(Environment: gcc/g++ 4.6.1 in -std=gnu++0x mode on Linux 3.0 / x86_64...)
#include <stdlib.h>
#include <signal.h>
#include <iostream>
using namespace std;
class SegmentationFault {};
void ThrowSegmentationFault(int)
{
throw SegmentationFault();
}
void ohno(char* x)
{
*x = 42;
}
int main()
{
signal(SIGSEGV, ThrowSegmentationFault);
try
{
ohno(0);
}
catch (const SegmentationFault&)
{
cout << "success" << endl;
}
}
By compiling the above with the -fnon-call-exceptions flag, it allows the SIGSEGV signal handler to throw an exception, and when run it will print "success". The documentation of the -fnon-call-exceptions gcc flag reads as follows:
Generate code that allows trapping instructions to throw exceptions. Note that this requires platform-specific runtime support that does not exist everywhere. Moreover, it only allows trapping instructions to throw exceptions, i.e. memory references or floating point instructions. It does not allow exceptions to be thrown from arbitrary signal handlers such as SIGALRM.
My question is which of the signals are trapping instructions and which are not?
#define SIGHUP 1
#define SIGINT 2
#define SIGQUIT 3
#define SIGILL 4
#define SIGTRAP 5
#define SIGABRT 6
#define SIGIOT 6
#define SIGBUS 7
#define SIGFPE 8
#define SIGKILL 9
#define SIGUSR1 10
#define SIGSEGV 11
#define SIGUSR2 12
#define SIGPIPE 13
#define SIGALRM 14
#define SIGTERM 15
#define SIGSTKFLT 16
#define SIGCHLD 17
#define SIGCONT 18
#define SIGSTOP 19
#define SIGTSTP 20
#define SIGTTIN 21
#define SIGTTOU 22
#define SIGURG 23
#define SIGXCPU 24
#define SIGXFSZ 25
#define SIGVTALRM 26
#define SIGPROF 27
#define SIGWINCH 28
#define SIGIO 29
#define SIGPOLL SIGIO
/*
#define SIGLOST 29
*/
#define SIGPWR 30
#define SIGSYS 31
#define SIGUNUSED 31
