Only generate assert in checked mode.

lib/compiler/implementation/compiler.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 WorkItem {
   final Element element;
   TreeElements resolutionTree;
   bool allowSpeculativeOptimization = true;
   List<HTypeGuard> guards = const <HTypeGuard>[];
 
@@ skipping 61 matching lines @@
 }
 
 class Compiler implements DiagnosticListener {
   final Map<String, LibraryElement> libraries;
   int nextFreeClassId = 0;
   World world;
   String assembledCode;
   Namer namer;
   Types types;
   final bool enableTypeAssertions;
+  final bool enableUserAssertions;
 
   final Tracer tracer;
 
   CompilerTask measuredTask;
   Element _currentElement;
   LibraryElement coreLibrary;
   LibraryElement coreImplLibrary;
   LibraryElement isolateLibrary;
   LibraryElement jsHelperLibrary;
   LibraryElement interceptorsLibrary;
   LibraryElement mainApp;
 
   ClassElement objectClass;
   ClassElement closureClass;
   ClassElement dynamicClass;
   ClassElement boolClass;
   ClassElement numClass;
   ClassElement intClass;
   ClassElement doubleClass;
   ClassElement stringClass;
   ClassElement functionClass;
   ClassElement nullClass;
   ClassElement listClass;
+  Element assertMethod;
 
   Element get currentElement() => _currentElement;
   withCurrentElement(Element element, f()) {
     Element old = currentElement;
     _currentElement = element;
     try {
       return f();
     } catch (CompilerCancelledException ex) {
       throw;
     } catch (var ex) {
@@ skipping 21 matching lines @@
   static final SourceString NO_SUCH_METHOD_EXCEPTION =
       const SourceString('NoSuchMethodException');
   static final SourceString START_ROOT_ISOLATE =
       const SourceString('startRootIsolate');
   bool enabledNoSuchMethod = false;
 
   Stopwatch codegenProgress;
 
   Compiler([this.tracer = const Tracer(),
             this.enableTypeAssertions = false,
+            this.enableUserAssertions = false,
             bool emitJavascript = true,
             validateUnparse = false])
       : libraries = new Map<String, LibraryElement>(),
         world = new World(),
         codegenProgress = new Stopwatch.start() {
     namer = new Namer(this);
     constantHandler = new ConstantHandler(this);
     scanner = new ScannerTask(this);
     dietParser = new DietParserTask(this);
     parser = new ParserTask(this);
@@ skipping 160 matching lines @@
     // TODO(ahe): Clean this up as described above.
     scanner.importLibrary(coreImplLibrary, coreLibrary, null);
     scanner.importLibrary(jsHelperLibrary, coreLibrary, null);
     scanner.importLibrary(interceptorsLibrary, coreLibrary, null);
     addForeignFunctions(jsHelperLibrary);
     addForeignFunctions(interceptorsLibrary);
 
     libraries['dart:core'] = coreLibrary;
     libraries['dart:coreimpl'] = coreImplLibrary;
 
+    assertMethod = coreLibrary.find(const SourceString('assert'));
+
     initializeSpecialClasses();
   }
 
   /** Define the JS helper functions in the given library. */
   void addForeignFunctions(LibraryElement library) {
     library.define(new ForeignElement(
         const SourceString('JS'), library), this);
     library.define(new ForeignElement(
         const SourceString('UNINTERCEPTED'), library), this);
     library.define(new ForeignElement(
@@ skipping 254 matching lines @@
     // invariant that endOffset > beginOffset, but for EOF the
     // charoffset of the next token may be [beginOffset]. This can
     // also happen for synthetized tokens that are produced during
     // error handling.
     final endOffset =
       Math.max((end.next !== null) ? end.next.charOffset : 0, beginOffset + 1);
     assert(endOffset > beginOffset);
     return f(beginOffset, endOffset);
   }
 }