diff --git a/src/devtools/adb_tcp/adb_trace.h b/src/devtools/adb_tcp/adb_trace.h
new file mode 100644
index 0000000..32c3cc6
--- /dev/null
+++ b/src/devtools/adb_tcp/adb_trace.h
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2014 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 __ADB_TRACE_H
+#define __ADB_TRACE_H
+
+#if !ADB_HOST
+#include <android/log.h>
+#endif
+
+/* define ADB_TRACE to 1 to enable tracing support, or 0 to disable it */
+#define  ADB_TRACE    0
+
+/* IMPORTANT: if you change the following list, don't
+ * forget to update the corresponding 'tags' table in
+ * the adb_trace_init() function implemented in adb.c
+ */
+typedef enum {
+    TRACE_ADB = 0,   /* 0x001 */
+    TRACE_SOCKETS,
+    TRACE_PACKETS,
+    TRACE_TRANSPORT,
+    TRACE_RWX,       /* 0x010 */
+    TRACE_USB,
+    TRACE_SYNC,
+    TRACE_SYSDEPS,
+    TRACE_JDWP,      /* 0x100 */
+    TRACE_SERVICES,
+    TRACE_AUTH,
+    TRACE_FDEVENT,
+} AdbTrace;
+
+#if ADB_TRACE
+
+#if !ADB_HOST
+/*
+ * When running inside the emulator, guest's adbd can connect to 'adb-debug'
+ * qemud service that can display adb trace messages (on condition that emulator
+ * has been started with '-debug adb' option).
+ */
+
+/* Delivers a trace message to the emulator via QEMU pipe. */
+void adb_qemu_trace(const char* fmt, ...);
+/* Macro to use to send ADB trace messages to the emulator. */
+#define DQ(...)    adb_qemu_trace(__VA_ARGS__)
+#else
+#define DQ(...) ((void)0)
+#endif  /* !ADB_HOST */
+
+extern int     adb_trace_mask;
+extern unsigned char    adb_trace_output_count;
+void    adb_trace_init(void);
+
+#  define ADB_TRACING  ((adb_trace_mask & (1 << TRACE_TAG)) != 0)
+
+
+/* you must define TRACE_TAG before using this macro */
+#if ADB_HOST
+#  define  D(...)                                      \
+        do {                                           \
+            if (ADB_TRACING) {                         \
+                int save_errno = errno;                \
+                adb_mutex_lock(&D_lock);               \
+                fprintf(stderr, "%s::%s():",           \
+                        __FILE__, __FUNCTION__);       \
+                errno = save_errno;                    \
+                fprintf(stderr, __VA_ARGS__ );         \
+                fflush(stderr);                        \
+                adb_mutex_unlock(&D_lock);             \
+                errno = save_errno;                    \
+           }                                           \
+        } while (0)
+#  define  DR(...)                                     \
+        do {                                           \
+            if (ADB_TRACING) {                         \
+                int save_errno = errno;                \
+                adb_mutex_lock(&D_lock);               \
+                errno = save_errno;                    \
+                fprintf(stderr, __VA_ARGS__ );         \
+                fflush(stderr);                        \
+                adb_mutex_unlock(&D_lock);             \
+                errno = save_errno;                    \
+           }                                           \
+        } while (0)
+#  define  DD(...)                                     \
+        do {                                           \
+          int save_errno = errno;                      \
+          adb_mutex_lock(&D_lock);                     \
+          fprintf(stderr, "%s::%s():",                 \
+                  __FILE__, __FUNCTION__);             \
+          errno = save_errno;                          \
+          fprintf(stderr, __VA_ARGS__ );               \
+          fflush(stderr);                              \
+          adb_mutex_unlock(&D_lock);                   \
+          errno = save_errno;                          \
+        } while (0)
+#else
+#  define  D(...)                                      \
+        do {                                           \
+            if (ADB_TRACING) {                         \
+                __android_log_print(                   \
+                    ANDROID_LOG_INFO,                  \
+                    __FUNCTION__,                      \
+                    __VA_ARGS__ );                     \
+            }                                          \
+        } while (0)
+#  define  DR(...)                                     \
+        do {                                           \
+            if (ADB_TRACING) {                         \
+                __android_log_print(                   \
+                    ANDROID_LOG_INFO,                  \
+                    __FUNCTION__,                      \
+                    __VA_ARGS__ );                     \
+            }                                          \
+        } while (0)
+#  define  DD(...)                                     \
+        do {                                           \
+          __android_log_print(                         \
+              ANDROID_LOG_INFO,                        \
+              __FUNCTION__,                            \
+              __VA_ARGS__ );                           \
+        } while (0)
+#endif /* ADB_HOST */
+#else
+#  define  D(...)          ((void)0)
+#  define  DR(...)         ((void)0)
+#  define  DD(...)         ((void)0)
+#  define  ADB_TRACING     0
+#endif /* ADB_TRACE */
+
+#endif /* __ADB_TRACE_H */