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;
46 //===----------------------------------------------------------------------===//
47 /// \brief This class is used to record source line correspondence.
49 unsigned Line; // Source line number.
50 unsigned Column; // Source column.
51 unsigned SourceID; // Source ID number.
52 MCSymbol *Label; // Label in code ID number.
54 SrcLineInfo(unsigned L, unsigned C, unsigned S, MCSymbol *label)
55 : Line(L), Column(C), SourceID(S), Label(label) {}
58 unsigned getLine() const { return Line; }
59 unsigned getColumn() const { return Column; }
60 unsigned getSourceID() const { return SourceID; }
61 MCSymbol *getLabel() const { return Label; }
64 /// \brief This struct describes location entries emitted in the .debug_loc
66 typedef struct DotDebugLocEntry {
67 const MCSymbol *Begin;
70 const MDNode *Variable;
79 enum EntryType EntryKind;
83 const ConstantFP *CFP;
84 const ConstantInt *CIP;
87 : Begin(0), End(0), Variable(0), Merged(false),
88 Constant(false) { Constants.Int = 0;}
89 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, MachineLocation &L,
91 : Begin(B), End(E), Loc(L), Variable(V), Merged(false),
92 Constant(false) { Constants.Int = 0; EntryKind = E_Location; }
93 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, int64_t i)
94 : Begin(B), End(E), Variable(0), Merged(false),
95 Constant(true) { Constants.Int = i; EntryKind = E_Integer; }
96 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, const ConstantFP *FPtr)
97 : Begin(B), End(E), Variable(0), Merged(false),
98 Constant(true) { Constants.CFP = FPtr; EntryKind = E_ConstantFP; }
99 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E,
100 const ConstantInt *IPtr)
101 : Begin(B), End(E), Variable(0), Merged(false),
102 Constant(true) { Constants.CIP = IPtr; EntryKind = E_ConstantInt; }
104 /// \brief Empty entries are also used as a trigger to emit temp label. Such
105 /// labels are referenced is used to find debug_loc offset for a given DIE.
106 bool isEmpty() { return Begin == 0 && End == 0; }
107 bool isMerged() { return Merged; }
108 void Merge(DotDebugLocEntry *Next) {
109 if (!(Begin && Loc == Next->Loc && End == Next->Begin))
114 bool isLocation() const { return EntryKind == E_Location; }
115 bool isInt() const { return EntryKind == E_Integer; }
116 bool isConstantFP() const { return EntryKind == E_ConstantFP; }
117 bool isConstantInt() const { return EntryKind == E_ConstantInt; }
118 int64_t getInt() { return Constants.Int; }
119 const ConstantFP *getConstantFP() { return Constants.CFP; }
120 const ConstantInt *getConstantInt() { return Constants.CIP; }
123 //===----------------------------------------------------------------------===//
124 /// \brief This class is used to track local variable information.
126 DIVariable Var; // Variable Descriptor.
127 DIE *TheDIE; // Variable DIE.
128 unsigned DotDebugLocOffset; // Offset in DotDebugLocEntries.
129 DbgVariable *AbsVar; // Corresponding Abstract variable, if any.
130 const MachineInstr *MInsn; // DBG_VALUE instruction of the variable.
133 // AbsVar may be NULL.
134 DbgVariable(DIVariable V, DbgVariable *AV)
135 : Var(V), TheDIE(0), DotDebugLocOffset(~0U), AbsVar(AV), MInsn(0),
139 DIVariable getVariable() const { return Var; }
140 void setDIE(DIE *D) { TheDIE = D; }
141 DIE *getDIE() const { return TheDIE; }
142 void setDotDebugLocOffset(unsigned O) { DotDebugLocOffset = O; }
143 unsigned getDotDebugLocOffset() const { return DotDebugLocOffset; }
144 StringRef getName() const { return Var.getName(); }
145 DbgVariable *getAbstractVariable() const { return AbsVar; }
146 const MachineInstr *getMInsn() const { return MInsn; }
147 void setMInsn(const MachineInstr *M) { MInsn = M; }
148 int getFrameIndex() const { return FrameIndex; }
149 void setFrameIndex(int FI) { FrameIndex = FI; }
150 // Translate tag to proper Dwarf tag.
151 unsigned getTag() const {
152 if (Var.getTag() == dwarf::DW_TAG_arg_variable)
153 return dwarf::DW_TAG_formal_parameter;
155 return dwarf::DW_TAG_variable;
157 /// \brief Return true if DbgVariable is artificial.
158 bool isArtificial() const {
159 if (Var.isArtificial())
161 if (getType().isArtificial())
166 bool isObjectPointer() const {
167 if (Var.isObjectPointer())
169 if (getType().isObjectPointer())
174 bool variableHasComplexAddress() const {
175 assert(Var.Verify() && "Invalid complex DbgVariable!");
176 return Var.hasComplexAddress();
178 bool isBlockByrefVariable() const {
179 assert(Var.Verify() && "Invalid complex DbgVariable!");
180 return Var.isBlockByrefVariable();
182 unsigned getNumAddrElements() const {
183 assert(Var.Verify() && "Invalid complex DbgVariable!");
184 return Var.getNumAddrElements();
186 uint64_t getAddrElement(unsigned i) const {
187 return Var.getAddrElement(i);
189 DIType getType() const;
193 // A String->Symbol mapping of strings used by indirect
195 typedef StringMap<std::pair<MCSymbol*, unsigned>,
196 BumpPtrAllocator&> StrPool;
198 // A Symbol->unsigned mapping of addresses used by indirect
200 typedef DenseMap<const MCExpr *, unsigned> AddrPool;
202 /// \brief Collects and handles information specific to a particular
203 /// collection of units.
205 // Target of Dwarf emission, used for sizing of abbreviations.
208 // Used to uniquely define abbreviations.
209 FoldingSet<DIEAbbrev> *AbbreviationsSet;
211 // A list of all the unique abbreviations in use.
212 std::vector<DIEAbbrev *> *Abbreviations;
214 // A pointer to all units in the section.
215 SmallVector<CompileUnit *, 1> CUs;
217 // Collection of strings for this unit and assorted symbols.
219 unsigned NextStringPoolNumber;
220 std::string StringPref;
222 // Collection of addresses for this unit and assorted labels.
223 AddrPool AddressPool;
224 unsigned NextAddrPoolNumber;
227 DwarfUnits(AsmPrinter *AP, FoldingSet<DIEAbbrev> *AS,
228 std::vector<DIEAbbrev *> *A, const char *Pref,
229 BumpPtrAllocator &DA) :
230 Asm(AP), AbbreviationsSet(AS), Abbreviations(A),
231 StringPool(DA), NextStringPoolNumber(0), StringPref(Pref),
232 AddressPool(), NextAddrPoolNumber(0) {}
234 /// \brief Compute the size and offset of a DIE given an incoming Offset.
235 unsigned computeSizeAndOffset(DIE *Die, unsigned Offset);
237 /// \brief Compute the size and offset of all the DIEs.
238 void computeSizeAndOffsets();
240 /// \brief Define a unique number for the abbreviation.
241 void assignAbbrevNumber(DIEAbbrev &Abbrev);
243 /// \brief Add a unit to the list of CUs.
244 void addUnit(CompileUnit *CU) { CUs.push_back(CU); }
246 /// \brief Emit all of the units to the section listed with the given
247 /// abbreviation section.
248 void emitUnits(DwarfDebug *, const MCSection *, const MCSection *,
251 /// \brief Emit all of the strings to the section given.
252 void emitStrings(const MCSection *, const MCSection *, const MCSymbol *);
254 /// \brief Emit all of the addresses to the section given.
255 void emitAddresses(const MCSection *);
257 /// \brief Returns the entry into the start of the pool.
258 MCSymbol *getStringPoolSym();
260 /// \brief Returns an entry into the string pool with the given
262 MCSymbol *getStringPoolEntry(StringRef Str);
264 /// \brief Returns the index into the string pool with the given
266 unsigned getStringPoolIndex(StringRef Str);
268 /// \brief Returns the string pool.
269 StrPool *getStringPool() { return &StringPool; }
271 /// \brief Returns the index into the address pool with the given
273 unsigned getAddrPoolIndex(const MCExpr *);
274 unsigned getAddrPoolIndex(const MCSymbol *);
276 /// \brief Returns the address pool.
277 AddrPool *getAddrPool() { return &AddressPool; }
279 /// \brief for a given compile unit DIE, returns offset from beginning of
281 unsigned getCUOffset(DIE *Die);
284 /// \brief Collects and handles dwarf debug information.
286 // Target of Dwarf emission.
289 // Collected machine module information.
290 MachineModuleInfo *MMI;
292 // All DIEValues are allocated through this allocator.
293 BumpPtrAllocator DIEValueAllocator;
295 //===--------------------------------------------------------------------===//
296 // Attribute used to construct specific Dwarf sections.
299 CompileUnit *FirstCU;
301 // Maps MDNode with its corresponding CompileUnit.
302 DenseMap <const MDNode *, CompileUnit *> CUMap;
304 // Maps subprogram MDNode with its corresponding CompileUnit.
305 DenseMap <const MDNode *, CompileUnit *> SPMap;
307 // Used to uniquely define abbreviations.
308 FoldingSet<DIEAbbrev> AbbreviationsSet;
310 // A list of all the unique abbreviations in use.
311 std::vector<DIEAbbrev *> Abbreviations;
313 // Stores the current file ID for a given compile unit.
314 DenseMap <unsigned, unsigned> FileIDCUMap;
315 // Source id map, i.e. CUID, source filename and directory,
316 // separated by a zero byte, mapped to a unique id.
317 StringMap<unsigned, BumpPtrAllocator&> SourceIdMap;
319 // Provides a unique id per text section.
320 SetVector<const MCSection*> SectionMap;
322 // List of Arguments (DbgValues) for current function.
323 SmallVector<DbgVariable *, 8> CurrentFnArguments;
325 LexicalScopes LScopes;
327 // Collection of abstract subprogram DIEs.
328 DenseMap<const MDNode *, DIE *> AbstractSPDies;
330 // Collection of dbg variables of a scope.
331 DenseMap<LexicalScope *, SmallVector<DbgVariable *, 8> > ScopeVariables;
333 // Collection of abstract variables.
334 DenseMap<const MDNode *, DbgVariable *> AbstractVariables;
336 // Collection of DotDebugLocEntry.
337 SmallVector<DotDebugLocEntry, 4> DotDebugLocEntries;
339 // Collection of subprogram DIEs that are marked (at the end of the module)
341 SmallPtrSet<DIE *, 4> InlinedSubprogramDIEs;
343 // Keep track of inlined functions and their location. This
344 // information is used to populate the debug_inlined section.
345 typedef std::pair<const MCSymbol *, DIE *> InlineInfoLabels;
346 DenseMap<const MDNode *, SmallVector<InlineInfoLabels, 4> > InlineInfo;
347 SmallVector<const MDNode *, 4> InlinedSPNodes;
349 // This is a collection of subprogram MDNodes that are processed to
351 SmallPtrSet<const MDNode *, 16> ProcessedSPNodes;
353 // Maps instruction with label emitted before instruction.
354 DenseMap<const MachineInstr *, MCSymbol *> LabelsBeforeInsn;
356 // Maps instruction with label emitted after instruction.
357 DenseMap<const MachineInstr *, MCSymbol *> LabelsAfterInsn;
359 // Every user variable mentioned by a DBG_VALUE instruction in order of
361 SmallVector<const MDNode*, 8> UserVariables;
363 // For each user variable, keep a list of DBG_VALUE instructions in order.
364 // The list can also contain normal instructions that clobber the previous
366 typedef DenseMap<const MDNode*, SmallVector<const MachineInstr*, 4> >
368 DbgValueHistoryMap DbgValues;
370 SmallVector<const MCSymbol *, 8> DebugRangeSymbols;
372 // Previous instruction's location information. This is used to determine
373 // label location to indicate scope boundries in dwarf debug info.
374 DebugLoc PrevInstLoc;
377 // This location indicates end of function prologue and beginning of function
379 DebugLoc PrologEndLoc;
381 // Section Symbols: these are assembler temporary labels that are emitted at
382 // the beginning of each supported dwarf section. These are used to form
383 // section offsets and are created by EmitSectionLabels.
384 MCSymbol *DwarfInfoSectionSym, *DwarfAbbrevSectionSym;
385 MCSymbol *DwarfStrSectionSym, *TextSectionSym, *DwarfDebugRangeSectionSym;
386 MCSymbol *DwarfDebugLocSectionSym, *DwarfLineSectionSym, *DwarfAddrSectionSym;
387 MCSymbol *FunctionBeginSym, *FunctionEndSym;
388 MCSymbol *DwarfAbbrevDWOSectionSym, *DwarfStrDWOSectionSym;
390 // As an optimization, there is no need to emit an entry in the directory
391 // table for the same directory as DW_at_comp_dir.
392 StringRef CompilationDir;
394 // Counter for assigning globally unique IDs for CUs.
395 unsigned GlobalCUIndexCount;
397 // Holder for the file specific debug information.
398 DwarfUnits InfoHolder;
400 // Holders for the various debug information flags that we might need to
401 // have exposed. See accessor functions below for description.
403 // Whether or not we're emitting info for older versions of gdb on darwin.
404 bool IsDarwinGDBCompat;
406 // DWARF5 Experimental Options
407 bool HasDwarfAccelTables;
410 // Separated Dwarf Variables
411 // In general these will all be for bits that are left in the
412 // original object file, rather than things that are meant
413 // to be in the .dwo sections.
415 // The CUs left in the original object file for separated debug info.
416 SmallVector<CompileUnit *, 1> SkeletonCUs;
418 // Used to uniquely define abbreviations for the skeleton emission.
419 FoldingSet<DIEAbbrev> SkeletonAbbrevSet;
421 // A list of all the unique abbreviations in use.
422 std::vector<DIEAbbrev *> SkeletonAbbrevs;
424 // Holder for the skeleton information.
425 DwarfUnits SkeletonHolder;
427 typedef SmallVector<std::pair<const MDNode *, const MDNode *>, 32>
429 ImportedEntityMap ScopesWithImportedEntities;
433 void addScopeVariable(LexicalScope *LS, DbgVariable *Var);
435 /// \brief Find abstract variable associated with Var.
436 DbgVariable *findAbstractVariable(DIVariable &Var, DebugLoc Loc);
438 /// \brief Find DIE for the given subprogram and attach appropriate
439 /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
440 /// variables in this scope then create and insert DIEs for these
442 DIE *updateSubprogramScopeDIE(CompileUnit *SPCU, const MDNode *SPNode);
444 /// \brief Construct new DW_TAG_lexical_block for this scope and
445 /// attach DW_AT_low_pc/DW_AT_high_pc labels.
446 DIE *constructLexicalScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
448 /// \brief This scope represents inlined body of a function. Construct
449 /// DIE to represent this concrete inlined copy of the function.
450 DIE *constructInlinedScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
452 /// \brief Construct a DIE for this scope.
453 DIE *constructScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
455 /// \brief Emit initial Dwarf sections with a label at the start of each one.
456 void emitSectionLabels();
458 /// \brief Compute the size and offset of a DIE given an incoming Offset.
459 unsigned computeSizeAndOffset(DIE *Die, unsigned Offset);
461 /// \brief Compute the size and offset of all the DIEs.
462 void computeSizeAndOffsets();
464 /// \brief Attach DW_AT_inline attribute with inlined subprogram DIEs.
465 void computeInlinedDIEs();
467 /// \brief Collect info for variables that were optimized out.
468 void collectDeadVariables();
470 /// \brief Finish off debug information after all functions have been
472 void finalizeModuleInfo();
474 /// \brief Emit labels to close any remaining sections that have been left
478 /// \brief Emit a set of abbreviations to the specific section.
479 void emitAbbrevs(const MCSection *, std::vector<DIEAbbrev*> *);
481 /// \brief Emit the debug info section.
482 void emitDebugInfo();
484 /// \brief Emit the abbreviation section.
485 void emitAbbreviations();
487 /// \brief Emit the last address of the section and the end of
489 void emitEndOfLineMatrix(unsigned SectionEnd);
491 /// \brief Emit visible names into a hashed accelerator table section.
492 void emitAccelNames();
494 /// \brief Emit objective C classes and categories into a hashed
495 /// accelerator table section.
496 void emitAccelObjC();
498 /// \brief Emit namespace dies into a hashed accelerator table.
499 void emitAccelNamespaces();
501 /// \brief Emit type dies into a hashed accelerator table.
502 void emitAccelTypes();
504 /// \brief Emit visible names into a debug pubnames section.
505 void emitDebugPubnames();
507 /// \brief Emit visible types into a debug pubtypes section.
508 void emitDebugPubTypes();
510 /// \brief Emit visible names into a debug str section.
513 /// \brief Emit visible names into a debug loc section.
516 /// \brief Emit visible names into a debug aranges section.
517 void emitDebugARanges();
519 /// \brief Emit visible names into a debug ranges section.
520 void emitDebugRanges();
522 /// \brief Emit visible names into a debug macinfo section.
523 void emitDebugMacInfo();
525 /// \brief Emit inline info using custom format.
526 void emitDebugInlineInfo();
528 /// DWARF 5 Experimental Split Dwarf Emitters
530 /// \brief Construct the split debug info compile unit for the debug info
532 CompileUnit *constructSkeletonCU(const MDNode *);
534 /// \brief Emit the local split abbreviations.
535 void emitSkeletonAbbrevs(const MCSection *);
537 /// \brief Emit the debug info dwo section.
538 void emitDebugInfoDWO();
540 /// \brief Emit the debug abbrev dwo section.
541 void emitDebugAbbrevDWO();
543 /// \brief Emit the debug str dwo section.
544 void emitDebugStrDWO();
546 /// \brief Create new CompileUnit for the given metadata node with tag
547 /// DW_TAG_compile_unit.
548 CompileUnit *constructCompileUnit(const MDNode *N);
550 /// \brief Construct subprogram DIE.
551 void constructSubprogramDIE(CompileUnit *TheCU, const MDNode *N);
553 /// \brief Construct imported_module or imported_declaration DIE.
554 void constructImportedEntityDIE(CompileUnit *TheCU, const MDNode *N);
556 /// \brief Construct import_module DIE.
557 void constructImportedEntityDIE(CompileUnit *TheCU, const MDNode *N,
560 /// \brief Construct import_module DIE.
561 void constructImportedEntityDIE(CompileUnit *TheCU,
562 const DIImportedEntity &Module,
565 /// \brief Register a source line with debug info. Returns the unique
566 /// label that was emitted and which provides correspondence to the
567 /// source line list.
568 void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
571 /// \brief Indentify instructions that are marking the beginning of or
572 /// ending of a scope.
573 void identifyScopeMarkers();
575 /// \brief If Var is an current function argument that add it in
576 /// CurrentFnArguments list.
577 bool addCurrentFnArgument(const MachineFunction *MF,
578 DbgVariable *Var, LexicalScope *Scope);
580 /// \brief Populate LexicalScope entries with variables' info.
581 void collectVariableInfo(const MachineFunction *,
582 SmallPtrSet<const MDNode *, 16> &ProcessedVars);
584 /// \brief Collect variable information from the side table maintained
586 void collectVariableInfoFromMMITable(const MachineFunction * MF,
587 SmallPtrSet<const MDNode *, 16> &P);
589 /// \brief Ensure that a label will be emitted before MI.
590 void requestLabelBeforeInsn(const MachineInstr *MI) {
591 LabelsBeforeInsn.insert(std::make_pair(MI, (MCSymbol*)0));
594 /// \brief Return Label preceding the instruction.
595 MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
597 /// \brief Ensure that a label will be emitted after MI.
598 void requestLabelAfterInsn(const MachineInstr *MI) {
599 LabelsAfterInsn.insert(std::make_pair(MI, (MCSymbol*)0));
602 /// \brief Return Label immediately following the instruction.
603 MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
606 //===--------------------------------------------------------------------===//
607 // Main entry points.
609 DwarfDebug(AsmPrinter *A, Module *M);
612 /// \brief Emit all Dwarf sections that should come prior to the
616 /// \brief Emit all Dwarf sections that should come after the content.
619 /// \brief Gather pre-function debug information.
620 void beginFunction(const MachineFunction *MF);
622 /// \brief Gather and emit post-function debug information.
623 void endFunction(const MachineFunction *MF);
625 /// \brief Process beginning of an instruction.
626 void beginInstruction(const MachineInstr *MI);
628 /// \brief Process end of an instruction.
629 void endInstruction(const MachineInstr *MI);
631 /// \brief Look up the source id with the given directory and source file
632 /// names. If none currently exists, create a new id and insert it in the
634 unsigned getOrCreateSourceID(StringRef DirName, StringRef FullName,
637 /// \brief Recursively Emits a debug information entry.
638 void emitDIE(DIE *Die, std::vector<DIEAbbrev *> *Abbrevs);
640 /// \brief Returns whether or not to limit some of our debug
641 /// output to the limitations of darwin gdb.
642 bool useDarwinGDBCompat() { return IsDarwinGDBCompat; }
644 // Experimental DWARF5 features.
646 /// \brief Returns whether or not to emit tables that dwarf consumers can
647 /// use to accelerate lookup.
648 bool useDwarfAccelTables() { return HasDwarfAccelTables; }
650 /// \brief Returns whether or not to change the current debug info for the
651 /// split dwarf proposal support.
652 bool useSplitDwarf() { return HasSplitDwarf; }
654 } // End of namespace llvm