Bug#458745: arm-only miscompilation of alloca code

[Camm Maguire <camm@enhanced.com>]

Package: gcc-4.2
Version: 4.2.2-4
Severity: important

/tmp/foo.c:
=============================================================================
#include <stdio.h>
#include <alloca.h>
#include <stdarg.h>
#define object void *

int VFUN_NARGS;
void *alloca_val;
struct cons {
  object c_cdr;
  object c_car;
};

#define Cnil 0

static void
foo(object first,...) {
  va_list ap;
  int narg = VFUN_NARGS;
  struct cons *V1128;
  object V1129;

  va_start(ap,first);
  V1129 = 
    !narg? Cnil : (alloca_val=alloca((narg)*sizeof(struct cons)+sizeof(object)),
		   ({object _b=(void *)alloca_val;if (((unsigned long)_b)&sizeof(_b)) _b++;
		   {register struct cons *_p=(void *)_b;
		   {struct cons *_e=_p+(narg-1);
		   for (;_p<_e;_p++) {_p->c_car=({object _t=first;first=va_arg(ap,object);_t;});_p->c_cdr=(object)(_p+1);}}
		   _p->c_car=first;_p->c_cdr=Cnil;}_b;}));
  va_end(ap);
  V1128= V1129;
  for (;V1128!=Cnil;V1128=V1128->c_cdr)
    printf("%p\n",V1128->c_car);

}

int
main(int argc,char * argv[]) {

  VFUN_NARGS=4;
  foo(&argc,1,2,3);
  return 0;

}
=============================================================================
i386 sid:
=============================================================================
cc -g /tmp/foo.c -o /tmp/foo
/tmp/foo
0xbf867bd0
0x1
0x2
0x3
=============================================================================
leisner dchroot sid:
=============================================================================
cc -g foo.c -o foo
./foo
0x18beed5d
Segmentation fault
=============================================================================

Take care,

-- System Information:
Debian Release: lenny/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: i386 (i686)

Kernel: Linux 2.6.20-gen
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/bash

Versions of packages gcc-4.2 depends on:
ii  binutils            2.18.1~cvs20071027-1 The GNU assembler, linker and bina
ii  cpp-4.2             4.2.2-4              The GNU C preprocessor
ii  gcc-4.2-base        4.2.2-4              The GNU Compiler Collection (base 
ii  libc6               2.7-2                GNU C Library: Shared libraries
ii  libgcc1             1:4.2.2-4            GCC support library
ii  libgomp1            4.2.2-4              GCC OpenMP (GOMP) support library

Versions of packages gcc-4.2 recommends:
ii  libc6-dev                     2.7-2      GNU C Library: Development Librari

-- no debconf information