[veridex] Log when linking against private APIs.

Change-Id: Ib1f255f74ed8803fcf240c6d296f0b8813bb8554
diff --git a/tools/veridex/hidden_api.cc b/tools/veridex/hidden_api.cc
new file mode 100644
index 0000000..33e499b
--- /dev/null
+++ b/tools/veridex/hidden_api.cc
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#include "hidden_api.h"
+
+#include <fstream>
+#include <sstream>
+
+#include "dex/dex_file-inl.h"
+
+namespace art {
+
+std::string HiddenApi::GetApiMethodName(const DexFile& dex_file, uint32_t method_index) {
+  std::stringstream ss;
+  const DexFile::MethodId& method_id = dex_file.GetMethodId(method_index);
+  ss << dex_file.StringByTypeIdx(method_id.class_idx_)
+     << "->"
+     << dex_file.GetMethodName(method_id)
+     << dex_file.GetMethodSignature(method_id).ToString();
+  return ss.str();
+}
+
+std::string HiddenApi::GetApiFieldName(const DexFile& dex_file, uint32_t field_index) {
+  std::stringstream ss;
+  const DexFile::FieldId& field_id = dex_file.GetFieldId(field_index);
+  ss << dex_file.StringByTypeIdx(field_id.class_idx_)
+     << "->"
+     << dex_file.GetFieldName(field_id)
+     << ":"
+     << dex_file.GetFieldTypeDescriptor(field_id);
+  return ss.str();
+}
+
+bool HiddenApi::LogIfIn(const std::string& name,
+                        const std::set<std::string>& list,
+                        const std::string& log,
+                        const std::string& access_kind) {
+  if (list.find(name) != list.end()) {
+    LOG(WARNING) << std::string(log) << " usage found " << name << " (" << access_kind << ")";
+    return true;
+  }
+  return false;
+}
+
+void HiddenApi::FillList(const char* filename, std::set<std::string>& entries) {
+  if (filename == nullptr) {
+    return;
+  }
+  std::ifstream in(filename);
+  std::string str;
+  while (std::getline(in, str)) {
+    entries.insert(str);
+    size_t pos = str.find("->");
+    if (pos != std::string::npos) {
+      // Add the class name.
+      entries.insert(str.substr(0, pos));
+      pos = str.find('(');
+      if (pos != std::string::npos) {
+        // Add the class->method name (so stripping the signature).
+        entries.insert(str.substr(0, pos));
+      }
+    }
+  }
+}
+
+}  // namespace art