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>
25 using namespace llvm;
26 using namespace dwarf;
27 using namespace object;
28
29 #define DEBUG_TYPE "dwarf"
30
31 typedef DWARFDebugLine::LineTable DWARFLineTable;
32 typedef DILineInfoSpecifier::FileLineInfoKind FileLineInfoKind;
33 typedef DILineInfoSpecifier::FunctionNameKind FunctionNameKind;
34
dumpPubSection(raw_ostream & OS,StringRef Name,StringRef Data,bool LittleEndian,bool GnuStyle)35 static 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
dumpAccelSection(raw_ostream & OS,StringRef Name,const DWARFSection & Section,StringRef StringSection,bool LittleEndian)66 static 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
dump(raw_ostream & OS,DIDumpType DumpType,bool DumpEH)78 void 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
getCUIndex()276 const 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
getTUIndex()287 const 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
getDebugAbbrev()298 const 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
getDebugAbbrevDWO()309 const 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
getDebugLoc()319 const 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
getDebugLocDWO()331 const 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
getDebugAranges()341 const 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
getDebugFrame()350 const 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
getEHFrame()370 const 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
getDebugMacro()381 const 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
391 const DWARFLineTable *
getLineTableForUnit(DWARFUnit * U)392 DWARFContext::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
parseCompileUnits()416 void DWARFContext::parseCompileUnits() {
417 CUs.parse(*this, getInfoSection());
418 }
419
parseTypeUnits()420 void 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
parseDWOCompileUnits()429 void DWARFContext::parseDWOCompileUnits() {
430 DWOCUs.parseDWO(*this, getInfoDWOSection());
431 }
432
parseDWOTypeUnits()433 void 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
getCompileUnitForOffset(uint32_t Offset)442 DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint32_t Offset) {
443 parseCompileUnits();
444 return CUs.getUnitForOffset(Offset);
445 }
446
getCompileUnitForAddress(uint64_t Address)447 DWARFCompileUnit *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
getFunctionNameForAddress(DWARFCompileUnit * CU,uint64_t Address,FunctionNameKind Kind,std::string & FunctionName)454 static 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
getLineInfoForAddress(uint64_t Address,DILineInfoSpecifier Spec)475 DILineInfo 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
491 DILineInfoTable
getLineInfoForAddressRange(uint64_t Address,uint64_t Size,DILineInfoSpecifier Spec)492 DWARFContext::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
533 DIInliningInfo
getInliningInfoForAddress(uint64_t Address,DILineInfoSpecifier Spec)534 DWARFContext::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
consumeCompressedGnuHeader(StringRef & data,uint64_t & OriginalSize)596 static 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
consumeCompressedZLibHeader(StringRef & Data,uint64_t & OriginalSize,bool IsLE,bool Is64Bit)612 static 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
tryDecompress(StringRef & Name,StringRef & Data,SmallString<32> & Out,bool ZLibStyle,bool IsLE,bool Is64Bit)636 static 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
DWARFContextInMemory(const object::ObjectFile & Obj,const LoadedObjectInfo * L)656 DWARFContextInMemory::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
anchor()884 void DWARFContextInMemory::anchor() { }
885