Remove `ObsoleteInPlace`
The in place syntax has been deprecated for over a year. As it is, this is accumulated cruft: the error messages are unlikely to be helpful any more and it conflicts with some useful syntax (e.g. const generics in some instances).
It may be that removing `Token::LArrow` is backwards-incompatible. We should do a crater run to check.
cc @eddyb
Borrowck error reporting cleanup
* Don't show variables created by desugarings in borrowck errors
* Move "conflict error" reporting to it's own module, so that `error_reporting` contains only common error reporting methods.
* Remove unused `ScopeTree` parameter.
r? @pnkfelix
tweak discriminant on non-nullary enum diagnostic
Adds notes pointing at the non-nullary variants, and uses "custom
discriminant" language to be consistent with the Reference.
Fixes#61039.
r? @estebank
Add basic CDB support to debuginfo compiletest s, to help catch `*.natvis` regressions, like those fixed in #60687.
First draft, feedback welcome.
Several Microsoft debuggers (VS, VS Code, WinDbg, CDB, ...) consume the `*.natvis` files we embed into rust `*.pdb` files. While this only tests CDB, that test coverage should help for all of them.
# Changes
## src\bootstrap
- test.rs: Run CDB debuginfo tests on MSVC targets
## src\test\debuginfo
- issue-13213.rs: CDB has trouble with this, skip for now (newly discovered regression?)
- pretty-std.rs: Was ignored, re-enable for CDB only to start with, add CDB tests.
- should-fail.rs: Add CDB tests.
## src\tools\compiletest:
- Added "-cdb" option
- Added Mode::DebugInfoCdb ("debuginfo-cdb")
- Added run_debuginfo_cdb_test[_no_opt]
- Renamed Mode::DebugInfoBoth -> DebugInfoGdbLldb ("debuginfo-gdb+lldb") since it's no longer clear what "Both" means.
- Find CDB at the default Win10 SDK install path "C:\Program Files (x86)\Windows Kits\10\Debugger\\*\cdb.exe"
- Ignore CDB tests if CDB not found.
# Issues
- `compute_stamp_hash`: not sure if there's any point in hashing `%ProgramFiles(x86)%`
- `OsString` lacks any `*.natvis` entries (would be nice to add in a followup changelist)
- DSTs (array/string slices) which work in VS & VS Code fail in CDB.
- I've avoided `Mode::DebugInfoAll` as 3 debuggers leads to pow(2,3)=8 possible combinations.
# Reference
CDB is not part of the base Visual Studio install, but can be added via the Windows 10 SDK:
https://developer.microsoft.com/en-us/windows/downloads/windows-10-sdk
Installing just "Debugging Tools for Windows" is sufficient.
CDB appears to already be installed on appveyor CI, where this changelist can find it, based on it's use here:
0ffc573110/appveyor.yml (L227)
CDB commands and command line reference:
https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/debugger-reference
syntax: Continue refactoring literals
A follow up to https://github.com/rust-lang/rust/pull/60679.
a2fd002bd5: Similarly to `EscapeError`, literal parsing now produces a `LitError`.
This way we can get rid of `diag: Option<(Span, &Handler)>` in interfaces while leaving attr/mod alone.
d9516d1120: Gathers all components of a literal token in a single struct.
Make -Zemit-artifact-notifications also emit the artifact type
This is easier for tooling to handle than trying to reverse-engineer the type from the filename extension. The field name and value is intended to reflect the `--emit` command-line option.
Related issues https://github.com/rust-lang/rust/issues/60988https://github.com/rust-lang/rust/issues/58465
cc @alexcrichton
Add match arm scopes and other scope fixes
* Add drop and lint scopes for match arms.
* Lint attributes are now respected on match arms.
* Make sure we emit a StorageDead if we diverge when initializing a temporary.
* Adjust MIR pretty printing of scopes for locals.
* Don't generate duplicate lint scopes for `let statements`.
* Add some previously missing fake borrows for matches.
closes#46525
cc @rust-lang/compiler
Always try to project predicates when finding auto traits in rustdoc
Fixes#60726
Previous, AutoTraitFinder would only try to project predicates when the
predicate type contained an inference variable. When finding auto
traits, we only project to try to unify inference variables - we don't
otherwise learn any new information about the required bounds.
However, this lead to failing to properly generate a negative auto trait
impl (indicating that a type never implements a certain auto trait) in
the following unusual scenario:
In almost all cases, a type has an (implicit) negative impl of an auto
trait due some other type having an explicit *negative* impl of that
auto trait. For example:
struct MyType<T> {
field: *const T
}
has an implicit 'impl<T> !Send for MyType<T>', due to the explicit
negative impl (in libcore) 'impl<T: ?Sized> !Send for *const T'.
However, as exposed by the 'abi_stable' crate, this isn't always the
case. This minimzed example shows how a type can never implement
'Send', due to a projection error:
```
pub struct True;
pub struct False;
pub trait MyTrait {
type Project;
}
pub struct MyStruct<T> {
field: T
}
impl MyTrait for u8 {
type Project = False;
}
unsafe impl<T> Send for MyStruct<T>
where T: MyTrait<Project=True> {}
pub struct Wrapper {
inner: MyStruct<u8>
}
```
In this example, `<u8 as MyTrait>::Project == True'
must hold for 'MyStruct<u8>: Send' to hold.
However, '<u8 as MyTrait>::Project == False' holds instead
To properly account for this unusual case, we need to call
'poly_project_and_unify' on *all* predicates, not just those with
inference variables. This ensures that we catch the projection error
that occurs above, and don't incorrectly determine that 'Wrapper: Send'
holds.
This allows types like Option<NonZeroU8> to be used in FFI without triggering the improper_ctypes lint. This works by changing the is_repr_nullable_ptr function to consider an enum E to be FFI-safe if:
- E has no explicit #[repr(...)].
- It only has two variants.
- One of those variants is empty (meaning it has no fields).
- The other variant has only one field.
- That field is one of the following:
- &T
- &mut T
- extern "C" fn
- core::num::NonZero*
- core::ptr::NonNull<T>
- #[repr(transparent)] struct wrapper around one of the types in this list.
- The size of E and its field are both known and are both the same size (implying E is participating in the nonnull optimization).
Ban multi-trait objects via trait aliases
Obviously, multi-trait objects are not normally supported, so they should not be supported via trait aliases.
This has been factored out from the previous PR https://github.com/rust-lang/rust/pull/55994 (see point 1).
r? @Centril
CC @nikomatsakis
------------------
### RELNOTES:
We now allow `dyn Send + fmt::Debug` with equivalent semantics to `dyn fmt::Debug + Send`.
That is, the order of the mentioned traits does not matter wrt. principal/not-principal traits.
This is a small change that might deserve a mention in the blog post because it is a language change but most likely not.
See ce2ee305f9/src/test/ui/traits/wf-trait-object-reverse-order.rs.
// @Centril
Preserve local scopes in generator MIR
Part of #52924, depended upon by the generator layout optimization #60187.
This PR adds `StorageDead` statements in more places in generators, so we can see when non-`Drop` locals have gone out of scope and recover their storage.
The reason this is only done for generators is compiler performance. See https://github.com/rust-lang/rust/pull/60187#issuecomment-485637811 for what happens when we do this for all functions.
For `Drop` locals, we modify the `MaybeStorageLive` analysis to use `drop` to indicate that storage is no longer live for the local. Once `drop` returns or unwinds to our function, we implicitly assume that the local is `StorageDead`.
Instead of using `drop`, it is possible to emit more `StorageDead` statements in the MIR for `Drop` locals so we can handle all locals the same. I am fine with doing it that way, but this was the simplest approach for my purposes. It is also likely to be more performant.
r? @Zoxc (feel free to reassign)
cc @cramertj @eddyb @RalfJung @rust-lang/wg-async-await
Fix intra-doc link resolution failure on re-exporting libstd
Currently, re-exporting libstd items as below will [occur a lot of failures](https://gist.github.com/taiki-e/e33e0e8631ef47f65a74a3b69f456366).
```rust
pub use std::*;
```
Until the underlying issue (#56922) fixed, we can fix that so they don't propagate to downstream crates.
Related: https://github.com/rust-lang/rust/pull/56941 (That PR fixed failures that occur when re-exporting from libcore to libstd.)
r? @QuietMisdreavus
