https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81638
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Just for reference we have: for (i = 0; i < vec->count; ++i) { incl = (struct xcoff_incl *) vec->vec.base + i; if (incl->begin <= lnnoptr && lnnoptr <= incl->end) break; } if (begincl == -1) begincl = (i < vec->count); if (i < vec->count) { filename = incl->filename; if (begincl == 1) lnno += fcn_lnno - 1; } else lnno += fcn_lnno - 1; Hmm, if i == 0 and vec->count is 0, then incl can be uninitialized. I can't find a way for GCC to know vec->count is non zero here ... Unless I miss something.