Create new build config for ASAN on Mac OS

Workaround ASAN build issues on Mac OS.
Disable LSAN as it's not supported by the version of clang that ships with Mac OS.

tools/bazel.rc

@@ -13,9 +13,6 @@ build:opt --copt=-Wframe-larger-than=16384
 build:dbg --compilation_mode=dbg
 
 build:asan --strip=never
-# Workaround for https://github.com/bazelbuild/bazel/issues/6932
-build:asan --copt -Wno-macro-redefined
-build:asan --copt -D_FORTIFY_SOURCE=0
 build:asan --copt=-fsanitize=address
 build:asan --copt=-O0
 build:asan --copt=-fno-omit-frame-pointer
@@ -25,6 +22,27 @@ build:asan --linkopt=-fsanitize=address
 build:asan --action_env=ASAN_OPTIONS=detect_leaks=1:color=always
 build:asan --action_env=LSAN_OPTIONS=suppressions=test/core/util/lsan_suppressions.txt:report_objects=1
 
+# We have a separate ASAN config for Mac OS to workaround a couple of bugs:
+# 1. https://github.com/bazelbuild/bazel/issues/6932
+#    _FORTIFY_SOURCE=1 is enabled by default on Mac OS, which breaks ASAN.
+#    We workaround it by setting _FORTIFY_SOURCE=0 and ignoring macro redefined
+#    warnings.
+# 2. https://github.com/google/sanitizers/issues/1026
+#    LSAN is not supported by the version of Clang that ships with Mac OS, so
+#    we disable it.
+build:asan_macos --strip=never
+build:asan_macos --copt=-fsanitize=address
+build:asan_macos --copt -Wno-macro-redefined
+build:asan_macos --copt -D_FORTIFY_SOURCE=0
+build:asan_macos --copt=-fsanitize=address
+build:asan_macos --copt=-O0
+build:asan_macos --copt=-fno-omit-frame-pointer
+build:asan_macos --copt=-DGPR_NO_DIRECT_SYSCALLS
+build:asan_macos --copt=-DADDRESS_SANITIZER  # used by absl
+build:asan_macos --linkopt=-fsanitize=address
+build:asan_macos --action_env=ASAN_OPTIONS=detect_leaks=0
+
+
 build:msan --strip=never
 build:msan --copt=-fsanitize=memory
 build:msan --copt=-O0

tools/internal_ci/macos/grpc_cfstream_asan.cfg

@@ -18,6 +18,6 @@
 build_file: "grpc/tools/internal_ci/macos/grpc_run_bazel_tests.sh"
 env_vars {
   key: "RUN_TESTS_FLAGS"
-  value: "--config=asan"
+  value: "--config=asan_macos"
 }