diff --git a/libcutils/Android.bp b/libcutils/Android.bp
index 58170ec..245deb1 100644
--- a/libcutils/Android.bp
+++ b/libcutils/Android.bp
@@ -53,7 +53,7 @@
     host_supported: true,
     srcs: [
         "config_utils.c",
-        "fs_config.c",
+        "fs_config.cpp",
         "canned_fs_config.c",
         "hashmap.c",
         "iosched_policy.c",
@@ -94,6 +94,9 @@
             shared: {
                 enabled: false,
             },
+            cflags: [
+                "-D_GNU_SOURCE",
+            ],
         },
 
         android: {
diff --git a/libcutils/fs_config.c b/libcutils/fs_config.cpp
similarity index 86%
rename from libcutils/fs_config.c
rename to libcutils/fs_config.cpp
index d98a923..27750fe 100644
--- a/libcutils/fs_config.c
+++ b/libcutils/fs_config.cpp
@@ -14,15 +14,12 @@
  * limitations under the License.
  */
 
-/* This file is used to define the properties of the filesystem
-** images generated by build tools (mkbootfs and mkyaffs2image) and
-** by the device side of adb.
-*/
+// This file is used to define the properties of the filesystem
+// images generated by build tools (mkbootfs and mkyaffs2image) and
+// by the device side of adb.
 
 #define LOG_TAG "fs_config"
 
-#define _GNU_SOURCE
-
 #include <errno.h>
 #include <fcntl.h>
 #include <stdbool.h>
@@ -42,8 +39,10 @@
 #define O_BINARY 0
 #endif
 
-/* My kingdom for <endian.h> */
-static inline uint16_t get2LE(const uint8_t* src) { return src[0] | (src[1] << 8); }
+// My kingdom for <endian.h>
+static inline uint16_t get2LE(const uint8_t* src) {
+    return src[0] | (src[1] << 8);
+}
 
 static inline uint64_t get8LE(const uint8_t* src) {
     uint32_t low, high;
@@ -55,14 +54,13 @@
 
 #define ALIGN(x, alignment) (((x) + ((alignment)-1)) & ~((alignment)-1))
 
-/* Rules for directories.
-** These rules are applied based on "first match", so they
-** should start with the most specific path and work their
-** way up to the root.
-*/
+// Rules for directories.
+// These rules are applied based on "first match", so they
+// should start with the most specific path and work their
+// way up to the root.
 
 static const struct fs_path_config android_dirs[] = {
-    /* clang-format off */
+    // clang-format off
     { 00770, AID_SYSTEM,       AID_CACHE,        0, "cache" },
     { 00500, AID_ROOT,         AID_ROOT,         0, "config" },
     { 00771, AID_SYSTEM,       AID_SYSTEM,       0, "data/app" },
@@ -92,25 +90,23 @@
     { 00755, AID_ROOT,         AID_SHELL,        0, "system/xbin" },
     { 00755, AID_ROOT,         AID_SHELL,        0, "vendor" },
     { 00755, AID_ROOT,         AID_ROOT,         0, 0 },
-    /* clang-format on */
+    // clang-format on
 };
 
-/* Rules for files.
-** These rules are applied based on "first match", so they
-** should start with the most specific path and work their
-** way up to the root. Prefixes ending in * denotes wildcard
-** and will allow partial matches.
-*/
+// Rules for files.
+// These rules are applied based on "first match", so they
+// should start with the most specific path and work their
+// way up to the root. Prefixes ending in * denotes wildcard
+// and will allow partial matches.
 static const char sys_conf_dir[] = "/system/etc/fs_config_dirs";
 static const char sys_conf_file[] = "/system/etc/fs_config_files";
-/* No restrictions are placed on the vendor and oem file-system config files,
- * although the developer is advised to restrict the scope to the /vendor or
- * oem/ file-system since the intent is to provide support for customized
- * portions of a separate vendor.img or oem.img.  Has to remain open so that
- * customization can also land on /system/vendor, /system/oem or /system/odm.
- * We expect build-time checking or filtering when constructing the associated
- * fs_config_* files (see build/tools/fs_config/fs_config_generate.c)
- */
+// No restrictions are placed on the vendor and oem file-system config files,
+// although the developer is advised to restrict the scope to the /vendor or
+// oem/ file-system since the intent is to provide support for customized
+// portions of a separate vendor.img or oem.img.  Has to remain open so that
+// customization can also land on /system/vendor, /system/oem or /system/odm.
+// We expect build-time checking or filtering when constructing the associated
+// fs_config_* files (see build/tools/fs_config/fs_config_generate.c)
 static const char ven_conf_dir[] = "/vendor/etc/fs_config_dirs";
 static const char ven_conf_file[] = "/vendor/etc/fs_config_files";
 static const char oem_conf_dir[] = "/oem/etc/fs_config_dirs";
@@ -125,7 +121,7 @@
 };
 
 static const struct fs_path_config android_files[] = {
-    /* clang-format off */
+    // clang-format off
     { 00644, AID_SYSTEM,    AID_SYSTEM,    0, "data/app/*" },
     { 00644, AID_SYSTEM,    AID_SYSTEM,    0, "data/app-ephemeral/*" },
     { 00644, AID_SYSTEM,    AID_SYSTEM,    0, "data/app-private/*" },
@@ -173,13 +169,13 @@
     { 00444, AID_ROOT,      AID_ROOT,      0, ven_conf_dir + 1 },
     { 00444, AID_ROOT,      AID_ROOT,      0, ven_conf_file + 1 },
 
-    /* the following two files are INTENTIONALLY set-uid, but they
-     * are NOT included on user builds. */
+    // the following two files are INTENTIONALLY set-uid, but they
+    // are NOT included on user builds.
     { 06755, AID_ROOT,      AID_ROOT,      0, "system/xbin/procmem" },
     { 04750, AID_ROOT,      AID_SHELL,     0, "system/xbin/su" },
 
-    /* the following files have enhanced capabilities and ARE included
-     * in user builds. */
+    // the following files have enhanced capabilities and ARE included
+    // in user builds.
     { 00700, AID_SYSTEM,    AID_SHELL,     CAP_MASK_LONG(CAP_BLOCK_SUSPEND),
                                               "system/bin/inputflinger" },
     { 00550, AID_LOGD,      AID_LOGD,      CAP_MASK_LONG(CAP_SYSLOG) |
@@ -190,11 +186,11 @@
                                            CAP_MASK_LONG(CAP_SETGID),
                                               "system/bin/run-as" },
 
-    /* Support FIFO scheduling mode in SurfaceFlinger. */
+    // Support FIFO scheduling mode in SurfaceFlinger.
     { 00755, AID_SYSTEM,    AID_GRAPHICS,  CAP_MASK_LONG(CAP_SYS_NICE),
                                               "system/bin/surfaceflinger" },
 
-    /* Support hostapd administering a network interface. */
+    // Support hostapd administering a network interface.
     { 00755, AID_WIFI,      AID_WIFI,      CAP_MASK_LONG(CAP_NET_ADMIN) |
                                            CAP_MASK_LONG(CAP_NET_RAW),
                                               "system/vendor/bin/hostapd" },
@@ -202,8 +198,8 @@
                                            CAP_MASK_LONG(CAP_NET_RAW),
                                               "vendor/bin/hostapd" },
 
-    /* Support Bluetooth legacy hal accessing /sys/class/rfkill
-     * Support RT scheduling in Bluetooth */
+    // Support Bluetooth legacy hal accessing /sys/class/rfkill
+    // Support RT scheduling in Bluetooth
     { 00700, AID_BLUETOOTH, AID_BLUETOOTH, CAP_MASK_LONG(CAP_NET_ADMIN) |
                                            CAP_MASK_LONG(CAP_SYS_NICE),
                                               "system/vendor/bin/hw/android.hardware.bluetooth@1.0-service" },
@@ -211,7 +207,7 @@
                                            CAP_MASK_LONG(CAP_SYS_NICE),
                                               "vendor/bin/hw/android.hardware.bluetooth@1.0-service" },
 
-    /* Support wifi_hal_legacy administering a network interface. */
+    // Support wifi_hal_legacy administering a network interface.
     { 00755, AID_WIFI,      AID_WIFI,      CAP_MASK_LONG(CAP_NET_ADMIN) |
                                            CAP_MASK_LONG(CAP_NET_RAW),
                                               "system/vendor/bin/hw/android.hardware.wifi@1.0-service" },
@@ -219,8 +215,7 @@
                                            CAP_MASK_LONG(CAP_NET_RAW),
                                               "vendor/bin/hw/android.hardware.wifi@1.0-service" },
 
-    /* A non-privileged zygote that spawns
-     * isolated processes for web rendering. */
+    // A non-privileged zygote that spawns isolated processes for web rendering.
     { 0750,  AID_ROOT,      AID_ROOT,      CAP_MASK_LONG(CAP_SETUID) |
                                            CAP_MASK_LONG(CAP_SETGID) |
                                            CAP_MASK_LONG(CAP_SETPCAP),
@@ -230,7 +225,7 @@
                                            CAP_MASK_LONG(CAP_SETPCAP),
                                               "system/bin/webview_zygote64" },
 
-    /* generic defaults */
+    // generic defaults
     { 00755, AID_ROOT,      AID_ROOT,      0, "bin/*" },
     { 00640, AID_ROOT,      AID_SHELL,     0, "fstab.*" },
     { 00750, AID_ROOT,      AID_SHELL,     0, "init*" },
@@ -244,7 +239,7 @@
     { 00755, AID_ROOT,      AID_SHELL,     0, "vendor/bin/*" },
     { 00755, AID_ROOT,      AID_SHELL,     0, "vendor/xbin/*" },
     { 00644, AID_ROOT,      AID_ROOT,      0, 0 },
-    /* clang-format on */
+    // clang-format on
 };
 
 static size_t strip(const char* path, size_t len, const char suffix[]) {
@@ -257,9 +252,9 @@
     int fd = -1;
 
     if (target_out_path && *target_out_path) {
-        /* target_out_path is the path to the directory holding content of
-         * system partition but as we cannot guarantee it ends with '/system'
-         * or with or without a trailing slash, need to strip them carefully. */
+        // target_out_path is the path to the directory holding content of
+        // system partition but as we cannot guarantee it ends with '/system'
+        // or with or without a trailing slash, need to strip them carefully.
         char* name = NULL;
         size_t len = strlen(target_out_path);
         len = strip(target_out_path, len, "/");
@@ -281,7 +276,7 @@
             return false;
         }
     } else {
-        /* If name ends in * then allow partial matches. */
+        // If name ends in * then allow partial matches.
         if (prefix[len - 1] == '*') {
             return !strncmp(prefix, path, len - 1);
         }
@@ -317,7 +312,7 @@
                 ALOGE("%s len is corrupted", conf[which][dir]);
                 break;
             }
-            prefix = calloc(1, remainder);
+            prefix = static_cast<char*>(calloc(1, remainder));
             if (!prefix) {
                 ALOGE("%s out of memory", conf[which][dir]);
                 break;
@@ -328,7 +323,7 @@
                 break;
             }
             len = strnlen(prefix, remainder);
-            if (len >= remainder) { /* missing a terminating null */
+            if (len >= remainder) {  // missing a terminating null
                 free(prefix);
                 ALOGE("%s is corrupted", conf[which][dir]);
                 break;