DwarfDebug.h revision 28bea08e531452992ff1e25e8584883dfbd4c232
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 "llvm/CodeGen/AsmPrinter.h"
18#include "llvm/CodeGen/LexicalScopes.h"
19#include "llvm/MC/MachineLocation.h"
20#include "llvm/Analysis/DebugInfo.h"
21#include "DIE.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 DbgConcreteScope;
34class DbgVariable;
35class MachineFrameInfo;
36class MachineModuleInfo;
37class MachineOperand;
38class MCAsmInfo;
39class DIEAbbrev;
40class DIE;
41class DIEBlock;
42class DIEEntry;
43
44//===----------------------------------------------------------------------===//
45/// SrcLineInfo - This class is used to record source line correspondence.
46///
47class SrcLineInfo {
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.
52public:
53  SrcLineInfo(unsigned L, unsigned C, unsigned S, MCSymbol *label)
54    : Line(L), Column(C), SourceID(S), Label(label) {}
55
56  // Accessors
57  unsigned getLine() const { return Line; }
58  unsigned getColumn() const { return Column; }
59  unsigned getSourceID() const { return SourceID; }
60  MCSymbol *getLabel() const { return Label; }
61};
62
63/// DotDebugLocEntry - This struct describes location entries emitted in
64/// .debug_loc section.
65typedef struct DotDebugLocEntry {
66  const MCSymbol *Begin;
67  const MCSymbol *End;
68  MachineLocation Loc;
69  const MDNode *Variable;
70  bool Merged;
71  bool Constant;
72  enum EntryType {
73    E_Location,
74    E_Integer,
75    E_ConstantFP,
76    E_ConstantInt
77  };
78  enum EntryType EntryKind;
79
80  union {
81    int64_t Int;
82    const ConstantFP *CFP;
83    const ConstantInt *CIP;
84  } Constants;
85  DotDebugLocEntry()
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,
89                   const MDNode *V)
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, const ConstantInt *IPtr)
99    : Begin(B), End(E), Variable(0), Merged(false),
100      Constant(true) { Constants.CIP = IPtr; EntryKind = E_ConstantInt; }
101
102  /// Empty entries are also used as a trigger to emit temp label. Such
103  /// labels are referenced is used to find debug_loc offset for a given DIE.
104  bool isEmpty() { return Begin == 0 && End == 0; }
105  bool isMerged() { return Merged; }
106  void Merge(DotDebugLocEntry *Next) {
107    if (!(Begin && Loc == Next->Loc && End == Next->Begin))
108      return;
109    Next->Begin = Begin;
110    Merged = true;
111  }
112  bool isLocation() const    { return EntryKind == E_Location; }
113  bool isInt() const         { return EntryKind == E_Integer; }
114  bool isConstantFP() const  { return EntryKind == E_ConstantFP; }
115  bool isConstantInt() const { return EntryKind == E_ConstantInt; }
116  int64_t getInt()                    { return Constants.Int; }
117  const ConstantFP *getConstantFP()   { return Constants.CFP; }
118  const ConstantInt *getConstantInt() { return Constants.CIP; }
119} DotDebugLocEntry;
120
121//===----------------------------------------------------------------------===//
122/// DbgVariable - This class is used to track local variable information.
123///
124class DbgVariable {
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.
130  int FrameIndex;
131public:
132  // AbsVar may be NULL.
133  DbgVariable(DIVariable V, DbgVariable *AV)
134    : Var(V), TheDIE(0), DotDebugLocOffset(~0U), AbsVar(AV), MInsn(0),
135      FrameIndex(~0) {}
136
137  // Accessors.
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;
153
154    return dwarf::DW_TAG_variable;
155  }
156  /// isArtificial - Return true if DbgVariable is artificial.
157  bool isArtificial()                const {
158    if (Var.isArtificial())
159      return true;
160    if (Var.getTag() == dwarf::DW_TAG_arg_variable
161        && getType().isArtificial())
162      return true;
163    return false;
164  }
165  bool variableHasComplexAddress()   const {
166    assert(Var.Verify() && "Invalid complex DbgVariable!");
167    return Var.hasComplexAddress();
168  }
169  bool isBlockByrefVariable()        const {
170    assert(Var.Verify() && "Invalid complex DbgVariable!");
171    return Var.isBlockByrefVariable();
172  }
173  unsigned getNumAddrElements()      const {
174    assert(Var.Verify() && "Invalid complex DbgVariable!");
175    return Var.getNumAddrElements();
176  }
177  uint64_t getAddrElement(unsigned i) const {
178    return Var.getAddrElement(i);
179  }
180  DIType getType() const;
181};
182
183class DwarfDebug {
184  /// Asm - Target of Dwarf emission.
185  AsmPrinter *Asm;
186
187  /// MMI - Collected machine module information.
188  MachineModuleInfo *MMI;
189
190  //===--------------------------------------------------------------------===//
191  // Attributes used to construct specific Dwarf sections.
192  //
193
194  CompileUnit *FirstCU;
195
196  /// Maps MDNode with its corresponding CompileUnit.
197  DenseMap <const MDNode *, CompileUnit *> CUMap;
198
199  /// Maps subprogram MDNode with its corresponding CompileUnit.
200  DenseMap <const MDNode *, CompileUnit *> SPMap;
201
202  /// AbbreviationsSet - Used to uniquely define abbreviations.
203  ///
204  FoldingSet<DIEAbbrev> AbbreviationsSet;
205
206  /// Abbreviations - A list of all the unique abbreviations in use.
207  ///
208  std::vector<DIEAbbrev *> Abbreviations;
209
210  /// SourceIdMap - Source id map, i.e. pair of directory id and source file
211  /// id mapped to a unique id.
212  StringMap<unsigned> SourceIdMap;
213
214  /// StringPool - A String->Symbol mapping of strings used by indirect
215  /// references.
216  StringMap<std::pair<MCSymbol*, unsigned> > StringPool;
217  unsigned NextStringPoolNumber;
218
219  MCSymbol *getStringPoolEntry(StringRef Str);
220
221  /// SectionMap - Provides a unique id per text section.
222  ///
223  UniqueVector<const MCSection*> SectionMap;
224
225  /// CurrentFnArguments - List of Arguments (DbgValues) for current function.
226  SmallVector<DbgVariable *, 8> CurrentFnArguments;
227
228  LexicalScopes LScopes;
229
230  /// AbstractSPDies - Collection of abstract subprogram DIEs.
231  DenseMap<const MDNode *, DIE *> AbstractSPDies;
232
233  /// ScopeVariables - Collection of dbg variables of a scope.
234  DenseMap<LexicalScope *, SmallVector<DbgVariable *, 8> > ScopeVariables;
235
236  /// AbstractVariables - Collection on abstract variables.
237  DenseMap<const MDNode *, DbgVariable *> AbstractVariables;
238
239  /// DotDebugLocEntries - Collection of DotDebugLocEntry.
240  SmallVector<DotDebugLocEntry, 4> DotDebugLocEntries;
241
242  /// InliendSubprogramDIEs - Collection of subprgram DIEs that are marked
243  /// (at the end of the module) as DW_AT_inline.
244  SmallPtrSet<DIE *, 4> InlinedSubprogramDIEs;
245
246  /// InlineInfo - Keep track of inlined functions and their location.  This
247  /// information is used to populate debug_inlined section.
248  typedef std::pair<const MCSymbol *, DIE *> InlineInfoLabels;
249  DenseMap<const MDNode *, SmallVector<InlineInfoLabels, 4> > InlineInfo;
250  SmallVector<const MDNode *, 4> InlinedSPNodes;
251
252  // ProcessedSPNodes - This is a collection of subprogram MDNodes that
253  // are processed to create DIEs.
254  SmallPtrSet<const MDNode *, 16> ProcessedSPNodes;
255
256  /// LabelsBeforeInsn - Maps instruction with label emitted before
257  /// instruction.
258  DenseMap<const MachineInstr *, MCSymbol *> LabelsBeforeInsn;
259
260  /// LabelsAfterInsn - Maps instruction with label emitted after
261  /// instruction.
262  DenseMap<const MachineInstr *, MCSymbol *> LabelsAfterInsn;
263
264  /// UserVariables - Every user variable mentioned by a DBG_VALUE instruction
265  /// in order of appearance.
266  SmallVector<const MDNode*, 8> UserVariables;
267
268  /// DbgValues - For each user variable, keep a list of DBG_VALUE
269  /// instructions in order. The list can also contain normal instructions that
270  /// clobber the previous DBG_VALUE.
271  typedef DenseMap<const MDNode*, SmallVector<const MachineInstr*, 4> >
272    DbgValueHistoryMap;
273  DbgValueHistoryMap DbgValues;
274
275  SmallVector<const MCSymbol *, 8> DebugRangeSymbols;
276
277  /// Previous instruction's location information. This is used to determine
278  /// label location to indicate scope boundries in dwarf debug info.
279  DebugLoc PrevInstLoc;
280  MCSymbol *PrevLabel;
281
282  /// PrologEndLoc - This location indicates end of function prologue and
283  /// beginning of function body.
284  DebugLoc PrologEndLoc;
285
286  struct FunctionDebugFrameInfo {
287    unsigned Number;
288    std::vector<MachineMove> Moves;
289
290    FunctionDebugFrameInfo(unsigned Num, const std::vector<MachineMove> &M)
291      : Number(Num), Moves(M) {}
292  };
293
294  std::vector<FunctionDebugFrameInfo> DebugFrames;
295
296  // DIEValueAllocator - All DIEValues are allocated through this allocator.
297  BumpPtrAllocator DIEValueAllocator;
298
299  // Section Symbols: these are assembler temporary labels that are emitted at
300  // the beginning of each supported dwarf section.  These are used to form
301  // section offsets and are created by EmitSectionLabels.
302  MCSymbol *DwarfInfoSectionSym, *DwarfAbbrevSectionSym;
303  MCSymbol *DwarfStrSectionSym, *TextSectionSym, *DwarfDebugRangeSectionSym;
304  MCSymbol *DwarfDebugLocSectionSym;
305  MCSymbol *FunctionBeginSym, *FunctionEndSym;
306
307private:
308
309  /// assignAbbrevNumber - Define a unique number for the abbreviation.
310  ///
311  void assignAbbrevNumber(DIEAbbrev &Abbrev);
312
313  void addScopeVariable(LexicalScope *LS, DbgVariable *Var);
314
315  /// findAbstractVariable - Find abstract variable associated with Var.
316  DbgVariable *findAbstractVariable(DIVariable &Var, DebugLoc Loc);
317
318  /// updateSubprogramScopeDIE - Find DIE for the given subprogram and
319  /// attach appropriate DW_AT_low_pc and DW_AT_high_pc attributes.
320  /// If there are global variables in this scope then create and insert
321  /// DIEs for these variables.
322  DIE *updateSubprogramScopeDIE(CompileUnit *SPCU, const MDNode *SPNode);
323
324  /// constructLexicalScope - Construct new DW_TAG_lexical_block
325  /// for this scope and attach DW_AT_low_pc/DW_AT_high_pc labels.
326  DIE *constructLexicalScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
327
328  /// constructInlinedScopeDIE - This scope represents inlined body of
329  /// a function. Construct DIE to represent this concrete inlined copy
330  /// of the function.
331  DIE *constructInlinedScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
332
333  /// constructVariableDIE - Construct a DIE for the given DbgVariable.
334  DIE *constructVariableDIE(DbgVariable *DV, LexicalScope *S);
335
336  /// constructScopeDIE - Construct a DIE for this scope.
337  DIE *constructScopeDIE(CompileUnit *TheCU, LexicalScope *Scope);
338
339  /// EmitSectionLabels - Emit initial Dwarf sections with a label at
340  /// the start of each one.
341  void EmitSectionLabels();
342
343  /// emitDIE - Recusively Emits a debug information entry.
344  ///
345  void emitDIE(DIE *Die);
346
347  /// computeSizeAndOffset - Compute the size and offset of a DIE.
348  ///
349  unsigned computeSizeAndOffset(DIE *Die, unsigned Offset, bool Last);
350
351  /// computeSizeAndOffsets - Compute the size and offset of all the DIEs.
352  ///
353  void computeSizeAndOffsets();
354
355  /// EmitDebugInfo - Emit the debug info section.
356  ///
357  void emitDebugInfo();
358
359  /// emitAbbreviations - Emit the abbreviation section.
360  ///
361  void emitAbbreviations() const;
362
363  /// emitEndOfLineMatrix - Emit the last address of the section and the end of
364  /// the line matrix.
365  ///
366  void emitEndOfLineMatrix(unsigned SectionEnd);
367
368  /// emitDebugPubNames - Emit visible names into a debug pubnames section.
369  ///
370  void emitDebugPubNames();
371
372  /// emitDebugPubTypes - Emit visible types into a debug pubtypes section.
373  ///
374  void emitDebugPubTypes();
375
376  /// emitDebugStr - Emit visible names into a debug str section.
377  ///
378  void emitDebugStr();
379
380  /// emitDebugLoc - Emit visible names into a debug loc section.
381  ///
382  void emitDebugLoc();
383
384  /// EmitDebugARanges - Emit visible names into a debug aranges section.
385  ///
386  void EmitDebugARanges();
387
388  /// emitDebugRanges - Emit visible names into a debug ranges section.
389  ///
390  void emitDebugRanges();
391
392  /// emitDebugMacInfo - Emit visible names into a debug macinfo section.
393  ///
394  void emitDebugMacInfo();
395
396  /// emitDebugInlineInfo - Emit inline info using following format.
397  /// Section Header:
398  /// 1. length of section
399  /// 2. Dwarf version number
400  /// 3. address size.
401  ///
402  /// Entries (one "entry" for each function that was inlined):
403  ///
404  /// 1. offset into __debug_str section for MIPS linkage name, if exists;
405  ///   otherwise offset into __debug_str for regular function name.
406  /// 2. offset into __debug_str section for regular function name.
407  /// 3. an unsigned LEB128 number indicating the number of distinct inlining
408  /// instances for the function.
409  ///
410  /// The rest of the entry consists of a {die_offset, low_pc}  pair for each
411  /// inlined instance; the die_offset points to the inlined_subroutine die in
412  /// the __debug_info section, and the low_pc is the starting address  for the
413  ///  inlining instance.
414  void emitDebugInlineInfo();
415
416  /// constructCompileUnit - Create new CompileUnit for the given
417  /// metadata node with tag DW_TAG_compile_unit.
418  CompileUnit *constructCompileUnit(const MDNode *N);
419
420  /// construct SubprogramDIE - Construct subprogram DIE.
421  void constructSubprogramDIE(CompileUnit *TheCU, const MDNode *N);
422
423  /// recordSourceLine - Register a source line with debug info. Returns the
424  /// unique label that was emitted and which provides correspondence to
425  /// the source line list.
426  void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
427                        unsigned Flags);
428
429  /// identifyScopeMarkers() - Indentify instructions that are marking
430  /// beginning of or end of a scope.
431  void identifyScopeMarkers();
432
433  /// addCurrentFnArgument - If Var is an current function argument that add
434  /// it in CurrentFnArguments list.
435  bool addCurrentFnArgument(const MachineFunction *MF,
436                            DbgVariable *Var, LexicalScope *Scope);
437
438  /// collectVariableInfo - Populate LexicalScope entries with variables' info.
439  void collectVariableInfo(const MachineFunction *,
440                           SmallPtrSet<const MDNode *, 16> &ProcessedVars);
441
442  /// collectVariableInfoFromMMITable - Collect variable information from
443  /// side table maintained by MMI.
444  void collectVariableInfoFromMMITable(const MachineFunction * MF,
445                                       SmallPtrSet<const MDNode *, 16> &P);
446
447  /// requestLabelBeforeInsn - Ensure that a label will be emitted before MI.
448  void requestLabelBeforeInsn(const MachineInstr *MI) {
449    LabelsBeforeInsn.insert(std::make_pair(MI, (MCSymbol*)0));
450  }
451
452  /// getLabelBeforeInsn - Return Label preceding the instruction.
453  const MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
454
455  /// requestLabelAfterInsn - Ensure that a label will be emitted after MI.
456  void requestLabelAfterInsn(const MachineInstr *MI) {
457    LabelsAfterInsn.insert(std::make_pair(MI, (MCSymbol*)0));
458  }
459
460  /// getLabelAfterInsn - Return Label immediately following the instruction.
461  const MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
462
463public:
464  //===--------------------------------------------------------------------===//
465  // Main entry points.
466  //
467  DwarfDebug(AsmPrinter *A, Module *M);
468  ~DwarfDebug();
469
470  /// collectInfoFromNamedMDNodes - Collect debug info from named mdnodes such
471  /// as llvm.dbg.enum and llvm.dbg.ty
472  void collectInfoFromNamedMDNodes(Module *M);
473
474  /// collectLegacyDebugInfo - Collect debug info using DebugInfoFinder.
475  /// FIXME - Remove this when dragon-egg and llvm-gcc switch to DIBuilder.
476  bool collectLegacyDebugInfo(Module *M);
477
478  /// beginModule - Emit all Dwarf sections that should come prior to the
479  /// content.
480  void beginModule(Module *M);
481
482  /// endModule - Emit all Dwarf sections that should come after the content.
483  ///
484  void endModule();
485
486  /// beginFunction - Gather pre-function debug information.  Assumes being
487  /// emitted immediately after the function entry point.
488  void beginFunction(const MachineFunction *MF);
489
490  /// endFunction - Gather and emit post-function debug information.
491  ///
492  void endFunction(const MachineFunction *MF);
493
494  /// beginInstruction - Process beginning of an instruction.
495  void beginInstruction(const MachineInstr *MI);
496
497  /// endInstruction - Prcess end of an instruction.
498  void endInstruction(const MachineInstr *MI);
499
500  /// GetOrCreateSourceID - Look up the source id with the given directory and
501  /// source file names. If none currently exists, create a new id and insert it
502  /// in the SourceIds map.
503  unsigned GetOrCreateSourceID(StringRef DirName, StringRef FullName);
504
505  /// createSubprogramDIE - Create new DIE using SP.
506  DIE *createSubprogramDIE(DISubprogram SP);
507};
508} // End of namespace llvm
509
510#endif
511