Joseph Ferano
58b1f49cf2
edn.flan crashed by jumping into .rodata, several statements after the mistake, and the assembly at the jump read correctly. Item 15 said this is how hand-encoding fails, and it is: the crash and the cause were in different functions. The cause is one line of design. A form whose value is thrown away was handed the sink, and the sink was spelled as an address — rbp+0. That is the saved rbp, and rbp+8 is the return address, so a non-void form in statement position stored its value straight over both. A 16-byte slice did it in one rep movsb. The sink is now compared by identity and never used as an address: anything with a value that is handed it gets a frame temporary instead, reclaimed immediately. The point is not the temporary, it is that the store has somewhere legal to go. edn.flan matches the LLVM build now — 60 lines of a hand-written EDN reader, unions, options, nested collections and all.
