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.isVariable() && "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(DIDerivedType(Ty).getTypeDerivedFrom());
176 DIArray Elements = DICompositeType(subType).getElements();
177 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
178 DIDerivedType DT(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 DIDescriptor D(Context);
306 if (D.isSubprogram())
309 return isSubprogramContext(resolve(DIType(Context).getContext()));
313 /// Check whether we should create a DIE for the given Scope, return true
314 /// if we don't create a DIE (the corresponding DIE is null).
315 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
316 if (Scope->isAbstractScope())
319 // We don't create a DIE if there is no Range.
320 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
324 if (Ranges.size() > 1)
327 // We don't create a DIE if we have a single Range and the end label
329 return !getLabelAfterInsn(Ranges.front().second);
332 template <typename Func> void forBothCUs(DwarfCompileUnit &CU, Func F) {
334 if (auto *SkelCU = CU.getSkeleton())
338 void DwarfDebug::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
339 assert(Scope && Scope->getScopeNode());
340 assert(Scope->isAbstractScope());
341 assert(!Scope->getInlinedAt());
343 const MDNode *SP = Scope->getScopeNode();
345 ProcessedSPNodes.insert(SP);
347 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
348 // was inlined from another compile unit.
349 auto &CU = SPMap[SP];
350 forBothCUs(*CU, [&](DwarfCompileUnit &CU) {
351 CU.constructAbstractSubprogramScopeDIE(Scope);
355 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
356 if (!GenerateGnuPubSections)
359 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
362 // Create new DwarfCompileUnit for the given metadata node with tag
363 // DW_TAG_compile_unit.
364 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
365 StringRef FN = DIUnit.getFilename();
366 CompilationDir = DIUnit.getDirectory();
368 auto OwnedUnit = make_unique<DwarfCompileUnit>(
369 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
370 DwarfCompileUnit &NewCU = *OwnedUnit;
371 DIE &Die = NewCU.getUnitDie();
372 InfoHolder.addUnit(std::move(OwnedUnit));
374 NewCU.setSkeleton(constructSkeletonCU(NewCU));
376 // LTO with assembly output shares a single line table amongst multiple CUs.
377 // To avoid the compilation directory being ambiguous, let the line table
378 // explicitly describe the directory of all files, never relying on the
379 // compilation directory.
380 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
381 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
382 NewCU.getUniqueID(), CompilationDir);
384 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
385 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
386 DIUnit.getLanguage());
387 NewCU.addString(Die, dwarf::DW_AT_name, FN);
389 if (!useSplitDwarf()) {
390 NewCU.initStmtList();
392 // If we're using split dwarf the compilation dir is going to be in the
393 // skeleton CU and so we don't need to duplicate it here.
394 if (!CompilationDir.empty())
395 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
397 addGnuPubAttributes(NewCU, Die);
400 if (DIUnit.isOptimized())
401 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
403 StringRef Flags = DIUnit.getFlags();
405 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
407 if (unsigned RVer = DIUnit.getRunTimeVersion())
408 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
409 dwarf::DW_FORM_data1, RVer);
412 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection());
414 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
416 CUMap.insert(std::make_pair(DIUnit, &NewCU));
417 CUDieMap.insert(std::make_pair(&Die, &NewCU));
421 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
423 DIImportedEntity Module(N);
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(
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(VI.Var);
736 assert(DV->isValidLocationForIntrinsic(VI.Loc) &&
737 "Expected inlined-at fields to agree");
738 DIExpression Expr(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(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(Variables.getElement(i));
946 assert(DV.isVariable());
947 if (!Processed.insert(DV).second)
949 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.get()->getScope())) {
950 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
952 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, NoExpr, this));
953 InfoHolder.addScopeVariable(Scope, ConcreteVariables.back().get());
958 // Return Label preceding the instruction.
959 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
960 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
961 assert(Label && "Didn't insert label before instruction");
965 // Return Label immediately following the instruction.
966 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
967 return LabelsAfterInsn.lookup(MI);
970 // Process beginning of an instruction.
971 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
972 assert(CurMI == nullptr);
974 // Check if source location changes, but ignore DBG_VALUE locations.
975 if (!MI->isDebugValue()) {
976 DebugLoc DL = MI->getDebugLoc();
977 if (DL != PrevInstLoc) {
981 if (DL == PrologEndLoc) {
982 Flags |= DWARF2_FLAG_PROLOGUE_END;
983 PrologEndLoc = DebugLoc();
984 Flags |= DWARF2_FLAG_IS_STMT;
987 Asm->OutStreamer.getContext().getCurrentDwarfLoc().getLine())
988 Flags |= DWARF2_FLAG_IS_STMT;
990 const MDNode *Scope = DL.getScope();
991 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
992 } else if (UnknownLocations) {
994 recordSourceLine(0, 0, nullptr, 0);
999 // Insert labels where requested.
1000 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1001 LabelsBeforeInsn.find(MI);
1004 if (I == LabelsBeforeInsn.end())
1007 // Label already assigned.
1012 PrevLabel = MMI->getContext().CreateTempSymbol();
1013 Asm->OutStreamer.EmitLabel(PrevLabel);
1015 I->second = PrevLabel;
1018 // Process end of an instruction.
1019 void DwarfDebug::endInstruction() {
1020 assert(CurMI != nullptr);
1021 // Don't create a new label after DBG_VALUE instructions.
1022 // They don't generate code.
1023 if (!CurMI->isDebugValue())
1024 PrevLabel = nullptr;
1026 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1027 LabelsAfterInsn.find(CurMI);
1031 if (I == LabelsAfterInsn.end())
1034 // Label already assigned.
1038 // We need a label after this instruction.
1040 PrevLabel = MMI->getContext().CreateTempSymbol();
1041 Asm->OutStreamer.EmitLabel(PrevLabel);
1043 I->second = PrevLabel;
1046 // Each LexicalScope has first instruction and last instruction to mark
1047 // beginning and end of a scope respectively. Create an inverse map that list
1048 // scopes starts (and ends) with an instruction. One instruction may start (or
1049 // end) multiple scopes. Ignore scopes that are not reachable.
1050 void DwarfDebug::identifyScopeMarkers() {
1051 SmallVector<LexicalScope *, 4> WorkList;
1052 WorkList.push_back(LScopes.getCurrentFunctionScope());
1053 while (!WorkList.empty()) {
1054 LexicalScope *S = WorkList.pop_back_val();
1056 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1057 if (!Children.empty())
1058 WorkList.append(Children.begin(), Children.end());
1060 if (S->isAbstractScope())
1063 for (const InsnRange &R : S->getRanges()) {
1064 assert(R.first && "InsnRange does not have first instruction!");
1065 assert(R.second && "InsnRange does not have second instruction!");
1066 requestLabelBeforeInsn(R.first);
1067 requestLabelAfterInsn(R.second);
1072 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1073 // First known non-DBG_VALUE and non-frame setup location marks
1074 // the beginning of the function body.
1075 for (const auto &MBB : *MF)
1076 for (const auto &MI : MBB)
1077 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1079 // Did the target forget to set the FrameSetup flag for CFI insns?
1080 assert(!MI.isCFIInstruction() &&
1081 "First non-frame-setup instruction is a CFI instruction.");
1082 return MI.getDebugLoc();
1087 // Gather pre-function debug information. Assumes being called immediately
1088 // after the function entry point has been emitted.
1089 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1092 // If there's no debug info for the function we're not going to do anything.
1093 if (!MMI->hasDebugInfo())
1096 auto DI = FunctionDIs.find(MF->getFunction());
1097 if (DI == FunctionDIs.end())
1100 // Grab the lexical scopes for the function, if we don't have any of those
1101 // then we're not going to be able to do anything.
1102 LScopes.initialize(*MF);
1103 if (LScopes.empty())
1106 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1108 // Make sure that each lexical scope will have a begin/end label.
1109 identifyScopeMarkers();
1111 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1112 // belongs to so that we add to the correct per-cu line table in the
1114 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1115 // FnScope->getScopeNode() and DI->second should represent the same function,
1116 // though they may not be the same MDNode due to inline functions merged in
1117 // LTO where the debug info metadata still differs (either due to distinct
1118 // written differences - two versions of a linkonce_odr function
1119 // written/copied into two separate files, or some sub-optimal metadata that
1120 // isn't structurally identical (see: file path/name info from clang, which
1121 // includes the directory of the cpp file being built, even when the file name
1122 // is absolute (such as an <> lookup header)))
1123 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1124 assert(TheCU && "Unable to find compile unit!");
1125 if (Asm->OutStreamer.hasRawTextSupport())
1126 // Use a single line table if we are generating assembly.
1127 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1129 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1131 // Calculate history for local variables.
1132 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1135 // Request labels for the full history.
1136 for (const auto &I : DbgValues) {
1137 const auto &Ranges = I.second;
1141 // The first mention of a function argument gets the CurrentFnBegin
1142 // label, so arguments are visible when breaking at function entry.
1143 DIVariable DIVar(Ranges.front().first->getDebugVariable());
1144 if (DIVar.isVariable() && DIVar.getTag() == dwarf::DW_TAG_arg_variable &&
1145 getDISubprogram(DIVar.getContext()).describes(MF->getFunction())) {
1146 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1147 if (Ranges.front().first->getDebugExpression().isBitPiece()) {
1148 // Mark all non-overlapping initial pieces.
1149 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1150 DIExpression Piece = I->first->getDebugExpression();
1151 if (std::all_of(Ranges.begin(), I,
1152 [&](DbgValueHistoryMap::InstrRange Pred) {
1153 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1155 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1162 for (const auto &Range : Ranges) {
1163 requestLabelBeforeInsn(Range.first);
1165 requestLabelAfterInsn(Range.second);
1169 PrevInstLoc = DebugLoc();
1170 PrevLabel = Asm->getFunctionBegin();
1172 // Record beginning of function.
1173 PrologEndLoc = findPrologueEndLoc(MF);
1174 if (MDLocation *L = PrologEndLoc) {
1175 // We'd like to list the prologue as "not statements" but GDB behaves
1176 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1177 auto *SP = L->getInlinedAtScope()->getSubprogram();
1178 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1182 // Gather and emit post-function debug information.
1183 void DwarfDebug::endFunction(const MachineFunction *MF) {
1184 assert(CurFn == MF &&
1185 "endFunction should be called with the same function as beginFunction");
1187 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1188 !FunctionDIs.count(MF->getFunction())) {
1189 // If we don't have a lexical scope for this function then there will
1190 // be a hole in the range information. Keep note of this by setting the
1191 // previously used section to nullptr.
1197 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1198 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1200 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1201 DISubprogram SP(FnScope->getScopeNode());
1202 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1204 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1205 collectVariableInfo(TheCU, SP, ProcessedVars);
1207 // Add the range of this function to the list of ranges for the CU.
1208 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1210 // Under -gmlt, skip building the subprogram if there are no inlined
1211 // subroutines inside it.
1212 if (TheCU.getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly &&
1213 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1214 assert(InfoHolder.getScopeVariables().empty());
1215 assert(DbgValues.empty());
1216 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1217 // by a -gmlt CU. Add a test and remove this assertion.
1218 assert(AbstractVariables.empty());
1219 LabelsBeforeInsn.clear();
1220 LabelsAfterInsn.clear();
1221 PrevLabel = nullptr;
1227 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1229 // Construct abstract scopes.
1230 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1231 DISubprogram SP(AScope->getScopeNode());
1232 assert(SP.isSubprogram());
1233 // Collect info for variables that were optimized out.
1234 DIArray Variables = SP.getVariables();
1235 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1236 DIVariable DV(Variables.getElement(i));
1237 assert(DV && DV.isVariable());
1238 if (!ProcessedVars.insert(DV).second)
1240 ensureAbstractVariableIsCreated(DV, DV.getContext());
1241 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1242 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1244 constructAbstractSubprogramScopeDIE(AScope);
1247 TheCU.constructSubprogramScopeDIE(FnScope);
1248 if (auto *SkelCU = TheCU.getSkeleton())
1249 if (!LScopes.getAbstractScopesList().empty())
1250 SkelCU->constructSubprogramScopeDIE(FnScope);
1253 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1254 // DbgVariables except those that are also in AbstractVariables (since they
1255 // can be used cross-function)
1256 InfoHolder.getScopeVariables().clear();
1258 LabelsBeforeInsn.clear();
1259 LabelsAfterInsn.clear();
1260 PrevLabel = nullptr;
1264 // Register a source line with debug info. Returns the unique label that was
1265 // emitted and which provides correspondence to the source line list.
1266 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1271 unsigned Discriminator = 0;
1272 if (DIScope Scope = DIScope(S)) {
1273 assert(Scope.isScope());
1274 Fn = Scope.getFilename();
1275 Dir = Scope.getDirectory();
1276 if (Scope.isLexicalBlockFile())
1277 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1279 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1280 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1281 .getOrCreateSourceID(Fn, Dir);
1283 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1287 //===----------------------------------------------------------------------===//
1289 //===----------------------------------------------------------------------===//
1291 // Emit the debug info section.
1292 void DwarfDebug::emitDebugInfo() {
1293 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1294 Holder.emitUnits(/* UseOffsets */ false);
1297 // Emit the abbreviation section.
1298 void DwarfDebug::emitAbbreviations() {
1299 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1301 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1304 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1305 StringRef TableName) {
1306 Accel.FinalizeTable(Asm, TableName);
1307 Asm->OutStreamer.SwitchSection(Section);
1309 // Emit the full data.
1310 Accel.emit(Asm, Section->getBeginSymbol(), this);
1313 // Emit visible names into a hashed accelerator table section.
1314 void DwarfDebug::emitAccelNames() {
1315 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1319 // Emit objective C classes and categories into a hashed accelerator table
1321 void DwarfDebug::emitAccelObjC() {
1322 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1326 // Emit namespace dies into a hashed accelerator table.
1327 void DwarfDebug::emitAccelNamespaces() {
1328 emitAccel(AccelNamespace,
1329 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1333 // Emit type dies into a hashed accelerator table.
1334 void DwarfDebug::emitAccelTypes() {
1335 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1339 // Public name handling.
1340 // The format for the various pubnames:
1342 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1343 // for the DIE that is named.
1345 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1346 // into the CU and the index value is computed according to the type of value
1347 // for the DIE that is named.
1349 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1350 // it's the offset within the debug_info/debug_types dwo section, however, the
1351 // reference in the pubname header doesn't change.
1353 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1354 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1356 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1358 // We could have a specification DIE that has our most of our knowledge,
1359 // look for that now.
1360 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1362 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1363 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1364 Linkage = dwarf::GIEL_EXTERNAL;
1365 } else if (Die->findAttribute(dwarf::DW_AT_external))
1366 Linkage = dwarf::GIEL_EXTERNAL;
1368 switch (Die->getTag()) {
1369 case dwarf::DW_TAG_class_type:
1370 case dwarf::DW_TAG_structure_type:
1371 case dwarf::DW_TAG_union_type:
1372 case dwarf::DW_TAG_enumeration_type:
1373 return dwarf::PubIndexEntryDescriptor(
1374 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1375 ? dwarf::GIEL_STATIC
1376 : dwarf::GIEL_EXTERNAL);
1377 case dwarf::DW_TAG_typedef:
1378 case dwarf::DW_TAG_base_type:
1379 case dwarf::DW_TAG_subrange_type:
1380 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1381 case dwarf::DW_TAG_namespace:
1382 return dwarf::GIEK_TYPE;
1383 case dwarf::DW_TAG_subprogram:
1384 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1385 case dwarf::DW_TAG_variable:
1386 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1387 case dwarf::DW_TAG_enumerator:
1388 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1389 dwarf::GIEL_STATIC);
1391 return dwarf::GIEK_NONE;
1395 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1397 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1398 const MCSection *PSec =
1399 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1400 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1402 emitDebugPubSection(GnuStyle, PSec, "Names",
1403 &DwarfCompileUnit::getGlobalNames);
1406 void DwarfDebug::emitDebugPubSection(
1407 bool GnuStyle, const MCSection *PSec, StringRef Name,
1408 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1409 for (const auto &NU : CUMap) {
1410 DwarfCompileUnit *TheU = NU.second;
1412 const auto &Globals = (TheU->*Accessor)();
1414 if (Globals.empty())
1417 if (auto *Skeleton = TheU->getSkeleton())
1420 // Start the dwarf pubnames section.
1421 Asm->OutStreamer.SwitchSection(PSec);
1424 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1425 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1426 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1427 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1429 Asm->OutStreamer.EmitLabel(BeginLabel);
1431 Asm->OutStreamer.AddComment("DWARF Version");
1432 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1434 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1435 Asm->emitSectionOffset(TheU->getLabelBegin());
1437 Asm->OutStreamer.AddComment("Compilation Unit Length");
1438 Asm->EmitInt32(TheU->getLength());
1440 // Emit the pubnames for this compilation unit.
1441 for (const auto &GI : Globals) {
1442 const char *Name = GI.getKeyData();
1443 const DIE *Entity = GI.second;
1445 Asm->OutStreamer.AddComment("DIE offset");
1446 Asm->EmitInt32(Entity->getOffset());
1449 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1450 Asm->OutStreamer.AddComment(
1451 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1452 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1453 Asm->EmitInt8(Desc.toBits());
1456 Asm->OutStreamer.AddComment("External Name");
1457 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1460 Asm->OutStreamer.AddComment("End Mark");
1462 Asm->OutStreamer.EmitLabel(EndLabel);
1466 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1467 const MCSection *PSec =
1468 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1469 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1471 emitDebugPubSection(GnuStyle, PSec, "Types",
1472 &DwarfCompileUnit::getGlobalTypes);
1475 // Emit visible names into a debug str section.
1476 void DwarfDebug::emitDebugStr() {
1477 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1478 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1482 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1483 const DebugLocEntry &Entry) {
1484 auto Comment = Entry.getComments().begin();
1485 auto End = Entry.getComments().end();
1486 for (uint8_t Byte : Entry.getDWARFBytes())
1487 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1490 static void emitDebugLocValue(const AsmPrinter &AP,
1491 const DITypeIdentifierMap &TypeIdentifierMap,
1492 ByteStreamer &Streamer,
1493 const DebugLocEntry::Value &Value,
1494 unsigned PieceOffsetInBits) {
1495 DIVariable DV = Value.getVariable();
1496 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1497 AP.getDwarfDebug()->getDwarfVersion(),
1500 if (Value.isInt()) {
1501 MDType *T = DV.getType().resolve(TypeIdentifierMap);
1502 auto *B = dyn_cast<MDBasicType>(T);
1503 if (B && (B->getEncoding() == dwarf::DW_ATE_signed ||
1504 B->getEncoding() == dwarf::DW_ATE_signed_char))
1505 DwarfExpr.AddSignedConstant(Value.getInt());
1507 DwarfExpr.AddUnsignedConstant(Value.getInt());
1508 } else if (Value.isLocation()) {
1509 MachineLocation Loc = Value.getLoc();
1510 DIExpression Expr = Value.getExpression();
1511 if (!Expr || (Expr.getNumElements() == 0))
1513 AP.EmitDwarfRegOp(Streamer, Loc);
1515 // Complex address entry.
1516 if (Loc.getOffset()) {
1517 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1518 DwarfExpr.AddExpression(Expr.begin(), Expr.end(), PieceOffsetInBits);
1520 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1524 // else ... ignore constant fp. There is not any good way to
1525 // to represent them here in dwarf.
1530 void DebugLocEntry::finalize(const AsmPrinter &AP,
1531 const DITypeIdentifierMap &TypeIdentifierMap) {
1532 BufferByteStreamer Streamer(DWARFBytes, Comments);
1533 const DebugLocEntry::Value Value = Values[0];
1534 if (Value.isBitPiece()) {
1535 // Emit all pieces that belong to the same variable and range.
1536 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1537 return P.isBitPiece();
1538 }) && "all values are expected to be pieces");
1539 assert(std::is_sorted(Values.begin(), Values.end()) &&
1540 "pieces are expected to be sorted");
1542 unsigned Offset = 0;
1543 for (auto Piece : Values) {
1544 DIExpression Expr = Piece.getExpression();
1545 unsigned PieceOffset = Expr.getBitPieceOffset();
1546 unsigned PieceSize = Expr.getBitPieceSize();
1547 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1548 if (Offset < PieceOffset) {
1549 // The DWARF spec seriously mandates pieces with no locations for gaps.
1550 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1551 AP.getDwarfDebug()->getDwarfVersion(),
1553 Expr.AddOpPiece(PieceOffset-Offset, 0);
1554 Offset += PieceOffset-Offset;
1556 Offset += PieceSize;
1559 DIVariable Var = Piece.getVariable();
1560 unsigned VarSize = Var.getSizeInBits(TypeIdentifierMap);
1561 assert(PieceSize+PieceOffset <= VarSize
1562 && "piece is larger than or outside of variable");
1563 assert(PieceSize != VarSize
1564 && "piece covers entire variable");
1566 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Piece, PieceOffset);
1569 assert(Values.size() == 1 && "only pieces may have >1 value");
1570 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Value, 0);
1575 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
1576 Asm->OutStreamer.AddComment("Loc expr size");
1577 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
1578 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
1579 Asm->EmitLabelDifference(end, begin, 2);
1580 Asm->OutStreamer.EmitLabel(begin);
1582 APByteStreamer Streamer(*Asm);
1583 emitDebugLocEntry(Streamer, Entry);
1585 Asm->OutStreamer.EmitLabel(end);
1588 // Emit locations into the debug loc section.
1589 void DwarfDebug::emitDebugLoc() {
1590 // Start the dwarf loc section.
1591 Asm->OutStreamer.SwitchSection(
1592 Asm->getObjFileLowering().getDwarfLocSection());
1593 unsigned char Size = Asm->getDataLayout().getPointerSize();
1594 for (const auto &DebugLoc : DotDebugLocEntries) {
1595 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1596 const DwarfCompileUnit *CU = DebugLoc.CU;
1597 for (const auto &Entry : DebugLoc.List) {
1598 // Set up the range. This range is relative to the entry point of the
1599 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1600 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1601 if (auto *Base = CU->getBaseAddress()) {
1602 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
1603 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
1605 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
1606 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
1609 emitDebugLocEntryLocation(Entry);
1611 Asm->OutStreamer.EmitIntValue(0, Size);
1612 Asm->OutStreamer.EmitIntValue(0, Size);
1616 void DwarfDebug::emitDebugLocDWO() {
1617 Asm->OutStreamer.SwitchSection(
1618 Asm->getObjFileLowering().getDwarfLocDWOSection());
1619 for (const auto &DebugLoc : DotDebugLocEntries) {
1620 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1621 for (const auto &Entry : DebugLoc.List) {
1622 // Just always use start_length for now - at least that's one address
1623 // rather than two. We could get fancier and try to, say, reuse an
1624 // address we know we've emitted elsewhere (the start of the function?
1625 // The start of the CU or CU subrange that encloses this range?)
1626 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1627 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
1628 Asm->EmitULEB128(idx);
1629 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
1631 emitDebugLocEntryLocation(Entry);
1633 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1638 const MCSymbol *Start, *End;
1641 // Emit a debug aranges section, containing a CU lookup for any
1642 // address we can tie back to a CU.
1643 void DwarfDebug::emitDebugARanges() {
1644 // Provides a unique id per text section.
1645 MapVector<const MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1647 // Filter labels by section.
1648 for (const SymbolCU &SCU : ArangeLabels) {
1649 if (SCU.Sym->isInSection()) {
1650 // Make a note of this symbol and it's section.
1651 const MCSection *Section = &SCU.Sym->getSection();
1652 if (!Section->getKind().isMetadata())
1653 SectionMap[Section].push_back(SCU);
1655 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1656 // appear in the output. This sucks as we rely on sections to build
1657 // arange spans. We can do it without, but it's icky.
1658 SectionMap[nullptr].push_back(SCU);
1662 // Add terminating symbols for each section.
1663 for (const auto &I : SectionMap) {
1664 const MCSection *Section = I.first;
1665 MCSymbol *Sym = nullptr;
1668 Sym = Asm->OutStreamer.endSection(Section);
1670 // Insert a final terminator.
1671 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1674 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1676 for (auto &I : SectionMap) {
1677 const MCSection *Section = I.first;
1678 SmallVector<SymbolCU, 8> &List = I.second;
1679 if (List.size() < 2)
1682 // If we have no section (e.g. common), just write out
1683 // individual spans for each symbol.
1685 for (const SymbolCU &Cur : List) {
1687 Span.Start = Cur.Sym;
1690 Spans[Cur.CU].push_back(Span);
1695 // Sort the symbols by offset within the section.
1696 std::sort(List.begin(), List.end(),
1697 [&](const SymbolCU &A, const SymbolCU &B) {
1698 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
1699 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
1701 // Symbols with no order assigned should be placed at the end.
1702 // (e.g. section end labels)
1710 // Build spans between each label.
1711 const MCSymbol *StartSym = List[0].Sym;
1712 for (size_t n = 1, e = List.size(); n < e; n++) {
1713 const SymbolCU &Prev = List[n - 1];
1714 const SymbolCU &Cur = List[n];
1716 // Try and build the longest span we can within the same CU.
1717 if (Cur.CU != Prev.CU) {
1719 Span.Start = StartSym;
1721 Spans[Prev.CU].push_back(Span);
1727 // Start the dwarf aranges section.
1728 Asm->OutStreamer.SwitchSection(
1729 Asm->getObjFileLowering().getDwarfARangesSection());
1731 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1733 // Build a list of CUs used.
1734 std::vector<DwarfCompileUnit *> CUs;
1735 for (const auto &it : Spans) {
1736 DwarfCompileUnit *CU = it.first;
1740 // Sort the CU list (again, to ensure consistent output order).
1741 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1742 return A->getUniqueID() < B->getUniqueID();
1745 // Emit an arange table for each CU we used.
1746 for (DwarfCompileUnit *CU : CUs) {
1747 std::vector<ArangeSpan> &List = Spans[CU];
1749 // Describe the skeleton CU's offset and length, not the dwo file's.
1750 if (auto *Skel = CU->getSkeleton())
1753 // Emit size of content not including length itself.
1754 unsigned ContentSize =
1755 sizeof(int16_t) + // DWARF ARange version number
1756 sizeof(int32_t) + // Offset of CU in the .debug_info section
1757 sizeof(int8_t) + // Pointer Size (in bytes)
1758 sizeof(int8_t); // Segment Size (in bytes)
1760 unsigned TupleSize = PtrSize * 2;
1762 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1764 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1766 ContentSize += Padding;
1767 ContentSize += (List.size() + 1) * TupleSize;
1769 // For each compile unit, write the list of spans it covers.
1770 Asm->OutStreamer.AddComment("Length of ARange Set");
1771 Asm->EmitInt32(ContentSize);
1772 Asm->OutStreamer.AddComment("DWARF Arange version number");
1773 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1774 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
1775 Asm->emitSectionOffset(CU->getLabelBegin());
1776 Asm->OutStreamer.AddComment("Address Size (in bytes)");
1777 Asm->EmitInt8(PtrSize);
1778 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
1781 Asm->OutStreamer.EmitFill(Padding, 0xff);
1783 for (const ArangeSpan &Span : List) {
1784 Asm->EmitLabelReference(Span.Start, PtrSize);
1786 // Calculate the size as being from the span start to it's end.
1788 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1790 // For symbols without an end marker (e.g. common), we
1791 // write a single arange entry containing just that one symbol.
1792 uint64_t Size = SymSize[Span.Start];
1796 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
1800 Asm->OutStreamer.AddComment("ARange terminator");
1801 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1802 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1806 // Emit visible names into a debug ranges section.
1807 void DwarfDebug::emitDebugRanges() {
1808 // Start the dwarf ranges section.
1809 Asm->OutStreamer.SwitchSection(
1810 Asm->getObjFileLowering().getDwarfRangesSection());
1812 // Size for our labels.
1813 unsigned char Size = Asm->getDataLayout().getPointerSize();
1815 // Grab the specific ranges for the compile units in the module.
1816 for (const auto &I : CUMap) {
1817 DwarfCompileUnit *TheCU = I.second;
1819 if (auto *Skel = TheCU->getSkeleton())
1822 // Iterate over the misc ranges for the compile units in the module.
1823 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1824 // Emit our symbol so we can find the beginning of the range.
1825 Asm->OutStreamer.EmitLabel(List.getSym());
1827 for (const RangeSpan &Range : List.getRanges()) {
1828 const MCSymbol *Begin = Range.getStart();
1829 const MCSymbol *End = Range.getEnd();
1830 assert(Begin && "Range without a begin symbol?");
1831 assert(End && "Range without an end symbol?");
1832 if (auto *Base = TheCU->getBaseAddress()) {
1833 Asm->EmitLabelDifference(Begin, Base, Size);
1834 Asm->EmitLabelDifference(End, Base, Size);
1836 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
1837 Asm->OutStreamer.EmitSymbolValue(End, Size);
1841 // And terminate the list with two 0 values.
1842 Asm->OutStreamer.EmitIntValue(0, Size);
1843 Asm->OutStreamer.EmitIntValue(0, Size);
1848 // DWARF5 Experimental Separate Dwarf emitters.
1850 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1851 std::unique_ptr<DwarfUnit> NewU) {
1852 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1853 U.getCUNode().getSplitDebugFilename());
1855 if (!CompilationDir.empty())
1856 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1858 addGnuPubAttributes(*NewU, Die);
1860 SkeletonHolder.addUnit(std::move(NewU));
1863 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1864 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1865 // DW_AT_addr_base, DW_AT_ranges_base.
1866 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1868 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1869 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1870 DwarfCompileUnit &NewCU = *OwnedUnit;
1871 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1873 NewCU.initStmtList();
1875 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1880 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1881 // compile units that would normally be in debug_info.
1882 void DwarfDebug::emitDebugInfoDWO() {
1883 assert(useSplitDwarf() && "No split dwarf debug info?");
1884 // Don't emit relocations into the dwo file.
1885 InfoHolder.emitUnits(/* UseOffsets */ true);
1888 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1889 // abbreviations for the .debug_info.dwo section.
1890 void DwarfDebug::emitDebugAbbrevDWO() {
1891 assert(useSplitDwarf() && "No split dwarf?");
1892 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1895 void DwarfDebug::emitDebugLineDWO() {
1896 assert(useSplitDwarf() && "No split dwarf?");
1897 Asm->OutStreamer.SwitchSection(
1898 Asm->getObjFileLowering().getDwarfLineDWOSection());
1899 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
1902 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1903 // string section and is identical in format to traditional .debug_str
1905 void DwarfDebug::emitDebugStrDWO() {
1906 assert(useSplitDwarf() && "No split dwarf?");
1907 const MCSection *OffSec =
1908 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1909 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1913 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1914 if (!useSplitDwarf())
1917 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
1918 return &SplitTypeUnitFileTable;
1921 static uint64_t makeTypeSignature(StringRef Identifier) {
1923 Hash.update(Identifier);
1924 // ... take the least significant 8 bytes and return those. Our MD5
1925 // implementation always returns its results in little endian, swap bytes
1927 MD5::MD5Result Result;
1929 return support::endian::read64le(Result + 8);
1932 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1933 StringRef Identifier, DIE &RefDie,
1934 DICompositeType CTy) {
1935 // Fast path if we're building some type units and one has already used the
1936 // address pool we know we're going to throw away all this work anyway, so
1937 // don't bother building dependent types.
1938 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1941 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1943 CU.addDIETypeSignature(RefDie, *TU);
1947 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1948 AddrPool.resetUsedFlag();
1950 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1951 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1952 this, &InfoHolder, getDwoLineTable(CU));
1953 DwarfTypeUnit &NewTU = *OwnedUnit;
1954 DIE &UnitDie = NewTU.getUnitDie();
1956 TypeUnitsUnderConstruction.push_back(
1957 std::make_pair(std::move(OwnedUnit), CTy));
1959 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1962 uint64_t Signature = makeTypeSignature(Identifier);
1963 NewTU.setTypeSignature(Signature);
1965 if (useSplitDwarf())
1966 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1968 CU.applyStmtList(UnitDie);
1970 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1973 NewTU.setType(NewTU.createTypeDIE(CTy));
1976 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1977 TypeUnitsUnderConstruction.clear();
1979 // Types referencing entries in the address table cannot be placed in type
1981 if (AddrPool.hasBeenUsed()) {
1983 // Remove all the types built while building this type.
1984 // This is pessimistic as some of these types might not be dependent on
1985 // the type that used an address.
1986 for (const auto &TU : TypeUnitsToAdd)
1987 DwarfTypeUnits.erase(TU.second);
1989 // Construct this type in the CU directly.
1990 // This is inefficient because all the dependent types will be rebuilt
1991 // from scratch, including building them in type units, discovering that
1992 // they depend on addresses, throwing them out and rebuilding them.
1993 CU.constructTypeDIE(RefDie, CTy);
1997 // If the type wasn't dependent on fission addresses, finish adding the type
1998 // and all its dependent types.
1999 for (auto &TU : TypeUnitsToAdd)
2000 InfoHolder.addUnit(std::move(TU.first));
2002 CU.addDIETypeSignature(RefDie, NewTU);
2005 // Accelerator table mutators - add each name along with its companion
2006 // DIE to the proper table while ensuring that the name that we're going
2007 // to reference is in the string table. We do this since the names we
2008 // add may not only be identical to the names in the DIE.
2009 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2010 if (!useDwarfAccelTables())
2012 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2016 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2017 if (!useDwarfAccelTables())
2019 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2023 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2024 if (!useDwarfAccelTables())
2026 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2030 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2031 if (!useDwarfAccelTables())
2033 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),