a question about one part of gcc manual

[Ian Lance Taylor]

ali hagigat <hagigatali@gmail.com> writes:

> Thank you for the explanation but you did not explain the role of
> "include_next" here!! You only insisted on some path is ignored!!!

That is not what Jonathan said.  The -I option is ignored.  The path is
not ignored, because the -isystem option is not ignored.

> I know that when we use -I  and there is the same pathname in the
> system , -I is ignored!!

Yes, -I is ignored.

> But WHERE "include_next" is used?

Install gcc.  Look for .h files in the gcc install tree.  Look to see
which ones use #include_next.  Think about what it means.

> Is it used with -isystem and in the file it is introducing ONLY?

The -isystem option is independent of the #include_next directive,
except in the sense that -isystem gives directories for #include_next to
search.

> Please rewrite this part of gcc manual, it is not clear at all!!

Which part specifically is not clear?  As far as I know the -I and
-isystem options and the #include_next directive are described
correctly.

Ian