llvm/lib/CodeGen/AsmPrinter/DwarfFile.h

   1 //===- llvm/CodeGen/DwarfFile.h - Dwarf Debug Framework ---------*- 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 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFFILE_H
  10 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFFILE_H
  11
  12 #include "DwarfStringPool.h"
  13 #include "llvm/ADT/DenseMap.h"
  14 #include "llvm/ADT/SmallVector.h"
  15 #include "llvm/ADT/StringRef.h"
  16 #include "llvm/CodeGen/DIE.h"
  17 #include "llvm/Support/Allocator.h"
  18 #include <map>
  19 #include <memory>
  20 #include <utility>
  21
  22 namespace llvm {
  23
  24 class AsmPrinter;
  25 class DbgEntity;
  26 class DbgVariable;
  27 class DbgLabel;
  28 class DINode;
  29 class DwarfCompileUnit;
  30 class DwarfUnit;
  31 class LexicalScope;
  32 class MCSection;
  33 class MDNode;
  34
  35 // Data structure to hold a range for range lists.
  36 struct RangeSpan {
  37   const MCSymbol *Begin;
  38   const MCSymbol *End;
  39 };
  40
  41 struct RangeSpanList {
  42   // Index for locating within the debug_range section this particular span.
  43   MCSymbol *Label;
  44   const DwarfCompileUnit *CU;
  45   // List of ranges.
  46   SmallVector<RangeSpan, 2> Ranges;
  47 };
  48
  49 class DwarfFile {
  50   // Target of Dwarf emission, used for sizing of abbreviations.
  51   AsmPrinter *Asm;
  52
  53   BumpPtrAllocator AbbrevAllocator;
  54
  55   // Used to uniquely define abbreviations.
  56   DIEAbbrevSet Abbrevs;
  57
  58   // A pointer to all units in the section.
  59   SmallVector<std::unique_ptr<DwarfCompileUnit>, 1> CUs;
  60
  61   DwarfStringPool StrPool;
  62
  63   // List of range lists for a given compile unit, separate from the ranges for
  64   // the CU itself.
  65   SmallVector<RangeSpanList, 1> CURangeLists;
  66
  67   /// DWARF v5: The symbol that designates the start of the contribution to
  68   /// the string offsets table. The contribution is shared by all units.
  69   MCSymbol *StringOffsetsStartSym = nullptr;
  70
  71   /// DWARF v5: The symbol that designates the base of the range list table.
  72   /// The table is shared by all units.
  73   MCSymbol *RnglistsTableBaseSym = nullptr;
  74
  75   /// The variables of a lexical scope.
  76   struct ScopeVars {
  77     /// We need to sort Args by ArgNo and check for duplicates. This could also
  78     /// be implemented as a list or vector + std::lower_bound().
  79     std::map<unsigned, DbgVariable *> Args;
  80     SmallVector<DbgVariable *, 8> Locals;
  81   };
  82   /// Collection of DbgVariables of each lexical scope.
  83   DenseMap<LexicalScope *, ScopeVars> ScopeVariables;
  84
  85   /// Collection of DbgLabels of each lexical scope.
  86   using LabelList = SmallVector<DbgLabel *, 4>;
  87   DenseMap<LexicalScope *, LabelList> ScopeLabels;
  88
  89   // Collection of abstract subprogram DIEs.
  90   DenseMap<const MDNode *, DIE *> AbstractSPDies;
  91   DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities;
  92
  93   /// Maps MDNodes for type system with the corresponding DIEs. These DIEs can
  94   /// be shared across CUs, that is why we keep the map here instead
  95   /// of in DwarfCompileUnit.
  96   DenseMap<const MDNode *, DIE *> DITypeNodeToDieMap;
  97
  98 public:
  99   DwarfFile(AsmPrinter *AP, StringRef Pref, BumpPtrAllocator &DA);
 100
 101   const SmallVectorImpl<std::unique_ptr<DwarfCompileUnit>> &getUnits() {
 102     return CUs;
 103   }
 104
 105   std::pair<uint32_t, RangeSpanList *> addRange(const DwarfCompileUnit &CU,
 106                                                 SmallVector<RangeSpan, 2> R);
 107
 108   /// getRangeLists - Get the vector of range lists.
 109   const SmallVectorImpl<RangeSpanList> &getRangeLists() const {
 110     return CURangeLists;
 111   }
 112
 113   /// Compute the size and offset of a DIE given an incoming Offset.
 114   unsigned computeSizeAndOffset(DIE &Die, unsigned Offset);
 115
 116   /// Compute the size and offset of all the DIEs.
 117   void computeSizeAndOffsets();
 118
 119   /// Compute the size and offset of all the DIEs in the given unit.
 120   /// \returns The size of the root DIE.
 121   unsigned computeSizeAndOffsetsForUnit(DwarfUnit *TheU);
 122
 123   /// Add a unit to the list of CUs.
 124   void addUnit(std::unique_ptr<DwarfCompileUnit> U);
 125
 126   /// Emit all of the units to the section listed with the given
 127   /// abbreviation section.
 128   void emitUnits(bool UseOffsets);
 129
 130   /// Emit the given unit to its section.
 131   void emitUnit(DwarfUnit *TheU, bool UseOffsets);
 132
 133   /// Emit a set of abbreviations to the specific section.
 134   void emitAbbrevs(MCSection *);
 135
 136   /// Emit all of the strings to the section given. If OffsetSection is
 137   /// non-null, emit a table of string offsets to it. If UseRelativeOffsets
 138   /// is false, emit absolute offsets to the strings. Otherwise, emit
 139   /// relocatable references to the strings if they are supported by the target.
 140   void emitStrings(MCSection *StrSection, MCSection *OffsetSection = nullptr,
 141                    bool UseRelativeOffsets = false);
 142
 143   /// Returns the string pool.
 144   DwarfStringPool &getStringPool() { return StrPool; }
 145
 146   MCSymbol *getStringOffsetsStartSym() const { return StringOffsetsStartSym; }
 147   void setStringOffsetsStartSym(MCSymbol *Sym) { StringOffsetsStartSym = Sym; }
 148
 149   MCSymbol *getRnglistsTableBaseSym() const { return RnglistsTableBaseSym; }
 150   void setRnglistsTableBaseSym(MCSymbol *Sym) { RnglistsTableBaseSym = Sym; }
 151
 152   /// \returns false if the variable was merged with a previous one.
 153   bool addScopeVariable(LexicalScope *LS, DbgVariable *Var);
 154
 155   void addScopeLabel(LexicalScope *LS, DbgLabel *Label);
 156
 157   DenseMap<LexicalScope *, ScopeVars> &getScopeVariables() {
 158     return ScopeVariables;
 159   }
 160
 161   DenseMap<LexicalScope *, LabelList> &getScopeLabels() {
 162     return ScopeLabels;
 163   }
 164
 165   DenseMap<const MDNode *, DIE *> &getAbstractSPDies() {
 166     return AbstractSPDies;
 167   }
 168
 169   DenseMap<const DINode *, std::unique_ptr<DbgEntity>> &getAbstractEntities() {
 170     return AbstractEntities;
 171   }
 172
 173   void insertDIE(const MDNode *TypeMD, DIE *Die) {
 174     DITypeNodeToDieMap.insert(std::make_pair(TypeMD, Die));
 175   }
 176
 177   DIE *getDIE(const MDNode *TypeMD) {
 178     return DITypeNodeToDieMap.lookup(TypeMD);
 179   }
 180 };
 181
 182 } // end namespace llvm
 183
 184 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFFILE_H