const fn integer operations
A follow up to #51171Fixes#51267
Makes a lot of the integer methods (`swap_bytes`, `count_ones` etc) `const fn`s. See #51267 for a discussion about why this is wanted and the solution used.
Rollup of 6 pull requests
Successful merges:
- #51143 (Specify that packed types must derive, not implement, Copy)
- #51226 (Make Layout's align a NonZeroUsize)
- #51297 (Fix run button style)
- #51306 (impl Default for &mut str)
- #51312 (Clarify the difference between get_mut and into_mut for OccupiedEntry)
- #51313 (use type name in E0599 enum variant suggestion)
Failed merges:
Fix building rustc on and for musl hosts.
This fixes all problems I had when trying to compile rustc on a musl-based distribution (with `crt-static = false` in `config.toml`).
This is a fixed version of what ended up being #50105, making it possible to compile rustc on musl targets.
The differences to the old (now merged and subsequently reverted) pull request are:
- The commit (6d9154a830) that caused the regression for which the original commits were reverted in #50709 is left out. This means the corresponding bug #36710 is still not fixed with `+crt-static`.
- The test for issue 36710 is skipped for musl targets (until the issue is properly fixed).
- Building cargo-vendor if `crt-static = false` is needed was broken (cargo-vendor links to some shared libraries if they exist on the system and this produces broken binaries with `+crt-static`)
CC @alexcrichton
merge unused-extern-crate and unnecessary-extern-crate lints
Extend the `unused_extern_crates` lint to offer a suggestion to remove the extern crate and remove the `unnecessary_extern_crate` lint.
Still a few minor issues to fix:
- [x] this *does* now leave a blank line... (defer to https://github.com/rust-lang/rust/issues/51176)
- idea: extend the span to be replaced by 1 character if the next character is a `\n`
- [x] what about macros? do we need to watch out for that? (defer to https://github.com/rust-lang/rust/issues/48704)
- [x] also it doesn't work for `extern crate foo; fn main() { foo::bar(); }`
- this is subtle: the `foo` might be shadowing a glob import too, can't always remove
- defer to https://github.com/rust-lang/rust/issues/51177
- [x] we also don't do the `pub use` rewrite thang (https://github.com/rust-lang/rust/issues/51013)
Spun off from https://github.com/rust-lang/rust/pull/51010Fixes#50672
r? @alexcrichton
Tweak output on E0599 for assoc fn used as method
- Use suggestion instead of `help` when possible
- Add primary span label
- Remove incorrect `help` suggestion using incorrect syntax
- Do not refer to only one possible candidate as `candidate #1`, refer to it as `the candidate`
Make some std::intrinsics `const fn`s
Making some rustc intrinsics (`ctpop`, `cttz`, `ctlz` and `bswap`) `const fn`s.
This is a pre-step to being able to make `swap_bytes`, `to_be` and `from_be` constant functions. That in itself could be ergonomic and useful. But even better is that it would allow `Ipv4Addr::new` etc becoming `const fn`s as well. Which might be really useful since I find it quite common to want to define them as constants.
r? @oli-obk
Register outlives predicates from queries the right way around.
Closes#49354
The region constraints from queries need to be reversed from sub to outlives.
Note: wf checking reports these errors before NLL, so I'm not sure if there's any case when these predicates need to be created at all.
cc @nikomatsakis
remove notion of Implicit derefs from mem-cat
`PointerKind` is included in `LoanPath` and hence forms part of the equality check; this led to having two unequal paths that both represent `*x`, depending on whether the `*` was inserted automatically or explicitly. Bad mojo.
Fixes#51117
r? @eddyb
`PointerKind` is included in `LoanPath` and hence forms part of the
equality check; this led to having two unequal paths that both
represent `*x`, depending on whether the `*` was inserted
automatically or explicitly. Bad mojo. The `note` field, in contrast,
is intended more-or-less primarily for this purpose of adding extra
data.
[MIR] Change "scopes" from "visibility scopes" to "source scopes".
These scopes are already used for source-oriented diagnostics, lint levels and unsafety checks.
This PR generalizes the naming around scopes, making the type `SourceScope`, and flips (across several commits) the relationship/priority between `LocalDecl`'s "visibility" and "syntactic" scopes.
r? @nikomatsakis
reset anonymous-lifetime-mode as we enter `()` scopes
Background:
The anonymous lifetime mode is used to prohibit elided lifetimes where
they didn't used to be permitted, and instead require that `'_` be
used. For example:
```rust
impl Trait for Ref<T> { .. }
// ^^^^^^ ERROR: should be `Ref<'_, T>`
```
When we are parsing the parts of the impl header, we enter into an alternate mode called `CreateParameter`. In this mode, we give an error for things like `Ref<T>`, but for elided lifetimes in a reference type like `&T` we make the elided lifetime into an in-band lifetime:
4f99f37b7e/src/librustc/hir/lowering.rs (L4017-L4035)
This was not intended to change behavior because we only enter into that mode in contexts where elision was not historically permitted. However, the problem is that we fail to reset the mode when we enter into bounds like `Fn(&u32)`, where elision *was* allowed -- the same occurs for fn types like `fn(&u32`). This PR restores the original mode in those contexts.
Fixes#51008
r? @cramertj
rustc: don't visit lifetime parameters through visit_lifetime.
Ideally we'd also not use the `Lifetime` struct for parameters, but I'll leave that to @varkor (#48149).
Fixes#51185 (discovered while auditing all the `visit_lifetime` implementations).
r? @nikomatsakis
