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`.
Annotate the allocator crates (allocator_system, allocator_jemalloc) by
the type of allocator they are. If one is requested as an exe allocator,
detect its type by the flags.
This has the effect that using this (de jure wrong) configuration in the
target spec works instead of producing a really unhelpful and arcane
linker error:
"exe-allocation-crate": "alloc_system"
Fixes#43524.
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.
