external/bsd/libc++/dist/libcxxrt/src/unwind-arm.h

   1 /*
   2  * Copyright 2012 David Chisnall. All rights reserved.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to
   6  * deal in the Software without restriction, including without limitation the
   7  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   8  * sell copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be
  12  * included in all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  15  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  17  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  18  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  19  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  20  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21  */
  22
  23 /**
  24  * ARM-specific unwind definitions.  These are taken from the ARM EHABI
  25  * specification.
  26  */
  27  typedef enum
  28 {
  29         _URC_OK = 0,                /* operation completed successfully */
  30         _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
  31     _URC_END_OF_STACK = 5,
  32         _URC_HANDLER_FOUND = 6,
  33         _URC_INSTALL_CONTEXT = 7,
  34         _URC_CONTINUE_UNWIND = 8,
  35         _URC_FAILURE = 9,            /* unspecified failure of some kind */
  36         _URC_FATAL_PHASE1_ERROR = _URC_FAILURE
  37 } _Unwind_Reason_Code;
  38
  39 typedef uint32_t _Unwind_State;
  40 #ifdef __clang__
  41 static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME  = 0;
  42 static const _Unwind_State _US_UNWIND_FRAME_STARTING = 1;
  43 static const _Unwind_State _US_UNWIND_FRAME_RESUME   = 2;
  44 #else // GCC fails at knowing what a constant expression is
  45 #       define _US_VIRTUAL_UNWIND_FRAME  0
  46 #       define _US_UNWIND_FRAME_STARTING 1
  47 #       define _US_UNWIND_FRAME_RESUME 2
  48 #endif
  49
  50 typedef struct _Unwind_Context _Unwind_Context;
  51
  52 typedef uint32_t _Unwind_EHT_Header;
  53
  54 struct _Unwind_Exception
  55 {
  56         uint64_t exception_class;
  57         void (*exception_cleanup)(_Unwind_Reason_Code, struct _Unwind_Exception *);
  58         /* Unwinder cache, private fields for the unwinder's use */
  59         struct
  60         {
  61                 uint32_t reserved1;
  62                 uint32_t reserved2;
  63                 uint32_t reserved3;
  64                 uint32_t reserved4;
  65                 uint32_t reserved5;
  66         /* init reserved1 to 0, then don't touch */
  67         } unwinder_cache;
  68         /* Propagation barrier cache (valid after phase 1): */
  69         struct
  70         {
  71                 uint32_t sp;
  72                 uint32_t bitpattern[5];
  73         } barrier_cache;
  74         /* Cleanup cache (preserved over cleanup): */
  75         struct
  76         {
  77                 uint32_t bitpattern[4];
  78         } cleanup_cache;
  79         /* Pr cache (for pr's benefit): */
  80         struct
  81         {
  82                 /** function start address */
  83                 uint32_t fnstart;
  84                 /** pointer to EHT entry header word */
  85                 _Unwind_EHT_Header *ehtp;
  86                 /** additional data */
  87                 uint32_t additional;
  88                 uint32_t reserved1;
  89         } pr_cache;
  90         /** Force alignment of next item to 8-byte boundary */
  91         long long int :0;
  92 };
  93
  94 /* Unwinding functions */
  95 _Unwind_Reason_Code _Unwind_RaiseException(struct _Unwind_Exception *ucbp);
  96 void _Unwind_Resume(struct _Unwind_Exception *ucbp);
  97 void _Unwind_Complete(struct _Unwind_Exception *ucbp);
  98 void _Unwind_DeleteException(struct _Unwind_Exception *ucbp);
  99 void *_Unwind_GetLanguageSpecificData(struct _Unwind_Context*);
 100
 101 typedef enum
 102 {
 103         _UVRSR_OK = 0,
 104         _UVRSR_NOT_IMPLEMENTED = 1,
 105         _UVRSR_FAILED = 2
 106 } _Unwind_VRS_Result;
 107 typedef enum
 108 {
 109         _UVRSC_CORE = 0,
 110         _UVRSC_VFP = 1,
 111         _UVRSC_WMMXD = 3,
 112         _UVRSC_WMMXC = 4
 113 } _Unwind_VRS_RegClass;
 114 typedef enum
 115 {
 116         _UVRSD_UINT32 = 0,
 117         _UVRSD_VFPX = 1,
 118         _UVRSD_UINT64 = 3,
 119         _UVRSD_FLOAT = 4,
 120         _UVRSD_DOUBLE = 5
 121 } _Unwind_VRS_DataRepresentation;
 122
 123 _Unwind_VRS_Result _Unwind_VRS_Get(_Unwind_Context *context,
 124                                    _Unwind_VRS_RegClass regclass,
 125                                    uint32_t regno,
 126                                    _Unwind_VRS_DataRepresentation representation,
 127                                    void *valuep);
 128 _Unwind_VRS_Result _Unwind_VRS_Set(_Unwind_Context *context,
 129                                    _Unwind_VRS_RegClass regclass,
 130                                    uint32_t regno,
 131                                    _Unwind_VRS_DataRepresentation representation,
 132                                    void *valuep);
 133
 134 /* Return the base-address for data references.  */
 135 extern unsigned long _Unwind_GetDataRelBase(struct _Unwind_Context *);
 136
 137 /* Return the base-address for text references.  */
 138 extern unsigned long _Unwind_GetTextRelBase(struct _Unwind_Context *);
 139 extern unsigned long _Unwind_GetRegionStart(struct _Unwind_Context *);
 140
 141 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn) (struct _Unwind_Context *,
 142                                                  void *);
 143 extern _Unwind_Reason_Code _Unwind_Backtrace (_Unwind_Trace_Fn, void *);
 144 extern _Unwind_Reason_Code
 145           _Unwind_Resume_or_Rethrow (struct _Unwind_Exception *);
 146
 147 /**
 148  * The next set of functions are compatibility extensions, implementing Itanium
 149  * ABI functions on top of ARM ones.
 150  */
 151
 152 #define _UA_SEARCH_PHASE        1
 153 #define _UA_CLEANUP_PHASE       2
 154 #define _UA_HANDLER_FRAME       4
 155 #define _UA_FORCE_UNWIND        8
 156
 157 static inline unsigned long _Unwind_GetGR(struct _Unwind_Context *context, int reg)
 158 {
 159         unsigned long val;
 160         _Unwind_VRS_Get(context, _UVRSC_CORE, reg, _UVRSD_UINT32, &val);
 161         return val;
 162 }
 163 static inline  void _Unwind_SetGR(struct _Unwind_Context *context, int reg, unsigned long val)
 164 {
 165         _Unwind_VRS_Set(context, _UVRSC_CORE, reg, _UVRSD_UINT32, &val);
 166 }
 167 static inline unsigned long _Unwind_GetIP(_Unwind_Context *context)
 168 {
 169         // Low bit store the thumb state - discard it
 170         return _Unwind_GetGR(context, 15) & ~1;
 171 }
 172 static inline void _Unwind_SetIP(_Unwind_Context *context, unsigned long val)
 173 {
 174         // The lowest bit of the instruction pointer indicates whether we're in
 175         // thumb or ARM mode.  This is assumed to be fixed throughout a function,
 176         // so must be propagated when setting the program counter.
 177         unsigned long thumbState = _Unwind_GetGR(context, 15) & 1;
 178    _Unwind_SetGR(context, 15, (val | thumbState));
 179 }
 180
 181 /** GNU API function that unwinds the frame */
 182 _Unwind_Reason_Code __gnu_unwind_frame(struct _Unwind_Exception*, struct _Unwind_Context*);
 183
 184
 185 #define DECLARE_PERSONALITY_FUNCTION(name) \
 186 _Unwind_Reason_Code name(_Unwind_State state,\
 187                          struct _Unwind_Exception *exceptionObject,\
 188                          struct _Unwind_Context *context);
 189
 190 #define BEGIN_PERSONALITY_FUNCTION(name) \
 191 _Unwind_Reason_Code name(_Unwind_State state,\
 192                          struct _Unwind_Exception *exceptionObject,\
 193                          struct _Unwind_Context *context)\
 194 {\
 195         int version = 1;\
 196         uint64_t exceptionClass = exceptionObject->exception_class;\
 197         int actions;\
 198         switch (state)\
 199         {\
 200                 default: return _URC_FAILURE;\
 201                 case _US_VIRTUAL_UNWIND_FRAME:\
 202                 {\
 203                         actions = _UA_SEARCH_PHASE;\
 204                         break;\
 205                 }\
 206                 case _US_UNWIND_FRAME_STARTING:\
 207                 {\
 208                         actions = _UA_CLEANUP_PHASE;\
 209                         if (exceptionObject->barrier_cache.sp == _Unwind_GetGR(context, 13))\
 210                         {\
 211                                 actions |= _UA_HANDLER_FRAME;\
 212                         }\
 213                         break;\
 214                 }\
 215                 case _US_UNWIND_FRAME_RESUME:\
 216                 {\
 217                         return continueUnwinding(exceptionObject, context);\
 218                         break;\
 219                 }\
 220         }\
 221         _Unwind_SetGR (context, 12, reinterpret_cast<unsigned long>(exceptionObject));\
 222
 223 #define CALL_PERSONALITY_FUNCTION(name) name(state,exceptionObject,context)