How to get rid of panic handler?

community
1 
#![no_std]
#![no_main]

use core::panic::PanicInfo;

#[panic_handler]
fn panic(_info: &PanicInfo) -> ! {
    loop{}
}

#[no_mangle]
pub extern "C" fn _start() -> ! {
    let  mut x: i32 = 3;
    loop{
        x = x + 1;
    }
}

Hi all,
As I start with RUST on risc-v, I am able to compile above and run in my target. Can someone help me on how to get rid of the panic handler? I am new to rust & it seems RUST enforces a panic handler I may be wrong. so in RUST is panic hanlder mandatory? if not, what changes would help me to get rid of the panic handler?

2

It is indeed required, because certain things (e.g. indexing) can trigger panics even if it is not explicit.

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3

In your specific example the x + 1 will panic once it overflows if debug assertions are enabled.

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4

Thanks, but i want to build my code WITHOUT any library. Hence, is there a way to get away this panic handler inturn get away with the core library? Is it possible? or its mandatory to have panic handler in RUST?

5

It is mandatory to have some panic handler. The handler can crash, abort the program, or loop forever, but it must exist.

6

In this case you can use #![no_core] in addition to #![no_std]. Not sure if this is what you want, however, since in this case you'll have to provide literally every reference to the used compiler intrinsics.

It's mandatory even for no_core, yes, since there are some operations which has the implicit panic semantics.

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7

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