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/IR/Metadata.h"
  18 #include "llvm/Support/Allocator.h"
  19 #include <map>
  20 #include <memory>
  21 #include <utility>
  22
  23 namespace llvm {
  24
  25 class AsmPrinter;
  26 class DbgEntity;
  27 class DbgVariable;
  28 class DbgLabel;
  29 class DwarfCompileUnit;
  30 class DwarfUnit;
  31 class LexicalScope;
  32 class MCSection;
  33
  34 // Data structure to hold a range for range lists.
  35 struct RangeSpan {
  36   const MCSymbol *Begin;
  37   const MCSymbol *End;
  38 };
  39
  40 class RangeSpanList {
  41 private:
  42   // Index for locating within the debug_range section this particular span.
  43   MCSymbol *RangeSym;
  44   const DwarfCompileUnit *CU;
  45   // List of ranges.
  46   SmallVector<RangeSpan, 2> Ranges;
  47
  48 public:
  49   RangeSpanList(MCSymbol *Sym, const DwarfCompileUnit &CU,
  50                 SmallVector<RangeSpan, 2> Ranges)
  51       : RangeSym(Sym), CU(&CU), Ranges(std::move(Ranges)) {}
  52   MCSymbol *getSym() const { return RangeSym; }
  53   const DwarfCompileUnit &getCU() const { return *CU; }
  54   const SmallVectorImpl<RangeSpan> &getRanges() const { return Ranges; }
  55 };
  56
  57 class DwarfFile {
  58   // Target of Dwarf emission, used for sizing of abbreviations.
  59   AsmPrinter *Asm;
  60
  61   BumpPtrAllocator AbbrevAllocator;
  62
  63   // Used to uniquely define abbreviations.
  64   DIEAbbrevSet Abbrevs;
  65
  66   // A pointer to all units in the section.
  67   SmallVector<std::unique_ptr<DwarfCompileUnit>, 1> CUs;
  68
  69   DwarfStringPool StrPool;
  70
  71   // List of range lists for a given compile unit, separate from the ranges for
  72   // the CU itself.
  73   SmallVector<RangeSpanList, 1> CURangeLists;
  74
  75   /// DWARF v5: The symbol that designates the start of the contribution to
  76   /// the string offsets table. The contribution is shared by all units.
  77   MCSymbol *StringOffsetsStartSym = nullptr;
  78
  79   /// DWARF v5: The symbol that designates the base of the range list table.
  80   /// The table is shared by all units.
  81   MCSymbol *RnglistsTableBaseSym = nullptr;
  82
  83   /// The variables of a lexical scope.
  84   struct ScopeVars {
  85     /// We need to sort Args by ArgNo and check for duplicates. This could also
  86     /// be implemented as a list or vector + std::lower_bound().
  87     std::map<unsigned, DbgVariable *> Args;
  88     SmallVector<DbgVariable *, 8> Locals;
  89   };
  90   /// Collection of DbgVariables of each lexical scope.
  91   DenseMap<LexicalScope *, ScopeVars> ScopeVariables;
  92
  93   /// Collection of DbgLabels of each lexical scope.
  94   using LabelList = SmallVector<DbgLabel *, 4>;
  95   DenseMap<LexicalScope *, LabelList> ScopeLabels;
  96
  97   // Collection of abstract subprogram DIEs.
  98   DenseMap<const MDNode *, DIE *> AbstractSPDies;
  99   DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities;
 100
 101   /// Maps MDNodes for type system with the corresponding DIEs. These DIEs can
 102   /// be shared across CUs, that is why we keep the map here instead
 103   /// of in DwarfCompileUnit.
 104   DenseMap<const MDNode *, DIE *> DITypeNodeToDieMap;
 105
 106 public:
 107   DwarfFile(AsmPrinter *AP, StringRef Pref, BumpPtrAllocator &DA);
 108
 109   const SmallVectorImpl<std::unique_ptr<DwarfCompileUnit>> &getUnits() {
 110     return CUs;
 111   }
 112
 113   std::pair<uint32_t, RangeSpanList *> addRange(const DwarfCompileUnit &CU,
 114                                                 SmallVector<RangeSpan, 2> R);
 115
 116   /// getRangeLists - Get the vector of range lists.
 117   const SmallVectorImpl<RangeSpanList> &getRangeLists() const {
 118     return CURangeLists;
 119   }
 120
 121   /// Compute the size and offset of a DIE given an incoming Offset.
 122   unsigned computeSizeAndOffset(DIE &Die, unsigned Offset);
 123
 124   /// Compute the size and offset of all the DIEs.
 125   void computeSizeAndOffsets();
 126
 127   /// Compute the size and offset of all the DIEs in the given unit.
 128   /// \returns The size of the root DIE.
 129   unsigned computeSizeAndOffsetsForUnit(DwarfUnit *TheU);
 130
 131   /// Add a unit to the list of CUs.
 132   void addUnit(std::unique_ptr<DwarfCompileUnit> U);
 133
 134   /// Emit all of the units to the section listed with the given
 135   /// abbreviation section.
 136   void emitUnits(bool UseOffsets);
 137
 138   /// Emit the given unit to its section.
 139   void emitUnit(DwarfUnit *TheU, bool UseOffsets);
 140
 141   /// Emit a set of abbreviations to the specific section.
 142   void emitAbbrevs(MCSection *);
 143
 144   /// Emit all of the strings to the section given. If OffsetSection is
 145   /// non-null, emit a table of string offsets to it. If UseRelativeOffsets
 146   /// is false, emit absolute offsets to the strings. Otherwise, emit
 147   /// relocatable references to the strings if they are supported by the target.
 148   void emitStrings(MCSection *StrSection, MCSection *OffsetSection = nullptr,
 149                    bool UseRelativeOffsets = false);
 150
 151   /// Returns the string pool.
 152   DwarfStringPool &getStringPool() { return StrPool; }
 153
 154   MCSymbol *getStringOffsetsStartSym() const { return StringOffsetsStartSym; }
 155   void setStringOffsetsStartSym(MCSymbol *Sym) { StringOffsetsStartSym = Sym; }
 156
 157   MCSymbol *getRnglistsTableBaseSym() const { return RnglistsTableBaseSym; }
 158   void setRnglistsTableBaseSym(MCSymbol *Sym) { RnglistsTableBaseSym = Sym; }
 159
 160   /// \returns false if the variable was merged with a previous one.
 161   bool addScopeVariable(LexicalScope *LS, DbgVariable *Var);
 162
 163   void addScopeLabel(LexicalScope *LS, DbgLabel *Label);
 164
 165   DenseMap<LexicalScope *, ScopeVars> &getScopeVariables() {
 166     return ScopeVariables;
 167   }
 168
 169   DenseMap<LexicalScope *, LabelList> &getScopeLabels() {
 170     return ScopeLabels;
 171   }
 172
 173   DenseMap<const MDNode *, DIE *> &getAbstractSPDies() {
 174     return AbstractSPDies;
 175   }
 176
 177   DenseMap<const DINode *, std::unique_ptr<DbgEntity>> &getAbstractEntities() {
 178     return AbstractEntities;
 179   }
 180
 181   void insertDIE(const MDNode *TypeMD, DIE *Die) {
 182     DITypeNodeToDieMap.insert(std::make_pair(TypeMD, Die));
 183   }
 184
 185   DIE *getDIE(const MDNode *TypeMD) {
 186     return DITypeNodeToDieMap.lookup(TypeMD);
 187   }
 188 };
 189
 190 } // end namespace llvm
 191
 192 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFFILE_H