1 //===-- llvm/CodeGen/DwarfDebug.cpp - Dwarf Debug Framework ---------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains support for writing dwarf debug info into asm files.
12 //===----------------------------------------------------------------------===//
14 #include "DwarfDebug.h"
15 #include "ByteStreamer.h"
17 #include "DebugLocEntry.h"
18 #include "DwarfCompileUnit.h"
19 #include "DwarfExpression.h"
20 #include "DwarfUnit.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/CodeGen/DIE.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineModuleInfo.h"
28 #include "llvm/IR/Constants.h"
29 #include "llvm/IR/DIBuilder.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/DebugInfo.h"
32 #include "llvm/IR/Instructions.h"
33 #include "llvm/IR/Module.h"
34 #include "llvm/IR/ValueHandle.h"
35 #include "llvm/MC/MCAsmInfo.h"
36 #include "llvm/MC/MCDwarf.h"
37 #include "llvm/MC/MCSection.h"
38 #include "llvm/MC/MCStreamer.h"
39 #include "llvm/MC/MCSymbol.h"
40 #include "llvm/Support/CommandLine.h"
41 #include "llvm/Support/Debug.h"
42 #include "llvm/Support/Dwarf.h"
43 #include "llvm/Support/Endian.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/FormattedStream.h"
46 #include "llvm/Support/LEB128.h"
47 #include "llvm/Support/MD5.h"
48 #include "llvm/Support/Path.h"
49 #include "llvm/Support/Timer.h"
50 #include "llvm/Support/raw_ostream.h"
51 #include "llvm/Target/TargetFrameLowering.h"
52 #include "llvm/Target/TargetLoweringObjectFile.h"
53 #include "llvm/Target/TargetMachine.h"
54 #include "llvm/Target/TargetOptions.h"
55 #include "llvm/Target/TargetRegisterInfo.h"
56 #include "llvm/Target/TargetSubtargetInfo.h"
59 #define DEBUG_TYPE "dwarfdebug"
62 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
63 cl::desc("Disable debug info printing"));
65 static cl::opt<bool> UnknownLocations(
66 "use-unknown-locations", cl::Hidden,
67 cl::desc("Make an absence of debug location information explicit."),
71 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
72 cl::desc("Generate GNU-style pubnames and pubtypes"),
75 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
77 cl::desc("Generate dwarf aranges"),
80 static cl::opt<DebuggerKind>
81 DebuggerTuningOpt("debugger-tune",
82 cl::desc("Tune debug info for a particular debugger"),
83 cl::init(DebuggerKind::Default),
85 clEnumValN(DebuggerKind::GDB, "gdb", "gdb"),
86 clEnumValN(DebuggerKind::LLDB, "lldb", "lldb"),
87 clEnumValN(DebuggerKind::SCE, "sce",
88 "SCE targets (e.g. PS4)"),
92 enum DefaultOnOff { Default, Enable, Disable };
95 static cl::opt<DefaultOnOff>
96 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
97 cl::desc("Output prototype dwarf accelerator tables."),
98 cl::values(clEnumVal(Default, "Default for platform"),
99 clEnumVal(Enable, "Enabled"),
100 clEnumVal(Disable, "Disabled"), clEnumValEnd),
103 static cl::opt<DefaultOnOff>
104 SplitDwarf("split-dwarf", cl::Hidden,
105 cl::desc("Output DWARF5 split debug info."),
106 cl::values(clEnumVal(Default, "Default for platform"),
107 clEnumVal(Enable, "Enabled"),
108 clEnumVal(Disable, "Disabled"), clEnumValEnd),
111 static cl::opt<DefaultOnOff>
112 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
113 cl::desc("Generate DWARF pubnames and pubtypes sections"),
114 cl::values(clEnumVal(Default, "Default for platform"),
115 clEnumVal(Enable, "Enabled"),
116 clEnumVal(Disable, "Disabled"), clEnumValEnd),
119 static const char *const DWARFGroupName = "DWARF Emission";
120 static const char *const DbgTimerName = "DWARF Debug Writer";
122 void DebugLocDwarfExpression::EmitOp(uint8_t Op, const char *Comment) {
124 Op, Comment ? Twine(Comment) + " " + dwarf::OperationEncodingString(Op)
125 : dwarf::OperationEncodingString(Op));
128 void DebugLocDwarfExpression::EmitSigned(int64_t Value) {
129 BS.EmitSLEB128(Value, Twine(Value));
132 void DebugLocDwarfExpression::EmitUnsigned(uint64_t Value) {
133 BS.EmitULEB128(Value, Twine(Value));
136 bool DebugLocDwarfExpression::isFrameRegister(unsigned MachineReg) {
137 // This information is not available while emitting .debug_loc entries.
141 //===----------------------------------------------------------------------===//
143 /// resolve - Look in the DwarfDebug map for the MDNode that
144 /// corresponds to the reference.
145 template <typename T> T *DbgVariable::resolve(TypedDINodeRef<T> Ref) const {
146 return DD->resolve(Ref);
149 bool DbgVariable::isBlockByrefVariable() const {
150 assert(Var && "Invalid complex DbgVariable!");
151 return Var->getType()
152 .resolve(DD->getTypeIdentifierMap())
153 ->isBlockByrefStruct();
156 const DIType *DbgVariable::getType() const {
157 DIType *Ty = Var->getType().resolve(DD->getTypeIdentifierMap());
158 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
159 // addresses instead.
160 if (Ty->isBlockByrefStruct()) {
161 /* Byref variables, in Blocks, are declared by the programmer as
162 "SomeType VarName;", but the compiler creates a
163 __Block_byref_x_VarName struct, and gives the variable VarName
164 either the struct, or a pointer to the struct, as its type. This
165 is necessary for various behind-the-scenes things the compiler
166 needs to do with by-reference variables in blocks.
168 However, as far as the original *programmer* is concerned, the
169 variable should still have type 'SomeType', as originally declared.
171 The following function dives into the __Block_byref_x_VarName
172 struct to find the original type of the variable. This will be
173 passed back to the code generating the type for the Debug
174 Information Entry for the variable 'VarName'. 'VarName' will then
175 have the original type 'SomeType' in its debug information.
177 The original type 'SomeType' will be the type of the field named
178 'VarName' inside the __Block_byref_x_VarName struct.
180 NOTE: In order for this to not completely fail on the debugger
181 side, the Debug Information Entry for the variable VarName needs to
182 have a DW_AT_location that tells the debugger how to unwind through
183 the pointers and __Block_byref_x_VarName struct to find the actual
184 value of the variable. The function addBlockByrefType does this. */
185 DIType *subType = Ty;
186 uint16_t tag = Ty->getTag();
188 if (tag == dwarf::DW_TAG_pointer_type)
189 subType = resolve(cast<DIDerivedType>(Ty)->getBaseType());
191 auto Elements = cast<DICompositeType>(subType)->getElements();
192 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
193 auto *DT = cast<DIDerivedType>(Elements[i]);
194 if (getName() == DT->getName())
195 return resolve(DT->getBaseType());
201 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
202 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
203 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
204 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
206 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
207 : Asm(A), MMI(Asm->MMI), DebugLocs(A->OutStreamer->isVerboseAsm()),
208 PrevLabel(nullptr), InfoHolder(A, "info_string", DIEValueAllocator),
209 UsedNonDefaultText(false),
210 SkeletonHolder(A, "skel_string", DIEValueAllocator),
211 IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
212 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
213 dwarf::DW_FORM_data4)),
214 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
215 dwarf::DW_FORM_data4)),
216 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
217 dwarf::DW_FORM_data4)),
218 AccelTypes(TypeAtoms), DebuggerTuning(DebuggerKind::Default) {
222 Triple TT(Asm->getTargetTriple());
224 // Make sure we know our "debugger tuning." The command-line option takes
225 // precedence; fall back to triple-based defaults.
226 if (DebuggerTuningOpt != DebuggerKind::Default)
227 DebuggerTuning = DebuggerTuningOpt;
228 else if (IsDarwin || TT.isOSFreeBSD())
229 DebuggerTuning = DebuggerKind::LLDB;
230 else if (TT.isPS4CPU())
231 DebuggerTuning = DebuggerKind::SCE;
233 DebuggerTuning = DebuggerKind::GDB;
235 // Turn on accelerator tables for LLDB by default.
236 if (DwarfAccelTables == Default)
237 HasDwarfAccelTables = tuneForLLDB();
239 HasDwarfAccelTables = DwarfAccelTables == Enable;
241 // Handle split DWARF. Off by default for now.
242 if (SplitDwarf == Default)
243 HasSplitDwarf = false;
245 HasSplitDwarf = SplitDwarf == Enable;
247 // Pubnames/pubtypes on by default for GDB.
248 if (DwarfPubSections == Default)
249 HasDwarfPubSections = tuneForGDB();
251 HasDwarfPubSections = DwarfPubSections == Enable;
253 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
254 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
255 : MMI->getModule()->getDwarfVersion();
256 // Use dwarf 4 by default if nothing is requested.
257 DwarfVersion = DwarfVersion ? DwarfVersion : dwarf::DWARF_VERSION;
259 // Work around a GDB bug. GDB doesn't support the standard opcode;
260 // SCE doesn't support GNU's; LLDB prefers the standard opcode, which
261 // is defined as of DWARF 3.
262 // See GDB bug 11616 - DW_OP_form_tls_address is unimplemented
263 // https://sourceware.org/bugzilla/show_bug.cgi?id=11616
264 UseGNUTLSOpcode = tuneForGDB() || DwarfVersion < 3;
266 Asm->OutStreamer->getContext().setDwarfVersion(DwarfVersion);
269 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
274 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
275 DwarfDebug::~DwarfDebug() { }
277 static bool isObjCClass(StringRef Name) {
278 return Name.startswith("+") || Name.startswith("-");
281 static bool hasObjCCategory(StringRef Name) {
282 if (!isObjCClass(Name))
285 return Name.find(") ") != StringRef::npos;
288 static void getObjCClassCategory(StringRef In, StringRef &Class,
289 StringRef &Category) {
290 if (!hasObjCCategory(In)) {
291 Class = In.slice(In.find('[') + 1, In.find(' '));
296 Class = In.slice(In.find('[') + 1, In.find('('));
297 Category = In.slice(In.find('[') + 1, In.find(' '));
301 static StringRef getObjCMethodName(StringRef In) {
302 return In.slice(In.find(' ') + 1, In.find(']'));
305 // Add the various names to the Dwarf accelerator table names.
306 // TODO: Determine whether or not we should add names for programs
307 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
308 // is only slightly different than the lookup of non-standard ObjC names.
309 void DwarfDebug::addSubprogramNames(const DISubprogram *SP, DIE &Die) {
310 if (!SP->isDefinition())
312 addAccelName(SP->getName(), Die);
314 // If the linkage name is different than the name, go ahead and output
315 // that as well into the name table.
316 if (SP->getLinkageName() != "" && SP->getName() != SP->getLinkageName())
317 addAccelName(SP->getLinkageName(), Die);
319 // If this is an Objective-C selector name add it to the ObjC accelerator
321 if (isObjCClass(SP->getName())) {
322 StringRef Class, Category;
323 getObjCClassCategory(SP->getName(), Class, Category);
324 addAccelObjC(Class, Die);
326 addAccelObjC(Category, Die);
327 // Also add the base method name to the name table.
328 addAccelName(getObjCMethodName(SP->getName()), Die);
332 /// isSubprogramContext - Return true if Context is either a subprogram
333 /// or another context nested inside a subprogram.
334 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
337 if (isa<DISubprogram>(Context))
339 if (auto *T = dyn_cast<DIType>(Context))
340 return isSubprogramContext(resolve(T->getScope()));
344 /// Check whether we should create a DIE for the given Scope, return true
345 /// if we don't create a DIE (the corresponding DIE is null).
346 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
347 if (Scope->isAbstractScope())
350 // We don't create a DIE if there is no Range.
351 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
355 if (Ranges.size() > 1)
358 // We don't create a DIE if we have a single Range and the end label
360 return !getLabelAfterInsn(Ranges.front().second);
363 template <typename Func> void forBothCUs(DwarfCompileUnit &CU, Func F) {
365 if (auto *SkelCU = CU.getSkeleton())
369 void DwarfDebug::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
370 assert(Scope && Scope->getScopeNode());
371 assert(Scope->isAbstractScope());
372 assert(!Scope->getInlinedAt());
374 const MDNode *SP = Scope->getScopeNode();
376 ProcessedSPNodes.insert(SP);
378 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
379 // was inlined from another compile unit.
380 auto &CU = SPMap[SP];
381 forBothCUs(*CU, [&](DwarfCompileUnit &CU) {
382 CU.constructAbstractSubprogramScopeDIE(Scope);
386 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
387 if (!GenerateGnuPubSections)
390 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
393 // Create new DwarfCompileUnit for the given metadata node with tag
394 // DW_TAG_compile_unit.
396 DwarfDebug::constructDwarfCompileUnit(const DICompileUnit *DIUnit) {
397 StringRef FN = DIUnit->getFilename();
398 CompilationDir = DIUnit->getDirectory();
400 auto OwnedUnit = make_unique<DwarfCompileUnit>(
401 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
402 DwarfCompileUnit &NewCU = *OwnedUnit;
403 DIE &Die = NewCU.getUnitDie();
404 InfoHolder.addUnit(std::move(OwnedUnit));
406 NewCU.setSkeleton(constructSkeletonCU(NewCU));
408 // LTO with assembly output shares a single line table amongst multiple CUs.
409 // To avoid the compilation directory being ambiguous, let the line table
410 // explicitly describe the directory of all files, never relying on the
411 // compilation directory.
412 if (!Asm->OutStreamer->hasRawTextSupport() || SingleCU)
413 Asm->OutStreamer->getContext().setMCLineTableCompilationDir(
414 NewCU.getUniqueID(), CompilationDir);
416 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit->getProducer());
417 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
418 DIUnit->getSourceLanguage());
419 NewCU.addString(Die, dwarf::DW_AT_name, FN);
421 if (!useSplitDwarf()) {
422 NewCU.initStmtList();
424 // If we're using split dwarf the compilation dir is going to be in the
425 // skeleton CU and so we don't need to duplicate it here.
426 if (!CompilationDir.empty())
427 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
429 addGnuPubAttributes(NewCU, Die);
432 if (DIUnit->isOptimized())
433 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
435 StringRef Flags = DIUnit->getFlags();
437 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
439 if (unsigned RVer = DIUnit->getRuntimeVersion())
440 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
441 dwarf::DW_FORM_data1, RVer);
444 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection());
446 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
448 CUMap.insert(std::make_pair(DIUnit, &NewCU));
449 CUDieMap.insert(std::make_pair(&Die, &NewCU));
453 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
454 const DIImportedEntity *N) {
455 if (DIE *D = TheCU.getOrCreateContextDIE(N->getScope()))
456 D->addChild(TheCU.constructImportedEntityDIE(N));
459 // Emit all Dwarf sections that should come prior to the content. Create
460 // global DIEs and emit initial debug info sections. This is invoked by
461 // the target AsmPrinter.
462 void DwarfDebug::beginModule() {
463 if (DisableDebugInfoPrinting)
466 const Module *M = MMI->getModule();
468 FunctionDIs = makeSubprogramMap(*M);
470 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
473 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
475 SingleCU = CU_Nodes->getNumOperands() == 1;
477 for (MDNode *N : CU_Nodes->operands()) {
478 auto *CUNode = cast<DICompileUnit>(N);
479 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
480 for (auto *IE : CUNode->getImportedEntities())
481 ScopesWithImportedEntities.push_back(std::make_pair(IE->getScope(), IE));
482 // Stable sort to preserve the order of appearance of imported entities.
483 // This is to avoid out-of-order processing of interdependent declarations
484 // within the same scope, e.g. { namespace A = base; namespace B = A; }
485 std::stable_sort(ScopesWithImportedEntities.begin(),
486 ScopesWithImportedEntities.end(), less_first());
487 for (auto *GV : CUNode->getGlobalVariables())
488 CU.getOrCreateGlobalVariableDIE(GV);
489 for (auto *SP : CUNode->getSubprograms())
490 SPMap.insert(std::make_pair(SP, &CU));
491 for (auto *Ty : CUNode->getEnumTypes()) {
492 // The enum types array by design contains pointers to
493 // MDNodes rather than DIRefs. Unique them here.
494 CU.getOrCreateTypeDIE(cast<DIType>(resolve(Ty->getRef())));
496 for (auto *Ty : CUNode->getRetainedTypes()) {
497 // The retained types array by design contains pointers to
498 // MDNodes rather than DIRefs. Unique them here.
499 DIType *RT = cast<DIType>(resolve(Ty->getRef()));
500 if (!RT->isExternalTypeRef())
501 // There is no point in force-emitting a forward declaration.
502 CU.getOrCreateTypeDIE(RT);
504 // Emit imported_modules last so that the relevant context is already
506 for (auto *IE : CUNode->getImportedEntities())
507 constructAndAddImportedEntityDIE(CU, IE);
510 // Tell MMI that we have debug info.
511 MMI->setDebugInfoAvailability(true);
514 void DwarfDebug::finishVariableDefinitions() {
515 for (const auto &Var : ConcreteVariables) {
516 DIE *VariableDie = Var->getDIE();
518 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
519 // in the ConcreteVariables list, rather than looking it up again here.
520 // DIE::getUnit isn't simple - it walks parent pointers, etc.
521 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
523 DbgVariable *AbsVar = getExistingAbstractVariable(
524 InlinedVariable(Var->getVariable(), Var->getInlinedAt()));
525 if (AbsVar && AbsVar->getDIE()) {
526 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
529 Unit->applyVariableAttributes(*Var, *VariableDie);
533 void DwarfDebug::finishSubprogramDefinitions() {
534 for (const auto &P : SPMap)
535 forBothCUs(*P.second, [&](DwarfCompileUnit &CU) {
536 CU.finishSubprogramDefinition(cast<DISubprogram>(P.first));
541 // Collect info for variables that were optimized out.
542 void DwarfDebug::collectDeadVariables() {
543 const Module *M = MMI->getModule();
545 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
546 for (MDNode *N : CU_Nodes->operands()) {
547 auto *TheCU = cast<DICompileUnit>(N);
548 // Construct subprogram DIE and add variables DIEs.
549 DwarfCompileUnit *SPCU =
550 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
551 assert(SPCU && "Unable to find Compile Unit!");
552 for (auto *SP : TheCU->getSubprograms()) {
553 if (ProcessedSPNodes.count(SP) != 0)
555 SPCU->collectDeadVariables(SP);
561 void DwarfDebug::finalizeModuleInfo() {
562 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
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 &P : CUMap) {
574 auto &TheCU = *P.second;
575 // Emit DW_AT_containing_type attribute to connect types with their
576 // vtable holding type.
577 TheCU.constructContainingTypeDIEs();
579 // Add CU specific attributes if we need to add any.
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 auto *SkCU = TheCU.getSkeleton();
583 if (useSplitDwarf()) {
584 // Emit a unique identifier for this CU.
585 uint64_t ID = DIEHash(Asm).computeCUSignature(TheCU.getUnitDie());
586 TheCU.addUInt(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
587 dwarf::DW_FORM_data8, ID);
588 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
589 dwarf::DW_FORM_data8, ID);
591 // We don't keep track of which addresses are used in which CU so this
592 // is a bit pessimistic under LTO.
593 if (!AddrPool.isEmpty()) {
594 const MCSymbol *Sym = TLOF.getDwarfAddrSection()->getBeginSymbol();
595 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_addr_base,
598 if (!SkCU->getRangeLists().empty()) {
599 const MCSymbol *Sym = TLOF.getDwarfRangesSection()->getBeginSymbol();
600 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
605 // If we have code split among multiple sections or non-contiguous
606 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
607 // remain in the .o file, otherwise add a DW_AT_low_pc.
608 // FIXME: We should use ranges allow reordering of code ala
609 // .subsections_via_symbols in mach-o. This would mean turning on
610 // ranges for all subprogram DIEs for mach-o.
611 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
612 if (unsigned NumRanges = TheCU.getRanges().size()) {
614 // A DW_AT_low_pc attribute may also be specified in combination with
615 // DW_AT_ranges to specify the default base address for use in
616 // location lists (see Section 2.6.2) and range lists (see Section
618 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
620 U.setBaseAddress(TheCU.getRanges().front().getStart());
621 U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
625 // Compute DIE offsets and sizes.
626 InfoHolder.computeSizeAndOffsets();
628 SkeletonHolder.computeSizeAndOffsets();
631 // Emit all Dwarf sections that should come after the content.
632 void DwarfDebug::endModule() {
633 assert(CurFn == nullptr);
634 assert(CurMI == nullptr);
636 // If we aren't actually generating debug info (check beginModule -
637 // conditionalized on !DisableDebugInfoPrinting and the presence of the
638 // llvm.dbg.cu metadata node)
639 if (!MMI->hasDebugInfo())
642 // Finalize the debug info for the module.
643 finalizeModuleInfo();
650 // Emit info into a debug loc section.
653 // Corresponding abbreviations into a abbrev section.
656 // Emit all the DIEs into a debug info section.
659 // Emit info into a debug aranges section.
660 if (GenerateARangeSection)
663 // Emit info into a debug ranges section.
666 if (useSplitDwarf()) {
669 emitDebugAbbrevDWO();
671 // Emit DWO addresses.
672 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
675 // Emit info into the dwarf accelerator table sections.
676 if (useDwarfAccelTables()) {
679 emitAccelNamespaces();
683 // Emit the pubnames and pubtypes sections if requested.
684 if (HasDwarfPubSections) {
685 emitDebugPubNames(GenerateGnuPubSections);
686 emitDebugPubTypes(GenerateGnuPubSections);
691 AbstractVariables.clear();
694 // Find abstract variable, if any, associated with Var.
696 DwarfDebug::getExistingAbstractVariable(InlinedVariable IV,
697 const DILocalVariable *&Cleansed) {
698 // More then one inlined variable corresponds to one abstract variable.
700 auto I = AbstractVariables.find(Cleansed);
701 if (I != AbstractVariables.end())
702 return I->second.get();
706 DbgVariable *DwarfDebug::getExistingAbstractVariable(InlinedVariable IV) {
707 const DILocalVariable *Cleansed;
708 return getExistingAbstractVariable(IV, Cleansed);
711 void DwarfDebug::createAbstractVariable(const DILocalVariable *Var,
712 LexicalScope *Scope) {
713 auto AbsDbgVariable = make_unique<DbgVariable>(Var, /* IA */ nullptr, this);
714 InfoHolder.addScopeVariable(Scope, AbsDbgVariable.get());
715 AbstractVariables[Var] = std::move(AbsDbgVariable);
718 void DwarfDebug::ensureAbstractVariableIsCreated(InlinedVariable IV,
719 const MDNode *ScopeNode) {
720 const DILocalVariable *Cleansed = nullptr;
721 if (getExistingAbstractVariable(IV, Cleansed))
724 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(
725 cast<DILocalScope>(ScopeNode)));
728 void DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(
729 InlinedVariable IV, const MDNode *ScopeNode) {
730 const DILocalVariable *Cleansed = nullptr;
731 if (getExistingAbstractVariable(IV, Cleansed))
734 if (LexicalScope *Scope =
735 LScopes.findAbstractScope(cast_or_null<DILocalScope>(ScopeNode)))
736 createAbstractVariable(Cleansed, Scope);
739 // Collect variable information from side table maintained by MMI.
740 void DwarfDebug::collectVariableInfoFromMMITable(
741 DenseSet<InlinedVariable> &Processed) {
742 for (const auto &VI : MMI->getVariableDbgInfo()) {
745 assert(VI.Var->isValidLocationForIntrinsic(VI.Loc) &&
746 "Expected inlined-at fields to agree");
748 InlinedVariable Var(VI.Var, VI.Loc->getInlinedAt());
749 Processed.insert(Var);
750 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
752 // If variable scope is not found then skip this variable.
756 ensureAbstractVariableIsCreatedIfScoped(Var, Scope->getScopeNode());
757 auto RegVar = make_unique<DbgVariable>(Var.first, Var.second, this);
758 RegVar->initializeMMI(VI.Expr, VI.Slot);
759 if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
760 ConcreteVariables.push_back(std::move(RegVar));
764 // Get .debug_loc entry for the instruction range starting at MI.
765 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
766 const DIExpression *Expr = MI->getDebugExpression();
768 assert(MI->getNumOperands() == 4);
769 if (MI->getOperand(0).isReg()) {
770 MachineLocation MLoc;
771 // If the second operand is an immediate, this is a
772 // register-indirect address.
773 if (!MI->getOperand(1).isImm())
774 MLoc.set(MI->getOperand(0).getReg());
776 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
777 return DebugLocEntry::Value(Expr, MLoc);
779 if (MI->getOperand(0).isImm())
780 return DebugLocEntry::Value(Expr, MI->getOperand(0).getImm());
781 if (MI->getOperand(0).isFPImm())
782 return DebugLocEntry::Value(Expr, MI->getOperand(0).getFPImm());
783 if (MI->getOperand(0).isCImm())
784 return DebugLocEntry::Value(Expr, MI->getOperand(0).getCImm());
786 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
789 /// Determine whether two variable pieces overlap.
790 static bool piecesOverlap(const DIExpression *P1, const DIExpression *P2) {
791 if (!P1->isBitPiece() || !P2->isBitPiece())
793 unsigned l1 = P1->getBitPieceOffset();
794 unsigned l2 = P2->getBitPieceOffset();
795 unsigned r1 = l1 + P1->getBitPieceSize();
796 unsigned r2 = l2 + P2->getBitPieceSize();
797 // True where [l1,r1[ and [r1,r2[ overlap.
798 return (l1 < r2) && (l2 < r1);
801 /// Build the location list for all DBG_VALUEs in the function that
802 /// describe the same variable. If the ranges of several independent
803 /// pieces of the same variable overlap partially, split them up and
804 /// combine the ranges. The resulting DebugLocEntries are will have
805 /// strict monotonically increasing begin addresses and will never
810 // Ranges History [var, loc, piece ofs size]
811 // 0 | [x, (reg0, piece 0, 32)]
812 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
814 // 3 | [clobber reg0]
815 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of
820 // [0-1] [x, (reg0, piece 0, 32)]
821 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
822 // [3-4] [x, (reg1, piece 32, 32)]
823 // [4- ] [x, (mem, piece 0, 64)]
825 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
826 const DbgValueHistoryMap::InstrRanges &Ranges) {
827 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
829 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
830 const MachineInstr *Begin = I->first;
831 const MachineInstr *End = I->second;
832 assert(Begin->isDebugValue() && "Invalid History entry");
834 // Check if a variable is inaccessible in this range.
835 if (Begin->getNumOperands() > 1 &&
836 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
841 // If this piece overlaps with any open ranges, truncate them.
842 const DIExpression *DIExpr = Begin->getDebugExpression();
843 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
844 [&](DebugLocEntry::Value R) {
845 return piecesOverlap(DIExpr, R.getExpression());
847 OpenRanges.erase(Last, OpenRanges.end());
849 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
850 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
852 const MCSymbol *EndLabel;
854 EndLabel = getLabelAfterInsn(End);
855 else if (std::next(I) == Ranges.end())
856 EndLabel = Asm->getFunctionEnd();
858 EndLabel = getLabelBeforeInsn(std::next(I)->first);
859 assert(EndLabel && "Forgot label after instruction ending a range!");
861 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
863 auto Value = getDebugLocValue(Begin);
864 DebugLocEntry Loc(StartLabel, EndLabel, Value);
865 bool couldMerge = false;
867 // If this is a piece, it may belong to the current DebugLocEntry.
868 if (DIExpr->isBitPiece()) {
869 // Add this value to the list of open ranges.
870 OpenRanges.push_back(Value);
872 // Attempt to add the piece to the last entry.
873 if (!DebugLoc.empty())
874 if (DebugLoc.back().MergeValues(Loc))
879 // Need to add a new DebugLocEntry. Add all values from still
880 // valid non-overlapping pieces.
881 if (OpenRanges.size())
882 Loc.addValues(OpenRanges);
884 DebugLoc.push_back(std::move(Loc));
887 // Attempt to coalesce the ranges of two otherwise identical
889 auto CurEntry = DebugLoc.rbegin();
891 dbgs() << CurEntry->getValues().size() << " Values:\n";
892 for (auto &Value : CurEntry->getValues())
893 Value.getExpression()->dump();
897 auto PrevEntry = std::next(CurEntry);
898 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
903 DbgVariable *DwarfDebug::createConcreteVariable(LexicalScope &Scope,
904 InlinedVariable IV) {
905 ensureAbstractVariableIsCreatedIfScoped(IV, Scope.getScopeNode());
906 ConcreteVariables.push_back(
907 make_unique<DbgVariable>(IV.first, IV.second, this));
908 InfoHolder.addScopeVariable(&Scope, ConcreteVariables.back().get());
909 return ConcreteVariables.back().get();
912 // Find variables for each lexical scope.
913 void DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU,
914 const DISubprogram *SP,
915 DenseSet<InlinedVariable> &Processed) {
916 // Grab the variable info that was squirreled away in the MMI side-table.
917 collectVariableInfoFromMMITable(Processed);
919 for (const auto &I : DbgValues) {
920 InlinedVariable IV = I.first;
921 if (Processed.count(IV))
924 // Instruction ranges, specifying where IV is accessible.
925 const auto &Ranges = I.second;
929 LexicalScope *Scope = nullptr;
930 if (const DILocation *IA = IV.second)
931 Scope = LScopes.findInlinedScope(IV.first->getScope(), IA);
933 Scope = LScopes.findLexicalScope(IV.first->getScope());
934 // If variable scope is not found then skip this variable.
938 Processed.insert(IV);
939 DbgVariable *RegVar = createConcreteVariable(*Scope, IV);
941 const MachineInstr *MInsn = Ranges.front().first;
942 assert(MInsn->isDebugValue() && "History must begin with debug value");
944 // Check if the first DBG_VALUE is valid for the rest of the function.
945 if (Ranges.size() == 1 && Ranges.front().second == nullptr) {
946 RegVar->initializeDbgValue(MInsn);
950 // Handle multiple DBG_VALUE instructions describing one variable.
951 DebugLocStream::ListBuilder List(DebugLocs, TheCU, *Asm, *RegVar, *MInsn);
953 // Build the location list for this variable.
954 SmallVector<DebugLocEntry, 8> Entries;
955 buildLocationList(Entries, Ranges);
957 // If the variable has an DIBasicType, extract it. Basic types cannot have
958 // unique identifiers, so don't bother resolving the type with the
960 const DIBasicType *BT = dyn_cast<DIBasicType>(
961 static_cast<const Metadata *>(IV.first->getType()));
963 // Finalize the entry by lowering it into a DWARF bytestream.
964 for (auto &Entry : Entries)
965 Entry.finalize(*Asm, List, BT);
968 // Collect info for variables that were optimized out.
969 for (const DILocalVariable *DV : SP->getVariables()) {
970 if (Processed.insert(InlinedVariable(DV, nullptr)).second)
971 if (LexicalScope *Scope = LScopes.findLexicalScope(DV->getScope()))
972 createConcreteVariable(*Scope, InlinedVariable(DV, nullptr));
976 // Return Label preceding the instruction.
977 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
978 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
979 assert(Label && "Didn't insert label before instruction");
983 // Return Label immediately following the instruction.
984 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
985 return LabelsAfterInsn.lookup(MI);
988 // Process beginning of an instruction.
989 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
990 assert(CurMI == nullptr);
992 // Check if source location changes, but ignore DBG_VALUE locations.
993 if (!MI->isDebugValue()) {
994 DebugLoc DL = MI->getDebugLoc();
995 if (DL != PrevInstLoc) {
999 if (DL == PrologEndLoc) {
1000 Flags |= DWARF2_FLAG_PROLOGUE_END;
1001 PrologEndLoc = DebugLoc();
1002 Flags |= DWARF2_FLAG_IS_STMT;
1005 Asm->OutStreamer->getContext().getCurrentDwarfLoc().getLine())
1006 Flags |= DWARF2_FLAG_IS_STMT;
1008 const MDNode *Scope = DL.getScope();
1009 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1010 } else if (UnknownLocations) {
1012 recordSourceLine(0, 0, nullptr, 0);
1017 // Insert labels where requested.
1018 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1019 LabelsBeforeInsn.find(MI);
1022 if (I == LabelsBeforeInsn.end())
1025 // Label already assigned.
1030 PrevLabel = MMI->getContext().createTempSymbol();
1031 Asm->OutStreamer->EmitLabel(PrevLabel);
1033 I->second = PrevLabel;
1036 // Process end of an instruction.
1037 void DwarfDebug::endInstruction() {
1038 assert(CurMI != nullptr);
1039 // Don't create a new label after DBG_VALUE instructions.
1040 // They don't generate code.
1041 if (!CurMI->isDebugValue())
1042 PrevLabel = nullptr;
1044 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1045 LabelsAfterInsn.find(CurMI);
1049 if (I == LabelsAfterInsn.end())
1052 // Label already assigned.
1056 // We need a label after this instruction.
1058 PrevLabel = MMI->getContext().createTempSymbol();
1059 Asm->OutStreamer->EmitLabel(PrevLabel);
1061 I->second = PrevLabel;
1064 // Each LexicalScope has first instruction and last instruction to mark
1065 // beginning and end of a scope respectively. Create an inverse map that list
1066 // scopes starts (and ends) with an instruction. One instruction may start (or
1067 // end) multiple scopes. Ignore scopes that are not reachable.
1068 void DwarfDebug::identifyScopeMarkers() {
1069 SmallVector<LexicalScope *, 4> WorkList;
1070 WorkList.push_back(LScopes.getCurrentFunctionScope());
1071 while (!WorkList.empty()) {
1072 LexicalScope *S = WorkList.pop_back_val();
1074 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1075 if (!Children.empty())
1076 WorkList.append(Children.begin(), Children.end());
1078 if (S->isAbstractScope())
1081 for (const InsnRange &R : S->getRanges()) {
1082 assert(R.first && "InsnRange does not have first instruction!");
1083 assert(R.second && "InsnRange does not have second instruction!");
1084 requestLabelBeforeInsn(R.first);
1085 requestLabelAfterInsn(R.second);
1090 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1091 // First known non-DBG_VALUE and non-frame setup location marks
1092 // the beginning of the function body.
1093 for (const auto &MBB : *MF)
1094 for (const auto &MI : MBB)
1095 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1097 // Did the target forget to set the FrameSetup flag for CFI insns?
1098 assert(!MI.isCFIInstruction() &&
1099 "First non-frame-setup instruction is a CFI instruction.");
1100 return MI.getDebugLoc();
1105 // Gather pre-function debug information. Assumes being called immediately
1106 // after the function entry point has been emitted.
1107 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1110 // If there's no debug info for the function we're not going to do anything.
1111 if (!MMI->hasDebugInfo())
1114 auto DI = FunctionDIs.find(MF->getFunction());
1115 if (DI == FunctionDIs.end())
1118 // Grab the lexical scopes for the function, if we don't have any of those
1119 // then we're not going to be able to do anything.
1120 LScopes.initialize(*MF);
1121 if (LScopes.empty())
1124 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1126 // Make sure that each lexical scope will have a begin/end label.
1127 identifyScopeMarkers();
1129 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1130 // belongs to so that we add to the correct per-cu line table in the
1132 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1133 // FnScope->getScopeNode() and DI->second should represent the same function,
1134 // though they may not be the same MDNode due to inline functions merged in
1135 // LTO where the debug info metadata still differs (either due to distinct
1136 // written differences - two versions of a linkonce_odr function
1137 // written/copied into two separate files, or some sub-optimal metadata that
1138 // isn't structurally identical (see: file path/name info from clang, which
1139 // includes the directory of the cpp file being built, even when the file name
1140 // is absolute (such as an <> lookup header)))
1141 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1142 assert(TheCU && "Unable to find compile unit!");
1143 if (Asm->OutStreamer->hasRawTextSupport())
1144 // Use a single line table if we are generating assembly.
1145 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
1147 Asm->OutStreamer->getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1149 // Calculate history for local variables.
1150 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1153 // Request labels for the full history.
1154 for (const auto &I : DbgValues) {
1155 const auto &Ranges = I.second;
1159 // The first mention of a function argument gets the CurrentFnBegin
1160 // label, so arguments are visible when breaking at function entry.
1161 const DILocalVariable *DIVar = Ranges.front().first->getDebugVariable();
1162 if (DIVar->isParameter() &&
1163 getDISubprogram(DIVar->getScope())->describes(MF->getFunction())) {
1164 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1165 if (Ranges.front().first->getDebugExpression()->isBitPiece()) {
1166 // Mark all non-overlapping initial pieces.
1167 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1168 const DIExpression *Piece = I->first->getDebugExpression();
1169 if (std::all_of(Ranges.begin(), I,
1170 [&](DbgValueHistoryMap::InstrRange Pred) {
1171 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1173 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1180 for (const auto &Range : Ranges) {
1181 requestLabelBeforeInsn(Range.first);
1183 requestLabelAfterInsn(Range.second);
1187 PrevInstLoc = DebugLoc();
1188 PrevLabel = Asm->getFunctionBegin();
1190 // Record beginning of function.
1191 PrologEndLoc = findPrologueEndLoc(MF);
1192 if (DILocation *L = PrologEndLoc) {
1193 // We'd like to list the prologue as "not statements" but GDB behaves
1194 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1195 auto *SP = L->getInlinedAtScope()->getSubprogram();
1196 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1200 // Gather and emit post-function debug information.
1201 void DwarfDebug::endFunction(const MachineFunction *MF) {
1202 assert(CurFn == MF &&
1203 "endFunction should be called with the same function as beginFunction");
1205 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1206 !FunctionDIs.count(MF->getFunction())) {
1207 // If we don't have a lexical scope for this function then there will
1208 // be a hole in the range information. Keep note of this by setting the
1209 // previously used section to nullptr.
1215 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1216 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
1218 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1219 auto *SP = cast<DISubprogram>(FnScope->getScopeNode());
1220 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1222 DenseSet<InlinedVariable> ProcessedVars;
1223 collectVariableInfo(TheCU, SP, ProcessedVars);
1225 // Add the range of this function to the list of ranges for the CU.
1226 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1228 // Under -gmlt, skip building the subprogram if there are no inlined
1229 // subroutines inside it.
1230 if (TheCU.getCUNode()->getEmissionKind() == DIBuilder::LineTablesOnly &&
1231 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1232 assert(InfoHolder.getScopeVariables().empty());
1233 assert(DbgValues.empty());
1234 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1235 // by a -gmlt CU. Add a test and remove this assertion.
1236 assert(AbstractVariables.empty());
1237 LabelsBeforeInsn.clear();
1238 LabelsAfterInsn.clear();
1239 PrevLabel = nullptr;
1245 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1247 // Construct abstract scopes.
1248 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1249 auto *SP = cast<DISubprogram>(AScope->getScopeNode());
1250 // Collect info for variables that were optimized out.
1251 for (const DILocalVariable *DV : SP->getVariables()) {
1252 if (!ProcessedVars.insert(InlinedVariable(DV, nullptr)).second)
1254 ensureAbstractVariableIsCreated(InlinedVariable(DV, nullptr),
1256 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1257 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1259 constructAbstractSubprogramScopeDIE(AScope);
1262 TheCU.constructSubprogramScopeDIE(FnScope);
1263 if (auto *SkelCU = TheCU.getSkeleton())
1264 if (!LScopes.getAbstractScopesList().empty())
1265 SkelCU->constructSubprogramScopeDIE(FnScope);
1268 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1269 // DbgVariables except those that are also in AbstractVariables (since they
1270 // can be used cross-function)
1271 InfoHolder.getScopeVariables().clear();
1273 LabelsBeforeInsn.clear();
1274 LabelsAfterInsn.clear();
1275 PrevLabel = nullptr;
1279 // Register a source line with debug info. Returns the unique label that was
1280 // emitted and which provides correspondence to the source line list.
1281 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1286 unsigned Discriminator = 0;
1287 if (auto *Scope = cast_or_null<DIScope>(S)) {
1288 Fn = Scope->getFilename();
1289 Dir = Scope->getDirectory();
1290 if (auto *LBF = dyn_cast<DILexicalBlockFile>(Scope))
1291 Discriminator = LBF->getDiscriminator();
1293 unsigned CUID = Asm->OutStreamer->getContext().getDwarfCompileUnitID();
1294 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1295 .getOrCreateSourceID(Fn, Dir);
1297 Asm->OutStreamer->EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1301 //===----------------------------------------------------------------------===//
1303 //===----------------------------------------------------------------------===//
1305 // Emit the debug info section.
1306 void DwarfDebug::emitDebugInfo() {
1307 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1308 Holder.emitUnits(/* UseOffsets */ false);
1311 // Emit the abbreviation section.
1312 void DwarfDebug::emitAbbreviations() {
1313 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1315 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1318 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, MCSection *Section,
1319 StringRef TableName) {
1320 Accel.FinalizeTable(Asm, TableName);
1321 Asm->OutStreamer->SwitchSection(Section);
1323 // Emit the full data.
1324 Accel.emit(Asm, Section->getBeginSymbol(), this);
1327 // Emit visible names into a hashed accelerator table section.
1328 void DwarfDebug::emitAccelNames() {
1329 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1333 // Emit objective C classes and categories into a hashed accelerator table
1335 void DwarfDebug::emitAccelObjC() {
1336 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1340 // Emit namespace dies into a hashed accelerator table.
1341 void DwarfDebug::emitAccelNamespaces() {
1342 emitAccel(AccelNamespace,
1343 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1347 // Emit type dies into a hashed accelerator table.
1348 void DwarfDebug::emitAccelTypes() {
1349 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1353 // Public name handling.
1354 // The format for the various pubnames:
1356 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1357 // for the DIE that is named.
1359 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1360 // into the CU and the index value is computed according to the type of value
1361 // for the DIE that is named.
1363 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1364 // it's the offset within the debug_info/debug_types dwo section, however, the
1365 // reference in the pubname header doesn't change.
1367 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1368 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1370 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1372 // We could have a specification DIE that has our most of our knowledge,
1373 // look for that now.
1374 if (DIEValue SpecVal = Die->findAttribute(dwarf::DW_AT_specification)) {
1375 DIE &SpecDIE = SpecVal.getDIEEntry().getEntry();
1376 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1377 Linkage = dwarf::GIEL_EXTERNAL;
1378 } else if (Die->findAttribute(dwarf::DW_AT_external))
1379 Linkage = dwarf::GIEL_EXTERNAL;
1381 switch (Die->getTag()) {
1382 case dwarf::DW_TAG_class_type:
1383 case dwarf::DW_TAG_structure_type:
1384 case dwarf::DW_TAG_union_type:
1385 case dwarf::DW_TAG_enumeration_type:
1386 return dwarf::PubIndexEntryDescriptor(
1387 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1388 ? dwarf::GIEL_STATIC
1389 : dwarf::GIEL_EXTERNAL);
1390 case dwarf::DW_TAG_typedef:
1391 case dwarf::DW_TAG_base_type:
1392 case dwarf::DW_TAG_subrange_type:
1393 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1394 case dwarf::DW_TAG_namespace:
1395 return dwarf::GIEK_TYPE;
1396 case dwarf::DW_TAG_subprogram:
1397 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1398 case dwarf::DW_TAG_variable:
1399 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1400 case dwarf::DW_TAG_enumerator:
1401 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1402 dwarf::GIEL_STATIC);
1404 return dwarf::GIEK_NONE;
1408 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1410 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1411 MCSection *PSec = GnuStyle
1412 ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1413 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1415 emitDebugPubSection(GnuStyle, PSec, "Names",
1416 &DwarfCompileUnit::getGlobalNames);
1419 void DwarfDebug::emitDebugPubSection(
1420 bool GnuStyle, MCSection *PSec, StringRef Name,
1421 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1422 for (const auto &NU : CUMap) {
1423 DwarfCompileUnit *TheU = NU.second;
1425 const auto &Globals = (TheU->*Accessor)();
1427 if (Globals.empty())
1430 if (auto *Skeleton = TheU->getSkeleton())
1433 // Start the dwarf pubnames section.
1434 Asm->OutStreamer->SwitchSection(PSec);
1437 Asm->OutStreamer->AddComment("Length of Public " + Name + " Info");
1438 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1439 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1440 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1442 Asm->OutStreamer->EmitLabel(BeginLabel);
1444 Asm->OutStreamer->AddComment("DWARF Version");
1445 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1447 Asm->OutStreamer->AddComment("Offset of Compilation Unit Info");
1448 Asm->emitDwarfSymbolReference(TheU->getLabelBegin());
1450 Asm->OutStreamer->AddComment("Compilation Unit Length");
1451 Asm->EmitInt32(TheU->getLength());
1453 // Emit the pubnames for this compilation unit.
1454 for (const auto &GI : Globals) {
1455 const char *Name = GI.getKeyData();
1456 const DIE *Entity = GI.second;
1458 Asm->OutStreamer->AddComment("DIE offset");
1459 Asm->EmitInt32(Entity->getOffset());
1462 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1463 Asm->OutStreamer->AddComment(
1464 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1465 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1466 Asm->EmitInt8(Desc.toBits());
1469 Asm->OutStreamer->AddComment("External Name");
1470 Asm->OutStreamer->EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1473 Asm->OutStreamer->AddComment("End Mark");
1475 Asm->OutStreamer->EmitLabel(EndLabel);
1479 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1480 MCSection *PSec = GnuStyle
1481 ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1482 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1484 emitDebugPubSection(GnuStyle, PSec, "Types",
1485 &DwarfCompileUnit::getGlobalTypes);
1488 // Emit visible names into a debug str section.
1489 void DwarfDebug::emitDebugStr() {
1490 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1491 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1494 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1495 const DebugLocStream::Entry &Entry) {
1496 auto &&Comments = DebugLocs.getComments(Entry);
1497 auto Comment = Comments.begin();
1498 auto End = Comments.end();
1499 for (uint8_t Byte : DebugLocs.getBytes(Entry))
1500 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1503 static void emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
1504 ByteStreamer &Streamer,
1505 const DebugLocEntry::Value &Value,
1506 unsigned PieceOffsetInBits) {
1507 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1508 AP.getDwarfDebug()->getDwarfVersion(),
1511 if (Value.isInt()) {
1512 if (BT && (BT->getEncoding() == dwarf::DW_ATE_signed ||
1513 BT->getEncoding() == dwarf::DW_ATE_signed_char))
1514 DwarfExpr.AddSignedConstant(Value.getInt());
1516 DwarfExpr.AddUnsignedConstant(Value.getInt());
1517 } else if (Value.isLocation()) {
1518 MachineLocation Loc = Value.getLoc();
1519 const DIExpression *Expr = Value.getExpression();
1520 if (!Expr || !Expr->getNumElements())
1522 AP.EmitDwarfRegOp(Streamer, Loc);
1524 // Complex address entry.
1525 if (Loc.getOffset()) {
1526 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1527 DwarfExpr.AddExpression(Expr->expr_op_begin(), Expr->expr_op_end(),
1530 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1534 // else ... ignore constant fp. There is not any good way to
1535 // to represent them here in dwarf.
1539 void DebugLocEntry::finalize(const AsmPrinter &AP,
1540 DebugLocStream::ListBuilder &List,
1541 const DIBasicType *BT) {
1542 DebugLocStream::EntryBuilder Entry(List, Begin, End);
1543 BufferByteStreamer Streamer = Entry.getStreamer();
1544 const DebugLocEntry::Value &Value = Values[0];
1545 if (Value.isBitPiece()) {
1546 // Emit all pieces that belong to the same variable and range.
1547 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1548 return P.isBitPiece();
1549 }) && "all values are expected to be pieces");
1550 assert(std::is_sorted(Values.begin(), Values.end()) &&
1551 "pieces are expected to be sorted");
1553 unsigned Offset = 0;
1554 for (auto Piece : Values) {
1555 const DIExpression *Expr = Piece.getExpression();
1556 unsigned PieceOffset = Expr->getBitPieceOffset();
1557 unsigned PieceSize = Expr->getBitPieceSize();
1558 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1559 if (Offset < PieceOffset) {
1560 // The DWARF spec seriously mandates pieces with no locations for gaps.
1561 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1562 AP.getDwarfDebug()->getDwarfVersion(),
1564 Expr.AddOpPiece(PieceOffset-Offset, 0);
1565 Offset += PieceOffset-Offset;
1567 Offset += PieceSize;
1569 emitDebugLocValue(AP, BT, Streamer, Piece, PieceOffset);
1572 assert(Values.size() == 1 && "only pieces may have >1 value");
1573 emitDebugLocValue(AP, BT, Streamer, Value, 0);
1577 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry) {
1579 Asm->OutStreamer->AddComment("Loc expr size");
1580 Asm->EmitInt16(DebugLocs.getBytes(Entry).size());
1583 APByteStreamer Streamer(*Asm);
1584 emitDebugLocEntry(Streamer, Entry);
1587 // Emit locations into the debug loc section.
1588 void DwarfDebug::emitDebugLoc() {
1589 // Start the dwarf loc section.
1590 Asm->OutStreamer->SwitchSection(
1591 Asm->getObjFileLowering().getDwarfLocSection());
1592 unsigned char Size = Asm->getDataLayout().getPointerSize();
1593 for (const auto &List : DebugLocs.getLists()) {
1594 Asm->OutStreamer->EmitLabel(List.Label);
1595 const DwarfCompileUnit *CU = List.CU;
1596 for (const auto &Entry : DebugLocs.getEntries(List)) {
1597 // Set up the range. This range is relative to the entry point of the
1598 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1599 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1600 if (auto *Base = CU->getBaseAddress()) {
1601 Asm->EmitLabelDifference(Entry.BeginSym, Base, Size);
1602 Asm->EmitLabelDifference(Entry.EndSym, Base, Size);
1604 Asm->OutStreamer->EmitSymbolValue(Entry.BeginSym, Size);
1605 Asm->OutStreamer->EmitSymbolValue(Entry.EndSym, Size);
1608 emitDebugLocEntryLocation(Entry);
1610 Asm->OutStreamer->EmitIntValue(0, Size);
1611 Asm->OutStreamer->EmitIntValue(0, Size);
1615 void DwarfDebug::emitDebugLocDWO() {
1616 Asm->OutStreamer->SwitchSection(
1617 Asm->getObjFileLowering().getDwarfLocDWOSection());
1618 for (const auto &List : DebugLocs.getLists()) {
1619 Asm->OutStreamer->EmitLabel(List.Label);
1620 for (const auto &Entry : DebugLocs.getEntries(List)) {
1621 // Just always use start_length for now - at least that's one address
1622 // rather than two. We could get fancier and try to, say, reuse an
1623 // address we know we've emitted elsewhere (the start of the function?
1624 // The start of the CU or CU subrange that encloses this range?)
1625 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1626 unsigned idx = AddrPool.getIndex(Entry.BeginSym);
1627 Asm->EmitULEB128(idx);
1628 Asm->EmitLabelDifference(Entry.EndSym, Entry.BeginSym, 4);
1630 emitDebugLocEntryLocation(Entry);
1632 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1637 const MCSymbol *Start, *End;
1640 // Emit a debug aranges section, containing a CU lookup for any
1641 // address we can tie back to a CU.
1642 void DwarfDebug::emitDebugARanges() {
1643 // Provides a unique id per text section.
1644 MapVector<MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1646 // Filter labels by section.
1647 for (const SymbolCU &SCU : ArangeLabels) {
1648 if (SCU.Sym->isInSection()) {
1649 // Make a note of this symbol and it's section.
1650 MCSection *Section = &SCU.Sym->getSection();
1651 if (!Section->getKind().isMetadata())
1652 SectionMap[Section].push_back(SCU);
1654 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1655 // appear in the output. This sucks as we rely on sections to build
1656 // arange spans. We can do it without, but it's icky.
1657 SectionMap[nullptr].push_back(SCU);
1661 // Add terminating symbols for each section.
1662 for (const auto &I : SectionMap) {
1663 MCSection *Section = I.first;
1664 MCSymbol *Sym = nullptr;
1667 Sym = Asm->OutStreamer->endSection(Section);
1669 // Insert a final terminator.
1670 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1673 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1675 for (auto &I : SectionMap) {
1676 const MCSection *Section = I.first;
1677 SmallVector<SymbolCU, 8> &List = I.second;
1678 if (List.size() < 2)
1681 // If we have no section (e.g. common), just write out
1682 // individual spans for each symbol.
1684 for (const SymbolCU &Cur : List) {
1686 Span.Start = Cur.Sym;
1689 Spans[Cur.CU].push_back(Span);
1694 // Sort the symbols by offset within the section.
1695 std::sort(List.begin(), List.end(),
1696 [&](const SymbolCU &A, const SymbolCU &B) {
1697 unsigned IA = A.Sym ? Asm->OutStreamer->GetSymbolOrder(A.Sym) : 0;
1698 unsigned IB = B.Sym ? Asm->OutStreamer->GetSymbolOrder(B.Sym) : 0;
1700 // Symbols with no order assigned should be placed at the end.
1701 // (e.g. section end labels)
1709 // Build spans between each label.
1710 const MCSymbol *StartSym = List[0].Sym;
1711 for (size_t n = 1, e = List.size(); n < e; n++) {
1712 const SymbolCU &Prev = List[n - 1];
1713 const SymbolCU &Cur = List[n];
1715 // Try and build the longest span we can within the same CU.
1716 if (Cur.CU != Prev.CU) {
1718 Span.Start = StartSym;
1720 Spans[Prev.CU].push_back(Span);
1726 // Start the dwarf aranges section.
1727 Asm->OutStreamer->SwitchSection(
1728 Asm->getObjFileLowering().getDwarfARangesSection());
1730 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1732 // Build a list of CUs used.
1733 std::vector<DwarfCompileUnit *> CUs;
1734 for (const auto &it : Spans) {
1735 DwarfCompileUnit *CU = it.first;
1739 // Sort the CU list (again, to ensure consistent output order).
1740 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1741 return A->getUniqueID() < B->getUniqueID();
1744 // Emit an arange table for each CU we used.
1745 for (DwarfCompileUnit *CU : CUs) {
1746 std::vector<ArangeSpan> &List = Spans[CU];
1748 // Describe the skeleton CU's offset and length, not the dwo file's.
1749 if (auto *Skel = CU->getSkeleton())
1752 // Emit size of content not including length itself.
1753 unsigned ContentSize =
1754 sizeof(int16_t) + // DWARF ARange version number
1755 sizeof(int32_t) + // Offset of CU in the .debug_info section
1756 sizeof(int8_t) + // Pointer Size (in bytes)
1757 sizeof(int8_t); // Segment Size (in bytes)
1759 unsigned TupleSize = PtrSize * 2;
1761 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1763 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1765 ContentSize += Padding;
1766 ContentSize += (List.size() + 1) * TupleSize;
1768 // For each compile unit, write the list of spans it covers.
1769 Asm->OutStreamer->AddComment("Length of ARange Set");
1770 Asm->EmitInt32(ContentSize);
1771 Asm->OutStreamer->AddComment("DWARF Arange version number");
1772 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1773 Asm->OutStreamer->AddComment("Offset Into Debug Info Section");
1774 Asm->emitDwarfSymbolReference(CU->getLabelBegin());
1775 Asm->OutStreamer->AddComment("Address Size (in bytes)");
1776 Asm->EmitInt8(PtrSize);
1777 Asm->OutStreamer->AddComment("Segment Size (in bytes)");
1780 Asm->OutStreamer->EmitFill(Padding, 0xff);
1782 for (const ArangeSpan &Span : List) {
1783 Asm->EmitLabelReference(Span.Start, PtrSize);
1785 // Calculate the size as being from the span start to it's end.
1787 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1789 // For symbols without an end marker (e.g. common), we
1790 // write a single arange entry containing just that one symbol.
1791 uint64_t Size = SymSize[Span.Start];
1795 Asm->OutStreamer->EmitIntValue(Size, PtrSize);
1799 Asm->OutStreamer->AddComment("ARange terminator");
1800 Asm->OutStreamer->EmitIntValue(0, PtrSize);
1801 Asm->OutStreamer->EmitIntValue(0, PtrSize);
1805 // Emit visible names into a debug ranges section.
1806 void DwarfDebug::emitDebugRanges() {
1807 // Start the dwarf ranges section.
1808 Asm->OutStreamer->SwitchSection(
1809 Asm->getObjFileLowering().getDwarfRangesSection());
1811 // Size for our labels.
1812 unsigned char Size = Asm->getDataLayout().getPointerSize();
1814 // Grab the specific ranges for the compile units in the module.
1815 for (const auto &I : CUMap) {
1816 DwarfCompileUnit *TheCU = I.second;
1818 if (auto *Skel = TheCU->getSkeleton())
1821 // Iterate over the misc ranges for the compile units in the module.
1822 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1823 // Emit our symbol so we can find the beginning of the range.
1824 Asm->OutStreamer->EmitLabel(List.getSym());
1826 for (const RangeSpan &Range : List.getRanges()) {
1827 const MCSymbol *Begin = Range.getStart();
1828 const MCSymbol *End = Range.getEnd();
1829 assert(Begin && "Range without a begin symbol?");
1830 assert(End && "Range without an end symbol?");
1831 if (auto *Base = TheCU->getBaseAddress()) {
1832 Asm->EmitLabelDifference(Begin, Base, Size);
1833 Asm->EmitLabelDifference(End, Base, Size);
1835 Asm->OutStreamer->EmitSymbolValue(Begin, Size);
1836 Asm->OutStreamer->EmitSymbolValue(End, Size);
1840 // And terminate the list with two 0 values.
1841 Asm->OutStreamer->EmitIntValue(0, Size);
1842 Asm->OutStreamer->EmitIntValue(0, Size);
1847 // DWARF5 Experimental Separate Dwarf emitters.
1849 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1850 std::unique_ptr<DwarfUnit> NewU) {
1851 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1852 U.getCUNode()->getSplitDebugFilename());
1854 if (!CompilationDir.empty())
1855 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1857 addGnuPubAttributes(*NewU, Die);
1859 SkeletonHolder.addUnit(std::move(NewU));
1862 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1863 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1864 // DW_AT_addr_base, DW_AT_ranges_base.
1865 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1867 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1868 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1869 DwarfCompileUnit &NewCU = *OwnedUnit;
1870 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1872 NewCU.initStmtList();
1874 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1879 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1880 // compile units that would normally be in debug_info.
1881 void DwarfDebug::emitDebugInfoDWO() {
1882 assert(useSplitDwarf() && "No split dwarf debug info?");
1883 // Don't emit relocations into the dwo file.
1884 InfoHolder.emitUnits(/* UseOffsets */ true);
1887 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1888 // abbreviations for the .debug_info.dwo section.
1889 void DwarfDebug::emitDebugAbbrevDWO() {
1890 assert(useSplitDwarf() && "No split dwarf?");
1891 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1894 void DwarfDebug::emitDebugLineDWO() {
1895 assert(useSplitDwarf() && "No split dwarf?");
1896 Asm->OutStreamer->SwitchSection(
1897 Asm->getObjFileLowering().getDwarfLineDWOSection());
1898 SplitTypeUnitFileTable.Emit(*Asm->OutStreamer, MCDwarfLineTableParams());
1901 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1902 // string section and is identical in format to traditional .debug_str
1904 void DwarfDebug::emitDebugStrDWO() {
1905 assert(useSplitDwarf() && "No split dwarf?");
1906 MCSection *OffSec = Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1907 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1911 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1912 if (!useSplitDwarf())
1915 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode()->getDirectory());
1916 return &SplitTypeUnitFileTable;
1919 uint64_t DwarfDebug::makeTypeSignature(StringRef Identifier) {
1921 Hash.update(Identifier);
1922 // ... take the least significant 8 bytes and return those. Our MD5
1923 // implementation always returns its results in little endian, swap bytes
1925 MD5::MD5Result Result;
1927 return support::endian::read64le(Result + 8);
1930 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1931 StringRef Identifier, DIE &RefDie,
1932 const DICompositeType *CTy) {
1933 // Fast path if we're building some type units and one has already used the
1934 // address pool we know we're going to throw away all this work anyway, so
1935 // don't bother building dependent types.
1936 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1939 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1941 CU.addDIETypeSignature(RefDie, *TU);
1945 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1946 AddrPool.resetUsedFlag();
1948 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1949 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1950 this, &InfoHolder, getDwoLineTable(CU));
1951 DwarfTypeUnit &NewTU = *OwnedUnit;
1952 DIE &UnitDie = NewTU.getUnitDie();
1954 TypeUnitsUnderConstruction.push_back(
1955 std::make_pair(std::move(OwnedUnit), CTy));
1957 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1960 uint64_t Signature = makeTypeSignature(Identifier);
1961 NewTU.setTypeSignature(Signature);
1963 if (useSplitDwarf())
1964 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1966 CU.applyStmtList(UnitDie);
1968 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1971 NewTU.setType(NewTU.createTypeDIE(CTy));
1974 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1975 TypeUnitsUnderConstruction.clear();
1977 // Types referencing entries in the address table cannot be placed in type
1979 if (AddrPool.hasBeenUsed()) {
1981 // Remove all the types built while building this type.
1982 // This is pessimistic as some of these types might not be dependent on
1983 // the type that used an address.
1984 for (const auto &TU : TypeUnitsToAdd)
1985 DwarfTypeUnits.erase(TU.second);
1987 // Construct this type in the CU directly.
1988 // This is inefficient because all the dependent types will be rebuilt
1989 // from scratch, including building them in type units, discovering that
1990 // they depend on addresses, throwing them out and rebuilding them.
1991 CU.constructTypeDIE(RefDie, cast<DICompositeType>(CTy));
1995 // If the type wasn't dependent on fission addresses, finish adding the type
1996 // and all its dependent types.
1997 for (auto &TU : TypeUnitsToAdd)
1998 InfoHolder.addUnit(std::move(TU.first));
2000 CU.addDIETypeSignature(RefDie, NewTU);
2003 // Accelerator table mutators - add each name along with its companion
2004 // DIE to the proper table while ensuring that the name that we're going
2005 // to reference is in the string table. We do this since the names we
2006 // add may not only be identical to the names in the DIE.
2007 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2008 if (!useDwarfAccelTables())
2010 AccelNames.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
2013 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2014 if (!useDwarfAccelTables())
2016 AccelObjC.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
2019 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2020 if (!useDwarfAccelTables())
2022 AccelNamespace.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
2025 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2026 if (!useDwarfAccelTables())
2028 AccelTypes.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);