Bug 1182667 - Enable warnings as errors, r=rrelyea

1 files changed, 40 insertions, 0 deletions

diff --git a/lib/util/verref.h b/lib/util/verref.h
new file mode 100644
index 000000000..2d141bb5c
--- /dev/null
+++ b/lib/util/verref.h
@@ -0,0 +1,40 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* This header is used inline in a function to ensure that a version string
+ * symbol is linked in and not optimized out. A volatile reference is added to
+ * the variable identified by NSS_VERSION_VARIABLE.
+ *
+ * Use this as follows:
+ *
+ * #define NSS_VERSION_VARIABLE __nss_ssl_version
+ * #include "verref.h"
+ */
+
+/* Suppress unused variable warnings. */
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable: 4101)
+#endif
+/* This works for both gcc and clang */
+#if defined(__GNUC__) && !defined(NSS_NO_GCC48)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-variable"
+#endif
+
+#ifndef NSS_VERSION_VARIABLE
+#error NSS_VERSION_VARIABLE must be set before including "verref.h"
+#endif
+{
+    extern const char NSS_VERSION_VARIABLE[];
+    volatile const char _nss_version_c = NSS_VERSION_VARIABLE[0];
+}
+#undef NSS_VERSION_VARIABLE
+
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+#if defined(__GNUC__) && !defined(NSS_NO_GCC48)
+#pragma GCC diagnostic pop
+#endif