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1 //===- llvm/CodeGen/DwarfDebug.h - Dwarf Debug Framework --------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains support for writing dwarf debug info into asm files.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFDEBUG_H
15 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFDEBUG_H
16 
17 #include "AddressPool.h"
18 #include "DbgValueHistoryCalculator.h"
19 #include "DebugHandlerBase.h"
20 #include "DebugLocStream.h"
21 #include "DwarfFile.h"
22 #include "llvm/ADT/ArrayRef.h"
23 #include "llvm/ADT/DenseMap.h"
24 #include "llvm/ADT/DenseSet.h"
25 #include "llvm/ADT/MapVector.h"
26 #include "llvm/ADT/STLExtras.h"
27 #include "llvm/ADT/SetVector.h"
28 #include "llvm/ADT/SmallPtrSet.h"
29 #include "llvm/ADT/SmallVector.h"
30 #include "llvm/ADT/StringMap.h"
31 #include "llvm/ADT/StringRef.h"
32 #include "llvm/BinaryFormat/Dwarf.h"
33 #include "llvm/CodeGen/AccelTable.h"
34 #include "llvm/CodeGen/MachineInstr.h"
35 #include "llvm/IR/DebugInfoMetadata.h"
36 #include "llvm/IR/DebugLoc.h"
37 #include "llvm/IR/Metadata.h"
38 #include "llvm/MC/MCDwarf.h"
39 #include "llvm/Support/Allocator.h"
40 #include "llvm/Target/TargetOptions.h"
41 #include <cassert>
42 #include <cstdint>
43 #include <limits>
44 #include <memory>
45 #include <utility>
46 #include <vector>
47 
48 namespace llvm {
49 
50 class AsmPrinter;
51 class ByteStreamer;
52 class DebugLocEntry;
53 class DIE;
54 class DwarfCompileUnit;
55 class DwarfTypeUnit;
56 class DwarfUnit;
57 class LexicalScope;
58 class MachineFunction;
59 class MCSection;
60 class MCSymbol;
61 class MDNode;
62 class Module;
63 
64 //===----------------------------------------------------------------------===//
65 /// This class is used to track local variable information.
66 ///
67 /// Variables can be created from allocas, in which case they're generated from
68 /// the MMI table.  Such variables can have multiple expressions and frame
69 /// indices.
70 ///
71 /// Variables can be created from \c DBG_VALUE instructions.  Those whose
72 /// location changes over time use \a DebugLocListIndex, while those with a
73 /// single instruction use \a MInsn and (optionally) a single entry of \a Expr.
74 ///
75 /// Variables that have been optimized out use none of these fields.
76 class DbgVariable {
77   const DILocalVariable *Var;                /// Variable Descriptor.
78   const DILocation *IA;                      /// Inlined at location.
79   DIE *TheDIE = nullptr;                     /// Variable DIE.
80   unsigned DebugLocListIndex = ~0u;          /// Offset in DebugLocs.
81   const MachineInstr *MInsn = nullptr;       /// DBG_VALUE instruction.
82 
83   struct FrameIndexExpr {
84     int FI;
85     const DIExpression *Expr;
86   };
87   mutable SmallVector<FrameIndexExpr, 1>
88       FrameIndexExprs; /// Frame index + expression.
89 
90 public:
91   /// Construct a DbgVariable.
92   ///
93   /// Creates a variable without any DW_AT_location.  Call \a initializeMMI()
94   /// for MMI entries, or \a initializeDbgValue() for DBG_VALUE instructions.
DbgVariable(const DILocalVariable * V,const DILocation * IA)95   DbgVariable(const DILocalVariable *V, const DILocation *IA)
96       : Var(V), IA(IA) {}
97 
98   /// Initialize from the MMI table.
initializeMMI(const DIExpression * E,int FI)99   void initializeMMI(const DIExpression *E, int FI) {
100     assert(FrameIndexExprs.empty() && "Already initialized?");
101     assert(!MInsn && "Already initialized?");
102 
103     assert((!E || E->isValid()) && "Expected valid expression");
104     assert(FI != std::numeric_limits<int>::max() && "Expected valid index");
105 
106     FrameIndexExprs.push_back({FI, E});
107   }
108 
109   /// Initialize from a DBG_VALUE instruction.
initializeDbgValue(const MachineInstr * DbgValue)110   void initializeDbgValue(const MachineInstr *DbgValue) {
111     assert(FrameIndexExprs.empty() && "Already initialized?");
112     assert(!MInsn && "Already initialized?");
113 
114     assert(Var == DbgValue->getDebugVariable() && "Wrong variable");
115     assert(IA == DbgValue->getDebugLoc()->getInlinedAt() && "Wrong inlined-at");
116 
117     MInsn = DbgValue;
118     if (auto *E = DbgValue->getDebugExpression())
119       if (E->getNumElements())
120         FrameIndexExprs.push_back({0, E});
121   }
122 
123   // Accessors.
getVariable()124   const DILocalVariable *getVariable() const { return Var; }
getInlinedAt()125   const DILocation *getInlinedAt() const { return IA; }
126 
getSingleExpression()127   const DIExpression *getSingleExpression() const {
128     assert(MInsn && FrameIndexExprs.size() <= 1);
129     return FrameIndexExprs.size() ? FrameIndexExprs[0].Expr : nullptr;
130   }
131 
setDIE(DIE & D)132   void setDIE(DIE &D) { TheDIE = &D; }
getDIE()133   DIE *getDIE() const { return TheDIE; }
setDebugLocListIndex(unsigned O)134   void setDebugLocListIndex(unsigned O) { DebugLocListIndex = O; }
getDebugLocListIndex()135   unsigned getDebugLocListIndex() const { return DebugLocListIndex; }
getName()136   StringRef getName() const { return Var->getName(); }
getMInsn()137   const MachineInstr *getMInsn() const { return MInsn; }
138   /// Get the FI entries, sorted by fragment offset.
139   ArrayRef<FrameIndexExpr> getFrameIndexExprs() const;
hasFrameIndexExprs()140   bool hasFrameIndexExprs() const { return !FrameIndexExprs.empty(); }
141   void addMMIEntry(const DbgVariable &V);
142 
143   // Translate tag to proper Dwarf tag.
getTag()144   dwarf::Tag getTag() const {
145     // FIXME: Why don't we just infer this tag and store it all along?
146     if (Var->isParameter())
147       return dwarf::DW_TAG_formal_parameter;
148 
149     return dwarf::DW_TAG_variable;
150   }
151 
152   /// Return true if DbgVariable is artificial.
isArtificial()153   bool isArtificial() const {
154     if (Var->isArtificial())
155       return true;
156     if (getType()->isArtificial())
157       return true;
158     return false;
159   }
160 
isObjectPointer()161   bool isObjectPointer() const {
162     if (Var->isObjectPointer())
163       return true;
164     if (getType()->isObjectPointer())
165       return true;
166     return false;
167   }
168 
hasComplexAddress()169   bool hasComplexAddress() const {
170     assert(MInsn && "Expected DBG_VALUE, not MMI variable");
171     assert((FrameIndexExprs.empty() ||
172             (FrameIndexExprs.size() == 1 &&
173              FrameIndexExprs[0].Expr->getNumElements())) &&
174            "Invalid Expr for DBG_VALUE");
175     return !FrameIndexExprs.empty();
176   }
177 
178   bool isBlockByrefVariable() const;
179   const DIType *getType() const;
180 
181 private:
resolve(TypedDINodeRef<T> Ref)182   template <typename T> T *resolve(TypedDINodeRef<T> Ref) const {
183     return Ref.resolve();
184   }
185 };
186 
187 /// Helper used to pair up a symbol and its DWARF compile unit.
188 struct SymbolCU {
SymbolCUSymbolCU189   SymbolCU(DwarfCompileUnit *CU, const MCSymbol *Sym) : Sym(Sym), CU(CU) {}
190 
191   const MCSymbol *Sym;
192   DwarfCompileUnit *CU;
193 };
194 
195 /// The kind of accelerator tables we should emit.
196 enum class AccelTableKind {
197   Default, ///< Platform default.
198   None,    ///< None.
199   Apple,   ///< .apple_names, .apple_namespaces, .apple_types, .apple_objc.
200   Dwarf,   ///< DWARF v5 .debug_names.
201 };
202 
203 /// Collects and handles dwarf debug information.
204 class DwarfDebug : public DebugHandlerBase {
205   /// All DIEValues are allocated through this allocator.
206   BumpPtrAllocator DIEValueAllocator;
207 
208   /// Maps MDNode with its corresponding DwarfCompileUnit.
209   MapVector<const MDNode *, DwarfCompileUnit *> CUMap;
210 
211   /// Maps a CU DIE with its corresponding DwarfCompileUnit.
212   DenseMap<const DIE *, DwarfCompileUnit *> CUDieMap;
213 
214   /// List of all labels used in aranges generation.
215   std::vector<SymbolCU> ArangeLabels;
216 
217   /// Size of each symbol emitted (for those symbols that have a specific size).
218   DenseMap<const MCSymbol *, uint64_t> SymSize;
219 
220   /// Collection of abstract variables.
221   SmallVector<std::unique_ptr<DbgVariable>, 64> ConcreteVariables;
222 
223   /// Collection of DebugLocEntry. Stored in a linked list so that DIELocLists
224   /// can refer to them in spite of insertions into this list.
225   DebugLocStream DebugLocs;
226 
227   /// This is a collection of subprogram MDNodes that are processed to
228   /// create DIEs.
229   SetVector<const DISubprogram *, SmallVector<const DISubprogram *, 16>,
230             SmallPtrSet<const DISubprogram *, 16>>
231       ProcessedSPNodes;
232 
233   /// If nonnull, stores the current machine function we're processing.
234   const MachineFunction *CurFn = nullptr;
235 
236   /// If nonnull, stores the CU in which the previous subprogram was contained.
237   const DwarfCompileUnit *PrevCU;
238 
239   /// As an optimization, there is no need to emit an entry in the directory
240   /// table for the same directory as DW_AT_comp_dir.
241   StringRef CompilationDir;
242 
243   /// Holder for the file specific debug information.
244   DwarfFile InfoHolder;
245 
246   /// Holders for the various debug information flags that we might need to
247   /// have exposed. See accessor functions below for description.
248 
249   /// Map from MDNodes for user-defined types to their type signatures. Also
250   /// used to keep track of which types we have emitted type units for.
251   DenseMap<const MDNode *, uint64_t> TypeSignatures;
252 
253   SmallVector<
254       std::pair<std::unique_ptr<DwarfTypeUnit>, const DICompositeType *>, 1>
255       TypeUnitsUnderConstruction;
256 
257   /// Whether to use the GNU TLS opcode (instead of the standard opcode).
258   bool UseGNUTLSOpcode;
259 
260   /// Whether to use DWARF 2 bitfields (instead of the DWARF 4 format).
261   bool UseDWARF2Bitfields;
262 
263   /// Whether to emit all linkage names, or just abstract subprograms.
264   bool UseAllLinkageNames;
265 
266   /// Use inlined strings.
267   bool UseInlineStrings = false;
268 
269   /// Whether to emit DWARF pub sections or not.
270   bool UsePubSections = true;
271 
272   /// Allow emission of .debug_ranges section.
273   bool UseRangesSection = true;
274 
275   /// True if the sections itself must be used as references and don't create
276   /// temp symbols inside DWARF sections.
277   bool UseSectionsAsReferences = false;
278 
279   ///Allow emission of the .debug_loc section.
280   bool UseLocSection = true;
281 
282   /// Generate DWARF v4 type units.
283   bool GenerateTypeUnits;
284 
285   /// DWARF5 Experimental Options
286   /// @{
287   AccelTableKind TheAccelTableKind;
288   bool HasAppleExtensionAttributes;
289   bool HasSplitDwarf;
290 
291   /// Whether to generate the DWARF v5 string offsets table.
292   /// It consists of a series of contributions, each preceded by a header.
293   /// The pre-DWARF v5 string offsets table for split dwarf is, in contrast,
294   /// a monolithic sequence of string offsets.
295   bool UseSegmentedStringOffsetsTable;
296 
297   /// Separated Dwarf Variables
298   /// In general these will all be for bits that are left in the
299   /// original object file, rather than things that are meant
300   /// to be in the .dwo sections.
301 
302   /// Holder for the skeleton information.
303   DwarfFile SkeletonHolder;
304 
305   /// Store file names for type units under fission in a line table
306   /// header that will be emitted into debug_line.dwo.
307   // FIXME: replace this with a map from comp_dir to table so that we
308   // can emit multiple tables during LTO each of which uses directory
309   // 0, referencing the comp_dir of all the type units that use it.
310   MCDwarfDwoLineTable SplitTypeUnitFileTable;
311   /// @}
312 
313   /// True iff there are multiple CUs in this module.
314   bool SingleCU;
315   bool IsDarwin;
316 
317   AddressPool AddrPool;
318 
319   /// Accelerator tables.
320   AccelTable<DWARF5AccelTableData> AccelDebugNames;
321   AccelTable<AppleAccelTableOffsetData> AccelNames;
322   AccelTable<AppleAccelTableOffsetData> AccelObjC;
323   AccelTable<AppleAccelTableOffsetData> AccelNamespace;
324   AccelTable<AppleAccelTableTypeData> AccelTypes;
325 
326   // Identify a debugger for "tuning" the debug info.
327   DebuggerKind DebuggerTuning = DebuggerKind::Default;
328 
329   MCDwarfDwoLineTable *getDwoLineTable(const DwarfCompileUnit &);
330 
getUnits()331   const SmallVectorImpl<std::unique_ptr<DwarfCompileUnit>> &getUnits() {
332     return InfoHolder.getUnits();
333   }
334 
335   using InlinedVariable = DbgValueHistoryMap::InlinedVariable;
336 
337   void ensureAbstractVariableIsCreated(DwarfCompileUnit &CU, InlinedVariable IV,
338                                        const MDNode *Scope);
339   void ensureAbstractVariableIsCreatedIfScoped(DwarfCompileUnit &CU, InlinedVariable IV,
340                                                const MDNode *Scope);
341 
342   DbgVariable *createConcreteVariable(DwarfCompileUnit &TheCU,
343                                       LexicalScope &Scope, InlinedVariable IV);
344 
345   /// Construct a DIE for this abstract scope.
346   void constructAbstractSubprogramScopeDIE(DwarfCompileUnit &SrcCU, LexicalScope *Scope);
347 
348   template <typename DataT>
349   void addAccelNameImpl(AccelTable<DataT> &AppleAccel, StringRef Name,
350                         const DIE &Die);
351 
352   void finishVariableDefinitions();
353 
354   void finishSubprogramDefinitions();
355 
356   /// Finish off debug information after all functions have been
357   /// processed.
358   void finalizeModuleInfo();
359 
360   /// Emit the debug info section.
361   void emitDebugInfo();
362 
363   /// Emit the abbreviation section.
364   void emitAbbreviations();
365 
366   /// Emit the string offsets table header.
367   void emitStringOffsetsTableHeader();
368 
369   /// Emit a specified accelerator table.
370   template <typename AccelTableT>
371   void emitAccel(AccelTableT &Accel, MCSection *Section, StringRef TableName);
372 
373   /// Emit DWARF v5 accelerator table.
374   void emitAccelDebugNames();
375 
376   /// Emit visible names into a hashed accelerator table section.
377   void emitAccelNames();
378 
379   /// Emit objective C classes and categories into a hashed
380   /// accelerator table section.
381   void emitAccelObjC();
382 
383   /// Emit namespace dies into a hashed accelerator table.
384   void emitAccelNamespaces();
385 
386   /// Emit type dies into a hashed accelerator table.
387   void emitAccelTypes();
388 
389   /// Emit visible names and types into debug pubnames and pubtypes sections.
390   void emitDebugPubSections();
391 
392   void emitDebugPubSection(bool GnuStyle, StringRef Name,
393                            DwarfCompileUnit *TheU,
394                            const StringMap<const DIE *> &Globals);
395 
396   /// Emit null-terminated strings into a debug str section.
397   void emitDebugStr();
398 
399   /// Emit variable locations into a debug loc section.
400   void emitDebugLoc();
401 
402   /// Emit variable locations into a debug loc dwo section.
403   void emitDebugLocDWO();
404 
405   /// Emit address ranges into a debug aranges section.
406   void emitDebugARanges();
407 
408   /// Emit address ranges into a debug ranges section.
409   void emitDebugRanges();
410 
411   /// Emit range lists into a DWARF v5 debug rnglists section.
412   void emitDebugRnglists();
413 
414   /// Emit macros into a debug macinfo section.
415   void emitDebugMacinfo();
416   void emitMacro(DIMacro &M);
417   void emitMacroFile(DIMacroFile &F, DwarfCompileUnit &U);
418   void handleMacroNodes(DIMacroNodeArray Nodes, DwarfCompileUnit &U);
419 
420   /// DWARF 5 Experimental Split Dwarf Emitters
421 
422   /// Initialize common features of skeleton units.
423   void initSkeletonUnit(const DwarfUnit &U, DIE &Die,
424                         std::unique_ptr<DwarfCompileUnit> NewU);
425 
426   /// Construct the split debug info compile unit for the debug info section.
427   /// In DWARF v5, the skeleton unit DIE may have the following attributes:
428   /// DW_AT_addr_base, DW_AT_comp_dir, DW_AT_dwo_name, DW_AT_high_pc,
429   /// DW_AT_low_pc, DW_AT_ranges, DW_AT_stmt_list, and DW_AT_str_offsets_base.
430   /// Prior to DWARF v5 it may also have DW_AT_GNU_dwo_id. DW_AT_GNU_dwo_name
431   /// is used instead of DW_AT_dwo_name, Dw_AT_GNU_addr_base instead of
432   /// DW_AT_addr_base, and DW_AT_GNU_ranges_base instead of DW_AT_rnglists_base.
433   DwarfCompileUnit &constructSkeletonCU(const DwarfCompileUnit &CU);
434 
435   /// Emit the debug info dwo section.
436   void emitDebugInfoDWO();
437 
438   /// Emit the debug abbrev dwo section.
439   void emitDebugAbbrevDWO();
440 
441   /// Emit the debug line dwo section.
442   void emitDebugLineDWO();
443 
444   /// Emit the dwo stringoffsets table header.
445   void emitStringOffsetsTableHeaderDWO();
446 
447   /// Emit the debug str dwo section.
448   void emitDebugStrDWO();
449 
450   /// Emit DWO addresses.
451   void emitDebugAddr();
452 
453   /// Flags to let the linker know we have emitted new style pubnames. Only
454   /// emit it here if we don't have a skeleton CU for split dwarf.
455   void addGnuPubAttributes(DwarfCompileUnit &U, DIE &D) const;
456 
457   /// Create new DwarfCompileUnit for the given metadata node with tag
458   /// DW_TAG_compile_unit.
459   DwarfCompileUnit &getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit);
460 
461   /// Construct imported_module or imported_declaration DIE.
462   void constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
463                                         const DIImportedEntity *N);
464 
465   /// Register a source line with debug info. Returns the unique
466   /// label that was emitted and which provides correspondence to the
467   /// source line list.
468   void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
469                         unsigned Flags);
470 
471   /// Populate LexicalScope entries with variables' info.
472   void collectVariableInfo(DwarfCompileUnit &TheCU, const DISubprogram *SP,
473                            DenseSet<InlinedVariable> &ProcessedVars);
474 
475   /// Build the location list for all DBG_VALUEs in the
476   /// function that describe the same variable.
477   void buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
478                          const DbgValueHistoryMap::InstrRanges &Ranges);
479 
480   /// Collect variable information from the side table maintained by MF.
481   void collectVariableInfoFromMFTable(DwarfCompileUnit &TheCU,
482                                       DenseSet<InlinedVariable> &P);
483 
484   /// Emit the reference to the section.
485   void emitSectionReference(const DwarfCompileUnit &CU);
486 
487 protected:
488   /// Gather pre-function debug information.
489   void beginFunctionImpl(const MachineFunction *MF) override;
490 
491   /// Gather and emit post-function debug information.
492   void endFunctionImpl(const MachineFunction *MF) override;
493 
494   void skippedNonDebugFunction() override;
495 
496 public:
497   //===--------------------------------------------------------------------===//
498   // Main entry points.
499   //
500   DwarfDebug(AsmPrinter *A, Module *M);
501 
502   ~DwarfDebug() override;
503 
504   /// Emit all Dwarf sections that should come prior to the
505   /// content.
506   void beginModule();
507 
508   /// Emit all Dwarf sections that should come after the content.
509   void endModule() override;
510 
511   /// Process beginning of an instruction.
512   void beginInstruction(const MachineInstr *MI) override;
513 
514   /// Perform an MD5 checksum of \p Identifier and return the lower 64 bits.
515   static uint64_t makeTypeSignature(StringRef Identifier);
516 
517   /// Add a DIE to the set of types that we're going to pull into
518   /// type units.
519   void addDwarfTypeUnitType(DwarfCompileUnit &CU, StringRef Identifier,
520                             DIE &Die, const DICompositeType *CTy);
521 
522   /// Add a label so that arange data can be generated for it.
addArangeLabel(SymbolCU SCU)523   void addArangeLabel(SymbolCU SCU) { ArangeLabels.push_back(SCU); }
524 
525   /// For symbols that have a size designated (e.g. common symbols),
526   /// this tracks that size.
setSymbolSize(const MCSymbol * Sym,uint64_t Size)527   void setSymbolSize(const MCSymbol *Sym, uint64_t Size) override {
528     SymSize[Sym] = Size;
529   }
530 
531   /// Returns whether we should emit all DW_AT_[MIPS_]linkage_name.
532   /// If not, we still might emit certain cases.
useAllLinkageNames()533   bool useAllLinkageNames() const { return UseAllLinkageNames; }
534 
535   /// Returns whether to use DW_OP_GNU_push_tls_address, instead of the
536   /// standard DW_OP_form_tls_address opcode
useGNUTLSOpcode()537   bool useGNUTLSOpcode() const { return UseGNUTLSOpcode; }
538 
539   /// Returns whether to use the DWARF2 format for bitfields instyead of the
540   /// DWARF4 format.
useDWARF2Bitfields()541   bool useDWARF2Bitfields() const { return UseDWARF2Bitfields; }
542 
543   /// Returns whether to use inline strings.
useInlineStrings()544   bool useInlineStrings() const { return UseInlineStrings; }
545 
546   /// Returns whether GNU pub sections should be emitted.
usePubSections()547   bool usePubSections() const { return UsePubSections; }
548 
549   /// Returns whether ranges section should be emitted.
useRangesSection()550   bool useRangesSection() const { return UseRangesSection; }
551 
552   /// Returns whether to use sections as labels rather than temp symbols.
useSectionsAsReferences()553   bool useSectionsAsReferences() const {
554     return UseSectionsAsReferences;
555   }
556 
557   /// Returns whether .debug_loc section should be emitted.
useLocSection()558   bool useLocSection() const { return UseLocSection; }
559 
560   /// Returns whether to generate DWARF v4 type units.
generateTypeUnits()561   bool generateTypeUnits() const { return GenerateTypeUnits; }
562 
563   // Experimental DWARF5 features.
564 
565   /// Returns what kind (if any) of accelerator tables to emit.
getAccelTableKind()566   AccelTableKind getAccelTableKind() const { return TheAccelTableKind; }
567 
useAppleExtensionAttributes()568   bool useAppleExtensionAttributes() const {
569     return HasAppleExtensionAttributes;
570   }
571 
572   /// Returns whether or not to change the current debug info for the
573   /// split dwarf proposal support.
useSplitDwarf()574   bool useSplitDwarf() const { return HasSplitDwarf; }
575 
576   /// Returns whether to generate a string offsets table with (possibly shared)
577   /// contributions from each CU and type unit. This implies the use of
578   /// DW_FORM_strx* indirect references with DWARF v5 and beyond. Note that
579   /// DW_FORM_GNU_str_index is also an indirect reference, but it is used with
580   /// a pre-DWARF v5 implementation of split DWARF sections, which uses a
581   /// monolithic string offsets table.
useSegmentedStringOffsetsTable()582   bool useSegmentedStringOffsetsTable() const {
583     return UseSegmentedStringOffsetsTable;
584   }
585 
586   bool shareAcrossDWOCUs() const;
587 
588   /// Returns the Dwarf Version.
589   uint16_t getDwarfVersion() const;
590 
591   /// Returns the previous CU that was being updated
getPrevCU()592   const DwarfCompileUnit *getPrevCU() const { return PrevCU; }
setPrevCU(const DwarfCompileUnit * PrevCU)593   void setPrevCU(const DwarfCompileUnit *PrevCU) { this->PrevCU = PrevCU; }
594 
595   /// Returns the entries for the .debug_loc section.
getDebugLocs()596   const DebugLocStream &getDebugLocs() const { return DebugLocs; }
597 
598   /// Emit an entry for the debug loc section. This can be used to
599   /// handle an entry that's going to be emitted into the debug loc section.
600   void emitDebugLocEntry(ByteStreamer &Streamer,
601                          const DebugLocStream::Entry &Entry);
602 
603   /// Emit the location for a debug loc entry, including the size header.
604   void emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry);
605 
606   /// Find the MDNode for the given reference.
resolve(TypedDINodeRef<T> Ref)607   template <typename T> T *resolve(TypedDINodeRef<T> Ref) const {
608     return Ref.resolve();
609   }
610 
611   void addSubprogramNames(const DISubprogram *SP, DIE &Die);
612 
getAddressPool()613   AddressPool &getAddressPool() { return AddrPool; }
614 
615   void addAccelName(StringRef Name, const DIE &Die);
616 
617   void addAccelObjC(StringRef Name, const DIE &Die);
618 
619   void addAccelNamespace(StringRef Name, const DIE &Die);
620 
621   void addAccelType(StringRef Name, const DIE &Die, char Flags);
622 
getCurrentFunction()623   const MachineFunction *getCurrentFunction() const { return CurFn; }
624 
625   /// A helper function to check whether the DIE for a given Scope is
626   /// going to be null.
627   bool isLexicalScopeDIENull(LexicalScope *Scope);
628 
629   /// Find the matching DwarfCompileUnit for the given CU DIE.
lookupCU(const DIE * Die)630   DwarfCompileUnit *lookupCU(const DIE *Die) { return CUDieMap.lookup(Die); }
lookupCU(const DIE * Die)631   const DwarfCompileUnit *lookupCU(const DIE *Die) const {
632     return CUDieMap.lookup(Die);
633   }
634 
635   /// \defgroup DebuggerTuning Predicates to tune DWARF for a given debugger.
636   ///
637   /// Returns whether we are "tuning" for a given debugger.
638   /// @{
tuneForGDB()639   bool tuneForGDB() const { return DebuggerTuning == DebuggerKind::GDB; }
tuneForLLDB()640   bool tuneForLLDB() const { return DebuggerTuning == DebuggerKind::LLDB; }
tuneForSCE()641   bool tuneForSCE() const { return DebuggerTuning == DebuggerKind::SCE; }
642   /// @}
643 };
644 
645 } // end namespace llvm
646 
647 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFDEBUG_H
648