[Interpreter] Add switch support.

src/interpreter/control-flow-builders.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_INTERPRETER_CONTROL_FLOW_BUILDERS_H_
 #define V8_INTERPRETER_CONTROL_FLOW_BUILDERS_H_
 
 #include "src/interpreter/bytecode-array-builder.h"
 
 #include "src/zone-containers.h"
@@ skipping 10 matching lines @@
 
  protected:
   BytecodeArrayBuilder* builder() const { return builder_; }
 
  private:
   BytecodeArrayBuilder* builder_;
 
   DISALLOW_COPY_AND_ASSIGN(ControlFlowBuilder);
 };
 
+class BreakableControlFlowBuilder : public ControlFlowBuilder {
+ public:
+  explicit BreakableControlFlowBuilder(BytecodeArrayBuilder* builder)
+      : ControlFlowBuilder(builder),
+        break_sites_(builder->zone()) {}
+  virtual ~BreakableControlFlowBuilder();
+
+  // This method should be called by the control flow owner before
+  // destruction to update sites that emit jumps for break.
+  void SetBreakTarget(const BytecodeLabel& break_target);
+
+  // This method is called when visiting break statements in the AST.
+  // Inserts a jump to a unbound label that is patched when the corresponding
+  // SetBreakTarget is called.
+  void Break() { EmitJump(&break_sites_); }
+  void BreakIfTrue() { EmitJumpIfTrue(&break_sites_); }
+  void BreakIfUndefined() { EmitJumpIfUndefined(&break_sites_); }
+  void BreakIfNull() { EmitJumpIfNull(&break_sites_); }
+
+ protected:
+  void EmitJump(ZoneVector<BytecodeLabel>* labels);
+  void EmitJump(ZoneVector<BytecodeLabel>* labels, int index);
+  void EmitJumpIfTrue(ZoneVector<BytecodeLabel>* labels);
+  void EmitJumpIfTrue(ZoneVector<BytecodeLabel>* labels, int index);
+  void EmitJumpIfUndefined(ZoneVector<BytecodeLabel>* labels);
+  void EmitJumpIfNull(ZoneVector<BytecodeLabel>* labels);
+
+  void BindLabels(const BytecodeLabel& target, ZoneVector<BytecodeLabel>* site);
+
+ private:
+  // Unbound labels that identify jumps for break statements in the code.
+  ZoneVector<BytecodeLabel> break_sites_;
+};
+
 // A class to help with co-ordinating break and continue statements with
 // their loop.
 // TODO(oth): add support for TF branch/merge info.
-class LoopBuilder : public ControlFlowBuilder {
+class LoopBuilder final : public BreakableControlFlowBuilder {
  public:
   explicit LoopBuilder(BytecodeArrayBuilder* builder)
-      : ControlFlowBuilder(builder),
-        continue_sites_(builder->zone()),
-        break_sites_(builder->zone()) {}
+      : BreakableControlFlowBuilder(builder),
+        continue_sites_(builder->zone()) {}
   ~LoopBuilder();
 
-  // These methods should be called by the LoopBuilder owner before
-  // destruction to update sites that emit jumps for break/continue.
+  // This methods should be called by the LoopBuilder owner before
+  // destruction to update sites that emit jumps for continue.
   void SetContinueTarget(const BytecodeLabel& continue_target);
-  void SetBreakTarget(const BytecodeLabel& break_target);
 
-  // These methods are called when visiting break and continue
-  // statements in the AST.  Inserts a jump to a unbound label that is
-  // patched when the corresponding SetContinueTarget/SetBreakTarget
-  // is called.
-  void Break() { EmitJump(&break_sites_); }
-  void BreakIfTrue() { EmitJumpIfTrue(&break_sites_); }
-  void BreakIfUndefined() { EmitJumpIfUndefined(&break_sites_); }
-  void BreakIfNull() { EmitJumpIfNull(&break_sites_); }
+  // This method is called when visiting continue statements in the AST.
+  // Inserts a jump to a unbound label that is patched when the corresponding
+  // SetContinueTarget is called.
   void Continue() { EmitJump(&continue_sites_); }
   void ContinueIfTrue() { EmitJumpIfTrue(&continue_sites_); }
   void ContinueIfUndefined() { EmitJumpIfUndefined(&continue_sites_); }
   void ContinueIfNull() { EmitJumpIfNull(&continue_sites_); }
 
  private:
-  void BindLabels(const BytecodeLabel& target, ZoneVector<BytecodeLabel>* site);
-  void EmitJump(ZoneVector<BytecodeLabel>* labels);
-  void EmitJumpIfTrue(ZoneVector<BytecodeLabel>* labels);
-  void EmitJumpIfUndefined(ZoneVector<BytecodeLabel>* labels);
-  void EmitJumpIfNull(ZoneVector<BytecodeLabel>* labels);
+  // Unbound labels that identify jumps for continue statements in the code.
+  ZoneVector<BytecodeLabel> continue_sites_;
+};
 
-  // Unbound labels that identify jumps for continue/break statements
-  // in the code.
-  ZoneVector<BytecodeLabel> continue_sites_;
-  ZoneVector<BytecodeLabel> break_sites_;
+// A class to help with co-ordinating break statements with their switch.
+// TODO(oth): add support for TF branch/merge info.
+class SwitchBuilder final : public BreakableControlFlowBuilder {
+ public:
+  explicit SwitchBuilder(BytecodeArrayBuilder* builder, int number_of_cases)
+      : BreakableControlFlowBuilder(builder),
+        case_sites_(builder->zone()) {
+    case_sites_.resize(number_of_cases);
+  }
+  ~SwitchBuilder();
+
+  // This method should be called by the SwitchBuilder owner when the case
+  // statement with |index| is emitted to update the case jump site.
+  void SetCaseTarget(int index);
+
+  // This method is called when visiting case comparison operation for |index|.
+  // Inserts a JumpIfTrue to a unbound label that is patched when the
+  // corresponding SetCaseTarget is called.
+  void Case(int index) { EmitJumpIfTrue(&case_sites_, index); }
+
+  // This method is called when all cases comparisons have been emitted if there
+  // is a default case statement. Inserts a Jump to a unbound label that is
+  // patched when the corresponding SetCaseTarget is called.
+  void DefaultAt(int index) { EmitJump(&case_sites_, index); }
+
+ private:
+  // Unbound labels that identify jumps for case statements in the code.
+  ZoneVector<BytecodeLabel> case_sites_;
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_CONTROL_FLOW_BUILDERS_H_