Py35 support (#1233)

* Add py35 into tox

* Use solcx for python3.6+

* Fix tests

mythril/ethereum/util.py

@@ -2,8 +2,8 @@
 solc integration."""
 import binascii
 import json
+import sys
 import os
-import solcx
 from pathlib import Path
 from subprocess import PIPE, Popen
 
@@ -12,6 +12,9 @@ from ethereum.utils import zpad
 
 from mythril.exceptions import CompilerError
 
+if sys.version_info[1] >= 6:
+    import solcx
+
 
 def safe_decode(hex_encoded_string):
     """
@@ -128,10 +131,9 @@ def solc_exists(version):
                 "bin/solc",
             )  # py-solc setup
         ]
-    else:
+    elif sys.version_info[1] >= 6:
         # we are using solc-x for the the 0.5 and higher
         solc_binaries = [os.path.join(solcx.__path__[0], "bin", "solc-v" + version)]
-
     for solc_path in solc_binaries:
         if os.path.exists(solc_path):
             return solc_path

mythril/mythril/mythril_disassembler.py

@@ -1,7 +1,7 @@
 import logging
 import re
 import solc
-import solcx
+import sys
 import os
 
 from ethereum import utils
@@ -14,6 +14,9 @@ from mythril.ethereum.evmcontract import EVMContract
 from mythril.ethereum.interface.rpc.exceptions import ConnectionError
 from mythril.solidity.soliditycontract import SolidityContract, get_contracts_from_file
 
+if sys.version_info[1] >= 6:
+    import solcx
+
 log = logging.getLogger(__name__)
 
 
@@ -67,23 +70,30 @@ class MythrilDisassembler:
             ):
                 log.info("Given version is already installed")
             else:
-                try:
-                    if version.startswith("0.4"):
+                if version.startswith("0.4"):
+                    try:
                         solc.install_solc("v" + version)
-                    else:
+                    except solc.exceptions.SolcError:
+                        raise CriticalError(
+                            "There was an error when trying to install the specified solc version"
+                        )
+                elif sys.version_info[1] >= 6:
+                    # solcx supports python 3.6+
+                    try:
                         solcx.install_solc("v" + version)
-                    solc_binary = util.solc_exists(version)
-                    if not solc_binary:
-                        raise solc.exceptions.SolcError()
-                except solc.exceptions.SolcError:
-                    raise CriticalError(
-                        "There was an error when trying to install the specified solc version"
-                    )
-                except solcx.exceptions.SolcError:
+                    except solcx.exceptions.SolcError:
+                        raise CriticalError(
+                            "There was an error when trying to install the specified solc version"
+                        )
+                else:
                     raise CriticalError(
-                        "There was an error when trying to install the specified solc version"
+                        "Py-Solc doesn't support 0.5.*. You can switch to python 3.6 which uses solcx."
                     )
 
+                solc_binary = util.solc_exists(version)
+                if not solc_binary:
+                    raise solc.exceptions.SolcError()
+
             log.info("Setting the compiler to %s", solc_binary)
 
         return solc_binary

tests/laser/transaction/create_transaction_test.py

@@ -11,10 +11,7 @@ from mythril.analysis.symbolic import SymExecWrapper
 
 
 def test_create():
-    contract = SolidityContract(
-        str(tests.TESTDATA_INPUTS_CONTRACTS / "calls.sol"),
-        solc_binary=MythrilDisassembler._init_solc_binary("0.5.0"),
-    )
+    contract = SolidityContract(str(tests.TESTDATA_INPUTS_CONTRACTS / "calls.sol"))
 
     laser_evm = svm.LaserEVM({})
 
@@ -35,10 +32,7 @@ def test_create():
 
 
 def test_sym_exec():
-    contract = SolidityContract(
-        str(tests.TESTDATA_INPUTS_CONTRACTS / "calls.sol"),
-        solc_binary=MythrilDisassembler._init_solc_binary("0.5.0"),
-    )
+    contract = SolidityContract(str(tests.TESTDATA_INPUTS_CONTRACTS / "calls.sol"))
 
     sym = SymExecWrapper(
         contract,

tests/native_test.py

@@ -78,10 +78,7 @@ class NativeTests(BaseTestCase):
         """"""
         # The solidity version (0.5.3 at the moment) should be kept in sync with
         # pragma in ./tests/native_tests.sol
-        disassembly = SolidityContract(
-            "./tests/native_tests.sol",
-            solc_binary=MythrilDisassembler._init_solc_binary("0.5.3"),
-        ).disassembly
+        disassembly = SolidityContract("./tests/native_tests.sol").disassembly
         account = Account("0x0000000000000000000000000000000000000000", disassembly)
         world_state = WorldState()
         world_state.put_account(account)

tests/solidity_contract_test.py

@@ -10,9 +10,7 @@ TEST_FILES = Path(__file__).parent / "testdata/input_contracts"
 class SolidityContractTest(BaseTestCase):
     def test_get_source_info_without_name_gets_latest_contract_info(self):
         input_file = TEST_FILES / "multi_contracts.sol"
-        contract = SolidityContract(
-            str(input_file), solc_binary=MythrilDisassembler._init_solc_binary("0.5.0")
-        )
+        contract = SolidityContract(str(input_file))
 
         code_info = contract.get_source_info(142)
 
@@ -22,11 +20,7 @@ class SolidityContractTest(BaseTestCase):
 
     def test_get_source_info_with_contract_name_specified(self):
         input_file = TEST_FILES / "multi_contracts.sol"
-        contract = SolidityContract(
-            str(input_file),
-            name="Transfer1",
-            solc_binary=MythrilDisassembler._init_solc_binary("0.5.0"),
-        )
+        contract = SolidityContract(str(input_file), name="Transfer1")
 
         code_info = contract.get_source_info(142)
 
@@ -36,11 +30,7 @@ class SolidityContractTest(BaseTestCase):
 
     def test_get_source_info_with_contract_name_specified_constructor(self):
         input_file = TEST_FILES / "constructor_assert.sol"
-        contract = SolidityContract(
-            str(input_file),
-            name="AssertFail",
-            solc_binary=MythrilDisassembler._init_solc_binary("0.5.0"),
-        )
+        contract = SolidityContract(str(input_file), name="AssertFail")
 
         code_info = contract.get_source_info(70, constructor=True)
 

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py36
+envlist = py35, py36
 
 [testenv]
 deps =