/*
 * NOTE TO FreeBSD users. Install libexecinfo from
 * ports/devel/libexecinfo and add -lexecinfo to LDFLAGS
 * to add backtrace support.
 */
#include "e.h"

#ifdef HAVE_EXECINFO_H
# include <execinfo.h>
#endif

static volatile Eina_Bool _e_x_composite_shutdown_try = 0;

static void
_e_x_composite_shutdown(void)
{
//   Ecore_X_Display *dpy;
   Ecore_X_Window root;

   if (_e_x_composite_shutdown_try) return; /* we failed :-( */
   _e_x_composite_shutdown_try = 1;

//   dpy = ecore_x_display_get();
   root = ecore_x_window_root_first_get();

   /* ignore errors, we really don't care at this point */
   ecore_x_composite_unredirect_subwindows(root, ECORE_X_COMPOSITE_UPDATE_MANUAL);
   _e_x_composite_shutdown_try = 0;
}

#define _e_write_safe(fd, buf) _e_write_safe_int(fd, buf, sizeof(buf))

static void
_e_write_safe_int(int fd, const char *buf, size_t size)
{
   while (size > 0)
     {
	ssize_t done = write(fd, buf, size);
	if (done >= 0)
	  {
	     buf += done;
	     size -= done;
	  }
	else
	  {
	     if ((errno == EAGAIN) || (errno == EINTR))
	       continue;
	     else
	       {
		  perror("write");
		  return;
	       }
	  }
     }
}

static void
_e_gdb_print_backtrace(int fd)
{
   char cmd[1024];
   size_t size;
   int ret;

   // FIXME: we are in a segv'd state. do as few function calls and things
   // depending on a known working state as possible. this also prevents the
   // white box allowing recovery or deeper gdbing, thus until this works
   // properly, it's disabled (properly means always reliable, always
   // printf bt and allows e to continue and pop up box, perferably allowing
   // debugging in the gui etc. etc.
   return;

   if (getenv("E_NO_GDB_BACKTRACE"))
     return;

   size = snprintf(cmd, sizeof(cmd),
		   "gdb --pid=%d "
		   "-ex 'thread apply all bt' "
		   "-ex detach -ex quit", getpid());

   if (size >= sizeof(cmd))
     return;

   _e_write_safe(fd, "EXECUTING GDB AS: ");
   _e_write_safe_int(fd, cmd, size);
   _e_write_safe(fd, "\n");
   ret = system(cmd); // TODO: use popen() or fork()+pipe()+exec() and save to 'fd'
}

#define _e_backtrace(msg) _e_backtrace_int(2, msg, sizeof(msg))
static void
_e_backtrace_int(int fd, const char *msg, size_t msg_len)
{
   char attachmsg[1024];
   void *array[255];
   size_t size;

   return; // disable. causes hangs and problems

   _e_write_safe_int(fd, msg, msg_len);
   _e_write_safe(fd, "\nBEGIN TRACEBACK\n");
   size = backtrace(array, 255);
   backtrace_symbols_fd(array, size, fd);
   _e_write_safe(fd, "END TRACEBACK\n");

   size = snprintf(attachmsg, sizeof(attachmsg),
		   "debug with: gdb --pid=%d\n", getpid());
   if (size < sizeof(attachmsg))
     _e_write_safe_int(fd, attachmsg, size);

   _e_gdb_print_backtrace(fd);
}

/* a tricky little devil, requires e and it's libs to be built
 * with the -rdynamic flag to GCC for any sort of decent output.
 */
EAPI void
e_sigseg_act(int x __UNUSED__, siginfo_t *info __UNUSED__, void *data __UNUSED__)
{
   _e_backtrace("**** SEGMENTATION FAULT ****");
   _e_x_composite_shutdown();
   ecore_x_pointer_ungrab();
   ecore_x_keyboard_ungrab();
   ecore_x_ungrab();
   ecore_x_sync();
   e_alert_show(SIGSEGV);
}

EAPI void
e_sigill_act(int x __UNUSED__, siginfo_t *info __UNUSED__, void *data __UNUSED__)
{
   _e_backtrace("**** ILLEGAL INSTRUCTION ****");
   _e_x_composite_shutdown();
   ecore_x_pointer_ungrab();
   ecore_x_keyboard_ungrab();
   ecore_x_ungrab();
   ecore_x_sync();
   e_alert_show(SIGILL);
}

EAPI void
e_sigfpe_act(int x __UNUSED__, siginfo_t *info __UNUSED__, void *data __UNUSED__)
{
   _e_backtrace("**** FLOATING POINT EXCEPTION ****");
   _e_x_composite_shutdown();
   ecore_x_pointer_ungrab();
   ecore_x_keyboard_ungrab();
   ecore_x_ungrab();
   ecore_x_sync();
   e_alert_show(SIGFPE);
}

EAPI void
e_sigbus_act(int x __UNUSED__, siginfo_t *info __UNUSED__, void *data __UNUSED__)
{
   _e_backtrace("**** BUS ERROR ****");
   _e_x_composite_shutdown();
   ecore_x_pointer_ungrab();
   ecore_x_keyboard_ungrab();
   ecore_x_ungrab();
   ecore_x_sync();
   e_alert_show(SIGBUS);
}

EAPI void
e_sigabrt_act(int x __UNUSED__, siginfo_t *info __UNUSED__, void *data __UNUSED__)
{
   _e_backtrace("**** ABORT ****");
   _e_x_composite_shutdown();
   ecore_x_pointer_ungrab();
   ecore_x_keyboard_ungrab();
   ecore_x_ungrab();
   ecore_x_sync();
   e_alert_show(SIGABRT);
}