Abstract out fetching of break_address in debug mode

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 792 matching lines @@
 
   // 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;
 
+  // Return the code target address of the patch debug break slot
+  inline static Address break_address_from_break_address(Address pc);

[rmcilroy, 2014/07/30 10:05:36]

Please use the INLINE() macro and move up to be below
return_address_from_call_start (for all arches).  Also, I think it should be
called break_address_from_return_address.

[andrew_low, 2014/07/30 14:06:46]

Done.

+
   // 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 kDebugBreakSlotInstructions = 3;
   static const int kDebugBreakSlotLength =
       kDebugBreakSlotInstructions * kInstrSize;
 
   // ---------------------------------------------------------------------------
@@ skipping 801 matching lines @@
  public:
   explicit EnsureSpace(Assembler* assembler) {
     assembler->CheckBuffer();
   }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_ARM_H_