1//===------------------------------- unwind.h -----------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//
9// C++ ABI Level 1 ABI documented at:
10//   http://mentorembedded.github.io/cxx-abi/abi-eh.html
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef __UNWIND_H__
15#define __UNWIND_H__
16
17#include <stdint.h>
18#include <stddef.h>
19
20#if defined(__APPLE__)
21#define LIBUNWIND_UNAVAIL __attribute__ (( unavailable ))
22#else
23#define LIBUNWIND_UNAVAIL
24#endif
25
26// FIXME: This is also in cxxabi.h and libunwind.h, can we consolidate?
27#if !defined(__USING_SJLJ_EXCEPTIONS__) && defined(__arm__) && \
28    !defined(__ARM_DWARF_EH__) && !defined(__APPLE__)
29#define LIBCXXABI_ARM_EHABI 1
30#else
31#define LIBCXXABI_ARM_EHABI 0
32#endif
33
34typedef enum {
35  _URC_NO_REASON = 0,
36  _URC_OK = 0,
37  _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
38  _URC_FATAL_PHASE2_ERROR = 2,
39  _URC_FATAL_PHASE1_ERROR = 3,
40  _URC_NORMAL_STOP = 4,
41  _URC_END_OF_STACK = 5,
42  _URC_HANDLER_FOUND = 6,
43  _URC_INSTALL_CONTEXT = 7,
44  _URC_CONTINUE_UNWIND = 8,
45#if LIBCXXABI_ARM_EHABI
46  _URC_FAILURE = 9
47#endif
48} _Unwind_Reason_Code;
49
50typedef enum {
51  _UA_SEARCH_PHASE = 1,
52  _UA_CLEANUP_PHASE = 2,
53  _UA_HANDLER_FRAME = 4,
54  _UA_FORCE_UNWIND = 8,
55  _UA_END_OF_STACK = 16 // gcc extension to C++ ABI
56} _Unwind_Action;
57
58typedef struct _Unwind_Context _Unwind_Context;   // opaque
59
60#if LIBCXXABI_ARM_EHABI
61typedef uint32_t _Unwind_State;
62
63static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME   = 0;
64static const _Unwind_State _US_UNWIND_FRAME_STARTING  = 1;
65static const _Unwind_State _US_UNWIND_FRAME_RESUME    = 2;
66
67typedef uint32_t _Unwind_EHT_Header;
68
69struct _Unwind_Control_Block;
70typedef struct _Unwind_Control_Block _Unwind_Control_Block;
71typedef struct _Unwind_Control_Block _Unwind_Exception; /* Alias */
72
73struct _Unwind_Control_Block {
74  uint64_t exception_class;
75  void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*);
76
77  /* Unwinder cache, private fields for the unwinder's use */
78  struct {
79    uint32_t reserved1; /* init reserved1 to 0, then don't touch */
80    uint32_t reserved2;
81    uint32_t reserved3;
82    uint32_t reserved4;
83    uint32_t reserved5;
84  } unwinder_cache;
85
86  /* Propagation barrier cache (valid after phase 1): */
87  struct {
88    uint32_t sp;
89    uint32_t bitpattern[5];
90  } barrier_cache;
91
92  /* Cleanup cache (preserved over cleanup): */
93  struct {
94    uint32_t bitpattern[4];
95  } cleanup_cache;
96
97  /* Pr cache (for pr's benefit): */
98  struct {
99    uint32_t fnstart; /* function start address */
100    _Unwind_EHT_Header* ehtp; /* pointer to EHT entry header word */
101    uint32_t additional;
102    uint32_t reserved1;
103  } pr_cache;
104
105  long long int :0; /* Enforce the 8-byte alignment */
106};
107
108typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
109      (_Unwind_State state,
110       _Unwind_Exception* exceptionObject,
111       struct _Unwind_Context* context);
112
113typedef _Unwind_Reason_Code (*__personality_routine)
114      (_Unwind_State state,
115       _Unwind_Exception* exceptionObject,
116       struct _Unwind_Context* context);
117#else
118struct _Unwind_Context;   // opaque
119struct _Unwind_Exception; // forward declaration
120typedef struct _Unwind_Exception _Unwind_Exception;
121
122struct _Unwind_Exception {
123  uint64_t exception_class;
124  void (*exception_cleanup)(_Unwind_Reason_Code reason,
125                            _Unwind_Exception *exc);
126  uintptr_t private_1; // non-zero means forced unwind
127  uintptr_t private_2; // holds sp that phase1 found for phase2 to use
128#if !__LP64__
129  // The gcc implementation of _Unwind_Exception used attribute mode on the
130  // above fields which had the side effect of causing this whole struct to
131  // round up to 32 bytes in size. To be more explicit, we add pad fields
132  // added for binary compatibility.
133  uint32_t reserved[3];
134#endif
135};
136
137typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
138    (int version,
139     _Unwind_Action actions,
140     uint64_t exceptionClass,
141     _Unwind_Exception* exceptionObject,
142     struct _Unwind_Context* context,
143     void* stop_parameter );
144
145typedef _Unwind_Reason_Code (*__personality_routine)
146      (int version,
147       _Unwind_Action actions,
148       uint64_t exceptionClass,
149       _Unwind_Exception* exceptionObject,
150       struct _Unwind_Context* context);
151#endif
152
153#ifdef __cplusplus
154extern "C" {
155#endif
156
157//
158// The following are the base functions documented by the C++ ABI
159//
160#if __USING_SJLJ_EXCEPTIONS__
161extern _Unwind_Reason_Code
162    _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object);
163extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object);
164#else
165extern _Unwind_Reason_Code
166    _Unwind_RaiseException(_Unwind_Exception *exception_object);
167extern void _Unwind_Resume(_Unwind_Exception *exception_object);
168#endif
169extern void _Unwind_DeleteException(_Unwind_Exception *exception_object);
170
171#if LIBCXXABI_ARM_EHABI
172typedef enum {
173  _UVRSC_CORE = 0, /* integer register */
174  _UVRSC_VFP = 1, /* vfp */
175  _UVRSC_WMMXD = 3, /* Intel WMMX data register */
176  _UVRSC_WMMXC = 4 /* Intel WMMX control register */
177} _Unwind_VRS_RegClass;
178
179typedef enum {
180  _UVRSD_UINT32 = 0,
181  _UVRSD_VFPX = 1,
182  _UVRSD_UINT64 = 3,
183  _UVRSD_FLOAT = 4,
184  _UVRSD_DOUBLE = 5
185} _Unwind_VRS_DataRepresentation;
186
187typedef enum {
188  _UVRSR_OK = 0,
189  _UVRSR_NOT_IMPLEMENTED = 1,
190  _UVRSR_FAILED = 2
191} _Unwind_VRS_Result;
192
193extern void _Unwind_Complete(_Unwind_Exception* exception_object);
194
195extern _Unwind_VRS_Result
196_Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
197                uint32_t regno, _Unwind_VRS_DataRepresentation representation,
198                void *valuep);
199
200extern _Unwind_VRS_Result
201_Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
202                uint32_t regno, _Unwind_VRS_DataRepresentation representation,
203                void *valuep);
204
205extern _Unwind_VRS_Result
206_Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
207                uint32_t discriminator,
208                _Unwind_VRS_DataRepresentation representation);
209
210static inline uintptr_t _Unwind_GetGR(struct _Unwind_Context* context,
211                                      int index) {
212  uintptr_t value = 0;
213  _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
214  return value;
215}
216
217static inline void _Unwind_SetGR(struct _Unwind_Context* context, int index,
218                                 uintptr_t new_value) {
219  _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index,
220                  _UVRSD_UINT32, &new_value);
221}
222
223static inline uintptr_t _Unwind_GetIP(struct _Unwind_Context* context) {
224  // remove the thumb-bit before returning
225  return (_Unwind_GetGR(context, 15) & (~(uintptr_t)0x1));
226}
227
228static inline void _Unwind_SetIP(struct _Unwind_Context* context,
229                                 uintptr_t new_value) {
230  uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
231  _Unwind_SetGR(context, 15, new_value | thumb_bit);
232}
233#else
234extern uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index);
235extern void _Unwind_SetGR(struct _Unwind_Context *context, int index,
236                          uintptr_t new_value);
237extern uintptr_t _Unwind_GetIP(struct _Unwind_Context *context);
238extern void _Unwind_SetIP(struct _Unwind_Context *, uintptr_t new_value);
239#endif
240
241extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context);
242extern uintptr_t
243    _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context);
244#if __USING_SJLJ_EXCEPTIONS__
245extern _Unwind_Reason_Code
246    _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *exception_object,
247                              _Unwind_Stop_Fn stop, void *stop_parameter);
248#else
249extern _Unwind_Reason_Code
250    _Unwind_ForcedUnwind(_Unwind_Exception *exception_object,
251                         _Unwind_Stop_Fn stop, void *stop_parameter);
252#endif
253
254#if __USING_SJLJ_EXCEPTIONS__
255typedef struct _Unwind_FunctionContext *_Unwind_FunctionContext_t;
256extern void _Unwind_SjLj_Register(_Unwind_FunctionContext_t fc);
257extern void _Unwind_SjLj_Unregister(_Unwind_FunctionContext_t fc);
258#endif
259
260//
261// The following are semi-suppoted extensions to the C++ ABI
262//
263
264//
265//  called by __cxa_rethrow().
266//
267#if __USING_SJLJ_EXCEPTIONS__
268extern _Unwind_Reason_Code
269    _Unwind_SjLj_Resume_or_Rethrow(_Unwind_Exception *exception_object);
270#else
271extern _Unwind_Reason_Code
272    _Unwind_Resume_or_Rethrow(_Unwind_Exception *exception_object);
273#endif
274
275// _Unwind_Backtrace() is a gcc extension that walks the stack and calls the
276// _Unwind_Trace_Fn once per frame until it reaches the bottom of the stack
277// or the _Unwind_Trace_Fn function returns something other than _URC_NO_REASON.
278typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *,
279                                                void *);
280extern _Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *);
281
282// _Unwind_GetCFA is a gcc extension that can be called from within a
283// personality handler to get the CFA (stack pointer before call) of
284// current frame.
285extern uintptr_t _Unwind_GetCFA(struct _Unwind_Context *);
286
287
288// _Unwind_GetIPInfo is a gcc extension that can be called from within a
289// personality handler.  Similar to _Unwind_GetIP() but also returns in
290// *ipBefore a non-zero value if the instruction pointer is at or before the
291// instruction causing the unwind. Normally, in a function call, the IP returned
292// is the return address which is after the call instruction and may be past the
293// end of the function containing the call instruction.
294extern uintptr_t _Unwind_GetIPInfo(struct _Unwind_Context *context,
295                                   int *ipBefore);
296
297
298// __register_frame() is used with dynamically generated code to register the
299// FDE for a generated (JIT) code.  The FDE must use pc-rel addressing to point
300// to its function and optional LSDA.
301// __register_frame() has existed in all versions of Mac OS X, but in 10.4 and
302// 10.5 it was buggy and did not actually register the FDE with the unwinder.
303// In 10.6 and later it does register properly.
304extern void __register_frame(const void *fde);
305extern void __deregister_frame(const void *fde);
306
307// _Unwind_Find_FDE() will locate the FDE if the pc is in some function that has
308// an associated FDE. Note, Mac OS X 10.6 and later, introduces "compact unwind
309// info" which the runtime uses in preference to dwarf unwind info.  This
310// function will only work if the target function has an FDE but no compact
311// unwind info.
312struct dwarf_eh_bases {
313  uintptr_t tbase;
314  uintptr_t dbase;
315  uintptr_t func;
316};
317extern const void *_Unwind_Find_FDE(const void *pc, struct dwarf_eh_bases *);
318
319
320// This function attempts to find the start (address of first instruction) of
321// a function given an address inside the function.  It only works if the
322// function has an FDE (dwarf unwind info).
323// This function is unimplemented on Mac OS X 10.6 and later.  Instead, use
324// _Unwind_Find_FDE() and look at the dwarf_eh_bases.func result.
325extern void *_Unwind_FindEnclosingFunction(void *pc);
326
327// Mac OS X does not support text-rel and data-rel addressing so these functions
328// are unimplemented
329extern uintptr_t _Unwind_GetDataRelBase(struct _Unwind_Context *context)
330    LIBUNWIND_UNAVAIL;
331extern uintptr_t _Unwind_GetTextRelBase(struct _Unwind_Context *context)
332    LIBUNWIND_UNAVAIL;
333
334// Mac OS X 10.4 and 10.5 had implementations of these functions in
335// libgcc_s.dylib, but they never worked.
336/// These functions are no longer available on Mac OS X.
337extern void __register_frame_info_bases(const void *fde, void *ob, void *tb,
338                                        void *db) LIBUNWIND_UNAVAIL;
339extern void __register_frame_info(const void *fde, void *ob)
340    LIBUNWIND_UNAVAIL;
341extern void __register_frame_info_table_bases(const void *fde, void *ob,
342                                              void *tb, void *db)
343    LIBUNWIND_UNAVAIL;
344extern void __register_frame_info_table(const void *fde, void *ob)
345    LIBUNWIND_UNAVAIL;
346extern void __register_frame_table(const void *fde)
347    LIBUNWIND_UNAVAIL;
348extern void *__deregister_frame_info(const void *fde)
349    LIBUNWIND_UNAVAIL;
350extern void *__deregister_frame_info_bases(const void *fde)
351    LIBUNWIND_UNAVAIL;
352
353#ifdef __cplusplus
354}
355#endif
356
357#endif // __UNWIND_H__
358