llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h

   1 //===- llvm/CodeGen/DwarfCompileUnit.h - Dwarf Compile Unit -----*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains support for writing dwarf compile unit.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
  14 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
  15
  16 #include "DwarfDebug.h"
  17 #include "DwarfUnit.h"
  18 #include "llvm/ADT/ArrayRef.h"
  19 #include "llvm/ADT/DenseMap.h"
  20 #include "llvm/ADT/SmallVector.h"
  21 #include "llvm/ADT/StringMap.h"
  22 #include "llvm/ADT/StringRef.h"
  23 #include "llvm/BinaryFormat/Dwarf.h"
  24 #include "llvm/CodeGen/DbgEntityHistoryCalculator.h"
  25 #include "llvm/CodeGen/LexicalScopes.h"
  26 #include "llvm/IR/DebugInfoMetadata.h"
  27 #include "llvm/Support/Casting.h"
  28 #include <cstdint>
  29 #include <memory>
  30
  31 namespace llvm {
  32
  33 class AsmPrinter;
  34 class DIE;
  35 class DIELoc;
  36 class DIEValueList;
  37 class DwarfFile;
  38 class GlobalVariable;
  39 class MCExpr;
  40 class MCSymbol;
  41 class MDNode;
  42
  43 enum class UnitKind { Skeleton, Full };
  44
  45 class DwarfCompileUnit final : public DwarfUnit {
  46   bool HasRangeLists = false;
  47
  48   /// The start of the unit line section, this is also
  49   /// reused in appyStmtList.
  50   MCSymbol *LineTableStartSym;
  51
  52   /// Skeleton unit associated with this unit.
  53   DwarfCompileUnit *Skeleton = nullptr;
  54
  55   /// The start of the unit macro info within macro section.
  56   MCSymbol *MacroLabelBegin;
  57
  58   /// GlobalNames - A map of globally visible named entities for this unit.
  59   StringMap<const DIE *> GlobalNames;
  60
  61   /// GlobalTypes - A map of globally visible types for this unit.
  62   StringMap<const DIE *> GlobalTypes;
  63
  64   // List of ranges for a given compile unit.
  65   SmallVector<RangeSpan, 2> CURanges;
  66
  67   // The base address of this unit, if any. Used for relative references in
  68   // ranges/locs.
  69   const MCSymbol *BaseAddress = nullptr;
  70
  71   using MDNodeSetVector =
  72       SetVector<const MDNode *, SmallVector<const MDNode *, 4>,
  73                 SmallPtrSet<const MDNode *, 4>>;
  74
  75   // List of entities (either static locals, types or imports) that
  76   // belong to subprograms within this CU.
  77   MDNodeSetVector DeferredLocalDecls;
  78
  79   // List of concrete lexical block scopes belong to subprograms within this CU.
  80   DenseMap<const DILocalScope *, DIE *> LexicalBlockDIEs;
  81
  82   // List of abstract local scopes (either DISubprogram or DILexicalBlock).
  83   DenseMap<const DILocalScope *, DIE *> AbstractLocalScopeDIEs;
  84
  85   DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities;
  86
  87   /// DWO ID for correlating skeleton and split units.
  88   uint64_t DWOId = 0;
  89
  90   const DIFile *LastFile = nullptr;
  91   unsigned LastFileID;
  92
  93   /// \anchor applyConcreteDbgVariableAttribute
  94   /// \name applyConcreteDbgVariableAttribute
  95   /// Overload set which applies attributes to \c VariableDie based on
  96   /// the active variant of \c DV, which is passed as the first argument.
  97   ///@{
  98
  99   /// See \ref applyConcreteDbgVariableAttribute
 100   void applyConcreteDbgVariableAttributes(const Loc::Single &Single,
 101                                           const DbgVariable &DV,
 102                                           DIE &VariableDie);
 103   /// See \ref applyConcreteDbgVariableAttribute
 104   void applyConcreteDbgVariableAttributes(const Loc::Multi &Multi,
 105                                           const DbgVariable &DV,
 106                                           DIE &VariableDie);
 107   /// See \ref applyConcreteDbgVariableAttribute
 108   void applyConcreteDbgVariableAttributes(const Loc::MMI &MMI,
 109                                           const DbgVariable &DV,
 110                                           DIE &VariableDie);
 111   /// See \ref applyConcreteDbgVariableAttribute
 112   void applyConcreteDbgVariableAttributes(const Loc::EntryValue &EntryValue,
 113                                           const DbgVariable &DV,
 114                                           DIE &VariableDie);
 115   /// See \ref applyConcreteDbgVariableAttribute
 116   void applyConcreteDbgVariableAttributes(const std::monostate &,
 117                                           const DbgVariable &DV,
 118                                           DIE &VariableDie);
 119
 120   ///@}
 121
 122   bool isDwoUnit() const override;
 123
 124   DenseMap<const DILocalScope *, DIE *> &getAbstractScopeDIEs() {
 125     if (isDwoUnit() && !DD->shareAcrossDWOCUs())
 126       return AbstractLocalScopeDIEs;
 127     return DU->getAbstractScopeDIEs();
 128   }
 129
 130   DenseMap<const DINode *, std::unique_ptr<DbgEntity>> &getAbstractEntities() {
 131     if (isDwoUnit() && !DD->shareAcrossDWOCUs())
 132       return AbstractEntities;
 133     return DU->getAbstractEntities();
 134   }
 135
 136   void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) override;
 137
 138   /// Add info for Wasm-global-based relocation.
 139   void addWasmRelocBaseGlobal(DIELoc *Loc, StringRef GlobalName,
 140                               uint64_t GlobalIndex);
 141
 142 public:
 143   DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A,
 144                    DwarfDebug *DW, DwarfFile *DWU,
 145                    UnitKind Kind = UnitKind::Full);
 146
 147   bool hasRangeLists() const { return HasRangeLists; }
 148
 149   DwarfCompileUnit *getSkeleton() const {
 150     return Skeleton;
 151   }
 152
 153   bool includeMinimalInlineScopes() const;
 154
 155   void initStmtList();
 156
 157   /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE.
 158   void applyStmtList(DIE &D);
 159
 160   /// Get line table start symbol for this unit.
 161   MCSymbol *getLineTableStartSym() const { return LineTableStartSym; }
 162
 163   /// A pair of GlobalVariable and DIExpression.
 164   struct GlobalExpr {
 165     const GlobalVariable *Var;
 166     const DIExpression *Expr;
 167   };
 168
 169   struct BaseTypeRef {
 170     BaseTypeRef(unsigned BitSize, dwarf::TypeKind Encoding) :
 171       BitSize(BitSize), Encoding(Encoding) {}
 172     unsigned BitSize;
 173     dwarf::TypeKind Encoding;
 174     DIE *Die = nullptr;
 175   };
 176
 177   std::vector<BaseTypeRef> ExprRefedBaseTypes;
 178
 179   /// Get or create global variable DIE.
 180   DIE *
 181   getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV,
 182                                ArrayRef<GlobalExpr> GlobalExprs);
 183
 184   DIE *getOrCreateCommonBlock(const DICommonBlock *CB,
 185                               ArrayRef<GlobalExpr> GlobalExprs);
 186
 187   void addLocationAttribute(DIE *ToDIE, const DIGlobalVariable *GV,
 188                             ArrayRef<GlobalExpr> GlobalExprs);
 189
 190   /// addLabelAddress - Add a dwarf label attribute data and value using
 191   /// either DW_FORM_addr or DW_FORM_GNU_addr_index.
 192   void addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
 193                        const MCSymbol *Label);
 194
 195   /// addLocalLabelAddress - Add a dwarf label attribute data and value using
 196   /// DW_FORM_addr only.
 197   void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute,
 198                             const MCSymbol *Label);
 199
 200   DwarfCompileUnit &getCU() override { return *this; }
 201
 202   unsigned getOrCreateSourceID(const DIFile *File) override;
 203
 204   /// addRange - Add an address range to the list of ranges for this unit.
 205   void addRange(RangeSpan Range);
 206
 207   void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End);
 208
 209   /// Find DIE for the given subprogram and attach appropriate
 210   /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
 211   /// variables in this scope then create and insert DIEs for these
 212   /// variables.
 213   DIE &updateSubprogramScopeDIE(const DISubprogram *SP);
 214
 215   void constructScopeDIE(LexicalScope *Scope, DIE &ParentScopeDIE);
 216
 217   /// A helper function to construct a RangeSpanList for a given
 218   /// lexical scope.
 219   void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range);
 220
 221   void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges);
 222
 223   void attachRangesOrLowHighPC(DIE &D,
 224                                const SmallVectorImpl<InsnRange> &Ranges);
 225
 226   /// This scope represents an inlined body of a function. Construct a
 227   /// DIE to represent this concrete inlined copy of the function.
 228   DIE *constructInlinedScopeDIE(LexicalScope *Scope, DIE &ParentScopeDIE);
 229
 230   /// Construct new DW_TAG_lexical_block for this scope and
 231   /// attach DW_AT_low_pc/DW_AT_high_pc labels.
 232   DIE *constructLexicalScopeDIE(LexicalScope *Scope);
 233
 234   /// Get a DIE for the given DILexicalBlock.
 235   /// Note that this function assumes that the DIE has been already created
 236   /// and it's an error, if it hasn't.
 237   DIE *getLexicalBlockDIE(const DILexicalBlock *LB);
 238
 239   /// Construct a DIE for the given DbgVariable.
 240   DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false);
 241
 242   /// Convenience overload which writes the DIE pointer into an out variable
 243   /// ObjectPointer in addition to returning it.
 244   DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope,
 245                             DIE *&ObjectPointer);
 246
 247   /// Construct a DIE for the given DbgLabel.
 248   DIE *constructLabelDIE(DbgLabel &DL, const LexicalScope &Scope);
 249
 250   void createBaseTypeDIEs();
 251
 252   /// Construct a DIE for a given scope.
 253   /// This instance of 'getOrCreateContextDIE()' can handle DILocalScope.
 254   DIE *getOrCreateContextDIE(const DIScope *Ty) override;
 255
 256   /// Construct a DIE for this subprogram scope.
 257   DIE &constructSubprogramScopeDIE(const DISubprogram *Sub,
 258                                    LexicalScope *Scope);
 259
 260   DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE);
 261
 262   void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
 263
 264   /// Whether to use the GNU analog for a DWARF5 tag, attribute, or location
 265   /// atom. Only applicable when emitting otherwise DWARF4-compliant debug info.
 266   bool useGNUAnalogForDwarf5Feature() const;
 267
 268   /// This takes a DWARF 5 tag and returns it or a GNU analog.
 269   dwarf::Tag getDwarf5OrGNUTag(dwarf::Tag Tag) const;
 270
 271   /// This takes a DWARF 5 attribute and returns it or a GNU analog.
 272   dwarf::Attribute getDwarf5OrGNUAttr(dwarf::Attribute Attr) const;
 273
 274   /// This takes a DWARF 5 location atom and either returns it or a GNU analog.
 275   dwarf::LocationAtom getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const;
 276
 277   /// Construct a call site entry DIE describing a call within \p Scope to a
 278   /// callee described by \p CalleeSP.
 279   /// \p IsTail specifies whether the call is a tail call.
 280   /// \p PCAddr points to the PC value after the call instruction.
 281   /// \p CallAddr points to the PC value at the call instruction (or is null).
 282   /// \p CallReg is a register location for an indirect call. For direct calls
 283   /// the \p CallReg is set to 0.
 284   DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, const DISubprogram *CalleeSP,
 285                                  bool IsTail, const MCSymbol *PCAddr,
 286                                  const MCSymbol *CallAddr, unsigned CallReg);
 287   /// Construct call site parameter DIEs for the \p CallSiteDIE. The \p Params
 288   /// were collected by the \ref collectCallSiteParameters.
 289   /// Note: The order of parameters does not matter, since debuggers recognize
 290   ///       call site parameters by the DW_AT_location attribute.
 291   void constructCallSiteParmEntryDIEs(DIE &CallSiteDIE,
 292                                       SmallVector<DbgCallSiteParam, 4> &Params);
 293
 294   /// Get or create a DIE for an imported entity.
 295   DIE *getOrCreateImportedEntityDIE(const DIImportedEntity *IE);
 296   DIE *constructImportedEntityDIE(const DIImportedEntity *IE);
 297
 298   void finishSubprogramDefinition(const DISubprogram *SP);
 299   void finishEntityDefinition(const DbgEntity *Entity);
 300
 301   /// Find abstract variable associated with Var.
 302   using InlinedEntity = DbgValueHistoryMap::InlinedEntity;
 303   DbgEntity *getExistingAbstractEntity(const DINode *Node);
 304   void createAbstractEntity(const DINode *Node, LexicalScope *Scope);
 305
 306   /// Set the skeleton unit associated with this unit.
 307   void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; }
 308
 309   unsigned getHeaderSize() const override {
 310     // DWARF v5 added the DWO ID to the header for split/skeleton units.
 311     unsigned DWOIdSize =
 312         DD->getDwarfVersion() >= 5 && DD->useSplitDwarf() ? sizeof(uint64_t)
 313                                                           : 0;
 314     return DwarfUnit::getHeaderSize() + DWOIdSize;
 315   }
 316   unsigned getLength() {
 317     return Asm->getUnitLengthFieldByteSize() + // Length field
 318            getHeaderSize() + getUnitDie().getSize();
 319   }
 320
 321   void emitHeader(bool UseOffsets) override;
 322
 323   /// Add the DW_AT_addr_base attribute to the unit DIE.
 324   void addAddrTableBase();
 325
 326   MCSymbol *getMacroLabelBegin() const {
 327     return MacroLabelBegin;
 328   }
 329
 330   /// Add a new global name to the compile unit.
 331   void addGlobalName(StringRef Name, const DIE &Die,
 332                      const DIScope *Context) override;
 333
 334   /// Add a new global name present in a type unit to this compile unit.
 335   void addGlobalNameForTypeUnit(StringRef Name, const DIScope *Context);
 336
 337   /// Add a new global type to the compile unit.
 338   void addGlobalTypeImpl(const DIType *Ty, const DIE &Die,
 339                          const DIScope *Context) override;
 340
 341   /// Add a new global type present in a type unit to this compile unit.
 342   void addGlobalTypeUnitType(const DIType *Ty, const DIScope *Context);
 343
 344   const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; }
 345   const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; }
 346
 347   /// Add DW_AT_location attribute for a DbgVariable based on provided
 348   /// MachineLocation.
 349   void addVariableAddress(const DbgVariable &DV, DIE &Die,
 350                           MachineLocation Location);
 351   /// Add an address attribute to a die based on the location provided.
 352   void addAddress(DIE &Die, dwarf::Attribute Attribute,
 353                   const MachineLocation &Location);
 354
 355   /// Start with the address based on the location provided, and generate the
 356   /// DWARF information necessary to find the actual variable (navigating the
 357   /// extra location information encoded in the type) based on the starting
 358   /// location.  Add the DWARF information to the die.
 359   void addComplexAddress(const DIExpression *DIExpr, DIE &Die,
 360                          dwarf::Attribute Attribute,
 361                          const MachineLocation &Location);
 362
 363   /// Add a Dwarf loclistptr attribute data and value.
 364   void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index);
 365
 366   /// Add attributes to \p Var which reflect the common attributes of \p
 367   /// VariableDie, namely those which are not dependant on the active variant.
 368   void applyCommonDbgVariableAttributes(const DbgVariable &Var,
 369                                         DIE &VariableDie);
 370
 371   /// Add a Dwarf expression attribute data and value.
 372   void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr);
 373
 374   void applySubprogramAttributesToDefinition(const DISubprogram *SP,
 375                                              DIE &SPDie);
 376
 377   void applyLabelAttributes(const DbgLabel &Label, DIE &LabelDie);
 378
 379   /// getRanges - Get the list of ranges for this unit.
 380   const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; }
 381   SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); }
 382
 383   void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; }
 384   const MCSymbol *getBaseAddress() const { return BaseAddress; }
 385
 386   uint64_t getDWOId() const { return DWOId; }
 387   void setDWOId(uint64_t DwoId) { DWOId = DwoId; }
 388
 389   bool hasDwarfPubSections() const;
 390
 391   void addBaseTypeRef(DIEValueList &Die, int64_t Idx);
 392
 393   MDNodeSetVector &getDeferredLocalDecls() { return DeferredLocalDecls; }
 394 };
 395
 396 } // end namespace llvm
 397
 398 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H