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),
182 UsedNonDefaultText(false),
183 SkeletonHolder(A, "skel_string", DIEValueAllocator) {
185 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = 0;
186 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = DwarfLineSectionSym = 0;
187 DwarfAddrSectionSym = DwarfDebugLocDWOSectionSym = 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++);
460 // Under fission, ranges are specified by constant offsets relative to the
461 // CU's DW_AT_GNU_ranges_base.
463 TheCU->addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
464 DwarfDebugRangeSectionSym);
466 addSectionLabel(Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
467 DwarfDebugRangeSectionSym);
469 RangeSpanList List(RangeSym);
470 for (const InsnRange &R : Range) {
471 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
472 List.addRange(std::move(Span));
475 // Add the range list to the set of ranges to be emitted.
476 TheCU->addRangeList(std::move(List));
479 // Construct new DW_TAG_lexical_block for this scope and attach
480 // DW_AT_low_pc/DW_AT_high_pc labels.
481 DIE *DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit *TheCU,
482 LexicalScope *Scope) {
483 if (isLexicalScopeDIENull(Scope))
486 DIE *ScopeDIE = new DIE(dwarf::DW_TAG_lexical_block);
487 if (Scope->isAbstractScope())
490 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
492 // If we have multiple ranges, emit them into the range section.
493 if (ScopeRanges.size() > 1) {
494 addScopeRangeList(TheCU, ScopeDIE, ScopeRanges);
498 // Construct the address range for this DIE.
499 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
500 MCSymbol *Start = getLabelBeforeInsn(RI->first);
501 MCSymbol *End = getLabelAfterInsn(RI->second);
502 assert(End && "End label should not be null!");
504 assert(Start->isDefined() && "Invalid starting label for an inlined scope!");
505 assert(End->isDefined() && "Invalid end label for an inlined scope!");
507 attachLowHighPC(TheCU, ScopeDIE, Start, End);
512 // This scope represents inlined body of a function. Construct DIE to
513 // represent this concrete inlined copy of the function.
514 DIE *DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit *TheCU,
515 LexicalScope *Scope) {
516 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
517 assert(!ScopeRanges.empty() &&
518 "LexicalScope does not have instruction markers!");
520 if (!Scope->getScopeNode())
522 DIScope DS(Scope->getScopeNode());
523 DISubprogram InlinedSP = getDISubprogram(DS);
524 DIE *OriginDIE = TheCU->getDIE(InlinedSP);
526 DEBUG(dbgs() << "Unable to find original DIE for an inlined subprogram.");
530 DIE *ScopeDIE = new DIE(dwarf::DW_TAG_inlined_subroutine);
531 TheCU->addDIEEntry(ScopeDIE, dwarf::DW_AT_abstract_origin, OriginDIE);
533 // If we have multiple ranges, emit them into the range section.
534 if (ScopeRanges.size() > 1)
535 addScopeRangeList(TheCU, ScopeDIE, ScopeRanges);
537 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
538 MCSymbol *StartLabel = getLabelBeforeInsn(RI->first);
539 MCSymbol *EndLabel = getLabelAfterInsn(RI->second);
541 if (StartLabel == 0 || EndLabel == 0)
542 llvm_unreachable("Unexpected Start and End labels for an inlined scope!");
544 assert(StartLabel->isDefined() &&
545 "Invalid starting label for an inlined scope!");
546 assert(EndLabel->isDefined() && "Invalid end label for an inlined scope!");
548 attachLowHighPC(TheCU, ScopeDIE, StartLabel, EndLabel);
551 InlinedSubprogramDIEs.insert(OriginDIE);
553 // Add the call site information to the DIE.
554 DILocation DL(Scope->getInlinedAt());
556 ScopeDIE, dwarf::DW_AT_call_file, None,
557 TheCU->getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
558 TheCU->addUInt(ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
560 // Add name to the name table, we do this here because we're guaranteed
561 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
562 addSubprogramNames(TheCU, InlinedSP, ScopeDIE);
567 DIE *DwarfDebug::createScopeChildrenDIE(DwarfCompileUnit *TheCU,
569 SmallVectorImpl<DIE *> &Children) {
570 DIE *ObjectPointer = NULL;
572 // Collect arguments for current function.
573 if (LScopes.isCurrentFunctionScope(Scope)) {
574 for (DbgVariable *ArgDV : CurrentFnArguments)
577 TheCU->constructVariableDIE(*ArgDV, Scope->isAbstractScope())) {
578 Children.push_back(Arg);
579 if (ArgDV->isObjectPointer())
583 // If this is a variadic function, add an unspecified parameter.
584 DISubprogram SP(Scope->getScopeNode());
585 DIArray FnArgs = SP.getType().getTypeArray();
586 if (FnArgs.getElement(FnArgs.getNumElements() - 1)
587 .isUnspecifiedParameter()) {
588 DIE *Ellipsis = new DIE(dwarf::DW_TAG_unspecified_parameters);
589 Children.push_back(Ellipsis);
593 // Collect lexical scope children first.
594 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
595 if (DIE *Variable = TheCU->constructVariableDIE(*DV,
596 Scope->isAbstractScope())) {
597 Children.push_back(Variable);
598 if (DV->isObjectPointer())
599 ObjectPointer = Variable;
601 for (LexicalScope *LS : Scope->getChildren())
602 if (DIE *Nested = constructScopeDIE(TheCU, LS))
603 Children.push_back(Nested);
604 return ObjectPointer;
607 // Construct a DIE for this scope.
608 DIE *DwarfDebug::constructScopeDIE(DwarfCompileUnit *TheCU,
609 LexicalScope *Scope) {
610 if (!Scope || !Scope->getScopeNode())
613 DIScope DS(Scope->getScopeNode());
615 SmallVector<DIE *, 8> Children;
616 DIE *ObjectPointer = NULL;
617 bool ChildrenCreated = false;
619 // We try to create the scope DIE first, then the children DIEs. This will
620 // avoid creating un-used children then removing them later when we find out
621 // the scope DIE is null.
622 DIE *ScopeDIE = NULL;
623 if (Scope->getInlinedAt())
624 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
625 else if (DS.isSubprogram()) {
626 ProcessedSPNodes.insert(DS);
627 if (Scope->isAbstractScope()) {
628 ScopeDIE = TheCU->getDIE(DS);
629 // Note down abstract DIE.
631 AbstractSPDies.insert(std::make_pair(DS, ScopeDIE));
633 ScopeDIE = updateSubprogramScopeDIE(TheCU, DISubprogram(DS));
635 // Early exit when we know the scope DIE is going to be null.
636 if (isLexicalScopeDIENull(Scope))
639 // We create children here when we know the scope DIE is not going to be
640 // null and the children will be added to the scope DIE.
641 ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
642 ChildrenCreated = true;
644 // There is no need to emit empty lexical block DIE.
645 std::pair<ImportedEntityMap::const_iterator,
646 ImportedEntityMap::const_iterator> Range =
648 ScopesWithImportedEntities.begin(),
649 ScopesWithImportedEntities.end(),
650 std::pair<const MDNode *, const MDNode *>(DS, (const MDNode *)0),
652 if (Children.empty() && Range.first == Range.second)
654 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
655 assert(ScopeDIE && "Scope DIE should not be null.");
656 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
658 constructImportedEntityDIE(TheCU, i->second, ScopeDIE);
662 assert(Children.empty() &&
663 "We create children only when the scope DIE is not null.");
666 if (!ChildrenCreated)
667 // We create children when the scope DIE is not null.
668 ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
671 for (DIE *I : Children)
672 ScopeDIE->addChild(I);
674 if (DS.isSubprogram() && ObjectPointer != NULL)
675 TheCU->addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, ObjectPointer);
680 void DwarfDebug::addGnuPubAttributes(DwarfUnit *U, DIE *D) const {
681 if (!GenerateGnuPubSections)
684 U->addFlag(D, dwarf::DW_AT_GNU_pubnames);
687 // Create new DwarfCompileUnit for the given metadata node with tag
688 // DW_TAG_compile_unit.
689 DwarfCompileUnit *DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
690 StringRef FN = DIUnit.getFilename();
691 CompilationDir = DIUnit.getDirectory();
693 DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
694 DwarfCompileUnit *NewCU = new DwarfCompileUnit(
695 InfoHolder.getUnits().size(), Die, DIUnit, Asm, this, &InfoHolder);
696 InfoHolder.addUnit(NewCU);
698 // LTO with assembly output shares a single line table amongst multiple CUs.
699 // To avoid the compilation directory being ambiguous, let the line table
700 // explicitly describe the directory of all files, never relying on the
701 // compilation directory.
702 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
703 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
704 NewCU->getUniqueID(), CompilationDir);
706 NewCU->addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
707 NewCU->addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
708 DIUnit.getLanguage());
709 NewCU->addString(Die, dwarf::DW_AT_name, FN);
711 if (!useSplitDwarf()) {
712 NewCU->initStmtList(DwarfLineSectionSym);
714 // If we're using split dwarf the compilation dir is going to be in the
715 // skeleton CU and so we don't need to duplicate it here.
716 if (!CompilationDir.empty())
717 NewCU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
719 addGnuPubAttributes(NewCU, Die);
722 if (DIUnit.isOptimized())
723 NewCU->addFlag(Die, dwarf::DW_AT_APPLE_optimized);
725 StringRef Flags = DIUnit.getFlags();
727 NewCU->addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
729 if (unsigned RVer = DIUnit.getRunTimeVersion())
730 NewCU->addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
731 dwarf::DW_FORM_data1, RVer);
736 if (useSplitDwarf()) {
737 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
738 DwarfInfoDWOSectionSym);
739 NewCU->setSkeleton(constructSkeletonCU(NewCU));
741 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
742 DwarfInfoSectionSym);
744 CUMap.insert(std::make_pair(DIUnit, NewCU));
745 CUDieMap.insert(std::make_pair(Die, NewCU));
749 // Construct subprogram DIE.
750 void DwarfDebug::constructSubprogramDIE(DwarfCompileUnit *TheCU,
752 // FIXME: We should only call this routine once, however, during LTO if a
753 // program is defined in multiple CUs we could end up calling it out of
754 // beginModule as we walk the CUs.
756 DwarfCompileUnit *&CURef = SPMap[N];
762 if (!SP.isDefinition())
763 // This is a method declaration which will be handled while constructing
767 DIE *SubprogramDie = TheCU->getOrCreateSubprogramDIE(SP);
769 // Expose as a global name.
770 TheCU->addGlobalName(SP.getName(), SubprogramDie, resolve(SP.getContext()));
773 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
775 DIImportedEntity Module(N);
776 assert(Module.Verify());
777 if (DIE *D = TheCU->getOrCreateContextDIE(Module.getContext()))
778 constructImportedEntityDIE(TheCU, Module, D);
781 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
782 const MDNode *N, DIE *Context) {
783 DIImportedEntity Module(N);
784 assert(Module.Verify());
785 return constructImportedEntityDIE(TheCU, Module, Context);
788 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
789 const DIImportedEntity &Module,
791 assert(Module.Verify() &&
792 "Use one of the MDNode * overloads to handle invalid metadata");
793 assert(Context && "Should always have a context for an imported_module");
794 DIE *IMDie = new DIE(Module.getTag());
795 TheCU->insertDIE(Module, IMDie);
797 DIDescriptor Entity = resolve(Module.getEntity());
798 if (Entity.isNameSpace())
799 EntityDie = TheCU->getOrCreateNameSpace(DINameSpace(Entity));
800 else if (Entity.isSubprogram())
801 EntityDie = TheCU->getOrCreateSubprogramDIE(DISubprogram(Entity));
802 else if (Entity.isType())
803 EntityDie = TheCU->getOrCreateTypeDIE(DIType(Entity));
805 EntityDie = TheCU->getDIE(Entity);
806 TheCU->addSourceLine(IMDie, Module.getLineNumber(),
807 Module.getContext().getFilename(),
808 Module.getContext().getDirectory());
809 TheCU->addDIEEntry(IMDie, dwarf::DW_AT_import, EntityDie);
810 StringRef Name = Module.getName();
812 TheCU->addString(IMDie, dwarf::DW_AT_name, Name);
813 Context->addChild(IMDie);
816 // Emit all Dwarf sections that should come prior to the content. Create
817 // global DIEs and emit initial debug info sections. This is invoked by
818 // the target AsmPrinter.
819 void DwarfDebug::beginModule() {
820 if (DisableDebugInfoPrinting)
823 const Module *M = MMI->getModule();
825 // If module has named metadata anchors then use them, otherwise scan the
826 // module using debug info finder to collect debug info.
827 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
830 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
832 // Emit initial sections so we can reference labels later.
835 SingleCU = CU_Nodes->getNumOperands() == 1;
837 for (MDNode *N : CU_Nodes->operands()) {
838 DICompileUnit CUNode(N);
839 DwarfCompileUnit *CU = constructDwarfCompileUnit(CUNode);
840 DIArray ImportedEntities = CUNode.getImportedEntities();
841 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
842 ScopesWithImportedEntities.push_back(std::make_pair(
843 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
844 ImportedEntities.getElement(i)));
845 std::sort(ScopesWithImportedEntities.begin(),
846 ScopesWithImportedEntities.end(), less_first());
847 DIArray GVs = CUNode.getGlobalVariables();
848 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
849 CU->createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
850 DIArray SPs = CUNode.getSubprograms();
851 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
852 constructSubprogramDIE(CU, SPs.getElement(i));
853 DIArray EnumTypes = CUNode.getEnumTypes();
854 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
855 CU->getOrCreateTypeDIE(EnumTypes.getElement(i));
856 DIArray RetainedTypes = CUNode.getRetainedTypes();
857 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
858 DIType Ty(RetainedTypes.getElement(i));
859 // The retained types array by design contains pointers to
860 // MDNodes rather than DIRefs. Unique them here.
861 DIType UniqueTy(resolve(Ty.getRef()));
862 CU->getOrCreateTypeDIE(UniqueTy);
864 // Emit imported_modules last so that the relevant context is already
866 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
867 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
870 // Tell MMI that we have debug info.
871 MMI->setDebugInfoAvailability(true);
873 // Prime section data.
874 SectionMap[Asm->getObjFileLowering().getTextSection()];
877 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
878 void DwarfDebug::computeInlinedDIEs() {
879 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
880 for (DIE *ISP : InlinedSubprogramDIEs)
881 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
883 for (const auto &AI : AbstractSPDies) {
884 DIE *ISP = AI.second;
885 if (InlinedSubprogramDIEs.count(ISP))
887 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
891 // Collect info for variables that were optimized out.
892 void DwarfDebug::collectDeadVariables() {
893 const Module *M = MMI->getModule();
895 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
896 for (MDNode *N : CU_Nodes->operands()) {
897 DICompileUnit TheCU(N);
898 DIArray Subprograms = TheCU.getSubprograms();
899 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
900 DISubprogram SP(Subprograms.getElement(i));
901 if (ProcessedSPNodes.count(SP) != 0)
903 if (!SP.isSubprogram())
905 if (!SP.isDefinition())
907 DIArray Variables = SP.getVariables();
908 if (Variables.getNumElements() == 0)
911 // Construct subprogram DIE and add variables DIEs.
912 DwarfCompileUnit *SPCU =
913 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
914 assert(SPCU && "Unable to find Compile Unit!");
915 // FIXME: See the comment in constructSubprogramDIE about duplicate
917 constructSubprogramDIE(SPCU, SP);
918 DIE *SPDIE = SPCU->getDIE(SP);
919 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
920 DIVariable DV(Variables.getElement(vi));
921 if (!DV.isVariable())
923 DbgVariable NewVar(DV, NULL, this);
924 if (DIE *VariableDIE = SPCU->constructVariableDIE(NewVar, false))
925 SPDIE->addChild(VariableDIE);
932 void DwarfDebug::finalizeModuleInfo() {
933 // Collect info for variables that were optimized out.
934 collectDeadVariables();
936 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
937 computeInlinedDIEs();
939 // Handle anything that needs to be done on a per-unit basis after
940 // all other generation.
941 for (DwarfUnit *TheU : getUnits()) {
942 // Emit DW_AT_containing_type attribute to connect types with their
943 // vtable holding type.
944 TheU->constructContainingTypeDIEs();
946 // Add CU specific attributes if we need to add any.
947 if (TheU->getUnitDie()->getTag() == dwarf::DW_TAG_compile_unit) {
948 // If we're splitting the dwarf out now that we've got the entire
949 // CU then add the dwo id to it.
950 DwarfCompileUnit *SkCU =
951 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
952 if (useSplitDwarf()) {
953 // Emit a unique identifier for this CU.
954 uint64_t ID = DIEHash(Asm).computeCUSignature(*TheU->getUnitDie());
955 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
956 dwarf::DW_FORM_data8, ID);
957 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
958 dwarf::DW_FORM_data8, ID);
960 // We don't keep track of which addresses are used in which CU so this
961 // is a bit pessimistic under LTO.
962 if (!InfoHolder.getAddrPool()->empty())
963 addSectionLabel(Asm, SkCU, SkCU->getUnitDie(),
964 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
965 DwarfAddrSectionSym);
966 if (!TheU->getRangeLists().empty())
967 addSectionLabel(Asm, SkCU, SkCU->getUnitDie(),
968 dwarf::DW_AT_GNU_ranges_base,
969 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
972 // If we have code split among multiple sections or non-contiguous
973 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
974 // remain in the .o file, otherwise add a DW_AT_low_pc.
975 // FIXME: We should use ranges allow reordering of code ala
976 // .subsections_via_symbols in mach-o. This would mean turning on
977 // ranges for all subprogram DIEs for mach-o.
978 DwarfCompileUnit *U = SkCU ? SkCU : static_cast<DwarfCompileUnit *>(TheU);
979 unsigned NumRanges = TheU->getRanges().size();
982 addSectionLabel(Asm, U, U->getUnitDie(), dwarf::DW_AT_ranges,
983 Asm->GetTempSymbol("cu_ranges", U->getUniqueID()),
984 DwarfDebugRangeSectionSym);
986 // A DW_AT_low_pc attribute may also be specified in combination with
987 // DW_AT_ranges to specify the default base address for use in
988 // location lists (see Section 2.6.2) and range lists (see Section
990 U->addUInt(U->getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
993 RangeSpan &Range = TheU->getRanges().back();
994 U->addLocalLabelAddress(U->getUnitDie(), dwarf::DW_AT_low_pc,
996 U->addLabelDelta(U->getUnitDie(), dwarf::DW_AT_high_pc,
997 Range.getEnd(), Range.getStart());
1003 // Compute DIE offsets and sizes.
1004 InfoHolder.computeSizeAndOffsets();
1005 if (useSplitDwarf())
1006 SkeletonHolder.computeSizeAndOffsets();
1009 void DwarfDebug::endSections() {
1010 // Filter labels by section.
1011 for (const SymbolCU &SCU : ArangeLabels) {
1012 if (SCU.Sym->isInSection()) {
1013 // Make a note of this symbol and it's section.
1014 const MCSection *Section = &SCU.Sym->getSection();
1015 if (!Section->getKind().isMetadata())
1016 SectionMap[Section].push_back(SCU);
1018 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1019 // appear in the output. This sucks as we rely on sections to build
1020 // arange spans. We can do it without, but it's icky.
1021 SectionMap[NULL].push_back(SCU);
1025 // Build a list of sections used.
1026 std::vector<const MCSection *> Sections;
1027 for (const auto &it : SectionMap) {
1028 const MCSection *Section = it.first;
1029 Sections.push_back(Section);
1032 // Sort the sections into order.
1033 // This is only done to ensure consistent output order across different runs.
1034 std::sort(Sections.begin(), Sections.end(), SectionSort);
1036 // Add terminating symbols for each section.
1037 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1038 const MCSection *Section = Sections[ID];
1039 MCSymbol *Sym = NULL;
1042 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1043 // if we know the section name up-front. For user-created sections, the
1044 // resulting label may not be valid to use as a label. (section names can
1045 // use a greater set of characters on some systems)
1046 Sym = Asm->GetTempSymbol("debug_end", ID);
1047 Asm->OutStreamer.SwitchSection(Section);
1048 Asm->OutStreamer.EmitLabel(Sym);
1051 // Insert a final terminator.
1052 SectionMap[Section].push_back(SymbolCU(NULL, Sym));
1056 // Emit all Dwarf sections that should come after the content.
1057 void DwarfDebug::endModule() {
1064 // End any existing sections.
1065 // TODO: Does this need to happen?
1068 // Finalize the debug info for the module.
1069 finalizeModuleInfo();
1073 // Emit all the DIEs into a debug info section.
1076 // Corresponding abbreviations into a abbrev section.
1077 emitAbbreviations();
1079 // Emit info into a debug loc section.
1082 // Emit info into a debug aranges section.
1083 if (GenerateARangeSection)
1086 // Emit info into a debug ranges section.
1089 if (useSplitDwarf()) {
1092 emitDebugAbbrevDWO();
1094 // Emit DWO addresses.
1095 InfoHolder.emitAddresses(Asm->getObjFileLowering().getDwarfAddrSection());
1098 // Emit info into the dwarf accelerator table sections.
1099 if (useDwarfAccelTables()) {
1102 emitAccelNamespaces();
1106 // Emit the pubnames and pubtypes sections if requested.
1107 if (HasDwarfPubSections) {
1108 emitDebugPubNames(GenerateGnuPubSections);
1109 emitDebugPubTypes(GenerateGnuPubSections);
1115 // Reset these for the next Module if we have one.
1119 // Find abstract variable, if any, associated with Var.
1120 DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
1121 DebugLoc ScopeLoc) {
1122 LLVMContext &Ctx = DV->getContext();
1123 // More then one inlined variable corresponds to one abstract variable.
1124 DIVariable Var = cleanseInlinedVariable(DV, Ctx);
1125 DbgVariable *AbsDbgVariable = AbstractVariables.lookup(Var);
1127 return AbsDbgVariable;
1129 LexicalScope *Scope = LScopes.findAbstractScope(ScopeLoc.getScope(Ctx));
1133 AbsDbgVariable = new DbgVariable(Var, NULL, this);
1134 addScopeVariable(Scope, AbsDbgVariable);
1135 AbstractVariables[Var] = AbsDbgVariable;
1136 return AbsDbgVariable;
1139 // If Var is a current function argument then add it to CurrentFnArguments list.
1140 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1141 if (!LScopes.isCurrentFunctionScope(Scope))
1143 DIVariable DV = Var->getVariable();
1144 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1146 unsigned ArgNo = DV.getArgNumber();
1150 size_t Size = CurrentFnArguments.size();
1152 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1153 // llvm::Function argument size is not good indicator of how many
1154 // arguments does the function have at source level.
1156 CurrentFnArguments.resize(ArgNo * 2);
1157 CurrentFnArguments[ArgNo - 1] = Var;
1161 // Collect variable information from side table maintained by MMI.
1162 void DwarfDebug::collectVariableInfoFromMMITable(
1163 SmallPtrSet<const MDNode *, 16> &Processed) {
1164 for (const auto &VI : MMI->getVariableDbgInfo()) {
1167 Processed.insert(VI.Var);
1168 DIVariable DV(VI.Var);
1169 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1171 // If variable scope is not found then skip this variable.
1175 DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VI.Loc);
1176 DbgVariable *RegVar = new DbgVariable(DV, AbsDbgVariable, this);
1177 RegVar->setFrameIndex(VI.Slot);
1178 if (!addCurrentFnArgument(RegVar, Scope))
1179 addScopeVariable(Scope, RegVar);
1181 AbsDbgVariable->setFrameIndex(VI.Slot);
1185 // Return true if debug value, encoded by DBG_VALUE instruction, is in a
1187 static bool isDbgValueInDefinedReg(const MachineInstr *MI) {
1188 assert(MI->isDebugValue() && "Invalid DBG_VALUE machine instruction!");
1189 return MI->getNumOperands() == 3 && MI->getOperand(0).isReg() &&
1190 MI->getOperand(0).getReg() &&
1191 (MI->getOperand(1).isImm() ||
1192 (MI->getOperand(1).isReg() && MI->getOperand(1).getReg() == 0U));
1195 // Get .debug_loc entry for the instruction range starting at MI.
1196 static DebugLocEntry getDebugLocEntry(AsmPrinter *Asm,
1197 const MCSymbol *FLabel,
1198 const MCSymbol *SLabel,
1199 const MachineInstr *MI,
1200 DwarfCompileUnit *Unit) {
1201 const MDNode *Var = MI->getOperand(MI->getNumOperands() - 1).getMetadata();
1203 assert(MI->getNumOperands() == 3);
1204 if (MI->getOperand(0).isReg()) {
1205 MachineLocation MLoc;
1206 // If the second operand is an immediate, this is a
1207 // register-indirect address.
1208 if (!MI->getOperand(1).isImm())
1209 MLoc.set(MI->getOperand(0).getReg());
1211 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1212 return DebugLocEntry(FLabel, SLabel, MLoc, Var, Unit);
1214 if (MI->getOperand(0).isImm())
1215 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getImm(), Unit);
1216 if (MI->getOperand(0).isFPImm())
1217 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getFPImm(), Unit);
1218 if (MI->getOperand(0).isCImm())
1219 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getCImm(), Unit);
1221 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1224 // Find variables for each lexical scope.
1226 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1228 // Grab the variable info that was squirreled away in the MMI side-table.
1229 collectVariableInfoFromMMITable(Processed);
1231 for (const MDNode *Var : UserVariables) {
1232 if (Processed.count(Var))
1235 // History contains relevant DBG_VALUE instructions for Var and instructions
1237 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1238 if (History.empty())
1240 const MachineInstr *MInsn = History.front();
1243 LexicalScope *Scope = NULL;
1244 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1245 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1246 Scope = LScopes.getCurrentFunctionScope();
1247 else if (MDNode *IA = DV.getInlinedAt())
1248 Scope = LScopes.findInlinedScope(DebugLoc::getFromDILocation(IA));
1250 Scope = LScopes.findLexicalScope(cast<MDNode>(DV->getOperand(1)));
1251 // If variable scope is not found then skip this variable.
1255 Processed.insert(DV);
1256 assert(MInsn->isDebugValue() && "History must begin with debug value");
1257 DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
1258 DbgVariable *RegVar = new DbgVariable(DV, AbsVar, this);
1259 if (!addCurrentFnArgument(RegVar, Scope))
1260 addScopeVariable(Scope, RegVar);
1262 AbsVar->setMInsn(MInsn);
1264 // Simplify ranges that are fully coalesced.
1265 if (History.size() <= 1 ||
1266 (History.size() == 2 && MInsn->isIdenticalTo(History.back()))) {
1267 RegVar->setMInsn(MInsn);
1271 // Handle multiple DBG_VALUE instructions describing one variable.
1272 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1274 SmallVector<DebugLocEntry, 4> DebugLoc;
1275 for (SmallVectorImpl<const MachineInstr *>::const_iterator
1276 HI = History.begin(),
1279 const MachineInstr *Begin = *HI;
1280 assert(Begin->isDebugValue() && "Invalid History entry");
1282 // Check if DBG_VALUE is truncating a range.
1283 if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1284 !Begin->getOperand(0).getReg())
1287 // Compute the range for a register location.
1288 const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
1289 const MCSymbol *SLabel = 0;
1292 // If Begin is the last instruction in History then its value is valid
1293 // until the end of the function.
1294 SLabel = FunctionEndSym;
1296 const MachineInstr *End = HI[1];
1297 DEBUG(dbgs() << "DotDebugLoc Pair:\n"
1298 << "\t" << *Begin << "\t" << *End << "\n");
1299 if (End->isDebugValue())
1300 SLabel = getLabelBeforeInsn(End);
1302 // End is a normal instruction clobbering the range.
1303 SLabel = getLabelAfterInsn(End);
1304 assert(SLabel && "Forgot label after clobber instruction");
1309 // The value is valid until the next DBG_VALUE or clobber.
1310 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1311 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1312 DebugLocEntry Loc = getDebugLocEntry(Asm, FLabel, SLabel, Begin, TheCU);
1313 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc))
1314 DebugLoc.push_back(std::move(Loc));
1316 DotDebugLocEntries.push_back(std::move(DebugLoc));
1319 // Collect info for variables that were optimized out.
1320 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1321 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1322 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1323 DIVariable DV(Variables.getElement(i));
1324 if (!DV || !DV.isVariable() || !Processed.insert(DV))
1326 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
1327 addScopeVariable(Scope, new DbgVariable(DV, NULL, this));
1331 // Return Label preceding the instruction.
1332 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1333 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1334 assert(Label && "Didn't insert label before instruction");
1338 // Return Label immediately following the instruction.
1339 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1340 return LabelsAfterInsn.lookup(MI);
1343 // Process beginning of an instruction.
1344 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1347 // Check if source location changes, but ignore DBG_VALUE locations.
1348 if (!MI->isDebugValue()) {
1349 DebugLoc DL = MI->getDebugLoc();
1350 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1353 if (DL == PrologEndLoc) {
1354 Flags |= DWARF2_FLAG_PROLOGUE_END;
1355 PrologEndLoc = DebugLoc();
1357 if (PrologEndLoc.isUnknown())
1358 Flags |= DWARF2_FLAG_IS_STMT;
1360 if (!DL.isUnknown()) {
1361 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1362 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1364 recordSourceLine(0, 0, 0, 0);
1368 // Insert labels where requested.
1369 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1370 LabelsBeforeInsn.find(MI);
1373 if (I == LabelsBeforeInsn.end())
1376 // Label already assigned.
1381 PrevLabel = MMI->getContext().CreateTempSymbol();
1382 Asm->OutStreamer.EmitLabel(PrevLabel);
1384 I->second = PrevLabel;
1387 // Process end of an instruction.
1388 void DwarfDebug::endInstruction() {
1390 // Don't create a new label after DBG_VALUE instructions.
1391 // They don't generate code.
1392 if (!CurMI->isDebugValue())
1395 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1396 LabelsAfterInsn.find(CurMI);
1400 if (I == LabelsAfterInsn.end())
1403 // Label already assigned.
1407 // We need a label after this instruction.
1409 PrevLabel = MMI->getContext().CreateTempSymbol();
1410 Asm->OutStreamer.EmitLabel(PrevLabel);
1412 I->second = PrevLabel;
1415 // Each LexicalScope has first instruction and last instruction to mark
1416 // beginning and end of a scope respectively. Create an inverse map that list
1417 // scopes starts (and ends) with an instruction. One instruction may start (or
1418 // end) multiple scopes. Ignore scopes that are not reachable.
1419 void DwarfDebug::identifyScopeMarkers() {
1420 SmallVector<LexicalScope *, 4> WorkList;
1421 WorkList.push_back(LScopes.getCurrentFunctionScope());
1422 while (!WorkList.empty()) {
1423 LexicalScope *S = WorkList.pop_back_val();
1425 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1426 if (!Children.empty())
1427 WorkList.append(Children.begin(), Children.end());
1429 if (S->isAbstractScope())
1432 for (const InsnRange &R : S->getRanges()) {
1433 assert(R.first && "InsnRange does not have first instruction!");
1434 assert(R.second && "InsnRange does not have second instruction!");
1435 requestLabelBeforeInsn(R.first);
1436 requestLabelAfterInsn(R.second);
1441 // Gather pre-function debug information. Assumes being called immediately
1442 // after the function entry point has been emitted.
1443 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1446 // If there's no debug info for the function we're not going to do anything.
1447 if (!MMI->hasDebugInfo())
1450 // Grab the lexical scopes for the function, if we don't have any of those
1451 // then we're not going to be able to do anything.
1452 LScopes.initialize(*MF);
1453 if (LScopes.empty())
1456 assert(UserVariables.empty() && DbgValues.empty() && "Maps weren't cleaned");
1458 // Make sure that each lexical scope will have a begin/end label.
1459 identifyScopeMarkers();
1461 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1462 // belongs to so that we add to the correct per-cu line table in the
1464 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1465 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1466 assert(TheCU && "Unable to find compile unit!");
1467 if (Asm->OutStreamer.hasRawTextSupport())
1468 // Use a single line table if we are generating assembly.
1469 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1471 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1473 // Emit a label for the function so that we have a beginning address.
1474 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1475 // Assumes in correct section after the entry point.
1476 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1478 const TargetRegisterInfo *TRI = Asm->TM.getRegisterInfo();
1479 // LiveUserVar - Map physreg numbers to the MDNode they contain.
1480 std::vector<const MDNode *> LiveUserVar(TRI->getNumRegs());
1482 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); I != E;
1484 bool AtBlockEntry = true;
1485 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
1487 const MachineInstr *MI = II;
1489 if (MI->isDebugValue()) {
1490 assert(MI->getNumOperands() > 1 && "Invalid machine instruction!");
1492 // Keep track of user variables.
1494 MI->getOperand(MI->getNumOperands() - 1).getMetadata();
1496 // Variable is in a register, we need to check for clobbers.
1497 if (isDbgValueInDefinedReg(MI))
1498 LiveUserVar[MI->getOperand(0).getReg()] = Var;
1500 // Check the history of this variable.
1501 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1502 if (History.empty()) {
1503 UserVariables.push_back(Var);
1504 // The first mention of a function argument gets the FunctionBeginSym
1505 // label, so arguments are visible when breaking at function entry.
1507 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1508 getDISubprogram(DV.getContext()).describes(MF->getFunction()))
1509 LabelsBeforeInsn[MI] = FunctionBeginSym;
1511 // We have seen this variable before. Try to coalesce DBG_VALUEs.
1512 const MachineInstr *Prev = History.back();
1513 if (Prev->isDebugValue()) {
1514 // Coalesce identical entries at the end of History.
1515 if (History.size() >= 2 &&
1516 Prev->isIdenticalTo(History[History.size() - 2])) {
1517 DEBUG(dbgs() << "Coalescing identical DBG_VALUE entries:\n"
1518 << "\t" << *Prev << "\t"
1519 << *History[History.size() - 2] << "\n");
1523 // Terminate old register assignments that don't reach MI;
1524 MachineFunction::const_iterator PrevMBB = Prev->getParent();
1525 if (PrevMBB != I && (!AtBlockEntry || std::next(PrevMBB) != I) &&
1526 isDbgValueInDefinedReg(Prev)) {
1527 // Previous register assignment needs to terminate at the end of
1529 MachineBasicBlock::const_iterator LastMI =
1530 PrevMBB->getLastNonDebugInstr();
1531 if (LastMI == PrevMBB->end()) {
1532 // Drop DBG_VALUE for empty range.
1533 DEBUG(dbgs() << "Dropping DBG_VALUE for empty range:\n"
1534 << "\t" << *Prev << "\n");
1536 } else if (std::next(PrevMBB) != PrevMBB->getParent()->end())
1537 // Terminate after LastMI.
1538 History.push_back(LastMI);
1542 History.push_back(MI);
1544 // Not a DBG_VALUE instruction.
1545 if (!MI->isPosition())
1546 AtBlockEntry = false;
1548 // First known non-DBG_VALUE and non-frame setup location marks
1549 // the beginning of the function body.
1550 if (!MI->getFlag(MachineInstr::FrameSetup) &&
1551 (PrologEndLoc.isUnknown() && !MI->getDebugLoc().isUnknown()))
1552 PrologEndLoc = MI->getDebugLoc();
1554 // Check if the instruction clobbers any registers with debug vars.
1555 for (const MachineOperand &MO : MI->operands()) {
1556 if (!MO.isReg() || !MO.isDef() || !MO.getReg())
1558 for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid();
1561 const MDNode *Var = LiveUserVar[Reg];
1564 // Reg is now clobbered.
1565 LiveUserVar[Reg] = 0;
1567 // Was MD last defined by a DBG_VALUE referring to Reg?
1568 DbgValueHistoryMap::iterator HistI = DbgValues.find(Var);
1569 if (HistI == DbgValues.end())
1571 SmallVectorImpl<const MachineInstr *> &History = HistI->second;
1572 if (History.empty())
1574 const MachineInstr *Prev = History.back();
1575 // Sanity-check: Register assignments are terminated at the end of
1577 if (!Prev->isDebugValue() || Prev->getParent() != MI->getParent())
1579 // Is the variable still in Reg?
1580 if (!isDbgValueInDefinedReg(Prev) ||
1581 Prev->getOperand(0).getReg() != Reg)
1583 // Var is clobbered. Make sure the next instruction gets a label.
1584 History.push_back(MI);
1591 for (auto &I : DbgValues) {
1592 SmallVectorImpl<const MachineInstr *> &History = I.second;
1593 if (History.empty())
1596 // Make sure the final register assignments are terminated.
1597 const MachineInstr *Prev = History.back();
1598 if (Prev->isDebugValue() && isDbgValueInDefinedReg(Prev)) {
1599 const MachineBasicBlock *PrevMBB = Prev->getParent();
1600 MachineBasicBlock::const_iterator LastMI =
1601 PrevMBB->getLastNonDebugInstr();
1602 if (LastMI == PrevMBB->end())
1603 // Drop DBG_VALUE for empty range.
1605 else if (PrevMBB != &PrevMBB->getParent()->back()) {
1606 // Terminate after LastMI.
1607 History.push_back(LastMI);
1610 // Request labels for the full history.
1611 for (const MachineInstr *MI : History) {
1612 if (MI->isDebugValue())
1613 requestLabelBeforeInsn(MI);
1615 requestLabelAfterInsn(MI);
1619 PrevInstLoc = DebugLoc();
1620 PrevLabel = FunctionBeginSym;
1622 // Record beginning of function.
1623 if (!PrologEndLoc.isUnknown()) {
1624 DebugLoc FnStartDL =
1625 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1627 FnStartDL.getLine(), FnStartDL.getCol(),
1628 FnStartDL.getScope(MF->getFunction()->getContext()),
1629 // We'd like to list the prologue as "not statements" but GDB behaves
1630 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1631 DWARF2_FLAG_IS_STMT);
1635 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1636 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1637 DIVariable DV = Var->getVariable();
1638 // Variables with positive arg numbers are parameters.
1639 if (unsigned ArgNum = DV.getArgNumber()) {
1640 // Keep all parameters in order at the start of the variable list to ensure
1641 // function types are correct (no out-of-order parameters)
1643 // This could be improved by only doing it for optimized builds (unoptimized
1644 // builds have the right order to begin with), searching from the back (this
1645 // would catch the unoptimized case quickly), or doing a binary search
1646 // rather than linear search.
1647 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1648 while (I != Vars.end()) {
1649 unsigned CurNum = (*I)->getVariable().getArgNumber();
1650 // A local (non-parameter) variable has been found, insert immediately
1654 // A later indexed parameter has been found, insert immediately before it.
1655 if (CurNum > ArgNum)
1659 Vars.insert(I, Var);
1663 Vars.push_back(Var);
1666 // Gather and emit post-function debug information.
1667 void DwarfDebug::endFunction(const MachineFunction *MF) {
1668 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1669 // though the beginFunction may not be called at all.
1670 // We should handle both cases.
1674 assert(CurFn == MF);
1677 if (!MMI->hasDebugInfo() || LScopes.empty()) {
1678 // If we don't have a lexical scope for this function then there will
1679 // be a hole in the range information. Keep note of this by setting the
1680 // previously used section to nullptr.
1681 PrevSection = nullptr;
1687 // Define end label for subprogram.
1688 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1689 // Assumes in correct section after the entry point.
1690 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1692 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1693 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1695 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1696 collectVariableInfo(ProcessedVars);
1698 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1699 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1700 assert(TheCU && "Unable to find compile unit!");
1702 // Construct abstract scopes.
1703 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1704 DISubprogram SP(AScope->getScopeNode());
1705 if (SP.isSubprogram()) {
1706 // Collect info for variables that were optimized out.
1707 DIArray Variables = SP.getVariables();
1708 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1709 DIVariable DV(Variables.getElement(i));
1710 if (!DV || !DV.isVariable() || !ProcessedVars.insert(DV))
1712 // Check that DbgVariable for DV wasn't created earlier, when
1713 // findAbstractVariable() was called for inlined instance of DV.
1714 LLVMContext &Ctx = DV->getContext();
1715 DIVariable CleanDV = cleanseInlinedVariable(DV, Ctx);
1716 if (AbstractVariables.lookup(CleanDV))
1718 if (LexicalScope *Scope = LScopes.findAbstractScope(DV.getContext()))
1719 addScopeVariable(Scope, new DbgVariable(DV, NULL, this));
1722 if (ProcessedSPNodes.count(AScope->getScopeNode()) == 0)
1723 constructScopeDIE(TheCU, AScope);
1726 DIE *CurFnDIE = constructScopeDIE(TheCU, FnScope);
1727 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1728 TheCU->addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1730 // Add the range of this function to the list of ranges for the CU.
1731 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1732 TheCU->addRange(std::move(Span));
1733 PrevSection = Asm->getCurrentSection();
1737 for (auto &I : ScopeVariables)
1738 DeleteContainerPointers(I.second);
1739 ScopeVariables.clear();
1740 DeleteContainerPointers(CurrentFnArguments);
1741 UserVariables.clear();
1743 AbstractVariables.clear();
1744 LabelsBeforeInsn.clear();
1745 LabelsAfterInsn.clear();
1750 // Register a source line with debug info. Returns the unique label that was
1751 // emitted and which provides correspondence to the source line list.
1752 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1757 unsigned Discriminator = 0;
1759 DIDescriptor Scope(S);
1761 if (Scope.isCompileUnit()) {
1762 DICompileUnit CU(S);
1763 Fn = CU.getFilename();
1764 Dir = CU.getDirectory();
1765 } else if (Scope.isFile()) {
1767 Fn = F.getFilename();
1768 Dir = F.getDirectory();
1769 } else if (Scope.isSubprogram()) {
1771 Fn = SP.getFilename();
1772 Dir = SP.getDirectory();
1773 } else if (Scope.isLexicalBlockFile()) {
1774 DILexicalBlockFile DBF(S);
1775 Fn = DBF.getFilename();
1776 Dir = DBF.getDirectory();
1777 } else if (Scope.isLexicalBlock()) {
1778 DILexicalBlock DB(S);
1779 Fn = DB.getFilename();
1780 Dir = DB.getDirectory();
1781 Discriminator = DB.getDiscriminator();
1783 llvm_unreachable("Unexpected scope info");
1785 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1786 Src = static_cast<DwarfCompileUnit *>(InfoHolder.getUnits()[CUID])
1787 ->getOrCreateSourceID(Fn, Dir);
1789 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1793 //===----------------------------------------------------------------------===//
1795 //===----------------------------------------------------------------------===//
1797 // Compute the size and offset of a DIE. The offset is relative to start of the
1798 // CU. It returns the offset after laying out the DIE.
1799 unsigned DwarfFile::computeSizeAndOffset(DIE *Die, unsigned Offset) {
1800 // Record the abbreviation.
1801 assignAbbrevNumber(Die->getAbbrev());
1803 // Get the abbreviation for this DIE.
1804 const DIEAbbrev &Abbrev = Die->getAbbrev();
1807 Die->setOffset(Offset);
1809 // Start the size with the size of abbreviation code.
1810 Offset += getULEB128Size(Die->getAbbrevNumber());
1812 const SmallVectorImpl<DIEValue *> &Values = Die->getValues();
1813 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1815 // Size the DIE attribute values.
1816 for (unsigned i = 0, N = Values.size(); i < N; ++i)
1817 // Size attribute value.
1818 Offset += Values[i]->SizeOf(Asm, AbbrevData[i].getForm());
1820 // Get the children.
1821 const std::vector<DIE *> &Children = Die->getChildren();
1823 // Size the DIE children if any.
1824 if (!Children.empty()) {
1825 assert(Abbrev.hasChildren() && "Children flag not set");
1827 for (DIE *Child : Children)
1828 Offset = computeSizeAndOffset(Child, Offset);
1830 // End of children marker.
1831 Offset += sizeof(int8_t);
1834 Die->setSize(Offset - Die->getOffset());
1838 // Compute the size and offset for each DIE.
1839 void DwarfFile::computeSizeAndOffsets() {
1840 // Offset from the first CU in the debug info section is 0 initially.
1841 unsigned SecOffset = 0;
1843 // Iterate over each compile unit and set the size and offsets for each
1844 // DIE within each compile unit. All offsets are CU relative.
1845 for (DwarfUnit *TheU : CUs) {
1846 TheU->setDebugInfoOffset(SecOffset);
1848 // CU-relative offset is reset to 0 here.
1849 unsigned Offset = sizeof(int32_t) + // Length of Unit Info
1850 TheU->getHeaderSize(); // Unit-specific headers
1852 // EndOffset here is CU-relative, after laying out
1853 // all of the CU DIE.
1854 unsigned EndOffset = computeSizeAndOffset(TheU->getUnitDie(), Offset);
1855 SecOffset += EndOffset;
1859 // Emit initial Dwarf sections with a label at the start of each one.
1860 void DwarfDebug::emitSectionLabels() {
1861 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1863 // Dwarf sections base addresses.
1864 DwarfInfoSectionSym =
1865 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1866 if (useSplitDwarf())
1867 DwarfInfoDWOSectionSym =
1868 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1869 DwarfAbbrevSectionSym =
1870 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1871 if (useSplitDwarf())
1872 DwarfAbbrevDWOSectionSym = emitSectionSym(
1873 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1874 if (GenerateARangeSection)
1875 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1877 DwarfLineSectionSym =
1878 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1879 if (GenerateGnuPubSections) {
1880 DwarfGnuPubNamesSectionSym =
1881 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1882 DwarfGnuPubTypesSectionSym =
1883 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1884 } else if (HasDwarfPubSections) {
1885 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1886 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1889 DwarfStrSectionSym =
1890 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1891 if (useSplitDwarf()) {
1892 DwarfStrDWOSectionSym =
1893 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1894 DwarfAddrSectionSym =
1895 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1896 DwarfDebugLocSectionSym =
1897 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1899 DwarfDebugLocSectionSym =
1900 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1901 DwarfDebugRangeSectionSym =
1902 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1905 // Recursively emits a debug information entry.
1906 void DwarfDebug::emitDIE(DIE *Die) {
1907 // Get the abbreviation for this DIE.
1908 const DIEAbbrev &Abbrev = Die->getAbbrev();
1910 // Emit the code (index) for the abbreviation.
1911 if (Asm->isVerbose())
1912 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1913 "] 0x" + Twine::utohexstr(Die->getOffset()) +
1914 ":0x" + Twine::utohexstr(Die->getSize()) + " " +
1915 dwarf::TagString(Abbrev.getTag()));
1916 Asm->EmitULEB128(Abbrev.getNumber());
1918 const SmallVectorImpl<DIEValue *> &Values = Die->getValues();
1919 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1921 // Emit the DIE attribute values.
1922 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1923 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1924 dwarf::Form Form = AbbrevData[i].getForm();
1925 assert(Form && "Too many attributes for DIE (check abbreviation)");
1927 if (Asm->isVerbose()) {
1928 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1929 if (Attr == dwarf::DW_AT_accessibility)
1930 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1931 cast<DIEInteger>(Values[i])->getValue()));
1934 // Emit an attribute using the defined form.
1935 Values[i]->EmitValue(Asm, Form);
1938 // Emit the DIE children if any.
1939 if (Abbrev.hasChildren()) {
1940 const std::vector<DIE *> &Children = Die->getChildren();
1942 for (DIE *Child : Children)
1945 Asm->OutStreamer.AddComment("End Of Children Mark");
1950 // Emit the various dwarf units to the unit section USection with
1951 // the abbreviations going into ASection.
1952 void DwarfFile::emitUnits(DwarfDebug *DD, const MCSymbol *ASectionSym) {
1953 for (DwarfUnit *TheU : CUs) {
1954 DIE *Die = TheU->getUnitDie();
1955 const MCSection *USection = TheU->getSection();
1956 Asm->OutStreamer.SwitchSection(USection);
1958 // Emit the compile units header.
1959 Asm->OutStreamer.EmitLabel(TheU->getLabelBegin());
1961 // Emit size of content not including length itself
1962 Asm->OutStreamer.AddComment("Length of Unit");
1963 Asm->EmitInt32(TheU->getHeaderSize() + Die->getSize());
1965 TheU->emitHeader(ASectionSym);
1968 Asm->OutStreamer.EmitLabel(TheU->getLabelEnd());
1972 // Emit the debug info section.
1973 void DwarfDebug::emitDebugInfo() {
1974 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1976 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1979 // Emit the abbreviation section.
1980 void DwarfDebug::emitAbbreviations() {
1981 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1983 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1986 void DwarfFile::emitAbbrevs(const MCSection *Section) {
1987 // Check to see if it is worth the effort.
1988 if (!Abbreviations.empty()) {
1989 // Start the debug abbrev section.
1990 Asm->OutStreamer.SwitchSection(Section);
1992 // For each abbrevation.
1993 for (const DIEAbbrev *Abbrev : Abbreviations) {
1994 // Emit the abbrevations code (base 1 index.)
1995 Asm->EmitULEB128(Abbrev->getNumber(), "Abbreviation Code");
1997 // Emit the abbreviations data.
2001 // Mark end of abbreviations.
2002 Asm->EmitULEB128(0, "EOM(3)");
2006 // Emit the last address of the section and the end of the line matrix.
2007 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
2008 // Define last address of section.
2009 Asm->OutStreamer.AddComment("Extended Op");
2012 Asm->OutStreamer.AddComment("Op size");
2013 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
2014 Asm->OutStreamer.AddComment("DW_LNE_set_address");
2015 Asm->EmitInt8(dwarf::DW_LNE_set_address);
2017 Asm->OutStreamer.AddComment("Section end label");
2019 Asm->OutStreamer.EmitSymbolValue(
2020 Asm->GetTempSymbol("section_end", SectionEnd),
2021 Asm->getDataLayout().getPointerSize());
2023 // Mark end of matrix.
2024 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
2030 // Emit visible names into a hashed accelerator table section.
2031 void DwarfDebug::emitAccelNames() {
2033 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2034 for (DwarfUnit *TheU : getUnits()) {
2035 for (const auto &GI : TheU->getAccelNames()) {
2036 StringRef Name = GI.getKey();
2037 for (const DIE *D : GI.second)
2038 AT.AddName(Name, D);
2042 AT.FinalizeTable(Asm, "Names");
2043 Asm->OutStreamer.SwitchSection(
2044 Asm->getObjFileLowering().getDwarfAccelNamesSection());
2045 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
2046 Asm->OutStreamer.EmitLabel(SectionBegin);
2048 // Emit the full data.
2049 AT.Emit(Asm, SectionBegin, &InfoHolder);
2052 // Emit objective C classes and categories into a hashed accelerator table
2054 void DwarfDebug::emitAccelObjC() {
2056 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2057 for (DwarfUnit *TheU : getUnits()) {
2058 for (const auto &GI : TheU->getAccelObjC()) {
2059 StringRef Name = GI.getKey();
2060 for (const DIE *D : GI.second)
2061 AT.AddName(Name, D);
2065 AT.FinalizeTable(Asm, "ObjC");
2066 Asm->OutStreamer.SwitchSection(
2067 Asm->getObjFileLowering().getDwarfAccelObjCSection());
2068 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
2069 Asm->OutStreamer.EmitLabel(SectionBegin);
2071 // Emit the full data.
2072 AT.Emit(Asm, SectionBegin, &InfoHolder);
2075 // Emit namespace dies into a hashed accelerator table.
2076 void DwarfDebug::emitAccelNamespaces() {
2078 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2079 for (DwarfUnit *TheU : getUnits()) {
2080 for (const auto &GI : TheU->getAccelNamespace()) {
2081 StringRef Name = GI.getKey();
2082 for (const DIE *D : GI.second)
2083 AT.AddName(Name, D);
2087 AT.FinalizeTable(Asm, "namespac");
2088 Asm->OutStreamer.SwitchSection(
2089 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
2090 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
2091 Asm->OutStreamer.EmitLabel(SectionBegin);
2093 // Emit the full data.
2094 AT.Emit(Asm, SectionBegin, &InfoHolder);
2097 // Emit type dies into a hashed accelerator table.
2098 void DwarfDebug::emitAccelTypes() {
2099 std::vector<DwarfAccelTable::Atom> Atoms;
2101 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2103 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2));
2105 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1));
2106 DwarfAccelTable AT(Atoms);
2107 for (DwarfUnit *TheU : getUnits()) {
2108 for (const auto &GI : TheU->getAccelTypes()) {
2109 StringRef Name = GI.getKey();
2110 for (const auto &DI : GI.second)
2111 AT.AddName(Name, DI.first, DI.second);
2115 AT.FinalizeTable(Asm, "types");
2116 Asm->OutStreamer.SwitchSection(
2117 Asm->getObjFileLowering().getDwarfAccelTypesSection());
2118 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
2119 Asm->OutStreamer.EmitLabel(SectionBegin);
2121 // Emit the full data.
2122 AT.Emit(Asm, SectionBegin, &InfoHolder);
2125 // Public name handling.
2126 // The format for the various pubnames:
2128 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
2129 // for the DIE that is named.
2131 // gnu pubnames - offset/index value/name tuples where the offset is the offset
2132 // into the CU and the index value is computed according to the type of value
2133 // for the DIE that is named.
2135 // For type units the offset is the offset of the skeleton DIE. For split dwarf
2136 // it's the offset within the debug_info/debug_types dwo section, however, the
2137 // reference in the pubname header doesn't change.
2139 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
2140 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
2142 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
2144 // We could have a specification DIE that has our most of our knowledge,
2145 // look for that now.
2146 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
2148 DIE *SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
2149 if (SpecDIE->findAttribute(dwarf::DW_AT_external))
2150 Linkage = dwarf::GIEL_EXTERNAL;
2151 } else if (Die->findAttribute(dwarf::DW_AT_external))
2152 Linkage = dwarf::GIEL_EXTERNAL;
2154 switch (Die->getTag()) {
2155 case dwarf::DW_TAG_class_type:
2156 case dwarf::DW_TAG_structure_type:
2157 case dwarf::DW_TAG_union_type:
2158 case dwarf::DW_TAG_enumeration_type:
2159 return dwarf::PubIndexEntryDescriptor(
2160 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
2161 ? dwarf::GIEL_STATIC
2162 : dwarf::GIEL_EXTERNAL);
2163 case dwarf::DW_TAG_typedef:
2164 case dwarf::DW_TAG_base_type:
2165 case dwarf::DW_TAG_subrange_type:
2166 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
2167 case dwarf::DW_TAG_namespace:
2168 return dwarf::GIEK_TYPE;
2169 case dwarf::DW_TAG_subprogram:
2170 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
2171 case dwarf::DW_TAG_constant:
2172 case dwarf::DW_TAG_variable:
2173 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
2174 case dwarf::DW_TAG_enumerator:
2175 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
2176 dwarf::GIEL_STATIC);
2178 return dwarf::GIEK_NONE;
2182 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
2184 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
2185 const MCSection *PSec =
2186 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
2187 : Asm->getObjFileLowering().getDwarfPubNamesSection();
2189 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
2192 void DwarfDebug::emitDebugPubSection(
2193 bool GnuStyle, const MCSection *PSec, StringRef Name,
2194 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
2195 for (const auto &NU : CUMap) {
2196 DwarfCompileUnit *TheU = NU.second;
2198 const auto &Globals = (TheU->*Accessor)();
2200 if (Globals.empty())
2203 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2205 unsigned ID = TheU->getUniqueID();
2207 // Start the dwarf pubnames section.
2208 Asm->OutStreamer.SwitchSection(PSec);
2211 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2212 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2213 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2214 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2216 Asm->OutStreamer.EmitLabel(BeginLabel);
2218 Asm->OutStreamer.AddComment("DWARF Version");
2219 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2221 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2222 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2224 Asm->OutStreamer.AddComment("Compilation Unit Length");
2225 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2227 // Emit the pubnames for this compilation unit.
2228 for (const auto &GI : Globals) {
2229 const char *Name = GI.getKeyData();
2230 const DIE *Entity = GI.second;
2232 Asm->OutStreamer.AddComment("DIE offset");
2233 Asm->EmitInt32(Entity->getOffset());
2236 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2237 Asm->OutStreamer.AddComment(
2238 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2239 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2240 Asm->EmitInt8(Desc.toBits());
2243 Asm->OutStreamer.AddComment("External Name");
2244 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2247 Asm->OutStreamer.AddComment("End Mark");
2249 Asm->OutStreamer.EmitLabel(EndLabel);
2253 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2254 const MCSection *PSec =
2255 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2256 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2258 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2261 // Emit strings into a string section.
2262 void DwarfFile::emitStrings(const MCSection *StrSection,
2263 const MCSection *OffsetSection = NULL,
2264 const MCSymbol *StrSecSym = NULL) {
2266 if (StringPool.empty())
2269 // Start the dwarf str section.
2270 Asm->OutStreamer.SwitchSection(StrSection);
2272 // Get all of the string pool entries and put them in an array by their ID so
2273 // we can sort them.
2274 SmallVector<std::pair<unsigned, const StrPool::value_type *>, 64 > Entries;
2276 for (const auto &I : StringPool)
2277 Entries.push_back(std::make_pair(I.second.second, &I));
2279 array_pod_sort(Entries.begin(), Entries.end());
2281 for (const auto &Entry : Entries) {
2282 // Emit a label for reference from debug information entries.
2283 Asm->OutStreamer.EmitLabel(Entry.second->getValue().first);
2285 // Emit the string itself with a terminating null byte.
2286 Asm->OutStreamer.EmitBytes(StringRef(Entry.second->getKeyData(),
2287 Entry.second->getKeyLength() + 1));
2290 // If we've got an offset section go ahead and emit that now as well.
2291 if (OffsetSection) {
2292 Asm->OutStreamer.SwitchSection(OffsetSection);
2293 unsigned offset = 0;
2294 unsigned size = 4; // FIXME: DWARF64 is 8.
2295 for (const auto &Entry : Entries) {
2296 Asm->OutStreamer.EmitIntValue(offset, size);
2297 offset += Entry.second->getKeyLength() + 1;
2302 // Emit addresses into the section given.
2303 void DwarfFile::emitAddresses(const MCSection *AddrSection) {
2305 if (AddressPool.empty())
2308 // Start the dwarf addr section.
2309 Asm->OutStreamer.SwitchSection(AddrSection);
2311 // Order the address pool entries by ID
2312 SmallVector<const MCExpr *, 64> Entries(AddressPool.size());
2314 for (const auto &I : AddressPool)
2315 Entries[I.second.Number] =
2317 ? Asm->getObjFileLowering().getDebugThreadLocalSymbol(I.first)
2318 : MCSymbolRefExpr::Create(I.first, Asm->OutContext);
2320 for (const MCExpr *Entry : Entries)
2321 Asm->OutStreamer.EmitValue(Entry, Asm->getDataLayout().getPointerSize());
2324 // Emit visible names into a debug str section.
2325 void DwarfDebug::emitDebugStr() {
2326 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2327 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2330 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2331 const DebugLocEntry &Entry) {
2332 DIVariable DV(Entry.getVariable());
2333 if (Entry.isInt()) {
2334 DIBasicType BTy(resolve(DV.getType()));
2335 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2336 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2337 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2338 Streamer.EmitSLEB128(Entry.getInt());
2340 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2341 Streamer.EmitULEB128(Entry.getInt());
2343 } else if (Entry.isLocation()) {
2344 MachineLocation Loc = Entry.getLoc();
2345 if (!DV.hasComplexAddress())
2347 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2349 // Complex address entry.
2350 unsigned N = DV.getNumAddrElements();
2352 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2353 if (Loc.getOffset()) {
2355 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2356 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2357 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2358 Streamer.EmitSLEB128(DV.getAddrElement(1));
2360 // If first address element is OpPlus then emit
2361 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2362 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2363 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2367 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2370 // Emit remaining complex address elements.
2371 for (; i < N; ++i) {
2372 uint64_t Element = DV.getAddrElement(i);
2373 if (Element == DIBuilder::OpPlus) {
2374 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2375 Streamer.EmitULEB128(DV.getAddrElement(++i));
2376 } else if (Element == DIBuilder::OpDeref) {
2378 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2380 llvm_unreachable("unknown Opcode found in complex address");
2384 // else ... ignore constant fp. There is not any good way to
2385 // to represent them here in dwarf.
2389 // Emit locations into the debug loc section.
2390 void DwarfDebug::emitDebugLoc() {
2391 // Start the dwarf loc section.
2392 Asm->OutStreamer.SwitchSection(
2393 useSplitDwarf() ? Asm->getObjFileLowering().getDwarfLocDWOSection()
2394 : Asm->getObjFileLowering().getDwarfLocSection());
2395 unsigned char Size = Asm->getDataLayout().getPointerSize();
2397 for (const auto &DebugLoc : DotDebugLocEntries) {
2398 Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_loc", index));
2399 for (const auto &Entry : DebugLoc) {
2400 // Set up the range. This range is relative to the entry point of the
2401 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2402 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2403 const DwarfCompileUnit *CU = Entry.getCU();
2404 if (useSplitDwarf()) {
2405 // Just always use start_length for now - at least that's one address
2406 // rather than two. We could get fancier and try to, say, reuse an
2407 // address we know we've emitted elsewhere (the start of the function?
2408 // The start of the CU or CU subrange that encloses this range?)
2409 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2410 unsigned idx = InfoHolder.getAddrPoolIndex(Entry.getBeginSym());
2411 Asm->EmitULEB128(idx);
2412 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2413 } else if (CU->getRanges().size() == 1) {
2414 // Grab the begin symbol from the first range as our base.
2415 const MCSymbol *Base = CU->getRanges()[0].getStart();
2416 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2417 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2419 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2420 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2422 Asm->OutStreamer.AddComment("Loc expr size");
2423 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2424 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2425 Asm->EmitLabelDifference(end, begin, 2);
2426 Asm->OutStreamer.EmitLabel(begin);
2428 APByteStreamer Streamer(*Asm);
2429 emitDebugLocEntry(Streamer, Entry);
2431 Asm->OutStreamer.EmitLabel(end);
2433 if (useSplitDwarf())
2434 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2436 Asm->OutStreamer.EmitIntValue(0, Size);
2437 Asm->OutStreamer.EmitIntValue(0, Size);
2444 const MCSymbol *Start, *End;
2447 // Emit a debug aranges section, containing a CU lookup for any
2448 // address we can tie back to a CU.
2449 void DwarfDebug::emitDebugARanges() {
2450 // Start the dwarf aranges section.
2451 Asm->OutStreamer.SwitchSection(
2452 Asm->getObjFileLowering().getDwarfARangesSection());
2454 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan> > SpansType;
2458 // Build a list of sections used.
2459 std::vector<const MCSection *> Sections;
2460 for (const auto &it : SectionMap) {
2461 const MCSection *Section = it.first;
2462 Sections.push_back(Section);
2465 // Sort the sections into order.
2466 // This is only done to ensure consistent output order across different runs.
2467 std::sort(Sections.begin(), Sections.end(), SectionSort);
2469 // Build a set of address spans, sorted by CU.
2470 for (const MCSection *Section : Sections) {
2471 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2472 if (List.size() < 2)
2475 // Sort the symbols by offset within the section.
2476 std::sort(List.begin(), List.end(),
2477 [&](const SymbolCU &A, const SymbolCU &B) {
2478 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2479 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2481 // Symbols with no order assigned should be placed at the end.
2482 // (e.g. section end labels)
2490 // If we have no section (e.g. common), just write out
2491 // individual spans for each symbol.
2492 if (Section == NULL) {
2493 for (const SymbolCU &Cur : List) {
2495 Span.Start = Cur.Sym;
2498 Spans[Cur.CU].push_back(Span);
2501 // Build spans between each label.
2502 const MCSymbol *StartSym = List[0].Sym;
2503 for (size_t n = 1, e = List.size(); n < e; n++) {
2504 const SymbolCU &Prev = List[n - 1];
2505 const SymbolCU &Cur = List[n];
2507 // Try and build the longest span we can within the same CU.
2508 if (Cur.CU != Prev.CU) {
2510 Span.Start = StartSym;
2512 Spans[Prev.CU].push_back(Span);
2519 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2521 // Build a list of CUs used.
2522 std::vector<DwarfCompileUnit *> CUs;
2523 for (const auto &it : Spans) {
2524 DwarfCompileUnit *CU = it.first;
2528 // Sort the CU list (again, to ensure consistent output order).
2529 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2530 return A->getUniqueID() < B->getUniqueID();
2533 // Emit an arange table for each CU we used.
2534 for (DwarfCompileUnit *CU : CUs) {
2535 std::vector<ArangeSpan> &List = Spans[CU];
2537 // Emit size of content not including length itself.
2538 unsigned ContentSize =
2539 sizeof(int16_t) + // DWARF ARange version number
2540 sizeof(int32_t) + // Offset of CU in the .debug_info section
2541 sizeof(int8_t) + // Pointer Size (in bytes)
2542 sizeof(int8_t); // Segment Size (in bytes)
2544 unsigned TupleSize = PtrSize * 2;
2546 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2548 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2550 ContentSize += Padding;
2551 ContentSize += (List.size() + 1) * TupleSize;
2553 // For each compile unit, write the list of spans it covers.
2554 Asm->OutStreamer.AddComment("Length of ARange Set");
2555 Asm->EmitInt32(ContentSize);
2556 Asm->OutStreamer.AddComment("DWARF Arange version number");
2557 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2558 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2559 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2560 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2561 Asm->EmitInt8(PtrSize);
2562 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2565 Asm->OutStreamer.EmitFill(Padding, 0xff);
2567 for (const ArangeSpan &Span : List) {
2568 Asm->EmitLabelReference(Span.Start, PtrSize);
2570 // Calculate the size as being from the span start to it's end.
2572 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2574 // For symbols without an end marker (e.g. common), we
2575 // write a single arange entry containing just that one symbol.
2576 uint64_t Size = SymSize[Span.Start];
2580 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2584 Asm->OutStreamer.AddComment("ARange terminator");
2585 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2586 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2590 // Emit visible names into a debug ranges section.
2591 void DwarfDebug::emitDebugRanges() {
2592 // Start the dwarf ranges section.
2593 Asm->OutStreamer.SwitchSection(
2594 Asm->getObjFileLowering().getDwarfRangesSection());
2596 // Size for our labels.
2597 unsigned char Size = Asm->getDataLayout().getPointerSize();
2599 // Grab the specific ranges for the compile units in the module.
2600 for (const auto &I : CUMap) {
2601 DwarfCompileUnit *TheCU = I.second;
2603 // Emit a symbol so we can find the beginning of our ranges.
2604 Asm->OutStreamer.EmitLabel(TheCU->getLabelRange());
2606 // Iterate over the misc ranges for the compile units in the module.
2607 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2608 // Emit our symbol so we can find the beginning of the range.
2609 Asm->OutStreamer.EmitLabel(List.getSym());
2611 for (const RangeSpan &Range : List.getRanges()) {
2612 const MCSymbol *Begin = Range.getStart();
2613 const MCSymbol *End = Range.getEnd();
2614 assert(Begin && "Range without a begin symbol?");
2615 assert(End && "Range without an end symbol?");
2616 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2617 Asm->OutStreamer.EmitSymbolValue(End, Size);
2620 // And terminate the list with two 0 values.
2621 Asm->OutStreamer.EmitIntValue(0, Size);
2622 Asm->OutStreamer.EmitIntValue(0, Size);
2625 // Now emit a range for the CU itself.
2626 if (TheCU->getRanges().size() > 1) {
2627 Asm->OutStreamer.EmitLabel(
2628 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2629 for (const RangeSpan &Range : TheCU->getRanges()) {
2630 const MCSymbol *Begin = Range.getStart();
2631 const MCSymbol *End = Range.getEnd();
2632 assert(Begin && "Range without a begin symbol?");
2633 assert(End && "Range without an end symbol?");
2634 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2635 Asm->OutStreamer.EmitSymbolValue(End, Size);
2637 // And terminate the list with two 0 values.
2638 Asm->OutStreamer.EmitIntValue(0, Size);
2639 Asm->OutStreamer.EmitIntValue(0, Size);
2644 // DWARF5 Experimental Separate Dwarf emitters.
2646 void DwarfDebug::initSkeletonUnit(const DwarfUnit *U, DIE *Die,
2648 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2649 U->getCUNode().getSplitDebugFilename());
2651 if (!CompilationDir.empty())
2652 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2654 addGnuPubAttributes(NewU, Die);
2656 SkeletonHolder.addUnit(NewU);
2659 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2660 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2661 // DW_AT_addr_base, DW_AT_ranges_base.
2662 DwarfCompileUnit *DwarfDebug::constructSkeletonCU(const DwarfCompileUnit *CU) {
2664 DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
2665 DwarfCompileUnit *NewCU = new DwarfCompileUnit(
2666 CU->getUniqueID(), Die, CU->getCUNode(), Asm, this, &SkeletonHolder);
2667 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2668 DwarfInfoSectionSym);
2670 NewCU->initStmtList(DwarfLineSectionSym);
2672 initSkeletonUnit(CU, Die, NewCU);
2677 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2679 DwarfTypeUnit *DwarfDebug::constructSkeletonTU(DwarfTypeUnit *TU) {
2680 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2681 *SkeletonHolder.getUnits()[TU->getCU().getUniqueID()]);
2683 DIE *Die = new DIE(dwarf::DW_TAG_type_unit);
2684 DwarfTypeUnit *NewTU =
2685 new DwarfTypeUnit(TU->getUniqueID(), Die, CU, Asm, this, &SkeletonHolder);
2686 NewTU->setTypeSignature(TU->getTypeSignature());
2687 NewTU->setType(NULL);
2689 Asm->getObjFileLowering().getDwarfTypesSection(TU->getTypeSignature()));
2691 initSkeletonUnit(TU, Die, NewTU);
2695 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2696 // compile units that would normally be in debug_info.
2697 void DwarfDebug::emitDebugInfoDWO() {
2698 assert(useSplitDwarf() && "No split dwarf debug info?");
2699 InfoHolder.emitUnits(this, nullptr);
2702 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2703 // abbreviations for the .debug_info.dwo section.
2704 void DwarfDebug::emitDebugAbbrevDWO() {
2705 assert(useSplitDwarf() && "No split dwarf?");
2706 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2709 void DwarfDebug::emitDebugLineDWO() {
2710 assert(useSplitDwarf() && "No split dwarf?");
2711 Asm->OutStreamer.SwitchSection(
2712 Asm->getObjFileLowering().getDwarfLineDWOSection());
2713 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2716 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2717 // string section and is identical in format to traditional .debug_str
2719 void DwarfDebug::emitDebugStrDWO() {
2720 assert(useSplitDwarf() && "No split dwarf?");
2721 const MCSection *OffSec =
2722 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2723 const MCSymbol *StrSym = DwarfStrSectionSym;
2724 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2728 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2729 if (!useSplitDwarf())
2732 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2733 return &SplitTypeUnitFileTable;
2736 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2737 StringRef Identifier, DIE *RefDie,
2738 DICompositeType CTy) {
2739 // Flag the type unit reference as a declaration so that if it contains
2740 // members (implicit special members, static data member definitions, member
2741 // declarations for definitions in this CU, etc) consumers don't get confused
2742 // and think this is a full definition.
2743 CU.addFlag(RefDie, dwarf::DW_AT_declaration);
2745 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2747 CU.addDIETypeSignature(RefDie, *TU);
2751 DIE *UnitDie = new DIE(dwarf::DW_TAG_type_unit);
2752 DwarfTypeUnit *NewTU =
2753 new DwarfTypeUnit(InfoHolder.getUnits().size(), UnitDie, CU, Asm, this,
2754 &InfoHolder, getDwoLineTable(CU));
2756 InfoHolder.addUnit(NewTU);
2758 NewTU->addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2762 Hash.update(Identifier);
2763 // ... take the least significant 8 bytes and return those. Our MD5
2764 // implementation always returns its results in little endian, swap bytes
2766 MD5::MD5Result Result;
2768 uint64_t Signature = *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2769 NewTU->setTypeSignature(Signature);
2770 if (useSplitDwarf())
2771 NewTU->setSkeleton(constructSkeletonTU(NewTU));
2773 CU.applyStmtList(*UnitDie);
2775 NewTU->setType(NewTU->createTypeDIE(CTy));
2779 ? Asm->getObjFileLowering().getDwarfTypesDWOSection(Signature)
2780 : Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2782 CU.addDIETypeSignature(RefDie, *NewTU);
2785 void DwarfDebug::attachLowHighPC(DwarfCompileUnit *Unit, DIE *D,
2786 MCSymbol *Begin, MCSymbol *End) {
2787 Unit->addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2788 if (DwarfVersion < 4)
2789 Unit->addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2791 Unit->addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);