Warn on missing OVERRIDE/virtual everywhere, not just in header files.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 5d600b0dba1802959c7f03dec810e7d8fcb0cddb..18ea6875a34e3481c91c51d62976f6ea8de3652c 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1427,8 +1427,27 @@
         'grit_defines': ['-D', 'enable_google_now'],
       }],
       ['clang_use_chrome_plugins==1 and OS!="win"', {
-        'clang_chrome_plugins_flags': [
-          '<!@(<(DEPTH)/tools/clang/scripts/plugin_flags.sh)'
+        'variables': {
+          'clang_chrome_plugins_flags': [
+            '<!@(<(DEPTH)/tools/clang/scripts/plugin_flags.sh)'
+          ],
+        },
+        'conditions': [
+          ['OS=="linux" or chromeos==1', {
+            'clang_chrome_plugin_flags': [
+              '<@(clang_chrome_plugin_flags)'
+            ],

[Nico, 2013/02/18 09:42:24]

(do you need this branch at all?)

[Ryan Sleevi, 2013/02/18 09:50:26]

Yeah, this brings it out from variable-variable scope to just variable scope.

GYP is weird, amirite?

[Nico, 2013/02/18 12:07:41]

That's what I guessed.
variable scoping in gyp is a mystery to me. Looking at the 4-deep variable
stacks in build/common.gypi I can't help but feel that I'm not alone. Do you
understand these rules? If so, would you mind writing them up somewhere, with a
simple guideline how deep nesting has to be under which circumstances?

+          }, {
+            # TODO(rsleevi): http://crbug.com/115047 - This warning is only
+            # enabled for Linux/ChromiumOS for now. Disable everywhere else.
+            'clang_chrome_plugin_flags': [
+              '<@(clang_chrome_plugin_flags)',
+              '-Xclang',
+              '-plugin-arg-find-bad-constructs',
+              '-Xclang',
+              'skip-virtuals-in-implementations',
+            ],
+          }]
         ],
       }],