This commit intends to fill out some of the remaining pieces of the
C-unwind ABI. This has a number of other changes with it though to move
this design space forward a bit. Notably contained within here is:
* On `panic=unwind`, the `extern "C"` ABI is now considered as "may
unwind". This fixes a longstanding soundness issue where if you
`panic!()` in an `extern "C"` function defined in Rust that's actually
UB because the LLVM representation for the function has the `nounwind`
attribute, but then you unwind.
* Whether or not a function unwinds now mainly considers the ABI of the
function instead of first checking the panic strategy. This fixes a
miscompile of `extern "C-unwind"` with `panic=abort` because that ABI
can still unwind.
* The aborting stub for non-unwinding ABIs with `panic=unwind` has been
reimplemented. Previously this was done as a small tweak during MIR
generation, but this has been moved to a separate and dedicated MIR
pass. This new pass will, for appropriate functions and function
calls, insert a `cleanup` landing pad for any function call that may
unwind within a function that is itself not allowed to unwind. Note
that this subtly changes some behavior from before where previously on
an unwind which was caught-to-abort it would run active destructors in
the function, and now it simply immediately aborts the process.
* The `#[unwind]` attribute has been removed and all users in tests and
such are now using `C-unwind` and `#![feature(c_unwind)]`.
I think this is largely the last piece of the RFC to implement.
Unfortunately I believe this is still not stabilizable as-is because
activating the feature gate changes the behavior of the existing `extern
"C"` ABI in a way that has no replacement. My thinking for how to enable
this is that we add support for the `C-unwind` ABI on stable Rust first,
and then after it hits stable we change the behavior of the `C` ABI.
That way anyone straddling stable/beta/nightly can switch to `C-unwind`
safely.
rfc3052 followup: Remove authors field from Cargo manifests
Since RFC 3052 soft deprecated the authors field, hiding it from
crates.io, docs.rs, and making Cargo not add it by default, and it is
not generally up to date/useful information for contributors, we may as well
remove it from crates in this repo.
Since RFC 3052 soft deprecated the authors field anyway, hiding it from
crates.io, docs.rs, and making Cargo not add it by default, and it is
not generally up to date/useful information, we should remove it from
crates in this repo.
Checking that function is const if marked with rustc_const_unstable
Fixes#69630
This one is still missing tests to check the behavior but I checked by hand and it seemed to work.
I would not mind some direction for writing those unit tests!
remove trailing newline
fix: test with attribute but missing const
Update compiler/rustc_passes/src/stability.rs
Co-authored-by: Léo Lanteri Thauvin <leseulartichaut@gmail.com>
Add test for extern functions
fix: using span_help instead of span_suggestion
add test for some ABIs + fmt fix
Update compiler/rustc_passes/src/stability.rs
Co-authored-by: Léo Lanteri Thauvin <leseulartichaut@gmail.com>
Refractor and add test for `impl const`
Add test to make sure no output + cleanup condition
-----------------------------
remove stdcall test, failing CI test
C abi is already tested in this, so it is not that useful to test another one.
The tested code is blind to which specific ABI for now, as long as it's not an intrinsic one
E0716: clarify that equivalent code example is erroneous
In E0716, there is a code block that is equivalent to the erroneous
code example. Especially when viewed with `rustc --explain`, it's
not obvious that it is also erroneous, and some users have been
confused when they try to change their code to match the erroneous
equivalent.
`@rustbot` label +A-diagnostics +D-newcomer-roadblock +T-compiler
In E0716, there is a code block that is equivalent to the erroneous
code example. Especially when viewed with `rustc --explain`, it's
not obvious that it is also erroneous, and some users have been
confused when they try to change their code to match the erroneous
equivalent.
Check the number of generic lifetime and const parameters of intrinsics
This pull request fixes#85855. The current code for type checking intrinsics only checks the number of generic _type_ parameters, but does not check for an incorrect number of lifetime or const parameters, which can cause problems later on, such as the ICE in #85855, where the code thought that it was looking at a type parameter but found a lifetime parameter:
```
error: internal compiler error: compiler/rustc_middle/src/ty/generics.rs:188:18:
expected type parameter, but found another generic parameter
```
The changes in this PR add checks for the number of lifetime and const parameters, expand the scope of `E0094` to also apply to these cases, and improve the error message by properly pluralizing the number of expected generic parameters.
Permit zero non-zero-field on transparent types
Fixes#77841
This makes the transparent fields meet the below:
> * A `repr(transparent)` type `T` must meet the following rules:
> * It may have any number of 1-ZST fields
> * In addition, it may have at most one other field of type U
r? `@nikomatsakis`
When having the order
```
foo.bar(); // we can now use this method since i32 implements the Foo trait
[...]
impl Foo for i32
```
the `// we can now use this method` comment is less clear to me.
Update BARE_TRAIT_OBJECT and ELLIPSIS_INCLUSIVE_RANGE_PATTERNS to errors in Rust 2021
This addresses https://github.com/rust-lang/rust/pull/81244 by updating two lints to errors in the Rust 2021 edition.
r? `@estebank`
further split up const_fn feature flag
This continues the work on splitting up `const_fn` into separate feature flags:
* `const_fn_trait_bound` for `const fn` with trait bounds
* `const_fn_unsize` for unsizing coercions in `const fn` (looks like only `dyn` unsizing is still guarded here)
I don't know if there are even any things left that `const_fn` guards... at least libcore and liballoc do not need it any more.
`@oli-obk` are you currently able to do reviews?
Stablize `non-ascii-idents`
This is the stablization PR for RFC 2457. Currently this is waiting on fcp in [tracking issue](https://github.com/rust-lang/rust/issues/55467).
r? `@Manishearth`
Yuki Okushi