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
..
benches	mv std libs to library/	2020-07-27 19:51:13 -05:00
primitive_docs	Add primitive documentation to libcore	2021-09-12 02:23:08 +00:00
src	Auto merge of #93101 - Mark-Simulacrum:library-backtrace, r=yaahc	2022-02-02 22:03:23 +00:00
tests	Move unstable is_{arch}_feature_detected! macros to std::arch	2022-01-28 09:51:46 +00:00
build.rs	std: Get the standard library compiling for wasm64	2021-11-10 08:35:42 -08:00
Cargo.toml	Update compiler_builtins to fix duplicate symbols in armv7-linux-androideabi rlib	2022-01-29 08:28:52 -08:00