Stabilize feature `cstr_from_bytes_until_nul`
This PR seeks to stabilize `cstr_from_bytes_until_nul`.
Partially addresses #95027
This function has only been on nightly for about 10 months, but I think it is simple enough that there isn't harm discussing stabilization. It has also had at least a handful of mentions on both the user forum and the discord, so it seems like it's already in use or at least known.
This needs FCP still.
Comment on potential discussion points:
- eventual conversion of `CStr` to be a single thin pointer: this function will still be useful to provide a safe way to create a `CStr` after this change.
- should this return a length too, to address concerns about the `CStr` change? I don't see it as being particularly useful, and it seems less ergonomic (i.e. returning `Result<(&CStr, usize), FromBytesUntilNulError>`). I think users that also need this length without the additional `strlen` call are likely better off using a combination of other methods, but this is up for discussion
- `CString::from_vec_until_nul`: this is also useful, but it doesn't even have a nightly implementation merged yet. I propose feature gating that separately, as opposed to blocking this `CStr` implementation on that
Possible alternatives:
A user can use `from_bytes_with_nul` on a slice up to `my_slice[..my_slice.iter().find(|c| c == 0).unwrap()]`. However; that is significantly less ergonomic, and is a bit more work for the compiler to optimize compared the direct `memchr` call that this wraps.
## New stable API
```rs
// both in core::ffi
pub struct FromBytesUntilNulError(());
impl CStr {
pub const fn from_bytes_until_nul(
bytes: &[u8]
) -> Result<&CStr, FromBytesUntilNulError>
}
```
cc ```@ericseppanen``` original author, ```@Mark-Simulacrum``` original reviewer, ```@m-ou-se``` brought up some issues on the thin pointer CStr
```@rustbot``` modify labels: +T-libs-api +needs-fcp
Rename `replace_bound_vars_with_*` to `instantiate_binder_with_*`
Mentioning "binder" rather than "bound vars", imo, makes it clearer that we're doing something to the binder as a whole.
Also, "instantiate" is the verb that I'm always reaching for when I'm looking for these functions, and the name that we use in the new solver anyways.
r? types
Make `derive_const` derive properly const-if-const impls
Fixes#107774Fixes#107666
Also fixes rendering of const-if-const bounds in pretty printing.
r? ```@oli-obk``` or ```@fee1-dead```
Change `arena_cache` to not alter the declared query result
This makes the return types a bit clearer, limiting `arena_cache`'s effect to just the computation side. It also makes it easier to potentially remove `arena_cache`.
r? ```@cjgillot```
Update strip-ansi-escapes and vte
This updates strip-ansi-escapes from 0.1.0 to 0.1.1 (and consequently vte).
Changes: https://github.com/luser/strip-ansi-escapes/compare/0.1.0...0.1.1
The only change really is updating vte which fixes some parsing issues (and drops the vendored source size by several megabytes).
Closes#107708
Treat Drop as a rmw operation
Previously, a Drop terminator was considered a move in MIR. This commit changes the behavior to only treat Drop as a mutable access to the dropped place.
In order for this change to be correct, we need to guarantee that
1. A dropped value won't be used again
2. Places that appear in a drop won't be used again before a
subsequent initialization.
We can ensure this to be correct at MIR construction because Drop will only be emitted when a variable goes out of scope, thus having:
* (1) as there is no way of reaching the old value. drop-elaboration
will also remove any uninitialized drop.
* (2) as the place can't be named following the end of the scope.
However, the initialization status, previously tracked by moves, should also be tied to the execution of a Drop, hence the additional logic in the dataflow analyses.
From discussion in [this thread](https://rust-lang.zulipchat.com/#narrow/stream/233931-t-compiler.2Fmajor-changes/topic/.60DROP.60.20to.20.60DROP_IF.60.20compiler-team.23558), originating from https://github.com/rust-lang/compiler-team/issues/558.
See also https://github.com/rust-lang/rust/pull/104488#discussion_r1085556010
Implement cursors for BTreeMap
See the ACP for an overview of the API: https://github.com/rust-lang/libs-team/issues/141
The implementation is split into 2 commits:
- The first changes the internal insertion functions to return a handle to the newly inserted element. The lifetimes involved are a bit hairy since we need a mutable handle to both the `BTreeMap` itself (which holds the root) and the nodes allocated in memory. I have tested that this passes the standard library testsuite under miri.
- The second commit implements the cursor API itself. This is more straightforward to follow but still involves some unsafe code to deal with simultaneous mutable borrows of the tree root and the node that is currently being iterated.
Remove astconv usage in diagnostic
Fixes#107775
Location of the test sucks, I know, but I needed to put it somewhere 😓
The issue here is that the root cause of the issue has nothing to do with what's being tested, so I couldn't really give it a better name. Oh well.
rustdoc: use a newline instead of `<br>` to format code headers
Since these elements now use `white-space: pre-wrap` since #107615, it's fine to use newlines for formatting, which is smaller and a bit less complicated.
Rename `PointerSized` to `PointerLike`
The old name was unnecessarily vague. This PR renames a nightly language feature that I added, so I don't think it needs any additional approval, though anyone can feel free to speak up if you dislike the rename.
It's still unsatisfying that we don't the user which of {size, alignment} is wrong, but this trait really is just a stepping stone for a more generalized mechanism to create `dyn*`, just meant for nightly testing, so I don't think it really deserves additional diagnostic machinery for now.
Fixes#107696, cc ``@RalfJung``
r? ``@eholk``
Since these elements now use `white-space: pre-wrap` since
784665d4ce, it's fine to use newlines
for formatting, which is smaller and a bit less complicated.
Rollup of 8 pull requests
Successful merges:
- #100599 (Add compiler error E0523 long description and test)
- #107471 (rustdoc: do not include empty default-settings tag in HTML)
- #107555 (Modify existing bounds if they exist)
- #107662 (Turn projections into copies in CopyProp.)
- #107695 (Add test for Future inflating arg size to 3x )
- #107700 (Run the tools builder on all PRs)
- #107706 (Mark 'atomic_mut_ptr' methods const)
- #107709 (Fix problem noticed in PR106859 with char -> u8 suggestion)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
llvm-16: Use Triple.h from new header location.
LLVM 16 has moved Triple.h from ADT and into TargetParser.
LLVM [landed a commit](62c7f035b4) this morning moving the header. This change should make rustc continue to build against LLVM main.
Fix problem noticed in PR106859 with char -> u8 suggestion
HN reader `@ayosec` noticed that my #106859 a few weeks back, malfunctions if you have a Unicode escape, the code suggested b'\u{0}' if you tried to use '\u{0}' where a byte should be, when of course b'\u{0}' is not a byte literal, regardless of the codepoint you can't write Unicode escapes in a byte literal at all.
My proposed fix here just checks that the "character" you wrote is fewer than 5 bytes, thus allowing \x7F and similar escapes but conveniently forbidding even the smallest Unicode escape \u{0} before offering the suggestion as before.
I have provided an updated test which includes examples which do and don't work because of this additional rule.
Mark 'atomic_mut_ptr' methods const
There's nothing that would block these methods from being const (just an UnsafeCell get), and it would be helpful for FFI interfaces in static contexts
Related tracking issue: #66893
Run the tools builder on all PRs
Previously, it would only run on changes to subtrees, submodules, or select directories. That made it so that changes to the compiler that broke tools would only be detected on a full bors merge. This makes it so the tools builder runs by default, making it easier to catch breaking changes to clippy (which was the most affected).
r? ``@Mark-Simulacrum`` cc ``@pietroalbini`` ``@flip1995`` ``@m-ou-se``
Split fn_ctxt/adjust_fulfillment_errors from fn_ctxt/checks
This is a follow-up from #106477, addressing a small number of the `FIXME`s that were added, by moving some functions into the new(er) `adjust_fulfillment_errors` module.
More cleanup is possible for this file (and I'll hopefully get around to doing some of that soon) but the very first thing is to just move these functions out.
There should be no "real" changes in this PR, besides minor adjustments to imports and the functions being transferred.
