debuginfo: Generalize C++-like encoding for enums.
The updated encoding should be able to handle niche layouts where more than one variant has fields (as introduced in https://github.com/rust-lang/rust/pull/94075).
The new encoding is more uniform as there is no structural difference between direct-tag, niche-tag, and no-tag layouts anymore. The only difference between those cases is that the "dataful" variant in a niche-tag enum will have a `(start, end)` pair denoting the tag range instead of a single value.
The new encoding now also supports 128-bit tags, which occur in at least some standard library types. These tags are represented as `u64` pairs so that debuggers (which don't always have support for 128-bit integers) can reliably deal with them. The downside is that this adds quite a bit of complexity to the encoding and especially to the corresponding NatVis.
The new encoding seems to increase the size of (x86_64-pc-windows-msvc) debuginfo by 10-15%. The size of binaries is not affected (release builds were built with `-Cdebuginfo=2`, numbers are in kilobytes):
EXE | before | after | relative
-- | -- | -- | --
cargo (debug) | 40453 | 40450 | +0%
ripgrep (debug) | 10275 | 10273 | +0%
cargo (release) | 16186 | 16185 | +0%
ripgrep (release) | 4727 | 4726 | +0%
PDB | before | after | relative
-- | -- | -- | --
cargo (debug) | 236524 | 261412 | +11%
ripgrep (debug) | 53140 | 59060 | +11%
cargo (release) | 148516 | 169620 | +14%
ripgrep (release) | 10676 | 11804 | +11%
Given that the new encoding is more general, this is to be expected. Only platforms using C++-like debuginfo are affected -- which currently is only `*-pc-windows-msvc`.
*TODO*
- [x] Properly update documentation
- [x] Add regression tests for new optimized enum layouts as introduced by #94075.
r? `@wesleywiser`
Visit attributes in more places.
This adds 3 loosely related changes (I can split PRs if desired):
- Attribute checking on pattern struct fields.
- Attribute checking on struct expression fields.
- Lint level visiting on pattern struct fields, struct expression fields, and generic parameters.
There are still some lints which ignore lint levels in various positions. This is a consequence of how the lints themselves are implemented. For example, lint levels on associated consts don't work with `unused_braces`.
fix(iter::skip): Optimize `next` and `nth` implementations of `Skip`
This avoids calling nth/next or nth/nth to first skip elements and then get the next one (unless necessary due to usize overflow).
Rollup of 6 pull requests
Successful merges:
- #100249 (Fix HorizonOS regression in FileTimes)
- #100253 (Recover from mutable variable declaration where `mut` is placed before `let`)
- #100482 (Add Duration rounding change to release note)
- #100523 ([rustdoc] remove Clean trait)
- #100524 (Impl `Debug` for some structs of rustbuild)
- #100526 (Add tests for the drop behavior of some control flow constructs)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add tests for the drop behavior of some control flow constructs
In #100513 it was shown that the drop behaviour of let_chains is not correct currently. Since drop behaviour is something pretty subtle, this adds explicit tests for the drop behavior of `if`, `if let` and `match` to make sure that it does not regress in the future.
The `println!`s were left in to make debugging easier in case something goes wrong, but they are not required for the test.
Impl `Debug` for some structs of rustbuild
A small patch to impl `Debug` for some structs of rustbuild to make debugging easier.
(I was trying to impl `Debug` for the `Config` struct, but found to have a bit more things to do. So gave up for now.)
Fix HorizonOS regression in FileTimes
The changes in #98246 caused a regression for multiple Newlib-based systems. This is just a fix including HorizonOS to the list of targets which require a workaround.
``@AzureMarker`` ``@ian-h-chamberlain``
r? ``@nagisa``
rustdoc: Merge source code pages HTML elements together
We realized that the HTML generated for the source code pages could be improved quite a lot. This PR is a first pass toward this goal. Some explanations: it merges similar classes elements (even when there are white characters in between).
There is an exception to this: if this is an ident, I also merged it with "unclassified" elements. This part is up to debate and can be very easily removed as the check is performed in one place (in the `can_merge` function).
EDIT: The `ident` is now only kept in the code for the `span` it contains but it is not rendered into the HTML.
So now some numbers:
For these ones, on each page, I run this JS: `document.getElementsByTagName('*').length`. The goal is to count the number of DOM elements. I took some pages that seemed big, but don't hesitate to check some others.
| file name | before this PR | with this PR | diff | without ident | diff |
|-|-|-|-|-|-|
| std/lib.rs.html (source link on std crate page) | 3455 | 2776 | 20.7% | 2387 | 31% |
| alloc/vec/mod.rs.html (source on Vec type page) | 11012 | 8084 | 26.6% | 6682 | 39.4% |
| alloc/string.rs.html (source on String type page) | 10800 | 8214 | 24% | 6712 | 37.9% |
| std/sync/mutex.rs.html (source on Mutex type page) | 2953 | 2403 | 18.7% | 2139 | 27.6% |
You can test it [here](https://rustdoc.crud.net/imperio/merge-html-elements-together/src/std/lib.rs.html).
cc `@jsha`
r? `@notriddle`
In #100513 it was shown that the drop behavior of let_chains is not correct
currently. Since drop behavior is something pretty subtle, this adds
explicit tests for the drop behavior of `if`, `if let` and `match` to
make sure that it does not regress in the future.
The `println!`s were left in to make debugging easier in case something
goes wrong, but they are not required for the test.
rustc_target: Update some old naming around self contained linking
The "fallback" naming pre-dates introduction of `-Clink-self-contained`.
Noticed when reviewing https://github.com/rust-lang/rust/pull/99500.
This PR doesn't break any json target spec, but supporting per-linker-flavor startup objects needed by https://github.com/rust-lang/rust/pull/99500 will break them, so maybe next time I'll remove the compatibility names.
Add `Iterator::array_chunks` (take N+1)
A revival of https://github.com/rust-lang/rust/pull/92393.
r? `@Mark-Simulacrum`
cc `@rossmacarthur` `@scottmcm` `@the8472`
I've tried to address most of the review comments on the previous attempt. The only thing I didn't address is `try_fold` implementation, I've left the "custom" one for now, not sure what exactly should it use.
orphan check: rationalize our handling of constants
cc `@rust-lang/types` `@rust-lang/project-const-generics` on whether you agree with this reasoning.
r? types
Rollup of 8 pull requests
Successful merges:
- #99646 (Only point out a single function parameter if we have a single arg incompatibility)
- #100299 (make `clean::Item::span` return `Option` instead of dummy span)
- #100335 (Rustdoc-Json: Add `Path` type for traits.)
- #100367 (Suggest the path separator when a dot is used on a trait)
- #100431 (Enum variant ctor inherits the stability of the enum variant)
- #100446 (Suggest removing a semicolon after impl/trait items)
- #100468 (Use an extensionless `x` script for non-Windows)
- #100479 (Argument type error improvements)
Failed merges:
- #100483 (Point to generic or arg if it's the self type of unsatisfied projection predicate)
r? `@ghost`
`@rustbot` modify labels: rollup
Argument type error improvements
Motivated by this interesting code snippet:
```rust
#[derive(Copy, Clone)]
struct Wrapper<T>(T);
fn foo(_: fn(i32), _: Wrapper<i32>) {}
fn f(_: u32) {}
fn main() {
let w = Wrapper::<isize>(1isize);
foo(f, w);
}
```
Which currently errors like:
```
error[E0308]: arguments to this function are incorrect
--> src/main.rs:10:5
|
10 | foo(f, w);
| ^^^ - - expected `i32`, found `isize`
| |
| expected `i32`, found `u32`
|
= note: expected fn pointer `fn(i32)`
found fn item `fn(u32) {f}`
= note: expected struct `Wrapper<i32>`
found struct `Wrapper<isize>`
note: function defined here
--> src/main.rs:4:4
|
4 | fn foo(_: fn(i32), _: Wrapper<i32>) {}
| ^^^ ---------- ---------------
```
Specifically, that double `expected .. found ..` which is very difficult to correlate to the types in the arguments. Also, the fact that "expected `i32`, found `isize`" and the other argument mismatch label don't even really explain what's going on here.
After this PR:
```
error[E0308]: arguments to this function are incorrect
--> $DIR/two-mismatch-notes.rs:10:5
|
LL | foo(f, w);
| ^^^
|
note: expected fn pointer, found fn item
--> $DIR/two-mismatch-notes.rs:10:9
|
LL | foo(f, w);
| ^
= note: expected fn pointer `fn(i32)`
found fn item `fn(u32) {f}`
note: expected struct `Wrapper`, found a different struct `Wrapper`
--> $DIR/two-mismatch-notes.rs:10:12
|
LL | foo(f, w);
| ^
= note: expected struct `Wrapper<i32>`
found struct `Wrapper<isize>`
note: function defined here
--> $DIR/two-mismatch-notes.rs:4:4
|
LL | fn foo(_: fn(i32), _: Wrapper<i32>) {}
| ^^^ ---------- ---------------
error: aborting due to previous error
For more information about this error, try `rustc --explain E0308`.
```
Yeah, it's a bit verbose, but much clearer IMO.
---
Open to discussions about how this could be further improved. Motivated by `@jyn514's` [tweet](https://mobile.twitter.com/joshuayn514/status/1558042020601634816) here.
Use an extensionless `x` script for non-Windows
#99992 added `x.sh` and `x.ps1`, but this broke my lazy `./xTAB` habit that used to get me to `./x.py`. If we rename `x.sh` to `x`, then I can adjust to `./xSPACE` for the same number of characters typed.
r? `@jyn514`
Rustdoc-Json: Add `Path` type for traits.
Avoids using `Type` for trait fields, as a trait must always be a path, and not any other kind of type.
``@rustbot`` modify labels: +A-rustdoc-json +T-rustdoc
Closes#100106
Rollup of 11 pull requests
Successful merges:
- #100355 (rustdoc: Rename ``@has` FILE PATTERN` to ``@hasraw` FILE PATTERN`)
- #100407 (avoid some int2ptr casts in thread_local_key tests)
- #100434 (Fix HIR pretty printing of let else)
- #100438 (Erase regions better in `promote_candidate`)
- #100445 (adapt test for msan message change)
- #100447 (Remove more Clean trait implementations)
- #100464 (Make `[rust] use-lld=true` work on windows)
- #100475 (Give a helpful diagnostic when the next struct field has an attribute)
- #100490 (wf: correctly `shallow_resolve` consts)
- #100501 (nicer Miri backtraces for from_exposed_addr)
- #100509 (merge two test directories that mean the same thing)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
wf: correctly `shallow_resolve` consts
`shallow_resolve` on `InferConst` is always a noop. this is mostly irrelevant as inference vars should already be resolved at most - if not all - call sites. Haven't actually looked too deeply into whether this was a problem.
Erase regions better in `promote_candidate`
Use `tcx.erase_regions` instead of manually walking through the substs.... this also makes the code slightly simpler 🙈Fixes#100360Fixes#89851
