1 //===------------------------------- unwind.h -----------------------------===//
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
8 // C++ ABI Level 1 ABI documented at:
9 // https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html
11 //===----------------------------------------------------------------------===//
16 #include <__libunwind_config.h>
21 #if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__) && defined(_WIN32)
26 #if defined(__APPLE__)
27 #define LIBUNWIND_UNAVAIL __attribute__ (( unavailable ))
29 #define LIBUNWIND_UNAVAIL
35 _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
36 _URC_FATAL_PHASE2_ERROR = 2,
37 _URC_FATAL_PHASE1_ERROR = 3,
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)
46 } _Unwind_Reason_Code;
50 _UA_CLEANUP_PHASE = 2,
51 _UA_HANDLER_FRAME = 4,
53 _UA_END_OF_STACK = 16 // gcc extension to C++ ABI
56 typedef struct _Unwind_Context _Unwind_Context; // opaque
58 #if defined(_LIBUNWIND_ARM_EHABI)
59 typedef uint32_t _Unwind_State;
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;
68 typedef uint32_t _Unwind_EHT_Header;
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.
74 struct _Unwind_Exception;
75 typedef struct _Unwind_Exception _Unwind_Exception;
76 typedef struct _Unwind_Exception _Unwind_Control_Block; /* Alias */
78 struct _Unwind_Exception {
79 uint64_t exception_class;
80 void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*);
82 /* Unwinder cache, private fields for the unwinder's use */
84 uint32_t reserved1; /* init reserved1 to 0, then don't touch */
91 /* Propagation barrier cache (valid after phase 1): */
94 uint32_t bitpattern[5];
97 /* Cleanup cache (preserved over cleanup): */
99 uint32_t bitpattern[4];
102 /* Pr cache (for pr's benefit): */
104 uint32_t fnstart; /* function start address */
105 _Unwind_EHT_Header* ehtp; /* pointer to EHT entry header word */
110 long long int :0; /* Enforce the 8-byte alignment */
111 } __attribute__((__aligned__(8)));
113 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
114 (_Unwind_State state,
115 _Unwind_Exception* exceptionObject,
116 struct _Unwind_Context* context);
118 typedef _Unwind_Reason_Code (*__personality_routine)
119 (_Unwind_State state,
120 _Unwind_Exception* exceptionObject,
121 struct _Unwind_Context* context);
123 struct _Unwind_Context; // opaque
124 struct _Unwind_Exception; // forward declaration
125 typedef struct _Unwind_Exception _Unwind_Exception;
127 struct _Unwind_Exception {
128 uint64_t exception_class;
129 void (*exception_cleanup)(_Unwind_Reason_Code reason,
130 _Unwind_Exception *exc);
131 #if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)
132 uintptr_t private_[6];
134 uintptr_t private_1; // non-zero means forced unwind
135 uintptr_t private_2; // holds sp that phase1 found for phase2 to use
137 #if __SIZEOF_POINTER__ == 4
138 // The implementation of _Unwind_Exception uses an attribute mode on the
139 // above fields which has the side effect of causing this whole struct to
140 // round up to 32 bytes in size (48 with SEH). To be more explicit, we add
141 // pad fields added for binary compatibility.
142 uint32_t reserved[3];
144 // The Itanium ABI requires that _Unwind_Exception objects are "double-word
145 // aligned". GCC has interpreted this to mean "use the maximum useful
146 // alignment for the target"; so do we.
147 } __attribute__((__aligned__));
149 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
151 _Unwind_Action actions,
152 uint64_t exceptionClass,
153 _Unwind_Exception* exceptionObject,
154 struct _Unwind_Context* context,
155 void* stop_parameter );
157 typedef _Unwind_Reason_Code (*__personality_routine)
159 _Unwind_Action actions,
160 uint64_t exceptionClass,
161 _Unwind_Exception* exceptionObject,
162 struct _Unwind_Context* context);
170 // The following are the base functions documented by the C++ ABI
172 #ifdef __USING_SJLJ_EXCEPTIONS__
173 extern _Unwind_Reason_Code
174 _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object);
175 extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object);
177 extern _Unwind_Reason_Code
178 _Unwind_RaiseException(_Unwind_Exception *exception_object);
179 extern void _Unwind_Resume(_Unwind_Exception *exception_object);
181 extern void _Unwind_DeleteException(_Unwind_Exception *exception_object);
183 #if defined(_LIBUNWIND_ARM_EHABI)
185 _UVRSC_CORE = 0, /* integer register */
186 _UVRSC_VFP = 1, /* vfp */
187 _UVRSC_WMMXD = 3, /* Intel WMMX data register */
188 _UVRSC_WMMXC = 4 /* Intel WMMX control register */
189 } _Unwind_VRS_RegClass;
197 } _Unwind_VRS_DataRepresentation;
201 _UVRSR_NOT_IMPLEMENTED = 1,
203 } _Unwind_VRS_Result;
205 extern void _Unwind_Complete(_Unwind_Exception* exception_object);
207 extern _Unwind_VRS_Result
208 _Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
209 uint32_t regno, _Unwind_VRS_DataRepresentation representation,
212 extern _Unwind_VRS_Result
213 _Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
214 uint32_t regno, _Unwind_VRS_DataRepresentation representation,
217 extern _Unwind_VRS_Result
218 _Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
219 uint32_t discriminator,
220 _Unwind_VRS_DataRepresentation representation);
223 #if !defined(_LIBUNWIND_ARM_EHABI)
225 extern uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index);
226 extern void _Unwind_SetGR(struct _Unwind_Context *context, int index,
227 uintptr_t new_value);
228 extern uintptr_t _Unwind_GetIP(struct _Unwind_Context *context);
229 extern void _Unwind_SetIP(struct _Unwind_Context *, uintptr_t new_value);
231 #else // defined(_LIBUNWIND_ARM_EHABI)
233 #if defined(_LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE)
234 #define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 extern
236 #define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 static __inline__
239 // These are de facto helper functions for ARM, which delegate the function
240 // calls to _Unwind_VRS_Get/Set(). These are not a part of ARM EHABI
241 // specification, thus these function MUST be inlined. Please don't replace
242 // these with the "extern" function declaration; otherwise, the program
243 // including this <unwind.h> header won't be ABI compatible and will result in
244 // link error when we are linking the program with libgcc.
246 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
247 uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) {
249 _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
253 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
254 void _Unwind_SetGR(struct _Unwind_Context *context, int index,
256 _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
259 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
260 uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
261 // remove the thumb-bit before returning
262 return _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1);
265 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
266 void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t value) {
267 uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
268 _Unwind_SetGR(context, 15, value | thumb_bit);
270 #endif // defined(_LIBUNWIND_ARM_EHABI)
272 extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context);
274 _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context);
275 #ifdef __USING_SJLJ_EXCEPTIONS__
276 extern _Unwind_Reason_Code
277 _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *exception_object,
278 _Unwind_Stop_Fn stop, void *stop_parameter);
280 extern _Unwind_Reason_Code
281 _Unwind_ForcedUnwind(_Unwind_Exception *exception_object,
282 _Unwind_Stop_Fn stop, void *stop_parameter);
285 #ifdef __USING_SJLJ_EXCEPTIONS__
286 typedef struct _Unwind_FunctionContext *_Unwind_FunctionContext_t;
287 extern void _Unwind_SjLj_Register(_Unwind_FunctionContext_t fc);
288 extern void _Unwind_SjLj_Unregister(_Unwind_FunctionContext_t fc);
292 // The following are semi-suppoted extensions to the C++ ABI
296 // called by __cxa_rethrow().
298 #ifdef __USING_SJLJ_EXCEPTIONS__
299 extern _Unwind_Reason_Code
300 _Unwind_SjLj_Resume_or_Rethrow(_Unwind_Exception *exception_object);
302 extern _Unwind_Reason_Code
303 _Unwind_Resume_or_Rethrow(_Unwind_Exception *exception_object);
306 // _Unwind_Backtrace() is a gcc extension that walks the stack and calls the
307 // _Unwind_Trace_Fn once per frame until it reaches the bottom of the stack
308 // or the _Unwind_Trace_Fn function returns something other than _URC_NO_REASON.
309 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *,
311 extern _Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *);
313 // _Unwind_GetCFA is a gcc extension that can be called from within a
314 // personality handler to get the CFA (stack pointer before call) of
316 extern uintptr_t _Unwind_GetCFA(struct _Unwind_Context *);
319 // _Unwind_GetIPInfo is a gcc extension that can be called from within a
320 // personality handler. Similar to _Unwind_GetIP() but also returns in
321 // *ipBefore a non-zero value if the instruction pointer is at or before the
322 // instruction causing the unwind. Normally, in a function call, the IP returned
323 // is the return address which is after the call instruction and may be past the
324 // end of the function containing the call instruction.
325 extern uintptr_t _Unwind_GetIPInfo(struct _Unwind_Context *context,
329 // __register_frame() is used with dynamically generated code to register the
330 // FDE for a generated (JIT) code. The FDE must use pc-rel addressing to point
331 // to its function and optional LSDA.
332 // __register_frame() has existed in all versions of Mac OS X, but in 10.4 and
333 // 10.5 it was buggy and did not actually register the FDE with the unwinder.
334 // In 10.6 and later it does register properly.
335 extern void __register_frame(const void *fde);
336 extern void __deregister_frame(const void *fde);
338 // _Unwind_Find_FDE() will locate the FDE if the pc is in some function that has
339 // an associated FDE. Note, Mac OS X 10.6 and later, introduces "compact unwind
340 // info" which the runtime uses in preference to DWARF unwind info. This
341 // function will only work if the target function has an FDE but no compact
343 struct dwarf_eh_bases {
348 extern const void *_Unwind_Find_FDE(const void *pc, struct dwarf_eh_bases *);
351 // This function attempts to find the start (address of first instruction) of
352 // a function given an address inside the function. It only works if the
353 // function has an FDE (DWARF unwind info).
354 // This function is unimplemented on Mac OS X 10.6 and later. Instead, use
355 // _Unwind_Find_FDE() and look at the dwarf_eh_bases.func result.
356 extern void *_Unwind_FindEnclosingFunction(void *pc);
358 // Mac OS X does not support text-rel and data-rel addressing so these functions
360 extern uintptr_t _Unwind_GetDataRelBase(struct _Unwind_Context *context)
362 extern uintptr_t _Unwind_GetTextRelBase(struct _Unwind_Context *context)
365 // Mac OS X 10.4 and 10.5 had implementations of these functions in
366 // libgcc_s.dylib, but they never worked.
367 /// These functions are no longer available on Mac OS X.
368 extern void __register_frame_info_bases(const void *fde, void *ob, void *tb,
369 void *db) LIBUNWIND_UNAVAIL;
370 extern void __register_frame_info(const void *fde, void *ob)
372 extern void __register_frame_info_table_bases(const void *fde, void *ob,
375 extern void __register_frame_info_table(const void *fde, void *ob)
377 extern void __register_frame_table(const void *fde)
379 extern void *__deregister_frame_info(const void *fde)
381 extern void *__deregister_frame_info_bases(const void *fde)
384 #if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)
386 typedef struct _EXCEPTION_RECORD EXCEPTION_RECORD;
387 typedef struct _CONTEXT CONTEXT;
388 typedef struct _DISPATCHER_CONTEXT DISPATCHER_CONTEXT;
389 #elif !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000
390 typedef struct _DISPATCHER_CONTEXT DISPATCHER_CONTEXT;
392 // This is the common wrapper for GCC-style personality functions with SEH.
393 extern EXCEPTION_DISPOSITION _GCC_specific_handler(EXCEPTION_RECORD *exc,
396 DISPATCHER_CONTEXT *disp,
397 __personality_routine pers);
404 #endif // __UNWIND_H__