Some cleanup and improvement for invalid ref casting impl
This PR makes some cleanups and improvements to the `invalid_reference_casting` implementation in preparation for linting on new patterns, while reusing most of the logic.
r? `@est31` (feel free to re-assign)
rustdoc: allow resizing the sidebar / hiding the top bar
Fixes#97306
Preview: http://notriddle.com/rustdoc-html-demo-4/sidebar-resize/std/index.html
## Summary
This feature adds:
1. A checkbox to the Settings popover to hide the persistent navigation bar (the sidebar on large viewports and the top bar on small ones).
2. On large viewports, it adds a resize handle to the persistent sidebar. Resizing it into nothing is equivalent to turning off the persistent navigation bar checkbox in Settings.
3. If the navigation bar is hidden, a toolbar button to the left of the search appears. Clicking it brings the navigation bar back.
## Motivation
While "mobile mode" is definitely a good default, it's not the only reason people have wanted to hide the sidebar:
* Some people use tiling window managers, and don't like rustdoc's current breakpoints. Changing the breakpoints might help with that, but there's no perfect solution, because there's a gap between "huge screen" and "smartphone" where reasonable people can disagree about whether it makes sense for the sidebar to be on-screen. https://github.com/rust-lang/rust/issues/97306
* Some people ask for ways to reduce on-screen clutter because it makes it easier to focus. There's not a media query for that (and if there was, privacy-conscious users would turn it off). https://github.com/rust-lang/rust/issues/59829
This feature is designed to avoid these problems. Resizing the sidebar especially helps, because it provides a way to hide the sidebar without adding a new top-level button (which would add clutter), and it provides a way to make rustdoc play nicer in complex, custom screen layouts.
## Guide and Reference-level explanation
On a desktop or laptop with a mouse, resize the sidebar by dragging its right edge.
On any browser, including mobile phones, the sticky top bar or side bar can be hidden from the Settings area (the button with the cog wheel, next to the search bar). When it's hidden, a convenient button will appear on the search bar's left.
## Drawbacks
This adds more JavaScript code to the render blocking area.
## Rationale and alternatives
The most obvious way to allow people to hide the sidebar would have been to let them "manually enter mobile mode." The upside is that it's a feature we already have. The downside is that it's actually really hard to come up with a terse description. Is it:
* A Setting that forces desktop viewers to always have the mobile-style top bar? If so, how do we label it? Should it be visible on mobile, and, if so, does it just not do anything?
* A persistent hide/show sidebar button, present on desktop, just like on mobile? That's clutter that I'd like to avoid.
## Prior art
* The new file browser in GitHub uses a similar divider with a mouse-over indicator
* mdBook and macOS Finder both allow you to resize the sidebar to nothing as a gesture to hide it
* https://www.nngroup.com/articles/drag-drop/
## Future possibilities
https://rust-lang.zulipchat.com/#narrow/stream/266220-rustdoc/topic/Table.20of.20contents proposes a new, second sidebar (a table of contents). How should it fit in with this feature? Should it be resizeable? Hideable? Can it be accessed on mobile?
Don't merge cfg and doc(cfg) attributes for re-exports
Fixes#112881.
## Explanations
When re-exporting things with different `cfg`s there are two things that can happen:
* The re-export uses a subset of `cfg`s, this subset is sufficient so that the item will appear exactly with the subset
* The re-export uses a non-subset of `cfg`s (e.g. like the example I posted just above where the re-export is ungated), if the non-subset `cfg`s are active (e.g. compiling that example on windows) then this will be a compile error as the item doesn't exist to re-export, if the subset `cfg`s are active it behaves like 1.
### Glob re-exports?
**This only applies to non-glob inlined re-exports.** For glob re-exports the item may or may not exist to be re-exported (potentially the `cfg`s on the path up until the glob can be removed, and only `cfg`s on the globbed item itself matter), for non-inlined re-exports see https://github.com/rust-lang/rust/issues/85043.
cc `@Nemo157`
r? `@notriddle`
Opportunistically resolve region var in canonicalizer (instead of resolving root var)
See comment in `compiler/rustc_type_ir/src/infcx.rs`.
The **root** infer region for a given region vid may not actually be nameable from the universe of the original vid. That means that the assertion in the canonicalizer was too strict, since the `EagerResolver` that we use before canonicalizing is doing only as much resolving as it can.
This replaces `resolve_lt_var` and `probe_lt_var` in the `rustc_type_ir` API with `opportunistic_resolve_lt_var`, which acts as you expect it should. I left a FIXME that complains about the inconsistency.
This test is really gnarly, but I have no idea how to minimize it, since it seems to kind of just be coincidental that it triggered this issue. I hope the underlying root cause is easy enough to understand, though.
r? `@lcnr` or `@aliemjay`
Fixes#118950
Erase late bound regions from `Instance::fn_sig()` and add a few more details to StableMIR APIs
The Instance `fn_sig()` still included a late bound regions which needed a new compiler function in order to be erased. I've also bundled the following small fixes in this PR, let me know if you want me to isolate any of them.
- Add missing `CoroutineKind::AsyncGen`.
- Add optional spread argument to function body which is needed to properly analyze compiler shims.
- Add a utility method to iterate over all locals together with their declaration.
- Add a method to get the description of `AssertMessage`*.
* For the last one, we could consider eventually calling the internal `AssertKind::description()` to avoid code duplication. However, we still don't have ways to convert `AssertMessage`, `Operand`, `Place` and others, in order to use that. The other downside of using the internal method is that it will panic for some of the variants.
r ? `@ouz-a`
- Remove `fn_sig()` from Instance.
- Change return value of `AssertMessage::description` to `Cow<>`.
- Add assert to instance `ty()`.
- Generalize uint / int type creation.
Add all known `target_feature` configs to check-cfg
This PR adds all the known `target_feature` from ~~`rustc_codegen_ssa`~~ `rustc_target` to the well known list of check-cfg.
It does so by moving the list from `rustc_codegen_ssa` to `rustc_target` ~~`rustc_session` (I not sure about this, but some of the moved function take a `Session`)~~, then using it the `fill_well_known` function.
This already proved to be useful since portable-simd had a bad cfg.
cc `@nnethercote` (since we discussed it in https://github.com/rust-lang/rust/pull/118494)
Add -Zunpretty=stable-mir output test
As strongly suggested here https://github.com/rust-lang/rust/pull/118364#issuecomment-1827974148 this adds output test for `-Zunpretty=stable-mir`, added test shows almost all the functionality of the current printer.
r? `@compiler-errors`
fix dynamic size/align computation logic for packed types with dyn trait tail
This logic was never updated to support `packed(N)` where `N > 1`, and it turns out to be wrong for that case.
Fixes https://github.com/rust-lang/rust/issues/80925
`@bjorn3` I have not looked at cranelift; I assume it basically copied the size-of-val logic and hence could use much the same patch.
Enable stack probes on aarch64 for LLVM 18
I tested this on `aarch64-unknown-linux-gnu` with LLVM main (~18).
cc #77071, to be closed once we upgrade our LLVM submodule.
Tweak `short_ty_string` to reduce number of files
When shortening types and writing them to disk, make `short_ty_string` capable of reusing the same file, instead of writing a file per shortened type.
rustdoc-search: use set ops for ranking and filtering
This commit adds ranking and quick filtering to type-based search, improving performance and having it order results based on their type signatures.
Preview
-------
Profiler output: https://notriddle.com/rustdoc-html-demo-6/profile-8/index.html
Preview: https://notriddle.com/rustdoc-html-demo-6/ranking-and-filtering-v2/std/index.html
Motivation
----------
If I write a query like `str -> String`, a lot of functions come up. That's to be expected, but `String::from` should come up on top, and it doesn't right now. This is because the sorting algorithm is based on the functions name, and doesn't consider the type signature at all. `slice::join` even comes up above it!
To fix this, the sorting should take into account the function's signature, and the closer match should come up on top.
Guide-level description
-----------------------
When searching by type signature, types with a "closer" match will show up above types that match less precisely.
Reference-level explanation
---------------------------
Functions signature search works in three major phases:
* A compact "fingerprint," based on the [bloom filter] technique, is used to check for matches and to estimate the distance. It sometimes has false positive matches, but it also operates on 128 bit contiguous memory and requires no backtracking, so it performs a lot better than real unification.
The fingerprint represents the set of items in the type signature, but it does not represent nesting, and it ignores when the same item appears more than once.
The result is rejected if any query bits are absent in the function, or if the distance is higher than the current maximum and 200 results have already been found.
* The second step performs unification. This is where nesting and true bag semantics are taken into account, and it has no false positives. It uses a recursive, backtracking algorithm.
The result is rejected if any query elements are absent in the function.
[bloom filter]: https://en.wikipedia.org/wiki/Bloom_filter
Drawbacks
---------
This makes the code bigger.
More than that, this design is a subtle trade-off. It makes the cases I've tested against measurably faster, but it's not clear how well this extends to other crates with potentially more functions and fewer types.
The more complex things get, the more important it is to gather a good set of data to test with (this is arguably more important than the actual benchmarking ifrastructure right now).
Rationale and alternatives
--------------------------
Throwing a bloom filter in front makes it faster.
More than that, it tries to take a tactic where the system can not only check for potential matches, but also gets an accurate distance function without needing to do unification. That way it can skip unification even on items that have the needed elems, as long as they have more items than the currently found maximum.
If I didn't want to be able to cheaply do set operations on the fingerprint, a [cuckoo filter] is supposed to have better performance. But the nice bit-banging set intersection doesn't work AFAIK.
I also looked into [minhashing], but since it's actually an unbiased estimate of the similarity coefficient, I'm not sure how it could be used to skip unification (I wouldn't know if the estimate was too low or too high).
This function actually uses the number of distinct items as its "distance function." This should give the same results that it would have gotten from a Jaccard Distance $1-\frac{|F\cap{}Q|}{|F\cup{}Q|}$, while being cheaper to compute. This is because:
* The function $F$ must be a superset of the query $Q$, so their union is just $F$ and the intersection is $Q$ and it can be reduced to $1-\frac{|Q|}{|F|}.
* There are no magic thresholds. These values are only being used to compare against each other while sorting (and, if 200 results are found, to compare with the maximum match). This means we only care if one value is bigger than the other, not what it's actual value is, and since $Q$ is the same for everything, it can be safely left out, reducing the formula to $1-\frac{1}{|F|} = \frac{|F|}{|F|}-\frac{1}{|F|} = |F|-1$. And, since the values are only being compared with each other, $|F|$ is fine.
Prior art
---------
This is significantly different from how Hoogle does it.
It doesn't account for order, and it has no special account for nesting, though `Box<t>` is still two items, while `t` is only one.
This should give the same results that it would have gotten from a Jaccard Distance $1-\frac{|A\cap{}B|}{|A\cup{}B|}$, while being cheaper to compute.
Unresolved questions
--------------------
`[]` and `()`, the slice/array and tuple/union operators, are ignored while building the signature for the query. This is because they match more than one thing, making them ambiguous. Unfortunately, this also makes them a performance cliff. Is this likely to be a problem?
Right now, the system just stashes the type distance into the same field that levenshtein distance normally goes in. This means exact query matches show up on top (for example, if you have a function like `fn nothing(a: Nothing, b: i32)`, then searching for `nothing` will show it on top even if there's another function with `fn bar(x: Nothing)` that's technically a closer match in type signature.
Future possibilities
--------------------
It should be possible to adopt more sorting criteria to act as a tie breaker, which could be determined during unification.
[cuckoo filter]: https://en.wikipedia.org/wiki/Cuckoo_filter
[minhashing]: https://en.wikipedia.org/wiki/MinHash
Add more suggestions to unexpected cfg names and values
This pull request adds more suggestion to unexpected cfg names and values diagnostics:
- it first adds a links to the [rustc unstable book](https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html) or the [Cargo reference](https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg), depending if rustc is invoked by Cargo
- it secondly adds a suggestion on how to expect the cfg name or value:
*excluding well known names and values*
- for Cargo: it suggest using a feature or `cargo:rust-check-cfg` in build script
- for rustc: it suggest using `--check-cfg` (with the correct invocation)
Those diagnostics improvements are directed towards enabling users to fix the issue if the previous suggestions weren't good enough.
r? `@petrochenkov`
This commit adds ranking and quick filtering to type-based search,
improving performance and having it order results based on their
type signatures.
Motivation
----------
If I write a query like `str -> String`, a lot of functions come up.
That's to be expected, but `String::from_str` should come up on top, and
it doesn't right now. This is because the sorting algorithm is based
on the functions name, and doesn't consider the type signature at all.
`slice::join` even comes up above it!
To fix this, the sorting should take into account the function's
signature, and the closer match should come up on top.
Guide-level description
-----------------------
When searching by type signature, types with a "closer" match will
show up above types that match less precisely.
Reference-level explanation
---------------------------
Functions signature search works in three major phases:
* A compact "fingerprint," based on the [bloom filter] technique, is used to
check for matches and to estimate the distance. It sometimes has false
positive matches, but it also operates on 128 bit contiguous memory and
requires no backtracking, so it performs a lot better than real
unification.
The fingerprint represents the set of items in the type signature, but it
does not represent nesting, and it ignores when the same item appears more
than once.
The result is rejected if any query bits are absent in the function, or
if the distance is higher than the current maximum and 200
results have already been found.
* The second step performs unification. This is where nesting and true bag
semantics are taken into account, and it has no false positives. It uses a
recursive, backtracking algorithm.
The result is rejected if any query elements are absent in the function.
[bloom filter]: https://en.wikipedia.org/wiki/Bloom_filter
Drawbacks
---------
This makes the code bigger.
More than that, this design is a subtle trade-off. It makes the cases I've
tested against measurably faster, but it's not clear how well this extends
to other crates with potentially more functions and fewer types.
The more complex things get, the more important it is to gather a good set
of data to test with (this is arguably more important than the actual
benchmarking ifrastructure right now).
Rationale and alternatives
--------------------------
Throwing a bloom filter in front makes it faster.
More than that, it tries to take a tactic where the system can not only check
for potential matches, but also gets an accurate distance function without
needing to do unification. That way it can skip unification even on items
that have the needed elems, as long as they have more items than the
currently found maximum.
If I didn't want to be able to cheaply do set operations on the fingerprint,
a [cuckoo filter] is supposed to have better performance.
But the nice bit-banging set intersection doesn't work AFAIK.
I also looked into [minhashing], but since it's actually an unbiased
estimate of the similarity coefficient, I'm not sure how it could be used
to skip unification (I wouldn't know if the estimate was too low or
too high).
This function actually uses the number of distinct items as its
"distance function."
This should give the same results that it would have gotten from a Jaccard
Distance $1-\frac{|F\cap{}Q|}{|F\cup{}Q|}$, while being cheaper to compute.
This is because:
* The function $F$ must be a superset of the query $Q$, so their union is
just $F$ and the intersection is $Q$ and it can be reduced to
$1-\frac{|Q|}{|F|}.
* There are no magic thresholds. These values are only being used to
compare against each other while sorting (and, if 200 results are found,
to compare with the maximum match). This means we only care if one value
is bigger than the other, not what it's actual value is, and since $Q$ is
the same for everything, it can be safely left out, reducing the formula
to $1-\frac{1}{|F|} = \frac{|F|}{|F|}-\frac{1}{|F|} = |F|-1$. And, since
the values are only being compared with each other, $|F|$ is fine.
Prior art
---------
This is significantly different from how Hoogle does it.
It doesn't account for order, and it has no special account for nesting,
though `Box<t>` is still two items, while `t` is only one.
This should give the same results that it would have gotten from a Jaccard
Distance $1-\frac{|A\cap{}B|}{|A\cup{}B|}$, while being cheaper to compute.
Unresolved questions
--------------------
`[]` and `()`, the slice/array and tuple/union operators, are ignored while
building the signature for the query. This is because they match more than
one thing, making them ambiguous. Unfortunately, this also makes them
a performance cliff. Is this likely to be a problem?
Right now, the system just stashes the type distance into the
same field that levenshtein distance normally goes in. This means exact
query matches show up on top (for example, if you have a function like
`fn nothing(a: Nothing, b: i32)`, then searching for `nothing` will show it
on top even if there's another function with `fn bar(x: Nothing)` that's
technically a closer match in type signature.
Future possibilities
--------------------
It should be possible to adopt more sorting criteria to act as a tie breaker,
which could be determined during unification.
[cuckoo filter]: https://en.wikipedia.org/wiki/Cuckoo_filter
[minhashing]: https://en.wikipedia.org/wiki/MinHash
Coroutine variant fields can be uninitialized
Wrap coroutine variant fields in MaybeUninit to indicate that they might be uninitialized. Otherwise an uninhabited field will make the entire variant uninhabited and introduce undefined behaviour.
The analogous issue in the prefix of coroutine layout was addressed by 6fae7f8071.
Support bare unit structs in destructuring assignments
We should be allowed to use destructuring assignments on *bare* unit structs, not just unit structs that are located within other pattern constructors.
Fixes#118753
r? petrochenkov since you reviewed #95380, reassign if you're busy or don't want to review this.
codegen: panic when trying to compute size/align of extern type
The alignment is also computed when accessing a field of extern type at non-zero offset, so we also panic in that case.
Previously `size_of_val` worked because the code path there assumed that "thin pointer" means "sized". But that's not true any more with extern types. The returned size and align are just blatantly wrong, so it seems better to panic than returning wrong results. We use a non-unwinding panic since code probably does not expect size_of_val to panic.
[`RFC 3086`] Attempt to try to resolve blocking concerns
Implements what is described at https://github.com/rust-lang/rust/issues/83527#issuecomment-1744822345 to hopefully make some progress.
It is unknown if such approach is or isn't desired due to the lack of further feedback, as such, it is probably best to nominate this PR to the official entities.
`@rustbot` labels +I-compiler-nominated
Actually parse async gen blocks correctly
1. I got the control flow in `parse_expr_bottom` messed up, and obviously forgot a test for `async gen`, so we weren't actually ever parsing it correctly.
2. I forgot to gate the span for `async gen {}`, so even if we did parse it, we wouldn't have correctly denied it in `cfg(FALSE)`.
r? eholk
Add rustX check to codeblock attributes lint
We discovered this issue [here](https://github.com/rust-lang/rust/pull/118802#discussion_r1421815943).
I assume that the issue will be present in other places outside of the compiler so it's worth adding a check for it.
First commit is just a small cleanup about variables creation which was a bit strange (at least more than necessary).
r? ```@notriddle```
Fix alignment passed down to LLVM for simd_masked_load
Follow up to #117953
The alignment for a masked load operation should be that of the element/lane, not the vector as a whole
It can produce miscompilations after the LLVM optimizer notices the higher alignment and promotes this to an unmasked, aligned load followed up by blend/select - https://rust.godbolt.org/z/KEeGbevbb
tests: CGU tests require build-pass, not check-pass (remove FIXME)
CGU tests require CGU code to be exercised. We can't merely do "cargo check" on these tests.
Part of #62277
Correctly gate the parsing of match arms without body
https://github.com/rust-lang/rust/pull/118527 accidentally allowed the following to parse on stable:
```rust
match Some(0) {
None => { foo(); }
#[cfg(FALSE)]
Some(_)
}
```
This fixes that oversight. The way I choose which error to emit is the best I could think of, I'm open if you know a better way.
r? `@petrochenkov` since you're the one who noticed
Improve an error involving attribute values.
Attribute values must be literals. The error you get when that doesn't hold is pretty bad, e.g.:
```
unexpected expression: 1 + 1
```
You also get the same error if the attribute value is a literal, but an invalid literal, e.g.:
```
unexpected expression: "foo"suffix
```
This commit does two things.
- Changes the error message to "attribute value must be a literal", which gives a better idea of what the problem is and how to fix it. It also no longer prints the invalid expression, because the carets below highlight it anyway.
- Separates the "not a literal" case from the "invalid literal" case. Which means invalid literals now get the specific error at the literal level, rather than at the attribute level.
r? `@compiler-errors`
On borrow return type, suggest borrowing from arg or owned return type
When we encounter a function with a return type that has an anonymous lifetime with no argument to borrow from, besides suggesting the `'static` lifetime we now also suggest changing the arguments to be borrows or changing the return type to be an owned type.
```
error[E0106]: missing lifetime specifier
--> $DIR/variadic-ffi-6.rs:7:6
|
LL | ) -> &usize {
| ^ expected named lifetime parameter
|
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
LL | ) -> &'static usize {
| +++++++
help: instead, you are more likely to want to change one of the arguments to be borrowed...
|
LL | x: &usize,
| +
help: ...or alternatively, to want to return an owned value
|
LL - ) -> &usize {
LL + ) -> usize {
|
```
Fix#85843.
dont ICE when ConstKind::Expr for is_const_evaluatable
The problem is that we are not handling ConstKind::Expr inside report_not_const_evaluatable_error
Fixes [#114151]
