Fixing py-solc-x usage to automatically download or compile correct solc binary and use it (#1425)

* Fixed cases where multiple versions of solc is needed on the system, and the default version installed isn't the version required.

* Fixed setup.py

* black

* Bump semver requirement

* Put mythril_disassembler.py version check into util.py

* Pruning ethereum/util.py

* Provide for cases where --solv is used with a v before the version.

mythril/ethereum/util.py

@@ -4,13 +4,15 @@ import binascii
 import json
 import sys
 import os
+import platform
 from pathlib import Path
 from subprocess import PIPE, Popen
-
+import solc
 from ethereum.abi import encode_abi, encode_int, method_id
 from ethereum.utils import zpad
 
 from mythril.exceptions import CompilerError
+from semantic_version import Version
 
 if sys.version_info[1] >= 6:
     import solcx
@@ -124,7 +126,30 @@ def solc_exists(version):
     """
 
     solc_binaries = []
-    if version.startswith("0.4"):
+    default_binary = "/usr/bin/solc"
+    if sys.version_info[1] >= 6:
+        if platform.system() == "Darwin":
+            solcx.import_installed_solc()
+        installed = solcx.get_installed_solc_versions()
+        if "v" + version in installed:
+            solcx.set_solc_version("v" + version)
+            solc_binary = solcx.install.get_executable()
+            return solc_binary
+        else:
+            available = solcx.get_available_solc_versions()
+            if "v" + version in available:
+                solcx.install_solc("v" + version)
+                solcx.set_solc_version("v" + version)
+                solc_binary = solcx.install.get_executable()
+                return solc_binary
+            elif Version("0.4.2") <= Version(version) <= Version("0.4.9"):
+                return None
+    elif Version("0.4.2") <= Version(version) <= Version("0.4.25"):
+        if not solc.main.is_solc_available():
+            solc.install_solc("v" + version)
+            solc_binary = solc.install.get_executable_path("v" + version)
+            return solc_binary
+        else:
             solc_binaries = [
                 os.path.join(
                     os.environ.get("HOME", str(Path.home())),
@@ -135,14 +160,8 @@ def solc_exists(version):
             for solc_path in solc_binaries:
                 if os.path.exists(solc_path):
                     return solc_path
-    elif sys.version_info[1] >= 6:
-        # we are using solc-x for the the 0.5 and higher
-        try:
-            return solcx.install.get_executable(version)
-        except SolcNotInstalled:
-            pass
-
-    # Last resort is to use the system installation
-    default_binary = "/usr/bin/solc"
-    if os.path.exists(default_binary):
+    elif os.path.exists(default_binary):
         return default_binary
+
+    else:
+        return None

mythril/mythril/mythril_disassembler.py

@@ -3,6 +3,7 @@ import re
 import solc
 import sys
 import os
+import platform
 
 from ethereum import utils
 from typing import List, Tuple, Optional
@@ -54,7 +55,13 @@ class MythrilDisassembler:
             return os.environ.get("SOLC") or "solc"
 
         # tried converting input to semver, seemed not necessary so just slicing for now
-        main_version = solc.main.get_solc_version_string()
+        main_version = solc.get_solc_version_string()
+
+        # In case instead of just the version number, --solv v0.x.x is used
+
+        if version.startswith("v"):
+            version = version[1:]
+
         main_version_number = re.match(r"\d+.\d+.\d+", main_version)
         if main_version is None:
             raise CriticalError(
@@ -65,35 +72,20 @@ class MythrilDisassembler:
             solc_binary = os.environ.get("SOLC") or "solc"
         else:
             solc_binary = util.solc_exists(version)
-            if solc_binary and solc_binary != util.solc_exists(
-                "default_ubuntu_version"
-            ):
-                log.info("Given version is already installed")
-            else:
-                if version.startswith("0.4"):
-                    try:
-                        solc.install_solc("v" + version)
-                    except solc.exceptions.SolcError:
+            if solc_binary is None:
+                if sys.version_info[1] >= 6:
                     raise CriticalError(
-                            "There was an error when trying to install the specified solc version"
+                        "The version of solc that is needed cannot be installed automatically"
                     )
-                elif sys.version_info[1] >= 6:
-                    # solcx supports python 3.6+
-                    try:
-                        solcx.install_solc("v" + version)
-                    except solcx.exceptions.SolcError:
+                elif sys.version_info[1] == 5:
                     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."
                     )
                 else:
                     raise CriticalError(
-                        "Py-Solc doesn't support 0.5.*. You can switch to python 3.6 which uses solcx."
+                        "There was an error when trying to install the specified solc version"
                     )
-
-                solc_binary = util.solc_exists(version)
-                if not solc_binary:
-                    raise solc.exceptions.SolcError()
-
+            else:
                 log.info("Setting the compiler to %s", solc_binary)
 
         return solc_binary

requirements.txt

@@ -18,14 +18,14 @@ persistent>=4.2.0
 plyvel
 py-flags
 py-evm==0.3.0a13
-py-solc-x==0.10.0
+py-solc-x==0.10.1
 py-solc
 pytest>=3.6.0
 pytest-cov
 pytest_mock
 requests>=2.22.0
 rlp>=1.0.1
-semantic_version==2.8.1
+semantic_version==2.8.5
 transaction>=2.2.1
 z3-solver>=4.8.5.0
 pysha3

setup.py

@@ -30,8 +30,8 @@ REQUIRED = [
     "z3-solver>=4.8.5.0",
     "requests>=2.22.0",
     "py-solc",
-    "py-solc-x==0.6.0",
-    "semantic_version==2.8.1",
+    "py-solc-x==0.10.1",
+    "semantic_version==2.8.5",
     "plyvel",
     "eth_abi==1.3.0",
     "eth-account>=0.1.0a2,<=0.3.0",