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 "llvm/ADT/SmallString.h"
12 #include "llvm/ADT/StringSwitch.h"
13 #include "llvm/ADT/STLExtras.h"
14 #include "llvm/Support/Compression.h"
15 #include "llvm/Support/Dwarf.h"
16 #include "llvm/Support/Format.h"
17 #include "llvm/Support/Path.h"
18 #include "llvm/Support/raw_ostream.h"
21 using namespace dwarf;
22 using namespace object;
24 typedef DWARFDebugLine::LineTable DWARFLineTable;
26 DWARFContext::~DWARFContext() {
27 DeleteContainerPointers(CUs);
28 DeleteContainerPointers(DWOCUs);
31 void DWARFContext::dump(raw_ostream &OS, DIDumpType DumpType) {
32 if (DumpType == DIDT_All || DumpType == DIDT_Abbrev) {
33 OS << ".debug_abbrev contents:\n";
34 getDebugAbbrev()->dump(OS);
37 if (DumpType == DIDT_All || DumpType == DIDT_Info) {
38 OS << "\n.debug_info contents:\n";
39 for (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i)
40 getCompileUnitAtIndex(i)->dump(OS);
43 if (DumpType == DIDT_All || DumpType == DIDT_Loc) {
44 OS << ".debug_loc contents:\n";
45 getDebugLoc()->dump(OS);
48 if (DumpType == DIDT_All || DumpType == DIDT_Frames) {
49 OS << "\n.debug_frame contents:\n";
50 getDebugFrame()->dump(OS);
54 if (DumpType == DIDT_All || DumpType == DIDT_Aranges) {
55 OS << "\n.debug_aranges contents:\n";
56 DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0);
57 DWARFDebugArangeSet set;
58 while (set.extract(arangesData, &offset))
62 uint8_t savedAddressByteSize = 0;
63 if (DumpType == DIDT_All || DumpType == DIDT_Line) {
64 OS << "\n.debug_line contents:\n";
65 for (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i) {
66 DWARFCompileUnit *cu = getCompileUnitAtIndex(i);
67 savedAddressByteSize = cu->getAddressByteSize();
69 cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list,
71 if (stmtOffset != -1U) {
72 DataExtractor lineData(getLineSection(), isLittleEndian(),
73 savedAddressByteSize);
74 DWARFDebugLine::DumpingState state(OS);
75 DWARFDebugLine::parseStatementTable(lineData, &lineRelocMap(), &stmtOffset, state);
80 if (DumpType == DIDT_All || DumpType == DIDT_Str) {
81 OS << "\n.debug_str contents:\n";
82 DataExtractor strData(getStringSection(), isLittleEndian(), 0);
84 uint32_t strOffset = 0;
85 while (const char *s = strData.getCStr(&offset)) {
86 OS << format("0x%8.8x: \"%s\"\n", strOffset, s);
91 if (DumpType == DIDT_All || DumpType == DIDT_Ranges) {
92 OS << "\n.debug_ranges contents:\n";
93 // In fact, different compile units may have different address byte
94 // sizes, but for simplicity we just use the address byte size of the last
95 // compile unit (there is no easy and fast way to associate address range
96 // list and the compile unit it describes).
97 DataExtractor rangesData(getRangeSection(), isLittleEndian(),
98 savedAddressByteSize);
100 DWARFDebugRangeList rangeList;
101 while (rangeList.extract(rangesData, &offset))
105 if (DumpType == DIDT_All || DumpType == DIDT_Pubnames) {
106 OS << "\n.debug_pubnames contents:\n";
107 DataExtractor pubNames(getPubNamesSection(), isLittleEndian(), 0);
109 OS << "Length: " << pubNames.getU32(&offset) << "\n";
110 OS << "Version: " << pubNames.getU16(&offset) << "\n";
111 OS << "Offset in .debug_info: " << pubNames.getU32(&offset) << "\n";
112 OS << "Size: " << pubNames.getU32(&offset) << "\n";
113 OS << "\n Offset Name\n";
114 while (offset < getPubNamesSection().size()) {
115 uint32_t n = pubNames.getU32(&offset);
118 OS << format("%8x ", n);
119 OS << pubNames.getCStr(&offset) << "\n";
123 if (DumpType == DIDT_All || DumpType == DIDT_AbbrevDwo) {
124 const DWARFDebugAbbrev *D = getDebugAbbrevDWO();
126 OS << "\n.debug_abbrev.dwo contents:\n";
127 getDebugAbbrevDWO()->dump(OS);
131 if (DumpType == DIDT_All || DumpType == DIDT_InfoDwo)
132 if (getNumDWOCompileUnits()) {
133 OS << "\n.debug_info.dwo contents:\n";
134 for (unsigned i = 0, e = getNumDWOCompileUnits(); i != e; ++i)
135 getDWOCompileUnitAtIndex(i)->dump(OS);
138 if (DumpType == DIDT_All || DumpType == DIDT_StrDwo)
139 if (!getStringDWOSection().empty()) {
140 OS << "\n.debug_str.dwo contents:\n";
141 DataExtractor strDWOData(getStringDWOSection(), isLittleEndian(), 0);
143 uint32_t strDWOOffset = 0;
144 while (const char *s = strDWOData.getCStr(&offset)) {
145 OS << format("0x%8.8x: \"%s\"\n", strDWOOffset, s);
146 strDWOOffset = offset;
150 if (DumpType == DIDT_All || DumpType == DIDT_StrOffsetsDwo)
151 if (!getStringOffsetDWOSection().empty()) {
152 OS << "\n.debug_str_offsets.dwo contents:\n";
153 DataExtractor strOffsetExt(getStringOffsetDWOSection(), isLittleEndian(), 0);
155 uint64_t size = getStringOffsetDWOSection().size();
156 while (offset < size) {
157 OS << format("0x%8.8x: ", offset);
158 OS << format("%8.8x\n", strOffsetExt.getU32(&offset));
163 const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
167 DataExtractor abbrData(getAbbrevSection(), isLittleEndian(), 0);
169 Abbrev.reset(new DWARFDebugAbbrev());
170 Abbrev->parse(abbrData);
174 const DWARFDebugAbbrev *DWARFContext::getDebugAbbrevDWO() {
176 return AbbrevDWO.get();
178 DataExtractor abbrData(getAbbrevDWOSection(), isLittleEndian(), 0);
179 AbbrevDWO.reset(new DWARFDebugAbbrev());
180 AbbrevDWO->parse(abbrData);
181 return AbbrevDWO.get();
184 const DWARFDebugLoc *DWARFContext::getDebugLoc() {
188 DataExtractor LocData(getLocSection(), isLittleEndian(), 0);
189 Loc.reset(new DWARFDebugLoc(locRelocMap()));
190 // assume all compile units have the same address byte size
191 if (getNumCompileUnits())
192 Loc->parse(LocData, getCompileUnitAtIndex(0)->getAddressByteSize());
196 const DWARFDebugAranges *DWARFContext::getDebugAranges() {
198 return Aranges.get();
200 DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0);
202 Aranges.reset(new DWARFDebugAranges());
203 Aranges->extract(arangesData);
204 // Generate aranges from DIEs: even if .debug_aranges section is present,
205 // it may describe only a small subset of compilation units, so we need to
206 // manually build aranges for the rest of them.
207 Aranges->generate(this);
208 return Aranges.get();
211 const DWARFDebugFrame *DWARFContext::getDebugFrame() {
213 return DebugFrame.get();
215 // There's a "bug" in the DWARFv3 standard with respect to the target address
216 // size within debug frame sections. While DWARF is supposed to be independent
217 // of its container, FDEs have fields with size being "target address size",
218 // which isn't specified in DWARF in general. It's only specified for CUs, but
219 // .eh_frame can appear without a .debug_info section. Follow the example of
220 // other tools (libdwarf) and extract this from the container (ObjectFile
221 // provides this information). This problem is fixed in DWARFv4
222 // See this dwarf-discuss discussion for more details:
223 // http://lists.dwarfstd.org/htdig.cgi/dwarf-discuss-dwarfstd.org/2011-December/001173.html
224 DataExtractor debugFrameData(getDebugFrameSection(), isLittleEndian(),
226 DebugFrame.reset(new DWARFDebugFrame());
227 DebugFrame->parse(debugFrameData);
228 return DebugFrame.get();
231 const DWARFLineTable *
232 DWARFContext::getLineTableForCompileUnit(DWARFCompileUnit *cu) {
234 Line.reset(new DWARFDebugLine(&lineRelocMap()));
236 unsigned stmtOffset =
237 cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list,
239 if (stmtOffset == -1U)
240 return 0; // No line table for this compile unit.
242 // See if the line table is cached.
243 if (const DWARFLineTable *lt = Line->getLineTable(stmtOffset))
246 // We have to parse it first.
247 DataExtractor lineData(getLineSection(), isLittleEndian(),
248 cu->getAddressByteSize());
249 return Line->getOrParseLineTable(lineData, stmtOffset);
252 void DWARFContext::parseCompileUnits() {
254 const DataExtractor &DIData = DataExtractor(getInfoSection(),
255 isLittleEndian(), 0);
256 while (DIData.isValidOffset(offset)) {
257 OwningPtr<DWARFCompileUnit> CU(new DWARFCompileUnit(
258 getDebugAbbrev(), getInfoSection(), getAbbrevSection(),
259 getRangeSection(), getStringSection(), StringRef(), getAddrSection(),
260 &infoRelocMap(), isLittleEndian()));
261 if (!CU->extract(DIData, &offset)) {
264 CUs.push_back(CU.take());
265 offset = CUs.back()->getNextCompileUnitOffset();
269 void DWARFContext::parseDWOCompileUnits() {
271 const DataExtractor &DIData = DataExtractor(getInfoDWOSection(),
272 isLittleEndian(), 0);
273 while (DIData.isValidOffset(offset)) {
274 OwningPtr<DWARFCompileUnit> DWOCU(new DWARFCompileUnit(
275 getDebugAbbrevDWO(), getInfoDWOSection(), getAbbrevDWOSection(),
276 getRangeDWOSection(), getStringDWOSection(),
277 getStringOffsetDWOSection(), getAddrSection(), &infoDWORelocMap(),
279 if (!DWOCU->extract(DIData, &offset)) {
282 DWOCUs.push_back(DWOCU.take());
283 offset = DWOCUs.back()->getNextCompileUnitOffset();
288 struct OffsetComparator {
289 bool operator()(const DWARFCompileUnit *LHS,
290 const DWARFCompileUnit *RHS) const {
291 return LHS->getOffset() < RHS->getOffset();
293 bool operator()(const DWARFCompileUnit *LHS, uint32_t RHS) const {
294 return LHS->getOffset() < RHS;
296 bool operator()(uint32_t LHS, const DWARFCompileUnit *RHS) const {
297 return LHS < RHS->getOffset();
302 DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint32_t Offset) {
306 DWARFCompileUnit **CU =
307 std::lower_bound(CUs.begin(), CUs.end(), Offset, OffsetComparator());
308 if (CU != CUs.end()) {
314 DWARFCompileUnit *DWARFContext::getCompileUnitForAddress(uint64_t Address) {
315 // First, get the offset of the compile unit.
316 uint32_t CUOffset = getDebugAranges()->findAddress(Address);
317 // Retrieve the compile unit.
318 return getCompileUnitForOffset(CUOffset);
321 static bool getFileNameForCompileUnit(DWARFCompileUnit *CU,
322 const DWARFLineTable *LineTable,
324 bool NeedsAbsoluteFilePath,
325 std::string &FileName) {
328 !LineTable->getFileNameByIndex(FileIndex, NeedsAbsoluteFilePath,
331 if (NeedsAbsoluteFilePath && sys::path::is_relative(FileName)) {
332 // We may still need to append compilation directory of compile unit.
333 SmallString<16> AbsolutePath;
334 if (const char *CompilationDir = CU->getCompilationDir()) {
335 sys::path::append(AbsolutePath, CompilationDir);
337 sys::path::append(AbsolutePath, FileName);
338 FileName = AbsolutePath.str();
343 static bool getFileLineInfoForCompileUnit(DWARFCompileUnit *CU,
344 const DWARFLineTable *LineTable,
346 bool NeedsAbsoluteFilePath,
347 std::string &FileName,
348 uint32_t &Line, uint32_t &Column) {
349 if (CU == 0 || LineTable == 0)
351 // Get the index of row we're looking for in the line table.
352 uint32_t RowIndex = LineTable->lookupAddress(Address);
355 // Take file number and line/column from the row.
356 const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
357 if (!getFileNameForCompileUnit(CU, LineTable, Row.File,
358 NeedsAbsoluteFilePath, FileName))
365 DILineInfo DWARFContext::getLineInfoForAddress(uint64_t Address,
366 DILineInfoSpecifier Specifier) {
367 DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
370 std::string FileName = "<invalid>";
371 std::string FunctionName = "<invalid>";
374 if (Specifier.needs(DILineInfoSpecifier::FunctionName)) {
375 // The address may correspond to instruction in some inlined function,
376 // so we have to build the chain of inlined functions and take the
377 // name of the topmost function in it.
378 const DWARFDebugInfoEntryInlinedChain &InlinedChain =
379 CU->getInlinedChainForAddress(Address);
380 if (InlinedChain.DIEs.size() > 0) {
381 const DWARFDebugInfoEntryMinimal &TopFunctionDIE = InlinedChain.DIEs[0];
382 if (const char *Name = TopFunctionDIE.getSubroutineName(InlinedChain.CU))
386 if (Specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
387 const DWARFLineTable *LineTable = getLineTableForCompileUnit(CU);
388 const bool NeedsAbsoluteFilePath =
389 Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath);
390 getFileLineInfoForCompileUnit(CU, LineTable, Address,
391 NeedsAbsoluteFilePath,
392 FileName, Line, Column);
394 return DILineInfo(StringRef(FileName), StringRef(FunctionName),
398 DILineInfoTable DWARFContext::getLineInfoForAddressRange(uint64_t Address,
400 DILineInfoSpecifier Specifier) {
401 DILineInfoTable Lines;
402 DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
406 std::string FunctionName = "<invalid>";
407 if (Specifier.needs(DILineInfoSpecifier::FunctionName)) {
408 // The address may correspond to instruction in some inlined function,
409 // so we have to build the chain of inlined functions and take the
410 // name of the topmost function in it.
411 const DWARFDebugInfoEntryInlinedChain &InlinedChain =
412 CU->getInlinedChainForAddress(Address);
413 if (InlinedChain.DIEs.size() > 0) {
414 const DWARFDebugInfoEntryMinimal &TopFunctionDIE = InlinedChain.DIEs[0];
415 if (const char *Name = TopFunctionDIE.getSubroutineName(InlinedChain.CU))
420 StringRef FuncNameRef = StringRef(FunctionName);
422 // If the Specifier says we don't need FileLineInfo, just
423 // return the top-most function at the starting address.
424 if (!Specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
425 Lines.push_back(std::make_pair(Address,
426 DILineInfo(StringRef("<invalid>"),
427 FuncNameRef, 0, 0)));
431 const DWARFLineTable *LineTable = getLineTableForCompileUnit(CU);
432 const bool NeedsAbsoluteFilePath =
433 Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath);
435 // Get the index of row we're looking for in the line table.
436 std::vector<uint32_t> RowVector;
437 if (!LineTable->lookupAddressRange(Address, Size, RowVector))
440 uint32_t NumRows = RowVector.size();
441 for (uint32_t i = 0; i < NumRows; ++i) {
442 uint32_t RowIndex = RowVector[i];
443 // Take file number and line/column from the row.
444 const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
445 std::string FileName = "<invalid>";
446 getFileNameForCompileUnit(CU, LineTable, Row.File,
447 NeedsAbsoluteFilePath, FileName);
448 Lines.push_back(std::make_pair(Row.Address,
449 DILineInfo(StringRef(FileName),
450 FuncNameRef, Row.Line, Row.Column)));
456 DIInliningInfo DWARFContext::getInliningInfoForAddress(uint64_t Address,
457 DILineInfoSpecifier Specifier) {
458 DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
460 return DIInliningInfo();
462 const DWARFDebugInfoEntryInlinedChain &InlinedChain =
463 CU->getInlinedChainForAddress(Address);
464 if (InlinedChain.DIEs.size() == 0)
465 return DIInliningInfo();
467 DIInliningInfo InliningInfo;
468 uint32_t CallFile = 0, CallLine = 0, CallColumn = 0;
469 const DWARFLineTable *LineTable = 0;
470 for (uint32_t i = 0, n = InlinedChain.DIEs.size(); i != n; i++) {
471 const DWARFDebugInfoEntryMinimal &FunctionDIE = InlinedChain.DIEs[i];
472 std::string FileName = "<invalid>";
473 std::string FunctionName = "<invalid>";
476 // Get function name if necessary.
477 if (Specifier.needs(DILineInfoSpecifier::FunctionName)) {
478 if (const char *Name = FunctionDIE.getSubroutineName(InlinedChain.CU))
481 if (Specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
482 const bool NeedsAbsoluteFilePath =
483 Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath);
485 // For the topmost frame, initialize the line table of this
486 // compile unit and fetch file/line info from it.
487 LineTable = getLineTableForCompileUnit(CU);
488 // For the topmost routine, get file/line info from line table.
489 getFileLineInfoForCompileUnit(CU, LineTable, Address,
490 NeedsAbsoluteFilePath,
491 FileName, Line, Column);
493 // Otherwise, use call file, call line and call column from
494 // previous DIE in inlined chain.
495 getFileNameForCompileUnit(CU, LineTable, CallFile,
496 NeedsAbsoluteFilePath, FileName);
500 // Get call file/line/column of a current DIE.
502 FunctionDIE.getCallerFrame(InlinedChain.CU, CallFile, CallLine,
506 DILineInfo Frame(StringRef(FileName), StringRef(FunctionName),
508 InliningInfo.addFrame(Frame);
513 static bool consumeCompressedDebugSectionHeader(StringRef &data,
514 uint64_t &OriginalSize) {
515 // Consume "ZLIB" prefix.
516 if (!data.startswith("ZLIB"))
518 data = data.substr(4);
519 // Consume uncompressed section size (big-endian 8 bytes).
520 DataExtractor extractor(data, false, 8);
522 OriginalSize = extractor.getU64(&Offset);
525 data = data.substr(Offset);
529 DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
530 IsLittleEndian(Obj->isLittleEndian()),
531 AddressSize(Obj->getBytesInAddress()) {
533 for (object::section_iterator i = Obj->begin_sections(),
534 e = Obj->end_sections();
535 i != e; i.increment(ec)) {
539 i->getContents(data);
541 name = name.substr(name.find_first_not_of("._")); // Skip . and _ prefixes.
543 // Check if debug info section is compressed with zlib.
544 if (name.startswith("zdebug_")) {
545 uint64_t OriginalSize;
546 if (!zlib::isAvailable() ||
547 !consumeCompressedDebugSectionHeader(data, OriginalSize))
549 OwningPtr<MemoryBuffer> UncompressedSection;
550 if (zlib::uncompress(data, UncompressedSection, OriginalSize) !=
553 // Make data point to uncompressed section contents and save its contents.
554 name = name.substr(1);
555 data = UncompressedSection->getBuffer();
556 UncompressedSections.push_back(UncompressedSection.take());
559 StringRef *Section = StringSwitch<StringRef*>(name)
560 .Case("debug_info", &InfoSection)
561 .Case("debug_abbrev", &AbbrevSection)
562 .Case("debug_loc", &LocSection)
563 .Case("debug_line", &LineSection)
564 .Case("debug_aranges", &ARangeSection)
565 .Case("debug_frame", &DebugFrameSection)
566 .Case("debug_str", &StringSection)
567 .Case("debug_ranges", &RangeSection)
568 .Case("debug_pubnames", &PubNamesSection)
569 .Case("debug_info.dwo", &InfoDWOSection)
570 .Case("debug_abbrev.dwo", &AbbrevDWOSection)
571 .Case("debug_str.dwo", &StringDWOSection)
572 .Case("debug_str_offsets.dwo", &StringOffsetDWOSection)
573 .Case("debug_addr", &AddrSection)
574 // Any more debug info sections go here.
578 if (name == "debug_ranges") {
579 // FIXME: Use the other dwo range section when we emit it.
580 RangeDWOSection = data;
584 section_iterator RelocatedSection = i->getRelocatedSection();
585 if (RelocatedSection == Obj->end_sections())
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", &InfoRelocMap)
597 .Case("debug_loc", &LocRelocMap)
598 .Case("debug_info.dwo", &InfoDWORelocMap)
599 .Case("debug_line", &LineRelocMap)
604 if (i->begin_relocations() != i->end_relocations()) {
605 uint64_t SectionSize;
606 RelocatedSection->getSize(SectionSize);
607 for (object::relocation_iterator reloc_i = i->begin_relocations(),
608 reloc_e = i->end_relocations();
609 reloc_i != reloc_e; reloc_i.increment(ec)) {
611 reloc_i->getOffset(Address);
613 reloc_i->getType(Type);
614 uint64_t SymAddr = 0;
615 // ELF relocations may need the symbol address
617 object::symbol_iterator Sym = reloc_i->getSymbol();
618 Sym->getAddress(SymAddr);
621 object::RelocVisitor V(Obj->getFileFormatName());
622 // The section address is always 0 for debug sections.
623 object::RelocToApply R(V.visit(Type, *reloc_i, 0, SymAddr));
625 SmallString<32> Name;
626 error_code ec(reloc_i->getTypeName(Name));
628 errs() << "Aaaaaa! Nameless relocation! Aaaaaa!\n";
630 errs() << "error: failed to compute relocation: "
635 if (Address + R.Width > SectionSize) {
636 errs() << "error: " << R.Width << "-byte relocation starting "
637 << Address << " bytes into section " << name << " which is "
638 << SectionSize << " bytes long.\n";
642 errs() << "error: can't handle a relocation of more than 8 bytes at "
646 DEBUG(dbgs() << "Writing " << format("%p", R.Value)
647 << " at " << format("%p", Address)
648 << " with width " << format("%d", R.Width)
650 Map->insert(std::make_pair(Address, std::make_pair(R.Width, R.Value)));
656 DWARFContextInMemory::~DWARFContextInMemory() {
657 DeleteContainerPointers(UncompressedSections);
660 void DWARFContextInMemory::anchor() { }