c++ - cmake:链接 STATIC IMPORTED 库失败

Question

我有供应商提供的静态库。

我已将其添加为STATIC IMPORTED 库目标，并在目标上设置属性:

add_library(
    lime_api 
        STATIC 
        IMPORTED
    )

set_target_properties(
    lime_api 
        PROPERTIES 
        IMPORTED_LOCATION "${CMAKE_CURRENT_LIST_DIR}/trading/limeTradingApi.a"
    )

# users include "api/trading/limeTradingApi.h"
set_target_properties(
    lime_api 
        PROPERTIES
        INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_CURRENT_LIST_DIR}/.."
    )

在我的源代码树的其他地方，我尝试链接到 lime_api，但出现错误:

/usr/bin/ld: cannot find -llime_api

我的源代码树是这样的:

src
|
+--- api
|    | 
|    +--- trading
|    |       - limeTradingApi.a
|    |       - limeTradingApi.h
|    |
|    +--- examples
|         |
|         +--- trading
|
+--- order
     |
     +--- example

奇怪的是，有一个供应商提供的示例链接到这个库，并且工作正常:

api/examples/trading/CMakeLists.txt:

add_executable       (trading_demo exampleClient.cc)
target_link_libraries(trading_demo lime_api)           <-- this works

但是，当我尝试链接到我自己的包含 lime_api 的库时，我收到链接器错误。

顺序/CMakeLists.txt:

add_library(
        order
            STATIC
            ${SRCS}
        )
target_link_libraries(order lime_api)                  <-- this doesn't work

命令/示例/CMakeLists.txt:

add_executable       (order_example main.cpp)
target_link_libraries(order_example order)

问题:

为什么 CMake “转换” 链接目标 lime_api 为我的可执行文件的 -llimeTradingApi.a？

Answer 1

我怀疑您遇到了 IMPORTED 库目标的可见性问题。根据documentation :

An IMPORTED library target references a library file located outside the
project. ... The target name has scope in the directory in which it is
created and below, but the GLOBAL option extends visibility.

这就是为什么正确的库路径用于内部 trading_demo 目标，而不用于外部 order_example 目标。要解决此问题，添加 GLOBAL 选项应该就足够了:

add_library(lime_api STATIC IMPORTED GLOBAL)