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 unsigned 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 // DWARF5 Experimental Options
435 bool HasDwarfAccelTables;
438 unsigned DwarfVersion;
440 // Separated Dwarf Variables
441 // In general these will all be for bits that are left in the
442 // original object file, rather than things that are meant
443 // to be in the .dwo sections.
445 // The CUs left in the original object file for separated debug info.
446 SmallVector<CompileUnit *, 1> SkeletonCUs;
448 // Used to uniquely define abbreviations for the skeleton emission.
449 FoldingSet<DIEAbbrev> SkeletonAbbrevSet;
451 // A list of all the unique abbreviations in use.
452 std::vector<DIEAbbrev *> SkeletonAbbrevs;
454 // Holder for the skeleton information.
455 DwarfUnits SkeletonHolder;
459 void addScopeVariable(LexicalScope *LS, DbgVariable *Var);
461 /// \brief Find abstract variable associated with Var.
462 DbgVariable *findAbstractVariable(DIVariable &Var, DebugLoc Loc);
464 /// \brief Find DIE for the given subprogram and attach appropriate
465 /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
466 /// variables in this scope then create and insert DIEs for these
468 DIE *updateSubprogramScopeDIE(CompileUnit *SPCU, const MDNode *SPNode);
470 /// \brief Construct new DW_TAG_lexical_block for this scope and
471 /// attach DW_AT_low_pc/DW_AT_high_pc labels.
472 DIE *constructLexicalScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
474 /// \brief This scope represents inlined body of a function. Construct
475 /// DIE to represent this concrete inlined copy of the function.
476 DIE *constructInlinedScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
478 /// \brief Construct a DIE for this scope.
479 DIE *constructScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
481 /// \brief Emit initial Dwarf sections with a label at the start of each one.
482 void emitSectionLabels();
484 /// \brief Compute the size and offset of a DIE given an incoming Offset.
485 unsigned computeSizeAndOffset(DIE *Die, unsigned Offset);
487 /// \brief Compute the size and offset of all the DIEs.
488 void computeSizeAndOffsets();
490 /// \brief Attach DW_AT_inline attribute with inlined subprogram DIEs.
491 void computeInlinedDIEs();
493 /// \brief Collect info for variables that were optimized out.
494 void collectDeadVariables();
496 /// \brief Finish off debug information after all functions have been
498 void finalizeModuleInfo();
500 /// \brief Emit labels to close any remaining sections that have been left
504 /// \brief Emit a set of abbreviations to the specific section.
505 void emitAbbrevs(const MCSection *, std::vector<DIEAbbrev*> *);
507 /// \brief Emit the debug info section.
508 void emitDebugInfo();
510 /// \brief Emit the abbreviation section.
511 void emitAbbreviations();
513 /// \brief Emit the last address of the section and the end of
515 void emitEndOfLineMatrix(unsigned SectionEnd);
517 /// \brief Emit visible names into a hashed accelerator table section.
518 void emitAccelNames();
520 /// \brief Emit objective C classes and categories into a hashed
521 /// accelerator table section.
522 void emitAccelObjC();
524 /// \brief Emit namespace dies into a hashed accelerator table.
525 void emitAccelNamespaces();
527 /// \brief Emit type dies into a hashed accelerator table.
528 void emitAccelTypes();
530 /// \brief Emit visible names into a debug pubnames section.
531 void emitDebugPubnames();
533 /// \brief Emit visible types into a debug pubtypes section.
534 void emitDebugPubTypes();
536 /// \brief Emit visible names into a debug str section.
539 /// \brief Emit visible names into a debug loc section.
542 /// \brief Emit visible names into a debug aranges section.
543 void emitDebugARanges();
545 /// \brief Emit visible names into a debug ranges section.
546 void emitDebugRanges();
548 /// \brief Emit visible names into a debug macinfo section.
549 void emitDebugMacInfo();
551 /// \brief Emit inline info using custom format.
552 void emitDebugInlineInfo();
554 /// DWARF 5 Experimental Split Dwarf Emitters
556 /// \brief Construct the split debug info compile unit for the debug info
558 CompileUnit *constructSkeletonCU(const MDNode *);
560 /// \brief Emit the local split abbreviations.
561 void emitSkeletonAbbrevs(const MCSection *);
563 /// \brief Emit the debug info dwo section.
564 void emitDebugInfoDWO();
566 /// \brief Emit the debug abbrev dwo section.
567 void emitDebugAbbrevDWO();
569 /// \brief Emit the debug str dwo section.
570 void emitDebugStrDWO();
572 /// \brief Create new CompileUnit for the given metadata node with tag
573 /// DW_TAG_compile_unit.
574 CompileUnit *constructCompileUnit(const MDNode *N);
576 /// \brief Construct subprogram DIE.
577 void constructSubprogramDIE(CompileUnit *TheCU, const MDNode *N);
579 /// \brief Construct imported_module or imported_declaration DIE.
580 void constructImportedEntityDIE(CompileUnit *TheCU, const MDNode *N);
582 /// \brief Construct import_module DIE.
583 void constructImportedEntityDIE(CompileUnit *TheCU, const MDNode *N,
586 /// \brief Construct import_module DIE.
587 void constructImportedEntityDIE(CompileUnit *TheCU,
588 const DIImportedEntity &Module,
591 /// \brief Register a source line with debug info. Returns the unique
592 /// label that was emitted and which provides correspondence to the
593 /// source line list.
594 void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
597 /// \brief Indentify instructions that are marking the beginning of or
598 /// ending of a scope.
599 void identifyScopeMarkers();
601 /// \brief If Var is an current function argument that add it in
602 /// CurrentFnArguments list.
603 bool addCurrentFnArgument(const MachineFunction *MF,
604 DbgVariable *Var, LexicalScope *Scope);
606 /// \brief Populate LexicalScope entries with variables' info.
607 void collectVariableInfo(const MachineFunction *,
608 SmallPtrSet<const MDNode *, 16> &ProcessedVars);
610 /// \brief Collect variable information from the side table maintained
612 void collectVariableInfoFromMMITable(const MachineFunction * MF,
613 SmallPtrSet<const MDNode *, 16> &P);
615 /// \brief Ensure that a label will be emitted before MI.
616 void requestLabelBeforeInsn(const MachineInstr *MI) {
617 LabelsBeforeInsn.insert(std::make_pair(MI, (MCSymbol*)0));
620 /// \brief Return Label preceding the instruction.
621 MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
623 /// \brief Ensure that a label will be emitted after MI.
624 void requestLabelAfterInsn(const MachineInstr *MI) {
625 LabelsAfterInsn.insert(std::make_pair(MI, (MCSymbol*)0));
628 /// \brief Return Label immediately following the instruction.
629 MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
632 //===--------------------------------------------------------------------===//
633 // Main entry points.
635 DwarfDebug(AsmPrinter *A, Module *M);
638 /// \brief Emit all Dwarf sections that should come prior to the
642 /// \brief Emit all Dwarf sections that should come after the content.
645 /// \brief Gather pre-function debug information.
646 void beginFunction(const MachineFunction *MF);
648 /// \brief Gather and emit post-function debug information.
649 void endFunction(const MachineFunction *MF);
651 /// \brief Process beginning of an instruction.
652 void beginInstruction(const MachineInstr *MI);
654 /// \brief Process end of an instruction.
655 void endInstruction(const MachineInstr *MI);
657 /// \brief Add a DIE to the set of types that we're going to pull into
659 void addTypeUnitType(DIE *Die) { TypeUnits.push_back(Die); }
661 /// \brief Look up the source id with the given directory and source file
662 /// names. If none currently exists, create a new id and insert it in the
664 unsigned getOrCreateSourceID(StringRef DirName, StringRef FullName,
667 /// \brief Recursively Emits a debug information entry.
668 void emitDIE(DIE *Die, std::vector<DIEAbbrev *> *Abbrevs);
670 /// \brief Returns whether or not to limit some of our debug
671 /// output to the limitations of darwin gdb.
672 bool useDarwinGDBCompat() { return IsDarwinGDBCompat; }
674 // Experimental DWARF5 features.
676 /// \brief Returns whether or not to emit tables that dwarf consumers can
677 /// use to accelerate lookup.
678 bool useDwarfAccelTables() { return HasDwarfAccelTables; }
680 /// \brief Returns whether or not to change the current debug info for the
681 /// split dwarf proposal support.
682 bool useSplitDwarf() { return HasSplitDwarf; }
684 /// Returns the Dwarf Version.
685 unsigned getDwarfVersion() const { return DwarfVersion; }
687 } // End of namespace llvm