Given a file:
```rust
enum Fruit {
Apple(i64),
Orange(i64),
}
fn should_return_fruit() -> Apple {
Apple(5)
}
```
Provide the following output:
```rust
error[E0412]: cannot find type `Apple` in this scope
--> file.rs:16:29
|
16 | fn should_return_fruit() -> Apple {
| ^^^^^ not found in this scope
|
help: there is an enum variant `Fruit::Apple`, did you mean to use `Fruit`?
--> file.rs:12:5
|
12 | Apple(i64),
| ^^^^^^^^^^
error[E0425]: cannot find function `Apple` in this scope
--> file.rs:17:5
|
17 | Apple(5)
| ^^^^^ not found in this scope
|
= help: possible candidate is found in another module, you can import it into scope:
`use Fruit::Apple;`
```
Allow `use` macro imports to shadow global macros
Terminology:
- global scope: builtin macros, macros from the prelude, `#[macro_use]`, or `#![plugin(..)]`.
- legacy scope: crate-local `macro_rules!`.
- modern scope: `use` macro imports, `macro` (once implemented).
Today, the legacy scope can shadow the global scope (modulo RFC 1560 expanded shadowing restrictions). However, the modern scope cannot shadow or be shadowed by either the global or legacy scopes, leading to ambiguity errors.
This PR allows the modern scope to shadow the global scope (subject to some restrictions).
More specifically, a name in the global scope is as shadowable as a glob import in the module `self`. In other words, we imagine a special, implicit glob import in each module item:
```rust
mod foo {
#[lexical_only] // Not accessible via `foo::<name>`, like pre-RFC 1560 `use` imports.
#[shadowable_by_legacy_scope] // for back-compat
use <global_macros>::*;
}
```
r? @nrc
This commit deletes the internal liblog in favor of the implementation that
lives on crates.io. Similarly it's also setting a convention for adding crates
to the compiler. The main restriction right now is that we want compiler
implementation details to be unreachable from normal Rust code (e.g. requires a
feature), and by default everything in the sysroot is reachable via `extern
crate`.
The proposal here is to require that crates pulled in have these lines in their
`src/lib.rs`:
#![cfg_attr(rustbuild, feature(staged_api, rustc_private))]
#![cfg_attr(rustbuild, unstable(feature = "rustc_private", issue = "27812"))]
This'll mean that by default they're not using these attributes but when
compiled as part of the compiler they do a few things:
* Mark themselves as entirely unstable via the `staged_api` feature and the
`#![unstable]` attribute.
* Allow usage of other unstable crates via `feature(rustc_private)` which is
required if the crate relies on any other crates to compile (other than std).
Forbid conflicts between macros 1.0 exports and macros 2.0 exports
This PR forbids for conflicts between `#[macro_export]`/`#[macro_reexport]` macro exports and `pub use` macro exports. For example,
```rust
// crate A:
pub use macros::foo;
//^ This is allowed today, will be forbidden by this PR.
// crate B:
extern crate A; // This triggers a confusing error today.
use A::foo; // This could refer to refer to either macro export in crate A.
```
r? @nrc
Group "missing variable bind" spans in `or` matches and clarify wording
for the two possible cases: when a variable from the first pattern is
not in any of the subsequent patterns, and when a variable in any of the
other patterns is not in the first one.
Before:
```
error[E0408]: variable `a` from pattern #1 is not bound in pattern #2
--> file.rs:10:23
|
10 | T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
| ^^^^^^^^^^^ pattern doesn't bind `a`
error[E0408]: variable `b` from pattern #2 is not bound in pattern #1
--> file.rs:10:32
|
10 | T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
| ^ pattern doesn't bind `b`
error[E0408]: variable `a` from pattern #1 is not bound in pattern #3
--> file.rs:10:37
|
10 | T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
| ^^^^^^^^ pattern doesn't bind `a`
error[E0408]: variable `d` from pattern #1 is not bound in pattern #3
--> file.rs:10:37
|
10 | T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
| ^^^^^^^^ pattern doesn't bind `d`
error[E0408]: variable `c` from pattern #3 is not bound in pattern #1
--> file.rs:10:43
|
10 | T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
| ^ pattern doesn't bind `c`
error[E0408]: variable `d` from pattern #1 is not bound in pattern #4
--> file.rs:10:48
|
10 | T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
| ^^^^^^^^ pattern doesn't bind `d`
error: aborting due to 6 previous errors
```
After:
```
error[E0408]: variable `a` is not bound in all patterns
--> file.rs:20:37
|
20 | T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => {
intln!("{:?}", a); }
| - ^^^^^^^^^^^ ^^^^^^^^ - variable
t in all patterns
| | | |
| | | pattern doesn't bind `a`
| | pattern doesn't bind `a`
| variable not in all patterns
error[E0408]: variable `d` is not bound in all patterns
--> file.rs:20:37
|
20 | T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => {
intln!("{:?}", a); }
| - - ^^^^^^^^ ^^^^^^^^ pattern
esn't bind `d`
| | | |
| | | pattern doesn't bind `d`
| | variable not in all patterns
| variable not in all patterns
error[E0408]: variable `b` is not bound in all patterns
--> file.rs:20:37
|
20 | T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => {
intln!("{:?}", a); }
| ^^^^^^^^^^^ - ^^^^^^^^ ^^^^^^^^ pattern
esn't bind `b`
| | | |
| | | pattern doesn't bind `b`
| | variable not in all patterns
| pattern doesn't bind `b`
error[E0408]: variable `c` is not bound in all patterns
--> file.rs:20:48
|
20 | T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => {
intln!("{:?}", a); }
| ^^^^^^^^^^^ ^^^^^^^^^^^ - ^^^^^^^^ pattern
esn't bind `c`
| | | |
| | | variable not in all
tterns
| | pattern doesn't bind `c`
| pattern doesn't bind `c`
error: aborting due to 4 previous errors
```
* Have only one presentation for binding consistency errors
* Point to same binding in multiple patterns when possible
* Check inconsistent bindings in all arms
* Simplify wording of diagnostic message
* Sort emition and spans of binding errors for deterministic output
This commit searchs modules for macro suggestions.
It also removes imported macro_rules from macro_names,
and adds more corner case checks for which macros
should be suggested in specific contexts.
Don't suggest to use things which weren't found either
Fixes#38054
The best code I can come up with, suggestions are welcome.
Basically, removing ```. Did you mean to use `DoesntExist1`?``` in the code below, because it is useless.
```rust
error[E0432]: unresolved import `DoesntExist1`
--> src/lib.rs:1:5
|
1 | use DoesntExist1;
| ^^^^^^^^^^^^ no `DoesntExist1` in the root
error[E0432]: unresolved import `DoesntExist2`
--> src/lib.rs:2:5
|
2 | use DoesntExist2;
| ^^^^^^^^^^^^ no `DoesntExist2` in the root. Did you mean to use `DoesntExist1`?
```
