1//===-- DWARFContext.cpp --------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "llvm/DebugInfo/DWARF/DWARFContext.h"
11#include "llvm/ADT/SmallString.h"
12#include "llvm/ADT/StringSwitch.h"
13#include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
14#include "llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h"
15#include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
16#include "llvm/Object/MachO.h"
17#include "llvm/Object/RelocVisitor.h"
18#include "llvm/Support/Compression.h"
19#include "llvm/Support/Dwarf.h"
20#include "llvm/Support/ELF.h"
21#include "llvm/Support/Format.h"
22#include "llvm/Support/Path.h"
23#include "llvm/Support/raw_ostream.h"
24#include <algorithm>
25using namespace llvm;
26using namespace dwarf;
27using namespace object;
28
29#define DEBUG_TYPE "dwarf"
30
31typedef DWARFDebugLine::LineTable DWARFLineTable;
32typedef DILineInfoSpecifier::FileLineInfoKind FileLineInfoKind;
33typedef DILineInfoSpecifier::FunctionNameKind FunctionNameKind;
34
35static void dumpPubSection(raw_ostream &OS, StringRef Name, StringRef Data,
36                           bool LittleEndian, bool GnuStyle) {
37  OS << "\n." << Name << " contents:\n";
38  DataExtractor pubNames(Data, LittleEndian, 0);
39  uint32_t offset = 0;
40  while (pubNames.isValidOffset(offset)) {
41    OS << "length = " << format("0x%08x", pubNames.getU32(&offset));
42    OS << " version = " << format("0x%04x", pubNames.getU16(&offset));
43    OS << " unit_offset = " << format("0x%08x", pubNames.getU32(&offset));
44    OS << " unit_size = " << format("0x%08x", pubNames.getU32(&offset)) << '\n';
45    if (GnuStyle)
46      OS << "Offset     Linkage  Kind     Name\n";
47    else
48      OS << "Offset     Name\n";
49
50    while (offset < Data.size()) {
51      uint32_t dieRef = pubNames.getU32(&offset);
52      if (dieRef == 0)
53        break;
54      OS << format("0x%8.8x ", dieRef);
55      if (GnuStyle) {
56        PubIndexEntryDescriptor desc(pubNames.getU8(&offset));
57        OS << format("%-8s", dwarf::GDBIndexEntryLinkageString(desc.Linkage))
58           << ' ' << format("%-8s", dwarf::GDBIndexEntryKindString(desc.Kind))
59           << ' ';
60      }
61      OS << '\"' << pubNames.getCStr(&offset) << "\"\n";
62    }
63  }
64}
65
66static void dumpAccelSection(raw_ostream &OS, StringRef Name,
67                             const DWARFSection& Section, StringRef StringSection,
68                             bool LittleEndian) {
69  DataExtractor AccelSection(Section.Data, LittleEndian, 0);
70  DataExtractor StrData(StringSection, LittleEndian, 0);
71  OS << "\n." << Name << " contents:\n";
72  DWARFAcceleratorTable Accel(AccelSection, StrData, Section.Relocs);
73  if (!Accel.extract())
74    return;
75  Accel.dump(OS);
76}
77
78void DWARFContext::dump(raw_ostream &OS, DIDumpType DumpType, bool DumpEH) {
79  if (DumpType == DIDT_All || DumpType == DIDT_Abbrev) {
80    OS << ".debug_abbrev contents:\n";
81    getDebugAbbrev()->dump(OS);
82  }
83
84  if (DumpType == DIDT_All || DumpType == DIDT_AbbrevDwo)
85    if (const DWARFDebugAbbrev *D = getDebugAbbrevDWO()) {
86      OS << "\n.debug_abbrev.dwo contents:\n";
87      D->dump(OS);
88    }
89
90  if (DumpType == DIDT_All || DumpType == DIDT_Info) {
91    OS << "\n.debug_info contents:\n";
92    for (const auto &CU : compile_units())
93      CU->dump(OS);
94  }
95
96  if ((DumpType == DIDT_All || DumpType == DIDT_InfoDwo) &&
97      getNumDWOCompileUnits()) {
98    OS << "\n.debug_info.dwo contents:\n";
99    for (const auto &DWOCU : dwo_compile_units())
100      DWOCU->dump(OS);
101  }
102
103  if ((DumpType == DIDT_All || DumpType == DIDT_Types) && getNumTypeUnits()) {
104    OS << "\n.debug_types contents:\n";
105    for (const auto &TUS : type_unit_sections())
106      for (const auto &TU : TUS)
107        TU->dump(OS);
108  }
109
110  if ((DumpType == DIDT_All || DumpType == DIDT_TypesDwo) &&
111      getNumDWOTypeUnits()) {
112    OS << "\n.debug_types.dwo contents:\n";
113    for (const auto &DWOTUS : dwo_type_unit_sections())
114      for (const auto &DWOTU : DWOTUS)
115        DWOTU->dump(OS);
116  }
117
118  if (DumpType == DIDT_All || DumpType == DIDT_Loc) {
119    OS << "\n.debug_loc contents:\n";
120    getDebugLoc()->dump(OS);
121  }
122
123  if (DumpType == DIDT_All || DumpType == DIDT_LocDwo) {
124    OS << "\n.debug_loc.dwo contents:\n";
125    getDebugLocDWO()->dump(OS);
126  }
127
128  if (DumpType == DIDT_All || DumpType == DIDT_Frames) {
129    OS << "\n.debug_frame contents:\n";
130    getDebugFrame()->dump(OS);
131    if (DumpEH) {
132      OS << "\n.eh_frame contents:\n";
133      getEHFrame()->dump(OS);
134    }
135  }
136
137  if (DumpType == DIDT_All || DumpType == DIDT_Macro) {
138    OS << "\n.debug_macinfo contents:\n";
139    getDebugMacro()->dump(OS);
140  }
141
142  uint32_t offset = 0;
143  if (DumpType == DIDT_All || DumpType == DIDT_Aranges) {
144    OS << "\n.debug_aranges contents:\n";
145    DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0);
146    DWARFDebugArangeSet set;
147    while (set.extract(arangesData, &offset))
148      set.dump(OS);
149  }
150
151  uint8_t savedAddressByteSize = 0;
152  if (DumpType == DIDT_All || DumpType == DIDT_Line) {
153    OS << "\n.debug_line contents:\n";
154    for (const auto &CU : compile_units()) {
155      savedAddressByteSize = CU->getAddressByteSize();
156      const auto *CUDIE = CU->getUnitDIE();
157      if (CUDIE == nullptr)
158        continue;
159      unsigned stmtOffset = CUDIE->getAttributeValueAsSectionOffset(
160          CU.get(), DW_AT_stmt_list, -1U);
161      if (stmtOffset != -1U) {
162        DataExtractor lineData(getLineSection().Data, isLittleEndian(),
163                               savedAddressByteSize);
164        DWARFDebugLine::LineTable LineTable;
165        LineTable.parse(lineData, &getLineSection().Relocs, &stmtOffset);
166        LineTable.dump(OS);
167      }
168    }
169  }
170
171  if (DumpType == DIDT_All || DumpType == DIDT_CUIndex) {
172    OS << "\n.debug_cu_index contents:\n";
173    getCUIndex().dump(OS);
174  }
175
176  if (DumpType == DIDT_All || DumpType == DIDT_TUIndex) {
177    OS << "\n.debug_tu_index contents:\n";
178    getTUIndex().dump(OS);
179  }
180
181  if (DumpType == DIDT_All || DumpType == DIDT_LineDwo) {
182    OS << "\n.debug_line.dwo contents:\n";
183    unsigned stmtOffset = 0;
184    DataExtractor lineData(getLineDWOSection().Data, isLittleEndian(),
185                           savedAddressByteSize);
186    DWARFDebugLine::LineTable LineTable;
187    while (LineTable.Prologue.parse(lineData, &stmtOffset)) {
188      LineTable.dump(OS);
189      LineTable.clear();
190    }
191  }
192
193  if (DumpType == DIDT_All || DumpType == DIDT_Str) {
194    OS << "\n.debug_str contents:\n";
195    DataExtractor strData(getStringSection(), isLittleEndian(), 0);
196    offset = 0;
197    uint32_t strOffset = 0;
198    while (const char *s = strData.getCStr(&offset)) {
199      OS << format("0x%8.8x: \"%s\"\n", strOffset, s);
200      strOffset = offset;
201    }
202  }
203
204  if ((DumpType == DIDT_All || DumpType == DIDT_StrDwo) &&
205      !getStringDWOSection().empty()) {
206    OS << "\n.debug_str.dwo contents:\n";
207    DataExtractor strDWOData(getStringDWOSection(), isLittleEndian(), 0);
208    offset = 0;
209    uint32_t strDWOOffset = 0;
210    while (const char *s = strDWOData.getCStr(&offset)) {
211      OS << format("0x%8.8x: \"%s\"\n", strDWOOffset, s);
212      strDWOOffset = offset;
213    }
214  }
215
216  if (DumpType == DIDT_All || DumpType == DIDT_Ranges) {
217    OS << "\n.debug_ranges contents:\n";
218    // In fact, different compile units may have different address byte
219    // sizes, but for simplicity we just use the address byte size of the last
220    // compile unit (there is no easy and fast way to associate address range
221    // list and the compile unit it describes).
222    DataExtractor rangesData(getRangeSection(), isLittleEndian(),
223                             savedAddressByteSize);
224    offset = 0;
225    DWARFDebugRangeList rangeList;
226    while (rangeList.extract(rangesData, &offset))
227      rangeList.dump(OS);
228  }
229
230  if (DumpType == DIDT_All || DumpType == DIDT_Pubnames)
231    dumpPubSection(OS, "debug_pubnames", getPubNamesSection(),
232                   isLittleEndian(), false);
233
234  if (DumpType == DIDT_All || DumpType == DIDT_Pubtypes)
235    dumpPubSection(OS, "debug_pubtypes", getPubTypesSection(),
236                   isLittleEndian(), false);
237
238  if (DumpType == DIDT_All || DumpType == DIDT_GnuPubnames)
239    dumpPubSection(OS, "debug_gnu_pubnames", getGnuPubNamesSection(),
240                   isLittleEndian(), true /* GnuStyle */);
241
242  if (DumpType == DIDT_All || DumpType == DIDT_GnuPubtypes)
243    dumpPubSection(OS, "debug_gnu_pubtypes", getGnuPubTypesSection(),
244                   isLittleEndian(), true /* GnuStyle */);
245
246  if ((DumpType == DIDT_All || DumpType == DIDT_StrOffsetsDwo) &&
247      !getStringOffsetDWOSection().empty()) {
248    OS << "\n.debug_str_offsets.dwo contents:\n";
249    DataExtractor strOffsetExt(getStringOffsetDWOSection(), isLittleEndian(),
250                               0);
251    offset = 0;
252    uint64_t size = getStringOffsetDWOSection().size();
253    while (offset < size) {
254      OS << format("0x%8.8x: ", offset);
255      OS << format("%8.8x\n", strOffsetExt.getU32(&offset));
256    }
257  }
258
259  if (DumpType == DIDT_All || DumpType == DIDT_AppleNames)
260    dumpAccelSection(OS, "apple_names", getAppleNamesSection(),
261                     getStringSection(), isLittleEndian());
262
263  if (DumpType == DIDT_All || DumpType == DIDT_AppleTypes)
264    dumpAccelSection(OS, "apple_types", getAppleTypesSection(),
265                     getStringSection(), isLittleEndian());
266
267  if (DumpType == DIDT_All || DumpType == DIDT_AppleNamespaces)
268    dumpAccelSection(OS, "apple_namespaces", getAppleNamespacesSection(),
269                     getStringSection(), isLittleEndian());
270
271  if (DumpType == DIDT_All || DumpType == DIDT_AppleObjC)
272    dumpAccelSection(OS, "apple_objc", getAppleObjCSection(),
273                     getStringSection(), isLittleEndian());
274}
275
276const DWARFUnitIndex &DWARFContext::getCUIndex() {
277  if (CUIndex)
278    return *CUIndex;
279
280  DataExtractor CUIndexData(getCUIndexSection(), isLittleEndian(), 0);
281
282  CUIndex = llvm::make_unique<DWARFUnitIndex>(DW_SECT_INFO);
283  CUIndex->parse(CUIndexData);
284  return *CUIndex;
285}
286
287const DWARFUnitIndex &DWARFContext::getTUIndex() {
288  if (TUIndex)
289    return *TUIndex;
290
291  DataExtractor TUIndexData(getTUIndexSection(), isLittleEndian(), 0);
292
293  TUIndex = llvm::make_unique<DWARFUnitIndex>(DW_SECT_TYPES);
294  TUIndex->parse(TUIndexData);
295  return *TUIndex;
296}
297
298const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
299  if (Abbrev)
300    return Abbrev.get();
301
302  DataExtractor abbrData(getAbbrevSection(), isLittleEndian(), 0);
303
304  Abbrev.reset(new DWARFDebugAbbrev());
305  Abbrev->extract(abbrData);
306  return Abbrev.get();
307}
308
309const DWARFDebugAbbrev *DWARFContext::getDebugAbbrevDWO() {
310  if (AbbrevDWO)
311    return AbbrevDWO.get();
312
313  DataExtractor abbrData(getAbbrevDWOSection(), isLittleEndian(), 0);
314  AbbrevDWO.reset(new DWARFDebugAbbrev());
315  AbbrevDWO->extract(abbrData);
316  return AbbrevDWO.get();
317}
318
319const DWARFDebugLoc *DWARFContext::getDebugLoc() {
320  if (Loc)
321    return Loc.get();
322
323  DataExtractor LocData(getLocSection().Data, isLittleEndian(), 0);
324  Loc.reset(new DWARFDebugLoc(getLocSection().Relocs));
325  // assume all compile units have the same address byte size
326  if (getNumCompileUnits())
327    Loc->parse(LocData, getCompileUnitAtIndex(0)->getAddressByteSize());
328  return Loc.get();
329}
330
331const DWARFDebugLocDWO *DWARFContext::getDebugLocDWO() {
332  if (LocDWO)
333    return LocDWO.get();
334
335  DataExtractor LocData(getLocDWOSection().Data, isLittleEndian(), 0);
336  LocDWO.reset(new DWARFDebugLocDWO());
337  LocDWO->parse(LocData);
338  return LocDWO.get();
339}
340
341const DWARFDebugAranges *DWARFContext::getDebugAranges() {
342  if (Aranges)
343    return Aranges.get();
344
345  Aranges.reset(new DWARFDebugAranges());
346  Aranges->generate(this);
347  return Aranges.get();
348}
349
350const DWARFDebugFrame *DWARFContext::getDebugFrame() {
351  if (DebugFrame)
352    return DebugFrame.get();
353
354  // There's a "bug" in the DWARFv3 standard with respect to the target address
355  // size within debug frame sections. While DWARF is supposed to be independent
356  // of its container, FDEs have fields with size being "target address size",
357  // which isn't specified in DWARF in general. It's only specified for CUs, but
358  // .eh_frame can appear without a .debug_info section. Follow the example of
359  // other tools (libdwarf) and extract this from the container (ObjectFile
360  // provides this information). This problem is fixed in DWARFv4
361  // See this dwarf-discuss discussion for more details:
362  // http://lists.dwarfstd.org/htdig.cgi/dwarf-discuss-dwarfstd.org/2011-December/001173.html
363  DataExtractor debugFrameData(getDebugFrameSection(), isLittleEndian(),
364                               getAddressSize());
365  DebugFrame.reset(new DWARFDebugFrame(false /* IsEH */));
366  DebugFrame->parse(debugFrameData);
367  return DebugFrame.get();
368}
369
370const DWARFDebugFrame *DWARFContext::getEHFrame() {
371  if (EHFrame)
372    return EHFrame.get();
373
374  DataExtractor debugFrameData(getEHFrameSection(), isLittleEndian(),
375                               getAddressSize());
376  DebugFrame.reset(new DWARFDebugFrame(true /* IsEH */));
377  DebugFrame->parse(debugFrameData);
378  return DebugFrame.get();
379}
380
381const DWARFDebugMacro *DWARFContext::getDebugMacro() {
382  if (Macro)
383    return Macro.get();
384
385  DataExtractor MacinfoData(getMacinfoSection(), isLittleEndian(), 0);
386  Macro.reset(new DWARFDebugMacro());
387  Macro->parse(MacinfoData);
388  return Macro.get();
389}
390
391const DWARFLineTable *
392DWARFContext::getLineTableForUnit(DWARFUnit *U) {
393  if (!Line)
394    Line.reset(new DWARFDebugLine(&getLineSection().Relocs));
395
396  const auto *UnitDIE = U->getUnitDIE();
397  if (UnitDIE == nullptr)
398    return nullptr;
399
400  unsigned stmtOffset =
401      UnitDIE->getAttributeValueAsSectionOffset(U, DW_AT_stmt_list, -1U);
402  if (stmtOffset == -1U)
403    return nullptr; // No line table for this compile unit.
404
405  stmtOffset += U->getLineTableOffset();
406  // See if the line table is cached.
407  if (const DWARFLineTable *lt = Line->getLineTable(stmtOffset))
408    return lt;
409
410  // We have to parse it first.
411  DataExtractor lineData(U->getLineSection(), isLittleEndian(),
412                         U->getAddressByteSize());
413  return Line->getOrParseLineTable(lineData, stmtOffset);
414}
415
416void DWARFContext::parseCompileUnits() {
417  CUs.parse(*this, getInfoSection());
418}
419
420void DWARFContext::parseTypeUnits() {
421  if (!TUs.empty())
422    return;
423  for (const auto &I : getTypesSections()) {
424    TUs.emplace_back();
425    TUs.back().parse(*this, I.second);
426  }
427}
428
429void DWARFContext::parseDWOCompileUnits() {
430  DWOCUs.parseDWO(*this, getInfoDWOSection());
431}
432
433void DWARFContext::parseDWOTypeUnits() {
434  if (!DWOTUs.empty())
435    return;
436  for (const auto &I : getTypesDWOSections()) {
437    DWOTUs.emplace_back();
438    DWOTUs.back().parseDWO(*this, I.second);
439  }
440}
441
442DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint32_t Offset) {
443  parseCompileUnits();
444  return CUs.getUnitForOffset(Offset);
445}
446
447DWARFCompileUnit *DWARFContext::getCompileUnitForAddress(uint64_t Address) {
448  // First, get the offset of the compile unit.
449  uint32_t CUOffset = getDebugAranges()->findAddress(Address);
450  // Retrieve the compile unit.
451  return getCompileUnitForOffset(CUOffset);
452}
453
454static bool getFunctionNameForAddress(DWARFCompileUnit *CU, uint64_t Address,
455                                      FunctionNameKind Kind,
456                                      std::string &FunctionName) {
457  if (Kind == FunctionNameKind::None)
458    return false;
459  // The address may correspond to instruction in some inlined function,
460  // so we have to build the chain of inlined functions and take the
461  // name of the topmost function in it.
462  const DWARFDebugInfoEntryInlinedChain &InlinedChain =
463      CU->getInlinedChainForAddress(Address);
464  if (InlinedChain.DIEs.size() == 0)
465    return false;
466  const DWARFDebugInfoEntryMinimal &TopFunctionDIE = InlinedChain.DIEs[0];
467  if (const char *Name =
468          TopFunctionDIE.getSubroutineName(InlinedChain.U, Kind)) {
469    FunctionName = Name;
470    return true;
471  }
472  return false;
473}
474
475DILineInfo DWARFContext::getLineInfoForAddress(uint64_t Address,
476                                               DILineInfoSpecifier Spec) {
477  DILineInfo Result;
478
479  DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
480  if (!CU)
481    return Result;
482  getFunctionNameForAddress(CU, Address, Spec.FNKind, Result.FunctionName);
483  if (Spec.FLIKind != FileLineInfoKind::None) {
484    if (const DWARFLineTable *LineTable = getLineTableForUnit(CU))
485      LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
486                                           Spec.FLIKind, Result);
487  }
488  return Result;
489}
490
491DILineInfoTable
492DWARFContext::getLineInfoForAddressRange(uint64_t Address, uint64_t Size,
493                                         DILineInfoSpecifier Spec) {
494  DILineInfoTable  Lines;
495  DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
496  if (!CU)
497    return Lines;
498
499  std::string FunctionName = "<invalid>";
500  getFunctionNameForAddress(CU, Address, Spec.FNKind, FunctionName);
501
502  // If the Specifier says we don't need FileLineInfo, just
503  // return the top-most function at the starting address.
504  if (Spec.FLIKind == FileLineInfoKind::None) {
505    DILineInfo Result;
506    Result.FunctionName = FunctionName;
507    Lines.push_back(std::make_pair(Address, Result));
508    return Lines;
509  }
510
511  const DWARFLineTable *LineTable = getLineTableForUnit(CU);
512
513  // Get the index of row we're looking for in the line table.
514  std::vector<uint32_t> RowVector;
515  if (!LineTable->lookupAddressRange(Address, Size, RowVector))
516    return Lines;
517
518  for (uint32_t RowIndex : RowVector) {
519    // Take file number and line/column from the row.
520    const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
521    DILineInfo Result;
522    LineTable->getFileNameByIndex(Row.File, CU->getCompilationDir(),
523                                  Spec.FLIKind, Result.FileName);
524    Result.FunctionName = FunctionName;
525    Result.Line = Row.Line;
526    Result.Column = Row.Column;
527    Lines.push_back(std::make_pair(Row.Address, Result));
528  }
529
530  return Lines;
531}
532
533DIInliningInfo
534DWARFContext::getInliningInfoForAddress(uint64_t Address,
535                                        DILineInfoSpecifier Spec) {
536  DIInliningInfo InliningInfo;
537
538  DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
539  if (!CU)
540    return InliningInfo;
541
542  const DWARFLineTable *LineTable = nullptr;
543  const DWARFDebugInfoEntryInlinedChain &InlinedChain =
544      CU->getInlinedChainForAddress(Address);
545  if (InlinedChain.DIEs.size() == 0) {
546    // If there is no DIE for address (e.g. it is in unavailable .dwo file),
547    // try to at least get file/line info from symbol table.
548    if (Spec.FLIKind != FileLineInfoKind::None) {
549      DILineInfo Frame;
550      LineTable = getLineTableForUnit(CU);
551      if (LineTable &&
552          LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
553                                               Spec.FLIKind, Frame))
554        InliningInfo.addFrame(Frame);
555    }
556    return InliningInfo;
557  }
558
559  uint32_t CallFile = 0, CallLine = 0, CallColumn = 0;
560  for (uint32_t i = 0, n = InlinedChain.DIEs.size(); i != n; i++) {
561    const DWARFDebugInfoEntryMinimal &FunctionDIE = InlinedChain.DIEs[i];
562    DILineInfo Frame;
563    // Get function name if necessary.
564    if (const char *Name =
565            FunctionDIE.getSubroutineName(InlinedChain.U, Spec.FNKind))
566      Frame.FunctionName = Name;
567    if (Spec.FLIKind != FileLineInfoKind::None) {
568      if (i == 0) {
569        // For the topmost frame, initialize the line table of this
570        // compile unit and fetch file/line info from it.
571        LineTable = getLineTableForUnit(CU);
572        // For the topmost routine, get file/line info from line table.
573        if (LineTable)
574          LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
575                                               Spec.FLIKind, Frame);
576      } else {
577        // Otherwise, use call file, call line and call column from
578        // previous DIE in inlined chain.
579        if (LineTable)
580          LineTable->getFileNameByIndex(CallFile, CU->getCompilationDir(),
581                                        Spec.FLIKind, Frame.FileName);
582        Frame.Line = CallLine;
583        Frame.Column = CallColumn;
584      }
585      // Get call file/line/column of a current DIE.
586      if (i + 1 < n) {
587        FunctionDIE.getCallerFrame(InlinedChain.U, CallFile, CallLine,
588                                   CallColumn);
589      }
590    }
591    InliningInfo.addFrame(Frame);
592  }
593  return InliningInfo;
594}
595
596static bool consumeCompressedGnuHeader(StringRef &data,
597                                       uint64_t &OriginalSize) {
598  // Consume "ZLIB" prefix.
599  if (!data.startswith("ZLIB"))
600    return false;
601  data = data.substr(4);
602  // Consume uncompressed section size (big-endian 8 bytes).
603  DataExtractor extractor(data, false, 8);
604  uint32_t Offset = 0;
605  OriginalSize = extractor.getU64(&Offset);
606  if (Offset == 0)
607    return false;
608  data = data.substr(Offset);
609  return true;
610}
611
612static bool consumeCompressedZLibHeader(StringRef &Data, uint64_t &OriginalSize,
613                                        bool IsLE, bool Is64Bit) {
614  using namespace ELF;
615  uint64_t HdrSize = Is64Bit ? sizeof(Elf64_Chdr) : sizeof(Elf32_Chdr);
616  if (Data.size() < HdrSize)
617    return false;
618
619  DataExtractor Extractor(Data, IsLE, 0);
620  uint32_t Offset = 0;
621  if (Extractor.getUnsigned(&Offset, Is64Bit ? sizeof(Elf64_Word)
622                                             : sizeof(Elf32_Word)) !=
623      ELFCOMPRESS_ZLIB)
624    return false;
625
626  // Skip Elf64_Chdr::ch_reserved field.
627  if (Is64Bit)
628    Offset += sizeof(Elf64_Word);
629
630  OriginalSize = Extractor.getUnsigned(&Offset, Is64Bit ? sizeof(Elf64_Xword)
631                                                        : sizeof(Elf32_Word));
632  Data = Data.substr(HdrSize);
633  return true;
634}
635
636static bool tryDecompress(StringRef &Name, StringRef &Data,
637                          SmallString<32> &Out, bool ZLibStyle, bool IsLE,
638                          bool Is64Bit) {
639  if (!zlib::isAvailable())
640    return false;
641
642  uint64_t OriginalSize;
643  bool Result =
644      ZLibStyle ? consumeCompressedZLibHeader(Data, OriginalSize, IsLE, Is64Bit)
645                : consumeCompressedGnuHeader(Data, OriginalSize);
646
647  if (!Result || zlib::uncompress(Data, Out, OriginalSize) != zlib::StatusOK)
648    return false;
649
650  // gnu-style names are started from "z", consume that.
651  if (!ZLibStyle)
652    Name = Name.substr(1);
653  return true;
654}
655
656DWARFContextInMemory::DWARFContextInMemory(const object::ObjectFile &Obj,
657    const LoadedObjectInfo *L)
658    : IsLittleEndian(Obj.isLittleEndian()),
659      AddressSize(Obj.getBytesInAddress()) {
660  for (const SectionRef &Section : Obj.sections()) {
661    StringRef name;
662    Section.getName(name);
663    // Skip BSS and Virtual sections, they aren't interesting.
664    bool IsBSS = Section.isBSS();
665    if (IsBSS)
666      continue;
667    bool IsVirtual = Section.isVirtual();
668    if (IsVirtual)
669      continue;
670    StringRef data;
671
672    section_iterator RelocatedSection = Section.getRelocatedSection();
673    // Try to obtain an already relocated version of this section.
674    // Else use the unrelocated section from the object file. We'll have to
675    // apply relocations ourselves later.
676    if (!L || !L->getLoadedSectionContents(*RelocatedSection,data))
677      Section.getContents(data);
678
679    name = name.substr(name.find_first_not_of("._")); // Skip . and _ prefixes.
680
681    bool ZLibStyleCompressed = Section.isCompressed();
682    if (ZLibStyleCompressed || name.startswith("zdebug_")) {
683      SmallString<32> Out;
684      if (!tryDecompress(name, data, Out, ZLibStyleCompressed, IsLittleEndian,
685                         AddressSize == 8))
686        continue;
687      UncompressedSections.emplace_back(std::move(Out));
688      data = UncompressedSections.back();
689    }
690
691    StringRef *SectionData =
692        StringSwitch<StringRef *>(name)
693            .Case("debug_info", &InfoSection.Data)
694            .Case("debug_abbrev", &AbbrevSection)
695            .Case("debug_loc", &LocSection.Data)
696            .Case("debug_line", &LineSection.Data)
697            .Case("debug_aranges", &ARangeSection)
698            .Case("debug_frame", &DebugFrameSection)
699            .Case("eh_frame", &EHFrameSection)
700            .Case("debug_str", &StringSection)
701            .Case("debug_ranges", &RangeSection)
702            .Case("debug_macinfo", &MacinfoSection)
703            .Case("debug_pubnames", &PubNamesSection)
704            .Case("debug_pubtypes", &PubTypesSection)
705            .Case("debug_gnu_pubnames", &GnuPubNamesSection)
706            .Case("debug_gnu_pubtypes", &GnuPubTypesSection)
707            .Case("debug_info.dwo", &InfoDWOSection.Data)
708            .Case("debug_abbrev.dwo", &AbbrevDWOSection)
709            .Case("debug_loc.dwo", &LocDWOSection.Data)
710            .Case("debug_line.dwo", &LineDWOSection.Data)
711            .Case("debug_str.dwo", &StringDWOSection)
712            .Case("debug_str_offsets.dwo", &StringOffsetDWOSection)
713            .Case("debug_addr", &AddrSection)
714            .Case("apple_names", &AppleNamesSection.Data)
715            .Case("apple_types", &AppleTypesSection.Data)
716            .Case("apple_namespaces", &AppleNamespacesSection.Data)
717            .Case("apple_namespac", &AppleNamespacesSection.Data)
718            .Case("apple_objc", &AppleObjCSection.Data)
719            .Case("debug_cu_index", &CUIndexSection)
720            .Case("debug_tu_index", &TUIndexSection)
721            // Any more debug info sections go here.
722            .Default(nullptr);
723    if (SectionData) {
724      *SectionData = data;
725      if (name == "debug_ranges") {
726        // FIXME: Use the other dwo range section when we emit it.
727        RangeDWOSection = data;
728      }
729    } else if (name == "debug_types") {
730      // Find debug_types data by section rather than name as there are
731      // multiple, comdat grouped, debug_types sections.
732      TypesSections[Section].Data = data;
733    } else if (name == "debug_types.dwo") {
734      TypesDWOSections[Section].Data = data;
735    }
736
737    if (RelocatedSection == Obj.section_end())
738      continue;
739
740    StringRef RelSecName;
741    StringRef RelSecData;
742    RelocatedSection->getName(RelSecName);
743
744    // If the section we're relocating was relocated already by the JIT,
745    // then we used the relocated version above, so we do not need to process
746    // relocations for it now.
747    if (L && L->getLoadedSectionContents(*RelocatedSection,RelSecData))
748      continue;
749
750    // In Mach-o files, the relocations do not need to be applied if
751    // there is no load offset to apply. The value read at the
752    // relocation point already factors in the section address
753    // (actually applying the relocations will produce wrong results
754    // as the section address will be added twice).
755    if (!L && isa<MachOObjectFile>(&Obj))
756      continue;
757
758    RelSecName = RelSecName.substr(
759        RelSecName.find_first_not_of("._")); // Skip . and _ prefixes.
760
761    // TODO: Add support for relocations in other sections as needed.
762    // Record relocations for the debug_info and debug_line sections.
763    RelocAddrMap *Map = StringSwitch<RelocAddrMap*>(RelSecName)
764        .Case("debug_info", &InfoSection.Relocs)
765        .Case("debug_loc", &LocSection.Relocs)
766        .Case("debug_info.dwo", &InfoDWOSection.Relocs)
767        .Case("debug_line", &LineSection.Relocs)
768        .Case("apple_names", &AppleNamesSection.Relocs)
769        .Case("apple_types", &AppleTypesSection.Relocs)
770        .Case("apple_namespaces", &AppleNamespacesSection.Relocs)
771        .Case("apple_namespac", &AppleNamespacesSection.Relocs)
772        .Case("apple_objc", &AppleObjCSection.Relocs)
773        .Default(nullptr);
774    if (!Map) {
775      // Find debug_types relocs by section rather than name as there are
776      // multiple, comdat grouped, debug_types sections.
777      if (RelSecName == "debug_types")
778        Map = &TypesSections[*RelocatedSection].Relocs;
779      else if (RelSecName == "debug_types.dwo")
780        Map = &TypesDWOSections[*RelocatedSection].Relocs;
781      else
782        continue;
783    }
784
785    if (Section.relocation_begin() != Section.relocation_end()) {
786      uint64_t SectionSize = RelocatedSection->getSize();
787      for (const RelocationRef &Reloc : Section.relocations()) {
788        uint64_t Address = Reloc.getOffset();
789        uint64_t Type = Reloc.getType();
790        uint64_t SymAddr = 0;
791        uint64_t SectionLoadAddress = 0;
792        object::symbol_iterator Sym = Reloc.getSymbol();
793        object::section_iterator RSec = Obj.section_end();
794
795        // First calculate the address of the symbol or section as it appears
796        // in the objct file
797        if (Sym != Obj.symbol_end()) {
798          Expected<uint64_t> SymAddrOrErr = Sym->getAddress();
799          if (!SymAddrOrErr) {
800            std::string Buf;
801            raw_string_ostream OS(Buf);
802            logAllUnhandledErrors(SymAddrOrErr.takeError(), OS, "");
803            OS.flush();
804            errs() << "error: failed to compute symbol address: "
805                   << Buf << '\n';
806            continue;
807          }
808          SymAddr = *SymAddrOrErr;
809          // Also remember what section this symbol is in for later
810          auto SectOrErr = Sym->getSection();
811          if (!SectOrErr) {
812            std::string Buf;
813            raw_string_ostream OS(Buf);
814            logAllUnhandledErrors(SectOrErr.takeError(), OS, "");
815            OS.flush();
816            errs() << "error: failed to get symbol section: "
817                   << Buf << '\n';
818            continue;
819          }
820          RSec = *SectOrErr;
821        } else if (auto *MObj = dyn_cast<MachOObjectFile>(&Obj)) {
822          // MachO also has relocations that point to sections and
823          // scattered relocations.
824          auto RelocInfo = MObj->getRelocation(Reloc.getRawDataRefImpl());
825          if (MObj->isRelocationScattered(RelocInfo)) {
826            // FIXME: it's not clear how to correctly handle scattered
827            // relocations.
828            continue;
829          } else {
830            RSec = MObj->getRelocationSection(Reloc.getRawDataRefImpl());
831            SymAddr = RSec->getAddress();
832          }
833        }
834
835        // If we are given load addresses for the sections, we need to adjust:
836        // SymAddr = (Address of Symbol Or Section in File) -
837        //           (Address of Section in File) +
838        //           (Load Address of Section)
839        if (L != nullptr && RSec != Obj.section_end()) {
840          // RSec is now either the section being targeted or the section
841          // containing the symbol being targeted. In either case,
842          // we need to perform the same computation.
843          StringRef SecName;
844          RSec->getName(SecName);
845//           llvm::dbgs() << "Name: '" << SecName
846//                        << "', RSec: " << RSec->getRawDataRefImpl()
847//                        << ", Section: " << Section.getRawDataRefImpl() << "\n";
848          SectionLoadAddress = L->getSectionLoadAddress(*RSec);
849          if (SectionLoadAddress != 0)
850            SymAddr += SectionLoadAddress - RSec->getAddress();
851        }
852
853        object::RelocVisitor V(Obj);
854        object::RelocToApply R(V.visit(Type, Reloc, SymAddr));
855        if (V.error()) {
856          SmallString<32> Name;
857          Reloc.getTypeName(Name);
858          errs() << "error: failed to compute relocation: "
859                 << Name << "\n";
860          continue;
861        }
862
863        if (Address + R.Width > SectionSize) {
864          errs() << "error: " << R.Width << "-byte relocation starting "
865                 << Address << " bytes into section " << name << " which is "
866                 << SectionSize << " bytes long.\n";
867          continue;
868        }
869        if (R.Width > 8) {
870          errs() << "error: can't handle a relocation of more than 8 bytes at "
871                    "a time.\n";
872          continue;
873        }
874        DEBUG(dbgs() << "Writing " << format("%p", R.Value)
875                     << " at " << format("%p", Address)
876                     << " with width " << format("%d", R.Width)
877                     << "\n");
878        Map->insert(std::make_pair(Address, std::make_pair(R.Width, R.Value)));
879      }
880    }
881  }
882}
883
884void DWARFContextInMemory::anchor() { }
885