Only generate assert in checked mode.

lib/compiler/implementation/ssa/builder.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class Interceptors {
   Compiler compiler;
   Interceptors(Compiler this.compiler);
 
   SourceString mapOperatorToMethodName(Operator op) {
     String name = op.source.stringValue;
@@ skipping 2354 matching lines @@
       add(typeInfoSetter);
       Selector setSelector = Selector.INVOCATION_2;
       var inputs = <HInstruction>[typeInfoSetter, instance, typeInfo];
       add(new HInvokeStatic(setSelector, inputs));
     }
   }
 
   visitStaticSend(Send node) {
     Selector selector = elements.getSelector(node);
     Element element = elements[node];
+    if (element == compiler.assertMethod && !compiler.enableUserAssertions) {

[kasperl, 2012/06/08 05:34:05]

===?

[ngeoffray, 2012/06/08 09:40:58]

Done.

+      stack.add(graph.addConstantNull());

[karlklose, 2012/06/08 07:42:42]

I guess we add null here because we do not check that assert(...) is an
statement. However, as an expression, a call to something with the name assert
can never resolve to assertMethod. I think have to resolve assert(...)
differently when it is not in a statement expression context.

[ahe, 2012/06/08 07:59:14]

I don't think Nicolas needs to worry about this now, we are a few people that
plan to look at negative tests, and it would be fine if Nicolas defers this
issue to us.

[ngeoffray, 2012/06/08 09:40:58]

OK. Note that I think we will keep the the addConstantNull to not complicate the
builder already. The resolver has done all the work, we know the builder will
just remove this constantNull later on.

+      return;
+    }
     compiler.ensure(element.kind !== ElementKind.GENERATIVE_CONSTRUCTOR);
     HInstruction target = new HStatic(element);
     add(target);
     var inputs = <HInstruction>[];
     inputs.add(target);
     if (element.kind == ElementKind.FUNCTION) {
       bool succeeded = addStaticSendArgumentsToList(selector, node.arguments,
                                                     element, inputs);
       if (!succeeded) {
         // TODO(ngeoffray): Match the VM behavior and throw an
@@ skipping 1045 matching lines @@
   void visitNodeList(NodeList node) {
      node.visitChildren(this);
   }
 
   HInstruction concat(HInstruction left, HInstruction right) {
     HInstruction instruction = new HStringConcat(left, right, node);
     builder.add(instruction);
     return instruction;
   }
 }