1 /* Exception handling and frame unwind runtime interface routines. 2 Copyright (C) 2001-2018 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 3, 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 Under Section 7 of GPL version 3, you are granted additional 17 permissions described in the GCC Runtime Library Exception, version 18 3.1, as published by the Free Software Foundation. 19 20 You should have received a copy of the GNU General Public License and 21 a copy of the GCC Runtime Library Exception along with this program; 22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 <http://www.gnu.org/licenses/>. */ 24 25 /* This is derived from the C++ ABI for IA-64. Where we diverge 26 for cross-architecture compatibility are noted with "@@@". */ 27 28 #ifndef _UNWIND_H 29 #define _UNWIND_H 30 31 #if defined (__SEH__) && !defined (__USING_SJLJ_EXCEPTIONS__) 32 /* Only for _GCC_specific_handler. */ 33 #include <windows.h> 34 #endif 35 36 #ifndef HIDE_EXPORTS 37 #pragma GCC visibility push(default) 38 #endif 39 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 /* Level 1: Base ABI */ 45 46 /* @@@ The IA-64 ABI uses uint64 throughout. Most places this is 47 inefficient for 32-bit and smaller machines. */ 48 typedef unsigned _Unwind_Word __attribute__((__mode__(__unwind_word__))); 49 typedef signed _Unwind_Sword __attribute__((__mode__(__unwind_word__))); 50 #if defined(__ia64__) && defined(__hpux__) 51 typedef unsigned _Unwind_Ptr __attribute__((__mode__(__word__))); 52 #else 53 typedef unsigned _Unwind_Ptr __attribute__((__mode__(__pointer__))); 54 #endif 55 typedef unsigned _Unwind_Internal_Ptr __attribute__((__mode__(__pointer__))); 56 57 /* @@@ The IA-64 ABI uses a 64-bit word to identify the producer and 58 consumer of an exception. We'll go along with this for now even on 59 32-bit machines. We'll need to provide some other option for 60 16-bit machines and for machines with > 8 bits per byte. */ 61 typedef unsigned _Unwind_Exception_Class __attribute__((__mode__(__DI__))); 62 63 /* The unwind interface uses reason codes in several contexts to 64 identify the reasons for failures or other actions. */ 65 typedef enum 66 { 67 _URC_NO_REASON = 0, 68 _URC_FOREIGN_EXCEPTION_CAUGHT = 1, 69 _URC_FATAL_PHASE2_ERROR = 2, 70 _URC_FATAL_PHASE1_ERROR = 3, 71 _URC_NORMAL_STOP = 4, 72 _URC_END_OF_STACK = 5, 73 _URC_HANDLER_FOUND = 6, 74 _URC_INSTALL_CONTEXT = 7, 75 _URC_CONTINUE_UNWIND = 8 76 } _Unwind_Reason_Code; 77 78 79 /* The unwind interface uses a pointer to an exception header object 80 as its representation of an exception being thrown. In general, the 81 full representation of an exception object is language- and 82 implementation-specific, but it will be prefixed by a header 83 understood by the unwind interface. */ 84 85 struct _Unwind_Exception; 86 87 typedef void (*_Unwind_Exception_Cleanup_Fn) (_Unwind_Reason_Code, 88 struct _Unwind_Exception *); 89 90 struct _Unwind_Exception 91 { 92 _Unwind_Exception_Class exception_class; 93 _Unwind_Exception_Cleanup_Fn exception_cleanup; 94 95 #if !defined (__USING_SJLJ_EXCEPTIONS__) && defined (__SEH__) 96 _Unwind_Word private_[6]; 97 #else 98 _Unwind_Word private_1; 99 _Unwind_Word private_2; 100 #endif 101 102 /* @@@ The IA-64 ABI says that this structure must be double-word aligned. 103 Taking that literally does not make much sense generically. Instead we 104 provide the maximum alignment required by any type for the machine. */ 105 } __attribute__((__aligned__)); 106 107 108 /* The ACTIONS argument to the personality routine is a bitwise OR of one 109 or more of the following constants. */ 110 typedef int _Unwind_Action; 111 112 #define _UA_SEARCH_PHASE 1 113 #define _UA_CLEANUP_PHASE 2 114 #define _UA_HANDLER_FRAME 4 115 #define _UA_FORCE_UNWIND 8 116 #define _UA_END_OF_STACK 16 117 118 /* The target can override this macro to define any back-end-specific 119 attributes required for the lowest-level stack frame. */ 120 #ifndef LIBGCC2_UNWIND_ATTRIBUTE 121 #define LIBGCC2_UNWIND_ATTRIBUTE 122 #endif 123 124 /* This is an opaque type used to refer to a system-specific data 125 structure used by the system unwinder. This context is created and 126 destroyed by the system, and passed to the personality routine 127 during unwinding. */ 128 struct _Unwind_Context; 129 130 /* Raise an exception, passing along the given exception object. */ 131 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 132 _Unwind_RaiseException (struct _Unwind_Exception *); 133 134 /* Raise an exception for forced unwinding. */ 135 136 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn) 137 (int, _Unwind_Action, _Unwind_Exception_Class, 138 struct _Unwind_Exception *, struct _Unwind_Context *, void *); 139 140 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 141 _Unwind_ForcedUnwind (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *); 142 143 /* Helper to invoke the exception_cleanup routine. */ 144 extern void _Unwind_DeleteException (struct _Unwind_Exception *); 145 146 /* Resume propagation of an existing exception. This is used after 147 e.g. executing cleanup code, and not to implement rethrowing. */ 148 extern void LIBGCC2_UNWIND_ATTRIBUTE 149 _Unwind_Resume (struct _Unwind_Exception *); 150 151 /* @@@ Resume propagation of a FORCE_UNWIND exception, or to rethrow 152 a normal exception that was handled. */ 153 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 154 _Unwind_Resume_or_Rethrow (struct _Unwind_Exception *); 155 156 /* @@@ Use unwind data to perform a stack backtrace. The trace callback 157 is called for every stack frame in the call chain, but no cleanup 158 actions are performed. */ 159 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn) 160 (struct _Unwind_Context *, void *); 161 162 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 163 _Unwind_Backtrace (_Unwind_Trace_Fn, void *); 164 165 /* These functions are used for communicating information about the unwind 166 context (i.e. the unwind descriptors and the user register state) between 167 the unwind library and the personality routine and landing pad. Only 168 selected registers may be manipulated. */ 169 170 extern _Unwind_Word _Unwind_GetGR (struct _Unwind_Context *, int); 171 extern void _Unwind_SetGR (struct _Unwind_Context *, int, _Unwind_Word); 172 173 extern _Unwind_Ptr _Unwind_GetIP (struct _Unwind_Context *); 174 extern _Unwind_Ptr _Unwind_GetIPInfo (struct _Unwind_Context *, int *); 175 extern void _Unwind_SetIP (struct _Unwind_Context *, _Unwind_Ptr); 176 177 /* @@@ Retrieve the CFA of the given context. */ 178 extern _Unwind_Word _Unwind_GetCFA (struct _Unwind_Context *); 179 180 extern void *_Unwind_GetLanguageSpecificData (struct _Unwind_Context *); 181 182 extern _Unwind_Ptr _Unwind_GetRegionStart (struct _Unwind_Context *); 183 184 185 /* The personality routine is the function in the C++ (or other language) 186 runtime library which serves as an interface between the system unwind 187 library and language-specific exception handling semantics. It is 188 specific to the code fragment described by an unwind info block, and 189 it is always referenced via the pointer in the unwind info block, and 190 hence it has no ABI-specified name. 191 192 Note that this implies that two different C++ implementations can 193 use different names, and have different contents in the language 194 specific data area. Moreover, that the language specific data 195 area contains no version info because name of the function invoked 196 provides more effective versioning by detecting at link time the 197 lack of code to handle the different data format. */ 198 199 typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn) 200 (int, _Unwind_Action, _Unwind_Exception_Class, 201 struct _Unwind_Exception *, struct _Unwind_Context *); 202 203 /* @@@ The following alternate entry points are for setjmp/longjmp 204 based unwinding. */ 205 206 struct SjLj_Function_Context; 207 extern void _Unwind_SjLj_Register (struct SjLj_Function_Context *); 208 extern void _Unwind_SjLj_Unregister (struct SjLj_Function_Context *); 209 210 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 211 _Unwind_SjLj_RaiseException (struct _Unwind_Exception *); 212 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 213 _Unwind_SjLj_ForcedUnwind (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *); 214 extern void LIBGCC2_UNWIND_ATTRIBUTE 215 _Unwind_SjLj_Resume (struct _Unwind_Exception *); 216 extern _Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE 217 _Unwind_SjLj_Resume_or_Rethrow (struct _Unwind_Exception *); 218 219 /* @@@ The following provide access to the base addresses for text 220 and data-relative addressing in the LDSA. In order to stay link 221 compatible with the standard ABI for IA-64, we inline these. */ 222 223 #ifdef __ia64__ 224 static inline _Unwind_Ptr 225 _Unwind_GetDataRelBase (struct _Unwind_Context *_C) 226 { 227 /* The GP is stored in R1. */ 228 return _Unwind_GetGR (_C, 1); 229 } 230 231 static inline _Unwind_Ptr 232 _Unwind_GetTextRelBase (struct _Unwind_Context *_C __attribute__ ((__unused__))) 233 { 234 __builtin_abort (); 235 return 0; 236 } 237 238 /* @@@ Retrieve the Backing Store Pointer of the given context. */ 239 extern _Unwind_Word _Unwind_GetBSP (struct _Unwind_Context *); 240 #else 241 extern _Unwind_Ptr _Unwind_GetDataRelBase (struct _Unwind_Context *); 242 extern _Unwind_Ptr _Unwind_GetTextRelBase (struct _Unwind_Context *); 243 #endif 244 245 /* @@@ Given an address, return the entry point of the function that 246 contains it. */ 247 extern void * _Unwind_FindEnclosingFunction (void *pc); 248 249 #ifndef __SIZEOF_LONG__ 250 #error "__SIZEOF_LONG__ macro not defined" 251 #endif 252 253 #ifndef __SIZEOF_POINTER__ 254 #error "__SIZEOF_POINTER__ macro not defined" 255 #endif 256 257 258 /* leb128 type numbers have a potentially unlimited size. 259 The target of the following definitions of _sleb128_t and _uleb128_t 260 is to have efficient data types large enough to hold the leb128 type 261 numbers used in the unwind code. 262 Mostly these types will simply be defined to long and unsigned long 263 except when a unsigned long data type on the target machine is not 264 capable of storing a pointer. */ 265 266 #if __SIZEOF_LONG__ >= __SIZEOF_POINTER__ 267 typedef long _sleb128_t; 268 typedef unsigned long _uleb128_t; 269 #elif __SIZEOF_LONG_LONG__ >= __SIZEOF_POINTER__ 270 typedef long long _sleb128_t; 271 typedef unsigned long long _uleb128_t; 272 #else 273 # error "What type shall we use for _sleb128_t?" 274 #endif 275 276 #if defined (__SEH__) && !defined (__USING_SJLJ_EXCEPTIONS__) 277 /* Handles the mapping from SEH to GCC interfaces. */ 278 EXCEPTION_DISPOSITION _GCC_specific_handler (PEXCEPTION_RECORD, void *, 279 PCONTEXT, PDISPATCHER_CONTEXT, 280 _Unwind_Personality_Fn); 281 #endif 282 283 #ifdef __cplusplus 284 } 285 #endif 286 287 #ifndef HIDE_EXPORTS 288 #pragma GCC visibility pop 289 #endif 290 291 /* Additional actions to unwind number of stack frames. */ 292 #define _Unwind_Frames_Extra(frames) 293 294 /* Increment frame count. */ 295 #define _Unwind_Frames_Increment(context, frames) frames++ 296 297 #endif /* unwind.h */ 298