1 /* Exception handling and frame unwind runtime interface routines. 2 Copyright (C) 2001, 2003, 2004, 2006 Free Software Foundation, Inc. 3 4 This file is part of GCC. 5 6 GCC is free software; you can redistribute it and/or modify it 7 under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 GCC is distributed in the hope that it will be useful, but WITHOUT 12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public 14 License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GCC; see the file COPYING. If not, write to the Free 18 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301, USA. */ 20 21 /* As a special exception, if you include this header file into source 22 files compiled by GCC, this header file does not by itself cause 23 the resulting executable to be covered by the GNU General Public 24 License. This exception does not however invalidate any other 25 reasons why the executable file might be covered by the GNU General 26 Public License. */ 27 28 /* This is derived from the C++ ABI for IA-64. Where we diverge 29 for cross-architecture compatibility are noted with "@@@". */ 30 31 #ifndef _UNWIND_H 32 #define _UNWIND_H 33 34 #ifndef HIDE_EXPORTS 35 #pragma GCC visibility push(default) 36 #endif 37 38 #ifdef __cplusplus 39 extern "C" { 40 #endif 41 42 /* Level 1: Base ABI */ 43 44 /* @@@ The IA-64 ABI uses uint64 throughout. Most places this is 45 inefficient for 32-bit and smaller machines. */ 46 typedef unsigned _Unwind_Word __attribute__((__mode__(__unwind_word__))); 47 typedef signed _Unwind_Sword __attribute__((__mode__(__unwind_word__))); 48 #if defined(__ia64__) && defined(__hpux__) 49 typedef unsigned _Unwind_Ptr __attribute__((__mode__(__word__))); 50 #else 51 typedef unsigned _Unwind_Ptr __attribute__((__mode__(__pointer__))); 52 #endif 53 typedef unsigned _Unwind_Internal_Ptr __attribute__((__mode__(__pointer__))); 54 55 /* @@@ The IA-64 ABI uses a 64-bit word to identify the producer and 56 consumer of an exception. We'll go along with this for now even on 57 32-bit machines. We'll need to provide some other option for 58 16-bit machines and for machines with > 8 bits per byte. */ 59 typedef unsigned _Unwind_Exception_Class __attribute__((__mode__(__DI__))); 60 61 /* The unwind interface uses reason codes in several contexts to 62 identify the reasons for failures or other actions. */ 63 typedef enum 64 { 65 _URC_NO_REASON = 0, 66 _URC_FOREIGN_EXCEPTION_CAUGHT = 1, 67 _URC_FATAL_PHASE2_ERROR = 2, 68 _URC_FATAL_PHASE1_ERROR = 3, 69 _URC_NORMAL_STOP = 4, 70 _URC_END_OF_STACK = 5, 71 _URC_HANDLER_FOUND = 6, 72 _URC_INSTALL_CONTEXT = 7, 73 _URC_CONTINUE_UNWIND = 8 74 } _Unwind_Reason_Code; 75 76 77 /* The unwind interface uses a pointer to an exception header object 78 as its representation of an exception being thrown. In general, the 79 full representation of an exception object is language- and 80 implementation-specific, but it will be prefixed by a header 81 understood by the unwind interface. */ 82 83 struct _Unwind_Exception; 84 85 typedef void (*_Unwind_Exception_Cleanup_Fn) (_Unwind_Reason_Code, 86 struct _Unwind_Exception *); 87 88 struct _Unwind_Exception 89 { 90 _Unwind_Exception_Class exception_class; 91 _Unwind_Exception_Cleanup_Fn exception_cleanup; 92 _Unwind_Word private_1; 93 _Unwind_Word private_2; 94 95 /* @@@ The IA-64 ABI says that this structure must be double-word aligned. 96 Taking that literally does not make much sense generically. Instead we 97 provide the maximum alignment required by any type for the machine. */ 98 } __attribute__((__aligned__)); 99 100 101 /* The ACTIONS argument to the personality routine is a bitwise OR of one 102 or more of the following constants. */ 103 typedef int _Unwind_Action; 104 105 #define _UA_SEARCH_PHASE 1 106 #define _UA_CLEANUP_PHASE 2 107 #define _UA_HANDLER_FRAME 4 108 #define _UA_FORCE_UNWIND 8 109 #define _UA_END_OF_STACK 16 110 111 /* The target can override this macro to define any back-end-specific 112 attributes required for the lowest-level stack frame. */ 113 #ifndef LIBGCC2_UNWIND_ATTRIBUTE 114 #define LIBGCC2_UNWIND_ATTRIBUTE 115 #endif 116 117 /* This is an opaque type used to refer to a system-specific data 118 structure used by the system unwinder. This context is created and 119 destroyed by the system, and passed to the personality routine 120 during unwinding. */ 121 struct _Unwind_Context; 122 123 /* Raise an exception, passing along the given exception object. */ 124 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 125 _Unwind_RaiseException (struct _Unwind_Exception *); 126 127 /* Raise an exception for forced unwinding. */ 128 129 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn) 130 (int, _Unwind_Action, _Unwind_Exception_Class, 131 struct _Unwind_Exception *, struct _Unwind_Context *, void *); 132 133 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 134 _Unwind_ForcedUnwind (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *); 135 136 /* Helper to invoke the exception_cleanup routine. */ 137 extern void _Unwind_DeleteException (struct _Unwind_Exception *); 138 139 /* Resume propagation of an existing exception. This is used after 140 e.g. executing cleanup code, and not to implement rethrowing. */ 141 extern void LIBGCC2_UNWIND_ATTRIBUTE 142 _Unwind_Resume (struct _Unwind_Exception *); 143 144 /* @@@ Resume propagation of a FORCE_UNWIND exception, or to rethrow 145 a normal exception that was handled. */ 146 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 147 _Unwind_Resume_or_Rethrow (struct _Unwind_Exception *); 148 149 /* @@@ Use unwind data to perform a stack backtrace. The trace callback 150 is called for every stack frame in the call chain, but no cleanup 151 actions are performed. */ 152 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn) 153 (struct _Unwind_Context *, void *); 154 155 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 156 _Unwind_Backtrace (_Unwind_Trace_Fn, void *); 157 158 /* These functions are used for communicating information about the unwind 159 context (i.e. the unwind descriptors and the user register state) between 160 the unwind library and the personality routine and landing pad. Only 161 selected registers may be manipulated. */ 162 163 extern _Unwind_Word _Unwind_GetGR (struct _Unwind_Context *, int); 164 extern void _Unwind_SetGR (struct _Unwind_Context *, int, _Unwind_Word); 165 166 extern _Unwind_Ptr _Unwind_GetIP (struct _Unwind_Context *); 167 extern _Unwind_Ptr _Unwind_GetIPInfo (struct _Unwind_Context *, int *); 168 extern void _Unwind_SetIP (struct _Unwind_Context *, _Unwind_Ptr); 169 170 /* @@@ Retrieve the CFA of the given context. */ 171 extern _Unwind_Word _Unwind_GetCFA (struct _Unwind_Context *); 172 173 extern void *_Unwind_GetLanguageSpecificData (struct _Unwind_Context *); 174 175 extern _Unwind_Ptr _Unwind_GetRegionStart (struct _Unwind_Context *); 176 177 178 /* The personality routine is the function in the C++ (or other language) 179 runtime library which serves as an interface between the system unwind 180 library and language-specific exception handling semantics. It is 181 specific to the code fragment described by an unwind info block, and 182 it is always referenced via the pointer in the unwind info block, and 183 hence it has no ABI-specified name. 184 185 Note that this implies that two different C++ implementations can 186 use different names, and have different contents in the language 187 specific data area. Moreover, that the language specific data 188 area contains no version info because name of the function invoked 189 provides more effective versioning by detecting at link time the 190 lack of code to handle the different data format. */ 191 192 typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn) 193 (int, _Unwind_Action, _Unwind_Exception_Class, 194 struct _Unwind_Exception *, struct _Unwind_Context *); 195 196 /* @@@ The following alternate entry points are for setjmp/longjmp 197 based unwinding. */ 198 199 struct SjLj_Function_Context; 200 extern void _Unwind_SjLj_Register (struct SjLj_Function_Context *); 201 extern void _Unwind_SjLj_Unregister (struct SjLj_Function_Context *); 202 203 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 204 _Unwind_SjLj_RaiseException (struct _Unwind_Exception *); 205 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 206 _Unwind_SjLj_ForcedUnwind (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *); 207 extern void LIBGCC2_UNWIND_ATTRIBUTE 208 _Unwind_SjLj_Resume (struct _Unwind_Exception *); 209 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 210 _Unwind_SjLj_Resume_or_Rethrow (struct _Unwind_Exception *); 211 212 /* @@@ The following provide access to the base addresses for text 213 and data-relative addressing in the LDSA. In order to stay link 214 compatible with the standard ABI for IA-64, we inline these. */ 215 216 #ifdef __ia64__ 217 #include <stdlib.h> 218 219 static inline _Unwind_Ptr 220 _Unwind_GetDataRelBase (struct _Unwind_Context *_C) 221 { 222 /* The GP is stored in R1. */ 223 return _Unwind_GetGR (_C, 1); 224 } 225 226 static inline _Unwind_Ptr 227 _Unwind_GetTextRelBase (struct _Unwind_Context *_C __attribute__ ((__unused__))) 228 { 229 abort (); 230 return 0; 231 } 232 233 /* @@@ Retrieve the Backing Store Pointer of the given context. */ 234 extern _Unwind_Word _Unwind_GetBSP (struct _Unwind_Context *); 235 #else 236 extern _Unwind_Ptr _Unwind_GetDataRelBase (struct _Unwind_Context *); 237 extern _Unwind_Ptr _Unwind_GetTextRelBase (struct _Unwind_Context *); 238 #endif 239 240 /* @@@ Given an address, return the entry point of the function that 241 contains it. */ 242 extern void * _Unwind_FindEnclosingFunction (void *pc); 243 244 #ifndef __SIZEOF_LONG__ 245 #error "__SIZEOF_LONG__ macro not defined" 246 #endif 247 248 #ifndef __SIZEOF_POINTER__ 249 #error "__SIZEOF_POINTER__ macro not defined" 250 #endif 251 252 253 /* leb128 type numbers have a potentially unlimited size. 254 The target of the following definitions of _sleb128_t and _uleb128_t 255 is to have efficient data types large enough to hold the leb128 type 256 numbers used in the unwind code. 257 Mostly these types will simply be defined to long and unsigned long 258 except when a unsigned long data type on the target machine is not 259 capable of storing a pointer. */ 260 261 #if __SIZEOF_LONG__ >= __SIZEOF_POINTER__ 262 typedef long _sleb128_t; 263 typedef unsigned long _uleb128_t; 264 #elif __SIZEOF_LONG_LONG__ >= __SIZEOF_POINTER__ 265 typedef long long _sleb128_t; 266 typedef unsigned long long _uleb128_t; 267 #else 268 # error "What type shall we use for _sleb128_t?" 269 #endif 270 271 #ifdef __cplusplus 272 } 273 #endif 274 275 #ifndef HIDE_EXPORTS 276 #pragma GCC visibility pop 277 #endif 278 279 #endif /* unwind.h */ 280
