Support defining C compatible variadic functions
## Summary
Add support for defining C compatible variadic functions in unsafe rust with
`extern "C"` according to [RFC 2137].
## Details
### Parsing
When parsing a user defined function that is `unsafe` and `extern "C"` allow
variadic signatures and inject a "spoofed" `VaList` in the new functions
signature. This allows the user to interact with the variadic arguments via a
`VaList` instead of manually using `va_start` and `va_end` (See [RFC 2137] for
details).
### Codegen
When running codegen for a variadic function, remove the "spoofed" `VaList`
from the function signature and inject `va_start` when the arg local
references are created for the function and `va_end` on return.
## TODO
- [x] Get feedback on injecting `va_start/va_end` in MIR vs codegen
- [x] Properly inject `va_end` - It seems like it should be possible to inject
`va_end` on the `TerminatorKind::Return`. I just need to figure out how
to get the `LocalRef` here.
- [x] Properly call Rust defined C variadic functions in Rust - The spoofed
`VaList` causes problems here.
Related to: #44930
r? @ghost
[RFC 2137]: https://github.com/rust-lang/rfcs/blob/master/text/2137-variadic.md
Function signatures with the `variadic` member set are actually
C-variadic functions. Make this a little more explicit by renaming the
`variadic` boolean value, `c_variadic`.
- Move closures defined in codegen_terminator into a separate helper
structure and implementation.
- Create helper functions for each of the complex match arms on the
terminators kind in codegen_terminator.
Normalize the type Self resolves to in an impl
This is required at the very least in order to evaluate associated
constants for arrays.
Fixes#57796Fixes#58212.
r? @oli-obk
cc @hellow554
update scoped_tls to 1.0
scoped_tls has been updated to version 1.0
This PR will hopefully merge flawlessly :)
This fixes, among others, https://github.com/alexcrichton/scoped-tls/issues/9
Note, that the nightly feature has been removed in 64bd7b84a1
std: docs: Disable running several Stdio doctests
* A number of `Stdio` related doc examples include running the "rev"
command to illustrate piping commands. The majority of these tests are
marked as `no_run` except for two tests which were not
* Not running these tests is unlikely to cause any negative impact, and
doing so also allows the test suite to pass in environments where the
"rev" command is unavailable
Deny `async fn` in 2015 edition
This commit prevents code using `async fn` from being compiled in Rust 2015 edition.
Compiling code of the form:
```rust
async fn foo() {}
```
Will now result in the error:
```
error[E0670]: `async fn` is not permitted in the 2015 edition
--> async.rs:1:1
|
1 | async fn foo() {}
| ^^^^^
error: aborting due to error
For more information about an error, try `rustc --explain E0670`.
```
This resolves#58652 and also resolves#53714.
r? @varkor
rustdoc: move collapse and unindent docs passes earlier
Moves these passes as early as possible so later passes will see the same markdown that is passed to the test collector.
Fixes#58473, and a similar issue with the private-doc-tests lint.
r? @QuietMisdreavus
Fix for issue #58050
Hi,
a quick PR to mention in the compiler error message that `?` is a macro operator, as according to issue #58050
It passed `python x.py test src/tools/tidy` locally, as well as the recommendation to run `/x.py test src/test/ui --stage 1 --bless`.
Let me know if anything else is needed.
Allow lang and lib features to share names
Fixes https://github.com/rust-lang/rust/issues/58715.
I didn't add a test, because there's currently no standard lang test feature and I felt apprehensive about adding a permanently unstable feature. Instead, a shared lang/lib feature will be used in https://github.com/rust-lang/rust/pull/57760 and will essentially provide an immediately test.
Update stdsimd
This updates stdsimd to a Rust2015 / Rust2018 compatible version. Once this is merged it should be possible to migrate libcore and libstd to Rust2018. Once that happens, we can just require the 2018 edition in stdsimd.
* A number of `Stdio` related doc examples include running the "rev"
command to illustrate piping commands. The majority of these tests are
marked as `no_run` except for two tests which were not
* Not running these tests is unlikely to cause any negative impact, and
doing so also allows the test suite to pass in environments where the
"rev" command is unavailable
Add vectored read and write support
This functionality has lived for a while in the tokio ecosystem, where
it can improve performance by minimizing copies.
r? @alexcrichton
