Debugger: use debug break slots to break at function exit.

src/mips/assembler-mips.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 507 matching lines @@
                                            ICacheFlushMode icache_flush_mode =
                                                FLUSH_ICACHE_IF_NEEDED)) {
     Address constant_pool = code ? code->constant_pool() : NULL;
     set_target_address_at(pc, constant_pool, target, icache_flush_mode);
   }
 
   // Return the code target address at a call site from the return address
   // of that call in the instruction stream.
   inline static Address target_address_from_return_address(Address pc);
 
-  // Return the code target address of the patch debug break slot
-  inline static Address break_address_from_return_address(Address pc);
-
   static void JumpToJumpRegister(Address pc);
 
   static void QuietNaN(HeapObject* nan);
 
   // This sets the branch destination (which gets loaded at the call address).
   // This is for calls and branches within generated code.  The serializer
   // has already deserialized the lui/ori instructions etc.
   inline static void deserialization_set_special_target_at(
       Address instruction_payload, Code* code, Address target) {
     set_target_address_at(
@@ skipping 27 matching lines @@
   // the instruction that follows LUI/ORI instruction pair. Now, with new jump
   // optimization, where jump-through-register instruction that usually
   // follows LUI/ORI pair is substituted with J/JAL, this constant equals
   // to 3 instructions (LUI+ORI+J/JAL/JR/JALR).
   static const int kInstructionsFor32BitConstant = 3;
 
   // Distance between the instruction referring to the address of the call
   // target and the return address.
   static const int kCallTargetAddressOffset = 4 * kInstrSize;
 
-  // Distance between start of patched return sequence and the emitted address
-  // to jump to.
-  static const int kPatchReturnSequenceAddressOffset = 0;
-
   // Distance between start of patched debug break slot and the emitted address
   // to jump to.
-  static const int kPatchDebugBreakSlotAddressOffset =  0 * kInstrSize;
+  static const int kPatchDebugBreakSlotAddressOffset = 4 * kInstrSize;
 
   // Difference between address of current opcode and value read from pc
   // register.
   static const int kPcLoadDelta = 4;
 
-  static const int kPatchDebugBreakSlotReturnOffset = 4 * kInstrSize;
-
-  // Number of instructions used for the JS return sequence. The constant is
-  // used by the debugger to patch the JS return sequence.
-  static const int kJSReturnSequenceInstructions = 7;
-  static const int kJSReturnSequenceLength =
-      kJSReturnSequenceInstructions * kInstrSize;
   static const int kDebugBreakSlotInstructions = 4;
   static const int kDebugBreakSlotLength =
       kDebugBreakSlotInstructions * kInstrSize;
 
 
   // ---------------------------------------------------------------------------
   // Code generation.
 
   // Insert the smallest number of nop instructions
   // possible to align the pc offset to a multiple
@@ skipping 444 matching lines @@
     }
 
    private:
     Assembler* assem_;
 
     DISALLOW_IMPLICIT_CONSTRUCTORS(BlockGrowBufferScope);
   };
 
   // Debugging.
 
-  // Mark address of the ExitJSFrame code.
-  void RecordJSReturn();
-
   // Mark generator continuation.
   void RecordGeneratorContinuation();
 
   // Mark address of a debug break slot.
-  void RecordDebugBreakSlot();
-  void RecordDebugBreakSlotForCall(int argc);
-  void RecordDebugBreakSlotForConstructCall();
+  void RecordDebugBreakSlot(RelocInfo::Mode mode, int argc = 0);
 
   // Record the AST id of the CallIC being compiled, so that it can be placed
   // in the relocation information.
   void SetRecordedAstId(TypeFeedbackId ast_id) {
     DCHECK(recorded_ast_id_.IsNone());
     recorded_ast_id_ = ast_id;
   }
 
   TypeFeedbackId RecordedAstId() {
     DCHECK(!recorded_ast_id_.IsNone());
@@ skipping 383 matching lines @@
 class EnsureSpace BASE_EMBEDDED {
  public:
   explicit EnsureSpace(Assembler* assembler) {
     assembler->CheckBuffer();
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_MIPS_H_