rust/library
bors b3800860e1 Auto merge of #93101 - Mark-Simulacrum:library-backtrace, r=yaahc
Support configuring whether to capture backtraces at runtime

Tracking issue: https://github.com/rust-lang/rust/issues/93346

This adds a new API to the `std::panic` module which configures whether and how the default panic hook will emit a backtrace when a panic occurs.

After discussion with `@yaahc` on [Zulip](https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/backtrace.20lib.20vs.2E.20panic), this PR chooses to avoid adjusting or seeking to provide a similar API for the (currently unstable) std::backtrace API. It seems likely that the users of that API may wish to expose more specific settings rather than just a global one (e.g., emulating the `env_logger`, `tracing` per-module configuration) to avoid the cost of capture in hot code. The API added here could plausibly be copied and/or re-exported directly from std::backtrace relatively easily, but I don't think that's the right call as of now.

```rust
mod panic {
    #[derive(Copy, Clone, Debug, PartialEq, Eq)]
    #[non_exhaustive]
    pub enum BacktraceStyle {
        Short,
        Full,
        Off,
    }
    fn set_backtrace_style(BacktraceStyle);
    fn get_backtrace_style() -> Option<BacktraceStyle>;
}
```

Several unresolved questions:

* Do we need to move to a thread-local or otherwise more customizable strategy for whether to capture backtraces? See [this comment](https://github.com/rust-lang/rust/pull/79085#issuecomment-727845826) for some potential use cases for this.
   * Proposed answer: no, leave this for third-party hooks.
* Bikeshed on naming of all the options, as usual.
* Should BacktraceStyle be moved into `std::backtrace`?
   * It's already somewhat annoying to import and/or re-type the `std::panic::` prefix necessary to use these APIs, probably adding a second module to the mix isn't worth it.

Note that PR #79085 proposed a much simpler API, but particularly in light of the desire to fully replace setting environment variables via `env::set_var` to control the backtrace API, a more complete API seems preferable. This PR likely subsumes that one.
2022-02-02 22:03:23 +00:00
..
alloc Rollup merge of #92887 - pietroalbini:pa-bootstrap-update, r=Mark-Simulacrum 2022-01-30 08:37:46 -08:00
backtrace@b02ed04a7e Updated backtrace submodule 2021-11-02 12:31:34 +01:00
core Rollup merge of #93493 - GKFX:char-docs-2, r=scottmcm 2022-02-02 07:11:07 +01:00
panic_abort Switch all libraries to the 2021 edition 2021-12-23 19:03:47 +08:00
panic_unwind adapt L4Bender implementation 2022-01-21 16:50:33 +01:00
portable-simd Merge commit '533f0fc81ab9ba097779fcd27c8f9ea12261fef5' into psimd 2021-12-17 15:10:53 +08:00
proc_macro Auto merge of #92598 - Badel2:panic-update-hook, r=yaahc 2022-01-16 02:18:42 +00:00
profiler_builtins Switch all libraries to the 2021 edition 2021-12-23 19:03:47 +08:00
rtstartup Bump bootstrap compiler to 1.50 beta 2020-12-30 09:27:19 -05:00
rustc-std-workspace-alloc Switch all libraries to the 2021 edition 2021-12-23 19:03:47 +08:00
rustc-std-workspace-core Switch all libraries to the 2021 edition 2021-12-23 19:03:47 +08:00
rustc-std-workspace-std Switch all libraries to the 2021 edition 2021-12-23 19:03:47 +08:00
std Auto merge of #93101 - Mark-Simulacrum:library-backtrace, r=yaahc 2022-02-02 22:03:23 +00:00
stdarch@eaee02ffdf Update stdarch submodule 2022-01-28 12:46:22 +00:00
test Change Termination::report return type to ExitCode 2022-01-28 12:53:36 -08:00
unwind Switch all libraries to the 2021 edition 2021-12-23 19:03:47 +08:00