This commit attaches a channel to the LLVM workers to the `TyCtxt` which will
later be used during the codegen query to actually send work to LLVM workers.
Otherwise this commit is just plumbing this channel throughout the compiler to
ensure it reaches the right consumers.
This commit removes the `crate_trans_items` field from the `CrateContext` of
trans. This field, a big map, was calculated during partioning and was a set of
all translation items. This isn't quite incremental-friendly because the map may
change a lot but not have much effect on downstream consumers.
Instead a new query was added for the one location this map was needed, along
with a new comment explaining what the location is doing!
This is a big map that ends up inside of a `CrateContext` during translation for
all codegen units. This means that any change to the map may end up causing an
incremental recompilation of a codegen unit! In order to reduce the amount of
dependencies here between codegen units and the actual input crate this commit
refactors dealing with exported symbols and such into various queries.
The new queries are largely based on existing queries with filled out
implementations for the local crate in addition to external crates, but the main
idea is that while translating codegen untis no unit needs the entire set of
exported symbols, instead they only need queries about particulare `DefId`
instances every now and then.
The linking stage, however, still generates a full list of all exported symbols
from all crates, but that's going to always happen unconditionally anyway, so no
news there!
Otherwise we may emit double errors related to the `#[export_name]` attribute,
for example, and using a query should ensure that it's only emitted at most
once.
This commit moves the `collect_and_partition_translation_items` function into a
query on `TyCtxt` instead of a free function in trans, allowing us to track
dependencies and such of the function.
This commit moves the definition of the `ExportedSymbols` structure to the
`rustc` crate and then creates a query that'll be used to construct the
`ExportedSymbols` set. This in turn uses the reachablity query exposed in the
previous commit.
rustc: Preallocate when building the dep graph
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
bring TyCtxt into scope
got comments both from @eddyb and @nikomatsakis (via https://github.com/rust-lang/rust/pull/44505) that we should always put `TyCtxt` in scope
should I just go and import it at other places in the codebase or we just keep doing small improvements?
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`
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
This commit removes the `dep_graph` field from the `Session` type according to
issue #44390. Most of the fallout here was relatively straightforward and the
`prepare_session_directory` function was rejiggered a bit to reuse the results
in the later-called `load_dep_graph` function.
Closes#44390
Remove deprecated lang items
They have been deprecated for years and there is no trace left of them in the compiler. Also removed `require_owned_box` which is dead code and other small refactorings.
Extend E0623 for fn items
This fixes#44516
The below example now gives
```
error[E0623]: lifetime mismatch
--> gg.rs:3:10
|
2 | fn foo(x:fn(&u8, &u8), y: Vec<&u8>, z: &u8) {
| --- --- these two types are declared with different lifetimes...
3 | y.push(z);
| ^ ...but data from `z` flows into `y` here
error: aborting due to previous error
```
r? @nikomatsakis
cc @arielb1
Evaluate fixed-length array length expressions lazily.
This is in preparation for polymorphic array lengths (aka `[T; T::A]`) and const generics.
We need deferred const-evaluation to break cycles when array types show up in positions which require knowing the array type to typeck the array length, e.g. the array type is in a `where` clause.
The final step - actually passing bounds in scope to array length expressions from the parent - is not done because it still produces cycles when *normalizing* `ParamEnv`s, and @nikomatsakis' in-progress lazy normalization work is needed to deal with that uniformly.
However, the changes here are still useful to unlock work on const generics, which @EpicatSupercell manifested interest in, and I might be mentoring them for that, but we need this baseline first.
r? @nikomatsakis cc @oli-obk
This'll allow us to reconstruct query parameters purely from the `DepNode`
they're associated with. Some queries could move straight to `HirId` but others
that don't always have a correspondance between `HirId` and `DefId` moved to
two-level maps where the query operates over a `DefIndex`, returning a map,
which is then keyed off `ItemLocalId`.
Closes#44414
Extend E0623 for LateBound and EarlyBound Regions
This is a fix for #43882
```
fn foo<'a,'b>(x: &mut Vec<&'a u8>, y: &'b u8) {
x.push(y);
}
```
now gives
```
error[E0623]: lifetime mismatch
--> $DIR/ex3-both-anon-regions-latebound-regions.rs:12:12
|
11 | fn foo<'a,'b>(x: &mut Vec<&'a u8>, y: &'b u8) {
| ------ ------ these two types are declared with different lifetimes...
12 | x.push(y);
| ^ ...but data from `y` flows into `x` here
```
cc @nikomatsakis @arielb1
Please ignore the second commit. It will be merged in a separate PR.
