Turn `type_id` into a constant intrinsic
https://github.com/rust-lang/rust/issues/27745
The method `get_type_id` in `Any` is intended to support reflection. It's currently unstable in favor of using an associated constant instead. This PR makes the `type_id` intrinsic a constant intrinsic, the same as `size_of` and `align_of`, allowing `TypeId::of` to be a `const fn`, which will allow using an associated constant in `Any`.
Tweak presentation on lifetime trait mismatch
- On trait/impl method discrepancy, add label pointing at trait signature.
- Point only at method definition when referring to named lifetimes on lifetime mismatch.
- When the sub and sup expectations are the same, tweak the output to avoid repeated spans.
Fix#30790, CC #18759.
- On mismatch between impl and trait method, point at the trait
signature.
- Point only at the method signature instead of the whole body on
trait/impl mismatch errors.
When refering to named lifetime conflict, point only at the method's
signature span instead of the entire method.
When the expected and found sup and sub traces are the same, avoid
redundant text.
For E0277 on `for` loops, point at the "head" expression
When E0277's span points at a `for` loop, the actual issue is in the
element being iterated. Instead of pointing at the entire loop, point
only at the first line (when possible) so that the span ends in the
element for which E0277 was triggered.
Fix type inhabitedness check for arrays
Arrays of uninhabited types were considered to also be uninhabited if
their length had not been evaluated, causing unsoundness.
Fixes#47563.
r? @eddyb
Immovable generators
This adds support for immovable generators which allow you to borrow local values inside generator across suspension points. These are declared using a `static` keyword:
```rust
let mut generator = static || {
let local = &Vec::new();
yield;
local.push(0i8);
};
generator.resume();
// ERROR moving the generator after it has resumed would invalidate the interior reference
// drop(generator);
```
Region inference is no longer affected by the types stored in generators so the regions inside should be similar to other code (and unaffected by the presence of `yield` expressions). The borrow checker is extended to pick up the slack so interior references still result in errors for movable generators. This fixes#44197, #45259 and #45093.
This PR depends on [PR #44917 (immovable types)](https://github.com/rust-lang/rust/pull/44917), I suggest potential reviewers ignore the first commit as it adds immovable types.
Change the --unpretty flag to -Z unpretty
First PR 😄 !
-Z unpretty no longer requires -Z unstable-options.
Also, I mildly changed the syntax of the flag to match the other -Z flags. All uses of the flag take the form `unpretty=something` where something can either `string` or `string=string` (see the help messages of the CLI).
Fix#47395
r? @nikomatsakis EDIT: apparently rust-highfive doesn't see edits...
Properly pass down immutability info for thread-locals.
For thread-locals we call into cat_rvalue_node() to create a CMT
(Category, Mutability, Type) that always has McDeclared. This is
incorrect for thread-locals that don't have the 'mut' keyword; we should
use McImmutable there.
Extend cat_rvalue_node() to have an additional mutability parameter. Fix
up all the callers to make use of that function. Also extend one of the
existing unit tests to cover this.
Fixes: #47053
Implement repr(transparent)
r? @eddyb for the functional changes. The bulk of the PR is error messages and docs, might be good to have a doc person look over those.
cc #43036
cc @nox
Custom error when moving arg outside of its closure
When given the following code:
```rust
fn give_any<F: for<'r> FnOnce(&'r ())>(f: F) {
f(&());
}
fn main() {
let mut x = None;
give_any(|y| x = Some(y));
}
```
provide a custom error:
```
error: borrowed data cannot be moved outside of its closure
--> file.rs:7:27
|
6 | let mut x = None;
| ----- borrowed data cannot be moved into here...
7 | give_any(|y| x = Some(y));
| --- ^ cannot be moved outside of its closure
| |
| ...because it cannot outlive this closure
```
instead of the generic lifetime error:
```
error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements
--> file.rs:7:27
|
7 | give_any(|y| x = Some(y));
| ^
|
note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the body at 7:14...
--> file.rs:7:14
|
7 | give_any(|y| x = Some(y));
| ^^^^^^^^^^^^^^^
note: ...so that expression is assignable (expected &(), found &())
--> file.rs:7:27
|
7 | give_any(|y| x = Some(y));
| ^
note: but, the lifetime must be valid for the block suffix following statement 0 at 6:5...
--> file.rs:6:5
|
6 | / let mut x = None;
7 | | give_any(|y| x = Some(y));
8 | | }
| |_^
note: ...so that variable is valid at time of its declaration
--> file.rs:6:9
|
6 | let mut x = None;
| ^^^^^
```
Fix#45983.
Tweaks to invalid ctor messages
- Do not suggest using a constructor that isn't accessible
- Suggest the appropriate syntax (`()`/`{}` as appropriate)
- Add note when trying to use `Self` as a ctor
CC #22488, fix#47085.
It is currently allowed to perform such assignments when not making use
of NLL. NLL already does this right, but let's add a test in place to
ensure it never regresses.
-Z unpretty no longer requires -Z unstable-options. Also, I mildly
changed the syntax of the flag to match the other -Z flags. All uses of
the flag take the form `unpretty=something` where something can either
`string` or `string=string` (see the help messages of the CLI).
When given the following code:
```rust
fn give_any<F: for<'r> FnOnce(&'r ())>(f: F) {
f(&());
}
fn main() {
let mut x = None;
give_any(|y| x = Some(y));
}
```
provide a custom error:
```
error: borrowed data cannot be moved outside of its closure
--> file.rs:7:27
|
6 | let mut x = None;
| ----- binding declared outside of closure
7 | give_any(|y| x = Some(y));
| --- ^ cannot be assigned to binding outside of its closure
| |
| closure you can't escape
```
instead of the generic lifetime error:
```
error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements
--> file.rs:7:27
|
7 | give_any(|y| x = Some(y));
| ^
|
note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the body at 7:14...
--> file.rs:7:14
|
7 | give_any(|y| x = Some(y));
| ^^^^^^^^^^^^^^^
note: ...so that expression is assignable (expected &(), found &())
--> file.rs:7:27
|
7 | give_any(|y| x = Some(y));
| ^
note: but, the lifetime must be valid for the block suffix following statement 0 at 6:5...
--> file.rs:6:5
|
6 | / let mut x = None;
7 | | give_any(|y| x = Some(y));
8 | | }
| |_^
note: ...so that variable is valid at time of its declaration
--> file.rs:6:9
|
6 | let mut x = None;
| ^^^^^
```
