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 "DwarfUnit.h"
19 #include "llvm/ADT/STLExtras.h"
20 #include "llvm/ADT/Statistic.h"
21 #include "llvm/ADT/StringExtras.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineModuleInfo.h"
25 #include "llvm/IR/Constants.h"
26 #include "llvm/IR/DIBuilder.h"
27 #include "llvm/IR/DataLayout.h"
28 #include "llvm/IR/DebugInfo.h"
29 #include "llvm/IR/Instructions.h"
30 #include "llvm/IR/Module.h"
31 #include "llvm/IR/ValueHandle.h"
32 #include "llvm/MC/MCAsmInfo.h"
33 #include "llvm/MC/MCSection.h"
34 #include "llvm/MC/MCStreamer.h"
35 #include "llvm/MC/MCSymbol.h"
36 #include "llvm/Support/CommandLine.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/Dwarf.h"
39 #include "llvm/Support/Endian.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 const char *const DWARFGroupName = "DWARF Emission";
103 static const char *const DbgTimerName = "DWARF Debug Writer";
105 //===----------------------------------------------------------------------===//
107 /// resolve - Look in the DwarfDebug map for the MDNode that
108 /// corresponds to the reference.
109 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
110 return DD->resolve(Ref);
113 bool DbgVariable::isBlockByrefVariable() const {
114 assert(Var.isVariable() && "Invalid complex DbgVariable!");
115 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
118 DIType DbgVariable::getType() const {
119 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
120 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
121 // addresses instead.
122 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
123 /* Byref variables, in Blocks, are declared by the programmer as
124 "SomeType VarName;", but the compiler creates a
125 __Block_byref_x_VarName struct, and gives the variable VarName
126 either the struct, or a pointer to the struct, as its type. This
127 is necessary for various behind-the-scenes things the compiler
128 needs to do with by-reference variables in blocks.
130 However, as far as the original *programmer* is concerned, the
131 variable should still have type 'SomeType', as originally declared.
133 The following function dives into the __Block_byref_x_VarName
134 struct to find the original type of the variable. This will be
135 passed back to the code generating the type for the Debug
136 Information Entry for the variable 'VarName'. 'VarName' will then
137 have the original type 'SomeType' in its debug information.
139 The original type 'SomeType' will be the type of the field named
140 'VarName' inside the __Block_byref_x_VarName struct.
142 NOTE: In order for this to not completely fail on the debugger
143 side, the Debug Information Entry for the variable VarName needs to
144 have a DW_AT_location that tells the debugger how to unwind through
145 the pointers and __Block_byref_x_VarName struct to find the actual
146 value of the variable. The function addBlockByrefType does this. */
148 uint16_t tag = Ty.getTag();
150 if (tag == dwarf::DW_TAG_pointer_type)
151 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
153 DIArray Elements = DICompositeType(subType).getTypeArray();
154 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
155 DIDerivedType DT(Elements.getElement(i));
156 if (getName() == DT.getName())
157 return (resolve(DT.getTypeDerivedFrom()));
163 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
164 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
165 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
166 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
168 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
169 : Asm(A), MMI(Asm->MMI), FirstCU(nullptr), PrevLabel(nullptr),
170 GlobalRangeCount(0), InfoHolder(A, "info_string", DIEValueAllocator),
171 UsedNonDefaultText(false),
172 SkeletonHolder(A, "skel_string", DIEValueAllocator),
173 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
174 dwarf::DW_FORM_data4)),
175 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
176 dwarf::DW_FORM_data4)),
177 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
178 dwarf::DW_FORM_data4)),
179 AccelTypes(TypeAtoms) {
181 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = nullptr;
182 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = nullptr;
183 DwarfLineSectionSym = nullptr;
184 DwarfAddrSectionSym = nullptr;
185 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = nullptr;
186 FunctionBeginSym = FunctionEndSym = nullptr;
190 // Turn on accelerator tables for Darwin by default, pubnames by
191 // default for non-Darwin, and handle split dwarf.
192 bool IsDarwin = Triple(A->getTargetTriple()).isOSDarwin();
194 if (DwarfAccelTables == Default)
195 HasDwarfAccelTables = IsDarwin;
197 HasDwarfAccelTables = DwarfAccelTables == Enable;
199 if (SplitDwarf == Default)
200 HasSplitDwarf = false;
202 HasSplitDwarf = SplitDwarf == Enable;
204 if (DwarfPubSections == Default)
205 HasDwarfPubSections = !IsDarwin;
207 HasDwarfPubSections = DwarfPubSections == Enable;
209 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
210 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
211 : MMI->getModule()->getDwarfVersion();
213 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
216 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
221 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
222 DwarfDebug::~DwarfDebug() { }
224 // Switch to the specified MCSection and emit an assembler
225 // temporary label to it if SymbolStem is specified.
226 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
227 const char *SymbolStem = nullptr) {
228 Asm->OutStreamer.SwitchSection(Section);
232 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
233 Asm->OutStreamer.EmitLabel(TmpSym);
237 static bool isObjCClass(StringRef Name) {
238 return Name.startswith("+") || Name.startswith("-");
241 static bool hasObjCCategory(StringRef Name) {
242 if (!isObjCClass(Name))
245 return Name.find(") ") != StringRef::npos;
248 static void getObjCClassCategory(StringRef In, StringRef &Class,
249 StringRef &Category) {
250 if (!hasObjCCategory(In)) {
251 Class = In.slice(In.find('[') + 1, In.find(' '));
256 Class = In.slice(In.find('[') + 1, In.find('('));
257 Category = In.slice(In.find('[') + 1, In.find(' '));
261 static StringRef getObjCMethodName(StringRef In) {
262 return In.slice(In.find(' ') + 1, In.find(']'));
265 // Helper for sorting sections into a stable output order.
266 static bool SectionSort(const MCSection *A, const MCSection *B) {
267 std::string LA = (A ? A->getLabelBeginName() : "");
268 std::string LB = (B ? B->getLabelBeginName() : "");
272 // Add the various names to the Dwarf accelerator table names.
273 // TODO: Determine whether or not we should add names for programs
274 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
275 // is only slightly different than the lookup of non-standard ObjC names.
276 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
277 if (!SP.isDefinition())
279 addAccelName(SP.getName(), Die);
281 // If the linkage name is different than the name, go ahead and output
282 // that as well into the name table.
283 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
284 addAccelName(SP.getLinkageName(), Die);
286 // If this is an Objective-C selector name add it to the ObjC accelerator
288 if (isObjCClass(SP.getName())) {
289 StringRef Class, Category;
290 getObjCClassCategory(SP.getName(), Class, Category);
291 addAccelObjC(Class, Die);
293 addAccelObjC(Category, Die);
294 // Also add the base method name to the name table.
295 addAccelName(getObjCMethodName(SP.getName()), Die);
299 /// isSubprogramContext - Return true if Context is either a subprogram
300 /// or another context nested inside a subprogram.
301 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
304 DIDescriptor D(Context);
305 if (D.isSubprogram())
308 return isSubprogramContext(resolve(DIType(Context).getContext()));
312 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
313 // and DW_AT_high_pc attributes. If there are global variables in this
314 // scope then create and insert DIEs for these variables.
315 DIE &DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
317 DIE *SPDie = SPCU.getOrCreateSubprogramDIE(SP);
319 attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
321 const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
322 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
323 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
325 // Add name to the name table, we do this here because we're guaranteed
326 // to have concrete versions of our DW_TAG_subprogram nodes.
327 addSubprogramNames(SP, *SPDie);
332 /// Check whether we should create a DIE for the given Scope, return true
333 /// if we don't create a DIE (the corresponding DIE is null).
334 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
335 if (Scope->isAbstractScope())
338 // We don't create a DIE if there is no Range.
339 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
343 if (Ranges.size() > 1)
346 // We don't create a DIE if we have a single Range and the end label
348 SmallVectorImpl<InsnRange>::const_iterator RI = Ranges.begin();
349 MCSymbol *End = getLabelAfterInsn(RI->second);
353 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
354 dwarf::Attribute A, const MCSymbol *L,
355 const MCSymbol *Sec) {
356 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
357 U.addSectionLabel(D, A, L);
359 U.addSectionDelta(D, A, L, Sec);
362 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
363 const SmallVectorImpl<InsnRange> &Range) {
364 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
365 // emitting it appropriately.
366 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
368 // Under fission, ranges are specified by constant offsets relative to the
369 // CU's DW_AT_GNU_ranges_base.
371 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
372 DwarfDebugRangeSectionSym);
374 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
375 DwarfDebugRangeSectionSym);
377 RangeSpanList List(RangeSym);
378 for (const InsnRange &R : Range) {
379 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
380 List.addRange(std::move(Span));
383 // Add the range list to the set of ranges to be emitted.
384 TheCU.addRangeList(std::move(List));
387 void DwarfDebug::attachRangesOrLowHighPC(DwarfCompileUnit &TheCU, DIE &Die,
388 const SmallVectorImpl<InsnRange> &Ranges) {
389 assert(!Ranges.empty());
390 if (Ranges.size() == 1)
391 attachLowHighPC(TheCU, Die, getLabelBeforeInsn(Ranges.front().first),
392 getLabelAfterInsn(Ranges.front().second));
394 addScopeRangeList(TheCU, Die, Ranges);
397 // Construct new DW_TAG_lexical_block for this scope and attach
398 // DW_AT_low_pc/DW_AT_high_pc labels.
400 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
401 LexicalScope *Scope) {
402 if (isLexicalScopeDIENull(Scope))
405 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
406 if (Scope->isAbstractScope())
409 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
414 // This scope represents inlined body of a function. Construct DIE to
415 // represent this concrete inlined copy of the function.
417 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
418 LexicalScope *Scope) {
419 assert(Scope->getScopeNode());
420 DIScope DS(Scope->getScopeNode());
421 DISubprogram InlinedSP = getDISubprogram(DS);
422 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
423 // was inlined from another compile unit.
424 DIE *OriginDIE = AbstractSPDies[InlinedSP];
425 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
427 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
428 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
430 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
432 InlinedSubprogramDIEs.insert(OriginDIE);
434 // Add the call site information to the DIE.
435 DILocation DL(Scope->getInlinedAt());
436 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
437 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
438 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
440 // Add name to the name table, we do this here because we're guaranteed
441 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
442 addSubprogramNames(InlinedSP, *ScopeDIE);
447 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
449 const LexicalScope &Scope,
450 DIE *&ObjectPointer) {
451 auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
452 if (DV.isObjectPointer())
453 ObjectPointer = Var.get();
457 DIE *DwarfDebug::createScopeChildrenDIE(
458 DwarfCompileUnit &TheCU, LexicalScope *Scope,
459 SmallVectorImpl<std::unique_ptr<DIE>> &Children) {
460 DIE *ObjectPointer = nullptr;
462 // Collect arguments for current function.
463 if (LScopes.isCurrentFunctionScope(Scope)) {
464 for (DbgVariable *ArgDV : CurrentFnArguments)
467 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
469 // If this is a variadic function, add an unspecified parameter.
470 DISubprogram SP(Scope->getScopeNode());
471 DIArray FnArgs = SP.getType().getTypeArray();
472 if (FnArgs.getElement(FnArgs.getNumElements() - 1)
473 .isUnspecifiedParameter()) {
475 make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
479 // Collect lexical scope children first.
480 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
481 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
483 for (LexicalScope *LS : Scope->getChildren())
484 if (std::unique_ptr<DIE> Nested = constructScopeDIE(TheCU, LS))
485 Children.push_back(std::move(Nested));
486 return ObjectPointer;
489 void DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
490 LexicalScope *Scope, DIE &ScopeDIE) {
491 // We create children when the scope DIE is not null.
492 SmallVector<std::unique_ptr<DIE>, 8> Children;
493 if (DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children))
494 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
497 for (auto &I : Children)
498 ScopeDIE.addChild(std::move(I));
501 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
502 LexicalScope *Scope) {
503 assert(Scope && Scope->getScopeNode());
504 assert(Scope->isAbstractScope());
505 assert(!Scope->getInlinedAt());
507 DISubprogram SP(Scope->getScopeNode());
509 ProcessedSPNodes.insert(SP);
511 DIE *&AbsDef = AbstractSPDies[SP];
515 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
516 // was inlined from another compile unit.
517 DwarfCompileUnit &SPCU = *SPMap[SP];
520 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
521 // the important distinction that the DIDescriptor is not associated with the
522 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
523 // any). It could be refactored to some common utility function.
524 if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
525 ContextDIE = &SPCU.getUnitDie();
526 SPCU.getOrCreateSubprogramDIE(SPDecl);
528 ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
530 // Passing null as the associated DIDescriptor because the abstract definition
531 // shouldn't be found by lookup.
532 AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
534 SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
536 SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
537 createAndAddScopeChildren(SPCU, Scope, *AbsDef);
540 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
541 LexicalScope *Scope) {
542 assert(Scope && Scope->getScopeNode());
543 assert(!Scope->getInlinedAt());
544 assert(!Scope->isAbstractScope());
545 DISubprogram Sub(Scope->getScopeNode());
547 assert(Sub.isSubprogram());
549 ProcessedSPNodes.insert(Sub);
551 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
553 createAndAddScopeChildren(TheCU, Scope, ScopeDIE);
558 // Construct a DIE for this scope.
559 std::unique_ptr<DIE> DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
560 LexicalScope *Scope) {
561 if (!Scope || !Scope->getScopeNode())
564 DIScope DS(Scope->getScopeNode());
566 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
567 "Only handle inlined subprograms here, use "
568 "constructSubprogramScopeDIE for non-inlined "
571 SmallVector<std::unique_ptr<DIE>, 8> Children;
573 // We try to create the scope DIE first, then the children DIEs. This will
574 // avoid creating un-used children then removing them later when we find out
575 // the scope DIE is null.
576 std::unique_ptr<DIE> ScopeDIE;
577 if (Scope->getParent() && DS.isSubprogram()) {
578 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
581 // We create children when the scope DIE is not null.
582 createScopeChildrenDIE(TheCU, Scope, Children);
584 // Early exit when we know the scope DIE is going to be null.
585 if (isLexicalScopeDIENull(Scope))
588 // We create children here when we know the scope DIE is not going to be
589 // null and the children will be added to the scope DIE.
590 createScopeChildrenDIE(TheCU, Scope, Children);
592 // There is no need to emit empty lexical block DIE.
593 std::pair<ImportedEntityMap::const_iterator,
594 ImportedEntityMap::const_iterator> Range =
595 std::equal_range(ScopesWithImportedEntities.begin(),
596 ScopesWithImportedEntities.end(),
597 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
599 if (Children.empty() && Range.first == Range.second)
601 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
602 assert(ScopeDIE && "Scope DIE should not be null.");
603 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
605 constructImportedEntityDIE(TheCU, i->second, *ScopeDIE);
609 for (auto &I : Children)
610 ScopeDIE->addChild(std::move(I));
615 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
616 if (!GenerateGnuPubSections)
619 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
622 // Create new DwarfCompileUnit for the given metadata node with tag
623 // DW_TAG_compile_unit.
624 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
625 StringRef FN = DIUnit.getFilename();
626 CompilationDir = DIUnit.getDirectory();
628 auto OwnedUnit = make_unique<DwarfCompileUnit>(
629 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
630 DwarfCompileUnit &NewCU = *OwnedUnit;
631 DIE &Die = NewCU.getUnitDie();
632 InfoHolder.addUnit(std::move(OwnedUnit));
634 // LTO with assembly output shares a single line table amongst multiple CUs.
635 // To avoid the compilation directory being ambiguous, let the line table
636 // explicitly describe the directory of all files, never relying on the
637 // compilation directory.
638 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
639 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
640 NewCU.getUniqueID(), CompilationDir);
642 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
643 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
644 DIUnit.getLanguage());
645 NewCU.addString(Die, dwarf::DW_AT_name, FN);
647 if (!useSplitDwarf()) {
648 NewCU.initStmtList(DwarfLineSectionSym);
650 // If we're using split dwarf the compilation dir is going to be in the
651 // skeleton CU and so we don't need to duplicate it here.
652 if (!CompilationDir.empty())
653 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
655 addGnuPubAttributes(NewCU, Die);
658 if (DIUnit.isOptimized())
659 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
661 StringRef Flags = DIUnit.getFlags();
663 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
665 if (unsigned RVer = DIUnit.getRunTimeVersion())
666 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
667 dwarf::DW_FORM_data1, RVer);
672 if (useSplitDwarf()) {
673 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
674 DwarfInfoDWOSectionSym);
675 NewCU.setSkeleton(constructSkeletonCU(NewCU));
677 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
678 DwarfInfoSectionSym);
680 CUMap.insert(std::make_pair(DIUnit, &NewCU));
681 CUDieMap.insert(std::make_pair(&Die, &NewCU));
685 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
687 DIImportedEntity Module(N);
688 assert(Module.Verify());
689 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
690 constructImportedEntityDIE(TheCU, Module, *D);
693 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
694 const MDNode *N, DIE &Context) {
695 DIImportedEntity Module(N);
696 assert(Module.Verify());
697 return constructImportedEntityDIE(TheCU, Module, Context);
700 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
701 const DIImportedEntity &Module,
703 assert(Module.Verify() &&
704 "Use one of the MDNode * overloads to handle invalid metadata");
705 DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), Context, Module);
707 DIDescriptor Entity = resolve(Module.getEntity());
708 if (Entity.isNameSpace())
709 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
710 else if (Entity.isSubprogram())
711 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
712 else if (Entity.isType())
713 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
715 EntityDie = TheCU.getDIE(Entity);
716 TheCU.addSourceLine(IMDie, Module.getLineNumber(),
717 Module.getContext().getFilename(),
718 Module.getContext().getDirectory());
719 TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
720 StringRef Name = Module.getName();
722 TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
725 // Emit all Dwarf sections that should come prior to the content. Create
726 // global DIEs and emit initial debug info sections. This is invoked by
727 // the target AsmPrinter.
728 void DwarfDebug::beginModule() {
729 if (DisableDebugInfoPrinting)
732 const Module *M = MMI->getModule();
734 FunctionDIs = makeSubprogramMap(*M);
736 // If module has named metadata anchors then use them, otherwise scan the
737 // module using debug info finder to collect debug info.
738 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
741 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
743 // Emit initial sections so we can reference labels later.
746 SingleCU = CU_Nodes->getNumOperands() == 1;
748 for (MDNode *N : CU_Nodes->operands()) {
749 DICompileUnit CUNode(N);
750 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
751 DIArray ImportedEntities = CUNode.getImportedEntities();
752 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
753 ScopesWithImportedEntities.push_back(std::make_pair(
754 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
755 ImportedEntities.getElement(i)));
756 std::sort(ScopesWithImportedEntities.begin(),
757 ScopesWithImportedEntities.end(), less_first());
758 DIArray GVs = CUNode.getGlobalVariables();
759 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
760 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
761 DIArray SPs = CUNode.getSubprograms();
762 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
763 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
764 DIArray EnumTypes = CUNode.getEnumTypes();
765 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
766 CU.getOrCreateTypeDIE(EnumTypes.getElement(i));
767 DIArray RetainedTypes = CUNode.getRetainedTypes();
768 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
769 DIType Ty(RetainedTypes.getElement(i));
770 // The retained types array by design contains pointers to
771 // MDNodes rather than DIRefs. Unique them here.
772 DIType UniqueTy(resolve(Ty.getRef()));
773 CU.getOrCreateTypeDIE(UniqueTy);
775 // Emit imported_modules last so that the relevant context is already
777 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
778 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
781 // Tell MMI that we have debug info.
782 MMI->setDebugInfoAvailability(true);
784 // Prime section data.
785 SectionMap[Asm->getObjFileLowering().getTextSection()];
788 void DwarfDebug::finishVariableDefinitions() {
789 for (const auto &Var : ConcreteVariables) {
790 DIE *VariableDie = Var->getDIE();
791 // FIXME: There shouldn't be any variables without DIEs.
794 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
795 // in the ConcreteVariables list, rather than looking it up again here.
796 // DIE::getUnit isn't simple - it walks parent pointers, etc.
797 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
799 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
800 if (AbsVar && AbsVar->getDIE()) {
801 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
804 Unit->applyVariableAttributes(*Var, *VariableDie);
808 void DwarfDebug::finishSubprogramDefinitions() {
809 const Module *M = MMI->getModule();
811 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
812 for (MDNode *N : CU_Nodes->operands()) {
813 DICompileUnit TheCU(N);
814 // Construct subprogram DIE and add variables DIEs.
815 DwarfCompileUnit *SPCU =
816 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
817 DIArray Subprograms = TheCU.getSubprograms();
818 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
819 DISubprogram SP(Subprograms.getElement(i));
820 // Perhaps the subprogram is in another CU (such as due to comdat
821 // folding, etc), in which case ignore it here.
822 if (SPMap[SP] != SPCU)
824 DIE *D = SPCU->getDIE(SP);
825 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
827 // If this subprogram has an abstract definition, reference that
828 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
831 // Lazily construct the subprogram if we didn't see either concrete or
832 // inlined versions during codegen.
833 D = SPCU->getOrCreateSubprogramDIE(SP);
834 // And attach the attributes
835 SPCU->applySubprogramAttributesToDefinition(SP, *D);
842 // Collect info for variables that were optimized out.
843 void DwarfDebug::collectDeadVariables() {
844 const Module *M = MMI->getModule();
846 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
847 for (MDNode *N : CU_Nodes->operands()) {
848 DICompileUnit TheCU(N);
849 // Construct subprogram DIE and add variables DIEs.
850 DwarfCompileUnit *SPCU =
851 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
852 assert(SPCU && "Unable to find Compile Unit!");
853 DIArray Subprograms = TheCU.getSubprograms();
854 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
855 DISubprogram SP(Subprograms.getElement(i));
856 if (ProcessedSPNodes.count(SP) != 0)
858 assert(SP.isSubprogram() &&
859 "CU's subprogram list contains a non-subprogram");
860 assert(SP.isDefinition() &&
861 "CU's subprogram list contains a subprogram declaration");
862 DIArray Variables = SP.getVariables();
863 if (Variables.getNumElements() == 0)
866 DIE *SPDIE = AbstractSPDies.lookup(SP);
868 SPDIE = SPCU->getDIE(SP);
870 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
871 DIVariable DV(Variables.getElement(vi));
872 assert(DV.isVariable());
873 DbgVariable NewVar(DV, this);
874 auto VariableDie = SPCU->constructVariableDIE(NewVar);
875 SPCU->applyVariableAttributes(NewVar, *VariableDie);
876 SPDIE->addChild(std::move(VariableDie));
883 void DwarfDebug::finalizeModuleInfo() {
884 finishSubprogramDefinitions();
886 finishVariableDefinitions();
888 // Collect info for variables that were optimized out.
889 collectDeadVariables();
891 // Handle anything that needs to be done on a per-unit basis after
892 // all other generation.
893 for (const auto &TheU : getUnits()) {
894 // Emit DW_AT_containing_type attribute to connect types with their
895 // vtable holding type.
896 TheU->constructContainingTypeDIEs();
898 // Add CU specific attributes if we need to add any.
899 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
900 // If we're splitting the dwarf out now that we've got the entire
901 // CU then add the dwo id to it.
902 DwarfCompileUnit *SkCU =
903 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
904 if (useSplitDwarf()) {
905 // Emit a unique identifier for this CU.
906 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
907 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
908 dwarf::DW_FORM_data8, ID);
909 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
910 dwarf::DW_FORM_data8, ID);
912 // We don't keep track of which addresses are used in which CU so this
913 // is a bit pessimistic under LTO.
914 if (!AddrPool.isEmpty())
915 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
916 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
917 DwarfAddrSectionSym);
918 if (!TheU->getRangeLists().empty())
919 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
920 dwarf::DW_AT_GNU_ranges_base,
921 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
924 // If we have code split among multiple sections or non-contiguous
925 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
926 // remain in the .o file, otherwise add a DW_AT_low_pc.
927 // FIXME: We should use ranges allow reordering of code ala
928 // .subsections_via_symbols in mach-o. This would mean turning on
929 // ranges for all subprogram DIEs for mach-o.
930 DwarfCompileUnit &U =
931 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
932 unsigned NumRanges = TheU->getRanges().size();
935 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
936 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
937 DwarfDebugRangeSectionSym);
939 // A DW_AT_low_pc attribute may also be specified in combination with
940 // DW_AT_ranges to specify the default base address for use in
941 // location lists (see Section 2.6.2) and range lists (see Section
943 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
946 RangeSpan &Range = TheU->getRanges().back();
947 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
949 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
956 // Compute DIE offsets and sizes.
957 InfoHolder.computeSizeAndOffsets();
959 SkeletonHolder.computeSizeAndOffsets();
962 void DwarfDebug::endSections() {
963 // Filter labels by section.
964 for (const SymbolCU &SCU : ArangeLabels) {
965 if (SCU.Sym->isInSection()) {
966 // Make a note of this symbol and it's section.
967 const MCSection *Section = &SCU.Sym->getSection();
968 if (!Section->getKind().isMetadata())
969 SectionMap[Section].push_back(SCU);
971 // Some symbols (e.g. common/bss on mach-o) can have no section but still
972 // appear in the output. This sucks as we rely on sections to build
973 // arange spans. We can do it without, but it's icky.
974 SectionMap[nullptr].push_back(SCU);
978 // Build a list of sections used.
979 std::vector<const MCSection *> Sections;
980 for (const auto &it : SectionMap) {
981 const MCSection *Section = it.first;
982 Sections.push_back(Section);
985 // Sort the sections into order.
986 // This is only done to ensure consistent output order across different runs.
987 std::sort(Sections.begin(), Sections.end(), SectionSort);
989 // Add terminating symbols for each section.
990 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
991 const MCSection *Section = Sections[ID];
992 MCSymbol *Sym = nullptr;
995 // We can't call MCSection::getLabelEndName, as it's only safe to do so
996 // if we know the section name up-front. For user-created sections, the
997 // resulting label may not be valid to use as a label. (section names can
998 // use a greater set of characters on some systems)
999 Sym = Asm->GetTempSymbol("debug_end", ID);
1000 Asm->OutStreamer.SwitchSection(Section);
1001 Asm->OutStreamer.EmitLabel(Sym);
1004 // Insert a final terminator.
1005 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1009 // Emit all Dwarf sections that should come after the content.
1010 void DwarfDebug::endModule() {
1011 assert(CurFn == nullptr);
1012 assert(CurMI == nullptr);
1017 // End any existing sections.
1018 // TODO: Does this need to happen?
1021 // Finalize the debug info for the module.
1022 finalizeModuleInfo();
1026 // Emit all the DIEs into a debug info section.
1029 // Corresponding abbreviations into a abbrev section.
1030 emitAbbreviations();
1032 // Emit info into a debug aranges section.
1033 if (GenerateARangeSection)
1036 // Emit info into a debug ranges section.
1039 if (useSplitDwarf()) {
1042 emitDebugAbbrevDWO();
1045 // Emit DWO addresses.
1046 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1048 // Emit info into a debug loc section.
1051 // Emit info into the dwarf accelerator table sections.
1052 if (useDwarfAccelTables()) {
1055 emitAccelNamespaces();
1059 // Emit the pubnames and pubtypes sections if requested.
1060 if (HasDwarfPubSections) {
1061 emitDebugPubNames(GenerateGnuPubSections);
1062 emitDebugPubTypes(GenerateGnuPubSections);
1067 AbstractVariables.clear();
1069 // Reset these for the next Module if we have one.
1073 // Find abstract variable, if any, associated with Var.
1074 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1075 DIVariable &Cleansed) {
1076 LLVMContext &Ctx = DV->getContext();
1077 // More then one inlined variable corresponds to one abstract variable.
1078 // FIXME: This duplication of variables when inlining should probably be
1079 // removed. It's done to allow each DIVariable to describe its location
1080 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1081 // make it accurate then remove this duplication/cleansing stuff.
1082 Cleansed = cleanseInlinedVariable(DV, Ctx);
1083 auto I = AbstractVariables.find(Cleansed);
1084 if (I != AbstractVariables.end())
1085 return I->second.get();
1089 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1090 DIVariable Cleansed;
1091 return getExistingAbstractVariable(DV, Cleansed);
1094 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1095 LexicalScope *Scope) {
1096 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1097 addScopeVariable(Scope, AbsDbgVariable.get());
1098 AbstractVariables[Var] = std::move(AbsDbgVariable);
1101 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1102 const MDNode *ScopeNode) {
1103 DIVariable Cleansed = DV;
1104 if (getExistingAbstractVariable(DV, Cleansed))
1107 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1111 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1112 const MDNode *ScopeNode) {
1113 DIVariable Cleansed = DV;
1114 if (getExistingAbstractVariable(DV, Cleansed))
1117 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1118 createAbstractVariable(Cleansed, Scope);
1121 // If Var is a current function argument then add it to CurrentFnArguments list.
1122 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1123 if (!LScopes.isCurrentFunctionScope(Scope))
1125 DIVariable DV = Var->getVariable();
1126 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1128 unsigned ArgNo = DV.getArgNumber();
1132 size_t Size = CurrentFnArguments.size();
1134 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1135 // llvm::Function argument size is not good indicator of how many
1136 // arguments does the function have at source level.
1138 CurrentFnArguments.resize(ArgNo * 2);
1139 CurrentFnArguments[ArgNo - 1] = Var;
1143 // Collect variable information from side table maintained by MMI.
1144 void DwarfDebug::collectVariableInfoFromMMITable(
1145 SmallPtrSet<const MDNode *, 16> &Processed) {
1146 for (const auto &VI : MMI->getVariableDbgInfo()) {
1149 Processed.insert(VI.Var);
1150 DIVariable DV(VI.Var);
1151 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1153 // If variable scope is not found then skip this variable.
1157 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1158 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1159 DbgVariable *RegVar = ConcreteVariables.back().get();
1160 RegVar->setFrameIndex(VI.Slot);
1161 addScopeVariable(Scope, RegVar);
1165 // Get .debug_loc entry for the instruction range starting at MI.
1166 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1167 const MDNode *Var = MI->getDebugVariable();
1169 assert(MI->getNumOperands() == 3);
1170 if (MI->getOperand(0).isReg()) {
1171 MachineLocation MLoc;
1172 // If the second operand is an immediate, this is a
1173 // register-indirect address.
1174 if (!MI->getOperand(1).isImm())
1175 MLoc.set(MI->getOperand(0).getReg());
1177 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1178 return DebugLocEntry::Value(Var, MLoc);
1180 if (MI->getOperand(0).isImm())
1181 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1182 if (MI->getOperand(0).isFPImm())
1183 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1184 if (MI->getOperand(0).isCImm())
1185 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1187 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1190 // Find variables for each lexical scope.
1192 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1193 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1194 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1196 // Grab the variable info that was squirreled away in the MMI side-table.
1197 collectVariableInfoFromMMITable(Processed);
1199 for (const auto &I : DbgValues) {
1200 DIVariable DV(I.first);
1201 if (Processed.count(DV))
1204 // Instruction ranges, specifying where DV is accessible.
1205 const auto &Ranges = I.second;
1209 LexicalScope *Scope = nullptr;
1210 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1211 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1212 Scope = LScopes.getCurrentFunctionScope();
1213 else if (MDNode *IA = DV.getInlinedAt()) {
1214 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1215 Scope = LScopes.findInlinedScope(DebugLoc::get(
1216 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1218 Scope = LScopes.findLexicalScope(DV.getContext());
1219 // If variable scope is not found then skip this variable.
1223 Processed.insert(DV);
1224 const MachineInstr *MInsn = Ranges.front().first;
1225 assert(MInsn->isDebugValue() && "History must begin with debug value");
1226 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1227 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1228 DbgVariable *RegVar = ConcreteVariables.back().get();
1229 addScopeVariable(Scope, RegVar);
1231 // Check if the first DBG_VALUE is valid for the rest of the function.
1232 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1235 // Handle multiple DBG_VALUE instructions describing one variable.
1236 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1238 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1239 DebugLocList &LocList = DotDebugLocEntries.back();
1241 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1242 SmallVector<DebugLocEntry, 4> &DebugLoc = LocList.List;
1243 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1244 const MachineInstr *Begin = I->first;
1245 const MachineInstr *End = I->second;
1246 assert(Begin->isDebugValue() && "Invalid History entry");
1248 // Check if a variable is unaccessible in this range.
1249 if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1250 !Begin->getOperand(0).getReg())
1252 DEBUG(dbgs() << "DotDebugLoc Pair:\n" << "\t" << *Begin);
1254 DEBUG(dbgs() << "\t" << *End);
1256 DEBUG(dbgs() << "\tNULL\n");
1258 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1259 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1261 const MCSymbol *EndLabel;
1263 EndLabel = getLabelAfterInsn(End);
1264 else if (std::next(I) == Ranges.end())
1265 EndLabel = FunctionEndSym;
1267 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1268 assert(EndLabel && "Forgot label after instruction ending a range!");
1270 DebugLocEntry Loc(StartLabel, EndLabel, getDebugLocValue(Begin), TheCU);
1271 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc))
1272 DebugLoc.push_back(std::move(Loc));
1276 // Collect info for variables that were optimized out.
1277 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1278 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1279 DIVariable DV(Variables.getElement(i));
1280 assert(DV.isVariable());
1281 if (!Processed.insert(DV))
1283 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1284 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1285 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1286 addScopeVariable(Scope, ConcreteVariables.back().get());
1291 // Return Label preceding the instruction.
1292 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1293 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1294 assert(Label && "Didn't insert label before instruction");
1298 // Return Label immediately following the instruction.
1299 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1300 return LabelsAfterInsn.lookup(MI);
1303 // Process beginning of an instruction.
1304 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1305 assert(CurMI == nullptr);
1307 // Check if source location changes, but ignore DBG_VALUE locations.
1308 if (!MI->isDebugValue()) {
1309 DebugLoc DL = MI->getDebugLoc();
1310 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1313 if (DL == PrologEndLoc) {
1314 Flags |= DWARF2_FLAG_PROLOGUE_END;
1315 PrologEndLoc = DebugLoc();
1317 if (PrologEndLoc.isUnknown())
1318 Flags |= DWARF2_FLAG_IS_STMT;
1320 if (!DL.isUnknown()) {
1321 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1322 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1324 recordSourceLine(0, 0, nullptr, 0);
1328 // Insert labels where requested.
1329 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1330 LabelsBeforeInsn.find(MI);
1333 if (I == LabelsBeforeInsn.end())
1336 // Label already assigned.
1341 PrevLabel = MMI->getContext().CreateTempSymbol();
1342 Asm->OutStreamer.EmitLabel(PrevLabel);
1344 I->second = PrevLabel;
1347 // Process end of an instruction.
1348 void DwarfDebug::endInstruction() {
1349 assert(CurMI != nullptr);
1350 // Don't create a new label after DBG_VALUE instructions.
1351 // They don't generate code.
1352 if (!CurMI->isDebugValue())
1353 PrevLabel = nullptr;
1355 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1356 LabelsAfterInsn.find(CurMI);
1360 if (I == LabelsAfterInsn.end())
1363 // Label already assigned.
1367 // We need a label after this instruction.
1369 PrevLabel = MMI->getContext().CreateTempSymbol();
1370 Asm->OutStreamer.EmitLabel(PrevLabel);
1372 I->second = PrevLabel;
1375 // Each LexicalScope has first instruction and last instruction to mark
1376 // beginning and end of a scope respectively. Create an inverse map that list
1377 // scopes starts (and ends) with an instruction. One instruction may start (or
1378 // end) multiple scopes. Ignore scopes that are not reachable.
1379 void DwarfDebug::identifyScopeMarkers() {
1380 SmallVector<LexicalScope *, 4> WorkList;
1381 WorkList.push_back(LScopes.getCurrentFunctionScope());
1382 while (!WorkList.empty()) {
1383 LexicalScope *S = WorkList.pop_back_val();
1385 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1386 if (!Children.empty())
1387 WorkList.append(Children.begin(), Children.end());
1389 if (S->isAbstractScope())
1392 for (const InsnRange &R : S->getRanges()) {
1393 assert(R.first && "InsnRange does not have first instruction!");
1394 assert(R.second && "InsnRange does not have second instruction!");
1395 requestLabelBeforeInsn(R.first);
1396 requestLabelAfterInsn(R.second);
1401 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1402 // First known non-DBG_VALUE and non-frame setup location marks
1403 // the beginning of the function body.
1404 for (const auto &MBB : *MF)
1405 for (const auto &MI : MBB)
1406 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1407 !MI.getDebugLoc().isUnknown())
1408 return MI.getDebugLoc();
1412 // Gather pre-function debug information. Assumes being called immediately
1413 // after the function entry point has been emitted.
1414 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1417 // If there's no debug info for the function we're not going to do anything.
1418 if (!MMI->hasDebugInfo())
1421 auto DI = FunctionDIs.find(MF->getFunction());
1422 if (DI == FunctionDIs.end())
1425 // Grab the lexical scopes for the function, if we don't have any of those
1426 // then we're not going to be able to do anything.
1427 LScopes.initialize(*MF);
1428 if (LScopes.empty())
1431 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1433 // Make sure that each lexical scope will have a begin/end label.
1434 identifyScopeMarkers();
1436 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1437 // belongs to so that we add to the correct per-cu line table in the
1439 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1440 // FnScope->getScopeNode() and DI->second should represent the same function,
1441 // though they may not be the same MDNode due to inline functions merged in
1442 // LTO where the debug info metadata still differs (either due to distinct
1443 // written differences - two versions of a linkonce_odr function
1444 // written/copied into two separate files, or some sub-optimal metadata that
1445 // isn't structurally identical (see: file path/name info from clang, which
1446 // includes the directory of the cpp file being built, even when the file name
1447 // is absolute (such as an <> lookup header)))
1448 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1449 assert(TheCU && "Unable to find compile unit!");
1450 if (Asm->OutStreamer.hasRawTextSupport())
1451 // Use a single line table if we are generating assembly.
1452 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1454 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1456 // Emit a label for the function so that we have a beginning address.
1457 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1458 // Assumes in correct section after the entry point.
1459 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1461 // Calculate history for local variables.
1462 calculateDbgValueHistory(MF, Asm->TM.getRegisterInfo(), DbgValues);
1464 // Request labels for the full history.
1465 for (const auto &I : DbgValues) {
1466 const auto &Ranges = I.second;
1470 // The first mention of a function argument gets the FunctionBeginSym
1471 // label, so arguments are visible when breaking at function entry.
1472 DIVariable DV(I.first);
1473 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1474 getDISubprogram(DV.getContext()).describes(MF->getFunction()))
1475 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1477 for (const auto &Range : Ranges) {
1478 requestLabelBeforeInsn(Range.first);
1480 requestLabelAfterInsn(Range.second);
1484 PrevInstLoc = DebugLoc();
1485 PrevLabel = FunctionBeginSym;
1487 // Record beginning of function.
1488 PrologEndLoc = findPrologueEndLoc(MF);
1489 if (!PrologEndLoc.isUnknown()) {
1490 DebugLoc FnStartDL =
1491 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1493 FnStartDL.getLine(), FnStartDL.getCol(),
1494 FnStartDL.getScope(MF->getFunction()->getContext()),
1495 // We'd like to list the prologue as "not statements" but GDB behaves
1496 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1497 DWARF2_FLAG_IS_STMT);
1501 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1502 if (addCurrentFnArgument(Var, LS))
1504 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1505 DIVariable DV = Var->getVariable();
1506 // Variables with positive arg numbers are parameters.
1507 if (unsigned ArgNum = DV.getArgNumber()) {
1508 // Keep all parameters in order at the start of the variable list to ensure
1509 // function types are correct (no out-of-order parameters)
1511 // This could be improved by only doing it for optimized builds (unoptimized
1512 // builds have the right order to begin with), searching from the back (this
1513 // would catch the unoptimized case quickly), or doing a binary search
1514 // rather than linear search.
1515 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1516 while (I != Vars.end()) {
1517 unsigned CurNum = (*I)->getVariable().getArgNumber();
1518 // A local (non-parameter) variable has been found, insert immediately
1522 // A later indexed parameter has been found, insert immediately before it.
1523 if (CurNum > ArgNum)
1527 Vars.insert(I, Var);
1531 Vars.push_back(Var);
1534 // Gather and emit post-function debug information.
1535 void DwarfDebug::endFunction(const MachineFunction *MF) {
1536 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1537 // though the beginFunction may not be called at all.
1538 // We should handle both cases.
1542 assert(CurFn == MF);
1543 assert(CurFn != nullptr);
1545 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1546 !FunctionDIs.count(MF->getFunction())) {
1547 // If we don't have a lexical scope for this function then there will
1548 // be a hole in the range information. Keep note of this by setting the
1549 // previously used section to nullptr.
1550 PrevSection = nullptr;
1556 // Define end label for subprogram.
1557 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1558 // Assumes in correct section after the entry point.
1559 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1561 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1562 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1564 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1565 collectVariableInfo(ProcessedVars);
1567 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1568 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1570 // Construct abstract scopes.
1571 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1572 DISubprogram SP(AScope->getScopeNode());
1573 if (!SP.isSubprogram())
1575 // Collect info for variables that were optimized out.
1576 DIArray Variables = SP.getVariables();
1577 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1578 DIVariable DV(Variables.getElement(i));
1579 assert(DV && DV.isVariable());
1580 if (!ProcessedVars.insert(DV))
1582 ensureAbstractVariableIsCreated(DV, DV.getContext());
1584 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1587 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1588 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1589 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1591 // Add the range of this function to the list of ranges for the CU.
1592 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1593 TheCU.addRange(std::move(Span));
1594 PrevSection = Asm->getCurrentSection();
1598 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1599 // DbgVariables except those that are also in AbstractVariables (since they
1600 // can be used cross-function)
1601 ScopeVariables.clear();
1602 CurrentFnArguments.clear();
1604 LabelsBeforeInsn.clear();
1605 LabelsAfterInsn.clear();
1606 PrevLabel = nullptr;
1610 // Register a source line with debug info. Returns the unique label that was
1611 // emitted and which provides correspondence to the source line list.
1612 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1617 unsigned Discriminator = 0;
1618 if (DIScope Scope = DIScope(S)) {
1619 assert(Scope.isScope());
1620 Fn = Scope.getFilename();
1621 Dir = Scope.getDirectory();
1622 if (Scope.isLexicalBlock())
1623 Discriminator = DILexicalBlock(S).getDiscriminator();
1625 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1626 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1627 .getOrCreateSourceID(Fn, Dir);
1629 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1633 //===----------------------------------------------------------------------===//
1635 //===----------------------------------------------------------------------===//
1637 // Emit initial Dwarf sections with a label at the start of each one.
1638 void DwarfDebug::emitSectionLabels() {
1639 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1641 // Dwarf sections base addresses.
1642 DwarfInfoSectionSym =
1643 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1644 if (useSplitDwarf())
1645 DwarfInfoDWOSectionSym =
1646 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1647 DwarfAbbrevSectionSym =
1648 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1649 if (useSplitDwarf())
1650 DwarfAbbrevDWOSectionSym = emitSectionSym(
1651 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1652 if (GenerateARangeSection)
1653 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1655 DwarfLineSectionSym =
1656 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1657 if (GenerateGnuPubSections) {
1658 DwarfGnuPubNamesSectionSym =
1659 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1660 DwarfGnuPubTypesSectionSym =
1661 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1662 } else if (HasDwarfPubSections) {
1663 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1664 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1667 DwarfStrSectionSym =
1668 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1669 if (useSplitDwarf()) {
1670 DwarfStrDWOSectionSym =
1671 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1672 DwarfAddrSectionSym =
1673 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1674 DwarfDebugLocSectionSym =
1675 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1677 DwarfDebugLocSectionSym =
1678 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1679 DwarfDebugRangeSectionSym =
1680 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1683 // Recursively emits a debug information entry.
1684 void DwarfDebug::emitDIE(DIE &Die) {
1685 // Get the abbreviation for this DIE.
1686 const DIEAbbrev &Abbrev = Die.getAbbrev();
1688 // Emit the code (index) for the abbreviation.
1689 if (Asm->isVerbose())
1690 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1691 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1692 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1693 dwarf::TagString(Abbrev.getTag()));
1694 Asm->EmitULEB128(Abbrev.getNumber());
1696 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1697 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1699 // Emit the DIE attribute values.
1700 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1701 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1702 dwarf::Form Form = AbbrevData[i].getForm();
1703 assert(Form && "Too many attributes for DIE (check abbreviation)");
1705 if (Asm->isVerbose()) {
1706 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1707 if (Attr == dwarf::DW_AT_accessibility)
1708 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1709 cast<DIEInteger>(Values[i])->getValue()));
1712 // Emit an attribute using the defined form.
1713 Values[i]->EmitValue(Asm, Form);
1716 // Emit the DIE children if any.
1717 if (Abbrev.hasChildren()) {
1718 for (auto &Child : Die.getChildren())
1721 Asm->OutStreamer.AddComment("End Of Children Mark");
1726 // Emit the debug info section.
1727 void DwarfDebug::emitDebugInfo() {
1728 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1730 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1733 // Emit the abbreviation section.
1734 void DwarfDebug::emitAbbreviations() {
1735 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1737 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1740 // Emit the last address of the section and the end of the line matrix.
1741 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1742 // Define last address of section.
1743 Asm->OutStreamer.AddComment("Extended Op");
1746 Asm->OutStreamer.AddComment("Op size");
1747 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1748 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1749 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1751 Asm->OutStreamer.AddComment("Section end label");
1753 Asm->OutStreamer.EmitSymbolValue(
1754 Asm->GetTempSymbol("section_end", SectionEnd),
1755 Asm->getDataLayout().getPointerSize());
1757 // Mark end of matrix.
1758 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1764 // Emit visible names into a hashed accelerator table section.
1765 void DwarfDebug::emitAccelNames() {
1766 AccelNames.FinalizeTable(Asm, "Names");
1767 Asm->OutStreamer.SwitchSection(
1768 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1769 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1770 Asm->OutStreamer.EmitLabel(SectionBegin);
1772 // Emit the full data.
1773 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1776 // Emit objective C classes and categories into a hashed accelerator table
1778 void DwarfDebug::emitAccelObjC() {
1779 AccelObjC.FinalizeTable(Asm, "ObjC");
1780 Asm->OutStreamer.SwitchSection(
1781 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1782 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1783 Asm->OutStreamer.EmitLabel(SectionBegin);
1785 // Emit the full data.
1786 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1789 // Emit namespace dies into a hashed accelerator table.
1790 void DwarfDebug::emitAccelNamespaces() {
1791 AccelNamespace.FinalizeTable(Asm, "namespac");
1792 Asm->OutStreamer.SwitchSection(
1793 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1794 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1795 Asm->OutStreamer.EmitLabel(SectionBegin);
1797 // Emit the full data.
1798 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1801 // Emit type dies into a hashed accelerator table.
1802 void DwarfDebug::emitAccelTypes() {
1804 AccelTypes.FinalizeTable(Asm, "types");
1805 Asm->OutStreamer.SwitchSection(
1806 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1807 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1808 Asm->OutStreamer.EmitLabel(SectionBegin);
1810 // Emit the full data.
1811 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1814 // Public name handling.
1815 // The format for the various pubnames:
1817 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1818 // for the DIE that is named.
1820 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1821 // into the CU and the index value is computed according to the type of value
1822 // for the DIE that is named.
1824 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1825 // it's the offset within the debug_info/debug_types dwo section, however, the
1826 // reference in the pubname header doesn't change.
1828 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1829 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1831 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1833 // We could have a specification DIE that has our most of our knowledge,
1834 // look for that now.
1835 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1837 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1838 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1839 Linkage = dwarf::GIEL_EXTERNAL;
1840 } else if (Die->findAttribute(dwarf::DW_AT_external))
1841 Linkage = dwarf::GIEL_EXTERNAL;
1843 switch (Die->getTag()) {
1844 case dwarf::DW_TAG_class_type:
1845 case dwarf::DW_TAG_structure_type:
1846 case dwarf::DW_TAG_union_type:
1847 case dwarf::DW_TAG_enumeration_type:
1848 return dwarf::PubIndexEntryDescriptor(
1849 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1850 ? dwarf::GIEL_STATIC
1851 : dwarf::GIEL_EXTERNAL);
1852 case dwarf::DW_TAG_typedef:
1853 case dwarf::DW_TAG_base_type:
1854 case dwarf::DW_TAG_subrange_type:
1855 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1856 case dwarf::DW_TAG_namespace:
1857 return dwarf::GIEK_TYPE;
1858 case dwarf::DW_TAG_subprogram:
1859 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1860 case dwarf::DW_TAG_constant:
1861 case dwarf::DW_TAG_variable:
1862 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1863 case dwarf::DW_TAG_enumerator:
1864 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1865 dwarf::GIEL_STATIC);
1867 return dwarf::GIEK_NONE;
1871 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1873 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1874 const MCSection *PSec =
1875 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1876 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1878 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1881 void DwarfDebug::emitDebugPubSection(
1882 bool GnuStyle, const MCSection *PSec, StringRef Name,
1883 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1884 for (const auto &NU : CUMap) {
1885 DwarfCompileUnit *TheU = NU.second;
1887 const auto &Globals = (TheU->*Accessor)();
1889 if (Globals.empty())
1892 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1894 unsigned ID = TheU->getUniqueID();
1896 // Start the dwarf pubnames section.
1897 Asm->OutStreamer.SwitchSection(PSec);
1900 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1901 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
1902 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
1903 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1905 Asm->OutStreamer.EmitLabel(BeginLabel);
1907 Asm->OutStreamer.AddComment("DWARF Version");
1908 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1910 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1911 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
1913 Asm->OutStreamer.AddComment("Compilation Unit Length");
1914 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
1916 // Emit the pubnames for this compilation unit.
1917 for (const auto &GI : Globals) {
1918 const char *Name = GI.getKeyData();
1919 const DIE *Entity = GI.second;
1921 Asm->OutStreamer.AddComment("DIE offset");
1922 Asm->EmitInt32(Entity->getOffset());
1925 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1926 Asm->OutStreamer.AddComment(
1927 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1928 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1929 Asm->EmitInt8(Desc.toBits());
1932 Asm->OutStreamer.AddComment("External Name");
1933 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1936 Asm->OutStreamer.AddComment("End Mark");
1938 Asm->OutStreamer.EmitLabel(EndLabel);
1942 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1943 const MCSection *PSec =
1944 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1945 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1947 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
1950 // Emit visible names into a debug str section.
1951 void DwarfDebug::emitDebugStr() {
1952 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1953 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1956 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1957 const DebugLocEntry &Entry) {
1958 assert(Entry.getValues().size() == 1 &&
1959 "multi-value entries are not supported yet.");
1960 const DebugLocEntry::Value Value = Entry.getValues()[0];
1961 DIVariable DV(Value.getVariable());
1962 if (Value.isInt()) {
1963 DIBasicType BTy(resolve(DV.getType()));
1964 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
1965 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
1966 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
1967 Streamer.EmitSLEB128(Value.getInt());
1969 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
1970 Streamer.EmitULEB128(Value.getInt());
1972 } else if (Value.isLocation()) {
1973 MachineLocation Loc = Value.getLoc();
1974 if (!DV.hasComplexAddress())
1976 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
1978 // Complex address entry.
1979 unsigned N = DV.getNumAddrElements();
1981 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
1982 if (Loc.getOffset()) {
1984 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
1985 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
1986 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
1987 Streamer.EmitSLEB128(DV.getAddrElement(1));
1989 // If first address element is OpPlus then emit
1990 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
1991 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
1992 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
1996 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
1999 // Emit remaining complex address elements.
2000 for (; i < N; ++i) {
2001 uint64_t Element = DV.getAddrElement(i);
2002 if (Element == DIBuilder::OpPlus) {
2003 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2004 Streamer.EmitULEB128(DV.getAddrElement(++i));
2005 } else if (Element == DIBuilder::OpDeref) {
2007 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2009 llvm_unreachable("unknown Opcode found in complex address");
2013 // else ... ignore constant fp. There is not any good way to
2014 // to represent them here in dwarf.
2018 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2019 Asm->OutStreamer.AddComment("Loc expr size");
2020 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2021 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2022 Asm->EmitLabelDifference(end, begin, 2);
2023 Asm->OutStreamer.EmitLabel(begin);
2025 APByteStreamer Streamer(*Asm);
2026 emitDebugLocEntry(Streamer, Entry);
2028 Asm->OutStreamer.EmitLabel(end);
2031 // Emit locations into the debug loc section.
2032 void DwarfDebug::emitDebugLoc() {
2033 // Start the dwarf loc section.
2034 Asm->OutStreamer.SwitchSection(
2035 Asm->getObjFileLowering().getDwarfLocSection());
2036 unsigned char Size = Asm->getDataLayout().getPointerSize();
2037 for (const auto &DebugLoc : DotDebugLocEntries) {
2038 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2039 for (const auto &Entry : DebugLoc.List) {
2040 // Set up the range. This range is relative to the entry point of the
2041 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2042 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2043 const DwarfCompileUnit *CU = Entry.getCU();
2044 if (CU->getRanges().size() == 1) {
2045 // Grab the begin symbol from the first range as our base.
2046 const MCSymbol *Base = CU->getRanges()[0].getStart();
2047 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2048 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2050 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2051 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2054 emitDebugLocEntryLocation(Entry);
2056 Asm->OutStreamer.EmitIntValue(0, Size);
2057 Asm->OutStreamer.EmitIntValue(0, Size);
2061 void DwarfDebug::emitDebugLocDWO() {
2062 Asm->OutStreamer.SwitchSection(
2063 Asm->getObjFileLowering().getDwarfLocDWOSection());
2064 for (const auto &DebugLoc : DotDebugLocEntries) {
2065 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2066 for (const auto &Entry : DebugLoc.List) {
2067 // Just always use start_length for now - at least that's one address
2068 // rather than two. We could get fancier and try to, say, reuse an
2069 // address we know we've emitted elsewhere (the start of the function?
2070 // The start of the CU or CU subrange that encloses this range?)
2071 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2072 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2073 Asm->EmitULEB128(idx);
2074 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2076 emitDebugLocEntryLocation(Entry);
2078 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2083 const MCSymbol *Start, *End;
2086 // Emit a debug aranges section, containing a CU lookup for any
2087 // address we can tie back to a CU.
2088 void DwarfDebug::emitDebugARanges() {
2089 // Start the dwarf aranges section.
2090 Asm->OutStreamer.SwitchSection(
2091 Asm->getObjFileLowering().getDwarfARangesSection());
2093 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2097 // Build a list of sections used.
2098 std::vector<const MCSection *> Sections;
2099 for (const auto &it : SectionMap) {
2100 const MCSection *Section = it.first;
2101 Sections.push_back(Section);
2104 // Sort the sections into order.
2105 // This is only done to ensure consistent output order across different runs.
2106 std::sort(Sections.begin(), Sections.end(), SectionSort);
2108 // Build a set of address spans, sorted by CU.
2109 for (const MCSection *Section : Sections) {
2110 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2111 if (List.size() < 2)
2114 // Sort the symbols by offset within the section.
2115 std::sort(List.begin(), List.end(),
2116 [&](const SymbolCU &A, const SymbolCU &B) {
2117 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2118 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2120 // Symbols with no order assigned should be placed at the end.
2121 // (e.g. section end labels)
2129 // If we have no section (e.g. common), just write out
2130 // individual spans for each symbol.
2132 for (const SymbolCU &Cur : List) {
2134 Span.Start = Cur.Sym;
2137 Spans[Cur.CU].push_back(Span);
2140 // Build spans between each label.
2141 const MCSymbol *StartSym = List[0].Sym;
2142 for (size_t n = 1, e = List.size(); n < e; n++) {
2143 const SymbolCU &Prev = List[n - 1];
2144 const SymbolCU &Cur = List[n];
2146 // Try and build the longest span we can within the same CU.
2147 if (Cur.CU != Prev.CU) {
2149 Span.Start = StartSym;
2151 Spans[Prev.CU].push_back(Span);
2158 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2160 // Build a list of CUs used.
2161 std::vector<DwarfCompileUnit *> CUs;
2162 for (const auto &it : Spans) {
2163 DwarfCompileUnit *CU = it.first;
2167 // Sort the CU list (again, to ensure consistent output order).
2168 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2169 return A->getUniqueID() < B->getUniqueID();
2172 // Emit an arange table for each CU we used.
2173 for (DwarfCompileUnit *CU : CUs) {
2174 std::vector<ArangeSpan> &List = Spans[CU];
2176 // Emit size of content not including length itself.
2177 unsigned ContentSize =
2178 sizeof(int16_t) + // DWARF ARange version number
2179 sizeof(int32_t) + // Offset of CU in the .debug_info section
2180 sizeof(int8_t) + // Pointer Size (in bytes)
2181 sizeof(int8_t); // Segment Size (in bytes)
2183 unsigned TupleSize = PtrSize * 2;
2185 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2187 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2189 ContentSize += Padding;
2190 ContentSize += (List.size() + 1) * TupleSize;
2192 // For each compile unit, write the list of spans it covers.
2193 Asm->OutStreamer.AddComment("Length of ARange Set");
2194 Asm->EmitInt32(ContentSize);
2195 Asm->OutStreamer.AddComment("DWARF Arange version number");
2196 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2197 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2198 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2199 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2200 Asm->EmitInt8(PtrSize);
2201 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2204 Asm->OutStreamer.EmitFill(Padding, 0xff);
2206 for (const ArangeSpan &Span : List) {
2207 Asm->EmitLabelReference(Span.Start, PtrSize);
2209 // Calculate the size as being from the span start to it's end.
2211 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2213 // For symbols without an end marker (e.g. common), we
2214 // write a single arange entry containing just that one symbol.
2215 uint64_t Size = SymSize[Span.Start];
2219 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2223 Asm->OutStreamer.AddComment("ARange terminator");
2224 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2225 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2229 // Emit visible names into a debug ranges section.
2230 void DwarfDebug::emitDebugRanges() {
2231 // Start the dwarf ranges section.
2232 Asm->OutStreamer.SwitchSection(
2233 Asm->getObjFileLowering().getDwarfRangesSection());
2235 // Size for our labels.
2236 unsigned char Size = Asm->getDataLayout().getPointerSize();
2238 // Grab the specific ranges for the compile units in the module.
2239 for (const auto &I : CUMap) {
2240 DwarfCompileUnit *TheCU = I.second;
2242 // Iterate over the misc ranges for the compile units in the module.
2243 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2244 // Emit our symbol so we can find the beginning of the range.
2245 Asm->OutStreamer.EmitLabel(List.getSym());
2247 for (const RangeSpan &Range : List.getRanges()) {
2248 const MCSymbol *Begin = Range.getStart();
2249 const MCSymbol *End = Range.getEnd();
2250 assert(Begin && "Range without a begin symbol?");
2251 assert(End && "Range without an end symbol?");
2252 if (TheCU->getRanges().size() == 1) {
2253 // Grab the begin symbol from the first range as our base.
2254 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2255 Asm->EmitLabelDifference(Begin, Base, Size);
2256 Asm->EmitLabelDifference(End, Base, Size);
2258 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2259 Asm->OutStreamer.EmitSymbolValue(End, Size);
2263 // And terminate the list with two 0 values.
2264 Asm->OutStreamer.EmitIntValue(0, Size);
2265 Asm->OutStreamer.EmitIntValue(0, Size);
2268 // Now emit a range for the CU itself.
2269 if (TheCU->getRanges().size() > 1) {
2270 Asm->OutStreamer.EmitLabel(
2271 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2272 for (const RangeSpan &Range : TheCU->getRanges()) {
2273 const MCSymbol *Begin = Range.getStart();
2274 const MCSymbol *End = Range.getEnd();
2275 assert(Begin && "Range without a begin symbol?");
2276 assert(End && "Range without an end symbol?");
2277 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2278 Asm->OutStreamer.EmitSymbolValue(End, Size);
2280 // And terminate the list with two 0 values.
2281 Asm->OutStreamer.EmitIntValue(0, Size);
2282 Asm->OutStreamer.EmitIntValue(0, Size);
2287 // DWARF5 Experimental Separate Dwarf emitters.
2289 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2290 std::unique_ptr<DwarfUnit> NewU) {
2291 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2292 U.getCUNode().getSplitDebugFilename());
2294 if (!CompilationDir.empty())
2295 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2297 addGnuPubAttributes(*NewU, Die);
2299 SkeletonHolder.addUnit(std::move(NewU));
2302 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2303 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2304 // DW_AT_addr_base, DW_AT_ranges_base.
2305 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2307 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2308 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2309 DwarfCompileUnit &NewCU = *OwnedUnit;
2310 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2311 DwarfInfoSectionSym);
2313 NewCU.initStmtList(DwarfLineSectionSym);
2315 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2320 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2322 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2323 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2324 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2326 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2328 DwarfTypeUnit &NewTU = *OwnedUnit;
2329 NewTU.setTypeSignature(TU.getTypeSignature());
2330 NewTU.setType(nullptr);
2332 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2334 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2338 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2339 // compile units that would normally be in debug_info.
2340 void DwarfDebug::emitDebugInfoDWO() {
2341 assert(useSplitDwarf() && "No split dwarf debug info?");
2342 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2343 // emit relocations into the dwo file.
2344 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2347 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2348 // abbreviations for the .debug_info.dwo section.
2349 void DwarfDebug::emitDebugAbbrevDWO() {
2350 assert(useSplitDwarf() && "No split dwarf?");
2351 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2354 void DwarfDebug::emitDebugLineDWO() {
2355 assert(useSplitDwarf() && "No split dwarf?");
2356 Asm->OutStreamer.SwitchSection(
2357 Asm->getObjFileLowering().getDwarfLineDWOSection());
2358 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2361 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2362 // string section and is identical in format to traditional .debug_str
2364 void DwarfDebug::emitDebugStrDWO() {
2365 assert(useSplitDwarf() && "No split dwarf?");
2366 const MCSection *OffSec =
2367 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2368 const MCSymbol *StrSym = DwarfStrSectionSym;
2369 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2373 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2374 if (!useSplitDwarf())
2377 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2378 return &SplitTypeUnitFileTable;
2381 static uint64_t makeTypeSignature(StringRef Identifier) {
2383 Hash.update(Identifier);
2384 // ... take the least significant 8 bytes and return those. Our MD5
2385 // implementation always returns its results in little endian, swap bytes
2387 MD5::MD5Result Result;
2389 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2392 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2393 StringRef Identifier, DIE &RefDie,
2394 DICompositeType CTy) {
2395 // Fast path if we're building some type units and one has already used the
2396 // address pool we know we're going to throw away all this work anyway, so
2397 // don't bother building dependent types.
2398 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2401 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2403 CU.addDIETypeSignature(RefDie, *TU);
2407 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2408 AddrPool.resetUsedFlag();
2411 make_unique<DwarfTypeUnit>(InfoHolder.getUnits().size(), CU, Asm, this,
2412 &InfoHolder, getDwoLineTable(CU));
2413 DwarfTypeUnit &NewTU = *OwnedUnit;
2414 DIE &UnitDie = NewTU.getUnitDie();
2416 TypeUnitsUnderConstruction.push_back(
2417 std::make_pair(std::move(OwnedUnit), CTy));
2419 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2422 uint64_t Signature = makeTypeSignature(Identifier);
2423 NewTU.setTypeSignature(Signature);
2425 if (!useSplitDwarf())
2426 CU.applyStmtList(UnitDie);
2428 // FIXME: Skip using COMDAT groups for type units in the .dwo file once tools
2429 // such as DWP ( http://gcc.gnu.org/wiki/DebugFissionDWP ) can cope with it.
2432 ? Asm->getObjFileLowering().getDwarfTypesDWOSection(Signature)
2433 : Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2435 NewTU.setType(NewTU.createTypeDIE(CTy));
2438 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2439 TypeUnitsUnderConstruction.clear();
2441 // Types referencing entries in the address table cannot be placed in type
2443 if (AddrPool.hasBeenUsed()) {
2445 // Remove all the types built while building this type.
2446 // This is pessimistic as some of these types might not be dependent on
2447 // the type that used an address.
2448 for (const auto &TU : TypeUnitsToAdd)
2449 DwarfTypeUnits.erase(TU.second);
2451 // Construct this type in the CU directly.
2452 // This is inefficient because all the dependent types will be rebuilt
2453 // from scratch, including building them in type units, discovering that
2454 // they depend on addresses, throwing them out and rebuilding them.
2455 CU.constructTypeDIE(RefDie, CTy);
2459 // If the type wasn't dependent on fission addresses, finish adding the type
2460 // and all its dependent types.
2461 for (auto &TU : TypeUnitsToAdd) {
2462 if (useSplitDwarf())
2463 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2464 InfoHolder.addUnit(std::move(TU.first));
2467 CU.addDIETypeSignature(RefDie, NewTU);
2470 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2471 MCSymbol *Begin, MCSymbol *End) {
2472 assert(Begin && "Begin label should not be null!");
2473 assert(End && "End label should not be null!");
2474 assert(Begin->isDefined() && "Invalid starting label");
2475 assert(End->isDefined() && "Invalid end label");
2477 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2478 if (DwarfVersion < 4)
2479 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2481 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2484 // Accelerator table mutators - add each name along with its companion
2485 // DIE to the proper table while ensuring that the name that we're going
2486 // to reference is in the string table. We do this since the names we
2487 // add may not only be identical to the names in the DIE.
2488 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2489 if (!useDwarfAccelTables())
2491 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2495 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2496 if (!useDwarfAccelTables())
2498 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2502 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2503 if (!useDwarfAccelTables())
2505 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2509 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2510 if (!useDwarfAccelTables())
2512 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),