* Changed btree_map's and hash_map's Entry (etc.) docs to be consistent
* Changed VecDeque's type and module summary sentences to be consistent
with each other as well as with other summary sentences in the module
* Changed HashMap's and HashSet's summary sentences to be less redundantly
phrased and also more consistant with the other summary sentences in the
module
* Also, added an example to Bound
* Added links where possible (limited because of facading)
* Changed references to methods from `foo()` to `foo` in module docs
* Changed references to methods from `HashMap::foo` to just `foo` in
top-level docs for `HashMap` and the `default` doc for `DefaultHasher`
* Various small other fixes
rustbuild: Fix recompilation of stage0 tools dir
This commit knocks out a longstanding FIXME in rustbuild which should correctly
recompile stage0 compiletest and such whenever libstd itself changes. The
solution implemented here was to implement a notion of "order only" dependencies
and then add a new dependency stage for clearing out the tools dir, using
order-only deps to ensure that it happens correctly.
The dependency drawing for tools is a bit wonky now but I think this'll get the
job done.
Closes#39396
Fix invalid 128-bit division on 32-bit target (#41228)
The bug of #41228 is a typo, this line: 1dca19ae3f/src/libcompiler_builtins/lib.rs (L183)
```rust
// 1 <= sr <= u64::bits() - 1
q = n.wrapping_shl(64u32.wrapping_sub(sr));
```
The **64** should be **128**.
(Compare with 280d19f112/src/int/udiv.rs (L213-L214):
```rust
// 1 <= sr <= <hty!($ty)>::bits() - 1
q = n << (<$ty>::bits() - sr);
```
Or compare with the C implementation https://github.com/llvm-mirror/compiler-rt/blob/master/lib/builtins/udivmodti4.c#L113-L116
```c
/* 1 <= sr <= n_udword_bits - 1 */
/* q.all = n.all << (n_utword_bits - sr); */
q.s.low = 0;
q.s.high = n.s.low << (n_udword_bits - sr);
```
)
Added a bunch of randomly generated division test cases to try to cover every described branch of `udivmodti4`.
This commit knocks out a longstanding FIXME in rustbuild which should correctly
recompile stage0 compiletest and such whenever libstd itself changes. The
solution implemented here was to implement a notion of "order only" dependencies
and then add a new dependency stage for clearing out the tools dir, using
order-only deps to ensure that it happens correctly.
The dependency drawing for tools is a bit wonky now but I think this'll get the
job done.
Closes#39396
This addresses concerns raised following the merge of #41092.
Specifically:
> The naming of these seems surprising: the multithreaded functions (and
> both the single and multithreaded intrinsics themselves) are fences,
> but this is a barrier. It's not incorrect, but the latter is both
> inconsistent with the existing functions and slightly confusing with
> another type in std (e.g., `Barrier`).
`compiler_fence` carries the same semantic implication that this is a
compiler-only operation, while being more in line with the fence/barrier
concepts already in use in `std`.
Improve the LLVM IR we generate for trivial functions, especially #[naked] ones.
These two small changes fixedef1c/libfringe#68:
* Don't emit ZST allocas, such as when returning `()`
* Don't emit a branch from LLVM's entry block to MIR's `START_BLOCK` unless needed
* That is, if a loop branches back to it, although I'm not sure that's even valid MIR
travis: Enable rust-analysis package for more targets
This commit enables the `rust-analysis` package to be produced for all targets
that are part of the `dist-*` suite of docker images on Travis. Currently
these packages are showing up with `available = false` in the
`channel-rust-nightly.toml` manifest where we'd prefer to have them show up for
all targets.
Unfortunately rustup isn't handling the `available = false` section well right
now, so this should also inadvertently fix the nightly regression.
Add a resource-reusing method to `ToOwned`
`ToOwned::to_owned` generalizes `Clone::clone`, but `ToOwned` doesn't have an equivalent to `Clone::clone_from`. This PR adds such a method as `clone_into` under a new unstable feature `toowned_clone_into`.
Analogous to `clone_from`, this has the obvious default implementation in terms of `to_owned`. I've updated the `libcollections` impls: for `T:Clone` it uses `clone_from`, for `[T]` I moved the code from `Vec::clone_from` and implemented that in terms of this, and for `str` it's a predictable implementation in terms of `[u8]`.
Used it in `Cow::clone_from` to reuse resources when both are `Cow::Owned`, and added a test that `Cow<str>` thus keeps capacity in `clone_from` in that situation.
The obvious question: is this the right place for the method?
- It's here so it lives next to `to_owned`, making the default implementation reasonable, and avoiding another trait. But allowing method syntax forces a name like `clone_into`, rather than something more consistent like `owned_from`.
- Another trait would allow `owned_from` and could support multiple owning types per borrow type. But it'd be another single-method trait that generalizes `Clone`, and I don't know how to give it a default impl in terms of `ToOwned::to_owned`, since a blanket would mean overlapping impls problems.
I did it this way as it's simpler and many of the `Borrow`s/`AsRef`s don't make sense with `owned_from` anyway (`[T;1]:Borrow<[T]>`, `Arc<T>:Borrow<T>`, `String:AsRef<OsStr>`...). I'd be happy to re-do it the other way, though, if someone has a good solution for the default handling.
(I can also update with `CStr`, `OsStr`, and `Path` once a direction is decided.)
Windows builder croaked. This change tries to fix that by actually
calling the global_asm-defined function so the symbol doesn't get
optimized away, if that is in fact what was happening.
Additionally, we provide an empty main() for non-x86 arches.
This commit enables the `rust-analysis` package to be produced for all targets
that are part of the `dist-*` suite of docker images on Travis. Currently
these packages are showing up with `available = false` in the
`channel-rust-nightly.toml` manifest where we'd prefer to have them show up for
all targets.
Unfortunately rustup isn't handling the `available = false` section well right
now, so this should also inadvertently fix the nightly regression.
Handle subtyping in inference through obligations
We currently store subtyping relations in the `TypeVariables` structure as a kind of special case. This branch uses normal obligations to propagate subtyping, thus converting our inference variables into normal fallback. It also does a few other things:
- Removes the (unstable, outdated) support for custom type inference fallback.
- It's not clear how we want this to work, but we know that we don't want it to work the way it currently does.
- The existing support was also just getting in my way.
- Fixes#30225, which was caused by the trait caching code pretending type variables were normal unification variables, when indeed they were not (but now are).
There is one fishy part of these changes: when computing the LUB/GLB of a "bivariant" type parameter, I currently return the `a` value. Bivariant type parameters are only allowed in a very particular situation, where the type parameter is only used as an associated type output, like this:
```rust
pub struct Foo<A, B>
where A: Fn() -> B
{
data: A
}
```
In principle, if one had `T=Foo<A, &'a u32>` and `U=Foo<A, &'b u32>` and (e.g.) `A: for<'a> Fn() -> &'a u32`, then I think that computing the LUB of `T` and `U` might do the wrong thing. Probably the right behavior is just to create a fresh type variable. However, that particular example would not compile (because the where-clause is illegal; `'a` does not appear in any input type). I was not able to make an example that *would* compile and demonstrate this shortcoming, and handling the LUB/GLB was mildly inconvenient, so I left it as is. I am considering whether to revisit this or what.
I have started a crater run to test the impact of these changes.
to_owned generalizes clone; this generalizes clone_from. Use to_owned to
give it a default impl. Customize the impl for [T], str, and T:Clone.
Use it in Cow::clone_from to reuse resources when cloning Owned into Owned.
Travis failures indicated the OuterVisitor#visit_item method caused a
panic. The Visitor's inner visitor actually relies on the visitor
visiting every item's NodeId. I forgot to perform that call in the
ItemGlobalAsm match arm, leading to build breakage. The fix is
simple: call visit_id(...) for ItemGlobalAsm
Derive Hash for ThreadId + better example
Derive `Hash` for `ThreadId` (see comments in #21507). Useful for making maps based on thread, e.g. `HashMap<ThreadId, ?>`. Also update example code for thread IDs to be more useful.
Fix pairs of doubles using an illegal <8 x i8> vector.
Accidentally introduced in #40658 and discovered in some Objective-C bindings (returning `NSPoint`).
Turns out LLVM will widen element types of illegal vectors instead of increasing element count, i.e. it will zero-extend `<8 x i8>` to `<8 x i16>`, interleaving the bytes, instead of using the first 8 of `<16 x i8>`.
Highlight and simplify mismatched types
Shorten mismatched types errors by replacing subtypes that are not
different with `_`, and highlighting only the subtypes that are
different.
Given a file
```rust
struct X<T1, T2> {
x: T1,
y: T2,
}
fn foo() -> X<X<String, String>, String> {
X { x: X {x: "".to_string(), y: 2}, y: "".to_string()}
}
fn bar() -> Option<String> {
"".to_string()
}
```
provide the following output
```rust
error[E0308]: mismatched types
--> file.rs:6:5
|
6 | X { x: X {x: "".to_string(), y: 2}, y: "".to_string()}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected struct `std::string::String`, found {integer}
|
= note: expected type `X<X<_, std::string::String>, _>`
^^^^^^^^^^^^^^^^^^^ // < highlighted
found type `X<X<_, {integer}>, _>`
^^^^^^^^^ // < highlighted
error[E0308]: mismatched types
--> file.rs:6:5
|
10 | "".to_string()
| ^^^^^^^^^^^^^^ expected struct `std::option::Option`, found `std::string::String`
|
= note: expected type `Option<std::string::String>`
^^^^^^^ ^ // < highlighted
found type `std::string::String`
```
Fix#21025. Re: #40186. Follow up to #39906.
I'm looking to change how this output is accomplished so that it doesn't create list of strings to pass around, but rather add an elided `Ty` placeholder, and use the same string formatting for normal types. I'll be doing that soonish.
r? @nikomatsakis
ICH: Replace old, transitive metadata hashing with direct hashing approach.
This PR replaces the old crate metadata hashing strategy with a new one that directly (but stably) hashes all values we encode into the metadata. Previously we would track what data got accessed during metadata encoding and then hash the input nodes (HIR and upstream metadata) that were transitively reachable from the accessed data. While this strategy was sound, it had two major downsides:
1. It was susceptible to generating false positives, i.e. some input node might have changed without actually affecting the content of the metadata. That metadata entry would still show up as changed.
2. It was susceptible to quadratic blow-up when many metadata nodes shared the same input nodes, which would then get hashed over and over again.
The new method does not have these disadvantages and it's also a first step towards caching more intermediate results in the compiler.
Metadata hashing/cross-crate incremental compilation is still kept behind the `-Zincremental-cc` flag even after this PR. Once the new method has proven itself with more tests, we can remove the flag and enable cross-crate support by default again.
r? @nikomatsakis
cc @rust-lang/compiler
