Extend header-abi-dumper/linker --root-dir

This commit extends the format of --root-dir to <path>:<replacement>. If
a source path starts with <path>, the prefix is replaced. The build
system can use this option to have the ABI tools replace non-default
OUT_DIR with "out". This commit also allows more than one --root-dir.
When the tool normalizes a source path, the tool finds the longest
matching root dir.

Test: ./header-checker-unittests
Bug: 192157880
Change-Id: Ie77b4f09304e029aa5c2acc6a000c59400913426

vndk/tools/header-checker/src/utils/source_path_utils.h

@@ -0,0 +1,52 @@
+// Copyright (C) 2021 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.
+
+#ifndef SOURCE_PATH_UTILS_H_
+#define SOURCE_PATH_UTILS_H_
+
+#include <set>
+#include <string>
+#include <vector>
+
+
+namespace header_checker {
+namespace utils {
+
+
+struct RootDir {
+  std::string path;
+  std::string replacement;
+
+  RootDir(std::string p, std::string r)
+      : path(std::move(p)), replacement(std::move(r)) {}
+};
+
+typedef std::vector<RootDir> RootDirs;
+
+RootDirs ParseRootDirs(const std::vector<std::string> &args);
+
+// Resolve '..' and '.'; if the path starts with any of root_dirs, replace the
+// prefix; don't resolve symbolic links.
+std::string NormalizePath(std::string_view path, const RootDirs &root_dirs);
+
+std::set<std::string>
+CollectAllExportedHeaders(const std::vector<std::string> &exported_header_dirs,
+                          const RootDirs &root_dirs);
+
+
+}  // namespace utils
+}  // namespace header_checker
+
+
+#endif  // SOURCE_PATH_UTILS_H_