Frama-C Here are two links related to ptrdiff_t: Ptrdiff_t is evil [removed dead link] a blog post for if you are not tired of conversion and promotion issues yet and an interesting answer on StackOverflow. I was doubtful about the second one (I had no difficulties to accept the first one...
Read MoreI do not have any solution I am 100% happy with to the overflow dilemma in the previous post. Here is one of the solutions that does not make me 100% happy. The first (partial) solution is: program so that overflows correspond exactly to unwanted circumstances (and then it becomes...
Read MoreMy 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 MoreThere are only positive constants in C, as per section 6.4.4 in the C99 standard: integer-constant: decimal-constant integer-suffixopt octal-constant integer-suffixopt hexadecimal-constant integer-suffixopt decimal-constant: nonzero-digit decimal-constant digit octal-constant: 0 octal-constant octal-digit hexadecimal-constant: hexadecimal-prefix hexadecimal-digit hexadecimal-constant hexadecimal-digit ... The minus sign is not part of the constant according to the grammar. The...
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...
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