add_compile_string  544 regcomp.c            r = add_compile_string(prev, prev_len, blen, reg, ambig);
add_compile_string  554 regcomp.c        return add_compile_string(prev, prev_len, blen, reg, ambig);
add_compile_string  563 regcomp.c        return add_compile_string(sn->s, 1 /* sb */, sn->end - sn->s, reg, 0);