assert-h: new module, which supports C1X-style static_assert

[gnulib.git] / m4 / assert_h.m4

diff --git a/m4/assert_h.m4 b/m4/assert_h.m4
new file mode 100644 (file)
index 0000000..30ca248
--- /dev/null
+++ b/m4/assert_h.m4
@@ -0,0 +1,29 @@
+# assert-h.m4
+dnl Copyright (C) 2011 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.
+
+dnl From Paul Eggert.
+
+AC_DEFUN([gl_ASSERT_H],
+[
+  ASSERT_H=
+  AC_CACHE_CHECK([for static_assert], [gl_cv_static_assert],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <assert.h>
+            static_assert (2 + 2 == 4, "arithmetic doesn't work");
+          ]],
+          [[
+            static_assert (sizeof (char) == 1, "sizeof doesn't work");
+          ]])],
+       [gl_cv_static_assert=yes],
+       [gl_cv_static_assert=no])])
+  if test $gl_cv_static_assert = no; then
+    ASSERT_H=assert.h
+    gl_NEXT_HEADERS([assert.h])
+  fi
+  AC_SUBST([ASSERT_H])
+  AM_CONDITIONAL([GL_GENERATE_ASSERT_H], [test -n "$ASSERT_H"])
+])