Android NDK，两个静态库和链接

Question

我最开始创建的是共享库，但我认为创建一个共享库和其余静态库会更有效率。当所有库都是共享的时候，编译和链接都没问题，但是当转为静态库后，我在链接时遇到了“未定义引用”的问题。

编辑： 我在一个 Android.mk 中构建所有库。

Android.mk:

MY_LOCAL_PATH := $(call my-dir)
MY_LOCAL_CFLAGS := -DDEBUG

TARGET_PLATFORM := 'android-4'

LOCAL_PATH := $(MY_LOCAL_PATH)/../../Base

include $(CLEAR_VARS)

LOCAL_MODULE     := Base
LOCAL_SRC_FILES  := <Base src files>
include $(BUILD_STATIC_LIBRARY)

MY_LOCAL_STATIC_LIBRARIES := Base

MY_LOCAL_C_INCLUDES := $(MY_LOCAL_PATH)/../../Base

LOCAL_PATH := $(MY_LOCAL_PATH)/../../Framework

include $(CLEAR_VARS)

LOCAL_MODULE     := Framework
LOCAL_C_INCLUDES := $(MY_LOCAL_C_INCLUDES)
LOCAL_SRC_FILES  := <Framework src files>
LOCAL_CFLAGS := $(MY_LOCAL_CFLAGS)

include $(BUILD_STATIC_LIBRARY)

MY_LOCAL_STATIC_LIBRARIES += Framework

MY_LOCAL_C_INCLUDES += $(MY_LOCAL_PATH)/../../Framework

LOCAL_PATH := $(MY_LOCAL_PATH)/Graphics

include $(CLEAR_VARS)

LOCAL_MODULE    := Graphics
LOCAL_SRC_FILES := <Graphics src files>
LOCAL_EXPORT_LDLIBS := -lGLESv1_CM
LOCAL_CFLAGS := $(MY_LOCAL_CFLAGS)
LOCAL_C_INCLUDES := $(MY_LOCAL_C_INCLUDES)

include $(BUILD_STATIC_LIBRARY)

MY_LOCAL_STATIC_LIBRARIES += Graphics

MY_LOCAL_C_INCLUDES += $(MY_LOCAL_PATH)/Graphics

LOCAL_PATH := $(MY_LOCAL_PATH)/Platform

include $(CLEAR_VARS)

LOCAL_MODULE := Platform
LOCAL_SRC_FILES := <Platform src files>
LOCAL_CFLAGS := $(MY_LOCAL_CFLAGS)
LOCAL_C_INCLUDES := $(MY_LOCAL_C_INCLUDES)

include $(BUILD_STATIC_LIBRARY)

MY_LOCAL_STATIC_LIBRARIES += Platform

MY_LOCAL_C_INCLUDES += $(MY_LOCAL_PATH)/Platform

LOCAL_PATH := $(MY_LOCAL_PATH)

include $(CLEAR_VARS)

LOCAL_MODULE    := Final
LOCAL_SRC_FILES := <Final src files>
LOCAL_STATIC_LIBRARIES := $(MY_LOCAL_STATIC_LIBRARIES)
LOCAL_LDLIBS    := -llog
LOCAL_CFLAGS := $(MY_LOCAL_CFLAGS)
LOCAL_C_INCLUDES := $(MY_LOCAL_C_INCLUDES)

include $(BUILD_SHARED_LIBRARY)

ndk-build V=1 -B 的最后一行：

SharedLibrary  : libFinal.so
/Users/robbie/Library/Frameworks/Android-NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt/darwin-x86/bin/arm-linux-androideabi-g++ -Wl,-soname,libFinal.so -shared --sysroot=/Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm <object files>   /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libBase.a /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libFramework.a /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libGraphics.a /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libPlatform.a /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libstdc++.a  /Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm/usr/lib/libc.so /Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm/usr/lib/libstdc++.so /Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm/usr/lib/libm.so   -Wl,--no-undefined -Wl,-z,noexecstack -L/Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm/usr/lib -llog -lGLESv1_CM -lstdc++ -Wl,-rpath-link=/Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm/usr/lib -lsupc++ -o /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libFinal.so
/Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libPlatform.a(ATexture.o): In function `ATexture':
/Users/robbie/Documents/Apps/Revolution/Android/jni/SpinTap/ATexture.cpp:9: undefined reference to `TextureRenderer::TextureRenderer(unsigned int)'
/Users/robbie/Documents/Apps/Revolution/Android/jni/SpinTap/ATexture.cpp:9: undefined reference to `TextureRenderer::TextureRenderer(unsigned int)'

编辑2： TextureRenderer在Graphics中，并已包含。

有人知道为什么它可能不起作用以及如何修复吗？

- NebulaFox

---

除了需要键入更多的System.loadLibrary()之外，一个共享库是否比多个共享库有任何好处？ - NebulaFox

我没有遇到你的问题，只是不知道如何生成静态库进行链接。感谢提供示例。 - Gamma Draconis

Answer 1

在我看来，这似乎是一个链接顺序的问题。

你的命令行是：

arm-linux-androideabi-g++ -Wl,-soname,libFinal.so -shared \
  libBase.a libFramework.a libGraphics.a libPlatform.a -o libFinal.so

而且出现了错误

libPlatform.a(ATexture.o): In function `ATexture':
ATexture.cpp:9: undefined reference to `TextureRenderer'
ATexture.cpp:9: undefined reference to `TextureRenderer'

TextureRenderer在Graphics库中，但是在命令行上libGraphics出现在libPlatform之前。g++将按照给定的顺序在命令行上搜索每个库，并加载解析外部引用的函数。它会读取一次libGraphics，加载解析外部引用的函数，然后转到libPlatform。

尝试将LOCAL_STATIC_LIBRARIES := $(MY_LOCAL_STATIC_LIBRARIES)更改为LOCAL_STATIC_LIBRARIES := Platform Graphics Framework Base，看看是否能够解决问题。

- richq

Answer 2

在你的Android.mk文件中，请确保使用正确的调用引用静态库：

LOCAL_STATIC_LIBRARIES := mystaticlibproj

在调用$(BUILD_SHARED_LIBRARY)之前，需要进行以下操作。

然后，在文件末尾，调用导入静态库模块。

$(call import-module, mystaticlibproj)

如果您仍然遇到问题，请发布详细的构建日志（ndk-build V=1 -B）和您的Android.mk文件

- levis501

---

我应该提到我将所有库编译在一个Android.mk中。 - NebulaFox

首先，我会仔细检查TextureRenderer是否确实在libGraphics.a中，虽然它很可能是。使用/Users/robbie/Library/Frameworks/Android-NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt/darwin-x86/bin/arm-linux-androideabi-nm来转储库中的符号。 - levis501