Make replacement suggestion `_` in type verbose
```
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/in-signature.rs:6:21
|
LL | fn arr_fn() -> [u8; _] {
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn arr_fn() -> [u8; _] {
LL + fn arr_fn() -> [u8; 3] {
|
```
debuginfo: add an unstable flag to write split DWARF to an explicit directory
Bazel requires knowledge of outputs from actions at analysis time, including file or directory name. In order to work around the lack of predictable output name for dwo files, we group the dwo files in a subdirectory of --out-dir as a post-processing step before returning control to bazel. Unfortunately some debugging workflows rely on directly opening the dwo file rather than loading the merged dwp file, and our trick of moving the files breaks those users. We can't just hardlink the file or copy it, because with remote build execution we wouldn't end up with the un-moved file copied back to the developer's workstation. As a fix, we add this unstable flag that causes dwo files to be written to a build-system-controllable location, which then lets bazel hoover up the dwo files, but the objects also have the correct path for the dwo files.
r? `@davidtwco`
Rollup of 5 pull requests
Successful merges:
- rust-lang/rust#146653 (improve diagnostics for empty attributes)
- rust-lang/rust#146987 (impl Ord for params and use unstable sort)
- rust-lang/rust#147101 (Use `Iterator::eq` and (dogfood) `eq_by` in compiler and library )
- rust-lang/rust#147123 (Fix removed version numbers of `doc_auto_cfg` and `doc_cfg_hide`)
- rust-lang/rust#147149 (add joboet to library review rotation)
r? `@ghost`
`@rustbot` modify labels: rollup
impl Ord for params and use unstable sort
AFAICT we are only sorting to find duplicates, so unstable sort should work fine, and maybe is a tiny bit faster?
remove explicit deref of AbiAlign for most methods
Much of the compiler calls functions on Align projected from AbiAlign. AbiAlign impls Deref to its inner Align, so we can simplify these away. Also, it will minimize disruption when AbiAlign is removed.
For now, preserve usages that might resolve to PartialOrd or PartialEq, as those have odd inference.
Skip stack overflow handler for panic=immediate-abort
std installs guard pages and a signal handler to ensure that stackoverflows 1) terminate abruptly and 2) print an nice message. Even for panic=immediate-abort, 1) is desirable, we don't want silent data corruption there. But 2) is completely unnecessary, as users deliberately *don't* want nice messages, they want minimum binary size.
Therefore, skip the entire guard signal handler setup, which saves a lot of bytes.
I tested this with a hello world binary using fat LTO, build-std, panic=immediate-abort, opt-level=s, strip=debuginfo.
`size` reports significant savings:
```
text data bss dec hex filename
15252 1032 104 16388 4004 tiny-before
6881 964 48 7893 1ed5 tiny-after2
```
`nm -U` goes from 71 to 56, getting rid of a bunch of stack overflow related symbols. The disk size goes from `31k` to `24k`.
The impact on the error message is minimal, as the message was already
missing.
before:
```
fish: Job 1, './tiny-so-before' terminated by signal SIGABRT (Abort)
```
after:
```
fish: Job 1, './tiny-so-after' terminated by signal SIGSEGV (Address boundary error)
```
I didn't test the Windows part, but it likely also has savings.
Much of the compiler calls functions on Align projected from AbiAlign.
AbiAlign impls Deref to its inner Align, so we can simplify these away.
Also, it will minimize disruption when AbiAlign is removed.
For now, preserve usages that might resolve to PartialOrd or PartialEq,
as those have odd inference.
Remove most `#[track_caller]` from allocating Vec methods
They cause significant binary size overhead while contributing little value.
closesrust-lang/rust#146963, see that issue for more details.
Make it possible to `x install` Cranelift and LLVM bitcode linker
It was not possible to install these before, as they were not in the install step description list.
Fixes: https://github.com/rust-lang/rust/issues/140331
r? `@jieyouxu`
JumpThreading: Avoid computing dominators to identify loop headers.
JumpThreading tries to avoid threading through loop headers to avoid creating irreducible CFGs.
However, computing dominators is expensive, and accounts up to 20 % of the runtime of the JumpThreading pass for some cases like serde.
This PR proposes to approximate according to the post-order traversal order. We define a "maybe" loop header as a block which is visited after its predecessor in post-order.
