Set debug break slot at init of loop variable in a for loop.

src/full-codegen.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1142 matching lines @@
   decrement_loop_depth();
 }
 
 
 void FullCodeGenerator::VisitForStatement(ForStatement* stmt) {
   Comment cmnt(masm_, "[ ForStatement");
   Label test, body;
 
   Iteration loop_statement(this, stmt);
   if (stmt->init() != NULL) {
+    SetStatementPosition(stmt);
     Visit(stmt->init());
   }
 
   increment_loop_depth();
   // Emit the test at the bottom of the loop (even if empty).
   __ jmp(&test);
 
   PrepareForBailoutForId(stmt->BodyId(), NO_REGISTERS);
   __ bind(&body);
   Visit(stmt->body());
 
   PrepareForBailoutForId(stmt->ContinueId(), NO_REGISTERS);
   __ bind(loop_statement.continue_label());
-  SetStatementPosition(stmt);
   if (stmt->next() != NULL) {
+    SetStatementPosition(stmt);

[Yang, 2012/03/07 18:28:36]

Only set a debug break slot if there is actually a statement.

     Visit(stmt->next());
   }
 
   // Emit the statement position here as this is where the for
   // statement code starts.
   SetStatementPosition(stmt);
 
   // Check stack before looping.
   EmitStackCheck(stmt, &body);
 
@@ skipping 230 matching lines @@
   }
 
   return false;
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal