## What is an HTML root url?
It tells rustdoc where it should link when documentation for a crate is
not available locally; for example, when a crate is a dependency of a
crate documented with `cargo doc --no-deps`.
## What is the difference between `html_root_url` and `--extern-html-root-url`?
Both of these tell rustdoc what the HTML root should be set to.
`doc(html_root_url)` is set by the crate author, while
`--extern-html-root-url` is set by the person documenting the crate.
These are often different. For example, docs.rs uses
`--extern-html-root-url https://docs.rs/crate-name/version` to ensure
all crates have documentation, even if `html_root_url` is not set.
Conversely, crates such as Rocket set `doc(html_root_url =
"https://api.rocket.rs")`, because they prefer users to view the
documentation on their own site.
Crates also set `html_root_url` to ensure they have
documentation when building locally when offline. This is unfortunate to
require, because it's more work from the library author. It also makes
it impossible to distinguish between crates that want to be viewed on a
different site (e.g. Rocket) and crates that just want documentation to
be visible offline at all (e.g. Tokio). I have authored a separate
change to the API guidelines to no longer recommend doing this:
https://github.com/rust-lang/api-guidelines/pull/230.
## Why change the default?
In the past, docs.rs has been the main user of `--extern-html-root-url`.
However, it's useful for other projects as well. In particular, Cargo
wants to pass it by default when running `--no-deps`
(https://github.com/rust-lang/cargo/issues/8296).
Unfortunately, for these other use cases, the priority order is
inverted. They want to give *precedence* to the URL the crate picks, and
only fall back to the `--extern-html-root` if no `html_root_url` is
present. That allows passing `--extern-html-root` unconditionally,
without having to parse the source code to see what attributes are
present.
For docs.rs, however, we still want to keep the old behavior, so that
all links on docs.rs stay on the site.
Rollup of 10 pull requests
Successful merges:
- #87818 (Fix anchors display in rustdoc)
- #87983 (Use more accurate spans when proposing adding lifetime to item)
- #88012 (Change WASI's `RawFd` from `u32` to `c_int` (`i32`).)
- #88031 (Make `BuildHasher` object safe)
- #88036 (Fix dead code warning when inline const is used in pattern)
- #88082 (Take into account jobs number for rustdoc GUI tests)
- #88109 (Fix environment variable getter docs)
- #88111 (Add background-color on clickable definitions in source code)
- #88129 (Fix dataflow graphviz bug, make dataflow graphviz modules public)
- #88136 (Move private_unused.rs test to impl-trait)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Move private_unused.rs test to impl-trait
This test was added to fix this issue #55124 which is about impl traits but not related with type alias impl traits.
r? `@oli-obk`
`@bors` rollup=always
Matthew's work on improving NLL's "higher-ranked subtype error"s
This PR rebases `@matthewjasper's` [branch](https://github.com/matthewjasper/rust/tree/nll-hrtb-errors) which has great work to fix the obscure higher-ranked subtype errors that are tracked in #57374.
These are a blocker to turning full NLLs on, and doing some internal cleanups to remove some of the old region code.
The goal is so `@nikomatsakis` can take a look at this early, and I'll then do my best to help do the changes and followup work to land this work, and move closer to turning off the migration mode.
I've only updated the branch and made it compile, removed a warning or two.
r? `@nikomatsakis`
(Here's the [zulip topic to discuss this](https://rust-lang.zulipchat.com/#narrow/stream/122657-t-compiler.2Fwg-nll/topic/.2357374.3A.20improving.20higher-ranked.20subtype.20errors.20via.20.2386700) that Niko wanted)
Update `polonius-engine` to 0.13.0
This PR updates the use of `polonius-engine` to the recently released 0.13.0:
- this version renamed a lot of relations to match the current terminology
- "illegal subset relationships errors" (AKA "subset errors" or "universal region errors" in rustc parlance) have been implemented in all variants, and therefore the `Hybrid` variant can be the rustc default once again
- some of the blessed expectations were updated: new tests have been added since the last time I updated the tests, diagnostics have changed, etc.
In particular:
- a few tests had trivial expectations changes such as basic diagnostics changes for the migrate-mode and full NLLs
- others were recursion and lengths limits which emits a file, and under the polonius compare-mode, the folder has a different name
- a few tests were ignored in the NLL compare-mode for reasons that obviously also apply to Polonius
- some diagnostics were unified so that older expectations no longer made sense: the NLL and Polonius outputs were identical.
- in a few cases Polonius gets a chance to emit more errors than NLLs
A few tests in the compare-mode still are super slow and trigger the 60s warning, or OOM rustc during fact generation, and I've detailed these [on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/186049-t-compiler.2Fwg-polonius/topic/Challenges.20for.20move.2Finit.2C.20liveness.2C.20and.20.60Location.3A.3AAll.60):
- `src/test/ui/numbers-arithmetic/saturating-float-casts.rs` -> OOM during rustc fact generation
- `src/test/ui/numbers-arithmetic/num-wrapping.rs`
- `src/test/ui/issues/issue-72933-match-stack-overflow.rs`
- `src/test/ui/issues/issue-74564-if-expr-stack-overflow.rs`
- `src/test/ui/repr/repr-no-niche.rs`
In addition, 2 tests don't currently pass and I didn't want to bless them now: they deal with HRTBs and miss errors that NLLs emit. We're currently trying to see if we need chalk to deal with HRTB errors (as we thought we would have to) but during the recent sprint, we discovered that we may be able to detect some of these errors in a way that resembles subset errors:
- `ui/hrtb/hrtb-just-for-static.rs` -> 3 errors in NLL, 2 in polonius: a missing error about HRTB + needing to outlive 'static
- `ui/issues/issue-26217.rs` -> missing HRTB that makes the test compile instead of emitting an error
We'll keep talking about this at the next sprint as well.
cc `@rust-lang/wg-polonius` r? `@nikomatsakis`
Enable compiler consumers to obtain mir::Body with Polonius facts.
This PR adds a function (``get_body_with_borrowck_facts``) that can be used by compiler consumers to obtain ``mir::Body`` with accompanying borrow checker information.
The most important borrow checker information that [our verifier called Prusti](https://github.com/viperproject/prusti-dev) needs is lifetime constraints. I have not found a reasonable way to compute the lifetime constraints on the Prusti side. In the compiler, the constraints are computed during the borrow checking phase and then dropped. This PR adds an additional parameter to the `do_mir_borrowck` function that tells it to return the computed information instead of dropping it.
The additionally returned information by `do_mir_borrowck` contains a ``mir::Body`` with non-erased lifetime regions and Polonius facts. I have decided to reuse the Polonius facts because this way I needed fewer changes to the compiler and Polonius facts contains other useful information that we otherwise would need to recompute.
Just FYI: up to now, Prusti was obtaining this information by [parsing the compiler logs](b58ced8dfd/prusti-interface/src/environment/borrowck/regions.rs (L25-L39)). This is not only a hacky approach, but we also reached its limits.
r? `@nikomatsakis`
Improve non_fmt_panics suggestion based on trait impls.
This improves the non_fmt_panics lint suggestions by checking first which trait (Display or Debug) are actually implemented on the type.
Fixes https://github.com/rust-lang/rust/issues/87313
Fixes https://github.com/rust-lang/rust/issues/87999
Before:
```
help: add a "{}" format string to Display the message
|
2 | panic!("{}", Some(1));
| +++++
help: or use std::panic::panic_any instead
|
2 | std::panic::panic_any(Some(1));
| ~~~~~~~~~~~~~~~~~~~~~
```
After:
```
help: add a "{:?}" format string to use the Debug implementation of `Option<i32>`
|
2 | panic!("{:?}", Some(1));
| +++++++
help: or use std::panic::panic_any instead
|
2 | std::panic::panic_any(Some(1));
| ~~~~~~~~~~~~~~~~~~~~~
```
r? `@estebank`
Revert "Auto merge of #83417 - erikdesjardins:enableremovezsts, r=oli-obk"
This reverts commit 8007b506ac, reversing changes made to e55c13e109.
Fixes#88043
r? `@oli-obk`
Use note for pointing at bound introducing requirement
Modify output for pointing where a trait bound obligation is introduced in an E0277 from using a span label to using a note in order to always preserve order of the output:
Before:
```
error[E0277]: `<<Self as Case1>::A as Iterator>::Item` doesn't implement `Debug`
--> $DIR/bounds-on-assoc-in-trait.rs:18:28
|
LL | type A: Iterator<Item: Debug>;
| ^^^^^ `<<Self as Case1>::A as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
|
::: $SRC_DIR/core/src/fmt/mod.rs:LL:COL
|
LL | pub trait Debug {
| --------------- required by this bound in `Debug`
|
= help: the trait `Debug` is not implemented for `<<Self as Case1>::A as Iterator>::Item`
```
After:
```
error[E0277]: `<<Self as Case1>::A as Iterator>::Item` doesn't implement `Debug`
--> $DIR/bounds-on-assoc-in-trait.rs:18:28
|
LL | type A: Iterator<Item: Debug>;
| ^^^^^ `<<Self as Case1>::A as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
|
= help: the trait `Debug` is not implemented for `<<Self as Case1>::A as Iterator>::Item`
note: required by a bound in `Debug`
--> $SRC_DIR/core/src/fmt/mod.rs:LL:COL
|
LL | pub trait Debug {
| ^^^^^^^^^^^^^^^ required by this bound in `Debug`
```
Include (potentially remapped) working dir in crate hash
Fixes#85019
A `SourceFile` created during compilation may have a relative
path (e.g. if rustc itself is invoked with a relative path).
When we write out crate metadata, we convert all relative paths
to absolute paths using the current working directory.
However, the working directory is not included in the crate hash.
This means that the crate metadata can change while the crate
hash remains the same. Among other problems, this can cause a
fingerprint mismatch ICE, since incremental compilation uses
the crate metadata hash to determine if a foreign query is green.
This commit moves the field holding the working directory from
`Session` to `Options`, including it as part of the crate hash.
cc `@ohsayan`
Skip assert ICE with default_method_body_is_const
functions marked with #[default_method_body_is_const] would
ICE when being const checked due to it not being a const function:
`tcx.is_const_fn_raw(did)` returns false. We should skip this assert
when it is marked with that attribute.
r? `@oli-obk`
Closure migration multispan suggestions
This changes the `rust_2021_incompatible_closure_captures` lint to only suggest inserting the parts that need to be inserted, instead of suggesting to replace the entire closure by an almost identical closure with one statement added.
Before:
```
[...]
help: add a dummy let to cause `a` to be fully captured
|
5 ~ let _ = || {
6 + let _ = &a;
7 + dbg!(a.0);
8 + println!("1");
9 + println!("2");
10 + println!("3");
...
|
[...]
help: add a dummy let to cause `b` to be fully captured
|
14 | let _ = || { let _ = &b; dbg!(b.0); };
| ~~~~~~~~~~~~~~~~~~~~~~~~~~
[...]
help: add a dummy let to cause `c` to be fully captured
|
16 | let _ = || { let _ = &c; dbg!(c.0) };
| ~~~~~~~~~~~~~~~~~~~~~~~~~
```
After:
```
[...]
help: add a dummy let to cause `a` to be fully captured
|
5 ~ let _ = || {
6 + let _ = &a;
|
[...]
help: add a dummy let to cause `b` to be fully captured
|
14 | let _ = || { let _ = &b; dbg!(b.0); };
| +++++++++++
[...]
help: add a dummy let to cause `c` to be fully captured
|
16 | let _ = || { let _ = &c; dbg!(c.0) };
| +++++++++++++ +
```
Since https://reviews.llvm.org/D103355 this will usually also use
internal rather than private on Windows as well. We don't
particularly care about this implementation detail, just accept
either.
The #[used] attribute explicitly only requires symbols to be
retained in object files, but allows the linker to drop them
if dead. This corresponds to llvm.compiler.used semantics.
The motivation to change this *now* is that https://reviews.llvm.org/D97448
starts emitting #[used] symbols into unique sections with
SHF_GNU_RETAIN flag. This triggers a bug in some version of gold,
resulting in the ARGV_INIT_ARRAY symbol part of the .init_array
section to be incorrectly placed.
