Move computation of allocator shim contents to cg_ssa
In the future this should make it easier to use weak symbols for the allocator shim on platforms that properly support weak symbols. And it would allow reusing the allocator shim code for handling default implementations of the upcoming externally implementable items feature on platforms that don't properly support weak symbols.
In addition to make this possible, the alloc error handler is now handled in a way such that it is possible to avoid using the allocator shim when liballoc is compiled without `no_global_oom_handling` if you use `#[alloc_error_handler]`. Previously this was only possible if you avoided liballoc entirely or compiled it with `no_global_oom_handling`. You still need to avoid libstd and to define the symbol that indicates that avoiding the allocator shim is unstable.
std: improve handling of timed condition variable waits on macOS
Fixesrust-lang/rust#37440 (for good).
This fixes two issues with `Condvar::wait_timeout` on macOS:
Apple's implementation of `pthread_cond_timedwait` internally converts the absolute timeout to a relative one, measured in nanoseconds, but fails to consider overflow when doing so. This results in `wait_timeout` returning much earlier than anticipated when passed a duration that is slightly longer than `u64::MAX` nanoseconds (around 584 years). The existing clamping introduced by rust-lang/rust#42604 to address rust-lang/rust#37440 unfortunately used a maximum duration of 1000 years and thus still runs into the bug when run on older macOS versions (or with `PTHREAD_MUTEX_USE_ULOCK` set to a value other than "1"). See https://github.com/rust-lang/rust/issues/37440#issuecomment-3285958326 for context.
Reducing the maximum duration alone however would not be enough to make the implementation completely correct. As macOS does not support `pthread_condattr_setclock`, the deadline passed to `pthread_cond_timedwait` is measured against the wall-time clock. `std` currently calculates the deadline by retrieving the current time and adding the duration to that, only for macOS to convert the deadline back to a relative duration by [retrieving the current time itself](https://github.com/apple-oss-distributions/libpthread/blob/1ebf56b3a702df53213c2996e5e128a535d2577e/src/pthread_cond.c#L802-L819) (this conversion is performed before the aforementioned problematic one). Thus, if the wall-time clock is adjusted between the `std` lookup and the system lookup, the relative duration could have changed, possibly even to a value larger than $2^{64}\ \textrm{ns}$. Luckily however, macOS supports the non-standard, tongue-twisting `pthread_cond_timedwait_relative_np` function which avoids the wall-clock-time roundtrip by taking a relative timeout. Even apart from that, this function is perfectly suited for `std`'s purposes: it is public (albeit badly-documented) API, [available since macOS 10.4](https://github.com/apple-oss-distributions/libpthread/blob/1ebf56b3a702df53213c2996e5e128a535d2577e/include/pthread/pthread.h#L555-L559) (that's way below our minimum of 10.12) and completely resilient against wall-time changes as all timeouts are [measured against the monotonic clock](https://github.com/apple-oss-distributions/xnu/blob/e3723e1f17661b24996789d8afc084c0c3303b26/bsd/kern/sys_ulock.c#L741) inside the kernel.
Thus, this PR switches `Condvar::wait_timeout` to `pthread_cond_timedwait_relative_np`, making sure to clamp the duration to a maximum of $2^{64} - 1 \ \textrm{ns}$. I've added a miri shim as well, so the only thing missing is a definition of `pthread_cond_timedwait_relative_np` inside `libc`.
Hide vendoring and copyright in GHA group
These two steps are currently the most verbose steps in a dist-linux build, which makes it harder to find more interesting parts. Hide them in a group like most things.
For example, see https://github.com/rust-lang/rust/actions/runs/18462295959/job/52596384752
These two steps are currently the most verbose steps in a dist-linux
build, which makes it harder to find more interesting parts. Hide them
in a group like most things.
Rollup of 7 pull requests
Successful merges:
- rust-lang/rust#144266 (Supress swapping lhs and rhs in equality suggestion in extern macro )
- rust-lang/rust#147471 (Assert that non-extended temporaries and `super let` bindings have scopes)
- rust-lang/rust#147533 (Renumber return local after state transform)
- rust-lang/rust#147566 (rewrite outlives placeholder constraints to outlives static when handling opaque types)
- rust-lang/rust#147613 (Make logging filters work again by moving EnvFilter into its own layer)
- rust-lang/rust#147615 (reduce calls to attr.span() in old doc attr parsing)
- rust-lang/rust#147636 (miri subtree update)
r? `@ghost`
`@rustbot` modify labels: rollup
Generalize configuring LLD as the default linker in bootstrap
Reopen of https://github.com/rust-lang/rust/pull/147157, because apparently bors can't deal with it for some reason.
r? ``@ghost``
Update LLVM to 21.1.3
Fixes https://github.com/rust-lang/rust/issues/146742.
After rust-lang/rust#146124, we need more space to run x86_64-gnu-distcheck if building LLVM from source. According to the building log, the space freed by `free-disk-space-linux.sh` is not entirely available.
```
You are running out of disk space.
The runner will stop working when the machine runs out of disk space.
Free space left: 98 MB
disk usage:
Filesystem Size Used Avail Use% Mounted on
/dev/root 72G 43G 29G 60% /
tmpfs 7.9G 84K 7.9G 1% /dev/shm
tmpfs 3.2G 1.2M 3.2G 1% /run
tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/sda16 881M 60M 760M 8% /boot
/dev/sda15 105M 6.2M 99M 6% /boot/efi
/dev/sdb1 74G 28K 70G 1% /mnt
tmpfs 1.6G 12K 1.6G 1% /run/user/1001
```
Add tidy to the target of ./x check
## Context
Discussion: https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap/topic/tidy.20isn't.20in.20.2E.2Fx.20check/with/544323712
Currently `tidy` (src/tools/tidy) is not included in the list of `./x check`. It means that rust-analyzer doesn't work for codes in the directory if you use `./x check` as the analyzer on your IDE.
## Change
This PR adds src/tools/tidy into the target of `./x check`. It enables rust-analyzer highlight errors/warns on all codes in the directory.
Note that since tidy is implicitly checked by `./x test tidy`, this new check is off by default.
Don't unconditionally build alloc for `no-std` targets
It's possible for targets to only support `core` and not `alloc`. Instead of building alloc unconditionally, pass a list of crates to build into `std_cargo`, and only pass `-p alloc` if the list of crates wasn't already filtered to a subset.
The original use case was to reuse `std_cargo` for a rustc_driver that doesn't emit metadata. But this seems like a reasonable change regardless.
Not all ARMv7-A CPUs have a double-precision FPU. So adjust the CFLAGS
from `+vfpv3` (which assumes 32 double-precision registers) to `+fp`
(which only assumes 16 double-precision registers).
Perform unused assignment and unused variables lints on MIR.
Rebase of https://github.com/rust-lang/rust/pull/101500
Fixes https://github.com/rust-lang/rust/issues/51003.
The first commit moves detection of uninhabited types from the current liveness pass to MIR building.
In order to keep the same level of diagnostics, I had to instrument MIR a little more:
- keep for which original local a guard local is created;
- store in the `VarBindingForm` the list of introducer places and whether this was a shorthand pattern.
I am not very proud of the handling of self-assignments. The proposed scheme is in two parts: first detect probable self-assignments, by pattern matching on MIR, and second treat them specially during dataflow analysis. I welcome ideas.
Please review carefully the changes in tests. There are many small changes to behaviour, and I'm not sure all of them are desirable.
This commit adds src/tools/tidy into `./x check`. It enables rust-analyzer hightlights errors/warns on all codes in src/tools/tidy.
Since tidy is implicitly checked by `./x test tidy`, this new check is off by default.
Currently x.py help (or x.py --help) builds bootstrap binary everytime, but it delays printing help.
This change saves the current top level help text into a file. x.py help prints the file and doesn't touch bootstrap binary.
x.py test bootstrap checks if the file is up to date.
Note that subcommand level helps (e.g., x.py check --help) aren't saved.
bors