.. py:module:: ethereum.gray_glacier.vm.exceptions

Ethereum Virtual Machine (EVM) Exceptions
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. contents:: Table of Contents
    :backlinks: none
    :local:

Introduction
------------

Exceptions which cause the EVM to halt exceptionally.


.. only:: stage1

Module Contents
---------------


ExceptionalHalt
~~~~~~~~~~~~~~~


Indicates that the EVM has experienced an exceptional halt. This causes
execution to immediately end with all gas being consumed.


.. exception:: ExceptionalHalt


   Bases: :py:obj:`ethereum.exceptions.EthereumException`



Revert
~~~~~~


Raised by the `REVERT` opcode.

Unlike other EVM exceptions this does not result in the consumption of all
gas.


.. exception:: Revert


   Bases: :py:obj:`ethereum.exceptions.EthereumException`



StackUnderflowError
~~~~~~~~~~~~~~~~~~~


Occurs when a pop is executed on an empty stack.


.. exception:: StackUnderflowError


   Bases: :py:obj:`ExceptionalHalt`



StackOverflowError
~~~~~~~~~~~~~~~~~~


Occurs when a push is executed on a stack at max capacity.


.. exception:: StackOverflowError


   Bases: :py:obj:`ExceptionalHalt`



OutOfGasError
~~~~~~~~~~~~~


Occurs when an operation costs more than the amount of gas left in the
frame.


.. exception:: OutOfGasError


   Bases: :py:obj:`ExceptionalHalt`



InvalidOpcode
~~~~~~~~~~~~~


Raised when an invalid opcode is encountered.


.. exception:: InvalidOpcode


   Bases: :py:obj:`ExceptionalHalt`



InvalidJumpDestError
~~~~~~~~~~~~~~~~~~~~


Occurs when the destination of a jump operation doesn't meet any of the
following criteria:

  * The jump destination is less than the length of the code.
  * The jump destination should have the `JUMPDEST` opcode (0x5B).
  * The jump destination shouldn't be part of the data corresponding to
    `PUSH-N` opcodes.


.. exception:: InvalidJumpDestError


   Bases: :py:obj:`ExceptionalHalt`



StackDepthLimitError
~~~~~~~~~~~~~~~~~~~~


Raised when the message depth is greater than `1024`


.. exception:: StackDepthLimitError


   Bases: :py:obj:`ExceptionalHalt`



WriteInStaticContext
~~~~~~~~~~~~~~~~~~~~


Raised when an attempt is made to modify the state while operating inside
of a STATICCALL context.


.. exception:: WriteInStaticContext


   Bases: :py:obj:`ExceptionalHalt`



OutOfBoundsRead
~~~~~~~~~~~~~~~


Raised when an attempt was made to read data beyond the
boundaries of the buffer.


.. exception:: OutOfBoundsRead


   Bases: :py:obj:`ExceptionalHalt`



InvalidParameter
~~~~~~~~~~~~~~~~


Raised when invalid parameters are passed.


.. exception:: InvalidParameter


   Bases: :py:obj:`ExceptionalHalt`



InvalidContractPrefix
~~~~~~~~~~~~~~~~~~~~~


Raised when the new contract code starts with 0xEF.


.. exception:: InvalidContractPrefix


   Bases: :py:obj:`ExceptionalHalt`