It doesn't add anything since every topic in
`t-compiler/wg-prioritization/alerts` is about prioritization.
And it makes it harder to see the issue title, which is what the topic
is actually about.
When normalizing a projection which results in a cycle, we would
cache the result of `project_type` without the nested obligations
(because they're not needed for inference). This would result in
the nested obligations only being handled once in fulfill, which
would avoid the cycle error.
Fixes#79714, a regresion from #79305 caused by the removal of
`get_paranoid_cache_value_obligation`.
This function was unfortunate for several reasons:
- It used `unsafe` because it wanted to tell whether a string came from
the same *allocation* as another, not just whether it was a textual
match.
- It recalculated spans even though they were already available from
pulldown
- It sometimes *failed* to calculate the span, which meant it was always
possible for the span to be `None`, even though in practice that
should never happen.
This commit has several cleanups:
- Make the span required
- Pass through the span from pulldown in the `HeadingLinks` and
`Footnotes` iterators
- Only add iterator bounds on the `impl Iterator`, not on `new` and the
struct itself.
Turn quadratic time on number of impl blocks into linear time
Previously, if you had a lot of inherent impl blocks on a type like:
```Rust
struct Foo;
impl Foo { fn foo_1() {} }
// ...
impl Foo { fn foo_100_000() {} }
```
The compiler would be very slow at processing it, because
an internal algorithm would run in O(n^2), where n is the number
of impl blocks. Now, we add a new algorithm that allocates but
is faster asymptotically.
Comparing rustc nightly with a local build of rustc as of this PR (results in seconds):
| N | real time before | real time after |
| - | - | - |
| 4_000 | 0.57 | 0.46 |
| 8_000 | 1.31 | 0.84 |
| 16_000 | 3.56 | 1.69 |
| 32_000 | 10.60 | 3.73 |
I've tuned up the numbers to make the effect larger than the startup noise of rustc, but the asymptotic difference should hold for smaller n as well.
Note: current state of the PR omits error messages if there are other errors present already. For now, I'm mainly interested in a perf run to study whether this issue is present at all. Please queue one for this PR. Thanks!
Re-word doc comment for rustc_middle::hir::place::Projection.
Also adds:
- Missing end stop punctuation, and
- Documentation links to `rustc_middle::mir::Place`.
Mark `-1` as an available niche for file descriptors
Based on discussion from <https://internals.rust-lang.org/t/can-the-standard-library-shrink-option-file/12768>, the file descriptor `-1` is chosen based on the POSIX API designs that use it as a sentinel to report errors. A bigger niche could've been chosen, particularly on Linux, but would not necessarily be portable.
This PR also adds a test case to ensure that the -1 niche (which is kind of hacky and has no obvious test case) works correctly. It requires the "upper" bound, which is actually -1, to be expressed in two's complement.
Skip `dsymutil` by default for compiler bootstrap
`dsymutil` adds time to builds on Apple platforms for no clear benefit, and also makes it more difficult for debuggers to find debug info (which `@pnkfelix` highlighted on [Zulip](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/does.20lldb.20%28or.20gdb%29.20work.20on.20rustc.20on.20Mac.3F/near/220482092)). The compiler currently defaults to running `dsymutil` to preserve its historical default, but when compiling the compiler itself, we skip it by default since we know it's safe to do so in that case.
r? `@nagisa`
`PatKind::Ref(PatKind::Ident(BindingMode::ByValue(Mutability::Mut), ..), ..)`
is an AST representing `&(mut ident)`. It was errorneously printed as
`&mut ident` which reparsed into a syntactically different AST.
This affected help diagnostics in the parser.
Fix memory leak in test "mem::uninit_write_slice_cloned_no_drop"
This fixes#80116. I replaced the `Rc` based method I was using with a type that panics when dropped.
Make BoundRegion have a kind of BoungRegionKind
Split from #76814
Also includes making `replace_escaping_bound_vars` only return `T`
Going to r? `@lcnr`
Feel free to reassign
or_patterns: implement :pat edition-specific behavior
cc #54883 `@joshtriplett`
This PR implements the edition-specific behavior of `:pat` wrt or-patterns, as determined by the crater runs and T-lang consensus in https://github.com/rust-lang/rust/issues/54883#issuecomment-745509090.
I believe this can unblock stabilization of or_patterns.
r? `@petrochenkov`
`dsymutil` adds time to builds on Apple platforms for no clear benefit, and also
makes it more difficult for debuggers to find debug info. The compiler currently
defaults to running `dsymutil` to preserve its historical default, but when
compiling the compiler itself, we skip it by default since we know it's safe to
do so in that case.
