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/Support/Compiler.h"
20 #include "llvm/Support/Dwarf.h"
21 #include "llvm/Support/raw_ostream.h"
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).
40 // Name - the base name of the file without its directory path.
41 // The StringRef references memory allocated in the MCContext.
44 // DirIndex - the index into the list of directory names for this file name.
47 private: // MCContext creates and uniques these.
48 friend class MCContext;
49 MCDwarfFile(StringRef name, unsigned dirIndex)
50 : Name(name), DirIndex(dirIndex) {}
52 MCDwarfFile(const MCDwarfFile &) LLVM_DELETED_FUNCTION;
53 void operator=(const MCDwarfFile &) LLVM_DELETED_FUNCTION;
56 /// getName - Get the base name of this MCDwarfFile.
57 StringRef getName() const { return Name; }
59 /// getDirIndex - Get the dirIndex of this MCDwarfFile.
60 unsigned getDirIndex() const { return DirIndex; }
62 /// print - Print the value to the stream \p OS.
63 void print(raw_ostream &OS) const;
65 /// dump - Print the value to stderr.
69 inline raw_ostream &operator<<(raw_ostream &OS, const MCDwarfFile &DwarfFile) {
74 /// MCDwarfLoc - Instances of this class represent the information from a
75 /// dwarf .loc directive.
77 // FileNum - the file number.
79 // Line - the line number.
81 // Column - the column position.
83 // Flags (see #define's below)
88 unsigned Discriminator;
90 // Flag that indicates the initial value of the is_stmt_start flag.
91 #define DWARF2_LINE_DEFAULT_IS_STMT 1
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)
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) {}
106 // Allow the default copy constructor and assignment operator to be used
107 // for an MCDwarfLoc object.
110 /// getFileNum - Get the FileNum of this MCDwarfLoc.
111 unsigned getFileNum() const { return FileNum; }
113 /// getLine - Get the Line of this MCDwarfLoc.
114 unsigned getLine() const { return Line; }
116 /// getColumn - Get the Column of this MCDwarfLoc.
117 unsigned getColumn() const { return Column; }
119 /// getFlags - Get the Flags of this MCDwarfLoc.
120 unsigned getFlags() const { return Flags; }
122 /// getIsa - Get the Isa of this MCDwarfLoc.
123 unsigned getIsa() const { return Isa; }
125 /// getDiscriminator - Get the Discriminator of this MCDwarfLoc.
126 unsigned getDiscriminator() const { return Discriminator; }
128 /// setFileNum - Set the FileNum of this MCDwarfLoc.
129 void setFileNum(unsigned fileNum) { FileNum = fileNum; }
131 /// setLine - Set the Line of this MCDwarfLoc.
132 void setLine(unsigned line) { Line = line; }
134 /// setColumn - Set the Column of this MCDwarfLoc.
135 void setColumn(unsigned column) { Column = column; }
137 /// setFlags - Set the Flags of this MCDwarfLoc.
138 void setFlags(unsigned flags) { Flags = flags; }
140 /// setIsa - Set the Isa of this MCDwarfLoc.
141 void setIsa(unsigned isa) { Isa = isa; }
143 /// setDiscriminator - Set the Discriminator of this MCDwarfLoc.
144 void setDiscriminator(unsigned discriminator) {
145 Discriminator = discriminator;
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 {
158 // Allow the default copy constructor and assignment operator to be used
159 // for an MCLineEntry object.
162 // Constructor to create an MCLineEntry given a symbol and the dwarf loc.
163 MCLineEntry(MCSymbol *label, const MCDwarfLoc loc)
164 : MCDwarfLoc(loc), Label(label) {}
166 MCSymbol *getLabel() const { return Label; }
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);
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 {
181 MCLineSection(const MCLineSection &) LLVM_DELETED_FUNCTION;
182 void operator=(const MCLineSection &) LLVM_DELETED_FUNCTION;
185 // Constructor to create an MCLineSection with an empty MCLineEntries
189 // addLineEntry - adds an entry to this MCLineSection's line entries
190 void addLineEntry(const MCLineEntry &LineEntry, unsigned CUID) {
191 MCLineDivisions[CUID].push_back(LineEntry);
194 typedef std::vector<MCLineEntry> MCLineEntryCollection;
195 typedef MCLineEntryCollection::iterator iterator;
196 typedef MCLineEntryCollection::const_iterator const_iterator;
197 typedef std::map<unsigned, MCLineEntryCollection> MCLineDivisionMap;
200 // A collection of MCLineEntry for each Compile Unit ID.
201 MCLineDivisionMap MCLineDivisions;
204 // Returns whether MCLineSection contains entries for a given Compile
206 bool containEntriesForID(unsigned CUID) const {
207 return MCLineDivisions.count(CUID);
209 // Returns the collection of MCLineEntry for a given Compile Unit ID.
210 const MCLineEntryCollection &getMCLineEntries(unsigned CUID) const {
211 MCLineDivisionMap::const_iterator CIter = MCLineDivisions.find(CUID);
212 assert(CIter != MCLineDivisions.end());
213 return CIter->second;
217 class MCDwarfFileTable {
220 // This emits the Dwarf file and the line tables for all Compile Units.
222 static const MCSymbol *Emit(MCStreamer *MCOS);
224 // This emits the Dwarf file and the line tables for a given Compile Unit.
226 static const MCSymbol *EmitCU(MCStreamer *MCOS, unsigned ID);
229 class MCDwarfLineAddr {
231 /// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas.
232 static void Encode(MCContext &Context, int64_t LineDelta, uint64_t AddrDelta,
235 /// Utility function to emit the encoding to a streamer.
236 static void Emit(MCStreamer *MCOS, int64_t LineDelta, uint64_t AddrDelta);
239 class MCGenDwarfInfo {
242 // When generating dwarf for assembly source files this emits the Dwarf
245 static void Emit(MCStreamer *MCOS, const MCSymbol *LineSectionSymbol);
248 // When generating dwarf for assembly source files this is the info that is
249 // needed to be gathered for each symbol that will have a dwarf label.
250 class MCGenDwarfLabelEntry {
252 // Name of the symbol without a leading underbar, if any.
254 // The dwarf file number this symbol is in.
256 // The line number this symbol is at.
258 // The low_pc for the dwarf label is taken from this symbol.
262 MCGenDwarfLabelEntry(StringRef name, unsigned fileNumber, unsigned lineNumber,
264 : Name(name), FileNumber(fileNumber), LineNumber(lineNumber),
267 StringRef getName() const { return Name; }
268 unsigned getFileNumber() const { return FileNumber; }
269 unsigned getLineNumber() const { return LineNumber; }
270 MCSymbol *getLabel() const { return Label; }
272 // This is called when label is created when we are generating dwarf for
273 // assembly source files.
274 static void Make(MCSymbol *Symbol, MCStreamer *MCOS, SourceMgr &SrcMgr,
278 class MCCFIInstruction {
305 std::vector<char> Values;
307 MCCFIInstruction(OpType Op, MCSymbol *L, unsigned R, int O, StringRef V)
308 : Operation(Op), Label(L), Register(R), Offset(O),
309 Values(V.begin(), V.end()) {
310 assert(Op != OpRegister);
313 MCCFIInstruction(OpType Op, MCSymbol *L, unsigned R1, unsigned R2)
314 : Operation(Op), Label(L), Register(R1), Register2(R2) {
315 assert(Op == OpRegister);
319 /// \brief .cfi_def_cfa defines a rule for computing CFA as: take address from
320 /// Register and add Offset to it.
321 static MCCFIInstruction createDefCfa(MCSymbol *L, unsigned Register,
323 return MCCFIInstruction(OpDefCfa, L, Register, -Offset, "");
326 /// \brief .cfi_def_cfa_register modifies a rule for computing CFA. From now
327 /// on Register will be used instead of the old one. Offset remains the same.
328 static MCCFIInstruction createDefCfaRegister(MCSymbol *L, unsigned Register) {
329 return MCCFIInstruction(OpDefCfaRegister, L, Register, 0, "");
332 /// \brief .cfi_def_cfa_offset modifies a rule for computing CFA. Register
333 /// remains the same, but offset is new. Note that it is the absolute offset
334 /// that will be added to a defined register to the compute CFA address.
335 static MCCFIInstruction createDefCfaOffset(MCSymbol *L, int Offset) {
336 return MCCFIInstruction(OpDefCfaOffset, L, 0, -Offset, "");
339 /// \brief .cfi_adjust_cfa_offset Same as .cfi_def_cfa_offset, but
340 /// Offset is a relative value that is added/subtracted from the previous
342 static MCCFIInstruction createAdjustCfaOffset(MCSymbol *L, int Adjustment) {
343 return MCCFIInstruction(OpAdjustCfaOffset, L, 0, Adjustment, "");
346 /// \brief .cfi_offset Previous value of Register is saved at offset Offset
348 static MCCFIInstruction createOffset(MCSymbol *L, unsigned Register,
350 return MCCFIInstruction(OpOffset, L, Register, Offset, "");
353 /// \brief .cfi_rel_offset Previous value of Register is saved at offset
354 /// Offset from the current CFA register. This is transformed to .cfi_offset
355 /// using the known displacement of the CFA register from the CFA.
356 static MCCFIInstruction createRelOffset(MCSymbol *L, unsigned Register,
358 return MCCFIInstruction(OpRelOffset, L, Register, Offset, "");
361 /// \brief .cfi_register Previous value of Register1 is saved in
362 /// register Register2.
363 static MCCFIInstruction createRegister(MCSymbol *L, unsigned Register1,
364 unsigned Register2) {
365 return MCCFIInstruction(OpRegister, L, Register1, Register2);
368 /// \brief .cfi_window_save SPARC register window is saved.
369 static MCCFIInstruction createWindowSave(MCSymbol *L) {
370 return MCCFIInstruction(OpWindowSave, L, 0, 0, "");
373 /// \brief .cfi_restore says that the rule for Register is now the same as it
374 /// was at the beginning of the function, after all initial instructions added
375 /// by .cfi_startproc were executed.
376 static MCCFIInstruction createRestore(MCSymbol *L, unsigned Register) {
377 return MCCFIInstruction(OpRestore, L, Register, 0, "");
380 /// \brief .cfi_undefined From now on the previous value of Register can't be
381 /// restored anymore.
382 static MCCFIInstruction createUndefined(MCSymbol *L, unsigned Register) {
383 return MCCFIInstruction(OpUndefined, L, Register, 0, "");
386 /// \brief .cfi_same_value Current value of Register is the same as in the
387 /// previous frame. I.e., no restoration is needed.
388 static MCCFIInstruction createSameValue(MCSymbol *L, unsigned Register) {
389 return MCCFIInstruction(OpSameValue, L, Register, 0, "");
392 /// \brief .cfi_remember_state Save all current rules for all registers.
393 static MCCFIInstruction createRememberState(MCSymbol *L) {
394 return MCCFIInstruction(OpRememberState, L, 0, 0, "");
397 /// \brief .cfi_restore_state Restore the previously saved state.
398 static MCCFIInstruction createRestoreState(MCSymbol *L) {
399 return MCCFIInstruction(OpRestoreState, L, 0, 0, "");
402 /// \brief .cfi_escape Allows the user to add arbitrary bytes to the unwind
404 static MCCFIInstruction createEscape(MCSymbol *L, StringRef Vals) {
405 return MCCFIInstruction(OpEscape, L, 0, 0, Vals);
408 OpType getOperation() const { return Operation; }
409 MCSymbol *getLabel() const { return Label; }
411 unsigned getRegister() const {
412 assert(Operation == OpDefCfa || Operation == OpOffset ||
413 Operation == OpRestore || Operation == OpUndefined ||
414 Operation == OpSameValue || Operation == OpDefCfaRegister ||
415 Operation == OpRelOffset || Operation == OpRegister);
419 unsigned getRegister2() const {
420 assert(Operation == OpRegister);
424 int getOffset() const {
425 assert(Operation == OpDefCfa || Operation == OpOffset ||
426 Operation == OpRelOffset || Operation == OpDefCfaOffset ||
427 Operation == OpAdjustCfaOffset);
431 const StringRef getValues() const {
432 assert(Operation == OpEscape);
433 return StringRef(&Values[0], Values.size());
437 struct MCDwarfFrameInfo {
439 : Begin(0), End(0), Personality(0), Lsda(0), Function(0), Instructions(),
440 PersonalityEncoding(), LsdaEncoding(0), CompactUnwindEncoding(0),
441 IsSignalFrame(false) {}
444 const MCSymbol *Personality;
445 const MCSymbol *Lsda;
446 const MCSymbol *Function;
447 std::vector<MCCFIInstruction> Instructions;
448 unsigned PersonalityEncoding;
449 unsigned LsdaEncoding;
450 uint32_t CompactUnwindEncoding;
454 class MCDwarfFrameEmitter {
457 // This emits the frame info section.
459 static void Emit(MCStreamer &streamer, MCAsmBackend *MAB,
460 bool usingCFI, bool isEH);
461 static void EmitAdvanceLoc(MCStreamer &Streamer, uint64_t AddrDelta);
462 static void EncodeAdvanceLoc(MCContext &Context, uint64_t AddrDelta,
465 } // end namespace llvm