Re: [RFC] gdb.server testcases (resend)

[Wu Zhou <woodzltc@cn.ibm.com>]

On Mon, 23 May 2005, Daniel Jacobowitz wrote:

> Don't do that.  Please go read my proposal on gdb@, paying particular
> attention to the description of the MIPS execution environment.  The
> reason to always provide 64-bit registers if they are available is that
> they are physically present; the upper 32 bits can affect the behavior
> of the program in some cases.  So not displaying them can be very bad!

ok, I got it.  I will read your proposal more carefully.  Thanks.

> > That SIGFPE error disappeared after applying your patch to latest
> > GDB cvs tree.  But I met with another strange problem when debugging
> > gdb.base/break, which defines the following function:
> > 
> > int factorial (value)
> > int value;
> > #endif
> > {
> >   if (value > 1) {  /* set breakpoint 7 here */
> >         value *= factorial (value - 1);
> >     }
> >     return (value); /* set breakpoint 19 here */
> > }
> > 
> > normally factorial(6) will recursively call itself 5 times and return
> > 720.  However while using 64-bit gdbserver on 64-bit binary, it doesn't
> > call factorial(5) at all, return directly 6 as the result.
> > 
> > I am suspecting that "value > 1" doesn't get executed, so I change the
> > conditional statement to "if (value - 1)", it worked!  So it turn out
> > that "value > 1" always return 0 in this running context.  That is really
> > odd.  Any clues you could thought of?  Thanks in advance.  
>  
> Um... your compiler must be broken, then.

Um...can't understand this.  If it is like this, how to interpret the fact  
that it returns 720 correctly to run gdb.base/break standalone.  Anyway I 
will try to find another box or another compiler to verify this.  Thanks.

Cheers
- Wu Zhou