fixes 854

remix-analyzer/src/solidity-analyzer/modules/etherTransferInLoop.js

@@ -0,0 +1,31 @@
+var name = 'Ether transfer in a loop: '
+var desc = 'Avoid transferring Ether to multiple addresses in a loop'
+var categories = require('./categories')
+var common = require('./staticAnalysisCommon')
+
+function etherTransferInLoop () {
+  this.relevantNodes = []
+}
+
+etherTransferInLoop.prototype.visit = function (node) {
+  if (common.isLoop(node) && common.isTransfer(node)) {
+    this.relevantNodes.push(node)
+  }
+}
+
+etherTransferInLoop.prototype.report = function (compilationResults) {
+  return this.relevantNodes.map((node) => {
+    return {
+      warning: 'Ether payout should not be done in a loop: Due to the block gas limit, transactions can only consume a certain amount of gas. The number of iterations in a loop can grow beyond the block gas limit which can cause the complete contract to be stalled at a certain point. If required then make sure that number of iterations are low and you trust each address involved.',
+      location: node.src,
+      more: 'https://solidity.readthedocs.io/en/latest/security-considerations.html#gas-limit-and-loops'
+    }
+  })
+}
+
+module.exports = {
+  name: name,
+  description: desc,
+  category: categories.GAS,
+  Module: etherTransferInLoop
+}

remix-analyzer/src/solidity-analyzer/modules/staticAnalysisCommon.js

@@ -947,6 +947,17 @@ function isBytesLengthCheck (node) {
   return isMemberAccess(node, exactMatch(util.escapeRegExp(basicTypes.UINT)), undefined, util.escapeRegExp('bytes *'), 'length')
 }
 
+/**
+ * True if it is a loop
+ * @node {ASTNode} some AstNode
+ * @return {bool}
+ */
+function isLoop (node) {
+  return nodeType(node, exactMatch(nodeTypes.FORSTATEMENT)) ||
+          nodeType(node, exactMatch(nodeTypes.WHILESTATEMENT)) ||
+          nodeType(node, exactMatch(nodeTypes.DOWHILESTATEMENT))
+}
+
 /**
  * True if it is a 'for' loop
  * @node {ASTNode} some AstNode
@@ -1117,6 +1128,7 @@ module.exports = {
   isIntDivision: isIntDivision,
   isStringToBytesConversion: isStringToBytesConversion,
   isBytesLengthCheck: isBytesLengthCheck,
+  isLoop: isLoop,
   isForLoop: isForLoop,
 
   // #################### Trivial Node Identification