Add Iterator::try_find
I found a need for this fn, and created this PR.
Tracking issue: #63178
I did a fair amount of thinking about the function name, and settled on the current one.
I don't see other anything else that's non-trivial here, but I'm open for debate. I just want this functionality to be there.
It couples with the `collect` trick for collecting `Result<Vec<T>, E>` from `Iterator<Item = Result<T, E>>`.
UPD:
I've already looked at `fallible_iterator` crate, but I don't think it supports my use case.
The main problem is that I can't construct a failable iterator. I have a regular iterator, and I just need to apply a predicate that can fail via `find` method.
UPD: `fallible_iterator` would work, but it's not elegant cause I'd have to make a failable iterator by mapping iterator with `Result::Ok` first.
Using a pure spin lock for a critical section in a preemptable thread
is always wrong, however short the critical section may be. The thread
might be preempted, which will cause all other threads to hammer
busily at the core for the whole quant. Moreover, if threads have
different priorities, this might lead to a priority inversion problem
and a deadlock. More generally, a spinlock is not more efficient than
a well-written mutex, which typically does several spin iterations at
the start anyway.
The advise about UP vs SMP is also irrelevant in the context of
preemptive threads.
Fixes#67710
Previously, we were not calling `super_place`, which resulted in us
failing to update any local references that occur in
ProjectionElem::Index. This caused the post-inlining MIR to contain a
reference to a local ID from the inlined callee, leading to an ICE
due to a type mismatch.
Previously, we relied fully on Cargo to detect that the compiler had changed and
it needed to rebuild the standard library (or later "components"). This used to
not quite be the case prior to moving to LLVM be a separate cargo invocation;
subsequent compiles would recompile std and friends if LLVM had changed
(#67077 is the PR that changes things here).
This PR moves us to clearing out libstd when it is being compiled if the rustc
we're using has changed. We fairly harshly limit the cases in which we do this
(e.g., ignoring dry run mode, and so forth, as well as rustdoc invocations).
This is primarily because when we're not using the compiler directly, so
clearing out in other cases is likely to lead to bugs, particularly as our
deletion scheme is pretty blunt today (basically removing more than is needed,
i.e., not just the rustc artifacts).
In practice, this targeted fix does fix the known bug, though it may not fully
resolve the problem here. It's also not clear that there is a full fix hiding
here that doesn't involve a more major change (like -Zbinary-dep-depinfo was).
As a drive-by fix, don't delete the compiler before calling Build::copy, as that
also deletes the compiler.
Lint overflowing integer casts in const prop
This extends the invalid cases we catch in const prop to include
overflowing integer casts using the same machinery as the overflowing
binary and unary operation logic.
r? @oli-obk
The test checks that we reuse the CGU of a crate when the implementation
details of an `extern crate` have changed.
Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com>
Revert parts of #66405.
Because PR #66405 caused major performance regressions in some cases.
That PR had five commits, two of which affected performance, and three
of which were refactorings. This change undoes the performance-affecting
changes, while keeping the refactorings in place.
Fixes#67454.
r? @nikomatsakis
Because it caused major performance regressions in some cases.
That PR had five commits, two of which affected performance, and three
of which were refactorings. This change undoes the performance-affecting
changes, while keeping the refactorings in place.
Fixes#67454.
Use function attribute "frame-pointer" instead of "no-frame-pointer-elim"
LLVM 8 ([D56351](http://reviews.llvm.org/D56351)) introduced "frame-pointer". In LLVM 10 (D71863),
"no-frame-pointer-elim"/"no-frame-pointer-elim-non-leaf" will be
ignored.
-----
In the LLVM monorepo, run `git show origin/release/8.x:llvm/lib/CodeGen/TargetOptionsImpl.cpp` to see that `"frame-pointer"` is available since LLVM 8.
parser: reduce diversity in error handling mechanisms
Instead of having e.g. `span_err`, `fatal`, etc., we prefer to move towards uniformly using `struct_span_err` thus making it harder to emit fatal and/or unstructured diagnostics.
This PR also de-fatalizes some diagnostics.
r? @estebank
Extract `rustc_ast_lowering` crate from `rustc`
Working towards https://github.com/rust-lang/rust/issues/65031.
This PR moves `src/librustc/hir/lowering{/, .rs}` to its own crate (`librustc_ast_lowering`) which is very self-contained (only `fn lower_crate` and `trait Resolver` are exposed).
r? @Mark-Simulacrum
