--- /dev/null
+#
+# Copyright (C) 2016 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Most Android source files are not clang-tidy clean yet.
+# Global tidy checks include only google* minus google-readability*.
+DEFAULT_GLOBAL_TIDY_CHECKS := \
+ -*,google*,-google-readability*
+
+# Disable google style rules usually not followed by external projects.
+# Every word in DEFAULT_LOCAL_TIDY_CHECKS list has the following format:
+# <local_path_prefix>:,<tidy-check-pattern>
+# The tidy-check-patterns of all matching local_path_prefixes will be used.
+# For example, external/google* projects will have:
+# ,-google-build-using-namespace,-google-explicit-constructor
+# ,-google-runtime-int,google-runtime-int
+# where google-runtime-int is enabled at the end.
+DEFAULT_LOCAL_TIDY_CHECKS := \
+ external/:,-google-build-using-namespace \
+ external/:,-google-explicit-constructor \
+ external/:,-google-runtime-int \
+ external/google:,google-runtime-int \
+ external/webrtc/:,google-runtime-int \
+
+# Returns 2nd word of $(1) if $(2) has prefix of the 1st word of $(1).
+define find_default_local_tidy_check2
+$(if $(filter $(word 1,$(1))%,$(2)/),$(word 2,$(1)))
+endef
+
+# Returns 2nd part of $(1) if $(2) has prefix of the 1st part of $(1).
+define find_default_local_tidy_check
+$(call find_default_local_tidy_check2,$(subst :,$(space),$(1)),$(2))
+endef
+
+# Returns concatenated tidy check patterns from the
+# DEFAULT_GLOBAL_TIDY_CHECKS and all matched patterns
+# in DEFAULT_LOCAL_TIDY_CHECKS based on given directory path $(1).
+define default_global_tidy_checks
+$(subst $(space),, \
+ $(DEFAULT_GLOBAL_TIDY_CHECKS) \
+ $(foreach pattern,$(DEFAULT_LOCAL_TIDY_CHECKS), \
+ $(call find_default_local_tidy_check,$(pattern),$(1)) \
+ ) \
+)
+endef