[Cmake] FindLibrary problems

[Brad King]

> Suppose I have a CMakeLists.txt in a directory (/proj/dir) which
> contains a sub-directory called `mex'.  FIND_LIBRARY(mex PATH
> ${MATLAB_LIB_DIR}) will return /proj/dir/mex which is not a library (or
> even a regular file) even though there is a libmex.so in
> ${MATLAB_LIB_DIR}.  These sections
>
> --- cmSystemTools.cxx	14 Feb 2003 15:56:21 -0000	1.218
> +++ cmSystemTools.cxx	28 Feb 2003 12:26:25 -0000
> @@ -1625,12 +1625,6 @@
>  std::string cmSystemTools::FindLibrary(const char* name,
>                                         const std::vector<std::string>& userPaths)
>  {
> -  // See if the executable exists as written.
> -  if(cmSystemTools::FileExists(name))
> -    {
> -    return cmSystemTools::CollapseFullPath(name);
> -    }
> -

We cannot rule out the possibility that the file exists as written.  The
string "mex" is a valid library name on unix.  It just cannot be used with
a -l flag, but it can be used if the full path is given to ld.

Try changing the test to

  if(cmSystemTools::FileExists(name) &&
     !cmSystemTools::FileIsDirectory(name))

That should reduce the restrictions on source tree structure.  If this
works, let me know and I'll include it in CMake proper, along with a
documentation update.

We could also consider only doing this check if the name has slashes in
it.

-Brad