Union fields may now never have a type with attached destructor.
This for example allows unions to use arbitrary field types only by
wrapping
them in ManuallyDrop.
The stable rule remains, that union fields must be Copy. We use the new
rule for the `untagged_union` feature.
See RFC 2514.
Note for ui tests:
We can't test move out through Box's deref-move since we can't
have a Box in a union anymore.
Improve message when attempting to instantiate tuple structs with private fields
Fixes#58017, fixes#39703.
```
error[E0603]: tuple struct `Error` is private
--> main.rs:22:16
|
2 | pub struct Error(usize, pub usize, usize);
| ----- ----- field is private
| |
| field is private
...
22 | let x = a::Error(3, 1, 2);
| ^^^^^
|
= note: a tuple struct constructor is private if any of its fields is private
```
Add llvm.sideeffect to potential infinite loops and recursions
LLVM assumes that a thread will eventually cause side effect. This is
not true in Rust if a loop or recursion does nothing in its body,
causing undefined behavior even in common cases like `loop {}`.
Inserting llvm.sideeffect fixes the undefined behavior.
As a micro-optimization, only insert llvm.sideeffect when jumping back
in blocks or calling a function.
A patch for LLVM is expected to allow empty non-terminate code by
default and fix this issue from LLVM side.
https://github.com/rust-lang/rust/issues/28728
**UPDATE:** [Mentoring instructions here](https://github.com/rust-lang/rust/pull/59546#issuecomment-515072429) to unstall this PR
Ignore `ExprKind::DropTemps` for some ref suggestions
Introduce `Expr::peel_drop_temps()` to ignore `ExprKind::DropTemps` for suggestions that depend on the `ExprKind` for accuracy.
typeck: prohibit foreign statics w/ generics
Fixes#65035 and fixes#65025.
This PR modifies resolve to disallow foreign statics that have
generics.
`improper_ctypes` is not written to support type parameters, as these
are normally disallowed before the lint is run. Thus, type parameters in
foreign statics must be prohibited before the lint.
The only other case where this *could* have occured is in functions,
but typeck prohibits this with a "foreign items may not have type
parameters" error - a similar error did not exist for statics, because
statics cannot have type parameters, but they can use any
type parameters that are in scope (which isn't the case for functions).
Warn if include macro fails to include entire file
This currently introduces an error, mainly because that was just simpler, and I'm not entirely certain if we can introduce a lint without an RFC and such.
This is primarily to get feedback on the approach and overall aim -- in particular, do we think this is helpful? If so, we probably will need lang-team sign off and decide if it should be an error (as currently introduced by this PR), a lint, or a warning.
r? @petrochenkov
cc https://github.com/rust-lang/rust/issues/35560
This commit modifies resolve to disallow foreign statics that use
parent generics.
`improper_ctypes` is not written to support type parameters, as these
are normally disallowed before the lint is run. Thus, type parameters in
foreign statics must be prohibited before the lint.
The only other case where this *could* have occured is in functions,
but typeck prohibits this with a "foreign items may not have type
parameters" error - a similar error did not exist for statics, because
statics cannot have type parameters, but they can use any
type parameters that are in scope (which isn't the case for functions).
Signed-off-by: David Wood <david@davidtw.co>
- The attribute is behind a feature gate.
- Error if both #[naked] and #[track_caller] are applied to the same function.
- Error if #[track_caller] is applied to a non-function item.
- Error if ABI is not "rust"
- Error if #[track_caller] is applied to a trait function.
Error codes and descriptions are pending.
