1 //===- llvm/CodeGen/DwarfDebug.h - Dwarf Debug Framework --------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains support for writing dwarf debug info into asm files.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFDEBUG_H
14 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFDEBUG_H
15
16 #include "AddressPool.h"
17 #include "DebugLocStream.h"
18 #include "DebugLocEntry.h"
19 #include "DwarfFile.h"
20 #include "llvm/ADT/ArrayRef.h"
21 #include "llvm/ADT/DenseMap.h"
22 #include "llvm/ADT/DenseSet.h"
23 #include "llvm/ADT/MapVector.h"
24 #include "llvm/ADT/STLExtras.h"
25 #include "llvm/ADT/SetVector.h"
26 #include "llvm/ADT/SmallPtrSet.h"
27 #include "llvm/ADT/SmallVector.h"
28 #include "llvm/ADT/StringMap.h"
29 #include "llvm/ADT/StringRef.h"
30 #include "llvm/BinaryFormat/Dwarf.h"
31 #include "llvm/CodeGen/AccelTable.h"
32 #include "llvm/CodeGen/DbgEntityHistoryCalculator.h"
33 #include "llvm/CodeGen/DebugHandlerBase.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 DIE;
53 class DwarfCompileUnit;
54 class DwarfExpression;
55 class DwarfTypeUnit;
56 class DwarfUnit;
57 class LexicalScope;
58 class MachineFunction;
59 class MCSection;
60 class MCSymbol;
61 class Module;
62
63 //===----------------------------------------------------------------------===//
64 /// This class is defined as the common parent of DbgVariable and DbgLabel
65 /// such that it could levarage polymorphism to extract common code for
66 /// DbgVariable and DbgLabel.
67 class DbgEntity {
68 const DINode *Entity;
69 const DILocation *InlinedAt;
70 DIE *TheDIE = nullptr;
71 unsigned SubclassID;
72
73 public:
74 enum DbgEntityKind {
75 DbgVariableKind,
76 DbgLabelKind
77 };
78
79 DbgEntity(const DINode *N, const DILocation *IA, unsigned ID)
80 : Entity(N), InlinedAt(IA), SubclassID(ID) {}
81 virtual ~DbgEntity() {}
82
83 /// Accessors.
84 /// @{
85 const DINode *getEntity() const { return Entity; }
86 const DILocation *getInlinedAt() const { return InlinedAt; }
87 DIE *getDIE() const { return TheDIE; }
88 unsigned getDbgEntityID() const { return SubclassID; }
89 /// @}
90
91 void setDIE(DIE &D) { TheDIE = &D; }
92
93 static bool classof(const DbgEntity *N) {
94 switch (N->getDbgEntityID()) {
95 default:
96 return false;
97 case DbgVariableKind:
98 case DbgLabelKind:
99 return true;
100 }
101 }
102 };
103
104 //===----------------------------------------------------------------------===//
105 /// This class is used to track local variable information.
106 ///
107 /// Variables can be created from allocas, in which case they're generated from
108 /// the MMI table. Such variables can have multiple expressions and frame
109 /// indices.
110 ///
111 /// Variables can be created from \c DBG_VALUE instructions. Those whose
112 /// location changes over time use \a DebugLocListIndex, while those with a
113 /// single location use \a ValueLoc and (optionally) a single entry of \a Expr.
114 ///
115 /// Variables that have been optimized out use none of these fields.
116 class DbgVariable : public DbgEntity {
117 /// Index of the entry list in DebugLocs.
118 unsigned DebugLocListIndex = ~0u;
119 /// DW_OP_LLVM_tag_offset value from DebugLocs.
120 Optional<uint8_t> DebugLocListTagOffset;
121
122 /// Single value location description.
123 std::unique_ptr<DbgValueLoc> ValueLoc = nullptr;
124
125 struct FrameIndexExpr {
126 int FI;
127 const DIExpression *Expr;
128 };
129 mutable SmallVector<FrameIndexExpr, 1>
130 FrameIndexExprs; /// Frame index + expression.
131
132 public:
133 /// Construct a DbgVariable.
134 ///
135 /// Creates a variable without any DW_AT_location. Call \a initializeMMI()
136 /// for MMI entries, or \a initializeDbgValue() for DBG_VALUE instructions.
137 DbgVariable(const DILocalVariable *V, const DILocation *IA)
138 : DbgEntity(V, IA, DbgVariableKind) {}
139
140 /// Initialize from the MMI table.
141 void initializeMMI(const DIExpression *E, int FI) {
142 assert(FrameIndexExprs.empty() && "Already initialized?");
143 assert(!ValueLoc.get() && "Already initialized?");
144
145 assert((!E || E->isValid()) && "Expected valid expression");
146 assert(FI != std::numeric_limits<int>::max() && "Expected valid index");
147
148 FrameIndexExprs.push_back({FI, E});
149 }
150
151 // Initialize variable's location.
152 void initializeDbgValue(DbgValueLoc Value) {
153 assert(FrameIndexExprs.empty() && "Already initialized?");
154 assert(!ValueLoc && "Already initialized?");
155 assert(!Value.getExpression()->isFragment() && "Fragments not supported.");
156
157 ValueLoc = std::make_unique<DbgValueLoc>(Value);
158 if (auto *E = ValueLoc->getExpression())
159 if (E->getNumElements())
160 FrameIndexExprs.push_back({0, E});
161 }
162
163 /// Initialize from a DBG_VALUE instruction.
164 void initializeDbgValue(const MachineInstr *DbgValue);
165
166 // Accessors.
167 const DILocalVariable *getVariable() const {
168 return cast<DILocalVariable>(getEntity());
169 }
170
171 const DIExpression *getSingleExpression() const {
172 assert(ValueLoc.get() && FrameIndexExprs.size() <= 1);
173 return FrameIndexExprs.size() ? FrameIndexExprs[0].Expr : nullptr;
174 }
175
emitOp(uint8_t Op,const char * Comment)176 void setDebugLocListIndex(unsigned O) { DebugLocListIndex = O; }
177 unsigned getDebugLocListIndex() const { return DebugLocListIndex; }
178 void setDebugLocListTagOffset(uint8_t O) { DebugLocListTagOffset = O; }
179 Optional<uint8_t> getDebugLocListTagOffset() const { return DebugLocListTagOffset; }
180 StringRef getName() const { return getVariable()->getName(); }
181 const DbgValueLoc *getValueLoc() const { return ValueLoc.get(); }
emitSigned(int64_t Value)182 /// Get the FI entries, sorted by fragment offset.
183 ArrayRef<FrameIndexExpr> getFrameIndexExprs() const;
184 bool hasFrameIndexExprs() const { return !FrameIndexExprs.empty(); }
185 void addMMIEntry(const DbgVariable &V);
emitUnsigned(uint64_t Value)186
187 // Translate tag to proper Dwarf tag.
188 dwarf::Tag getTag() const {
189 // FIXME: Why don't we just infer this tag and store it all along?
190 if (getVariable()->isParameter())
191 return dwarf::DW_TAG_formal_parameter;
192
193 return dwarf::DW_TAG_variable;
194 }
195
196 /// Return true if DbgVariable is artificial.
197 bool isArtificial() const {
198 if (getVariable()->isArtificial())
isFrameRegister(const TargetRegisterInfo & TRI,llvm::Register MachineReg)199 return true;
200 if (getType()->isArtificial())
201 return true;
202 return false;
203 }
204
enableTemporaryBuffer()205 bool isObjectPointer() const {
206 if (getVariable()->isObjectPointer())
207 return true;
208 if (getType()->isObjectPointer())
209 return true;
210 return false;
211 }
disableTemporaryBuffer()212
213 bool hasComplexAddress() const {
214 assert(ValueLoc.get() && "Expected DBG_VALUE, not MMI variable");
215 assert((FrameIndexExprs.empty() ||
216 (FrameIndexExprs.size() == 1 &&
217 FrameIndexExprs[0].Expr->getNumElements())) &&
218 "Invalid Expr for DBG_VALUE");
219 return !FrameIndexExprs.empty();
220 }
221
222 const DIType *getType() const;
223
224 static bool classof(const DbgEntity *N) {
225 return N->getDbgEntityID() == DbgVariableKind;
226 }
227 };
228
229 //===----------------------------------------------------------------------===//
230 /// This class is used to track label information.
getType() const231 ///
232 /// Labels are collected from \c DBG_LABEL instructions.
233 class DbgLabel : public DbgEntity {
234 const MCSymbol *Sym; /// Symbol before DBG_LABEL instruction.
235
236 public:
237 /// We need MCSymbol information to generate DW_AT_low_pc.
238 DbgLabel(const DILabel *L, const DILocation *IA, const MCSymbol *Sym = nullptr)
239 : DbgEntity(L, IA, DbgLabelKind), Sym(Sym) {}
240
241 /// Accessors.
242 /// @{
243 const DILabel *getLabel() const { return cast<DILabel>(getEntity()); }
244 const MCSymbol *getSymbol() const { return Sym; }
245
246 StringRef getName() const { return getLabel()->getName(); }
247 /// @}
248
249 /// Translate tag to proper Dwarf tag.
250 dwarf::Tag getTag() const {
251 return dwarf::DW_TAG_label;
252 }
253
254 static bool classof(const DbgEntity *N) {
255 return N->getDbgEntityID() == DbgLabelKind;
256 }
257 };
258
259 /// Used for tracking debug info about call site parameters.
260 class DbgCallSiteParam {
initializeDbgValue(const MachineInstr * DbgValue)261 private:
262 unsigned Register; ///< Parameter register at the callee entry point.
263 DbgValueLoc Value; ///< Corresponding location for the parameter value at
264 ///< the call site.
265 public:
266 DbgCallSiteParam(unsigned Reg, DbgValueLoc Val)
267 : Register(Reg), Value(Val) {
268 assert(Reg && "Parameter register cannot be undef");
269 }
270
271 unsigned getRegister() const { return Register; }
272 DbgValueLoc getValue() const { return Value; }
273 };
274
getFrameIndexExprs() const275 /// Collection used for storing debug call site parameters.
276 using ParamSet = SmallVector<DbgCallSiteParam, 4>;
277
278 /// Helper used to pair up a symbol and its DWARF compile unit.
279 struct SymbolCU {
__anon644faa090102(const FrameIndexExpr &A) 280 SymbolCU(DwarfCompileUnit *CU, const MCSymbol *Sym) : Sym(Sym), CU(CU) {}
281
282 const MCSymbol *Sym;
283 DwarfCompileUnit *CU;
284 };
__anon644faa090202(const FrameIndexExpr &A, const FrameIndexExpr &B) 285
286 /// The kind of accelerator tables we should emit.
287 enum class AccelTableKind {
288 Default, ///< Platform default.
289 None, ///< None.
290 Apple, ///< .apple_names, .apple_namespaces, .apple_types, .apple_objc.
291 Dwarf, ///< DWARF v5 .debug_names.
292 };
addMMIEntry(const DbgVariable & V)293
294 /// Collects and handles dwarf debug information.
295 class DwarfDebug : public DebugHandlerBase {
296 /// All DIEValues are allocated through this allocator.
297 BumpPtrAllocator DIEValueAllocator;
298
299 /// Maps MDNode with its corresponding DwarfCompileUnit.
300 MapVector<const MDNode *, DwarfCompileUnit *> CUMap;
301
302 /// Maps a CU DIE with its corresponding DwarfCompileUnit.
303 DenseMap<const DIE *, DwarfCompileUnit *> CUDieMap;
304
305 /// List of all labels used in aranges generation.
306 std::vector<SymbolCU> ArangeLabels;
307
308 /// Size of each symbol emitted (for those symbols that have a specific size).
309 DenseMap<const MCSymbol *, uint64_t> SymSize;
310
311 /// Collection of abstract variables/labels.
312 SmallVector<std::unique_ptr<DbgEntity>, 64> ConcreteEntities;
313
314 /// Collection of DebugLocEntry. Stored in a linked list so that DIELocLists
315 /// can refer to them in spite of insertions into this list.
316 DebugLocStream DebugLocs;
317
318 /// This is a collection of subprogram MDNodes that are processed to
319 /// create DIEs.
320 SetVector<const DISubprogram *, SmallVector<const DISubprogram *, 16>,
321 SmallPtrSet<const DISubprogram *, 16>>
322 ProcessedSPNodes;
323
324 /// If nonnull, stores the current machine function we're processing.
325 const MachineFunction *CurFn = nullptr;
326
327 /// If nonnull, stores the CU in which the previous subprogram was contained.
328 const DwarfCompileUnit *PrevCU = nullptr;
329
330 /// As an optimization, there is no need to emit an entry in the directory
331 /// table for the same directory as DW_AT_comp_dir.
332 StringRef CompilationDir;
333
334 /// Holder for the file specific debug information.
335 DwarfFile InfoHolder;
336
337 /// Holders for the various debug information flags that we might need to
338 /// have exposed. See accessor functions below for description.
339
340 /// Map from MDNodes for user-defined types to their type signatures. Also
341 /// used to keep track of which types we have emitted type units for.
342 DenseMap<const MDNode *, uint64_t> TypeSignatures;
343
344 DenseMap<const MCSection *, const MCSymbol *> SectionLabels;
345
346 SmallVector<
347 std::pair<std::unique_ptr<DwarfTypeUnit>, const DICompositeType *>, 1>
348 TypeUnitsUnderConstruction;
349
350 /// Whether to use the GNU TLS opcode (instead of the standard opcode).
351 bool UseGNUTLSOpcode;
352
353 /// Whether to use DWARF 2 bitfields (instead of the DWARF 4 format).
354 bool UseDWARF2Bitfields;
355
356 /// Whether to emit all linkage names, or just abstract subprograms.
357 bool UseAllLinkageNames;
358
359 /// Use inlined strings.
360 bool UseInlineStrings = false;
361
362 /// Allow emission of .debug_ranges section.
363 bool UseRangesSection = true;
364
365 /// True if the sections itself must be used as references and don't create
366 /// temp symbols inside DWARF sections.
367 bool UseSectionsAsReferences = false;
368
369 ///Allow emission of the .debug_loc section.
370 bool UseLocSection = true;
371
372 /// Generate DWARF v4 type units.
373 bool GenerateTypeUnits;
374
375 /// Emit a .debug_macro section instead of .debug_macinfo.
376 bool UseDebugMacroSection;
377
378 /// Avoid using DW_OP_convert due to consumer incompatibilities.
379 bool EnableOpConvert;
380
381 public:
382 enum class MinimizeAddrInV5 {
383 Default,
384 Disabled,
385 Ranges,
386 Expressions,
387 Form,
388 };
389
390 private:
391 /// Force the use of DW_AT_ranges even for single-entry range lists.
392 MinimizeAddrInV5 MinimizeAddr = MinimizeAddrInV5::Disabled;
393
394 /// DWARF5 Experimental Options
395 /// @{
396 AccelTableKind TheAccelTableKind;
397 bool HasAppleExtensionAttributes;
398 bool HasSplitDwarf;
399
400 /// Whether to generate the DWARF v5 string offsets table.
401 /// It consists of a series of contributions, each preceded by a header.
402 /// The pre-DWARF v5 string offsets table for split dwarf is, in contrast,
403 /// a monolithic sequence of string offsets.
404 bool UseSegmentedStringOffsetsTable;
405
406 /// Enable production of call site parameters needed to print the debug entry
407 /// values. Useful for testing purposes when a debugger does not support the
408 /// feature yet.
409 bool EmitDebugEntryValues;
410
411 /// Separated Dwarf Variables
412 /// In general these will all be for bits that are left in the
413 /// original object file, rather than things that are meant
414 /// to be in the .dwo sections.
415
416 /// Holder for the skeleton information.
417 DwarfFile SkeletonHolder;
418
419 /// Store file names for type units under fission in a line table
420 /// header that will be emitted into debug_line.dwo.
421 // FIXME: replace this with a map from comp_dir to table so that we
422 // can emit multiple tables during LTO each of which uses directory
423 // 0, referencing the comp_dir of all the type units that use it.
424 MCDwarfDwoLineTable SplitTypeUnitFileTable;
425 /// @}
426
427 /// True iff there are multiple CUs in this module.
428 bool SingleCU;
429 bool IsDarwin;
430
431 /// Map for tracking Fortran deferred CHARACTER lengths.
432 DenseMap<const DIStringType *, unsigned> StringTypeLocMap;
433
434 AddressPool AddrPool;
435
436 /// Accelerator tables.
437 AccelTable<DWARF5AccelTableData> AccelDebugNames;
438 AccelTable<AppleAccelTableOffsetData> AccelNames;
439 AccelTable<AppleAccelTableOffsetData> AccelObjC;
440 AccelTable<AppleAccelTableOffsetData> AccelNamespace;
441 AccelTable<AppleAccelTableTypeData> AccelTypes;
442
443 /// Identify a debugger for "tuning" the debug info.
444 ///
445 /// The "tuning" should be used to set defaults for individual feature flags
446 /// in DwarfDebug; if a given feature has a more specific command-line option,
447 /// that option should take precedence over the tuning.
448 DebuggerKind DebuggerTuning = DebuggerKind::Default;
449
450 MCDwarfDwoLineTable *getDwoLineTable(const DwarfCompileUnit &);
451
452 const SmallVectorImpl<std::unique_ptr<DwarfCompileUnit>> &getUnits() {
453 return InfoHolder.getUnits();
454 }
455
456 using InlinedEntity = DbgValueHistoryMap::InlinedEntity;
457
458 void ensureAbstractEntityIsCreated(DwarfCompileUnit &CU,
459 const DINode *Node,
460 const MDNode *Scope);
461 void ensureAbstractEntityIsCreatedIfScoped(DwarfCompileUnit &CU,
462 const DINode *Node,
463 const MDNode *Scope);
464
465 DbgEntity *createConcreteEntity(DwarfCompileUnit &TheCU,
466 LexicalScope &Scope,
467 const DINode *Node,
468 const DILocation *Location,
469 const MCSymbol *Sym = nullptr);
470
471 /// Construct a DIE for this abstract scope.
472 void constructAbstractSubprogramScopeDIE(DwarfCompileUnit &SrcCU, LexicalScope *Scope);
473
474 /// Construct DIEs for call site entries describing the calls in \p MF.
475 void constructCallSiteEntryDIEs(const DISubprogram &SP, DwarfCompileUnit &CU,
476 DIE &ScopeDIE, const MachineFunction &MF);
477
478 template <typename DataT>
479 void addAccelNameImpl(const DICompileUnit &CU, AccelTable<DataT> &AppleAccel,
480 StringRef Name, const DIE &Die);
481
482 void finishEntityDefinitions();
483
484 void finishSubprogramDefinitions();
485
486 /// Finish off debug information after all functions have been
487 /// processed.
488 void finalizeModuleInfo();
489
490 /// Emit the debug info section.
491 void emitDebugInfo();
492
493 /// Emit the abbreviation section.
494 void emitAbbreviations();
495
496 /// Emit the string offsets table header.
497 void emitStringOffsetsTableHeader();
498
499 /// Emit a specified accelerator table.
500 template <typename AccelTableT>
501 void emitAccel(AccelTableT &Accel, MCSection *Section, StringRef TableName);
502
503 /// Emit DWARF v5 accelerator table.
504 void emitAccelDebugNames();
505
506 /// Emit visible names into a hashed accelerator table section.
507 void emitAccelNames();
508
509 /// Emit objective C classes and categories into a hashed
510 /// accelerator table section.
511 void emitAccelObjC();
512
513 /// Emit namespace dies into a hashed accelerator table.
514 void emitAccelNamespaces();
515
516 /// Emit type dies into a hashed accelerator table.
517 void emitAccelTypes();
518
519 /// Emit visible names and types into debug pubnames and pubtypes sections.
520 void emitDebugPubSections();
521
522 void emitDebugPubSection(bool GnuStyle, StringRef Name,
523 DwarfCompileUnit *TheU,
524 const StringMap<const DIE *> &Globals);
525
526 /// Emit null-terminated strings into a debug str section.
527 void emitDebugStr();
528
529 /// Emit variable locations into a debug loc section.
530 void emitDebugLoc();
531
532 /// Emit variable locations into a debug loc dwo section.
533 void emitDebugLocDWO();
534
535 void emitDebugLocImpl(MCSection *Sec);
536
537 /// Emit address ranges into a debug aranges section.
538 void emitDebugARanges();
539
540 /// Emit address ranges into a debug ranges section.
541 void emitDebugRanges();
542 void emitDebugRangesDWO();
543 void emitDebugRangesImpl(const DwarfFile &Holder, MCSection *Section);
544
545 /// Emit macros into a debug macinfo section.
546 void emitDebugMacinfo();
547 /// Emit macros into a debug macinfo.dwo section.
548 void emitDebugMacinfoDWO();
549 void emitDebugMacinfoImpl(MCSection *Section);
550 void emitMacro(DIMacro &M);
551 void emitMacroFile(DIMacroFile &F, DwarfCompileUnit &U);
552 void emitMacroFileImpl(DIMacroFile &F, DwarfCompileUnit &U,
553 unsigned StartFile, unsigned EndFile,
554 StringRef (*MacroFormToString)(unsigned Form));
555 void handleMacroNodes(DIMacroNodeArray Nodes, DwarfCompileUnit &U);
556
557 /// DWARF 5 Experimental Split Dwarf Emitters
558
559 /// Initialize common features of skeleton units.
560 void initSkeletonUnit(const DwarfUnit &U, DIE &Die,
561 std::unique_ptr<DwarfCompileUnit> NewU);
562
563 /// Construct the split debug info compile unit for the debug info section.
564 /// In DWARF v5, the skeleton unit DIE may have the following attributes:
565 /// DW_AT_addr_base, DW_AT_comp_dir, DW_AT_dwo_name, DW_AT_high_pc,
566 /// DW_AT_low_pc, DW_AT_ranges, DW_AT_stmt_list, and DW_AT_str_offsets_base.
567 /// Prior to DWARF v5 it may also have DW_AT_GNU_dwo_id. DW_AT_GNU_dwo_name
568 /// is used instead of DW_AT_dwo_name, Dw_AT_GNU_addr_base instead of
569 /// DW_AT_addr_base, and DW_AT_GNU_ranges_base instead of DW_AT_rnglists_base.
570 DwarfCompileUnit &constructSkeletonCU(const DwarfCompileUnit &CU);
571
572 /// Emit the debug info dwo section.
573 void emitDebugInfoDWO();
574
575 /// Emit the debug abbrev dwo section.
576 void emitDebugAbbrevDWO();
577
578 /// Emit the debug line dwo section.
579 void emitDebugLineDWO();
580
581 /// Emit the dwo stringoffsets table header.
582 void emitStringOffsetsTableHeaderDWO();
583
584 /// Emit the debug str dwo section.
585 void emitDebugStrDWO();
586
587 /// Emit DWO addresses.
588 void emitDebugAddr();
589
590 /// Flags to let the linker know we have emitted new style pubnames. Only
591 /// emit it here if we don't have a skeleton CU for split dwarf.
592 void addGnuPubAttributes(DwarfCompileUnit &U, DIE &D) const;
593
594 /// Create new DwarfCompileUnit for the given metadata node with tag
595 /// DW_TAG_compile_unit.
596 DwarfCompileUnit &getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit);
597 void finishUnitAttributes(const DICompileUnit *DIUnit,
598 DwarfCompileUnit &NewCU);
599
600 /// Construct imported_module or imported_declaration DIE.
601 void constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
602 const DIImportedEntity *N);
603
604 /// Register a source line with debug info. Returns the unique
605 /// label that was emitted and which provides correspondence to the
606 /// source line list.
607 void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
608 unsigned Flags);
609
610 /// Populate LexicalScope entries with variables' info.
611 void collectEntityInfo(DwarfCompileUnit &TheCU, const DISubprogram *SP,
612 DenseSet<InlinedEntity> &ProcessedVars);
613
614 /// Build the location list for all DBG_VALUEs in the
615 /// function that describe the same variable. If the resulting
616 /// list has only one entry that is valid for entire variable's
617 /// scope return true.
618 bool buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
619 const DbgValueHistoryMap::Entries &Entries);
620
621 /// Collect variable information from the side table maintained by MF.
622 void collectVariableInfoFromMFTable(DwarfCompileUnit &TheCU,
623 DenseSet<InlinedEntity> &P);
624
625 /// Emit the reference to the section.
626 void emitSectionReference(const DwarfCompileUnit &CU);
627
628 protected:
629 /// Gather pre-function debug information.
630 void beginFunctionImpl(const MachineFunction *MF) override;
631
632 /// Gather and emit post-function debug information.
633 void endFunctionImpl(const MachineFunction *MF) override;
634
635 void skippedNonDebugFunction() override;
636
637 public:
638 //===--------------------------------------------------------------------===//
639 // Main entry points.
640 //
641 DwarfDebug(AsmPrinter *A);
642
643 ~DwarfDebug() override;
644
645 /// Emit all Dwarf sections that should come prior to the
646 /// content.
647 void beginModule(Module *M) override;
648
649 /// Emit all Dwarf sections that should come after the content.
650 void endModule() override;
651
652 /// Emits inital debug location directive.
653 DebugLoc emitInitialLocDirective(const MachineFunction &MF, unsigned CUID);
654
655 /// Process beginning of an instruction.
656 void beginInstruction(const MachineInstr *MI) override;
657
658 /// Perform an MD5 checksum of \p Identifier and return the lower 64 bits.
659 static uint64_t makeTypeSignature(StringRef Identifier);
660
661 /// Add a DIE to the set of types that we're going to pull into
662 /// type units.
663 void addDwarfTypeUnitType(DwarfCompileUnit &CU, StringRef Identifier,
664 DIE &Die, const DICompositeType *CTy);
665
666 class NonTypeUnitContext {
667 DwarfDebug *DD;
668 decltype(DwarfDebug::TypeUnitsUnderConstruction) TypeUnitsUnderConstruction;
669 bool AddrPoolUsed;
670 friend class DwarfDebug;
671 NonTypeUnitContext(DwarfDebug *DD);
672 public:
673 NonTypeUnitContext(NonTypeUnitContext&&) = default;
674 ~NonTypeUnitContext();
675 };
676
677 NonTypeUnitContext enterNonTypeUnitContext();
678
679 /// Add a label so that arange data can be generated for it.
680 void addArangeLabel(SymbolCU SCU) { ArangeLabels.push_back(SCU); }
681
682 /// For symbols that have a size designated (e.g. common symbols),
683 /// this tracks that size.
684 void setSymbolSize(const MCSymbol *Sym, uint64_t Size) override {
685 SymSize[Sym] = Size;
686 }
687
688 /// Returns whether we should emit all DW_AT_[MIPS_]linkage_name.
689 /// If not, we still might emit certain cases.
690 bool useAllLinkageNames() const { return UseAllLinkageNames; }
691
692 /// Returns whether to use DW_OP_GNU_push_tls_address, instead of the
693 /// standard DW_OP_form_tls_address opcode
694 bool useGNUTLSOpcode() const { return UseGNUTLSOpcode; }
695
696 /// Returns whether to use the DWARF2 format for bitfields instyead of the
697 /// DWARF4 format.
698 bool useDWARF2Bitfields() const { return UseDWARF2Bitfields; }
699
700 /// Returns whether to use inline strings.
701 bool useInlineStrings() const { return UseInlineStrings; }
702
703 /// Returns whether ranges section should be emitted.
704 bool useRangesSection() const { return UseRangesSection; }
705
706 /// Returns whether range encodings should be used for single entry range
707 /// lists.
708 bool alwaysUseRanges() const {
709 return MinimizeAddr == MinimizeAddrInV5::Ranges;
710 }
711
712 // Returns whether novel exprloc addrx+offset encodings should be used to
713 // reduce debug_addr size.
714 bool useAddrOffsetExpressions() const {
715 return MinimizeAddr == MinimizeAddrInV5::Expressions;
716 }
717
718 // Returns whether addrx+offset LLVM extension form should be used to reduce
719 // debug_addr size.
720 bool useAddrOffsetForm() const {
721 return MinimizeAddr == MinimizeAddrInV5::Form;
722 }
723
724 /// Returns whether to use sections as labels rather than temp symbols.
725 bool useSectionsAsReferences() const {
726 return UseSectionsAsReferences;
727 }
728
729 /// Returns whether .debug_loc section should be emitted.
730 bool useLocSection() const { return UseLocSection; }
731
732 /// Returns whether to generate DWARF v4 type units.
733 bool generateTypeUnits() const { return GenerateTypeUnits; }
734
735 // Experimental DWARF5 features.
736
737 /// Returns what kind (if any) of accelerator tables to emit.
738 AccelTableKind getAccelTableKind() const { return TheAccelTableKind; }
739
740 bool useAppleExtensionAttributes() const {
741 return HasAppleExtensionAttributes;
742 }
743
744 /// Returns whether or not to change the current debug info for the
745 /// split dwarf proposal support.
746 bool useSplitDwarf() const { return HasSplitDwarf; }
747
748 /// Returns whether to generate a string offsets table with (possibly shared)
749 /// contributions from each CU and type unit. This implies the use of
750 /// DW_FORM_strx* indirect references with DWARF v5 and beyond. Note that
751 /// DW_FORM_GNU_str_index is also an indirect reference, but it is used with
752 /// a pre-DWARF v5 implementation of split DWARF sections, which uses a
753 /// monolithic string offsets table.
754 bool useSegmentedStringOffsetsTable() const {
755 return UseSegmentedStringOffsetsTable;
756 }
757
758 bool emitDebugEntryValues() const {
759 return EmitDebugEntryValues;
760 }
761
762 bool useOpConvert() const {
763 return EnableOpConvert;
764 }
765
766 bool shareAcrossDWOCUs() const;
767
768 /// Returns the Dwarf Version.
769 uint16_t getDwarfVersion() const;
770
771 /// Returns a suitable DWARF form to represent a section offset, i.e.
772 /// * DW_FORM_sec_offset for DWARF version >= 4;
773 /// * DW_FORM_data8 for 64-bit DWARFv3;
774 /// * DW_FORM_data4 for 32-bit DWARFv3 and DWARFv2.
775 dwarf::Form getDwarfSectionOffsetForm() const;
776
777 /// Returns the previous CU that was being updated
778 const DwarfCompileUnit *getPrevCU() const { return PrevCU; }
779 void setPrevCU(const DwarfCompileUnit *PrevCU) { this->PrevCU = PrevCU; }
780
781 /// Returns the entries for the .debug_loc section.
782 const DebugLocStream &getDebugLocs() const { return DebugLocs; }
783
784 /// Emit an entry for the debug loc section. This can be used to
785 /// handle an entry that's going to be emitted into the debug loc section.
786 void emitDebugLocEntry(ByteStreamer &Streamer,
787 const DebugLocStream::Entry &Entry,
788 const DwarfCompileUnit *CU);
789
790 /// Emit the location for a debug loc entry, including the size header.
791 void emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry,
792 const DwarfCompileUnit *CU);
793
794 void addSubprogramNames(const DICompileUnit &CU, const DISubprogram *SP,
795 DIE &Die);
796
797 AddressPool &getAddressPool() { return AddrPool; }
798
799 void addAccelName(const DICompileUnit &CU, StringRef Name, const DIE &Die);
800
801 void addAccelObjC(const DICompileUnit &CU, StringRef Name, const DIE &Die);
802
803 void addAccelNamespace(const DICompileUnit &CU, StringRef Name,
804 const DIE &Die);
805
806 void addAccelType(const DICompileUnit &CU, StringRef Name, const DIE &Die,
807 char Flags);
808
809 const MachineFunction *getCurrentFunction() const { return CurFn; }
810
811 /// A helper function to check whether the DIE for a given Scope is
812 /// going to be null.
813 bool isLexicalScopeDIENull(LexicalScope *Scope);
814
815 /// Find the matching DwarfCompileUnit for the given CU DIE.
816 DwarfCompileUnit *lookupCU(const DIE *Die) { return CUDieMap.lookup(Die); }
817 const DwarfCompileUnit *lookupCU(const DIE *Die) const {
818 return CUDieMap.lookup(Die);
819 }
820
821 unsigned getStringTypeLoc(const DIStringType *ST) const {
822 return StringTypeLocMap.lookup(ST);
823 }
824
825 void addStringTypeLoc(const DIStringType *ST, unsigned Loc) {
826 assert(ST);
827 if (Loc)
828 StringTypeLocMap[ST] = Loc;
829 }
830
831 /// \defgroup DebuggerTuning Predicates to tune DWARF for a given debugger.
832 ///
833 /// Returns whether we are "tuning" for a given debugger.
834 /// @{
835 bool tuneForGDB() const { return DebuggerTuning == DebuggerKind::GDB; }
836 bool tuneForLLDB() const { return DebuggerTuning == DebuggerKind::LLDB; }
837 bool tuneForSCE() const { return DebuggerTuning == DebuggerKind::SCE; }
838 bool tuneForDBX() const { return DebuggerTuning == DebuggerKind::DBX; }
839 /// @}
840
841 const MCSymbol *getSectionLabel(const MCSection *S);
842 void insertSectionLabel(const MCSymbol *S);
843
844 static void emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
845 const DbgValueLoc &Value,
846 DwarfExpression &DwarfExpr);
847
848 /// If the \p File has an MD5 checksum, return it as an MD5Result
849 /// allocated in the MCContext.
850 Optional<MD5::MD5Result> getMD5AsBytes(const DIFile *File) const;
851 };
852
853 } // end namespace llvm
854
855 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFDEBUG_H
856