title: ndk build_static_library make: Nothing to be done for `all'
body: <p>I meet a problem when I build the libjpeg on android in eclipse. The jni contains Android.mk as follow:</p>
  
  <pre><code>    LOCAL_PATH := $(call my-dir)
      include $(CLEAR_VARS)
      LOCAL_MODULE    := hello-jni
      LOCAL_SRC_FILES := hello-jni.c
      #LOCAL_C_INCLUDES := $(LOCAL_PATH)/jpeg8d-master
      #LOCAL_STATIC_LIBRARIES := libjpeg
      include $(BUILD_STATIC_LIBRARY)
      #include $(LOCAL_PATH)/jpeg8d-master/Android.mk
  </code></pre>
  
  <p>The jpeg8d is the source code I download from <a href="https://github.com/folecr/jpeg8d" rel="nofollow">github</a>. The android.mk  </p>
  
  <pre><code>LOCAL_PATH:= $(call my-dir)
  # ------------------------------------------------------------------
  # Static library for Cocos
  # ------------------------------------------------------------------
  include $(CLEAR_VARS)
  LOCAL_MODULE := cocos_jpeg_static
  LOCAL_MODULE_FILENAME := libjpeg
  LOCAL_SRC_FILES := \
      jcapimin.c jcapistd.c jccoefct.c jccolor.c jcdctmgr.c jchuff.c \
      jcinit.c jcmainct.c jcmarker.c jcmaster.c jcomapi.c jcparam.c \
      jcprepct.c jcsample.c jctrans.c jdapimin.c jdapistd.c \
      jdatadst.c jdatasrc.c jdcoefct.c jdcolor.c jddctmgr.c jdhuff.c \
      jdinput.c jdmainct.c jdmarker.c jdmaster.c jdmerge.c \
      jdpostct.c jdsample.c jdtrans.c jerror.c jfdctflt.c jfdctfst.c \
      jfdctint.c jidctflt.c jidctfst.c jidctint.c jquant1.c \
      jquant2.c jutils.c jmemmgr.c jcarith.c jdarith.c jaricom.c
  
  # Use the no backing store memory manager provided by
  # libjpeg. See install.txt
  LOCAL_SRC_FILES += \
      jmemnobs.c
  
  LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)
  include $(BUILD_STATIC_LIBRARY)
  </code></pre>
  
  <p>ndk-build give the tips :</p>
  
  <blockquote>
    <p>make: Nothing to be done for `all'.</p>
  </blockquote>
  
  <p>But if I Set the jpeg8d Android.mk   <code>BUILD_SHARED_LIBRARY</code>,I get the <code>libjpeg.so</code>.
  I don't know why. Can anyone help me ?</p>