https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64284
--- Comment #2 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- trippels@gcc20 ~ % cat scp.i int *a; int b; int fn1() { enum { QSTRING } c = 0; while (1) { switch (*a) { case '\'': c = 0; default: switch (c) case 0: if (b) return 0; c = 1; } a++; } }