lib/CodeGen/AsmPrinter/DwarfDebug.h

   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/MachineLocation.h"
  19 #include "llvm/Analysis/DebugInfo.h"
  20 #include "DIE.h"
  21 #include "llvm/ADT/DenseMap.h"
  22 #include "llvm/ADT/FoldingSet.h"
  23 #include "llvm/ADT/SmallPtrSet.h"
  24 #include "llvm/ADT/StringMap.h"
  25 #include "llvm/ADT/UniqueVector.h"
  26 #include "llvm/Support/Allocator.h"
  27 #include "llvm/Support/DebugLoc.h"
  28
  29 namespace llvm {
  30
  31 class CompileUnit;
  32 class DbgConcreteScope;
  33 class DbgScope;
  34 class DbgVariable;
  35 class MachineFrameInfo;
  36 class MachineModuleInfo;
  37 class MachineOperand;
  38 class MCAsmInfo;
  39 class DIEAbbrev;
  40 class DIE;
  41 class DIEBlock;
  42 class DIEEntry;
  43
  44 //===----------------------------------------------------------------------===//
  45 /// SrcLineInfo - This class is used to record source line correspondence.
  46 ///
  47 class 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.
  52 public:
  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.
  65 typedef 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 ///
 124 class DbgVariable {
 125   DIVariable Var;                    // Variable Descriptor.
 126   DIE *TheDIE;                       // Variable DIE.
 127   unsigned DotDebugLocOffset;        // Offset in DotDebugLocEntries.
 128 public:
 129   // AbsVar may be NULL.
 130   DbgVariable(DIVariable V) : Var(V), TheDIE(0), DotDebugLocOffset(~0U) {}
 131
 132   // Accessors.
 133   DIVariable getVariable()           const { return Var; }
 134   void setDIE(DIE *D)                      { TheDIE = D; }
 135   DIE *getDIE()                      const { return TheDIE; }
 136   void setDotDebugLocOffset(unsigned O)    { DotDebugLocOffset = O; }
 137   unsigned getDotDebugLocOffset()    const { return DotDebugLocOffset; }
 138   StringRef getName()                const { return Var.getName(); }
 139   unsigned getTag()                  const { return Var.getTag(); }
 140   bool variableHasComplexAddress()   const {
 141     assert(Var.Verify() && "Invalid complex DbgVariable!");
 142     return Var.hasComplexAddress();
 143   }
 144   bool isBlockByrefVariable()        const {
 145     assert(Var.Verify() && "Invalid complex DbgVariable!");
 146     return Var.isBlockByrefVariable();
 147   }
 148   unsigned getNumAddrElements()      const {
 149     assert(Var.Verify() && "Invalid complex DbgVariable!");
 150     return Var.getNumAddrElements();
 151   }
 152   uint64_t getAddrElement(unsigned i) const {
 153     return Var.getAddrElement(i);
 154   }
 155   DIType getType() const;
 156 };
 157
 158 class DwarfDebug {
 159   /// Asm - Target of Dwarf emission.
 160   AsmPrinter *Asm;
 161
 162   /// MMI - Collected machine module information.
 163   MachineModuleInfo *MMI;
 164
 165   //===--------------------------------------------------------------------===//
 166   // Attributes used to construct specific Dwarf sections.
 167   //
 168
 169   CompileUnit *FirstCU;
 170   DenseMap <const MDNode *, CompileUnit *> CUMap;
 171
 172   /// AbbreviationsSet - Used to uniquely define abbreviations.
 173   ///
 174   FoldingSet<DIEAbbrev> AbbreviationsSet;
 175
 176   /// Abbreviations - A list of all the unique abbreviations in use.
 177   ///
 178   std::vector<DIEAbbrev *> Abbreviations;
 179
 180   /// SourceIdMap - Source id map, i.e. pair of directory id and source file
 181   /// id mapped to a unique id.
 182   StringMap<unsigned> SourceIdMap;
 183
 184   /// StringPool - A String->Symbol mapping of strings used by indirect
 185   /// references.
 186   StringMap<std::pair<MCSymbol*, unsigned> > StringPool;
 187   unsigned NextStringPoolNumber;
 188
 189   MCSymbol *getStringPoolEntry(StringRef Str);
 190
 191   /// SectionMap - Provides a unique id per text section.
 192   ///
 193   UniqueVector<const MCSection*> SectionMap;
 194
 195   /// CurrentFnDbgScope - Top level scope for the current function.
 196   ///
 197   DbgScope *CurrentFnDbgScope;
 198
 199   /// CurrentFnArguments - List of Arguments (DbgValues) for current function.
 200   SmallVector<DbgVariable *, 8> CurrentFnArguments;
 201
 202   /// DbgScopeMap - Tracks the scopes in the current function.  Owns the
 203   /// contained DbgScope*s.
 204   ///
 205   DenseMap<const MDNode *, DbgScope *> DbgScopeMap;
 206
 207   /// ConcreteScopes - Tracks the concrete scopees in the current function.
 208   /// These scopes are also included in DbgScopeMap.
 209   DenseMap<const MDNode *, DbgScope *> ConcreteScopes;
 210
 211   /// AbstractScopes - Tracks the abstract scopes a module. These scopes are
 212   /// not included DbgScopeMap.  AbstractScopes owns its DbgScope*s.
 213   DenseMap<const MDNode *, DbgScope *> AbstractScopes;
 214
 215   /// AbstractSPDies - Collection of abstract subprogram DIEs.
 216   DenseMap<const MDNode *, DIE *> AbstractSPDies;
 217
 218   /// AbstractScopesList - Tracks abstract scopes constructed while processing
 219   /// a function. This list is cleared during endFunction().
 220   SmallVector<DbgScope *, 4>AbstractScopesList;
 221
 222   /// AbstractVariables - Collection on abstract variables.  Owned by the
 223   /// DbgScopes in AbstractScopes.
 224   DenseMap<const MDNode *, DbgVariable *> AbstractVariables;
 225
 226   /// DbgVariableToFrameIndexMap - Tracks frame index used to find
 227   /// variable's value.
 228   DenseMap<const DbgVariable *, int> DbgVariableToFrameIndexMap;
 229
 230   /// DbgVariableToDbgInstMap - Maps DbgVariable to corresponding DBG_VALUE
 231   /// machine instruction.
 232   DenseMap<const DbgVariable *, const MachineInstr *> DbgVariableToDbgInstMap;
 233
 234   /// DotDebugLocEntries - Collection of DotDebugLocEntry.
 235   SmallVector<DotDebugLocEntry, 4> DotDebugLocEntries;
 236
 237   /// UseDotDebugLocEntry - DW_AT_location attributes for the DIEs in this set
 238   /// idetifies corresponding .debug_loc entry offset.
 239   SmallPtrSet<const DIE *, 4> UseDotDebugLocEntry;
 240
 241   /// VarToAbstractVarMap - Maps DbgVariable with corresponding Abstract
 242   /// DbgVariable, if any.
 243   DenseMap<const DbgVariable *, const DbgVariable *> VarToAbstractVarMap;
 244
 245   /// InliendSubprogramDIEs - Collection of subprgram DIEs that are marked
 246   /// (at the end of the module) as DW_AT_inline.
 247   SmallPtrSet<DIE *, 4> InlinedSubprogramDIEs;
 248
 249   /// ContainingTypeMap - This map is used to keep track of subprogram DIEs that
 250   /// need DW_AT_containing_type attribute. This attribute points to a DIE that
 251   /// corresponds to the MDNode mapped with the subprogram DIE.
 252   DenseMap<DIE *, const MDNode *> ContainingTypeMap;
 253
 254   /// InlineInfo - Keep track of inlined functions and their location.  This
 255   /// information is used to populate debug_inlined section.
 256   typedef std::pair<const MCSymbol *, DIE *> InlineInfoLabels;
 257   DenseMap<const MDNode *, SmallVector<InlineInfoLabels, 4> > InlineInfo;
 258   SmallVector<const MDNode *, 4> InlinedSPNodes;
 259
 260   // ProcessedSPNodes - This is a collection of subprogram MDNodes that
 261   // are processed to create DIEs.
 262   SmallPtrSet<const MDNode *, 16> ProcessedSPNodes;
 263
 264   /// LabelsBeforeInsn - Maps instruction with label emitted before
 265   /// instruction.
 266   DenseMap<const MachineInstr *, MCSymbol *> LabelsBeforeInsn;
 267
 268   /// LabelsAfterInsn - Maps instruction with label emitted after
 269   /// instruction.
 270   DenseMap<const MachineInstr *, MCSymbol *> LabelsAfterInsn;
 271
 272   /// UserVariables - Every user variable mentioned by a DBG_VALUE instruction
 273   /// in order of appearance.
 274   SmallVector<const MDNode*, 8> UserVariables;
 275
 276   /// DbgValues - For each user variable, keep a list of DBG_VALUE
 277   /// instructions in order. The list can also contain normal instructions that
 278   /// clobber the previous DBG_VALUE.
 279   typedef DenseMap<const MDNode*, SmallVector<const MachineInstr*, 4> >
 280     DbgValueHistoryMap;
 281   DbgValueHistoryMap DbgValues;
 282
 283   SmallVector<const MCSymbol *, 8> DebugRangeSymbols;
 284
 285   /// Previous instruction's location information. This is used to determine
 286   /// label location to indicate scope boundries in dwarf debug info.
 287   DebugLoc PrevInstLoc;
 288   MCSymbol *PrevLabel;
 289
 290   /// PrologEndLoc - This location indicates end of function prologue and
 291   /// beginning of function body.
 292   DebugLoc PrologEndLoc;
 293
 294   struct FunctionDebugFrameInfo {
 295     unsigned Number;
 296     std::vector<MachineMove> Moves;
 297
 298     FunctionDebugFrameInfo(unsigned Num, const std::vector<MachineMove> &M)
 299       : Number(Num), Moves(M) {}
 300   };
 301
 302   std::vector<FunctionDebugFrameInfo> DebugFrames;
 303
 304   // DIEValueAllocator - All DIEValues are allocated through this allocator.
 305   BumpPtrAllocator DIEValueAllocator;
 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 private:
 316
 317   /// assignAbbrevNumber - Define a unique number for the abbreviation.
 318   ///
 319   void assignAbbrevNumber(DIEAbbrev &Abbrev);
 320
 321   /// getOrCreateDbgScope - Create DbgScope for the scope.
 322   DbgScope *getOrCreateDbgScope(const MDNode *Scope, const MDNode *InlinedAt);
 323
 324   DbgScope *getOrCreateAbstractScope(const MDNode *N);
 325
 326   /// findAbstractVariable - Find abstract variable associated with Var.
 327   DbgVariable *findAbstractVariable(DIVariable &Var, DebugLoc Loc);
 328
 329   /// updateSubprogramScopeDIE - Find DIE for the given subprogram and
 330   /// attach appropriate DW_AT_low_pc and DW_AT_high_pc attributes.
 331   /// If there are global variables in this scope then create and insert
 332   /// DIEs for these variables.
 333   DIE *updateSubprogramScopeDIE(const MDNode *SPNode);
 334
 335   /// constructLexicalScope - Construct new DW_TAG_lexical_block
 336   /// for this scope and attach DW_AT_low_pc/DW_AT_high_pc labels.
 337   DIE *constructLexicalScopeDIE(DbgScope *Scope);
 338
 339   /// constructInlinedScopeDIE - This scope represents inlined body of
 340   /// a function. Construct DIE to represent this concrete inlined copy
 341   /// of the function.
 342   DIE *constructInlinedScopeDIE(DbgScope *Scope);
 343
 344   /// constructVariableDIE - Construct a DIE for the given DbgVariable.
 345   DIE *constructVariableDIE(DbgVariable *DV, DbgScope *S);
 346
 347   /// constructScopeDIE - Construct a DIE for this scope.
 348   DIE *constructScopeDIE(DbgScope *Scope);
 349
 350   /// EmitSectionLabels - Emit initial Dwarf sections with a label at
 351   /// the start of each one.
 352   void EmitSectionLabels();
 353
 354   /// emitDIE - Recusively Emits a debug information entry.
 355   ///
 356   void emitDIE(DIE *Die);
 357
 358   /// computeSizeAndOffset - Compute the size and offset of a DIE.
 359   ///
 360   unsigned computeSizeAndOffset(DIE *Die, unsigned Offset, bool Last);
 361
 362   /// computeSizeAndOffsets - Compute the size and offset of all the DIEs.
 363   ///
 364   void computeSizeAndOffsets();
 365
 366   /// EmitDebugInfo - Emit the debug info section.
 367   ///
 368   void emitDebugInfo();
 369
 370   /// emitAbbreviations - Emit the abbreviation section.
 371   ///
 372   void emitAbbreviations() const;
 373
 374   /// emitEndOfLineMatrix - Emit the last address of the section and the end of
 375   /// the line matrix.
 376   ///
 377   void emitEndOfLineMatrix(unsigned SectionEnd);
 378
 379   /// emitDebugPubNames - Emit visible names into a debug pubnames section.
 380   ///
 381   void emitDebugPubNames();
 382
 383   /// emitDebugPubTypes - Emit visible types into a debug pubtypes section.
 384   ///
 385   void emitDebugPubTypes();
 386
 387   /// emitDebugStr - Emit visible names into a debug str section.
 388   ///
 389   void emitDebugStr();
 390
 391   /// emitDebugLoc - Emit visible names into a debug loc section.
 392   ///
 393   void emitDebugLoc();
 394
 395   /// EmitDebugARanges - Emit visible names into a debug aranges section.
 396   ///
 397   void EmitDebugARanges();
 398
 399   /// emitDebugRanges - Emit visible names into a debug ranges section.
 400   ///
 401   void emitDebugRanges();
 402
 403   /// emitDebugMacInfo - Emit visible names into a debug macinfo section.
 404   ///
 405   void emitDebugMacInfo();
 406
 407   /// emitDebugInlineInfo - Emit inline info using following format.
 408   /// Section Header:
 409   /// 1. length of section
 410   /// 2. Dwarf version number
 411   /// 3. address size.
 412   ///
 413   /// Entries (one "entry" for each function that was inlined):
 414   ///
 415   /// 1. offset into __debug_str section for MIPS linkage name, if exists;
 416   ///   otherwise offset into __debug_str for regular function name.
 417   /// 2. offset into __debug_str section for regular function name.
 418   /// 3. an unsigned LEB128 number indicating the number of distinct inlining
 419   /// instances for the function.
 420   ///
 421   /// The rest of the entry consists of a {die_offset, low_pc}  pair for each
 422   /// inlined instance; the die_offset points to the inlined_subroutine die in
 423   /// the __debug_info section, and the low_pc is the starting address  for the
 424   ///  inlining instance.
 425   void emitDebugInlineInfo();
 426
 427   /// constructCompileUnit - Create new CompileUnit for the given
 428   /// metadata node with tag DW_TAG_compile_unit.
 429   void constructCompileUnit(const MDNode *N);
 430
 431   /// getCompielUnit - Get CompileUnit DIE.
 432   CompileUnit *getCompileUnit(const MDNode *N) const;
 433
 434   /// constructGlobalVariableDIE - Construct global variable DIE.
 435   void constructGlobalVariableDIE(const MDNode *N);
 436
 437   /// construct SubprogramDIE - Construct subprogram DIE.
 438   void constructSubprogramDIE(const MDNode *N);
 439
 440   /// recordSourceLine - Register a source line with debug info. Returns the
 441   /// unique label that was emitted and which provides correspondence to
 442   /// the source line list.
 443   void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
 444                         unsigned Flags);
 445
 446   /// recordVariableFrameIndex - Record a variable's index.
 447   void recordVariableFrameIndex(const DbgVariable *V, int Index);
 448
 449   /// findVariableFrameIndex - Return true if frame index for the variable
 450   /// is found. Update FI to hold value of the index.
 451   bool findVariableFrameIndex(const DbgVariable *V, int *FI);
 452
 453   /// findDbgScope - Find DbgScope for the debug loc attached with an
 454   /// instruction.
 455   DbgScope *findDbgScope(const MachineInstr *MI);
 456
 457   /// identifyScopeMarkers() - Indentify instructions that are marking
 458   /// beginning of or end of a scope.
 459   void identifyScopeMarkers();
 460
 461   /// extractScopeInformation - Scan machine instructions in this function
 462   /// and collect DbgScopes. Return true, if atleast one scope was found.
 463   bool extractScopeInformation();
 464
 465   /// addCurrentFnArgument - If Var is an current function argument that add
 466   /// it in CurrentFnArguments list.
 467   bool addCurrentFnArgument(const MachineFunction *MF,
 468                             DbgVariable *Var, DbgScope *Scope);
 469
 470   /// collectVariableInfo - Populate DbgScope entries with variables' info.
 471   void collectVariableInfo(const MachineFunction *,
 472                            SmallPtrSet<const MDNode *, 16> &ProcessedVars);
 473
 474   /// collectVariableInfoFromMMITable - Collect variable information from
 475   /// side table maintained by MMI.
 476   void collectVariableInfoFromMMITable(const MachineFunction * MF,
 477                                        SmallPtrSet<const MDNode *, 16> &P);
 478
 479   /// requestLabelBeforeInsn - Ensure that a label will be emitted before MI.
 480   void requestLabelBeforeInsn(const MachineInstr *MI) {
 481     LabelsBeforeInsn.insert(std::make_pair(MI, (MCSymbol*)0));
 482   }
 483
 484   /// getLabelBeforeInsn - Return Label preceding the instruction.
 485   const MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
 486
 487   /// requestLabelAfterInsn - Ensure that a label will be emitted after MI.
 488   void requestLabelAfterInsn(const MachineInstr *MI) {
 489     LabelsAfterInsn.insert(std::make_pair(MI, (MCSymbol*)0));
 490   }
 491
 492   /// getLabelAfterInsn - Return Label immediately following the instruction.
 493   const MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
 494
 495 public:
 496   //===--------------------------------------------------------------------===//
 497   // Main entry points.
 498   //
 499   DwarfDebug(AsmPrinter *A, Module *M);
 500   ~DwarfDebug();
 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   /// createSubprogramDIE - Create new DIE using SP.
 530   DIE *createSubprogramDIE(DISubprogram SP);
 531 };
 532 } // End of namespace llvm
 533
 534 #endif