Add help message for incorrect pattern syntax
When I was getting started with rust I often made the mistake of using `||` instead of `|` to match multiple patterns and spent a long time staring at my code wondering what was wrong.
for example:
```
fn main() {
let x = 1;
match x {
1 || 2 => println!("1 or 2"),
_ => println!("Something else"),
}
}
```
If you compile this with current rustc you will see
```
error: expected one of `...`, `..=`, `..`, `=>`, `if`, or `|`, found `||`
--> test.rs:5:11
|
5 | 1 || 2 => println!("1 or 2"),
| -^^ unexpected token
| |
| expected one of `...`, `..=`, `..`, `=>`, `if`, or `|` here
error: aborting due to previous error
```
With my proposed change it will show:
```
error: unexpected token `||` after pattern
--> test.rs:5:11
|
5 | 1 || 2 => println!("1 or 2"),
| ^^
|
= help: did you mean to use `|` to specify multiple patterns instead?
error: aborting due to previous error
```
Provide suggestion when trying to use method on numeric literal
New output:
```
error[E0688]: can't call method `powi` on ambiguous numeric type `{float}`
--> $DIR/method-on-ambiguous-numeric-type.rs:12:17
|
12 | let x = 2.0.powi(2);
| ^^^^
help: you must specify a concrete type for this numeric value, like `f32`
|
12 | let x = 2.0_f32.powi(2);
| ^^^^^^^
```
Previous output:
```
error[E0599]: no method named `powi` found for type `{float}` in the current scope
--> src/main.rs:12:17
|
12 | let x = 2.0.powi(2);
| ^^^^
|
= help: items from traits can only be used if the trait is in scope
help: the following trait is implemented but not in scope, perhaps add a `use` for it:
|
11 | use core::num::Float;
|
```
Fix#40985.
rustc: use {U,I}size instead of {U,I}s shorthands.
`Us`/`Is` come from a time when `us` and `is` were the literal suffixes that are now `usize` / `isize`.
r? @nikomatsakis
Reword reason for move note
On move errors, when encountering an enum variant, be more ambiguous and do not refer to the type on the cause note, to avoid referring to `(maybe as std::prelude::v1::Some).0`, and instead refer to `the value`.
Sidesteps part of the problem with #41962:
```
error[E0382]: use of partially moved value: `maybe`
--> file.rs:5:30
|
5 | if let Some(thing) = maybe {
| ----- ^^^^^ value used here after move
| |
| value moved here
= note: move occurs because the value has type `std::vec::Vec<bool>`, which does not implement the `Copy` trait
error[E0382]: use of moved value: `(maybe as std::prelude::v1::Some).0`
--> file.rs:5:21
|
5 | if let Some(thing) = maybe {
| ^^^^^ value moved here in previous iteration of loop
= note: move occurs because the value has type `std::vec::Vec<bool>`, which does not implement the `Copy` trait
error: aborting due to 2 previous errors
```
Previous discussion: #44360
r? @arielb1
NLL fixes
First, introduce pre-statement effects to dataflow to fix#46875. Edge dataflow effects might make that redundant, but I'm not sure of the best way to integrate them with liveness etc., and if this is a hack, this is one of the cleanest hacks I've seen.
And I want a small fix to avoid the torrent of bug reports.
Second, fix linking of projections to fix#46974
r? @pnkfelix
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.
Check all repr hints together when checking for mis-applied attributes
Fixes#47094
Besides fixing that bug, this change has a user-visible effect on the spans in the "incompatible repr hints" warning and another error: they now point at `foo` and/or `bar` in `repr(foo, bar)` instead of the whole attribute. This is sometimes more precise (e.g., `#[repr(C, packed)]` on an enum points at the `packed`) but sometimes not. I moved a compile-fail test to a ui test to illustrate how it now looks in the common case of only one attribute.
Fixes#47094
Besides fixing that bug, this change has a user-visible effect on the spans in the "incompatible repr hints" warning and another error: they now point at `foo` and/or `bar` in `repr(foo, bar)` instead of the whole attribute. This is sometimes more precise (e.g., `#[repr(C, packed)]` on an enum points at the `packed`) but sometimes not. I moved a compile-fail test to a ui test to illustrate how it now looks in the common case of only one attribute.
Reword trying to operate in immutable fields
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".
Re #35937.
Allow lifetimes in macros
This is a resurrection of PR #41927 which was a resurrection of #33135, which is intended to fix#34303.
In short, this allows macros_rules! to use :lifetime as a matcher to match 'lifetimes.
Still to do:
- [x] Feature gate
Add a tidy check for missing or too many trailing newlines.
I've noticed recently there are lots of review comments requesting to fix trailing newlines. If this is going to be an official style here, it's better to let the CI do this repetitive check.
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".
Pass correct span when lowering grouped imports
Solves incorrect diagnostics for unused or deprecated imports. Closes#46576.
Deprecated imports had an existing test which asserted the incorrect span.
That test has been corrected as part of this commit.
Implements RFC 1937: `?` in `main`
This is the first part of the RFC 1937 that supports new
`Termination` trait in the rust `main` function.
Thanks @nikomatsakis, @arielb1 and all other people in the gitter channel for all your help!
The support for doctest and `#[test]` is still missing, bu as @nikomatsakis said, smaller pull requests are better :)
Solves incorrect diagnostics for unused or deprecated imports. Closes#46576.
Deprecated imports had an existing test which asserted the incorrect span.
That test has been corrected as part of this commit.
Update check::cast::pointer_kind logic to new rustc
Make the match exhaustive, adding handling for anonymous types and
tuple coercions on the way.
Also, exit early when type errors are detected, to avoid error cascades
and the like.
Fixes#33690.
Fixes#46365.
Fixes#46880.
Convert warning about `*const _` to a future-compat lint
#46664 was merged before I could convert the soft warning about method lookup on `*const _` into a future-compatibility lint. This PR makes that change.
fixes#46837
tracking issue for the future-compatibility lint: #46906
r? @arielb1
