Update documentation to use `from()` to initialize `HashMap`s and `BTreeMap`s
As of Rust 1.56, `HashMap` and `BTreeMap` both have associated `from()` functions. I think using these in the documentation cleans things up a bit. It allows us to remove some of the `mut`s and avoids the Initialize-Then-Modify anti-pattern.
code-cov: generate dead functions with private/default linkage
As discovered in #85461, the MSVC linker treats weak symbols slightly
differently than unix-y linkers do. This causes link.exe to fail with
LNK1227 "conflicting weak extern definition" where as other targets are
able to link successfully.
This changes the dead functions from being generated as weak/hidden to
private/default which, as the LLVM reference says:
> Global values with “private” linkage are only directly accessible by
objects in the current module. In particular, linking code into a module
with a private global value may cause the private to be renamed as
necessary to avoid collisions. Because the symbol is private to the
module, all references can be updated. This doesn’t show up in any
symbol table in the object file.
This fixes the conflicting weak symbols but doesn't address the reason
*why* we have conflicting symbols for these dead functions. The test
cases added in this commit contain a minimal repro of the fundamental
issue which is that the logic used to decide what dead code functions
should be codegen'd in the current CGU doesn't take into account that
functions can be duplicated across multiple CGUs (for instance, in the
case of `#[inline(always)]` functions).
Fixing that is likely to be a more complex change (see
https://github.com/rust-lang/rust/issues/85461#issuecomment-985005805).
Fixes#85461
adjust const_eval_select documentation
"The Rust compiler assumes" indicates that this is language UB, but [I don't think that is a good idea](https://rust-lang.zulipchat.com/#narrow/stream/146212-t-compiler.2Fconst-eval/topic/const_eval_select.20assumptions). This UB would be very hard to test for and looks like a way-too-big footgun. ``@oli-obk`` suggested this is meant to be more like "library UB", so I tried to adjust the docs accordingly.
I also removed all references to "referential transparency". That is a rather vague concept used to mean many different things, and I honestly have no idea what exactly is meant by it in this specific instance. But I assume ``@fee1-dead`` had in their mind a property that all `const fn` code upholds, so by demanding that the runtime code and the const-time code are *observably equivalent*, whatever that property is would also be enforced here.
Cc ``@rust-lang/wg-const-eval``
Fix incorrect stability attributes
These two instances were caught in #90356, but that PR isn't going to be merged. I've extracted these to ensure it's still correct.
``@rustbot`` label: +A-stability +C-cleanup +S-waiting-on-review
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
