rustdoc book: talk about #![doc(test(no_crate_inject))] and #![doc(test(attr(...)))]
While investigating https://github.com/rust-lang/rust/issues/45750 i noticed that `#![doc(test(attr(...)))]` wasn't documented at all. Since this is useful for making your examples follow the same coding guidelines as your code, i wanted to add it to the Rustdoc Book. I also added `#![doc(test(no_crate_inject))]` since it's used in the same place and might be useful for macro-heavy crates. I added mentions for these to "The `doc` attribute" as well as "Documentation tests" since it's useful information in both places.
Technically the step reordering in the second commit is gated on https://github.com/rust-lang/rust/pull/45764, since before that lands attributes from the doctest come before the ones from `#![doc(test(attr(...)))]`.
MIR-borrowck: emit "`foo` does not live long enough" instead of borrow errors
Fixes#45360. As of writing, contains deduplication of existing errors.
r? @nikomatsakis
rustc_trans: atomically write .rmeta outputs to avoid races.
Fixes#45841 in a similar vein to how LLVM writes archives: write a temporary file and then rename it.
r? @alexcrichton
Simplify higher-ranked LUB/GLB
This is a better version of https://github.com/rust-lang/rust/pull/44211. It still makes higher-ranked LUB/GLB into a hard equality test, however, it does try to identify that something changed and issue a notice to the user. I wroteup https://github.com/rust-lang/rust/issues/45852 as a tracking issue for this change.
Currently, this moves straight to a hard-error, on the basis that the crater run in #44211 saw no impact. It might be good to retest -- or perhaps to try for a warning period. Trying to do the latter in a precise way would be somewhat painful, but an imprecise way might suffice -- that is, we could issue warning *whenever* a LUB/GLB operation succeeds that will later fail, even if it doesn't ultimately impact the type check. I could experiment with this.
~~I am *mildly* wary about landing this independently of other code that moves to a universe-based system. In particular, I was nervous that this change would make coherence accepts new pairs of impls that will later be errors. I have the code for the universe-based approach available, I hope to open an PR and run some tests on its impact very shortly.~~ @arielb1 points out that I was being silly.
r? @arielb1
After this change, impl Trait existentials are
desugared to a new `abstract type` definition
paired with a set of lifetimes to apply.
In-scope generics are included as parents of the
`abstract type` generics. Parent regions are
replaced with static, and parent regions
referenced in the `impl Trait` type are duplicated
at the end of the `abstract type`'s generics.
MIR: hide .rodata constants vs by-ref ABI clash in trans.
Back in #45380, constants were copied into locals during MIR creation to ensure that arguments ' memory can be used by the callee, if the constant is placed in `.rodata` and the ABI passes it by-ref.
However, there are several drawbacks (see https://github.com/rust-lang/rust/pull/45380#discussion_r150447709), most importantly the complication of constant propagation (UB if a constant ends up in `Call` arguments) and inconveniencing analyses.
Instead, I've modified the `rustc_trans` implementation of calls to copy an `Operand::Constant` argument locally if it's not immediate, and added a test that segfaults without the copy.
cc @dotdash @arielb1
incr.comp.: Implement query result cache and use it to cache type checking tables.
This is a spike implementation of caching more than LLVM IR and object files when doing incremental compilation. At the moment, only the `typeck_tables_of` query is cached but MIR and borrow-check will follow shortly. The feature is activated by running with `-Zincremental-queries` in addition to `-Zincremental`, it is not yet active by default.
r? @nikomatsakis
