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b2e863b8 | 1 | /* SJLJ exception handling and frame unwind runtime interface routines. |
4f6c2131 | 2 | Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2006 |
a01da83b | 3 | Free Software Foundation, Inc. |
52a11cbf | 4 | |
1322177d | 5 | This file is part of GCC. |
52a11cbf | 6 | |
1322177d LB |
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 | |
52a11cbf RH |
9 | the Free Software Foundation; either version 2, or (at your option) |
10 | any later version. | |
11 | ||
1ee93c1b DJ |
12 | In addition to the permissions in the GNU General Public License, the |
13 | Free Software Foundation gives you unlimited permission to link the | |
14 | compiled version of this file into combinations with other programs, | |
15 | and to distribute those combinations without any restriction coming | |
16 | from the use of this file. (The General Public License restrictions | |
17 | do apply in other respects; for example, they cover modification of | |
18 | the file, and distribution when not linked into a combined | |
19 | executable.) | |
20 | ||
1322177d LB |
21 | GCC is distributed in the hope that it will be useful, but WITHOUT |
22 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
23 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public | |
24 | License for more details. | |
52a11cbf RH |
25 | |
26 | You should have received a copy of the GNU General Public License | |
1322177d | 27 | along with GCC; see the file COPYING. If not, write to the Free |
366ccddb KC |
28 | Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA |
29 | 02110-1301, USA. */ | |
52a11cbf RH |
30 | |
31 | #include "tconfig.h" | |
32 | #include "tsystem.h" | |
4977bab6 ZW |
33 | #include "coretypes.h" |
34 | #include "tm.h" | |
52a11cbf RH |
35 | #include "unwind.h" |
36 | #include "gthr.h" | |
37 | ||
0d24f4d1 | 38 | #ifdef __USING_SJLJ_EXCEPTIONS__ |
52a11cbf RH |
39 | |
40 | #ifdef DONT_USE_BUILTIN_SETJMP | |
9defc9b7 | 41 | #ifndef inhibit_libc |
52a11cbf RH |
42 | #include <setjmp.h> |
43 | #else | |
9defc9b7 RH |
44 | typedef void *jmp_buf[JMP_BUF_SIZE]; |
45 | extern void longjmp(jmp_buf, int) __attribute__((noreturn)); | |
46 | #endif | |
47 | #else | |
52a11cbf RH |
48 | #define longjmp __builtin_longjmp |
49 | #endif | |
50 | ||
4f6c2131 EB |
51 | /* The setjmp side is dealt with in the except.c file. */ |
52 | #undef setjmp | |
53 | #define setjmp setjmp_should_not_be_used_in_this_file | |
54 | ||
55 | ||
52a11cbf RH |
56 | /* This structure is allocated on the stack of the target function. |
57 | This must match the definition created in except.c:init_eh. */ | |
58 | struct SjLj_Function_Context | |
59 | { | |
60 | /* This is the chain through all registered contexts. It is | |
61 | filled in by _Unwind_SjLj_Register. */ | |
62 | struct SjLj_Function_Context *prev; | |
63 | ||
64 | /* This is assigned in by the target function before every call | |
65 | to the index of the call site in the lsda. It is assigned by | |
66 | the personality routine to the landing pad index. */ | |
67 | int call_site; | |
68 | ||
69 | /* This is how data is returned from the personality routine to | |
70 | the target function's handler. */ | |
71 | _Unwind_Word data[4]; | |
72 | ||
73 | /* These are filled in once by the target function before any | |
74 | exceptions are expected to be handled. */ | |
75 | _Unwind_Personality_Fn personality; | |
76 | void *lsda; | |
77 | ||
78 | #ifdef DONT_USE_BUILTIN_SETJMP | |
79 | /* We don't know what sort of alignment requirements the system | |
80 | jmp_buf has. We over estimated in except.c, and now we have | |
41077ce4 | 81 | to match that here just in case the system *didn't* have more |
52a11cbf RH |
82 | restrictive requirements. */ |
83 | jmp_buf jbuf __attribute__((aligned)); | |
84 | #else | |
85 | void *jbuf[]; | |
86 | #endif | |
87 | }; | |
88 | ||
89 | struct _Unwind_Context | |
90 | { | |
91 | struct SjLj_Function_Context *fc; | |
92 | }; | |
93 | ||
41077ce4 | 94 | typedef struct |
52a11cbf RH |
95 | { |
96 | _Unwind_Personality_Fn personality; | |
97 | } _Unwind_FrameState; | |
98 | ||
99 | \f | |
100 | /* Manage the chain of registered function contexts. */ | |
101 | ||
102 | /* Single threaded fallback chain. */ | |
103 | static struct SjLj_Function_Context *fc_static; | |
104 | ||
105 | #if __GTHREADS | |
106 | static __gthread_key_t fc_key; | |
107 | static int use_fc_key = -1; | |
108 | ||
52a11cbf RH |
109 | static void |
110 | fc_key_init (void) | |
111 | { | |
4977bab6 | 112 | use_fc_key = __gthread_key_create (&fc_key, 0) == 0; |
52a11cbf RH |
113 | } |
114 | ||
115 | static void | |
116 | fc_key_init_once (void) | |
117 | { | |
118 | static __gthread_once_t once = __GTHREAD_ONCE_INIT; | |
119 | if (__gthread_once (&once, fc_key_init) != 0 || use_fc_key < 0) | |
120 | use_fc_key = 0; | |
121 | } | |
122 | #endif | |
123 | ||
124 | void | |
125 | _Unwind_SjLj_Register (struct SjLj_Function_Context *fc) | |
126 | { | |
127 | #if __GTHREADS | |
128 | if (use_fc_key < 0) | |
129 | fc_key_init_once (); | |
130 | ||
131 | if (use_fc_key) | |
132 | { | |
133 | fc->prev = __gthread_getspecific (fc_key); | |
134 | __gthread_setspecific (fc_key, fc); | |
135 | } | |
136 | else | |
137 | #endif | |
138 | { | |
139 | fc->prev = fc_static; | |
140 | fc_static = fc; | |
141 | } | |
142 | } | |
143 | ||
144 | static inline struct SjLj_Function_Context * | |
145 | _Unwind_SjLj_GetContext (void) | |
146 | { | |
147 | #if __GTHREADS | |
148 | if (use_fc_key < 0) | |
149 | fc_key_init_once (); | |
150 | ||
151 | if (use_fc_key) | |
152 | return __gthread_getspecific (fc_key); | |
153 | #endif | |
154 | return fc_static; | |
155 | } | |
156 | ||
157 | static inline void | |
158 | _Unwind_SjLj_SetContext (struct SjLj_Function_Context *fc) | |
159 | { | |
160 | #if __GTHREADS | |
161 | if (use_fc_key < 0) | |
162 | fc_key_init_once (); | |
163 | ||
164 | if (use_fc_key) | |
165 | __gthread_setspecific (fc_key, fc); | |
166 | else | |
167 | #endif | |
168 | fc_static = fc; | |
169 | } | |
170 | ||
171 | void | |
172 | _Unwind_SjLj_Unregister (struct SjLj_Function_Context *fc) | |
173 | { | |
174 | _Unwind_SjLj_SetContext (fc->prev); | |
175 | } | |
176 | ||
177 | \f | |
178 | /* Get/set the return data value at INDEX in CONTEXT. */ | |
179 | ||
180 | _Unwind_Word | |
181 | _Unwind_GetGR (struct _Unwind_Context *context, int index) | |
182 | { | |
183 | return context->fc->data[index]; | |
184 | } | |
185 | ||
378683cf RH |
186 | /* Get the value of the CFA as saved in CONTEXT. */ |
187 | ||
188 | _Unwind_Word | |
525996eb | 189 | _Unwind_GetCFA (struct _Unwind_Context *context __attribute__((unused))) |
378683cf RH |
190 | { |
191 | /* ??? Ideally __builtin_setjmp places the CFA in the jmpbuf. */ | |
0e32bbcc DJ |
192 | |
193 | #ifndef DONT_USE_BUILTIN_SETJMP | |
194 | /* This is a crude imitation of the CFA: the saved stack pointer. | |
195 | This is roughly the CFA of the frame before CONTEXT. When using the | |
196 | DWARF-2 unwinder _Unwind_GetCFA returns the CFA of the frame described | |
197 | by CONTEXT instead; but for DWARF-2 the cleanups associated with | |
198 | CONTEXT have already been run, and for SJLJ they have not yet been. */ | |
199 | if (context->fc != NULL) | |
200 | return (_Unwind_Word) context->fc->jbuf[2]; | |
201 | #endif | |
202 | ||
203 | /* Otherwise we're out of luck for now. */ | |
d234bf61 | 204 | return (_Unwind_Word) 0; |
378683cf RH |
205 | } |
206 | ||
52a11cbf RH |
207 | void |
208 | _Unwind_SetGR (struct _Unwind_Context *context, int index, _Unwind_Word val) | |
209 | { | |
210 | context->fc->data[index] = val; | |
211 | } | |
212 | ||
213 | /* Get the call-site index as saved in CONTEXT. */ | |
214 | ||
215 | _Unwind_Ptr | |
216 | _Unwind_GetIP (struct _Unwind_Context *context) | |
217 | { | |
218 | return context->fc->call_site + 1; | |
219 | } | |
220 | ||
754e45a8 JJ |
221 | _Unwind_Ptr |
222 | _Unwind_GetIPInfo (struct _Unwind_Context *context, int *ip_before_insn) | |
223 | { | |
224 | *ip_before_insn = 0; | |
225 | return context->fc->call_site + 1; | |
226 | } | |
227 | ||
52a11cbf RH |
228 | /* Set the return landing pad index in CONTEXT. */ |
229 | ||
230 | void | |
231 | _Unwind_SetIP (struct _Unwind_Context *context, _Unwind_Ptr val) | |
232 | { | |
233 | context->fc->call_site = val - 1; | |
234 | } | |
235 | ||
236 | void * | |
237 | _Unwind_GetLanguageSpecificData (struct _Unwind_Context *context) | |
238 | { | |
239 | return context->fc->lsda; | |
240 | } | |
241 | ||
242 | _Unwind_Ptr | |
2adaabc6 | 243 | _Unwind_GetRegionStart (struct _Unwind_Context *context __attribute__((unused)) ) |
52a11cbf RH |
244 | { |
245 | return 0; | |
246 | } | |
247 | ||
5dafd282 | 248 | void * |
525996eb | 249 | _Unwind_FindEnclosingFunction (void *pc __attribute__((unused))) |
5dafd282 AH |
250 | { |
251 | return NULL; | |
252 | } | |
253 | ||
48941cb8 RH |
254 | #ifndef __ia64__ |
255 | _Unwind_Ptr | |
2adaabc6 | 256 | _Unwind_GetDataRelBase (struct _Unwind_Context *context __attribute__((unused)) ) |
48941cb8 RH |
257 | { |
258 | return 0; | |
259 | } | |
260 | ||
261 | _Unwind_Ptr | |
2adaabc6 | 262 | _Unwind_GetTextRelBase (struct _Unwind_Context *context __attribute__((unused)) ) |
48941cb8 RH |
263 | { |
264 | return 0; | |
265 | } | |
266 | #endif | |
52a11cbf RH |
267 | \f |
268 | static inline _Unwind_Reason_Code | |
269 | uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs) | |
270 | { | |
271 | if (context->fc == NULL) | |
272 | { | |
273 | fs->personality = NULL; | |
274 | return _URC_END_OF_STACK; | |
275 | } | |
276 | else | |
277 | { | |
278 | fs->personality = context->fc->personality; | |
279 | return _URC_NO_REASON; | |
280 | } | |
281 | } | |
282 | ||
283 | static inline void | |
284 | uw_update_context (struct _Unwind_Context *context, | |
285 | _Unwind_FrameState *fs __attribute__((unused)) ) | |
286 | { | |
287 | context->fc = context->fc->prev; | |
288 | } | |
289 | ||
60aef23e DJ |
290 | static void |
291 | uw_advance_context (struct _Unwind_Context *context, _Unwind_FrameState *fs) | |
292 | { | |
293 | _Unwind_SjLj_Unregister (context->fc); | |
294 | uw_update_context (context, fs); | |
295 | } | |
296 | ||
41077ce4 | 297 | static inline void |
52a11cbf RH |
298 | uw_init_context (struct _Unwind_Context *context) |
299 | { | |
300 | context->fc = _Unwind_SjLj_GetContext (); | |
301 | } | |
302 | ||
6de9cd9a DN |
303 | static void __attribute__((noreturn)) |
304 | uw_install_context (struct _Unwind_Context *current __attribute__((unused)), | |
305 | struct _Unwind_Context *target) | |
306 | { | |
307 | _Unwind_SjLj_SetContext (target->fc); | |
308 | longjmp (target->fc->jbuf, 1); | |
309 | } | |
52a11cbf RH |
310 | |
311 | static inline _Unwind_Ptr | |
312 | uw_identify_context (struct _Unwind_Context *context) | |
313 | { | |
314 | return (_Unwind_Ptr) context->fc; | |
315 | } | |
316 | ||
317 | ||
318 | /* Play games with unwind symbols so that we can have call frame | |
319 | and sjlj symbols in the same shared library. Not that you can | |
320 | use them simultaneously... */ | |
321 | #define _Unwind_RaiseException _Unwind_SjLj_RaiseException | |
322 | #define _Unwind_ForcedUnwind _Unwind_SjLj_ForcedUnwind | |
323 | #define _Unwind_Resume _Unwind_SjLj_Resume | |
a944ceb9 | 324 | #define _Unwind_Resume_or_Rethrow _Unwind_SjLj_Resume_or_Rethrow |
52a11cbf RH |
325 | |
326 | #include "unwind.inc" | |
327 | ||
328 | #endif /* USING_SJLJ_EXCEPTIONS */ |