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 "DwarfCompileUnit.h"
18 #include "DwarfExpression.h"
19 #include "DwarfUnit.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/ADT/StringExtras.h"
23 #include "llvm/ADT/Triple.h"
24 #include "llvm/CodeGen/DIE.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineModuleInfo.h"
27 #include "llvm/IR/Constants.h"
28 #include "llvm/IR/DIBuilder.h"
29 #include "llvm/IR/DataLayout.h"
30 #include "llvm/IR/DebugInfo.h"
31 #include "llvm/IR/Instructions.h"
32 #include "llvm/IR/Module.h"
33 #include "llvm/IR/ValueHandle.h"
34 #include "llvm/MC/MCAsmInfo.h"
35 #include "llvm/MC/MCSection.h"
36 #include "llvm/MC/MCStreamer.h"
37 #include "llvm/MC/MCSymbol.h"
38 #include "llvm/Support/CommandLine.h"
39 #include "llvm/Support/Debug.h"
40 #include "llvm/Support/Dwarf.h"
41 #include "llvm/Support/Endian.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/FormattedStream.h"
44 #include "llvm/Support/LEB128.h"
45 #include "llvm/Support/MD5.h"
46 #include "llvm/Support/Path.h"
47 #include "llvm/Support/Timer.h"
48 #include "llvm/Support/raw_ostream.h"
49 #include "llvm/Target/TargetFrameLowering.h"
50 #include "llvm/Target/TargetLoweringObjectFile.h"
51 #include "llvm/Target/TargetMachine.h"
52 #include "llvm/Target/TargetOptions.h"
53 #include "llvm/Target/TargetRegisterInfo.h"
54 #include "llvm/Target/TargetSubtargetInfo.h"
57 #define DEBUG_TYPE "dwarfdebug"
60 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
61 cl::desc("Disable debug info printing"));
63 static cl::opt<bool> UnknownLocations(
64 "use-unknown-locations", cl::Hidden,
65 cl::desc("Make an absence of debug location information explicit."),
69 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
70 cl::desc("Generate GNU-style pubnames and pubtypes"),
73 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
75 cl::desc("Generate dwarf aranges"),
79 enum DefaultOnOff { Default, Enable, Disable };
82 static cl::opt<DefaultOnOff>
83 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
84 cl::desc("Output prototype dwarf accelerator tables."),
85 cl::values(clEnumVal(Default, "Default for platform"),
86 clEnumVal(Enable, "Enabled"),
87 clEnumVal(Disable, "Disabled"), clEnumValEnd),
90 static cl::opt<DefaultOnOff>
91 SplitDwarf("split-dwarf", cl::Hidden,
92 cl::desc("Output DWARF5 split debug info."),
93 cl::values(clEnumVal(Default, "Default for platform"),
94 clEnumVal(Enable, "Enabled"),
95 clEnumVal(Disable, "Disabled"), clEnumValEnd),
98 static cl::opt<DefaultOnOff>
99 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
100 cl::desc("Generate DWARF pubnames and pubtypes sections"),
101 cl::values(clEnumVal(Default, "Default for platform"),
102 clEnumVal(Enable, "Enabled"),
103 clEnumVal(Disable, "Disabled"), clEnumValEnd),
106 static const char *const DWARFGroupName = "DWARF Emission";
107 static const char *const DbgTimerName = "DWARF Debug Writer";
109 void DebugLocDwarfExpression::EmitOp(uint8_t Op, const char *Comment) {
111 Op, Comment ? Twine(Comment) + " " + dwarf::OperationEncodingString(Op)
112 : dwarf::OperationEncodingString(Op));
115 void DebugLocDwarfExpression::EmitSigned(int64_t Value) {
116 BS.EmitSLEB128(Value, Twine(Value));
119 void DebugLocDwarfExpression::EmitUnsigned(uint64_t Value) {
120 BS.EmitULEB128(Value, Twine(Value));
123 bool DebugLocDwarfExpression::isFrameRegister(unsigned MachineReg) {
124 // This information is not available while emitting .debug_loc entries.
128 //===----------------------------------------------------------------------===//
130 /// resolve - Look in the DwarfDebug map for the MDNode that
131 /// corresponds to the reference.
132 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
133 return DD->resolve(Ref);
136 bool DbgVariable::isBlockByrefVariable() const {
137 assert(Var && "Invalid complex DbgVariable!");
138 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
141 DIType DbgVariable::getType() const {
142 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
143 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
144 // addresses instead.
145 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
146 /* Byref variables, in Blocks, are declared by the programmer as
147 "SomeType VarName;", but the compiler creates a
148 __Block_byref_x_VarName struct, and gives the variable VarName
149 either the struct, or a pointer to the struct, as its type. This
150 is necessary for various behind-the-scenes things the compiler
151 needs to do with by-reference variables in blocks.
153 However, as far as the original *programmer* is concerned, the
154 variable should still have type 'SomeType', as originally declared.
156 The following function dives into the __Block_byref_x_VarName
157 struct to find the original type of the variable. This will be
158 passed back to the code generating the type for the Debug
159 Information Entry for the variable 'VarName'. 'VarName' will then
160 have the original type 'SomeType' in its debug information.
162 The original type 'SomeType' will be the type of the field named
163 'VarName' inside the __Block_byref_x_VarName struct.
165 NOTE: In order for this to not completely fail on the debugger
166 side, the Debug Information Entry for the variable VarName needs to
167 have a DW_AT_location that tells the debugger how to unwind through
168 the pointers and __Block_byref_x_VarName struct to find the actual
169 value of the variable. The function addBlockByrefType does this. */
171 uint16_t tag = Ty.getTag();
173 if (tag == dwarf::DW_TAG_pointer_type)
174 subType = resolve(DITypeRef(cast<MDDerivedType>(Ty)->getBaseType()));
176 DIArray Elements(cast<MDCompositeTypeBase>(subType)->getElements());
177 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
178 DIDerivedType DT = cast<MDDerivedTypeBase>(Elements[i]);
179 if (getName() == DT.getName())
180 return (resolve(DT.getTypeDerivedFrom()));
186 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
187 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
188 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
189 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
191 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
192 : Asm(A), MMI(Asm->MMI), PrevLabel(nullptr),
193 InfoHolder(A, "info_string", DIEValueAllocator),
194 UsedNonDefaultText(false),
195 SkeletonHolder(A, "skel_string", DIEValueAllocator),
196 IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
197 IsPS4(Triple(A->getTargetTriple()).isPS4()),
198 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
199 dwarf::DW_FORM_data4)),
200 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
201 dwarf::DW_FORM_data4)),
202 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
203 dwarf::DW_FORM_data4)),
204 AccelTypes(TypeAtoms) {
209 // Turn on accelerator tables for Darwin by default, pubnames by
210 // default for non-Darwin/PS4, and handle split dwarf.
211 if (DwarfAccelTables == Default)
212 HasDwarfAccelTables = IsDarwin;
214 HasDwarfAccelTables = DwarfAccelTables == Enable;
216 if (SplitDwarf == Default)
217 HasSplitDwarf = false;
219 HasSplitDwarf = SplitDwarf == Enable;
221 if (DwarfPubSections == Default)
222 HasDwarfPubSections = !IsDarwin && !IsPS4;
224 HasDwarfPubSections = DwarfPubSections == Enable;
226 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
227 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
228 : MMI->getModule()->getDwarfVersion();
230 // Darwin and PS4 use the standard TLS opcode (defined in DWARF 3).
231 // Everybody else uses GNU's.
232 UseGNUTLSOpcode = !(IsDarwin || IsPS4) || DwarfVersion < 3;
234 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
237 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
242 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
243 DwarfDebug::~DwarfDebug() { }
245 static bool isObjCClass(StringRef Name) {
246 return Name.startswith("+") || Name.startswith("-");
249 static bool hasObjCCategory(StringRef Name) {
250 if (!isObjCClass(Name))
253 return Name.find(") ") != StringRef::npos;
256 static void getObjCClassCategory(StringRef In, StringRef &Class,
257 StringRef &Category) {
258 if (!hasObjCCategory(In)) {
259 Class = In.slice(In.find('[') + 1, In.find(' '));
264 Class = In.slice(In.find('[') + 1, In.find('('));
265 Category = In.slice(In.find('[') + 1, In.find(' '));
269 static StringRef getObjCMethodName(StringRef In) {
270 return In.slice(In.find(' ') + 1, In.find(']'));
273 // Add the various names to the Dwarf accelerator table names.
274 // TODO: Determine whether or not we should add names for programs
275 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
276 // is only slightly different than the lookup of non-standard ObjC names.
277 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
278 if (!SP.isDefinition())
280 addAccelName(SP.getName(), Die);
282 // If the linkage name is different than the name, go ahead and output
283 // that as well into the name table.
284 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
285 addAccelName(SP.getLinkageName(), Die);
287 // If this is an Objective-C selector name add it to the ObjC accelerator
289 if (isObjCClass(SP.getName())) {
290 StringRef Class, Category;
291 getObjCClassCategory(SP.getName(), Class, Category);
292 addAccelObjC(Class, Die);
294 addAccelObjC(Category, Die);
295 // Also add the base method name to the name table.
296 addAccelName(getObjCMethodName(SP.getName()), Die);
300 /// isSubprogramContext - Return true if Context is either a subprogram
301 /// or another context nested inside a subprogram.
302 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
305 if (isa<MDSubprogram>(Context))
307 if (DIType T = dyn_cast<MDType>(Context))
308 return isSubprogramContext(resolve(T.getContext()));
312 /// Check whether we should create a DIE for the given Scope, return true
313 /// if we don't create a DIE (the corresponding DIE is null).
314 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
315 if (Scope->isAbstractScope())
318 // We don't create a DIE if there is no Range.
319 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
323 if (Ranges.size() > 1)
326 // We don't create a DIE if we have a single Range and the end label
328 return !getLabelAfterInsn(Ranges.front().second);
331 template <typename Func> void forBothCUs(DwarfCompileUnit &CU, Func F) {
333 if (auto *SkelCU = CU.getSkeleton())
337 void DwarfDebug::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
338 assert(Scope && Scope->getScopeNode());
339 assert(Scope->isAbstractScope());
340 assert(!Scope->getInlinedAt());
342 const MDNode *SP = Scope->getScopeNode();
344 ProcessedSPNodes.insert(SP);
346 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
347 // was inlined from another compile unit.
348 auto &CU = SPMap[SP];
349 forBothCUs(*CU, [&](DwarfCompileUnit &CU) {
350 CU.constructAbstractSubprogramScopeDIE(Scope);
354 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
355 if (!GenerateGnuPubSections)
358 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
361 // Create new DwarfCompileUnit for the given metadata node with tag
362 // DW_TAG_compile_unit.
363 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
364 StringRef FN = DIUnit.getFilename();
365 CompilationDir = DIUnit.getDirectory();
367 auto OwnedUnit = make_unique<DwarfCompileUnit>(
368 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
369 DwarfCompileUnit &NewCU = *OwnedUnit;
370 DIE &Die = NewCU.getUnitDie();
371 InfoHolder.addUnit(std::move(OwnedUnit));
373 NewCU.setSkeleton(constructSkeletonCU(NewCU));
375 // LTO with assembly output shares a single line table amongst multiple CUs.
376 // To avoid the compilation directory being ambiguous, let the line table
377 // explicitly describe the directory of all files, never relying on the
378 // compilation directory.
379 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
380 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
381 NewCU.getUniqueID(), CompilationDir);
383 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
384 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
385 DIUnit.getLanguage());
386 NewCU.addString(Die, dwarf::DW_AT_name, FN);
388 if (!useSplitDwarf()) {
389 NewCU.initStmtList();
391 // If we're using split dwarf the compilation dir is going to be in the
392 // skeleton CU and so we don't need to duplicate it here.
393 if (!CompilationDir.empty())
394 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
396 addGnuPubAttributes(NewCU, Die);
399 if (DIUnit.isOptimized())
400 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
402 StringRef Flags = DIUnit.getFlags();
404 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
406 if (unsigned RVer = DIUnit.getRunTimeVersion())
407 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
408 dwarf::DW_FORM_data1, RVer);
411 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection());
413 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
415 CUMap.insert(std::make_pair(DIUnit, &NewCU));
416 CUDieMap.insert(std::make_pair(&Die, &NewCU));
420 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
422 DIImportedEntity Module = cast<MDImportedEntity>(N);
423 if (DIE *D = TheCU.getOrCreateContextDIE(Module->getScope()))
424 D->addChild(TheCU.constructImportedEntityDIE(Module));
427 // Emit all Dwarf sections that should come prior to the content. Create
428 // global DIEs and emit initial debug info sections. This is invoked by
429 // the target AsmPrinter.
430 void DwarfDebug::beginModule() {
431 if (DisableDebugInfoPrinting)
434 const Module *M = MMI->getModule();
436 FunctionDIs = makeSubprogramMap(*M);
438 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
441 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
443 SingleCU = CU_Nodes->getNumOperands() == 1;
445 for (MDNode *N : CU_Nodes->operands()) {
446 DICompileUnit CUNode = cast<MDCompileUnit>(N);
447 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
448 for (auto *IE : CUNode->getImportedEntities())
449 ScopesWithImportedEntities.push_back(std::make_pair(IE->getScope(), IE));
450 // Stable sort to preserve the order of appearance of imported entities.
451 // This is to avoid out-of-order processing of interdependent declarations
452 // within the same scope, e.g. { namespace A = base; namespace B = A; }
453 std::stable_sort(ScopesWithImportedEntities.begin(),
454 ScopesWithImportedEntities.end(), less_first());
455 for (auto *GV : CUNode->getGlobalVariables())
456 CU.getOrCreateGlobalVariableDIE(GV);
457 for (auto *SP : CUNode->getSubprograms())
458 SPMap.insert(std::make_pair(SP, &CU));
459 for (DIType Ty : CUNode->getEnumTypes()) {
460 // The enum types array by design contains pointers to
461 // MDNodes rather than DIRefs. Unique them here.
462 DIType UniqueTy = cast<MDType>(resolve(Ty.getRef()));
463 CU.getOrCreateTypeDIE(UniqueTy);
465 for (DIType Ty : CUNode->getRetainedTypes()) {
466 // The retained types array by design contains pointers to
467 // MDNodes rather than DIRefs. Unique them here.
468 DIType UniqueTy = cast<MDType>(resolve(Ty.getRef()));
469 CU.getOrCreateTypeDIE(UniqueTy);
471 // Emit imported_modules last so that the relevant context is already
473 for (auto *IE : CUNode->getImportedEntities())
474 constructAndAddImportedEntityDIE(CU, IE);
477 // Tell MMI that we have debug info.
478 MMI->setDebugInfoAvailability(true);
481 void DwarfDebug::finishVariableDefinitions() {
482 for (const auto &Var : ConcreteVariables) {
483 DIE *VariableDie = Var->getDIE();
485 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
486 // in the ConcreteVariables list, rather than looking it up again here.
487 // DIE::getUnit isn't simple - it walks parent pointers, etc.
488 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
490 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
491 if (AbsVar && AbsVar->getDIE()) {
492 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
495 Unit->applyVariableAttributes(*Var, *VariableDie);
499 void DwarfDebug::finishSubprogramDefinitions() {
500 for (const auto &P : SPMap)
501 forBothCUs(*P.second, [&](DwarfCompileUnit &CU) {
502 CU.finishSubprogramDefinition(cast<MDSubprogram>(P.first));
507 // Collect info for variables that were optimized out.
508 void DwarfDebug::collectDeadVariables() {
509 const Module *M = MMI->getModule();
511 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
512 for (MDNode *N : CU_Nodes->operands()) {
513 DICompileUnit TheCU = cast<MDCompileUnit>(N);
514 // Construct subprogram DIE and add variables DIEs.
515 DwarfCompileUnit *SPCU =
516 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
517 assert(SPCU && "Unable to find Compile Unit!");
518 for (auto *SP : TheCU->getSubprograms()) {
519 if (ProcessedSPNodes.count(SP) != 0)
521 SPCU->collectDeadVariables(SP);
527 void DwarfDebug::finalizeModuleInfo() {
528 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
530 finishSubprogramDefinitions();
532 finishVariableDefinitions();
534 // Collect info for variables that were optimized out.
535 collectDeadVariables();
537 // Handle anything that needs to be done on a per-unit basis after
538 // all other generation.
539 for (const auto &P : CUMap) {
540 auto &TheCU = *P.second;
541 // Emit DW_AT_containing_type attribute to connect types with their
542 // vtable holding type.
543 TheCU.constructContainingTypeDIEs();
545 // Add CU specific attributes if we need to add any.
546 // If we're splitting the dwarf out now that we've got the entire
547 // CU then add the dwo id to it.
548 auto *SkCU = TheCU.getSkeleton();
549 if (useSplitDwarf()) {
550 // Emit a unique identifier for this CU.
551 uint64_t ID = DIEHash(Asm).computeCUSignature(TheCU.getUnitDie());
552 TheCU.addUInt(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
553 dwarf::DW_FORM_data8, ID);
554 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
555 dwarf::DW_FORM_data8, ID);
557 // We don't keep track of which addresses are used in which CU so this
558 // is a bit pessimistic under LTO.
559 if (!AddrPool.isEmpty()) {
560 const MCSymbol *Sym = TLOF.getDwarfAddrSection()->getBeginSymbol();
561 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_addr_base,
564 if (!SkCU->getRangeLists().empty()) {
565 const MCSymbol *Sym = TLOF.getDwarfRangesSection()->getBeginSymbol();
566 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
571 // If we have code split among multiple sections or non-contiguous
572 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
573 // remain in the .o file, otherwise add a DW_AT_low_pc.
574 // FIXME: We should use ranges allow reordering of code ala
575 // .subsections_via_symbols in mach-o. This would mean turning on
576 // ranges for all subprogram DIEs for mach-o.
577 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
578 if (unsigned NumRanges = TheCU.getRanges().size()) {
580 // A DW_AT_low_pc attribute may also be specified in combination with
581 // DW_AT_ranges to specify the default base address for use in
582 // location lists (see Section 2.6.2) and range lists (see Section
584 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
586 TheCU.setBaseAddress(TheCU.getRanges().front().getStart());
587 U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
591 // Compute DIE offsets and sizes.
592 InfoHolder.computeSizeAndOffsets();
594 SkeletonHolder.computeSizeAndOffsets();
597 // Emit all Dwarf sections that should come after the content.
598 void DwarfDebug::endModule() {
599 assert(CurFn == nullptr);
600 assert(CurMI == nullptr);
602 // If we aren't actually generating debug info (check beginModule -
603 // conditionalized on !DisableDebugInfoPrinting and the presence of the
604 // llvm.dbg.cu metadata node)
605 if (!MMI->hasDebugInfo())
608 // Finalize the debug info for the module.
609 finalizeModuleInfo();
616 // Emit info into a debug loc section.
619 // Corresponding abbreviations into a abbrev section.
622 // Emit all the DIEs into a debug info section.
625 // Emit info into a debug aranges section.
626 if (GenerateARangeSection)
629 // Emit info into a debug ranges section.
632 if (useSplitDwarf()) {
635 emitDebugAbbrevDWO();
637 // Emit DWO addresses.
638 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
641 // Emit info into the dwarf accelerator table sections.
642 if (useDwarfAccelTables()) {
645 emitAccelNamespaces();
649 // Emit the pubnames and pubtypes sections if requested.
650 if (HasDwarfPubSections) {
651 emitDebugPubNames(GenerateGnuPubSections);
652 emitDebugPubTypes(GenerateGnuPubSections);
657 AbstractVariables.clear();
660 // Find abstract variable, if any, associated with Var.
661 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
662 DIVariable &Cleansed) {
663 LLVMContext &Ctx = DV->getContext();
664 // More then one inlined variable corresponds to one abstract variable.
665 // FIXME: This duplication of variables when inlining should probably be
666 // removed. It's done to allow each DIVariable to describe its location
667 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
668 // make it accurate then remove this duplication/cleansing stuff.
669 Cleansed = cleanseInlinedVariable(DV, Ctx);
670 auto I = AbstractVariables.find(Cleansed);
671 if (I != AbstractVariables.end())
672 return I->second.get();
676 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
678 return getExistingAbstractVariable(DV, Cleansed);
681 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
682 LexicalScope *Scope) {
683 auto AbsDbgVariable = make_unique<DbgVariable>(Var, DIExpression(), this);
684 InfoHolder.addScopeVariable(Scope, AbsDbgVariable.get());
685 AbstractVariables[Var] = std::move(AbsDbgVariable);
688 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
689 const MDNode *ScopeNode) {
690 DIVariable Cleansed = DV;
691 if (getExistingAbstractVariable(DV, Cleansed))
694 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(
695 cast<MDLocalScope>(ScopeNode)));
699 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
700 const MDNode *ScopeNode) {
701 DIVariable Cleansed = DV;
702 if (getExistingAbstractVariable(DV, Cleansed))
705 if (LexicalScope *Scope =
706 LScopes.findAbstractScope(cast_or_null<MDLocalScope>(ScopeNode)))
707 createAbstractVariable(Cleansed, Scope);
710 // Collect variable information from side table maintained by MMI.
711 void DwarfDebug::collectVariableInfoFromMMITable(
712 SmallPtrSetImpl<const MDNode *> &Processed) {
713 for (const auto &VI : MMI->getVariableDbgInfo()) {
716 Processed.insert(VI.Var);
717 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
719 // If variable scope is not found then skip this variable.
723 DIVariable DV = cast<MDLocalVariable>(VI.Var);
724 assert(DV->isValidLocationForIntrinsic(VI.Loc) &&
725 "Expected inlined-at fields to agree");
726 DIExpression Expr = cast_or_null<MDExpression>(VI.Expr);
727 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
728 auto RegVar = make_unique<DbgVariable>(DV, Expr, this, VI.Slot);
729 if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
730 ConcreteVariables.push_back(std::move(RegVar));
734 // Get .debug_loc entry for the instruction range starting at MI.
735 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
736 const MDNode *Expr = MI->getDebugExpression();
737 const MDNode *Var = MI->getDebugVariable();
739 assert(MI->getNumOperands() == 4);
740 if (MI->getOperand(0).isReg()) {
741 MachineLocation MLoc;
742 // If the second operand is an immediate, this is a
743 // register-indirect address.
744 if (!MI->getOperand(1).isImm())
745 MLoc.set(MI->getOperand(0).getReg());
747 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
748 return DebugLocEntry::Value(Var, Expr, MLoc);
750 if (MI->getOperand(0).isImm())
751 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getImm());
752 if (MI->getOperand(0).isFPImm())
753 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getFPImm());
754 if (MI->getOperand(0).isCImm())
755 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getCImm());
757 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
760 /// Determine whether two variable pieces overlap.
761 static bool piecesOverlap(DIExpression P1, DIExpression P2) {
762 if (!P1->isBitPiece() || !P2->isBitPiece())
764 unsigned l1 = P1->getBitPieceOffset();
765 unsigned l2 = P2->getBitPieceOffset();
766 unsigned r1 = l1 + P1->getBitPieceSize();
767 unsigned r2 = l2 + P2->getBitPieceSize();
768 // True where [l1,r1[ and [r1,r2[ overlap.
769 return (l1 < r2) && (l2 < r1);
772 /// Build the location list for all DBG_VALUEs in the function that
773 /// describe the same variable. If the ranges of several independent
774 /// pieces of the same variable overlap partially, split them up and
775 /// combine the ranges. The resulting DebugLocEntries are will have
776 /// strict monotonically increasing begin addresses and will never
781 // Ranges History [var, loc, piece ofs size]
782 // 0 | [x, (reg0, piece 0, 32)]
783 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
785 // 3 | [clobber reg0]
786 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of
791 // [0-1] [x, (reg0, piece 0, 32)]
792 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
793 // [3-4] [x, (reg1, piece 32, 32)]
794 // [4- ] [x, (mem, piece 0, 64)]
796 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
797 const DbgValueHistoryMap::InstrRanges &Ranges) {
798 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
800 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
801 const MachineInstr *Begin = I->first;
802 const MachineInstr *End = I->second;
803 assert(Begin->isDebugValue() && "Invalid History entry");
805 // Check if a variable is inaccessible in this range.
806 if (Begin->getNumOperands() > 1 &&
807 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
812 // If this piece overlaps with any open ranges, truncate them.
813 DIExpression DIExpr = Begin->getDebugExpression();
814 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
815 [&](DebugLocEntry::Value R) {
816 return piecesOverlap(DIExpr, R.getExpression());
818 OpenRanges.erase(Last, OpenRanges.end());
820 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
821 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
823 const MCSymbol *EndLabel;
825 EndLabel = getLabelAfterInsn(End);
826 else if (std::next(I) == Ranges.end())
827 EndLabel = Asm->getFunctionEnd();
829 EndLabel = getLabelBeforeInsn(std::next(I)->first);
830 assert(EndLabel && "Forgot label after instruction ending a range!");
832 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
834 auto Value = getDebugLocValue(Begin);
835 DebugLocEntry Loc(StartLabel, EndLabel, Value);
836 bool couldMerge = false;
838 // If this is a piece, it may belong to the current DebugLocEntry.
839 if (DIExpr->isBitPiece()) {
840 // Add this value to the list of open ranges.
841 OpenRanges.push_back(Value);
843 // Attempt to add the piece to the last entry.
844 if (!DebugLoc.empty())
845 if (DebugLoc.back().MergeValues(Loc))
850 // Need to add a new DebugLocEntry. Add all values from still
851 // valid non-overlapping pieces.
852 if (OpenRanges.size())
853 Loc.addValues(OpenRanges);
855 DebugLoc.push_back(std::move(Loc));
858 // Attempt to coalesce the ranges of two otherwise identical
860 auto CurEntry = DebugLoc.rbegin();
861 auto PrevEntry = std::next(CurEntry);
862 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
866 dbgs() << CurEntry->getValues().size() << " Values:\n";
867 for (auto Value : CurEntry->getValues()) {
868 Value.getVariable()->dump();
869 Value.getExpression()->dump();
877 // Find variables for each lexical scope.
879 DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU, DISubprogram SP,
880 SmallPtrSetImpl<const MDNode *> &Processed) {
881 // Grab the variable info that was squirreled away in the MMI side-table.
882 collectVariableInfoFromMMITable(Processed);
884 for (const auto &I : DbgValues) {
885 DIVariable DV = cast<MDLocalVariable>(I.first);
886 if (Processed.count(DV))
889 // Instruction ranges, specifying where DV is accessible.
890 const auto &Ranges = I.second;
894 LexicalScope *Scope = nullptr;
895 if (MDLocation *IA = DV.get()->getInlinedAt())
896 Scope = LScopes.findInlinedScope(DV.get()->getScope(), IA);
898 Scope = LScopes.findLexicalScope(DV.get()->getScope());
899 // If variable scope is not found then skip this variable.
903 Processed.insert(DV);
904 const MachineInstr *MInsn = Ranges.front().first;
905 assert(MInsn->isDebugValue() && "History must begin with debug value");
906 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
907 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
908 DbgVariable *RegVar = ConcreteVariables.back().get();
909 InfoHolder.addScopeVariable(Scope, RegVar);
911 // Check if the first DBG_VALUE is valid for the rest of the function.
912 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
915 // Handle multiple DBG_VALUE instructions describing one variable.
916 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
918 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
919 DebugLocList &LocList = DotDebugLocEntries.back();
921 LocList.Label = Asm->createTempSymbol("debug_loc");
923 // Build the location list for this variable.
924 buildLocationList(LocList.List, Ranges);
925 // Finalize the entry by lowering it into a DWARF bytestream.
926 for (auto &Entry : LocList.List)
927 Entry.finalize(*Asm, TypeIdentifierMap);
930 // Collect info for variables that were optimized out.
931 for (DIVariable DV : SP->getVariables()) {
932 if (!Processed.insert(DV).second)
934 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.get()->getScope())) {
935 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
937 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, NoExpr, this));
938 InfoHolder.addScopeVariable(Scope, ConcreteVariables.back().get());
943 // Return Label preceding the instruction.
944 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
945 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
946 assert(Label && "Didn't insert label before instruction");
950 // Return Label immediately following the instruction.
951 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
952 return LabelsAfterInsn.lookup(MI);
955 // Process beginning of an instruction.
956 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
957 assert(CurMI == nullptr);
959 // Check if source location changes, but ignore DBG_VALUE locations.
960 if (!MI->isDebugValue()) {
961 DebugLoc DL = MI->getDebugLoc();
962 if (DL != PrevInstLoc) {
966 if (DL == PrologEndLoc) {
967 Flags |= DWARF2_FLAG_PROLOGUE_END;
968 PrologEndLoc = DebugLoc();
969 Flags |= DWARF2_FLAG_IS_STMT;
972 Asm->OutStreamer.getContext().getCurrentDwarfLoc().getLine())
973 Flags |= DWARF2_FLAG_IS_STMT;
975 const MDNode *Scope = DL.getScope();
976 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
977 } else if (UnknownLocations) {
979 recordSourceLine(0, 0, nullptr, 0);
984 // Insert labels where requested.
985 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
986 LabelsBeforeInsn.find(MI);
989 if (I == LabelsBeforeInsn.end())
992 // Label already assigned.
997 PrevLabel = MMI->getContext().CreateTempSymbol();
998 Asm->OutStreamer.EmitLabel(PrevLabel);
1000 I->second = PrevLabel;
1003 // Process end of an instruction.
1004 void DwarfDebug::endInstruction() {
1005 assert(CurMI != nullptr);
1006 // Don't create a new label after DBG_VALUE instructions.
1007 // They don't generate code.
1008 if (!CurMI->isDebugValue())
1009 PrevLabel = nullptr;
1011 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1012 LabelsAfterInsn.find(CurMI);
1016 if (I == LabelsAfterInsn.end())
1019 // Label already assigned.
1023 // We need a label after this instruction.
1025 PrevLabel = MMI->getContext().CreateTempSymbol();
1026 Asm->OutStreamer.EmitLabel(PrevLabel);
1028 I->second = PrevLabel;
1031 // Each LexicalScope has first instruction and last instruction to mark
1032 // beginning and end of a scope respectively. Create an inverse map that list
1033 // scopes starts (and ends) with an instruction. One instruction may start (or
1034 // end) multiple scopes. Ignore scopes that are not reachable.
1035 void DwarfDebug::identifyScopeMarkers() {
1036 SmallVector<LexicalScope *, 4> WorkList;
1037 WorkList.push_back(LScopes.getCurrentFunctionScope());
1038 while (!WorkList.empty()) {
1039 LexicalScope *S = WorkList.pop_back_val();
1041 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1042 if (!Children.empty())
1043 WorkList.append(Children.begin(), Children.end());
1045 if (S->isAbstractScope())
1048 for (const InsnRange &R : S->getRanges()) {
1049 assert(R.first && "InsnRange does not have first instruction!");
1050 assert(R.second && "InsnRange does not have second instruction!");
1051 requestLabelBeforeInsn(R.first);
1052 requestLabelAfterInsn(R.second);
1057 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1058 // First known non-DBG_VALUE and non-frame setup location marks
1059 // the beginning of the function body.
1060 for (const auto &MBB : *MF)
1061 for (const auto &MI : MBB)
1062 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1064 // Did the target forget to set the FrameSetup flag for CFI insns?
1065 assert(!MI.isCFIInstruction() &&
1066 "First non-frame-setup instruction is a CFI instruction.");
1067 return MI.getDebugLoc();
1072 // Gather pre-function debug information. Assumes being called immediately
1073 // after the function entry point has been emitted.
1074 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1077 // If there's no debug info for the function we're not going to do anything.
1078 if (!MMI->hasDebugInfo())
1081 auto DI = FunctionDIs.find(MF->getFunction());
1082 if (DI == FunctionDIs.end())
1085 // Grab the lexical scopes for the function, if we don't have any of those
1086 // then we're not going to be able to do anything.
1087 LScopes.initialize(*MF);
1088 if (LScopes.empty())
1091 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1093 // Make sure that each lexical scope will have a begin/end label.
1094 identifyScopeMarkers();
1096 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1097 // belongs to so that we add to the correct per-cu line table in the
1099 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1100 // FnScope->getScopeNode() and DI->second should represent the same function,
1101 // though they may not be the same MDNode due to inline functions merged in
1102 // LTO where the debug info metadata still differs (either due to distinct
1103 // written differences - two versions of a linkonce_odr function
1104 // written/copied into two separate files, or some sub-optimal metadata that
1105 // isn't structurally identical (see: file path/name info from clang, which
1106 // includes the directory of the cpp file being built, even when the file name
1107 // is absolute (such as an <> lookup header)))
1108 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1109 assert(TheCU && "Unable to find compile unit!");
1110 if (Asm->OutStreamer.hasRawTextSupport())
1111 // Use a single line table if we are generating assembly.
1112 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1114 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1116 // Calculate history for local variables.
1117 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1120 // Request labels for the full history.
1121 for (const auto &I : DbgValues) {
1122 const auto &Ranges = I.second;
1126 // The first mention of a function argument gets the CurrentFnBegin
1127 // label, so arguments are visible when breaking at function entry.
1128 DIVariable DIVar = Ranges.front().first->getDebugVariable();
1129 if (DIVar.getTag() == dwarf::DW_TAG_arg_variable &&
1130 getDISubprogram(DIVar.getContext()).describes(MF->getFunction())) {
1131 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1132 if (Ranges.front().first->getDebugExpression()->isBitPiece()) {
1133 // Mark all non-overlapping initial pieces.
1134 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1135 DIExpression Piece = I->first->getDebugExpression();
1136 if (std::all_of(Ranges.begin(), I,
1137 [&](DbgValueHistoryMap::InstrRange Pred) {
1138 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1140 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1147 for (const auto &Range : Ranges) {
1148 requestLabelBeforeInsn(Range.first);
1150 requestLabelAfterInsn(Range.second);
1154 PrevInstLoc = DebugLoc();
1155 PrevLabel = Asm->getFunctionBegin();
1157 // Record beginning of function.
1158 PrologEndLoc = findPrologueEndLoc(MF);
1159 if (MDLocation *L = PrologEndLoc) {
1160 // We'd like to list the prologue as "not statements" but GDB behaves
1161 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1162 auto *SP = L->getInlinedAtScope()->getSubprogram();
1163 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1167 // Gather and emit post-function debug information.
1168 void DwarfDebug::endFunction(const MachineFunction *MF) {
1169 assert(CurFn == MF &&
1170 "endFunction should be called with the same function as beginFunction");
1172 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1173 !FunctionDIs.count(MF->getFunction())) {
1174 // If we don't have a lexical scope for this function then there will
1175 // be a hole in the range information. Keep note of this by setting the
1176 // previously used section to nullptr.
1182 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1183 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1185 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1186 DISubprogram SP = cast<MDSubprogram>(FnScope->getScopeNode());
1187 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1189 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1190 collectVariableInfo(TheCU, SP, ProcessedVars);
1192 // Add the range of this function to the list of ranges for the CU.
1193 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1195 // Under -gmlt, skip building the subprogram if there are no inlined
1196 // subroutines inside it.
1197 if (TheCU.getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly &&
1198 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1199 assert(InfoHolder.getScopeVariables().empty());
1200 assert(DbgValues.empty());
1201 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1202 // by a -gmlt CU. Add a test and remove this assertion.
1203 assert(AbstractVariables.empty());
1204 LabelsBeforeInsn.clear();
1205 LabelsAfterInsn.clear();
1206 PrevLabel = nullptr;
1212 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1214 // Construct abstract scopes.
1215 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1216 DISubprogram SP = cast<MDSubprogram>(AScope->getScopeNode());
1217 // Collect info for variables that were optimized out.
1218 for (DIVariable DV : SP->getVariables()) {
1219 if (!ProcessedVars.insert(DV).second)
1221 ensureAbstractVariableIsCreated(DV, DV.getContext());
1222 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1223 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1225 constructAbstractSubprogramScopeDIE(AScope);
1228 TheCU.constructSubprogramScopeDIE(FnScope);
1229 if (auto *SkelCU = TheCU.getSkeleton())
1230 if (!LScopes.getAbstractScopesList().empty())
1231 SkelCU->constructSubprogramScopeDIE(FnScope);
1234 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1235 // DbgVariables except those that are also in AbstractVariables (since they
1236 // can be used cross-function)
1237 InfoHolder.getScopeVariables().clear();
1239 LabelsBeforeInsn.clear();
1240 LabelsAfterInsn.clear();
1241 PrevLabel = nullptr;
1245 // Register a source line with debug info. Returns the unique label that was
1246 // emitted and which provides correspondence to the source line list.
1247 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1252 unsigned Discriminator = 0;
1253 if (DIScope Scope = cast_or_null<MDScope>(S)) {
1254 Fn = Scope.getFilename();
1255 Dir = Scope.getDirectory();
1256 if (DILexicalBlockFile LBF = dyn_cast<MDLexicalBlockFile>(Scope))
1257 Discriminator = LBF.getDiscriminator();
1259 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1260 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1261 .getOrCreateSourceID(Fn, Dir);
1263 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1267 //===----------------------------------------------------------------------===//
1269 //===----------------------------------------------------------------------===//
1271 // Emit the debug info section.
1272 void DwarfDebug::emitDebugInfo() {
1273 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1274 Holder.emitUnits(/* UseOffsets */ false);
1277 // Emit the abbreviation section.
1278 void DwarfDebug::emitAbbreviations() {
1279 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1281 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1284 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1285 StringRef TableName) {
1286 Accel.FinalizeTable(Asm, TableName);
1287 Asm->OutStreamer.SwitchSection(Section);
1289 // Emit the full data.
1290 Accel.emit(Asm, Section->getBeginSymbol(), this);
1293 // Emit visible names into a hashed accelerator table section.
1294 void DwarfDebug::emitAccelNames() {
1295 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1299 // Emit objective C classes and categories into a hashed accelerator table
1301 void DwarfDebug::emitAccelObjC() {
1302 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1306 // Emit namespace dies into a hashed accelerator table.
1307 void DwarfDebug::emitAccelNamespaces() {
1308 emitAccel(AccelNamespace,
1309 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1313 // Emit type dies into a hashed accelerator table.
1314 void DwarfDebug::emitAccelTypes() {
1315 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1319 // Public name handling.
1320 // The format for the various pubnames:
1322 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1323 // for the DIE that is named.
1325 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1326 // into the CU and the index value is computed according to the type of value
1327 // for the DIE that is named.
1329 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1330 // it's the offset within the debug_info/debug_types dwo section, however, the
1331 // reference in the pubname header doesn't change.
1333 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1334 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1336 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1338 // We could have a specification DIE that has our most of our knowledge,
1339 // look for that now.
1340 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1342 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1343 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1344 Linkage = dwarf::GIEL_EXTERNAL;
1345 } else if (Die->findAttribute(dwarf::DW_AT_external))
1346 Linkage = dwarf::GIEL_EXTERNAL;
1348 switch (Die->getTag()) {
1349 case dwarf::DW_TAG_class_type:
1350 case dwarf::DW_TAG_structure_type:
1351 case dwarf::DW_TAG_union_type:
1352 case dwarf::DW_TAG_enumeration_type:
1353 return dwarf::PubIndexEntryDescriptor(
1354 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1355 ? dwarf::GIEL_STATIC
1356 : dwarf::GIEL_EXTERNAL);
1357 case dwarf::DW_TAG_typedef:
1358 case dwarf::DW_TAG_base_type:
1359 case dwarf::DW_TAG_subrange_type:
1360 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1361 case dwarf::DW_TAG_namespace:
1362 return dwarf::GIEK_TYPE;
1363 case dwarf::DW_TAG_subprogram:
1364 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1365 case dwarf::DW_TAG_variable:
1366 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1367 case dwarf::DW_TAG_enumerator:
1368 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1369 dwarf::GIEL_STATIC);
1371 return dwarf::GIEK_NONE;
1375 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1377 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1378 const MCSection *PSec =
1379 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1380 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1382 emitDebugPubSection(GnuStyle, PSec, "Names",
1383 &DwarfCompileUnit::getGlobalNames);
1386 void DwarfDebug::emitDebugPubSection(
1387 bool GnuStyle, const MCSection *PSec, StringRef Name,
1388 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1389 for (const auto &NU : CUMap) {
1390 DwarfCompileUnit *TheU = NU.second;
1392 const auto &Globals = (TheU->*Accessor)();
1394 if (Globals.empty())
1397 if (auto *Skeleton = TheU->getSkeleton())
1400 // Start the dwarf pubnames section.
1401 Asm->OutStreamer.SwitchSection(PSec);
1404 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1405 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1406 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1407 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1409 Asm->OutStreamer.EmitLabel(BeginLabel);
1411 Asm->OutStreamer.AddComment("DWARF Version");
1412 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1414 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1415 Asm->emitSectionOffset(TheU->getLabelBegin());
1417 Asm->OutStreamer.AddComment("Compilation Unit Length");
1418 Asm->EmitInt32(TheU->getLength());
1420 // Emit the pubnames for this compilation unit.
1421 for (const auto &GI : Globals) {
1422 const char *Name = GI.getKeyData();
1423 const DIE *Entity = GI.second;
1425 Asm->OutStreamer.AddComment("DIE offset");
1426 Asm->EmitInt32(Entity->getOffset());
1429 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1430 Asm->OutStreamer.AddComment(
1431 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1432 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1433 Asm->EmitInt8(Desc.toBits());
1436 Asm->OutStreamer.AddComment("External Name");
1437 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1440 Asm->OutStreamer.AddComment("End Mark");
1442 Asm->OutStreamer.EmitLabel(EndLabel);
1446 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1447 const MCSection *PSec =
1448 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1449 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1451 emitDebugPubSection(GnuStyle, PSec, "Types",
1452 &DwarfCompileUnit::getGlobalTypes);
1455 // Emit visible names into a debug str section.
1456 void DwarfDebug::emitDebugStr() {
1457 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1458 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1462 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1463 const DebugLocEntry &Entry) {
1464 auto Comment = Entry.getComments().begin();
1465 auto End = Entry.getComments().end();
1466 for (uint8_t Byte : Entry.getDWARFBytes())
1467 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1470 static void emitDebugLocValue(const AsmPrinter &AP,
1471 const DITypeIdentifierMap &TypeIdentifierMap,
1472 ByteStreamer &Streamer,
1473 const DebugLocEntry::Value &Value,
1474 unsigned PieceOffsetInBits) {
1475 DIVariable DV = Value.getVariable();
1476 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1477 AP.getDwarfDebug()->getDwarfVersion(),
1480 if (Value.isInt()) {
1481 MDType *T = DV.getType().resolve(TypeIdentifierMap);
1482 auto *B = dyn_cast<MDBasicType>(T);
1483 if (B && (B->getEncoding() == dwarf::DW_ATE_signed ||
1484 B->getEncoding() == dwarf::DW_ATE_signed_char))
1485 DwarfExpr.AddSignedConstant(Value.getInt());
1487 DwarfExpr.AddUnsignedConstant(Value.getInt());
1488 } else if (Value.isLocation()) {
1489 MachineLocation Loc = Value.getLoc();
1490 DIExpression Expr = Value.getExpression();
1491 if (!Expr || !Expr->getNumElements())
1493 AP.EmitDwarfRegOp(Streamer, Loc);
1495 // Complex address entry.
1496 if (Loc.getOffset()) {
1497 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1498 DwarfExpr.AddExpression(Expr->expr_op_begin(), Expr->expr_op_end(),
1501 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1505 // else ... ignore constant fp. There is not any good way to
1506 // to represent them here in dwarf.
1511 void DebugLocEntry::finalize(const AsmPrinter &AP,
1512 const DITypeIdentifierMap &TypeIdentifierMap) {
1513 BufferByteStreamer Streamer(DWARFBytes, Comments);
1514 const DebugLocEntry::Value Value = Values[0];
1515 if (Value.isBitPiece()) {
1516 // Emit all pieces that belong to the same variable and range.
1517 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1518 return P.isBitPiece();
1519 }) && "all values are expected to be pieces");
1520 assert(std::is_sorted(Values.begin(), Values.end()) &&
1521 "pieces are expected to be sorted");
1523 unsigned Offset = 0;
1524 for (auto Piece : Values) {
1525 DIExpression Expr = Piece.getExpression();
1526 unsigned PieceOffset = Expr->getBitPieceOffset();
1527 unsigned PieceSize = Expr->getBitPieceSize();
1528 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1529 if (Offset < PieceOffset) {
1530 // The DWARF spec seriously mandates pieces with no locations for gaps.
1531 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1532 AP.getDwarfDebug()->getDwarfVersion(),
1534 Expr.AddOpPiece(PieceOffset-Offset, 0);
1535 Offset += PieceOffset-Offset;
1537 Offset += PieceSize;
1539 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Piece, PieceOffset);
1542 assert(Values.size() == 1 && "only pieces may have >1 value");
1543 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Value, 0);
1548 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
1549 Asm->OutStreamer.AddComment("Loc expr size");
1550 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
1551 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
1552 Asm->EmitLabelDifference(end, begin, 2);
1553 Asm->OutStreamer.EmitLabel(begin);
1555 APByteStreamer Streamer(*Asm);
1556 emitDebugLocEntry(Streamer, Entry);
1558 Asm->OutStreamer.EmitLabel(end);
1561 // Emit locations into the debug loc section.
1562 void DwarfDebug::emitDebugLoc() {
1563 // Start the dwarf loc section.
1564 Asm->OutStreamer.SwitchSection(
1565 Asm->getObjFileLowering().getDwarfLocSection());
1566 unsigned char Size = Asm->getDataLayout().getPointerSize();
1567 for (const auto &DebugLoc : DotDebugLocEntries) {
1568 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1569 const DwarfCompileUnit *CU = DebugLoc.CU;
1570 for (const auto &Entry : DebugLoc.List) {
1571 // Set up the range. This range is relative to the entry point of the
1572 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1573 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1574 if (auto *Base = CU->getBaseAddress()) {
1575 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
1576 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
1578 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
1579 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
1582 emitDebugLocEntryLocation(Entry);
1584 Asm->OutStreamer.EmitIntValue(0, Size);
1585 Asm->OutStreamer.EmitIntValue(0, Size);
1589 void DwarfDebug::emitDebugLocDWO() {
1590 Asm->OutStreamer.SwitchSection(
1591 Asm->getObjFileLowering().getDwarfLocDWOSection());
1592 for (const auto &DebugLoc : DotDebugLocEntries) {
1593 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1594 for (const auto &Entry : DebugLoc.List) {
1595 // Just always use start_length for now - at least that's one address
1596 // rather than two. We could get fancier and try to, say, reuse an
1597 // address we know we've emitted elsewhere (the start of the function?
1598 // The start of the CU or CU subrange that encloses this range?)
1599 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1600 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
1601 Asm->EmitULEB128(idx);
1602 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
1604 emitDebugLocEntryLocation(Entry);
1606 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1611 const MCSymbol *Start, *End;
1614 // Emit a debug aranges section, containing a CU lookup for any
1615 // address we can tie back to a CU.
1616 void DwarfDebug::emitDebugARanges() {
1617 // Provides a unique id per text section.
1618 MapVector<const MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1620 // Filter labels by section.
1621 for (const SymbolCU &SCU : ArangeLabels) {
1622 if (SCU.Sym->isInSection()) {
1623 // Make a note of this symbol and it's section.
1624 const MCSection *Section = &SCU.Sym->getSection();
1625 if (!Section->getKind().isMetadata())
1626 SectionMap[Section].push_back(SCU);
1628 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1629 // appear in the output. This sucks as we rely on sections to build
1630 // arange spans. We can do it without, but it's icky.
1631 SectionMap[nullptr].push_back(SCU);
1635 // Add terminating symbols for each section.
1636 for (const auto &I : SectionMap) {
1637 const MCSection *Section = I.first;
1638 MCSymbol *Sym = nullptr;
1641 Sym = Asm->OutStreamer.endSection(Section);
1643 // Insert a final terminator.
1644 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1647 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1649 for (auto &I : SectionMap) {
1650 const MCSection *Section = I.first;
1651 SmallVector<SymbolCU, 8> &List = I.second;
1652 if (List.size() < 2)
1655 // If we have no section (e.g. common), just write out
1656 // individual spans for each symbol.
1658 for (const SymbolCU &Cur : List) {
1660 Span.Start = Cur.Sym;
1663 Spans[Cur.CU].push_back(Span);
1668 // Sort the symbols by offset within the section.
1669 std::sort(List.begin(), List.end(),
1670 [&](const SymbolCU &A, const SymbolCU &B) {
1671 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
1672 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
1674 // Symbols with no order assigned should be placed at the end.
1675 // (e.g. section end labels)
1683 // Build spans between each label.
1684 const MCSymbol *StartSym = List[0].Sym;
1685 for (size_t n = 1, e = List.size(); n < e; n++) {
1686 const SymbolCU &Prev = List[n - 1];
1687 const SymbolCU &Cur = List[n];
1689 // Try and build the longest span we can within the same CU.
1690 if (Cur.CU != Prev.CU) {
1692 Span.Start = StartSym;
1694 Spans[Prev.CU].push_back(Span);
1700 // Start the dwarf aranges section.
1701 Asm->OutStreamer.SwitchSection(
1702 Asm->getObjFileLowering().getDwarfARangesSection());
1704 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1706 // Build a list of CUs used.
1707 std::vector<DwarfCompileUnit *> CUs;
1708 for (const auto &it : Spans) {
1709 DwarfCompileUnit *CU = it.first;
1713 // Sort the CU list (again, to ensure consistent output order).
1714 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1715 return A->getUniqueID() < B->getUniqueID();
1718 // Emit an arange table for each CU we used.
1719 for (DwarfCompileUnit *CU : CUs) {
1720 std::vector<ArangeSpan> &List = Spans[CU];
1722 // Describe the skeleton CU's offset and length, not the dwo file's.
1723 if (auto *Skel = CU->getSkeleton())
1726 // Emit size of content not including length itself.
1727 unsigned ContentSize =
1728 sizeof(int16_t) + // DWARF ARange version number
1729 sizeof(int32_t) + // Offset of CU in the .debug_info section
1730 sizeof(int8_t) + // Pointer Size (in bytes)
1731 sizeof(int8_t); // Segment Size (in bytes)
1733 unsigned TupleSize = PtrSize * 2;
1735 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1737 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1739 ContentSize += Padding;
1740 ContentSize += (List.size() + 1) * TupleSize;
1742 // For each compile unit, write the list of spans it covers.
1743 Asm->OutStreamer.AddComment("Length of ARange Set");
1744 Asm->EmitInt32(ContentSize);
1745 Asm->OutStreamer.AddComment("DWARF Arange version number");
1746 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1747 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
1748 Asm->emitSectionOffset(CU->getLabelBegin());
1749 Asm->OutStreamer.AddComment("Address Size (in bytes)");
1750 Asm->EmitInt8(PtrSize);
1751 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
1754 Asm->OutStreamer.EmitFill(Padding, 0xff);
1756 for (const ArangeSpan &Span : List) {
1757 Asm->EmitLabelReference(Span.Start, PtrSize);
1759 // Calculate the size as being from the span start to it's end.
1761 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1763 // For symbols without an end marker (e.g. common), we
1764 // write a single arange entry containing just that one symbol.
1765 uint64_t Size = SymSize[Span.Start];
1769 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
1773 Asm->OutStreamer.AddComment("ARange terminator");
1774 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1775 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1779 // Emit visible names into a debug ranges section.
1780 void DwarfDebug::emitDebugRanges() {
1781 // Start the dwarf ranges section.
1782 Asm->OutStreamer.SwitchSection(
1783 Asm->getObjFileLowering().getDwarfRangesSection());
1785 // Size for our labels.
1786 unsigned char Size = Asm->getDataLayout().getPointerSize();
1788 // Grab the specific ranges for the compile units in the module.
1789 for (const auto &I : CUMap) {
1790 DwarfCompileUnit *TheCU = I.second;
1792 if (auto *Skel = TheCU->getSkeleton())
1795 // Iterate over the misc ranges for the compile units in the module.
1796 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1797 // Emit our symbol so we can find the beginning of the range.
1798 Asm->OutStreamer.EmitLabel(List.getSym());
1800 for (const RangeSpan &Range : List.getRanges()) {
1801 const MCSymbol *Begin = Range.getStart();
1802 const MCSymbol *End = Range.getEnd();
1803 assert(Begin && "Range without a begin symbol?");
1804 assert(End && "Range without an end symbol?");
1805 if (auto *Base = TheCU->getBaseAddress()) {
1806 Asm->EmitLabelDifference(Begin, Base, Size);
1807 Asm->EmitLabelDifference(End, Base, Size);
1809 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
1810 Asm->OutStreamer.EmitSymbolValue(End, Size);
1814 // And terminate the list with two 0 values.
1815 Asm->OutStreamer.EmitIntValue(0, Size);
1816 Asm->OutStreamer.EmitIntValue(0, Size);
1821 // DWARF5 Experimental Separate Dwarf emitters.
1823 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1824 std::unique_ptr<DwarfUnit> NewU) {
1825 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1826 U.getCUNode().getSplitDebugFilename());
1828 if (!CompilationDir.empty())
1829 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1831 addGnuPubAttributes(*NewU, Die);
1833 SkeletonHolder.addUnit(std::move(NewU));
1836 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1837 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1838 // DW_AT_addr_base, DW_AT_ranges_base.
1839 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1841 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1842 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1843 DwarfCompileUnit &NewCU = *OwnedUnit;
1844 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1846 NewCU.initStmtList();
1848 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1853 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1854 // compile units that would normally be in debug_info.
1855 void DwarfDebug::emitDebugInfoDWO() {
1856 assert(useSplitDwarf() && "No split dwarf debug info?");
1857 // Don't emit relocations into the dwo file.
1858 InfoHolder.emitUnits(/* UseOffsets */ true);
1861 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1862 // abbreviations for the .debug_info.dwo section.
1863 void DwarfDebug::emitDebugAbbrevDWO() {
1864 assert(useSplitDwarf() && "No split dwarf?");
1865 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1868 void DwarfDebug::emitDebugLineDWO() {
1869 assert(useSplitDwarf() && "No split dwarf?");
1870 Asm->OutStreamer.SwitchSection(
1871 Asm->getObjFileLowering().getDwarfLineDWOSection());
1872 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
1875 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1876 // string section and is identical in format to traditional .debug_str
1878 void DwarfDebug::emitDebugStrDWO() {
1879 assert(useSplitDwarf() && "No split dwarf?");
1880 const MCSection *OffSec =
1881 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1882 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1886 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1887 if (!useSplitDwarf())
1890 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
1891 return &SplitTypeUnitFileTable;
1894 static uint64_t makeTypeSignature(StringRef Identifier) {
1896 Hash.update(Identifier);
1897 // ... take the least significant 8 bytes and return those. Our MD5
1898 // implementation always returns its results in little endian, swap bytes
1900 MD5::MD5Result Result;
1902 return support::endian::read64le(Result + 8);
1905 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1906 StringRef Identifier, DIE &RefDie,
1907 DICompositeType CTy) {
1908 // Fast path if we're building some type units and one has already used the
1909 // address pool we know we're going to throw away all this work anyway, so
1910 // don't bother building dependent types.
1911 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1914 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1916 CU.addDIETypeSignature(RefDie, *TU);
1920 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1921 AddrPool.resetUsedFlag();
1923 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1924 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1925 this, &InfoHolder, getDwoLineTable(CU));
1926 DwarfTypeUnit &NewTU = *OwnedUnit;
1927 DIE &UnitDie = NewTU.getUnitDie();
1929 TypeUnitsUnderConstruction.push_back(
1930 std::make_pair(std::move(OwnedUnit), CTy));
1932 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1935 uint64_t Signature = makeTypeSignature(Identifier);
1936 NewTU.setTypeSignature(Signature);
1938 if (useSplitDwarf())
1939 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1941 CU.applyStmtList(UnitDie);
1943 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1946 NewTU.setType(NewTU.createTypeDIE(CTy));
1949 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1950 TypeUnitsUnderConstruction.clear();
1952 // Types referencing entries in the address table cannot be placed in type
1954 if (AddrPool.hasBeenUsed()) {
1956 // Remove all the types built while building this type.
1957 // This is pessimistic as some of these types might not be dependent on
1958 // the type that used an address.
1959 for (const auto &TU : TypeUnitsToAdd)
1960 DwarfTypeUnits.erase(TU.second);
1962 // Construct this type in the CU directly.
1963 // This is inefficient because all the dependent types will be rebuilt
1964 // from scratch, including building them in type units, discovering that
1965 // they depend on addresses, throwing them out and rebuilding them.
1966 CU.constructTypeDIE(RefDie, CTy);
1970 // If the type wasn't dependent on fission addresses, finish adding the type
1971 // and all its dependent types.
1972 for (auto &TU : TypeUnitsToAdd)
1973 InfoHolder.addUnit(std::move(TU.first));
1975 CU.addDIETypeSignature(RefDie, NewTU);
1978 // Accelerator table mutators - add each name along with its companion
1979 // DIE to the proper table while ensuring that the name that we're going
1980 // to reference is in the string table. We do this since the names we
1981 // add may not only be identical to the names in the DIE.
1982 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
1983 if (!useDwarfAccelTables())
1985 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
1989 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
1990 if (!useDwarfAccelTables())
1992 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
1996 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
1997 if (!useDwarfAccelTables())
1999 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2003 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2004 if (!useDwarfAccelTables())
2006 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),