[unwinder] Get rid of unused code

[rmaprath]

Summary

Hi Jon,

Spotted some obviously unused code in Unwind-EHABI.cpp while working on something else. This seem to have been introduced in revision 9f323e0fca08a0d60c51c4d0927cd1485b064913 by @logan. Didn't want to commit straight-away as I haven't touched the unwinder code yet. Feel free to commit on my behalf.

Thanks.

/ Asiri

[logan]

Sorry for the late reply. Thanks for your work. Yes, this is correct.

However, it seems that this differential can be closed since it has been committed as rL271737.

src/Unwind-EHABI.cpp

   // In this implementation, the phases don't share the VRS backing store.
   // Instead, they are passed the original |uc| and they create a new VRS
   // from scratch thus achieving the same effect.
   unw_cursor_t cursor1;
   unw_init_local(&cursor1, uc);
 
   // Walk each frame looking for a place to stop.
   for (bool handlerNotFound = true; handlerNotFound;) {
-
-#if !_LIBUNWIND_ARM_EHABI
-    // Ask libuwind to get next frame (skip over first which is
-    // _Unwind_RaiseException).
-    int stepResult = unw_step(&cursor1);
-    if (stepResult == 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step() reached "
-                                 "bottom => _URC_END_OF_STACK\n",
-                                 static_cast<void *>(exception_object));
-      return _URC_END_OF_STACK;
-    } else if (stepResult < 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step failed => "
-                                 "_URC_FATAL_PHASE1_ERROR\n",
-                                 static_cast<void *>(exception_object));
-      return _URC_FATAL_PHASE1_ERROR;
-    }
-#endif
-
     // See if frame has code to run (has personality routine).
     unw_proc_info_t frameInfo;
     if (unw_get_proc_info(&cursor1, &frameInfo) != UNW_ESUCCESS) {
       _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_get_proc_info "
                                  "failed => _URC_FATAL_PHASE1_ERROR\n",
                                  static_cast<void *>(exception_object));
       return _URC_FATAL_PHASE1_ERROR;
     }

   unw_init_local(&cursor2, uc);
 
   _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)\n",
                              static_cast<void *>(exception_object));
   int frame_count = 0;
 
   // Walk each frame until we reach where search phase said to stop.
   while (true) {
-    // Ask libuwind to get next frame (skip over first which is
-    // _Unwind_RaiseException or _Unwind_Resume).
-    //
     // Resume only ever makes sense for 1 frame.
     _Unwind_State state =
         resume ? _US_UNWIND_FRAME_RESUME : _US_UNWIND_FRAME_STARTING;
     if (resume && frame_count == 1) {
       // On a resume, first unwind the _Unwind_Resume() frame. The next frame
       // is now the landing pad for the cleanup from a previous execution of
       // phase2. To continue unwindingly correctly, replace VRS[15] with the
       // IP of the frame that the previous run of phase2 installed the context
       // for. After this, continue unwinding as if normal.
       //
       // See #7.4.6 for details.
       unw_set_reg(&cursor2, UNW_REG_IP,
                   exception_object->unwinder_cache.reserved2);
       resume = false;
     }
 
-#if !_LIBUNWIND_ARM_EHABI
-    int stepResult = unw_step(&cursor2);
-    if (stepResult == 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
-                                 "bottom => _URC_END_OF_STACK\n",
-                                 static_cast<void *>(exception_object));
-      return _URC_END_OF_STACK;
-    } else if (stepResult < 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step failed => "
-                                 "_URC_FATAL_PHASE1_ERROR\n",
-                                 static_cast<void *>(exception_object));
-      return _URC_FATAL_PHASE2_ERROR;
-    }
-#endif
-
     // Get info about this frame.
     unw_word_t sp;
     unw_proc_info_t frameInfo;
     unw_get_reg(&cursor2, UNW_REG_SP, &sp);
     if (unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) {
       _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_get_proc_info "
                                  "failed => _URC_FATAL_PHASE1_ERROR\n",
                                  static_cast<void *>(exception_object));