Improve C++ Exception Handling with Fishhook

[philipphofmann]

We could use fishhook to enhance C++ exception. Currently, the Sentry SDK uses dlsym to look up __cxa_throw.

sentry-cocoa/Sources/SentryCrash/Recording/Monitors/SentryCrashMonitor_CPPException.cpp

Line 92 in f31a3ef

orig_cxa_throw = (cxa_throw_type)dlsym(RTLD_NEXT, "__cxa_throw");

This approach falls short in applications with multiple dynamic libraries, as exceptions thrown in those separate modules aren’t caught by the main exception handler, but it works fine when Sentry is linked statically into the same module.

By using fishhook, which allows functions to be “hooked” by name as they are loaded across various modules, we could dynamically find and intercept all instances of __cxa_throw, even in different dynamic libraries. This would provide more comprehensive and consistent exception handling across an app’s runtime, regardless of the number of C++ modules or how they’re linked.

We used fishhook in the past for trying to get async stacktraces (#998), but we removed it again because it was not working reliably. The problem wasn't fishhook, but how we used it. We now use backtrace_async for async stacktrace in Swift.

This could maybe help with:

• C++ NoMethodError Exception does not provide anything useful in sentry.io UI #935
• EXC_BAD_ACCESS from C++ has no thread with current or crashed #1267
• C++ exception is not nicely displayed as stack lines in the UI #1562
• Fatal C++ exceptions have missing stack trace #4226