Re: [Ql-Users] DEBUG
Hi George There is an error in the Turbo parser at line 14490. Here is this line: 14490 IF var%0 AND (struct%(var%)directive_mask%)=directive_mask% Both sides of the AND get to be evaluated. Although var% is tested for being non negative on the left hand side, the right hand side will be evaluated in any event. Should var% happen to be negative, then struct%(var%) would be outside of the array bounds and will crash SuperBASIC. The above line needs to be re written so that the right hand side will only be evaluated if the left hand side evaluates to true. Here is my suggested work-around: 1 LOCal both : REMark (if needed) 14488 both = 0 14489 IF var%0:IF (struct%(var%)directive_mask%)=directive_mask% : both = 1 14490 IF both Michael ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] DEBUG
Hi Michael On 22 Feb 2012, at 13:31, Michael Bulford wrote: There is an error in the Turbo parser at line 14490. Here is this line: 14490 IF var%0 AND (struct%(var%)directive_mask%)=directive_mask% Both sides of the AND get to be evaluated. Although var% is tested for being non negative on the left hand side, the right hand side will be evaluated in any event. Should var% happen to be negative, then struct%(var%) would be outside of the array bounds and will crash SuperBASIC. You are quite right. But how did you get var%=-3? Does this imply another mistake in Parser? The above line needs to be re written so that the right hand side will only be evaluated if the left hand side evaluates to true. Here is my suggested work-around: 1 LOCal both : REMark (if needed) 14488 both = 0 14489 IF var%0:IF (struct%(var%)directive_mask%)=directive_mask% : both = 1 14490 IF both My solution is: 14490 IF var%0 14494 IF (struct%(var%)directive_mask%)=directive_mask%:Parse_Directive:ELSE Skip_Stmt Cheers George ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] DEBUG
Hi George On Wednesday, 22 February 2012, 14:24 George Gwilt wrote: You are quite right. But how did you get var%=-3? Does this imply another mistake in Parser? No, I don't think so. -3 comes from for_flag% for an earlier occurence of p Your solution looks the best - it's neater. Michael ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] DEBUG
In message 1329917514.17351.yahoomail...@web171518.mail.ir2.yahoo.com, Michael Bulford michaelbulf...@yahoo.co.uk writes Hi George There is an error in the Turbo parser at line 14490. Here is this line: 14490 IF var%0 AND (struct%(var%)directive_mask%)=directive_mask% Both sides of the AND get to be evaluated. Although var% is tested for being non negative on the left hand side, the right hand side will be evaluated in any event. Should var% happen to be negative, then struct%(var%) would be outside of the array bounds and will crash SuperBASIC. The above line needs to be re written so that the right hand side will only be evaluated if the left hand side evaluates to true. Here is my suggested work-around: 1 LOCal both : REMark (if needed) 14488 both = 0 14489 IF var%0:IF (struct%(var%)directive_mask%)=directive_mask% : both = 1 14490 IF both Michael I use the logical method, of defining 'true' and 'false', as a global value in a program. 500 true=1 : false=NOT true Then you can use 1000 IF true 1010 REMark Take an action ... etc . This makes the program easier to follow. -- Malcolm Cadman ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
