Re: Behavior of 'until' command

[Elena Zannoni <ezannoni at redhat dot com>]

Daniel Jacobowitz writes:
 > On Wed, Nov 13, 2002 at 02:19:35PM -0500, Elena Zannoni wrote:
 > > 
 > > The documenation says that 'until' does this:
 > > 
 > > "@item until
 > > Continue running until a source line past the current line, in the
 > > current stack frame, is reached. [...]@code{until} always stops your
 > > program if it attempts to exit the current stack frame.
 > > [...]
 > > 
 > > @item until @var{location} 
 > > Continue running your program until either the specified location is
 > > reached, or the current stack frame returns.  @var{location} is any of
 > > the forms of argument acceptable to @code{break}.  This form of the
 > > command uses breakpoints, and hence is quicker than @code{until}
 > > without an argument."
 > > 
 > > Note the 'will not exit the current stak frame' business.
 > > 
 > > However, nobody forbids you from saying "until foo" (since that's an
 > > OK argument for break as well).  And foo can be any function, called
 > > by the current frame or not.
 > > 
 > > It is not clear to me what the doco describes as gdb's
 > > behavior. Concrete example below:
 > > 
 > > 1	static int x;
 > > 2	
 > > 3	int fun ()
 > > 4	{
 > > 5	   x = 1;
 > > 6	}
 > > 7	
 > > 8	int fun2 ()
 > > 9	{
 > > 10	   x = 4;
 > > 11	}
 > > 12	
 > > 13	void foo()
 > > 14	{
 > > 15	  x = x + 5;
 > > 16	  fun2 ();
 > > 17	}
 > > 18	int main (int ac, char **av)
 > > 19	{
 > > 20	  x = 3;
 > > 21	  foo ();
 > > 22	  fun ();
 > > 23	  x = 3;
 > > 24	  return 0;
 > > 25	}
 > > 
 > > 
 > > If I am in 'foo' at line 15,and enter the command 'until fun', I
 > > would expect to end up ... where? At line 22?  Or should I end up at
 > > line 5? Right now gdb ends up at 22, i.e. doesn't enter 'fun'. I think
 > > it is consistent with the doco.
 > > 
 > > Similarly from foo line 15 where should 'until fun2' take me? Inside
 > > fun2, at line 10? Or at line 16? Currently I end up at line 22 which
 > > is in main. This seems clearly wrong either way.
 > > 
 > > Any thoughts?
 > 
 > Your reading sounds right to me.  If you look at the output of 'set
 > debug target 1' in your example, we set and hit the breakpoint in fun2
 > and then decide to continue for some reason - that's got to be a bug.

So do you agree that 'until fun2' should stop inside fun2, just like
"break fun2;continue" would? If so I have a fix. 

 > 
 > If you have a chance this would make a great testcase.
 > 

yes, this testcase is not in the testsuite.

Elena


 > -- 
 > Daniel Jacobowitz
 > MontaVista Software                         Debian GNU/Linux Developer