UBSAN fixes.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 3bcc41627f9d7f9d25fb0ecb481d140c7ce08d4e..4f7d6686ffee2b48f5dcc62686fbf1e207e144a4 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -431,11 +431,11 @@
       # -fsanitize=undefined only works with clang, but ubsan=1 implies clang=1
       # See http://clang.llvm.org/docs/UsersManual.html
       'ubsan%': 0,
+      'ubsan_blacklist%': '<(PRODUCT_DIR)/../../tools/ubsan/blacklist.txt',
 
       # Enable building with UBsan's vptr (Clang's -fsanitize=vptr option).
       # -fsanitize=vptr only works with clang, but ubsan_vptr=1 implies clang=1
       'ubsan_vptr%': 0,
-      'ubsan_vptr_blacklist%': '<(PRODUCT_DIR)/../../tools/ubsan_vptr/blacklist.txt',
 
       # Use the dynamic libraries instrumented by one of the sanitizers
       # instead of the standard system libraries.
@@ -1130,8 +1130,8 @@
     'tsan%': '<(tsan)',
     'tsan_blacklist%': '<(tsan_blacklist)',
     'ubsan%': '<(ubsan)',
+    'ubsan_blacklist%': '<(ubsan_blacklist)',
     'ubsan_vptr%': '<(ubsan_vptr)',
-    'ubsan_vptr_blacklist%': '<(ubsan_vptr_blacklist)',
     'use_instrumented_libraries%': '<(use_instrumented_libraries)',
     'use_custom_libcxx%': '<(use_custom_libcxx)',
     'use_system_libcxx%': '<(use_system_libcxx)',
@@ -4209,8 +4209,7 @@
               ['_toolset=="target"', {
                 'cflags': [
                   '-fsanitize=undefined',
-                  # -fsanitize=vptr is incompatible with -fno-rtti.
-                  '-fno-sanitize=vptr',
+                  '-fsanitize-blacklist=<(ubsan_blacklist)',
                   # Employ the experimental PBQP register allocator to avoid
                   # slow compilation on files with too many basic blocks.
                   # See http://crbug.com/426271.
@@ -4219,10 +4218,17 @@
                   # generated by PBQP regallocator. May increase compile time.
                   '-mllvm -pbqp-coalescing',
                 ],
+                'cflags_cc!': [
+                  '-fno-rtti',
+                ],
+                'cflags!': [
+                  '-fno-rtti',
+                ],
                 'ldflags': [
                   '-fsanitize=undefined',
-                  # -fsanitize=vptr is incompatible with -fno-rtti.
-                  '-fno-sanitize=vptr',
+                ],
+                'defines': [
+                  'UNDEFINED_SANITIZER',
                 ],
               }],
             ],
@@ -4232,7 +4238,7 @@
               ['_toolset=="target"', {
                 'cflags': [
                   '-fsanitize=vptr',
-                  '-fsanitize-blacklist=<(ubsan_vptr_blacklist)',
+                  '-fsanitize-blacklist=<(ubsan_blacklist)',
                 ],
                 'cflags_cc!': [
                   '-fno-rtti',