Merge pull request #1772 from eth-brownie/fix-from-explorer

Fall back to ABI when `Contract.from_explorer` compilation fails

Author: iamdefinitelyahuman

brownie/network/contract.py

@@ -998,11 +998,12 @@ def from_explorer(
                 raise exc
             abi = json.loads(data_abi["result"].strip())
             name = "UnknownContractName"
-            warnings.warn(
-                f"{address}: Was able to fetch the ABI but not the source code. "
-                "Some functionality will not be available.",
-                BrownieCompilerWarning,
-            )
+            if not silent:
+                warnings.warn(
+                    f"{address}: Was able to fetch the ABI but not the source code. "
+                    "Some functionality will not be available.",
+                    BrownieCompilerWarning,
+                )
 
         if as_proxy_for is None:
             # always check for an EIP1967 proxy - https://eips.ethereum.org/EIPS/eip-1967
@@ -1084,40 +1085,49 @@ def from_explorer(
             evm_version = None
 
         source_str = "\n".join(data["result"][0]["SourceCode"].splitlines())
-        if source_str.startswith("{{"):
-            # source was verified using compiler standard JSON
-            input_json = json.loads(source_str[1:-1])
-            sources = {k: v["content"] for k, v in input_json["sources"].items()}
-            evm_version = input_json["settings"].get("evmVersion", evm_version)
-            remappings = input_json["settings"].get("remappings", [])
-
-            compiler.set_solc_version(str(version))
-            input_json.update(
-                compiler.generate_input_json(
-                    sources, optimizer=optimizer, evm_version=evm_version, remappings=remappings
+        try:
+            if source_str.startswith("{{"):
+                # source was verified using compiler standard JSON
+                input_json = json.loads(source_str[1:-1])
+                sources = {k: v["content"] for k, v in input_json["sources"].items()}
+                evm_version = input_json["settings"].get("evmVersion", evm_version)
+                remappings = input_json["settings"].get("remappings", [])
+
+                compiler.set_solc_version(str(version))
+                input_json.update(
+                    compiler.generate_input_json(
+                        sources, optimizer=optimizer, evm_version=evm_version, remappings=remappings
+                    )
                 )
-            )
-            output_json = compiler.compile_from_input_json(input_json)
-            build_json = compiler.generate_build_json(input_json, output_json)
-        else:
-            if source_str.startswith("{"):
-                # source was submitted as multiple files
-                sources = {k: v["content"] for k, v in json.loads(source_str).items()}
+                output_json = compiler.compile_from_input_json(input_json)
+                build_json = compiler.generate_build_json(input_json, output_json)
             else:
-                # source was submitted as a single file
-                if compiler_str.startswith("vyper"):
-                    path_str = f"{name}.vy"
+                if source_str.startswith("{"):
+                    # source was submitted as multiple files
+                    sources = {k: v["content"] for k, v in json.loads(source_str).items()}
                 else:
-                    path_str = f"{name}-flattened.sol"
-                sources = {path_str: source_str}
-
-            build_json = compiler.compile_and_format(
-                sources,
-                solc_version=str(version),
-                vyper_version=str(version),
-                optimizer=optimizer,
-                evm_version=evm_version,
-            )
+                    # source was submitted as a single file
+                    if compiler_str.startswith("vyper"):
+                        path_str = f"{name}.vy"
+                    else:
+                        path_str = f"{name}-flattened.sol"
+                    sources = {path_str: source_str}
+
+                build_json = compiler.compile_and_format(
+                    sources,
+                    solc_version=str(version),
+                    vyper_version=str(version),
+                    optimizer=optimizer,
+                    evm_version=evm_version,
+                )
+        except Exception as e:
+            if not silent:
+                warnings.warn(
+                    f"{address}: Compilation failed due to {type(e).__name__}. Falling back to ABI,"
+                    " some functionality will not be available.",
+                    BrownieCompilerWarning,
+                )
+            return cls.from_abi(name, address, abi, owner)
 
         build_json = build_json[name]
         if as_proxy_for is not None:
@@ -1126,10 +1136,11 @@ def from_explorer(
         if not _verify_deployed_code(
             address, build_json["deployedBytecode"], build_json["language"]
         ):
-            warnings.warn(
-                f"{address}: Locally compiled and on-chain bytecode do not match!",
-                BrownieCompilerWarning,
-            )
+            if not silent:
+                warnings.warn(
+                    f"{address}: Locally compiled and on-chain bytecode do not match!",
+                    BrownieCompilerWarning,
+                )
             del build_json["pcMap"]
 
         self = cls.__new__(cls)