third_party/mesa: turn off ubsan_vptr, since it's compiled without rtti.

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/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
 # Contains the dependencies needed for sanitizers to link into executables and
 # shared_libraries. Unconditionally depend upon this target as it is empty if
@@ skipping 50 matching lines @@
 
   if (is_lsan) {
     sources += [ "//build/sanitizers/lsan_suppressions.cc" ]
   }
 
   if (is_tsan) {
     sources += [ "//build/sanitizers/tsan_suppressions.cc" ]
   }
 }
 
+config("ubsan_vptr_flags") {
+  if (is_ubsan_vptr) {

[Dirk Pranke, 2016/04/26 01:00:32]

maybe add a comment here about why this isn't just a part of
:default_sanitizer_flags ,  i.e., mention the usage in //third_party/mesa ?

[krasin, 2016/04/26 03:15:09]

Done.

+    ubsan_vptr_blacklist_path =
+        rebase_path("//tools/ubsan/vptr_blacklist.txt", root_build_dir)
+    cflags = [
+      "-fsanitize=vptr",
+      "-fsanitize-blacklist=$ubsan_vptr_blacklist_path",
+    ]
+    ldflags = [ "-fsanitize=vptr" ]
+  }
+}
+
 # Applies linker flags necessary when either :deps or :default_sanitizer_flags
 # are used.
 config("default_sanitizer_ldflags") {
   visibility = [
     ":default_sanitizer_flags",
     ":deps",
   ]
 
   if (is_posix) {
     ldflags = []
     if (is_asan) {
       ldflags += [ "-fsanitize=address" ]
     }
     if (is_lsan) {
       ldflags += [ "-fsanitize=leak" ]
     }
     if (is_tsan) {
       ldflags += [ "-fsanitize=thread" ]
     }
     if (is_msan) {
       ldflags += [ "-fsanitize=memory" ]
     }
     if (is_ubsan || is_ubsan_security) {
       ldflags += [ "-fsanitize=undefined" ]
     }
-    if (is_ubsan_vptr) {
-      ldflags += [ "-fsanitize=vptr" ]
-    }
 
     if (is_cfi && !is_nacl) {
       ldflags += [
         "-fsanitize=cfi-vcall",
         "-fsanitize=cfi-derived-cast",
         "-fsanitize=cfi-unrelated-cast",
       ]
       if (use_cfi_diag) {
         ldflags += [
           "-fno-sanitize-trap=cfi",
@@ skipping 129 matching lines @@
         "-mllvm",
         "-regalloc=pbqp",
 
         # Speculatively use coalescing to slightly improve the code generated
         # by PBQP regallocator. May increase compile time.
         "-mllvm",
         "-pbqp-coalescing",
       ]
     }
   }
-  if (is_ubsan_vptr) {
-    ubsan_vptr_blacklist_path =
-        rebase_path("//tools/ubsan/vptr_blacklist.txt", root_build_dir)
-    cflags += [
-      "-fsanitize=vptr",
-      "-fsanitize-blacklist=$ubsan_vptr_blacklist_path",
-    ]
-  }
   if (is_ubsan_security) {
     ubsan_blacklist_path =
         rebase_path("//tools/ubsan/blacklist.txt", root_build_dir)
     cflags += [
       "-fsanitize=signed-integer-overflow,shift",
       "-fsanitize-blacklist=$ubsan_blacklist_path",
     ]
   }
   if (is_cfi && !is_nacl) {
     cfi_blacklist_path =
@@ skipping 42 matching lines @@
     if (target_cpu == "arm") {
       # http://crbug.com/517105
       cflags += [
         "-mllvm",
         "-sanitizer-coverage-block-threshold=0",
       ]
     }
     defines = [ "SANITIZER_COVERAGE" ]
   }
 }