Rollup merge of #74774 - oliver-giersch:set_data_ptr, r=dtolnay
adds [*mut|*const] ptr::set_ptr_value
I propose the addition of these two functions to `*mut T` and `*const T`, respectively. The motivation for this is primarily byte-wise pointer arithmetic on (potentially) fat pointers, i.e. for types with a `T: ?Sized` bound. A concrete use-case has been discussed in [this](https://internals.rust-lang.org/t/byte-wise-fat-pointer-arithmetic/12739) thread.
TL;DR: Currently, byte-wise pointer arithmetic with potentially fat pointers in not possible in either stable or nightly Rust without making assumptions about the layout of fat pointers, which is currently still an implementation detail and not formally stabilized. This PR adds one function to `*mut T` and `*const T` each, allowing to circumvent this restriction without exposing any internal implementation details.
One possible alternative would be to add specific byte-wise pointer arithmetic functions to the two pointer types in addition to the already existing count-wise functions. However, I feel this fairly niche use case does not warrant adding a whole set of new functions like `add_bytes`, `offset_bytes`, `wrapping_offset_bytes`, etc. (times two, one for each pointer type) to `libcore`.
Yuki Okushi [Fri, 7 Aug 2020 00:35:24 +0000 (09:35 +0900)]
Rollup merge of #75210 - nnethercote:change-type-of-available_cgus, r=ecstatic-morse
Change the type of `AssertModuleSource::available_cgus`.
It's currently a `BTreeSet<Symbol>`, which is a strange type. The
`BTreeSet` suggests that element order is important, but `Symbol` is a
type whose ordering isn't useful to humans. The ordering of the
collection only manifests in an obscure error message ("no module named
`...`") that doesn't appear in any tests.
This commit changes the `Symbol` to a `String`, which is more
typical.
Change the type of `AssertModuleSource::available_cgus`.
It's currently a `BTreeSet<Symbol>`, which is a strange type. The
`BTreeSet` suggests that element order is important, but `Symbol` is a
type whose ordering isn't useful to humans. The ordering of the
collection only manifests in an obscure error message ("no module named
`...`") that doesn't appear in any tests.
This commit changes the `Symbol` to a `String`, which is more
typical.
bors [Thu, 6 Aug 2020 12:12:59 +0000 (12:12 +0000)]
Auto merge of #74889 - JohnTitor:hrtb-tests, r=nikomatsakis
Add HRTB-related regression test
Closes #59311 and cc #71546
This closes the former but the test is taken from https://github.com/rust-lang/rust/issues/71546#issuecomment-620638437 since it seems they have the same cause and it's simplified.
bors [Thu, 6 Aug 2020 03:23:57 +0000 (03:23 +0000)]
Auto merge of #75008 - eddyb:rmeta-indexed-trait-impls, r=nikomatsakis
rustc_metadata: track the simplified Self type for every trait impl.
For the `traits_impls_of` query, we index the impls by `fast_reject::SimplifiedType` (a "shallow type"), which allows some simple cases like `impl Trait<..> for Foo<..>` to be efficiently iterated over, by e.g. `for_each_relevant_impl`.
This PR encodes the `fast_reject::SimplifiedType` cross-crate to avoid needing to deserialize the `Self` type of every `impl` in order to simplify it - the simplification itself should be cheap, but the deserialization is less so.
We could go further from here and make loading the list of impls lazy, for a given simplified `Self` type, but that would have more complicated implications for performance, and this PR doesn't do anything in that regard.
bors [Wed, 5 Aug 2020 17:58:55 +0000 (17:58 +0000)]
Auto merge of #75005 - adamreichold:limit-vector-count, r=Amanieu
Limit I/O vector count on Unix
Unix systems enforce limits on the vector count when performing vectored I/O via the readv and writev system calls and return EINVAL when these limits are exceeded. This changes the standard library to handle those limits as short reads and writes to avoid forcing its users to query these limits using platform specific mechanisms.
bors [Wed, 5 Aug 2020 16:08:53 +0000 (16:08 +0000)]
Auto merge of #75194 - Aaron1011:feature/macro-backtrace-numbers, r=eddyb
Show backtrace numbers in backtrace whenever more than one is involved
Previously, we only displayed 'frame' numbers in a macro backtrace when more
than two frames were involved. This commit should help make backtrace
more readable, since these kinds of messages can quickly get confusing.
Aaron Hill [Wed, 5 Aug 2020 15:02:25 +0000 (11:02 -0400)]
Show backtrace numbers in backtrace whenever more than one is involved
Previously, we only displayed 'frame' numbers in a macro backtrace when more
than two frames were involved. This commit should help make backtrace
more readable, since these kinds of messages can quickly get confusing.
Adam Reichold [Sat, 1 Aug 2020 14:06:00 +0000 (16:06 +0200)]
Rely only on POSIX semantics for I/O vector count
All #[cfg(unix)] platforms follow the POSIX standard and define _SC_IOV_MAX so
that we rely purely on POSIX semantics to determine the limits on I/O vector
count.
Adam Reichold [Sat, 1 Aug 2020 12:29:42 +0000 (14:29 +0200)]
Memoize the I/O vector count limit
Keep the I/O vector count limit in a `SyncOnceCell` to avoid the overhead of
repeatedly calling `sysconf` as these limits are guaranteed to not change during
the lifetime of a process by POSIX.
Adam Reichold [Sat, 1 Aug 2020 12:18:11 +0000 (14:18 +0200)]
Query maximum vector count on Linux and macOS
Both Linux and MacOS enforce limits on the vector count when performing vectored
I/O via the readv and writev system calls and return EINVAL when these limits
are exceeded. This changes the standard library to handle those limits as short
reads and writes to avoid forcing its users to query these limits using
platform specific mechanisms.
bors [Wed, 5 Aug 2020 06:55:42 +0000 (06:55 +0000)]
Auto merge of #75155 - davidtwco:polymorphization-incr-comp-optimisations, r=lcnr
polymorphization: various improvements
This PR includes a handful of polymorphisation-related changes:
- @Mark-Simulacrum's suggestions [from this comment](https://github.com/rust-lang/rust/pull/74633#issuecomment-668684433):
- Use a `FiniteBitSet<u32>` over a `FiniteBitSet<u64>` as most functions won't have 64 generic parameters.
- Don't encode polymorphisation results in metadata when every parameter is used (in this case, just invoking polymorphisation will probably be quicker).
- @lcnr's suggestion [from this comment](https://github.com/rust-lang/rust/pull/74717#discussion_r463690015).
- Add an debug assertion in `ensure_monomorphic_enough` to make sure that polymorphisation did what we expect.
bors [Wed, 5 Aug 2020 05:08:19 +0000 (05:08 +0000)]
Auto merge of #75037 - richkadel:llvm-coverage-map-gen-5.2, r=wesleywiser
Completes support for coverage in external crates
Follow-up to #74959 :
The prior PR corrected for errors encountered when trying to generate
the coverage map on source code inlined from external crates (including
macros and generics) by avoiding adding external DefIds to the coverage
map.
This made it possible to generate a coverage report including external
crates, but the external crate coverage was incomplete (did not include
coverage for the DefIds that were eliminated.
The root issue was that the coverage map was converting Span locations
to source file and locations, using the SourceMap for the current crate,
and this would not work for spans from external crates (compliled with a
different SourceMap).
The solution was to convert the Spans to filename and location during
MIR generation instead, so precompiled external crates would already
have the correct source code locations embedded in their MIR, when
imported into another crate.
bors [Wed, 5 Aug 2020 03:04:21 +0000 (03:04 +0000)]
Auto merge of #75174 - JohnTitor:rollup-z9djftk, r=JohnTitor
Rollup of 5 pull requests
Successful merges:
- #75139 (Remove log alias from librustdoc)
- #75140 (Clean up E0745)
- #75149 (Correct a typo in interpret/memory.rs)
- #75152 (Replace `Memoryblock` with `NonNull<[u8]>`)
- #75168 (Update books)
Lzu Tao [Wed, 5 Aug 2020 02:49:26 +0000 (02:49 +0000)]
Use u32::from_ne_bytes to fix a FIXME
Co-authored-by: Weiyi Wang <wwylele@gmail.com> Co-authored-by: Adam Reichold <adam.reichold@t-online.de> Co-authored-by: Josh Stone <cuviper@gmail.com> Co-authored-by: Scott McMurray <scottmcm@users.noreply.github.com> Co-authored-by: tmiasko <tomasz.miasko@gmail.com>
Yuki Okushi [Wed, 5 Aug 2020 02:40:11 +0000 (11:40 +0900)]
Rollup merge of #75168 - ehuss:update-books, r=ehuss
Update books
## reference
7 commits in b329ce37424874ad4db94f829a55807c6e21d2cb..c9b2736a059469043177e1e4ed41a55d7c63ac28
2020-07-20 08:54:08 -0700 to 2020-08-03 03:34:03 -0700
- Fix documented build output path. (rust-lang-nursery/reference#870)
- Update token usage table. (rust-lang-nursery/reference#868)
- Allow trait inner attributes (rust-lang-nursery/reference#864)
- patterns.md - add word "underscore" to _ paragraph (rust-lang-nursery/reference#865)
- Drive-by mention unsafe fn closure coercion (rust-lang-nursery/reference#802)
- grammar: Change "For awhile" to "For a while" (rust-lang-nursery/reference#857)
- Added Unpin to list of Auto Traits (rust-lang-nursery/reference#854)
## book
7 commits in a914f2c7e5cdb771fa465de142381a51c53b580e..363293c1c5ce9e84ea3935a5e29ce8624801208a
2020-07-21 09:20:05 -0500 to 2020-08-03 15:56:30 -0500
- replace commas with m-dashes to improve readability of chapter 4.1 (rust-lang/book#2419)
- Update TOML link to official website (rust-lang/book#2411)
- Add github repo link (rust-lang/book#2265)
- Remove the version number entirely so we can stop updating it
- Add link to the `Vec<T>` API documentation (rust-lang/book#2249)
- link to stdlib atomic docs (rust-lang/book#2361)
- mdbook version used is now 0.4.x (rust-lang/book#2410)
`run()` returns `Result<(), String>`. But on failure it always returns
an empty string, and then `wrap_return()` treats an empty string
specially, by not reporting the error.
It turns out we already have the `ErrorReported` type for this sort of
behaviour. This commit changes `run()` to use it.
Avoid an unnecessary thread creation at rustdoc startup.
rustdoc's `main()` immediately spawns a thread, M, with a large stack
(16MiB or 32MiB) on which it runs `main_args()`. `main_args()` does a
small amount of options processing and then calls
`setup_callbacks_and_run_in_default_thread_pool_with_globals()`, which
spawns it own thread, and M is not used further.
So, thread M seems unnecessary. However, it does serve a purpose: if the
options processing in `main_args()` panics, that panic is caught when M
is joined. So M can't simply be removed.
However, `main_options()`, which is called by `main_args()`, has a
`catch_fatal_errors()` call within it. We can move that call to `main()`
and change it to the very similar `catch_with_exit_code()`. With that in
place, M can be removed, and panics from options processing will still
be caught appropriately.
Even better, this makes rustdoc's `main()` match rustc's `main()`, which
also uses `catch_with_exit_code()`.
(Also note that the use of a 16MiB/32MiB stack was eliminated from rustc
in #55617.)
David Wood [Tue, 4 Aug 2020 17:16:39 +0000 (18:16 +0100)]
metadata: skip empty polymorphization bitset
This commit skips encoding empty polymorphization results - while
polymorphization is disabled, this should be every polymorphization
result; but when polymorphization is re-enabled, this would help with
non-generic functions and those which do use all their parameters (most
functions).
Rich Kadel [Sun, 2 Aug 2020 03:03:59 +0000 (20:03 -0700)]
Completes support for coverage in external crates
The prior PR corrected for errors encountered when trying to generate
the coverage map on source code inlined from external crates (including
macros and generics) by avoiding adding external DefIds to the coverage
map.
This made it possible to generate a coverage report including external
crates, but the external crate coverage was incomplete (did not include
coverage for the DefIds that were eliminated.
The root issue was that the coverage map was converting Span locations
to source file and locations, using the SourceMap for the current crate,
and this would not work for spans from external crates (compliled with a
different SourceMap).
The solution was to convert the Spans to filename and location during
MIR generation instead, so precompiled external crates would already
have the correct source code locations embedded in their MIR, when
imported into another crate.
David Wood [Tue, 4 Aug 2020 17:11:57 +0000 (18:11 +0100)]
mir: use `FiniteBitSet<u32>` in polymorphization
This commit changes polymorphization to return a `FiniteBitSet<u32>`
rather than a `FiniteBitSet<u64>` because most functions do not use
anywhere near sixty-four generic parameters so keeping a `u64` around is
unnecessary in most cases.
bors [Tue, 4 Aug 2020 17:07:40 +0000 (17:07 +0000)]
Auto merge of #75133 - nnethercote:rm-SubstFolder-fields, r=matthewjasper
Remove two fields from `SubstFolder`.
They're only used in error messages printed if there's an internal
compiler error, and the cost of maintaining them is high enough to show
up in profiles.
bors [Tue, 4 Aug 2020 09:18:22 +0000 (09:18 +0000)]
Auto merge of #75095 - pietroalbini:fallible-fast-fail, r=Mark-Simulacrum
ci: disable fast-fail on auto-fallible
The purpose of the auto-fallible job is to run builders that are likely to fail on CI without gating on them. Having fast-fail enabled there kinda defeats the purpose, as if one of them fails we can't monitor the outcome of the other ones.
This was prompted by the aarch64-gnu builder consistently failing due to a broken test, preventing us from seeing if the macOS spurious failure is fixed.
Pietro Albini [Mon, 3 Aug 2020 08:32:47 +0000 (10:32 +0200)]
ci: disable fail-fast on auto-fallible
The purpose of the auto-fallible job is to run builders that are likely
to fail on CI without gating on them. Having fail-fast enabled there
kinda defeats the purpose, as if one of them fails we can't monitor the
outcome of the other ones.
This was prompted by the aarch64-gnu builder consistently failing due to
a broken test, preventing us from seeing if the macOS spurious failure
is fixed.
They're only used in error messages printed if there's an internal
compiler error, and the cost of maintaining them is high enough to show
up in profiles.
bors [Tue, 4 Aug 2020 05:37:44 +0000 (05:37 +0000)]
Auto merge of #75111 - mati865:use-lld-option, r=Mark-Simulacrum
Make rust.use-lld config option work with non MSVC targets
Builds fine and passes tests on Linux.
Not overriding `use-lld` by `linker` makes sense on those platforms since very old GCC versions don't understand `-fuse-ld=lld`. This allows pointing to newer GCC or Clang that will know how to call LLD.
bors [Tue, 4 Aug 2020 01:48:32 +0000 (01:48 +0000)]
Auto merge of #75126 - JohnTitor:rollup-aejluzx, r=JohnTitor
Rollup of 8 pull requests
Successful merges:
- #74759 (add `unsigned_abs` to signed integers)
- #75043 (rustc_ast: `(Nested)MetaItem::check_name` -> `has_name`)
- #75056 (Lint path statements to suggest using drop when the type needs drop)
- #75081 (Fix logging for rustdoc)
- #75083 (Do not trigger `unused_braces` for `while let`)
- #75084 (Stabilize Ident::new_raw)
- #75103 (Disable building rust-analyzer on riscv64)
- #75106 (Enable docs on in the x86_64-unknown-linux-musl manifest)
Yuki Okushi [Tue, 4 Aug 2020 00:27:10 +0000 (09:27 +0900)]
Rollup merge of #75106 - etherealist:docs_manifest, r=Mark-Simulacrum
Enable docs on in the x86_64-unknown-linux-musl manifest
Add the rust-docs component to toolchain x86_64-unknown-linux-musl, which allows people using rustup on their musl-based linux distribution to download the rust-docs.
Generating and uploading the docs was enabled in b5d143b (#74871).
In #75102 @Mark-Simulacrum found that we are uploading the docs, but the correct manifest is missing.
* The relevant call to build-manifest seems to be [in bootstrap](https://github.com/rust-lang/rust/blob/c058a8b8dc5dea0ed9b33e14da9e317e2749fcd7/src/bootstrap/dist.rs#L2334)
* The manifest is then used in [promote-release crontab](https://github.com/rust-lang/rust-central-station/blob/master/crontab)
Yuki Okushi [Tue, 4 Aug 2020 00:27:08 +0000 (09:27 +0900)]
Rollup merge of #75103 - Mark-Simulacrum:no-ra-for-riscv64, r=matklad
Disable building rust-analyzer on riscv64
riscv64 has an LLVM bug that makes rust-analyzer not build. Should permit future rust-analyzer ups (e.g., https://github.com/rust-lang/rust/pull/74813) to land.
bors [Mon, 3 Aug 2020 23:57:50 +0000 (23:57 +0000)]
Auto merge of #74695 - alexcrichton:more-wasm-float-cast-fixes, r=nagisa
rustc: Improving safe wasm float->int casts
This commit improves code generation for WebAssembly targets when
translating floating to integer casts. This improvement is only relevant
when the `nontrapping-fptoint` feature is not enabled, but the feature
is not enabled by default right now. Additionally this improvement only
affects safe casts since unchecked casts were improved in #74659.
Some more background for this issue is present on #73591, but the
general gist of the issue is that in LLVM the `fptosi` and `fptoui`
instructions are defined to return an `undef` value if they execute on
out-of-bounds values; they notably do not trap. To implement these
instructions for WebAssembly the LLVM backend must therefore generate
quite a few instructions before executing `i32.trunc_f32_s` (for
example) because this WebAssembly instruction traps on out-of-bounds
values. This codegen into wasm instructions happens very late in the
code generator, so what ends up happening is that rustc inserts its own
codegen to implement Rust's saturating semantics, and then LLVM also
inserts its own codegen to make sure that the `fptosi` instruction
doesn't trap. Overall this means that a function like this:
#[no_mangle]
pub unsafe extern "C" fn cast(x: f64) -> u32 {
x as u32
}
This PR improves the situation by updating the code generation for
float-to-int conversions in rustc, specifically only for WebAssembly
targets and only for some situations (float-to-u8 still has not great
codegen). The fix here is to use basic blocks and control flow to avoid
speculatively executing `fptosi`, and instead LLVM's raw intrinsic for
the WebAssembly instruction is used instead. This effectively extends
the support added in #74659 to checked casts. After this commit the
codegen for the above Rust function looks like:
So we're relatively close to the original codegen, although it's
slightly different because the semantics of the function changed where
we're emulating the `i32.trunc_sat_f32_s` instruction rather than always
replacing out-of-bounds values with zero.
There is still work that could be done to improve casts such as `f32` to
`u8`. That form of cast still uses the `fptosi` instruction which
generates lots of branch-y code. This seems less important to tackle now
though. In the meantime this should take care of most use cases of
floating-point conversion and as a result I'm going to speculate that
this...