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();
800 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
801 // in the ConcreteVariables list, rather than looking it up again here.
802 // DIE::getUnit isn't simple - it walks parent pointers, etc.
803 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
805 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
806 if (AbsVar && AbsVar->getDIE()) {
807 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
810 Unit->applyVariableAttributes(*Var, *VariableDie);
814 void DwarfDebug::finishSubprogramDefinitions() {
815 const Module *M = MMI->getModule();
817 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
818 for (MDNode *N : CU_Nodes->operands()) {
819 DICompileUnit TheCU(N);
820 // Construct subprogram DIE and add variables DIEs.
821 DwarfCompileUnit *SPCU =
822 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
823 DIArray Subprograms = TheCU.getSubprograms();
824 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
825 DISubprogram SP(Subprograms.getElement(i));
826 // Perhaps the subprogram is in another CU (such as due to comdat
827 // folding, etc), in which case ignore it here.
828 if (SPMap[SP] != SPCU)
830 DIE *D = SPCU->getDIE(SP);
831 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
833 // If this subprogram has an abstract definition, reference that
834 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
837 // Lazily construct the subprogram if we didn't see either concrete or
838 // inlined versions during codegen.
839 D = SPCU->getOrCreateSubprogramDIE(SP);
840 // And attach the attributes
841 SPCU->applySubprogramAttributesToDefinition(SP, *D);
848 // Collect info for variables that were optimized out.
849 void DwarfDebug::collectDeadVariables() {
850 const Module *M = MMI->getModule();
852 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
853 for (MDNode *N : CU_Nodes->operands()) {
854 DICompileUnit TheCU(N);
855 // Construct subprogram DIE and add variables DIEs.
856 DwarfCompileUnit *SPCU =
857 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
858 assert(SPCU && "Unable to find Compile Unit!");
859 DIArray Subprograms = TheCU.getSubprograms();
860 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
861 DISubprogram SP(Subprograms.getElement(i));
862 if (ProcessedSPNodes.count(SP) != 0)
864 assert(SP.isSubprogram() &&
865 "CU's subprogram list contains a non-subprogram");
866 assert(SP.isDefinition() &&
867 "CU's subprogram list contains a subprogram declaration");
868 DIArray Variables = SP.getVariables();
869 if (Variables.getNumElements() == 0)
872 DIE *SPDIE = AbstractSPDies.lookup(SP);
874 SPDIE = SPCU->getDIE(SP);
876 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
877 DIVariable DV(Variables.getElement(vi));
878 assert(DV.isVariable());
879 DbgVariable NewVar(DV, this);
880 auto VariableDie = SPCU->constructVariableDIE(NewVar);
881 SPCU->applyVariableAttributes(NewVar, *VariableDie);
882 SPDIE->addChild(std::move(VariableDie));
889 void DwarfDebug::finalizeModuleInfo() {
890 finishSubprogramDefinitions();
892 finishVariableDefinitions();
894 // Collect info for variables that were optimized out.
895 collectDeadVariables();
897 // Handle anything that needs to be done on a per-unit basis after
898 // all other generation.
899 for (const auto &TheU : getUnits()) {
900 // Emit DW_AT_containing_type attribute to connect types with their
901 // vtable holding type.
902 TheU->constructContainingTypeDIEs();
904 // Add CU specific attributes if we need to add any.
905 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
906 // If we're splitting the dwarf out now that we've got the entire
907 // CU then add the dwo id to it.
908 DwarfCompileUnit *SkCU =
909 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
910 if (useSplitDwarf()) {
911 // Emit a unique identifier for this CU.
912 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
913 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
914 dwarf::DW_FORM_data8, ID);
915 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
916 dwarf::DW_FORM_data8, ID);
918 // We don't keep track of which addresses are used in which CU so this
919 // is a bit pessimistic under LTO.
920 if (!AddrPool.isEmpty())
921 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
922 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
923 DwarfAddrSectionSym);
924 if (!TheU->getRangeLists().empty())
925 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
926 dwarf::DW_AT_GNU_ranges_base,
927 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
930 // If we have code split among multiple sections or non-contiguous
931 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
932 // remain in the .o file, otherwise add a DW_AT_low_pc.
933 // FIXME: We should use ranges allow reordering of code ala
934 // .subsections_via_symbols in mach-o. This would mean turning on
935 // ranges for all subprogram DIEs for mach-o.
936 DwarfCompileUnit &U =
937 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
938 unsigned NumRanges = TheU->getRanges().size();
941 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
942 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
943 DwarfDebugRangeSectionSym);
945 // A DW_AT_low_pc attribute may also be specified in combination with
946 // DW_AT_ranges to specify the default base address for use in
947 // location lists (see Section 2.6.2) and range lists (see Section
949 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
952 RangeSpan &Range = TheU->getRanges().back();
953 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
955 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
962 // Compute DIE offsets and sizes.
963 InfoHolder.computeSizeAndOffsets();
965 SkeletonHolder.computeSizeAndOffsets();
968 void DwarfDebug::endSections() {
969 // Filter labels by section.
970 for (const SymbolCU &SCU : ArangeLabels) {
971 if (SCU.Sym->isInSection()) {
972 // Make a note of this symbol and it's section.
973 const MCSection *Section = &SCU.Sym->getSection();
974 if (!Section->getKind().isMetadata())
975 SectionMap[Section].push_back(SCU);
977 // Some symbols (e.g. common/bss on mach-o) can have no section but still
978 // appear in the output. This sucks as we rely on sections to build
979 // arange spans. We can do it without, but it's icky.
980 SectionMap[nullptr].push_back(SCU);
984 // Build a list of sections used.
985 std::vector<const MCSection *> Sections;
986 for (const auto &it : SectionMap) {
987 const MCSection *Section = it.first;
988 Sections.push_back(Section);
991 // Sort the sections into order.
992 // This is only done to ensure consistent output order across different runs.
993 std::sort(Sections.begin(), Sections.end(), SectionSort);
995 // Add terminating symbols for each section.
996 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
997 const MCSection *Section = Sections[ID];
998 MCSymbol *Sym = nullptr;
1001 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1002 // if we know the section name up-front. For user-created sections, the
1003 // resulting label may not be valid to use as a label. (section names can
1004 // use a greater set of characters on some systems)
1005 Sym = Asm->GetTempSymbol("debug_end", ID);
1006 Asm->OutStreamer.SwitchSection(Section);
1007 Asm->OutStreamer.EmitLabel(Sym);
1010 // Insert a final terminator.
1011 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1015 // Emit all Dwarf sections that should come after the content.
1016 void DwarfDebug::endModule() {
1017 assert(CurFn == nullptr);
1018 assert(CurMI == nullptr);
1023 // End any existing sections.
1024 // TODO: Does this need to happen?
1027 // Finalize the debug info for the module.
1028 finalizeModuleInfo();
1032 // Emit all the DIEs into a debug info section.
1035 // Corresponding abbreviations into a abbrev section.
1036 emitAbbreviations();
1038 // Emit info into a debug aranges section.
1039 if (GenerateARangeSection)
1042 // Emit info into a debug ranges section.
1045 if (useSplitDwarf()) {
1048 emitDebugAbbrevDWO();
1051 // Emit DWO addresses.
1052 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1054 // Emit info into a debug loc section.
1057 // Emit info into the dwarf accelerator table sections.
1058 if (useDwarfAccelTables()) {
1061 emitAccelNamespaces();
1065 // Emit the pubnames and pubtypes sections if requested.
1066 if (HasDwarfPubSections) {
1067 emitDebugPubNames(GenerateGnuPubSections);
1068 emitDebugPubTypes(GenerateGnuPubSections);
1073 AbstractVariables.clear();
1075 // Reset these for the next Module if we have one.
1079 // Find abstract variable, if any, associated with Var.
1080 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1081 DIVariable &Cleansed) {
1082 LLVMContext &Ctx = DV->getContext();
1083 // More then one inlined variable corresponds to one abstract variable.
1084 // FIXME: This duplication of variables when inlining should probably be
1085 // removed. It's done to allow each DIVariable to describe its location
1086 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1087 // make it accurate then remove this duplication/cleansing stuff.
1088 Cleansed = cleanseInlinedVariable(DV, Ctx);
1089 auto I = AbstractVariables.find(Cleansed);
1090 if (I != AbstractVariables.end())
1091 return I->second.get();
1095 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1096 DIVariable Cleansed;
1097 return getExistingAbstractVariable(DV, Cleansed);
1100 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1101 LexicalScope *Scope) {
1102 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1103 addScopeVariable(Scope, AbsDbgVariable.get());
1104 AbstractVariables[Var] = std::move(AbsDbgVariable);
1107 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1108 const MDNode *ScopeNode) {
1109 DIVariable Cleansed = DV;
1110 if (getExistingAbstractVariable(DV, Cleansed))
1113 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1117 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1118 const MDNode *ScopeNode) {
1119 DIVariable Cleansed = DV;
1120 if (getExistingAbstractVariable(DV, Cleansed))
1123 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1124 createAbstractVariable(Cleansed, Scope);
1127 // If Var is a current function argument then add it to CurrentFnArguments list.
1128 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1129 if (!LScopes.isCurrentFunctionScope(Scope))
1131 DIVariable DV = Var->getVariable();
1132 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1134 unsigned ArgNo = DV.getArgNumber();
1138 size_t Size = CurrentFnArguments.size();
1140 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1141 // llvm::Function argument size is not good indicator of how many
1142 // arguments does the function have at source level.
1144 CurrentFnArguments.resize(ArgNo * 2);
1145 assert(!CurrentFnArguments[ArgNo - 1]);
1146 CurrentFnArguments[ArgNo - 1] = Var;
1150 // Collect variable information from side table maintained by MMI.
1151 void DwarfDebug::collectVariableInfoFromMMITable(
1152 SmallPtrSet<const MDNode *, 16> &Processed) {
1153 for (const auto &VI : MMI->getVariableDbgInfo()) {
1156 Processed.insert(VI.Var);
1157 DIVariable DV(VI.Var);
1158 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1160 // If variable scope is not found then skip this variable.
1164 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1165 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1166 DbgVariable *RegVar = ConcreteVariables.back().get();
1167 RegVar->setFrameIndex(VI.Slot);
1168 addScopeVariable(Scope, RegVar);
1172 // Get .debug_loc entry for the instruction range starting at MI.
1173 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1174 const MDNode *Var = MI->getDebugVariable();
1176 assert(MI->getNumOperands() == 3);
1177 if (MI->getOperand(0).isReg()) {
1178 MachineLocation MLoc;
1179 // If the second operand is an immediate, this is a
1180 // register-indirect address.
1181 if (!MI->getOperand(1).isImm())
1182 MLoc.set(MI->getOperand(0).getReg());
1184 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1185 return DebugLocEntry::Value(Var, MLoc);
1187 if (MI->getOperand(0).isImm())
1188 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1189 if (MI->getOperand(0).isFPImm())
1190 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1191 if (MI->getOperand(0).isCImm())
1192 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1194 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1197 /// Determine whether two variable pieces overlap.
1198 static bool piecesOverlap(DIVariable P1, DIVariable P2) {
1199 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1201 unsigned l1 = P1.getPieceOffset();
1202 unsigned l2 = P2.getPieceOffset();
1203 unsigned r1 = l1 + P1.getPieceSize();
1204 unsigned r2 = l2 + P2.getPieceSize();
1205 // True where [l1,r1[ and [r1,r2[ overlap.
1206 return (l1 < r2) && (l2 < r1);
1209 /// Build the location list for all DBG_VALUEs in the function that
1210 /// describe the same variable. If the ranges of several independent
1211 /// pieces of the same variable overlap partially, split them up and
1212 /// combine the ranges. The resulting DebugLocEntries are will have
1213 /// strict monotonically increasing begin addresses and will never
1218 // Ranges History [var, loc, piece ofs size]
1219 // 0 | [x, (reg0, piece 0, 32)]
1220 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1222 // 3 | [clobber reg0]
1223 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1227 // [0-1] [x, (reg0, piece 0, 32)]
1228 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1229 // [3-4] [x, (reg1, piece 32, 32)]
1230 // [4- ] [x, (mem, piece 0, 64)]
1232 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1233 const DbgValueHistoryMap::InstrRanges &Ranges) {
1234 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
1236 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1237 const MachineInstr *Begin = I->first;
1238 const MachineInstr *End = I->second;
1239 assert(Begin->isDebugValue() && "Invalid History entry");
1241 // Check if a variable is inaccessible in this range.
1242 if (!Begin->isDebugValue() ||
1243 (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1244 !Begin->getOperand(0).getReg())) {
1249 // If this piece overlaps with any open ranges, truncate them.
1250 DIVariable DIVar = Begin->getDebugVariable();
1251 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
1252 [&](DebugLocEntry::Value R) {
1253 return piecesOverlap(DIVar, R.getVariable());
1255 OpenRanges.erase(Last, OpenRanges.end());
1257 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1258 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1260 const MCSymbol *EndLabel;
1262 EndLabel = getLabelAfterInsn(End);
1263 else if (std::next(I) == Ranges.end())
1264 EndLabel = FunctionEndSym;
1266 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1267 assert(EndLabel && "Forgot label after instruction ending a range!");
1269 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1271 auto Value = getDebugLocValue(Begin);
1272 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1273 bool couldMerge = false;
1275 // If this is a piece, it may belong to the current DebugLocEntry.
1276 if (DIVar.isVariablePiece()) {
1277 // Add this value to the list of open ranges.
1278 OpenRanges.push_back(Value);
1280 // Attempt to add the piece to the last entry.
1281 if (!DebugLoc.empty())
1282 if (DebugLoc.back().MergeValues(Loc))
1287 // Need to add a new DebugLocEntry. Add all values from still
1288 // valid non-overlapping pieces.
1289 if (OpenRanges.size())
1290 Loc.addValues(OpenRanges);
1292 DebugLoc.push_back(std::move(Loc));
1295 // Attempt to coalesce the ranges of two otherwise identical
1297 auto CurEntry = DebugLoc.rbegin();
1298 auto PrevEntry = std::next(CurEntry);
1299 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1300 DebugLoc.pop_back();
1302 DEBUG(dbgs() << "Values:\n";
1303 for (auto Value : CurEntry->getValues())
1304 Value.getVariable()->dump();
1305 dbgs() << "-----\n");
1310 // Find variables for each lexical scope.
1312 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1313 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1314 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1316 // Grab the variable info that was squirreled away in the MMI side-table.
1317 collectVariableInfoFromMMITable(Processed);
1319 for (const auto &I : DbgValues) {
1320 DIVariable DV(I.first);
1321 if (Processed.count(DV))
1324 // Instruction ranges, specifying where DV is accessible.
1325 const auto &Ranges = I.second;
1329 LexicalScope *Scope = nullptr;
1330 if (MDNode *IA = DV.getInlinedAt()) {
1331 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1332 Scope = LScopes.findInlinedScope(DebugLoc::get(
1333 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1335 Scope = LScopes.findLexicalScope(DV.getContext());
1336 // If variable scope is not found then skip this variable.
1340 Processed.insert(getEntireVariable(DV));
1341 const MachineInstr *MInsn = Ranges.front().first;
1342 assert(MInsn->isDebugValue() && "History must begin with debug value");
1343 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1344 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1345 DbgVariable *RegVar = ConcreteVariables.back().get();
1346 addScopeVariable(Scope, RegVar);
1348 // Check if the first DBG_VALUE is valid for the rest of the function.
1349 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1352 // Handle multiple DBG_VALUE instructions describing one variable.
1353 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1355 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1356 DebugLocList &LocList = DotDebugLocEntries.back();
1359 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1361 // Build the location list for this variable.
1362 buildLocationList(LocList.List, Ranges);
1365 // Collect info for variables that were optimized out.
1366 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1367 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1368 DIVariable DV(Variables.getElement(i));
1369 assert(DV.isVariable());
1370 if (!Processed.insert(DV))
1372 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1373 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1374 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1375 addScopeVariable(Scope, ConcreteVariables.back().get());
1380 // Return Label preceding the instruction.
1381 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1382 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1383 assert(Label && "Didn't insert label before instruction");
1387 // Return Label immediately following the instruction.
1388 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1389 return LabelsAfterInsn.lookup(MI);
1392 // Process beginning of an instruction.
1393 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1394 assert(CurMI == nullptr);
1396 // Check if source location changes, but ignore DBG_VALUE locations.
1397 if (!MI->isDebugValue()) {
1398 DebugLoc DL = MI->getDebugLoc();
1399 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1402 if (DL == PrologEndLoc) {
1403 Flags |= DWARF2_FLAG_PROLOGUE_END;
1404 PrologEndLoc = DebugLoc();
1406 if (PrologEndLoc.isUnknown())
1407 Flags |= DWARF2_FLAG_IS_STMT;
1409 if (!DL.isUnknown()) {
1410 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1411 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1413 recordSourceLine(0, 0, nullptr, 0);
1417 // Insert labels where requested.
1418 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1419 LabelsBeforeInsn.find(MI);
1422 if (I == LabelsBeforeInsn.end())
1425 // Label already assigned.
1430 PrevLabel = MMI->getContext().CreateTempSymbol();
1431 Asm->OutStreamer.EmitLabel(PrevLabel);
1433 I->second = PrevLabel;
1436 // Process end of an instruction.
1437 void DwarfDebug::endInstruction() {
1438 assert(CurMI != nullptr);
1439 // Don't create a new label after DBG_VALUE instructions.
1440 // They don't generate code.
1441 if (!CurMI->isDebugValue())
1442 PrevLabel = nullptr;
1444 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1445 LabelsAfterInsn.find(CurMI);
1449 if (I == LabelsAfterInsn.end())
1452 // Label already assigned.
1456 // We need a label after this instruction.
1458 PrevLabel = MMI->getContext().CreateTempSymbol();
1459 Asm->OutStreamer.EmitLabel(PrevLabel);
1461 I->second = PrevLabel;
1464 // Each LexicalScope has first instruction and last instruction to mark
1465 // beginning and end of a scope respectively. Create an inverse map that list
1466 // scopes starts (and ends) with an instruction. One instruction may start (or
1467 // end) multiple scopes. Ignore scopes that are not reachable.
1468 void DwarfDebug::identifyScopeMarkers() {
1469 SmallVector<LexicalScope *, 4> WorkList;
1470 WorkList.push_back(LScopes.getCurrentFunctionScope());
1471 while (!WorkList.empty()) {
1472 LexicalScope *S = WorkList.pop_back_val();
1474 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1475 if (!Children.empty())
1476 WorkList.append(Children.begin(), Children.end());
1478 if (S->isAbstractScope())
1481 for (const InsnRange &R : S->getRanges()) {
1482 assert(R.first && "InsnRange does not have first instruction!");
1483 assert(R.second && "InsnRange does not have second instruction!");
1484 requestLabelBeforeInsn(R.first);
1485 requestLabelAfterInsn(R.second);
1490 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1491 // First known non-DBG_VALUE and non-frame setup location marks
1492 // the beginning of the function body.
1493 for (const auto &MBB : *MF)
1494 for (const auto &MI : MBB)
1495 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1496 !MI.getDebugLoc().isUnknown())
1497 return MI.getDebugLoc();
1501 // Gather pre-function debug information. Assumes being called immediately
1502 // after the function entry point has been emitted.
1503 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1506 // If there's no debug info for the function we're not going to do anything.
1507 if (!MMI->hasDebugInfo())
1510 auto DI = FunctionDIs.find(MF->getFunction());
1511 if (DI == FunctionDIs.end())
1514 // Grab the lexical scopes for the function, if we don't have any of those
1515 // then we're not going to be able to do anything.
1516 LScopes.initialize(*MF);
1517 if (LScopes.empty())
1520 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1522 // Make sure that each lexical scope will have a begin/end label.
1523 identifyScopeMarkers();
1525 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1526 // belongs to so that we add to the correct per-cu line table in the
1528 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1529 // FnScope->getScopeNode() and DI->second should represent the same function,
1530 // though they may not be the same MDNode due to inline functions merged in
1531 // LTO where the debug info metadata still differs (either due to distinct
1532 // written differences - two versions of a linkonce_odr function
1533 // written/copied into two separate files, or some sub-optimal metadata that
1534 // isn't structurally identical (see: file path/name info from clang, which
1535 // includes the directory of the cpp file being built, even when the file name
1536 // is absolute (such as an <> lookup header)))
1537 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1538 assert(TheCU && "Unable to find compile unit!");
1539 if (Asm->OutStreamer.hasRawTextSupport())
1540 // Use a single line table if we are generating assembly.
1541 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1543 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1545 // Emit a label for the function so that we have a beginning address.
1546 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1547 // Assumes in correct section after the entry point.
1548 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1550 // Calculate history for local variables.
1551 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1554 // Request labels for the full history.
1555 for (const auto &I : DbgValues) {
1556 const auto &Ranges = I.second;
1560 // The first mention of a function argument gets the FunctionBeginSym
1561 // label, so arguments are visible when breaking at function entry.
1562 DIVariable DV(Ranges.front().first->getDebugVariable());
1563 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1564 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1565 if (!DV.isVariablePiece())
1566 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1568 // Mark all non-overlapping initial pieces.
1569 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1570 DIVariable Piece = I->first->getDebugVariable();
1571 if (std::all_of(Ranges.begin(), I,
1572 [&](DbgValueHistoryMap::InstrRange Pred){
1573 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1575 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1582 for (const auto &Range : Ranges) {
1583 requestLabelBeforeInsn(Range.first);
1585 requestLabelAfterInsn(Range.second);
1589 PrevInstLoc = DebugLoc();
1590 PrevLabel = FunctionBeginSym;
1592 // Record beginning of function.
1593 PrologEndLoc = findPrologueEndLoc(MF);
1594 if (!PrologEndLoc.isUnknown()) {
1595 DebugLoc FnStartDL =
1596 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1598 FnStartDL.getLine(), FnStartDL.getCol(),
1599 FnStartDL.getScope(MF->getFunction()->getContext()),
1600 // We'd like to list the prologue as "not statements" but GDB behaves
1601 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1602 DWARF2_FLAG_IS_STMT);
1606 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1607 if (addCurrentFnArgument(Var, LS))
1609 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1610 DIVariable DV = Var->getVariable();
1611 // Variables with positive arg numbers are parameters.
1612 if (unsigned ArgNum = DV.getArgNumber()) {
1613 // Keep all parameters in order at the start of the variable list to ensure
1614 // function types are correct (no out-of-order parameters)
1616 // This could be improved by only doing it for optimized builds (unoptimized
1617 // builds have the right order to begin with), searching from the back (this
1618 // would catch the unoptimized case quickly), or doing a binary search
1619 // rather than linear search.
1620 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1621 while (I != Vars.end()) {
1622 unsigned CurNum = (*I)->getVariable().getArgNumber();
1623 // A local (non-parameter) variable has been found, insert immediately
1627 // A later indexed parameter has been found, insert immediately before it.
1628 if (CurNum > ArgNum)
1632 Vars.insert(I, Var);
1636 Vars.push_back(Var);
1639 // Gather and emit post-function debug information.
1640 void DwarfDebug::endFunction(const MachineFunction *MF) {
1641 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1642 // though the beginFunction may not be called at all.
1643 // We should handle both cases.
1647 assert(CurFn == MF);
1648 assert(CurFn != nullptr);
1650 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1651 !FunctionDIs.count(MF->getFunction())) {
1652 // If we don't have a lexical scope for this function then there will
1653 // be a hole in the range information. Keep note of this by setting the
1654 // previously used section to nullptr.
1655 PrevSection = nullptr;
1661 // Define end label for subprogram.
1662 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1663 // Assumes in correct section after the entry point.
1664 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1666 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1667 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1669 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1670 collectVariableInfo(ProcessedVars);
1672 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1673 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1675 // Construct abstract scopes.
1676 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1677 DISubprogram SP(AScope->getScopeNode());
1678 assert(SP.isSubprogram());
1679 // Collect info for variables that were optimized out.
1680 DIArray Variables = SP.getVariables();
1681 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1682 DIVariable DV(Variables.getElement(i));
1683 assert(DV && DV.isVariable());
1684 if (!ProcessedVars.insert(DV))
1686 ensureAbstractVariableIsCreated(DV, DV.getContext());
1688 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1691 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1692 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1693 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1695 // Add the range of this function to the list of ranges for the CU.
1696 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1697 TheCU.addRange(std::move(Span));
1698 PrevSection = Asm->getCurrentSection();
1702 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1703 // DbgVariables except those that are also in AbstractVariables (since they
1704 // can be used cross-function)
1705 ScopeVariables.clear();
1706 CurrentFnArguments.clear();
1708 LabelsBeforeInsn.clear();
1709 LabelsAfterInsn.clear();
1710 PrevLabel = nullptr;
1714 // Register a source line with debug info. Returns the unique label that was
1715 // emitted and which provides correspondence to the source line list.
1716 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1721 unsigned Discriminator = 0;
1722 if (DIScope Scope = DIScope(S)) {
1723 assert(Scope.isScope());
1724 Fn = Scope.getFilename();
1725 Dir = Scope.getDirectory();
1726 if (Scope.isLexicalBlock())
1727 Discriminator = DILexicalBlock(S).getDiscriminator();
1729 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1730 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1731 .getOrCreateSourceID(Fn, Dir);
1733 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1737 //===----------------------------------------------------------------------===//
1739 //===----------------------------------------------------------------------===//
1741 // Emit initial Dwarf sections with a label at the start of each one.
1742 void DwarfDebug::emitSectionLabels() {
1743 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1745 // Dwarf sections base addresses.
1746 DwarfInfoSectionSym =
1747 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1748 if (useSplitDwarf()) {
1749 DwarfInfoDWOSectionSym =
1750 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1751 DwarfTypesDWOSectionSym =
1752 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1754 DwarfAbbrevSectionSym =
1755 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1756 if (useSplitDwarf())
1757 DwarfAbbrevDWOSectionSym = emitSectionSym(
1758 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1759 if (GenerateARangeSection)
1760 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1762 DwarfLineSectionSym =
1763 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1764 if (GenerateGnuPubSections) {
1765 DwarfGnuPubNamesSectionSym =
1766 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1767 DwarfGnuPubTypesSectionSym =
1768 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1769 } else if (HasDwarfPubSections) {
1770 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1771 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1774 DwarfStrSectionSym =
1775 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1776 if (useSplitDwarf()) {
1777 DwarfStrDWOSectionSym =
1778 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1779 DwarfAddrSectionSym =
1780 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1781 DwarfDebugLocSectionSym =
1782 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1784 DwarfDebugLocSectionSym =
1785 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1786 DwarfDebugRangeSectionSym =
1787 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1790 // Recursively emits a debug information entry.
1791 void DwarfDebug::emitDIE(DIE &Die) {
1792 // Get the abbreviation for this DIE.
1793 const DIEAbbrev &Abbrev = Die.getAbbrev();
1795 // Emit the code (index) for the abbreviation.
1796 if (Asm->isVerbose())
1797 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1798 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1799 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1800 dwarf::TagString(Abbrev.getTag()));
1801 Asm->EmitULEB128(Abbrev.getNumber());
1803 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1804 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1806 // Emit the DIE attribute values.
1807 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1808 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1809 dwarf::Form Form = AbbrevData[i].getForm();
1810 assert(Form && "Too many attributes for DIE (check abbreviation)");
1812 if (Asm->isVerbose()) {
1813 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1814 if (Attr == dwarf::DW_AT_accessibility)
1815 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1816 cast<DIEInteger>(Values[i])->getValue()));
1819 // Emit an attribute using the defined form.
1820 Values[i]->EmitValue(Asm, Form);
1823 // Emit the DIE children if any.
1824 if (Abbrev.hasChildren()) {
1825 for (auto &Child : Die.getChildren())
1828 Asm->OutStreamer.AddComment("End Of Children Mark");
1833 // Emit the debug info section.
1834 void DwarfDebug::emitDebugInfo() {
1835 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1837 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1840 // Emit the abbreviation section.
1841 void DwarfDebug::emitAbbreviations() {
1842 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1844 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1847 // Emit the last address of the section and the end of the line matrix.
1848 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1849 // Define last address of section.
1850 Asm->OutStreamer.AddComment("Extended Op");
1853 Asm->OutStreamer.AddComment("Op size");
1854 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1855 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1856 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1858 Asm->OutStreamer.AddComment("Section end label");
1860 Asm->OutStreamer.EmitSymbolValue(
1861 Asm->GetTempSymbol("section_end", SectionEnd),
1862 Asm->getDataLayout().getPointerSize());
1864 // Mark end of matrix.
1865 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1871 // Emit visible names into a hashed accelerator table section.
1872 void DwarfDebug::emitAccelNames() {
1873 AccelNames.FinalizeTable(Asm, "Names");
1874 Asm->OutStreamer.SwitchSection(
1875 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1876 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1877 Asm->OutStreamer.EmitLabel(SectionBegin);
1879 // Emit the full data.
1880 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1883 // Emit objective C classes and categories into a hashed accelerator table
1885 void DwarfDebug::emitAccelObjC() {
1886 AccelObjC.FinalizeTable(Asm, "ObjC");
1887 Asm->OutStreamer.SwitchSection(
1888 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1889 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1890 Asm->OutStreamer.EmitLabel(SectionBegin);
1892 // Emit the full data.
1893 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1896 // Emit namespace dies into a hashed accelerator table.
1897 void DwarfDebug::emitAccelNamespaces() {
1898 AccelNamespace.FinalizeTable(Asm, "namespac");
1899 Asm->OutStreamer.SwitchSection(
1900 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1901 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1902 Asm->OutStreamer.EmitLabel(SectionBegin);
1904 // Emit the full data.
1905 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1908 // Emit type dies into a hashed accelerator table.
1909 void DwarfDebug::emitAccelTypes() {
1911 AccelTypes.FinalizeTable(Asm, "types");
1912 Asm->OutStreamer.SwitchSection(
1913 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1914 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1915 Asm->OutStreamer.EmitLabel(SectionBegin);
1917 // Emit the full data.
1918 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1921 // Public name handling.
1922 // The format for the various pubnames:
1924 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1925 // for the DIE that is named.
1927 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1928 // into the CU and the index value is computed according to the type of value
1929 // for the DIE that is named.
1931 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1932 // it's the offset within the debug_info/debug_types dwo section, however, the
1933 // reference in the pubname header doesn't change.
1935 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1936 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1938 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1940 // We could have a specification DIE that has our most of our knowledge,
1941 // look for that now.
1942 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1944 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1945 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1946 Linkage = dwarf::GIEL_EXTERNAL;
1947 } else if (Die->findAttribute(dwarf::DW_AT_external))
1948 Linkage = dwarf::GIEL_EXTERNAL;
1950 switch (Die->getTag()) {
1951 case dwarf::DW_TAG_class_type:
1952 case dwarf::DW_TAG_structure_type:
1953 case dwarf::DW_TAG_union_type:
1954 case dwarf::DW_TAG_enumeration_type:
1955 return dwarf::PubIndexEntryDescriptor(
1956 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1957 ? dwarf::GIEL_STATIC
1958 : dwarf::GIEL_EXTERNAL);
1959 case dwarf::DW_TAG_typedef:
1960 case dwarf::DW_TAG_base_type:
1961 case dwarf::DW_TAG_subrange_type:
1962 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1963 case dwarf::DW_TAG_namespace:
1964 return dwarf::GIEK_TYPE;
1965 case dwarf::DW_TAG_subprogram:
1966 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1967 case dwarf::DW_TAG_constant:
1968 case dwarf::DW_TAG_variable:
1969 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1970 case dwarf::DW_TAG_enumerator:
1971 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1972 dwarf::GIEL_STATIC);
1974 return dwarf::GIEK_NONE;
1978 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1980 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1981 const MCSection *PSec =
1982 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1983 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1985 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1988 void DwarfDebug::emitDebugPubSection(
1989 bool GnuStyle, const MCSection *PSec, StringRef Name,
1990 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1991 for (const auto &NU : CUMap) {
1992 DwarfCompileUnit *TheU = NU.second;
1994 const auto &Globals = (TheU->*Accessor)();
1996 if (Globals.empty())
1999 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2001 unsigned ID = TheU->getUniqueID();
2003 // Start the dwarf pubnames section.
2004 Asm->OutStreamer.SwitchSection(PSec);
2007 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2008 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2009 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2010 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2012 Asm->OutStreamer.EmitLabel(BeginLabel);
2014 Asm->OutStreamer.AddComment("DWARF Version");
2015 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2017 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2018 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2020 Asm->OutStreamer.AddComment("Compilation Unit Length");
2021 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2023 // Emit the pubnames for this compilation unit.
2024 for (const auto &GI : Globals) {
2025 const char *Name = GI.getKeyData();
2026 const DIE *Entity = GI.second;
2028 Asm->OutStreamer.AddComment("DIE offset");
2029 Asm->EmitInt32(Entity->getOffset());
2032 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2033 Asm->OutStreamer.AddComment(
2034 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2035 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2036 Asm->EmitInt8(Desc.toBits());
2039 Asm->OutStreamer.AddComment("External Name");
2040 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2043 Asm->OutStreamer.AddComment("End Mark");
2045 Asm->OutStreamer.EmitLabel(EndLabel);
2049 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2050 const MCSection *PSec =
2051 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2052 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2054 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2057 // Emit visible names into a debug str section.
2058 void DwarfDebug::emitDebugStr() {
2059 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2060 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2063 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2064 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2065 const DITypeIdentifierMap &Map,
2066 ArrayRef<DebugLocEntry::Value> Values) {
2067 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
2068 return P.isVariablePiece();
2069 }) && "all values are expected to be pieces");
2070 assert(std::is_sorted(Values.begin(), Values.end()) &&
2071 "pieces are expected to be sorted");
2073 unsigned Offset = 0;
2074 for (auto Piece : Values) {
2075 DIVariable Var = Piece.getVariable();
2076 unsigned PieceOffset = Var.getPieceOffset();
2077 unsigned PieceSize = Var.getPieceSize();
2078 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
2079 if (Offset < PieceOffset) {
2080 // The DWARF spec seriously mandates pieces with no locations for gaps.
2081 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2082 Offset += PieceOffset-Offset;
2085 Offset += PieceSize;
2087 const unsigned SizeOfByte = 8;
2088 assert(!Var.isIndirect() && "indirect address for piece");
2090 unsigned VarSize = Var.getSizeInBits(Map);
2091 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2092 && "piece is larger than or outside of variable");
2093 assert(PieceSize*SizeOfByte != VarSize
2094 && "piece covers entire variable");
2096 if (Piece.isLocation() && Piece.getLoc().isReg())
2097 Asm->EmitDwarfRegOpPiece(Streamer,
2099 PieceSize*SizeOfByte);
2101 emitDebugLocValue(Streamer, Piece);
2102 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2108 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2109 const DebugLocEntry &Entry) {
2110 const DebugLocEntry::Value Value = Entry.getValues()[0];
2111 if (Value.isVariablePiece())
2112 // Emit all pieces that belong to the same variable and range.
2113 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2115 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2116 emitDebugLocValue(Streamer, Value);
2119 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2120 const DebugLocEntry::Value &Value) {
2121 DIVariable DV = Value.getVariable();
2123 if (Value.isInt()) {
2124 DIBasicType BTy(resolve(DV.getType()));
2125 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2126 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2127 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2128 Streamer.EmitSLEB128(Value.getInt());
2130 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2131 Streamer.EmitULEB128(Value.getInt());
2133 } else if (Value.isLocation()) {
2134 MachineLocation Loc = Value.getLoc();
2135 if (!DV.hasComplexAddress())
2137 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2139 // Complex address entry.
2140 unsigned N = DV.getNumAddrElements();
2142 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2143 if (Loc.getOffset()) {
2145 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2146 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2147 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2148 Streamer.EmitSLEB128(DV.getAddrElement(1));
2150 // If first address element is OpPlus then emit
2151 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2152 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2153 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2157 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2160 // Emit remaining complex address elements.
2161 for (; i < N; ++i) {
2162 uint64_t Element = DV.getAddrElement(i);
2163 if (Element == DIBuilder::OpPlus) {
2164 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2165 Streamer.EmitULEB128(DV.getAddrElement(++i));
2166 } else if (Element == DIBuilder::OpDeref) {
2168 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2169 } else if (Element == DIBuilder::OpPiece) {
2171 // handled in emitDebugLocEntry.
2173 llvm_unreachable("unknown Opcode found in complex address");
2177 // else ... ignore constant fp. There is not any good way to
2178 // to represent them here in dwarf.
2182 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2183 Asm->OutStreamer.AddComment("Loc expr size");
2184 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2185 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2186 Asm->EmitLabelDifference(end, begin, 2);
2187 Asm->OutStreamer.EmitLabel(begin);
2189 APByteStreamer Streamer(*Asm);
2190 emitDebugLocEntry(Streamer, Entry);
2192 Asm->OutStreamer.EmitLabel(end);
2195 // Emit locations into the debug loc section.
2196 void DwarfDebug::emitDebugLoc() {
2197 // Start the dwarf loc section.
2198 Asm->OutStreamer.SwitchSection(
2199 Asm->getObjFileLowering().getDwarfLocSection());
2200 unsigned char Size = Asm->getDataLayout().getPointerSize();
2201 for (const auto &DebugLoc : DotDebugLocEntries) {
2202 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2203 const DwarfCompileUnit *CU = DebugLoc.CU;
2204 assert(!CU->getRanges().empty());
2205 for (const auto &Entry : DebugLoc.List) {
2206 // Set up the range. This range is relative to the entry point of the
2207 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2208 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2209 if (CU->getRanges().size() == 1) {
2210 // Grab the begin symbol from the first range as our base.
2211 const MCSymbol *Base = CU->getRanges()[0].getStart();
2212 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2213 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2215 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2216 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2219 emitDebugLocEntryLocation(Entry);
2221 Asm->OutStreamer.EmitIntValue(0, Size);
2222 Asm->OutStreamer.EmitIntValue(0, Size);
2226 void DwarfDebug::emitDebugLocDWO() {
2227 Asm->OutStreamer.SwitchSection(
2228 Asm->getObjFileLowering().getDwarfLocDWOSection());
2229 for (const auto &DebugLoc : DotDebugLocEntries) {
2230 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2231 for (const auto &Entry : DebugLoc.List) {
2232 // Just always use start_length for now - at least that's one address
2233 // rather than two. We could get fancier and try to, say, reuse an
2234 // address we know we've emitted elsewhere (the start of the function?
2235 // The start of the CU or CU subrange that encloses this range?)
2236 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2237 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2238 Asm->EmitULEB128(idx);
2239 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2241 emitDebugLocEntryLocation(Entry);
2243 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2248 const MCSymbol *Start, *End;
2251 // Emit a debug aranges section, containing a CU lookup for any
2252 // address we can tie back to a CU.
2253 void DwarfDebug::emitDebugARanges() {
2254 // Start the dwarf aranges section.
2255 Asm->OutStreamer.SwitchSection(
2256 Asm->getObjFileLowering().getDwarfARangesSection());
2258 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2262 // Build a list of sections used.
2263 std::vector<const MCSection *> Sections;
2264 for (const auto &it : SectionMap) {
2265 const MCSection *Section = it.first;
2266 Sections.push_back(Section);
2269 // Sort the sections into order.
2270 // This is only done to ensure consistent output order across different runs.
2271 std::sort(Sections.begin(), Sections.end(), SectionSort);
2273 // Build a set of address spans, sorted by CU.
2274 for (const MCSection *Section : Sections) {
2275 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2276 if (List.size() < 2)
2279 // Sort the symbols by offset within the section.
2280 std::sort(List.begin(), List.end(),
2281 [&](const SymbolCU &A, const SymbolCU &B) {
2282 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2283 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2285 // Symbols with no order assigned should be placed at the end.
2286 // (e.g. section end labels)
2294 // If we have no section (e.g. common), just write out
2295 // individual spans for each symbol.
2297 for (const SymbolCU &Cur : List) {
2299 Span.Start = Cur.Sym;
2302 Spans[Cur.CU].push_back(Span);
2305 // Build spans between each label.
2306 const MCSymbol *StartSym = List[0].Sym;
2307 for (size_t n = 1, e = List.size(); n < e; n++) {
2308 const SymbolCU &Prev = List[n - 1];
2309 const SymbolCU &Cur = List[n];
2311 // Try and build the longest span we can within the same CU.
2312 if (Cur.CU != Prev.CU) {
2314 Span.Start = StartSym;
2316 Spans[Prev.CU].push_back(Span);
2323 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2325 // Build a list of CUs used.
2326 std::vector<DwarfCompileUnit *> CUs;
2327 for (const auto &it : Spans) {
2328 DwarfCompileUnit *CU = it.first;
2332 // Sort the CU list (again, to ensure consistent output order).
2333 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2334 return A->getUniqueID() < B->getUniqueID();
2337 // Emit an arange table for each CU we used.
2338 for (DwarfCompileUnit *CU : CUs) {
2339 std::vector<ArangeSpan> &List = Spans[CU];
2341 // Emit size of content not including length itself.
2342 unsigned ContentSize =
2343 sizeof(int16_t) + // DWARF ARange version number
2344 sizeof(int32_t) + // Offset of CU in the .debug_info section
2345 sizeof(int8_t) + // Pointer Size (in bytes)
2346 sizeof(int8_t); // Segment Size (in bytes)
2348 unsigned TupleSize = PtrSize * 2;
2350 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2352 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2354 ContentSize += Padding;
2355 ContentSize += (List.size() + 1) * TupleSize;
2357 // For each compile unit, write the list of spans it covers.
2358 Asm->OutStreamer.AddComment("Length of ARange Set");
2359 Asm->EmitInt32(ContentSize);
2360 Asm->OutStreamer.AddComment("DWARF Arange version number");
2361 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2362 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2363 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2364 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2365 Asm->EmitInt8(PtrSize);
2366 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2369 Asm->OutStreamer.EmitFill(Padding, 0xff);
2371 for (const ArangeSpan &Span : List) {
2372 Asm->EmitLabelReference(Span.Start, PtrSize);
2374 // Calculate the size as being from the span start to it's end.
2376 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2378 // For symbols without an end marker (e.g. common), we
2379 // write a single arange entry containing just that one symbol.
2380 uint64_t Size = SymSize[Span.Start];
2384 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2388 Asm->OutStreamer.AddComment("ARange terminator");
2389 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2390 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2394 // Emit visible names into a debug ranges section.
2395 void DwarfDebug::emitDebugRanges() {
2396 // Start the dwarf ranges section.
2397 Asm->OutStreamer.SwitchSection(
2398 Asm->getObjFileLowering().getDwarfRangesSection());
2400 // Size for our labels.
2401 unsigned char Size = Asm->getDataLayout().getPointerSize();
2403 // Grab the specific ranges for the compile units in the module.
2404 for (const auto &I : CUMap) {
2405 DwarfCompileUnit *TheCU = I.second;
2407 // Iterate over the misc ranges for the compile units in the module.
2408 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2409 // Emit our symbol so we can find the beginning of the range.
2410 Asm->OutStreamer.EmitLabel(List.getSym());
2412 for (const RangeSpan &Range : List.getRanges()) {
2413 const MCSymbol *Begin = Range.getStart();
2414 const MCSymbol *End = Range.getEnd();
2415 assert(Begin && "Range without a begin symbol?");
2416 assert(End && "Range without an end symbol?");
2417 if (TheCU->getRanges().size() == 1) {
2418 // Grab the begin symbol from the first range as our base.
2419 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2420 Asm->EmitLabelDifference(Begin, Base, Size);
2421 Asm->EmitLabelDifference(End, Base, Size);
2423 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2424 Asm->OutStreamer.EmitSymbolValue(End, Size);
2428 // And terminate the list with two 0 values.
2429 Asm->OutStreamer.EmitIntValue(0, Size);
2430 Asm->OutStreamer.EmitIntValue(0, Size);
2433 // Now emit a range for the CU itself.
2434 if (TheCU->getRanges().size() > 1) {
2435 Asm->OutStreamer.EmitLabel(
2436 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2437 for (const RangeSpan &Range : TheCU->getRanges()) {
2438 const MCSymbol *Begin = Range.getStart();
2439 const MCSymbol *End = Range.getEnd();
2440 assert(Begin && "Range without a begin symbol?");
2441 assert(End && "Range without an end symbol?");
2442 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2443 Asm->OutStreamer.EmitSymbolValue(End, Size);
2445 // And terminate the list with two 0 values.
2446 Asm->OutStreamer.EmitIntValue(0, Size);
2447 Asm->OutStreamer.EmitIntValue(0, Size);
2452 // DWARF5 Experimental Separate Dwarf emitters.
2454 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2455 std::unique_ptr<DwarfUnit> NewU) {
2456 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2457 U.getCUNode().getSplitDebugFilename());
2459 if (!CompilationDir.empty())
2460 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2462 addGnuPubAttributes(*NewU, Die);
2464 SkeletonHolder.addUnit(std::move(NewU));
2467 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2468 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2469 // DW_AT_addr_base, DW_AT_ranges_base.
2470 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2472 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2473 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2474 DwarfCompileUnit &NewCU = *OwnedUnit;
2475 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2476 DwarfInfoSectionSym);
2478 NewCU.initStmtList(DwarfLineSectionSym);
2480 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2485 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2487 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2488 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2489 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2491 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2493 DwarfTypeUnit &NewTU = *OwnedUnit;
2494 NewTU.setTypeSignature(TU.getTypeSignature());
2495 NewTU.setType(nullptr);
2497 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2499 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2503 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2504 // compile units that would normally be in debug_info.
2505 void DwarfDebug::emitDebugInfoDWO() {
2506 assert(useSplitDwarf() && "No split dwarf debug info?");
2507 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2508 // emit relocations into the dwo file.
2509 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2512 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2513 // abbreviations for the .debug_info.dwo section.
2514 void DwarfDebug::emitDebugAbbrevDWO() {
2515 assert(useSplitDwarf() && "No split dwarf?");
2516 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2519 void DwarfDebug::emitDebugLineDWO() {
2520 assert(useSplitDwarf() && "No split dwarf?");
2521 Asm->OutStreamer.SwitchSection(
2522 Asm->getObjFileLowering().getDwarfLineDWOSection());
2523 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2526 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2527 // string section and is identical in format to traditional .debug_str
2529 void DwarfDebug::emitDebugStrDWO() {
2530 assert(useSplitDwarf() && "No split dwarf?");
2531 const MCSection *OffSec =
2532 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2533 const MCSymbol *StrSym = DwarfStrSectionSym;
2534 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2538 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2539 if (!useSplitDwarf())
2542 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2543 return &SplitTypeUnitFileTable;
2546 static uint64_t makeTypeSignature(StringRef Identifier) {
2548 Hash.update(Identifier);
2549 // ... take the least significant 8 bytes and return those. Our MD5
2550 // implementation always returns its results in little endian, swap bytes
2552 MD5::MD5Result Result;
2554 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2557 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2558 StringRef Identifier, DIE &RefDie,
2559 DICompositeType CTy) {
2560 // Fast path if we're building some type units and one has already used the
2561 // address pool we know we're going to throw away all this work anyway, so
2562 // don't bother building dependent types.
2563 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2566 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2568 CU.addDIETypeSignature(RefDie, *TU);
2572 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2573 AddrPool.resetUsedFlag();
2575 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2576 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2577 this, &InfoHolder, getDwoLineTable(CU));
2578 DwarfTypeUnit &NewTU = *OwnedUnit;
2579 DIE &UnitDie = NewTU.getUnitDie();
2581 TypeUnitsUnderConstruction.push_back(
2582 std::make_pair(std::move(OwnedUnit), CTy));
2584 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2587 uint64_t Signature = makeTypeSignature(Identifier);
2588 NewTU.setTypeSignature(Signature);
2590 if (useSplitDwarf())
2591 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2592 DwarfTypesDWOSectionSym);
2594 CU.applyStmtList(UnitDie);
2596 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2599 NewTU.setType(NewTU.createTypeDIE(CTy));
2602 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2603 TypeUnitsUnderConstruction.clear();
2605 // Types referencing entries in the address table cannot be placed in type
2607 if (AddrPool.hasBeenUsed()) {
2609 // Remove all the types built while building this type.
2610 // This is pessimistic as some of these types might not be dependent on
2611 // the type that used an address.
2612 for (const auto &TU : TypeUnitsToAdd)
2613 DwarfTypeUnits.erase(TU.second);
2615 // Construct this type in the CU directly.
2616 // This is inefficient because all the dependent types will be rebuilt
2617 // from scratch, including building them in type units, discovering that
2618 // they depend on addresses, throwing them out and rebuilding them.
2619 CU.constructTypeDIE(RefDie, CTy);
2623 // If the type wasn't dependent on fission addresses, finish adding the type
2624 // and all its dependent types.
2625 for (auto &TU : TypeUnitsToAdd) {
2626 if (useSplitDwarf())
2627 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2628 InfoHolder.addUnit(std::move(TU.first));
2631 CU.addDIETypeSignature(RefDie, NewTU);
2634 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2635 MCSymbol *Begin, MCSymbol *End) {
2636 assert(Begin && "Begin label should not be null!");
2637 assert(End && "End label should not be null!");
2638 assert(Begin->isDefined() && "Invalid starting label");
2639 assert(End->isDefined() && "Invalid end label");
2641 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2642 if (DwarfVersion < 4)
2643 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2645 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2648 // Accelerator table mutators - add each name along with its companion
2649 // DIE to the proper table while ensuring that the name that we're going
2650 // to reference is in the string table. We do this since the names we
2651 // add may not only be identical to the names in the DIE.
2652 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2653 if (!useDwarfAccelTables())
2655 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2659 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2660 if (!useDwarfAccelTables())
2662 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2666 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2667 if (!useDwarfAccelTables())
2669 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2673 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2674 if (!useDwarfAccelTables())
2676 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),