Add minimal LLVM sanity coverage (sancov) reporting for unittests.

webrtc/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 # TODO(kjellander): Rebase this to webrtc/build/common.gypi changes after r6330.
 
 import("//build/config/linux/pkg_config.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("build/webrtc.gni")
 import("//testing/test.gni")
 import("//third_party/protobuf/proto_library.gni")
 
 # Contains the defines and includes in common.gypi that are duplicated both as
 # target_defaults and direct_dependent_settings.
 config("common_inherited_config") {
   defines = []
+  cflags = []
+  ldflags = []
   if (build_with_mozilla) {
     defines += [ "WEBRTC_MOZILLA_BUILD" ]
   }
   if (build_with_chromium) {
     defines = [
       # TODO(kjellander): Cleanup unused ones and move defines closer to
       # the source when webrtc:4256 is completed.
       "FEATURE_ENABLE_SSL",
       "FEATURE_ENABLE_VOICEMAIL",
       "EXPAT_RELATIVE_PATH",
@@ skipping 39 matching lines @@
   if (is_android) {
     defines += [
       "WEBRTC_LINUX",
       "WEBRTC_ANDROID",
     ]
   }
   if (is_chromeos) {
     defines += [ "CHROMEOS" ]
   }
 
+  if (rtc_sanitize_coverage != "") {
+    assert(is_clang, "sanitizer coverage requires clang")
+    cflags += [ "-fsanitize-coverage=${rtc_sanitize_coverage}" ]
+    ldflags += [ "-fsanitize-coverage=${rtc_sanitize_coverage}" ]
+  }
+
   # TODO(GYP): Support these in GN.
   # if (is_bsd) {
   #   defines += [ "BSD" ]
   # }
   # if (is_openbsd) {
   #   defines += [ "OPENBSD" ]
   # }
   # if (is_freebsd) {
   #   defines += [ "FREEBSD" ]
   # }
@@ skipping 564 matching lines @@
     if (is_ios || (is_mac && target_cpu != "x86")) {
       defines = [ "CARBON_DEPRECATED=YES" ]
     }
     if (is_clang) {
       # Suppress warnings from the Chromium Clang plugin.
       # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
       configs -= [ "//build/config/clang:find_bad_constructs" ]
     }
   }
 }