Rollup merge of #71400 - dtolnay:isavailable, r=petrochenkov
proc_macro::is_available()
This PR adds `proc_macro::is_available() -> bool` to determine whether proc_macro has been made accessible to the currently running program.
The proc_macro crate is only intended for use inside the implementation of procedural macros. All the functions in the crate panic if invoked from outside of a procedural macro, such as from a build script or unit test or ordinary Rust binary.
Unfortunately those panics made it impossible for libraries that are designed to support both macro and non-macro use cases (e.g. Syn) to be used from binaries that are compiled with panic=abort. In panic=unwind mode we're able to attempt a proc macro call inside catch_unwind and use libproc_macro's result if it succeeds, otherwise fall back to a non-macro alternative implementation. But in panic=abort there was no way to determine which implementation needs to be used.
Rollup merge of #71369 - ctaggart:wasm32_profiling, r=ecstatic-morse
allow wasm32 compilation of librustc_data_structures/profiling.rs
I'm trying to use rustfmt from a wasm app. I ran into this compilation problem https://github.com/rust-lang/rustfmt/issues/4132 and after investigating, it looked like just adjusting a few cfg's. I based it on how measureme added support in https://github.com/rust-lang/measureme/pull/43.
My testing on my macbook was just that librustc_data_structures builds now with both:
- cargo build
- cargo build --target wasm32-unknown-unknown
Rollup merge of #71256 - cuviper:must_use_replace, r=estebank
Lint must_use on mem::replace
This adds a hint on `mem::replace`, "if you don't need the old value,
you can just assign the new value directly". This is in similar spirit
to the `must_use` on `ManuallyDrop::take`.
Auto merge of #71044 - ecstatic-morse:body-predecessor-cache, r=oli-obk
Remove `BodyAndCache`
...returning to the original approach using interior mutability within `Body`. This simplifies the API at the cost of some uncontended mutex locks when the parallel compiler is enabled.
The current API requires you to either have a mutable reference to `Body` (`&mut BodyAndCache`), or to compute the predecessor graph ahead of time by creating a `ReadOnlyBodyAndCache`. This is not a good fit for, e.g., the dataflow framework, which
1. does not mutate the MIR
2. only sometimes needs the predecessor graph (for backward dataflow problems)
Auto merge of #71431 - Dylan-DPC:rollup-rvm6tfy, r=Dylan-DPC
Rollup of 4 pull requests
Successful merges:
- #71280 (Miri: mplace_access_checked: offer option to force different alignment on place)
- #71336 (Exhaustively match on `{Statement,Terminator}Kind` during const checking)
- #71370 (Added detailed error code explanation for issue E0696 in Rust compiler.)
- #71401 (visit_place_base is just visit_local)
Rollup merge of #71414 - phansch:more-diagnostic-items, r=Manishearth
More diagnostic items for Clippy usage
This adds a couple of more diagnostic items to be used in Clippy.
I chose these particular ones because they were the types which we seem
to check for the most in Clippy. I'm not sure if the `cfg_attr(not(test))`
is needed, but it was also used for `Vec` and a few other types.
cc https://github.com/rust-lang/rust-clippy/issues/5393
Rollup merge of #71412 - dtolnay:uselessdoc, r=Manishearth
Clarify unused_doc_comments note on macro invocations
The previous error message used to say:
<pre>
/// doc
^^^^^^^ rustdoc does not generate documentation for <b>macros</b>
</pre>
Obviously we do generate documentation for macros, such as https://docs.rs/bitflags/1.2.1/bitflags/macro.bitflags.html. It's only macro invocations that don't get their own docs. This PR updates the message to say "rustdoc does not generate documentation for <b>macro invocations</b>".
I observe that prior to #69084 this used to say "rustdoc does not generate documentation for **macro expansions**", as implemented originally in #57882. I don't have a preference between those but I made the commit before looking up the history.
Rollup merge of #70970 - eddyb:trait-vs-impl-mismatch, r=oli-obk
Detect mistyped associated consts in `Instance::resolve`.
*Based on #71049 to prevent redundant/misleading downstream errors.*
Fixes #70942 by refusing to resolve an associated `const` if it doesn't have the same type in the `impl` that it does in the `trait` (which we assume had errored, and `delay_span_bug` guards against bugs).
Philipp Hansch [Wed, 22 Apr 2020 05:47:31 +0000 (07:47 +0200)]
More diagnostic items for Clippy usage
This adds a couple of more diagnostic items to be used in Clippy.
I chose these particular ones because they were the types which we seem
to check for the most in Clippy. I'm not sure if the
`cfg_attr(not(test))` is needed, but it was also used for `Vec` and a
few other types.
Rollup merge of #71366 - faern:use-assoc-int-consts3, r=dtolnay
Use assoc int consts3
Define module level int consts with associated constants instead of `min_value()` and `max_value()`. So the code become consistent with what the docs recommend etc. Seems natural.
Also remove the last usages of the int module constants from this repo (except src/test/ directory which I have still not really done anything in). Some places were missed in the previous PRs because the code uses `crate::<IntTy>` to reach the constants.
Rollup merge of #70998 - estebank:suggest-impl-trait-empty-fn, r=varkor
Suggest `-> impl Trait` and `-> Box<dyn Trait>` on fn that doesn't return
During development, a function could have a return type set that is a
bare trait object by accident. We already suggest using either a boxed
trait object or `impl Trait` if the return paths will allow it. We now
do so too when there are *no* return paths or they all resolve to `!`.
We still don't handle cases where the trait object is *not* the entirety
of the return type gracefully.
Auto merge of #71402 - ehuss:update-cargo, r=ehuss
Update cargo, rls
## cargo
17 commits in ebda5065ee8a1e46801380abcbac21a25bc7e755..8751eb3010d4cdb5329b5a6bd2b6d765c95b0dca
2020-04-16 14:28:43 +0000 to 2020-04-21 18:04:35 +0000
- Uplift windows gnu DLL import libraries. (rust-lang/cargo#8141)
- Add windows-gnu CI and fix tests (rust-lang/cargo#8139)
- Several updates to token/index handling. (rust-lang/cargo#7973)
- Add `resolver` opt-in for new feature resolver. (rust-lang/cargo#8129)
- Improve error message when running `cargo install .` (rust-lang/cargo#8137)
- fix mem replace unused (rust-lang/cargo#8138)
- Change `-Cembed-bitcode=no` use to `-Cbitcode-in-rlib=no`. (rust-lang/cargo#8134)
- Refactor BuildContext (rust-lang/cargo#8068)
- Rename allows_underscores to allows_dashes. (rust-lang/cargo#8135)
- Fixed a needless borrow. (rust-lang/cargo#8130)
- Add link to changelog in the Cargo book. (rust-lang/cargo#8126)
- Fix target for doc test cross compilation (rust-lang/cargo#8094)
- Add note about .cargo/config support. (rust-lang/cargo#8125)
- Fix pdb uplift when executable has dashes. (rust-lang/cargo#8123)
- Hint upgrading for future edition keys (rust-lang/cargo#8122)
- Use some fs shorthand functions. (rust-lang/cargo#8124)
- Update documentation to mention "config.toml" instead of "config" (rust-lang/cargo#8121)
Auto merge of #71367 - Dylan-DPC:rollup-ysj4olr, r=Dylan-DPC
Rollup of 4 pull requests
Successful merges:
- #69362 (Stabilize most common subset of alloc_layout_extras)
- #71174 (Check that main/start is not async)
- #71285 (MIR: use HirId instead of NodeId to avoid cycles while inlining)
- #71346 (Do not build tools if user do not want them)
Rollup merge of #71285 - ljedrz:mir_inline_span_for_optimized_mir, r=ecstatic-morse
MIR: use HirId instead of NodeId to avoid cycles while inlining
I wanted to see if I could limit the number of uses of `NodeId` when `HirId` is available and I saw that some of the MIR `Inliner` code could use `Span` instead of `NodeId`, not unlike in https://github.com/rust-lang/rust/pull/71197.
~If I'm understanding the reason for not calling `optimized_mir` in incremental builds here correctly, this change could also allow us to do so.~
This change could affect performance, so if this approach makes sense, a perf run is probably a good idea.
Combined, these stabilized functions allow code to construct and manipulate `repr(C)` layouts while letting the standard library handle correctness in the face of edge cases. For example use cases, consider the usage in [hashbrown](https://github.com/Amanieu/hashbrown/blob/2f2af1d/src/raw/mod.rs#L143), [crossbeam-skiplist](https://github.com/crossbeam-rs/crossbeam-skiplist/blob/master/src/base.rs#L99), [pointer-utils/slice-dst](https://github.com/CAD97/pointer-utils/blob/92aeefeed9399f28d1b1654b63f8dcbe1242d8d4/crates/slice-dst/src/layout_polyfill.rs), and of course the standard library itself.
Providing a higher-level API such as `Layout::repr_c<const N: usize>(fields: [Layout; N]) -> Result<(Layout, [usize; N]), LayoutErr>` is blocked on const generics, which are a ways off. Providing an API that doesn't provide offsets would be quite suboptimal, as the reason for calculating the layout like this rather than `Layout::new` is to get the field offsets.
The primary issue with the current API is having to call `.pad_to_align()` to match the layout of a `repr(C)` struct. However, I think this is not just a (failing? limitation?) of the API, but rather intrinsic complexity. While all Rust-defined types have size==stride, and probably will for the foreseeable future, there is no inherent reason why this is a limitation of all allocations. As such, the `Layout` manipulation APIs shouldn't impose this limitation, and instead the higher level api of `repr_c` (or just plain old using `Layout::new`) can make keeping it simple.
When the return type is `!Sized` we look for all the returned
expressions in the body to fetch their types and provide a reasonable
suggestion. The tail expression of the body is normally evaluated after
checking whether the return type is `Sized`. Changing the order of the
evaluation produces undesirable knock down effects, so we detect the
specific case that newcomers are likely to encounter ,returning a single
bare trait object, and only in that case we evaluate the tail
expression's type so that the suggestion will be accurate.
Suggest `-> impl Trait` and `-> Box<dyn Trait>` on fn that doesn't return
During development, a function could have a return type set that is a
bare trait object by accident. We already suggest using either a boxed
trait object or `impl Trait` if the return paths will allow it. We now
do so too when there are *no* return paths or they all resolve to `!`.
We still don't handle cases where the trait object is *not* the entirety
of the return type gracefully.
Rollup merge of #71334 - ehuss:pattern-docs, r=kennytm
Update pattern docs.
A few changes to help clarify string pattern usage:
* Add some examples and stability information in the `pattern` module.
* Fixes the links at https://doc.rust-lang.org/std/str/pattern/ because intra-doc-links don't work with re-exported modules (#65983 I think?).
* Consistently use the same phrasing for `str` methods taking a pattern.
* Also mention that array of `char` is also accepted.
When `Pattern` is stabilized, the phrasing in the `str` methods can be updated to be more general to reflect the exact behavior. I'm reluctant to do this now because the stability story for `Pattern` is uncertain. It may perhaps look something like:
> The pattern can be any type that implements the [`Pattern`] trait. Notable examples are `&str`, [`char`], arrays of [`char`], or functions or closures that determines if a character matches. Additional libraries might provide more complex patterns like regular expressions.
This is complicated because methods like `trim_matches` have bounds, which for example don't support `str`, so those methods may need more elaboration.
Rollup merge of #71250 - GuillaumeGomez:use-json-instead-of-js, r=kinnison
Replace big JS dict with JSON parsing
Part of #56545.
@ollie27 suggested that using JSON instead of a JS dict might be faster, so I decided to test it. And the results far exceeded whatever expectations I had...
I used https://github.com/adamgreig/stm32ral for my tests. If you want to build it locally:
```bash
$ cargo doc --features doc --open
```
But I strongly recommend to do it with this PR. Some numbers:
* Loading a page with the JSON search-index: less than 1 second
* Loading a page with the JS search-index: crashed after 30 seconds