Ben Cheng | 7823f2a | 2014-04-08 14:53:42 -0700 | [diff] [blame^] | 1 | /* Exception handling and frame unwind runtime interface routines. |
| 2 | Copyright (C) 2001-2014 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 | #include <stdlib.h> |
| 225 | |
| 226 | static inline _Unwind_Ptr |
| 227 | _Unwind_GetDataRelBase (struct _Unwind_Context *_C) |
| 228 | { |
| 229 | /* The GP is stored in R1. */ |
| 230 | return _Unwind_GetGR (_C, 1); |
| 231 | } |
| 232 | |
| 233 | static inline _Unwind_Ptr |
| 234 | _Unwind_GetTextRelBase (struct _Unwind_Context *_C __attribute__ ((__unused__))) |
| 235 | { |
| 236 | abort (); |
| 237 | return 0; |
| 238 | } |
| 239 | |
| 240 | /* @@@ Retrieve the Backing Store Pointer of the given context. */ |
| 241 | extern _Unwind_Word _Unwind_GetBSP (struct _Unwind_Context *); |
| 242 | #else |
| 243 | extern _Unwind_Ptr _Unwind_GetDataRelBase (struct _Unwind_Context *); |
| 244 | extern _Unwind_Ptr _Unwind_GetTextRelBase (struct _Unwind_Context *); |
| 245 | #endif |
| 246 | |
| 247 | /* @@@ Given an address, return the entry point of the function that |
| 248 | contains it. */ |
| 249 | extern void * _Unwind_FindEnclosingFunction (void *pc); |
| 250 | |
| 251 | #ifndef __SIZEOF_LONG__ |
| 252 | #error "__SIZEOF_LONG__ macro not defined" |
| 253 | #endif |
| 254 | |
| 255 | #ifndef __SIZEOF_POINTER__ |
| 256 | #error "__SIZEOF_POINTER__ macro not defined" |
| 257 | #endif |
| 258 | |
| 259 | |
| 260 | /* leb128 type numbers have a potentially unlimited size. |
| 261 | The target of the following definitions of _sleb128_t and _uleb128_t |
| 262 | is to have efficient data types large enough to hold the leb128 type |
| 263 | numbers used in the unwind code. |
| 264 | Mostly these types will simply be defined to long and unsigned long |
| 265 | except when a unsigned long data type on the target machine is not |
| 266 | capable of storing a pointer. */ |
| 267 | |
| 268 | #if __SIZEOF_LONG__ >= __SIZEOF_POINTER__ |
| 269 | typedef long _sleb128_t; |
| 270 | typedef unsigned long _uleb128_t; |
| 271 | #elif __SIZEOF_LONG_LONG__ >= __SIZEOF_POINTER__ |
| 272 | typedef long long _sleb128_t; |
| 273 | typedef unsigned long long _uleb128_t; |
| 274 | #else |
| 275 | # error "What type shall we use for _sleb128_t?" |
| 276 | #endif |
| 277 | |
| 278 | #if defined (__SEH__) && !defined (__USING_SJLJ_EXCEPTIONS__) |
| 279 | /* Handles the mapping from SEH to GCC interfaces. */ |
| 280 | EXCEPTION_DISPOSITION _GCC_specific_handler (PEXCEPTION_RECORD, void *, |
| 281 | PCONTEXT, PDISPATCHER_CONTEXT, |
| 282 | _Unwind_Personality_Fn); |
| 283 | #endif |
| 284 | |
| 285 | #ifdef __cplusplus |
| 286 | } |
| 287 | #endif |
| 288 | |
| 289 | #ifndef HIDE_EXPORTS |
| 290 | #pragma GCC visibility pop |
| 291 | #endif |
| 292 | |
| 293 | #endif /* unwind.h */ |