[kernel] Move procedure lazy loading to function node body

Previously lazy loading was done in Procedure by lazy loading functionNode,
now lazy loading is done (only through Procedure) in the functionNode by
lazy loading the body.

Bug:
Change-Id: I25cc86d038123ed4992162b65aa95781ea2c56e8
Reviewed-on: https://dart-review.googlesource.com/15560
Commit-Queue: Jens Johansen <[email protected]>
Reviewed-by: Peter von der Ahé <[email protected]>

Author: jensjoha

pkg/front_end/lib/src/base/processed_options.dart

@@ -295,7 +295,7 @@ class ProcessedOptions {
     Program program = new Program(nameRoot: nameRoot);
     // TODO(ahe): Pass file name to BinaryBuilder.
     // TODO(ahe): Control lazy loading via an option.
-    new BinaryBuilder(bytes, null, true).readProgram(program);
+    new BinaryBuilder(bytes, null, false).readProgram(program);
     return program;
   }
 

pkg/kernel/lib/ast.dart

@@ -1282,42 +1282,12 @@ class Procedure extends Member {
   int flags = 0;
   // function is null if and only if abstract, external,
   // or builder (below) is set.
-  FunctionNode _function;
-
-  void Function() lazyBuilder;
-
-  void _buildLazy() {
-    if (lazyBuilder != null) {
-      var lazyBuilderLocal = lazyBuilder;
-      lazyBuilder = null;
-      lazyBuilderLocal();
-    }
-  }
-
-  void set transformerFlags(int flags) {
-    _buildLazy();
-    super.transformerFlags = flags;
-  }
-
-  int get transformerFlags {
-    _buildLazy();
-    return super.transformerFlags;
-  }
-
-  void set function(FunctionNode function) {
-    _buildLazy();
-    _function = function;
-  }
-
-  FunctionNode get function {
-    _buildLazy();
-    return _function;
-  }
+  FunctionNode function;
 
   /// The uri of the source file this procedure was loaded from.
   String fileUri;
 
-  Procedure(Name name, this.kind, this._function,
+  Procedure(Name name, this.kind, this.function,
       {bool isAbstract: false,
       bool isStatic: false,
       bool isExternal: false,
@@ -1647,9 +1617,29 @@ class FunctionNode extends TreeNode {
   @nocoq
   List<VariableDeclaration> namedParameters;
   DartType returnType; // Not null.
-  Statement body;
+  Statement _body;
+
+  void Function() lazyBuilder;
+
+  void _buildLazy() {
+    if (lazyBuilder != null) {
+      var lazyBuilderLocal = lazyBuilder;
+      lazyBuilder = null;
+      lazyBuilderLocal();
+    }
+  }
+
+  Statement get body {
+    _buildLazy();
+    return _body;
+  }
 
-  FunctionNode(this.body,
+  void set body(Statement body) {
+    _buildLazy();
+    _body = body;
+  }
+
+  FunctionNode(this._body,
       {List<TypeParameter> typeParameters,
       List<VariableDeclaration> positionalParameters,
       List<VariableDeclaration> namedParameters,
@@ -1667,7 +1657,7 @@ class FunctionNode extends TreeNode {
     setParents(this.typeParameters, this);
     setParents(this.positionalParameters, this);
     setParents(this.namedParameters, this);
-    body?.parent = this;
+    _body?.parent = this;
     dartAsyncMarker ??= asyncMarker;
   }
 

pkg/kernel/lib/binary/ast_from_binary.dart

@@ -782,7 +782,7 @@ class BinaryBuilder {
     var name = readName();
     var annotations = readAnnotationList(node);
     debugPath.add(node.name?.name ?? 'constructor');
-    var function = readFunctionNode();
+    var function = readFunctionNode(false);
     pushVariableDeclarations(function.positionalParameters);
     pushVariableDeclarations(function.namedParameters);
     if (shouldWriteData) {
@@ -829,12 +829,8 @@ class BinaryBuilder {
     bool readFunctionNodeNow =
         (kind == ProcedureKind.Factory && functionNodeSize <= 50) ||
             _disableLazyReading;
-    var function;
-    var transformerFlags;
-    if (readFunctionNodeNow) {
-      function = readFunctionNodeOption();
-      transformerFlags = getAndResetTransformerFlags();
-    }
+    var function = readFunctionNodeOption(!readFunctionNodeNow);
+    var transformerFlags = getAndResetTransformerFlags();
     debugPath.removeLast();
     if (shouldWriteData) {
       node.fileOffset = fileOffset;
@@ -844,25 +840,9 @@ class BinaryBuilder {
       node.name = name;
       node.fileUri = fileUri;
       node.annotations = annotations;
-      if (readFunctionNodeNow) {
-        node.function = function;
-        function?.parent = node;
-        node.transformerFlags = transformerFlags;
-      } else {
-        int offset = _byteOffset;
-        int programStartOffset = _programStartOffset;
-        List<TypeParameter> typeParameters = typeParameterStack.toList();
-        node.lazyBuilder = () {
-          _byteOffset = offset;
-          typeParameterStack.clear();
-          typeParameterStack.addAll(typeParameters);
-          _programStartOffset = programStartOffset;
-          FunctionNode functionNode = readFunctionNodeOption();
-          node.function = functionNode;
-          functionNode?.parent = node;
-          node.transformerFlags = getAndResetTransformerFlags();
-        };
-      }
+      node.function = function;
+      function?.parent = node;
+      node.transformerFlags = transformerFlags;
     }
     _byteOffset = endOffset;
     return node;
@@ -894,11 +874,11 @@ class BinaryBuilder {
     }
   }
 
-  FunctionNode readFunctionNodeOption() {
-    return readAndCheckOptionTag() ? readFunctionNode() : null;
+  FunctionNode readFunctionNodeOption(bool lazyLoadBody) {
+    return readAndCheckOptionTag() ? readFunctionNode(lazyLoadBody) : null;
   }
 
-  FunctionNode readFunctionNode() {
+  FunctionNode readFunctionNode(bool lazyLoadBody) {
     int tag = readByte();
     assert(tag == Tag.FunctionNode);
     int offset = readOffset();
@@ -914,12 +894,14 @@ class BinaryBuilder {
     var named = readAndPushVariableDeclarationList();
     var returnType = readDartType();
     int oldLabelStackBase = labelStackBase;
-    labelStackBase = labelStack.length;
-    var body = readStatementOption();
-    labelStackBase = oldLabelStackBase;
-    variableStack.length = variableStackHeight;
-    typeParameterStack.length = typeParameterStackHeight;
-    return new FunctionNode(body,
+
+    var body;
+    if (!lazyLoadBody) {
+      labelStackBase = labelStack.length;
+      body = readStatementOption();
+    }
+
+    FunctionNode result = new FunctionNode(body,
         typeParameters: typeParameters,
         requiredParameterCount: requiredParameterCount,
         positionalParameters: positional,
@@ -929,6 +911,37 @@ class BinaryBuilder {
         dartAsyncMarker: dartAsyncMarker)
       ..fileOffset = offset
       ..fileEndOffset = endOffset;
+
+    if (lazyLoadBody) {
+      final int savedByteOffset = _byteOffset;
+      final int programStartOffset = _programStartOffset;
+      final List<TypeParameter> typeParameters = typeParameterStack.toList();
+      final List<VariableDeclaration> variables = variableStack.toList();
+      result.lazyBuilder = () {
+        _byteOffset = savedByteOffset;
+        typeParameterStack.clear();
+        typeParameterStack.addAll(typeParameters);
+        variableStack.clear();
+        variableStack.addAll(variables);
+        _programStartOffset = programStartOffset;
+
+        result.body = readStatementOption();
+        result.body?.parent = result;
+        labelStackBase = oldLabelStackBase;
+        variableStack.length = variableStackHeight;
+        typeParameterStack.length = typeParameterStackHeight;
+        if (result.parent is Procedure) {
+          Procedure parent = result.parent;
+          parent.transformerFlags |= getAndResetTransformerFlags();
+        }
+      };
+    }
+
+    labelStackBase = oldLabelStackBase;
+    variableStack.length = variableStackHeight;
+    typeParameterStack.length = typeParameterStackHeight;
+
+    return result;
   }
 
   void pushVariableDeclaration(VariableDeclaration variable) {
@@ -1165,7 +1178,8 @@ class BinaryBuilder {
         return new AwaitExpression(readExpression());
       case Tag.FunctionExpression:
         int offset = readOffset();
-        return new FunctionExpression(readFunctionNode())..fileOffset = offset;
+        return new FunctionExpression(readFunctionNode(false))
+          ..fileOffset = offset;
       case Tag.Let:
         var variable = readVariableDeclaration();
         int stackHeight = variableStack.length;
@@ -1329,7 +1343,7 @@ class BinaryBuilder {
         int offset = readOffset();
         var variable = readVariableDeclaration();
         variableStack.add(variable); // Will be popped by the enclosing scope.
-        var function = readFunctionNode();
+        var function = readFunctionNode(false);
         return new FunctionDeclaration(variable, function)..fileOffset = offset;
       default:
         throw fail('Invalid statement tag: $tag');
@@ -1737,9 +1751,9 @@ class BinaryBuilderWithMetadata extends BinaryBuilder implements BinarySource {
   }
 
   @override
-  FunctionNode readFunctionNode() {
+  FunctionNode readFunctionNode(bool lazyLoadBody) {
     final nodeOffset = _byteOffset;
-    final result = super.readFunctionNode();
+    final result = super.readFunctionNode(lazyLoadBody);
     return _associateMetadata(result, nodeOffset);
   }