don't uniquify regions when canonicalizing
uniquifying causes a bunch of issues, most notably it causes `AliasEq(<?x as Trait<'a>>::Assoc, <?x as Trait<'a>>::Assoc)` to result in ambiguity because both `normalizes-to` paths result in ambiguity and substs equate should trivially succeed but doesn't because we uniquified `'a` to two different regions.
I originally added uniquification to make it easier to deal with requirement 6 from the dev-guide: https://rustc-dev-guide.rust-lang.org/solve/trait-solving.html#requirements
> ### 6. Trait solving must be (free) lifetime agnostic
>
> Trait solving during codegen should have the same result as during typeck. As we erase
> all free regions during codegen we must not rely on them during typeck. A noteworthy example
> is special behavior for `'static`.
cc https://github.com/rust-lang/rustc-dev-guide/pull/1671
Relying on regions being identical may cause ICE during MIR typeck, but even without this PR we can end up relying on that as type inference vars can resolve to types which contain an identical region. Let's land this and deal with any ICE that crop up as we go. Will look at this issue again before stabilization.
r? ```@compiler-errors```
Remove obsolete test case
This test case was supposed to cover issue #31109 at some point.
It never did anything, as the issue was still open at the time of its creation.
When the issue was resolved, the `issue31109` test case was created,
making the existence of this test pointless.
Improve safe transmute error reporting
This patch updates the error reporting when Safe Transmute is not possible between 2 types by including the reason.
Also, fix some small bugs that occur when computing the `Answer` for transmutability.
Clarify that RUST_MIN_STACK may be internally cached
For larger applications it's important that users set `RUST_MIN_STACK` at the start of their program because [`min_stack`](7d3e03666a/library/std/src/sys_common/thread.rs) caches the value. Not doing so can lead to their `env::set_var` call surprisingly not having any effect.
In my own testing `RUST_MIN_STACK` had no effect until I moved it to the top of `main()`. Hopefully this clarification in the docs will help others going forward.
The `std` test straightforwardly can't work without file descriptors;
#99417 tracks moving it out of tests/ui.
`issue-13560.rs` requires the target to support dynamic linking.
`extern-mod-syntax` is interesting. The original test was added to check
if `extern mod` could be parsed correctly and used `extern mod std` and
an import:
138dc3048a (diff-73700e1e851b7a37bc92174635dab726124c82e5bfabbbc45b4a3c2e8e14fadd)
At some point `std::json::Object` was moved out of std to an unstable
rustc-only `extras` crate, and rather than just changing the import it
got changed to use the unstable crate. When `extras` was removed, people
assumed the test was meant to also test rustc_private and changed it to
another unstable crate rather than using something in std.
This changes the test to remove the `rustc_private` import, to allow it
to work properly when cross-compiling.
resolve: Pre-compute non-reexport module children
Instead of repeating the same logic by walking HIR during metadata encoding.
The only difference is that we are no longer encoding `macro_rules` items, but we never currently need them as a part of this list. They can be encoded separately if this need ever arises.
`module_reexports` is also un-querified, because I don't see any reasons to make it a query, only overhead.
Update cargo
4 commits in 7bf43f028ba5eb1f4d70d271c2546c38512c9875..84b7041fd2745ee6b3b4a150314f81aabb78e6b2
2023-04-10 16:01:41 +0000 to 2023-04-13 20:08:40 +0000
- Stabilize `cargo logout` (rust-lang/cargo#11950)
- Add more information to HTTP errors to help with debugging. (rust-lang/cargo#11878)
- Use registry.default for login/logout (rust-lang/cargo#11949)
- Change -C to be unstable (rust-lang/cargo#11960)
This patch updates the error reporting when Safe Transmute is not
possible between 2 types by including the reason.
Also, fix some small bugs that occur when computing the `Answer` for
transmutability.
Added diagnostic for pin! macro in addition to Box::pin if Unpin isn't implemented
I made a PR earlier, but accidentally renamed a branch and that deleted the PR... sorry for the duplicate
Currently, if an operation on `Pin<T>` is performed that requires `T` to implement `Unpin`, the diagnostic suggestion is to use `Box::pin` ("note: consider using `Box::pin`").
This PR suggests pin! as well, as that's another valid way of pinning a value, and avoids a heap allocation. Appropriate diagnostic suggestions were included to highlight the difference in semantics (local pinning for pin! vs non-local for Box::pin).
Fixes#109964
Check for body owner fallibly in error reporting
Sometimes the "body id" we use for an obligation cause is not actually a body owner, like when we're doing WF checking on items.
Fixes#110157
Fix diff option conflict in UI test
Trivial fix for test case `tests/run-make/rustdoc-verify-output-files`,
it's failing on MacOS, the `-u` option specifies the unified context format, while the `-q` option specifies only brief output. These two options are incompatible, since the unified context format produces a more detailed output than the brief output format.
Add inline assembly support for m68k
I believe this should be correct, to the extent I understand the logic around inline assembly. M68k is fairly straightforward here, other than having separate address registers.
Fix btree `CursorMut::insert_after` check
Fixes a check inside `BTreeMap`'s `CursorMut::insert_after`, where it would peek the previous element to check whether the inserted key is below the next one, instead of peeking the next element.
cleanup our region error API
- require `TypeErrCtxt` to always result in an error, closing #108810
- move `resolve_regions_and_report_errors` to the `ObligationCtxt`
- call `process_registered_region_obligations` in `resolve_regions`
- move `resolve_regions` into the `outlives` submodule
- add `#[must_use]` to functions returning lists of errors
r? types
Erase lifetimes above `ty::INNERMOST` when probing ambiguous types
Turns out that `TyCtxt::replace_escaping_bound_vars_uncached` only erases bound vars exactly at `ty::INNERMOST`, and not everything above. This regresses the suggestions for non-lifetime binders, but oh well, I don't really care about those.
Fixes#110052
don't splice from files into pipes in io::copy
This fixes potential data ordering issue where a write performed after a copy operation could become visible in the copy even though it signaled completion.
I assumed that by not setting `SPLICE_F_MOVE` we would be safe and the kernel would do a copy in kernel space and we could avoid the read-write syscall and copy-to/from-userspace costs. But apparently that flag only makes a difference when splicing from a pipe, but not when splicing into it.
Context: https://lkml.org/lkml/2023/2/9/673
I'm surprised the compiler doesn't warn about these. It appears having
an `impl` on a struct is enough to avoid a warning about it never being
constructed.
Preserve argument indexes when inlining MIR
We store argument indexes on VarDebugInfo. Unlike the previous method of relying on the variable index to know whether a variable is an argument, this survives MIR inlining.
We also no longer check if var.source_info.scope is the outermost scope. When a function gets inlined, the arguments to the inner function will no longer be in the outermost scope. What we care about though is whether they were in the outermost scope prior to inlining, which we know by whether we assigned an argument index.
Fixes#83217
I considered using `Option<NonZeroU16>` instead of `Option<u16>` to store the index. I didn't because `TypeFoldable` isn't implemented for `NonZeroU16` and because it looks like due to padding, it currently wouldn't make any difference. But I indexed from 1 anyway because (a) it'll make it easier if later it becomes worthwhile to use a `NonZeroU16` and because the arguments were previously indexed from 1, so it made for a smaller change.
This is my first PR on rust-lang/rust, so apologies if I've gotten anything not quite right.
