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 (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1313 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1314 Scope = LScopes.getCurrentFunctionScope();
1315 else if (MDNode *IA = DV.getInlinedAt()) {
1316 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1317 Scope = LScopes.findInlinedScope(DebugLoc::get(
1318 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1320 Scope = LScopes.findLexicalScope(DV.getContext());
1321 // If variable scope is not found then skip this variable.
1325 Processed.insert(getEntireVariable(DV));
1326 const MachineInstr *MInsn = Ranges.front().first;
1327 assert(MInsn->isDebugValue() && "History must begin with debug value");
1328 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1329 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1330 DbgVariable *RegVar = ConcreteVariables.back().get();
1331 addScopeVariable(Scope, RegVar);
1333 // Check if the first DBG_VALUE is valid for the rest of the function.
1334 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1337 // Handle multiple DBG_VALUE instructions describing one variable.
1338 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1340 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1341 DebugLocList &LocList = DotDebugLocEntries.back();
1344 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1346 // Build the location list for this variable.
1347 buildLocationList(LocList.List, Ranges);
1350 // Collect info for variables that were optimized out.
1351 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1352 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1353 DIVariable DV(Variables.getElement(i));
1354 assert(DV.isVariable());
1355 if (!Processed.insert(DV))
1357 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1358 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1359 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1360 addScopeVariable(Scope, ConcreteVariables.back().get());
1365 // Return Label preceding the instruction.
1366 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1367 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1368 assert(Label && "Didn't insert label before instruction");
1372 // Return Label immediately following the instruction.
1373 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1374 return LabelsAfterInsn.lookup(MI);
1377 // Process beginning of an instruction.
1378 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1379 assert(CurMI == nullptr);
1381 // Check if source location changes, but ignore DBG_VALUE locations.
1382 if (!MI->isDebugValue()) {
1383 DebugLoc DL = MI->getDebugLoc();
1384 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1387 if (DL == PrologEndLoc) {
1388 Flags |= DWARF2_FLAG_PROLOGUE_END;
1389 PrologEndLoc = DebugLoc();
1391 if (PrologEndLoc.isUnknown())
1392 Flags |= DWARF2_FLAG_IS_STMT;
1394 if (!DL.isUnknown()) {
1395 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1396 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1398 recordSourceLine(0, 0, nullptr, 0);
1402 // Insert labels where requested.
1403 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1404 LabelsBeforeInsn.find(MI);
1407 if (I == LabelsBeforeInsn.end())
1410 // Label already assigned.
1415 PrevLabel = MMI->getContext().CreateTempSymbol();
1416 Asm->OutStreamer.EmitLabel(PrevLabel);
1418 I->second = PrevLabel;
1421 // Process end of an instruction.
1422 void DwarfDebug::endInstruction() {
1423 assert(CurMI != nullptr);
1424 // Don't create a new label after DBG_VALUE instructions.
1425 // They don't generate code.
1426 if (!CurMI->isDebugValue())
1427 PrevLabel = nullptr;
1429 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1430 LabelsAfterInsn.find(CurMI);
1434 if (I == LabelsAfterInsn.end())
1437 // Label already assigned.
1441 // We need a label after this instruction.
1443 PrevLabel = MMI->getContext().CreateTempSymbol();
1444 Asm->OutStreamer.EmitLabel(PrevLabel);
1446 I->second = PrevLabel;
1449 // Each LexicalScope has first instruction and last instruction to mark
1450 // beginning and end of a scope respectively. Create an inverse map that list
1451 // scopes starts (and ends) with an instruction. One instruction may start (or
1452 // end) multiple scopes. Ignore scopes that are not reachable.
1453 void DwarfDebug::identifyScopeMarkers() {
1454 SmallVector<LexicalScope *, 4> WorkList;
1455 WorkList.push_back(LScopes.getCurrentFunctionScope());
1456 while (!WorkList.empty()) {
1457 LexicalScope *S = WorkList.pop_back_val();
1459 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1460 if (!Children.empty())
1461 WorkList.append(Children.begin(), Children.end());
1463 if (S->isAbstractScope())
1466 for (const InsnRange &R : S->getRanges()) {
1467 assert(R.first && "InsnRange does not have first instruction!");
1468 assert(R.second && "InsnRange does not have second instruction!");
1469 requestLabelBeforeInsn(R.first);
1470 requestLabelAfterInsn(R.second);
1475 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1476 // First known non-DBG_VALUE and non-frame setup location marks
1477 // the beginning of the function body.
1478 for (const auto &MBB : *MF)
1479 for (const auto &MI : MBB)
1480 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1481 !MI.getDebugLoc().isUnknown())
1482 return MI.getDebugLoc();
1486 // Gather pre-function debug information. Assumes being called immediately
1487 // after the function entry point has been emitted.
1488 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1491 // If there's no debug info for the function we're not going to do anything.
1492 if (!MMI->hasDebugInfo())
1495 auto DI = FunctionDIs.find(MF->getFunction());
1496 if (DI == FunctionDIs.end())
1499 // Grab the lexical scopes for the function, if we don't have any of those
1500 // then we're not going to be able to do anything.
1501 LScopes.initialize(*MF);
1502 if (LScopes.empty())
1505 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1507 // Make sure that each lexical scope will have a begin/end label.
1508 identifyScopeMarkers();
1510 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1511 // belongs to so that we add to the correct per-cu line table in the
1513 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1514 // FnScope->getScopeNode() and DI->second should represent the same function,
1515 // though they may not be the same MDNode due to inline functions merged in
1516 // LTO where the debug info metadata still differs (either due to distinct
1517 // written differences - two versions of a linkonce_odr function
1518 // written/copied into two separate files, or some sub-optimal metadata that
1519 // isn't structurally identical (see: file path/name info from clang, which
1520 // includes the directory of the cpp file being built, even when the file name
1521 // is absolute (such as an <> lookup header)))
1522 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1523 assert(TheCU && "Unable to find compile unit!");
1524 if (Asm->OutStreamer.hasRawTextSupport())
1525 // Use a single line table if we are generating assembly.
1526 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1528 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1530 // Emit a label for the function so that we have a beginning address.
1531 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1532 // Assumes in correct section after the entry point.
1533 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1535 // Calculate history for local variables.
1536 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1539 // Request labels for the full history.
1540 for (const auto &I : DbgValues) {
1541 const auto &Ranges = I.second;
1545 // The first mention of a function argument gets the FunctionBeginSym
1546 // label, so arguments are visible when breaking at function entry.
1547 DIVariable DV(Ranges.front().first->getDebugVariable());
1548 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1549 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1550 if (!DV.isVariablePiece())
1551 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1553 // Mark all non-overlapping initial pieces.
1554 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1555 DIVariable Piece = I->first->getDebugVariable();
1556 if (std::all_of(Ranges.begin(), I,
1557 [&](DbgValueHistoryMap::InstrRange Pred){
1558 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1560 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1567 for (const auto &Range : Ranges) {
1568 requestLabelBeforeInsn(Range.first);
1570 requestLabelAfterInsn(Range.second);
1574 PrevInstLoc = DebugLoc();
1575 PrevLabel = FunctionBeginSym;
1577 // Record beginning of function.
1578 PrologEndLoc = findPrologueEndLoc(MF);
1579 if (!PrologEndLoc.isUnknown()) {
1580 DebugLoc FnStartDL =
1581 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1583 FnStartDL.getLine(), FnStartDL.getCol(),
1584 FnStartDL.getScope(MF->getFunction()->getContext()),
1585 // We'd like to list the prologue as "not statements" but GDB behaves
1586 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1587 DWARF2_FLAG_IS_STMT);
1591 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1592 if (addCurrentFnArgument(Var, LS))
1594 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1595 DIVariable DV = Var->getVariable();
1596 // Variables with positive arg numbers are parameters.
1597 if (unsigned ArgNum = DV.getArgNumber()) {
1598 // Keep all parameters in order at the start of the variable list to ensure
1599 // function types are correct (no out-of-order parameters)
1601 // This could be improved by only doing it for optimized builds (unoptimized
1602 // builds have the right order to begin with), searching from the back (this
1603 // would catch the unoptimized case quickly), or doing a binary search
1604 // rather than linear search.
1605 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1606 while (I != Vars.end()) {
1607 unsigned CurNum = (*I)->getVariable().getArgNumber();
1608 // A local (non-parameter) variable has been found, insert immediately
1612 // A later indexed parameter has been found, insert immediately before it.
1613 if (CurNum > ArgNum)
1617 Vars.insert(I, Var);
1621 Vars.push_back(Var);
1624 // Gather and emit post-function debug information.
1625 void DwarfDebug::endFunction(const MachineFunction *MF) {
1626 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1627 // though the beginFunction may not be called at all.
1628 // We should handle both cases.
1632 assert(CurFn == MF);
1633 assert(CurFn != nullptr);
1635 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1636 !FunctionDIs.count(MF->getFunction())) {
1637 // If we don't have a lexical scope for this function then there will
1638 // be a hole in the range information. Keep note of this by setting the
1639 // previously used section to nullptr.
1640 PrevSection = nullptr;
1646 // Define end label for subprogram.
1647 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1648 // Assumes in correct section after the entry point.
1649 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1651 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1652 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1654 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1655 collectVariableInfo(ProcessedVars);
1657 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1658 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1660 // Construct abstract scopes.
1661 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1662 DISubprogram SP(AScope->getScopeNode());
1663 assert(SP.isSubprogram());
1664 // Collect info for variables that were optimized out.
1665 DIArray Variables = SP.getVariables();
1666 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1667 DIVariable DV(Variables.getElement(i));
1668 assert(DV && DV.isVariable());
1669 if (!ProcessedVars.insert(DV))
1671 ensureAbstractVariableIsCreated(DV, DV.getContext());
1673 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1676 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1677 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1678 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1680 // Add the range of this function to the list of ranges for the CU.
1681 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1682 TheCU.addRange(std::move(Span));
1683 PrevSection = Asm->getCurrentSection();
1687 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1688 // DbgVariables except those that are also in AbstractVariables (since they
1689 // can be used cross-function)
1690 ScopeVariables.clear();
1691 CurrentFnArguments.clear();
1693 LabelsBeforeInsn.clear();
1694 LabelsAfterInsn.clear();
1695 PrevLabel = nullptr;
1699 // Register a source line with debug info. Returns the unique label that was
1700 // emitted and which provides correspondence to the source line list.
1701 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1706 unsigned Discriminator = 0;
1707 if (DIScope Scope = DIScope(S)) {
1708 assert(Scope.isScope());
1709 Fn = Scope.getFilename();
1710 Dir = Scope.getDirectory();
1711 if (Scope.isLexicalBlock())
1712 Discriminator = DILexicalBlock(S).getDiscriminator();
1714 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1715 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1716 .getOrCreateSourceID(Fn, Dir);
1718 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1722 //===----------------------------------------------------------------------===//
1724 //===----------------------------------------------------------------------===//
1726 // Emit initial Dwarf sections with a label at the start of each one.
1727 void DwarfDebug::emitSectionLabels() {
1728 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1730 // Dwarf sections base addresses.
1731 DwarfInfoSectionSym =
1732 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1733 if (useSplitDwarf()) {
1734 DwarfInfoDWOSectionSym =
1735 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1736 DwarfTypesDWOSectionSym =
1737 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1739 DwarfAbbrevSectionSym =
1740 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1741 if (useSplitDwarf())
1742 DwarfAbbrevDWOSectionSym = emitSectionSym(
1743 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1744 if (GenerateARangeSection)
1745 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1747 DwarfLineSectionSym =
1748 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1749 if (GenerateGnuPubSections) {
1750 DwarfGnuPubNamesSectionSym =
1751 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1752 DwarfGnuPubTypesSectionSym =
1753 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1754 } else if (HasDwarfPubSections) {
1755 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1756 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1759 DwarfStrSectionSym =
1760 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1761 if (useSplitDwarf()) {
1762 DwarfStrDWOSectionSym =
1763 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1764 DwarfAddrSectionSym =
1765 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1766 DwarfDebugLocSectionSym =
1767 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1769 DwarfDebugLocSectionSym =
1770 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1771 DwarfDebugRangeSectionSym =
1772 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1775 // Recursively emits a debug information entry.
1776 void DwarfDebug::emitDIE(DIE &Die) {
1777 // Get the abbreviation for this DIE.
1778 const DIEAbbrev &Abbrev = Die.getAbbrev();
1780 // Emit the code (index) for the abbreviation.
1781 if (Asm->isVerbose())
1782 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1783 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1784 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1785 dwarf::TagString(Abbrev.getTag()));
1786 Asm->EmitULEB128(Abbrev.getNumber());
1788 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1789 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1791 // Emit the DIE attribute values.
1792 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1793 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1794 dwarf::Form Form = AbbrevData[i].getForm();
1795 assert(Form && "Too many attributes for DIE (check abbreviation)");
1797 if (Asm->isVerbose()) {
1798 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1799 if (Attr == dwarf::DW_AT_accessibility)
1800 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1801 cast<DIEInteger>(Values[i])->getValue()));
1804 // Emit an attribute using the defined form.
1805 Values[i]->EmitValue(Asm, Form);
1808 // Emit the DIE children if any.
1809 if (Abbrev.hasChildren()) {
1810 for (auto &Child : Die.getChildren())
1813 Asm->OutStreamer.AddComment("End Of Children Mark");
1818 // Emit the debug info section.
1819 void DwarfDebug::emitDebugInfo() {
1820 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1822 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1825 // Emit the abbreviation section.
1826 void DwarfDebug::emitAbbreviations() {
1827 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1829 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1832 // Emit the last address of the section and the end of the line matrix.
1833 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1834 // Define last address of section.
1835 Asm->OutStreamer.AddComment("Extended Op");
1838 Asm->OutStreamer.AddComment("Op size");
1839 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1840 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1841 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1843 Asm->OutStreamer.AddComment("Section end label");
1845 Asm->OutStreamer.EmitSymbolValue(
1846 Asm->GetTempSymbol("section_end", SectionEnd),
1847 Asm->getDataLayout().getPointerSize());
1849 // Mark end of matrix.
1850 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1856 // Emit visible names into a hashed accelerator table section.
1857 void DwarfDebug::emitAccelNames() {
1858 AccelNames.FinalizeTable(Asm, "Names");
1859 Asm->OutStreamer.SwitchSection(
1860 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1861 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1862 Asm->OutStreamer.EmitLabel(SectionBegin);
1864 // Emit the full data.
1865 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1868 // Emit objective C classes and categories into a hashed accelerator table
1870 void DwarfDebug::emitAccelObjC() {
1871 AccelObjC.FinalizeTable(Asm, "ObjC");
1872 Asm->OutStreamer.SwitchSection(
1873 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1874 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1875 Asm->OutStreamer.EmitLabel(SectionBegin);
1877 // Emit the full data.
1878 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1881 // Emit namespace dies into a hashed accelerator table.
1882 void DwarfDebug::emitAccelNamespaces() {
1883 AccelNamespace.FinalizeTable(Asm, "namespac");
1884 Asm->OutStreamer.SwitchSection(
1885 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1886 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1887 Asm->OutStreamer.EmitLabel(SectionBegin);
1889 // Emit the full data.
1890 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1893 // Emit type dies into a hashed accelerator table.
1894 void DwarfDebug::emitAccelTypes() {
1896 AccelTypes.FinalizeTable(Asm, "types");
1897 Asm->OutStreamer.SwitchSection(
1898 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1899 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1900 Asm->OutStreamer.EmitLabel(SectionBegin);
1902 // Emit the full data.
1903 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1906 // Public name handling.
1907 // The format for the various pubnames:
1909 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1910 // for the DIE that is named.
1912 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1913 // into the CU and the index value is computed according to the type of value
1914 // for the DIE that is named.
1916 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1917 // it's the offset within the debug_info/debug_types dwo section, however, the
1918 // reference in the pubname header doesn't change.
1920 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1921 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1923 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1925 // We could have a specification DIE that has our most of our knowledge,
1926 // look for that now.
1927 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1929 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1930 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1931 Linkage = dwarf::GIEL_EXTERNAL;
1932 } else if (Die->findAttribute(dwarf::DW_AT_external))
1933 Linkage = dwarf::GIEL_EXTERNAL;
1935 switch (Die->getTag()) {
1936 case dwarf::DW_TAG_class_type:
1937 case dwarf::DW_TAG_structure_type:
1938 case dwarf::DW_TAG_union_type:
1939 case dwarf::DW_TAG_enumeration_type:
1940 return dwarf::PubIndexEntryDescriptor(
1941 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1942 ? dwarf::GIEL_STATIC
1943 : dwarf::GIEL_EXTERNAL);
1944 case dwarf::DW_TAG_typedef:
1945 case dwarf::DW_TAG_base_type:
1946 case dwarf::DW_TAG_subrange_type:
1947 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1948 case dwarf::DW_TAG_namespace:
1949 return dwarf::GIEK_TYPE;
1950 case dwarf::DW_TAG_subprogram:
1951 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1952 case dwarf::DW_TAG_constant:
1953 case dwarf::DW_TAG_variable:
1954 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1955 case dwarf::DW_TAG_enumerator:
1956 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1957 dwarf::GIEL_STATIC);
1959 return dwarf::GIEK_NONE;
1963 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1965 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1966 const MCSection *PSec =
1967 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1968 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1970 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1973 void DwarfDebug::emitDebugPubSection(
1974 bool GnuStyle, const MCSection *PSec, StringRef Name,
1975 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1976 for (const auto &NU : CUMap) {
1977 DwarfCompileUnit *TheU = NU.second;
1979 const auto &Globals = (TheU->*Accessor)();
1981 if (Globals.empty())
1984 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1986 unsigned ID = TheU->getUniqueID();
1988 // Start the dwarf pubnames section.
1989 Asm->OutStreamer.SwitchSection(PSec);
1992 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1993 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
1994 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
1995 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1997 Asm->OutStreamer.EmitLabel(BeginLabel);
1999 Asm->OutStreamer.AddComment("DWARF Version");
2000 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2002 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2003 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2005 Asm->OutStreamer.AddComment("Compilation Unit Length");
2006 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2008 // Emit the pubnames for this compilation unit.
2009 for (const auto &GI : Globals) {
2010 const char *Name = GI.getKeyData();
2011 const DIE *Entity = GI.second;
2013 Asm->OutStreamer.AddComment("DIE offset");
2014 Asm->EmitInt32(Entity->getOffset());
2017 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2018 Asm->OutStreamer.AddComment(
2019 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2020 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2021 Asm->EmitInt8(Desc.toBits());
2024 Asm->OutStreamer.AddComment("External Name");
2025 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2028 Asm->OutStreamer.AddComment("End Mark");
2030 Asm->OutStreamer.EmitLabel(EndLabel);
2034 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2035 const MCSection *PSec =
2036 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2037 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2039 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2042 // Emit visible names into a debug str section.
2043 void DwarfDebug::emitDebugStr() {
2044 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2045 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2048 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2049 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2050 const DITypeIdentifierMap &Map,
2051 ArrayRef<DebugLocEntry::Value> Values) {
2052 typedef DebugLocEntry::Value Piece;
2053 SmallVector<Piece, 4> Pieces(Values.begin(), Values.end());
2054 assert(std::all_of(Pieces.begin(), Pieces.end(), [](Piece &P) {
2055 return DIVariable(P.getVariable()).isVariablePiece();
2056 }) && "all values are expected to be pieces");
2058 // Sort the pieces so they can be emitted using DW_OP_piece.
2059 std::sort(Pieces.begin(), Pieces.end(), [](const Piece &A, const Piece &B) {
2060 DIVariable VarA(A.getVariable());
2061 DIVariable VarB(B.getVariable());
2062 return VarA.getPieceOffset() < VarB.getPieceOffset();
2064 // Remove any duplicate entries by dropping all but the first.
2065 Pieces.erase(std::unique(Pieces.begin(), Pieces.end(),
2066 [] (const Piece &A,const Piece &B){
2067 return A.getVariable() == B.getVariable();
2070 unsigned Offset = 0;
2071 for (auto Piece : Pieces) {
2072 DIVariable Var(Piece.getVariable());
2073 unsigned PieceOffset = Var.getPieceOffset();
2074 unsigned PieceSize = Var.getPieceSize();
2075 assert(Offset <= PieceOffset && "overlapping pieces in DebugLocEntry");
2076 if (Offset < PieceOffset) {
2077 // The DWARF spec seriously mandates pieces with no locations for gaps.
2078 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2079 Offset += PieceOffset-Offset;
2082 Offset += PieceSize;
2084 const unsigned SizeOfByte = 8;
2085 assert(!Var.isIndirect() && "indirect address for piece");
2087 unsigned VarSize = Var.getSizeInBits(Map);
2088 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2089 && "piece is larger than or outside of variable");
2090 assert(PieceSize*SizeOfByte != VarSize
2091 && "piece covers entire variable");
2093 if (Piece.isLocation() && Piece.getLoc().isReg())
2094 Asm->EmitDwarfRegOpPiece(Streamer,
2096 PieceSize*SizeOfByte);
2098 emitDebugLocValue(Streamer, Piece);
2099 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2105 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2106 const DebugLocEntry &Entry) {
2107 const DebugLocEntry::Value Value = Entry.getValues()[0];
2108 DIVariable DV(Value.getVariable());
2109 if (DV.isVariablePiece())
2110 // Emit all pieces that belong to the same variable and range.
2111 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2113 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2114 emitDebugLocValue(Streamer, Value);
2117 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2118 const DebugLocEntry::Value &Value) {
2119 DIVariable DV(Value.getVariable());
2121 if (Value.isInt()) {
2122 DIBasicType BTy(resolve(DV.getType()));
2123 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2124 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2125 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2126 Streamer.EmitSLEB128(Value.getInt());
2128 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2129 Streamer.EmitULEB128(Value.getInt());
2131 } else if (Value.isLocation()) {
2132 MachineLocation Loc = Value.getLoc();
2133 if (!DV.hasComplexAddress())
2135 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2137 // Complex address entry.
2138 unsigned N = DV.getNumAddrElements();
2140 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2141 if (Loc.getOffset()) {
2143 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2144 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2145 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2146 Streamer.EmitSLEB128(DV.getAddrElement(1));
2148 // If first address element is OpPlus then emit
2149 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2150 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2151 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2155 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2158 // Emit remaining complex address elements.
2159 for (; i < N; ++i) {
2160 uint64_t Element = DV.getAddrElement(i);
2161 if (Element == DIBuilder::OpPlus) {
2162 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2163 Streamer.EmitULEB128(DV.getAddrElement(++i));
2164 } else if (Element == DIBuilder::OpDeref) {
2166 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2167 } else if (Element == DIBuilder::OpPiece) {
2169 // handled in emitDebugLocEntry.
2171 llvm_unreachable("unknown Opcode found in complex address");
2175 // else ... ignore constant fp. There is not any good way to
2176 // to represent them here in dwarf.
2180 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2181 Asm->OutStreamer.AddComment("Loc expr size");
2182 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2183 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2184 Asm->EmitLabelDifference(end, begin, 2);
2185 Asm->OutStreamer.EmitLabel(begin);
2187 APByteStreamer Streamer(*Asm);
2188 emitDebugLocEntry(Streamer, Entry);
2190 Asm->OutStreamer.EmitLabel(end);
2193 // Emit locations into the debug loc section.
2194 void DwarfDebug::emitDebugLoc() {
2195 // Start the dwarf loc section.
2196 Asm->OutStreamer.SwitchSection(
2197 Asm->getObjFileLowering().getDwarfLocSection());
2198 unsigned char Size = Asm->getDataLayout().getPointerSize();
2199 for (const auto &DebugLoc : DotDebugLocEntries) {
2200 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2201 const DwarfCompileUnit *CU = DebugLoc.CU;
2202 assert(!CU->getRanges().empty());
2203 for (const auto &Entry : DebugLoc.List) {
2204 // Set up the range. This range is relative to the entry point of the
2205 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2206 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2207 if (CU->getRanges().size() == 1) {
2208 // Grab the begin symbol from the first range as our base.
2209 const MCSymbol *Base = CU->getRanges()[0].getStart();
2210 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2211 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2213 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2214 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2217 emitDebugLocEntryLocation(Entry);
2219 Asm->OutStreamer.EmitIntValue(0, Size);
2220 Asm->OutStreamer.EmitIntValue(0, Size);
2224 void DwarfDebug::emitDebugLocDWO() {
2225 Asm->OutStreamer.SwitchSection(
2226 Asm->getObjFileLowering().getDwarfLocDWOSection());
2227 for (const auto &DebugLoc : DotDebugLocEntries) {
2228 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2229 for (const auto &Entry : DebugLoc.List) {
2230 // Just always use start_length for now - at least that's one address
2231 // rather than two. We could get fancier and try to, say, reuse an
2232 // address we know we've emitted elsewhere (the start of the function?
2233 // The start of the CU or CU subrange that encloses this range?)
2234 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2235 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2236 Asm->EmitULEB128(idx);
2237 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2239 emitDebugLocEntryLocation(Entry);
2241 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2246 const MCSymbol *Start, *End;
2249 // Emit a debug aranges section, containing a CU lookup for any
2250 // address we can tie back to a CU.
2251 void DwarfDebug::emitDebugARanges() {
2252 // Start the dwarf aranges section.
2253 Asm->OutStreamer.SwitchSection(
2254 Asm->getObjFileLowering().getDwarfARangesSection());
2256 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2260 // Build a list of sections used.
2261 std::vector<const MCSection *> Sections;
2262 for (const auto &it : SectionMap) {
2263 const MCSection *Section = it.first;
2264 Sections.push_back(Section);
2267 // Sort the sections into order.
2268 // This is only done to ensure consistent output order across different runs.
2269 std::sort(Sections.begin(), Sections.end(), SectionSort);
2271 // Build a set of address spans, sorted by CU.
2272 for (const MCSection *Section : Sections) {
2273 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2274 if (List.size() < 2)
2277 // Sort the symbols by offset within the section.
2278 std::sort(List.begin(), List.end(),
2279 [&](const SymbolCU &A, const SymbolCU &B) {
2280 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2281 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2283 // Symbols with no order assigned should be placed at the end.
2284 // (e.g. section end labels)
2292 // If we have no section (e.g. common), just write out
2293 // individual spans for each symbol.
2295 for (const SymbolCU &Cur : List) {
2297 Span.Start = Cur.Sym;
2300 Spans[Cur.CU].push_back(Span);
2303 // Build spans between each label.
2304 const MCSymbol *StartSym = List[0].Sym;
2305 for (size_t n = 1, e = List.size(); n < e; n++) {
2306 const SymbolCU &Prev = List[n - 1];
2307 const SymbolCU &Cur = List[n];
2309 // Try and build the longest span we can within the same CU.
2310 if (Cur.CU != Prev.CU) {
2312 Span.Start = StartSym;
2314 Spans[Prev.CU].push_back(Span);
2321 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2323 // Build a list of CUs used.
2324 std::vector<DwarfCompileUnit *> CUs;
2325 for (const auto &it : Spans) {
2326 DwarfCompileUnit *CU = it.first;
2330 // Sort the CU list (again, to ensure consistent output order).
2331 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2332 return A->getUniqueID() < B->getUniqueID();
2335 // Emit an arange table for each CU we used.
2336 for (DwarfCompileUnit *CU : CUs) {
2337 std::vector<ArangeSpan> &List = Spans[CU];
2339 // Emit size of content not including length itself.
2340 unsigned ContentSize =
2341 sizeof(int16_t) + // DWARF ARange version number
2342 sizeof(int32_t) + // Offset of CU in the .debug_info section
2343 sizeof(int8_t) + // Pointer Size (in bytes)
2344 sizeof(int8_t); // Segment Size (in bytes)
2346 unsigned TupleSize = PtrSize * 2;
2348 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2350 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2352 ContentSize += Padding;
2353 ContentSize += (List.size() + 1) * TupleSize;
2355 // For each compile unit, write the list of spans it covers.
2356 Asm->OutStreamer.AddComment("Length of ARange Set");
2357 Asm->EmitInt32(ContentSize);
2358 Asm->OutStreamer.AddComment("DWARF Arange version number");
2359 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2360 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2361 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2362 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2363 Asm->EmitInt8(PtrSize);
2364 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2367 Asm->OutStreamer.EmitFill(Padding, 0xff);
2369 for (const ArangeSpan &Span : List) {
2370 Asm->EmitLabelReference(Span.Start, PtrSize);
2372 // Calculate the size as being from the span start to it's end.
2374 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2376 // For symbols without an end marker (e.g. common), we
2377 // write a single arange entry containing just that one symbol.
2378 uint64_t Size = SymSize[Span.Start];
2382 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2386 Asm->OutStreamer.AddComment("ARange terminator");
2387 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2388 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2392 // Emit visible names into a debug ranges section.
2393 void DwarfDebug::emitDebugRanges() {
2394 // Start the dwarf ranges section.
2395 Asm->OutStreamer.SwitchSection(
2396 Asm->getObjFileLowering().getDwarfRangesSection());
2398 // Size for our labels.
2399 unsigned char Size = Asm->getDataLayout().getPointerSize();
2401 // Grab the specific ranges for the compile units in the module.
2402 for (const auto &I : CUMap) {
2403 DwarfCompileUnit *TheCU = I.second;
2405 // Iterate over the misc ranges for the compile units in the module.
2406 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2407 // Emit our symbol so we can find the beginning of the range.
2408 Asm->OutStreamer.EmitLabel(List.getSym());
2410 for (const RangeSpan &Range : List.getRanges()) {
2411 const MCSymbol *Begin = Range.getStart();
2412 const MCSymbol *End = Range.getEnd();
2413 assert(Begin && "Range without a begin symbol?");
2414 assert(End && "Range without an end symbol?");
2415 if (TheCU->getRanges().size() == 1) {
2416 // Grab the begin symbol from the first range as our base.
2417 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2418 Asm->EmitLabelDifference(Begin, Base, Size);
2419 Asm->EmitLabelDifference(End, Base, Size);
2421 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2422 Asm->OutStreamer.EmitSymbolValue(End, Size);
2426 // And terminate the list with two 0 values.
2427 Asm->OutStreamer.EmitIntValue(0, Size);
2428 Asm->OutStreamer.EmitIntValue(0, Size);
2431 // Now emit a range for the CU itself.
2432 if (TheCU->getRanges().size() > 1) {
2433 Asm->OutStreamer.EmitLabel(
2434 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2435 for (const RangeSpan &Range : TheCU->getRanges()) {
2436 const MCSymbol *Begin = Range.getStart();
2437 const MCSymbol *End = Range.getEnd();
2438 assert(Begin && "Range without a begin symbol?");
2439 assert(End && "Range without an end symbol?");
2440 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2441 Asm->OutStreamer.EmitSymbolValue(End, Size);
2443 // And terminate the list with two 0 values.
2444 Asm->OutStreamer.EmitIntValue(0, Size);
2445 Asm->OutStreamer.EmitIntValue(0, Size);
2450 // DWARF5 Experimental Separate Dwarf emitters.
2452 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2453 std::unique_ptr<DwarfUnit> NewU) {
2454 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2455 U.getCUNode().getSplitDebugFilename());
2457 if (!CompilationDir.empty())
2458 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2460 addGnuPubAttributes(*NewU, Die);
2462 SkeletonHolder.addUnit(std::move(NewU));
2465 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2466 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2467 // DW_AT_addr_base, DW_AT_ranges_base.
2468 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2470 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2471 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2472 DwarfCompileUnit &NewCU = *OwnedUnit;
2473 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2474 DwarfInfoSectionSym);
2476 NewCU.initStmtList(DwarfLineSectionSym);
2478 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2483 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2485 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2486 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2487 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2489 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2491 DwarfTypeUnit &NewTU = *OwnedUnit;
2492 NewTU.setTypeSignature(TU.getTypeSignature());
2493 NewTU.setType(nullptr);
2495 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2497 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2501 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2502 // compile units that would normally be in debug_info.
2503 void DwarfDebug::emitDebugInfoDWO() {
2504 assert(useSplitDwarf() && "No split dwarf debug info?");
2505 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2506 // emit relocations into the dwo file.
2507 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2510 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2511 // abbreviations for the .debug_info.dwo section.
2512 void DwarfDebug::emitDebugAbbrevDWO() {
2513 assert(useSplitDwarf() && "No split dwarf?");
2514 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2517 void DwarfDebug::emitDebugLineDWO() {
2518 assert(useSplitDwarf() && "No split dwarf?");
2519 Asm->OutStreamer.SwitchSection(
2520 Asm->getObjFileLowering().getDwarfLineDWOSection());
2521 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2524 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2525 // string section and is identical in format to traditional .debug_str
2527 void DwarfDebug::emitDebugStrDWO() {
2528 assert(useSplitDwarf() && "No split dwarf?");
2529 const MCSection *OffSec =
2530 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2531 const MCSymbol *StrSym = DwarfStrSectionSym;
2532 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2536 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2537 if (!useSplitDwarf())
2540 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2541 return &SplitTypeUnitFileTable;
2544 static uint64_t makeTypeSignature(StringRef Identifier) {
2546 Hash.update(Identifier);
2547 // ... take the least significant 8 bytes and return those. Our MD5
2548 // implementation always returns its results in little endian, swap bytes
2550 MD5::MD5Result Result;
2552 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2555 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2556 StringRef Identifier, DIE &RefDie,
2557 DICompositeType CTy) {
2558 // Fast path if we're building some type units and one has already used the
2559 // address pool we know we're going to throw away all this work anyway, so
2560 // don't bother building dependent types.
2561 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2564 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2566 CU.addDIETypeSignature(RefDie, *TU);
2570 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2571 AddrPool.resetUsedFlag();
2573 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2574 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2575 this, &InfoHolder, getDwoLineTable(CU));
2576 DwarfTypeUnit &NewTU = *OwnedUnit;
2577 DIE &UnitDie = NewTU.getUnitDie();
2579 TypeUnitsUnderConstruction.push_back(
2580 std::make_pair(std::move(OwnedUnit), CTy));
2582 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2585 uint64_t Signature = makeTypeSignature(Identifier);
2586 NewTU.setTypeSignature(Signature);
2588 if (useSplitDwarf())
2589 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2590 DwarfTypesDWOSectionSym);
2592 CU.applyStmtList(UnitDie);
2594 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2597 NewTU.setType(NewTU.createTypeDIE(CTy));
2600 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2601 TypeUnitsUnderConstruction.clear();
2603 // Types referencing entries in the address table cannot be placed in type
2605 if (AddrPool.hasBeenUsed()) {
2607 // Remove all the types built while building this type.
2608 // This is pessimistic as some of these types might not be dependent on
2609 // the type that used an address.
2610 for (const auto &TU : TypeUnitsToAdd)
2611 DwarfTypeUnits.erase(TU.second);
2613 // Construct this type in the CU directly.
2614 // This is inefficient because all the dependent types will be rebuilt
2615 // from scratch, including building them in type units, discovering that
2616 // they depend on addresses, throwing them out and rebuilding them.
2617 CU.constructTypeDIE(RefDie, CTy);
2621 // If the type wasn't dependent on fission addresses, finish adding the type
2622 // and all its dependent types.
2623 for (auto &TU : TypeUnitsToAdd) {
2624 if (useSplitDwarf())
2625 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2626 InfoHolder.addUnit(std::move(TU.first));
2629 CU.addDIETypeSignature(RefDie, NewTU);
2632 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2633 MCSymbol *Begin, MCSymbol *End) {
2634 assert(Begin && "Begin label should not be null!");
2635 assert(End && "End label should not be null!");
2636 assert(Begin->isDefined() && "Invalid starting label");
2637 assert(End->isDefined() && "Invalid end label");
2639 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2640 if (DwarfVersion < 4)
2641 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2643 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2646 // Accelerator table mutators - add each name along with its companion
2647 // DIE to the proper table while ensuring that the name that we're going
2648 // to reference is in the string table. We do this since the names we
2649 // add may not only be identical to the names in the DIE.
2650 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2651 if (!useDwarfAccelTables())
2653 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2657 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2658 if (!useDwarfAccelTables())
2660 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2664 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2665 if (!useDwarfAccelTables())
2667 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2671 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2672 if (!useDwarfAccelTables())
2674 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),