gcc/unwind-generic.h

   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
  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__(__word__)));
  47 typedef signed _Unwind_Sword __attribute__((__mode__(__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 /* 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.  */
 115 struct _Unwind_Context;
 116
 117 /* Raise an exception, passing along the given exception object.  */
 118 extern _Unwind_Reason_Code _Unwind_RaiseException (struct _Unwind_Exception *);
 119
 120 /* Raise an exception for forced unwinding.  */
 121
 122 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
 123      (int, _Unwind_Action, _Unwind_Exception_Class,
 124       struct _Unwind_Exception *, struct _Unwind_Context *, void *);
 125
 126 extern _Unwind_Reason_Code _Unwind_ForcedUnwind (struct _Unwind_Exception *,
 127                                                  _Unwind_Stop_Fn,
 128                                                  void *);
 129
 130 /* Helper to invoke the exception_cleanup routine.  */
 131 extern 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.  */
 135 extern 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.  */
 139 extern _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.  */
 144 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)
 145      (struct _Unwind_Context *, void *);
 146
 147 extern _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
 154 extern _Unwind_Word _Unwind_GetGR (struct _Unwind_Context *, int);
 155 extern void _Unwind_SetGR (struct _Unwind_Context *, int, _Unwind_Word);
 156
 157 extern _Unwind_Ptr _Unwind_GetIP (struct _Unwind_Context *);
 158 extern void _Unwind_SetIP (struct _Unwind_Context *, _Unwind_Ptr);
 159
 160 /* @@@ Retrieve the CFA of the given context.  */
 161 extern _Unwind_Word _Unwind_GetCFA (struct _Unwind_Context *);
 162
 163 extern void *_Unwind_GetLanguageSpecificData (struct _Unwind_Context *);
 164
 165 extern _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
 182 typedef _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
 189 struct SjLj_Function_Context;
 190 extern void _Unwind_SjLj_Register (struct SjLj_Function_Context *);
 191 extern void _Unwind_SjLj_Unregister (struct SjLj_Function_Context *);
 192
 193 extern _Unwind_Reason_Code _Unwind_SjLj_RaiseException
 194      (struct _Unwind_Exception *);
 195 extern _Unwind_Reason_Code _Unwind_SjLj_ForcedUnwind
 196      (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *);
 197 extern void _Unwind_SjLj_Resume (struct _Unwind_Exception *);
 198 extern _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
 207 static 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
 214 static 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.  */
 222 extern _Unwind_Word _Unwind_GetBSP (struct _Unwind_Context *);
 223 #else
 224 extern _Unwind_Ptr _Unwind_GetDataRelBase (struct _Unwind_Context *);
 225 extern _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.  */
 230 extern 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 */