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.getNumElements(); i < N; ++i) {
178 DIDerivedType DT = cast<MDDerivedTypeBase>(Elements.getElement(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.getContext()))
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 DIArray ImportedEntities = CUNode.getImportedEntities();
449 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
450 ScopesWithImportedEntities.push_back(std::make_pair(
451 cast<MDImportedEntity>(ImportedEntities.getElement(i))->getScope(),
452 ImportedEntities.getElement(i)));
453 // Stable sort to preserve the order of appearance of imported entities.
454 // This is to avoid out-of-order processing of interdependent declarations
455 // within the same scope, e.g. { namespace A = base; namespace B = A; }
456 std::stable_sort(ScopesWithImportedEntities.begin(),
457 ScopesWithImportedEntities.end(), less_first());
458 DIArray GVs = CUNode.getGlobalVariables();
459 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
460 CU.getOrCreateGlobalVariableDIE(
461 cast<MDGlobalVariable>(GVs.getElement(i)));
462 DIArray SPs = CUNode.getSubprograms();
463 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
464 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
465 DIArray EnumTypes = CUNode.getEnumTypes();
466 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
467 DIType Ty = cast<MDType>(EnumTypes.getElement(i));
468 // The enum types array by design contains pointers to
469 // MDNodes rather than DIRefs. Unique them here.
470 DIType UniqueTy = cast<MDType>(resolve(Ty.getRef()));
471 CU.getOrCreateTypeDIE(UniqueTy);
473 DIArray RetainedTypes = CUNode.getRetainedTypes();
474 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
475 DIType Ty = cast<MDType>(RetainedTypes.getElement(i));
476 // The retained types array by design contains pointers to
477 // MDNodes rather than DIRefs. Unique them here.
478 DIType UniqueTy = cast<MDType>(resolve(Ty.getRef()));
479 CU.getOrCreateTypeDIE(UniqueTy);
481 // Emit imported_modules last so that the relevant context is already
483 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
484 constructAndAddImportedEntityDIE(CU, ImportedEntities.getElement(i));
487 // Tell MMI that we have debug info.
488 MMI->setDebugInfoAvailability(true);
491 void DwarfDebug::finishVariableDefinitions() {
492 for (const auto &Var : ConcreteVariables) {
493 DIE *VariableDie = Var->getDIE();
495 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
496 // in the ConcreteVariables list, rather than looking it up again here.
497 // DIE::getUnit isn't simple - it walks parent pointers, etc.
498 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
500 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
501 if (AbsVar && AbsVar->getDIE()) {
502 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
505 Unit->applyVariableAttributes(*Var, *VariableDie);
509 void DwarfDebug::finishSubprogramDefinitions() {
510 for (const auto &P : SPMap)
511 forBothCUs(*P.second, [&](DwarfCompileUnit &CU) {
512 CU.finishSubprogramDefinition(cast<MDSubprogram>(P.first));
517 // Collect info for variables that were optimized out.
518 void DwarfDebug::collectDeadVariables() {
519 const Module *M = MMI->getModule();
521 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
522 for (MDNode *N : CU_Nodes->operands()) {
523 DICompileUnit TheCU = cast<MDCompileUnit>(N);
524 // Construct subprogram DIE and add variables DIEs.
525 DwarfCompileUnit *SPCU =
526 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
527 assert(SPCU && "Unable to find Compile Unit!");
528 DIArray Subprograms = TheCU.getSubprograms();
529 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
530 DISubprogram SP = cast<MDSubprogram>(Subprograms.getElement(i));
531 if (ProcessedSPNodes.count(SP) != 0)
533 SPCU->collectDeadVariables(SP);
539 void DwarfDebug::finalizeModuleInfo() {
540 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
542 finishSubprogramDefinitions();
544 finishVariableDefinitions();
546 // Collect info for variables that were optimized out.
547 collectDeadVariables();
549 // Handle anything that needs to be done on a per-unit basis after
550 // all other generation.
551 for (const auto &P : CUMap) {
552 auto &TheCU = *P.second;
553 // Emit DW_AT_containing_type attribute to connect types with their
554 // vtable holding type.
555 TheCU.constructContainingTypeDIEs();
557 // Add CU specific attributes if we need to add any.
558 // If we're splitting the dwarf out now that we've got the entire
559 // CU then add the dwo id to it.
560 auto *SkCU = TheCU.getSkeleton();
561 if (useSplitDwarf()) {
562 // Emit a unique identifier for this CU.
563 uint64_t ID = DIEHash(Asm).computeCUSignature(TheCU.getUnitDie());
564 TheCU.addUInt(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
565 dwarf::DW_FORM_data8, ID);
566 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
567 dwarf::DW_FORM_data8, ID);
569 // We don't keep track of which addresses are used in which CU so this
570 // is a bit pessimistic under LTO.
571 if (!AddrPool.isEmpty()) {
572 const MCSymbol *Sym = TLOF.getDwarfAddrSection()->getBeginSymbol();
573 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_addr_base,
576 if (!SkCU->getRangeLists().empty()) {
577 const MCSymbol *Sym = TLOF.getDwarfRangesSection()->getBeginSymbol();
578 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
583 // If we have code split among multiple sections or non-contiguous
584 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
585 // remain in the .o file, otherwise add a DW_AT_low_pc.
586 // FIXME: We should use ranges allow reordering of code ala
587 // .subsections_via_symbols in mach-o. This would mean turning on
588 // ranges for all subprogram DIEs for mach-o.
589 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
590 if (unsigned NumRanges = TheCU.getRanges().size()) {
592 // A DW_AT_low_pc attribute may also be specified in combination with
593 // DW_AT_ranges to specify the default base address for use in
594 // location lists (see Section 2.6.2) and range lists (see Section
596 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
598 TheCU.setBaseAddress(TheCU.getRanges().front().getStart());
599 U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
603 // Compute DIE offsets and sizes.
604 InfoHolder.computeSizeAndOffsets();
606 SkeletonHolder.computeSizeAndOffsets();
609 // Emit all Dwarf sections that should come after the content.
610 void DwarfDebug::endModule() {
611 assert(CurFn == nullptr);
612 assert(CurMI == nullptr);
614 // If we aren't actually generating debug info (check beginModule -
615 // conditionalized on !DisableDebugInfoPrinting and the presence of the
616 // llvm.dbg.cu metadata node)
617 if (!MMI->hasDebugInfo())
620 // Finalize the debug info for the module.
621 finalizeModuleInfo();
628 // Emit info into a debug loc section.
631 // Corresponding abbreviations into a abbrev section.
634 // Emit all the DIEs into a debug info section.
637 // Emit info into a debug aranges section.
638 if (GenerateARangeSection)
641 // Emit info into a debug ranges section.
644 if (useSplitDwarf()) {
647 emitDebugAbbrevDWO();
649 // Emit DWO addresses.
650 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
653 // Emit info into the dwarf accelerator table sections.
654 if (useDwarfAccelTables()) {
657 emitAccelNamespaces();
661 // Emit the pubnames and pubtypes sections if requested.
662 if (HasDwarfPubSections) {
663 emitDebugPubNames(GenerateGnuPubSections);
664 emitDebugPubTypes(GenerateGnuPubSections);
669 AbstractVariables.clear();
672 // Find abstract variable, if any, associated with Var.
673 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
674 DIVariable &Cleansed) {
675 LLVMContext &Ctx = DV->getContext();
676 // More then one inlined variable corresponds to one abstract variable.
677 // FIXME: This duplication of variables when inlining should probably be
678 // removed. It's done to allow each DIVariable to describe its location
679 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
680 // make it accurate then remove this duplication/cleansing stuff.
681 Cleansed = cleanseInlinedVariable(DV, Ctx);
682 auto I = AbstractVariables.find(Cleansed);
683 if (I != AbstractVariables.end())
684 return I->second.get();
688 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
690 return getExistingAbstractVariable(DV, Cleansed);
693 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
694 LexicalScope *Scope) {
695 auto AbsDbgVariable = make_unique<DbgVariable>(Var, DIExpression(), this);
696 InfoHolder.addScopeVariable(Scope, AbsDbgVariable.get());
697 AbstractVariables[Var] = std::move(AbsDbgVariable);
700 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
701 const MDNode *ScopeNode) {
702 DIVariable Cleansed = DV;
703 if (getExistingAbstractVariable(DV, Cleansed))
706 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(
707 cast<MDLocalScope>(ScopeNode)));
711 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
712 const MDNode *ScopeNode) {
713 DIVariable Cleansed = DV;
714 if (getExistingAbstractVariable(DV, Cleansed))
717 if (LexicalScope *Scope =
718 LScopes.findAbstractScope(cast_or_null<MDLocalScope>(ScopeNode)))
719 createAbstractVariable(Cleansed, Scope);
722 // Collect variable information from side table maintained by MMI.
723 void DwarfDebug::collectVariableInfoFromMMITable(
724 SmallPtrSetImpl<const MDNode *> &Processed) {
725 for (const auto &VI : MMI->getVariableDbgInfo()) {
728 Processed.insert(VI.Var);
729 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
731 // If variable scope is not found then skip this variable.
735 DIVariable DV = cast<MDLocalVariable>(VI.Var);
736 assert(DV->isValidLocationForIntrinsic(VI.Loc) &&
737 "Expected inlined-at fields to agree");
738 DIExpression Expr = cast_or_null<MDExpression>(VI.Expr);
739 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
740 auto RegVar = make_unique<DbgVariable>(DV, Expr, this, VI.Slot);
741 if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
742 ConcreteVariables.push_back(std::move(RegVar));
746 // Get .debug_loc entry for the instruction range starting at MI.
747 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
748 const MDNode *Expr = MI->getDebugExpression();
749 const MDNode *Var = MI->getDebugVariable();
751 assert(MI->getNumOperands() == 4);
752 if (MI->getOperand(0).isReg()) {
753 MachineLocation MLoc;
754 // If the second operand is an immediate, this is a
755 // register-indirect address.
756 if (!MI->getOperand(1).isImm())
757 MLoc.set(MI->getOperand(0).getReg());
759 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
760 return DebugLocEntry::Value(Var, Expr, MLoc);
762 if (MI->getOperand(0).isImm())
763 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getImm());
764 if (MI->getOperand(0).isFPImm())
765 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getFPImm());
766 if (MI->getOperand(0).isCImm())
767 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getCImm());
769 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
772 /// Determine whether two variable pieces overlap.
773 static bool piecesOverlap(DIExpression P1, DIExpression P2) {
774 if (!P1.isBitPiece() || !P2.isBitPiece())
776 unsigned l1 = P1.getBitPieceOffset();
777 unsigned l2 = P2.getBitPieceOffset();
778 unsigned r1 = l1 + P1.getBitPieceSize();
779 unsigned r2 = l2 + P2.getBitPieceSize();
780 // True where [l1,r1[ and [r1,r2[ overlap.
781 return (l1 < r2) && (l2 < r1);
784 /// Build the location list for all DBG_VALUEs in the function that
785 /// describe the same variable. If the ranges of several independent
786 /// pieces of the same variable overlap partially, split them up and
787 /// combine the ranges. The resulting DebugLocEntries are will have
788 /// strict monotonically increasing begin addresses and will never
793 // Ranges History [var, loc, piece ofs size]
794 // 0 | [x, (reg0, piece 0, 32)]
795 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
797 // 3 | [clobber reg0]
798 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of
803 // [0-1] [x, (reg0, piece 0, 32)]
804 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
805 // [3-4] [x, (reg1, piece 32, 32)]
806 // [4- ] [x, (mem, piece 0, 64)]
808 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
809 const DbgValueHistoryMap::InstrRanges &Ranges) {
810 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
812 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
813 const MachineInstr *Begin = I->first;
814 const MachineInstr *End = I->second;
815 assert(Begin->isDebugValue() && "Invalid History entry");
817 // Check if a variable is inaccessible in this range.
818 if (Begin->getNumOperands() > 1 &&
819 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
824 // If this piece overlaps with any open ranges, truncate them.
825 DIExpression DIExpr = Begin->getDebugExpression();
826 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
827 [&](DebugLocEntry::Value R) {
828 return piecesOverlap(DIExpr, R.getExpression());
830 OpenRanges.erase(Last, OpenRanges.end());
832 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
833 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
835 const MCSymbol *EndLabel;
837 EndLabel = getLabelAfterInsn(End);
838 else if (std::next(I) == Ranges.end())
839 EndLabel = Asm->getFunctionEnd();
841 EndLabel = getLabelBeforeInsn(std::next(I)->first);
842 assert(EndLabel && "Forgot label after instruction ending a range!");
844 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
846 auto Value = getDebugLocValue(Begin);
847 DebugLocEntry Loc(StartLabel, EndLabel, Value);
848 bool couldMerge = false;
850 // If this is a piece, it may belong to the current DebugLocEntry.
851 if (DIExpr.isBitPiece()) {
852 // Add this value to the list of open ranges.
853 OpenRanges.push_back(Value);
855 // Attempt to add the piece to the last entry.
856 if (!DebugLoc.empty())
857 if (DebugLoc.back().MergeValues(Loc))
862 // Need to add a new DebugLocEntry. Add all values from still
863 // valid non-overlapping pieces.
864 if (OpenRanges.size())
865 Loc.addValues(OpenRanges);
867 DebugLoc.push_back(std::move(Loc));
870 // Attempt to coalesce the ranges of two otherwise identical
872 auto CurEntry = DebugLoc.rbegin();
873 auto PrevEntry = std::next(CurEntry);
874 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
878 dbgs() << CurEntry->getValues().size() << " Values:\n";
879 for (auto Value : CurEntry->getValues()) {
880 Value.getVariable()->dump();
881 Value.getExpression()->dump();
889 // Find variables for each lexical scope.
891 DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU, DISubprogram SP,
892 SmallPtrSetImpl<const MDNode *> &Processed) {
893 // Grab the variable info that was squirreled away in the MMI side-table.
894 collectVariableInfoFromMMITable(Processed);
896 for (const auto &I : DbgValues) {
897 DIVariable DV = cast<MDLocalVariable>(I.first);
898 if (Processed.count(DV))
901 // Instruction ranges, specifying where DV is accessible.
902 const auto &Ranges = I.second;
906 LexicalScope *Scope = nullptr;
907 if (MDLocation *IA = DV.get()->getInlinedAt())
908 Scope = LScopes.findInlinedScope(DV.get()->getScope(), IA);
910 Scope = LScopes.findLexicalScope(DV.get()->getScope());
911 // If variable scope is not found then skip this variable.
915 Processed.insert(DV);
916 const MachineInstr *MInsn = Ranges.front().first;
917 assert(MInsn->isDebugValue() && "History must begin with debug value");
918 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
919 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
920 DbgVariable *RegVar = ConcreteVariables.back().get();
921 InfoHolder.addScopeVariable(Scope, RegVar);
923 // Check if the first DBG_VALUE is valid for the rest of the function.
924 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
927 // Handle multiple DBG_VALUE instructions describing one variable.
928 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
930 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
931 DebugLocList &LocList = DotDebugLocEntries.back();
933 LocList.Label = Asm->createTempSymbol("debug_loc");
935 // Build the location list for this variable.
936 buildLocationList(LocList.List, Ranges);
937 // Finalize the entry by lowering it into a DWARF bytestream.
938 for (auto &Entry : LocList.List)
939 Entry.finalize(*Asm, TypeIdentifierMap);
942 // Collect info for variables that were optimized out.
943 DIArray Variables = SP.getVariables();
944 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
945 DIVariable DV = cast<MDLocalVariable>(Variables.getElement(i));
946 if (!Processed.insert(DV).second)
948 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.get()->getScope())) {
949 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
951 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, NoExpr, this));
952 InfoHolder.addScopeVariable(Scope, ConcreteVariables.back().get());
957 // Return Label preceding the instruction.
958 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
959 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
960 assert(Label && "Didn't insert label before instruction");
964 // Return Label immediately following the instruction.
965 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
966 return LabelsAfterInsn.lookup(MI);
969 // Process beginning of an instruction.
970 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
971 assert(CurMI == nullptr);
973 // Check if source location changes, but ignore DBG_VALUE locations.
974 if (!MI->isDebugValue()) {
975 DebugLoc DL = MI->getDebugLoc();
976 if (DL != PrevInstLoc) {
980 if (DL == PrologEndLoc) {
981 Flags |= DWARF2_FLAG_PROLOGUE_END;
982 PrologEndLoc = DebugLoc();
983 Flags |= DWARF2_FLAG_IS_STMT;
986 Asm->OutStreamer.getContext().getCurrentDwarfLoc().getLine())
987 Flags |= DWARF2_FLAG_IS_STMT;
989 const MDNode *Scope = DL.getScope();
990 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
991 } else if (UnknownLocations) {
993 recordSourceLine(0, 0, nullptr, 0);
998 // Insert labels where requested.
999 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1000 LabelsBeforeInsn.find(MI);
1003 if (I == LabelsBeforeInsn.end())
1006 // Label already assigned.
1011 PrevLabel = MMI->getContext().CreateTempSymbol();
1012 Asm->OutStreamer.EmitLabel(PrevLabel);
1014 I->second = PrevLabel;
1017 // Process end of an instruction.
1018 void DwarfDebug::endInstruction() {
1019 assert(CurMI != nullptr);
1020 // Don't create a new label after DBG_VALUE instructions.
1021 // They don't generate code.
1022 if (!CurMI->isDebugValue())
1023 PrevLabel = nullptr;
1025 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1026 LabelsAfterInsn.find(CurMI);
1030 if (I == LabelsAfterInsn.end())
1033 // Label already assigned.
1037 // We need a label after this instruction.
1039 PrevLabel = MMI->getContext().CreateTempSymbol();
1040 Asm->OutStreamer.EmitLabel(PrevLabel);
1042 I->second = PrevLabel;
1045 // Each LexicalScope has first instruction and last instruction to mark
1046 // beginning and end of a scope respectively. Create an inverse map that list
1047 // scopes starts (and ends) with an instruction. One instruction may start (or
1048 // end) multiple scopes. Ignore scopes that are not reachable.
1049 void DwarfDebug::identifyScopeMarkers() {
1050 SmallVector<LexicalScope *, 4> WorkList;
1051 WorkList.push_back(LScopes.getCurrentFunctionScope());
1052 while (!WorkList.empty()) {
1053 LexicalScope *S = WorkList.pop_back_val();
1055 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1056 if (!Children.empty())
1057 WorkList.append(Children.begin(), Children.end());
1059 if (S->isAbstractScope())
1062 for (const InsnRange &R : S->getRanges()) {
1063 assert(R.first && "InsnRange does not have first instruction!");
1064 assert(R.second && "InsnRange does not have second instruction!");
1065 requestLabelBeforeInsn(R.first);
1066 requestLabelAfterInsn(R.second);
1071 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1072 // First known non-DBG_VALUE and non-frame setup location marks
1073 // the beginning of the function body.
1074 for (const auto &MBB : *MF)
1075 for (const auto &MI : MBB)
1076 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1078 // Did the target forget to set the FrameSetup flag for CFI insns?
1079 assert(!MI.isCFIInstruction() &&
1080 "First non-frame-setup instruction is a CFI instruction.");
1081 return MI.getDebugLoc();
1086 // Gather pre-function debug information. Assumes being called immediately
1087 // after the function entry point has been emitted.
1088 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1091 // If there's no debug info for the function we're not going to do anything.
1092 if (!MMI->hasDebugInfo())
1095 auto DI = FunctionDIs.find(MF->getFunction());
1096 if (DI == FunctionDIs.end())
1099 // Grab the lexical scopes for the function, if we don't have any of those
1100 // then we're not going to be able to do anything.
1101 LScopes.initialize(*MF);
1102 if (LScopes.empty())
1105 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1107 // Make sure that each lexical scope will have a begin/end label.
1108 identifyScopeMarkers();
1110 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1111 // belongs to so that we add to the correct per-cu line table in the
1113 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1114 // FnScope->getScopeNode() and DI->second should represent the same function,
1115 // though they may not be the same MDNode due to inline functions merged in
1116 // LTO where the debug info metadata still differs (either due to distinct
1117 // written differences - two versions of a linkonce_odr function
1118 // written/copied into two separate files, or some sub-optimal metadata that
1119 // isn't structurally identical (see: file path/name info from clang, which
1120 // includes the directory of the cpp file being built, even when the file name
1121 // is absolute (such as an <> lookup header)))
1122 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1123 assert(TheCU && "Unable to find compile unit!");
1124 if (Asm->OutStreamer.hasRawTextSupport())
1125 // Use a single line table if we are generating assembly.
1126 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1128 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1130 // Calculate history for local variables.
1131 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1134 // Request labels for the full history.
1135 for (const auto &I : DbgValues) {
1136 const auto &Ranges = I.second;
1140 // The first mention of a function argument gets the CurrentFnBegin
1141 // label, so arguments are visible when breaking at function entry.
1142 DIVariable DIVar = Ranges.front().first->getDebugVariable();
1143 if (DIVar.getTag() == dwarf::DW_TAG_arg_variable &&
1144 getDISubprogram(DIVar.getContext()).describes(MF->getFunction())) {
1145 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1146 if (Ranges.front().first->getDebugExpression().isBitPiece()) {
1147 // Mark all non-overlapping initial pieces.
1148 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1149 DIExpression Piece = I->first->getDebugExpression();
1150 if (std::all_of(Ranges.begin(), I,
1151 [&](DbgValueHistoryMap::InstrRange Pred) {
1152 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1154 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1161 for (const auto &Range : Ranges) {
1162 requestLabelBeforeInsn(Range.first);
1164 requestLabelAfterInsn(Range.second);
1168 PrevInstLoc = DebugLoc();
1169 PrevLabel = Asm->getFunctionBegin();
1171 // Record beginning of function.
1172 PrologEndLoc = findPrologueEndLoc(MF);
1173 if (MDLocation *L = PrologEndLoc) {
1174 // We'd like to list the prologue as "not statements" but GDB behaves
1175 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1176 auto *SP = L->getInlinedAtScope()->getSubprogram();
1177 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1181 // Gather and emit post-function debug information.
1182 void DwarfDebug::endFunction(const MachineFunction *MF) {
1183 assert(CurFn == MF &&
1184 "endFunction should be called with the same function as beginFunction");
1186 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1187 !FunctionDIs.count(MF->getFunction())) {
1188 // If we don't have a lexical scope for this function then there will
1189 // be a hole in the range information. Keep note of this by setting the
1190 // previously used section to nullptr.
1196 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1197 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1199 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1200 DISubprogram SP = cast<MDSubprogram>(FnScope->getScopeNode());
1201 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1203 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1204 collectVariableInfo(TheCU, SP, ProcessedVars);
1206 // Add the range of this function to the list of ranges for the CU.
1207 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1209 // Under -gmlt, skip building the subprogram if there are no inlined
1210 // subroutines inside it.
1211 if (TheCU.getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly &&
1212 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1213 assert(InfoHolder.getScopeVariables().empty());
1214 assert(DbgValues.empty());
1215 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1216 // by a -gmlt CU. Add a test and remove this assertion.
1217 assert(AbstractVariables.empty());
1218 LabelsBeforeInsn.clear();
1219 LabelsAfterInsn.clear();
1220 PrevLabel = nullptr;
1226 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1228 // Construct abstract scopes.
1229 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1230 DISubprogram SP = cast<MDSubprogram>(AScope->getScopeNode());
1231 // Collect info for variables that were optimized out.
1232 DIArray Variables = SP.getVariables();
1233 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1234 DIVariable DV = cast<MDLocalVariable>(Variables.getElement(i));
1235 if (!ProcessedVars.insert(DV).second)
1237 ensureAbstractVariableIsCreated(DV, DV.getContext());
1238 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1239 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1241 constructAbstractSubprogramScopeDIE(AScope);
1244 TheCU.constructSubprogramScopeDIE(FnScope);
1245 if (auto *SkelCU = TheCU.getSkeleton())
1246 if (!LScopes.getAbstractScopesList().empty())
1247 SkelCU->constructSubprogramScopeDIE(FnScope);
1250 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1251 // DbgVariables except those that are also in AbstractVariables (since they
1252 // can be used cross-function)
1253 InfoHolder.getScopeVariables().clear();
1255 LabelsBeforeInsn.clear();
1256 LabelsAfterInsn.clear();
1257 PrevLabel = nullptr;
1261 // Register a source line with debug info. Returns the unique label that was
1262 // emitted and which provides correspondence to the source line list.
1263 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1268 unsigned Discriminator = 0;
1269 if (DIScope Scope = cast_or_null<MDScope>(S)) {
1270 Fn = Scope.getFilename();
1271 Dir = Scope.getDirectory();
1272 if (DILexicalBlockFile LBF = dyn_cast<MDLexicalBlockFile>(Scope))
1273 Discriminator = LBF.getDiscriminator();
1275 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1276 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1277 .getOrCreateSourceID(Fn, Dir);
1279 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1283 //===----------------------------------------------------------------------===//
1285 //===----------------------------------------------------------------------===//
1287 // Emit the debug info section.
1288 void DwarfDebug::emitDebugInfo() {
1289 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1290 Holder.emitUnits(/* UseOffsets */ false);
1293 // Emit the abbreviation section.
1294 void DwarfDebug::emitAbbreviations() {
1295 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1297 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1300 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1301 StringRef TableName) {
1302 Accel.FinalizeTable(Asm, TableName);
1303 Asm->OutStreamer.SwitchSection(Section);
1305 // Emit the full data.
1306 Accel.emit(Asm, Section->getBeginSymbol(), this);
1309 // Emit visible names into a hashed accelerator table section.
1310 void DwarfDebug::emitAccelNames() {
1311 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1315 // Emit objective C classes and categories into a hashed accelerator table
1317 void DwarfDebug::emitAccelObjC() {
1318 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1322 // Emit namespace dies into a hashed accelerator table.
1323 void DwarfDebug::emitAccelNamespaces() {
1324 emitAccel(AccelNamespace,
1325 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1329 // Emit type dies into a hashed accelerator table.
1330 void DwarfDebug::emitAccelTypes() {
1331 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1335 // Public name handling.
1336 // The format for the various pubnames:
1338 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1339 // for the DIE that is named.
1341 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1342 // into the CU and the index value is computed according to the type of value
1343 // for the DIE that is named.
1345 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1346 // it's the offset within the debug_info/debug_types dwo section, however, the
1347 // reference in the pubname header doesn't change.
1349 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1350 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1352 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1354 // We could have a specification DIE that has our most of our knowledge,
1355 // look for that now.
1356 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1358 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1359 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1360 Linkage = dwarf::GIEL_EXTERNAL;
1361 } else if (Die->findAttribute(dwarf::DW_AT_external))
1362 Linkage = dwarf::GIEL_EXTERNAL;
1364 switch (Die->getTag()) {
1365 case dwarf::DW_TAG_class_type:
1366 case dwarf::DW_TAG_structure_type:
1367 case dwarf::DW_TAG_union_type:
1368 case dwarf::DW_TAG_enumeration_type:
1369 return dwarf::PubIndexEntryDescriptor(
1370 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1371 ? dwarf::GIEL_STATIC
1372 : dwarf::GIEL_EXTERNAL);
1373 case dwarf::DW_TAG_typedef:
1374 case dwarf::DW_TAG_base_type:
1375 case dwarf::DW_TAG_subrange_type:
1376 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1377 case dwarf::DW_TAG_namespace:
1378 return dwarf::GIEK_TYPE;
1379 case dwarf::DW_TAG_subprogram:
1380 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1381 case dwarf::DW_TAG_variable:
1382 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1383 case dwarf::DW_TAG_enumerator:
1384 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1385 dwarf::GIEL_STATIC);
1387 return dwarf::GIEK_NONE;
1391 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1393 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1394 const MCSection *PSec =
1395 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1396 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1398 emitDebugPubSection(GnuStyle, PSec, "Names",
1399 &DwarfCompileUnit::getGlobalNames);
1402 void DwarfDebug::emitDebugPubSection(
1403 bool GnuStyle, const MCSection *PSec, StringRef Name,
1404 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1405 for (const auto &NU : CUMap) {
1406 DwarfCompileUnit *TheU = NU.second;
1408 const auto &Globals = (TheU->*Accessor)();
1410 if (Globals.empty())
1413 if (auto *Skeleton = TheU->getSkeleton())
1416 // Start the dwarf pubnames section.
1417 Asm->OutStreamer.SwitchSection(PSec);
1420 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1421 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1422 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1423 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1425 Asm->OutStreamer.EmitLabel(BeginLabel);
1427 Asm->OutStreamer.AddComment("DWARF Version");
1428 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1430 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1431 Asm->emitSectionOffset(TheU->getLabelBegin());
1433 Asm->OutStreamer.AddComment("Compilation Unit Length");
1434 Asm->EmitInt32(TheU->getLength());
1436 // Emit the pubnames for this compilation unit.
1437 for (const auto &GI : Globals) {
1438 const char *Name = GI.getKeyData();
1439 const DIE *Entity = GI.second;
1441 Asm->OutStreamer.AddComment("DIE offset");
1442 Asm->EmitInt32(Entity->getOffset());
1445 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1446 Asm->OutStreamer.AddComment(
1447 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1448 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1449 Asm->EmitInt8(Desc.toBits());
1452 Asm->OutStreamer.AddComment("External Name");
1453 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1456 Asm->OutStreamer.AddComment("End Mark");
1458 Asm->OutStreamer.EmitLabel(EndLabel);
1462 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1463 const MCSection *PSec =
1464 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1465 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1467 emitDebugPubSection(GnuStyle, PSec, "Types",
1468 &DwarfCompileUnit::getGlobalTypes);
1471 // Emit visible names into a debug str section.
1472 void DwarfDebug::emitDebugStr() {
1473 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1474 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1478 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1479 const DebugLocEntry &Entry) {
1480 auto Comment = Entry.getComments().begin();
1481 auto End = Entry.getComments().end();
1482 for (uint8_t Byte : Entry.getDWARFBytes())
1483 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1486 static void emitDebugLocValue(const AsmPrinter &AP,
1487 const DITypeIdentifierMap &TypeIdentifierMap,
1488 ByteStreamer &Streamer,
1489 const DebugLocEntry::Value &Value,
1490 unsigned PieceOffsetInBits) {
1491 DIVariable DV = Value.getVariable();
1492 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1493 AP.getDwarfDebug()->getDwarfVersion(),
1496 if (Value.isInt()) {
1497 MDType *T = DV.getType().resolve(TypeIdentifierMap);
1498 auto *B = dyn_cast<MDBasicType>(T);
1499 if (B && (B->getEncoding() == dwarf::DW_ATE_signed ||
1500 B->getEncoding() == dwarf::DW_ATE_signed_char))
1501 DwarfExpr.AddSignedConstant(Value.getInt());
1503 DwarfExpr.AddUnsignedConstant(Value.getInt());
1504 } else if (Value.isLocation()) {
1505 MachineLocation Loc = Value.getLoc();
1506 DIExpression Expr = Value.getExpression();
1507 if (!Expr || (Expr.getNumElements() == 0))
1509 AP.EmitDwarfRegOp(Streamer, Loc);
1511 // Complex address entry.
1512 if (Loc.getOffset()) {
1513 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1514 DwarfExpr.AddExpression(Expr.begin(), Expr.end(), PieceOffsetInBits);
1516 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1520 // else ... ignore constant fp. There is not any good way to
1521 // to represent them here in dwarf.
1526 void DebugLocEntry::finalize(const AsmPrinter &AP,
1527 const DITypeIdentifierMap &TypeIdentifierMap) {
1528 BufferByteStreamer Streamer(DWARFBytes, Comments);
1529 const DebugLocEntry::Value Value = Values[0];
1530 if (Value.isBitPiece()) {
1531 // Emit all pieces that belong to the same variable and range.
1532 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1533 return P.isBitPiece();
1534 }) && "all values are expected to be pieces");
1535 assert(std::is_sorted(Values.begin(), Values.end()) &&
1536 "pieces are expected to be sorted");
1538 unsigned Offset = 0;
1539 for (auto Piece : Values) {
1540 DIExpression Expr = Piece.getExpression();
1541 unsigned PieceOffset = Expr.getBitPieceOffset();
1542 unsigned PieceSize = Expr.getBitPieceSize();
1543 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1544 if (Offset < PieceOffset) {
1545 // The DWARF spec seriously mandates pieces with no locations for gaps.
1546 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1547 AP.getDwarfDebug()->getDwarfVersion(),
1549 Expr.AddOpPiece(PieceOffset-Offset, 0);
1550 Offset += PieceOffset-Offset;
1552 Offset += PieceSize;
1555 DIVariable Var = Piece.getVariable();
1556 unsigned VarSize = Var.getSizeInBits(TypeIdentifierMap);
1557 assert(PieceSize+PieceOffset <= VarSize
1558 && "piece is larger than or outside of variable");
1559 assert(PieceSize != VarSize
1560 && "piece covers entire variable");
1562 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Piece, PieceOffset);
1565 assert(Values.size() == 1 && "only pieces may have >1 value");
1566 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Value, 0);
1571 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
1572 Asm->OutStreamer.AddComment("Loc expr size");
1573 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
1574 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
1575 Asm->EmitLabelDifference(end, begin, 2);
1576 Asm->OutStreamer.EmitLabel(begin);
1578 APByteStreamer Streamer(*Asm);
1579 emitDebugLocEntry(Streamer, Entry);
1581 Asm->OutStreamer.EmitLabel(end);
1584 // Emit locations into the debug loc section.
1585 void DwarfDebug::emitDebugLoc() {
1586 // Start the dwarf loc section.
1587 Asm->OutStreamer.SwitchSection(
1588 Asm->getObjFileLowering().getDwarfLocSection());
1589 unsigned char Size = Asm->getDataLayout().getPointerSize();
1590 for (const auto &DebugLoc : DotDebugLocEntries) {
1591 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1592 const DwarfCompileUnit *CU = DebugLoc.CU;
1593 for (const auto &Entry : DebugLoc.List) {
1594 // Set up the range. This range is relative to the entry point of the
1595 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1596 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1597 if (auto *Base = CU->getBaseAddress()) {
1598 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
1599 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
1601 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
1602 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
1605 emitDebugLocEntryLocation(Entry);
1607 Asm->OutStreamer.EmitIntValue(0, Size);
1608 Asm->OutStreamer.EmitIntValue(0, Size);
1612 void DwarfDebug::emitDebugLocDWO() {
1613 Asm->OutStreamer.SwitchSection(
1614 Asm->getObjFileLowering().getDwarfLocDWOSection());
1615 for (const auto &DebugLoc : DotDebugLocEntries) {
1616 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1617 for (const auto &Entry : DebugLoc.List) {
1618 // Just always use start_length for now - at least that's one address
1619 // rather than two. We could get fancier and try to, say, reuse an
1620 // address we know we've emitted elsewhere (the start of the function?
1621 // The start of the CU or CU subrange that encloses this range?)
1622 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1623 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
1624 Asm->EmitULEB128(idx);
1625 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
1627 emitDebugLocEntryLocation(Entry);
1629 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1634 const MCSymbol *Start, *End;
1637 // Emit a debug aranges section, containing a CU lookup for any
1638 // address we can tie back to a CU.
1639 void DwarfDebug::emitDebugARanges() {
1640 // Provides a unique id per text section.
1641 MapVector<const MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1643 // Filter labels by section.
1644 for (const SymbolCU &SCU : ArangeLabels) {
1645 if (SCU.Sym->isInSection()) {
1646 // Make a note of this symbol and it's section.
1647 const MCSection *Section = &SCU.Sym->getSection();
1648 if (!Section->getKind().isMetadata())
1649 SectionMap[Section].push_back(SCU);
1651 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1652 // appear in the output. This sucks as we rely on sections to build
1653 // arange spans. We can do it without, but it's icky.
1654 SectionMap[nullptr].push_back(SCU);
1658 // Add terminating symbols for each section.
1659 for (const auto &I : SectionMap) {
1660 const MCSection *Section = I.first;
1661 MCSymbol *Sym = nullptr;
1664 Sym = Asm->OutStreamer.endSection(Section);
1666 // Insert a final terminator.
1667 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1670 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1672 for (auto &I : SectionMap) {
1673 const MCSection *Section = I.first;
1674 SmallVector<SymbolCU, 8> &List = I.second;
1675 if (List.size() < 2)
1678 // If we have no section (e.g. common), just write out
1679 // individual spans for each symbol.
1681 for (const SymbolCU &Cur : List) {
1683 Span.Start = Cur.Sym;
1686 Spans[Cur.CU].push_back(Span);
1691 // Sort the symbols by offset within the section.
1692 std::sort(List.begin(), List.end(),
1693 [&](const SymbolCU &A, const SymbolCU &B) {
1694 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
1695 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
1697 // Symbols with no order assigned should be placed at the end.
1698 // (e.g. section end labels)
1706 // Build spans between each label.
1707 const MCSymbol *StartSym = List[0].Sym;
1708 for (size_t n = 1, e = List.size(); n < e; n++) {
1709 const SymbolCU &Prev = List[n - 1];
1710 const SymbolCU &Cur = List[n];
1712 // Try and build the longest span we can within the same CU.
1713 if (Cur.CU != Prev.CU) {
1715 Span.Start = StartSym;
1717 Spans[Prev.CU].push_back(Span);
1723 // Start the dwarf aranges section.
1724 Asm->OutStreamer.SwitchSection(
1725 Asm->getObjFileLowering().getDwarfARangesSection());
1727 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1729 // Build a list of CUs used.
1730 std::vector<DwarfCompileUnit *> CUs;
1731 for (const auto &it : Spans) {
1732 DwarfCompileUnit *CU = it.first;
1736 // Sort the CU list (again, to ensure consistent output order).
1737 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1738 return A->getUniqueID() < B->getUniqueID();
1741 // Emit an arange table for each CU we used.
1742 for (DwarfCompileUnit *CU : CUs) {
1743 std::vector<ArangeSpan> &List = Spans[CU];
1745 // Describe the skeleton CU's offset and length, not the dwo file's.
1746 if (auto *Skel = CU->getSkeleton())
1749 // Emit size of content not including length itself.
1750 unsigned ContentSize =
1751 sizeof(int16_t) + // DWARF ARange version number
1752 sizeof(int32_t) + // Offset of CU in the .debug_info section
1753 sizeof(int8_t) + // Pointer Size (in bytes)
1754 sizeof(int8_t); // Segment Size (in bytes)
1756 unsigned TupleSize = PtrSize * 2;
1758 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1760 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1762 ContentSize += Padding;
1763 ContentSize += (List.size() + 1) * TupleSize;
1765 // For each compile unit, write the list of spans it covers.
1766 Asm->OutStreamer.AddComment("Length of ARange Set");
1767 Asm->EmitInt32(ContentSize);
1768 Asm->OutStreamer.AddComment("DWARF Arange version number");
1769 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1770 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
1771 Asm->emitSectionOffset(CU->getLabelBegin());
1772 Asm->OutStreamer.AddComment("Address Size (in bytes)");
1773 Asm->EmitInt8(PtrSize);
1774 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
1777 Asm->OutStreamer.EmitFill(Padding, 0xff);
1779 for (const ArangeSpan &Span : List) {
1780 Asm->EmitLabelReference(Span.Start, PtrSize);
1782 // Calculate the size as being from the span start to it's end.
1784 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1786 // For symbols without an end marker (e.g. common), we
1787 // write a single arange entry containing just that one symbol.
1788 uint64_t Size = SymSize[Span.Start];
1792 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
1796 Asm->OutStreamer.AddComment("ARange terminator");
1797 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1798 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1802 // Emit visible names into a debug ranges section.
1803 void DwarfDebug::emitDebugRanges() {
1804 // Start the dwarf ranges section.
1805 Asm->OutStreamer.SwitchSection(
1806 Asm->getObjFileLowering().getDwarfRangesSection());
1808 // Size for our labels.
1809 unsigned char Size = Asm->getDataLayout().getPointerSize();
1811 // Grab the specific ranges for the compile units in the module.
1812 for (const auto &I : CUMap) {
1813 DwarfCompileUnit *TheCU = I.second;
1815 if (auto *Skel = TheCU->getSkeleton())
1818 // Iterate over the misc ranges for the compile units in the module.
1819 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1820 // Emit our symbol so we can find the beginning of the range.
1821 Asm->OutStreamer.EmitLabel(List.getSym());
1823 for (const RangeSpan &Range : List.getRanges()) {
1824 const MCSymbol *Begin = Range.getStart();
1825 const MCSymbol *End = Range.getEnd();
1826 assert(Begin && "Range without a begin symbol?");
1827 assert(End && "Range without an end symbol?");
1828 if (auto *Base = TheCU->getBaseAddress()) {
1829 Asm->EmitLabelDifference(Begin, Base, Size);
1830 Asm->EmitLabelDifference(End, Base, Size);
1832 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
1833 Asm->OutStreamer.EmitSymbolValue(End, Size);
1837 // And terminate the list with two 0 values.
1838 Asm->OutStreamer.EmitIntValue(0, Size);
1839 Asm->OutStreamer.EmitIntValue(0, Size);
1844 // DWARF5 Experimental Separate Dwarf emitters.
1846 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1847 std::unique_ptr<DwarfUnit> NewU) {
1848 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1849 U.getCUNode().getSplitDebugFilename());
1851 if (!CompilationDir.empty())
1852 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1854 addGnuPubAttributes(*NewU, Die);
1856 SkeletonHolder.addUnit(std::move(NewU));
1859 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1860 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1861 // DW_AT_addr_base, DW_AT_ranges_base.
1862 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1864 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1865 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1866 DwarfCompileUnit &NewCU = *OwnedUnit;
1867 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1869 NewCU.initStmtList();
1871 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1876 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1877 // compile units that would normally be in debug_info.
1878 void DwarfDebug::emitDebugInfoDWO() {
1879 assert(useSplitDwarf() && "No split dwarf debug info?");
1880 // Don't emit relocations into the dwo file.
1881 InfoHolder.emitUnits(/* UseOffsets */ true);
1884 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1885 // abbreviations for the .debug_info.dwo section.
1886 void DwarfDebug::emitDebugAbbrevDWO() {
1887 assert(useSplitDwarf() && "No split dwarf?");
1888 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1891 void DwarfDebug::emitDebugLineDWO() {
1892 assert(useSplitDwarf() && "No split dwarf?");
1893 Asm->OutStreamer.SwitchSection(
1894 Asm->getObjFileLowering().getDwarfLineDWOSection());
1895 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
1898 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1899 // string section and is identical in format to traditional .debug_str
1901 void DwarfDebug::emitDebugStrDWO() {
1902 assert(useSplitDwarf() && "No split dwarf?");
1903 const MCSection *OffSec =
1904 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1905 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1909 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1910 if (!useSplitDwarf())
1913 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
1914 return &SplitTypeUnitFileTable;
1917 static uint64_t makeTypeSignature(StringRef Identifier) {
1919 Hash.update(Identifier);
1920 // ... take the least significant 8 bytes and return those. Our MD5
1921 // implementation always returns its results in little endian, swap bytes
1923 MD5::MD5Result Result;
1925 return support::endian::read64le(Result + 8);
1928 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1929 StringRef Identifier, DIE &RefDie,
1930 DICompositeType CTy) {
1931 // Fast path if we're building some type units and one has already used the
1932 // address pool we know we're going to throw away all this work anyway, so
1933 // don't bother building dependent types.
1934 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1937 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1939 CU.addDIETypeSignature(RefDie, *TU);
1943 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1944 AddrPool.resetUsedFlag();
1946 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1947 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1948 this, &InfoHolder, getDwoLineTable(CU));
1949 DwarfTypeUnit &NewTU = *OwnedUnit;
1950 DIE &UnitDie = NewTU.getUnitDie();
1952 TypeUnitsUnderConstruction.push_back(
1953 std::make_pair(std::move(OwnedUnit), CTy));
1955 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1958 uint64_t Signature = makeTypeSignature(Identifier);
1959 NewTU.setTypeSignature(Signature);
1961 if (useSplitDwarf())
1962 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1964 CU.applyStmtList(UnitDie);
1966 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1969 NewTU.setType(NewTU.createTypeDIE(CTy));
1972 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1973 TypeUnitsUnderConstruction.clear();
1975 // Types referencing entries in the address table cannot be placed in type
1977 if (AddrPool.hasBeenUsed()) {
1979 // Remove all the types built while building this type.
1980 // This is pessimistic as some of these types might not be dependent on
1981 // the type that used an address.
1982 for (const auto &TU : TypeUnitsToAdd)
1983 DwarfTypeUnits.erase(TU.second);
1985 // Construct this type in the CU directly.
1986 // This is inefficient because all the dependent types will be rebuilt
1987 // from scratch, including building them in type units, discovering that
1988 // they depend on addresses, throwing them out and rebuilding them.
1989 CU.constructTypeDIE(RefDie, CTy);
1993 // If the type wasn't dependent on fission addresses, finish adding the type
1994 // and all its dependent types.
1995 for (auto &TU : TypeUnitsToAdd)
1996 InfoHolder.addUnit(std::move(TU.first));
1998 CU.addDIETypeSignature(RefDie, NewTU);
2001 // Accelerator table mutators - add each name along with its companion
2002 // DIE to the proper table while ensuring that the name that we're going
2003 // to reference is in the string table. We do this since the names we
2004 // add may not only be identical to the names in the DIE.
2005 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2006 if (!useDwarfAccelTables())
2008 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2012 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2013 if (!useDwarfAccelTables())
2015 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2019 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2020 if (!useDwarfAccelTables())
2022 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2026 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2027 if (!useDwarfAccelTables())
2029 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),