The "graph" binary segfaults on this input: asm(""); with gdb saying (edited for clarity): Program received signal SIGSEGV, Segmentation fault. in graph_ep (ep=0x7ffff7f62010) at graph.c:52 (gdb) p ep->entry $1 = (struct instruction *) 0x0 Sadly, the commit that introduced this crash: 15fa4d60e ("topasm: top-level asm is special") was (part of a bigger series) meant to fix crashes because of such toplevel asm statements. Toplevel ASM statements are quite abnormal: * they are toplevel but anonymous symbols * they should be limited to basic ASM syntax but are not * they are given the type SYM_FN but are not functions * there is nothing to evaluate or expand about it. These cause quite a few problems including crashes, even before the above commit. So, before handling them more correctly and instead of adding a bunch of special cases here and there, temporarily take the more radical approach of stopping to add them to the list of toplevel symbols. Fixes: 15fa4d60ebba3025495bb34f0718764336d3dfe0 Reported-by: Vegard Nossum <vegard.nossum@gmail.com> Analyzed-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>