Add statement hooks to TypeInferenceListener.

pkg/front_end/lib/src/fasta/kernel/kernel_shadow_ast.dart

 // Copyright (c) 2017, 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.
 
 /// This file declares a "shadow hierarchy" of concrete classes which extend
 /// the kernel class hierarchy, adding methods and fields needed by the
 /// BodyBuilder.
 ///
 /// Instances of these classes may be created using the factory methods in
 /// `ast_factory.dart`.
@@ skipping 72 matching lines @@
     return typeNeeded ? const DynamicType() : null;
   }
 }
 
 /// Concrete shadow object representing a statement block in kernel form.
 class KernelBlock extends Block implements KernelStatement {
   KernelBlock(List<Statement> statements) : super(statements);
 
   @override
   void _inferStatement(KernelTypeInferrer inferrer) {
+    inferrer.listener.blockEnter(this);
     for (var statement in statements) {
       inferrer.inferStatement(statement);
     }
+    inferrer.listener.blockExit(this);
   }
 }
 
 /// Concrete shadow object representing a boolean literal in kernel form.
 class KernelBoolLiteral extends BoolLiteral implements KernelExpression {
   KernelBoolLiteral(bool value) : super(value);
 
   @override
   DartType _inferExpression(
       KernelTypeInferrer inferrer, DartType typeContext, bool typeNeeded) {
@@ skipping 146 matching lines @@
       KernelTypeInferrer inferrer, DartType typeContext, bool typeNeeded);
 }
 
 /// Concrete shadow object representing an expression statement in kernel form.
 class KernelExpressionStatement extends ExpressionStatement
     implements KernelStatement {
   KernelExpressionStatement(Expression expression) : super(expression);
 
   @override
   void _inferStatement(KernelTypeInferrer inferrer) {
+    inferrer.listener.expressionStatementEnter(this);
     inferrer.inferExpression(expression, null, false);
+    inferrer.listener.expressionStatementExit(this);
   }
 }
 
 /// Concrete shadow object representing a field in kernel form.
 class KernelField extends Field {
   bool _implicitlyTyped = true;
 
   FieldNode _fieldNode;
 
   bool _isInferred = false;
@@ skipping 24 matching lines @@
 
 /// Concrete shadow object representing a local function declaration in kernel
 /// form.
 class KernelFunctionDeclaration extends FunctionDeclaration
     implements KernelStatement {
   KernelFunctionDeclaration(VariableDeclaration variable, FunctionNode function)
       : super(variable, function);
 
   @override
   void _inferStatement(KernelTypeInferrer inferrer) {
+    inferrer.listener.functionDeclarationEnter(this);
     var oldClosureContext = inferrer.closureContext;
     inferrer.closureContext = null;
     inferrer.inferStatement(function.body);
     inferrer.closureContext = oldClosureContext;
+    inferrer.listener.functionDeclarationExit(this);
   }
 }
 
 /// Concrete shadow object representing a function expression in kernel form.
 class KernelFunctionExpression extends FunctionExpression
     implements KernelExpression {
   KernelFunctionExpression(FunctionNode function) : super(function);
 
   @override
   DartType _inferExpression(
@@ skipping 161 matching lines @@
   }
 }
 
 /// Concrete shadow object representing an if statement in kernel form.
 class KernelIfStatement extends IfStatement implements KernelStatement {
   KernelIfStatement(Expression condition, Statement then, Statement otherwise)
       : super(condition, then, otherwise);
 
   @override
   void _inferStatement(KernelTypeInferrer inferrer) {
+    inferrer.listener.ifStatementEnter(this);
     inferrer.inferExpression(
         condition, inferrer.coreTypes.boolClass.rawType, false);
     inferrer.inferStatement(then);
     if (otherwise != null) inferrer.inferStatement(otherwise);
+    inferrer.listener.ifStatementExit(this);
   }
 }
 
 /// Concrete shadow object representing an integer literal in kernel form.
 class KernelIntLiteral extends IntLiteral implements KernelExpression {
   KernelIntLiteral(int value) : super(value);
 
   @override
   DartType _inferExpression(
       KernelTypeInferrer inferrer, DartType typeContext, bool typeNeeded) {
@@ skipping 249 matching lines @@
     return typeNeeded ? const DynamicType() : null;
   }
 }
 
 /// Concrete shadow object representing a return statement in kernel form.
 class KernelReturnStatement extends ReturnStatement implements KernelStatement {
   KernelReturnStatement([Expression expression]) : super(expression);
 
   @override
   void _inferStatement(KernelTypeInferrer inferrer) {
+    inferrer.listener.returnStatementEnter(this);
     var closureContext = inferrer.closureContext;
     var typeContext = closureContext != null && !closureContext.isGenerator
         ? closureContext.returnContext
         : null;
     var inferredType = expression != null
         ? inferrer.inferExpression(
             expression, typeContext, closureContext != null)
         : const VoidType();
-    if (expression == null) {
-      // Analyzer treats bare `return` statements as having no effect on the
-      // inferred type of the closure.  TODO(paulberry): is this what we want
-      // for Fasta?
-      return;
+    // Analyzer treats bare `return` statements as having no effect on the
+    // inferred type of the closure.  TODO(paulberry): is this what we want
+    // for Fasta?
+    if (expression != null) {
+      closureContext?.updateInferredReturnType(inferrer, inferredType);
     }
-    closureContext?.updateInferredReturnType(inferrer, inferredType);
+    inferrer.listener.returnStatementExit(this);
   }
 }
 
 /// Common base class for shadow objects representing statements in kernel
 /// form.
 abstract class KernelStatement extends Statement {
   /// Calls back to [inferrer] to perform type inference for whatever concrete
   /// type of [KernelStatement] this is.
   void _inferStatement(KernelTypeInferrer inferrer);
 }
@@ skipping 432 matching lines @@
         super(name,
             initializer: initializer,
             type: type ?? const DynamicType(),
             isFinal: isFinal,
             isConst: isConst);
 
   DartType get _declaredType => _implicitlyTyped ? null : type;
 
   @override
   void _inferStatement(KernelTypeInferrer inferrer) {
+    inferrer.listener.variableDeclarationEnter(this);
     var declaredType = _implicitlyTyped ? null : type;
-    if (initializer == null) return;
-    var inferredType = inferrer.inferDeclarationType(
-        inferrer.inferExpression(initializer, declaredType, _implicitlyTyped));
-    if (inferrer.strongMode && _implicitlyTyped) {
-      inferrer.instrumentation?.record(Uri.parse(inferrer.uri), fileOffset,
-          'type', new InstrumentationValueForType(inferredType));
-      type = inferredType;
+    if (initializer != null) {
+      var inferredType = inferrer.inferDeclarationType(inferrer.inferExpression(
+          initializer, declaredType, _implicitlyTyped));
+      if (inferrer.strongMode && _implicitlyTyped) {
+        inferrer.instrumentation?.record(Uri.parse(inferrer.uri), fileOffset,
+            'type', new InstrumentationValueForType(inferredType));
+        type = inferredType;
+      }
     }
+    inferrer.listener.variableDeclarationExit(this);
   }
 
   /// Determine whether the given [KernelVariableDeclaration] had an implicit
   /// type.
   ///
   /// This is static to avoid introducing a method that would be visible to
   /// the kernel.
   static bool isImplicitlyTyped(KernelVariableDeclaration variable) =>
       variable._implicitlyTyped;
 }
@@ skipping 39 matching lines @@
       KernelTypeInferrer inferrer, DartType typeContext, bool typeNeeded) {
     var variable = this.variable as KernelVariableDeclaration;
     typeNeeded =
         inferrer.listener.variableSetEnter(this, typeContext) || typeNeeded;
     var inferredType =
         inferrer.inferExpression(value, variable._declaredType, typeNeeded);
     inferrer.listener.variableSetExit(this, inferredType);
     return inferredType;
   }
 }