install/48303: Linux cross build fails on ppc

[justin%specialbusservice.com@localhost]

>Number:         48303
>Category:       install
>Synopsis:       Linux cross build fails on ppc
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Oct 12 10:05:01 +0000 2013
>Originator:     Justin Cormack
>Release:        cvs head
>Organization:
>Environment:
Linux pike 3.6.7-4.fc17.ppc64 #1 SMP Thu Dec 6 06:41:58 MST 2012 ppc64 ppc64 
ppc64 GNU/Linux

>Description:
I am trying to cross build NetBSD on ppc:
./build.sh -m evbppc build

This fails with

#   compile  compat/raise_default_signal.lo
cc -O  -I. -I./include -I/home/justin/src/tools/compat 
-I/home/justin/src/tools/compat/sys  -DHAVE_NBTOOL_CONFIG_H=1 
-D_FILE_OFFSET_BITS=64 -D__DBINTERFACE_PRIVATE -c -o raise_default_signal.lo.o  
  /home/justin/src/tools/compat/../../lib/libutil/raise_default_signal.c
In file included from /usr/include/signal.h:359:0,
                 from 
/home/justin/src/tools/compat/../../lib/libutil/raise_default_signal.c:42:
/usr/include/sys/ucontext.h:101:16: error: expected identifier or '(' before 
'[' token

*** Failed target:  raise_default_signal.lo


The issue in that that Linux header has a field called __unused:

typedef struct {
        unsigned long   __unused[4];

(which Linux does quite a bit); however __unused has been #defined to an empty 
string so it will not compile.

>How-To-Repeat:
Cross build from recent ppc linux.

>Fix:
I would be surprised if this hasnt been worked around elsewhere, as Linux uses 
__unused a fair amount in headers. It would seem best to use something else to 
avoid collisions.