Optimize matches
Attempt to fix or improve #60571
This is breaking some diagnostics because the MIR for match arms isn't in source order any more.
cc @centril
Remove some unnecessary symbol interner ops
* Don't gensym symbols that don't need to worry about colliding with other symbols
* Use symbol constants instead of interning string literals in a few places.
* Don't generate a module in `__register_diagnostic`
r? @petrochenkov
Allow attributes in formal function parameters
Implements https://github.com/rust-lang/rust/issues/60406.
This is my first contribution to the compiler and since this is a large and complex project, I am not fully aware of the consequences of the changes I have made.
**TODO**
- [x] Forbid some built-in attributes.
- [x] Expand cfg/cfg_attr
Use Symbol, Span in libfmt_macros
I'm not super happy with this, personally, but I think it might be a decent start -- happy to take suggestions as to how to expand this or change things further.
r? @estebank
Fixes#60795
Add deny(unused_lifetimes) to all the crates that have deny(internal).
@Zoxc brought up, regarding #61722, that we don't force the removal of unused lifetimes.
Turns out that it's not that bad to enable for compiler crates (I wonder why it's not `warn` by default?).
I would've liked to enable `single_use_lifetimes` as well, but https://github.com/rust-lang/rust/issues/53738 makes it unusable for now.
For the `rustfmt` commit, I used https://github.com/rust-lang/rustfmt/issues/1324#issuecomment-482109952, and manually filtered out some noise.
r? @oli-obk cc @rust-lang/compiler
This should be used when trying to get at subsets of a larger span,
especially when the larger span is not available in the code attempting
to work with those subsets (especially common in the fmt_macros crate).
This is usually a good replacement for (BytePos, BytePos) and (usize,
usize) tuples.
This commit also removes from_inner_byte_pos, since it took usize
arguments, which is error prone.
Make tuple constructors real const fns
Mir construction special cases `Ctor(...)` to be lowered as `Ctor { 0: ... }`, which means this doesn't come up much in practice, but it seems inconsistent not to allow this.
r? @oli-obk
They can each now do a single `HygieneData::with` call by replacing the
`SyntaxContext` and `Mark` methods with the equivalent methods from
`HygieneData`.
Simplify use of keyword symbols
They mirror non-keyword symbols now (see https://github.com/rust-lang/rust/pull/60630).
`keywords::MyKeyword.name()` -> `kw::MyKeyword`
`keywords::MyKeyword.ident()` -> `Ident::with_empty_ctxt(kw::MyKeyword)` (not common)
`keywords::Invalid.ident()` -> `Ident::invalid()` (more common)
Keywords are simply `Symbol` constants now, the `Keyword` struct is eliminated.
This means `kw::MyKeyword` can now be used in `match` in particular.
