tests: Uncomment now valid GAT code behind FIXME
The code fails to parse with `nightly-2021-02-05`:
$ cargo +nightly-2021-02-05 build
error: generic associated types in trait paths are currently not implemented
--> src/main.rs:9:42
|
9 | fn _bar<T: for<'a> StreamingIterator<Item<'a> = &'a [i32]>>(_iter: T) { /* ... */
| ^^^^
but parses with `nightly-2021-02-06`:
$ cargo +nightly-2021-02-06 build
warning: the feature `generic_associated_types` is incomplete and may not be safe to use and/or cause compiler crashes
warning: 1 warning emitted
because it was (with high probability) fixed by #79554 which was merged within that nightly range.
This PR is part of #44366 which is E-help-wanted.
Allowing re-implementation of mir_drops_elaborated query
For our use case of the rust compiler interface (a rust verifier called [Prusti](https://github.com/viperproject/prusti-dev/)), it would be extremely useful if we were able to "copy" the implementation of the `mir_drops_elaborated_and_const_checked` query to override it. This would mean that the following items would need to be made public:
>6d55184d05/compiler/rustc_mir_transform/src/lib.rs (L434)
>6d55184d05/compiler/rustc_mir_transform/src/inline.rs (L32)
(for the latter its module needs to be public or it needs to be re-exported)
To explain why (we think) this is necessary: I am currently working on a new feature, where we try to modify the generated executables by inserting certain additional checks, and potentially perform some optimizations based on verification results.
We are using the rust compiler interface and most of our goals can be achieved by overriding queries, in our case this is currently `mir_drops_elaborated_and_const_checked`.
However, at the moment this approach is somewhat limited. When overriding queries, we can call and steal the base-query and then modify the results before allocating and returning those.
The problem is that the verification works with a copy of `mir_promoted`. For the modifications we want to make to the mir, we would often want to rely on results of the verifier that refer to Locations in the `mir_promoted`. We can not modify the `mir_promoted` query using these results, because to run the verification we also need the results of `mir_borrowck()`, which means `mir_promoted` will already be constructed and cached.
The Locations we get from the verifier are also no longer usable to modify `mir_drops_elaborated_and_const_checked`, because the MIR obviously changes between those 2 phases. Tracking all Locations between the two seems to be pretty much unfeasible, and would also be extremely unstable.
By being able to override the query with its original implementation, we could modify the MIR before drop elaboration and the various other passes are performed.
I have spent quite a bit of time investigating other solutions, and didn't find any other way solving this problem. If I still missed something I would of course be happy to hear any suggestions that do not require exposing more internal compiler functionality. However, I think being able to re-implement certain queries could also benefit other use cases in the future, for example in PR #108328 one of the approaches discussed involved doing the same thing for `mir_promoted`.
Prevent constant rebuilds of `rustc-main` (and thus everything else)
PR #114305 changed bootstrap to run `strip -g` on `librustc_driver.so` and `libllvm.so` on Linux when no debuginfo was requested. Unfortunately, that PR resulted in bootstrap always rebuilding everything starting from stage 1 `rustc-main` (including stage 1 libraries and tests) when invoking bootstrap multiple times.
We noticed this because Ferrocene's CI times increased to between 2x and 3x total execution time, but the regression can also be reproduced locally by running `./x build library/sysroot --stage 1` twice.
The explanation of the problem is in the code comments.
r? ```@lqd```
cc ```@ozkanonur```
update llvm-wrapper include to silence deprecation warning
Includes of `include/llvm/Support/Host.h` now emit a deprecated warning: `warning: This header is deprecated, please use llvm/TargetParser/Host.h`.
I don't believe we are using this include.
I don't believe we need to bump the `download-ci-llvm` stamp since these warnings are emitted while building the `llvm-wrapper`.
r? ```@nikic```
CFI: Fix error compiling core with LLVM CFI enabled
Fix#90546 by filtering out global value function pointer types from the type tests, and adding the LowerTypeTests pass to the rustc LTO optimization pipelines.
Mention style for new syntax in tracking issue template
`@rust-lang/style` would like the specification of new syntax in the style guide to be part of the feature stabilization process, in order to avoid situations where new syntax is stabilized and it never has style specified or formatting implemented for it. This most recently occurred with [let-else](https://blog.rust-lang.org/2023/07/01/rustfmt-supports-let-else-statements.html). We've made a lot of progress with the [nightly style procedure](https://github.com/rust-lang/style-team/blob/master/nightly-style-procedure.md) to unblock rustfmt from experimenting with formatting for new syntax, and T-style's existence means we actually have people who are willing and qualified to make decisions about formatting specification.
This check-box should also perhaps include "formatting support implemented in rustfmt", but that's really up to `@rust-lang/rustfmt,` so I'm not volunteering them for any new responsibilities in this PR just yet.
Putting this up mostly to discuss with T-lang, though feedback welcome from anyone.
---
As more of an implementation detail: alternatively, instead of a this could be just added to the existing rustc-dev-guide chapter(s) on stabilization.
r? `@ghost`
add aarch64-unknown-teeos target
TEEOS is a mini os run in TrustZone, for trusted/security apps. The libc of TEEOS is a part of musl. The kernel of TEEOS is micro kernel.
This MR is to add a target for teeos.
MRs for libc and rust-std are in progress.
Compiler team MCP: [MCP](https://github.com/rust-lang/compiler-team/issues/652)
Make ExitStatus implement Default
And, necessarily, make it inhabited even on platforms without processes.
I noticed while preparing https://github.com/rust-lang/rfcs/pull/3362 that there was no way for anyone to construct an `ExitStatus`.
This would be insta-stable so needs an FCP.
Add hotness data to LLVM remarks
Slight improvement of https://github.com/rust-lang/rust/pull/113040. This makes sure that if PGO is used, remarks generated using `-Zremark-dir` will include the `Hotness` attribute.
r? `@tmiasko`
The code fails to parse with `nightly-2021-02-05`:
$ cargo +nightly-2021-02-05 build
error: generic associated types in trait paths are currently not implemented
--> src/main.rs:9:42
|
9 | fn _bar<T: for<'a> StreamingIterator<Item<'a> = &'a [i32]>>(_iter: T) { /* ... */
| ^^^^
but parses with `nightly-2021-02-06`:
$ cargo +nightly-2021-02-06 build
warning: the feature `generic_associated_types` is incomplete and may not be safe to use and/or cause compiler crashes
warning: 1 warning emitted
because it was (with high probability) fixed by PR 79554 which was merged
within that nightly range.
Make module inner and function run_analysis_to_runtime_passes in
rustc_mir_transform public to allow re-implementing the query from the
rust compiler interface.
Map RPIT duplicated lifetimes back to fn captured lifetimes
Use the [`lifetime_mapping`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/hir/struct.OpaqueTy.html#structfield.lifetime_mapping) to map an RPIT's captured lifetimes back to the early- or late-bound lifetimes from its parent function. We may be going thru several layers of mapping, since opaques can be nested, so we introduce `TyCtxt::map_rpit_lifetime_to_fn_lifetime` to loop through several opaques worth of mapping, and handle turning it into a `ty::Region` as well.
We can then use this instead of the identity substs for RPITs in `check_opaque_meets_bounds` to address #114285.
We can then also use `map_rpit_lifetime_to_fn_lifetime` to properly install bidirectional-outlives predicates for both RPITs and RPITITs. This addresses #114601.
I based this on #114574, but I don't actually know how much of that PR we still need, so some code may be redundant now... 🤷
---
Fixes#114597Fixes#114579Fixes#114285
Also fixes#114601, since it turns out we had other bugs with RPITITs and their duplicated lifetime params 😅.
Supersedes #114574
r? `@oli-obk`
[rustc_data_structures][base_n][perf] Remove unnecessary utf8 check.
Since all output characters taken from `BASE_64` are valid UTF8 chars there is no need to waste cycles on validation.
Even though it's obviously a perf win, I've also used a [benchmark](https://gist.github.com/ttsugriy/e1e63c07927d8f31e71695a9c617bbf3) on M1 MacBook Air with following results:
```
Running benches/base_n_benchmark.rs (target/release/deps/base_n_benchmark-825fe5895b5c2693)
push_str/old time: [14.670 µs 14.852 µs 15.074 µs]
Found 11 outliers among 100 measurements (11.00%)
4 (4.00%) high mild
7 (7.00%) high severe
push_str/new time: [12.573 µs 12.674 µs 12.801 µs]
Found 11 outliers among 100 measurements (11.00%)
7 (7.00%) high mild
4 (4.00%) high severe
```
rustc_interface: Dismantle `register_plugins` query
It did three independent things:
- Constructed `LintStore`
- Prepared incremental directories and dep graph
- Initialized some fields in `Session`
The `LintStore` construction (now `passes::create_lint_store`) is more or less left in place.
The incremental stuff is now moved into `fn dep_graph_future`.
This helps us to start loading the dep graph a bit earlier.
The `Session` field initialization is moved to tcx construction point.
Now that tcx is constructed early these fields don't even need to live in `Session`, they can live in tcx instead and be initialized at its creation (see the FIXME).
Three previously existing `rustc_interface` queries are de-querified (`register_plugins`, `dep_graph_future`, `dep_graph`) because they are only used locally in `fn global_ctxt` and their results don't need to be saved elsewhere.
On the other hand, `crate_types` and `stable_crate_id` are querified.
They are used from different places and their use is very similar to the existing `crate_name` query in this regard.
Rollup of 7 pull requests
Successful merges:
- #114376 (Avoid exporting __rust_alloc_error_handler_should_panic more than once.)
- #114413 (Warn when #[macro_export] is applied on decl macros)
- #114497 (Revert #98333 "Re-enable atomic loads and stores for all RISC-V targets")
- #114500 (Remove arm crypto target feature)
- #114566 (Store the laziness of type aliases in their `DefKind`)
- #114594 (Structurally normalize weak and inherent in new solver)
- #114596 (Rename method in `opt-dist`)
r? `@ghost`
`@rustbot` modify labels: rollup
Rename method in `opt-dist`
This makes it clearer that the LLVM is the host one (it doesn't necessarily have to be downloaded). On Linux, it comes from the Dockerfile, on Windows it's downloaded.
Suggested here: https://github.com/rust-lang/rust/pull/114344#discussion_r1285596217
r? `@lqd`
Structurally normalize weak and inherent in new solver
It seems pretty obvious to me that we should be normalizing weak and inherent aliases too, since they can always be normalized. This PR still leaves open the question of what to do with opaques, though 💀
**Also**, we need to structurally resolve the target of a coercion, for the UI test to work.
r? `@lcnr`
Store the laziness of type aliases in their `DefKind`
Previously, we would treat paths referring to type aliases as *lazy* type aliases if the current crate had lazy type aliases enabled independently of whether the crate which the alias was defined in had the feature enabled or not.
With this PR, the laziness of a type alias depends on the crate it is defined in. This generally makes more sense to me especially if / once lazy type aliases become the default in a new edition and we need to think about *edition interoperability*:
Consider the hypothetical case where the dependency crate has an older edition (and thus eager type aliases), it exports a type alias with bounds & a where-clause (which are void but technically valid), the dependent crate has the latest edition (and thus lazy type aliases) and it uses that type alias. Arguably, the bounds should *not* be checked since at any time, the dependency crate should be allowed to change the bounds at will with a *non*-major version bump & without negatively affecting downstream crates.
As for the reverse case (dependency: lazy type aliases, dependent: eager type aliases), I guess it rules out anything from slight confusion to mild annoyance from upstream crate authors that would be caused by the compiler ignoring the bounds of their type aliases in downstream crates with older editions.
---
This fixes#114468 since before, my assumption that the type alias associated with a given weak projection was lazy (and therefore had its variances computed) did not necessarily hold in cross-crate scenarios (which [I kinda had a hunch about](https://github.com/rust-lang/rust/pull/114253#discussion_r1278608099)) as outlined above. Now it does hold.
`@rustbot` label F-lazy_type_alias
r? `@oli-obk`
