1 /* DWARF2 exception handling and frame unwind runtime interface routines.
2 Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
3 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GCC is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
15 License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
27 #ifdef __USING_SJLJ_EXCEPTIONS__
29 #ifdef DONT_USE_BUILTIN_SETJMP
33 typedef void *jmp_buf[JMP_BUF_SIZE
];
34 extern void longjmp(jmp_buf, int) __attribute__((noreturn
));
37 #define setjmp __builtin_setjmp
38 #define longjmp __builtin_longjmp
41 /* This structure is allocated on the stack of the target function.
42 This must match the definition created in except.c:init_eh. */
43 struct SjLj_Function_Context
45 /* This is the chain through all registered contexts. It is
46 filled in by _Unwind_SjLj_Register. */
47 struct SjLj_Function_Context
*prev
;
49 /* This is assigned in by the target function before every call
50 to the index of the call site in the lsda. It is assigned by
51 the personality routine to the landing pad index. */
54 /* This is how data is returned from the personality routine to
55 the target function's handler. */
58 /* These are filled in once by the target function before any
59 exceptions are expected to be handled. */
60 _Unwind_Personality_Fn personality
;
63 #ifdef DONT_USE_BUILTIN_SETJMP
64 /* We don't know what sort of alignment requirements the system
65 jmp_buf has. We over estimated in except.c, and now we have
66 to match that here just in case the system *didn't* have more
67 restrictive requirements. */
68 jmp_buf jbuf
__attribute__((aligned
));
74 struct _Unwind_Context
76 struct SjLj_Function_Context
*fc
;
81 _Unwind_Personality_Fn personality
;
85 /* Manage the chain of registered function contexts. */
87 /* Single threaded fallback chain. */
88 static struct SjLj_Function_Context
*fc_static
;
91 static __gthread_key_t fc_key
;
92 static int use_fc_key
= -1;
95 fc_key_dtor (void *ptr
)
97 __gthread_key_dtor (fc_key
, ptr
);
103 use_fc_key
= __gthread_key_create (&fc_key
, fc_key_dtor
) == 0;
107 fc_key_init_once (void)
109 static __gthread_once_t once
= __GTHREAD_ONCE_INIT
;
110 if (__gthread_once (&once
, fc_key_init
) != 0 || use_fc_key
< 0)
116 _Unwind_SjLj_Register (struct SjLj_Function_Context
*fc
)
124 fc
->prev
= __gthread_getspecific (fc_key
);
125 __gthread_setspecific (fc_key
, fc
);
130 fc
->prev
= fc_static
;
135 static inline struct SjLj_Function_Context
*
136 _Unwind_SjLj_GetContext (void)
143 return __gthread_getspecific (fc_key
);
149 _Unwind_SjLj_SetContext (struct SjLj_Function_Context
*fc
)
156 __gthread_setspecific (fc_key
, fc
);
163 _Unwind_SjLj_Unregister (struct SjLj_Function_Context
*fc
)
165 _Unwind_SjLj_SetContext (fc
->prev
);
169 /* Get/set the return data value at INDEX in CONTEXT. */
172 _Unwind_GetGR (struct _Unwind_Context
*context
, int index
)
174 return context
->fc
->data
[index
];
178 _Unwind_SetGR (struct _Unwind_Context
*context
, int index
, _Unwind_Word val
)
180 context
->fc
->data
[index
] = val
;
183 /* Get the call-site index as saved in CONTEXT. */
186 _Unwind_GetIP (struct _Unwind_Context
*context
)
188 return context
->fc
->call_site
+ 1;
191 /* Set the return landing pad index in CONTEXT. */
194 _Unwind_SetIP (struct _Unwind_Context
*context
, _Unwind_Ptr val
)
196 context
->fc
->call_site
= val
- 1;
200 _Unwind_GetLanguageSpecificData (struct _Unwind_Context
*context
)
202 return context
->fc
->lsda
;
206 _Unwind_GetRegionStart (struct _Unwind_Context
*context
__attribute__((unused
)) )
212 _Unwind_Find_Enclosing_Function (void *pc
)
219 _Unwind_GetDataRelBase (struct _Unwind_Context
*context
__attribute__((unused
)) )
225 _Unwind_GetTextRelBase (struct _Unwind_Context
*context
__attribute__((unused
)) )
231 static inline _Unwind_Reason_Code
232 uw_frame_state_for (struct _Unwind_Context
*context
, _Unwind_FrameState
*fs
)
234 if (context
->fc
== NULL
)
236 fs
->personality
= NULL
;
237 return _URC_END_OF_STACK
;
241 fs
->personality
= context
->fc
->personality
;
242 return _URC_NO_REASON
;
247 uw_update_context (struct _Unwind_Context
*context
,
248 _Unwind_FrameState
*fs
__attribute__((unused
)) )
250 context
->fc
= context
->fc
->prev
;
254 uw_init_context (struct _Unwind_Context
*context
)
256 context
->fc
= _Unwind_SjLj_GetContext ();
259 /* ??? There appear to be bugs in integrate.c wrt __builtin_longjmp and
260 virtual-stack-vars. An inline version of this segfaults on SPARC. */
261 #define uw_install_context(CURRENT, TARGET) \
264 _Unwind_SjLj_SetContext ((TARGET)->fc); \
265 longjmp ((TARGET)->fc->jbuf, 1); \
270 static inline _Unwind_Ptr
271 uw_identify_context (struct _Unwind_Context
*context
)
273 return (_Unwind_Ptr
) context
->fc
;
277 /* Play games with unwind symbols so that we can have call frame
278 and sjlj symbols in the same shared library. Not that you can
279 use them simultaneously... */
280 #define _Unwind_RaiseException _Unwind_SjLj_RaiseException
281 #define _Unwind_ForcedUnwind _Unwind_SjLj_ForcedUnwind
282 #define _Unwind_Resume _Unwind_SjLj_Resume
284 #include "unwind.inc"
286 #endif /* USING_SJLJ_EXCEPTIONS */