debuginfo: Remove some outdated stuff from LLVM DIBuilder binding.
These seem to be leftovers from various adaptations to changes in LLVM over time.
Perfect for a rollup.
r? @eddyb
Use a distinct error code for "if may be missing an else clause"
Introduce the possibility of assigning distinct error codes to the various origin types of E0308. Start by assigning E0317 for the "IfExpressionWithNoElse" case, and write a long diagnostic specific to this case.
Fixes#36596
This is overdue, even if range and RangeArgument is still unstable.
The stability attributes are the same ones as the other unstable item
(Bound) here, they don't seem to matter.
This addresses issue pointed out by niko that prior code would break
if the declaration order for generics does not match how they are fed
into the instantiation of the type itself. (Added some tests
exercising this scenario.)
We can't use more than usize's bits of a hash to select a bucket anyway,
so we only need to store that part in the table. This should be an
improvement for the size of the data structure on 32-bit platforms.
Smaller data means better cache utilization and hopefully better
performance.
Implement .zip() specialization for Map and Cloned.
The crucial thing for transparent specialization is that we want to
preserve the potential side effects.
The simplest example is that in this code snippet:
`(0..6).map(f).zip((0..4).map(g)).count()`
`f` will be called five times, and `g` four times. The last time for `f`
is when the other iterator is at its end, so this element is unused.
This side effect can be preserved without disturbing code generation for
simple uses of `.map()`.
The `Zip::next_back()` case is even more complicated, unfortunately.
debuginfo: Handle spread_arg case in MIR-trans in a more stable way.
Use `VariableAccess::DirectVariable` instead of `VariableAccess::IndirectVariable` in order not to make LLVM's SROA angry. This is a step towards fixing #36774 and #35547. At least, I can build Cargo with optimizations + debuginfo again.
r? @eddyb
The original sentence is:
> This example has two conversions: `Rc<String>` to `String` and then `String` to `&str`.
But it should be
> This example has two conversions: `Rc<String>` to `String` and then `String` to `str`.
or
> This example has two conversions: `&Rc<String>` to `&String` and then `&String` to `&str`.
I think the latter is more clearly.
It is good practice to implement Debug for public types, and
indicating what directory you're reading seems useful.
Signed-off-by: David Henningsson <diwic@ubuntu.com>
normalize types every time HR regions are erased
Associated type normalization is inhibited by higher-ranked regions.
Therefore, every time we erase them, we must re-normalize.
I was meaning to introduce this change some time ago, but we used
to erase regions in generic context, which broke this terribly (because
you can't always normalize in a generic context). That seems to be gone
now.
Ensure this by having a `erase_late_bound_regions_and_normalize`
function.
Fixes#37109 (the missing call was in mir::block).
r? @eddyb
rustdoc: Improve playground run buttons
The main change is to stop using javascript to generate the URLs and use
rustdoc instead.
This also adds run buttons to the error index examples.
You can test the changes at https://ollie27.github.io/rust_doc_test/.
Fixes#36621Fixes#36910
add a per-param-env cache to `impls_bound`
There used to be only a global cache, which led to uncached calls to
trait selection when there were type parameters.
This causes a 20% decrease in borrow-checking time and an overall 0.5% performance increase during bootstrapping (as borrow-checking tends to be a tiny part of compilation time).
Fixes#37106 (drop elaboration times are now ~half of borrow checking,
so might still be worthy of optimization, but not critical).
r? @pnkfelix
We introduce a new `one_time_diagnostics` field on
`rustc::session::Session` to hold a hashset of diagnostic messages we've
set once but don't want to see again (as uniquified by span and message
text), "lint level defined here" being the motivating example dealt with
here.
This is in the matter of #24690.
Change Substs to type alias for Slice<Kind> for interning
This changes the definition of `librustc::ty::subst::Substs` to be a type alias to `Slice<Kind>`. `Substs` was already interned, but can now make use of the efficient `PartialEq` and `Hash` impls on `librustc::ty::Slice`.
I'm working on collecting some timing data for this, will update when it's done.
I chose to leave the impls on `Substs<'tcx>` even though it's now just a type alias to `Slice<Kind<'tcx>>` because it has the smallest footprint on other portions of the compiler which depend on its API. It turns out to be a pretty huge diff if you change where Substs's methods live 😄. That said, I'm not necessarily sure it's the *best* implementation but it's probably the easiest/smallest to review.
Many thanks to @eddyb for both suggesting this as a project for learning more about the compiler, and the tireless ~~handholding~~ mentorship he provided.
Specialize Vec::extend to Vec::extend_from_slice
I tried using the existing `SpecExtend` as a helper trait for this, but the instances would always conflict with the instances higher up in the file, so I created a new helper trait.
Benchmarking `extend` vs `extend_from_slice` with an slice of 1000 `u64`s gives the following results:
```
before:
running 2 tests
test tests::bench_extend_from_slice ... bench: 166 ns/iter (+/- 78)
test tests::bench_extend_trait ... bench: 1,187 ns/iter (+/- 697)
after:
running 2 tests
test tests::bench_extend_from_slice ... bench: 149 ns/iter (+/- 87)
test tests::bench_extend_trait ... bench: 138 ns/iter (+/- 70)
```
