[Cmake] INCLUDE_DIRECTORIES and empty strings

[Sebastien BARRE]

At 6/24/2002 03:33 PM, Wheeler, Fred (Research) wrote:
>With CMake 1.4 beta making NMake makefiles in win32, the following
>
>   SET( OPENGL_INCLUDE_PATH "" )
>   INCLUDE_DIRECTORIES(${OPENGL_INCLUDE_PATH})
>
>leads to compile commands that look like this

[...]

>Bottom line: it would be nice if INCLUDE_DIRECTORIES did nothing when 
>passed an empty string.

You can test if your var is empty before trying to "include" it.

CMake 1.2, 1.4beta and CVS always had the same behaviour regarding 
OPENGL_INCLUDE_PATH in the FindOpenGL.cmake module: it is not defined for 
Win32 system.

What is done in VTK is:

IF (OPENGL_INCLUDE_PATH)
   INCLUDE_DIRECTORIES(${OPENGL_INCLUDE_PATH})
ENDIF(OPENGL_INCLUDE_PATH)


--
Sebastien Barre