C++98 (stlport) support for core FlatBuffers and FlexBuffers.

* Added internal - limited - implementation of flatbuffers::unique_ptr
  for STLs that don't ship with std::unique_ptr.  In C++11 and beyond
  this is just an alias for std::unique_ptr.
* Aliased used type traits structs is_scalar is_floating_point is_unsigned
  into flatbuffers namespace so they can be replaced in C++98 implementations.
  Right now these point at stlport's TR1 implementations.
* Wrapped vector::data() in vector_data().
* Wrapped vector::emplace_back() in vector_emplace_back().
* Wrapper string::back() in string_back().
* Added variants of FlatBufferBuilder::CreateVector() and
  FlatBufferBuilder::CreateVectorOfStructs() that allow the use of plain
  function pointers.
  Generated code has also been modified to use plain functions to build objects
  rather than std::function() so all generated code will work in C++98
  applications.
* Added flexbuffers::Builder::Vector(), flexbuffers::Builder::TypedVector()
  and flexbuffers::Builder::Map() methods that allow the use of plain function
  pointers.
* Changed Parser to internally use plain function pointers when parsing table
  and vector delimiters.
* Added specializations of NumToString() for 64-bit types that aren't supported
  by stringstream in stlport.
* Overloaded numeric_limits for 64-bit types not supported by stlport.
* Replaced build_apk.sh (which was broken by deprecation of the
  "android" tool in the Android SDK) with build.gradle and the
  appropriate gradle wrapper to build an APK.
* Switched Android build to build against all STL variants.
* Updated travis configuration to build Android test and sample.

Tested:
* Verified all tests continue to work on Linux, OSX and Android.
* Verified Travis build is green.

Change-Id: I9e634363793f85b9f141d21454b10686020a2065

11 files changed, 391 insertions, 534 deletions

diff --git a/samples/android/AndroidManifest.xml b/samples/android/AndroidManifest.xml
index 0fa3dcfc..352e0fad 100755
--- a/samples/android/AndroidManifest.xml
+++ b/samples/android/AndroidManifest.xml
@@ -17,17 +17,14 @@
  -->
 <!-- BEGIN_INCLUDE(manifest) -->
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-        package="com.samples.FlatBufferSample"
-        android:versionCode="1"
-        android:versionName="1.0">
+          package="com.samples.FlatBufferSample">
 
     <uses-feature android:glEsVersion="0x00020000"></uses-feature>
-    <!-- This is the platform API where NativeActivity was introduced. -->
-    <uses-sdk android:minSdkVersion="9" />
 
     <!-- This .apk has no Java code itself, so set hasCode to false. -->
-    <application android:label="@string/app_name" android:hasCode="false">
-
+    <application android:label="@string/app_name"
+                 android:hasCode="false"
+                 android:allowBackup="false">
         <!-- Our activity is the built-in NativeActivity framework class.
              This will take care of integrating with our NDK code. -->
         <activity android:name="android.app.NativeActivity"
diff --git a/samples/android/build.gradle b/samples/android/build.gradle
new file mode 100644
index 00000000..e6af6d6f
--- /dev/null
+++ b/samples/android/build.gradle
@@ -0,0 +1,108 @@
+// Copyright (c) 2017 Google, Inc.
+//
+// This software is provided 'as-is', without any express or implied
+// warranty.  In no event will the authors be held liable for any damages
+// arising from the use of this software.
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+// 1. The origin of this software must not be misrepresented; you must not
+// claim that you wrote the original software. If you use this software
+// in a product, an acknowledgment in the product documentation would be
+// appreciated but is not required.
+// 2. Altered source versions must be plainly marked as such, and must not be
+// misrepresented as being the original software.
+// 3. This notice may not be removed or altered from any source distribution.
+
+buildscript {
+  repositories {
+    jcenter()
+  }
+  dependencies {
+    classpath 'com.android.tools.build:gradle:2.3.0'
+  }
+}
+
+allprojects {
+  repositories {
+    jcenter()
+  }
+}
+
+apply plugin: 'com.android.application'
+
+android {
+  compileSdkVersion 25
+  buildToolsVersion '25.0.2'
+
+  sourceSets {
+    main {
+      manifest.srcFile 'AndroidManifest.xml'
+      res.srcDirs = ['res']
+    }
+  }
+
+  externalNativeBuild {
+    ndkBuild {
+      path "jni/Android.mk"
+    }
+  }
+
+  defaultConfig {
+    applicationId 'com.samples.FlatBufferSample'
+    // This is the platform API where NativeActivity was introduced.
+    minSdkVersion 9
+    targetSdkVersion 25
+    versionCode 1
+    versionName "1.0"
+
+    buildTypes {
+      release {
+        minifyEnabled false
+      }
+    }
+
+    externalNativeBuild {
+      ndkBuild {
+        targets "FlatBufferSample"
+        arguments "-j" + Runtime.getRuntime().availableProcessors()
+        abiFilters "armeabi", "armeabi-v7a", "arm64-v8a", "x86", "x86_64"
+      }
+    }
+  }
+
+  lintOptions {
+    abortOnError false
+  }
+
+  // Build with each STL variant.
+  productFlavors {
+    stlport {
+      applicationIdSuffix ".stlport"
+      versionNameSuffix "-stlport"
+      externalNativeBuild {
+        ndkBuild {
+          arguments "APP_STL=stlport_static"
+        }
+      }
+    }
+    gnustl {
+      applicationIdSuffix ".gnustl"
+      versionNameSuffix "-gnustl"
+      externalNativeBuild {
+        ndkBuild {
+          arguments "APP_STL=gnustl_static"
+        }
+      }
+    }
+    libcpp {
+      applicationIdSuffix ".libcpp"
+      versionNameSuffix "-libcpp"
+      externalNativeBuild {
+        ndkBuild {
+          arguments "APP_STL=c++_static"
+        }
+      }
+    }
+  }
+}
diff --git a/samples/android/build_apk.sh b/samples/android/build_apk.sh
deleted file mode 100755
index 1b9f4a45..00000000
--- a/samples/android/build_apk.sh
+++ /dev/null
@@ -1,511 +0,0 @@
-#!/bin/bash -eu
-#
-# Copyright (c) 2013 Google, Inc.
-#
-# This software is provided 'as-is', without any express or implied
-# warranty.  In no event will the authors be held liable for any damages
-# arising from the use of this software.
-# Permission is granted to anyone to use this software for any purpose,
-# including commercial applications, and to alter it and redistribute it
-# freely, subject to the following restrictions:
-# 1. The origin of this software must not be misrepresented; you must not
-# claim that you wrote the original software. If you use this software
-# in a product, an acknowledgment in the product documentation would be
-# appreciated but is not required.
-# 2. Altered source versions must be plainly marked as such, and must not be
-# misrepresented as being the original software.
-# 3. This notice may not be removed or altered from any source distribution.
-#
-# Build, deploy, debug / execute a native Android package based upon
-# NativeActivity.
-
-declare -r script_directory=$(dirname $0)
-declare -r android_root=${script_directory}/../../../../../../
-declare -r script_name=$(basename $0)
-declare -r android_manifest=AndroidManifest.xml
-declare -r os_name=$(uname -s)
-
-# Minimum Android target version supported by this project.
-: ${BUILDAPK_ANDROID_TARGET_MINVERSION:=10}
-# Directory containing the Android SDK
-# (http://developer.android.com/sdk/index.html).
-: ${ANDROID_SDK_HOME:=}
-# Directory containing the Android NDK
-# (http://developer.android.com/tools/sdk/ndk/index.html).
-: ${NDK_HOME:=}
-
-# Display script help and exit.
-usage() {
-  echo "
-Build the Android package in the current directory and deploy it to a
-connected device.
-
-Usage: ${script_name} \\
-         [ADB_DEVICE=serial_number] [BUILD=0] [DEPLOY=0] [RUN_DEBUGGER=1] \
-         [LAUNCH=0] [SWIG_BIN=swig_binary_directory] [SWIG_LIB=swig_include_directory] [ndk-build arguments ...]
-
-ADB_DEVICE=serial_number:
-  serial_number specifies the device to deploy the built apk to if multiple
-  Android devices are connected to the host.
-BUILD=0:
-  Disables the build of the package.
-DEPLOY=0:
-  Disables the deployment of the built apk to the Android device.
-RUN_DEBUGGER=1:
-  Launches the application in gdb after it has been deployed.  To debug in
-  gdb, NDK_DEBUG=1 must also be specified on the command line to build a
-  debug apk.
-LAUNCH=0:
-  Disable the launch of the apk on the Android device.
-SWIG_BIN=swig_binary_directory:
-  The directory where the SWIG binary lives. No need to set this if SWIG is
-  installed and point to from your PATH variable.
-SWIG_LIB=swig_include_directory:
-  The directory where SWIG shared include files are, usually obtainable from
-  commandline with \"swig -swiglib\". No need to set this if SWIG is installed
-  and point to from your PATH variable.
-ndk-build arguments...:
-  Additional arguments for ndk-build.  See ndk-build -h for more information.
-" >&2
-  exit 1
-}
-
-# Get the number of CPU cores present on the host.
-get_number_of_cores() {
-  case ${os_name} in
-    Darwin)
-      sysctl hw.ncpu | awk '{ print $2 }'
-      ;;
-    CYGWIN*|Linux)
-      awk '/^processor/ { n=$3 } END { print n + 1 }' /proc/cpuinfo
-      ;;
-    *)
-      echo 1
-      ;;
-  esac
-}
-
-# Get the package name from an AndroidManifest.xml file.
-get_package_name_from_manifest() {
-  xmllint --xpath 'string(/manifest/@package)' "${1}"
-}
-
-# Get the library name from an AndroidManifest.xml file.
-get_library_name_from_manifest() {
-  echo "\
-setns android=http://schemas.android.com/apk/res/android
-xpath string(/manifest/application/activity\
-[@android:name=\"android.app.NativeActivity\"]/meta-data\
-[@android:name=\"android.app.lib_name\"]/@android:value)" |
-  xmllint --shell "${1}" | awk '/Object is a string/ { print $NF }'
-}
-
-# Get the number of Android devices connected to the system.
-get_number_of_devices_connected() {
-  adb devices -l | \
-    awk '/^..*$/ { if (p) { print $0 } }
-         /List of devices attached/ { p = 1 }' | \
-    wc -l
-  return ${PIPESTATUS[0]}
-}
-
-# Kill a process and its' children.  This is provided for cygwin which
-# doesn't ship with pkill.
-kill_process_group() {
-  local parent_pid="${1}"
-  local child_pid=
-  for child_pid in $(ps -f | \
-                     awk '{ if ($3 == '"${parent_pid}"') { print $2 } }'); do
-    kill_process_group "${child_pid}"
-  done
-  kill "${parent_pid}" 2>/dev/null
-}
-
-# Find and run "adb".
-adb() {
-  local adb_path=
-  for path in "$(which adb 2>/dev/null)" \
-              "${ANDROID_SDK_HOME}/sdk/platform-tools/adb" \
-              "${android_root}/prebuilts/sdk/platform-tools/adb"; do
-    if [[ -e "${path}" ]]; then
-      adb_path="${path}"
-      break
-    fi
-  done
-  if [[ "${adb_path}" == "" ]]; then
-    echo -e "Unable to find adb." \
-           "\nAdd the Android ADT sdk/platform-tools directory to the" \
-           "PATH." >&2
-    exit 1
-  fi
-  "${adb_path}" "$@"
-}
-
-# Find and run "android".
-android() {
-  local android_executable=android
-  if echo "${os_name}" | grep -q CYGWIN; then
-    android_executable=android.bat
-  fi
-  local android_path=
-  for path in "$(which ${android_executable})" \
-              "${ANDROID_SDK_HOME}/sdk/tools/${android_executable}" \
-              "${android_root}/prebuilts/sdk/tools/${android_executable}"; do
-    if [[ -e "${path}" ]]; then
-      android_path="${path}"
-      break
-    fi
-  done
-  if [[ "${android_path}" == "" ]]; then
-    echo -e "Unable to find android tool." \
-           "\nAdd the Android ADT sdk/tools directory to the PATH." >&2
-    exit 1
-  fi
-  # Make sure ant is installed.
-  if [[ "$(which ant)" == "" ]]; then
-    echo -e "Unable to find ant." \
-            "\nPlease install ant and add to the PATH." >&2
-    exit 1
-  fi
-
-  "${android_path}" "$@"
-}
-
-# Find and run "ndk-build"
-ndkbuild() {
-  local ndkbuild_path=
-  for path in "$(which ndk-build 2>/dev/null)" \
-              "${NDK_HOME}/ndk-build" \
-              "${android_root}/prebuilts/ndk/current/ndk-build"; do
-    if [[ -e "${path}" ]]; then
-      ndkbuild_path="${path}"
-      break
-    fi
-  done
-  if [[ "${ndkbuild_path}" == "" ]]; then
-    echo -e "Unable to find ndk-build." \
-            "\nAdd the Android NDK directory to the PATH." >&2
-    exit 1
-  fi
-  "${ndkbuild_path}" "$@"
-}
-
-# Get file modification time of $1 in seconds since the epoch.
-stat_mtime() {
-  local filename="${1}"
-  case ${os_name} in
-    Darwin) stat -f%m "${filename}" 2>/dev/null || echo 0 ;;
-    *) stat -c%Y "${filename}" 2>/dev/null || echo 0 ;;
-  esac
-}
-
-# Build the native (C/C++) build targets in the current directory.
-build_native_targets() {
-  # Save the list of output modules in the install directory so that it's
-  # possible to restore their timestamps after the build is complete.  This
-  # works around a bug in ndk/build/core/setup-app.mk which results in the
-  # unconditional execution of the clean-installed-binaries rule.
-  restore_libraries="$(find libs -type f 2>/dev/null | \
-                       sed -E 's@^libs/(.*)@\1@')"
-
-  # Build native code.
-  ndkbuild -j$(get_number_of_cores) "$@"
-
-  # Restore installed libraries.
-  # Obviously this is a nasty hack (along with ${restore_libraries} above) as
-  # it assumes it knows where the NDK will be placing output files.
-  (
-    IFS=$'\n'
-    for libpath in ${restore_libraries}; do
-      source_library="obj/local/${libpath}"
-      target_library="libs/${libpath}"
-      if [[ -e "${source_library}" ]]; then
-        cp -a "${source_library}" "${target_library}"
-      fi
-    done
-  )
-}
-
-# Select the oldest installed android build target that is at least as new as
-# BUILDAPK_ANDROID_TARGET_MINVERSION.  If a suitable build target isn't found,
-# this function prints an error message and exits with an error.
-select_android_build_target() {
-  local -r android_targets_installed=$( \
-    android list targets | \
-    awk -F'"' '/^id:.*android/ { print $2 }')
-  local android_build_target=
-  for android_target in $(echo "${android_targets_installed}" | \
-                          awk -F- '{ print $2 }' | sort -n); do
-    local isNumber='^[0-9]+$'
-    # skip preview API releases e.g. 'android-L'
-    if [[ $android_target =~ $isNumber ]]; then
-      if [[ $((android_target)) -ge \
-          $((BUILDAPK_ANDROID_TARGET_MINVERSION)) ]]; then
-        android_build_target="android-${android_target}"
-        break
-      fi
-    # else
-      # The API version is a letter, so skip it.
-    fi
-  done
-  if [[ "${android_build_target}" == "" ]]; then
-    echo -e \
-      "Found installed Android targets:" \
-      "$(echo ${android_targets_installed} | sed 's/ /\n  /g;s/^/\n  /;')" \
-      "\nAndroid SDK platform" \
-      "android-$((BUILDAPK_ANDROID_TARGET_MINVERSION))" \
-      "must be installed to build this project." \
-      "\nUse the \"android\" application to install API" \
-      "$((BUILDAPK_ANDROID_TARGET_MINVERSION)) or newer." >&2
-    exit 1
-  fi
-  echo "${android_build_target}"
-}
-
-# Sign unsigned apk $1 and write the result to $2 with key store file $3 and
-# password $4.
-# If a key store file $3 and password $4 aren't specified, a temporary
-# (60 day) key is generated and used to sign the package.
-sign_apk() {
-  local unsigned_apk="${1}"
-  local signed_apk="${2}"
-  if [[ $(stat_mtime "${unsigned_apk}") -gt \
-          $(stat_mtime "${signed_apk}") ]]; then
-    local -r key_alias=$(basename ${signed_apk} .apk)
-    local keystore="${3}"
-    local key_password="${4}"
-    [[ "${keystore}" == "" ]] && keystore="${unsigned_apk}.keystore"
-    [[ "${key_password}" == "" ]] && \
-      key_password="${key_alias}123456"
-    if [[ ! -e ${keystore} ]]; then
-      keytool -genkey -v -dname "cn=, ou=${key_alias}, o=fpl" \
-        -storepass ${key_password} \
-        -keypass ${key_password} -keystore ${keystore} \
-        -alias ${key_alias} -keyalg RSA -keysize 2048 -validity 60
-    fi
-    cp "${unsigned_apk}" "${signed_apk}"
-    jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 \
-      -keystore ${keystore} -storepass ${key_password} \
-      -keypass ${key_password} "${signed_apk}" ${key_alias}
-  fi
-}
-
-# Build the apk $1 for package filename $2 in the current directory using the
-# ant build target $3.
-build_apk() {
-  local -r output_apk="${1}"
-  local -r package_filename="${2}"
-  local -r ant_target="${3}"
-  # Get the list of installed android targets and select the oldest target
-  # that is at least as new as BUILDAPK_ANDROID_TARGET_MINVERSION.
-  local -r android_build_target=$(select_android_build_target)
-  [[ "${android_build_target}" == "" ]] && exit 1
-  echo "Building ${output_apk} for target ${android_build_target}" >&2
-
-  # Create / update build.xml and local.properties files.
-  if [[ $(stat_mtime "${android_manifest}") -gt \
-          $(stat_mtime build.xml) ]]; then
-    android update project --target "${android_build_target}" \
-                           -n ${package_filename} --path .
-  fi
-
-  # Use ant to build the apk.
-  ant -quiet ${ant_target}
-
-  # Sign release apks with a temporary key as these packages will not be
-  # redistributed.
-  local unsigned_apk="bin/${package_filename}-${ant_target}-unsigned.apk"
-  if [[ "${ant_target}" == "release" ]]; then
-    sign_apk "${unsigned_apk}" "${output_apk}" "" ""
-  fi
-}
-
-# Uninstall package $1 and install apk $2 on device $3 where $3 is "-s device"
-# or an empty string.  If $3 is an empty string adb will fail when multiple
-# devices are connected to the host system.
-install_apk() {
-  local -r uninstall_package_name="${1}"
-  local -r install_apk="${2}"
-  local -r adb_device="${3}"
-  # Uninstall the package if it's already installed.
-  adb ${adb_device} uninstall "${uninstall_package_name}" 1>&2 > /dev/null || \
-    true # no error check
-
-  # Install the apk.
-  # NOTE: The following works around adb not returning an error code when
-  # it fails to install an apk.
-  echo "Install ${install_apk}" >&2
-  local -r adb_install_result=$(adb ${adb_device} install "${install_apk}")
-  echo "${adb_install_result}"
-  if echo "${adb_install_result}" | grep -qF 'Failure ['; then
-    exit 1
-  fi
-}
-
-# Launch previously installed package $1 on device $2.
-# If $2 is an empty string adb will fail when multiple devices are connected
-# to the host system.
-launch_package() {
-  (
-    # Determine the SDK version of Android on the device.
-    local -r android_sdk_version=$(
-      adb ${adb_device} shell cat system/build.prop | \
-      awk -F= '/ro.build.version.sdk/ {
-                 v=$2; sub(/[ \r\n]/, "", v); print v
-               }')
-
-    # Clear logs from previous runs.
-    # Note that logcat does not just 'tail' the logs, it dumps the entire log
-    # history.
-    adb ${adb_device} logcat -c
-
-    local finished_msg='Displayed '"${package_name}"
-    local timeout_msg='Activity destroy timeout.*'"${package_name}"
-    # Maximum time to wait before stopping log monitoring.  0 = infinity.
-    local launch_timeout=0
-    # If this is a Gingerbread device, kill log monitoring after 10 seconds.
-    if [[ $((android_sdk_version)) -le 10 ]]; then
-      launch_timeout=10
-    fi
-    # Display logcat in the background.
-    # Stop displaying the log when the app launch / execution completes or the
-    # logcat
-    (
-      adb ${adb_device} logcat | \
-        awk "
-          {
-            print \$0
-          }
-
-          /ActivityManager.*: ${finished_msg}/ {
-            exit 0
-          }
-
-          /ActivityManager.*: ${timeout_msg}/ {
-            exit 0
-          }" &
-      adb_logcat_pid=$!;
-      if [[ $((launch_timeout)) -gt 0 ]]; then
-        sleep $((launch_timeout));
-        kill ${adb_logcat_pid};
-      else
-        wait ${adb_logcat_pid};
-      fi
-    ) &
-    logcat_pid=$!
-    # Kill adb logcat if this shell exits.
-    trap "kill_process_group ${logcat_pid}" SIGINT SIGTERM EXIT
-
-    # If the SDK is newer than 10, "am" supports stopping an activity.
-    adb_stop_activity=
-    if [[ $((android_sdk_version)) -gt 10 ]]; then
-      adb_stop_activity=-S
-    fi
-
-    # Launch the activity and wait for it to complete.
-    adb ${adb_device} shell am start ${adb_stop_activity} -n \
-      ${package_name}/android.app.NativeActivity
-
-    wait "${logcat_pid}"
-  )
-}
-
-# See usage().
-main() {
-  # Parse arguments for this script.
-  local adb_device=
-  local ant_target=release
-  local disable_deploy=0
-  local disable_build=0
-  local run_debugger=0
-  local launch=1
-  local build_package=1
-  for opt; do
-    case ${opt} in
-      # NDK_DEBUG=0 tells ndk-build to build this as debuggable but to not
-      # modify the underlying code whereas NDK_DEBUG=1 also builds as debuggable
-      # but does modify the code
-      NDK_DEBUG=1) ant_target=debug ;;
-      NDK_DEBUG=0) ant_target=debug ;;
-      ADB_DEVICE*) adb_device="$(\
-        echo "${opt}" | sed -E 's/^ADB_DEVICE=([^ ]+)$/-s \1/;t;s/.*//')" ;;
-      BUILD=0) disable_build=1 ;;
-      DEPLOY=0) disable_deploy=1 ;;
-      RUN_DEBUGGER=1) run_debugger=1 ;;
-      LAUNCH=0) launch=0 ;;
-      clean) build_package=0 disable_deploy=1 launch=0 ;;
-      -h|--help|help) usage ;;
-    esac
-  done
-
-  # If a target device hasn't been specified and multiple devices are connected
-  # to the host machine, display an error.
-  local -r devices_connected=$(get_number_of_devices_connected)
-  if [[ "${adb_device}" == "" && $((devices_connected)) -gt 1 && \
-        ($((disable_deploy)) -eq 0 || $((launch)) -ne 0 || \
-         $((run_debugger)) -ne 0) ]]; then
-    if [[ $((disable_deploy)) -ne 0 ]]; then
-      echo "Deployment enabled, disable using DEPLOY=0" >&2
-    fi
-    if [[ $((launch)) -ne 0 ]]; then
-     echo "Launch enabled." >&2
-    fi
-    if [[ $((disable_deploy)) -eq 0 ]]; then
-      echo "Deployment enabled." >&2
-    fi
-    if [[ $((run_debugger)) -ne 0 ]]; then
-      echo "Debugger launch enabled." >&2
-    fi
-    echo "
-Multiple Android devices are connected to this host.  Either disable deployment
-and execution of the built .apk using:
-  \"${script_name} DEPLOY=0 LAUNCH=0\"
-
-or specify a device to deploy to using:
-  \"${script_name} ADB_DEVICE=\${device_serial}\".
-
-The Android devices connected to this machine are:
-$(adb devices -l)
-" >&2
-    exit 1
-  fi
-
-  if [[ $((disable_build)) -eq 0 ]]; then
-    # Build the native target.
-    build_native_targets "$@"
-  fi
-
-  # Get the package name from the manifest.
-  local -r package_name=$(get_package_name_from_manifest "${android_manifest}")
-  if [[ "${package_name}" == "" ]]; then
-    echo -e "No package name specified in ${android_manifest},"\
-            "skipping apk build, deploy"
-            "\nand launch steps." >&2
-    exit 0
-  fi
-  local -r package_basename=${package_name/*./}
-  local package_filename=$(get_library_name_from_manifest ${android_manifest})
-  [[ "${package_filename}" == "" ]] && package_filename="${package_basename}"
-
-  # Output apk name.
-  local -r output_apk="bin/${package_filename}-${ant_target}.apk"
-
-  if [[ $((disable_build)) -eq 0 && $((build_package)) -eq 1 ]]; then
-    # Build the apk.
-    build_apk "${output_apk}" "${package_filename}" "${ant_target}"
-  fi
-
-  # Deploy to the device.
-  if [[ $((disable_deploy)) -eq 0 ]]; then
-    install_apk "${package_name}" "${output_apk}" "${adb_device}"
-  fi
-
-  if [[ "${ant_target}" == "debug" && $((run_debugger)) -eq 1 ]]; then
-    # Start debugging.
-    ndk-gdb ${adb_device} --start
-  elif [[ $((launch)) -eq 1 ]]; then
-    launch_package "${package_name}" "${adb_device}"
-  fi
-}
-
-main "$@"
diff --git a/samples/android/gradle/wrapper/gradle-wrapper.jar b/samples/android/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 00000000..b4163b81
--- /dev/null
+++ b/samples/android/gradle/wrapper/gradle-wrapper.jar
diff --git a/samples/android/gradle/wrapper/gradle-wrapper.properties b/samples/android/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 00000000..1e1168cf
--- /dev/null
+++ b/samples/android/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Mon Jun 19 11:54:59 PDT 2017
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.0-all.zip
diff --git a/samples/android/gradlew b/samples/android/gradlew
new file mode 100755
index 00000000..cccdd3d5
--- /dev/null
+++ b/samples/android/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/samples/android/gradlew.bat b/samples/android/gradlew.bat
new file mode 100644
index 00000000..f9553162
--- /dev/null
+++ b/samples/android/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/samples/android/jni/Android.mk b/samples/android/jni/Android.mk
index 6f22d285..917c2f9e 100755
--- a/samples/android/jni/Android.mk
+++ b/samples/android/jni/Android.mk
@@ -38,7 +38,7 @@ $(info $(LOCAL_C_INCLUDES))
 LOCAL_SRC_FILES := main.cpp
 
 LOCAL_CPPFLAGS := -std=c++11 -fexceptions -Wall -Wno-literal-suffix
-LOCAL_LDLIBS := -llog -landroid
+LOCAL_LDLIBS := -llog -landroid -latomic
 LOCAL_ARM_MODE := arm
 LOCAL_STATIC_LIBRARIES := android_native_app_glue flatbuffers
 
diff --git a/samples/android/jni/Application.mk b/samples/android/jni/Application.mk
index 2fc9c737..ca9e8004 100755
--- a/samples/android/jni/Application.mk
+++ b/samples/android/jni/Application.mk
@@ -13,10 +13,8 @@
 # 2. Altered source versions must be plainly marked as such, and must not be
 # misrepresented as being the original software.
 # 3. This notice may not be removed or altered from any source distribution.
-APP_PLATFORM := android-10
+APP_PLATFORM := android-9
 APP_PROJECT_PATH := $(call my-dir)/..
-APP_STL := gnustl_static
-
+APP_STL ?= stlport_static
 APP_ABI := armeabi-v7a
-
 APP_CPPFLAGS += -std=c++11
diff --git a/samples/android_sample.sh b/samples/android_sample.sh
index ead8fd80..53633aca 100755
--- a/samples/android_sample.sh
+++ b/samples/android_sample.sh
@@ -29,8 +29,7 @@ fi
 
 # Execute `build_apk.sh` to build and run the android app.
 cd android
-./build_apk.sh
+./gradlew build
+
+
 
-# Cleanup the temporary files.
-rm build.xml local.properties proguard-project.txt project.properties
-rm -rf bin libs obj
diff --git a/samples/monster_generated.h b/samples/monster_generated.h
index f4bdbb34..9fca774d 100644
--- a/samples/monster_generated.h
+++ b/samples/monster_generated.h
@@ -103,6 +103,7 @@ struct EquipmentUnion {
 
   void Reset();
 
+#ifndef FLATBUFFERS_CPP98_STL
   template <typename T>
   void Set(T&& val) {
     Reset();
@@ -111,6 +112,7 @@ struct EquipmentUnion {
       value = new T(std::forward<T>(val));
     }
   }
+#endif  // FLATBUFFERS_CPP98_STL
 
   static void *UnPack(const void *obj, Equipment type, const flatbuffers::resolver_function_t *resolver);
   flatbuffers::Offset<void> Pack(flatbuffers::FlatBufferBuilder &_fbb, const flatbuffers::rehasher_function_t *_rehasher = nullptr) const;
@@ -165,13 +167,13 @@ STRUCT_END(Vec3, 12);
 
 struct MonsterT : public flatbuffers::NativeTable {
   typedef Monster TableType;
-  std::unique_ptr<Vec3> pos;
+  flatbuffers::unique_ptr<Vec3> pos;
   int16_t mana;
   int16_t hp;
   std::string name;
   std::vector<uint8_t> inventory;
   Color color;
-  std::vector<std::unique_ptr<WeaponT>> weapons;
+  std::vector<flatbuffers::unique_ptr<WeaponT>> weapons;
   EquipmentUnion equipped;
   MonsterT()
       : mana(150),
@@ -461,13 +463,13 @@ inline MonsterT *Monster::UnPack(const flatbuffers::resolver_function_t *_resolv
 inline void Monster::UnPackTo(MonsterT *_o, const flatbuffers::resolver_function_t *_resolver) const {
   (void)_o;
   (void)_resolver;
-  { auto _e = pos(); if (_e) _o->pos = std::unique_ptr<Vec3>(new Vec3(*_e)); };
+  { auto _e = pos(); if (_e) _o->pos = flatbuffers::unique_ptr<Vec3>(new Vec3(*_e)); };
   { auto _e = mana(); _o->mana = _e; };
   { auto _e = hp(); _o->hp = _e; };
   { auto _e = name(); if (_e) _o->name = _e->str(); };
   { auto _e = inventory(); if (_e) { _o->inventory.resize(_e->size()); for (flatbuffers::uoffset_t _i = 0; _i < _e->size(); _i++) { _o->inventory[_i] = _e->Get(_i); } } };
   { auto _e = color(); _o->color = _e; };
-  { auto _e = weapons(); if (_e) { _o->weapons.resize(_e->size()); for (flatbuffers::uoffset_t _i = 0; _i < _e->size(); _i++) { _o->weapons[_i] = std::unique_ptr<WeaponT>(_e->Get(_i)->UnPack(_resolver)); } } };
+  { auto _e = weapons(); if (_e) { _o->weapons.resize(_e->size()); for (flatbuffers::uoffset_t _i = 0; _i < _e->size(); _i++) { _o->weapons[_i] = flatbuffers::unique_ptr<WeaponT>(_e->Get(_i)->UnPack(_resolver)); } } };
   { auto _e = equipped_type(); _o->equipped.type = _e; };
   { auto _e = equipped(); if (_e) _o->equipped.value = EquipmentUnion::UnPack(_e, equipped_type(), _resolver); };
 }
@@ -479,13 +481,14 @@ inline flatbuffers::Offset<Monster> Monster::Pack(flatbuffers::FlatBufferBuilder
 inline flatbuffers::Offset<Monster> CreateMonster(flatbuffers::FlatBufferBuilder &_fbb, const MonsterT *_o, const flatbuffers::rehasher_function_t *_rehasher) {
   (void)_rehasher;
   (void)_o;
+  struct _VectorArgs { flatbuffers::FlatBufferBuilder *__fbb; const MonsterT* __o; const flatbuffers::rehasher_function_t *__rehasher; } _va = { &_fbb, _o, _rehasher}; (void)_va;
   auto _pos = _o->pos ? _o->pos.get() : 0;
   auto _mana = _o->mana;
   auto _hp = _o->hp;
   auto _name = _o->name.size() ? _fbb.CreateString(_o->name) : 0;
   auto _inventory = _o->inventory.size() ? _fbb.CreateVector(_o->inventory) : 0;
   auto _color = _o->color;
-  auto _weapons = _o->weapons.size() ? _fbb.CreateVector<flatbuffers::Offset<Weapon>>(_o->weapons.size(), [&](size_t i) { return CreateWeapon(_fbb, _o->weapons[i].get(), _rehasher); }) : 0;
+  auto _weapons = _o->weapons.size() ? _fbb.CreateVector<flatbuffers::Offset<Weapon>> (_o->weapons.size(), [](size_t i, _VectorArgs *__va) { return CreateWeapon(*__va->__fbb, __va->__o->weapons[i].get(), __va->__rehasher); }, &_va ) : 0;
   auto _equipped_type = _o->equipped.type;
   auto _equipped = _o->equipped.Pack(_fbb);
   return MyGame::Sample::CreateMonster(
@@ -521,6 +524,7 @@ inline flatbuffers::Offset<Weapon> Weapon::Pack(flatbuffers::FlatBufferBuilder &
 inline flatbuffers::Offset<Weapon> CreateWeapon(flatbuffers::FlatBufferBuilder &_fbb, const WeaponT *_o, const flatbuffers::rehasher_function_t *_rehasher) {
   (void)_rehasher;
   (void)_o;
+  struct _VectorArgs { flatbuffers::FlatBufferBuilder *__fbb; const WeaponT* __o; const flatbuffers::rehasher_function_t *__rehasher; } _va = { &_fbb, _o, _rehasher}; (void)_va;
   auto _name = _o->name.size() ? _fbb.CreateString(_o->name) : 0;
   auto _damage = _o->damage;
   return MyGame::Sample::CreateWeapon(
@@ -616,10 +620,10 @@ inline void FinishMonsterBuffer(
   fbb.Finish(root);
 }
 
-inline std::unique_ptr<MonsterT> UnPackMonster(
+inline flatbuffers::unique_ptr<MonsterT> UnPackMonster(
     const void *buf,
     const flatbuffers::resolver_function_t *res = nullptr) {
-  return std::unique_ptr<MonsterT>(GetMonster(buf)->UnPack(res));
+  return flatbuffers::unique_ptr<MonsterT>(GetMonster(buf)->UnPack(res));
 }
 
 }  // namespace Sample