GN: ccache+clang needs -Qunused-arguments

An alternative is to define CCACHE_CPP2, but
I thought I'd try this more visible way first.

(CCACHE_CPP2 may turn out to be required anyway
if we start seeing warnings about tautological compares.)

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2193203002

TBR=jcgregorio@google.com
NOTRY=true

Review-Url: https://codereview.chromium.org/2193203002

diff --git a/infra/bots/recipe_modules/skia/gn_flavor.py b/infra/bots/recipe_modules/skia/gn_flavor.py
index c4988fb..7b60b9a 100644 (file)
--- a/infra/bots/recipe_modules/skia/gn_flavor.py
+++ b/infra/bots/recipe_modules/skia/gn_flavor.py
@@ -18,15 +18,22 @@ class GNFlavorUtils(default_flavor.DefaultFlavorUtils):
         is_debug = 'is_debug=false'
     gn_args = [is_debug]
 
+    is_clang = 'Clang' in self._skia_api.builder_name
+    is_gcc   = 'GCC'   in self._skia_api.builder_name
+
     cc, cxx = 'cc', 'c++'
-    if 'Clang' in self._skia_api.builder_name:
+    if is_clang:
       cc, cxx = 'clang', 'clang++'
-    elif 'GCC' in self._skia_api.builder_name:
+    elif is_gcc:
       cc, cxx = 'gcc', 'g++'
 
     ccache = self._skia_api.ccache()
     if ccache:
       cc, cxx = '%s %s' % (ccache, cc), '%s %s' % (ccache, cxx)
+      if is_clang:
+        # Stifle "argument unused during compilation: ..." warnings.
+        stifle = '-Qunused-arguments'
+        cc, cxx = '%s %s' % (cc, stifle), '%s %s' % (cxx, stifle)
 
     gn_args += [ 'cc="%s"' % cc, 'cxx="%s"' % cxx ]
 

diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json
index 91ca8c0..1658b3b 100644 (file)
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json
@@ -164,7 +164,7 @@
       "gn",
       "gen",
       "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-Clang-x86_64-Debug-GN/Debug",
-      "--args=is_debug=true cc=\"/usr/bin/ccache clang\" cxx=\"/usr/bin/ccache clang++\""
+      "--args=is_debug=true cc=\"/usr/bin/ccache clang -Qunused-arguments\" cxx=\"/usr/bin/ccache clang++ -Qunused-arguments\""
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
     "env": {