Android NDK Makefile、Android.mk 和 OCaml 的通用链接

Question

我正在使用 Android NDK 套件并拥有此 Android.mk 文件

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := ocaml
LOCAL_SRC_FILES := ocaml/hello.so
include $(PREBUILT_SHARED_LIBRARY)

# ocamlfind -toolchain android ocamlopt \
# -output-complete-obj -cclib -shared hello.ml -o hello.so

include $(CLEAR_VARS)
LOCAL_MODULE := simple_test
LOCAL_SRC_FILES := main.c
# This name had to be that created shared library
LOCAL_STATIC_LIBRARIES := ocaml
LOCAL_C_INCLUDES += /home/gar/.opam/android_coding/lib/ocaml

include $(BUILD_EXECUTABLE)

这编译成功并在 /home/gar/ocaml_on_android/libs/armeabi simple_test 和 hello.so.

中创建

然而，当我运行我的 Nexus 7 上的代码时，我得到

CANNOT LINK EXECUTABLE: library "/home/gar/ocaml_on_android/obj/local/armeabi/hello.so" not found

这意味着它在编译时没有正确链接。我如何编写这个 Android.mk 文件，以便所有内容都在一个可执行文件中静态编译？

编辑：评论后，使用这个：

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := ocaml
LOCAL_SRC_FILES := ocaml/hello.so
include $(PREBUILT_SHARED_LIBRARY)

# ocamlfind -toolchain android ocamlopt \
# -output-complete-obj -cclib -shared hello.ml -o hello.so

include $(CLEAR_VARS)
LOCAL_MODULE := simple_test
LOCAL_SRC_FILES := wrapper.c
# This name had to be that created shared library
LOCAL_SHARED_LIBRARIES := hello.so
LOCAL_C_INCLUDES += /home/gar/.opam/android_coding/lib/ocaml

include $(BUILD_EXECUTABLE)

并且在我的项目的 libs 文件夹中我仍然有两个对象，hello.so 和 simple_test 可执行文件，我希望只看到一个。对于 LOCAL_SHARED_LIBRARIES，不确定我是否需要输入模块名称、ocaml 或实际的共享对象 hello.so。这两种情况仍然在 libs 目录中产生了两个对象。

EDIT2：我的 Android.mk

现在有了这个

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := ocaml
LOCAL_SRC_FILES := ocaml/hello.so
include $(PREBUILT_SHARED_LIBRARY)

# ocamlfind -toolchain android ocamlopt \
# -output-complete-obj -cclib -shared hello.ml -o hello.so

include $(CLEAR_VARS)
LOCAL_MODULE := simple_test
LOCAL_SRC_FILES := wrapper.c
# This name had to be that created shared library
LOCAL_CFLAGS := -Wl,-Bstatic -static
LOCAL_SHARED_LIBRARIES := hello ocaml
LOCAL_C_INCLUDES += /home/gar/.opam/android_coding/lib/ocaml

include $(BUILD_EXECUTABLE)

当我检查创建的可执行文件时，我仍然看到它依赖于共享库

arm-linux-androideabi-readelf -d simple_test | grep NEEDED
 0x00000001 (NEEDED)                     Shared library: [/home/gar/asm_on_android/obj/local/armeabi/hello.so]
 0x00000001 (NEEDED)                     Shared library: [libstdc++.so]
 0x00000001 (NEEDED)                     Shared library: [libm.so]
 0x00000001 (NEEDED)                     Shared library: [libc.so]
 0x00000001 (NEEDED)                     Shared library: [libdl.so]

我还在设备上的 shell 上尝试了 LD_LIBRARY_PATH=. ./simple_test 命令，但出现此错误：

 LD_LIBRARY_PATH= . ./simple_test                                                                 
sh: ./simple_test[1]: syntax error: '\
                                       4' unexpected

Answer 1

这就是共享库的使用方式。您可以将 hello.so 推送到 simple_test 可执行文件附近的设备。

Android.mk 的语法应该是

LOCAL_SHARED_LIBRARIES := ocaml

在 shell 命令行上，使用

LD_LIBRARY_PATH=. ./simple_test

Answer 2

感谢 Alex 的帮助。

我决定暂时跳过 Android-NDK，直接使用 Makefile 解决方案，它确实有效。

这是 Makefile

cc := arm-linux-androideabi-gcc

sys_root := /Users/Edgar/.opam/4.02.3+32bit/lib/android-ndk/platforms/android-21/arch-arm

includes := /Users/Edgar/.opam/4.02.3+32bit/arm-linux-androideabi/include

ml_includes := /Users/Edgar/.opam/4.02.3+32bit/arm-linux-androideabi/lib/ocaml/

libs := /Users/Edgar/.opam/4.02.3+32bit/arm-linux-androideabi/lib

# Be sure to do export LD_LIBRARY_PATH=. and then run the program.
# Not sure how to do static linking yet, this will only dynamically
# link the program
complete: lib
    $(cc) --sysroot $(sys_root) -I$(includes) -L$(libs) \
    -pie -I$(ml_includes) hello.so main.c -o Finished

lib:
    ocamlfind -toolchain android ocamlopt -output-complete-obj \
    -cclib '-lm -shared' hello.ml -o hello.so

# This is a pure OCaml exectuable
exec:
    ocamlfind -toolchain android ocamlopt \
    -verbose -ccopt '-fPIE' -cclib '-pie' hello.ml -o hello

.PHONY: clean
clean:
    @rm -rf *.{cmi,cmt,o,cmx,so} Finished

...根据需要替换您的名称和路径。也把回购放在这里，https://github.com/fxfactorial/ocaml_on_android

Android NDK Makefile、Android.mk 和 OCaml 的通用链接

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