kernelnewbies.kernelnewbies.org archive mirror
 help / color / mirror / Atom feed
From: Martin Kaiser <lists@kaiser.cx>
To: kernelnewbies@kernelnewbies.org
Subject: Re: internal / external include files
Date: Wed, 24 Jul 2019 23:20:53 +0200	[thread overview]
Message-ID: <20190724212053.zynpswlhepi52dhi@viti.kaiser.cx> (raw)
In-Reply-To: <20190724092133.GA6035@kroah.com>

Thus wrote Greg KH (greg@kroah.com):

> That's odd, what did you ask to be included that caused that?

I called gcc with -I $KERNEL_ROOT/include/uapi. This is the chain of
files that were included.

my_app.c
   $GCC_SYSROOT/usr/include/netinet/in.h
      $GCC_SYSROOT/usr/include/sys/socket.h
         $KERNEL_ROOT/include/uapi/asm-generic/socket.h
            $KERNEL_ROOT/include/uapi/linux/posix_types.h
               $KERNEL_ROOT/include/uapi/linux/stddef.h


and the error is

$KERNEL_ROOT/include/uapi/linux/stddef.h:2:34: fatal error:
linux/compiler_types.h: No such file or directory
#include <linux/compiler_types.h>

> > This fails because the kernel's stddef.h includes
> > include/linux/compiler_types.h and this file is internal to
> > the kernel.

> What kernel version did this happen for?

I get the error with today's linux-next tree. 4.14 is fine.

> > What is the correct way to solve this? Should I fix my include path to
> > make sure that my application picks the stddef.h in the compiler's
> > sysroot rather than the kernel's stddef.h?

> The system stddef.h should always be used "first".

My understanding of the gcc manual is that directories specified with -I
are searched before the system directories.

https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Directory-Options.html#Directory-Options

So it seems that -I /my/kernel/include/uapi is not a good idea since the
kernel's include files take precedence then.

Best regards,
Martin

_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

  reply	other threads:[~2019-07-24 21:21 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-24  9:11 internal / external include files Martin Kaiser
2019-07-24  9:21 ` Greg KH
2019-07-24 21:20   ` Martin Kaiser [this message]
2019-07-25  5:45     ` Re[3]: " Konstantin Andreev

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190724212053.zynpswlhepi52dhi@viti.kaiser.cx \
    --to=lists@kaiser.cx \
    --cc=kernelnewbies@kernelnewbies.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).