When there's a lifetime mismatch between an argument with an anonymous
lifetime being returned in a method with a return type that has a named
lifetime, show specialized lifetime error pointing at argument with a
hint to give it an explicit lifetime matching the return type.
```
error[E0621]: explicit lifetime required in the type of `other`
--> file2.rs:21:21
|
17 | fn bar(&self, other: Foo) -> Foo<'a> {
| ----- consider changing the type of `other` to `Foo<'a>`
...
21 | other
| ^^^^^ lifetime `'a` required
```
Follow up to #44124 and #42669.
Improve display of error E0308
Ref. Forgetting to call a variant constructor causes a confusing error message #35241.
This PR modifies [`note_type_err`](b7041bfab3/src/librustc/infer/error_reporting/mod.rs (L669-L674)) to display a `help` message when a `TyFnPtr` or `TyFnDef` are found and the return type, of the function or function pointer, is the same as the type that is expected.
The output of compiling
```rust
struct Foo(u32);
fn test() -> Foo { Foo }
fn main() {}
```
is now
```bash
$ rustc src/test/ui/issue-35241.rs
error[E0308]: mismatched types
--> src/test/ui/issue-35241.rs:13:20
|
13 | fn test() -> Foo { Foo }
| --- ^^^ expected struct `Foo`, found fn item
| |
| expected `Foo` because of return type
|
= help: did you mean `Foo { /* fields */ }`?
= note: expected type `Foo`
found type `fn(u32) -> Foo {Foo::{{constructor}}}`
error: aborting due to previous error
```
Bring back slice::ref_slice as slice::from_ref.
These functions were deprecated and removed in 1.5, but such simple
functionality shouldn't require using unsafe code, and it isn't
cluttering libstd too much.
The original removal was quite contentious (see #27774), since then
we've had precedent for including such nuggets of functionality (see rust-lang/rfcs#1789),
and @nikomatsakis has provided a lot of use cases in https://github.com/rust-lang/rfcs/pull/1789#issuecomment-314640034.
Hence this PR.
I'm not too sure what to do with stability, feel free to correct me.
It seems pointless to go through stabilization for these functions though.
cc @aturon
enable non-lexical lifetimes in the MIR borrow checker
This PR, joint work with @spastorino, fills out the NLL infrastructure and integrates it with the borrow checker. **Don't get too excited:** it includes still a number of hacks (the subtyping code is particularly hacky). However, it *does* kinda' work. =)
The final commit demonstrates this by including a test that -- with both the AST borrowck and MIR borrowck -- reports an error by default. But if you pass `-Znll`, you only get an error from the AST borrowck, demonstrating that the integration succeeds:
```
struct MyStruct {
field: String
}
fn main() {
let mut my_struct = MyStruct { field: format!("Hello") };
let value = &my_struct.field;
if value.is_empty() {
my_struct.field.push_str("Hello, world!");
//~^ ERROR cannot borrow (Ast)
}
}
```
incr.comp.: Implement compiler diagnostic persistence.
This PR implements storing and loading diagnostics that the compiler generates and thus allows for emitting warnings during incremental compilation without actually re-evaluating the thing the warning originally came from. It also lays some groundwork for storing and loading type information and MIR in the incr. comp. cache.
~~It is still work in progress:~~
- ~~There's still some documentation to be added.~~
- ~~The way anonymous queries are handled might lead to duplicated emissions of warnings. Not sure if there is a better way or how frequent such duplication would be in practice.~~
Diagnostic message duplication is addressed separately in #45519.
r? @nikomatsakis
Suggest renaming import if names clash
Closes https://github.com/rust-lang/rust/issues/32354.
The output for the example in the issue looks like this:
```
~/p/local-rust-dev-testing ❯❯❯ cargo +local-s1 build
Compiling local-rust-dev-testing v0.1.0 (file:///home/cldfire/programming_projects/local-rust-dev-testing)
error[E0252]: the name `ConstructorExtension` is defined multiple times
--> src/main.rs:49:5
|
48 | use extension1::ConstructorExtension;
| -------------------------------- previous import of the trait `ConstructorExtension` here
49 | use extension2::ConstructorExtension;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `ConstructorExtension` reimported here
|
= note: `ConstructorExtension` must be defined only once in the type namespace of this module
help: You can use `as` to change the binding name of the import
|
49 | use extension2::ConstructorExtension as OtherConstructorExtension;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
```
This is my first PR that touches the compiler in any way, so if there's something else I need to do here (e.g. add a test), please let me know :).
More fixes for x86_64-unknown-linux-gnux32
This update libc (all libc testing are passing) and fixes NR_GETRANDOM.
Fix all but one run-pass test (lto-unwind.rs, see https://github.com/rust-lang/rust/issues/45416)
edit and fix bad spacing of inner-attribute-not-allowed note
This multiline string literal was missing a backslash, leaving an awkward
newline and 35 spaces in the middle of the message.
But while we're here, the existing message seems kind of long in comparison to
similar notes: to cut it down, we excise the mentions of doc comments, which
seems sensible because we know that this erroneous attribute is not a doc
comment (notice the `is_sugared_doc: false` at the end of the function; if it
had been a doc comment, that error would get set in the `token::DocComment`
match branch of `parse_outer_attributes`).
Optimize some span operations
Do not decode span data twice/thrice/etc unnecessarily.
Applied to stable hashing and all methods in `impl Span`.
Follow up to https://github.com/rust-lang/rust/pull/44646
r? @michaelwoerister
remove the `T: Sync` requirement for `RwLock<T>: Send`
That requirement makes sense for containers like `Arc` that don't
uniquely own their contents, but `RwLock` is not one of those.
This restriction was added in 380d23b5d4, but it's not clear why. @hniksic
and I [were discussing this on reddit](https://www.reddit.com/r/rust/comments/763o7r/blog_posts_introducing_lockfree_rust_comparing/dobcvbm/). I might be totally wrong about this change being sound, but I'm super curious to find out :)
Implement TryFrom<&[T]> for &[T; N]
There are many cases where a buffer with a static compile-time size is preferred over a slice with a dynamic size. This allows for performing a checked conversion from `&[T]` to `&[T; N]`. This may also lead to compile-time optimizations involving `[T; N]` such as loop unrolling.
This is my first PR to Rust, so I'm not sure if discussion of this change should happen here or does it need its own RFC? I figured these changes would be a subset of #33417.
The macro now takes a format string. It no longer defaults to using the
type name. Didn't seem worth going through contortions to maintain. I
also changed most of the debug formats to be `foo[N]` instead of `fooN`.
Also, factor out `do_mir_borrowck`, which is the code that actually
performs the MIR borrowck from within the scope of an inference context.
This change should be a pure refactoring.
This will be important in next commit, since the input types will be
tagged not with `'gcx` but rather `'tcx`. Also, using the region-erased,
lifted types enables better caching.
