core: Make `Debug` impl of raw pointers print metadata if present
Make Rust pointers appear less magic by including metadata information in their `Debug` output.
This does not break Rust stability guarantees because `Debug` impl are explicitly exempted from stability:
https://doc.rust-lang.org/std/fmt/trait.Debug.html#stability
> ## Stability
>
> Derived `Debug` formats are not stable, and so may change with future Rust versions. Additionally, `Debug` implementations of types provided by the standard library (`std`, `core`, `alloc`, etc.) are not stable, and may also change with future Rust versions.
Note that a regression test is added as a separate commit to make it clear what impact the last commit has on the output.
Closes#128684 because the output of that code now becomes:
```
thread 'main' panicked at src/main.rs:5:5:
assertion `left == right` failed
left: Pointer { addr: 0x7ffd45c6fc6b, metadata: 5 }
right: Pointer { addr: 0x7ffd45c6fc6b, metadata: 3 }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
added some new test to check for result and options opt
Apologies for the delay. Finally have some time to get back into contributing.
## Context
- Added some tests to show optimization on result and options for 64 and 128 bits
- Relevant issue https://github.com/rust-lang/rust/issues/101210
## Some newb questions from me
- [x] My local llvm IR has `nuw` in `result_nop_match_128` etc whereas [godbolt version](https://rust.godbolt.org/z/Td9zoT5zn) doesn't have. So I put optional there, but not sure if it's desirable (maybe I'm not using the compiled llvm in the repo). I ran the test with
```bash
./x test tests/codegen/try_question_mark_nop.rs
```
- [x] Unless I'm reading it wrongly, but `option_nop_match_128` and `option_nop_traits_128` look to be **not** optimized away?
Update:
Here's the test for future reference
```rust
// CHECK-LABEL: `@option_nop_match_128`
#[no_mangle]
pub fn option_nop_match_128(x: Option<i128>) -> Option<i128> {
// CHECK: start:
// CHECK-NEXT: %trunc = trunc nuw i128 %0 to i1
// CHECK-NEXT: br i1 %trunc, label %bb3, label %bb4
// CHECK: bb3:
// CHECK-NEXT: %2 = getelementptr inbounds {{(nuw )?}}i8, ptr %_0, i64 16
// CHECK-NEXT: store i128 %1, ptr %2, align 16
// CHECK: bb4:
// CHECK-NEXT: %storemerge = phi i128 [ 1, %bb3 ], [ 0, %start ]
// CHECK-NEXT: store i128 %storemerge, ptr %_0, align 16
// CHECK-NEXT: ret void
match x {
Some(x) => Some(x),
None => None,
}
}
```
r? `@scottmcm`
Rollup of 16 pull requests
Successful merges:
- #133055 (Expand `CloneToUninit` documentation.)
- #137147 (Add exclude to config.toml)
- #137864 (Don't drop `Rvalue::WrapUnsafeBinder` during GVN)
- #137890 (doc: clarify that consume can be called after BufReader::peek)
- #137956 (Add RTN support to rustdoc)
- #137968 (Properly escape regexes in Python scripts)
- #138082 (Remove `#[cfg(not(test))]` gates in `core`)
- #138275 (expose `is_s390x_feature_detected!` from `std::arch`)
- #138303 (Fix Ptr inconsistency in {Rc,Arc})
- #138309 (Add missing doc for intrinsic (Fix PR135334))
- #138323 (Expand and organize `offset_of!` documentation.)
- #138329 (debug-assert that the size_hint is well-formed in `collect`)
- #138465 (linkchecker: bump html5ever)
- #138471 (Clean up some tests in tests/ui)
- #138472 (Add codegen test for #129795)
- #138484 (Use lit span when suggesting suffix lit cast)
r? `@ghost`
`@rustbot` modify labels: rollup
debug-assert that the size_hint is well-formed in `collect`
Closes#137919
In the hopes of helping to catch any future accidentally-incorrect rustc or stdlib iterators (like the ones #137908 accidentally found), this has `Iterator::collect` call `size_hint` and check its `low` doesn't exceed its `Some(high)`.
There's of course a bazillion more places this *could* be checked, but the hope is that this one is a good tradeoff of being likely to catch lots of things while having minimal maintenance cost (especially compared to putting it in *every* container's `from_iter`).
Expand and organize `offset_of!` documentation.
* Give example of how to get the offset of an unsized tail field (prompted by discussion <https://github.com/rust-lang/rust/pull/133055#discussion_r1986422206>).
* Specify the return type.
* Add section headings.
* Reduce “Visibility is respected…”, to a single sentence.
* Move `offset_of_enum` documentation to unstable book (with link to it).
* Add `offset_of_slice` documentation in unstable book.
r? Mark-Simulacrum
Add missing doc for intrinsic (Fix PR135334)
The previous [PR135334](https://github.com/rust-lang/rust/pull/135334) mentioned that some of the intrinsic APIs were missing safety descriptions.
Among intrinsic APIs that miss safety specifications, most are related to numerical operations. They might need to be discussed and then seen how to organize.
Apart from them, only a few intrinsics lack safety. So this PR deals with the APIs with non-numerical operations in priority.
Fix Ptr inconsistency in {Rc,Arc}
### PR Description
This pr aims to address the problem discussed on [zulip](https://rust-lang.zulipchat.com/#narrow/channel/219381-t-libs/topic/Inconsistency.20in.20.7BRc.2CArc.7D's.20ptr.20requirements/with/504259637).
### Problem Clarification
As this post presents, the `{Rc, Arc}::{in/de-crement_strong_count_/in}` do not limit the layout of the memory that `ptr` points to, while internally `Rc::from_raw_in` is called directly.
UB doesn't just appear when the strong count is decremented to zero. Miri also detects the UB of `out-of-bounds pointer use` when increment strong count is called on a pointer with an incorrect layout(shown as below).
```rust
use std::rc::Rc;
#[repr(align(8))]
struct Aligned8(u64);
#[repr(align(16))]
struct Aligned16(u64);
fn main() {
let rc: Rc<Aligned8> = Rc::new(Aligned8(42));
let raw_ptr = Rc::into_raw(rc);
unsafe {
Rc::increment_strong_count(raw_ptr as *const Aligned16);
}
}
```
Miri output:
```
error: Undefined Behavior: out-of-bounds pointer use: expected a pointer to 32 bytes of memory, but got alloc954 which is only 24 bytes from the end of the allocation
```
Remove `#[cfg(not(test))]` gates in `core`
These gates are unnecessary now that unit tests for `core` are in a separate package, `coretests`, instead of in the same files as the source code. They previously prevented the two `core` versions from conflicting with each other.
Remove `#[cfg(not(test))]` gates in `core`
These gates are unnecessary now that unit tests for `core` are in a separate package, `coretests`, instead of in the same files as the source code. They previously prevented the two `core` versions from conflicting with each other.
Properly escape regexes in Python scripts
According to the [Python 3.12 release note](https://docs.python.org/3/whatsnew/3.12.html#other-language-changes) string literals containing typical invalid escape sequences like `"\d"` are now rejected. There seems to remain only two instances of escape sequences in regex. This change will allow us to work with newer Python interpreter.
Add RTN support to rustdoc
This adds support to rustdoc and rustdoc-json for rendering `(..)` RTN (return type notation) style generics.
---
Cleaning `rustc_middle::ty::Ty` is not correct still, though, and ends up rendering a function like:
```rust
pub fn foreign<T: Foreign<bar(..): Send>>()
where
<T as Foreign>::bar(..): 'static,
T::bar(..): Sync,
```
Into this:
```rust
pub fn foreign<T>()
where
T: Foreign,
impl Future<Output = ()>: Send + 'static + Sync,
```
This is because `clean_middle_ty` doesn't actually have sufficient context about whether the RPITIT is in its "defining scope" or not, so we don't know if the type was originally written like `-> impl Trait` or with RTN like `T::method(..)`.
Partially addresses #123996 (i.e., HIR side, not middle::ty one)
Don't drop `Rvalue::WrapUnsafeBinder` during GVN
...and instead use `Value::WrapUnsafeBinder` to properly propagate consts through `wrap_binder!()` in GVN.
Fixes#137846
r? oli-obk
Expand `CloneToUninit` documentation.
* Clarify relationship to `dyn` after #133003.
* Add an example of using it with `dyn` as #133003 enabled.
* Replace parameter name `dst` with `dest` to avoid confusion between abbreviations for “DeSTination” and “Dynamically-Sized Type”.
* Add an example of implementing it.
* Add links to Rust Reference for the mentioned concepts.
* Mention that its method should rarely be called.
* Various small corrections.
Please review the `unsafe` code closely, as I am not an expert in the best possible ways to express these operations. (It might also be better to omit the implementation example entirely.)
cc `@zachs18` #126799
The existing method does some non-obvious extra work to collect user types and
build user-type projections, which is specifically needed by `declare_bindings`
and not by the other two callers.
Update sccache to 0.10.0
This time, does it also for Windows and macOS. This unifies the sccache version across all OSes that we use.
r? `@ghost`
try-job: dist-aarch64-apple
try-job: dist-x86_64-apple
try-job: dist-x86_64-msvc
try-job: dist-x86_64-msvc-alt
try-job: dist-i686-msvc
try-job: dist-aarch64-msvc
try-job: dist-x86_64-linux
try-job: dist-x86_64-netbsd
Rollup of 5 pull requests
Successful merges:
- #138283 (Enforce type of const param correctly in MIR typeck)
- #138439 (feat: check ARG_MAX on Unix platforms)
- #138502 (resolve: Avoid some unstable iteration)
- #138514 (Remove fake borrows of refs that are converted into non-refs in `MakeByMoveBody`)
- #138524 (Mark myself as unavailable for reviews temporarily)
r? `@ghost`
`@rustbot` modify labels: rollup
