ethereum.homestead.vm.instructions.environment

Ethereum Virtual Machine (EVM) Environmental Instructions ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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

Introduction

Implementations of the EVM environment related instructions.

address

Pushes the address of the current executing account to the stack.

Parameters

evm : The current EVM frame.

def address(​evm: Evm​) -> None:
36
    """
37
    Pushes the address of the current executing account to the stack.
38
39
    Parameters
40
    ----------
41
    evm :
42
        The current EVM frame.
43
44
    """
45
    # STACK
46
    pass
47
48
    # GAS
49
    charge_gas(evm, GAS_BASE)
50
51
    # OPERATION
52
    push(evm.stack, U256.from_be_bytes(evm.message.current_target))
53
54
    # PROGRAM COUNTER
55
    evm.pc += Uint(1)

balance

Pushes the balance of the given account onto the stack.

Parameters

evm : The current EVM frame.

def balance(​evm: Evm​) -> None:
59
    """
60
    Pushes the balance of the given account onto the stack.
61
62
    Parameters
63
    ----------
64
    evm :
65
        The current EVM frame.
66
67
    """
68
    # STACK
69
    address = to_address(pop(evm.stack))
70
71
    # GAS
72
    charge_gas(evm, GAS_BALANCE)
73
74
    # OPERATION
75
    # Non-existent accounts default to EMPTY_ACCOUNT, which has balance 0.
76
    balance = get_account(evm.env.state, address).balance
77
78
    push(evm.stack, balance)
79
80
    # PROGRAM COUNTER
81
    evm.pc += Uint(1)

origin

Pushes the address of the original transaction sender to the stack. The origin address can only be an EOA.

Parameters

evm : The current EVM frame.

def origin(​evm: Evm​) -> None:
85
    """
86
    Pushes the address of the original transaction sender to the stack.
87
    The origin address can only be an EOA.
88
89
    Parameters
90
    ----------
91
    evm :
92
        The current EVM frame.
93
94
    """
95
    # STACK
96
    pass
97
98
    # GAS
99
    charge_gas(evm, GAS_BASE)
100
101
    # OPERATION
102
    push(evm.stack, U256.from_be_bytes(evm.env.origin))
103
104
    # PROGRAM COUNTER
105
    evm.pc += Uint(1)

caller

Pushes the address of the caller onto the stack.

Parameters

evm : The current EVM frame.

def caller(​evm: Evm​) -> None:
109
    """
110
    Pushes the address of the caller onto the stack.
111
112
    Parameters
113
    ----------
114
    evm :
115
        The current EVM frame.
116
117
    """
118
    # STACK
119
    pass
120
121
    # GAS
122
    charge_gas(evm, GAS_BASE)
123
124
    # OPERATION
125
    push(evm.stack, U256.from_be_bytes(evm.message.caller))
126
127
    # PROGRAM COUNTER
128
    evm.pc += Uint(1)

callvalue

Push the value (in wei) sent with the call onto the stack.

Parameters

evm : The current EVM frame.

def callvalue(​evm: Evm​) -> None:
132
    """
133
    Push the value (in wei) sent with the call onto the stack.
134
135
    Parameters
136
    ----------
137
    evm :
138
        The current EVM frame.
139
140
    """
141
    # STACK
142
    pass
143
144
    # GAS
145
    charge_gas(evm, GAS_BASE)
146
147
    # OPERATION
148
    push(evm.stack, evm.message.value)
149
150
    # PROGRAM COUNTER
151
    evm.pc += Uint(1)

calldataload

Push a word (32 bytes) of the input data belonging to the current environment onto the stack.

Parameters

evm : The current EVM frame.

def calldataload(​evm: Evm​) -> None:
155
    """
156
    Push a word (32 bytes) of the input data belonging to the current
157
    environment onto the stack.
158
159
    Parameters
160
    ----------
161
    evm :
162
        The current EVM frame.
163
164
    """
165
    # STACK
166
    start_index = pop(evm.stack)
167
168
    # GAS
169
    charge_gas(evm, GAS_VERY_LOW)
170
171
    # OPERATION
172
    value = buffer_read(evm.message.data, start_index, U256(32))
173
174
    push(evm.stack, U256.from_be_bytes(value))
175
176
    # PROGRAM COUNTER
177
    evm.pc += Uint(1)

calldatasize

Push the size of input data in current environment onto the stack.

Parameters

evm : The current EVM frame.

def calldatasize(​evm: Evm​) -> None:
181
    """
182
    Push the size of input data in current environment onto the stack.
183
184
    Parameters
185
    ----------
186
    evm :
187
        The current EVM frame.
188
189
    """
190
    # STACK
191
    pass
192
193
    # GAS
194
    charge_gas(evm, GAS_BASE)
195
196
    # OPERATION
197
    push(evm.stack, U256(len(evm.message.data)))
198
199
    # PROGRAM COUNTER
200
    evm.pc += Uint(1)

calldatacopy

Copy a portion of the input data in current environment to memory.

This will also expand the memory, in case that the memory is insufficient to store the data.

Parameters

evm : The current EVM frame.

def calldatacopy(​evm: Evm​) -> None:
204
    """
205
    Copy a portion of the input data in current environment to memory.
206
207
    This will also expand the memory, in case that the memory is insufficient
208
    to store the data.
209
210
    Parameters
211
    ----------
212
    evm :
213
        The current EVM frame.
214
215
    """
216
    # STACK
217
    memory_start_index = pop(evm.stack)
218
    data_start_index = pop(evm.stack)
219
    size = pop(evm.stack)
220
221
    # GAS
222
    words = ceil32(Uint(size)) // Uint(32)
223
    copy_gas_cost = GAS_COPY * words
224
    extend_memory = calculate_gas_extend_memory(
225
        evm.memory, [(memory_start_index, size)]
226
    )
227
    charge_gas(evm, GAS_VERY_LOW + copy_gas_cost + extend_memory.cost)
228
229
    # OPERATION
230
    evm.memory += b"\x00" * extend_memory.expand_by
231
    value = buffer_read(evm.message.data, data_start_index, size)
232
    memory_write(evm.memory, memory_start_index, value)
233
234
    # PROGRAM COUNTER
235
    evm.pc += Uint(1)

codesize

Push the size of code running in current environment onto the stack.

Parameters

evm : The current EVM frame.

def codesize(​evm: Evm​) -> None:
239
    """
240
    Push the size of code running in current environment onto the stack.
241
242
    Parameters
243
    ----------
244
    evm :
245
        The current EVM frame.
246
247
    """
248
    # STACK
249
    pass
250
251
    # GAS
252
    charge_gas(evm, GAS_BASE)
253
254
    # OPERATION
255
    push(evm.stack, U256(len(evm.code)))
256
257
    # PROGRAM COUNTER
258
    evm.pc += Uint(1)

codecopy

Copy a portion of the code in current environment to memory.

This will also expand the memory, in case that the memory is insufficient to store the data.

Parameters

evm : The current EVM frame.

def codecopy(​evm: Evm​) -> None:
262
    """
263
    Copy a portion of the code in current environment to memory.
264
265
    This will also expand the memory, in case that the memory is insufficient
266
    to store the data.
267
268
    Parameters
269
    ----------
270
    evm :
271
        The current EVM frame.
272
273
    """
274
    # STACK
275
    memory_start_index = pop(evm.stack)
276
    code_start_index = pop(evm.stack)
277
    size = pop(evm.stack)
278
279
    # GAS
280
    words = ceil32(Uint(size)) // Uint(32)
281
    copy_gas_cost = GAS_COPY * words
282
    extend_memory = calculate_gas_extend_memory(
283
        evm.memory, [(memory_start_index, size)]
284
    )
285
    charge_gas(evm, GAS_VERY_LOW + copy_gas_cost + extend_memory.cost)
286
287
    # OPERATION
288
    evm.memory += b"\x00" * extend_memory.expand_by
289
    value = buffer_read(evm.code, code_start_index, size)
290
    memory_write(evm.memory, memory_start_index, value)
291
292
    # PROGRAM COUNTER
293
    evm.pc += Uint(1)

gasprice

Push the gas price used in current environment onto the stack.

Parameters

evm : The current EVM frame.

def gasprice(​evm: Evm​) -> None:
297
    """
298
    Push the gas price used in current environment onto the stack.
299
300
    Parameters
301
    ----------
302
    evm :
303
        The current EVM frame.
304
305
    """
306
    # STACK
307
    pass
308
309
    # GAS
310
    charge_gas(evm, GAS_BASE)
311
312
    # OPERATION
313
    push(evm.stack, U256(evm.env.gas_price))
314
315
    # PROGRAM COUNTER
316
    evm.pc += Uint(1)

extcodesize

Push the code size of a given account onto the stack.

Parameters

evm : The current EVM frame.

def extcodesize(​evm: Evm​) -> None:
320
    """
321
    Push the code size of a given account onto the stack.
322
323
    Parameters
324
    ----------
325
    evm :
326
        The current EVM frame.
327
328
    """
329
    # STACK
330
    address = to_address(pop(evm.stack))
331
332
    # GAS
333
    charge_gas(evm, GAS_EXTERNAL)
334
335
    # OPERATION
336
    # Non-existent accounts default to EMPTY_ACCOUNT, which has empty code.
337
    codesize = U256(len(get_account(evm.env.state, address).code))
338
339
    push(evm.stack, codesize)
340
341
    # PROGRAM COUNTER
342
    evm.pc += Uint(1)

extcodecopy

Copy a portion of an account's code to memory.

Parameters

evm : The current EVM frame.

def extcodecopy(​evm: Evm​) -> None:
346
    """
347
    Copy a portion of an account's code to memory.
348
349
    Parameters
350
    ----------
351
    evm :
352
        The current EVM frame.
353
354
    """
355
    # STACK
356
    address = to_address(pop(evm.stack))
357
    memory_start_index = pop(evm.stack)
358
    code_start_index = pop(evm.stack)
359
    size = pop(evm.stack)
360
361
    # GAS
362
    words = ceil32(Uint(size)) // Uint(32)
363
    copy_gas_cost = GAS_COPY * words
364
    extend_memory = calculate_gas_extend_memory(
365
        evm.memory, [(memory_start_index, size)]
366
    )
367
    charge_gas(evm, GAS_EXTERNAL + copy_gas_cost + extend_memory.cost)
368
369
    # OPERATION
370
    evm.memory += b"\x00" * extend_memory.expand_by
371
    code = get_account(evm.env.state, address).code
372
    value = buffer_read(code, code_start_index, size)
373
    memory_write(evm.memory, memory_start_index, value)
374
375
    # PROGRAM COUNTER
376
    evm.pc += Uint(1)