unwind.h revision e085735cbedc82b1064f05ff796e32e906a95036 
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
26typedef enum {
27  _URC_NO_REASON = 0,
28  _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
29  _URC_FATAL_PHASE2_ERROR = 2,
30  _URC_FATAL_PHASE1_ERROR = 3,
31  _URC_NORMAL_STOP = 4,
32  _URC_END_OF_STACK = 5,
33  _URC_HANDLER_FOUND = 6,
34  _URC_INSTALL_CONTEXT = 7,
35  _URC_CONTINUE_UNWIND = 8
36} _Unwind_Reason_Code;
37
38typedef enum {
39  _UA_SEARCH_PHASE = 1,
40  _UA_CLEANUP_PHASE = 2,
41  _UA_HANDLER_FRAME = 4,
42  _UA_FORCE_UNWIND = 8,
43  _UA_END_OF_STACK = 16 // gcc extension to C++ ABI
44} _Unwind_Action;
45
46struct _Unwind_Context;   // opaque
47struct _Unwind_Exception; // forward declaration
48
49struct _Unwind_Exception {
50  uint64_t exception_class;
51  void (*exception_cleanup)(_Unwind_Reason_Code reason,
52                            struct _Unwind_Exception *exc);
53  uintptr_t private_1; // non-zero means forced unwind
54  uintptr_t private_2; // holds sp that phase1 found for phase2 to use
55#if !__LP64__
56  // The gcc implementation of _Unwind_Exception used attribute mode on the
57  // above fields which had the side effect of causing this whole struct to
58  // round up to 32 bytes in size. To be more explicit, we add pad fields
59  // added for binary compatibility.
60  uint32_t reserved[3];
61#endif
62};
63
64typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
65    (int version,
66     _Unwind_Action actions,
67     uint64_t exceptionClass,
68     struct _Unwind_Exception* exceptionObject,
69     struct _Unwind_Context* context,
70     void* stop_parameter );
71
72typedef _Unwind_Reason_Code (*__personality_routine)
73      (int version,
74       _Unwind_Action actions,
75       uint64_t exceptionClass,
76       struct _Unwind_Exception* exceptionObject,
77       struct _Unwind_Context* context);
78
79#ifdef __cplusplus
80extern "C" {
81#endif
82
83//
84// The following are the base functions documented by the C++ ABI
85//
86#if _LIBUNWIND_BUILD_SJLJ_APIS
87extern _Unwind_Reason_Code
88    _Unwind_SjLj_RaiseException(struct _Unwind_Exception *exception_object);
89extern void _Unwind_SjLj_Resume(struct _Unwind_Exception *exception_object);
90#else
91extern _Unwind_Reason_Code
92    _Unwind_RaiseException(struct _Unwind_Exception *exception_object);
93extern void _Unwind_Resume(struct _Unwind_Exception *exception_object);
94#endif
95extern void _Unwind_DeleteException(struct _Unwind_Exception *exception_object);
96extern uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index);
97extern void _Unwind_SetGR(struct _Unwind_Context *context, int index,
98                          uintptr_t new_value);
99extern uintptr_t _Unwind_GetIP(struct _Unwind_Context *context);
100extern void _Unwind_SetIP(struct _Unwind_Context *, uintptr_t new_value);
101extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context);
102extern uintptr_t
103    _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context);
104#if __arm__
105extern _Unwind_Reason_Code
106    _Unwind_SjLj_ForcedUnwind(struct _Unwind_Exception *exception_object,
107                              _Unwind_Stop_Fn stop, void *stop_parameter);
108#else
109extern _Unwind_Reason_Code
110    _Unwind_ForcedUnwind(struct _Unwind_Exception *exception_object,
111                         _Unwind_Stop_Fn stop, void *stop_parameter);
112#endif
113
114#if __arm__
115typedef struct _Unwind_FunctionContext *_Unwind_FunctionContext_t;
116extern void _Unwind_SjLj_Register(_Unwind_FunctionContext_t fc);
117extern void _Unwind_SjLj_Unregister(_Unwind_FunctionContext_t fc);
118#endif
119
120//
121// The following are semi-suppoted extensions to the C++ ABI
122//
123
124//
125//  called by __cxa_rethrow().
126//
127#if __arm__
128extern _Unwind_Reason_Code
129    _Unwind_SjLj_Resume_or_Rethrow(struct _Unwind_Exception *exception_object);
130#else
131extern _Unwind_Reason_Code
132    _Unwind_Resume_or_Rethrow(struct _Unwind_Exception *exception_object);
133#endif
134
135// _Unwind_Backtrace() is a gcc extension that walks the stack and calls the
136// _Unwind_Trace_Fn once per frame until it reaches the bottom of the stack
137// or the _Unwind_Trace_Fn function returns something other than _URC_NO_REASON.
138typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *,
139                                                void *);
140extern _Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *);
141
142// _Unwind_GetCFA is a gcc extension that can be called from within a
143// personality handler to get the CFA (stack pointer before call) of
144// current frame.
145extern uintptr_t _Unwind_GetCFA(struct _Unwind_Context *);
146
147
148// _Unwind_GetIPInfo is a gcc extension that can be called from within a
149// personality handler.  Similar to _Unwind_GetIP() but also returns in
150// *ipBefore a non-zero value if the instruction pointer is at or before the
151// instruction causing the unwind. Normally, in a function call, the IP returned
152// is the return address which is after the call instruction and may be past the
153// end of the function containing the call instruction.
154extern uintptr_t _Unwind_GetIPInfo(struct _Unwind_Context *context,
155                                   int *ipBefore);
156
157
158// __register_frame() is used with dynamically generated code to register the
159// FDE for a generated (JIT) code.  The FDE must use pc-rel addressing to point
160// to its function and optional LSDA.
161// __register_frame() has existed in all versions of Mac OS X, but in 10.4 and
162// 10.5 it was buggy and did not actually register the FDE with the unwinder.
163// In 10.6 and later it does register properly.
164extern void __register_frame(const void *fde);
165extern void __deregister_frame(const void *fde);
166
167// _Unwind_Find_FDE() will locate the FDE if the pc is in some function that has
168// an associated FDE. Note, Mac OS X 10.6 and later, introduces "compact unwind
169// info" which the runtime uses in preference to dwarf unwind info.  This
170// function will only work if the target function has an FDE but no compact
171// unwind info.
172struct dwarf_eh_bases {
173  uintptr_t tbase;
174  uintptr_t dbase;
175  uintptr_t func;
176};
177extern const void *_Unwind_Find_FDE(const void *pc, struct dwarf_eh_bases *);
178
179
180// This function attempts to find the start (address of first instruction) of
181// a function given an address inside the function.  It only works if the
182// function has an FDE (dwarf unwind info).
183// This function is unimplemented on Mac OS X 10.6 and later.  Instead, use
184// _Unwind_Find_FDE() and look at the dwarf_eh_bases.func result.
185extern void *_Unwind_FindEnclosingFunction(void *pc);
186
187// Mac OS X does not support text-rel and data-rel addressing so these functions
188// are unimplemented
189extern uintptr_t _Unwind_GetDataRelBase(struct _Unwind_Context *context)
190    LIBUNWIND_UNAVAIL;
191extern uintptr_t _Unwind_GetTextRelBase(struct _Unwind_Context *context)
192    LIBUNWIND_UNAVAIL;
193
194// Mac OS X 10.4 and 10.5 had implementations of these functions in
195// libgcc_s.dylib, but they never worked.
196/// These functions are no longer available on Mac OS X.
197extern void __register_frame_info_bases(const void *fde, void *ob, void *tb,
198                                        void *db) LIBUNWIND_UNAVAIL;
199extern void __register_frame_info(const void *fde, void *ob)
200    LIBUNWIND_UNAVAIL;
201extern void __register_frame_info_table_bases(const void *fde, void *ob,
202                                              void *tb, void *db)
203    LIBUNWIND_UNAVAIL;
204extern void __register_frame_info_table(const void *fde, void *ob)
205    LIBUNWIND_UNAVAIL;
206extern void __register_frame_table(const void *fde)
207    LIBUNWIND_UNAVAIL;
208extern void *__deregister_frame_info(const void *fde)
209    LIBUNWIND_UNAVAIL;
210extern void *__deregister_frame_info_bases(const void *fde)
211    LIBUNWIND_UNAVAIL;
212
213#ifdef __cplusplus
214}
215#endif
216
217#endif // __UNWIND_H__
218