1 //===-- llvm/CodeGen/DwarfDebug.cpp - Dwarf Debug Framework ---------------===//
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 // This file contains support for writing dwarf debug info into asm files.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "dwarfdebug"
15 #include "ByteStreamer.h"
16 #include "DwarfDebug.h"
19 #include "DwarfAccelTable.h"
20 #include "DwarfUnit.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineModuleInfo.h"
27 #include "llvm/IR/Constants.h"
28 #include "llvm/IR/DIBuilder.h"
29 #include "llvm/IR/DataLayout.h"
30 #include "llvm/IR/DebugInfo.h"
31 #include "llvm/IR/Instructions.h"
32 #include "llvm/IR/Module.h"
33 #include "llvm/IR/ValueHandle.h"
34 #include "llvm/MC/MCAsmInfo.h"
35 #include "llvm/MC/MCSection.h"
36 #include "llvm/MC/MCStreamer.h"
37 #include "llvm/MC/MCSymbol.h"
38 #include "llvm/Support/CommandLine.h"
39 #include "llvm/Support/Debug.h"
40 #include "llvm/Support/Dwarf.h"
41 #include "llvm/Support/ErrorHandling.h"
42 #include "llvm/Support/FormattedStream.h"
43 #include "llvm/Support/LEB128.h"
44 #include "llvm/Support/MD5.h"
45 #include "llvm/Support/Path.h"
46 #include "llvm/Support/Timer.h"
47 #include "llvm/Target/TargetFrameLowering.h"
48 #include "llvm/Target/TargetLoweringObjectFile.h"
49 #include "llvm/Target/TargetMachine.h"
50 #include "llvm/Target/TargetOptions.h"
51 #include "llvm/Target/TargetRegisterInfo.h"
55 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
56 cl::desc("Disable debug info printing"));
58 static cl::opt<bool> UnknownLocations(
59 "use-unknown-locations", cl::Hidden,
60 cl::desc("Make an absence of debug location information explicit."),
64 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
65 cl::desc("Generate GNU-style pubnames and pubtypes"),
68 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
70 cl::desc("Generate dwarf aranges"),
74 enum DefaultOnOff { Default, Enable, Disable };
77 static cl::opt<DefaultOnOff>
78 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
79 cl::desc("Output prototype dwarf accelerator tables."),
80 cl::values(clEnumVal(Default, "Default for platform"),
81 clEnumVal(Enable, "Enabled"),
82 clEnumVal(Disable, "Disabled"), clEnumValEnd),
85 static cl::opt<DefaultOnOff>
86 SplitDwarf("split-dwarf", cl::Hidden,
87 cl::desc("Output DWARF5 split debug info."),
88 cl::values(clEnumVal(Default, "Default for platform"),
89 clEnumVal(Enable, "Enabled"),
90 clEnumVal(Disable, "Disabled"), clEnumValEnd),
93 static cl::opt<DefaultOnOff>
94 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
95 cl::desc("Generate DWARF pubnames and pubtypes sections"),
96 cl::values(clEnumVal(Default, "Default for platform"),
97 clEnumVal(Enable, "Enabled"),
98 clEnumVal(Disable, "Disabled"), clEnumValEnd),
101 static cl::opt<unsigned>
102 DwarfVersionNumber("dwarf-version", cl::Hidden,
103 cl::desc("Generate DWARF for dwarf version."), cl::init(0));
105 static const char *const DWARFGroupName = "DWARF Emission";
106 static const char *const DbgTimerName = "DWARF Debug Writer";
108 //===----------------------------------------------------------------------===//
112 /// resolve - Look in the DwarfDebug map for the MDNode that
113 /// corresponds to the reference.
114 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
115 return DD->resolve(Ref);
118 bool DbgVariable::isBlockByrefVariable() const {
119 assert(Var.isVariable() && "Invalid complex DbgVariable!");
120 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
124 DIType DbgVariable::getType() const {
125 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
126 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
127 // addresses instead.
128 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
129 /* Byref variables, in Blocks, are declared by the programmer as
130 "SomeType VarName;", but the compiler creates a
131 __Block_byref_x_VarName struct, and gives the variable VarName
132 either the struct, or a pointer to the struct, as its type. This
133 is necessary for various behind-the-scenes things the compiler
134 needs to do with by-reference variables in blocks.
136 However, as far as the original *programmer* is concerned, the
137 variable should still have type 'SomeType', as originally declared.
139 The following function dives into the __Block_byref_x_VarName
140 struct to find the original type of the variable. This will be
141 passed back to the code generating the type for the Debug
142 Information Entry for the variable 'VarName'. 'VarName' will then
143 have the original type 'SomeType' in its debug information.
145 The original type 'SomeType' will be the type of the field named
146 'VarName' inside the __Block_byref_x_VarName struct.
148 NOTE: In order for this to not completely fail on the debugger
149 side, the Debug Information Entry for the variable VarName needs to
150 have a DW_AT_location that tells the debugger how to unwind through
151 the pointers and __Block_byref_x_VarName struct to find the actual
152 value of the variable. The function addBlockByrefType does this. */
154 uint16_t tag = Ty.getTag();
156 if (tag == dwarf::DW_TAG_pointer_type)
157 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
159 DIArray Elements = DICompositeType(subType).getTypeArray();
160 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
161 DIDerivedType DT(Elements.getElement(i));
162 if (getName() == DT.getName())
163 return (resolve(DT.getTypeDerivedFrom()));
169 } // end llvm namespace
171 /// Return Dwarf Version by checking module flags.
172 static unsigned getDwarfVersionFromModule(const Module *M) {
173 Value *Val = M->getModuleFlag("Dwarf Version");
175 return dwarf::DWARF_VERSION;
176 return cast<ConstantInt>(Val)->getZExtValue();
179 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
180 : Asm(A), MMI(Asm->MMI), FirstCU(0), PrevLabel(NULL), GlobalRangeCount(0),
181 InfoHolder(A, "info_string", DIEValueAllocator), HasCURanges(false),
182 UsedNonDefaultText(false),
183 SkeletonHolder(A, "skel_string", DIEValueAllocator) {
185 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = 0;
186 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = DwarfLineSectionSym = 0;
187 DwarfAddrSectionSym = 0;
188 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = 0;
189 FunctionBeginSym = FunctionEndSym = 0;
193 // Turn on accelerator tables for Darwin by default, pubnames by
194 // default for non-Darwin, and handle split dwarf.
195 bool IsDarwin = Triple(A->getTargetTriple()).isOSDarwin();
197 if (DwarfAccelTables == Default)
198 HasDwarfAccelTables = IsDarwin;
200 HasDwarfAccelTables = DwarfAccelTables == Enable;
202 if (SplitDwarf == Default)
203 HasSplitDwarf = false;
205 HasSplitDwarf = SplitDwarf == Enable;
207 if (DwarfPubSections == Default)
208 HasDwarfPubSections = !IsDarwin;
210 HasDwarfPubSections = DwarfPubSections == Enable;
212 DwarfVersion = DwarfVersionNumber
214 : getDwarfVersionFromModule(MMI->getModule());
217 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
222 // Switch to the specified MCSection and emit an assembler
223 // temporary label to it if SymbolStem is specified.
224 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
225 const char *SymbolStem = 0) {
226 Asm->OutStreamer.SwitchSection(Section);
230 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
231 Asm->OutStreamer.EmitLabel(TmpSym);
235 DwarfFile::~DwarfFile() {
236 for (DwarfUnit *DU : CUs)
240 MCSymbol *DwarfFile::getStringPoolSym() {
241 return Asm->GetTempSymbol(StringPref);
244 MCSymbol *DwarfFile::getStringPoolEntry(StringRef Str) {
245 std::pair<MCSymbol *, unsigned> &Entry =
246 StringPool.GetOrCreateValue(Str).getValue();
250 Entry.second = NextStringPoolNumber++;
251 return Entry.first = Asm->GetTempSymbol(StringPref, Entry.second);
254 unsigned DwarfFile::getStringPoolIndex(StringRef Str) {
255 std::pair<MCSymbol *, unsigned> &Entry =
256 StringPool.GetOrCreateValue(Str).getValue();
260 Entry.second = NextStringPoolNumber++;
261 Entry.first = Asm->GetTempSymbol(StringPref, Entry.second);
265 unsigned DwarfFile::getAddrPoolIndex(const MCSymbol *Sym, bool TLS) {
266 std::pair<AddrPool::iterator, bool> P = AddressPool.insert(
267 std::make_pair(Sym, AddressPoolEntry(NextAddrPoolNumber, TLS)));
269 ++NextAddrPoolNumber;
270 return P.first->second.Number;
273 // Define a unique number for the abbreviation.
275 void DwarfFile::assignAbbrevNumber(DIEAbbrev &Abbrev) {
276 // Check the set for priors.
277 DIEAbbrev *InSet = AbbreviationsSet.GetOrInsertNode(&Abbrev);
279 // If it's newly added.
280 if (InSet == &Abbrev) {
281 // Add to abbreviation list.
282 Abbreviations.push_back(&Abbrev);
284 // Assign the vector position + 1 as its number.
285 Abbrev.setNumber(Abbreviations.size());
287 // Assign existing abbreviation number.
288 Abbrev.setNumber(InSet->getNumber());
292 static bool isObjCClass(StringRef Name) {
293 return Name.startswith("+") || Name.startswith("-");
296 static bool hasObjCCategory(StringRef Name) {
297 if (!isObjCClass(Name))
300 return Name.find(") ") != StringRef::npos;
303 static void getObjCClassCategory(StringRef In, StringRef &Class,
304 StringRef &Category) {
305 if (!hasObjCCategory(In)) {
306 Class = In.slice(In.find('[') + 1, In.find(' '));
311 Class = In.slice(In.find('[') + 1, In.find('('));
312 Category = In.slice(In.find('[') + 1, In.find(' '));
316 static StringRef getObjCMethodName(StringRef In) {
317 return In.slice(In.find(' ') + 1, In.find(']'));
320 // Helper for sorting sections into a stable output order.
321 static bool SectionSort(const MCSection *A, const MCSection *B) {
322 std::string LA = (A ? A->getLabelBeginName() : "");
323 std::string LB = (B ? B->getLabelBeginName() : "");
327 // Add the various names to the Dwarf accelerator table names.
328 // TODO: Determine whether or not we should add names for programs
329 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
330 // is only slightly different than the lookup of non-standard ObjC names.
331 static void addSubprogramNames(DwarfUnit *TheU, DISubprogram SP, DIE *Die) {
332 if (!SP.isDefinition())
334 TheU->addAccelName(SP.getName(), Die);
336 // If the linkage name is different than the name, go ahead and output
337 // that as well into the name table.
338 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
339 TheU->addAccelName(SP.getLinkageName(), Die);
341 // If this is an Objective-C selector name add it to the ObjC accelerator
343 if (isObjCClass(SP.getName())) {
344 StringRef Class, Category;
345 getObjCClassCategory(SP.getName(), Class, Category);
346 TheU->addAccelObjC(Class, Die);
348 TheU->addAccelObjC(Category, Die);
349 // Also add the base method name to the name table.
350 TheU->addAccelName(getObjCMethodName(SP.getName()), Die);
354 /// isSubprogramContext - Return true if Context is either a subprogram
355 /// or another context nested inside a subprogram.
356 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
359 DIDescriptor D(Context);
360 if (D.isSubprogram())
363 return isSubprogramContext(resolve(DIType(Context).getContext()));
367 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
368 // and DW_AT_high_pc attributes. If there are global variables in this
369 // scope then create and insert DIEs for these variables.
370 DIE *DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit *SPCU,
372 DIE *SPDie = SPCU->getDIE(SP);
374 assert(SPDie && "Unable to find subprogram DIE!");
376 // If we're updating an abstract DIE, then we will be adding the children and
377 // object pointer later on. But what we don't want to do is process the
378 // concrete DIE twice.
379 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
380 // Pick up abstract subprogram DIE.
382 SPCU->createAndAddDIE(dwarf::DW_TAG_subprogram, *SPCU->getUnitDie());
383 SPCU->addDIEEntry(SPDie, dwarf::DW_AT_abstract_origin, AbsSPDIE);
385 DISubprogram SPDecl = SP.getFunctionDeclaration();
386 if (!SPDecl.isSubprogram()) {
387 // There is not any need to generate specification DIE for a function
388 // defined at compile unit level. If a function is defined inside another
389 // function then gdb prefers the definition at top level and but does not
390 // expect specification DIE in parent function. So avoid creating
391 // specification DIE for a function defined inside a function.
392 DIScope SPContext = resolve(SP.getContext());
393 if (SP.isDefinition() && !SPContext.isCompileUnit() &&
394 !SPContext.isFile() && !isSubprogramContext(SPContext)) {
395 SPCU->addFlag(SPDie, dwarf::DW_AT_declaration);
398 DICompositeType SPTy = SP.getType();
399 DIArray Args = SPTy.getTypeArray();
400 uint16_t SPTag = SPTy.getTag();
401 if (SPTag == dwarf::DW_TAG_subroutine_type)
402 SPCU->constructSubprogramArguments(*SPDie, Args);
403 DIE *SPDeclDie = SPDie;
404 SPDie = SPCU->createAndAddDIE(dwarf::DW_TAG_subprogram,
405 *SPCU->getUnitDie());
406 SPCU->addDIEEntry(SPDie, dwarf::DW_AT_specification, SPDeclDie);
411 attachLowHighPC(SPCU, SPDie, FunctionBeginSym, FunctionEndSym);
413 const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
414 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
415 SPCU->addAddress(SPDie, dwarf::DW_AT_frame_base, Location);
417 // Add name to the name table, we do this here because we're guaranteed
418 // to have concrete versions of our DW_TAG_subprogram nodes.
419 addSubprogramNames(SPCU, SP, SPDie);
424 /// Check whether we should create a DIE for the given Scope, return true
425 /// if we don't create a DIE (the corresponding DIE is null).
426 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
427 if (Scope->isAbstractScope())
430 // We don't create a DIE if there is no Range.
431 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
435 if (Ranges.size() > 1)
438 // We don't create a DIE if we have a single Range and the end label
440 SmallVectorImpl<InsnRange>::const_iterator RI = Ranges.begin();
441 MCSymbol *End = getLabelAfterInsn(RI->second);
445 static void addSectionLabel(AsmPrinter *Asm, DwarfUnit *U, DIE *D,
446 dwarf::Attribute A, const MCSymbol *L,
447 const MCSymbol *Sec) {
448 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
449 U->addSectionLabel(D, A, L);
451 U->addSectionDelta(D, A, L, Sec);
454 void DwarfDebug::addScopeRangeList(DwarfCompileUnit *TheCU, DIE *ScopeDIE,
455 const SmallVectorImpl<InsnRange> &Range) {
456 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
457 // emitting it appropriately.
458 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
459 addSectionLabel(Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
460 DwarfDebugRangeSectionSym);
462 RangeSpanList List(RangeSym);
463 for (const InsnRange &R : Range) {
464 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
465 List.addRange(std::move(Span));
468 // Add the range list to the set of ranges to be emitted.
469 TheCU->addRangeList(std::move(List));
472 // Construct new DW_TAG_lexical_block for this scope and attach
473 // DW_AT_low_pc/DW_AT_high_pc labels.
474 DIE *DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit *TheCU,
475 LexicalScope *Scope) {
476 if (isLexicalScopeDIENull(Scope))
479 DIE *ScopeDIE = new DIE(dwarf::DW_TAG_lexical_block);
480 if (Scope->isAbstractScope())
483 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
485 // If we have multiple ranges, emit them into the range section.
486 if (ScopeRanges.size() > 1) {
487 addScopeRangeList(TheCU, ScopeDIE, ScopeRanges);
491 // Construct the address range for this DIE.
492 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
493 MCSymbol *Start = getLabelBeforeInsn(RI->first);
494 MCSymbol *End = getLabelAfterInsn(RI->second);
495 assert(End && "End label should not be null!");
497 assert(Start->isDefined() && "Invalid starting label for an inlined scope!");
498 assert(End->isDefined() && "Invalid end label for an inlined scope!");
500 attachLowHighPC(TheCU, ScopeDIE, Start, End);
505 // This scope represents inlined body of a function. Construct DIE to
506 // represent this concrete inlined copy of the function.
507 DIE *DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit *TheCU,
508 LexicalScope *Scope) {
509 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
510 assert(!ScopeRanges.empty() &&
511 "LexicalScope does not have instruction markers!");
513 if (!Scope->getScopeNode())
515 DIScope DS(Scope->getScopeNode());
516 DISubprogram InlinedSP = getDISubprogram(DS);
517 DIE *OriginDIE = TheCU->getDIE(InlinedSP);
519 DEBUG(dbgs() << "Unable to find original DIE for an inlined subprogram.");
523 DIE *ScopeDIE = new DIE(dwarf::DW_TAG_inlined_subroutine);
524 TheCU->addDIEEntry(ScopeDIE, dwarf::DW_AT_abstract_origin, OriginDIE);
526 // If we have multiple ranges, emit them into the range section.
527 if (ScopeRanges.size() > 1)
528 addScopeRangeList(TheCU, ScopeDIE, ScopeRanges);
530 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
531 MCSymbol *StartLabel = getLabelBeforeInsn(RI->first);
532 MCSymbol *EndLabel = getLabelAfterInsn(RI->second);
534 if (StartLabel == 0 || EndLabel == 0)
535 llvm_unreachable("Unexpected Start and End labels for an inlined scope!");
537 assert(StartLabel->isDefined() &&
538 "Invalid starting label for an inlined scope!");
539 assert(EndLabel->isDefined() && "Invalid end label for an inlined scope!");
541 attachLowHighPC(TheCU, ScopeDIE, StartLabel, EndLabel);
544 InlinedSubprogramDIEs.insert(OriginDIE);
546 // Add the call site information to the DIE.
547 DILocation DL(Scope->getInlinedAt());
549 ScopeDIE, dwarf::DW_AT_call_file, None,
550 TheCU->getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
551 TheCU->addUInt(ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
553 // Add name to the name table, we do this here because we're guaranteed
554 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
555 addSubprogramNames(TheCU, InlinedSP, ScopeDIE);
560 DIE *DwarfDebug::createScopeChildrenDIE(DwarfCompileUnit *TheCU,
562 SmallVectorImpl<DIE *> &Children) {
563 DIE *ObjectPointer = NULL;
565 // Collect arguments for current function.
566 if (LScopes.isCurrentFunctionScope(Scope)) {
567 for (DbgVariable *ArgDV : CurrentFnArguments)
570 TheCU->constructVariableDIE(*ArgDV, Scope->isAbstractScope())) {
571 Children.push_back(Arg);
572 if (ArgDV->isObjectPointer())
576 // If this is a variadic function, add an unspecified parameter.
577 DISubprogram SP(Scope->getScopeNode());
578 DIArray FnArgs = SP.getType().getTypeArray();
579 if (FnArgs.getElement(FnArgs.getNumElements() - 1)
580 .isUnspecifiedParameter()) {
581 DIE *Ellipsis = new DIE(dwarf::DW_TAG_unspecified_parameters);
582 Children.push_back(Ellipsis);
586 // Collect lexical scope children first.
587 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
588 if (DIE *Variable = TheCU->constructVariableDIE(*DV,
589 Scope->isAbstractScope())) {
590 Children.push_back(Variable);
591 if (DV->isObjectPointer())
592 ObjectPointer = Variable;
594 for (LexicalScope *LS : Scope->getChildren())
595 if (DIE *Nested = constructScopeDIE(TheCU, LS))
596 Children.push_back(Nested);
597 return ObjectPointer;
600 // Construct a DIE for this scope.
601 DIE *DwarfDebug::constructScopeDIE(DwarfCompileUnit *TheCU,
602 LexicalScope *Scope) {
603 if (!Scope || !Scope->getScopeNode())
606 // Unique scope where applicable.
607 DIScope DS(resolve(DIScope(Scope->getScopeNode()).getRef()));
609 SmallVector<DIE *, 8> Children;
610 DIE *ObjectPointer = NULL;
611 bool ChildrenCreated = false;
613 // We try to create the scope DIE first, then the children DIEs. This will
614 // avoid creating un-used children then removing them later when we find out
615 // the scope DIE is null.
616 DIE *ScopeDIE = NULL;
617 if (Scope->getInlinedAt())
618 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
619 else if (DS.isSubprogram()) {
620 ProcessedSPNodes.insert(DS);
621 if (Scope->isAbstractScope()) {
622 ScopeDIE = TheCU->getDIE(DS);
623 // Note down abstract DIE.
625 AbstractSPDies.insert(std::make_pair(DS, ScopeDIE));
627 ScopeDIE = updateSubprogramScopeDIE(TheCU, DISubprogram(DS));
629 // Early exit when we know the scope DIE is going to be null.
630 if (isLexicalScopeDIENull(Scope))
633 // We create children here when we know the scope DIE is not going to be
634 // null and the children will be added to the scope DIE.
635 ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
636 ChildrenCreated = true;
638 // There is no need to emit empty lexical block DIE.
639 std::pair<ImportedEntityMap::const_iterator,
640 ImportedEntityMap::const_iterator> Range =
642 ScopesWithImportedEntities.begin(),
643 ScopesWithImportedEntities.end(),
644 std::pair<const MDNode *, const MDNode *>(DS, (const MDNode *)0),
646 if (Children.empty() && Range.first == Range.second)
648 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
649 assert(ScopeDIE && "Scope DIE should not be null.");
650 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
652 constructImportedEntityDIE(TheCU, i->second, ScopeDIE);
656 assert(Children.empty() &&
657 "We create children only when the scope DIE is not null.");
660 if (!ChildrenCreated)
661 // We create children when the scope DIE is not null.
662 ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
665 for (DIE *I : Children)
666 ScopeDIE->addChild(I);
668 if (DS.isSubprogram() && ObjectPointer != NULL)
669 TheCU->addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, ObjectPointer);
674 void DwarfDebug::addGnuPubAttributes(DwarfUnit *U, DIE *D) const {
675 if (!GenerateGnuPubSections)
678 U->addFlag(D, dwarf::DW_AT_GNU_pubnames);
681 // Create new DwarfCompileUnit for the given metadata node with tag
682 // DW_TAG_compile_unit.
683 DwarfCompileUnit *DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
684 StringRef FN = DIUnit.getFilename();
685 CompilationDir = DIUnit.getDirectory();
687 DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
688 DwarfCompileUnit *NewCU = new DwarfCompileUnit(
689 InfoHolder.getUnits().size(), Die, DIUnit, Asm, this, &InfoHolder);
690 InfoHolder.addUnit(NewCU);
691 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
692 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
693 NewCU->getUniqueID(), CompilationDir);
695 NewCU->addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
696 NewCU->addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
697 DIUnit.getLanguage());
698 NewCU->addString(Die, dwarf::DW_AT_name, FN);
700 if (!useSplitDwarf()) {
701 NewCU->initStmtList(DwarfLineSectionSym);
703 // If we're using split dwarf the compilation dir is going to be in the
704 // skeleton CU and so we don't need to duplicate it here.
705 if (!CompilationDir.empty())
706 NewCU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
708 addGnuPubAttributes(NewCU, Die);
711 if (DIUnit.isOptimized())
712 NewCU->addFlag(Die, dwarf::DW_AT_APPLE_optimized);
714 StringRef Flags = DIUnit.getFlags();
716 NewCU->addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
718 if (unsigned RVer = DIUnit.getRunTimeVersion())
719 NewCU->addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
720 dwarf::DW_FORM_data1, RVer);
725 if (useSplitDwarf()) {
726 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
727 DwarfInfoDWOSectionSym);
728 NewCU->setSkeleton(constructSkeletonCU(NewCU));
730 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
731 DwarfInfoSectionSym);
733 CUMap.insert(std::make_pair(DIUnit, NewCU));
734 CUDieMap.insert(std::make_pair(Die, NewCU));
738 // Construct subprogram DIE.
739 void DwarfDebug::constructSubprogramDIE(DwarfCompileUnit *TheCU,
741 // FIXME: We should only call this routine once, however, during LTO if a
742 // program is defined in multiple CUs we could end up calling it out of
743 // beginModule as we walk the CUs.
745 DwarfCompileUnit *&CURef = SPMap[N];
751 if (!SP.isDefinition())
752 // This is a method declaration which will be handled while constructing
756 DIE *SubprogramDie = TheCU->getOrCreateSubprogramDIE(SP);
758 // Expose as a global name.
759 TheCU->addGlobalName(SP.getName(), SubprogramDie, resolve(SP.getContext()));
762 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
764 DIImportedEntity Module(N);
765 assert(Module.Verify());
766 if (DIE *D = TheCU->getOrCreateContextDIE(Module.getContext()))
767 constructImportedEntityDIE(TheCU, Module, D);
770 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
771 const MDNode *N, DIE *Context) {
772 DIImportedEntity Module(N);
773 assert(Module.Verify());
774 return constructImportedEntityDIE(TheCU, Module, Context);
777 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
778 const DIImportedEntity &Module,
780 assert(Module.Verify() &&
781 "Use one of the MDNode * overloads to handle invalid metadata");
782 assert(Context && "Should always have a context for an imported_module");
783 DIE *IMDie = new DIE(Module.getTag());
784 TheCU->insertDIE(Module, IMDie);
786 DIDescriptor Entity = Module.getEntity();
787 if (Entity.isNameSpace())
788 EntityDie = TheCU->getOrCreateNameSpace(DINameSpace(Entity));
789 else if (Entity.isSubprogram())
790 EntityDie = TheCU->getOrCreateSubprogramDIE(DISubprogram(Entity));
791 else if (Entity.isType())
792 EntityDie = TheCU->getOrCreateTypeDIE(DIType(Entity));
794 EntityDie = TheCU->getDIE(Entity);
795 TheCU->addSourceLine(IMDie, Module.getLineNumber(),
796 Module.getContext().getFilename(),
797 Module.getContext().getDirectory());
798 TheCU->addDIEEntry(IMDie, dwarf::DW_AT_import, EntityDie);
799 StringRef Name = Module.getName();
801 TheCU->addString(IMDie, dwarf::DW_AT_name, Name);
802 Context->addChild(IMDie);
805 // Emit all Dwarf sections that should come prior to the content. Create
806 // global DIEs and emit initial debug info sections. This is invoked by
807 // the target AsmPrinter.
808 void DwarfDebug::beginModule() {
809 if (DisableDebugInfoPrinting)
812 const Module *M = MMI->getModule();
814 // If module has named metadata anchors then use them, otherwise scan the
815 // module using debug info finder to collect debug info.
816 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
819 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
821 // Emit initial sections so we can reference labels later.
824 SingleCU = CU_Nodes->getNumOperands() == 1;
826 for (MDNode *N : CU_Nodes->operands()) {
827 DICompileUnit CUNode(N);
828 DwarfCompileUnit *CU = constructDwarfCompileUnit(CUNode);
829 DIArray ImportedEntities = CUNode.getImportedEntities();
830 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
831 ScopesWithImportedEntities.push_back(std::make_pair(
832 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
833 ImportedEntities.getElement(i)));
834 std::sort(ScopesWithImportedEntities.begin(),
835 ScopesWithImportedEntities.end(), less_first());
836 DIArray GVs = CUNode.getGlobalVariables();
837 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
838 CU->createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
839 DIArray SPs = CUNode.getSubprograms();
840 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
841 constructSubprogramDIE(CU, SPs.getElement(i));
842 DIArray EnumTypes = CUNode.getEnumTypes();
843 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
844 CU->getOrCreateTypeDIE(EnumTypes.getElement(i));
845 DIArray RetainedTypes = CUNode.getRetainedTypes();
846 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
847 DIType Ty(RetainedTypes.getElement(i));
848 // The retained types array by design contains pointers to
849 // MDNodes rather than DIRefs. Unique them here.
850 DIType UniqueTy(resolve(Ty.getRef()));
851 CU->getOrCreateTypeDIE(UniqueTy);
853 // Emit imported_modules last so that the relevant context is already
855 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
856 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
859 // Tell MMI that we have debug info.
860 MMI->setDebugInfoAvailability(true);
862 // Prime section data.
863 SectionMap[Asm->getObjFileLowering().getTextSection()];
866 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
867 void DwarfDebug::computeInlinedDIEs() {
868 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
869 for (DIE *ISP : InlinedSubprogramDIEs)
870 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
872 for (const auto &AI : AbstractSPDies) {
873 DIE *ISP = AI.second;
874 if (InlinedSubprogramDIEs.count(ISP))
876 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
880 // Collect info for variables that were optimized out.
881 void DwarfDebug::collectDeadVariables() {
882 const Module *M = MMI->getModule();
884 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
885 for (MDNode *N : CU_Nodes->operands()) {
886 DICompileUnit TheCU(N);
887 DIArray Subprograms = TheCU.getSubprograms();
888 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
889 DISubprogram SP(Subprograms.getElement(i));
890 if (ProcessedSPNodes.count(SP) != 0)
892 if (!SP.isSubprogram())
894 if (!SP.isDefinition())
896 DIArray Variables = SP.getVariables();
897 if (Variables.getNumElements() == 0)
900 // Construct subprogram DIE and add variables DIEs.
901 DwarfCompileUnit *SPCU =
902 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
903 assert(SPCU && "Unable to find Compile Unit!");
904 // FIXME: See the comment in constructSubprogramDIE about duplicate
906 constructSubprogramDIE(SPCU, SP);
907 DIE *SPDIE = SPCU->getDIE(SP);
908 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
909 DIVariable DV(Variables.getElement(vi));
910 if (!DV.isVariable())
912 DbgVariable NewVar(DV, NULL, this);
913 if (DIE *VariableDIE = SPCU->constructVariableDIE(NewVar, false))
914 SPDIE->addChild(VariableDIE);
921 void DwarfDebug::finalizeModuleInfo() {
922 // Collect info for variables that were optimized out.
923 collectDeadVariables();
925 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
926 computeInlinedDIEs();
928 // Handle anything that needs to be done on a per-unit basis after
929 // all other generation.
930 for (DwarfUnit *TheU : getUnits()) {
931 // Emit DW_AT_containing_type attribute to connect types with their
932 // vtable holding type.
933 TheU->constructContainingTypeDIEs();
935 // Add CU specific attributes if we need to add any.
936 if (TheU->getUnitDie()->getTag() == dwarf::DW_TAG_compile_unit) {
937 // If we're splitting the dwarf out now that we've got the entire
938 // CU then add the dwo id to it.
939 DwarfCompileUnit *SkCU =
940 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
941 if (useSplitDwarf()) {
942 // Emit a unique identifier for this CU.
943 uint64_t ID = DIEHash(Asm).computeCUSignature(*TheU->getUnitDie());
944 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
945 dwarf::DW_FORM_data8, ID);
946 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
947 dwarf::DW_FORM_data8, ID);
950 // If we have code split among multiple sections or we've requested
951 // it then emit a DW_AT_ranges attribute on the unit that will remain
952 // in the .o file, otherwise add a DW_AT_low_pc.
953 // FIXME: Also add a high pc if we can.
954 // FIXME: We should use ranges if we have multiple compile units or
955 // allow reordering of code ala .subsections_via_symbols in mach-o.
956 DwarfCompileUnit *U = SkCU ? SkCU : static_cast<DwarfCompileUnit *>(TheU);
957 if (useCURanges() && TheU->getRanges().size()) {
958 addSectionLabel(Asm, U, U->getUnitDie(), dwarf::DW_AT_ranges,
959 Asm->GetTempSymbol("cu_ranges", U->getUniqueID()),
960 DwarfDebugRangeSectionSym);
962 // A DW_AT_low_pc attribute may also be specified in combination with
963 // DW_AT_ranges to specify the default base address for use in location
964 // lists (see Section 2.6.2) and range lists (see Section 2.17.3).
965 U->addUInt(U->getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
968 U->addUInt(U->getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
973 // Compute DIE offsets and sizes.
974 InfoHolder.computeSizeAndOffsets();
976 SkeletonHolder.computeSizeAndOffsets();
979 void DwarfDebug::endSections() {
980 // Filter labels by section.
981 for (const SymbolCU &SCU : ArangeLabels) {
982 if (SCU.Sym->isInSection()) {
983 // Make a note of this symbol and it's section.
984 const MCSection *Section = &SCU.Sym->getSection();
985 if (!Section->getKind().isMetadata())
986 SectionMap[Section].push_back(SCU);
988 // Some symbols (e.g. common/bss on mach-o) can have no section but still
989 // appear in the output. This sucks as we rely on sections to build
990 // arange spans. We can do it without, but it's icky.
991 SectionMap[NULL].push_back(SCU);
995 // Build a list of sections used.
996 std::vector<const MCSection *> Sections;
997 for (const auto &it : SectionMap) {
998 const MCSection *Section = it.first;
999 Sections.push_back(Section);
1002 // Sort the sections into order.
1003 // This is only done to ensure consistent output order across different runs.
1004 std::sort(Sections.begin(), Sections.end(), SectionSort);
1006 // Add terminating symbols for each section.
1007 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1008 const MCSection *Section = Sections[ID];
1009 MCSymbol *Sym = NULL;
1012 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1013 // if we know the section name up-front. For user-created sections, the
1014 // resulting label may not be valid to use as a label. (section names can
1015 // use a greater set of characters on some systems)
1016 Sym = Asm->GetTempSymbol("debug_end", ID);
1017 Asm->OutStreamer.SwitchSection(Section);
1018 Asm->OutStreamer.EmitLabel(Sym);
1021 // Insert a final terminator.
1022 SectionMap[Section].push_back(SymbolCU(NULL, Sym));
1025 // For now only turn on CU ranges if we have -ffunction-sections enabled,
1026 // we've emitted a function into a unique section, or we're using LTO. If
1027 // we're using LTO then we can't know that any particular function in the
1028 // module is correlated to a particular CU and so we need to be conservative.
1029 // At this point all sections should be finalized except for dwarf sections.
1030 HasCURanges = UsedNonDefaultText || (CUMap.size() > 1) ||
1031 TargetMachine::getFunctionSections();
1034 // Emit all Dwarf sections that should come after the content.
1035 void DwarfDebug::endModule() {
1042 // End any existing sections.
1043 // TODO: Does this need to happen?
1046 // Finalize the debug info for the module.
1047 finalizeModuleInfo();
1051 // Emit all the DIEs into a debug info section.
1054 // Corresponding abbreviations into a abbrev section.
1055 emitAbbreviations();
1057 // Emit info into a debug loc section.
1060 // Emit info into a debug aranges section.
1061 if (GenerateARangeSection)
1064 // Emit info into a debug ranges section.
1067 if (useSplitDwarf()) {
1070 emitDebugAbbrevDWO();
1072 // Emit DWO addresses.
1073 InfoHolder.emitAddresses(Asm->getObjFileLowering().getDwarfAddrSection());
1076 // Emit info into the dwarf accelerator table sections.
1077 if (useDwarfAccelTables()) {
1080 emitAccelNamespaces();
1084 // Emit the pubnames and pubtypes sections if requested.
1085 if (HasDwarfPubSections) {
1086 emitDebugPubNames(GenerateGnuPubSections);
1087 emitDebugPubTypes(GenerateGnuPubSections);
1093 // Reset these for the next Module if we have one.
1097 // Find abstract variable, if any, associated with Var.
1098 DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
1099 DebugLoc ScopeLoc) {
1100 LLVMContext &Ctx = DV->getContext();
1101 // More then one inlined variable corresponds to one abstract variable.
1102 DIVariable Var = cleanseInlinedVariable(DV, Ctx);
1103 DbgVariable *AbsDbgVariable = AbstractVariables.lookup(Var);
1105 return AbsDbgVariable;
1107 LexicalScope *Scope = LScopes.findAbstractScope(ScopeLoc.getScope(Ctx));
1111 AbsDbgVariable = new DbgVariable(Var, NULL, this);
1112 addScopeVariable(Scope, AbsDbgVariable);
1113 AbstractVariables[Var] = AbsDbgVariable;
1114 return AbsDbgVariable;
1117 // If Var is a current function argument then add it to CurrentFnArguments list.
1118 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1119 if (!LScopes.isCurrentFunctionScope(Scope))
1121 DIVariable DV = Var->getVariable();
1122 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1124 unsigned ArgNo = DV.getArgNumber();
1128 size_t Size = CurrentFnArguments.size();
1130 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1131 // llvm::Function argument size is not good indicator of how many
1132 // arguments does the function have at source level.
1134 CurrentFnArguments.resize(ArgNo * 2);
1135 CurrentFnArguments[ArgNo - 1] = Var;
1139 // Collect variable information from side table maintained by MMI.
1140 void DwarfDebug::collectVariableInfoFromMMITable(
1141 SmallPtrSet<const MDNode *, 16> &Processed) {
1142 for (const auto &VI : MMI->getVariableDbgInfo()) {
1145 Processed.insert(VI.Var);
1146 DIVariable DV(VI.Var);
1147 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1149 // If variable scope is not found then skip this variable.
1153 DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VI.Loc);
1154 DbgVariable *RegVar = new DbgVariable(DV, AbsDbgVariable, this);
1155 RegVar->setFrameIndex(VI.Slot);
1156 if (!addCurrentFnArgument(RegVar, Scope))
1157 addScopeVariable(Scope, RegVar);
1159 AbsDbgVariable->setFrameIndex(VI.Slot);
1163 // Return true if debug value, encoded by DBG_VALUE instruction, is in a
1165 static bool isDbgValueInDefinedReg(const MachineInstr *MI) {
1166 assert(MI->isDebugValue() && "Invalid DBG_VALUE machine instruction!");
1167 return MI->getNumOperands() == 3 && MI->getOperand(0).isReg() &&
1168 MI->getOperand(0).getReg() &&
1169 (MI->getOperand(1).isImm() ||
1170 (MI->getOperand(1).isReg() && MI->getOperand(1).getReg() == 0U));
1173 // Get .debug_loc entry for the instruction range starting at MI.
1174 static DebugLocEntry getDebugLocEntry(AsmPrinter *Asm,
1175 const MCSymbol *FLabel,
1176 const MCSymbol *SLabel,
1177 const MachineInstr *MI) {
1178 const MDNode *Var = MI->getOperand(MI->getNumOperands() - 1).getMetadata();
1180 assert(MI->getNumOperands() == 3);
1181 if (MI->getOperand(0).isReg()) {
1182 MachineLocation MLoc;
1183 // If the second operand is an immediate, this is a
1184 // register-indirect address.
1185 if (!MI->getOperand(1).isImm())
1186 MLoc.set(MI->getOperand(0).getReg());
1188 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1189 return DebugLocEntry(FLabel, SLabel, MLoc, Var);
1191 if (MI->getOperand(0).isImm())
1192 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getImm());
1193 if (MI->getOperand(0).isFPImm())
1194 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getFPImm());
1195 if (MI->getOperand(0).isCImm())
1196 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getCImm());
1198 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1201 // Find variables for each lexical scope.
1203 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1205 // Grab the variable info that was squirreled away in the MMI side-table.
1206 collectVariableInfoFromMMITable(Processed);
1208 for (const MDNode *Var : UserVariables) {
1209 if (Processed.count(Var))
1212 // History contains relevant DBG_VALUE instructions for Var and instructions
1214 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1215 if (History.empty())
1217 const MachineInstr *MInsn = History.front();
1220 LexicalScope *Scope = NULL;
1221 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1222 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1223 Scope = LScopes.getCurrentFunctionScope();
1224 else if (MDNode *IA = DV.getInlinedAt())
1225 Scope = LScopes.findInlinedScope(DebugLoc::getFromDILocation(IA));
1227 Scope = LScopes.findLexicalScope(cast<MDNode>(DV->getOperand(1)));
1228 // If variable scope is not found then skip this variable.
1232 Processed.insert(DV);
1233 assert(MInsn->isDebugValue() && "History must begin with debug value");
1234 DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
1235 DbgVariable *RegVar = new DbgVariable(DV, AbsVar, this);
1236 if (!addCurrentFnArgument(RegVar, Scope))
1237 addScopeVariable(Scope, RegVar);
1239 AbsVar->setMInsn(MInsn);
1241 // Simplify ranges that are fully coalesced.
1242 if (History.size() <= 1 ||
1243 (History.size() == 2 && MInsn->isIdenticalTo(History.back()))) {
1244 RegVar->setMInsn(MInsn);
1248 // Handle multiple DBG_VALUE instructions describing one variable.
1249 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1251 for (SmallVectorImpl<const MachineInstr *>::const_iterator
1252 HI = History.begin(),
1255 const MachineInstr *Begin = *HI;
1256 assert(Begin->isDebugValue() && "Invalid History entry");
1258 // Check if DBG_VALUE is truncating a range.
1259 if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1260 !Begin->getOperand(0).getReg())
1263 // Compute the range for a register location.
1264 const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
1265 const MCSymbol *SLabel = 0;
1268 // If Begin is the last instruction in History then its value is valid
1269 // until the end of the function.
1270 SLabel = FunctionEndSym;
1272 const MachineInstr *End = HI[1];
1273 DEBUG(dbgs() << "DotDebugLoc Pair:\n"
1274 << "\t" << *Begin << "\t" << *End << "\n");
1275 if (End->isDebugValue())
1276 SLabel = getLabelBeforeInsn(End);
1278 // End is a normal instruction clobbering the range.
1279 SLabel = getLabelAfterInsn(End);
1280 assert(SLabel && "Forgot label after clobber instruction");
1285 // The value is valid until the next DBG_VALUE or clobber.
1286 DotDebugLocEntries.push_back(
1287 getDebugLocEntry(Asm, FLabel, SLabel, Begin));
1289 DotDebugLocEntries.push_back(DebugLocEntry());
1292 // Collect info for variables that were optimized out.
1293 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1294 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1295 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1296 DIVariable DV(Variables.getElement(i));
1297 if (!DV || !DV.isVariable() || !Processed.insert(DV))
1299 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
1300 addScopeVariable(Scope, new DbgVariable(DV, NULL, this));
1304 // Return Label preceding the instruction.
1305 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1306 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1307 assert(Label && "Didn't insert label before instruction");
1311 // Return Label immediately following the instruction.
1312 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1313 return LabelsAfterInsn.lookup(MI);
1316 // Process beginning of an instruction.
1317 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1320 // Check if source location changes, but ignore DBG_VALUE locations.
1321 if (!MI->isDebugValue()) {
1322 DebugLoc DL = MI->getDebugLoc();
1323 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1326 if (DL == PrologEndLoc) {
1327 Flags |= DWARF2_FLAG_PROLOGUE_END;
1328 PrologEndLoc = DebugLoc();
1330 if (PrologEndLoc.isUnknown())
1331 Flags |= DWARF2_FLAG_IS_STMT;
1333 if (!DL.isUnknown()) {
1334 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1335 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1337 recordSourceLine(0, 0, 0, 0);
1341 // Insert labels where requested.
1342 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1343 LabelsBeforeInsn.find(MI);
1346 if (I == LabelsBeforeInsn.end())
1349 // Label already assigned.
1354 PrevLabel = MMI->getContext().CreateTempSymbol();
1355 Asm->OutStreamer.EmitLabel(PrevLabel);
1357 I->second = PrevLabel;
1360 // Process end of an instruction.
1361 void DwarfDebug::endInstruction() {
1363 // Don't create a new label after DBG_VALUE instructions.
1364 // They don't generate code.
1365 if (!CurMI->isDebugValue())
1368 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1369 LabelsAfterInsn.find(CurMI);
1373 if (I == LabelsAfterInsn.end())
1376 // Label already assigned.
1380 // We need a label after this instruction.
1382 PrevLabel = MMI->getContext().CreateTempSymbol();
1383 Asm->OutStreamer.EmitLabel(PrevLabel);
1385 I->second = PrevLabel;
1388 // Each LexicalScope has first instruction and last instruction to mark
1389 // beginning and end of a scope respectively. Create an inverse map that list
1390 // scopes starts (and ends) with an instruction. One instruction may start (or
1391 // end) multiple scopes. Ignore scopes that are not reachable.
1392 void DwarfDebug::identifyScopeMarkers() {
1393 SmallVector<LexicalScope *, 4> WorkList;
1394 WorkList.push_back(LScopes.getCurrentFunctionScope());
1395 while (!WorkList.empty()) {
1396 LexicalScope *S = WorkList.pop_back_val();
1398 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1399 if (!Children.empty())
1400 WorkList.append(Children.begin(), Children.end());
1402 if (S->isAbstractScope())
1405 for (const InsnRange &R : S->getRanges()) {
1406 assert(R.first && "InsnRange does not have first instruction!");
1407 assert(R.second && "InsnRange does not have second instruction!");
1408 requestLabelBeforeInsn(R.first);
1409 requestLabelAfterInsn(R.second);
1414 // Gather pre-function debug information. Assumes being called immediately
1415 // after the function entry point has been emitted.
1416 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1419 // If there's no debug info for the function we're not going to do anything.
1420 if (!MMI->hasDebugInfo())
1423 // Grab the lexical scopes for the function, if we don't have any of those
1424 // then we're not going to be able to do anything.
1425 LScopes.initialize(*MF);
1426 if (LScopes.empty()) {
1427 // If we don't have a lexical scope for this function then there will
1428 // be a hole in the range information. Keep note of this.
1429 UsedNonDefaultText = true;
1433 assert(UserVariables.empty() && DbgValues.empty() && "Maps weren't cleaned");
1435 // Make sure that each lexical scope will have a begin/end label.
1436 identifyScopeMarkers();
1438 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1439 // belongs to so that we add to the correct per-cu line table in the
1441 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1442 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1443 assert(TheCU && "Unable to find compile unit!");
1444 if (Asm->OutStreamer.hasRawTextSupport())
1445 // Use a single line table if we are generating assembly.
1446 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1448 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1450 // Check the current section against the standard text section. If different
1451 // keep track so that we will know when we're emitting functions into multiple
1453 if (Asm->getObjFileLowering().getTextSection() != Asm->getCurrentSection())
1454 UsedNonDefaultText = true;
1456 // Emit a label for the function so that we have a beginning address.
1457 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1458 // Assumes in correct section after the entry point.
1459 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1461 const TargetRegisterInfo *TRI = Asm->TM.getRegisterInfo();
1462 // LiveUserVar - Map physreg numbers to the MDNode they contain.
1463 std::vector<const MDNode *> LiveUserVar(TRI->getNumRegs());
1465 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); I != E;
1467 bool AtBlockEntry = true;
1468 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
1470 const MachineInstr *MI = II;
1472 if (MI->isDebugValue()) {
1473 assert(MI->getNumOperands() > 1 && "Invalid machine instruction!");
1475 // Keep track of user variables.
1477 MI->getOperand(MI->getNumOperands() - 1).getMetadata();
1479 // Variable is in a register, we need to check for clobbers.
1480 if (isDbgValueInDefinedReg(MI))
1481 LiveUserVar[MI->getOperand(0).getReg()] = Var;
1483 // Check the history of this variable.
1484 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1485 if (History.empty()) {
1486 UserVariables.push_back(Var);
1487 // The first mention of a function argument gets the FunctionBeginSym
1488 // label, so arguments are visible when breaking at function entry.
1490 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1491 getDISubprogram(DV.getContext()).describes(MF->getFunction()))
1492 LabelsBeforeInsn[MI] = FunctionBeginSym;
1494 // We have seen this variable before. Try to coalesce DBG_VALUEs.
1495 const MachineInstr *Prev = History.back();
1496 if (Prev->isDebugValue()) {
1497 // Coalesce identical entries at the end of History.
1498 if (History.size() >= 2 &&
1499 Prev->isIdenticalTo(History[History.size() - 2])) {
1500 DEBUG(dbgs() << "Coalescing identical DBG_VALUE entries:\n"
1501 << "\t" << *Prev << "\t"
1502 << *History[History.size() - 2] << "\n");
1506 // Terminate old register assignments that don't reach MI;
1507 MachineFunction::const_iterator PrevMBB = Prev->getParent();
1508 if (PrevMBB != I && (!AtBlockEntry || std::next(PrevMBB) != I) &&
1509 isDbgValueInDefinedReg(Prev)) {
1510 // Previous register assignment needs to terminate at the end of
1512 MachineBasicBlock::const_iterator LastMI =
1513 PrevMBB->getLastNonDebugInstr();
1514 if (LastMI == PrevMBB->end()) {
1515 // Drop DBG_VALUE for empty range.
1516 DEBUG(dbgs() << "Dropping DBG_VALUE for empty range:\n"
1517 << "\t" << *Prev << "\n");
1519 } else if (std::next(PrevMBB) != PrevMBB->getParent()->end())
1520 // Terminate after LastMI.
1521 History.push_back(LastMI);
1525 History.push_back(MI);
1527 // Not a DBG_VALUE instruction.
1528 if (!MI->isPosition())
1529 AtBlockEntry = false;
1531 // First known non-DBG_VALUE and non-frame setup location marks
1532 // the beginning of the function body.
1533 if (!MI->getFlag(MachineInstr::FrameSetup) &&
1534 (PrologEndLoc.isUnknown() && !MI->getDebugLoc().isUnknown()))
1535 PrologEndLoc = MI->getDebugLoc();
1537 // Check if the instruction clobbers any registers with debug vars.
1538 for (const MachineOperand &MO : MI->operands()) {
1539 if (!MO.isReg() || !MO.isDef() || !MO.getReg())
1541 for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid();
1544 const MDNode *Var = LiveUserVar[Reg];
1547 // Reg is now clobbered.
1548 LiveUserVar[Reg] = 0;
1550 // Was MD last defined by a DBG_VALUE referring to Reg?
1551 DbgValueHistoryMap::iterator HistI = DbgValues.find(Var);
1552 if (HistI == DbgValues.end())
1554 SmallVectorImpl<const MachineInstr *> &History = HistI->second;
1555 if (History.empty())
1557 const MachineInstr *Prev = History.back();
1558 // Sanity-check: Register assignments are terminated at the end of
1560 if (!Prev->isDebugValue() || Prev->getParent() != MI->getParent())
1562 // Is the variable still in Reg?
1563 if (!isDbgValueInDefinedReg(Prev) ||
1564 Prev->getOperand(0).getReg() != Reg)
1566 // Var is clobbered. Make sure the next instruction gets a label.
1567 History.push_back(MI);
1574 for (auto &I : DbgValues) {
1575 SmallVectorImpl<const MachineInstr *> &History = I.second;
1576 if (History.empty())
1579 // Make sure the final register assignments are terminated.
1580 const MachineInstr *Prev = History.back();
1581 if (Prev->isDebugValue() && isDbgValueInDefinedReg(Prev)) {
1582 const MachineBasicBlock *PrevMBB = Prev->getParent();
1583 MachineBasicBlock::const_iterator LastMI =
1584 PrevMBB->getLastNonDebugInstr();
1585 if (LastMI == PrevMBB->end())
1586 // Drop DBG_VALUE for empty range.
1588 else if (PrevMBB != &PrevMBB->getParent()->back()) {
1589 // Terminate after LastMI.
1590 History.push_back(LastMI);
1593 // Request labels for the full history.
1594 for (const MachineInstr *MI : History) {
1595 if (MI->isDebugValue())
1596 requestLabelBeforeInsn(MI);
1598 requestLabelAfterInsn(MI);
1602 PrevInstLoc = DebugLoc();
1603 PrevLabel = FunctionBeginSym;
1605 // Record beginning of function.
1606 if (!PrologEndLoc.isUnknown()) {
1607 DebugLoc FnStartDL =
1608 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1610 FnStartDL.getLine(), FnStartDL.getCol(),
1611 FnStartDL.getScope(MF->getFunction()->getContext()),
1612 // We'd like to list the prologue as "not statements" but GDB behaves
1613 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1614 DWARF2_FLAG_IS_STMT);
1618 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1619 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1620 DIVariable DV = Var->getVariable();
1621 // Variables with positive arg numbers are parameters.
1622 if (unsigned ArgNum = DV.getArgNumber()) {
1623 // Keep all parameters in order at the start of the variable list to ensure
1624 // function types are correct (no out-of-order parameters)
1626 // This could be improved by only doing it for optimized builds (unoptimized
1627 // builds have the right order to begin with), searching from the back (this
1628 // would catch the unoptimized case quickly), or doing a binary search
1629 // rather than linear search.
1630 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1631 while (I != Vars.end()) {
1632 unsigned CurNum = (*I)->getVariable().getArgNumber();
1633 // A local (non-parameter) variable has been found, insert immediately
1637 // A later indexed parameter has been found, insert immediately before it.
1638 if (CurNum > ArgNum)
1642 Vars.insert(I, Var);
1646 Vars.push_back(Var);
1649 // Gather and emit post-function debug information.
1650 void DwarfDebug::endFunction(const MachineFunction *MF) {
1651 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1652 // though the beginFunction may not be called at all.
1653 // We should handle both cases.
1657 assert(CurFn == MF);
1660 if (!MMI->hasDebugInfo() || LScopes.empty()) {
1665 // Define end label for subprogram.
1666 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1667 // Assumes in correct section after the entry point.
1668 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1670 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1671 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1673 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1674 collectVariableInfo(ProcessedVars);
1676 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1677 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1678 assert(TheCU && "Unable to find compile unit!");
1680 // Construct abstract scopes.
1681 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1682 DISubprogram SP(AScope->getScopeNode());
1683 if (SP.isSubprogram()) {
1684 // Collect info for variables that were optimized out.
1685 DIArray Variables = SP.getVariables();
1686 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1687 DIVariable DV(Variables.getElement(i));
1688 if (!DV || !DV.isVariable() || !ProcessedVars.insert(DV))
1690 // Check that DbgVariable for DV wasn't created earlier, when
1691 // findAbstractVariable() was called for inlined instance of DV.
1692 LLVMContext &Ctx = DV->getContext();
1693 DIVariable CleanDV = cleanseInlinedVariable(DV, Ctx);
1694 if (AbstractVariables.lookup(CleanDV))
1696 if (LexicalScope *Scope = LScopes.findAbstractScope(DV.getContext()))
1697 addScopeVariable(Scope, new DbgVariable(DV, NULL, this));
1700 if (ProcessedSPNodes.count(AScope->getScopeNode()) == 0)
1701 constructScopeDIE(TheCU, AScope);
1704 DIE *CurFnDIE = constructScopeDIE(TheCU, FnScope);
1705 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1706 TheCU->addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1708 // Add the range of this function to the list of ranges for the CU.
1709 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1710 TheCU->addRange(std::move(Span));
1713 for (auto &I : ScopeVariables)
1714 DeleteContainerPointers(I.second);
1715 ScopeVariables.clear();
1716 DeleteContainerPointers(CurrentFnArguments);
1717 UserVariables.clear();
1719 AbstractVariables.clear();
1720 LabelsBeforeInsn.clear();
1721 LabelsAfterInsn.clear();
1726 // Register a source line with debug info. Returns the unique label that was
1727 // emitted and which provides correspondence to the source line list.
1728 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1733 unsigned Discriminator = 0;
1735 DIDescriptor Scope(S);
1737 if (Scope.isCompileUnit()) {
1738 DICompileUnit CU(S);
1739 Fn = CU.getFilename();
1740 Dir = CU.getDirectory();
1741 } else if (Scope.isFile()) {
1743 Fn = F.getFilename();
1744 Dir = F.getDirectory();
1745 } else if (Scope.isSubprogram()) {
1747 Fn = SP.getFilename();
1748 Dir = SP.getDirectory();
1749 } else if (Scope.isLexicalBlockFile()) {
1750 DILexicalBlockFile DBF(S);
1751 Fn = DBF.getFilename();
1752 Dir = DBF.getDirectory();
1753 } else if (Scope.isLexicalBlock()) {
1754 DILexicalBlock DB(S);
1755 Fn = DB.getFilename();
1756 Dir = DB.getDirectory();
1757 Discriminator = DB.getDiscriminator();
1759 llvm_unreachable("Unexpected scope info");
1761 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1762 Src = static_cast<DwarfCompileUnit *>(InfoHolder.getUnits()[CUID])
1763 ->getOrCreateSourceID(Fn, Dir);
1765 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1769 //===----------------------------------------------------------------------===//
1771 //===----------------------------------------------------------------------===//
1773 // Compute the size and offset of a DIE. The offset is relative to start of the
1774 // CU. It returns the offset after laying out the DIE.
1775 unsigned DwarfFile::computeSizeAndOffset(DIE *Die, unsigned Offset) {
1776 // Record the abbreviation.
1777 assignAbbrevNumber(Die->getAbbrev());
1779 // Get the abbreviation for this DIE.
1780 const DIEAbbrev &Abbrev = Die->getAbbrev();
1783 Die->setOffset(Offset);
1785 // Start the size with the size of abbreviation code.
1786 Offset += getULEB128Size(Die->getAbbrevNumber());
1788 const SmallVectorImpl<DIEValue *> &Values = Die->getValues();
1789 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1791 // Size the DIE attribute values.
1792 for (unsigned i = 0, N = Values.size(); i < N; ++i)
1793 // Size attribute value.
1794 Offset += Values[i]->SizeOf(Asm, AbbrevData[i].getForm());
1796 // Get the children.
1797 const std::vector<DIE *> &Children = Die->getChildren();
1799 // Size the DIE children if any.
1800 if (!Children.empty()) {
1801 assert(Abbrev.hasChildren() && "Children flag not set");
1803 for (DIE *Child : Children)
1804 Offset = computeSizeAndOffset(Child, Offset);
1806 // End of children marker.
1807 Offset += sizeof(int8_t);
1810 Die->setSize(Offset - Die->getOffset());
1814 // Compute the size and offset for each DIE.
1815 void DwarfFile::computeSizeAndOffsets() {
1816 // Offset from the first CU in the debug info section is 0 initially.
1817 unsigned SecOffset = 0;
1819 // Iterate over each compile unit and set the size and offsets for each
1820 // DIE within each compile unit. All offsets are CU relative.
1821 for (DwarfUnit *TheU : CUs) {
1822 TheU->setDebugInfoOffset(SecOffset);
1824 // CU-relative offset is reset to 0 here.
1825 unsigned Offset = sizeof(int32_t) + // Length of Unit Info
1826 TheU->getHeaderSize(); // Unit-specific headers
1828 // EndOffset here is CU-relative, after laying out
1829 // all of the CU DIE.
1830 unsigned EndOffset = computeSizeAndOffset(TheU->getUnitDie(), Offset);
1831 SecOffset += EndOffset;
1835 // Emit initial Dwarf sections with a label at the start of each one.
1836 void DwarfDebug::emitSectionLabels() {
1837 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1839 // Dwarf sections base addresses.
1840 DwarfInfoSectionSym =
1841 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1842 if (useSplitDwarf())
1843 DwarfInfoDWOSectionSym =
1844 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1845 DwarfAbbrevSectionSym =
1846 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1847 if (useSplitDwarf())
1848 DwarfAbbrevDWOSectionSym = emitSectionSym(
1849 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1850 if (GenerateARangeSection)
1851 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1853 DwarfLineSectionSym =
1854 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1855 emitSectionSym(Asm, TLOF.getDwarfLocSection());
1856 if (GenerateGnuPubSections) {
1857 DwarfGnuPubNamesSectionSym =
1858 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1859 DwarfGnuPubTypesSectionSym =
1860 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1861 } else if (HasDwarfPubSections) {
1862 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1863 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1866 DwarfStrSectionSym =
1867 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1868 if (useSplitDwarf()) {
1869 DwarfStrDWOSectionSym =
1870 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1871 DwarfAddrSectionSym =
1872 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1874 DwarfDebugRangeSectionSym =
1875 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1877 DwarfDebugLocSectionSym =
1878 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1881 // Recursively emits a debug information entry.
1882 void DwarfDebug::emitDIE(DIE *Die) {
1883 // Get the abbreviation for this DIE.
1884 const DIEAbbrev &Abbrev = Die->getAbbrev();
1886 // Emit the code (index) for the abbreviation.
1887 if (Asm->isVerbose())
1888 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1889 "] 0x" + Twine::utohexstr(Die->getOffset()) +
1890 ":0x" + Twine::utohexstr(Die->getSize()) + " " +
1891 dwarf::TagString(Abbrev.getTag()));
1892 Asm->EmitULEB128(Abbrev.getNumber());
1894 const SmallVectorImpl<DIEValue *> &Values = Die->getValues();
1895 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1897 // Emit the DIE attribute values.
1898 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1899 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1900 dwarf::Form Form = AbbrevData[i].getForm();
1901 assert(Form && "Too many attributes for DIE (check abbreviation)");
1903 if (Asm->isVerbose()) {
1904 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1905 if (Attr == dwarf::DW_AT_accessibility)
1906 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1907 cast<DIEInteger>(Values[i])->getValue()));
1910 // Emit an attribute using the defined form.
1911 Values[i]->EmitValue(Asm, Form);
1914 // Emit the DIE children if any.
1915 if (Abbrev.hasChildren()) {
1916 const std::vector<DIE *> &Children = Die->getChildren();
1918 for (DIE *Child : Children)
1921 Asm->OutStreamer.AddComment("End Of Children Mark");
1926 // Emit the various dwarf units to the unit section USection with
1927 // the abbreviations going into ASection.
1928 void DwarfFile::emitUnits(DwarfDebug *DD, const MCSection *ASection,
1929 const MCSymbol *ASectionSym) {
1930 for (DwarfUnit *TheU : CUs) {
1931 DIE *Die = TheU->getUnitDie();
1932 const MCSection *USection = TheU->getSection();
1933 Asm->OutStreamer.SwitchSection(USection);
1935 // Emit the compile units header.
1936 Asm->OutStreamer.EmitLabel(TheU->getLabelBegin());
1938 // Emit size of content not including length itself
1939 Asm->OutStreamer.AddComment("Length of Unit");
1940 Asm->EmitInt32(TheU->getHeaderSize() + Die->getSize());
1942 TheU->emitHeader(ASection, ASectionSym);
1945 Asm->OutStreamer.EmitLabel(TheU->getLabelEnd());
1949 // Emit the debug info section.
1950 void DwarfDebug::emitDebugInfo() {
1951 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1953 Holder.emitUnits(this, Asm->getObjFileLowering().getDwarfAbbrevSection(),
1954 DwarfAbbrevSectionSym);
1957 // Emit the abbreviation section.
1958 void DwarfDebug::emitAbbreviations() {
1959 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1961 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1964 void DwarfFile::emitAbbrevs(const MCSection *Section) {
1965 // Check to see if it is worth the effort.
1966 if (!Abbreviations.empty()) {
1967 // Start the debug abbrev section.
1968 Asm->OutStreamer.SwitchSection(Section);
1970 // For each abbrevation.
1971 for (const DIEAbbrev *Abbrev : Abbreviations) {
1972 // Emit the abbrevations code (base 1 index.)
1973 Asm->EmitULEB128(Abbrev->getNumber(), "Abbreviation Code");
1975 // Emit the abbreviations data.
1979 // Mark end of abbreviations.
1980 Asm->EmitULEB128(0, "EOM(3)");
1984 // Emit the last address of the section and the end of the line matrix.
1985 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1986 // Define last address of section.
1987 Asm->OutStreamer.AddComment("Extended Op");
1990 Asm->OutStreamer.AddComment("Op size");
1991 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1992 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1993 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1995 Asm->OutStreamer.AddComment("Section end label");
1997 Asm->OutStreamer.EmitSymbolValue(
1998 Asm->GetTempSymbol("section_end", SectionEnd),
1999 Asm->getDataLayout().getPointerSize());
2001 // Mark end of matrix.
2002 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
2008 // Emit visible names into a hashed accelerator table section.
2009 void DwarfDebug::emitAccelNames() {
2011 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2012 for (DwarfUnit *TheU : getUnits()) {
2013 for (const auto &GI : TheU->getAccelNames()) {
2014 StringRef Name = GI.getKey();
2015 for (const DIE *D : GI.second)
2016 AT.AddName(Name, D);
2020 AT.FinalizeTable(Asm, "Names");
2021 Asm->OutStreamer.SwitchSection(
2022 Asm->getObjFileLowering().getDwarfAccelNamesSection());
2023 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
2024 Asm->OutStreamer.EmitLabel(SectionBegin);
2026 // Emit the full data.
2027 AT.Emit(Asm, SectionBegin, &InfoHolder);
2030 // Emit objective C classes and categories into a hashed accelerator table
2032 void DwarfDebug::emitAccelObjC() {
2034 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2035 for (DwarfUnit *TheU : getUnits()) {
2036 for (const auto &GI : TheU->getAccelObjC()) {
2037 StringRef Name = GI.getKey();
2038 for (const DIE *D : GI.second)
2039 AT.AddName(Name, D);
2043 AT.FinalizeTable(Asm, "ObjC");
2044 Asm->OutStreamer.SwitchSection(
2045 Asm->getObjFileLowering().getDwarfAccelObjCSection());
2046 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
2047 Asm->OutStreamer.EmitLabel(SectionBegin);
2049 // Emit the full data.
2050 AT.Emit(Asm, SectionBegin, &InfoHolder);
2053 // Emit namespace dies into a hashed accelerator table.
2054 void DwarfDebug::emitAccelNamespaces() {
2056 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2057 for (DwarfUnit *TheU : getUnits()) {
2058 for (const auto &GI : TheU->getAccelNamespace()) {
2059 StringRef Name = GI.getKey();
2060 for (const DIE *D : GI.second)
2061 AT.AddName(Name, D);
2065 AT.FinalizeTable(Asm, "namespac");
2066 Asm->OutStreamer.SwitchSection(
2067 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
2068 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
2069 Asm->OutStreamer.EmitLabel(SectionBegin);
2071 // Emit the full data.
2072 AT.Emit(Asm, SectionBegin, &InfoHolder);
2075 // Emit type dies into a hashed accelerator table.
2076 void DwarfDebug::emitAccelTypes() {
2077 std::vector<DwarfAccelTable::Atom> Atoms;
2079 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2081 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2));
2083 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1));
2084 DwarfAccelTable AT(Atoms);
2085 for (DwarfUnit *TheU : getUnits()) {
2086 for (const auto &GI : TheU->getAccelTypes()) {
2087 StringRef Name = GI.getKey();
2088 for (const auto &DI : GI.second)
2089 AT.AddName(Name, DI.first, DI.second);
2093 AT.FinalizeTable(Asm, "types");
2094 Asm->OutStreamer.SwitchSection(
2095 Asm->getObjFileLowering().getDwarfAccelTypesSection());
2096 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
2097 Asm->OutStreamer.EmitLabel(SectionBegin);
2099 // Emit the full data.
2100 AT.Emit(Asm, SectionBegin, &InfoHolder);
2103 // Public name handling.
2104 // The format for the various pubnames:
2106 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
2107 // for the DIE that is named.
2109 // gnu pubnames - offset/index value/name tuples where the offset is the offset
2110 // into the CU and the index value is computed according to the type of value
2111 // for the DIE that is named.
2113 // For type units the offset is the offset of the skeleton DIE. For split dwarf
2114 // it's the offset within the debug_info/debug_types dwo section, however, the
2115 // reference in the pubname header doesn't change.
2117 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
2118 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
2120 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
2122 // We could have a specification DIE that has our most of our knowledge,
2123 // look for that now.
2124 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
2126 DIE *SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
2127 if (SpecDIE->findAttribute(dwarf::DW_AT_external))
2128 Linkage = dwarf::GIEL_EXTERNAL;
2129 } else if (Die->findAttribute(dwarf::DW_AT_external))
2130 Linkage = dwarf::GIEL_EXTERNAL;
2132 switch (Die->getTag()) {
2133 case dwarf::DW_TAG_class_type:
2134 case dwarf::DW_TAG_structure_type:
2135 case dwarf::DW_TAG_union_type:
2136 case dwarf::DW_TAG_enumeration_type:
2137 return dwarf::PubIndexEntryDescriptor(
2138 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
2139 ? dwarf::GIEL_STATIC
2140 : dwarf::GIEL_EXTERNAL);
2141 case dwarf::DW_TAG_typedef:
2142 case dwarf::DW_TAG_base_type:
2143 case dwarf::DW_TAG_subrange_type:
2144 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
2145 case dwarf::DW_TAG_namespace:
2146 return dwarf::GIEK_TYPE;
2147 case dwarf::DW_TAG_subprogram:
2148 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
2149 case dwarf::DW_TAG_constant:
2150 case dwarf::DW_TAG_variable:
2151 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
2152 case dwarf::DW_TAG_enumerator:
2153 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
2154 dwarf::GIEL_STATIC);
2156 return dwarf::GIEK_NONE;
2160 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
2162 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
2163 const MCSection *PSec =
2164 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
2165 : Asm->getObjFileLowering().getDwarfPubNamesSection();
2167 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
2170 void DwarfDebug::emitDebugPubSection(
2171 bool GnuStyle, const MCSection *PSec, StringRef Name,
2172 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
2173 for (const auto &NU : CUMap) {
2174 DwarfCompileUnit *TheU = NU.second;
2176 const auto &Globals = (TheU->*Accessor)();
2178 if (Globals.empty())
2181 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2183 unsigned ID = TheU->getUniqueID();
2185 // Start the dwarf pubnames section.
2186 Asm->OutStreamer.SwitchSection(PSec);
2189 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2190 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2191 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2192 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2194 Asm->OutStreamer.EmitLabel(BeginLabel);
2196 Asm->OutStreamer.AddComment("DWARF Version");
2197 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2199 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2200 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2202 Asm->OutStreamer.AddComment("Compilation Unit Length");
2203 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2205 // Emit the pubnames for this compilation unit.
2206 for (const auto &GI : Globals) {
2207 const char *Name = GI.getKeyData();
2208 const DIE *Entity = GI.second;
2210 Asm->OutStreamer.AddComment("DIE offset");
2211 Asm->EmitInt32(Entity->getOffset());
2214 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2215 Asm->OutStreamer.AddComment(
2216 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2217 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2218 Asm->EmitInt8(Desc.toBits());
2221 Asm->OutStreamer.AddComment("External Name");
2222 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2225 Asm->OutStreamer.AddComment("End Mark");
2227 Asm->OutStreamer.EmitLabel(EndLabel);
2231 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2232 const MCSection *PSec =
2233 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2234 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2236 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2239 // Emit strings into a string section.
2240 void DwarfFile::emitStrings(const MCSection *StrSection,
2241 const MCSection *OffsetSection = NULL,
2242 const MCSymbol *StrSecSym = NULL) {
2244 if (StringPool.empty())
2247 // Start the dwarf str section.
2248 Asm->OutStreamer.SwitchSection(StrSection);
2250 // Get all of the string pool entries and put them in an array by their ID so
2251 // we can sort them.
2252 SmallVector<std::pair<unsigned, const StrPool::value_type *>, 64 > Entries;
2254 for (const auto &I : StringPool)
2255 Entries.push_back(std::make_pair(I.second.second, &I));
2257 array_pod_sort(Entries.begin(), Entries.end());
2259 for (const auto &Entry : Entries) {
2260 // Emit a label for reference from debug information entries.
2261 Asm->OutStreamer.EmitLabel(Entry.second->getValue().first);
2263 // Emit the string itself with a terminating null byte.
2264 Asm->OutStreamer.EmitBytes(StringRef(Entry.second->getKeyData(),
2265 Entry.second->getKeyLength() + 1));
2268 // If we've got an offset section go ahead and emit that now as well.
2269 if (OffsetSection) {
2270 Asm->OutStreamer.SwitchSection(OffsetSection);
2271 unsigned offset = 0;
2272 unsigned size = 4; // FIXME: DWARF64 is 8.
2273 for (const auto &Entry : Entries) {
2274 Asm->OutStreamer.EmitIntValue(offset, size);
2275 offset += Entry.second->getKeyLength() + 1;
2280 // Emit addresses into the section given.
2281 void DwarfFile::emitAddresses(const MCSection *AddrSection) {
2283 if (AddressPool.empty())
2286 // Start the dwarf addr section.
2287 Asm->OutStreamer.SwitchSection(AddrSection);
2289 // Order the address pool entries by ID
2290 SmallVector<const MCExpr *, 64> Entries(AddressPool.size());
2292 for (const auto &I : AddressPool)
2293 Entries[I.second.Number] =
2295 ? Asm->getObjFileLowering().getDebugThreadLocalSymbol(I.first)
2296 : MCSymbolRefExpr::Create(I.first, Asm->OutContext);
2298 for (const MCExpr *Entry : Entries)
2299 Asm->OutStreamer.EmitValue(Entry, Asm->getDataLayout().getPointerSize());
2302 // Emit visible names into a debug str section.
2303 void DwarfDebug::emitDebugStr() {
2304 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2305 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2308 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2309 const DebugLocEntry &Entry) {
2310 DIVariable DV(Entry.getVariable());
2311 if (Entry.isInt()) {
2312 DIBasicType BTy(resolve(DV.getType()));
2313 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2314 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2315 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2316 Streamer.EmitSLEB128(Entry.getInt());
2318 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2319 Streamer.EmitULEB128(Entry.getInt());
2321 } else if (Entry.isLocation()) {
2322 MachineLocation Loc = Entry.getLoc();
2323 if (!DV.hasComplexAddress())
2325 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2327 // Complex address entry.
2328 unsigned N = DV.getNumAddrElements();
2330 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2331 if (Loc.getOffset()) {
2333 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2334 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2335 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2336 Streamer.EmitSLEB128(DV.getAddrElement(1));
2338 // If first address element is OpPlus then emit
2339 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2340 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2341 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2345 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2348 // Emit remaining complex address elements.
2349 for (; i < N; ++i) {
2350 uint64_t Element = DV.getAddrElement(i);
2351 if (Element == DIBuilder::OpPlus) {
2352 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2353 Streamer.EmitULEB128(DV.getAddrElement(++i));
2354 } else if (Element == DIBuilder::OpDeref) {
2356 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2358 llvm_unreachable("unknown Opcode found in complex address");
2362 // else ... ignore constant fp. There is not any good way to
2363 // to represent them here in dwarf.
2367 // Emit locations into the debug loc section.
2368 void DwarfDebug::emitDebugLoc() {
2369 if (DotDebugLocEntries.empty())
2372 for (SmallVectorImpl<DebugLocEntry>::iterator
2373 I = DotDebugLocEntries.begin(),
2374 E = DotDebugLocEntries.end();
2376 DebugLocEntry &Entry = *I;
2377 if (I + 1 != DotDebugLocEntries.end())
2381 // Start the dwarf loc section.
2382 Asm->OutStreamer.SwitchSection(
2383 Asm->getObjFileLowering().getDwarfLocSection());
2384 unsigned char Size = Asm->getDataLayout().getPointerSize();
2385 Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_loc", 0));
2387 for (SmallVectorImpl<DebugLocEntry>::const_iterator
2388 I = DotDebugLocEntries.begin(),
2389 E = DotDebugLocEntries.end();
2390 I != E; ++I, ++index) {
2391 const DebugLocEntry &Entry = *I;
2392 if (Entry.isMerged())
2395 if (Entry.isEmpty()) {
2396 Asm->OutStreamer.EmitIntValue(0, Size);
2397 Asm->OutStreamer.EmitIntValue(0, Size);
2398 Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_loc", index));
2400 // Set up the range.
2401 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2402 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2403 Asm->OutStreamer.AddComment("Loc expr size");
2404 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2405 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2406 Asm->EmitLabelDifference(end, begin, 2);
2407 Asm->OutStreamer.EmitLabel(begin);
2409 APByteStreamer Streamer(*Asm);
2410 emitDebugLocEntry(Streamer, Entry);
2412 Asm->OutStreamer.EmitLabel(end);
2418 const MCSymbol *Start, *End;
2421 // Emit a debug aranges section, containing a CU lookup for any
2422 // address we can tie back to a CU.
2423 void DwarfDebug::emitDebugARanges() {
2424 // Start the dwarf aranges section.
2425 Asm->OutStreamer.SwitchSection(
2426 Asm->getObjFileLowering().getDwarfARangesSection());
2428 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan> > SpansType;
2432 // Build a list of sections used.
2433 std::vector<const MCSection *> Sections;
2434 for (const auto &it : SectionMap) {
2435 const MCSection *Section = it.first;
2436 Sections.push_back(Section);
2439 // Sort the sections into order.
2440 // This is only done to ensure consistent output order across different runs.
2441 std::sort(Sections.begin(), Sections.end(), SectionSort);
2443 // Build a set of address spans, sorted by CU.
2444 for (const MCSection *Section : Sections) {
2445 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2446 if (List.size() < 2)
2449 // Sort the symbols by offset within the section.
2450 std::sort(List.begin(), List.end(),
2451 [&](const SymbolCU &A, const SymbolCU &B) {
2452 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2453 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2455 // Symbols with no order assigned should be placed at the end.
2456 // (e.g. section end labels)
2464 // If we have no section (e.g. common), just write out
2465 // individual spans for each symbol.
2466 if (Section == NULL) {
2467 for (const SymbolCU &Cur : List) {
2469 Span.Start = Cur.Sym;
2472 Spans[Cur.CU].push_back(Span);
2475 // Build spans between each label.
2476 const MCSymbol *StartSym = List[0].Sym;
2477 for (size_t n = 1, e = List.size(); n < e; n++) {
2478 const SymbolCU &Prev = List[n - 1];
2479 const SymbolCU &Cur = List[n];
2481 // Try and build the longest span we can within the same CU.
2482 if (Cur.CU != Prev.CU) {
2484 Span.Start = StartSym;
2486 Spans[Prev.CU].push_back(Span);
2493 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2495 // Build a list of CUs used.
2496 std::vector<DwarfCompileUnit *> CUs;
2497 for (const auto &it : Spans) {
2498 DwarfCompileUnit *CU = it.first;
2502 // Sort the CU list (again, to ensure consistent output order).
2503 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2504 return A->getUniqueID() < B->getUniqueID();
2507 // Emit an arange table for each CU we used.
2508 for (DwarfCompileUnit *CU : CUs) {
2509 std::vector<ArangeSpan> &List = Spans[CU];
2511 // Emit size of content not including length itself.
2512 unsigned ContentSize =
2513 sizeof(int16_t) + // DWARF ARange version number
2514 sizeof(int32_t) + // Offset of CU in the .debug_info section
2515 sizeof(int8_t) + // Pointer Size (in bytes)
2516 sizeof(int8_t); // Segment Size (in bytes)
2518 unsigned TupleSize = PtrSize * 2;
2520 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2522 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2524 ContentSize += Padding;
2525 ContentSize += (List.size() + 1) * TupleSize;
2527 // For each compile unit, write the list of spans it covers.
2528 Asm->OutStreamer.AddComment("Length of ARange Set");
2529 Asm->EmitInt32(ContentSize);
2530 Asm->OutStreamer.AddComment("DWARF Arange version number");
2531 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2532 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2533 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2534 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2535 Asm->EmitInt8(PtrSize);
2536 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2539 Asm->OutStreamer.EmitFill(Padding, 0xff);
2541 for (const ArangeSpan &Span : List) {
2542 Asm->EmitLabelReference(Span.Start, PtrSize);
2544 // Calculate the size as being from the span start to it's end.
2546 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2548 // For symbols without an end marker (e.g. common), we
2549 // write a single arange entry containing just that one symbol.
2550 uint64_t Size = SymSize[Span.Start];
2554 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2558 Asm->OutStreamer.AddComment("ARange terminator");
2559 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2560 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2564 // Emit visible names into a debug ranges section.
2565 void DwarfDebug::emitDebugRanges() {
2566 // Start the dwarf ranges section.
2567 Asm->OutStreamer.SwitchSection(
2568 Asm->getObjFileLowering().getDwarfRangesSection());
2570 // Size for our labels.
2571 unsigned char Size = Asm->getDataLayout().getPointerSize();
2573 // Grab the specific ranges for the compile units in the module.
2574 for (const auto &I : CUMap) {
2575 DwarfCompileUnit *TheCU = I.second;
2577 // Emit a symbol so we can find the beginning of our ranges.
2578 Asm->OutStreamer.EmitLabel(TheCU->getLabelRange());
2580 // Iterate over the misc ranges for the compile units in the module.
2581 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2582 // Emit our symbol so we can find the beginning of the range.
2583 Asm->OutStreamer.EmitLabel(List.getSym());
2585 for (const RangeSpan &Range : List.getRanges()) {
2586 const MCSymbol *Begin = Range.getStart();
2587 const MCSymbol *End = Range.getEnd();
2588 assert(Begin && "Range without a begin symbol?");
2589 assert(End && "Range without an end symbol?");
2590 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2591 Asm->OutStreamer.EmitSymbolValue(End, Size);
2594 // And terminate the list with two 0 values.
2595 Asm->OutStreamer.EmitIntValue(0, Size);
2596 Asm->OutStreamer.EmitIntValue(0, Size);
2599 // Now emit a range for the CU itself.
2600 if (useCURanges() && TheCU->getRanges().size()) {
2601 Asm->OutStreamer.EmitLabel(
2602 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2603 for (const RangeSpan &Range : TheCU->getRanges()) {
2604 const MCSymbol *Begin = Range.getStart();
2605 const MCSymbol *End = Range.getEnd();
2606 assert(Begin && "Range without a begin symbol?");
2607 assert(End && "Range without an end symbol?");
2608 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2609 Asm->OutStreamer.EmitSymbolValue(End, Size);
2611 // And terminate the list with two 0 values.
2612 Asm->OutStreamer.EmitIntValue(0, Size);
2613 Asm->OutStreamer.EmitIntValue(0, Size);
2618 // DWARF5 Experimental Separate Dwarf emitters.
2620 void DwarfDebug::initSkeletonUnit(const DwarfUnit *U, DIE *Die,
2622 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2623 U->getCUNode().getSplitDebugFilename());
2625 // Relocate to the beginning of the addr_base section, else 0 for the
2626 // beginning of the one for this compile unit.
2627 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
2628 NewU->addSectionLabel(Die, dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym);
2630 NewU->addSectionOffset(Die, dwarf::DW_AT_GNU_addr_base, 0);
2632 if (!CompilationDir.empty())
2633 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2635 addGnuPubAttributes(NewU, Die);
2637 SkeletonHolder.addUnit(NewU);
2640 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2641 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2642 // DW_AT_ranges_base, DW_AT_addr_base.
2643 // TODO: Implement DW_AT_ranges_base.
2644 DwarfCompileUnit *DwarfDebug::constructSkeletonCU(const DwarfCompileUnit *CU) {
2646 DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
2647 DwarfCompileUnit *NewCU = new DwarfCompileUnit(
2648 CU->getUniqueID(), Die, CU->getCUNode(), Asm, this, &SkeletonHolder);
2649 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2650 DwarfInfoSectionSym);
2652 NewCU->initStmtList(DwarfLineSectionSym);
2654 initSkeletonUnit(CU, Die, NewCU);
2659 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2661 DwarfTypeUnit *DwarfDebug::constructSkeletonTU(DwarfTypeUnit *TU) {
2662 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2663 *SkeletonHolder.getUnits()[TU->getCU().getUniqueID()]);
2665 DIE *Die = new DIE(dwarf::DW_TAG_type_unit);
2666 DwarfTypeUnit *NewTU =
2667 new DwarfTypeUnit(TU->getUniqueID(), Die, CU, Asm, this, &SkeletonHolder);
2668 NewTU->setTypeSignature(TU->getTypeSignature());
2669 NewTU->setType(NULL);
2671 Asm->getObjFileLowering().getDwarfTypesSection(TU->getTypeSignature()));
2673 initSkeletonUnit(TU, Die, NewTU);
2677 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2678 // compile units that would normally be in debug_info.
2679 void DwarfDebug::emitDebugInfoDWO() {
2680 assert(useSplitDwarf() && "No split dwarf debug info?");
2681 InfoHolder.emitUnits(this,
2682 Asm->getObjFileLowering().getDwarfAbbrevDWOSection(),
2683 DwarfAbbrevDWOSectionSym);
2686 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2687 // abbreviations for the .debug_info.dwo section.
2688 void DwarfDebug::emitDebugAbbrevDWO() {
2689 assert(useSplitDwarf() && "No split dwarf?");
2690 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2693 void DwarfDebug::emitDebugLineDWO() {
2694 assert(useSplitDwarf() && "No split dwarf?");
2695 Asm->OutStreamer.SwitchSection(
2696 Asm->getObjFileLowering().getDwarfLineDWOSection());
2697 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2700 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2701 // string section and is identical in format to traditional .debug_str
2703 void DwarfDebug::emitDebugStrDWO() {
2704 assert(useSplitDwarf() && "No split dwarf?");
2705 const MCSection *OffSec =
2706 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2707 const MCSymbol *StrSym = DwarfStrSectionSym;
2708 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2712 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2713 if (!useSplitDwarf())
2716 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2717 return &SplitTypeUnitFileTable;
2720 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2721 StringRef Identifier, DIE *RefDie,
2722 DICompositeType CTy) {
2723 // Flag the type unit reference as a declaration so that if it contains
2724 // members (implicit special members, static data member definitions, member
2725 // declarations for definitions in this CU, etc) consumers don't get confused
2726 // and think this is a full definition.
2727 CU.addFlag(RefDie, dwarf::DW_AT_declaration);
2729 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2731 CU.addDIETypeSignature(RefDie, *TU);
2735 DIE *UnitDie = new DIE(dwarf::DW_TAG_type_unit);
2736 DwarfTypeUnit *NewTU =
2737 new DwarfTypeUnit(InfoHolder.getUnits().size(), UnitDie, CU, Asm, this,
2738 &InfoHolder, getDwoLineTable(CU));
2740 InfoHolder.addUnit(NewTU);
2742 NewTU->addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2746 Hash.update(Identifier);
2747 // ... take the least significant 8 bytes and return those. Our MD5
2748 // implementation always returns its results in little endian, swap bytes
2750 MD5::MD5Result Result;
2752 uint64_t Signature = *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2753 NewTU->setTypeSignature(Signature);
2754 if (useSplitDwarf())
2755 NewTU->setSkeleton(constructSkeletonTU(NewTU));
2757 CU.applyStmtList(*UnitDie);
2759 NewTU->setType(NewTU->createTypeDIE(CTy));
2763 ? Asm->getObjFileLowering().getDwarfTypesDWOSection(Signature)
2764 : Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2766 CU.addDIETypeSignature(RefDie, *NewTU);
2769 void DwarfDebug::attachLowHighPC(DwarfCompileUnit *Unit, DIE *D,
2770 MCSymbol *Begin, MCSymbol *End) {
2771 Unit->addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2772 if (DwarfVersion < 4)
2773 Unit->addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2775 Unit->addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);