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/Target/TargetFrameLowering.h"
49 #include "llvm/Target/TargetLoweringObjectFile.h"
50 #include "llvm/Target/TargetMachine.h"
51 #include "llvm/Target/TargetOptions.h"
52 #include "llvm/Target/TargetRegisterInfo.h"
53 #include "llvm/Target/TargetSubtargetInfo.h"
56 #define DEBUG_TYPE "dwarfdebug"
59 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
60 cl::desc("Disable debug info printing"));
62 static cl::opt<bool> UnknownLocations(
63 "use-unknown-locations", cl::Hidden,
64 cl::desc("Make an absence of debug location information explicit."),
68 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
69 cl::desc("Generate GNU-style pubnames and pubtypes"),
72 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
74 cl::desc("Generate dwarf aranges"),
78 enum DefaultOnOff { Default, Enable, Disable };
81 static cl::opt<DefaultOnOff>
82 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
83 cl::desc("Output prototype dwarf accelerator tables."),
84 cl::values(clEnumVal(Default, "Default for platform"),
85 clEnumVal(Enable, "Enabled"),
86 clEnumVal(Disable, "Disabled"), clEnumValEnd),
89 static cl::opt<DefaultOnOff>
90 SplitDwarf("split-dwarf", cl::Hidden,
91 cl::desc("Output DWARF5 split debug info."),
92 cl::values(clEnumVal(Default, "Default for platform"),
93 clEnumVal(Enable, "Enabled"),
94 clEnumVal(Disable, "Disabled"), clEnumValEnd),
97 static cl::opt<DefaultOnOff>
98 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
99 cl::desc("Generate DWARF pubnames and pubtypes sections"),
100 cl::values(clEnumVal(Default, "Default for platform"),
101 clEnumVal(Enable, "Enabled"),
102 clEnumVal(Disable, "Disabled"), clEnumValEnd),
105 static const char *const DWARFGroupName = "DWARF Emission";
106 static const char *const DbgTimerName = "DWARF Debug Writer";
108 void DebugLocDwarfExpression::EmitOp(uint8_t Op, const char *Comment) {
110 Op, Comment ? Twine(Comment) + " " + dwarf::OperationEncodingString(Op)
111 : dwarf::OperationEncodingString(Op));
114 void DebugLocDwarfExpression::EmitSigned(int64_t Value) {
115 BS.EmitSLEB128(Value, Twine(Value));
118 void DebugLocDwarfExpression::EmitUnsigned(uint64_t Value) {
119 BS.EmitULEB128(Value, Twine(Value));
122 bool DebugLocDwarfExpression::isFrameRegister(unsigned MachineReg) {
123 // This information is not available while emitting .debug_loc entries.
127 //===----------------------------------------------------------------------===//
129 /// resolve - Look in the DwarfDebug map for the MDNode that
130 /// corresponds to the reference.
131 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
132 return DD->resolve(Ref);
135 bool DbgVariable::isBlockByrefVariable() const {
136 assert(Var.isVariable() && "Invalid complex DbgVariable!");
137 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
140 DIType DbgVariable::getType() const {
141 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
142 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
143 // addresses instead.
144 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
145 /* Byref variables, in Blocks, are declared by the programmer as
146 "SomeType VarName;", but the compiler creates a
147 __Block_byref_x_VarName struct, and gives the variable VarName
148 either the struct, or a pointer to the struct, as its type. This
149 is necessary for various behind-the-scenes things the compiler
150 needs to do with by-reference variables in blocks.
152 However, as far as the original *programmer* is concerned, the
153 variable should still have type 'SomeType', as originally declared.
155 The following function dives into the __Block_byref_x_VarName
156 struct to find the original type of the variable. This will be
157 passed back to the code generating the type for the Debug
158 Information Entry for the variable 'VarName'. 'VarName' will then
159 have the original type 'SomeType' in its debug information.
161 The original type 'SomeType' will be the type of the field named
162 'VarName' inside the __Block_byref_x_VarName struct.
164 NOTE: In order for this to not completely fail on the debugger
165 side, the Debug Information Entry for the variable VarName needs to
166 have a DW_AT_location that tells the debugger how to unwind through
167 the pointers and __Block_byref_x_VarName struct to find the actual
168 value of the variable. The function addBlockByrefType does this. */
170 uint16_t tag = Ty.getTag();
172 if (tag == dwarf::DW_TAG_pointer_type)
173 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
175 DIArray Elements = DICompositeType(subType).getElements();
176 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
177 DIDerivedType DT(Elements.getElement(i));
178 if (getName() == DT.getName())
179 return (resolve(DT.getTypeDerivedFrom()));
185 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
186 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
187 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
188 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
190 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
191 : Asm(A), MMI(Asm->MMI), PrevLabel(nullptr),
192 InfoHolder(A, "info_string", DIEValueAllocator),
193 UsedNonDefaultText(false),
194 SkeletonHolder(A, "skel_string", DIEValueAllocator),
195 IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
196 IsPS4(Triple(A->getTargetTriple()).isPS4()),
197 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
198 dwarf::DW_FORM_data4)),
199 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
200 dwarf::DW_FORM_data4)),
201 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
202 dwarf::DW_FORM_data4)),
203 AccelTypes(TypeAtoms) {
208 // Turn on accelerator tables for Darwin by default, pubnames by
209 // default for non-Darwin/PS4, and handle split dwarf.
210 if (DwarfAccelTables == Default)
211 HasDwarfAccelTables = IsDarwin;
213 HasDwarfAccelTables = DwarfAccelTables == Enable;
215 if (SplitDwarf == Default)
216 HasSplitDwarf = false;
218 HasSplitDwarf = SplitDwarf == Enable;
220 if (DwarfPubSections == Default)
221 HasDwarfPubSections = !IsDarwin && !IsPS4;
223 HasDwarfPubSections = DwarfPubSections == Enable;
225 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
226 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
227 : MMI->getModule()->getDwarfVersion();
229 // Darwin and PS4 use the standard TLS opcode (defined in DWARF 3).
230 // Everybody else uses GNU's.
231 UseGNUTLSOpcode = !(IsDarwin || IsPS4) || DwarfVersion < 3;
233 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
236 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
241 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
242 DwarfDebug::~DwarfDebug() { }
244 static bool isObjCClass(StringRef Name) {
245 return Name.startswith("+") || Name.startswith("-");
248 static bool hasObjCCategory(StringRef Name) {
249 if (!isObjCClass(Name))
252 return Name.find(") ") != StringRef::npos;
255 static void getObjCClassCategory(StringRef In, StringRef &Class,
256 StringRef &Category) {
257 if (!hasObjCCategory(In)) {
258 Class = In.slice(In.find('[') + 1, In.find(' '));
263 Class = In.slice(In.find('[') + 1, In.find('('));
264 Category = In.slice(In.find('[') + 1, In.find(' '));
268 static StringRef getObjCMethodName(StringRef In) {
269 return In.slice(In.find(' ') + 1, In.find(']'));
272 // Add the various names to the Dwarf accelerator table names.
273 // TODO: Determine whether or not we should add names for programs
274 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
275 // is only slightly different than the lookup of non-standard ObjC names.
276 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
277 if (!SP.isDefinition())
279 addAccelName(SP.getName(), Die);
281 // If the linkage name is different than the name, go ahead and output
282 // that as well into the name table.
283 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
284 addAccelName(SP.getLinkageName(), Die);
286 // If this is an Objective-C selector name add it to the ObjC accelerator
288 if (isObjCClass(SP.getName())) {
289 StringRef Class, Category;
290 getObjCClassCategory(SP.getName(), Class, Category);
291 addAccelObjC(Class, Die);
293 addAccelObjC(Category, Die);
294 // Also add the base method name to the name table.
295 addAccelName(getObjCMethodName(SP.getName()), Die);
299 /// isSubprogramContext - Return true if Context is either a subprogram
300 /// or another context nested inside a subprogram.
301 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
304 DIDescriptor D(Context);
305 if (D.isSubprogram())
308 return isSubprogramContext(resolve(DIType(Context).getContext()));
312 /// 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(N);
423 assert(Module.Verify());
424 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
425 D->addChild(TheCU.constructImportedEntityDIE(Module));
428 // Emit all Dwarf sections that should come prior to the content. Create
429 // global DIEs and emit initial debug info sections. This is invoked by
430 // the target AsmPrinter.
431 void DwarfDebug::beginModule() {
432 if (DisableDebugInfoPrinting)
435 const Module *M = MMI->getModule();
437 FunctionDIs = makeSubprogramMap(*M);
439 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
442 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
444 SingleCU = CU_Nodes->getNumOperands() == 1;
446 for (MDNode *N : CU_Nodes->operands()) {
447 DICompileUnit CUNode(N);
448 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
449 DIArray ImportedEntities = CUNode.getImportedEntities();
450 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
451 ScopesWithImportedEntities.push_back(std::make_pair(
452 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
453 ImportedEntities.getElement(i)));
454 // Stable sort to preserve the order of appearance of imported entities.
455 // This is to avoid out-of-order processing of interdependent declarations
456 // within the same scope, e.g. { namespace A = base; namespace B = A; }
457 std::stable_sort(ScopesWithImportedEntities.begin(),
458 ScopesWithImportedEntities.end(), less_first());
459 DIArray GVs = CUNode.getGlobalVariables();
460 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
461 CU.getOrCreateGlobalVariableDIE(DIGlobalVariable(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(EnumTypes.getElement(i));
468 // The enum types array by design contains pointers to
469 // MDNodes rather than DIRefs. Unique them here.
470 DIType UniqueTy(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(RetainedTypes.getElement(i));
476 // The retained types array by design contains pointers to
477 // MDNodes rather than DIRefs. Unique them here.
478 DIType UniqueTy(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(DISubprogram(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(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(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(ScopeNode));
710 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
711 const MDNode *ScopeNode) {
712 DIVariable Cleansed = DV;
713 if (getExistingAbstractVariable(DV, Cleansed))
716 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
717 createAbstractVariable(Cleansed, Scope);
720 // Collect variable information from side table maintained by MMI.
721 void DwarfDebug::collectVariableInfoFromMMITable(
722 SmallPtrSetImpl<const MDNode *> &Processed) {
723 for (const auto &VI : MMI->getVariableDbgInfo()) {
726 Processed.insert(VI.Var);
727 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
729 // If variable scope is not found then skip this variable.
733 DIVariable DV(VI.Var);
734 DIExpression Expr(VI.Expr);
735 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
736 auto RegVar = make_unique<DbgVariable>(DV, Expr, this, VI.Slot);
737 if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
738 ConcreteVariables.push_back(std::move(RegVar));
742 // Get .debug_loc entry for the instruction range starting at MI.
743 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
744 const MDNode *Expr = MI->getDebugExpression();
745 const MDNode *Var = MI->getDebugVariable();
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(Var, Expr, MLoc);
758 if (MI->getOperand(0).isImm())
759 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getImm());
760 if (MI->getOperand(0).isFPImm())
761 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getFPImm());
762 if (MI->getOperand(0).isCImm())
763 return DebugLocEntry::Value(Var, 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(DIExpression P1, 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 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();
869 auto PrevEntry = std::next(CurEntry);
870 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
874 dbgs() << CurEntry->getValues().size() << " Values:\n";
875 for (auto Value : CurEntry->getValues()) {
876 Value.getVariable()->dump();
877 Value.getExpression()->dump();
885 // Find variables for each lexical scope.
887 DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU, DISubprogram SP,
888 SmallPtrSetImpl<const MDNode *> &Processed) {
889 // Grab the variable info that was squirreled away in the MMI side-table.
890 collectVariableInfoFromMMITable(Processed);
892 for (const auto &I : DbgValues) {
893 DIVariable DV(I.first);
894 if (Processed.count(DV))
897 // Instruction ranges, specifying where DV is accessible.
898 const auto &Ranges = I.second;
902 LexicalScope *Scope = nullptr;
903 if (MDNode *IA = DV.getInlinedAt())
904 Scope = LScopes.findInlinedScope(DV.getContext(), IA);
906 Scope = LScopes.findLexicalScope(DV.getContext());
907 // If variable scope is not found then skip this variable.
911 Processed.insert(DV);
912 const MachineInstr *MInsn = Ranges.front().first;
913 assert(MInsn->isDebugValue() && "History must begin with debug value");
914 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
915 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
916 DbgVariable *RegVar = ConcreteVariables.back().get();
917 InfoHolder.addScopeVariable(Scope, RegVar);
919 // Check if the first DBG_VALUE is valid for the rest of the function.
920 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
923 // Handle multiple DBG_VALUE instructions describing one variable.
924 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
926 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
927 DebugLocList &LocList = DotDebugLocEntries.back();
929 LocList.Label = Asm->createTempSymbol("debug_loc");
931 // Build the location list for this variable.
932 buildLocationList(LocList.List, Ranges);
933 // Finalize the entry by lowering it into a DWARF bytestream.
934 for (auto &Entry : LocList.List)
935 Entry.finalize(*Asm, TypeIdentifierMap);
938 // Collect info for variables that were optimized out.
939 DIArray Variables = SP.getVariables();
940 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
941 DIVariable DV(Variables.getElement(i));
942 assert(DV.isVariable());
943 if (!Processed.insert(DV).second)
945 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
946 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
948 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, NoExpr, this));
949 InfoHolder.addScopeVariable(Scope, ConcreteVariables.back().get());
954 // Return Label preceding the instruction.
955 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
956 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
957 assert(Label && "Didn't insert label before instruction");
961 // Return Label immediately following the instruction.
962 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
963 return LabelsAfterInsn.lookup(MI);
966 // Process beginning of an instruction.
967 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
968 assert(CurMI == nullptr);
970 // Check if source location changes, but ignore DBG_VALUE locations.
971 if (!MI->isDebugValue()) {
972 DebugLoc DL = MI->getDebugLoc();
973 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
976 if (DL == PrologEndLoc) {
977 Flags |= DWARF2_FLAG_PROLOGUE_END;
978 PrologEndLoc = DebugLoc();
979 Flags |= DWARF2_FLAG_IS_STMT;
982 Asm->OutStreamer.getContext().getCurrentDwarfLoc().getLine())
983 Flags |= DWARF2_FLAG_IS_STMT;
985 if (!DL.isUnknown()) {
986 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
987 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
989 recordSourceLine(0, 0, nullptr, 0);
993 // Insert labels where requested.
994 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
995 LabelsBeforeInsn.find(MI);
998 if (I == LabelsBeforeInsn.end())
1001 // Label already assigned.
1006 PrevLabel = MMI->getContext().CreateTempSymbol();
1007 Asm->OutStreamer.EmitLabel(PrevLabel);
1009 I->second = PrevLabel;
1012 // Process end of an instruction.
1013 void DwarfDebug::endInstruction() {
1014 assert(CurMI != nullptr);
1015 // Don't create a new label after DBG_VALUE instructions.
1016 // They don't generate code.
1017 if (!CurMI->isDebugValue())
1018 PrevLabel = nullptr;
1020 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1021 LabelsAfterInsn.find(CurMI);
1025 if (I == LabelsAfterInsn.end())
1028 // Label already assigned.
1032 // We need a label after this instruction.
1034 PrevLabel = MMI->getContext().CreateTempSymbol();
1035 Asm->OutStreamer.EmitLabel(PrevLabel);
1037 I->second = PrevLabel;
1040 // Each LexicalScope has first instruction and last instruction to mark
1041 // beginning and end of a scope respectively. Create an inverse map that list
1042 // scopes starts (and ends) with an instruction. One instruction may start (or
1043 // end) multiple scopes. Ignore scopes that are not reachable.
1044 void DwarfDebug::identifyScopeMarkers() {
1045 SmallVector<LexicalScope *, 4> WorkList;
1046 WorkList.push_back(LScopes.getCurrentFunctionScope());
1047 while (!WorkList.empty()) {
1048 LexicalScope *S = WorkList.pop_back_val();
1050 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1051 if (!Children.empty())
1052 WorkList.append(Children.begin(), Children.end());
1054 if (S->isAbstractScope())
1057 for (const InsnRange &R : S->getRanges()) {
1058 assert(R.first && "InsnRange does not have first instruction!");
1059 assert(R.second && "InsnRange does not have second instruction!");
1060 requestLabelBeforeInsn(R.first);
1061 requestLabelAfterInsn(R.second);
1066 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1067 // First known non-DBG_VALUE and non-frame setup location marks
1068 // the beginning of the function body.
1069 for (const auto &MBB : *MF)
1070 for (const auto &MI : MBB)
1071 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1072 !MI.getDebugLoc().isUnknown()) {
1073 // Did the target forget to set the FrameSetup flag for CFI insns?
1074 assert(!MI.isCFIInstruction() &&
1075 "First non-frame-setup instruction is a CFI instruction.");
1076 return MI.getDebugLoc();
1081 // Gather pre-function debug information. Assumes being called immediately
1082 // after the function entry point has been emitted.
1083 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1086 // If there's no debug info for the function we're not going to do anything.
1087 if (!MMI->hasDebugInfo())
1090 auto DI = FunctionDIs.find(MF->getFunction());
1091 if (DI == FunctionDIs.end())
1094 // Grab the lexical scopes for the function, if we don't have any of those
1095 // then we're not going to be able to do anything.
1096 LScopes.initialize(*MF);
1097 if (LScopes.empty())
1100 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1102 // Make sure that each lexical scope will have a begin/end label.
1103 identifyScopeMarkers();
1105 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1106 // belongs to so that we add to the correct per-cu line table in the
1108 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1109 // FnScope->getScopeNode() and DI->second should represent the same function,
1110 // though they may not be the same MDNode due to inline functions merged in
1111 // LTO where the debug info metadata still differs (either due to distinct
1112 // written differences - two versions of a linkonce_odr function
1113 // written/copied into two separate files, or some sub-optimal metadata that
1114 // isn't structurally identical (see: file path/name info from clang, which
1115 // includes the directory of the cpp file being built, even when the file name
1116 // is absolute (such as an <> lookup header)))
1117 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1118 assert(TheCU && "Unable to find compile unit!");
1119 if (Asm->OutStreamer.hasRawTextSupport())
1120 // Use a single line table if we are generating assembly.
1121 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1123 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1125 // Calculate history for local variables.
1126 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1129 // Request labels for the full history.
1130 for (const auto &I : DbgValues) {
1131 const auto &Ranges = I.second;
1135 // The first mention of a function argument gets the CurrentFnBegin
1136 // label, so arguments are visible when breaking at function entry.
1137 DIVariable DIVar(Ranges.front().first->getDebugVariable());
1138 if (DIVar.isVariable() && DIVar.getTag() == dwarf::DW_TAG_arg_variable &&
1139 getDISubprogram(DIVar.getContext()).describes(MF->getFunction())) {
1140 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1141 if (Ranges.front().first->getDebugExpression().isBitPiece()) {
1142 // Mark all non-overlapping initial pieces.
1143 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1144 DIExpression Piece = I->first->getDebugExpression();
1145 if (std::all_of(Ranges.begin(), I,
1146 [&](DbgValueHistoryMap::InstrRange Pred) {
1147 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1149 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1156 for (const auto &Range : Ranges) {
1157 requestLabelBeforeInsn(Range.first);
1159 requestLabelAfterInsn(Range.second);
1163 PrevInstLoc = DebugLoc();
1164 PrevLabel = Asm->getFunctionBegin();
1166 // Record beginning of function.
1167 PrologEndLoc = findPrologueEndLoc(MF);
1168 if (!PrologEndLoc.isUnknown()) {
1169 DebugLoc FnStartDL =
1170 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
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 recordSourceLine(FnStartDL.getLine(), FnStartDL.getCol(),
1175 FnStartDL.getScope(MF->getFunction()->getContext()),
1176 DWARF2_FLAG_IS_STMT);
1180 // Gather and emit post-function debug information.
1181 void DwarfDebug::endFunction(const MachineFunction *MF) {
1182 assert(CurFn == MF &&
1183 "endFunction should be called with the same function as beginFunction");
1185 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1186 !FunctionDIs.count(MF->getFunction())) {
1187 // If we don't have a lexical scope for this function then there will
1188 // be a hole in the range information. Keep note of this by setting the
1189 // previously used section to nullptr.
1195 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1196 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1198 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1199 DISubprogram SP(FnScope->getScopeNode());
1200 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1202 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1203 collectVariableInfo(TheCU, SP, ProcessedVars);
1205 // Add the range of this function to the list of ranges for the CU.
1206 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1208 // Under -gmlt, skip building the subprogram if there are no inlined
1209 // subroutines inside it.
1210 if (TheCU.getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly &&
1211 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1212 assert(InfoHolder.getScopeVariables().empty());
1213 assert(DbgValues.empty());
1214 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1215 // by a -gmlt CU. Add a test and remove this assertion.
1216 assert(AbstractVariables.empty());
1217 LabelsBeforeInsn.clear();
1218 LabelsAfterInsn.clear();
1219 PrevLabel = nullptr;
1225 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1227 // Construct abstract scopes.
1228 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1229 DISubprogram SP(AScope->getScopeNode());
1230 assert(SP.isSubprogram());
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(Variables.getElement(i));
1235 assert(DV && DV.isVariable());
1236 if (!ProcessedVars.insert(DV).second)
1238 ensureAbstractVariableIsCreated(DV, DV.getContext());
1239 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1240 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1242 constructAbstractSubprogramScopeDIE(AScope);
1245 TheCU.constructSubprogramScopeDIE(FnScope);
1246 if (auto *SkelCU = TheCU.getSkeleton())
1247 if (!LScopes.getAbstractScopesList().empty())
1248 SkelCU->constructSubprogramScopeDIE(FnScope);
1251 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1252 // DbgVariables except those that are also in AbstractVariables (since they
1253 // can be used cross-function)
1254 InfoHolder.getScopeVariables().clear();
1256 LabelsBeforeInsn.clear();
1257 LabelsAfterInsn.clear();
1258 PrevLabel = nullptr;
1262 // Register a source line with debug info. Returns the unique label that was
1263 // emitted and which provides correspondence to the source line list.
1264 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1269 unsigned Discriminator = 0;
1270 if (DIScope Scope = DIScope(S)) {
1271 assert(Scope.isScope());
1272 Fn = Scope.getFilename();
1273 Dir = Scope.getDirectory();
1274 if (Scope.isLexicalBlockFile())
1275 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1277 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1278 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1279 .getOrCreateSourceID(Fn, Dir);
1281 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1285 //===----------------------------------------------------------------------===//
1287 //===----------------------------------------------------------------------===//
1289 // Emit the debug info section.
1290 void DwarfDebug::emitDebugInfo() {
1291 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1292 Holder.emitUnits(/* UseOffsets */ false);
1295 // Emit the abbreviation section.
1296 void DwarfDebug::emitAbbreviations() {
1297 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1299 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1302 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1303 StringRef TableName) {
1304 Accel.FinalizeTable(Asm, TableName);
1305 Asm->OutStreamer.SwitchSection(Section);
1307 // Emit the full data.
1308 Accel.emit(Asm, Section->getBeginSymbol(), this);
1311 // Emit visible names into a hashed accelerator table section.
1312 void DwarfDebug::emitAccelNames() {
1313 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1317 // Emit objective C classes and categories into a hashed accelerator table
1319 void DwarfDebug::emitAccelObjC() {
1320 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1324 // Emit namespace dies into a hashed accelerator table.
1325 void DwarfDebug::emitAccelNamespaces() {
1326 emitAccel(AccelNamespace,
1327 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1331 // Emit type dies into a hashed accelerator table.
1332 void DwarfDebug::emitAccelTypes() {
1333 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1337 // Public name handling.
1338 // The format for the various pubnames:
1340 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1341 // for the DIE that is named.
1343 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1344 // into the CU and the index value is computed according to the type of value
1345 // for the DIE that is named.
1347 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1348 // it's the offset within the debug_info/debug_types dwo section, however, the
1349 // reference in the pubname header doesn't change.
1351 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1352 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1354 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1356 // We could have a specification DIE that has our most of our knowledge,
1357 // look for that now.
1358 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1360 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1361 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1362 Linkage = dwarf::GIEL_EXTERNAL;
1363 } else if (Die->findAttribute(dwarf::DW_AT_external))
1364 Linkage = dwarf::GIEL_EXTERNAL;
1366 switch (Die->getTag()) {
1367 case dwarf::DW_TAG_class_type:
1368 case dwarf::DW_TAG_structure_type:
1369 case dwarf::DW_TAG_union_type:
1370 case dwarf::DW_TAG_enumeration_type:
1371 return dwarf::PubIndexEntryDescriptor(
1372 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1373 ? dwarf::GIEL_STATIC
1374 : dwarf::GIEL_EXTERNAL);
1375 case dwarf::DW_TAG_typedef:
1376 case dwarf::DW_TAG_base_type:
1377 case dwarf::DW_TAG_subrange_type:
1378 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1379 case dwarf::DW_TAG_namespace:
1380 return dwarf::GIEK_TYPE;
1381 case dwarf::DW_TAG_subprogram:
1382 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1383 case dwarf::DW_TAG_variable:
1384 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1385 case dwarf::DW_TAG_enumerator:
1386 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1387 dwarf::GIEL_STATIC);
1389 return dwarf::GIEK_NONE;
1393 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1395 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1396 const MCSection *PSec =
1397 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1398 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1400 emitDebugPubSection(GnuStyle, PSec, "Names",
1401 &DwarfCompileUnit::getGlobalNames);
1404 void DwarfDebug::emitDebugPubSection(
1405 bool GnuStyle, const MCSection *PSec, StringRef Name,
1406 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1407 for (const auto &NU : CUMap) {
1408 DwarfCompileUnit *TheU = NU.second;
1410 const auto &Globals = (TheU->*Accessor)();
1412 if (Globals.empty())
1415 if (auto *Skeleton = TheU->getSkeleton())
1418 // Start the dwarf pubnames section.
1419 Asm->OutStreamer.SwitchSection(PSec);
1422 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1423 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1424 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1425 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1427 Asm->OutStreamer.EmitLabel(BeginLabel);
1429 Asm->OutStreamer.AddComment("DWARF Version");
1430 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1432 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1433 Asm->emitSectionOffset(TheU->getLabelBegin());
1435 Asm->OutStreamer.AddComment("Compilation Unit Length");
1436 Asm->EmitInt32(TheU->getLength());
1438 // Emit the pubnames for this compilation unit.
1439 for (const auto &GI : Globals) {
1440 const char *Name = GI.getKeyData();
1441 const DIE *Entity = GI.second;
1443 Asm->OutStreamer.AddComment("DIE offset");
1444 Asm->EmitInt32(Entity->getOffset());
1447 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1448 Asm->OutStreamer.AddComment(
1449 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1450 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1451 Asm->EmitInt8(Desc.toBits());
1454 Asm->OutStreamer.AddComment("External Name");
1455 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1458 Asm->OutStreamer.AddComment("End Mark");
1460 Asm->OutStreamer.EmitLabel(EndLabel);
1464 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1465 const MCSection *PSec =
1466 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1467 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1469 emitDebugPubSection(GnuStyle, PSec, "Types",
1470 &DwarfCompileUnit::getGlobalTypes);
1473 // Emit visible names into a debug str section.
1474 void DwarfDebug::emitDebugStr() {
1475 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1476 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1480 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1481 const DebugLocEntry &Entry) {
1482 auto Comment = Entry.getComments().begin();
1483 auto End = Entry.getComments().end();
1484 for (uint8_t Byte : Entry.getDWARFBytes())
1485 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1488 static void emitDebugLocValue(const AsmPrinter &AP,
1489 const DITypeIdentifierMap &TypeIdentifierMap,
1490 ByteStreamer &Streamer,
1491 const DebugLocEntry::Value &Value,
1492 unsigned PieceOffsetInBits) {
1493 DIVariable DV = Value.getVariable();
1494 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1495 AP.getDwarfDebug()->getDwarfVersion(),
1498 if (Value.isInt()) {
1499 DIBasicType BTy(DV.getType().resolve(TypeIdentifierMap));
1500 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
1501 BTy.getEncoding() == dwarf::DW_ATE_signed_char))
1502 DwarfExpr.AddSignedConstant(Value.getInt());
1504 DwarfExpr.AddUnsignedConstant(Value.getInt());
1505 } else if (Value.isLocation()) {
1506 MachineLocation Loc = Value.getLoc();
1507 DIExpression Expr = Value.getExpression();
1508 if (!Expr || (Expr.getNumElements() == 0))
1510 AP.EmitDwarfRegOp(Streamer, Loc);
1512 // Complex address entry.
1513 if (Loc.getOffset()) {
1514 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1515 DwarfExpr.AddExpression(Expr.begin(), Expr.end(), PieceOffsetInBits);
1517 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1521 // else ... ignore constant fp. There is not any good way to
1522 // to represent them here in dwarf.
1527 void DebugLocEntry::finalize(const AsmPrinter &AP,
1528 const DITypeIdentifierMap &TypeIdentifierMap) {
1529 BufferByteStreamer Streamer(DWARFBytes, Comments);
1530 const DebugLocEntry::Value Value = Values[0];
1531 if (Value.isBitPiece()) {
1532 // Emit all pieces that belong to the same variable and range.
1533 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1534 return P.isBitPiece();
1535 }) && "all values are expected to be pieces");
1536 assert(std::is_sorted(Values.begin(), Values.end()) &&
1537 "pieces are expected to be sorted");
1539 unsigned Offset = 0;
1540 for (auto Piece : Values) {
1541 DIExpression Expr = Piece.getExpression();
1542 unsigned PieceOffset = Expr.getBitPieceOffset();
1543 unsigned PieceSize = Expr.getBitPieceSize();
1544 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1545 if (Offset < PieceOffset) {
1546 // The DWARF spec seriously mandates pieces with no locations for gaps.
1547 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1548 AP.getDwarfDebug()->getDwarfVersion(),
1550 Expr.AddOpPiece(PieceOffset-Offset, 0);
1551 Offset += PieceOffset-Offset;
1553 Offset += PieceSize;
1556 DIVariable Var = Piece.getVariable();
1557 unsigned VarSize = Var.getSizeInBits(TypeIdentifierMap);
1558 assert(PieceSize+PieceOffset <= VarSize
1559 && "piece is larger than or outside of variable");
1560 assert(PieceSize != VarSize
1561 && "piece covers entire variable");
1563 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Piece, PieceOffset);
1566 assert(Values.size() == 1 && "only pieces may have >1 value");
1567 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Value, 0);
1572 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
1573 Asm->OutStreamer.AddComment("Loc expr size");
1574 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
1575 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
1576 Asm->EmitLabelDifference(end, begin, 2);
1577 Asm->OutStreamer.EmitLabel(begin);
1579 APByteStreamer Streamer(*Asm);
1580 emitDebugLocEntry(Streamer, Entry);
1582 Asm->OutStreamer.EmitLabel(end);
1585 // Emit locations into the debug loc section.
1586 void DwarfDebug::emitDebugLoc() {
1587 // Start the dwarf loc section.
1588 Asm->OutStreamer.SwitchSection(
1589 Asm->getObjFileLowering().getDwarfLocSection());
1590 unsigned char Size = Asm->getDataLayout().getPointerSize();
1591 for (const auto &DebugLoc : DotDebugLocEntries) {
1592 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1593 const DwarfCompileUnit *CU = DebugLoc.CU;
1594 for (const auto &Entry : DebugLoc.List) {
1595 // Set up the range. This range is relative to the entry point of the
1596 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1597 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1598 if (auto *Base = CU->getBaseAddress()) {
1599 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
1600 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
1602 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
1603 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
1606 emitDebugLocEntryLocation(Entry);
1608 Asm->OutStreamer.EmitIntValue(0, Size);
1609 Asm->OutStreamer.EmitIntValue(0, Size);
1613 void DwarfDebug::emitDebugLocDWO() {
1614 Asm->OutStreamer.SwitchSection(
1615 Asm->getObjFileLowering().getDwarfLocDWOSection());
1616 for (const auto &DebugLoc : DotDebugLocEntries) {
1617 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1618 for (const auto &Entry : DebugLoc.List) {
1619 // Just always use start_length for now - at least that's one address
1620 // rather than two. We could get fancier and try to, say, reuse an
1621 // address we know we've emitted elsewhere (the start of the function?
1622 // The start of the CU or CU subrange that encloses this range?)
1623 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1624 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
1625 Asm->EmitULEB128(idx);
1626 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
1628 emitDebugLocEntryLocation(Entry);
1630 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1635 const MCSymbol *Start, *End;
1638 // Emit a debug aranges section, containing a CU lookup for any
1639 // address we can tie back to a CU.
1640 void DwarfDebug::emitDebugARanges() {
1641 // Provides a unique id per text section.
1642 MapVector<const MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1644 // Filter labels by section.
1645 for (const SymbolCU &SCU : ArangeLabels) {
1646 if (SCU.Sym->isInSection()) {
1647 // Make a note of this symbol and it's section.
1648 const MCSection *Section = &SCU.Sym->getSection();
1649 if (!Section->getKind().isMetadata())
1650 SectionMap[Section].push_back(SCU);
1652 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1653 // appear in the output. This sucks as we rely on sections to build
1654 // arange spans. We can do it without, but it's icky.
1655 SectionMap[nullptr].push_back(SCU);
1659 // Add terminating symbols for each section.
1660 for (const auto &I : SectionMap) {
1661 const MCSection *Section = I.first;
1662 MCSymbol *Sym = nullptr;
1665 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1666 // if we know the section name up-front. For user-created sections, the
1667 // resulting label may not be valid to use as a label. (section names can
1668 // use a greater set of characters on some systems)
1669 Sym = Asm->createTempSymbol("debug_end");
1670 Asm->OutStreamer.SwitchSection(Section);
1671 Asm->OutStreamer.EmitLabel(Sym);
1674 // Insert a final terminator.
1675 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1678 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1680 for (auto &I : SectionMap) {
1681 const MCSection *Section = I.first;
1682 SmallVector<SymbolCU, 8> &List = I.second;
1683 if (List.size() < 2)
1686 // If we have no section (e.g. common), just write out
1687 // individual spans for each symbol.
1689 for (const SymbolCU &Cur : List) {
1691 Span.Start = Cur.Sym;
1694 Spans[Cur.CU].push_back(Span);
1699 // Sort the symbols by offset within the section.
1700 std::sort(List.begin(), List.end(),
1701 [&](const SymbolCU &A, const SymbolCU &B) {
1702 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
1703 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
1705 // Symbols with no order assigned should be placed at the end.
1706 // (e.g. section end labels)
1714 // Build spans between each label.
1715 const MCSymbol *StartSym = List[0].Sym;
1716 for (size_t n = 1, e = List.size(); n < e; n++) {
1717 const SymbolCU &Prev = List[n - 1];
1718 const SymbolCU &Cur = List[n];
1720 // Try and build the longest span we can within the same CU.
1721 if (Cur.CU != Prev.CU) {
1723 Span.Start = StartSym;
1725 Spans[Prev.CU].push_back(Span);
1731 // Start the dwarf aranges section.
1732 Asm->OutStreamer.SwitchSection(
1733 Asm->getObjFileLowering().getDwarfARangesSection());
1735 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1737 // Build a list of CUs used.
1738 std::vector<DwarfCompileUnit *> CUs;
1739 for (const auto &it : Spans) {
1740 DwarfCompileUnit *CU = it.first;
1744 // Sort the CU list (again, to ensure consistent output order).
1745 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1746 return A->getUniqueID() < B->getUniqueID();
1749 // Emit an arange table for each CU we used.
1750 for (DwarfCompileUnit *CU : CUs) {
1751 std::vector<ArangeSpan> &List = Spans[CU];
1753 // Describe the skeleton CU's offset and length, not the dwo file's.
1754 if (auto *Skel = CU->getSkeleton())
1757 // Emit size of content not including length itself.
1758 unsigned ContentSize =
1759 sizeof(int16_t) + // DWARF ARange version number
1760 sizeof(int32_t) + // Offset of CU in the .debug_info section
1761 sizeof(int8_t) + // Pointer Size (in bytes)
1762 sizeof(int8_t); // Segment Size (in bytes)
1764 unsigned TupleSize = PtrSize * 2;
1766 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1768 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1770 ContentSize += Padding;
1771 ContentSize += (List.size() + 1) * TupleSize;
1773 // For each compile unit, write the list of spans it covers.
1774 Asm->OutStreamer.AddComment("Length of ARange Set");
1775 Asm->EmitInt32(ContentSize);
1776 Asm->OutStreamer.AddComment("DWARF Arange version number");
1777 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1778 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
1779 Asm->emitSectionOffset(CU->getLabelBegin());
1780 Asm->OutStreamer.AddComment("Address Size (in bytes)");
1781 Asm->EmitInt8(PtrSize);
1782 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
1785 Asm->OutStreamer.EmitFill(Padding, 0xff);
1787 for (const ArangeSpan &Span : List) {
1788 Asm->EmitLabelReference(Span.Start, PtrSize);
1790 // Calculate the size as being from the span start to it's end.
1792 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1794 // For symbols without an end marker (e.g. common), we
1795 // write a single arange entry containing just that one symbol.
1796 uint64_t Size = SymSize[Span.Start];
1800 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
1804 Asm->OutStreamer.AddComment("ARange terminator");
1805 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1806 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1810 // Emit visible names into a debug ranges section.
1811 void DwarfDebug::emitDebugRanges() {
1812 // Start the dwarf ranges section.
1813 Asm->OutStreamer.SwitchSection(
1814 Asm->getObjFileLowering().getDwarfRangesSection());
1816 // Size for our labels.
1817 unsigned char Size = Asm->getDataLayout().getPointerSize();
1819 // Grab the specific ranges for the compile units in the module.
1820 for (const auto &I : CUMap) {
1821 DwarfCompileUnit *TheCU = I.second;
1823 if (auto *Skel = TheCU->getSkeleton())
1826 // Iterate over the misc ranges for the compile units in the module.
1827 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1828 // Emit our symbol so we can find the beginning of the range.
1829 Asm->OutStreamer.EmitLabel(List.getSym());
1831 for (const RangeSpan &Range : List.getRanges()) {
1832 const MCSymbol *Begin = Range.getStart();
1833 const MCSymbol *End = Range.getEnd();
1834 assert(Begin && "Range without a begin symbol?");
1835 assert(End && "Range without an end symbol?");
1836 if (auto *Base = TheCU->getBaseAddress()) {
1837 Asm->EmitLabelDifference(Begin, Base, Size);
1838 Asm->EmitLabelDifference(End, Base, Size);
1840 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
1841 Asm->OutStreamer.EmitSymbolValue(End, Size);
1845 // And terminate the list with two 0 values.
1846 Asm->OutStreamer.EmitIntValue(0, Size);
1847 Asm->OutStreamer.EmitIntValue(0, Size);
1852 // DWARF5 Experimental Separate Dwarf emitters.
1854 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1855 std::unique_ptr<DwarfUnit> NewU) {
1856 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1857 U.getCUNode().getSplitDebugFilename());
1859 if (!CompilationDir.empty())
1860 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1862 addGnuPubAttributes(*NewU, Die);
1864 SkeletonHolder.addUnit(std::move(NewU));
1867 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1868 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1869 // DW_AT_addr_base, DW_AT_ranges_base.
1870 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1872 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1873 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1874 DwarfCompileUnit &NewCU = *OwnedUnit;
1875 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1877 NewCU.initStmtList();
1879 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1884 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1885 // compile units that would normally be in debug_info.
1886 void DwarfDebug::emitDebugInfoDWO() {
1887 assert(useSplitDwarf() && "No split dwarf debug info?");
1888 // Don't emit relocations into the dwo file.
1889 InfoHolder.emitUnits(/* UseOffsets */ true);
1892 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1893 // abbreviations for the .debug_info.dwo section.
1894 void DwarfDebug::emitDebugAbbrevDWO() {
1895 assert(useSplitDwarf() && "No split dwarf?");
1896 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1899 void DwarfDebug::emitDebugLineDWO() {
1900 assert(useSplitDwarf() && "No split dwarf?");
1901 Asm->OutStreamer.SwitchSection(
1902 Asm->getObjFileLowering().getDwarfLineDWOSection());
1903 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
1906 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1907 // string section and is identical in format to traditional .debug_str
1909 void DwarfDebug::emitDebugStrDWO() {
1910 assert(useSplitDwarf() && "No split dwarf?");
1911 const MCSection *OffSec =
1912 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1913 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1917 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1918 if (!useSplitDwarf())
1921 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
1922 return &SplitTypeUnitFileTable;
1925 static uint64_t makeTypeSignature(StringRef Identifier) {
1927 Hash.update(Identifier);
1928 // ... take the least significant 8 bytes and return those. Our MD5
1929 // implementation always returns its results in little endian, swap bytes
1931 MD5::MD5Result Result;
1933 return support::endian::read64le(Result + 8);
1936 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1937 StringRef Identifier, DIE &RefDie,
1938 DICompositeType CTy) {
1939 // Fast path if we're building some type units and one has already used the
1940 // address pool we know we're going to throw away all this work anyway, so
1941 // don't bother building dependent types.
1942 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1945 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1947 CU.addDIETypeSignature(RefDie, *TU);
1951 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1952 AddrPool.resetUsedFlag();
1954 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1955 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1956 this, &InfoHolder, getDwoLineTable(CU));
1957 DwarfTypeUnit &NewTU = *OwnedUnit;
1958 DIE &UnitDie = NewTU.getUnitDie();
1960 TypeUnitsUnderConstruction.push_back(
1961 std::make_pair(std::move(OwnedUnit), CTy));
1963 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1966 uint64_t Signature = makeTypeSignature(Identifier);
1967 NewTU.setTypeSignature(Signature);
1969 if (useSplitDwarf())
1970 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1972 CU.applyStmtList(UnitDie);
1974 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1977 NewTU.setType(NewTU.createTypeDIE(CTy));
1980 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1981 TypeUnitsUnderConstruction.clear();
1983 // Types referencing entries in the address table cannot be placed in type
1985 if (AddrPool.hasBeenUsed()) {
1987 // Remove all the types built while building this type.
1988 // This is pessimistic as some of these types might not be dependent on
1989 // the type that used an address.
1990 for (const auto &TU : TypeUnitsToAdd)
1991 DwarfTypeUnits.erase(TU.second);
1993 // Construct this type in the CU directly.
1994 // This is inefficient because all the dependent types will be rebuilt
1995 // from scratch, including building them in type units, discovering that
1996 // they depend on addresses, throwing them out and rebuilding them.
1997 CU.constructTypeDIE(RefDie, CTy);
2001 // If the type wasn't dependent on fission addresses, finish adding the type
2002 // and all its dependent types.
2003 for (auto &TU : TypeUnitsToAdd)
2004 InfoHolder.addUnit(std::move(TU.first));
2006 CU.addDIETypeSignature(RefDie, NewTU);
2009 // Accelerator table mutators - add each name along with its companion
2010 // DIE to the proper table while ensuring that the name that we're going
2011 // to reference is in the string table. We do this since the names we
2012 // add may not only be identical to the names in the DIE.
2013 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2014 if (!useDwarfAccelTables())
2016 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2020 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2021 if (!useDwarfAccelTables())
2023 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2027 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2028 if (!useDwarfAccelTables())
2030 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2034 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2035 if (!useDwarfAccelTables())
2037 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),