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* bus error in sparc ultra 10 solaris 8 g++ 2.95 3.0
@ 2001-11-09 15:02 agustin
  2001-11-10  2:06 ` John Love-Jensen
  0 siblings, 1 reply; 2+ messages in thread
From: agustin @ 2001-11-09 15:02 UTC (permalink / raw)
  To: 'help-gcc@gnu.org'

unsigned long x;
> char p[15];
> .
>      strcpy (p, "abcdefghijkl");
>      x = *(unsigned long *)((char *)p + 3);     //   <<<----------------here bus error
> 
> why ??
> this instruction is not standard c ?? and why
> x = *(unsigned long *)((char *)p + 4);    // not failure ???
> 
> i know that can  write
>      memcpy ((char *)&x, (char *)(p+3), sizeof(unsigned long));
> 
> but what happen ??  error in compiler o ????
> thanks for your help.
> Agustin.


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: bus error in sparc ultra 10 solaris 8 g++ 2.95 3.0
  2001-11-09 15:02 bus error in sparc ultra 10 solaris 8 g++ 2.95 3.0 agustin
@ 2001-11-10  2:06 ` John Love-Jensen
  0 siblings, 0 replies; 2+ messages in thread
From: John Love-Jensen @ 2001-11-10  2:06 UTC (permalink / raw)
  To: agustin, help-gcc

You are trying to perform an illegal operation on the Sun architecture.

A char* is not a long*.

The Sun architecture requires that long data is aligned.  You are attempting
an unaligned access, which will cause a BUS signal.

Don't cast.  Casts are indicative that you may be doing something wrong.  In
this instance, you are.

--Eljay


^ permalink raw reply	[flat|nested] 2+ messages in thread

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