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"
51 #include "llvm/Target/TargetSubtargetInfo.h"
54 #define DEBUG_TYPE "dwarfdebug"
57 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
58 cl::desc("Disable debug info printing"));
60 static cl::opt<bool> UnknownLocations(
61 "use-unknown-locations", cl::Hidden,
62 cl::desc("Make an absence of debug location information explicit."),
66 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
67 cl::desc("Generate GNU-style pubnames and pubtypes"),
70 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
72 cl::desc("Generate dwarf aranges"),
76 enum DefaultOnOff { Default, Enable, Disable };
79 static cl::opt<DefaultOnOff>
80 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
81 cl::desc("Output prototype dwarf accelerator tables."),
82 cl::values(clEnumVal(Default, "Default for platform"),
83 clEnumVal(Enable, "Enabled"),
84 clEnumVal(Disable, "Disabled"), clEnumValEnd),
87 static cl::opt<DefaultOnOff>
88 SplitDwarf("split-dwarf", cl::Hidden,
89 cl::desc("Output DWARF5 split debug info."),
90 cl::values(clEnumVal(Default, "Default for platform"),
91 clEnumVal(Enable, "Enabled"),
92 clEnumVal(Disable, "Disabled"), clEnumValEnd),
95 static cl::opt<DefaultOnOff>
96 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
97 cl::desc("Generate DWARF pubnames and pubtypes sections"),
98 cl::values(clEnumVal(Default, "Default for platform"),
99 clEnumVal(Enable, "Enabled"),
100 clEnumVal(Disable, "Disabled"), clEnumValEnd),
103 static const char *const DWARFGroupName = "DWARF Emission";
104 static const char *const DbgTimerName = "DWARF Debug Writer";
106 //===----------------------------------------------------------------------===//
108 /// resolve - Look in the DwarfDebug map for the MDNode that
109 /// corresponds to the reference.
110 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
111 return DD->resolve(Ref);
114 bool DbgVariable::isBlockByrefVariable() const {
115 assert(Var.isVariable() && "Invalid complex DbgVariable!");
116 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
119 DIType DbgVariable::getType() const {
120 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
121 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
122 // addresses instead.
123 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
124 /* Byref variables, in Blocks, are declared by the programmer as
125 "SomeType VarName;", but the compiler creates a
126 __Block_byref_x_VarName struct, and gives the variable VarName
127 either the struct, or a pointer to the struct, as its type. This
128 is necessary for various behind-the-scenes things the compiler
129 needs to do with by-reference variables in blocks.
131 However, as far as the original *programmer* is concerned, the
132 variable should still have type 'SomeType', as originally declared.
134 The following function dives into the __Block_byref_x_VarName
135 struct to find the original type of the variable. This will be
136 passed back to the code generating the type for the Debug
137 Information Entry for the variable 'VarName'. 'VarName' will then
138 have the original type 'SomeType' in its debug information.
140 The original type 'SomeType' will be the type of the field named
141 'VarName' inside the __Block_byref_x_VarName struct.
143 NOTE: In order for this to not completely fail on the debugger
144 side, the Debug Information Entry for the variable VarName needs to
145 have a DW_AT_location that tells the debugger how to unwind through
146 the pointers and __Block_byref_x_VarName struct to find the actual
147 value of the variable. The function addBlockByrefType does this. */
149 uint16_t tag = Ty.getTag();
151 if (tag == dwarf::DW_TAG_pointer_type)
152 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
154 DIArray Elements = DICompositeType(subType).getElements();
155 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
156 DIDerivedType DT(Elements.getElement(i));
157 if (getName() == DT.getName())
158 return (resolve(DT.getTypeDerivedFrom()));
164 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
165 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
166 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
167 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
169 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
170 : Asm(A), MMI(Asm->MMI), FirstCU(nullptr), PrevLabel(nullptr),
171 GlobalRangeCount(0), InfoHolder(A, "info_string", DIEValueAllocator),
172 UsedNonDefaultText(false),
173 SkeletonHolder(A, "skel_string", DIEValueAllocator),
174 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
175 dwarf::DW_FORM_data4)),
176 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
177 dwarf::DW_FORM_data4)),
178 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
179 dwarf::DW_FORM_data4)),
180 AccelTypes(TypeAtoms) {
182 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = nullptr;
183 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = nullptr;
184 DwarfLineSectionSym = nullptr;
185 DwarfAddrSectionSym = nullptr;
186 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = nullptr;
187 FunctionBeginSym = FunctionEndSym = nullptr;
191 // Turn on accelerator tables for Darwin by default, pubnames by
192 // default for non-Darwin, and handle split dwarf.
193 bool IsDarwin = Triple(A->getTargetTriple()).isOSDarwin();
195 if (DwarfAccelTables == Default)
196 HasDwarfAccelTables = IsDarwin;
198 HasDwarfAccelTables = DwarfAccelTables == Enable;
200 if (SplitDwarf == Default)
201 HasSplitDwarf = false;
203 HasSplitDwarf = SplitDwarf == Enable;
205 if (DwarfPubSections == Default)
206 HasDwarfPubSections = !IsDarwin;
208 HasDwarfPubSections = DwarfPubSections == Enable;
210 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
211 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
212 : MMI->getModule()->getDwarfVersion();
214 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
217 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
222 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
223 DwarfDebug::~DwarfDebug() { }
225 // Switch to the specified MCSection and emit an assembler
226 // temporary label to it if SymbolStem is specified.
227 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
228 const char *SymbolStem = nullptr) {
229 Asm->OutStreamer.SwitchSection(Section);
233 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
234 Asm->OutStreamer.EmitLabel(TmpSym);
238 static bool isObjCClass(StringRef Name) {
239 return Name.startswith("+") || Name.startswith("-");
242 static bool hasObjCCategory(StringRef Name) {
243 if (!isObjCClass(Name))
246 return Name.find(") ") != StringRef::npos;
249 static void getObjCClassCategory(StringRef In, StringRef &Class,
250 StringRef &Category) {
251 if (!hasObjCCategory(In)) {
252 Class = In.slice(In.find('[') + 1, In.find(' '));
257 Class = In.slice(In.find('[') + 1, In.find('('));
258 Category = In.slice(In.find('[') + 1, In.find(' '));
262 static StringRef getObjCMethodName(StringRef In) {
263 return In.slice(In.find(' ') + 1, In.find(']'));
266 // Helper for sorting sections into a stable output order.
267 static bool SectionSort(const MCSection *A, const MCSection *B) {
268 std::string LA = (A ? A->getLabelBeginName() : "");
269 std::string LB = (B ? B->getLabelBeginName() : "");
273 // Add the various names to the Dwarf accelerator table names.
274 // TODO: Determine whether or not we should add names for programs
275 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
276 // is only slightly different than the lookup of non-standard ObjC names.
277 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
278 if (!SP.isDefinition())
280 addAccelName(SP.getName(), Die);
282 // If the linkage name is different than the name, go ahead and output
283 // that as well into the name table.
284 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
285 addAccelName(SP.getLinkageName(), Die);
287 // If this is an Objective-C selector name add it to the ObjC accelerator
289 if (isObjCClass(SP.getName())) {
290 StringRef Class, Category;
291 getObjCClassCategory(SP.getName(), Class, Category);
292 addAccelObjC(Class, Die);
294 addAccelObjC(Category, Die);
295 // Also add the base method name to the name table.
296 addAccelName(getObjCMethodName(SP.getName()), Die);
300 /// isSubprogramContext - Return true if Context is either a subprogram
301 /// or another context nested inside a subprogram.
302 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
305 DIDescriptor D(Context);
306 if (D.isSubprogram())
309 return isSubprogramContext(resolve(DIType(Context).getContext()));
313 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
314 // and DW_AT_high_pc attributes. If there are global variables in this
315 // scope then create and insert DIEs for these variables.
316 DIE &DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
318 DIE *SPDie = SPCU.getOrCreateSubprogramDIE(SP);
320 attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
322 const TargetRegisterInfo *RI = Asm->TM.getSubtargetImpl()->getRegisterInfo();
323 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
324 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
326 // Add name to the name table, we do this here because we're guaranteed
327 // to have concrete versions of our DW_TAG_subprogram nodes.
328 addSubprogramNames(SP, *SPDie);
333 /// Check whether we should create a DIE for the given Scope, return true
334 /// if we don't create a DIE (the corresponding DIE is null).
335 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
336 if (Scope->isAbstractScope())
339 // We don't create a DIE if there is no Range.
340 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
344 if (Ranges.size() > 1)
347 // We don't create a DIE if we have a single Range and the end label
349 return !getLabelAfterInsn(Ranges.front().second);
352 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
353 dwarf::Attribute A, const MCSymbol *L,
354 const MCSymbol *Sec) {
355 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
356 U.addSectionLabel(D, A, L);
358 U.addSectionDelta(D, A, L, Sec);
361 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
362 const SmallVectorImpl<InsnRange> &Range) {
363 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
364 // emitting it appropriately.
365 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
367 // Under fission, ranges are specified by constant offsets relative to the
368 // CU's DW_AT_GNU_ranges_base.
370 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
371 DwarfDebugRangeSectionSym);
373 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
374 DwarfDebugRangeSectionSym);
376 RangeSpanList List(RangeSym);
377 for (const InsnRange &R : Range) {
378 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
379 List.addRange(std::move(Span));
382 // Add the range list to the set of ranges to be emitted.
383 TheCU.addRangeList(std::move(List));
386 void DwarfDebug::attachRangesOrLowHighPC(DwarfCompileUnit &TheCU, DIE &Die,
387 const SmallVectorImpl<InsnRange> &Ranges) {
388 assert(!Ranges.empty());
389 if (Ranges.size() == 1)
390 attachLowHighPC(TheCU, Die, getLabelBeforeInsn(Ranges.front().first),
391 getLabelAfterInsn(Ranges.front().second));
393 addScopeRangeList(TheCU, Die, Ranges);
396 // Construct new DW_TAG_lexical_block for this scope and attach
397 // DW_AT_low_pc/DW_AT_high_pc labels.
399 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
400 LexicalScope *Scope) {
401 if (isLexicalScopeDIENull(Scope))
404 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
405 if (Scope->isAbstractScope())
408 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
413 // This scope represents inlined body of a function. Construct DIE to
414 // represent this concrete inlined copy of the function.
416 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
417 LexicalScope *Scope) {
418 assert(Scope->getScopeNode());
419 DIScope DS(Scope->getScopeNode());
420 DISubprogram InlinedSP = getDISubprogram(DS);
421 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
422 // was inlined from another compile unit.
423 DIE *OriginDIE = AbstractSPDies[InlinedSP];
424 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
426 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
427 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
429 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
431 InlinedSubprogramDIEs.insert(OriginDIE);
433 // Add the call site information to the DIE.
434 DILocation DL(Scope->getInlinedAt());
435 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
436 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
437 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
439 // Add name to the name table, we do this here because we're guaranteed
440 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
441 addSubprogramNames(InlinedSP, *ScopeDIE);
446 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
448 const LexicalScope &Scope,
449 DIE *&ObjectPointer) {
450 auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
451 if (DV.isObjectPointer())
452 ObjectPointer = Var.get();
456 DIE *DwarfDebug::createScopeChildrenDIE(
457 DwarfCompileUnit &TheCU, LexicalScope *Scope,
458 SmallVectorImpl<std::unique_ptr<DIE>> &Children) {
459 DIE *ObjectPointer = nullptr;
461 // Collect arguments for current function.
462 if (LScopes.isCurrentFunctionScope(Scope)) {
463 for (DbgVariable *ArgDV : CurrentFnArguments)
466 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
468 // If this is a variadic function, add an unspecified parameter.
469 DISubprogram SP(Scope->getScopeNode());
470 DITypeArray FnArgs = SP.getType().getTypeArray();
471 // If we have a single element of null, it is a function that returns void.
472 // If we have more than one elements and the last one is null, it is a
473 // variadic function.
474 if (FnArgs.getNumElements() > 1 &&
475 !FnArgs.getElement(FnArgs.getNumElements() - 1))
477 make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
480 // Collect lexical scope children first.
481 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
482 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
484 for (LexicalScope *LS : Scope->getChildren())
485 if (std::unique_ptr<DIE> Nested = constructScopeDIE(TheCU, LS))
486 Children.push_back(std::move(Nested));
487 return ObjectPointer;
490 void DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
491 LexicalScope *Scope, DIE &ScopeDIE) {
492 // We create children when the scope DIE is not null.
493 SmallVector<std::unique_ptr<DIE>, 8> Children;
494 if (DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children))
495 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
498 for (auto &I : Children)
499 ScopeDIE.addChild(std::move(I));
502 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
503 LexicalScope *Scope) {
504 assert(Scope && Scope->getScopeNode());
505 assert(Scope->isAbstractScope());
506 assert(!Scope->getInlinedAt());
508 DISubprogram SP(Scope->getScopeNode());
510 ProcessedSPNodes.insert(SP);
512 DIE *&AbsDef = AbstractSPDies[SP];
516 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
517 // was inlined from another compile unit.
518 DwarfCompileUnit &SPCU = *SPMap[SP];
521 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
522 // the important distinction that the DIDescriptor is not associated with the
523 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
524 // any). It could be refactored to some common utility function.
525 if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
526 ContextDIE = &SPCU.getUnitDie();
527 SPCU.getOrCreateSubprogramDIE(SPDecl);
529 ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
531 // Passing null as the associated DIDescriptor because the abstract definition
532 // shouldn't be found by lookup.
533 AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
535 SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
537 SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
538 createAndAddScopeChildren(SPCU, Scope, *AbsDef);
541 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
542 LexicalScope *Scope) {
543 assert(Scope && Scope->getScopeNode());
544 assert(!Scope->getInlinedAt());
545 assert(!Scope->isAbstractScope());
546 DISubprogram Sub(Scope->getScopeNode());
548 assert(Sub.isSubprogram());
550 ProcessedSPNodes.insert(Sub);
552 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
554 createAndAddScopeChildren(TheCU, Scope, ScopeDIE);
559 // Construct a DIE for this scope.
560 std::unique_ptr<DIE> DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
561 LexicalScope *Scope) {
562 if (!Scope || !Scope->getScopeNode())
565 DIScope DS(Scope->getScopeNode());
567 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
568 "Only handle inlined subprograms here, use "
569 "constructSubprogramScopeDIE for non-inlined "
572 SmallVector<std::unique_ptr<DIE>, 8> Children;
574 // We try to create the scope DIE first, then the children DIEs. This will
575 // avoid creating un-used children then removing them later when we find out
576 // the scope DIE is null.
577 std::unique_ptr<DIE> ScopeDIE;
578 if (Scope->getParent() && DS.isSubprogram()) {
579 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
582 // We create children when the scope DIE is not null.
583 createScopeChildrenDIE(TheCU, Scope, Children);
585 // Early exit when we know the scope DIE is going to be null.
586 if (isLexicalScopeDIENull(Scope))
589 // We create children here when we know the scope DIE is not going to be
590 // null and the children will be added to the scope DIE.
591 createScopeChildrenDIE(TheCU, Scope, Children);
593 // There is no need to emit empty lexical block DIE.
594 std::pair<ImportedEntityMap::const_iterator,
595 ImportedEntityMap::const_iterator> Range =
596 std::equal_range(ScopesWithImportedEntities.begin(),
597 ScopesWithImportedEntities.end(),
598 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
600 if (Children.empty() && Range.first == Range.second)
602 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
603 assert(ScopeDIE && "Scope DIE should not be null.");
604 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
606 constructImportedEntityDIE(TheCU, i->second, *ScopeDIE);
610 for (auto &I : Children)
611 ScopeDIE->addChild(std::move(I));
616 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
617 if (!GenerateGnuPubSections)
620 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
623 // Create new DwarfCompileUnit for the given metadata node with tag
624 // DW_TAG_compile_unit.
625 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
626 StringRef FN = DIUnit.getFilename();
627 CompilationDir = DIUnit.getDirectory();
629 auto OwnedUnit = make_unique<DwarfCompileUnit>(
630 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
631 DwarfCompileUnit &NewCU = *OwnedUnit;
632 DIE &Die = NewCU.getUnitDie();
633 InfoHolder.addUnit(std::move(OwnedUnit));
635 // LTO with assembly output shares a single line table amongst multiple CUs.
636 // To avoid the compilation directory being ambiguous, let the line table
637 // explicitly describe the directory of all files, never relying on the
638 // compilation directory.
639 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
640 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
641 NewCU.getUniqueID(), CompilationDir);
643 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
644 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
645 DIUnit.getLanguage());
646 NewCU.addString(Die, dwarf::DW_AT_name, FN);
648 if (!useSplitDwarf()) {
649 NewCU.initStmtList(DwarfLineSectionSym);
651 // If we're using split dwarf the compilation dir is going to be in the
652 // skeleton CU and so we don't need to duplicate it here.
653 if (!CompilationDir.empty())
654 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
656 addGnuPubAttributes(NewCU, Die);
659 if (DIUnit.isOptimized())
660 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
662 StringRef Flags = DIUnit.getFlags();
664 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
666 if (unsigned RVer = DIUnit.getRunTimeVersion())
667 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
668 dwarf::DW_FORM_data1, RVer);
673 if (useSplitDwarf()) {
674 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
675 DwarfInfoDWOSectionSym);
676 NewCU.setSkeleton(constructSkeletonCU(NewCU));
678 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
679 DwarfInfoSectionSym);
681 CUMap.insert(std::make_pair(DIUnit, &NewCU));
682 CUDieMap.insert(std::make_pair(&Die, &NewCU));
686 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
688 DIImportedEntity Module(N);
689 assert(Module.Verify());
690 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
691 constructImportedEntityDIE(TheCU, Module, *D);
694 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
695 const MDNode *N, DIE &Context) {
696 DIImportedEntity Module(N);
697 assert(Module.Verify());
698 return constructImportedEntityDIE(TheCU, Module, Context);
701 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
702 const DIImportedEntity &Module,
704 assert(Module.Verify() &&
705 "Use one of the MDNode * overloads to handle invalid metadata");
706 DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), Context, Module);
708 DIDescriptor Entity = resolve(Module.getEntity());
709 if (Entity.isNameSpace())
710 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
711 else if (Entity.isSubprogram())
712 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
713 else if (Entity.isType())
714 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
716 EntityDie = TheCU.getDIE(Entity);
717 TheCU.addSourceLine(IMDie, Module.getLineNumber(),
718 Module.getContext().getFilename(),
719 Module.getContext().getDirectory());
720 TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
721 StringRef Name = Module.getName();
723 TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
726 // Emit all Dwarf sections that should come prior to the content. Create
727 // global DIEs and emit initial debug info sections. This is invoked by
728 // the target AsmPrinter.
729 void DwarfDebug::beginModule() {
730 if (DisableDebugInfoPrinting)
733 const Module *M = MMI->getModule();
735 FunctionDIs = makeSubprogramMap(*M);
737 // If module has named metadata anchors then use them, otherwise scan the
738 // module using debug info finder to collect debug info.
739 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
742 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
744 // Emit initial sections so we can reference labels later.
747 SingleCU = CU_Nodes->getNumOperands() == 1;
749 for (MDNode *N : CU_Nodes->operands()) {
750 DICompileUnit CUNode(N);
751 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
752 DIArray ImportedEntities = CUNode.getImportedEntities();
753 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
754 ScopesWithImportedEntities.push_back(std::make_pair(
755 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
756 ImportedEntities.getElement(i)));
757 std::sort(ScopesWithImportedEntities.begin(),
758 ScopesWithImportedEntities.end(), less_first());
759 DIArray GVs = CUNode.getGlobalVariables();
760 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
761 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
762 DIArray SPs = CUNode.getSubprograms();
763 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
764 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
765 DIArray EnumTypes = CUNode.getEnumTypes();
766 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
767 DIType Ty(EnumTypes.getElement(i));
768 // The enum types array by design contains pointers to
769 // MDNodes rather than DIRefs. Unique them here.
770 DIType UniqueTy(resolve(Ty.getRef()));
771 CU.getOrCreateTypeDIE(UniqueTy);
773 DIArray RetainedTypes = CUNode.getRetainedTypes();
774 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
775 DIType Ty(RetainedTypes.getElement(i));
776 // The retained types array by design contains pointers to
777 // MDNodes rather than DIRefs. Unique them here.
778 DIType UniqueTy(resolve(Ty.getRef()));
779 CU.getOrCreateTypeDIE(UniqueTy);
781 // Emit imported_modules last so that the relevant context is already
783 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
784 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
787 // Tell MMI that we have debug info.
788 MMI->setDebugInfoAvailability(true);
790 // Prime section data.
791 SectionMap[Asm->getObjFileLowering().getTextSection()];
794 void DwarfDebug::finishVariableDefinitions() {
795 for (const auto &Var : ConcreteVariables) {
796 DIE *VariableDie = Var->getDIE();
798 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
799 // in the ConcreteVariables list, rather than looking it up again here.
800 // DIE::getUnit isn't simple - it walks parent pointers, etc.
801 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
803 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
804 if (AbsVar && AbsVar->getDIE()) {
805 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
808 Unit->applyVariableAttributes(*Var, *VariableDie);
812 void DwarfDebug::finishSubprogramDefinitions() {
813 const Module *M = MMI->getModule();
815 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
816 for (MDNode *N : CU_Nodes->operands()) {
817 DICompileUnit TheCU(N);
818 // Construct subprogram DIE and add variables DIEs.
819 DwarfCompileUnit *SPCU =
820 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
821 DIArray Subprograms = TheCU.getSubprograms();
822 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
823 DISubprogram SP(Subprograms.getElement(i));
824 // Perhaps the subprogram is in another CU (such as due to comdat
825 // folding, etc), in which case ignore it here.
826 if (SPMap[SP] != SPCU)
828 DIE *D = SPCU->getDIE(SP);
829 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
831 // If this subprogram has an abstract definition, reference that
832 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
835 // Lazily construct the subprogram if we didn't see either concrete or
836 // inlined versions during codegen.
837 D = SPCU->getOrCreateSubprogramDIE(SP);
838 // And attach the attributes
839 SPCU->applySubprogramAttributesToDefinition(SP, *D);
846 // Collect info for variables that were optimized out.
847 void DwarfDebug::collectDeadVariables() {
848 const Module *M = MMI->getModule();
850 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
851 for (MDNode *N : CU_Nodes->operands()) {
852 DICompileUnit TheCU(N);
853 // Construct subprogram DIE and add variables DIEs.
854 DwarfCompileUnit *SPCU =
855 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
856 assert(SPCU && "Unable to find Compile Unit!");
857 DIArray Subprograms = TheCU.getSubprograms();
858 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
859 DISubprogram SP(Subprograms.getElement(i));
860 if (ProcessedSPNodes.count(SP) != 0)
862 assert(SP.isSubprogram() &&
863 "CU's subprogram list contains a non-subprogram");
864 assert(SP.isDefinition() &&
865 "CU's subprogram list contains a subprogram declaration");
866 DIArray Variables = SP.getVariables();
867 if (Variables.getNumElements() == 0)
870 DIE *SPDIE = AbstractSPDies.lookup(SP);
872 SPDIE = SPCU->getDIE(SP);
874 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
875 DIVariable DV(Variables.getElement(vi));
876 assert(DV.isVariable());
877 DbgVariable NewVar(DV, this);
878 auto VariableDie = SPCU->constructVariableDIE(NewVar);
879 SPCU->applyVariableAttributes(NewVar, *VariableDie);
880 SPDIE->addChild(std::move(VariableDie));
887 void DwarfDebug::finalizeModuleInfo() {
888 finishSubprogramDefinitions();
890 finishVariableDefinitions();
892 // Collect info for variables that were optimized out.
893 collectDeadVariables();
895 // Handle anything that needs to be done on a per-unit basis after
896 // all other generation.
897 for (const auto &TheU : getUnits()) {
898 // Emit DW_AT_containing_type attribute to connect types with their
899 // vtable holding type.
900 TheU->constructContainingTypeDIEs();
902 // Add CU specific attributes if we need to add any.
903 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
904 // If we're splitting the dwarf out now that we've got the entire
905 // CU then add the dwo id to it.
906 DwarfCompileUnit *SkCU =
907 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
908 if (useSplitDwarf()) {
909 // Emit a unique identifier for this CU.
910 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
911 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
912 dwarf::DW_FORM_data8, ID);
913 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
914 dwarf::DW_FORM_data8, ID);
916 // We don't keep track of which addresses are used in which CU so this
917 // is a bit pessimistic under LTO.
918 if (!AddrPool.isEmpty())
919 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
920 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
921 DwarfAddrSectionSym);
922 if (!TheU->getRangeLists().empty())
923 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
924 dwarf::DW_AT_GNU_ranges_base,
925 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
928 // If we have code split among multiple sections or non-contiguous
929 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
930 // remain in the .o file, otherwise add a DW_AT_low_pc.
931 // FIXME: We should use ranges allow reordering of code ala
932 // .subsections_via_symbols in mach-o. This would mean turning on
933 // ranges for all subprogram DIEs for mach-o.
934 DwarfCompileUnit &U =
935 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
936 unsigned NumRanges = TheU->getRanges().size();
939 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
940 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
941 DwarfDebugRangeSectionSym);
943 // A DW_AT_low_pc attribute may also be specified in combination with
944 // DW_AT_ranges to specify the default base address for use in
945 // location lists (see Section 2.6.2) and range lists (see Section
947 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
950 RangeSpan &Range = TheU->getRanges().back();
951 attachLowHighPC(U, U.getUnitDie(), Range.getStart(), Range.getEnd());
957 // Compute DIE offsets and sizes.
958 InfoHolder.computeSizeAndOffsets();
960 SkeletonHolder.computeSizeAndOffsets();
963 void DwarfDebug::endSections() {
964 // Filter labels by section.
965 for (const SymbolCU &SCU : ArangeLabels) {
966 if (SCU.Sym->isInSection()) {
967 // Make a note of this symbol and it's section.
968 const MCSection *Section = &SCU.Sym->getSection();
969 if (!Section->getKind().isMetadata())
970 SectionMap[Section].push_back(SCU);
972 // Some symbols (e.g. common/bss on mach-o) can have no section but still
973 // appear in the output. This sucks as we rely on sections to build
974 // arange spans. We can do it without, but it's icky.
975 SectionMap[nullptr].push_back(SCU);
979 // Build a list of sections used.
980 std::vector<const MCSection *> Sections;
981 for (const auto &it : SectionMap) {
982 const MCSection *Section = it.first;
983 Sections.push_back(Section);
986 // Sort the sections into order.
987 // This is only done to ensure consistent output order across different runs.
988 std::sort(Sections.begin(), Sections.end(), SectionSort);
990 // Add terminating symbols for each section.
991 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
992 const MCSection *Section = Sections[ID];
993 MCSymbol *Sym = nullptr;
996 // We can't call MCSection::getLabelEndName, as it's only safe to do so
997 // if we know the section name up-front. For user-created sections, the
998 // resulting label may not be valid to use as a label. (section names can
999 // use a greater set of characters on some systems)
1000 Sym = Asm->GetTempSymbol("debug_end", ID);
1001 Asm->OutStreamer.SwitchSection(Section);
1002 Asm->OutStreamer.EmitLabel(Sym);
1005 // Insert a final terminator.
1006 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1010 // Emit all Dwarf sections that should come after the content.
1011 void DwarfDebug::endModule() {
1012 assert(CurFn == nullptr);
1013 assert(CurMI == nullptr);
1018 // End any existing sections.
1019 // TODO: Does this need to happen?
1022 // Finalize the debug info for the module.
1023 finalizeModuleInfo();
1027 // Emit all the DIEs into a debug info section.
1030 // Corresponding abbreviations into a abbrev section.
1031 emitAbbreviations();
1033 // Emit info into a debug aranges section.
1034 if (GenerateARangeSection)
1037 // Emit info into a debug ranges section.
1040 if (useSplitDwarf()) {
1043 emitDebugAbbrevDWO();
1046 // Emit DWO addresses.
1047 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1049 // Emit info into a debug loc section.
1052 // Emit info into the dwarf accelerator table sections.
1053 if (useDwarfAccelTables()) {
1056 emitAccelNamespaces();
1060 // Emit the pubnames and pubtypes sections if requested.
1061 if (HasDwarfPubSections) {
1062 emitDebugPubNames(GenerateGnuPubSections);
1063 emitDebugPubTypes(GenerateGnuPubSections);
1068 AbstractVariables.clear();
1070 // Reset these for the next Module if we have one.
1074 // Find abstract variable, if any, associated with Var.
1075 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1076 DIVariable &Cleansed) {
1077 LLVMContext &Ctx = DV->getContext();
1078 // More then one inlined variable corresponds to one abstract variable.
1079 // FIXME: This duplication of variables when inlining should probably be
1080 // removed. It's done to allow each DIVariable to describe its location
1081 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1082 // make it accurate then remove this duplication/cleansing stuff.
1083 Cleansed = cleanseInlinedVariable(DV, Ctx);
1084 auto I = AbstractVariables.find(Cleansed);
1085 if (I != AbstractVariables.end())
1086 return I->second.get();
1090 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1091 DIVariable Cleansed;
1092 return getExistingAbstractVariable(DV, Cleansed);
1095 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1096 LexicalScope *Scope) {
1097 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1098 addScopeVariable(Scope, AbsDbgVariable.get());
1099 AbstractVariables[Var] = std::move(AbsDbgVariable);
1102 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1103 const MDNode *ScopeNode) {
1104 DIVariable Cleansed = DV;
1105 if (getExistingAbstractVariable(DV, Cleansed))
1108 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1112 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1113 const MDNode *ScopeNode) {
1114 DIVariable Cleansed = DV;
1115 if (getExistingAbstractVariable(DV, Cleansed))
1118 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1119 createAbstractVariable(Cleansed, Scope);
1122 // If Var is a current function argument then add it to CurrentFnArguments list.
1123 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1124 if (!LScopes.isCurrentFunctionScope(Scope))
1126 DIVariable DV = Var->getVariable();
1127 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1129 unsigned ArgNo = DV.getArgNumber();
1133 size_t Size = CurrentFnArguments.size();
1135 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1136 // llvm::Function argument size is not good indicator of how many
1137 // arguments does the function have at source level.
1139 CurrentFnArguments.resize(ArgNo * 2);
1140 assert(!CurrentFnArguments[ArgNo - 1]);
1141 CurrentFnArguments[ArgNo - 1] = Var;
1145 // Collect variable information from side table maintained by MMI.
1146 void DwarfDebug::collectVariableInfoFromMMITable(
1147 SmallPtrSetImpl<const MDNode *> &Processed) {
1148 for (const auto &VI : MMI->getVariableDbgInfo()) {
1151 Processed.insert(VI.Var);
1152 DIVariable DV(VI.Var);
1153 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1155 // If variable scope is not found then skip this variable.
1159 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1160 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1161 DbgVariable *RegVar = ConcreteVariables.back().get();
1162 RegVar->setFrameIndex(VI.Slot);
1163 addScopeVariable(Scope, RegVar);
1167 // Get .debug_loc entry for the instruction range starting at MI.
1168 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1169 const MDNode *Var = MI->getDebugVariable();
1171 assert(MI->getNumOperands() == 3);
1172 if (MI->getOperand(0).isReg()) {
1173 MachineLocation MLoc;
1174 // If the second operand is an immediate, this is a
1175 // register-indirect address.
1176 if (!MI->getOperand(1).isImm())
1177 MLoc.set(MI->getOperand(0).getReg());
1179 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1180 return DebugLocEntry::Value(Var, MLoc);
1182 if (MI->getOperand(0).isImm())
1183 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1184 if (MI->getOperand(0).isFPImm())
1185 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1186 if (MI->getOperand(0).isCImm())
1187 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1189 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1192 /// Determine whether two variable pieces overlap.
1193 static bool piecesOverlap(DIVariable P1, DIVariable P2) {
1194 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1196 unsigned l1 = P1.getPieceOffset();
1197 unsigned l2 = P2.getPieceOffset();
1198 unsigned r1 = l1 + P1.getPieceSize();
1199 unsigned r2 = l2 + P2.getPieceSize();
1200 // True where [l1,r1[ and [r1,r2[ overlap.
1201 return (l1 < r2) && (l2 < r1);
1204 /// Build the location list for all DBG_VALUEs in the function that
1205 /// describe the same variable. If the ranges of several independent
1206 /// pieces of the same variable overlap partially, split them up and
1207 /// combine the ranges. The resulting DebugLocEntries are will have
1208 /// strict monotonically increasing begin addresses and will never
1213 // Ranges History [var, loc, piece ofs size]
1214 // 0 | [x, (reg0, piece 0, 32)]
1215 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1217 // 3 | [clobber reg0]
1218 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1222 // [0-1] [x, (reg0, piece 0, 32)]
1223 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1224 // [3-4] [x, (reg1, piece 32, 32)]
1225 // [4- ] [x, (mem, piece 0, 64)]
1227 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1228 const DbgValueHistoryMap::InstrRanges &Ranges) {
1229 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
1231 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1232 const MachineInstr *Begin = I->first;
1233 const MachineInstr *End = I->second;
1234 assert(Begin->isDebugValue() && "Invalid History entry");
1236 // Check if a variable is inaccessible in this range.
1237 if (Begin->getNumOperands() > 1 &&
1238 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
1243 // If this piece overlaps with any open ranges, truncate them.
1244 DIVariable DIVar = Begin->getDebugVariable();
1245 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
1246 [&](DebugLocEntry::Value R) {
1247 return piecesOverlap(DIVar, R.getVariable());
1249 OpenRanges.erase(Last, OpenRanges.end());
1251 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1252 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1254 const MCSymbol *EndLabel;
1256 EndLabel = getLabelAfterInsn(End);
1257 else if (std::next(I) == Ranges.end())
1258 EndLabel = FunctionEndSym;
1260 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1261 assert(EndLabel && "Forgot label after instruction ending a range!");
1263 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1265 auto Value = getDebugLocValue(Begin);
1266 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1267 bool couldMerge = false;
1269 // If this is a piece, it may belong to the current DebugLocEntry.
1270 if (DIVar.isVariablePiece()) {
1271 // Add this value to the list of open ranges.
1272 OpenRanges.push_back(Value);
1274 // Attempt to add the piece to the last entry.
1275 if (!DebugLoc.empty())
1276 if (DebugLoc.back().MergeValues(Loc))
1281 // Need to add a new DebugLocEntry. Add all values from still
1282 // valid non-overlapping pieces.
1283 if (OpenRanges.size())
1284 Loc.addValues(OpenRanges);
1286 DebugLoc.push_back(std::move(Loc));
1289 // Attempt to coalesce the ranges of two otherwise identical
1291 auto CurEntry = DebugLoc.rbegin();
1292 auto PrevEntry = std::next(CurEntry);
1293 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1294 DebugLoc.pop_back();
1296 DEBUG(dbgs() << "Values:\n";
1297 for (auto Value : CurEntry->getValues())
1298 Value.getVariable()->dump();
1299 dbgs() << "-----\n");
1304 // Find variables for each lexical scope.
1306 DwarfDebug::collectVariableInfo(SmallPtrSetImpl<const MDNode *> &Processed) {
1307 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1308 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1310 // Grab the variable info that was squirreled away in the MMI side-table.
1311 collectVariableInfoFromMMITable(Processed);
1313 for (const auto &I : DbgValues) {
1314 DIVariable DV(I.first);
1315 if (Processed.count(DV))
1318 // Instruction ranges, specifying where DV is accessible.
1319 const auto &Ranges = I.second;
1323 LexicalScope *Scope = nullptr;
1324 if (MDNode *IA = DV.getInlinedAt()) {
1325 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1326 Scope = LScopes.findInlinedScope(DebugLoc::get(
1327 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1329 Scope = LScopes.findLexicalScope(DV.getContext());
1330 // If variable scope is not found then skip this variable.
1334 Processed.insert(getEntireVariable(DV));
1335 const MachineInstr *MInsn = Ranges.front().first;
1336 assert(MInsn->isDebugValue() && "History must begin with debug value");
1337 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1338 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1339 DbgVariable *RegVar = ConcreteVariables.back().get();
1340 addScopeVariable(Scope, RegVar);
1342 // Check if the first DBG_VALUE is valid for the rest of the function.
1343 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1346 // Handle multiple DBG_VALUE instructions describing one variable.
1347 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1349 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1350 DebugLocList &LocList = DotDebugLocEntries.back();
1353 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1355 // Build the location list for this variable.
1356 buildLocationList(LocList.List, Ranges);
1359 // Collect info for variables that were optimized out.
1360 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1361 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1362 DIVariable DV(Variables.getElement(i));
1363 assert(DV.isVariable());
1364 if (!Processed.insert(DV))
1366 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1367 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1368 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1369 addScopeVariable(Scope, ConcreteVariables.back().get());
1374 // Return Label preceding the instruction.
1375 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1376 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1377 assert(Label && "Didn't insert label before instruction");
1381 // Return Label immediately following the instruction.
1382 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1383 return LabelsAfterInsn.lookup(MI);
1386 // Process beginning of an instruction.
1387 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1388 assert(CurMI == nullptr);
1390 // Check if source location changes, but ignore DBG_VALUE locations.
1391 if (!MI->isDebugValue()) {
1392 DebugLoc DL = MI->getDebugLoc();
1393 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1396 if (DL == PrologEndLoc) {
1397 Flags |= DWARF2_FLAG_PROLOGUE_END;
1398 PrologEndLoc = DebugLoc();
1400 if (PrologEndLoc.isUnknown())
1401 Flags |= DWARF2_FLAG_IS_STMT;
1403 if (!DL.isUnknown()) {
1404 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1405 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1407 recordSourceLine(0, 0, nullptr, 0);
1411 // Insert labels where requested.
1412 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1413 LabelsBeforeInsn.find(MI);
1416 if (I == LabelsBeforeInsn.end())
1419 // Label already assigned.
1424 PrevLabel = MMI->getContext().CreateTempSymbol();
1425 Asm->OutStreamer.EmitLabel(PrevLabel);
1427 I->second = PrevLabel;
1430 // Process end of an instruction.
1431 void DwarfDebug::endInstruction() {
1432 assert(CurMI != nullptr);
1433 // Don't create a new label after DBG_VALUE instructions.
1434 // They don't generate code.
1435 if (!CurMI->isDebugValue())
1436 PrevLabel = nullptr;
1438 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1439 LabelsAfterInsn.find(CurMI);
1443 if (I == LabelsAfterInsn.end())
1446 // Label already assigned.
1450 // We need a label after this instruction.
1452 PrevLabel = MMI->getContext().CreateTempSymbol();
1453 Asm->OutStreamer.EmitLabel(PrevLabel);
1455 I->second = PrevLabel;
1458 // Each LexicalScope has first instruction and last instruction to mark
1459 // beginning and end of a scope respectively. Create an inverse map that list
1460 // scopes starts (and ends) with an instruction. One instruction may start (or
1461 // end) multiple scopes. Ignore scopes that are not reachable.
1462 void DwarfDebug::identifyScopeMarkers() {
1463 SmallVector<LexicalScope *, 4> WorkList;
1464 WorkList.push_back(LScopes.getCurrentFunctionScope());
1465 while (!WorkList.empty()) {
1466 LexicalScope *S = WorkList.pop_back_val();
1468 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1469 if (!Children.empty())
1470 WorkList.append(Children.begin(), Children.end());
1472 if (S->isAbstractScope())
1475 for (const InsnRange &R : S->getRanges()) {
1476 assert(R.first && "InsnRange does not have first instruction!");
1477 assert(R.second && "InsnRange does not have second instruction!");
1478 requestLabelBeforeInsn(R.first);
1479 requestLabelAfterInsn(R.second);
1484 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1485 // First known non-DBG_VALUE and non-frame setup location marks
1486 // the beginning of the function body.
1487 for (const auto &MBB : *MF)
1488 for (const auto &MI : MBB)
1489 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1490 !MI.getDebugLoc().isUnknown())
1491 return MI.getDebugLoc();
1495 // Gather pre-function debug information. Assumes being called immediately
1496 // after the function entry point has been emitted.
1497 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1500 // If there's no debug info for the function we're not going to do anything.
1501 if (!MMI->hasDebugInfo())
1504 auto DI = FunctionDIs.find(MF->getFunction());
1505 if (DI == FunctionDIs.end())
1508 // Grab the lexical scopes for the function, if we don't have any of those
1509 // then we're not going to be able to do anything.
1510 LScopes.initialize(*MF);
1511 if (LScopes.empty())
1514 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1516 // Make sure that each lexical scope will have a begin/end label.
1517 identifyScopeMarkers();
1519 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1520 // belongs to so that we add to the correct per-cu line table in the
1522 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1523 // FnScope->getScopeNode() and DI->second should represent the same function,
1524 // though they may not be the same MDNode due to inline functions merged in
1525 // LTO where the debug info metadata still differs (either due to distinct
1526 // written differences - two versions of a linkonce_odr function
1527 // written/copied into two separate files, or some sub-optimal metadata that
1528 // isn't structurally identical (see: file path/name info from clang, which
1529 // includes the directory of the cpp file being built, even when the file name
1530 // is absolute (such as an <> lookup header)))
1531 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1532 assert(TheCU && "Unable to find compile unit!");
1533 if (Asm->OutStreamer.hasRawTextSupport())
1534 // Use a single line table if we are generating assembly.
1535 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1537 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1539 // Emit a label for the function so that we have a beginning address.
1540 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1541 // Assumes in correct section after the entry point.
1542 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1544 // Calculate history for local variables.
1545 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1548 // Request labels for the full history.
1549 for (const auto &I : DbgValues) {
1550 const auto &Ranges = I.second;
1554 // The first mention of a function argument gets the FunctionBeginSym
1555 // label, so arguments are visible when breaking at function entry.
1556 DIVariable DV(Ranges.front().first->getDebugVariable());
1557 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1558 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1559 if (!DV.isVariablePiece())
1560 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1562 // Mark all non-overlapping initial pieces.
1563 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1564 DIVariable Piece = I->first->getDebugVariable();
1565 if (std::all_of(Ranges.begin(), I,
1566 [&](DbgValueHistoryMap::InstrRange Pred){
1567 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1569 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1576 for (const auto &Range : Ranges) {
1577 requestLabelBeforeInsn(Range.first);
1579 requestLabelAfterInsn(Range.second);
1583 PrevInstLoc = DebugLoc();
1584 PrevLabel = FunctionBeginSym;
1586 // Record beginning of function.
1587 PrologEndLoc = findPrologueEndLoc(MF);
1588 if (!PrologEndLoc.isUnknown()) {
1589 DebugLoc FnStartDL =
1590 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1592 FnStartDL.getLine(), FnStartDL.getCol(),
1593 FnStartDL.getScope(MF->getFunction()->getContext()),
1594 // We'd like to list the prologue as "not statements" but GDB behaves
1595 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1596 DWARF2_FLAG_IS_STMT);
1600 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1601 if (addCurrentFnArgument(Var, LS))
1603 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1604 DIVariable DV = Var->getVariable();
1605 // Variables with positive arg numbers are parameters.
1606 if (unsigned ArgNum = DV.getArgNumber()) {
1607 // Keep all parameters in order at the start of the variable list to ensure
1608 // function types are correct (no out-of-order parameters)
1610 // This could be improved by only doing it for optimized builds (unoptimized
1611 // builds have the right order to begin with), searching from the back (this
1612 // would catch the unoptimized case quickly), or doing a binary search
1613 // rather than linear search.
1614 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1615 while (I != Vars.end()) {
1616 unsigned CurNum = (*I)->getVariable().getArgNumber();
1617 // A local (non-parameter) variable has been found, insert immediately
1621 // A later indexed parameter has been found, insert immediately before it.
1622 if (CurNum > ArgNum)
1626 Vars.insert(I, Var);
1630 Vars.push_back(Var);
1633 // Gather and emit post-function debug information.
1634 void DwarfDebug::endFunction(const MachineFunction *MF) {
1635 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1636 // though the beginFunction may not be called at all.
1637 // We should handle both cases.
1641 assert(CurFn == MF);
1642 assert(CurFn != nullptr);
1644 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1645 !FunctionDIs.count(MF->getFunction())) {
1646 // If we don't have a lexical scope for this function then there will
1647 // be a hole in the range information. Keep note of this by setting the
1648 // previously used section to nullptr.
1649 PrevSection = nullptr;
1655 // Define end label for subprogram.
1656 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1657 // Assumes in correct section after the entry point.
1658 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1660 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1661 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1663 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1664 collectVariableInfo(ProcessedVars);
1666 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1667 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1669 // Construct abstract scopes.
1670 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1671 DISubprogram SP(AScope->getScopeNode());
1672 assert(SP.isSubprogram());
1673 // Collect info for variables that were optimized out.
1674 DIArray Variables = SP.getVariables();
1675 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1676 DIVariable DV(Variables.getElement(i));
1677 assert(DV && DV.isVariable());
1678 if (!ProcessedVars.insert(DV))
1680 ensureAbstractVariableIsCreated(DV, DV.getContext());
1682 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1685 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1686 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1687 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1689 // Add the range of this function to the list of ranges for the CU.
1690 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1691 TheCU.addRange(std::move(Span));
1692 PrevSection = Asm->getCurrentSection();
1696 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1697 // DbgVariables except those that are also in AbstractVariables (since they
1698 // can be used cross-function)
1699 ScopeVariables.clear();
1700 CurrentFnArguments.clear();
1702 LabelsBeforeInsn.clear();
1703 LabelsAfterInsn.clear();
1704 PrevLabel = nullptr;
1708 // Register a source line with debug info. Returns the unique label that was
1709 // emitted and which provides correspondence to the source line list.
1710 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1715 unsigned Discriminator = 0;
1716 if (DIScope Scope = DIScope(S)) {
1717 assert(Scope.isScope());
1718 Fn = Scope.getFilename();
1719 Dir = Scope.getDirectory();
1720 if (Scope.isLexicalBlockFile())
1721 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1723 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1724 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1725 .getOrCreateSourceID(Fn, Dir);
1727 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1731 //===----------------------------------------------------------------------===//
1733 //===----------------------------------------------------------------------===//
1735 // Emit initial Dwarf sections with a label at the start of each one.
1736 void DwarfDebug::emitSectionLabels() {
1737 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1739 // Dwarf sections base addresses.
1740 DwarfInfoSectionSym =
1741 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1742 if (useSplitDwarf()) {
1743 DwarfInfoDWOSectionSym =
1744 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1745 DwarfTypesDWOSectionSym =
1746 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1748 DwarfAbbrevSectionSym =
1749 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1750 if (useSplitDwarf())
1751 DwarfAbbrevDWOSectionSym = emitSectionSym(
1752 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1753 if (GenerateARangeSection)
1754 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1756 DwarfLineSectionSym =
1757 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1758 if (GenerateGnuPubSections) {
1759 DwarfGnuPubNamesSectionSym =
1760 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1761 DwarfGnuPubTypesSectionSym =
1762 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1763 } else if (HasDwarfPubSections) {
1764 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1765 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1768 DwarfStrSectionSym =
1769 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1770 if (useSplitDwarf()) {
1771 DwarfStrDWOSectionSym =
1772 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1773 DwarfAddrSectionSym =
1774 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1775 DwarfDebugLocSectionSym =
1776 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1778 DwarfDebugLocSectionSym =
1779 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1780 DwarfDebugRangeSectionSym =
1781 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1784 // Recursively emits a debug information entry.
1785 void DwarfDebug::emitDIE(DIE &Die) {
1786 // Get the abbreviation for this DIE.
1787 const DIEAbbrev &Abbrev = Die.getAbbrev();
1789 // Emit the code (index) for the abbreviation.
1790 if (Asm->isVerbose())
1791 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1792 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1793 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1794 dwarf::TagString(Abbrev.getTag()));
1795 Asm->EmitULEB128(Abbrev.getNumber());
1797 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1798 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1800 // Emit the DIE attribute values.
1801 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1802 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1803 dwarf::Form Form = AbbrevData[i].getForm();
1804 assert(Form && "Too many attributes for DIE (check abbreviation)");
1806 if (Asm->isVerbose()) {
1807 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1808 if (Attr == dwarf::DW_AT_accessibility)
1809 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1810 cast<DIEInteger>(Values[i])->getValue()));
1813 // Emit an attribute using the defined form.
1814 Values[i]->EmitValue(Asm, Form);
1817 // Emit the DIE children if any.
1818 if (Abbrev.hasChildren()) {
1819 for (auto &Child : Die.getChildren())
1822 Asm->OutStreamer.AddComment("End Of Children Mark");
1827 // Emit the debug info section.
1828 void DwarfDebug::emitDebugInfo() {
1829 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1831 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1834 // Emit the abbreviation section.
1835 void DwarfDebug::emitAbbreviations() {
1836 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1838 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1841 // Emit the last address of the section and the end of the line matrix.
1842 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1843 // Define last address of section.
1844 Asm->OutStreamer.AddComment("Extended Op");
1847 Asm->OutStreamer.AddComment("Op size");
1848 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1849 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1850 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1852 Asm->OutStreamer.AddComment("Section end label");
1854 Asm->OutStreamer.EmitSymbolValue(
1855 Asm->GetTempSymbol("section_end", SectionEnd),
1856 Asm->getDataLayout().getPointerSize());
1858 // Mark end of matrix.
1859 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1865 // Emit visible names into a hashed accelerator table section.
1866 void DwarfDebug::emitAccelNames() {
1867 AccelNames.FinalizeTable(Asm, "Names");
1868 Asm->OutStreamer.SwitchSection(
1869 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1870 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1871 Asm->OutStreamer.EmitLabel(SectionBegin);
1873 // Emit the full data.
1874 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1877 // Emit objective C classes and categories into a hashed accelerator table
1879 void DwarfDebug::emitAccelObjC() {
1880 AccelObjC.FinalizeTable(Asm, "ObjC");
1881 Asm->OutStreamer.SwitchSection(
1882 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1883 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1884 Asm->OutStreamer.EmitLabel(SectionBegin);
1886 // Emit the full data.
1887 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1890 // Emit namespace dies into a hashed accelerator table.
1891 void DwarfDebug::emitAccelNamespaces() {
1892 AccelNamespace.FinalizeTable(Asm, "namespac");
1893 Asm->OutStreamer.SwitchSection(
1894 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1895 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1896 Asm->OutStreamer.EmitLabel(SectionBegin);
1898 // Emit the full data.
1899 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1902 // Emit type dies into a hashed accelerator table.
1903 void DwarfDebug::emitAccelTypes() {
1905 AccelTypes.FinalizeTable(Asm, "types");
1906 Asm->OutStreamer.SwitchSection(
1907 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1908 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1909 Asm->OutStreamer.EmitLabel(SectionBegin);
1911 // Emit the full data.
1912 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1915 // Public name handling.
1916 // The format for the various pubnames:
1918 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1919 // for the DIE that is named.
1921 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1922 // into the CU and the index value is computed according to the type of value
1923 // for the DIE that is named.
1925 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1926 // it's the offset within the debug_info/debug_types dwo section, however, the
1927 // reference in the pubname header doesn't change.
1929 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1930 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1932 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1934 // We could have a specification DIE that has our most of our knowledge,
1935 // look for that now.
1936 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1938 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1939 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1940 Linkage = dwarf::GIEL_EXTERNAL;
1941 } else if (Die->findAttribute(dwarf::DW_AT_external))
1942 Linkage = dwarf::GIEL_EXTERNAL;
1944 switch (Die->getTag()) {
1945 case dwarf::DW_TAG_class_type:
1946 case dwarf::DW_TAG_structure_type:
1947 case dwarf::DW_TAG_union_type:
1948 case dwarf::DW_TAG_enumeration_type:
1949 return dwarf::PubIndexEntryDescriptor(
1950 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1951 ? dwarf::GIEL_STATIC
1952 : dwarf::GIEL_EXTERNAL);
1953 case dwarf::DW_TAG_typedef:
1954 case dwarf::DW_TAG_base_type:
1955 case dwarf::DW_TAG_subrange_type:
1956 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1957 case dwarf::DW_TAG_namespace:
1958 return dwarf::GIEK_TYPE;
1959 case dwarf::DW_TAG_subprogram:
1960 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1961 case dwarf::DW_TAG_constant:
1962 case dwarf::DW_TAG_variable:
1963 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1964 case dwarf::DW_TAG_enumerator:
1965 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1966 dwarf::GIEL_STATIC);
1968 return dwarf::GIEK_NONE;
1972 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1974 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1975 const MCSection *PSec =
1976 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1977 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1979 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1982 void DwarfDebug::emitDebugPubSection(
1983 bool GnuStyle, const MCSection *PSec, StringRef Name,
1984 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1985 for (const auto &NU : CUMap) {
1986 DwarfCompileUnit *TheU = NU.second;
1988 const auto &Globals = (TheU->*Accessor)();
1990 if (Globals.empty())
1993 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1995 unsigned ID = TheU->getUniqueID();
1997 // Start the dwarf pubnames section.
1998 Asm->OutStreamer.SwitchSection(PSec);
2001 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2002 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2003 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2004 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2006 Asm->OutStreamer.EmitLabel(BeginLabel);
2008 Asm->OutStreamer.AddComment("DWARF Version");
2009 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2011 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2012 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2014 Asm->OutStreamer.AddComment("Compilation Unit Length");
2015 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2017 // Emit the pubnames for this compilation unit.
2018 for (const auto &GI : Globals) {
2019 const char *Name = GI.getKeyData();
2020 const DIE *Entity = GI.second;
2022 Asm->OutStreamer.AddComment("DIE offset");
2023 Asm->EmitInt32(Entity->getOffset());
2026 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2027 Asm->OutStreamer.AddComment(
2028 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2029 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2030 Asm->EmitInt8(Desc.toBits());
2033 Asm->OutStreamer.AddComment("External Name");
2034 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2037 Asm->OutStreamer.AddComment("End Mark");
2039 Asm->OutStreamer.EmitLabel(EndLabel);
2043 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2044 const MCSection *PSec =
2045 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2046 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2048 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2051 // Emit visible names into a debug str section.
2052 void DwarfDebug::emitDebugStr() {
2053 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2054 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2057 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2058 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2059 const DITypeIdentifierMap &Map,
2060 ArrayRef<DebugLocEntry::Value> Values) {
2061 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
2062 return P.isVariablePiece();
2063 }) && "all values are expected to be pieces");
2064 assert(std::is_sorted(Values.begin(), Values.end()) &&
2065 "pieces are expected to be sorted");
2067 unsigned Offset = 0;
2068 for (auto Piece : Values) {
2069 DIVariable Var = Piece.getVariable();
2070 unsigned PieceOffset = Var.getPieceOffset();
2071 unsigned PieceSize = Var.getPieceSize();
2072 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
2073 if (Offset < PieceOffset) {
2074 // The DWARF spec seriously mandates pieces with no locations for gaps.
2075 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2076 Offset += PieceOffset-Offset;
2079 Offset += PieceSize;
2081 const unsigned SizeOfByte = 8;
2082 assert(!Var.isIndirect() && "indirect address for piece");
2084 unsigned VarSize = Var.getSizeInBits(Map);
2085 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2086 && "piece is larger than or outside of variable");
2087 assert(PieceSize*SizeOfByte != VarSize
2088 && "piece covers entire variable");
2090 if (Piece.isLocation() && Piece.getLoc().isReg())
2091 Asm->EmitDwarfRegOpPiece(Streamer,
2093 PieceSize*SizeOfByte);
2095 emitDebugLocValue(Streamer, Piece);
2096 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2102 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2103 const DebugLocEntry &Entry) {
2104 const DebugLocEntry::Value Value = Entry.getValues()[0];
2105 if (Value.isVariablePiece())
2106 // Emit all pieces that belong to the same variable and range.
2107 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2109 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2110 emitDebugLocValue(Streamer, Value);
2113 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2114 const DebugLocEntry::Value &Value) {
2115 DIVariable DV = Value.getVariable();
2117 if (Value.isInt()) {
2118 DIBasicType BTy(resolve(DV.getType()));
2119 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2120 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2121 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2122 Streamer.EmitSLEB128(Value.getInt());
2124 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2125 Streamer.EmitULEB128(Value.getInt());
2127 } else if (Value.isLocation()) {
2128 MachineLocation Loc = Value.getLoc();
2129 if (!DV.hasComplexAddress())
2131 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2133 // Complex address entry.
2134 unsigned N = DV.getNumAddrElements();
2136 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2137 if (Loc.getOffset()) {
2139 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2140 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2141 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2142 Streamer.EmitSLEB128(DV.getAddrElement(1));
2144 // If first address element is OpPlus then emit
2145 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2146 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2147 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2151 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2154 // Emit remaining complex address elements.
2155 for (; i < N; ++i) {
2156 uint64_t Element = DV.getAddrElement(i);
2157 if (Element == DIBuilder::OpPlus) {
2158 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2159 Streamer.EmitULEB128(DV.getAddrElement(++i));
2160 } else if (Element == DIBuilder::OpDeref) {
2162 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2163 } else if (Element == DIBuilder::OpPiece) {
2165 // handled in emitDebugLocEntry.
2167 llvm_unreachable("unknown Opcode found in complex address");
2171 // else ... ignore constant fp. There is not any good way to
2172 // to represent them here in dwarf.
2176 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2177 Asm->OutStreamer.AddComment("Loc expr size");
2178 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2179 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2180 Asm->EmitLabelDifference(end, begin, 2);
2181 Asm->OutStreamer.EmitLabel(begin);
2183 APByteStreamer Streamer(*Asm);
2184 emitDebugLocEntry(Streamer, Entry);
2186 Asm->OutStreamer.EmitLabel(end);
2189 // Emit locations into the debug loc section.
2190 void DwarfDebug::emitDebugLoc() {
2191 // Start the dwarf loc section.
2192 Asm->OutStreamer.SwitchSection(
2193 Asm->getObjFileLowering().getDwarfLocSection());
2194 unsigned char Size = Asm->getDataLayout().getPointerSize();
2195 for (const auto &DebugLoc : DotDebugLocEntries) {
2196 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2197 const DwarfCompileUnit *CU = DebugLoc.CU;
2198 assert(!CU->getRanges().empty());
2199 for (const auto &Entry : DebugLoc.List) {
2200 // Set up the range. This range is relative to the entry point of the
2201 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2202 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2203 if (CU->getRanges().size() == 1) {
2204 // Grab the begin symbol from the first range as our base.
2205 const MCSymbol *Base = CU->getRanges()[0].getStart();
2206 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2207 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2209 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2210 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2213 emitDebugLocEntryLocation(Entry);
2215 Asm->OutStreamer.EmitIntValue(0, Size);
2216 Asm->OutStreamer.EmitIntValue(0, Size);
2220 void DwarfDebug::emitDebugLocDWO() {
2221 Asm->OutStreamer.SwitchSection(
2222 Asm->getObjFileLowering().getDwarfLocDWOSection());
2223 for (const auto &DebugLoc : DotDebugLocEntries) {
2224 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2225 for (const auto &Entry : DebugLoc.List) {
2226 // Just always use start_length for now - at least that's one address
2227 // rather than two. We could get fancier and try to, say, reuse an
2228 // address we know we've emitted elsewhere (the start of the function?
2229 // The start of the CU or CU subrange that encloses this range?)
2230 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2231 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2232 Asm->EmitULEB128(idx);
2233 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2235 emitDebugLocEntryLocation(Entry);
2237 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2242 const MCSymbol *Start, *End;
2245 // Emit a debug aranges section, containing a CU lookup for any
2246 // address we can tie back to a CU.
2247 void DwarfDebug::emitDebugARanges() {
2248 // Start the dwarf aranges section.
2249 Asm->OutStreamer.SwitchSection(
2250 Asm->getObjFileLowering().getDwarfARangesSection());
2252 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2256 // Build a list of sections used.
2257 std::vector<const MCSection *> Sections;
2258 for (const auto &it : SectionMap) {
2259 const MCSection *Section = it.first;
2260 Sections.push_back(Section);
2263 // Sort the sections into order.
2264 // This is only done to ensure consistent output order across different runs.
2265 std::sort(Sections.begin(), Sections.end(), SectionSort);
2267 // Build a set of address spans, sorted by CU.
2268 for (const MCSection *Section : Sections) {
2269 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2270 if (List.size() < 2)
2273 // Sort the symbols by offset within the section.
2274 std::sort(List.begin(), List.end(),
2275 [&](const SymbolCU &A, const SymbolCU &B) {
2276 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2277 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2279 // Symbols with no order assigned should be placed at the end.
2280 // (e.g. section end labels)
2288 // If we have no section (e.g. common), just write out
2289 // individual spans for each symbol.
2291 for (const SymbolCU &Cur : List) {
2293 Span.Start = Cur.Sym;
2296 Spans[Cur.CU].push_back(Span);
2299 // Build spans between each label.
2300 const MCSymbol *StartSym = List[0].Sym;
2301 for (size_t n = 1, e = List.size(); n < e; n++) {
2302 const SymbolCU &Prev = List[n - 1];
2303 const SymbolCU &Cur = List[n];
2305 // Try and build the longest span we can within the same CU.
2306 if (Cur.CU != Prev.CU) {
2308 Span.Start = StartSym;
2310 Spans[Prev.CU].push_back(Span);
2317 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2319 // Build a list of CUs used.
2320 std::vector<DwarfCompileUnit *> CUs;
2321 for (const auto &it : Spans) {
2322 DwarfCompileUnit *CU = it.first;
2326 // Sort the CU list (again, to ensure consistent output order).
2327 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2328 return A->getUniqueID() < B->getUniqueID();
2331 // Emit an arange table for each CU we used.
2332 for (DwarfCompileUnit *CU : CUs) {
2333 std::vector<ArangeSpan> &List = Spans[CU];
2335 // Emit size of content not including length itself.
2336 unsigned ContentSize =
2337 sizeof(int16_t) + // DWARF ARange version number
2338 sizeof(int32_t) + // Offset of CU in the .debug_info section
2339 sizeof(int8_t) + // Pointer Size (in bytes)
2340 sizeof(int8_t); // Segment Size (in bytes)
2342 unsigned TupleSize = PtrSize * 2;
2344 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2346 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2348 ContentSize += Padding;
2349 ContentSize += (List.size() + 1) * TupleSize;
2351 // For each compile unit, write the list of spans it covers.
2352 Asm->OutStreamer.AddComment("Length of ARange Set");
2353 Asm->EmitInt32(ContentSize);
2354 Asm->OutStreamer.AddComment("DWARF Arange version number");
2355 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2356 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2357 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2358 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2359 Asm->EmitInt8(PtrSize);
2360 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2363 Asm->OutStreamer.EmitFill(Padding, 0xff);
2365 for (const ArangeSpan &Span : List) {
2366 Asm->EmitLabelReference(Span.Start, PtrSize);
2368 // Calculate the size as being from the span start to it's end.
2370 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2372 // For symbols without an end marker (e.g. common), we
2373 // write a single arange entry containing just that one symbol.
2374 uint64_t Size = SymSize[Span.Start];
2378 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2382 Asm->OutStreamer.AddComment("ARange terminator");
2383 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2384 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2388 // Emit visible names into a debug ranges section.
2389 void DwarfDebug::emitDebugRanges() {
2390 // Start the dwarf ranges section.
2391 Asm->OutStreamer.SwitchSection(
2392 Asm->getObjFileLowering().getDwarfRangesSection());
2394 // Size for our labels.
2395 unsigned char Size = Asm->getDataLayout().getPointerSize();
2397 // Grab the specific ranges for the compile units in the module.
2398 for (const auto &I : CUMap) {
2399 DwarfCompileUnit *TheCU = I.second;
2401 // Iterate over the misc ranges for the compile units in the module.
2402 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2403 // Emit our symbol so we can find the beginning of the range.
2404 Asm->OutStreamer.EmitLabel(List.getSym());
2406 for (const RangeSpan &Range : List.getRanges()) {
2407 const MCSymbol *Begin = Range.getStart();
2408 const MCSymbol *End = Range.getEnd();
2409 assert(Begin && "Range without a begin symbol?");
2410 assert(End && "Range without an end symbol?");
2411 if (TheCU->getRanges().size() == 1) {
2412 // Grab the begin symbol from the first range as our base.
2413 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2414 Asm->EmitLabelDifference(Begin, Base, Size);
2415 Asm->EmitLabelDifference(End, Base, Size);
2417 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2418 Asm->OutStreamer.EmitSymbolValue(End, Size);
2422 // And terminate the list with two 0 values.
2423 Asm->OutStreamer.EmitIntValue(0, Size);
2424 Asm->OutStreamer.EmitIntValue(0, Size);
2427 // Now emit a range for the CU itself.
2428 if (TheCU->getRanges().size() > 1) {
2429 Asm->OutStreamer.EmitLabel(
2430 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2431 for (const RangeSpan &Range : TheCU->getRanges()) {
2432 const MCSymbol *Begin = Range.getStart();
2433 const MCSymbol *End = Range.getEnd();
2434 assert(Begin && "Range without a begin symbol?");
2435 assert(End && "Range without an end symbol?");
2436 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2437 Asm->OutStreamer.EmitSymbolValue(End, Size);
2439 // And terminate the list with two 0 values.
2440 Asm->OutStreamer.EmitIntValue(0, Size);
2441 Asm->OutStreamer.EmitIntValue(0, Size);
2446 // DWARF5 Experimental Separate Dwarf emitters.
2448 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2449 std::unique_ptr<DwarfUnit> NewU) {
2450 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2451 U.getCUNode().getSplitDebugFilename());
2453 if (!CompilationDir.empty())
2454 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2456 addGnuPubAttributes(*NewU, Die);
2458 SkeletonHolder.addUnit(std::move(NewU));
2461 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2462 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2463 // DW_AT_addr_base, DW_AT_ranges_base.
2464 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2466 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2467 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2468 DwarfCompileUnit &NewCU = *OwnedUnit;
2469 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2470 DwarfInfoSectionSym);
2472 NewCU.initStmtList(DwarfLineSectionSym);
2474 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2479 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2480 // compile units that would normally be in debug_info.
2481 void DwarfDebug::emitDebugInfoDWO() {
2482 assert(useSplitDwarf() && "No split dwarf debug info?");
2483 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2484 // emit relocations into the dwo file.
2485 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2488 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2489 // abbreviations for the .debug_info.dwo section.
2490 void DwarfDebug::emitDebugAbbrevDWO() {
2491 assert(useSplitDwarf() && "No split dwarf?");
2492 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2495 void DwarfDebug::emitDebugLineDWO() {
2496 assert(useSplitDwarf() && "No split dwarf?");
2497 Asm->OutStreamer.SwitchSection(
2498 Asm->getObjFileLowering().getDwarfLineDWOSection());
2499 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2502 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2503 // string section and is identical in format to traditional .debug_str
2505 void DwarfDebug::emitDebugStrDWO() {
2506 assert(useSplitDwarf() && "No split dwarf?");
2507 const MCSection *OffSec =
2508 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2509 const MCSymbol *StrSym = DwarfStrSectionSym;
2510 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2514 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2515 if (!useSplitDwarf())
2518 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2519 return &SplitTypeUnitFileTable;
2522 static uint64_t makeTypeSignature(StringRef Identifier) {
2524 Hash.update(Identifier);
2525 // ... take the least significant 8 bytes and return those. Our MD5
2526 // implementation always returns its results in little endian, swap bytes
2528 MD5::MD5Result Result;
2530 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2533 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2534 StringRef Identifier, DIE &RefDie,
2535 DICompositeType CTy) {
2536 // Fast path if we're building some type units and one has already used the
2537 // address pool we know we're going to throw away all this work anyway, so
2538 // don't bother building dependent types.
2539 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2542 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2544 CU.addDIETypeSignature(RefDie, *TU);
2548 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2549 AddrPool.resetUsedFlag();
2551 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2552 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2553 this, &InfoHolder, getDwoLineTable(CU));
2554 DwarfTypeUnit &NewTU = *OwnedUnit;
2555 DIE &UnitDie = NewTU.getUnitDie();
2557 TypeUnitsUnderConstruction.push_back(
2558 std::make_pair(std::move(OwnedUnit), CTy));
2560 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2563 uint64_t Signature = makeTypeSignature(Identifier);
2564 NewTU.setTypeSignature(Signature);
2566 if (useSplitDwarf())
2567 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2568 DwarfTypesDWOSectionSym);
2570 CU.applyStmtList(UnitDie);
2572 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2575 NewTU.setType(NewTU.createTypeDIE(CTy));
2578 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2579 TypeUnitsUnderConstruction.clear();
2581 // Types referencing entries in the address table cannot be placed in type
2583 if (AddrPool.hasBeenUsed()) {
2585 // Remove all the types built while building this type.
2586 // This is pessimistic as some of these types might not be dependent on
2587 // the type that used an address.
2588 for (const auto &TU : TypeUnitsToAdd)
2589 DwarfTypeUnits.erase(TU.second);
2591 // Construct this type in the CU directly.
2592 // This is inefficient because all the dependent types will be rebuilt
2593 // from scratch, including building them in type units, discovering that
2594 // they depend on addresses, throwing them out and rebuilding them.
2595 CU.constructTypeDIE(RefDie, CTy);
2599 // If the type wasn't dependent on fission addresses, finish adding the type
2600 // and all its dependent types.
2601 for (auto &TU : TypeUnitsToAdd)
2602 InfoHolder.addUnit(std::move(TU.first));
2604 CU.addDIETypeSignature(RefDie, NewTU);
2607 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2608 const MCSymbol *Begin, const MCSymbol *End) {
2609 assert(Begin && "Begin label should not be null!");
2610 assert(End && "End label should not be null!");
2611 assert(Begin->isDefined() && "Invalid starting label");
2612 assert(End->isDefined() && "Invalid end label");
2614 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2615 if (DwarfVersion < 4)
2616 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2618 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2621 // Accelerator table mutators - add each name along with its companion
2622 // DIE to the proper table while ensuring that the name that we're going
2623 // to reference is in the string table. We do this since the names we
2624 // add may not only be identical to the names in the DIE.
2625 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2626 if (!useDwarfAccelTables())
2628 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2632 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2633 if (!useDwarfAccelTables())
2635 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2639 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2640 if (!useDwarfAccelTables())
2642 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2646 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2647 if (!useDwarfAccelTables())
2649 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),