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