aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/libunwind/src/AddressSpace.hpp
blob: 0c4dfeb4e6834b5f14a23ae7aee9ddc13d72d334 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//
// Abstracts accessing local vs remote address spaces.
//
//===----------------------------------------------------------------------===//

#ifndef __ADDRESSSPACE_HPP__
#define __ADDRESSSPACE_HPP__

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "libunwind.h"
#include "config.h"
#include "dwarf2.h"
#include "EHHeaderParser.hpp"
#include "Registers.hpp"

#ifndef _LIBUNWIND_USE_DLADDR
  #if !defined(_LIBUNWIND_IS_BAREMETAL) && !defined(_WIN32)
    #define _LIBUNWIND_USE_DLADDR 1
  #else
    #define _LIBUNWIND_USE_DLADDR 0
  #endif
#endif

#if _LIBUNWIND_USE_DLADDR
#include <dlfcn.h>
#if defined(__ELF__) && defined(_LIBUNWIND_LINK_DL_LIB)
#pragma comment(lib, "dl")
#endif
#endif

#if defined(_LIBUNWIND_ARM_EHABI)
struct EHABIIndexEntry {
  uint32_t functionOffset;
  uint32_t data;
};
#endif

#ifdef __APPLE__

  struct dyld_unwind_sections
  {
    const struct mach_header*   mh;
    const void*                 dwarf_section;
    uintptr_t                   dwarf_section_length;
    const void*                 compact_unwind_section;
    uintptr_t                   compact_unwind_section_length;
  };

  // In 10.7.0 or later, libSystem.dylib implements this function.
  extern "C" bool _dyld_find_unwind_sections(void *, dyld_unwind_sections *);

#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_LIBUNWIND_IS_BAREMETAL)

// When statically linked on bare-metal, the symbols for the EH table are looked
// up without going through the dynamic loader.

// The following linker script may be used to produce the necessary sections and symbols.
// Unless the --eh-frame-hdr linker option is provided, the section is not generated
// and does not take space in the output file.
//
//   .eh_frame :
//   {
//       __eh_frame_start = .;
//       KEEP(*(.eh_frame))
//       __eh_frame_end = .;
//   }
//
//   .eh_frame_hdr :
//   {
//       KEEP(*(.eh_frame_hdr))
//   }
//
//   __eh_frame_hdr_start = SIZEOF(.eh_frame_hdr) > 0 ? ADDR(.eh_frame_hdr) : 0;
//   __eh_frame_hdr_end = SIZEOF(.eh_frame_hdr) > 0 ? . : 0;

extern char __eh_frame_start;
extern char __eh_frame_end;

#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
extern char __eh_frame_hdr_start;
extern char __eh_frame_hdr_end;
#endif

#elif defined(_LIBUNWIND_ARM_EHABI) && defined(_LIBUNWIND_IS_BAREMETAL)

// When statically linked on bare-metal, the symbols for the EH table are looked
// up without going through the dynamic loader.
extern char __exidx_start;
extern char __exidx_end;

#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_WIN32)

#include <windows.h>
#include <psapi.h>

#elif defined(_LIBUNWIND_USE_DL_ITERATE_PHDR) ||                               \
      defined(_LIBUNWIND_USE_DL_UNWIND_FIND_EXIDX)

#include <link.h>

#endif

namespace libunwind {

/// Used by findUnwindSections() to return info about needed sections.
struct UnwindInfoSections {
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) ||                                \
    defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND) ||                              \
    defined(_LIBUNWIND_USE_DL_ITERATE_PHDR)
  // No dso_base for SEH.
  uintptr_t       dso_base;
#endif
#if defined(_LIBUNWIND_USE_DL_ITERATE_PHDR)
  size_t          text_segment_length;
#endif
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
  uintptr_t       dwarf_section;
  size_t          dwarf_section_length;
#endif
#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
  uintptr_t       dwarf_index_section;
  size_t          dwarf_index_section_length;
#endif
#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
  uintptr_t       compact_unwind_section;
  size_t          compact_unwind_section_length;
#endif
#if defined(_LIBUNWIND_ARM_EHABI)
  uintptr_t       arm_section;
  size_t          arm_section_length;
#endif
};


/// LocalAddressSpace is used as a template parameter to UnwindCursor when
/// unwinding a thread in the same process.  The wrappers compile away,
/// making local unwinds fast.
class _LIBUNWIND_HIDDEN LocalAddressSpace {
public:
  typedef uintptr_t pint_t;
  typedef intptr_t  sint_t;
  uint8_t         get8(pint_t addr) {
    uint8_t val;
    memcpy(&val, (void *)addr, sizeof(val));
    return val;
  }
  uint16_t         get16(pint_t addr) {
    uint16_t val;
    memcpy(&val, (void *)addr, sizeof(val));
    return val;
  }
  uint32_t         get32(pint_t addr) {
    uint32_t val;
    memcpy(&val, (void *)addr, sizeof(val));
    return val;
  }
  uint64_t         get64(pint_t addr) {
    uint64_t val;
    memcpy(&val, (void *)addr, sizeof(val));
    return val;
  }
  double           getDouble(pint_t addr) {
    double val;
    memcpy(&val, (void *)addr, sizeof(val));
    return val;
  }
  v128             getVector(pint_t addr) {
    v128 val;
    memcpy(&val, (void *)addr, sizeof(val));
    return val;
  }
  uintptr_t       getP(pint_t addr);
  uint64_t        getRegister(pint_t addr);
  static uint64_t getULEB128(pint_t &addr, pint_t end);
  static int64_t  getSLEB128(pint_t &addr, pint_t end);

  pint_t getEncodedP(pint_t &addr, pint_t end, uint8_t encoding,
                     pint_t datarelBase = 0);
  bool findFunctionName(pint_t addr, char *buf, size_t bufLen,
                        unw_word_t *offset);
  bool findUnwindSections(pint_t targetAddr, UnwindInfoSections &info);
  bool findOtherFDE(pint_t targetAddr, pint_t &fde);

  static LocalAddressSpace sThisAddressSpace;
};

inline uintptr_t LocalAddressSpace::getP(pint_t addr) {
#if __SIZEOF_POINTER__ == 8
  return get64(addr);
#else
  return get32(addr);
#endif
}

inline uint64_t LocalAddressSpace::getRegister(pint_t addr) {
#if __SIZEOF_POINTER__ == 8 || defined(__mips64)
  return get64(addr);
#else
  return get32(addr);
#endif
}

/// Read a ULEB128 into a 64-bit word.
inline uint64_t LocalAddressSpace::getULEB128(pint_t &addr, pint_t end) {
  const uint8_t *p = (uint8_t *)addr;
  const uint8_t *pend = (uint8_t *)end;
  uint64_t result = 0;
  int bit = 0;
  do {
    uint64_t b;

    if (p == pend)
      _LIBUNWIND_ABORT("truncated uleb128 expression");

    b = *p & 0x7f;

    if (bit >= 64 || b << bit >> bit != b) {
      _LIBUNWIND_ABORT("malformed uleb128 expression");
    } else {
      result |= b << bit;
      bit += 7;
    }
  } while (*p++ >= 0x80);
  addr = (pint_t) p;
  return result;
}

/// Read a SLEB128 into a 64-bit word.
inline int64_t LocalAddressSpace::getSLEB128(pint_t &addr, pint_t end) {
  const uint8_t *p = (uint8_t *)addr;
  const uint8_t *pend = (uint8_t *)end;
  int64_t result = 0;
  int bit = 0;
  uint8_t byte;
  do {
    if (p == pend)
      _LIBUNWIND_ABORT("truncated sleb128 expression");
    byte = *p++;
    result |= (uint64_t)(byte & 0x7f) << bit;
    bit += 7;
  } while (byte & 0x80);
  // sign extend negative numbers
  if ((byte & 0x40) != 0 && bit < 64)
    result |= (-1ULL) << bit;
  addr = (pint_t) p;
  return result;
}

inline LocalAddressSpace::pint_t
LocalAddressSpace::getEncodedP(pint_t &addr, pint_t end, uint8_t encoding,
                               pint_t datarelBase) {
  pint_t startAddr = addr;
  const uint8_t *p = (uint8_t *)addr;
  pint_t result;

  // first get value
  switch (encoding & 0x0F) {
  case DW_EH_PE_ptr:
    result = getP(addr);
    p += sizeof(pint_t);
    addr = (pint_t) p;
    break;
  case DW_EH_PE_uleb128:
    result = (pint_t)getULEB128(addr, end);
    break;
  case DW_EH_PE_udata2:
    result = get16(addr);
    p += 2;
    addr = (pint_t) p;
    break;
  case DW_EH_PE_udata4:
    result = get32(addr);
    p += 4;
    addr = (pint_t) p;
    break;
  case DW_EH_PE_udata8:
    result = (pint_t)get64(addr);
    p += 8;
    addr = (pint_t) p;
    break;
  case DW_EH_PE_sleb128:
    result = (pint_t)getSLEB128(addr, end);
    break;
  case DW_EH_PE_sdata2:
    // Sign extend from signed 16-bit value.
    result = (pint_t)(int16_t)get16(addr);
    p += 2;
    addr = (pint_t) p;
    break;
  case DW_EH_PE_sdata4:
    // Sign extend from signed 32-bit value.
    result = (pint_t)(int32_t)get32(addr);
    p += 4;
    addr = (pint_t) p;
    break;
  case DW_EH_PE_sdata8:
    result = (pint_t)get64(addr);
    p += 8;
    addr = (pint_t) p;
    break;
  default:
    _LIBUNWIND_ABORT("unknown pointer encoding");
  }

  // then add relative offset
  switch (encoding & 0x70) {
  case DW_EH_PE_absptr:
    // do nothing
    break;
  case DW_EH_PE_pcrel:
    result += startAddr;
    break;
  case DW_EH_PE_textrel:
    _LIBUNWIND_ABORT("DW_EH_PE_textrel pointer encoding not supported");
    break;
  case DW_EH_PE_datarel:
    // DW_EH_PE_datarel is only valid in a few places, so the parameter has a
    // default value of 0, and we abort in the event that someone calls this
    // function with a datarelBase of 0 and DW_EH_PE_datarel encoding.
    if (datarelBase == 0)
      _LIBUNWIND_ABORT("DW_EH_PE_datarel is invalid with a datarelBase of 0");
    result += datarelBase;
    break;
  case DW_EH_PE_funcrel:
    _LIBUNWIND_ABORT("DW_EH_PE_funcrel pointer encoding not supported");
    break;
  case DW_EH_PE_aligned:
    _LIBUNWIND_ABORT("DW_EH_PE_aligned pointer encoding not supported");
    break;
  default:
    _LIBUNWIND_ABORT("unknown pointer encoding");
    break;
  }

  if (encoding & DW_EH_PE_indirect)
    result = getP(result);

  return result;
}

#if defined(_LIBUNWIND_USE_DL_ITERATE_PHDR)

// The ElfW() macro for pointer-size independent ELF header traversal is not
// provided by <link.h> on some systems (e.g., FreeBSD). On these systems the
// data structures are just called Elf_XXX. Define ElfW() locally.
#if !defined(ElfW)
  #define ElfW(type) Elf_##type
#endif
#if !defined(Elf_Half)
  typedef ElfW(Half) Elf_Half;
#endif
#if !defined(Elf_Phdr)
  typedef ElfW(Phdr) Elf_Phdr;
#endif
#if !defined(Elf_Addr)
  typedef ElfW(Addr) Elf_Addr;
#endif

static Elf_Addr calculateImageBase(struct dl_phdr_info *pinfo) {
  Elf_Addr image_base = pinfo->dlpi_addr;
#if defined(__ANDROID__) && __ANDROID_API__ < 18
  if (image_base == 0) {
    // Normally, an image base of 0 indicates a non-PIE executable. On
    // versions of Android prior to API 18, the dynamic linker reported a
    // dlpi_addr of 0 for PIE executables. Compute the true image base
    // using the PT_PHDR segment.
    // See https://github.com/android/ndk/issues/505.
    for (Elf_Half i = 0; i < pinfo->dlpi_phnum; i++) {
      const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i];
      if (phdr->p_type == PT_PHDR) {
        image_base = reinterpret_cast<Elf_Addr>(pinfo->dlpi_phdr) -
          phdr->p_vaddr;
        break;
      }
    }
  }
#endif
  return image_base;
}

struct _LIBUNWIND_HIDDEN dl_iterate_cb_data {
  LocalAddressSpace *addressSpace;
  UnwindInfoSections *sects;
  uintptr_t targetAddr;
};

#if defined(_LIBUNWIND_USE_FRAME_HEADER_CACHE)
#include "FrameHeaderCache.hpp"

// Typically there is one cache per process, but when libunwind is built as a
// hermetic static library, then each shared object may have its own cache.
static FrameHeaderCache TheFrameHeaderCache;
#endif

static bool checkAddrInSegment(const Elf_Phdr *phdr, size_t image_base,
                               dl_iterate_cb_data *cbdata) {
  if (phdr->p_type == PT_LOAD) {
    uintptr_t begin = image_base + phdr->p_vaddr;
    uintptr_t end = begin + phdr->p_memsz;
    if (cbdata->targetAddr >= begin && cbdata->targetAddr < end) {
      cbdata->sects->dso_base = begin;
      cbdata->sects->text_segment_length = phdr->p_memsz;
      return true;
    }
  }
  return false;
}

static bool checkForUnwindInfoSegment(const Elf_Phdr *phdr, size_t image_base,
                                      dl_iterate_cb_data *cbdata) {
#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
  if (phdr->p_type == PT_GNU_EH_FRAME) {
    EHHeaderParser<LocalAddressSpace>::EHHeaderInfo hdrInfo;
    uintptr_t eh_frame_hdr_start = image_base + phdr->p_vaddr;
    cbdata->sects->dwarf_index_section = eh_frame_hdr_start;
    cbdata->sects->dwarf_index_section_length = phdr->p_memsz;
    if (EHHeaderParser<LocalAddressSpace>::decodeEHHdr(
            *cbdata->addressSpace, eh_frame_hdr_start, phdr->p_memsz,
            hdrInfo)) {
      // .eh_frame_hdr records the start of .eh_frame, but not its size.
      // Rely on a zero terminator to find the end of the section.
      cbdata->sects->dwarf_section = hdrInfo.eh_frame_ptr;
      cbdata->sects->dwarf_section_length = SIZE_MAX;
      return true;
    }
  }
  return false;
#elif defined(_LIBUNWIND_ARM_EHABI)
  if (phdr->p_type == PT_ARM_EXIDX) {
    uintptr_t exidx_start = image_base + phdr->p_vaddr;
    cbdata->sects->arm_section = exidx_start;
    cbdata->sects->arm_section_length = phdr->p_memsz;
    return true;
  }
  return false;
#else
#error Need one of _LIBUNWIND_SUPPORT_DWARF_INDEX or _LIBUNWIND_ARM_EHABI
#endif
}

static int findUnwindSectionsByPhdr(struct dl_phdr_info *pinfo,
                                    size_t pinfo_size, void *data) {
  auto cbdata = static_cast<dl_iterate_cb_data *>(data);
  if (pinfo->dlpi_phnum == 0 || cbdata->targetAddr < pinfo->dlpi_addr)
    return 0;
#if defined(_LIBUNWIND_USE_FRAME_HEADER_CACHE)
  if (TheFrameHeaderCache.find(pinfo, pinfo_size, data))
    return 1;
#else
  // Avoid warning about unused variable.
  (void)pinfo_size;
#endif

  Elf_Addr image_base = calculateImageBase(pinfo);

  // Most shared objects seen in this callback function likely don't contain the
  // target address, so optimize for that. Scan for a matching PT_LOAD segment
  // first and bail when it isn't found.
  bool found_text = false;
  for (Elf_Half i = 0; i < pinfo->dlpi_phnum; ++i) {
    if (checkAddrInSegment(&pinfo->dlpi_phdr[i], image_base, cbdata)) {
      found_text = true;
      break;
    }
  }
  if (!found_text)
    return 0;

  // PT_GNU_EH_FRAME and PT_ARM_EXIDX are usually near the end. Iterate
  // backward.
  bool found_unwind = false;
  for (Elf_Half i = pinfo->dlpi_phnum; i > 0; i--) {
    const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i - 1];
    if (checkForUnwindInfoSegment(phdr, image_base, cbdata)) {
      found_unwind = true;
      break;
    }
  }
  if (!found_unwind)
    return 0;

#if defined(_LIBUNWIND_USE_FRAME_HEADER_CACHE)
  TheFrameHeaderCache.add(cbdata->sects);
#endif
  return 1;
}

#endif  // defined(_LIBUNWIND_USE_DL_ITERATE_PHDR)


inline bool LocalAddressSpace::findUnwindSections(pint_t targetAddr,
                                                  UnwindInfoSections &info) {
#ifdef __APPLE__
  dyld_unwind_sections dyldInfo;
  if (_dyld_find_unwind_sections((void *)targetAddr, &dyldInfo)) {
    info.dso_base                      = (uintptr_t)dyldInfo.mh;
 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
    info.dwarf_section                 = (uintptr_t)dyldInfo.dwarf_section;
    info.dwarf_section_length          = (size_t)dyldInfo.dwarf_section_length;
 #endif
    info.compact_unwind_section        = (uintptr_t)dyldInfo.compact_unwind_section;
    info.compact_unwind_section_length = (size_t)dyldInfo.compact_unwind_section_length;
    return true;
  }
#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_LIBUNWIND_IS_BAREMETAL)
  info.dso_base = 0;
  // Bare metal is statically linked, so no need to ask the dynamic loader
  info.dwarf_section_length = (size_t)(&__eh_frame_end - &__eh_frame_start);
  info.dwarf_section =        (uintptr_t)(&__eh_frame_start);
  _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: section %p length %p",
                             (void *)info.dwarf_section, (void *)info.dwarf_section_length);
#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
  info.dwarf_index_section =        (uintptr_t)(&__eh_frame_hdr_start);
  info.dwarf_index_section_length = (size_t)(&__eh_frame_hdr_end - &__eh_frame_hdr_start);
  _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: index section %p length %p",
                             (void *)info.dwarf_index_section, (void *)info.dwarf_index_section_length);
#endif
  if (info.dwarf_section_length)
    return true;
#elif defined(_LIBUNWIND_ARM_EHABI) && defined(_LIBUNWIND_IS_BAREMETAL)
  // Bare metal is statically linked, so no need to ask the dynamic loader
  info.arm_section =        (uintptr_t)(&__exidx_start);
  info.arm_section_length = (size_t)(&__exidx_end - &__exidx_start);
  _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: section %p length %p",
                             (void *)info.arm_section, (void *)info.arm_section_length);
  if (info.arm_section && info.arm_section_length)
    return true;
#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) && defined(_WIN32)
  HMODULE mods[1024];
  HANDLE process = GetCurrentProcess();
  DWORD needed;

  if (!EnumProcessModules(process, mods, sizeof(mods), &needed)) {
    DWORD err = GetLastError();
    _LIBUNWIND_TRACE_UNWINDING("findUnwindSections: EnumProcessModules failed, "
                               "returned error %d", (int)err);
    return false;
  }

  for (unsigned i = 0; i < (needed / sizeof(HMODULE)); i++) {
    PIMAGE_DOS_HEADER pidh = (PIMAGE_DOS_HEADER)mods[i];
    PIMAGE_NT_HEADERS pinh = (PIMAGE_NT_HEADERS)((BYTE *)pidh + pidh->e_lfanew);
    PIMAGE_FILE_HEADER pifh = (PIMAGE_FILE_HEADER)&pinh->FileHeader;
    PIMAGE_SECTION_HEADER pish = IMAGE_FIRST_SECTION(pinh);
    bool found_obj = false;
    bool found_hdr = false;

    info.dso_base = (uintptr_t)mods[i];
    for (unsigned j = 0; j < pifh->NumberOfSections; j++, pish++) {
      uintptr_t begin = pish->VirtualAddress + (uintptr_t)mods[i];
      uintptr_t end = begin + pish->Misc.VirtualSize;
      if (!strncmp((const char *)pish->Name, ".text",
                   IMAGE_SIZEOF_SHORT_NAME)) {
        if (targetAddr >= begin && targetAddr < end)
          found_obj = true;
      } else if (!strncmp((const char *)pish->Name, ".eh_frame",
                          IMAGE_SIZEOF_SHORT_NAME)) {
        info.dwarf_section = begin;
        info.dwarf_section_length = pish->Misc.VirtualSize;
        found_hdr = true;
      }
      if (found_obj && found_hdr)
        return true;
    }
  }
  return false;
#elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)
  // Don't even bother, since Windows has functions that do all this stuff
  // for us.
  (void)targetAddr;
  (void)info;
  return true;
#elif defined(_LIBUNWIND_USE_DL_UNWIND_FIND_EXIDX)
  int length = 0;
  info.arm_section =
      (uintptr_t)dl_unwind_find_exidx((_Unwind_Ptr)targetAddr, &length);
  info.arm_section_length = (size_t)length * sizeof(EHABIIndexEntry);
  if (info.arm_section && info.arm_section_length)
    return true;
#elif defined(_LIBUNWIND_USE_DL_ITERATE_PHDR)
  dl_iterate_cb_data cb_data = {this, &info, targetAddr};
  int found = dl_iterate_phdr(findUnwindSectionsByPhdr, &cb_data);
  return static_cast<bool>(found);
#endif

  return false;
}


inline bool LocalAddressSpace::findOtherFDE(pint_t targetAddr, pint_t &fde) {
  // TO DO: if OS has way to dynamically register FDEs, check that.
  (void)targetAddr;
  (void)fde;
  return false;
}

inline bool LocalAddressSpace::findFunctionName(pint_t addr, char *buf,
                                                size_t bufLen,
                                                unw_word_t *offset) {
#if _LIBUNWIND_USE_DLADDR
  Dl_info dyldInfo;
  if (dladdr((void *)addr, &dyldInfo)) {
    if (dyldInfo.dli_sname != NULL) {
      snprintf(buf, bufLen, "%s", dyldInfo.dli_sname);
      *offset = (addr - (pint_t) dyldInfo.dli_saddr);
      return true;
    }
  }
#else
  (void)addr;
  (void)buf;
  (void)bufLen;
  (void)offset;
#endif
  return false;
}

} // namespace libunwind

#endif // __ADDRESSSPACE_HPP__