Remember names of `cfg`-ed out items to mention them in diagnostics
# Examples
## `serde::Deserialize` without the `derive` feature (a classic beginner mistake)
I had to slightly modify serde so that it uses explicit re-exports instead of a glob re-export. (Update: a serde PR was merged that adds the manual re-exports)
```
error[E0433]: failed to resolve: could not find `Serialize` in `serde`
--> src/main.rs:1:17
|
1 | #[derive(serde::Serialize)]
| ^^^^^^^^^ could not find `Serialize` in `serde`
|
note: crate `serde` has an item named `Serialize` but it is inactive because its cfg predicate evaluated to false
--> /home/gh-Nilstrieb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/serde-1.0.160/src/lib.rs:343:1
|
343 | #[cfg(feature = "serde_derive")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
344 | pub use serde_derive::{Deserialize, Serialize};
| ^^^^^^^^^
= note: the item is gated behind the `serde_derive` feature
= note: see https://doc.rust-lang.org/cargo/reference/features.html for how to activate a crate's feature
```
(the suggestion is not ideal but that's serde's fault)
I already tested the metadata size impact locally by compiling the `windows` crate without any features. `800k` -> `809k`
r? `@ghost`
Rollup of 6 pull requests
Successful merges:
- #112076 (Fall back to bidirectional normalizes-to if no subst-relate candidate in alias-relate goal)
- #112122 (Add `-Ztrait-solver=next-coherence`)
- #112251 (rustdoc: convert `if let Some()` that always matches to variable)
- #112345 (fix(expand): prevent infinity loop in macro containing only "///")
- #112359 (Respect `RUST_BACKTRACE` for delayed bugs)
- #112382 (download-rustc: Fix `x test core` on MacOS)
r? `@ghost`
`@rustbot` modify labels: rollup
download-rustc: Fix `x test core` on MacOS
before, this hardcoded `.so` as the extension for dynamically linked objects, which is incorrect everywhere except linux.
Respect `RUST_BACKTRACE` for delayed bugs
Sometimes, especially with MIR validation, the backtraces from delayed bugs are noise and make it harder to look at them. Respect the environment variable and don't print it when the user doesn't want it.
fix(expand): prevent infinity loop in macro containing only "///"
Fixes https://github.com/rust-lang/rust/issues/112342
Issue #112342 was caused by an infinity loop in `parse_tt_inner`, and the state of it is as follows:
- `matcher`: `[Sequence, Token(Doc), SequenceKleeneOpNoSep(op: ZeroOrMore), Eof]`
- loop:
| Iteration | Action |
| - | - |
| 0 | enter `Sequence`|
| 1 | enter `Token(Doc)` and `mp.idx += 1` had been executed |
| 2 | enter `SequenceKleeneOpNoSep` and reset `mp.idx` to `1` |
| 3 | enter `Token(Doc)` again|
To prevent the infinite loop, a check for whether it only contains `DocComment` in `check_lhs_no_empty_seq` had been added.
Add `-Ztrait-solver=next-coherence`
Flag that conditionally uses the trait solver *only* during coherence, for more testing and/or eventual partial-migration onto the trait solver (in the medium- to long-term).
* This still uses the selection context in some of the coherence methods I think, so it's not "complete". Putting this up for review and/or for further work in-tree.
* I probably need to spend a bit more time making sure that we don't sneakily create any other infcx's during coherence that also need the new solver enabled.
r? `@lcnr`
Fall back to bidirectional normalizes-to if no subst-relate candidate in alias-relate goal
Sometimes we get into the case where the choice of normalizes-to branch in alias-relate are both valid, but we cannot make a choice of which one to take because they are different -- either returning equivalent but permuted region constraints, or equivalent opaque type definitions but differing modulo normalization.
In this case, we can make progress by considering a fourth candidate where we compute both normalizes-to branches together and canonicalize that as a response. This is essentially the AND intersection of both normalizes-to branches. In an ideal world, we'd be returning something more like the OR intersection of both branches, but we have no way of representing that either for regions (maybe eventually) or opaques (don't see that happening ever).
This is incomplete, so like the subst-relate fallback it's only considered outside of coherence. But it doesn't seem like a dramatic strengthening of inference or anything, and is useful for helping opaque type inference succeed when the hidden type is a projection.
## Example
Consider the goal - `AliasRelate(Tait, <[i32; 32] as IntoIterator>::IntoIter)`.
We have three ways of currently solving this goal:
1. SubstRelate - fails because we can't directly equate the substs of different alias kinds.
2. NormalizesToRhs - `Tait normalizes-to <[i32; 32] as IntoIterator>::IntoIter`
* Ends up infering opaque definition - `Tait := <[i32; 32] as IntoIterator>::IntoIter`
3. NormalizesToLhs - `<[i32; 32] as IntoIterator>::IntoIter normalizes-to Tait`
* Find impl candidate, substitute the associated type - `std::array::IntoIter<i32, 32>`
* Equate `std::array::IntoIter<i32, 32>` and `Tait`
* Ends up infering opaque definition - `Tait := std::array::IntoIter<i32, 32>`
The problem here is that 2 and 3 are essentially both valid, since we have aliases that normalize on both sides, but due to lazy norm, they end up inferring different opaque type definitions that are only equal *after* normalizing them further.
---
r? `@lcnr`
Emit an error when return-type-notation is used with type/const params
These are not intended to be supported initially, even though the compiler supports them internally...
Add `task::Waker::noop`
I have found myself reimplementing this function many times when I need a `Context` but don't have a runtime or `futures` to hand.
Prior art: [`futures::task::noop_waker`](https://docs.rs/futures/0.3/futures/task/fn.noop_waker.html) and [`futures::task::noop_waker_ref`](https://docs.rs/futures/0.3/futures/task/fn.noop_waker_ref.html)
Tracking issue: https://github.com/rust-lang/rust/issues/98286
Unresolved questions:
1. Should we also add `RawWaker::noop()`? (I don't think so, I can't think of a use case for it)
2. Should we also add `Context::noop()`? Depending on the future direction `Context` goes a "noop context" might not even make sense in future.
3. Should it be an associated constant instead? That would allow for `let cx = &mut Context::from_waker(&Waker::NOOP);` to work on one line which is pretty nice. I don't really know what the guideline is here.
r? rust-lang/libs-api `@rustbot` label +T-libs-api -T-libs
Improved std support for ps vita target
Fixed a couple of things in std support for ps vita via Vita SDK newlib oss implementation:
- Added missing hardware features to target spec
- Compile in thumb by default (newlib is also compiled in thumb)
- Fixed fs calls. Vita newlib has a not-very-posix dirent. Also vita does not expose inodes, it's stubbed as 0 in stat, and I'm stubbing it here for dirent (because vita newlibs's dirent doesn't even have that field)
- Enabled signal handlers for panic unwinding
- Dropped static link requirement from the platform support md. Also, rearranged sections to better stick with the template.
This loop is doing two different things. For inlined items, it's adding
them to the CGU. For all items, it's recording them in
`mono_item_placements`.
This commit splits it into two separate loops. This avoids putting root
mono items into `reachable`, and removes the low-value check that
`roots` doesn't contain inlined mono items.
Currently it sorts by symbol name, which is a mangled name like
`_ZN1a4main17hb29587cdb6db5f42E`, which leads to non-obvious orderings.
This commit changes it to use the existing
`items_in_deterministic_order`, which iterates in source code order.
Run tests on PGO/LTO/BOLT optimized dist artifacts
This PR adds baisc tests for the optimized dist builds on x64 Linux and Windows. A subset of the test suite is run, so it's not perfect, but it's better than the status quo (which is basically no testing at all, apart from the perf bot on Linux).
r? `@ghost`
- remove useless commands from test Makefile
- do not unnecessarily remove metadata temporary files because they'll be managed by MaybeTempDir
- remove unused FailedRemove error introduced by this PR
If `-o -` or `--emit KIND=-` is provided, output will be written
to stdout instead. Binary output (`obj`, `llvm-bc`, `link` and
`metadata`) being written this way will result in an error unless
stdout is not a tty. Multiple output types going to stdout will
trigger an error too, as they will all be mixded together.
Remove default visitor impl in region constraint generation
I wanted to group it together with other possibly minor borrowck cleanups but that's all I have right now so I rather put it up than forget about it before doing something else.
r? `@compiler-errors`
Add new Tier-3 targets: `loongarch64-unknown-none*`
This PR adds new Tier-3 targets `loongarch64-unknown-none*` that are introduced by MCP rust-lang/compiler-team#628
Sometimes, especially with MIR validation, the backtraces from delayed
bugs are noise and make it harder to look at them. Respect the
environment variable and don't print it when the user doesn't want it.
