1 files changed, 60 insertions, 0 deletions
diff --git a/security/nss/coreconf/werror.py b/security/nss/coreconf/werror.py
new file mode 100644
index 0000000000..0e2d41c63c
--- /dev/null
+++ b/security/nss/coreconf/werror.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python
+
+import os
+import subprocess
+
+def main():
+    cc = os.environ.get('CC', 'cc')
+    sink = open(os.devnull, 'wb')
+    try:
+        cc_is_clang = 'clang' in subprocess.check_output(
+          [cc, '--version'], universal_newlines=True, stderr=sink)
+    except OSError:
+        # We probably just don't have CC/cc.
+        return
+
+    def warning_supported(warning):
+        return subprocess.call([cc, '-x', 'c', '-E', '-Werror',
+                                '-W%s' % warning, os.devnull], stdout=sink, stderr=sink) == 0
+    def can_enable():
+        # This would be a problem
+        if not warning_supported('all'):
+            return False
+
+        # If we aren't clang, make sure we have gcc 4.8 at least
+        if not cc_is_clang:
+            try:
+                v = subprocess.check_output([cc, '-dumpversion'], stderr=sink).decode("utf-8")
+                v = v.strip(' \r\n').split('.')
+                v = list(map(int, v))
+                if v[0] < 4 or (v[0] == 4 and v[1] < 8):
+                    # gcc 4.8 minimum
+                    return False
+            except OSError:
+                return False
+        return True
+
+    if not can_enable():
+        print('-DNSS_NO_GCC48')
+        return
+
+    print('-Werror')
+    print('-Wall')
+
+    def set_warning(warning, contra=''):
+        if warning_supported(warning):
+            print('-W%s%s' % (contra, warning))
+
+    if cc_is_clang:
+        # clang is unable to handle glib's expansion of strcmp and similar for
+        # optimized builds, so disable the resulting errors.
+        # See https://llvm.org/bugs/show_bug.cgi?id=20144
+        for w in ['array-bounds', 'unevaluated-expression',
+                  'parentheses-equality']:
+            set_warning(w, 'no-')
+        print('-Qunused-arguments')
+
+    set_warning('shadow')
+
+if __name__ == '__main__':
+    main()