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 /// \brief Collects and handles information specific to a particular
199 /// collection of units.
201 // Target of Dwarf emission, used for sizing of abbreviations.
204 // Used to uniquely define abbreviations.
205 FoldingSet<DIEAbbrev> *AbbreviationsSet;
207 // A list of all the unique abbreviations in use.
208 std::vector<DIEAbbrev *> *Abbreviations;
210 // A pointer to all units in the section.
211 SmallVector<CompileUnit *, 1> CUs;
213 // Collection of strings for this unit and assorted symbols.
215 unsigned NextStringPoolNumber;
216 std::string StringPref;
219 DwarfUnits(AsmPrinter *AP, FoldingSet<DIEAbbrev> *AS,
220 std::vector<DIEAbbrev *> *A, const char *Pref,
221 BumpPtrAllocator &DA) :
222 Asm(AP), AbbreviationsSet(AS), Abbreviations(A),
223 StringPool(DA), NextStringPoolNumber(0), StringPref(Pref) {}
225 /// \brief Compute the size and offset of a DIE given an incoming Offset.
226 unsigned computeSizeAndOffset(DIE *Die, unsigned Offset);
228 /// \brief Compute the size and offset of all the DIEs.
229 void computeSizeAndOffsets();
231 /// \brief Define a unique number for the abbreviation.
232 void assignAbbrevNumber(DIEAbbrev &Abbrev);
234 /// \brief Add a unit to the list of CUs.
235 void addUnit(CompileUnit *CU) { CUs.push_back(CU); }
237 /// \brief Emit all of the units to the section listed with the given
238 /// abbreviation section.
239 void emitUnits(DwarfDebug *, const MCSection *, const MCSection *,
242 /// \brief Emit all of the strings to the section given.
243 void emitStrings(const MCSection *, const MCSection *, const MCSymbol *);
245 /// \brief Returns the entry into the start of the pool.
246 MCSymbol *getStringPoolSym();
248 /// \brief Returns an entry into the string pool with the given
250 MCSymbol *getStringPoolEntry(StringRef Str);
252 /// \brief Returns the index into the string pool with the given
254 unsigned getStringPoolIndex(StringRef Str);
256 /// \brief Returns the string pool.
257 StrPool *getStringPool() { return &StringPool; }
260 /// \brief Collects and handles dwarf debug information.
262 // Target of Dwarf emission.
265 // Collected machine module information.
266 MachineModuleInfo *MMI;
268 // All DIEValues are allocated through this allocator.
269 BumpPtrAllocator DIEValueAllocator;
271 //===--------------------------------------------------------------------===//
272 // Attribute used to construct specific Dwarf sections.
275 CompileUnit *FirstCU;
277 // Maps MDNode with its corresponding CompileUnit.
278 DenseMap <const MDNode *, CompileUnit *> CUMap;
280 // Maps subprogram MDNode with its corresponding CompileUnit.
281 DenseMap <const MDNode *, CompileUnit *> SPMap;
283 // Used to uniquely define abbreviations.
284 FoldingSet<DIEAbbrev> AbbreviationsSet;
286 // A list of all the unique abbreviations in use.
287 std::vector<DIEAbbrev *> Abbreviations;
289 // Source id map, i.e. pair of source filename and directory,
290 // separated by a zero byte, mapped to a unique id.
291 StringMap<unsigned, BumpPtrAllocator&> SourceIdMap;
293 // Provides a unique id per text section.
294 SetVector<const MCSection*> SectionMap;
296 // List of Arguments (DbgValues) for current function.
297 SmallVector<DbgVariable *, 8> CurrentFnArguments;
299 LexicalScopes LScopes;
301 // Collection of abstract subprogram DIEs.
302 DenseMap<const MDNode *, DIE *> AbstractSPDies;
304 // Collection of dbg variables of a scope.
305 DenseMap<LexicalScope *, SmallVector<DbgVariable *, 8> > ScopeVariables;
307 // Collection of abstract variables.
308 DenseMap<const MDNode *, DbgVariable *> AbstractVariables;
310 // Collection of DotDebugLocEntry.
311 SmallVector<DotDebugLocEntry, 4> DotDebugLocEntries;
313 // Collection of subprogram DIEs that are marked (at the end of the module)
315 SmallPtrSet<DIE *, 4> InlinedSubprogramDIEs;
317 // Keep track of inlined functions and their location. This
318 // information is used to populate the debug_inlined section.
319 typedef std::pair<const MCSymbol *, DIE *> InlineInfoLabels;
320 DenseMap<const MDNode *, SmallVector<InlineInfoLabels, 4> > InlineInfo;
321 SmallVector<const MDNode *, 4> InlinedSPNodes;
323 // This is a collection of subprogram MDNodes that are processed to
325 SmallPtrSet<const MDNode *, 16> ProcessedSPNodes;
327 // Maps instruction with label emitted before instruction.
328 DenseMap<const MachineInstr *, MCSymbol *> LabelsBeforeInsn;
330 // Maps instruction with label emitted after instruction.
331 DenseMap<const MachineInstr *, MCSymbol *> LabelsAfterInsn;
333 // Every user variable mentioned by a DBG_VALUE instruction in order of
335 SmallVector<const MDNode*, 8> UserVariables;
337 // For each user variable, keep a list of DBG_VALUE instructions in order.
338 // The list can also contain normal instructions that clobber the previous
340 typedef DenseMap<const MDNode*, SmallVector<const MachineInstr*, 4> >
342 DbgValueHistoryMap DbgValues;
344 SmallVector<const MCSymbol *, 8> DebugRangeSymbols;
346 // Previous instruction's location information. This is used to determine
347 // label location to indicate scope boundries in dwarf debug info.
348 DebugLoc PrevInstLoc;
351 // This location indicates end of function prologue and beginning of function
353 DebugLoc PrologEndLoc;
355 struct FunctionDebugFrameInfo {
357 std::vector<MachineMove> Moves;
359 FunctionDebugFrameInfo(unsigned Num, const std::vector<MachineMove> &M)
360 : Number(Num), Moves(M) {}
363 std::vector<FunctionDebugFrameInfo> DebugFrames;
365 // Section Symbols: these are assembler temporary labels that are emitted at
366 // the beginning of each supported dwarf section. These are used to form
367 // section offsets and are created by EmitSectionLabels.
368 MCSymbol *DwarfInfoSectionSym, *DwarfAbbrevSectionSym;
369 MCSymbol *DwarfStrSectionSym, *TextSectionSym, *DwarfDebugRangeSectionSym;
370 MCSymbol *DwarfDebugLocSectionSym;
371 MCSymbol *FunctionBeginSym, *FunctionEndSym;
372 MCSymbol *DwarfAbbrevDWOSectionSym, *DwarfStrDWOSectionSym;
374 // As an optimization, there is no need to emit an entry in the directory
375 // table for the same directory as DW_at_comp_dir.
376 StringRef CompilationDir;
378 // Counter for assigning globally unique IDs for CUs.
379 unsigned GlobalCUIndexCount;
381 // Holder for the file specific debug information.
382 DwarfUnits InfoHolder;
384 // Holders for the various debug information flags that we might need to
385 // have exposed. See accessor functions below for description.
387 // Whether or not we're emitting info for older versions of gdb on darwin.
388 bool IsDarwinGDBCompat;
390 // DWARF5 Experimental Options
391 bool HasDwarfAccelTables;
394 // Separated Dwarf Variables
395 // In general these will all be for bits that are left in the
396 // original object file, rather than things that are meant
397 // to be in the .dwo sections.
399 // The CU left in the original object file for separated debug info.
400 CompileUnit *SkeletonCU;
402 // Used to uniquely define abbreviations for the skeleton emission.
403 FoldingSet<DIEAbbrev> SkeletonAbbrevSet;
405 // A list of all the unique abbreviations in use.
406 std::vector<DIEAbbrev *> SkeletonAbbrevs;
408 // Holder for the skeleton information.
409 DwarfUnits SkeletonHolder;
413 void addScopeVariable(LexicalScope *LS, DbgVariable *Var);
415 /// \brief Find abstract variable associated with Var.
416 DbgVariable *findAbstractVariable(DIVariable &Var, DebugLoc Loc);
418 /// \brief Find DIE for the given subprogram and attach appropriate
419 /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
420 /// variables in this scope then create and insert DIEs for these
422 DIE *updateSubprogramScopeDIE(CompileUnit *SPCU, const MDNode *SPNode);
424 /// \brief Construct new DW_TAG_lexical_block for this scope and
425 /// attach DW_AT_low_pc/DW_AT_high_pc labels.
426 DIE *constructLexicalScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
428 /// \brief This scope represents inlined body of a function. Construct
429 /// DIE to represent this concrete inlined copy of the function.
430 DIE *constructInlinedScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
432 /// \brief Construct a DIE for this scope.
433 DIE *constructScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
435 /// \brief Emit initial Dwarf sections with a label at the start of each one.
436 void emitSectionLabels();
438 /// \brief Compute the size and offset of a DIE given an incoming Offset.
439 unsigned computeSizeAndOffset(DIE *Die, unsigned Offset);
441 /// \brief Compute the size and offset of all the DIEs.
442 void computeSizeAndOffsets();
444 /// \brief Attach DW_AT_inline attribute with inlined subprogram DIEs.
445 void computeInlinedDIEs();
447 /// \brief Collect info for variables that were optimized out.
448 void collectDeadVariables();
450 /// \brief Finish off debug information after all functions have been
452 void finalizeModuleInfo();
454 /// \brief Emit labels to close any remaining sections that have been left
458 /// \brief Emit a set of abbreviations to the specific section.
459 void emitAbbrevs(const MCSection *, std::vector<DIEAbbrev*> *);
461 /// \brief Emit the debug info section.
462 void emitDebugInfo();
464 /// \brief Emit the abbreviation section.
465 void emitAbbreviations();
467 /// \brief Emit the last address of the section and the end of
469 void emitEndOfLineMatrix(unsigned SectionEnd);
471 /// \brief Emit visible names into a hashed accelerator table section.
472 void emitAccelNames();
474 /// \brief Emit objective C classes and categories into a hashed
475 /// accelerator table section.
476 void emitAccelObjC();
478 /// \brief Emit namespace dies into a hashed accelerator table.
479 void emitAccelNamespaces();
481 /// \brief Emit type dies into a hashed accelerator table.
482 void emitAccelTypes();
484 /// \brief Emit visible types into a debug pubtypes section.
485 void emitDebugPubTypes();
487 /// \brief Emit visible names into a debug str section.
490 /// \brief Emit visible names into a debug loc section.
493 /// \brief Emit visible names into a debug aranges section.
494 void emitDebugARanges();
496 /// \brief Emit visible names into a debug ranges section.
497 void emitDebugRanges();
499 /// \brief Emit visible names into a debug macinfo section.
500 void emitDebugMacInfo();
502 /// \brief Emit inline info using custom format.
503 void emitDebugInlineInfo();
505 /// DWARF 5 Experimental Split Dwarf Emitters
507 /// \brief Construct the split debug info compile unit for the debug info
509 CompileUnit *constructSkeletonCU(const MDNode *);
511 /// \brief Emit the local split debug info section.
512 void emitSkeletonCU(const MCSection *);
514 /// \brief Emit the local split abbreviations.
515 void emitSkeletonAbbrevs(const MCSection *);
517 /// \brief Emit the debug info dwo section.
518 void emitDebugInfoDWO();
520 /// \brief Emit the debug abbrev dwo section.
521 void emitDebugAbbrevDWO();
523 /// \brief Emit the debug str dwo section.
524 void emitDebugStrDWO();
526 /// \brief Create new CompileUnit for the given metadata node with tag
527 /// DW_TAG_compile_unit.
528 CompileUnit *constructCompileUnit(const MDNode *N);
530 /// \brief Construct subprogram DIE.
531 void constructSubprogramDIE(CompileUnit *TheCU, const MDNode *N);
533 /// \brief Register a source line with debug info. Returns the unique
534 /// label that was emitted and which provides correspondence to the
535 /// source line list.
536 void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
539 /// \brief Indentify instructions that are marking the beginning of or
540 /// ending of a scope.
541 void identifyScopeMarkers();
543 /// \brief If Var is an current function argument that add it in
544 /// CurrentFnArguments list.
545 bool addCurrentFnArgument(const MachineFunction *MF,
546 DbgVariable *Var, LexicalScope *Scope);
548 /// \brief Populate LexicalScope entries with variables' info.
549 void collectVariableInfo(const MachineFunction *,
550 SmallPtrSet<const MDNode *, 16> &ProcessedVars);
552 /// \brief Collect variable information from the side table maintained
554 void collectVariableInfoFromMMITable(const MachineFunction * MF,
555 SmallPtrSet<const MDNode *, 16> &P);
557 /// \brief Ensure that a label will be emitted before MI.
558 void requestLabelBeforeInsn(const MachineInstr *MI) {
559 LabelsBeforeInsn.insert(std::make_pair(MI, (MCSymbol*)0));
562 /// \brief Return Label preceding the instruction.
563 const MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
565 /// \brief Ensure that a label will be emitted after MI.
566 void requestLabelAfterInsn(const MachineInstr *MI) {
567 LabelsAfterInsn.insert(std::make_pair(MI, (MCSymbol*)0));
570 /// \brief Return Label immediately following the instruction.
571 const MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
574 //===--------------------------------------------------------------------===//
575 // Main entry points.
577 DwarfDebug(AsmPrinter *A, Module *M);
580 /// \brief Collect debug info from named mdnodes such as llvm.dbg.enum
582 void collectInfoFromNamedMDNodes(const Module *M);
584 /// \brief Collect debug info using DebugInfoFinder.
585 /// FIXME - Remove this when DragonEgg switches to DIBuilder.
586 bool collectLegacyDebugInfo(const Module *M);
588 /// \brief Emit all Dwarf sections that should come prior to the
592 /// \brief Emit all Dwarf sections that should come after the content.
595 /// \brief Gather pre-function debug information.
596 void beginFunction(const MachineFunction *MF);
598 /// \brief Gather and emit post-function debug information.
599 void endFunction(const MachineFunction *MF);
601 /// \brief Process beginning of an instruction.
602 void beginInstruction(const MachineInstr *MI);
604 /// \brief Process end of an instruction.
605 void endInstruction(const MachineInstr *MI);
607 /// \brief Look up the source id with the given directory and source file
608 /// names. If none currently exists, create a new id and insert it in the
610 unsigned getOrCreateSourceID(StringRef DirName, StringRef FullName);
612 /// \brief Recursively Emits a debug information entry.
613 void emitDIE(DIE *Die, std::vector<DIEAbbrev *> *Abbrevs);
615 /// \brief Returns whether or not to limit some of our debug
616 /// output to the limitations of darwin gdb.
617 bool useDarwinGDBCompat() { return IsDarwinGDBCompat; }
619 // Experimental DWARF5 features.
621 /// \brief Returns whether or not to emit tables that dwarf consumers can
622 /// use to accelerate lookup.
623 bool useDwarfAccelTables() { return HasDwarfAccelTables; }
625 /// \brief Returns whether or not to change the current debug info for the
626 /// split dwarf proposal support.
627 bool useSplitDwarf() { return HasSplitDwarf; }
629 } // End of namespace llvm