GN build: Prescribe -Wno-header-guard for direct dependents of libssl.

net/third_party/nss/ssl/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 config("ssl_config") {
   include_dirs = [ "." ]
 
   if (is_mac || is_win) {
     defines = [ "NSS_PLATFORM_CLIENT_AUTH" ]
   }
+
+  if (is_clang) {
+    cflags = [
+      # There is a broken header guard in /usr/include/nss/secmod.h:
+      # https://bugzilla.mozilla.org/show_bug.cgi?id=884072
+      "-Wno-header-guard",
+    ]
+  }
 }
 
 component("libssl") {
   output_name = "crssl"
 
   sources = [
     "authcert.c",
     "cmpcert.c",
     "derive.c",
     "dtlscon.c",
@@ skipping 97 matching lines @@
       "//third_party/nss:nspr",
       "//third_party/nss:nss",
     ]
     forward_dependent_configs_from = deps
   }
 
   if (is_clang) {
     cflags += [
       # See http://crbug.com/138571#c8. In short, sslsecur.c picks up the
       # system's cert.h because cert.h isn't in chromium's repo.
       "-Wno-incompatible-pointer-types",

[wtc, 2014/09/29 17:50:01]

This NSS bug was fixed in NSS 3.12.10. Chromium requires NSS 3.14.3 or later
now. So please don't copy this to the new config("ssl_config") section above.

If you have time, please remove this flag from this file and from
net/third_party/nss/ssl.gyp. If you don't want to complicate this CL, I will
take care of this.

[engedy, 2014/09/29 18:59:10]

Hmm, in my read, all signs point to that it was only fixed in 3.15.1, what I am
missing?

More specifically, according to [1], 3.12.10 still seems to contain the typo,
[2] says that the fix was slated for 3.15.1, and we are indeed using 3.14.5 for
Chrome branded builds (see [3,4]), and the compile error is still present.

[1]: https://bugzilla.mozilla.org/show_bug.cgi?id=884072
[2]:
http://anonscm.debian.org/cgit/pkg-mozilla/nss.git/tree/mozilla/security/nss/...
[3]:
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/installer/l...
[4]: https://packages.debian.org/source/wheezy/nss

[wtc, 2014/09/29 19:43:38]

I was talking about the -Wno-incompatible-pointer-types flag, which is not part
of your CL. The NSS bug that -Wno-incompatible-pointer-types works around is
https://bugzilla.mozilla.org/show_bug.cgi?id=635778 , which is fixed in NSS
3.12.10.

Sorry about the confusion.

[engedy, 2014/09/30 18:15:29]

Ahh, my bad, sorry! I have prepared https://codereview.chromium.org/616093002/
to fix this.

 
       # There is a broken header guard in /usr/include/nss/secmod.h:
       # https://bugzilla.mozilla.org/show_bug.cgi?id=884072
       "-Wno-header-guard",

[wtc, 2014/09/29 17:35:45]

The -Wno-header-guard flag is already added here. Please find out why it isn't
working.

[brettw, 2014/09/29 17:42:28]

We should delete this one. The one above will also apply to direct dependents in
addition to this target, so covers more stuff.

[engedy, 2014/09/30 18:15:29]

Done.

     ]
   }
 
   if (is_debug) {
     defines += [ "DEBUG" ]
   }
 }