Re: [Drbd-dev] user interface test of drbd.conf

[Helmut Wollmersdorfer <helmut@wollmersdorfer.at>]

Lars Ellenberg wrote:
> / 2004-10-21 14:36:16 +0200
> \ Helmut Wollmersdorfer:
> 
>>Lars Ellenberg wrote:
>>
>>>/ 2004-10-20 18:17:27 +0200
>>>\ Helmut Wollmersdorfer:

>>>>From my experience as tester I will not expect, that _any_ values will 
>>>>work correctly without "dry-run".

>>>hm?

>>Very easy explanation:
>>As we all know, usally numbers represented in text are converted to an 
>>easier to handle representation inside a program. This can be hex, 
>>decimal packed, floating etc. and mostly will be of fixed length. Even 
>>bignums will have an upper limit (e.g. 64Kdigits). If there is no check 
>>for a maximum value at input, funny things can happen in program logik 
>>afterwards: overruns, skip to negative values, truncated values, which 
>>possible could cause crazy program behaviour.

> but what has that to do with dry-run?

If I only test with dry-run, I only test the parser. This cannot uncover 
errors in afterwards logic.

> and to improve the scanner, maybe limiting to 9 digits will do?
[...]
> +OUT_OF_RANGE_NUM	  [0-9]{10,}[kmgKMG]? 
> +NUM			  [0-9]{1,9}
> +NUM_U			  [0-9]{1,9}[kmgKMG]?
Let's try
999999999k ~ 1 T
999999999M ~ 1000 T
999999999G ~ 1000000 T

[...]
>  <NUM>{
>    {NUM}			yy_pop_state(); CP; return TK_INTEGER;
> +  {OUT_OF_RANGE_NUM}	{
> +			  PRINTF("%s: number too big\n", yytext);
Better:
+	PRINTF("%s: number exceeds limit of 9 digits\n", yytext);


Helmut Wollmersdorfer