libphobos/libdruntime/gcc/unwind/arm_common.d

   1 // Exception handling and frame unwind runtime interface routines.
   2 // Copyright (C) 2011-2024 Free Software Foundation, Inc.
   3
   4 // GCC is free software; you can redistribute it and/or modify it under
   5 // the terms of the GNU General Public License as published by the Free
   6 // Software Foundation; either version 3, or (at your option) any later
   7 // version.
   8
   9 // GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  10 // WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 // FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12 // for more details.
  13
  14 // Under Section 7 of GPL version 3, you are granted additional
  15 // permissions described in the GCC Runtime Library Exception, version
  16 // 3.1, as published by the Free Software Foundation.
  17
  18 // You should have received a copy of the GNU General Public License and
  19 // a copy of the GCC Runtime Library Exception along with this program;
  20 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  21 // <http://www.gnu.org/licenses/>.
  22
  23 // extern(C) interface for the ARM EABI and C6X unwinders.
  24 // This corresponds to unwind-arm-common.h
  25
  26 module gcc.unwind.arm_common;
  27
  28 import gcc.config;
  29
  30 static if (GNU_ARM_EABI_Unwinder):
  31
  32 import gcc.builtins;
  33
  34 extern (C):
  35
  36 // Placed outside @nogc in order to not constrain what the callback does.
  37 // ??? Does this really need to be extern(C) alias?
  38 extern(C) alias _Unwind_Exception_Cleanup_Fn
  39     = void function(_Unwind_Reason_Code, _Unwind_Exception*);
  40
  41 extern(C) alias personality_routine
  42     = _Unwind_Reason_Code function(_Unwind_State,
  43                                    _Unwind_Control_Block*,
  44                                    _Unwind_Context*);
  45
  46 extern(C) alias _Unwind_Stop_Fn
  47     =_Unwind_Reason_Code function(int, _Unwind_Action,
  48                                   _Unwind_Exception_Class,
  49                                   _Unwind_Control_Block*,
  50                                   _Unwind_Context*, void*);
  51
  52 extern(C) alias _Unwind_Trace_Fn
  53     = _Unwind_Reason_Code function(_Unwind_Context*, void*);
  54
  55 @nogc:
  56
  57 alias _Unwind_Word = __builtin_machine_uint;
  58 alias _Unwind_Sword = __builtin_machine_int;
  59 alias _Unwind_Ptr = __builtin_pointer_uint;
  60 alias _Unwind_Internal_Ptr =__builtin_pointer_uint;
  61 alias _uw = _Unwind_Word;
  62 alias _uw64 = ulong;
  63 alias _uw16 = ushort;
  64 alias _uw8 = ubyte;
  65
  66 alias _Unwind_Reason_Code = uint;
  67 enum : _Unwind_Reason_Code
  68 {
  69     _URC_OK = 0,        // operation completed successfully
  70     _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
  71     _URC_END_OF_STACK = 5,
  72     _URC_HANDLER_FOUND = 6,
  73     _URC_INSTALL_CONTEXT = 7,
  74     _URC_CONTINUE_UNWIND = 8,
  75     _URC_FAILURE = 9    // unspecified failure of some kind
  76 }
  77
  78 alias _Unwind_State = int;
  79 enum : _Unwind_State
  80 {
  81     _US_VIRTUAL_UNWIND_FRAME = 0,
  82     _US_UNWIND_FRAME_STARTING = 1,
  83     _US_UNWIND_FRAME_RESUME = 2,
  84     _US_ACTION_MASK = 3,
  85     _US_FORCE_UNWIND = 8,
  86     _US_END_OF_STACK = 16
  87 }
  88
  89 // Provided only for for compatibility with existing code.
  90 alias _Unwind_Action = int;
  91 enum : _Unwind_Action
  92 {
  93     _UA_SEARCH_PHASE = 1,
  94     _UA_CLEANUP_PHASE = 2,
  95     _UA_HANDLER_FRAME = 4,
  96     _UA_FORCE_UNWIND = 8,
  97     _UA_END_OF_STACK = 16,
  98     _URC_NO_REASON = _URC_OK
  99 }
 100
 101 struct _Unwind_Context;
 102 alias _Unwind_EHT_Header = _uw;
 103
 104 struct _Unwind_Control_Block
 105 {
 106     _Unwind_Exception_Class exception_class = '\0';
 107     _Unwind_Exception_Cleanup_Fn exception_cleanup;
 108     // Unwinder cache, private fields for the unwinder's use
 109     struct _unwinder_cache
 110     {
 111         _uw reserved1;  // Forced unwind stop fn, 0 if not forced
 112         _uw reserved2;  // Personality routine address
 113         _uw reserved3;  // Saved callsite address
 114         _uw reserved4;  // Forced unwind stop arg
 115         _uw reserved5;
 116     }
 117     _unwinder_cache unwinder_cache;
 118     // Propagation barrier cache (valid after phase 1):
 119     struct _barrier_cache
 120     {
 121         _uw sp;
 122         _uw[5] bitpattern;
 123     }
 124     _barrier_cache barrier_cache;
 125     // Cleanup cache (preserved over cleanup):
 126     struct _cleanup_cache
 127     {
 128         _uw[4] bitpattern;
 129     }
 130     _cleanup_cache cleanup_cache;
 131     // Pr cache (for pr's benefit):
 132     struct _pr_cache
 133     {
 134         _uw fnstart;                // function start address */
 135         _Unwind_EHT_Header* ehtp;   // pointer to EHT entry header word
 136         _uw additional;             // additional data
 137         _uw reserved1;
 138     }
 139     _pr_cache pr_cache;
 140     long[0] _force_alignment;       // Force alignment to 8-byte boundary
 141 }
 142
 143 // Virtual Register Set
 144 alias _Unwind_VRS_RegClass = int;
 145 enum : _Unwind_VRS_RegClass
 146 {
 147     _UVRSC_CORE = 0,    // integer register
 148     _UVRSC_VFP = 1,     // vfp
 149     _UVRSC_FPA = 2,     // fpa
 150     _UVRSC_WMMXD = 3,   // Intel WMMX data register
 151     _UVRSC_WMMXC = 4    // Intel WMMX control register
 152 }
 153
 154 alias _Unwind_VRS_DataRepresentation = int;
 155 enum : _Unwind_VRS_DataRepresentation
 156 {
 157     _UVRSD_UINT32 = 0,
 158     _UVRSD_VFPX = 1,
 159     _UVRSD_FPAX = 2,
 160     _UVRSD_UINT64 = 3,
 161     _UVRSD_FLOAT = 4,
 162     _UVRSD_DOUBLE = 5
 163 }
 164
 165 alias _Unwind_VRS_Result = int;
 166 enum : _Unwind_VRS_Result
 167 {
 168     _UVRSR_OK = 0,
 169     _UVRSR_NOT_IMPLEMENTED = 1,
 170     _UVRSR_FAILED = 2
 171 }
 172
 173 // Frame unwinding state.
 174 struct __gnu_unwind_state
 175 {
 176     _uw data;           // The current word (bytes packed msb first).
 177     _uw* next;          // Pointer to the next word of data.
 178     _uw8 bytes_left;    // The number of bytes left in this word.
 179     _uw8 words_left;    // The number of words pointed to by ptr.
 180 }
 181
 182 _Unwind_VRS_Result _Unwind_VRS_Set(_Unwind_Context*, _Unwind_VRS_RegClass,
 183                                    _uw, _Unwind_VRS_DataRepresentation,
 184                                    void*);
 185
 186 _Unwind_VRS_Result _Unwind_VRS_Get(_Unwind_Context*, _Unwind_VRS_RegClass,
 187                                    _uw, _Unwind_VRS_DataRepresentation,
 188                                    void*);
 189
 190 _Unwind_VRS_Result _Unwind_VRS_Pop(_Unwind_Context*, _Unwind_VRS_RegClass,
 191                                    _uw, _Unwind_VRS_DataRepresentation);
 192
 193
 194 // Support functions for the PR.
 195 alias _Unwind_Exception = _Unwind_Control_Block;
 196 alias _Unwind_Exception_Class = char[8];
 197
 198 void* _Unwind_GetLanguageSpecificData(_Unwind_Context*);
 199 _Unwind_Ptr _Unwind_GetRegionStart(_Unwind_Context*);
 200
 201 _Unwind_Ptr _Unwind_GetDataRelBase(_Unwind_Context*);
 202 // This should never be used.
 203 _Unwind_Ptr _Unwind_GetTextRelBase(_Unwind_Context*);
 204
 205 // Interface functions:
 206 _Unwind_Reason_Code _Unwind_RaiseException(_Unwind_Control_Block*);
 207 void _Unwind_Resume(_Unwind_Control_Block*);
 208 _Unwind_Reason_Code _Unwind_Resume_or_Rethrow(_Unwind_Control_Block*);
 209
 210 _Unwind_Reason_Code _Unwind_ForcedUnwind(_Unwind_Control_Block*,
 211                                          _Unwind_Stop_Fn, void*);
 212
 213 // @@@ Use unwind data to perform a stack backtrace.  The trace callback
 214 // is called for every stack frame in the call chain, but no cleanup
 215 // actions are performed.
 216 _Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void*);
 217
 218 _Unwind_Word _Unwind_GetCFA(_Unwind_Context*);
 219 void _Unwind_Complete(_Unwind_Control_Block*);
 220 void _Unwind_DeleteException(_Unwind_Exception*);
 221
 222 _Unwind_Reason_Code __gnu_unwind_frame(_Unwind_Control_Block*,
 223                                        _Unwind_Context*);
 224 _Unwind_Reason_Code __gnu_unwind_execute(_Unwind_Context*,
 225                                          __gnu_unwind_state*);
 226
 227 _Unwind_Word _Unwind_GetGR(_Unwind_Context* context, int regno)
 228 {
 229     _uw val;
 230     _Unwind_VRS_Get(context, _UVRSC_CORE, regno, _UVRSD_UINT32, &val);
 231     return val;
 232 }
 233
 234 void _Unwind_SetGR(_Unwind_Context* context, int regno, _Unwind_Word val)
 235 {
 236     _Unwind_VRS_Set(context, _UVRSC_CORE, regno, _UVRSD_UINT32, &val);
 237 }
 238
 239 // leb128 type numbers have a potentially unlimited size.
 240 // The target of the following definitions of _sleb128_t and _uleb128_t
 241 // is to have efficient data types large enough to hold the leb128 type
 242 // numbers used in the unwind code.
 243 alias _sleb128_t = __builtin_clong;
 244 alias _uleb128_t = __builtin_culong;