From ecbd1874bf2055d69808367b7cccbc7485df96dd Mon Sep 17 00:00:00 2001
From: "scheglov@google.com" <scheglov@google.com>
Date: Wed, 1 Feb 2012 17:47:04 +0000
Subject: [PATCH] Recompile unit with potential conflict/dependency on some
 top-level symbol.

1. Change dependency tracking from API version on unit to just unit last modified time.

2. Track sets of top-level and all declared symbols in units, recompile in case of possible conflict.

3. Track units with TypeErrorCode.CANNOT_BE_RESOLVED, recompile if any unit changes top-level symbols.

4. Better tests with source code directly in test method.

R=zundel@google.com
BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com//9148026

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@3799 260f80e4-7a28-3924-810f-c04153c831b5
---
 .../google/dart/compiler/DartCompiler.java    | 229 ++++---
 .../dart/compiler/DartCompilerErrorCode.java  |   5 +
 .../compiler/DartCompilerMainContext.java     |  32 +
 .../compiler/DefaultDartArtifactProvider.java |   2 +-
 .../google/dart/compiler/DeltaAnalyzer.java   |   1 -
 .../com/google/dart/compiler/ErrorCode.java   |   6 +
 .../com/google/dart/compiler/LibraryDeps.java | 341 +++++++---
 .../dart/compiler/LibraryDepsVisitor.java     |  69 +-
 .../google/dart/compiler/ast/DartClass.java   |  21 -
 .../google/dart/compiler/ast/DartField.java   |  15 -
 .../google/dart/compiler/ast/DartNode.java    |  18 -
 .../compiler/ast/DartToSourceVisitor.java     |  17 -
 .../google/dart/compiler/ast/DartUnit.java    |  86 ++-
 .../google/dart/compiler/ast/LibraryNode.java |   5 +-
 .../google/dart/compiler/ast/LibraryUnit.java | 208 ------
 .../doc/DartDocumentationGenerator.java       |  17 +-
 .../backend/js/ClosureJsErrorCode.java        |   5 +
 .../dart/compiler/backend/js/JsErrorCode.java |   5 +
 .../dart/compiler/parser/DartParser.java      |  37 +-
 .../dart/compiler/parser/ParserErrorCode.java |   5 +
 .../compiler/resolver/ResolverErrorCode.java  |  23 +-
 .../dart/compiler/resolver/TypeErrorCode.java |  27 +-
 .../compiler/MockBundleLibrarySource.java     |   1 +
 .../TypeHeuristicImplementationTest.java      |  10 +-
 .../compiler/common/ErrorExpectation.java     |  77 ++-
 .../dart/compiler/end2end/End2EndTests.java   |   2 +
 .../inc/IncrementalCompilation2Test.java      | 561 ++++++++++++++++
 .../inc/IncrementalCompilationTest.java       | 624 ++++++++----------
 .../IncrementalCompilationWithPrefixTest.java |  30 +-
 .../end2end/inc/MemoryLibrarySource.java      | 108 +++
 .../dart/compiler/end2end/inc/my.app.dart     |   2 +-
 .../compiler/parser/AbstractParserTest.java   |   6 +-
 .../compiler/parser/NegativeParserTest.java   |  91 +++
 .../resolver/NegativeResolverTest.java        |  10 +
 .../type/TypeAnalyzerCompilerTest.java        |  34 +
 35 files changed, 1735 insertions(+), 995 deletions(-)
 create mode 100644 compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilation2Test.java
 create mode 100644 compiler/javatests/com/google/dart/compiler/end2end/inc/MemoryLibrarySource.java

diff --git a/compiler/java/com/google/dart/compiler/DartCompiler.java b/compiler/java/com/google/dart/compiler/DartCompiler.java
index 6aff5e63ec0..8287ea5c92f 100644
--- a/compiler/java/com/google/dart/compiler/DartCompiler.java
+++ b/compiler/java/com/google/dart/compiler/DartCompiler.java
@@ -5,6 +5,8 @@
 package com.google.dart.compiler;
 
 import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+import com.google.common.collect.Sets.SetView;
 import com.google.common.io.CharStreams;
 import com.google.common.io.Closeables;
 import com.google.common.io.Files;
@@ -69,7 +71,6 @@ import java.util.Set;
  */
 public class DartCompiler {
 
-  public static final String EXTENSION_API = "api";
   public static final String EXTENSION_DEPS = "deps";
   public static final String EXTENSION_LOG = "log";
 
@@ -230,9 +231,8 @@ public class DartCompiler {
     }
 
     /**
-     * This method reads all libraries, updating their apis as necessary. They
-     * will be populated from some combination of fully-parsed compilation units
-     * and api files.
+     * This method reads all libraries. They will be populated from some combination of fully-parsed
+     * and diet-parser compilation units.
      */
     private void parseOutOfDateFiles() throws IOException {
       TraceEvent logEvent =
@@ -241,17 +241,21 @@ public class DartCompiler {
       long parseStart = compilerMetrics != null ? CompilerMetrics.getCPUTime() : 0;
 
       try {
+        final Set<String> topLevelSymbolsDiff = Sets.newHashSet();
         for (LibraryUnit lib : libraries.values()) {
           LibrarySource libSrc = lib.getSource();
-          boolean libIsDartUri = SystemLibraryManager.isDartUri(libSrc.getUri());
-          LibraryUnit apiLib = new LibraryUnit(libSrc);
           LibraryNode selfSourcePath = lib.getSelfSourcePath();
-          boolean shouldLoadApi = incremental || (libIsDartUri && usePrecompiledDartLibs);
-          boolean apiOutOfDate = !(shouldLoadApi && apiLib.loadApi(context, context));
+          boolean libIsDartUri = SystemLibraryManager.isDartUri(libSrc.getUri());
 
-          // Parse each compilation unit and update the API to reflect its contents.
+          // Load the existing DEPS, or create an empty one.
+          LibraryDeps deps = lib.getDeps(context);
+          Set<String> newUnitPaths = Sets.newHashSet();
+
+          // Parse each compilation unit.
           for (LibraryNode libNode : lib.getSourcePaths()) {
-            final DartSource dartSrc = libSrc.getSourceFor(libNode.getText());
+            String relPath = libNode.getText();
+            newUnitPaths.add(relPath);
+            final DartSource dartSrc = libSrc.getSourceFor(relPath);
             if (dartSrc == null || !dartSrc.exists()) {
               // Dart Editor needs to have all missing files reported as compilation errors.
               // In addition, continue allows lib.populateTopLevelNodes() to be called so that the
@@ -260,35 +264,89 @@ public class DartCompiler {
               continue;
             }
 
-            DartUnit apiUnit = apiLib.getUnit(dartSrc.getName());
-            if (apiUnit == null || isSourceOutOfDate(dartSrc, libSrc)) {
-              DartUnit unit = parse(dartSrc, lib.getPrefixes());
+
+            if (!incremental
+                || (libIsDartUri && !usePrecompiledDartLibs)
+                || isSourceOutOfDate(dartSrc, libSrc)) {
+              DartUnit unit = parse(dartSrc, lib.getPrefixes(),  false);
               if (unit != null) {
                 if (libNode == selfSourcePath) {
                   lib.setSelfDartUnit(unit);
                 }
+                // Replace unit within the library.
                 lib.putUnit(unit);
-                apiOutOfDate = true;
+                context.setFilesHaveChanged();
+                // Include into top-level symbols diff from current units, already existed or new.
+                {
+                  LibraryDeps.Source source = deps.getSource(relPath);
+                  Set<String> newTopSymbols = unit.getTopDeclarationNames();
+                  if (source != null) {
+                    Set<String> oldTopSymbols = source.getTopSymbols();
+                    SetView<String> diff0 = Sets.symmetricDifference(oldTopSymbols, newTopSymbols);
+                    topLevelSymbolsDiff.addAll(diff0);
+                  } else {
+                    topLevelSymbolsDiff.addAll(newTopSymbols);
+                  }
+                }
               }
             } else {
-              if (libNode == selfSourcePath) {
-                lib.setSelfDartUnit(apiUnit);
+              DartUnit dietUnit = parse(dartSrc, lib.getPrefixes(), true);
+              if (dietUnit != null) {
+                if (libNode == selfSourcePath) {
+                  lib.setSelfDartUnit(dietUnit);
+                }
+                lib.putUnit(dietUnit);
               }
-              lib.putUnit(apiUnit);
             }
           }
 
-          // Persist the api file.
-          if (apiOutOfDate) {
-            context.setFilesHaveChanged();
-            if (!checkOnly) {
-              lib.saveApi(context);
+          // Include into top-level symbols diff from units which disappeared since last compiling.
+          {
+            Set<String> oldUnitPaths = deps.getUnitPaths();
+            Set<String> disappearedUnitPaths = Sets.difference(oldUnitPaths, newUnitPaths);
+            for (String relPath : disappearedUnitPaths) {
+              LibraryDeps.Source source = deps.getSource(relPath);
+              if (source != null) {
+                Set<String> oldTopSymbols = source.getTopSymbols();
+                topLevelSymbolsDiff.addAll(oldTopSymbols);
+              }
             }
           }
+        }
 
-          // Populate the library's class map. This is used later for
-          // dependency checking.
-          lib.populateTopLevelNodes();
+        // Parse units, which potentially depend on the difference in top-level symbols.
+        if (!topLevelSymbolsDiff.isEmpty()) {
+          context.setFilesHaveChanged();
+          for (LibraryUnit lib : libraries.values()) {
+            LibrarySource libSrc = lib.getSource();
+            LibraryNode selfSourcePath = lib.getSelfSourcePath();
+            LibraryDeps deps = lib.getDeps(context);
+            for (LibraryNode libNode : lib.getSourcePaths()) {
+              String relPath = libNode.getText();
+              // Prepare source dependency.
+              LibraryDeps.Source source = deps.getSource(relPath);
+              if (source == null) {
+                continue;
+              }
+              // Check re-compilation conditions.
+              if (source.shouldRecompileOnAnyTopLevelChange()
+                  || !Sets.intersection(source.getAllSymbols(), topLevelSymbolsDiff).isEmpty()
+                  || !Sets.intersection(source.getHoles(), topLevelSymbolsDiff).isEmpty()) {
+                DartSource dartSrc = libSrc.getSourceFor(relPath);
+                if (dartSrc == null || !dartSrc.exists()) {
+                  continue;
+                }
+                DartUnit unit = parse(dartSrc, lib.getPrefixes(), false);
+                if (unit != null) {
+                  if (libNode == selfSourcePath) {
+                    lib.setSelfDartUnit(unit);
+                  } else {
+                    lib.putUnit(unit);
+                  }
+                }
+              }
+            }
+          }
         }
       } finally {
         if (compilerMetrics != null) {
@@ -379,8 +437,7 @@ public class DartCompiler {
     }
 
     /**
-     * Determines whether the given source is out-of-date with respect to its artifacts or
-     * its library's associated api.
+     * Determines whether the given source is out-of-date with respect to its artifacts.
      */
     private boolean isSourceOutOfDate(DartSource dartSrc, LibrarySource libSrc) {
       TraceEvent logEvent =
@@ -405,7 +462,7 @@ public class DartCompiler {
             Tracer.end(backendEvent);
           }
         }
-        return (context.isOutOfDate(dartSrc, libSrc, EXTENSION_API));
+        return false;
       } finally {
         Tracer.end(logEvent);
       }
@@ -438,8 +495,7 @@ public class DartCompiler {
     }
 
     /**
-     * Parses compilation units that are out-of-date with respect to their dependencies. The
-     * parsed units will replace api units already in the library.
+     * Parses compilation units that are out-of-date with respect to their dependencies.
      */
     private void addOutOfDateDeps() throws IOException {
       TraceEvent logEvent = Tracer.canTrace() ? Tracer.start(DartEventType.ADD_OUTOFDATE) : null;
@@ -455,17 +511,22 @@ public class DartCompiler {
           // Load the existing DEPS, or create an empty one.
           LibraryDeps deps = lib.getDeps(context);
 
-          // Parse units that are out-of-date with respect to their
-          // dependencies.
-          for (String sourceName : deps.getSourceNames()) {
-            LibraryDeps.Source depSource = deps.getSource(sourceName);
-            if (isSourceOutOfDate(lib, depSource)) {
+          // Prepare all top-level symbols.
+          Set<String> oldTopLevelSymbols = Sets.newHashSet();
+          for (LibraryDeps.Source source : deps.getSources()) {
+            oldTopLevelSymbols.addAll(source.getTopSymbols());
+          }
+
+          // Parse units that are out-of-date with respect to their dependencies.
+          for (DartUnit unit : lib.getUnits()) {
+            String relPath = unit.getSource().getRelativePath();
+            LibraryDeps.Source source = deps.getSource(relPath);
+            if (isUnitOutOfDate(lib, source)) {
               filesHaveChanged = true;
-              DartSource dartSrc = lib.getSource().getSourceFor(sourceName);
-              if ((dartSrc != null) && (dartSrc.exists())) {
-                DartUnit unit = parse(dartSrc, lib.getPrefixes());
+              DartSource dartSrc = lib.getSource().getSourceFor(relPath);
+              if (dartSrc != null && dartSrc.exists()) {
+                unit = parse(dartSrc, lib.getPrefixes(), false);
                 if (unit != null) {
-                  // Replace the newly-parsed unit within the library.
                   lib.putUnit(unit);
                 }
               }
@@ -482,52 +543,30 @@ public class DartCompiler {
     }
 
     /**
-     * Determines whether the given source (as referenced by {@link LibraryDeps.Source}) is
-     * out-of-date with respect to any of its dependencies.
+     * Determines whether the given dependencies are out-of-date.
      */
-    private boolean isSourceOutOfDate(LibraryUnit lib, LibraryDeps.Source depSource) {
-      for (String nodeName : depSource.getNodeNames()) {
-        TraceEvent logEvent =
-            Tracer.canTrace() ? Tracer.start(DartEventType.IS_CLASS_OUT_OF_DATE, "class",
-                nodeName) : null;
-        try {
-          if (depSource.isHole(nodeName)) {
-            // The dependency's a "hole", meaning that any new identifier in the
-            // library scope that shadows it should force a recompile.
-            if (lib.getTopLevelNode(nodeName) != null) {
-              // The library defines a top-level node with the same name as the hole, so
-              // we need to recompile.
-              return true;
-            }
-          } else {
-            // Normal dependency.
-            Dependency dep = depSource.getDependency(nodeName);
-
-            // Find the cached API and get its hash.
-            LibraryUnit depLib = libraries.get(dep.getLibUri());
-            if (depLib == null) {
-              // The library no longer exists, so presume that we need to
-              // recompile.
-              return true;
-            }
-
-            // If there's a hash mismatch, deps are out of date
-            DartNode depNode = depLib.getTopLevelNode(nodeName);
-            if (depNode == null) {
-              // Node was removed. That's about as mismatched as you can get.
-              return true;
-            }
-            String hash = Integer.toString(depNode.computeHash());
-            if (!hash.equals(dep.getHash())) {
-              return true;
-            }
-          }
-        } finally {
-          Tracer.end(logEvent);
+    private boolean isUnitOutOfDate(LibraryUnit lib, LibraryDeps.Source source) {
+      // If we don't have dependency information, then we can not be sure that nothing changed.
+      if (source == null) {
+        return true;
+      }
+      // Check all dependencies.
+      for (Dependency dep : source.getDeps()) {
+        LibraryUnit depLib = libraries.get(dep.getLibUri());
+        if (depLib == null) {
+          return true;
+        }
+        // Prepare unit.
+        DartUnit depUnit = depLib.getUnit(dep.getUnitName());
+        if (depUnit == null) {
+          return true;
+        }
+        // May be unit modified.
+        if (depUnit.getSource().getLastModified() != dep.getLastModified()) {
+          return true;
         }
       }
-
-      // No holes or hash mismatches; in date.
+      // No changed dependencies.
       return false;
     }
 
@@ -684,7 +723,7 @@ public class DartCompiler {
 
         // Dump the compiler parse tree if dump format is set in arguments
         BaseASTWriter astWriter = ASTWriterFactory.create(config);
-        
+
         // Coverage instrumenter
         CoverageInstrumenter coverageInstrumenter = CoverageInstrumenter.createInstance(config);
         coverageInstrumenter.process(libraries);
@@ -698,7 +737,7 @@ public class DartCompiler {
 
             astWriter.process(unit);
 
-            // Don't compile api-only units.
+            // Don't compile diet units.
             if (unit.isDiet()) {
               continue;
             }
@@ -743,7 +782,7 @@ public class DartCompiler {
             }
 
             // Update deps.
-            lib.getDeps(context).update(unit, context);
+            lib.getDeps(context).update(context, unit);
 
             // We compiled something, so remember that this means we need to
             // persist the deps and package the app.
@@ -808,7 +847,7 @@ public class DartCompiler {
       }
     }
 
-    DartUnit parse(DartSource dartSrc, Set<String> libraryPrefixes) throws IOException {
+    DartUnit parse(DartSource dartSrc, Set<String> libraryPrefixes, boolean diet) throws IOException {
       TraceEvent parseEvent =
           Tracer.canTrace() ? Tracer.start(DartEventType.PARSE, "src", dartSrc.getName()) : null;
       CompilerMetrics compilerMetrics = context.getCompilerMetrics();
@@ -833,7 +872,7 @@ public class DartCompiler {
         } else {
           DartScannerParserContext parserContext =
               new DartScannerParserContext(dartSrc, srcCode, context, context.getCompilerMetrics());
-          parser = new DartParser(parserContext, libraryPrefixes);
+          parser = new DartParser(parserContext, libraryPrefixes, diet);
         }
         DartUnit unit = parser.parseUnit(dartSrc);
         if (compilerMetrics != null) {
@@ -891,13 +930,13 @@ public class DartCompiler {
     }
 
     @Override
-    DartUnit parse(DartSource dartSrc, Set<String> prefixes) throws IOException {
+    DartUnit parse(DartSource dartSrc, Set<String> prefixes, boolean diet) throws IOException {
       if (parsedUnits == null) {
-        return super.parse(dartSrc, prefixes);
+        return super.parse(dartSrc, prefixes, diet);
       }
       URI srcUri = dartSrc.getUri();
       DartUnit parsedUnit = parsedUnits.get(srcUri);
-      return parsedUnit == null ? super.parse(dartSrc, prefixes) : parsedUnit;
+      return parsedUnit == null ? super.parse(dartSrc, prefixes, diet) : parsedUnit;
     }
   }
 
@@ -1034,8 +1073,9 @@ public class DartCompiler {
   }
 
   /**
-   * Compiles the source file which could be a single *.dart source file or a *.app file.  If it
-   * is the former an *.app file is conceptually synthesized.
+   * Treats the <code>sourceFile</code> as the top level library and generates compiled output by
+   * linking the dart source in this file with all libraries referenced with <code>#import</code>
+   * statements.
    */
   public static String compileApp(File sourceFile, CompilerConfiguration config) throws IOException {
     TraceEvent logEvent =
@@ -1144,7 +1184,6 @@ public class DartCompiler {
       embeddedLibraries.add(new NamedPlaceHolderLibrarySource("dart:coreimpl"));
     }
 
-
     new Compiler(lib, embeddedLibraries, config, context).compile();
     int errorCount = context.getErrorCount();
     if (config.typeErrorsAreFatal()) {
@@ -1209,11 +1248,11 @@ public class DartCompiler {
         new TypeAnalyzer()
       };
       for (DartUnit unit : libraryUnit.getUnits()) {
-        // Don't analyze api-only units.
+        // Don't analyze diet units.
         if (unit.isDiet()) {
           continue;
         }
-  
+
         for (DartCompilationPhase phase : phases) {
           unit = phase.exec(unit, context, compiler.getTypeProvider());
           // Ignore errors. TypeAnalyzer should be able to cope with
diff --git a/compiler/java/com/google/dart/compiler/DartCompilerErrorCode.java b/compiler/java/com/google/dart/compiler/DartCompilerErrorCode.java
index 105cf456f43..87078805f1b 100644
--- a/compiler/java/com/google/dart/compiler/DartCompilerErrorCode.java
+++ b/compiler/java/com/google/dart/compiler/DartCompilerErrorCode.java
@@ -50,4 +50,9 @@ public enum DartCompilerErrorCode implements ErrorCode {
   public SubSystem getSubSystem() {
     return SubSystem.COMPILER;
   }
+
+  @Override
+  public boolean needsRecompilation() {
+    return true;
+  }
 }
diff --git a/compiler/java/com/google/dart/compiler/DartCompilerMainContext.java b/compiler/java/com/google/dart/compiler/DartCompilerMainContext.java
index 5aff52ca5e2..beb23040698 100644
--- a/compiler/java/com/google/dart/compiler/DartCompilerMainContext.java
+++ b/compiler/java/com/google/dart/compiler/DartCompilerMainContext.java
@@ -4,6 +4,8 @@
 
 package com.google.dart.compiler;
 
+import com.google.common.collect.Lists;
+import com.google.common.collect.MapMaker;
 import com.google.dart.compiler.ast.DartUnit;
 import com.google.dart.compiler.ast.LibraryUnit;
 import com.google.dart.compiler.metrics.CompilerMetrics;
@@ -14,6 +16,9 @@ import java.io.IOException;
 import java.io.Reader;
 import java.io.Writer;
 import java.net.URI;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -29,6 +34,8 @@ final class DartCompilerMainContext implements DartCompilerListener, DartCompile
   private final LibrarySource lib;
   private final DartArtifactProvider provider;
   private final DartCompilerListener listener;
+  private final Map<Source, List<DartCompilationError>> errors =
+      new MapMaker().weakKeys().makeMap();
   private final AtomicInteger errorCount = new AtomicInteger(0);
   private final AtomicInteger warningCount = new AtomicInteger(0);
   private final AtomicInteger typeErrorCount = new AtomicInteger(0);
@@ -49,6 +56,19 @@ final class DartCompilerMainContext implements DartCompilerListener, DartCompile
 
   @Override
   public void onError(DartCompilationError event) {
+    // Remember error.
+    {
+      Source source = event.getSource();
+      if (source != null) {
+        List<DartCompilationError> sourceErrors = errors.get(source);
+        if (sourceErrors == null) {
+          sourceErrors = Lists.newArrayList();
+          errors.put(source, sourceErrors);
+        }
+        sourceErrors.add(event);
+      }
+    }
+    // Increment counters.
     if (event.getErrorCode().getSubSystem() == SubSystem.STATIC_TYPE) {
       incrementTypeErrorCount();
     } else if (shouldWarnOnNoSuchType() && event.getErrorCode() == ResolverErrorCode.NO_SUCH_TYPE) {
@@ -58,6 +78,7 @@ final class DartCompilerMainContext implements DartCompilerListener, DartCompile
     } else if (event.getErrorCode().getErrorSeverity() == ErrorSeverity.WARNING) {
       incrementWarningCount();
     }
+    // Notify listener.
     listener.onError(event);
   }
 
@@ -102,6 +123,17 @@ final class DartCompilerMainContext implements DartCompilerListener, DartCompile
     return provider.getArtifactWriter(source, part, extension);
   }
 
+  /**
+   * @return the {@link DartCompilationError}s found in the given {@link Source}.
+   */
+  public List<DartCompilationError> getSourceErrors(Source source) {
+    List<DartCompilationError> sourceErrors = errors.get(source);
+    if (sourceErrors != null) {
+      return sourceErrors;
+    }
+    return Collections.emptyList();
+  }
+
   public int getErrorCount() {
     return errorCount.get();
   }
diff --git a/compiler/java/com/google/dart/compiler/DefaultDartArtifactProvider.java b/compiler/java/com/google/dart/compiler/DefaultDartArtifactProvider.java
index 42efa0aa68c..b7058a76226 100644
--- a/compiler/java/com/google/dart/compiler/DefaultDartArtifactProvider.java
+++ b/compiler/java/com/google/dart/compiler/DefaultDartArtifactProvider.java
@@ -81,7 +81,7 @@ public class DefaultDartArtifactProvider extends DartArtifactProvider {
       }
     }
     File artifactFile = getArtifactFile(base, "", extension);
-    return artifactFile.lastModified() < source.getLastModified();
+    return !artifactFile.exists() || artifactFile.lastModified() < source.getLastModified();
   }
 
   // TODO(jbrosenberg): remove 'source' argument from this method, it's not used
diff --git a/compiler/java/com/google/dart/compiler/DeltaAnalyzer.java b/compiler/java/com/google/dart/compiler/DeltaAnalyzer.java
index 7e827c5cf92..78a04b02ad8 100644
--- a/compiler/java/com/google/dart/compiler/DeltaAnalyzer.java
+++ b/compiler/java/com/google/dart/compiler/DeltaAnalyzer.java
@@ -78,7 +78,6 @@ class DeltaAnalyzer {
     // Create a library unit which holds the new unit.
     LibraryUnit libraryUnit = new LibraryUnit(makeLibrarySource("delta"));
     libraryUnit.putUnit(unit);
-    libraryUnit.populateTopLevelNodes();
 
     // Create top-level elements for the new unit.
     new TopLevelElementBuilder().exec(libraryUnit, context);
diff --git a/compiler/java/com/google/dart/compiler/ErrorCode.java b/compiler/java/com/google/dart/compiler/ErrorCode.java
index 4305b82f41a..5662c3cb0c2 100644
--- a/compiler/java/com/google/dart/compiler/ErrorCode.java
+++ b/compiler/java/com/google/dart/compiler/ErrorCode.java
@@ -22,4 +22,10 @@ public interface ErrorCode {
    * @return the {@link SubSystem} which issued this error.
    */
   SubSystem getSubSystem();
+
+  /**
+   * @return <code>true</code> if this {@link ErrorCode} should cause recompilation of the source
+   *         during next incremental compilation.
+   */
+  boolean needsRecompilation();
 }
diff --git a/compiler/java/com/google/dart/compiler/LibraryDeps.java b/compiler/java/com/google/dart/compiler/LibraryDeps.java
index a1ec4a0100a..38fdf10b41a 100644
--- a/compiler/java/com/google/dart/compiler/LibraryDeps.java
+++ b/compiler/java/com/google/dart/compiler/LibraryDeps.java
@@ -1,188 +1,311 @@
 // Copyright (c) 2011, 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.
-
 package com.google.dart.compiler;
 
+import com.google.common.base.Objects;
+import com.google.common.base.Splitter;
+import com.google.common.base.Strings;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
 import com.google.dart.compiler.ast.DartUnit;
 
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.Reader;
-import java.io.StringWriter;
 import java.io.Writer;
 import java.net.URI;
-import java.net.URISyntaxException;
-import java.util.ArrayList;
-import java.util.Collections;
+import java.util.List;
 import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
+import java.util.Map.Entry;
+import java.util.Set;
 
 /**
  * Represents a library's dependencies artifact.
  */
 public class LibraryDeps {
+  private static final String VERSION = "v00001";
 
   /**
-   * Each dependency record contains the library in which it was found, along with a hash of its
-   * structure. Any change in the hash of the target dependency will force a recompile of the
-   * associated compilation unit.
+   * Each dependency record contains the library in which it was found, name of the unit in this
+   * library and last-modified timestamp. Any change in the timestamp of the target dependency will
+   * force a recompile of the associated compilation unit.
    */
   public static class Dependency {
     private final URI libUri;
-    private final String hash;
+    private final String unitName;
+    private final long lastModified;
 
-    public Dependency(URI libUri, String hash) {
+    public Dependency(URI libUri, String unitName, long lastModified) {
       this.libUri = libUri;
-      this.hash = hash;
+      this.unitName = unitName;
+      this.lastModified = lastModified;
     }
 
-    public String getHash() {
-      return hash;
+    @Override
+    public boolean equals(Object obj) {
+      if (obj instanceof Dependency) {
+        Dependency dep = (Dependency) obj;
+        return Objects.equal(libUri, dep.libUri) && Objects.equal(unitName, dep.unitName);
+      }
+      return false;
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hashCode(libUri, unitName);
     }
 
     public URI getLibUri() {
       return libUri;
     }
+
+    public String getUnitName() {
+      return unitName;
+    }
+
+    public long getLastModified() {
+      return lastModified;
+    }
   }
 
-  /**
-   * Each source is a map from class names to its associated {@link Dependency}.
-   * 
-   * A special dependency entry, called a 'hole', represents a name that, if
-   * newly-defined in the library scope, will force a recompile of the unit.
-   * This is represented by the static constant {@link Source#HOLE}.
-   */
   public static class Source {
-    private final Map<String, Dependency> deps = new ConcurrentHashMap<String, Dependency>();
-    private final static Dependency HOLE = new Dependency(null, null);
+    private final Set<Dependency> deps = Sets.newHashSet();
+    private final Set<String> topSymbols = Sets.newHashSet();
+    private final Set<String> allSymbols = Sets.newHashSet();
+    private final Set<String> holes = Sets.newHashSet();
+    private boolean shouldRecompileOnAnyTopLevelChange = false;
 
     /**
-     * Gets the node names of all dependencies for this source.
+     * @return the {@link Set} of {@link Dependency}s.
      */
-    public Iterable<String> getNodeNames() {
-      return deps.keySet();
+    public Set<Dependency> getDeps() {
+      return deps;
     }
 
-    public void putDependency(String nodeName, Dependency dep) {
-      deps.put(nodeName, dep);
+    /**
+     * @return the names of top-level elements, such as methods and classes.
+     */
+    public Set<String> getTopSymbols() {
+      return topSymbols;
     }
 
-    public Dependency getDependency(String nodeName) {
-      return deps.get(nodeName);
+    /**
+     * @return the names of all elements in unit, such as names of local variables, fields, etc.
+     */
+    public Set<String> getAllSymbols() {
+      return allSymbols;
     }
 
-    public void putHole(String nodeName) {
-      deps.put(nodeName, HOLE);
+    /**
+     * @return the names of functions, which are invoked without qualifier. So, declaration or
+     *         removing function with such name on top-level should cause recompiling.
+     */
+    public Set<String> getHoles() {
+      return holes;
     }
 
-    public boolean isHole(String nodeName) {
-      return deps.containsKey(nodeName) && (deps.get(nodeName) == HOLE);
+    /**
+     * @return <code>true</code> if this unit should be recompiled on any change in the set of
+     *         top-level symbols. Typically unit has compilation errors, which potentially may be
+     *         fixed, so we should recompile this unit.
+     */
+    public boolean shouldRecompileOnAnyTopLevelChange() {
+      return shouldRecompileOnAnyTopLevelChange;
+    }
+
+    /**
+     * Adds new {@link Dependency}.
+     */
+    public void addDep(Dependency dep) {
+      deps.add(dep);
+    }
+
+    /**
+     * Adds symbol to the {@link Set} of top symbols.
+     */
+    public void addTopSymbol(String symbol) {
+      if (!Strings.isNullOrEmpty(symbol)) {
+        topSymbols.add(symbol);
+      }
+    }
+
+    /**
+     * Adds symbol to the {@link Set} of all symbols.
+     */
+    public void addAllSymbol(String symbol) {
+      allSymbols.add(symbol);
+    }
+    
+    /**
+     * Adds new hole for {@link #getHoles()}.
+     */
+    public void addHole(String hole) {
+      holes.add(hole);
     }
   }
 
-  public static LibraryDeps fromReader(Reader reader) throws IOException {
+  public static LibraryDeps fromReader(Reader reader) {
+    try {
+      return fromReaderEx(reader);
+    } catch (Throwable e) {
+      return null;
+    }
+  }
+
+  private static LibraryDeps fromReaderEx(Reader reader) throws Exception {
     LibraryDeps deps = new LibraryDeps();
     BufferedReader buf = new BufferedReader(reader);
-    String srcName;
-    while (null != (srcName = buf.readLine())) {
-      Source src = new Source();
-
-      String line;
-      while (null != (line = buf.readLine())) {
-        // Blank line: next source.
+    // Check version.
+    {
+      String line = buf.readLine();
+      if (!Objects.equal(line, VERSION)) {
+        return deps;
+      }
+    }
+    // Read units dependencies.
+    String relPath;
+    while (null != (relPath = buf.readLine())) {
+      Source source = new Source();
+      // Read flags.
+      source.shouldRecompileOnAnyTopLevelChange = Boolean.parseBoolean(buf.readLine());
+      // Read top symbols.
+      {
+        String line = buf.readLine();
+        Iterable<String> topSymbols = Splitter.on(' ').omitEmptyStrings().split(line);
+        Iterables.addAll(source.topSymbols, topSymbols);
+      }
+      // Read all symbols.
+      {
+        String line = buf.readLine();
+        Iterable<String> allSymbols = Splitter.on(' ').omitEmptyStrings().split(line);
+        Iterables.addAll(source.allSymbols, allSymbols);
+      }
+      // Read holes.
+      {
+        String line = buf.readLine();
+        Iterable<String> holes = Splitter.on(' ').omitEmptyStrings().split(line);
+        Iterables.addAll(source.holes, holes);
+      }
+      // Read dependencies.
+      while (true) {
+        String line = buf.readLine();
+        // Blank line: next unit.
         if (line.length() == 0) {
           break;
         }
-
+        // Parse line.
         String[] parts = line.split(" ");
-        switch (parts.length) {
-          case 3:
-            // Full dependency.
-            try {
-              src.deps.put(parts[0], new Dependency(new URI(parts[1]), parts[2]));
-            } catch (URISyntaxException e) {
-              return null;
-            }
-            break;
-          case 1:
-            // Name only: hole.
-            src.deps.put(parts[0], Source.HOLE);
-            break;
-          default:
-            return null;
-        }
+        source.deps.add(new Dependency(new URI(parts[0]), parts[1], Long.parseLong(parts[2])));
       }
-
-      deps.sources.put(srcName, src);
+      // Remember dependencies for current unit.
+      deps.sources.put(relPath, source);
     }
-
     return deps;
   }
 
-  private final Map<String, Source> sources = new ConcurrentHashMap<String, Source>();
+  private final Map<String, Source> sources = Maps.newHashMap();
 
   public LibraryDeps() {
   }
 
-  public Source getSource(String sourceName) {
-    return sources.get(sourceName);
-  }
-
-  public Iterable<String> getSourceNames() {
+  /**
+   * @return the relative paths of all units with remembered dependencies.
+   */
+  public Set<String> getUnitPaths() {
     return sources.keySet();
   }
 
-  public void setSource(String sourceName, Source source) {
-    sources.put(sourceName, source);
+  /**
+   * @return all {@link Source} descriptions for all units in this library.
+   */
+  public Iterable<Source> getSources() {
+    return sources.values();
   }
 
-  @Override
-  public String toString() {
-    try {
-      StringWriter writer = new StringWriter();
-      write(writer);
-      return writer.toString();
-    } catch (IOException e) {
-      throw new AssertionError();
+  /**
+   * @return the {@link Source} description of the unit with given path.
+   */
+  public Source getSource(String relPath) {
+    return sources.get(relPath);
+  }
+
+  /**
+   * Remembers {@link Dependency}s of the unit with given path.
+   */
+  public void putSource(String relPath, Source source) {
+    sources.put(relPath, source);
+  }
+
+  /**
+   * Update the library dependencies to reflect this unit's classes.
+   */
+  public void update(DartCompilerMainContext context, DartUnit unit) {
+    Source source = new Source();
+    String relPath = unit.getSource().getRelativePath();
+    putSource(relPath, source);
+    // Remember dependencies.
+    LibraryDepsVisitor.exec(unit, source);
+    // Fill Source with symbols.
+    for (String name : unit.getDeclarationNames()) {
+      source.addAllSymbol(name);
+    }
+    for (String name : unit.getTopDeclarationNames()) {
+      source.addTopSymbol(name);
+    }
+    // Analyze errors and see if any of them should force recompilation.
+    List<DartCompilationError> sourceErrors = context.getSourceErrors(unit.getSource());
+    for (DartCompilationError error : sourceErrors) {
+      if (error.getErrorCode().needsRecompilation()) {
+        source.shouldRecompileOnAnyTopLevelChange = true;
+        break;
+      }
     }
   }
 
-  public void update(DartUnit unit, DartCompilerContext context) {
-    // Update the library deps to reflect this unit's classes.
-    LibraryDepsVisitor.exec(unit, this);
-  }
-
   public void write(Writer writer) throws IOException {
-    // For stability from run to run, this output needs to be sorted
-    ArrayList<String> sortedSourceNames = new ArrayList<String>(sources.size());
-    sortedSourceNames.addAll(sources.keySet());
-    Collections.sort(sortedSourceNames);
-    
-    for (String srcName : sortedSourceNames) {
-      writer.write(srcName);
+    // Write version.
+    writer.write(VERSION);
+    writer.write('\n');
+    // Write entries.
+    for (Entry<String, Source> entry : sources.entrySet()) {
+      String relPath = entry.getKey();
+      Source source = entry.getValue();
+      // Unit name.
+      writer.write(relPath);
       writer.write('\n');
-      Source src = sources.get(srcName);
-      
-      // sort the types per source name
-      ArrayList<String> sortedTypes = new ArrayList<String>(src.deps.size());
-      sortedTypes.addAll(src.deps.keySet());
-      Collections.sort(sortedTypes);
-      
-      for (String type : sortedTypes) {
-        writer.write(type);
-
-        Dependency dep = src.getDependency(type);
-        if (dep != Source.HOLE) {
-          writer.write(' ');
-          writer.write(dep.libUri.toString());
-          writer.write(' ');
-          writer.write(dep.hash);
-        }
-
+      // Flags.
+      writer.write(Boolean.toString(source.shouldRecompileOnAnyTopLevelChange));
+      writer.write('\n');
+      // Write top symbols.
+      for (String symbol : source.topSymbols) {
+        writer.write(symbol);
+        writer.write(' ');
+      }
+      writer.write('\n');
+      // Write all symbols.
+      for (String symbol : source.allSymbols) {
+        writer.write(symbol);
+        writer.write(' ');
+      }
+      writer.write('\n');
+      // Write holes.
+      for (String hole : source.holes) {
+        writer.write(hole);
+        writer.write(' ');
+      }
+      writer.write('\n');
+      // Write dependencies.
+      for (Dependency dep : source.deps) {
+        writer.write(dep.libUri.toString());
+        writer.write(' ');
+        writer.write(dep.unitName);
+        writer.write(' ');
+        writer.write(Long.toString(dep.lastModified));
         writer.write('\n');
       }
-
+      // Empty line after each unit.
       writer.write('\n');
     }
   }
diff --git a/compiler/java/com/google/dart/compiler/LibraryDepsVisitor.java b/compiler/java/com/google/dart/compiler/LibraryDepsVisitor.java
index 14de2a45d8b..e66601aff78 100644
--- a/compiler/java/com/google/dart/compiler/LibraryDepsVisitor.java
+++ b/compiler/java/com/google/dart/compiler/LibraryDepsVisitor.java
@@ -1,13 +1,10 @@
 // Copyright (c) 2011, 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.
-
 package com.google.dart.compiler;
 
 import com.google.dart.compiler.ast.DartClass;
-import com.google.dart.compiler.ast.DartField;
 import com.google.dart.compiler.ast.DartIdentifier;
-import com.google.dart.compiler.ast.DartMethodDefinition;
 import com.google.dart.compiler.ast.DartNode;
 import com.google.dart.compiler.ast.DartNodeTraverser;
 import com.google.dart.compiler.ast.DartParameterizedTypeNode;
@@ -27,36 +24,26 @@ import java.net.URI;
  * A visitor that fills in {@link LibraryDeps} for a compilation unit.
  */
 public class LibraryDepsVisitor extends DartNodeTraverser<Void> {
-
   /**
-   * Fill in library dependencies from a compilation unit.
-   *
-   * @param unit the unit whose dependencies are to be filled in
-   * @param deps the target library deps
+   * Fill in {@link LibraryDeps} from a {@link DartUnit}.
    */
-  static void exec(DartUnit unit, LibraryDeps deps) {
-    LibraryDepsVisitor v = new LibraryDepsVisitor();
+  static void exec(DartUnit unit, LibraryDeps.Source source) {
+    LibraryDepsVisitor v = new LibraryDepsVisitor(source);
     unit.accept(v);
-
-    String relPath = unit.getSource().getRelativePath();
-    deps.setSource(relPath, v.source);
   }
 
-  private final LibraryDeps.Source source = new LibraryDeps.Source();
+  private final LibraryDeps.Source source;
   private DartClass currentClass;
 
-  private LibraryDepsVisitor() {
+  private LibraryDepsVisitor(LibraryDeps.Source source) {
+    this.source = source;
   }
 
   @Override
   public Void visitIdentifier(DartIdentifier node) {
     Element target = node.getTargetSymbol();
     ElementKind kind = ElementKind.of(target);
-
-    // Deal with field and method references:
-    // - Add explicit dependencies on top-level fields and method.
-    // - Add "holes" for fields and methods found in a superclass (see LibraryDeps for further
-    //   explanation).
+    // Add dependency on the field or method.
     switch (kind) {
       case FIELD:
       case METHOD: {
@@ -68,13 +55,11 @@ public class LibraryDepsVisitor extends DartNodeTraverser<Void> {
         break;
       }
     }
-
     // Add dependency on the computed type of identifiers.
     switch (kind) {
       case NONE:
       case DYNAMIC:
         break;
-
       default: {
         Type type = target.getType();
         if (type != null) {
@@ -86,7 +71,6 @@ public class LibraryDepsVisitor extends DartNodeTraverser<Void> {
         break;
       }
     }
-
     return null;
   }
 
@@ -101,7 +85,7 @@ public class LibraryDepsVisitor extends DartNodeTraverser<Void> {
         return super.visitPropertyAccess(node);
       }
     }
-    // Skip rhs of property accesses, so that all identifiers we visit will be
+    // Skip rhs of property accesses, so that all identifiers we visit will be 
     // unqualified.
     return node.getQualifier().accept(this);
   }
@@ -136,46 +120,27 @@ public class LibraryDepsVisitor extends DartNodeTraverser<Void> {
    * Add a 'hole' for the given identifier, if its declaring class is a superclass of the current
    * class. A 'hole' dependency specifies a name that, if filled by something in the library scope,
    * would require this unit to be recompiled.
-   *
+   * 
    * This situation occurs because names in the library scope bind more strongly than unqualified
    * superclass members.
    */
   private void addHoleIfSuper(DartIdentifier node, Element holder) {
-    if (ElementKind.of(holder).equals(ElementKind.CLASS)
-        && holder != currentClass.getSymbol()) {
-      source.putHole(node.getTargetName());
+    if (ElementKind.of(holder).equals(ElementKind.CLASS) && holder != currentClass.getSymbol()) {
+      source.addHole(node.getTargetName());
     }
   }
 
   /**
-   * Adds a direct dependency on the given class.
+   * Adds a direct dependency on the unit providing given {@link Element}.
    */
   private void addElementDependency(Element elem) {
     DartNode node = elem.getNode();
     if (node != null) {
-      Source nodeSource = node.getSource();
-      URI libUri = ((DartSource) nodeSource).getLibrary().getUri();
-      LibraryDeps.Dependency dep = new LibraryDeps.Dependency(libUri,
-          Integer.toString(node.computeHash()));
-
-      String name;
-      switch (elem.getKind()) {
-        case CLASS:
-          name = ((DartClass) node).getClassName();
-          break;
-        case FIELD:
-          name = ((DartField) node).getName().getTargetName();
-          break;
-        case METHOD:
-          DartMethodDefinition method = (DartMethodDefinition) node;
-          DartIdentifier ident = (DartIdentifier) method.getName();
-          name = ident.getTargetName();
-          break;
-        default:
-          throw new AssertionError("Unexpected top-level node type");
-      }
-
-      source.putDependency(name, dep);
+      DartSource unitSource = (DartSource) node.getSource();
+      URI libUri = unitSource.getLibrary().getUri();
+      LibraryDeps.Dependency dep =
+          new LibraryDeps.Dependency(libUri, unitSource.getName(), unitSource.getLastModified());
+      source.addDep(dep);
     }
   }
 }
diff --git a/compiler/java/com/google/dart/compiler/ast/DartClass.java b/compiler/java/com/google/dart/compiler/ast/DartClass.java
index 1143e648d14..a8045cd5f28 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartClass.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartClass.java
@@ -27,8 +27,6 @@ public class DartClass extends DartDeclaration<DartIdentifier> implements HasSym
   private DartParameterizedTypeNode defaultClass;
   private final Modifiers modifiers;
 
-  private int hash = -1;
-
   // If the Dart class is implemented by a native JS class the nativeName
   // points to the JS class. Otherwise it is null.
   private final DartStringLiteral nativeName;
@@ -56,14 +54,6 @@ public class DartClass extends DartDeclaration<DartIdentifier> implements HasSym
         Modifiers.NONE);
   }
 
-  /**
-   * Set the diet-string hash code for the class
-   * @param hash the hash code to set
-   */
-  void setHash(int hash) {
-    this.hash = hash;
-  }
-
   public DartClass(DartIdentifier name, DartStringLiteral nativeName,
                    DartTypeNode superclass, List<DartTypeNode> interfaces,
                    List<DartNode> members,
@@ -215,15 +205,4 @@ public class DartClass extends DartDeclaration<DartIdentifier> implements HasSym
   public <R> R accept(DartPlainVisitor<R> visitor) {
     return visitor.visitClass(this);
   }
-
-  @Override
-  public int computeHash() {
-    // TODO(jgw): Remove this altogether in fixing b/5324113.
-
-    // Cache hashes for DartClass, because they're always needed.
-    if (this.hash == -1) {
-      this.hash = super.computeHash();
-    }
-    return this.hash;
-  }
 }
diff --git a/compiler/java/com/google/dart/compiler/ast/DartField.java b/compiler/java/com/google/dart/compiler/ast/DartField.java
index 4a2c587fab4..1718ca80b14 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartField.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartField.java
@@ -77,19 +77,4 @@ public class DartField extends DartClassMember<DartIdentifier> {
   public <R> R accept(DartPlainVisitor<R> visitor) {
     return visitor.visitField(this);
   }
-
-  @Override
-  public int computeHash() {
-    // TODO(jgw): Remove this altogether in fixing b/5324113.
-
-    // DartField doesn't include the type-node, so we directly return the hash of its type, which
-    // is all that matters for the purposes of dependency-tracking.
-    DartFieldDefinition def = (DartFieldDefinition) getParent();
-    DartTypeNode typeNode = def.getTypeNode();
-    if (typeNode == null) {
-      // Use 0 to represent an untyped field.
-      return 0;
-    }
-    return typeNode.computeHash();
-  }
 }
diff --git a/compiler/java/com/google/dart/compiler/ast/DartNode.java b/compiler/java/com/google/dart/compiler/ast/DartNode.java
index 67cd158ace3..8c30143c89b 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartNode.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartNode.java
@@ -143,24 +143,6 @@ public abstract class DartNode extends AbstractNode implements DartVisitable {
 
   public abstract <R> R accept(DartPlainVisitor<R> visitor);
 
-  public int computeHash() {
-    // TODO(jgw): Remove this altogether in fixing b/5324113.
-    //
-    // This computes a "hash" of the class' interface by simply serializing it to diet source and
-    // computing a hash of the string. This will work for now, but encodes too much information in
-    // the hash, and is slower than it should be. It should also cache the result and invalidate it
-    // if anything substantive changes.
-    //
-    // Examples of changes incorrectly captured by this hash, which would cause unnecessary
-    // recompiled include:
-    // - any change in method/field order would trigger an unnecessary recompile.
-    // - purely lexical changes such as {int x; int y;} => {int x, y;}
-    //
-    DefaultTextOutput out = new DefaultTextOutput(false);
-    new DartToSourceVisitor(out, true).accept(this);
-    return out.toString().trim().hashCode();
-  }
-
   @Override
   public DartNode clone() {
     // TODO (fabiomfv) - Implement proper cloning when strictly needed.
diff --git a/compiler/java/com/google/dart/compiler/ast/DartToSourceVisitor.java b/compiler/java/com/google/dart/compiler/ast/DartToSourceVisitor.java
index 2a4c25f52c1..059620cb500 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartToSourceVisitor.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartToSourceVisitor.java
@@ -25,8 +25,6 @@ public class DartToSourceVisitor extends DartVisitor {
   private List<SourceMapping> mappings = Lists.newArrayList();
   private final boolean isDiet;
 
-  private final boolean calculateHash;
-
   public DartToSourceVisitor(TextOutput out) {
     this(out, false);
   }
@@ -34,13 +32,6 @@ public class DartToSourceVisitor extends DartVisitor {
   public DartToSourceVisitor(TextOutput out, boolean isDiet) {
     this.out = out;
     this.isDiet = isDiet;
-    this.calculateHash = false;
-  }
-
-  public DartToSourceVisitor(TextOutput out, boolean isDiet, boolean calculateHash) {
-    this.out = out;
-    this.isDiet = isDiet;
-    this.calculateHash = calculateHash;
   }
 
   public void generateSourceMap(boolean generate) {
@@ -132,11 +123,6 @@ public class DartToSourceVisitor extends DartVisitor {
 
   @Override
   public boolean visit(DartClass x, DartContext ctx) {
-    int start = 0;
-    if (calculateHash == true) {
-      start = out.getPosition();
-    }
-
     if (x.isInterface()) {
       p("interface ");
     } else {
@@ -185,9 +171,6 @@ public class DartToSourceVisitor extends DartVisitor {
 
     outdent();
     p("}");
-    if (calculateHash == true) {
-      x.setHash(out.toString().substring(start, out.getPosition()).hashCode());
-    }
     nl();
     nl();
     return false;
diff --git a/compiler/java/com/google/dart/compiler/ast/DartUnit.java b/compiler/java/com/google/dart/compiler/ast/DartUnit.java
index 400a65c1f3f..40faf843fc5 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartUnit.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartUnit.java
@@ -5,12 +5,14 @@
 package com.google.dart.compiler.ast;
 
 import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
 import com.google.dart.compiler.DartSource;
 import com.google.dart.compiler.util.DefaultTextOutput;
 
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Represents a Dart compilation unit.
@@ -116,7 +118,7 @@ public class DartUnit extends DartNode {
   public final String toDietSource() {
     if (dietParse == null) {
       DefaultTextOutput out = new DefaultTextOutput(false);
-      new DartToSourceVisitor(out, true, true).accept(this);
+      new DartToSourceVisitor(out, true).accept(this);
       dietParse = out.toString();
     }
     return dietParse;
@@ -141,4 +143,86 @@ public class DartUnit extends DartNode {
     }
     return directives;
   }
+
+  /**
+   * @return the names of top-level declarations.
+   */
+  public Set<String> getTopDeclarationNames() {
+    Set<String> topLevelSymbols = Sets.newHashSet();
+    for (DartNode node : getTopLevelNodes()) {
+      if (node instanceof DartClass) {
+        DartIdentifier name = ((DartClass) node).getName();
+        topLevelSymbols.add(name.getTargetName());
+      }
+      if (node instanceof DartFunctionTypeAlias) {
+        DartIdentifier name = ((DartFunctionTypeAlias) node).getName();
+        topLevelSymbols.add(name.getTargetName());
+      }
+      if (node instanceof DartMethodDefinition) {
+        DartExpression name = ((DartMethodDefinition) node).getName();
+        topLevelSymbols.add(((DartIdentifier) name).getTargetName());
+      }
+      if (node instanceof DartFieldDefinition) {
+        DartFieldDefinition fieldDefinition = (DartFieldDefinition) node;
+        List<DartField> fields = fieldDefinition.getFields();
+        for (DartField variable : fields) {
+          topLevelSymbols.add(variable.getName().getTargetName());
+        }
+      }
+    }
+    return topLevelSymbols;
+  }
+
+  /**
+   * @return the {@link Set} of names of all declarations.
+   */
+  public Set<String> getDeclarationNames() {
+    final Set<String> symbols = Sets.newHashSet();
+    accept(new DartNodeTraverser<Void>() {
+      @Override
+      public Void visitFunctionTypeAlias(DartFunctionTypeAlias node) {
+        symbols.add(node.getName().getTargetName());
+        return super.visitFunctionTypeAlias(node);
+      }
+
+      @Override
+      public Void visitClass(DartClass node) {
+        symbols.add(node.getClassName());
+        return super.visitClass(node);
+      }
+
+      @Override
+      public Void visitTypeParameter(DartTypeParameter node) {
+        symbols.add(node.getName().getTargetName());
+        return super.visitTypeParameter(node);
+      }
+
+      @Override
+      public Void visitField(DartField node) {
+        symbols.add(node.getName().getTargetName());
+        return super.visitField(node);
+      }
+
+      @Override
+      public Void visitMethodDefinition(DartMethodDefinition node) {
+        if (node.getName() instanceof DartIdentifier) {
+          symbols.add(((DartIdentifier) node.getName()).getTargetName());
+        }
+        return super.visitMethodDefinition(node);
+      }
+
+      @Override
+      public Void visitParameter(DartParameter node) {
+        symbols.add(node.getParameterName());
+        return super.visitParameter(node);
+      }
+
+      @Override
+      public Void visitVariable(DartVariable node) {
+        symbols.add(node.getVariableName());
+        return super.visitVariable(node);
+      }
+    });
+    return symbols;
+  }
 }
\ No newline at end of file
diff --git a/compiler/java/com/google/dart/compiler/ast/LibraryNode.java b/compiler/java/com/google/dart/compiler/ast/LibraryNode.java
index b9f7c9a2133..41227cf5654 100644
--- a/compiler/java/com/google/dart/compiler/ast/LibraryNode.java
+++ b/compiler/java/com/google/dart/compiler/ast/LibraryNode.java
@@ -7,10 +7,7 @@ package com.google.dart.compiler.ast;
 import com.google.dart.compiler.common.AbstractNode;
 
 /**
- * An element in a library or application manifest
- *
- * TODO(jgw): This class works with both JSON and the new library syntax. It can be greatly
- * simplified once support for the JSON syntax is removed.
+ * An element in a library.
  */
 public class LibraryNode extends AbstractNode {
 
diff --git a/compiler/java/com/google/dart/compiler/ast/LibraryUnit.java b/compiler/java/com/google/dart/compiler/ast/LibraryUnit.java
index 0a18d76b65d..195f494141f 100644
--- a/compiler/java/com/google/dart/compiler/ast/LibraryUnit.java
+++ b/compiler/java/com/google/dart/compiler/ast/LibraryUnit.java
@@ -4,33 +4,22 @@
 
 package com.google.dart.compiler.ast;
 
-import com.google.common.io.CharStreams;
 import com.google.dart.compiler.DartCompiler;
 import com.google.dart.compiler.DartCompilerContext;
-import com.google.dart.compiler.DartCompilerListener;
 import com.google.dart.compiler.DartSource;
 import com.google.dart.compiler.LibraryDeps;
 import com.google.dart.compiler.LibrarySource;
-import com.google.dart.compiler.common.SourceInfo;
-import com.google.dart.compiler.metrics.DartEventType;
-import com.google.dart.compiler.metrics.Tracer;
-import com.google.dart.compiler.metrics.Tracer.TraceEvent;
-import com.google.dart.compiler.parser.DartParser;
-import com.google.dart.compiler.parser.DartScannerParserContext;
 import com.google.dart.compiler.resolver.Elements;
 import com.google.dart.compiler.resolver.LibraryElement;
 
 import java.io.IOException;
 import java.io.Reader;
 import java.io.Writer;
-import java.net.URI;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Set;
 import java.util.concurrent.ConcurrentSkipListMap;
 
@@ -38,11 +27,6 @@ import java.util.concurrent.ConcurrentSkipListMap;
  * Represents the parsed source from a {@link LibrarySource}.
  */
 public class LibraryUnit {
-
-  // This is intentionally unparseable as Dart.
-  private static final String UNIT_SEPARATOR_NAME = "--- unit-name: ";
-  private static final String UNIT_SEPARATOR_URI = "--- unit-uri: ";
-
   private final LibrarySource libSource;
   private final LibraryNode selfSourcePath;
   private final Collection<LibraryNode> importPaths = new ArrayList<LibraryNode>();
@@ -56,7 +40,6 @@ public class LibraryUnit {
 
   private final LibraryElement element;
 
-  private Map<String, DartNode> topLevelNodes;
   private LibraryDeps deps;
 
   private LibraryNode entryNode;
@@ -234,136 +217,6 @@ public class LibraryUnit {
     return nativePaths;
   }
 
-  /**
-   * Loads this library's associated api. If the api file exists, this will result in the library
-   * being populated with "diet" units (i.e., {@link DartUnit#isDiet()} will return
-   * <code>true</code>).
-   *
-   * @return <code>true</code> if the library was loaded from its api
-   */
-  public boolean loadApi(DartCompilerContext context, DartCompilerListener listener)
-      throws IOException {
-    TraceEvent parseEvent =
-        Tracer.canTrace() ? Tracer.start(DartEventType.PARSE_API, "src", getSource().getUri()
-            .toString()) : null;
-    try {
-      final Reader r = context.getArtifactReader(libSource, "", DartCompiler.EXTENSION_API);
-      if (r == null) {
-        return false;
-      }
-
-      // Read the API file.
-      String srcCode = CharStreams.toString(r);
-      r.close();
-
-      // Split it up by unit.
-      int idx = srcCode.indexOf(UNIT_SEPARATOR_NAME);
-      while (idx != -1) {
-        int endIdx;
-
-        // Prepare unit name.
-        idx += UNIT_SEPARATOR_NAME.length();
-        endIdx = srcCode.indexOf('\n', idx);
-        String unitName = srcCode.substring(idx, endIdx);
-        idx = endIdx;
-
-        // Prepare unit URI.
-        idx = srcCode.indexOf(UNIT_SEPARATOR_URI, endIdx);
-        idx += UNIT_SEPARATOR_URI.length();
-        endIdx = srcCode.indexOf('\n', idx);
-        String unitUri = srcCode.substring(idx, endIdx);
-        idx = endIdx;
-
-        // Find next unit, may be end string.
-        endIdx = srcCode.indexOf(UNIT_SEPARATOR_NAME, idx);
-
-        // Parse diet source unit.
-        String code = endIdx != -1 ? srcCode.substring(idx, endIdx) : srcCode.substring(idx);
-        parseApiUnit(unitName, unitUri, code, libSource, listener);
-
-        // Process next unit.
-        idx = endIdx;
-      }
-
-      return true;
-    } finally {
-      Tracer.end(parseEvent);
-    }
-  }
-
-  /**
-   * Saves this library's contents to its associated api file.
-   */
-  public void saveApi(DartCompilerContext context) throws IOException {
-    Writer w = context.getArtifactWriter(libSource, "", DartCompiler.EXTENSION_API);
-    for (Entry<String, DartUnit> entry : units.entrySet()) {
-      String unitName = entry.getKey();
-      DartUnit unit = entry.getValue();
-      w.write(UNIT_SEPARATOR_NAME + unitName + "\n");
-      w.write(UNIT_SEPARATOR_URI + unit.getSource().getUri() + "\n");
-      w.write(unit.toDietSource());
-    }
-    w.close();
-  }
-
-  /**
-   * Populates this unit's class map. This can be called only once per unit, and must be called
-   * before {@link #getTopLevelNode(String)} and {@link #getTopLevelNodes()}.
-   */
-  public void populateTopLevelNodes() {
-    assert topLevelNodes == null;
-    topLevelNodes = new HashMap<String, DartNode>();
-
-    DartNodeTraverser<Void> visitor = new DartNodeTraverser<Void>() {
-      @Override
-      public Void visitClass(DartClass node) {
-        topLevelNodes.put(node.getClassName(), node);
-        return null;
-      }
-
-      @Override
-      public Void visitMethodDefinition(DartMethodDefinition node) {
-        // Method names are always identifiers, except for factories, which cannot appear
-        // in this context.
-        DartExpression name = node.getName();
-        if(name instanceof DartIdentifier) {
-          topLevelNodes.put(((DartIdentifier) name).getTargetName(), node);
-        } else {
-          // Visit the unknown node to generate a string for our use.
-          topLevelNodes.put(node.getName().toSource(), node);
-        }
-        return null;
-      }
-
-      @Override
-      public Void visitField(DartField node) {
-        topLevelNodes.put(node.getName().getTargetName(), node);
-        return null;
-      }
-    };
-
-    for (DartUnit unit : units.values()) {
-      visitor.visitUnit(unit);
-    }
-  }
-
-  /**
-   * Get an unmodifiable collection of the classes in this library. You must call
-   * {@link #populateTopLevelNodes()} before this method will work.
-   */
-  public Collection<DartNode> getTopLevelNodes() {
-    return Collections.unmodifiableCollection(topLevelNodes.values());
-  }
-
-  /**
-   * Gets the {@link DartClass} associated with the given name. You must call
-   * {@link #populateTopLevelNodes()} before this method will work.
-   */
-  public DartNode getTopLevelNode(String name) {
-    assert topLevelNodes != null;
-    return topLevelNodes.get(name);
-  }
-
   /**
    * Return the declared entry method, if any
    *
@@ -411,65 +264,4 @@ public class LibraryUnit {
     deps.write(writer);
     writer.close();
   }
-
-  private void parseApiUnit(final String unitName,
-      final String unitUri,
-      String srcCode,
-      final LibrarySource libSrc,
-      DartCompilerListener listener) {
-    // Dummy source for the api unit.
-    DartSource src = new DartSource() {
-      @Override
-      public LibrarySource getLibrary() {
-        return libSrc;
-      }
-
-      @Override
-      public String getName() {
-        return unitName;
-      }
-
-      @Override
-      public Reader getSourceReader() {
-        return null;
-      }
-
-      @Override
-      public URI getUri() {
-        return URI.create(unitUri);
-      }
-
-      @Override
-      public boolean exists() {
-        return true;
-      }
-
-      @Override
-      public long getLastModified() {
-        return 0;
-      }
-
-      @Override
-      public String getRelativePath() {
-        return unitName;
-      }
-    };
-
-    DartScannerParserContext parserContext = new DartScannerParserContext(src, srcCode, listener);
-    DartParser parser = new DartParser(parserContext, true);
-    DartUnit unit = parser.parseUnit(src);
-
-    // When parsing from an API file, generate and store the hash for top level
-    // classes while we have the string available.  Reduces the time needed to
-    // recompute this later with a visitor.
-    for (DartNode node : unit.getTopLevelNodes()) {
-      if (node instanceof DartClass) {
-        SourceInfo nodeInfo = node.getSourceInfo();
-        String nodeString = srcCode.substring(nodeInfo.getSourceStart(),
-                                              nodeInfo.getSourceStart()+nodeInfo.getSourceLength());
-        ((DartClass)node).setHash(nodeString.hashCode());
-      }
-    }
-    putUnit(unit);
-  }
 }
diff --git a/compiler/java/com/google/dart/compiler/backend/doc/DartDocumentationGenerator.java b/compiler/java/com/google/dart/compiler/backend/doc/DartDocumentationGenerator.java
index c113f71c949..da3b34dc76a 100644
--- a/compiler/java/com/google/dart/compiler/backend/doc/DartDocumentationGenerator.java
+++ b/compiler/java/com/google/dart/compiler/backend/doc/DartDocumentationGenerator.java
@@ -4,6 +4,7 @@
 
 package com.google.dart.compiler.backend.doc;
 
+import com.google.common.collect.Lists;
 import com.google.dart.compiler.DartCompilerContext;
 import com.google.dart.compiler.DartSource;
 import com.google.dart.compiler.LibrarySource;
@@ -80,7 +81,7 @@ public class DartDocumentationGenerator extends AbstractBackend {
     List<ClassElement> exceptions = new ArrayList<ClassElement>(10);
     List<FieldElement> fields = new ArrayList<FieldElement>(10);
     List<MethodElement> methods = new ArrayList<MethodElement>(10);
-    for (DartNode dartNode : lib.getTopLevelNodes()) {
+    for (DartNode dartNode : getTopLevelNodes(lib)) {
       if (dartNode instanceof DartClass) {
         DartClass dartClass = (DartClass) dartNode;
         ClassElement classElement = dartClass.getSymbol();
@@ -181,6 +182,18 @@ public class DartDocumentationGenerator extends AbstractBackend {
     }
   }
 
+  /**
+   * @return all top-level declarations in the given {@link LibraryUnit}.
+   */
+  private static List<DartNode> getTopLevelNodes(LibraryUnit lib) {
+    List<DartNode> topLevelNodes = Lists.newArrayList();
+    Iterable<DartUnit> units = lib.getUnits();
+    for (DartUnit unit : units) {
+      topLevelNodes.addAll(unit.getTopLevelNodes());
+    }
+    return topLevelNodes;
+  }
+
   @Override
   public boolean isOutOfDate(DartSource src, DartCompilerContext context) {
     return true;
@@ -214,7 +227,7 @@ public class DartDocumentationGenerator extends AbstractBackend {
     stream.println("<section id=\"libraries-overview\">");
     for (LibraryUnit lib : libraries) {
       if (library == null || library.equals(lib.getName())) {
-        if (lib.getTopLevelNodes().size() > 0) {
+        if (!getTopLevelNodes(lib).isEmpty()) {
           stream.print("<h2>");
           stream.print(lib.getName());
           stream.println("</h2>");
diff --git a/compiler/java/com/google/dart/compiler/backend/js/ClosureJsErrorCode.java b/compiler/java/com/google/dart/compiler/backend/js/ClosureJsErrorCode.java
index e2328b85a9b..f3b37049733 100644
--- a/compiler/java/com/google/dart/compiler/backend/js/ClosureJsErrorCode.java
+++ b/compiler/java/com/google/dart/compiler/backend/js/ClosureJsErrorCode.java
@@ -41,4 +41,9 @@ public enum ClosureJsErrorCode implements ErrorCode {
   public SubSystem getSubSystem() {
     return SubSystem.CLOSURE_BACKEND;
   }
+
+  @Override
+  public boolean needsRecompilation() {
+    return true;
+  }
 }
\ No newline at end of file
diff --git a/compiler/java/com/google/dart/compiler/backend/js/JsErrorCode.java b/compiler/java/com/google/dart/compiler/backend/js/JsErrorCode.java
index b429724f366..abdde376fbc 100644
--- a/compiler/java/com/google/dart/compiler/backend/js/JsErrorCode.java
+++ b/compiler/java/com/google/dart/compiler/backend/js/JsErrorCode.java
@@ -41,4 +41,9 @@ public enum JsErrorCode implements ErrorCode {
   public SubSystem getSubSystem() {
     return SubSystem.JS_BACKEND;
   }
+
+  @Override
+  public boolean needsRecompilation() {
+    return true;
+  }
 }
\ No newline at end of file
diff --git a/compiler/java/com/google/dart/compiler/parser/DartParser.java b/compiler/java/com/google/dart/compiler/parser/DartParser.java
index db4ff5f24e8..71b5d62ed77 100644
--- a/compiler/java/com/google/dart/compiler/parser/DartParser.java
+++ b/compiler/java/com/google/dart/compiler/parser/DartParser.java
@@ -170,8 +170,8 @@ public class DartParser extends CompletionHooksParserBase {
     this(ctx, false);
   }
 
-  public DartParser(ParserContext ctx, Set<String> prefixes) {
-    this(ctx, false, prefixes);
+  public DartParser(ParserContext ctx, Set<String> prefixes, boolean isDietParse) {
+    this(ctx, isDietParse, prefixes);
   }
 
   public DartParser(ParserContext ctx, boolean isDietParse) {
@@ -2720,20 +2720,29 @@ public class DartParser extends CompletionHooksParserBase {
    */
   private DartBlock parseFunctionStatementBody(boolean requireSemicolonForArrow) {
     if (isDietParse) {
-      expect(Token.LBRACE);
       DartBlock emptyBlock = new DartBlock(new ArrayList<DartStatement>());
-      int nesting = 1;
-      while (nesting > 0) {
-        Token token = next();
-        switch (token) {
-          case LBRACE:
-            ++nesting;
+      if (optional(Token.ARROW)) {
+        while (true) {
+          Token token = next();
+          if (token == Token.SEMICOLON) {
             break;
-          case RBRACE:
-            --nesting;
-            break;
-          case EOS:
-            return emptyBlock;
+          }
+        }
+      } else {
+        expect(Token.LBRACE);
+        int nesting = 1;
+        while (nesting > 0) {
+          Token token = next();
+          switch (token) {
+            case LBRACE:
+              ++nesting;
+              break;
+            case RBRACE:
+              --nesting;
+              break;
+            case EOS:
+              return emptyBlock;
+          }
         }
       }
       // Return an empty block so we don't generate unparseable code.
diff --git a/compiler/java/com/google/dart/compiler/parser/ParserErrorCode.java b/compiler/java/com/google/dart/compiler/parser/ParserErrorCode.java
index 93482d41c0b..319c8955563 100644
--- a/compiler/java/com/google/dart/compiler/parser/ParserErrorCode.java
+++ b/compiler/java/com/google/dart/compiler/parser/ParserErrorCode.java
@@ -116,4 +116,9 @@ public enum ParserErrorCode implements ErrorCode {
   public SubSystem getSubSystem() {
     return SubSystem.PARSER;
   }
+
+  @Override
+  public boolean needsRecompilation() {
+    return true;
+  }
 }
\ No newline at end of file
diff --git a/compiler/java/com/google/dart/compiler/resolver/ResolverErrorCode.java b/compiler/java/com/google/dart/compiler/resolver/ResolverErrorCode.java
index 6c18e186b6b..af2c280d1f6 100644
--- a/compiler/java/com/google/dart/compiler/resolver/ResolverErrorCode.java
+++ b/compiler/java/com/google/dart/compiler/resolver/ResolverErrorCode.java
@@ -44,7 +44,8 @@ public enum ResolverErrorCode implements ErrorCode {
   CONSTRUCTOR_CANNOT_BE_STATIC("A constructor cannot be static"),
   CONSTRUCTOR_CANNOT_HAVE_RETURN_TYPE("Generative constructors cannot have return type"),
   CONST_AND_NONCONST_CONSTRUCTOR("Cannot reference to non-const constructor."),
-  CONST_CLASS_WITH_INHERITED_NONFINAL_FIELDS("Const class %s cannot have non-final, inherited field %s from class %s"),
+  CONST_CLASS_WITH_INHERITED_NONFINAL_FIELDS(
+      "Const class %s cannot have non-final, inherited field %s from class %s"),
   CONST_CLASS_WITH_NONFINAL_FIELDS("Const class %s cannot have non-final field %s"),
   CONST_CONSTRUCTOR_CANNOT_HAVE_BODY("A const constructor cannot have a body"),
   CONST_CONSTRUCTOR_MUST_CALL_CONST_SUPER("const constructor must call const super constructor"),
@@ -52,8 +53,7 @@ public enum ResolverErrorCode implements ErrorCode {
   CYCLIC_CLASS("%s causes a cycle in the supertype graph"),
   DEFAULT_CLASS_MUST_HAVE_SAME_TYPE_PARAMS(
       "default class must have the same type parameters as declared in the interface"),
-  DEFAULT_CONSTRUCTOR_UNRESOLVED(
-      "Can not resolve constructor with name '%s' in default class '%s'"),
+  DEFAULT_CONSTRUCTOR_UNRESOLVED("Can not resolve constructor with name '%s' in default class '%s'"),
   DEFAULT_CONSTRUCTOR_NUMBER_OF_REQUIRED_PARAMETERS(
       "Constructor '%s' in '%s' has %s required parameters, doesn't match '%s' in '%s' with %s"),
   DEFAULT_CONSTRUCTOR_NAMED_PARAMETERS(
@@ -63,19 +63,19 @@ public enum ResolverErrorCode implements ErrorCode {
       "Deprecated Map literal syntax. Only specify a single value type as a type argument."),
   DID_YOU_MEAN_NEW("%1$s is a %2$s. Did you mean (new %1$s)?"),
   DUPLICATED_INTERFACE("%s and %s are duplicated in the supertype graph"),
-  DUPLICATE_INITIALIZATION(ErrorSeverity.ERROR, "Duplicate initialization of '%s'"),
-  DUPLICATE_FUNCTION_EXPRESSION(ErrorSeverity.ERROR, "Duplicate function expression '%s'"),
+  DUPLICATE_INITIALIZATION("Duplicate initialization of '%s'"),
+  DUPLICATE_FUNCTION_EXPRESSION("Duplicate function expression '%s'"),
   DUPLICATE_FUNCTION_EXPRESSION_WARNING(ErrorSeverity.WARNING,
       "Function expression '%s' is hiding '%s' at %s"),
-  DUPLICATE_LOCAL_VARIABLE_ERROR(ErrorSeverity.ERROR, "Duplicate local variable '%s'"),
+  DUPLICATE_LOCAL_VARIABLE_ERROR("Duplicate local variable '%s'"),
   DUPLICATE_LOCAL_VARIABLE_WARNING(ErrorSeverity.WARNING,
       "Local variable '%s' is hiding '%s' at %s"),
   DUPLICATE_MEMBER("Duplicate member '%s'"),
   DUPLICATE_NAMED_ARGUMENT("Duplicate named parameter argument"),
-  DUPLICATE_PARAMETER(ErrorSeverity.ERROR, "Duplicate parameter '%s'"),
+  DUPLICATE_PARAMETER("Duplicate parameter '%s'"),
   DUPLICATE_PARAMETER_WARNING(ErrorSeverity.WARNING, "Parameter '%s' is hiding '%s' at %s"),
   DUPLICATE_TOP_LEVEL_DEFINITION("duplicate top-level definition '%s'"),
-  DUPLICATE_TYPE_VARIABLE(ErrorSeverity.ERROR, "Duplicate type variable '%s'"),
+  DUPLICATE_TYPE_VARIABLE("Duplicate type variable '%s'"),
   DUPLICATE_TYPE_VARIABLE_WARNING(ErrorSeverity.WARNING, "Type variable '%s' is hiding '%s' at %s"),
   EXPECTED_AN_INSTANCE_FIELD_IN_SUPER_CLASS(
       "expected an instance field in the super class, but got %s"),
@@ -150,7 +150,7 @@ public enum ResolverErrorCode implements ErrorCode {
   TYPE_NOT_ASSIGNMENT_COMPATIBLE("%s is not assignable to %s"),
   TYPE_VARIABLE_DOES_NOT_MATCH("Type variable %s does not match %s in default class %s."),
   TYPE_PARAMETERS_MUST_MATCH_EXACTLY(
-     "Type parameters in default declaration must match referenced class exactly"),
+      "Type parameters in default declaration must match referenced class exactly"),
   TYPE_VARIABLE_IN_STATIC_CONTEXT("cannot access type variable %s in static context"),
   TYPE_VARIABLE_NOT_ALLOWED_IN_IDENTIFIER("type variables are not allowed in identifier expressions"),
   WRONG_NUMBER_OF_TYPE_ARGUMENTS("%s: wrong number of type arguments (%d).  Expected %d");
@@ -186,4 +186,9 @@ public enum ResolverErrorCode implements ErrorCode {
   public SubSystem getSubSystem() {
     return SubSystem.RESOLVER;
   }
+
+  @Override
+  public boolean needsRecompilation() {
+    return true;
+  }
 }
\ No newline at end of file
diff --git a/compiler/java/com/google/dart/compiler/resolver/TypeErrorCode.java b/compiler/java/com/google/dart/compiler/resolver/TypeErrorCode.java
index ec5c0986a46..f9daf8dfa67 100644
--- a/compiler/java/com/google/dart/compiler/resolver/TypeErrorCode.java
+++ b/compiler/java/com/google/dart/compiler/resolver/TypeErrorCode.java
@@ -13,7 +13,7 @@ import com.google.dart.compiler.SubSystem;
 public enum TypeErrorCode implements ErrorCode {
   ABSTRACT_CLASS_WITHOUT_ABSTRACT_MODIFIER(
       "%s is an abstract class because it does not implement the inherited abstract members: %s"),
-  CANNOT_BE_RESOLVED("cannot resolve %s"),
+  CANNOT_BE_RESOLVED("cannot resolve %s", true),
   CANNOT_OVERRIDE_TYPED_MEMBER("cannot override %s of %s because %s is not assignable to %s"),
   CANNOT_OVERRIDE_METHOD_NOT_SUBTYPE("cannot override %s of %s because %s is not a subtype of %s"),
   CYCLIC_REFERENCE_TO_TYPE_VARIABLE(
@@ -32,18 +32,18 @@ public enum TypeErrorCode implements ErrorCode {
   INSTANTIATION_OF_CLASS_WITH_UNIMPLEMENTED_MEMBERS(
       "instantiation of class %s with the inherited abstract members: %s"),
   INTERFACE_HAS_NO_METHOD_NAMED("%s has no method named \"%s\""),
-  INTERNAL_ERROR("internal error: %s"),
+  INTERNAL_ERROR("internal error: %s", true),
   IS_STATIC_FIELD_IN("\"%s\" is a static field in \"%s\""),
   IS_STATIC_METHOD_IN("\"%s\" is a static method in \"%s\""),
   MEMBER_IS_A_CONSTRUCTOR("%s is a constructor in %s"),
   MISSING_ARGUMENT("missing argument of type %s"),
   MISSING_RETURN_VALUE("no return value; expected a value of type %s"),
   NO_SUCH_NAMED_PARAMETER("no such named parameter \"%s\" defined"),
-  NO_SUCH_TYPE("no such type \"%s\""),
+  NO_SUCH_TYPE("no such type \"%s\"", true),
   NOT_A_FUNCTION("\"%s\" is not a function"),
   NOT_A_MEMBER_OF("\"%s\" is not a member of %s"),
   NOT_A_METHOD_IN("\"%s\" is not a method in %s"),
-  NOT_A_TYPE("type \"%s\" expected, but \"%s\" found"),
+  NOT_A_TYPE("type \"%s\" expected, but \"%s\" found", true),
   OPERATOR_WRONG_OPERAND_TYPE("operand of \"%s\" must be assignable to \"%s\""),
   OVERRIDING_INHERITED_STATIC_MEMBER("overriding inherited static member %s of %s"),
   SETTER_RETURN_TYPE("Specified return type of setter '%s' is non-void"),
@@ -56,22 +56,22 @@ public enum TypeErrorCode implements ErrorCode {
   VOID("expression does not yield a value"),
   WRONG_NUMBER_OF_TYPE_ARGUMENTS("%s: wrong number of type arguments (%d), Expected %d");
 
-  private final ErrorSeverity severity;
   private final String message;
+  private final boolean needsRecompilation;
 
   /**
-   * Initialize a newly created error code to have the given message and WARNING severity.
+   * Initialize a newly created error code to have the given message.
    */
   private TypeErrorCode(String message) {
-    this(ErrorSeverity.WARNING, message);
+    this(message, false);
   }
 
   /**
-   * Initialize a newly created error code to have the given severity and message.
+   * Initialize a newly created error code to have the given message and compilation flag.
    */
-  private TypeErrorCode(ErrorSeverity severity, String message) {
-    this.severity = severity;
+  private TypeErrorCode(String message, boolean needsRecompilation) {
     this.message = message;
+    this.needsRecompilation = needsRecompilation;
   }
 
   @Override
@@ -81,11 +81,16 @@ public enum TypeErrorCode implements ErrorCode {
 
   @Override
   public ErrorSeverity getErrorSeverity() {
-    return severity;
+    return ErrorSeverity.WARNING;
   }
 
   @Override
   public SubSystem getSubSystem() {
     return SubSystem.STATIC_TYPE;
   }
+
+  @Override
+  public boolean needsRecompilation() {
+    return this.needsRecompilation;
+  }
 }
\ No newline at end of file
diff --git a/compiler/javatests/com/google/dart/compiler/MockBundleLibrarySource.java b/compiler/javatests/com/google/dart/compiler/MockBundleLibrarySource.java
index 10ec48d511c..f70cbec85b8 100644
--- a/compiler/javatests/com/google/dart/compiler/MockBundleLibrarySource.java
+++ b/compiler/javatests/com/google/dart/compiler/MockBundleLibrarySource.java
@@ -155,6 +155,7 @@ public class MockBundleLibrarySource extends UrlLibrarySource implements Library
    */
   public void remapSource(String relPath, String remappedRelPath) {
     sourceRemapping.put(relPath, remappedRelPath);
+    touchSource(relPath);
   }
 
   /**
diff --git a/compiler/javatests/com/google/dart/compiler/backend/common/TypeHeuristicImplementationTest.java b/compiler/javatests/com/google/dart/compiler/backend/common/TypeHeuristicImplementationTest.java
index 89f28cc5c6d..c2da30d4604 100644
--- a/compiler/javatests/com/google/dart/compiler/backend/common/TypeHeuristicImplementationTest.java
+++ b/compiler/javatests/com/google/dart/compiler/backend/common/TypeHeuristicImplementationTest.java
@@ -851,9 +851,13 @@ public class TypeHeuristicImplementationTest extends CompilerTestCase {
   }
 
   private DartClass getClass(DartUnit unit, String name) {
-    DartNode node = unit.getLibrary().getTopLevelNode(name);
-    if (node instanceof DartClass) {
-      return (DartClass) node;
+    for (DartNode topLevelNode : unit.getTopLevelNodes()) {
+      if (topLevelNode instanceof DartClass) {
+        DartClass dartClass = (DartClass) topLevelNode;
+        if (dartClass.getName().getTargetName().equals(name)) {
+          return dartClass;
+        }
+      }
     }
     return null;
   }
diff --git a/compiler/javatests/com/google/dart/compiler/common/ErrorExpectation.java b/compiler/javatests/com/google/dart/compiler/common/ErrorExpectation.java
index 8033bc1d629..e10948e6b80 100644
--- a/compiler/javatests/com/google/dart/compiler/common/ErrorExpectation.java
+++ b/compiler/javatests/com/google/dart/compiler/common/ErrorExpectation.java
@@ -1,7 +1,6 @@
 // Copyright (c) 2011, 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.
-
 package com.google.dart.compiler.common;
 
 import com.google.dart.compiler.DartCompilationError;
@@ -12,58 +11,88 @@ import junit.framework.Assert;
 import java.util.List;
 
 public class ErrorExpectation {
+  private final String sourceName;
   final ErrorCode errorCode;
   final int line;
   final int column;
   final int length;
 
-  public ErrorExpectation(ErrorCode errorCode, int line, int column, int length) {
+  public ErrorExpectation(String sourceName, ErrorCode errorCode, int line, int column, int length) {
+    this.sourceName = sourceName;
     this.errorCode = errorCode;
     this.line = line;
     this.column = column;
     this.length = length;
   }
 
-  public static ErrorExpectation errEx(ErrorCode errorCode, int line, int column, int length) {
-    return new ErrorExpectation(errorCode, line, column,  length);
+  public static ErrorExpectation errEx(String sourceName,
+      ErrorCode errorCode,
+      int line,
+      int column,
+      int length) {
+    sourceName = sourceName != null ? sourceName : "";
+    return new ErrorExpectation(sourceName, errorCode, line, column, length);
   }
 
-  public static void formatExpectations(StringBuffer out, List<DartCompilationError> errors,
-                                        ErrorExpectation[] expectedErrors) {
+  public static ErrorExpectation errEx(ErrorCode errorCode, int line, int column, int length) {
+    return new ErrorExpectation("", errorCode, line, column, length);
+  }
+
+  public static void formatExpectations(StringBuffer out,
+      List<DartCompilationError> errors,
+      ErrorExpectation[] expectedErrors) {
     out.append(String.format("Expected %d errors\n", expectedErrors.length));
-    for (ErrorExpectation errEx : expectedErrors) {
-      out.append(String.format("  %s (%d,%d/%d)\n", errEx.errorCode.toString(),
-                               errEx.line, errEx.column, errEx.length));
+    boolean hasExpectedSourceName = false;
+    for (ErrorExpectation expected : expectedErrors) {
+      hasExpectedSourceName |= expected.sourceName.length() != 0;
+      out.append(String.format(
+          "  %s %s (%d,%d/%d)\n",
+          expected.sourceName,
+          expected.errorCode.toString(),
+          expected.line,
+          expected.column,
+          expected.length));
     }
     out.append(String.format("Encountered %d errors\n", errors.size()));
-    for (DartCompilationError error : errors) {
-      out.append(String.format("  %s (%d,%d/%d): %s\n", error.getErrorCode().toString(),
-                               error.getLineNumber(), error.getColumnNumber(),
-                               error.getLength(), error.getMessage()));
+    for (DartCompilationError actual : errors) {
+      String sourceName =
+          hasExpectedSourceName && actual.getSource() != null ? actual.getSource().getName() : "";
+      out.append(String.format(
+          "  %s %s (%d,%d/%d): %s\n",
+          sourceName,
+          actual.getErrorCode().toString(),
+          actual.getLineNumber(),
+          actual.getColumnNumber(),
+          actual.getLength(),
+          actual.getMessage()));
     }
   }
+
   /**
    * Asserts that given list of {@link DartCompilationError} is exactly same as expected.
    */
   public static void assertErrors(List<DartCompilationError> errors,
-                                  ErrorExpectation... expectedErrors) {
+      ErrorExpectation... expectedErrors) {
     StringBuffer errorMessage = new StringBuffer();
     // count of errors
     if (errors.size() != expectedErrors.length) {
-      errorMessage.append(String.format("Wrong number of errors encountered\n",
-                                        expectedErrors.length,
-                                        errors.size()));
-
+      errorMessage.append(String.format(
+          "Wrong number of errors encountered\n",
+          expectedErrors.length,
+          errors.size()));
       formatExpectations(errorMessage, errors, expectedErrors);
     } else {
       // content of errors
       for (int i = 0; i < expectedErrors.length; i++) {
-        ErrorExpectation expectedError = expectedErrors[i];
-        DartCompilationError actualError = errors.get(i);
-        if (actualError.getErrorCode() != expectedError.errorCode
-            || actualError.getLineNumber() != expectedError.line
-            || actualError.getColumnNumber() != expectedError.column
-            || actualError.getLength() != expectedError.length) {
+        ErrorExpectation expected = expectedErrors[i];
+        DartCompilationError actual = errors.get(i);
+        String expectedSourceName = expected.sourceName;
+        String actualSourceName = actual.getSource() != null ? actual.getSource().getName() : "";
+        if (actual.getErrorCode() != expected.errorCode
+            || actual.getLineNumber() != expected.line
+            || actual.getColumnNumber() != expected.column
+            || actual.getLength() != expected.length
+            || !(expectedSourceName.length() == 0 || expectedSourceName.equals(actualSourceName))) {
           errorMessage.append(String.format("Expected errors didn't match actual\n"));
           formatExpectations(errorMessage, errors, expectedErrors);
           break;
diff --git a/compiler/javatests/com/google/dart/compiler/end2end/End2EndTests.java b/compiler/javatests/com/google/dart/compiler/end2end/End2EndTests.java
index ca78c2dd27e..fe86fbcf457 100644
--- a/compiler/javatests/com/google/dart/compiler/end2end/End2EndTests.java
+++ b/compiler/javatests/com/google/dart/compiler/end2end/End2EndTests.java
@@ -4,6 +4,7 @@
 
 package com.google.dart.compiler.end2end;
 
+import com.google.dart.compiler.end2end.inc.IncrementalCompilation2Test;
 import com.google.dart.compiler.end2end.inc.IncrementalCompilationTest;
 import com.google.dart.compiler.end2end.inc.IncrementalCompilationWithPrefixTest;
 
@@ -23,6 +24,7 @@ public class End2EndTests extends TestSetup {
     suite.addTestSuite(BasicTest.class);
     suite.addTestSuite(MainMethodTest.class);
     suite.addTestSuite(IncrementalCompilationTest.class);
+    suite.addTestSuite(IncrementalCompilation2Test.class);
     suite.addTestSuite(IncrementalCompilationWithPrefixTest.class);
     return new End2EndTests(suite);
   }
diff --git a/compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilation2Test.java b/compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilation2Test.java
new file mode 100644
index 00000000000..3ea5e90495b
--- /dev/null
+++ b/compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilation2Test.java
@@ -0,0 +1,561 @@
+// Copyright (c) 2011, 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.
+package com.google.dart.compiler.end2end.inc;
+
+import static com.google.dart.compiler.DartCompiler.EXTENSION_DEPS;
+import static com.google.dart.compiler.backend.js.AbstractJsBackend.EXTENSION_APP_JS;
+import static com.google.dart.compiler.backend.js.AbstractJsBackend.EXTENSION_JS;
+import static com.google.dart.compiler.common.ErrorExpectation.assertErrors;
+import static com.google.dart.compiler.common.ErrorExpectation.errEx;
+
+import com.google.common.collect.Lists;
+import com.google.dart.compiler.CompilerTestCase;
+import com.google.dart.compiler.DartCompilationError;
+import com.google.dart.compiler.DartCompiler;
+import com.google.dart.compiler.DartCompilerListener;
+import com.google.dart.compiler.DefaultCompilerConfiguration;
+import com.google.dart.compiler.LibrarySource;
+import com.google.dart.compiler.MockArtifactProvider;
+import com.google.dart.compiler.Source;
+import com.google.dart.compiler.backend.js.JavascriptBackend;
+import com.google.dart.compiler.resolver.ResolverErrorCode;
+import com.google.dart.compiler.resolver.TypeErrorCode;
+
+import junit.framework.AssertionFailedError;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.io.StringReader;
+import java.io.Writer;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentSkipListSet;
+
+public class IncrementalCompilation2Test extends CompilerTestCase {
+  private static final String APP = "Application.dart";
+
+  private static class IncMockArtifactProvider extends MockArtifactProvider {
+    Set<String> reads = new ConcurrentSkipListSet<String>();
+    Set<String> writes = new ConcurrentSkipListSet<String>();
+
+    @Override
+    public Reader getArtifactReader(Source source, String part, String extension) {
+      reads.add(source.getName() + "/" + extension);
+      return super.getArtifactReader(source, part, extension);
+    }
+
+    @Override
+    public Writer getArtifactWriter(Source source, String part, String extension) {
+      writes.add(source.getName() + "/" + extension);
+      return super.getArtifactWriter(source, part, extension);
+    }
+
+    void resetReadsAndWrites() {
+      reads.clear();
+      writes.clear();
+    }
+  }
+
+  private DefaultCompilerConfiguration config;
+  private IncMockArtifactProvider provider;
+  private MemoryLibrarySource appSource;
+  private long appSourceLastModified = 0;
+  private String appSourceContent = makeCode(
+      "// filler filler filler filler filler filler filler filler filler filler filler",
+      "#library('application');",
+      "#source('A.dart');",
+      "#source('B.dart');",
+      "#source('C.dart');",
+      "");
+  private final List<DartCompilationError> errors = Lists.newArrayList();
+
+  @Override
+  protected void setUp() throws Exception {
+    config = new DefaultCompilerConfiguration(new JavascriptBackend()) {
+      @Override
+      public boolean incremental() {
+        return true;
+      }
+    };
+    provider = new IncMockArtifactProvider();
+    appSource = new MemoryLibrarySource(APP, "<not-used>") {
+      @Override
+      public long getLastModified() {
+        return appSourceLastModified;
+      }
+
+      @Override
+      public Reader getSourceReader() throws IOException {
+        return new StringReader(appSourceContent);
+      }
+    };
+    appSource.setContent("A.dart", "");
+    appSource.setContent("B.dart", "");
+    appSource.setContent("C.dart", "");
+  }
+
+  @Override
+  protected void tearDown() {
+    config = null;
+    provider = null;
+    appSource = null;
+  }
+
+  /**
+   * "not_hole" is referenced using "super" qualifier, so is not affected by declaring top-level
+   * field with same name.
+   */
+  public void test_useQualifiedFieldReference_ignoreTopLevelDeclaration() {
+    appSource.setContent(
+        "B.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class A {",
+            "  int not_hole;",
+            "}",
+            ""));
+    appSource.setContent(
+        "C.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class B extends A {",
+            "  int bar() {",
+            "    return super.not_hole;", // qualified reference
+            "  }",
+            "}",
+            ""));
+    compile();
+    assertErrors(errors);
+    // Update units and compile.
+    appSource.setContent(
+        "A.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "int not_hole;",
+            ""));
+    compile();
+    // TODO(scheglov) Fix this after 1159
+    //assertErrors(errors, errEx(ResolverErrorCode.DUPLICATE_LOCAL_VARIABLE_WARNING, -1, 7, 20));
+    // B should be compiled because it now conflicts with A.
+    // C should not be compiled, because it reference "not_hole" field, not top-level variable.
+    didWrite("A.dart", EXTENSION_JS);
+    didWrite("B.dart", EXTENSION_JS);
+    didNotWrite("C.dart", EXTENSION_JS);
+    assertAppBuilt();
+  }
+
+  /**
+   * Referenced "hole" identifier can not be resolved, but when we declare it in A, then B should be
+   * recompiled and error message disappear.
+   */
+  public void test_useUnresolvedField_recompileOnTopLevelDeclaration() {
+    appSource.setContent(
+        "B.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class A {",
+            "  int foo() {",
+            "    return hole;", // no such field
+            "  }",
+            "}",
+            ""));
+    compile();
+    assertErrors(errors, errEx(TypeErrorCode.CANNOT_BE_RESOLVED, 4, 12, 4));
+    // Update units and compile.
+    appSource.setContent(
+        "A.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "int hole;",
+            ""));
+    compile();
+    // A and B should be compiled.
+    didWrite("A.dart", EXTENSION_JS);
+    didWrite("B.dart", EXTENSION_JS);
+    assertAppBuilt();
+    // "hole" was filled with top-level field.
+    assertErrors(errors);
+  }
+
+  /**
+   * Test for "hole" feature. If we use unqualified invocation and add/remove top-level method, this
+   * should cause compilation of invocation unit.
+   */
+  public void test_isMethodHole_useUnqualifiedInvocation() {
+    appSource.setContent(
+        "B.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class A {",
+            "  foo() {}",
+            "}",
+            ""));
+    appSource.setContent(
+        "C.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class B extends A {",
+            "  int bar() {",
+            "    foo();", // unqualified invocation
+            "  }",
+            "}",
+            ""));
+    compile();
+    assertErrors(errors);
+    // Declare top-level foo(), now invocation of foo() in B should be bound to this top-level.
+    {
+      appSource.setContent(
+          "A.dart",
+          makeCode(
+              "// filler filler filler filler filler filler filler filler filler filler filler",
+              "foo() {}",
+              ""));
+      compile();
+      // B should be compiled because it also declares foo(), so produces "shadow" conflict.
+      // C should be compiled because it has unqualified invocation which was declared in A.
+      didWrite("A.dart", EXTENSION_JS);
+      didWrite("B.dart", EXTENSION_JS);
+      didWrite("C.dart", EXTENSION_JS);
+      assertAppBuilt();
+    }
+    // Remove top-level foo(), so invocation of foo() in B should be bound to the super class.
+    {
+      appSource.setContent("A.dart", "");
+      compile();
+      // B should be compiled because it also declares foo(), so produces "shadow" conflict.
+      // C should be compiled because it has unqualified invocation which was declared in A.
+      didWrite("A.dart", EXTENSION_JS);
+      didWrite("B.dart", EXTENSION_JS);
+      didWrite("C.dart", EXTENSION_JS);
+    }
+  }
+
+  /**
+   * Test for "hole" feature. If we use qualified invocation and add/remove top-level method, this
+   * should not cause compilation of invocation unit.
+   */
+  public void test_notMethodHole_useQualifiedInvocation() {
+    appSource.setContent(
+        "B.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class A {",
+            "  foo() {}",
+            "}",
+            ""));
+    appSource.setContent(
+        "C.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class B extends A {",
+            "  int bar() {",
+            "    super.foo();", // qualified invocation
+            "  }",
+            "}",
+            ""));
+    compile();
+    assertErrors(errors);
+    // Declare top-level foo(), but it is ignored.
+    {
+      appSource.setContent(
+          "A.dart",
+          makeCode(
+              "// filler filler filler filler filler filler filler filler filler filler filler",
+              "foo() {}",
+              ""));
+      compile();
+      // B should be compiled because it also declares foo(), so produces "shadow" conflict.
+      // C should not be compiled because.
+      didWrite("A.dart", EXTENSION_JS);
+      didWrite("B.dart", EXTENSION_JS);
+      didNotWrite("C.dart", EXTENSION_JS);
+      assertAppBuilt();
+    }
+  }
+
+  /**
+   * Test for "hole" feature. If we use unqualified access and add/remove top-level field, this
+   * should cause compilation of invocation unit.
+   */
+  public void test_fieldHole_useUnqualifiedAccess() {
+    appSource.setContent(
+        "B.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class A {",
+            "  var foo;",
+            "}",
+            ""));
+    appSource.setContent(
+        "C.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class B extends A {",
+            "  int bar() {",
+            "    foo = 0;", // unqualified access
+            "  }",
+            "}",
+            ""));
+    compile();
+    assertErrors(errors);
+    // Declare top-level "foo", now access to "foo" in B should be bound to this top-level.
+    {
+      appSource.setContent(
+          "A.dart",
+          makeCode(
+              "// filler filler filler filler filler filler filler filler filler filler filler",
+              "var foo;",
+              ""));
+      compile();
+      // B should be compiled because it also declares "foo", so produces "shadow" conflict.
+      // C should be compiled because it has unqualified invocation which was declared in A.
+      didWrite("A.dart", EXTENSION_JS);
+      didWrite("B.dart", EXTENSION_JS);
+      didWrite("C.dart", EXTENSION_JS);
+      assertAppBuilt();
+    }
+    // Remove top-level "foo", so access to "foo" in B should be bound to the super class.
+    {
+      appSource.setContent("A.dart", "");
+      compile();
+      // B should be compiled because it also declares "foo", so produces "shadow" conflict.
+      // C should be compiled because it has unqualified access which was declared in A.
+      didWrite("A.dart", EXTENSION_JS);
+      didWrite("B.dart", EXTENSION_JS);
+      didWrite("C.dart", EXTENSION_JS);
+    }
+  }
+
+  /**
+   * Test for "hole" feature. If we use qualified access and add/remove top-level field, this should
+   * not cause compilation of invocation unit.
+   */
+  public void test_gieldHole_useQualifiedAccess() {
+    appSource.setContent(
+        "B.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class A {",
+            "  var foo;",
+            "}",
+            ""));
+    appSource.setContent(
+        "C.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class B extends A {",
+            "  int bar() {",
+            "    super.foo = 0;", // qualified access
+            "  }",
+            "}",
+            ""));
+    compile();
+    assertErrors(errors);
+    // Declare top-level "foo", but it is ignored.
+    {
+      appSource.setContent(
+          "A.dart",
+          makeCode(
+              "// filler filler filler filler filler filler filler filler filler filler filler",
+              "var foo;",
+              ""));
+      compile();
+      // B should be compiled because it also declares "foo", so produces "shadow" conflict.
+      // C should not be compiled because it has qualified access to "foo".
+      didWrite("A.dart", EXTENSION_JS);
+      didWrite("B.dart", EXTENSION_JS);
+      didNotWrite("C.dart", EXTENSION_JS);
+      assertAppBuilt();
+    }
+  }
+
+  public void test_declareTopLevel_conflictWithLocalVariable() {
+    appSource.setContent(
+        "B.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "methodB() {",
+            "  var symbolDependency_foo;",
+            "}"));
+    compile();
+    assertErrors(errors);
+    // Update units and compile.
+    appSource.setContent(
+        "A.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "var symbolDependency_foo;"));
+    compile();
+    // Now there is top-level declarations conflict between A and B.
+    // So, B should be compiled.
+    didWrite("B.dart", EXTENSION_JS);
+    // But application should be build.
+    assertAppBuilt();
+    // Because B was compiled, it has warning.
+    assertErrors(errors, errEx(ResolverErrorCode.DUPLICATE_LOCAL_VARIABLE_WARNING, 3, 7, 20));
+  }
+
+  public void test_undeclareTopLevel_conflictWithLocalVariable() {
+    appSource.setContent(
+        "A.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "var duplicate;"));
+    appSource.setContent(
+        "B.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "bar() {",
+            "  var duplicate;",
+            "}"));
+    compile();
+    assertErrors(errors, errEx(ResolverErrorCode.DUPLICATE_LOCAL_VARIABLE_WARNING, 3, 7, 9));
+    // Update units and compile.
+    appSource.setContent("A.dart", "");
+    compile();
+    // Top-level declaration in A was removed, so no conflict.
+    // So:
+    // ... B should be recompiled.
+    didWrite("B.dart", EXTENSION_JS);
+    // ... but application should be rebuild.
+    assertAppBuilt();
+    // Because B was recompiled, it has no warning.
+    assertErrors(errors);
+  }
+
+  /**
+   * Removes A, so changes set of top level units and forces compilation.
+   */
+  public void test_removeOneSource() {
+    appSource.setContent(
+        "A.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "var duplicate;"));
+    appSource.setContent(
+        "B.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "bar() {",
+            "  var duplicate;",
+            "}"));
+    compile();
+    assertErrors(errors, errEx(ResolverErrorCode.DUPLICATE_LOCAL_VARIABLE_WARNING, 3, 7, 9));
+    // Exclude A and compile.
+    appSourceLastModified++;
+    appSourceContent =
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "#library('app');",
+            "#source('B.dart');",
+            "");
+    compile();
+    // Now there is top-level declarations conflict between A and B.
+    // So:
+    // ... B should be recompiled.
+    didWrite("B.dart", EXTENSION_JS);
+    // ... but application should be rebuild.
+    didWrite(APP, EXTENSION_DEPS);
+    didWrite(APP, EXTENSION_APP_JS);
+    // Because B was recompiled, it has no warning.
+    assertErrors(errors);
+  }
+
+  public void test_declareField_conflictWithLocalVariable() {
+    appSource.setContent(
+        "A.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class A {",
+            "}",
+            ""));
+    appSource.setContent(
+        "B.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class B extends A {",
+            "  foo() {",
+            "    var bar;",
+            "  }",
+            "}",
+            ""));
+    compile();
+    assertErrors(errors);
+    // Update units and compile.
+    appSource.setContent(
+        "A.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "class A {",
+            "  var bar;",
+            "}",
+            ""));
+    compile();
+    // B depends on A class, so compiled.
+    didWrite("B.dart", EXTENSION_JS);
+    assertAppBuilt();
+    // Because B was compiled, it has warning.
+    assertErrors(errors, errEx(ResolverErrorCode.DUPLICATE_LOCAL_VARIABLE_WARNING, 4, 9, 3));
+  }
+
+  public void test_declareTopLevelVariable_conflictOtherTopLevelVariable() {
+    appSource.setContent(
+        "A.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "var conflict;",
+            ""));
+    compile();
+    assertErrors(errors);
+    // Update units and compile.
+    appSource.setContent(
+        "B.dart",
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler filler",
+            "var conflict;",
+            ""));
+    compile();
+    // A symbols intersect with new B symbols, so we compile A too.
+    // Both A and B have errors.
+    assertErrors(
+        errors,
+        errEx("A.dart", ResolverErrorCode.DUPLICATE_TOP_LEVEL_DEFINITION, 2, 5, 8),
+        errEx("B.dart", ResolverErrorCode.DUPLICATE_TOP_LEVEL_DEFINITION, 2, 5, 8));
+  }
+
+  private void assertAppBuilt() {
+    didWrite(APP, EXTENSION_DEPS);
+    didWrite(APP, EXTENSION_APP_JS);
+  }
+
+  private void compile() {
+    compile(appSource);
+  }
+
+  private void compile(LibrarySource lib) {
+    try {
+      provider.resetReadsAndWrites();
+      errors.clear();
+      DartCompilerListener listener = new DartCompilerListener.Empty() {
+        @Override
+        public void onError(DartCompilationError event) {
+          errors.add(event);
+        }
+      };
+      DartCompiler.compileLib(lib, config, provider, listener);
+    } catch (IOException e) {
+      throw new AssertionFailedError("Unexpected IOException: " + e.getMessage());
+    }
+  }
+
+  private void didWrite(String sourceName, String extension) {
+    String spec = sourceName + "/" + extension;
+    assertTrue("Expected write: " + spec, provider.writes.contains(spec));
+  }
+
+  private void didNotWrite(String sourceName, String extension) {
+    String spec = sourceName + "/" + extension;
+    assertFalse("Didn't expect write: " + spec, provider.writes.contains(spec));
+  }
+}
diff --git a/compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilationTest.java b/compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilationTest.java
index 05273388398..457cae7c2c7 100644
--- a/compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilationTest.java
+++ b/compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilationTest.java
@@ -4,15 +4,15 @@
 
 package com.google.dart.compiler.end2end.inc;
 
-import static com.google.dart.compiler.DartCompiler.EXTENSION_API;
 import static com.google.dart.compiler.DartCompiler.EXTENSION_DEPS;
-import static com.google.dart.compiler.backend.js.JavascriptBackend.EXTENSION_APP_JS;
-import static com.google.dart.compiler.backend.js.JavascriptBackend.EXTENSION_JS;
+import static com.google.dart.compiler.backend.js.AbstractJsBackend.EXTENSION_APP_JS;
+import static com.google.dart.compiler.backend.js.AbstractJsBackend.EXTENSION_JS;
 
+import com.google.common.collect.Lists;
 import com.google.dart.compiler.CompilerTestCase;
+import com.google.dart.compiler.DartCompilationError;
 import com.google.dart.compiler.DartCompiler;
 import com.google.dart.compiler.DartCompilerListener;
-import com.google.dart.compiler.DartCompilerListenerTest;
 import com.google.dart.compiler.DefaultCompilerConfiguration;
 import com.google.dart.compiler.LibrarySource;
 import com.google.dart.compiler.MockArtifactProvider;
@@ -25,7 +25,7 @@ import junit.framework.AssertionFailedError;
 import java.io.IOException;
 import java.io.Reader;
 import java.io.Writer;
-import java.net.URISyntaxException;
+import java.util.List;
 import java.util.Set;
 import java.util.concurrent.ConcurrentSkipListSet;
 
@@ -63,6 +63,8 @@ public class IncrementalCompilationTest extends CompilerTestCase {
   private MockBundleLibrarySource someLibSource;
   private MockBundleLibrarySource someImplLibSource;
 
+  private final List<DartCompilationError> errors = Lists.newArrayList();
+
   @Override
   protected void setUp() throws Exception {
     config = new DefaultCompilerConfiguration(new JavascriptBackend()) {
@@ -88,7 +90,7 @@ public class IncrementalCompilationTest extends CompilerTestCase {
     someImplLibSource = null;
   }
 
-  public void testRemoveDeps() throws URISyntaxException {
+  public void testRemoveDeps() throws Exception {
     compile();
 
     MockBundleLibrarySource myNuke5AppSource = new MockBundleLibrarySource(
@@ -98,28 +100,25 @@ public class IncrementalCompilationTest extends CompilerTestCase {
     myNuke5AppSource.remapSource("my.dart", "my.no5ref.dart");
     myNuke5AppSource.removeSource("myother5.dart");
 
-    compile(myNuke5AppSource, null);
+    compile(myNuke5AppSource);
   }
 
   public void testFullCompile() {
     compile();
 
     // Assert that all artifacts are written.
-    didWrite("someimpl.dart", EXTENSION_JS, provider);
-    didWrite("someimpl.lib.dart", EXTENSION_API, provider);
-    didWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
+    didWrite("someimpl.dart", EXTENSION_JS);
+    didWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didWrite("some.dart", EXTENSION_JS, provider);
-    didWrite("some.lib.dart", EXTENSION_API, provider);
-    didWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didWrite("some.dart", EXTENSION_JS);
+    didWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother0.dart", EXTENSION_JS, provider);
-    didWrite("myother1.dart", EXTENSION_JS, provider);
-    didWrite("myother2.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_JS, provider);
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother0.dart", EXTENSION_JS);
+    didWrite("myother1.dart", EXTENSION_JS);
+    didWrite("myother2.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_JS);
   }
 
   public void testNoOpRecompile() {
@@ -129,21 +128,18 @@ public class IncrementalCompilationTest extends CompilerTestCase {
     compile();
 
     // Assert we didn't write anything.
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("my.dart", EXTENSION_JS, provider);
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
-    didNotWrite("my.app.dart", EXTENSION_API, provider);
-    didNotWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didNotWrite("my.app.dart", EXTENSION_JS, provider);
+    didNotWrite("my.dart", EXTENSION_JS);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
+    didNotWrite("my.app.dart", EXTENSION_DEPS);
+    didNotWrite("my.app.dart", EXTENSION_JS);
   }
 
   public void testTouchOneSource() {
@@ -155,23 +151,20 @@ public class IncrementalCompilationTest extends CompilerTestCase {
 
     // We just bumped the timestamp on my.dart, so only my.dart.js and my.app.js should be changed.
     // At present, the app's deps and api will be rewritten. This might be optimized later.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
 
     // Nothing else should have changed.
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
   public void testNormalizationTracking() {
@@ -190,24 +183,21 @@ public class IncrementalCompilationTest extends CompilerTestCase {
     // We just bumped the timestamp on myother7.dart, so only myother7.dart.js and my.app.js should
     // be changed. At present, the app's deps and api will be rewritten.
 
-    didWrite("myother7.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
+    didWrite("myother7.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
 
     // Nothing else should have changed.
-    didNotWrite("my.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("my.dart", EXTENSION_JS);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
   public void testKnockout_jsArtifact() {
@@ -219,372 +209,293 @@ public class IncrementalCompilationTest extends CompilerTestCase {
 
     // At present, knocking out a js artifact will force an update of the library's api and
     // deps. This could be optimized.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
 
     // Assert that everything else was left alone.
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
-  }
-
-  public void testKnockout_intfArtifact() {
-    compile();
-
-    provider.resetReadsAndWrites();
-    provider.removeArtifact("my.app.dart", "", EXTENSION_API);
-    compile();
-
-    // At present, knocking out an api artifact will force an update of the library's units
-    // and deps. This could be optimized.
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother0.dart", EXTENSION_JS, provider);
-    didWrite("myother1.dart", EXTENSION_JS, provider);
-    didWrite("myother2.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-
-    // Assert that everything else was left alone.
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
-
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
   public void testChangeImplementation_methodBody() {
     compile();
 
     provider.resetReadsAndWrites();
-    someImplLibSource.touchSource("someimpl.dart");
     someImplLibSource.remapSource("someimpl.dart", "someimpl.bodychange.dart");
     compile();
 
-    // Changed someimpl.dart, so it, its library, and the compiled app should be written, but not
-    // units that depend upon it.
-    didWrite("someimpl.dart", EXTENSION_JS, provider);
-    didWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
-    didWrite("someimpl.lib.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    // Changed someimpl.dart, so it, its library, and the compiled app should be written.
+    didWrite("someimpl.dart", EXTENSION_JS);
+    didWrite("someimpl.lib.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    // We've switched to (unit -> unit) dependency, so should be recompiled too.
+    didWrite("some.dart", EXTENSION_JS);
+    didWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("my.dart", EXTENSION_JS, provider);
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
-    didNotWrite("my.app.dart", EXTENSION_API, provider);
-    didNotWrite("my.app.dart", EXTENSION_DEPS, provider);
+    didNotWrite("my.dart", EXTENSION_JS);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
+    didNotWrite("my.app.dart", EXTENSION_DEPS);
   }
 
   public void testChangeApi_newStaticMethod() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother0.dart");
     myAppSource.remapSource("myother0.dart", "myother0.newstaticmethod.dart");
     compile();
 
-    // Added a new static method to Other0, which should force a recompile of my.dart, because the
-    // latter contains a reference to one of its static methods.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother0.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    // Added a new static method to Other0, which should force a recompile of my.dart,
+    // because the latter contains a reference to one of its static methods.
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother0.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
 
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
   public void testChangeApi_staticFieldRef() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother3.dart");
     myAppSource.remapSource("myother3.dart", "myother3.newstaticfield.dart");
     compile();
 
-    // Added a new static method to Other0, which should force a recompile of my.dart, because the
-    // latter contains a reference to one of its static methods.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother3.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    // Added a new static field to Other0, which should force a recompile of my.dart,
+    // because the latter contains a reference to one of its static methods.
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother3.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
 
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
   public void testChangeApi_viaTypeParamBound() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother4.dart");
     myAppSource.remapSource("myother4.dart", "myother4.newstaticfield.dart");
     compile();
 
-    // Added a new static method to Other0, which should force a recompile of my.dart, because the
-    // latter contains a reference to one of its static methods.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother4.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    // Added a new static field to Other0, which should force a recompile of my.dart,
+    // because the latter contains a reference to one of its static methods.
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother4.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
 
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
   public void testChangeApi_returnTypeChange() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother0.dart");
     myAppSource.remapSource("myother0.dart", "myother0.returntypechange.dart");
     compile();
 
-    // Changed a return type in Other0, which should force a recompile of my.dart, because
-    // the latter contains a reference to one of its static methods.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother0.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    // Changed a return type in Other0, which should force a recompile of my.dart,
+    // because the latter contains a reference to one of its static methods.
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother0.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
 
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
   public void testChangeApi_globalVarChange() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother0.dart");
     myAppSource.remapSource("myother0.dart", "myother0.globalvarchange.dart");
     compile();
 
-    // Changed a return type in Other0, which should force a recompile of my.dart, because
-    // the latter contains a reference to one of its static methods.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother0.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    // Changed a top-level variable type in Other0, which should force a recompile of my.dart,
+    // because the latter contains a reference to one of its static methods.
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother0.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
   }
 
   public void testChangeApi_globalFunctionChange() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother0.dart");
     myAppSource.remapSource("myother0.dart", "myother0.globalfunctionchange.dart");
     compile();
 
-    // Changed a return type in Other0, which should force a recompile of my.dart, because
-    // the latter contains a reference to one of its static methods.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother0.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    // Changed a return type in Other0, which should force a recompile of my.dart,
+    // because the latter contains a reference to one of its static methods.
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother0.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
   }
 
   public void testChangeApi_viaNew() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother1.dart");
     myAppSource.remapSource("myother1.dart", "myother1.change.dart");
     compile();
 
-    // Changed the api of Other1, which should force a recompile of my.dart, because the
-    // latter intantiates one of its classes.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother1.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    // Changed the api of Other1, which should force a recompile of my.dart,
+    // because the latter instantiates one of its classes.
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother1.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
 
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
   public void testChangeApi_viaSubclassing() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother2.dart");
     myAppSource.remapSource("myother2.dart", "myother2.change.dart");
     compile();
 
-    // Changed the api of Other2, which should force a recompile of my.dart, because the
-    // latter subclasses one of its classes.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother2.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    // Changed the api of Other2, which should force a recompile of my.dart,
+    // because the latter subclasses one of its classes.
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother2.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
 
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
   }
 
   public void testChangeApi_inLibrary() {
     compile();
 
     provider.resetReadsAndWrites();
-    someLibSource.touchSource("some.dart");
     someLibSource.remapSource("some.dart", "some.newmethod.dart");
-    someImplLibSource.touchSource("someimpl.dart");
     someImplLibSource.remapSource("someimpl.dart", "someimpl.change.dart");
     compile();
 
     // We changed both the interface and implementation libraries, so almost everything should have
     // been recompiled.
-    didWrite("someimpl.dart", EXTENSION_JS, provider);
-    didWrite("someimpl.lib.dart", EXTENSION_API, provider);
-    didWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
+    didWrite("someimpl.dart", EXTENSION_JS);
+    didWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didWrite("some.dart", EXTENSION_JS, provider);
-    didWrite("some.lib.dart", EXTENSION_API, provider);
-    didWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didWrite("some.dart", EXTENSION_JS);
+    didWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
 
     // Except the "others", which have no dependency on the library.
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
-
-    // And the app's api, which also hasn't changed.
-    didNotWrite("my.app.dart", EXTENSION_API, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
   public void testChangeApi_inImplLibrary() {
     compile();
 
     provider.resetReadsAndWrites();
-    someImplLibSource.touchSource("someimpl.dart");
     someImplLibSource.remapSource("someimpl.dart", "someimpl.change.dart");
     compile();
 
     // Assert that only the interface and implementation library were recompiled.
-    didWrite("someimpl.dart", EXTENSION_JS, provider);
-    didWrite("someimpl.lib.dart", EXTENSION_API, provider);
-    didWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
+    didWrite("someimpl.dart", EXTENSION_JS);
+    didWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didWrite("some.dart", EXTENSION_JS, provider);
-    didWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didWrite("some.dart", EXTENSION_JS);
+    didWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
 
     // The app should remain untouched.
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
-    didNotWrite("my.dart", EXTENSION_JS, provider);
-    didNotWrite("my.app.dart", EXTENSION_API, provider);
-    didNotWrite("my.app.dart", EXTENSION_DEPS, provider);
-
-    // As should the api of some.lib.
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
+    didNotWrite("my.dart", EXTENSION_JS);
+    didNotWrite("my.app.dart", EXTENSION_DEPS);
   }
 
   public void testChangeApi_inInterface() {
     compile();
 
     provider.resetReadsAndWrites();
-    someLibSource.touchSource("some.dart");
     someLibSource.remapSource("some.dart", "some.intfchange.dart");
     compile();
 
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
-    didNotWrite("my.app.dart", EXTENSION_API, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
 
     // Assert we recompiled both some.dart and someimpl.dart, as well as my.dart.
     // (someimpl.dart is recompiled because its interface in some.dart changed)
-    didWrite("someimpl.dart", EXTENSION_JS, provider);
-    didWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
+    didWrite("someimpl.dart", EXTENSION_JS);
+    didWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didWrite("some.dart", EXTENSION_JS, provider);
-    didWrite("some.lib.dart", EXTENSION_API, provider);
-    didWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didWrite("some.dart", EXTENSION_JS);
+    didWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
   }
 
   // TODO(jgw): Bug 5319907.
@@ -592,169 +503,148 @@ public class IncrementalCompilationTest extends CompilerTestCase {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother0.dart");
     myAppSource.remapSource("myother0.dart", "myother0.fillthehole.dart");
     compile();
 
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
 
     // Both myother0.dart and my.dart should be recompiled.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother0.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother0.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
   }
 
   public void testMethodHole() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother0.dart");
     myAppSource.remapSource("myother0.dart", "myother0.fillthemethodhole.dart");
-    compile("my.dart", "methodHole is a class. Did you mean (new methodHole)?", 48, 5);
-  }
-
-  public void testTheNotHole() {
     compile();
-
-    provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother0.dart");
-    myAppSource.remapSource("myother0.dart", "myother0.fillthenothole.dart");
-    compile();
-
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
-
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
-
-    didNotWrite("my.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
-
-    // Only myother0.dart should be recompiled.
-    didWrite("myother0.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
   }
 
   public void testQualifiedFieldRef() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother5.dart");
     myAppSource.remapSource("myother5.dart", "myother5.change.dart");
     compile();
 
-    // Changed the api of Other5, which should force a recompile of my.dart, because the
-    // latter includes a qualified reference to one of its instance fields.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother5.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    // Changed the api of Other5, which should force a recompile of my.dart,
+    // because the latter includes a qualified reference to one of its instance fields.
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother5.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
 
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
   public void testQualifiedMethodRef() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother6.dart");
     myAppSource.remapSource("myother6.dart", "myother6.change.dart");
     compile();
 
-    // Changed the api of Other6, which should force a recompile of my.dart, because the
-    // latter includes a qualified reference to one of its instance methods.
-    didWrite("my.dart", EXTENSION_JS, provider);
-    didWrite("myother6.dart", EXTENSION_JS, provider);
-    didWrite("my.app.dart", EXTENSION_API, provider);
-    didWrite("my.app.dart", EXTENSION_DEPS, provider);
-    didWrite("my.app.dart", EXTENSION_APP_JS, provider);
+    // Changed the api of Other6, which should force a recompile of my.dart,
+    // because the latter includes a qualified reference to one of its instance methods.
+    didWrite("my.dart", EXTENSION_JS);
+    didWrite("myother6.dart", EXTENSION_JS);
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
 
-    didNotWrite("someimpl.dart", EXTENSION_JS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS, provider);
-    didNotWrite("someimpl.lib.dart", EXTENSION_API, provider);
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("some.dart", EXTENSION_JS, provider);
-    didNotWrite("some.lib.dart", EXTENSION_API, provider);
-    didNotWrite("some.lib.dart", EXTENSION_DEPS, provider);
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
 
-    didNotWrite("myother0.dart", EXTENSION_JS, provider);
-    didNotWrite("myother1.dart", EXTENSION_JS, provider);
-    didNotWrite("myother2.dart", EXTENSION_JS, provider);
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
   public void testRemoveDepClass() {
     compile();
 
     provider.resetReadsAndWrites();
-    myAppSource.touchSource("myother5.dart");
     myAppSource.remapSource("myother5.dart", "myother5.change.dart");
-    myAppSource.touchSource("myother6.dart");
     myAppSource.remapSource("myother6.dart", "myother6.removeclass.dart");
     compile();
 
-    // TODO
+    // Changed myother6.dart, which should force a recompile of myother5.dart,
+    // because the latter had a qualified reference to one of its classes.
+    didWrite("myother5.dart", EXTENSION_JS);
+    didWrite("myother6.dart", EXTENSION_JS);
+
+    didWrite("my.dart", EXTENSION_JS);
+    // Because of the previous changes my.app.dart is also recompile.
+    didWrite("my.app.dart", EXTENSION_DEPS);
+    didWrite("my.app.dart", EXTENSION_APP_JS);
+
+    // No changes in not related units.
+    didNotWrite("someimpl.dart", EXTENSION_JS);
+    didNotWrite("someimpl.lib.dart", EXTENSION_DEPS);
+
+    didNotWrite("some.dart", EXTENSION_JS);
+    didNotWrite("some.lib.dart", EXTENSION_DEPS);
+
+    didNotWrite("myother0.dart", EXTENSION_JS);
+    didNotWrite("myother1.dart", EXTENSION_JS);
+    didNotWrite("myother2.dart", EXTENSION_JS);
   }
 
-  public void testMergeFiles() throws URISyntaxException {
+  public void testMergeFiles() throws Exception {
     compile();
 
     MockBundleLibrarySource myMergedAppSource = new MockBundleLibrarySource(
       IncrementalCompilationTest.class.getClassLoader(),
       TEST_BASE_PATH, "my.merged.app.dart", "my.app.dart");
 
-    compile(myMergedAppSource, null);
+    compile(myMergedAppSource);
   }
 
   private void compile() {
-    compile(null);
+    compile(myAppSource);
   }
 
-  private void compile(String srcName, Object... errors) {
-    compile(myAppSource, srcName, errors);
-  }
-
-  private void compile(LibrarySource lib, String srcName, Object... errors) {
+  private void compile(LibrarySource lib) {
     try {
-      DartCompilerListener listener = new DartCompilerListenerTest(srcName, errors);
+      errors.clear();
+      DartCompilerListener listener = new DartCompilerListener.Empty() {
+        @Override
+        public void onError(DartCompilationError event) {
+          errors.add(event);
+        }
+      };
       DartCompiler.compileLib(lib, config, provider, listener);
     } catch (IOException e) {
       throw new AssertionFailedError("Unexpected IOException: " + e.getMessage());
     }
   }
 
-  private void didWrite(String sourceName, String extension, IncMockArtifactProvider provider) {
+  private void didWrite(String sourceName, String extension) {
     String spec = sourceName + "/" + extension;
     assertTrue("Expected write: " + spec, provider.writes.contains(spec));
   }
 
-  private void didNotWrite(String sourceName, String extension, IncMockArtifactProvider provider) {
+  private void didNotWrite(String sourceName, String extension) {
     String spec = sourceName + "/" + extension;
     assertFalse("Didn't expect write: " + spec, provider.writes.contains(spec));
   }
diff --git a/compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilationWithPrefixTest.java b/compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilationWithPrefixTest.java
index 41148f62be7..680108d410d 100644
--- a/compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilationWithPrefixTest.java
+++ b/compiler/javatests/com/google/dart/compiler/end2end/inc/IncrementalCompilationWithPrefixTest.java
@@ -4,7 +4,6 @@
 
 package com.google.dart.compiler.end2end.inc;
 
-import static com.google.dart.compiler.DartCompiler.EXTENSION_API;
 import static com.google.dart.compiler.DartCompiler.EXTENSION_DEPS;
 import static com.google.dart.compiler.backend.js.AbstractJsBackend.EXTENSION_APP_JS;
 import static com.google.dart.compiler.backend.js.AbstractJsBackend.EXTENSION_JS;
@@ -98,12 +97,11 @@ public class IncrementalCompilationWithPrefixTest extends CompilerTestCase {
     someLibSource.remapSource("some.prefixable.lib.dart", "some.prefixable.modified.lib.dart");
     compile();
 
-    didWrite("my.unprefixed.app.dart", EXTENSION_JS, provider);
-    didWrite("my.unprefixed.app.dart", EXTENSION_APP_JS, provider);
-    didWrite("my.unprefixed.app.dart", EXTENSION_DEPS, provider);
-    didWrite("some.prefixable.lib.dart", EXTENSION_JS, provider);
-    didWrite("some.prefixable.lib.dart", EXTENSION_DEPS, provider);
-    didWrite("some.prefixable.lib.dart", EXTENSION_API, provider);
+    didWrite("my.unprefixed.app.dart", EXTENSION_JS);
+    didWrite("my.unprefixed.app.dart", EXTENSION_APP_JS);
+    didWrite("my.unprefixed.app.dart", EXTENSION_DEPS);
+    didWrite("some.prefixable.lib.dart", EXTENSION_JS);
+    didWrite("some.prefixable.lib.dart", EXTENSION_DEPS);
   }
 
   public void testModifyPrefixedLib() {
@@ -122,12 +120,11 @@ public class IncrementalCompilationWithPrefixTest extends CompilerTestCase {
     someLibSource.remapSource("some.prefixable.lib.dart", "some.prefixable.modified.lib.dart");
     compile();
 
-    didWrite("my.prefixed.app.dart", EXTENSION_JS, provider);
-    didWrite("my.prefixed.app.dart", EXTENSION_APP_JS, provider);
-    didWrite("my.prefixed.app.dart", EXTENSION_DEPS, provider);
-    didWrite("some.prefixable.lib.dart", EXTENSION_JS, provider);
-    didWrite("some.prefixable.lib.dart", EXTENSION_DEPS, provider);
-    didWrite("some.prefixable.lib.dart", EXTENSION_API, provider);
+    didWrite("my.prefixed.app.dart", EXTENSION_JS);
+    didWrite("my.prefixed.app.dart", EXTENSION_APP_JS);
+    didWrite("my.prefixed.app.dart", EXTENSION_DEPS);
+    didWrite("some.prefixable.lib.dart", EXTENSION_JS);
+    didWrite("some.prefixable.lib.dart", EXTENSION_DEPS);
   }
 
   private void compile() {
@@ -147,13 +144,8 @@ public class IncrementalCompilationWithPrefixTest extends CompilerTestCase {
     }
   }
 
-  private void didWrite(String sourceName, String extension, IncMockArtifactProvider provider) {
+  private void didWrite(String sourceName, String extension) {
     String spec = sourceName + "/" + extension;
     assertTrue("Expected write: " + spec, provider.writes.contains(spec));
   }
-
-  private void didNotWrite(String sourceName, String extension, IncMockArtifactProvider provider) {
-    String spec = sourceName + "/" + extension;
-    assertFalse("Didn't expect write: " + spec, provider.writes.contains(spec));
-  }
 }
diff --git a/compiler/javatests/com/google/dart/compiler/end2end/inc/MemoryLibrarySource.java b/compiler/javatests/com/google/dart/compiler/end2end/inc/MemoryLibrarySource.java
new file mode 100644
index 00000000000..e0469f23fb1
--- /dev/null
+++ b/compiler/javatests/com/google/dart/compiler/end2end/inc/MemoryLibrarySource.java
@@ -0,0 +1,108 @@
+// Copyright (c) 2011, 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.
+package com.google.dart.compiler.end2end.inc;
+
+import com.google.common.collect.Maps;
+import com.google.dart.compiler.DartSource;
+import com.google.dart.compiler.LibrarySource;
+import com.google.dart.compiler.Source;
+import com.google.dart.compiler.UrlDartSource;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.io.StringReader;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.Date;
+import java.util.Map;
+
+/**
+ * {@link LibrarySource} which provides content for all {@link Source}s from memory.
+ */
+public class MemoryLibrarySource implements LibrarySource {
+  private final String libName;
+  private final String libContent;
+  private final Map<String, String> sourceContentMap = Maps.newHashMap();
+  private final Map<String, Long> sourceLastModifiedMap = Maps.newHashMap();
+
+  public MemoryLibrarySource(String libName, String libContent) throws URISyntaxException {
+    this.libName = libName;
+    this.libContent = libContent;
+  }
+
+  @Override
+  public boolean exists() {
+    return true;
+  }
+
+  @Override
+  public String getName() {
+    return libName;
+  }
+
+  @Override
+  public URI getUri() {
+    return URI.create(libName);
+  }
+  
+  @Override
+  public long getLastModified() {
+    return 0;
+  }
+  
+  @Override
+  public Reader getSourceReader() throws IOException {
+    return new StringReader(libContent);
+  }
+
+  @Override
+  public LibrarySource getImportFor(String relPath) throws IOException {
+    // Not implemented for now, tests which use it don't work with imports.
+    return null;
+  }
+
+  @Override
+  public DartSource getSourceFor(final String relPath) {
+    final String content;
+    final Long sourceLastModified;
+    if (sourceContentMap.containsKey(relPath)) {
+      content = sourceContentMap.get(relPath);
+      sourceLastModified = sourceLastModifiedMap.get(relPath);
+    } else {
+      content = "";
+      sourceLastModified = Long.valueOf(0);
+    }
+    // Return fake UrlDateSource with in-memory content.
+    URI uri = URI.create(relPath);
+    return new UrlDartSource(uri, relPath, this) {
+      @Override
+      public String getName() {
+        return relPath;
+      }
+
+      @Override
+      public boolean exists() {
+        return true;
+      }
+
+      @Override
+      public long getLastModified() {
+        return sourceLastModified.longValue();
+      }
+
+      @Override
+      public Reader getSourceReader() throws IOException {
+        return new StringReader(content);
+      }
+    };
+  }
+
+  /**
+   * Sets the given content for the source.
+   */
+  public void setContent(String relPath, String content) {
+    sourceContentMap.put(relPath, content);
+    sourceLastModifiedMap.put(relPath, new Date().getTime());
+  }
+}
diff --git a/compiler/javatests/com/google/dart/compiler/end2end/inc/my.app.dart b/compiler/javatests/com/google/dart/compiler/end2end/inc/my.app.dart
index e02fbc69ba5..8a01c7486af 100644
--- a/compiler/javatests/com/google/dart/compiler/end2end/inc/my.app.dart
+++ b/compiler/javatests/com/google/dart/compiler/end2end/inc/my.app.dart
@@ -12,4 +12,4 @@
 #source("myother4.dart");
 #source("myother5.dart");
 #source("myother6.dart");
-#source("myother7.dart");
\ No newline at end of file
+#source("myother7.dart");
diff --git a/compiler/javatests/com/google/dart/compiler/parser/AbstractParserTest.java b/compiler/javatests/com/google/dart/compiler/parser/AbstractParserTest.java
index cb49d74204c..7bc8f840c1e 100644
--- a/compiler/javatests/com/google/dart/compiler/parser/AbstractParserTest.java
+++ b/compiler/javatests/com/google/dart/compiler/parser/AbstractParserTest.java
@@ -158,8 +158,8 @@ public abstract class AbstractParserTest extends CompilerTestCase {
 
   @Override
   protected DartParser makeParser(ParserContext context) {
-    Set<String> set = new HashSet<String>();
-    set.add("prefix");
-    return new DartParser(context, set);
+    Set<String> prefixes = new HashSet<String>();
+    prefixes.add("prefix");
+    return new DartParser(context, prefixes, false);
   }
 }
diff --git a/compiler/javatests/com/google/dart/compiler/parser/NegativeParserTest.java b/compiler/javatests/com/google/dart/compiler/parser/NegativeParserTest.java
index 1987e6ddea7..003235ee79e 100644
--- a/compiler/javatests/com/google/dart/compiler/parser/NegativeParserTest.java
+++ b/compiler/javatests/com/google/dart/compiler/parser/NegativeParserTest.java
@@ -12,6 +12,8 @@ import com.google.dart.compiler.ast.DartIdentifier;
 import com.google.dart.compiler.ast.DartMethodDefinition;
 import com.google.dart.compiler.ast.DartUnit;
 
+import java.util.Set;
+
 /**
  * Negative Parser/Syntax tests.
  */
@@ -541,4 +543,93 @@ public class NegativeParserTest extends CompilerTestCase {
             "}"),
         parserRunner.getDartUnit().toSource());
   }
+
+  /**
+   * Test for {@link DartUnit#getTopDeclarationNames()}.
+   */
+  public void test_getTopDeclarationNames() throws Exception {
+    DartParserRunner parserRunner =
+        parseSource(Joiner.on("\n").join(
+            "// filler filler filler filler filler filler filler filler filler filler",
+            "class MyClass {}",
+            "class MyInterface {}",
+            "topLevelMethod() {}",
+            "int get topLevelGetter() {return 0;}",
+            "void set topLevelSetter(int v) {}",
+            "typedef void MyTypeDef();",
+            ""));
+    DartUnit unit = parserRunner.getDartUnit();
+    // Check top level declarations.
+    Set<String> names = unit.getTopDeclarationNames();
+    assertEquals(6, names.size());
+    assertTrue(names.contains("MyClass"));
+    assertTrue(names.contains("MyInterface"));
+    assertTrue(names.contains("topLevelMethod"));
+    assertTrue(names.contains("topLevelGetter"));
+    assertTrue(names.contains("topLevelSetter"));
+    assertTrue(names.contains("MyTypeDef"));
+  }
+
+  /**
+   * Test for {@link DartUnit#getDeclarationNames()}.
+   */
+  public void test_getDeclarationNames() throws Exception {
+    DartParserRunner parserRunner =
+        parseSource(Joiner.on("\n").join(
+            "// filler filler filler filler filler filler filler filler filler filler",
+            "class MyClass<TypeVar> {",
+            "  myMethod(int pA, int pB) {",
+            "    int varA;",
+            "    try {",
+            "    } catch(var ex) {",
+            "    }",
+            "  }",
+            "}",
+            "topLevelMethod() {}",
+            "int get topLevelGetter() {return 0;}",
+            "void set topLevelSetter(int setterParam) {}",
+            "typedef void MyTypeDef();",
+            ""));
+    DartUnit unit = parserRunner.getDartUnit();
+    // Check all declarations.
+    Set<String> names = unit.getDeclarationNames();
+    assertEquals(12, names.size());
+    assertTrue(names.contains("MyClass"));
+    assertTrue(names.contains("TypeVar"));
+    assertTrue(names.contains("myMethod"));
+    assertTrue(names.contains("pA"));
+    assertTrue(names.contains("pB"));
+    assertTrue(names.contains("varA"));
+    assertTrue(names.contains("ex"));
+    assertTrue(names.contains("topLevelMethod"));
+    assertTrue(names.contains("topLevelGetter"));
+    assertTrue(names.contains("topLevelSetter"));
+    assertTrue(names.contains("setterParam"));
+    assertTrue(names.contains("MyTypeDef"));
+  }
+
+  /**
+   * There was bug in diet parser, it did not understand new "arrow" syntax of function definition.
+   */
+  public void test_dietParser_functionArrow() {
+    DartParserRunner parserRunner =
+        DartParserRunner.parse(
+            getName(),
+            Joiner.on("\n").join(
+                "class ClassWithVeryLongNameEnoughToForceLineWrapping {",
+                "  foo() => return 0;",
+                "}",
+                ""),
+            true);
+    assertErrors(parserRunner.getErrors());
+    assertEquals(
+        Joiner.on("\n").join(
+            "// unit " + getName(),
+            "class ClassWithVeryLongNameEnoughToForceLineWrapping {",
+            "",
+            "  foo() {",
+            "  }",
+            "}"),
+        parserRunner.getDartUnit().toSource().trim());
+  }
 }
diff --git a/compiler/javatests/com/google/dart/compiler/resolver/NegativeResolverTest.java b/compiler/javatests/com/google/dart/compiler/resolver/NegativeResolverTest.java
index 82993a7f864..eac32375f49 100644
--- a/compiler/javatests/com/google/dart/compiler/resolver/NegativeResolverTest.java
+++ b/compiler/javatests/com/google/dart/compiler/resolver/NegativeResolverTest.java
@@ -314,6 +314,16 @@ public class NegativeResolverTest extends CompilerTestCase {
     checkNumErrors("ConstVariableInitializationNegativeTest2.dart", 1);
   }
 
+  public void test_nameShadow_topLevel_method_class() {
+    checkSourceErrors(
+        makeCode(
+            "// filler filler filler filler filler filler filler filler filler filler",
+            "foo() {}",
+            "class foo {}"),
+        errEx(ResolverErrorCode.DUPLICATE_TOP_LEVEL_DEFINITION, 2, 1, 3),
+        errEx(ResolverErrorCode.DUPLICATE_TOP_LEVEL_DEFINITION, 3, 7, 3));
+  }
+
   public void test_nameShadow_topLevel_getterSetter_class() {
     checkSourceErrors(
         makeCode(
diff --git a/compiler/javatests/com/google/dart/compiler/type/TypeAnalyzerCompilerTest.java b/compiler/javatests/com/google/dart/compiler/type/TypeAnalyzerCompilerTest.java
index 11e487a90a3..cc0992d9c17 100644
--- a/compiler/javatests/com/google/dart/compiler/type/TypeAnalyzerCompilerTest.java
+++ b/compiler/javatests/com/google/dart/compiler/type/TypeAnalyzerCompilerTest.java
@@ -11,6 +11,7 @@ import com.google.common.collect.Iterables;
 import com.google.dart.compiler.CompilerTestCase;
 import com.google.dart.compiler.DartCompilationError;
 import com.google.dart.compiler.ast.DartClass;
+import com.google.dart.compiler.ast.DartExprStmt;
 import com.google.dart.compiler.ast.DartExpression;
 import com.google.dart.compiler.ast.DartField;
 import com.google.dart.compiler.ast.DartFieldDefinition;
@@ -23,6 +24,8 @@ import com.google.dart.compiler.ast.DartNode;
 import com.google.dart.compiler.ast.DartNodeTraverser;
 import com.google.dart.compiler.ast.DartParameter;
 import com.google.dart.compiler.ast.DartUnit;
+import com.google.dart.compiler.ast.DartUnqualifiedInvocation;
+import com.google.dart.compiler.common.Symbol;
 import com.google.dart.compiler.parser.ParserErrorCode;
 import com.google.dart.compiler.resolver.ClassElement;
 import com.google.dart.compiler.resolver.Element;
@@ -728,4 +731,35 @@ public class TypeAnalyzerCompilerTest extends CompilerTestCase {
                 "}"));
     assertErrors(libraryResult.getTypeErrors());
   }
+
+  public void test_bindToLibraryFunctionFirst() throws Exception {
+    AnalyzeLibraryResult libraryResult =
+        analyzeLibrary(
+            getName(),
+            makeCode(
+                "// filler filler filler filler filler filler filler filler filler filler",
+                "foo() {}",
+                "class A {",
+                " foo() {}",
+                "}",
+                "class B extends A {",
+                "  bar() {",
+                "    foo();",
+                "  }",
+                "}",
+                ""));
+    DartUnit unit = libraryResult.getLibraryUnitResult().getUnit(getName());
+    // Find foo() invocation.
+    DartUnqualifiedInvocation invocation;
+    {
+      DartClass classB = (DartClass) unit.getTopLevelNodes().get(2);
+      DartMethodDefinition methodBar = (DartMethodDefinition) classB.getMembers().get(0);
+      DartExprStmt stmt = (DartExprStmt) methodBar.getFunction().getBody().getStatements().get(0);
+      invocation = (DartUnqualifiedInvocation) stmt.getExpression();
+    }
+    // Check that unqualified foo() invocation is resolved to the top-level (library) function. 
+    Symbol symbol = invocation.getTarget().getSymbol();
+    assertNotNull(symbol);
+    assertSame(unit, symbol.getNode().getParent());
+  }
 }