diff --git a/liblog/include/log/log.h b/liblog/include/log/log.h
index 6a7450c..36c1e68 100644
--- a/liblog/include/log/log.h
+++ b/liblog/include/log/log.h
@@ -31,6 +31,7 @@
 #include <log/log_id.h>
 #include <log/log_main.h>
 #include <log/log_radio.h>
+#include <log/log_system.h>
 #include <log/uio.h> /* helper to define iovec for portability */
 
 #ifdef __cplusplus
@@ -76,90 +77,6 @@
 #pragma clang diagnostic ignored "-Wgnu-zero-variadic-macro-arguments"
 #endif
 
-/*
- * Simplified macro to send a verbose system log message using current LOG_TAG.
- */
-#ifndef SLOGV
-#define __SLOGV(...) \
-    ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_VERBOSE, LOG_TAG, __VA_ARGS__))
-#if LOG_NDEBUG
-#define SLOGV(...) do { if (0) { __SLOGV(__VA_ARGS__); } } while (0)
-#else
-#define SLOGV(...) __SLOGV(__VA_ARGS__)
-#endif
-#endif
-
-#ifndef SLOGV_IF
-#if LOG_NDEBUG
-#define SLOGV_IF(cond, ...)   ((void)0)
-#else
-#define SLOGV_IF(cond, ...) \
-    ( (__predict_false(cond)) \
-    ? ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_VERBOSE, LOG_TAG, __VA_ARGS__)) \
-    : (void)0 )
-#endif
-#endif
-
-/*
- * Simplified macro to send a debug system log message using current LOG_TAG.
- */
-#ifndef SLOGD
-#define SLOGD(...) \
-    ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__))
-#endif
-
-#ifndef SLOGD_IF
-#define SLOGD_IF(cond, ...) \
-    ( (__predict_false(cond)) \
-    ? ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__)) \
-    : (void)0 )
-#endif
-
-/*
- * Simplified macro to send an info system log message using current LOG_TAG.
- */
-#ifndef SLOGI
-#define SLOGI(...) \
-    ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__))
-#endif
-
-#ifndef SLOGI_IF
-#define SLOGI_IF(cond, ...) \
-    ( (__predict_false(cond)) \
-    ? ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)) \
-    : (void)0 )
-#endif
-
-/*
- * Simplified macro to send a warning system log message using current LOG_TAG.
- */
-#ifndef SLOGW
-#define SLOGW(...) \
-    ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__))
-#endif
-
-#ifndef SLOGW_IF
-#define SLOGW_IF(cond, ...) \
-    ( (__predict_false(cond)) \
-    ? ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__)) \
-    : (void)0 )
-#endif
-
-/*
- * Simplified macro to send an error system log message using current LOG_TAG.
- */
-#ifndef SLOGE
-#define SLOGE(...) \
-    ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__))
-#endif
-
-#ifndef SLOGE_IF
-#define SLOGE_IF(cond, ...) \
-    ( (__predict_false(cond)) \
-    ? ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)) \
-    : (void)0 )
-#endif
-
 /* --------------------------------------------------------------------- */
 
 /*
diff --git a/liblog/include/log/log_system.h b/liblog/include/log/log_system.h
new file mode 100644
index 0000000..8c1ec96
--- /dev/null
+++ b/liblog/include/log/log_system.h
@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2005-2017 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 _LIBS_LOG_LOG_SYSTEM_H
+#define _LIBS_LOG_LOG_SYSTEM_H
+
+#include <android/log.h>
+#include <log/log_id.h>
+
+/*
+ * Normally we strip the effects of ALOGV (VERBOSE messages),
+ * LOG_FATAL and LOG_FATAL_IF (FATAL assert messages) from the
+ * release builds be defining NDEBUG.  You can modify this (for
+ * example with "#define LOG_NDEBUG 0" at the top of your source
+ * file) to change that behavior.
+ */
+
+#ifndef LOG_NDEBUG
+#ifdef NDEBUG
+#define LOG_NDEBUG 1
+#else
+#define LOG_NDEBUG 0
+#endif
+#endif
+
+/*
+ * Simplified macro to send a verbose system log message using current LOG_TAG.
+ */
+#ifndef SLOGV
+#define __SLOGV(...) \
+    ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_VERBOSE, LOG_TAG, __VA_ARGS__))
+#if LOG_NDEBUG
+#define SLOGV(...) do { if (0) { __SLOGV(__VA_ARGS__); } } while (0)
+#else
+#define SLOGV(...) __SLOGV(__VA_ARGS__)
+#endif
+#endif
+
+#ifndef SLOGV_IF
+#if LOG_NDEBUG
+#define SLOGV_IF(cond, ...)   ((void)0)
+#else
+#define SLOGV_IF(cond, ...) \
+    ( (__predict_false(cond)) \
+    ? ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_VERBOSE, LOG_TAG, __VA_ARGS__)) \
+    : (void)0 )
+#endif
+#endif
+
+/*
+ * Simplified macro to send a debug system log message using current LOG_TAG.
+ */
+#ifndef SLOGD
+#define SLOGD(...) \
+    ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__))
+#endif
+
+#ifndef SLOGD_IF
+#define SLOGD_IF(cond, ...) \
+    ( (__predict_false(cond)) \
+    ? ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__)) \
+    : (void)0 )
+#endif
+
+/*
+ * Simplified macro to send an info system log message using current LOG_TAG.
+ */
+#ifndef SLOGI
+#define SLOGI(...) \
+    ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__))
+#endif
+
+#ifndef SLOGI_IF
+#define SLOGI_IF(cond, ...) \
+    ( (__predict_false(cond)) \
+    ? ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)) \
+    : (void)0 )
+#endif
+
+/*
+ * Simplified macro to send a warning system log message using current LOG_TAG.
+ */
+#ifndef SLOGW
+#define SLOGW(...) \
+    ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__))
+#endif
+
+#ifndef SLOGW_IF
+#define SLOGW_IF(cond, ...) \
+    ( (__predict_false(cond)) \
+    ? ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__)) \
+    : (void)0 )
+#endif
+
+/*
+ * Simplified macro to send an error system log message using current LOG_TAG.
+ */
+#ifndef SLOGE
+#define SLOGE(...) \
+    ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__))
+#endif
+
+#ifndef SLOGE_IF
+#define SLOGE_IF(cond, ...) \
+    ( (__predict_false(cond)) \
+    ? ((void)__android_log_buf_print(LOG_ID_SYSTEM, ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)) \
+    : (void)0 )
+#endif
+
+#endif /* _LIBS_LOG_LOG_SYSTEM_H */
diff --git a/liblog/tests/Android.mk b/liblog/tests/Android.mk
index 1a685df..7bbf86d 100644
--- a/liblog/tests/Android.mk
+++ b/liblog/tests/Android.mk
@@ -57,7 +57,8 @@
 test_src_files := \
     liblog_test.cpp \
     log_id_test.cpp \
-    log_radio_test.cpp
+    log_radio_test.cpp \
+    log_system_test.cpp
 
 # to prevent breaking the build if bionic not relatively visible to us
 ifneq ($(wildcard $(LOCAL_PATH)/../../../../bionic/libc/bionic/libc_logging.cpp),)
diff --git a/liblog/tests/log_system_test.cpp b/liblog/tests/log_system_test.cpp
new file mode 100644
index 0000000..b62832e
--- /dev/null
+++ b/liblog/tests/log_system_test.cpp
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2017 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 <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+
+#include <android-base/file.h>
+#include <android-base/stringprintf.h>
+#include <gtest/gtest.h>
+// Test the APIs in this standalone include file
+#include <log/log_system.h>
+
+TEST(liblog, SLOG) {
+#ifdef __ANDROID__
+    static const char content[] = "log_system.h";
+    static const char content_false[] = "log_system.h false";
+
+    // ratelimit content to 10/s to keep away from spam filters
+    // do not send identical content together to keep away from spam filters
+
+#undef LOG_TAG
+#define LOG_TAG "TEST__SLOGV"
+    SLOGV(content);
+    usleep(100000);
+#undef LOG_TAG
+#define LOG_TAG "TEST__SLOGD"
+    SLOGD(content);
+    usleep(100000);
+#undef LOG_TAG
+#define LOG_TAG "TEST__SLOGI"
+    SLOGI(content);
+    usleep(100000);
+#undef LOG_TAG
+#define LOG_TAG "TEST__SLOGW"
+    SLOGW(content);
+    usleep(100000);
+#undef LOG_TAG
+#define LOG_TAG "TEST__SLOGE"
+    SLOGE(content);
+    usleep(100000);
+#undef LOG_TAG
+#define LOG_TAG "TEST__SLOGV"
+    SLOGV_IF(true, content);
+    usleep(100000);
+    SLOGV_IF(false, content_false);
+    usleep(100000);
+#undef LOG_TAG
+#define LOG_TAG "TEST__SLOGD"
+    SLOGD_IF(true, content);
+    usleep(100000);
+    SLOGD_IF(false, content_false);
+    usleep(100000);
+#undef LOG_TAG
+#define LOG_TAG "TEST__SLOGI"
+    SLOGI_IF(true, content);
+    usleep(100000);
+    SLOGI_IF(false, content_false);
+    usleep(100000);
+#undef LOG_TAG
+#define LOG_TAG "TEST__SLOGW"
+    SLOGW_IF(true, content);
+    usleep(100000);
+    SLOGW_IF(false, content_false);
+    usleep(100000);
+#undef LOG_TAG
+#define LOG_TAG "TEST__SLOGE"
+    SLOGE_IF(true, content);
+    usleep(100000);
+    SLOGE_IF(false, content_false);
+
+    // give time for content to long-path through logger
+    sleep(1);
+
+    std::string buf = android::base::StringPrintf(
+        "logcat -b system --pid=%u -d -s"
+            " TEST__SLOGV TEST__SLOGD TEST__SLOGI TEST__SLOGW TEST__SLOGE",
+        (unsigned)getpid());
+    FILE* fp = popen(buf.c_str(), "r");
+    int count = 0;
+    int count_false = 0;
+    if (fp) {
+        if (!android::base::ReadFdToString(fileno(fp), &buf)) buf = "";
+        pclose(fp);
+        for (size_t pos = 0; (pos = buf.find(content, pos)) != std::string::npos; ++pos) {
+            ++count;
+        }
+        for (size_t pos = 0; (pos = buf.find(content_false, pos)) != std::string::npos; ++pos) {
+            ++count_false;
+        }
+    }
+    EXPECT_EQ(0, count_false);
+#if LOG_NDEBUG
+    ASSERT_EQ(8, count);
+#else
+    ASSERT_EQ(10, count);
+#endif
+
+#else
+    GTEST_LOG_(INFO) << "This test does nothing.\n";
+#endif
+}