I have a similar question to that posted here:
Android NDK: why ndk-build doesn't generate .so file and a new libs folder in Eclipse?
...though I am running Windows 7, not Mac os. Essentially the ndk-build command is run, gives no error but doesn't create an .so file (also, since I'm on windows this should create a .dll and not an .so?). I tried running the command from the root, jni, src folders etc. but got the same result; cmd just returns to the prompter after a few seconds. I ran it again from the jni folder with NDK_LOG=1 parameter to see what was happening. Here is a portion of the transcript of the log results after running ndk-build in the jni folder (after it successfully identified the platform, etc.)...
Android NDK: Looking for jni/Android.mk in /workspace/NdkFooActivity/jni
Android NDK: Looking for jni/Android.mk in /workspace/NdkFooActivity
Android NDK: Found it !
Android NDK: Found project path: /workspace/NdkFooActivity
Android NDK: Ouput path: /workspace/NdkFooActivity/obj
Android NDK: Parsing /cygdrive/c/android-ndk-r8/build/core/default-application.mk
Android NDK: Found APP_PLATFORM=android-15 in /workspace/NdkFooActivity/project.properties
Android NDK: Application local targets unknown platform 'android-15'
Android NDK: Switching to android-14
Android NDK: Using build script /workspace/NdkFooActivity/jni/Android.mk
Android NDK: Application 'local' is not debuggable
Android NDK: Selecting release optimization mode (app is not debuggable)
Android NDK: Adding import directory: /cygdrive/c/android-ndk-r8/sources
Android NDK: Building application 'local' for ABI 'armeabi'
Android NDK: Using target toolchain 'arm-linux-androideabi-4.4.3' for 'armeabi' ABI
Android NDK: Looking for imported module with tag 'cxx-stl/system'
Android NDK: Probing /cygdrive/c/android-ndk-r8/sources/cxx-stl/system/Android.mk
Android NDK: Found in /cygdrive/c/android-ndk-r8/sources/cxx-stl/system
Android NDK: Cygwin dependency file conversion script:
...after which point it just runs the script mentioned in the last line, then terminates. Any ideas? Thanks!
3 Answers 3
Set up a builder. Refer to following article for how to do that:
http://maxters.net/2011/02/android-ndk-builder-for-eclipse-in-windows/
There is a "small" change beginning NDK r8 – Cygwin is not necessary anymore and I had a trouble when building native libraries with Cygwin and NDK r8 – there was some error message about cxx-stl...
Almost everything in the link above is OK, but leave Arguments in the Main tab blank and change Location to:
${env_var:ANDROID_NDK_ROOT}/ndk-build.cmd
I use system variable path ANDROID_NDK_ROOT, but you can provide a full path to the ndk-build.cmd.
Also, there is no need to set any variable in the Environment tab.
Set up your builder this way and you will be fine.
Just a note, Android is built on the top of the Linux OS, so even if you are on Windows you will get Linux libraries with .so extension.
Comments
Following link was instructive but missing a detail if you are configuring NDK support in Eclipse after CDT it already depricated (summer of 2017 already).
http://maxters.net/2011/02/android-ndk-builder-for-eclipse-in-windows/
Where you need to configure your external builder Location, instead of pointing to cygwin\bin\bash.exe and adding as Argument your ndk-build.cmd location this is what worked for me on Windows 7 and 10.
In "Edit Configuration" dialog for external builder do following: - for Location -> specify where your "ndk-build.cmd" is. i.e "D:\Android\NDK\ndk-build.cmd" - for Arguments -> just specify "all"
Comments
The NDK build system relies on wildcards to find the sources to compile. If you have a path wrong somewhere, it will find no sources and do nothing. Check Android.mk very carefully. More can't be said unless you post Android.mk and a description of the source tree.