Replace generic thread parker with explicit no-op parker
With #98391 merged, all platforms supporting threads now have their own parking implementations. Therefore, the generic implementation can be removed. On the remaining platforms (really just WASM without atomics), parking is not supported, so calls to `thread::park` now return instantly, which is [allowed by their API](https://doc.rust-lang.org/nightly/std/thread/fn.park.html). This is a change in behaviour, as spurious wakeups do not currently occur since all platforms guard against them. It is invalid to depend on this, but I'm still going to tag this as libs-api for confirmation.
````@rustbot```` label +T-libs +T-libs-api +A-atomic
r? rust-lang/libs
Add cross-language LLVM CFI support to the Rust compiler
This PR adds cross-language LLVM Control Flow Integrity (CFI) support to the Rust compiler by adding the `-Zsanitizer-cfi-normalize-integers` option to be used with Clang `-fsanitize-cfi-icall-normalize-integers` for normalizing integer types (see https://reviews.llvm.org/D139395).
It provides forward-edge control flow protection for C or C++ and Rust -compiled code "mixed binaries" (i.e., for when C or C++ and Rust -compiled code share the same virtual address space). For more information about LLVM CFI and cross-language LLVM CFI support for the Rust compiler, see design document in the tracking issue #89653.
Cross-language LLVM CFI can be enabled with -Zsanitizer=cfi and -Zsanitizer-cfi-normalize-integers, and requires proper (i.e., non-rustc) LTO (i.e., -Clinker-plugin-lto).
Thank you again, ``@bjorn3,`` ``@nikic,`` ``@samitolvanen,`` and the Rust community for all the help!
Implement tuple<->array convertions via `From`
This PR adds the following impls that convert between homogeneous tuples and arrays of the corresponding lengths:
```rust
impl<T> From<[T; 1]> for (T,) { ... }
impl<T> From<[T; 2]> for (T, T) { ... }
/* ... */
impl<T> From<[T; 12]> for (T, T, T, T, T, T, T, T, T, T, T, T) { ... }
impl<T> From<(T,)> for [T; 1] { ... }
impl<T> From<(T, T)> for [T; 2] { ... }
/* ... */
impl<T> From<(T, T, T, T, T, T, T, T, T, T, T, T)> for [T; 12] { ... }
```
IMO these are quite uncontroversial but note that they are, just like any other trait impls, insta-stable.
When we're adding a method to a type DIE, we only want a DW_AT_declaration
there, because LLVM LTO can't unify type definitions when a child DIE is a
full subprogram definition. Now the subprogram definition gets added at the
CU level with a specification link back to the abstract declaration.
This commit adds cross-language LLVM Control Flow Integrity (CFI)
support to the Rust compiler by adding the
`-Zsanitizer-cfi-normalize-integers` option to be used with Clang
`-fsanitize-cfi-icall-normalize-integers` for normalizing integer types
(see https://reviews.llvm.org/D139395).
It provides forward-edge control flow protection for C or C++ and Rust
-compiled code "mixed binaries" (i.e., for when C or C++ and Rust
-compiled code share the same virtual address space). For more
information about LLVM CFI and cross-language LLVM CFI support for the
Rust compiler, see design document in the tracking issue #89653.
Cross-language LLVM CFI can be enabled with -Zsanitizer=cfi and
-Zsanitizer-cfi-normalize-integers, and requires proper (i.e.,
non-rustc) LTO (i.e., -Clinker-plugin-lto).
Fixes#10609: Adds lint to detect construction of unit struct using `default`
Using `default` to construct a unit struct increases code complexity and adds a function call. This can be avoided by simply removing the call to `default` and simply construct by name.
changelog: [`default_constructed_unit_structs`]: detects construction of unit structs using `default`
fixes#10609
Rollup of 11 pull requests
Successful merges:
- #107978 (Correctly convert an NT path to a Win32 path in `read_link`)
- #110436 (Support loading version information from xz tarballs)
- #110791 (Implement negative bounds for internal testing purposes)
- #110874 (Adjust obligation cause code for `find_and_report_unsatisfied_index_impl`)
- #110908 (resolve: One more attempt to simplify `module_children`)
- #110943 (interpret: fail more gracefully on uninit unsized locals)
- #111062 (Don't bail out early when checking invalid `repr` attr)
- #111069 (remove pointless `FIXME` in `bootstrap::download`)
- #111086 (Remove `MemEncoder`)
- #111097 (Avoid ICEing miri on layout query cycles)
- #111112 (Add some triagebot notifications for nnethercote.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Avoid ICEing miri on layout query cycles
Miri has special logic for catching panics during interpretation. Raising a fatal error in rustc uses unwinding to abort compilation. Thus miri ends up catching that fatal error and thinks it saw an ICE. While we should probably change that to ignore `Fatal` payloads, I think it's also neat to continue compilation after a layout query cycle 😆
Query cycles now (in addition to reporting an error just like before), return `Err(Cycle)` instead of raising a fatal error. This allows the interpreter to wind down via the regular error paths.
r? `@RalfJung` for a first round, feel free to reroll for the compiler team once the miri side looks good
remove pointless `FIXME` in `bootstrap::download`
The suggestion given by `FIXME` to use `CompilerMetadata` for `download_toolchain` in `bootstrap::download` can result in more confusion. This is because `stamp_key` is not always a date; it can also be a commit hash. Additionally, unlike in `download_beta_toolchain`, in the `download_ci_rustc` function, `version` and `commit` values are calculated separately.
Don't bail out early when checking invalid `repr` attr
Fixes#111051
An invalid repr delays a bug. If there are other invalid attributes on the item, we emit a warning and exit without re-checking the repr here, so no error is emitted and the delayed bug ICEs
Implement negative bounds for internal testing purposes
Implements partial support the `!` negative polarity on trait bounds. This is incomplete, but should allow us to at least be able to play with the feature.
Not even gonna consider them as a public-facing feature, but I'm implementing them because would've been nice to have in UI tests, for example in #110671.
Support loading version information from xz tarballs
This is intended to allow us to move recompression from xz (produced in CI) to gz after an initial manifest run, which produces a list of actually required artifacts. The rest are then deleted, which means that we can avoid recompressing them, saving a bunch of time.
This is essentially untested and more might be needed, will run a patched promote-release against try artifacts from this PR. If we do go ahead with this we'll either need to backport this patch to beta/stable, wait for it to propagate, or temporarily recompress to gzip but not xz tarballs (or similar).
r? `@pietroalbini`
Correctly convert an NT path to a Win32 path in `read_link`
This can be done by simply changing the `\??\` prefix to `\\?\`.
Currently it strips off the prefix which could lead to the wrong path being returned (e.g. if it's not a drive path or if the path contains trailing spaces, etc).
r? libs
Some data-independent timing vector instructions may have subtle data-dependent
timing due to MXCSR configuration; dependent on (potentially secret) data
instruction retirement may be delayed by one cycle.
ci: upgrade and refactor crosstool-ng builders
The first commit upgrades our builders from crosstool-ng 1.24.0 to 1.25.0. There are otherwise no changes intended to the toolchains we're using, but there are some minor version upgrades as a result, especially GCC 8.3.0 to 8.5.0. The newer crosstool-ng will position us well to make toolchain upgrades in the future though, as we were maxed out before and it now goes up to GCC 11.
The second commit refactors our config management to only commit a "mini-defconfig" for each target, produced by `ct-ng savedefconfig`. This makes it much clearer which settings we're actually changing, and also makes it easier to ensure consistency for things like mirror management.
This can be done by simply changing the `\??\` prefix to `\\?\` and then attempting to convert to a user path.
Currently it simply strips off the prefix which could lead to the wrong path being returned (e.g. if it's not a drive path or if the path contains trailing spaces, etc).
Optimize builder sizes
The infra-team is continuously monitoring the efficiency of the CI system in an effort to improve overall build times and resource usage. Some builders have used much less than their allocated resources, so we are testing smaller builder sizes for them.
r? `@pietroalbini`
Restrict `From<S>` for `{D,Subd}iagnosticMessage`.
Currently a `{D,Subd}iagnosticMessage` can be created from any type that impls `Into<String>`. That includes `&str`, `String`, and `Cow<'static, str>`, which are reasonable. It also includes `&String`, which is pretty weird, and results in many places making unnecessary allocations for patterns like this:
```
self.fatal(&format!(...))
```
This creates a string with `format!`, takes a reference, passes the reference to `fatal`, which does an `into()`, which clones the reference, doing a second allocation. Two allocations for a single string, bleh.
This commit changes the `From` impls so that you can only create a `{D,Subd}iagnosticMessage` from `&str`, `String`, or `Cow<'static, str>`. This requires changing all the places that currently create one from a `&String`. Most of these are of the `&format!(...)` form described above; each one removes an unnecessary static `&`, plus an allocation when executed. There are also a few places where the existing use of `&String` was more reasonable; these now just use `clone()` at the call site.
As well as making the code nicer and more efficient, this is a step towards possibly using `Cow<'static, str>` in
`{D,Subd}iagnosticMessage::{Str,Eager}`. That would require changing the `From<&'a str>` impls to `From<&'static str>`, which is doable, but I'm not yet sure if it's worthwhile.
r? `@davidtwco`
