Question

为了理解如何链接库，有人建议我查看以下的findALSA示例：

find_path(ALSA_INCLUDE_DIR NAMES asoundlib.h
          PATH_SUFFIXES alsa
          DOC "The ALSA (asound) include directory"
)

find_library(ALSA_LIBRARY NAMES asound
          DOC "The ALSA (asound) library"
)

# handle the QUIETLY and REQUIRED arguments and set ALSA_FOUND to TRUE if 
# all listed variables are TRUE
include("${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake")
FIND_PACKAGE_HANDLE_STANDARD_ARGS(ALSA DEFAULT_MSG ALSA_LIBRARY ALSA_INCLUDE_DIR)

if(ALSA_FOUND)
  set( ALSA_LIBRARIES ${ALSA_LIBRARY} )
  set( ALSA_INCLUDE_DIRS ${ALSA_INCLUDE_DIR} )
endif()

mark_as_advanced(ALSA_INCLUDE_DIR ALSA_LIBRARY)

我不明白的是：

if(ALSA_FOUND)
  set( ALSA_LIBRARIES ${ALSA_LIBRARY} )
  set( ALSA_INCLUDE_DIRS ${ALSA_INCLUDE_DIR} )
endif()

问题1：这是因为${ALSA_LIBRARY}和${ALSA_INCLUDE_DIR}只能指向单个文件/单个目录吗？

问题2：如果我想链接2个包含目录和2个库文件，有人可以告诉我如何重写示例吗？

假设我们有以下示例：

/alsa/dir1/asound1.h
/alsa/dir2/asound2.h
/alsa/lib/libasound1.a
/alsa/lib/libasound2.a

问题3：特别是FIND_PACKAGE_HANDLE_STANDARD_ARGS命令变成了什么？

非常感谢

Answer 1

是的，ASLI_LIBRARIES将结合这些。

2＆amp; 3：在find_package_handle_standard_args中仅定义程序包正常工作所需的内容。以下代码适用于所有需要的时间。

find_path(ALSA_INCLUDE_DIR1 NAMES asound1.h
          PATH_SUFFIXES alsa
          DOC "The ALSA (asound) include directory 1"
)

find_path(ALSA_INCLUDE_DIR2 NAMES asound2.h
          PATH_SUFFIXES alsa
          DOC "The ALSA (asound) include directory 2"
)

find_library(ALSA_LIBRARY2 NAMES asound1
          DOC "The ALSA (asound) library 1"
)

find_library(ALSA_LIBRARY2 NAMES asound2
          DOC "The ALSA (asound) library 2"
)

# handle the QUIETLY and REQUIRED arguments and set ALSA_FOUND to TRUE if 
# all listed variables are TRUE
include("${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake")
FIND_PACKAGE_HANDLE_STANDARD_ARGS(ALSA DEFAULT_MSG ALSA_LIBRARY1 ALSA_LIBRARY2 ALSA_INCLUDE_DIR1 ALSA_INCLUDE_DIR2)

if(ALSA_FOUND)
  set( ALSA_LIBRARIES ${ALSA_LIBRARY1} ${ALSA_LIBRARY2} )
  set( ALSA_INCLUDE_DIRS ${ALSA_INCLUDE_DIR1} ${ALSA_INCLUDE_DIR2} )
endif()

mark_as_advanced(ALSA_INCLUDE_DIR ALSA_LIBRARY)

Cmake：在findALSA.cmake示例中

1 个答案: