On Tue, Feb 17, 2004 at 11:11:20AM -0800, David L wrote: > I found some example code regarding how to use backtrace from signal > handlers at: http://www.linuxjournal.com/article.php?sid=6391 . That > example code compiled with warnings but no errors using old versions of g++ > (eg: egcs-2.91), but now has an error: > > foo.cc: In function `void bt_sighandler(int, sigcontext)': > foo.cc:26: `exit' undeclared (first use this function) > foo.cc:26: (Each undeclared identifier is reported only once for each > function > it appears in.) It's illegal to use a function in C++ prior to declaring it. `exit' is declared in "stdlib.h". > foo.cc: In function `int main()': > foo.cc:56: invalid conversion from `void*' to `void (*)(int)' > > What is the proper way to set up a signal handler with a 2nd argument > (sigcontext )? See `man sigaction'. You want to assign to sa_sigaction instead of sa_handler as shown in listing 3 of the article you just referenced above. But leave out the stupid old style cast and just make sure bt_sighandler has the expected signature. > #include <stdio.h> > #include <signal.h> > #include <execinfo.h> > > void bt_sighandler(int sig, struct sigcontext ctx) { [...] > exit(0); > } [...] > sa.sa_handler = (void *)bt_sighandler; > sigemptyset(&sa.sa_mask); > sa.sa_flags = SA_RESTART; > > sigaction(SIGSEGV, &sa, NULL); > sigaction(SIGUSR1, &sa, NULL); > /* ... add any other signal here */ > Cheers. -- Claudio Bley ASCII ribbon campaign (") Debian GNU/Linux user - against HTML email X http://www.cs.uni-magdeburg.de/~bley/ & vCards / \
