Adjust `transmute{,_copy}` to be clearer about which of `T` and `U` is input vs output
This is essentially a documentation-only change (although it does touch code in an irrelevant way).
The canonical form of a usub.with.overflow check in LLVM are
separate sub + icmp instructions, rather than a usub.with.overflow
intrinsic. Using usub.with.overflow will generally result in worse
optimization potential.
The backend will attempt to form usub.with.overflow when it comes
to actual instruction selection. This is not fully reliable, but
I believe this is a better tradeoff than using the intrinsic in
IR.
Fixes#103285.
Deny hashing ty/re/ct inference variables
cc `@cjgillot` and https://github.com/rust-lang/rust/pull/102695#issuecomment-1275706528
r? `@lcnr`
best reviewed one commit at a time, mostly because the second commit that fixes `ClosureOutlivesRequirement` is mostly noise because of losing its `<'tcx>` lifetime parameter.
Do anonymous lifetimes remapping correctly for nested rpits
Closes#103141
r? `@cjgillot` `@nikomatsakis`
This fixes a stable to stable regression that in my opinion is `P-critical` so, we probably want to backport it all the way up to stable.
Use already checked RHS ty for LHS deref suggestions
There's no reason to do the `check_lhs_assignable` and RHS `check_expr_with_hint` in that order, so invert them and use the typeck results to avoid exponential blowup on error.
Fixes#103219
Let expressions on RHS shouldn't be terminating scopes
Fixes#100276.
Before this PR, we were unconditionally marking the RHS of short-circuiting binary expressions as a terminating scope.
In the case of a let chain where the `let` expression was on the RHS, this meant that temporaries within the `let` expr would only live until the end of the expression. Since this only affected the RHS, this led to surprising behavior ([example](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=d1b0a5d1f01882f9c89c2194a75eb19f)).
After this PR, we only mark the RHS as a terminating scope if it is not a `let` expression.
Standardize "use parentheses to call" suggestions between typeck and trait selection
1. Suggest calling constructors, since they're basically `FnDef`s but they have a different def kind and hir representation, so we were leaving them out.
2. Standardize the call suggestions between trait fulfillment errors and type mismatch. In the type mismatch suggestion, we suggest `/* Ty */` as the placeholder for an arg, and not the parameter's name, which is less helpful.
3. Use `predicate_must_hold_modulo_regions` instead of matching on `EvaluationResult` -- this might cause some suggestions to be filtered out, but we really shouldn't be suggesting a call if it "may" hold, only when it "must" hold.
4. Borrow some logic from `extract_callable_info` to generalize this suggestion to fn pointers, type parameters, and opaque types.
Fixes#102852
Handle core dumps output in QEMU user mode
In addition to the whole-system emulation/virtualization, QEMU also supports user-mode emulation, where the emulation happens as a normal process inside the parent system. This allows running most tests by simply spawning remote-test-server inside user-mode emulation.
Unfortunately, QEMU always writes its own message in addition to the system one when a core dump happens, which breaks a few tests which match on the exact output of the system.
This PR changes those tests to strip the (possible) QEMU output before checking if the output is expected.
