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author | Alan Wu <XrXr@users.noreply.github.com> | 2023-02-02 14:02:36 -0500 |
---|---|---|
committer | Alan Wu <XrXr@users.noreply.github.com> | 2023-02-02 15:16:09 -0500 |
commit | 3b83b265f11965582d4b9b439eff8a501792ab68 (patch) | |
tree | 0fb9f50f4dfc98f8c165920c20954d5369f1078e | |
parent | 5b34839b0f9d164552f8da41b6ced2db1d2af3be (diff) | |
download | ruby-3b83b265f11965582d4b9b439eff8a501792ab68.tar.gz |
YJIT: Crash with rb_bug() when panicking
Helps with getting good bug reports in the wild. Intended to be
backported to the 3.2.x series.
-rw-r--r-- | yjit/bindgen/src/main.rs | 3 | ||||
-rw-r--r-- | yjit/src/cruby_bindings.inc.rs | 1 | ||||
-rw-r--r-- | yjit/src/yjit.rs | 29 |
3 files changed, 31 insertions, 2 deletions
diff --git a/yjit/bindgen/src/main.rs b/yjit/bindgen/src/main.rs index 35b09e1abc..8d29d42bf7 100644 --- a/yjit/bindgen/src/main.rs +++ b/yjit/bindgen/src/main.rs @@ -88,6 +88,9 @@ fn main() { // This function prints info about a value and is useful for debugging .allowlist_function("rb_obj_info_dump") + // For crashing + .allowlist_function("rb_bug") + // From shape.h .allowlist_function("rb_shape_get_shape_id") .allowlist_function("rb_shape_get_shape_by_id") diff --git a/yjit/src/cruby_bindings.inc.rs b/yjit/src/cruby_bindings.inc.rs index 128b249e3b..a405d2aca6 100644 --- a/yjit/src/cruby_bindings.inc.rs +++ b/yjit/src/cruby_bindings.inc.rs @@ -1074,6 +1074,7 @@ extern "C" { pub fn rb_singleton_class(obj: VALUE) -> VALUE; pub fn rb_get_alloc_func(klass: VALUE) -> rb_alloc_func_t; pub fn rb_method_basic_definition_p(klass: VALUE, mid: ID) -> ::std::os::raw::c_int; + pub fn rb_bug(fmt: *const ::std::os::raw::c_char, ...) -> !; pub fn rb_gc_writebarrier(old: VALUE, young: VALUE); pub fn rb_class_get_superclass(klass: VALUE) -> VALUE; pub static mut rb_mKernel: VALUE; diff --git a/yjit/src/yjit.rs b/yjit/src/yjit.rs index 4850dca7a8..305778a939 100644 --- a/yjit/src/yjit.rs +++ b/yjit/src/yjit.rs @@ -50,13 +50,13 @@ pub extern "C" fn rb_yjit_init_rust() { // Catch panics to avoid UB for unwinding into C frames. // See https://doc.rust-lang.org/nomicon/exception-safety.html - // TODO: set a panic handler so the we don't print a message - // everytime we panic. let result = std::panic::catch_unwind(|| { Invariants::init(); CodegenGlobals::init(); YjitExitLocations::init(); + rb_bug_panic_hook(); + // YJIT enabled and initialized successfully YJIT_ENABLED.store(true, Ordering::Release); }); @@ -67,6 +67,31 @@ pub extern "C" fn rb_yjit_init_rust() { } } +/// At the moment, we abort in all cases we panic. +/// To aid with getting diagnostics in the wild without requiring +/// people to set RUST_BACKTRACE=1, register a panic hook that crash using rb_bug(). +/// rb_bug() might not be as good at printing a call trace as Rust's stdlib, but +/// it dumps some other info that might be relevant. +/// +/// In case we want to do start doing fancier exception handling with panic=unwind, +/// we can revisit this later. For now, this helps to get us good bug reports. +fn rb_bug_panic_hook() { + use std::panic; + use std::io::{stderr, Write}; + + // Probably the default hook. We do this very early during process boot. + let previous_hook = panic::take_hook(); + + panic::set_hook(Box::new(move |panic_info| { + // Not using `eprintln` to avoid double panic. + let _ = stderr().write_all(b"ruby: YJIT has panicked. More info to follow...\n"); + + previous_hook(panic_info); + + unsafe { rb_bug(b"YJIT panicked\0".as_ref().as_ptr() as *const raw::c_char); } + })); +} + /// Called from C code to begin compiling a function /// NOTE: this should be wrapped in RB_VM_LOCK_ENTER(), rb_vm_barrier() on the C side #[no_mangle] |