ethereum.forks.homestead.vm.instructions.system
Ethereum Virtual Machine (EVM) System Instructions.
.. contents:: Table of Contents :backlinks: none :local:
Introduction
Implementations of the EVM system related instructions.
create ¶
Creates a new account with associated code.
Parameters
evm : The current EVM frame.
def create(evm: Evm) -> None:
| 45 | """ |
|---|---|
| 46 | Creates a new account with associated code. |
| 47 | |
| 48 | Parameters |
| 49 | ---------- |
| 50 | evm : |
| 51 | The current EVM frame. |
| 52 | |
| 53 | """ |
| 54 | # This import causes a circular import error |
| 55 | # if it's not moved inside this method |
| 56 | from ...vm.interpreter import STACK_DEPTH_LIMIT, process_create_message |
| 57 | |
| 58 | # STACK |
| 59 | endowment = pop(evm.stack) |
| 60 | memory_start_position = pop(evm.stack) |
| 61 | memory_size = pop(evm.stack) |
| 62 | |
| 63 | # GAS |
| 64 | extend_memory = calculate_gas_extend_memory( |
| 65 | evm.memory, [(memory_start_position, memory_size)] |
| 66 | ) |
| 67 | |
| 68 | charge_gas(evm, GasCosts.OPCODE_CREATE_BASE + extend_memory.cost) |
| 69 | |
| 70 | create_message_gas = evm.gas_left |
| 71 | evm.gas_left = Uint(0) |
| 72 | |
| 73 | # OPERATION |
| 74 | evm.memory += b"\x00" * extend_memory.expand_by |
| 75 | sender_address = evm.message.current_target |
| 76 | sender = get_account(evm.message.tx_env.state, sender_address) |
| 77 | |
| 78 | contract_address = compute_contract_address( |
| 79 | evm.message.current_target, |
| 80 | get_account( |
| 81 | evm.message.tx_env.state, evm.message.current_target |
| 82 | ).nonce, |
| 83 | ) |
| 84 | |
| 85 | if ( |
| 86 | sender.balance < endowment |
| 87 | or sender.nonce == Uint(2**64 - 1) |
| 88 | or evm.message.depth + Uint(1) > STACK_DEPTH_LIMIT |
| 89 | ): |
| 90 | push(evm.stack, U256(0)) |
| 91 | evm.gas_left += create_message_gas |
| 92 | elif account_has_code_or_nonce( |
| 93 | evm.message.tx_env.state, contract_address |
| 94 | ) or account_has_storage(evm.message.tx_env.state, contract_address): |
| 95 | increment_nonce(evm.message.tx_env.state, evm.message.current_target) |
| 96 | push(evm.stack, U256(0)) |
| 97 | else: |
| 98 | call_data = memory_read_bytes( |
| 99 | evm.memory, memory_start_position, memory_size |
| 100 | ) |
| 101 | |
| 102 | increment_nonce(evm.message.tx_env.state, evm.message.current_target) |
| 103 | |
| 104 | child_message = Message( |
| 105 | block_env=evm.message.block_env, |
| 106 | tx_env=evm.message.tx_env, |
| 107 | caller=evm.message.current_target, |
| 108 | target=Bytes0(), |
| 109 | gas=create_message_gas, |
| 110 | value=endowment, |
| 111 | data=b"", |
| 112 | code=call_data, |
| 113 | current_target=contract_address, |
| 114 | depth=evm.message.depth + Uint(1), |
| 115 | code_address=None, |
| 116 | should_transfer_value=True, |
| 117 | parent_evm=evm, |
| 118 | ) |
| 119 | child_evm = process_create_message(child_message) |
| 120 | |
| 121 | if child_evm.error: |
| 122 | incorporate_child_on_error(evm, child_evm) |
| 123 | push(evm.stack, U256(0)) |
| 124 | else: |
| 125 | incorporate_child_on_success(evm, child_evm) |
| 126 | push( |
| 127 | evm.stack, U256.from_be_bytes(child_evm.message.current_target) |
| 128 | ) |
| 129 | |
| 130 | # PROGRAM COUNTER |
| 131 | evm.pc += Uint(1) |
return_ ¶
Halts execution returning output data.
Parameters
evm : The current EVM frame.
def return_(evm: Evm) -> None:
| 135 | """ |
|---|---|
| 136 | Halts execution returning output data. |
| 137 | |
| 138 | Parameters |
| 139 | ---------- |
| 140 | evm : |
| 141 | The current EVM frame. |
| 142 | |
| 143 | """ |
| 144 | # STACK |
| 145 | memory_start_position = pop(evm.stack) |
| 146 | memory_size = pop(evm.stack) |
| 147 | |
| 148 | # GAS |
| 149 | extend_memory = calculate_gas_extend_memory( |
| 150 | evm.memory, [(memory_start_position, memory_size)] |
| 151 | ) |
| 152 | |
| 153 | charge_gas(evm, GasCosts.ZERO + extend_memory.cost) |
| 154 | |
| 155 | # OPERATION |
| 156 | evm.memory += b"\x00" * extend_memory.expand_by |
| 157 | evm.output = memory_read_bytes( |
| 158 | evm.memory, memory_start_position, memory_size |
| 159 | ) |
| 160 | |
| 161 | evm.running = False |
| 162 | |
| 163 | # PROGRAM COUNTER |
| 164 | pass |
generic_call ¶
Perform the core logic of the CALL* family of opcodes.
def generic_call(evm: Evm, gas: Uint, value: U256, caller: Address, to: Address, code_address: Address, should_transfer_value: bool, memory_input_start_position: U256, memory_input_size: U256, memory_output_start_position: U256, memory_output_size: U256) -> None:
| 180 | """ |
|---|---|
| 181 | Perform the core logic of the `CALL*` family of opcodes. |
| 182 | """ |
| 183 | from ...vm.interpreter import STACK_DEPTH_LIMIT, process_message |
| 184 | |
| 185 | if evm.message.depth + Uint(1) > STACK_DEPTH_LIMIT: |
| 186 | evm.gas_left += gas |
| 187 | push(evm.stack, U256(0)) |
| 188 | return |
| 189 | |
| 190 | call_data = memory_read_bytes( |
| 191 | evm.memory, memory_input_start_position, memory_input_size |
| 192 | ) |
| 193 | account_to_call = get_account(evm.message.tx_env.state, code_address) |
| 194 | code = get_code(evm.message.tx_env.state, account_to_call.code_hash) |
| 195 | child_message = Message( |
| 196 | block_env=evm.message.block_env, |
| 197 | tx_env=evm.message.tx_env, |
| 198 | caller=caller, |
| 199 | target=to, |
| 200 | gas=gas, |
| 201 | value=value, |
| 202 | data=call_data, |
| 203 | code=code, |
| 204 | current_target=to, |
| 205 | depth=evm.message.depth + Uint(1), |
| 206 | code_address=code_address, |
| 207 | should_transfer_value=should_transfer_value, |
| 208 | parent_evm=evm, |
| 209 | ) |
| 210 | child_evm = process_message(child_message) |
| 211 | |
| 212 | if child_evm.error: |
| 213 | incorporate_child_on_error(evm, child_evm) |
| 214 | push(evm.stack, U256(0)) |
| 215 | else: |
| 216 | incorporate_child_on_success(evm, child_evm) |
| 217 | push(evm.stack, U256(1)) |
| 218 | |
| 219 | actual_output_size = min(memory_output_size, U256(len(child_evm.output))) |
| 220 | memory_write( |
| 221 | evm.memory, |
| 222 | memory_output_start_position, |
| 223 | child_evm.output[:actual_output_size], |
| 224 | ) |
call ¶
Message-call into an account.
Parameters
evm : The current EVM frame.
def call(evm: Evm) -> None:
| 228 | """ |
|---|---|
| 229 | Message-call into an account. |
| 230 | |
| 231 | Parameters |
| 232 | ---------- |
| 233 | evm : |
| 234 | The current EVM frame. |
| 235 | |
| 236 | """ |
| 237 | # STACK |
| 238 | gas = Uint(pop(evm.stack)) |
| 239 | to = to_address_masked(pop(evm.stack)) |
| 240 | value = pop(evm.stack) |
| 241 | memory_input_start_position = pop(evm.stack) |
| 242 | memory_input_size = pop(evm.stack) |
| 243 | memory_output_start_position = pop(evm.stack) |
| 244 | memory_output_size = pop(evm.stack) |
| 245 | |
| 246 | # GAS |
| 247 | extend_memory = calculate_gas_extend_memory( |
| 248 | evm.memory, |
| 249 | [ |
| 250 | (memory_input_start_position, memory_input_size), |
| 251 | (memory_output_start_position, memory_output_size), |
| 252 | ], |
| 253 | ) |
| 254 | |
| 255 | code_address = to |
| 256 | |
| 257 | message_call_gas = calculate_message_call_gas( |
| 258 | evm.message.tx_env.state, gas, to, value |
| 259 | ) |
| 260 | charge_gas(evm, message_call_gas.cost + extend_memory.cost) |
| 261 | |
| 262 | # OPERATION |
| 263 | evm.memory += b"\x00" * extend_memory.expand_by |
| 264 | sender_balance = get_account( |
| 265 | evm.message.tx_env.state, evm.message.current_target |
| 266 | ).balance |
| 267 | if sender_balance < value: |
| 268 | push(evm.stack, U256(0)) |
| 269 | evm.gas_left += message_call_gas.sub_call |
| 270 | else: |
| 271 | generic_call( |
| 272 | evm, |
| 273 | message_call_gas.sub_call, |
| 274 | value, |
| 275 | evm.message.current_target, |
| 276 | to, |
| 277 | code_address, |
| 278 | True, |
| 279 | memory_input_start_position, |
| 280 | memory_input_size, |
| 281 | memory_output_start_position, |
| 282 | memory_output_size, |
| 283 | ) |
| 284 | |
| 285 | # PROGRAM COUNTER |
| 286 | evm.pc += Uint(1) |
callcode ¶
Message-call into this account with alternative account’s code.
Parameters
evm : The current EVM frame.
def callcode(evm: Evm) -> None:
| 290 | """ |
|---|---|
| 291 | Message-call into this account with alternative account’s code. |
| 292 | |
| 293 | Parameters |
| 294 | ---------- |
| 295 | evm : |
| 296 | The current EVM frame. |
| 297 | |
| 298 | """ |
| 299 | # STACK |
| 300 | gas = Uint(pop(evm.stack)) |
| 301 | code_address = to_address_masked(pop(evm.stack)) |
| 302 | value = pop(evm.stack) |
| 303 | memory_input_start_position = pop(evm.stack) |
| 304 | memory_input_size = pop(evm.stack) |
| 305 | memory_output_start_position = pop(evm.stack) |
| 306 | memory_output_size = pop(evm.stack) |
| 307 | |
| 308 | # GAS |
| 309 | to = evm.message.current_target |
| 310 | |
| 311 | extend_memory = calculate_gas_extend_memory( |
| 312 | evm.memory, |
| 313 | [ |
| 314 | (memory_input_start_position, memory_input_size), |
| 315 | (memory_output_start_position, memory_output_size), |
| 316 | ], |
| 317 | ) |
| 318 | message_call_gas = calculate_message_call_gas( |
| 319 | evm.message.tx_env.state, gas, to, value |
| 320 | ) |
| 321 | charge_gas(evm, message_call_gas.cost + extend_memory.cost) |
| 322 | |
| 323 | # OPERATION |
| 324 | evm.memory += b"\x00" * extend_memory.expand_by |
| 325 | sender_balance = get_account( |
| 326 | evm.message.tx_env.state, evm.message.current_target |
| 327 | ).balance |
| 328 | if sender_balance < value: |
| 329 | push(evm.stack, U256(0)) |
| 330 | evm.gas_left += message_call_gas.sub_call |
| 331 | else: |
| 332 | generic_call( |
| 333 | evm, |
| 334 | message_call_gas.sub_call, |
| 335 | value, |
| 336 | evm.message.current_target, |
| 337 | to, |
| 338 | code_address, |
| 339 | True, |
| 340 | memory_input_start_position, |
| 341 | memory_input_size, |
| 342 | memory_output_start_position, |
| 343 | memory_output_size, |
| 344 | ) |
| 345 | |
| 346 | # PROGRAM COUNTER |
| 347 | evm.pc += Uint(1) |
selfdestruct ¶
Halt execution and register account for later deletion.
Parameters
evm : The current EVM frame.
def selfdestruct(evm: Evm) -> None:
| 351 | """ |
|---|---|
| 352 | Halt execution and register account for later deletion. |
| 353 | |
| 354 | Parameters |
| 355 | ---------- |
| 356 | evm : |
| 357 | The current EVM frame. |
| 358 | |
| 359 | """ |
| 360 | # STACK |
| 361 | beneficiary = to_address_masked(pop(evm.stack)) |
| 362 | |
| 363 | # GAS |
| 364 | gas_cost = GasCosts.ZERO |
| 365 | |
| 366 | originator = evm.message.current_target |
| 367 | |
| 368 | refunded_accounts = evm.accounts_to_delete |
| 369 | parent_evm = evm.message.parent_evm |
| 370 | while parent_evm is not None: |
| 371 | refunded_accounts.update(parent_evm.accounts_to_delete) |
| 372 | parent_evm = parent_evm.message.parent_evm |
| 373 | |
| 374 | if originator not in refunded_accounts: |
| 375 | evm.refund_counter += int(GasCosts.REFUND_SELF_DESTRUCT) |
| 376 | |
| 377 | charge_gas(evm, gas_cost) |
| 378 | |
| 379 | # OPERATION |
| 380 | beneficiary_balance = get_account( |
| 381 | evm.message.tx_env.state, beneficiary |
| 382 | ).balance |
| 383 | originator_balance = get_account( |
| 384 | evm.message.tx_env.state, originator |
| 385 | ).balance |
| 386 | |
| 387 | # First Transfer to beneficiary |
| 388 | set_account_balance( |
| 389 | evm.message.tx_env.state, |
| 390 | beneficiary, |
| 391 | beneficiary_balance + originator_balance, |
| 392 | ) |
| 393 | # Next, Zero the balance of the address being deleted (must come after |
| 394 | # sending to beneficiary in case the contract named itself as the |
| 395 | # beneficiary). |
| 396 | set_account_balance(evm.message.tx_env.state, originator, U256(0)) |
| 397 | |
| 398 | # register account for deletion |
| 399 | evm.accounts_to_delete.add(originator) |
| 400 | |
| 401 | # HALT the execution |
| 402 | evm.running = False |
| 403 | |
| 404 | # PROGRAM COUNTER |
| 405 | pass |
delegatecall ¶
Message-call into an account.
Parameters
evm : The current EVM frame.
def delegatecall(evm: Evm) -> None:
| 409 | """ |
|---|---|
| 410 | Message-call into an account. |
| 411 | |
| 412 | Parameters |
| 413 | ---------- |
| 414 | evm : |
| 415 | The current EVM frame. |
| 416 | |
| 417 | """ |
| 418 | # STACK |
| 419 | gas = Uint(pop(evm.stack)) |
| 420 | code_address = to_address_masked(pop(evm.stack)) |
| 421 | memory_input_start_position = pop(evm.stack) |
| 422 | memory_input_size = pop(evm.stack) |
| 423 | memory_output_start_position = pop(evm.stack) |
| 424 | memory_output_size = pop(evm.stack) |
| 425 | |
| 426 | # GAS |
| 427 | extend_memory = calculate_gas_extend_memory( |
| 428 | evm.memory, |
| 429 | [ |
| 430 | (memory_input_start_position, memory_input_size), |
| 431 | (memory_output_start_position, memory_output_size), |
| 432 | ], |
| 433 | ) |
| 434 | charge_gas(evm, GasCosts.OPCODE_CALL_BASE + gas + extend_memory.cost) |
| 435 | |
| 436 | # OPERATION |
| 437 | evm.memory += b"\x00" * extend_memory.expand_by |
| 438 | generic_call( |
| 439 | evm, |
| 440 | gas, |
| 441 | evm.message.value, |
| 442 | evm.message.caller, |
| 443 | evm.message.current_target, |
| 444 | code_address, |
| 445 | False, |
| 446 | memory_input_start_position, |
| 447 | memory_input_size, |
| 448 | memory_output_start_position, |
| 449 | memory_output_size, |
| 450 | ) |
| 451 | |
| 452 | # PROGRAM COUNTER |
| 453 | evm.pc += Uint(1) |