Re: [PATCH 43/98] include/uapi/linux/hdlc/ioctl.h: include linux/if.h

On Sat, May 30, 2015 at 10:22:53PM +0200, Frans Klaver wrote:

On Sat, May 30, 2015 at 05:38:35PM +0200, Mikko Rapeli wrote:

quoted

Fixes userspace compiler error:

error: ‘IFNAMSIZ’ undeclared here (not in a function)

Signed-off-by: Mikko Rapeli <redacted>
---
 include/uapi/linux/hdlc/ioctl.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/hdlc/ioctl.h b/include/uapi/linux/hdlc/ioctl.h
index 04bc027..8bbee11 100644
--- a/include/uapi/linux/hdlc/ioctl.h
+++ b/include/uapi/linux/hdlc/ioctl.h

@@ -1,6 +1,7 @@
 #ifndef __HDLC_IOCTL_H__
 #define __HDLC_IOCTL_H__
 
+#include <linux/if.h>
 
 #define GENERIC_HDLC_VERSION 4	/* For synchronization with sethdlc utility */

What's the point of this one if you break this circular dependency in
patch 49? Are those in between related?

They are indeed...

On Sat, May 30, 2015 at 09:52:23PM +0200, Frans Klaver wrote:

On Sat, May 30, 2015 at 05:38:41PM +0200, Mikko Rapeli wrote:

quoted

This isn't pretty but does the job. I assume including plain linux/hdlc/ioctl.h
without linux/if.h is much more rare than the other way round, and that
these header file names are part of API, and that creating a new header file
just for IFNAMSIZ isn't a good idea either.

Fixes userspace compiler error:

error: ‘IFNAMSIZ’ undeclared here (not in a function)

Signed-off-by: Mikko Rapeli <redacted>
---
 include/uapi/linux/hdlc/ioctl.h | 5 ++++-
 include/uapi/linux/if.h         | 4 ++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/hdlc/ioctl.h b/include/uapi/linux/hdlc/ioctl.h
index 8bbee11..73982ec 100644
--- a/include/uapi/linux/hdlc/ioctl.h
+++ b/include/uapi/linux/hdlc/ioctl.h

@@ -1,7 +1,10 @@
 #ifndef __HDLC_IOCTL_H__
 #define __HDLC_IOCTL_H__
 
-#include <linux/if.h>
+/* For breaking dependency loop between if.h and hdlc/ioctl.h */
+#ifndef IFNAMSIZ
+#define IFNAMSIZ        16
+#endif
 
 #define GENERIC_HDLC_VERSION 4	/* For synchronization with sethdlc utility */
 

diff --git a/include/uapi/linux/if.h b/include/uapi/linux/if.h
index 9cf2394..e4b130a 100644
--- a/include/uapi/linux/if.h
+++ b/include/uapi/linux/if.h

@@ -23,6 +23,10 @@
 #include <linux/socket.h>		/* for "struct sockaddr" et al	*/
 #include <linux/compiler.h>		/* for "__user" et al           */
 
+/**
+ * IFNAMSIZ is also defined in linux/hdlc/ioctl.h if it does not exists
+ * to break dependency loop between linux/if.h and linux/hdlc/ioctl.h.
+ */
 #define	IFNAMSIZ	16
 #define	IFALIASZ	256
 #include <linux/hdlc/ioctl.h>

This feels backwards to me. Wouldn't it be less funky to accept that
IFNAMSIZE isn't defined in if.h, but rather in hdlc/ioctl.h? If now

That is much less funky, thanks! I'll squash these to commits into a one
which moves IFNAMSIZ to linux/hdlc/ioctl.h.

-Mikko