Spec for opcode ADDRESS

specs/opcode/30ADDRESS.md

@@ -0,0 +1,37 @@
+# ADDRESS opcode
+
+## Procedure
+
+The `ADDRESS` opcode gets the address of currently executing account.
+
+## EVM behaviour
+
+The `ADDRESS` opcode loads the callee address (20 bytes of data) from call
+context, then pushes this address to the stack.
+
+## Circuit behaviour
+
+1. Construct call context table in rw table
+2. Do busmapping lookup for call context callee read operation
+3. Do busmapping lookup for stack write operation
+
+## Constraints
+
+1. opId = 0x30
+2. State transition:
+   - gc + 2 (1 stack write, 1 call context read)
+   - stack_pointer - 1
+   - pc + 1
+   - gas - 2
+3. Lookups: 2
+   - `address` is in the rw table {call context, call ID, callee}
+   - `address` is on top of stack
+
+## Exceptions
+
+1. stack overflow: stack is full, stack pointer = 0
+2. out of gas: remaining gas is not enough
+
+## Code
+
+Please refer to `src/zkevm_specs/evm/execution/address.py`.

src/zkevm_specs/evm/execution/__init__.py

@@ -9,6 +9,7 @@
 # Opcode's successful cases
 from .add_sub import *
 from .addmod import *
+from .address import *
 from .mulmod import *
 from .block_ctx import *
 from .call import *
@@ -47,6 +48,7 @@
     ExecutionState.EndBlock: end_block,
     ExecutionState.ADD: add_sub,
     ExecutionState.ADDMOD: addmod,
+    ExecutionState.ADDRESS: address,
     ExecutionState.MULMOD: mulmod,
     ExecutionState.MUL: mul_div_mod,
     ExecutionState.NOT: not_opcode,

src/zkevm_specs/evm/execution/address.py

@@ -0,0 +1,24 @@
+from ...util import N_BYTES_ACCOUNT_ADDRESS
+from ..instruction import Instruction, Transition
+from ..table import CallContextFieldTag
+from ..opcode import Opcode
+
+
+def address(instruction: Instruction):
+    opcode = instruction.opcode_lookup(True)
+    instruction.constrain_equal(opcode, Opcode.ADDRESS)
+
+    # Get callee address from call context and compare with stack top after push.
+    instruction.constrain_equal(
+        instruction.call_context_lookup(CallContextFieldTag.CalleeAddress),
+        # NOTE: We can replace this with N_BYTES_WORD if we reuse the 32 byte RLC constraint in
+        # all places. See: https://github.com/privacy-scaling-explorations/zkevm-specs/issues/101
+        instruction.rlc_to_fq(instruction.stack_push(), N_BYTES_ACCOUNT_ADDRESS),
+    )
+
+    instruction.step_state_transition_in_same_context(
+        opcode,
+        rw_counter=Transition.delta(2),
+        program_counter=Transition.delta(1),
+        stack_pointer=Transition.delta(-1),
+    )

tests/evm/test_address.py

@@ -0,0 +1,70 @@
+import pytest
+
+from zkevm_specs.evm import (
+    Bytecode,
+    CallContextFieldTag,
+    ExecutionState,
+    RWDictionary,
+    StepState,
+    Tables,
+    verify_steps,
+)
+from zkevm_specs.util import RLC, U160, rand_address, rand_fq
+
+
+TESTING_DATA = (
+    0x00,
+    0x10,
+    0x030201,
+    0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF,
+    rand_address(),
+)
+
+
+@pytest.mark.parametrize("address", TESTING_DATA)
+def test_address(address: U160):
+    randomness = rand_fq()
+
+    bytecode = Bytecode().address()
+    bytecode_hash = RLC(bytecode.hash(), randomness)
+
+    tables = Tables(
+        block_table=set(),
+        tx_table=set(),
+        bytecode_table=set(bytecode.table_assignments(randomness)),
+        rw_table=set(
+            RWDictionary(9)
+            .call_context_read(1, CallContextFieldTag.CalleeAddress, address)
+            .stack_write(1, 1023, RLC(address, randomness))
+            .rws
+        ),
+    )
+
+    verify_steps(
+        randomness=randomness,
+        tables=tables,
+        steps=[
+            StepState(
+                execution_state=ExecutionState.ADDRESS,
+                rw_counter=9,
+                call_id=1,
+                is_root=True,
+                is_create=False,
+                code_hash=bytecode_hash,
+                program_counter=0,
+                stack_pointer=1024,
+                gas_left=2,
+            ),
+            StepState(
+                execution_state=ExecutionState.STOP,
+                rw_counter=11,
+                call_id=1,
+                is_root=True,
+                is_create=False,
+                code_hash=bytecode_hash,
+                program_counter=1,
+                stack_pointer=1023,
+                gas_left=0,
+            ),
+        ],
+    )