Support #[global_allocator] without the allocator shim
This makes it possible to use liballoc/libstd in combination with `--emit obj` if you use `#[global_allocator]`. This is what rust-for-linux uses right now and systemd may use in the future. Currently they have to depend on the exact implementation of the allocator shim to create one themself as `--emit obj` doesn't create an allocator shim.
Note that currently the allocator shim also defines the oom error handler, which is normally required too. Once `#![feature(default_alloc_error_handler)]` becomes the only option, this can be avoided. In addition when using only fallible allocator methods and either `--cfg no_global_oom_handling` for liballoc (like rust-for-linux) or `--gc-sections` no references to the oom error handler will exist.
To avoid this feature being insta-stable, you will have to define `__rust_no_alloc_shim_is_unstable` to avoid linker errors.
(Labeling this with both T-compiler and T-lang as it originally involved both an implementation detail and had an insta-stable user facing change. As noted above, the `__rust_no_alloc_shim_is_unstable` symbol requirement should prevent unintended dependence on this unstable feature.)
rustdoc: Cleanup doc string collapsing
`doc_value` and (former) `collapsed_doc_value` can be implemented in terms of each other, and `doc_value` doesn't need the `Option`.
This PR doesn't do any semantic changes, only refactoring, although some pre-existing choices between `doc_value` and `collapsed_doc_value` across rustdoc may be questionable.
Handle opaques in the new solver (take 2?)
Implement a new strategy for handling opaques in the new solver.
First, queries now carry both their defining anchor and the opaques that were defined in the inference context at the time of canonicalization. These are both used to pre-populate the inference context used by the canonical query.
Second, use the normalizes-to goal to handle opaque types in the new solver. This means that opaques are handled like projection aliases, but with their own rules:
* Can only define opaques if they're "defining uses" (i.e. have unique params in all their substs).
* Can only define opaques that are from the anchor.
* Opaque type definitions are modulo regions. So that means `Opaque<'?0r> = HiddenTy1` and `Opaque<?'1r> = HiddenTy2` equate `HiddenTy1` and `HiddenTy2` instead of defining them as different opaque type keys.
Rollup of 4 pull requests
Successful merges:
- #95198 (Add slice::{split_,}{first,last}_chunk{,_mut})
- #109899 (Use apple-m1 as target CPU for aarch64-apple-darwin.)
- #111624 (Emit diagnostic for privately uninhabited uncovered witnesses.)
- #111875 (Don't leak the function that is called on drop)
r? `@ghost`
`@rustbot` modify labels: rollup
Don't leak the function that is called on drop
It probably wasn't causing problems anyway, but still, a `// this leaks, please don't pass anything that owns memory` is not sustainable.
I could implement a version which does not require `Option`, but it would require `unsafe`, at which point it's probably not worth it.
Use apple-m1 as target CPU for aarch64-apple-darwin.
This updates the target CPU for the `aarch64-apple-darwin` target to `apple-m1`, which is the first generation of CPUs with this target anyway.
This wasn't able to be done before because of the minimum supported version of LLVM being 12, now that it was updated to 13 (in fact we are already at 14), this is available.
See previous update: https://github.com/rust-lang/rust/pull/90478.
See LLVM update: https://github.com/rust-lang/rust/pull/100460.
Rollup of 5 pull requests
Successful merges:
- #111741 (Use `ObligationCtxt` in custom type ops)
- #111840 (Expose more information in `get_body_with_borrowck_facts`)
- #111876 (Roll compiler_builtins to 0.1.92)
- #111912 (Use `Option::is_some_and` and `Result::is_ok_and` in the compiler )
- #111915 (libtest: Improve error when missing `-Zunstable-options`)
r? `@ghost`
`@rustbot` modify labels: rollup
Use `Option::is_some_and` and `Result::is_ok_and` in the compiler
`.is_some_and(..)`/`.is_ok_and(..)` replace `.map_or(false, ..)` and `.map(..).unwrap_or(false)`, making the code more readable.
This PR is a sibling of https://github.com/rust-lang/rust/pull/111873#issuecomment-1561316515
Roll compiler_builtins to 0.1.92
This pulls in the weak-intrinsics feature (which currently defaults off), and a minor version update to libm for the compiler_builtins crate to 0.2.7.
Expose more information in `get_body_with_borrowck_facts`
Verification tools for Rust such as, for example, Creusot or Prusti would benefit from having access to more information computed by the borrow checker.
As a first step in that direction, #86977 added the `get_body_with_borrowck_facts` API, allowing compiler consumers to obtain a `mir::Body` with accompanying borrow checker information.
At RustVerify 2023, multiple people working on verification tools expressed their need for a more comprehensive API.
While eventually borrow information could be part of Stable MIR, in the meantime, this PR proposes a more limited approach, extending the existing `get_body_with_borrowck_facts` API.
In summary, we propose the following changes:
- Permit obtaining the borrow-checked body without necessarily running Polonius
- Return the `BorrowSet` and the `RegionInferenceContext` in `BodyWithBorrowckFacts`
- Provide a way to compute the `borrows_out_of_scope_at_location` map
- Make some helper methods public
This is similar to #108328 but smaller in scope.
`@smoelius` Do you think these changes would also be sufficient for your needs?
r? `@oli-obk`
cc `@JonasAlaif`
Use `ObligationCtxt` in custom type ops
We already make one when evaluating the `CustomTypeOp`, so it's simpler to just pass it to the user. Removes a redundant `ObligationCtxt::new_in_snapshot` usage and simplifies some other code.
This makes several refactorings related to opaque types in the new solver simpler, but those are not included in this PR.
Rollup of 6 pull requests
Successful merges:
- #111121 (Work around `rust-analyzer` false-positive type errors)
- #111759 (Leverage the interval property to precompute borrow kill points.)
- #111841 (Run AST validation on match guards correctly)
- #111862 (Split out opaque collection from from `type_of`)
- #111863 (Don't skip mir typeck if body has errors)
- #111903 (Migrate GUI colors test to original CSS color format)
r? `@ghost`
`@rustbot` modify labels: rollup
