rust/library
bors 50872bdb99 Auto merge of #97033 - nbdd0121:unwind3, r=Amanieu
Remove libstd's calls to `C-unwind` foreign functions

Remove all libstd and its dependencies' usage of `extern "C-unwind"`.

This is a prerequiste of a WIP PR which will forbid libraries calling `extern "C-unwind"` functions to be compiled in `-Cpanic=unwind` and linked against `panic_abort` (this restriction is necessary to address soundness bug #96926).
Cargo will ensure all crates are compiled with the same `-Cpanic` but the std is only compiled `-Cpanic=unwind` but needs the ability to be linked into `-Cpanic=abort`.

Currently there are two places where `C-unwind` is used in libstd:
* `__rust_start_panic` is used for interfacing to the panic runtime. This could be `extern "Rust"`
* `_{rdl,rg}_oom`: a shim `__rust_alloc_error_handler` will be generated by codegen to call into one of these; they can also be `extern "Rust"` (in fact, the generated shim is used as `extern "Rust"`, so I am not even sure why these are not, probably because they used to `extern "C"` and was changed to `extern "C-unwind"` when we allow alloc error hooks to unwind, but they really should just be using Rust ABI).

For dependencies, there is only one `extern "C-unwind"` function call, in `unwind` crate. This can be expressed as a re-export.

More dicussions can be seen in the Zulip thread: https://rust-lang.zulipchat.com/#narrow/stream/210922-project-ffi-unwind/topic/soundness.20in.20mixed.20panic.20mode

`@rustbot` label: T-libs F-c_unwind
2022-05-19 04:04:40 +00:00
..
alloc Auto merge of #97033 - nbdd0121:unwind3, r=Amanieu 2022-05-19 04:04:40 +00:00
backtrace@b02ed04a7e
core Auto merge of #95643 - WaffleLapkin:ptr_convenience, r=joshtriplett 2022-05-18 23:18:03 +00:00
panic_abort Use Rust ABI for __rust_start_panic and _{rdl,rg}_oom 2022-05-14 02:53:59 +01:00
panic_unwind Use Rust ABI for __rust_start_panic and _{rdl,rg}_oom 2022-05-14 02:53:59 +01:00
portable-simd portable-simd: use simd_arith_offset to avoid ptr-int transmutation 2022-04-12 11:09:26 -04:00
proc_macro Remove some unnecessary rustc_allow_const_fn_unstable attributes. 2022-05-13 16:01:18 +10:00
profiler_builtins
rtstartup
rustc-std-workspace-alloc
rustc-std-workspace-core
rustc-std-workspace-std
std Auto merge of #97033 - nbdd0121:unwind3, r=Amanieu 2022-05-19 04:04:40 +00:00
stdarch@28335054b1 Also allow unused macro rules in stdarch 2022-05-10 19:53:22 +02:00
test Auto merge of #95678 - pietroalbini:pa-1.62.0-bootstrap, r=Mark-Simulacrum 2022-04-07 07:34:04 +00:00
unwind Auto merge of #97033 - nbdd0121:unwind3, r=Amanieu 2022-05-19 04:04:40 +00:00