Auto merge of #43426 - qnighy:intercrate-ambiguity-hints, r=nikomatsakis
Add hints when intercrate ambiguity causes overlap.
I'm going to tackle #23980.
# Examples
## Trait impl overlap caused by possible downstream impl
```rust
trait Foo<X> {}
trait Bar<X> {}
impl<X, T> Foo<X> for T where T: Bar<X> {}
impl<X> Foo<X> for i32 {}
fn main() {}
```
```
error[E0119]: conflicting implementations of trait `Foo<_>` for type `i32`:
--> test1.rs:4:1
|
3 | impl<X, T> Foo<X> for T where T: Bar<X> {}
| ------------------------------------------ first implementation here
4 | impl<X> Foo<X> for i32 {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `i32`
|
= note: downstream crates may implement Bar
error: aborting due to previous error
```
## Trait impl overlap caused by possible upstream update
```rust
trait Foo {}
impl<T> Foo for T where T: ::std::fmt::Octal {}
impl Foo for () {}
fn main() {}
```
```
error[E0119]: conflicting implementations of trait `Foo` for type `()`:
--> test2.rs:3:1
|
2 | impl<T> Foo for T where T: ::std::fmt::Octal {}
| ----------------------------------------------- first implementation here
3 | impl Foo for () {}
| ^^^^^^^^^^^^^^^^^^ conflicting implementation for `()`
|
= note: upstream crates may add new impl for std::fmt::Octal in future versions
error: aborting due to previous error
```
## Inherent impl overlap caused by possible downstream impl
Auto merge of #44194 - QuietMisdreavus:hey-how-do-i-use-this-new-fangled-thing, r=aturon
expand on using rustup custom toolchains in CONTRIBUTING.md
fixes #42484
Should i include more notes about how to use a local build *without* rustup? It can kinda feel like a cop-out otherwise. Other means that come to mind are setting `$RUSTC` directly and fully installing it.
Auto merge of #44191 - arielb1:on-unimplemented-label, r=nikomatsakis
More general `on_unimplemented`, with uses in `Try`
Allow `on_unimplemented` directives to specify both the label and the primary message of the trait error, and allow them to be controlled by flags - currently only to be desugaring-sensitive.
e.g.
```Rust
#[rustc_on_unimplemented(
on(all(direct, from_desugaring="?"),
message="the `?` operator can only be used in a \
function that returns `Result` \
(or another type that implements `{Try}`)",
label="cannot use the `?` operator in a function that returns `{Self}`"),
)]
```
Auto merge of #44252 - eddyb:what-is-dead-may-never-die, r=nikomatsakis
Better StorageLive / StorageDead placement for constants.
Fixes problems in miri (see https://github.com/solson/miri/pull/324#issuecomment-326555552) caused by the new scope rules in #43932.
What I've tried to do here is always have a `StorageLive` but no `StorageDead` for `'static` slots.
It might not work perfectly in all cases, but it should unblock miri.
Auto merge of #44066 - cuviper:powerpc64-extern-abi, r=alexcrichton
powerpc64: improve extern struct ABI
These fixes all have to do with the 64-bit PowerPC ELF ABI for big-endian
targets. The ELF v2 ABI for powerpc64le already worked well.
- Return after marking return aggregates indirect. Fixes #42757.
- Pass one-member float aggregates as direct argument values.
- Aggregate arguments less than 64-bit must be written in the least-
significant bits of the parameter space.
- Larger aggregates are instead padded at the tail.
(i.e. filling MSBs, padding the remaining LSBs.)
New tests were also added for the single-float aggregate, and a 3-byte
aggregate to check that it's filled into LSBs. Overall, at least these
formerly-failing tests now pass on powerpc64:
~~This builds clippy as part of `./x.py build` (locally and in CI).~~
This allows building clippy with `./x.py build src/tools/clippy`
~~Needs https://github.com/nrc/dev-tools-team/issues/18#issuecomment-322456461 to be resolved before it can be merged.~~ Contributers can simply open a PR to clippy and point the submodule at the `pull/$pr_number/head` branch.
This does **not** build clippy or test the clippy test suite at all as per https://github.com/nrc/dev-tools-team/issues/18#issuecomment-321411418
Auto merge of #44259 - Mark-Simulacrum:update-cargo, r=alexcrichton
Update cargo
This includes https://github.com/rust-lang/cargo/pull/4447 which fixes a bug in Cargo that is needed to fix https://github.com/rust-lang/rust/issues/44237.
Auto merge of #44104 - llogiq:lowercase-lints, r=nikomatsakis
add a lowercase suggestion to unknown_lints
I recently wrote some tests for a clippy lint, copied the (uppercase) lint name into my test file and forgot to toggle the case. This PR adds a suggestion that would have saved me 10 minutes of debugging, so it's likely a net win 🙂 . Also it adds a UI test for the `unknown_lints` lint.
Mark Simulacrum [Sat, 2 Sep 2017 03:15:47 +0000 (21:15 -0600)]
Update cargo.
This includes https://github.com/rust-lang/cargo/pull/4447 which fixes
a bug in Cargo that is needed to fix
https://github.com/rust-lang/rust/issues/44237.
Josh Stone [Fri, 1 Sep 2017 23:05:19 +0000 (16:05 -0700)]
x86: return single-float aggregates in a float register
Following Clang's lead, and anecdotal evidence from the `float_one` part
of `run-make/extern-fn-struct-passing-abi`, use a floating point
register to return single-float aggregates, except on MSVC targets.
Josh Stone [Wed, 23 Aug 2017 21:38:45 +0000 (17:38 -0400)]
powerpc64: improve extern struct ABI
These fixes all have to do with the 64-bit PowerPC ELF ABI for big-endian
targets. The ELF v2 ABI for powerpc64le already worked well.
- Return after marking return aggregates indirect. Fixes #42757.
- Pass one-member float aggregates as direct argument values.
- Aggregate arguments less than 64-bit must be written in the least-
significant bits of the parameter space.
- Larger aggregates are instead padded at the tail.
(i.e. filling MSBs, padding the remaining LSBs.)
New tests were also added for the single-float aggregate, and a 3-byte
aggregate to check that it's filled into LSBs. Overall, at least these
formerly-failing tests now pass on powerpc64:
Auto merge of #44171 - eddyb:scope, r=nikomatsakis
Use hir::ItemLocalId instead of ast::NodeId in rustc::middle::region::CodeExtent.
This is an alternative to @michaelwoerister's #43887, changing `CodeExtent` instead of `ReScope`.
The benefit here is that the same `Region`s are used same-crate and cross-crate, while preserving the incremental recompilation properties of the stable `hir::ItemLocalId`.
Only places which needed to get back to the `ast::NodeId` from `CodeExtent` was its `span` method, used in error reporting - passing the `&RegionMaps` down allowed using `hir_to_node_id`.
`rustc::cfg` and `dataflow` also had to be converted to `hir::ItemLocalId` because of their interactions with `CodeExtent`, especially in `borrowck`, and from that we have 3 more `hir_to_node_id` calls: `cfg::graphviz` node labels, `borrowck` move reporting, and the `unconditional_recursion` lint.
Out of all of those, *only* the lint actually makes a decision (on whether code will compile) based on the result of the conversion, the others only use it to know how to print information to the user.
So I think we're safe to say that the bulk of the code working with a `CodeExtent` is fine with local IDs.
Mark Simulacrum [Fri, 1 Sep 2017 00:07:45 +0000 (18:07 -0600)]
Rollup merge of #44207 - durka:define-maps-fn, r=eddyb
add `fn` to syntax of rustc::ty::maps::define_maps
This is not a functional change, it just makes it possible to find a query by grepping without knowing that it's a query rather than a function.
I didn't pursue renaming everything from "map" to "query" because it seems to be a very invasive change. It would be a good test to exercise an IDE's renaming features.
Mark Simulacrum [Fri, 1 Sep 2017 00:07:43 +0000 (18:07 -0600)]
Rollup merge of #44203 - cuviper:compiler-rt-test, r=Mark-Simulacrum
rustbuild: update the rust-src filter for compiler-rt
We wanted `src/compiler-rt/test` filtered from the `rust-src` package,
but that path is now `src/libcompiler_builtins/compiler-rt/test`. This
saves over half of the installed rust-src size. (50MB -> 22MB)