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 32typedef 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 48typedef 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 56typedef struct _Unwind_Context _Unwind_Context; // opaque 57 58#if defined(_LIBUNWIND_ARM_EHABI) 59typedef uint32_t _Unwind_State; 60 61static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME = 0; 62static const _Unwind_State _US_UNWIND_FRAME_STARTING = 1; 63static const _Unwind_State _US_UNWIND_FRAME_RESUME = 2; 64static const _Unwind_State _US_ACTION_MASK = 3; 65/* Undocumented flag for force unwinding. */ 66static const _Unwind_State _US_FORCE_UNWIND = 8; 67 68typedef 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 */ 74struct _Unwind_Exception; 75typedef struct _Unwind_Exception _Unwind_Exception; 76typedef struct _Unwind_Exception _Unwind_Control_Block; /* Alias */ 77 78struct _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 113typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn) 114 (_Unwind_State state, 115 _Unwind_Exception* exceptionObject, 116 struct _Unwind_Context* context); 117 118typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)( 119 _Unwind_State state, _Unwind_Exception *exceptionObject, 120 struct _Unwind_Context *context); 121#else 122struct _Unwind_Context; // opaque 123struct _Unwind_Exception; // forward declaration 124typedef struct _Unwind_Exception _Unwind_Exception; 125 126struct _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 148typedef _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 156typedef _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 162extern "C" { 163#endif 164 165// 166// The following are the base functions documented by the C++ ABI 167// 168#ifdef __USING_SJLJ_EXCEPTIONS__ 169extern _Unwind_Reason_Code 170 _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object); 171extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object); 172#else 173extern _Unwind_Reason_Code 174 _Unwind_RaiseException(_Unwind_Exception *exception_object); 175extern void _Unwind_Resume(_Unwind_Exception *exception_object); 176#endif 177extern void _Unwind_DeleteException(_Unwind_Exception *exception_object); 178 179#if defined(_LIBUNWIND_ARM_EHABI) 180typedef 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 187typedef 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 195typedef enum { 196 _UVRSR_OK = 0, 197 _UVRSR_NOT_IMPLEMENTED = 1, 198 _UVRSR_FAILED = 2 199} _Unwind_VRS_Result; 200 201extern void _Unwind_Complete(_Unwind_Exception* exception_object); 202 203extern _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 208extern _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 213extern _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 221extern uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index); 222extern void _Unwind_SetGR(struct _Unwind_Context *context, int index, 223 uintptr_t new_value); 224extern uintptr_t _Unwind_GetIP(struct _Unwind_Context *context); 225extern 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 243uintptr_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 250void _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 256uintptr_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 262void _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 268extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context); 269extern uintptr_t 270 _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context); 271#ifdef __USING_SJLJ_EXCEPTIONS__ 272extern _Unwind_Reason_Code 273 _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *exception_object, 274 _Unwind_Stop_Fn stop, void *stop_parameter); 275#else 276extern _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__ 282typedef struct _Unwind_FunctionContext *_Unwind_FunctionContext_t; 283extern void _Unwind_SjLj_Register(_Unwind_FunctionContext_t fc); 284extern 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__ 295extern _Unwind_Reason_Code 296 _Unwind_SjLj_Resume_or_Rethrow(_Unwind_Exception *exception_object); 297#else 298extern _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. 305typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *, 306 void *); 307extern _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. 312extern 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. 321extern 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. 331extern void __register_frame(const void *fde); 332extern 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. 339struct dwarf_eh_bases { 340 uintptr_t tbase; 341 uintptr_t dbase; 342 uintptr_t func; 343}; 344extern 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. 352extern 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 356extern uintptr_t _Unwind_GetDataRelBase(struct _Unwind_Context *context) 357 LIBUNWIND_UNAVAIL; 358extern 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. 364extern void __register_frame_info_bases(const void *fde, void *ob, void *tb, 365 void *db) LIBUNWIND_UNAVAIL; 366extern void __register_frame_info(const void *fde, void *ob) 367 LIBUNWIND_UNAVAIL; 368extern void __register_frame_info_table_bases(const void *fde, void *ob, 369 void *tb, void *db) 370 LIBUNWIND_UNAVAIL; 371extern void __register_frame_info_table(const void *fde, void *ob) 372 LIBUNWIND_UNAVAIL; 373extern void __register_frame_table(const void *fde) 374 LIBUNWIND_UNAVAIL; 375extern void *__deregister_frame_info(const void *fde) 376 LIBUNWIND_UNAVAIL; 377extern void *__deregister_frame_info_bases(const void *fde) 378 LIBUNWIND_UNAVAIL; 379 380#if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__) 381#ifndef _WIN32 382typedef struct _EXCEPTION_RECORD EXCEPTION_RECORD; 383typedef struct _CONTEXT CONTEXT; 384typedef struct _DISPATCHER_CONTEXT DISPATCHER_CONTEXT; 385#elif !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000 386typedef struct _DISPATCHER_CONTEXT DISPATCHER_CONTEXT; 387#endif 388// This is the common wrapper for GCC-style personality functions with SEH. 389extern 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