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"
53 #define DEBUG_TYPE "dwarfdebug"
56 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
57 cl::desc("Disable debug info printing"));
59 static cl::opt<bool> UnknownLocations(
60 "use-unknown-locations", cl::Hidden,
61 cl::desc("Make an absence of debug location information explicit."),
65 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
66 cl::desc("Generate GNU-style pubnames and pubtypes"),
69 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
71 cl::desc("Generate dwarf aranges"),
75 enum DefaultOnOff { Default, Enable, Disable };
78 static cl::opt<DefaultOnOff>
79 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
80 cl::desc("Output prototype dwarf accelerator tables."),
81 cl::values(clEnumVal(Default, "Default for platform"),
82 clEnumVal(Enable, "Enabled"),
83 clEnumVal(Disable, "Disabled"), clEnumValEnd),
86 static cl::opt<DefaultOnOff>
87 SplitDwarf("split-dwarf", cl::Hidden,
88 cl::desc("Output DWARF5 split debug info."),
89 cl::values(clEnumVal(Default, "Default for platform"),
90 clEnumVal(Enable, "Enabled"),
91 clEnumVal(Disable, "Disabled"), clEnumValEnd),
94 static cl::opt<DefaultOnOff>
95 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
96 cl::desc("Generate DWARF pubnames and pubtypes sections"),
97 cl::values(clEnumVal(Default, "Default for platform"),
98 clEnumVal(Enable, "Enabled"),
99 clEnumVal(Disable, "Disabled"), clEnumValEnd),
102 static const char *const DWARFGroupName = "DWARF Emission";
103 static const char *const DbgTimerName = "DWARF Debug Writer";
105 //===----------------------------------------------------------------------===//
107 /// resolve - Look in the DwarfDebug map for the MDNode that
108 /// corresponds to the reference.
109 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
110 return DD->resolve(Ref);
113 bool DbgVariable::isBlockByrefVariable() const {
114 assert(Var.isVariable() && "Invalid complex DbgVariable!");
115 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
118 DIType DbgVariable::getType() const {
119 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
120 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
121 // addresses instead.
122 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
123 /* Byref variables, in Blocks, are declared by the programmer as
124 "SomeType VarName;", but the compiler creates a
125 __Block_byref_x_VarName struct, and gives the variable VarName
126 either the struct, or a pointer to the struct, as its type. This
127 is necessary for various behind-the-scenes things the compiler
128 needs to do with by-reference variables in blocks.
130 However, as far as the original *programmer* is concerned, the
131 variable should still have type 'SomeType', as originally declared.
133 The following function dives into the __Block_byref_x_VarName
134 struct to find the original type of the variable. This will be
135 passed back to the code generating the type for the Debug
136 Information Entry for the variable 'VarName'. 'VarName' will then
137 have the original type 'SomeType' in its debug information.
139 The original type 'SomeType' will be the type of the field named
140 'VarName' inside the __Block_byref_x_VarName struct.
142 NOTE: In order for this to not completely fail on the debugger
143 side, the Debug Information Entry for the variable VarName needs to
144 have a DW_AT_location that tells the debugger how to unwind through
145 the pointers and __Block_byref_x_VarName struct to find the actual
146 value of the variable. The function addBlockByrefType does this. */
148 uint16_t tag = Ty.getTag();
150 if (tag == dwarf::DW_TAG_pointer_type)
151 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
153 DIArray Elements = DICompositeType(subType).getElements();
154 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
155 DIDerivedType DT(Elements.getElement(i));
156 if (getName() == DT.getName())
157 return (resolve(DT.getTypeDerivedFrom()));
163 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
164 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
165 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
166 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
168 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
169 : Asm(A), MMI(Asm->MMI), FirstCU(nullptr), PrevLabel(nullptr),
170 GlobalRangeCount(0), InfoHolder(A, "info_string", DIEValueAllocator),
171 UsedNonDefaultText(false),
172 SkeletonHolder(A, "skel_string", DIEValueAllocator),
173 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
174 dwarf::DW_FORM_data4)),
175 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
176 dwarf::DW_FORM_data4)),
177 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
178 dwarf::DW_FORM_data4)),
179 AccelTypes(TypeAtoms) {
181 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = nullptr;
182 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = nullptr;
183 DwarfLineSectionSym = nullptr;
184 DwarfAddrSectionSym = nullptr;
185 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = nullptr;
186 FunctionBeginSym = FunctionEndSym = nullptr;
190 // Turn on accelerator tables for Darwin by default, pubnames by
191 // default for non-Darwin, and handle split dwarf.
192 bool IsDarwin = Triple(A->getTargetTriple()).isOSDarwin();
194 if (DwarfAccelTables == Default)
195 HasDwarfAccelTables = IsDarwin;
197 HasDwarfAccelTables = DwarfAccelTables == Enable;
199 if (SplitDwarf == Default)
200 HasSplitDwarf = false;
202 HasSplitDwarf = SplitDwarf == Enable;
204 if (DwarfPubSections == Default)
205 HasDwarfPubSections = !IsDarwin;
207 HasDwarfPubSections = DwarfPubSections == Enable;
209 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
210 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
211 : MMI->getModule()->getDwarfVersion();
213 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
216 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
221 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
222 DwarfDebug::~DwarfDebug() { }
224 // Switch to the specified MCSection and emit an assembler
225 // temporary label to it if SymbolStem is specified.
226 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
227 const char *SymbolStem = nullptr) {
228 Asm->OutStreamer.SwitchSection(Section);
232 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
233 Asm->OutStreamer.EmitLabel(TmpSym);
237 static bool isObjCClass(StringRef Name) {
238 return Name.startswith("+") || Name.startswith("-");
241 static bool hasObjCCategory(StringRef Name) {
242 if (!isObjCClass(Name))
245 return Name.find(") ") != StringRef::npos;
248 static void getObjCClassCategory(StringRef In, StringRef &Class,
249 StringRef &Category) {
250 if (!hasObjCCategory(In)) {
251 Class = In.slice(In.find('[') + 1, In.find(' '));
256 Class = In.slice(In.find('[') + 1, In.find('('));
257 Category = In.slice(In.find('[') + 1, In.find(' '));
261 static StringRef getObjCMethodName(StringRef In) {
262 return In.slice(In.find(' ') + 1, In.find(']'));
265 // Helper for sorting sections into a stable output order.
266 static bool SectionSort(const MCSection *A, const MCSection *B) {
267 std::string LA = (A ? A->getLabelBeginName() : "");
268 std::string LB = (B ? B->getLabelBeginName() : "");
272 // Add the various names to the Dwarf accelerator table names.
273 // TODO: Determine whether or not we should add names for programs
274 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
275 // is only slightly different than the lookup of non-standard ObjC names.
276 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
277 if (!SP.isDefinition())
279 addAccelName(SP.getName(), Die);
281 // If the linkage name is different than the name, go ahead and output
282 // that as well into the name table.
283 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
284 addAccelName(SP.getLinkageName(), Die);
286 // If this is an Objective-C selector name add it to the ObjC accelerator
288 if (isObjCClass(SP.getName())) {
289 StringRef Class, Category;
290 getObjCClassCategory(SP.getName(), Class, Category);
291 addAccelObjC(Class, Die);
293 addAccelObjC(Category, Die);
294 // Also add the base method name to the name table.
295 addAccelName(getObjCMethodName(SP.getName()), Die);
299 /// isSubprogramContext - Return true if Context is either a subprogram
300 /// or another context nested inside a subprogram.
301 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
304 DIDescriptor D(Context);
305 if (D.isSubprogram())
308 return isSubprogramContext(resolve(DIType(Context).getContext()));
312 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
313 // and DW_AT_high_pc attributes. If there are global variables in this
314 // scope then create and insert DIEs for these variables.
315 DIE &DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
317 DIE *SPDie = SPCU.getOrCreateSubprogramDIE(SP);
319 attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
321 const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
322 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
323 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
325 // Add name to the name table, we do this here because we're guaranteed
326 // to have concrete versions of our DW_TAG_subprogram nodes.
327 addSubprogramNames(SP, *SPDie);
332 /// Check whether we should create a DIE for the given Scope, return true
333 /// if we don't create a DIE (the corresponding DIE is null).
334 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
335 if (Scope->isAbstractScope())
338 // We don't create a DIE if there is no Range.
339 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
343 if (Ranges.size() > 1)
346 // We don't create a DIE if we have a single Range and the end label
348 SmallVectorImpl<InsnRange>::const_iterator RI = Ranges.begin();
349 MCSymbol *End = getLabelAfterInsn(RI->second);
353 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
354 dwarf::Attribute A, const MCSymbol *L,
355 const MCSymbol *Sec) {
356 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
357 U.addSectionLabel(D, A, L);
359 U.addSectionDelta(D, A, L, Sec);
362 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
363 const SmallVectorImpl<InsnRange> &Range) {
364 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
365 // emitting it appropriately.
366 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
368 // Under fission, ranges are specified by constant offsets relative to the
369 // CU's DW_AT_GNU_ranges_base.
371 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
372 DwarfDebugRangeSectionSym);
374 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
375 DwarfDebugRangeSectionSym);
377 RangeSpanList List(RangeSym);
378 for (const InsnRange &R : Range) {
379 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
380 List.addRange(std::move(Span));
383 // Add the range list to the set of ranges to be emitted.
384 TheCU.addRangeList(std::move(List));
387 void DwarfDebug::attachRangesOrLowHighPC(DwarfCompileUnit &TheCU, DIE &Die,
388 const SmallVectorImpl<InsnRange> &Ranges) {
389 assert(!Ranges.empty());
390 if (Ranges.size() == 1)
391 attachLowHighPC(TheCU, Die, getLabelBeforeInsn(Ranges.front().first),
392 getLabelAfterInsn(Ranges.front().second));
394 addScopeRangeList(TheCU, Die, Ranges);
397 // Construct new DW_TAG_lexical_block for this scope and attach
398 // DW_AT_low_pc/DW_AT_high_pc labels.
400 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
401 LexicalScope *Scope) {
402 if (isLexicalScopeDIENull(Scope))
405 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
406 if (Scope->isAbstractScope())
409 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
414 // This scope represents inlined body of a function. Construct DIE to
415 // represent this concrete inlined copy of the function.
417 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
418 LexicalScope *Scope) {
419 assert(Scope->getScopeNode());
420 DIScope DS(Scope->getScopeNode());
421 DISubprogram InlinedSP = getDISubprogram(DS);
422 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
423 // was inlined from another compile unit.
424 DIE *OriginDIE = AbstractSPDies[InlinedSP];
425 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
427 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
428 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
430 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
432 InlinedSubprogramDIEs.insert(OriginDIE);
434 // Add the call site information to the DIE.
435 DILocation DL(Scope->getInlinedAt());
436 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
437 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
438 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
440 // Add name to the name table, we do this here because we're guaranteed
441 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
442 addSubprogramNames(InlinedSP, *ScopeDIE);
447 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
449 const LexicalScope &Scope,
450 DIE *&ObjectPointer) {
451 auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
452 if (DV.isObjectPointer())
453 ObjectPointer = Var.get();
457 DIE *DwarfDebug::createScopeChildrenDIE(
458 DwarfCompileUnit &TheCU, LexicalScope *Scope,
459 SmallVectorImpl<std::unique_ptr<DIE>> &Children) {
460 DIE *ObjectPointer = nullptr;
462 // Collect arguments for current function.
463 if (LScopes.isCurrentFunctionScope(Scope)) {
464 for (DbgVariable *ArgDV : CurrentFnArguments)
467 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
469 // If this is a variadic function, add an unspecified parameter.
470 DISubprogram SP(Scope->getScopeNode());
471 DITypeArray FnArgs = SP.getType().getTypeArray();
472 // If we have a single element of null, it is a function that returns void.
473 // If we have more than one elements and the last one is null, it is a
474 // variadic function.
475 if (FnArgs.getNumElements() > 1 &&
476 !FnArgs.getElement(FnArgs.getNumElements() - 1))
478 make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
481 // Collect lexical scope children first.
482 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
483 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
485 for (LexicalScope *LS : Scope->getChildren())
486 if (std::unique_ptr<DIE> Nested = constructScopeDIE(TheCU, LS))
487 Children.push_back(std::move(Nested));
488 return ObjectPointer;
491 void DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
492 LexicalScope *Scope, DIE &ScopeDIE) {
493 // We create children when the scope DIE is not null.
494 SmallVector<std::unique_ptr<DIE>, 8> Children;
495 if (DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children))
496 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
499 for (auto &I : Children)
500 ScopeDIE.addChild(std::move(I));
503 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
504 LexicalScope *Scope) {
505 assert(Scope && Scope->getScopeNode());
506 assert(Scope->isAbstractScope());
507 assert(!Scope->getInlinedAt());
509 DISubprogram SP(Scope->getScopeNode());
511 ProcessedSPNodes.insert(SP);
513 DIE *&AbsDef = AbstractSPDies[SP];
517 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
518 // was inlined from another compile unit.
519 DwarfCompileUnit &SPCU = *SPMap[SP];
522 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
523 // the important distinction that the DIDescriptor is not associated with the
524 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
525 // any). It could be refactored to some common utility function.
526 if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
527 ContextDIE = &SPCU.getUnitDie();
528 SPCU.getOrCreateSubprogramDIE(SPDecl);
530 ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
532 // Passing null as the associated DIDescriptor because the abstract definition
533 // shouldn't be found by lookup.
534 AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
536 SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
538 SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
539 createAndAddScopeChildren(SPCU, Scope, *AbsDef);
542 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
543 LexicalScope *Scope) {
544 assert(Scope && Scope->getScopeNode());
545 assert(!Scope->getInlinedAt());
546 assert(!Scope->isAbstractScope());
547 DISubprogram Sub(Scope->getScopeNode());
549 assert(Sub.isSubprogram());
551 ProcessedSPNodes.insert(Sub);
553 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
555 createAndAddScopeChildren(TheCU, Scope, ScopeDIE);
560 // Construct a DIE for this scope.
561 std::unique_ptr<DIE> DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
562 LexicalScope *Scope) {
563 if (!Scope || !Scope->getScopeNode())
566 DIScope DS(Scope->getScopeNode());
568 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
569 "Only handle inlined subprograms here, use "
570 "constructSubprogramScopeDIE for non-inlined "
573 SmallVector<std::unique_ptr<DIE>, 8> Children;
575 // We try to create the scope DIE first, then the children DIEs. This will
576 // avoid creating un-used children then removing them later when we find out
577 // the scope DIE is null.
578 std::unique_ptr<DIE> ScopeDIE;
579 if (Scope->getParent() && DS.isSubprogram()) {
580 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
583 // We create children when the scope DIE is not null.
584 createScopeChildrenDIE(TheCU, Scope, Children);
586 // Early exit when we know the scope DIE is going to be null.
587 if (isLexicalScopeDIENull(Scope))
590 // We create children here when we know the scope DIE is not going to be
591 // null and the children will be added to the scope DIE.
592 createScopeChildrenDIE(TheCU, Scope, Children);
594 // There is no need to emit empty lexical block DIE.
595 std::pair<ImportedEntityMap::const_iterator,
596 ImportedEntityMap::const_iterator> Range =
597 std::equal_range(ScopesWithImportedEntities.begin(),
598 ScopesWithImportedEntities.end(),
599 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
601 if (Children.empty() && Range.first == Range.second)
603 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
604 assert(ScopeDIE && "Scope DIE should not be null.");
605 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
607 constructImportedEntityDIE(TheCU, i->second, *ScopeDIE);
611 for (auto &I : Children)
612 ScopeDIE->addChild(std::move(I));
617 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
618 if (!GenerateGnuPubSections)
621 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
624 // Create new DwarfCompileUnit for the given metadata node with tag
625 // DW_TAG_compile_unit.
626 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
627 StringRef FN = DIUnit.getFilename();
628 CompilationDir = DIUnit.getDirectory();
630 auto OwnedUnit = make_unique<DwarfCompileUnit>(
631 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
632 DwarfCompileUnit &NewCU = *OwnedUnit;
633 DIE &Die = NewCU.getUnitDie();
634 InfoHolder.addUnit(std::move(OwnedUnit));
636 // LTO with assembly output shares a single line table amongst multiple CUs.
637 // To avoid the compilation directory being ambiguous, let the line table
638 // explicitly describe the directory of all files, never relying on the
639 // compilation directory.
640 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
641 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
642 NewCU.getUniqueID(), CompilationDir);
644 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
645 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
646 DIUnit.getLanguage());
647 NewCU.addString(Die, dwarf::DW_AT_name, FN);
649 if (!useSplitDwarf()) {
650 NewCU.initStmtList(DwarfLineSectionSym);
652 // If we're using split dwarf the compilation dir is going to be in the
653 // skeleton CU and so we don't need to duplicate it here.
654 if (!CompilationDir.empty())
655 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
657 addGnuPubAttributes(NewCU, Die);
660 if (DIUnit.isOptimized())
661 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
663 StringRef Flags = DIUnit.getFlags();
665 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
667 if (unsigned RVer = DIUnit.getRunTimeVersion())
668 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
669 dwarf::DW_FORM_data1, RVer);
674 if (useSplitDwarf()) {
675 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
676 DwarfInfoDWOSectionSym);
677 NewCU.setSkeleton(constructSkeletonCU(NewCU));
679 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
680 DwarfInfoSectionSym);
682 CUMap.insert(std::make_pair(DIUnit, &NewCU));
683 CUDieMap.insert(std::make_pair(&Die, &NewCU));
687 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
689 DIImportedEntity Module(N);
690 assert(Module.Verify());
691 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
692 constructImportedEntityDIE(TheCU, Module, *D);
695 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
696 const MDNode *N, DIE &Context) {
697 DIImportedEntity Module(N);
698 assert(Module.Verify());
699 return constructImportedEntityDIE(TheCU, Module, Context);
702 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
703 const DIImportedEntity &Module,
705 assert(Module.Verify() &&
706 "Use one of the MDNode * overloads to handle invalid metadata");
707 DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), Context, Module);
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);
718 TheCU.addSourceLine(IMDie, Module.getLineNumber(),
719 Module.getContext().getFilename(),
720 Module.getContext().getDirectory());
721 TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
722 StringRef Name = Module.getName();
724 TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
727 // Emit all Dwarf sections that should come prior to the content. Create
728 // global DIEs and emit initial debug info sections. This is invoked by
729 // the target AsmPrinter.
730 void DwarfDebug::beginModule() {
731 if (DisableDebugInfoPrinting)
734 const Module *M = MMI->getModule();
736 FunctionDIs = makeSubprogramMap(*M);
738 // If module has named metadata anchors then use them, otherwise scan the
739 // module using debug info finder to collect debug info.
740 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
743 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
745 // Emit initial sections so we can reference labels later.
748 SingleCU = CU_Nodes->getNumOperands() == 1;
750 for (MDNode *N : CU_Nodes->operands()) {
751 DICompileUnit CUNode(N);
752 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
753 DIArray ImportedEntities = CUNode.getImportedEntities();
754 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
755 ScopesWithImportedEntities.push_back(std::make_pair(
756 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
757 ImportedEntities.getElement(i)));
758 std::sort(ScopesWithImportedEntities.begin(),
759 ScopesWithImportedEntities.end(), less_first());
760 DIArray GVs = CUNode.getGlobalVariables();
761 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
762 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
763 DIArray SPs = CUNode.getSubprograms();
764 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
765 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
766 DIArray EnumTypes = CUNode.getEnumTypes();
767 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
768 DIType Ty(EnumTypes.getElement(i));
769 // The enum types array by design contains pointers to
770 // MDNodes rather than DIRefs. Unique them here.
771 DIType UniqueTy(resolve(Ty.getRef()));
772 CU.getOrCreateTypeDIE(UniqueTy);
774 DIArray RetainedTypes = CUNode.getRetainedTypes();
775 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
776 DIType Ty(RetainedTypes.getElement(i));
777 // The retained types array by design contains pointers to
778 // MDNodes rather than DIRefs. Unique them here.
779 DIType UniqueTy(resolve(Ty.getRef()));
780 CU.getOrCreateTypeDIE(UniqueTy);
782 // Emit imported_modules last so that the relevant context is already
784 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
785 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
788 // Tell MMI that we have debug info.
789 MMI->setDebugInfoAvailability(true);
791 // Prime section data.
792 SectionMap[Asm->getObjFileLowering().getTextSection()];
795 void DwarfDebug::finishVariableDefinitions() {
796 for (const auto &Var : ConcreteVariables) {
797 DIE *VariableDie = Var->getDIE();
798 // FIXME: There shouldn't be any variables without DIEs.
800 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
801 // in the ConcreteVariables list, rather than looking it up again here.
802 // DIE::getUnit isn't simple - it walks parent pointers, etc.
803 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
805 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
806 if (AbsVar && AbsVar->getDIE()) {
807 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
810 Unit->applyVariableAttributes(*Var, *VariableDie);
814 void DwarfDebug::finishSubprogramDefinitions() {
815 const Module *M = MMI->getModule();
817 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
818 for (MDNode *N : CU_Nodes->operands()) {
819 DICompileUnit TheCU(N);
820 // Construct subprogram DIE and add variables DIEs.
821 DwarfCompileUnit *SPCU =
822 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
823 DIArray Subprograms = TheCU.getSubprograms();
824 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
825 DISubprogram SP(Subprograms.getElement(i));
826 // Perhaps the subprogram is in another CU (such as due to comdat
827 // folding, etc), in which case ignore it here.
828 if (SPMap[SP] != SPCU)
830 DIE *D = SPCU->getDIE(SP);
831 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
833 // If this subprogram has an abstract definition, reference that
834 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
837 // Lazily construct the subprogram if we didn't see either concrete or
838 // inlined versions during codegen.
839 D = SPCU->getOrCreateSubprogramDIE(SP);
840 // And attach the attributes
841 SPCU->applySubprogramAttributesToDefinition(SP, *D);
848 // Collect info for variables that were optimized out.
849 void DwarfDebug::collectDeadVariables() {
850 const Module *M = MMI->getModule();
852 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
853 for (MDNode *N : CU_Nodes->operands()) {
854 DICompileUnit TheCU(N);
855 // Construct subprogram DIE and add variables DIEs.
856 DwarfCompileUnit *SPCU =
857 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
858 assert(SPCU && "Unable to find Compile Unit!");
859 DIArray Subprograms = TheCU.getSubprograms();
860 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
861 DISubprogram SP(Subprograms.getElement(i));
862 if (ProcessedSPNodes.count(SP) != 0)
864 assert(SP.isSubprogram() &&
865 "CU's subprogram list contains a non-subprogram");
866 assert(SP.isDefinition() &&
867 "CU's subprogram list contains a subprogram declaration");
868 DIArray Variables = SP.getVariables();
869 if (Variables.getNumElements() == 0)
872 DIE *SPDIE = AbstractSPDies.lookup(SP);
874 SPDIE = SPCU->getDIE(SP);
876 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
877 DIVariable DV(Variables.getElement(vi));
878 assert(DV.isVariable());
879 DbgVariable NewVar(DV, this);
880 auto VariableDie = SPCU->constructVariableDIE(NewVar);
881 SPCU->applyVariableAttributes(NewVar, *VariableDie);
882 SPDIE->addChild(std::move(VariableDie));
889 void DwarfDebug::finalizeModuleInfo() {
890 finishSubprogramDefinitions();
892 finishVariableDefinitions();
894 // Collect info for variables that were optimized out.
895 collectDeadVariables();
897 // Handle anything that needs to be done on a per-unit basis after
898 // all other generation.
899 for (const auto &TheU : getUnits()) {
900 // Emit DW_AT_containing_type attribute to connect types with their
901 // vtable holding type.
902 TheU->constructContainingTypeDIEs();
904 // Add CU specific attributes if we need to add any.
905 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
906 // If we're splitting the dwarf out now that we've got the entire
907 // CU then add the dwo id to it.
908 DwarfCompileUnit *SkCU =
909 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
910 if (useSplitDwarf()) {
911 // Emit a unique identifier for this CU.
912 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
913 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
914 dwarf::DW_FORM_data8, ID);
915 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
916 dwarf::DW_FORM_data8, ID);
918 // We don't keep track of which addresses are used in which CU so this
919 // is a bit pessimistic under LTO.
920 if (!AddrPool.isEmpty())
921 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
922 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
923 DwarfAddrSectionSym);
924 if (!TheU->getRangeLists().empty())
925 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
926 dwarf::DW_AT_GNU_ranges_base,
927 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
930 // If we have code split among multiple sections or non-contiguous
931 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
932 // remain in the .o file, otherwise add a DW_AT_low_pc.
933 // FIXME: We should use ranges allow reordering of code ala
934 // .subsections_via_symbols in mach-o. This would mean turning on
935 // ranges for all subprogram DIEs for mach-o.
936 DwarfCompileUnit &U =
937 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
938 unsigned NumRanges = TheU->getRanges().size();
941 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
942 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
943 DwarfDebugRangeSectionSym);
945 // A DW_AT_low_pc attribute may also be specified in combination with
946 // DW_AT_ranges to specify the default base address for use in
947 // location lists (see Section 2.6.2) and range lists (see Section
949 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
952 RangeSpan &Range = TheU->getRanges().back();
953 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
955 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
962 // Compute DIE offsets and sizes.
963 InfoHolder.computeSizeAndOffsets();
965 SkeletonHolder.computeSizeAndOffsets();
968 void DwarfDebug::endSections() {
969 // Filter labels by section.
970 for (const SymbolCU &SCU : ArangeLabels) {
971 if (SCU.Sym->isInSection()) {
972 // Make a note of this symbol and it's section.
973 const MCSection *Section = &SCU.Sym->getSection();
974 if (!Section->getKind().isMetadata())
975 SectionMap[Section].push_back(SCU);
977 // Some symbols (e.g. common/bss on mach-o) can have no section but still
978 // appear in the output. This sucks as we rely on sections to build
979 // arange spans. We can do it without, but it's icky.
980 SectionMap[nullptr].push_back(SCU);
984 // Build a list of sections used.
985 std::vector<const MCSection *> Sections;
986 for (const auto &it : SectionMap) {
987 const MCSection *Section = it.first;
988 Sections.push_back(Section);
991 // Sort the sections into order.
992 // This is only done to ensure consistent output order across different runs.
993 std::sort(Sections.begin(), Sections.end(), SectionSort);
995 // Add terminating symbols for each section.
996 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
997 const MCSection *Section = Sections[ID];
998 MCSymbol *Sym = nullptr;
1001 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1002 // if we know the section name up-front. For user-created sections, the
1003 // resulting label may not be valid to use as a label. (section names can
1004 // use a greater set of characters on some systems)
1005 Sym = Asm->GetTempSymbol("debug_end", ID);
1006 Asm->OutStreamer.SwitchSection(Section);
1007 Asm->OutStreamer.EmitLabel(Sym);
1010 // Insert a final terminator.
1011 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1015 // Emit all Dwarf sections that should come after the content.
1016 void DwarfDebug::endModule() {
1017 assert(CurFn == nullptr);
1018 assert(CurMI == nullptr);
1023 // End any existing sections.
1024 // TODO: Does this need to happen?
1027 // Finalize the debug info for the module.
1028 finalizeModuleInfo();
1032 // Emit all the DIEs into a debug info section.
1035 // Corresponding abbreviations into a abbrev section.
1036 emitAbbreviations();
1038 // Emit info into a debug aranges section.
1039 if (GenerateARangeSection)
1042 // Emit info into a debug ranges section.
1045 if (useSplitDwarf()) {
1048 emitDebugAbbrevDWO();
1051 // Emit DWO addresses.
1052 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1054 // Emit info into a debug loc section.
1057 // Emit info into the dwarf accelerator table sections.
1058 if (useDwarfAccelTables()) {
1061 emitAccelNamespaces();
1065 // Emit the pubnames and pubtypes sections if requested.
1066 if (HasDwarfPubSections) {
1067 emitDebugPubNames(GenerateGnuPubSections);
1068 emitDebugPubTypes(GenerateGnuPubSections);
1073 AbstractVariables.clear();
1075 // Reset these for the next Module if we have one.
1079 // Find abstract variable, if any, associated with Var.
1080 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1081 DIVariable &Cleansed) {
1082 LLVMContext &Ctx = DV->getContext();
1083 // More then one inlined variable corresponds to one abstract variable.
1084 // FIXME: This duplication of variables when inlining should probably be
1085 // removed. It's done to allow each DIVariable to describe its location
1086 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1087 // make it accurate then remove this duplication/cleansing stuff.
1088 Cleansed = cleanseInlinedVariable(DV, Ctx);
1089 auto I = AbstractVariables.find(Cleansed);
1090 if (I != AbstractVariables.end())
1091 return I->second.get();
1095 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1096 DIVariable Cleansed;
1097 return getExistingAbstractVariable(DV, Cleansed);
1100 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1101 LexicalScope *Scope) {
1102 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1103 addScopeVariable(Scope, AbsDbgVariable.get());
1104 AbstractVariables[Var] = std::move(AbsDbgVariable);
1107 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1108 const MDNode *ScopeNode) {
1109 DIVariable Cleansed = DV;
1110 if (getExistingAbstractVariable(DV, Cleansed))
1113 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1117 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1118 const MDNode *ScopeNode) {
1119 DIVariable Cleansed = DV;
1120 if (getExistingAbstractVariable(DV, Cleansed))
1123 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1124 createAbstractVariable(Cleansed, Scope);
1127 // If Var is a current function argument then add it to CurrentFnArguments list.
1128 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1129 if (!LScopes.isCurrentFunctionScope(Scope))
1131 DIVariable DV = Var->getVariable();
1132 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1134 unsigned ArgNo = DV.getArgNumber();
1138 size_t Size = CurrentFnArguments.size();
1140 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1141 // llvm::Function argument size is not good indicator of how many
1142 // arguments does the function have at source level.
1144 CurrentFnArguments.resize(ArgNo * 2);
1145 CurrentFnArguments[ArgNo - 1] = Var;
1149 // Collect variable information from side table maintained by MMI.
1150 void DwarfDebug::collectVariableInfoFromMMITable(
1151 SmallPtrSet<const MDNode *, 16> &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 buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1232 const DbgValueHistoryMap::InstrRanges &Ranges,
1233 DwarfCompileUnit *TheCU) {
1234 typedef std::pair<DIVariable, DebugLocEntry::Value> Range;
1235 SmallVector<Range, 4> OpenRanges;
1237 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1238 const MachineInstr *Begin = I->first;
1239 const MachineInstr *End = I->second;
1240 assert(Begin->isDebugValue() && "Invalid History entry");
1242 // Check if a variable is inaccessible in this range.
1243 if (!Begin->isDebugValue() ||
1244 (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1245 !Begin->getOperand(0).getReg())) {
1250 // If this piece overlaps with any open ranges, truncate them.
1251 DIVariable DIVar = Begin->getDebugVariable();
1252 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(), [&](Range R){
1253 return piecesOverlap(DIVar, R.first);
1255 OpenRanges.erase(Last, OpenRanges.end());
1257 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1258 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1260 const MCSymbol *EndLabel;
1262 EndLabel = getLabelAfterInsn(End);
1263 else if (std::next(I) == Ranges.end())
1264 EndLabel = FunctionEndSym;
1266 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1267 assert(EndLabel && "Forgot label after instruction ending a range!");
1269 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1271 auto Value = getDebugLocValue(Begin);
1272 DebugLocEntry Loc(StartLabel, EndLabel, Value, TheCU);
1273 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc)) {
1274 // Add all values from still valid non-overlapping pieces.
1275 for (auto Range : OpenRanges)
1276 Loc.addValue(Range.second);
1277 DebugLoc.push_back(std::move(Loc));
1279 // Add this value to the list of open ranges.
1280 if (DIVar.isVariablePiece())
1281 OpenRanges.push_back(std::make_pair(DIVar, Value));
1283 DEBUG(dbgs() << "Values:\n";
1284 for (auto Value : DebugLoc.back().getValues())
1285 Value.getVariable()->dump();
1286 dbgs() << "-----\n");
1291 // Find variables for each lexical scope.
1293 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1294 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1295 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1297 // Grab the variable info that was squirreled away in the MMI side-table.
1298 collectVariableInfoFromMMITable(Processed);
1300 for (const auto &I : DbgValues) {
1301 DIVariable DV(I.first);
1302 if (Processed.count(DV))
1305 // Instruction ranges, specifying where DV is accessible.
1306 const auto &Ranges = I.second;
1310 LexicalScope *Scope = nullptr;
1311 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1312 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1313 Scope = LScopes.getCurrentFunctionScope();
1314 else if (MDNode *IA = DV.getInlinedAt()) {
1315 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1316 Scope = LScopes.findInlinedScope(DebugLoc::get(
1317 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1319 Scope = LScopes.findLexicalScope(DV.getContext());
1320 // If variable scope is not found then skip this variable.
1324 Processed.insert(getEntireVariable(DV));
1325 const MachineInstr *MInsn = Ranges.front().first;
1326 assert(MInsn->isDebugValue() && "History must begin with debug value");
1327 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1328 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1329 DbgVariable *RegVar = ConcreteVariables.back().get();
1330 addScopeVariable(Scope, RegVar);
1332 // Check if the first DBG_VALUE is valid for the rest of the function.
1333 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1336 // Handle multiple DBG_VALUE instructions describing one variable.
1337 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1339 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1340 DebugLocList &LocList = DotDebugLocEntries.back();
1342 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1344 // Build the location list for this variable.
1345 buildLocationList(LocList.List, Ranges, TheCU);
1348 // Collect info for variables that were optimized out.
1349 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1350 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1351 DIVariable DV(Variables.getElement(i));
1352 assert(DV.isVariable());
1353 if (!Processed.insert(DV))
1355 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1356 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1357 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1358 addScopeVariable(Scope, ConcreteVariables.back().get());
1363 // Return Label preceding the instruction.
1364 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1365 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1366 assert(Label && "Didn't insert label before instruction");
1370 // Return Label immediately following the instruction.
1371 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1372 return LabelsAfterInsn.lookup(MI);
1375 // Process beginning of an instruction.
1376 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1377 assert(CurMI == nullptr);
1379 // Check if source location changes, but ignore DBG_VALUE locations.
1380 if (!MI->isDebugValue()) {
1381 DebugLoc DL = MI->getDebugLoc();
1382 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1385 if (DL == PrologEndLoc) {
1386 Flags |= DWARF2_FLAG_PROLOGUE_END;
1387 PrologEndLoc = DebugLoc();
1389 if (PrologEndLoc.isUnknown())
1390 Flags |= DWARF2_FLAG_IS_STMT;
1392 if (!DL.isUnknown()) {
1393 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1394 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1396 recordSourceLine(0, 0, nullptr, 0);
1400 // Insert labels where requested.
1401 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1402 LabelsBeforeInsn.find(MI);
1405 if (I == LabelsBeforeInsn.end())
1408 // Label already assigned.
1413 PrevLabel = MMI->getContext().CreateTempSymbol();
1414 Asm->OutStreamer.EmitLabel(PrevLabel);
1416 I->second = PrevLabel;
1419 // Process end of an instruction.
1420 void DwarfDebug::endInstruction() {
1421 assert(CurMI != nullptr);
1422 // Don't create a new label after DBG_VALUE instructions.
1423 // They don't generate code.
1424 if (!CurMI->isDebugValue())
1425 PrevLabel = nullptr;
1427 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1428 LabelsAfterInsn.find(CurMI);
1432 if (I == LabelsAfterInsn.end())
1435 // Label already assigned.
1439 // We need a label after this instruction.
1441 PrevLabel = MMI->getContext().CreateTempSymbol();
1442 Asm->OutStreamer.EmitLabel(PrevLabel);
1444 I->second = PrevLabel;
1447 // Each LexicalScope has first instruction and last instruction to mark
1448 // beginning and end of a scope respectively. Create an inverse map that list
1449 // scopes starts (and ends) with an instruction. One instruction may start (or
1450 // end) multiple scopes. Ignore scopes that are not reachable.
1451 void DwarfDebug::identifyScopeMarkers() {
1452 SmallVector<LexicalScope *, 4> WorkList;
1453 WorkList.push_back(LScopes.getCurrentFunctionScope());
1454 while (!WorkList.empty()) {
1455 LexicalScope *S = WorkList.pop_back_val();
1457 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1458 if (!Children.empty())
1459 WorkList.append(Children.begin(), Children.end());
1461 if (S->isAbstractScope())
1464 for (const InsnRange &R : S->getRanges()) {
1465 assert(R.first && "InsnRange does not have first instruction!");
1466 assert(R.second && "InsnRange does not have second instruction!");
1467 requestLabelBeforeInsn(R.first);
1468 requestLabelAfterInsn(R.second);
1473 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1474 // First known non-DBG_VALUE and non-frame setup location marks
1475 // the beginning of the function body.
1476 for (const auto &MBB : *MF)
1477 for (const auto &MI : MBB)
1478 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1479 !MI.getDebugLoc().isUnknown())
1480 return MI.getDebugLoc();
1484 // Gather pre-function debug information. Assumes being called immediately
1485 // after the function entry point has been emitted.
1486 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1489 // If there's no debug info for the function we're not going to do anything.
1490 if (!MMI->hasDebugInfo())
1493 auto DI = FunctionDIs.find(MF->getFunction());
1494 if (DI == FunctionDIs.end())
1497 // Grab the lexical scopes for the function, if we don't have any of those
1498 // then we're not going to be able to do anything.
1499 LScopes.initialize(*MF);
1500 if (LScopes.empty())
1503 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1505 // Make sure that each lexical scope will have a begin/end label.
1506 identifyScopeMarkers();
1508 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1509 // belongs to so that we add to the correct per-cu line table in the
1511 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1512 // FnScope->getScopeNode() and DI->second should represent the same function,
1513 // though they may not be the same MDNode due to inline functions merged in
1514 // LTO where the debug info metadata still differs (either due to distinct
1515 // written differences - two versions of a linkonce_odr function
1516 // written/copied into two separate files, or some sub-optimal metadata that
1517 // isn't structurally identical (see: file path/name info from clang, which
1518 // includes the directory of the cpp file being built, even when the file name
1519 // is absolute (such as an <> lookup header)))
1520 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1521 assert(TheCU && "Unable to find compile unit!");
1522 if (Asm->OutStreamer.hasRawTextSupport())
1523 // Use a single line table if we are generating assembly.
1524 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1526 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1528 // Emit a label for the function so that we have a beginning address.
1529 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1530 // Assumes in correct section after the entry point.
1531 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1533 // Calculate history for local variables.
1534 calculateDbgValueHistory(MF, Asm->TM.getRegisterInfo(), DbgValues);
1536 // Request labels for the full history.
1537 for (const auto &I : DbgValues) {
1538 const auto &Ranges = I.second;
1542 // The first mention of a function argument gets the FunctionBeginSym
1543 // label, so arguments are visible when breaking at function entry.
1544 DIVariable DV(Ranges.front().first->getDebugVariable());
1545 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1546 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1547 if (!DV.isVariablePiece())
1548 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1550 // Mark all non-overlapping initial pieces.
1551 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1552 DIVariable Piece = I->first->getDebugVariable();
1553 if (std::all_of(Ranges.begin(), I,
1554 [&](DbgValueHistoryMap::InstrRange Pred){
1555 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1557 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1564 for (const auto &Range : Ranges) {
1565 requestLabelBeforeInsn(Range.first);
1567 requestLabelAfterInsn(Range.second);
1571 PrevInstLoc = DebugLoc();
1572 PrevLabel = FunctionBeginSym;
1574 // Record beginning of function.
1575 PrologEndLoc = findPrologueEndLoc(MF);
1576 if (!PrologEndLoc.isUnknown()) {
1577 DebugLoc FnStartDL =
1578 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1580 FnStartDL.getLine(), FnStartDL.getCol(),
1581 FnStartDL.getScope(MF->getFunction()->getContext()),
1582 // We'd like to list the prologue as "not statements" but GDB behaves
1583 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1584 DWARF2_FLAG_IS_STMT);
1588 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1589 if (addCurrentFnArgument(Var, LS))
1591 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1592 DIVariable DV = Var->getVariable();
1593 // Variables with positive arg numbers are parameters.
1594 if (unsigned ArgNum = DV.getArgNumber()) {
1595 // Keep all parameters in order at the start of the variable list to ensure
1596 // function types are correct (no out-of-order parameters)
1598 // This could be improved by only doing it for optimized builds (unoptimized
1599 // builds have the right order to begin with), searching from the back (this
1600 // would catch the unoptimized case quickly), or doing a binary search
1601 // rather than linear search.
1602 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1603 while (I != Vars.end()) {
1604 unsigned CurNum = (*I)->getVariable().getArgNumber();
1605 // A local (non-parameter) variable has been found, insert immediately
1609 // A later indexed parameter has been found, insert immediately before it.
1610 if (CurNum > ArgNum)
1614 Vars.insert(I, Var);
1618 Vars.push_back(Var);
1621 // Gather and emit post-function debug information.
1622 void DwarfDebug::endFunction(const MachineFunction *MF) {
1623 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1624 // though the beginFunction may not be called at all.
1625 // We should handle both cases.
1629 assert(CurFn == MF);
1630 assert(CurFn != nullptr);
1632 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1633 !FunctionDIs.count(MF->getFunction())) {
1634 // If we don't have a lexical scope for this function then there will
1635 // be a hole in the range information. Keep note of this by setting the
1636 // previously used section to nullptr.
1637 PrevSection = nullptr;
1643 // Define end label for subprogram.
1644 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1645 // Assumes in correct section after the entry point.
1646 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1648 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1649 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1651 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1652 collectVariableInfo(ProcessedVars);
1654 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1655 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1657 // Construct abstract scopes.
1658 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1659 DISubprogram SP(AScope->getScopeNode());
1660 assert(SP.isSubprogram());
1661 // Collect info for variables that were optimized out.
1662 DIArray Variables = SP.getVariables();
1663 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1664 DIVariable DV(Variables.getElement(i));
1665 assert(DV && DV.isVariable());
1666 if (!ProcessedVars.insert(DV))
1668 ensureAbstractVariableIsCreated(DV, DV.getContext());
1670 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1673 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1674 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1675 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1677 // Add the range of this function to the list of ranges for the CU.
1678 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1679 TheCU.addRange(std::move(Span));
1680 PrevSection = Asm->getCurrentSection();
1684 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1685 // DbgVariables except those that are also in AbstractVariables (since they
1686 // can be used cross-function)
1687 ScopeVariables.clear();
1688 CurrentFnArguments.clear();
1690 LabelsBeforeInsn.clear();
1691 LabelsAfterInsn.clear();
1692 PrevLabel = nullptr;
1696 // Register a source line with debug info. Returns the unique label that was
1697 // emitted and which provides correspondence to the source line list.
1698 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1703 unsigned Discriminator = 0;
1704 if (DIScope Scope = DIScope(S)) {
1705 assert(Scope.isScope());
1706 Fn = Scope.getFilename();
1707 Dir = Scope.getDirectory();
1708 if (Scope.isLexicalBlock())
1709 Discriminator = DILexicalBlock(S).getDiscriminator();
1711 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1712 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1713 .getOrCreateSourceID(Fn, Dir);
1715 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1719 //===----------------------------------------------------------------------===//
1721 //===----------------------------------------------------------------------===//
1723 // Emit initial Dwarf sections with a label at the start of each one.
1724 void DwarfDebug::emitSectionLabels() {
1725 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1727 // Dwarf sections base addresses.
1728 DwarfInfoSectionSym =
1729 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1730 if (useSplitDwarf()) {
1731 DwarfInfoDWOSectionSym =
1732 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1733 DwarfTypesDWOSectionSym =
1734 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1736 DwarfAbbrevSectionSym =
1737 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1738 if (useSplitDwarf())
1739 DwarfAbbrevDWOSectionSym = emitSectionSym(
1740 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1741 if (GenerateARangeSection)
1742 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1744 DwarfLineSectionSym =
1745 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1746 if (GenerateGnuPubSections) {
1747 DwarfGnuPubNamesSectionSym =
1748 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1749 DwarfGnuPubTypesSectionSym =
1750 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1751 } else if (HasDwarfPubSections) {
1752 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1753 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1756 DwarfStrSectionSym =
1757 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1758 if (useSplitDwarf()) {
1759 DwarfStrDWOSectionSym =
1760 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1761 DwarfAddrSectionSym =
1762 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1763 DwarfDebugLocSectionSym =
1764 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1766 DwarfDebugLocSectionSym =
1767 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1768 DwarfDebugRangeSectionSym =
1769 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1772 // Recursively emits a debug information entry.
1773 void DwarfDebug::emitDIE(DIE &Die) {
1774 // Get the abbreviation for this DIE.
1775 const DIEAbbrev &Abbrev = Die.getAbbrev();
1777 // Emit the code (index) for the abbreviation.
1778 if (Asm->isVerbose())
1779 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1780 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1781 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1782 dwarf::TagString(Abbrev.getTag()));
1783 Asm->EmitULEB128(Abbrev.getNumber());
1785 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1786 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1788 // Emit the DIE attribute values.
1789 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1790 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1791 dwarf::Form Form = AbbrevData[i].getForm();
1792 assert(Form && "Too many attributes for DIE (check abbreviation)");
1794 if (Asm->isVerbose()) {
1795 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1796 if (Attr == dwarf::DW_AT_accessibility)
1797 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1798 cast<DIEInteger>(Values[i])->getValue()));
1801 // Emit an attribute using the defined form.
1802 Values[i]->EmitValue(Asm, Form);
1805 // Emit the DIE children if any.
1806 if (Abbrev.hasChildren()) {
1807 for (auto &Child : Die.getChildren())
1810 Asm->OutStreamer.AddComment("End Of Children Mark");
1815 // Emit the debug info section.
1816 void DwarfDebug::emitDebugInfo() {
1817 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1819 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1822 // Emit the abbreviation section.
1823 void DwarfDebug::emitAbbreviations() {
1824 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1826 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1829 // Emit the last address of the section and the end of the line matrix.
1830 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1831 // Define last address of section.
1832 Asm->OutStreamer.AddComment("Extended Op");
1835 Asm->OutStreamer.AddComment("Op size");
1836 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1837 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1838 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1840 Asm->OutStreamer.AddComment("Section end label");
1842 Asm->OutStreamer.EmitSymbolValue(
1843 Asm->GetTempSymbol("section_end", SectionEnd),
1844 Asm->getDataLayout().getPointerSize());
1846 // Mark end of matrix.
1847 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1853 // Emit visible names into a hashed accelerator table section.
1854 void DwarfDebug::emitAccelNames() {
1855 AccelNames.FinalizeTable(Asm, "Names");
1856 Asm->OutStreamer.SwitchSection(
1857 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1858 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1859 Asm->OutStreamer.EmitLabel(SectionBegin);
1861 // Emit the full data.
1862 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1865 // Emit objective C classes and categories into a hashed accelerator table
1867 void DwarfDebug::emitAccelObjC() {
1868 AccelObjC.FinalizeTable(Asm, "ObjC");
1869 Asm->OutStreamer.SwitchSection(
1870 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1871 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1872 Asm->OutStreamer.EmitLabel(SectionBegin);
1874 // Emit the full data.
1875 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1878 // Emit namespace dies into a hashed accelerator table.
1879 void DwarfDebug::emitAccelNamespaces() {
1880 AccelNamespace.FinalizeTable(Asm, "namespac");
1881 Asm->OutStreamer.SwitchSection(
1882 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1883 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1884 Asm->OutStreamer.EmitLabel(SectionBegin);
1886 // Emit the full data.
1887 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1890 // Emit type dies into a hashed accelerator table.
1891 void DwarfDebug::emitAccelTypes() {
1893 AccelTypes.FinalizeTable(Asm, "types");
1894 Asm->OutStreamer.SwitchSection(
1895 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1896 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1897 Asm->OutStreamer.EmitLabel(SectionBegin);
1899 // Emit the full data.
1900 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1903 // Public name handling.
1904 // The format for the various pubnames:
1906 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1907 // for the DIE that is named.
1909 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1910 // into the CU and the index value is computed according to the type of value
1911 // for the DIE that is named.
1913 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1914 // it's the offset within the debug_info/debug_types dwo section, however, the
1915 // reference in the pubname header doesn't change.
1917 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1918 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1920 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1922 // We could have a specification DIE that has our most of our knowledge,
1923 // look for that now.
1924 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1926 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1927 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1928 Linkage = dwarf::GIEL_EXTERNAL;
1929 } else if (Die->findAttribute(dwarf::DW_AT_external))
1930 Linkage = dwarf::GIEL_EXTERNAL;
1932 switch (Die->getTag()) {
1933 case dwarf::DW_TAG_class_type:
1934 case dwarf::DW_TAG_structure_type:
1935 case dwarf::DW_TAG_union_type:
1936 case dwarf::DW_TAG_enumeration_type:
1937 return dwarf::PubIndexEntryDescriptor(
1938 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1939 ? dwarf::GIEL_STATIC
1940 : dwarf::GIEL_EXTERNAL);
1941 case dwarf::DW_TAG_typedef:
1942 case dwarf::DW_TAG_base_type:
1943 case dwarf::DW_TAG_subrange_type:
1944 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1945 case dwarf::DW_TAG_namespace:
1946 return dwarf::GIEK_TYPE;
1947 case dwarf::DW_TAG_subprogram:
1948 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1949 case dwarf::DW_TAG_constant:
1950 case dwarf::DW_TAG_variable:
1951 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1952 case dwarf::DW_TAG_enumerator:
1953 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1954 dwarf::GIEL_STATIC);
1956 return dwarf::GIEK_NONE;
1960 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1962 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1963 const MCSection *PSec =
1964 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1965 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1967 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1970 void DwarfDebug::emitDebugPubSection(
1971 bool GnuStyle, const MCSection *PSec, StringRef Name,
1972 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1973 for (const auto &NU : CUMap) {
1974 DwarfCompileUnit *TheU = NU.second;
1976 const auto &Globals = (TheU->*Accessor)();
1978 if (Globals.empty())
1981 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1983 unsigned ID = TheU->getUniqueID();
1985 // Start the dwarf pubnames section.
1986 Asm->OutStreamer.SwitchSection(PSec);
1989 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1990 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
1991 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
1992 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1994 Asm->OutStreamer.EmitLabel(BeginLabel);
1996 Asm->OutStreamer.AddComment("DWARF Version");
1997 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1999 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2000 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2002 Asm->OutStreamer.AddComment("Compilation Unit Length");
2003 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2005 // Emit the pubnames for this compilation unit.
2006 for (const auto &GI : Globals) {
2007 const char *Name = GI.getKeyData();
2008 const DIE *Entity = GI.second;
2010 Asm->OutStreamer.AddComment("DIE offset");
2011 Asm->EmitInt32(Entity->getOffset());
2014 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2015 Asm->OutStreamer.AddComment(
2016 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2017 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2018 Asm->EmitInt8(Desc.toBits());
2021 Asm->OutStreamer.AddComment("External Name");
2022 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2025 Asm->OutStreamer.AddComment("End Mark");
2027 Asm->OutStreamer.EmitLabel(EndLabel);
2031 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2032 const MCSection *PSec =
2033 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2034 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2036 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2039 // Emit visible names into a debug str section.
2040 void DwarfDebug::emitDebugStr() {
2041 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2042 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2045 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2046 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2047 const DITypeIdentifierMap &Map,
2048 ArrayRef<DebugLocEntry::Value> Values) {
2049 typedef DebugLocEntry::Value Piece;
2050 SmallVector<Piece, 4> Pieces(Values.begin(), Values.end());
2051 assert(std::all_of(Pieces.begin(), Pieces.end(), [](Piece &P) {
2052 return DIVariable(P.getVariable()).isVariablePiece();
2053 }) && "all values are expected to be pieces");
2055 // Sort the pieces so they can be emitted using DW_OP_piece.
2056 std::sort(Pieces.begin(), Pieces.end(), [](const Piece &A, const Piece &B) {
2057 DIVariable VarA(A.getVariable());
2058 DIVariable VarB(B.getVariable());
2059 return VarA.getPieceOffset() < VarB.getPieceOffset();
2061 // Remove any duplicate entries by dropping all but the first.
2062 Pieces.erase(std::unique(Pieces.begin(), Pieces.end(),
2063 [] (const Piece &A,const Piece &B){
2064 return A.getVariable() == B.getVariable();
2067 unsigned Offset = 0;
2068 for (auto Piece : Pieces) {
2069 DIVariable Var(Piece.getVariable());
2070 unsigned PieceOffset = Var.getPieceOffset();
2071 unsigned PieceSize = Var.getPieceSize();
2072 assert(Offset <= PieceOffset && "overlapping pieces in DebugLocEntry");
2073 if (Offset < PieceOffset) {
2074 // The DWARF spec seriously mandates pieces with no locations for gaps.
2075 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2076 Offset += PieceOffset-Offset;
2079 Offset += PieceSize;
2081 const unsigned SizeOfByte = 8;
2082 assert(!Var.isIndirect() && "indirect address for piece");
2084 unsigned VarSize = Var.getSizeInBits(Map);
2085 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2086 && "piece is larger than or outside of variable");
2087 assert(PieceSize*SizeOfByte != VarSize
2088 && "piece covers entire variable");
2090 if (Piece.isLocation() && Piece.getLoc().isReg())
2091 Asm->EmitDwarfRegOpPiece(Streamer,
2093 PieceSize*SizeOfByte);
2095 emitDebugLocValue(Streamer, Piece);
2096 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2102 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2103 const DebugLocEntry &Entry) {
2104 const DebugLocEntry::Value Value = Entry.getValues()[0];
2105 DIVariable DV(Value.getVariable());
2106 if (DV.isVariablePiece())
2107 // Emit all pieces that belong to the same variable and range.
2108 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2110 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2111 emitDebugLocValue(Streamer, Value);
2114 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2115 const DebugLocEntry::Value &Value) {
2116 DIVariable DV(Value.getVariable());
2118 if (Value.isInt()) {
2119 DIBasicType BTy(resolve(DV.getType()));
2120 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2121 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2122 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2123 Streamer.EmitSLEB128(Value.getInt());
2125 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2126 Streamer.EmitULEB128(Value.getInt());
2128 } else if (Value.isLocation()) {
2129 MachineLocation Loc = Value.getLoc();
2130 if (!DV.hasComplexAddress())
2132 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2134 // Complex address entry.
2135 unsigned N = DV.getNumAddrElements();
2137 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2138 if (Loc.getOffset()) {
2140 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2141 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2142 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2143 Streamer.EmitSLEB128(DV.getAddrElement(1));
2145 // If first address element is OpPlus then emit
2146 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2147 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2148 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2152 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2155 // Emit remaining complex address elements.
2156 for (; i < N; ++i) {
2157 uint64_t Element = DV.getAddrElement(i);
2158 if (Element == DIBuilder::OpPlus) {
2159 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2160 Streamer.EmitULEB128(DV.getAddrElement(++i));
2161 } else if (Element == DIBuilder::OpDeref) {
2163 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2164 } else if (Element == DIBuilder::OpPiece) {
2166 // handled in emitDebugLocEntry.
2168 llvm_unreachable("unknown Opcode found in complex address");
2172 // else ... ignore constant fp. There is not any good way to
2173 // to represent them here in dwarf.
2177 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2178 Asm->OutStreamer.AddComment("Loc expr size");
2179 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2180 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2181 Asm->EmitLabelDifference(end, begin, 2);
2182 Asm->OutStreamer.EmitLabel(begin);
2184 APByteStreamer Streamer(*Asm);
2185 emitDebugLocEntry(Streamer, Entry);
2187 Asm->OutStreamer.EmitLabel(end);
2190 // Emit locations into the debug loc section.
2191 void DwarfDebug::emitDebugLoc() {
2192 // Start the dwarf loc section.
2193 Asm->OutStreamer.SwitchSection(
2194 Asm->getObjFileLowering().getDwarfLocSection());
2195 unsigned char Size = Asm->getDataLayout().getPointerSize();
2196 for (const auto &DebugLoc : DotDebugLocEntries) {
2197 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2198 for (const auto &Entry : DebugLoc.List) {
2199 // Set up the range. This range is relative to the entry point of the
2200 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2201 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2202 const DwarfCompileUnit *CU = Entry.getCU();
2203 if (CU->getRanges().size() == 1) {
2204 // Grab the begin symbol from the first range as our base.
2205 const MCSymbol *Base = CU->getRanges()[0].getStart();
2206 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2207 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2209 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2210 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2213 emitDebugLocEntryLocation(Entry);
2215 Asm->OutStreamer.EmitIntValue(0, Size);
2216 Asm->OutStreamer.EmitIntValue(0, Size);
2220 void DwarfDebug::emitDebugLocDWO() {
2221 Asm->OutStreamer.SwitchSection(
2222 Asm->getObjFileLowering().getDwarfLocDWOSection());
2223 for (const auto &DebugLoc : DotDebugLocEntries) {
2224 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2225 for (const auto &Entry : DebugLoc.List) {
2226 // Just always use start_length for now - at least that's one address
2227 // rather than two. We could get fancier and try to, say, reuse an
2228 // address we know we've emitted elsewhere (the start of the function?
2229 // The start of the CU or CU subrange that encloses this range?)
2230 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2231 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2232 Asm->EmitULEB128(idx);
2233 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2235 emitDebugLocEntryLocation(Entry);
2237 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2242 const MCSymbol *Start, *End;
2245 // Emit a debug aranges section, containing a CU lookup for any
2246 // address we can tie back to a CU.
2247 void DwarfDebug::emitDebugARanges() {
2248 // Start the dwarf aranges section.
2249 Asm->OutStreamer.SwitchSection(
2250 Asm->getObjFileLowering().getDwarfARangesSection());
2252 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2256 // Build a list of sections used.
2257 std::vector<const MCSection *> Sections;
2258 for (const auto &it : SectionMap) {
2259 const MCSection *Section = it.first;
2260 Sections.push_back(Section);
2263 // Sort the sections into order.
2264 // This is only done to ensure consistent output order across different runs.
2265 std::sort(Sections.begin(), Sections.end(), SectionSort);
2267 // Build a set of address spans, sorted by CU.
2268 for (const MCSection *Section : Sections) {
2269 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2270 if (List.size() < 2)
2273 // Sort the symbols by offset within the section.
2274 std::sort(List.begin(), List.end(),
2275 [&](const SymbolCU &A, const SymbolCU &B) {
2276 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2277 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2279 // Symbols with no order assigned should be placed at the end.
2280 // (e.g. section end labels)
2288 // If we have no section (e.g. common), just write out
2289 // individual spans for each symbol.
2291 for (const SymbolCU &Cur : List) {
2293 Span.Start = Cur.Sym;
2296 Spans[Cur.CU].push_back(Span);
2299 // Build spans between each label.
2300 const MCSymbol *StartSym = List[0].Sym;
2301 for (size_t n = 1, e = List.size(); n < e; n++) {
2302 const SymbolCU &Prev = List[n - 1];
2303 const SymbolCU &Cur = List[n];
2305 // Try and build the longest span we can within the same CU.
2306 if (Cur.CU != Prev.CU) {
2308 Span.Start = StartSym;
2310 Spans[Prev.CU].push_back(Span);
2317 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2319 // Build a list of CUs used.
2320 std::vector<DwarfCompileUnit *> CUs;
2321 for (const auto &it : Spans) {
2322 DwarfCompileUnit *CU = it.first;
2326 // Sort the CU list (again, to ensure consistent output order).
2327 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2328 return A->getUniqueID() < B->getUniqueID();
2331 // Emit an arange table for each CU we used.
2332 for (DwarfCompileUnit *CU : CUs) {
2333 std::vector<ArangeSpan> &List = Spans[CU];
2335 // Emit size of content not including length itself.
2336 unsigned ContentSize =
2337 sizeof(int16_t) + // DWARF ARange version number
2338 sizeof(int32_t) + // Offset of CU in the .debug_info section
2339 sizeof(int8_t) + // Pointer Size (in bytes)
2340 sizeof(int8_t); // Segment Size (in bytes)
2342 unsigned TupleSize = PtrSize * 2;
2344 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2346 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2348 ContentSize += Padding;
2349 ContentSize += (List.size() + 1) * TupleSize;
2351 // For each compile unit, write the list of spans it covers.
2352 Asm->OutStreamer.AddComment("Length of ARange Set");
2353 Asm->EmitInt32(ContentSize);
2354 Asm->OutStreamer.AddComment("DWARF Arange version number");
2355 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2356 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2357 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2358 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2359 Asm->EmitInt8(PtrSize);
2360 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2363 Asm->OutStreamer.EmitFill(Padding, 0xff);
2365 for (const ArangeSpan &Span : List) {
2366 Asm->EmitLabelReference(Span.Start, PtrSize);
2368 // Calculate the size as being from the span start to it's end.
2370 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2372 // For symbols without an end marker (e.g. common), we
2373 // write a single arange entry containing just that one symbol.
2374 uint64_t Size = SymSize[Span.Start];
2378 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2382 Asm->OutStreamer.AddComment("ARange terminator");
2383 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2384 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2388 // Emit visible names into a debug ranges section.
2389 void DwarfDebug::emitDebugRanges() {
2390 // Start the dwarf ranges section.
2391 Asm->OutStreamer.SwitchSection(
2392 Asm->getObjFileLowering().getDwarfRangesSection());
2394 // Size for our labels.
2395 unsigned char Size = Asm->getDataLayout().getPointerSize();
2397 // Grab the specific ranges for the compile units in the module.
2398 for (const auto &I : CUMap) {
2399 DwarfCompileUnit *TheCU = I.second;
2401 // Iterate over the misc ranges for the compile units in the module.
2402 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2403 // Emit our symbol so we can find the beginning of the range.
2404 Asm->OutStreamer.EmitLabel(List.getSym());
2406 for (const RangeSpan &Range : List.getRanges()) {
2407 const MCSymbol *Begin = Range.getStart();
2408 const MCSymbol *End = Range.getEnd();
2409 assert(Begin && "Range without a begin symbol?");
2410 assert(End && "Range without an end symbol?");
2411 if (TheCU->getRanges().size() == 1) {
2412 // Grab the begin symbol from the first range as our base.
2413 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2414 Asm->EmitLabelDifference(Begin, Base, Size);
2415 Asm->EmitLabelDifference(End, Base, Size);
2417 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2418 Asm->OutStreamer.EmitSymbolValue(End, Size);
2422 // And terminate the list with two 0 values.
2423 Asm->OutStreamer.EmitIntValue(0, Size);
2424 Asm->OutStreamer.EmitIntValue(0, Size);
2427 // Now emit a range for the CU itself.
2428 if (TheCU->getRanges().size() > 1) {
2429 Asm->OutStreamer.EmitLabel(
2430 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2431 for (const RangeSpan &Range : TheCU->getRanges()) {
2432 const MCSymbol *Begin = Range.getStart();
2433 const MCSymbol *End = Range.getEnd();
2434 assert(Begin && "Range without a begin symbol?");
2435 assert(End && "Range without an end symbol?");
2436 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2437 Asm->OutStreamer.EmitSymbolValue(End, Size);
2439 // And terminate the list with two 0 values.
2440 Asm->OutStreamer.EmitIntValue(0, Size);
2441 Asm->OutStreamer.EmitIntValue(0, Size);
2446 // DWARF5 Experimental Separate Dwarf emitters.
2448 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2449 std::unique_ptr<DwarfUnit> NewU) {
2450 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2451 U.getCUNode().getSplitDebugFilename());
2453 if (!CompilationDir.empty())
2454 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2456 addGnuPubAttributes(*NewU, Die);
2458 SkeletonHolder.addUnit(std::move(NewU));
2461 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2462 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2463 // DW_AT_addr_base, DW_AT_ranges_base.
2464 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2466 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2467 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2468 DwarfCompileUnit &NewCU = *OwnedUnit;
2469 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2470 DwarfInfoSectionSym);
2472 NewCU.initStmtList(DwarfLineSectionSym);
2474 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2479 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2481 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2482 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2483 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2485 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2487 DwarfTypeUnit &NewTU = *OwnedUnit;
2488 NewTU.setTypeSignature(TU.getTypeSignature());
2489 NewTU.setType(nullptr);
2491 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2493 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2497 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2498 // compile units that would normally be in debug_info.
2499 void DwarfDebug::emitDebugInfoDWO() {
2500 assert(useSplitDwarf() && "No split dwarf debug info?");
2501 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2502 // emit relocations into the dwo file.
2503 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2506 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2507 // abbreviations for the .debug_info.dwo section.
2508 void DwarfDebug::emitDebugAbbrevDWO() {
2509 assert(useSplitDwarf() && "No split dwarf?");
2510 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2513 void DwarfDebug::emitDebugLineDWO() {
2514 assert(useSplitDwarf() && "No split dwarf?");
2515 Asm->OutStreamer.SwitchSection(
2516 Asm->getObjFileLowering().getDwarfLineDWOSection());
2517 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2520 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2521 // string section and is identical in format to traditional .debug_str
2523 void DwarfDebug::emitDebugStrDWO() {
2524 assert(useSplitDwarf() && "No split dwarf?");
2525 const MCSection *OffSec =
2526 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2527 const MCSymbol *StrSym = DwarfStrSectionSym;
2528 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2532 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2533 if (!useSplitDwarf())
2536 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2537 return &SplitTypeUnitFileTable;
2540 static uint64_t makeTypeSignature(StringRef Identifier) {
2542 Hash.update(Identifier);
2543 // ... take the least significant 8 bytes and return those. Our MD5
2544 // implementation always returns its results in little endian, swap bytes
2546 MD5::MD5Result Result;
2548 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2551 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2552 StringRef Identifier, DIE &RefDie,
2553 DICompositeType CTy) {
2554 // Fast path if we're building some type units and one has already used the
2555 // address pool we know we're going to throw away all this work anyway, so
2556 // don't bother building dependent types.
2557 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2560 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2562 CU.addDIETypeSignature(RefDie, *TU);
2566 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2567 AddrPool.resetUsedFlag();
2569 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2570 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2571 this, &InfoHolder, getDwoLineTable(CU));
2572 DwarfTypeUnit &NewTU = *OwnedUnit;
2573 DIE &UnitDie = NewTU.getUnitDie();
2575 TypeUnitsUnderConstruction.push_back(
2576 std::make_pair(std::move(OwnedUnit), CTy));
2578 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2581 uint64_t Signature = makeTypeSignature(Identifier);
2582 NewTU.setTypeSignature(Signature);
2584 if (useSplitDwarf())
2585 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2586 DwarfTypesDWOSectionSym);
2588 CU.applyStmtList(UnitDie);
2590 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2593 NewTU.setType(NewTU.createTypeDIE(CTy));
2596 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2597 TypeUnitsUnderConstruction.clear();
2599 // Types referencing entries in the address table cannot be placed in type
2601 if (AddrPool.hasBeenUsed()) {
2603 // Remove all the types built while building this type.
2604 // This is pessimistic as some of these types might not be dependent on
2605 // the type that used an address.
2606 for (const auto &TU : TypeUnitsToAdd)
2607 DwarfTypeUnits.erase(TU.second);
2609 // Construct this type in the CU directly.
2610 // This is inefficient because all the dependent types will be rebuilt
2611 // from scratch, including building them in type units, discovering that
2612 // they depend on addresses, throwing them out and rebuilding them.
2613 CU.constructTypeDIE(RefDie, CTy);
2617 // If the type wasn't dependent on fission addresses, finish adding the type
2618 // and all its dependent types.
2619 for (auto &TU : TypeUnitsToAdd) {
2620 if (useSplitDwarf())
2621 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2622 InfoHolder.addUnit(std::move(TU.first));
2625 CU.addDIETypeSignature(RefDie, NewTU);
2628 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2629 MCSymbol *Begin, MCSymbol *End) {
2630 assert(Begin && "Begin label should not be null!");
2631 assert(End && "End label should not be null!");
2632 assert(Begin->isDefined() && "Invalid starting label");
2633 assert(End->isDefined() && "Invalid end label");
2635 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2636 if (DwarfVersion < 4)
2637 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2639 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2642 // Accelerator table mutators - add each name along with its companion
2643 // DIE to the proper table while ensuring that the name that we're going
2644 // to reference is in the string table. We do this since the names we
2645 // add may not only be identical to the names in the DIE.
2646 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2647 if (!useDwarfAccelTables())
2649 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2653 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2654 if (!useDwarfAccelTables())
2656 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2660 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2661 if (!useDwarfAccelTables())
2663 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2667 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2668 if (!useDwarfAccelTables())
2670 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),