1 //===-- llvm/CodeGen/DwarfDebug.h - Dwarf Debug Framework ------*- C++ -*--===//
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 #ifndef CODEGEN_ASMPRINTER_DWARFDEBUG_H__
15 #define CODEGEN_ASMPRINTER_DWARFDEBUG_H__
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/FoldingSet.h"
20 #include "llvm/ADT/SetVector.h"
21 #include "llvm/ADT/SmallPtrSet.h"
22 #include "llvm/ADT/StringMap.h"
23 #include "llvm/CodeGen/AsmPrinter.h"
24 #include "llvm/CodeGen/LexicalScopes.h"
25 #include "llvm/DebugInfo.h"
26 #include "llvm/MC/MachineLocation.h"
27 #include "llvm/Support/Allocator.h"
28 #include "llvm/Support/DebugLoc.h"
36 class MachineFrameInfo;
37 class MachineModuleInfo;
45 //===----------------------------------------------------------------------===//
46 /// \brief This class is used to record source line correspondence.
48 unsigned Line; // Source line number.
49 unsigned Column; // Source column.
50 unsigned SourceID; // Source ID number.
51 MCSymbol *Label; // Label in code ID number.
53 SrcLineInfo(unsigned L, unsigned C, unsigned S, MCSymbol *label)
54 : Line(L), Column(C), SourceID(S), Label(label) {}
57 unsigned getLine() const { return Line; }
58 unsigned getColumn() const { return Column; }
59 unsigned getSourceID() const { return SourceID; }
60 MCSymbol *getLabel() const { return Label; }
63 /// \brief This struct describes location entries emitted in the .debug_loc
65 class DotDebugLocEntry {
66 // Begin and end symbols for the address range that this location is valid.
67 const MCSymbol *Begin;
70 // Type of entry that this represents.
77 enum EntryType EntryKind;
81 const ConstantFP *CFP;
82 const ConstantInt *CIP;
85 // The location in the machine frame.
88 // The variable to which this location entry corresponds.
89 const MDNode *Variable;
91 // Whether this location has been merged.
95 DotDebugLocEntry() : Begin(0), End(0), Variable(0), Merged(false) {
98 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, MachineLocation &L,
100 : Begin(B), End(E), Loc(L), Variable(V), Merged(false) {
102 EntryKind = E_Location;
104 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, int64_t i)
105 : Begin(B), End(E), Variable(0), Merged(false) {
107 EntryKind = E_Integer;
109 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, const ConstantFP *FPtr)
110 : Begin(B), End(E), Variable(0), Merged(false) {
111 Constants.CFP = FPtr;
112 EntryKind = E_ConstantFP;
114 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E,
115 const ConstantInt *IPtr)
116 : Begin(B), End(E), Variable(0), Merged(false) {
117 Constants.CIP = IPtr;
118 EntryKind = E_ConstantInt;
121 /// \brief Empty entries are also used as a trigger to emit temp label. Such
122 /// labels are referenced is used to find debug_loc offset for a given DIE.
123 bool isEmpty() { return Begin == 0 && End == 0; }
124 bool isMerged() { return Merged; }
125 void Merge(DotDebugLocEntry *Next) {
126 if (!(Begin && Loc == Next->Loc && End == Next->Begin))
131 bool isLocation() const { return EntryKind == E_Location; }
132 bool isInt() const { return EntryKind == E_Integer; }
133 bool isConstantFP() const { return EntryKind == E_ConstantFP; }
134 bool isConstantInt() const { return EntryKind == E_ConstantInt; }
135 int64_t getInt() const { return Constants.Int; }
136 const ConstantFP *getConstantFP() const { return Constants.CFP; }
137 const ConstantInt *getConstantInt() const { return Constants.CIP; }
138 const MDNode *getVariable() const { return Variable; }
139 const MCSymbol *getBeginSym() const { return Begin; }
140 const MCSymbol *getEndSym() const { return End; }
141 MachineLocation getLoc() const { return Loc; }
144 //===----------------------------------------------------------------------===//
145 /// \brief This class is used to track local variable information.
147 DIVariable Var; // Variable Descriptor.
148 DIE *TheDIE; // Variable DIE.
149 unsigned DotDebugLocOffset; // Offset in DotDebugLocEntries.
150 DbgVariable *AbsVar; // Corresponding Abstract variable, if any.
151 const MachineInstr *MInsn; // DBG_VALUE instruction of the variable.
154 // AbsVar may be NULL.
155 DbgVariable(DIVariable V, DbgVariable *AV)
156 : Var(V), TheDIE(0), DotDebugLocOffset(~0U), AbsVar(AV), MInsn(0),
160 DIVariable getVariable() const { return Var; }
161 void setDIE(DIE *D) { TheDIE = D; }
162 DIE *getDIE() const { return TheDIE; }
163 void setDotDebugLocOffset(unsigned O) { DotDebugLocOffset = O; }
164 unsigned getDotDebugLocOffset() const { return DotDebugLocOffset; }
165 StringRef getName() const { return Var.getName(); }
166 DbgVariable *getAbstractVariable() const { return AbsVar; }
167 const MachineInstr *getMInsn() const { return MInsn; }
168 void setMInsn(const MachineInstr *M) { MInsn = M; }
169 int getFrameIndex() const { return FrameIndex; }
170 void setFrameIndex(int FI) { FrameIndex = FI; }
171 // Translate tag to proper Dwarf tag.
172 uint16_t getTag() const {
173 if (Var.getTag() == dwarf::DW_TAG_arg_variable)
174 return dwarf::DW_TAG_formal_parameter;
176 return dwarf::DW_TAG_variable;
178 /// \brief Return true if DbgVariable is artificial.
179 bool isArtificial() const {
180 if (Var.isArtificial())
182 if (getType().isArtificial())
187 bool isObjectPointer() const {
188 if (Var.isObjectPointer())
190 if (getType().isObjectPointer())
195 bool variableHasComplexAddress() const {
196 assert(Var.isVariable() && "Invalid complex DbgVariable!");
197 return Var.hasComplexAddress();
199 bool isBlockByrefVariable() const {
200 assert(Var.isVariable() && "Invalid complex DbgVariable!");
201 return Var.isBlockByrefVariable();
203 unsigned getNumAddrElements() const {
204 assert(Var.isVariable() && "Invalid complex DbgVariable!");
205 return Var.getNumAddrElements();
207 uint64_t getAddrElement(unsigned i) const {
208 return Var.getAddrElement(i);
210 DIType getType() const;
213 /// \brief Collects and handles information specific to a particular
214 /// collection of units.
216 // Target of Dwarf emission, used for sizing of abbreviations.
219 // Used to uniquely define abbreviations.
220 FoldingSet<DIEAbbrev> *AbbreviationsSet;
222 // A list of all the unique abbreviations in use.
223 std::vector<DIEAbbrev *> *Abbreviations;
225 // A pointer to all units in the section.
226 SmallVector<CompileUnit *, 1> CUs;
228 // Collection of strings for this unit and assorted symbols.
229 // A String->Symbol mapping of strings used by indirect
231 typedef StringMap<std::pair<MCSymbol*, unsigned>,
232 BumpPtrAllocator&> StrPool;
234 unsigned NextStringPoolNumber;
235 std::string StringPref;
237 // Collection of addresses for this unit and assorted labels.
238 // A Symbol->unsigned mapping of addresses used by indirect
240 typedef DenseMap<const MCExpr *, unsigned> AddrPool;
241 AddrPool AddressPool;
242 unsigned NextAddrPoolNumber;
245 DwarfUnits(AsmPrinter *AP, FoldingSet<DIEAbbrev> *AS,
246 std::vector<DIEAbbrev *> *A, const char *Pref,
247 BumpPtrAllocator &DA)
248 : Asm(AP), AbbreviationsSet(AS), Abbreviations(A), StringPool(DA),
249 NextStringPoolNumber(0), StringPref(Pref), AddressPool(),
250 NextAddrPoolNumber(0) {}
252 /// \brief Compute the size and offset of a DIE given an incoming Offset.
253 unsigned computeSizeAndOffset(DIE *Die, unsigned Offset);
255 /// \brief Compute the size and offset of all the DIEs.
256 void computeSizeAndOffsets();
258 /// \brief Define a unique number for the abbreviation.
259 void assignAbbrevNumber(DIEAbbrev &Abbrev);
261 /// \brief Add a unit to the list of CUs.
262 void addUnit(CompileUnit *CU) { CUs.push_back(CU); }
264 /// \brief Emit all of the units to the section listed with the given
265 /// abbreviation section.
266 void emitUnits(DwarfDebug *DD, const MCSection *USection,
267 const MCSection *ASection, const MCSymbol *ASectionSym);
269 /// \brief Emit all of the strings to the section given.
270 void emitStrings(const MCSection *StrSection, const MCSection *OffsetSection,
271 const MCSymbol *StrSecSym);
273 /// \brief Emit all of the addresses to the section given.
274 void emitAddresses(const MCSection *AddrSection);
276 /// \brief Returns the entry into the start of the pool.
277 MCSymbol *getStringPoolSym();
279 /// \brief Returns an entry into the string pool with the given
281 MCSymbol *getStringPoolEntry(StringRef Str);
283 /// \brief Returns the index into the string pool with the given
285 unsigned getStringPoolIndex(StringRef Str);
287 /// \brief Returns the string pool.
288 StrPool *getStringPool() { return &StringPool; }
290 /// \brief Returns the index into the address pool with the given
292 unsigned getAddrPoolIndex(const MCExpr *Sym);
293 unsigned getAddrPoolIndex(const MCSymbol *Sym);
295 /// \brief Returns the address pool.
296 AddrPool *getAddrPool() { return &AddressPool; }
298 /// \brief for a given compile unit DIE, returns offset from beginning of
300 unsigned getCUOffset(DIE *Die);
303 /// \brief Collects and handles dwarf debug information.
305 // Target of Dwarf emission.
308 // Collected machine module information.
309 MachineModuleInfo *MMI;
311 // All DIEValues are allocated through this allocator.
312 BumpPtrAllocator DIEValueAllocator;
314 // Handle to the a compile unit used for the inline extension handling.
315 CompileUnit *FirstCU;
317 // Maps MDNode with its corresponding CompileUnit.
318 DenseMap <const MDNode *, CompileUnit *> CUMap;
320 // Maps subprogram MDNode with its corresponding CompileUnit.
321 DenseMap <const MDNode *, CompileUnit *> SPMap;
323 // Used to uniquely define abbreviations.
324 FoldingSet<DIEAbbrev> AbbreviationsSet;
326 // A list of all the unique abbreviations in use.
327 std::vector<DIEAbbrev *> Abbreviations;
329 // Stores the current file ID for a given compile unit.
330 DenseMap <unsigned, unsigned> FileIDCUMap;
331 // Source id map, i.e. CUID, source filename and directory,
332 // separated by a zero byte, mapped to a unique id.
333 StringMap<unsigned, BumpPtrAllocator&> SourceIdMap;
335 // Provides a unique id per text section.
336 SetVector<const MCSection*> SectionMap;
338 // List of arguments for current function.
339 SmallVector<DbgVariable *, 8> CurrentFnArguments;
341 LexicalScopes LScopes;
343 // Collection of abstract subprogram DIEs.
344 DenseMap<const MDNode *, DIE *> AbstractSPDies;
346 // Collection of dbg variables of a scope.
347 typedef DenseMap<LexicalScope *,
348 SmallVector<DbgVariable *, 8> > ScopeVariablesMap;
349 ScopeVariablesMap ScopeVariables;
351 // Collection of abstract variables.
352 DenseMap<const MDNode *, DbgVariable *> AbstractVariables;
354 // Collection of DotDebugLocEntry.
355 SmallVector<DotDebugLocEntry, 4> DotDebugLocEntries;
357 // Collection of subprogram DIEs that are marked (at the end of the module)
359 SmallPtrSet<DIE *, 4> InlinedSubprogramDIEs;
361 // Keep track of inlined functions and their location. This
362 // information is used to populate the debug_inlined section.
363 typedef std::pair<const MCSymbol *, DIE *> InlineInfoLabels;
364 typedef DenseMap<const MDNode *,
365 SmallVector<InlineInfoLabels, 4> > InlineInfoMap;
366 InlineInfoMap InlineInfo;
367 SmallVector<const MDNode *, 4> InlinedSPNodes;
369 // This is a collection of subprogram MDNodes that are processed to
371 SmallPtrSet<const MDNode *, 16> ProcessedSPNodes;
373 // Maps instruction with label emitted before instruction.
374 DenseMap<const MachineInstr *, MCSymbol *> LabelsBeforeInsn;
376 // Maps instruction with label emitted after instruction.
377 DenseMap<const MachineInstr *, MCSymbol *> LabelsAfterInsn;
379 // Every user variable mentioned by a DBG_VALUE instruction in order of
381 SmallVector<const MDNode*, 8> UserVariables;
383 // For each user variable, keep a list of DBG_VALUE instructions in order.
384 // The list can also contain normal instructions that clobber the previous
386 typedef DenseMap<const MDNode*, SmallVector<const MachineInstr*, 4> >
388 DbgValueHistoryMap DbgValues;
390 SmallVector<const MCSymbol *, 8> DebugRangeSymbols;
392 // Previous instruction's location information. This is used to determine
393 // label location to indicate scope boundries in dwarf debug info.
394 DebugLoc PrevInstLoc;
397 // This location indicates end of function prologue and beginning of function
399 DebugLoc PrologEndLoc;
401 // Section Symbols: these are assembler temporary labels that are emitted at
402 // the beginning of each supported dwarf section. These are used to form
403 // section offsets and are created by EmitSectionLabels.
404 MCSymbol *DwarfInfoSectionSym, *DwarfAbbrevSectionSym;
405 MCSymbol *DwarfStrSectionSym, *TextSectionSym, *DwarfDebugRangeSectionSym;
406 MCSymbol *DwarfDebugLocSectionSym, *DwarfLineSectionSym, *DwarfAddrSectionSym;
407 MCSymbol *FunctionBeginSym, *FunctionEndSym;
408 MCSymbol *DwarfAbbrevDWOSectionSym, *DwarfStrDWOSectionSym;
410 // As an optimization, there is no need to emit an entry in the directory
411 // table for the same directory as DW_AT_comp_dir.
412 StringRef CompilationDir;
414 // Counter for assigning globally unique IDs for CUs.
415 unsigned GlobalCUIndexCount;
417 // Holder for the file specific debug information.
418 DwarfUnits InfoHolder;
420 // Holders for the various debug information flags that we might need to
421 // have exposed. See accessor functions below for description.
423 // Whether or not we're emitting info for older versions of gdb on darwin.
424 bool IsDarwinGDBCompat;
426 // Holder for imported entities.
427 typedef SmallVector<std::pair<const MDNode *, const MDNode *>, 32>
429 ImportedEntityMap ScopesWithImportedEntities;
431 // Holder for types that are going to be extracted out into a type unit.
432 std::vector<DIE *> TypeUnits;
434 // Whether to emit the pubnames/pubtypes sections.
435 bool HasDwarfPubSections;
437 // Version of dwarf we're emitting.
438 unsigned DwarfVersion;
440 // DWARF5 Experimental Options
441 bool HasDwarfAccelTables;
444 // Separated Dwarf Variables
445 // In general these will all be for bits that are left in the
446 // original object file, rather than things that are meant
447 // to be in the .dwo sections.
449 // The CUs left in the original object file for separated debug info.
450 SmallVector<CompileUnit *, 1> SkeletonCUs;
452 // Used to uniquely define abbreviations for the skeleton emission.
453 FoldingSet<DIEAbbrev> SkeletonAbbrevSet;
455 // A list of all the unique abbreviations in use.
456 std::vector<DIEAbbrev *> SkeletonAbbrevs;
458 // Holder for the skeleton information.
459 DwarfUnits SkeletonHolder;
463 void addScopeVariable(LexicalScope *LS, DbgVariable *Var);
465 /// \brief Find abstract variable associated with Var.
466 DbgVariable *findAbstractVariable(DIVariable &Var, DebugLoc Loc);
468 /// \brief Find DIE for the given subprogram and attach appropriate
469 /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
470 /// variables in this scope then create and insert DIEs for these
472 DIE *updateSubprogramScopeDIE(CompileUnit *SPCU, const MDNode *SPNode);
474 /// \brief Construct new DW_TAG_lexical_block for this scope and
475 /// attach DW_AT_low_pc/DW_AT_high_pc labels.
476 DIE *constructLexicalScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
478 /// \brief This scope represents inlined body of a function. Construct
479 /// DIE to represent this concrete inlined copy of the function.
480 DIE *constructInlinedScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
482 /// \brief Construct a DIE for this scope.
483 DIE *constructScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
485 /// \brief Emit initial Dwarf sections with a label at the start of each one.
486 void emitSectionLabels();
488 /// \brief Compute the size and offset of a DIE given an incoming Offset.
489 unsigned computeSizeAndOffset(DIE *Die, unsigned Offset);
491 /// \brief Compute the size and offset of all the DIEs.
492 void computeSizeAndOffsets();
494 /// \brief Attach DW_AT_inline attribute with inlined subprogram DIEs.
495 void computeInlinedDIEs();
497 /// \brief Collect info for variables that were optimized out.
498 void collectDeadVariables();
500 /// \brief Finish off debug information after all functions have been
502 void finalizeModuleInfo();
504 /// \brief Emit labels to close any remaining sections that have been left
508 /// \brief Emit a set of abbreviations to the specific section.
509 void emitAbbrevs(const MCSection *, std::vector<DIEAbbrev*> *);
511 /// \brief Emit the debug info section.
512 void emitDebugInfo();
514 /// \brief Emit the abbreviation section.
515 void emitAbbreviations();
517 /// \brief Emit the last address of the section and the end of
519 void emitEndOfLineMatrix(unsigned SectionEnd);
521 /// \brief Emit visible names into a hashed accelerator table section.
522 void emitAccelNames();
524 /// \brief Emit objective C classes and categories into a hashed
525 /// accelerator table section.
526 void emitAccelObjC();
528 /// \brief Emit namespace dies into a hashed accelerator table.
529 void emitAccelNamespaces();
531 /// \brief Emit type dies into a hashed accelerator table.
532 void emitAccelTypes();
534 /// \brief Emit visible names into a debug pubnames section.
535 void emitDebugPubnames();
537 /// \brief Emit visible types into a debug pubtypes section.
538 void emitDebugPubTypes();
540 /// \brief Emit visible names into a debug str section.
543 /// \brief Emit visible names into a debug loc section.
546 /// \brief Emit visible names into a debug aranges section.
547 void emitDebugARanges();
549 /// \brief Emit visible names into a debug ranges section.
550 void emitDebugRanges();
552 /// \brief Emit visible names into a debug macinfo section.
553 void emitDebugMacInfo();
555 /// \brief Emit inline info using custom format.
556 void emitDebugInlineInfo();
558 /// DWARF 5 Experimental Split Dwarf Emitters
560 /// \brief Construct the split debug info compile unit for the debug info
562 CompileUnit *constructSkeletonCU(const CompileUnit *CU);
564 /// \brief Emit the local split abbreviations.
565 void emitSkeletonAbbrevs(const MCSection *);
567 /// \brief Emit the debug info dwo section.
568 void emitDebugInfoDWO();
570 /// \brief Emit the debug abbrev dwo section.
571 void emitDebugAbbrevDWO();
573 /// \brief Emit the debug str dwo section.
574 void emitDebugStrDWO();
576 /// \brief Create new CompileUnit for the given metadata node with tag
577 /// DW_TAG_compile_unit.
578 CompileUnit *constructCompileUnit(const MDNode *N);
580 /// \brief Construct subprogram DIE.
581 void constructSubprogramDIE(CompileUnit *TheCU, const MDNode *N);
583 /// \brief Construct imported_module or imported_declaration DIE.
584 void constructImportedEntityDIE(CompileUnit *TheCU, const MDNode *N);
586 /// \brief Construct import_module DIE.
587 void constructImportedEntityDIE(CompileUnit *TheCU, const MDNode *N,
590 /// \brief Construct import_module DIE.
591 void constructImportedEntityDIE(CompileUnit *TheCU,
592 const DIImportedEntity &Module,
595 /// \brief Register a source line with debug info. Returns the unique
596 /// label that was emitted and which provides correspondence to the
597 /// source line list.
598 void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
601 /// \brief Indentify instructions that are marking the beginning of or
602 /// ending of a scope.
603 void identifyScopeMarkers();
605 /// \brief If Var is an current function argument that add it in
606 /// CurrentFnArguments list.
607 bool addCurrentFnArgument(const MachineFunction *MF,
608 DbgVariable *Var, LexicalScope *Scope);
610 /// \brief Populate LexicalScope entries with variables' info.
611 void collectVariableInfo(const MachineFunction *,
612 SmallPtrSet<const MDNode *, 16> &ProcessedVars);
614 /// \brief Collect variable information from the side table maintained
616 void collectVariableInfoFromMMITable(const MachineFunction * MF,
617 SmallPtrSet<const MDNode *, 16> &P);
619 /// \brief Ensure that a label will be emitted before MI.
620 void requestLabelBeforeInsn(const MachineInstr *MI) {
621 LabelsBeforeInsn.insert(std::make_pair(MI, (MCSymbol*)0));
624 /// \brief Return Label preceding the instruction.
625 MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
627 /// \brief Ensure that a label will be emitted after MI.
628 void requestLabelAfterInsn(const MachineInstr *MI) {
629 LabelsAfterInsn.insert(std::make_pair(MI, (MCSymbol*)0));
632 /// \brief Return Label immediately following the instruction.
633 MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
636 //===--------------------------------------------------------------------===//
637 // Main entry points.
639 DwarfDebug(AsmPrinter *A, Module *M);
642 /// \brief Emit all Dwarf sections that should come prior to the
646 /// \brief Emit all Dwarf sections that should come after the content.
649 /// \brief Gather pre-function debug information.
650 void beginFunction(const MachineFunction *MF);
652 /// \brief Gather and emit post-function debug information.
653 void endFunction(const MachineFunction *MF);
655 /// \brief Process beginning of an instruction.
656 void beginInstruction(const MachineInstr *MI);
658 /// \brief Process end of an instruction.
659 void endInstruction(const MachineInstr *MI);
661 /// \brief Add a DIE to the set of types that we're going to pull into
663 void addTypeUnitType(DIE *Die) { TypeUnits.push_back(Die); }
665 /// \brief Look up the source id with the given directory and source file
666 /// names. If none currently exists, create a new id and insert it in the
668 unsigned getOrCreateSourceID(StringRef DirName, StringRef FullName,
671 /// \brief Recursively Emits a debug information entry.
672 void emitDIE(DIE *Die, std::vector<DIEAbbrev *> *Abbrevs);
674 /// \brief Returns whether or not to limit some of our debug
675 /// output to the limitations of darwin gdb.
676 bool useDarwinGDBCompat() { return IsDarwinGDBCompat; }
678 // Experimental DWARF5 features.
680 /// \brief Returns whether or not to emit tables that dwarf consumers can
681 /// use to accelerate lookup.
682 bool useDwarfAccelTables() { return HasDwarfAccelTables; }
684 /// \brief Returns whether or not to change the current debug info for the
685 /// split dwarf proposal support.
686 bool useSplitDwarf() { return HasSplitDwarf; }
688 /// Returns the Dwarf Version.
689 unsigned getDwarfVersion() const { return DwarfVersion; }
691 } // End of namespace llvm