NOTE: I was careful to make each change in a manner that preserves the
existing diagnostic output (usually by ensuring that no lines were
added or removed). This means that the resulting source files are not
as nice to read as they were at the start. But we will have to review
these cases by hand anyway as follow-up work, so cleanup could
reasonably happen then (or not at all).
Stabilize the copy_closures and clone_closures features
In addition to the `Fn*` family of traits, closures now implement `Copy` (and similarly `Clone`) if all of the captures do.
Tracking issue: https://github.com/rust-lang/rust/issues/44490
Add filtering options to `rustc_on_unimplemented`
- Add filtering options to `rustc_on_unimplemented` for local traits, filtering on `Self` and type arguments.
- Add a way to provide custom notes.
- Tweak binops text.
- Add filter to detect wether `Self` is local or belongs to another crate.
- Add filter to `Iterator` diagnostic for `&str`.
Partly addresses #44755 with a different syntax, as a first approach. Fixes#46216, fixes#37522, CC #34297, #46806.
Previously, when the type of a method receiver could not be determined,
the error message would, potentially confusingly, highlight the span of
the entire method call.
Resolves#36598, resolves#42234.
- filter error on the evaluated value of `Self`
- filter error on the evaluated value of the type arguments
- add argument to include custom note in diagnostic
- allow the parser to parse `Self` when processing attributes
- add custom message to binops
Sometimes the parser attempts to synthesize spans from within a macro
context with the span for the captured argument, leading to non-sensical
spans with very bad output. Given that an incorrect span is worse than
a partially incomplete span, when detecting this situation return only
one of the spans without mergin them.
Previously, unused variables would get a note that the warning could be
silenced by prefixing the variable with an underscore, but that doesn't
work for field shorthand patterns, which the liveness analysis didn't
know about.
The "to avoid this warning" verbiage seemed unnecessary.
Resolves#47390.
On E0283, point at method with the requirements
On required type annotation diagnostic error, point at method with the
requirements if the span is available.
CC #45453.
Properly parse impls for the never type `!`
Recover from missing `for` in `impl Trait for Type`
Prohibit inherent default impls and default impls of auto traits
Change wording in more diagnostics to use "auto traits"
Some minor code cleanups in the parser
Previously, on a type mismatch (and if this wasn't preëmpted by a
higher-priority suggestion), we would look for argumentless methods
returning the expected type, and list them in a `help` note.
This had two major shortcomings. Firstly, a lot of the suggestions didn't
really make sense (if you used a &str where a String was expected,
`.to_ascii_uppercase()` is probably not the solution you were hoping
for). Secondly, we weren't generating suggestions from the most useful
traits!
We address the first problem with an internal
`#[rustc_conversion_suggestion]` attribute meant to mark methods that keep
the "same value" in the relevant sense, just converting the type. We
address the second problem by making `FnCtxt.probe_for_return_type` pass
the `ProbeScope::AllTraits` to `probe_op`: this would seem to be safe
because grep reveals no other callers of `probe_for_return_type`.
Also, structured suggestions are preferred (because they're pretty, but
also for RLS and friends).
Also also, we make the E0055 autoderef recursion limit error use the
one-time-diagnostics set, because we can potentially hit the limit a lot
during probing. (Without this,
test/ui/did_you_mean/recursion_limit_deref.rs would report "aborting due to
51 errors").
Unfortunately, the trait probing is still not all one would hope for: at a
minimum, we don't know how to rule out `into()` in cases where it wouldn't
actually work, and we don't know how to rule in `.to_owned()` where it
would. Issues #46459 and #46460 have been filed and are ref'd in a FIXME.
This is hoped to resolve#42929, #44672, and #45777.
First cut at getting some part of the test suite working for CloudABI
I am currently working on creating a Docker container for automated CI for CloudABI. Here are some of the trivial changes that need to land to make tests pass.
It looks like many of these tests are already disabled on emscripten,
which also doesn't seem to support environment variables and subprocess
spawning. Just add a similar tag for CloudABI. While there, sort some of
the lists of operating systems alphabetically.
The previous message ("cannot assign/mutably borrow immutable field")
when trying to modify a field of an immutable binding gave the
(incorrect) impression that fields can be mutable independently of their
ADT's binding. Slightly reword the message to read "cannot
assign/mutably borrow field of immutable binding".
Point at whole method call instead of args
To avoid confusion in cases where the code is
```rust
fn foo() {}
/ foo(
| bar()
| ^^^ current diagnostics point here for arg count mismatch
| );
|_^ new diagnostic span points here
```
as this leads to confusion making people think that the diagnostic is
talking about `bar`'s arg count, not `foo`'s.
Point at `fn`s definition on arg mismatch, just like we do for closures.
Re #42855, Fix#45633.
To avoid confusion in cases where the code is
```rust
fn foo() {}
/ foo(
| bar()
| ^^^ current diagnostics point here for arg count mismatch
| );
|_^ new diagnostic span points here
```
as this leads to confusion making people think that the diagnostic is
talking about `bar`'s arg count, not `foo`'s.
Point at `fn`s definition on arg mismatch, just like we do for closures.
