1 //===-- llvm/CodeGen/DwarfDebug.cpp - Dwarf Debug Framework ---------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains support for writing dwarf debug info into asm files.
12 //===----------------------------------------------------------------------===//
14 #include "ByteStreamer.h"
15 #include "DwarfDebug.h"
18 #include "DwarfUnit.h"
19 #include "llvm/ADT/STLExtras.h"
20 #include "llvm/ADT/Statistic.h"
21 #include "llvm/ADT/StringExtras.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineModuleInfo.h"
25 #include "llvm/IR/Constants.h"
26 #include "llvm/IR/DIBuilder.h"
27 #include "llvm/IR/DataLayout.h"
28 #include "llvm/IR/DebugInfo.h"
29 #include "llvm/IR/Instructions.h"
30 #include "llvm/IR/Module.h"
31 #include "llvm/IR/ValueHandle.h"
32 #include "llvm/MC/MCAsmInfo.h"
33 #include "llvm/MC/MCSection.h"
34 #include "llvm/MC/MCStreamer.h"
35 #include "llvm/MC/MCSymbol.h"
36 #include "llvm/Support/CommandLine.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/Dwarf.h"
39 #include "llvm/Support/Endian.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/FormattedStream.h"
42 #include "llvm/Support/LEB128.h"
43 #include "llvm/Support/MD5.h"
44 #include "llvm/Support/Path.h"
45 #include "llvm/Support/Timer.h"
46 #include "llvm/Target/TargetFrameLowering.h"
47 #include "llvm/Target/TargetLoweringObjectFile.h"
48 #include "llvm/Target/TargetMachine.h"
49 #include "llvm/Target/TargetOptions.h"
50 #include "llvm/Target/TargetRegisterInfo.h"
51 #include "llvm/Target/TargetSubtargetInfo.h"
54 #define DEBUG_TYPE "dwarfdebug"
57 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
58 cl::desc("Disable debug info printing"));
60 static cl::opt<bool> UnknownLocations(
61 "use-unknown-locations", cl::Hidden,
62 cl::desc("Make an absence of debug location information explicit."),
66 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
67 cl::desc("Generate GNU-style pubnames and pubtypes"),
70 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
72 cl::desc("Generate dwarf aranges"),
76 enum DefaultOnOff { Default, Enable, Disable };
79 static cl::opt<DefaultOnOff>
80 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
81 cl::desc("Output prototype dwarf accelerator tables."),
82 cl::values(clEnumVal(Default, "Default for platform"),
83 clEnumVal(Enable, "Enabled"),
84 clEnumVal(Disable, "Disabled"), clEnumValEnd),
87 static cl::opt<DefaultOnOff>
88 SplitDwarf("split-dwarf", cl::Hidden,
89 cl::desc("Output DWARF5 split debug info."),
90 cl::values(clEnumVal(Default, "Default for platform"),
91 clEnumVal(Enable, "Enabled"),
92 clEnumVal(Disable, "Disabled"), clEnumValEnd),
95 static cl::opt<DefaultOnOff>
96 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
97 cl::desc("Generate DWARF pubnames and pubtypes sections"),
98 cl::values(clEnumVal(Default, "Default for platform"),
99 clEnumVal(Enable, "Enabled"),
100 clEnumVal(Disable, "Disabled"), clEnumValEnd),
103 static const char *const DWARFGroupName = "DWARF Emission";
104 static const char *const DbgTimerName = "DWARF Debug Writer";
106 //===----------------------------------------------------------------------===//
108 /// resolve - Look in the DwarfDebug map for the MDNode that
109 /// corresponds to the reference.
110 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
111 return DD->resolve(Ref);
114 bool DbgVariable::isBlockByrefVariable() const {
115 assert(Var.isVariable() && "Invalid complex DbgVariable!");
116 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
119 DIType DbgVariable::getType() const {
120 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
121 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
122 // addresses instead.
123 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
124 /* Byref variables, in Blocks, are declared by the programmer as
125 "SomeType VarName;", but the compiler creates a
126 __Block_byref_x_VarName struct, and gives the variable VarName
127 either the struct, or a pointer to the struct, as its type. This
128 is necessary for various behind-the-scenes things the compiler
129 needs to do with by-reference variables in blocks.
131 However, as far as the original *programmer* is concerned, the
132 variable should still have type 'SomeType', as originally declared.
134 The following function dives into the __Block_byref_x_VarName
135 struct to find the original type of the variable. This will be
136 passed back to the code generating the type for the Debug
137 Information Entry for the variable 'VarName'. 'VarName' will then
138 have the original type 'SomeType' in its debug information.
140 The original type 'SomeType' will be the type of the field named
141 'VarName' inside the __Block_byref_x_VarName struct.
143 NOTE: In order for this to not completely fail on the debugger
144 side, the Debug Information Entry for the variable VarName needs to
145 have a DW_AT_location that tells the debugger how to unwind through
146 the pointers and __Block_byref_x_VarName struct to find the actual
147 value of the variable. The function addBlockByrefType does this. */
149 uint16_t tag = Ty.getTag();
151 if (tag == dwarf::DW_TAG_pointer_type)
152 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
154 DIArray Elements = DICompositeType(subType).getElements();
155 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
156 DIDerivedType DT(Elements.getElement(i));
157 if (getName() == DT.getName())
158 return (resolve(DT.getTypeDerivedFrom()));
164 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
165 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
166 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
167 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
169 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
170 : Asm(A), MMI(Asm->MMI), FirstCU(nullptr), PrevLabel(nullptr),
171 GlobalRangeCount(0), InfoHolder(A, "info_string", DIEValueAllocator),
172 UsedNonDefaultText(false),
173 SkeletonHolder(A, "skel_string", DIEValueAllocator),
174 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
175 dwarf::DW_FORM_data4)),
176 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
177 dwarf::DW_FORM_data4)),
178 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
179 dwarf::DW_FORM_data4)),
180 AccelTypes(TypeAtoms) {
182 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = nullptr;
183 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = nullptr;
184 DwarfLineSectionSym = nullptr;
185 DwarfAddrSectionSym = nullptr;
186 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = nullptr;
187 FunctionBeginSym = FunctionEndSym = nullptr;
191 // Turn on accelerator tables for Darwin by default, pubnames by
192 // default for non-Darwin, and handle split dwarf.
193 bool IsDarwin = Triple(A->getTargetTriple()).isOSDarwin();
195 if (DwarfAccelTables == Default)
196 HasDwarfAccelTables = IsDarwin;
198 HasDwarfAccelTables = DwarfAccelTables == Enable;
200 if (SplitDwarf == Default)
201 HasSplitDwarf = false;
203 HasSplitDwarf = SplitDwarf == Enable;
205 if (DwarfPubSections == Default)
206 HasDwarfPubSections = !IsDarwin;
208 HasDwarfPubSections = DwarfPubSections == Enable;
210 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
211 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
212 : MMI->getModule()->getDwarfVersion();
214 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
217 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
222 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
223 DwarfDebug::~DwarfDebug() { }
225 // Switch to the specified MCSection and emit an assembler
226 // temporary label to it if SymbolStem is specified.
227 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
228 const char *SymbolStem = nullptr) {
229 Asm->OutStreamer.SwitchSection(Section);
233 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
234 Asm->OutStreamer.EmitLabel(TmpSym);
238 static bool isObjCClass(StringRef Name) {
239 return Name.startswith("+") || Name.startswith("-");
242 static bool hasObjCCategory(StringRef Name) {
243 if (!isObjCClass(Name))
246 return Name.find(") ") != StringRef::npos;
249 static void getObjCClassCategory(StringRef In, StringRef &Class,
250 StringRef &Category) {
251 if (!hasObjCCategory(In)) {
252 Class = In.slice(In.find('[') + 1, In.find(' '));
257 Class = In.slice(In.find('[') + 1, In.find('('));
258 Category = In.slice(In.find('[') + 1, In.find(' '));
262 static StringRef getObjCMethodName(StringRef In) {
263 return In.slice(In.find(' ') + 1, In.find(']'));
266 // Helper for sorting sections into a stable output order.
267 static bool SectionSort(const MCSection *A, const MCSection *B) {
268 std::string LA = (A ? A->getLabelBeginName() : "");
269 std::string LB = (B ? B->getLabelBeginName() : "");
273 // Add the various names to the Dwarf accelerator table names.
274 // TODO: Determine whether or not we should add names for programs
275 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
276 // is only slightly different than the lookup of non-standard ObjC names.
277 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
278 if (!SP.isDefinition())
280 addAccelName(SP.getName(), Die);
282 // If the linkage name is different than the name, go ahead and output
283 // that as well into the name table.
284 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
285 addAccelName(SP.getLinkageName(), Die);
287 // If this is an Objective-C selector name add it to the ObjC accelerator
289 if (isObjCClass(SP.getName())) {
290 StringRef Class, Category;
291 getObjCClassCategory(SP.getName(), Class, Category);
292 addAccelObjC(Class, Die);
294 addAccelObjC(Category, Die);
295 // Also add the base method name to the name table.
296 addAccelName(getObjCMethodName(SP.getName()), Die);
300 /// isSubprogramContext - Return true if Context is either a subprogram
301 /// or another context nested inside a subprogram.
302 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
305 DIDescriptor D(Context);
306 if (D.isSubprogram())
309 return isSubprogramContext(resolve(DIType(Context).getContext()));
313 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
314 // and DW_AT_high_pc attributes. If there are global variables in this
315 // scope then create and insert DIEs for these variables.
316 DIE &DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
318 DIE *SPDie = SPCU.getOrCreateSubprogramDIE(SP);
320 attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
322 const TargetRegisterInfo *RI = Asm->TM.getSubtargetImpl()->getRegisterInfo();
323 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
324 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
326 // Add name to the name table, we do this here because we're guaranteed
327 // to have concrete versions of our DW_TAG_subprogram nodes.
328 addSubprogramNames(SP, *SPDie);
333 /// Check whether we should create a DIE for the given Scope, return true
334 /// if we don't create a DIE (the corresponding DIE is null).
335 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
336 if (Scope->isAbstractScope())
339 // We don't create a DIE if there is no Range.
340 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
344 if (Ranges.size() > 1)
347 // We don't create a DIE if we have a single Range and the end label
349 return !getLabelAfterInsn(Ranges.front().second);
352 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
353 dwarf::Attribute A, const MCSymbol *L,
354 const MCSymbol *Sec) {
355 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
356 U.addSectionLabel(D, A, L);
358 U.addSectionDelta(D, A, L, Sec);
361 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
362 const SmallVectorImpl<InsnRange> &Range) {
363 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
364 // emitting it appropriately.
365 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
367 // Under fission, ranges are specified by constant offsets relative to the
368 // CU's DW_AT_GNU_ranges_base.
370 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
371 DwarfDebugRangeSectionSym);
373 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
374 DwarfDebugRangeSectionSym);
376 RangeSpanList List(RangeSym);
377 for (const InsnRange &R : Range) {
378 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
379 List.addRange(std::move(Span));
382 // Add the range list to the set of ranges to be emitted.
383 TheCU.addRangeList(std::move(List));
386 void DwarfDebug::attachRangesOrLowHighPC(DwarfCompileUnit &TheCU, DIE &Die,
387 const SmallVectorImpl<InsnRange> &Ranges) {
388 assert(!Ranges.empty());
389 if (Ranges.size() == 1)
390 attachLowHighPC(TheCU, Die, getLabelBeforeInsn(Ranges.front().first),
391 getLabelAfterInsn(Ranges.front().second));
393 addScopeRangeList(TheCU, Die, Ranges);
396 // Construct new DW_TAG_lexical_block for this scope and attach
397 // DW_AT_low_pc/DW_AT_high_pc labels.
399 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
400 LexicalScope *Scope) {
401 if (isLexicalScopeDIENull(Scope))
404 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
405 if (Scope->isAbstractScope())
408 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
413 // This scope represents inlined body of a function. Construct DIE to
414 // represent this concrete inlined copy of the function.
416 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
417 LexicalScope *Scope) {
418 assert(Scope->getScopeNode());
419 DIScope DS(Scope->getScopeNode());
420 DISubprogram InlinedSP = getDISubprogram(DS);
421 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
422 // was inlined from another compile unit.
423 DIE *OriginDIE = AbstractSPDies[InlinedSP];
424 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
426 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
427 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
429 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
431 InlinedSubprogramDIEs.insert(OriginDIE);
433 // Add the call site information to the DIE.
434 DILocation DL(Scope->getInlinedAt());
435 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
436 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
437 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
439 // Add name to the name table, we do this here because we're guaranteed
440 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
441 addSubprogramNames(InlinedSP, *ScopeDIE);
446 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
448 const LexicalScope &Scope,
449 DIE *&ObjectPointer) {
450 auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
451 if (DV.isObjectPointer())
452 ObjectPointer = Var.get();
456 DIE *DwarfDebug::createScopeChildrenDIE(
457 DwarfCompileUnit &TheCU, LexicalScope *Scope,
458 SmallVectorImpl<std::unique_ptr<DIE>> &Children) {
459 DIE *ObjectPointer = nullptr;
461 // Collect arguments for current function.
462 if (LScopes.isCurrentFunctionScope(Scope)) {
463 for (DbgVariable *ArgDV : CurrentFnArguments)
466 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
468 // If this is a variadic function, add an unspecified parameter.
469 DISubprogram SP(Scope->getScopeNode());
470 DITypeArray FnArgs = SP.getType().getTypeArray();
471 // If we have a single element of null, it is a function that returns void.
472 // If we have more than one elements and the last one is null, it is a
473 // variadic function.
474 if (FnArgs.getNumElements() > 1 &&
475 !FnArgs.getElement(FnArgs.getNumElements() - 1))
477 make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
480 // Collect lexical scope children first.
481 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
482 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
484 for (LexicalScope *LS : Scope->getChildren())
485 if (std::unique_ptr<DIE> Nested = constructScopeDIE(TheCU, LS))
486 Children.push_back(std::move(Nested));
487 return ObjectPointer;
490 void DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
491 LexicalScope *Scope, DIE &ScopeDIE) {
492 // We create children when the scope DIE is not null.
493 SmallVector<std::unique_ptr<DIE>, 8> Children;
494 if (DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children))
495 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
498 for (auto &I : Children)
499 ScopeDIE.addChild(std::move(I));
502 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
503 LexicalScope *Scope) {
504 assert(Scope && Scope->getScopeNode());
505 assert(Scope->isAbstractScope());
506 assert(!Scope->getInlinedAt());
508 DISubprogram SP(Scope->getScopeNode());
510 ProcessedSPNodes.insert(SP);
512 DIE *&AbsDef = AbstractSPDies[SP];
516 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
517 // was inlined from another compile unit.
518 DwarfCompileUnit &SPCU = *SPMap[SP];
521 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
522 // the important distinction that the DIDescriptor is not associated with the
523 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
524 // any). It could be refactored to some common utility function.
525 if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
526 ContextDIE = &SPCU.getUnitDie();
527 SPCU.getOrCreateSubprogramDIE(SPDecl);
529 ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
531 // Passing null as the associated DIDescriptor because the abstract definition
532 // shouldn't be found by lookup.
533 AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
535 SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
537 SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
538 createAndAddScopeChildren(SPCU, Scope, *AbsDef);
541 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
542 LexicalScope *Scope) {
543 assert(Scope && Scope->getScopeNode());
544 assert(!Scope->getInlinedAt());
545 assert(!Scope->isAbstractScope());
546 DISubprogram Sub(Scope->getScopeNode());
548 assert(Sub.isSubprogram());
550 ProcessedSPNodes.insert(Sub);
552 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
554 createAndAddScopeChildren(TheCU, Scope, ScopeDIE);
559 // Construct a DIE for this scope.
560 std::unique_ptr<DIE> DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
561 LexicalScope *Scope) {
562 if (!Scope || !Scope->getScopeNode())
565 DIScope DS(Scope->getScopeNode());
567 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
568 "Only handle inlined subprograms here, use "
569 "constructSubprogramScopeDIE for non-inlined "
572 SmallVector<std::unique_ptr<DIE>, 8> Children;
574 // We try to create the scope DIE first, then the children DIEs. This will
575 // avoid creating un-used children then removing them later when we find out
576 // the scope DIE is null.
577 std::unique_ptr<DIE> ScopeDIE;
578 if (Scope->getParent() && DS.isSubprogram()) {
579 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
582 // We create children when the scope DIE is not null.
583 createScopeChildrenDIE(TheCU, Scope, Children);
585 // Early exit when we know the scope DIE is going to be null.
586 if (isLexicalScopeDIENull(Scope))
589 // We create children here when we know the scope DIE is not going to be
590 // null and the children will be added to the scope DIE.
591 createScopeChildrenDIE(TheCU, Scope, Children);
593 // There is no need to emit empty lexical block DIE.
594 std::pair<ImportedEntityMap::const_iterator,
595 ImportedEntityMap::const_iterator> Range =
596 std::equal_range(ScopesWithImportedEntities.begin(),
597 ScopesWithImportedEntities.end(),
598 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
600 if (Children.empty() && Range.first == Range.second)
602 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
603 assert(ScopeDIE && "Scope DIE should not be null.");
604 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
606 constructImportedEntityDIE(TheCU, i->second, *ScopeDIE);
610 for (auto &I : Children)
611 ScopeDIE->addChild(std::move(I));
616 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
617 if (!GenerateGnuPubSections)
620 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
623 // Create new DwarfCompileUnit for the given metadata node with tag
624 // DW_TAG_compile_unit.
625 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
626 StringRef FN = DIUnit.getFilename();
627 CompilationDir = DIUnit.getDirectory();
629 auto OwnedUnit = make_unique<DwarfCompileUnit>(
630 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
631 DwarfCompileUnit &NewCU = *OwnedUnit;
632 DIE &Die = NewCU.getUnitDie();
633 InfoHolder.addUnit(std::move(OwnedUnit));
635 // LTO with assembly output shares a single line table amongst multiple CUs.
636 // To avoid the compilation directory being ambiguous, let the line table
637 // explicitly describe the directory of all files, never relying on the
638 // compilation directory.
639 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
640 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
641 NewCU.getUniqueID(), CompilationDir);
643 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
644 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
645 DIUnit.getLanguage());
646 NewCU.addString(Die, dwarf::DW_AT_name, FN);
648 if (!useSplitDwarf()) {
649 NewCU.initStmtList(DwarfLineSectionSym);
651 // If we're using split dwarf the compilation dir is going to be in the
652 // skeleton CU and so we don't need to duplicate it here.
653 if (!CompilationDir.empty())
654 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
656 addGnuPubAttributes(NewCU, Die);
659 if (DIUnit.isOptimized())
660 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
662 StringRef Flags = DIUnit.getFlags();
664 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
666 if (unsigned RVer = DIUnit.getRunTimeVersion())
667 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
668 dwarf::DW_FORM_data1, RVer);
673 if (useSplitDwarf()) {
674 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
675 DwarfInfoDWOSectionSym);
676 NewCU.setSkeleton(constructSkeletonCU(NewCU));
678 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
679 DwarfInfoSectionSym);
681 CUMap.insert(std::make_pair(DIUnit, &NewCU));
682 CUDieMap.insert(std::make_pair(&Die, &NewCU));
686 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
688 DIImportedEntity Module(N);
689 assert(Module.Verify());
690 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
691 D->addChild(constructImportedEntityDIE(TheCU, Module));
694 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
695 const MDNode *N, DIE &Context) {
696 DIImportedEntity Module(N);
697 assert(Module.Verify());
698 Context.addChild(constructImportedEntityDIE(TheCU, Module));
702 DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
703 const DIImportedEntity &Module) {
704 assert(Module.Verify() &&
705 "Use one of the MDNode * overloads to handle invalid metadata");
706 std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
707 TheCU.insertDIE(Module, IMDie.get());
709 DIDescriptor Entity = resolve(Module.getEntity());
710 if (Entity.isNameSpace())
711 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
712 else if (Entity.isSubprogram())
713 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
714 else if (Entity.isType())
715 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
717 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);
730 // Emit all Dwarf sections that should come prior to the content. Create
731 // global DIEs and emit initial debug info sections. This is invoked by
732 // the target AsmPrinter.
733 void DwarfDebug::beginModule() {
734 if (DisableDebugInfoPrinting)
737 const Module *M = MMI->getModule();
739 FunctionDIs = makeSubprogramMap(*M);
741 // If module has named metadata anchors then use them, otherwise scan the
742 // module using debug info finder to collect debug info.
743 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
746 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
748 // Emit initial sections so we can reference labels later.
751 SingleCU = CU_Nodes->getNumOperands() == 1;
753 for (MDNode *N : CU_Nodes->operands()) {
754 DICompileUnit CUNode(N);
755 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
756 DIArray ImportedEntities = CUNode.getImportedEntities();
757 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
758 ScopesWithImportedEntities.push_back(std::make_pair(
759 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
760 ImportedEntities.getElement(i)));
761 std::sort(ScopesWithImportedEntities.begin(),
762 ScopesWithImportedEntities.end(), less_first());
763 DIArray GVs = CUNode.getGlobalVariables();
764 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
765 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
766 DIArray SPs = CUNode.getSubprograms();
767 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
768 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
769 DIArray EnumTypes = CUNode.getEnumTypes();
770 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
771 DIType Ty(EnumTypes.getElement(i));
772 // The enum types array by design contains pointers to
773 // MDNodes rather than DIRefs. Unique them here.
774 DIType UniqueTy(resolve(Ty.getRef()));
775 CU.getOrCreateTypeDIE(UniqueTy);
777 DIArray RetainedTypes = CUNode.getRetainedTypes();
778 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
779 DIType Ty(RetainedTypes.getElement(i));
780 // The retained types array by design contains pointers to
781 // MDNodes rather than DIRefs. Unique them here.
782 DIType UniqueTy(resolve(Ty.getRef()));
783 CU.getOrCreateTypeDIE(UniqueTy);
785 // Emit imported_modules last so that the relevant context is already
787 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
788 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
791 // Tell MMI that we have debug info.
792 MMI->setDebugInfoAvailability(true);
794 // Prime section data.
795 SectionMap[Asm->getObjFileLowering().getTextSection()];
798 void DwarfDebug::finishVariableDefinitions() {
799 for (const auto &Var : ConcreteVariables) {
800 DIE *VariableDie = Var->getDIE();
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 attachLowHighPC(U, U.getUnitDie(), Range.getStart(), Range.getEnd());
961 // Compute DIE offsets and sizes.
962 InfoHolder.computeSizeAndOffsets();
964 SkeletonHolder.computeSizeAndOffsets();
967 void DwarfDebug::endSections() {
968 // Filter labels by section.
969 for (const SymbolCU &SCU : ArangeLabels) {
970 if (SCU.Sym->isInSection()) {
971 // Make a note of this symbol and it's section.
972 const MCSection *Section = &SCU.Sym->getSection();
973 if (!Section->getKind().isMetadata())
974 SectionMap[Section].push_back(SCU);
976 // Some symbols (e.g. common/bss on mach-o) can have no section but still
977 // appear in the output. This sucks as we rely on sections to build
978 // arange spans. We can do it without, but it's icky.
979 SectionMap[nullptr].push_back(SCU);
983 // Build a list of sections used.
984 std::vector<const MCSection *> Sections;
985 for (const auto &it : SectionMap) {
986 const MCSection *Section = it.first;
987 Sections.push_back(Section);
990 // Sort the sections into order.
991 // This is only done to ensure consistent output order across different runs.
992 std::sort(Sections.begin(), Sections.end(), SectionSort);
994 // Add terminating symbols for each section.
995 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
996 const MCSection *Section = Sections[ID];
997 MCSymbol *Sym = nullptr;
1000 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1001 // if we know the section name up-front. For user-created sections, the
1002 // resulting label may not be valid to use as a label. (section names can
1003 // use a greater set of characters on some systems)
1004 Sym = Asm->GetTempSymbol("debug_end", ID);
1005 Asm->OutStreamer.SwitchSection(Section);
1006 Asm->OutStreamer.EmitLabel(Sym);
1009 // Insert a final terminator.
1010 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1014 // Emit all Dwarf sections that should come after the content.
1015 void DwarfDebug::endModule() {
1016 assert(CurFn == nullptr);
1017 assert(CurMI == nullptr);
1022 // End any existing sections.
1023 // TODO: Does this need to happen?
1026 // Finalize the debug info for the module.
1027 finalizeModuleInfo();
1031 // Emit all the DIEs into a debug info section.
1034 // Corresponding abbreviations into a abbrev section.
1035 emitAbbreviations();
1037 // Emit info into a debug aranges section.
1038 if (GenerateARangeSection)
1041 // Emit info into a debug ranges section.
1044 if (useSplitDwarf()) {
1047 emitDebugAbbrevDWO();
1050 // Emit DWO addresses.
1051 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1053 // Emit info into a debug loc section.
1056 // Emit info into the dwarf accelerator table sections.
1057 if (useDwarfAccelTables()) {
1060 emitAccelNamespaces();
1064 // Emit the pubnames and pubtypes sections if requested.
1065 if (HasDwarfPubSections) {
1066 emitDebugPubNames(GenerateGnuPubSections);
1067 emitDebugPubTypes(GenerateGnuPubSections);
1072 AbstractVariables.clear();
1074 // Reset these for the next Module if we have one.
1078 // Find abstract variable, if any, associated with Var.
1079 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1080 DIVariable &Cleansed) {
1081 LLVMContext &Ctx = DV->getContext();
1082 // More then one inlined variable corresponds to one abstract variable.
1083 // FIXME: This duplication of variables when inlining should probably be
1084 // removed. It's done to allow each DIVariable to describe its location
1085 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1086 // make it accurate then remove this duplication/cleansing stuff.
1087 Cleansed = cleanseInlinedVariable(DV, Ctx);
1088 auto I = AbstractVariables.find(Cleansed);
1089 if (I != AbstractVariables.end())
1090 return I->second.get();
1094 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1095 DIVariable Cleansed;
1096 return getExistingAbstractVariable(DV, Cleansed);
1099 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1100 LexicalScope *Scope) {
1101 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1102 addScopeVariable(Scope, AbsDbgVariable.get());
1103 AbstractVariables[Var] = std::move(AbsDbgVariable);
1106 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1107 const MDNode *ScopeNode) {
1108 DIVariable Cleansed = DV;
1109 if (getExistingAbstractVariable(DV, Cleansed))
1112 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1116 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1117 const MDNode *ScopeNode) {
1118 DIVariable Cleansed = DV;
1119 if (getExistingAbstractVariable(DV, Cleansed))
1122 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1123 createAbstractVariable(Cleansed, Scope);
1126 // If Var is a current function argument then add it to CurrentFnArguments list.
1127 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1128 if (!LScopes.isCurrentFunctionScope(Scope))
1130 DIVariable DV = Var->getVariable();
1131 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1133 unsigned ArgNo = DV.getArgNumber();
1137 size_t Size = CurrentFnArguments.size();
1139 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1140 // llvm::Function argument size is not good indicator of how many
1141 // arguments does the function have at source level.
1143 CurrentFnArguments.resize(ArgNo * 2);
1144 assert(!CurrentFnArguments[ArgNo - 1]);
1145 CurrentFnArguments[ArgNo - 1] = Var;
1149 // Collect variable information from side table maintained by MMI.
1150 void DwarfDebug::collectVariableInfoFromMMITable(
1151 SmallPtrSetImpl<const MDNode *> &Processed) {
1152 for (const auto &VI : MMI->getVariableDbgInfo()) {
1155 Processed.insert(VI.Var);
1156 DIVariable DV(VI.Var);
1157 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1159 // If variable scope is not found then skip this variable.
1163 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1164 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1165 DbgVariable *RegVar = ConcreteVariables.back().get();
1166 RegVar->setFrameIndex(VI.Slot);
1167 addScopeVariable(Scope, RegVar);
1171 // Get .debug_loc entry for the instruction range starting at MI.
1172 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1173 const MDNode *Var = MI->getDebugVariable();
1175 assert(MI->getNumOperands() == 3);
1176 if (MI->getOperand(0).isReg()) {
1177 MachineLocation MLoc;
1178 // If the second operand is an immediate, this is a
1179 // register-indirect address.
1180 if (!MI->getOperand(1).isImm())
1181 MLoc.set(MI->getOperand(0).getReg());
1183 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1184 return DebugLocEntry::Value(Var, MLoc);
1186 if (MI->getOperand(0).isImm())
1187 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1188 if (MI->getOperand(0).isFPImm())
1189 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1190 if (MI->getOperand(0).isCImm())
1191 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1193 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1196 /// Determine whether two variable pieces overlap.
1197 static bool piecesOverlap(DIVariable P1, DIVariable P2) {
1198 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1200 unsigned l1 = P1.getPieceOffset();
1201 unsigned l2 = P2.getPieceOffset();
1202 unsigned r1 = l1 + P1.getPieceSize();
1203 unsigned r2 = l2 + P2.getPieceSize();
1204 // True where [l1,r1[ and [r1,r2[ overlap.
1205 return (l1 < r2) && (l2 < r1);
1208 /// Build the location list for all DBG_VALUEs in the function that
1209 /// describe the same variable. If the ranges of several independent
1210 /// pieces of the same variable overlap partially, split them up and
1211 /// combine the ranges. The resulting DebugLocEntries are will have
1212 /// strict monotonically increasing begin addresses and will never
1217 // Ranges History [var, loc, piece ofs size]
1218 // 0 | [x, (reg0, piece 0, 32)]
1219 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1221 // 3 | [clobber reg0]
1222 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1226 // [0-1] [x, (reg0, piece 0, 32)]
1227 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1228 // [3-4] [x, (reg1, piece 32, 32)]
1229 // [4- ] [x, (mem, piece 0, 64)]
1231 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1232 const DbgValueHistoryMap::InstrRanges &Ranges) {
1233 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
1235 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1236 const MachineInstr *Begin = I->first;
1237 const MachineInstr *End = I->second;
1238 assert(Begin->isDebugValue() && "Invalid History entry");
1240 // Check if a variable is inaccessible in this range.
1241 if (Begin->getNumOperands() > 1 &&
1242 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
1247 // If this piece overlaps with any open ranges, truncate them.
1248 DIVariable DIVar = Begin->getDebugVariable();
1249 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
1250 [&](DebugLocEntry::Value R) {
1251 return piecesOverlap(DIVar, R.getVariable());
1253 OpenRanges.erase(Last, OpenRanges.end());
1255 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1256 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1258 const MCSymbol *EndLabel;
1260 EndLabel = getLabelAfterInsn(End);
1261 else if (std::next(I) == Ranges.end())
1262 EndLabel = FunctionEndSym;
1264 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1265 assert(EndLabel && "Forgot label after instruction ending a range!");
1267 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1269 auto Value = getDebugLocValue(Begin);
1270 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1271 bool couldMerge = false;
1273 // If this is a piece, it may belong to the current DebugLocEntry.
1274 if (DIVar.isVariablePiece()) {
1275 // Add this value to the list of open ranges.
1276 OpenRanges.push_back(Value);
1278 // Attempt to add the piece to the last entry.
1279 if (!DebugLoc.empty())
1280 if (DebugLoc.back().MergeValues(Loc))
1285 // Need to add a new DebugLocEntry. Add all values from still
1286 // valid non-overlapping pieces.
1287 if (OpenRanges.size())
1288 Loc.addValues(OpenRanges);
1290 DebugLoc.push_back(std::move(Loc));
1293 // Attempt to coalesce the ranges of two otherwise identical
1295 auto CurEntry = DebugLoc.rbegin();
1296 auto PrevEntry = std::next(CurEntry);
1297 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1298 DebugLoc.pop_back();
1300 DEBUG(dbgs() << "Values:\n";
1301 for (auto Value : CurEntry->getValues())
1302 Value.getVariable()->dump();
1303 dbgs() << "-----\n");
1308 // Find variables for each lexical scope.
1310 DwarfDebug::collectVariableInfo(SmallPtrSetImpl<const MDNode *> &Processed) {
1311 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1312 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1314 // Grab the variable info that was squirreled away in the MMI side-table.
1315 collectVariableInfoFromMMITable(Processed);
1317 for (const auto &I : DbgValues) {
1318 DIVariable DV(I.first);
1319 if (Processed.count(DV))
1322 // Instruction ranges, specifying where DV is accessible.
1323 const auto &Ranges = I.second;
1327 LexicalScope *Scope = nullptr;
1328 if (MDNode *IA = DV.getInlinedAt()) {
1329 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1330 Scope = LScopes.findInlinedScope(DebugLoc::get(
1331 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1333 Scope = LScopes.findLexicalScope(DV.getContext());
1334 // If variable scope is not found then skip this variable.
1338 Processed.insert(getEntireVariable(DV));
1339 const MachineInstr *MInsn = Ranges.front().first;
1340 assert(MInsn->isDebugValue() && "History must begin with debug value");
1341 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1342 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1343 DbgVariable *RegVar = ConcreteVariables.back().get();
1344 addScopeVariable(Scope, RegVar);
1346 // Check if the first DBG_VALUE is valid for the rest of the function.
1347 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1350 // Handle multiple DBG_VALUE instructions describing one variable.
1351 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1353 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1354 DebugLocList &LocList = DotDebugLocEntries.back();
1357 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1359 // Build the location list for this variable.
1360 buildLocationList(LocList.List, Ranges);
1363 // Collect info for variables that were optimized out.
1364 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1365 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1366 DIVariable DV(Variables.getElement(i));
1367 assert(DV.isVariable());
1368 if (!Processed.insert(DV))
1370 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1371 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1372 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1373 addScopeVariable(Scope, ConcreteVariables.back().get());
1378 // Return Label preceding the instruction.
1379 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1380 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1381 assert(Label && "Didn't insert label before instruction");
1385 // Return Label immediately following the instruction.
1386 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1387 return LabelsAfterInsn.lookup(MI);
1390 // Process beginning of an instruction.
1391 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1392 assert(CurMI == nullptr);
1394 // Check if source location changes, but ignore DBG_VALUE locations.
1395 if (!MI->isDebugValue()) {
1396 DebugLoc DL = MI->getDebugLoc();
1397 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1400 if (DL == PrologEndLoc) {
1401 Flags |= DWARF2_FLAG_PROLOGUE_END;
1402 PrologEndLoc = DebugLoc();
1404 if (PrologEndLoc.isUnknown())
1405 Flags |= DWARF2_FLAG_IS_STMT;
1407 if (!DL.isUnknown()) {
1408 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1409 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1411 recordSourceLine(0, 0, nullptr, 0);
1415 // Insert labels where requested.
1416 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1417 LabelsBeforeInsn.find(MI);
1420 if (I == LabelsBeforeInsn.end())
1423 // Label already assigned.
1428 PrevLabel = MMI->getContext().CreateTempSymbol();
1429 Asm->OutStreamer.EmitLabel(PrevLabel);
1431 I->second = PrevLabel;
1434 // Process end of an instruction.
1435 void DwarfDebug::endInstruction() {
1436 assert(CurMI != nullptr);
1437 // Don't create a new label after DBG_VALUE instructions.
1438 // They don't generate code.
1439 if (!CurMI->isDebugValue())
1440 PrevLabel = nullptr;
1442 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1443 LabelsAfterInsn.find(CurMI);
1447 if (I == LabelsAfterInsn.end())
1450 // Label already assigned.
1454 // We need a label after this instruction.
1456 PrevLabel = MMI->getContext().CreateTempSymbol();
1457 Asm->OutStreamer.EmitLabel(PrevLabel);
1459 I->second = PrevLabel;
1462 // Each LexicalScope has first instruction and last instruction to mark
1463 // beginning and end of a scope respectively. Create an inverse map that list
1464 // scopes starts (and ends) with an instruction. One instruction may start (or
1465 // end) multiple scopes. Ignore scopes that are not reachable.
1466 void DwarfDebug::identifyScopeMarkers() {
1467 SmallVector<LexicalScope *, 4> WorkList;
1468 WorkList.push_back(LScopes.getCurrentFunctionScope());
1469 while (!WorkList.empty()) {
1470 LexicalScope *S = WorkList.pop_back_val();
1472 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1473 if (!Children.empty())
1474 WorkList.append(Children.begin(), Children.end());
1476 if (S->isAbstractScope())
1479 for (const InsnRange &R : S->getRanges()) {
1480 assert(R.first && "InsnRange does not have first instruction!");
1481 assert(R.second && "InsnRange does not have second instruction!");
1482 requestLabelBeforeInsn(R.first);
1483 requestLabelAfterInsn(R.second);
1488 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1489 // First known non-DBG_VALUE and non-frame setup location marks
1490 // the beginning of the function body.
1491 for (const auto &MBB : *MF)
1492 for (const auto &MI : MBB)
1493 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1494 !MI.getDebugLoc().isUnknown())
1495 return MI.getDebugLoc();
1499 // Gather pre-function debug information. Assumes being called immediately
1500 // after the function entry point has been emitted.
1501 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1504 // If there's no debug info for the function we're not going to do anything.
1505 if (!MMI->hasDebugInfo())
1508 auto DI = FunctionDIs.find(MF->getFunction());
1509 if (DI == FunctionDIs.end())
1512 // Grab the lexical scopes for the function, if we don't have any of those
1513 // then we're not going to be able to do anything.
1514 LScopes.initialize(*MF);
1515 if (LScopes.empty())
1518 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1520 // Make sure that each lexical scope will have a begin/end label.
1521 identifyScopeMarkers();
1523 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1524 // belongs to so that we add to the correct per-cu line table in the
1526 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1527 // FnScope->getScopeNode() and DI->second should represent the same function,
1528 // though they may not be the same MDNode due to inline functions merged in
1529 // LTO where the debug info metadata still differs (either due to distinct
1530 // written differences - two versions of a linkonce_odr function
1531 // written/copied into two separate files, or some sub-optimal metadata that
1532 // isn't structurally identical (see: file path/name info from clang, which
1533 // includes the directory of the cpp file being built, even when the file name
1534 // is absolute (such as an <> lookup header)))
1535 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1536 assert(TheCU && "Unable to find compile unit!");
1537 if (Asm->OutStreamer.hasRawTextSupport())
1538 // Use a single line table if we are generating assembly.
1539 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1541 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1543 // Emit a label for the function so that we have a beginning address.
1544 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1545 // Assumes in correct section after the entry point.
1546 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1548 // Calculate history for local variables.
1549 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1552 // Request labels for the full history.
1553 for (const auto &I : DbgValues) {
1554 const auto &Ranges = I.second;
1558 // The first mention of a function argument gets the FunctionBeginSym
1559 // label, so arguments are visible when breaking at function entry.
1560 DIVariable DV(Ranges.front().first->getDebugVariable());
1561 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1562 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1563 if (!DV.isVariablePiece())
1564 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1566 // Mark all non-overlapping initial pieces.
1567 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1568 DIVariable Piece = I->first->getDebugVariable();
1569 if (std::all_of(Ranges.begin(), I,
1570 [&](DbgValueHistoryMap::InstrRange Pred){
1571 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1573 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1580 for (const auto &Range : Ranges) {
1581 requestLabelBeforeInsn(Range.first);
1583 requestLabelAfterInsn(Range.second);
1587 PrevInstLoc = DebugLoc();
1588 PrevLabel = FunctionBeginSym;
1590 // Record beginning of function.
1591 PrologEndLoc = findPrologueEndLoc(MF);
1592 if (!PrologEndLoc.isUnknown()) {
1593 DebugLoc FnStartDL =
1594 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1596 FnStartDL.getLine(), FnStartDL.getCol(),
1597 FnStartDL.getScope(MF->getFunction()->getContext()),
1598 // We'd like to list the prologue as "not statements" but GDB behaves
1599 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1600 DWARF2_FLAG_IS_STMT);
1604 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1605 if (addCurrentFnArgument(Var, LS))
1607 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1608 DIVariable DV = Var->getVariable();
1609 // Variables with positive arg numbers are parameters.
1610 if (unsigned ArgNum = DV.getArgNumber()) {
1611 // Keep all parameters in order at the start of the variable list to ensure
1612 // function types are correct (no out-of-order parameters)
1614 // This could be improved by only doing it for optimized builds (unoptimized
1615 // builds have the right order to begin with), searching from the back (this
1616 // would catch the unoptimized case quickly), or doing a binary search
1617 // rather than linear search.
1618 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1619 while (I != Vars.end()) {
1620 unsigned CurNum = (*I)->getVariable().getArgNumber();
1621 // A local (non-parameter) variable has been found, insert immediately
1625 // A later indexed parameter has been found, insert immediately before it.
1626 if (CurNum > ArgNum)
1630 Vars.insert(I, Var);
1634 Vars.push_back(Var);
1637 // Gather and emit post-function debug information.
1638 void DwarfDebug::endFunction(const MachineFunction *MF) {
1639 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1640 // though the beginFunction may not be called at all.
1641 // We should handle both cases.
1645 assert(CurFn == MF);
1646 assert(CurFn != nullptr);
1648 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1649 !FunctionDIs.count(MF->getFunction())) {
1650 // If we don't have a lexical scope for this function then there will
1651 // be a hole in the range information. Keep note of this by setting the
1652 // previously used section to nullptr.
1653 PrevSection = nullptr;
1659 // Define end label for subprogram.
1660 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1661 // Assumes in correct section after the entry point.
1662 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1664 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1665 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1667 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1668 collectVariableInfo(ProcessedVars);
1670 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1671 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1673 // Construct abstract scopes.
1674 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1675 DISubprogram SP(AScope->getScopeNode());
1676 assert(SP.isSubprogram());
1677 // Collect info for variables that were optimized out.
1678 DIArray Variables = SP.getVariables();
1679 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1680 DIVariable DV(Variables.getElement(i));
1681 assert(DV && DV.isVariable());
1682 if (!ProcessedVars.insert(DV))
1684 ensureAbstractVariableIsCreated(DV, DV.getContext());
1686 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1689 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1690 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1691 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1693 // Add the range of this function to the list of ranges for the CU.
1694 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1695 TheCU.addRange(std::move(Span));
1696 PrevSection = Asm->getCurrentSection();
1700 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1701 // DbgVariables except those that are also in AbstractVariables (since they
1702 // can be used cross-function)
1703 ScopeVariables.clear();
1704 CurrentFnArguments.clear();
1706 LabelsBeforeInsn.clear();
1707 LabelsAfterInsn.clear();
1708 PrevLabel = nullptr;
1712 // Register a source line with debug info. Returns the unique label that was
1713 // emitted and which provides correspondence to the source line list.
1714 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1719 unsigned Discriminator = 0;
1720 if (DIScope Scope = DIScope(S)) {
1721 assert(Scope.isScope());
1722 Fn = Scope.getFilename();
1723 Dir = Scope.getDirectory();
1724 if (Scope.isLexicalBlockFile())
1725 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1727 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1728 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1729 .getOrCreateSourceID(Fn, Dir);
1731 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1735 //===----------------------------------------------------------------------===//
1737 //===----------------------------------------------------------------------===//
1739 // Emit initial Dwarf sections with a label at the start of each one.
1740 void DwarfDebug::emitSectionLabels() {
1741 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1743 // Dwarf sections base addresses.
1744 DwarfInfoSectionSym =
1745 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1746 if (useSplitDwarf()) {
1747 DwarfInfoDWOSectionSym =
1748 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1749 DwarfTypesDWOSectionSym =
1750 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1752 DwarfAbbrevSectionSym =
1753 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1754 if (useSplitDwarf())
1755 DwarfAbbrevDWOSectionSym = emitSectionSym(
1756 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1757 if (GenerateARangeSection)
1758 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1760 DwarfLineSectionSym =
1761 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1762 if (GenerateGnuPubSections) {
1763 DwarfGnuPubNamesSectionSym =
1764 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1765 DwarfGnuPubTypesSectionSym =
1766 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1767 } else if (HasDwarfPubSections) {
1768 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1769 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1772 DwarfStrSectionSym =
1773 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1774 if (useSplitDwarf()) {
1775 DwarfStrDWOSectionSym =
1776 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1777 DwarfAddrSectionSym =
1778 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1779 DwarfDebugLocSectionSym =
1780 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1782 DwarfDebugLocSectionSym =
1783 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1784 DwarfDebugRangeSectionSym =
1785 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1788 // Recursively emits a debug information entry.
1789 void DwarfDebug::emitDIE(DIE &Die) {
1790 // Get the abbreviation for this DIE.
1791 const DIEAbbrev &Abbrev = Die.getAbbrev();
1793 // Emit the code (index) for the abbreviation.
1794 if (Asm->isVerbose())
1795 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1796 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1797 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1798 dwarf::TagString(Abbrev.getTag()));
1799 Asm->EmitULEB128(Abbrev.getNumber());
1801 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1802 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1804 // Emit the DIE attribute values.
1805 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1806 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1807 dwarf::Form Form = AbbrevData[i].getForm();
1808 assert(Form && "Too many attributes for DIE (check abbreviation)");
1810 if (Asm->isVerbose()) {
1811 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1812 if (Attr == dwarf::DW_AT_accessibility)
1813 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1814 cast<DIEInteger>(Values[i])->getValue()));
1817 // Emit an attribute using the defined form.
1818 Values[i]->EmitValue(Asm, Form);
1821 // Emit the DIE children if any.
1822 if (Abbrev.hasChildren()) {
1823 for (auto &Child : Die.getChildren())
1826 Asm->OutStreamer.AddComment("End Of Children Mark");
1831 // Emit the debug info section.
1832 void DwarfDebug::emitDebugInfo() {
1833 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1835 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1838 // Emit the abbreviation section.
1839 void DwarfDebug::emitAbbreviations() {
1840 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1842 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1845 // Emit the last address of the section and the end of the line matrix.
1846 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1847 // Define last address of section.
1848 Asm->OutStreamer.AddComment("Extended Op");
1851 Asm->OutStreamer.AddComment("Op size");
1852 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1853 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1854 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1856 Asm->OutStreamer.AddComment("Section end label");
1858 Asm->OutStreamer.EmitSymbolValue(
1859 Asm->GetTempSymbol("section_end", SectionEnd),
1860 Asm->getDataLayout().getPointerSize());
1862 // Mark end of matrix.
1863 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1869 // Emit visible names into a hashed accelerator table section.
1870 void DwarfDebug::emitAccelNames() {
1871 AccelNames.FinalizeTable(Asm, "Names");
1872 Asm->OutStreamer.SwitchSection(
1873 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1874 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1875 Asm->OutStreamer.EmitLabel(SectionBegin);
1877 // Emit the full data.
1878 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1881 // Emit objective C classes and categories into a hashed accelerator table
1883 void DwarfDebug::emitAccelObjC() {
1884 AccelObjC.FinalizeTable(Asm, "ObjC");
1885 Asm->OutStreamer.SwitchSection(
1886 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1887 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1888 Asm->OutStreamer.EmitLabel(SectionBegin);
1890 // Emit the full data.
1891 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1894 // Emit namespace dies into a hashed accelerator table.
1895 void DwarfDebug::emitAccelNamespaces() {
1896 AccelNamespace.FinalizeTable(Asm, "namespac");
1897 Asm->OutStreamer.SwitchSection(
1898 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1899 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1900 Asm->OutStreamer.EmitLabel(SectionBegin);
1902 // Emit the full data.
1903 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1906 // Emit type dies into a hashed accelerator table.
1907 void DwarfDebug::emitAccelTypes() {
1909 AccelTypes.FinalizeTable(Asm, "types");
1910 Asm->OutStreamer.SwitchSection(
1911 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1912 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1913 Asm->OutStreamer.EmitLabel(SectionBegin);
1915 // Emit the full data.
1916 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1919 // Public name handling.
1920 // The format for the various pubnames:
1922 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1923 // for the DIE that is named.
1925 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1926 // into the CU and the index value is computed according to the type of value
1927 // for the DIE that is named.
1929 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1930 // it's the offset within the debug_info/debug_types dwo section, however, the
1931 // reference in the pubname header doesn't change.
1933 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1934 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1936 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1938 // We could have a specification DIE that has our most of our knowledge,
1939 // look for that now.
1940 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1942 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1943 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1944 Linkage = dwarf::GIEL_EXTERNAL;
1945 } else if (Die->findAttribute(dwarf::DW_AT_external))
1946 Linkage = dwarf::GIEL_EXTERNAL;
1948 switch (Die->getTag()) {
1949 case dwarf::DW_TAG_class_type:
1950 case dwarf::DW_TAG_structure_type:
1951 case dwarf::DW_TAG_union_type:
1952 case dwarf::DW_TAG_enumeration_type:
1953 return dwarf::PubIndexEntryDescriptor(
1954 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1955 ? dwarf::GIEL_STATIC
1956 : dwarf::GIEL_EXTERNAL);
1957 case dwarf::DW_TAG_typedef:
1958 case dwarf::DW_TAG_base_type:
1959 case dwarf::DW_TAG_subrange_type:
1960 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1961 case dwarf::DW_TAG_namespace:
1962 return dwarf::GIEK_TYPE;
1963 case dwarf::DW_TAG_subprogram:
1964 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1965 case dwarf::DW_TAG_constant:
1966 case dwarf::DW_TAG_variable:
1967 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1968 case dwarf::DW_TAG_enumerator:
1969 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1970 dwarf::GIEL_STATIC);
1972 return dwarf::GIEK_NONE;
1976 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1978 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1979 const MCSection *PSec =
1980 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1981 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1983 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1986 void DwarfDebug::emitDebugPubSection(
1987 bool GnuStyle, const MCSection *PSec, StringRef Name,
1988 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1989 for (const auto &NU : CUMap) {
1990 DwarfCompileUnit *TheU = NU.second;
1992 const auto &Globals = (TheU->*Accessor)();
1994 if (Globals.empty())
1997 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1999 unsigned ID = TheU->getUniqueID();
2001 // Start the dwarf pubnames section.
2002 Asm->OutStreamer.SwitchSection(PSec);
2005 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2006 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2007 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2008 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2010 Asm->OutStreamer.EmitLabel(BeginLabel);
2012 Asm->OutStreamer.AddComment("DWARF Version");
2013 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2015 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2016 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2018 Asm->OutStreamer.AddComment("Compilation Unit Length");
2019 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2021 // Emit the pubnames for this compilation unit.
2022 for (const auto &GI : Globals) {
2023 const char *Name = GI.getKeyData();
2024 const DIE *Entity = GI.second;
2026 Asm->OutStreamer.AddComment("DIE offset");
2027 Asm->EmitInt32(Entity->getOffset());
2030 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2031 Asm->OutStreamer.AddComment(
2032 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2033 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2034 Asm->EmitInt8(Desc.toBits());
2037 Asm->OutStreamer.AddComment("External Name");
2038 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2041 Asm->OutStreamer.AddComment("End Mark");
2043 Asm->OutStreamer.EmitLabel(EndLabel);
2047 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2048 const MCSection *PSec =
2049 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2050 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2052 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2055 // Emit visible names into a debug str section.
2056 void DwarfDebug::emitDebugStr() {
2057 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2058 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2061 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2062 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2063 const DITypeIdentifierMap &Map,
2064 ArrayRef<DebugLocEntry::Value> Values) {
2065 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
2066 return P.isVariablePiece();
2067 }) && "all values are expected to be pieces");
2068 assert(std::is_sorted(Values.begin(), Values.end()) &&
2069 "pieces are expected to be sorted");
2071 unsigned Offset = 0;
2072 for (auto Piece : Values) {
2073 DIVariable Var = Piece.getVariable();
2074 unsigned PieceOffset = Var.getPieceOffset();
2075 unsigned PieceSize = Var.getPieceSize();
2076 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
2077 if (Offset < PieceOffset) {
2078 // The DWARF spec seriously mandates pieces with no locations for gaps.
2079 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2080 Offset += PieceOffset-Offset;
2083 Offset += PieceSize;
2085 const unsigned SizeOfByte = 8;
2086 assert(!Var.isIndirect() && "indirect address for piece");
2088 unsigned VarSize = Var.getSizeInBits(Map);
2089 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2090 && "piece is larger than or outside of variable");
2091 assert(PieceSize*SizeOfByte != VarSize
2092 && "piece covers entire variable");
2094 if (Piece.isLocation() && Piece.getLoc().isReg())
2095 Asm->EmitDwarfRegOpPiece(Streamer,
2097 PieceSize*SizeOfByte);
2099 emitDebugLocValue(Streamer, Piece);
2100 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2106 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2107 const DebugLocEntry &Entry) {
2108 const DebugLocEntry::Value Value = Entry.getValues()[0];
2109 if (Value.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 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2484 // compile units that would normally be in debug_info.
2485 void DwarfDebug::emitDebugInfoDWO() {
2486 assert(useSplitDwarf() && "No split dwarf debug info?");
2487 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2488 // emit relocations into the dwo file.
2489 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2492 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2493 // abbreviations for the .debug_info.dwo section.
2494 void DwarfDebug::emitDebugAbbrevDWO() {
2495 assert(useSplitDwarf() && "No split dwarf?");
2496 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2499 void DwarfDebug::emitDebugLineDWO() {
2500 assert(useSplitDwarf() && "No split dwarf?");
2501 Asm->OutStreamer.SwitchSection(
2502 Asm->getObjFileLowering().getDwarfLineDWOSection());
2503 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2506 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2507 // string section and is identical in format to traditional .debug_str
2509 void DwarfDebug::emitDebugStrDWO() {
2510 assert(useSplitDwarf() && "No split dwarf?");
2511 const MCSection *OffSec =
2512 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2513 const MCSymbol *StrSym = DwarfStrSectionSym;
2514 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2518 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2519 if (!useSplitDwarf())
2522 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2523 return &SplitTypeUnitFileTable;
2526 static uint64_t makeTypeSignature(StringRef Identifier) {
2528 Hash.update(Identifier);
2529 // ... take the least significant 8 bytes and return those. Our MD5
2530 // implementation always returns its results in little endian, swap bytes
2532 MD5::MD5Result Result;
2534 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2537 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2538 StringRef Identifier, DIE &RefDie,
2539 DICompositeType CTy) {
2540 // Fast path if we're building some type units and one has already used the
2541 // address pool we know we're going to throw away all this work anyway, so
2542 // don't bother building dependent types.
2543 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2546 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2548 CU.addDIETypeSignature(RefDie, *TU);
2552 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2553 AddrPool.resetUsedFlag();
2555 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2556 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2557 this, &InfoHolder, getDwoLineTable(CU));
2558 DwarfTypeUnit &NewTU = *OwnedUnit;
2559 DIE &UnitDie = NewTU.getUnitDie();
2561 TypeUnitsUnderConstruction.push_back(
2562 std::make_pair(std::move(OwnedUnit), CTy));
2564 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2567 uint64_t Signature = makeTypeSignature(Identifier);
2568 NewTU.setTypeSignature(Signature);
2570 if (useSplitDwarf())
2571 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2572 DwarfTypesDWOSectionSym);
2574 CU.applyStmtList(UnitDie);
2576 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2579 NewTU.setType(NewTU.createTypeDIE(CTy));
2582 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2583 TypeUnitsUnderConstruction.clear();
2585 // Types referencing entries in the address table cannot be placed in type
2587 if (AddrPool.hasBeenUsed()) {
2589 // Remove all the types built while building this type.
2590 // This is pessimistic as some of these types might not be dependent on
2591 // the type that used an address.
2592 for (const auto &TU : TypeUnitsToAdd)
2593 DwarfTypeUnits.erase(TU.second);
2595 // Construct this type in the CU directly.
2596 // This is inefficient because all the dependent types will be rebuilt
2597 // from scratch, including building them in type units, discovering that
2598 // they depend on addresses, throwing them out and rebuilding them.
2599 CU.constructTypeDIE(RefDie, CTy);
2603 // If the type wasn't dependent on fission addresses, finish adding the type
2604 // and all its dependent types.
2605 for (auto &TU : TypeUnitsToAdd)
2606 InfoHolder.addUnit(std::move(TU.first));
2608 CU.addDIETypeSignature(RefDie, NewTU);
2611 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2612 const MCSymbol *Begin, const MCSymbol *End) {
2613 assert(Begin && "Begin label should not be null!");
2614 assert(End && "End label should not be null!");
2615 assert(Begin->isDefined() && "Invalid starting label");
2616 assert(End->isDefined() && "Invalid end label");
2618 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2619 if (DwarfVersion < 4)
2620 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2622 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2625 // Accelerator table mutators - add each name along with its companion
2626 // DIE to the proper table while ensuring that the name that we're going
2627 // to reference is in the string table. We do this since the names we
2628 // add may not only be identical to the names in the DIE.
2629 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2630 if (!useDwarfAccelTables())
2632 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2636 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2637 if (!useDwarfAccelTables())
2639 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2643 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2644 if (!useDwarfAccelTables())
2646 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2650 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2651 if (!useDwarfAccelTables())
2653 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),