[CMake] New FIND_* stuff checked into CVS

[Brad King]

Filipe Sousa wrote:
> Bill Hoffman wrote:
>>FIND_PATH(QT_INCLUDE NAMES qt.h PATH_SUFFIXES qt)
>>
>>CMake will find it in /usr/local/include/qt/qt.h and set QT_INCLUDE
>>to /usr/local/include.
> 
> fsousa at black ~/tmp/find/build $ ls -l /usr/local/include/qt/qt.h
> - -rw-r--r--  1 root root 0 Mar  4 11:00 /usr/local/include/qt/qt.h
> 
> FIND_PATH(QT_INCLUDE NAMES qt.h PATH_SUFFIXES qt)
> MESSAGE(STATUS ${QT_INCLUDE})
[snip]
> Here QT_INCLUDE is /usr/local/include/qt and not /usr/local/include

This is the intended behavior, Bill's example was incorrect.  If you 
want to find qt/qt.h then you would still do

FIND_PATH(QT_INCLUDE NAMES qt/qt.h)

The purpose of the PATH_SUFFIXES option is to provide extra places to 
look in subdirectories of those in the rest of the search path.  The 
motivation is libraries like libxml2 which on Windows installs to 
PREFIX/include/libxml2/libxml/*.h, but the include files are supposed to 
be libxml/*.h.  In order to avoid requiring users to list the libxml2 
subdirectory in their search path one may use the PATH_SUFFIXES option:

FIND_PATH(
   LIBXML2_INCLUDE_DIR
   NAMES libxml/xpath.h
   PATH_SUFFIXES libxml2
   )

This will set LIBXML2_INCLUDE_DIR to PREFIX/include/libxml2 even though 
only PREFIX/include was in the search path (presumably in 
CMAKE_SYSTEM_INCLUDE_PATH).

-Brad