libgcc/config/arm/unwind-arm.h

   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 */