2017-05-27 90 views
0

我有我的CMakeList.txt中的2个库和1个可执行文件。我希望链接到可执行文件的所有内容。如何将库链接到cmake中的可执行文件?

cmake_minimum_required(VERSION 2.8) 

# Mark the language as C so that CMake doesn't try to test the C++ 
# cross-compiler's ability to compile a simple program because that will fail 
project(jsos C ASM) 
set(CMAKE_EXECUTABLE_OUTPUT_PATH "./build/") 

# We had to adjust the CMAKE_C_FLAGS variable in the toolchain file to make sure 
# the compiler would work with CMake's simple program compilation test. So unset 
# it explicitly before re-setting it correctly for our system 
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0") 
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g") 
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -nostartfiles") 

# Set the linker flags so that we use our "custom" linker script 
set(CMAKE_EXE_LINKER_FLAGS "-Wl,-T,${PROJECT_SOURCE_DIR}/etc/linker.ld") 

add_library(duktape STATIC 
    src/libs/duktape/duktape.c 
) 

add_library(fdlibm STATIC 
    src/libs/fdlibm/e_acos.c 
    src/libs/fdlibm/e_acosh.c 
    src/libs/fdlibm/e_asin.c 
    MORE FILES 
) 

add_executable(kernel 
    src/start.S 
    src/kernel.c 
    src/cstartup.c 
    src/cstubs.c 
    src/rpi-gpio.c 
    src/rpi-interrupts.c 
    src/rpi-armtimer.c 
    src/rpi-systimer.c 
) 

add_dependencies(kernel fdlibm duktape) 

target_link_libraries(kernel fdlibm duktape) 

add_custom_command(
    TARGET kernel POST_BUILD 
    COMMAND ${CMAKE_OBJCOPY} ./kernel${CMAKE_EXECUTABLE_SUFFIX} -O binary ./kernel.img 
    WORKING_DIRECTORY ${CMAKE_BINARY_DIR} 
    COMMENT "Convert the ELF output file to a binary image" 
) 

在那一刻,我链接这些我一起得到像一堆错误:

[100%] Linking C executable kernel 
libduktape.a(duktape.c.obj): In function `duk_double_trunc_towards_zero': 
src/libs/duktape/duktape.c:12102: undefined reference to `fabs' 
src/libs/duktape/duktape.c:12102: undefined reference to `floor' 

fabsfloorfdlibmduk_double_trunc_towards_zeroduktape库中,因此似乎链接OK。我究竟做错了什么?

+2

尝试在'target_link_libraries'调用中交换库的顺序。 – arrowd

+0

@arrowd作出回答,以便接受它。这是对的 – Justin808

回答

1

在你的声明:

target_link_libraries(kernel fdlibm duktape) 

要解决从提供库的有序列表中搜索(fdlibm duktape在这种情况下)这样的外部referece符号:

  • 从开始图书馆被链接;
  • 在它右侧的库上搜索符号;

在你的情况,解决的duktape外部符号(其中一些是fdlibm)时,fdlibm甚至没有用于该搜索,并duktape需要的符号都没有发现。只需在之后放置fdlibm ,duktape将让符号被找到。

例如,如果您取决于duktape定义的一些符号,而且周围的其他方法有一个fdlibm,你应该使用:

target_link_libraries(kernel fdlibm duktape fdlibm) 

使符号总是解决。

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