1 files changed, 29 insertions, 0 deletions
diff --git a/tool/m4/ruby_stack_grow_direction.m4 b/tool/m4/ruby_stack_grow_direction.m4
new file mode 100644
index 0000000000..f8bbc3b6dc
--- /dev/null
+++ b/tool/m4/ruby_stack_grow_direction.m4
@@ -0,0 +1,29 @@
+AC_DEFUN([RUBY_STACK_GROW_DIRECTION], [
+    AS_VAR_PUSHDEF([stack_grow_dir], [rb_cv_stack_grow_dir_$1])
+    AC_CACHE_CHECK(stack growing direction on $1, stack_grow_dir, [
+AS_CASE(["$1"],
+[m68*|x86*|x64|i?86|ia64|ppc*|sparc*|alpha*], [ $2=-1],
+[hppa*], [ $2=+1],
+[
+  AC_TRY_RUN([
+/* recurse to get rid of inlining */
+static int
+stack_growup_p(addr, n)
+    volatile int *addr, n;
+{
+    volatile int end;
+    if (n > 0)
+	return *addr = stack_growup_p(addr, n - 1);
+    else
+	return (&end > addr);
+}
+int main()
+{
+    int x;
+    return stack_growup_p(&x, 10);
+}
+], $2=-1, $2=+1, $2=0)
+  ])
+eval stack_grow_dir=\$$2])
+eval $2=\$stack_grow_dir
+AS_VAR_POPDEF([stack_grow_dir])])dnl