Prototype re-compiling methods in dart2js

lib/compiler/implementation/compiler.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 
 /**
  * If true, print a warning for each method that was resolved, but not
  * compiled.
  */
 final bool REPORT_EXCESS_RESOLUTION = false;
 
+/**
+ * If true, trace information on pass2 optimizations.
+ */
+final bool REPORT_PASS2_OPTIMIZATIONS = false;
+
 class WorkItem {
   final Element element;
   TreeElements resolutionTree;
   bool allowSpeculativeOptimization = true;
   List<HTypeGuard> guards = const <HTypeGuard>[];
 
   WorkItem(this.element, this.resolutionTree);
 
   bool isAnalyzed() => resolutionTree !== null;
 
@@ skipping 135 matching lines @@
   ScannerTask scanner;
   DietParserTask dietParser;
   ParserTask parser;
   TreeValidatorTask validator;
   UnparseValidator unparseValidator;
   ResolverTask resolver;
   TypeCheckerTask checker;
   Backend backend;
   ConstantHandler constantHandler;
   EnqueueTask enqueuer;
+  int pass = 1;

[ngeoffray, 2012/06/14 12:42:24]

This field name is a little too generic for my taste. Maybe a boolean named
isRecompiling?

[Søren Gjesse, 2012/06/15 09:25:02]

Changed it to phase and added constants for each phase.

 
   static final SourceString MAIN = const SourceString('main');
   static final SourceString NO_SUCH_METHOD = const SourceString('noSuchMethod');
   static final SourceString NO_SUCH_METHOD_EXCEPTION =
       const SourceString('NoSuchMethodException');
   static final SourceString START_ROOT_ISOLATE =
       const SourceString('startRootIsolate');
   bool enabledNoSuchMethod = false;
 
   Stopwatch codegenProgress;
@@ skipping 16 matching lines @@
     resolver = new ResolverTask(this);
     checker = new TypeCheckerTask(this);
     backend = emitJavascript ?
         new JavaScriptBackend(this) : new dart_backend.DartBackend(this);
     enqueuer = new EnqueueTask(this);
     tasks = [scanner, dietParser, parser, resolver, checker,
              unparseValidator, constantHandler, enqueuer];
     tasks.addAll(backend.tasks);
   }
 
+  Universe get resolverWorld() => enqueuer.resolution.universe;
   Universe get codegenWorld() => enqueuer.codegen.universe;
 
   int getNextFreeClassId() => nextFreeClassId++;
 
   void ensure(bool condition) {
     if (!condition) cancel('failed assertion in leg');
   }
 
   void unimplemented(String methodName,
                      [Node node, Token token, HInstruction instruction,
@@ skipping 200 matching lines @@
     // should know this.
     world.populate(this, libraries.getValues());
 
     log('Resolving...');
     backend.enqueueHelpers(enqueuer.resolution);
     processQueue(enqueuer.resolution, main);
     log('Resolved ${enqueuer.resolution.resolvedElements.length} elements.');
 
     log('Compiling...');
     processQueue(enqueuer.codegen, main);
+    log("Recompiling ${enqueuer.codegen.recompilationCandidates.length} "
+        "methods...");
+    processRecompilationQueue(enqueuer.codegen);
     log('Compiled ${codegenWorld.generatedCode.length} methods.');
 
     backend.assembleProgram();
 
     checkQueues();
   }
 
   processQueue(Enqueuer world, Element main) {
     backend.processNativeClasses(world, libraries.getValues());
     world.addToWorkList(main);
     codegenProgress.reset();
     world.forEach((WorkItem work) {
       withCurrentElement(work.element, () => work.run(this, world));
     });
     world.queueIsClosed = true;
     assert(world.checkNoEnqueuedInvokedInstanceMethods());
     world.registerFieldClosureInvocations();
   }
 
+  processRecompilationQueue(Enqueuer world) {
+    pass = 2;
+    while (!world.recompilationCandidates.isEmpty()) {
+      WorkItem work = world.recompilationCandidates.next();
+      var oldCode = world.universe.generatedCode[work.element];
+      world.universe.generatedCode.remove(work.element);
+      withCurrentElement(work.element, () => work.run(this, world));
+      var newCode = world.universe.generatedCode[work.element];
+      if (REPORT_PASS2_OPTIMIZATIONS && newCode != oldCode) {
+        log("Pass 2 optimization:");
+        log("Before:\n$oldCode");
+        log("After:\n$newCode");
+      }
+    }
+  }
+
   /**
    * Perform various checks of the queues. This includes checking that
    * the queues are empty (nothing was added after we stopped
    * processing the quese). Also compute the number of methods that
    * were resolved, but not compiled (aka excess resolution).
    */
   checkQueues() {
     for (var world in [enqueuer.resolution, enqueuer.codegen]) {
       world.forEach((WorkItem work) {
         internalErrorOnElement(work.element, "Work list is not empty.");
@@ skipping 65 matching lines @@
     result = analyzeElement(element);
     enqueuer.resolution.resolvedElements[element] = result;
     return result;
   }
 
   String codegen(WorkItem work, Enqueuer world) {
     if (world !== enqueuer.codegen) return null;
     if (codegenProgress.elapsedInMs() > 500) {
       // TODO(ahe): Add structured diagnostics to the compiler API and
       // use it to separate this from the --verbose option.
       log('Compiled ${codegenWorld.generatedCode.length} methods.');

[ahe, 2012/06/14 13:23:54]

I think you may have broken this message. I think the count remains the same
when recompiling.

[Søren Gjesse, 2012/06/15 09:25:02]

Updated to report something more useful. Made the resolver report progress as
well.

       codegenProgress.reset();
     }
     if (work.element.kind.category == ElementCategory.VARIABLE) {
       constantHandler.compileWorkItem(work);
       return null;
     } else {
       String code = backend.codegen(work);
       codegenWorld.addGeneratedCode(work, code);
       return code;
     }
@@ skipping 38 matching lines @@
     if (message is TypeWarning) {
       // TODO(ahe): Don't supress these warning when the type checker
       // is more complete.
       if (message.message.kind === MessageKind.NOT_ASSIGNABLE) return;
       if (message.message.kind === MessageKind.MISSING_RETURN) return;
       if (message.message.kind === MessageKind.MAYBE_MISSING_RETURN) return;
       if (message.message.kind === MessageKind.ADDITIONAL_ARGUMENT) return;
       if (message.message.kind === MessageKind.METHOD_NOT_FOUND) return;
     }
     SourceSpan span = spanFromNode(node);
+
     reportDiagnostic(span, "${magenta('warning:')} $message", false);
   }
 
   reportError(Node node, var message) {
     SourceSpan span = spanFromNode(node);
     reportDiagnostic(span, "${red('error:')} $message", true);
     throw new CompilerCancelledException(message.toString());
   }
 
   abstract void reportDiagnostic(SourceSpan span, String message, bool fatal);
@@ skipping 115 matching lines @@
     // invariant that endOffset > beginOffset, but for EOF the
     // charoffset of the next token may be [beginOffset]. This can
     // also happen for synthetized tokens that are produced during
     // error handling.
     final endOffset =
       Math.max((end.next !== null) ? end.next.charOffset : 0, beginOffset + 1);
     assert(endOffset > beginOffset);
     return f(beginOffset, endOffset);
   }
 }