rustc_codegen_ssa: Better code generation for niche discriminants.
In some cases we can avoid arithmetic before checking whether a niche is a tag.
Also rename some identifiers around niches.
This is relevant to #101872
Retry failed macro matching for diagnostics
When a declarative macro fails to match, retry the matching to collect diagnostic info instead of collecting it on the fly in the hot path. Split out of #103439.
You made a bunch of changes to declarative macro matching, so
r? `@nnethercote`
This change should produce a few small perf wins: https://github.com/rust-lang/rust/pull/103439#issuecomment-1294249602
Recover wrong-cased keywords that start items
(_this pr was inspired by [this tweet](https://twitter.com/Azumanga/status/1552982326409367561)_)
r? `@estebank`
We've talked a bit about this recovery, but I just wanted to make sure that this is the right approach :)
For now I've only added the case insensitive recovery to `use`s, since most other items like `impl` blocks, modules, functions can start with multiple keywords which complicates the matter.
No longer lint against `#[must_use] async fn foo()`.
When encountering a statement that awaits on a `Future`, check if the
`Future`'s parent item is annotated with `#[must_use]` and emit a lint
if so. This effectively makes `must_use` an annotation on the
`Future::Output` instead of only the `Future` itself.
Fix#78149.
Usually, we do want to use the static C++ library when building rustc_llvm, but do not want to have that dependency at compiler runtime. Change the defaults to Make It So.
Use 64 bits for incremental cache in-file positions
We currently use a 32-bit integer to encode byte positions into the incremental cache.
This is not enough when the query chache file is >4GB.
As the overflow check was a `debug_assert`, it was removed in released compilers, making compilation succeed silently.
At the next compilation, cache decoding would try to read unrelated data because of garbled file position, triggering an ICE.
Fixes https://github.com/rust-lang/rust/issues/79786
(I'm closing that bug since it the original report and the subsequent questions are probably different instances. A new bug should be opened for new instances of that ICE.)
This commit is aimed at making compiler generated entry functions
(Basically just C `main` right now) more generic so other targets can do
similar things for custom entry. This was initially implemented as part
of https://github.com/rust-lang/rust/pull/100316.
Currently, this moves the entry function name and Call convention to the
target spec.
Signed-off-by: Ayush Singh <ayushsingh1325@gmail.com>
