Ensure derive(PartialOrd) is no longer accidentally exponential
Previously, two comparison operations would be generated for each field, each of which could delegate to another derived PartialOrd. Now we use ordering and optional chaining to ensure each pair of fields is only compared once, addressing https://github.com/rust-lang/rust/issues/49650#issuecomment-379467572.
Closes#49505.
r? @Manishearth (sorry for changing it again so soon!)
Close#50755
typeck: Save the index of private fields
Save the index of all fields regardless of their visibility. Problems
could occur later when attempting to index fields in error recovery if
they are not inserted.
Fixes: #50493
It was introduced in #50240 to avoid an allocation when creating a new
BTreeMap, which gave some speed-ups. But then #50352 made that the
default behaviour for BTreeMap, so LazyBTreeMap is no longer necessary.
Previously, every `open64` was accompanied by a `ioctl(…, FIOCLEX)`,
because some old Linux version would ignore the `O_CLOEXEC` flag we pass
to the `open64` function.
Now, we check whether the `CLOEXEC` flag is set on the first file we
open – if it is, we won't do extra syscalls for every opened file. If it
is not set, we fall back to the old behavior of unconditionally calling
`ioctl(…, FIOCLEX)` on newly opened files.
On old Linuxes, this amounts to one extra syscall per process, namely
the `fcntl(…, F_GETFD)` call to check the `CLOEXEC` flag.
On new Linuxes, this reduces the number of syscalls per opened file by
one, except for the first file, where it does the same number of
syscalls as before (`fcntl(…, F_GETFD)` to check the flag instead of
`ioctl(…, FIOCLEX)` to set it).
update libcompiler_builtins
let's OpenBSD to use libcompiler_rt.a from system library. it unbreaks
the build from source on OpenBSD.
see https://github.com/rust-lang-nursery/compiler-builtins/pull/241 for related PR
note this PR brings some other changes (on `floatdisf`/`floatundisf`) with compiler-builtins update.
r? @alexcrichton
Fix self referential impl Trait substitutions
A high impact bug because a lot of common traits use a `Self` substitution by default. Should be backported to beta.
There was a check for this which wasn't catching all cases, it was made more robust.
Fixes#49376Fixes#50626
r? @petrochenkov
Save the index of all fields regardless of their visibility. Problems
could occur later when attempting to index fields in error recovery if
they are not inserted.
This PR improves the span of eager resolution type errors referring to indexing and field access to use the base span rather than the whole expression.
Also a note "Type must be known at this point." is added to where we at some point in the past emitted the "type must be known at this context" error, so that early failures can be differentiated and will hopefully be less surprising.
Fixes#50692 (or at least does the best we can for the moment)
r? @estebank
Rollup of 8 pull requests
Successful merges:
- #50624 (fs::write: Add example writing a &str)
- #50634 (Do not silently truncate offsets for `read_at`/`write_at` on emscripten)
- #50644 (AppVeyor: Read back trace from crash dump on failure.)
- #50661 (Ignore non .rs files for tidy libcoretest)
- #50663 (rustc: Allow an edition's feature on that edition)
- #50667 (rustc: Only suggest deleting `extern crate` if it works)
- #50670 (rustc: Include semicolon when removing `extern crate`)
- #50678 (Update openbsd targets)
Failed merges:
Update openbsd targets
- add a new target `aarch64-unknown-openbsd`
- update `i686-unknown-openbsd` to use lld with clang, in order to correctly link binaries with `i128`
rustc: Include semicolon when removing `extern crate`
Currently the lint for removing `extern crate` suggests removing `extern crate`
most of the time, but the rest of the time it suggest replacing it with `use
crate_name`. Unfortunately though when spliced into the original code you're
replacing
extern crate foo;
with
use foo
which is syntactically invalid! This commit ensure that the trailing semicolon
is included in rustc's suggestion to ensure that the code continues to compile
afterwards.
rustc: Only suggest deleting `extern crate` if it works
This commit updates one of the edition lints to only suggest deleting `extern
crate` if it actually works. Otherwise this can yield some confusing behavior
with rustfix specifically where if you accidentally deny the `rust_2018_idioms`
lint in the 2015 edition it's suggesting features that don't work!
rustc: Allow an edition's feature on that edition
This commit fixes a hard error where the `#![feature(rust_2018_preview)]`
feature was forbidden to be mentioned when the `--edition 2018` flag was passed.
This instead silently accepts that feature gate despite it not being necessary.
It's intended that this will help ease the transition into the 2018 edition as
users will, for the time being, start off with the `rust_2018_preview` feature
and no longer immediately need to remove it.
Closes#50662
Ignore non .rs files for tidy libcoretest
Previously, any file would be read, which is both unnecessary, and causes issues if irrelevant non-Unicode files were read (e.g. `.DS_STORE`).
