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/DebugInfo.h"
19 #include "llvm/CodeGen/AsmPrinter.h"
20 #include "llvm/CodeGen/LexicalScopes.h"
21 #include "llvm/MC/MachineLocation.h"
22 #include "llvm/ADT/DenseMap.h"
23 #include "llvm/ADT/FoldingSet.h"
24 #include "llvm/ADT/SetVector.h"
25 #include "llvm/ADT/SmallPtrSet.h"
26 #include "llvm/ADT/StringMap.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 typedef struct DotDebugLocEntry {
66 const MCSymbol *Begin;
69 const MDNode *Variable;
78 enum EntryType EntryKind;
82 const ConstantFP *CFP;
83 const ConstantInt *CIP;
86 : Begin(0), End(0), Variable(0), Merged(false),
87 Constant(false) { Constants.Int = 0;}
88 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, MachineLocation &L,
90 : Begin(B), End(E), Loc(L), Variable(V), Merged(false),
91 Constant(false) { Constants.Int = 0; EntryKind = E_Location; }
92 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, int64_t i)
93 : Begin(B), End(E), Variable(0), Merged(false),
94 Constant(true) { Constants.Int = i; EntryKind = E_Integer; }
95 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, const ConstantFP *FPtr)
96 : Begin(B), End(E), Variable(0), Merged(false),
97 Constant(true) { Constants.CFP = FPtr; EntryKind = E_ConstantFP; }
98 DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E,
99 const ConstantInt *IPtr)
100 : Begin(B), End(E), Variable(0), Merged(false),
101 Constant(true) { Constants.CIP = IPtr; EntryKind = E_ConstantInt; }
103 /// \brief Empty entries are also used as a trigger to emit temp label. Such
104 /// labels are referenced is used to find debug_loc offset for a given DIE.
105 bool isEmpty() { return Begin == 0 && End == 0; }
106 bool isMerged() { return Merged; }
107 void Merge(DotDebugLocEntry *Next) {
108 if (!(Begin && Loc == Next->Loc && End == Next->Begin))
113 bool isLocation() const { return EntryKind == E_Location; }
114 bool isInt() const { return EntryKind == E_Integer; }
115 bool isConstantFP() const { return EntryKind == E_ConstantFP; }
116 bool isConstantInt() const { return EntryKind == E_ConstantInt; }
117 int64_t getInt() { return Constants.Int; }
118 const ConstantFP *getConstantFP() { return Constants.CFP; }
119 const ConstantInt *getConstantInt() { return Constants.CIP; }
122 //===----------------------------------------------------------------------===//
123 /// \brief This class is used to track local variable information.
125 DIVariable Var; // Variable Descriptor.
126 DIE *TheDIE; // Variable DIE.
127 unsigned DotDebugLocOffset; // Offset in DotDebugLocEntries.
128 DbgVariable *AbsVar; // Corresponding Abstract variable, if any.
129 const MachineInstr *MInsn; // DBG_VALUE instruction of the variable.
132 // AbsVar may be NULL.
133 DbgVariable(DIVariable V, DbgVariable *AV)
134 : Var(V), TheDIE(0), DotDebugLocOffset(~0U), AbsVar(AV), MInsn(0),
138 DIVariable getVariable() const { return Var; }
139 void setDIE(DIE *D) { TheDIE = D; }
140 DIE *getDIE() const { return TheDIE; }
141 void setDotDebugLocOffset(unsigned O) { DotDebugLocOffset = O; }
142 unsigned getDotDebugLocOffset() const { return DotDebugLocOffset; }
143 StringRef getName() const { return Var.getName(); }
144 DbgVariable *getAbstractVariable() const { return AbsVar; }
145 const MachineInstr *getMInsn() const { return MInsn; }
146 void setMInsn(const MachineInstr *M) { MInsn = M; }
147 int getFrameIndex() const { return FrameIndex; }
148 void setFrameIndex(int FI) { FrameIndex = FI; }
149 // Translate tag to proper Dwarf tag.
150 unsigned getTag() const {
151 if (Var.getTag() == dwarf::DW_TAG_arg_variable)
152 return dwarf::DW_TAG_formal_parameter;
154 return dwarf::DW_TAG_variable;
156 /// \brief Return true if DbgVariable is artificial.
157 bool isArtificial() const {
158 if (Var.isArtificial())
160 if (getType().isArtificial())
165 bool isObjectPointer() const {
166 if (Var.isObjectPointer())
168 if (getType().isObjectPointer())
173 bool variableHasComplexAddress() const {
174 assert(Var.Verify() && "Invalid complex DbgVariable!");
175 return Var.hasComplexAddress();
177 bool isBlockByrefVariable() const {
178 assert(Var.Verify() && "Invalid complex DbgVariable!");
179 return Var.isBlockByrefVariable();
181 unsigned getNumAddrElements() const {
182 assert(Var.Verify() && "Invalid complex DbgVariable!");
183 return Var.getNumAddrElements();
185 uint64_t getAddrElement(unsigned i) const {
186 return Var.getAddrElement(i);
188 DIType getType() const;
191 /// \brief Collects and handles dwarf debug information.
193 // Target of Dwarf emission.
196 // Collected machine module information.
197 MachineModuleInfo *MMI;
199 // All DIEValues are allocated through this allocator.
200 BumpPtrAllocator DIEValueAllocator;
202 //===--------------------------------------------------------------------===//
203 // Attributes used to construct specific Dwarf sections.
206 CompileUnit *FirstCU;
208 // The CU left in the original object file for Fission debug info.
209 CompileUnit *FissionCU;
211 // Maps MDNode with its corresponding CompileUnit.
212 DenseMap <const MDNode *, CompileUnit *> CUMap;
214 // Maps subprogram MDNode with its corresponding CompileUnit.
215 DenseMap <const MDNode *, CompileUnit *> SPMap;
217 // Used to uniquely define abbreviations.
218 FoldingSet<DIEAbbrev> AbbreviationsSet;
220 // A list of all the unique abbreviations in use.
221 std::vector<DIEAbbrev *> Abbreviations;
223 // Source id map, i.e. pair of source filename and directory,
224 // separated by a zero byte, mapped to a unique id.
225 StringMap<unsigned, BumpPtrAllocator&> SourceIdMap;
227 // A String->Symbol mapping of strings used by indirect
229 StringMap<std::pair<MCSymbol*, unsigned>, BumpPtrAllocator&> StringPool;
230 unsigned NextStringPoolNumber;
232 // Provides a unique id per text section.
233 SetVector<const MCSection*> SectionMap;
235 // List of Arguments (DbgValues) for current function.
236 SmallVector<DbgVariable *, 8> CurrentFnArguments;
238 LexicalScopes LScopes;
240 // Collection of abstract subprogram DIEs.
241 DenseMap<const MDNode *, DIE *> AbstractSPDies;
243 // Collection of dbg variables of a scope.
244 DenseMap<LexicalScope *, SmallVector<DbgVariable *, 8> > ScopeVariables;
246 // Collection of abstract variables.
247 DenseMap<const MDNode *, DbgVariable *> AbstractVariables;
249 // Collection of DotDebugLocEntry.
250 SmallVector<DotDebugLocEntry, 4> DotDebugLocEntries;
252 // Collection of subprogram DIEs that are marked (at the end of the module)
254 SmallPtrSet<DIE *, 4> InlinedSubprogramDIEs;
256 // Keep track of inlined functions and their location. This
257 // information is used to populate the debug_inlined section.
258 typedef std::pair<const MCSymbol *, DIE *> InlineInfoLabels;
259 DenseMap<const MDNode *, SmallVector<InlineInfoLabels, 4> > InlineInfo;
260 SmallVector<const MDNode *, 4> InlinedSPNodes;
262 // This is a collection of subprogram MDNodes that are processed to create DIEs.
263 SmallPtrSet<const MDNode *, 16> ProcessedSPNodes;
265 // Maps instruction with label emitted before instruction.
266 DenseMap<const MachineInstr *, MCSymbol *> LabelsBeforeInsn;
268 // Maps instruction with label emitted after instruction.
269 DenseMap<const MachineInstr *, MCSymbol *> LabelsAfterInsn;
271 // Every user variable mentioned by a DBG_VALUE instruction in order of
273 SmallVector<const MDNode*, 8> UserVariables;
275 // For each user variable, keep a list of DBG_VALUE instructions in order.
276 // The list can also contain normal instructions that clobber the previous
278 typedef DenseMap<const MDNode*, SmallVector<const MachineInstr*, 4> >
280 DbgValueHistoryMap DbgValues;
282 SmallVector<const MCSymbol *, 8> DebugRangeSymbols;
284 // Previous instruction's location information. This is used to determine
285 // label location to indicate scope boundries in dwarf debug info.
286 DebugLoc PrevInstLoc;
289 // This location indicates end of function prologue and beginning of function
291 DebugLoc PrologEndLoc;
293 struct FunctionDebugFrameInfo {
295 std::vector<MachineMove> Moves;
297 FunctionDebugFrameInfo(unsigned Num, const std::vector<MachineMove> &M)
298 : Number(Num), Moves(M) {}
301 std::vector<FunctionDebugFrameInfo> DebugFrames;
303 // Section Symbols: these are assembler temporary labels that are emitted at
304 // the beginning of each supported dwarf section. These are used to form
305 // section offsets and are created by EmitSectionLabels.
306 MCSymbol *DwarfInfoSectionSym, *DwarfAbbrevSectionSym;
307 MCSymbol *DwarfStrSectionSym, *TextSectionSym, *DwarfDebugRangeSectionSym;
308 MCSymbol *DwarfDebugLocSectionSym;
309 MCSymbol *FunctionBeginSym, *FunctionEndSym;
311 // As an optimization, there is no need to emit an entry in the directory
312 // table for the same directory as DW_at_comp_dir.
313 StringRef CompilationDir;
315 // Holders for the various debug information flags that we might need to
316 // have exposed. See accessor functions below for description.
317 bool IsDarwinGDBCompat;
319 // Counter for assigning globally unique IDs for CUs.
320 unsigned GlobalCUIndexCount;
322 // DWARF5 Experimental Options
323 bool HasDwarfAccelTables;
324 bool HasDwarfFission;
327 /// \brief Define a unique number for the abbreviation.
328 void assignAbbrevNumber(DIEAbbrev &Abbrev);
330 void addScopeVariable(LexicalScope *LS, DbgVariable *Var);
332 /// \brief Find abstract variable associated with Var.
333 DbgVariable *findAbstractVariable(DIVariable &Var, DebugLoc Loc);
335 /// \brief Find DIE for the given subprogram and attach appropriate
336 /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
337 /// variables in this scope then create and insert DIEs for these
339 DIE *updateSubprogramScopeDIE(CompileUnit *SPCU, const MDNode *SPNode);
341 /// \brief Construct new DW_TAG_lexical_block for this scope and
342 /// attach DW_AT_low_pc/DW_AT_high_pc labels.
343 DIE *constructLexicalScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
345 /// \brief This scope represents inlined body of a function. Construct
346 /// DIE to represent this concrete inlined copy of the function.
347 DIE *constructInlinedScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
349 /// \brief Construct a DIE for this scope.
350 DIE *constructScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
352 /// \brief Emit initial Dwarf sections with a label at the start of each one.
353 void emitSectionLabels();
355 /// \brief Recursively Emits a debug information entry.
356 void emitDIE(DIE *Die);
358 /// \brief Compute the size and offset of a DIE given an incoming Offset.
359 unsigned computeSizeAndOffset(DIE *Die, unsigned Offset);
361 /// \brief Compute the size and offset of all the DIEs.
362 void computeSizeAndOffsets();
364 /// \brief Attach DW_AT_inline attribute with inlined subprogram DIEs.
365 void computeInlinedDIEs();
367 /// \brief Collect info for variables that were optimized out.
368 void collectDeadVariables();
370 /// \brief Finish off debug information after all functions have been
372 void finalizeModuleInfo();
374 /// \brief Emit labels to close any remaining sections that have been left
378 /// \brief Emit all of the compile units to the target section.
379 void emitCompileUnits(const MCSection *);
381 /// \brief Emit the debug info section.
382 void emitDebugInfo();
384 /// \brief Emit the abbreviation section.
385 void emitAbbreviations();
387 /// \brief Emit the last address of the section and the end of
389 void emitEndOfLineMatrix(unsigned SectionEnd);
391 /// \brief Emit visible names into a hashed accelerator table section.
392 void emitAccelNames();
394 /// \brief Emit objective C classes and categories into a hashed
395 /// accelerator table section.
396 void emitAccelObjC();
398 /// \brief Emit namespace dies into a hashed accelerator table.
399 void emitAccelNamespaces();
401 /// \brief Emit type dies into a hashed accelerator table.
402 void emitAccelTypes();
404 /// \brief Emit visible types into a debug pubtypes section.
405 void emitDebugPubTypes();
407 /// \brief Emit visible names into a debug str section.
410 /// \brief Emit visible names into a debug loc section.
413 /// \brief Emit visible names into a debug aranges section.
414 void emitDebugARanges();
416 /// \brief Emit visible names into a debug ranges section.
417 void emitDebugRanges();
419 /// \brief Emit visible names into a debug macinfo section.
420 void emitDebugMacInfo();
422 /// \brief Emit inline info using custom format.
423 void emitDebugInlineInfo();
425 /// DWARF 5 Experimental Fission Emitters
427 /// \brief Construct the fission compile unit for the debug info section.
428 CompileUnit *constructFissionCU(const MDNode *);
430 /// \brief Emit the fission debug info section.
431 void emitFissionSkeletonCU(const MCSection *);
433 /// \brief Emit the debug info dwo section.
434 void emitDebugInfoDWO();
436 /// \brief Create new CompileUnit for the given metadata node with tag
437 /// DW_TAG_compile_unit.
438 CompileUnit *constructCompileUnit(const MDNode *N);
440 /// \brief Construct subprogram DIE.
441 void constructSubprogramDIE(CompileUnit *TheCU, const MDNode *N);
443 /// \brief Register a source line with debug info. Returns the unique
444 /// label that was emitted and which provides correspondence to the
445 /// source line list.
446 void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
449 /// \brief Indentify instructions that are marking the beginning of or
450 /// ending of a scope.
451 void identifyScopeMarkers();
453 /// \brief If Var is an current function argument that add it in
454 /// CurrentFnArguments list.
455 bool addCurrentFnArgument(const MachineFunction *MF,
456 DbgVariable *Var, LexicalScope *Scope);
458 /// \brief Populate LexicalScope entries with variables' info.
459 void collectVariableInfo(const MachineFunction *,
460 SmallPtrSet<const MDNode *, 16> &ProcessedVars);
462 /// \brief Collect variable information from the side table maintained
464 void collectVariableInfoFromMMITable(const MachineFunction * MF,
465 SmallPtrSet<const MDNode *, 16> &P);
467 /// \brief Ensure that a label will be emitted before MI.
468 void requestLabelBeforeInsn(const MachineInstr *MI) {
469 LabelsBeforeInsn.insert(std::make_pair(MI, (MCSymbol*)0));
472 /// \brief Return Label preceding the instruction.
473 const MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
475 /// \brief Ensure that a label will be emitted after MI.
476 void requestLabelAfterInsn(const MachineInstr *MI) {
477 LabelsAfterInsn.insert(std::make_pair(MI, (MCSymbol*)0));
480 /// \brief Return Label immediately following the instruction.
481 const MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
484 //===--------------------------------------------------------------------===//
485 // Main entry points.
487 DwarfDebug(AsmPrinter *A, Module *M);
490 /// \brief Collect debug info from named mdnodes such as llvm.dbg.enum
492 void collectInfoFromNamedMDNodes(const Module *M);
494 /// \brief Collect debug info using DebugInfoFinder.
495 /// FIXME - Remove this when DragonEgg switches to DIBuilder.
496 bool collectLegacyDebugInfo(const Module *M);
498 /// \brief Emit all Dwarf sections that should come prior to the
502 /// \brief Emit all Dwarf sections that should come after the content.
505 /// \brief Gather pre-function debug information.
506 void beginFunction(const MachineFunction *MF);
508 /// \brief Gather and emit post-function debug information.
509 void endFunction(const MachineFunction *MF);
511 /// \brief Process beginning of an instruction.
512 void beginInstruction(const MachineInstr *MI);
514 /// \brief Process end of an instruction.
515 void endInstruction(const MachineInstr *MI);
517 /// \brief Look up the source id with the given directory and source file
518 /// names. If none currently exists, create a new id and insert it in the
520 unsigned getOrCreateSourceID(StringRef DirName, StringRef FullName);
522 /// \brief Returns the entry into the start of the pool.
523 MCSymbol *getStringPool();
525 /// \brief Returns an entry into the string pool with the given
527 MCSymbol *getStringPoolEntry(StringRef Str);
529 /// \brief Returns whether or not to limit some of our debug
530 /// output to the limitations of darwin gdb.
531 bool useDarwinGDBCompat() { return IsDarwinGDBCompat; }
533 // Experimental DWARF5 features.
535 /// \brief Returns whether or not to emit tables that dwarf consumers can
536 /// use to accelerate lookup.
537 bool useDwarfAccelTables() { return HasDwarfAccelTables; }
539 /// \brief Returns whether or not to change the current debug info for the
540 /// fission proposal support.
541 bool useDwarfFission() { return HasDwarfFission; }
543 } // End of namespace llvm