Make `Sharded` an enum and specialize it for the single thread case
This changes `Sharded` to use a single shard by an enum, reducing the size of `Sharded` for greater cache efficiency.
Performance improvement with 1 thread and `cfg(parallel_compiler)`:
<table><tr><td rowspan="2">Benchmark</td><td colspan="1"><b>Before</b></th><td colspan="2"><b>After</b></th></tr><tr><td align="right">Time</td><td align="right">Time</td><td align="right">%</th></tr><tr><td>🟣 <b>clap</b>:check</td><td align="right">1.7009s</td><td align="right">1.6748s</td><td align="right">💚 -1.53%</td></tr><tr><td>🟣 <b>hyper</b>:check</td><td align="right">0.2525s</td><td align="right">0.2451s</td><td align="right">💚 -2.90%</td></tr><tr><td>🟣 <b>regex</b>:check</td><td align="right">0.9519s</td><td align="right">0.9353s</td><td align="right">💚 -1.74%</td></tr><tr><td>🟣 <b>syn</b>:check</td><td align="right">1.5504s</td><td align="right">1.5280s</td><td align="right">💚 -1.45%</td></tr><tr><td>🟣 <b>syntex_syntax</b>:check</td><td align="right">5.9536s</td><td align="right">5.8873s</td><td align="right">💚 -1.11%</td></tr><tr><td>Total</td><td align="right">10.4092s</td><td align="right">10.2706s</td><td align="right">💚 -1.33%</td></tr><tr><td>Summary</td><td align="right">1.0000s</td><td align="right">0.9825s</td><td align="right">💚 -1.75%</td></tr></table>
I did see an unexpected 0.23% change for the serial compiler, so this could use a perf run to see if that reproduces.
cc `@SparrowLii`
Ensure that THIR unsafety check is done before stealing it
This ensures that THIR unsafety check is done before stealing it by running it on the typeck root instead of on a closure, which does nothing.
Fixes https://github.com/rust-lang/rust/issues/111520
```
error[E0596]: cannot borrow `*test` as mutable, as it is behind a `&` reference
--> $DIR/suggest-mut-iterator.rs:22:9
|
LL | for test in &tests {
| ------ this iterator yields `&` references
LL | test.add(2);
| ^^^^ `test` is a `&` reference, so the data it refers to cannot be borrowed as mutable
|
help: use a mutable iterator instead
|
LL | for test in &mut tests {
| +++
```
Address #114311.
This option tells LLVM to emit relaxable relocation types
R_X86_64_GOTPCRELX/R_X86_64_REX_GOTPCRELX/R_386_GOT32X in applicable cases. True
matches Clang's CMake default since 2020-08 [1] and latest LLVM default[2].
This also works around a GNU ld<2.41 issue[3] when using
general-dynamic/local-dynamic TLS models in `-Z plt=no` mode with latest LLVM.
[1]: c41a18cf61
[2]: 2aedfdd9b8
[3]: https://sourceware.org/bugzilla/show_bug.cgi?id=24784
ArchiveWrapper: handle LLVM API update
In llvm/llvm-project@f740bcb370 a boolean parameter changed to an enum.
r? ``@nikic``
``@rustbot`` label: +llvm-main
Add support for `ptr::write`s for the `invalid_reference_casting` lint
This PR adds support for `ptr::write` and others for the `invalid_reference_casting` lint.
Detecting instances where instead of using the deref (`*`) operator to assign someone uses `ptr::write`, `ptr::write_unaligned` or `ptr::write_volatile`.
```rust
let data_len = 5u64;
std::ptr::write(
std::mem::transmute::<*const u64, *mut u64>(&data_len),
new_data_len,
);
```
r? ``@est31``
Don't do intra-pass validation on MIR shims
Fixes#114375
In the test that was committed, we end up generating the drop shim for `struct Foo` that looks like:
```
fn std::ptr::drop_in_place(_1: *mut Foo) -> () {
let mut _0: ();
bb0: {
goto -> bb5;
}
bb1: {
return;
}
bb2 (cleanup): {
resume;
}
bb3: {
goto -> bb1;
}
bb4 (cleanup): {
drop(((*_1).0: foo::WrapperWithDrop<()>)) -> [return: bb2, unwind terminate];
}
bb5: {
drop(((*_1).0: foo::WrapperWithDrop<()>)) -> [return: bb3, unwind: bb2];
}
}
```
In `bb4` and `bb5`, we assert that `(*_1).0` has type `WrapperWithDrop<()>`. However, In a user-facing param env, the type is actually `WrapperWithDrop<Tait>`. These types are not equal in a user-facing param-env (and can't be made equal even if we use `DefiningAnchor::Bubble`, since it's a non-local TAIT).
Use the same DISubprogram for each instance of the same inlined function within a caller
# Issue Details:
The call to `panic` within a function like `Option::unwrap` is translated to LLVM as a `tail call` (as it will never return), when multiple calls to the same function like this is inlined LLVM will notice the common `tail call` block (i.e., loading the same panic string + location info and then calling `panic`) and merge them together.
When merging these instructions together, LLVM will also attempt to merge the debug locations as well, but this fails (i.e., debug info is dropped) as Rust emits a new `DISubprogram` at each inline site thus LLVM doesn't recognize that these are actually the same function and so thinks that there isn't a common debug location.
As an example of this when building for x86_64 Windows (note the lack of `.cv_loc` before the call to `panic`, thus it will be attributed to the same line at the `addq` instruction):
```
.cv_loc 0 1 23 0 # src\lib.rs:23:0
addq $40, %rsp
retq
leaq .Lalloc_f570dea0a53168780ce9a91e67646421(%rip), %rcx
leaq .Lalloc_629ace53b7e5b76aaa810d549cc84ea3(%rip), %r8
movl $43, %edx
callq _ZN4core9panicking5panic17h12e60b9063f6dee8E
int3
```
# Fix Details:
Cache the `DISubprogram` emitted for each inlined function instance within a caller so that this can be reused if that instance is encountered again, this also requires caching the `DILexicalBlock` and `DIVariable` objects to avoid creating duplicates.
After this change the above assembly now looks like:
```
.cv_loc 0 1 23 0 # src\lib.rs:23:0
addq $40, %rsp
retq
.cv_inline_site_id 5 within 0 inlined_at 1 0 0
.cv_inline_site_id 6 within 5 inlined_at 1 12 0
.cv_loc 6 2 935 0 # library\core\src\option.rs:935:0
leaq .Lalloc_5f55955de67e57c79064b537689facea(%rip), %rcx
leaq .Lalloc_e741d4de8cb5801e1fd7a6c6795c1559(%rip), %r8
movl $43, %edx
callq _ZN4core9panicking5panic17hde1558f32d5b1c04E
int3
```
Add disclaimer on size assertion macro
Sometimes people are inspired by rustc to add size assertions to their code and copy the macro. This is bad because it causes hard build errors. rustc happens to be special where it makes this okay.
For example, see #115028 (not sure whether they were directly inspired by this function), but I think I've also seen other cases.
Warn on elided lifetimes in associated constants (`ELIDED_LIFETIMES_IN_ASSOCIATED_CONSTANT`)
Elided lifetimes in associated constants (in impls) erroneously resolve to fresh lifetime parameters on the impl since #97313. This is not correct behavior (see #38831).
I originally opened #114716 to fix this, but given the time that has passed, the crater results seem pretty bad: https://github.com/rust-lang/rust/pull/114716#issuecomment-1682091952
This PR alternatively implements a lint against this behavior, and I'm hoping to bump this to deny in a few versions.
Redefine the pluralize macro's arm
Redefine the unintuitive pluralize macro's arm because of the negation. The initial code starts with check if count is not 1, which is confusing and unintuitive.
The arm shoud start with checking,
- if "count" `is 1` then, append `""` (empty string) - indicate as singular
- Then check if "count" `is not 1` (more than 1), append `"s"` - indicate as plural
Before:
```rs
// This arm is abit confusing since it start with checking, if "count" is more than 1, append "s".
($x:expr) => {
if $x != 1 { "s" } else { "" }
};
```
After:
```rs
// Pluralize based on count (e.g., apples)
($x:expr) => {
if $x == 1 { "" } else { "s" }
};
```
Coverage statements in MIR are heavily tied to internal details of the coverage
implementation that are likely to change, and are unlikely to be useful to
third-party tools for the foreseeable future.
Sometimes people are inspired by rustc to add size assertions to their
code and copy the macro. This is bad because it causes hard build
errors. rustc happens to be special where it makes this okay.
