ethereum.forks.cancun.vm.instructions.blockethereum.forks.prague.vm.instructions.block

Ethereum Virtual Machine (EVM) Block Instructions.

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

Introduction

Implementations of the EVM block instructions.

block_hash

Push the hash of one of the 256 most recent complete blocks onto the stack. The block number to hash is present at the top of the stack.

Parameters

evm : The current EVM frame.

Raises

:py:class:~ethereum.forks.cancun.vm.exceptions.StackUnderflowError~ethereum.forks.prague.vm.exceptions.StackUnderflowError If len(stack) is less than 1. :py:class:~ethereum.forks.cancun.vm.exceptions.OutOfGasError~ethereum.forks.prague.vm.exceptions.OutOfGasError If evm.gas_left is less than 20.

def block_hash(​evm: Evm​) -> None:
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    <snip>
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    # STACK
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    block_number = Uint(pop(evm.stack))
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    # GAS
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    charge_gas(evm, GasCosts.OPCODE_BLOCKHASH)
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    # OPERATION
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    max_block_number = block_number + Uint(256)
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    current_block_number = evm.message.block_env.number
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    if (
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        current_block_number <= block_number
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        or current_block_number > max_block_number
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    ):
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        # Default hash to 0, if the block of interest is not yet on the chain
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        # (including the block which has the current executing transaction),
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        # or if the block's age is more than 256.
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        current_block_hash = b"\x00"
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    else:
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        current_block_hash = evm.message.block_env.block_hashes[
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            -(current_block_number - block_number)
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        ]
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    push(evm.stack, U256.from_be_bytes(current_block_hash))
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    # PROGRAM COUNTER
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    evm.pc += Uint(1)

coinbase

Push the current block's beneficiary address (address of the block miner) onto the stack.

Here the current block refers to the block in which the currently executing transaction/call resides.

Parameters

evm : The current EVM frame.

Raises

:py:class:~ethereum.forks.cancun.vm.exceptions.StackOverflowError~ethereum.forks.prague.vm.exceptions.StackOverflowError If len(stack) is equal to 1024. :py:class:~ethereum.forks.cancun.vm.exceptions.OutOfGasError~ethereum.forks.prague.vm.exceptions.OutOfGasError If evm.gas_left is less than 2.

def coinbase(​evm: Evm​) -> None:
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    <snip>
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    # STACK
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    pass
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    # GAS
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    charge_gas(evm, GasCosts.OPCODE_COINBASE)
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    # OPERATION
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    push(evm.stack, U256.from_be_bytes(evm.message.block_env.coinbase))
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    # PROGRAM COUNTER
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    evm.pc += Uint(1)

timestamp

Push the current block's timestamp onto the stack. Here the timestamp being referred to is actually the unix timestamp in seconds.

Here the current block refers to the block in which the currently executing transaction/call resides.

Parameters

evm : The current EVM frame.

Raises

:py:class:~ethereum.forks.cancun.vm.exceptions.StackOverflowError~ethereum.forks.prague.vm.exceptions.StackOverflowError If len(stack) is equal to 1024. :py:class:~ethereum.forks.cancun.vm.exceptions.OutOfGasError~ethereum.forks.prague.vm.exceptions.OutOfGasError If evm.gas_left is less than 2.

def timestamp(​evm: Evm​) -> None:
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    <snip>
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    # STACK
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    pass
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    # GAS
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    charge_gas(evm, GasCosts.OPCODE_TIMESTAMP)
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    # OPERATION
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    push(evm.stack, evm.message.block_env.time)
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    # PROGRAM COUNTER
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    evm.pc += Uint(1)

number

Push the current block's number onto the stack.

Here the current block refers to the block in which the currently executing transaction/call resides.

Parameters

evm : The current EVM frame.

Raises

:py:class:~ethereum.forks.cancun.vm.exceptions.StackOverflowError~ethereum.forks.prague.vm.exceptions.StackOverflowError If len(stack) is equal to 1024. :py:class:~ethereum.forks.cancun.vm.exceptions.OutOfGasError~ethereum.forks.prague.vm.exceptions.OutOfGasError If evm.gas_left is less than 2.

def number(​evm: Evm​) -> None:
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    <snip>
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    # STACK
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    pass
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    # GAS
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    charge_gas(evm, GasCosts.OPCODE_NUMBER)
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    # OPERATION
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    push(evm.stack, U256(evm.message.block_env.number))
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    # PROGRAM COUNTER
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    evm.pc += Uint(1)

prev_randao

Push the prev_randao value onto the stack.

The prev_randao value is the random output of the beacon chain's randomness oracle for the previous block.

Parameters

evm : The current EVM frame.

Raises

:py:class:~ethereum.forks.cancun.vm.exceptions.StackOverflowError~ethereum.forks.prague.vm.exceptions.StackOverflowError If len(stack) is equal to 1024. :py:class:~ethereum.forks.cancun.vm.exceptions.OutOfGasError~ethereum.forks.prague.vm.exceptions.OutOfGasError If evm.gas_left is less than 2.

def prev_randao(​evm: Evm​) -> None:
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    <snip>
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    # STACK
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    pass
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    # GAS
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    charge_gas(evm, GasCosts.OPCODE_PREVRANDAO)
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    # OPERATION
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    push(evm.stack, U256.from_be_bytes(evm.message.block_env.prev_randao))
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    # PROGRAM COUNTER
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    evm.pc += Uint(1)

gas_limit

Push the current block's gas limit onto the stack.

Here the current block refers to the block in which the currently executing transaction/call resides.

Parameters

evm : The current EVM frame.

Raises

:py:class:~ethereum.forks.cancun.vm.exceptions.StackOverflowError~ethereum.forks.prague.vm.exceptions.StackOverflowError If len(stack) is equal to 1024. :py:class:~ethereum.forks.cancun.vm.exceptions.OutOfGasError~ethereum.forks.prague.vm.exceptions.OutOfGasError If evm.gas_left is less than 2.

def gas_limit(​evm: Evm​) -> None:
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    <snip>
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    # STACK
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    pass
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    # GAS
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    charge_gas(evm, GasCosts.OPCODE_GASLIMIT)
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    # OPERATION
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    push(evm.stack, U256(evm.message.block_env.block_gas_limit))
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    # PROGRAM COUNTER
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    evm.pc += Uint(1)

chain_id

Push the chain id onto the stack.

Parameters

evm : The current EVM frame.

Raises

:py:class:~ethereum.forks.cancun.vm.exceptions.StackOverflowError~ethereum.forks.prague.vm.exceptions.StackOverflowError If len(stack) is equal to 1024. :py:class:~ethereum.forks.cancun.vm.exceptions.OutOfGasError~ethereum.forks.prague.vm.exceptions.OutOfGasError If evm.gas_left is less than 2.

def chain_id(​evm: Evm​) -> None:
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    <snip>
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    # STACK
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    pass
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    # GAS
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    charge_gas(evm, GasCosts.OPCODE_CHAINID)
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    # OPERATION
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    push(evm.stack, U256(evm.message.block_env.chain_id))
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    # PROGRAM COUNTER
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    evm.pc += Uint(1)