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 #include "ByteStreamer.h"
15 #include "DwarfDebug.h"
18 #include "DwarfAccelTable.h"
19 #include "DwarfUnit.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/ADT/StringExtras.h"
23 #include "llvm/ADT/Triple.h"
24 #include "llvm/CodeGen/MachineFunction.h"
25 #include "llvm/CodeGen/MachineModuleInfo.h"
26 #include "llvm/IR/Constants.h"
27 #include "llvm/IR/DIBuilder.h"
28 #include "llvm/IR/DataLayout.h"
29 #include "llvm/IR/DebugInfo.h"
30 #include "llvm/IR/Instructions.h"
31 #include "llvm/IR/Module.h"
32 #include "llvm/IR/ValueHandle.h"
33 #include "llvm/MC/MCAsmInfo.h"
34 #include "llvm/MC/MCSection.h"
35 #include "llvm/MC/MCStreamer.h"
36 #include "llvm/MC/MCSymbol.h"
37 #include "llvm/Support/CommandLine.h"
38 #include "llvm/Support/Debug.h"
39 #include "llvm/Support/Dwarf.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/FormattedStream.h"
42 #include "llvm/Support/LEB128.h"
43 #include "llvm/Support/MD5.h"
44 #include "llvm/Support/Path.h"
45 #include "llvm/Support/Timer.h"
46 #include "llvm/Target/TargetFrameLowering.h"
47 #include "llvm/Target/TargetLoweringObjectFile.h"
48 #include "llvm/Target/TargetMachine.h"
49 #include "llvm/Target/TargetOptions.h"
50 #include "llvm/Target/TargetRegisterInfo.h"
53 #define DEBUG_TYPE "dwarfdebug"
56 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
57 cl::desc("Disable debug info printing"));
59 static cl::opt<bool> UnknownLocations(
60 "use-unknown-locations", cl::Hidden,
61 cl::desc("Make an absence of debug location information explicit."),
65 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
66 cl::desc("Generate GNU-style pubnames and pubtypes"),
69 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
71 cl::desc("Generate dwarf aranges"),
75 enum DefaultOnOff { Default, Enable, Disable };
78 static cl::opt<DefaultOnOff>
79 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
80 cl::desc("Output prototype dwarf accelerator tables."),
81 cl::values(clEnumVal(Default, "Default for platform"),
82 clEnumVal(Enable, "Enabled"),
83 clEnumVal(Disable, "Disabled"), clEnumValEnd),
86 static cl::opt<DefaultOnOff>
87 SplitDwarf("split-dwarf", cl::Hidden,
88 cl::desc("Output DWARF5 split debug info."),
89 cl::values(clEnumVal(Default, "Default for platform"),
90 clEnumVal(Enable, "Enabled"),
91 clEnumVal(Disable, "Disabled"), clEnumValEnd),
94 static cl::opt<DefaultOnOff>
95 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
96 cl::desc("Generate DWARF pubnames and pubtypes sections"),
97 cl::values(clEnumVal(Default, "Default for platform"),
98 clEnumVal(Enable, "Enabled"),
99 clEnumVal(Disable, "Disabled"), clEnumValEnd),
102 static cl::opt<unsigned>
103 DwarfVersionNumber("dwarf-version", cl::Hidden,
104 cl::desc("Generate DWARF for dwarf version."), cl::init(0));
106 static const char *const DWARFGroupName = "DWARF Emission";
107 static const char *const DbgTimerName = "DWARF Debug Writer";
109 //===----------------------------------------------------------------------===//
113 /// resolve - Look in the DwarfDebug map for the MDNode that
114 /// corresponds to the reference.
115 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
116 return DD->resolve(Ref);
119 bool DbgVariable::isBlockByrefVariable() const {
120 assert(Var.isVariable() && "Invalid complex DbgVariable!");
121 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
125 DIType DbgVariable::getType() const {
126 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
127 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
128 // addresses instead.
129 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
130 /* Byref variables, in Blocks, are declared by the programmer as
131 "SomeType VarName;", but the compiler creates a
132 __Block_byref_x_VarName struct, and gives the variable VarName
133 either the struct, or a pointer to the struct, as its type. This
134 is necessary for various behind-the-scenes things the compiler
135 needs to do with by-reference variables in blocks.
137 However, as far as the original *programmer* is concerned, the
138 variable should still have type 'SomeType', as originally declared.
140 The following function dives into the __Block_byref_x_VarName
141 struct to find the original type of the variable. This will be
142 passed back to the code generating the type for the Debug
143 Information Entry for the variable 'VarName'. 'VarName' will then
144 have the original type 'SomeType' in its debug information.
146 The original type 'SomeType' will be the type of the field named
147 'VarName' inside the __Block_byref_x_VarName struct.
149 NOTE: In order for this to not completely fail on the debugger
150 side, the Debug Information Entry for the variable VarName needs to
151 have a DW_AT_location that tells the debugger how to unwind through
152 the pointers and __Block_byref_x_VarName struct to find the actual
153 value of the variable. The function addBlockByrefType does this. */
155 uint16_t tag = Ty.getTag();
157 if (tag == dwarf::DW_TAG_pointer_type)
158 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
160 DIArray Elements = DICompositeType(subType).getTypeArray();
161 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
162 DIDerivedType DT(Elements.getElement(i));
163 if (getName() == DT.getName())
164 return (resolve(DT.getTypeDerivedFrom()));
170 } // end llvm namespace
172 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
173 : Asm(A), MMI(Asm->MMI), FirstCU(0), PrevLabel(NULL), GlobalRangeCount(0),
174 InfoHolder(A, "info_string", DIEValueAllocator),
175 UsedNonDefaultText(false),
176 SkeletonHolder(A, "skel_string", DIEValueAllocator) {
178 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = 0;
179 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = DwarfLineSectionSym = 0;
180 DwarfAddrSectionSym = 0;
181 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = 0;
182 FunctionBeginSym = FunctionEndSym = 0;
186 // Turn on accelerator tables for Darwin by default, pubnames by
187 // default for non-Darwin, and handle split dwarf.
188 bool IsDarwin = Triple(A->getTargetTriple()).isOSDarwin();
190 if (DwarfAccelTables == Default)
191 HasDwarfAccelTables = IsDarwin;
193 HasDwarfAccelTables = DwarfAccelTables == Enable;
195 if (SplitDwarf == Default)
196 HasSplitDwarf = false;
198 HasSplitDwarf = SplitDwarf == Enable;
200 if (DwarfPubSections == Default)
201 HasDwarfPubSections = !IsDarwin;
203 HasDwarfPubSections = DwarfPubSections == Enable;
205 DwarfVersion = DwarfVersionNumber
207 : MMI->getModule()->getDwarfVersion();
210 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
215 // Switch to the specified MCSection and emit an assembler
216 // temporary label to it if SymbolStem is specified.
217 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
218 const char *SymbolStem = 0) {
219 Asm->OutStreamer.SwitchSection(Section);
223 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
224 Asm->OutStreamer.EmitLabel(TmpSym);
228 DwarfFile::~DwarfFile() {
229 for (DwarfUnit *DU : CUs)
233 MCSymbol *DwarfFile::getStringPoolSym() {
234 return Asm->GetTempSymbol(StringPref);
237 MCSymbol *DwarfFile::getStringPoolEntry(StringRef Str) {
238 std::pair<MCSymbol *, unsigned> &Entry =
239 StringPool.GetOrCreateValue(Str).getValue();
243 Entry.second = NextStringPoolNumber++;
244 return Entry.first = Asm->GetTempSymbol(StringPref, Entry.second);
247 unsigned DwarfFile::getStringPoolIndex(StringRef Str) {
248 std::pair<MCSymbol *, unsigned> &Entry =
249 StringPool.GetOrCreateValue(Str).getValue();
253 Entry.second = NextStringPoolNumber++;
254 Entry.first = Asm->GetTempSymbol(StringPref, Entry.second);
258 unsigned DwarfFile::getAddrPoolIndex(const MCSymbol *Sym, bool TLS) {
259 std::pair<AddrPool::iterator, bool> P = AddressPool.insert(
260 std::make_pair(Sym, AddressPoolEntry(NextAddrPoolNumber, TLS)));
262 ++NextAddrPoolNumber;
263 return P.first->second.Number;
266 // Define a unique number for the abbreviation.
268 void DwarfFile::assignAbbrevNumber(DIEAbbrev &Abbrev) {
269 // Check the set for priors.
270 DIEAbbrev *InSet = AbbreviationsSet.GetOrInsertNode(&Abbrev);
272 // If it's newly added.
273 if (InSet == &Abbrev) {
274 // Add to abbreviation list.
275 Abbreviations.push_back(&Abbrev);
277 // Assign the vector position + 1 as its number.
278 Abbrev.setNumber(Abbreviations.size());
280 // Assign existing abbreviation number.
281 Abbrev.setNumber(InSet->getNumber());
285 static bool isObjCClass(StringRef Name) {
286 return Name.startswith("+") || Name.startswith("-");
289 static bool hasObjCCategory(StringRef Name) {
290 if (!isObjCClass(Name))
293 return Name.find(") ") != StringRef::npos;
296 static void getObjCClassCategory(StringRef In, StringRef &Class,
297 StringRef &Category) {
298 if (!hasObjCCategory(In)) {
299 Class = In.slice(In.find('[') + 1, In.find(' '));
304 Class = In.slice(In.find('[') + 1, In.find('('));
305 Category = In.slice(In.find('[') + 1, In.find(' '));
309 static StringRef getObjCMethodName(StringRef In) {
310 return In.slice(In.find(' ') + 1, In.find(']'));
313 // Helper for sorting sections into a stable output order.
314 static bool SectionSort(const MCSection *A, const MCSection *B) {
315 std::string LA = (A ? A->getLabelBeginName() : "");
316 std::string LB = (B ? B->getLabelBeginName() : "");
320 // Add the various names to the Dwarf accelerator table names.
321 // TODO: Determine whether or not we should add names for programs
322 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
323 // is only slightly different than the lookup of non-standard ObjC names.
324 static void addSubprogramNames(DwarfUnit *TheU, DISubprogram SP, DIE *Die) {
325 if (!SP.isDefinition())
327 TheU->addAccelName(SP.getName(), Die);
329 // If the linkage name is different than the name, go ahead and output
330 // that as well into the name table.
331 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
332 TheU->addAccelName(SP.getLinkageName(), Die);
334 // If this is an Objective-C selector name add it to the ObjC accelerator
336 if (isObjCClass(SP.getName())) {
337 StringRef Class, Category;
338 getObjCClassCategory(SP.getName(), Class, Category);
339 TheU->addAccelObjC(Class, Die);
341 TheU->addAccelObjC(Category, Die);
342 // Also add the base method name to the name table.
343 TheU->addAccelName(getObjCMethodName(SP.getName()), Die);
347 /// isSubprogramContext - Return true if Context is either a subprogram
348 /// or another context nested inside a subprogram.
349 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
352 DIDescriptor D(Context);
353 if (D.isSubprogram())
356 return isSubprogramContext(resolve(DIType(Context).getContext()));
360 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
361 // and DW_AT_high_pc attributes. If there are global variables in this
362 // scope then create and insert DIEs for these variables.
363 DIE *DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit *SPCU,
365 DIE *SPDie = SPCU->getDIE(SP);
367 assert(SPDie && "Unable to find subprogram DIE!");
369 // If we're updating an abstract DIE, then we will be adding the children and
370 // object pointer later on. But what we don't want to do is process the
371 // concrete DIE twice.
372 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
373 // Pick up abstract subprogram DIE.
375 SPCU->createAndAddDIE(dwarf::DW_TAG_subprogram, *SPCU->getUnitDie());
376 SPCU->addDIEEntry(SPDie, dwarf::DW_AT_abstract_origin, AbsSPDIE);
378 DISubprogram SPDecl = SP.getFunctionDeclaration();
379 if (!SPDecl.isSubprogram()) {
380 // There is not any need to generate specification DIE for a function
381 // defined at compile unit level. If a function is defined inside another
382 // function then gdb prefers the definition at top level and but does not
383 // expect specification DIE in parent function. So avoid creating
384 // specification DIE for a function defined inside a function.
385 DIScope SPContext = resolve(SP.getContext());
386 if (SP.isDefinition() && !SPContext.isCompileUnit() &&
387 !SPContext.isFile() && !isSubprogramContext(SPContext)) {
388 SPCU->addFlag(SPDie, dwarf::DW_AT_declaration);
391 DICompositeType SPTy = SP.getType();
392 DIArray Args = SPTy.getTypeArray();
393 uint16_t SPTag = SPTy.getTag();
394 if (SPTag == dwarf::DW_TAG_subroutine_type)
395 SPCU->constructSubprogramArguments(*SPDie, Args);
396 DIE *SPDeclDie = SPDie;
397 SPDie = SPCU->createAndAddDIE(dwarf::DW_TAG_subprogram,
398 *SPCU->getUnitDie());
399 SPCU->addDIEEntry(SPDie, dwarf::DW_AT_specification, SPDeclDie);
404 attachLowHighPC(SPCU, SPDie, FunctionBeginSym, FunctionEndSym);
406 const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
407 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
408 SPCU->addAddress(SPDie, dwarf::DW_AT_frame_base, Location);
410 // Add name to the name table, we do this here because we're guaranteed
411 // to have concrete versions of our DW_TAG_subprogram nodes.
412 addSubprogramNames(SPCU, SP, SPDie);
417 /// Check whether we should create a DIE for the given Scope, return true
418 /// if we don't create a DIE (the corresponding DIE is null).
419 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
420 if (Scope->isAbstractScope())
423 // We don't create a DIE if there is no Range.
424 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
428 if (Ranges.size() > 1)
431 // We don't create a DIE if we have a single Range and the end label
433 SmallVectorImpl<InsnRange>::const_iterator RI = Ranges.begin();
434 MCSymbol *End = getLabelAfterInsn(RI->second);
438 static void addSectionLabel(AsmPrinter *Asm, DwarfUnit *U, DIE *D,
439 dwarf::Attribute A, const MCSymbol *L,
440 const MCSymbol *Sec) {
441 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
442 U->addSectionLabel(D, A, L);
444 U->addSectionDelta(D, A, L, Sec);
447 void DwarfDebug::addScopeRangeList(DwarfCompileUnit *TheCU, DIE *ScopeDIE,
448 const SmallVectorImpl<InsnRange> &Range) {
449 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
450 // emitting it appropriately.
451 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
453 // Under fission, ranges are specified by constant offsets relative to the
454 // CU's DW_AT_GNU_ranges_base.
456 TheCU->addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
457 DwarfDebugRangeSectionSym);
459 addSectionLabel(Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
460 DwarfDebugRangeSectionSym);
462 RangeSpanList List(RangeSym);
463 for (const InsnRange &R : Range) {
464 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
465 List.addRange(std::move(Span));
468 // Add the range list to the set of ranges to be emitted.
469 TheCU->addRangeList(std::move(List));
472 // Construct new DW_TAG_lexical_block for this scope and attach
473 // DW_AT_low_pc/DW_AT_high_pc labels.
474 DIE *DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit *TheCU,
475 LexicalScope *Scope) {
476 if (isLexicalScopeDIENull(Scope))
479 DIE *ScopeDIE = new DIE(dwarf::DW_TAG_lexical_block);
480 if (Scope->isAbstractScope())
483 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
485 // If we have multiple ranges, emit them into the range section.
486 if (ScopeRanges.size() > 1) {
487 addScopeRangeList(TheCU, ScopeDIE, ScopeRanges);
491 // Construct the address range for this DIE.
492 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
493 MCSymbol *Start = getLabelBeforeInsn(RI->first);
494 MCSymbol *End = getLabelAfterInsn(RI->second);
495 assert(End && "End label should not be null!");
497 assert(Start->isDefined() && "Invalid starting label for an inlined scope!");
498 assert(End->isDefined() && "Invalid end label for an inlined scope!");
500 attachLowHighPC(TheCU, ScopeDIE, Start, End);
505 // This scope represents inlined body of a function. Construct DIE to
506 // represent this concrete inlined copy of the function.
507 DIE *DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit *TheCU,
508 LexicalScope *Scope) {
509 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
510 assert(!ScopeRanges.empty() &&
511 "LexicalScope does not have instruction markers!");
513 if (!Scope->getScopeNode())
515 DIScope DS(Scope->getScopeNode());
516 DISubprogram InlinedSP = getDISubprogram(DS);
517 DIE *OriginDIE = TheCU->getDIE(InlinedSP);
519 DEBUG(dbgs() << "Unable to find original DIE for an inlined subprogram.");
523 DIE *ScopeDIE = new DIE(dwarf::DW_TAG_inlined_subroutine);
524 TheCU->addDIEEntry(ScopeDIE, dwarf::DW_AT_abstract_origin, OriginDIE);
526 // If we have multiple ranges, emit them into the range section.
527 if (ScopeRanges.size() > 1)
528 addScopeRangeList(TheCU, ScopeDIE, ScopeRanges);
530 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
531 MCSymbol *StartLabel = getLabelBeforeInsn(RI->first);
532 MCSymbol *EndLabel = getLabelAfterInsn(RI->second);
534 if (StartLabel == 0 || EndLabel == 0)
535 llvm_unreachable("Unexpected Start and End labels for an inlined scope!");
537 assert(StartLabel->isDefined() &&
538 "Invalid starting label for an inlined scope!");
539 assert(EndLabel->isDefined() && "Invalid end label for an inlined scope!");
541 attachLowHighPC(TheCU, ScopeDIE, StartLabel, EndLabel);
544 InlinedSubprogramDIEs.insert(OriginDIE);
546 // Add the call site information to the DIE.
547 DILocation DL(Scope->getInlinedAt());
549 ScopeDIE, dwarf::DW_AT_call_file, None,
550 TheCU->getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
551 TheCU->addUInt(ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
553 // Add name to the name table, we do this here because we're guaranteed
554 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
555 addSubprogramNames(TheCU, InlinedSP, ScopeDIE);
560 DIE *DwarfDebug::createScopeChildrenDIE(DwarfCompileUnit *TheCU,
562 SmallVectorImpl<DIE *> &Children) {
563 DIE *ObjectPointer = NULL;
565 // Collect arguments for current function.
566 if (LScopes.isCurrentFunctionScope(Scope)) {
567 for (DbgVariable &ArgDV : CurrentFnArguments)
568 if (ArgDV.getVariable()) {
569 DIE *Arg = TheCU->constructVariableDIE(ArgDV, Scope->isAbstractScope());
570 Children.push_back(Arg);
571 if (ArgDV.isObjectPointer())
575 // If this is a variadic function, add an unspecified parameter.
576 DISubprogram SP(Scope->getScopeNode());
577 DIArray FnArgs = SP.getType().getTypeArray();
578 if (FnArgs.getElement(FnArgs.getNumElements() - 1)
579 .isUnspecifiedParameter()) {
580 DIE *Ellipsis = new DIE(dwarf::DW_TAG_unspecified_parameters);
581 Children.push_back(Ellipsis);
585 // Collect lexical scope children first.
586 for (DbgVariable &DV : ScopeVariables.lookup(Scope))
587 if (DIE *Variable = TheCU->constructVariableDIE(DV,
588 Scope->isAbstractScope())) {
589 Children.push_back(Variable);
590 if (DV.isObjectPointer())
591 ObjectPointer = Variable;
593 for (LexicalScope *LS : Scope->getChildren())
594 if (DIE *Nested = constructScopeDIE(TheCU, LS))
595 Children.push_back(Nested);
596 return ObjectPointer;
599 // Construct a DIE for this scope.
600 DIE *DwarfDebug::constructScopeDIE(DwarfCompileUnit *TheCU,
601 LexicalScope *Scope) {
602 if (!Scope || !Scope->getScopeNode())
605 DIScope DS(Scope->getScopeNode());
607 SmallVector<DIE *, 8> Children;
608 DIE *ObjectPointer = NULL;
609 bool ChildrenCreated = false;
611 // We try to create the scope DIE first, then the children DIEs. This will
612 // avoid creating un-used children then removing them later when we find out
613 // the scope DIE is null.
614 DIE *ScopeDIE = NULL;
615 if (Scope->getInlinedAt())
616 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
617 else if (DS.isSubprogram()) {
618 ProcessedSPNodes.insert(DS);
619 if (Scope->isAbstractScope()) {
620 ScopeDIE = TheCU->getDIE(DS);
621 // Note down abstract DIE.
623 AbstractSPDies.insert(std::make_pair(DS, ScopeDIE));
625 ScopeDIE = updateSubprogramScopeDIE(TheCU, DISubprogram(DS));
627 // Early exit when we know the scope DIE is going to be null.
628 if (isLexicalScopeDIENull(Scope))
631 // We create children here when we know the scope DIE is not going to be
632 // null and the children will be added to the scope DIE.
633 ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
634 ChildrenCreated = true;
636 // There is no need to emit empty lexical block DIE.
637 std::pair<ImportedEntityMap::const_iterator,
638 ImportedEntityMap::const_iterator> Range =
640 ScopesWithImportedEntities.begin(),
641 ScopesWithImportedEntities.end(),
642 std::pair<const MDNode *, const MDNode *>(DS, (const MDNode *)0),
644 if (Children.empty() && Range.first == Range.second)
646 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
647 assert(ScopeDIE && "Scope DIE should not be null.");
648 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
650 constructImportedEntityDIE(TheCU, i->second, ScopeDIE);
654 assert(Children.empty() &&
655 "We create children only when the scope DIE is not null.");
658 if (!ChildrenCreated)
659 // We create children when the scope DIE is not null.
660 ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
663 for (DIE *I : Children)
664 ScopeDIE->addChild(I);
666 if (DS.isSubprogram() && ObjectPointer != NULL)
667 TheCU->addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, ObjectPointer);
672 void DwarfDebug::addGnuPubAttributes(DwarfUnit *U, DIE *D) const {
673 if (!GenerateGnuPubSections)
676 U->addFlag(D, dwarf::DW_AT_GNU_pubnames);
679 // Create new DwarfCompileUnit for the given metadata node with tag
680 // DW_TAG_compile_unit.
681 DwarfCompileUnit *DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
682 StringRef FN = DIUnit.getFilename();
683 CompilationDir = DIUnit.getDirectory();
685 DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
686 DwarfCompileUnit *NewCU = new DwarfCompileUnit(
687 InfoHolder.getUnits().size(), Die, DIUnit, Asm, this, &InfoHolder);
688 InfoHolder.addUnit(NewCU);
690 // LTO with assembly output shares a single line table amongst multiple CUs.
691 // To avoid the compilation directory being ambiguous, let the line table
692 // explicitly describe the directory of all files, never relying on the
693 // compilation directory.
694 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
695 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
696 NewCU->getUniqueID(), CompilationDir);
698 NewCU->addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
699 NewCU->addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
700 DIUnit.getLanguage());
701 NewCU->addString(Die, dwarf::DW_AT_name, FN);
703 if (!useSplitDwarf()) {
704 NewCU->initStmtList(DwarfLineSectionSym);
706 // If we're using split dwarf the compilation dir is going to be in the
707 // skeleton CU and so we don't need to duplicate it here.
708 if (!CompilationDir.empty())
709 NewCU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
711 addGnuPubAttributes(NewCU, Die);
714 if (DIUnit.isOptimized())
715 NewCU->addFlag(Die, dwarf::DW_AT_APPLE_optimized);
717 StringRef Flags = DIUnit.getFlags();
719 NewCU->addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
721 if (unsigned RVer = DIUnit.getRunTimeVersion())
722 NewCU->addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
723 dwarf::DW_FORM_data1, RVer);
728 if (useSplitDwarf()) {
729 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
730 DwarfInfoDWOSectionSym);
731 NewCU->setSkeleton(constructSkeletonCU(NewCU));
733 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
734 DwarfInfoSectionSym);
736 CUMap.insert(std::make_pair(DIUnit, NewCU));
737 CUDieMap.insert(std::make_pair(Die, NewCU));
741 // Construct subprogram DIE.
742 void DwarfDebug::constructSubprogramDIE(DwarfCompileUnit *TheCU,
744 // FIXME: We should only call this routine once, however, during LTO if a
745 // program is defined in multiple CUs we could end up calling it out of
746 // beginModule as we walk the CUs.
748 DwarfCompileUnit *&CURef = SPMap[N];
754 if (!SP.isDefinition())
755 // This is a method declaration which will be handled while constructing
759 DIE *SubprogramDie = TheCU->getOrCreateSubprogramDIE(SP);
761 // Expose as a global name.
762 TheCU->addGlobalName(SP.getName(), SubprogramDie, resolve(SP.getContext()));
765 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
767 DIImportedEntity Module(N);
768 assert(Module.Verify());
769 if (DIE *D = TheCU->getOrCreateContextDIE(Module.getContext()))
770 constructImportedEntityDIE(TheCU, Module, D);
773 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
774 const MDNode *N, DIE *Context) {
775 DIImportedEntity Module(N);
776 assert(Module.Verify());
777 return constructImportedEntityDIE(TheCU, Module, Context);
780 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
781 const DIImportedEntity &Module,
783 assert(Module.Verify() &&
784 "Use one of the MDNode * overloads to handle invalid metadata");
785 assert(Context && "Should always have a context for an imported_module");
786 DIE *IMDie = TheCU->createAndAddDIE(Module.getTag(), *Context, Module);
788 DIDescriptor Entity = resolve(Module.getEntity());
789 if (Entity.isNameSpace())
790 EntityDie = TheCU->getOrCreateNameSpace(DINameSpace(Entity));
791 else if (Entity.isSubprogram())
792 EntityDie = TheCU->getOrCreateSubprogramDIE(DISubprogram(Entity));
793 else if (Entity.isType())
794 EntityDie = TheCU->getOrCreateTypeDIE(DIType(Entity));
796 EntityDie = TheCU->getDIE(Entity);
797 TheCU->addSourceLine(IMDie, Module.getLineNumber(),
798 Module.getContext().getFilename(),
799 Module.getContext().getDirectory());
800 TheCU->addDIEEntry(IMDie, dwarf::DW_AT_import, EntityDie);
801 StringRef Name = Module.getName();
803 TheCU->addString(IMDie, dwarf::DW_AT_name, Name);
806 // Emit all Dwarf sections that should come prior to the content. Create
807 // global DIEs and emit initial debug info sections. This is invoked by
808 // the target AsmPrinter.
809 void DwarfDebug::beginModule() {
810 if (DisableDebugInfoPrinting)
813 const Module *M = MMI->getModule();
815 // If module has named metadata anchors then use them, otherwise scan the
816 // module using debug info finder to collect debug info.
817 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
820 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
822 // Emit initial sections so we can reference labels later.
825 SingleCU = CU_Nodes->getNumOperands() == 1;
827 for (MDNode *N : CU_Nodes->operands()) {
828 DICompileUnit CUNode(N);
829 DwarfCompileUnit *CU = constructDwarfCompileUnit(CUNode);
830 DIArray ImportedEntities = CUNode.getImportedEntities();
831 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
832 ScopesWithImportedEntities.push_back(std::make_pair(
833 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
834 ImportedEntities.getElement(i)));
835 std::sort(ScopesWithImportedEntities.begin(),
836 ScopesWithImportedEntities.end(), less_first());
837 DIArray GVs = CUNode.getGlobalVariables();
838 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
839 CU->createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
840 DIArray SPs = CUNode.getSubprograms();
841 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
842 constructSubprogramDIE(CU, SPs.getElement(i));
843 DIArray EnumTypes = CUNode.getEnumTypes();
844 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
845 CU->getOrCreateTypeDIE(EnumTypes.getElement(i));
846 DIArray RetainedTypes = CUNode.getRetainedTypes();
847 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
848 DIType Ty(RetainedTypes.getElement(i));
849 // The retained types array by design contains pointers to
850 // MDNodes rather than DIRefs. Unique them here.
851 DIType UniqueTy(resolve(Ty.getRef()));
852 CU->getOrCreateTypeDIE(UniqueTy);
854 // Emit imported_modules last so that the relevant context is already
856 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
857 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
860 // Tell MMI that we have debug info.
861 MMI->setDebugInfoAvailability(true);
863 // Prime section data.
864 SectionMap[Asm->getObjFileLowering().getTextSection()];
867 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
868 void DwarfDebug::computeInlinedDIEs() {
869 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
870 for (DIE *ISP : InlinedSubprogramDIEs)
871 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
873 for (const auto &AI : AbstractSPDies) {
874 DIE *ISP = AI.second;
875 if (InlinedSubprogramDIEs.count(ISP))
877 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
881 // Collect info for variables that were optimized out.
882 void DwarfDebug::collectDeadVariables() {
883 const Module *M = MMI->getModule();
885 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
886 for (MDNode *N : CU_Nodes->operands()) {
887 DICompileUnit TheCU(N);
888 DIArray Subprograms = TheCU.getSubprograms();
889 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
890 DISubprogram SP(Subprograms.getElement(i));
891 if (ProcessedSPNodes.count(SP) != 0)
893 if (!SP.isSubprogram())
895 if (!SP.isDefinition())
897 DIArray Variables = SP.getVariables();
898 if (Variables.getNumElements() == 0)
901 // Construct subprogram DIE and add variables DIEs.
902 DwarfCompileUnit *SPCU =
903 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
904 assert(SPCU && "Unable to find Compile Unit!");
905 // FIXME: See the comment in constructSubprogramDIE about duplicate
907 constructSubprogramDIE(SPCU, SP);
908 DIE *SPDIE = SPCU->getDIE(SP);
909 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
910 DIVariable DV(Variables.getElement(vi));
911 if (!DV.isVariable())
913 DbgVariable NewVar(DV, NULL, this);
914 if (DIE *VariableDIE = SPCU->constructVariableDIE(NewVar, false))
915 SPDIE->addChild(VariableDIE);
922 void DwarfDebug::finalizeModuleInfo() {
923 // Collect info for variables that were optimized out.
924 collectDeadVariables();
926 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
927 computeInlinedDIEs();
929 // Handle anything that needs to be done on a per-unit basis after
930 // all other generation.
931 for (DwarfUnit *TheU : getUnits()) {
932 // Emit DW_AT_containing_type attribute to connect types with their
933 // vtable holding type.
934 TheU->constructContainingTypeDIEs();
936 // Add CU specific attributes if we need to add any.
937 if (TheU->getUnitDie()->getTag() == dwarf::DW_TAG_compile_unit) {
938 // If we're splitting the dwarf out now that we've got the entire
939 // CU then add the dwo id to it.
940 DwarfCompileUnit *SkCU =
941 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
942 if (useSplitDwarf()) {
943 // Emit a unique identifier for this CU.
944 uint64_t ID = DIEHash(Asm).computeCUSignature(*TheU->getUnitDie());
945 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
946 dwarf::DW_FORM_data8, ID);
947 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
948 dwarf::DW_FORM_data8, ID);
950 // We don't keep track of which addresses are used in which CU so this
951 // is a bit pessimistic under LTO.
952 if (!InfoHolder.getAddrPool()->empty())
953 addSectionLabel(Asm, SkCU, SkCU->getUnitDie(),
954 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
955 DwarfAddrSectionSym);
956 if (!TheU->getRangeLists().empty())
957 addSectionLabel(Asm, SkCU, SkCU->getUnitDie(),
958 dwarf::DW_AT_GNU_ranges_base,
959 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
962 // If we have code split among multiple sections or non-contiguous
963 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
964 // remain in the .o file, otherwise add a DW_AT_low_pc.
965 // FIXME: We should use ranges allow reordering of code ala
966 // .subsections_via_symbols in mach-o. This would mean turning on
967 // ranges for all subprogram DIEs for mach-o.
968 DwarfCompileUnit *U = SkCU ? SkCU : static_cast<DwarfCompileUnit *>(TheU);
969 unsigned NumRanges = TheU->getRanges().size();
972 addSectionLabel(Asm, U, U->getUnitDie(), dwarf::DW_AT_ranges,
973 Asm->GetTempSymbol("cu_ranges", U->getUniqueID()),
974 DwarfDebugRangeSectionSym);
976 // A DW_AT_low_pc attribute may also be specified in combination with
977 // DW_AT_ranges to specify the default base address for use in
978 // location lists (see Section 2.6.2) and range lists (see Section
980 U->addUInt(U->getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
983 RangeSpan &Range = TheU->getRanges().back();
984 U->addLocalLabelAddress(U->getUnitDie(), dwarf::DW_AT_low_pc,
986 U->addLabelDelta(U->getUnitDie(), dwarf::DW_AT_high_pc,
987 Range.getEnd(), Range.getStart());
993 // Compute DIE offsets and sizes.
994 InfoHolder.computeSizeAndOffsets();
996 SkeletonHolder.computeSizeAndOffsets();
999 void DwarfDebug::endSections() {
1000 // Filter labels by section.
1001 for (const SymbolCU &SCU : ArangeLabels) {
1002 if (SCU.Sym->isInSection()) {
1003 // Make a note of this symbol and it's section.
1004 const MCSection *Section = &SCU.Sym->getSection();
1005 if (!Section->getKind().isMetadata())
1006 SectionMap[Section].push_back(SCU);
1008 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1009 // appear in the output. This sucks as we rely on sections to build
1010 // arange spans. We can do it without, but it's icky.
1011 SectionMap[NULL].push_back(SCU);
1015 // Build a list of sections used.
1016 std::vector<const MCSection *> Sections;
1017 for (const auto &it : SectionMap) {
1018 const MCSection *Section = it.first;
1019 Sections.push_back(Section);
1022 // Sort the sections into order.
1023 // This is only done to ensure consistent output order across different runs.
1024 std::sort(Sections.begin(), Sections.end(), SectionSort);
1026 // Add terminating symbols for each section.
1027 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1028 const MCSection *Section = Sections[ID];
1029 MCSymbol *Sym = NULL;
1032 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1033 // if we know the section name up-front. For user-created sections, the
1034 // resulting label may not be valid to use as a label. (section names can
1035 // use a greater set of characters on some systems)
1036 Sym = Asm->GetTempSymbol("debug_end", ID);
1037 Asm->OutStreamer.SwitchSection(Section);
1038 Asm->OutStreamer.EmitLabel(Sym);
1041 // Insert a final terminator.
1042 SectionMap[Section].push_back(SymbolCU(NULL, Sym));
1046 // Emit all Dwarf sections that should come after the content.
1047 void DwarfDebug::endModule() {
1054 // End any existing sections.
1055 // TODO: Does this need to happen?
1058 // Finalize the debug info for the module.
1059 finalizeModuleInfo();
1063 // Emit all the DIEs into a debug info section.
1066 // Corresponding abbreviations into a abbrev section.
1067 emitAbbreviations();
1069 // Emit info into a debug aranges section.
1070 if (GenerateARangeSection)
1073 // Emit info into a debug ranges section.
1076 if (useSplitDwarf()) {
1079 emitDebugAbbrevDWO();
1081 // Emit DWO addresses.
1082 InfoHolder.emitAddresses(Asm->getObjFileLowering().getDwarfAddrSection());
1085 // Emit info into a debug loc section.
1088 // Emit info into the dwarf accelerator table sections.
1089 if (useDwarfAccelTables()) {
1092 emitAccelNamespaces();
1096 // Emit the pubnames and pubtypes sections if requested.
1097 if (HasDwarfPubSections) {
1098 emitDebugPubNames(GenerateGnuPubSections);
1099 emitDebugPubTypes(GenerateGnuPubSections);
1105 // Reset these for the next Module if we have one.
1109 // Find abstract variable, if any, associated with Var.
1110 DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
1111 DebugLoc ScopeLoc) {
1112 LLVMContext &Ctx = DV->getContext();
1113 // More then one inlined variable corresponds to one abstract variable.
1114 DIVariable Var = cleanseInlinedVariable(DV, Ctx);
1115 DbgVariable *AbsDbgVariable = AbstractVariables.lookup(Var);
1117 return AbsDbgVariable;
1119 LexicalScope *Scope = LScopes.findAbstractScope(ScopeLoc.getScope(Ctx));
1123 AbsDbgVariable = &addScopeVariable(Scope, DbgVariable(Var, NULL, this));
1124 AbstractVariables[Var] = AbsDbgVariable;
1125 return AbsDbgVariable;
1128 // If Var is a current function argument then add it to CurrentFnArguments list.
1129 DbgVariable *DwarfDebug::addCurrentFnArgument(DbgVariable &Var, LexicalScope *Scope) {
1130 if (!LScopes.isCurrentFunctionScope(Scope))
1132 DIVariable DV = Var.getVariable();
1133 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1135 unsigned ArgNo = DV.getArgNumber();
1139 auto I = CurrentFnArguments.begin();
1140 for (; I != CurrentFnArguments.end(); ++I)
1141 if (ArgNo < I->getVariable().getArgNumber())
1143 return &*CurrentFnArguments.insert(I, std::move(Var));
1146 DbgVariable &DwarfDebug::addVariable(DbgVariable Var, LexicalScope *Scope) {
1147 if (DbgVariable *Res = addCurrentFnArgument(Var, Scope))
1149 return addScopeVariable(Scope, std::move(Var));
1152 // Collect variable information from side table maintained by MMI.
1153 void DwarfDebug::collectVariableInfoFromMMITable(
1154 SmallPtrSet<const MDNode *, 16> &Processed) {
1155 for (const auto &VI : MMI->getVariableDbgInfo()) {
1158 Processed.insert(VI.Var);
1159 DIVariable DV(VI.Var);
1160 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1162 // If variable scope is not found then skip this variable.
1166 DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VI.Loc);
1167 DbgVariable RegVar(DV, AbsDbgVariable, this);
1168 RegVar.setFrameIndex(VI.Slot);
1169 addVariable(std::move(RegVar), Scope);
1171 AbsDbgVariable->setFrameIndex(VI.Slot);
1175 // Return true if debug value, encoded by DBG_VALUE instruction, is in a
1177 static bool isDbgValueInDefinedReg(const MachineInstr *MI) {
1178 assert(MI->isDebugValue() && "Invalid DBG_VALUE machine instruction!");
1179 return MI->getNumOperands() == 3 && MI->getOperand(0).isReg() &&
1180 MI->getOperand(0).getReg() &&
1181 (MI->getOperand(1).isImm() ||
1182 (MI->getOperand(1).isReg() && MI->getOperand(1).getReg() == 0U));
1185 // Get .debug_loc entry for the instruction range starting at MI.
1186 static DebugLocEntry getDebugLocEntry(AsmPrinter *Asm,
1187 const MCSymbol *FLabel,
1188 const MCSymbol *SLabel,
1189 const MachineInstr *MI,
1190 DwarfCompileUnit *Unit) {
1191 const MDNode *Var = MI->getDebugVariable();
1193 assert(MI->getNumOperands() == 3);
1194 if (MI->getOperand(0).isReg()) {
1195 MachineLocation MLoc;
1196 // If the second operand is an immediate, this is a
1197 // register-indirect address.
1198 if (!MI->getOperand(1).isImm())
1199 MLoc.set(MI->getOperand(0).getReg());
1201 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1202 return DebugLocEntry(FLabel, SLabel, MLoc, Var, Unit);
1204 if (MI->getOperand(0).isImm())
1205 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getImm(), Var, Unit);
1206 if (MI->getOperand(0).isFPImm())
1207 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getFPImm(),
1209 if (MI->getOperand(0).isCImm())
1210 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getCImm(),
1213 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1216 // Find variables for each lexical scope.
1218 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1220 // Grab the variable info that was squirreled away in the MMI side-table.
1221 collectVariableInfoFromMMITable(Processed);
1223 for (const MDNode *Var : UserVariables) {
1224 if (Processed.count(Var))
1227 // History contains relevant DBG_VALUE instructions for Var and instructions
1229 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1230 if (History.empty())
1232 const MachineInstr *MInsn = History.front();
1235 LexicalScope *Scope = NULL;
1236 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1237 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1238 Scope = LScopes.getCurrentFunctionScope();
1239 else if (MDNode *IA = DV.getInlinedAt())
1240 Scope = LScopes.findInlinedScope(DebugLoc::getFromDILocation(IA));
1242 Scope = LScopes.findLexicalScope(cast<MDNode>(DV->getOperand(1)));
1243 // If variable scope is not found then skip this variable.
1247 Processed.insert(DV);
1248 assert(MInsn->isDebugValue() && "History must begin with debug value");
1249 DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
1250 DbgVariable &RegVar = addVariable(DbgVariable(DV, AbsVar, this), Scope);
1252 AbsVar->setMInsn(MInsn);
1254 // Simplify ranges that are fully coalesced.
1255 if (History.size() <= 1 ||
1256 (History.size() == 2 && MInsn->isIdenticalTo(History.back()))) {
1257 RegVar.setMInsn(MInsn);
1261 // Handle multiple DBG_VALUE instructions describing one variable.
1262 RegVar.setDotDebugLocOffset(DotDebugLocEntries.size());
1264 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1265 DebugLocList &LocList = DotDebugLocEntries.back();
1267 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1268 SmallVector<DebugLocEntry, 4> &DebugLoc = LocList.List;
1269 for (SmallVectorImpl<const MachineInstr *>::const_iterator
1270 HI = History.begin(),
1273 const MachineInstr *Begin = *HI;
1274 assert(Begin->isDebugValue() && "Invalid History entry");
1276 // Check if DBG_VALUE is truncating a range.
1277 if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1278 !Begin->getOperand(0).getReg())
1281 // Compute the range for a register location.
1282 const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
1283 const MCSymbol *SLabel = 0;
1286 // If Begin is the last instruction in History then its value is valid
1287 // until the end of the function.
1288 SLabel = FunctionEndSym;
1290 const MachineInstr *End = HI[1];
1291 DEBUG(dbgs() << "DotDebugLoc Pair:\n"
1292 << "\t" << *Begin << "\t" << *End << "\n");
1293 if (End->isDebugValue())
1294 SLabel = getLabelBeforeInsn(End);
1296 // End is a normal instruction clobbering the range.
1297 SLabel = getLabelAfterInsn(End);
1298 assert(SLabel && "Forgot label after clobber instruction");
1303 // The value is valid until the next DBG_VALUE or clobber.
1304 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1305 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1306 DebugLocEntry Loc = getDebugLocEntry(Asm, FLabel, SLabel, Begin, TheCU);
1307 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc))
1308 DebugLoc.push_back(std::move(Loc));
1312 // Collect info for variables that were optimized out.
1313 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1314 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1315 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1316 DIVariable DV(Variables.getElement(i));
1317 if (!DV || !DV.isVariable() || !Processed.insert(DV))
1319 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
1320 addScopeVariable(Scope, DbgVariable(DV, NULL, this));
1324 // Return Label preceding the instruction.
1325 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1326 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1327 assert(Label && "Didn't insert label before instruction");
1331 // Return Label immediately following the instruction.
1332 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1333 return LabelsAfterInsn.lookup(MI);
1336 // Process beginning of an instruction.
1337 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1340 // Check if source location changes, but ignore DBG_VALUE locations.
1341 if (!MI->isDebugValue()) {
1342 DebugLoc DL = MI->getDebugLoc();
1343 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1346 if (DL == PrologEndLoc) {
1347 Flags |= DWARF2_FLAG_PROLOGUE_END;
1348 PrologEndLoc = DebugLoc();
1350 if (PrologEndLoc.isUnknown())
1351 Flags |= DWARF2_FLAG_IS_STMT;
1353 if (!DL.isUnknown()) {
1354 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1355 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1357 recordSourceLine(0, 0, 0, 0);
1361 // Insert labels where requested.
1362 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1363 LabelsBeforeInsn.find(MI);
1366 if (I == LabelsBeforeInsn.end())
1369 // Label already assigned.
1374 PrevLabel = MMI->getContext().CreateTempSymbol();
1375 Asm->OutStreamer.EmitLabel(PrevLabel);
1377 I->second = PrevLabel;
1380 // Process end of an instruction.
1381 void DwarfDebug::endInstruction() {
1383 // Don't create a new label after DBG_VALUE instructions.
1384 // They don't generate code.
1385 if (!CurMI->isDebugValue())
1388 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1389 LabelsAfterInsn.find(CurMI);
1393 if (I == LabelsAfterInsn.end())
1396 // Label already assigned.
1400 // We need a label after this instruction.
1402 PrevLabel = MMI->getContext().CreateTempSymbol();
1403 Asm->OutStreamer.EmitLabel(PrevLabel);
1405 I->second = PrevLabel;
1408 // Each LexicalScope has first instruction and last instruction to mark
1409 // beginning and end of a scope respectively. Create an inverse map that list
1410 // scopes starts (and ends) with an instruction. One instruction may start (or
1411 // end) multiple scopes. Ignore scopes that are not reachable.
1412 void DwarfDebug::identifyScopeMarkers() {
1413 SmallVector<LexicalScope *, 4> WorkList;
1414 WorkList.push_back(LScopes.getCurrentFunctionScope());
1415 while (!WorkList.empty()) {
1416 LexicalScope *S = WorkList.pop_back_val();
1418 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1419 if (!Children.empty())
1420 WorkList.append(Children.begin(), Children.end());
1422 if (S->isAbstractScope())
1425 for (const InsnRange &R : S->getRanges()) {
1426 assert(R.first && "InsnRange does not have first instruction!");
1427 assert(R.second && "InsnRange does not have second instruction!");
1428 requestLabelBeforeInsn(R.first);
1429 requestLabelAfterInsn(R.second);
1434 // Gather pre-function debug information. Assumes being called immediately
1435 // after the function entry point has been emitted.
1436 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1439 // If there's no debug info for the function we're not going to do anything.
1440 if (!MMI->hasDebugInfo())
1443 // Grab the lexical scopes for the function, if we don't have any of those
1444 // then we're not going to be able to do anything.
1445 LScopes.initialize(*MF);
1446 if (LScopes.empty())
1449 assert(UserVariables.empty() && DbgValues.empty() && "Maps weren't cleaned");
1451 // Make sure that each lexical scope will have a begin/end label.
1452 identifyScopeMarkers();
1454 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1455 // belongs to so that we add to the correct per-cu line table in the
1457 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1458 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1459 assert(TheCU && "Unable to find compile unit!");
1460 if (Asm->OutStreamer.hasRawTextSupport())
1461 // Use a single line table if we are generating assembly.
1462 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1464 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1466 // Emit a label for the function so that we have a beginning address.
1467 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1468 // Assumes in correct section after the entry point.
1469 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1471 const TargetRegisterInfo *TRI = Asm->TM.getRegisterInfo();
1472 // LiveUserVar - Map physreg numbers to the MDNode they contain.
1473 std::vector<const MDNode *> LiveUserVar(TRI->getNumRegs());
1475 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); I != E;
1477 bool AtBlockEntry = true;
1478 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
1480 const MachineInstr *MI = II;
1482 if (MI->isDebugValue()) {
1483 assert(MI->getNumOperands() > 1 && "Invalid machine instruction!");
1485 // Keep track of user variables.
1486 const MDNode *Var = MI->getDebugVariable();
1488 // Variable is in a register, we need to check for clobbers.
1489 if (isDbgValueInDefinedReg(MI))
1490 LiveUserVar[MI->getOperand(0).getReg()] = Var;
1492 // Check the history of this variable.
1493 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1494 if (History.empty()) {
1495 UserVariables.push_back(Var);
1496 // The first mention of a function argument gets the FunctionBeginSym
1497 // label, so arguments are visible when breaking at function entry.
1499 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1500 getDISubprogram(DV.getContext()).describes(MF->getFunction()))
1501 LabelsBeforeInsn[MI] = FunctionBeginSym;
1503 // We have seen this variable before. Try to coalesce DBG_VALUEs.
1504 const MachineInstr *Prev = History.back();
1505 if (Prev->isDebugValue()) {
1506 // Coalesce identical entries at the end of History.
1507 if (History.size() >= 2 &&
1508 Prev->isIdenticalTo(History[History.size() - 2])) {
1509 DEBUG(dbgs() << "Coalescing identical DBG_VALUE entries:\n"
1510 << "\t" << *Prev << "\t"
1511 << *History[History.size() - 2] << "\n");
1515 // Terminate old register assignments that don't reach MI;
1516 MachineFunction::const_iterator PrevMBB = Prev->getParent();
1517 if (PrevMBB != I && (!AtBlockEntry || std::next(PrevMBB) != I) &&
1518 isDbgValueInDefinedReg(Prev)) {
1519 // Previous register assignment needs to terminate at the end of
1521 MachineBasicBlock::const_iterator LastMI =
1522 PrevMBB->getLastNonDebugInstr();
1523 if (LastMI == PrevMBB->end()) {
1524 // Drop DBG_VALUE for empty range.
1525 DEBUG(dbgs() << "Dropping DBG_VALUE for empty range:\n"
1526 << "\t" << *Prev << "\n");
1528 } else if (std::next(PrevMBB) != PrevMBB->getParent()->end())
1529 // Terminate after LastMI.
1530 History.push_back(LastMI);
1534 History.push_back(MI);
1536 // Not a DBG_VALUE instruction.
1537 if (!MI->isPosition())
1538 AtBlockEntry = false;
1540 // First known non-DBG_VALUE and non-frame setup location marks
1541 // the beginning of the function body.
1542 if (!MI->getFlag(MachineInstr::FrameSetup) &&
1543 (PrologEndLoc.isUnknown() && !MI->getDebugLoc().isUnknown()))
1544 PrologEndLoc = MI->getDebugLoc();
1546 // Check if the instruction clobbers any registers with debug vars.
1547 for (const MachineOperand &MO : MI->operands()) {
1548 if (!MO.isReg() || !MO.isDef() || !MO.getReg())
1550 for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid();
1553 const MDNode *Var = LiveUserVar[Reg];
1556 // Reg is now clobbered.
1557 LiveUserVar[Reg] = 0;
1559 // Was MD last defined by a DBG_VALUE referring to Reg?
1560 DbgValueHistoryMap::iterator HistI = DbgValues.find(Var);
1561 if (HistI == DbgValues.end())
1563 SmallVectorImpl<const MachineInstr *> &History = HistI->second;
1564 if (History.empty())
1566 const MachineInstr *Prev = History.back();
1567 // Sanity-check: Register assignments are terminated at the end of
1569 if (!Prev->isDebugValue() || Prev->getParent() != MI->getParent())
1571 // Is the variable still in Reg?
1572 if (!isDbgValueInDefinedReg(Prev) ||
1573 Prev->getOperand(0).getReg() != Reg)
1575 // Var is clobbered. Make sure the next instruction gets a label.
1576 History.push_back(MI);
1583 for (auto &I : DbgValues) {
1584 SmallVectorImpl<const MachineInstr *> &History = I.second;
1585 if (History.empty())
1588 // Make sure the final register assignments are terminated.
1589 const MachineInstr *Prev = History.back();
1590 if (Prev->isDebugValue() && isDbgValueInDefinedReg(Prev)) {
1591 const MachineBasicBlock *PrevMBB = Prev->getParent();
1592 MachineBasicBlock::const_iterator LastMI =
1593 PrevMBB->getLastNonDebugInstr();
1594 if (LastMI == PrevMBB->end())
1595 // Drop DBG_VALUE for empty range.
1597 else if (PrevMBB != &PrevMBB->getParent()->back()) {
1598 // Terminate after LastMI.
1599 History.push_back(LastMI);
1602 // Request labels for the full history.
1603 for (const MachineInstr *MI : History) {
1604 if (MI->isDebugValue())
1605 requestLabelBeforeInsn(MI);
1607 requestLabelAfterInsn(MI);
1611 PrevInstLoc = DebugLoc();
1612 PrevLabel = FunctionBeginSym;
1614 // Record beginning of function.
1615 if (!PrologEndLoc.isUnknown()) {
1616 DebugLoc FnStartDL =
1617 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1619 FnStartDL.getLine(), FnStartDL.getCol(),
1620 FnStartDL.getScope(MF->getFunction()->getContext()),
1621 // We'd like to list the prologue as "not statements" but GDB behaves
1622 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1623 DWARF2_FLAG_IS_STMT);
1627 DbgVariable &DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable Var) {
1628 auto &Vars = ScopeVariables[LS];
1629 DIVariable DV = Var.getVariable();
1630 // Variables with positive arg numbers are parameters.
1631 if (unsigned ArgNum = DV.getArgNumber()) {
1632 // Keep all parameters in order at the start of the variable list to ensure
1633 // function types are correct (no out-of-order parameters)
1635 // This could be improved by only doing it for optimized builds (unoptimized
1636 // builds have the right order to begin with), searching from the back (this
1637 // would catch the unoptimized case quickly), or doing a binary search
1638 // rather than linear search.
1639 auto I = Vars.begin();
1640 while (I != Vars.end()) {
1641 unsigned CurNum = I->getVariable().getArgNumber();
1642 // A local (non-parameter) variable has been found, insert immediately
1646 // A later indexed parameter has been found, insert immediately before it.
1647 if (CurNum > ArgNum)
1651 return *Vars.insert(I, std::move(Var));
1654 Vars.push_back(std::move(Var));
1658 // Gather and emit post-function debug information.
1659 void DwarfDebug::endFunction(const MachineFunction *MF) {
1660 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1661 // though the beginFunction may not be called at all.
1662 // We should handle both cases.
1666 assert(CurFn == MF);
1669 if (!MMI->hasDebugInfo() || LScopes.empty()) {
1670 // If we don't have a lexical scope for this function then there will
1671 // be a hole in the range information. Keep note of this by setting the
1672 // previously used section to nullptr.
1673 PrevSection = nullptr;
1679 // Define end label for subprogram.
1680 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1681 // Assumes in correct section after the entry point.
1682 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1684 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1685 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1687 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1688 collectVariableInfo(ProcessedVars);
1690 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1691 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1692 assert(TheCU && "Unable to find compile unit!");
1694 // Construct abstract scopes.
1695 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1696 DISubprogram SP(AScope->getScopeNode());
1697 if (SP.isSubprogram()) {
1698 // Collect info for variables that were optimized out.
1699 DIArray Variables = SP.getVariables();
1700 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1701 DIVariable DV(Variables.getElement(i));
1702 if (!DV || !DV.isVariable() || !ProcessedVars.insert(DV))
1704 // Check that DbgVariable for DV wasn't created earlier, when
1705 // findAbstractVariable() was called for inlined instance of DV.
1706 LLVMContext &Ctx = DV->getContext();
1707 DIVariable CleanDV = cleanseInlinedVariable(DV, Ctx);
1708 if (AbstractVariables.lookup(CleanDV))
1710 if (LexicalScope *Scope = LScopes.findAbstractScope(DV.getContext()))
1711 addScopeVariable(Scope, DbgVariable(DV, NULL, this));
1714 if (ProcessedSPNodes.count(AScope->getScopeNode()) == 0)
1715 constructScopeDIE(TheCU, AScope);
1718 DIE *CurFnDIE = constructScopeDIE(TheCU, FnScope);
1719 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1720 TheCU->addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1722 // Add the range of this function to the list of ranges for the CU.
1723 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1724 TheCU->addRange(std::move(Span));
1725 PrevSection = Asm->getCurrentSection();
1729 ScopeVariables.clear();
1730 CurrentFnArguments.clear();
1731 UserVariables.clear();
1733 AbstractVariables.clear();
1734 LabelsBeforeInsn.clear();
1735 LabelsAfterInsn.clear();
1740 // Register a source line with debug info. Returns the unique label that was
1741 // emitted and which provides correspondence to the source line list.
1742 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1747 unsigned Discriminator = 0;
1749 DIDescriptor Scope(S);
1751 if (Scope.isCompileUnit()) {
1752 DICompileUnit CU(S);
1753 Fn = CU.getFilename();
1754 Dir = CU.getDirectory();
1755 } else if (Scope.isFile()) {
1757 Fn = F.getFilename();
1758 Dir = F.getDirectory();
1759 } else if (Scope.isSubprogram()) {
1761 Fn = SP.getFilename();
1762 Dir = SP.getDirectory();
1763 } else if (Scope.isLexicalBlockFile()) {
1764 DILexicalBlockFile DBF(S);
1765 Fn = DBF.getFilename();
1766 Dir = DBF.getDirectory();
1767 } else if (Scope.isLexicalBlock()) {
1768 DILexicalBlock DB(S);
1769 Fn = DB.getFilename();
1770 Dir = DB.getDirectory();
1771 Discriminator = DB.getDiscriminator();
1773 llvm_unreachable("Unexpected scope info");
1775 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1776 Src = static_cast<DwarfCompileUnit *>(InfoHolder.getUnits()[CUID])
1777 ->getOrCreateSourceID(Fn, Dir);
1779 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1783 //===----------------------------------------------------------------------===//
1785 //===----------------------------------------------------------------------===//
1787 // Compute the size and offset of a DIE. The offset is relative to start of the
1788 // CU. It returns the offset after laying out the DIE.
1789 unsigned DwarfFile::computeSizeAndOffset(DIE &Die, unsigned Offset) {
1790 // Record the abbreviation.
1791 assignAbbrevNumber(Die.getAbbrev());
1793 // Get the abbreviation for this DIE.
1794 const DIEAbbrev &Abbrev = Die.getAbbrev();
1797 Die.setOffset(Offset);
1799 // Start the size with the size of abbreviation code.
1800 Offset += getULEB128Size(Die.getAbbrevNumber());
1802 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1803 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1805 // Size the DIE attribute values.
1806 for (unsigned i = 0, N = Values.size(); i < N; ++i)
1807 // Size attribute value.
1808 Offset += Values[i]->SizeOf(Asm, AbbrevData[i].getForm());
1810 // Get the children.
1811 const auto &Children = Die.getChildren();
1813 // Size the DIE children if any.
1814 if (!Children.empty()) {
1815 assert(Abbrev.hasChildren() && "Children flag not set");
1817 for (auto &Child : Children)
1818 Offset = computeSizeAndOffset(*Child, Offset);
1820 // End of children marker.
1821 Offset += sizeof(int8_t);
1824 Die.setSize(Offset - Die.getOffset());
1828 // Compute the size and offset for each DIE.
1829 void DwarfFile::computeSizeAndOffsets() {
1830 // Offset from the first CU in the debug info section is 0 initially.
1831 unsigned SecOffset = 0;
1833 // Iterate over each compile unit and set the size and offsets for each
1834 // DIE within each compile unit. All offsets are CU relative.
1835 for (DwarfUnit *TheU : CUs) {
1836 TheU->setDebugInfoOffset(SecOffset);
1838 // CU-relative offset is reset to 0 here.
1839 unsigned Offset = sizeof(int32_t) + // Length of Unit Info
1840 TheU->getHeaderSize(); // Unit-specific headers
1842 // EndOffset here is CU-relative, after laying out
1843 // all of the CU DIE.
1844 unsigned EndOffset = computeSizeAndOffset(*TheU->getUnitDie(), Offset);
1845 SecOffset += EndOffset;
1849 // Emit initial Dwarf sections with a label at the start of each one.
1850 void DwarfDebug::emitSectionLabels() {
1851 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1853 // Dwarf sections base addresses.
1854 DwarfInfoSectionSym =
1855 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1856 if (useSplitDwarf())
1857 DwarfInfoDWOSectionSym =
1858 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1859 DwarfAbbrevSectionSym =
1860 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1861 if (useSplitDwarf())
1862 DwarfAbbrevDWOSectionSym = emitSectionSym(
1863 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1864 if (GenerateARangeSection)
1865 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1867 DwarfLineSectionSym =
1868 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1869 if (GenerateGnuPubSections) {
1870 DwarfGnuPubNamesSectionSym =
1871 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1872 DwarfGnuPubTypesSectionSym =
1873 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1874 } else if (HasDwarfPubSections) {
1875 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1876 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1879 DwarfStrSectionSym =
1880 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1881 if (useSplitDwarf()) {
1882 DwarfStrDWOSectionSym =
1883 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1884 DwarfAddrSectionSym =
1885 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1886 DwarfDebugLocSectionSym =
1887 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1889 DwarfDebugLocSectionSym =
1890 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1891 DwarfDebugRangeSectionSym =
1892 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1895 // Recursively emits a debug information entry.
1896 void DwarfDebug::emitDIE(DIE &Die) {
1897 // Get the abbreviation for this DIE.
1898 const DIEAbbrev &Abbrev = Die.getAbbrev();
1900 // Emit the code (index) for the abbreviation.
1901 if (Asm->isVerbose())
1902 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1903 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1904 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1905 dwarf::TagString(Abbrev.getTag()));
1906 Asm->EmitULEB128(Abbrev.getNumber());
1908 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1909 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1911 // Emit the DIE attribute values.
1912 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1913 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1914 dwarf::Form Form = AbbrevData[i].getForm();
1915 assert(Form && "Too many attributes for DIE (check abbreviation)");
1917 if (Asm->isVerbose()) {
1918 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1919 if (Attr == dwarf::DW_AT_accessibility)
1920 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1921 cast<DIEInteger>(Values[i])->getValue()));
1924 // Emit an attribute using the defined form.
1925 Values[i]->EmitValue(Asm, Form);
1928 // Emit the DIE children if any.
1929 if (Abbrev.hasChildren()) {
1930 for (auto &Child : Die.getChildren())
1933 Asm->OutStreamer.AddComment("End Of Children Mark");
1938 // Emit the various dwarf units to the unit section USection with
1939 // the abbreviations going into ASection.
1940 void DwarfFile::emitUnits(DwarfDebug *DD, const MCSymbol *ASectionSym) {
1941 for (DwarfUnit *TheU : CUs) {
1942 DIE *Die = TheU->getUnitDie();
1943 const MCSection *USection = TheU->getSection();
1944 Asm->OutStreamer.SwitchSection(USection);
1946 // Emit the compile units header.
1947 Asm->OutStreamer.EmitLabel(TheU->getLabelBegin());
1949 // Emit size of content not including length itself
1950 Asm->OutStreamer.AddComment("Length of Unit");
1951 Asm->EmitInt32(TheU->getHeaderSize() + Die->getSize());
1953 TheU->emitHeader(ASectionSym);
1956 Asm->OutStreamer.EmitLabel(TheU->getLabelEnd());
1960 // Emit the debug info section.
1961 void DwarfDebug::emitDebugInfo() {
1962 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1964 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1967 // Emit the abbreviation section.
1968 void DwarfDebug::emitAbbreviations() {
1969 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1971 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1974 void DwarfFile::emitAbbrevs(const MCSection *Section) {
1975 // Check to see if it is worth the effort.
1976 if (!Abbreviations.empty()) {
1977 // Start the debug abbrev section.
1978 Asm->OutStreamer.SwitchSection(Section);
1980 // For each abbrevation.
1981 for (const DIEAbbrev *Abbrev : Abbreviations) {
1982 // Emit the abbrevations code (base 1 index.)
1983 Asm->EmitULEB128(Abbrev->getNumber(), "Abbreviation Code");
1985 // Emit the abbreviations data.
1989 // Mark end of abbreviations.
1990 Asm->EmitULEB128(0, "EOM(3)");
1994 // Emit the last address of the section and the end of the line matrix.
1995 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1996 // Define last address of section.
1997 Asm->OutStreamer.AddComment("Extended Op");
2000 Asm->OutStreamer.AddComment("Op size");
2001 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
2002 Asm->OutStreamer.AddComment("DW_LNE_set_address");
2003 Asm->EmitInt8(dwarf::DW_LNE_set_address);
2005 Asm->OutStreamer.AddComment("Section end label");
2007 Asm->OutStreamer.EmitSymbolValue(
2008 Asm->GetTempSymbol("section_end", SectionEnd),
2009 Asm->getDataLayout().getPointerSize());
2011 // Mark end of matrix.
2012 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
2018 // Emit visible names into a hashed accelerator table section.
2019 void DwarfDebug::emitAccelNames() {
2021 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2022 for (DwarfUnit *TheU : getUnits()) {
2023 for (const auto &GI : TheU->getAccelNames()) {
2024 StringRef Name = GI.getKey();
2025 for (const DIE *D : GI.second)
2026 AT.AddName(Name, D);
2030 AT.FinalizeTable(Asm, "Names");
2031 Asm->OutStreamer.SwitchSection(
2032 Asm->getObjFileLowering().getDwarfAccelNamesSection());
2033 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
2034 Asm->OutStreamer.EmitLabel(SectionBegin);
2036 // Emit the full data.
2037 AT.Emit(Asm, SectionBegin, &InfoHolder);
2040 // Emit objective C classes and categories into a hashed accelerator table
2042 void DwarfDebug::emitAccelObjC() {
2044 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2045 for (DwarfUnit *TheU : getUnits()) {
2046 for (const auto &GI : TheU->getAccelObjC()) {
2047 StringRef Name = GI.getKey();
2048 for (const DIE *D : GI.second)
2049 AT.AddName(Name, D);
2053 AT.FinalizeTable(Asm, "ObjC");
2054 Asm->OutStreamer.SwitchSection(
2055 Asm->getObjFileLowering().getDwarfAccelObjCSection());
2056 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
2057 Asm->OutStreamer.EmitLabel(SectionBegin);
2059 // Emit the full data.
2060 AT.Emit(Asm, SectionBegin, &InfoHolder);
2063 // Emit namespace dies into a hashed accelerator table.
2064 void DwarfDebug::emitAccelNamespaces() {
2066 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2067 for (DwarfUnit *TheU : getUnits()) {
2068 for (const auto &GI : TheU->getAccelNamespace()) {
2069 StringRef Name = GI.getKey();
2070 for (const DIE *D : GI.second)
2071 AT.AddName(Name, D);
2075 AT.FinalizeTable(Asm, "namespac");
2076 Asm->OutStreamer.SwitchSection(
2077 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
2078 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
2079 Asm->OutStreamer.EmitLabel(SectionBegin);
2081 // Emit the full data.
2082 AT.Emit(Asm, SectionBegin, &InfoHolder);
2085 // Emit type dies into a hashed accelerator table.
2086 void DwarfDebug::emitAccelTypes() {
2087 std::vector<DwarfAccelTable::Atom> Atoms;
2089 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2091 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2));
2093 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1));
2094 DwarfAccelTable AT(Atoms);
2095 for (DwarfUnit *TheU : getUnits()) {
2096 for (const auto &GI : TheU->getAccelTypes()) {
2097 StringRef Name = GI.getKey();
2098 for (const auto &DI : GI.second)
2099 AT.AddName(Name, DI.first, DI.second);
2103 AT.FinalizeTable(Asm, "types");
2104 Asm->OutStreamer.SwitchSection(
2105 Asm->getObjFileLowering().getDwarfAccelTypesSection());
2106 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
2107 Asm->OutStreamer.EmitLabel(SectionBegin);
2109 // Emit the full data.
2110 AT.Emit(Asm, SectionBegin, &InfoHolder);
2113 // Public name handling.
2114 // The format for the various pubnames:
2116 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
2117 // for the DIE that is named.
2119 // gnu pubnames - offset/index value/name tuples where the offset is the offset
2120 // into the CU and the index value is computed according to the type of value
2121 // for the DIE that is named.
2123 // For type units the offset is the offset of the skeleton DIE. For split dwarf
2124 // it's the offset within the debug_info/debug_types dwo section, however, the
2125 // reference in the pubname header doesn't change.
2127 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
2128 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
2130 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
2132 // We could have a specification DIE that has our most of our knowledge,
2133 // look for that now.
2134 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
2136 DIE *SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
2137 if (SpecDIE->findAttribute(dwarf::DW_AT_external))
2138 Linkage = dwarf::GIEL_EXTERNAL;
2139 } else if (Die->findAttribute(dwarf::DW_AT_external))
2140 Linkage = dwarf::GIEL_EXTERNAL;
2142 switch (Die->getTag()) {
2143 case dwarf::DW_TAG_class_type:
2144 case dwarf::DW_TAG_structure_type:
2145 case dwarf::DW_TAG_union_type:
2146 case dwarf::DW_TAG_enumeration_type:
2147 return dwarf::PubIndexEntryDescriptor(
2148 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
2149 ? dwarf::GIEL_STATIC
2150 : dwarf::GIEL_EXTERNAL);
2151 case dwarf::DW_TAG_typedef:
2152 case dwarf::DW_TAG_base_type:
2153 case dwarf::DW_TAG_subrange_type:
2154 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
2155 case dwarf::DW_TAG_namespace:
2156 return dwarf::GIEK_TYPE;
2157 case dwarf::DW_TAG_subprogram:
2158 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
2159 case dwarf::DW_TAG_constant:
2160 case dwarf::DW_TAG_variable:
2161 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
2162 case dwarf::DW_TAG_enumerator:
2163 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
2164 dwarf::GIEL_STATIC);
2166 return dwarf::GIEK_NONE;
2170 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
2172 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
2173 const MCSection *PSec =
2174 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
2175 : Asm->getObjFileLowering().getDwarfPubNamesSection();
2177 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
2180 void DwarfDebug::emitDebugPubSection(
2181 bool GnuStyle, const MCSection *PSec, StringRef Name,
2182 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
2183 for (const auto &NU : CUMap) {
2184 DwarfCompileUnit *TheU = NU.second;
2186 const auto &Globals = (TheU->*Accessor)();
2188 if (Globals.empty())
2191 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2193 unsigned ID = TheU->getUniqueID();
2195 // Start the dwarf pubnames section.
2196 Asm->OutStreamer.SwitchSection(PSec);
2199 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2200 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2201 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2202 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2204 Asm->OutStreamer.EmitLabel(BeginLabel);
2206 Asm->OutStreamer.AddComment("DWARF Version");
2207 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2209 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2210 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2212 Asm->OutStreamer.AddComment("Compilation Unit Length");
2213 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2215 // Emit the pubnames for this compilation unit.
2216 for (const auto &GI : Globals) {
2217 const char *Name = GI.getKeyData();
2218 const DIE *Entity = GI.second;
2220 Asm->OutStreamer.AddComment("DIE offset");
2221 Asm->EmitInt32(Entity->getOffset());
2224 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2225 Asm->OutStreamer.AddComment(
2226 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2227 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2228 Asm->EmitInt8(Desc.toBits());
2231 Asm->OutStreamer.AddComment("External Name");
2232 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2235 Asm->OutStreamer.AddComment("End Mark");
2237 Asm->OutStreamer.EmitLabel(EndLabel);
2241 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2242 const MCSection *PSec =
2243 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2244 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2246 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2249 // Emit strings into a string section.
2250 void DwarfFile::emitStrings(const MCSection *StrSection,
2251 const MCSection *OffsetSection = NULL,
2252 const MCSymbol *StrSecSym = NULL) {
2254 if (StringPool.empty())
2257 // Start the dwarf str section.
2258 Asm->OutStreamer.SwitchSection(StrSection);
2260 // Get all of the string pool entries and put them in an array by their ID so
2261 // we can sort them.
2262 SmallVector<std::pair<unsigned, const StrPool::value_type *>, 64 > Entries;
2264 for (const auto &I : StringPool)
2265 Entries.push_back(std::make_pair(I.second.second, &I));
2267 array_pod_sort(Entries.begin(), Entries.end());
2269 for (const auto &Entry : Entries) {
2270 // Emit a label for reference from debug information entries.
2271 Asm->OutStreamer.EmitLabel(Entry.second->getValue().first);
2273 // Emit the string itself with a terminating null byte.
2274 Asm->OutStreamer.EmitBytes(StringRef(Entry.second->getKeyData(),
2275 Entry.second->getKeyLength() + 1));
2278 // If we've got an offset section go ahead and emit that now as well.
2279 if (OffsetSection) {
2280 Asm->OutStreamer.SwitchSection(OffsetSection);
2281 unsigned offset = 0;
2282 unsigned size = 4; // FIXME: DWARF64 is 8.
2283 for (const auto &Entry : Entries) {
2284 Asm->OutStreamer.EmitIntValue(offset, size);
2285 offset += Entry.second->getKeyLength() + 1;
2290 // Emit addresses into the section given.
2291 void DwarfFile::emitAddresses(const MCSection *AddrSection) {
2293 if (AddressPool.empty())
2296 // Start the dwarf addr section.
2297 Asm->OutStreamer.SwitchSection(AddrSection);
2299 // Order the address pool entries by ID
2300 SmallVector<const MCExpr *, 64> Entries(AddressPool.size());
2302 for (const auto &I : AddressPool)
2303 Entries[I.second.Number] =
2305 ? Asm->getObjFileLowering().getDebugThreadLocalSymbol(I.first)
2306 : MCSymbolRefExpr::Create(I.first, Asm->OutContext);
2308 for (const MCExpr *Entry : Entries)
2309 Asm->OutStreamer.EmitValue(Entry, Asm->getDataLayout().getPointerSize());
2312 // Emit visible names into a debug str section.
2313 void DwarfDebug::emitDebugStr() {
2314 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2315 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2318 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2319 const DebugLocEntry &Entry) {
2320 DIVariable DV(Entry.getVariable());
2321 if (Entry.isInt()) {
2322 DIBasicType BTy(resolve(DV.getType()));
2323 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2324 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2325 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2326 Streamer.EmitSLEB128(Entry.getInt());
2328 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2329 Streamer.EmitULEB128(Entry.getInt());
2331 } else if (Entry.isLocation()) {
2332 MachineLocation Loc = Entry.getLoc();
2333 if (!DV.hasComplexAddress())
2335 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2337 // Complex address entry.
2338 unsigned N = DV.getNumAddrElements();
2340 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2341 if (Loc.getOffset()) {
2343 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2344 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2345 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2346 Streamer.EmitSLEB128(DV.getAddrElement(1));
2348 // If first address element is OpPlus then emit
2349 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2350 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2351 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2355 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2358 // Emit remaining complex address elements.
2359 for (; i < N; ++i) {
2360 uint64_t Element = DV.getAddrElement(i);
2361 if (Element == DIBuilder::OpPlus) {
2362 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2363 Streamer.EmitULEB128(DV.getAddrElement(++i));
2364 } else if (Element == DIBuilder::OpDeref) {
2366 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2368 llvm_unreachable("unknown Opcode found in complex address");
2372 // else ... ignore constant fp. There is not any good way to
2373 // to represent them here in dwarf.
2377 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2378 Asm->OutStreamer.AddComment("Loc expr size");
2379 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2380 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2381 Asm->EmitLabelDifference(end, begin, 2);
2382 Asm->OutStreamer.EmitLabel(begin);
2384 APByteStreamer Streamer(*Asm);
2385 emitDebugLocEntry(Streamer, Entry);
2387 Asm->OutStreamer.EmitLabel(end);
2390 // Emit locations into the debug loc section.
2391 void DwarfDebug::emitDebugLoc() {
2392 // Start the dwarf loc section.
2393 Asm->OutStreamer.SwitchSection(
2394 Asm->getObjFileLowering().getDwarfLocSection());
2395 unsigned char Size = Asm->getDataLayout().getPointerSize();
2396 for (const auto &DebugLoc : DotDebugLocEntries) {
2397 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2398 for (const auto &Entry : DebugLoc.List) {
2399 // Set up the range. This range is relative to the entry point of the
2400 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2401 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2402 const DwarfCompileUnit *CU = Entry.getCU();
2403 if (CU->getRanges().size() == 1) {
2404 // Grab the begin symbol from the first range as our base.
2405 const MCSymbol *Base = CU->getRanges()[0].getStart();
2406 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2407 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2409 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2410 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2413 emitDebugLocEntryLocation(Entry);
2415 Asm->OutStreamer.EmitIntValue(0, Size);
2416 Asm->OutStreamer.EmitIntValue(0, Size);
2420 void DwarfDebug::emitDebugLocDWO() {
2421 Asm->OutStreamer.SwitchSection(
2422 Asm->getObjFileLowering().getDwarfLocDWOSection());
2423 for (const auto &DebugLoc : DotDebugLocEntries) {
2424 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2425 for (const auto &Entry : DebugLoc.List) {
2426 // Just always use start_length for now - at least that's one address
2427 // rather than two. We could get fancier and try to, say, reuse an
2428 // address we know we've emitted elsewhere (the start of the function?
2429 // The start of the CU or CU subrange that encloses this range?)
2430 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2431 unsigned idx = InfoHolder.getAddrPoolIndex(Entry.getBeginSym());
2432 Asm->EmitULEB128(idx);
2433 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2435 emitDebugLocEntryLocation(Entry);
2437 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2442 const MCSymbol *Start, *End;
2445 // Emit a debug aranges section, containing a CU lookup for any
2446 // address we can tie back to a CU.
2447 void DwarfDebug::emitDebugARanges() {
2448 // Start the dwarf aranges section.
2449 Asm->OutStreamer.SwitchSection(
2450 Asm->getObjFileLowering().getDwarfARangesSection());
2452 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan> > SpansType;
2456 // Build a list of sections used.
2457 std::vector<const MCSection *> Sections;
2458 for (const auto &it : SectionMap) {
2459 const MCSection *Section = it.first;
2460 Sections.push_back(Section);
2463 // Sort the sections into order.
2464 // This is only done to ensure consistent output order across different runs.
2465 std::sort(Sections.begin(), Sections.end(), SectionSort);
2467 // Build a set of address spans, sorted by CU.
2468 for (const MCSection *Section : Sections) {
2469 auto &List = SectionMap[Section];
2470 if (List.size() < 2)
2473 // Sort the symbols by offset within the section.
2474 std::sort(List.begin(), List.end(),
2475 [&](const SymbolCU &A, const SymbolCU &B) {
2476 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2477 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2479 // Symbols with no order assigned should be placed at the end.
2480 // (e.g. section end labels)
2488 // If we have no section (e.g. common), just write out
2489 // individual spans for each symbol.
2490 if (Section == NULL) {
2491 for (const SymbolCU &Cur : List) {
2493 Span.Start = Cur.Sym;
2496 Spans[Cur.CU].push_back(Span);
2499 // Build spans between each label.
2500 const MCSymbol *StartSym = List[0].Sym;
2501 for (size_t n = 1, e = List.size(); n < e; n++) {
2502 const SymbolCU &Prev = List[n - 1];
2503 const SymbolCU &Cur = List[n];
2505 // Try and build the longest span we can within the same CU.
2506 if (Cur.CU != Prev.CU) {
2508 Span.Start = StartSym;
2510 Spans[Prev.CU].push_back(Span);
2517 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2519 // Build a list of CUs used.
2520 std::vector<DwarfCompileUnit *> CUs;
2521 for (const auto &it : Spans) {
2522 DwarfCompileUnit *CU = it.first;
2526 // Sort the CU list (again, to ensure consistent output order).
2527 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2528 return A->getUniqueID() < B->getUniqueID();
2531 // Emit an arange table for each CU we used.
2532 for (DwarfCompileUnit *CU : CUs) {
2533 std::vector<ArangeSpan> &List = Spans[CU];
2535 // Emit size of content not including length itself.
2536 unsigned ContentSize =
2537 sizeof(int16_t) + // DWARF ARange version number
2538 sizeof(int32_t) + // Offset of CU in the .debug_info section
2539 sizeof(int8_t) + // Pointer Size (in bytes)
2540 sizeof(int8_t); // Segment Size (in bytes)
2542 unsigned TupleSize = PtrSize * 2;
2544 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2546 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2548 ContentSize += Padding;
2549 ContentSize += (List.size() + 1) * TupleSize;
2551 // For each compile unit, write the list of spans it covers.
2552 Asm->OutStreamer.AddComment("Length of ARange Set");
2553 Asm->EmitInt32(ContentSize);
2554 Asm->OutStreamer.AddComment("DWARF Arange version number");
2555 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2556 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2557 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2558 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2559 Asm->EmitInt8(PtrSize);
2560 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2563 Asm->OutStreamer.EmitFill(Padding, 0xff);
2565 for (const ArangeSpan &Span : List) {
2566 Asm->EmitLabelReference(Span.Start, PtrSize);
2568 // Calculate the size as being from the span start to it's end.
2570 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2572 // For symbols without an end marker (e.g. common), we
2573 // write a single arange entry containing just that one symbol.
2574 uint64_t Size = SymSize[Span.Start];
2578 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2582 Asm->OutStreamer.AddComment("ARange terminator");
2583 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2584 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2588 // Emit visible names into a debug ranges section.
2589 void DwarfDebug::emitDebugRanges() {
2590 // Start the dwarf ranges section.
2591 Asm->OutStreamer.SwitchSection(
2592 Asm->getObjFileLowering().getDwarfRangesSection());
2594 // Size for our labels.
2595 unsigned char Size = Asm->getDataLayout().getPointerSize();
2597 // Grab the specific ranges for the compile units in the module.
2598 for (const auto &I : CUMap) {
2599 DwarfCompileUnit *TheCU = I.second;
2601 // Emit a symbol so we can find the beginning of our ranges.
2602 Asm->OutStreamer.EmitLabel(TheCU->getLabelRange());
2604 // Iterate over the misc ranges for the compile units in the module.
2605 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2606 // Emit our symbol so we can find the beginning of the range.
2607 Asm->OutStreamer.EmitLabel(List.getSym());
2609 for (const RangeSpan &Range : List.getRanges()) {
2610 const MCSymbol *Begin = Range.getStart();
2611 const MCSymbol *End = Range.getEnd();
2612 assert(Begin && "Range without a begin symbol?");
2613 assert(End && "Range without an end symbol?");
2614 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2615 Asm->OutStreamer.EmitSymbolValue(End, Size);
2618 // And terminate the list with two 0 values.
2619 Asm->OutStreamer.EmitIntValue(0, Size);
2620 Asm->OutStreamer.EmitIntValue(0, Size);
2623 // Now emit a range for the CU itself.
2624 if (TheCU->getRanges().size() > 1) {
2625 Asm->OutStreamer.EmitLabel(
2626 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2627 for (const RangeSpan &Range : TheCU->getRanges()) {
2628 const MCSymbol *Begin = Range.getStart();
2629 const MCSymbol *End = Range.getEnd();
2630 assert(Begin && "Range without a begin symbol?");
2631 assert(End && "Range without an end symbol?");
2632 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2633 Asm->OutStreamer.EmitSymbolValue(End, Size);
2635 // And terminate the list with two 0 values.
2636 Asm->OutStreamer.EmitIntValue(0, Size);
2637 Asm->OutStreamer.EmitIntValue(0, Size);
2642 // DWARF5 Experimental Separate Dwarf emitters.
2644 void DwarfDebug::initSkeletonUnit(const DwarfUnit *U, DIE *Die,
2646 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2647 U->getCUNode().getSplitDebugFilename());
2649 if (!CompilationDir.empty())
2650 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2652 addGnuPubAttributes(NewU, Die);
2654 SkeletonHolder.addUnit(NewU);
2657 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2658 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2659 // DW_AT_addr_base, DW_AT_ranges_base.
2660 DwarfCompileUnit *DwarfDebug::constructSkeletonCU(const DwarfCompileUnit *CU) {
2662 DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
2663 DwarfCompileUnit *NewCU = new DwarfCompileUnit(
2664 CU->getUniqueID(), Die, CU->getCUNode(), Asm, this, &SkeletonHolder);
2665 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2666 DwarfInfoSectionSym);
2668 NewCU->initStmtList(DwarfLineSectionSym);
2670 initSkeletonUnit(CU, Die, NewCU);
2675 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2677 DwarfTypeUnit *DwarfDebug::constructSkeletonTU(DwarfTypeUnit *TU) {
2678 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2679 *SkeletonHolder.getUnits()[TU->getCU().getUniqueID()]);
2681 DIE *Die = new DIE(dwarf::DW_TAG_type_unit);
2682 DwarfTypeUnit *NewTU =
2683 new DwarfTypeUnit(TU->getUniqueID(), Die, CU, Asm, this, &SkeletonHolder);
2684 NewTU->setTypeSignature(TU->getTypeSignature());
2685 NewTU->setType(NULL);
2687 Asm->getObjFileLowering().getDwarfTypesSection(TU->getTypeSignature()));
2689 initSkeletonUnit(TU, Die, NewTU);
2693 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2694 // compile units that would normally be in debug_info.
2695 void DwarfDebug::emitDebugInfoDWO() {
2696 assert(useSplitDwarf() && "No split dwarf debug info?");
2697 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2698 // emit relocations into the dwo file.
2699 InfoHolder.emitUnits(this, /* AbbrevSymbol */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);