For box expressions, use NZ drop instead of a free block
This falls naturally out of making drop elaboration work with `box`
expressions, which is probably required for sane MIR borrow-checking.
This is a pure refactoring with no intentional functional effects.
r? @nagisa
Improve LLVM/trans scheduling a bit
Currently it's possible that the main thread is waiting on LLVM threads to finish work while its implicit token is going to waste. This PR let's the main thread take over, so one of the running LLVM threads can free its token earlier.
r? @alexcrichton
Put `intrinsics::unreachable` on a possible path to stabilization
Mark it with the `unreachable` feature and put it into the `mem` module.
This is a pretty straight-forward API that can already be simulated in
stable Rust by using `transmute` to create an uninhabited enum that can
be matched.
AddValidation: handle Call terminators into blocks that have multiple incoming edges
The old code was just wrong: It would add validation on paths that don't even come from the call, and it would add multiple validations if multiple calls end return to the same block.
Encode proper module spans in crate metadata.
The spans previously encoded only span the first token after the opening
brace, up to the closing brace of inline `mod` declarations. Thus, when
examining exports from an external crate, the spans don't include the
header of inline `mod` declarations.
r? @eddyb
Provide more explanation for Deref in String docs
While working on a different project I encountered a point of confusion where using `&String` to dereference a `String` into `&str` did not compile. I found the explanation of [String Deref](https://doc.rust-lang.org/std/string/struct.String.html#deref), thought that it matched what I was trying to do, and was confused as to why my program did not compile when the docs stated that it would work with 'any function which takes a `&str`'. At the bottom it is mentioned that this will 'generally' work, unless `String` is needed, but I found this statement confusing based on the previous claim of 'any'. Looking further into the docs I was able to find the function `as_str()` that works instead.
I thought it might be helpful to mention here deref coercion, an instance in which using `&String` does not work, to explain why it does not work, then direct users to a different option that should work in this instance. A user casually skimming the page will likely come to this explanation first, then find `as_str()` later, but be no the wiser as to what potentially went wrong.
r? @steveklabnik
Reexport all SyntaxExtension variants
This was previously done very inconsistently and made matches look weird since some variants had the `SyntaxExtension::` prefix while others didn't.
Detect relative urls in tidy check
This came up in #43631: there can be long relative urls in Markdown comments, that do not start with `http://` or `https://`, so the tidy check will not detect them as urls and complain about the line length. This PR adds detection of relative urls starting with `../`.
E0122: clarify wording
I *assume* the reason these constraints are not hard errors is backwards compatibility. If yes, I think the error explanation (at least the long form) should be clearer about that, which is what this PR does.
If not, the explanation should give some other suitable explanation.
Some assorted region hashing fixes.
This PR contains three changes.
1. It changes what we implement `HashStable` for. Previously, the trait was implemented for things in the local `TyCtxt`. That was OK, since we only invoked hashing with a `TyCtxt<'_, 'tcx, 'tcx>` where there is no difference. With query result hashing this becomes a problem though. So we now implement `HashStable` for things in `'gcx`.
2. The PR makes the regular `HashStable` implementation *not* anonymize late-bound regions anymore. It's a waste of computing resources and it's not clear that it would always be correct to do so.
3. The PR adds an option for stable hashing to treat all regions as erased and uses this new option when computing the `TypeId`. This should help with https://github.com/rust-lang/rust/issues/41875.
I did not add a test case for (3) since that's not possible yet. But it looks like @zackmdavis has something in the pipeline there `:)`.
r? @eddyb
