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 ScopesWithLocalDeclNodes.push_back(std::make_pair(IE->getScope(), IE));
453 for (auto *GV : CUNode->getGlobalVariables()) {
454 auto *Context = GV->getScope();
455 if (Context && isa<DILexicalBlockBase>(Context))
456 ScopesWithLocalDeclNodes.push_back(std::make_pair(Context, GV));
458 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 DIType *RT = cast<DIType>(resolve(Ty->getRef()));
471 auto *Context = resolve(Ty->getScope());
472 if (Context && isa<DILexicalBlockBase>(Context))
473 ScopesWithLocalDeclNodes.push_back(std::make_pair(Context, RT));
475 CU.getOrCreateTypeDIE(RT);
477 // Emit imported_modules last so that the relevant context is already
479 for (auto *IE : CUNode->getImportedEntities())
480 constructAndAddImportedEntityDIE(CU, IE);
482 // Stable sort to preserve the order of appearance of imported entities.
483 // This is to avoid out-of-order processing of interdependent declarations
484 // within the same scope, e.g. { namespace A = base; namespace B = A; }
485 std::stable_sort(ScopesWithLocalDeclNodes.begin(),
486 ScopesWithLocalDeclNodes.end(), less_first());
489 // Tell MMI that we have debug info.
490 MMI->setDebugInfoAvailability(true);
493 void DwarfDebug::finishVariableDefinitions() {
494 for (const auto &Var : ConcreteVariables) {
495 DIE *VariableDie = Var->getDIE();
497 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
498 // in the ConcreteVariables list, rather than looking it up again here.
499 // DIE::getUnit isn't simple - it walks parent pointers, etc.
500 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
502 DbgVariable *AbsVar = getExistingAbstractVariable(
503 InlinedVariable(Var->getVariable(), Var->getInlinedAt()));
504 if (AbsVar && AbsVar->getDIE()) {
505 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
508 Unit->applyVariableAttributes(*Var, *VariableDie);
512 void DwarfDebug::finishSubprogramDefinitions() {
513 for (const auto &P : SPMap)
514 forBothCUs(*P.second, [&](DwarfCompileUnit &CU) {
515 CU.finishSubprogramDefinition(cast<DISubprogram>(P.first));
520 // Collect info for variables that were optimized out.
521 void DwarfDebug::collectDeadVariables() {
522 const Module *M = MMI->getModule();
524 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
525 for (MDNode *N : CU_Nodes->operands()) {
526 auto *TheCU = cast<DICompileUnit>(N);
527 // Construct subprogram DIE and add variables DIEs.
528 DwarfCompileUnit *SPCU =
529 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
530 assert(SPCU && "Unable to find Compile Unit!");
531 for (auto *SP : TheCU->getSubprograms()) {
532 if (ProcessedSPNodes.count(SP) != 0)
534 SPCU->collectDeadVariables(SP);
540 void DwarfDebug::finalizeModuleInfo() {
541 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
543 finishSubprogramDefinitions();
545 finishVariableDefinitions();
547 // Collect info for variables that were optimized out.
548 collectDeadVariables();
550 // Handle anything that needs to be done on a per-unit basis after
551 // all other generation.
552 for (const auto &P : CUMap) {
553 auto &TheCU = *P.second;
554 // Emit DW_AT_containing_type attribute to connect types with their
555 // vtable holding type.
556 TheCU.constructContainingTypeDIEs();
558 // Add CU specific attributes if we need to add any.
559 // If we're splitting the dwarf out now that we've got the entire
560 // CU then add the dwo id to it.
561 auto *SkCU = TheCU.getSkeleton();
562 if (useSplitDwarf()) {
563 // Emit a unique identifier for this CU.
564 uint64_t ID = DIEHash(Asm).computeCUSignature(TheCU.getUnitDie());
565 TheCU.addUInt(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
566 dwarf::DW_FORM_data8, ID);
567 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
568 dwarf::DW_FORM_data8, ID);
570 // We don't keep track of which addresses are used in which CU so this
571 // is a bit pessimistic under LTO.
572 if (!AddrPool.isEmpty()) {
573 const MCSymbol *Sym = TLOF.getDwarfAddrSection()->getBeginSymbol();
574 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_addr_base,
577 if (!SkCU->getRangeLists().empty()) {
578 const MCSymbol *Sym = TLOF.getDwarfRangesSection()->getBeginSymbol();
579 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
584 // If we have code split among multiple sections or non-contiguous
585 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
586 // remain in the .o file, otherwise add a DW_AT_low_pc.
587 // FIXME: We should use ranges allow reordering of code ala
588 // .subsections_via_symbols in mach-o. This would mean turning on
589 // ranges for all subprogram DIEs for mach-o.
590 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
591 if (unsigned NumRanges = TheCU.getRanges().size()) {
593 // A DW_AT_low_pc attribute may also be specified in combination with
594 // DW_AT_ranges to specify the default base address for use in
595 // location lists (see Section 2.6.2) and range lists (see Section
597 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
599 U.setBaseAddress(TheCU.getRanges().front().getStart());
600 U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
604 // Compute DIE offsets and sizes.
605 InfoHolder.computeSizeAndOffsets();
607 SkeletonHolder.computeSizeAndOffsets();
610 // Emit all Dwarf sections that should come after the content.
611 void DwarfDebug::endModule() {
612 assert(CurFn == nullptr);
613 assert(CurMI == nullptr);
615 // If we aren't actually generating debug info (check beginModule -
616 // conditionalized on !DisableDebugInfoPrinting and the presence of the
617 // llvm.dbg.cu metadata node)
618 if (!MMI->hasDebugInfo())
621 // Finalize the debug info for the module.
622 finalizeModuleInfo();
629 // Emit info into a debug loc section.
632 // Corresponding abbreviations into a abbrev section.
635 // Emit all the DIEs into a debug info section.
638 // Emit info into a debug aranges section.
639 if (GenerateARangeSection)
642 // Emit info into a debug ranges section.
645 if (useSplitDwarf()) {
648 emitDebugAbbrevDWO();
650 // Emit DWO addresses.
651 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
654 // Emit info into the dwarf accelerator table sections.
655 if (useDwarfAccelTables()) {
658 emitAccelNamespaces();
662 // Emit the pubnames and pubtypes sections if requested.
663 if (HasDwarfPubSections) {
664 emitDebugPubNames(GenerateGnuPubSections);
665 emitDebugPubTypes(GenerateGnuPubSections);
670 AbstractVariables.clear();
673 // Find abstract variable, if any, associated with Var.
675 DwarfDebug::getExistingAbstractVariable(InlinedVariable IV,
676 const DILocalVariable *&Cleansed) {
677 // More then one inlined variable corresponds to one abstract variable.
679 auto I = AbstractVariables.find(Cleansed);
680 if (I != AbstractVariables.end())
681 return I->second.get();
685 DbgVariable *DwarfDebug::getExistingAbstractVariable(InlinedVariable IV) {
686 const DILocalVariable *Cleansed;
687 return getExistingAbstractVariable(IV, Cleansed);
690 void DwarfDebug::createAbstractVariable(const DILocalVariable *Var,
691 LexicalScope *Scope) {
692 auto AbsDbgVariable = make_unique<DbgVariable>(Var, /* IA */ nullptr, this);
693 InfoHolder.addScopeVariable(Scope, AbsDbgVariable.get());
694 AbstractVariables[Var] = std::move(AbsDbgVariable);
697 void DwarfDebug::ensureAbstractVariableIsCreated(InlinedVariable IV,
698 const MDNode *ScopeNode) {
699 const DILocalVariable *Cleansed = nullptr;
700 if (getExistingAbstractVariable(IV, Cleansed))
703 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(
704 cast<DILocalScope>(ScopeNode)));
707 void DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(
708 InlinedVariable IV, const MDNode *ScopeNode) {
709 const DILocalVariable *Cleansed = nullptr;
710 if (getExistingAbstractVariable(IV, Cleansed))
713 if (LexicalScope *Scope =
714 LScopes.findAbstractScope(cast_or_null<DILocalScope>(ScopeNode)))
715 createAbstractVariable(Cleansed, Scope);
718 // Collect variable information from side table maintained by MMI.
719 void DwarfDebug::collectVariableInfoFromMMITable(
720 DenseSet<InlinedVariable> &Processed) {
721 for (const auto &VI : MMI->getVariableDbgInfo()) {
724 assert(VI.Var->isValidLocationForIntrinsic(VI.Loc) &&
725 "Expected inlined-at fields to agree");
727 InlinedVariable Var(VI.Var, VI.Loc->getInlinedAt());
728 Processed.insert(Var);
729 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
731 // If variable scope is not found then skip this variable.
735 ensureAbstractVariableIsCreatedIfScoped(Var, Scope->getScopeNode());
736 auto RegVar = make_unique<DbgVariable>(Var.first, Var.second, this);
737 RegVar->initializeMMI(VI.Expr, VI.Slot);
738 if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
739 ConcreteVariables.push_back(std::move(RegVar));
743 // Get .debug_loc entry for the instruction range starting at MI.
744 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
745 const DIExpression *Expr = MI->getDebugExpression();
747 assert(MI->getNumOperands() == 4);
748 if (MI->getOperand(0).isReg()) {
749 MachineLocation MLoc;
750 // If the second operand is an immediate, this is a
751 // register-indirect address.
752 if (!MI->getOperand(1).isImm())
753 MLoc.set(MI->getOperand(0).getReg());
755 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
756 return DebugLocEntry::Value(Expr, MLoc);
758 if (MI->getOperand(0).isImm())
759 return DebugLocEntry::Value(Expr, MI->getOperand(0).getImm());
760 if (MI->getOperand(0).isFPImm())
761 return DebugLocEntry::Value(Expr, MI->getOperand(0).getFPImm());
762 if (MI->getOperand(0).isCImm())
763 return DebugLocEntry::Value(Expr, MI->getOperand(0).getCImm());
765 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
768 /// Determine whether two variable pieces overlap.
769 static bool piecesOverlap(const DIExpression *P1, const DIExpression *P2) {
770 if (!P1->isBitPiece() || !P2->isBitPiece())
772 unsigned l1 = P1->getBitPieceOffset();
773 unsigned l2 = P2->getBitPieceOffset();
774 unsigned r1 = l1 + P1->getBitPieceSize();
775 unsigned r2 = l2 + P2->getBitPieceSize();
776 // True where [l1,r1[ and [r1,r2[ overlap.
777 return (l1 < r2) && (l2 < r1);
780 /// Build the location list for all DBG_VALUEs in the function that
781 /// describe the same variable. If the ranges of several independent
782 /// pieces of the same variable overlap partially, split them up and
783 /// combine the ranges. The resulting DebugLocEntries are will have
784 /// strict monotonically increasing begin addresses and will never
789 // Ranges History [var, loc, piece ofs size]
790 // 0 | [x, (reg0, piece 0, 32)]
791 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
793 // 3 | [clobber reg0]
794 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of
799 // [0-1] [x, (reg0, piece 0, 32)]
800 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
801 // [3-4] [x, (reg1, piece 32, 32)]
802 // [4- ] [x, (mem, piece 0, 64)]
804 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
805 const DbgValueHistoryMap::InstrRanges &Ranges) {
806 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
808 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
809 const MachineInstr *Begin = I->first;
810 const MachineInstr *End = I->second;
811 assert(Begin->isDebugValue() && "Invalid History entry");
813 // Check if a variable is inaccessible in this range.
814 if (Begin->getNumOperands() > 1 &&
815 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
820 // If this piece overlaps with any open ranges, truncate them.
821 const DIExpression *DIExpr = Begin->getDebugExpression();
822 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
823 [&](DebugLocEntry::Value R) {
824 return piecesOverlap(DIExpr, R.getExpression());
826 OpenRanges.erase(Last, OpenRanges.end());
828 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
829 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
831 const MCSymbol *EndLabel;
833 EndLabel = getLabelAfterInsn(End);
834 else if (std::next(I) == Ranges.end())
835 EndLabel = Asm->getFunctionEnd();
837 EndLabel = getLabelBeforeInsn(std::next(I)->first);
838 assert(EndLabel && "Forgot label after instruction ending a range!");
840 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
842 auto Value = getDebugLocValue(Begin);
843 DebugLocEntry Loc(StartLabel, EndLabel, Value);
844 bool couldMerge = false;
846 // If this is a piece, it may belong to the current DebugLocEntry.
847 if (DIExpr->isBitPiece()) {
848 // Add this value to the list of open ranges.
849 OpenRanges.push_back(Value);
851 // Attempt to add the piece to the last entry.
852 if (!DebugLoc.empty())
853 if (DebugLoc.back().MergeValues(Loc))
858 // Need to add a new DebugLocEntry. Add all values from still
859 // valid non-overlapping pieces.
860 if (OpenRanges.size())
861 Loc.addValues(OpenRanges);
863 DebugLoc.push_back(std::move(Loc));
866 // Attempt to coalesce the ranges of two otherwise identical
868 auto CurEntry = DebugLoc.rbegin();
870 dbgs() << CurEntry->getValues().size() << " Values:\n";
871 for (auto &Value : CurEntry->getValues())
872 Value.getExpression()->dump();
876 auto PrevEntry = std::next(CurEntry);
877 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
882 DbgVariable *DwarfDebug::createConcreteVariable(LexicalScope &Scope,
883 InlinedVariable IV) {
884 ensureAbstractVariableIsCreatedIfScoped(IV, Scope.getScopeNode());
885 ConcreteVariables.push_back(
886 make_unique<DbgVariable>(IV.first, IV.second, this));
887 InfoHolder.addScopeVariable(&Scope, ConcreteVariables.back().get());
888 return ConcreteVariables.back().get();
891 // Find variables for each lexical scope.
892 void DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU,
893 const DISubprogram *SP,
894 DenseSet<InlinedVariable> &Processed) {
895 // Grab the variable info that was squirreled away in the MMI side-table.
896 collectVariableInfoFromMMITable(Processed);
898 for (const auto &I : DbgValues) {
899 InlinedVariable IV = I.first;
900 if (Processed.count(IV))
903 // Instruction ranges, specifying where IV is accessible.
904 const auto &Ranges = I.second;
908 LexicalScope *Scope = nullptr;
909 if (const DILocation *IA = IV.second)
910 Scope = LScopes.findInlinedScope(IV.first->getScope(), IA);
912 Scope = LScopes.findLexicalScope(IV.first->getScope());
913 // If variable scope is not found then skip this variable.
917 Processed.insert(IV);
918 DbgVariable *RegVar = createConcreteVariable(*Scope, IV);
920 const MachineInstr *MInsn = Ranges.front().first;
921 assert(MInsn->isDebugValue() && "History must begin with debug value");
923 // Check if the first DBG_VALUE is valid for the rest of the function.
924 if (Ranges.size() == 1 && Ranges.front().second == nullptr) {
925 RegVar->initializeDbgValue(MInsn);
929 // Handle multiple DBG_VALUE instructions describing one variable.
930 DebugLocStream::ListBuilder List(DebugLocs, TheCU, *Asm, *RegVar, *MInsn);
932 // Build the location list for this variable.
933 SmallVector<DebugLocEntry, 8> Entries;
934 buildLocationList(Entries, Ranges);
936 // If the variable has an DIBasicType, extract it. Basic types cannot have
937 // unique identifiers, so don't bother resolving the type with the
939 const DIBasicType *BT = dyn_cast<DIBasicType>(
940 static_cast<const Metadata *>(IV.first->getType()));
942 // Finalize the entry by lowering it into a DWARF bytestream.
943 for (auto &Entry : Entries)
944 Entry.finalize(*Asm, List, BT);
947 // Collect info for variables that were optimized out.
948 for (const DILocalVariable *DV : SP->getVariables()) {
949 if (Processed.insert(InlinedVariable(DV, nullptr)).second)
950 if (LexicalScope *Scope = LScopes.findLexicalScope(DV->getScope()))
951 createConcreteVariable(*Scope, InlinedVariable(DV, nullptr));
955 // Return Label preceding the instruction.
956 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
957 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
958 assert(Label && "Didn't insert label before instruction");
962 // Return Label immediately following the instruction.
963 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
964 return LabelsAfterInsn.lookup(MI);
967 // Process beginning of an instruction.
968 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
969 assert(CurMI == nullptr);
971 // Check if source location changes, but ignore DBG_VALUE locations.
972 if (!MI->isDebugValue()) {
973 DebugLoc DL = MI->getDebugLoc();
974 if (DL != PrevInstLoc) {
978 if (DL == PrologEndLoc) {
979 Flags |= DWARF2_FLAG_PROLOGUE_END;
980 PrologEndLoc = DebugLoc();
981 Flags |= DWARF2_FLAG_IS_STMT;
984 Asm->OutStreamer->getContext().getCurrentDwarfLoc().getLine())
985 Flags |= DWARF2_FLAG_IS_STMT;
987 const MDNode *Scope = DL.getScope();
988 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
989 } else if (UnknownLocations) {
991 recordSourceLine(0, 0, nullptr, 0);
996 // Insert labels where requested.
997 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
998 LabelsBeforeInsn.find(MI);
1001 if (I == LabelsBeforeInsn.end())
1004 // Label already assigned.
1009 PrevLabel = MMI->getContext().createTempSymbol();
1010 Asm->OutStreamer->EmitLabel(PrevLabel);
1012 I->second = PrevLabel;
1015 // Process end of an instruction.
1016 void DwarfDebug::endInstruction() {
1017 assert(CurMI != nullptr);
1018 // Don't create a new label after DBG_VALUE instructions.
1019 // They don't generate code.
1020 if (!CurMI->isDebugValue())
1021 PrevLabel = nullptr;
1023 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1024 LabelsAfterInsn.find(CurMI);
1028 if (I == LabelsAfterInsn.end())
1031 // Label already assigned.
1035 // We need a label after this instruction.
1037 PrevLabel = MMI->getContext().createTempSymbol();
1038 Asm->OutStreamer->EmitLabel(PrevLabel);
1040 I->second = PrevLabel;
1043 // Each LexicalScope has first instruction and last instruction to mark
1044 // beginning and end of a scope respectively. Create an inverse map that list
1045 // scopes starts (and ends) with an instruction. One instruction may start (or
1046 // end) multiple scopes. Ignore scopes that are not reachable.
1047 void DwarfDebug::identifyScopeMarkers() {
1048 SmallVector<LexicalScope *, 4> WorkList;
1049 WorkList.push_back(LScopes.getCurrentFunctionScope());
1050 while (!WorkList.empty()) {
1051 LexicalScope *S = WorkList.pop_back_val();
1053 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1054 if (!Children.empty())
1055 WorkList.append(Children.begin(), Children.end());
1057 if (S->isAbstractScope())
1060 for (const InsnRange &R : S->getRanges()) {
1061 assert(R.first && "InsnRange does not have first instruction!");
1062 assert(R.second && "InsnRange does not have second instruction!");
1063 requestLabelBeforeInsn(R.first);
1064 requestLabelAfterInsn(R.second);
1069 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1070 // First known non-DBG_VALUE and non-frame setup location marks
1071 // the beginning of the function body.
1072 for (const auto &MBB : *MF)
1073 for (const auto &MI : MBB)
1074 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1076 // Did the target forget to set the FrameSetup flag for CFI insns?
1077 assert(!MI.isCFIInstruction() &&
1078 "First non-frame-setup instruction is a CFI instruction.");
1079 return MI.getDebugLoc();
1084 // Gather pre-function debug information. Assumes being called immediately
1085 // after the function entry point has been emitted.
1086 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1089 // If there's no debug info for the function we're not going to do anything.
1090 if (!MMI->hasDebugInfo())
1093 auto DI = FunctionDIs.find(MF->getFunction());
1094 if (DI == FunctionDIs.end())
1097 // Grab the lexical scopes for the function, if we don't have any of those
1098 // then we're not going to be able to do anything.
1099 LScopes.initialize(*MF);
1100 if (LScopes.empty())
1103 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1105 // Make sure that each lexical scope will have a begin/end label.
1106 identifyScopeMarkers();
1108 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1109 // belongs to so that we add to the correct per-cu line table in the
1111 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1112 // FnScope->getScopeNode() and DI->second should represent the same function,
1113 // though they may not be the same MDNode due to inline functions merged in
1114 // LTO where the debug info metadata still differs (either due to distinct
1115 // written differences - two versions of a linkonce_odr function
1116 // written/copied into two separate files, or some sub-optimal metadata that
1117 // isn't structurally identical (see: file path/name info from clang, which
1118 // includes the directory of the cpp file being built, even when the file name
1119 // is absolute (such as an <> lookup header)))
1120 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1121 assert(TheCU && "Unable to find compile unit!");
1122 if (Asm->OutStreamer->hasRawTextSupport())
1123 // Use a single line table if we are generating assembly.
1124 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
1126 Asm->OutStreamer->getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1128 // Calculate history for local variables.
1129 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1132 // Request labels for the full history.
1133 for (const auto &I : DbgValues) {
1134 const auto &Ranges = I.second;
1138 // The first mention of a function argument gets the CurrentFnBegin
1139 // label, so arguments are visible when breaking at function entry.
1140 const DILocalVariable *DIVar = Ranges.front().first->getDebugVariable();
1141 if (DIVar->getTag() == dwarf::DW_TAG_arg_variable &&
1142 getDISubprogram(DIVar->getScope())->describes(MF->getFunction())) {
1143 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1144 if (Ranges.front().first->getDebugExpression()->isBitPiece()) {
1145 // Mark all non-overlapping initial pieces.
1146 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1147 const DIExpression *Piece = I->first->getDebugExpression();
1148 if (std::all_of(Ranges.begin(), I,
1149 [&](DbgValueHistoryMap::InstrRange Pred) {
1150 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1152 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1159 for (const auto &Range : Ranges) {
1160 requestLabelBeforeInsn(Range.first);
1162 requestLabelAfterInsn(Range.second);
1166 PrevInstLoc = DebugLoc();
1167 PrevLabel = Asm->getFunctionBegin();
1169 // Record beginning of function.
1170 PrologEndLoc = findPrologueEndLoc(MF);
1171 if (DILocation *L = PrologEndLoc) {
1172 // We'd like to list the prologue as "not statements" but GDB behaves
1173 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1174 auto *SP = L->getInlinedAtScope()->getSubprogram();
1175 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1179 // Gather and emit post-function debug information.
1180 void DwarfDebug::endFunction(const MachineFunction *MF) {
1181 assert(CurFn == MF &&
1182 "endFunction should be called with the same function as beginFunction");
1184 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1185 !FunctionDIs.count(MF->getFunction())) {
1186 // If we don't have a lexical scope for this function then there will
1187 // be a hole in the range information. Keep note of this by setting the
1188 // previously used section to nullptr.
1194 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1195 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
1197 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1198 auto *SP = cast<DISubprogram>(FnScope->getScopeNode());
1199 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1201 DenseSet<InlinedVariable> ProcessedVars;
1202 collectVariableInfo(TheCU, SP, ProcessedVars);
1204 // Add the range of this function to the list of ranges for the CU.
1205 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1207 // Under -gmlt, skip building the subprogram if there are no inlined
1208 // subroutines inside it.
1209 if (TheCU.getCUNode()->getEmissionKind() == DIBuilder::LineTablesOnly &&
1210 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1211 assert(InfoHolder.getScopeVariables().empty());
1212 assert(DbgValues.empty());
1213 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1214 // by a -gmlt CU. Add a test and remove this assertion.
1215 assert(AbstractVariables.empty());
1216 LabelsBeforeInsn.clear();
1217 LabelsAfterInsn.clear();
1218 PrevLabel = nullptr;
1224 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1226 // Construct abstract scopes.
1227 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1228 auto *SP = cast<DISubprogram>(AScope->getScopeNode());
1229 // Collect info for variables that were optimized out.
1230 for (const DILocalVariable *DV : SP->getVariables()) {
1231 if (!ProcessedVars.insert(InlinedVariable(DV, nullptr)).second)
1233 ensureAbstractVariableIsCreated(InlinedVariable(DV, nullptr),
1235 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1236 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1238 constructAbstractSubprogramScopeDIE(AScope);
1241 TheCU.constructSubprogramScopeDIE(FnScope);
1242 if (auto *SkelCU = TheCU.getSkeleton())
1243 if (!LScopes.getAbstractScopesList().empty())
1244 SkelCU->constructSubprogramScopeDIE(FnScope);
1247 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1248 // DbgVariables except those that are also in AbstractVariables (since they
1249 // can be used cross-function)
1250 InfoHolder.getScopeVariables().clear();
1252 LabelsBeforeInsn.clear();
1253 LabelsAfterInsn.clear();
1254 PrevLabel = nullptr;
1258 // Register a source line with debug info. Returns the unique label that was
1259 // emitted and which provides correspondence to the source line list.
1260 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1265 unsigned Discriminator = 0;
1266 if (auto *Scope = cast_or_null<DIScope>(S)) {
1267 Fn = Scope->getFilename();
1268 Dir = Scope->getDirectory();
1269 if (auto *LBF = dyn_cast<DILexicalBlockFile>(Scope))
1270 Discriminator = LBF->getDiscriminator();
1272 unsigned CUID = Asm->OutStreamer->getContext().getDwarfCompileUnitID();
1273 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1274 .getOrCreateSourceID(Fn, Dir);
1276 Asm->OutStreamer->EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1280 //===----------------------------------------------------------------------===//
1282 //===----------------------------------------------------------------------===//
1284 // Emit the debug info section.
1285 void DwarfDebug::emitDebugInfo() {
1286 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1287 Holder.emitUnits(/* UseOffsets */ false);
1290 // Emit the abbreviation section.
1291 void DwarfDebug::emitAbbreviations() {
1292 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1294 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1297 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, MCSection *Section,
1298 StringRef TableName) {
1299 Accel.FinalizeTable(Asm, TableName);
1300 Asm->OutStreamer->SwitchSection(Section);
1302 // Emit the full data.
1303 Accel.emit(Asm, Section->getBeginSymbol(), this);
1306 // Emit visible names into a hashed accelerator table section.
1307 void DwarfDebug::emitAccelNames() {
1308 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1312 // Emit objective C classes and categories into a hashed accelerator table
1314 void DwarfDebug::emitAccelObjC() {
1315 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1319 // Emit namespace dies into a hashed accelerator table.
1320 void DwarfDebug::emitAccelNamespaces() {
1321 emitAccel(AccelNamespace,
1322 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1326 // Emit type dies into a hashed accelerator table.
1327 void DwarfDebug::emitAccelTypes() {
1328 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1332 // Public name handling.
1333 // The format for the various pubnames:
1335 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1336 // for the DIE that is named.
1338 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1339 // into the CU and the index value is computed according to the type of value
1340 // for the DIE that is named.
1342 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1343 // it's the offset within the debug_info/debug_types dwo section, however, the
1344 // reference in the pubname header doesn't change.
1346 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1347 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1349 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1351 // We could have a specification DIE that has our most of our knowledge,
1352 // look for that now.
1353 if (DIEValue SpecVal = Die->findAttribute(dwarf::DW_AT_specification)) {
1354 DIE &SpecDIE = SpecVal.getDIEEntry().getEntry();
1355 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1356 Linkage = dwarf::GIEL_EXTERNAL;
1357 } else if (Die->findAttribute(dwarf::DW_AT_external))
1358 Linkage = dwarf::GIEL_EXTERNAL;
1360 switch (Die->getTag()) {
1361 case dwarf::DW_TAG_class_type:
1362 case dwarf::DW_TAG_structure_type:
1363 case dwarf::DW_TAG_union_type:
1364 case dwarf::DW_TAG_enumeration_type:
1365 return dwarf::PubIndexEntryDescriptor(
1366 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1367 ? dwarf::GIEL_STATIC
1368 : dwarf::GIEL_EXTERNAL);
1369 case dwarf::DW_TAG_typedef:
1370 case dwarf::DW_TAG_base_type:
1371 case dwarf::DW_TAG_subrange_type:
1372 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1373 case dwarf::DW_TAG_namespace:
1374 return dwarf::GIEK_TYPE;
1375 case dwarf::DW_TAG_subprogram:
1376 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1377 case dwarf::DW_TAG_variable:
1378 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1379 case dwarf::DW_TAG_enumerator:
1380 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1381 dwarf::GIEL_STATIC);
1383 return dwarf::GIEK_NONE;
1387 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1389 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1390 MCSection *PSec = GnuStyle
1391 ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1392 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1394 emitDebugPubSection(GnuStyle, PSec, "Names",
1395 &DwarfCompileUnit::getGlobalNames);
1398 void DwarfDebug::emitDebugPubSection(
1399 bool GnuStyle, MCSection *PSec, StringRef Name,
1400 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1401 for (const auto &NU : CUMap) {
1402 DwarfCompileUnit *TheU = NU.second;
1404 const auto &Globals = (TheU->*Accessor)();
1406 if (Globals.empty())
1409 if (auto *Skeleton = TheU->getSkeleton())
1412 // Start the dwarf pubnames section.
1413 Asm->OutStreamer->SwitchSection(PSec);
1416 Asm->OutStreamer->AddComment("Length of Public " + Name + " Info");
1417 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1418 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1419 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1421 Asm->OutStreamer->EmitLabel(BeginLabel);
1423 Asm->OutStreamer->AddComment("DWARF Version");
1424 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1426 Asm->OutStreamer->AddComment("Offset of Compilation Unit Info");
1427 Asm->emitDwarfSymbolReference(TheU->getLabelBegin());
1429 Asm->OutStreamer->AddComment("Compilation Unit Length");
1430 Asm->EmitInt32(TheU->getLength());
1432 // Emit the pubnames for this compilation unit.
1433 for (const auto &GI : Globals) {
1434 const char *Name = GI.getKeyData();
1435 const DIE *Entity = GI.second;
1437 Asm->OutStreamer->AddComment("DIE offset");
1438 Asm->EmitInt32(Entity->getOffset());
1441 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1442 Asm->OutStreamer->AddComment(
1443 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1444 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1445 Asm->EmitInt8(Desc.toBits());
1448 Asm->OutStreamer->AddComment("External Name");
1449 Asm->OutStreamer->EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1452 Asm->OutStreamer->AddComment("End Mark");
1454 Asm->OutStreamer->EmitLabel(EndLabel);
1458 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1459 MCSection *PSec = GnuStyle
1460 ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1461 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1463 emitDebugPubSection(GnuStyle, PSec, "Types",
1464 &DwarfCompileUnit::getGlobalTypes);
1467 // Emit visible names into a debug str section.
1468 void DwarfDebug::emitDebugStr() {
1469 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1470 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1473 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1474 const DebugLocStream::Entry &Entry) {
1475 auto &&Comments = DebugLocs.getComments(Entry);
1476 auto Comment = Comments.begin();
1477 auto End = Comments.end();
1478 for (uint8_t Byte : DebugLocs.getBytes(Entry))
1479 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1482 static void emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
1483 ByteStreamer &Streamer,
1484 const DebugLocEntry::Value &Value,
1485 unsigned PieceOffsetInBits) {
1486 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1487 AP.getDwarfDebug()->getDwarfVersion(),
1490 if (Value.isInt()) {
1491 if (BT && (BT->getEncoding() == dwarf::DW_ATE_signed ||
1492 BT->getEncoding() == dwarf::DW_ATE_signed_char))
1493 DwarfExpr.AddSignedConstant(Value.getInt());
1495 DwarfExpr.AddUnsignedConstant(Value.getInt());
1496 } else if (Value.isLocation()) {
1497 MachineLocation Loc = Value.getLoc();
1498 const DIExpression *Expr = Value.getExpression();
1499 if (!Expr || !Expr->getNumElements())
1501 AP.EmitDwarfRegOp(Streamer, Loc);
1503 // Complex address entry.
1504 if (Loc.getOffset()) {
1505 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1506 DwarfExpr.AddExpression(Expr->expr_op_begin(), Expr->expr_op_end(),
1509 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1513 // else ... ignore constant fp. There is not any good way to
1514 // to represent them here in dwarf.
1518 void DebugLocEntry::finalize(const AsmPrinter &AP,
1519 DebugLocStream::ListBuilder &List,
1520 const DIBasicType *BT) {
1521 DebugLocStream::EntryBuilder Entry(List, Begin, End);
1522 BufferByteStreamer Streamer = Entry.getStreamer();
1523 const DebugLocEntry::Value &Value = Values[0];
1524 if (Value.isBitPiece()) {
1525 // Emit all pieces that belong to the same variable and range.
1526 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1527 return P.isBitPiece();
1528 }) && "all values are expected to be pieces");
1529 assert(std::is_sorted(Values.begin(), Values.end()) &&
1530 "pieces are expected to be sorted");
1532 unsigned Offset = 0;
1533 for (auto Piece : Values) {
1534 const DIExpression *Expr = Piece.getExpression();
1535 unsigned PieceOffset = Expr->getBitPieceOffset();
1536 unsigned PieceSize = Expr->getBitPieceSize();
1537 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1538 if (Offset < PieceOffset) {
1539 // The DWARF spec seriously mandates pieces with no locations for gaps.
1540 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1541 AP.getDwarfDebug()->getDwarfVersion(),
1543 Expr.AddOpPiece(PieceOffset-Offset, 0);
1544 Offset += PieceOffset-Offset;
1546 Offset += PieceSize;
1548 emitDebugLocValue(AP, BT, Streamer, Piece, PieceOffset);
1551 assert(Values.size() == 1 && "only pieces may have >1 value");
1552 emitDebugLocValue(AP, BT, Streamer, Value, 0);
1556 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry) {
1558 Asm->OutStreamer->AddComment("Loc expr size");
1559 Asm->EmitInt16(DebugLocs.getBytes(Entry).size());
1562 APByteStreamer Streamer(*Asm);
1563 emitDebugLocEntry(Streamer, Entry);
1566 // Emit locations into the debug loc section.
1567 void DwarfDebug::emitDebugLoc() {
1568 // Start the dwarf loc section.
1569 Asm->OutStreamer->SwitchSection(
1570 Asm->getObjFileLowering().getDwarfLocSection());
1571 unsigned char Size = Asm->getDataLayout().getPointerSize();
1572 for (const auto &List : DebugLocs.getLists()) {
1573 Asm->OutStreamer->EmitLabel(List.Label);
1574 const DwarfCompileUnit *CU = List.CU;
1575 for (const auto &Entry : DebugLocs.getEntries(List)) {
1576 // Set up the range. This range is relative to the entry point of the
1577 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1578 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1579 if (auto *Base = CU->getBaseAddress()) {
1580 Asm->EmitLabelDifference(Entry.BeginSym, Base, Size);
1581 Asm->EmitLabelDifference(Entry.EndSym, Base, Size);
1583 Asm->OutStreamer->EmitSymbolValue(Entry.BeginSym, Size);
1584 Asm->OutStreamer->EmitSymbolValue(Entry.EndSym, Size);
1587 emitDebugLocEntryLocation(Entry);
1589 Asm->OutStreamer->EmitIntValue(0, Size);
1590 Asm->OutStreamer->EmitIntValue(0, Size);
1594 void DwarfDebug::emitDebugLocDWO() {
1595 Asm->OutStreamer->SwitchSection(
1596 Asm->getObjFileLowering().getDwarfLocDWOSection());
1597 for (const auto &List : DebugLocs.getLists()) {
1598 Asm->OutStreamer->EmitLabel(List.Label);
1599 for (const auto &Entry : DebugLocs.getEntries(List)) {
1600 // Just always use start_length for now - at least that's one address
1601 // rather than two. We could get fancier and try to, say, reuse an
1602 // address we know we've emitted elsewhere (the start of the function?
1603 // The start of the CU or CU subrange that encloses this range?)
1604 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1605 unsigned idx = AddrPool.getIndex(Entry.BeginSym);
1606 Asm->EmitULEB128(idx);
1607 Asm->EmitLabelDifference(Entry.EndSym, Entry.BeginSym, 4);
1609 emitDebugLocEntryLocation(Entry);
1611 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1616 const MCSymbol *Start, *End;
1619 // Emit a debug aranges section, containing a CU lookup for any
1620 // address we can tie back to a CU.
1621 void DwarfDebug::emitDebugARanges() {
1622 // Provides a unique id per text section.
1623 MapVector<MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1625 // Filter labels by section.
1626 for (const SymbolCU &SCU : ArangeLabels) {
1627 if (SCU.Sym->isInSection()) {
1628 // Make a note of this symbol and it's section.
1629 MCSection *Section = &SCU.Sym->getSection();
1630 if (!Section->getKind().isMetadata())
1631 SectionMap[Section].push_back(SCU);
1633 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1634 // appear in the output. This sucks as we rely on sections to build
1635 // arange spans. We can do it without, but it's icky.
1636 SectionMap[nullptr].push_back(SCU);
1640 // Add terminating symbols for each section.
1641 for (const auto &I : SectionMap) {
1642 MCSection *Section = I.first;
1643 MCSymbol *Sym = nullptr;
1646 Sym = Asm->OutStreamer->endSection(Section);
1648 // Insert a final terminator.
1649 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1652 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1654 for (auto &I : SectionMap) {
1655 const MCSection *Section = I.first;
1656 SmallVector<SymbolCU, 8> &List = I.second;
1657 if (List.size() < 2)
1660 // If we have no section (e.g. common), just write out
1661 // individual spans for each symbol.
1663 for (const SymbolCU &Cur : List) {
1665 Span.Start = Cur.Sym;
1668 Spans[Cur.CU].push_back(Span);
1673 // Sort the symbols by offset within the section.
1674 std::sort(List.begin(), List.end(),
1675 [&](const SymbolCU &A, const SymbolCU &B) {
1676 unsigned IA = A.Sym ? Asm->OutStreamer->GetSymbolOrder(A.Sym) : 0;
1677 unsigned IB = B.Sym ? Asm->OutStreamer->GetSymbolOrder(B.Sym) : 0;
1679 // Symbols with no order assigned should be placed at the end.
1680 // (e.g. section end labels)
1688 // Build spans between each label.
1689 const MCSymbol *StartSym = List[0].Sym;
1690 for (size_t n = 1, e = List.size(); n < e; n++) {
1691 const SymbolCU &Prev = List[n - 1];
1692 const SymbolCU &Cur = List[n];
1694 // Try and build the longest span we can within the same CU.
1695 if (Cur.CU != Prev.CU) {
1697 Span.Start = StartSym;
1699 Spans[Prev.CU].push_back(Span);
1705 // Start the dwarf aranges section.
1706 Asm->OutStreamer->SwitchSection(
1707 Asm->getObjFileLowering().getDwarfARangesSection());
1709 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1711 // Build a list of CUs used.
1712 std::vector<DwarfCompileUnit *> CUs;
1713 for (const auto &it : Spans) {
1714 DwarfCompileUnit *CU = it.first;
1718 // Sort the CU list (again, to ensure consistent output order).
1719 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1720 return A->getUniqueID() < B->getUniqueID();
1723 // Emit an arange table for each CU we used.
1724 for (DwarfCompileUnit *CU : CUs) {
1725 std::vector<ArangeSpan> &List = Spans[CU];
1727 // Describe the skeleton CU's offset and length, not the dwo file's.
1728 if (auto *Skel = CU->getSkeleton())
1731 // Emit size of content not including length itself.
1732 unsigned ContentSize =
1733 sizeof(int16_t) + // DWARF ARange version number
1734 sizeof(int32_t) + // Offset of CU in the .debug_info section
1735 sizeof(int8_t) + // Pointer Size (in bytes)
1736 sizeof(int8_t); // Segment Size (in bytes)
1738 unsigned TupleSize = PtrSize * 2;
1740 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1742 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1744 ContentSize += Padding;
1745 ContentSize += (List.size() + 1) * TupleSize;
1747 // For each compile unit, write the list of spans it covers.
1748 Asm->OutStreamer->AddComment("Length of ARange Set");
1749 Asm->EmitInt32(ContentSize);
1750 Asm->OutStreamer->AddComment("DWARF Arange version number");
1751 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1752 Asm->OutStreamer->AddComment("Offset Into Debug Info Section");
1753 Asm->emitDwarfSymbolReference(CU->getLabelBegin());
1754 Asm->OutStreamer->AddComment("Address Size (in bytes)");
1755 Asm->EmitInt8(PtrSize);
1756 Asm->OutStreamer->AddComment("Segment Size (in bytes)");
1759 Asm->OutStreamer->EmitFill(Padding, 0xff);
1761 for (const ArangeSpan &Span : List) {
1762 Asm->EmitLabelReference(Span.Start, PtrSize);
1764 // Calculate the size as being from the span start to it's end.
1766 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1768 // For symbols without an end marker (e.g. common), we
1769 // write a single arange entry containing just that one symbol.
1770 uint64_t Size = SymSize[Span.Start];
1774 Asm->OutStreamer->EmitIntValue(Size, PtrSize);
1778 Asm->OutStreamer->AddComment("ARange terminator");
1779 Asm->OutStreamer->EmitIntValue(0, PtrSize);
1780 Asm->OutStreamer->EmitIntValue(0, PtrSize);
1784 // Emit visible names into a debug ranges section.
1785 void DwarfDebug::emitDebugRanges() {
1786 // Start the dwarf ranges section.
1787 Asm->OutStreamer->SwitchSection(
1788 Asm->getObjFileLowering().getDwarfRangesSection());
1790 // Size for our labels.
1791 unsigned char Size = Asm->getDataLayout().getPointerSize();
1793 // Grab the specific ranges for the compile units in the module.
1794 for (const auto &I : CUMap) {
1795 DwarfCompileUnit *TheCU = I.second;
1797 if (auto *Skel = TheCU->getSkeleton())
1800 // Iterate over the misc ranges for the compile units in the module.
1801 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1802 // Emit our symbol so we can find the beginning of the range.
1803 Asm->OutStreamer->EmitLabel(List.getSym());
1805 for (const RangeSpan &Range : List.getRanges()) {
1806 const MCSymbol *Begin = Range.getStart();
1807 const MCSymbol *End = Range.getEnd();
1808 assert(Begin && "Range without a begin symbol?");
1809 assert(End && "Range without an end symbol?");
1810 if (auto *Base = TheCU->getBaseAddress()) {
1811 Asm->EmitLabelDifference(Begin, Base, Size);
1812 Asm->EmitLabelDifference(End, Base, Size);
1814 Asm->OutStreamer->EmitSymbolValue(Begin, Size);
1815 Asm->OutStreamer->EmitSymbolValue(End, Size);
1819 // And terminate the list with two 0 values.
1820 Asm->OutStreamer->EmitIntValue(0, Size);
1821 Asm->OutStreamer->EmitIntValue(0, Size);
1826 // DWARF5 Experimental Separate Dwarf emitters.
1828 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1829 std::unique_ptr<DwarfUnit> NewU) {
1830 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1831 U.getCUNode()->getSplitDebugFilename());
1833 if (!CompilationDir.empty())
1834 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1836 addGnuPubAttributes(*NewU, Die);
1838 SkeletonHolder.addUnit(std::move(NewU));
1841 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1842 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1843 // DW_AT_addr_base, DW_AT_ranges_base.
1844 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1846 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1847 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1848 DwarfCompileUnit &NewCU = *OwnedUnit;
1849 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1851 NewCU.initStmtList();
1853 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1858 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1859 // compile units that would normally be in debug_info.
1860 void DwarfDebug::emitDebugInfoDWO() {
1861 assert(useSplitDwarf() && "No split dwarf debug info?");
1862 // Don't emit relocations into the dwo file.
1863 InfoHolder.emitUnits(/* UseOffsets */ true);
1866 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1867 // abbreviations for the .debug_info.dwo section.
1868 void DwarfDebug::emitDebugAbbrevDWO() {
1869 assert(useSplitDwarf() && "No split dwarf?");
1870 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1873 void DwarfDebug::emitDebugLineDWO() {
1874 assert(useSplitDwarf() && "No split dwarf?");
1875 Asm->OutStreamer->SwitchSection(
1876 Asm->getObjFileLowering().getDwarfLineDWOSection());
1877 SplitTypeUnitFileTable.Emit(*Asm->OutStreamer);
1880 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1881 // string section and is identical in format to traditional .debug_str
1883 void DwarfDebug::emitDebugStrDWO() {
1884 assert(useSplitDwarf() && "No split dwarf?");
1885 MCSection *OffSec = Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1886 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1890 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1891 if (!useSplitDwarf())
1894 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode()->getDirectory());
1895 return &SplitTypeUnitFileTable;
1898 static uint64_t makeTypeSignature(StringRef Identifier) {
1900 Hash.update(Identifier);
1901 // ... take the least significant 8 bytes and return those. Our MD5
1902 // implementation always returns its results in little endian, swap bytes
1904 MD5::MD5Result Result;
1906 return support::endian::read64le(Result + 8);
1909 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1910 StringRef Identifier, DIE &RefDie,
1911 const DICompositeType *CTy) {
1912 // Fast path if we're building some type units and one has already used the
1913 // address pool we know we're going to throw away all this work anyway, so
1914 // don't bother building dependent types.
1915 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1918 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1920 CU.addDIETypeSignature(RefDie, *TU);
1924 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1925 AddrPool.resetUsedFlag();
1927 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1928 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1929 this, &InfoHolder, getDwoLineTable(CU));
1930 DwarfTypeUnit &NewTU = *OwnedUnit;
1931 DIE &UnitDie = NewTU.getUnitDie();
1933 TypeUnitsUnderConstruction.push_back(
1934 std::make_pair(std::move(OwnedUnit), CTy));
1936 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1939 uint64_t Signature = makeTypeSignature(Identifier);
1940 NewTU.setTypeSignature(Signature);
1942 if (useSplitDwarf())
1943 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1945 CU.applyStmtList(UnitDie);
1947 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1950 NewTU.setType(NewTU.createTypeDIE(CTy));
1953 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1954 TypeUnitsUnderConstruction.clear();
1956 // Types referencing entries in the address table cannot be placed in type
1958 if (AddrPool.hasBeenUsed()) {
1960 // Remove all the types built while building this type.
1961 // This is pessimistic as some of these types might not be dependent on
1962 // the type that used an address.
1963 for (const auto &TU : TypeUnitsToAdd)
1964 DwarfTypeUnits.erase(TU.second);
1966 // Construct this type in the CU directly.
1967 // This is inefficient because all the dependent types will be rebuilt
1968 // from scratch, including building them in type units, discovering that
1969 // they depend on addresses, throwing them out and rebuilding them.
1970 CU.constructTypeDIE(RefDie, cast<DICompositeType>(CTy));
1974 // If the type wasn't dependent on fission addresses, finish adding the type
1975 // and all its dependent types.
1976 for (auto &TU : TypeUnitsToAdd)
1977 InfoHolder.addUnit(std::move(TU.first));
1979 CU.addDIETypeSignature(RefDie, NewTU);
1982 // Accelerator table mutators - add each name along with its companion
1983 // DIE to the proper table while ensuring that the name that we're going
1984 // to reference is in the string table. We do this since the names we
1985 // add may not only be identical to the names in the DIE.
1986 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
1987 if (!useDwarfAccelTables())
1989 AccelNames.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
1992 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
1993 if (!useDwarfAccelTables())
1995 AccelObjC.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
1998 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
1999 if (!useDwarfAccelTables())
2001 AccelNamespace.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
2004 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2005 if (!useDwarfAccelTables())
2007 AccelTypes.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);