1 | /* Exception handling and frame unwind runtime interface routines. |
2 | Copyright (C) 2001-2016 Free Software Foundation, Inc. |
3 | |
4 | This file is part of the GNU C Library. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either |
9 | version 2.1 of the License, or (at your option) any later version. |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | /* This is derived from the C++ ABI for IA-64. Where we diverge |
21 | for cross-architecture compatibility are noted with "@@@". */ |
22 | |
23 | #ifndef _UNWIND_H |
24 | #define _UNWIND_H 1 |
25 | |
26 | #ifdef __cplusplus |
27 | extern "C" { |
28 | #endif |
29 | |
30 | /* Level 1: Base ABI */ |
31 | |
32 | /* @@@ The IA-64 ABI uses uint64 throughout. Most places this is |
33 | inefficient for 32-bit and smaller machines. */ |
34 | typedef unsigned _Unwind_Word __attribute__((__mode__(__unwind_word__))); |
35 | typedef signed _Unwind_Sword __attribute__((__mode__(__unwind_word__))); |
36 | #if defined(__ia64__) && defined(__hpux__) |
37 | typedef unsigned _Unwind_Ptr __attribute__((__mode__(__word__))); |
38 | #else |
39 | typedef unsigned _Unwind_Ptr __attribute__((__mode__(__pointer__))); |
40 | #endif |
41 | typedef unsigned _Unwind_Internal_Ptr __attribute__((__mode__(__pointer__))); |
42 | |
43 | /* @@@ The IA-64 ABI uses a 64-bit word to identify the producer and |
44 | consumer of an exception. We'll go along with this for now even on |
45 | 32-bit machines. We'll need to provide some other option for |
46 | 16-bit machines and for machines with > 8 bits per byte. */ |
47 | typedef unsigned _Unwind_Exception_Class __attribute__((__mode__(__DI__))); |
48 | |
49 | /* The unwind interface uses reason codes in several contexts to |
50 | identify the reasons for failures or other actions. */ |
51 | typedef enum |
52 | { |
53 | _URC_NO_REASON = 0, |
54 | _URC_FOREIGN_EXCEPTION_CAUGHT = 1, |
55 | _URC_FATAL_PHASE2_ERROR = 2, |
56 | _URC_FATAL_PHASE1_ERROR = 3, |
57 | _URC_NORMAL_STOP = 4, |
58 | _URC_END_OF_STACK = 5, |
59 | _URC_HANDLER_FOUND = 6, |
60 | _URC_INSTALL_CONTEXT = 7, |
61 | _URC_CONTINUE_UNWIND = 8 |
62 | } _Unwind_Reason_Code; |
63 | |
64 | |
65 | /* The unwind interface uses a pointer to an exception header object |
66 | as its representation of an exception being thrown. In general, the |
67 | full representation of an exception object is language- and |
68 | implementation-specific, but it will be prefixed by a header |
69 | understood by the unwind interface. */ |
70 | |
71 | struct _Unwind_Exception; |
72 | |
73 | typedef void (*_Unwind_Exception_Cleanup_Fn) (_Unwind_Reason_Code, |
74 | struct _Unwind_Exception *); |
75 | |
76 | struct _Unwind_Exception |
77 | { |
78 | _Unwind_Exception_Class exception_class; |
79 | _Unwind_Exception_Cleanup_Fn exception_cleanup; |
80 | _Unwind_Word private_1; |
81 | _Unwind_Word private_2; |
82 | |
83 | /* @@@ The IA-64 ABI says that this structure must be double-word aligned. |
84 | Taking that literally does not make much sense generically. Instead we |
85 | provide the maximum alignment required by any type for the machine. */ |
86 | } __attribute__((__aligned__)); |
87 | |
88 | |
89 | /* The ACTIONS argument to the personality routine is a bitwise OR of one |
90 | or more of the following constants. */ |
91 | typedef int _Unwind_Action; |
92 | |
93 | #define _UA_SEARCH_PHASE 1 |
94 | #define _UA_CLEANUP_PHASE 2 |
95 | #define _UA_HANDLER_FRAME 4 |
96 | #define _UA_FORCE_UNWIND 8 |
97 | #define _UA_END_OF_STACK 16 |
98 | |
99 | /* This is an opaque type used to refer to a system-specific data |
100 | structure used by the system unwinder. This context is created and |
101 | destroyed by the system, and passed to the personality routine |
102 | during unwinding. */ |
103 | struct _Unwind_Context; |
104 | |
105 | /* Raise an exception, passing along the given exception object. */ |
106 | extern _Unwind_Reason_Code _Unwind_RaiseException (struct _Unwind_Exception *); |
107 | |
108 | /* Raise an exception for forced unwinding. */ |
109 | |
110 | typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn) |
111 | (int, _Unwind_Action, _Unwind_Exception_Class, |
112 | struct _Unwind_Exception *, struct _Unwind_Context *, void *); |
113 | |
114 | extern _Unwind_Reason_Code _Unwind_ForcedUnwind (struct _Unwind_Exception *, |
115 | _Unwind_Stop_Fn, |
116 | void *); |
117 | |
118 | /* Helper to invoke the exception_cleanup routine. */ |
119 | extern void _Unwind_DeleteException (struct _Unwind_Exception *); |
120 | |
121 | /* Resume propagation of an existing exception. This is used after |
122 | e.g. executing cleanup code, and not to implement rethrowing. */ |
123 | extern void _Unwind_Resume (struct _Unwind_Exception *); |
124 | |
125 | /* @@@ Use unwind data to perform a stack backtrace. The trace callback |
126 | is called for every stack frame in the call chain, but no cleanup |
127 | actions are performed. */ |
128 | typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn) |
129 | (struct _Unwind_Context *, void *); |
130 | |
131 | extern _Unwind_Reason_Code _Unwind_Backtrace (_Unwind_Trace_Fn, void *); |
132 | |
133 | /* These functions are used for communicating information about the unwind |
134 | context (i.e. the unwind descriptors and the user register state) between |
135 | the unwind library and the personality routine and landing pad. Only |
136 | selected registers maybe manipulated. */ |
137 | |
138 | extern _Unwind_Word _Unwind_GetGR (struct _Unwind_Context *, int); |
139 | extern void _Unwind_SetGR (struct _Unwind_Context *, int, _Unwind_Word); |
140 | |
141 | extern _Unwind_Ptr _Unwind_GetIP (struct _Unwind_Context *); |
142 | extern void _Unwind_SetIP (struct _Unwind_Context *, _Unwind_Ptr); |
143 | |
144 | /* @@@ Retrieve the CFA of the given context. */ |
145 | extern _Unwind_Word _Unwind_GetCFA (struct _Unwind_Context *); |
146 | |
147 | extern void *_Unwind_GetLanguageSpecificData (struct _Unwind_Context *); |
148 | |
149 | extern _Unwind_Ptr _Unwind_GetRegionStart (struct _Unwind_Context *); |
150 | |
151 | |
152 | /* The personality routine is the function in the C++ (or other language) |
153 | runtime library which serves as an interface between the system unwind |
154 | library and language-specific exception handling semantics. It is |
155 | specific to the code fragment described by an unwind info block, and |
156 | it is always referenced via the pointer in the unwind info block, and |
157 | hence it has no ABI-specified name. |
158 | |
159 | Note that this implies that two different C++ implementations can |
160 | use different names, and have different contents in the language |
161 | specific data area. Moreover, that the language specific data |
162 | area contains no version info because name of the function invoked |
163 | provides more effective versioning by detecting at link time the |
164 | lack of code to handle the different data format. */ |
165 | |
166 | typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn) |
167 | (int, _Unwind_Action, _Unwind_Exception_Class, |
168 | struct _Unwind_Exception *, struct _Unwind_Context *); |
169 | |
170 | /* @@@ The following alternate entry points are for setjmp/longjmp |
171 | based unwinding. */ |
172 | |
173 | struct SjLj_Function_Context; |
174 | extern void _Unwind_SjLj_Register (struct SjLj_Function_Context *); |
175 | extern void _Unwind_SjLj_Unregister (struct SjLj_Function_Context *); |
176 | |
177 | extern _Unwind_Reason_Code _Unwind_SjLj_RaiseException |
178 | (struct _Unwind_Exception *); |
179 | extern _Unwind_Reason_Code _Unwind_SjLj_ForcedUnwind |
180 | (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *); |
181 | extern void _Unwind_SjLj_Resume (struct _Unwind_Exception *); |
182 | |
183 | /* @@@ The following provide access to the base addresses for text |
184 | and data-relative addressing in the LDSA. In order to stay link |
185 | compatible with the standard ABI for IA-64, we inline these. */ |
186 | |
187 | #ifdef __ia64__ |
188 | #include <stdlib.h> |
189 | |
190 | static inline _Unwind_Ptr |
191 | _Unwind_GetDataRelBase (struct _Unwind_Context *_C) |
192 | { |
193 | /* The GP is stored in R1. */ |
194 | return _Unwind_GetGR (_C, 1); |
195 | } |
196 | |
197 | static inline _Unwind_Ptr |
198 | _Unwind_GetTextRelBase (struct _Unwind_Context *_C) |
199 | { |
200 | abort (); |
201 | return 0; |
202 | } |
203 | |
204 | /* @@@ Retrieve the Backing Store Pointer of the given context. */ |
205 | extern _Unwind_Word _Unwind_GetBSP (struct _Unwind_Context *); |
206 | #else |
207 | extern _Unwind_Ptr _Unwind_GetDataRelBase (struct _Unwind_Context *); |
208 | extern _Unwind_Ptr _Unwind_GetTextRelBase (struct _Unwind_Context *); |
209 | #endif |
210 | |
211 | /* @@@ Given an address, return the entry point of the function that |
212 | contains it. */ |
213 | extern void * _Unwind_FindEnclosingFunction (void *pc); |
214 | |
215 | #ifdef __cplusplus |
216 | } |
217 | #endif |
218 | |
219 | #endif /* unwind.h */ |
220 | |