1 //===-------------------------- DwarfInstructions.hpp ---------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //
9 //  Processor specific interpretation of DWARF unwind info.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef __DWARF_INSTRUCTIONS_HPP__
14 #define __DWARF_INSTRUCTIONS_HPP__
15 
16 #include <stdint.h>
17 #include <stdio.h>
18 #include <stdlib.h>
19 
20 #include "dwarf2.h"
21 #include "Registers.hpp"
22 #include "DwarfParser.hpp"
23 #include "config.h"
24 
25 
26 namespace libunwind {
27 
28 
29 /// DwarfInstructions maps abtract DWARF unwind instructions to a particular
30 /// architecture
31 template <typename A, typename R>
32 class DwarfInstructions {
33 public:
34   typedef typename A::pint_t pint_t;
35   typedef typename A::sint_t sint_t;
36 
37   static int stepWithDwarf(A &addressSpace, pint_t pc, pint_t fdeStart,
38                            R &registers);
39 
40 private:
41 
42   enum {
43     DW_X86_64_RET_ADDR = 16
44   };
45 
46   enum {
47     DW_X86_RET_ADDR = 8
48   };
49 
50   typedef typename CFI_Parser<A>::RegisterLocation  RegisterLocation;
51   typedef typename CFI_Parser<A>::PrologInfo        PrologInfo;
52   typedef typename CFI_Parser<A>::FDE_Info          FDE_Info;
53   typedef typename CFI_Parser<A>::CIE_Info          CIE_Info;
54 
55   static pint_t evaluateExpression(pint_t expression, A &addressSpace,
56                                    const R &registers,
57                                    pint_t initialStackValue);
58   static pint_t getSavedRegister(A &addressSpace, const R &registers,
59                                  pint_t cfa, const RegisterLocation &savedReg);
60   static double getSavedFloatRegister(A &addressSpace, const R &registers,
61                                   pint_t cfa, const RegisterLocation &savedReg);
62   static v128 getSavedVectorRegister(A &addressSpace, const R &registers,
63                                   pint_t cfa, const RegisterLocation &savedReg);
64 
getCFA(A & addressSpace,const PrologInfo & prolog,const R & registers)65   static pint_t getCFA(A &addressSpace, const PrologInfo &prolog,
66                        const R &registers) {
67     if (prolog.cfaRegister != 0)
68       return (pint_t)((sint_t)registers.getRegister((int)prolog.cfaRegister) +
69              prolog.cfaRegisterOffset);
70     if (prolog.cfaExpression != 0)
71       return evaluateExpression((pint_t)prolog.cfaExpression, addressSpace,
72                                 registers, 0);
73     assert(0 && "getCFA(): unknown location");
74     __builtin_unreachable();
75   }
76 };
77 
78 
79 template <typename A, typename R>
getSavedRegister(A & addressSpace,const R & registers,pint_t cfa,const RegisterLocation & savedReg)80 typename A::pint_t DwarfInstructions<A, R>::getSavedRegister(
81     A &addressSpace, const R &registers, pint_t cfa,
82     const RegisterLocation &savedReg) {
83   switch (savedReg.location) {
84   case CFI_Parser<A>::kRegisterInCFA:
85     return addressSpace.getRegister(cfa + (pint_t)savedReg.value);
86 
87   case CFI_Parser<A>::kRegisterAtExpression:
88     return addressSpace.getRegister(
89         evaluateExpression((pint_t)savedReg.value, addressSpace,
90                             registers, cfa));
91 
92   case CFI_Parser<A>::kRegisterIsExpression:
93     return evaluateExpression((pint_t)savedReg.value, addressSpace,
94                               registers, cfa);
95 
96   case CFI_Parser<A>::kRegisterInRegister:
97     return registers.getRegister((int)savedReg.value);
98 
99   case CFI_Parser<A>::kRegisterUnused:
100   case CFI_Parser<A>::kRegisterOffsetFromCFA:
101     // FIX ME
102     break;
103   }
104   _LIBUNWIND_ABORT("unsupported restore location for register");
105 }
106 
107 template <typename A, typename R>
getSavedFloatRegister(A & addressSpace,const R & registers,pint_t cfa,const RegisterLocation & savedReg)108 double DwarfInstructions<A, R>::getSavedFloatRegister(
109     A &addressSpace, const R &registers, pint_t cfa,
110     const RegisterLocation &savedReg) {
111   switch (savedReg.location) {
112   case CFI_Parser<A>::kRegisterInCFA:
113     return addressSpace.getDouble(cfa + (pint_t)savedReg.value);
114 
115   case CFI_Parser<A>::kRegisterAtExpression:
116     return addressSpace.getDouble(
117         evaluateExpression((pint_t)savedReg.value, addressSpace,
118                             registers, cfa));
119 
120   case CFI_Parser<A>::kRegisterIsExpression:
121   case CFI_Parser<A>::kRegisterUnused:
122   case CFI_Parser<A>::kRegisterOffsetFromCFA:
123   case CFI_Parser<A>::kRegisterInRegister:
124     // FIX ME
125     break;
126   }
127   _LIBUNWIND_ABORT("unsupported restore location for float register");
128 }
129 
130 template <typename A, typename R>
getSavedVectorRegister(A & addressSpace,const R & registers,pint_t cfa,const RegisterLocation & savedReg)131 v128 DwarfInstructions<A, R>::getSavedVectorRegister(
132     A &addressSpace, const R &registers, pint_t cfa,
133     const RegisterLocation &savedReg) {
134   switch (savedReg.location) {
135   case CFI_Parser<A>::kRegisterInCFA:
136     return addressSpace.getVector(cfa + (pint_t)savedReg.value);
137 
138   case CFI_Parser<A>::kRegisterAtExpression:
139     return addressSpace.getVector(
140         evaluateExpression((pint_t)savedReg.value, addressSpace,
141                             registers, cfa));
142 
143   case CFI_Parser<A>::kRegisterIsExpression:
144   case CFI_Parser<A>::kRegisterUnused:
145   case CFI_Parser<A>::kRegisterOffsetFromCFA:
146   case CFI_Parser<A>::kRegisterInRegister:
147     // FIX ME
148     break;
149   }
150   _LIBUNWIND_ABORT("unsupported restore location for vector register");
151 }
152 
153 template <typename A, typename R>
stepWithDwarf(A & addressSpace,pint_t pc,pint_t fdeStart,R & registers)154 int DwarfInstructions<A, R>::stepWithDwarf(A &addressSpace, pint_t pc,
155                                            pint_t fdeStart, R &registers) {
156   FDE_Info fdeInfo;
157   CIE_Info cieInfo;
158   if (CFI_Parser<A>::decodeFDE(addressSpace, fdeStart, &fdeInfo,
159                                &cieInfo) == NULL) {
160     PrologInfo prolog;
161     if (CFI_Parser<A>::parseFDEInstructions(addressSpace, fdeInfo, cieInfo, pc,
162                                             R::getArch(), &prolog)) {
163       // get pointer to cfa (architecture specific)
164       pint_t cfa = getCFA(addressSpace, prolog, registers);
165 
166        // restore registers that DWARF says were saved
167       R newRegisters = registers;
168       pint_t returnAddress = 0;
169       const int lastReg = R::lastDwarfRegNum();
170       assert(static_cast<int>(CFI_Parser<A>::kMaxRegisterNumber) >= lastReg &&
171              "register range too large");
172       assert(lastReg >= (int)cieInfo.returnAddressRegister &&
173              "register range does not contain return address register");
174       for (int i = 0; i <= lastReg; ++i) {
175         if (prolog.savedRegisters[i].location !=
176             CFI_Parser<A>::kRegisterUnused) {
177           if (registers.validFloatRegister(i))
178             newRegisters.setFloatRegister(
179                 i, getSavedFloatRegister(addressSpace, registers, cfa,
180                                          prolog.savedRegisters[i]));
181           else if (registers.validVectorRegister(i))
182             newRegisters.setVectorRegister(
183                 i, getSavedVectorRegister(addressSpace, registers, cfa,
184                                           prolog.savedRegisters[i]));
185           else if (i == (int)cieInfo.returnAddressRegister)
186             returnAddress = getSavedRegister(addressSpace, registers, cfa,
187                                              prolog.savedRegisters[i]);
188           else if (registers.validRegister(i))
189             newRegisters.setRegister(
190                 i, getSavedRegister(addressSpace, registers, cfa,
191                                     prolog.savedRegisters[i]));
192           else
193             return UNW_EBADREG;
194         }
195       }
196 
197       // By definition, the CFA is the stack pointer at the call site, so
198       // restoring SP means setting it to CFA.
199       newRegisters.setSP(cfa);
200 
201 #if defined(_LIBUNWIND_TARGET_AARCH64)
202       // If the target is aarch64 then the return address may have been signed
203       // using the v8.3 pointer authentication extensions. The original
204       // return address needs to be authenticated before the return address is
205       // restored. autia1716 is used instead of autia as autia1716 assembles
206       // to a NOP on pre-v8.3a architectures.
207       if ((R::getArch() == REGISTERS_ARM64) &&
208           prolog.savedRegisters[UNW_ARM64_RA_SIGN_STATE].value) {
209 #if !defined(_LIBUNWIND_IS_NATIVE_ONLY)
210         return UNW_ECROSSRASIGNING;
211 #else
212         register unsigned long long x17 __asm("x17") = returnAddress;
213         register unsigned long long x16 __asm("x16") = cfa;
214 
215         // These are the autia1716/autib1716 instructions. The hint instructions
216         // are used here as gcc does not assemble autia1716/autib1716 for pre
217         // armv8.3a targets.
218         if (cieInfo.addressesSignedWithBKey)
219           asm("hint 0xe" : "+r"(x17) : "r"(x16)); // autib1716
220         else
221           asm("hint 0xc" : "+r"(x17) : "r"(x16)); // autia1716
222         returnAddress = x17;
223 #endif
224       }
225 #endif
226 
227 #if defined(_LIBUNWIND_TARGET_SPARC)
228       if (R::getArch() == REGISTERS_SPARC) {
229         // Skip call site instruction and delay slot
230         returnAddress += 8;
231         // Skip unimp instruction if function returns a struct
232         if ((addressSpace.get32(returnAddress) & 0xC1C00000) == 0)
233           returnAddress += 4;
234       }
235 #endif
236 
237 #if defined(_LIBUNWIND_TARGET_PPC64)
238 #define PPC64_ELFV1_R2_LOAD_INST_ENCODING 0xe8410028u // ld r2,40(r1)
239 #define PPC64_ELFV1_R2_OFFSET 40
240 #define PPC64_ELFV2_R2_LOAD_INST_ENCODING 0xe8410018u // ld r2,24(r1)
241 #define PPC64_ELFV2_R2_OFFSET 24
242       // If the instruction at return address is a TOC (r2) restore,
243       // then r2 was saved and needs to be restored.
244       // ELFv2 ABI specifies that the TOC Pointer must be saved at SP + 24,
245       // while in ELFv1 ABI it is saved at SP + 40.
246       if (R::getArch() == REGISTERS_PPC64 && returnAddress != 0) {
247         pint_t sp = newRegisters.getRegister(UNW_REG_SP);
248         pint_t r2 = 0;
249         switch (addressSpace.get32(returnAddress)) {
250         case PPC64_ELFV1_R2_LOAD_INST_ENCODING:
251           r2 = addressSpace.get64(sp + PPC64_ELFV1_R2_OFFSET);
252           break;
253         case PPC64_ELFV2_R2_LOAD_INST_ENCODING:
254           r2 = addressSpace.get64(sp + PPC64_ELFV2_R2_OFFSET);
255           break;
256         }
257         if (r2)
258           newRegisters.setRegister(UNW_PPC64_R2, r2);
259       }
260 #endif
261 
262       // Return address is address after call site instruction, so setting IP to
263       // that does simualates a return.
264       newRegisters.setIP(returnAddress);
265 
266       // Simulate the step by replacing the register set with the new ones.
267       registers = newRegisters;
268 
269       return UNW_STEP_SUCCESS;
270     }
271   }
272   return UNW_EBADFRAME;
273 }
274 
275 template <typename A, typename R>
276 typename A::pint_t
evaluateExpression(pint_t expression,A & addressSpace,const R & registers,pint_t initialStackValue)277 DwarfInstructions<A, R>::evaluateExpression(pint_t expression, A &addressSpace,
278                                             const R &registers,
279                                             pint_t initialStackValue) {
280   const bool log = false;
281   pint_t p = expression;
282   pint_t expressionEnd = expression + 20; // temp, until len read
283   pint_t length = (pint_t)addressSpace.getULEB128(p, expressionEnd);
284   expressionEnd = p + length;
285   if (log)
286     fprintf(stderr, "evaluateExpression(): length=%" PRIu64 "\n",
287             (uint64_t)length);
288   pint_t stack[100];
289   pint_t *sp = stack;
290   *(++sp) = initialStackValue;
291 
292   while (p < expressionEnd) {
293     if (log) {
294       for (pint_t *t = sp; t > stack; --t) {
295         fprintf(stderr, "sp[] = 0x%" PRIx64 "\n", (uint64_t)(*t));
296       }
297     }
298     uint8_t opcode = addressSpace.get8(p++);
299     sint_t svalue, svalue2;
300     pint_t value;
301     uint32_t reg;
302     switch (opcode) {
303     case DW_OP_addr:
304       // push immediate address sized value
305       value = addressSpace.getP(p);
306       p += sizeof(pint_t);
307       *(++sp) = value;
308       if (log)
309         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
310       break;
311 
312     case DW_OP_deref:
313       // pop stack, dereference, push result
314       value = *sp--;
315       *(++sp) = addressSpace.getP(value);
316       if (log)
317         fprintf(stderr, "dereference 0x%" PRIx64 "\n", (uint64_t)value);
318       break;
319 
320     case DW_OP_const1u:
321       // push immediate 1 byte value
322       value = addressSpace.get8(p);
323       p += 1;
324       *(++sp) = value;
325       if (log)
326         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
327       break;
328 
329     case DW_OP_const1s:
330       // push immediate 1 byte signed value
331       svalue = (int8_t) addressSpace.get8(p);
332       p += 1;
333       *(++sp) = (pint_t)svalue;
334       if (log)
335         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue);
336       break;
337 
338     case DW_OP_const2u:
339       // push immediate 2 byte value
340       value = addressSpace.get16(p);
341       p += 2;
342       *(++sp) = value;
343       if (log)
344         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
345       break;
346 
347     case DW_OP_const2s:
348       // push immediate 2 byte signed value
349       svalue = (int16_t) addressSpace.get16(p);
350       p += 2;
351       *(++sp) = (pint_t)svalue;
352       if (log)
353         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue);
354       break;
355 
356     case DW_OP_const4u:
357       // push immediate 4 byte value
358       value = addressSpace.get32(p);
359       p += 4;
360       *(++sp) = value;
361       if (log)
362         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
363       break;
364 
365     case DW_OP_const4s:
366       // push immediate 4 byte signed value
367       svalue = (int32_t)addressSpace.get32(p);
368       p += 4;
369       *(++sp) = (pint_t)svalue;
370       if (log)
371         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue);
372       break;
373 
374     case DW_OP_const8u:
375       // push immediate 8 byte value
376       value = (pint_t)addressSpace.get64(p);
377       p += 8;
378       *(++sp) = value;
379       if (log)
380         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
381       break;
382 
383     case DW_OP_const8s:
384       // push immediate 8 byte signed value
385       value = (pint_t)addressSpace.get64(p);
386       p += 8;
387       *(++sp) = value;
388       if (log)
389         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
390       break;
391 
392     case DW_OP_constu:
393       // push immediate ULEB128 value
394       value = (pint_t)addressSpace.getULEB128(p, expressionEnd);
395       *(++sp) = value;
396       if (log)
397         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
398       break;
399 
400     case DW_OP_consts:
401       // push immediate SLEB128 value
402       svalue = (sint_t)addressSpace.getSLEB128(p, expressionEnd);
403       *(++sp) = (pint_t)svalue;
404       if (log)
405         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue);
406       break;
407 
408     case DW_OP_dup:
409       // push top of stack
410       value = *sp;
411       *(++sp) = value;
412       if (log)
413         fprintf(stderr, "duplicate top of stack\n");
414       break;
415 
416     case DW_OP_drop:
417       // pop
418       --sp;
419       if (log)
420         fprintf(stderr, "pop top of stack\n");
421       break;
422 
423     case DW_OP_over:
424       // dup second
425       value = sp[-1];
426       *(++sp) = value;
427       if (log)
428         fprintf(stderr, "duplicate second in stack\n");
429       break;
430 
431     case DW_OP_pick:
432       // pick from
433       reg = addressSpace.get8(p);
434       p += 1;
435       value = sp[-reg];
436       *(++sp) = value;
437       if (log)
438         fprintf(stderr, "duplicate %d in stack\n", reg);
439       break;
440 
441     case DW_OP_swap:
442       // swap top two
443       value = sp[0];
444       sp[0] = sp[-1];
445       sp[-1] = value;
446       if (log)
447         fprintf(stderr, "swap top of stack\n");
448       break;
449 
450     case DW_OP_rot:
451       // rotate top three
452       value = sp[0];
453       sp[0] = sp[-1];
454       sp[-1] = sp[-2];
455       sp[-2] = value;
456       if (log)
457         fprintf(stderr, "rotate top three of stack\n");
458       break;
459 
460     case DW_OP_xderef:
461       // pop stack, dereference, push result
462       value = *sp--;
463       *sp = *((pint_t*)value);
464       if (log)
465         fprintf(stderr, "x-dereference 0x%" PRIx64 "\n", (uint64_t)value);
466       break;
467 
468     case DW_OP_abs:
469       svalue = (sint_t)*sp;
470       if (svalue < 0)
471         *sp = (pint_t)(-svalue);
472       if (log)
473         fprintf(stderr, "abs\n");
474       break;
475 
476     case DW_OP_and:
477       value = *sp--;
478       *sp &= value;
479       if (log)
480         fprintf(stderr, "and\n");
481       break;
482 
483     case DW_OP_div:
484       svalue = (sint_t)(*sp--);
485       svalue2 = (sint_t)*sp;
486       *sp = (pint_t)(svalue2 / svalue);
487       if (log)
488         fprintf(stderr, "div\n");
489       break;
490 
491     case DW_OP_minus:
492       value = *sp--;
493       *sp = *sp - value;
494       if (log)
495         fprintf(stderr, "minus\n");
496       break;
497 
498     case DW_OP_mod:
499       svalue = (sint_t)(*sp--);
500       svalue2 = (sint_t)*sp;
501       *sp = (pint_t)(svalue2 % svalue);
502       if (log)
503         fprintf(stderr, "module\n");
504       break;
505 
506     case DW_OP_mul:
507       svalue = (sint_t)(*sp--);
508       svalue2 = (sint_t)*sp;
509       *sp = (pint_t)(svalue2 * svalue);
510       if (log)
511         fprintf(stderr, "mul\n");
512       break;
513 
514     case DW_OP_neg:
515       *sp = 0 - *sp;
516       if (log)
517         fprintf(stderr, "neg\n");
518       break;
519 
520     case DW_OP_not:
521       svalue = (sint_t)(*sp);
522       *sp = (pint_t)(~svalue);
523       if (log)
524         fprintf(stderr, "not\n");
525       break;
526 
527     case DW_OP_or:
528       value = *sp--;
529       *sp |= value;
530       if (log)
531         fprintf(stderr, "or\n");
532       break;
533 
534     case DW_OP_plus:
535       value = *sp--;
536       *sp += value;
537       if (log)
538         fprintf(stderr, "plus\n");
539       break;
540 
541     case DW_OP_plus_uconst:
542       // pop stack, add uelb128 constant, push result
543       *sp += static_cast<pint_t>(addressSpace.getULEB128(p, expressionEnd));
544       if (log)
545         fprintf(stderr, "add constant\n");
546       break;
547 
548     case DW_OP_shl:
549       value = *sp--;
550       *sp = *sp << value;
551       if (log)
552         fprintf(stderr, "shift left\n");
553       break;
554 
555     case DW_OP_shr:
556       value = *sp--;
557       *sp = *sp >> value;
558       if (log)
559         fprintf(stderr, "shift left\n");
560       break;
561 
562     case DW_OP_shra:
563       value = *sp--;
564       svalue = (sint_t)*sp;
565       *sp = (pint_t)(svalue >> value);
566       if (log)
567         fprintf(stderr, "shift left arithmetric\n");
568       break;
569 
570     case DW_OP_xor:
571       value = *sp--;
572       *sp ^= value;
573       if (log)
574         fprintf(stderr, "xor\n");
575       break;
576 
577     case DW_OP_skip:
578       svalue = (int16_t) addressSpace.get16(p);
579       p += 2;
580       p = (pint_t)((sint_t)p + svalue);
581       if (log)
582         fprintf(stderr, "skip %" PRIu64 "\n", (uint64_t)svalue);
583       break;
584 
585     case DW_OP_bra:
586       svalue = (int16_t) addressSpace.get16(p);
587       p += 2;
588       if (*sp--)
589         p = (pint_t)((sint_t)p + svalue);
590       if (log)
591         fprintf(stderr, "bra %" PRIu64 "\n", (uint64_t)svalue);
592       break;
593 
594     case DW_OP_eq:
595       value = *sp--;
596       *sp = (*sp == value);
597       if (log)
598         fprintf(stderr, "eq\n");
599       break;
600 
601     case DW_OP_ge:
602       value = *sp--;
603       *sp = (*sp >= value);
604       if (log)
605         fprintf(stderr, "ge\n");
606       break;
607 
608     case DW_OP_gt:
609       value = *sp--;
610       *sp = (*sp > value);
611       if (log)
612         fprintf(stderr, "gt\n");
613       break;
614 
615     case DW_OP_le:
616       value = *sp--;
617       *sp = (*sp <= value);
618       if (log)
619         fprintf(stderr, "le\n");
620       break;
621 
622     case DW_OP_lt:
623       value = *sp--;
624       *sp = (*sp < value);
625       if (log)
626         fprintf(stderr, "lt\n");
627       break;
628 
629     case DW_OP_ne:
630       value = *sp--;
631       *sp = (*sp != value);
632       if (log)
633         fprintf(stderr, "ne\n");
634       break;
635 
636     case DW_OP_lit0:
637     case DW_OP_lit1:
638     case DW_OP_lit2:
639     case DW_OP_lit3:
640     case DW_OP_lit4:
641     case DW_OP_lit5:
642     case DW_OP_lit6:
643     case DW_OP_lit7:
644     case DW_OP_lit8:
645     case DW_OP_lit9:
646     case DW_OP_lit10:
647     case DW_OP_lit11:
648     case DW_OP_lit12:
649     case DW_OP_lit13:
650     case DW_OP_lit14:
651     case DW_OP_lit15:
652     case DW_OP_lit16:
653     case DW_OP_lit17:
654     case DW_OP_lit18:
655     case DW_OP_lit19:
656     case DW_OP_lit20:
657     case DW_OP_lit21:
658     case DW_OP_lit22:
659     case DW_OP_lit23:
660     case DW_OP_lit24:
661     case DW_OP_lit25:
662     case DW_OP_lit26:
663     case DW_OP_lit27:
664     case DW_OP_lit28:
665     case DW_OP_lit29:
666     case DW_OP_lit30:
667     case DW_OP_lit31:
668       value = static_cast<pint_t>(opcode - DW_OP_lit0);
669       *(++sp) = value;
670       if (log)
671         fprintf(stderr, "push literal 0x%" PRIx64 "\n", (uint64_t)value);
672       break;
673 
674     case DW_OP_reg0:
675     case DW_OP_reg1:
676     case DW_OP_reg2:
677     case DW_OP_reg3:
678     case DW_OP_reg4:
679     case DW_OP_reg5:
680     case DW_OP_reg6:
681     case DW_OP_reg7:
682     case DW_OP_reg8:
683     case DW_OP_reg9:
684     case DW_OP_reg10:
685     case DW_OP_reg11:
686     case DW_OP_reg12:
687     case DW_OP_reg13:
688     case DW_OP_reg14:
689     case DW_OP_reg15:
690     case DW_OP_reg16:
691     case DW_OP_reg17:
692     case DW_OP_reg18:
693     case DW_OP_reg19:
694     case DW_OP_reg20:
695     case DW_OP_reg21:
696     case DW_OP_reg22:
697     case DW_OP_reg23:
698     case DW_OP_reg24:
699     case DW_OP_reg25:
700     case DW_OP_reg26:
701     case DW_OP_reg27:
702     case DW_OP_reg28:
703     case DW_OP_reg29:
704     case DW_OP_reg30:
705     case DW_OP_reg31:
706       reg = static_cast<uint32_t>(opcode - DW_OP_reg0);
707       *(++sp) = registers.getRegister((int)reg);
708       if (log)
709         fprintf(stderr, "push reg %d\n", reg);
710       break;
711 
712     case DW_OP_regx:
713       reg = static_cast<uint32_t>(addressSpace.getULEB128(p, expressionEnd));
714       *(++sp) = registers.getRegister((int)reg);
715       if (log)
716         fprintf(stderr, "push reg %d + 0x%" PRIx64 "\n", reg, (uint64_t)svalue);
717       break;
718 
719     case DW_OP_breg0:
720     case DW_OP_breg1:
721     case DW_OP_breg2:
722     case DW_OP_breg3:
723     case DW_OP_breg4:
724     case DW_OP_breg5:
725     case DW_OP_breg6:
726     case DW_OP_breg7:
727     case DW_OP_breg8:
728     case DW_OP_breg9:
729     case DW_OP_breg10:
730     case DW_OP_breg11:
731     case DW_OP_breg12:
732     case DW_OP_breg13:
733     case DW_OP_breg14:
734     case DW_OP_breg15:
735     case DW_OP_breg16:
736     case DW_OP_breg17:
737     case DW_OP_breg18:
738     case DW_OP_breg19:
739     case DW_OP_breg20:
740     case DW_OP_breg21:
741     case DW_OP_breg22:
742     case DW_OP_breg23:
743     case DW_OP_breg24:
744     case DW_OP_breg25:
745     case DW_OP_breg26:
746     case DW_OP_breg27:
747     case DW_OP_breg28:
748     case DW_OP_breg29:
749     case DW_OP_breg30:
750     case DW_OP_breg31:
751       reg = static_cast<uint32_t>(opcode - DW_OP_breg0);
752       svalue = (sint_t)addressSpace.getSLEB128(p, expressionEnd);
753       svalue += static_cast<sint_t>(registers.getRegister((int)reg));
754       *(++sp) = (pint_t)(svalue);
755       if (log)
756         fprintf(stderr, "push reg %d + 0x%" PRIx64 "\n", reg, (uint64_t)svalue);
757       break;
758 
759     case DW_OP_bregx:
760       reg = static_cast<uint32_t>(addressSpace.getULEB128(p, expressionEnd));
761       svalue = (sint_t)addressSpace.getSLEB128(p, expressionEnd);
762       svalue += static_cast<sint_t>(registers.getRegister((int)reg));
763       *(++sp) = (pint_t)(svalue);
764       if (log)
765         fprintf(stderr, "push reg %d + 0x%" PRIx64 "\n", reg, (uint64_t)svalue);
766       break;
767 
768     case DW_OP_fbreg:
769       _LIBUNWIND_ABORT("DW_OP_fbreg not implemented");
770       break;
771 
772     case DW_OP_piece:
773       _LIBUNWIND_ABORT("DW_OP_piece not implemented");
774       break;
775 
776     case DW_OP_deref_size:
777       // pop stack, dereference, push result
778       value = *sp--;
779       switch (addressSpace.get8(p++)) {
780       case 1:
781         value = addressSpace.get8(value);
782         break;
783       case 2:
784         value = addressSpace.get16(value);
785         break;
786       case 4:
787         value = addressSpace.get32(value);
788         break;
789       case 8:
790         value = (pint_t)addressSpace.get64(value);
791         break;
792       default:
793         _LIBUNWIND_ABORT("DW_OP_deref_size with bad size");
794       }
795       *(++sp) = value;
796       if (log)
797         fprintf(stderr, "sized dereference 0x%" PRIx64 "\n", (uint64_t)value);
798       break;
799 
800     case DW_OP_xderef_size:
801     case DW_OP_nop:
802     case DW_OP_push_object_addres:
803     case DW_OP_call2:
804     case DW_OP_call4:
805     case DW_OP_call_ref:
806     default:
807       _LIBUNWIND_ABORT("DWARF opcode not implemented");
808     }
809 
810   }
811   if (log)
812     fprintf(stderr, "expression evaluates to 0x%" PRIx64 "\n", (uint64_t)*sp);
813   return *sp;
814 }
815 
816 
817 
818 } // namespace libunwind
819 
820 #endif // __DWARF_INSTRUCTIONS_HPP__
821