Compiler Panic When Popping From or Appending to an Empty Array

[ritzdorf]

Version Information

• vyper Version (output of vyper --version OR linkable commit hash vyperlang/vyper@): vyperlang/vyper@b43fface148b45cbd2c90b5d24f77398a63745b5

  Issue Description

When pop-ing from or append-ing to an empty array (empty(T)), the compiler panics when trying to call FunctionAnalyzer._handle_modification() on the empty array.

POC

The following code will make the compiler panic:

@external
def bar():
    a:uint128 = empty(DynArray[uint128,2]).pop() # CompilerPanic: unhandled exception 

@external
def bar():
    empty(DynArray[uint128,2]).append(1) # CompilerPanic: unhandled exception