MCDwarf.h revision 3a83c40ab61d5ca624f2bbadd70237c6adbdb304 
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/MCObjectWriter.h"
20#include "llvm/Support/raw_ostream.h"
21#include "llvm/Support/Dwarf.h"
22#include <vector>
23
24namespace llvm {
25  class MachineMove;
26  class MCContext;
27  class MCSection;
28  class MCSectionData;
29  class MCStreamer;
30  class MCSymbol;
31  class MCObjectStreamer;
32  class raw_ostream;
33
34  /// MCDwarfFile - Instances of this class represent the name of the dwarf
35  /// .file directive and its associated dwarf file number in the MC file,
36  /// and MCDwarfFile's are created and unique'd by the MCContext class where
37  /// the file number for each is its index into the vector of DwarfFiles (note
38  /// index 0 is not used and not a valid dwarf file number).
39  class MCDwarfFile {
40    // Name - the base name of the file without its directory path.
41    // The StringRef references memory allocated in the MCContext.
42    StringRef Name;
43
44    // DirIndex - the index into the list of directory names for this file name.
45    unsigned DirIndex;
46
47  private:  // MCContext creates and uniques these.
48    friend class MCContext;
49    MCDwarfFile(StringRef name, unsigned dirIndex)
50      : Name(name), DirIndex(dirIndex) {}
51
52    MCDwarfFile(const MCDwarfFile&);       // DO NOT IMPLEMENT
53    void operator=(const MCDwarfFile&); // DO NOT IMPLEMENT
54  public:
55    /// getName - Get the base name of this MCDwarfFile.
56    StringRef getName() const { return Name; }
57
58    /// getDirIndex - Get the dirIndex of this MCDwarfFile.
59    unsigned getDirIndex() const { return DirIndex; }
60
61
62    /// print - Print the value to the stream \arg OS.
63    void print(raw_ostream &OS) const;
64
65    /// dump - Print the value to stderr.
66    void dump() const;
67  };
68
69  inline raw_ostream &operator<<(raw_ostream &OS, const MCDwarfFile &DwarfFile){
70    DwarfFile.print(OS);
71    return OS;
72  }
73
74  /// MCDwarfLoc - Instances of this class represent the information from a
75  /// dwarf .loc directive.
76  class MCDwarfLoc {
77    // FileNum - the file number.
78    unsigned FileNum;
79    // Line - the line number.
80    unsigned Line;
81    // Column - the column position.
82    unsigned Column;
83    // Flags (see #define's below)
84    unsigned Flags;
85    // Isa
86    unsigned Isa;
87    // Discriminator
88    unsigned Discriminator;
89
90// Flag that indicates the initial value of the is_stmt_start flag.
91#define DWARF2_LINE_DEFAULT_IS_STMT     1
92
93#define DWARF2_FLAG_IS_STMT        (1 << 0)
94#define DWARF2_FLAG_BASIC_BLOCK    (1 << 1)
95#define DWARF2_FLAG_PROLOGUE_END   (1 << 2)
96#define DWARF2_FLAG_EPILOGUE_BEGIN (1 << 3)
97
98  private:  // MCContext manages these
99    friend class MCContext;
100    friend class MCLineEntry;
101    MCDwarfLoc(unsigned fileNum, unsigned line, unsigned column, unsigned flags,
102               unsigned isa, unsigned discriminator)
103      : FileNum(fileNum), Line(line), Column(column), Flags(flags), Isa(isa),
104        Discriminator(discriminator) {}
105
106    // Allow the default copy constructor and assignment operator to be used
107    // for an MCDwarfLoc object.
108
109  public:
110    /// getFileNum - Get the FileNum of this MCDwarfLoc.
111    unsigned getFileNum() const { return FileNum; }
112
113    /// getLine - Get the Line of this MCDwarfLoc.
114    unsigned getLine() const { return Line; }
115
116    /// getColumn - Get the Column of this MCDwarfLoc.
117    unsigned getColumn() const { return Column; }
118
119    /// getFlags - Get the Flags of this MCDwarfLoc.
120    unsigned getFlags() const { return Flags; }
121
122    /// getIsa - Get the Isa of this MCDwarfLoc.
123    unsigned getIsa() const { return Isa; }
124
125    /// getDiscriminator - Get the Discriminator of this MCDwarfLoc.
126    unsigned getDiscriminator() const { return Discriminator; }
127
128    /// setFileNum - Set the FileNum of this MCDwarfLoc.
129    void setFileNum(unsigned fileNum) { FileNum = fileNum; }
130
131    /// setLine - Set the Line of this MCDwarfLoc.
132    void setLine(unsigned line) { Line = line; }
133
134    /// setColumn - Set the Column of this MCDwarfLoc.
135    void setColumn(unsigned column) { Column = column; }
136
137    /// setFlags - Set the Flags of this MCDwarfLoc.
138    void setFlags(unsigned flags) { Flags = flags; }
139
140    /// setIsa - Set the Isa of this MCDwarfLoc.
141    void setIsa(unsigned isa) { Isa = isa; }
142
143    /// setDiscriminator - Set the Discriminator of this MCDwarfLoc.
144    void setDiscriminator(unsigned discriminator) {
145      Discriminator = discriminator;
146    }
147  };
148
149  /// MCLineEntry - Instances of this class represent the line information for
150  /// the dwarf line table entries.  Which is created after a machine
151  /// instruction is assembled and uses an address from a temporary label
152  /// created at the current address in the current section and the info from
153  /// the last .loc directive seen as stored in the context.
154  class MCLineEntry : public MCDwarfLoc {
155    MCSymbol *Label;
156
157  private:
158    // Allow the default copy constructor and assignment operator to be used
159    // for an MCLineEntry object.
160
161  public:
162    // Constructor to create an MCLineEntry given a symbol and the dwarf loc.
163    MCLineEntry(MCSymbol *label, const MCDwarfLoc loc) : MCDwarfLoc(loc),
164                Label(label) {}
165
166    MCSymbol *getLabel() const { return Label; }
167
168    // This is called when an instruction is assembled into the specified
169    // section and if there is information from the last .loc directive that
170    // has yet to have a line entry made for it is made.
171    static void Make(MCStreamer *MCOS, const MCSection *Section);
172  };
173
174  /// MCLineSection - Instances of this class represent the line information
175  /// for a section where machine instructions have been assembled after seeing
176  /// .loc directives.  This is the information used to build the dwarf line
177  /// table for a section.
178  class MCLineSection {
179
180  private:
181    MCLineSection(const MCLineSection&);  // DO NOT IMPLEMENT
182    void operator=(const MCLineSection&); // DO NOT IMPLEMENT
183
184  public:
185    // Constructor to create an MCLineSection with an empty MCLineEntries
186    // vector.
187    MCLineSection() {}
188
189    // addLineEntry - adds an entry to this MCLineSection's line entries
190    void addLineEntry(const MCLineEntry &LineEntry) {
191      MCLineEntries.push_back(LineEntry);
192    }
193
194    typedef std::vector<MCLineEntry> MCLineEntryCollection;
195    typedef MCLineEntryCollection::iterator iterator;
196    typedef MCLineEntryCollection::const_iterator const_iterator;
197
198  private:
199    MCLineEntryCollection MCLineEntries;
200
201  public:
202    const MCLineEntryCollection *getMCLineEntries() const {
203      return &MCLineEntries;
204    }
205  };
206
207  class MCDwarfFileTable {
208  public:
209    //
210    // This emits the Dwarf file and the line tables.
211    //
212    static void Emit(MCStreamer *MCOS);
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 write the encoding to an object writer.
225    static void Write(MCObjectWriter *OW,
226                      int64_t LineDelta, uint64_t AddrDelta);
227  };
228
229  struct MCDwarfFrameInfo {
230    MCSymbol *Begin;
231    MCSymbol *End;
232    const MCSymbol *Personality;
233    const MCSymbol *Lsda;
234    unsigned PersonalityEncoding;
235  };
236
237  class MCDwarfFrameEmitter {
238  public:
239    //
240    // This emits the frame info section.
241    //
242    static void Emit(MCStreamer &streamer);
243  };
244} // end namespace llvm
245
246#endif
247