On Wed, Sep 3, 2025 at 6:09 AM John Dallman <jgdatsiem...@gmail.com> wrote:
> I'm aware that WASI doesn't support traditional signals > <https://github.com/WebAssembly/WASI/issues/166>. At present, when I > intentionally set off an access violation, I get "RuntimeError: memory > access out of bounds" and a traceback as Node.js exits. > > Is there a way to catch these errors and prevent Node.js exiting? Ideally, > I'd be able to notify the test harness in some way that this had happened. > If this involves JavaScript, please explain slowly and gently: I'm from the > C world and new to web applications. > These can be caught like a standard JavaScript exception by the surrounding test harness JS, something like: try { Module.run_my_c_code(); } catch (e) { // Probably out of bounds access, or divide by zero etc console.log("Error while running run_my_c_code: " + e); } The stack trace attached to the exception may not be very useful, but this gives your test harness a chance to process the failure at least. :D Note that this will only catch WebAssembly accesses outside of linear memory -- a NULL dereference, read or write, will *not* trigger a runtime error -- but any actually out-of-bounds accesses, or other operations like divide by zero that trap, can be caught this way even on a fully optimized production build. You might also look into the SAFE_HEAP build option in emscripten, which runs all memory accesses through a double-check for out-of-bounds or NULL dereference and logs it. Check emscripten's src/settings.js for comments documenting this and other build-time options. -- brooke -- You received this message because you are subscribed to the Google Groups "emscripten-discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to emscripten-discuss+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/emscripten-discuss/CAFnWYTm-3FbJgrnN7CEWX4Fh0e9%3Dc1y7a99B%2BcdEa9zQwpD4yA%40mail.gmail.com.
