1 //===-- DWARFContext.cpp --------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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/Support/Compression.h"
17 #include "llvm/Support/Dwarf.h"
18 #include "llvm/Support/Format.h"
19 #include "llvm/Support/Path.h"
20 #include "llvm/Support/raw_ostream.h"
23 using namespace dwarf;
24 using namespace object;
26 #define DEBUG_TYPE "dwarf"
28 typedef DWARFDebugLine::LineTable DWARFLineTable;
29 typedef DILineInfoSpecifier::FileLineInfoKind FileLineInfoKind;
30 typedef DILineInfoSpecifier::FunctionNameKind FunctionNameKind;
32 static void dumpPubSection(raw_ostream &OS, StringRef Name, StringRef Data,
33 bool LittleEndian, bool GnuStyle) {
34 OS << "\n." << Name << " contents:\n";
35 DataExtractor pubNames(Data, LittleEndian, 0);
37 while (pubNames.isValidOffset(offset)) {
38 OS << "length = " << format("0x%08x", pubNames.getU32(&offset));
39 OS << " version = " << format("0x%04x", pubNames.getU16(&offset));
40 OS << " unit_offset = " << format("0x%08x", pubNames.getU32(&offset));
41 OS << " unit_size = " << format("0x%08x", pubNames.getU32(&offset)) << '\n';
43 OS << "Offset Linkage Kind Name\n";
45 OS << "Offset Name\n";
47 while (offset < Data.size()) {
48 uint32_t dieRef = pubNames.getU32(&offset);
51 OS << format("0x%8.8x ", dieRef);
53 PubIndexEntryDescriptor desc(pubNames.getU8(&offset));
54 OS << format("%-8s", dwarf::GDBIndexEntryLinkageString(desc.Linkage))
55 << ' ' << format("%-8s", dwarf::GDBIndexEntryKindString(desc.Kind))
58 OS << '\"' << pubNames.getCStr(&offset) << "\"\n";
63 static void dumpAccelSection(raw_ostream &OS, StringRef Name,
64 const DWARFSection& Section, StringRef StringSection,
66 DataExtractor AccelSection(Section.Data, LittleEndian, 0);
67 DataExtractor StrData(StringSection, LittleEndian, 0);
68 OS << "\n." << Name << " contents:\n";
69 DWARFAcceleratorTable Accel(AccelSection, StrData, Section.Relocs);
75 void DWARFContext::dump(raw_ostream &OS, DIDumpType DumpType) {
76 if (DumpType == DIDT_All || DumpType == DIDT_Abbrev) {
77 OS << ".debug_abbrev contents:\n";
78 getDebugAbbrev()->dump(OS);
81 if (DumpType == DIDT_All || DumpType == DIDT_AbbrevDwo)
82 if (const DWARFDebugAbbrev *D = getDebugAbbrevDWO()) {
83 OS << "\n.debug_abbrev.dwo contents:\n";
87 if (DumpType == DIDT_All || DumpType == DIDT_Info) {
88 OS << "\n.debug_info contents:\n";
89 for (const auto &CU : compile_units())
93 if ((DumpType == DIDT_All || DumpType == DIDT_InfoDwo) &&
94 getNumDWOCompileUnits()) {
95 OS << "\n.debug_info.dwo contents:\n";
96 for (const auto &DWOCU : dwo_compile_units())
100 if ((DumpType == DIDT_All || DumpType == DIDT_Types) && getNumTypeUnits()) {
101 OS << "\n.debug_types contents:\n";
102 for (const auto &TUS : type_unit_sections())
103 for (const auto &TU : TUS)
107 if ((DumpType == DIDT_All || DumpType == DIDT_TypesDwo) &&
108 getNumDWOTypeUnits()) {
109 OS << "\n.debug_types.dwo contents:\n";
110 for (const auto &DWOTUS : dwo_type_unit_sections())
111 for (const auto &DWOTU : DWOTUS)
115 if (DumpType == DIDT_All || DumpType == DIDT_Loc) {
116 OS << "\n.debug_loc contents:\n";
117 getDebugLoc()->dump(OS);
120 if (DumpType == DIDT_All || DumpType == DIDT_LocDwo) {
121 OS << "\n.debug_loc.dwo contents:\n";
122 getDebugLocDWO()->dump(OS);
125 if (DumpType == DIDT_All || DumpType == DIDT_Frames) {
126 OS << "\n.debug_frame contents:\n";
127 getDebugFrame()->dump(OS);
131 if (DumpType == DIDT_All || DumpType == DIDT_Aranges) {
132 OS << "\n.debug_aranges contents:\n";
133 DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0);
134 DWARFDebugArangeSet set;
135 while (set.extract(arangesData, &offset))
139 uint8_t savedAddressByteSize = 0;
140 if (DumpType == DIDT_All || DumpType == DIDT_Line) {
141 OS << "\n.debug_line contents:\n";
142 for (const auto &CU : compile_units()) {
143 savedAddressByteSize = CU->getAddressByteSize();
144 const auto *CUDIE = CU->getUnitDIE();
145 if (CUDIE == nullptr)
147 unsigned stmtOffset = CUDIE->getAttributeValueAsSectionOffset(
148 CU.get(), DW_AT_stmt_list, -1U);
149 if (stmtOffset != -1U) {
150 DataExtractor lineData(getLineSection().Data, isLittleEndian(),
151 savedAddressByteSize);
152 DWARFDebugLine::LineTable LineTable;
153 LineTable.parse(lineData, &getLineSection().Relocs, &stmtOffset);
159 if (DumpType == DIDT_All || DumpType == DIDT_CUIndex) {
160 OS << "\n.debug_cu_index contents:\n";
161 DataExtractor CUIndexData(getCUIndexSection(), isLittleEndian(),
162 savedAddressByteSize);
163 DWARFUnitIndex CUIndex;
164 if (CUIndex.parse(CUIndexData))
168 if (DumpType == DIDT_All || DumpType == DIDT_TUIndex) {
169 OS << "\n.debug_tu_index contents:\n";
170 DataExtractor TUIndexData(getTUIndexSection(), isLittleEndian(),
171 savedAddressByteSize);
172 DWARFUnitIndex TUIndex;
173 if (TUIndex.parse(TUIndexData))
177 if (DumpType == DIDT_All || DumpType == DIDT_LineDwo) {
178 OS << "\n.debug_line.dwo contents:\n";
179 unsigned stmtOffset = 0;
180 DataExtractor lineData(getLineDWOSection().Data, isLittleEndian(),
181 savedAddressByteSize);
182 DWARFDebugLine::LineTable LineTable;
183 while (LineTable.Prologue.parse(lineData, &stmtOffset)) {
189 if (DumpType == DIDT_All || DumpType == DIDT_Str) {
190 OS << "\n.debug_str contents:\n";
191 DataExtractor strData(getStringSection(), isLittleEndian(), 0);
193 uint32_t strOffset = 0;
194 while (const char *s = strData.getCStr(&offset)) {
195 OS << format("0x%8.8x: \"%s\"\n", strOffset, s);
200 if ((DumpType == DIDT_All || DumpType == DIDT_StrDwo) &&
201 !getStringDWOSection().empty()) {
202 OS << "\n.debug_str.dwo contents:\n";
203 DataExtractor strDWOData(getStringDWOSection(), isLittleEndian(), 0);
205 uint32_t strDWOOffset = 0;
206 while (const char *s = strDWOData.getCStr(&offset)) {
207 OS << format("0x%8.8x: \"%s\"\n", strDWOOffset, s);
208 strDWOOffset = offset;
212 if (DumpType == DIDT_All || DumpType == DIDT_Ranges) {
213 OS << "\n.debug_ranges contents:\n";
214 // In fact, different compile units may have different address byte
215 // sizes, but for simplicity we just use the address byte size of the last
216 // compile unit (there is no easy and fast way to associate address range
217 // list and the compile unit it describes).
218 DataExtractor rangesData(getRangeSection(), isLittleEndian(),
219 savedAddressByteSize);
221 DWARFDebugRangeList rangeList;
222 while (rangeList.extract(rangesData, &offset))
226 if (DumpType == DIDT_All || DumpType == DIDT_Pubnames)
227 dumpPubSection(OS, "debug_pubnames", getPubNamesSection(),
228 isLittleEndian(), false);
230 if (DumpType == DIDT_All || DumpType == DIDT_Pubtypes)
231 dumpPubSection(OS, "debug_pubtypes", getPubTypesSection(),
232 isLittleEndian(), false);
234 if (DumpType == DIDT_All || DumpType == DIDT_GnuPubnames)
235 dumpPubSection(OS, "debug_gnu_pubnames", getGnuPubNamesSection(),
236 isLittleEndian(), true /* GnuStyle */);
238 if (DumpType == DIDT_All || DumpType == DIDT_GnuPubtypes)
239 dumpPubSection(OS, "debug_gnu_pubtypes", getGnuPubTypesSection(),
240 isLittleEndian(), true /* GnuStyle */);
242 if ((DumpType == DIDT_All || DumpType == DIDT_StrOffsetsDwo) &&
243 !getStringOffsetDWOSection().empty()) {
244 OS << "\n.debug_str_offsets.dwo contents:\n";
245 DataExtractor strOffsetExt(getStringOffsetDWOSection(), isLittleEndian(),
248 uint64_t size = getStringOffsetDWOSection().size();
249 while (offset < size) {
250 OS << format("0x%8.8x: ", offset);
251 OS << format("%8.8x\n", strOffsetExt.getU32(&offset));
255 if (DumpType == DIDT_All || DumpType == DIDT_AppleNames)
256 dumpAccelSection(OS, "apple_names", getAppleNamesSection(),
257 getStringSection(), isLittleEndian());
259 if (DumpType == DIDT_All || DumpType == DIDT_AppleTypes)
260 dumpAccelSection(OS, "apple_types", getAppleTypesSection(),
261 getStringSection(), isLittleEndian());
263 if (DumpType == DIDT_All || DumpType == DIDT_AppleNamespaces)
264 dumpAccelSection(OS, "apple_namespaces", getAppleNamespacesSection(),
265 getStringSection(), isLittleEndian());
267 if (DumpType == DIDT_All || DumpType == DIDT_AppleObjC)
268 dumpAccelSection(OS, "apple_objc", getAppleObjCSection(),
269 getStringSection(), isLittleEndian());
272 const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
276 DataExtractor abbrData(getAbbrevSection(), isLittleEndian(), 0);
278 Abbrev.reset(new DWARFDebugAbbrev());
279 Abbrev->extract(abbrData);
283 const DWARFDebugAbbrev *DWARFContext::getDebugAbbrevDWO() {
285 return AbbrevDWO.get();
287 DataExtractor abbrData(getAbbrevDWOSection(), isLittleEndian(), 0);
288 AbbrevDWO.reset(new DWARFDebugAbbrev());
289 AbbrevDWO->extract(abbrData);
290 return AbbrevDWO.get();
293 const DWARFDebugLoc *DWARFContext::getDebugLoc() {
297 DataExtractor LocData(getLocSection().Data, isLittleEndian(), 0);
298 Loc.reset(new DWARFDebugLoc(getLocSection().Relocs));
299 // assume all compile units have the same address byte size
300 if (getNumCompileUnits())
301 Loc->parse(LocData, getCompileUnitAtIndex(0)->getAddressByteSize());
305 const DWARFDebugLocDWO *DWARFContext::getDebugLocDWO() {
309 DataExtractor LocData(getLocDWOSection().Data, isLittleEndian(), 0);
310 LocDWO.reset(new DWARFDebugLocDWO());
311 LocDWO->parse(LocData);
315 const DWARFDebugAranges *DWARFContext::getDebugAranges() {
317 return Aranges.get();
319 Aranges.reset(new DWARFDebugAranges());
320 Aranges->generate(this);
321 return Aranges.get();
324 const DWARFDebugFrame *DWARFContext::getDebugFrame() {
326 return DebugFrame.get();
328 // There's a "bug" in the DWARFv3 standard with respect to the target address
329 // size within debug frame sections. While DWARF is supposed to be independent
330 // of its container, FDEs have fields with size being "target address size",
331 // which isn't specified in DWARF in general. It's only specified for CUs, but
332 // .eh_frame can appear without a .debug_info section. Follow the example of
333 // other tools (libdwarf) and extract this from the container (ObjectFile
334 // provides this information). This problem is fixed in DWARFv4
335 // See this dwarf-discuss discussion for more details:
336 // http://lists.dwarfstd.org/htdig.cgi/dwarf-discuss-dwarfstd.org/2011-December/001173.html
337 DataExtractor debugFrameData(getDebugFrameSection(), isLittleEndian(),
339 DebugFrame.reset(new DWARFDebugFrame());
340 DebugFrame->parse(debugFrameData);
341 return DebugFrame.get();
344 const DWARFLineTable *
345 DWARFContext::getLineTableForUnit(DWARFUnit *U) {
347 Line.reset(new DWARFDebugLine(&getLineSection().Relocs));
348 const auto *UnitDIE = U->getUnitDIE();
349 if (UnitDIE == nullptr)
351 unsigned stmtOffset =
352 UnitDIE->getAttributeValueAsSectionOffset(U, DW_AT_stmt_list, -1U);
353 if (stmtOffset == -1U)
354 return nullptr; // No line table for this compile unit.
356 // See if the line table is cached.
357 if (const DWARFLineTable *lt = Line->getLineTable(stmtOffset))
360 // We have to parse it first.
361 DataExtractor lineData(getLineSection().Data, isLittleEndian(),
362 U->getAddressByteSize());
363 return Line->getOrParseLineTable(lineData, stmtOffset);
366 void DWARFContext::parseCompileUnits() {
367 CUs.parse(*this, getInfoSection());
370 void DWARFContext::parseTypeUnits() {
373 for (const auto &I : getTypesSections()) {
375 TUs.back().parse(*this, I.second);
379 void DWARFContext::parseDWOCompileUnits() {
380 DWOCUs.parseDWO(*this, getInfoDWOSection());
383 void DWARFContext::parseDWOTypeUnits() {
386 for (const auto &I : getTypesDWOSections()) {
387 DWOTUs.emplace_back();
388 DWOTUs.back().parseDWO(*this, I.second);
392 DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint32_t Offset) {
394 return CUs.getUnitForOffset(Offset);
397 DWARFCompileUnit *DWARFContext::getCompileUnitForAddress(uint64_t Address) {
398 // First, get the offset of the compile unit.
399 uint32_t CUOffset = getDebugAranges()->findAddress(Address);
400 // Retrieve the compile unit.
401 return getCompileUnitForOffset(CUOffset);
404 static bool getFunctionNameForAddress(DWARFCompileUnit *CU, uint64_t Address,
405 FunctionNameKind Kind,
406 std::string &FunctionName) {
407 if (Kind == FunctionNameKind::None)
409 // The address may correspond to instruction in some inlined function,
410 // so we have to build the chain of inlined functions and take the
411 // name of the topmost function in it.
412 const DWARFDebugInfoEntryInlinedChain &InlinedChain =
413 CU->getInlinedChainForAddress(Address);
414 if (InlinedChain.DIEs.size() == 0)
416 const DWARFDebugInfoEntryMinimal &TopFunctionDIE = InlinedChain.DIEs[0];
417 if (const char *Name =
418 TopFunctionDIE.getSubroutineName(InlinedChain.U, Kind)) {
425 DILineInfo DWARFContext::getLineInfoForAddress(uint64_t Address,
426 DILineInfoSpecifier Spec) {
429 DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
432 getFunctionNameForAddress(CU, Address, Spec.FNKind, Result.FunctionName);
433 if (Spec.FLIKind != FileLineInfoKind::None) {
434 if (const DWARFLineTable *LineTable = getLineTableForUnit(CU))
435 LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
436 Spec.FLIKind, Result);
442 DWARFContext::getLineInfoForAddressRange(uint64_t Address, uint64_t Size,
443 DILineInfoSpecifier Spec) {
444 DILineInfoTable Lines;
445 DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
449 std::string FunctionName = "<invalid>";
450 getFunctionNameForAddress(CU, Address, Spec.FNKind, FunctionName);
452 // If the Specifier says we don't need FileLineInfo, just
453 // return the top-most function at the starting address.
454 if (Spec.FLIKind == FileLineInfoKind::None) {
456 Result.FunctionName = FunctionName;
457 Lines.push_back(std::make_pair(Address, Result));
461 const DWARFLineTable *LineTable = getLineTableForUnit(CU);
463 // Get the index of row we're looking for in the line table.
464 std::vector<uint32_t> RowVector;
465 if (!LineTable->lookupAddressRange(Address, Size, RowVector))
468 for (uint32_t RowIndex : RowVector) {
469 // Take file number and line/column from the row.
470 const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
472 LineTable->getFileNameByIndex(Row.File, CU->getCompilationDir(),
473 Spec.FLIKind, Result.FileName);
474 Result.FunctionName = FunctionName;
475 Result.Line = Row.Line;
476 Result.Column = Row.Column;
477 Lines.push_back(std::make_pair(Row.Address, Result));
484 DWARFContext::getInliningInfoForAddress(uint64_t Address,
485 DILineInfoSpecifier Spec) {
486 DIInliningInfo InliningInfo;
488 DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
492 const DWARFLineTable *LineTable = nullptr;
493 const DWARFDebugInfoEntryInlinedChain &InlinedChain =
494 CU->getInlinedChainForAddress(Address);
495 if (InlinedChain.DIEs.size() == 0) {
496 // If there is no DIE for address (e.g. it is in unavailable .dwo file),
497 // try to at least get file/line info from symbol table.
498 if (Spec.FLIKind != FileLineInfoKind::None) {
500 LineTable = getLineTableForUnit(CU);
502 LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
503 Spec.FLIKind, Frame))
504 InliningInfo.addFrame(Frame);
509 uint32_t CallFile = 0, CallLine = 0, CallColumn = 0;
510 for (uint32_t i = 0, n = InlinedChain.DIEs.size(); i != n; i++) {
511 const DWARFDebugInfoEntryMinimal &FunctionDIE = InlinedChain.DIEs[i];
513 // Get function name if necessary.
514 if (const char *Name =
515 FunctionDIE.getSubroutineName(InlinedChain.U, Spec.FNKind))
516 Frame.FunctionName = Name;
517 if (Spec.FLIKind != FileLineInfoKind::None) {
519 // For the topmost frame, initialize the line table of this
520 // compile unit and fetch file/line info from it.
521 LineTable = getLineTableForUnit(CU);
522 // For the topmost routine, get file/line info from line table.
524 LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
525 Spec.FLIKind, Frame);
527 // Otherwise, use call file, call line and call column from
528 // previous DIE in inlined chain.
530 LineTable->getFileNameByIndex(CallFile, CU->getCompilationDir(),
531 Spec.FLIKind, Frame.FileName);
532 Frame.Line = CallLine;
533 Frame.Column = CallColumn;
535 // Get call file/line/column of a current DIE.
537 FunctionDIE.getCallerFrame(InlinedChain.U, CallFile, CallLine,
541 InliningInfo.addFrame(Frame);
546 static bool consumeCompressedDebugSectionHeader(StringRef &data,
547 uint64_t &OriginalSize) {
548 // Consume "ZLIB" prefix.
549 if (!data.startswith("ZLIB"))
551 data = data.substr(4);
552 // Consume uncompressed section size (big-endian 8 bytes).
553 DataExtractor extractor(data, false, 8);
555 OriginalSize = extractor.getU64(&Offset);
558 data = data.substr(Offset);
562 DWARFContextInMemory::DWARFContextInMemory(const object::ObjectFile &Obj,
563 const LoadedObjectInfo *L)
564 : IsLittleEndian(Obj.isLittleEndian()),
565 AddressSize(Obj.getBytesInAddress()) {
566 for (const SectionRef &Section : Obj.sections()) {
568 Section.getName(name);
569 // Skip BSS and Virtual sections, they aren't interesting.
570 bool IsBSS = Section.isBSS();
573 bool IsVirtual = Section.isVirtual();
578 section_iterator RelocatedSection = Section.getRelocatedSection();
579 // Try to obtain an already relocated version of this section.
580 // Else use the unrelocated section from the object file. We'll have to
581 // apply relocations ourselves later.
582 if (!L || !L->getLoadedSectionContents(*RelocatedSection,data))
583 Section.getContents(data);
585 name = name.substr(name.find_first_not_of("._")); // Skip . and _ prefixes.
587 // Check if debug info section is compressed with zlib.
588 if (name.startswith("zdebug_")) {
589 uint64_t OriginalSize;
590 if (!zlib::isAvailable() ||
591 !consumeCompressedDebugSectionHeader(data, OriginalSize))
593 UncompressedSections.resize(UncompressedSections.size() + 1);
594 if (zlib::uncompress(data, UncompressedSections.back(), OriginalSize) !=
596 UncompressedSections.pop_back();
599 // Make data point to uncompressed section contents and save its contents.
600 name = name.substr(1);
601 data = UncompressedSections.back();
604 StringRef *SectionData =
605 StringSwitch<StringRef *>(name)
606 .Case("debug_info", &InfoSection.Data)
607 .Case("debug_abbrev", &AbbrevSection)
608 .Case("debug_loc", &LocSection.Data)
609 .Case("debug_line", &LineSection.Data)
610 .Case("debug_aranges", &ARangeSection)
611 .Case("debug_frame", &DebugFrameSection)
612 .Case("debug_str", &StringSection)
613 .Case("debug_ranges", &RangeSection)
614 .Case("debug_pubnames", &PubNamesSection)
615 .Case("debug_pubtypes", &PubTypesSection)
616 .Case("debug_gnu_pubnames", &GnuPubNamesSection)
617 .Case("debug_gnu_pubtypes", &GnuPubTypesSection)
618 .Case("debug_info.dwo", &InfoDWOSection.Data)
619 .Case("debug_abbrev.dwo", &AbbrevDWOSection)
620 .Case("debug_loc.dwo", &LocDWOSection.Data)
621 .Case("debug_line.dwo", &LineDWOSection.Data)
622 .Case("debug_str.dwo", &StringDWOSection)
623 .Case("debug_str_offsets.dwo", &StringOffsetDWOSection)
624 .Case("debug_addr", &AddrSection)
625 .Case("apple_names", &AppleNamesSection.Data)
626 .Case("apple_types", &AppleTypesSection.Data)
627 .Case("apple_namespaces", &AppleNamespacesSection.Data)
628 .Case("apple_namespac", &AppleNamespacesSection.Data)
629 .Case("apple_objc", &AppleObjCSection.Data)
630 .Case("debug_cu_index", &CUIndexSection)
631 .Case("debug_tu_index", &TUIndexSection)
632 // Any more debug info sections go here.
636 if (name == "debug_ranges") {
637 // FIXME: Use the other dwo range section when we emit it.
638 RangeDWOSection = data;
640 } else if (name == "debug_types") {
641 // Find debug_types data by section rather than name as there are
642 // multiple, comdat grouped, debug_types sections.
643 TypesSections[Section].Data = data;
644 } else if (name == "debug_types.dwo") {
645 TypesDWOSections[Section].Data = data;
648 if (RelocatedSection == Obj.section_end())
651 StringRef RelSecName;
652 StringRef RelSecData;
653 RelocatedSection->getName(RelSecName);
655 // If the section we're relocating was relocated already by the JIT,
656 // then we used the relocated version above, so we do not need to process
657 // relocations for it now.
658 if (L && L->getLoadedSectionContents(*RelocatedSection,RelSecData))
661 // In Mach-o files, the relocations do not need to be applied if
662 // there is no load offset to apply. The value read at the
663 // relocation point already factors in the section address
664 // (actually applying the relocations will produce wrong results
665 // as the section address will be added twice).
666 if (!L && dyn_cast<MachOObjectFile>(&Obj))
669 RelSecName = RelSecName.substr(
670 RelSecName.find_first_not_of("._")); // Skip . and _ prefixes.
672 // TODO: Add support for relocations in other sections as needed.
673 // Record relocations for the debug_info and debug_line sections.
674 RelocAddrMap *Map = StringSwitch<RelocAddrMap*>(RelSecName)
675 .Case("debug_info", &InfoSection.Relocs)
676 .Case("debug_loc", &LocSection.Relocs)
677 .Case("debug_info.dwo", &InfoDWOSection.Relocs)
678 .Case("debug_line", &LineSection.Relocs)
679 .Case("apple_names", &AppleNamesSection.Relocs)
680 .Case("apple_types", &AppleTypesSection.Relocs)
681 .Case("apple_namespaces", &AppleNamespacesSection.Relocs)
682 .Case("apple_namespac", &AppleNamespacesSection.Relocs)
683 .Case("apple_objc", &AppleObjCSection.Relocs)
686 // Find debug_types relocs by section rather than name as there are
687 // multiple, comdat grouped, debug_types sections.
688 if (RelSecName == "debug_types")
689 Map = &TypesSections[*RelocatedSection].Relocs;
690 else if (RelSecName == "debug_types.dwo")
691 Map = &TypesDWOSections[*RelocatedSection].Relocs;
696 if (Section.relocation_begin() != Section.relocation_end()) {
697 uint64_t SectionSize = RelocatedSection->getSize();
698 for (const RelocationRef &Reloc : Section.relocations()) {
699 uint64_t Address = Reloc.getOffset();
700 uint64_t Type = Reloc.getType();
701 uint64_t SymAddr = 0;
702 uint64_t SectionLoadAddress = 0;
703 object::symbol_iterator Sym = Reloc.getSymbol();
704 object::section_iterator RSec = Obj.section_end();
706 // First calculate the address of the symbol or section as it appears
708 if (Sym != Obj.symbol_end()) {
709 ErrorOr<uint64_t> SymAddrOrErr = Sym->getAddress();
710 if (std::error_code EC = SymAddrOrErr.getError()) {
711 errs() << "error: failed to compute symbol address: "
712 << EC.message() << '\n';
715 SymAddr = *SymAddrOrErr;
716 // Also remember what section this symbol is in for later
717 RSec = *Sym->getSection();
718 } else if (auto *MObj = dyn_cast<MachOObjectFile>(&Obj)) {
719 // MachO also has relocations that point to sections and
720 // scattered relocations.
721 auto RelocInfo = MObj->getRelocation(Reloc.getRawDataRefImpl());
722 if (MObj->isRelocationScattered(RelocInfo)) {
723 // FIXME: it's not clear how to correctly handle scattered
727 RSec = MObj->getRelocationSection(Reloc.getRawDataRefImpl());
728 SymAddr = RSec->getAddress();
732 // If we are given load addresses for the sections, we need to adjust:
733 // SymAddr = (Address of Symbol Or Section in File) -
734 // (Address of Section in File) +
735 // (Load Address of Section)
736 if (L != nullptr && RSec != Obj.section_end()) {
737 // RSec is now either the section being targeted or the section
738 // containing the symbol being targeted. In either case,
739 // we need to perform the same computation.
741 RSec->getName(SecName);
742 // llvm::dbgs() << "Name: '" << SecName
743 // << "', RSec: " << RSec->getRawDataRefImpl()
744 // << ", Section: " << Section.getRawDataRefImpl() << "\n";
745 SectionLoadAddress = L->getSectionLoadAddress(*RSec);
746 if (SectionLoadAddress != 0)
747 SymAddr += SectionLoadAddress - RSec->getAddress();
750 object::RelocVisitor V(Obj);
751 object::RelocToApply R(V.visit(Type, Reloc, SymAddr));
753 SmallString<32> Name;
754 Reloc.getTypeName(Name);
755 errs() << "error: failed to compute relocation: "
760 if (Address + R.Width > SectionSize) {
761 errs() << "error: " << R.Width << "-byte relocation starting "
762 << Address << " bytes into section " << name << " which is "
763 << SectionSize << " bytes long.\n";
767 errs() << "error: can't handle a relocation of more than 8 bytes at "
771 DEBUG(dbgs() << "Writing " << format("%p", R.Value)
772 << " at " << format("%p", Address)
773 << " with width " << format("%d", R.Width)
775 Map->insert(std::make_pair(Address, std::make_pair(R.Width, R.Value)));
781 void DWARFContextInMemory::anchor() { }