警告:.../Android.mk:链接器标志中的非系统库

Question

跑步时我收到了这个警告$ANDROID_NDK_ROOT/ndk-build.在Android.mk下面.

$ $ANDROID_NDK_ROOT/ndk-build 

WARNING:/Users/jwalton/Android-CryptoPP/jni/Android.mk:prng:
    non-system libraries in linker flags: -lcryptopp -lstlport_shared    
    This is likely to result in incorrect builds. Try using LOCAL_STATIC_LIBRARIES    
    or LOCAL_SHARED_LIBRARIES instead to list the library dependencies of the
    current module
...

但是,当我按照说明并-lcryptopp -lstlport_shared从中删除时LOCAL_LDLIBS,我会收到与符号相关的链接错误libstlport_shared.so.Android.mk文件后面显示了错误示例.

怎么样,究竟,并ndk-build要Android.mk设置？

我为什么要添加$(STLPORT_INCL)到LOCAL_C_INCLUDES,并$(STLPORT_LIB)以LOCAL_LDFLAGS？为什么APP_STL := stlport_shared 不建立在STL正确开箱？

---

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

TARGET_ARCH_ABI := armeabi
TARGET_ABI      := android-9-armeabi

CRYPTOPP_INCL   := /usr/local/cryptopp-android-9/include
CRYPTOPP_LIB    := /usr/local/cryptopp-android-9/lib

STLPORT_INCL    := /opt/android-ndk-r9/sources/cxx-stl/stlport/stlport
STLPORT_LIB     := /opt/android-ndk-r9/sources/cxx-stl/stlport/libs/armeabi

APP_STL         := stlport_shared
APP_MODULES     := stlport_shared cryptopp

LOCAL_CPP_FEATURES := rtti exceptions

LOCAL_C_INCLUDES := $(CRYPTOPP_INCL) $(CRYPTOPP_INCL)/cryptopp $(STLPORT_INCL)

LOCAL_LDFLAGS  := -L $(CRYPTOPP_LIB) -L $(STLPORT_LIB)
LOCAL_LDLIBS   := -lcryptopp -lstlport_shared -llog -landroid
# LOCAL_LDLIBS   := -llog -landroid
# LOCAL_SHARED_LIBRARIES := -lcryptopp -lstlport_shared

LOCAL_MODULE    := prng
LOCAL_SRC_FILES := libprng.cpp

include $(BUILD_SHARED_LIBRARY)

---

以下是尝试通过删除我的本地库来遵循建议时的错误示例LOCAL_LDLIBS:

$ $ANDROID_NDK_ROOT/ndk-build 
Android NDK: WARNING: APP_PLATFORM android-14 is larger than android:minSdkVersion 9 in /Users/jwalton/Android-CryptoPP/AndroidManifest.xml    
Gdbserver      : [arm-linux-androideabi-4.6] libs/armeabi/gdbserver
Gdbsetup       : libs/armeabi/gdb.setup
Compile++ thumb  : prng <= libprng.cpp
SharedLibrary  : libprng.so
/opt/android-ndk-r9/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: /Users/jwalton/Android-CryptoPP/obj/local/armeabi/objs-debug/prng/libprng.o: in function std::__node_alloc::allocate(unsigned int&):/opt/android-ndk-r9/sources/cxx-stl/stlport/stlport/stl/_alloc.h:158: error: undefined reference to 'std::__node_alloc::_M_allocate(unsigned int&)'
/opt/android-ndk-r9/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: /Users/jwalton/Android-CryptoPP/obj/local/armeabi/objs-debug/prng/libprng.o: in function std::__node_alloc::deallocate(void*, unsigned int):/opt/android-ndk-r9/sources/cxx-stl/stlport/stlport/stl/_alloc.h:161: error: undefined reference to 'std::__node_alloc::_M_deallocate(void*, unsigned int)'
/opt/android-ndk-r9/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: /Users/jwalton/Android-CryptoPP/obj/local/armeabi/objs-debug/prng/libprng.o: in function std::ios_base::_M_check_exception_mask():/opt/android-ndk-r9/sources/cxx-stl/stlport/stlport/stl/_ios_base.h:193: error: undefined reference to 'std::ios_base::_M_throw_failure()'

...

Answer 1

我将"链接器标志中的非系统库"消息解释为您没有使用默认系统库(in usr/lib)的警告,这可能非常好,但也可能导致错误(不同库版本之间不兼容).这个警告错误是否完全取决于你.

然后,关于你试图解决它的方式,我认为你错误地使用LOCAL_SHARED_LIBRARIES了NDK 的变量.

我在这里粘贴了一个Android.mk使用Assimp的文件中的样本

#------------------------------------------------------------------ Assimp
include $(CLEAR_VARS)

LOCAL_MODULE := Assimp
LOCAL_EXPORT_C_INCLUDES := $(GENERATED_INCLUDE_PATH)/assimp/include
LOCAL_SRC_FILES := $(GENERATED_PATH)/assimp/lib/libassimp.a

include $(PREBUILT_STATIC_LIBRARY)

...

LOCAL_STATIC_LIBRARIES := \
Assimp \
<Your other libs here>

如您所见,我声明了LOCAL_MODULE一个自定义名称,设置了一些变量,然后包含PREBUILT_STATIC_LIBRARY告诉NDK使用此lib 的脚本.

然后在LOCAL_STATIC_LIBRARIES我列出我使用的库和模块名称,而不是像你在这里做的链接器标志.

在您的情况下,我相信您应该执行以下操作,例如对于stl

include $(CLEAR_VARS)

LOCAL_MODULE := STLPortShared
LOCAL_EXPORT_C_INCLUDES := <path to stlport includes>
LOCAL_SRC_FILES := <path to stlport library>

include $(PREBUILT_SHARED_LIBRARY)

...
#Notice the name, identical to the one specified for LOCAL_MODULE
LOCAL_SHARED_LIBRARIES = STLPortShared 

我认为应该这样做.当然,为每个导致故障的库重复该过程,并且不要忘记include(CLEAR_VARS)每个lib规范之间的过程.