Miscellneous refactorings of trans
This doesn't achieve any particular goal yet, but it's a collection of refactorings with the common goal of turning `SharedCrateContext` etc into stuff that we can use with on-demand and actually expect to hash in a stable fashion for incremental. Not there yet, clearly.
r? @eddyb
cc @michaelwoerister
rustc_typeck: consolidate adjustment composition
Instead of having `write_adjustment` overwrite the previous adjustment, have `apply_adjustment` compose a new adjustment on top of the previous one. This is important because `NeverToAny` adjustments can be present on expressions during coercion.
Fixes#41213.
r? @nikomatsakis
A number of things were using `crate_hash` that really ought to be using
`crate_disambiguator` (e.g., to create the plugin symbol names). They
have been updated.
It is important to remove `LinkMeta` from `SharedCrateContext` since it
contains a hash of the entire crate, and hence it will change
whenever **anything** changes (which would then require
rebuilding **everything**).
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
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.)
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.
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
