This is a follow-up from #91645, regarding [some remarks I made](https://rust-lang.zulipchat.com/#narrow/stream/187312-wg-async-foundations/topic/join!/near/264293660).
Mainly:
- it hides the recursive munching through a private `macro`, to avoid leaking such details (a corollary is getting rid of the need to use `@` to disambiguate);
- it uses a `match` binding, _outside_ the `async move` block, to better match the semantics from function-like syntax;
- it pre-pins the future before calling into `poll_fn`, since `poll_fn`, alone, cannot guarantee that its capture does not move;
- it uses `.ready()?` since it's such a neat pattern;
- it renames `Took` to `Taken` for consistency with `Done`.
replace vec::Drain drop loops with drop_in_place
The `Drain::drop` implementation came up in https://github.com/rust-lang/rust/pull/82185#issuecomment-789584796 as potentially interfering with other optimization work due its widespread use somewhere in `println!`
`@rustbot` label T-libs-impl
Implement most of RFC 2930, providing the ReadBuf abstraction
This replaces the `Initializer` abstraction for permitting reading into uninitialized buffers, closing #42788.
This leaves several APIs described in the RFC out of scope for the initial implementation:
* read_buf_vectored
* `ReadBufs`
Closes#42788, by removing the relevant APIs.
Rollup of 6 pull requests
Successful merges:
- #87599 (Implement concat_bytes!)
- #89999 (Update std::env::temp_dir to use GetTempPath2 on Windows when available.)
- #90796 (Remove the reg_thumb register class for asm! on ARM)
- #91042 (Use Vec extend instead of repeated pushes on several places)
- #91634 (Do not attempt to suggest help for overly malformed struct/function call)
- #91685 (Install llvm tools to sysroot when assembling local toolchain)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Install llvm tools to sysroot when assembling local toolchain
Some projects (e.g. the `bootimage` crate) may require the
user to install the `llvm-tools-preview` rustup component.
However, this cannot be easily done with a locally built toolchain.
To allow a local toolchain to be used a drop-in replacement for
a normal rustup toolchain in more cases, this PR copies the built
LLVM tools to the sysoot. From the perspective a tool looking
at the sysroot, this is equivalent to installing `llvm-tools-preview`.
Use Vec extend instead of repeated pushes on several places
Inspired by https://github.com/rust-lang/rust/pull/90813, I tried to use a simple regex (`for .*in.*\{\n.*push\(.*\);\n\s+}`) to search for more places that would use `Vec::push` in a loop and replace them with `Vec::extend`.
These probably won't have as much perf. impact as the original PR (if any), but it would probably be better to do a perf run to see if there are not any regressions.
Remove the reg_thumb register class for asm! on ARM
Also restricts r8-r14 from being used on Thumb1 targets as per #90736.
cc ``@Lokathor``
r? ``@joshtriplett``
Update std::env::temp_dir to use GetTempPath2 on Windows when available.
As a security measure, Windows 11 introduces a new temporary directory API, GetTempPath2.
When the calling process is running as SYSTEM, a separate temporary directory
will be returned inaccessible to non-SYSTEM processes. For non-SYSTEM processes
the behavior will be the same as before.
This can help mitigate against attacks such as this one:
https://medium.com/csis-techblog/cve-2020-1088-yet-another-arbitrary-delete-eop-a00b97d8c3e2
Compatibility risk: Software which relies on temporary files to communicate between SYSTEM and non-SYSTEM
processes may be affected by this change. In many cases, such patterns may be vulnerable to the very
attacks the new API was introduced to harden against.
I'm unclear on the Rust project's tolerance for such change-of-behavior in the standard library. If anything,
this PR is meant to raise awareness of the issue and hopefully start the conversation.
How tested: Taking the example code from the documentation and running it through psexec (from SysInternals) on
Win10 and Win11.
On Win10:
C:\test>psexec -s C:\test\main.exe
<...>
Temporary directory: C:\WINDOWS\TEMP\
On Win11:
C:\test>psexec -s C:\test\main.exe
<...>
Temporary directory: C:\Windows\SystemTemp\
Implement concat_bytes!
This implements the unstable `concat_bytes!` macro, which has tracking issue #87555. It can be used like:
```rust
#![feature(concat_bytes)]
fn main() {
assert_eq!(concat_bytes!(), &[]);
assert_eq!(concat_bytes!(b'A', b"BC", [68, b'E', 70]), b"ABCDEF");
}
```
If strings or characters are used where byte strings or byte characters are required, it suggests adding a `b` prefix. If a number is used outside of an array it suggests arrayifying it. If a boolean is used it suggests replacing it with the numeric value of that number. Doubly nested arrays of bytes are disallowed.
Use Vec extend instead of repeated pushes on several places
Inspired by https://github.com/rust-lang/rust/pull/90813, I tried to use a simple regex (`for .*in.*\{\n.*push\(.*\);\n\s+}`) to search for more places that would use `Vec::push` in a loop and replace them with `Vec::extend`.
These probably won't have as much perf. impact as the original PR (if any), but it would probably be better to do a perf run to see if there are not any regressions.
Rollup of 5 pull requests
Successful merges:
- #91245 (suggest casting between i/u32 and char)
- #91337 (Add a suggestion if `macro_rules` is misspelled)
- #91534 (Make rustdoc headings black, and markdown blue)
- #91637 (Add test for packed drops in generators)
- #91667 (Fix indent of itemTypes in search.js)
Failed merges:
- #91568 (Pretty print break and continue without redundant space)
r? `@ghost`
`@rustbot` modify labels: rollup
Some projects (e.g. the `bootimage` crate) may require the
user to install the `llvm-tools-preview` rustup component.
However, this cannot be easily done with a locally built toolchain.
To allow a local toolchain to be used a drop-in replacement for
a normal rustup toolchain in more cases, this PR copies the built
LLVM tools to the sysoot. From the perspective a tool looking
at the sysroot, this is equivalent to installing `llvm-tools-preview`.
suggest casting between i/u32 and char
As discussed in https://github.com/rust-lang/rust/issues/91063 , this adds a suggestion for converting between i32/u32 <-> char with `as`, and a short explanation for why this is safe
Rollup of 7 pull requests
Successful merges:
- #90709 (Only shown relevant type params in E0283 label)
- #91551 (Allow for failure of subst_normalize_erasing_regions in const_eval)
- #91570 (Evaluate inline const pat early and report error if too generic)
- #91571 (Remove unneeded access to pretty printer's `s` field in favor of deref)
- #91610 (Link to rustdoc_json_types docs instead of rustdoc-json RFC)
- #91619 (Update cargo)
- #91630 (Add missing whitespace before disabled HTML attribute)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Update cargo
8 commits in 294967c53f0c70d598fc54ca189313c86c576ea7..40dc281755137ee804bc9b3b08e782773b726e44
2021-11-29 19:04:22 +0000 to 2021-12-06 21:54:44 +0000
- Unify the description of quiet flag (rust-lang/cargo#10168)
- Stabilize future-incompat-report (rust-lang/cargo#10165)
- Support abbreviating `--release` as `-r` (rust-lang/cargo#10133)
- doc: nudge towards simple version requirements (rust-lang/cargo#10158)
- Upgrade clap to 2.34.0 (rust-lang/cargo#10164)
- Treat EOPNOTSUPP the same as ENOTSUP when ignoring failed flock calls. (rust-lang/cargo#10157)
- Add note about RUSTFLAGS removal from build scripts. (rust-lang/cargo#10141)
- Make clippy happy (rust-lang/cargo#10139)
Link to rustdoc_json_types docs instead of rustdoc-json RFC
The JSON format has had [many changes](https://github.com/rust-lang/rust/commits/master/src/rustdoc-json-types) since the RFC, so the rustdoc output is the only up to date reference
```@rustdoc``` modify labels: +A-rustdoc-json +A-docs
Remove unneeded access to pretty printer's `s` field in favor of deref
I found it taxing in some of my recent PRs touching the pretty printer to maintain consistency with the surrounding code, since the current code is all over the place about whether it uses `self.s.…()` or `self.…()` for invoking methods of `rustc_ast_pretty::pp::Printer`.
This PR standardizes on `self.…()` — relying on the `Deref` and `DerefMut` impls introduced by [#62532](cab453250a).
Allow for failure of subst_normalize_erasing_regions in const_eval
Fixes https://github.com/rust-lang/rust/issues/72845
Using associated types that cannot be normalized previously resulted in an ICE. We now allow for normalization failure and return a "TooGeneric" error in that case.
r? ```@RalfJung``` maybe?
Only shown relevant type params in E0283 label
When we point at a binding to suggest giving it a type, erase all the
type for ADTs that have been resolved, leaving only the ones that could
not be inferred. For small shallow types this is not a problem, but for
big nested types with lots of params, this can otherwise cause a lot of
unnecessary visual output.
Use object crate for .rustc metadata generation
We already use the object crate for generating uncompressed .rmeta
metadata object files. This switches the generation of compressed
.rustc object files to use the object crate as well. These have
slightly different requirements in that .rmeta should be completely
excluded from any final compilation artifacts, while .rustc should
be part of shared objects, but not loaded into memory.
The primary motivation for this change is #90326: In LLVM 14, the
current way of setting section flags (and in particular, preventing
the setting of SHF_ALLOC) will no longer work. There are other ways
we could work around this, but switching to the object crate seems
like the most elegant, as we already use it for .rmeta, and as it
makes this independent of the codegen backend. In particular, we
don't need separate handling in codegen_llvm and codegen_gcc.
codegen_cranelift should be able to reuse the implementation as
well, though I have omitted that here, as it is not based on
codegen_ssa.
This change mostly extracts the existing code for .rmeta handling
to allow using it for .rustc as well, and adjusts the codegen
infrastructure to handle the metadata object file separately: We
no longer create a backend-specific module for it, and directly
produce the compiled module instead.
This does not `fix` #90326 by itself yet, as .llvmbc will need to be
handled separately.
r? `@nagisa`
Rollup of 7 pull requests
Successful merges:
- #83744 (Deprecate crate_type and crate_name nested inside #![cfg_attr])
- #90550 (Update certificates in some Ubuntu 16 images.)
- #91272 (Print a suggestion when comparing references to primitive types in `const fn`)
- #91467 (Emphasise that an OsStr[ing] is not necessarily a platform string)
- #91531 (Do not add `;` to expected tokens list when it's wrong)
- #91577 (Address some FIXMEs left over from #91475)
- #91638 (Remove `in_band_lifetimes` from `rustc_mir_transform`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove `in_band_lifetimes` from `rustc_mir_transform`
Like #91580, this was inspired by the conversation in #44524 about possibly removing the feature from the compiler. This crate is a heavy `'tcx` user, so is a nice case study.
r? ``@petrochenkov``
Three interesting ones:
This one had the `'tcx` declared on the function, despite the trait taking a `'tcx`:
```diff
-impl Visitor<'_> for UsedLocals {
+impl<'tcx> Visitor<'tcx> for UsedLocals {
fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) {
```
This one use in-band for one, and underscore for the other:
```diff
-pub fn remove_dead_blocks(tcx: TyCtxt<'tcx>, body: &mut Body<'_>) {
+pub fn remove_dead_blocks<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
```
A spurious name, since there's no single-use-lifetime warning:
```diff
-pub fn run_passes(tcx: TyCtxt<'tcx>, body: &'mir mut Body<'tcx>, passes: &[&dyn MirPass<'tcx>]) {
+pub fn run_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>, passes: &[&dyn MirPass<'tcx>]) {
```
Address some FIXMEs left over from #91475
This shouldn't change behavior, only clarify what we're currently doing. I filed #91576 to see if the treatment of generator drop shims is intentional.
cc #91475
Do not add `;` to expected tokens list when it's wrong
There's a few spots where semicolons are checked for to do error recovery, and should not be suggested (or checked for other stuff).
Fixes#87647
Emphasise that an OsStr[ing] is not necessarily a platform string
Fixes#53261
Since that issue was filed, #56141 added a further clarification to the `OsString` docs. However the ffi docs may still leave the impression that an `OsStr` is in the platform native form. This PR aims to further emphasise that an `OsStr` is not necessarily a platform string.
Update certificates in some Ubuntu 16 images.
These images use crosstool-ng, which needs to download various things off the internet. The certificate for `www.kernel.org` no longer works with the ca-certificates in Ubuntu 16. This resolves the issue by grabbing from a newer image a certificate bundle from https://curl.se/ca/cacert.pem, which is usually somewhat up to date.
Deprecate crate_type and crate_name nested inside #![cfg_attr]
This implements the proposal in https://github.com/rust-lang/rust/pull/83676#issuecomment-811213956, with a future compatibility lint imposed on usage of crate_type/crate_name inside cfg's.
This is a compromise between removing `#![crate_type]` and `#![crate_name]` completely and keeping them as a whole, which requires somewhat of a hack in rustc and is impossible to support by gcc-rust. By only removing `#![crate_type]` and `#![crate_name]` nested inside `#![cfg_attr]` it becomes possible to parse them before a big chunk of the compiler has started.
Replaces https://github.com/rust-lang/rust/pull/83676
```rust
#![crate_type = "lib"] // remains working
#![cfg_attr(foo, crate_type = "bin")] // will stop working
```
# Rationale
As it currently is it is possible to try to access the stable crate id before it is actually set, which will panic. The fact that the Session contains mutable state beyond debugging things also doesn't completely sit well with me. Especially once parallel rustc becomes the default.
I think there is currently also a cyclic dependency where you need to set the stable crate id to be able to load crates, but you need to load crates to expand proc macro attributes that may define #![crate_name] or #![crate_type]. Currently crate level proc macro attributes are unstable or completely unsupported (can't remember which), so this is not a problem, but it may become an issue in the future.
Finally if we want to add incremental compilation to macro expansion or even parsing, we need the StableCrateId to be created together with the Session or even earlier as incremental compilation determines the incremental compilation session dir based on the StableCrateId.
