catch native exception in dotnet core

Question

in a dotnet core application that uses pinvoke and runs on linux, when c++ throws - for example - std::runtime_error - we get:

terminate called recursively
terminate called after throwing an instance of 'terminate called after throwing an instance of 'std::runtime_error*'
Aborted (core dumped)

even though the invocation of the externed c++ method is wrapped in a try catch block in the managed code.

how can this be caught and treated in the dotnet core managed code?

Note the response https://stackoverflow.com/a/151329/613130 . You should use a `try { ... } catch { ... }` (without exception type) — xanatos, Jun 14 '18 at 08:55
Please note that my question refers to dotnet core executing on linux, not dotnet framework on windows. Is this still a duplicate? — lev haikin, Jun 14 '18 at 18:16
@levhaikin Have you tried with a blanked `try... catch {}` with no type? — xanatos, Jun 15 '18 at 06:18
I tried the blanked try/catch. didn't help. I can't find anything about this issue anywhere... any help?... — lev haikin, Jul 19 '18 at 09:57

score 4 · Accepted Answer · answered Sep 12 '18 at 13:15

I set-up this Minimal, Complete and Verifiable example that demonstrates how native exceptions are NOT caught whatsoever by managed C# .NET Core code, on Linux.

As described in the issue I opened for dotnet/coreclr, I've tried (m)any possible weapon(s) in the arsenal, to no avail.

The direct answer given by dotnet team was:

We do not support exception handling interop on Unix. There is no good way to do it. The Mono project has a great write up on it here: http://www.mono-project.com/docs/advanced/pinvoke/#runtime-exception-propagation . The same reasoning applies to .NET Core.

The Mono project's solution, which is also recommended by the dotnet team, is:

C++ exceptions will need to be mapped into an “out” parameter or a return value, so that managed code can know what error occurred, and (optionally) throw a managed exception to “propagate” the original C++ exception.

That's what we eneded up implementing and, well, it works :).

catch native exception in dotnet core

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