feat: implement deterministic proxies with CREATE2 and EIP1167 (#2460)

* feat: add create2 functionality to `create_forwarder_to`

* test: create2 forwarder to syntax

* test: add create2 fixture

* test: runtime create2

* fix: forgot a comma

* fix: remove is_deterministic kwarg

* docs: update create_forwarder_to, salt kwarg

* fix: rename boolean variable `is_deterministic` -> `should_use_create2`

stolen from charles, booleans affecting control flow, better to name them `should_*`

* fix: rename `create2` fixture -> `create2_address_of`

Author: skellet0r

docs/built-in-functions.rst

@@ -94,7 +94,7 @@ Bitwise Operations
 Chain Interaction
 =================
 
-.. py:function:: create_forwarder_to(target: address, value: uint256 = 0) -> address
+.. py:function:: create_forwarder_to(target: address, value: uint256 = 0[, salt: bytes32]) -> address
 
     Deploys a small contract that duplicates the logic of the contract at ``target``, but has it's own state since every call to ``target`` is made using ``DELEGATECALL`` to ``target``. To the end user, this should be indistinguishable from an independantly deployed contract with the same code as ``target``.
 
@@ -104,6 +104,7 @@ Chain Interaction
 
     * ``target``: Address of the contract to duplicate
     * ``value``: The wei value to send to the new contract address (Optional, default 0)
+    * ``salt``: A ``bytes32`` value utilized by the ``CREATE2`` opcode (Optional, if supplied deterministic deployment is done via ``CREATE2``)
 
     Returns the address of the duplicated contract.
 

tests/conftest.py

@@ -3,6 +3,7 @@
 
 import pytest
 from eth_tester import EthereumTester
+from hexbytes import HexBytes
 from web3 import Web3
 from web3.providers.eth_tester import EthereumTesterProvider
 
@@ -173,3 +174,15 @@ def search_for_sublist(lll, sublist):
         return False
 
     return search_for_sublist
+
+
+@pytest.fixture
+def create2_address_of(keccak):
+    def _f(_addr, _salt, _initcode):
+        prefix = HexBytes("0xff")
+        addr = HexBytes(_addr)
+        salt = HexBytes(_salt)
+        initcode = HexBytes(_initcode)
+        return keccak(prefix + addr + salt + keccak(initcode))[12:]
+
+    return _f

tests/parser/functions/test_create_with_code_of.py

@@ -1,3 +1,13 @@
+from hexbytes import HexBytes
+
+
+def initcode(_addr):
+    addr = HexBytes(_addr)
+    pre = HexBytes("0x602D3D8160093D39F3363d3d373d3d3d363d73")
+    post = HexBytes("0x5af43d82803e903d91602b57fd5bf3")
+    return HexBytes(pre + (addr + HexBytes(0) * (20 - len(addr))) + post)
+
+
 def test_create_forwarder_to_create(get_contract):
     code = """
 main: address
@@ -91,3 +101,19 @@ def test2(a: uint256) -> Bytes[100]:
 
     assert receipt["status"] == 0
     assert receipt["gasUsed"] < GAS_SENT
+
+
+def test_create2_forwarder_to_create(get_contract, create2_address_of, keccak):
+    code = """
+main: address
+
+@external
+def test(_salt: bytes32) -> address:
+    self.main = create_forwarder_to(self, salt=_salt)
+    return self.main
+    """
+
+    c = get_contract(code)
+
+    salt = keccak(b"vyper")
+    assert HexBytes(c.test(salt)) == create2_address_of(c.address, salt, initcode(c.address))

tests/parser/syntax/test_create_with_code_of.py

@@ -9,7 +9,14 @@
 @external
 def foo():
     x: address = create_forwarder_to(0x1234567890123456789012345678901234567890, value=4, value=9)
+    """,
     """
+@external
+def foo(_salt: bytes32):
+    x: address = create_forwarder_to(
+        0x1234567890123456789012345678901234567890, salt=keccak256(b"Vyper Rocks!"), salt=_salt
+    )
+    """,
 ]
 
 
@@ -38,6 +45,19 @@ def foo():
 def foo():
     x: address = create_forwarder_to(0x1234567890123456789012345678901234567890, value=9)
     """,
+    """
+@external
+def foo():
+    x: address = create_forwarder_to(
+        0x1234567890123456789012345678901234567890,
+        salt=keccak256(b"Vyper Rocks!")
+    )
+    """,
+    """
+@external
+def foo(_salt: bytes32):
+    x: address = create_forwarder_to(0x1234567890123456789012345678901234567890, salt=_salt)
+    """,
 ]
 
 

vyper/builtin_functions/functions.py

@@ -1012,6 +1012,7 @@ def build_LLL(self, expr, args, kwargs, context):
 
 
 zero_value = LLLnode.from_list(0, typ=BaseType("uint256"))
+empty_value = LLLnode.from_list(0, typ=BaseType("bytes32"))
 false_value = LLLnode.from_list(0, typ=BaseType("bool", is_literal=True))
 true_value = LLLnode.from_list(1, typ=BaseType("bool", is_literal=True))
 
@@ -1545,12 +1546,15 @@ class CreateForwarderTo(_SimpleBuiltinFunction):
 
     _id = "create_forwarder_to"
     _inputs = [("target", AddressDefinition())]
-    _kwargs = {"value": Optional("uint256", zero_value)}
+    _kwargs = {"value": Optional("uint256", zero_value), "salt": Optional("bytes32", empty_value)}
     _return_type = AddressDefinition()
 
     @validate_inputs
     def build_LLL(self, expr, args, kwargs, context):
         value = kwargs["value"]
+        salt = kwargs["salt"]
+        should_use_create2 = "salt" in [kwarg.arg for kwarg in expr.keywords]
+
         if context.is_constant():
             raise StateAccessViolation(
                 f"Cannot make calls from {context.pp_constancy()}", expr,
@@ -1572,13 +1576,20 @@ def build_LLL(self, expr, args, kwargs, context):
         else:
             target_address = ["mul", args[0], 2 ** 96]
 
+        op = "create"
+        op_args = [value, placeholder, preamble_length + 20 + len(forwarder_post_evm)]
+
+        if should_use_create2:
+            op = "create2"
+            op_args.append(salt)
+
         return LLLnode.from_list(
             [
                 "seq",
                 ["mstore", placeholder, forwarder_preamble],
                 ["mstore", ["add", placeholder, preamble_length], target_address],
                 ["mstore", ["add", placeholder, preamble_length + 20], forwarder_post],
-                ["create", value, placeholder, preamble_length + 20 + len(forwarder_post_evm)],
+                [op, *op_args],
             ],
             typ=BaseType("address"),
             pos=getpos(expr),