ndk-build 找不到库

Question

我正在尝试使用 ndk-build 构建此示例项目，但由于某种原因它找不到库。这是我收到的错误消息：

build-binary.mk:688：Android NDK：模块 fastcvFeatDetect 依赖于未定义的模块： 登录 GLESv2

我对 ndk 的了解不够，不知道如何检查这些库是否可用以及我是否正确地指向了它们的路径。

顶层有这个主make文件：

# An Android.mk file must begin with the definition of the LOCAL_PATH variable.
# It is used to locate source files in the development tree. In this example,
# the macro function 'my-dir', provided by the build system, is used to return
# the path of the current directory (i.e. the directory containing the
# Android.mk file itself). 
#
LOCAL_PATH := $(call my-dir) 

JNI_DIR := $(LOCAL_PATH)
UTILS_DIR := $(LOCAL_PATH)/utils

# The function "$(call all-subdir-makefiles)" returns a list of Android.mk 
# files located in all sub-directories of the current 'my-dir' path.
# This function can be used to provide deep-nested source directory
# hierarchies to the build system.
#
include $(call all-subdir-makefiles)

随后是子目录中的这些 make 文件：

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS)
LOCAL_PRELINK_MODULE:= false

# This variable determines the OpenGL ES API version to use:
# If set to true, OpenGL ES 1.1 is used, otherwise OpenGL ES 2.0.

USE_OPENGL_ES_1_1 := false

# Set OpenGL ES version-specific settings.

ifeq ($(USE_OPENGL_ES_1_1), true)
    OPENGLES_LIB  := -lGLESv1_CM
    OPENGLES_DEF  := -DUSE_OPENGL_ES_1_1
else
    OPENGLES_LIB  := -lGLESv2
    OPENGLES_DEF  := -DUSE_OPENGL_ES_2_0
endif

# An optional set of compiler flags that will be passed when building
# C ***AND*** C++ source files.
#
# NOTE: flag "-Wno-write-strings" removes warning about deprecated conversion
#       from string constant to 'char*'

LOCAL_CFLAGS := -Wno-write-strings $(OPENGLES_DEF)

# The list of additional linker flags to be used when building your
# module. This is useful to pass the name of specific system libraries
# with the "-l" prefix.

LOCAL_LDLIBS := \
     -llog $(OPENGLES_LIB)
LOCAL_LDFLAGS:= -Wl,--no-fix-cortex-a8

LOCAL_MODULE    := libfastcvFeatDetect
LOCAL_CFLAGS    := -Werror
LOCAL_SRC_FILES := ../About.cpp Corner.cpp

LOCAL_STATIC_LIBRARIES := libfastcv libfastcvUtils
LOCAL_SHARED_LIBRARIES := liblog
LOCAL_C_INCLUDES += $(JNI_DIR)/fastcv
LOCAL_C_INCLUDES += $(JNI_DIR)

LOCAL_MODULE_OWNER := qcom
LOCAL_PROPRIETARY_MODULE := true

include $(BUILD_SHARED_LIBRARY)

我尝试根据谷歌搜索更改一些内容，但到目前为止没有任何效果。有人有什么建议吗？

Answer 1

LOCAL_PRELINK_MODULE:= false

这不是 NDK 示例。这是平台代码。它是使用 AOSP 构建系统而不是 NDK 构建的。有关更多信息，请参阅https://source.android.com/setup/build/building。

如果您正在尝试查找 NDK 示例，请参阅 https://github.com/googlesamples/android-ndk。

如果您确实需要使用 NDK 构建这个非 NDK 项目，请继续阅读。

---

查找$NDK/build 中的错误消息通常是查找更多信息的好方法：

$(call __ndk_warning,Module $(LOCAL_MODULE) depends on undefined modules: $(undefined_libs))

# https://github.com/android-ndk/ndk/issues/208
# ndk-build didn't used to fail the build for a missing dependency. This
# seems to have always been the behavior, so there's a good chance that
# there are builds out there that depend on this behavior (as of right now,
# anything using libc++ on ARM has this problem because of libunwind).
#
# By default we will abort in this situation because this is so completely
# broken. A user may define APP_ALLOW_MISSING_DEPS to "true" in their
# Application.mk or on the command line to revert to the old, broken
# behavior.
ifneq ($(APP_ALLOW_MISSING_DEPS),true)
    $(call __ndk_error,Aborting (set APP_ALLOW_MISSING_DEPS=true to allow missing dependencies))
endif

这曾经被默默地忽略，现在它是一个错误。它指出了以下错误：

LOCAL_SHARED_LIBRARIES := liblog

这条线什么也不做。删除它。系统库与LOCAL_LDLIBS 链接，而不是LOCAL_SHARED_LIRBARIES。其他地方也会有类似的行导致 GLESv2 出现错误。