A CIL Tutorial - Department of Computer Science - ETH Zürich

CHAPTER 3. DATAFLOW ANALYSIS 32
3.2 test/tut3.c
The result of the analysis in tut3.ml will be to print a message to the console for each variable of
integral type wherever it is used indicating whether it is even or odd at that program point. We
consider the results of the analysis on the code below:
../test/tut3.c
# include
int main()
{
int a,b,c,d;
a = 1; b = 2; c = 3; d = 4;
a += b + c;
c *= d - b;
b -= d + a;
if (a % 2) a++;
printf("a = %d, b = %d, c = %d, d = %d\n", a, b, c, d);
return 0;
}
We build this source with the dataow analysis enabled by doing:
$ ciltutcc --enable-tut3 -o tut3 test/tut3.c
test/tut3.c:14: (a, Bottom)
test/tut3.c:14: (b, Bottom)
test/tut3.c:14: (c, Bottom)
test/tut3.c:14: (d, Bottom)
test/tut3.c:15: (a, Odd)
test/tut3.c:15: (a, Odd)
test/tut3.c:15: (b, Even)
test/tut3.c:15: (c, Odd)
test/tut3.c:16: (c, Odd)
test/tut3.c:16: (c, Odd)
test/tut3.c:16: (d, Even)
test/tut3.c:16: (b, Even)
test/tut3.c:17: (b, Even)
test/tut3.c:17: (b, Even)
test/tut3.c:17: (d, Even)
test/tut3.c:17: (a, Even)
test/tut3.c:18: (a, Even)
test/tut3.c:18: (a, Even)
test/tut3.c:18: (a, Even)
test/tut3.c:19: (a, Top)
test/tut3.c:19: (b, Even)