2 files changed, 105 insertions, 0 deletions
diff --git a/core/java/android/os/Debug.java b/core/java/android/os/Debug.java
index 20a731e..98fe06a 100644
--- a/core/java/android/os/Debug.java
+++ b/core/java/android/os/Debug.java
@@ -1324,4 +1324,42 @@ href="{@docRoot}guide/developing/tools/traceview.html">Traceview: A Graphical Lo
             return false;
         }
     }
+
+    /**
+     * Return a String describing the calling method and location at a particular stack depth.
+     * @param callStack the Thread stack 
+     * @param depth the depth of stack to return information for.
+     * @return the String describing the caller at that depth.
+     */
+    private static String getCaller(StackTraceElement callStack[], int depth) {
+        // callStack[4] is the caller of the method that called getCallers()
+        if (4 + depth >= callStack.length) {
+            return "<bottom of call stack>";
+        }
+        StackTraceElement caller = callStack[4 + depth];
+        return caller.getClassName() + "." + caller.getMethodName() + ":" + caller.getLineNumber();
+    }
+
+    /**
+     * Return a string consisting of methods and locations at multiple call stack levels.
+     * @param depth the number of levels to return, starting with the immediate caller.
+     * @return a string describing the call stack.
+     * {@hide}
+     */
+    public static String getCallers(final int depth) {
+        final StackTraceElement[] callStack = Thread.currentThread().getStackTrace();
+        StringBuffer sb = new StringBuffer();
+        for (int i = 0; i < depth; i++) {
+            sb.append(getCaller(callStack, i)).append(" ");
+        }
+        return sb.toString();
+    }
+
+    /**
+     * @return a String describing the immediate caller of the calling function.
+     * {@hide}
+     */
+    public static String getCaller() {
+        return getCaller(Thread.currentThread().getStackTrace(), 0);
+    }
 }
diff --git a/core/tests/coretests/src/com/android/internal/os/DebugTest.java b/core/tests/coretests/src/com/android/internal/os/DebugTest.java
new file mode 100644
index 0000000..88c7d1b
--- /dev/null
+++ b/core/tests/coretests/src/com/android/internal/os/DebugTest.java
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2012 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.
+ */
+
+package com.android.internal.os;
+
+import android.os.Debug;
+
+import android.test.suitebuilder.annotation.SmallTest;
+import junit.framework.TestCase;
+
+@SmallTest
+public class DebugTest extends TestCase {
+
+    private final static String EXPECTED_GET_CALLER =
+            "com\\.android\\.internal\\.os\\.DebugTest\\.testGetCaller:\\d\\d";
+    private final static String EXPECTED_GET_CALLERS =
+            "com\\.android\\.internal\\.os\\.DebugTest.callDepth3:\\d\\d " +
+            "com\\.android\\.internal\\.os\\.DebugTest.callDepth2:\\d\\d " +
+            "com\\.android\\.internal\\.os\\.DebugTest.callDepth1:\\d\\d ";
+
+    /**
+     * @return String consisting of the caller to this method.
+     */
+    private String callDepth0() {
+        return Debug.getCaller();
+    }
+
+    public void testGetCaller() {
+        assertTrue(callDepth0().matches(EXPECTED_GET_CALLER));
+    }
+
+    /**
+     * @return String consisting of the callers to this method.
+     */
+    private String callDepth4() {
+        return Debug.getCallers(3);
+    }
+
+    private String callDepth3() {
+        return callDepth4();
+    }
+
+    private String callDepth2() {
+        return callDepth3();
+    }
+
+    private String callDepth1() {
+        return callDepth2();
+    }
+
+    public void testGetCallers() {
+        assertTrue(callDepth1().matches(EXPECTED_GET_CALLERS));
+    }
+}