Add or_default to Entry APIs
As argued for in #44324, this PR adds a new `or_default` method to the various `Entry` APIs (currently just for `BTreeMap` and `HashMap`) when `V: Default`. This method is effectively a shorthand for `or_insert_with(Default::default)`.
Additional traits for std::mem::ManuallyDrop
The first commit adds `Clone` and `Copy` trait implementations for `ManuallyDrop`. Although `Drop` and `Copy` cannot be used together, this may be useful for generics.
The second commit adds implementations common traits. I do not think this is necessary, as they could be implemented in a wrapper type outside the standard library, but it would make `ManuallyDrop` more convenient to use.
Evaluate fixed-length array length expressions lazily.
This is in preparation for polymorphic array lengths (aka `[T; T::A]`) and const generics.
We need deferred const-evaluation to break cycles when array types show up in positions which require knowing the array type to typeck the array length, e.g. the array type is in a `where` clause.
The final step - actually passing bounds in scope to array length expressions from the parent - is not done because it still produces cycles when *normalizing* `ParamEnv`s, and @nikomatsakis' in-progress lazy normalization work is needed to deal with that uniformly.
However, the changes here are still useful to unlock work on const generics, which @EpicatSupercell manifested interest in, and I might be mentoring them for that, but we need this baseline first.
r? @nikomatsakis cc @oli-obk
rustbuild: Fix a distribution bug with rustdoc
Apparently `File::create` was called when there was an existing hard link or the
like, causing an existing file to get accidentally truncated!
Closes#44487
Fix regression in promotion of rvalues referencing a static
This commit makes librustc_passes::consts::CheckCrateVisitor properly
mark expressions as promotable if they reference a static, as it's
perfectly fine for one static to reference another. It fixes a
regression that prevented a temporary rvalue from referencing a static
if it was itself declared within a static.
Prior to commit https://github.com/rust-lang/rust/commit/b8c05fe90bc,
`region::ScopeTree` would only register a 'terminating scope' for function
bodies. Thus, while rvalues in a static that referenced a static would be marked
unpromotable, the lack of enclosing scope would cause
mem_categorization::MemCategorizationContext::cat_rvalue_node
to compute a 'temporary scope' of `ReStatic`. Since this had the same
effect as explicitly selecting a scope of `ReStatic`
due to the rvalue being marked by CheckCrateVisitor as promotable,
no issue occurred.
However, commit https://github.com/rust-lang/rust/commit/b8c05fe90bc
made ScopeTree unconditionally register a 'terminating scope'
Since mem_categorization would now compute a non-static 'temporary scope', the
aforementioned rvalues would be erroneously marked as living for too
short a time.
By fixing the behavior of CheckCrateVisitor, this commit avoids changing
mem_categorization's behavior, while ensuring that temporary values in
statics are still allowed to reference other statics.
Fixes issue #44373
Apparently `File::create` was called when there was an existing hard link or the
like, causing an existing file to get accidentally truncated!
Closes#44487
This'll allow us to reconstruct query parameters purely from the `DepNode`
they're associated with. Some queries could move straight to `HirId` but others
that don't always have a correspondance between `HirId` and `DefId` moved to
two-level maps where the query operates over a `DefIndex`, returning a map,
which is then keyed off `ItemLocalId`.
Closes#44414
Add `TargetOptions::min_global_align`, with s390x at 16-bit
The SystemZ `LALR` instruction provides PC-relative addressing for globals,
but only to *even* addresses, so other compilers make sure that such
globals are always 2-byte aligned. In Clang, this is modeled with
`TargetInfo::MinGlobalAlign`, and `TargetOptions::min_global_align` now
serves the same purpose for rustc.
In Clang, the only targets that set this are SystemZ, Lanai, and NVPTX, and
the latter two don't have targets in rust master.
Fixes#44411.
r? @eddyb
Fix sanitizer tests on buggy kernels
Travis recently pushed an update to the Linux environments, namely the kernels
that we're running on. This in turn caused some of the sanitizer tests we run to
fail. We also apparently weren't the first to hit these failures! Detailed in
google/sanitizers#837 these tests were failing due to a specific commit in the
kernel which has since been backed out, but for now work around the buggy kernel
that's deployed on Travis and eventually we should be able to remove these
flags.
Properly detect overflow in Instance ± Duration.
Fix#44216.
Fix#42622
The computation `Instant::now() + Duration::from_secs(u64::max_value())` now panics. The call `receiver.recv_timeout(Duration::from_secs(u64::max_value()))`, which involves such time addition, will also panic.
The reason #44216 arises is because of an unchecked cast from `u64` to `i64`, making the duration equivalent to -1 second.
Note that the current implementation is over-conservative, since e.g. (-2⁶²) + (2⁶³) is perfectly fine for an `i64`, yet this is rejected because (2⁶³) overflows the `i64`.
Extend E0623 for LateBound and EarlyBound Regions
This is a fix for #43882
```
fn foo<'a,'b>(x: &mut Vec<&'a u8>, y: &'b u8) {
x.push(y);
}
```
now gives
```
error[E0623]: lifetime mismatch
--> $DIR/ex3-both-anon-regions-latebound-regions.rs:12:12
|
11 | fn foo<'a,'b>(x: &mut Vec<&'a u8>, y: &'b u8) {
| ------ ------ these two types are declared with different lifetimes...
12 | x.push(y);
| ^ ...but data from `y` flows into `x` here
```
cc @nikomatsakis @arielb1
Please ignore the second commit. It will be merged in a separate PR.
std:🧵:LocalKey: Document limitation with initializers
Document that if a `LocalKey`'s initializer recursively depends on itself, initialization will result in infinite recursion.
Use memalign instead of posix_memalign for Solaris
As pointed out in https://github.com/rust-lang/libc/commit/deb61c8,
Solaris 10 does not support posix_memalign.
Use memalign for all Solaris versions instead.
With this change applied I am able to cross-build rustc for Solaris 10.
Expect pipe symbol after closure parameter list
Fixes#44021.
---
Originally, the parser just called `bump` to discard following token after parsing closure parameter list, because it assumes `|` is following. However, the following code breaks the assumption:
```rust
struct MyStruct;
impl MyStruct {
fn f() {|x, y}
}
```
Here, the parameter list is `x, y` and the following token is `}`. The parser discards `}`, and then we have a curly bracket mismatch.
Indeed, this code has a syntax error. On current nightly, the compiler emits an syntax error, but with incorrect message and span, followed by an ICE.
```
error: expected expression, found `}`
--> 44021.rs:4:1
|
4 | }
| ^
error: internal compiler error: unexpected panic
```
Even worse, on current stable(1.20.0), the compiler falls into an infinite loop.
This pull request fixes this problem. Now the compiler emits correct error message and span, and does not ICE.
```
error: expected one of `:`, `@`, or `|`, found `}`
--> 44021.rs:3:20
|
3 | fn foo() {|x, y}
| ^ expected one of `:`, `@`, or `|` here
```
rustc: Separately feature gate repr(i128)
Brought up during the discussion of #35118, the support for this is still
somewhat buggy and so stabilization likely wants to be considered independently
of the type itself.
Use rvalue promotion to 'static instead of static items.
Fixes#44240. Among other things, in crates that do a lot of formatting, this could reduce the number of items, although I haven't measured the performance benefits. If there's a codegen slowdown, that should IMO be solved by caching the output of miri, *not* by using `static`.
r? @alexcrichton
rustc: Remove `DepGraph` handling from rustc_metadata
This should now be entirely tracked through queries, so no need to have a
`DepGraph` in the `CStore` object any more!
cc #44390
rustbuild: Switch back to using hard links
The `copy` function historically in rustbuild used hard links to speed up the
copy operations that it does. This logic was backed out, however, in #39518 due
to a bug that only showed up on Windows, described in #39504. The cause
described in #39504 happened because Cargo, on a fresh build, would overwrite
the previous artifacts with new hard links that Cargo itself manages.
This behavior in Cargo was fixed in rust-lang/cargo#4390 where it no longer
should overwrite files on fresh builds, opportunistically leaving the filesystem
intact and not touching it.
Hopefully this can help speed up local builds by doing fewer copies all over the
place!
The `copy` function historically in rustbuild used hard links to speed up the
copy operations that it does. This logic was backed out, however, in #39518 due
to a bug that only showed up on Windows, described in #39504. The cause
described in #39504 happened because Cargo, on a fresh build, would overwrite
the previous artifacts with new hard links that Cargo itself manages.
This behavior in Cargo was fixed in rust-lang/cargo#4390 where it no longer
should overwrite files on fresh builds, opportunistically leaving the filesystem
intact and not touching it.
Hopefully this can help speed up local builds by doing fewer copies all over the
place!
