1 //===------------------------------- unwind.h -----------------------------===// 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 // C++ ABI Level 1 ABI documented at: 9 // https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef __UNWIND_H__ 14 #define __UNWIND_H__ 15 16 #include <__libunwind_config.h> 17 18 #include <stdint.h> 19 #include <stddef.h> 20 21 #if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__) && defined(_WIN32) 22 #include <windows.h> 23 #include <ntverp.h> 24 #endif 25 26 #if defined(__APPLE__) 27 #define LIBUNWIND_UNAVAIL __attribute__ (( unavailable )) 28 #else 29 #define LIBUNWIND_UNAVAIL 30 #endif 31 32 typedef enum { 33 _URC_NO_REASON = 0, 34 _URC_OK = 0, 35 _URC_FOREIGN_EXCEPTION_CAUGHT = 1, 36 _URC_FATAL_PHASE2_ERROR = 2, 37 _URC_FATAL_PHASE1_ERROR = 3, 38 _URC_NORMAL_STOP = 4, 39 _URC_END_OF_STACK = 5, 40 _URC_HANDLER_FOUND = 6, 41 _URC_INSTALL_CONTEXT = 7, 42 _URC_CONTINUE_UNWIND = 8, 43 #if defined(_LIBUNWIND_ARM_EHABI) 44 _URC_FAILURE = 9 45 #endif 46 } _Unwind_Reason_Code; 47 48 typedef enum { 49 _UA_SEARCH_PHASE = 1, 50 _UA_CLEANUP_PHASE = 2, 51 _UA_HANDLER_FRAME = 4, 52 _UA_FORCE_UNWIND = 8, 53 _UA_END_OF_STACK = 16 // gcc extension to C++ ABI 54 } _Unwind_Action; 55 56 typedef struct _Unwind_Context _Unwind_Context; // opaque 57 58 #if defined(_LIBUNWIND_ARM_EHABI) 59 typedef uint32_t _Unwind_State; 60 61 static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME = 0; 62 static const _Unwind_State _US_UNWIND_FRAME_STARTING = 1; 63 static const _Unwind_State _US_UNWIND_FRAME_RESUME = 2; 64 static const _Unwind_State _US_ACTION_MASK = 3; 65 /* Undocumented flag for force unwinding. */ 66 static const _Unwind_State _US_FORCE_UNWIND = 8; 67 68 typedef uint32_t _Unwind_EHT_Header; 69 /* 70 * gcc_personality_v0 references 'struct _Unwind_Exception' all over the place. 71 * Nothing in libunwind cares about 'struct _Unwind_Control_Block,' so make it 72 * the alias of struct _Unwind_Exception, instead of the other way around. 73 */ 74 struct _Unwind_Exception; 75 typedef struct _Unwind_Exception _Unwind_Exception; 76 typedef struct _Unwind_Exception _Unwind_Control_Block; /* Alias */ 77 78 struct _Unwind_Exception { 79 uint64_t exception_class; 80 void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*); 81 82 /* Unwinder cache, private fields for the unwinder's use */ 83 struct { 84 uint32_t reserved1; /* init reserved1 to 0, then don't touch */ 85 uint32_t reserved2; 86 uint32_t reserved3; 87 uint32_t reserved4; 88 uint32_t reserved5; 89 } unwinder_cache; 90 91 /* Propagation barrier cache (valid after phase 1): */ 92 struct { 93 uint32_t sp; 94 uint32_t bitpattern[5]; 95 } barrier_cache; 96 97 /* Cleanup cache (preserved over cleanup): */ 98 struct { 99 uint32_t bitpattern[4]; 100 } cleanup_cache; 101 102 /* Pr cache (for pr's benefit): */ 103 struct { 104 uint32_t fnstart; /* function start address */ 105 _Unwind_EHT_Header* ehtp; /* pointer to EHT entry header word */ 106 uint32_t additional; 107 uint32_t reserved1; 108 } pr_cache; 109 110 long long int :0; /* Enforce the 8-byte alignment */ 111 } __attribute__((__aligned__(8))); 112 113 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn) 114 (_Unwind_State state, 115 _Unwind_Exception* exceptionObject, 116 struct _Unwind_Context* context); 117 118 typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)( 119 _Unwind_State state, _Unwind_Exception *exceptionObject, 120 struct _Unwind_Context *context); 121 #else 122 struct _Unwind_Context; // opaque 123 struct _Unwind_Exception; // forward declaration 124 typedef struct _Unwind_Exception _Unwind_Exception; 125 126 struct _Unwind_Exception { 127 uint64_t exception_class; 128 void (*exception_cleanup)(_Unwind_Reason_Code reason, 129 _Unwind_Exception *exc); 130 #if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__) 131 uintptr_t private_[6]; 132 #else 133 uintptr_t private_1; // non-zero means forced unwind 134 uintptr_t private_2; // holds sp that phase1 found for phase2 to use 135 #endif 136 #if __SIZEOF_POINTER__ == 4 137 // The implementation of _Unwind_Exception uses an attribute mode on the 138 // above fields which has the side effect of causing this whole struct to 139 // round up to 32 bytes in size (48 with SEH). To be more explicit, we add 140 // pad fields added for binary compatibility. 141 uint32_t reserved[3]; 142 #endif 143 // The Itanium ABI requires that _Unwind_Exception objects are "double-word 144 // aligned". GCC has interpreted this to mean "use the maximum useful 145 // alignment for the target"; so do we. 146 } __attribute__((__aligned__)); 147 148 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn) 149 (int version, 150 _Unwind_Action actions, 151 uint64_t exceptionClass, 152 _Unwind_Exception* exceptionObject, 153 struct _Unwind_Context* context, 154 void* stop_parameter ); 155 156 typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)( 157 int version, _Unwind_Action actions, uint64_t exceptionClass, 158 _Unwind_Exception *exceptionObject, struct _Unwind_Context *context); 159 #endif 160 161 #ifdef __cplusplus 162 extern "C" { 163 #endif 164 165 // 166 // The following are the base functions documented by the C++ ABI 167 // 168 #ifdef __USING_SJLJ_EXCEPTIONS__ 169 extern _Unwind_Reason_Code 170 _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object); 171 extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object); 172 #else 173 extern _Unwind_Reason_Code 174 _Unwind_RaiseException(_Unwind_Exception *exception_object); 175 extern void _Unwind_Resume(_Unwind_Exception *exception_object); 176 #endif 177 extern void _Unwind_DeleteException(_Unwind_Exception *exception_object); 178 179 #if defined(_LIBUNWIND_ARM_EHABI) 180 typedef enum { 181 _UVRSC_CORE = 0, /* integer register */ 182 _UVRSC_VFP = 1, /* vfp */ 183 _UVRSC_WMMXD = 3, /* Intel WMMX data register */ 184 _UVRSC_WMMXC = 4 /* Intel WMMX control register */ 185 } _Unwind_VRS_RegClass; 186 187 typedef enum { 188 _UVRSD_UINT32 = 0, 189 _UVRSD_VFPX = 1, 190 _UVRSD_UINT64 = 3, 191 _UVRSD_FLOAT = 4, 192 _UVRSD_DOUBLE = 5 193 } _Unwind_VRS_DataRepresentation; 194 195 typedef enum { 196 _UVRSR_OK = 0, 197 _UVRSR_NOT_IMPLEMENTED = 1, 198 _UVRSR_FAILED = 2 199 } _Unwind_VRS_Result; 200 201 extern void _Unwind_Complete(_Unwind_Exception* exception_object); 202 203 extern _Unwind_VRS_Result 204 _Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass, 205 uint32_t regno, _Unwind_VRS_DataRepresentation representation, 206 void *valuep); 207 208 extern _Unwind_VRS_Result 209 _Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass, 210 uint32_t regno, _Unwind_VRS_DataRepresentation representation, 211 void *valuep); 212 213 extern _Unwind_VRS_Result 214 _Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass, 215 uint32_t discriminator, 216 _Unwind_VRS_DataRepresentation representation); 217 #endif 218 219 #if !defined(_LIBUNWIND_ARM_EHABI) 220 221 extern uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index); 222 extern void _Unwind_SetGR(struct _Unwind_Context *context, int index, 223 uintptr_t new_value); 224 extern uintptr_t _Unwind_GetIP(struct _Unwind_Context *context); 225 extern void _Unwind_SetIP(struct _Unwind_Context *, uintptr_t new_value); 226 227 #else // defined(_LIBUNWIND_ARM_EHABI) 228 229 #if defined(_LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE) 230 #define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 extern 231 #else 232 #define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 static __inline__ 233 #endif 234 235 // These are de facto helper functions for ARM, which delegate the function 236 // calls to _Unwind_VRS_Get/Set(). These are not a part of ARM EHABI 237 // specification, thus these function MUST be inlined. Please don't replace 238 // these with the "extern" function declaration; otherwise, the program 239 // including this <unwind.h> header won't be ABI compatible and will result in 240 // link error when we are linking the program with libgcc. 241 242 _LIBUNWIND_EXPORT_UNWIND_LEVEL1 243 uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) { 244 uintptr_t value = 0; 245 _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value); 246 return value; 247 } 248 249 _LIBUNWIND_EXPORT_UNWIND_LEVEL1 250 void _Unwind_SetGR(struct _Unwind_Context *context, int index, 251 uintptr_t value) { 252 _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value); 253 } 254 255 _LIBUNWIND_EXPORT_UNWIND_LEVEL1 256 uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) { 257 // remove the thumb-bit before returning 258 return _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1); 259 } 260 261 _LIBUNWIND_EXPORT_UNWIND_LEVEL1 262 void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t value) { 263 uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1); 264 _Unwind_SetGR(context, 15, value | thumb_bit); 265 } 266 #endif // defined(_LIBUNWIND_ARM_EHABI) 267 268 extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context); 269 extern uintptr_t 270 _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context); 271 #ifdef __USING_SJLJ_EXCEPTIONS__ 272 extern _Unwind_Reason_Code 273 _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *exception_object, 274 _Unwind_Stop_Fn stop, void *stop_parameter); 275 #else 276 extern _Unwind_Reason_Code 277 _Unwind_ForcedUnwind(_Unwind_Exception *exception_object, 278 _Unwind_Stop_Fn stop, void *stop_parameter); 279 #endif 280 281 #ifdef __USING_SJLJ_EXCEPTIONS__ 282 typedef struct _Unwind_FunctionContext *_Unwind_FunctionContext_t; 283 extern void _Unwind_SjLj_Register(_Unwind_FunctionContext_t fc); 284 extern void _Unwind_SjLj_Unregister(_Unwind_FunctionContext_t fc); 285 #endif 286 287 // 288 // The following are semi-suppoted extensions to the C++ ABI 289 // 290 291 // 292 // called by __cxa_rethrow(). 293 // 294 #ifdef __USING_SJLJ_EXCEPTIONS__ 295 extern _Unwind_Reason_Code 296 _Unwind_SjLj_Resume_or_Rethrow(_Unwind_Exception *exception_object); 297 #else 298 extern _Unwind_Reason_Code 299 _Unwind_Resume_or_Rethrow(_Unwind_Exception *exception_object); 300 #endif 301 302 // _Unwind_Backtrace() is a gcc extension that walks the stack and calls the 303 // _Unwind_Trace_Fn once per frame until it reaches the bottom of the stack 304 // or the _Unwind_Trace_Fn function returns something other than _URC_NO_REASON. 305 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *, 306 void *); 307 extern _Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *); 308 309 // _Unwind_GetCFA is a gcc extension that can be called from within a 310 // personality handler to get the CFA (stack pointer before call) of 311 // current frame. 312 extern uintptr_t _Unwind_GetCFA(struct _Unwind_Context *); 313 314 315 // _Unwind_GetIPInfo is a gcc extension that can be called from within a 316 // personality handler. Similar to _Unwind_GetIP() but also returns in 317 // *ipBefore a non-zero value if the instruction pointer is at or before the 318 // instruction causing the unwind. Normally, in a function call, the IP returned 319 // is the return address which is after the call instruction and may be past the 320 // end of the function containing the call instruction. 321 extern uintptr_t _Unwind_GetIPInfo(struct _Unwind_Context *context, 322 int *ipBefore); 323 324 325 // __register_frame() is used with dynamically generated code to register the 326 // FDE for a generated (JIT) code. The FDE must use pc-rel addressing to point 327 // to its function and optional LSDA. 328 // __register_frame() has existed in all versions of Mac OS X, but in 10.4 and 329 // 10.5 it was buggy and did not actually register the FDE with the unwinder. 330 // In 10.6 and later it does register properly. 331 extern void __register_frame(const void *fde); 332 extern void __deregister_frame(const void *fde); 333 334 // _Unwind_Find_FDE() will locate the FDE if the pc is in some function that has 335 // an associated FDE. Note, Mac OS X 10.6 and later, introduces "compact unwind 336 // info" which the runtime uses in preference to DWARF unwind info. This 337 // function will only work if the target function has an FDE but no compact 338 // unwind info. 339 struct dwarf_eh_bases { 340 uintptr_t tbase; 341 uintptr_t dbase; 342 uintptr_t func; 343 }; 344 extern const void *_Unwind_Find_FDE(const void *pc, struct dwarf_eh_bases *); 345 346 347 // This function attempts to find the start (address of first instruction) of 348 // a function given an address inside the function. It only works if the 349 // function has an FDE (DWARF unwind info). 350 // This function is unimplemented on Mac OS X 10.6 and later. Instead, use 351 // _Unwind_Find_FDE() and look at the dwarf_eh_bases.func result. 352 extern void *_Unwind_FindEnclosingFunction(void *pc); 353 354 // Mac OS X does not support text-rel and data-rel addressing so these functions 355 // are unimplemented 356 extern uintptr_t _Unwind_GetDataRelBase(struct _Unwind_Context *context) 357 LIBUNWIND_UNAVAIL; 358 extern uintptr_t _Unwind_GetTextRelBase(struct _Unwind_Context *context) 359 LIBUNWIND_UNAVAIL; 360 361 // Mac OS X 10.4 and 10.5 had implementations of these functions in 362 // libgcc_s.dylib, but they never worked. 363 /// These functions are no longer available on Mac OS X. 364 extern void __register_frame_info_bases(const void *fde, void *ob, void *tb, 365 void *db) LIBUNWIND_UNAVAIL; 366 extern void __register_frame_info(const void *fde, void *ob) 367 LIBUNWIND_UNAVAIL; 368 extern void __register_frame_info_table_bases(const void *fde, void *ob, 369 void *tb, void *db) 370 LIBUNWIND_UNAVAIL; 371 extern void __register_frame_info_table(const void *fde, void *ob) 372 LIBUNWIND_UNAVAIL; 373 extern void __register_frame_table(const void *fde) 374 LIBUNWIND_UNAVAIL; 375 extern void *__deregister_frame_info(const void *fde) 376 LIBUNWIND_UNAVAIL; 377 extern void *__deregister_frame_info_bases(const void *fde) 378 LIBUNWIND_UNAVAIL; 379 380 #if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__) 381 #ifndef _WIN32 382 typedef struct _EXCEPTION_RECORD EXCEPTION_RECORD; 383 typedef struct _CONTEXT CONTEXT; 384 typedef struct _DISPATCHER_CONTEXT DISPATCHER_CONTEXT; 385 #elif !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000 386 typedef struct _DISPATCHER_CONTEXT DISPATCHER_CONTEXT; 387 #endif 388 // This is the common wrapper for GCC-style personality functions with SEH. 389 extern EXCEPTION_DISPOSITION _GCC_specific_handler(EXCEPTION_RECORD *exc, 390 void *frame, CONTEXT *ctx, 391 DISPATCHER_CONTEXT *disp, 392 _Unwind_Personality_Fn pers); 393 #endif 394 395 #ifdef __cplusplus 396 } 397 #endif 398 399 #endif // __UNWIND_H__ 400