android NDK ndk-build error

2
votes

I'm new to Android studio and android NDK. I'm trying to compile a simple hello.c program with android NDK for a class assignment. I've followed the following project instructions but get an error:

  1. Create a c program

  2. create Android.mk with following contents:

    LOCAL_PATH := $(call my-dir)
    include $(CLEAR_VARS)
    LOCAL_MODULE := hello.out
    LOCAL_SRC_FILES :=hello.c
    include $(BUILD_EXECUTABLE)

  3. Create Application.mk with following content:

    APP_ABI := armeabi
    APP_PLATFORM := android-10
    APP_STL := stlport_static
    APP_BUILD_SCRITP := Android.mk

  4. Put hello.c, Android.mk, Application.mk into same folder x.

  5. go to folder x

  6. run command:

    export NDK_PROJECT_PATH=.

  7. Run command

    [NDK_dir]/ndk-build NDK_APPLICATION_MK=./Application.mk

  8. the executable will be generated at ./libs/armeabi/hello.out

But I get this error when following those instructions:

/home/justin/Desktop/android-ndk-r16/build/core/add-application.mk:49: Application.mk: No such file or directory
Android NDK: APP_PLATFORM not set. Defaulting to minimum supported version android-14.    
Android NDK: There is no Android.mk under ./jni    
Android NDK: If this is intentional  please define APP_BUILD_SCRIPT to point   
Android NDK: to a valid NDK build script.    
/home/justin/Desktop/android-ndk-r16/build/core/add-application.mk:116: *** Android NDK: Aborting...    .  Stop.

I installed android NDK components through Andoird studio SDK and my [NDK_DiR] is /home/justin/Android/Sdk/ndk-bundle

1
androidcandroid-ndkndk-build
Fixed. Step 6 should be "export NDK_PROJECT_PATH=./" it was missing the backslash. Run commands 6 and 7 from folderx directory. I was running command 7 from [NDK_dir], instead of including [NDK_dir] in the command path. – Justin Bramel

1 Answers

1
votes

The easy fix is to move all three files to a subdirectory called jni. You don't need to export NDK_PROJECT_PATH, and your command will look like

<path-to/>ndk-build -C <path-to/>x/jni

If you need to avoid jni directory at any price, try

<path-to/>ndk-build NDK_PROJECT_PATH=<path-to/>x NDK_APPLICATION_MK=<path-to/>x/Application.mk APP_BUILD_SCRIPT=<path-to/>x/Android.mk

which is almost equivalent to

<path-to/>ndk-build -C <path-to/>x NDK_PROJECT_PATH=. NDK_APPLICATION_MK=Application.mk APP_BUILD_SCRIPT=Android.mk