Handle SIG* and panic() for non-rust crashes

[glossy rune]

• Handle SIG* in rust-code and panic() for non-rust crashes
• panic() will print a good stacktrace of the crash :3

[radiant iron]

I would love this, but I don't know how to achieve this

[glossy rune]

Somthing like this https://blog.logrocket.com/guide-signal-handling-rust/

We can hook SIGABRT, SIGTERM, SIGSEGV etc.. to call painc() in those handlers

[radiant iron]

unfortunately these libc calls are not available on windows

[radiant iron]

basically, signal handlers run in the kernel space, and so they don't have access to any usermode call. here it explains how to work around this by manipulating the stack but it's really hacky https://feepingcreature.github.io/handling.html

I wouldn't be surprised if I bluescreen my pc writing and debugging this lol

[radiant iron]

I just looked up the original "classic" ALVR code, ported back the crash handler code and it worked!

[glossy rune]

Classic? :o

[radiant iron]

yeah, polygraphene/ALVR

[glossy rune]

Ohh ! Awesome!

[radiant iron]

this is what I get:

can't seem to add file name and line info, but that's already quite useful

also this is windows only, linux needs to use some other code

[radiant iron]

I guess this suggestion can be marked as resolved 🙂 For the client we are going to remove all c++ code soon so no need to work on that I think. and for PhoneVR you can add support yourself, just take insporation from the last commit I pushed

oh btw,

panic() will print a good stacktrace of the crash :3
This not true if the crash happened on the C++ side, the symbols will be mangled in a way that Rust can't understand and so it will have <unknown> entries. So in the last commit I included a C++ stacktrace library.

[glossy rune]

think filename and line no is specifc to rust implementation (rustc ig)

[glossy rune]

looks good already, maybe those ?? are those symbols which are not there in libaries i guess

[glossy rune]

but i thought that mangling is same for both rust and c++, since on crash android/Tombstone crashes include both Rust and C++ very nicly