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.
minimize the rust-std component
This changes the `rust-std` dist component to only include the artifacts of compiling the `libstd` step, as listed in `.libstd.stamp`. This does include `test` and `proc-macro` as well. The remaining _unstable_ libraries that are built as part of `rustc` are packaged into a new `rustc-dev` component, intended for use in the development of closely related tools (clippy, miri, rls).
Here are the component sizes from the [try build](https://dev-static.rust-lang.org/dist/2019-10-07/index.html):
| Name | Size
| --- | ---
| rust-std-nightly-x86_64-unknown-linux-gnu.tar.gz | 23.94 MiB
| rust-std-nightly-x86_64-unknown-linux-gnu.tar.xz | 17.4 MiB
| rustc-dev-nightly-x86_64-unknown-linux-gnu.tar.gz | 182.03 MiB
| rustc-dev-nightly-x86_64-unknown-linux-gnu.tar.xz | 157.91 MiB
Fixes#61978Fixes#62486
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
Revert "Make `into` schedule drop for the destination"
This was a *very* large perf regression in some cases. I'll undo the revert once I have time to avoid the regression.
self-profiling: Add events for everything except trait selection.
This is the followup PR to https://github.com/rust-lang/rust/pull/64840.
Trait selection events are still missing (at least those not covered by regular queries).
r? @wesleywiser (or @Mark-Simulacrum if @wesleywiser is not available at the moment)
Implement (HashMap) Entry::insert as per #60142
Implementation of `Entry::insert` as per @SimonSapin's comment on #60142. This requires a patch to hashbrown:
```diff
diff --git a/src/rustc_entry.rs b/src/rustc_entry.rs
index fefa5c3..7de8300 100644
--- a/src/rustc_entry.rs
+++ b/src/rustc_entry.rs
@@ -546,6 +546,32 @@ impl<'a, K, V> RustcVacantEntry<'a, K, V> {
let bucket = self.table.insert_no_grow(self.hash, (self.key, value));
unsafe { &mut bucket.as_mut().1 }
}
+
+ /// Sets the value of the entry with the RustcVacantEntry's key,
+ /// and returns a RustcOccupiedEntry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::RustcEntry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// if let RustcEntry::Vacant(v) = map.rustc_entry("poneyland") {
+ /// let o = v.insert_and_return(37);
+ /// assert_eq!(o.get(), &37);
+ /// }
+ /// ```
+ #[inline]
+ pub fn insert_and_return(self, value: V) -> RustcOccupiedEntry<'a, K, V> {
+ let bucket = self.table.insert_no_grow(self.hash, (self.key, value));
+ RustcOccupiedEntry {
+ key: None,
+ elem: bucket,
+ table: self.table
+ }
+ }
}
impl<K, V> IterMut<'_, K, V> {
```
This is also only an implementation for HashMap. I tried implementing for BTreeMap, but I don't really understand BTreeMap's internals and require more guidance on implementing the equivalent `VacantEntry::insert_and_return` such that it returns an `OccupiedEntry`. Notably, following the original PR's modifications I end up needing a `Handle<NodeRef<marker::Mut<'_>, _, _, marker::LeafOrInternal>, _>` while I only have a `Handle<NodeRef<marker::Mut<'_>, _, _, marker::Internal>, _>` and don't know how to proceed.
(To be clear, I'm not asking for guidance right now; I'd be happy getting only the HashMap implementation — the subject of this PR — reviewed and ready, and leave the BTreeMap implementation for a latter 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.
