New lint: detect unnecessary struct building
Fixes#10476.
Running this lint on the top 500 crates produced one hit (in `rust-lang/rust-bindgen`) and [a PR has been submitted there](https://github.com/rust-lang/rust-bindgen/pull/2440).
changelog: [`unnecessary_struct_initialization`]: new lint
Move useless_anynous_reexport lint into unused_imports
As mentioned in https://github.com/rust-lang/rust/pull/109003, this check should have been merged with `unused_imports` in the start.
r? `@petrochenkov`
Add `try_canonicalize` to `rustc_fs_util` and use it over `fs::canonicalize`
This adds `try_canonicalize` which tries to call `fs::canonicalize`, but falls back to `std::path::absolute` if it fails. Existing `canonicalize` calls are replaced with it. `fs::canonicalize` is not guaranteed to work on Windows.
Fix the ffi_unwind_calls lint documentation
This fixes the [`ffi_unwind_calls`](https://doc.rust-lang.org/nightly/rustc/lints/listing/allowed-by-default.html#ffi-unwind-calls) documentation to show its output correctly. Currently it is showing the text `{{produces}}` which is not how it should look.
This fixes it by not ignoring the example. I'm not sure why it was ignored, as the way the lint currently works it doesn't seem to require external linkage. This also fixes several mistakes in the example:
* There is no `ffi_unwind_calls` feature.
* Denies the lint (which is otherwise allow be default).
* Removes the `mod impl` which is not valid Rust syntax, and doesn't appear to be needed anyways.
The output now looks like:
```
warning: call to foreign function with FFI-unwind ABI
--> lint_example.rs:10:14
|
10 | unsafe { foo(); }
| ^^^^^ call to foreign function with FFI-unwind ABI
|
note: the lint level is defined here
--> lint_example.rs:2:9
|
2 | #![warn(ffi_unwind_calls)]
| ^^^^^^^^^^^^^^^^
warning: call to function pointer with FFI-unwind ABI
--> lint_example.rs:12:14
|
12 | unsafe { ptr(); }
| ^^^^^ call to function pointer with FFI-unwind ABI
```
This also includes some updates to the lint-docs tool to help with this issue:
* Adds a check if a lint documentation has `{{produces}}` with an ignored example, and generates an error.
* All instances of a lint are now displayed. Previously it only showed the first time the lint fires. Some examples may trigger a lint multiple times, and they are all now displayed.
Lint ambiguous glob re-exports
Attempts to fix#107563.
We currently already emit errors for ambiguous re-exports when two names are re-exported *specifically*, i.e. not from glob exports. This PR attempts to emit deny-by-default lints for ambiguous glob re-exports.
Add `-Z time-passes-format` to allow specifying a JSON output for `-Z time-passes`
This adds back the `-Z time` option as that is useful for [my rustc benchmark tool](https://github.com/Zoxc/rcb), reverting https://github.com/rust-lang/rust/pull/102725. It now uses nanoseconds and bytes as the units so it is renamed to `time-precise`.
Clarify `Error::last_os_error` can be weird
Fundamentally, querying the OS for error codes is a process that is deeply subject to the whims of chance and fortune. We can account for OS, but not for every combination of platform APIs. A compiled binary may not recognize new errors introduced years later. We should clarify a few especially odd situations, and what they mean: We can effectively promise nothing... if you ask for Rust to decode errors where none have occurred.
This allows removing mention of ErrorKind::Uncategorized.
That error variant is hidden deliberately, so we should not explicitly mention it.
This fixes#106937.
Since you had an opinion also: Does this solution seem acceptable?
r? ``@ChrisDenton``
rustc_interface: Add a new query `pre_configure`
It partially expands crate attributes before the main expansion pass (without modifying the crate), and the produced preliminary crate attribute list is used for querying a few attributes that are required very early.
Crate-level cfg attributes on the crate itself are then expanded normally during the main expansion pass, like attributes on any other nodes.
This is a continuation of https://github.com/rust-lang/rust/pull/92473 and one more step to very unstable crate-level proc macro attributes maybe actually working.
Previously crate attributes were pre-configured simultaneously with feature extraction, and then written directly into `ast::Crate`.
Rollup of 7 pull requests
Successful merges:
- #108541 (Suppress `opaque_hidden_inferred_bound` for nested RPITs)
- #109137 (resolve: Querify most cstore access methods (subset 2))
- #109380 (add `known-bug` test for unsoundness issue)
- #109462 (Make alias-eq have a relation direction (and rename it to alias-relate))
- #109475 (Simpler checked shifts in MIR building)
- #109504 (Stabilize `arc_into_inner` and `rc_into_inner`.)
- #109506 (make param bound vars visibly bound vars with -Zverbose)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Rollup of 7 pull requests
Successful merges:
- #108541 (Suppress `opaque_hidden_inferred_bound` for nested RPITs)
- #109137 (resolve: Querify most cstore access methods (subset 2))
- #109380 (add `known-bug` test for unsoundness issue)
- #109462 (Make alias-eq have a relation direction (and rename it to alias-relate))
- #109475 (Simpler checked shifts in MIR building)
- #109504 (Stabilize `arc_into_inner` and `rc_into_inner`.)
- #109506 (make param bound vars visibly bound vars with -Zverbose)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
It partially expands crate attributes before the main expansion pass (without modifying the crate), and the produced preliminary crate attribute list is used for querying a few attributes that are required very early.
Crate-level cfg attributes are then expanded normally during the main expansion pass, like attributes on any other nodes.
Fix cross-compiling with dlltool for raw-dylib
Fix for #103939
Issue Details:
When attempting to cross-compile using the `raw-dylib` feature and the GNU toolchain, rustc would attempt to find a cross-compiling version of dlltool (e.g., `i686-w64-mingw32-dlltool`). The has two issues 1) on Windows dlltool is always `dlltool` (no cross-compiling named versions exist) and 2) it only supported compiling to i686 and x86_64 resulting in ARM 32 and 64 compiling as x86_64.
Fix Details:
* On Windows always use the normal `dlltool` binary.
* Add the ARM64 cross-compiling dlltool name (support for this is coming: https://sourceware.org/bugzilla/show_bug.cgi?id=29964)
* Provide the `-m` argument to dlltool to indicate the target machine type.
(This is the first of two PRs to fix the remaining issues for the `raw-dylib` feature (#58713) that is blocking stabilization (#104218))
make param bound vars visibly bound vars with -Zverbose
I was trying to debug some type/const bound var stuff and it was shockingly tricky due to the fact that even with `-Zverbose` enabled the `T` in `for<T> T: Trait` prints as `T` making it seem like its `TyKind::Param` when it is infact `TyKind::Bound`. This PR "fixes" this when `-Zverbose` is set to allow rendering it as `^T` or `^1_T` depending on binder depth.
r? ```@compiler-errors```
Stabilize `arc_into_inner` and `rc_into_inner`.
Stabilize the `arc_into_inner` and `rc_into_inner` library features and thus close#106894.
The changes in this PR also resolve the FIXMEs for adjusting the documentation upon stabilization, and I’ve additionally included some very minor documentation improvements.
```@rustbot``` label +T-libs-api -T-libs
Simpler checked shifts in MIR building
Doing masking to check unsigned shift amounts is overcomplicated; just comparing the shift directly saves a statement and a temporary, as well as is much easier to read as a human. And shifting by unsigned is the canonical case -- notably, all the library shifting methods (that don't support every type) take shift RHSs as `u32` -- so we might as well make that simpler since it's easy to do so.
This PR also changes *signed* shift amounts to `IntToInt` casts and then uses the same check as for unsigned. The bit-masking is a nice trick, but for example LLVM actually canonicalizes it to an unsigned comparison anyway <https://rust.godbolt.org/z/8h59fMGT4> so I don't think it's worth the effort and the extra `Constant`. (If MIR's `assert` was `assert_nz` then the masking might make sense, but when the `!=` uses another statement I think the comparison is better.)
To review, I suggest looking at 2ee0468c49 first -- that's the interesting code change and has a MIR diff.
My favourite part of the diff:
```diff
- _20 = BitAnd(_19, const 340282366920938463463374607431768211448_u128); // scope 0 at $DIR/shifts.rs:+2:34: +2:44
- _21 = Ne(move _20, const 0_u128); // scope 0 at $DIR/shifts.rs:+2:34: +2:44
- assert(!move _21, "attempt to shift right by `{}`, which would overflow", _19) -> [success: bb3, unwind: bb7]; // scope 0 at $DIR/shifts.rs:+2:34: +2:44
+ _18 = Lt(_17, const 8_u128); // scope 0 at $DIR/shifts.rs:+2:34: +2:44
+ assert(move _18, "attempt to shift right by `{}`, which would overflow", _17) -> [success: bb3, unwind: bb7]; // scope 0 at $DIR/shifts.rs:+2:34: +2:44
```
Make alias-eq have a relation direction (and rename it to alias-relate)
Emitting an "alias-eq" is too strict in some situations, since we don't always want strict equality between a projection and rigid ty. Adds a relation direction.
* I could probably just reuse this [`RelationDir`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_infer/infer/combine/enum.RelationDir.html) -- happy to uplift that struct into middle and use that instead, but I didn't feel compelled to... 🤷
* Some of the matching in `compute_alias_relate_goal` is a bit verbose -- I guess I could simplify it by using [`At::relate`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_infer/infer/at/struct.At.html#method.relate) and mapping the relation-dir to a variance.
* Alternatively, I coulld simplify things by making more helper functions on `EvalCtxt` (e.g. `EvalCtxt::relate_with_direction(T, T)` that also does the nested goal registration). No preference.
r? ```@lcnr``` cc ```@BoxyUwU``` though boxy can claim it if she wants
NOTE: first commit is all the changes, the second is just renaming stuff
Suppress `opaque_hidden_inferred_bound` for nested RPITs
They trigger too much, making repos like linkerd/linkerd2-proxy#2275 sad.
Ideally, at least for RPITs (and probably TAITs?), specifically when we have `impl Trait<Assoc = impl ..>`, that nested opaque should have the necessary `Assoc` item bounds elaborated into its own item bounds. But that's another story.
r? ```@oli-obk```
