Rollup of 8 pull requests
Successful merges:
- #67585 (Improve `char::is_ascii_*` codegen)
- #68914 (Speed up `SipHasher128`.)
- #68994 (rustbuild: include channel in sanitizers installed name)
- #69032 (ICE in nightly-2020-02-08: handle TerminatorKind::Yield in librustc_mir::transform::promote_consts::Validator method)
- #69034 (parser: Remove `Parser::prev_token_kind`)
- #69042 (Remove backtrace header text)
- #69059 (Remove a few unused objects)
- #69089 (Properly use the darwin archive format on Apple targets)
Failed merges:
r? @ghost
ICE in nightly-2020-02-08: handle TerminatorKind::Yield in librustc_mir::transform::promote_consts::Validator method
IR: https://github.com/rust-lang/rust/issues/69017
regressed commit: f8fd462447
Source: https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=55e65a869e1f5fef64cc4462b1a5a087
Addresses ICE reported in #69017 by handling `TerminatorKind::Yield` in 4d1241f515/src/librustc_mir/transform/promote_consts.rs (L465-L468).
<details><summary>Nightly build</summary>
<p>
```
$ cargo +nightly build
Compiling yielder v0.1.0 (/Users/chris/Desktop/tests/rustlang-tests/yielder)
error: internal compiler error: src/librustc_mir/transform/promote_consts.rs:467: _1 = suspend(move _21) -> [resume: bb2, drop: bb3] not promotable
--> src/main.rs:8:27
|
8 | println!("-> {}", yield);
| ^^^^^
thread 'rustc' panicked at 'Box<Any>', <::std::macros::panic macros>:2:4
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: rustc 1.43.0-nightly (71c7e149e 2020-02-09) running on x86_64-apple-darwin
note: compiler flags: -C debuginfo=2 -C incremental --crate-type bin
note: some of the compiler flags provided by cargo are hidden
error: aborting due to previous error
error: could not compile `yielder`.
To learn more, run the command again with --verbose.
```
</p>
</details>
<details><summary>Stage 1 dev build</summary>
<p>
```
$ cargo +stage1 build
Compiling yielder v0.1.0 (/Users/chris/Desktop/tests/rustlang-tests/yielder)
warning: function is never used: `gen`
--> src/main.rs:6:4
|
6 | fn gen() -> impl Generator<usize> {
| ^^^
|
= note: `#[warn(dead_code)]` on by default
Finished dev [unoptimized + debuginfo] target(s) in 0.53s
```
</p>
</details>
@jonas-schievink @oli-obk
Migrate borrowck dataflow impls to new framework
This uses #65672 to implement the dataflow analyses needed by borrowck. These include all the `InitializedPlaces` analyses as well as `Borrows`. Additionally, this PR contains several independent changes around the dataflow API which improve performance and make it more ergonomic.
* An optimization that inhibits the caching of block transfer functions for acyclic MIR (~0.3% I-CNT savings).
* A `ResultsVisitor` for dataflow results that is more efficient than `ResultsCursor` when we have to visit every statement unconditionally (~0.3% I-CNT savings).
* An `into_engine` method on `Analysis` that selects the appropriate `Engine` constructor.
* A `contains` method for `ResultsCursor` as a shorthand for `.get().contains()`.
* A `find_descendants` helper on `MovePath` that replaces `has_any_child_of` on the old `FlowsAtLocation`
These changes made porting the dataflow analyses much easier. Finally, this PR removes some now-unused code in `dataflow/at_location.rs` and elsewhere.
You can view the perf results for the final version of this PR [here](https://perf.rust-lang.org/compare.html?start=29b854fb741809c29764e33fc17c32ba9c6523ba&end=6e516c1410c18cfe4eb6d030a39fdb73c8d8a4fe). Here's an example of the graphviz diagrams that are generated for the `MaybeInitializedPlaces` analysis.
Remove common usage pattern from `AllocRef`
This removes the common usage patterns from `AllocRef`:
- `alloc_one`
- `dealloc_one`
- `alloc_array`
- `realloc_array`
- `dealloc_array`
Actually, they add nothing to `AllocRef` except a [convenience wrapper around `Layout` and other methods in this trait](https://doc.rust-lang.org/1.41.0/src/core/alloc.rs.html#1076-1240) but have a major flaw: The documentation of `AllocRefs` notes, that
> some higher-level allocation methods (`alloc_one`, `alloc_array`) are well-defined on zero-sized types and can optionally support them: it is left up to the implementor whether to return `Err`, or to return `Ok` with some pointer.
With the current API, `GlobalAlloc` does not have those methods, so they cannot be overridden for `liballoc::Global`, which means that even if the global allocator would support zero-sized allocations, `alloc_one`, `alloc_array`, and `realloc_array` for `liballoc::Global` will error, while calling `alloc` with a zeroed-size `Layout` could succeed. Even worse: allocating with `alloc` and deallocating with `dealloc_{one,array}` could end up with not calling `dealloc` at all!
For the full discussion please see https://github.com/rust-lang/wg-allocators/issues/18
r? @Amanieu
Test failure of unchecked arithmetic intrinsics in const eval
Test that the unchecked arithmetic intrinsics that were made unstably const in #68809 emit an error during const-eval if given invalid input.
Addresses [this comment](https://github.com/rust-lang/rust/pull/68809#discussion_r375753066).
r? @RalfJung
Use `dyn Trait` more in tests
Here are some tests using the old trait object type syntax which are not testing the syntax itself.
This has been extracted from https://github.com/rust-lang/rust/pull/66364.
Remove unused feature gates
I think many of the remaining unstable things can be easily be replaced with stable things. I have kept the `#![feature(nll)]` even though it is only necessary in `libstd`, to make regressions of it harder.
change an instance of span_bug() to struct_span_err() to avoid ICE
After #67148, the `span_bug()` in `parse_ty_tuple_or_parens()` is reachable because `parse_paren_comma_seq()` can return an `Ok()` even in cases where it encounters an error.
This pull request prevents an ICE in such cases by replacing the `span_bug()` with `struct_span_error()`.
Fixes#68890.
Add long error code explanation message for E0637
Reference issue [#61137](https://github.com/rust-lang/rust/issues/61137)
To incorporate a long error description for E0637, I have made the necessary modification to error_codes.rs and added error_codes/E0637.md, and blessed the relevant .stderror files. ~~, however when I build rustc stage 1, I am unable to make `$ rustc --explain E0637` work even though rustc appears to be able to call up the long error explanations for other errors. I wanted to guarantee this would work before moving on the blessing the various ui tests that have been affected. @GuillaumeGomez Do you know the most likely reason(s) why this would be the case?~~
Update: `$ rustc --explain E0637` works now.
Rollup of 6 pull requests
Successful merges:
- #68694 (Reduce the number of `RefCell`s in `InferCtxt`.)
- #68966 (Improve performance of coherence checks)
- #68976 (Make `num::NonZeroX::new` an unstable `const fn`)
- #68992 (Correctly parse `mut a @ b`)
- #69005 (Small graphviz improvements for the new dataflow framework)
- #69006 (parser: Keep current and previous tokens precisely)
Failed merges:
r? @ghost
parser: Keep current and previous tokens precisely
...including their unnormalized forms.
Add more documentation for them.
Hopefully, this will help to eliminate footguns like https://github.com/rust-lang/rust/pull/68728#discussion_r373787486.
I'll try to address the FIXMEs in separate PRs during the next week.
r? @Centril
Make `num::NonZeroX::new` an unstable `const fn`
cc #53718
These require `#[feature(const_if_match)]`, meaning they must remain unstable for the time being.
This has negligible perf impact, but it does improve the code a bit.
* Only query the specialization graph of any trait once instead of once per
impl
* Loop over impls only once, precomputing impl DefId and TraitRef
Improve reporting errors and suggestions for trait bounds
Fix#66802
- When printing errors for unsized function parameter, properly point at the parameter instead of function's body.
- Improve `consider further restricting this bound` (and related) messages by separating human-oriented hints from the machine-oriented ones.
When suggesting associated fn with type parameters, include in the structured suggestion
Address #50734.
```
error[E0046]: not all trait items implemented, missing: `foo`, `bar`, `baz`
--> file.rs:14:1
|
14 | impl TraitA<()> for S {
| ^^^^^^^^^^^^^^^^^^^^^ missing `foo`, `bar`, `baz` in implementation
|
= help: implement the missing item: `fn foo<T>(_: T) -> Self where T: TraitB, TraitB::Item = A { unimplemented!() }`
= help: implement the missing item: `fn bar<T>(_: T) -> Self { unimplemented!() }`
= help: implement the missing item: `fn baz<T>(_: T) -> Self where T: TraitB, <T as TraitB>::Item: std::marker::Copy { unimplemented!() }`
```
It doesn't work well for associated types with `ty::Predicate::Projection`s as we need to resugar `T: Trait, Trait::Assoc = K` → `T: Trait<Assoc = K>`.
Initial implementation of `#![feature(move_ref_pattern)]`
Following up on #45600, under the gate `#![feature(move_ref_pattern)]`, `(ref x, mut y)` is allowed subject to restrictions necessary for soundness. The match checking implementation and tests for `#![feature(bindings_after_at)]` is also adjusted as necessary.
Closes#45600.
Tracking issue: #68354.
r? @matthewjasper
rustc_codegen_ssa: don't treat inlined variables as debuginfo arguments.
Fixes#67586 by limiting `ArgumentVariable` special-casing to `VarDebugInfo` entries that are in `OUTERMOST_SOURCE_SCOPE`, i.e. the function's own argument scope.
That excludes `VarDebugInfo` from inlined callees, which can also point to the caller's argument locals.
This is a snippet from the optimized MIR (including inlining) of the testcase:
```rust
fn foo(_1: usize) -> usize {
debug bar => _1; // in scope 0 at ./example.rs:2:12: 2:15
let mut _0: usize; // return place in scope 0 at ./example.rs:2:27: 2:32
scope 1 {
debug x => _1; // in scope 1 at /rustc/9ed29b6ff6aa2e048b09c27af8f62ee3040bdb37/src/libcore/convert/mod.rs:106:26: 106:27
}
```
`scope 1` is from inlining the `identity` call, and `debug x => _1;` comes from the body of `core::convert::identity`, so they are now ignored for the purposes of determining the `ArgumentVariable` debuginfo associated to `_1`.
rustc_target: treat enum variants like union members, in call ABIs.
Fixes#68190, by handling non-C-like `enum`s as-if they were an `union` of `struct`s, in call ABIs.
Tests were provided by @sw17ch, from theirs and @bitwalker's original examples.
cc @nagisa @rkruppe
