在CMake中,CHECK_INCLUDE_FILE_CXX如何工作？

Question

以下代码不打印任何内容

CHECK_INCLUDE_FILE_CXX(glog/logging.h GLOG_INCLUDE)
IF(GLOG_INCLUDE)
   MESSAGE("YY")
ENDIF(GLOG_INCLUDE)

但我有以下环境变量集:

export CPLUS_INCLUDE_PATH=/usr/local/include

并且,"ls /usr/local/include/glog/logging.h"返回文件.

我试过用

include_directories( "/usr/local/include" )

但GLOG_INCLUDE仍然未定义(找不到logging.h.)

Answer 1

看看CheckIncludeFileCXX.cmake.它应该在你的cmake安装目录中(我在/usr/share/cmake-2.8/Modules中有它).

该文件说明:

# The following variables may be set before calling this macro to
# modify the way the check is run:
#
#  CMAKE_REQUIRED_FLAGS = string of compile command line flags
#  CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
#  CMAKE_REQUIRED_INCLUDES = list of include directories
#  

因此,您可以在调用命令之前尝试设置此变量,如下所示:

set (CMAKE_REQUIRED_INCLUDES "/usr/local/include")
CHECK_INCLUDE_FILE_CXX(glog/logging.h GLOG_INCLUDE)
IF(GLOG_INCLUDE)
   MESSAGE("YY")
ENDIF(GLOG_INCLUDE)