Do not emit alloca for ZST locals with multiple assignments
This extends 35566bfd7d to additionally stop emitting unnecessary allocas for zero sized locals that are assigned multiple times.
When rebuilding the standard library with `-Zbuild-std` this reduces the number of locals that require an allocation from 62315 to 61767.
Rollup of 8 pull requests
Successful merges:
- #83739 (Account for bad placeholder errors on consts/statics with trait objects)
- #85637 (document PartialEq, PartialOrd, Ord requirements more explicitly)
- #86152 (Lazify is_really_default condition in the RustdocGUI bootstrap step)
- #86156 (Fix a bug in the linkchecker)
- #86427 (Updated release note)
- #86452 (fix panic-safety in specialized Zip::next_back)
- #86484 (Do not set depth to 0 in fully_expand_fragment)
- #86491 (expand: Move some more derive logic to rustc_builtin_macros)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Fix a bug in the linkchecker
There was a small typo in the linkchecker (in #85652) that caused it to report a `#` fragment link error pointing to the wrong file (it was displaying the path to the source file, not the target of the link).
This also includes a few other changes:
- Fixes the tests due to some changes in the redirect handling in #84703.
- Adds the tests to rustbuild to run whenever the linkchecker itself is run.
- Updates the tests to validate more of the output (so that a mistake like this would have been caught).
Closes#86144
Lazify is_really_default condition in the RustdocGUI bootstrap step
The `RustdocGUI::should_run` condition spawns `npm list` several times which adds up to seconds of wall-time.
Evaluate the condition lazily to to keep `./x.py test tidy` and similar short-running tasks fast.
Fixes#86147
BTree: encapsulate LeafRange better & some debug asserts
Looking at iterators again, I think #81937 didn't house enough code in `LeafRange`. Moving the API boundary a little makes things more local in navigate.rs and less complicated in map.rs.
r? `@Mark-Simulacrum`
Replace some `std::iter::repeat` with `str::repeat`
I noticed that there were some instances where `std::iter::repeat` would be used to repeat a string or a char to take a specific count of it and then collect it into a `String` when `str::repeat` is actually much faster and better for that.
See also: https://github.com/rust-lang/rust-clippy/issues/7260.
Change entry point to 🛡️ against 💥💥-payloads
Guard against panic payloads panicking within entrypoints, where it is
UB to do so.
Note that there are a number of tradeoffs to consider. For instance, I
considered guarding against accidental panics inside the `rt::init` and
`rt::cleanup` code as well, as it is not all that obvious these may not
panic, but doing so would mean that we initialize certain thread-local
slots unconditionally, which has its own problems.
Fixes#86030
r? `@m-ou-se`
Guard against panic payloads panicking within entrypoints, where it is
UB to do so.
Note that there are a number of implementation approaches to consider.
Some simpler, some more complicated. This particular solution is nice in
that it also guards against accidental implementation issues in
various pieces of runtime code, something we cannot prevent statically
right now.
Fixes#86030
Fix ICE with `#[repr(simd)]` on enum
This pull request fixes#83505. `#[repr(simd)]` may only be applied to structs, which correctly causes `E0517` for the example given in #83505, but the compiler attempts to recover from this error, which leads to an ICE later, when `.non_enum_variant()` is called on the `AdtDef`. I have added a check that prevents this from happening.
make UB during CTFE a hard error
This is a next step for https://github.com/rust-lang/rust/issues/71800. `const_err` has been a future-incompatibility lint for 4 months now since https://github.com/rust-lang/rust/pull/80394 (and err-by-default for many years before that), so I think we could try making it a proper hard error at least in some situations.
I didn't yet adjust the tests, since I first want to gauge the fall-out via crater.
Cc `@rust-lang/wg-const-eval`
Remove some last remants of {push,pop}_unsafe!
These macros have already been removed, but there was still some code handling these macros. That code is now removed.
Use `AttrVec` for `Arm`, `FieldDef`, and `Variant`
Uses `AttrVec` for `Arm`, `FieldDef`, and `Variant`, i.e., where the size of the vector can be empty often.
Skips `Crate` and `Item` because I think they may have the attributes on common cases and need more work outside of `rustc_ast` (e.g. rustc_expand needs a lot of tweaks). But if it's reasonable to change, I'm happy to do so.
Fixes#77662
Fix ICE when using `#[doc(keyword = "...")]` on non-items
This pull request fixes#83512. The code for checking attributes calls `expect_item()` when it shouldn't, thus causing an ICE. I have implemented a proper check for the node kind, so that an error is reported instead of the ICE.
Use better error message for hard errors in CTFE
I noticed this while working on #86255: currently the same message is used for hard errors and soft errors in CTFE. This changes the error messages to make hard errors use a message that indicates the reality of the situation correctly, since usage of the constant is never allowed when there was a hard error evaluating it. This doesn't affect the behaviour of these error messages, only the content.
This changes the error logic to check if the error should be hard or soft where it is generated, instead of where it is emitted, to allow this distinction in error messages.
Remove methods under Implementors on trait pages
As discussed at https://github.com/rust-lang/rust/issues/84326#issuecomment-842652412.
On a trait page, the "Implementors" section currently lists all methods of each implementor. That duplicates the method definitions on the trait itself, and is usually not very useful. So the implementors are collapsed by default. This PR changes rustdoc to just not render them at all. Any documentation specific to an implementor can be found by clicking through to the implementor's page.
This moves the "portability" info inside the `<summary>` tags so it is still visible on trait pages (as originally implemented in #79201). That also means it will be visible on struct/enum pages when methods are collapsed.
Add `#[doc(hidden)]` to all implementations of `Iterator::__iterator_get_unchecked` that didn't already have it. Otherwise, due to #86145, the structs/enums with those implementations would generate documentation for them, and that documentation would have a broken link into the Iterator page. Those links were already "broken" but not detected by the link-checker, because they pointed to one of the Implementors on the Iterator page, which happened to have the right anchor name.
This reduces the Read trait's page size from 128kB to 68kB (uncompressed) and from 12,125 bytes to 9,989 bytes (gzipped
Demo:
https://hoffman-andrews.com/rust/remove-methods-implementors/std/string/struct.String.html#trait-implementationshttps://hoffman-andrews.com/rust/remove-methods-implementors/std/io/trait.Read.html#implementors
r? `@GuillaumeGomez`
Replace parent substs of associated types with inference vars in borrow checker
Fixes https://github.com/rust-lang/rust/issues/83190
Fixes https://github.com/rust-lang/rust/issues/78450
When we normalize an associated type that refers to an opaque type, it can happen that the substs of the associated type do not occur in the projection (they are parent substs). We previously didn't replace those substs with inference vars, which left a concrete region after all regions should have already been replaced with inference vars and triggered a `delay_span_bug`. After we normalize the opaque type, we now try to replace any remaining concrete regions with inference vars.
Handle C-variadic arguments properly when reporting region errors
This pull request fixes#86053. The issue is that for a C-variadic function
```rust
#![feature(c_variadic)]
unsafe extern "C" fn foo(_: (), ...) {}
```
`foo`'s signature will contain only the first parameter (and have `c_variadic` set to `true`), whereas its body has a second argument (a `hir::Pat` for the `...`).
The code for reporting region errors iterates over the body's parameters and tries to fetch the corresponding parameter from the signature; this causes an out-of-bounds ICE for the `...` (though not in the example above, because there are no region errors to report).
I have simply restricted the iteration over the body parameters to exclude `...`, which is fine because `...` cannot cause a region error.
These were previously removed along with the details in the
"Implementors" section of trait pages. But for "Implementations on
Foreign Types," we need to include the details because they will not be
documented anywhere else.
