compiler: rename BareFn to FnPtr
At some point "BareFn" was the chosen name for a "bare" function, without the niceties of `~fn`, `&fn`, or a few other ways of writing a function type. However, at some point the syntax for a "bare function" and any other function diverged even more. We started calling them what they are: function pointers, denoted by their own syntax.
However, we never changed the *internal* name for these, as this divergence was very gradual. Personally, I have repeatedly searched for "FnPtr" and gotten confused until I find the name is BareFn, only to forget this until the next time, since I don't routinely interact with the higher-level AST and HIR. But even tools that interact with these internal types only touch on them in a few places, making a migration easy enough. Let's use a more intuitive and obvious name, as this 12+ year old name has little to do with current Rust.
mbe: Change `unused_macro_rules` to a `DenseBitSet`
Now that it only contains indexes, and no other information, a bitset provides a more compact and simpler representation.
This builds on <https://github.com/rust-lang/rust/pull/143416>. Only the last commit is new.
Align attr fixes
- Remove references to the superseded `repr(align)` syntax
- Allow the attribute on fn items in `extern` blocks
- Test attribute in combination with `async fn` and `dyn`
r? workingjubilee
Tracking issue: https://github.com/rust-lang/rust/issues/82232
`@rustbot` label A-attributes F-fn_align T-compiler
Fix some comments and related types and locals where it is obvious, e.g.
- bare_fn -> fn_ptr
- LifetimeBinderKind::BareFnType -> LifetimeBinderKind::FnPtrType
Co-authored-by: León Orell Valerian Liehr <me@fmease.dev>
Do not unify borrowed locals in CopyProp.
Instead of trying yet another scheme to unify borrowed locals in CopyProp, let's just stop trying. We had already enough miscompilations because of this.
I'm convinced it's possible to have both unification of some borrowed locals and soundness, but I don't have a simple and convincing formulation yet.
Fixes https://github.com/rust-lang/rust/issues/143491
rustc_builtin_macros: Make sure registered attributes stay sorted
As with the list of builtin macros, use tidy to make sure the list of
builtin attributes stays sorted.
As part of this reorganization, some traits need to be moved from `rustc_smir::context::traits` to `stable_mir::unstable::internal_cx`. These traits are specifically designed for `InternalCx` to clarify the behavior of different functions that share the same name. This move is necessary to avoid orphan rule violations.
use `is_multiple_of` and `div_ceil`
In tricky logic, these functions are much more informative than the manual implementations. They also catch subtle bugs:
- the manual `is_multiple_of` often does not handle division by zero
- manual `div_ceil` often does not consider overflow
The transformation is free for `is_multiple_of` if the divisor is compile-time known to be non-zero. For `div_ceil` there is a small cost to considering overflow. Here is some assembly https://godbolt.org/z/5zP8KaE1d.
mbe: Defer checks for `compile_error!` until reporting an unused macro rule
The current MBE parser checks rules at initial parse time to see if their RHS has `compile_error!` in it, and returns a list of rule indexes and LHS spans that don't map to `compile_error!`, for use in unused macro rule checking.
Instead, have the unused macro rule reporting ask the macro for the rule to report, and let the macro check at that time. That avoids checking rules unless they're unused.
In the process, refactor the data structure used to store macro rules, to group the LHS and RHS (and LHS span) of each rule together, and refactor the unused rule tracking to only track rule indexes.
This builds atop a couple of minor MBE refactors. I would suggest reviewing commit-by-commit.
The overall result is a further simplification of the macro code.
The MBE parser checks rules at initial parse time to see if their RHS
has `compile_error!` in it, and returns a list of rule indexes and LHS
spans that don't map to `compile_error!`, for use in unused macro rule
checking.
Instead, have the unused macro rule reporting ask the macro for the rule
to report, and let the macro check at that time. That avoids checking
rules unless they're unused.
In the process, refactor the data structure used to store macro rules,
to group the LHS and RHS (and LHS span) of each rule together, and
refactor the unused rule tracking to only track rule indexes.
This ends up being a net simplification, and reduction in code size.
The parser repeatedly invokes the `parse` function, constructing a
one-entry vector, and assuming that the return value will be a one-entry
vector. Add a helper for that case. This will simplify adding additional
callers, and put all the logic in one place to allow potential future
simplification of the one-TT case.
Stop using `Key` trait unnecessarily
Few places where the `Key` trait was being used but not really for a useful reason. This fixes those usages.
Namely, `<Ty as Key>::default_span()` is `DUMMY_SP` anyways.
Canonicalize input ty/ct infer/placeholder in the root universe
We shouldn't care what universe the inputs are, since we only ever do the leak check on the universes instantiated after entering the canonical binder.
