auto import from //depot/cupcake/@135843
diff --git a/include/utils/CallStack.h b/include/utils/CallStack.h
new file mode 100644
index 0000000..c2c8ce5
--- /dev/null
+++ b/include/utils/CallStack.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2007 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 ANDROID_CALLSTACK_H
+#define ANDROID_CALLSTACK_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <utils/String8.h>
+
+// ---------------------------------------------------------------------------
+
+namespace android {
+
+class CallStack
+{
+public:
+ enum {
+ MAX_DEPTH = 31
+ };
+
+ CallStack();
+ CallStack(const CallStack& rhs);
+ ~CallStack();
+
+ CallStack& operator = (const CallStack& rhs);
+
+ bool operator == (const CallStack& rhs) const;
+ bool operator != (const CallStack& rhs) const;
+ bool operator < (const CallStack& rhs) const;
+ bool operator >= (const CallStack& rhs) const;
+ bool operator > (const CallStack& rhs) const;
+ bool operator <= (const CallStack& rhs) const;
+
+ const void* operator [] (int index) const;
+
+ void clear();
+
+ void update(int32_t ignoreDepth=0, int32_t maxDepth=MAX_DEPTH);
+
+ // Dump a stack trace to the log
+ void dump(const char* prefix = 0) const;
+
+ // Return a string (possibly very long) containing the complete stack trace
+ String8 toString(const char* prefix = 0) const;
+
+ size_t size() const { return mCount; }
+
+private:
+ // Internal helper function
+ String8 toStringSingleLevel(const char* prefix, int32_t level) const;
+
+ size_t mCount;
+ const void* mStack[MAX_DEPTH];
+};
+
+}; // namespace android
+
+
+// ---------------------------------------------------------------------------
+
+#endif // ANDROID_CALLSTACK_H