include/llvm/MC/MCDwarf.h

   1 //===- MCDwarf.h - Machine Code Dwarf support -------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file contains the declaration of the MCDwarfFile to support the dwarf
  11 // .file directive and the .loc directive.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_MC_MCDWARF_H
  16 #define LLVM_MC_MCDWARF_H
  17
  18 #include "llvm/ADT/StringRef.h"
  19 #include "llvm/MC/MCStreamer.h"
  20 #include "llvm/MC/MCObjectStreamer.h"
  21 #include "llvm/MC/MCObjectWriter.h"
  22 #include "llvm/Support/raw_ostream.h"
  23 #include "llvm/Support/Dwarf.h"
  24 #include <vector>
  25
  26 namespace llvm {
  27   class MCContext;
  28   class MCSection;
  29   class MCSymbol;
  30   class MCObjectStreamer;
  31   class raw_ostream;
  32
  33   /// MCDwarfFile - Instances of this class represent the name of the dwarf
  34   /// .file directive and its associated dwarf file number in the MC file,
  35   /// and MCDwarfFile's are created and unique'd by the MCContext class where
  36   /// the file number for each is its index into the vector of DwarfFiles (note
  37   /// index 0 is not used and not a valid dwarf file number).
  38   class MCDwarfFile {
  39     // Name - the base name of the file without its directory path.
  40     // The StringRef references memory allocated in the MCContext.
  41     StringRef Name;
  42
  43     // DirIndex - the index into the list of directory names for this file name.
  44     unsigned DirIndex;
  45
  46   private:  // MCContext creates and uniques these.
  47     friend class MCContext;
  48     MCDwarfFile(StringRef name, unsigned dirIndex)
  49       : Name(name), DirIndex(dirIndex) {}
  50
  51     MCDwarfFile(const MCDwarfFile&);       // DO NOT IMPLEMENT
  52     void operator=(const MCDwarfFile&); // DO NOT IMPLEMENT
  53   public:
  54     /// getName - Get the base name of this MCDwarfFile.
  55     StringRef getName() const { return Name; }
  56
  57     /// getDirIndex - Get the dirIndex of this MCDwarfFile.
  58     unsigned getDirIndex() const { return DirIndex; }
  59
  60
  61     /// print - Print the value to the stream \arg OS.
  62     void print(raw_ostream &OS) const;
  63
  64     /// dump - Print the value to stderr.
  65     void dump() const;
  66   };
  67
  68   inline raw_ostream &operator<<(raw_ostream &OS, const MCDwarfFile &DwarfFile){
  69     DwarfFile.print(OS);
  70     return OS;
  71   }
  72
  73   /// MCDwarfLoc - Instances of this class represent the information from a
  74   /// dwarf .loc directive.
  75   class MCDwarfLoc {
  76     // FileNum - the file number.
  77     unsigned FileNum;
  78     // Line - the line number.
  79     unsigned Line;
  80     // Column - the column position.
  81     unsigned Column;
  82     // Flags (see #define's below)
  83     unsigned Flags;
  84     // Isa
  85     unsigned Isa;
  86     // Discriminator
  87     unsigned Discriminator;
  88
  89 // Flag that indicates the initial value of the is_stmt_start flag.
  90 #define DWARF2_LINE_DEFAULT_IS_STMT     1
  91
  92 #define DWARF2_FLAG_IS_STMT        (1 << 0)
  93 #define DWARF2_FLAG_BASIC_BLOCK    (1 << 1)
  94 #define DWARF2_FLAG_PROLOGUE_END   (1 << 2)
  95 #define DWARF2_FLAG_EPILOGUE_BEGIN (1 << 3)
  96
  97   private:  // MCContext manages these
  98     friend class MCContext;
  99     friend class MCLineEntry;
 100     MCDwarfLoc(unsigned fileNum, unsigned line, unsigned column, unsigned flags,
 101                unsigned isa, unsigned discriminator)
 102       : FileNum(fileNum), Line(line), Column(column), Flags(flags), Isa(isa),
 103         Discriminator(discriminator) {}
 104
 105     // Allow the default copy constructor and assignment operator to be used
 106     // for an MCDwarfLoc object.
 107
 108   public:
 109     /// getFileNum - Get the FileNum of this MCDwarfLoc.
 110     unsigned getFileNum() const { return FileNum; }
 111
 112     /// getLine - Get the Line of this MCDwarfLoc.
 113     unsigned getLine() const { return Line; }
 114
 115     /// getColumn - Get the Column of this MCDwarfLoc.
 116     unsigned getColumn() const { return Column; }
 117
 118     /// getFlags - Get the Flags of this MCDwarfLoc.
 119     unsigned getFlags() const { return Flags; }
 120
 121     /// getIsa - Get the Isa of this MCDwarfLoc.
 122     unsigned getIsa() const { return Isa; }
 123
 124     /// getDiscriminator - Get the Discriminator of this MCDwarfLoc.
 125     unsigned getDiscriminator() const { return Discriminator; }
 126
 127     /// setFileNum - Set the FileNum of this MCDwarfLoc.
 128     void setFileNum(unsigned fileNum) { FileNum = fileNum; }
 129
 130     /// setLine - Set the Line of this MCDwarfLoc.
 131     void setLine(unsigned line) { Line = line; }
 132
 133     /// setColumn - Set the Column of this MCDwarfLoc.
 134     void setColumn(unsigned column) { Column = column; }
 135
 136     /// setFlags - Set the Flags of this MCDwarfLoc.
 137     void setFlags(unsigned flags) { Flags = flags; }
 138
 139     /// setIsa - Set the Isa of this MCDwarfLoc.
 140     void setIsa(unsigned isa) { Isa = isa; }
 141
 142     /// setDiscriminator - Set the Discriminator of this MCDwarfLoc.
 143     void setDiscriminator(unsigned discriminator) {
 144       Discriminator = discriminator;
 145     }
 146   };
 147
 148   /// MCLineEntry - Instances of this class represent the line information for
 149   /// the dwarf line table entries.  Which is created after a machine
 150   /// instruction is assembled and uses an address from a temporary label
 151   /// created at the current address in the current section and the info from
 152   /// the last .loc directive seen as stored in the context.
 153   class MCLineEntry : public MCDwarfLoc {
 154     MCSymbol *Label;
 155
 156   private:
 157     // Allow the default copy constructor and assignment operator to be used
 158     // for an MCLineEntry object.
 159
 160   public:
 161     // Constructor to create an MCLineEntry given a symbol and the dwarf loc.
 162     MCLineEntry(MCSymbol *label, const MCDwarfLoc loc) : MCDwarfLoc(loc),
 163                 Label(label) {}
 164
 165     MCSymbol *getLabel() const { return Label; }
 166
 167     // This is called when an instruction is assembled into the specified
 168     // section and if there is information from the last .loc directive that
 169     // has yet to have a line entry made for it is made.
 170     static void Make(MCStreamer *MCOS, const MCSection *Section);
 171   };
 172
 173   /// MCLineSection - Instances of this class represent the line information
 174   /// for a section where machine instructions have been assembled after seeing
 175   /// .loc directives.  This is the information used to build the dwarf line
 176   /// table for a section.
 177   class MCLineSection {
 178
 179   private:
 180     MCLineSection(const MCLineSection&);  // DO NOT IMPLEMENT
 181     void operator=(const MCLineSection&); // DO NOT IMPLEMENT
 182
 183   public:
 184     // Constructor to create an MCLineSection with an empty MCLineEntries
 185     // vector.
 186     MCLineSection() {}
 187
 188     // addLineEntry - adds an entry to this MCLineSection's line entries
 189     void addLineEntry(const MCLineEntry &LineEntry) {
 190       MCLineEntries.push_back(LineEntry);
 191     }
 192
 193     typedef std::vector<MCLineEntry> MCLineEntryCollection;
 194     typedef MCLineEntryCollection::iterator iterator;
 195     typedef MCLineEntryCollection::const_iterator const_iterator;
 196
 197   private:
 198     MCLineEntryCollection MCLineEntries;
 199
 200   public:
 201     const MCLineEntryCollection *getMCLineEntries() const {
 202       return &MCLineEntries;
 203     }
 204   };
 205
 206   class MCDwarfFileTable {
 207   public:
 208     //
 209     // This emits the Dwarf file and the line tables.
 210     //
 211     static void Emit(MCStreamer *MCOS, const MCSection *DwarfLineSection,
 212                      MCSectionData *DLS, int PointerSize);
 213   };
 214
 215   class MCDwarfLineAddr {
 216   public:
 217     /// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas.
 218     static void Encode(int64_t LineDelta, uint64_t AddrDelta, raw_ostream &OS);
 219
 220     /// Utility function to emit the encoding to a streamer.
 221     static void Emit(MCStreamer *MCOS,
 222                      int64_t LineDelta,uint64_t AddrDelta);
 223
 224     /// Utility function to compute the size of the encoding.
 225     static uint64_t ComputeSize(int64_t LineDelta, uint64_t AddrDelta);
 226
 227     /// Utility function to write the encoding to an object writer.
 228     static void Write(MCObjectWriter *OW,
 229                       int64_t LineDelta, uint64_t AddrDelta);
 230   };
 231 } // end namespace llvm
 232
 233 #endif