"include ../include/autoconf.h" and LINUXINCLUDE?

[Denys Vlasenko]

On Wednesday 16 July 2008 18:21, Robert P. J. Day wrote:
> 
>   (i've been away from BB for quite some time and am just getting back
> to it, so forgive what will undoubtedly be some dumb questions for a
> while.)
> 
>   i'm curious about the need for the hack(?) as is found in, for
> example, applets/usage.c:
> 
> ...
> /* Just #include "autoconf.h" doesn't work for builds in separate
>  * object directory */
> #include "../include/autoconf.h"
> ...
> 
>   but why can't the build process recognize that the build is being
> done in a separate object directory and fix the header include paths
> accordingly for the subsequent compile step?  it doesn't sound that
> hard to do.

Try to build it, and you'll see why it doesn't work.

If you find a nicer way to do it, I'm interested.

>   and in the top-level Makefile, we have:
> 
> # Use LINUXINCLUDE when you must reference the include/ directory.
> # Needed to be compatible with the O= option
> 
>   ok, but where is LINUXINCLUDE actually being set or used?
> 
> $ grep -rw LINUXINCLUDE *
> Makefile:# Use LINUXINCLUDE when you must reference the include/ directory.
> Makefile:export CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
> $
> 
>   from here, it doesn't appear that that variable is being used a
> whole lot.

Hehe :) The Makefile is way more awkward than that, because it was stolen
and adapted from Linux kernel almost 1:1. It talks about modules
and System.map! :) On the plus side, it made build process more reliable.
"make -j N" magically started working etc...
--
vda