Rollup of 10 pull requests
Successful merges:
- #67450 (Allow for setting a ThinLTO import limit during bootstrap)
- #67595 (Suggest adding a lifetime constraint for opaque type)
- #67636 (allow rustfmt key in [build] section)
- #67736 (Less-than is asymmetric, not antisymmetric)
- #67762 (Add missing links for insecure_time)
- #67783 (Warn for bindings named same as variants when matching against a borrow)
- #67796 (Ensure that we process projections during MIR inlining)
- #67807 (Use drop instead of the toilet closure `|_| ()`)
- #67816 (Clean up err codes)
- #67825 (Minor: change take() docs grammar to match other docs)
Failed merges:
r? @ghost
Ensure that we process projections during MIR inlining
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.
allow rustfmt key in [build] section
Permit using `rustfmt` in `config.toml`. It will allow to not download `rustfmt` binary, which is not possible for at least some tiers-3 platforms.
Fixes: #67624
r? @Mark-Simulacrum
Suggest adding a lifetime constraint for opaque type
Fixes#67577, where code like this:
```
struct List {
data: Vec<String>,
}
impl List {
fn started_with<'a>(&'a self, prefix: &'a str) -> impl Iterator<Item=&'a str> {
self.data.iter().filter(|s| s.starts_with(prefix)).map(|s| s.as_ref())
}
}
```
will show this error:
```
Compiling playground v0.0.1 (/playground)
error[E0597]: `prefix` does not live long enough
--> src/lib.rs:6:47
|
5 | fn started_with<'a>(&'a self, prefix: &'a str) -> impl Iterator<Item=&'a str> {
| -- lifetime `'a` defined here --------------------------- opaque type requires that `prefix` is borrowed for `'a`
...
```
but without suggesting the lovely `help: you can add a constraint..`.
r? @estebank
Allow for setting a ThinLTO import limit during bootstrap
The benchmarks in https://github.com/rust-lang/rust/pull/66625 have shown that a lower ThinLTO import limit can be a net win for bootstrap times. This PR:
- exposes the setting to `config.toml`,
- defaults to a lower limit if `incremental = true` in `config.toml`, and
- sets a lower limit for `x86_64-gnu-llvm-7` CI image in order to make the jobs complete more quickly (which remains to be tested).
This setting will affect how the compiler and it's tools are compiled. It will not affect the settings the compiler uses when compiling user code.
r? @pietroalbini
cc @rust-lang/infra
A bit speculative at this stage but profiling shows that type folding
takes up a substantial amount of time during normalization which may
indicate that many types may be folded despite there being nothing to
normalize
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
