contract with only internal functions is executable

[tserg]

Version Information

• vyper Version (output of vyper --version): 95bf73f
• OS: linux
• Python Version (output of python --version): 3.10.8

What's your issue about?

A contract that only has internal functions besides the constructor may still compile to executable code. Internals are not pruned, and execution of the internal functions section is not guarded. Upon calling the contract, execution will start at the first internal function. However, execution will generally fail when POPping the RETURN_PC from the stack, which should be empty upon function exit.

h/t @trocher @ptrcarta

How can it be fixed?

Fill this in if you know how to fix it.

[charles-cooper]

this was resolved in #3496

[charles-cooper]

repro:

$ vyc -f ir_runtime /dev/stdin <<EOF
@internal
def foo():
  pass

EOF
[seq,
  [goto, fallback],
  [label, fallback, var_list, /* Default function */ [revert, 0, 0]],
  [seq,
    [label,
      internal_foo____runtime,
      [var_list, return_pc],
      [seq, [exit_to, internal_foo____cleanup, return_pc], pass]],
    [label, internal_foo____cleanup, [var_list, return_pc], [exit_to, return_pc]]]]