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:
67
    """
68
    Core logic used by the `CREATE*` family of opcodes.
69
    """
70
    # This import causes a circular import error
71
    # if it's not moved inside this method
72
    from ...vm.interpreter import STACK_DEPTH_LIMIT, process_create_message
73
74
    call_data = memory_read_bytes(
75
        evm.memory, memory_start_position, memory_size
76
    )
77
78
    create_message_gas = max_message_call_gas(Uint(evm.gas_left))
79
    evm.gas_left -= create_message_gas
80
    if evm.message.is_static:
81
        raise WriteInStaticContext
82
    evm.return_data = b""
83
84
    sender_address = evm.message.current_target
85
    sender = get_account(evm.message.block_env.state, sender_address)
86
87
    if (
88
        sender.balance < endowment
89
        or sender.nonce == Uint(2**64 - 1)
90
        or evm.message.depth + Uint(1) > STACK_DEPTH_LIMIT
91
    ):
92
        evm.gas_left += create_message_gas
93
        push(evm.stack, U256(0))
94
        return
95
96
    if account_has_code_or_nonce(
97
        evm.message.block_env.state, contract_address
98
    ) or account_has_storage(evm.message.block_env.state, contract_address):
99
        increment_nonce(
100
            evm.message.block_env.state, evm.message.current_target
101
        )
102
        push(evm.stack, U256(0))
103
        return
104
105
    call_data = memory_read_bytes(
106
        evm.memory, memory_start_position, memory_size
107
    )
108
109
    increment_nonce(evm.message.block_env.state, evm.message.current_target)
110
111
    child_message = Message(
112
        block_env=evm.message.block_env,
113
        tx_env=evm.message.tx_env,
114
        caller=evm.message.current_target,
115
        target=Bytes0(),
116
        gas=create_message_gas,
117
        value=endowment,
118
        data=b"",
119
        code=call_data,
120
        current_target=contract_address,
121
        depth=evm.message.depth + Uint(1),
122
        code_address=None,
123
        should_transfer_value=True,
124
        is_static=False,
125
        parent_evm=evm,
126
    )
127
    child_evm = process_create_message(child_message)
128
129
    if child_evm.error:
130
        incorporate_child_on_error(evm, child_evm)
131
        evm.return_data = child_evm.output
132
        push(evm.stack, U256(0))
133
    else:
134
        incorporate_child_on_success(evm, child_evm)
135
        evm.return_data = b""
136
        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:
140
    """
141
    Creates a new account with associated code.
142
143
    Parameters
144
    ----------
145
    evm :
146
        The current EVM frame.
147
148
    """
149
    # STACK
150
    endowment = pop(evm.stack)
151
    memory_start_position = pop(evm.stack)
152
    memory_size = pop(evm.stack)
153
154
    # GAS
155
    extend_memory = calculate_gas_extend_memory(
156
        evm.memory, [(memory_start_position, memory_size)]
157
    )
158
159
    charge_gas(evm, GAS_CREATE + extend_memory.cost)
160
161
    # OPERATION
162
    evm.memory += b"\x00" * extend_memory.expand_by
163
    contract_address = compute_contract_address(
164
        evm.message.current_target,
165
        get_account(
166
            evm.message.block_env.state, evm.message.current_target
167
        ).nonce,
168
    )
169
170
    generic_create(
171
        evm, endowment, contract_address, memory_start_position, memory_size
172
    )
173
174
    # PROGRAM COUNTER
175
    evm.pc += Uint(1)

create2

Creates a new account with associated code.

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

Parameters

evm : The current EVM frame.

def create2(​evm: Evm​) -> None:
179
    """
180
    Creates a new account with associated code.
181
182
    It's similar to CREATE opcode except that the address of new account
183
    depends on the init_code instead of the nonce of sender.
184
185
    Parameters
186
    ----------
187
    evm :
188
        The current EVM frame.
189
190
    """
191
    # STACK
192
    endowment = pop(evm.stack)
193
    memory_start_position = pop(evm.stack)
194
    memory_size = pop(evm.stack)
195
    salt = pop(evm.stack).to_be_bytes32()
196
197
    # GAS
198
    extend_memory = calculate_gas_extend_memory(
199
        evm.memory, [(memory_start_position, memory_size)]
200
    )
201
    call_data_words = ceil32(Uint(memory_size)) // Uint(32)
202
    charge_gas(
203
        evm,
204
        GAS_CREATE + GAS_KECCAK256_WORD * call_data_words + extend_memory.cost,
205
    )
206
207
    # OPERATION
208
    evm.memory += b"\x00" * extend_memory.expand_by
209
    contract_address = compute_create2_contract_address(
210
        evm.message.current_target,
211
        salt,
212
        memory_read_bytes(evm.memory, memory_start_position, memory_size),
213
    )
214
215
    generic_create(
216
        evm, endowment, contract_address, memory_start_position, memory_size
217
    )
218
219
    # PROGRAM COUNTER
220
    evm.pc += Uint(1)

return_

Halts execution returning output data.

Parameters

evm : The current EVM frame.

def return_(​evm: Evm​) -> None:
224
    """
225
    Halts execution returning output data.
226
227
    Parameters
228
    ----------
229
    evm :
230
        The current EVM frame.
231
232
    """
233
    # STACK
234
    memory_start_position = pop(evm.stack)
235
    memory_size = pop(evm.stack)
236
237
    # GAS
238
    extend_memory = calculate_gas_extend_memory(
239
        evm.memory, [(memory_start_position, memory_size)]
240
    )
241
242
    charge_gas(evm, GAS_ZERO + extend_memory.cost)
243
244
    # OPERATION
245
    evm.memory += b"\x00" * extend_memory.expand_by
246
    evm.output = memory_read_bytes(
247
        evm.memory, memory_start_position, memory_size
248
    )
249
250
    evm.running = False
251
252
    # PROGRAM COUNTER
253
    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, ​​is_staticcall: bool, ​​memory_input_start_position: U256, ​​memory_input_size: U256, ​​memory_output_start_position: U256, ​​memory_output_size: U256​) -> None:
270
    """
271
    Perform the core logic of the `CALL*` family of opcodes.
272
    """
273
    from ...vm.interpreter import STACK_DEPTH_LIMIT, process_message
274
275
    evm.return_data = b""
276
277
    if evm.message.depth + Uint(1) > STACK_DEPTH_LIMIT:
278
        evm.gas_left += gas
279
        push(evm.stack, U256(0))
280
        return
281
282
    call_data = memory_read_bytes(
283
        evm.memory, memory_input_start_position, memory_input_size
284
    )
285
    code = get_account(evm.message.block_env.state, code_address).code
286
    child_message = Message(
287
        block_env=evm.message.block_env,
288
        tx_env=evm.message.tx_env,
289
        caller=caller,
290
        target=to,
291
        gas=gas,
292
        value=value,
293
        data=call_data,
294
        code=code,
295
        current_target=to,
296
        depth=evm.message.depth + Uint(1),
297
        code_address=code_address,
298
        should_transfer_value=should_transfer_value,
299
        is_static=True if is_staticcall else evm.message.is_static,
300
        parent_evm=evm,
301
    )
302
    child_evm = process_message(child_message)
303
304
    if child_evm.error:
305
        incorporate_child_on_error(evm, child_evm)
306
        evm.return_data = child_evm.output
307
        push(evm.stack, U256(0))
308
    else:
309
        incorporate_child_on_success(evm, child_evm)
310
        evm.return_data = child_evm.output
311
        push(evm.stack, U256(1))
312
313
    actual_output_size = min(memory_output_size, U256(len(child_evm.output)))
314
    memory_write(
315
        evm.memory,
316
        memory_output_start_position,
317
        child_evm.output[:actual_output_size],
318
    )

call

Message-call into an account.

Parameters

evm : The current EVM frame.

def call(​evm: Evm​) -> None:
322
    """
323
    Message-call into an account.
324
325
    Parameters
326
    ----------
327
    evm :
328
        The current EVM frame.
329
330
    """
331
    # STACK
332
    gas = Uint(pop(evm.stack))
333
    to = to_address_masked(pop(evm.stack))
334
    value = pop(evm.stack)
335
    memory_input_start_position = pop(evm.stack)
336
    memory_input_size = pop(evm.stack)
337
    memory_output_start_position = pop(evm.stack)
338
    memory_output_size = pop(evm.stack)
339
340
    # GAS
341
    extend_memory = calculate_gas_extend_memory(
342
        evm.memory,
343
        [
344
            (memory_input_start_position, memory_input_size),
345
            (memory_output_start_position, memory_output_size),
346
        ],
347
    )
348
349
    code_address = to
350
351
    create_gas_cost = GAS_NEW_ACCOUNT
352
    if value == 0 or is_account_alive(evm.message.block_env.state, to):
353
        create_gas_cost = Uint(0)
354
    transfer_gas_cost = Uint(0) if value == 0 else GAS_CALL_VALUE
355
    message_call_gas = calculate_message_call_gas(
356
        value,
357
        gas,
358
        Uint(evm.gas_left),
359
        extend_memory.cost,
360
        GAS_CALL + create_gas_cost + transfer_gas_cost,
361
    )
362
    charge_gas(evm, message_call_gas.cost + extend_memory.cost)
363
    if evm.message.is_static and value != U256(0):
364
        raise WriteInStaticContext
365
    evm.memory += b"\x00" * extend_memory.expand_by
366
    sender_balance = get_account(
367
        evm.message.block_env.state, evm.message.current_target
368
    ).balance
369
    if sender_balance < value:
370
        push(evm.stack, U256(0))
371
        evm.return_data = b""
372
        evm.gas_left += message_call_gas.sub_call
373
    else:
374
        generic_call(
375
            evm,
376
            message_call_gas.sub_call,
377
            value,
378
            evm.message.current_target,
379
            to,
380
            code_address,
381
            True,
382
            False,
383
            memory_input_start_position,
384
            memory_input_size,
385
            memory_output_start_position,
386
            memory_output_size,
387
        )
388
389
    # PROGRAM COUNTER
390
    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:
394
    """
395
    Message-call into this account with alternative account’s code.
396
397
    Parameters
398
    ----------
399
    evm :
400
        The current EVM frame.
401
402
    """
403
    # STACK
404
    gas = Uint(pop(evm.stack))
405
    code_address = to_address_masked(pop(evm.stack))
406
    value = pop(evm.stack)
407
    memory_input_start_position = pop(evm.stack)
408
    memory_input_size = pop(evm.stack)
409
    memory_output_start_position = pop(evm.stack)
410
    memory_output_size = pop(evm.stack)
411
412
    # GAS
413
    to = evm.message.current_target
414
415
    extend_memory = calculate_gas_extend_memory(
416
        evm.memory,
417
        [
418
            (memory_input_start_position, memory_input_size),
419
            (memory_output_start_position, memory_output_size),
420
        ],
421
    )
422
    transfer_gas_cost = Uint(0) if value == 0 else GAS_CALL_VALUE
423
    message_call_gas = calculate_message_call_gas(
424
        value,
425
        gas,
426
        Uint(evm.gas_left),
427
        extend_memory.cost,
428
        GAS_CALL + transfer_gas_cost,
429
    )
430
    charge_gas(evm, message_call_gas.cost + extend_memory.cost)
431
432
    # OPERATION
433
    evm.memory += b"\x00" * extend_memory.expand_by
434
    sender_balance = get_account(
435
        evm.message.block_env.state, evm.message.current_target
436
    ).balance
437
    if sender_balance < value:
438
        push(evm.stack, U256(0))
439
        evm.return_data = b""
440
        evm.gas_left += message_call_gas.sub_call
441
    else:
442
        generic_call(
443
            evm,
444
            message_call_gas.sub_call,
445
            value,
446
            evm.message.current_target,
447
            to,
448
            code_address,
449
            True,
450
            False,
451
            memory_input_start_position,
452
            memory_input_size,
453
            memory_output_start_position,
454
            memory_output_size,
455
        )
456
457
    # PROGRAM COUNTER
458
    evm.pc += Uint(1)

selfdestruct

Halt execution and register account for later deletion.

Parameters

evm : The current EVM frame.

def selfdestruct(​evm: Evm​) -> None:
462
    """
463
    Halt execution and register account for later deletion.
464
465
    Parameters
466
    ----------
467
    evm :
468
        The current EVM frame.
469
470
    """
471
    # STACK
472
    beneficiary = to_address_masked(pop(evm.stack))
473
474
    # GAS
475
    gas_cost = GAS_SELF_DESTRUCT
476
    if (
477
        not is_account_alive(evm.message.block_env.state, beneficiary)
478
        and get_account(
479
            evm.message.block_env.state, evm.message.current_target
480
        ).balance
481
        != 0
482
    ):
483
        gas_cost += GAS_SELF_DESTRUCT_NEW_ACCOUNT
484
485
    originator = evm.message.current_target
486
487
    refunded_accounts = evm.accounts_to_delete
488
    parent_evm = evm.message.parent_evm
489
    while parent_evm is not None:
490
        refunded_accounts.update(parent_evm.accounts_to_delete)
491
        parent_evm = parent_evm.message.parent_evm
492
493
    if originator not in refunded_accounts:
494
        evm.refund_counter += REFUND_SELF_DESTRUCT
495
496
    charge_gas(evm, gas_cost)
497
    if evm.message.is_static:
498
        raise WriteInStaticContext
499
500
    originator = evm.message.current_target
501
    beneficiary_balance = get_account(
502
        evm.message.block_env.state, beneficiary
503
    ).balance
504
    originator_balance = get_account(
505
        evm.message.block_env.state, originator
506
    ).balance
507
508
    # First Transfer to beneficiary
509
    set_account_balance(
510
        evm.message.block_env.state,
511
        beneficiary,
512
        beneficiary_balance + originator_balance,
513
    )
514
    # Next, Zero the balance of the address being deleted (must come after
515
    # sending to beneficiary in case the contract named itself as the
516
    # beneficiary).
517
    set_account_balance(evm.message.block_env.state, originator, U256(0))
518
519
    # register account for deletion
520
    evm.accounts_to_delete.add(originator)
521
522
    # mark beneficiary as touched
523
    if account_exists_and_is_empty(evm.message.block_env.state, beneficiary):
524
        evm.touched_accounts.add(beneficiary)
525
526
    # HALT the execution
527
    evm.running = False
528
529
    # PROGRAM COUNTER
530
    pass

delegatecall

Message-call into an account.

Parameters

evm : The current EVM frame.

def delegatecall(​evm: Evm​) -> None:
534
    """
535
    Message-call into an account.
536
537
    Parameters
538
    ----------
539
    evm :
540
        The current EVM frame.
541
542
    """
543
    # STACK
544
    gas = Uint(pop(evm.stack))
545
    code_address = to_address_masked(pop(evm.stack))
546
    memory_input_start_position = pop(evm.stack)
547
    memory_input_size = pop(evm.stack)
548
    memory_output_start_position = pop(evm.stack)
549
    memory_output_size = pop(evm.stack)
550
551
    # GAS
552
    extend_memory = calculate_gas_extend_memory(
553
        evm.memory,
554
        [
555
            (memory_input_start_position, memory_input_size),
556
            (memory_output_start_position, memory_output_size),
557
        ],
558
    )
559
    message_call_gas = calculate_message_call_gas(
560
        U256(0), gas, Uint(evm.gas_left), extend_memory.cost, GAS_CALL
561
    )
562
    charge_gas(evm, message_call_gas.cost + extend_memory.cost)
563
564
    # OPERATION
565
    evm.memory += b"\x00" * extend_memory.expand_by
566
    generic_call(
567
        evm,
568
        message_call_gas.sub_call,
569
        evm.message.value,
570
        evm.message.caller,
571
        evm.message.current_target,
572
        code_address,
573
        False,
574
        False,
575
        memory_input_start_position,
576
        memory_input_size,
577
        memory_output_start_position,
578
        memory_output_size,
579
    )
580
581
    # PROGRAM COUNTER
582
    evm.pc += Uint(1)

staticcall

Message-call into an account.

Parameters

evm : The current EVM frame.

def staticcall(​evm: Evm​) -> None:
586
    """
587
    Message-call into an account.
588
589
    Parameters
590
    ----------
591
    evm :
592
        The current EVM frame.
593
594
    """
595
    # STACK
596
    gas = Uint(pop(evm.stack))
597
    to = to_address_masked(pop(evm.stack))
598
    memory_input_start_position = pop(evm.stack)
599
    memory_input_size = pop(evm.stack)
600
    memory_output_start_position = pop(evm.stack)
601
    memory_output_size = pop(evm.stack)
602
603
    # GAS
604
    extend_memory = calculate_gas_extend_memory(
605
        evm.memory,
606
        [
607
            (memory_input_start_position, memory_input_size),
608
            (memory_output_start_position, memory_output_size),
609
        ],
610
    )
611
612
    code_address = to
613
614
    message_call_gas = calculate_message_call_gas(
615
        U256(0),
616
        gas,
617
        Uint(evm.gas_left),
618
        extend_memory.cost,
619
        GAS_CALL,
620
    )
621
    charge_gas(evm, message_call_gas.cost + extend_memory.cost)
622
623
    # OPERATION
624
    evm.memory += b"\x00" * extend_memory.expand_by
625
    generic_call(
626
        evm,
627
        message_call_gas.sub_call,
628
        U256(0),
629
        evm.message.current_target,
630
        to,
631
        code_address,
632
        True,
633
        True,
634
        memory_input_start_position,
635
        memory_input_size,
636
        memory_output_start_position,
637
        memory_output_size,
638
    )
639
640
    # PROGRAM COUNTER
641
    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:
645
    """
646
    Stop execution and revert state changes, without consuming all provided gas
647
    and also has the ability to return a reason.
648
649
    Parameters
650
    ----------
651
    evm :
652
        The current EVM frame.
653
654
    """
655
    # STACK
656
    memory_start_index = pop(evm.stack)
657
    size = pop(evm.stack)
658
659
    # GAS
660
    extend_memory = calculate_gas_extend_memory(
661
        evm.memory, [(memory_start_index, size)]
662
    )
663
664
    charge_gas(evm, extend_memory.cost)
665
666
    # OPERATION
667
    evm.memory += b"\x00" * extend_memory.expand_by
668
    output = memory_read_bytes(evm.memory, memory_start_index, size)
669
    evm.output = Bytes(output)
670
    raise Revert