Set using_sanitizer if use_cfi_diag is true.

build/config/sanitizers/BUILD.gn

 # Copyright 2014 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.
 
 import("//build_overrides/build.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/clang/clang.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/toolchain/toolchain.gni")
@@ skipping 254 matching lines @@
 
     cflags += [
       # Column info in debug data confuses Visual Studio's debugger, so don't
       # use this by default.  However, clusterfuzz needs it for good attribution
       # of reports to CLs, so turn it on there.
       "-gcolumn-info",
     ]
   }
 
   # Common options for AddressSanitizer, LeakSanitizer, ThreadSanitizer,
-  # MemorySanitizer and non-official CFI builds.
-  if (using_sanitizer || (is_cfi && !is_official_build)) {
+  # MemorySanitizer and CFI with diagnostics.
+  if (using_sanitizer) {
     if (is_posix) {
       cflags += [ "-fno-omit-frame-pointer" ]

[Nico, 2017/06/19 19:29:41]

This still doesn't happen in prod builds, right? Can you maybe add a
assert(!is_official_build) here?

[pcc1, 2017/06/19 22:18:52]

That would essentially forbid sanitizers in official builds, right? Is that a
good idea?

[Nico, 2017/06/19 23:50:28]

I think so?  Not sure, but with this change it seems easier to accidentally ship
a sanitizer build to prod, and generally we don't want to do this, right?

When we ship asan binaries to canary, I'd expect that that would just set
is_chrome_branded but not is_official_build, else we grow yet another build
config to maintain.

[pcc1, 2017/06/19 23:59:08]

Seems reasonable enough. I was imagining that people might want to use a
sanitizer to debug something in an official build, but the tradeoff seems to be
in favour of hacking the build config locally in those cases.

     } else {
       cflags += [ "/Oy-" ]
     }
   }
 }
 
 # TODO(thomasanderson): Move this out of build/config/sanitizers.
 config("libcxx_flags") {
   if (use_custom_libcxx) {
     prefix = "//buildtools/third_party"
@@ skipping 283 matching lines @@
 # This allows to selectively disable ubsan_vptr, when needed. In particular,
 # if some third_party code is required to be compiled without rtti, which
 # is a requirement for ubsan_vptr.
 config("default_sanitizer_flags_but_ubsan_vptr") {
   configs = all_sanitizer_configs - [ ":ubsan_vptr_flags" ]
 }
 
 config("default_sanitizer_flags_but_coverage") {
   configs = all_sanitizer_configs - [ ":coverage_flags" ]
 }