--- layout: fc_discuss_archives title: Message 18 from Frama-C-discuss on February 2010 ---
Hello, The slicing plugin rely on the results of the value analysis pluging which performs a context-sensitive Since slice computation is done after the value analysis, the slicing plugin can loose some precision even it can use context-sensitive information (-calldeps option) at function calls. It seems to be the case for your line 24. Looking at the result given by the gui with the development version of Frama-C, line 24 isn't green, nor striked out. That means the semantics of the line 24 doesn't impact the slicing criteria, but the line must be keept just for compilation reason (to be able to re-analyse code resulting from the slicing pulgin). These kinds of lines have a spare mark. Going back to your example, the spare mark of the line 24 is /imprecise/, but /correct. /Patrick. > Dear Pascal, > I have one more example code for contexst-sensitive points-to analysis. > In the following simple code, can we get a slicing results that do not > contain line 24 using Frama-C? > In my understanding, line 24 should not be included if > contexst-sensitive points-to analysis is working correctly. > > ------------- START test code ------------ > > typedef signed char s1; > typedef signed short s2; > typedef signed long s4; > typedef unsigned char u1; > typedef unsigned short u2; > typedef unsigned long u4; > typedef float f4; > typedef double f8; > > s2 f(s2* s2var) > { > return *s2var; > } > > void main(void) > { > s2 s2t_1; > s2 s2t_2; > s2 s2t_3; > s2 s2t_4; > s2 s2t_5; > s2 s2t_6; > > s2t_1 = 1; // line 24: should not be included > s2t_2 = 2; > > s2t_3 = f(&s2t_1); > s2t_4 = f(&s2t_2); > > s2t_5 = s2t_3; > s2t_6 = s2t_4; // line 31: criteria > } > > ------------- END test code ------------ > > > > _______________________________________________ > Frama-c-discuss mailing list > Frama-c-discuss at lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/frama-c-discuss > > -------------- section suivante -------------- Une pi?ce jointe HTML a ?t? enlev?e... URL: http://lists.gforge.inria.fr/pipermail/frama-c-discuss/attachments/20100210/c57a52a6/attachment.htm