Don't run `everybody_loops` for rustdoc; instead ignore resolution errors
r? @eddyb
cc @petrochenkov, @GuillaumeGomez, @Manishearth, @ecstatic-morse, @marmeladema
~~Blocked on https://github.com/rust-lang/rust/pull/73743~~ Merged.
~~Blocked on crater run.~~ Crater popped up some ICEs ([now fixed](https://github.com/rust-lang/rust/pull/73566#issuecomment-656934851)). See [crater run](https://crater-reports.s3.amazonaws.com/pr-73566/index.html), [ICEs](https://github.com/rust-lang/rust/pull/73566#issuecomment-653619212).
~~Blocked on #74070 so that we don't make typeck_tables_of public when it shouldn't be.~~ Merged.
Closes#71820, closes#71104, closes#65863.
## What is the motivation for this change?
As seen from a lengthy trail of PRs and issues (https://github.com/rust-lang/rust/pull/73532, https://github.com/rust-lang/rust/pull/73103, https://github.com/rust-lang/rust/issues/71820, https://github.com/rust-lang/rust/issues/71104), `everybody_loops` is causing bugs in rustdoc. The main issue is that it does not preserve the validity of the `DefId` tree, meaning that operations on DefIds may unexpectedly fail when called later. This is blocking intra-doc links (see https://github.com/rust-lang/rust/pull/73101).
This PR starts by removing `everybody_loops`, fixing #71104 and #71820. However, that brings back the bugs seen originally in https://github.com/rust-lang/rust/pull/43348: Since libstd documents items for all platforms, the function bodies sometimes do not type check. Here are the errors from documenting `libstd` with `everybody_loops` disabled and no other changes:
```rust
error[E0433]: failed to resolve: could not find `handle` in `sys`
--> src/libstd/sys/windows/ext/process.rs:13:27
|
13 | let handle = sys::handle::Handle::new(handle as *mut _);
| ^^^^^^ could not find `handle` in `sys`
error[E0425]: cannot find function `symlink_inner` in module `sys::fs`
--> src/libstd/sys/windows/ext/fs.rs:544:14
|
544 | sys::fs::symlink_inner(src.as_ref(), dst.as_ref(), false)
| ^^^^^^^^^^^^^ not found in `sys::fs`
error[E0425]: cannot find function `symlink_inner` in module `sys::fs`
--> src/libstd/sys/windows/ext/fs.rs:564:14
|
564 | sys::fs::symlink_inner(src.as_ref(), dst.as_ref(), true)
| ^^^^^^^^^^^^^ not found in `sys::fs`
```
## Why does this need changes to `rustc_resolve`?
Normally, this could be avoided by simply not calling the `typeck_item_bodies` pass. However, the errors above happen before type checking, in name resolution itself. Since name resolution is intermingled with macro expansion, and rustdoc needs expansion to happen before it knows all items to be documented, there needs to be someway to ignore _resolution_ errors in function bodies.
An alternative solution suggested by @petrochenkov was to not run `everybody_loops` on anything containing a nested `DefId`. This would solve some of the immediate issues, but isn't bullet-proof: the following functions still could not be documented if the items in the body failed to resolve:
- Functions containing a nested `DefId` (https://github.com/rust-lang/rust/issues/71104)
- ~~Functions returning `impl Trait` (https://github.com/rust-lang/rust/pull/43878)~~ These ended up not resolving anyway with this PR.
- ~~`const fn`, because `loop {}` in `const fn` is unstable (https://github.com/rust-lang/rust/issues/43636)~~ `const_loop` was just stabilized.
This also isn't exactly what rustdoc wants, which is to avoid looking at function bodies in the first place.
## What changes were made?
The hack implemented in this PR is to add an option to ignore all resolution errors in function bodies. This is enabled only for rustdoc. Since resolution errors are ignored, the MIR generated will be invalid, as can be seen in the following ICE:
```rust
error: internal compiler error: broken MIR in DefId(0:11 ~ doc_cfg[8787]::uses_target_feature[0]) ("return type"): bad type [type error]
--> /home/joshua/src/rust/src/test/rustdoc/doc-cfg.rs:51:1
|
51 | / pub unsafe fn uses_target_feature() {
52 | | content::should::be::irrelevant();
53 | | }
| |_^
```
Fortunately, rustdoc does not need to access MIR in order to generate documentation. Therefore this also removes the call to `analyze()` in `rustdoc::run_core`. This has the side effect of not generating all lints by default. Most lints are safe to ignore (does rustdoc really need to run liveness analysis?) but `missing_docs` in particular is disabled when it should not be. Re-running `missing_docs` specifically does not help, because it causes the typechecking pass to be run, bringing back the errors from #24658:
```
error[E0599]: no method named `into_handle` found for struct `sys::unix::pipe::AnonPipe` in the current scope
--> src/libstd/sys/windows/ext/process.rs:71:27
|
71 | self.into_inner().into_handle().into_raw() as *mut _
| ^^^^^^^^^^^ method not found in `sys::unix::pipe::AnonPipe`
|
```
Because of #73743, we only run typeck on demand. So this only causes an issue for functions returning `impl Trait`, which were already special cased by `ReplaceFunctionWithBody`. However, it now considers `async fn f() -> T` to be considered `impl Future<Output = T>`, where before it was considered to have a concrete `T` type.
## How will this affect future changes to rustdoc?
- Any new changes to rustdoc will not be able to perform type checking without bringing back resolution errors in function bodies.
+ As a corollary, any new lints cannot require or perform type checking. In some cases this may require refactoring other parts of the compiler to perform type-checking only on-demand, see for example #73743.
+ As a corollary, rustdoc can never again call `tcx.analysis()` unless this PR is reverted altogether.
## Current status
- ~~I am not yet sure how to bring back `missing_docs` without running typeck. @eddyb suggested allowing lints to opt-out of type-checking, which would probably be another rabbit hole.~~ The opt-out was implemented in https://github.com/rust-lang/rust/pull/73743. However, of the rustc lints, now _only_ missing_docs is run and no other lints: https://github.com/rust-lang/rust/pull/73566#issuecomment-650213058. We need a team decision on whether that's an acceptable tradeoff. Note that all rustdoc lints are still run (`intra_doc_link_resolution_failure`, etc). **UPDATE**: This was deemed acceptable in https://github.com/rust-lang/rust/pull/73566#issuecomment-655750237
- ~~The implementation of optional errors in `rustc_resolve` is very brute force, it should probably be moved from `LateResolver` to `Resolver` to avoid duplicating the logic in many places.~~ I'm mostly happy with it now.
- This no longer allows errors in `async fn f() -> T`. This caused breakage in 50 crates out of a full crater run, all of which (that I looked at) didn't compile when run with rustc directly. In other words, it used to be that they could not be compiled but could still be documented; now they can't be documented either. This needs a decision from the rustdoc team on whether this is acceptable breakage. **UPDATE**: This was deemed acceptable in https://github.com/rust-lang/rust/pull/73566#issuecomment-655750237
- ~~This makes `fn typeck_tables_of` in `rustc_typeck` public. This is not desired behavior, but needs the changes from https://github.com/rust-lang/rust/pull/74070 in order to be fixed.~~ Reverted.
Constify most non-trait `Duration` methods as described in #72440
The remaining methods could probably be made const once https://github.com/rust-lang/rust/pull/72449 lands with support for `f<32|64>::is_finite()`.
Reduce the amount of interning and `layout_of` calls in const eval.
r? @ghost
If we just want to get at some bits of a constant, we don't need to intern it before extracting those bits.
Also, if we want to read a `usize` or `bool`, we can fetch the size without invoking a query.
Update docs for str::as_bytes_mut.
* Add "Safety" section describing UTF-8 invariant.
* Remove mention of `from_utf8_mut`. It is not necessary to call
a function to convert the byte slice back to a string slice. The
original string becomes accessible again after the byte slice is
no longer used (as shown in the example code).
Move libstd's default feature to libtest
This commit makes it so `std` no longer has a `default` feature, but
instead the `test` crate has a `default` feature doing the same thing.
The purpose of this commit is to allow Cargo's `-Zbuild-std` command,
which could customize the features of the standard library, to handle
the `default` feature for libstd. Currently Cargo's `-Zbuild-std`
support starts at libtests's manifest as the entry point to the std set
of crates.
Use local links in the alloc docs.
Links to other crates (like core) from the alloc crate were incorrectly using the `https://doc.rust-lang.org/nightly/` absolute (remote) links, instead of relative (local) links. For example, the link to `Result` at https://doc.rust-lang.org/1.44.1/alloc/vec/struct.Vec.html#method.try_reserve goes to /nightly/.
This is because alloc was being documented before core, and rustdoc relies on the existence of the local directory to know if it should use a local or remote link.
There was code that tried to compensate for this (`create_dir_all`), but in #54543 it was broken because instead of running `cargo doc` once for all the crates, it was changed to run `cargo rustdoc` for each crate individually. This means that `create_dir_all` was no longer doing what it was supposed to be doing (creating all the directories before starting).
The solution here is to just build in the correct order (from the dependency leaves towards the root). An alternate solution would be to switch back to running `cargo doc` once (and use RUSTDOCFLAGS for passing in flags). Another alternate solution would be to iterate over the list twice, creating the directories during the first pass.
I also did a little cleanup to remove the "crate-docs" directory. This was added in the past because different crates were built in different directories. Over time, things have been unified (and rustc docs no longer include std), so it is no longer necessary.
Enforce the static symbol order.
By making the proc macro abort if any symbols are out of order.
The commit also changes the proc macro collect multiple errors (of order
or duplicated symbols) and prints them at the end, which is useful if
you have multiple errors.
r? @petrochenkov
Update reference to CONTRIBUTING.md
CONTRIBUTING.md has been migrated to the rustc-dev-guide but some still refer there.
Update them with the appropriate links.
Fixes#74253
Clarify effect of orphan rule changes on From/Into
Updated documentation for `std::convert` and `std::convert::From` to reflect changes to orphan rule in Rust 1.41. It should no longer be necessary to implement `Into` directly, unless targeting an older version.
r? @steveklabnik
By making the proc macro abort if any symbols are out of order.
The commit also changes the proc macro collect multiple errors (of order
or duplicated symbols) and prints them at the end, which is useful if
you have multiple errors.
* Add "Safety" section describing UTF-8 invariant.
* Remove mention of `from_utf8_mut`. It is not necessary to call
a function to convert the byte slice back to a string slice. The
original string becomes accessible again after the byte slice is
no longer used (as shown in the example code).
Updated documentation for `std::convert` and `std::convert::From` to
reflect changes to orphan rule in Rust 1.41. It should no longer be
necessary to implement Into directly, unless targeting an older version.
This commit makes it so `std` no longer has a `default` feature, but
instead the `test` crate has a `default` feature doing the same thing.
The purpose of this commit is to allow Cargo's `-Zbuild-std` command,
which could customize the features of the standard library, to handle
the `default` feature for libstd. Currently Cargo's `-Zbuild-std`
support starts at libtests's manifest as the entry point to the std set
of crates.
Add a 1.45 release note on lto vs. embed-bitcode
I added a bullet for Cargo's use of `embed-bitcode`, since that was even noteworthy enough for the Inside Rust blog. Then more importantly, I added a compatibility note for how this may interact poorly with manually enabling LTO.
r? @Mark-Simulacrum
Initialize default providers only once
This avoids copying a new `Providers` struct for each downstream crate
that wants to use it.
Follow-up to https://github.com/rust-lang/rust/pull/74283 without the perf hit.
r? @eddyb
Handle case of incomplete local ty more gracefully
When encountering a local binding with a type that isn't completed, the
parser will reach a `=` token. When this happen, consider the type
"complete" as far as the parser is concerned to avoid further errors
being emitted by parse recovery logic.
Update cross-compilation README
README seemed rather out of date. I hope the information in my PR is now correct (it was more or less assembled by asking in zulip and learning-by-doing).
improve DiscriminantKind handling
Adds a lang item `discriminant_type` for the associated type `DiscriminantKind::Discriminant`.
Changes the discriminant of generators from `i32` to `u32`, which should not be observable to fix an
oversight where MIR was using `u32` and codegen and typeck used `i32`.
Add margin after doc search results
I found it not really on computer that the last result is right at the bottom of the page. I find it better with margin below (especially when you hover the last element!). A screenshot to show the result:
r? @kinnison
cc @rust-lang/rustdoc @Manishearth @jyn514
Add option to collapse automatically implementors
Fixes#73403
It adds an option (enabled by default) which collapses all implementors impl blocks.
r? @kinnison
cc @rust-lang/rustdoc
RISC-V GNU/Linux as host platform
This PR add a new builder named `dist-riscv64-linux` that builds the compiler toolchain for RISC-V 64-bit GNU/Linux.
r? @alexcrichton
- Move static variables into the innermost scope in which they are used
- Clean up comments
- Remove external_providers; rename local_providers -> providers
`evaluate_obligation` can only be run on types that are already valid.
So rustdoc still has to run typeck even though it doesn't care about the
result.
