1 //===- MCDwarf.h - Machine Code Dwarf support -------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the declaration of the MCDwarfFile to support the dwarf
11 // .file directive and the .loc directive.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_MC_MCDWARF_H
16 #define LLVM_MC_MCDWARF_H
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/MC/MachineLocation.h"
20 #include "llvm/Support/raw_ostream.h"
21 #include "llvm/Support/Dwarf.h"
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).
39 // Name - the base name of the file without its directory path.
40 // The StringRef references memory allocated in the MCContext.
43 // DirIndex - the index into the list of directory names for this file name.
46 private: // MCContext creates and uniques these.
47 friend class MCContext;
48 MCDwarfFile(StringRef name, unsigned dirIndex)
49 : Name(name), DirIndex(dirIndex) {}
51 MCDwarfFile(const MCDwarfFile&); // DO NOT IMPLEMENT
52 void operator=(const MCDwarfFile&); // DO NOT IMPLEMENT
54 /// getName - Get the base name of this MCDwarfFile.
55 StringRef getName() const { return Name; }
57 /// getDirIndex - Get the dirIndex of this MCDwarfFile.
58 unsigned getDirIndex() const { return DirIndex; }
61 /// print - Print the value to the stream \arg OS.
62 void print(raw_ostream &OS) const;
64 /// dump - Print the value to stderr.
68 inline raw_ostream &operator<<(raw_ostream &OS, const MCDwarfFile &DwarfFile){
73 /// MCDwarfLoc - Instances of this class represent the information from a
74 /// dwarf .loc directive.
76 // FileNum - the file number.
78 // Line - the line number.
80 // Column - the column position.
82 // Flags (see #define's below)
87 unsigned Discriminator;
89 // Flag that indicates the initial value of the is_stmt_start flag.
90 #define DWARF2_LINE_DEFAULT_IS_STMT 1
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)
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) {}
105 // Allow the default copy constructor and assignment operator to be used
106 // for an MCDwarfLoc object.
109 /// getFileNum - Get the FileNum of this MCDwarfLoc.
110 unsigned getFileNum() const { return FileNum; }
112 /// getLine - Get the Line of this MCDwarfLoc.
113 unsigned getLine() const { return Line; }
115 /// getColumn - Get the Column of this MCDwarfLoc.
116 unsigned getColumn() const { return Column; }
118 /// getFlags - Get the Flags of this MCDwarfLoc.
119 unsigned getFlags() const { return Flags; }
121 /// getIsa - Get the Isa of this MCDwarfLoc.
122 unsigned getIsa() const { return Isa; }
124 /// getDiscriminator - Get the Discriminator of this MCDwarfLoc.
125 unsigned getDiscriminator() const { return Discriminator; }
127 /// setFileNum - Set the FileNum of this MCDwarfLoc.
128 void setFileNum(unsigned fileNum) { FileNum = fileNum; }
130 /// setLine - Set the Line of this MCDwarfLoc.
131 void setLine(unsigned line) { Line = line; }
133 /// setColumn - Set the Column of this MCDwarfLoc.
134 void setColumn(unsigned column) { Column = column; }
136 /// setFlags - Set the Flags of this MCDwarfLoc.
137 void setFlags(unsigned flags) { Flags = flags; }
139 /// setIsa - Set the Isa of this MCDwarfLoc.
140 void setIsa(unsigned isa) { Isa = isa; }
142 /// setDiscriminator - Set the Discriminator of this MCDwarfLoc.
143 void setDiscriminator(unsigned discriminator) {
144 Discriminator = discriminator;
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 {
157 // Allow the default copy constructor and assignment operator to be used
158 // for an MCLineEntry object.
161 // Constructor to create an MCLineEntry given a symbol and the dwarf loc.
162 MCLineEntry(MCSymbol *label, const MCDwarfLoc loc) : MCDwarfLoc(loc),
165 MCSymbol *getLabel() const { return Label; }
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);
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 {
180 MCLineSection(const MCLineSection&); // DO NOT IMPLEMENT
181 void operator=(const MCLineSection&); // DO NOT IMPLEMENT
184 // Constructor to create an MCLineSection with an empty MCLineEntries
188 // addLineEntry - adds an entry to this MCLineSection's line entries
189 void addLineEntry(const MCLineEntry &LineEntry) {
190 MCLineEntries.push_back(LineEntry);
193 typedef std::vector<MCLineEntry> MCLineEntryCollection;
194 typedef MCLineEntryCollection::iterator iterator;
195 typedef MCLineEntryCollection::const_iterator const_iterator;
198 MCLineEntryCollection MCLineEntries;
201 const MCLineEntryCollection *getMCLineEntries() const {
202 return &MCLineEntries;
206 class MCDwarfFileTable {
209 // This emits the Dwarf file and the line tables.
211 static const MCSymbol *Emit(MCStreamer *MCOS);
214 class MCDwarfLineAddr {
216 /// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas.
217 static void Encode(int64_t LineDelta, uint64_t AddrDelta, raw_ostream &OS);
219 /// Utility function to emit the encoding to a streamer.
220 static void Emit(MCStreamer *MCOS,
221 int64_t LineDelta,uint64_t AddrDelta);
223 /// Utility function to write the encoding to an object writer.
224 static void Write(MCObjectWriter *OW,
225 int64_t LineDelta, uint64_t AddrDelta);
228 class MCGenDwarfInfo {
231 // When generating dwarf for assembly source files this emits the Dwarf
234 static void Emit(MCStreamer *MCOS, const MCSymbol *LineSectionSymbol);
237 // When generating dwarf for assembly source files this is the info that is
238 // needed to be gathered for each symbol that will have a dwarf label.
239 class MCGenDwarfLabelEntry {
241 // Name of the symbol without a leading underbar, if any.
243 // The dwarf file number this symbol is in.
245 // The line number this symbol is at.
247 // The low_pc for the dwarf label is taken from this symbol.
251 MCGenDwarfLabelEntry(StringRef name, unsigned fileNumber,
252 unsigned lineNumber, MCSymbol *label) :
253 Name(name), FileNumber(fileNumber), LineNumber(lineNumber), Label(label){}
255 StringRef getName() const { return Name; }
256 unsigned getFileNumber() const { return FileNumber; }
257 unsigned getLineNumber() const { return LineNumber; }
258 MCSymbol *getLabel() const { return Label; }
260 // This is called when label is created when we are generating dwarf for
261 // assembly source files.
262 static void Make(MCSymbol *Symbol, MCStreamer *MCOS, SourceMgr &SrcMgr,
266 class MCCFIInstruction {
268 enum OpType { SameValue, RememberState, RestoreState, Move, RelMove, Escape,
273 // Move to & from location.
274 MachineLocation Destination;
275 MachineLocation Source;
276 std::vector<char> Values;
278 MCCFIInstruction(OpType Op, MCSymbol *L)
279 : Operation(Op), Label(L) {
280 assert(Op == RememberState || Op == RestoreState);
282 MCCFIInstruction(OpType Op, MCSymbol *L, unsigned Register)
283 : Operation(Op), Label(L), Destination(Register) {
284 assert(Op == SameValue || Op == Restore);
286 MCCFIInstruction(MCSymbol *L, const MachineLocation &D,
287 const MachineLocation &S)
288 : Operation(Move), Label(L), Destination(D), Source(S) {
290 MCCFIInstruction(OpType Op, MCSymbol *L, const MachineLocation &D,
291 const MachineLocation &S)
292 : Operation(Op), Label(L), Destination(D), Source(S) {
293 assert(Op == RelMove);
295 MCCFIInstruction(OpType Op, MCSymbol *L, StringRef Vals)
296 : Operation(Op), Label(L), Values(Vals.begin(), Vals.end()) {
297 assert(Op == Escape);
299 OpType getOperation() const { return Operation; }
300 MCSymbol *getLabel() const { return Label; }
301 const MachineLocation &getDestination() const { return Destination; }
302 const MachineLocation &getSource() const { return Source; }
303 const StringRef getValues() const {
304 return StringRef(&Values[0], Values.size());
308 struct MCDwarfFrameInfo {
309 MCDwarfFrameInfo() : Begin(0), End(0), Personality(0), Lsda(0),
310 Function(0), Instructions(), PersonalityEncoding(),
311 LsdaEncoding(0), CompactUnwindEncoding(0),
312 IsSignalFrame(false) {}
315 const MCSymbol *Personality;
316 const MCSymbol *Lsda;
317 const MCSymbol *Function;
318 std::vector<MCCFIInstruction> Instructions;
319 unsigned PersonalityEncoding;
320 unsigned LsdaEncoding;
321 uint32_t CompactUnwindEncoding;
325 class MCDwarfFrameEmitter {
328 // This emits the frame info section.
330 static void Emit(MCStreamer &streamer, bool usingCFI,
332 static void EmitAdvanceLoc(MCStreamer &Streamer, uint64_t AddrDelta);
333 static void EncodeAdvanceLoc(uint64_t AddrDelta, raw_ostream &OS);
335 } // end namespace llvm