1 files changed, 51 insertions, 0 deletions
diff --git a/m4/sys_wait_h.m4 b/m4/sys_wait_h.m4
new file mode 100644
index 0000000..0aa4f7c
--- /dev/null
+++ b/m4/sys_wait_h.m4
@@ -0,0 +1,51 @@
+# sys_wait_h.m4 serial 9
+dnl Copyright (C) 2008-2022 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_SYS_WAIT_H],
+[
+  AC_REQUIRE([gl_SYS_WAIT_H_DEFAULTS])
+
+  dnl <sys/wait.h> is always overridden, because of GNULIB_POSIXCHECK.
+  gl_CHECK_NEXT_HEADERS([sys/wait.h])
+
+  dnl Ensure the type pid_t gets defined.
+  AC_REQUIRE([AC_TYPE_PID_T])
+
+  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 <sys/wait.h>]],
+    [waitpid])
+])
+
+# gl_SYS_WAIT_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_SYS_WAIT_MODULE_INDICATOR],
+[
+  dnl Ensure to expand the default settings once only.
+  gl_SYS_WAIT_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_SYS_WAIT_H_REQUIRE_DEFAULTS],
+[
+  m4_defun(GL_MODULE_INDICATOR_PREFIX[_SYS_WAIT_H_MODULE_INDICATOR_DEFAULTS], [
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_WAITPID])
+  ])
+  m4_require(GL_MODULE_INDICATOR_PREFIX[_SYS_WAIT_H_MODULE_INDICATOR_DEFAULTS])
+  AC_REQUIRE([gl_SYS_WAIT_H_DEFAULTS])
+])
+
+AC_DEFUN([gl_SYS_WAIT_H_DEFAULTS],
+[
+  dnl Assume proper GNU behavior unless another module says otherwise.
+])