Runtime error when running with clang -fsanitize=undefined

[guillaumechereau]

To reproduce, I built the code 'examples' with the following command on my mac:

cd examples
clang test_json.c ../json.c -I ../ -fsanitize=undefined

Then when I run:

./a.out ../tests/valid-0000.json

I get this runtime warning:

../json.c:437:34: runtime error: applying non-zero offset 8 to null pointer

It seems to work if I replace in the code the line:

json_car **char = (json_char **) &top->u.object.values;

by:

intptr_t *chars = (intptr_t *) &top->u.object.values;