+ AC_REQUIRE([gl_CHECK_TYPE_SIGSET_T])
+ gl_NEXT_HEADERS([signal.h])
+
+# AIX declares sig_atomic_t to already include volatile, and C89 compilers
+# then choke on 'volatile sig_atomic_t'. C99 requires that it compile.
+ AC_CHECK_TYPE([volatile sig_atomic_t], [],
+ [HAVE_TYPE_VOLATILE_SIG_ATOMIC_T=0], [[
+#include <signal.h>
+ ]])
+
+ dnl Ensure the type pid_t gets defined.
+ AC_REQUIRE([AC_TYPE_PID_T])
+
+ AC_REQUIRE([AC_TYPE_UID_T])
+
+ dnl Persuade glibc <signal.h> to define sighandler_t.
+ AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+ AC_CHECK_TYPE([sighandler_t], [], [HAVE_SIGHANDLER_T=0], [[
+#include <signal.h>
+ ]])
+
+ dnl Check for declarations of anything we want to poison if the
+ dnl corresponding gnulib module is not in use.
+ gl_WARN_ON_USE_PREPARE([[#include <signal.h>
+ ]], [pthread_sigmask sigaction
+ sigaddset sigdelset sigemptyset sigfillset sigismember
+ sigpending sigprocmask])
+])
+
+AC_DEFUN([gl_CHECK_TYPE_SIGSET_T],
+[
+ AC_CHECK_TYPES([sigset_t],
+ [gl_cv_type_sigset_t=yes], [gl_cv_type_sigset_t=no],
+ [[
+ #include <signal.h>
+ /* Mingw defines sigset_t not in <signal.h>, but in <sys/types.h>. */
+ #include <sys/types.h>
+ ]])
+ if test $gl_cv_type_sigset_t != yes; then
+ HAVE_SIGSET_T=0
+ fi