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52a11cbf | 1 | /* DWARF2 exception handling and frame unwind runtime interface routines. |
cb25b0ce | 2 | Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003 |
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 | ||
1322177d LB |
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. | |
52a11cbf RH |
16 | |
17 | You should have received a copy of the GNU General Public License | |
1322177d LB |
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. */ | |
52a11cbf RH |
21 | |
22 | #include "tconfig.h" | |
23 | #include "tsystem.h" | |
4977bab6 ZW |
24 | #include "coretypes.h" |
25 | #include "tm.h" | |
52a11cbf RH |
26 | #include "dwarf2.h" |
27 | #include "unwind.h" | |
e1f9550a | 28 | #include "unwind-pe.h" |
52a11cbf RH |
29 | #include "unwind-dw2-fde.h" |
30 | #include "gthr.h" | |
31 | ||
32 | ||
0d24f4d1 | 33 | #ifndef __USING_SJLJ_EXCEPTIONS__ |
52a11cbf RH |
34 | |
35 | #ifndef STACK_GROWS_DOWNWARD | |
36 | #define STACK_GROWS_DOWNWARD 0 | |
37 | #else | |
38 | #undef STACK_GROWS_DOWNWARD | |
39 | #define STACK_GROWS_DOWNWARD 1 | |
40 | #endif | |
41 | ||
42 | /* A target can override (perhaps for backward compatibility) how | |
43 | many dwarf2 columns are unwound. */ | |
44 | #ifndef DWARF_FRAME_REGISTERS | |
45 | #define DWARF_FRAME_REGISTERS FIRST_PSEUDO_REGISTER | |
46 | #endif | |
47 | ||
919543ab AH |
48 | /* Dwarf frame registers used for pre gcc 3.0 compiled glibc. */ |
49 | #ifndef PRE_GCC3_DWARF_FRAME_REGISTERS | |
50 | #define PRE_GCC3_DWARF_FRAME_REGISTERS DWARF_FRAME_REGISTERS | |
51 | #endif | |
52 | ||
41f3a930 AH |
53 | #ifndef DWARF_REG_TO_UNWIND_COLUMN |
54 | #define DWARF_REG_TO_UNWIND_COLUMN(REGNO) (REGNO) | |
55 | #endif | |
56 | ||
81a60e6c JM |
57 | /* This is the register and unwind state for a particular frame. This |
58 | provides the information necessary to unwind up past a frame and return | |
59 | to its caller. */ | |
52a11cbf RH |
60 | struct _Unwind_Context |
61 | { | |
62 | void *reg[DWARF_FRAME_REGISTERS+1]; | |
63 | void *cfa; | |
64 | void *ra; | |
65 | void *lsda; | |
66 | struct dwarf_eh_bases bases; | |
67 | _Unwind_Word args_size; | |
68 | }; | |
69 | ||
70 | /* Byte size of every register managed by these routines. */ | |
71 | static unsigned char dwarf_reg_size_table[DWARF_FRAME_REGISTERS]; | |
72 | ||
73 | \f | |
74 | /* The result of interpreting the frame unwind info for a frame. | |
75 | This is all symbolic at this point, as none of the values can | |
76 | be resolved until the target pc is located. */ | |
77 | typedef struct | |
78 | { | |
79 | /* Each register save state can be described in terms of a CFA slot, | |
80 | another register, or a location expression. */ | |
81 | struct frame_state_reg_info | |
82 | { | |
83 | struct { | |
84 | union { | |
a9985a92 | 85 | _Unwind_Word reg; |
52a11cbf | 86 | _Unwind_Sword offset; |
e1f9550a | 87 | const unsigned char *exp; |
52a11cbf RH |
88 | } loc; |
89 | enum { | |
90 | REG_UNSAVED, | |
91 | REG_SAVED_OFFSET, | |
92 | REG_SAVED_REG, | |
93 | REG_SAVED_EXP, | |
94 | } how; | |
95 | } reg[DWARF_FRAME_REGISTERS+1]; | |
96 | ||
97 | /* Used to implement DW_CFA_remember_state. */ | |
98 | struct frame_state_reg_info *prev; | |
99 | } regs; | |
100 | ||
101 | /* The CFA can be described in terms of a reg+offset or a | |
102 | location expression. */ | |
103 | _Unwind_Sword cfa_offset; | |
104 | _Unwind_Word cfa_reg; | |
e1f9550a | 105 | const unsigned char *cfa_exp; |
52a11cbf RH |
106 | enum { |
107 | CFA_UNSET, | |
108 | CFA_REG_OFFSET, | |
109 | CFA_EXP, | |
110 | } cfa_how; | |
111 | ||
112 | /* The PC described by the current frame state. */ | |
113 | void *pc; | |
114 | ||
115 | /* The information we care about from the CIE/FDE. */ | |
116 | _Unwind_Personality_Fn personality; | |
a9985a92 JM |
117 | _Unwind_Sword data_align; |
118 | _Unwind_Word code_align; | |
52a11cbf | 119 | unsigned char retaddr_column; |
e1f9550a RH |
120 | unsigned char fde_encoding; |
121 | unsigned char lsda_encoding; | |
52a11cbf | 122 | unsigned char saw_z; |
5442cf15 | 123 | void *eh_ptr; |
52a11cbf RH |
124 | } _Unwind_FrameState; |
125 | \f | |
52a11cbf RH |
126 | /* Read unaligned data from the instruction buffer. */ |
127 | ||
128 | union unaligned | |
129 | { | |
130 | void *p; | |
131 | unsigned u2 __attribute__ ((mode (HI))); | |
132 | unsigned u4 __attribute__ ((mode (SI))); | |
133 | unsigned u8 __attribute__ ((mode (DI))); | |
134 | signed s2 __attribute__ ((mode (HI))); | |
135 | signed s4 __attribute__ ((mode (SI))); | |
136 | signed s8 __attribute__ ((mode (DI))); | |
137 | } __attribute__ ((packed)); | |
138 | ||
139 | static inline void * | |
e1f9550a | 140 | read_pointer (const void *p) { const union unaligned *up = p; return up->p; } |
52a11cbf RH |
141 | |
142 | static inline int | |
e9d1b155 | 143 | read_1u (const void *p) { return *(const unsigned char *) p; } |
52a11cbf RH |
144 | |
145 | static inline int | |
e9d1b155 | 146 | read_1s (const void *p) { return *(const signed char *) p; } |
52a11cbf RH |
147 | |
148 | static inline int | |
e1f9550a | 149 | read_2u (const void *p) { const union unaligned *up = p; return up->u2; } |
52a11cbf RH |
150 | |
151 | static inline int | |
e1f9550a | 152 | read_2s (const void *p) { const union unaligned *up = p; return up->s2; } |
52a11cbf RH |
153 | |
154 | static inline unsigned int | |
e1f9550a | 155 | read_4u (const void *p) { const union unaligned *up = p; return up->u4; } |
52a11cbf RH |
156 | |
157 | static inline int | |
e1f9550a | 158 | read_4s (const void *p) { const union unaligned *up = p; return up->s4; } |
52a11cbf RH |
159 | |
160 | static inline unsigned long | |
e1f9550a | 161 | read_8u (const void *p) { const union unaligned *up = p; return up->u8; } |
52a11cbf RH |
162 | |
163 | static inline unsigned long | |
e1f9550a | 164 | read_8s (const void *p) { const union unaligned *up = p; return up->s8; } |
52a11cbf RH |
165 | \f |
166 | /* Get the value of register REG as saved in CONTEXT. */ | |
167 | ||
168 | inline _Unwind_Word | |
169 | _Unwind_GetGR (struct _Unwind_Context *context, int index) | |
170 | { | |
41f3a930 | 171 | index = DWARF_REG_TO_UNWIND_COLUMN (index); |
52a11cbf RH |
172 | /* This will segfault if the register hasn't been saved. */ |
173 | return * (_Unwind_Word *) context->reg[index]; | |
174 | } | |
175 | ||
378683cf RH |
176 | /* Get the value of the CFA as saved in CONTEXT. */ |
177 | ||
178 | _Unwind_Word | |
179 | _Unwind_GetCFA (struct _Unwind_Context *context) | |
180 | { | |
ac24fc99 | 181 | return (_Unwind_Word)context->cfa; |
378683cf RH |
182 | } |
183 | ||
52a11cbf RH |
184 | /* Overwrite the saved value for register REG in CONTEXT with VAL. */ |
185 | ||
186 | inline void | |
187 | _Unwind_SetGR (struct _Unwind_Context *context, int index, _Unwind_Word val) | |
188 | { | |
41f3a930 | 189 | index = DWARF_REG_TO_UNWIND_COLUMN (index); |
52a11cbf RH |
190 | * (_Unwind_Word *) context->reg[index] = val; |
191 | } | |
192 | ||
41f3a930 AH |
193 | /* Get the pointer to a register INDEX as saved in CONTEXT. */ |
194 | ||
195 | static inline void * | |
196 | _Unwind_GetGRPtr (struct _Unwind_Context *context, int index) | |
197 | { | |
198 | index = DWARF_REG_TO_UNWIND_COLUMN (index); | |
199 | return context->reg[index]; | |
200 | } | |
201 | ||
202 | /* Set the pointer to a register INDEX as saved in CONTEXT. */ | |
203 | ||
204 | static inline void | |
205 | _Unwind_SetGRPtr (struct _Unwind_Context *context, int index, void *p) | |
206 | { | |
207 | index = DWARF_REG_TO_UNWIND_COLUMN (index); | |
208 | context->reg[index] = p; | |
209 | } | |
210 | ||
52a11cbf RH |
211 | /* Retrieve the return address for CONTEXT. */ |
212 | ||
213 | inline _Unwind_Ptr | |
214 | _Unwind_GetIP (struct _Unwind_Context *context) | |
215 | { | |
216 | return (_Unwind_Ptr) context->ra; | |
217 | } | |
218 | ||
219 | /* Overwrite the return address for CONTEXT with VAL. */ | |
220 | ||
221 | inline void | |
222 | _Unwind_SetIP (struct _Unwind_Context *context, _Unwind_Ptr val) | |
223 | { | |
224 | context->ra = (void *) val; | |
225 | } | |
226 | ||
227 | void * | |
228 | _Unwind_GetLanguageSpecificData (struct _Unwind_Context *context) | |
229 | { | |
230 | return context->lsda; | |
231 | } | |
232 | ||
233 | _Unwind_Ptr | |
234 | _Unwind_GetRegionStart (struct _Unwind_Context *context) | |
235 | { | |
236 | return (_Unwind_Ptr) context->bases.func; | |
237 | } | |
238 | ||
5dafd282 | 239 | void * |
5154b05d | 240 | _Unwind_FindEnclosingFunction (void *pc) |
5dafd282 AH |
241 | { |
242 | struct dwarf_eh_bases bases; | |
243 | struct dwarf_fde *fde = _Unwind_Find_FDE (pc-1, &bases); | |
244 | if (fde) | |
245 | return bases.func; | |
246 | else | |
247 | return NULL; | |
248 | } | |
249 | ||
2a1ee410 RH |
250 | #ifndef __ia64__ |
251 | _Unwind_Ptr | |
252 | _Unwind_GetDataRelBase (struct _Unwind_Context *context) | |
253 | { | |
254 | return (_Unwind_Ptr) context->bases.dbase; | |
255 | } | |
256 | ||
257 | _Unwind_Ptr | |
258 | _Unwind_GetTextRelBase (struct _Unwind_Context *context) | |
259 | { | |
260 | return (_Unwind_Ptr) context->bases.tbase; | |
261 | } | |
262 | #endif | |
52a11cbf RH |
263 | \f |
264 | /* Extract any interesting information from the CIE for the translation | |
265 | unit F belongs to. Return a pointer to the byte after the augmentation, | |
266 | or NULL if we encountered an undecipherable augmentation. */ | |
267 | ||
e1f9550a | 268 | static const unsigned char * |
52a11cbf RH |
269 | extract_cie_info (struct dwarf_cie *cie, struct _Unwind_Context *context, |
270 | _Unwind_FrameState *fs) | |
271 | { | |
e1f9550a RH |
272 | const unsigned char *aug = cie->augmentation; |
273 | const unsigned char *p = aug + strlen (aug) + 1; | |
274 | const unsigned char *ret = NULL; | |
a9985a92 | 275 | _Unwind_Word utmp; |
52a11cbf | 276 | |
5442cf15 MK |
277 | /* g++ v2 "eh" has pointer immediately following augmentation string, |
278 | so it must be handled first. */ | |
279 | if (aug[0] == 'e' && aug[1] == 'h') | |
280 | { | |
281 | fs->eh_ptr = read_pointer (p); | |
282 | p += sizeof (void *); | |
283 | aug += 2; | |
284 | } | |
285 | ||
52a11cbf RH |
286 | /* Immediately following the augmentation are the code and |
287 | data alignment and return address column. */ | |
a9985a92 JM |
288 | p = read_uleb128 (p, &fs->code_align); |
289 | p = read_sleb128 (p, &fs->data_align); | |
52a11cbf | 290 | fs->retaddr_column = *p++; |
e1f9550a | 291 | fs->lsda_encoding = DW_EH_PE_omit; |
52a11cbf RH |
292 | |
293 | /* If the augmentation starts with 'z', then a uleb128 immediately | |
294 | follows containing the length of the augmentation field following | |
295 | the size. */ | |
296 | if (*aug == 'z') | |
297 | { | |
a9985a92 JM |
298 | p = read_uleb128 (p, &utmp); |
299 | ret = p + utmp; | |
52a11cbf RH |
300 | |
301 | fs->saw_z = 1; | |
302 | ++aug; | |
303 | } | |
304 | ||
305 | /* Iterate over recognized augmentation subsequences. */ | |
306 | while (*aug != '\0') | |
307 | { | |
e1f9550a | 308 | /* "L" indicates a byte showing how the LSDA pointer is encoded. */ |
5442cf15 | 309 | if (aug[0] == 'L') |
e1f9550a RH |
310 | { |
311 | fs->lsda_encoding = *p++; | |
312 | aug += 1; | |
313 | } | |
314 | ||
315 | /* "R" indicates a byte indicating how FDE addresses are encoded. */ | |
52a11cbf RH |
316 | else if (aug[0] == 'R') |
317 | { | |
e1f9550a | 318 | fs->fde_encoding = *p++; |
52a11cbf RH |
319 | aug += 1; |
320 | } | |
321 | ||
e1f9550a | 322 | /* "P" indicates a personality routine in the CIE augmentation. */ |
52a11cbf RH |
323 | else if (aug[0] == 'P') |
324 | { | |
e1f9550a RH |
325 | p = read_encoded_value (context, *p, p + 1, |
326 | (_Unwind_Ptr *) &fs->personality); | |
52a11cbf RH |
327 | aug += 1; |
328 | } | |
329 | ||
330 | /* Otherwise we have an unknown augmentation string. | |
331 | Bail unless we saw a 'z' prefix. */ | |
332 | else | |
333 | return ret; | |
334 | } | |
335 | ||
336 | return ret ? ret : p; | |
337 | } | |
338 | ||
339 | ||
340 | /* Decode a DW_OP stack program. Return the top of stack. Push INITIAL | |
341 | onto the stack to start. */ | |
342 | ||
343 | static _Unwind_Word | |
e1f9550a | 344 | execute_stack_op (const unsigned char *op_ptr, const unsigned char *op_end, |
52a11cbf RH |
345 | struct _Unwind_Context *context, _Unwind_Word initial) |
346 | { | |
2d76cb1a | 347 | _Unwind_Word stack[64]; /* ??? Assume this is enough. */ |
52a11cbf RH |
348 | int stack_elt; |
349 | ||
350 | stack[0] = initial; | |
351 | stack_elt = 1; | |
352 | ||
353 | while (op_ptr < op_end) | |
354 | { | |
355 | enum dwarf_location_atom op = *op_ptr++; | |
a9985a92 JM |
356 | _Unwind_Word result, reg, utmp; |
357 | _Unwind_Sword offset, stmp; | |
52a11cbf RH |
358 | |
359 | switch (op) | |
360 | { | |
361 | case DW_OP_lit0: | |
362 | case DW_OP_lit1: | |
363 | case DW_OP_lit2: | |
364 | case DW_OP_lit3: | |
365 | case DW_OP_lit4: | |
366 | case DW_OP_lit5: | |
367 | case DW_OP_lit6: | |
368 | case DW_OP_lit7: | |
369 | case DW_OP_lit8: | |
370 | case DW_OP_lit9: | |
371 | case DW_OP_lit10: | |
372 | case DW_OP_lit11: | |
373 | case DW_OP_lit12: | |
374 | case DW_OP_lit13: | |
375 | case DW_OP_lit14: | |
376 | case DW_OP_lit15: | |
377 | case DW_OP_lit16: | |
378 | case DW_OP_lit17: | |
379 | case DW_OP_lit18: | |
380 | case DW_OP_lit19: | |
381 | case DW_OP_lit20: | |
382 | case DW_OP_lit21: | |
383 | case DW_OP_lit22: | |
384 | case DW_OP_lit23: | |
385 | case DW_OP_lit24: | |
386 | case DW_OP_lit25: | |
387 | case DW_OP_lit26: | |
388 | case DW_OP_lit27: | |
389 | case DW_OP_lit28: | |
390 | case DW_OP_lit29: | |
391 | case DW_OP_lit30: | |
392 | case DW_OP_lit31: | |
393 | result = op - DW_OP_lit0; | |
394 | break; | |
395 | ||
396 | case DW_OP_addr: | |
397 | result = (_Unwind_Word) (_Unwind_Ptr) read_pointer (op_ptr); | |
398 | op_ptr += sizeof (void *); | |
399 | break; | |
400 | ||
401 | case DW_OP_const1u: | |
402 | result = read_1u (op_ptr); | |
403 | op_ptr += 1; | |
404 | break; | |
405 | case DW_OP_const1s: | |
406 | result = read_1s (op_ptr); | |
407 | op_ptr += 1; | |
408 | break; | |
409 | case DW_OP_const2u: | |
410 | result = read_2u (op_ptr); | |
411 | op_ptr += 2; | |
412 | break; | |
413 | case DW_OP_const2s: | |
414 | result = read_2s (op_ptr); | |
415 | op_ptr += 2; | |
416 | break; | |
417 | case DW_OP_const4u: | |
418 | result = read_4u (op_ptr); | |
419 | op_ptr += 4; | |
420 | break; | |
421 | case DW_OP_const4s: | |
422 | result = read_4s (op_ptr); | |
423 | op_ptr += 4; | |
424 | break; | |
425 | case DW_OP_const8u: | |
426 | result = read_8u (op_ptr); | |
427 | op_ptr += 8; | |
428 | break; | |
429 | case DW_OP_const8s: | |
430 | result = read_8s (op_ptr); | |
431 | op_ptr += 8; | |
432 | break; | |
433 | case DW_OP_constu: | |
a9985a92 | 434 | op_ptr = read_uleb128 (op_ptr, &result); |
52a11cbf RH |
435 | break; |
436 | case DW_OP_consts: | |
a9985a92 JM |
437 | op_ptr = read_sleb128 (op_ptr, &stmp); |
438 | result = stmp; | |
52a11cbf RH |
439 | break; |
440 | ||
441 | case DW_OP_reg0: | |
442 | case DW_OP_reg1: | |
443 | case DW_OP_reg2: | |
444 | case DW_OP_reg3: | |
445 | case DW_OP_reg4: | |
446 | case DW_OP_reg5: | |
447 | case DW_OP_reg6: | |
448 | case DW_OP_reg7: | |
449 | case DW_OP_reg8: | |
450 | case DW_OP_reg9: | |
451 | case DW_OP_reg10: | |
452 | case DW_OP_reg11: | |
453 | case DW_OP_reg12: | |
454 | case DW_OP_reg13: | |
455 | case DW_OP_reg14: | |
456 | case DW_OP_reg15: | |
457 | case DW_OP_reg16: | |
458 | case DW_OP_reg17: | |
459 | case DW_OP_reg18: | |
460 | case DW_OP_reg19: | |
461 | case DW_OP_reg20: | |
462 | case DW_OP_reg21: | |
463 | case DW_OP_reg22: | |
464 | case DW_OP_reg23: | |
465 | case DW_OP_reg24: | |
466 | case DW_OP_reg25: | |
467 | case DW_OP_reg26: | |
468 | case DW_OP_reg27: | |
469 | case DW_OP_reg28: | |
470 | case DW_OP_reg29: | |
471 | case DW_OP_reg30: | |
472 | case DW_OP_reg31: | |
473 | result = _Unwind_GetGR (context, op - DW_OP_reg0); | |
474 | break; | |
475 | case DW_OP_regx: | |
a9985a92 | 476 | op_ptr = read_uleb128 (op_ptr, ®); |
52a11cbf RH |
477 | result = _Unwind_GetGR (context, reg); |
478 | break; | |
479 | ||
480 | case DW_OP_breg0: | |
481 | case DW_OP_breg1: | |
482 | case DW_OP_breg2: | |
483 | case DW_OP_breg3: | |
484 | case DW_OP_breg4: | |
485 | case DW_OP_breg5: | |
486 | case DW_OP_breg6: | |
487 | case DW_OP_breg7: | |
488 | case DW_OP_breg8: | |
489 | case DW_OP_breg9: | |
490 | case DW_OP_breg10: | |
491 | case DW_OP_breg11: | |
492 | case DW_OP_breg12: | |
493 | case DW_OP_breg13: | |
494 | case DW_OP_breg14: | |
495 | case DW_OP_breg15: | |
496 | case DW_OP_breg16: | |
497 | case DW_OP_breg17: | |
498 | case DW_OP_breg18: | |
499 | case DW_OP_breg19: | |
500 | case DW_OP_breg20: | |
501 | case DW_OP_breg21: | |
502 | case DW_OP_breg22: | |
503 | case DW_OP_breg23: | |
504 | case DW_OP_breg24: | |
505 | case DW_OP_breg25: | |
506 | case DW_OP_breg26: | |
507 | case DW_OP_breg27: | |
508 | case DW_OP_breg28: | |
509 | case DW_OP_breg29: | |
510 | case DW_OP_breg30: | |
511 | case DW_OP_breg31: | |
a9985a92 | 512 | op_ptr = read_sleb128 (op_ptr, &offset); |
52a11cbf RH |
513 | result = _Unwind_GetGR (context, op - DW_OP_breg0) + offset; |
514 | break; | |
515 | case DW_OP_bregx: | |
a9985a92 JM |
516 | op_ptr = read_uleb128 (op_ptr, ®); |
517 | op_ptr = read_sleb128 (op_ptr, &offset); | |
52a11cbf RH |
518 | result = _Unwind_GetGR (context, reg) + offset; |
519 | break; | |
520 | ||
521 | case DW_OP_dup: | |
522 | if (stack_elt < 1) | |
523 | abort (); | |
524 | result = stack[stack_elt - 1]; | |
525 | break; | |
526 | ||
527 | case DW_OP_drop: | |
528 | if (--stack_elt < 0) | |
529 | abort (); | |
530 | goto no_push; | |
531 | ||
532 | case DW_OP_pick: | |
533 | offset = *op_ptr++; | |
534 | if (offset >= stack_elt - 1) | |
535 | abort (); | |
536 | result = stack[stack_elt - 1 - offset]; | |
537 | break; | |
538 | ||
539 | case DW_OP_over: | |
540 | if (stack_elt < 2) | |
541 | abort (); | |
542 | result = stack[stack_elt - 2]; | |
543 | break; | |
544 | ||
545 | case DW_OP_rot: | |
546 | { | |
547 | _Unwind_Word t1, t2, t3; | |
548 | ||
549 | if (stack_elt < 3) | |
550 | abort (); | |
551 | t1 = stack[stack_elt - 1]; | |
552 | t2 = stack[stack_elt - 2]; | |
553 | t3 = stack[stack_elt - 3]; | |
554 | stack[stack_elt - 1] = t2; | |
555 | stack[stack_elt - 2] = t3; | |
556 | stack[stack_elt - 3] = t1; | |
557 | goto no_push; | |
558 | } | |
559 | ||
560 | case DW_OP_deref: | |
561 | case DW_OP_deref_size: | |
562 | case DW_OP_abs: | |
563 | case DW_OP_neg: | |
564 | case DW_OP_not: | |
565 | case DW_OP_plus_uconst: | |
566 | /* Unary operations. */ | |
567 | if (--stack_elt < 0) | |
568 | abort (); | |
569 | result = stack[stack_elt]; | |
570 | ||
571 | switch (op) | |
572 | { | |
573 | case DW_OP_deref: | |
574 | { | |
a01da83b | 575 | void *ptr = (void *) (_Unwind_Ptr) result; |
52a11cbf RH |
576 | result = (_Unwind_Ptr) read_pointer (ptr); |
577 | } | |
578 | break; | |
579 | ||
580 | case DW_OP_deref_size: | |
581 | { | |
a01da83b | 582 | void *ptr = (void *) (_Unwind_Ptr) result; |
52a11cbf RH |
583 | switch (*op_ptr++) |
584 | { | |
585 | case 1: | |
586 | result = read_1u (ptr); | |
587 | break; | |
588 | case 2: | |
589 | result = read_2u (ptr); | |
590 | break; | |
591 | case 4: | |
592 | result = read_4u (ptr); | |
593 | break; | |
594 | case 8: | |
595 | result = read_8u (ptr); | |
596 | break; | |
597 | default: | |
598 | abort (); | |
599 | } | |
600 | } | |
601 | break; | |
602 | ||
603 | case DW_OP_abs: | |
604 | if ((_Unwind_Sword) result < 0) | |
605 | result = -result; | |
606 | break; | |
607 | case DW_OP_neg: | |
608 | result = -result; | |
609 | break; | |
610 | case DW_OP_not: | |
611 | result = ~result; | |
612 | break; | |
613 | case DW_OP_plus_uconst: | |
a9985a92 JM |
614 | op_ptr = read_uleb128 (op_ptr, &utmp); |
615 | result += utmp; | |
52a11cbf | 616 | break; |
5ed3149c ZW |
617 | |
618 | default: | |
619 | abort (); | |
52a11cbf RH |
620 | } |
621 | break; | |
622 | ||
623 | case DW_OP_and: | |
624 | case DW_OP_div: | |
625 | case DW_OP_minus: | |
626 | case DW_OP_mod: | |
627 | case DW_OP_mul: | |
628 | case DW_OP_or: | |
629 | case DW_OP_plus: | |
630 | case DW_OP_le: | |
631 | case DW_OP_ge: | |
632 | case DW_OP_eq: | |
633 | case DW_OP_lt: | |
634 | case DW_OP_gt: | |
635 | case DW_OP_ne: | |
636 | { | |
637 | /* Binary operations. */ | |
638 | _Unwind_Word first, second; | |
41077ce4 | 639 | if ((stack_elt -= 2) < 0) |
5ed3149c | 640 | abort (); |
41077ce4 KH |
641 | second = stack[stack_elt]; |
642 | first = stack[stack_elt + 1]; | |
643 | ||
644 | switch (op) | |
645 | { | |
646 | case DW_OP_and: | |
647 | result = second & first; | |
648 | break; | |
649 | case DW_OP_div: | |
650 | result = (_Unwind_Sword) second / (_Unwind_Sword) first; | |
651 | break; | |
652 | case DW_OP_minus: | |
653 | result = second - first; | |
654 | break; | |
655 | case DW_OP_mod: | |
656 | result = (_Unwind_Sword) second % (_Unwind_Sword) first; | |
657 | break; | |
658 | case DW_OP_mul: | |
659 | result = second * first; | |
660 | break; | |
661 | case DW_OP_or: | |
662 | result = second | first; | |
663 | break; | |
664 | case DW_OP_plus: | |
665 | result = second + first; | |
666 | break; | |
667 | case DW_OP_shl: | |
668 | result = second << first; | |
669 | break; | |
670 | case DW_OP_shr: | |
671 | result = second >> first; | |
672 | break; | |
673 | case DW_OP_shra: | |
674 | result = (_Unwind_Sword) second >> first; | |
675 | break; | |
676 | case DW_OP_xor: | |
677 | result = second ^ first; | |
678 | break; | |
679 | case DW_OP_le: | |
680 | result = (_Unwind_Sword) first <= (_Unwind_Sword) second; | |
681 | break; | |
682 | case DW_OP_ge: | |
683 | result = (_Unwind_Sword) first >= (_Unwind_Sword) second; | |
684 | break; | |
685 | case DW_OP_eq: | |
686 | result = (_Unwind_Sword) first == (_Unwind_Sword) second; | |
687 | break; | |
688 | case DW_OP_lt: | |
689 | result = (_Unwind_Sword) first < (_Unwind_Sword) second; | |
690 | break; | |
691 | case DW_OP_gt: | |
692 | result = (_Unwind_Sword) first > (_Unwind_Sword) second; | |
693 | break; | |
694 | case DW_OP_ne: | |
695 | result = (_Unwind_Sword) first != (_Unwind_Sword) second; | |
696 | break; | |
697 | ||
698 | default: | |
699 | abort (); | |
700 | } | |
52a11cbf RH |
701 | } |
702 | break; | |
703 | ||
704 | case DW_OP_skip: | |
705 | offset = read_2s (op_ptr); | |
706 | op_ptr += 2; | |
707 | op_ptr += offset; | |
708 | goto no_push; | |
709 | ||
710 | case DW_OP_bra: | |
711 | if (--stack_elt < 0) | |
712 | abort (); | |
713 | offset = read_2s (op_ptr); | |
714 | op_ptr += 2; | |
715 | if (stack[stack_elt] != 0) | |
716 | op_ptr += offset; | |
717 | goto no_push; | |
718 | ||
719 | case DW_OP_nop: | |
720 | goto no_push; | |
721 | ||
722 | default: | |
723 | abort (); | |
724 | } | |
725 | ||
726 | /* Most things push a result value. */ | |
727 | if ((size_t) stack_elt >= sizeof(stack)/sizeof(*stack)) | |
728 | abort (); | |
9c80ff25 | 729 | stack[stack_elt++] = result; |
52a11cbf RH |
730 | no_push:; |
731 | } | |
732 | ||
733 | /* We were executing this program to get a value. It should be | |
734 | at top of stack. */ | |
735 | if (--stack_elt < 0) | |
736 | abort (); | |
737 | return stack[stack_elt]; | |
738 | } | |
739 | ||
740 | ||
741 | /* Decode DWARF 2 call frame information. Takes pointers the | |
742 | instruction sequence to decode, current register information and | |
743 | CIE info, and the PC range to evaluate. */ | |
744 | ||
745 | static void | |
e1f9550a RH |
746 | execute_cfa_program (const unsigned char *insn_ptr, |
747 | const unsigned char *insn_end, | |
748 | struct _Unwind_Context *context, | |
749 | _Unwind_FrameState *fs) | |
52a11cbf RH |
750 | { |
751 | struct frame_state_reg_info *unused_rs = NULL; | |
752 | ||
753 | /* Don't allow remember/restore between CIE and FDE programs. */ | |
754 | fs->regs.prev = NULL; | |
755 | ||
7d8ac293 JM |
756 | /* The comparison with the return address uses < rather than <= because |
757 | we are only interested in the effects of code before the call; for a | |
758 | noreturn function, the return address may point to unrelated code with | |
759 | a different stack configuration that we are not interested in. We | |
760 | assume that the call itself is unwind info-neutral; if not, or if | |
761 | there are delay instructions that adjust the stack, these must be | |
762 | reflected at the point immediately before the call insn. */ | |
763 | while (insn_ptr < insn_end && fs->pc < context->ra) | |
52a11cbf RH |
764 | { |
765 | unsigned char insn = *insn_ptr++; | |
a9985a92 JM |
766 | _Unwind_Word reg, utmp; |
767 | _Unwind_Sword offset, stmp; | |
52a11cbf | 768 | |
f0451e26 | 769 | if ((insn & 0xc0) == DW_CFA_advance_loc) |
52a11cbf | 770 | fs->pc += (insn & 0x3f) * fs->code_align; |
f0451e26 | 771 | else if ((insn & 0xc0) == DW_CFA_offset) |
52a11cbf RH |
772 | { |
773 | reg = insn & 0x3f; | |
a9985a92 | 774 | insn_ptr = read_uleb128 (insn_ptr, &utmp); |
e9d1b155 | 775 | offset = (_Unwind_Sword) utmp * fs->data_align; |
41f3a930 AH |
776 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how |
777 | = REG_SAVED_OFFSET; | |
778 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = offset; | |
52a11cbf | 779 | } |
f0451e26 | 780 | else if ((insn & 0xc0) == DW_CFA_restore) |
52a11cbf RH |
781 | { |
782 | reg = insn & 0x3f; | |
41f3a930 | 783 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how = REG_UNSAVED; |
52a11cbf RH |
784 | } |
785 | else switch (insn) | |
786 | { | |
787 | case DW_CFA_set_loc: | |
e1f9550a RH |
788 | insn_ptr = read_encoded_value (context, fs->fde_encoding, |
789 | insn_ptr, (_Unwind_Ptr *) &fs->pc); | |
52a11cbf RH |
790 | break; |
791 | ||
792 | case DW_CFA_advance_loc1: | |
9e800206 | 793 | fs->pc += read_1u (insn_ptr) * fs->code_align; |
52a11cbf RH |
794 | insn_ptr += 1; |
795 | break; | |
796 | case DW_CFA_advance_loc2: | |
9e800206 | 797 | fs->pc += read_2u (insn_ptr) * fs->code_align; |
52a11cbf RH |
798 | insn_ptr += 2; |
799 | break; | |
800 | case DW_CFA_advance_loc4: | |
9e800206 | 801 | fs->pc += read_4u (insn_ptr) * fs->code_align; |
52a11cbf RH |
802 | insn_ptr += 4; |
803 | break; | |
804 | ||
805 | case DW_CFA_offset_extended: | |
a9985a92 JM |
806 | insn_ptr = read_uleb128 (insn_ptr, ®); |
807 | insn_ptr = read_uleb128 (insn_ptr, &utmp); | |
e9d1b155 | 808 | offset = (_Unwind_Sword) utmp * fs->data_align; |
41f3a930 AH |
809 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how |
810 | = REG_SAVED_OFFSET; | |
811 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = offset; | |
52a11cbf RH |
812 | break; |
813 | ||
814 | case DW_CFA_restore_extended: | |
a9985a92 | 815 | insn_ptr = read_uleb128 (insn_ptr, ®); |
41f3a930 | 816 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN(reg)].how = REG_UNSAVED; |
52a11cbf RH |
817 | break; |
818 | ||
819 | case DW_CFA_undefined: | |
820 | case DW_CFA_same_value: | |
cb25b0ce BK |
821 | insn_ptr = read_uleb128 (insn_ptr, ®); |
822 | break; | |
823 | ||
52a11cbf RH |
824 | case DW_CFA_nop: |
825 | break; | |
826 | ||
827 | case DW_CFA_register: | |
828 | { | |
829 | _Unwind_Word reg2; | |
a9985a92 JM |
830 | insn_ptr = read_uleb128 (insn_ptr, ®); |
831 | insn_ptr = read_uleb128 (insn_ptr, ®2); | |
41f3a930 AH |
832 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how = REG_SAVED_REG; |
833 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.reg = reg2; | |
52a11cbf RH |
834 | } |
835 | break; | |
41077ce4 | 836 | |
52a11cbf RH |
837 | case DW_CFA_remember_state: |
838 | { | |
839 | struct frame_state_reg_info *new_rs; | |
840 | if (unused_rs) | |
841 | { | |
842 | new_rs = unused_rs; | |
843 | unused_rs = unused_rs->prev; | |
844 | } | |
845 | else | |
78b41166 | 846 | new_rs = __builtin_alloca (sizeof (struct frame_state_reg_info)); |
52a11cbf RH |
847 | |
848 | *new_rs = fs->regs; | |
849 | fs->regs.prev = new_rs; | |
850 | } | |
851 | break; | |
852 | ||
853 | case DW_CFA_restore_state: | |
854 | { | |
855 | struct frame_state_reg_info *old_rs = fs->regs.prev; | |
856 | fs->regs = *old_rs; | |
857 | old_rs->prev = unused_rs; | |
858 | unused_rs = old_rs; | |
859 | } | |
860 | break; | |
861 | ||
862 | case DW_CFA_def_cfa: | |
a9985a92 JM |
863 | insn_ptr = read_uleb128 (insn_ptr, &fs->cfa_reg); |
864 | insn_ptr = read_uleb128 (insn_ptr, &utmp); | |
865 | fs->cfa_offset = utmp; | |
52a11cbf RH |
866 | fs->cfa_how = CFA_REG_OFFSET; |
867 | break; | |
868 | ||
869 | case DW_CFA_def_cfa_register: | |
a9985a92 | 870 | insn_ptr = read_uleb128 (insn_ptr, &fs->cfa_reg); |
52a11cbf RH |
871 | fs->cfa_how = CFA_REG_OFFSET; |
872 | break; | |
873 | ||
874 | case DW_CFA_def_cfa_offset: | |
a9985a92 JM |
875 | insn_ptr = read_uleb128 (insn_ptr, &utmp); |
876 | fs->cfa_offset = utmp; | |
52a11cbf RH |
877 | /* cfa_how deliberately not set. */ |
878 | break; | |
879 | ||
880 | case DW_CFA_def_cfa_expression: | |
52a11cbf RH |
881 | fs->cfa_exp = insn_ptr; |
882 | fs->cfa_how = CFA_EXP; | |
9c80ff25 | 883 | insn_ptr = read_uleb128 (insn_ptr, &utmp); |
a9985a92 | 884 | insn_ptr += utmp; |
52a11cbf RH |
885 | break; |
886 | ||
887 | case DW_CFA_expression: | |
a9985a92 | 888 | insn_ptr = read_uleb128 (insn_ptr, ®); |
41f3a930 AH |
889 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how = REG_SAVED_EXP; |
890 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.exp = insn_ptr; | |
9c80ff25 | 891 | insn_ptr = read_uleb128 (insn_ptr, &utmp); |
a9985a92 | 892 | insn_ptr += utmp; |
52a11cbf RH |
893 | break; |
894 | ||
895 | /* From the 2.1 draft. */ | |
896 | case DW_CFA_offset_extended_sf: | |
a9985a92 JM |
897 | insn_ptr = read_uleb128 (insn_ptr, ®); |
898 | insn_ptr = read_sleb128 (insn_ptr, &stmp); | |
899 | offset = stmp * fs->data_align; | |
41f3a930 AH |
900 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how |
901 | = REG_SAVED_OFFSET; | |
902 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = offset; | |
52a11cbf | 903 | break; |
41077ce4 | 904 | |
52a11cbf | 905 | case DW_CFA_def_cfa_sf: |
a9985a92 JM |
906 | insn_ptr = read_uleb128 (insn_ptr, &fs->cfa_reg); |
907 | insn_ptr = read_sleb128 (insn_ptr, &fs->cfa_offset); | |
52a11cbf RH |
908 | fs->cfa_how = CFA_REG_OFFSET; |
909 | break; | |
910 | ||
911 | case DW_CFA_def_cfa_offset_sf: | |
a9985a92 | 912 | insn_ptr = read_sleb128 (insn_ptr, &fs->cfa_offset); |
52a11cbf RH |
913 | /* cfa_how deliberately not set. */ |
914 | break; | |
915 | ||
916 | case DW_CFA_GNU_window_save: | |
917 | /* ??? Hardcoded for SPARC register window configuration. */ | |
918 | for (reg = 16; reg < 32; ++reg) | |
919 | { | |
920 | fs->regs.reg[reg].how = REG_SAVED_OFFSET; | |
921 | fs->regs.reg[reg].loc.offset = (reg - 16) * sizeof (void *); | |
922 | } | |
923 | break; | |
924 | ||
925 | case DW_CFA_GNU_args_size: | |
a9985a92 | 926 | insn_ptr = read_uleb128 (insn_ptr, &context->args_size); |
52a11cbf RH |
927 | break; |
928 | ||
929 | case DW_CFA_GNU_negative_offset_extended: | |
930 | /* Obsoleted by DW_CFA_offset_extended_sf, but used by | |
931 | older PowerPC code. */ | |
a9985a92 JM |
932 | insn_ptr = read_uleb128 (insn_ptr, ®); |
933 | insn_ptr = read_uleb128 (insn_ptr, &utmp); | |
e9d1b155 | 934 | offset = (_Unwind_Word) utmp * fs->data_align; |
41f3a930 AH |
935 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how |
936 | = REG_SAVED_OFFSET; | |
937 | fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = -offset; | |
52a11cbf RH |
938 | break; |
939 | ||
940 | default: | |
941 | abort (); | |
942 | } | |
943 | } | |
944 | } | |
945 | \f | |
81a60e6c JM |
946 | /* Given the _Unwind_Context CONTEXT for a stack frame, look up the FDE for |
947 | its caller and decode it into FS. This function also sets the | |
948 | args_size and lsda members of CONTEXT, as they are really information | |
949 | about the caller's frame. */ | |
950 | ||
52a11cbf RH |
951 | static _Unwind_Reason_Code |
952 | uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs) | |
953 | { | |
954 | struct dwarf_fde *fde; | |
955 | struct dwarf_cie *cie; | |
e1f9550a | 956 | const unsigned char *aug, *insn, *end; |
52a11cbf RH |
957 | |
958 | memset (fs, 0, sizeof (*fs)); | |
959 | context->args_size = 0; | |
960 | context->lsda = 0; | |
961 | ||
962 | fde = _Unwind_Find_FDE (context->ra - 1, &context->bases); | |
963 | if (fde == NULL) | |
964 | { | |
965 | /* Couldn't find frame unwind info for this function. Try a | |
966 | target-specific fallback mechanism. This will necessarily | |
e3aafbad | 967 | not provide a personality routine or LSDA. */ |
52a11cbf RH |
968 | #ifdef MD_FALLBACK_FRAME_STATE_FOR |
969 | MD_FALLBACK_FRAME_STATE_FOR (context, fs, success); | |
970 | return _URC_END_OF_STACK; | |
971 | success: | |
972 | return _URC_NO_REASON; | |
973 | #else | |
974 | return _URC_END_OF_STACK; | |
975 | #endif | |
976 | } | |
977 | ||
e1f9550a | 978 | fs->pc = context->bases.func; |
52a11cbf RH |
979 | |
980 | cie = get_cie (fde); | |
981 | insn = extract_cie_info (cie, context, fs); | |
982 | if (insn == NULL) | |
983 | /* CIE contained unknown augmentation. */ | |
984 | return _URC_FATAL_PHASE1_ERROR; | |
985 | ||
986 | /* First decode all the insns in the CIE. */ | |
987 | end = (unsigned char *) next_fde ((struct dwarf_fde *) cie); | |
988 | execute_cfa_program (insn, end, context, fs); | |
989 | ||
990 | /* Locate augmentation for the fde. */ | |
e9d1b155 | 991 | aug = (unsigned char *) fde + sizeof (*fde); |
e1f9550a | 992 | aug += 2 * size_of_encoded_value (fs->fde_encoding); |
52a11cbf RH |
993 | insn = NULL; |
994 | if (fs->saw_z) | |
995 | { | |
a9985a92 | 996 | _Unwind_Word i; |
52a11cbf RH |
997 | aug = read_uleb128 (aug, &i); |
998 | insn = aug + i; | |
999 | } | |
e1f9550a RH |
1000 | if (fs->lsda_encoding != DW_EH_PE_omit) |
1001 | aug = read_encoded_value (context, fs->lsda_encoding, aug, | |
1002 | (_Unwind_Ptr *) &context->lsda); | |
52a11cbf RH |
1003 | |
1004 | /* Then the insns in the FDE up to our target PC. */ | |
1005 | if (insn == NULL) | |
1006 | insn = aug; | |
1007 | end = (unsigned char *) next_fde (fde); | |
1008 | execute_cfa_program (insn, end, context, fs); | |
1009 | ||
1010 | return _URC_NO_REASON; | |
1011 | } | |
5442cf15 MK |
1012 | \f |
1013 | typedef struct frame_state | |
1014 | { | |
1015 | void *cfa; | |
1016 | void *eh_ptr; | |
1017 | long cfa_offset; | |
1018 | long args_size; | |
919543ab | 1019 | long reg_or_offset[PRE_GCC3_DWARF_FRAME_REGISTERS+1]; |
5442cf15 MK |
1020 | unsigned short cfa_reg; |
1021 | unsigned short retaddr_column; | |
919543ab | 1022 | char saved[PRE_GCC3_DWARF_FRAME_REGISTERS+1]; |
5442cf15 MK |
1023 | } frame_state; |
1024 | ||
1025 | struct frame_state * __frame_state_for (void *, struct frame_state *); | |
1026 | ||
1027 | /* Called from pre-G++ 3.0 __throw to find the registers to restore for | |
1028 | a given PC_TARGET. The caller should allocate a local variable of | |
1029 | `struct frame_state' and pass its address to STATE_IN. */ | |
1030 | ||
1031 | struct frame_state * | |
1032 | __frame_state_for (void *pc_target, struct frame_state *state_in) | |
1033 | { | |
1034 | struct _Unwind_Context context; | |
1035 | _Unwind_FrameState fs; | |
1036 | int reg; | |
1037 | ||
1038 | memset (&context, 0, sizeof (struct _Unwind_Context)); | |
1039 | context.ra = pc_target + 1; | |
1040 | ||
1041 | if (uw_frame_state_for (&context, &fs) != _URC_NO_REASON) | |
1042 | return 0; | |
52a11cbf | 1043 | |
5442cf15 MK |
1044 | /* We have no way to pass a location expression for the CFA to our |
1045 | caller. It wouldn't understand it anyway. */ | |
1046 | if (fs.cfa_how == CFA_EXP) | |
1047 | return 0; | |
52a11cbf | 1048 | |
919543ab | 1049 | for (reg = 0; reg < PRE_GCC3_DWARF_FRAME_REGISTERS + 1; reg++) |
5442cf15 MK |
1050 | { |
1051 | state_in->saved[reg] = fs.regs.reg[reg].how; | |
1052 | switch (state_in->saved[reg]) | |
1053 | { | |
1054 | case REG_SAVED_REG: | |
1055 | state_in->reg_or_offset[reg] = fs.regs.reg[reg].loc.reg; | |
1056 | break; | |
1057 | case REG_SAVED_OFFSET: | |
1058 | state_in->reg_or_offset[reg] = fs.regs.reg[reg].loc.offset; | |
1059 | break; | |
1060 | default: | |
1061 | state_in->reg_or_offset[reg] = 0; | |
1062 | break; | |
1063 | } | |
1064 | } | |
1065 | ||
1066 | state_in->cfa_offset = fs.cfa_offset; | |
1067 | state_in->cfa_reg = fs.cfa_reg; | |
1068 | state_in->retaddr_column = fs.retaddr_column; | |
1069 | state_in->args_size = context.args_size; | |
1070 | state_in->eh_ptr = fs.eh_ptr; | |
1071 | ||
1072 | return state_in; | |
1073 | } | |
1074 | \f | |
52a11cbf RH |
1075 | static void |
1076 | uw_update_context_1 (struct _Unwind_Context *context, _Unwind_FrameState *fs) | |
1077 | { | |
1078 | struct _Unwind_Context orig_context = *context; | |
9c80ff25 | 1079 | _Unwind_Word tmp_sp; |
52a11cbf RH |
1080 | void *cfa; |
1081 | long i; | |
1082 | ||
9c80ff25 RH |
1083 | /* Special handling here: Many machines do not use a frame pointer, |
1084 | and track the CFA only through offsets from the stack pointer from | |
1085 | one frame to the next. In this case, the stack pointer is never | |
1086 | stored, so it has no saved address in the context. What we do | |
1087 | have is the CFA from the previous stack frame. | |
1088 | ||
1089 | In very special situations (such as unwind info for signal return), | |
1090 | there may be location expressions that use the stack pointer as well. | |
1091 | ||
1092 | Given that other unwind mechanisms generally won't work if you try | |
1093 | to represent stack pointer saves and restores directly, we don't | |
1094 | bother conditionalizing this at all. */ | |
1095 | tmp_sp = (_Unwind_Ptr) context->cfa; | |
1096 | _Unwind_SetGRPtr (&orig_context, __builtin_dwarf_sp_column (), &tmp_sp); | |
1097 | ||
52a11cbf RH |
1098 | /* Compute this frame's CFA. */ |
1099 | switch (fs->cfa_how) | |
1100 | { | |
1101 | case CFA_REG_OFFSET: | |
9c80ff25 | 1102 | cfa = (void *) (_Unwind_Ptr) _Unwind_GetGR (&orig_context, fs->cfa_reg); |
52a11cbf RH |
1103 | cfa += fs->cfa_offset; |
1104 | break; | |
1105 | ||
1106 | case CFA_EXP: | |
52a11cbf | 1107 | { |
e1f9550a | 1108 | const unsigned char *exp = fs->cfa_exp; |
a9985a92 | 1109 | _Unwind_Word len; |
52a11cbf RH |
1110 | |
1111 | exp = read_uleb128 (exp, &len); | |
1112 | cfa = (void *) (_Unwind_Ptr) | |
9c80ff25 | 1113 | execute_stack_op (exp, exp + len, &orig_context, 0); |
52a11cbf RH |
1114 | break; |
1115 | } | |
1116 | ||
1117 | default: | |
1118 | abort (); | |
1119 | } | |
1120 | context->cfa = cfa; | |
1121 | ||
1122 | /* Compute the addresses of all registers saved in this frame. */ | |
1123 | for (i = 0; i < DWARF_FRAME_REGISTERS + 1; ++i) | |
1124 | switch (fs->regs.reg[i].how) | |
1125 | { | |
1126 | case REG_UNSAVED: | |
1127 | break; | |
9c80ff25 | 1128 | |
52a11cbf | 1129 | case REG_SAVED_OFFSET: |
9c80ff25 RH |
1130 | _Unwind_SetGRPtr (context, i, |
1131 | (void *) (cfa + fs->regs.reg[i].loc.offset)); | |
52a11cbf | 1132 | break; |
9c80ff25 | 1133 | |
52a11cbf | 1134 | case REG_SAVED_REG: |
41f3a930 AH |
1135 | _Unwind_SetGRPtr |
1136 | (context, i, | |
1137 | _Unwind_GetGRPtr (&orig_context, fs->regs.reg[i].loc.reg)); | |
52a11cbf | 1138 | break; |
9c80ff25 | 1139 | |
52a11cbf RH |
1140 | case REG_SAVED_EXP: |
1141 | { | |
e1f9550a | 1142 | const unsigned char *exp = fs->regs.reg[i].loc.exp; |
a9985a92 | 1143 | _Unwind_Word len; |
52a11cbf RH |
1144 | _Unwind_Ptr val; |
1145 | ||
1146 | exp = read_uleb128 (exp, &len); | |
1147 | val = execute_stack_op (exp, exp + len, &orig_context, | |
1148 | (_Unwind_Ptr) cfa); | |
41f3a930 | 1149 | _Unwind_SetGRPtr (context, i, (void *) val); |
52a11cbf RH |
1150 | } |
1151 | break; | |
1152 | } | |
1153 | } | |
1154 | ||
81a60e6c JM |
1155 | /* CONTEXT describes the unwind state for a frame, and FS describes the FDE |
1156 | of its caller. Update CONTEXT to refer to the caller as well. Note | |
1157 | that the args_size and lsda members are not updated here, but later in | |
1158 | uw_frame_state_for. */ | |
1159 | ||
52a11cbf RH |
1160 | static void |
1161 | uw_update_context (struct _Unwind_Context *context, _Unwind_FrameState *fs) | |
1162 | { | |
1163 | uw_update_context_1 (context, fs); | |
1164 | ||
1165 | /* Compute the return address now, since the return address column | |
1166 | can change from frame to frame. */ | |
1167 | context->ra = __builtin_extract_return_addr | |
1168 | ((void *) (_Unwind_Ptr) _Unwind_GetGR (context, fs->retaddr_column)); | |
1169 | } | |
1170 | \f | |
1171 | /* Fill in CONTEXT for top-of-stack. The only valid registers at this | |
1172 | level will be the return address and the CFA. */ | |
41077ce4 | 1173 | |
a01da83b KH |
1174 | #define uw_init_context(CONTEXT) \ |
1175 | do \ | |
1176 | { \ | |
1177 | /* Do any necessary initialization to access arbitrary stack frames. \ | |
1178 | On the SPARC, this means flushing the register windows. */ \ | |
1179 | __builtin_unwind_init (); \ | |
1180 | uw_init_context_1 (CONTEXT, __builtin_dwarf_cfa (), \ | |
1181 | __builtin_return_address (0)); \ | |
1182 | } \ | |
1183 | while (0) | |
52a11cbf RH |
1184 | |
1185 | static void | |
1186 | uw_init_context_1 (struct _Unwind_Context *context, | |
1187 | void *outer_cfa, void *outer_ra) | |
1188 | { | |
1189 | void *ra = __builtin_extract_return_addr (__builtin_return_address (0)); | |
1190 | _Unwind_FrameState fs; | |
1191 | ||
1192 | memset (context, 0, sizeof (struct _Unwind_Context)); | |
1193 | context->ra = ra; | |
1194 | ||
1195 | if (uw_frame_state_for (context, &fs) != _URC_NO_REASON) | |
1196 | abort (); | |
1197 | ||
1198 | /* Force the frame state to use the known cfa value. */ | |
1199 | context->cfa = outer_cfa; | |
1200 | fs.cfa_how = CFA_REG_OFFSET; | |
9c80ff25 | 1201 | fs.cfa_reg = __builtin_dwarf_sp_column (); |
52a11cbf RH |
1202 | fs.cfa_offset = 0; |
1203 | ||
1204 | uw_update_context_1 (context, &fs); | |
1205 | ||
1206 | /* If the return address column was saved in a register in the | |
1207 | initialization context, then we can't see it in the given | |
1208 | call frame data. So have the initialization context tell us. */ | |
1209 | context->ra = __builtin_extract_return_addr (outer_ra); | |
1210 | } | |
1211 | ||
1212 | ||
1213 | /* Install TARGET into CURRENT so that we can return to it. This is a | |
1214 | macro because __builtin_eh_return must be invoked in the context of | |
1215 | our caller. */ | |
1216 | ||
a01da83b KH |
1217 | #define uw_install_context(CURRENT, TARGET) \ |
1218 | do \ | |
1219 | { \ | |
1220 | long offset = uw_install_context_1 ((CURRENT), (TARGET)); \ | |
1221 | void *handler = __builtin_frob_return_addr ((TARGET)->ra); \ | |
1222 | __builtin_eh_return (offset, handler); \ | |
1223 | } \ | |
1224 | while (0) | |
52a11cbf RH |
1225 | |
1226 | static inline void | |
1227 | init_dwarf_reg_size_table (void) | |
1228 | { | |
1229 | __builtin_init_dwarf_reg_size_table (dwarf_reg_size_table); | |
1230 | } | |
1231 | ||
1232 | static long | |
1233 | uw_install_context_1 (struct _Unwind_Context *current, | |
1234 | struct _Unwind_Context *target) | |
1235 | { | |
1236 | long i; | |
1237 | ||
1238 | #if __GTHREADS | |
1239 | { | |
1240 | static __gthread_once_t once_regsizes = __GTHREAD_ONCE_INIT; | |
1241 | if (__gthread_once (&once_regsizes, init_dwarf_reg_size_table) != 0 | |
1242 | || dwarf_reg_size_table[0] == 0) | |
1243 | init_dwarf_reg_size_table (); | |
1244 | } | |
1245 | #else | |
1246 | if (dwarf_reg_size_table[0] == 0) | |
1247 | init_dwarf_reg_size_table (); | |
1248 | #endif | |
1249 | ||
1250 | for (i = 0; i < DWARF_FRAME_REGISTERS; ++i) | |
1251 | { | |
1252 | void *c = current->reg[i]; | |
1253 | void *t = target->reg[i]; | |
41f3a930 | 1254 | |
52a11cbf RH |
1255 | if (t && c && t != c) |
1256 | memcpy (c, t, dwarf_reg_size_table[i]); | |
1257 | } | |
1258 | ||
1259 | /* We adjust SP by the difference between CURRENT and TARGET's CFA. */ | |
1260 | if (STACK_GROWS_DOWNWARD) | |
1261 | return target->cfa - current->cfa + target->args_size; | |
1262 | else | |
1263 | return current->cfa - target->cfa - target->args_size; | |
1264 | } | |
1265 | ||
1266 | static inline _Unwind_Ptr | |
1267 | uw_identify_context (struct _Unwind_Context *context) | |
1268 | { | |
1269 | return _Unwind_GetIP (context); | |
1270 | } | |
1271 | ||
1272 | ||
1273 | #include "unwind.inc" | |
1274 | ||
1275 | #endif /* !USING_SJLJ_EXCEPTIONS */ |