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/DIE.h"
  26 #include "llvm/CodeGen/LexicalScopes.h"
  27 #include "llvm/IR/DebugInfoMetadata.h"
  28 #include "llvm/Support/Casting.h"
  29 #include <algorithm>
  30 #include <cassert>
  31 #include <cstdint>
  32 #include <memory>
  33
  34 namespace llvm {
  35
  36 class AsmPrinter;
  37 class DwarfFile;
  38 class GlobalVariable;
  39 class MCExpr;
  40 class MCSymbol;
  41 class MDNode;
  42
  43 class DwarfCompileUnit final : public DwarfUnit {
  44   /// A numeric ID unique among all CUs in the module
  45   unsigned UniqueID;
  46   bool HasRangeLists = false;
  47
  48   /// The attribute index of DW_AT_stmt_list in the compile unit DIE, avoiding
  49   /// the need to search for it in applyStmtList.
  50   DIE::value_iterator StmtListValue;
  51
  52   /// Skeleton unit associated with this unit.
  53   DwarfCompileUnit *Skeleton = nullptr;
  54
  55   /// The start of the unit within its section.
  56   MCSymbol *LabelBegin;
  57
  58   /// The start of the unit macro info within macro section.
  59   MCSymbol *MacroLabelBegin;
  60
  61   using ImportedEntityList = SmallVector<const MDNode *, 8>;
  62   using ImportedEntityMap = DenseMap<const MDNode *, ImportedEntityList>;
  63
  64   ImportedEntityMap ImportedEntities;
  65
  66   /// GlobalNames - A map of globally visible named entities for this unit.
  67   StringMap<const DIE *> GlobalNames;
  68
  69   /// GlobalTypes - A map of globally visible types for this unit.
  70   StringMap<const DIE *> GlobalTypes;
  71
  72   // List of ranges for a given compile unit.
  73   SmallVector<RangeSpan, 2> CURanges;
  74
  75   // The base address of this unit, if any. Used for relative references in
  76   // ranges/locs.
  77   const MCSymbol *BaseAddress = nullptr;
  78
  79   DenseMap<const MDNode *, DIE *> AbstractSPDies;
  80   DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities;
  81
  82   /// DWO ID for correlating skeleton and split units.
  83   uint64_t DWOId = 0;
  84
  85   /// Construct a DIE for the given DbgVariable without initializing the
  86   /// DbgVariable's DIE reference.
  87   DIE *constructVariableDIEImpl(const DbgVariable &DV, bool Abstract);
  88
  89   bool isDwoUnit() const override;
  90
  91   DenseMap<const MDNode *, DIE *> &getAbstractSPDies() {
  92     if (isDwoUnit() && !DD->shareAcrossDWOCUs())
  93       return AbstractSPDies;
  94     return DU->getAbstractSPDies();
  95   }
  96
  97   DenseMap<const DINode *, std::unique_ptr<DbgEntity>> &getAbstractEntities() {
  98     if (isDwoUnit() && !DD->shareAcrossDWOCUs())
  99       return AbstractEntities;
 100     return DU->getAbstractEntities();
 101   }
 102
 103 public:
 104   DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A,
 105                    DwarfDebug *DW, DwarfFile *DWU);
 106
 107   bool hasRangeLists() const { return HasRangeLists; }
 108   unsigned getUniqueID() const { return UniqueID; }
 109
 110   DwarfCompileUnit *getSkeleton() const {
 111     return Skeleton;
 112   }
 113
 114   bool includeMinimalInlineScopes() const;
 115
 116   void initStmtList();
 117
 118   /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE.
 119   void applyStmtList(DIE &D);
 120
 121   /// A pair of GlobalVariable and DIExpression.
 122   struct GlobalExpr {
 123     const GlobalVariable *Var;
 124     const DIExpression *Expr;
 125   };
 126
 127   /// Get or create global variable DIE.
 128   DIE *
 129   getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV,
 130                                ArrayRef<GlobalExpr> GlobalExprs);
 131
 132   /// addLabelAddress - Add a dwarf label attribute data and value using
 133   /// either DW_FORM_addr or DW_FORM_GNU_addr_index.
 134   void addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
 135                        const MCSymbol *Label);
 136
 137   /// addLocalLabelAddress - Add a dwarf label attribute data and value using
 138   /// DW_FORM_addr only.
 139   void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute,
 140                             const MCSymbol *Label);
 141
 142   DwarfCompileUnit &getCU() override { return *this; }
 143
 144   unsigned getOrCreateSourceID(const DIFile *File) override;
 145
 146   void addImportedEntity(const DIImportedEntity* IE) {
 147     DIScope *Scope = IE->getScope();
 148     assert(Scope && "Invalid Scope encoding!");
 149     if (!isa<DILocalScope>(Scope))
 150       // No need to add imported enities that are not local declaration.
 151       return;
 152
 153     auto *LocalScope = cast<DILocalScope>(Scope)->getNonLexicalBlockFileScope();
 154     ImportedEntities[LocalScope].push_back(IE);
 155   }
 156
 157   /// addRange - Add an address range to the list of ranges for this unit.
 158   void addRange(RangeSpan Range);
 159
 160   void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End);
 161
 162   /// Find DIE for the given subprogram and attach appropriate
 163   /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
 164   /// variables in this scope then create and insert DIEs for these
 165   /// variables.
 166   DIE &updateSubprogramScopeDIE(const DISubprogram *SP);
 167
 168   void constructScopeDIE(LexicalScope *Scope,
 169                          SmallVectorImpl<DIE *> &FinalChildren);
 170
 171   /// A helper function to construct a RangeSpanList for a given
 172   /// lexical scope.
 173   void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range);
 174
 175   void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges);
 176
 177   void attachRangesOrLowHighPC(DIE &D,
 178                                const SmallVectorImpl<InsnRange> &Ranges);
 179
 180   /// This scope represents inlined body of a function. Construct
 181   /// DIE to represent this concrete inlined copy of the function.
 182   DIE *constructInlinedScopeDIE(LexicalScope *Scope);
 183
 184   /// Construct new DW_TAG_lexical_block for this scope and
 185   /// attach DW_AT_low_pc/DW_AT_high_pc labels.
 186   DIE *constructLexicalScopeDIE(LexicalScope *Scope);
 187
 188   /// constructVariableDIE - Construct a DIE for the given DbgVariable.
 189   DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false);
 190
 191   DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope,
 192                             DIE *&ObjectPointer);
 193
 194   /// Construct a DIE for the given DbgLabel.
 195   DIE *constructLabelDIE(DbgLabel &DL, const LexicalScope &Scope);
 196
 197   /// A helper function to create children of a Scope DIE.
 198   DIE *createScopeChildrenDIE(LexicalScope *Scope,
 199                               SmallVectorImpl<DIE *> &Children,
 200                               bool *HasNonScopeChildren = nullptr);
 201
 202   /// Construct a DIE for this subprogram scope.
 203   DIE &constructSubprogramScopeDIE(const DISubprogram *Sub,
 204                                    LexicalScope *Scope);
 205
 206   DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE);
 207
 208   void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
 209
 210   /// Construct a call site entry DIE describing a call within \p Scope to a
 211   /// callee described by \p CalleeSP. \p IsTail specifies whether the call is
 212   /// a tail call. \p PCOffset must be non-zero for non-tail calls or be the
 213   /// function-local offset to PC value after the call instruction.
 214   DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, const DISubprogram &CalleeSP,
 215                                  bool IsTail, const MCExpr *PCOffset);
 216
 217   /// Construct import_module DIE.
 218   DIE *constructImportedEntityDIE(const DIImportedEntity *Module);
 219
 220   void finishSubprogramDefinition(const DISubprogram *SP);
 221   void finishEntityDefinition(const DbgEntity *Entity);
 222
 223   /// Find abstract variable associated with Var.
 224   using InlinedEntity = DbgValueHistoryMap::InlinedEntity;
 225   DbgEntity *getExistingAbstractEntity(const DINode *Node);
 226   void createAbstractEntity(const DINode *Node, LexicalScope *Scope);
 227
 228   /// Set the skeleton unit associated with this unit.
 229   void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; }
 230
 231   unsigned getHeaderSize() const override {
 232     // DWARF v5 added the DWO ID to the header for split/skeleton units.
 233     unsigned DWOIdSize =
 234         DD->getDwarfVersion() >= 5 && DD->useSplitDwarf() ? sizeof(uint64_t)
 235                                                           : 0;
 236     return DwarfUnit::getHeaderSize() + DWOIdSize;
 237   }
 238   unsigned getLength() {
 239     return sizeof(uint32_t) + // Length field
 240         getHeaderSize() + getUnitDie().getSize();
 241   }
 242
 243   void emitHeader(bool UseOffsets) override;
 244
 245   /// Add the DW_AT_addr_base attribute to the unit DIE.
 246   void addAddrTableBase();
 247
 248   MCSymbol *getLabelBegin() const {
 249     assert(getSection());
 250     return LabelBegin;
 251   }
 252
 253   MCSymbol *getMacroLabelBegin() const {
 254     return MacroLabelBegin;
 255   }
 256
 257   /// Add a new global name to the compile unit.
 258   void addGlobalName(StringRef Name, const DIE &Die,
 259                      const DIScope *Context) override;
 260
 261   /// Add a new global name present in a type unit to this compile unit.
 262   void addGlobalNameForTypeUnit(StringRef Name, const DIScope *Context);
 263
 264   /// Add a new global type to the compile unit.
 265   void addGlobalType(const DIType *Ty, const DIE &Die,
 266                      const DIScope *Context) override;
 267
 268   /// Add a new global type present in a type unit to this compile unit.
 269   void addGlobalTypeUnitType(const DIType *Ty, const DIScope *Context);
 270
 271   const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; }
 272   const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; }
 273
 274   /// Add DW_AT_location attribute for a DbgVariable based on provided
 275   /// MachineLocation.
 276   void addVariableAddress(const DbgVariable &DV, DIE &Die,
 277                           MachineLocation Location);
 278   /// Add an address attribute to a die based on the location provided.
 279   void addAddress(DIE &Die, dwarf::Attribute Attribute,
 280                   const MachineLocation &Location);
 281
 282   /// Start with the address based on the location provided, and generate the
 283   /// DWARF information necessary to find the actual variable (navigating the
 284   /// extra location information encoded in the type) based on the starting
 285   /// location.  Add the DWARF information to the die.
 286   void addComplexAddress(const DbgVariable &DV, DIE &Die,
 287                          dwarf::Attribute Attribute,
 288                          const MachineLocation &Location);
 289
 290   /// Add a Dwarf loclistptr attribute data and value.
 291   void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index);
 292   void applyVariableAttributes(const DbgVariable &Var, DIE &VariableDie);
 293
 294   /// Add a Dwarf expression attribute data and value.
 295   void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr);
 296
 297   /// Add an attribute containing an address expression to \p Die.
 298   void addAddressExpr(DIE &Die, dwarf::Attribute Attribute, const MCExpr *Expr);
 299
 300   void applySubprogramAttributesToDefinition(const DISubprogram *SP,
 301                                              DIE &SPDie);
 302
 303   void applyLabelAttributes(const DbgLabel &Label, DIE &LabelDie);
 304
 305   /// getRanges - Get the list of ranges for this unit.
 306   const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; }
 307   SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); }
 308
 309   void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; }
 310   const MCSymbol *getBaseAddress() const { return BaseAddress; }
 311
 312   uint64_t getDWOId() const { return DWOId; }
 313   void setDWOId(uint64_t DwoId) { DWOId = DwoId; }
 314
 315   bool hasDwarfPubSections() const;
 316 };
 317
 318 } // end namespace llvm
 319
 320 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H