1 files changed, 59 insertions, 0 deletions
diff --git a/autoconf/ast_func_fork.m4 b/autoconf/ast_func_fork.m4
new file mode 100644
index 000000000..37bf0c397
--- /dev/null
+++ b/autoconf/ast_func_fork.m4
@@ -0,0 +1,59 @@
+# AST_FUNC_FORK
+# -------------
+AN_FUNCTION([fork],  [AST_FUNC_FORK])
+AN_FUNCTION([vfork], [AST_FUNC_FORK])
+AC_DEFUN([AST_FUNC_FORK],
+[AC_REQUIRE([AC_TYPE_PID_T])dnl
+AC_CHECK_HEADERS(vfork.h)
+AC_CHECK_FUNCS(fork vfork)
+if test "x$ac_cv_func_fork" = xyes; then
+  _AST_FUNC_FORK
+else
+  ac_cv_func_fork_works=$ac_cv_func_fork
+fi
+if test "x$ac_cv_func_fork_works" = xcross; then
+  case $host in
+    *-*-amigaos* | *-*-msdosdjgpp* | *-*-uclinux* | *-*-linux-uclibc* )
+      # Override, as these systems have only a dummy fork() stub
+      ac_cv_func_fork_works=no
+      ;;
+    *)
+      ac_cv_func_fork_works=yes
+      ;;
+  esac
+  AC_MSG_WARN([result $ac_cv_func_fork_works guessed because of cross compilation])
+fi
+ac_cv_func_vfork_works=$ac_cv_func_vfork
+if test "x$ac_cv_func_vfork" = xyes; then
+  _AC_FUNC_VFORK
+fi;
+if test "x$ac_cv_func_fork_works" = xcross; then
+  ac_cv_func_vfork_works=$ac_cv_func_vfork
+  AC_MSG_WARN([result $ac_cv_func_vfork_works guessed because of cross compilation])
+fi
+
+if test "x$ac_cv_func_vfork_works" = xyes; then
+  AC_DEFINE(HAVE_WORKING_VFORK, 1, [Define to 1 if `vfork' works.])
+else
+  AC_DEFINE(vfork, fork, [Define as `fork' if `vfork' does not work.])
+fi
+if test "x$ac_cv_func_fork_works" = xyes; then
+  AC_DEFINE(HAVE_WORKING_FORK, 1, [Define to 1 if `fork' works.])
+fi
+])# AST_FUNC_FORK
+
+
+# _AST_FUNC_FORK
+# -------------
+AC_DEFUN([_AST_FUNC_FORK],
+  [AC_CACHE_CHECK(for working fork, ac_cv_func_fork_works,
+    [AC_RUN_IFELSE(
+      [AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT],
+	[
+	  /* By Ruediger Kuhlmann. */
+	  return fork () < 0;
+	])],
+      [ac_cv_func_fork_works=yes],
+      [ac_cv_func_fork_works=no],
+      [ac_cv_func_fork_works=cross])])]
+)# _AST_FUNC_FORK