[CMake] FIND_PATH with multiple path in a single variable

[Brad King]

frederic heem wrote:
> Hi,
> Here is the problem, pkgconfig is used to get the include path, for dbus, its 
> value is "-I/usr/include/dbus-1.0 -I/usr/lib/dbus-1.0/include" and the 
> variable name is DBUS_INCLUDE_DIR_SYSTEM. The following FIND_PATH fails to 
> find the include files:
> FIND_PATH(DBUS_INCLUDE_DIR dbus/dbus.h
>   ${DBUS_INCLUDE_DIR_SYSTEM}
> )
> 
> Is it a known issue ?

There are a few problems here.  First, paths are specified using the
PATHS keyword:

FIND_PATH(DBUS_INCLUDE_DIR dbus/dbus.h
  PATHS ${DBUS_INCLUDE_DIR_SYSTEM}
  )

Second, the output of pkgconfig cannot be used directly.  FIND_PATH does
not recognize the string "-I/usr/include/dbus-1.0
-I/usr/lib/dbus-1.0/include" as a list of search paths.  You have to use
STRING(REGEX) to parse out the paths.  Once you have them you don't
actually need FIND_PATH at all though.  Just set DBUS_INCLUDE_DIRS to
the result.

-Brad