0900)]
Rollup merge of #83462 - ijackson:exitstatus-message-wording, r=joshtriplett
ExitStatus: print "exit status: {}" rather than "exit code: {}" on unix
Proper Unix terminology is "exit status" (vs "wait status"). "exit
code" is imprecise on Unix and therefore unclear. (As far as I can
tell, "exit code" is correct terminology on Windows.)
This new wording is unfortunately inconsistent with the identifier
names in the Rust stdlib.
It is the identifier names that are wrong, as discussed at length in eg
https://doc.rust-lang.org/nightly/std/process/struct.ExitStatus.html
https://doc.rust-lang.org/nightly/std/os/unix/process/trait.ExitStatusExt.html
Unfortunately for API stability reasons it would be a lot of work, and
a lot of disruption, to change the names in the stdlib (eg to rename
`std::process::ExitStatus` to `std::process::ChildStatus` or
something), but we should fix the message output. Many (probably
most) readers of these messages about exit statuses will be users and
system administrators, not programmers, who won't even know that Rust
has this wrong terminology.
So I think the right thing is to fix the documentation (as I have
already done) and, now, the terminology in the implementation.
This is a user-visible change to the behaviour of all Rust programs
which run Unix subprocesses. Hopefully no-one is matching against the
exit status string, except perhaps in tests.
Yuki Okushi [Sat, 27 Mar 2021 16:33:13 +0000 (01:33 +0900)]
Rollup merge of #83348 - osa1:issue83344, r=jackh726
format macro argument parsing fix
When the character next to `{}` is "shifted" (when mapping a byte index
in the format string to span) we should avoid shifting the span end
index, so first map the index of `}` to span, then bump the span,
instead of first mapping the next byte index to a span (which causes
bumping the end span too much).