• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 //===-------------------------- DwarfInstructions.hpp ---------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //
8 //  Processor specific interpretation of DWARF unwind info.
9 //
10 //===----------------------------------------------------------------------===//
11 
12 #ifndef __DWARF_INSTRUCTIONS_HPP__
13 #define __DWARF_INSTRUCTIONS_HPP__
14 
15 #include <stdint.h>
16 #include <stdio.h>
17 #include <stdlib.h>
18 
19 #include "dwarf2.h"
20 #include "Registers.hpp"
21 #include "DwarfParser.hpp"
22 #include "config.h"
23 
24 
25 namespace libunwind {
26 
27 
28 /// DwarfInstructions maps abtract DWARF unwind instructions to a particular
29 /// architecture
30 template <typename A, typename R>
31 class DwarfInstructions {
32 public:
33   typedef typename A::pint_t pint_t;
34   typedef typename A::sint_t sint_t;
35 
36   static int stepWithDwarf(A &addressSpace, pint_t pc, pint_t fdeStart,
37                            R &registers, bool &isSignalFrame);
38 
39 private:
40 
41   enum {
42     DW_X86_64_RET_ADDR = 16
43   };
44 
45   enum {
46     DW_X86_RET_ADDR = 8
47   };
48 
49   typedef typename CFI_Parser<A>::RegisterLocation  RegisterLocation;
50   typedef typename CFI_Parser<A>::PrologInfo        PrologInfo;
51   typedef typename CFI_Parser<A>::FDE_Info          FDE_Info;
52   typedef typename CFI_Parser<A>::CIE_Info          CIE_Info;
53 
54   static pint_t evaluateExpression(pint_t expression, A &addressSpace,
55                                    const R &registers,
56                                    pint_t initialStackValue);
57   static pint_t getSavedRegister(A &addressSpace, const R &registers,
58                                  pint_t cfa, const RegisterLocation &savedReg);
59   static double getSavedFloatRegister(A &addressSpace, const R &registers,
60                                   pint_t cfa, const RegisterLocation &savedReg);
61   static v128 getSavedVectorRegister(A &addressSpace, const R &registers,
62                                   pint_t cfa, const RegisterLocation &savedReg);
63 
getCFA(A & addressSpace,const PrologInfo & prolog,const R & registers)64   static pint_t getCFA(A &addressSpace, const PrologInfo &prolog,
65                        const R &registers) {
66     if (prolog.cfaRegister != 0)
67       return (pint_t)((sint_t)registers.getRegister((int)prolog.cfaRegister) +
68              prolog.cfaRegisterOffset);
69     if (prolog.cfaExpression != 0)
70       return evaluateExpression((pint_t)prolog.cfaExpression, addressSpace,
71                                 registers, 0);
72     assert(0 && "getCFA(): unknown location");
73     __builtin_unreachable();
74   }
75 };
76 
77 
78 template <typename A, typename R>
getSavedRegister(A & addressSpace,const R & registers,pint_t cfa,const RegisterLocation & savedReg)79 typename A::pint_t DwarfInstructions<A, R>::getSavedRegister(
80     A &addressSpace, const R &registers, pint_t cfa,
81     const RegisterLocation &savedReg) {
82   switch (savedReg.location) {
83   case CFI_Parser<A>::kRegisterInCFA:
84     return (pint_t)addressSpace.getRegister(cfa + (pint_t)savedReg.value);
85 
86   case CFI_Parser<A>::kRegisterAtExpression:
87     return (pint_t)addressSpace.getRegister(evaluateExpression(
88         (pint_t)savedReg.value, addressSpace, registers, cfa));
89 
90   case CFI_Parser<A>::kRegisterIsExpression:
91     return evaluateExpression((pint_t)savedReg.value, addressSpace,
92                               registers, cfa);
93 
94   case CFI_Parser<A>::kRegisterInRegister:
95     return registers.getRegister((int)savedReg.value);
96   case CFI_Parser<A>::kRegisterUndefined:
97     return 0;
98   case CFI_Parser<A>::kRegisterUnused:
99   case CFI_Parser<A>::kRegisterOffsetFromCFA:
100     // FIX ME
101     break;
102   }
103   _LIBUNWIND_ABORT("unsupported restore location for register");
104 }
105 
106 template <typename A, typename R>
getSavedFloatRegister(A & addressSpace,const R & registers,pint_t cfa,const RegisterLocation & savedReg)107 double DwarfInstructions<A, R>::getSavedFloatRegister(
108     A &addressSpace, const R &registers, pint_t cfa,
109     const RegisterLocation &savedReg) {
110   switch (savedReg.location) {
111   case CFI_Parser<A>::kRegisterInCFA:
112     return addressSpace.getDouble(cfa + (pint_t)savedReg.value);
113 
114   case CFI_Parser<A>::kRegisterAtExpression:
115     return addressSpace.getDouble(
116         evaluateExpression((pint_t)savedReg.value, addressSpace,
117                             registers, cfa));
118 
119   case CFI_Parser<A>::kRegisterIsExpression:
120   case CFI_Parser<A>::kRegisterUnused:
121   case CFI_Parser<A>::kRegisterUndefined:
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>::kRegisterUndefined:
146   case CFI_Parser<A>::kRegisterOffsetFromCFA:
147   case CFI_Parser<A>::kRegisterInRegister:
148     // FIX ME
149     break;
150   }
151   _LIBUNWIND_ABORT("unsupported restore location for vector register");
152 }
153 
154 template <typename A, typename R>
stepWithDwarf(A & addressSpace,pint_t pc,pint_t fdeStart,R & registers,bool & isSignalFrame)155 int DwarfInstructions<A, R>::stepWithDwarf(A &addressSpace, pint_t pc,
156                                            pint_t fdeStart, R &registers,
157                                            bool &isSignalFrame) {
158   FDE_Info fdeInfo;
159   CIE_Info cieInfo;
160   if (CFI_Parser<A>::decodeFDE(addressSpace, fdeStart, &fdeInfo,
161                                &cieInfo) == NULL) {
162     PrologInfo prolog;
163     if (CFI_Parser<A>::parseFDEInstructions(addressSpace, fdeInfo, cieInfo, pc,
164                                             R::getArch(), &prolog)) {
165       // get pointer to cfa (architecture specific)
166       pint_t cfa = getCFA(addressSpace, prolog, registers);
167 
168        // restore registers that DWARF says were saved
169       R newRegisters = registers;
170       pint_t returnAddress = 0;
171       const int lastReg = R::lastDwarfRegNum();
172       assert(static_cast<int>(CFI_Parser<A>::kMaxRegisterNumber) >= lastReg &&
173              "register range too large");
174       assert(lastReg >= (int)cieInfo.returnAddressRegister &&
175              "register range does not contain return address register");
176       for (int i = 0; i <= lastReg; ++i) {
177         if (prolog.savedRegisters[i].location !=
178             CFI_Parser<A>::kRegisterUnused) {
179           if (registers.validFloatRegister(i))
180             newRegisters.setFloatRegister(
181                 i, getSavedFloatRegister(addressSpace, registers, cfa,
182                                          prolog.savedRegisters[i]));
183           else if (registers.validVectorRegister(i))
184             newRegisters.setVectorRegister(
185                 i, getSavedVectorRegister(addressSpace, registers, cfa,
186                                           prolog.savedRegisters[i]));
187           else if (i == (int)cieInfo.returnAddressRegister)
188             returnAddress = getSavedRegister(addressSpace, registers, cfa,
189                                              prolog.savedRegisters[i]);
190           else if (registers.validRegister(i))
191             newRegisters.setRegister(
192                 i, getSavedRegister(addressSpace, registers, cfa,
193                                     prolog.savedRegisters[i]));
194           else
195             return UNW_EBADREG;
196         } else if (i == (int)cieInfo.returnAddressRegister) {
197             // Leaf function keeps the return address in register and there is no
198             // explicit intructions how to restore it.
199             returnAddress = registers.getRegister(cieInfo.returnAddressRegister);
200         }
201       }
202 
203       // By definition, the CFA is the stack pointer at the call site, so
204       // restoring SP means setting it to CFA.
205       newRegisters.setSP(cfa);
206 
207       isSignalFrame = cieInfo.isSignalFrame;
208 
209 #if defined(_LIBUNWIND_TARGET_AARCH64)
210       // If the target is aarch64 then the return address may have been signed
211       // using the v8.3 pointer authentication extensions. The original
212       // return address needs to be authenticated before the return address is
213       // restored. autia1716 is used instead of autia as autia1716 assembles
214       // to a NOP on pre-v8.3a architectures.
215       if ((R::getArch() == REGISTERS_ARM64) &&
216           prolog.savedRegisters[UNW_ARM64_RA_SIGN_STATE].value) {
217 #if !defined(_LIBUNWIND_IS_NATIVE_ONLY)
218         return UNW_ECROSSRASIGNING;
219 #else
220         register unsigned long long x17 __asm("x17") = returnAddress;
221         register unsigned long long x16 __asm("x16") = cfa;
222 
223         // These are the autia1716/autib1716 instructions. The hint instructions
224         // are used here as gcc does not assemble autia1716/autib1716 for pre
225         // armv8.3a targets.
226         if (cieInfo.addressesSignedWithBKey)
227           asm("hint 0xe" : "+r"(x17) : "r"(x16)); // autib1716
228         else
229           asm("hint 0xc" : "+r"(x17) : "r"(x16)); // autia1716
230         returnAddress = x17;
231 #endif
232       }
233 #endif
234 
235 #if defined(_LIBUNWIND_TARGET_SPARC)
236       if (R::getArch() == REGISTERS_SPARC) {
237         // Skip call site instruction and delay slot
238         returnAddress += 8;
239         // Skip unimp instruction if function returns a struct
240         if ((addressSpace.get32(returnAddress) & 0xC1C00000) == 0)
241           returnAddress += 4;
242       }
243 #endif
244 
245 #if defined(_LIBUNWIND_TARGET_PPC64)
246 #define PPC64_ELFV1_R2_LOAD_INST_ENCODING 0xe8410028u // ld r2,40(r1)
247 #define PPC64_ELFV1_R2_OFFSET 40
248 #define PPC64_ELFV2_R2_LOAD_INST_ENCODING 0xe8410018u // ld r2,24(r1)
249 #define PPC64_ELFV2_R2_OFFSET 24
250       // If the instruction at return address is a TOC (r2) restore,
251       // then r2 was saved and needs to be restored.
252       // ELFv2 ABI specifies that the TOC Pointer must be saved at SP + 24,
253       // while in ELFv1 ABI it is saved at SP + 40.
254       if (R::getArch() == REGISTERS_PPC64 && returnAddress != 0) {
255         pint_t sp = newRegisters.getRegister(UNW_REG_SP);
256         pint_t r2 = 0;
257         switch (addressSpace.get32(returnAddress)) {
258         case PPC64_ELFV1_R2_LOAD_INST_ENCODING:
259           r2 = addressSpace.get64(sp + PPC64_ELFV1_R2_OFFSET);
260           break;
261         case PPC64_ELFV2_R2_LOAD_INST_ENCODING:
262           r2 = addressSpace.get64(sp + PPC64_ELFV2_R2_OFFSET);
263           break;
264         }
265         if (r2)
266           newRegisters.setRegister(UNW_PPC64_R2, r2);
267       }
268 #endif
269 
270       // Return address is address after call site instruction, so setting IP to
271       // that does simualates a return.
272       newRegisters.setIP(returnAddress);
273 
274       // Simulate the step by replacing the register set with the new ones.
275       registers = newRegisters;
276 
277       return UNW_STEP_SUCCESS;
278     }
279   }
280   return UNW_EBADFRAME;
281 }
282 
283 template <typename A, typename R>
284 typename A::pint_t
evaluateExpression(pint_t expression,A & addressSpace,const R & registers,pint_t initialStackValue)285 DwarfInstructions<A, R>::evaluateExpression(pint_t expression, A &addressSpace,
286                                             const R &registers,
287                                             pint_t initialStackValue) {
288   const bool log = false;
289   pint_t p = expression;
290   pint_t expressionEnd = expression + 20; // temp, until len read
291   pint_t length = (pint_t)addressSpace.getULEB128(p, expressionEnd);
292   expressionEnd = p + length;
293   if (log)
294     fprintf(stderr, "evaluateExpression(): length=%" PRIu64 "\n",
295             (uint64_t)length);
296   pint_t stack[100];
297   pint_t *sp = stack;
298   *(++sp) = initialStackValue;
299 
300   while (p < expressionEnd) {
301     if (log) {
302       for (pint_t *t = sp; t > stack; --t) {
303         fprintf(stderr, "sp[] = 0x%" PRIx64 "\n", (uint64_t)(*t));
304       }
305     }
306     uint8_t opcode = addressSpace.get8(p++);
307     sint_t svalue, svalue2;
308     pint_t value;
309     uint32_t reg;
310     switch (opcode) {
311     case DW_OP_addr:
312       // push immediate address sized value
313       value = addressSpace.getP(p);
314       p += sizeof(pint_t);
315       *(++sp) = value;
316       if (log)
317         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
318       break;
319 
320     case DW_OP_deref:
321       // pop stack, dereference, push result
322       value = *sp--;
323       *(++sp) = addressSpace.getP(value);
324       if (log)
325         fprintf(stderr, "dereference 0x%" PRIx64 "\n", (uint64_t)value);
326       break;
327 
328     case DW_OP_const1u:
329       // push immediate 1 byte value
330       value = addressSpace.get8(p);
331       p += 1;
332       *(++sp) = value;
333       if (log)
334         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
335       break;
336 
337     case DW_OP_const1s:
338       // push immediate 1 byte signed value
339       svalue = (int8_t) addressSpace.get8(p);
340       p += 1;
341       *(++sp) = (pint_t)svalue;
342       if (log)
343         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue);
344       break;
345 
346     case DW_OP_const2u:
347       // push immediate 2 byte value
348       value = addressSpace.get16(p);
349       p += 2;
350       *(++sp) = value;
351       if (log)
352         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
353       break;
354 
355     case DW_OP_const2s:
356       // push immediate 2 byte signed value
357       svalue = (int16_t) addressSpace.get16(p);
358       p += 2;
359       *(++sp) = (pint_t)svalue;
360       if (log)
361         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue);
362       break;
363 
364     case DW_OP_const4u:
365       // push immediate 4 byte value
366       value = addressSpace.get32(p);
367       p += 4;
368       *(++sp) = value;
369       if (log)
370         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
371       break;
372 
373     case DW_OP_const4s:
374       // push immediate 4 byte signed value
375       svalue = (int32_t)addressSpace.get32(p);
376       p += 4;
377       *(++sp) = (pint_t)svalue;
378       if (log)
379         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue);
380       break;
381 
382     case DW_OP_const8u:
383       // push immediate 8 byte value
384       value = (pint_t)addressSpace.get64(p);
385       p += 8;
386       *(++sp) = value;
387       if (log)
388         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
389       break;
390 
391     case DW_OP_const8s:
392       // push immediate 8 byte signed value
393       value = (pint_t)addressSpace.get64(p);
394       p += 8;
395       *(++sp) = value;
396       if (log)
397         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
398       break;
399 
400     case DW_OP_constu:
401       // push immediate ULEB128 value
402       value = (pint_t)addressSpace.getULEB128(p, expressionEnd);
403       *(++sp) = value;
404       if (log)
405         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)value);
406       break;
407 
408     case DW_OP_consts:
409       // push immediate SLEB128 value
410       svalue = (sint_t)addressSpace.getSLEB128(p, expressionEnd);
411       *(++sp) = (pint_t)svalue;
412       if (log)
413         fprintf(stderr, "push 0x%" PRIx64 "\n", (uint64_t)svalue);
414       break;
415 
416     case DW_OP_dup:
417       // push top of stack
418       value = *sp;
419       *(++sp) = value;
420       if (log)
421         fprintf(stderr, "duplicate top of stack\n");
422       break;
423 
424     case DW_OP_drop:
425       // pop
426       --sp;
427       if (log)
428         fprintf(stderr, "pop top of stack\n");
429       break;
430 
431     case DW_OP_over:
432       // dup second
433       value = sp[-1];
434       *(++sp) = value;
435       if (log)
436         fprintf(stderr, "duplicate second in stack\n");
437       break;
438 
439     case DW_OP_pick:
440       // pick from
441       reg = addressSpace.get8(p);
442       p += 1;
443       value = sp[-(int)reg];
444       *(++sp) = value;
445       if (log)
446         fprintf(stderr, "duplicate %d in stack\n", reg);
447       break;
448 
449     case DW_OP_swap:
450       // swap top two
451       value = sp[0];
452       sp[0] = sp[-1];
453       sp[-1] = value;
454       if (log)
455         fprintf(stderr, "swap top of stack\n");
456       break;
457 
458     case DW_OP_rot:
459       // rotate top three
460       value = sp[0];
461       sp[0] = sp[-1];
462       sp[-1] = sp[-2];
463       sp[-2] = value;
464       if (log)
465         fprintf(stderr, "rotate top three of stack\n");
466       break;
467 
468     case DW_OP_xderef:
469       // pop stack, dereference, push result
470       value = *sp--;
471       *sp = *((pint_t*)value);
472       if (log)
473         fprintf(stderr, "x-dereference 0x%" PRIx64 "\n", (uint64_t)value);
474       break;
475 
476     case DW_OP_abs:
477       svalue = (sint_t)*sp;
478       if (svalue < 0)
479         *sp = (pint_t)(-svalue);
480       if (log)
481         fprintf(stderr, "abs\n");
482       break;
483 
484     case DW_OP_and:
485       value = *sp--;
486       *sp &= value;
487       if (log)
488         fprintf(stderr, "and\n");
489       break;
490 
491     case DW_OP_div:
492       svalue = (sint_t)(*sp--);
493       svalue2 = (sint_t)*sp;
494       *sp = (pint_t)(svalue2 / svalue);
495       if (log)
496         fprintf(stderr, "div\n");
497       break;
498 
499     case DW_OP_minus:
500       value = *sp--;
501       *sp = *sp - value;
502       if (log)
503         fprintf(stderr, "minus\n");
504       break;
505 
506     case DW_OP_mod:
507       svalue = (sint_t)(*sp--);
508       svalue2 = (sint_t)*sp;
509       *sp = (pint_t)(svalue2 % svalue);
510       if (log)
511         fprintf(stderr, "module\n");
512       break;
513 
514     case DW_OP_mul:
515       svalue = (sint_t)(*sp--);
516       svalue2 = (sint_t)*sp;
517       *sp = (pint_t)(svalue2 * svalue);
518       if (log)
519         fprintf(stderr, "mul\n");
520       break;
521 
522     case DW_OP_neg:
523       *sp = 0 - *sp;
524       if (log)
525         fprintf(stderr, "neg\n");
526       break;
527 
528     case DW_OP_not:
529       svalue = (sint_t)(*sp);
530       *sp = (pint_t)(~svalue);
531       if (log)
532         fprintf(stderr, "not\n");
533       break;
534 
535     case DW_OP_or:
536       value = *sp--;
537       *sp |= value;
538       if (log)
539         fprintf(stderr, "or\n");
540       break;
541 
542     case DW_OP_plus:
543       value = *sp--;
544       *sp += value;
545       if (log)
546         fprintf(stderr, "plus\n");
547       break;
548 
549     case DW_OP_plus_uconst:
550       // pop stack, add uelb128 constant, push result
551       *sp += static_cast<pint_t>(addressSpace.getULEB128(p, expressionEnd));
552       if (log)
553         fprintf(stderr, "add constant\n");
554       break;
555 
556     case DW_OP_shl:
557       value = *sp--;
558       *sp = *sp << value;
559       if (log)
560         fprintf(stderr, "shift left\n");
561       break;
562 
563     case DW_OP_shr:
564       value = *sp--;
565       *sp = *sp >> value;
566       if (log)
567         fprintf(stderr, "shift left\n");
568       break;
569 
570     case DW_OP_shra:
571       value = *sp--;
572       svalue = (sint_t)*sp;
573       *sp = (pint_t)(svalue >> value);
574       if (log)
575         fprintf(stderr, "shift left arithmetric\n");
576       break;
577 
578     case DW_OP_xor:
579       value = *sp--;
580       *sp ^= value;
581       if (log)
582         fprintf(stderr, "xor\n");
583       break;
584 
585     case DW_OP_skip:
586       svalue = (int16_t) addressSpace.get16(p);
587       p += 2;
588       p = (pint_t)((sint_t)p + svalue);
589       if (log)
590         fprintf(stderr, "skip %" PRIu64 "\n", (uint64_t)svalue);
591       break;
592 
593     case DW_OP_bra:
594       svalue = (int16_t) addressSpace.get16(p);
595       p += 2;
596       if (*sp--)
597         p = (pint_t)((sint_t)p + svalue);
598       if (log)
599         fprintf(stderr, "bra %" PRIu64 "\n", (uint64_t)svalue);
600       break;
601 
602     case DW_OP_eq:
603       value = *sp--;
604       *sp = (*sp == value);
605       if (log)
606         fprintf(stderr, "eq\n");
607       break;
608 
609     case DW_OP_ge:
610       value = *sp--;
611       *sp = (*sp >= value);
612       if (log)
613         fprintf(stderr, "ge\n");
614       break;
615 
616     case DW_OP_gt:
617       value = *sp--;
618       *sp = (*sp > value);
619       if (log)
620         fprintf(stderr, "gt\n");
621       break;
622 
623     case DW_OP_le:
624       value = *sp--;
625       *sp = (*sp <= value);
626       if (log)
627         fprintf(stderr, "le\n");
628       break;
629 
630     case DW_OP_lt:
631       value = *sp--;
632       *sp = (*sp < value);
633       if (log)
634         fprintf(stderr, "lt\n");
635       break;
636 
637     case DW_OP_ne:
638       value = *sp--;
639       *sp = (*sp != value);
640       if (log)
641         fprintf(stderr, "ne\n");
642       break;
643 
644     case DW_OP_lit0:
645     case DW_OP_lit1:
646     case DW_OP_lit2:
647     case DW_OP_lit3:
648     case DW_OP_lit4:
649     case DW_OP_lit5:
650     case DW_OP_lit6:
651     case DW_OP_lit7:
652     case DW_OP_lit8:
653     case DW_OP_lit9:
654     case DW_OP_lit10:
655     case DW_OP_lit11:
656     case DW_OP_lit12:
657     case DW_OP_lit13:
658     case DW_OP_lit14:
659     case DW_OP_lit15:
660     case DW_OP_lit16:
661     case DW_OP_lit17:
662     case DW_OP_lit18:
663     case DW_OP_lit19:
664     case DW_OP_lit20:
665     case DW_OP_lit21:
666     case DW_OP_lit22:
667     case DW_OP_lit23:
668     case DW_OP_lit24:
669     case DW_OP_lit25:
670     case DW_OP_lit26:
671     case DW_OP_lit27:
672     case DW_OP_lit28:
673     case DW_OP_lit29:
674     case DW_OP_lit30:
675     case DW_OP_lit31:
676       value = static_cast<pint_t>(opcode - DW_OP_lit0);
677       *(++sp) = value;
678       if (log)
679         fprintf(stderr, "push literal 0x%" PRIx64 "\n", (uint64_t)value);
680       break;
681 
682     case DW_OP_reg0:
683     case DW_OP_reg1:
684     case DW_OP_reg2:
685     case DW_OP_reg3:
686     case DW_OP_reg4:
687     case DW_OP_reg5:
688     case DW_OP_reg6:
689     case DW_OP_reg7:
690     case DW_OP_reg8:
691     case DW_OP_reg9:
692     case DW_OP_reg10:
693     case DW_OP_reg11:
694     case DW_OP_reg12:
695     case DW_OP_reg13:
696     case DW_OP_reg14:
697     case DW_OP_reg15:
698     case DW_OP_reg16:
699     case DW_OP_reg17:
700     case DW_OP_reg18:
701     case DW_OP_reg19:
702     case DW_OP_reg20:
703     case DW_OP_reg21:
704     case DW_OP_reg22:
705     case DW_OP_reg23:
706     case DW_OP_reg24:
707     case DW_OP_reg25:
708     case DW_OP_reg26:
709     case DW_OP_reg27:
710     case DW_OP_reg28:
711     case DW_OP_reg29:
712     case DW_OP_reg30:
713     case DW_OP_reg31:
714       reg = static_cast<uint32_t>(opcode - DW_OP_reg0);
715       *(++sp) = registers.getRegister((int)reg);
716       if (log)
717         fprintf(stderr, "push reg %d\n", reg);
718       break;
719 
720     case DW_OP_regx:
721       reg = static_cast<uint32_t>(addressSpace.getULEB128(p, expressionEnd));
722       *(++sp) = registers.getRegister((int)reg);
723       if (log)
724         fprintf(stderr, "push reg %d + 0x%" PRIx64 "\n", reg, (uint64_t)svalue);
725       break;
726 
727     case DW_OP_breg0:
728     case DW_OP_breg1:
729     case DW_OP_breg2:
730     case DW_OP_breg3:
731     case DW_OP_breg4:
732     case DW_OP_breg5:
733     case DW_OP_breg6:
734     case DW_OP_breg7:
735     case DW_OP_breg8:
736     case DW_OP_breg9:
737     case DW_OP_breg10:
738     case DW_OP_breg11:
739     case DW_OP_breg12:
740     case DW_OP_breg13:
741     case DW_OP_breg14:
742     case DW_OP_breg15:
743     case DW_OP_breg16:
744     case DW_OP_breg17:
745     case DW_OP_breg18:
746     case DW_OP_breg19:
747     case DW_OP_breg20:
748     case DW_OP_breg21:
749     case DW_OP_breg22:
750     case DW_OP_breg23:
751     case DW_OP_breg24:
752     case DW_OP_breg25:
753     case DW_OP_breg26:
754     case DW_OP_breg27:
755     case DW_OP_breg28:
756     case DW_OP_breg29:
757     case DW_OP_breg30:
758     case DW_OP_breg31:
759       reg = static_cast<uint32_t>(opcode - DW_OP_breg0);
760       svalue = (sint_t)addressSpace.getSLEB128(p, expressionEnd);
761       svalue += static_cast<sint_t>(registers.getRegister((int)reg));
762       *(++sp) = (pint_t)(svalue);
763       if (log)
764         fprintf(stderr, "push reg %d + 0x%" PRIx64 "\n", reg, (uint64_t)svalue);
765       break;
766 
767     case DW_OP_bregx:
768       reg = static_cast<uint32_t>(addressSpace.getULEB128(p, expressionEnd));
769       svalue = (sint_t)addressSpace.getSLEB128(p, expressionEnd);
770       svalue += static_cast<sint_t>(registers.getRegister((int)reg));
771       *(++sp) = (pint_t)(svalue);
772       if (log)
773         fprintf(stderr, "push reg %d + 0x%" PRIx64 "\n", reg, (uint64_t)svalue);
774       break;
775 
776     case DW_OP_fbreg:
777       _LIBUNWIND_ABORT("DW_OP_fbreg not implemented");
778       break;
779 
780     case DW_OP_piece:
781       _LIBUNWIND_ABORT("DW_OP_piece not implemented");
782       break;
783 
784     case DW_OP_deref_size:
785       // pop stack, dereference, push result
786       value = *sp--;
787       switch (addressSpace.get8(p++)) {
788       case 1:
789         value = addressSpace.get8(value);
790         break;
791       case 2:
792         value = addressSpace.get16(value);
793         break;
794       case 4:
795         value = addressSpace.get32(value);
796         break;
797       case 8:
798         value = (pint_t)addressSpace.get64(value);
799         break;
800       default:
801         _LIBUNWIND_ABORT("DW_OP_deref_size with bad size");
802       }
803       *(++sp) = value;
804       if (log)
805         fprintf(stderr, "sized dereference 0x%" PRIx64 "\n", (uint64_t)value);
806       break;
807 
808     case DW_OP_xderef_size:
809     case DW_OP_nop:
810     case DW_OP_push_object_addres:
811     case DW_OP_call2:
812     case DW_OP_call4:
813     case DW_OP_call_ref:
814     default:
815       _LIBUNWIND_ABORT("DWARF opcode not implemented");
816     }
817 
818   }
819   if (log)
820     fprintf(stderr, "expression evaluates to 0x%" PRIx64 "\n", (uint64_t)*sp);
821   return *sp;
822 }
823 
824 
825 
826 } // namespace libunwind
827 
828 #endif // __DWARF_INSTRUCTIONS_HPP__
829