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 DILocalScope;
  30 class DwarfCompileUnit;
  31 class DwarfUnit;
  32 class LexicalScope;
  33 class MCSection;
  34 class MDNode;
  35
  36 // Data structure to hold a range for range lists.
  37 struct RangeSpan {
  38   const MCSymbol *Begin;
  39   const MCSymbol *End;
  40 };
  41
  42 struct RangeSpanList {
  43   // Index for locating within the debug_range section this particular span.
  44   MCSymbol *Label;
  45   const DwarfCompileUnit *CU;
  46   // List of ranges.
  47   SmallVector<RangeSpan, 2> Ranges;
  48 };
  49
  50 class DwarfFile {
  51   // Target of Dwarf emission, used for sizing of abbreviations.
  52   AsmPrinter *Asm;
  53
  54   BumpPtrAllocator AbbrevAllocator;
  55
  56   // Used to uniquely define abbreviations.
  57   DIEAbbrevSet Abbrevs;
  58
  59   // A pointer to all units in the section.
  60   SmallVector<std::unique_ptr<DwarfCompileUnit>, 1> CUs;
  61
  62   DwarfStringPool StrPool;
  63
  64   // List of range lists for a given compile unit, separate from the ranges for
  65   // the CU itself.
  66   SmallVector<RangeSpanList, 1> CURangeLists;
  67
  68   /// DWARF v5: The symbol that designates the start of the contribution to
  69   /// the string offsets table. The contribution is shared by all units.
  70   MCSymbol *StringOffsetsStartSym = nullptr;
  71
  72   /// DWARF v5: The symbol that designates the base of the range list table.
  73   /// The table is shared by all units.
  74   MCSymbol *RnglistsTableBaseSym = nullptr;
  75
  76   /// The variables of a lexical scope.
  77   struct ScopeVars {
  78     /// We need to sort Args by ArgNo and check for duplicates. This could also
  79     /// be implemented as a list or vector + std::lower_bound().
  80     std::map<unsigned, DbgVariable *> Args;
  81     SmallVector<DbgVariable *, 8> Locals;
  82   };
  83   /// Collection of DbgVariables of each lexical scope.
  84   DenseMap<LexicalScope *, ScopeVars> ScopeVariables;
  85
  86   /// Collection of DbgLabels of each lexical scope.
  87   using LabelList = SmallVector<DbgLabel *, 4>;
  88   DenseMap<LexicalScope *, LabelList> ScopeLabels;
  89
  90   // Collection of abstract subprogram DIEs.
  91   DenseMap<const DILocalScope *, DIE *> AbstractLocalScopeDIEs;
  92   DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities;
  93
  94   /// Maps MDNodes for type system with the corresponding DIEs. These DIEs can
  95   /// be shared across CUs, that is why we keep the map here instead
  96   /// of in DwarfCompileUnit.
  97   DenseMap<const MDNode *, DIE *> DITypeNodeToDieMap;
  98
  99 public:
 100   DwarfFile(AsmPrinter *AP, StringRef Pref, BumpPtrAllocator &DA);
 101
 102   const SmallVectorImpl<std::unique_ptr<DwarfCompileUnit>> &getUnits() {
 103     return CUs;
 104   }
 105
 106   std::pair<uint32_t, RangeSpanList *> addRange(const DwarfCompileUnit &CU,
 107                                                 SmallVector<RangeSpan, 2> R);
 108
 109   /// getRangeLists - Get the vector of range lists.
 110   const SmallVectorImpl<RangeSpanList> &getRangeLists() const {
 111     return CURangeLists;
 112   }
 113
 114   /// Compute the size and offset of a DIE given an incoming Offset.
 115   unsigned computeSizeAndOffset(DIE &Die, unsigned Offset);
 116
 117   /// Compute the size and offset of all the DIEs.
 118   void computeSizeAndOffsets();
 119
 120   /// Compute the size and offset of all the DIEs in the given unit.
 121   /// \returns The size of the root DIE.
 122   unsigned computeSizeAndOffsetsForUnit(DwarfUnit *TheU);
 123
 124   /// Add a unit to the list of CUs.
 125   void addUnit(std::unique_ptr<DwarfCompileUnit> U);
 126
 127   /// Emit all of the units to the section listed with the given
 128   /// abbreviation section.
 129   void emitUnits(bool UseOffsets);
 130
 131   /// Emit the given unit to its section.
 132   void emitUnit(DwarfUnit *TheU, bool UseOffsets);
 133
 134   /// Emit a set of abbreviations to the specific section.
 135   void emitAbbrevs(MCSection *);
 136
 137   /// Emit all of the strings to the section given. If OffsetSection is
 138   /// non-null, emit a table of string offsets to it. If UseRelativeOffsets
 139   /// is false, emit absolute offsets to the strings. Otherwise, emit
 140   /// relocatable references to the strings if they are supported by the target.
 141   void emitStrings(MCSection *StrSection, MCSection *OffsetSection = nullptr,
 142                    bool UseRelativeOffsets = false);
 143
 144   /// Returns the string pool.
 145   DwarfStringPool &getStringPool() { return StrPool; }
 146
 147   MCSymbol *getStringOffsetsStartSym() const { return StringOffsetsStartSym; }
 148   void setStringOffsetsStartSym(MCSymbol *Sym) { StringOffsetsStartSym = Sym; }
 149
 150   MCSymbol *getRnglistsTableBaseSym() const { return RnglistsTableBaseSym; }
 151   void setRnglistsTableBaseSym(MCSymbol *Sym) { RnglistsTableBaseSym = Sym; }
 152
 153   void 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 DILocalScope *, DIE *> &getAbstractScopeDIEs() {
 166     return AbstractLocalScopeDIEs;
 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