Implement EIP150 [WIP]

lib/hooked.js

@@ -17,6 +17,7 @@ module.exports.fromWeb3Provider = fromWeb3Provider
   ```js
   var vm = createHookedVm({
     enableHomestead: true,
+    enableHomesteadReprice: true
   }, {
     fetchAccountBalance: function(addressHex, cb){ ... },
     fetchAccountNonce: function(addressHex, cb){ ... },

lib/index.js

@@ -25,6 +25,7 @@ VM.deps = {
  * @param {Blockchain} [opts.blockchain] A blockchain object for storing/retrieving blocks
  * @param {Boolean} [opts.activatePrecompiles] Create entries in the state tree for the precompiled contracts
  * @param {Boolean} [opts.enableHomestead] Force enable Homestead irrelevant to block number
+ * @param {Boolean} [opts.enableHomesteadReprice] Force enable Homestead Reprice (EIP150) irrevelant to block number
  */
 function VM (opts = {}) {
   this.stateManager = new StateManager({

lib/opFns.js

@@ -549,6 +549,8 @@ module.exports = {
 
     checkCallMemCost(runState, options, localOpts)
 
+    gasLimit = calcCallLimit(runState, gasLimit)
+
     stateManager.exists(toAddress, function (err, exists) {
       if (err) {
         done(err)
@@ -679,6 +681,12 @@ module.exports = {
         cb(err)
         return
       }
+
+      if (runState.enableHomsteadReprice && !toAccount.exists) {
+        // can't wrap because we are in a callback
+        runState.gasLeft.isub(new BN(fees.callNewAccountGas.v))
+      }
+
       var newBalance = new Buffer(new BN(contract.balance).add(new BN(toAccount.balance)).toArray())
       async.series([
         stateManager.putAccountBalance.bind(stateManager, suicideToAddress, newBalance),
@@ -877,3 +885,14 @@ function makeCall (runState, callOptions, localOpts, cb) {
     }
   }
 }
+
+function calcCallLimit (runState, gas) {
+  if (!runState.enableHomesteadReprice) {
+    return gas
+  }
+
+  // div should round down
+  const max = runState.gasLimit.sub(runState.gasLimit.div(64))
+
+  return BN.min(gas, max)
+}

lib/runCall.js

@@ -43,6 +43,7 @@ module.exports = function (opts, cb) {
   var depth = opts.depth
   var suicides = opts.suicides
   var enableHomestead = this.opts.enableHomestead === undefined ? block.isHomestead() : this.opts.enableHomestead
+  var enableHomesteadReprice = this.opts.enableHomesteadReprice === undefined ? block.isHomesteadReprice() : this.opts.enableHomesteadReprice
 
   txValue = new BN(txValue)
 

lib/runCode.js

@@ -73,6 +73,7 @@ module.exports = function (opts, cb) {
     code: opts.code,
     populateCache: opts.populateCache === undefined ? true : opts.populateCache,
     enableHomestead: this.opts.enableHomestead === undefined ? block.isHomestead() : this.opts.enableHomestead // this == vm
+    enableHomesteadReprice: this.opts.enableHomesteadReprice === undefined ? block.isHomesteadReprice() : this.opts.enableHomesteadReprice // this == vm
   }
 
   // temporary - to be factored out

lib/runTx.js

@@ -27,10 +27,6 @@ module.exports = function (opts, cb) {
     block = new Block()
   }
 
-  if (this.opts.enableHomestead) {
-    tx._homestead = true
-  }
-
   if (new BN(block.header.gasLimit).cmp(new BN(tx.gasLimit)) === -1) {
     cb(new Error('tx has a higher gas limit than the block'))
     return