1 files changed, 100 insertions, 0 deletions
diff --git a/m4/signal_h.m4 b/m4/signal_h.m4
new file mode 100644
index 0000000..4c05c62
--- /dev/null
+++ b/m4/signal_h.m4
@@ -0,0 +1,100 @@
+# signal_h.m4 serial 22
+dnl Copyright (C) 2007-2022 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN_ONCE([gl_SIGNAL_H],
+[
+  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
+  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_REQUIRE([AC_C_RESTRICT])
+])
+
+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
+])
+
+# gl_SIGNAL_MODULE_INDICATOR([modulename])
+# sets the shell variable that indicates the presence of the given module
+# to a C preprocessor expression that will evaluate to 1.
+# This macro invocation must not occur in macros that are AC_REQUIREd.
+AC_DEFUN([gl_SIGNAL_MODULE_INDICATOR],
+[
+  dnl Ensure to expand the default settings once only.
+  gl_SIGNAL_H_REQUIRE_DEFAULTS
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+# Initializes the default values for AC_SUBSTed shell variables.
+# This macro must not be AC_REQUIREd.  It must only be invoked, and only
+# outside of macros or in macros that are not AC_REQUIREd.
+AC_DEFUN([gl_SIGNAL_H_REQUIRE_DEFAULTS],
+[
+  m4_defun(GL_MODULE_INDICATOR_PREFIX[_SIGNAL_H_MODULE_INDICATOR_DEFAULTS], [
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_PTHREAD_SIGMASK])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_RAISE])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SIGNAL_H_SIGPIPE])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SIGPROCMASK])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SIGACTION])
+  ])
+  m4_require(GL_MODULE_INDICATOR_PREFIX[_SIGNAL_H_MODULE_INDICATOR_DEFAULTS])
+  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
+])
+
+AC_DEFUN([gl_SIGNAL_H_DEFAULTS],
+[
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  HAVE_POSIX_SIGNALBLOCKING=1; AC_SUBST([HAVE_POSIX_SIGNALBLOCKING])
+  HAVE_PTHREAD_SIGMASK=1;      AC_SUBST([HAVE_PTHREAD_SIGMASK])
+  HAVE_RAISE=1;                AC_SUBST([HAVE_RAISE])
+  HAVE_SIGSET_T=1;             AC_SUBST([HAVE_SIGSET_T])
+  HAVE_SIGINFO_T=1;            AC_SUBST([HAVE_SIGINFO_T])
+  HAVE_SIGACTION=1;            AC_SUBST([HAVE_SIGACTION])
+  HAVE_STRUCT_SIGACTION_SA_SIGACTION=1;
+                               AC_SUBST([HAVE_STRUCT_SIGACTION_SA_SIGACTION])
+  HAVE_TYPE_VOLATILE_SIG_ATOMIC_T=1;
+                               AC_SUBST([HAVE_TYPE_VOLATILE_SIG_ATOMIC_T])
+  HAVE_SIGHANDLER_T=1;         AC_SUBST([HAVE_SIGHANDLER_T])
+  REPLACE_PTHREAD_SIGMASK=0;   AC_SUBST([REPLACE_PTHREAD_SIGMASK])
+  REPLACE_RAISE=0;             AC_SUBST([REPLACE_RAISE])
+])