API Reference¶

evmasm¶

class pyevmasm.evmasm.Instruction(opcode, name, operand_size, pops, pushes, fee, description, operand=None, pc=0)¶

bytes¶: Encoded instruction

description¶: Colloquial description of the instruction

fee¶: The basic gas fee of the instruction

group¶: Instruction classification as per the yellow paper

has_operand¶: True if the instruction uses an immediate operand

is_arithmetic¶: True if the instruction is an arithmetic operation

is_branch¶: True if the instruction is a jump

is_endtx¶: True if the instruction is a transaction terminator

is_environmental¶: True if the instruction access enviromental data

is_starttx¶: True if the instruction is a transaction initiator

is_system¶: True if the instruction is a system operation

is_terminator¶: True if the instruction is a basic block terminator

mnemonic¶: Alias for name

name¶: The instruction name/mnemonic

opcode¶: The opcode as an integer

operand_size¶: The immediate operand size

parse_operand(buf)¶

Parses an operand from buf

Parameters:	buf (iterator/generator/string) – a buffer

pops¶: Number words popped from the stack

pushes¶: Number words pushed to the stack

reads_from_memory¶: True if the instruction reads from memory

reads_from_stack¶: True if the instruction reads from stack

reads_from_storage¶: True if the instruction reads from the storage

semantics¶: Canonical semantics

size¶: Size of the encoded instruction

uses_block_info¶: True if the instruction access block information

uses_stack¶: True if the instruction reads/writes from/to the stack

writes_to_memory¶: True if the instruction writes to memory

writes_to_stack¶: True if the instruction writes to the stack

writes_to_storage¶: True if the instruction writes to the storage

class pyevmasm.evmasm.InstructionTable(*args, **kwargs)¶

EVM Instruction factory: Implements an immutable, iterable instruction LUT that can be indexed by both mnemonic or opcode.

Example:

>>> from pyevmasm import instruction_table
>>> instruction_table[0]
Instruction(0x0, 'STOP', 0, 0, 0, 0, 'Halts execution.', None, 0)
>>> instruction_table['STOP']
Instruction(0x0, 'STOP', 0, 0, 0, 0, 'Halts execution.', None, 0)
>>> i = instruction_table.__iter__()
>>> i.__next__()
Instruction(0x0, 'STOP', 0, 0, 0, 0, 'Halts execution.', None, 0)
>>> i.__next__()
Instruction(0x1, 'ADD', 0, 2, 1, 3, 'Addition operation.', None, 0)
>>> i.__next__()
Instruction(0x2, 'MUL', 0, 2, 1, 5, 'Multiplication operation.', None, 0)
>>> i.__next__()
Instruction(0x3, 'SUB', 0, 2, 1, 3, 'Subtraction operation.', None, 0)

exception pyevmasm.evmasm.UnknownMnemonicError¶

exception pyevmasm.evmasm.UnknownOpcodeError¶

pyevmasm.evmasm.assemble(asmcode, pc=0)¶

Assemble an EVM program

Parameters:	asmcode (str) – an evm assembler program pc (int) – program counter of the first instruction(optional)
Returns:	the hex representation of the bytecode
Return type:	str

Example use:

>>> assemble('''PUSH1 0x60
                        BLOCKHASH
                        MSTORE
                        PUSH1 0x2
                        PUSH2 0x100
                     ''')
...
b"```@R`a"

pyevmasm.evmasm.assemble_all(asmcode, pc=0)¶

Assemble a sequence of textual representation of EVM instructions

Parameters:	asmcode (str) – assembly code for any number of instructions pc (int) – program counter of the first instruction(optional)
Returns:	An generator of Instruction objects
Return type:	generator[Instructions]

Example use:

>>> assemble_one('''PUSH1 0x60
                 PUSH1 0x40
                 MSTORE
                 PUSH1 0x2
                 PUSH2 0x108
                 PUSH1 0x0
                 POP
                 SSTORE
                 PUSH1 0x40
                 MLOAD
                 ''')

pyevmasm.evmasm.assemble_hex(asmcode, pc=0)¶

Assemble an EVM program

Parameters:	asmcode (str \| iterator[Instruction]) – an evm assembler program pc (int) – program counter of the first instruction(optional)
Returns:	the hex representation of the bytecode
Return type:	str

Example use:

>>> assemble_hex('''PUSH1 0x60
                            BLOCKHASH
                            MSTORE
                            PUSH1 0x2
                            PUSH2 0x100
                         ''')
...
"0x6060604052600261010"

pyevmasm.evmasm.assemble_one(asmcode, pc=0)¶

Assemble one EVM instruction from its textual representation.

Parameters:	asmcode (str) – assembly code for one instruction pc (int) – program counter of the instruction(optional)
Returns:	An Instruction object
Return type:	Instruction

Example use:

>>> print assemble_one('LT')

pyevmasm.evmasm.disassemble(bytecode, pc=0)¶

Disassemble an EVM bytecode

Parameters:	bytecode (str \| bytes \| bytearray) – binary representation of an evm bytecode pc (int) – program counter of the first instruction(optional)
Returns:	the text representation of the assembler code

Example use:

>>> disassemble("```@R`a")
...
PUSH1 0x60
BLOCKHASH
MSTORE
PUSH1 0x2
PUSH2 0x100

pyevmasm.evmasm.disassemble_all(bytecode, pc=0)¶

Disassemble all instructions in bytecode

Parameters:	bytecode (str \| bytes \| bytearray \| iterator) – an evm bytecode (binary) pc (int) – program counter of the first instruction(optional)
Returns:	An generator of Instruction objects
Return type:	list[Instruction]

Example use:

>>> for inst in disassemble_all(bytecode):
...    print(instr)

...
PUSH1 0x60
PUSH1 0x40
MSTORE
PUSH1 0x2
PUSH2 0x108
PUSH1 0x0
POP
SSTORE
PUSH1 0x40
MLOAD

pyevmasm.evmasm.disassemble_hex(bytecode, pc=0)¶

Disassemble an EVM bytecode

Parameters:	bytecode (str) – canonical representation of an evm bytecode (hexadecimal) pc (int) – program counter of the first instruction(optional)
Returns:	the text representation of the assembler code
Return type:	str

Example use:

>>> disassemble_hex("0x6060604052600261010")
...
PUSH1 0x60
BLOCKHASH
MSTORE
PUSH1 0x2
PUSH2 0x100

pyevmasm.evmasm.disassemble_one(bytecode, pc=0)¶

Disassemble a single instruction from a bytecode

Parameters:	bytecode (str \| bytes \| bytearray \| iterator) – the bytecode stream pc (int) – program counter of the instruction(optional)
Returns:	an Instruction object
Return type:	Instruction

Example use:

>>> print disassemble_one('`')

pyevmasm.evmasm.instruction¶: Instance of InstructionTable for EVM. (see; InstructionTable)

API Reference¶

evmasm¶

pyevmasm

Navigation

Related Topics