1/* Exception handling and frame unwind runtime interface routines. 2 Copyright (C) 2001, 2003, 2004 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 39extern "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. */ 46typedef unsigned _Unwind_Word __attribute__((__mode__(__word__))); 47typedef signed _Unwind_Sword __attribute__((__mode__(__word__))); 48#if defined(__ia64__) && defined(__hpux__) 49typedef unsigned _Unwind_Ptr __attribute__((__mode__(__word__))); 50#else 51typedef unsigned _Unwind_Ptr __attribute__((__mode__(__pointer__))); 52#endif 53typedef 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. */ 59typedef 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. */ 63typedef 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 83struct _Unwind_Exception; 84 85typedef void (*_Unwind_Exception_Cleanup_Fn) (_Unwind_Reason_Code, 86 struct _Unwind_Exception *); 87 88struct _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. */ 103typedef 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/* This is an opaque type used to refer to a system-specific data 112 structure used by the system unwinder. This context is created and 113 destroyed by the system, and passed to the personality routine 114 during unwinding. */ 115struct _Unwind_Context; 116 117/* Raise an exception, passing along the given exception object. */ 118extern _Unwind_Reason_Code _Unwind_RaiseException (struct _Unwind_Exception *); 119 120/* Raise an exception for forced unwinding. */ 121 122typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn) 123 (int, _Unwind_Action, _Unwind_Exception_Class, 124 struct _Unwind_Exception *, struct _Unwind_Context *, void *); 125 126extern _Unwind_Reason_Code _Unwind_ForcedUnwind (struct _Unwind_Exception *, 127 _Unwind_Stop_Fn, 128 void *); 129 130/* Helper to invoke the exception_cleanup routine. */ 131extern void _Unwind_DeleteException (struct _Unwind_Exception *); 132 133/* Resume propagation of an existing exception. This is used after 134 e.g. executing cleanup code, and not to implement rethrowing. */ 135extern void _Unwind_Resume (struct _Unwind_Exception *); 136 137/* @@@ Resume propagation of an FORCE_UNWIND exception, or to rethrow 138 a normal exception that was handled. */ 139extern _Unwind_Reason_Code _Unwind_Resume_or_Rethrow (struct _Unwind_Exception *); 140 141/* @@@ Use unwind data to perform a stack backtrace. The trace callback 142 is called for every stack frame in the call chain, but no cleanup 143 actions are performed. */ 144typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn) 145 (struct _Unwind_Context *, void *); 146 147extern _Unwind_Reason_Code _Unwind_Backtrace (_Unwind_Trace_Fn, void *); 148 149/* These functions are used for communicating information about the unwind 150 context (i.e. the unwind descriptors and the user register state) between 151 the unwind library and the personality routine and landing pad. Only 152 selected registers maybe manipulated. */ 153 154extern _Unwind_Word _Unwind_GetGR (struct _Unwind_Context *, int); 155extern void _Unwind_SetGR (struct _Unwind_Context *, int, _Unwind_Word); 156 157extern _Unwind_Ptr _Unwind_GetIP (struct _Unwind_Context *); 158extern void _Unwind_SetIP (struct _Unwind_Context *, _Unwind_Ptr); 159 160/* @@@ Retrieve the CFA of the given context. */ 161extern _Unwind_Word _Unwind_GetCFA (struct _Unwind_Context *); 162 163extern void *_Unwind_GetLanguageSpecificData (struct _Unwind_Context *); 164 165extern _Unwind_Ptr _Unwind_GetRegionStart (struct _Unwind_Context *); 166 167 168/* The personality routine is the function in the C++ (or other language) 169 runtime library which serves as an interface between the system unwind 170 library and language-specific exception handling semantics. It is 171 specific to the code fragment described by an unwind info block, and 172 it is always referenced via the pointer in the unwind info block, and 173 hence it has no ABI-specified name. 174 175 Note that this implies that two different C++ implementations can 176 use different names, and have different contents in the language 177 specific data area. Moreover, that the language specific data 178 area contains no version info because name of the function invoked 179 provides more effective versioning by detecting at link time the 180 lack of code to handle the different data format. */ 181 182typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn) 183 (int, _Unwind_Action, _Unwind_Exception_Class, 184 struct _Unwind_Exception *, struct _Unwind_Context *); 185 186/* @@@ The following alternate entry points are for setjmp/longjmp 187 based unwinding. */ 188 189struct SjLj_Function_Context; 190extern void _Unwind_SjLj_Register (struct SjLj_Function_Context *); 191extern void _Unwind_SjLj_Unregister (struct SjLj_Function_Context *); 192 193extern _Unwind_Reason_Code _Unwind_SjLj_RaiseException 194 (struct _Unwind_Exception *); 195extern _Unwind_Reason_Code _Unwind_SjLj_ForcedUnwind 196 (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *); 197extern void _Unwind_SjLj_Resume (struct _Unwind_Exception *); 198extern _Unwind_Reason_Code _Unwind_SjLj_Resume_or_Rethrow (struct _Unwind_Exception *); 199 200/* @@@ The following provide access to the base addresses for text 201 and data-relative addressing in the LDSA. In order to stay link 202 compatible with the standard ABI for IA-64, we inline these. */ 203 204#ifdef __ia64__ 205#include <stdlib.h> 206 207static inline _Unwind_Ptr 208_Unwind_GetDataRelBase (struct _Unwind_Context *_C) 209{ 210 /* The GP is stored in R1. */ 211 return _Unwind_GetGR (_C, 1); 212} 213 214static inline _Unwind_Ptr 215_Unwind_GetTextRelBase (struct _Unwind_Context *_C __attribute__ ((__unused__))) 216{ 217 abort (); 218 return 0; 219} 220 221/* @@@ Retrieve the Backing Store Pointer of the given context. */ 222extern _Unwind_Word _Unwind_GetBSP (struct _Unwind_Context *); 223#else 224extern _Unwind_Ptr _Unwind_GetDataRelBase (struct _Unwind_Context *); 225extern _Unwind_Ptr _Unwind_GetTextRelBase (struct _Unwind_Context *); 226#endif 227 228/* @@@ Given an address, return the entry point of the function that 229 contains it. */ 230extern void * _Unwind_FindEnclosingFunction (void *pc); 231 232#ifdef __cplusplus 233} 234#endif 235 236#ifndef HIDE_EXPORTS 237#pragma GCC visibility pop 238#endif 239 240#endif /* unwind.h */ 241