refactor check_{lang,library}_ub: use a single intrinsic
This enacts the plan I laid out [here](https://github.com/rust-lang/rust/pull/122282#issuecomment-1996917998): use a single intrinsic, called `ub_checks` (in aniticpation of https://github.com/rust-lang/compiler-team/issues/725), that just exposes the value of `debug_assertions` (consistently implemented in both codegen and the interpreter). Put the language vs library UB logic into the library.
This makes it easier to do something like https://github.com/rust-lang/rust/pull/122282 in the future: that just slightly alters the semantics of `ub_checks` (making it more approximating when crates built with different flags are mixed), but it no longer affects whether these checks can happen in Miri or compile-time.
The first commit just moves things around; I don't think these macros and functions belong into `intrinsics.rs` as they are not intrinsics.
r? `@saethlin`
Additional trait bounds beyond the principal trait and its implications
are not possible in the vtable. This means that if a receiver is
`&dyn Foo + Send`, the function will only be expecting `&dyn Foo`.
This strips those auto traits off before CFI encoding.
We already use `Instance` at declaration sites when available to glean
additional information about possible abstractions of the type in use.
This does the same when possible at callsites as well.
The primary purpose of this change is to allow CFI to alter how it
generates type information for indirect calls through `Virtual`
instances.
make CI failures easier to interpret
RUST_BACKTRACE=1 means we show 2 backtraces that are almost always irrelevant: from ui_test and from the miri script. Instead let's set the env var inside the test harness so we see backtraces of Miri ICEing but nothing else.
Rollup of 11 pull requests
Successful merges:
- #120577 (Stabilize slice_split_at_unchecked)
- #122698 (Cancel `cargo update` job if there's no updates)
- #122780 (Rename `hir::Local` into `hir::LetStmt`)
- #122915 (Delay a bug if no RPITITs were found)
- #122916 (docs(sync): normalize dot in fn summaries)
- #122921 (Enable more mir-opt tests in debug builds)
- #122922 (-Zprint-type-sizes: print the types of awaitees and unnamed coroutine locals.)
- #122927 (Change an ICE regression test to use the original reproducer)
- #122930 (add panic location to 'panicked while processing panic')
- #122931 (Fix some typos in the pin.rs)
- #122933 (tag_for_variant follow-ups)
r? `@ghost`
`@rustbot` modify labels: rollup
Report retags as distinct from real memory accesses for data races
This changes the error reporting for data races such that reference invariants are no longer reported as real read and writes.
Before:
```
Data race detected between (1) non-atomic write on thread `unnamed-6` and (2) non-atomic read on thread `unnamed-5` at alloc1034971+0x10c. (2) just happened here
```
After:
```
Data race detected between (1) non-atomic write on thread `unnamed-8` and (2) shared reference invariant on thread `unnamed-6` at alloc1018329+0x190. (2) just happened here
```
Non-atomic read accesses from the *other* thread don't have this information tracked so those are called `some potential non-atomic read access` here.
Change an ICE regression test to use the original reproducer
The ICE was fixed in PR https://github.com/rust-lang/rust/pull/122370, but the test used a different reproducer than the one originally reported. This PR changes it to the original one, giving us more confidence that the fix works.
Fixes#122199
-Zprint-type-sizes: print the types of awaitees and unnamed coroutine locals.
This should assist comprehending the size of coroutines. In particular, whenever a future is suspended while awaiting another future, the latter is given the special name `__awaitee`, and now the type of the awaited future will be printed, allowing identifying caller/callee — er, I mean, poller/pollee — relationships.
It would be possible to include the type name in more cases, but I thought that that might be overly verbose (`print-type-sizes` is already a lot of text) and ordinary named fields or variables are easier for readers to discover the types of.
This change will also synergize with my other PR #122923 which changes type printing to print the path of the `async fn` instead of the span.
Implementation note: I'm not sure if `Symbol::intern` is appropriate for this application, but it was the obvious way to not have to remove the `Copy` implementation from `FieldInfo`, or add a `'tcx` lifetime, while avoiding keeping a lot of possibly redundant strings in memory. I don't know what the proper tradeoff to make here is (though presumably it is not too important for a `-Z` debugging option).
Rename `hir::Local` into `hir::LetStmt`
Follow-up of #122776.
As discussed on [zulip](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/Improve.20naming.20of.20.60ExprKind.3A.3ALet.60.3F).
I made this change into a separate PR because I'm less sure about this change as is. For example, we have `visit_local` and `LocalSource` items. Is it fine to keep these two as is (I supposed it is but I prefer to ask) or not? Having `Node::Local(LetStmt)` makes things more explicit but is it going too far?
r? ```@oli-obk```
Cancel `cargo update` job if there's no updates
Previously there were always updates so we didn't hit this. Since #122489, this job runs on a more frequent schedule and causes errors if there have been no changes in that timespan.
This led to a weird error on https://github.com/rust-lang/rust/pull/122646#issuecomment-2004339093 - because of this I've replaced the `exit 1`s here with `gh run cancel` so we don't have false 'failed' jobs in the logs.
Stabilize slice_split_at_unchecked
Greetings!
I took the opportunity, and I tried to stabilize the `slice_split_at_unchecked` feature. I followed the guidelines, and I hope everything was done correctly 🤞 .
Closes#76014
Let codegen decide when to `mem::swap` with immediates
Making `libcore` decide this is silly; the backend has so much better information about when it's a good idea.
Thus this PR introduces a new `typed_swap` intrinsic with a fallback body, and replaces that fallback implementation when swapping immediates or scalar pairs.
r? oli-obk
Replaces #111744, and means we'll never need more libs PRs like #111803 or #107140
The payload of coverage statements was historically a structure with several
fields, so it was boxed to avoid bloating `StatementKind`.
Now that the payload is a single relatively-small enum, we can replace
`Box<Coverage>` with just `CoverageKind`.
This patch also adds a size assertion for `StatementKind`, to avoid
accidentally bloating it in the future.
