Re: -var-update @

[Nick Roberts <nickrob@snap.net.nz>]

 > > -var-update --all-values var1
 > > ^done,changelist=[{name="var1",in_scope="true",new_type="float",new_num_children="0"}]
 > > (gdb) 
 > > -var-update --all-values var2
 > > ^done,changelist=[{name="var2",value="-1080652880",in_scope="true",type_changed="false"}]
 > > (gdb)
 > 
 > This is weird. I did not look at var1 missing new value (should be easy),
 > but the var2 behaviour is strange. Evaluating 'myvar1' by hand gives the
 > right value, whereas -var-update gives this apparent garbage. My guess is
 > that that parsed expression somehow holds on to frame. I'll look further.

I think the patch below fixes the behaviour for var2.  There may be a less
expensive way to do this, e.g, just update the "struct value", but I don't know
how to do that.

 > >  > > I think we should fix (and document) such floating variable objects
 > >  > 
 > >  > We should; I was not aware of the bug with wrong value you report above.

There's still no doc or tests for this type of varobj.

 > > <snip>
 > > I would just suggest a more consistent syntax as currently:
 > > 
 > > -var-update @     Updates all floating variable objects.
 > > -var-update *     Updates all variable objects.
 > > -var-update var1  Updates the variable object var1 (floating or otherwise).
 > > 
 > > -var-create - @   Creates a floating variable object.
 > > -var-create - *   Creates a fixed frame variable object.
 > 
 > IIUC, the above is that current syntax? If yes, how do you propose to
 > change. If this is the proposed syntax, can you spell out the difference
 > from the current one?

This is the current syntax which I find confusing because "*" means "fixed" in
one context and "all" in another.  I'm not sure how to change it and remain
backward compatible.

-- 
Nick                                           http://www.inet.net.nz/~nickrob


2008-03-29  Nick Roberts  <nickrob@snap.net.nz>

	* varobj.c (varobj_update): Always mark floating variable objects
	as changed.
	(value_of_root): Always recreate a floating variable object.


*** varobj.c.~1.108.~	2008-03-27 08:02:16.000000000 +1200
--- varobj.c	2008-03-29 17:06:35.000000000 +1200
*************** varobj_update (struct varobj **varp, str
*** 1160,1177 ****
  	 has changed.  */
        new = value_of_root (varp, &type_changed);
        
!       /* If this is a floating varobj, and its type has changed,
! 	 them note that it's changed.  */
!       if (type_changed)
  	VEC_safe_push (varobj_p, result, *varp);
        
!         if (install_new_value ((*varp), new, type_changed))
! 	  {
! 	    /* If type_changed is 1, install_new_value will never return
! 	       non-zero, so we'll never report the same variable twice.  */
! 	    gdb_assert (!type_changed);
! 	    VEC_safe_push (varobj_p, result, *varp);
! 	  }
  
        if (new == NULL)
  	{
--- 1160,1176 ----
  	 has changed.  */
        new = value_of_root (varp, &type_changed);
        
!       /* If this is a floating varobj, then note that it's changed.  */
!       if ((*varp)->root->floating)
  	VEC_safe_push (varobj_p, result, *varp);
        
!       if (install_new_value ((*varp), new, type_changed))
! 	{
! 	  /* If type_changed is 1, install_new_value will never return
! 	     non-zero, so we'll never report the same variable twice.  */
! 	  gdb_assert (!type_changed);
! 	  VEC_safe_push (varobj_p, result, *varp);
! 	}
  
        if (new == NULL)
  	{
*************** value_of_root (struct varobj **var_handl
*** 1738,1758 ****
        old_type = varobj_get_type (var);
        new_type = varobj_get_type (tmp_var);
        if (strcmp (old_type, new_type) == 0)
- 	{
- 	  varobj_delete (tmp_var, NULL, 0);
  	  *type_changed = 0;
- 	}
        else
- 	{
- 	  tmp_var->obj_name =
- 	    savestring (var->obj_name, strlen (var->obj_name));
- 	  varobj_delete (var, NULL, 0);
- 
- 	  install_variable (tmp_var);
- 	  *var_handle = tmp_var;
- 	  var = *var_handle;
  	  *type_changed = 1;
! 	}
        xfree (old_type);
        xfree (new_type);
      }
--- 1737,1753 ----
        old_type = varobj_get_type (var);
        new_type = varobj_get_type (tmp_var);
        if (strcmp (old_type, new_type) == 0)
  	  *type_changed = 0;
        else
  	  *type_changed = 1;
! 
!       tmp_var->obj_name =
! 	savestring (var->obj_name, strlen (var->obj_name));
!       varobj_delete (var, NULL, 0);
!       install_variable (tmp_var);
!       *var_handle = tmp_var;
!       var = *var_handle;
! 
        xfree (old_type);
        xfree (new_type);
      }