[Interpreter] Add support for break statements in labelled blocks.

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 30 matching lines @@
 
   // 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 BreakIfFalse() { EmitJumpIfFalse(&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 EmitJumpIfFalse(ZoneVector<BytecodeLabel>* labels);
   void EmitJumpIfFalse(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_;
 };
 
+
+// Class to track control flow for block statements (which can break in JS).
+class BlockBuilder final : public BreakableControlFlowBuilder {
+ public:
+  explicit BlockBuilder(BytecodeArrayBuilder* builder)
+      : BreakableControlFlowBuilder(builder) {}
+
+  void EndBlock();
+
+ private:
+  BytecodeLabel block_end_;
+};
+
+
 // A class to help with co-ordinating break and continue statements with
 // their loop.
 class LoopBuilder final : public BreakableControlFlowBuilder {
  public:
   explicit LoopBuilder(BytecodeArrayBuilder* builder)
       : BreakableControlFlowBuilder(builder),
         continue_sites_(builder->zone()) {}
   ~LoopBuilder();
 
   void LoopHeader() { builder()->Bind(&loop_header_); }
   void Condition() { builder()->Bind(&condition_); }
   void Next() { builder()->Bind(&next_); }
   void JumpToHeader() { builder()->Jump(&loop_header_); }
   void JumpToHeaderIfTrue() { builder()->JumpIfTrue(&loop_header_); }
-  void LoopEnd();
+  void EndLoop();
 
   // 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 SetContinueTarget(const BytecodeLabel& continue_target);
 
   BytecodeLabel loop_header_;
   BytecodeLabel condition_;
   BytecodeLabel next_;
   BytecodeLabel loop_end_;
 
   // Unbound labels that identify jumps for continue statements in the code.
   ZoneVector<BytecodeLabel> continue_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
@@ skipping 13 matching lines @@
  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_