Don't panic when an external crate can't be resolved
This isn't actually a bug, it can occur when rustdoc tries to resolve a
crate that isn't used in the main code.
Fixes#72381.
r? `@kinnison` if you have time, otherwise `@Manishearth`
Don't time `emit_ignored_resolution_errors`
This printed several hundred lines each time rustdoc was run, almost all
of which rounded to 0.000. Since this isn't useful info, don't print it
everywhere, so other perf info is easier to read.
r? `@Mark-Simulacrum`
This printed several hundred lines each time rustdoc was run, almost all
of which rounded to 0.000. Since this isn't useful info, don't print it
everywhere, so other perf info is easier to read.
Allow making `RUSTC_BOOTSTRAP` conditional on the crate name
Motivation: This came up in the [Zulip stream](https://rust-lang.zulipchat.com/#narrow/stream/233931-t-compiler.2Fmajor-changes/topic/Require.20users.20to.20confirm.20they.20know.20RUSTC_.E2.80.A6.20compiler-team.23350/near/208403962) for https://github.com/rust-lang/compiler-team/issues/350.
See also https://github.com/rust-lang/cargo/pull/6608#issuecomment-458546258; this implements https://github.com/rust-lang/cargo/issues/6627.
The goal is for this to eventually allow prohibiting setting `RUSTC_BOOTSTRAP` in build.rs (https://github.com/rust-lang/cargo/issues/7088).
## User-facing changes
- `RUSTC_BOOTSTRAP=1` still works; there is no current plan to remove this.
- Things like `RUSTC_BOOTSTRAP=0` no longer activate nightly features. In practice this shouldn't be a big deal, since `RUSTC_BOOTSTRAP` is the opposite of stable and everyone uses `RUSTC_BOOTSTRAP=1` anyway.
- `RUSTC_BOOTSTRAP=x` will enable nightly features only for crate `x`.
- `RUSTC_BOOTSTRAP=x,y` will enable nightly features only for crates `x` and `y`.
## Implementation changes
The main change is that `UnstableOptions::from_environment` now requires
an (optional) crate name. If the crate name is unknown (`None`), then the new feature is not available and you still have to use `RUSTC_BOOTSTRAP=1`. In practice this means the feature is only available for `--crate-name`, not for `#![crate_name]`; I'm interested in supporting the second but I'm not sure how.
Other major changes:
- Added `Session::is_nightly_build()`, which uses the `crate_name` of
the session
- Added `nightly_options::match_is_nightly_build`, a convenience method
for looking up `--crate-name` from CLI arguments.
`Session::is_nightly_build()`should be preferred where possible, since
it will take into account `#![crate_name]` (I think).
- Added `unstable_features` to `rustdoc::RenderOptions`
I'm not sure whether this counts as T-compiler or T-lang; _technically_ RUSTC_BOOTSTRAP is an implementation detail, but it's been used so much it seems like this counts as a language change too.
r? `@joshtriplett`
cc `@Mark-Simulacrum` `@hsivonen`
Recognize `private_intra_doc_links` as a lint
Previously, trying to allow this would give another error!
```
warning: unknown lint: `private_intra_doc_links`
--> private.rs:1:10
|
1 | #![allow(private_intra_doc_links)]
| ^^^^^^^^^^^^^^^^^^^^^^^ help: did you mean: `broken_intra_doc_links`
|
= note: `#[warn(unknown_lints)]` on by default
warning: public documentation for `DocMe` links to private item `DontDocMe`
--> private.rs:2:11
|
2 | /// docs [DontDocMe]
| ^^^^^^^^^ this item is private
|
= note: `#[warn(private_intra_doc_links)]` on by default
= note: this link will resolve properly if you pass `--document-private-items`
```
Fixes the issue found in https://github.com/rust-lang/rust/pull/77249#issuecomment-712339227.
r? ````````@Manishearth````````
Does anyone know why this additional step is necessary? It seems weird this has to be declared in 3 different places.
The main change is that `UnstableOptions::from_environment` now requires
an (optional) crate name. If the crate name is unknown (`None`), then the new feature is not available and you still have to use `RUSTC_BOOTSTRAP=1`. In practice this means the feature is only available for `--crate-name`, not for `#![crate_name]`; I'm interested in supporting the second but I'm not sure how.
Other major changes:
- Added `Session::is_nightly_build()`, which uses the `crate_name` of
the session
- Added `nightly_options::match_is_nightly_build`, a convenience method
for looking up `--crate-name` from CLI arguments.
`Session::is_nightly_build()`should be preferred where possible, since
it will take into account `#![crate_name]` (I think).
- Added `unstable_features` to `rustdoc::RenderOptions`
There is a user-facing change here: things like `RUSTC_BOOTSTRAP=0` no
longer active nightly features. In practice this shouldn't be a big
deal, since `RUSTC_BOOTSTRAP` is the opposite of stable and everyone
uses `RUSTC_BOOTSTRAP=1` anyway.
- Add tests
Check against `Cheat`, not whether nightly features are allowed.
Nightly features are always allowed on the nightly channel.
- Only call `is_nightly_build()` once within a function
- Use booleans consistently for rustc_incremental
Sessions can't be passed through threads, so `read_file` couldn't take a
session. To be consistent, also take a boolean in `write_file_header`.
Originally I tried to do a much broader refactoring that got rid of `init_lints` altogether. My reasoning is that now the lints aren't being run anymore (after https://github.com/rust-lang/rust/pull/73566), there's no need to ignore them explicitly. But it seems there are still some lints that aren't affected by setting `lint_mod` to a no-op:
```
deny(pub_use_of_private_extern_crate)
deny(const_err)
warn(unused_imports)
```
(there are possibly more, these are just the ones that failed in the rustdoc test suite).
Some of these seem like we really should be warning about, but that's a much larger change and I don't propose to make it here. So for the time being, this just adds the `unknown_lints` and `renamed_or_removed_lints` passes to the list of lints rustdoc warns about.
Fix intra-doc links for associated items
@Manishearth and I found that links of the following sort are broken:
```rust
$ cat str_from.rs
/// [`String::from`]
pub fn foo() {}
$ rustdoc str_from.rs
warning: `[String::from]` cannot be resolved, ignoring it.
--> str_from.rs:4:6
|
4 | /// [`String::from`]
| ^^^^^^^^^^^^^^ cannot be resolved, ignoring
```
It turns out this is because the current implementation only looks at inherent impls (`impl Bar {}`) and traits _for the item being documented_. Note that this is not the same as the item being _linked_ to. So this code would work:
```rust
pub trait T1 {
fn method();
}
pub struct S;
impl T1 for S {
/// [S::method] on method
fn method() {}
}
```
but putting the documentation on `trait T1` would not.
~~I realized that writing it up that my fix is only partially correct: It removes the inherent impls code when it should instead remove the `trait_item` code.~~ Fixed.
Additionally, I discovered while writing this there is some ambiguity: you could have multiple methods with the same name, but for different traits:
```rust
pub trait T1 {
fn method();
}
pub trait T2 {
fn method();
}
/// See [S::method]
pub struct S;
```
Rustdoc should give an ambiguity error here, but since there is currently no way to disambiguate the traits (https://github.com/rust-lang/rust/issues/74563) it does not (https://github.com/rust-lang/rust/pull/74489#issuecomment-673878404).
There is a _third_ ambiguity that pops up: What if the trait is generic and is implemented multiple times with different generic parameters? In this case, my fix does not do very well: it thinks there is only one trait instantiated and links to that trait:
```
/// [`String::from`] -- this resolves to https://doc.rust-lang.org/nightly/alloc/string/struct.String.html#method.from
pub fn foo() {}
```
However, every `From` implementation has a method called `from`! So the browser picks a random one. This is not the desired behavior, but it's not clear how to avoid it.
To be consistent with the rest of intra-doc links, this only resolves associated items from traits that are in scope. This required changes to rustc_resolve to work cross-crate; the relevant commits are prefixed with `resolve: `. As a bonus, considering only traits in scope is slightly faster. To avoid re-calculating the traits over and over, rustdoc uses a cache to store the traits in scope for a given module.
This avoids taking the slow path several thousand times in a row.
- Fallback to all traits if the traits in scope are unknown
- Use a rustdoc thread_local cache instead of a query
The set of traits implemented by a type is not stable across crates:
there could be new traits added in a new crate.
- Use DocContext instead of a thread-local
Doc alias checks: ensure only items appearing in search index can use it
Following the discussion in #73721, I added checks to ensure that only items appearing in the search are allowed to have doc alias.
r? @ollie27
