a question about one part of gcc manual

[ali hagigat]

3.14 Options for Directory Search
-Idir
This is to ensure that GCC’s procedure to fix buggy system
headers and the ordering for the include next directive are not
inadvertently hanged.
-----------------------------
Sorry I do not have the answer yet!! I understood "include_next"
directive but what is the procedure of GCC to fix the system headers?
When we specify a path with -I and it is ignored because there is the
same name in the system directories, how it can fix the system headers
then?


On Tue, Apr 26, 2011 at 6:58 PM, Ian Lance Taylor <iant@google.com> wrote:
>
> ali hagigat <hagigatali@gmail.com> writes:
>
> > 3.14 Options for Directory Search
> > If a standard system include directory, or a directory specified with
> > ‘-isystem’, is also specified with ‘-I’, the ‘-I’ option will be
> > ignored. The directory will
> > still be searched but as a system directory at its normal position in
> > the system include chain.
> > -----------------------------------------------
> > What does that mean? Does it mean that the file is found at the
> > location -I has specified but it is marked as a system directory? or
> > the path specified by -i is ignored?
>
> It means that if you say "-I dir -isystem dir" the -I option is
> ignored.  It is as though you only said "-isystem dir".
>
> Ian