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 SmallVectorImpl<InsnRange>::const_iterator RI = Ranges.begin();
350 MCSymbol *End = getLabelAfterInsn(RI->second);
354 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
355 dwarf::Attribute A, const MCSymbol *L,
356 const MCSymbol *Sec) {
357 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
358 U.addSectionLabel(D, A, L);
360 U.addSectionDelta(D, A, L, Sec);
363 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
364 const SmallVectorImpl<InsnRange> &Range) {
365 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
366 // emitting it appropriately.
367 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
369 // Under fission, ranges are specified by constant offsets relative to the
370 // CU's DW_AT_GNU_ranges_base.
372 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
373 DwarfDebugRangeSectionSym);
375 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
376 DwarfDebugRangeSectionSym);
378 RangeSpanList List(RangeSym);
379 for (const InsnRange &R : Range) {
380 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
381 List.addRange(std::move(Span));
384 // Add the range list to the set of ranges to be emitted.
385 TheCU.addRangeList(std::move(List));
388 void DwarfDebug::attachRangesOrLowHighPC(DwarfCompileUnit &TheCU, DIE &Die,
389 const SmallVectorImpl<InsnRange> &Ranges) {
390 assert(!Ranges.empty());
391 if (Ranges.size() == 1)
392 attachLowHighPC(TheCU, Die, getLabelBeforeInsn(Ranges.front().first),
393 getLabelAfterInsn(Ranges.front().second));
395 addScopeRangeList(TheCU, Die, Ranges);
398 // Construct new DW_TAG_lexical_block for this scope and attach
399 // DW_AT_low_pc/DW_AT_high_pc labels.
401 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
402 LexicalScope *Scope) {
403 if (isLexicalScopeDIENull(Scope))
406 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
407 if (Scope->isAbstractScope())
410 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
415 // This scope represents inlined body of a function. Construct DIE to
416 // represent this concrete inlined copy of the function.
418 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
419 LexicalScope *Scope) {
420 assert(Scope->getScopeNode());
421 DIScope DS(Scope->getScopeNode());
422 DISubprogram InlinedSP = getDISubprogram(DS);
423 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
424 // was inlined from another compile unit.
425 DIE *OriginDIE = AbstractSPDies[InlinedSP];
426 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
428 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
429 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
431 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
433 InlinedSubprogramDIEs.insert(OriginDIE);
435 // Add the call site information to the DIE.
436 DILocation DL(Scope->getInlinedAt());
437 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
438 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
439 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
441 // Add name to the name table, we do this here because we're guaranteed
442 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
443 addSubprogramNames(InlinedSP, *ScopeDIE);
448 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
450 const LexicalScope &Scope,
451 DIE *&ObjectPointer) {
452 auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
453 if (DV.isObjectPointer())
454 ObjectPointer = Var.get();
458 DIE *DwarfDebug::createScopeChildrenDIE(
459 DwarfCompileUnit &TheCU, LexicalScope *Scope,
460 SmallVectorImpl<std::unique_ptr<DIE>> &Children) {
461 DIE *ObjectPointer = nullptr;
463 // Collect arguments for current function.
464 if (LScopes.isCurrentFunctionScope(Scope)) {
465 for (DbgVariable *ArgDV : CurrentFnArguments)
468 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
470 // If this is a variadic function, add an unspecified parameter.
471 DISubprogram SP(Scope->getScopeNode());
472 DITypeArray FnArgs = SP.getType().getTypeArray();
473 // If we have a single element of null, it is a function that returns void.
474 // If we have more than one elements and the last one is null, it is a
475 // variadic function.
476 if (FnArgs.getNumElements() > 1 &&
477 !FnArgs.getElement(FnArgs.getNumElements() - 1))
479 make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
482 // Collect lexical scope children first.
483 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
484 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
486 for (LexicalScope *LS : Scope->getChildren())
487 if (std::unique_ptr<DIE> Nested = constructScopeDIE(TheCU, LS))
488 Children.push_back(std::move(Nested));
489 return ObjectPointer;
492 void DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
493 LexicalScope *Scope, DIE &ScopeDIE) {
494 // We create children when the scope DIE is not null.
495 SmallVector<std::unique_ptr<DIE>, 8> Children;
496 if (DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children))
497 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
500 for (auto &I : Children)
501 ScopeDIE.addChild(std::move(I));
504 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
505 LexicalScope *Scope) {
506 assert(Scope && Scope->getScopeNode());
507 assert(Scope->isAbstractScope());
508 assert(!Scope->getInlinedAt());
510 DISubprogram SP(Scope->getScopeNode());
512 ProcessedSPNodes.insert(SP);
514 DIE *&AbsDef = AbstractSPDies[SP];
518 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
519 // was inlined from another compile unit.
520 DwarfCompileUnit &SPCU = *SPMap[SP];
523 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
524 // the important distinction that the DIDescriptor is not associated with the
525 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
526 // any). It could be refactored to some common utility function.
527 if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
528 ContextDIE = &SPCU.getUnitDie();
529 SPCU.getOrCreateSubprogramDIE(SPDecl);
531 ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
533 // Passing null as the associated DIDescriptor because the abstract definition
534 // shouldn't be found by lookup.
535 AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
537 SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
539 SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
540 createAndAddScopeChildren(SPCU, Scope, *AbsDef);
543 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
544 LexicalScope *Scope) {
545 assert(Scope && Scope->getScopeNode());
546 assert(!Scope->getInlinedAt());
547 assert(!Scope->isAbstractScope());
548 DISubprogram Sub(Scope->getScopeNode());
550 assert(Sub.isSubprogram());
552 ProcessedSPNodes.insert(Sub);
554 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
556 createAndAddScopeChildren(TheCU, Scope, ScopeDIE);
561 // Construct a DIE for this scope.
562 std::unique_ptr<DIE> DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
563 LexicalScope *Scope) {
564 if (!Scope || !Scope->getScopeNode())
567 DIScope DS(Scope->getScopeNode());
569 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
570 "Only handle inlined subprograms here, use "
571 "constructSubprogramScopeDIE for non-inlined "
574 SmallVector<std::unique_ptr<DIE>, 8> Children;
576 // We try to create the scope DIE first, then the children DIEs. This will
577 // avoid creating un-used children then removing them later when we find out
578 // the scope DIE is null.
579 std::unique_ptr<DIE> ScopeDIE;
580 if (Scope->getParent() && DS.isSubprogram()) {
581 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
584 // We create children when the scope DIE is not null.
585 createScopeChildrenDIE(TheCU, Scope, Children);
587 // Early exit when we know the scope DIE is going to be null.
588 if (isLexicalScopeDIENull(Scope))
591 // We create children here when we know the scope DIE is not going to be
592 // null and the children will be added to the scope DIE.
593 createScopeChildrenDIE(TheCU, Scope, Children);
595 // There is no need to emit empty lexical block DIE.
596 std::pair<ImportedEntityMap::const_iterator,
597 ImportedEntityMap::const_iterator> Range =
598 std::equal_range(ScopesWithImportedEntities.begin(),
599 ScopesWithImportedEntities.end(),
600 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
602 if (Children.empty() && Range.first == Range.second)
604 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
605 assert(ScopeDIE && "Scope DIE should not be null.");
606 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
608 constructImportedEntityDIE(TheCU, i->second, *ScopeDIE);
612 for (auto &I : Children)
613 ScopeDIE->addChild(std::move(I));
618 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
619 if (!GenerateGnuPubSections)
622 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
625 // Create new DwarfCompileUnit for the given metadata node with tag
626 // DW_TAG_compile_unit.
627 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
628 StringRef FN = DIUnit.getFilename();
629 CompilationDir = DIUnit.getDirectory();
631 auto OwnedUnit = make_unique<DwarfCompileUnit>(
632 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
633 DwarfCompileUnit &NewCU = *OwnedUnit;
634 DIE &Die = NewCU.getUnitDie();
635 InfoHolder.addUnit(std::move(OwnedUnit));
637 // LTO with assembly output shares a single line table amongst multiple CUs.
638 // To avoid the compilation directory being ambiguous, let the line table
639 // explicitly describe the directory of all files, never relying on the
640 // compilation directory.
641 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
642 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
643 NewCU.getUniqueID(), CompilationDir);
645 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
646 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
647 DIUnit.getLanguage());
648 NewCU.addString(Die, dwarf::DW_AT_name, FN);
650 if (!useSplitDwarf()) {
651 NewCU.initStmtList(DwarfLineSectionSym);
653 // If we're using split dwarf the compilation dir is going to be in the
654 // skeleton CU and so we don't need to duplicate it here.
655 if (!CompilationDir.empty())
656 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
658 addGnuPubAttributes(NewCU, Die);
661 if (DIUnit.isOptimized())
662 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
664 StringRef Flags = DIUnit.getFlags();
666 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
668 if (unsigned RVer = DIUnit.getRunTimeVersion())
669 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
670 dwarf::DW_FORM_data1, RVer);
675 if (useSplitDwarf()) {
676 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
677 DwarfInfoDWOSectionSym);
678 NewCU.setSkeleton(constructSkeletonCU(NewCU));
680 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
681 DwarfInfoSectionSym);
683 CUMap.insert(std::make_pair(DIUnit, &NewCU));
684 CUDieMap.insert(std::make_pair(&Die, &NewCU));
688 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
690 DIImportedEntity Module(N);
691 assert(Module.Verify());
692 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
693 constructImportedEntityDIE(TheCU, Module, *D);
696 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
697 const MDNode *N, DIE &Context) {
698 DIImportedEntity Module(N);
699 assert(Module.Verify());
700 return constructImportedEntityDIE(TheCU, Module, Context);
703 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
704 const DIImportedEntity &Module,
706 assert(Module.Verify() &&
707 "Use one of the MDNode * overloads to handle invalid metadata");
708 DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), Context, Module);
710 DIDescriptor Entity = resolve(Module.getEntity());
711 if (Entity.isNameSpace())
712 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
713 else if (Entity.isSubprogram())
714 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
715 else if (Entity.isType())
716 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
718 EntityDie = TheCU.getDIE(Entity);
719 TheCU.addSourceLine(IMDie, Module.getLineNumber(),
720 Module.getContext().getFilename(),
721 Module.getContext().getDirectory());
722 TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
723 StringRef Name = Module.getName();
725 TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
728 // Emit all Dwarf sections that should come prior to the content. Create
729 // global DIEs and emit initial debug info sections. This is invoked by
730 // the target AsmPrinter.
731 void DwarfDebug::beginModule() {
732 if (DisableDebugInfoPrinting)
735 const Module *M = MMI->getModule();
737 FunctionDIs = makeSubprogramMap(*M);
739 // If module has named metadata anchors then use them, otherwise scan the
740 // module using debug info finder to collect debug info.
741 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
744 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
746 // Emit initial sections so we can reference labels later.
749 SingleCU = CU_Nodes->getNumOperands() == 1;
751 for (MDNode *N : CU_Nodes->operands()) {
752 DICompileUnit CUNode(N);
753 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
754 DIArray ImportedEntities = CUNode.getImportedEntities();
755 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
756 ScopesWithImportedEntities.push_back(std::make_pair(
757 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
758 ImportedEntities.getElement(i)));
759 std::sort(ScopesWithImportedEntities.begin(),
760 ScopesWithImportedEntities.end(), less_first());
761 DIArray GVs = CUNode.getGlobalVariables();
762 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
763 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
764 DIArray SPs = CUNode.getSubprograms();
765 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
766 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
767 DIArray EnumTypes = CUNode.getEnumTypes();
768 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
769 DIType Ty(EnumTypes.getElement(i));
770 // The enum 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 DIArray RetainedTypes = CUNode.getRetainedTypes();
776 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
777 DIType Ty(RetainedTypes.getElement(i));
778 // The retained types array by design contains pointers to
779 // MDNodes rather than DIRefs. Unique them here.
780 DIType UniqueTy(resolve(Ty.getRef()));
781 CU.getOrCreateTypeDIE(UniqueTy);
783 // Emit imported_modules last so that the relevant context is already
785 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
786 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
789 // Tell MMI that we have debug info.
790 MMI->setDebugInfoAvailability(true);
792 // Prime section data.
793 SectionMap[Asm->getObjFileLowering().getTextSection()];
796 void DwarfDebug::finishVariableDefinitions() {
797 for (const auto &Var : ConcreteVariables) {
798 DIE *VariableDie = Var->getDIE();
799 // FIXME: There shouldn't be any variables without DIEs.
802 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
803 // in the ConcreteVariables list, rather than looking it up again here.
804 // DIE::getUnit isn't simple - it walks parent pointers, etc.
805 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
807 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
808 if (AbsVar && AbsVar->getDIE()) {
809 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
812 Unit->applyVariableAttributes(*Var, *VariableDie);
816 void DwarfDebug::finishSubprogramDefinitions() {
817 const Module *M = MMI->getModule();
819 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
820 for (MDNode *N : CU_Nodes->operands()) {
821 DICompileUnit TheCU(N);
822 // Construct subprogram DIE and add variables DIEs.
823 DwarfCompileUnit *SPCU =
824 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
825 DIArray Subprograms = TheCU.getSubprograms();
826 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
827 DISubprogram SP(Subprograms.getElement(i));
828 // Perhaps the subprogram is in another CU (such as due to comdat
829 // folding, etc), in which case ignore it here.
830 if (SPMap[SP] != SPCU)
832 DIE *D = SPCU->getDIE(SP);
833 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
835 // If this subprogram has an abstract definition, reference that
836 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
839 // Lazily construct the subprogram if we didn't see either concrete or
840 // inlined versions during codegen.
841 D = SPCU->getOrCreateSubprogramDIE(SP);
842 // And attach the attributes
843 SPCU->applySubprogramAttributesToDefinition(SP, *D);
850 // Collect info for variables that were optimized out.
851 void DwarfDebug::collectDeadVariables() {
852 const Module *M = MMI->getModule();
854 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
855 for (MDNode *N : CU_Nodes->operands()) {
856 DICompileUnit TheCU(N);
857 // Construct subprogram DIE and add variables DIEs.
858 DwarfCompileUnit *SPCU =
859 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
860 assert(SPCU && "Unable to find Compile Unit!");
861 DIArray Subprograms = TheCU.getSubprograms();
862 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
863 DISubprogram SP(Subprograms.getElement(i));
864 if (ProcessedSPNodes.count(SP) != 0)
866 assert(SP.isSubprogram() &&
867 "CU's subprogram list contains a non-subprogram");
868 assert(SP.isDefinition() &&
869 "CU's subprogram list contains a subprogram declaration");
870 DIArray Variables = SP.getVariables();
871 if (Variables.getNumElements() == 0)
874 DIE *SPDIE = AbstractSPDies.lookup(SP);
876 SPDIE = SPCU->getDIE(SP);
878 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
879 DIVariable DV(Variables.getElement(vi));
880 assert(DV.isVariable());
881 DbgVariable NewVar(DV, this);
882 auto VariableDie = SPCU->constructVariableDIE(NewVar);
883 SPCU->applyVariableAttributes(NewVar, *VariableDie);
884 SPDIE->addChild(std::move(VariableDie));
891 void DwarfDebug::finalizeModuleInfo() {
892 finishSubprogramDefinitions();
894 finishVariableDefinitions();
896 // Collect info for variables that were optimized out.
897 collectDeadVariables();
899 // Handle anything that needs to be done on a per-unit basis after
900 // all other generation.
901 for (const auto &TheU : getUnits()) {
902 // Emit DW_AT_containing_type attribute to connect types with their
903 // vtable holding type.
904 TheU->constructContainingTypeDIEs();
906 // Add CU specific attributes if we need to add any.
907 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
908 // If we're splitting the dwarf out now that we've got the entire
909 // CU then add the dwo id to it.
910 DwarfCompileUnit *SkCU =
911 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
912 if (useSplitDwarf()) {
913 // Emit a unique identifier for this CU.
914 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
915 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
916 dwarf::DW_FORM_data8, ID);
917 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
918 dwarf::DW_FORM_data8, ID);
920 // We don't keep track of which addresses are used in which CU so this
921 // is a bit pessimistic under LTO.
922 if (!AddrPool.isEmpty())
923 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
924 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
925 DwarfAddrSectionSym);
926 if (!TheU->getRangeLists().empty())
927 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
928 dwarf::DW_AT_GNU_ranges_base,
929 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
932 // If we have code split among multiple sections or non-contiguous
933 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
934 // remain in the .o file, otherwise add a DW_AT_low_pc.
935 // FIXME: We should use ranges allow reordering of code ala
936 // .subsections_via_symbols in mach-o. This would mean turning on
937 // ranges for all subprogram DIEs for mach-o.
938 DwarfCompileUnit &U =
939 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
940 unsigned NumRanges = TheU->getRanges().size();
943 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
944 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
945 DwarfDebugRangeSectionSym);
947 // A DW_AT_low_pc attribute may also be specified in combination with
948 // DW_AT_ranges to specify the default base address for use in
949 // location lists (see Section 2.6.2) and range lists (see Section
951 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
954 RangeSpan &Range = TheU->getRanges().back();
955 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
957 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
964 // Compute DIE offsets and sizes.
965 InfoHolder.computeSizeAndOffsets();
967 SkeletonHolder.computeSizeAndOffsets();
970 void DwarfDebug::endSections() {
971 // Filter labels by section.
972 for (const SymbolCU &SCU : ArangeLabels) {
973 if (SCU.Sym->isInSection()) {
974 // Make a note of this symbol and it's section.
975 const MCSection *Section = &SCU.Sym->getSection();
976 if (!Section->getKind().isMetadata())
977 SectionMap[Section].push_back(SCU);
979 // Some symbols (e.g. common/bss on mach-o) can have no section but still
980 // appear in the output. This sucks as we rely on sections to build
981 // arange spans. We can do it without, but it's icky.
982 SectionMap[nullptr].push_back(SCU);
986 // Build a list of sections used.
987 std::vector<const MCSection *> Sections;
988 for (const auto &it : SectionMap) {
989 const MCSection *Section = it.first;
990 Sections.push_back(Section);
993 // Sort the sections into order.
994 // This is only done to ensure consistent output order across different runs.
995 std::sort(Sections.begin(), Sections.end(), SectionSort);
997 // Add terminating symbols for each section.
998 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
999 const MCSection *Section = Sections[ID];
1000 MCSymbol *Sym = nullptr;
1003 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1004 // if we know the section name up-front. For user-created sections, the
1005 // resulting label may not be valid to use as a label. (section names can
1006 // use a greater set of characters on some systems)
1007 Sym = Asm->GetTempSymbol("debug_end", ID);
1008 Asm->OutStreamer.SwitchSection(Section);
1009 Asm->OutStreamer.EmitLabel(Sym);
1012 // Insert a final terminator.
1013 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1017 // Emit all Dwarf sections that should come after the content.
1018 void DwarfDebug::endModule() {
1019 assert(CurFn == nullptr);
1020 assert(CurMI == nullptr);
1025 // End any existing sections.
1026 // TODO: Does this need to happen?
1029 // Finalize the debug info for the module.
1030 finalizeModuleInfo();
1034 // Emit all the DIEs into a debug info section.
1037 // Corresponding abbreviations into a abbrev section.
1038 emitAbbreviations();
1040 // Emit info into a debug aranges section.
1041 if (GenerateARangeSection)
1044 // Emit info into a debug ranges section.
1047 if (useSplitDwarf()) {
1050 emitDebugAbbrevDWO();
1053 // Emit DWO addresses.
1054 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1056 // Emit info into a debug loc section.
1059 // Emit info into the dwarf accelerator table sections.
1060 if (useDwarfAccelTables()) {
1063 emitAccelNamespaces();
1067 // Emit the pubnames and pubtypes sections if requested.
1068 if (HasDwarfPubSections) {
1069 emitDebugPubNames(GenerateGnuPubSections);
1070 emitDebugPubTypes(GenerateGnuPubSections);
1075 AbstractVariables.clear();
1077 // Reset these for the next Module if we have one.
1081 // Find abstract variable, if any, associated with Var.
1082 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1083 DIVariable &Cleansed) {
1084 LLVMContext &Ctx = DV->getContext();
1085 // More then one inlined variable corresponds to one abstract variable.
1086 // FIXME: This duplication of variables when inlining should probably be
1087 // removed. It's done to allow each DIVariable to describe its location
1088 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1089 // make it accurate then remove this duplication/cleansing stuff.
1090 Cleansed = cleanseInlinedVariable(DV, Ctx);
1091 auto I = AbstractVariables.find(Cleansed);
1092 if (I != AbstractVariables.end())
1093 return I->second.get();
1097 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1098 DIVariable Cleansed;
1099 return getExistingAbstractVariable(DV, Cleansed);
1102 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1103 LexicalScope *Scope) {
1104 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1105 addScopeVariable(Scope, AbsDbgVariable.get());
1106 AbstractVariables[Var] = std::move(AbsDbgVariable);
1109 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1110 const MDNode *ScopeNode) {
1111 DIVariable Cleansed = DV;
1112 if (getExistingAbstractVariable(DV, Cleansed))
1115 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1119 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1120 const MDNode *ScopeNode) {
1121 DIVariable Cleansed = DV;
1122 if (getExistingAbstractVariable(DV, Cleansed))
1125 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1126 createAbstractVariable(Cleansed, Scope);
1129 // If Var is a current function argument then add it to CurrentFnArguments list.
1130 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1131 if (!LScopes.isCurrentFunctionScope(Scope))
1133 DIVariable DV = Var->getVariable();
1134 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1136 unsigned ArgNo = DV.getArgNumber();
1140 size_t Size = CurrentFnArguments.size();
1142 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1143 // llvm::Function argument size is not good indicator of how many
1144 // arguments does the function have at source level.
1146 CurrentFnArguments.resize(ArgNo * 2);
1147 CurrentFnArguments[ArgNo - 1] = Var;
1151 // Collect variable information from side table maintained by MMI.
1152 void DwarfDebug::collectVariableInfoFromMMITable(
1153 SmallPtrSet<const MDNode *, 16> &Processed) {
1154 for (const auto &VI : MMI->getVariableDbgInfo()) {
1157 Processed.insert(VI.Var);
1158 DIVariable DV(VI.Var);
1159 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1161 // If variable scope is not found then skip this variable.
1165 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1166 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1167 DbgVariable *RegVar = ConcreteVariables.back().get();
1168 RegVar->setFrameIndex(VI.Slot);
1169 addScopeVariable(Scope, RegVar);
1173 // Get .debug_loc entry for the instruction range starting at MI.
1174 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1175 const MDNode *Var = MI->getDebugVariable();
1177 assert(MI->getNumOperands() == 3);
1178 if (MI->getOperand(0).isReg()) {
1179 MachineLocation MLoc;
1180 // If the second operand is an immediate, this is a
1181 // register-indirect address.
1182 if (!MI->getOperand(1).isImm())
1183 MLoc.set(MI->getOperand(0).getReg());
1185 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1186 return DebugLocEntry::Value(Var, MLoc);
1188 if (MI->getOperand(0).isImm())
1189 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1190 if (MI->getOperand(0).isFPImm())
1191 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1192 if (MI->getOperand(0).isCImm())
1193 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1195 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1198 /// Determine whether two variable pieces overlap.
1199 static bool piecesOverlap(DIVariable P1, DIVariable P2) {
1200 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1202 unsigned l1 = P1.getPieceOffset();
1203 unsigned l2 = P2.getPieceOffset();
1204 unsigned r1 = l1 + P1.getPieceSize();
1205 unsigned r2 = l2 + P2.getPieceSize();
1206 // True where [l1,r1[ and [r1,r2[ overlap.
1207 return (l1 < r2) && (l2 < r1);
1210 /// Build the location list for all DBG_VALUEs in the function that
1211 /// describe the same variable. If the ranges of several independent
1212 /// pieces of the same variable overlap partially, split them up and
1213 /// combine the ranges. The resulting DebugLocEntries are will have
1214 /// strict monotonically increasing begin addresses and will never
1219 // Ranges History [var, loc, piece ofs size]
1220 // 0 | [x, (reg0, piece 0, 32)]
1221 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1223 // 3 | [clobber reg0]
1224 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1228 // [0-1] [x, (reg0, piece 0, 32)]
1229 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1230 // [3-4] [x, (reg1, piece 32, 32)]
1231 // [4- ] [x, (mem, piece 0, 64)]
1233 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1234 const DbgValueHistoryMap::InstrRanges &Ranges) {
1235 typedef std::pair<DIVariable, DebugLocEntry::Value> Range;
1236 SmallVector<Range, 4> OpenRanges;
1238 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1239 const MachineInstr *Begin = I->first;
1240 const MachineInstr *End = I->second;
1241 assert(Begin->isDebugValue() && "Invalid History entry");
1243 // Check if a variable is inaccessible in this range.
1244 if (!Begin->isDebugValue() ||
1245 (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1246 !Begin->getOperand(0).getReg())) {
1251 // If this piece overlaps with any open ranges, truncate them.
1252 DIVariable DIVar = Begin->getDebugVariable();
1253 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(), [&](Range R){
1254 return piecesOverlap(DIVar, R.first);
1256 OpenRanges.erase(Last, OpenRanges.end());
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 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1272 auto Value = getDebugLocValue(Begin);
1273 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1274 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc)) {
1275 // Add all values from still valid non-overlapping pieces.
1276 for (auto Range : OpenRanges)
1277 Loc.addValue(Range.second);
1278 DebugLoc.push_back(std::move(Loc));
1280 // Add this value to the list of open ranges.
1281 if (DIVar.isVariablePiece())
1282 OpenRanges.push_back(std::make_pair(DIVar, Value));
1284 DEBUG(dbgs() << "Values:\n";
1285 for (auto Value : DebugLoc.back().getValues())
1286 Value.getVariable()->dump();
1287 dbgs() << "-----\n");
1292 // Find variables for each lexical scope.
1294 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1295 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1296 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1298 // Grab the variable info that was squirreled away in the MMI side-table.
1299 collectVariableInfoFromMMITable(Processed);
1301 for (const auto &I : DbgValues) {
1302 DIVariable DV(I.first);
1303 if (Processed.count(DV))
1306 // Instruction ranges, specifying where DV is accessible.
1307 const auto &Ranges = I.second;
1311 LexicalScope *Scope = nullptr;
1312 if (MDNode *IA = DV.getInlinedAt()) {
1313 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1314 Scope = LScopes.findInlinedScope(DebugLoc::get(
1315 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1317 Scope = LScopes.findLexicalScope(DV.getContext());
1318 // If variable scope is not found then skip this variable.
1322 Processed.insert(getEntireVariable(DV));
1323 const MachineInstr *MInsn = Ranges.front().first;
1324 assert(MInsn->isDebugValue() && "History must begin with debug value");
1325 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1326 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1327 DbgVariable *RegVar = ConcreteVariables.back().get();
1328 addScopeVariable(Scope, RegVar);
1330 // Check if the first DBG_VALUE is valid for the rest of the function.
1331 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1334 // Handle multiple DBG_VALUE instructions describing one variable.
1335 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1337 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1338 DebugLocList &LocList = DotDebugLocEntries.back();
1341 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1343 // Build the location list for this variable.
1344 buildLocationList(LocList.List, Ranges);
1347 // Collect info for variables that were optimized out.
1348 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1349 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1350 DIVariable DV(Variables.getElement(i));
1351 assert(DV.isVariable());
1352 if (!Processed.insert(DV))
1354 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1355 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1356 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1357 addScopeVariable(Scope, ConcreteVariables.back().get());
1362 // Return Label preceding the instruction.
1363 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1364 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1365 assert(Label && "Didn't insert label before instruction");
1369 // Return Label immediately following the instruction.
1370 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1371 return LabelsAfterInsn.lookup(MI);
1374 // Process beginning of an instruction.
1375 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1376 assert(CurMI == nullptr);
1378 // Check if source location changes, but ignore DBG_VALUE locations.
1379 if (!MI->isDebugValue()) {
1380 DebugLoc DL = MI->getDebugLoc();
1381 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1384 if (DL == PrologEndLoc) {
1385 Flags |= DWARF2_FLAG_PROLOGUE_END;
1386 PrologEndLoc = DebugLoc();
1388 if (PrologEndLoc.isUnknown())
1389 Flags |= DWARF2_FLAG_IS_STMT;
1391 if (!DL.isUnknown()) {
1392 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1393 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1395 recordSourceLine(0, 0, nullptr, 0);
1399 // Insert labels where requested.
1400 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1401 LabelsBeforeInsn.find(MI);
1404 if (I == LabelsBeforeInsn.end())
1407 // Label already assigned.
1412 PrevLabel = MMI->getContext().CreateTempSymbol();
1413 Asm->OutStreamer.EmitLabel(PrevLabel);
1415 I->second = PrevLabel;
1418 // Process end of an instruction.
1419 void DwarfDebug::endInstruction() {
1420 assert(CurMI != nullptr);
1421 // Don't create a new label after DBG_VALUE instructions.
1422 // They don't generate code.
1423 if (!CurMI->isDebugValue())
1424 PrevLabel = nullptr;
1426 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1427 LabelsAfterInsn.find(CurMI);
1431 if (I == LabelsAfterInsn.end())
1434 // Label already assigned.
1438 // We need a label after this instruction.
1440 PrevLabel = MMI->getContext().CreateTempSymbol();
1441 Asm->OutStreamer.EmitLabel(PrevLabel);
1443 I->second = PrevLabel;
1446 // Each LexicalScope has first instruction and last instruction to mark
1447 // beginning and end of a scope respectively. Create an inverse map that list
1448 // scopes starts (and ends) with an instruction. One instruction may start (or
1449 // end) multiple scopes. Ignore scopes that are not reachable.
1450 void DwarfDebug::identifyScopeMarkers() {
1451 SmallVector<LexicalScope *, 4> WorkList;
1452 WorkList.push_back(LScopes.getCurrentFunctionScope());
1453 while (!WorkList.empty()) {
1454 LexicalScope *S = WorkList.pop_back_val();
1456 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1457 if (!Children.empty())
1458 WorkList.append(Children.begin(), Children.end());
1460 if (S->isAbstractScope())
1463 for (const InsnRange &R : S->getRanges()) {
1464 assert(R.first && "InsnRange does not have first instruction!");
1465 assert(R.second && "InsnRange does not have second instruction!");
1466 requestLabelBeforeInsn(R.first);
1467 requestLabelAfterInsn(R.second);
1472 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1473 // First known non-DBG_VALUE and non-frame setup location marks
1474 // the beginning of the function body.
1475 for (const auto &MBB : *MF)
1476 for (const auto &MI : MBB)
1477 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1478 !MI.getDebugLoc().isUnknown())
1479 return MI.getDebugLoc();
1483 // Gather pre-function debug information. Assumes being called immediately
1484 // after the function entry point has been emitted.
1485 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1488 // If there's no debug info for the function we're not going to do anything.
1489 if (!MMI->hasDebugInfo())
1492 auto DI = FunctionDIs.find(MF->getFunction());
1493 if (DI == FunctionDIs.end())
1496 // Grab the lexical scopes for the function, if we don't have any of those
1497 // then we're not going to be able to do anything.
1498 LScopes.initialize(*MF);
1499 if (LScopes.empty())
1502 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1504 // Make sure that each lexical scope will have a begin/end label.
1505 identifyScopeMarkers();
1507 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1508 // belongs to so that we add to the correct per-cu line table in the
1510 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1511 // FnScope->getScopeNode() and DI->second should represent the same function,
1512 // though they may not be the same MDNode due to inline functions merged in
1513 // LTO where the debug info metadata still differs (either due to distinct
1514 // written differences - two versions of a linkonce_odr function
1515 // written/copied into two separate files, or some sub-optimal metadata that
1516 // isn't structurally identical (see: file path/name info from clang, which
1517 // includes the directory of the cpp file being built, even when the file name
1518 // is absolute (such as an <> lookup header)))
1519 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1520 assert(TheCU && "Unable to find compile unit!");
1521 if (Asm->OutStreamer.hasRawTextSupport())
1522 // Use a single line table if we are generating assembly.
1523 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1525 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1527 // Emit a label for the function so that we have a beginning address.
1528 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1529 // Assumes in correct section after the entry point.
1530 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1532 // Calculate history for local variables.
1533 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1536 // Request labels for the full history.
1537 for (const auto &I : DbgValues) {
1538 const auto &Ranges = I.second;
1542 // The first mention of a function argument gets the FunctionBeginSym
1543 // label, so arguments are visible when breaking at function entry.
1544 DIVariable DV(Ranges.front().first->getDebugVariable());
1545 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1546 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1547 if (!DV.isVariablePiece())
1548 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1550 // Mark all non-overlapping initial pieces.
1551 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1552 DIVariable Piece = I->first->getDebugVariable();
1553 if (std::all_of(Ranges.begin(), I,
1554 [&](DbgValueHistoryMap::InstrRange Pred){
1555 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1557 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1564 for (const auto &Range : Ranges) {
1565 requestLabelBeforeInsn(Range.first);
1567 requestLabelAfterInsn(Range.second);
1571 PrevInstLoc = DebugLoc();
1572 PrevLabel = FunctionBeginSym;
1574 // Record beginning of function.
1575 PrologEndLoc = findPrologueEndLoc(MF);
1576 if (!PrologEndLoc.isUnknown()) {
1577 DebugLoc FnStartDL =
1578 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1580 FnStartDL.getLine(), FnStartDL.getCol(),
1581 FnStartDL.getScope(MF->getFunction()->getContext()),
1582 // We'd like to list the prologue as "not statements" but GDB behaves
1583 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1584 DWARF2_FLAG_IS_STMT);
1588 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1589 if (addCurrentFnArgument(Var, LS))
1591 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1592 DIVariable DV = Var->getVariable();
1593 // Variables with positive arg numbers are parameters.
1594 if (unsigned ArgNum = DV.getArgNumber()) {
1595 // Keep all parameters in order at the start of the variable list to ensure
1596 // function types are correct (no out-of-order parameters)
1598 // This could be improved by only doing it for optimized builds (unoptimized
1599 // builds have the right order to begin with), searching from the back (this
1600 // would catch the unoptimized case quickly), or doing a binary search
1601 // rather than linear search.
1602 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1603 while (I != Vars.end()) {
1604 unsigned CurNum = (*I)->getVariable().getArgNumber();
1605 // A local (non-parameter) variable has been found, insert immediately
1609 // A later indexed parameter has been found, insert immediately before it.
1610 if (CurNum > ArgNum)
1614 Vars.insert(I, Var);
1618 Vars.push_back(Var);
1621 // Gather and emit post-function debug information.
1622 void DwarfDebug::endFunction(const MachineFunction *MF) {
1623 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1624 // though the beginFunction may not be called at all.
1625 // We should handle both cases.
1629 assert(CurFn == MF);
1630 assert(CurFn != nullptr);
1632 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1633 !FunctionDIs.count(MF->getFunction())) {
1634 // If we don't have a lexical scope for this function then there will
1635 // be a hole in the range information. Keep note of this by setting the
1636 // previously used section to nullptr.
1637 PrevSection = nullptr;
1643 // Define end label for subprogram.
1644 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1645 // Assumes in correct section after the entry point.
1646 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1648 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1649 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1651 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1652 collectVariableInfo(ProcessedVars);
1654 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1655 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1657 // Construct abstract scopes.
1658 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1659 DISubprogram SP(AScope->getScopeNode());
1660 assert(SP.isSubprogram());
1661 // Collect info for variables that were optimized out.
1662 DIArray Variables = SP.getVariables();
1663 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1664 DIVariable DV(Variables.getElement(i));
1665 assert(DV && DV.isVariable());
1666 if (!ProcessedVars.insert(DV))
1668 ensureAbstractVariableIsCreated(DV, DV.getContext());
1670 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1673 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1674 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1675 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1677 // Add the range of this function to the list of ranges for the CU.
1678 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1679 TheCU.addRange(std::move(Span));
1680 PrevSection = Asm->getCurrentSection();
1684 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1685 // DbgVariables except those that are also in AbstractVariables (since they
1686 // can be used cross-function)
1687 ScopeVariables.clear();
1688 CurrentFnArguments.clear();
1690 LabelsBeforeInsn.clear();
1691 LabelsAfterInsn.clear();
1692 PrevLabel = nullptr;
1696 // Register a source line with debug info. Returns the unique label that was
1697 // emitted and which provides correspondence to the source line list.
1698 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1703 unsigned Discriminator = 0;
1704 if (DIScope Scope = DIScope(S)) {
1705 assert(Scope.isScope());
1706 Fn = Scope.getFilename();
1707 Dir = Scope.getDirectory();
1708 if (Scope.isLexicalBlock())
1709 Discriminator = DILexicalBlock(S).getDiscriminator();
1711 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1712 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1713 .getOrCreateSourceID(Fn, Dir);
1715 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1719 //===----------------------------------------------------------------------===//
1721 //===----------------------------------------------------------------------===//
1723 // Emit initial Dwarf sections with a label at the start of each one.
1724 void DwarfDebug::emitSectionLabels() {
1725 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1727 // Dwarf sections base addresses.
1728 DwarfInfoSectionSym =
1729 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1730 if (useSplitDwarf()) {
1731 DwarfInfoDWOSectionSym =
1732 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1733 DwarfTypesDWOSectionSym =
1734 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1736 DwarfAbbrevSectionSym =
1737 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1738 if (useSplitDwarf())
1739 DwarfAbbrevDWOSectionSym = emitSectionSym(
1740 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1741 if (GenerateARangeSection)
1742 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1744 DwarfLineSectionSym =
1745 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1746 if (GenerateGnuPubSections) {
1747 DwarfGnuPubNamesSectionSym =
1748 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1749 DwarfGnuPubTypesSectionSym =
1750 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1751 } else if (HasDwarfPubSections) {
1752 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1753 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1756 DwarfStrSectionSym =
1757 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1758 if (useSplitDwarf()) {
1759 DwarfStrDWOSectionSym =
1760 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1761 DwarfAddrSectionSym =
1762 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1763 DwarfDebugLocSectionSym =
1764 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1766 DwarfDebugLocSectionSym =
1767 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1768 DwarfDebugRangeSectionSym =
1769 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1772 // Recursively emits a debug information entry.
1773 void DwarfDebug::emitDIE(DIE &Die) {
1774 // Get the abbreviation for this DIE.
1775 const DIEAbbrev &Abbrev = Die.getAbbrev();
1777 // Emit the code (index) for the abbreviation.
1778 if (Asm->isVerbose())
1779 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1780 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1781 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1782 dwarf::TagString(Abbrev.getTag()));
1783 Asm->EmitULEB128(Abbrev.getNumber());
1785 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1786 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1788 // Emit the DIE attribute values.
1789 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1790 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1791 dwarf::Form Form = AbbrevData[i].getForm();
1792 assert(Form && "Too many attributes for DIE (check abbreviation)");
1794 if (Asm->isVerbose()) {
1795 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1796 if (Attr == dwarf::DW_AT_accessibility)
1797 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1798 cast<DIEInteger>(Values[i])->getValue()));
1801 // Emit an attribute using the defined form.
1802 Values[i]->EmitValue(Asm, Form);
1805 // Emit the DIE children if any.
1806 if (Abbrev.hasChildren()) {
1807 for (auto &Child : Die.getChildren())
1810 Asm->OutStreamer.AddComment("End Of Children Mark");
1815 // Emit the debug info section.
1816 void DwarfDebug::emitDebugInfo() {
1817 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1819 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1822 // Emit the abbreviation section.
1823 void DwarfDebug::emitAbbreviations() {
1824 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1826 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1829 // Emit the last address of the section and the end of the line matrix.
1830 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1831 // Define last address of section.
1832 Asm->OutStreamer.AddComment("Extended Op");
1835 Asm->OutStreamer.AddComment("Op size");
1836 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1837 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1838 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1840 Asm->OutStreamer.AddComment("Section end label");
1842 Asm->OutStreamer.EmitSymbolValue(
1843 Asm->GetTempSymbol("section_end", SectionEnd),
1844 Asm->getDataLayout().getPointerSize());
1846 // Mark end of matrix.
1847 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1853 // Emit visible names into a hashed accelerator table section.
1854 void DwarfDebug::emitAccelNames() {
1855 AccelNames.FinalizeTable(Asm, "Names");
1856 Asm->OutStreamer.SwitchSection(
1857 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1858 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1859 Asm->OutStreamer.EmitLabel(SectionBegin);
1861 // Emit the full data.
1862 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1865 // Emit objective C classes and categories into a hashed accelerator table
1867 void DwarfDebug::emitAccelObjC() {
1868 AccelObjC.FinalizeTable(Asm, "ObjC");
1869 Asm->OutStreamer.SwitchSection(
1870 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1871 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1872 Asm->OutStreamer.EmitLabel(SectionBegin);
1874 // Emit the full data.
1875 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1878 // Emit namespace dies into a hashed accelerator table.
1879 void DwarfDebug::emitAccelNamespaces() {
1880 AccelNamespace.FinalizeTable(Asm, "namespac");
1881 Asm->OutStreamer.SwitchSection(
1882 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1883 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1884 Asm->OutStreamer.EmitLabel(SectionBegin);
1886 // Emit the full data.
1887 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1890 // Emit type dies into a hashed accelerator table.
1891 void DwarfDebug::emitAccelTypes() {
1893 AccelTypes.FinalizeTable(Asm, "types");
1894 Asm->OutStreamer.SwitchSection(
1895 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1896 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1897 Asm->OutStreamer.EmitLabel(SectionBegin);
1899 // Emit the full data.
1900 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1903 // Public name handling.
1904 // The format for the various pubnames:
1906 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1907 // for the DIE that is named.
1909 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1910 // into the CU and the index value is computed according to the type of value
1911 // for the DIE that is named.
1913 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1914 // it's the offset within the debug_info/debug_types dwo section, however, the
1915 // reference in the pubname header doesn't change.
1917 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1918 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1920 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1922 // We could have a specification DIE that has our most of our knowledge,
1923 // look for that now.
1924 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1926 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1927 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1928 Linkage = dwarf::GIEL_EXTERNAL;
1929 } else if (Die->findAttribute(dwarf::DW_AT_external))
1930 Linkage = dwarf::GIEL_EXTERNAL;
1932 switch (Die->getTag()) {
1933 case dwarf::DW_TAG_class_type:
1934 case dwarf::DW_TAG_structure_type:
1935 case dwarf::DW_TAG_union_type:
1936 case dwarf::DW_TAG_enumeration_type:
1937 return dwarf::PubIndexEntryDescriptor(
1938 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1939 ? dwarf::GIEL_STATIC
1940 : dwarf::GIEL_EXTERNAL);
1941 case dwarf::DW_TAG_typedef:
1942 case dwarf::DW_TAG_base_type:
1943 case dwarf::DW_TAG_subrange_type:
1944 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1945 case dwarf::DW_TAG_namespace:
1946 return dwarf::GIEK_TYPE;
1947 case dwarf::DW_TAG_subprogram:
1948 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1949 case dwarf::DW_TAG_constant:
1950 case dwarf::DW_TAG_variable:
1951 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1952 case dwarf::DW_TAG_enumerator:
1953 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1954 dwarf::GIEL_STATIC);
1956 return dwarf::GIEK_NONE;
1960 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1962 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1963 const MCSection *PSec =
1964 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1965 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1967 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1970 void DwarfDebug::emitDebugPubSection(
1971 bool GnuStyle, const MCSection *PSec, StringRef Name,
1972 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1973 for (const auto &NU : CUMap) {
1974 DwarfCompileUnit *TheU = NU.second;
1976 const auto &Globals = (TheU->*Accessor)();
1978 if (Globals.empty())
1981 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1983 unsigned ID = TheU->getUniqueID();
1985 // Start the dwarf pubnames section.
1986 Asm->OutStreamer.SwitchSection(PSec);
1989 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1990 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
1991 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
1992 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1994 Asm->OutStreamer.EmitLabel(BeginLabel);
1996 Asm->OutStreamer.AddComment("DWARF Version");
1997 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1999 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2000 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2002 Asm->OutStreamer.AddComment("Compilation Unit Length");
2003 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2005 // Emit the pubnames for this compilation unit.
2006 for (const auto &GI : Globals) {
2007 const char *Name = GI.getKeyData();
2008 const DIE *Entity = GI.second;
2010 Asm->OutStreamer.AddComment("DIE offset");
2011 Asm->EmitInt32(Entity->getOffset());
2014 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2015 Asm->OutStreamer.AddComment(
2016 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2017 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2018 Asm->EmitInt8(Desc.toBits());
2021 Asm->OutStreamer.AddComment("External Name");
2022 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2025 Asm->OutStreamer.AddComment("End Mark");
2027 Asm->OutStreamer.EmitLabel(EndLabel);
2031 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2032 const MCSection *PSec =
2033 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2034 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2036 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2039 // Emit visible names into a debug str section.
2040 void DwarfDebug::emitDebugStr() {
2041 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2042 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2045 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2046 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2047 const DITypeIdentifierMap &Map,
2048 ArrayRef<DebugLocEntry::Value> Values) {
2049 typedef DebugLocEntry::Value Piece;
2050 SmallVector<Piece, 4> Pieces(Values.begin(), Values.end());
2051 assert(std::all_of(Pieces.begin(), Pieces.end(), [](Piece &P) {
2052 return DIVariable(P.getVariable()).isVariablePiece();
2053 }) && "all values are expected to be pieces");
2055 // Sort the pieces so they can be emitted using DW_OP_piece.
2056 std::sort(Pieces.begin(), Pieces.end(), [](const Piece &A, const Piece &B) {
2057 DIVariable VarA(A.getVariable());
2058 DIVariable VarB(B.getVariable());
2059 return VarA.getPieceOffset() < VarB.getPieceOffset();
2061 // Remove any duplicate entries by dropping all but the first.
2062 Pieces.erase(std::unique(Pieces.begin(), Pieces.end(),
2063 [] (const Piece &A,const Piece &B){
2064 return A.getVariable() == B.getVariable();
2067 unsigned Offset = 0;
2068 for (auto Piece : Pieces) {
2069 DIVariable Var(Piece.getVariable());
2070 unsigned PieceOffset = Var.getPieceOffset();
2071 unsigned PieceSize = Var.getPieceSize();
2072 assert(Offset <= PieceOffset && "overlapping pieces in DebugLocEntry");
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 DIVariable DV(Value.getVariable());
2106 if (DV.isVariablePiece())
2107 // Emit all pieces that belong to the same variable and range.
2108 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2110 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2111 emitDebugLocValue(Streamer, Value);
2114 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2115 const DebugLocEntry::Value &Value) {
2116 DIVariable DV(Value.getVariable());
2118 if (Value.isInt()) {
2119 DIBasicType BTy(resolve(DV.getType()));
2120 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2121 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2122 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2123 Streamer.EmitSLEB128(Value.getInt());
2125 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2126 Streamer.EmitULEB128(Value.getInt());
2128 } else if (Value.isLocation()) {
2129 MachineLocation Loc = Value.getLoc();
2130 if (!DV.hasComplexAddress())
2132 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2134 // Complex address entry.
2135 unsigned N = DV.getNumAddrElements();
2137 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2138 if (Loc.getOffset()) {
2140 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2141 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2142 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2143 Streamer.EmitSLEB128(DV.getAddrElement(1));
2145 // If first address element is OpPlus then emit
2146 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2147 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2148 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2152 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2155 // Emit remaining complex address elements.
2156 for (; i < N; ++i) {
2157 uint64_t Element = DV.getAddrElement(i);
2158 if (Element == DIBuilder::OpPlus) {
2159 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2160 Streamer.EmitULEB128(DV.getAddrElement(++i));
2161 } else if (Element == DIBuilder::OpDeref) {
2163 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2164 } else if (Element == DIBuilder::OpPiece) {
2166 // handled in emitDebugLocEntry.
2168 llvm_unreachable("unknown Opcode found in complex address");
2172 // else ... ignore constant fp. There is not any good way to
2173 // to represent them here in dwarf.
2177 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2178 Asm->OutStreamer.AddComment("Loc expr size");
2179 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2180 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2181 Asm->EmitLabelDifference(end, begin, 2);
2182 Asm->OutStreamer.EmitLabel(begin);
2184 APByteStreamer Streamer(*Asm);
2185 emitDebugLocEntry(Streamer, Entry);
2187 Asm->OutStreamer.EmitLabel(end);
2190 // Emit locations into the debug loc section.
2191 void DwarfDebug::emitDebugLoc() {
2192 // Start the dwarf loc section.
2193 Asm->OutStreamer.SwitchSection(
2194 Asm->getObjFileLowering().getDwarfLocSection());
2195 unsigned char Size = Asm->getDataLayout().getPointerSize();
2196 for (const auto &DebugLoc : DotDebugLocEntries) {
2197 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2198 const DwarfCompileUnit *CU = DebugLoc.CU;
2199 assert(!CU->getRanges().empty());
2200 for (const auto &Entry : DebugLoc.List) {
2201 // Set up the range. This range is relative to the entry point of the
2202 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2203 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2204 if (CU->getRanges().size() == 1) {
2205 // Grab the begin symbol from the first range as our base.
2206 const MCSymbol *Base = CU->getRanges()[0].getStart();
2207 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2208 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2210 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2211 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2214 emitDebugLocEntryLocation(Entry);
2216 Asm->OutStreamer.EmitIntValue(0, Size);
2217 Asm->OutStreamer.EmitIntValue(0, Size);
2221 void DwarfDebug::emitDebugLocDWO() {
2222 Asm->OutStreamer.SwitchSection(
2223 Asm->getObjFileLowering().getDwarfLocDWOSection());
2224 for (const auto &DebugLoc : DotDebugLocEntries) {
2225 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2226 for (const auto &Entry : DebugLoc.List) {
2227 // Just always use start_length for now - at least that's one address
2228 // rather than two. We could get fancier and try to, say, reuse an
2229 // address we know we've emitted elsewhere (the start of the function?
2230 // The start of the CU or CU subrange that encloses this range?)
2231 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2232 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2233 Asm->EmitULEB128(idx);
2234 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2236 emitDebugLocEntryLocation(Entry);
2238 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2243 const MCSymbol *Start, *End;
2246 // Emit a debug aranges section, containing a CU lookup for any
2247 // address we can tie back to a CU.
2248 void DwarfDebug::emitDebugARanges() {
2249 // Start the dwarf aranges section.
2250 Asm->OutStreamer.SwitchSection(
2251 Asm->getObjFileLowering().getDwarfARangesSection());
2253 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2257 // Build a list of sections used.
2258 std::vector<const MCSection *> Sections;
2259 for (const auto &it : SectionMap) {
2260 const MCSection *Section = it.first;
2261 Sections.push_back(Section);
2264 // Sort the sections into order.
2265 // This is only done to ensure consistent output order across different runs.
2266 std::sort(Sections.begin(), Sections.end(), SectionSort);
2268 // Build a set of address spans, sorted by CU.
2269 for (const MCSection *Section : Sections) {
2270 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2271 if (List.size() < 2)
2274 // Sort the symbols by offset within the section.
2275 std::sort(List.begin(), List.end(),
2276 [&](const SymbolCU &A, const SymbolCU &B) {
2277 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2278 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2280 // Symbols with no order assigned should be placed at the end.
2281 // (e.g. section end labels)
2289 // If we have no section (e.g. common), just write out
2290 // individual spans for each symbol.
2292 for (const SymbolCU &Cur : List) {
2294 Span.Start = Cur.Sym;
2297 Spans[Cur.CU].push_back(Span);
2300 // Build spans between each label.
2301 const MCSymbol *StartSym = List[0].Sym;
2302 for (size_t n = 1, e = List.size(); n < e; n++) {
2303 const SymbolCU &Prev = List[n - 1];
2304 const SymbolCU &Cur = List[n];
2306 // Try and build the longest span we can within the same CU.
2307 if (Cur.CU != Prev.CU) {
2309 Span.Start = StartSym;
2311 Spans[Prev.CU].push_back(Span);
2318 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2320 // Build a list of CUs used.
2321 std::vector<DwarfCompileUnit *> CUs;
2322 for (const auto &it : Spans) {
2323 DwarfCompileUnit *CU = it.first;
2327 // Sort the CU list (again, to ensure consistent output order).
2328 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2329 return A->getUniqueID() < B->getUniqueID();
2332 // Emit an arange table for each CU we used.
2333 for (DwarfCompileUnit *CU : CUs) {
2334 std::vector<ArangeSpan> &List = Spans[CU];
2336 // Emit size of content not including length itself.
2337 unsigned ContentSize =
2338 sizeof(int16_t) + // DWARF ARange version number
2339 sizeof(int32_t) + // Offset of CU in the .debug_info section
2340 sizeof(int8_t) + // Pointer Size (in bytes)
2341 sizeof(int8_t); // Segment Size (in bytes)
2343 unsigned TupleSize = PtrSize * 2;
2345 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2347 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2349 ContentSize += Padding;
2350 ContentSize += (List.size() + 1) * TupleSize;
2352 // For each compile unit, write the list of spans it covers.
2353 Asm->OutStreamer.AddComment("Length of ARange Set");
2354 Asm->EmitInt32(ContentSize);
2355 Asm->OutStreamer.AddComment("DWARF Arange version number");
2356 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2357 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2358 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2359 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2360 Asm->EmitInt8(PtrSize);
2361 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2364 Asm->OutStreamer.EmitFill(Padding, 0xff);
2366 for (const ArangeSpan &Span : List) {
2367 Asm->EmitLabelReference(Span.Start, PtrSize);
2369 // Calculate the size as being from the span start to it's end.
2371 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2373 // For symbols without an end marker (e.g. common), we
2374 // write a single arange entry containing just that one symbol.
2375 uint64_t Size = SymSize[Span.Start];
2379 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2383 Asm->OutStreamer.AddComment("ARange terminator");
2384 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2385 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2389 // Emit visible names into a debug ranges section.
2390 void DwarfDebug::emitDebugRanges() {
2391 // Start the dwarf ranges section.
2392 Asm->OutStreamer.SwitchSection(
2393 Asm->getObjFileLowering().getDwarfRangesSection());
2395 // Size for our labels.
2396 unsigned char Size = Asm->getDataLayout().getPointerSize();
2398 // Grab the specific ranges for the compile units in the module.
2399 for (const auto &I : CUMap) {
2400 DwarfCompileUnit *TheCU = I.second;
2402 // Iterate over the misc ranges for the compile units in the module.
2403 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2404 // Emit our symbol so we can find the beginning of the range.
2405 Asm->OutStreamer.EmitLabel(List.getSym());
2407 for (const RangeSpan &Range : List.getRanges()) {
2408 const MCSymbol *Begin = Range.getStart();
2409 const MCSymbol *End = Range.getEnd();
2410 assert(Begin && "Range without a begin symbol?");
2411 assert(End && "Range without an end symbol?");
2412 if (TheCU->getRanges().size() == 1) {
2413 // Grab the begin symbol from the first range as our base.
2414 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2415 Asm->EmitLabelDifference(Begin, Base, Size);
2416 Asm->EmitLabelDifference(End, Base, Size);
2418 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2419 Asm->OutStreamer.EmitSymbolValue(End, Size);
2423 // And terminate the list with two 0 values.
2424 Asm->OutStreamer.EmitIntValue(0, Size);
2425 Asm->OutStreamer.EmitIntValue(0, Size);
2428 // Now emit a range for the CU itself.
2429 if (TheCU->getRanges().size() > 1) {
2430 Asm->OutStreamer.EmitLabel(
2431 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2432 for (const RangeSpan &Range : TheCU->getRanges()) {
2433 const MCSymbol *Begin = Range.getStart();
2434 const MCSymbol *End = Range.getEnd();
2435 assert(Begin && "Range without a begin symbol?");
2436 assert(End && "Range without an end symbol?");
2437 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2438 Asm->OutStreamer.EmitSymbolValue(End, Size);
2440 // And terminate the list with two 0 values.
2441 Asm->OutStreamer.EmitIntValue(0, Size);
2442 Asm->OutStreamer.EmitIntValue(0, Size);
2447 // DWARF5 Experimental Separate Dwarf emitters.
2449 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2450 std::unique_ptr<DwarfUnit> NewU) {
2451 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2452 U.getCUNode().getSplitDebugFilename());
2454 if (!CompilationDir.empty())
2455 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2457 addGnuPubAttributes(*NewU, Die);
2459 SkeletonHolder.addUnit(std::move(NewU));
2462 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2463 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2464 // DW_AT_addr_base, DW_AT_ranges_base.
2465 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2467 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2468 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2469 DwarfCompileUnit &NewCU = *OwnedUnit;
2470 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2471 DwarfInfoSectionSym);
2473 NewCU.initStmtList(DwarfLineSectionSym);
2475 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2480 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2482 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2483 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2484 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2486 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2488 DwarfTypeUnit &NewTU = *OwnedUnit;
2489 NewTU.setTypeSignature(TU.getTypeSignature());
2490 NewTU.setType(nullptr);
2492 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2494 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2498 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2499 // compile units that would normally be in debug_info.
2500 void DwarfDebug::emitDebugInfoDWO() {
2501 assert(useSplitDwarf() && "No split dwarf debug info?");
2502 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2503 // emit relocations into the dwo file.
2504 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2507 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2508 // abbreviations for the .debug_info.dwo section.
2509 void DwarfDebug::emitDebugAbbrevDWO() {
2510 assert(useSplitDwarf() && "No split dwarf?");
2511 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2514 void DwarfDebug::emitDebugLineDWO() {
2515 assert(useSplitDwarf() && "No split dwarf?");
2516 Asm->OutStreamer.SwitchSection(
2517 Asm->getObjFileLowering().getDwarfLineDWOSection());
2518 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2521 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2522 // string section and is identical in format to traditional .debug_str
2524 void DwarfDebug::emitDebugStrDWO() {
2525 assert(useSplitDwarf() && "No split dwarf?");
2526 const MCSection *OffSec =
2527 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2528 const MCSymbol *StrSym = DwarfStrSectionSym;
2529 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2533 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2534 if (!useSplitDwarf())
2537 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2538 return &SplitTypeUnitFileTable;
2541 static uint64_t makeTypeSignature(StringRef Identifier) {
2543 Hash.update(Identifier);
2544 // ... take the least significant 8 bytes and return those. Our MD5
2545 // implementation always returns its results in little endian, swap bytes
2547 MD5::MD5Result Result;
2549 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2552 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2553 StringRef Identifier, DIE &RefDie,
2554 DICompositeType CTy) {
2555 // Fast path if we're building some type units and one has already used the
2556 // address pool we know we're going to throw away all this work anyway, so
2557 // don't bother building dependent types.
2558 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2561 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2563 CU.addDIETypeSignature(RefDie, *TU);
2567 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2568 AddrPool.resetUsedFlag();
2570 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2571 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2572 this, &InfoHolder, getDwoLineTable(CU));
2573 DwarfTypeUnit &NewTU = *OwnedUnit;
2574 DIE &UnitDie = NewTU.getUnitDie();
2576 TypeUnitsUnderConstruction.push_back(
2577 std::make_pair(std::move(OwnedUnit), CTy));
2579 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2582 uint64_t Signature = makeTypeSignature(Identifier);
2583 NewTU.setTypeSignature(Signature);
2585 if (useSplitDwarf())
2586 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2587 DwarfTypesDWOSectionSym);
2589 CU.applyStmtList(UnitDie);
2591 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2594 NewTU.setType(NewTU.createTypeDIE(CTy));
2597 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2598 TypeUnitsUnderConstruction.clear();
2600 // Types referencing entries in the address table cannot be placed in type
2602 if (AddrPool.hasBeenUsed()) {
2604 // Remove all the types built while building this type.
2605 // This is pessimistic as some of these types might not be dependent on
2606 // the type that used an address.
2607 for (const auto &TU : TypeUnitsToAdd)
2608 DwarfTypeUnits.erase(TU.second);
2610 // Construct this type in the CU directly.
2611 // This is inefficient because all the dependent types will be rebuilt
2612 // from scratch, including building them in type units, discovering that
2613 // they depend on addresses, throwing them out and rebuilding them.
2614 CU.constructTypeDIE(RefDie, CTy);
2618 // If the type wasn't dependent on fission addresses, finish adding the type
2619 // and all its dependent types.
2620 for (auto &TU : TypeUnitsToAdd) {
2621 if (useSplitDwarf())
2622 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2623 InfoHolder.addUnit(std::move(TU.first));
2626 CU.addDIETypeSignature(RefDie, NewTU);
2629 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2630 MCSymbol *Begin, MCSymbol *End) {
2631 assert(Begin && "Begin label should not be null!");
2632 assert(End && "End label should not be null!");
2633 assert(Begin->isDefined() && "Invalid starting label");
2634 assert(End->isDefined() && "Invalid end label");
2636 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2637 if (DwarfVersion < 4)
2638 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2640 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2643 // Accelerator table mutators - add each name along with its companion
2644 // DIE to the proper table while ensuring that the name that we're going
2645 // to reference is in the string table. We do this since the names we
2646 // add may not only be identical to the names in the DIE.
2647 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2648 if (!useDwarfAccelTables())
2650 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2654 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2655 if (!useDwarfAccelTables())
2657 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2661 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2662 if (!useDwarfAccelTables())
2664 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2668 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2669 if (!useDwarfAccelTables())
2671 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),