CODEWITHSUNDEEP
c++linuxgccc++17libstdc++
Andrew Tomazos
Andrew Tomazos

Reputation: 68698

Running function on C++ throw in gcc/linux?

Is there any way in gcc/linux to have a user-defined function called immediately after any C++ throw statement executes, but before the stack is unwound to the catch? (I want to capture a stacktrace.)

(In gdb I can write catch throw. Anyway to do that programmatically short of a compiler extension?)

Upvotes: 1

Views: 278

Answers (2)

Marshall Clow
Marshall Clow

Reputation: 16680

at your throwing site you can do this:

try { throw 13; }
catch (...) { print_stack_trace(); rethrow;}

Of course, if you want this everywhere, then you'll need some automated editing to put it there (or a macro like this): untested code

#define THROW(x) do { \
                   try {throw(x);} \
                   catch(...) { print_stack_trace(); rethrow;} \
                 } while(false)

or even simpler:

#define THROW(x) do { \
                   print_stack_trace(); \
                   throw(x); \
                 } while(false)

Upvotes: 0

Acorn
Acorn

Reputation: 26166

If you are using libstdc++, you could override __cxa_throw().

For instance:

#include <cstring>

void __cxa_throw(void *, void *, void (*)(void *)) {
    std::puts("bad luck");
}

int main() {
    throw 13;
}

Upvotes: 2

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