clang/lib/Headers/unwind.h

   1 /*===---- unwind.h - Stack unwinding ----------------------------------------===
   2  *
   3  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4  * See https://llvm.org/LICENSE.txt for license information.
   5  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6  *
   7  *===-----------------------------------------------------------------------===
   8  */
   9
  10 /* See "Data Definitions for libgcc_s" in the Linux Standard Base.*/
  11
  12 #ifndef __CLANG_UNWIND_H
  13 #define __CLANG_UNWIND_H
  14
  15 #if defined(__APPLE__) && __has_include_next(<unwind.h>)
  16 /* Darwin (from 11.x on) provide an unwind.h. If that's available,
  17  * use it. libunwind wraps some of its definitions in #ifdef _GNU_SOURCE,
  18  * so define that around the include.*/
  19 # ifndef _GNU_SOURCE
  20 #  define _SHOULD_UNDEFINE_GNU_SOURCE
  21 #  define _GNU_SOURCE
  22 # endif
  23 // libunwind's unwind.h reflects the current visibility.  However, Mozilla
  24 // builds with -fvisibility=hidden and relies on gcc's unwind.h to reset the
  25 // visibility to default and export its contents.  gcc also allows users to
  26 // override its override by #defining HIDE_EXPORTS (but note, this only obeys
  27 // the user's -fvisibility setting; it doesn't hide any exports on its own).  We
  28 // imitate gcc's header here:
  29 # ifdef HIDE_EXPORTS
  30 #  include_next <unwind.h>
  31 # else
  32 #  pragma GCC visibility push(default)
  33 #  include_next <unwind.h>
  34 #  pragma GCC visibility pop
  35 # endif
  36 # ifdef _SHOULD_UNDEFINE_GNU_SOURCE
  37 #  undef _GNU_SOURCE
  38 #  undef _SHOULD_UNDEFINE_GNU_SOURCE
  39 # endif
  40 #else
  41
  42 #include <stdint.h>
  43
  44 #ifdef __cplusplus
  45 extern "C" {
  46 #endif
  47
  48 /* It is a bit strange for a header to play with the visibility of the
  49    symbols it declares, but this matches gcc's behavior and some programs
  50    depend on it */
  51 #ifndef HIDE_EXPORTS
  52 #pragma GCC visibility push(default)
  53 #endif
  54
  55 typedef uintptr_t _Unwind_Word __attribute__((__mode__(__unwind_word__)));
  56 typedef intptr_t _Unwind_Sword __attribute__((__mode__(__unwind_word__)));
  57 typedef uintptr_t _Unwind_Ptr;
  58 typedef uintptr_t _Unwind_Internal_Ptr;
  59 typedef uint64_t _Unwind_Exception_Class;
  60
  61 typedef intptr_t _sleb128_t;
  62 typedef uintptr_t _uleb128_t;
  63
  64 struct _Unwind_Context;
  65 #if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) || \
  66                           defined(__ARM_DWARF_EH__) || defined(__SEH__))
  67 struct _Unwind_Control_Block;
  68 typedef struct _Unwind_Control_Block _Unwind_Exception; /* Alias */
  69 #else
  70 struct _Unwind_Exception;
  71 typedef struct _Unwind_Exception _Unwind_Exception;
  72 #endif
  73 typedef enum {
  74   _URC_NO_REASON = 0,
  75 #if defined(__arm__) && !defined(__USING_SJLJ_EXCEPTIONS__) && \
  76     !defined(__ARM_DWARF_EH__) && !defined(__SEH__)
  77   _URC_OK = 0, /* used by ARM EHABI */
  78 #endif
  79   _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
  80
  81   _URC_FATAL_PHASE2_ERROR = 2,
  82   _URC_FATAL_PHASE1_ERROR = 3,
  83   _URC_NORMAL_STOP = 4,
  84
  85   _URC_END_OF_STACK = 5,
  86   _URC_HANDLER_FOUND = 6,
  87   _URC_INSTALL_CONTEXT = 7,
  88   _URC_CONTINUE_UNWIND = 8,
  89 #if defined(__arm__) && !defined(__USING_SJLJ_EXCEPTIONS__) && \
  90     !defined(__ARM_DWARF_EH__) && !defined(__SEH__)
  91   _URC_FAILURE = 9 /* used by ARM EHABI */
  92 #endif
  93 } _Unwind_Reason_Code;
  94
  95 typedef enum {
  96   _UA_SEARCH_PHASE = 1,
  97   _UA_CLEANUP_PHASE = 2,
  98
  99   _UA_HANDLER_FRAME = 4,
 100   _UA_FORCE_UNWIND = 8,
 101   _UA_END_OF_STACK = 16 /* gcc extension to C++ ABI */
 102 } _Unwind_Action;
 103
 104 typedef void (*_Unwind_Exception_Cleanup_Fn)(_Unwind_Reason_Code,
 105                                              _Unwind_Exception *);
 106
 107 #if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) || \
 108                           defined(__ARM_DWARF_EH__) || defined(__SEH__))
 109 typedef struct _Unwind_Control_Block _Unwind_Control_Block;
 110 typedef uint32_t _Unwind_EHT_Header;
 111
 112 struct _Unwind_Control_Block {
 113   uint64_t exception_class;
 114   void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block *);
 115   /* unwinder cache (private fields for the unwinder's use) */
 116   struct {
 117     uint32_t reserved1; /* forced unwind stop function, 0 if not forced */
 118     uint32_t reserved2; /* personality routine */
 119     uint32_t reserved3; /* callsite */
 120     uint32_t reserved4; /* forced unwind stop argument */
 121     uint32_t reserved5;
 122   } unwinder_cache;
 123   /* propagation barrier cache (valid after phase 1) */
 124   struct {
 125     uint32_t sp;
 126     uint32_t bitpattern[5];
 127   } barrier_cache;
 128   /* cleanup cache (preserved over cleanup) */
 129   struct {
 130     uint32_t bitpattern[4];
 131   } cleanup_cache;
 132   /* personality cache (for personality's benefit) */
 133   struct {
 134     uint32_t fnstart;         /* function start address */
 135     _Unwind_EHT_Header *ehtp; /* pointer to EHT entry header word */
 136     uint32_t additional;      /* additional data */
 137     uint32_t reserved1;
 138   } pr_cache;
 139   long long int : 0; /* force alignment of next item to 8-byte boundary */
 140 } __attribute__((__aligned__(8)));
 141 #else
 142 struct _Unwind_Exception {
 143   _Unwind_Exception_Class exception_class;
 144   _Unwind_Exception_Cleanup_Fn exception_cleanup;
 145 #if !defined (__USING_SJLJ_EXCEPTIONS__) && defined (__SEH__)
 146   _Unwind_Word private_[6];
 147 #else
 148   _Unwind_Word private_1;
 149   _Unwind_Word private_2;
 150 #endif
 151   /* The Itanium ABI requires that _Unwind_Exception objects are "double-word
 152    * aligned".  GCC has interpreted this to mean "use the maximum useful
 153    * alignment for the target"; so do we. */
 154 } __attribute__((__aligned__));
 155 #endif
 156
 157 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)(int, _Unwind_Action,
 158                                                _Unwind_Exception_Class,
 159                                                _Unwind_Exception *,
 160                                                struct _Unwind_Context *,
 161                                                void *);
 162
 163 typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(int, _Unwind_Action,
 164                                                       _Unwind_Exception_Class,
 165                                                       _Unwind_Exception *,
 166                                                       struct _Unwind_Context *);
 167 typedef _Unwind_Personality_Fn __personality_routine;
 168
 169 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *,
 170                                                 void *);
 171
 172 #if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) ||                \
 173                           defined(__ARM_DWARF_EH__) || defined(__SEH__))
 174 typedef enum {
 175   _UVRSC_CORE = 0,        /* integer register */
 176   _UVRSC_VFP = 1,         /* vfp */
 177   _UVRSC_WMMXD = 3,       /* Intel WMMX data register */
 178   _UVRSC_WMMXC = 4,       /* Intel WMMX control register */
 179   _UVRSC_PSEUDO = 5       /* Special purpose pseudo register */
 180 } _Unwind_VRS_RegClass;
 181
 182 typedef enum {
 183   _UVRSD_UINT32 = 0,
 184   _UVRSD_VFPX = 1,
 185   _UVRSD_UINT64 = 3,
 186   _UVRSD_FLOAT = 4,
 187   _UVRSD_DOUBLE = 5
 188 } _Unwind_VRS_DataRepresentation;
 189
 190 typedef enum {
 191   _UVRSR_OK = 0,
 192   _UVRSR_NOT_IMPLEMENTED = 1,
 193   _UVRSR_FAILED = 2
 194 } _Unwind_VRS_Result;
 195
 196 typedef uint32_t _Unwind_State;
 197 #define _US_VIRTUAL_UNWIND_FRAME  ((_Unwind_State)0)
 198 #define _US_UNWIND_FRAME_STARTING ((_Unwind_State)1)
 199 #define _US_UNWIND_FRAME_RESUME   ((_Unwind_State)2)
 200 #define _US_ACTION_MASK           ((_Unwind_State)3)
 201 #define _US_FORCE_UNWIND          ((_Unwind_State)8)
 202
 203 _Unwind_VRS_Result _Unwind_VRS_Get(struct _Unwind_Context *__context,
 204   _Unwind_VRS_RegClass __regclass,
 205   uint32_t __regno,
 206   _Unwind_VRS_DataRepresentation __representation,
 207   void *__valuep);
 208
 209 _Unwind_VRS_Result _Unwind_VRS_Set(struct _Unwind_Context *__context,
 210   _Unwind_VRS_RegClass __regclass,
 211   uint32_t __regno,
 212   _Unwind_VRS_DataRepresentation __representation,
 213   void *__valuep);
 214
 215 static __inline__
 216 _Unwind_Word _Unwind_GetGR(struct _Unwind_Context *__context, int __index) {
 217   _Unwind_Word __value;
 218   _Unwind_VRS_Get(__context, _UVRSC_CORE, __index, _UVRSD_UINT32, &__value);
 219   return __value;
 220 }
 221
 222 static __inline__
 223 void _Unwind_SetGR(struct _Unwind_Context *__context, int __index,
 224                    _Unwind_Word __value) {
 225   _Unwind_VRS_Set(__context, _UVRSC_CORE, __index, _UVRSD_UINT32, &__value);
 226 }
 227
 228 static __inline__
 229 _Unwind_Word _Unwind_GetIP(struct _Unwind_Context *__context) {
 230   _Unwind_Word __ip = _Unwind_GetGR(__context, 15);
 231   return __ip & ~(_Unwind_Word)(0x1); /* Remove thumb mode bit. */
 232 }
 233
 234 static __inline__
 235 void _Unwind_SetIP(struct _Unwind_Context *__context, _Unwind_Word __value) {
 236   _Unwind_Word __thumb_mode_bit = _Unwind_GetGR(__context, 15) & 0x1;
 237   _Unwind_SetGR(__context, 15, __value | __thumb_mode_bit);
 238 }
 239 #else
 240 _Unwind_Word _Unwind_GetGR(struct _Unwind_Context *, int);
 241 void _Unwind_SetGR(struct _Unwind_Context *, int, _Unwind_Word);
 242
 243 _Unwind_Word _Unwind_GetIP(struct _Unwind_Context *);
 244 void _Unwind_SetIP(struct _Unwind_Context *, _Unwind_Word);
 245 #endif
 246
 247
 248 _Unwind_Word _Unwind_GetIPInfo(struct _Unwind_Context *, int *);
 249
 250 _Unwind_Word _Unwind_GetCFA(struct _Unwind_Context *);
 251
 252 _Unwind_Word _Unwind_GetBSP(struct _Unwind_Context *);
 253
 254 void *_Unwind_GetLanguageSpecificData(struct _Unwind_Context *);
 255
 256 _Unwind_Ptr _Unwind_GetRegionStart(struct _Unwind_Context *);
 257
 258 /* DWARF EH functions; currently not available on Darwin/ARM */
 259 #if !defined(__APPLE__) || !defined(__arm__)
 260 _Unwind_Reason_Code _Unwind_RaiseException(_Unwind_Exception *);
 261 _Unwind_Reason_Code _Unwind_ForcedUnwind(_Unwind_Exception *, _Unwind_Stop_Fn,
 262                                          void *);
 263 void _Unwind_DeleteException(_Unwind_Exception *);
 264 void _Unwind_Resume(_Unwind_Exception *);
 265 _Unwind_Reason_Code _Unwind_Resume_or_Rethrow(_Unwind_Exception *);
 266
 267 #endif
 268
 269 _Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *);
 270
 271 /* setjmp(3)/longjmp(3) stuff */
 272 typedef struct SjLj_Function_Context *_Unwind_FunctionContext_t;
 273
 274 void _Unwind_SjLj_Register(_Unwind_FunctionContext_t);
 275 void _Unwind_SjLj_Unregister(_Unwind_FunctionContext_t);
 276 _Unwind_Reason_Code _Unwind_SjLj_RaiseException(_Unwind_Exception *);
 277 _Unwind_Reason_Code _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *,
 278                                               _Unwind_Stop_Fn, void *);
 279 void _Unwind_SjLj_Resume(_Unwind_Exception *);
 280 _Unwind_Reason_Code _Unwind_SjLj_Resume_or_Rethrow(_Unwind_Exception *);
 281
 282 void *_Unwind_FindEnclosingFunction(void *);
 283
 284 #ifdef __APPLE__
 285
 286 _Unwind_Ptr _Unwind_GetDataRelBase(struct _Unwind_Context *)
 287     __attribute__((__unavailable__));
 288 _Unwind_Ptr _Unwind_GetTextRelBase(struct _Unwind_Context *)
 289     __attribute__((__unavailable__));
 290
 291 /* Darwin-specific functions */
 292 void __register_frame(const void *);
 293 void __deregister_frame(const void *);
 294
 295 struct dwarf_eh_bases {
 296   uintptr_t tbase;
 297   uintptr_t dbase;
 298   uintptr_t func;
 299 };
 300 void *_Unwind_Find_FDE(const void *, struct dwarf_eh_bases *);
 301
 302 void __register_frame_info_bases(const void *, void *, void *, void *)
 303   __attribute__((__unavailable__));
 304 void __register_frame_info(const void *, void *) __attribute__((__unavailable__));
 305 void __register_frame_info_table_bases(const void *, void*, void *, void *)
 306   __attribute__((__unavailable__));
 307 void __register_frame_info_table(const void *, void *)
 308   __attribute__((__unavailable__));
 309 void __register_frame_table(const void *) __attribute__((__unavailable__));
 310 void __deregister_frame_info(const void *) __attribute__((__unavailable__));
 311 void __deregister_frame_info_bases(const void *)__attribute__((__unavailable__));
 312
 313 #else
 314
 315 _Unwind_Ptr _Unwind_GetDataRelBase(struct _Unwind_Context *);
 316 _Unwind_Ptr _Unwind_GetTextRelBase(struct _Unwind_Context *);
 317
 318 #endif
 319
 320
 321 #ifndef HIDE_EXPORTS
 322 #pragma GCC visibility pop
 323 #endif
 324
 325 #ifdef __cplusplus
 326 }
 327 #endif
 328
 329 #endif
 330
 331 #endif /* __CLANG_UNWIND_H */