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df4b504c | 1 | /* DWARF2 exception handling and frame unwind runtime interface routines. |
ac0c7fb1 | 2 | Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 |
3 | Free Software Foundation, Inc. | |
df4b504c | 4 | |
f12b58b3 | 5 | This file is part of GCC. |
df4b504c | 6 | |
f12b58b3 | 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 | |
df4b504c | 9 | the Free Software Foundation; either version 2, or (at your option) |
10 | any later version. | |
11 | ||
f12b58b3 | 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. | |
df4b504c | 16 | |
17 | You should have received a copy of the GNU General Public License | |
f12b58b3 | 18 | along with GCC; see the file COPYING. If not, write to the Free |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
df4b504c | 21 | |
22 | #include "tconfig.h" | |
23 | #include "tsystem.h" | |
805e22b2 | 24 | #include "coretypes.h" |
25 | #include "tm.h" | |
df4b504c | 26 | #include "unwind.h" |
27 | #include "gthr.h" | |
28 | ||
a1a7e9d5 | 29 | #ifdef __USING_SJLJ_EXCEPTIONS__ |
df4b504c | 30 | |
31 | #ifdef DONT_USE_BUILTIN_SETJMP | |
0ff18307 | 32 | #ifndef inhibit_libc |
df4b504c | 33 | #include <setjmp.h> |
34 | #else | |
0ff18307 | 35 | typedef void *jmp_buf[JMP_BUF_SIZE]; |
36 | extern void longjmp(jmp_buf, int) __attribute__((noreturn)); | |
37 | #endif | |
38 | #else | |
df4b504c | 39 | #define setjmp __builtin_setjmp |
40 | #define longjmp __builtin_longjmp | |
41 | #endif | |
42 | ||
43 | /* This structure is allocated on the stack of the target function. | |
44 | This must match the definition created in except.c:init_eh. */ | |
45 | struct SjLj_Function_Context | |
46 | { | |
47 | /* This is the chain through all registered contexts. It is | |
48 | filled in by _Unwind_SjLj_Register. */ | |
49 | struct SjLj_Function_Context *prev; | |
50 | ||
51 | /* This is assigned in by the target function before every call | |
52 | to the index of the call site in the lsda. It is assigned by | |
53 | the personality routine to the landing pad index. */ | |
54 | int call_site; | |
55 | ||
56 | /* This is how data is returned from the personality routine to | |
57 | the target function's handler. */ | |
58 | _Unwind_Word data[4]; | |
59 | ||
60 | /* These are filled in once by the target function before any | |
61 | exceptions are expected to be handled. */ | |
62 | _Unwind_Personality_Fn personality; | |
63 | void *lsda; | |
64 | ||
65 | #ifdef DONT_USE_BUILTIN_SETJMP | |
66 | /* We don't know what sort of alignment requirements the system | |
67 | jmp_buf has. We over estimated in except.c, and now we have | |
6c34d0c2 | 68 | to match that here just in case the system *didn't* have more |
df4b504c | 69 | restrictive requirements. */ |
70 | jmp_buf jbuf __attribute__((aligned)); | |
71 | #else | |
72 | void *jbuf[]; | |
73 | #endif | |
74 | }; | |
75 | ||
76 | struct _Unwind_Context | |
77 | { | |
78 | struct SjLj_Function_Context *fc; | |
79 | }; | |
80 | ||
6c34d0c2 | 81 | typedef struct |
df4b504c | 82 | { |
83 | _Unwind_Personality_Fn personality; | |
84 | } _Unwind_FrameState; | |
85 | ||
86 | \f | |
87 | /* Manage the chain of registered function contexts. */ | |
88 | ||
89 | /* Single threaded fallback chain. */ | |
90 | static struct SjLj_Function_Context *fc_static; | |
91 | ||
92 | #if __GTHREADS | |
93 | static __gthread_key_t fc_key; | |
94 | static int use_fc_key = -1; | |
95 | ||
df4b504c | 96 | static void |
97 | fc_key_init (void) | |
98 | { | |
805e22b2 | 99 | use_fc_key = __gthread_key_create (&fc_key, 0) == 0; |
df4b504c | 100 | } |
101 | ||
102 | static void | |
103 | fc_key_init_once (void) | |
104 | { | |
105 | static __gthread_once_t once = __GTHREAD_ONCE_INIT; | |
106 | if (__gthread_once (&once, fc_key_init) != 0 || use_fc_key < 0) | |
107 | use_fc_key = 0; | |
108 | } | |
109 | #endif | |
110 | ||
111 | void | |
112 | _Unwind_SjLj_Register (struct SjLj_Function_Context *fc) | |
113 | { | |
114 | #if __GTHREADS | |
115 | if (use_fc_key < 0) | |
116 | fc_key_init_once (); | |
117 | ||
118 | if (use_fc_key) | |
119 | { | |
120 | fc->prev = __gthread_getspecific (fc_key); | |
121 | __gthread_setspecific (fc_key, fc); | |
122 | } | |
123 | else | |
124 | #endif | |
125 | { | |
126 | fc->prev = fc_static; | |
127 | fc_static = fc; | |
128 | } | |
129 | } | |
130 | ||
131 | static inline struct SjLj_Function_Context * | |
132 | _Unwind_SjLj_GetContext (void) | |
133 | { | |
134 | #if __GTHREADS | |
135 | if (use_fc_key < 0) | |
136 | fc_key_init_once (); | |
137 | ||
138 | if (use_fc_key) | |
139 | return __gthread_getspecific (fc_key); | |
140 | #endif | |
141 | return fc_static; | |
142 | } | |
143 | ||
144 | static inline void | |
145 | _Unwind_SjLj_SetContext (struct SjLj_Function_Context *fc) | |
146 | { | |
147 | #if __GTHREADS | |
148 | if (use_fc_key < 0) | |
149 | fc_key_init_once (); | |
150 | ||
151 | if (use_fc_key) | |
152 | __gthread_setspecific (fc_key, fc); | |
153 | else | |
154 | #endif | |
155 | fc_static = fc; | |
156 | } | |
157 | ||
158 | void | |
159 | _Unwind_SjLj_Unregister (struct SjLj_Function_Context *fc) | |
160 | { | |
161 | _Unwind_SjLj_SetContext (fc->prev); | |
162 | } | |
163 | ||
164 | \f | |
165 | /* Get/set the return data value at INDEX in CONTEXT. */ | |
166 | ||
167 | _Unwind_Word | |
168 | _Unwind_GetGR (struct _Unwind_Context *context, int index) | |
169 | { | |
170 | return context->fc->data[index]; | |
171 | } | |
172 | ||
173 | void | |
174 | _Unwind_SetGR (struct _Unwind_Context *context, int index, _Unwind_Word val) | |
175 | { | |
176 | context->fc->data[index] = val; | |
177 | } | |
178 | ||
179 | /* Get the call-site index as saved in CONTEXT. */ | |
180 | ||
181 | _Unwind_Ptr | |
182 | _Unwind_GetIP (struct _Unwind_Context *context) | |
183 | { | |
184 | return context->fc->call_site + 1; | |
185 | } | |
186 | ||
187 | /* Set the return landing pad index in CONTEXT. */ | |
188 | ||
189 | void | |
190 | _Unwind_SetIP (struct _Unwind_Context *context, _Unwind_Ptr val) | |
191 | { | |
192 | context->fc->call_site = val - 1; | |
193 | } | |
194 | ||
195 | void * | |
196 | _Unwind_GetLanguageSpecificData (struct _Unwind_Context *context) | |
197 | { | |
198 | return context->fc->lsda; | |
199 | } | |
200 | ||
201 | _Unwind_Ptr | |
3b6bce1c | 202 | _Unwind_GetRegionStart (struct _Unwind_Context *context __attribute__((unused)) ) |
df4b504c | 203 | { |
204 | return 0; | |
205 | } | |
206 | ||
19799cdd | 207 | void * |
41acc81b | 208 | _Unwind_FindEnclosingFunction (void *pc) |
19799cdd | 209 | { |
210 | return NULL; | |
211 | } | |
212 | ||
934382cc | 213 | #ifndef __ia64__ |
214 | _Unwind_Ptr | |
3b6bce1c | 215 | _Unwind_GetDataRelBase (struct _Unwind_Context *context __attribute__((unused)) ) |
934382cc | 216 | { |
217 | return 0; | |
218 | } | |
219 | ||
220 | _Unwind_Ptr | |
3b6bce1c | 221 | _Unwind_GetTextRelBase (struct _Unwind_Context *context __attribute__((unused)) ) |
934382cc | 222 | { |
223 | return 0; | |
224 | } | |
225 | #endif | |
df4b504c | 226 | \f |
227 | static inline _Unwind_Reason_Code | |
228 | uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs) | |
229 | { | |
230 | if (context->fc == NULL) | |
231 | { | |
232 | fs->personality = NULL; | |
233 | return _URC_END_OF_STACK; | |
234 | } | |
235 | else | |
236 | { | |
237 | fs->personality = context->fc->personality; | |
238 | return _URC_NO_REASON; | |
239 | } | |
240 | } | |
241 | ||
242 | static inline void | |
243 | uw_update_context (struct _Unwind_Context *context, | |
244 | _Unwind_FrameState *fs __attribute__((unused)) ) | |
245 | { | |
246 | context->fc = context->fc->prev; | |
247 | } | |
248 | ||
6c34d0c2 | 249 | static inline void |
df4b504c | 250 | uw_init_context (struct _Unwind_Context *context) |
251 | { | |
252 | context->fc = _Unwind_SjLj_GetContext (); | |
253 | } | |
254 | ||
255 | /* ??? There appear to be bugs in integrate.c wrt __builtin_longjmp and | |
7800959d | 256 | virtual-stack-vars. An inline version of this segfaults on SPARC. */ |
ac0c7fb1 | 257 | #define uw_install_context(CURRENT, TARGET) \ |
258 | do \ | |
259 | { \ | |
260 | _Unwind_SjLj_SetContext ((TARGET)->fc); \ | |
261 | longjmp ((TARGET)->fc->jbuf, 1); \ | |
262 | } \ | |
263 | while (0) | |
df4b504c | 264 | |
265 | ||
266 | static inline _Unwind_Ptr | |
267 | uw_identify_context (struct _Unwind_Context *context) | |
268 | { | |
269 | return (_Unwind_Ptr) context->fc; | |
270 | } | |
271 | ||
272 | ||
273 | /* Play games with unwind symbols so that we can have call frame | |
274 | and sjlj symbols in the same shared library. Not that you can | |
275 | use them simultaneously... */ | |
276 | #define _Unwind_RaiseException _Unwind_SjLj_RaiseException | |
277 | #define _Unwind_ForcedUnwind _Unwind_SjLj_ForcedUnwind | |
278 | #define _Unwind_Resume _Unwind_SjLj_Resume | |
279 | ||
280 | #include "unwind.inc" | |
281 | ||
282 | #endif /* USING_SJLJ_EXCEPTIONS */ |