ethereum.forks.constantinople.vm.instructions.system

Ethereum Virtual Machine (EVM) System Instructions.

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

Introduction

Implementations of the EVM system related instructions.

generic_create

Core logic used by the CREATE* family of opcodes.

def generic_create(​evm: Evm, ​​endowment: U256, ​​contract_address: Address, ​​memory_start_position: U256, ​​memory_size: U256​) -> None:
62
    <snip>
65
    # This import causes a circular import error
66
    # if it's not moved inside this method
67
    from ...vm.interpreter import STACK_DEPTH_LIMIT, process_create_message
68
69
    call_data = memory_read_bytes(
70
        evm.memory, memory_start_position, memory_size
71
    )
72
73
    create_message_gas = max_message_call_gas(Uint(evm.gas_left))
74
    evm.gas_left -= create_message_gas
75
    if evm.message.is_static:
76
        raise WriteInStaticContext
77
    evm.return_data = b""
78
79
    sender_address = evm.message.current_target
80
    sender = get_account(evm.message.tx_env.state, sender_address)
81
82
    if (
83
        sender.balance < endowment
84
        or sender.nonce == Uint(2**64 - 1)
85
        or evm.message.depth + Uint(1) > STACK_DEPTH_LIMIT
86
    ):
87
        evm.gas_left += create_message_gas
88
        push(evm.stack, U256(0))
89
        return
90
91
    if not account_deployable(evm.message.tx_env.state, contract_address):
92
        increment_nonce(evm.message.tx_env.state, evm.message.current_target)
93
        push(evm.stack, U256(0))
94
        return
95
96
    call_data = memory_read_bytes(
97
        evm.memory, memory_start_position, memory_size
98
    )
99
100
    increment_nonce(evm.message.tx_env.state, evm.message.current_target)
101
102
    child_message = Message(
103
        block_env=evm.message.block_env,
104
        tx_env=evm.message.tx_env,
105
        caller=evm.message.current_target,
106
        target=Bytes0(),
107
        gas=create_message_gas,
108
        value=endowment,
109
        data=b"",
110
        code=call_data,
111
        current_target=contract_address,
112
        depth=evm.message.depth + Uint(1),
113
        code_address=None,
114
        should_transfer_value=True,
115
        is_static=False,
116
        parent_evm=evm,
117
    )
118
    child_evm = process_create_message(child_message)
119
120
    if child_evm.error:
121
        incorporate_child_on_error(evm, child_evm)
122
        evm.return_data = child_evm.output
123
        push(evm.stack, U256(0))
124
    else:
125
        incorporate_child_on_success(evm, child_evm)
126
        evm.return_data = b""
127
        push(evm.stack, U256.from_be_bytes(child_evm.message.current_target))

create

Creates a new account with associated code.

Parameters

evm : The current EVM frame.

def create(​evm: Evm​) -> None:
131
    <snip>
140
    # STACK
141
    endowment = pop(evm.stack)
142
    memory_start_position = pop(evm.stack)
143
    memory_size = pop(evm.stack)
144
145
    # GAS
146
    extend_memory = calculate_gas_extend_memory(
147
        evm.memory, [(memory_start_position, memory_size)]
148
    )
149
150
    charge_gas(evm, GasCosts.OPCODE_CREATE_BASE + extend_memory.cost)
151
152
    # OPERATION
153
    evm.memory += b"\x00" * extend_memory.expand_by
154
    contract_address = compute_contract_address(
155
        evm.message.current_target,
156
        get_account(
157
            evm.message.tx_env.state, evm.message.current_target
158
        ).nonce,
159
    )
160
161
    generic_create(
162
        evm,
163
        endowment,
164
        contract_address,
165
        memory_start_position,
166
        memory_size,
167
    )
168
169
    # PROGRAM COUNTER
170
    evm.pc += Uint(1)

create2

Creates a new account with associated code.

It's similar to the CREATE opcode except that the address of the new account depends on the init_code instead of the nonce of sender.

Parameters

evm : The current EVM frame.

def create2(​evm: Evm​) -> None:
174
    <snip>
186
    # STACK
187
    endowment = pop(evm.stack)
188
    memory_start_position = pop(evm.stack)
189
    memory_size = pop(evm.stack)
190
    salt = pop(evm.stack).to_be_bytes32()
191
192
    # GAS
193
    extend_memory = calculate_gas_extend_memory(
194
        evm.memory, [(memory_start_position, memory_size)]
195
    )
196
    call_data_words = ceil32(Uint(memory_size)) // Uint(32)
197
    charge_gas(
198
        evm,
199
        GasCosts.OPCODE_CREATE_BASE
200
        + GasCosts.OPCODE_KECCAK256_PER_WORD * call_data_words
201
        + extend_memory.cost,
202
    )
203
204
    # OPERATION
205
    evm.memory += b"\x00" * extend_memory.expand_by
206
    contract_address = compute_create2_contract_address(
207
        evm.message.current_target,
208
        salt,
209
        memory_read_bytes(evm.memory, memory_start_position, memory_size),
210
    )
211
212
    generic_create(
213
        evm,
214
        endowment,
215
        contract_address,
216
        memory_start_position,
217
        memory_size,
218
    )
219
220
    # PROGRAM COUNTER
221
    evm.pc += Uint(1)

return_

Halts execution returning output data.

Parameters

evm : The current EVM frame.

def return_(​evm: Evm​) -> None:
225
    <snip>
234
    # STACK
235
    memory_start_position = pop(evm.stack)
236
    memory_size = pop(evm.stack)
237
238
    # GAS
239
    extend_memory = calculate_gas_extend_memory(
240
        evm.memory, [(memory_start_position, memory_size)]
241
    )
242
243
    charge_gas(evm, GasCosts.ZERO + extend_memory.cost)
244
245
    # OPERATION
246
    evm.memory += b"\x00" * extend_memory.expand_by
247
    evm.output = memory_read_bytes(
248
        evm.memory, memory_start_position, memory_size
249
    )
250
251
    evm.running = False
252
253
    # PROGRAM COUNTER
254
    pass

GenericCall

Parameters for the core logic of the CALL* family of opcodes.

257
@final
258
@dataclass
class GenericCall:

gas

264
    gas: Uint

value

265
    value: U256

caller

266
    caller: Address

to

267
    to: Address

code_address

268
    code_address: Address

should_transfer_value

269
    should_transfer_value: bool

is_staticcall

270
    is_staticcall: bool

memory_input_start_position

271
    memory_input_start_position: U256

memory_input_size

272
    memory_input_size: U256

memory_output_start_position

273
    memory_output_start_position: U256

memory_output_size

274
    memory_output_size: U256

generic_call

Perform the core logic of the CALL* family of opcodes.

def generic_call(​evm: Evm, ​​params: GenericCall​) -> None:
278
    <snip>
281
    from ...vm.interpreter import STACK_DEPTH_LIMIT, process_message
282
283
    evm.return_data = b""
284
285
    if evm.message.depth + Uint(1) > STACK_DEPTH_LIMIT:
286
        evm.gas_left += params.gas
287
        push(evm.stack, U256(0))
288
        return
289
290
    call_data = memory_read_bytes(
291
        evm.memory,
292
        params.memory_input_start_position,
293
        params.memory_input_size,
294
    )
295
    account = get_account(evm.message.tx_env.state, params.code_address)
296
    code = get_code(evm.message.tx_env.state, account.code_hash)
297
    child_message = Message(
298
        block_env=evm.message.block_env,
299
        tx_env=evm.message.tx_env,
300
        caller=params.caller,
301
        target=params.to,
302
        gas=params.gas,
303
        value=params.value,
304
        data=call_data,
305
        code=code,
306
        current_target=params.to,
307
        depth=evm.message.depth + Uint(1),
308
        code_address=params.code_address,
309
        should_transfer_value=params.should_transfer_value,
310
        is_static=params.is_staticcall or evm.message.is_static,
311
        parent_evm=evm,
312
    )
313
    child_evm = process_message(child_message)
314
315
    if child_evm.error:
316
        incorporate_child_on_error(evm, child_evm)
317
        evm.return_data = child_evm.output
318
        push(evm.stack, U256(0))
319
    else:
320
        incorporate_child_on_success(evm, child_evm)
321
        evm.return_data = child_evm.output
322
        push(evm.stack, U256(1))
323
324
    actual_output_size = min(
325
        params.memory_output_size, U256(len(child_evm.output))
326
    )
327
    memory_write(
328
        evm.memory,
329
        params.memory_output_start_position,
330
        child_evm.output[:actual_output_size],
331
    )

call

Message-call into an account.

Parameters

evm : The current EVM frame.

def call(​evm: Evm​) -> None:
335
    <snip>
344
    # STACK
345
    gas = Uint(pop(evm.stack))
346
    to = to_address_masked(pop(evm.stack))
347
    value = pop(evm.stack)
348
    memory_input_start_position = pop(evm.stack)
349
    memory_input_size = pop(evm.stack)
350
    memory_output_start_position = pop(evm.stack)
351
    memory_output_size = pop(evm.stack)
352
353
    # GAS
354
    extend_memory = calculate_gas_extend_memory(
355
        evm.memory,
356
        [
357
            (memory_input_start_position, memory_input_size),
358
            (memory_output_start_position, memory_output_size),
359
        ],
360
    )
361
362
    code_address = to
363
364
    create_gas_cost = GasCosts.NEW_ACCOUNT
365
    if value == 0 or is_account_alive(evm.message.tx_env.state, to):
366
        create_gas_cost = Uint(0)
367
    transfer_gas_cost = Uint(0) if value == 0 else GasCosts.CALL_VALUE
368
    message_call_gas = calculate_message_call_gas(
369
        value,
370
        gas,
371
        Uint(evm.gas_left),
372
        memory_cost=extend_memory.cost,
373
        extra_gas=GasCosts.OPCODE_CALL_BASE
374
        + create_gas_cost
375
        + transfer_gas_cost,
376
    )
377
    charge_gas(evm, message_call_gas.cost + extend_memory.cost)
378
    if evm.message.is_static and value != U256(0):
379
        raise WriteInStaticContext
380
    evm.memory += b"\x00" * extend_memory.expand_by
381
    sender_balance = get_account(
382
        evm.message.tx_env.state, evm.message.current_target
383
    ).balance
384
    if sender_balance < value:
385
        push(evm.stack, U256(0))
386
        evm.return_data = b""
387
        evm.gas_left += message_call_gas.sub_call
388
    else:
389
        generic_call(
390
            evm,
391
            GenericCall(
392
                gas=message_call_gas.sub_call,
393
                value=value,
394
                caller=evm.message.current_target,
395
                to=to,
396
                code_address=code_address,
397
                should_transfer_value=True,
398
                is_staticcall=False,
399
                memory_input_start_position=memory_input_start_position,
400
                memory_input_size=memory_input_size,
401
                memory_output_start_position=memory_output_start_position,
402
                memory_output_size=memory_output_size,
403
            ),
404
        )
405
406
    # PROGRAM COUNTER
407
    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:
411
    <snip>
420
    # STACK
421
    gas = Uint(pop(evm.stack))
422
    code_address = to_address_masked(pop(evm.stack))
423
    value = pop(evm.stack)
424
    memory_input_start_position = pop(evm.stack)
425
    memory_input_size = pop(evm.stack)
426
    memory_output_start_position = pop(evm.stack)
427
    memory_output_size = pop(evm.stack)
428
429
    # GAS
430
    to = evm.message.current_target
431
432
    extend_memory = calculate_gas_extend_memory(
433
        evm.memory,
434
        [
435
            (memory_input_start_position, memory_input_size),
436
            (memory_output_start_position, memory_output_size),
437
        ],
438
    )
439
    transfer_gas_cost = Uint(0) if value == 0 else GasCosts.CALL_VALUE
440
    message_call_gas = calculate_message_call_gas(
441
        value,
442
        gas,
443
        Uint(evm.gas_left),
444
        extend_memory.cost,
445
        GasCosts.OPCODE_CALL_BASE + transfer_gas_cost,
446
    )
447
    charge_gas(evm, message_call_gas.cost + extend_memory.cost)
448
449
    # OPERATION
450
    evm.memory += b"\x00" * extend_memory.expand_by
451
    sender_balance = get_account(
452
        evm.message.tx_env.state, evm.message.current_target
453
    ).balance
454
    if sender_balance < value:
455
        push(evm.stack, U256(0))
456
        evm.return_data = b""
457
        evm.gas_left += message_call_gas.sub_call
458
    else:
459
        generic_call(
460
            evm,
461
            GenericCall(
462
                gas=message_call_gas.sub_call,
463
                value=value,
464
                caller=evm.message.current_target,
465
                to=to,
466
                code_address=code_address,
467
                should_transfer_value=True,
468
                is_staticcall=False,
469
                memory_input_start_position=memory_input_start_position,
470
                memory_input_size=memory_input_size,
471
                memory_output_start_position=memory_output_start_position,
472
                memory_output_size=memory_output_size,
473
            ),
474
        )
475
476
    # PROGRAM COUNTER
477
    evm.pc += Uint(1)

selfdestruct

Halt execution and register account for later deletion.

Parameters

evm : The current EVM frame.

def selfdestruct(​evm: Evm​) -> None:
481
    <snip>
490
    # STACK
491
    beneficiary = to_address_masked(pop(evm.stack))
492
493
    # GAS
494
    gas_cost = GasCosts.OPCODE_SELFDESTRUCT_BASE
495
    if (
496
        not is_account_alive(evm.message.tx_env.state, beneficiary)
497
        and get_account(
498
            evm.message.tx_env.state, evm.message.current_target
499
        ).balance
500
        != 0
501
    ):
502
        gas_cost += GasCosts.OPCODE_SELFDESTRUCT_NEW_ACCOUNT
503
504
    originator = evm.message.current_target
505
506
    refunded_accounts = evm.accounts_to_delete
507
    parent_evm = evm.message.parent_evm
508
    while parent_evm is not None:
509
        refunded_accounts.update(parent_evm.accounts_to_delete)
510
        parent_evm = parent_evm.message.parent_evm
511
512
    if originator not in refunded_accounts:
513
        evm.refund_counter += GasCosts.REFUND_SELF_DESTRUCT
514
515
    charge_gas(evm, gas_cost)
516
    if evm.message.is_static:
517
        raise WriteInStaticContext
518
519
    originator = evm.message.current_target
520
    beneficiary_balance = get_account(
521
        evm.message.tx_env.state, beneficiary
522
    ).balance
523
    originator_balance = get_account(
524
        evm.message.tx_env.state, originator
525
    ).balance
526
527
    # First Transfer to beneficiary
528
    set_account_balance(
529
        evm.message.tx_env.state,
530
        beneficiary,
531
        beneficiary_balance + originator_balance,
532
    )
533
    # Next, Zero the balance of the address being deleted (must come after
534
    # sending to beneficiary in case the contract named itself as the
535
    # beneficiary).
536
    set_account_balance(evm.message.tx_env.state, originator, U256(0))
537
538
    # register account for deletion
539
    evm.accounts_to_delete.add(originator)
540
541
    # mark beneficiary as touched
542
    if account_exists_and_is_empty(evm.message.tx_env.state, beneficiary):
543
        evm.touched_accounts.add(beneficiary)
544
545
    # HALT the execution
546
    evm.running = False
547
548
    # PROGRAM COUNTER
549
    pass

delegatecall

Message-call into an account.

Parameters

evm : The current EVM frame.

def delegatecall(​evm: Evm​) -> None:
553
    <snip>
562
    # STACK
563
    gas = Uint(pop(evm.stack))
564
    code_address = to_address_masked(pop(evm.stack))
565
    memory_input_start_position = pop(evm.stack)
566
    memory_input_size = pop(evm.stack)
567
    memory_output_start_position = pop(evm.stack)
568
    memory_output_size = pop(evm.stack)
569
570
    # GAS
571
    extend_memory = calculate_gas_extend_memory(
572
        evm.memory,
573
        [
574
            (memory_input_start_position, memory_input_size),
575
            (memory_output_start_position, memory_output_size),
576
        ],
577
    )
578
    message_call_gas = calculate_message_call_gas(
579
        U256(0),
580
        gas,
581
        Uint(evm.gas_left),
582
        extend_memory.cost,
583
        GasCosts.OPCODE_CALL_BASE,
584
    )
585
    charge_gas(evm, message_call_gas.cost + extend_memory.cost)
586
587
    # OPERATION
588
    evm.memory += b"\x00" * extend_memory.expand_by
589
    generic_call(
590
        evm,
591
        GenericCall(
592
            gas=message_call_gas.sub_call,
593
            value=evm.message.value,
594
            caller=evm.message.caller,
595
            to=evm.message.current_target,
596
            code_address=code_address,
597
            should_transfer_value=False,
598
            is_staticcall=False,
599
            memory_input_start_position=memory_input_start_position,
600
            memory_input_size=memory_input_size,
601
            memory_output_start_position=memory_output_start_position,
602
            memory_output_size=memory_output_size,
603
        ),
604
    )
605
606
    # PROGRAM COUNTER
607
    evm.pc += Uint(1)

staticcall

Message-call into an account.

Parameters

evm : The current EVM frame.

def staticcall(​evm: Evm​) -> None:
611
    <snip>
620
    # STACK
621
    gas = Uint(pop(evm.stack))
622
    to = to_address_masked(pop(evm.stack))
623
    memory_input_start_position = pop(evm.stack)
624
    memory_input_size = pop(evm.stack)
625
    memory_output_start_position = pop(evm.stack)
626
    memory_output_size = pop(evm.stack)
627
628
    # GAS
629
    extend_memory = calculate_gas_extend_memory(
630
        evm.memory,
631
        [
632
            (memory_input_start_position, memory_input_size),
633
            (memory_output_start_position, memory_output_size),
634
        ],
635
    )
636
637
    code_address = to
638
639
    message_call_gas = calculate_message_call_gas(
640
        U256(0),
641
        gas,
642
        Uint(evm.gas_left),
643
        extend_memory.cost,
644
        GasCosts.OPCODE_CALL_BASE,
645
    )
646
    charge_gas(evm, message_call_gas.cost + extend_memory.cost)
647
648
    # OPERATION
649
    evm.memory += b"\x00" * extend_memory.expand_by
650
    generic_call(
651
        evm,
652
        GenericCall(
653
            gas=message_call_gas.sub_call,
654
            value=U256(0),
655
            caller=evm.message.current_target,
656
            to=to,
657
            code_address=code_address,
658
            should_transfer_value=True,
659
            is_staticcall=True,
660
            memory_input_start_position=memory_input_start_position,
661
            memory_input_size=memory_input_size,
662
            memory_output_start_position=memory_output_start_position,
663
            memory_output_size=memory_output_size,
664
        ),
665
    )
666
667
    # PROGRAM COUNTER
668
    evm.pc += Uint(1)

revert

Stop execution and revert state changes, without consuming all provided gas and also has the ability to return a reason.

Parameters

evm : The current EVM frame.

def revert(​evm: Evm​) -> None:
672
    <snip>
682
    # STACK
683
    memory_start_index = pop(evm.stack)
684
    size = pop(evm.stack)
685
686
    # GAS
687
    extend_memory = calculate_gas_extend_memory(
688
        evm.memory, [(memory_start_index, size)]
689
    )
690
691
    charge_gas(evm, extend_memory.cost)
692
693
    # OPERATION
694
    evm.memory += b"\x00" * extend_memory.expand_by
695
    output = memory_read_bytes(evm.memory, memory_start_index, size)
696
    evm.output = Bytes(output)
697
    raise Revert
698
699
    # PROGRAM COUNTER
700
    # no-op