Support `#[track_caller]` on functions in `extern "Rust" { ... }`
Fixes https://github.com/rust-lang/rust/issues/70830 which is the follow-up to @eddyb's suggestion in https://github.com/rust-lang/rust/pull/69251#discussion_r380791634 to allow `#[track_caller]` on `fn`s in FFI imports, that is, on functions in `extern "Rust" { ... }` blocks.
This requires that the other side, the FFI export, also have the `#[track_caller]` attribute. Otherwise, undefined behavior is triggered and the blame lies, as usual, with the `unsafe { ... }` block which called the FFI imported function.
After this PR, all forms of `fn` items with the right ABI (`"Rust"`) support `#[track_caller]`.
As a drive-by, the PR also hardens the check rejecting `#[naked] #[track_caller]` such that methods and other forms of `fn` items are also considered.
r? @eddyb
cc @rust-lang/lang
save/restore `pessimistic_yield` when entering bodies
This flag is used to make the execution order around `+=` operators
pessimistic. Failure to save/restore the flag was causing independent
async blocks to effect one another, leading to strange ICEs and failed
assumptions.
Fixes#69307
r? @Zoxc
remove false positives of unused_braces
fixes#70717
We could potentially be more aggressive when linting let bindings by checking if there are any explicit `ref`s.
I have been unable to create a snippet which compiles when using braces but has a borrowck error
without them. The closes I've gotten is [the following (playground)](https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=4a1552ebe9648cb13fcb8dd969189a6c).
r? @eddyb
Don't import integer and float modules, use assoc consts 2
Follow up to #70777. I missed quite a lot of places. Partially because I wanted to keep the size of the last PR down, and partially because my regexes were not good enough :)
r? @dtolnay
ty/walk: iterate `GenericArg`s instead of `Ty`s.
Before this PR, `Ty::walk` only iterated over `Ty`s, but that's becoming an increasing problem with `const` generics, as `ty::Const`s in `Substs` are missed by it.
By working with `GenericArg` instead, we can handle both `Ty`s and `ty::Const`s, but also `ty::Region`s, which used to require ad-hoc mechanisms such as `push_regions`.
I've also removed `TraitRef::input_types`, as it's both long obsolete, and easy to misuse.
Miri terminator handling: only do progress sanity check for 'Call' terminator
This will still catch mistakes in bad intrinsic/foreign-item shims, which is the main source of errors here.
Fixes https://github.com/rust-lang/rust/issues/70723
r? @oli-obk
Do not disable field reordering on enums with big discriminant
The field are always re-ordered to minimize padding, regardless of the
alignment of the discriminant
(spinoff from #70477)
typeck/type_of: let wfcheck handle generics in opaque types' substs.
I was working on #70164, and `type_of`'s handling of opaque types seemed to be, by far, the trickiest use of `Ty::walk`, but I believe it wasn't doing anything (see https://github.com/rust-lang/rust/pull/57896#discussion_r396064431 - I suspect, based on glancing at the PR discussion, that an early attempt was kept in, despite becoming just an overcomplicated way to do exactly the same as the previous simple type equality check).
I would've loved to remove `ResolvedOpaqueTy` (keep the `Ty` and lose the `Substs`), but it looks like the MIR borrowck part of the process needs that now, so it would've been added anyway since #57896, even if that PR hadn't happened.
<hr/>
In the process, I've moved the remaining substitution validation to `wfcheck`, which was already handling lifetimes, and kept only `delay_span_bug`s in `type_of`, as an insurance policy.
I've added tests for lifetime and const cases, they seem to be checked correctly now.
(and more uniform than they were in https://github.com/rust-lang/rust/issues/63063#issuecomment-602162804)
However, the quality of the errors is maybe a bit worse, and they don't trigger when there are other errors (not sure if this is due to compilation stop points or something more specific to one opaque type).
r? @nikomatsakis cc @matthewjasper @oli-obk @Aaron1011
Place TLS initializers with relocations in .tdata
Should fix#70673, although I'm not sure how to test this. Perhaps @joshlf could find a MCVE?
Also adds more context to the FIXME.
r? @oli-obk
