Eliminate throw() per issue #44.

contracts/AllocatedCrowdsale.sol

@@ -57,6 +57,6 @@ contract AllocatedCrowdsale is Crowdsale {
    * Use approve() given to this crowdsale to distribute the tokens.
    */
   function assignTokens(address receiver, uint tokenAmount) private {
-    if(!token.transferFrom(beneficiary, receiver, tokenAmount)) throw;
+    require(token.transferFrom(beneficiary, receiver, tokenAmount));
   }
 }

contracts/BonusFinalizeAgent.sol

@@ -35,17 +35,10 @@ contract BonusFinalizeAgent is FinalizeAgent {
   uint public allocatedBonus;
 
   function BonusFinalizeAgent(CrowdsaleToken _token, Crowdsale _crowdsale, uint _bonusBasePoints, address _teamMultisig) {
+    require(address(_crowdsale) != 0 && address(_teamMultisig) != 0);
     token = _token;
     crowdsale = _crowdsale;
-    if(address(crowdsale) == 0) {
-      throw;
-    }
-
     teamMultisig = _teamMultisig;
-    if(address(teamMultisig) == 0) {
-      throw;
-    }
-
     bonusBasePoints = _bonusBasePoints;
   }
 
@@ -56,9 +49,7 @@ contract BonusFinalizeAgent is FinalizeAgent {
 
   /** Called once by crowdsale finalize() if the sale was success. */
   function finalizeCrowdsale() {
-    if(msg.sender != address(crowdsale)) {
-      throw;
-    }
+    require(msg.sender == address(crowdsale));
 
     // How many % of tokens the founders and others get
     uint tokensSold = crowdsale.tokensSold();

contracts/Crowdsale.sol

@@ -127,34 +127,23 @@ contract Crowdsale is Haltable {
 
   function Crowdsale(address _token, PricingStrategy _pricingStrategy, address _multisigWallet, uint _start, uint _end, uint _minimumFundingGoal) {
 
+    require(_multisigWallet != 0);
+    require(_start != 0 && _end != 0);
+
+    // Don't mess the dates
+    require(_start < _end);
+
     owner = msg.sender;
 
     token = FractionalERC20(_token);
 
     setPricingStrategy(_pricingStrategy);
 
     multisigWallet = _multisigWallet;
-    if(multisigWallet == 0) {
-        throw;
-    }
-
-    if(_start == 0) {
-        throw;
-    }
-
     startsAt = _start;
 
-    if(_end == 0) {
-        throw;
-    }
-
     endsAt = _end;
 
-    // Don't mess the dates
-    if(startsAt >= endsAt) {
-        throw;
-    }
-
     // Minimum funding goal can be zero
     minimumFundingGoal = _minimumFundingGoal;
   }
@@ -163,7 +152,7 @@ contract Crowdsale is Haltable {
    * Don't expect to just send in money and get tokens.
    */
   function() payable {
-    throw;
+    require(false);
   }
 
   /**
@@ -181,26 +170,21 @@ contract Crowdsale is Haltable {
     // Determine if it's a good time to accept investment from this participant
     if(getState() == State.PreFunding) {
       // Are we whitelisted for early deposit
-      if(!earlyParticipantWhitelist[receiver]) {
-        throw;
-      }
+      require(earlyParticipantWhitelist[receiver]);
     } else if(getState() == State.Funding) {
       // Retail participants can only come in when the crowdsale is running
       // pass
     } else {
       // Unwanted state
-      throw;
+      assert(false);
     }
 
     uint weiAmount = msg.value;
 
     // Account presale sales separately, so that they do not count against pricing tranches
     uint tokenAmount = pricingStrategy.calculatePrice(weiAmount, weiRaised - presaleWeiRaised, tokensSold, msg.sender, token.decimals());
 
-    if(tokenAmount == 0) {
-      // Dust transaction
-      throw;
-    }
+    require(tokenAmount != 0); // Dust transaction
 
     if(investedAmountOf[receiver] == 0) {
        // A new investor
@@ -220,14 +204,12 @@ contract Crowdsale is Haltable {
     }
 
     // Check that we did not bust the cap
-    if(isBreakingCap(weiAmount, tokenAmount, weiRaised, tokensSold)) {
-      throw;
-    }
+    require(!isBreakingCap(weiAmount, tokenAmount, weiRaised, tokensSold));
 
     assignTokens(receiver, tokenAmount);
 
     // Pocket the money
-    if(!multisigWallet.send(weiAmount)) throw;
+    require(multisigWallet.send(weiAmount));
 
     // Tell us invest was success
     Invested(receiver, weiAmount, tokenAmount, customerId);
@@ -270,26 +252,26 @@ contract Crowdsale is Haltable {
    */
   function investWithSignedAddress(address addr, uint128 customerId, uint8 v, bytes32 r, bytes32 s) public payable {
      bytes32 hash = sha256(addr);
-     if (ecrecover(hash, v, r, s) != signerAddress) throw;
-     if(customerId == 0) throw;  // UUIDv4 sanity check
+     require(ecrecover(hash, v, r, s) == signerAddress);
+     require(customerId != 0);  // UUIDv4 sanity check
      investInternal(addr, customerId);
   }
 
   /**
    * Track who is the customer making the payment so we can send thank you email.
    */
   function investWithCustomerId(address addr, uint128 customerId) public payable {
-    if(requiredSignedAddress) throw; // Crowdsale allows only server-side signed participants
-    if(customerId == 0) throw;  // UUIDv4 sanity check
+    require(!requiredSignedAddress); // Crowdsale allows only server-side signed participants
+    require(customerId != 0);  // UUIDv4 sanity check
     investInternal(addr, customerId);
   }
 
   /**
    * Allow anonymous contributions to this crowdsale.
    */
   function invest(address addr) public payable {
-    if(requireCustomerId) throw; // Crowdsale needs to track participants for thank you email
-    if(requiredSignedAddress) throw; // Crowdsale allows only server-side signed participants
+    require(!requireCustomerId); // Crowdsale needs to track partipants for thank you email
+    require(!requiredSignedAddress); // Crowdsale allows only server-side signed participants
     investInternal(addr, 0);
   }
 
@@ -326,9 +308,7 @@ contract Crowdsale is Haltable {
   function finalize() public inState(State.Success) onlyOwner stopInEmergency {
 
     // Already finalized
-    if(finalized) {
-      throw;
-    }
+    require(!finalized);
 
     // Finalizing is optional. We only call it if we are given a finalizing agent.
     if(address(finalizeAgent) != 0) {
@@ -344,12 +324,10 @@ contract Crowdsale is Haltable {
    * Design choice: no state restrictions on setting this, so that we can fix fat finger mistakes.
    */
   function setFinalizeAgent(FinalizeAgent addr) onlyOwner {
-    finalizeAgent = addr;
 
     // Don't allow setting bad agent
-    if(!finalizeAgent.isFinalizeAgent()) {
-      throw;
-    }
+    require(addr.isFinalizeAgent());
+    finalizeAgent = addr;
   }
 
   /**
@@ -395,13 +373,8 @@ contract Crowdsale is Haltable {
    */
   function setEndsAt(uint time) onlyOwner {
 
-    if(now > time) {
-      throw; // Don't change past
-    }
-
-    if(startsAt > time) {
-      throw; // Prevent human mistakes
-    }
+    require(now <= time); // Don't change past
+    require(time > startsAt); // Don't allow to end before we start
 
     endsAt = time;
     EndsAtChanged(endsAt);
@@ -413,12 +386,10 @@ contract Crowdsale is Haltable {
    * Design choice: no state restrictions on the set, so that we can fix fat finger mistakes.
    */
   function setPricingStrategy(PricingStrategy _pricingStrategy) onlyOwner {
-    pricingStrategy = _pricingStrategy;
 
     // Don't allow setting bad agent
-    if(!pricingStrategy.isPricingStrategy()) {
-      throw;
-    }
+    require(_pricingStrategy.isPricingStrategy());
+    pricingStrategy = _pricingStrategy;
   }
 
   /**
@@ -431,9 +402,7 @@ contract Crowdsale is Haltable {
   function setMultisig(address addr) public onlyOwner {
 
     // Change
-    if(investorCount > MAX_INVESTMENTS_BEFORE_MULTISIG_CHANGE) {
-      throw;
-    }
+    require(investorCount <= MAX_INVESTMENTS_BEFORE_MULTISIG_CHANGE);
 
     multisigWallet = addr;
   }
@@ -444,7 +413,7 @@ contract Crowdsale is Haltable {
    * The team can transfer the funds back on the smart contract in the case the minimum goal was not reached..
    */
   function loadRefund() public payable inState(State.Failure) {
-    if(msg.value == 0) throw;
+    require(msg.value != 0);
     loadedRefund = loadedRefund.plus(msg.value);
   }
 
@@ -456,11 +425,11 @@ contract Crowdsale is Haltable {
    */
   function refund() public inState(State.Refunding) {
     uint256 weiValue = investedAmountOf[msg.sender];
-    if (weiValue == 0) throw;
+    require(weiValue != 0);
     investedAmountOf[msg.sender] = 0;
     weiRefunded = weiRefunded.plus(weiValue);
     Refund(msg.sender, weiValue);
-    if (!msg.sender.send(weiValue)) throw;
+    require(msg.sender.send(weiValue));
   }
 
   /**
@@ -517,7 +486,7 @@ contract Crowdsale is Haltable {
 
   /** Modified allowing execution only if the crowdsale is currently running.  */
   modifier inState(State state) {
-    if(getState() != state) throw;
+    require(getState() == state);
     _;
   }
 

contracts/DefaultFinalizeAgent.sol

@@ -31,9 +31,7 @@ contract DefaultFinalizeAgent is FinalizeAgent {
 
   /** Called once by crowdsale finalize() if the sale was success. */
   function finalizeCrowdsale() public {
-    if(msg.sender != address(crowdsale)) {
-      throw;
-    }
+    require(msg.sender == address(crowdsale));
     token.releaseTokenTransfer();
   }
 

contracts/EthTranchePricing.sol

@@ -48,9 +48,7 @@ contract EthTranchePricing is PricingStrategy, Ownable {
   /// @param _tranches uint[] tranches Pairs of (start amount, price)
   function EthTranchePricing(uint[] _tranches) {
     // Need to have tuples, length check
-    if(_tranches.length % 2 == 1 || _tranches.length >= MAX_TRANCHES*2) {
-      throw;
-    }
+    require((_tranches.length % 2 == 0) && (_tranches.length < MAX_TRANCHES*2));
 
     trancheCount = _tranches.length / 2;
 
@@ -61,22 +59,16 @@ contract EthTranchePricing is PricingStrategy, Ownable {
       tranches[i].price = _tranches[i*2+1];
 
       // No invalid steps
-      if((highestAmount != 0) && (tranches[i].amount <= highestAmount)) {
-        throw;
-      }
+      require((highestAmount == 0) || (tranches[i].amount > highestAmount));
 
       highestAmount = tranches[i].amount;
     }
 
     // We need to start from zero, otherwise we blow up our deployment
-    if(tranches[0].amount != 0) {
-      throw;
-    }
+    require(tranches[0].amount == 0);
 
     // Last tranche price must be zero, terminating the crowdale
-    if(tranches[trancheCount-1].price != 0) {
-      throw;
-    }
+    require(tranches[trancheCount-1].price == 0);
   }
 
   /// @dev This is invoked once for every pre-ICO address, set pricePerToken
@@ -162,7 +154,7 @@ contract EthTranchePricing is PricingStrategy, Ownable {
   }
 
   function() payable {
-    throw; // No money on this contract
+    require(false); // No money on this contract
   }
 
 }

contracts/ExtraFinalizeAgent.sol

@@ -38,17 +38,12 @@ contract ExtraFinalizeAgent is FinalizeAgent {
   uint public accountedTokenSales;
 
   function ExtraFinalizeAgent(CrowdsaleToken _token, Crowdsale _crowdsale, uint _bonusBasePoints, address _teamMultisig, uint _accountedTokenSales) {
+    require(address(_crowdsale) != 0 && address(_teamMultisig) != 0);
+
     token = _token;
     crowdsale = _crowdsale;
 
-    if(address(crowdsale) == 0) {
-      throw;
-    }
-
     teamMultisig = _teamMultisig;
-    if(address(teamMultisig) == 0) {
-      throw;
-    }
 
     accountedTokenSales = _accountedTokenSales;
   }
@@ -60,9 +55,7 @@ contract ExtraFinalizeAgent is FinalizeAgent {
 
   /** Called once by crowdsale finalize() if the sale was success. */
   function finalizeCrowdsale() {
-    if(msg.sender != address(crowdsale)) {
-      throw;
-    }
+    require(msg.sender == address(crowdsale));
 
     // How many % of tokens the founders and others get
     uint tokensSold = crowdsale.tokensSold().minus(accountedTokenSales);

contracts/Haltable.sol

@@ -21,17 +21,17 @@ contract Haltable is Ownable {
   bool public halted;
 
   modifier stopInEmergency {
-    if (halted) throw;
+    require(!halted);
     _;
   }
 
   modifier stopNonOwnersInEmergency {
-    if (halted && msg.sender != owner) throw;
+    require(!halted || msg.sender == owner);
     _;
   }
 
   modifier onlyInEmergency {
-    if (!halted) throw;
+    require(halted);
     _;
   }
 

contracts/Issuer.sol

@@ -43,7 +43,7 @@ contract Issuer is Ownable {
   }
 
   function issue(address benefactor, uint amount) onlyOwner {
-    if(issued[benefactor]) throw;
+    require(!issued[benefactor]);
     token.transferFrom(allower, benefactor, amount);
     issued[benefactor] = true;
     issuedCount += amount;