Stabilize `PanicInfo::message()` and `PanicMessage`
Resolves#66745
This stabilizes the [`PanicInfo::message()`](https://doc.rust-lang.org/nightly/core/panic/struct.PanicInfo.html#method.message) and [`PanicMessage`](https://doc.rust-lang.org/nightly/core/panic/struct.PanicMessage.html).
Demonstration of [custom panic handler](https://github.com/StackOverflowExcept1on/panicker):
```rust
#![no_std]
#![no_main]
extern crate libc;
#[no_mangle]
extern "C" fn main() -> libc::c_int {
panic!("I just panic every time");
}
#[panic_handler]
fn my_panic(panic_info: &core::panic::PanicInfo) -> ! {
use arrayvec::ArrayString;
use core::fmt::Write;
let message = panic_info.message();
let location = panic_info.location().unwrap();
let mut debug_msg = ArrayString::<1024>::new();
let _ = write!(&mut debug_msg, "panicked with '{message}' at '{location}'");
if debug_msg.try_push_str("\0").is_ok() {
unsafe {
libc::puts(debug_msg.as_ptr() as *const _);
}
}
unsafe { libc::exit(libc::EXIT_FAILURE) }
}
```
```
$ cargo +stage1 run --release
panicked with 'I just panic every time' at 'src/main.rs:8:5'
```
- [x] FCP: https://github.com/rust-lang/rust/issues/66745#issuecomment-2198143725
r? libs-api
Cleanup bootstrap check-cfg
This PR cleanup many custom `check-cfg` in bootstrap that have been accumulated over the years.
As well as updating some outdated comments.
In <https://github.com/rust-lang/rust/pull/127134>, the `Debug` impl for
`TypeId` was changed to print a single integer rather than a tuple.
Change this again to print as hex for more concise and consistent
formatting, as was suggested.
Result:
TypeId(0x1378bb1c0a0202683eb65e7c11f2e4d7)
small correction to fmt::Pointer impl
~~The `addr` method does not require `T: Sized`, and is preferred for use over `expose_provenance`.~~
`expose_provenance` does not require `T: Sized`.
Print `TypeId` as a `u128` for `Debug`
Since <https://github.com/rust-lang/rust/pull/121358>, `TypeId` is represented as a `(u64, u64)`. This also made the debug implementation a lot larger, which is especially apparent with pretty formatting.
Change this to convert the inner value back to a `u128` and then print as a tuple struct to make this less noisy.
Current:
TypeId { t: (1403077013027291752, 4518903163082958039) }
TypeId {
t: (
1403077013027291752,
4518903163082958039,
),
}
New:
TypeId(25882202575019293479932656973818029271)
TypeId(
25882202575019293479932656973818029271,
)
Small fixme in core now that split_first has no codegen issues
https://github.com/rust-lang/rust/issues/109328#issuecomment-1677366881
BTW, I have a crate implementing exactly this kind of an iterator: https://github.com/GrigorenkoPV/head-tail-iter and I was wondering if it would be worthwhile to try and make an ACP for it to get it included in std (or maybe itertools). My only doubt is that it kinda incentives writing O(n^2) algorithms and is not the hard to replace with a `while let` loop (just as in this PR).
Rollup of 9 pull requests
Successful merges:
- #123237 (Various rustc_codegen_ssa cleanups)
- #126960 (Improve error message in tidy)
- #127002 (Implement `x perf` as a separate tool)
- #127081 (Add a run-make test that LLD is not being used by default on the x64 beta/stable channel)
- #127106 (Improve unsafe extern blocks diagnostics)
- #127110 (Fix a error suggestion for E0121 when using placeholder _ as return types on function signature.)
- #127114 (fix: prefer `(*p).clone` to `p.clone` if the `p` is a raw pointer)
- #127118 (Show `used attribute`'s kind for user when find it isn't applied to a `static` variable.)
- #127122 (Remove uneccessary condition in `div_ceil`)
r? `@ghost`
`@rustbot` modify labels: rollup
Since <https://github.com/rust-lang/rust/pull/121358>, `TypeId` is
represented as a `(u64, u64)`. This also made the debug implementation a
lot larger, which is especially apparent with pretty formatting.
Make this less noisy by converting the inner value back to a `u128` then
printing as a tuple struct.
Current:
TypeId { t: (1403077013027291752, 4518903163082958039) }
TypeId {
t: (
1403077013027291752,
4518903163082958039,
),
}
New:
TypeId(25882202575019293479932656973818029271)
TypeId(
25882202575019293479932656973818029271,
)
Remove uneccessary condition in `div_ceil`
Previously, `div_ceil` for unsigned integers had a `rhs > 0` for rounding. That condition however is always fulfilled, since `rhs == 0` would mean a division by zero earlier.
Implement new effects desugaring
cc `@rust-lang/project-const-traits.` Will write down notes once I have finished.
* [x] See if we want `T: Tr` to desugar into `T: Tr, T::Effects: Compat<true>`
* [x] Fix ICEs on `type Assoc: ~const Tr` and `type Assoc<T: ~const Tr>`
* [ ] add types and traits to minicore test
* [ ] update rustc-dev-guide
Fixes#119717Fixes#123664Fixes#124857Fixes#126148
docs: say "includes" instead of "does include"
Provides more visual difference between the negative ("does not include") and the positive ("includes"). Both phrases have the same meaning.
core: avoid `extern type`s in formatting infrastructure
```@RalfJung``` [said](https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Use.20of.20.60extern.20type.60.20in.20formatting.20machinery/near/446552837):
>How attached are y'all to using `extern type` in the formatting machinery?
Seems like this was introduced a [long time ago](34ef8f5441). However, it's also [not really compatible with Stacked Borrows](https://github.com/rust-lang/unsafe-code-guidelines/issues/256), and only works currently because we effectively treat references-to-extern-type almost like raw pointers in Stacked Borrows -- which of course is unsound, it's not how LLVM works. I was planning to make Miri emit a warning when this happens to avoid cases like [this](https://github.com/rust-lang/rust/issues/126814#issuecomment-2183816373) where people use extern type specifically to silence Miri without realizing what happens. but with the formatting machinery using extern type, this warning would just show up everywhere...
>
> The "proper" way to do this in Stacked Borrows is to use raw pointers (or `NonNull`).
This PR does just that.
r? ```@RalfJung```
While the numbers are parsed to the correct value, the decimal numbers in the
source were rounded to zero instead of to the nearest, making the literals
different from the values shown in the documentation.
Add more constants, functions, and tests for `f16` and `f128`
This adds everything that was in some way blocked on const eval, since https://github.com/rust-lang/rust/pull/126429 landed. There is a lot of `cfg(bootstrap)` since that is a fairly recent change.
`f128` tests are disabled on everything except x86_64 and Linux aarch64, which are two platforms I know have "good" support for these types - meaning basic math symbols are available and LLVM doesn't hit selection crashes. `f16` tests are enabled on almost everything except for known LLVM crashes. Doctests are only enabled on x86_64.
Tracking issue: https://github.com/rust-lang/rust/issues/116909
fix Drop items getting leaked in Filter::next_chunk
The optimization only makes sense for non-drop elements anyway. Use the default implementation for items that are Drop instead.
It also simplifies the implementation.
fixes#126872
tracking issue #98326
The optimization only makes sense for non-drop elements anyway.
Use the default implementation for items that are Drop instead.
It also simplifies the implementation.
core: VaArgSafe is an unsafe trait
`T: VaArgSafe` is relied on for soundness. Safe impls promise nothing. Therefore this must be an unsafe trait. Slightly pedantic, as only core can impl this, but we *could* choose to unseal the trait. That would allow soundly (but unsafely) implementing this for e.g. a `#[repr(C)] struct` that should be passable by varargs.
Relates to https://github.com/rust-lang/rust/issues/44930
Detect unused structs which derived Default
<!--
If this PR is related to an unstable feature or an otherwise tracked effort,
please link to the relevant tracking issue here. If you don't know of a related
tracking issue or there are none, feel free to ignore this.
This PR will get automatically assigned to a reviewer. In case you would like
a specific user to review your work, you can assign it to them by using
r? <reviewer name>
-->
Fixes#98871
