Function unwindOneFrame

system/lib/libunwind/src/Unwind-EHABI.cpp:169–198

}

static _Unwind_Reason_Code unwindOneFrame(_Unwind_State state,
                                          _Unwind_Control_Block* ucbp,
                                          struct _Unwind_Context* context) {
  // Read the compact model EHT entry's header # 6.3
  const uint32_t* unwindingData = ucbp->pr_cache.ehtp;
  assert((*unwindingData & 0xf0000000) == 0x80000000 && "Must be a compact entry");
  Descriptor::Format format =
      static_cast<Descriptor::Format>((*unwindingData & 0x0f000000) >> 24);

  const char *lsda =
      reinterpret_cast<const char *>(_Unwind_GetLanguageSpecificData(context));

  // Handle descriptors before unwinding so they are processed in the context
  // of the correct stack frame.
  _Unwind_Reason_Code result =
      ProcessDescriptors(state, ucbp, context, format, lsda,
                         ucbp->pr_cache.additional);

  if (result != _URC_CONTINUE_UNWIND)
    return result;

  switch (__unw_step(reinterpret_cast<unw_cursor_t *>(context))) {
  case UNW_STEP_SUCCESS:
    return _URC_CONTINUE_UNWIND;
  case UNW_STEP_END:
    return _URC_END_OF_STACK;
  default:
    return _URC_FAILURE;
  }
}

// Generates mask discriminator for _Unwind_VRS_Pop, e.g. for _UVRSC_CORE /
// _UVRSD_UINT32.