Individualize feature gates for const fn invocation
This PR changes the meaning of `#![feature(const_fn)]` so it is only required to declare a const fn but not to call one. Based on discussion at #24111. I was hoping we could have an FCP here in order to move that conversation forward.
This sets the stage for future stabilization of the constness of several functions in the standard library (listed below), so could someone please tag the lang team for review.
- `std::cell`
- `Cell::new`
- `RefCell::new`
- `UnsafeCell::new`
- `std::mem`
- `size_of`
- `align_of`
- `std::ptr`
- `null`
- `null_mut`
- `std::sync`
- `atomic`
- `Atomic{Bool,Ptr,Isize,Usize}::new`
- `once`
- `Once::new`
- primitives
- `{integer}::min_value`
- `{integer}::max_value`
Some other functions are const but they are also unstable or hidden, e.g. `Unique::new` so they don't have to be considered at this time.
After this stabilization, the following `*_INIT` constants in the standard library can be deprecated. I wasn't sure whether to include those deprecations in the current PR.
- `std::sync`
- `atomic`
- `ATOMIC_{BOOL,ISIZE,USIZE}_INIT`
- `once`
- `ONCE_INIT`
Moving buckets from us-east-1 to us-west-1 because us-west-1 is where
rust-central-station itself runs and in general is where we have all our other
buckets.
rustbuild: Compile the error-index in stage 2
Right now we comiple rustdoc in stage 2 and the error index in stage 0, which
ends up compiling rustdoc twice! To avoid compiling rustdoc twice (which takes
awhile) let's just compile it once in stage 2.
travis: Disable LLVM assertions on OSX
Our OSX builders are routinely and significantly over hour 2 hour "soft limit"
for testing PRs. I *think* that a big portion of this time comes from the fact
that LLVM and debug assertions are enabled. In an effort to speed up these
builders and reduce cycle time this commit disables LLVM assertions on OSX for
all builders.
My thinking is that we'll let this bake for a bit after merged to see what the
effect is on timing on Travis. If it doesn't actually help much we can turn them
back on, and if it doesn't help enough we can disable Rust debug assertions as
well.
Previously it would use the librustc output directory which would cause rustdoc
to get entirely recompiled, whereas the intention is that it uses the
already-compiled artifacts from building rustdoc itself, using the tool output
directory
Our OSX builders are routinely and significantly over hour 2 hour "soft limit"
for testing PRs. I *think* that a big portion of this time comes from the fact
that LLVM and debug assertions are enabled. In an effort to speed up these
builders and reduce cycle time this commit disables LLVM assertions on OSX for
all builders.
My thinking is that we'll let this bake for a bit after merged to see what the
effect is on timing on Travis. If it doesn't actually help much we can turn them
back on, and if it doesn't help enough we can disable Rust debug assertions as
well.
Right now we comiple rustdoc in stage 2 and the error index in stage 0, which
ends up compiling rustdoc twice! To avoid compiling rustdoc twice (which takes
awhile) let's just compile it once in stage 2.
Compile fail stable
Since #30726, we never made the `compile_fail` flag nor the error code check stable. I think it's time to change this fact.
r? @alexcrichton
This commit alters the `query` function in the dep graph module to preallocate
memory using `with_capacity` instead of relying on automatic growth. Discovered
in #44576 it was found that for the syntex_syntax clean incremental benchmark
the peak memory usage was found when the dep graph was being saved, particularly
the `DepGraphQuery` data structure itself. PRs like #44142 which add more
queries end up just making this much larger!
I didn't see an immediately obvious way to reduce the size of the
`DepGraphQuery` object, but it turns out that `with_capacity` helps quite a bit!
Locally 831 MB was used [before] this commit, and 770 MB is in use at the peak
of the compiler [after] this commit. That's a nice 7.5% improvement! This won't
quite make up for the losses in #44142 but I figured it's a good start.
[before]: https://gist.github.com/alexcrichton/2d2b9c7a65503761925c5a0bcfeb0d1e
[before]: https://gist.github.com/alexcrichton/6da51f2a6184bfb81694cc44f06deb5b
Fix example in transmute; add safety requirement to Vec::from_raw_parts
This fixes the second bullet point on #44281 and also removes some incorrect information.
Fix drain_filter doctest.
Fixes#44499.
Also change some of the hidden logic in the doctest as a regression test; two bugs in the original would now cause test failure.
