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 "DWARFContext.h"
11 #include "DWARFDebugArangeSet.h"
13 #include "llvm/ADT/SmallString.h"
14 #include "llvm/ADT/StringSwitch.h"
15 #include "llvm/Support/Compression.h"
16 #include "llvm/Support/Dwarf.h"
17 #include "llvm/Support/Format.h"
18 #include "llvm/Support/Path.h"
19 #include "llvm/Support/raw_ostream.h"
22 using namespace dwarf;
23 using namespace object;
25 #define DEBUG_TYPE "dwarf"
27 typedef DWARFDebugLine::LineTable DWARFLineTable;
28 typedef DILineInfoSpecifier::FileLineInfoKind FileLineInfoKind;
29 typedef DILineInfoSpecifier::FunctionNameKind FunctionNameKind;
31 static void dumpPubSection(raw_ostream &OS, StringRef Name, StringRef Data,
32 bool LittleEndian, bool GnuStyle) {
33 OS << "\n." << Name << " contents:\n";
34 DataExtractor pubNames(Data, LittleEndian, 0);
36 while (pubNames.isValidOffset(offset)) {
37 OS << "length = " << format("0x%08x", pubNames.getU32(&offset));
38 OS << " version = " << format("0x%04x", pubNames.getU16(&offset));
39 OS << " unit_offset = " << format("0x%08x", pubNames.getU32(&offset));
40 OS << " unit_size = " << format("0x%08x", pubNames.getU32(&offset)) << '\n';
42 OS << "Offset Linkage Kind Name\n";
44 OS << "Offset Name\n";
46 while (offset < Data.size()) {
47 uint32_t dieRef = pubNames.getU32(&offset);
50 OS << format("0x%8.8x ", dieRef);
52 PubIndexEntryDescriptor desc(pubNames.getU8(&offset));
53 OS << format("%-8s", dwarf::GDBIndexEntryLinkageString(desc.Linkage))
54 << ' ' << format("%-8s", dwarf::GDBIndexEntryKindString(desc.Kind))
57 OS << '\"' << pubNames.getCStr(&offset) << "\"\n";
62 void DWARFContext::dump(raw_ostream &OS, DIDumpType DumpType) {
63 if (DumpType == DIDT_All || DumpType == DIDT_Abbrev) {
64 OS << ".debug_abbrev contents:\n";
65 getDebugAbbrev()->dump(OS);
68 if (DumpType == DIDT_All || DumpType == DIDT_AbbrevDwo)
69 if (const DWARFDebugAbbrev *D = getDebugAbbrevDWO()) {
70 OS << "\n.debug_abbrev.dwo contents:\n";
74 if (DumpType == DIDT_All || DumpType == DIDT_Info) {
75 OS << "\n.debug_info contents:\n";
76 for (const auto &CU : compile_units())
80 if ((DumpType == DIDT_All || DumpType == DIDT_InfoDwo) &&
81 getNumDWOCompileUnits()) {
82 OS << "\n.debug_info.dwo contents:\n";
83 for (const auto &DWOCU : dwo_compile_units())
87 if ((DumpType == DIDT_All || DumpType == DIDT_Types) && getNumTypeUnits()) {
88 OS << "\n.debug_types contents:\n";
89 for (const auto &TUS : type_unit_sections())
90 for (const auto &TU : TUS)
94 if ((DumpType == DIDT_All || DumpType == DIDT_TypesDwo) &&
95 getNumDWOTypeUnits()) {
96 OS << "\n.debug_types.dwo contents:\n";
97 for (const auto &DWOTUS : dwo_type_unit_sections())
98 for (const auto &DWOTU : DWOTUS)
102 if (DumpType == DIDT_All || DumpType == DIDT_Loc) {
103 OS << "\n.debug_loc contents:\n";
104 getDebugLoc()->dump(OS);
107 if (DumpType == DIDT_All || DumpType == DIDT_LocDwo) {
108 OS << "\n.debug_loc.dwo contents:\n";
109 getDebugLocDWO()->dump(OS);
112 if (DumpType == DIDT_All || DumpType == DIDT_Frames) {
113 OS << "\n.debug_frame contents:\n";
114 getDebugFrame()->dump(OS);
118 if (DumpType == DIDT_All || DumpType == DIDT_Aranges) {
119 OS << "\n.debug_aranges contents:\n";
120 DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0);
121 DWARFDebugArangeSet set;
122 while (set.extract(arangesData, &offset))
126 uint8_t savedAddressByteSize = 0;
127 if (DumpType == DIDT_All || DumpType == DIDT_Line) {
128 OS << "\n.debug_line contents:\n";
129 for (const auto &CU : compile_units()) {
130 savedAddressByteSize = CU->getAddressByteSize();
131 unsigned stmtOffset =
132 CU->getCompileUnitDIE()->getAttributeValueAsSectionOffset(
133 CU.get(), DW_AT_stmt_list, -1U);
134 if (stmtOffset != -1U) {
135 DataExtractor lineData(getLineSection().Data, isLittleEndian(),
136 savedAddressByteSize);
137 DWARFDebugLine::LineTable LineTable;
138 LineTable.parse(lineData, &getLineSection().Relocs, &stmtOffset);
144 if (DumpType == DIDT_All || DumpType == DIDT_LineDwo) {
145 OS << "\n.debug_line.dwo contents:\n";
146 unsigned stmtOffset = 0;
147 DataExtractor lineData(getLineDWOSection().Data, isLittleEndian(),
148 savedAddressByteSize);
149 DWARFDebugLine::LineTable LineTable;
150 while (LineTable.Prologue.parse(lineData, &stmtOffset)) {
156 if (DumpType == DIDT_All || DumpType == DIDT_Str) {
157 OS << "\n.debug_str contents:\n";
158 DataExtractor strData(getStringSection(), isLittleEndian(), 0);
160 uint32_t strOffset = 0;
161 while (const char *s = strData.getCStr(&offset)) {
162 OS << format("0x%8.8x: \"%s\"\n", strOffset, s);
167 if ((DumpType == DIDT_All || DumpType == DIDT_StrDwo) &&
168 !getStringDWOSection().empty()) {
169 OS << "\n.debug_str.dwo contents:\n";
170 DataExtractor strDWOData(getStringDWOSection(), isLittleEndian(), 0);
172 uint32_t strDWOOffset = 0;
173 while (const char *s = strDWOData.getCStr(&offset)) {
174 OS << format("0x%8.8x: \"%s\"\n", strDWOOffset, s);
175 strDWOOffset = offset;
179 if (DumpType == DIDT_All || DumpType == DIDT_Ranges) {
180 OS << "\n.debug_ranges contents:\n";
181 // In fact, different compile units may have different address byte
182 // sizes, but for simplicity we just use the address byte size of the last
183 // compile unit (there is no easy and fast way to associate address range
184 // list and the compile unit it describes).
185 DataExtractor rangesData(getRangeSection(), isLittleEndian(),
186 savedAddressByteSize);
188 DWARFDebugRangeList rangeList;
189 while (rangeList.extract(rangesData, &offset))
193 if (DumpType == DIDT_All || DumpType == DIDT_Pubnames)
194 dumpPubSection(OS, "debug_pubnames", getPubNamesSection(),
195 isLittleEndian(), false);
197 if (DumpType == DIDT_All || DumpType == DIDT_Pubtypes)
198 dumpPubSection(OS, "debug_pubtypes", getPubTypesSection(),
199 isLittleEndian(), false);
201 if (DumpType == DIDT_All || DumpType == DIDT_GnuPubnames)
202 dumpPubSection(OS, "debug_gnu_pubnames", getGnuPubNamesSection(),
203 isLittleEndian(), true /* GnuStyle */);
205 if (DumpType == DIDT_All || DumpType == DIDT_GnuPubtypes)
206 dumpPubSection(OS, "debug_gnu_pubtypes", getGnuPubTypesSection(),
207 isLittleEndian(), true /* GnuStyle */);
209 if ((DumpType == DIDT_All || DumpType == DIDT_StrOffsetsDwo) &&
210 !getStringOffsetDWOSection().empty()) {
211 OS << "\n.debug_str_offsets.dwo contents:\n";
212 DataExtractor strOffsetExt(getStringOffsetDWOSection(), isLittleEndian(),
215 uint64_t size = getStringOffsetDWOSection().size();
216 while (offset < size) {
217 OS << format("0x%8.8x: ", offset);
218 OS << format("%8.8x\n", strOffsetExt.getU32(&offset));
223 const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
227 DataExtractor abbrData(getAbbrevSection(), isLittleEndian(), 0);
229 Abbrev.reset(new DWARFDebugAbbrev());
230 Abbrev->extract(abbrData);
234 const DWARFDebugAbbrev *DWARFContext::getDebugAbbrevDWO() {
236 return AbbrevDWO.get();
238 DataExtractor abbrData(getAbbrevDWOSection(), isLittleEndian(), 0);
239 AbbrevDWO.reset(new DWARFDebugAbbrev());
240 AbbrevDWO->extract(abbrData);
241 return AbbrevDWO.get();
244 const DWARFDebugLoc *DWARFContext::getDebugLoc() {
248 DataExtractor LocData(getLocSection().Data, isLittleEndian(), 0);
249 Loc.reset(new DWARFDebugLoc(getLocSection().Relocs));
250 // assume all compile units have the same address byte size
251 if (getNumCompileUnits())
252 Loc->parse(LocData, getCompileUnitAtIndex(0)->getAddressByteSize());
256 const DWARFDebugLocDWO *DWARFContext::getDebugLocDWO() {
260 DataExtractor LocData(getLocDWOSection().Data, isLittleEndian(), 0);
261 LocDWO.reset(new DWARFDebugLocDWO());
262 LocDWO->parse(LocData);
266 const DWARFDebugAranges *DWARFContext::getDebugAranges() {
268 return Aranges.get();
270 Aranges.reset(new DWARFDebugAranges());
271 Aranges->generate(this);
272 return Aranges.get();
275 const DWARFDebugFrame *DWARFContext::getDebugFrame() {
277 return DebugFrame.get();
279 // There's a "bug" in the DWARFv3 standard with respect to the target address
280 // size within debug frame sections. While DWARF is supposed to be independent
281 // of its container, FDEs have fields with size being "target address size",
282 // which isn't specified in DWARF in general. It's only specified for CUs, but
283 // .eh_frame can appear without a .debug_info section. Follow the example of
284 // other tools (libdwarf) and extract this from the container (ObjectFile
285 // provides this information). This problem is fixed in DWARFv4
286 // See this dwarf-discuss discussion for more details:
287 // http://lists.dwarfstd.org/htdig.cgi/dwarf-discuss-dwarfstd.org/2011-December/001173.html
288 DataExtractor debugFrameData(getDebugFrameSection(), isLittleEndian(),
290 DebugFrame.reset(new DWARFDebugFrame());
291 DebugFrame->parse(debugFrameData);
292 return DebugFrame.get();
295 const DWARFLineTable *
296 DWARFContext::getLineTableForUnit(DWARFUnit *cu) {
298 Line.reset(new DWARFDebugLine(&getLineSection().Relocs));
300 unsigned stmtOffset =
301 cu->getCompileUnitDIE()->getAttributeValueAsSectionOffset(
302 cu, DW_AT_stmt_list, -1U);
303 if (stmtOffset == -1U)
304 return nullptr; // No line table for this compile unit.
306 // See if the line table is cached.
307 if (const DWARFLineTable *lt = Line->getLineTable(stmtOffset))
310 // We have to parse it first.
311 DataExtractor lineData(getLineSection().Data, isLittleEndian(),
312 cu->getAddressByteSize());
313 return Line->getOrParseLineTable(lineData, stmtOffset);
316 void DWARFContext::parseCompileUnits() {
317 CUs.parse(*this, getInfoSection());
320 void DWARFContext::parseTypeUnits() {
323 for (const auto &I : getTypesSections()) {
324 TUs.push_back(DWARFUnitSection<DWARFTypeUnit>());
325 TUs.back().parse(*this, I.second);
329 void DWARFContext::parseDWOCompileUnits() {
330 DWOCUs.parseDWO(*this, getInfoDWOSection());
333 void DWARFContext::parseDWOTypeUnits() {
336 for (const auto &I : getTypesDWOSections()) {
337 DWOTUs.push_back(DWARFUnitSection<DWARFTypeUnit>());
338 DWOTUs.back().parseDWO(*this, I.second);
342 DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint32_t Offset) {
344 return CUs.getUnitForOffset(Offset);
347 DWARFCompileUnit *DWARFContext::getCompileUnitForAddress(uint64_t Address) {
348 // First, get the offset of the compile unit.
349 uint32_t CUOffset = getDebugAranges()->findAddress(Address);
350 // Retrieve the compile unit.
351 return getCompileUnitForOffset(CUOffset);
354 static bool getFunctionNameForAddress(DWARFCompileUnit *CU, uint64_t Address,
355 FunctionNameKind Kind,
356 std::string &FunctionName) {
357 if (Kind == FunctionNameKind::None)
359 // The address may correspond to instruction in some inlined function,
360 // so we have to build the chain of inlined functions and take the
361 // name of the topmost function in it.
362 const DWARFDebugInfoEntryInlinedChain &InlinedChain =
363 CU->getInlinedChainForAddress(Address);
364 if (InlinedChain.DIEs.size() == 0)
366 const DWARFDebugInfoEntryMinimal &TopFunctionDIE = InlinedChain.DIEs[0];
367 if (const char *Name =
368 TopFunctionDIE.getSubroutineName(InlinedChain.U, Kind)) {
375 DILineInfo DWARFContext::getLineInfoForAddress(uint64_t Address,
376 DILineInfoSpecifier Spec) {
379 DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
382 getFunctionNameForAddress(CU, Address, Spec.FNKind, Result.FunctionName);
383 if (Spec.FLIKind != FileLineInfoKind::None) {
384 if (const DWARFLineTable *LineTable = getLineTableForUnit(CU))
385 LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
386 Spec.FLIKind, Result);
392 DWARFContext::getLineInfoForAddressRange(uint64_t Address, uint64_t Size,
393 DILineInfoSpecifier Spec) {
394 DILineInfoTable Lines;
395 DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
399 std::string FunctionName = "<invalid>";
400 getFunctionNameForAddress(CU, Address, Spec.FNKind, FunctionName);
402 // If the Specifier says we don't need FileLineInfo, just
403 // return the top-most function at the starting address.
404 if (Spec.FLIKind == FileLineInfoKind::None) {
406 Result.FunctionName = FunctionName;
407 Lines.push_back(std::make_pair(Address, Result));
411 const DWARFLineTable *LineTable = getLineTableForUnit(CU);
413 // Get the index of row we're looking for in the line table.
414 std::vector<uint32_t> RowVector;
415 if (!LineTable->lookupAddressRange(Address, Size, RowVector))
418 for (uint32_t RowIndex : RowVector) {
419 // Take file number and line/column from the row.
420 const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
422 LineTable->getFileNameByIndex(Row.File, CU->getCompilationDir(),
423 Spec.FLIKind, Result.FileName);
424 Result.FunctionName = FunctionName;
425 Result.Line = Row.Line;
426 Result.Column = Row.Column;
427 Lines.push_back(std::make_pair(Row.Address, Result));
434 DWARFContext::getInliningInfoForAddress(uint64_t Address,
435 DILineInfoSpecifier Spec) {
436 DIInliningInfo InliningInfo;
438 DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
442 const DWARFLineTable *LineTable = nullptr;
443 const DWARFDebugInfoEntryInlinedChain &InlinedChain =
444 CU->getInlinedChainForAddress(Address);
445 if (InlinedChain.DIEs.size() == 0) {
446 // If there is no DIE for address (e.g. it is in unavailable .dwo file),
447 // try to at least get file/line info from symbol table.
448 if (Spec.FLIKind != FileLineInfoKind::None) {
450 LineTable = getLineTableForUnit(CU);
452 LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
453 Spec.FLIKind, Frame))
454 InliningInfo.addFrame(Frame);
459 uint32_t CallFile = 0, CallLine = 0, CallColumn = 0;
460 for (uint32_t i = 0, n = InlinedChain.DIEs.size(); i != n; i++) {
461 const DWARFDebugInfoEntryMinimal &FunctionDIE = InlinedChain.DIEs[i];
463 // Get function name if necessary.
464 if (const char *Name =
465 FunctionDIE.getSubroutineName(InlinedChain.U, Spec.FNKind))
466 Frame.FunctionName = Name;
467 if (Spec.FLIKind != FileLineInfoKind::None) {
469 // For the topmost frame, initialize the line table of this
470 // compile unit and fetch file/line info from it.
471 LineTable = getLineTableForUnit(CU);
472 // For the topmost routine, get file/line info from line table.
474 LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
475 Spec.FLIKind, Frame);
477 // Otherwise, use call file, call line and call column from
478 // previous DIE in inlined chain.
480 LineTable->getFileNameByIndex(CallFile, CU->getCompilationDir(),
481 Spec.FLIKind, Frame.FileName);
482 Frame.Line = CallLine;
483 Frame.Column = CallColumn;
485 // Get call file/line/column of a current DIE.
487 FunctionDIE.getCallerFrame(InlinedChain.U, CallFile, CallLine,
491 InliningInfo.addFrame(Frame);
496 static bool consumeCompressedDebugSectionHeader(StringRef &data,
497 uint64_t &OriginalSize) {
498 // Consume "ZLIB" prefix.
499 if (!data.startswith("ZLIB"))
501 data = data.substr(4);
502 // Consume uncompressed section size (big-endian 8 bytes).
503 DataExtractor extractor(data, false, 8);
505 OriginalSize = extractor.getU64(&Offset);
508 data = data.substr(Offset);
512 DWARFContextInMemory::DWARFContextInMemory(const object::ObjectFile &Obj)
513 : IsLittleEndian(Obj.isLittleEndian()),
514 AddressSize(Obj.getBytesInAddress()) {
515 for (const SectionRef &Section : Obj.sections()) {
517 Section.getName(name);
518 // Skip BSS and Virtual sections, they aren't interesting.
519 bool IsBSS = Section.isBSS();
522 bool IsVirtual = Section.isVirtual();
526 Section.getContents(data);
528 name = name.substr(name.find_first_not_of("._")); // Skip . and _ prefixes.
530 // Check if debug info section is compressed with zlib.
531 if (name.startswith("zdebug_")) {
532 uint64_t OriginalSize;
533 if (!zlib::isAvailable() ||
534 !consumeCompressedDebugSectionHeader(data, OriginalSize))
536 UncompressedSections.resize(UncompressedSections.size() + 1);
537 if (zlib::uncompress(data, UncompressedSections.back(), OriginalSize) !=
539 UncompressedSections.pop_back();
542 // Make data point to uncompressed section contents and save its contents.
543 name = name.substr(1);
544 data = UncompressedSections.back();
547 StringRef *SectionData =
548 StringSwitch<StringRef *>(name)
549 .Case("debug_info", &InfoSection.Data)
550 .Case("debug_abbrev", &AbbrevSection)
551 .Case("debug_loc", &LocSection.Data)
552 .Case("debug_line", &LineSection.Data)
553 .Case("debug_aranges", &ARangeSection)
554 .Case("debug_frame", &DebugFrameSection)
555 .Case("debug_str", &StringSection)
556 .Case("debug_ranges", &RangeSection)
557 .Case("debug_pubnames", &PubNamesSection)
558 .Case("debug_pubtypes", &PubTypesSection)
559 .Case("debug_gnu_pubnames", &GnuPubNamesSection)
560 .Case("debug_gnu_pubtypes", &GnuPubTypesSection)
561 .Case("debug_info.dwo", &InfoDWOSection.Data)
562 .Case("debug_abbrev.dwo", &AbbrevDWOSection)
563 .Case("debug_loc.dwo", &LocDWOSection.Data)
564 .Case("debug_line.dwo", &LineDWOSection.Data)
565 .Case("debug_str.dwo", &StringDWOSection)
566 .Case("debug_str_offsets.dwo", &StringOffsetDWOSection)
567 .Case("debug_addr", &AddrSection)
568 // Any more debug info sections go here.
572 if (name == "debug_ranges") {
573 // FIXME: Use the other dwo range section when we emit it.
574 RangeDWOSection = data;
576 } else if (name == "debug_types") {
577 // Find debug_types data by section rather than name as there are
578 // multiple, comdat grouped, debug_types sections.
579 TypesSections[Section].Data = data;
580 } else if (name == "debug_types.dwo") {
581 TypesDWOSections[Section].Data = data;
584 section_iterator RelocatedSection = Section.getRelocatedSection();
585 if (RelocatedSection == Obj.section_end())
588 StringRef RelSecName;
589 RelocatedSection->getName(RelSecName);
590 RelSecName = RelSecName.substr(
591 RelSecName.find_first_not_of("._")); // Skip . and _ prefixes.
593 // TODO: Add support for relocations in other sections as needed.
594 // Record relocations for the debug_info and debug_line sections.
595 RelocAddrMap *Map = StringSwitch<RelocAddrMap*>(RelSecName)
596 .Case("debug_info", &InfoSection.Relocs)
597 .Case("debug_loc", &LocSection.Relocs)
598 .Case("debug_info.dwo", &InfoDWOSection.Relocs)
599 .Case("debug_line", &LineSection.Relocs)
602 // Find debug_types relocs by section rather than name as there are
603 // multiple, comdat grouped, debug_types sections.
604 if (RelSecName == "debug_types")
605 Map = &TypesSections[*RelocatedSection].Relocs;
606 else if (RelSecName == "debug_types.dwo")
607 Map = &TypesDWOSections[*RelocatedSection].Relocs;
612 if (Section.relocation_begin() != Section.relocation_end()) {
613 uint64_t SectionSize = RelocatedSection->getSize();
614 for (const RelocationRef &Reloc : Section.relocations()) {
616 Reloc.getOffset(Address);
619 uint64_t SymAddr = 0;
620 object::symbol_iterator Sym = Reloc.getSymbol();
621 if (Sym != Obj.symbol_end())
622 Sym->getAddress(SymAddr);
624 object::RelocVisitor V(Obj);
625 object::RelocToApply R(V.visit(Type, Reloc, SymAddr));
627 SmallString<32> Name;
628 std::error_code ec(Reloc.getTypeName(Name));
630 errs() << "Aaaaaa! Nameless relocation! Aaaaaa!\n";
632 errs() << "error: failed to compute relocation: "
637 if (Address + R.Width > SectionSize) {
638 errs() << "error: " << R.Width << "-byte relocation starting "
639 << Address << " bytes into section " << name << " which is "
640 << SectionSize << " bytes long.\n";
644 errs() << "error: can't handle a relocation of more than 8 bytes at "
648 DEBUG(dbgs() << "Writing " << format("%p", R.Value)
649 << " at " << format("%p", Address)
650 << " with width " << format("%d", R.Width)
652 Map->insert(std::make_pair(Address, std::make_pair(R.Width, R.Value)));
658 void DWARFContextInMemory::anchor() { }