1/* -*- mode: C++; c-basic-offset: 4; -*-
2 *
3 * Copyright (c) 2010-2011 Apple Inc. All rights reserved.
4 *
5 * @APPLE_LICENSE_HEADER_START@
6 *
7 * This file contains Original Code and/or Modifications of Original Code
8 * as defined in and that are subject to the Apple Public Source License
9 * Version 2.0 (the 'License'). You may not use this file except in
10 * compliance with the License. Please obtain a copy of the License at
11 * http://www.opensource.apple.com/apsl/ and read it before using this
12 * file.
13 *
14 * The Original Code and all software distributed under the License are
15 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
16 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
17 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
19 * Please see the License for the specific language governing rights and
20 * limitations under the License.
21 *
22 * @APPLE_LICENSE_HEADER_END@
23 *
24 *
25 *            C interface to libuwind
26 *
27 * Source compatible with Level 1 Base ABI documented at:
28 *    http://www.codesourcery.com/public/cxx-abi/abi-eh.html
29 *
30 */
31
32
33#ifndef __UNWIND_H__
34#define __UNWIND_H__
35
36#include <stdint.h>
37#include <stddef.h>
38#include <Availability.h>
39
40
41typedef enum {
42	_URC_NO_REASON = 0,
43	_URC_FOREIGN_EXCEPTION_CAUGHT = 1,
44	_URC_FATAL_PHASE2_ERROR = 2,
45	_URC_FATAL_PHASE1_ERROR = 3,
46	_URC_NORMAL_STOP = 4,
47	_URC_END_OF_STACK = 5,
48	_URC_HANDLER_FOUND = 6,
49	_URC_INSTALL_CONTEXT = 7,
50	_URC_CONTINUE_UNWIND = 8
51} _Unwind_Reason_Code;
52
53typedef enum {
54        _UA_SEARCH_PHASE = 1,
55        _UA_CLEANUP_PHASE = 2,
56        _UA_HANDLER_FRAME = 4,
57        _UA_FORCE_UNWIND = 8,
58        _UA_END_OF_STACK = 16	// gcc extension to C++ ABI
59} _Unwind_Action;
60
61
62struct _Unwind_Context;		// opaque
63struct _Unwind_Exception;	// forward declaration
64
65struct _Unwind_Exception {
66	uint64_t                   exception_class;
67	void					 (*exception_cleanup)(_Unwind_Reason_Code reason, struct _Unwind_Exception* exc);
68	uintptr_t                  private_1;        // non-zero means forced unwind
69	uintptr_t                  private_2;        // holds sp that phase1 found for phase2 to use
70#if !__LP64__
71	// The gcc implementation of _Unwind_Exception used attribute mode on the above fields
72	// which had the side effect of causing this whole struct to round up to 32 bytes in size.
73	// To be more explicit, we add pad fields added for binary compatibility.
74	uint32_t				reserved[3];
75#endif
76};
77
78
79typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
80		(int version,
81		 _Unwind_Action actions,
82		 uint64_t exceptionClass,
83		 struct _Unwind_Exception* exceptionObject,
84		 struct _Unwind_Context* context,
85		 void* stop_parameter );
86
87
88typedef _Unwind_Reason_Code (*__personality_routine)
89	    (int version,
90	     _Unwind_Action actions,
91	     uint64_t exceptionClass,
92	     struct _Unwind_Exception* exceptionObject,
93	     struct _Unwind_Context* context);
94
95
96
97#ifdef __cplusplus
98extern "C" {
99#endif
100
101//
102// The following are the base functions documented by the C++ ABI
103//
104#if __arm__
105	extern _Unwind_Reason_Code _Unwind_SjLj_RaiseException(struct _Unwind_Exception* exception_object);
106	extern void		          _Unwind_SjLj_Resume(struct _Unwind_Exception* exception_object);
107#else
108	extern _Unwind_Reason_Code _Unwind_RaiseException(struct _Unwind_Exception* exception_object);
109	extern void		          _Unwind_Resume(struct _Unwind_Exception* exception_object);
110#endif
111extern void		_Unwind_DeleteException(struct _Unwind_Exception* exception_object);
112extern uintptr_t _Unwind_GetGR(struct _Unwind_Context* context, int index);
113extern void		_Unwind_SetGR(struct _Unwind_Context* context, int index, uintptr_t new_value);
114extern uintptr_t _Unwind_GetIP(struct _Unwind_Context* context);
115extern void		_Unwind_SetIP(struct _Unwind_Context*, uintptr_t new_value);
116extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context* context);
117extern uintptr_t _Unwind_GetLanguageSpecificData(struct _Unwind_Context* context);
118#if __arm__
119	extern _Unwind_Reason_Code _Unwind_SjLj_ForcedUnwind(struct _Unwind_Exception* exception_object, _Unwind_Stop_Fn stop, void* stop_parameter );
120#else
121	extern _Unwind_Reason_Code _Unwind_ForcedUnwind(struct _Unwind_Exception* exception_object, _Unwind_Stop_Fn stop, void* stop_parameter );
122#endif
123
124#if __arm__
125	typedef struct _Unwind_FunctionContext* _Unwind_FunctionContext_t;
126	extern void _Unwind_SjLj_Register(_Unwind_FunctionContext_t fc);
127	extern void _Unwind_SjLj_Unregister(_Unwind_FunctionContext_t fc);
128#endif
129
130//
131// The following are semi-suppoted extensions to the C++ ABI
132//
133
134
135//
136//	called by __cxa_rethrow().
137//
138#if __arm__
139	extern _Unwind_Reason_Code _Unwind_SjLj_Resume_or_Rethrow(struct _Unwind_Exception* exception_object);
140#else
141	extern _Unwind_Reason_Code _Unwind_Resume_or_Rethrow(struct _Unwind_Exception* exception_object);
142#endif
143
144
145//
146// _Unwind_Backtrace() is a gcc extension that walks the stack and calls the
147// _Unwind_Trace_Fn once per frame until it reaches the bottom of the stack
148// or the _Unwind_Trace_Fn function returns something other than _URC_NO_REASON.
149//
150typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context*, void*);
151extern _Unwind_Reason_Code	_Unwind_Backtrace(_Unwind_Trace_Fn, void*);
152
153
154//
155// _Unwind_GetCFA is a gcc extension that can be called from within a personality
156// handler to get the CFA (stack pointer before call) of current frame.
157//
158extern uintptr_t _Unwind_GetCFA(struct _Unwind_Context*);
159
160
161//
162// _Unwind_GetIPInfo is a gcc extension that can be called from within a personality
163// handler.  Similar to _Unwind_GetIP() but also returns in *ipBefore a non-zero
164// value if the instruction pointer is at or before the instruction causing
165// the unwind.  Normally, in a function call, the IP returned is the return address
166// which is after the call instruction and may be past the end of the function
167// containing the call instruction.
168//
169extern uintptr_t _Unwind_GetIPInfo(struct _Unwind_Context* context, int* ipBefore);
170
171
172//
173// __register_frame() is used with dynamically generated code to register the FDE
174// for a generated (JIT) code.  The FDE must use pc-rel addressing to point to its
175// function and optional LSDA.  __register_frame() has existed in all versions of
176// Mac OS X, but in 10.4 and 10.5 it was buggy and did not actually register the
177// FDE with the unwinder.  In 10.6 and later it does register properly.
178//
179extern void	__register_frame(const void* fde);
180extern void	__deregister_frame(const void* fde);
181
182
183//
184// _Unwind_Find_FDE() will locate the FDE if the pc is in some function that has
185// an associated FDE. Note, Mac OS X 10.6 and later, introduces "compact unwind info"
186// which the runtime uses in preference to dwarf unwind info.  This function
187// will only work if the target function has an FDE but no compact unwind info.
188//
189struct dwarf_eh_bases
190{
191    uintptr_t tbase;
192    uintptr_t dbase;
193    uintptr_t func;
194};
195extern const void* _Unwind_Find_FDE(const void* pc, struct dwarf_eh_bases*);
196
197
198//
199// This function attempts to find the start (address of first instruction) of
200// a function given an address inside the function.  It only works if the function
201// has an FDE (dwarf unwind info).
202// This function is unimplemented on Mac OS X 10.6 and later.  Instead, use
203// _Unwind_Find_FDE() and look at the dwarf_eh_bases.func result.
204extern void* _Unwind_FindEnclosingFunction(void* pc);
205
206
207// Mac OS X does not support text-rel and data-rel addressing so these functions are unimplemented
208extern uintptr_t _Unwind_GetDataRelBase(struct _Unwind_Context* context) __attribute__((unavailable));
209extern uintptr_t _Unwind_GetTextRelBase(struct _Unwind_Context* context) __attribute__((unavailable));
210
211
212
213// Mac OS X 10.4 and 10.5 had implementations of these functions in libgcc_s.dylib,
214// but they never worked.  These functions are no longer available.
215extern void	 __register_frame_info_bases(const void* fde, void* ob, void* tb, void* db) __attribute__((unavailable));
216extern void	 __register_frame_info(const void* fde, void* ob) __attribute__((unavailable));
217extern void	 __register_frame_info_table_bases(const void* fde, void* ob,void* tb, void* db) __attribute__((unavailable));
218extern void	 __register_frame_info_table(const void* fde, void* ob) __attribute__((unavailable));
219extern void	 __register_frame_table(const void* fde) __attribute__((unavailable));
220extern void* __deregister_frame_info(const void* fde) __attribute__((unavailable));
221extern void* __deregister_frame_info_bases(const void* fde) __attribute__((unavailable));
222
223
224#ifdef __cplusplus
225}
226#endif
227
228
229
230#endif // __UNWIND_H__
231
232
233