Re: relative include search path

[Dave Korn <dave dot korn dot cygwin at googlemail dot com>]

Denis Onischenko wrote:
> I have a problem with gcc not finding location for stddef.h include
> file when it is invoked from directory other than
> <install_prefix>/bin.

  Questions about the usage of GCC should go to the gcc-help mailing list,
rather than this one which is about the development of the internals of GCC.
What you have discovered here may appear to be a bug, but in fact it is by
design, so please send any follow-ups to the gcc-help list, thank you.

> Output from gcc invocation with -v option contains the following:
>
> ignoring nonexistent directory "../lib/gcc..."
>
> i.e. gcc is trying to find include files in directory with relative path.
> So it is works only when working directory is /usr/bin, where gcc is installed.
>
> Why gcc looks for headers in directories with relative paths ?

  So that you can move the entire installation somewhere else and it will all
work because it will all be in the same relative locations compared to the new
$prefix as it was when installed in the original $prefix.

  What you have done is move a single part of the installation to a new
location and leave the rest behind.  That is not supported, and there's no
simple and direct way in which it could be.

    cheers,
      DaveK