1# siginfo.m4 serial 1 (gettext-0.11)
2dnl Copyright (C) 2001-2002 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7# Determine how to determine the precise cause of a signal, for example
8# division by zero.
9# - SUSV2 and POSIX specify the use of sigaction with SA_SIGINFO and a member
10#   void (*)(int sig, siginfo_t *info, void *context) sa_sigaction.
11#   Linux (2.2.x and newer) and Solaris implement this.
12#   Linux (2.4.x and newer) on i386, m68k, sparc, sparc64, ia64 actually
13#   deliver FPE_INTDIV.
14# - Without SA_SIGINFO:
15#   - Linux on m68k calls the handler as
16#     void (*)(int sig, int code, struct sigcontext* scp).
17#     For division by zero, code would be VEC_ZERODIV<<2.
18#   - Linux on sparc calls the handler either as
19#     void (*)(int sig, int code, struct sigcontext* scp),
20#     code for division by zero would be SUBSIG_IDIVZERO, or as
21#     void (*)(int sig, siginfo_t *info, void *context).
22#     Which one depends on a process specific flag in the kernel.
23#   - Linux on sparc64 always calls the handler as
24#     void (*)(int sig, siginfo_t *info, void *context).
25#   - FreeBSD on i386 calls the handler as
26#     void (*)(int sig, int code, void* scp, char* addr).
27#     For division by zero, code would be FPE_INTDIV.
28#   - SunOS 4 calls the handler as
29#     void (*)(int sig, int code, void* scp, char* addr).
30#   - Solaris?
31#   - Irix 5, OSF/1, AIX call the handler as
32#     void (*)(int sig, int code, struct sigcontext *scp).
33# These are so many OS and CPU dependencies that we don't bother, and rely
34# only on SA_SIGINFO.
35AC_DEFUN([gt_SIGINFO],
36[
37  AC_CACHE_CHECK([for signal handlers with siginfo_t], gt_cv_siginfo_t,
38    [AC_TRY_COMPILE([
39#include <signal.h>], [
40struct sigaction action;
41siginfo_t info;
42action.sa_flags = SA_SIGINFO;
43action.sa_sigaction = (void *) 0;
44], gt_cv_siginfo_t=yes, gt_cv_siginfo_t=no)])
45  if test $gt_cv_siginfo_t = yes; then
46    AC_DEFINE(HAVE_SIGINFO, 1,
47      [Define to 1 if <signal.h> defines the siginfo_t type,
48   and struct sigaction has the sa_sigaction member and the SA_SIGINFO flag.])
49  fi
50])
51