From 52ba355b657f34c11dd405057a76e46ac8fb9bab Mon Sep 17 00:00:00 2001
From: e-ngo <eric.ngo@consensys.net>
Date: Thu, 8 Aug 2019 23:30:52 -0700
Subject: [PATCH] Add logic for CREATE opcode, still need to add unit test for
 CREATE. Refactored extcodehash unit tests into separate test units.

---
 mythril/laser/ethereum/gas.py          |  5 +--
 mythril/laser/ethereum/instructions.py | 42 ++++++++++++++++++++++----
 tests/instructions/extcodehash_test.py | 34 ++++++++++++---------
 3 files changed, 56 insertions(+), 25 deletions(-)

diff --git a/mythril/laser/ethereum/gas.py b/mythril/laser/ethereum/gas.py
index 7e283d15..4d8de488 100644
--- a/mythril/laser/ethereum/gas.py
+++ b/mythril/laser/ethereum/gas.py
@@ -180,10 +180,7 @@ OPCODE_GAS = {
     "LOG3": (4 * 375, 4 * 375 + 8 * 32),
     "LOG4": (5 * 375, 5 * 375 + 8 * 32),
     "CREATE": (32000, 32000),
-    "CREATE2": (
-        32000,
-        32000,
-    ),  # TODO: The gas value is dynamic, to be done while implementing create2
+    "CREATE2": (32000, 32000),  # TODO: Make the gas value is dynamic
     "CALL": (700, 700 + 9000 + 25000),
     "NATIVE_COST": calculate_native_gas,
     "CALLCODE": (700, 700 + 9000 + 25000),
diff --git a/mythril/laser/ethereum/instructions.py b/mythril/laser/ethereum/instructions.py
index 1c663ded..35e98e0c 100644
--- a/mythril/laser/ethereum/instructions.py
+++ b/mythril/laser/ethereum/instructions.py
@@ -1605,12 +1605,42 @@ class Instruction:
         :param global_state:
         :return:
         """
-        # TODO: implement me
-        state = global_state.mstate
-        state.stack.pop(), state.stack.pop(), state.stack.pop()
-        # Not supported
-        state.stack.append(0)
-        return [global_state]
+        mstate = global_state.mstate
+        environment = global_state.environment
+        world_state = global_state.world_state
+
+        call_value, mem_offset, mem_size = (
+            mstate.stack.pop(),
+            mstate.stack.pop(),
+            mstate.stack.pop(),
+        )
+
+        try:
+            call_data = mstate.memory[
+                util.get_concrete_int(mem_offset) : util.get_concrete_int(
+                    mem_offset + mem_size
+                )
+            ]
+        except TypeError:
+            log.debug("Create with symbolic length or offset. Not supported")
+
+        caller = environment.sender
+        gas_price = environment.gasprice
+        origin = environment.origin
+        transaction = ContractCreationTransaction(
+            world_state=world_state,
+            caller=caller,
+            call_data=call_data,
+            gas_price=gas_price,
+            origin=origin,
+            call_value=call_value,
+        )
+
+        contract_address = transaction.callee_account.address
+
+        mstate.stack.append(contract_address)
+
+        raise TransactionStartSignal(transaction, self.op_code)
 
     @StateTransition()
     def create2_(self, global_state: GlobalState) -> List[GlobalState]:
diff --git a/tests/instructions/extcodehash_test.py b/tests/instructions/extcodehash_test.py
index e1ea30c1..14f2ad65 100644
--- a/tests/instructions/extcodehash_test.py
+++ b/tests/instructions/extcodehash_test.py
@@ -11,33 +11,37 @@ from mythril.support.support_utils import get_code_hash
 
 from mythril.laser.smt import symbol_factory
 
+# Arrange
+world_state = WorldState()
+account = world_state.create_account(balance=10, address=101)
+account.code = Disassembly("60606040")
+world_state.create_account(balance=10, address=1000)
+environment = Environment(account, None, None, None, None, None)
+og_state = GlobalState(world_state, environment, None, MachineState(gas_limit=8000000))
+og_state.transaction_stack.append(
+    (MessageCallTransaction(world_state=WorldState(), gas_limit=8000000), None)
+)
 
-def test_extcodehash_concrete():
-    # Arrange
-    world_state = WorldState()
-    account = world_state.create_account(balance=10, address=101)
-    account.code = Disassembly("60606040")
-    world_state.create_account(balance=10, address=1000)
-    environment = Environment(account, None, None, None, None, None)
-    og_state = GlobalState(
-        world_state, environment, None, MachineState(gas_limit=8000000)
-    )
-    og_state.transaction_stack.append(
-        (MessageCallTransaction(world_state=WorldState(), gas_limit=8000000), None)
-    )
-
-    instruction = Instruction("extcodehash", dynamic_loader=None)
+instruction = Instruction("extcodehash", dynamic_loader=None)
+
+
+def test_extcodehash_no_account():
 
     # If account does not exist, return 0
     og_state.mstate.stack = [symbol_factory.BitVecVal(1, 256)]
     new_state = instruction.evaluate(og_state)[0]
     assert new_state.mstate.stack[-1] == 0
 
+
+def test_extcodehash_no_code():
+
     # If account code does not exist, return hash of empty set.
     og_state.mstate.stack = [symbol_factory.BitVecVal(1000, 256)]
     new_state = instruction.evaluate(og_state)[0]
     assert hex(new_state.mstate.stack[-1].value) == get_code_hash("")
 
+
+def test_extcodehash_return_hash():
     # If account code exists, return hash of the code.
     og_state.mstate.stack = [symbol_factory.BitVecVal(101, 256)]
     new_state = instruction.evaluate(og_state)[0]