1//===-- llvm/CodeGen/DwarfDebug.h - Dwarf Debug Framework ------*- C++ -*--===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains support for writing dwarf debug info into asm files.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef CODEGEN_ASMPRINTER_DWARFDEBUG_H__
15#define CODEGEN_ASMPRINTER_DWARFDEBUG_H__
16
17#include "DIE.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/SmallPtrSet.h"
25#include "llvm/ADT/StringMap.h"
26#include "llvm/ADT/UniqueVector.h"
27#include "llvm/Support/Allocator.h"
28#include "llvm/Support/DebugLoc.h"
29
30namespace llvm {
31
32class CompileUnit;
33class ConstantInt;
34class ConstantFP;
35class DbgVariable;
36class MachineFrameInfo;
37class MachineModuleInfo;
38class MachineOperand;
39class MCAsmInfo;
40class DIEAbbrev;
41class DIE;
42class DIEBlock;
43class DIEEntry;
44
45//===----------------------------------------------------------------------===//
46/// SrcLineInfo - This class is used to record source line correspondence.
47///
48class SrcLineInfo {
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.
53public:
54  SrcLineInfo(unsigned L, unsigned C, unsigned S, MCSymbol *label)
55    : Line(L), Column(C), SourceID(S), Label(label) {}
56
57  // Accessors
58  unsigned getLine() const { return Line; }
59  unsigned getColumn() const { return Column; }
60  unsigned getSourceID() const { return SourceID; }
61  MCSymbol *getLabel() const { return Label; }
62};
63
64/// DotDebugLocEntry - This struct describes location entries emitted in
65/// .debug_loc section.
66typedef struct DotDebugLocEntry {
67  const MCSymbol *Begin;
68  const MCSymbol *End;
69  MachineLocation Loc;
70  const MDNode *Variable;
71  bool Merged;
72  bool Constant;
73  enum EntryType {
74    E_Location,
75    E_Integer,
76    E_ConstantFP,
77    E_ConstantInt
78  };
79  enum EntryType EntryKind;
80
81  union {
82    int64_t Int;
83    const ConstantFP *CFP;
84    const ConstantInt *CIP;
85  } Constants;
86  DotDebugLocEntry()
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,
90                   const MDNode *V)
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; }
103
104  /// 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))
110      return;
111    Next->Begin = Begin;
112    Merged = true;
113  }
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; }
121} DotDebugLocEntry;
122
123//===----------------------------------------------------------------------===//
124/// DbgVariable - This class is used to track local variable information.
125///
126class DbgVariable {
127  DIVariable Var;                    // Variable Descriptor.
128  DIE *TheDIE;                       // Variable DIE.
129  unsigned DotDebugLocOffset;        // Offset in DotDebugLocEntries.
130  DbgVariable *AbsVar;               // Corresponding Abstract variable, if any.
131  const MachineInstr *MInsn;         // DBG_VALUE instruction of the variable.
132  int FrameIndex;
133public:
134  // AbsVar may be NULL.
135  DbgVariable(DIVariable V, DbgVariable *AV)
136    : Var(V), TheDIE(0), DotDebugLocOffset(~0U), AbsVar(AV), MInsn(0),
137      FrameIndex(~0) {}
138
139  // Accessors.
140  DIVariable getVariable()           const { return Var; }
141  void setDIE(DIE *D)                      { TheDIE = D; }
142  DIE *getDIE()                      const { return TheDIE; }
143  void setDotDebugLocOffset(unsigned O)    { DotDebugLocOffset = O; }
144  unsigned getDotDebugLocOffset()    const { return DotDebugLocOffset; }
145  StringRef getName()                const { return Var.getName(); }
146  DbgVariable *getAbstractVariable() const { return AbsVar; }
147  const MachineInstr *getMInsn()     const { return MInsn; }
148  void setMInsn(const MachineInstr *M)     { MInsn = M; }
149  int getFrameIndex()                const { return FrameIndex; }
150  void setFrameIndex(int FI)               { FrameIndex = FI; }
151  // Translate tag to proper Dwarf tag.
152  unsigned getTag()                  const {
153    if (Var.getTag() == dwarf::DW_TAG_arg_variable)
154      return dwarf::DW_TAG_formal_parameter;
155
156    return dwarf::DW_TAG_variable;
157  }
158  /// isArtificial - Return true if DbgVariable is artificial.
159  bool isArtificial()                const {
160    if (Var.isArtificial())
161      return true;
162    if (getType().isArtificial())
163      return true;
164    return false;
165  }
166
167  bool isObjectPointer()             const {
168    if (Var.isObjectPointer())
169      return true;
170    if (getType().isObjectPointer())
171      return true;
172    return false;
173  }
174
175  bool variableHasComplexAddress()   const {
176    assert(Var.Verify() && "Invalid complex DbgVariable!");
177    return Var.hasComplexAddress();
178  }
179  bool isBlockByrefVariable()        const {
180    assert(Var.Verify() && "Invalid complex DbgVariable!");
181    return Var.isBlockByrefVariable();
182  }
183  unsigned getNumAddrElements()      const {
184    assert(Var.Verify() && "Invalid complex DbgVariable!");
185    return Var.getNumAddrElements();
186  }
187  uint64_t getAddrElement(unsigned i) const {
188    return Var.getAddrElement(i);
189  }
190  DIType getType() const;
191};
192
193class DwarfDebug {
194  /// Asm - Target of Dwarf emission.
195  AsmPrinter *Asm;
196
197  /// MMI - Collected machine module information.
198  MachineModuleInfo *MMI;
199
200  /// DIEValueAllocator - All DIEValues are allocated through this allocator.
201  BumpPtrAllocator DIEValueAllocator;
202
203  //===--------------------------------------------------------------------===//
204  // Attributes used to construct specific Dwarf sections.
205  //
206
207  CompileUnit *FirstCU;
208
209  /// Maps MDNode with its corresponding CompileUnit.
210  DenseMap <const MDNode *, CompileUnit *> CUMap;
211
212  /// Maps subprogram MDNode with its corresponding CompileUnit.
213  DenseMap <const MDNode *, CompileUnit *> SPMap;
214
215  /// AbbreviationsSet - Used to uniquely define abbreviations.
216  ///
217  FoldingSet<DIEAbbrev> AbbreviationsSet;
218
219  /// Abbreviations - A list of all the unique abbreviations in use.
220  ///
221  std::vector<DIEAbbrev *> Abbreviations;
222
223  /// SourceIdMap - 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;
226
227  /// StringPool - A String->Symbol mapping of strings used by indirect
228  /// references.
229  StringMap<std::pair<MCSymbol*, unsigned>, BumpPtrAllocator&> StringPool;
230  unsigned NextStringPoolNumber;
231
232  /// SectionMap - Provides a unique id per text section.
233  ///
234  UniqueVector<const MCSection*> SectionMap;
235
236  /// CurrentFnArguments - List of Arguments (DbgValues) for current function.
237  SmallVector<DbgVariable *, 8> CurrentFnArguments;
238
239  LexicalScopes LScopes;
240
241  /// AbstractSPDies - Collection of abstract subprogram DIEs.
242  DenseMap<const MDNode *, DIE *> AbstractSPDies;
243
244  /// ScopeVariables - Collection of dbg variables of a scope.
245  DenseMap<LexicalScope *, SmallVector<DbgVariable *, 8> > ScopeVariables;
246
247  /// AbstractVariables - Collection of abstract variables.
248  DenseMap<const MDNode *, DbgVariable *> AbstractVariables;
249
250  /// DotDebugLocEntries - Collection of DotDebugLocEntry.
251  SmallVector<DotDebugLocEntry, 4> DotDebugLocEntries;
252
253  /// InlinedSubprogramDIEs - Collection of subprogram DIEs that are marked
254  /// (at the end of the module) as DW_AT_inline.
255  SmallPtrSet<DIE *, 4> InlinedSubprogramDIEs;
256
257  /// InlineInfo - Keep track of inlined functions and their location.  This
258  /// information is used to populate the debug_inlined section.
259  typedef std::pair<const MCSymbol *, DIE *> InlineInfoLabels;
260  DenseMap<const MDNode *, SmallVector<InlineInfoLabels, 4> > InlineInfo;
261  SmallVector<const MDNode *, 4> InlinedSPNodes;
262
263  // ProcessedSPNodes - This is a collection of subprogram MDNodes that
264  // are processed to create DIEs.
265  SmallPtrSet<const MDNode *, 16> ProcessedSPNodes;
266
267  /// LabelsBeforeInsn - Maps instruction with label emitted before
268  /// instruction.
269  DenseMap<const MachineInstr *, MCSymbol *> LabelsBeforeInsn;
270
271  /// LabelsAfterInsn - Maps instruction with label emitted after
272  /// instruction.
273  DenseMap<const MachineInstr *, MCSymbol *> LabelsAfterInsn;
274
275  /// UserVariables - Every user variable mentioned by a DBG_VALUE instruction
276  /// in order of appearance.
277  SmallVector<const MDNode*, 8> UserVariables;
278
279  /// DbgValues - For each user variable, keep a list of DBG_VALUE
280  /// instructions in order. The list can also contain normal instructions that
281  /// clobber the previous DBG_VALUE.
282  typedef DenseMap<const MDNode*, SmallVector<const MachineInstr*, 4> >
283    DbgValueHistoryMap;
284  DbgValueHistoryMap DbgValues;
285
286  SmallVector<const MCSymbol *, 8> DebugRangeSymbols;
287
288  /// Previous instruction's location information. This is used to determine
289  /// label location to indicate scope boundries in dwarf debug info.
290  DebugLoc PrevInstLoc;
291  MCSymbol *PrevLabel;
292
293  /// PrologEndLoc - This location indicates end of function prologue and
294  /// beginning of function body.
295  DebugLoc PrologEndLoc;
296
297  struct FunctionDebugFrameInfo {
298    unsigned Number;
299    std::vector<MachineMove> Moves;
300
301    FunctionDebugFrameInfo(unsigned Num, const std::vector<MachineMove> &M)
302      : Number(Num), Moves(M) {}
303  };
304
305  std::vector<FunctionDebugFrameInfo> DebugFrames;
306
307  // Section Symbols: these are assembler temporary labels that are emitted at
308  // the beginning of each supported dwarf section.  These are used to form
309  // section offsets and are created by EmitSectionLabels.
310  MCSymbol *DwarfInfoSectionSym, *DwarfAbbrevSectionSym;
311  MCSymbol *DwarfStrSectionSym, *TextSectionSym, *DwarfDebugRangeSectionSym;
312  MCSymbol *DwarfDebugLocSectionSym;
313  MCSymbol *FunctionBeginSym, *FunctionEndSym;
314
315  // As an optimization, there is no need to emit an entry in the directory
316  // table for the same directory as DW_at_comp_dir.
317  StringRef CompilationDir;
318
319  // A holder for the DarwinGDBCompat flag so that the compile unit can use it.
320  bool isDarwinGDBCompat;
321  bool hasDwarfAccelTables;
322private:
323
324  /// assignAbbrevNumber - Define a unique number for the abbreviation.
325  ///
326  void assignAbbrevNumber(DIEAbbrev &Abbrev);
327
328  void addScopeVariable(LexicalScope *LS, DbgVariable *Var);
329
330  /// findAbstractVariable - Find abstract variable associated with Var.
331  DbgVariable *findAbstractVariable(DIVariable &Var, DebugLoc Loc);
332
333  /// updateSubprogramScopeDIE - Find DIE for the given subprogram and
334  /// attach appropriate DW_AT_low_pc and DW_AT_high_pc attributes.
335  /// If there are global variables in this scope then create and insert
336  /// DIEs for these variables.
337  DIE *updateSubprogramScopeDIE(CompileUnit *SPCU, const MDNode *SPNode);
338
339  /// constructLexicalScope - Construct new DW_TAG_lexical_block
340  /// for this scope and attach DW_AT_low_pc/DW_AT_high_pc labels.
341  DIE *constructLexicalScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
342
343  /// constructInlinedScopeDIE - This scope represents inlined body of
344  /// a function. Construct DIE to represent this concrete inlined copy
345  /// of the function.
346  DIE *constructInlinedScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
347
348  /// constructScopeDIE - Construct a DIE for this scope.
349  DIE *constructScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
350
351  /// EmitSectionLabels - Emit initial Dwarf sections with a label at
352  /// the start of each one.
353  void EmitSectionLabels();
354
355  /// emitDIE - Recursively Emits a debug information entry.
356  ///
357  void emitDIE(DIE *Die);
358
359  /// computeSizeAndOffset - Compute the size and offset of a DIE.
360  ///
361  unsigned computeSizeAndOffset(DIE *Die, unsigned Offset, bool Last);
362
363  /// computeSizeAndOffsets - Compute the size and offset of all the DIEs.
364  ///
365  void computeSizeAndOffsets();
366
367  /// EmitDebugInfo - Emit the debug info section.
368  ///
369  void emitDebugInfo();
370
371  /// emitAbbreviations - Emit the abbreviation section.
372  ///
373  void emitAbbreviations() const;
374
375  /// emitEndOfLineMatrix - Emit the last address of the section and the end of
376  /// the line matrix.
377  ///
378  void emitEndOfLineMatrix(unsigned SectionEnd);
379
380  /// emitAccelNames - Emit visible names into a hashed accelerator table
381  /// section.
382  void emitAccelNames();
383
384  /// emitAccelObjC - Emit objective C classes and categories into a hashed
385  /// accelerator table section.
386  void emitAccelObjC();
387
388  /// emitAccelNamespace - Emit namespace dies into a hashed accelerator
389  /// table.
390  void emitAccelNamespaces();
391
392  /// emitAccelTypes() - Emit type dies into a hashed accelerator table.
393  ///
394  void emitAccelTypes();
395
396  /// emitDebugPubTypes - Emit visible types into a debug pubtypes section.
397  ///
398  void emitDebugPubTypes();
399
400  /// emitDebugStr - Emit visible names into a debug str section.
401  ///
402  void emitDebugStr();
403
404  /// emitDebugLoc - Emit visible names into a debug loc section.
405  ///
406  void emitDebugLoc();
407
408  /// EmitDebugARanges - Emit visible names into a debug aranges section.
409  ///
410  void EmitDebugARanges();
411
412  /// emitDebugRanges - Emit visible names into a debug ranges section.
413  ///
414  void emitDebugRanges();
415
416  /// emitDebugMacInfo - Emit visible names into a debug macinfo section.
417  ///
418  void emitDebugMacInfo();
419
420  /// emitDebugInlineInfo - Emit inline info using following format.
421  /// Section Header:
422  /// 1. length of section
423  /// 2. Dwarf version number
424  /// 3. address size.
425  ///
426  /// Entries (one "entry" for each function that was inlined):
427  ///
428  /// 1. offset into __debug_str section for MIPS linkage name, if exists;
429  ///   otherwise offset into __debug_str for regular function name.
430  /// 2. offset into __debug_str section for regular function name.
431  /// 3. an unsigned LEB128 number indicating the number of distinct inlining
432  /// instances for the function.
433  ///
434  /// The rest of the entry consists of a {die_offset, low_pc} pair for each
435  /// inlined instance; the die_offset points to the inlined_subroutine die in
436  /// the __debug_info section, and the low_pc is the starting address for the
437  /// inlining instance.
438  void emitDebugInlineInfo();
439
440  /// constructCompileUnit - Create new CompileUnit for the given
441  /// metadata node with tag DW_TAG_compile_unit.
442  CompileUnit *constructCompileUnit(const MDNode *N);
443
444  /// construct SubprogramDIE - Construct subprogram DIE.
445  void constructSubprogramDIE(CompileUnit *TheCU, const MDNode *N);
446
447  /// recordSourceLine - Register a source line with debug info. Returns the
448  /// unique label that was emitted and which provides correspondence to
449  /// the source line list.
450  void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
451                        unsigned Flags);
452
453  /// identifyScopeMarkers() - Indentify instructions that are marking the
454  /// beginning of or ending of a scope.
455  void identifyScopeMarkers();
456
457  /// addCurrentFnArgument - If Var is an current function argument that add
458  /// it in CurrentFnArguments list.
459  bool addCurrentFnArgument(const MachineFunction *MF,
460                            DbgVariable *Var, LexicalScope *Scope);
461
462  /// collectVariableInfo - Populate LexicalScope entries with variables' info.
463  void collectVariableInfo(const MachineFunction *,
464                           SmallPtrSet<const MDNode *, 16> &ProcessedVars);
465
466  /// collectVariableInfoFromMMITable - Collect variable information from
467  /// side table maintained by MMI.
468  void collectVariableInfoFromMMITable(const MachineFunction * MF,
469                                       SmallPtrSet<const MDNode *, 16> &P);
470
471  /// requestLabelBeforeInsn - Ensure that a label will be emitted before MI.
472  void requestLabelBeforeInsn(const MachineInstr *MI) {
473    LabelsBeforeInsn.insert(std::make_pair(MI, (MCSymbol*)0));
474  }
475
476  /// getLabelBeforeInsn - Return Label preceding the instruction.
477  const MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
478
479  /// requestLabelAfterInsn - Ensure that a label will be emitted after MI.
480  void requestLabelAfterInsn(const MachineInstr *MI) {
481    LabelsAfterInsn.insert(std::make_pair(MI, (MCSymbol*)0));
482  }
483
484  /// getLabelAfterInsn - Return Label immediately following the instruction.
485  const MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
486
487public:
488  //===--------------------------------------------------------------------===//
489  // Main entry points.
490  //
491  DwarfDebug(AsmPrinter *A, Module *M);
492  ~DwarfDebug();
493
494  /// collectInfoFromNamedMDNodes - Collect debug info from named mdnodes such
495  /// as llvm.dbg.enum and llvm.dbg.ty
496  void collectInfoFromNamedMDNodes(Module *M);
497
498  /// collectLegacyDebugInfo - Collect debug info using DebugInfoFinder.
499  /// FIXME - Remove this when DragonEgg switches to DIBuilder.
500  bool collectLegacyDebugInfo(Module *M);
501
502  /// beginModule - Emit all Dwarf sections that should come prior to the
503  /// content.
504  void beginModule(Module *M);
505
506  /// endModule - Emit all Dwarf sections that should come after the content.
507  ///
508  void endModule();
509
510  /// beginFunction - Gather pre-function debug information.  Assumes being
511  /// emitted immediately after the function entry point.
512  void beginFunction(const MachineFunction *MF);
513
514  /// endFunction - Gather and emit post-function debug information.
515  ///
516  void endFunction(const MachineFunction *MF);
517
518  /// beginInstruction - Process beginning of an instruction.
519  void beginInstruction(const MachineInstr *MI);
520
521  /// endInstruction - Prcess end of an instruction.
522  void endInstruction(const MachineInstr *MI);
523
524  /// GetOrCreateSourceID - Look up the source id with the given directory and
525  /// source file names. If none currently exists, create a new id and insert it
526  /// in the SourceIds map.
527  unsigned GetOrCreateSourceID(StringRef DirName, StringRef FullName);
528
529  /// getStringPool - returns the entry into the start of the pool.
530  MCSymbol *getStringPool();
531
532  /// getStringPoolEntry - returns an entry into the string pool with the given
533  /// string text.
534  MCSymbol *getStringPoolEntry(StringRef Str);
535
536  /// useDarwinGDBCompat - returns whether or not to limit some of our debug
537  /// output to the limitations of darwin gdb.
538  bool useDarwinGDBCompat() { return isDarwinGDBCompat; }
539  bool useDwarfAccelTables() { return hasDwarfAccelTables; }
540};
541} // End of namespace llvm
542
543#endif
544