dart2js: Construct the entire output as a single AST before printing.

BUG=
R=floitsch@google.com, sra@google.com

Review URL: https://codereview.chromium.org//1140703006

pkg/compiler/lib/src/js_backend/constant_emitter.dart

@@ -296,11 +296,11 @@ class ConstantEmitter
         backend.classNeedsRti(type.element)) {
       InterfaceType interface = type;
       RuntimeTypes rti = backend.rti;
-      Iterable<String> arguments = interface.typeArguments
+      Iterable<jsAst.Expression> arguments = interface.typeArguments
           .map((DartType type) =>
-              rti.getTypeRepresentationWithHashes(type, (_){}));
+              rti.getTypeRepresentationWithPlaceholders(type, (_){}));
       jsAst.Expression argumentList =
-          new jsAst.LiteralString('[${arguments.join(', ')}]');
+          new jsAst.ArrayInitializer(arguments.toList());
       return new jsAst.Call(getHelperProperty(backend.getSetRuntimeTypeInfo()),
                             [value, argumentList]);
     }

pkg/compiler/lib/src/js_backend/runtime_types.dart

@@ -550,15 +550,16 @@ class RuntimeTypes {
     }
   }
 
-  String getTypeRepresentationWithHashes(DartType type,
-                                         OnVariableCallback onVariable) {
+  jsAst.Expression getTypeRepresentationWithPlaceholders(DartType type,
+      OnVariableCallback onVariable) {
     // Create a type representation.  For type variables call the original
     // callback for side effects and return a template placeholder.
+    int positions = 0;
     jsAst.Expression representation = getTypeRepresentation(type, (variable) {
       onVariable(variable);
-      return new jsAst.LiteralString('#');
+      return new jsAst.InterpolatedExpression(positions++);
     });
-    return jsAst.prettyPrint(representation, compiler).buffer.toString();
+    return representation;
   }
 
   jsAst.Expression getTypeRepresentation(

pkg/compiler/lib/src/js_emitter/old_emitter/interceptor_emitter.dart

@@ -13,35 +13,40 @@ class InterceptorEmitter extends CodeEmitterHelper {
     }
   }
 
-  void emitGetInterceptorMethod(CodeOutput output,
-                                String key,
-                                Set<ClassElement> classes) {
+  jsAst.Expression buildGetInterceptorMethod(String key,
+                                             Set<ClassElement> classes) {
     InterceptorStubGenerator stubGenerator =
         new InterceptorStubGenerator(compiler, namer, backend);
     jsAst.Expression function =
         stubGenerator.generateGetInterceptorMethod(classes);
 
-    output.addBuffer(jsAst.prettyPrint(
-        js('${namer.globalObjectFor(backend.interceptorsLibrary)}.# = #',
-           [key, function]),
-        compiler));
-    output.add(N);
+    return function;
   }
 
   /**
    * Emit all versions of the [:getInterceptor:] method.
    */
-  void emitGetInterceptorMethods(CodeOutput output) {
-    emitter.addComment('getInterceptor methods', output);
+  jsAst.Statement buildGetInterceptorMethods() {
+    List<jsAst.Statement> parts = <jsAst.Statement>[];
+
+    parts.add(js.comment('getInterceptor methods'));
+
     Map<String, Set<ClassElement>> specializedGetInterceptors =
         backend.specializedGetInterceptors;
     for (String name in specializedGetInterceptors.keys.toList()..sort()) {
       Set<ClassElement> classes = specializedGetInterceptors[name];
-      emitGetInterceptorMethod(output, name, classes);
+      parts.add(
+          js.statement('#.# = #',
+                       [namer.globalObjectFor(backend.interceptorsLibrary),
+                        name,
+                        buildGetInterceptorMethod(name, classes)]));
     }
+
+    return new jsAst.Block(parts);
   }
 
-  void emitOneShotInterceptors(CodeOutput output) {
+  jsAst.Statement buildOneShotInterceptors() {
+    List<jsAst.Statement> parts = <jsAst.Statement>[];
     List<String> names = backend.oneShotInterceptors.keys.toList();
     names.sort();
 
@@ -51,12 +56,10 @@ class InterceptorEmitter extends CodeEmitterHelper {
     for (String name in names) {
       jsAst.Expression function =
           stubGenerator.generateOneShotInterceptor(name);
-      jsAst.Expression assignment =
-          js('${globalObject}.# = #', [name, function]);
-
-      output.addBuffer(jsAst.prettyPrint(assignment, compiler));
-      output.add(N);
+      parts.add(js.statement('${globalObject}.# = #', [name, function]));
     }
+
+    return new jsAst.Block(parts);
   }
 
   /**
@@ -87,15 +90,12 @@ class InterceptorEmitter extends CodeEmitterHelper {
    * `findInterceptorForType`.  See declaration of `typeToInterceptor` in
    * `interceptors.dart`.
    */
-  void emitTypeToInterceptorMap(Program program, CodeOutput output) {
+  jsAst.Statement buildTypeToInterceptorMap(Program program) {
     jsAst.Expression array = program.typeToInterceptorMap;
-    if (array == null) return;
+    if (array == null) return js.comment("Empty type-to-interceptor map.");
 
     jsAst.Expression typeToInterceptorMap = emitter
         .generateEmbeddedGlobalAccess(embeddedNames.TYPE_TO_INTERCEPTOR_MAP);
-    jsAst.Expression assignment = js('# = #', [typeToInterceptorMap, array]);
-
-    output.addBuffer(jsAst.prettyPrint(assignment, compiler));
-    output.add(N);
+    return js.statement('# = #', [typeToInterceptorMap, array]);
   }
 }

pkg/compiler/lib/src/ssa/builder.dart

@@ -3559,17 +3559,17 @@ class SsaBuilder extends NewResolvedVisitor {
       InterfaceType interface = type;
       List<HInstruction> inputs = <HInstruction>[];
       bool first = true;
-      List<String> templates = <String>[];
+      List<js.Expression> templates = <js.Expression>[];
       for (DartType argument in interface.typeArguments) {
-        templates.add(rti.getTypeRepresentationWithHashes(argument, (variable) {
+        templates.add(rti.getTypeRepresentationWithPlaceholders(argument, (variable) {
           HInstruction runtimeType = addTypeVariableReference(variable);
           inputs.add(runtimeType);
         }));
       }
-      String template = '[${templates.join(', ')}]';
       // TODO(sra): This is a fresh template each time.  We can't let the
       // template manager build them.
-      js.Template code = js.js.uncachedExpressionTemplate(template);
+      js.Template code = new js.Template(null,
+                                         new js.ArrayInitializer(templates));
       HInstruction representation =
           new HForeignCode(code, backend.readableArrayType, inputs,
               nativeBehavior: native.NativeBehavior.PURE_ALLOCATION);
@@ -4618,11 +4618,12 @@ class SsaBuilder extends NewResolvedVisitor {
 
     List<HInstruction> inputs = <HInstruction>[];
 
-    String template = rti.getTypeRepresentationWithHashes(argument, (variable) {
-      inputs.add(addTypeVariableReference(variable));
-    });
+    js.Expression template =
+        rti.getTypeRepresentationWithPlaceholders(argument, (variable) {
+            inputs.add(addTypeVariableReference(variable));
+        });
 
-    js.Template code = js.js.uncachedExpressionTemplate(template);
+    js.Template code = new js.Template(null, template);
     HInstruction result = new HForeignCode(code, backend.stringType, inputs,
         nativeBehavior: native.NativeBehavior.PURE);
     add(result);

pkg/dart2js_incremental/lib/caching_compiler.dart

@@ -130,7 +130,6 @@ Future<Compiler> reuseCompiler(
 
     backend.emitter.oldEmitter
         ..outputBuffers.clear()
-        ..isolateProperties = null
         ..classesCollector = null
         ..mangledFieldNames.clear()
         ..mangledGlobalFieldNames.clear()

pkg/js_ast/lib/src/builder.dart

@@ -329,8 +329,6 @@ class JsBuilder {
   /// [escapedString].
   LiteralString string(String value) => new LiteralString('"$value"');
 
-  LiteralString name(String name) => new LiteralString(name);
-
   LiteralNumber number(num value) => new LiteralNumber('$value');
 
   LiteralBool boolean(bool value) => new LiteralBool(value);

pkg/js_ast/lib/src/printer.dart

@@ -1156,9 +1156,13 @@ class OrderedSet<T> {
 // separate pass because JS vars are lifted to the top of the function.
 class VarCollector extends BaseVisitor {
   bool nested;
+  bool enableRenaming = true;
   final OrderedSet<String> vars;
   final OrderedSet<String> params;
 
+  static final String disableVariableMinificationPattern = "::norenaming::";
+  static final String enableVariableMinificationPattern = "::dorenaming::";
+
   VarCollector() : nested = false,
                    vars = new OrderedSet<String>(),
                    params = new OrderedSet<String>();
@@ -1195,8 +1199,16 @@ class VarCollector extends BaseVisitor {
 
   void visitThis(This node) {}
 
+  void visitComment(Comment node) {
+    if (node.comment.contains(disableVariableMinificationPattern)) {
+      enableRenaming = false;
+    } else if (node.comment.contains(enableVariableMinificationPattern)) {
+      enableRenaming = true;
+    }
+  }
+
   void visitVariableDeclaration(VariableDeclaration decl) {
-    if (decl.allowRename) vars.add(decl.name);
+    if (enableRenaming && decl.allowRename) vars.add(decl.name);
   }
 }
 

pkg/js_ast/lib/src/template.dart

@@ -56,6 +56,7 @@ class Template {
 
   Template(this.source, this.ast,
            {this.isExpression: true, this.forceCopy: false}) {
+    assert(this.isExpression ? ast is Expression : ast is Statement);
     _compile();
   }