Add clang-tidy.sh to filter out troublesome flags.

* Some flags are accepted by clang but not clang-tidy.
  They could cause the diagnostic-unused-command-line-argument warning.
  Flag -flto messed up the -I flags.
* Add clang-diagnostic-unused-command-line-argument to
  default clang-tidy checks.
* Move CLANG_TIDY_UNKNOWN_CFLAGS to build/make/core/clang/tidy.mk.

Bug: 111850071
Bug: 111885396
Test: build with WITH_TIDY=1
Change-Id: Iabeeb27715acf83ef6aafe3e77206b9a01a0d889

1 files changed, 37 insertions, 0 deletions

diff --git a/scripts/clang-tidy.sh b/scripts/clang-tidy.sh
new file mode 100755
index 00000000..04d0bdd9
--- /dev/null
+++ b/scripts/clang-tidy.sh
@@ -0,0 +1,37 @@
+#!/bin/bash -e
+
+# Copyright 2018 Google Inc. All rights reserved.
+#
+# 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.
+
+# Wrapper script to remove clang compiler flags rejected by clang-tidy.
+# Inputs:
+#  Environment:
+#   CLANG_TIDY: path to the real clang-tidy program
+
+# clang-tidy doesn't recognize every flag that clang compiler does.
+# It gives clang-diagnostic-unused-command-line-argument warnings
+# to -Wa,* flags.
+# The -flto flags caused clang-tidy to ignore the -I flags,
+# see https://bugs.llvm.org/show_bug.cgi?id=38332.
+# -fsanitize and -fwhole-program-vtables need -flto.
+args=("${@}")
+n=${#args[@]}
+for ((i=0; i<$n; ++i)); do
+  case ${args[i]} in
+    -Wa,*|-flto|-flto=*|-fsanitize=*|-fsanitize-*|-fwhole-program-vtables)
+      unset args[i]
+      ;;
+  esac
+done
+${CLANG_TIDY} "${args[@]}"