Android原生共享库安装路径

Question

我正在努力让原生 Android 应用程序正确链接到在同一 AOSP 树中构建的自定义共享对象。

我有一个用

构建的共享对象

LOCAL_SRC_FILES += \
   src/libscanengine.c

LOCAL_C_INCLUDES += $(LOCAL_PATH) 
LOCAL_C_INCLUDES += $(LOCAL_PATH)/include/
LOCAL_C_INCLUDES += kernel/include/

#every module depending on us will 
#automagically have this included
LOCAL_EXPORT_C_INCLUDES := \
  $(LOCAL_PATH)/include

LOCAL_MODULE_TAGS := optional
LOCAL_MODULE := libscanengine 
LOCAL_PRELINK_MODULE := false

include $(BUILD_SHARED_LIBRARY)

它作为 mm 命令调用构建和安装

build/core/dynamic_binary.mk:141: warning: overriding commands for target `.so'
build/core/dynamic_binary.mk:118: warning: ignoring old commands for target `.so'
build/core/shared_library.mk:54: warning: overriding commands for target `.so'
build/core/dynamic_binary.mk:141: warning: ignoring old commands for target `.so'
No private recovery resources for TARGET_DEVICE X
No recovery.fstab for TARGET_DEVICE X
make: Circular .so <- .so dependency dropped.
make: Circular .so <- out/target/product/X/symbols/system/lib/libscanengine dependency dropped.
make: Circular .so <- .so dependency dropped.
target Non-prelinked: libscanengine (out/target/product/X/symbols/system/lib/libscanengine)
target Strip: libscanengine (out/target/product/X/obj/lib/libscanengine)
Install: out/target/product/X/system/lib/libscanengine.so

一旦我尝试使用以下 Android.mk 构建与新创建的 .so 链接的本机应用程序

LOCAL_SRC_FILES := \
    src/mores.c

LOCAL_C_INCLUDES += \
    $(LOCAL_PATH) 
LOCAL_C_INCLUDES += \
    $(LOCAL_PATH)/include/

#not working: commented out
#LOCAL_LDLIBS += \
    -lscanengine
#LOCAL_C_FLAGS += \
    -L../../out/target/product/X/system/lib/

LOCAL_SHARED_LIBRARIES := \
    libscanengine

LOCAL_MODULE_TAGS := optional
LOCAL_MODULE := mores

include $(BUILD_EXECUTABLE)

我明白了：

make: *** No rule to make target `out/target/product/X/obj/lib/libscanengine.so', needed by `out/target/product/X/obj/EXECUTABLES/mores_intermediates/LINKED/mores'.  Stop.

我注意到两件事：共享库作为 libscanengine 安装在 X/out/lib 下，而不是本地应用程序所需的 libscanenegine.so。

我每次都必须手动复制 .so，这很愚蠢，因为所有这些都应该由 Android 构建系统以某种方式处理。

此外，LOCAL_EXPORT_C_INCLUDES 指令不起作用。它仅适用于 PREBUILT_SHARED_OBJECTS 吗？

Android 版本是 2.3，不涉及 Java，一切都在 AOSP 下构建。

谢谢
j

Answer 1

LOCAL_C_FLAGS += \
    -L../../out/target/product/X/system/lib/

不起作用，因为它应该读取

LOCAL_LDFLAGS += \
    -Lout/target/product/X/system/lib

或

LOCAL_LDFLAGS += \
    -L$(LOCAL_PATH)/out/target/product/X/system/lib

但这并不能解释为什么 LOCAL_SHARED_LIBRARIES 不起作用。你使用什么命令来构建？

Answer 2

虽然不是一个好的解决方案，但如果无法通过 AOSP 隐式找到 libscanengine 目标，那么您始终可以手动包含它，就像这样。

include $(AOSP_ROOT)/PATH/TO/libscanengine/Android.mk

关于共享对象无法正确构建的原因，一个骇人的解决方案是在 Android.mk 中直接在引用它的共享对象之后提供一个静态对象。例如，这是我从现有的 jpeg 端口改编而来的。我想要的是一个共享库，我可以在单独的编译步骤中使用它，但除非有什么需要，否则它不会被构建。

$(call my-dir)
include $(CLEAR_VARS)

LOCAL_ARM_MODE := arm

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 \
    jcphuff.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 jdphuff.c \
    jdpostct.c jdsample.c jdtrans.c jerror.c jfdctflt.c jfdctfst.c \
    jfdctint.c jidctflt.c jidctred.c jquant1.c \
    jquant2.c jutils.c jmemmgr.c \
    jmem-android.c

# the assembler is only for the ARM version, don't break the Linux sim
ifneq ($(TARGET_ARCH),arm)
ANDROID_JPEG_NO_ASSEMBLER := true
endif

# temp fix until we understand why this broke cnn.com
#ANDROID_JPEG_NO_ASSEMBLER := true

ifeq ($(strip $(ANDROID_JPEG_NO_ASSEMBLER)),true)
LOCAL_SRC_FILES += jidctint.c jidctfst.c
else
LOCAL_SRC_FILES += jidctint.c jidctfst.S
endif

LOCAL_CFLAGS += -I"$(LOCAL_PATH)/./include" -DAVOID_TABLES
LOCAL_CFLAGS += -O3 -fstrict-aliasing -fprefetch-loop-arrays
#LOCAL_CFLAGS += -march=armv6j

LOCAL_MODULE:= jpeg

include $(BUILD_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := jpeg2
LOCAL_STATIC_LIBRARIES := jpeg

include $(BUILD_SHARED_LIBRARY)

虽然这些都不是真正的解决方案，因为它们不能解决问题背后的根本原因，但它们可能会帮助你，就像他们对我所做的那样，让工作快速、自动地工作。