[interpreter, debugger] fix remaining cctest failures.

src/interpreter/bytecode-generator.cc

 // 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.
 
 #include "src/interpreter/bytecode-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler.h"
 #include "src/interpreter/bytecode-register-allocator.h"
 #include "src/interpreter/control-flow-builders.h"
@@ skipping 950 matching lines @@
 }
 
 void BytecodeGenerator::VisitIterationBody(IterationStatement* stmt,
                                            LoopBuilder* loop_builder) {
   ControlScopeForIteration execution_control(this, stmt, loop_builder);
   builder()->StackCheck();
   Visit(stmt->body());
 }
 
 void BytecodeGenerator::VisitDoWhileStatement(DoWhileStatement* stmt) {
-  builder()->SetStatementPosition(stmt);

[Yang, 2016/03/15 09:32:12]

In FCG, we set a statement position, but no debug break slot. So it would be a
non-breakable statement position.

Originally, I worried that we may need to port that to ignition as well. But
now, if I'm not mistaken, we don't actually have to. A statement position that
is not associated with a break location has no value for the debugger. For stack
traces it does not matter either, since locations of stack traces are at calls
and throw sites, but not any of these statement positions that do not break.

So I think we could just omit them completely.

   LoopBuilder loop_builder(builder());
   loop_builder.LoopHeader();
   if (stmt->cond()->ToBooleanIsFalse()) {
     VisitIterationBody(stmt, &loop_builder);
     loop_builder.Condition();
   } else if (stmt->cond()->ToBooleanIsTrue()) {
     loop_builder.Condition();
     VisitIterationBody(stmt, &loop_builder);
     loop_builder.JumpToHeader();
   } else {
@@ skipping 21 matching lines @@
     loop_builder.BreakIfFalse();
   }
   VisitIterationBody(stmt, &loop_builder);
   loop_builder.JumpToHeader();
   loop_builder.EndLoop();
 }
 
 
 void BytecodeGenerator::VisitForStatement(ForStatement* stmt) {
   if (stmt->init() != nullptr) {
-    builder()->SetStatementPosition(stmt->init());
     Visit(stmt->init());
   }
   if (stmt->cond() && stmt->cond()->ToBooleanIsFalse()) {
     // If the condition is known to be false there is no need to generate
     // body, next or condition blocks. Init block should be generated.
     return;
   }
 
   LoopBuilder loop_builder(builder());
   loop_builder.LoopHeader();
@@ skipping 115 matching lines @@
   USE(cache_array);
   builder()->ForInPrepare(cache_type);
 
   // Set up loop counter
   Register index = register_allocator()->NewRegister();
   builder()->LoadLiteral(Smi::FromInt(0));
   builder()->StoreAccumulatorInRegister(index);
 
   // The loop
   loop_builder.LoopHeader();
+  builder()->SetExpressionAsStatementPosition(stmt->each());
   loop_builder.Condition();
   builder()->ForInDone(index, cache_length);
   loop_builder.BreakIfTrue();
   DCHECK(Register::AreContiguous(cache_type, cache_array));
   FeedbackVectorSlot slot = stmt->ForInFeedbackSlot();
   builder()->ForInNext(receiver, index, cache_type, feedback_index(slot));
   loop_builder.ContinueIfUndefined();
-  builder()->SetExpressionAsStatementPosition(stmt->each());
   VisitForInAssignment(stmt->each(), stmt->EachFeedbackSlot());
   VisitIterationBody(stmt, &loop_builder);
   loop_builder.Next();
   builder()->ForInStep(index);
   builder()->StoreAccumulatorInRegister(index);
   loop_builder.JumpToHeader();
   loop_builder.EndLoop();
   builder()->Bind(&subject_null_label);
   builder()->Bind(&subject_undefined_label);
 }
@@ skipping 1990 matching lines @@
 }
 
 
 int BytecodeGenerator::feedback_index(FeedbackVectorSlot slot) const {
   return info()->feedback_vector()->GetIndex(slot);
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8