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

src/arm/assembler-arm.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 719 matching lines @@
   }
 
   // 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));
 
   // Given the address of the beginning of a call, return the address
   // in the instruction stream that the call will return from.
   INLINE(static Address return_address_from_call_start(Address pc));
 
-  // Return the code target address of the patch debug break slot
-  INLINE(static Address break_address_from_return_address(Address pc));
-
   // This sets the branch destination (which is in the constant pool on ARM).
   // This is for calls and branches within generated code.
   inline static void deserialization_set_special_target_at(
       Address constant_pool_entry, Code* code, Address target);
 
   // This sets the internal reference at the pc.
   inline static void deserialization_set_target_internal_reference_at(
       Address pc, Address target,
       RelocInfo::Mode mode = RelocInfo::INTERNAL_REFERENCE);
 
   // Here we are patching the address in the constant pool, not the actual call
   // instruction.  The address in the constant pool is the same size as a
   // pointer.
   static const int kSpecialTargetSize = kPointerSize;
 
   // Size of an instruction.
   static const int kInstrSize = sizeof(Instr);
 
-  // Distance between start of patched return sequence and the emitted address
-  // to jump to.
-  // Patched return sequence is:
-  //  ldr  ip, [pc, #0]   @ emited address and start
-  //  blx  ip
-  static const int kPatchReturnSequenceAddressOffset =  0 * kInstrSize;
-
   // Distance between start of patched debug break slot and the emitted address
   // to jump to.
   // Patched debug break slot code is:
   //  ldr  ip, [pc, #0]   @ emited address and start
   //  blx  ip
-  static const int kPatchDebugBreakSlotAddressOffset =  0 * kInstrSize;
-
-  static const int kPatchDebugBreakSlotReturnOffset = 2 * kInstrSize;
+  static const int kPatchDebugBreakSlotAddressOffset = 2 * kInstrSize;
 
   // Difference between address of current opcode and value read from pc
   // register.
   static const int kPcLoadDelta = 8;
 
-  static const int kJSReturnSequenceInstructions = 4;
-  static const int kJSReturnSequenceLength =
-      kJSReturnSequenceInstructions * kInstrSize;
-  static const int kDebugBreakSlotInstructions = 3;
+  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
   // of m. m must be a power of 2 (>= 4).
   void Align(int m);
@@ skipping 552 matching lines @@
     }
 
    private:
     Assembler* assem_;
 
     DISALLOW_IMPLICIT_CONSTRUCTORS(BlockConstPoolScope);
   };
 
   // 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 295 matching lines @@
  public:
   explicit EnsureSpace(Assembler* assembler) {
     assembler->CheckBuffer();
   }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_ARM_H_