1  /* Header file for the ARM EABI unwinder
       2     Copyright (C) 2003-2023 Free Software Foundation, Inc.
       3     Contributed by Paul Brook
       4  
       5     This file is free software; you can redistribute it and/or modify it
       6     under the terms of the GNU General Public License as published by the
       7     Free Software Foundation; either version 3, or (at your option) any
       8     later version.
       9  
      10     This file is distributed in the hope that it will be useful, but
      11     WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     General Public License for more details.
      14  
      15     Under Section 7 of GPL version 3, you are granted additional
      16     permissions described in the GCC Runtime Library Exception, version
      17     3.1, as published by the Free Software Foundation.
      18  
      19     You should have received a copy of the GNU General Public License and
      20     a copy of the GCC Runtime Library Exception along with this program;
      21     see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      22     <http://www.gnu.org/licenses/>.  */
      23  
      24  /* Language-independent unwinder header public defines.  This contains both
      25     ABI defined objects, and GNU support routines.  */
      26  
      27  #ifndef UNWIND_ARM_H
      28  #define UNWIND_ARM_H
      29  
      30  #include "unwind-arm-common.h"
      31  
      32  #define UNWIND_STACK_REG 13
      33  /* Use IP as a scratch register within the personality routine.  */
      34  #define UNWIND_POINTER_REG 12
      35  
      36  #define FDPIC_REGNUM 9
      37  
      38  #define STR(x) #x
      39  #define XSTR(x) STR(x)
      40  
      41  #ifdef __cplusplus
      42  extern "C" {
      43  #endif
      44  _Unwind_Ptr __attribute__((weak)) __gnu_Unwind_Find_got (_Unwind_Ptr);
      45  
      46  static inline _Unwind_Ptr _Unwind_gnu_Find_got (_Unwind_Ptr ptr)
      47  {
      48      _Unwind_Ptr res;
      49  
      50      if (__gnu_Unwind_Find_got)
      51  	res = __gnu_Unwind_Find_got (ptr);
      52      else
      53  	__asm volatile ("mov %[result], r" XSTR(FDPIC_REGNUM)
      54  			: [result] "=r" (res));
      55  
      56      return res;
      57  }
      58  
      59    /* Decode an R_ARM_TARGET2 relocation.  */
      60    static inline _Unwind_Word
      61    _Unwind_decode_typeinfo_ptr (_Unwind_Word base __attribute__ ((unused)),
      62                                 _Unwind_Word ptr)
      63      {
      64        _Unwind_Word tmp;
      65  
      66        tmp = *(_Unwind_Word *) ptr;
      67        /* Zero values are always NULL.  */
      68        if (!tmp)
      69  	return 0;
      70  
      71  #if __FDPIC__
      72        /* For FDPIC, we store the offset of the GOT entry.  */
      73        /* So, first get GOT from dynamic linker and then use indirect access.  */
      74        tmp += _Unwind_gnu_Find_got (ptr);
      75        tmp = *(_Unwind_Word *) tmp;
      76  #elif (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \
      77      || defined(__FreeBSD__) || defined(__fuchsia__)
      78        /* Pc-relative indirect.  */
      79  #define _GLIBCXX_OVERRIDE_TTYPE_ENCODING (DW_EH_PE_pcrel | DW_EH_PE_indirect)
      80        tmp += ptr;
      81        tmp = *(_Unwind_Word *) tmp;
      82  #elif defined(__symbian__) || defined(__uClinux__)
      83  #define _GLIBCXX_OVERRIDE_TTYPE_ENCODING (DW_EH_PE_absptr)
      84        /* Absolute pointer.  Nothing more to do.  */
      85  #else
      86  #define _GLIBCXX_OVERRIDE_TTYPE_ENCODING (DW_EH_PE_pcrel)
      87        /* Pc-relative pointer.  */
      88        tmp += ptr;
      89  #endif
      90        return tmp;
      91      }
      92  
      93    static inline _Unwind_Reason_Code
      94    __gnu_unwind_24bit (_Unwind_Context * context __attribute__ ((unused)),
      95                        _uw data __attribute__ ((unused)),
      96                        int compact __attribute__ ((unused)))
      97      {
      98        return _URC_FAILURE;
      99      }
     100  #ifndef __FreeBSD__
     101    /* Return the address of the instruction, not the actual IP value.  */
     102  #define _Unwind_GetIP(context) \
     103    (_Unwind_GetGR (context, 15) & ~(_Unwind_Word)1)
     104  
     105  #define _Unwind_SetIP(context, val) \
     106    _Unwind_SetGR (context, 15, val | (_Unwind_GetGR (context, 15) & 1))
     107  #else
     108    #undef _Unwind_GetIPInfo
     109    _Unwind_Ptr _Unwind_GetIP (struct _Unwind_Context *);
     110    _Unwind_Ptr _Unwind_GetIPInfo (struct _Unwind_Context *, int *);
     111    void _Unwind_SetIP (struct _Unwind_Context *, _Unwind_Ptr);
     112  #endif
     113  
     114  #ifdef __cplusplus
     115  }   /* extern "C" */
     116  #endif
     117  
     118  #endif /* defined UNWIND_ARM_H */