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.
Mention SliceConcatExt's stability in its docs
Just saw someone in IRC mention there being no stable way to join string slices! It isn't entirely clear from the rust documentation that `SliceConcatExt` is usable. While this is mentioned in https://doc.rust-lang.org/std/prelude/, the trait has nothing to indicate that it's currently usable if found via a documentation search.
The wording on this could probably be improved, but I'm hoping its better than nothing.
Minor cleanup for slice::Chunks and ChunksMut
This only renames the `size` field to `chunk_size` in one of them for consistency, and changes an assertion to check for != 0 instead of > 0.
Proc macro spans serve two mostly unrelated purposes: controlling name
resolution and controlling error messages. It can be useful to mix the
name resolution behavior of one span with the line/column error message
locations of a different span.
In particular, consider the case of a trait brought into scope within
the def_site of a custom derive. I want to invoke trait methods on the
fields of the user's struct. If the field type does not implement the
right trait, I want the error message to underline the corresponding
struct field.
Generating the method call with the def_site span is not ideal -- it
compiles and runs but error messages sadly always point to the derive
attribute like we saw with Macros 1.1.
```
|
4 | #[derive(HeapSize)]
| ^^^^^^^^
```
Generating the method call with the same span as the struct field's
ident or type is not correct -- it shows the right underlines but fails
to resolve to the trait in scope at the def_site.
```
|
7 | bad: std:🧵:Thread,
| ^^^^^^^^^^^^^^^^^^^^^^^^
```
The correct span for the method call is one that combines the def_site's
name resolution with the struct field's line/column.
```
field.span.resolved_at(Span::def_site())
// equivalently
Span::def_site().located_at(field.span)
```
Adding both because which one is more natural will depend on context.
Move static code outside of unciode.py.
This script in libstd_unicode is a mess and also contains code that shouldn't be output by a script, and instead just put in modules. So, this change does that.
Only bump error count when we are sure that the diagnostic is not a repetition
This ensures that if we emit the same diagnostic twice, the error count will
match the real number of errors shown to the user.
Fixes#42106
This is a followup of https://github.com/rust-lang/rust/pull/45603 as stated in https://github.com/rust-lang/rust/issues/42106#issuecomment-345218473.
This program, for example:
```rust
fn do_something<T>(collection: &mut Vec<T>) {
let _a = &collection;
collection.swap(1, 2);
}
fn main() {}
```
without this patch, produces:
```
error[E0502]: cannot borrow `*collection` as mutable because `collection` is also borrowed as immutable
--> $DIR/issue-42106.rs:13:5
|
12 | let _a = &collection;
| ---------- immutable borrow occurs here
13 | collection.swap(1, 2); //~ ERROR also borrowed as immutable
| ^^^^^^^^^^ mutable borrow occurs here
14 | }
| - immutable borrow ends here
error: aborting due to 2 previous errors
```
The number of errors do not match the diagnostics reported. This PR fixes this problem. The output is now in this case:
```
error[E0502]: cannot borrow `*collection` as mutable because `collection` is also borrowed as immutable
--> $DIR/issue-42106.rs:13:5
|
12 | let _a = &collection;
| ---------- immutable borrow occurs here
13 | collection.swap(1, 2); //~ ERROR also borrowed as immutable
| ^^^^^^^^^^ mutable borrow occurs here
14 | }
| - immutable borrow ends here
error: aborting due to previous error
```
Also, some other tests outputs have been adapted because their count didn't really match the number of diagnostics reported.
As an aside, an outdated comment has been removed (`Handler::cancel` will only call to the `Diagnostic::cancel` method and will not decrease the count of errors).
All tests are passing with this PR (`x.py test` is successful).
CloudABI doesn't make any distinction between TTYs and ordinary pipes.
While there, remove the redundant implementation used by Redox. It can
use the same stub function.
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.
Redox - Implement rename using new system call
This does the following:
- Update syscall module to match upstream
- Implement rename using new system call
- Make readlink and symlink utilize O_CLOEXEC
- Make readlink and symlink not leave dangling file handles on failure
SliceConcatExt's status as an unstable trait with stable methods is
documented in the compiler error for using it, and in
https://doc.rust-lang.org/std/prelude/, but it is not mentioned in the
trait itself.
Mentioning the methods can be used in stable rust today should help
users who are looking for a `join` method while working on stable rust.
