opencv - 如何在同一个 Android.mk 中编译两个不同的库，将其中一个链接到另一个

Question

我有 2 个不同库的源代码，FooMain 和 FooSecondary。 FooSecondary 被FooMain 使用，所以makefile 必须先编译FooSecondary，再编译FooMain，再将FooSecondary 链接到FooMain。

我的 Android.mk 是:

LOCAL_PATH:= $(call my-dir)# Foo Secondary lib:# Clear varsinclude $(CLEAR_VARS)# Target BuildLOCAL_ARM_MODE := arm   # Library Name          LOCAL_MODULE := FooSecondary        # Set All SRC_FILES Together            SRC_FILES := $(wildcard $(LOCAL_PATH)/FooSecondary/src/*.c)SRC_FILES := $(SRC_FILES:$(LOCAL_PATH)/%=%)     LOCAL_SRC_FILES = $(SRC_FILES)# Enable Log supportLOCAL_LDLIBS = -llog    # C   Flags - Max optimization              LOCAL_CFLAGS := -O3 -mno-thumb# C++ Flags - Max optimization          LOCAL_CPPFLAGS := -O3 -mno-thumb# Compile as Shared Library     include $(BUILD_SHARED_LIBRARY)     # Foo Secondary lib:# Clear varsinclude $(CLEAR_VARS)# Include OpenCVinclude 3rdparty/OpenCV-2.4.3-rc-android-sdk/sdk/native/jni/OpenCV.mk# Target BuildLOCAL_ARM_MODE := arm   # Library Name          LOCAL_MODULE := FooMain     # Set All SRC_FILES Together            SRC_FILES := $(wildcard $(LOCAL_PATH)/FooMain/src/*.cpp)SRC_FILES := $(SRC_FILES:$(LOCAL_PATH)/%=%)     LOCAL_SRC_FILES = $(SRC_FILES)LOCAL_SHARED_LIBRARIES := libFooSecondaryLOCAL_LDLIBS := -L$(LOCAL_PATH)/../libs/armeabi LOCAL_LDLIBS += -lz -lm -ldl -lGLESv2 -lEGL -llog -lFooSecondaryLOCAL_CFLAGS := -O2 -mno-thumb -Wno-write-stringsLOCAL_CPPFLAGS := -O2 -mno-thumb -Wno-write-strings# Compile as Shared Library     include $(BUILD_SHARED_LIBRARY) 

And my Application.mk is:

APP_CPPFLAGS := -frtti -fexceptionsAPP_STL := gnustl_staticAPP_ABI := armeabi-v7a

But, when I compile Android.mk using ndk-build I get the next Error:

Compile arm    : libFooSecondary <= *.c
SharedLibrary  : libFooSecondary.so
Install        : libFooSecondary.so => libs/armeabi-v7a/libFooSecondary.so
SharedLibrary  : libFooMain.so

/home/user/android-ndk-r8/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86/bin/../lib/gcc/arm-linux-androideabi/4.4.3/../../../../arm-linux-androideabi/bin/ld: cannot find -lFooSecondary

collect2: ld returned 1 exit status
make: *** [obj/local/armeabi-v7a/libFooMain.so] Error 1

为什么正确编译安装了libFooSecondary.so却找不到？

此外，如果 LOCAL_MODULE 名称更改，例如，第一个是 LOCAL_MODULE := zname，第二个是 LOCAL_MODULE := aname，则先编译第二个，我不知道为什么。

Answer 1

您的 Android.mk 看起来很奇怪。它是否在某处分配了 LOCAL_PATH？无需将 LOCAL_CPPFLAGS 分配给重复的 LOCAL_CFLAGS，因为 ndk-build 将两组标志都放在 C++ 命令行上。

要更好地了解 NDK 如何解释您的 Application.mk 和 Android.mk，您可以运行

ndk-build V=1

这将回显所有已执行的命令，包括编译和链接，以及 NDK 构建分配的所有参数。