Disable jump threading of float equality
Jump threading stores values as `u128` (`ScalarInt`) and does its comparisons for equality as integer comparisons.
This works great for integers. Sadly, not everything is an integer.
Floats famously have wonky equality semantcs, with `NaN!=NaN` and `0.0 == -0.0`. This does not match our beautiful integer bitpattern equality and therefore causes things to go horribly wrong.
While jump threading could be extended to support floats by remembering that they're floats in the value state and handling them properly, it's signficantly easier to just disable it for now.
fixes#128243
Delete `SimplifyArmIdentity` and `SimplifyBranchSame` tests
These two passes have already been deleted in #107256. I'm not sure why tidy didn't catch it.
As regression tests, I didn't delete `tests/ui/mir/issue-66851.rs` and `tests/ui/mir/simplify-branch-same.rs`.
r? compiler
[illumos/solaris] set MSG_NOSIGNAL while writing to sockets
Both these platforms have MSG_NOSIGNAL available, and we should set it for socket writes in the event that the SIGPIPE handler has been reset to SIG_DFL (i.e. terminate the process).
I've verified via a quick program at
https://github.com/sunshowers/msg-nosignal-test/ that even when the SIGPIPE handler is reset to SIG_DFL, writes to closed TCP sockets now error out with EPIPE. (Under ordinary circumstances UDP writes won't cause MSG_NOSIGNAL.)
However, I couldn't find any existing tests which verified the MSG_NOSIGNAL behavior.
Remove logic to suggest clone of function output
I can't exactly tell, but I believe that this suggestion is operating off of a heuristic that the lifetime of a function's input is correlated with the lifetime of a function's output in such a way that cloning would fix an error. I don't think that actually manages to hit the bar of "actually provides useful suggestions" most of the time.
Specifically, I've hit false-positives due to this suggestion *twice* when fixing ICEs in the compiler, so I don't think it's worthwhile having this logic around. Neither of the two affected UI tests are actually fixed by the suggestion.
improve error message when `global_asm!` uses `asm!` options
specifically, what was
error: expected one of `)`, `att_syntax`, or `raw`, found `preserves_flags`
--> $DIR/bad-options.rs:45:25
|
LL | global_asm!("", options(preserves_flags));
| ^^^^^^^^^^^^^^^ expected one of `)`, `att_syntax`, or `raw`
is now
error: the `preserves_flags` option cannot be used with `global_asm!`
--> $DIR/bad-options.rs:45:25
|
LL | global_asm!("", options(preserves_flags));
| ^^^^^^^^^^^^^^^ the `preserves_flags` option is not meaningful for global-scoped inline assembly
mirroring the phrasing of the [reference](https://doc.rust-lang.org/reference/inline-assembly.html#options).
This is also a bit of a refactor for a future `naked_asm!` macro (for use in `#[naked]` functions). Currently this sort of error can come up when switching from inline to global asm, or when a user just isn't that experienced with assembly. With `naked_asm!` added to the mix hitting this error is more likely.
from_ref, from_mut: clarify documentation
This was brought up [here](https://github.com/rust-lang/rust/issues/56604#issuecomment-2143193486). The domain of quantification is generally always constrained by the type in the type signature, and I am not sure it's always worth spelling that out explicitly as that makes things exceedingly verbose. But since this was explicitly brought up, let's clarify.
I misread this one. It is only checking if LLVM needs to be rebuilt.
There is code below that handles the case where it is unable to compute
the stamp if the source is missing.
These are required 100% of the time, but they are almost always required
for any command that runs Cargo in the main workspace.
Ideally, initializing these two standard library submodules would be
lazy and only initialized when required (see
https://github.com/rust-lang/rust/pull/82653). However, it would require
updating these in almost every Step (anything that runs `cargo` in the
main workspace).
Jump threading stores values as `u128` (`ScalarInt`) and does its
comparisons for equality as integer comparisons.
This works great for integers. Sadly, not everything is an integer.
Floats famously have wonky equality semantcs, with `NaN!=NaN` and
`0.0 == -0.0`. This does not match our beautiful integer bitpattern
equality and therefore causes things to go horribly wrong.
While jump threading could be extended to support floats by remembering
that they're floats in the value state and handling them properly,
it's signficantly easier to just disable it for now.
Make `missing_fragment_specifier` an error in edition 2024
`missing_fragment_specifier` has been a future compatibility warning since 2017. Uplifting it to an unconditional hard error was attempted in 2020, but eventually reverted due to fallout.
Make it an error only in edition >= 2024, leaving the lint for older editions. This change will make it easier to support more macro syntax that relies on usage of `$`.
Fixes <https://github.com/rust-lang/rust/issues/40107>
---
It is rather late for the edition but since this change is relatively small, it seems worth at least bringing up. This follows a brief [Zulip discussion](https://rust-lang.zulipchat.com/#narrow/stream/268952-edition/topic/.60.20DBD.20-.3E.20hard.20error) (cc `@tmandry).`
Making this an edition-dependent lint has come up before but there was not a strong motivation. I am proposing it at this time because this would simplify the [named macro capture groups](https://github.com/rust-lang/rfcs/pull/3649) RFC, which has had mildly positive response, and makes use of new `$` syntax in the matcher. The proposed syntax currently parses as metavariables without a fragment specifier; this warning is raised, but there are no errors.
It is obviously not known that this specific RFC will eventually be accepted, but forbidding `missing_fragment_specifier` should make it easier to support any new syntax in the future that makes use of `$` in different ways. The syntax conflict is also not impossible to overcome, but making it clear that unnamed metavariables are rejected makes things more straightforward and should allow for better diagnostics.
`@Mark-Simulacrum` suggested making this forbid-by-default instead of an error at https://github.com/rust-lang/rust/issues/40107#issuecomment-761727885, but I don't think this would allow the same level of syntax flexibility.
It is also possible to reconsider making this an unconditional error since four years have elapsed since the previous attempt, but this seems likely to hit the same pitfalls. (Possibly worth a crater run?)
Tracking:
- https://github.com/rust-lang/rust/issues/128143
- merge error codes
- use attribute name that is incompatible in error message
- add test for conditional incompatible attribute
- add `linkage` to the allowlist
`missing_fragment_specifier` has been a future compatibility warning
since 2017. Uplifting it to an unconditional hard error was attempted in
2020, but eventually reverted due to fallout.
Make it an error only in edition >= 2024, leaving the lint for older
editions. This change will make it easier to support more macro syntax
that relies on usage of `$`.
Fixes <https://github.com/rust-lang/rust/issues/40107>
Always set `result` during `finish()` in debug builders
Most functions for format builders set `self.result` after writing strings. This ensures that any further writing fails immediately rather than trying to write again.
A few `.finish()` methods and the `.finish_non_exhaustive` did have this same behavior, so update the remaining `.finish()` methods to make it consistent here.
Both these platforms have MSG_NOSIGNAL available, and we should set it for
socket writes in the event that the SIGPIPE handler has been reset to SIG_DFL
(i.e. terminate the process).
I've verified via a quick program at
https://github.com/sunshowers/msg-nosignal-test/ that even when the SIGPIPE
handler is reset to SIG_DFL, writes to closed sockets now error out with EPIPE.
(Under ordinary circumstances UDP writes won't cause MSG_NOSIGNAL.)
Improve `extern "<abi>" unsafe fn()` error message
These errors were already reported in #87217, and fixed by #87235 but missed the case of an explicit ABI.
This PR does not cover multiple keywords like `extern "C" pub const unsafe fn()`, but I don't know what a good way to cover this would be. It also seems rarer than `extern "C" unsafe` which I saw happen a few times in workshops.
Remove unnecessary range replacements
This PR removes an unnecessary range replacement in `collect_tokens_trailing_token`, and does a couple of other small cleanups.
r? ````@petrochenkov````
rustdoc: change title of search results
the current title is too similar to that of the page for std::result::Result, which is a problem both for
navigating to the Result docs via browser autocomplete, and for being able to tell which tab is which when the width of tabs is small.
