assembly and ast

tests/Proxy/Proxy.sol

@@ -0,0 +1,52 @@
+pragma solidity ^0.4.24;
+
+/**
+ * @title Proxy
+ * @dev Gives the possibility to delegate any call to a foreign implementation.
+ */
+contract Proxy {
+
+    /**
+    * @dev Tells the address of the implementation where every call will be delegated.
+    * @return address of the implementation to which it will be delegated
+    */
+    function _implementation() internal view returns (address);
+
+    /**
+    * @dev Fallback function.
+    * Implemented entirely in `_fallback`.
+    */
+    function _fallback() internal {
+        _delegate(_implementation());
+    }
+
+    /**
+    * @dev Fallback function allowing to perform a delegatecall to the given implementation.
+    * This function will return whatever the implementation call returns
+    */
+    function _delegate(address implementation) internal {
+        /*solium-disable-next-line security/no-inline-assembly*/
+        assembly {
+            // Copy msg.data. We take full control of memory in this inline assembly
+            // block because it will not return to Solidity code. We overwrite the
+            // Solidity scratch pad at memory position 0.
+            calldatacopy(0, 0, calldatasize)
+
+            // Call the implementation.
+            // out and outsize are 0 because we don't know the size yet.
+            let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)
+
+            // Copy the returned data.
+            returndatacopy(0, 0, returndatasize)
+
+            switch result
+            // delegatecall returns 0 on error.
+            case 0 { revert(0, returndatasize) }
+            default { return(0, returndatasize) }
+        }
+    }
+
+    function () public payable {
+        _fallback();
+    }
+}

tests/Proxy/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,110 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`Proxy.sol 1`] = `
+pragma solidity ^0.4.24;
+
+/**
+ * @title Proxy
+ * @dev Gives the possibility to delegate any call to a foreign implementation.
+ */
+contract Proxy {
+
+    /**
+    * @dev Tells the address of the implementation where every call will be delegated.
+    * @return address of the implementation to which it will be delegated
+    */
+    function _implementation() internal view returns (address);
+
+    /**
+    * @dev Fallback function.
+    * Implemented entirely in \`_fallback\`.
+    */
+    function _fallback() internal {
+        _delegate(_implementation());
+    }
+
+    /**
+    * @dev Fallback function allowing to perform a delegatecall to the given implementation.
+    * This function will return whatever the implementation call returns
+    */
+    function _delegate(address implementation) internal {
+        /*solium-disable-next-line security/no-inline-assembly*/
+        assembly {
+            // Copy msg.data. We take full control of memory in this inline assembly
+            // block because it will not return to Solidity code. We overwrite the
+            // Solidity scratch pad at memory position 0.
+            calldatacopy(0, 0, calldatasize)
+
+            // Call the implementation.
+            // out and outsize are 0 because we don't know the size yet.
+            let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)
+
+            // Copy the returned data.
+            returndatacopy(0, 0, returndatasize)
+
+            switch result
+            // delegatecall returns 0 on error.
+            case 0 { revert(0, returndatasize) }
+            default { return(0, returndatasize) }
+        }
+    }
+
+    function () public payable {
+        _fallback();
+    }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+pragma solidity ^0.4.24;
+
+/**
+ * @title Proxy
+ * @dev Gives the possibility to delegate any call to a foreign implementation.
+ */
+contract Proxy {
+  /**
+    * @dev Tells the address of the implementation where every call will be delegated.
+    * @return address of the implementation to which it will be delegated
+    */
+  function _implementation() internal view returns (address);
+
+  /**
+    * @dev Fallback function.
+    * Implemented entirely in \`_fallback\`.
+    */
+  function _fallback() internal {
+    _delegate(_implementation());
+  }
+
+  /**
+    * @dev Fallback function allowing to perform a delegatecall to the given implementation.
+    * This function will return whatever the implementation call returns
+    */
+  function _delegate(address implementation) internal {
+    /*solium-disable-next-line security/no-inline-assembly*/
+    assembly {
+      // Copy msg.data. We take full control of memory in this inline assembly
+      // block because it will not return to Solidity code. We overwrite the
+      // Solidity scratch pad at memory position 0.
+      calldatacopy(0, 0, calldatasize)
+      // Call the implementation.
+      // out and outsize are 0 because we don't know the size yet.
+      let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)
+      // Copy the returned data.
+      returndatacopy(0, 0, returndatasize)
+      switch result
+        // delegatecall returns 0 on error.
+        case 0 {
+          revert(0, returndatasize)
+        }
+        default {
+          return(0, returndatasize)
+        }
+    }
+  }
+
+  function() public payable {
+    _fallback();
+  }
+}
+
+`;

tests/Proxy/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);