Frama-C My colleague Bernard Botella pointed out an interesting example in an offline discussion following the last quiz. The setup Consider the snippet: int s; unsigned u1 u2; ... s = u1 - u2; The programmer's intention with the assignment is to compute in variable s of type int the mathematical...
Read MoreWhat does the following program print? long long l; #include <stdio.h> int main() { l = -0x80000000; printf(\%lld" l); } $ gcc t.c && ./a.out And this one? (beware trick question) long long l; #include <stdio.h> int main() { l = -2147483648; printf("%lld" l); } $ gcc t.c && ./a.out...
Read MoreReminiscing The first benchmark Frama-C's value analysis was ever evaluated on was the Verisec suite, described in "A buffer overflow benchmark for software model checkers". My colleague Géraud Canet was doing the work thence the facetious-colleagues tag of this post. In retrospect Verisec was a solid piece of work. Being...
Read MoreIf Frama-C doesn't work out, we can always make a comedy team Facetious colleagues ask me how I make Frama-C's value analysis' messages so informative. \Pascal " one of them says "in this case study the generated log contains 8GiB of information! It won't open in Emacs...". I helpfully point...
Read MoreMy colleagues are formidable. Over the last few days, three of them fixed four bugs in my code. And one of the fixes was a simple, obviously correct fix for the bug previously discussed here. In celebration of these terrific colleagues here is a new patchset for Nitrogen 20111001 patchlevel...
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