port-powerpc/43041: powerpc64 c++ compiler emits code with reference to undefined __libc_stack_end

[dennis.c.ferguson%gmail.com@localhost]

>Number:         43041
>Category:       port-powerpc
>Synopsis:       powerpc64 c++ compiler emits code with reference to undefined 
>__libc_stack_end
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    port-powerpc-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Mar 23 09:30:00 +0000 2010
>Originator:     Dennis Ferguson
>Release:        very recent 5.99.24
>Organization:
>Environment:
NetBSD timerxxx.akit-ferguson.com 5.99.24 NetBSD 5.99.24 (GENERIC) #0: Mon Mar 
22 15:11:34 HKT 2010  
dennis%dennisbigmac.akit-ferguson.com@localhost:/Users/dennis/NetBSD/5.0-current/src/sys/arch/amd64/compile/obj/GENERIC
 amd64

>Description:
Loading a powerpc64 c++ program (any program, I think) fails
with an unresolved external reference to __libc_stack_end.
Here's the first one build.sh tries to make:

#      link  grodvi/grodvi
/usr/src/obj/tooldir.NetBSD-5.99.24-amd64/bin/powerpc64--netbsd-gcc  
-B/usr/src/obj/destdir.macppc/usr/lib/ -B/usr/src/obj/destdir.macppc/usr/lib/  
-Wl,-nostdlib       -o grodvi  dvi.o 
/usr/src/gnu/usr.bin/groff/src/libs/libdriver/obj/libdriver.a 
/usr/src/gnu/usr.bin/groff/src/libs/libgroff/obj/libgroff.a -lm -lsupc++      
-L/usr/src/obj/destdir.macppc/usr/lib   
-Wl,-rpath-link,/usr/src/obj/destdir.macppc/lib  
-L/usr/src/obj/destdir.macppc/lib 
-Wl,-rpath-link,/usr/src/obj/destdir.macppc/usr/lib  
-L/usr/src/obj/destdir.macppc/usr/lib
/usr/src/obj/destdir.macppc/usr/lib/libgcc_eh.a(unwind-dw2.o):(.toc+0x20): 
undefined reference to `__libc_stack_end'
collect2: ld returned 1 exit status

The code which makes the reference is being emitted by
the compiler.
>How-To-Repeat:
Do a:

    MACHINE=macppc64 ./build.sh distribution
>Fix:
The code in question is in
src/gnu/dist/gcc4/gcc/config/rs6000/linux-unwind.h,
which ends up being included in the compiler via
src/gnu/dist/gcc4/gcc/config/rs6000/netbsd64.h.  I
think the latter is just a boo-boo; even if the external
reference were somehow fixed I don't think the rest of
the code can be usefully used with NetBSD.  Note that
the thing being done in there is more of a platform thing
than a particular processor thing; if rs6000/netbsd64.h
needed an equivalent then surely so would rs6000/netbsd.h
and likely the other NetBSD ports too.  Because rs6000/netbsd.h
gets by without it I'm fairly comfortable the following is
correct:


Index: netbsd64.h
===================================================================
RCS file: /cvsroot/src/gnu/dist/gcc4/gcc/config/rs6000/netbsd64.h,v
retrieving revision 1.5
diff -u -r1.5 netbsd64.h
--- netbsd64.h  4 Feb 2008 04:20:51 -0000       1.5
+++ netbsd64.h  23 Mar 2010 09:06:11 -0000
@@ -571,6 +571,4 @@
 #define LINK_GCC_C_SEQUENCE_SPEC \
   "%{static:--start-group} %G %L %{static:--end-group}%{!static:%G}"
 
-#define MD_UNWIND_SUPPORT "config/rs6000/linux-unwind.h"
-
 #define POWERPC_NETBSD