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 "DwarfDebug.h"
15 #include "ByteStreamer.h"
17 #include "DebugLocEntry.h"
18 #include "DwarfCompileUnit.h"
19 #include "DwarfExpression.h"
20 #include "DwarfUnit.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/CodeGen/DIE.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineModuleInfo.h"
28 #include "llvm/IR/Constants.h"
29 #include "llvm/IR/DIBuilder.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/DebugInfo.h"
32 #include "llvm/IR/Instructions.h"
33 #include "llvm/IR/Module.h"
34 #include "llvm/IR/ValueHandle.h"
35 #include "llvm/MC/MCAsmInfo.h"
36 #include "llvm/MC/MCSection.h"
37 #include "llvm/MC/MCStreamer.h"
38 #include "llvm/MC/MCSymbol.h"
39 #include "llvm/Support/CommandLine.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Support/Dwarf.h"
42 #include "llvm/Support/Endian.h"
43 #include "llvm/Support/ErrorHandling.h"
44 #include "llvm/Support/FormattedStream.h"
45 #include "llvm/Support/LEB128.h"
46 #include "llvm/Support/MD5.h"
47 #include "llvm/Support/Path.h"
48 #include "llvm/Support/Timer.h"
49 #include "llvm/Support/raw_ostream.h"
50 #include "llvm/Target/TargetFrameLowering.h"
51 #include "llvm/Target/TargetLoweringObjectFile.h"
52 #include "llvm/Target/TargetMachine.h"
53 #include "llvm/Target/TargetOptions.h"
54 #include "llvm/Target/TargetRegisterInfo.h"
55 #include "llvm/Target/TargetSubtargetInfo.h"
58 #define DEBUG_TYPE "dwarfdebug"
61 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
62 cl::desc("Disable debug info printing"));
64 static cl::opt<bool> UnknownLocations(
65 "use-unknown-locations", cl::Hidden,
66 cl::desc("Make an absence of debug location information explicit."),
70 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
71 cl::desc("Generate GNU-style pubnames and pubtypes"),
74 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
76 cl::desc("Generate dwarf aranges"),
80 enum DefaultOnOff { Default, Enable, Disable };
83 static cl::opt<DefaultOnOff>
84 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
85 cl::desc("Output prototype dwarf accelerator tables."),
86 cl::values(clEnumVal(Default, "Default for platform"),
87 clEnumVal(Enable, "Enabled"),
88 clEnumVal(Disable, "Disabled"), clEnumValEnd),
91 static cl::opt<DefaultOnOff>
92 SplitDwarf("split-dwarf", cl::Hidden,
93 cl::desc("Output DWARF5 split debug info."),
94 cl::values(clEnumVal(Default, "Default for platform"),
95 clEnumVal(Enable, "Enabled"),
96 clEnumVal(Disable, "Disabled"), clEnumValEnd),
99 static cl::opt<DefaultOnOff>
100 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
101 cl::desc("Generate DWARF pubnames and pubtypes sections"),
102 cl::values(clEnumVal(Default, "Default for platform"),
103 clEnumVal(Enable, "Enabled"),
104 clEnumVal(Disable, "Disabled"), clEnumValEnd),
107 static const char *const DWARFGroupName = "DWARF Emission";
108 static const char *const DbgTimerName = "DWARF Debug Writer";
110 void DebugLocDwarfExpression::EmitOp(uint8_t Op, const char *Comment) {
112 Op, Comment ? Twine(Comment) + " " + dwarf::OperationEncodingString(Op)
113 : dwarf::OperationEncodingString(Op));
116 void DebugLocDwarfExpression::EmitSigned(int64_t Value) {
117 BS.EmitSLEB128(Value, Twine(Value));
120 void DebugLocDwarfExpression::EmitUnsigned(uint64_t Value) {
121 BS.EmitULEB128(Value, Twine(Value));
124 bool DebugLocDwarfExpression::isFrameRegister(unsigned MachineReg) {
125 // This information is not available while emitting .debug_loc entries.
129 //===----------------------------------------------------------------------===//
131 /// resolve - Look in the DwarfDebug map for the MDNode that
132 /// corresponds to the reference.
133 template <typename T> T *DbgVariable::resolve(TypedDINodeRef<T> Ref) const {
134 return DD->resolve(Ref);
137 bool DbgVariable::isBlockByrefVariable() const {
138 assert(Var && "Invalid complex DbgVariable!");
139 return Var->getType()
140 .resolve(DD->getTypeIdentifierMap())
141 ->isBlockByrefStruct();
144 const DIType *DbgVariable::getType() const {
145 DIType *Ty = Var->getType().resolve(DD->getTypeIdentifierMap());
146 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
147 // addresses instead.
148 if (Ty->isBlockByrefStruct()) {
149 /* Byref variables, in Blocks, are declared by the programmer as
150 "SomeType VarName;", but the compiler creates a
151 __Block_byref_x_VarName struct, and gives the variable VarName
152 either the struct, or a pointer to the struct, as its type. This
153 is necessary for various behind-the-scenes things the compiler
154 needs to do with by-reference variables in blocks.
156 However, as far as the original *programmer* is concerned, the
157 variable should still have type 'SomeType', as originally declared.
159 The following function dives into the __Block_byref_x_VarName
160 struct to find the original type of the variable. This will be
161 passed back to the code generating the type for the Debug
162 Information Entry for the variable 'VarName'. 'VarName' will then
163 have the original type 'SomeType' in its debug information.
165 The original type 'SomeType' will be the type of the field named
166 'VarName' inside the __Block_byref_x_VarName struct.
168 NOTE: In order for this to not completely fail on the debugger
169 side, the Debug Information Entry for the variable VarName needs to
170 have a DW_AT_location that tells the debugger how to unwind through
171 the pointers and __Block_byref_x_VarName struct to find the actual
172 value of the variable. The function addBlockByrefType does this. */
173 DIType *subType = Ty;
174 uint16_t tag = Ty->getTag();
176 if (tag == dwarf::DW_TAG_pointer_type)
177 subType = resolve(cast<DIDerivedType>(Ty)->getBaseType());
179 auto Elements = cast<DICompositeTypeBase>(subType)->getElements();
180 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
181 auto *DT = cast<DIDerivedTypeBase>(Elements[i]);
182 if (getName() == DT->getName())
183 return resolve(DT->getBaseType());
189 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
190 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
191 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
192 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
194 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
195 : Asm(A), MMI(Asm->MMI), DebugLocs(A->OutStreamer->isVerboseAsm()),
196 PrevLabel(nullptr), InfoHolder(A, "info_string", DIEValueAllocator),
197 UsedNonDefaultText(false),
198 SkeletonHolder(A, "skel_string", DIEValueAllocator),
199 IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
200 IsPS4(Triple(A->getTargetTriple()).isPS4()),
201 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
202 dwarf::DW_FORM_data4)),
203 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
204 dwarf::DW_FORM_data4)),
205 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
206 dwarf::DW_FORM_data4)),
207 AccelTypes(TypeAtoms) {
212 // Turn on accelerator tables for Darwin by default, pubnames by
213 // default for non-Darwin/PS4, and handle split dwarf.
214 if (DwarfAccelTables == Default)
215 HasDwarfAccelTables = IsDarwin;
217 HasDwarfAccelTables = DwarfAccelTables == Enable;
219 if (SplitDwarf == Default)
220 HasSplitDwarf = false;
222 HasSplitDwarf = SplitDwarf == Enable;
224 if (DwarfPubSections == Default)
225 HasDwarfPubSections = !IsDarwin && !IsPS4;
227 HasDwarfPubSections = DwarfPubSections == Enable;
229 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
230 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
231 : MMI->getModule()->getDwarfVersion();
233 // Darwin and PS4 use the standard TLS opcode (defined in DWARF 3).
234 // Everybody else uses GNU's.
235 UseGNUTLSOpcode = !(IsDarwin || IsPS4) || DwarfVersion < 3;
237 Asm->OutStreamer->getContext().setDwarfVersion(DwarfVersion);
240 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
245 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
246 DwarfDebug::~DwarfDebug() { }
248 static bool isObjCClass(StringRef Name) {
249 return Name.startswith("+") || Name.startswith("-");
252 static bool hasObjCCategory(StringRef Name) {
253 if (!isObjCClass(Name))
256 return Name.find(") ") != StringRef::npos;
259 static void getObjCClassCategory(StringRef In, StringRef &Class,
260 StringRef &Category) {
261 if (!hasObjCCategory(In)) {
262 Class = In.slice(In.find('[') + 1, In.find(' '));
267 Class = In.slice(In.find('[') + 1, In.find('('));
268 Category = In.slice(In.find('[') + 1, In.find(' '));
272 static StringRef getObjCMethodName(StringRef In) {
273 return In.slice(In.find(' ') + 1, In.find(']'));
276 // Add the various names to the Dwarf accelerator table names.
277 // TODO: Determine whether or not we should add names for programs
278 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
279 // is only slightly different than the lookup of non-standard ObjC names.
280 void DwarfDebug::addSubprogramNames(const DISubprogram *SP, DIE &Die) {
281 if (!SP->isDefinition())
283 addAccelName(SP->getName(), Die);
285 // If the linkage name is different than the name, go ahead and output
286 // that as well into the name table.
287 if (SP->getLinkageName() != "" && SP->getName() != SP->getLinkageName())
288 addAccelName(SP->getLinkageName(), Die);
290 // If this is an Objective-C selector name add it to the ObjC accelerator
292 if (isObjCClass(SP->getName())) {
293 StringRef Class, Category;
294 getObjCClassCategory(SP->getName(), Class, Category);
295 addAccelObjC(Class, Die);
297 addAccelObjC(Category, Die);
298 // Also add the base method name to the name table.
299 addAccelName(getObjCMethodName(SP->getName()), Die);
303 /// isSubprogramContext - Return true if Context is either a subprogram
304 /// or another context nested inside a subprogram.
305 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
308 if (isa<DISubprogram>(Context))
310 if (auto *T = dyn_cast<DIType>(Context))
311 return isSubprogramContext(resolve(T->getScope()));
315 /// Check whether we should create a DIE for the given Scope, return true
316 /// if we don't create a DIE (the corresponding DIE is null).
317 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
318 if (Scope->isAbstractScope())
321 // We don't create a DIE if there is no Range.
322 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
326 if (Ranges.size() > 1)
329 // We don't create a DIE if we have a single Range and the end label
331 return !getLabelAfterInsn(Ranges.front().second);
334 template <typename Func> void forBothCUs(DwarfCompileUnit &CU, Func F) {
336 if (auto *SkelCU = CU.getSkeleton())
340 void DwarfDebug::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
341 assert(Scope && Scope->getScopeNode());
342 assert(Scope->isAbstractScope());
343 assert(!Scope->getInlinedAt());
345 const MDNode *SP = Scope->getScopeNode();
347 ProcessedSPNodes.insert(SP);
349 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
350 // was inlined from another compile unit.
351 auto &CU = SPMap[SP];
352 forBothCUs(*CU, [&](DwarfCompileUnit &CU) {
353 CU.constructAbstractSubprogramScopeDIE(Scope);
357 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
358 if (!GenerateGnuPubSections)
361 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
364 // Create new DwarfCompileUnit for the given metadata node with tag
365 // DW_TAG_compile_unit.
367 DwarfDebug::constructDwarfCompileUnit(const DICompileUnit *DIUnit) {
368 StringRef FN = DIUnit->getFilename();
369 CompilationDir = DIUnit->getDirectory();
371 auto OwnedUnit = make_unique<DwarfCompileUnit>(
372 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
373 DwarfCompileUnit &NewCU = *OwnedUnit;
374 DIE &Die = NewCU.getUnitDie();
375 InfoHolder.addUnit(std::move(OwnedUnit));
377 NewCU.setSkeleton(constructSkeletonCU(NewCU));
379 // LTO with assembly output shares a single line table amongst multiple CUs.
380 // To avoid the compilation directory being ambiguous, let the line table
381 // explicitly describe the directory of all files, never relying on the
382 // compilation directory.
383 if (!Asm->OutStreamer->hasRawTextSupport() || SingleCU)
384 Asm->OutStreamer->getContext().setMCLineTableCompilationDir(
385 NewCU.getUniqueID(), CompilationDir);
387 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit->getProducer());
388 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
389 DIUnit->getSourceLanguage());
390 NewCU.addString(Die, dwarf::DW_AT_name, FN);
392 if (!useSplitDwarf()) {
393 NewCU.initStmtList();
395 // If we're using split dwarf the compilation dir is going to be in the
396 // skeleton CU and so we don't need to duplicate it here.
397 if (!CompilationDir.empty())
398 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
400 addGnuPubAttributes(NewCU, Die);
403 if (DIUnit->isOptimized())
404 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
406 StringRef Flags = DIUnit->getFlags();
408 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
410 if (unsigned RVer = DIUnit->getRuntimeVersion())
411 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
412 dwarf::DW_FORM_data1, RVer);
415 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection());
417 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
419 CUMap.insert(std::make_pair(DIUnit, &NewCU));
420 CUDieMap.insert(std::make_pair(&Die, &NewCU));
424 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
425 const DIImportedEntity *N) {
426 if (DIE *D = TheCU.getOrCreateContextDIE(N->getScope()))
427 D->addChild(TheCU.constructImportedEntityDIE(N));
430 // Emit all Dwarf sections that should come prior to the content. Create
431 // global DIEs and emit initial debug info sections. This is invoked by
432 // the target AsmPrinter.
433 void DwarfDebug::beginModule() {
434 if (DisableDebugInfoPrinting)
437 const Module *M = MMI->getModule();
439 FunctionDIs = makeSubprogramMap(*M);
441 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
444 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
446 SingleCU = CU_Nodes->getNumOperands() == 1;
448 for (MDNode *N : CU_Nodes->operands()) {
449 auto *CUNode = cast<DICompileUnit>(N);
450 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
451 for (auto *IE : CUNode->getImportedEntities())
452 ScopesWithImportedEntities.push_back(std::make_pair(IE->getScope(), IE));
453 // Stable sort to preserve the order of appearance of imported entities.
454 // This is to avoid out-of-order processing of interdependent declarations
455 // within the same scope, e.g. { namespace A = base; namespace B = A; }
456 std::stable_sort(ScopesWithImportedEntities.begin(),
457 ScopesWithImportedEntities.end(), less_first());
458 for (auto *GV : CUNode->getGlobalVariables())
459 CU.getOrCreateGlobalVariableDIE(GV);
460 for (auto *SP : CUNode->getSubprograms())
461 SPMap.insert(std::make_pair(SP, &CU));
462 for (auto *Ty : CUNode->getEnumTypes()) {
463 // The enum types array by design contains pointers to
464 // MDNodes rather than DIRefs. Unique them here.
465 CU.getOrCreateTypeDIE(cast<DIType>(resolve(Ty->getRef())));
467 for (auto *Ty : CUNode->getRetainedTypes()) {
468 // The retained types array by design contains pointers to
469 // MDNodes rather than DIRefs. Unique them here.
470 CU.getOrCreateTypeDIE(cast<DIType>(resolve(Ty->getRef())));
472 // Emit imported_modules last so that the relevant context is already
474 for (auto *IE : CUNode->getImportedEntities())
475 constructAndAddImportedEntityDIE(CU, IE);
478 // Tell MMI that we have debug info.
479 MMI->setDebugInfoAvailability(true);
482 void DwarfDebug::finishVariableDefinitions() {
483 for (const auto &Var : ConcreteVariables) {
484 DIE *VariableDie = Var->getDIE();
486 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
487 // in the ConcreteVariables list, rather than looking it up again here.
488 // DIE::getUnit isn't simple - it walks parent pointers, etc.
489 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
491 DbgVariable *AbsVar = getExistingAbstractVariable(
492 InlinedVariable(Var->getVariable(), Var->getInlinedAt()));
493 if (AbsVar && AbsVar->getDIE()) {
494 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
497 Unit->applyVariableAttributes(*Var, *VariableDie);
501 void DwarfDebug::finishSubprogramDefinitions() {
502 for (const auto &P : SPMap)
503 forBothCUs(*P.second, [&](DwarfCompileUnit &CU) {
504 CU.finishSubprogramDefinition(cast<DISubprogram>(P.first));
509 // Collect info for variables that were optimized out.
510 void DwarfDebug::collectDeadVariables() {
511 const Module *M = MMI->getModule();
513 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
514 for (MDNode *N : CU_Nodes->operands()) {
515 auto *TheCU = cast<DICompileUnit>(N);
516 // Construct subprogram DIE and add variables DIEs.
517 DwarfCompileUnit *SPCU =
518 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
519 assert(SPCU && "Unable to find Compile Unit!");
520 for (auto *SP : TheCU->getSubprograms()) {
521 if (ProcessedSPNodes.count(SP) != 0)
523 SPCU->collectDeadVariables(SP);
529 void DwarfDebug::finalizeModuleInfo() {
530 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
532 finishSubprogramDefinitions();
534 finishVariableDefinitions();
536 // Collect info for variables that were optimized out.
537 collectDeadVariables();
539 // Handle anything that needs to be done on a per-unit basis after
540 // all other generation.
541 for (const auto &P : CUMap) {
542 auto &TheCU = *P.second;
543 // Emit DW_AT_containing_type attribute to connect types with their
544 // vtable holding type.
545 TheCU.constructContainingTypeDIEs();
547 // Add CU specific attributes if we need to add any.
548 // If we're splitting the dwarf out now that we've got the entire
549 // CU then add the dwo id to it.
550 auto *SkCU = TheCU.getSkeleton();
551 if (useSplitDwarf()) {
552 // Emit a unique identifier for this CU.
553 uint64_t ID = DIEHash(Asm).computeCUSignature(TheCU.getUnitDie());
554 TheCU.addUInt(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
555 dwarf::DW_FORM_data8, ID);
556 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
557 dwarf::DW_FORM_data8, ID);
559 // We don't keep track of which addresses are used in which CU so this
560 // is a bit pessimistic under LTO.
561 if (!AddrPool.isEmpty()) {
562 const MCSymbol *Sym = TLOF.getDwarfAddrSection()->getBeginSymbol();
563 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_addr_base,
566 if (!SkCU->getRangeLists().empty()) {
567 const MCSymbol *Sym = TLOF.getDwarfRangesSection()->getBeginSymbol();
568 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
573 // If we have code split among multiple sections or non-contiguous
574 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
575 // remain in the .o file, otherwise add a DW_AT_low_pc.
576 // FIXME: We should use ranges allow reordering of code ala
577 // .subsections_via_symbols in mach-o. This would mean turning on
578 // ranges for all subprogram DIEs for mach-o.
579 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
580 if (unsigned NumRanges = TheCU.getRanges().size()) {
582 // A DW_AT_low_pc attribute may also be specified in combination with
583 // DW_AT_ranges to specify the default base address for use in
584 // location lists (see Section 2.6.2) and range lists (see Section
586 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
588 U.setBaseAddress(TheCU.getRanges().front().getStart());
589 U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
593 // Compute DIE offsets and sizes.
594 InfoHolder.computeSizeAndOffsets();
596 SkeletonHolder.computeSizeAndOffsets();
599 // Emit all Dwarf sections that should come after the content.
600 void DwarfDebug::endModule() {
601 assert(CurFn == nullptr);
602 assert(CurMI == nullptr);
604 // If we aren't actually generating debug info (check beginModule -
605 // conditionalized on !DisableDebugInfoPrinting and the presence of the
606 // llvm.dbg.cu metadata node)
607 if (!MMI->hasDebugInfo())
610 // Finalize the debug info for the module.
611 finalizeModuleInfo();
618 // Emit info into a debug loc section.
621 // Corresponding abbreviations into a abbrev section.
624 // Emit all the DIEs into a debug info section.
627 // Emit info into a debug aranges section.
628 if (GenerateARangeSection)
631 // Emit info into a debug ranges section.
634 if (useSplitDwarf()) {
637 emitDebugAbbrevDWO();
639 // Emit DWO addresses.
640 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
643 // Emit info into the dwarf accelerator table sections.
644 if (useDwarfAccelTables()) {
647 emitAccelNamespaces();
651 // Emit the pubnames and pubtypes sections if requested.
652 if (HasDwarfPubSections) {
653 emitDebugPubNames(GenerateGnuPubSections);
654 emitDebugPubTypes(GenerateGnuPubSections);
659 AbstractVariables.clear();
662 // Find abstract variable, if any, associated with Var.
664 DwarfDebug::getExistingAbstractVariable(InlinedVariable IV,
665 const DILocalVariable *&Cleansed) {
666 // More then one inlined variable corresponds to one abstract variable.
668 auto I = AbstractVariables.find(Cleansed);
669 if (I != AbstractVariables.end())
670 return I->second.get();
674 DbgVariable *DwarfDebug::getExistingAbstractVariable(InlinedVariable IV) {
675 const DILocalVariable *Cleansed;
676 return getExistingAbstractVariable(IV, Cleansed);
679 void DwarfDebug::createAbstractVariable(const DILocalVariable *Var,
680 LexicalScope *Scope) {
681 auto AbsDbgVariable = make_unique<DbgVariable>(Var, /* IA */ nullptr, this);
682 InfoHolder.addScopeVariable(Scope, AbsDbgVariable.get());
683 AbstractVariables[Var] = std::move(AbsDbgVariable);
686 void DwarfDebug::ensureAbstractVariableIsCreated(InlinedVariable IV,
687 const MDNode *ScopeNode) {
688 const DILocalVariable *Cleansed = nullptr;
689 if (getExistingAbstractVariable(IV, Cleansed))
692 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(
693 cast<DILocalScope>(ScopeNode)));
696 void DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(
697 InlinedVariable IV, const MDNode *ScopeNode) {
698 const DILocalVariable *Cleansed = nullptr;
699 if (getExistingAbstractVariable(IV, Cleansed))
702 if (LexicalScope *Scope =
703 LScopes.findAbstractScope(cast_or_null<DILocalScope>(ScopeNode)))
704 createAbstractVariable(Cleansed, Scope);
707 // Collect variable information from side table maintained by MMI.
708 void DwarfDebug::collectVariableInfoFromMMITable(
709 DenseSet<InlinedVariable> &Processed) {
710 for (const auto &VI : MMI->getVariableDbgInfo()) {
713 assert(VI.Var->isValidLocationForIntrinsic(VI.Loc) &&
714 "Expected inlined-at fields to agree");
716 InlinedVariable Var(VI.Var, VI.Loc->getInlinedAt());
717 Processed.insert(Var);
718 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
720 // If variable scope is not found then skip this variable.
724 ensureAbstractVariableIsCreatedIfScoped(Var, Scope->getScopeNode());
725 auto RegVar = make_unique<DbgVariable>(Var.first, Var.second, this);
726 RegVar->initializeMMI(VI.Expr, VI.Slot);
727 if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
728 ConcreteVariables.push_back(std::move(RegVar));
732 // Get .debug_loc entry for the instruction range starting at MI.
733 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
734 const DIExpression *Expr = MI->getDebugExpression();
736 assert(MI->getNumOperands() == 4);
737 if (MI->getOperand(0).isReg()) {
738 MachineLocation MLoc;
739 // If the second operand is an immediate, this is a
740 // register-indirect address.
741 if (!MI->getOperand(1).isImm())
742 MLoc.set(MI->getOperand(0).getReg());
744 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
745 return DebugLocEntry::Value(Expr, MLoc);
747 if (MI->getOperand(0).isImm())
748 return DebugLocEntry::Value(Expr, MI->getOperand(0).getImm());
749 if (MI->getOperand(0).isFPImm())
750 return DebugLocEntry::Value(Expr, MI->getOperand(0).getFPImm());
751 if (MI->getOperand(0).isCImm())
752 return DebugLocEntry::Value(Expr, MI->getOperand(0).getCImm());
754 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
757 /// Determine whether two variable pieces overlap.
758 static bool piecesOverlap(const DIExpression *P1, const DIExpression *P2) {
759 if (!P1->isBitPiece() || !P2->isBitPiece())
761 unsigned l1 = P1->getBitPieceOffset();
762 unsigned l2 = P2->getBitPieceOffset();
763 unsigned r1 = l1 + P1->getBitPieceSize();
764 unsigned r2 = l2 + P2->getBitPieceSize();
765 // True where [l1,r1[ and [r1,r2[ overlap.
766 return (l1 < r2) && (l2 < r1);
769 /// Build the location list for all DBG_VALUEs in the function that
770 /// describe the same variable. If the ranges of several independent
771 /// pieces of the same variable overlap partially, split them up and
772 /// combine the ranges. The resulting DebugLocEntries are will have
773 /// strict monotonically increasing begin addresses and will never
778 // Ranges History [var, loc, piece ofs size]
779 // 0 | [x, (reg0, piece 0, 32)]
780 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
782 // 3 | [clobber reg0]
783 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of
788 // [0-1] [x, (reg0, piece 0, 32)]
789 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
790 // [3-4] [x, (reg1, piece 32, 32)]
791 // [4- ] [x, (mem, piece 0, 64)]
793 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
794 const DbgValueHistoryMap::InstrRanges &Ranges) {
795 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
797 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
798 const MachineInstr *Begin = I->first;
799 const MachineInstr *End = I->second;
800 assert(Begin->isDebugValue() && "Invalid History entry");
802 // Check if a variable is inaccessible in this range.
803 if (Begin->getNumOperands() > 1 &&
804 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
809 // If this piece overlaps with any open ranges, truncate them.
810 const DIExpression *DIExpr = Begin->getDebugExpression();
811 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
812 [&](DebugLocEntry::Value R) {
813 return piecesOverlap(DIExpr, R.getExpression());
815 OpenRanges.erase(Last, OpenRanges.end());
817 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
818 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
820 const MCSymbol *EndLabel;
822 EndLabel = getLabelAfterInsn(End);
823 else if (std::next(I) == Ranges.end())
824 EndLabel = Asm->getFunctionEnd();
826 EndLabel = getLabelBeforeInsn(std::next(I)->first);
827 assert(EndLabel && "Forgot label after instruction ending a range!");
829 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
831 auto Value = getDebugLocValue(Begin);
832 DebugLocEntry Loc(StartLabel, EndLabel, Value);
833 bool couldMerge = false;
835 // If this is a piece, it may belong to the current DebugLocEntry.
836 if (DIExpr->isBitPiece()) {
837 // Add this value to the list of open ranges.
838 OpenRanges.push_back(Value);
840 // Attempt to add the piece to the last entry.
841 if (!DebugLoc.empty())
842 if (DebugLoc.back().MergeValues(Loc))
847 // Need to add a new DebugLocEntry. Add all values from still
848 // valid non-overlapping pieces.
849 if (OpenRanges.size())
850 Loc.addValues(OpenRanges);
852 DebugLoc.push_back(std::move(Loc));
855 // Attempt to coalesce the ranges of two otherwise identical
857 auto CurEntry = DebugLoc.rbegin();
859 dbgs() << CurEntry->getValues().size() << " Values:\n";
860 for (auto &Value : CurEntry->getValues())
861 Value.getExpression()->dump();
865 auto PrevEntry = std::next(CurEntry);
866 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
871 DbgVariable *DwarfDebug::createConcreteVariable(LexicalScope &Scope,
872 InlinedVariable IV) {
873 ensureAbstractVariableIsCreatedIfScoped(IV, Scope.getScopeNode());
874 ConcreteVariables.push_back(
875 make_unique<DbgVariable>(IV.first, IV.second, this));
876 InfoHolder.addScopeVariable(&Scope, ConcreteVariables.back().get());
877 return ConcreteVariables.back().get();
880 // Find variables for each lexical scope.
881 void DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU,
882 const DISubprogram *SP,
883 DenseSet<InlinedVariable> &Processed) {
884 // Grab the variable info that was squirreled away in the MMI side-table.
885 collectVariableInfoFromMMITable(Processed);
887 for (const auto &I : DbgValues) {
888 InlinedVariable IV = I.first;
889 if (Processed.count(IV))
892 // Instruction ranges, specifying where IV is accessible.
893 const auto &Ranges = I.second;
897 LexicalScope *Scope = nullptr;
898 if (const DILocation *IA = IV.second)
899 Scope = LScopes.findInlinedScope(IV.first->getScope(), IA);
901 Scope = LScopes.findLexicalScope(IV.first->getScope());
902 // If variable scope is not found then skip this variable.
906 Processed.insert(IV);
907 DbgVariable *RegVar = createConcreteVariable(*Scope, IV);
909 const MachineInstr *MInsn = Ranges.front().first;
910 assert(MInsn->isDebugValue() && "History must begin with debug value");
912 // Check if the first DBG_VALUE is valid for the rest of the function.
913 if (Ranges.size() == 1 && Ranges.front().second == nullptr) {
914 RegVar->initializeDbgValue(MInsn);
918 // Handle multiple DBG_VALUE instructions describing one variable.
919 DebugLocStream::ListBuilder List(DebugLocs, TheCU, *Asm, *RegVar, *MInsn);
921 // Build the location list for this variable.
922 SmallVector<DebugLocEntry, 8> Entries;
923 buildLocationList(Entries, Ranges);
925 // If the variable has an DIBasicType, extract it. Basic types cannot have
926 // unique identifiers, so don't bother resolving the type with the
928 const DIBasicType *BT = dyn_cast<DIBasicType>(
929 static_cast<const Metadata *>(IV.first->getType()));
931 // Finalize the entry by lowering it into a DWARF bytestream.
932 for (auto &Entry : Entries)
933 Entry.finalize(*Asm, List, BT);
936 // Collect info for variables that were optimized out.
937 for (const DILocalVariable *DV : SP->getVariables()) {
938 if (Processed.insert(InlinedVariable(DV, nullptr)).second)
939 if (LexicalScope *Scope = LScopes.findLexicalScope(DV->getScope()))
940 createConcreteVariable(*Scope, InlinedVariable(DV, nullptr));
944 // Return Label preceding the instruction.
945 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
946 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
947 assert(Label && "Didn't insert label before instruction");
951 // Return Label immediately following the instruction.
952 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
953 return LabelsAfterInsn.lookup(MI);
956 // Process beginning of an instruction.
957 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
958 assert(CurMI == nullptr);
960 // Check if source location changes, but ignore DBG_VALUE locations.
961 if (!MI->isDebugValue()) {
962 DebugLoc DL = MI->getDebugLoc();
963 if (DL != PrevInstLoc) {
967 if (DL == PrologEndLoc) {
968 Flags |= DWARF2_FLAG_PROLOGUE_END;
969 PrologEndLoc = DebugLoc();
970 Flags |= DWARF2_FLAG_IS_STMT;
973 Asm->OutStreamer->getContext().getCurrentDwarfLoc().getLine())
974 Flags |= DWARF2_FLAG_IS_STMT;
976 const MDNode *Scope = DL.getScope();
977 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
978 } else if (UnknownLocations) {
980 recordSourceLine(0, 0, nullptr, 0);
985 // Insert labels where requested.
986 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
987 LabelsBeforeInsn.find(MI);
990 if (I == LabelsBeforeInsn.end())
993 // Label already assigned.
998 PrevLabel = MMI->getContext().createTempSymbol();
999 Asm->OutStreamer->EmitLabel(PrevLabel);
1001 I->second = PrevLabel;
1004 // Process end of an instruction.
1005 void DwarfDebug::endInstruction() {
1006 assert(CurMI != nullptr);
1007 // Don't create a new label after DBG_VALUE instructions.
1008 // They don't generate code.
1009 if (!CurMI->isDebugValue())
1010 PrevLabel = nullptr;
1012 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1013 LabelsAfterInsn.find(CurMI);
1017 if (I == LabelsAfterInsn.end())
1020 // Label already assigned.
1024 // We need a label after this instruction.
1026 PrevLabel = MMI->getContext().createTempSymbol();
1027 Asm->OutStreamer->EmitLabel(PrevLabel);
1029 I->second = PrevLabel;
1032 // Each LexicalScope has first instruction and last instruction to mark
1033 // beginning and end of a scope respectively. Create an inverse map that list
1034 // scopes starts (and ends) with an instruction. One instruction may start (or
1035 // end) multiple scopes. Ignore scopes that are not reachable.
1036 void DwarfDebug::identifyScopeMarkers() {
1037 SmallVector<LexicalScope *, 4> WorkList;
1038 WorkList.push_back(LScopes.getCurrentFunctionScope());
1039 while (!WorkList.empty()) {
1040 LexicalScope *S = WorkList.pop_back_val();
1042 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1043 if (!Children.empty())
1044 WorkList.append(Children.begin(), Children.end());
1046 if (S->isAbstractScope())
1049 for (const InsnRange &R : S->getRanges()) {
1050 assert(R.first && "InsnRange does not have first instruction!");
1051 assert(R.second && "InsnRange does not have second instruction!");
1052 requestLabelBeforeInsn(R.first);
1053 requestLabelAfterInsn(R.second);
1058 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1059 // First known non-DBG_VALUE and non-frame setup location marks
1060 // the beginning of the function body.
1061 for (const auto &MBB : *MF)
1062 for (const auto &MI : MBB)
1063 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1065 // Did the target forget to set the FrameSetup flag for CFI insns?
1066 assert(!MI.isCFIInstruction() &&
1067 "First non-frame-setup instruction is a CFI instruction.");
1068 return MI.getDebugLoc();
1073 // Gather pre-function debug information. Assumes being called immediately
1074 // after the function entry point has been emitted.
1075 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1078 // If there's no debug info for the function we're not going to do anything.
1079 if (!MMI->hasDebugInfo())
1082 auto DI = FunctionDIs.find(MF->getFunction());
1083 if (DI == FunctionDIs.end())
1086 // Grab the lexical scopes for the function, if we don't have any of those
1087 // then we're not going to be able to do anything.
1088 LScopes.initialize(*MF);
1089 if (LScopes.empty())
1092 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1094 // Make sure that each lexical scope will have a begin/end label.
1095 identifyScopeMarkers();
1097 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1098 // belongs to so that we add to the correct per-cu line table in the
1100 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1101 // FnScope->getScopeNode() and DI->second should represent the same function,
1102 // though they may not be the same MDNode due to inline functions merged in
1103 // LTO where the debug info metadata still differs (either due to distinct
1104 // written differences - two versions of a linkonce_odr function
1105 // written/copied into two separate files, or some sub-optimal metadata that
1106 // isn't structurally identical (see: file path/name info from clang, which
1107 // includes the directory of the cpp file being built, even when the file name
1108 // is absolute (such as an <> lookup header)))
1109 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1110 assert(TheCU && "Unable to find compile unit!");
1111 if (Asm->OutStreamer->hasRawTextSupport())
1112 // Use a single line table if we are generating assembly.
1113 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
1115 Asm->OutStreamer->getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1117 // Calculate history for local variables.
1118 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1121 // Request labels for the full history.
1122 for (const auto &I : DbgValues) {
1123 const auto &Ranges = I.second;
1127 // The first mention of a function argument gets the CurrentFnBegin
1128 // label, so arguments are visible when breaking at function entry.
1129 const DILocalVariable *DIVar = Ranges.front().first->getDebugVariable();
1130 if (DIVar->getTag() == dwarf::DW_TAG_arg_variable &&
1131 getDISubprogram(DIVar->getScope())->describes(MF->getFunction())) {
1132 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1133 if (Ranges.front().first->getDebugExpression()->isBitPiece()) {
1134 // Mark all non-overlapping initial pieces.
1135 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1136 const DIExpression *Piece = I->first->getDebugExpression();
1137 if (std::all_of(Ranges.begin(), I,
1138 [&](DbgValueHistoryMap::InstrRange Pred) {
1139 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1141 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1148 for (const auto &Range : Ranges) {
1149 requestLabelBeforeInsn(Range.first);
1151 requestLabelAfterInsn(Range.second);
1155 PrevInstLoc = DebugLoc();
1156 PrevLabel = Asm->getFunctionBegin();
1158 // Record beginning of function.
1159 PrologEndLoc = findPrologueEndLoc(MF);
1160 if (DILocation *L = PrologEndLoc) {
1161 // We'd like to list the prologue as "not statements" but GDB behaves
1162 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1163 auto *SP = L->getInlinedAtScope()->getSubprogram();
1164 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1168 // Gather and emit post-function debug information.
1169 void DwarfDebug::endFunction(const MachineFunction *MF) {
1170 assert(CurFn == MF &&
1171 "endFunction should be called with the same function as beginFunction");
1173 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1174 !FunctionDIs.count(MF->getFunction())) {
1175 // If we don't have a lexical scope for this function then there will
1176 // be a hole in the range information. Keep note of this by setting the
1177 // previously used section to nullptr.
1183 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1184 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
1186 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1187 auto *SP = cast<DISubprogram>(FnScope->getScopeNode());
1188 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1190 DenseSet<InlinedVariable> ProcessedVars;
1191 collectVariableInfo(TheCU, SP, ProcessedVars);
1193 // Add the range of this function to the list of ranges for the CU.
1194 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1196 // Under -gmlt, skip building the subprogram if there are no inlined
1197 // subroutines inside it.
1198 if (TheCU.getCUNode()->getEmissionKind() == DIBuilder::LineTablesOnly &&
1199 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1200 assert(InfoHolder.getScopeVariables().empty());
1201 assert(DbgValues.empty());
1202 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1203 // by a -gmlt CU. Add a test and remove this assertion.
1204 assert(AbstractVariables.empty());
1205 LabelsBeforeInsn.clear();
1206 LabelsAfterInsn.clear();
1207 PrevLabel = nullptr;
1213 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1215 // Construct abstract scopes.
1216 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1217 auto *SP = cast<DISubprogram>(AScope->getScopeNode());
1218 // Collect info for variables that were optimized out.
1219 for (const DILocalVariable *DV : SP->getVariables()) {
1220 if (!ProcessedVars.insert(InlinedVariable(DV, nullptr)).second)
1222 ensureAbstractVariableIsCreated(InlinedVariable(DV, nullptr),
1224 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1225 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1227 constructAbstractSubprogramScopeDIE(AScope);
1230 TheCU.constructSubprogramScopeDIE(FnScope);
1231 if (auto *SkelCU = TheCU.getSkeleton())
1232 if (!LScopes.getAbstractScopesList().empty())
1233 SkelCU->constructSubprogramScopeDIE(FnScope);
1236 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1237 // DbgVariables except those that are also in AbstractVariables (since they
1238 // can be used cross-function)
1239 InfoHolder.getScopeVariables().clear();
1241 LabelsBeforeInsn.clear();
1242 LabelsAfterInsn.clear();
1243 PrevLabel = nullptr;
1247 // Register a source line with debug info. Returns the unique label that was
1248 // emitted and which provides correspondence to the source line list.
1249 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1254 unsigned Discriminator = 0;
1255 if (auto *Scope = cast_or_null<DIScope>(S)) {
1256 Fn = Scope->getFilename();
1257 Dir = Scope->getDirectory();
1258 if (auto *LBF = dyn_cast<DILexicalBlockFile>(Scope))
1259 Discriminator = LBF->getDiscriminator();
1261 unsigned CUID = Asm->OutStreamer->getContext().getDwarfCompileUnitID();
1262 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1263 .getOrCreateSourceID(Fn, Dir);
1265 Asm->OutStreamer->EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1269 //===----------------------------------------------------------------------===//
1271 //===----------------------------------------------------------------------===//
1273 // Emit the debug info section.
1274 void DwarfDebug::emitDebugInfo() {
1275 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1276 Holder.emitUnits(/* UseOffsets */ false);
1279 // Emit the abbreviation section.
1280 void DwarfDebug::emitAbbreviations() {
1281 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1283 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1286 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, MCSection *Section,
1287 StringRef TableName) {
1288 Accel.FinalizeTable(Asm, TableName);
1289 Asm->OutStreamer->SwitchSection(Section);
1291 // Emit the full data.
1292 Accel.emit(Asm, Section->getBeginSymbol(), this);
1295 // Emit visible names into a hashed accelerator table section.
1296 void DwarfDebug::emitAccelNames() {
1297 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1301 // Emit objective C classes and categories into a hashed accelerator table
1303 void DwarfDebug::emitAccelObjC() {
1304 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1308 // Emit namespace dies into a hashed accelerator table.
1309 void DwarfDebug::emitAccelNamespaces() {
1310 emitAccel(AccelNamespace,
1311 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1315 // Emit type dies into a hashed accelerator table.
1316 void DwarfDebug::emitAccelTypes() {
1317 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1321 // Public name handling.
1322 // The format for the various pubnames:
1324 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1325 // for the DIE that is named.
1327 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1328 // into the CU and the index value is computed according to the type of value
1329 // for the DIE that is named.
1331 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1332 // it's the offset within the debug_info/debug_types dwo section, however, the
1333 // reference in the pubname header doesn't change.
1335 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1336 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1338 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1340 // We could have a specification DIE that has our most of our knowledge,
1341 // look for that now.
1342 if (DIEValue SpecVal = Die->findAttribute(dwarf::DW_AT_specification)) {
1343 DIE &SpecDIE = SpecVal.getDIEEntry().getEntry();
1344 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1345 Linkage = dwarf::GIEL_EXTERNAL;
1346 } else if (Die->findAttribute(dwarf::DW_AT_external))
1347 Linkage = dwarf::GIEL_EXTERNAL;
1349 switch (Die->getTag()) {
1350 case dwarf::DW_TAG_class_type:
1351 case dwarf::DW_TAG_structure_type:
1352 case dwarf::DW_TAG_union_type:
1353 case dwarf::DW_TAG_enumeration_type:
1354 return dwarf::PubIndexEntryDescriptor(
1355 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1356 ? dwarf::GIEL_STATIC
1357 : dwarf::GIEL_EXTERNAL);
1358 case dwarf::DW_TAG_typedef:
1359 case dwarf::DW_TAG_base_type:
1360 case dwarf::DW_TAG_subrange_type:
1361 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1362 case dwarf::DW_TAG_namespace:
1363 return dwarf::GIEK_TYPE;
1364 case dwarf::DW_TAG_subprogram:
1365 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1366 case dwarf::DW_TAG_variable:
1367 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1368 case dwarf::DW_TAG_enumerator:
1369 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1370 dwarf::GIEL_STATIC);
1372 return dwarf::GIEK_NONE;
1376 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1378 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1379 MCSection *PSec = GnuStyle
1380 ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1381 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1383 emitDebugPubSection(GnuStyle, PSec, "Names",
1384 &DwarfCompileUnit::getGlobalNames);
1387 void DwarfDebug::emitDebugPubSection(
1388 bool GnuStyle, MCSection *PSec, StringRef Name,
1389 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1390 for (const auto &NU : CUMap) {
1391 DwarfCompileUnit *TheU = NU.second;
1393 const auto &Globals = (TheU->*Accessor)();
1395 if (Globals.empty())
1398 if (auto *Skeleton = TheU->getSkeleton())
1401 // Start the dwarf pubnames section.
1402 Asm->OutStreamer->SwitchSection(PSec);
1405 Asm->OutStreamer->AddComment("Length of Public " + Name + " Info");
1406 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1407 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1408 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1410 Asm->OutStreamer->EmitLabel(BeginLabel);
1412 Asm->OutStreamer->AddComment("DWARF Version");
1413 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1415 Asm->OutStreamer->AddComment("Offset of Compilation Unit Info");
1416 Asm->emitDwarfSymbolReference(TheU->getLabelBegin());
1418 Asm->OutStreamer->AddComment("Compilation Unit Length");
1419 Asm->EmitInt32(TheU->getLength());
1421 // Emit the pubnames for this compilation unit.
1422 for (const auto &GI : Globals) {
1423 const char *Name = GI.getKeyData();
1424 const DIE *Entity = GI.second;
1426 Asm->OutStreamer->AddComment("DIE offset");
1427 Asm->EmitInt32(Entity->getOffset());
1430 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1431 Asm->OutStreamer->AddComment(
1432 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1433 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1434 Asm->EmitInt8(Desc.toBits());
1437 Asm->OutStreamer->AddComment("External Name");
1438 Asm->OutStreamer->EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1441 Asm->OutStreamer->AddComment("End Mark");
1443 Asm->OutStreamer->EmitLabel(EndLabel);
1447 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1448 MCSection *PSec = GnuStyle
1449 ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1450 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1452 emitDebugPubSection(GnuStyle, PSec, "Types",
1453 &DwarfCompileUnit::getGlobalTypes);
1456 // Emit visible names into a debug str section.
1457 void DwarfDebug::emitDebugStr() {
1458 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1459 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1462 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1463 const DebugLocStream::Entry &Entry) {
1464 auto &&Comments = DebugLocs.getComments(Entry);
1465 auto Comment = Comments.begin();
1466 auto End = Comments.end();
1467 for (uint8_t Byte : DebugLocs.getBytes(Entry))
1468 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1471 static void emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
1472 ByteStreamer &Streamer,
1473 const DebugLocEntry::Value &Value,
1474 unsigned PieceOffsetInBits) {
1475 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1476 AP.getDwarfDebug()->getDwarfVersion(),
1479 if (Value.isInt()) {
1480 if (BT && (BT->getEncoding() == dwarf::DW_ATE_signed ||
1481 BT->getEncoding() == dwarf::DW_ATE_signed_char))
1482 DwarfExpr.AddSignedConstant(Value.getInt());
1484 DwarfExpr.AddUnsignedConstant(Value.getInt());
1485 } else if (Value.isLocation()) {
1486 MachineLocation Loc = Value.getLoc();
1487 const DIExpression *Expr = Value.getExpression();
1488 if (!Expr || !Expr->getNumElements())
1490 AP.EmitDwarfRegOp(Streamer, Loc);
1492 // Complex address entry.
1493 if (Loc.getOffset()) {
1494 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1495 DwarfExpr.AddExpression(Expr->expr_op_begin(), Expr->expr_op_end(),
1498 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1502 // else ... ignore constant fp. There is not any good way to
1503 // to represent them here in dwarf.
1507 void DebugLocEntry::finalize(const AsmPrinter &AP,
1508 DebugLocStream::ListBuilder &List,
1509 const DIBasicType *BT) {
1510 DebugLocStream::EntryBuilder Entry(List, Begin, End);
1511 BufferByteStreamer Streamer = Entry.getStreamer();
1512 const DebugLocEntry::Value &Value = Values[0];
1513 if (Value.isBitPiece()) {
1514 // Emit all pieces that belong to the same variable and range.
1515 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1516 return P.isBitPiece();
1517 }) && "all values are expected to be pieces");
1518 assert(std::is_sorted(Values.begin(), Values.end()) &&
1519 "pieces are expected to be sorted");
1521 unsigned Offset = 0;
1522 for (auto Piece : Values) {
1523 const DIExpression *Expr = Piece.getExpression();
1524 unsigned PieceOffset = Expr->getBitPieceOffset();
1525 unsigned PieceSize = Expr->getBitPieceSize();
1526 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1527 if (Offset < PieceOffset) {
1528 // The DWARF spec seriously mandates pieces with no locations for gaps.
1529 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1530 AP.getDwarfDebug()->getDwarfVersion(),
1532 Expr.AddOpPiece(PieceOffset-Offset, 0);
1533 Offset += PieceOffset-Offset;
1535 Offset += PieceSize;
1537 emitDebugLocValue(AP, BT, Streamer, Piece, PieceOffset);
1540 assert(Values.size() == 1 && "only pieces may have >1 value");
1541 emitDebugLocValue(AP, BT, Streamer, Value, 0);
1545 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry) {
1547 Asm->OutStreamer->AddComment("Loc expr size");
1548 Asm->EmitInt16(DebugLocs.getBytes(Entry).size());
1551 APByteStreamer Streamer(*Asm);
1552 emitDebugLocEntry(Streamer, Entry);
1555 // Emit locations into the debug loc section.
1556 void DwarfDebug::emitDebugLoc() {
1557 // Start the dwarf loc section.
1558 Asm->OutStreamer->SwitchSection(
1559 Asm->getObjFileLowering().getDwarfLocSection());
1560 unsigned char Size = Asm->getDataLayout().getPointerSize();
1561 for (const auto &List : DebugLocs.getLists()) {
1562 Asm->OutStreamer->EmitLabel(List.Label);
1563 const DwarfCompileUnit *CU = List.CU;
1564 for (const auto &Entry : DebugLocs.getEntries(List)) {
1565 // Set up the range. This range is relative to the entry point of the
1566 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1567 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1568 if (auto *Base = CU->getBaseAddress()) {
1569 Asm->EmitLabelDifference(Entry.BeginSym, Base, Size);
1570 Asm->EmitLabelDifference(Entry.EndSym, Base, Size);
1572 Asm->OutStreamer->EmitSymbolValue(Entry.BeginSym, Size);
1573 Asm->OutStreamer->EmitSymbolValue(Entry.EndSym, Size);
1576 emitDebugLocEntryLocation(Entry);
1578 Asm->OutStreamer->EmitIntValue(0, Size);
1579 Asm->OutStreamer->EmitIntValue(0, Size);
1583 void DwarfDebug::emitDebugLocDWO() {
1584 Asm->OutStreamer->SwitchSection(
1585 Asm->getObjFileLowering().getDwarfLocDWOSection());
1586 for (const auto &List : DebugLocs.getLists()) {
1587 Asm->OutStreamer->EmitLabel(List.Label);
1588 for (const auto &Entry : DebugLocs.getEntries(List)) {
1589 // Just always use start_length for now - at least that's one address
1590 // rather than two. We could get fancier and try to, say, reuse an
1591 // address we know we've emitted elsewhere (the start of the function?
1592 // The start of the CU or CU subrange that encloses this range?)
1593 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1594 unsigned idx = AddrPool.getIndex(Entry.BeginSym);
1595 Asm->EmitULEB128(idx);
1596 Asm->EmitLabelDifference(Entry.EndSym, Entry.BeginSym, 4);
1598 emitDebugLocEntryLocation(Entry);
1600 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1605 const MCSymbol *Start, *End;
1608 // Emit a debug aranges section, containing a CU lookup for any
1609 // address we can tie back to a CU.
1610 void DwarfDebug::emitDebugARanges() {
1611 // Provides a unique id per text section.
1612 MapVector<MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1614 // Filter labels by section.
1615 for (const SymbolCU &SCU : ArangeLabels) {
1616 if (SCU.Sym->isInSection()) {
1617 // Make a note of this symbol and it's section.
1618 MCSection *Section = &SCU.Sym->getSection();
1619 if (!Section->getKind().isMetadata())
1620 SectionMap[Section].push_back(SCU);
1622 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1623 // appear in the output. This sucks as we rely on sections to build
1624 // arange spans. We can do it without, but it's icky.
1625 SectionMap[nullptr].push_back(SCU);
1629 // Add terminating symbols for each section.
1630 for (const auto &I : SectionMap) {
1631 MCSection *Section = I.first;
1632 MCSymbol *Sym = nullptr;
1635 Sym = Asm->OutStreamer->endSection(Section);
1637 // Insert a final terminator.
1638 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1641 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1643 for (auto &I : SectionMap) {
1644 const MCSection *Section = I.first;
1645 SmallVector<SymbolCU, 8> &List = I.second;
1646 if (List.size() < 2)
1649 // If we have no section (e.g. common), just write out
1650 // individual spans for each symbol.
1652 for (const SymbolCU &Cur : List) {
1654 Span.Start = Cur.Sym;
1657 Spans[Cur.CU].push_back(Span);
1662 // Sort the symbols by offset within the section.
1663 std::sort(List.begin(), List.end(),
1664 [&](const SymbolCU &A, const SymbolCU &B) {
1665 unsigned IA = A.Sym ? Asm->OutStreamer->GetSymbolOrder(A.Sym) : 0;
1666 unsigned IB = B.Sym ? Asm->OutStreamer->GetSymbolOrder(B.Sym) : 0;
1668 // Symbols with no order assigned should be placed at the end.
1669 // (e.g. section end labels)
1677 // Build spans between each label.
1678 const MCSymbol *StartSym = List[0].Sym;
1679 for (size_t n = 1, e = List.size(); n < e; n++) {
1680 const SymbolCU &Prev = List[n - 1];
1681 const SymbolCU &Cur = List[n];
1683 // Try and build the longest span we can within the same CU.
1684 if (Cur.CU != Prev.CU) {
1686 Span.Start = StartSym;
1688 Spans[Prev.CU].push_back(Span);
1694 // Start the dwarf aranges section.
1695 Asm->OutStreamer->SwitchSection(
1696 Asm->getObjFileLowering().getDwarfARangesSection());
1698 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1700 // Build a list of CUs used.
1701 std::vector<DwarfCompileUnit *> CUs;
1702 for (const auto &it : Spans) {
1703 DwarfCompileUnit *CU = it.first;
1707 // Sort the CU list (again, to ensure consistent output order).
1708 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1709 return A->getUniqueID() < B->getUniqueID();
1712 // Emit an arange table for each CU we used.
1713 for (DwarfCompileUnit *CU : CUs) {
1714 std::vector<ArangeSpan> &List = Spans[CU];
1716 // Describe the skeleton CU's offset and length, not the dwo file's.
1717 if (auto *Skel = CU->getSkeleton())
1720 // Emit size of content not including length itself.
1721 unsigned ContentSize =
1722 sizeof(int16_t) + // DWARF ARange version number
1723 sizeof(int32_t) + // Offset of CU in the .debug_info section
1724 sizeof(int8_t) + // Pointer Size (in bytes)
1725 sizeof(int8_t); // Segment Size (in bytes)
1727 unsigned TupleSize = PtrSize * 2;
1729 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1731 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1733 ContentSize += Padding;
1734 ContentSize += (List.size() + 1) * TupleSize;
1736 // For each compile unit, write the list of spans it covers.
1737 Asm->OutStreamer->AddComment("Length of ARange Set");
1738 Asm->EmitInt32(ContentSize);
1739 Asm->OutStreamer->AddComment("DWARF Arange version number");
1740 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1741 Asm->OutStreamer->AddComment("Offset Into Debug Info Section");
1742 Asm->emitDwarfSymbolReference(CU->getLabelBegin());
1743 Asm->OutStreamer->AddComment("Address Size (in bytes)");
1744 Asm->EmitInt8(PtrSize);
1745 Asm->OutStreamer->AddComment("Segment Size (in bytes)");
1748 Asm->OutStreamer->EmitFill(Padding, 0xff);
1750 for (const ArangeSpan &Span : List) {
1751 Asm->EmitLabelReference(Span.Start, PtrSize);
1753 // Calculate the size as being from the span start to it's end.
1755 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1757 // For symbols without an end marker (e.g. common), we
1758 // write a single arange entry containing just that one symbol.
1759 uint64_t Size = SymSize[Span.Start];
1763 Asm->OutStreamer->EmitIntValue(Size, PtrSize);
1767 Asm->OutStreamer->AddComment("ARange terminator");
1768 Asm->OutStreamer->EmitIntValue(0, PtrSize);
1769 Asm->OutStreamer->EmitIntValue(0, PtrSize);
1773 // Emit visible names into a debug ranges section.
1774 void DwarfDebug::emitDebugRanges() {
1775 // Start the dwarf ranges section.
1776 Asm->OutStreamer->SwitchSection(
1777 Asm->getObjFileLowering().getDwarfRangesSection());
1779 // Size for our labels.
1780 unsigned char Size = Asm->getDataLayout().getPointerSize();
1782 // Grab the specific ranges for the compile units in the module.
1783 for (const auto &I : CUMap) {
1784 DwarfCompileUnit *TheCU = I.second;
1786 if (auto *Skel = TheCU->getSkeleton())
1789 // Iterate over the misc ranges for the compile units in the module.
1790 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1791 // Emit our symbol so we can find the beginning of the range.
1792 Asm->OutStreamer->EmitLabel(List.getSym());
1794 for (const RangeSpan &Range : List.getRanges()) {
1795 const MCSymbol *Begin = Range.getStart();
1796 const MCSymbol *End = Range.getEnd();
1797 assert(Begin && "Range without a begin symbol?");
1798 assert(End && "Range without an end symbol?");
1799 if (auto *Base = TheCU->getBaseAddress()) {
1800 Asm->EmitLabelDifference(Begin, Base, Size);
1801 Asm->EmitLabelDifference(End, Base, Size);
1803 Asm->OutStreamer->EmitSymbolValue(Begin, Size);
1804 Asm->OutStreamer->EmitSymbolValue(End, Size);
1808 // And terminate the list with two 0 values.
1809 Asm->OutStreamer->EmitIntValue(0, Size);
1810 Asm->OutStreamer->EmitIntValue(0, Size);
1815 // DWARF5 Experimental Separate Dwarf emitters.
1817 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1818 std::unique_ptr<DwarfUnit> NewU) {
1819 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1820 U.getCUNode()->getSplitDebugFilename());
1822 if (!CompilationDir.empty())
1823 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1825 addGnuPubAttributes(*NewU, Die);
1827 SkeletonHolder.addUnit(std::move(NewU));
1830 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1831 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1832 // DW_AT_addr_base, DW_AT_ranges_base.
1833 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1835 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1836 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1837 DwarfCompileUnit &NewCU = *OwnedUnit;
1838 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1840 NewCU.initStmtList();
1842 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1847 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1848 // compile units that would normally be in debug_info.
1849 void DwarfDebug::emitDebugInfoDWO() {
1850 assert(useSplitDwarf() && "No split dwarf debug info?");
1851 // Don't emit relocations into the dwo file.
1852 InfoHolder.emitUnits(/* UseOffsets */ true);
1855 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1856 // abbreviations for the .debug_info.dwo section.
1857 void DwarfDebug::emitDebugAbbrevDWO() {
1858 assert(useSplitDwarf() && "No split dwarf?");
1859 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1862 void DwarfDebug::emitDebugLineDWO() {
1863 assert(useSplitDwarf() && "No split dwarf?");
1864 Asm->OutStreamer->SwitchSection(
1865 Asm->getObjFileLowering().getDwarfLineDWOSection());
1866 SplitTypeUnitFileTable.Emit(*Asm->OutStreamer);
1869 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1870 // string section and is identical in format to traditional .debug_str
1872 void DwarfDebug::emitDebugStrDWO() {
1873 assert(useSplitDwarf() && "No split dwarf?");
1874 MCSection *OffSec = Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1875 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1879 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1880 if (!useSplitDwarf())
1883 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode()->getDirectory());
1884 return &SplitTypeUnitFileTable;
1887 static uint64_t makeTypeSignature(StringRef Identifier) {
1889 Hash.update(Identifier);
1890 // ... take the least significant 8 bytes and return those. Our MD5
1891 // implementation always returns its results in little endian, swap bytes
1893 MD5::MD5Result Result;
1895 return support::endian::read64le(Result + 8);
1898 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1899 StringRef Identifier, DIE &RefDie,
1900 const DICompositeType *CTy) {
1901 // Fast path if we're building some type units and one has already used the
1902 // address pool we know we're going to throw away all this work anyway, so
1903 // don't bother building dependent types.
1904 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1907 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1909 CU.addDIETypeSignature(RefDie, *TU);
1913 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1914 AddrPool.resetUsedFlag();
1916 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1917 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1918 this, &InfoHolder, getDwoLineTable(CU));
1919 DwarfTypeUnit &NewTU = *OwnedUnit;
1920 DIE &UnitDie = NewTU.getUnitDie();
1922 TypeUnitsUnderConstruction.push_back(
1923 std::make_pair(std::move(OwnedUnit), CTy));
1925 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1928 uint64_t Signature = makeTypeSignature(Identifier);
1929 NewTU.setTypeSignature(Signature);
1931 if (useSplitDwarf())
1932 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1934 CU.applyStmtList(UnitDie);
1936 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1939 NewTU.setType(NewTU.createTypeDIE(CTy));
1942 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1943 TypeUnitsUnderConstruction.clear();
1945 // Types referencing entries in the address table cannot be placed in type
1947 if (AddrPool.hasBeenUsed()) {
1949 // Remove all the types built while building this type.
1950 // This is pessimistic as some of these types might not be dependent on
1951 // the type that used an address.
1952 for (const auto &TU : TypeUnitsToAdd)
1953 DwarfTypeUnits.erase(TU.second);
1955 // Construct this type in the CU directly.
1956 // This is inefficient because all the dependent types will be rebuilt
1957 // from scratch, including building them in type units, discovering that
1958 // they depend on addresses, throwing them out and rebuilding them.
1959 CU.constructTypeDIE(RefDie, cast<DICompositeType>(CTy));
1963 // If the type wasn't dependent on fission addresses, finish adding the type
1964 // and all its dependent types.
1965 for (auto &TU : TypeUnitsToAdd)
1966 InfoHolder.addUnit(std::move(TU.first));
1968 CU.addDIETypeSignature(RefDie, NewTU);
1971 // Accelerator table mutators - add each name along with its companion
1972 // DIE to the proper table while ensuring that the name that we're going
1973 // to reference is in the string table. We do this since the names we
1974 // add may not only be identical to the names in the DIE.
1975 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
1976 if (!useDwarfAccelTables())
1978 AccelNames.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
1981 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
1982 if (!useDwarfAccelTables())
1984 AccelObjC.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
1987 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
1988 if (!useDwarfAccelTables())
1990 AccelNamespace.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
1993 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
1994 if (!useDwarfAccelTables())
1996 AccelTypes.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);