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 assert(!CurrentFnArguments[ArgNo - 1]);
1148 CurrentFnArguments[ArgNo - 1] = Var;
1152 // Collect variable information from side table maintained by MMI.
1153 void DwarfDebug::collectVariableInfoFromMMITable(
1154 SmallPtrSet<const MDNode *, 16> &Processed) {
1155 for (const auto &VI : MMI->getVariableDbgInfo()) {
1158 Processed.insert(VI.Var);
1159 DIVariable DV(VI.Var);
1160 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1162 // If variable scope is not found then skip this variable.
1166 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1167 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1168 DbgVariable *RegVar = ConcreteVariables.back().get();
1169 RegVar->setFrameIndex(VI.Slot);
1170 addScopeVariable(Scope, RegVar);
1174 // Get .debug_loc entry for the instruction range starting at MI.
1175 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1176 const MDNode *Var = MI->getDebugVariable();
1178 assert(MI->getNumOperands() == 3);
1179 if (MI->getOperand(0).isReg()) {
1180 MachineLocation MLoc;
1181 // If the second operand is an immediate, this is a
1182 // register-indirect address.
1183 if (!MI->getOperand(1).isImm())
1184 MLoc.set(MI->getOperand(0).getReg());
1186 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1187 return DebugLocEntry::Value(Var, MLoc);
1189 if (MI->getOperand(0).isImm())
1190 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1191 if (MI->getOperand(0).isFPImm())
1192 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1193 if (MI->getOperand(0).isCImm())
1194 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1196 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1199 /// Determine whether two variable pieces overlap.
1200 static bool piecesOverlap(DIVariable P1, DIVariable P2) {
1201 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1203 unsigned l1 = P1.getPieceOffset();
1204 unsigned l2 = P2.getPieceOffset();
1205 unsigned r1 = l1 + P1.getPieceSize();
1206 unsigned r2 = l2 + P2.getPieceSize();
1207 // True where [l1,r1[ and [r1,r2[ overlap.
1208 return (l1 < r2) && (l2 < r1);
1211 /// Build the location list for all DBG_VALUEs in the function that
1212 /// describe the same variable. If the ranges of several independent
1213 /// pieces of the same variable overlap partially, split them up and
1214 /// combine the ranges. The resulting DebugLocEntries are will have
1215 /// strict monotonically increasing begin addresses and will never
1220 // Ranges History [var, loc, piece ofs size]
1221 // 0 | [x, (reg0, piece 0, 32)]
1222 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1224 // 3 | [clobber reg0]
1225 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1229 // [0-1] [x, (reg0, piece 0, 32)]
1230 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1231 // [3-4] [x, (reg1, piece 32, 32)]
1232 // [4- ] [x, (mem, piece 0, 64)]
1234 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1235 const DbgValueHistoryMap::InstrRanges &Ranges) {
1236 SmallVector<DebugLocEntry::Value, 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(),
1254 [&](DebugLocEntry::Value R) {
1255 return piecesOverlap(DIVar, DIVariable(R.getVariable()));
1257 OpenRanges.erase(Last, OpenRanges.end());
1259 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1260 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1262 const MCSymbol *EndLabel;
1264 EndLabel = getLabelAfterInsn(End);
1265 else if (std::next(I) == Ranges.end())
1266 EndLabel = FunctionEndSym;
1268 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1269 assert(EndLabel && "Forgot label after instruction ending a range!");
1271 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1273 auto Value = getDebugLocValue(Begin);
1274 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1275 bool couldMerge = false;
1277 // If this is a piece, it may belong to the current DebugLocEntry.
1278 if (DIVar.isVariablePiece()) {
1279 // Add this value to the list of open ranges.
1280 OpenRanges.push_back(Value);
1282 // Attempt to add the piece to the last entry.
1283 if (!DebugLoc.empty())
1284 if (DebugLoc.back().MergeValues(Loc))
1289 // Need to add a new DebugLocEntry. Add all values from still
1290 // valid non-overlapping pieces.
1291 if (OpenRanges.size())
1292 Loc.addValues(OpenRanges);
1294 DebugLoc.push_back(std::move(Loc));
1297 // Attempt to coalesce the ranges of two otherwise identical
1299 auto CurEntry = DebugLoc.rbegin();
1300 auto PrevEntry = std::next(CurEntry);
1301 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1302 DebugLoc.pop_back();
1304 DEBUG(dbgs() << "Values:\n";
1305 for (auto Value : CurEntry->getValues())
1306 Value.getVariable()->dump();
1307 dbgs() << "-----\n");
1312 // Find variables for each lexical scope.
1314 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1315 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1316 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1318 // Grab the variable info that was squirreled away in the MMI side-table.
1319 collectVariableInfoFromMMITable(Processed);
1321 for (const auto &I : DbgValues) {
1322 DIVariable DV(I.first);
1323 if (Processed.count(DV))
1326 // Instruction ranges, specifying where DV is accessible.
1327 const auto &Ranges = I.second;
1331 LexicalScope *Scope = nullptr;
1332 if (MDNode *IA = DV.getInlinedAt()) {
1333 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1334 Scope = LScopes.findInlinedScope(DebugLoc::get(
1335 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1337 Scope = LScopes.findLexicalScope(DV.getContext());
1338 // If variable scope is not found then skip this variable.
1342 Processed.insert(getEntireVariable(DV));
1343 const MachineInstr *MInsn = Ranges.front().first;
1344 assert(MInsn->isDebugValue() && "History must begin with debug value");
1345 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1346 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1347 DbgVariable *RegVar = ConcreteVariables.back().get();
1348 addScopeVariable(Scope, RegVar);
1350 // Check if the first DBG_VALUE is valid for the rest of the function.
1351 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1354 // Handle multiple DBG_VALUE instructions describing one variable.
1355 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1357 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1358 DebugLocList &LocList = DotDebugLocEntries.back();
1361 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1363 // Build the location list for this variable.
1364 buildLocationList(LocList.List, Ranges);
1367 // Collect info for variables that were optimized out.
1368 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1369 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1370 DIVariable DV(Variables.getElement(i));
1371 assert(DV.isVariable());
1372 if (!Processed.insert(DV))
1374 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1375 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1376 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1377 addScopeVariable(Scope, ConcreteVariables.back().get());
1382 // Return Label preceding the instruction.
1383 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1384 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1385 assert(Label && "Didn't insert label before instruction");
1389 // Return Label immediately following the instruction.
1390 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1391 return LabelsAfterInsn.lookup(MI);
1394 // Process beginning of an instruction.
1395 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1396 assert(CurMI == nullptr);
1398 // Check if source location changes, but ignore DBG_VALUE locations.
1399 if (!MI->isDebugValue()) {
1400 DebugLoc DL = MI->getDebugLoc();
1401 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1404 if (DL == PrologEndLoc) {
1405 Flags |= DWARF2_FLAG_PROLOGUE_END;
1406 PrologEndLoc = DebugLoc();
1408 if (PrologEndLoc.isUnknown())
1409 Flags |= DWARF2_FLAG_IS_STMT;
1411 if (!DL.isUnknown()) {
1412 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1413 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1415 recordSourceLine(0, 0, nullptr, 0);
1419 // Insert labels where requested.
1420 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1421 LabelsBeforeInsn.find(MI);
1424 if (I == LabelsBeforeInsn.end())
1427 // Label already assigned.
1432 PrevLabel = MMI->getContext().CreateTempSymbol();
1433 Asm->OutStreamer.EmitLabel(PrevLabel);
1435 I->second = PrevLabel;
1438 // Process end of an instruction.
1439 void DwarfDebug::endInstruction() {
1440 assert(CurMI != nullptr);
1441 // Don't create a new label after DBG_VALUE instructions.
1442 // They don't generate code.
1443 if (!CurMI->isDebugValue())
1444 PrevLabel = nullptr;
1446 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1447 LabelsAfterInsn.find(CurMI);
1451 if (I == LabelsAfterInsn.end())
1454 // Label already assigned.
1458 // We need a label after this instruction.
1460 PrevLabel = MMI->getContext().CreateTempSymbol();
1461 Asm->OutStreamer.EmitLabel(PrevLabel);
1463 I->second = PrevLabel;
1466 // Each LexicalScope has first instruction and last instruction to mark
1467 // beginning and end of a scope respectively. Create an inverse map that list
1468 // scopes starts (and ends) with an instruction. One instruction may start (or
1469 // end) multiple scopes. Ignore scopes that are not reachable.
1470 void DwarfDebug::identifyScopeMarkers() {
1471 SmallVector<LexicalScope *, 4> WorkList;
1472 WorkList.push_back(LScopes.getCurrentFunctionScope());
1473 while (!WorkList.empty()) {
1474 LexicalScope *S = WorkList.pop_back_val();
1476 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1477 if (!Children.empty())
1478 WorkList.append(Children.begin(), Children.end());
1480 if (S->isAbstractScope())
1483 for (const InsnRange &R : S->getRanges()) {
1484 assert(R.first && "InsnRange does not have first instruction!");
1485 assert(R.second && "InsnRange does not have second instruction!");
1486 requestLabelBeforeInsn(R.first);
1487 requestLabelAfterInsn(R.second);
1492 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1493 // First known non-DBG_VALUE and non-frame setup location marks
1494 // the beginning of the function body.
1495 for (const auto &MBB : *MF)
1496 for (const auto &MI : MBB)
1497 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1498 !MI.getDebugLoc().isUnknown())
1499 return MI.getDebugLoc();
1503 // Gather pre-function debug information. Assumes being called immediately
1504 // after the function entry point has been emitted.
1505 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1508 // If there's no debug info for the function we're not going to do anything.
1509 if (!MMI->hasDebugInfo())
1512 auto DI = FunctionDIs.find(MF->getFunction());
1513 if (DI == FunctionDIs.end())
1516 // Grab the lexical scopes for the function, if we don't have any of those
1517 // then we're not going to be able to do anything.
1518 LScopes.initialize(*MF);
1519 if (LScopes.empty())
1522 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1524 // Make sure that each lexical scope will have a begin/end label.
1525 identifyScopeMarkers();
1527 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1528 // belongs to so that we add to the correct per-cu line table in the
1530 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1531 // FnScope->getScopeNode() and DI->second should represent the same function,
1532 // though they may not be the same MDNode due to inline functions merged in
1533 // LTO where the debug info metadata still differs (either due to distinct
1534 // written differences - two versions of a linkonce_odr function
1535 // written/copied into two separate files, or some sub-optimal metadata that
1536 // isn't structurally identical (see: file path/name info from clang, which
1537 // includes the directory of the cpp file being built, even when the file name
1538 // is absolute (such as an <> lookup header)))
1539 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1540 assert(TheCU && "Unable to find compile unit!");
1541 if (Asm->OutStreamer.hasRawTextSupport())
1542 // Use a single line table if we are generating assembly.
1543 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1545 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1547 // Emit a label for the function so that we have a beginning address.
1548 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1549 // Assumes in correct section after the entry point.
1550 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1552 // Calculate history for local variables.
1553 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1556 // Request labels for the full history.
1557 for (const auto &I : DbgValues) {
1558 const auto &Ranges = I.second;
1562 // The first mention of a function argument gets the FunctionBeginSym
1563 // label, so arguments are visible when breaking at function entry.
1564 DIVariable DV(Ranges.front().first->getDebugVariable());
1565 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1566 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1567 if (!DV.isVariablePiece())
1568 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1570 // Mark all non-overlapping initial pieces.
1571 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1572 DIVariable Piece = I->first->getDebugVariable();
1573 if (std::all_of(Ranges.begin(), I,
1574 [&](DbgValueHistoryMap::InstrRange Pred){
1575 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1577 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1584 for (const auto &Range : Ranges) {
1585 requestLabelBeforeInsn(Range.first);
1587 requestLabelAfterInsn(Range.second);
1591 PrevInstLoc = DebugLoc();
1592 PrevLabel = FunctionBeginSym;
1594 // Record beginning of function.
1595 PrologEndLoc = findPrologueEndLoc(MF);
1596 if (!PrologEndLoc.isUnknown()) {
1597 DebugLoc FnStartDL =
1598 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1600 FnStartDL.getLine(), FnStartDL.getCol(),
1601 FnStartDL.getScope(MF->getFunction()->getContext()),
1602 // We'd like to list the prologue as "not statements" but GDB behaves
1603 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1604 DWARF2_FLAG_IS_STMT);
1608 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1609 if (addCurrentFnArgument(Var, LS))
1611 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1612 DIVariable DV = Var->getVariable();
1613 // Variables with positive arg numbers are parameters.
1614 if (unsigned ArgNum = DV.getArgNumber()) {
1615 // Keep all parameters in order at the start of the variable list to ensure
1616 // function types are correct (no out-of-order parameters)
1618 // This could be improved by only doing it for optimized builds (unoptimized
1619 // builds have the right order to begin with), searching from the back (this
1620 // would catch the unoptimized case quickly), or doing a binary search
1621 // rather than linear search.
1622 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1623 while (I != Vars.end()) {
1624 unsigned CurNum = (*I)->getVariable().getArgNumber();
1625 // A local (non-parameter) variable has been found, insert immediately
1629 // A later indexed parameter has been found, insert immediately before it.
1630 if (CurNum > ArgNum)
1634 Vars.insert(I, Var);
1638 Vars.push_back(Var);
1641 // Gather and emit post-function debug information.
1642 void DwarfDebug::endFunction(const MachineFunction *MF) {
1643 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1644 // though the beginFunction may not be called at all.
1645 // We should handle both cases.
1649 assert(CurFn == MF);
1650 assert(CurFn != nullptr);
1652 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1653 !FunctionDIs.count(MF->getFunction())) {
1654 // If we don't have a lexical scope for this function then there will
1655 // be a hole in the range information. Keep note of this by setting the
1656 // previously used section to nullptr.
1657 PrevSection = nullptr;
1663 // Define end label for subprogram.
1664 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1665 // Assumes in correct section after the entry point.
1666 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1668 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1669 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1671 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1672 collectVariableInfo(ProcessedVars);
1674 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1675 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1677 // Construct abstract scopes.
1678 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1679 DISubprogram SP(AScope->getScopeNode());
1680 assert(SP.isSubprogram());
1681 // Collect info for variables that were optimized out.
1682 DIArray Variables = SP.getVariables();
1683 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1684 DIVariable DV(Variables.getElement(i));
1685 assert(DV && DV.isVariable());
1686 if (!ProcessedVars.insert(DV))
1688 ensureAbstractVariableIsCreated(DV, DV.getContext());
1690 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1693 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1694 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1695 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1697 // Add the range of this function to the list of ranges for the CU.
1698 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1699 TheCU.addRange(std::move(Span));
1700 PrevSection = Asm->getCurrentSection();
1704 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1705 // DbgVariables except those that are also in AbstractVariables (since they
1706 // can be used cross-function)
1707 ScopeVariables.clear();
1708 CurrentFnArguments.clear();
1710 LabelsBeforeInsn.clear();
1711 LabelsAfterInsn.clear();
1712 PrevLabel = nullptr;
1716 // Register a source line with debug info. Returns the unique label that was
1717 // emitted and which provides correspondence to the source line list.
1718 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1723 unsigned Discriminator = 0;
1724 if (DIScope Scope = DIScope(S)) {
1725 assert(Scope.isScope());
1726 Fn = Scope.getFilename();
1727 Dir = Scope.getDirectory();
1728 if (Scope.isLexicalBlock())
1729 Discriminator = DILexicalBlock(S).getDiscriminator();
1731 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1732 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1733 .getOrCreateSourceID(Fn, Dir);
1735 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1739 //===----------------------------------------------------------------------===//
1741 //===----------------------------------------------------------------------===//
1743 // Emit initial Dwarf sections with a label at the start of each one.
1744 void DwarfDebug::emitSectionLabels() {
1745 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1747 // Dwarf sections base addresses.
1748 DwarfInfoSectionSym =
1749 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1750 if (useSplitDwarf()) {
1751 DwarfInfoDWOSectionSym =
1752 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1753 DwarfTypesDWOSectionSym =
1754 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1756 DwarfAbbrevSectionSym =
1757 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1758 if (useSplitDwarf())
1759 DwarfAbbrevDWOSectionSym = emitSectionSym(
1760 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1761 if (GenerateARangeSection)
1762 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1764 DwarfLineSectionSym =
1765 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1766 if (GenerateGnuPubSections) {
1767 DwarfGnuPubNamesSectionSym =
1768 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1769 DwarfGnuPubTypesSectionSym =
1770 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1771 } else if (HasDwarfPubSections) {
1772 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1773 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1776 DwarfStrSectionSym =
1777 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1778 if (useSplitDwarf()) {
1779 DwarfStrDWOSectionSym =
1780 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1781 DwarfAddrSectionSym =
1782 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1783 DwarfDebugLocSectionSym =
1784 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1786 DwarfDebugLocSectionSym =
1787 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1788 DwarfDebugRangeSectionSym =
1789 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1792 // Recursively emits a debug information entry.
1793 void DwarfDebug::emitDIE(DIE &Die) {
1794 // Get the abbreviation for this DIE.
1795 const DIEAbbrev &Abbrev = Die.getAbbrev();
1797 // Emit the code (index) for the abbreviation.
1798 if (Asm->isVerbose())
1799 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1800 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1801 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1802 dwarf::TagString(Abbrev.getTag()));
1803 Asm->EmitULEB128(Abbrev.getNumber());
1805 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1806 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1808 // Emit the DIE attribute values.
1809 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1810 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1811 dwarf::Form Form = AbbrevData[i].getForm();
1812 assert(Form && "Too many attributes for DIE (check abbreviation)");
1814 if (Asm->isVerbose()) {
1815 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1816 if (Attr == dwarf::DW_AT_accessibility)
1817 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1818 cast<DIEInteger>(Values[i])->getValue()));
1821 // Emit an attribute using the defined form.
1822 Values[i]->EmitValue(Asm, Form);
1825 // Emit the DIE children if any.
1826 if (Abbrev.hasChildren()) {
1827 for (auto &Child : Die.getChildren())
1830 Asm->OutStreamer.AddComment("End Of Children Mark");
1835 // Emit the debug info section.
1836 void DwarfDebug::emitDebugInfo() {
1837 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1839 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1842 // Emit the abbreviation section.
1843 void DwarfDebug::emitAbbreviations() {
1844 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1846 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1849 // Emit the last address of the section and the end of the line matrix.
1850 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1851 // Define last address of section.
1852 Asm->OutStreamer.AddComment("Extended Op");
1855 Asm->OutStreamer.AddComment("Op size");
1856 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1857 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1858 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1860 Asm->OutStreamer.AddComment("Section end label");
1862 Asm->OutStreamer.EmitSymbolValue(
1863 Asm->GetTempSymbol("section_end", SectionEnd),
1864 Asm->getDataLayout().getPointerSize());
1866 // Mark end of matrix.
1867 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1873 // Emit visible names into a hashed accelerator table section.
1874 void DwarfDebug::emitAccelNames() {
1875 AccelNames.FinalizeTable(Asm, "Names");
1876 Asm->OutStreamer.SwitchSection(
1877 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1878 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1879 Asm->OutStreamer.EmitLabel(SectionBegin);
1881 // Emit the full data.
1882 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1885 // Emit objective C classes and categories into a hashed accelerator table
1887 void DwarfDebug::emitAccelObjC() {
1888 AccelObjC.FinalizeTable(Asm, "ObjC");
1889 Asm->OutStreamer.SwitchSection(
1890 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1891 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1892 Asm->OutStreamer.EmitLabel(SectionBegin);
1894 // Emit the full data.
1895 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1898 // Emit namespace dies into a hashed accelerator table.
1899 void DwarfDebug::emitAccelNamespaces() {
1900 AccelNamespace.FinalizeTable(Asm, "namespac");
1901 Asm->OutStreamer.SwitchSection(
1902 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1903 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1904 Asm->OutStreamer.EmitLabel(SectionBegin);
1906 // Emit the full data.
1907 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1910 // Emit type dies into a hashed accelerator table.
1911 void DwarfDebug::emitAccelTypes() {
1913 AccelTypes.FinalizeTable(Asm, "types");
1914 Asm->OutStreamer.SwitchSection(
1915 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1916 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1917 Asm->OutStreamer.EmitLabel(SectionBegin);
1919 // Emit the full data.
1920 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1923 // Public name handling.
1924 // The format for the various pubnames:
1926 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1927 // for the DIE that is named.
1929 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1930 // into the CU and the index value is computed according to the type of value
1931 // for the DIE that is named.
1933 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1934 // it's the offset within the debug_info/debug_types dwo section, however, the
1935 // reference in the pubname header doesn't change.
1937 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1938 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1940 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1942 // We could have a specification DIE that has our most of our knowledge,
1943 // look for that now.
1944 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1946 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1947 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1948 Linkage = dwarf::GIEL_EXTERNAL;
1949 } else if (Die->findAttribute(dwarf::DW_AT_external))
1950 Linkage = dwarf::GIEL_EXTERNAL;
1952 switch (Die->getTag()) {
1953 case dwarf::DW_TAG_class_type:
1954 case dwarf::DW_TAG_structure_type:
1955 case dwarf::DW_TAG_union_type:
1956 case dwarf::DW_TAG_enumeration_type:
1957 return dwarf::PubIndexEntryDescriptor(
1958 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1959 ? dwarf::GIEL_STATIC
1960 : dwarf::GIEL_EXTERNAL);
1961 case dwarf::DW_TAG_typedef:
1962 case dwarf::DW_TAG_base_type:
1963 case dwarf::DW_TAG_subrange_type:
1964 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1965 case dwarf::DW_TAG_namespace:
1966 return dwarf::GIEK_TYPE;
1967 case dwarf::DW_TAG_subprogram:
1968 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1969 case dwarf::DW_TAG_constant:
1970 case dwarf::DW_TAG_variable:
1971 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1972 case dwarf::DW_TAG_enumerator:
1973 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1974 dwarf::GIEL_STATIC);
1976 return dwarf::GIEK_NONE;
1980 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1982 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1983 const MCSection *PSec =
1984 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1985 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1987 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1990 void DwarfDebug::emitDebugPubSection(
1991 bool GnuStyle, const MCSection *PSec, StringRef Name,
1992 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1993 for (const auto &NU : CUMap) {
1994 DwarfCompileUnit *TheU = NU.second;
1996 const auto &Globals = (TheU->*Accessor)();
1998 if (Globals.empty())
2001 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2003 unsigned ID = TheU->getUniqueID();
2005 // Start the dwarf pubnames section.
2006 Asm->OutStreamer.SwitchSection(PSec);
2009 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2010 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2011 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2012 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2014 Asm->OutStreamer.EmitLabel(BeginLabel);
2016 Asm->OutStreamer.AddComment("DWARF Version");
2017 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2019 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2020 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2022 Asm->OutStreamer.AddComment("Compilation Unit Length");
2023 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2025 // Emit the pubnames for this compilation unit.
2026 for (const auto &GI : Globals) {
2027 const char *Name = GI.getKeyData();
2028 const DIE *Entity = GI.second;
2030 Asm->OutStreamer.AddComment("DIE offset");
2031 Asm->EmitInt32(Entity->getOffset());
2034 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2035 Asm->OutStreamer.AddComment(
2036 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2037 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2038 Asm->EmitInt8(Desc.toBits());
2041 Asm->OutStreamer.AddComment("External Name");
2042 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2045 Asm->OutStreamer.AddComment("End Mark");
2047 Asm->OutStreamer.EmitLabel(EndLabel);
2051 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2052 const MCSection *PSec =
2053 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2054 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2056 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2059 // Emit visible names into a debug str section.
2060 void DwarfDebug::emitDebugStr() {
2061 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2062 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2065 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2066 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2067 const DITypeIdentifierMap &Map,
2068 ArrayRef<DebugLocEntry::Value> Values) {
2069 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
2070 return DIVariable(P.getVariable()).isVariablePiece();
2071 }) && "all values are expected to be pieces");
2072 assert(std::is_sorted(Values.begin(), Values.end()) &&
2073 "pieces are expected to be sorted");
2075 unsigned Offset = 0;
2076 for (auto Piece : Values) {
2077 DIVariable Var(Piece.getVariable());
2078 unsigned PieceOffset = Var.getPieceOffset();
2079 unsigned PieceSize = Var.getPieceSize();
2080 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
2081 if (Offset < PieceOffset) {
2082 // The DWARF spec seriously mandates pieces with no locations for gaps.
2083 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2084 Offset += PieceOffset-Offset;
2087 Offset += PieceSize;
2089 const unsigned SizeOfByte = 8;
2090 assert(!Var.isIndirect() && "indirect address for piece");
2092 unsigned VarSize = Var.getSizeInBits(Map);
2093 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2094 && "piece is larger than or outside of variable");
2095 assert(PieceSize*SizeOfByte != VarSize
2096 && "piece covers entire variable");
2098 if (Piece.isLocation() && Piece.getLoc().isReg())
2099 Asm->EmitDwarfRegOpPiece(Streamer,
2101 PieceSize*SizeOfByte);
2103 emitDebugLocValue(Streamer, Piece);
2104 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2110 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2111 const DebugLocEntry &Entry) {
2112 const DebugLocEntry::Value Value = Entry.getValues()[0];
2113 DIVariable DV(Value.getVariable());
2114 if (DV.isVariablePiece())
2115 // Emit all pieces that belong to the same variable and range.
2116 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2118 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2119 emitDebugLocValue(Streamer, Value);
2122 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2123 const DebugLocEntry::Value &Value) {
2124 DIVariable DV(Value.getVariable());
2126 if (Value.isInt()) {
2127 DIBasicType BTy(resolve(DV.getType()));
2128 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2129 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2130 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2131 Streamer.EmitSLEB128(Value.getInt());
2133 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2134 Streamer.EmitULEB128(Value.getInt());
2136 } else if (Value.isLocation()) {
2137 MachineLocation Loc = Value.getLoc();
2138 if (!DV.hasComplexAddress())
2140 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2142 // Complex address entry.
2143 unsigned N = DV.getNumAddrElements();
2145 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2146 if (Loc.getOffset()) {
2148 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2149 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2150 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2151 Streamer.EmitSLEB128(DV.getAddrElement(1));
2153 // If first address element is OpPlus then emit
2154 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2155 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2156 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2160 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2163 // Emit remaining complex address elements.
2164 for (; i < N; ++i) {
2165 uint64_t Element = DV.getAddrElement(i);
2166 if (Element == DIBuilder::OpPlus) {
2167 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2168 Streamer.EmitULEB128(DV.getAddrElement(++i));
2169 } else if (Element == DIBuilder::OpDeref) {
2171 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2172 } else if (Element == DIBuilder::OpPiece) {
2174 // handled in emitDebugLocEntry.
2176 llvm_unreachable("unknown Opcode found in complex address");
2180 // else ... ignore constant fp. There is not any good way to
2181 // to represent them here in dwarf.
2185 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2186 Asm->OutStreamer.AddComment("Loc expr size");
2187 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2188 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2189 Asm->EmitLabelDifference(end, begin, 2);
2190 Asm->OutStreamer.EmitLabel(begin);
2192 APByteStreamer Streamer(*Asm);
2193 emitDebugLocEntry(Streamer, Entry);
2195 Asm->OutStreamer.EmitLabel(end);
2198 // Emit locations into the debug loc section.
2199 void DwarfDebug::emitDebugLoc() {
2200 // Start the dwarf loc section.
2201 Asm->OutStreamer.SwitchSection(
2202 Asm->getObjFileLowering().getDwarfLocSection());
2203 unsigned char Size = Asm->getDataLayout().getPointerSize();
2204 for (const auto &DebugLoc : DotDebugLocEntries) {
2205 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2206 const DwarfCompileUnit *CU = DebugLoc.CU;
2207 assert(!CU->getRanges().empty());
2208 for (const auto &Entry : DebugLoc.List) {
2209 // Set up the range. This range is relative to the entry point of the
2210 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2211 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2212 if (CU->getRanges().size() == 1) {
2213 // Grab the begin symbol from the first range as our base.
2214 const MCSymbol *Base = CU->getRanges()[0].getStart();
2215 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2216 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2218 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2219 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2222 emitDebugLocEntryLocation(Entry);
2224 Asm->OutStreamer.EmitIntValue(0, Size);
2225 Asm->OutStreamer.EmitIntValue(0, Size);
2229 void DwarfDebug::emitDebugLocDWO() {
2230 Asm->OutStreamer.SwitchSection(
2231 Asm->getObjFileLowering().getDwarfLocDWOSection());
2232 for (const auto &DebugLoc : DotDebugLocEntries) {
2233 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2234 for (const auto &Entry : DebugLoc.List) {
2235 // Just always use start_length for now - at least that's one address
2236 // rather than two. We could get fancier and try to, say, reuse an
2237 // address we know we've emitted elsewhere (the start of the function?
2238 // The start of the CU or CU subrange that encloses this range?)
2239 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2240 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2241 Asm->EmitULEB128(idx);
2242 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2244 emitDebugLocEntryLocation(Entry);
2246 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2251 const MCSymbol *Start, *End;
2254 // Emit a debug aranges section, containing a CU lookup for any
2255 // address we can tie back to a CU.
2256 void DwarfDebug::emitDebugARanges() {
2257 // Start the dwarf aranges section.
2258 Asm->OutStreamer.SwitchSection(
2259 Asm->getObjFileLowering().getDwarfARangesSection());
2261 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2265 // Build a list of sections used.
2266 std::vector<const MCSection *> Sections;
2267 for (const auto &it : SectionMap) {
2268 const MCSection *Section = it.first;
2269 Sections.push_back(Section);
2272 // Sort the sections into order.
2273 // This is only done to ensure consistent output order across different runs.
2274 std::sort(Sections.begin(), Sections.end(), SectionSort);
2276 // Build a set of address spans, sorted by CU.
2277 for (const MCSection *Section : Sections) {
2278 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2279 if (List.size() < 2)
2282 // Sort the symbols by offset within the section.
2283 std::sort(List.begin(), List.end(),
2284 [&](const SymbolCU &A, const SymbolCU &B) {
2285 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2286 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2288 // Symbols with no order assigned should be placed at the end.
2289 // (e.g. section end labels)
2297 // If we have no section (e.g. common), just write out
2298 // individual spans for each symbol.
2300 for (const SymbolCU &Cur : List) {
2302 Span.Start = Cur.Sym;
2305 Spans[Cur.CU].push_back(Span);
2308 // Build spans between each label.
2309 const MCSymbol *StartSym = List[0].Sym;
2310 for (size_t n = 1, e = List.size(); n < e; n++) {
2311 const SymbolCU &Prev = List[n - 1];
2312 const SymbolCU &Cur = List[n];
2314 // Try and build the longest span we can within the same CU.
2315 if (Cur.CU != Prev.CU) {
2317 Span.Start = StartSym;
2319 Spans[Prev.CU].push_back(Span);
2326 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2328 // Build a list of CUs used.
2329 std::vector<DwarfCompileUnit *> CUs;
2330 for (const auto &it : Spans) {
2331 DwarfCompileUnit *CU = it.first;
2335 // Sort the CU list (again, to ensure consistent output order).
2336 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2337 return A->getUniqueID() < B->getUniqueID();
2340 // Emit an arange table for each CU we used.
2341 for (DwarfCompileUnit *CU : CUs) {
2342 std::vector<ArangeSpan> &List = Spans[CU];
2344 // Emit size of content not including length itself.
2345 unsigned ContentSize =
2346 sizeof(int16_t) + // DWARF ARange version number
2347 sizeof(int32_t) + // Offset of CU in the .debug_info section
2348 sizeof(int8_t) + // Pointer Size (in bytes)
2349 sizeof(int8_t); // Segment Size (in bytes)
2351 unsigned TupleSize = PtrSize * 2;
2353 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2355 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2357 ContentSize += Padding;
2358 ContentSize += (List.size() + 1) * TupleSize;
2360 // For each compile unit, write the list of spans it covers.
2361 Asm->OutStreamer.AddComment("Length of ARange Set");
2362 Asm->EmitInt32(ContentSize);
2363 Asm->OutStreamer.AddComment("DWARF Arange version number");
2364 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2365 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2366 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2367 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2368 Asm->EmitInt8(PtrSize);
2369 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2372 Asm->OutStreamer.EmitFill(Padding, 0xff);
2374 for (const ArangeSpan &Span : List) {
2375 Asm->EmitLabelReference(Span.Start, PtrSize);
2377 // Calculate the size as being from the span start to it's end.
2379 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2381 // For symbols without an end marker (e.g. common), we
2382 // write a single arange entry containing just that one symbol.
2383 uint64_t Size = SymSize[Span.Start];
2387 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2391 Asm->OutStreamer.AddComment("ARange terminator");
2392 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2393 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2397 // Emit visible names into a debug ranges section.
2398 void DwarfDebug::emitDebugRanges() {
2399 // Start the dwarf ranges section.
2400 Asm->OutStreamer.SwitchSection(
2401 Asm->getObjFileLowering().getDwarfRangesSection());
2403 // Size for our labels.
2404 unsigned char Size = Asm->getDataLayout().getPointerSize();
2406 // Grab the specific ranges for the compile units in the module.
2407 for (const auto &I : CUMap) {
2408 DwarfCompileUnit *TheCU = I.second;
2410 // Iterate over the misc ranges for the compile units in the module.
2411 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2412 // Emit our symbol so we can find the beginning of the range.
2413 Asm->OutStreamer.EmitLabel(List.getSym());
2415 for (const RangeSpan &Range : List.getRanges()) {
2416 const MCSymbol *Begin = Range.getStart();
2417 const MCSymbol *End = Range.getEnd();
2418 assert(Begin && "Range without a begin symbol?");
2419 assert(End && "Range without an end symbol?");
2420 if (TheCU->getRanges().size() == 1) {
2421 // Grab the begin symbol from the first range as our base.
2422 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2423 Asm->EmitLabelDifference(Begin, Base, Size);
2424 Asm->EmitLabelDifference(End, Base, Size);
2426 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2427 Asm->OutStreamer.EmitSymbolValue(End, Size);
2431 // And terminate the list with two 0 values.
2432 Asm->OutStreamer.EmitIntValue(0, Size);
2433 Asm->OutStreamer.EmitIntValue(0, Size);
2436 // Now emit a range for the CU itself.
2437 if (TheCU->getRanges().size() > 1) {
2438 Asm->OutStreamer.EmitLabel(
2439 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2440 for (const RangeSpan &Range : TheCU->getRanges()) {
2441 const MCSymbol *Begin = Range.getStart();
2442 const MCSymbol *End = Range.getEnd();
2443 assert(Begin && "Range without a begin symbol?");
2444 assert(End && "Range without an end symbol?");
2445 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2446 Asm->OutStreamer.EmitSymbolValue(End, Size);
2448 // And terminate the list with two 0 values.
2449 Asm->OutStreamer.EmitIntValue(0, Size);
2450 Asm->OutStreamer.EmitIntValue(0, Size);
2455 // DWARF5 Experimental Separate Dwarf emitters.
2457 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2458 std::unique_ptr<DwarfUnit> NewU) {
2459 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2460 U.getCUNode().getSplitDebugFilename());
2462 if (!CompilationDir.empty())
2463 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2465 addGnuPubAttributes(*NewU, Die);
2467 SkeletonHolder.addUnit(std::move(NewU));
2470 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2471 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2472 // DW_AT_addr_base, DW_AT_ranges_base.
2473 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2475 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2476 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2477 DwarfCompileUnit &NewCU = *OwnedUnit;
2478 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2479 DwarfInfoSectionSym);
2481 NewCU.initStmtList(DwarfLineSectionSym);
2483 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2488 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2490 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2491 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2492 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2494 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2496 DwarfTypeUnit &NewTU = *OwnedUnit;
2497 NewTU.setTypeSignature(TU.getTypeSignature());
2498 NewTU.setType(nullptr);
2500 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2502 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2506 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2507 // compile units that would normally be in debug_info.
2508 void DwarfDebug::emitDebugInfoDWO() {
2509 assert(useSplitDwarf() && "No split dwarf debug info?");
2510 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2511 // emit relocations into the dwo file.
2512 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2515 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2516 // abbreviations for the .debug_info.dwo section.
2517 void DwarfDebug::emitDebugAbbrevDWO() {
2518 assert(useSplitDwarf() && "No split dwarf?");
2519 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2522 void DwarfDebug::emitDebugLineDWO() {
2523 assert(useSplitDwarf() && "No split dwarf?");
2524 Asm->OutStreamer.SwitchSection(
2525 Asm->getObjFileLowering().getDwarfLineDWOSection());
2526 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2529 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2530 // string section and is identical in format to traditional .debug_str
2532 void DwarfDebug::emitDebugStrDWO() {
2533 assert(useSplitDwarf() && "No split dwarf?");
2534 const MCSection *OffSec =
2535 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2536 const MCSymbol *StrSym = DwarfStrSectionSym;
2537 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2541 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2542 if (!useSplitDwarf())
2545 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2546 return &SplitTypeUnitFileTable;
2549 static uint64_t makeTypeSignature(StringRef Identifier) {
2551 Hash.update(Identifier);
2552 // ... take the least significant 8 bytes and return those. Our MD5
2553 // implementation always returns its results in little endian, swap bytes
2555 MD5::MD5Result Result;
2557 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2560 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2561 StringRef Identifier, DIE &RefDie,
2562 DICompositeType CTy) {
2563 // Fast path if we're building some type units and one has already used the
2564 // address pool we know we're going to throw away all this work anyway, so
2565 // don't bother building dependent types.
2566 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2569 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2571 CU.addDIETypeSignature(RefDie, *TU);
2575 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2576 AddrPool.resetUsedFlag();
2578 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2579 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2580 this, &InfoHolder, getDwoLineTable(CU));
2581 DwarfTypeUnit &NewTU = *OwnedUnit;
2582 DIE &UnitDie = NewTU.getUnitDie();
2584 TypeUnitsUnderConstruction.push_back(
2585 std::make_pair(std::move(OwnedUnit), CTy));
2587 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2590 uint64_t Signature = makeTypeSignature(Identifier);
2591 NewTU.setTypeSignature(Signature);
2593 if (useSplitDwarf())
2594 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2595 DwarfTypesDWOSectionSym);
2597 CU.applyStmtList(UnitDie);
2599 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2602 NewTU.setType(NewTU.createTypeDIE(CTy));
2605 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2606 TypeUnitsUnderConstruction.clear();
2608 // Types referencing entries in the address table cannot be placed in type
2610 if (AddrPool.hasBeenUsed()) {
2612 // Remove all the types built while building this type.
2613 // This is pessimistic as some of these types might not be dependent on
2614 // the type that used an address.
2615 for (const auto &TU : TypeUnitsToAdd)
2616 DwarfTypeUnits.erase(TU.second);
2618 // Construct this type in the CU directly.
2619 // This is inefficient because all the dependent types will be rebuilt
2620 // from scratch, including building them in type units, discovering that
2621 // they depend on addresses, throwing them out and rebuilding them.
2622 CU.constructTypeDIE(RefDie, CTy);
2626 // If the type wasn't dependent on fission addresses, finish adding the type
2627 // and all its dependent types.
2628 for (auto &TU : TypeUnitsToAdd) {
2629 if (useSplitDwarf())
2630 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2631 InfoHolder.addUnit(std::move(TU.first));
2634 CU.addDIETypeSignature(RefDie, NewTU);
2637 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2638 MCSymbol *Begin, MCSymbol *End) {
2639 assert(Begin && "Begin label should not be null!");
2640 assert(End && "End label should not be null!");
2641 assert(Begin->isDefined() && "Invalid starting label");
2642 assert(End->isDefined() && "Invalid end label");
2644 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2645 if (DwarfVersion < 4)
2646 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2648 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2651 // Accelerator table mutators - add each name along with its companion
2652 // DIE to the proper table while ensuring that the name that we're going
2653 // to reference is in the string table. We do this since the names we
2654 // add may not only be identical to the names in the DIE.
2655 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2656 if (!useDwarfAccelTables())
2658 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2662 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2663 if (!useDwarfAccelTables())
2665 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2669 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2670 if (!useDwarfAccelTables())
2672 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2676 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2677 if (!useDwarfAccelTables())
2679 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),