resolve the conflict in compiler/rustc_session/src/parse.rs

2022-03-16T12:12:30+00:00

Signed-off-by: codehorseman

rustc: Fill out remaining parts of C-unwind ABI

2021-08-03T14:06:19+00:00

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.

test: codegen: skip catch-unwind on riscv64

2020-06-04T11:15:26+00:00

It isn't clear to me if this is a bug or not, hence the FIXME

Test catch_unwind vanishing

2020-03-02T11:43:07+00:00

We execpt the try intrinsic to be a direct call if in -Cpanic=abort mode, and that catch_unwind optimizes out if calling a function that does not unwind.

rust/src/test/codegen/catch-unwind.rs, branch 1.66.1

resolve the conflict in compiler/rustc_session/src/parse.rs

rustc: Fill out remaining parts of C-unwind ABI

test: codegen: skip catch-unwind on riscv64

Test catch_unwind vanishing