Support for precise stepping in functions compiled before debugging was started (step 1)

src/objects.h

 // Copyright 2011 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 3667 matching lines @@
 
   // [optimizable]: For FUNCTION kind, tells if it is optimizable.
   inline bool optimizable();
   inline void set_optimizable(bool value);
 
   // [has_deoptimization_support]: For FUNCTION kind, tells if it has
   // deoptimization support.
   inline bool has_deoptimization_support();
   inline void set_has_deoptimization_support(bool value);
 
+  // [has_debug_break_slots]: For FUNCTION kind, tells if it has
+  // been compiled with debug break slots.
+  inline bool has_debug_break_slots();
+  inline void set_has_debug_break_slots(bool value);
+
   // [allow_osr_at_loop_nesting_level]: For FUNCTION kind, tells for
   // how long the function has been marked for OSR and therefore which
   // level of loop nesting we are willing to do on-stack replacement
   // for.
   inline void set_allow_osr_at_loop_nesting_level(int level);
   inline int allow_osr_at_loop_nesting_level();
 
   // [stack_slots]: For kind OPTIMIZED_FUNCTION, the number of stack slots
   // reserved in the code prologue.
   inline unsigned stack_slots();
@@ skipping 170 matching lines @@
   // Byte offsets within kKindSpecificFlagsOffset.
   static const int kStubMajorKeyOffset = kKindSpecificFlagsOffset;
   static const int kOptimizableOffset = kKindSpecificFlagsOffset;
   static const int kStackSlotsOffset = kKindSpecificFlagsOffset;
   static const int kCheckTypeOffset = kKindSpecificFlagsOffset;
 
   static const int kUnaryOpTypeOffset = kStubMajorKeyOffset + 1;
   static const int kBinaryOpTypeOffset = kStubMajorKeyOffset + 1;
   static const int kCompareStateOffset = kStubMajorKeyOffset + 1;
   static const int kToBooleanTypeOffset = kStubMajorKeyOffset + 1;
-  static const int kHasDeoptimizationSupportOffset = kOptimizableOffset + 1;
+
+  static const int kFullCodeFlags = kOptimizableOffset + 1;
+  static const int kFullCodeFlagsHasDeoptimizationSupportShift = 0;
+  static const int kFullCodeFlagsHasDebugBreakSlotsShift    = 1;
+  static const int kFullCodeFlagsHasDeoptimizationSupportMask = 0x01;
+  static const int kFullCodeFlagsHasDebugBreakSlotsMask    = 0x02;
 
   static const int kBinaryOpReturnTypeOffset = kBinaryOpTypeOffset + 1;
-  static const int kAllowOSRAtLoopNestingLevelOffset =
-      kHasDeoptimizationSupportOffset + 1;
+
+  static const int kAllowOSRAtLoopNestingLevelOffset = kFullCodeFlags + 1;
 
   static const int kSafepointTableOffsetOffset = kStackSlotsOffset + kIntSize;
   static const int kStackCheckTableOffsetOffset = kStackSlotsOffset + kIntSize;
 
   // Flags layout.
   static const int kFlagsICStateShift        = 0;
   static const int kFlagsICInLoopShift       = 3;
+
   static const int kFlagsTypeShift           = 4;
   static const int kFlagsKindShift           = 8;
   static const int kFlagsICHolderShift       = 12;
   static const int kFlagsExtraICStateShift   = 13;
   static const int kFlagsArgumentsCountShift = 15;
 
   static const int kFlagsICStateMask        = 0x00000007;  // 00000000111
   static const int kFlagsICInLoopMask       = 0x00000008;  // 00000001000
   static const int kFlagsTypeMask           = 0x000000F0;  // 00001110000
   static const int kFlagsKindMask           = 0x00000F00;  // 11110000000
@@ skipping 3558 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_