TB: Redefine trigger condition for protectors
The Coq formalization revealed that as currently implemented, read accesses did not always commute.
Indeed starting from a lazily initialized `Active` protected tag, applying a foreign read then a child read produces `Frozen`, but child read then foreign read triggers UB (because the child read initializes _before_ the `Active -> Frozen`).
This reformulation of when protectors trigger fixes that issue:
- instead of `Active + foreign read -> Frozen` and `Active -> Frozen` when protected is UB
- we do `Active + foreign read -> if protected { Disabled } else { Frozen }`
There is already precedent for transitions being dependent on the presence of a protector (`Reserved + foreign read -> if protected { Frozen } else { Reserved }`), and this has the nice side-effect of simplifying the protector trigger condition to just an equality check against `Disabled` since now there is protector UB iff a protected tag becomes `Disabled`.
In order not to introduce an extra `if`, it was decided that `Disabled -> Disabled` would be UB when protected, which was not the case previously. This is merely a theoretical for now because a protected `Disabled` is unreachable in the first place.
The extra test is not directly related to this modification, but also checks things related to protectors and lazy initialization.
Optimize `AtomicBool` for target that don't support byte-sized atomics
`AtomicBool` is defined to have the same layout as `bool`, which means that we guarantee that it has a size of 1 byte. However on certain architectures such as RISC-V, LLVM will emulate byte atomics using a masked CAS loop on an aligned word.
We can take advantage of the fact that `bool` only ever has a value of 0 or 1 to replace `swap` operations with `and`/`or` operations that LLVM can lower to word-sized atomic `and`/`or` operations. This takes advantage of the fact that the incoming value to a `swap` or `compare_exchange` for `AtomicBool` is often a compile-time constant.
### Example
```rust
pub fn swap_true(atomic: &AtomicBool) -> bool {
atomic.swap(true, Ordering::Relaxed)
}
```
### Old
```asm
andi a1, a0, -4
slli a0, a0, 3
li a2, 255
sllw a2, a2, a0
li a3, 1
sllw a3, a3, a0
slli a3, a3, 32
srli a3, a3, 32
.LBB1_1:
lr.w a4, (a1)
mv a5, a3
xor a5, a5, a4
and a5, a5, a2
xor a5, a5, a4
sc.w a5, a5, (a1)
bnez a5, .LBB1_1
srlw a0, a4, a0
andi a0, a0, 255
snez a0, a0
ret
```
### New
```asm
andi a1, a0, -4
slli a0, a0, 3
li a2, 1
sllw a2, a2, a0
amoor.w a1, a2, (a1)
srlw a0, a1, a0
andi a0, a0, 255
snez a0, a0
ret
```
Replace in-tree `rustc_apfloat` with the new version of the crate
Replace the in-tree version of `rustc_apfloat` with the new version of the crate which has been correctly licensed. The new crate incorporates upstream changes from LLVM since the original port was done including many correctness fixes and has been extensively fuzz tested to validate correctness.
Fixes#100233Fixes#102403Fixes#113407Fixes#113409Fixes#55993Fixes#93224Closes#93225Closes#109573
compiletest: remove ci-specific remap-path-prefix
Now that we have fixed the underlying cause of long type name inconsistencies in #113893, we can remove the remap-path-prefix logic from CI
resolves#113424
Remove -Z diagnostic-width
This removes the `-Z diagnostic-width` option since it is ignored and does nothing. `-Z diagnostic-width` was stabilized as `--diagnostic-width` in #95635. It is not entirely clear why the `-Z` flag was kept, but in part its final use was removed in #102216, but the `-Z` flag itself was not removed.
Define CMAKE_SYSTEM_NAME on a cross build targeting DragonFly.
Without `CMAKE_SYSTEM_NAME` set to the target a cross compile will generally fail. Related to #109170.
Squelch a noisy rustc_expand unittest
The test `rustc_parse::tests::bad_path_expr_1` prints an error message to stderr, circumventing libtest's stderr intercept. This causes noise when running tests, in particular they show up 16 times on the GitHub Actions summary page. The solution here is to not use an error emitter that prints to stderr, and instead check that the correct error is generated.
Fix missing attribute merge on glob foreign re-exports
Fixes https://github.com/rust-lang/rust/issues/113982.
The attributes were not merged with the import's in case of glob re-export of foreign items.
r? `@notriddle`
lint/ctypes: fix `()` return type checks
Fixes#113436.
`()` is normally FFI-unsafe, but is FFI-safe when used as a return type. It is also desirable that a transparent newtype for `()` is FFI-safe when used as a return type.
In order to support this, when a type was deemed FFI-unsafe, because of a `()` type, and was used in return type - then the type was considered FFI-safe. However, this was the wrong approach - it didn't check that the `()` was part of a transparent newtype! The consequence of this is that the presence of a `()` type in a more complex return type would make it the entire type be considered safe (as long as the `()` type was the first that the lint found) - which is obviously incorrect.
Instead, this logic is removed, and after [consultation with t-lang](https://github.com/rust-lang/rust/issues/113436#issuecomment-1640756721), I've fixed the bugs and inconsistencies and made `()` FFI-safe within types.
I also refactor a function, but that's not too exciting.
interpret: make read/write methods generic
Instead of always having to call `into()` to convert things to `PlaceTy`/`OpTy`, make the relevant methods generic. This also means that when we read from an `MPlaceTy`, we avoid creating an intermediate `PlaceTy`.
This makes it feasible to remove the `Copy` from `MPlaceTy`. All the other `*Ty` interpreter types already had their `Copy` removed a while ago so this is only consistent. (And in fact we had one function that accidentally took `MPlaceTy` instead of `&MPlaceTy`.)
Split some functions with many arguments into builder pattern functions
r? `@estebank`
This doesn't resolve all of the ones in rustc, mostly because I need to do other cleanups in order to be able to use some builder derives from crates.io
Works around https://github.com/rust-lang/rust/issues/90672 by making `x test rustfmt --bless` format itself instead of testing that it is formatted
Make std tests pass on newer Android
Newer versions of Android forbid the creation of hardlinks as well as Unix domain sockets in the /data filesystem via SELinux rules, which causes several tests depending on this behavior to fail. So let's skip these tests on Android if we see an EACCES from one of these syscalls. To achieve this, introduce a macro with the horrible name of or_panic_or_skip_on_android_eacces (better suggestions welcome) which skips (returns from) the test if an EACCES return value is seen on Android.
add tidy check that forbids issue-XXXX and ice-XXXX test filenames
Helps with #113345 by preventing any future tests with non-descriptive names from being added.
This PR only checks modified ui test files because there are far too many existing problematic tests to be fixed at once:
3063/15424 (~19.86%) `*.rs` ui test files match `^issue[-_ ]?\d+$`.
Another 1349 files, totaling ~28.60% of all ui test files, contain that pattern in addition to some other text, where they should probably omit it in favor of a comment.
note: between the creation of this PR and 2023-07-25 (14 days), 10 more tests were added that failed this check.
r? `@workingjubilee`
new unstable option: -Zwrite-long-types-to-disk
This option guards the logic of writing long type names in files and instead using short forms in error messages in rustc_middle/ty/error behind a flag. The main motivation for this change is to disable this behaviour when running ui tests.
This logic can be triggered by running tests in a directory that has a long enough path, e.g. /my/very-long-path/where/rust-codebase/exists/
This means ui tests can fail depending on how long the path to their file is.
Some ui tests actually rely on this behaviour for their assertions, so for those we enable the flag manually.
