Move nested classes of AstGraphBuilder into cc file.

src/compiler/ast-graph-builder.cc

Index: src/compiler/ast-graph-builder.cc
diff --git a/src/compiler/ast-graph-builder.cc b/src/compiler/ast-graph-builder.cc
index 3a9fcd9d83447d60e13359652f62fdbf40228f4c..87b0b2ddab3337879e2772be12a6605872b76168 100644
--- a/src/compiler/ast-graph-builder.cc
+++ b/src/compiler/ast-graph-builder.cc
@@ -21,6 +21,115 @@ namespace internal {
 namespace compiler {
 
 
+// Each expression in the AST is evaluated in a specific context. This context
+// decides how the evaluation result is passed up the visitor.
+class AstGraphBuilder::AstContext BASE_EMBEDDED {
+ public:
+  bool IsEffect() const { return kind_ == Expression::kEffect; }
+  bool IsValue() const { return kind_ == Expression::kValue; }
+  bool IsTest() const { return kind_ == Expression::kTest; }
+
+  // Determines how to combine the frame state with the value
+  // that is about to be plugged into this AstContext.
+  OutputFrameStateCombine GetStateCombine() {
+    return IsEffect() ? OutputFrameStateCombine::Ignore()
+                      : OutputFrameStateCombine::Push();
+  }
+
+  // Plug a node into this expression context.  Call this function in tail
+  // position in the Visit functions for expressions.
+  virtual void ProduceValue(Node* value) = 0;
+
+  // Unplugs a node from this expression context.  Call this to retrieve the
+  // result of another Visit function that already plugged the context.
+  virtual Node* ConsumeValue() = 0;
+
+  // Shortcut for "context->ProduceValue(context->ConsumeValue())".
+  void ReplaceValue() { ProduceValue(ConsumeValue()); }
+
+ protected:
+  AstContext(AstGraphBuilder* owner, Expression::Context kind);
+  virtual ~AstContext();
+
+  AstGraphBuilder* owner() const { return owner_; }
+  Environment* environment() const { return owner_->environment(); }
+
+// We want to be able to assert, in a context-specific way, that the stack
+// height makes sense when the context is filled.
+#ifdef DEBUG
+  int original_height_;
+#endif
+
+ private:
+  Expression::Context kind_;
+  AstGraphBuilder* owner_;
+  AstContext* outer_;
+};
+
+
+// Context to evaluate expression for its side effects only.
+class AstGraphBuilder::AstEffectContext FINAL : public AstContext {
+ public:
+  explicit AstEffectContext(AstGraphBuilder* owner)
+      : AstContext(owner, Expression::kEffect) {}
+  ~AstEffectContext() FINAL;
+  void ProduceValue(Node* value) FINAL;
+  Node* ConsumeValue() FINAL;
+};
+
+
+// Context to evaluate expression for its value (and side effects).
+class AstGraphBuilder::AstValueContext FINAL : public AstContext {
+ public:
+  explicit AstValueContext(AstGraphBuilder* owner)
+      : AstContext(owner, Expression::kValue) {}
+  ~AstValueContext() FINAL;
+  void ProduceValue(Node* value) FINAL;
+  Node* ConsumeValue() FINAL;
+};
+
+
+// Context to evaluate expression for a condition value (and side effects).
+class AstGraphBuilder::AstTestContext FINAL : public AstContext {
+ public:
+  explicit AstTestContext(AstGraphBuilder* owner)
+      : AstContext(owner, Expression::kTest) {}
+  ~AstTestContext() FINAL;
+  void ProduceValue(Node* value) FINAL;
+  Node* ConsumeValue() FINAL;
+};
+
+
+// Scoped class tracking context objects created by the visitor. Represents
+// mutations of the context chain within the function body and allows to
+// change the current {scope} and {context} during visitation.
+class AstGraphBuilder::ContextScope BASE_EMBEDDED {
+ public:
+  ContextScope(AstGraphBuilder* owner, Scope* scope, Node* context)
+      : owner_(owner),
+        next_(owner->execution_context()),
+        outer_(owner->current_context()),
+        scope_(scope) {
+    owner_->set_execution_context(this);  // Push.
+    owner_->set_current_context(context);
+  }
+
+  ~ContextScope() {
+    owner_->set_execution_context(next_);  // Pop.
+    owner_->set_current_context(outer_);
+  }
+
+  // Current scope during visitation.
+  Scope* scope() const { return scope_; }
+
+ private:
+  AstGraphBuilder* owner_;
+  ContextScope* next_;
+  Node* outer_;
+  Scope* scope_;
+};
+
+
 // Scoped class tracking control statements entered by the visitor. There are
 // different types of statements participating in this stack to properly track
 // local as well as non-local control flow:
@@ -541,6 +650,11 @@ Node* AstGraphBuilder::AstTestContext::ConsumeValue() {
 }
 
 
+Scope* AstGraphBuilder::current_scope() const {
+  return execution_context_->scope();
+}
+
+
 void AstGraphBuilder::ControlScope::PerformCommand(Command command,
                                                    Statement* target,
                                                    Node* value) {