Android: make it possible to build TF with NDK 13+. The default compiler was...

Android: make it possible to build TF with NDK 13+. The default compiler was switched from gcc to clang in 13b, which introduced a number of small incompatibilities.

PiperOrigin-RevId: 167915928

WORKSPACE

@@ -27,7 +27,6 @@ load("//tensorflow:workspace.bzl", "tf_workspace")
 #    path = "<PATH_TO_SDK>",
 #)
 #
-# Android NDK r12b is recommended (higher may cause issues with Bazel)
 #android_ndk_repository(
 #    name="androidndk",
 #    path="<PATH_TO_NDK>",

tensorflow/contrib/android/BUILD

@@ -79,6 +79,7 @@ cc_binary(
     ],
     linkopts = if_android([
         "-landroid",
+        "-ldl",
         "-llog",
         "-lm",
         "-z defs",

tensorflow/contrib/android/cmake/CMakeLists.txt

@@ -62,6 +62,7 @@ add_library(tensorflow_inference SHARED
 # Include libraries needed for hello-jni lib
 target_link_libraries(tensorflow_inference
                       android
+                      dl
                       log
                       m
                       z

tensorflow/contrib/makefile/Makefile

@@ -243,6 +243,7 @@ ifeq ($(TARGET),ANDROID)
 	CXXFLAGS +=\
 --sysroot $(NDK_ROOT)/platforms/android-21/arch-arm \
 -Wno-narrowing \
+-fomit-frame-pointer \
 -march=armv7-a \
 -mfloat-abi=softfp \
 -mfpu=neon \
@@ -267,7 +268,8 @@ $(TARGET_NSYNC_LIB) \
 -lprotobuf \
 -llog \
 -lz \
--lm
+-lm \
+-ldl
 
 	LD := $(NDK_ROOT)/toolchains/arm-linux-androideabi-4.9/prebuilt/$(OS_PATH)-x86_64/arm-linux-androideabi/bin/ld
 

tensorflow/examples/android/BUILD

@@ -29,6 +29,7 @@ cc_binary(
     defines = ["STANDALONE_DEMO_LIB"],
     linkopts = [
         "-landroid",
+        "-ldl",
         "-ljnigraphics",
         "-llog",
         "-lm",

tensorflow/examples/android/README.md

@@ -124,8 +124,8 @@ the Android NDK and SDK must be installed on your system.
 1.  Install the latest version of Bazel as per the instructions [on the Bazel
     website](https://bazel.build/versions/master/docs/install.html).
 2.  The Android NDK is required to build the native (C/C++) TensorFlow code. The
-    current recommended version is 12b, which may be found
-    [here](https://developer.android.com/ndk/downloads/older_releases.html#ndk-12b-downloads).
+    current recommended version is 14b, which may be found
+    [here](https://developer.android.com/ndk/downloads/older_releases.html#ndk-14b-downloads).
 3.  The Android SDK and build tools may be obtained
     [here](https://developer.android.com/tools/revisions/build-tools.html), or
     alternatively as part of [Android

tensorflow/tensorflow.bzl

@@ -167,11 +167,13 @@ def tf_copts():
       "-fno-exceptions",
       "-ftemplate-depth=900",
   ]) + if_cuda(["-DGOOGLE_CUDA=1"]) + if_mkl(["-DINTEL_MKL=1", "-fopenmp",]) + if_android_arm(
-      ["-mfpu=neon", "-fomit-frame-pointer"]) + if_linux_x86_64(["-msse3"]) + select({
+      ["-mfpu=neon"]) + if_linux_x86_64(["-msse3"]) + select({
           clean_dep("//tensorflow:android"): [
               "-std=c++11",
               "-DTF_LEAN_BINARY",
               "-O2",
+              "-Wno-narrowing",
+              "-fomit-frame-pointer",
           ],
           clean_dep("//tensorflow:darwin"): [],
           clean_dep("//tensorflow:windows"): WIN_COPTS,

tensorflow/tools/ci_build/Dockerfile.android

@@ -41,7 +41,7 @@ RUN cd ${ANDROID_DEV_HOME} && \
     echo y | android update sdk --no-ui -a --filter tools,platform-tools,android-${ANDROID_API_LEVEL},build-tools-${ANDROID_BUILD_TOOLS_VERSION}
 
 # Install Android NDK.
-ENV ANDROID_NDK_FILENAME android-ndk-r12b-linux-x86_64.zip
+ENV ANDROID_NDK_FILENAME android-ndk-r14b-linux-x86_64.zip
 ENV ANDROID_NDK_URL https://dl.google.com/android/repository/${ANDROID_NDK_FILENAME}
 ENV ANDROID_NDK_HOME ${ANDROID_DEV_HOME}/ndk
 ENV PATH ${PATH}:${ANDROID_NDK_HOME}