Resolve intra-doc links on additional documentation for re-exports in lexical scope
Fixes https://github.com/rust-lang/rust/issues/77254.
- Preserve the parent module of `DocFragment`s
+ Add `parent_module` to `DocFragment`
+ Require the `parent_module` of the item being inlined
+ Preserve the hir_id for ExternCrates so rustdoc can find the parent module later
+ Take an optional `parent_module` for `build_impl` and `merge_attrs`.
Preserve the difference between parent modules for each doc-comment.
+ Support a single additional re-exports in from_ast. Originally this took a vec but I ended up not using it.
+ Don't require the parent_module for all `impl`s, just inlined items
In particular, this will be `None` whenever the attribute is not on a
re-export.
+ Only store the parent_module, not the HirId
When re-exporting a re-export, the HirId is not available. Fortunately,
`collect_intra_doc_links` doesn't actually need all the info from a
HirId, just the parent module.
- Introduce `Divider`
This distinguishes between documentation on the original from docs on the re-export.
- Use the new module information for intra-doc links
+ Make the parent module conditional on whether the docs are on a re-export
+ Make `resolve_link` take `&Item` instead of `&mut Item`
Previously the borrow checker gave an error about multiple mutable
borrows, because `dox` borrowed from `item`.
+ Fix `crate::` for re-exports
`crate` means something different depending on where the attribute
came from.
+ Make it work for `#[doc]` attributes too
This required combining several attributes as one so they would keep
the links.
r? `@GuillaumeGomez`
Implementation of RFC2867
https://github.com/rust-lang/rust/issues/74727
So I've started work on this, I think my next steps are to make use of the `instruction_set` value in the llvm codegen but this is the point where I begin to get a bit lost. I'm looking at the code but it would be nice to have some guidance on what I've currently done and what I'm doing next 😄
Add compile fail test for issue 27675
A recently merged PR (#73905) strengthened the checks on bounds of associated items. This rejects the attack path of #27675 which consisted of constructing a `dyn Trait<Item=T>` where `T` would not fulfill the bounds required on `Item` of the `Trait` behind the dyn object.
This regression test, extracted from [the weaponized instance](https://github.com/rust-lang/rust/issues/27675#issuecomment-696956878), checks that this is rejected.
(docs): make mutex error comment consistent with codebase
Although exceptionally minor, I found this stands out from other error reporting language used in doc comments. With the existence of the `failure` crate, I suppose this could be slightly ambiguous. In any case, this change brings the particular comment into a consistent state with other mentions of returning errors.
BTreeMap: comment why drain_filter's size_hint is somewhat pessimistic
The `size_hint` of the `DrainFilter` iterator doesn't adjust as you iterate. This hardly seems important to me, but there has been a comparable PR #64383 in the past. I guess a scenario is that you first iterate half the map manually and keep most of the key/value pairs in the map, and then tell the predicate to drain most of the key/value pairs and `.collect` the iterator over the remaining half of the map.
I am totally ambivalent whether this is better or not.
r? @Mark-Simulacrum
Upgrade to tracing-subscriber 0.2.13
The primary motivation is to get the changes from
https://github.com/tokio-rs/tracing/pull/990. Example output:
```
$ RUSTDOC_LOG=debug rustdoc +rustc2
warning: some trace filter directives would enable traces that are disabled statically
| `debug` would enable the DEBUG level for all targets
= note: the static max level is `info`
= help: to enable DEBUG logging, remove the `max_level_info` feature
```
r? `@Mark-Simulacrum`
cc `@hawkw` ❤️
Use `pretty::create_dump_file` for dumping dataflow results
The old code wasn't incorporating promoteds into the path, meaning other `dot` files could get clobbered. Use the MIR dump infrastructure to generate paths so that this doesn't occur in the future.
- Make the parent module conditional on whether the docs are on a re-export
- Make `resolve_link` take `&Item` instead of `&mut Item`
Previously the borrow checker gave an error about multiple mutable
borrows, because `dox` borrowed from `item`.
- Fix `crate::` for re-exports
`crate` means something different depending on where the attribute
came from.
- Make it work for `#[doc]` attributes too
This required combining several attributes as one so they would keep
the links.
- Add `parent_module` to `DocFragment`
- Require the `parent_module` of the item being inlined
- Preserve the hir_id for ExternCrates so rustdoc can find the parent module later
- Take an optional `parent_module` for `build_impl` and `merge_attrs`.
Preserve the difference between parent modules for each doc-comment.
- Support arbitrarily many re-exports in from_ast. In retrospect this is
probably not used and could be simplified to a single
`Option<(Attrs, DefId)>`.
- Don't require the parent_module for all `impl`s, just inlined items
In particular, this will be `None` whenever the attribute is not on a
re-export.
- Only store the parent_module, not the HirId
When re-exporting a re-export, the HirId is not available. Fortunately,
`collect_intra_doc_links` doesn't actually need all the info from a
HirId, just the parent module.
Unset GIT_DIR in pre-commit hook
Works around https://github.com/rust-lang/rust/issues/77620. This won't help any other hooks you write manually, but hopefully people won't feel the need to do that now there's an 'official' one.
r? `@Mark-Simulacrum`
cc `@caass`
Detect blocks that could be struct expr bodies
This approach lives exclusively in the parser, so struct expr bodies
that are syntactically correct on their own but are otherwise incorrect
will still emit confusing errors, like in the following case:
```rust
fn foo() -> Foo {
bar: Vec::new()
}
```
```
error[E0425]: cannot find value `bar` in this scope
--> src/file.rs:5:5
|
5 | bar: Vec::new()
| ^^^ expecting a type here because of type ascription
error[E0214]: parenthesized type parameters may only be used with a `Fn` trait
--> src/file.rs:5:15
|
5 | bar: Vec::new()
| ^^^^^ only `Fn` traits may use parentheses
error[E0107]: wrong number of type arguments: expected 1, found 0
--> src/file.rs:5:10
|
5 | bar: Vec::new()
| ^^^^^^^^^^ expected 1 type argument
```
If that field had a trailing comma, that would be a parse error and it
would trigger the new, more targetted, error:
```
error: struct literal body without path
--> file.rs:4:17
|
4 | fn foo() -> Foo {
| _________________^
5 | | bar: Vec::new(),
6 | | }
| |_^
|
help: you might have forgotten to add the struct literal inside the block
|
4 | fn foo() -> Foo { Path {
5 | bar: Vec::new(),
6 | } }
|
```
Partially address last remaining part of #34255.
perf: UninhabitedEnumBranching avoid n^2
Avoid n² complexity. This showed up in a profile for match-stress-enum that has 8192 variants
I have only profiled locally against `match-stress-enum`, so we should have it perf tested to make sure it does not regress other crates.
The primary motivation is to get the changes from
https://github.com/tokio-rs/tracing/pull/990. Example output:
```
$ RUSTDOC_LOG=debug rustdoc +rustc2
warning: some trace filter directives would enable traces that are disabled statically
| `debug` would enable the DEBUG level for all targets
= note: the static max level is `info`
= help: to enable DEBUG logging, remove the `max_level_info` feature
```
- Remove useless test
This was testing for an ICE when passing `RUST_LOG=rustc_middle`. I
noticed it because it started giving the tracing warning (because tests
are not run with debug-logging enabled). Since this bug seems unlikely
to re-occur, I just removed it altogether.
Prevent stack overflow in deeply nested types.
Related issue #75577 (?)
Unfortunately, I am unable to test whether this actually solves the problem because apparently, 12GB RAM + 2GB swap is not enough to compile the (admittedly toy) source file.
This approach lives exclusively in the parser, so struct expr bodies
that are syntactically correct on their own but are otherwise incorrect
will still emit confusing errors, like in the following case:
```rust
fn foo() -> Foo {
bar: Vec::new()
}
```
```
error[E0425]: cannot find value `bar` in this scope
--> src/file.rs:5:5
|
5 | bar: Vec::new()
| ^^^ expecting a type here because of type ascription
error[E0214]: parenthesized type parameters may only be used with a `Fn` trait
--> src/file.rs:5:15
|
5 | bar: Vec::new()
| ^^^^^ only `Fn` traits may use parentheses
error[E0107]: wrong number of type arguments: expected 1, found 0
--> src/file.rs:5:10
|
5 | bar: Vec::new()
| ^^^^^^^^^^ expected 1 type argument
```
If that field had a trailing comma, that would be a parse error and it
would trigger the new, more targetted, error:
```
error: struct literal body without path
--> file.rs:4:17
|
4 | fn foo() -> Foo {
| _________________^
5 | | bar: Vec::new(),
6 | | }
| |_^
|
help: you might have forgotten to add the struct literal inside the block
|
4 | fn foo() -> Foo { Path {
5 | bar: Vec::new(),
6 | } }
|
```
Partially address last part of #34255.
Give `impl Trait` in a `const fn` its own feature gate
...previously it was gated under `#![feature(const_fn)]`.
I think we actually want to do this in all const-contexts? If so, this should be `#![feature(const_impl_trait)]` instead. I don't think there's any way to make use of `impl Trait` within a `const` initializer.
cc #77463
r? `@oli-obk`
Eliminate bounds checking in slice::Windows
This is how `<core::slice::Windows as Iterator>::next` looks right now:
```rust
fn next(&mut self) -> Option<&'a [T]> {
if self.size > self.v.len() {
None
} else {
let ret = Some(&self.v[..self.size]);
self.v = &self.v[1..];
ret
}
}
```
The line with `self.v = &self.v[1..];` relies on assumption that `self.v` is definitely not empty at this point. Else branch is taken when `self.size <= self.v.len()`, so `self.v` can be empty if `self.size` is zero. In practice, since `Windows` is never created directly but rather trough `[T]::windows` which panics when `size` is zero, `self.size` is never zero. However, the compiler doesn't know about this check, so it keeps the code which checks bounds and panics.
Using `NonZeroUsize` lets the compiler know about this invariant and reliably eliminate bounds checking without `unsafe` on `-O2`. Here is assembly of `Windows<'a, u32>::next` before and after this change ([goldbolt](https://godbolt.org/z/xrefzx)):
<details>
<summary>Before</summary>
```
example::next:
push rax
mov rcx, qword ptr [rdi + 8]
mov rdx, qword ptr [rdi + 16]
cmp rdx, rcx
jbe .LBB0_2
xor eax, eax
pop rcx
ret
.LBB0_2:
test rcx, rcx
je .LBB0_5
mov rax, qword ptr [rdi]
mov rsi, rax
add rsi, 4
add rcx, -1
mov qword ptr [rdi], rsi
mov qword ptr [rdi + 8], rcx
pop rcx
ret
.LBB0_5:
lea rdx, [rip + .L__unnamed_1]
mov edi, 1
xor esi, esi
call qword ptr [rip + core::slice::slice_index_order_fail@GOTPCREL]
ud2
.L__unnamed_2:
.ascii "./example.rs"
.L__unnamed_1:
.quad .L__unnamed_2
.asciz "\f\000\000\000\000\000\000\000\016\000\000\000\027\000\000"
```
</details>
<details>
<summary>After</summary>
```
example::next:
mov rcx, qword ptr [rdi + 8]
mov rdx, qword ptr [rdi + 16]
cmp rdx, rcx
jbe .LBB0_2
xor eax, eax
ret
.LBB0_2:
mov rax, qword ptr [rdi]
lea rsi, [rax + 4]
add rcx, -1
mov qword ptr [rdi], rsi
mov qword ptr [rdi + 8], rcx
ret
```
</details>
Note the lack of call to `core::slice::slice_index_order_fail` in second snippet.
#### Possible reasons _not_ to merge this PR:
* this changes the error message on panic in `[T]::windows`. However, AFAIK this messages are not covered by backwards compatibility policy.
resolve: improve "try using the enum's variant"
Fixes#73427.
This PR improves the "try using the enum's variant" suggestion:
- Variants in suggestions would not result in more errors (e.g. use of a struct variant is only suggested if the suggestion can trivially construct that variant). Therefore, suggestions are only emitted for variants that have no fields (since the suggestion can't know what value fields would have).
- Suggestions include the syntax for constructing the variant. If a struct or tuple variant is suggested, then it is constructed in the suggestion - unless in pattern-matching or when arguments are already provided.
- A help message is added which mentions the variants which are no longer suggested.
All of the diagnostic logic introduced by this PR is separated from the normal code path for a successful compilation.
r? `@estebank`
