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"
16 #include "ByteStreamer.h"
17 #include "DwarfCompileUnit.h"
20 #include "DwarfUnit.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/CodeGen/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 //===----------------------------------------------------------------------===//
110 /// resolve - Look in the DwarfDebug map for the MDNode that
111 /// corresponds to the reference.
112 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
113 return DD->resolve(Ref);
116 bool DbgVariable::isBlockByrefVariable() const {
117 assert(Var.isVariable() && "Invalid complex DbgVariable!");
118 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
121 DIType DbgVariable::getType() const {
122 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
123 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
124 // addresses instead.
125 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
126 /* Byref variables, in Blocks, are declared by the programmer as
127 "SomeType VarName;", but the compiler creates a
128 __Block_byref_x_VarName struct, and gives the variable VarName
129 either the struct, or a pointer to the struct, as its type. This
130 is necessary for various behind-the-scenes things the compiler
131 needs to do with by-reference variables in blocks.
133 However, as far as the original *programmer* is concerned, the
134 variable should still have type 'SomeType', as originally declared.
136 The following function dives into the __Block_byref_x_VarName
137 struct to find the original type of the variable. This will be
138 passed back to the code generating the type for the Debug
139 Information Entry for the variable 'VarName'. 'VarName' will then
140 have the original type 'SomeType' in its debug information.
142 The original type 'SomeType' will be the type of the field named
143 'VarName' inside the __Block_byref_x_VarName struct.
145 NOTE: In order for this to not completely fail on the debugger
146 side, the Debug Information Entry for the variable VarName needs to
147 have a DW_AT_location that tells the debugger how to unwind through
148 the pointers and __Block_byref_x_VarName struct to find the actual
149 value of the variable. The function addBlockByrefType does this. */
151 uint16_t tag = Ty.getTag();
153 if (tag == dwarf::DW_TAG_pointer_type)
154 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
156 DIArray Elements = DICompositeType(subType).getElements();
157 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
158 DIDerivedType DT(Elements.getElement(i));
159 if (getName() == DT.getName())
160 return (resolve(DT.getTypeDerivedFrom()));
166 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
167 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
168 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
169 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
171 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
172 : Asm(A), MMI(Asm->MMI), FirstCU(nullptr), PrevLabel(nullptr),
174 InfoHolder(A, *this, "info_string", DIEValueAllocator),
175 UsedNonDefaultText(false),
176 SkeletonHolder(A, *this, "skel_string", DIEValueAllocator),
177 IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
178 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
179 dwarf::DW_FORM_data4)),
180 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
181 dwarf::DW_FORM_data4)),
182 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
183 dwarf::DW_FORM_data4)),
184 AccelTypes(TypeAtoms) {
186 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = nullptr;
187 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = nullptr;
188 DwarfLineSectionSym = nullptr;
189 DwarfAddrSectionSym = nullptr;
190 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = nullptr;
191 FunctionBeginSym = FunctionEndSym = nullptr;
195 // Turn on accelerator tables for Darwin by default, pubnames by
196 // default for non-Darwin, and handle split dwarf.
197 if (DwarfAccelTables == Default)
198 HasDwarfAccelTables = IsDarwin;
200 HasDwarfAccelTables = DwarfAccelTables == Enable;
202 if (SplitDwarf == Default)
203 HasSplitDwarf = false;
205 HasSplitDwarf = SplitDwarf == Enable;
207 if (DwarfPubSections == Default)
208 HasDwarfPubSections = !IsDarwin;
210 HasDwarfPubSections = DwarfPubSections == Enable;
212 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
213 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
214 : MMI->getModule()->getDwarfVersion();
216 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
219 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
224 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
225 DwarfDebug::~DwarfDebug() { }
227 // Switch to the specified MCSection and emit an assembler
228 // temporary label to it if SymbolStem is specified.
229 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
230 const char *SymbolStem = nullptr) {
231 Asm->OutStreamer.SwitchSection(Section);
235 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
236 Asm->OutStreamer.EmitLabel(TmpSym);
240 static bool isObjCClass(StringRef Name) {
241 return Name.startswith("+") || Name.startswith("-");
244 static bool hasObjCCategory(StringRef Name) {
245 if (!isObjCClass(Name))
248 return Name.find(") ") != StringRef::npos;
251 static void getObjCClassCategory(StringRef In, StringRef &Class,
252 StringRef &Category) {
253 if (!hasObjCCategory(In)) {
254 Class = In.slice(In.find('[') + 1, In.find(' '));
259 Class = In.slice(In.find('[') + 1, In.find('('));
260 Category = In.slice(In.find('[') + 1, In.find(' '));
264 static StringRef getObjCMethodName(StringRef In) {
265 return In.slice(In.find(' ') + 1, In.find(']'));
268 // Helper for sorting sections into a stable output order.
269 static bool SectionSort(const MCSection *A, const MCSection *B) {
270 std::string LA = (A ? A->getLabelBeginName() : "");
271 std::string LB = (B ? B->getLabelBeginName() : "");
275 // Add the various names to the Dwarf accelerator table names.
276 // TODO: Determine whether or not we should add names for programs
277 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
278 // is only slightly different than the lookup of non-standard ObjC names.
279 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
280 if (!SP.isDefinition())
282 addAccelName(SP.getName(), Die);
284 // If the linkage name is different than the name, go ahead and output
285 // that as well into the name table.
286 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
287 addAccelName(SP.getLinkageName(), Die);
289 // If this is an Objective-C selector name add it to the ObjC accelerator
291 if (isObjCClass(SP.getName())) {
292 StringRef Class, Category;
293 getObjCClassCategory(SP.getName(), Class, Category);
294 addAccelObjC(Class, Die);
296 addAccelObjC(Category, Die);
297 // Also add the base method name to the name table.
298 addAccelName(getObjCMethodName(SP.getName()), Die);
302 /// isSubprogramContext - Return true if Context is either a subprogram
303 /// or another context nested inside a subprogram.
304 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
307 DIDescriptor D(Context);
308 if (D.isSubprogram())
311 return isSubprogramContext(resolve(DIType(Context).getContext()));
315 /// Check whether we should create a DIE for the given Scope, return true
316 /// if we don't create a DIE (the corresponding DIE is null).
317 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
318 if (Scope->isAbstractScope())
321 // We don't create a DIE if there is no Range.
322 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
326 if (Ranges.size() > 1)
329 // We don't create a DIE if we have a single Range and the end label
331 return !getLabelAfterInsn(Ranges.front().second);
334 void DwarfDebug::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
335 assert(Scope && Scope->getScopeNode());
336 assert(Scope->isAbstractScope());
337 assert(!Scope->getInlinedAt());
339 const MDNode *SP = Scope->getScopeNode();
341 DIE *&AbsDef = AbstractSPDies[SP];
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 AbsDef = &SPMap[SP]->constructAbstractSubprogramScopeDIE(Scope);
352 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
353 if (!GenerateGnuPubSections)
356 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
359 // Create new DwarfCompileUnit for the given metadata node with tag
360 // DW_TAG_compile_unit.
361 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
362 StringRef FN = DIUnit.getFilename();
363 CompilationDir = DIUnit.getDirectory();
365 auto OwnedUnit = make_unique<DwarfCompileUnit>(
366 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
367 DwarfCompileUnit &NewCU = *OwnedUnit;
368 DIE &Die = NewCU.getUnitDie();
369 InfoHolder.addUnit(std::move(OwnedUnit));
371 // LTO with assembly output shares a single line table amongst multiple CUs.
372 // To avoid the compilation directory being ambiguous, let the line table
373 // explicitly describe the directory of all files, never relying on the
374 // compilation directory.
375 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
376 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
377 NewCU.getUniqueID(), CompilationDir);
379 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
380 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
381 DIUnit.getLanguage());
382 NewCU.addString(Die, dwarf::DW_AT_name, FN);
384 if (!useSplitDwarf()) {
385 NewCU.initStmtList(DwarfLineSectionSym);
387 // If we're using split dwarf the compilation dir is going to be in the
388 // skeleton CU and so we don't need to duplicate it here.
389 if (!CompilationDir.empty())
390 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
392 addGnuPubAttributes(NewCU, Die);
395 if (DIUnit.isOptimized())
396 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
398 StringRef Flags = DIUnit.getFlags();
400 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
402 if (unsigned RVer = DIUnit.getRunTimeVersion())
403 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
404 dwarf::DW_FORM_data1, RVer);
409 if (useSplitDwarf()) {
410 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
411 DwarfInfoDWOSectionSym);
412 NewCU.setSkeleton(constructSkeletonCU(NewCU));
414 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
415 DwarfInfoSectionSym);
417 CUMap.insert(std::make_pair(DIUnit, &NewCU));
418 CUDieMap.insert(std::make_pair(&Die, &NewCU));
422 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
424 DIImportedEntity Module(N);
425 assert(Module.Verify());
426 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
427 D->addChild(TheCU.constructImportedEntityDIE(Module));
430 // Emit all Dwarf sections that should come prior to the content. Create
431 // global DIEs and emit initial debug info sections. This is invoked by
432 // the target AsmPrinter.
433 void DwarfDebug::beginModule() {
434 if (DisableDebugInfoPrinting)
437 const Module *M = MMI->getModule();
439 FunctionDIs = makeSubprogramMap(*M);
441 // If module has named metadata anchors then use them, otherwise scan the
442 // module using debug info finder to collect debug info.
443 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
446 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
448 // Emit initial sections so we can reference labels later.
451 SingleCU = CU_Nodes->getNumOperands() == 1;
453 for (MDNode *N : CU_Nodes->operands()) {
454 DICompileUnit CUNode(N);
455 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
456 DIArray ImportedEntities = CUNode.getImportedEntities();
457 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
458 ScopesWithImportedEntities.push_back(std::make_pair(
459 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
460 ImportedEntities.getElement(i)));
461 std::sort(ScopesWithImportedEntities.begin(),
462 ScopesWithImportedEntities.end(), less_first());
463 DIArray GVs = CUNode.getGlobalVariables();
464 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
465 CU.getOrCreateGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
466 DIArray SPs = CUNode.getSubprograms();
467 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
468 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
469 DIArray EnumTypes = CUNode.getEnumTypes();
470 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
471 DIType Ty(EnumTypes.getElement(i));
472 // The enum types array by design contains pointers to
473 // MDNodes rather than DIRefs. Unique them here.
474 DIType UniqueTy(resolve(Ty.getRef()));
475 CU.getOrCreateTypeDIE(UniqueTy);
477 DIArray RetainedTypes = CUNode.getRetainedTypes();
478 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
479 DIType Ty(RetainedTypes.getElement(i));
480 // The retained types array by design contains pointers to
481 // MDNodes rather than DIRefs. Unique them here.
482 DIType UniqueTy(resolve(Ty.getRef()));
483 CU.getOrCreateTypeDIE(UniqueTy);
485 // Emit imported_modules last so that the relevant context is already
487 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
488 constructAndAddImportedEntityDIE(CU, ImportedEntities.getElement(i));
491 // Tell MMI that we have debug info.
492 MMI->setDebugInfoAvailability(true);
494 // Prime section data.
495 SectionMap[Asm->getObjFileLowering().getTextSection()];
498 void DwarfDebug::finishVariableDefinitions() {
499 for (const auto &Var : ConcreteVariables) {
500 DIE *VariableDie = Var->getDIE();
502 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
503 // in the ConcreteVariables list, rather than looking it up again here.
504 // DIE::getUnit isn't simple - it walks parent pointers, etc.
505 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
507 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
508 if (AbsVar && AbsVar->getDIE()) {
509 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
512 Unit->applyVariableAttributes(*Var, *VariableDie);
516 void DwarfDebug::finishSubprogramDefinitions() {
517 for (const auto &P : SPMap)
518 P.second->finishSubprogramDefinition(DISubprogram(P.first));
522 // Collect info for variables that were optimized out.
523 void DwarfDebug::collectDeadVariables() {
524 const Module *M = MMI->getModule();
526 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
527 for (MDNode *N : CU_Nodes->operands()) {
528 DICompileUnit TheCU(N);
529 // Construct subprogram DIE and add variables DIEs.
530 DwarfCompileUnit *SPCU =
531 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
532 assert(SPCU && "Unable to find Compile Unit!");
533 DIArray Subprograms = TheCU.getSubprograms();
534 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
535 DISubprogram SP(Subprograms.getElement(i));
536 if (ProcessedSPNodes.count(SP) != 0)
538 assert(SP.isSubprogram() &&
539 "CU's subprogram list contains a non-subprogram");
540 assert(SP.isDefinition() &&
541 "CU's subprogram list contains a subprogram declaration");
542 DIArray Variables = SP.getVariables();
543 if (Variables.getNumElements() == 0)
546 DIE *SPDIE = AbstractSPDies.lookup(SP);
548 SPDIE = SPCU->getDIE(SP);
550 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
551 DIVariable DV(Variables.getElement(vi));
552 assert(DV.isVariable());
553 DbgVariable NewVar(DV, DIExpression(nullptr), this);
554 auto VariableDie = SPCU->constructVariableDIE(NewVar);
555 SPCU->applyVariableAttributes(NewVar, *VariableDie);
556 SPDIE->addChild(std::move(VariableDie));
563 void DwarfDebug::finalizeModuleInfo() {
564 finishSubprogramDefinitions();
566 finishVariableDefinitions();
568 // Collect info for variables that were optimized out.
569 collectDeadVariables();
571 // Handle anything that needs to be done on a per-unit basis after
572 // all other generation.
573 for (const auto &TheU : getUnits()) {
574 // Emit DW_AT_containing_type attribute to connect types with their
575 // vtable holding type.
576 TheU->constructContainingTypeDIEs();
578 // Add CU specific attributes if we need to add any.
579 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
580 // If we're splitting the dwarf out now that we've got the entire
581 // CU then add the dwo id to it.
582 DwarfCompileUnit *SkCU =
583 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
584 if (useSplitDwarf()) {
585 // Emit a unique identifier for this CU.
586 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
587 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
588 dwarf::DW_FORM_data8, ID);
589 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
590 dwarf::DW_FORM_data8, ID);
592 // We don't keep track of which addresses are used in which CU so this
593 // is a bit pessimistic under LTO.
594 if (!AddrPool.isEmpty())
595 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_addr_base,
596 DwarfAddrSectionSym, DwarfAddrSectionSym);
597 if (!TheU->getRangeLists().empty())
598 SkCU->addSectionLabel(
599 SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
600 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
603 // If we have code split among multiple sections or non-contiguous
604 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
605 // remain in the .o file, otherwise add a DW_AT_low_pc.
606 // FIXME: We should use ranges allow reordering of code ala
607 // .subsections_via_symbols in mach-o. This would mean turning on
608 // ranges for all subprogram DIEs for mach-o.
609 DwarfCompileUnit &U =
610 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
611 unsigned NumRanges = TheU->getRanges().size();
614 U.addSectionLabel(U.getUnitDie(), dwarf::DW_AT_ranges,
615 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
616 DwarfDebugRangeSectionSym);
618 // A DW_AT_low_pc attribute may also be specified in combination with
619 // DW_AT_ranges to specify the default base address for use in
620 // location lists (see Section 2.6.2) and range lists (see Section
622 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
625 RangeSpan &Range = TheU->getRanges().back();
626 U.attachLowHighPC(U.getUnitDie(), Range.getStart(), Range.getEnd());
632 // Compute DIE offsets and sizes.
633 InfoHolder.computeSizeAndOffsets();
635 SkeletonHolder.computeSizeAndOffsets();
638 void DwarfDebug::endSections() {
639 // Filter labels by section.
640 for (const SymbolCU &SCU : ArangeLabels) {
641 if (SCU.Sym->isInSection()) {
642 // Make a note of this symbol and it's section.
643 const MCSection *Section = &SCU.Sym->getSection();
644 if (!Section->getKind().isMetadata())
645 SectionMap[Section].push_back(SCU);
647 // Some symbols (e.g. common/bss on mach-o) can have no section but still
648 // appear in the output. This sucks as we rely on sections to build
649 // arange spans. We can do it without, but it's icky.
650 SectionMap[nullptr].push_back(SCU);
654 // Build a list of sections used.
655 std::vector<const MCSection *> Sections;
656 for (const auto &it : SectionMap) {
657 const MCSection *Section = it.first;
658 Sections.push_back(Section);
661 // Sort the sections into order.
662 // This is only done to ensure consistent output order across different runs.
663 std::sort(Sections.begin(), Sections.end(), SectionSort);
665 // Add terminating symbols for each section.
666 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
667 const MCSection *Section = Sections[ID];
668 MCSymbol *Sym = nullptr;
671 // We can't call MCSection::getLabelEndName, as it's only safe to do so
672 // if we know the section name up-front. For user-created sections, the
673 // resulting label may not be valid to use as a label. (section names can
674 // use a greater set of characters on some systems)
675 Sym = Asm->GetTempSymbol("debug_end", ID);
676 Asm->OutStreamer.SwitchSection(Section);
677 Asm->OutStreamer.EmitLabel(Sym);
680 // Insert a final terminator.
681 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
685 // Emit all Dwarf sections that should come after the content.
686 void DwarfDebug::endModule() {
687 assert(CurFn == nullptr);
688 assert(CurMI == nullptr);
693 // End any existing sections.
694 // TODO: Does this need to happen?
697 // Finalize the debug info for the module.
698 finalizeModuleInfo();
702 // Emit all the DIEs into a debug info section.
705 // Corresponding abbreviations into a abbrev section.
708 // Emit info into a debug aranges section.
709 if (GenerateARangeSection)
712 // Emit info into a debug ranges section.
715 if (useSplitDwarf()) {
718 emitDebugAbbrevDWO();
721 // Emit DWO addresses.
722 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
724 // Emit info into a debug loc section.
727 // Emit info into the dwarf accelerator table sections.
728 if (useDwarfAccelTables()) {
731 emitAccelNamespaces();
735 // Emit the pubnames and pubtypes sections if requested.
736 if (HasDwarfPubSections) {
737 emitDebugPubNames(GenerateGnuPubSections);
738 emitDebugPubTypes(GenerateGnuPubSections);
743 AbstractVariables.clear();
745 // Reset these for the next Module if we have one.
749 // Find abstract variable, if any, associated with Var.
750 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
751 DIVariable &Cleansed) {
752 LLVMContext &Ctx = DV->getContext();
753 // More then one inlined variable corresponds to one abstract variable.
754 // FIXME: This duplication of variables when inlining should probably be
755 // removed. It's done to allow each DIVariable to describe its location
756 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
757 // make it accurate then remove this duplication/cleansing stuff.
758 Cleansed = cleanseInlinedVariable(DV, Ctx);
759 auto I = AbstractVariables.find(Cleansed);
760 if (I != AbstractVariables.end())
761 return I->second.get();
765 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
767 return getExistingAbstractVariable(DV, Cleansed);
770 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
771 LexicalScope *Scope) {
772 auto AbsDbgVariable = make_unique<DbgVariable>(Var, DIExpression(), this);
773 addNonArgumentScopeVariable(Scope, AbsDbgVariable.get());
774 AbstractVariables[Var] = std::move(AbsDbgVariable);
777 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
778 const MDNode *ScopeNode) {
779 DIVariable Cleansed = DV;
780 if (getExistingAbstractVariable(DV, Cleansed))
783 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
787 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
788 const MDNode *ScopeNode) {
789 DIVariable Cleansed = DV;
790 if (getExistingAbstractVariable(DV, Cleansed))
793 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
794 createAbstractVariable(Cleansed, Scope);
797 // Collect variable information from side table maintained by MMI.
798 void DwarfDebug::collectVariableInfoFromMMITable(
799 SmallPtrSetImpl<const MDNode *> &Processed) {
800 for (const auto &VI : MMI->getVariableDbgInfo()) {
803 Processed.insert(VI.Var);
804 DIVariable DV(VI.Var);
805 DIExpression Expr(VI.Expr);
806 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
808 // If variable scope is not found then skip this variable.
812 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
813 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, Expr, this));
814 DbgVariable *RegVar = ConcreteVariables.back().get();
815 RegVar->setFrameIndex(VI.Slot);
816 addScopeVariable(Scope, RegVar);
820 // Get .debug_loc entry for the instruction range starting at MI.
821 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
822 const MDNode *Expr = MI->getDebugExpression();
823 const MDNode *Var = MI->getDebugVariable();
825 assert(MI->getNumOperands() == 4);
826 if (MI->getOperand(0).isReg()) {
827 MachineLocation MLoc;
828 // If the second operand is an immediate, this is a
829 // register-indirect address.
830 if (!MI->getOperand(1).isImm())
831 MLoc.set(MI->getOperand(0).getReg());
833 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
834 return DebugLocEntry::Value(Var, Expr, MLoc);
836 if (MI->getOperand(0).isImm())
837 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getImm());
838 if (MI->getOperand(0).isFPImm())
839 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getFPImm());
840 if (MI->getOperand(0).isCImm())
841 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getCImm());
843 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
846 /// Determine whether two variable pieces overlap.
847 static bool piecesOverlap(DIExpression P1, DIExpression P2) {
848 if (!P1.isVariablePiece() || !P2.isVariablePiece())
850 unsigned l1 = P1.getPieceOffset();
851 unsigned l2 = P2.getPieceOffset();
852 unsigned r1 = l1 + P1.getPieceSize();
853 unsigned r2 = l2 + P2.getPieceSize();
854 // True where [l1,r1[ and [r1,r2[ overlap.
855 return (l1 < r2) && (l2 < r1);
858 /// Build the location list for all DBG_VALUEs in the function that
859 /// describe the same variable. If the ranges of several independent
860 /// pieces of the same variable overlap partially, split them up and
861 /// combine the ranges. The resulting DebugLocEntries are will have
862 /// strict monotonically increasing begin addresses and will never
867 // Ranges History [var, loc, piece ofs size]
868 // 0 | [x, (reg0, piece 0, 32)]
869 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
871 // 3 | [clobber reg0]
872 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
876 // [0-1] [x, (reg0, piece 0, 32)]
877 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
878 // [3-4] [x, (reg1, piece 32, 32)]
879 // [4- ] [x, (mem, piece 0, 64)]
881 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
882 const DbgValueHistoryMap::InstrRanges &Ranges) {
883 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
885 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
886 const MachineInstr *Begin = I->first;
887 const MachineInstr *End = I->second;
888 assert(Begin->isDebugValue() && "Invalid History entry");
890 // Check if a variable is inaccessible in this range.
891 if (Begin->getNumOperands() > 1 &&
892 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
897 // If this piece overlaps with any open ranges, truncate them.
898 DIExpression DIExpr = Begin->getDebugExpression();
899 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
900 [&](DebugLocEntry::Value R) {
901 return piecesOverlap(DIExpr, R.getExpression());
903 OpenRanges.erase(Last, OpenRanges.end());
905 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
906 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
908 const MCSymbol *EndLabel;
910 EndLabel = getLabelAfterInsn(End);
911 else if (std::next(I) == Ranges.end())
912 EndLabel = FunctionEndSym;
914 EndLabel = getLabelBeforeInsn(std::next(I)->first);
915 assert(EndLabel && "Forgot label after instruction ending a range!");
917 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
919 auto Value = getDebugLocValue(Begin);
920 DebugLocEntry Loc(StartLabel, EndLabel, Value);
921 bool couldMerge = false;
923 // If this is a piece, it may belong to the current DebugLocEntry.
924 if (DIExpr.isVariablePiece()) {
925 // Add this value to the list of open ranges.
926 OpenRanges.push_back(Value);
928 // Attempt to add the piece to the last entry.
929 if (!DebugLoc.empty())
930 if (DebugLoc.back().MergeValues(Loc))
935 // Need to add a new DebugLocEntry. Add all values from still
936 // valid non-overlapping pieces.
937 if (OpenRanges.size())
938 Loc.addValues(OpenRanges);
940 DebugLoc.push_back(std::move(Loc));
943 // Attempt to coalesce the ranges of two otherwise identical
945 auto CurEntry = DebugLoc.rbegin();
946 auto PrevEntry = std::next(CurEntry);
947 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
951 dbgs() << CurEntry->getValues().size() << " Values:\n";
952 for (auto Value : CurEntry->getValues()) {
953 Value.getVariable()->dump();
954 Value.getExpression()->dump();
962 // Find variables for each lexical scope.
964 DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU, DISubprogram SP,
965 SmallPtrSetImpl<const MDNode *> &Processed) {
966 // Grab the variable info that was squirreled away in the MMI side-table.
967 collectVariableInfoFromMMITable(Processed);
969 for (const auto &I : DbgValues) {
970 DIVariable DV(I.first);
971 if (Processed.count(DV))
974 // Instruction ranges, specifying where DV is accessible.
975 const auto &Ranges = I.second;
979 LexicalScope *Scope = nullptr;
980 if (MDNode *IA = DV.getInlinedAt()) {
981 DebugLoc DL = DebugLoc::getFromDILocation(IA);
982 Scope = LScopes.findInlinedScope(DebugLoc::get(
983 DL.getLine(), DL.getCol(), DV.getContext(), IA));
985 Scope = LScopes.findLexicalScope(DV.getContext());
986 // If variable scope is not found then skip this variable.
990 Processed.insert(DV);
991 const MachineInstr *MInsn = Ranges.front().first;
992 assert(MInsn->isDebugValue() && "History must begin with debug value");
993 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
994 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
995 DbgVariable *RegVar = ConcreteVariables.back().get();
996 addScopeVariable(Scope, RegVar);
998 // Check if the first DBG_VALUE is valid for the rest of the function.
999 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1002 // Handle multiple DBG_VALUE instructions describing one variable.
1003 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1005 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1006 DebugLocList &LocList = DotDebugLocEntries.back();
1007 LocList.CU = &TheCU;
1009 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1011 // Build the location list for this variable.
1012 buildLocationList(LocList.List, Ranges);
1015 // Collect info for variables that were optimized out.
1016 DIArray Variables = SP.getVariables();
1017 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1018 DIVariable DV(Variables.getElement(i));
1019 assert(DV.isVariable());
1020 if (!Processed.insert(DV))
1022 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1023 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1024 DIExpression NoExpr;
1025 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, NoExpr, this));
1026 addScopeVariable(Scope, ConcreteVariables.back().get());
1031 // Return Label preceding the instruction.
1032 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1033 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1034 assert(Label && "Didn't insert label before instruction");
1038 // Return Label immediately following the instruction.
1039 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1040 return LabelsAfterInsn.lookup(MI);
1043 // Process beginning of an instruction.
1044 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1045 assert(CurMI == nullptr);
1047 // Check if source location changes, but ignore DBG_VALUE locations.
1048 if (!MI->isDebugValue()) {
1049 DebugLoc DL = MI->getDebugLoc();
1050 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1053 if (DL == PrologEndLoc) {
1054 Flags |= DWARF2_FLAG_PROLOGUE_END;
1055 PrologEndLoc = DebugLoc();
1057 if (PrologEndLoc.isUnknown())
1058 Flags |= DWARF2_FLAG_IS_STMT;
1060 if (!DL.isUnknown()) {
1061 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1062 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1064 recordSourceLine(0, 0, nullptr, 0);
1068 // Insert labels where requested.
1069 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1070 LabelsBeforeInsn.find(MI);
1073 if (I == LabelsBeforeInsn.end())
1076 // Label already assigned.
1081 PrevLabel = MMI->getContext().CreateTempSymbol();
1082 Asm->OutStreamer.EmitLabel(PrevLabel);
1084 I->second = PrevLabel;
1087 // Process end of an instruction.
1088 void DwarfDebug::endInstruction() {
1089 assert(CurMI != nullptr);
1090 // Don't create a new label after DBG_VALUE instructions.
1091 // They don't generate code.
1092 if (!CurMI->isDebugValue())
1093 PrevLabel = nullptr;
1095 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1096 LabelsAfterInsn.find(CurMI);
1100 if (I == LabelsAfterInsn.end())
1103 // Label already assigned.
1107 // We need a label after this instruction.
1109 PrevLabel = MMI->getContext().CreateTempSymbol();
1110 Asm->OutStreamer.EmitLabel(PrevLabel);
1112 I->second = PrevLabel;
1115 // Each LexicalScope has first instruction and last instruction to mark
1116 // beginning and end of a scope respectively. Create an inverse map that list
1117 // scopes starts (and ends) with an instruction. One instruction may start (or
1118 // end) multiple scopes. Ignore scopes that are not reachable.
1119 void DwarfDebug::identifyScopeMarkers() {
1120 SmallVector<LexicalScope *, 4> WorkList;
1121 WorkList.push_back(LScopes.getCurrentFunctionScope());
1122 while (!WorkList.empty()) {
1123 LexicalScope *S = WorkList.pop_back_val();
1125 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1126 if (!Children.empty())
1127 WorkList.append(Children.begin(), Children.end());
1129 if (S->isAbstractScope())
1132 for (const InsnRange &R : S->getRanges()) {
1133 assert(R.first && "InsnRange does not have first instruction!");
1134 assert(R.second && "InsnRange does not have second instruction!");
1135 requestLabelBeforeInsn(R.first);
1136 requestLabelAfterInsn(R.second);
1141 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1142 // First known non-DBG_VALUE and non-frame setup location marks
1143 // the beginning of the function body.
1144 for (const auto &MBB : *MF)
1145 for (const auto &MI : MBB)
1146 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1147 !MI.getDebugLoc().isUnknown())
1148 return MI.getDebugLoc();
1152 // Gather pre-function debug information. Assumes being called immediately
1153 // after the function entry point has been emitted.
1154 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1157 // If there's no debug info for the function we're not going to do anything.
1158 if (!MMI->hasDebugInfo())
1161 auto DI = FunctionDIs.find(MF->getFunction());
1162 if (DI == FunctionDIs.end())
1165 // Grab the lexical scopes for the function, if we don't have any of those
1166 // then we're not going to be able to do anything.
1167 LScopes.initialize(*MF);
1168 if (LScopes.empty())
1171 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1173 // Make sure that each lexical scope will have a begin/end label.
1174 identifyScopeMarkers();
1176 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1177 // belongs to so that we add to the correct per-cu line table in the
1179 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1180 // FnScope->getScopeNode() and DI->second should represent the same function,
1181 // though they may not be the same MDNode due to inline functions merged in
1182 // LTO where the debug info metadata still differs (either due to distinct
1183 // written differences - two versions of a linkonce_odr function
1184 // written/copied into two separate files, or some sub-optimal metadata that
1185 // isn't structurally identical (see: file path/name info from clang, which
1186 // includes the directory of the cpp file being built, even when the file name
1187 // is absolute (such as an <> lookup header)))
1188 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1189 assert(TheCU && "Unable to find compile unit!");
1190 if (Asm->OutStreamer.hasRawTextSupport())
1191 // Use a single line table if we are generating assembly.
1192 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1194 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1196 // Emit a label for the function so that we have a beginning address.
1197 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1198 // Assumes in correct section after the entry point.
1199 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1201 // Calculate history for local variables.
1202 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1205 // Request labels for the full history.
1206 for (const auto &I : DbgValues) {
1207 const auto &Ranges = I.second;
1211 // The first mention of a function argument gets the FunctionBeginSym
1212 // label, so arguments are visible when breaking at function entry.
1213 DIVariable DIVar(Ranges.front().first->getDebugVariable());
1214 if (DIVar.isVariable() && DIVar.getTag() == dwarf::DW_TAG_arg_variable &&
1215 getDISubprogram(DIVar.getContext()).describes(MF->getFunction())) {
1216 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1217 if (Ranges.front().first->getDebugExpression().isVariablePiece()) {
1218 // Mark all non-overlapping initial pieces.
1219 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1220 DIExpression Piece = I->first->getDebugExpression();
1221 if (std::all_of(Ranges.begin(), I,
1222 [&](DbgValueHistoryMap::InstrRange Pred) {
1223 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1225 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1232 for (const auto &Range : Ranges) {
1233 requestLabelBeforeInsn(Range.first);
1235 requestLabelAfterInsn(Range.second);
1239 PrevInstLoc = DebugLoc();
1240 PrevLabel = FunctionBeginSym;
1242 // Record beginning of function.
1243 PrologEndLoc = findPrologueEndLoc(MF);
1244 if (!PrologEndLoc.isUnknown()) {
1245 DebugLoc FnStartDL =
1246 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1248 FnStartDL.getLine(), FnStartDL.getCol(),
1249 FnStartDL.getScope(MF->getFunction()->getContext()),
1250 // We'd like to list the prologue as "not statements" but GDB behaves
1251 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1252 DWARF2_FLAG_IS_STMT);
1256 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1257 if (InfoHolder.addCurrentFnArgument(Var, LS))
1259 addNonArgumentScopeVariable(LS, Var);
1262 void DwarfDebug::addNonArgumentScopeVariable(LexicalScope *LS,
1264 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1265 DIVariable DV = Var->getVariable();
1266 // Variables with positive arg numbers are parameters.
1267 if (unsigned ArgNum = DV.getArgNumber()) {
1268 // Keep all parameters in order at the start of the variable list to ensure
1269 // function types are correct (no out-of-order parameters)
1271 // This could be improved by only doing it for optimized builds (unoptimized
1272 // builds have the right order to begin with), searching from the back (this
1273 // would catch the unoptimized case quickly), or doing a binary search
1274 // rather than linear search.
1275 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1276 while (I != Vars.end()) {
1277 unsigned CurNum = (*I)->getVariable().getArgNumber();
1278 // A local (non-parameter) variable has been found, insert immediately
1282 // A later indexed parameter has been found, insert immediately before it.
1283 if (CurNum > ArgNum)
1287 Vars.insert(I, Var);
1291 Vars.push_back(Var);
1294 // Gather and emit post-function debug information.
1295 void DwarfDebug::endFunction(const MachineFunction *MF) {
1296 assert(CurFn == MF &&
1297 "endFunction should be called with the same function as beginFunction");
1299 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1300 !FunctionDIs.count(MF->getFunction())) {
1301 // If we don't have a lexical scope for this function then there will
1302 // be a hole in the range information. Keep note of this by setting the
1303 // previously used section to nullptr.
1309 // Define end label for subprogram.
1310 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1311 // Assumes in correct section after the entry point.
1312 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1314 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1315 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1317 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1318 DISubprogram SP(FnScope->getScopeNode());
1319 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1321 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1322 collectVariableInfo(TheCU, SP, ProcessedVars);
1324 // Add the range of this function to the list of ranges for the CU.
1325 TheCU.addRange(RangeSpan(FunctionBeginSym, FunctionEndSym));
1327 // Under -gmlt, skip building the subprogram if there are no inlined
1328 // subroutines inside it.
1329 if (TheCU.getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly &&
1330 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1331 assert(ScopeVariables.empty());
1332 assert(CurrentFnArguments.empty());
1333 assert(DbgValues.empty());
1334 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1335 // by a -gmlt CU. Add a test and remove this assertion.
1336 assert(AbstractVariables.empty());
1337 LabelsBeforeInsn.clear();
1338 LabelsAfterInsn.clear();
1339 PrevLabel = nullptr;
1345 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1347 // Construct abstract scopes.
1348 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1349 DISubprogram SP(AScope->getScopeNode());
1350 assert(SP.isSubprogram());
1351 // Collect info for variables that were optimized out.
1352 DIArray Variables = SP.getVariables();
1353 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1354 DIVariable DV(Variables.getElement(i));
1355 assert(DV && DV.isVariable());
1356 if (!ProcessedVars.insert(DV))
1358 ensureAbstractVariableIsCreated(DV, DV.getContext());
1359 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1360 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1362 constructAbstractSubprogramScopeDIE(AScope);
1365 TheCU.constructSubprogramScopeDIE(FnScope);
1368 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1369 // DbgVariables except those that are also in AbstractVariables (since they
1370 // can be used cross-function)
1371 ScopeVariables.clear();
1372 CurrentFnArguments.clear();
1374 LabelsBeforeInsn.clear();
1375 LabelsAfterInsn.clear();
1376 PrevLabel = nullptr;
1380 // Register a source line with debug info. Returns the unique label that was
1381 // emitted and which provides correspondence to the source line list.
1382 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1387 unsigned Discriminator = 0;
1388 if (DIScope Scope = DIScope(S)) {
1389 assert(Scope.isScope());
1390 Fn = Scope.getFilename();
1391 Dir = Scope.getDirectory();
1392 if (Scope.isLexicalBlockFile())
1393 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1395 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1396 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1397 .getOrCreateSourceID(Fn, Dir);
1399 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1403 //===----------------------------------------------------------------------===//
1405 //===----------------------------------------------------------------------===//
1407 // Emit initial Dwarf sections with a label at the start of each one.
1408 void DwarfDebug::emitSectionLabels() {
1409 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1411 // Dwarf sections base addresses.
1412 DwarfInfoSectionSym =
1413 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1414 if (useSplitDwarf()) {
1415 DwarfInfoDWOSectionSym =
1416 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1417 DwarfTypesDWOSectionSym =
1418 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1420 DwarfAbbrevSectionSym =
1421 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1422 if (useSplitDwarf())
1423 DwarfAbbrevDWOSectionSym = emitSectionSym(
1424 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1425 if (GenerateARangeSection)
1426 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1428 DwarfLineSectionSym =
1429 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1430 if (GenerateGnuPubSections) {
1431 DwarfGnuPubNamesSectionSym =
1432 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1433 DwarfGnuPubTypesSectionSym =
1434 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1435 } else if (HasDwarfPubSections) {
1436 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1437 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1440 DwarfStrSectionSym =
1441 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1442 if (useSplitDwarf()) {
1443 DwarfStrDWOSectionSym =
1444 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1445 DwarfAddrSectionSym =
1446 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1447 DwarfDebugLocSectionSym =
1448 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1450 DwarfDebugLocSectionSym =
1451 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1452 DwarfDebugRangeSectionSym =
1453 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1456 // Recursively emits a debug information entry.
1457 void DwarfDebug::emitDIE(DIE &Die) {
1458 // Get the abbreviation for this DIE.
1459 const DIEAbbrev &Abbrev = Die.getAbbrev();
1461 // Emit the code (index) for the abbreviation.
1462 if (Asm->isVerbose())
1463 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1464 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1465 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1466 dwarf::TagString(Abbrev.getTag()));
1467 Asm->EmitULEB128(Abbrev.getNumber());
1469 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1470 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1472 // Emit the DIE attribute values.
1473 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1474 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1475 dwarf::Form Form = AbbrevData[i].getForm();
1476 assert(Form && "Too many attributes for DIE (check abbreviation)");
1478 if (Asm->isVerbose()) {
1479 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1480 if (Attr == dwarf::DW_AT_accessibility)
1481 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1482 cast<DIEInteger>(Values[i])->getValue()));
1485 // Emit an attribute using the defined form.
1486 Values[i]->EmitValue(Asm, Form);
1489 // Emit the DIE children if any.
1490 if (Abbrev.hasChildren()) {
1491 for (auto &Child : Die.getChildren())
1494 Asm->OutStreamer.AddComment("End Of Children Mark");
1499 // Emit the debug info section.
1500 void DwarfDebug::emitDebugInfo() {
1501 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1503 Holder.emitUnits(DwarfAbbrevSectionSym);
1506 // Emit the abbreviation section.
1507 void DwarfDebug::emitAbbreviations() {
1508 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1510 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1513 // Emit the last address of the section and the end of the line matrix.
1514 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1515 // Define last address of section.
1516 Asm->OutStreamer.AddComment("Extended Op");
1519 Asm->OutStreamer.AddComment("Op size");
1520 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1521 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1522 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1524 Asm->OutStreamer.AddComment("Section end label");
1526 Asm->OutStreamer.EmitSymbolValue(
1527 Asm->GetTempSymbol("section_end", SectionEnd),
1528 Asm->getDataLayout().getPointerSize());
1530 // Mark end of matrix.
1531 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1537 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1538 StringRef TableName, StringRef SymName) {
1539 Accel.FinalizeTable(Asm, TableName);
1540 Asm->OutStreamer.SwitchSection(Section);
1541 auto *SectionBegin = Asm->GetTempSymbol(SymName);
1542 Asm->OutStreamer.EmitLabel(SectionBegin);
1544 // Emit the full data.
1545 Accel.Emit(Asm, SectionBegin, &InfoHolder, DwarfStrSectionSym);
1548 // Emit visible names into a hashed accelerator table section.
1549 void DwarfDebug::emitAccelNames() {
1550 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1551 "Names", "names_begin");
1554 // Emit objective C classes and categories into a hashed accelerator table
1556 void DwarfDebug::emitAccelObjC() {
1557 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1558 "ObjC", "objc_begin");
1561 // Emit namespace dies into a hashed accelerator table.
1562 void DwarfDebug::emitAccelNamespaces() {
1563 emitAccel(AccelNamespace,
1564 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1565 "namespac", "namespac_begin");
1568 // Emit type dies into a hashed accelerator table.
1569 void DwarfDebug::emitAccelTypes() {
1570 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1571 "types", "types_begin");
1574 // Public name handling.
1575 // The format for the various pubnames:
1577 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1578 // for the DIE that is named.
1580 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1581 // into the CU and the index value is computed according to the type of value
1582 // for the DIE that is named.
1584 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1585 // it's the offset within the debug_info/debug_types dwo section, however, the
1586 // reference in the pubname header doesn't change.
1588 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1589 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1591 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1593 // We could have a specification DIE that has our most of our knowledge,
1594 // look for that now.
1595 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1597 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1598 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1599 Linkage = dwarf::GIEL_EXTERNAL;
1600 } else if (Die->findAttribute(dwarf::DW_AT_external))
1601 Linkage = dwarf::GIEL_EXTERNAL;
1603 switch (Die->getTag()) {
1604 case dwarf::DW_TAG_class_type:
1605 case dwarf::DW_TAG_structure_type:
1606 case dwarf::DW_TAG_union_type:
1607 case dwarf::DW_TAG_enumeration_type:
1608 return dwarf::PubIndexEntryDescriptor(
1609 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1610 ? dwarf::GIEL_STATIC
1611 : dwarf::GIEL_EXTERNAL);
1612 case dwarf::DW_TAG_typedef:
1613 case dwarf::DW_TAG_base_type:
1614 case dwarf::DW_TAG_subrange_type:
1615 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1616 case dwarf::DW_TAG_namespace:
1617 return dwarf::GIEK_TYPE;
1618 case dwarf::DW_TAG_subprogram:
1619 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1620 case dwarf::DW_TAG_constant:
1621 case dwarf::DW_TAG_variable:
1622 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1623 case dwarf::DW_TAG_enumerator:
1624 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1625 dwarf::GIEL_STATIC);
1627 return dwarf::GIEK_NONE;
1631 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1633 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1634 const MCSection *PSec =
1635 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1636 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1638 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1641 void DwarfDebug::emitDebugPubSection(
1642 bool GnuStyle, const MCSection *PSec, StringRef Name,
1643 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1644 for (const auto &NU : CUMap) {
1645 DwarfCompileUnit *TheU = NU.second;
1647 const auto &Globals = (TheU->*Accessor)();
1649 if (Globals.empty())
1652 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1654 unsigned ID = TheU->getUniqueID();
1656 // Start the dwarf pubnames section.
1657 Asm->OutStreamer.SwitchSection(PSec);
1660 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1661 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
1662 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
1663 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1665 Asm->OutStreamer.EmitLabel(BeginLabel);
1667 Asm->OutStreamer.AddComment("DWARF Version");
1668 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1670 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1671 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
1673 Asm->OutStreamer.AddComment("Compilation Unit Length");
1674 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
1676 // Emit the pubnames for this compilation unit.
1677 for (const auto &GI : Globals) {
1678 const char *Name = GI.getKeyData();
1679 const DIE *Entity = GI.second;
1681 Asm->OutStreamer.AddComment("DIE offset");
1682 Asm->EmitInt32(Entity->getOffset());
1685 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1686 Asm->OutStreamer.AddComment(
1687 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1688 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1689 Asm->EmitInt8(Desc.toBits());
1692 Asm->OutStreamer.AddComment("External Name");
1693 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1696 Asm->OutStreamer.AddComment("End Mark");
1698 Asm->OutStreamer.EmitLabel(EndLabel);
1702 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1703 const MCSection *PSec =
1704 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1705 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1707 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
1710 // Emit visible names into a debug str section.
1711 void DwarfDebug::emitDebugStr() {
1712 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1713 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1716 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
1717 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
1718 const DITypeIdentifierMap &Map,
1719 ArrayRef<DebugLocEntry::Value> Values) {
1720 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1721 return P.isVariablePiece();
1722 }) && "all values are expected to be pieces");
1723 assert(std::is_sorted(Values.begin(), Values.end()) &&
1724 "pieces are expected to be sorted");
1726 unsigned Offset = 0;
1727 for (auto Piece : Values) {
1728 DIExpression Expr = Piece.getExpression();
1729 unsigned PieceOffset = Expr.getPieceOffset();
1730 unsigned PieceSize = Expr.getPieceSize();
1731 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1732 if (Offset < PieceOffset) {
1733 // The DWARF spec seriously mandates pieces with no locations for gaps.
1734 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
1735 Offset += PieceOffset-Offset;
1738 Offset += PieceSize;
1740 const unsigned SizeOfByte = 8;
1742 DIVariable Var = Piece.getVariable();
1743 assert(!Var.isIndirect() && "indirect address for piece");
1744 unsigned VarSize = Var.getSizeInBits(Map);
1745 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
1746 && "piece is larger than or outside of variable");
1747 assert(PieceSize*SizeOfByte != VarSize
1748 && "piece covers entire variable");
1750 if (Piece.isLocation() && Piece.getLoc().isReg())
1751 Asm->EmitDwarfRegOpPiece(Streamer,
1753 PieceSize*SizeOfByte);
1755 emitDebugLocValue(Streamer, Piece);
1756 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
1762 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1763 const DebugLocEntry &Entry) {
1764 const DebugLocEntry::Value Value = Entry.getValues()[0];
1765 if (Value.isVariablePiece())
1766 // Emit all pieces that belong to the same variable and range.
1767 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
1769 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
1770 emitDebugLocValue(Streamer, Value);
1773 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
1774 const DebugLocEntry::Value &Value) {
1775 DIVariable DV = Value.getVariable();
1777 if (Value.isInt()) {
1778 DIBasicType BTy(resolve(DV.getType()));
1779 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
1780 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
1781 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
1782 Streamer.EmitSLEB128(Value.getInt());
1784 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
1785 Streamer.EmitULEB128(Value.getInt());
1787 } else if (Value.isLocation()) {
1788 MachineLocation Loc = Value.getLoc();
1789 DIExpression Expr = Value.getExpression();
1792 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
1794 // Complex address entry.
1795 unsigned N = Expr.getNumElements();
1797 if (N >= 2 && Expr.getElement(0) == dwarf::DW_OP_plus) {
1798 if (Loc.getOffset()) {
1800 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
1801 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
1802 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
1803 Streamer.EmitSLEB128(Expr.getElement(1));
1805 // If first address element is OpPlus then emit
1806 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
1807 MachineLocation TLoc(Loc.getReg(), Expr.getElement(1));
1808 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
1812 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
1815 // Emit remaining complex address elements.
1816 for (; i < N; ++i) {
1817 uint64_t Element = Expr.getElement(i);
1818 if (Element == dwarf::DW_OP_plus) {
1819 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
1820 Streamer.EmitULEB128(Expr.getElement(++i));
1821 } else if (Element == dwarf::DW_OP_deref) {
1823 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
1824 } else if (Element == dwarf::DW_OP_piece) {
1826 // handled in emitDebugLocEntry.
1828 llvm_unreachable("unknown Opcode found in complex address");
1832 // else ... ignore constant fp. There is not any good way to
1833 // to represent them here in dwarf.
1837 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
1838 Asm->OutStreamer.AddComment("Loc expr size");
1839 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
1840 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
1841 Asm->EmitLabelDifference(end, begin, 2);
1842 Asm->OutStreamer.EmitLabel(begin);
1844 APByteStreamer Streamer(*Asm);
1845 emitDebugLocEntry(Streamer, Entry);
1847 Asm->OutStreamer.EmitLabel(end);
1850 // Emit locations into the debug loc section.
1851 void DwarfDebug::emitDebugLoc() {
1852 // Start the dwarf loc section.
1853 Asm->OutStreamer.SwitchSection(
1854 Asm->getObjFileLowering().getDwarfLocSection());
1855 unsigned char Size = Asm->getDataLayout().getPointerSize();
1856 for (const auto &DebugLoc : DotDebugLocEntries) {
1857 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1858 const DwarfCompileUnit *CU = DebugLoc.CU;
1859 assert(!CU->getRanges().empty());
1860 for (const auto &Entry : DebugLoc.List) {
1861 // Set up the range. This range is relative to the entry point of the
1862 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1863 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1864 if (CU->getRanges().size() == 1) {
1865 // Grab the begin symbol from the first range as our base.
1866 const MCSymbol *Base = CU->getRanges()[0].getStart();
1867 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
1868 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
1870 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
1871 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
1874 emitDebugLocEntryLocation(Entry);
1876 Asm->OutStreamer.EmitIntValue(0, Size);
1877 Asm->OutStreamer.EmitIntValue(0, Size);
1881 void DwarfDebug::emitDebugLocDWO() {
1882 Asm->OutStreamer.SwitchSection(
1883 Asm->getObjFileLowering().getDwarfLocDWOSection());
1884 for (const auto &DebugLoc : DotDebugLocEntries) {
1885 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1886 for (const auto &Entry : DebugLoc.List) {
1887 // Just always use start_length for now - at least that's one address
1888 // rather than two. We could get fancier and try to, say, reuse an
1889 // address we know we've emitted elsewhere (the start of the function?
1890 // The start of the CU or CU subrange that encloses this range?)
1891 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1892 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
1893 Asm->EmitULEB128(idx);
1894 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
1896 emitDebugLocEntryLocation(Entry);
1898 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1903 const MCSymbol *Start, *End;
1906 // Emit a debug aranges section, containing a CU lookup for any
1907 // address we can tie back to a CU.
1908 void DwarfDebug::emitDebugARanges() {
1909 // Start the dwarf aranges section.
1910 Asm->OutStreamer.SwitchSection(
1911 Asm->getObjFileLowering().getDwarfARangesSection());
1913 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
1917 // Build a list of sections used.
1918 std::vector<const MCSection *> Sections;
1919 for (const auto &it : SectionMap) {
1920 const MCSection *Section = it.first;
1921 Sections.push_back(Section);
1924 // Sort the sections into order.
1925 // This is only done to ensure consistent output order across different runs.
1926 std::sort(Sections.begin(), Sections.end(), SectionSort);
1928 // Build a set of address spans, sorted by CU.
1929 for (const MCSection *Section : Sections) {
1930 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
1931 if (List.size() < 2)
1934 // Sort the symbols by offset within the section.
1935 std::sort(List.begin(), List.end(),
1936 [&](const SymbolCU &A, const SymbolCU &B) {
1937 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
1938 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
1940 // Symbols with no order assigned should be placed at the end.
1941 // (e.g. section end labels)
1949 // If we have no section (e.g. common), just write out
1950 // individual spans for each symbol.
1952 for (const SymbolCU &Cur : List) {
1954 Span.Start = Cur.Sym;
1957 Spans[Cur.CU].push_back(Span);
1960 // Build spans between each label.
1961 const MCSymbol *StartSym = List[0].Sym;
1962 for (size_t n = 1, e = List.size(); n < e; n++) {
1963 const SymbolCU &Prev = List[n - 1];
1964 const SymbolCU &Cur = List[n];
1966 // Try and build the longest span we can within the same CU.
1967 if (Cur.CU != Prev.CU) {
1969 Span.Start = StartSym;
1971 Spans[Prev.CU].push_back(Span);
1978 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1980 // Build a list of CUs used.
1981 std::vector<DwarfCompileUnit *> CUs;
1982 for (const auto &it : Spans) {
1983 DwarfCompileUnit *CU = it.first;
1987 // Sort the CU list (again, to ensure consistent output order).
1988 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1989 return A->getUniqueID() < B->getUniqueID();
1992 // Emit an arange table for each CU we used.
1993 for (DwarfCompileUnit *CU : CUs) {
1994 std::vector<ArangeSpan> &List = Spans[CU];
1996 // Emit size of content not including length itself.
1997 unsigned ContentSize =
1998 sizeof(int16_t) + // DWARF ARange version number
1999 sizeof(int32_t) + // Offset of CU in the .debug_info section
2000 sizeof(int8_t) + // Pointer Size (in bytes)
2001 sizeof(int8_t); // Segment Size (in bytes)
2003 unsigned TupleSize = PtrSize * 2;
2005 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2007 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2009 ContentSize += Padding;
2010 ContentSize += (List.size() + 1) * TupleSize;
2012 // For each compile unit, write the list of spans it covers.
2013 Asm->OutStreamer.AddComment("Length of ARange Set");
2014 Asm->EmitInt32(ContentSize);
2015 Asm->OutStreamer.AddComment("DWARF Arange version number");
2016 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2017 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2018 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2019 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2020 Asm->EmitInt8(PtrSize);
2021 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2024 Asm->OutStreamer.EmitFill(Padding, 0xff);
2026 for (const ArangeSpan &Span : List) {
2027 Asm->EmitLabelReference(Span.Start, PtrSize);
2029 // Calculate the size as being from the span start to it's end.
2031 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2033 // For symbols without an end marker (e.g. common), we
2034 // write a single arange entry containing just that one symbol.
2035 uint64_t Size = SymSize[Span.Start];
2039 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2043 Asm->OutStreamer.AddComment("ARange terminator");
2044 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2045 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2049 // Emit visible names into a debug ranges section.
2050 void DwarfDebug::emitDebugRanges() {
2051 // Start the dwarf ranges section.
2052 Asm->OutStreamer.SwitchSection(
2053 Asm->getObjFileLowering().getDwarfRangesSection());
2055 // Size for our labels.
2056 unsigned char Size = Asm->getDataLayout().getPointerSize();
2058 // Grab the specific ranges for the compile units in the module.
2059 for (const auto &I : CUMap) {
2060 DwarfCompileUnit *TheCU = I.second;
2062 // Iterate over the misc ranges for the compile units in the module.
2063 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2064 // Emit our symbol so we can find the beginning of the range.
2065 Asm->OutStreamer.EmitLabel(List.getSym());
2067 for (const RangeSpan &Range : List.getRanges()) {
2068 const MCSymbol *Begin = Range.getStart();
2069 const MCSymbol *End = Range.getEnd();
2070 assert(Begin && "Range without a begin symbol?");
2071 assert(End && "Range without an end symbol?");
2072 if (TheCU->getRanges().size() == 1) {
2073 // Grab the begin symbol from the first range as our base.
2074 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2075 Asm->EmitLabelDifference(Begin, Base, Size);
2076 Asm->EmitLabelDifference(End, Base, Size);
2078 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2079 Asm->OutStreamer.EmitSymbolValue(End, Size);
2083 // And terminate the list with two 0 values.
2084 Asm->OutStreamer.EmitIntValue(0, Size);
2085 Asm->OutStreamer.EmitIntValue(0, Size);
2088 // Now emit a range for the CU itself.
2089 if (TheCU->getRanges().size() > 1) {
2090 Asm->OutStreamer.EmitLabel(
2091 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2092 for (const RangeSpan &Range : TheCU->getRanges()) {
2093 const MCSymbol *Begin = Range.getStart();
2094 const MCSymbol *End = Range.getEnd();
2095 assert(Begin && "Range without a begin symbol?");
2096 assert(End && "Range without an end symbol?");
2097 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2098 Asm->OutStreamer.EmitSymbolValue(End, Size);
2100 // And terminate the list with two 0 values.
2101 Asm->OutStreamer.EmitIntValue(0, Size);
2102 Asm->OutStreamer.EmitIntValue(0, Size);
2107 // DWARF5 Experimental Separate Dwarf emitters.
2109 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2110 std::unique_ptr<DwarfUnit> NewU) {
2111 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2112 U.getCUNode().getSplitDebugFilename());
2114 if (!CompilationDir.empty())
2115 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2117 addGnuPubAttributes(*NewU, Die);
2119 SkeletonHolder.addUnit(std::move(NewU));
2122 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2123 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2124 // DW_AT_addr_base, DW_AT_ranges_base.
2125 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2127 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2128 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2129 DwarfCompileUnit &NewCU = *OwnedUnit;
2130 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2131 DwarfInfoSectionSym);
2133 NewCU.initStmtList(DwarfLineSectionSym);
2135 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2140 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2141 // compile units that would normally be in debug_info.
2142 void DwarfDebug::emitDebugInfoDWO() {
2143 assert(useSplitDwarf() && "No split dwarf debug info?");
2144 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2145 // emit relocations into the dwo file.
2146 InfoHolder.emitUnits(/* AbbrevSymbol */ nullptr);
2149 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2150 // abbreviations for the .debug_info.dwo section.
2151 void DwarfDebug::emitDebugAbbrevDWO() {
2152 assert(useSplitDwarf() && "No split dwarf?");
2153 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2156 void DwarfDebug::emitDebugLineDWO() {
2157 assert(useSplitDwarf() && "No split dwarf?");
2158 Asm->OutStreamer.SwitchSection(
2159 Asm->getObjFileLowering().getDwarfLineDWOSection());
2160 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2163 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2164 // string section and is identical in format to traditional .debug_str
2166 void DwarfDebug::emitDebugStrDWO() {
2167 assert(useSplitDwarf() && "No split dwarf?");
2168 const MCSection *OffSec =
2169 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2170 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2174 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2175 if (!useSplitDwarf())
2178 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2179 return &SplitTypeUnitFileTable;
2182 static uint64_t makeTypeSignature(StringRef Identifier) {
2184 Hash.update(Identifier);
2185 // ... take the least significant 8 bytes and return those. Our MD5
2186 // implementation always returns its results in little endian, swap bytes
2188 MD5::MD5Result Result;
2190 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2193 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2194 StringRef Identifier, DIE &RefDie,
2195 DICompositeType CTy) {
2196 // Fast path if we're building some type units and one has already used the
2197 // address pool we know we're going to throw away all this work anyway, so
2198 // don't bother building dependent types.
2199 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2202 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2204 CU.addDIETypeSignature(RefDie, *TU);
2208 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2209 AddrPool.resetUsedFlag();
2211 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2212 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2213 this, &InfoHolder, getDwoLineTable(CU));
2214 DwarfTypeUnit &NewTU = *OwnedUnit;
2215 DIE &UnitDie = NewTU.getUnitDie();
2217 TypeUnitsUnderConstruction.push_back(
2218 std::make_pair(std::move(OwnedUnit), CTy));
2220 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2223 uint64_t Signature = makeTypeSignature(Identifier);
2224 NewTU.setTypeSignature(Signature);
2226 if (useSplitDwarf())
2227 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2228 DwarfTypesDWOSectionSym);
2230 CU.applyStmtList(UnitDie);
2232 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2235 NewTU.setType(NewTU.createTypeDIE(CTy));
2238 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2239 TypeUnitsUnderConstruction.clear();
2241 // Types referencing entries in the address table cannot be placed in type
2243 if (AddrPool.hasBeenUsed()) {
2245 // Remove all the types built while building this type.
2246 // This is pessimistic as some of these types might not be dependent on
2247 // the type that used an address.
2248 for (const auto &TU : TypeUnitsToAdd)
2249 DwarfTypeUnits.erase(TU.second);
2251 // Construct this type in the CU directly.
2252 // This is inefficient because all the dependent types will be rebuilt
2253 // from scratch, including building them in type units, discovering that
2254 // they depend on addresses, throwing them out and rebuilding them.
2255 CU.constructTypeDIE(RefDie, CTy);
2259 // If the type wasn't dependent on fission addresses, finish adding the type
2260 // and all its dependent types.
2261 for (auto &TU : TypeUnitsToAdd)
2262 InfoHolder.addUnit(std::move(TU.first));
2264 CU.addDIETypeSignature(RefDie, NewTU);
2267 // Accelerator table mutators - add each name along with its companion
2268 // DIE to the proper table while ensuring that the name that we're going
2269 // to reference is in the string table. We do this since the names we
2270 // add may not only be identical to the names in the DIE.
2271 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2272 if (!useDwarfAccelTables())
2274 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2278 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2279 if (!useDwarfAccelTables())
2281 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2285 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2286 if (!useDwarfAccelTables())
2288 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2292 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2293 if (!useDwarfAccelTables())
2295 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),