LLVM  3.7.0
MCDwarf.cpp
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1 //===- lib/MC/MCDwarf.cpp - MCDwarf implementation ------------------------===//
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 #include "llvm/MC/MCDwarf.h"
11 #include "llvm/ADT/Hashing.h"
12 #include "llvm/ADT/STLExtras.h"
13 #include "llvm/ADT/SmallString.h"
14 #include "llvm/ADT/Twine.h"
15 #include "llvm/Config/config.h"
16 #include "llvm/MC/MCAsmInfo.h"
17 #include "llvm/MC/MCContext.h"
18 #include "llvm/MC/MCExpr.h"
21 #include "llvm/MC/MCRegisterInfo.h"
22 #include "llvm/MC/MCSection.h"
23 #include "llvm/MC/MCSymbol.h"
24 #include "llvm/Support/Debug.h"
26 #include "llvm/Support/LEB128.h"
27 #include "llvm/Support/Path.h"
28 #include "llvm/Support/SourceMgr.h"
30 using namespace llvm;
31 
32 // Given a special op, return the address skip amount (in units of
33 // DWARF2_LINE_MIN_INSN_LENGTH.
34 #define SPECIAL_ADDR(op) (((op) - DWARF2_LINE_OPCODE_BASE)/DWARF2_LINE_RANGE)
35 
36 // The maximum address skip amount that can be encoded with a special op.
37 #define MAX_SPECIAL_ADDR_DELTA SPECIAL_ADDR(255)
38 
39 // First special line opcode - leave room for the standard opcodes.
40 // Note: If you want to change this, you'll have to update the
41 // "standard_opcode_lengths" table that is emitted in DwarfFileTable::Emit().
42 #define DWARF2_LINE_OPCODE_BASE 13
43 
44 // Minimum line offset in a special line info. opcode. This value
45 // was chosen to give a reasonable range of values.
46 #define DWARF2_LINE_BASE -5
47 
48 // Range of line offsets in a special line info. opcode.
49 #define DWARF2_LINE_RANGE 14
50 
51 static inline uint64_t ScaleAddrDelta(MCContext &Context, uint64_t AddrDelta) {
52  unsigned MinInsnLength = Context.getAsmInfo()->getMinInstAlignment();
53  if (MinInsnLength == 1)
54  return AddrDelta;
55  if (AddrDelta % MinInsnLength != 0) {
56  // TODO: report this error, but really only once.
57  ;
58  }
59  return AddrDelta / MinInsnLength;
60 }
61 
62 //
63 // This is called when an instruction is assembled into the specified section
64 // and if there is information from the last .loc directive that has yet to have
65 // a line entry made for it is made.
66 //
68  if (!MCOS->getContext().getDwarfLocSeen())
69  return;
70 
71  // Create a symbol at in the current section for use in the line entry.
72  MCSymbol *LineSym = MCOS->getContext().createTempSymbol();
73  // Set the value of the symbol to use for the MCLineEntry.
74  MCOS->EmitLabel(LineSym);
75 
76  // Get the current .loc info saved in the context.
77  const MCDwarfLoc &DwarfLoc = MCOS->getContext().getCurrentDwarfLoc();
78 
79  // Create a (local) line entry with the symbol and the current .loc info.
80  MCLineEntry LineEntry(LineSym, DwarfLoc);
81 
82  // clear DwarfLocSeen saying the current .loc info is now used.
83  MCOS->getContext().clearDwarfLocSeen();
84 
85  // Add the line entry to this section's entries.
86  MCOS->getContext()
88  .getMCLineSections()
89  .addLineEntry(LineEntry, Section);
90 }
91 
92 //
93 // This helper routine returns an expression of End - Start + IntVal .
94 //
95 static inline const MCExpr *MakeStartMinusEndExpr(const MCStreamer &MCOS,
96  const MCSymbol &Start,
97  const MCSymbol &End,
98  int IntVal) {
100  const MCExpr *Res =
101  MCSymbolRefExpr::create(&End, Variant, MCOS.getContext());
102  const MCExpr *RHS =
103  MCSymbolRefExpr::create(&Start, Variant, MCOS.getContext());
104  const MCExpr *Res1 =
106  const MCExpr *Res2 =
107  MCConstantExpr::create(IntVal, MCOS.getContext());
108  const MCExpr *Res3 =
110  return Res3;
111 }
112 
113 //
114 // This emits the Dwarf line table for the specified section from the entries
115 // in the LineSection.
116 //
117 static inline void
119  const MCLineSection::MCLineEntryCollection &LineEntries) {
120  unsigned FileNum = 1;
121  unsigned LastLine = 1;
122  unsigned Column = 0;
124  unsigned Isa = 0;
125  unsigned Discriminator = 0;
126  MCSymbol *LastLabel = nullptr;
127 
128  // Loop through each MCLineEntry and encode the dwarf line number table.
129  for (auto it = LineEntries.begin(),
130  ie = LineEntries.end();
131  it != ie; ++it) {
132 
133  if (FileNum != it->getFileNum()) {
134  FileNum = it->getFileNum();
136  MCOS->EmitULEB128IntValue(FileNum);
137  }
138  if (Column != it->getColumn()) {
139  Column = it->getColumn();
141  MCOS->EmitULEB128IntValue(Column);
142  }
143  if (Discriminator != it->getDiscriminator()) {
144  Discriminator = it->getDiscriminator();
145  unsigned Size = getULEB128Size(Discriminator);
147  MCOS->EmitULEB128IntValue(Size + 1);
149  MCOS->EmitULEB128IntValue(Discriminator);
150  }
151  if (Isa != it->getIsa()) {
152  Isa = it->getIsa();
154  MCOS->EmitULEB128IntValue(Isa);
155  }
156  if ((it->getFlags() ^ Flags) & DWARF2_FLAG_IS_STMT) {
157  Flags = it->getFlags();
159  }
160  if (it->getFlags() & DWARF2_FLAG_BASIC_BLOCK)
162  if (it->getFlags() & DWARF2_FLAG_PROLOGUE_END)
164  if (it->getFlags() & DWARF2_FLAG_EPILOGUE_BEGIN)
166 
167  int64_t LineDelta = static_cast<int64_t>(it->getLine()) - LastLine;
168  MCSymbol *Label = it->getLabel();
169 
170  // At this point we want to emit/create the sequence to encode the delta in
171  // line numbers and the increment of the address from the previous Label
172  // and the current Label.
173  const MCAsmInfo *asmInfo = MCOS->getContext().getAsmInfo();
174  MCOS->EmitDwarfAdvanceLineAddr(LineDelta, LastLabel, Label,
175  asmInfo->getPointerSize());
176 
177  LastLine = it->getLine();
178  LastLabel = Label;
179  }
180 
181  // Emit a DW_LNE_end_sequence for the end of the section.
182  // Use the section end label to compute the address delta and use INT64_MAX
183  // as the line delta which is the signal that this is actually a
184  // DW_LNE_end_sequence.
185  MCSymbol *SectionEnd = MCOS->endSection(Section);
186 
187  // Switch back the dwarf line section, in case endSection had to switch the
188  // section.
189  MCContext &Ctx = MCOS->getContext();
191 
192  const MCAsmInfo *AsmInfo = Ctx.getAsmInfo();
193  MCOS->EmitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, SectionEnd,
194  AsmInfo->getPointerSize());
195 }
196 
197 //
198 // This emits the Dwarf file and the line tables.
199 //
201  MCContext &context = MCOS->getContext();
202 
203  auto &LineTables = context.getMCDwarfLineTables();
204 
205  // Bail out early so we don't switch to the debug_line section needlessly and
206  // in doing so create an unnecessary (if empty) section.
207  if (LineTables.empty())
208  return;
209 
210  // Switch to the section where the table will be emitted into.
212 
213  // Handle the rest of the Compile Units.
214  for (const auto &CUIDTablePair : LineTables)
215  CUIDTablePair.second.EmitCU(MCOS);
216 }
217 
219  MCOS.EmitLabel(Header.Emit(&MCOS, None).second);
220 }
221 
222 std::pair<MCSymbol *, MCSymbol *> MCDwarfLineTableHeader::Emit(MCStreamer *MCOS) const {
223  static const char StandardOpcodeLengths[] = {
224  0, // length of DW_LNS_copy
225  1, // length of DW_LNS_advance_pc
226  1, // length of DW_LNS_advance_line
227  1, // length of DW_LNS_set_file
228  1, // length of DW_LNS_set_column
229  0, // length of DW_LNS_negate_stmt
230  0, // length of DW_LNS_set_basic_block
231  0, // length of DW_LNS_const_add_pc
232  1, // length of DW_LNS_fixed_advance_pc
233  0, // length of DW_LNS_set_prologue_end
234  0, // length of DW_LNS_set_epilogue_begin
235  1 // DW_LNS_set_isa
236  };
237  assert(array_lengthof(StandardOpcodeLengths) ==
239  return Emit(MCOS, StandardOpcodeLengths);
240 }
241 
242 static const MCExpr *forceExpAbs(MCStreamer &OS, const MCExpr* Expr) {
243  MCContext &Context = OS.getContext();
244  assert(!isa<MCSymbolRefExpr>(Expr));
245  if (Context.getAsmInfo()->hasAggressiveSymbolFolding())
246  return Expr;
247 
248  MCSymbol *ABS = Context.createTempSymbol();
249  OS.EmitAssignment(ABS, Expr);
250  return MCSymbolRefExpr::create(ABS, Context);
251 }
252 
253 static void emitAbsValue(MCStreamer &OS, const MCExpr *Value, unsigned Size) {
254  const MCExpr *ABS = forceExpAbs(OS, Value);
255  OS.EmitValue(ABS, Size);
256 }
257 
258 std::pair<MCSymbol *, MCSymbol *>
260  ArrayRef<char> StandardOpcodeLengths) const {
261 
262  MCContext &context = MCOS->getContext();
263 
264  // Create a symbol at the beginning of the line table.
265  MCSymbol *LineStartSym = Label;
266  if (!LineStartSym)
267  LineStartSym = context.createTempSymbol();
268  // Set the value of the symbol, as we are at the start of the line table.
269  MCOS->EmitLabel(LineStartSym);
270 
271  // Create a symbol for the end of the section (to be set when we get there).
272  MCSymbol *LineEndSym = context.createTempSymbol();
273 
274  // The first 4 bytes is the total length of the information for this
275  // compilation unit (not including these 4 bytes for the length).
276  emitAbsValue(*MCOS,
277  MakeStartMinusEndExpr(*MCOS, *LineStartSym, *LineEndSym, 4), 4);
278 
279  // Next 2 bytes is the Version, which is Dwarf 2.
280  MCOS->EmitIntValue(2, 2);
281 
282  // Create a symbol for the end of the prologue (to be set when we get there).
283  MCSymbol *ProEndSym = context.createTempSymbol(); // Lprologue_end
284 
285  // Length of the prologue, is the next 4 bytes. Which is the start of the
286  // section to the end of the prologue. Not including the 4 bytes for the
287  // total length, the 2 bytes for the version, and these 4 bytes for the
288  // length of the prologue.
289  emitAbsValue(
290  *MCOS,
291  MakeStartMinusEndExpr(*MCOS, *LineStartSym, *ProEndSym, (4 + 2 + 4)), 4);
292 
293  // Parameters of the state machine, are next.
294  MCOS->EmitIntValue(context.getAsmInfo()->getMinInstAlignment(), 1);
296  MCOS->EmitIntValue(DWARF2_LINE_BASE, 1);
298  MCOS->EmitIntValue(StandardOpcodeLengths.size() + 1, 1);
299 
300  // Standard opcode lengths
301  for (char Length : StandardOpcodeLengths)
302  MCOS->EmitIntValue(Length, 1);
303 
304  // Put out the directory and file tables.
305 
306  // First the directory table.
307  for (unsigned i = 0; i < MCDwarfDirs.size(); i++) {
308  MCOS->EmitBytes(MCDwarfDirs[i]); // the DirectoryName
309  MCOS->EmitBytes(StringRef("\0", 1)); // the null term. of the string
310  }
311  MCOS->EmitIntValue(0, 1); // Terminate the directory list
312 
313  // Second the file table.
314  for (unsigned i = 1; i < MCDwarfFiles.size(); i++) {
315  assert(!MCDwarfFiles[i].Name.empty());
316  MCOS->EmitBytes(MCDwarfFiles[i].Name); // FileName
317  MCOS->EmitBytes(StringRef("\0", 1)); // the null term. of the string
318  // the Directory num
319  MCOS->EmitULEB128IntValue(MCDwarfFiles[i].DirIndex);
320  MCOS->EmitIntValue(0, 1); // last modification timestamp (always 0)
321  MCOS->EmitIntValue(0, 1); // filesize (always 0)
322  }
323  MCOS->EmitIntValue(0, 1); // Terminate the file list
324 
325  // This is the end of the prologue, so set the value of the symbol at the
326  // end of the prologue (that was used in a previous expression).
327  MCOS->EmitLabel(ProEndSym);
328 
329  return std::make_pair(LineStartSym, LineEndSym);
330 }
331 
333  MCSymbol *LineEndSym = Header.Emit(MCOS).second;
334 
335  // Put out the line tables.
336  for (const auto &LineSec : MCLineSections.getMCLineEntries())
337  EmitDwarfLineTable(MCOS, LineSec.first, LineSec.second);
338 
339  // This is the end of the section, so set the value of the symbol at the end
340  // of this section (that was used in a previous expression).
341  MCOS->EmitLabel(LineEndSym);
342 }
343 
344 unsigned MCDwarfLineTable::getFile(StringRef &Directory, StringRef &FileName,
345  unsigned FileNumber) {
346  return Header.getFile(Directory, FileName, FileNumber);
347 }
348 
350  StringRef &FileName,
351  unsigned FileNumber) {
352  if (Directory == CompilationDir)
353  Directory = "";
354  if (FileName.empty()) {
355  FileName = "<stdin>";
356  Directory = "";
357  }
358  assert(!FileName.empty());
359  if (FileNumber == 0) {
360  FileNumber = SourceIdMap.size() + 1;
361  assert((MCDwarfFiles.empty() || FileNumber == MCDwarfFiles.size()) &&
362  "Don't mix autonumbered and explicit numbered line table usage");
363  SmallString<256> Buffer;
364  auto IterBool = SourceIdMap.insert(
365  std::make_pair((Directory + Twine('\0') + FileName).toStringRef(Buffer),
366  FileNumber));
367  if (!IterBool.second)
368  return IterBool.first->second;
369  }
370  // Make space for this FileNumber in the MCDwarfFiles vector if needed.
371  MCDwarfFiles.resize(FileNumber + 1);
372 
373  // Get the new MCDwarfFile slot for this FileNumber.
374  MCDwarfFile &File = MCDwarfFiles[FileNumber];
375 
376  // It is an error to use see the same number more than once.
377  if (!File.Name.empty())
378  return 0;
379 
380  if (Directory.empty()) {
381  // Separate the directory part from the basename of the FileName.
382  StringRef tFileName = sys::path::filename(FileName);
383  if (!tFileName.empty()) {
384  Directory = sys::path::parent_path(FileName);
385  if (!Directory.empty())
386  FileName = tFileName;
387  }
388  }
389 
390  // Find or make an entry in the MCDwarfDirs vector for this Directory.
391  // Capture directory name.
392  unsigned DirIndex;
393  if (Directory.empty()) {
394  // For FileNames with no directories a DirIndex of 0 is used.
395  DirIndex = 0;
396  } else {
397  DirIndex = 0;
398  for (unsigned End = MCDwarfDirs.size(); DirIndex < End; DirIndex++) {
399  if (Directory == MCDwarfDirs[DirIndex])
400  break;
401  }
402  if (DirIndex >= MCDwarfDirs.size())
403  MCDwarfDirs.push_back(Directory);
404  // The DirIndex is one based, as DirIndex of 0 is used for FileNames with
405  // no directories. MCDwarfDirs[] is unlike MCDwarfFiles[] in that the
406  // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames
407  // are stored at MCDwarfFiles[FileNumber].Name .
408  DirIndex++;
409  }
410 
411  File.Name = FileName;
412  File.DirIndex = DirIndex;
413 
414  // return the allocated FileNumber.
415  return FileNumber;
416 }
417 
418 /// Utility function to emit the encoding to a streamer.
419 void MCDwarfLineAddr::Emit(MCStreamer *MCOS, int64_t LineDelta,
420  uint64_t AddrDelta) {
421  MCContext &Context = MCOS->getContext();
422  SmallString<256> Tmp;
423  raw_svector_ostream OS(Tmp);
424  MCDwarfLineAddr::Encode(Context, LineDelta, AddrDelta, OS);
425  MCOS->EmitBytes(OS.str());
426 }
427 
428 /// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas.
429 void MCDwarfLineAddr::Encode(MCContext &Context, int64_t LineDelta,
430  uint64_t AddrDelta, raw_ostream &OS) {
431  uint64_t Temp, Opcode;
432  bool NeedCopy = false;
433 
434  // Scale the address delta by the minimum instruction length.
435  AddrDelta = ScaleAddrDelta(Context, AddrDelta);
436 
437  // A LineDelta of INT64_MAX is a signal that this is actually a
438  // DW_LNE_end_sequence. We cannot use special opcodes here, since we want the
439  // end_sequence to emit the matrix entry.
440  if (LineDelta == INT64_MAX) {
441  if (AddrDelta == MAX_SPECIAL_ADDR_DELTA)
442  OS << char(dwarf::DW_LNS_const_add_pc);
443  else if (AddrDelta) {
444  OS << char(dwarf::DW_LNS_advance_pc);
445  encodeULEB128(AddrDelta, OS);
446  }
447  OS << char(dwarf::DW_LNS_extended_op);
448  OS << char(1);
449  OS << char(dwarf::DW_LNE_end_sequence);
450  return;
451  }
452 
453  // Bias the line delta by the base.
454  Temp = LineDelta - DWARF2_LINE_BASE;
455 
456  // If the line increment is out of range of a special opcode, we must encode
457  // it with DW_LNS_advance_line.
458  if (Temp >= DWARF2_LINE_RANGE) {
459  OS << char(dwarf::DW_LNS_advance_line);
460  encodeSLEB128(LineDelta, OS);
461 
462  LineDelta = 0;
463  Temp = 0 - DWARF2_LINE_BASE;
464  NeedCopy = true;
465  }
466 
467  // Use DW_LNS_copy instead of a "line +0, addr +0" special opcode.
468  if (LineDelta == 0 && AddrDelta == 0) {
469  OS << char(dwarf::DW_LNS_copy);
470  return;
471  }
472 
473  // Bias the opcode by the special opcode base.
474  Temp += DWARF2_LINE_OPCODE_BASE;
475 
476  // Avoid overflow when addr_delta is large.
477  if (AddrDelta < 256 + MAX_SPECIAL_ADDR_DELTA) {
478  // Try using a special opcode.
479  Opcode = Temp + AddrDelta * DWARF2_LINE_RANGE;
480  if (Opcode <= 255) {
481  OS << char(Opcode);
482  return;
483  }
484 
485  // Try using DW_LNS_const_add_pc followed by special op.
486  Opcode = Temp + (AddrDelta - MAX_SPECIAL_ADDR_DELTA) * DWARF2_LINE_RANGE;
487  if (Opcode <= 255) {
488  OS << char(dwarf::DW_LNS_const_add_pc);
489  OS << char(Opcode);
490  return;
491  }
492  }
493 
494  // Otherwise use DW_LNS_advance_pc.
495  OS << char(dwarf::DW_LNS_advance_pc);
496  encodeULEB128(AddrDelta, OS);
497 
498  if (NeedCopy)
499  OS << char(dwarf::DW_LNS_copy);
500  else
501  OS << char(Temp);
502 }
503 
504 // Utility function to write a tuple for .debug_abbrev.
505 static void EmitAbbrev(MCStreamer *MCOS, uint64_t Name, uint64_t Form) {
506  MCOS->EmitULEB128IntValue(Name);
507  MCOS->EmitULEB128IntValue(Form);
508 }
509 
510 // When generating dwarf for assembly source files this emits
511 // the data for .debug_abbrev section which contains three DIEs.
512 static void EmitGenDwarfAbbrev(MCStreamer *MCOS) {
513  MCContext &context = MCOS->getContext();
515 
516  // DW_TAG_compile_unit DIE abbrev (1).
517  MCOS->EmitULEB128IntValue(1);
518  MCOS->EmitULEB128IntValue(dwarf::DW_TAG_compile_unit);
521  if (MCOS->getContext().getGenDwarfSectionSyms().size() > 1 &&
522  MCOS->getContext().getDwarfVersion() >= 3) {
524  } else {
527  }
529  if (!context.getCompilationDir().empty())
531  StringRef DwarfDebugFlags = context.getDwarfDebugFlags();
532  if (!DwarfDebugFlags.empty())
536  EmitAbbrev(MCOS, 0, 0);
537 
538  // DW_TAG_label DIE abbrev (2).
539  MCOS->EmitULEB128IntValue(2);
540  MCOS->EmitULEB128IntValue(dwarf::DW_TAG_label);
547  EmitAbbrev(MCOS, 0, 0);
548 
549  // DW_TAG_unspecified_parameters DIE abbrev (3).
550  MCOS->EmitULEB128IntValue(3);
551  MCOS->EmitULEB128IntValue(dwarf::DW_TAG_unspecified_parameters);
553  EmitAbbrev(MCOS, 0, 0);
554 
555  // Terminate the abbreviations for this compilation unit.
556  MCOS->EmitIntValue(0, 1);
557 }
558 
559 // When generating dwarf for assembly source files this emits the data for
560 // .debug_aranges section. This section contains a header and a table of pairs
561 // of PointerSize'ed values for the address and size of section(s) with line
562 // table entries.
563 static void EmitGenDwarfAranges(MCStreamer *MCOS,
564  const MCSymbol *InfoSectionSymbol) {
565  MCContext &context = MCOS->getContext();
566 
567  auto &Sections = context.getGenDwarfSectionSyms();
568 
570 
571  // This will be the length of the .debug_aranges section, first account for
572  // the size of each item in the header (see below where we emit these items).
573  int Length = 4 + 2 + 4 + 1 + 1;
574 
575  // Figure the padding after the header before the table of address and size
576  // pairs who's values are PointerSize'ed.
577  const MCAsmInfo *asmInfo = context.getAsmInfo();
578  int AddrSize = asmInfo->getPointerSize();
579  int Pad = 2 * AddrSize - (Length & (2 * AddrSize - 1));
580  if (Pad == 2 * AddrSize)
581  Pad = 0;
582  Length += Pad;
583 
584  // Add the size of the pair of PointerSize'ed values for the address and size
585  // of each section we have in the table.
586  Length += 2 * AddrSize * Sections.size();
587  // And the pair of terminating zeros.
588  Length += 2 * AddrSize;
589 
590 
591  // Emit the header for this section.
592  // The 4 byte length not including the 4 byte value for the length.
593  MCOS->EmitIntValue(Length - 4, 4);
594  // The 2 byte version, which is 2.
595  MCOS->EmitIntValue(2, 2);
596  // The 4 byte offset to the compile unit in the .debug_info from the start
597  // of the .debug_info.
598  if (InfoSectionSymbol)
599  MCOS->EmitSymbolValue(InfoSectionSymbol, 4,
601  else
602  MCOS->EmitIntValue(0, 4);
603  // The 1 byte size of an address.
604  MCOS->EmitIntValue(AddrSize, 1);
605  // The 1 byte size of a segment descriptor, we use a value of zero.
606  MCOS->EmitIntValue(0, 1);
607  // Align the header with the padding if needed, before we put out the table.
608  for(int i = 0; i < Pad; i++)
609  MCOS->EmitIntValue(0, 1);
610 
611  // Now emit the table of pairs of PointerSize'ed values for the section
612  // addresses and sizes.
613  for (MCSection *Sec : Sections) {
614  const MCSymbol *StartSymbol = Sec->getBeginSymbol();
615  MCSymbol *EndSymbol = Sec->getEndSymbol(context);
616  assert(StartSymbol && "StartSymbol must not be NULL");
617  assert(EndSymbol && "EndSymbol must not be NULL");
618 
619  const MCExpr *Addr = MCSymbolRefExpr::create(
620  StartSymbol, MCSymbolRefExpr::VK_None, context);
621  const MCExpr *Size = MakeStartMinusEndExpr(*MCOS,
622  *StartSymbol, *EndSymbol, 0);
623  MCOS->EmitValue(Addr, AddrSize);
624  emitAbsValue(*MCOS, Size, AddrSize);
625  }
626 
627  // And finally the pair of terminating zeros.
628  MCOS->EmitIntValue(0, AddrSize);
629  MCOS->EmitIntValue(0, AddrSize);
630 }
631 
632 // When generating dwarf for assembly source files this emits the data for
633 // .debug_info section which contains three parts. The header, the compile_unit
634 // DIE and a list of label DIEs.
635 static void EmitGenDwarfInfo(MCStreamer *MCOS,
636  const MCSymbol *AbbrevSectionSymbol,
637  const MCSymbol *LineSectionSymbol,
638  const MCSymbol *RangesSectionSymbol) {
639  MCContext &context = MCOS->getContext();
640 
642 
643  // Create a symbol at the start and end of this section used in here for the
644  // expression to calculate the length in the header.
645  MCSymbol *InfoStart = context.createTempSymbol();
646  MCOS->EmitLabel(InfoStart);
647  MCSymbol *InfoEnd = context.createTempSymbol();
648 
649  // First part: the header.
650 
651  // The 4 byte total length of the information for this compilation unit, not
652  // including these 4 bytes.
653  const MCExpr *Length = MakeStartMinusEndExpr(*MCOS, *InfoStart, *InfoEnd, 4);
654  emitAbsValue(*MCOS, Length, 4);
655 
656  // The 2 byte DWARF version.
657  MCOS->EmitIntValue(context.getDwarfVersion(), 2);
658 
659  const MCAsmInfo &AsmInfo = *context.getAsmInfo();
660  // The 4 byte offset to the debug abbrevs from the start of the .debug_abbrev,
661  // it is at the start of that section so this is zero.
662  if (AbbrevSectionSymbol == nullptr)
663  MCOS->EmitIntValue(0, 4);
664  else
665  MCOS->EmitSymbolValue(AbbrevSectionSymbol, 4,
667 
668  const MCAsmInfo *asmInfo = context.getAsmInfo();
669  int AddrSize = asmInfo->getPointerSize();
670  // The 1 byte size of an address.
671  MCOS->EmitIntValue(AddrSize, 1);
672 
673  // Second part: the compile_unit DIE.
674 
675  // The DW_TAG_compile_unit DIE abbrev (1).
676  MCOS->EmitULEB128IntValue(1);
677 
678  // DW_AT_stmt_list, a 4 byte offset from the start of the .debug_line section,
679  // which is at the start of that section so this is zero.
680  if (LineSectionSymbol)
681  MCOS->EmitSymbolValue(LineSectionSymbol, 4,
683  else
684  MCOS->EmitIntValue(0, 4);
685 
686  if (RangesSectionSymbol) {
687  // There are multiple sections containing code, so we must use the
688  // .debug_ranges sections.
689 
690  // AT_ranges, the 4 byte offset from the start of the .debug_ranges section
691  // to the address range list for this compilation unit.
692  MCOS->EmitSymbolValue(RangesSectionSymbol, 4);
693  } else {
694  // If we only have one non-empty code section, we can use the simpler
695  // AT_low_pc and AT_high_pc attributes.
696 
697  // Find the first (and only) non-empty text section
698  auto &Sections = context.getGenDwarfSectionSyms();
699  const auto TextSection = Sections.begin();
700  assert(TextSection != Sections.end() && "No text section found");
701 
702  MCSymbol *StartSymbol = (*TextSection)->getBeginSymbol();
703  MCSymbol *EndSymbol = (*TextSection)->getEndSymbol(context);
704  assert(StartSymbol && "StartSymbol must not be NULL");
705  assert(EndSymbol && "EndSymbol must not be NULL");
706 
707  // AT_low_pc, the first address of the default .text section.
708  const MCExpr *Start = MCSymbolRefExpr::create(
709  StartSymbol, MCSymbolRefExpr::VK_None, context);
710  MCOS->EmitValue(Start, AddrSize);
711 
712  // AT_high_pc, the last address of the default .text section.
713  const MCExpr *End = MCSymbolRefExpr::create(
714  EndSymbol, MCSymbolRefExpr::VK_None, context);
715  MCOS->EmitValue(End, AddrSize);
716  }
717 
718  // AT_name, the name of the source file. Reconstruct from the first directory
719  // and file table entries.
720  const SmallVectorImpl<std::string> &MCDwarfDirs = context.getMCDwarfDirs();
721  if (MCDwarfDirs.size() > 0) {
722  MCOS->EmitBytes(MCDwarfDirs[0]);
724  }
725  const SmallVectorImpl<MCDwarfFile> &MCDwarfFiles =
726  MCOS->getContext().getMCDwarfFiles();
727  MCOS->EmitBytes(MCDwarfFiles[1].Name);
728  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
729 
730  // AT_comp_dir, the working directory the assembly was done in.
731  if (!context.getCompilationDir().empty()) {
732  MCOS->EmitBytes(context.getCompilationDir());
733  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
734  }
735 
736  // AT_APPLE_flags, the command line arguments of the assembler tool.
737  StringRef DwarfDebugFlags = context.getDwarfDebugFlags();
738  if (!DwarfDebugFlags.empty()){
739  MCOS->EmitBytes(DwarfDebugFlags);
740  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
741  }
742 
743  // AT_producer, the version of the assembler tool.
744  StringRef DwarfDebugProducer = context.getDwarfDebugProducer();
745  if (!DwarfDebugProducer.empty())
746  MCOS->EmitBytes(DwarfDebugProducer);
747  else
748  MCOS->EmitBytes(StringRef("llvm-mc (based on LLVM " PACKAGE_VERSION ")"));
749  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
750 
751  // AT_language, a 4 byte value. We use DW_LANG_Mips_Assembler as the dwarf2
752  // draft has no standard code for assembler.
753  MCOS->EmitIntValue(dwarf::DW_LANG_Mips_Assembler, 2);
754 
755  // Third part: the list of label DIEs.
756 
757  // Loop on saved info for dwarf labels and create the DIEs for them.
758  const std::vector<MCGenDwarfLabelEntry> &Entries =
760  for (const auto &Entry : Entries) {
761  // The DW_TAG_label DIE abbrev (2).
762  MCOS->EmitULEB128IntValue(2);
763 
764  // AT_name, of the label without any leading underbar.
765  MCOS->EmitBytes(Entry.getName());
766  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
767 
768  // AT_decl_file, index into the file table.
769  MCOS->EmitIntValue(Entry.getFileNumber(), 4);
770 
771  // AT_decl_line, source line number.
772  MCOS->EmitIntValue(Entry.getLineNumber(), 4);
773 
774  // AT_low_pc, start address of the label.
775  const MCExpr *AT_low_pc = MCSymbolRefExpr::create(Entry.getLabel(),
776  MCSymbolRefExpr::VK_None, context);
777  MCOS->EmitValue(AT_low_pc, AddrSize);
778 
779  // DW_AT_prototyped, a one byte flag value of 0 saying we have no prototype.
780  MCOS->EmitIntValue(0, 1);
781 
782  // The DW_TAG_unspecified_parameters DIE abbrev (3).
783  MCOS->EmitULEB128IntValue(3);
784 
785  // Add the NULL DIE terminating the DW_TAG_unspecified_parameters DIE's.
786  MCOS->EmitIntValue(0, 1);
787  }
788 
789  // Add the NULL DIE terminating the Compile Unit DIE's.
790  MCOS->EmitIntValue(0, 1);
791 
792  // Now set the value of the symbol at the end of the info section.
793  MCOS->EmitLabel(InfoEnd);
794 }
795 
796 // When generating dwarf for assembly source files this emits the data for
797 // .debug_ranges section. We only emit one range list, which spans all of the
798 // executable sections of this file.
799 static void EmitGenDwarfRanges(MCStreamer *MCOS) {
800  MCContext &context = MCOS->getContext();
801  auto &Sections = context.getGenDwarfSectionSyms();
802 
803  const MCAsmInfo *AsmInfo = context.getAsmInfo();
804  int AddrSize = AsmInfo->getPointerSize();
805 
807 
808  for (MCSection *Sec : Sections) {
809  const MCSymbol *StartSymbol = Sec->getBeginSymbol();
810  MCSymbol *EndSymbol = Sec->getEndSymbol(context);
811  assert(StartSymbol && "StartSymbol must not be NULL");
812  assert(EndSymbol && "EndSymbol must not be NULL");
813 
814  // Emit a base address selection entry for the start of this section
815  const MCExpr *SectionStartAddr = MCSymbolRefExpr::create(
816  StartSymbol, MCSymbolRefExpr::VK_None, context);
817  MCOS->EmitFill(AddrSize, 0xFF);
818  MCOS->EmitValue(SectionStartAddr, AddrSize);
819 
820  // Emit a range list entry spanning this section
822  *StartSymbol, *EndSymbol, 0);
823  MCOS->EmitIntValue(0, AddrSize);
824  emitAbsValue(*MCOS, SectionSize, AddrSize);
825  }
826 
827  // Emit end of list entry
828  MCOS->EmitIntValue(0, AddrSize);
829  MCOS->EmitIntValue(0, AddrSize);
830 }
831 
832 //
833 // When generating dwarf for assembly source files this emits the Dwarf
834 // sections.
835 //
837  MCContext &context = MCOS->getContext();
838 
839  // Create the dwarf sections in this order (.debug_line already created).
840  const MCAsmInfo *AsmInfo = context.getAsmInfo();
841  bool CreateDwarfSectionSymbols =
843  MCSymbol *LineSectionSymbol = nullptr;
844  if (CreateDwarfSectionSymbols)
845  LineSectionSymbol = MCOS->getDwarfLineTableSymbol(0);
846  MCSymbol *AbbrevSectionSymbol = nullptr;
847  MCSymbol *InfoSectionSymbol = nullptr;
848  MCSymbol *RangesSectionSymbol = NULL;
849 
850  // Create end symbols for each section, and remove empty sections
851  MCOS->getContext().finalizeDwarfSections(*MCOS);
852 
853  // If there are no sections to generate debug info for, we don't need
854  // to do anything
855  if (MCOS->getContext().getGenDwarfSectionSyms().empty())
856  return;
857 
858  // We only use the .debug_ranges section if we have multiple code sections,
859  // and we are emitting a DWARF version which supports it.
860  const bool UseRangesSection =
861  MCOS->getContext().getGenDwarfSectionSyms().size() > 1 &&
862  MCOS->getContext().getDwarfVersion() >= 3;
863  CreateDwarfSectionSymbols |= UseRangesSection;
864 
866  if (CreateDwarfSectionSymbols) {
867  InfoSectionSymbol = context.createTempSymbol();
868  MCOS->EmitLabel(InfoSectionSymbol);
869  }
871  if (CreateDwarfSectionSymbols) {
872  AbbrevSectionSymbol = context.createTempSymbol();
873  MCOS->EmitLabel(AbbrevSectionSymbol);
874  }
875  if (UseRangesSection) {
877  if (CreateDwarfSectionSymbols) {
878  RangesSectionSymbol = context.createTempSymbol();
879  MCOS->EmitLabel(RangesSectionSymbol);
880  }
881  }
882 
883  assert((RangesSectionSymbol != NULL) || !UseRangesSection);
884 
886 
887  // Output the data for .debug_aranges section.
888  EmitGenDwarfAranges(MCOS, InfoSectionSymbol);
889 
890  if (UseRangesSection)
891  EmitGenDwarfRanges(MCOS);
892 
893  // Output the data for .debug_abbrev section.
894  EmitGenDwarfAbbrev(MCOS);
895 
896  // Output the data for .debug_info section.
897  EmitGenDwarfInfo(MCOS, AbbrevSectionSymbol, LineSectionSymbol,
898  RangesSectionSymbol);
899 }
900 
901 //
902 // When generating dwarf for assembly source files this is called when symbol
903 // for a label is created. If this symbol is not a temporary and is in the
904 // section that dwarf is being generated for, save the needed info to create
905 // a dwarf label.
906 //
908  SourceMgr &SrcMgr, SMLoc &Loc) {
909  // We won't create dwarf labels for temporary symbols.
910  if (Symbol->isTemporary())
911  return;
912  MCContext &context = MCOS->getContext();
913  // We won't create dwarf labels for symbols in sections that we are not
914  // generating debug info for.
915  if (!context.getGenDwarfSectionSyms().count(MCOS->getCurrentSection().first))
916  return;
917 
918  // The dwarf label's name does not have the symbol name's leading
919  // underbar if any.
920  StringRef Name = Symbol->getName();
921  if (Name.startswith("_"))
922  Name = Name.substr(1, Name.size()-1);
923 
924  // Get the dwarf file number to be used for the dwarf label.
925  unsigned FileNumber = context.getGenDwarfFileNumber();
926 
927  // Finding the line number is the expensive part which is why we just don't
928  // pass it in as for some symbols we won't create a dwarf label.
929  unsigned CurBuffer = SrcMgr.FindBufferContainingLoc(Loc);
930  unsigned LineNumber = SrcMgr.FindLineNumber(Loc, CurBuffer);
931 
932  // We create a temporary symbol for use for the AT_high_pc and AT_low_pc
933  // values so that they don't have things like an ARM thumb bit from the
934  // original symbol. So when used they won't get a low bit set after
935  // relocation.
936  MCSymbol *Label = context.createTempSymbol();
937  MCOS->EmitLabel(Label);
938 
939  // Create and entry for the info and add it to the other entries.
941  MCGenDwarfLabelEntry(Name, FileNumber, LineNumber, Label));
942 }
943 
944 static int getDataAlignmentFactor(MCStreamer &streamer) {
945  MCContext &context = streamer.getContext();
946  const MCAsmInfo *asmInfo = context.getAsmInfo();
947  int size = asmInfo->getCalleeSaveStackSlotSize();
948  if (asmInfo->isStackGrowthDirectionUp())
949  return size;
950  else
951  return -size;
952 }
953 
954 static unsigned getSizeForEncoding(MCStreamer &streamer,
955  unsigned symbolEncoding) {
956  MCContext &context = streamer.getContext();
957  unsigned format = symbolEncoding & 0x0f;
958  switch (format) {
959  default: llvm_unreachable("Unknown Encoding");
962  return context.getAsmInfo()->getPointerSize();
965  return 2;
968  return 4;
971  return 8;
972  }
973 }
974 
975 static void emitFDESymbol(MCObjectStreamer &streamer, const MCSymbol &symbol,
976  unsigned symbolEncoding, bool isEH) {
977  MCContext &context = streamer.getContext();
978  const MCAsmInfo *asmInfo = context.getAsmInfo();
979  const MCExpr *v = asmInfo->getExprForFDESymbol(&symbol,
980  symbolEncoding,
981  streamer);
982  unsigned size = getSizeForEncoding(streamer, symbolEncoding);
983  if (asmInfo->doDwarfFDESymbolsUseAbsDiff() && isEH)
984  emitAbsValue(streamer, v, size);
985  else
986  streamer.EmitValue(v, size);
987 }
988 
989 static void EmitPersonality(MCStreamer &streamer, const MCSymbol &symbol,
990  unsigned symbolEncoding) {
991  MCContext &context = streamer.getContext();
992  const MCAsmInfo *asmInfo = context.getAsmInfo();
993  const MCExpr *v = asmInfo->getExprForPersonalitySymbol(&symbol,
994  symbolEncoding,
995  streamer);
996  unsigned size = getSizeForEncoding(streamer, symbolEncoding);
997  streamer.EmitValue(v, size);
998 }
999 
1000 namespace {
1001  class FrameEmitterImpl {
1002  int CFAOffset;
1003  int InitialCFAOffset;
1004  bool IsEH;
1005  const MCSymbol *SectionStart;
1006  public:
1007  FrameEmitterImpl(bool isEH)
1008  : CFAOffset(0), InitialCFAOffset(0), IsEH(isEH), SectionStart(nullptr) {
1009  }
1010 
1011  void setSectionStart(const MCSymbol *Label) { SectionStart = Label; }
1012 
1013  /// Emit the unwind information in a compact way.
1014  void EmitCompactUnwind(MCObjectStreamer &streamer,
1015  const MCDwarfFrameInfo &frame);
1016 
1017  const MCSymbol &EmitCIE(MCObjectStreamer &streamer,
1018  const MCSymbol *personality,
1019  unsigned personalityEncoding,
1020  const MCSymbol *lsda,
1021  bool IsSignalFrame,
1022  unsigned lsdaEncoding,
1023  bool IsSimple);
1024  MCSymbol *EmitFDE(MCObjectStreamer &streamer,
1025  const MCSymbol &cieStart,
1026  const MCDwarfFrameInfo &frame);
1027  void EmitCFIInstructions(MCObjectStreamer &streamer,
1029  MCSymbol *BaseLabel);
1030  void EmitCFIInstruction(MCObjectStreamer &Streamer,
1031  const MCCFIInstruction &Instr);
1032  };
1033 
1034 } // end anonymous namespace
1035 
1036 static void emitEncodingByte(MCObjectStreamer &Streamer, unsigned Encoding) {
1037  Streamer.EmitIntValue(Encoding, 1);
1038 }
1039 
1040 void FrameEmitterImpl::EmitCFIInstruction(MCObjectStreamer &Streamer,
1041  const MCCFIInstruction &Instr) {
1042  int dataAlignmentFactor = getDataAlignmentFactor(Streamer);
1043  auto *MRI = Streamer.getContext().getRegisterInfo();
1044 
1045  switch (Instr.getOperation()) {
1047  unsigned Reg1 = Instr.getRegister();
1048  unsigned Reg2 = Instr.getRegister2();
1049  if (!IsEH) {
1050  Reg1 = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg1, true), false);
1051  Reg2 = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg2, true), false);
1052  }
1053  Streamer.EmitIntValue(dwarf::DW_CFA_register, 1);
1054  Streamer.EmitULEB128IntValue(Reg1);
1055  Streamer.EmitULEB128IntValue(Reg2);
1056  return;
1057  }
1060  return;
1061  }
1063  unsigned Reg = Instr.getRegister();
1065  Streamer.EmitULEB128IntValue(Reg);
1066  return;
1067  }
1070  const bool IsRelative =
1072 
1074 
1075  if (IsRelative)
1076  CFAOffset += Instr.getOffset();
1077  else
1078  CFAOffset = -Instr.getOffset();
1079 
1080  Streamer.EmitULEB128IntValue(CFAOffset);
1081 
1082  return;
1083  }
1085  unsigned Reg = Instr.getRegister();
1086  if (!IsEH)
1087  Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false);
1088  Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa, 1);
1089  Streamer.EmitULEB128IntValue(Reg);
1090  CFAOffset = -Instr.getOffset();
1091  Streamer.EmitULEB128IntValue(CFAOffset);
1092 
1093  return;
1094  }
1095 
1097  unsigned Reg = Instr.getRegister();
1098  if (!IsEH)
1099  Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false);
1101  Streamer.EmitULEB128IntValue(Reg);
1102 
1103  return;
1104  }
1105 
1108  const bool IsRelative =
1110 
1111  unsigned Reg = Instr.getRegister();
1112  if (!IsEH)
1113  Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false);
1114 
1115  int Offset = Instr.getOffset();
1116  if (IsRelative)
1117  Offset -= CFAOffset;
1118  Offset = Offset / dataAlignmentFactor;
1119 
1120  if (Offset < 0) {
1122  Streamer.EmitULEB128IntValue(Reg);
1123  Streamer.EmitSLEB128IntValue(Offset);
1124  } else if (Reg < 64) {
1125  Streamer.EmitIntValue(dwarf::DW_CFA_offset + Reg, 1);
1126  Streamer.EmitULEB128IntValue(Offset);
1127  } else {
1129  Streamer.EmitULEB128IntValue(Reg);
1130  Streamer.EmitULEB128IntValue(Offset);
1131  }
1132  return;
1133  }
1136  return;
1139  return;
1141  unsigned Reg = Instr.getRegister();
1143  Streamer.EmitULEB128IntValue(Reg);
1144  return;
1145  }
1147  unsigned Reg = Instr.getRegister();
1148  if (!IsEH)
1149  Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false);
1150  Streamer.EmitIntValue(dwarf::DW_CFA_restore | Reg, 1);
1151  return;
1152  }
1154  Streamer.EmitBytes(Instr.getValues());
1155  return;
1156  }
1157  llvm_unreachable("Unhandled case in switch");
1158 }
1159 
1160 /// Emit frame instructions to describe the layout of the frame.
1161 void FrameEmitterImpl::EmitCFIInstructions(MCObjectStreamer &streamer,
1163  MCSymbol *BaseLabel) {
1164  for (unsigned i = 0, N = Instrs.size(); i < N; ++i) {
1165  const MCCFIInstruction &Instr = Instrs[i];
1166  MCSymbol *Label = Instr.getLabel();
1167  // Throw out move if the label is invalid.
1168  if (Label && !Label->isDefined()) continue; // Not emitted, in dead code.
1169 
1170  // Advance row if new location.
1171  if (BaseLabel && Label) {
1172  MCSymbol *ThisSym = Label;
1173  if (ThisSym != BaseLabel) {
1174  streamer.EmitDwarfAdvanceFrameAddr(BaseLabel, ThisSym);
1175  BaseLabel = ThisSym;
1176  }
1177  }
1178 
1179  EmitCFIInstruction(streamer, Instr);
1180  }
1181 }
1182 
1183 /// Emit the unwind information in a compact way.
1184 void FrameEmitterImpl::EmitCompactUnwind(MCObjectStreamer &Streamer,
1185  const MCDwarfFrameInfo &Frame) {
1186  MCContext &Context = Streamer.getContext();
1187  const MCObjectFileInfo *MOFI = Context.getObjectFileInfo();
1188 
1189  // range-start range-length compact-unwind-enc personality-func lsda
1190  // _foo LfooEnd-_foo 0x00000023 0 0
1191  // _bar LbarEnd-_bar 0x00000025 __gxx_personality except_tab1
1192  //
1193  // .section __LD,__compact_unwind,regular,debug
1194  //
1195  // # compact unwind for _foo
1196  // .quad _foo
1197  // .set L1,LfooEnd-_foo
1198  // .long L1
1199  // .long 0x01010001
1200  // .quad 0
1201  // .quad 0
1202  //
1203  // # compact unwind for _bar
1204  // .quad _bar
1205  // .set L2,LbarEnd-_bar
1206  // .long L2
1207  // .long 0x01020011
1208  // .quad __gxx_personality
1209  // .quad except_tab1
1210 
1211  uint32_t Encoding = Frame.CompactUnwindEncoding;
1212  if (!Encoding) return;
1213  bool DwarfEHFrameOnly = (Encoding == MOFI->getCompactUnwindDwarfEHFrameOnly());
1214 
1215  // The encoding needs to know we have an LSDA.
1216  if (!DwarfEHFrameOnly && Frame.Lsda)
1217  Encoding |= 0x40000000;
1218 
1219  // Range Start
1220  unsigned FDEEncoding = MOFI->getFDEEncoding();
1221  unsigned Size = getSizeForEncoding(Streamer, FDEEncoding);
1222  Streamer.EmitSymbolValue(Frame.Begin, Size);
1223 
1224  // Range Length
1225  const MCExpr *Range = MakeStartMinusEndExpr(Streamer, *Frame.Begin,
1226  *Frame.End, 0);
1227  emitAbsValue(Streamer, Range, 4);
1228 
1229  // Compact Encoding
1230  Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_udata4);
1231  Streamer.EmitIntValue(Encoding, Size);
1232 
1233  // Personality Function
1234  Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_absptr);
1235  if (!DwarfEHFrameOnly && Frame.Personality)
1236  Streamer.EmitSymbolValue(Frame.Personality, Size);
1237  else
1238  Streamer.EmitIntValue(0, Size); // No personality fn
1239 
1240  // LSDA
1241  Size = getSizeForEncoding(Streamer, Frame.LsdaEncoding);
1242  if (!DwarfEHFrameOnly && Frame.Lsda)
1243  Streamer.EmitSymbolValue(Frame.Lsda, Size);
1244  else
1245  Streamer.EmitIntValue(0, Size); // No LSDA
1246 }
1247 
1248 static unsigned getCIEVersion(bool IsEH, unsigned DwarfVersion) {
1249  if (IsEH)
1250  return 1;
1251  switch (DwarfVersion) {
1252  case 2:
1253  return 1;
1254  case 3:
1255  return 3;
1256  case 4:
1257  return 4;
1258  }
1259  llvm_unreachable("Unknown version");
1260 }
1261 
1262 const MCSymbol &FrameEmitterImpl::EmitCIE(MCObjectStreamer &streamer,
1263  const MCSymbol *personality,
1264  unsigned personalityEncoding,
1265  const MCSymbol *lsda,
1266  bool IsSignalFrame,
1267  unsigned lsdaEncoding,
1268  bool IsSimple) {
1269  MCContext &context = streamer.getContext();
1270  const MCRegisterInfo *MRI = context.getRegisterInfo();
1271  const MCObjectFileInfo *MOFI = context.getObjectFileInfo();
1272 
1273  MCSymbol *sectionStart = context.createTempSymbol();
1274  streamer.EmitLabel(sectionStart);
1275 
1276  MCSymbol *sectionEnd = context.createTempSymbol();
1277 
1278  // Length
1279  const MCExpr *Length = MakeStartMinusEndExpr(streamer, *sectionStart,
1280  *sectionEnd, 4);
1281  emitAbsValue(streamer, Length, 4);
1282 
1283  // CIE ID
1284  unsigned CIE_ID = IsEH ? 0 : -1;
1285  streamer.EmitIntValue(CIE_ID, 4);
1286 
1287  // Version
1288  uint8_t CIEVersion = getCIEVersion(IsEH, context.getDwarfVersion());
1289  streamer.EmitIntValue(CIEVersion, 1);
1290 
1291  // Augmentation String
1292  SmallString<8> Augmentation;
1293  if (IsEH) {
1294  Augmentation += "z";
1295  if (personality)
1296  Augmentation += "P";
1297  if (lsda)
1298  Augmentation += "L";
1299  Augmentation += "R";
1300  if (IsSignalFrame)
1301  Augmentation += "S";
1302  streamer.EmitBytes(Augmentation);
1303  }
1304  streamer.EmitIntValue(0, 1);
1305 
1306  if (CIEVersion >= 4) {
1307  // Address Size
1308  streamer.EmitIntValue(context.getAsmInfo()->getPointerSize(), 1);
1309 
1310  // Segment Descriptor Size
1311  streamer.EmitIntValue(0, 1);
1312  }
1313 
1314  // Code Alignment Factor
1315  streamer.EmitULEB128IntValue(context.getAsmInfo()->getMinInstAlignment());
1316 
1317  // Data Alignment Factor
1318  streamer.EmitSLEB128IntValue(getDataAlignmentFactor(streamer));
1319 
1320  // Return Address Register
1321  if (CIEVersion == 1) {
1322  assert(MRI->getRARegister() <= 255 &&
1323  "DWARF 2 encodes return_address_register in one byte");
1324  streamer.EmitIntValue(MRI->getDwarfRegNum(MRI->getRARegister(), IsEH), 1);
1325  } else {
1326  streamer.EmitULEB128IntValue(
1327  MRI->getDwarfRegNum(MRI->getRARegister(), IsEH));
1328  }
1329 
1330  // Augmentation Data Length (optional)
1331 
1332  unsigned augmentationLength = 0;
1333  if (IsEH) {
1334  if (personality) {
1335  // Personality Encoding
1336  augmentationLength += 1;
1337  // Personality
1338  augmentationLength += getSizeForEncoding(streamer, personalityEncoding);
1339  }
1340  if (lsda)
1341  augmentationLength += 1;
1342  // Encoding of the FDE pointers
1343  augmentationLength += 1;
1344 
1345  streamer.EmitULEB128IntValue(augmentationLength);
1346 
1347  // Augmentation Data (optional)
1348  if (personality) {
1349  // Personality Encoding
1350  emitEncodingByte(streamer, personalityEncoding);
1351  // Personality
1352  EmitPersonality(streamer, *personality, personalityEncoding);
1353  }
1354 
1355  if (lsda)
1356  emitEncodingByte(streamer, lsdaEncoding);
1357 
1358  // Encoding of the FDE pointers
1359  emitEncodingByte(streamer, MOFI->getFDEEncoding());
1360  }
1361 
1362  // Initial Instructions
1363 
1364  const MCAsmInfo *MAI = context.getAsmInfo();
1365  if (!IsSimple) {
1366  const std::vector<MCCFIInstruction> &Instructions =
1367  MAI->getInitialFrameState();
1368  EmitCFIInstructions(streamer, Instructions, nullptr);
1369  }
1370 
1371  InitialCFAOffset = CFAOffset;
1372 
1373  // Padding
1374  streamer.EmitValueToAlignment(IsEH ? 4 : MAI->getPointerSize());
1375 
1376  streamer.EmitLabel(sectionEnd);
1377  return *sectionStart;
1378 }
1379 
1380 MCSymbol *FrameEmitterImpl::EmitFDE(MCObjectStreamer &streamer,
1381  const MCSymbol &cieStart,
1382  const MCDwarfFrameInfo &frame) {
1383  MCContext &context = streamer.getContext();
1384  MCSymbol *fdeStart = context.createTempSymbol();
1385  MCSymbol *fdeEnd = context.createTempSymbol();
1386  const MCObjectFileInfo *MOFI = context.getObjectFileInfo();
1387 
1388  CFAOffset = InitialCFAOffset;
1389 
1390  // Length
1391  const MCExpr *Length = MakeStartMinusEndExpr(streamer, *fdeStart, *fdeEnd, 0);
1392  emitAbsValue(streamer, Length, 4);
1393 
1394  streamer.EmitLabel(fdeStart);
1395 
1396  // CIE Pointer
1397  const MCAsmInfo *asmInfo = context.getAsmInfo();
1398  if (IsEH) {
1399  const MCExpr *offset = MakeStartMinusEndExpr(streamer, cieStart, *fdeStart,
1400  0);
1401  emitAbsValue(streamer, offset, 4);
1402  } else if (!asmInfo->doesDwarfUseRelocationsAcrossSections()) {
1403  const MCExpr *offset = MakeStartMinusEndExpr(streamer, *SectionStart,
1404  cieStart, 0);
1405  emitAbsValue(streamer, offset, 4);
1406  } else {
1407  streamer.EmitSymbolValue(&cieStart, 4);
1408  }
1409 
1410  // PC Begin
1411  unsigned PCEncoding =
1413  unsigned PCSize = getSizeForEncoding(streamer, PCEncoding);
1414  emitFDESymbol(streamer, *frame.Begin, PCEncoding, IsEH);
1415 
1416  // PC Range
1417  const MCExpr *Range = MakeStartMinusEndExpr(streamer, *frame.Begin,
1418  *frame.End, 0);
1419  emitAbsValue(streamer, Range, PCSize);
1420 
1421  if (IsEH) {
1422  // Augmentation Data Length
1423  unsigned augmentationLength = 0;
1424 
1425  if (frame.Lsda)
1426  augmentationLength += getSizeForEncoding(streamer, frame.LsdaEncoding);
1427 
1428  streamer.EmitULEB128IntValue(augmentationLength);
1429 
1430  // Augmentation Data
1431  if (frame.Lsda)
1432  emitFDESymbol(streamer, *frame.Lsda, frame.LsdaEncoding, true);
1433  }
1434 
1435  // Call Frame Instructions
1436  EmitCFIInstructions(streamer, frame.Instructions, frame.Begin);
1437 
1438  // Padding
1439  streamer.EmitValueToAlignment(PCSize);
1440 
1441  return fdeEnd;
1442 }
1443 
1444 namespace {
1445  struct CIEKey {
1446  static const CIEKey getEmptyKey() {
1447  return CIEKey(nullptr, 0, -1, false, false);
1448  }
1449  static const CIEKey getTombstoneKey() {
1450  return CIEKey(nullptr, -1, 0, false, false);
1451  }
1452 
1453  CIEKey(const MCSymbol *Personality_, unsigned PersonalityEncoding_,
1454  unsigned LsdaEncoding_, bool IsSignalFrame_, bool IsSimple_)
1455  : Personality(Personality_), PersonalityEncoding(PersonalityEncoding_),
1456  LsdaEncoding(LsdaEncoding_), IsSignalFrame(IsSignalFrame_),
1457  IsSimple(IsSimple_) {}
1458  const MCSymbol *Personality;
1459  unsigned PersonalityEncoding;
1460  unsigned LsdaEncoding;
1461  bool IsSignalFrame;
1462  bool IsSimple;
1463  };
1464 }
1465 
1466 namespace llvm {
1467  template <>
1468  struct DenseMapInfo<CIEKey> {
1469  static CIEKey getEmptyKey() {
1470  return CIEKey::getEmptyKey();
1471  }
1472  static CIEKey getTombstoneKey() {
1473  return CIEKey::getTombstoneKey();
1474  }
1475  static unsigned getHashValue(const CIEKey &Key) {
1476  return static_cast<unsigned>(hash_combine(Key.Personality,
1477  Key.PersonalityEncoding,
1478  Key.LsdaEncoding,
1479  Key.IsSignalFrame,
1480  Key.IsSimple));
1481  }
1482  static bool isEqual(const CIEKey &LHS,
1483  const CIEKey &RHS) {
1484  return LHS.Personality == RHS.Personality &&
1485  LHS.PersonalityEncoding == RHS.PersonalityEncoding &&
1486  LHS.LsdaEncoding == RHS.LsdaEncoding &&
1487  LHS.IsSignalFrame == RHS.IsSignalFrame &&
1488  LHS.IsSimple == RHS.IsSimple;
1489  }
1490  };
1491 }
1492 
1494  bool IsEH) {
1495  Streamer.generateCompactUnwindEncodings(MAB);
1496 
1497  MCContext &Context = Streamer.getContext();
1498  const MCObjectFileInfo *MOFI = Context.getObjectFileInfo();
1499  FrameEmitterImpl Emitter(IsEH);
1500  ArrayRef<MCDwarfFrameInfo> FrameArray = Streamer.getDwarfFrameInfos();
1501 
1502  // Emit the compact unwind info if available.
1503  bool NeedsEHFrameSection = !MOFI->getSupportsCompactUnwindWithoutEHFrame();
1504  if (IsEH && MOFI->getCompactUnwindSection()) {
1505  bool SectionEmitted = false;
1506  for (unsigned i = 0, n = FrameArray.size(); i < n; ++i) {
1507  const MCDwarfFrameInfo &Frame = FrameArray[i];
1508  if (Frame.CompactUnwindEncoding == 0) continue;
1509  if (!SectionEmitted) {
1510  Streamer.SwitchSection(MOFI->getCompactUnwindSection());
1511  Streamer.EmitValueToAlignment(Context.getAsmInfo()->getPointerSize());
1512  SectionEmitted = true;
1513  }
1514  NeedsEHFrameSection |=
1515  Frame.CompactUnwindEncoding ==
1517  Emitter.EmitCompactUnwind(Streamer, Frame);
1518  }
1519  }
1520 
1521  if (!NeedsEHFrameSection) return;
1522 
1523  MCSection &Section =
1524  IsEH ? *const_cast<MCObjectFileInfo *>(MOFI)->getEHFrameSection()
1525  : *MOFI->getDwarfFrameSection();
1526 
1527  Streamer.SwitchSection(&Section);
1528  MCSymbol *SectionStart = Context.createTempSymbol();
1529  Streamer.EmitLabel(SectionStart);
1530  Emitter.setSectionStart(SectionStart);
1531 
1532  MCSymbol *FDEEnd = nullptr;
1534 
1535  const MCSymbol *DummyDebugKey = nullptr;
1536  NeedsEHFrameSection = !MOFI->getSupportsCompactUnwindWithoutEHFrame();
1537  for (unsigned i = 0, n = FrameArray.size(); i < n; ++i) {
1538  const MCDwarfFrameInfo &Frame = FrameArray[i];
1539 
1540  // Emit the label from the previous iteration
1541  if (FDEEnd) {
1542  Streamer.EmitLabel(FDEEnd);
1543  FDEEnd = nullptr;
1544  }
1545 
1546  if (!NeedsEHFrameSection && Frame.CompactUnwindEncoding !=
1548  // Don't generate an EH frame if we don't need one. I.e., it's taken care
1549  // of by the compact unwind encoding.
1550  continue;
1551 
1552  CIEKey Key(Frame.Personality, Frame.PersonalityEncoding,
1553  Frame.LsdaEncoding, Frame.IsSignalFrame, Frame.IsSimple);
1554  const MCSymbol *&CIEStart = IsEH ? CIEStarts[Key] : DummyDebugKey;
1555  if (!CIEStart)
1556  CIEStart = &Emitter.EmitCIE(Streamer, Frame.Personality,
1557  Frame.PersonalityEncoding, Frame.Lsda,
1558  Frame.IsSignalFrame,
1559  Frame.LsdaEncoding,
1560  Frame.IsSimple);
1561 
1562  FDEEnd = Emitter.EmitFDE(Streamer, *CIEStart, Frame);
1563  }
1564 
1565  Streamer.EmitValueToAlignment(Context.getAsmInfo()->getPointerSize());
1566  if (FDEEnd)
1567  Streamer.EmitLabel(FDEEnd);
1568 }
1569 
1571  uint64_t AddrDelta) {
1572  MCContext &Context = Streamer.getContext();
1573  SmallString<256> Tmp;
1574  raw_svector_ostream OS(Tmp);
1575  MCDwarfFrameEmitter::EncodeAdvanceLoc(Context, AddrDelta, OS);
1576  Streamer.EmitBytes(OS.str());
1577 }
1578 
1580  uint64_t AddrDelta,
1581  raw_ostream &OS) {
1582  // Scale the address delta by the minimum instruction length.
1583  AddrDelta = ScaleAddrDelta(Context, AddrDelta);
1584 
1585  if (AddrDelta == 0) {
1586  } else if (isUIntN(6, AddrDelta)) {
1587  uint8_t Opcode = dwarf::DW_CFA_advance_loc | AddrDelta;
1588  OS << Opcode;
1589  } else if (isUInt<8>(AddrDelta)) {
1590  OS << uint8_t(dwarf::DW_CFA_advance_loc1);
1591  OS << uint8_t(AddrDelta);
1592  } else if (isUInt<16>(AddrDelta)) {
1593  OS << uint8_t(dwarf::DW_CFA_advance_loc2);
1594  if (Context.getAsmInfo()->isLittleEndian())
1595  support::endian::Writer<support::little>(OS).write<uint16_t>(AddrDelta);
1596  else
1597  support::endian::Writer<support::big>(OS).write<uint16_t>(AddrDelta);
1598  } else {
1599  assert(isUInt<32>(AddrDelta));
1600  OS << uint8_t(dwarf::DW_CFA_advance_loc4);
1601  if (Context.getAsmInfo()->isLittleEndian())
1602  support::endian::Writer<support::little>(OS).write<uint32_t>(AddrDelta);
1603  else
1604  support::endian::Writer<support::big>(OS).write<uint32_t>(AddrDelta);
1605  }
1606 }
static const MCExpr * forceExpAbs(MCStreamer &OS, const MCExpr *Expr)
Definition: MCDwarf.cpp:242
bool isUInt< 8 >(uint64_t x)
Definition: MathExtras.h:294
void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry &E)
Definition: MCContext.h:481
Instances of this class represent a uniqued identifier for a section in the current translation unit...
Definition: MCSection.h:48
void push_back(const T &Elt)
Definition: SmallVector.h:222
static void Emit(MCStreamer *MCOS, int64_t LineDelta, uint64_t AddrDelta)
Utility function to emit the encoding to a streamer.
Definition: MCDwarf.cpp:419
int getDwarfRegNum(unsigned RegNum, bool isEH) const
Map a target register to an equivalent dwarf register number.
const MCAsmInfo * getAsmInfo() const
Definition: MCContext.h:225
unsigned getFDEEncoding() const
static int getDataAlignmentFactor(MCStreamer &streamer)
Definition: MCDwarf.cpp:944
void EmitBytes(StringRef Data) override
Emit the bytes in Data into the output.
static CIEKey getTombstoneKey()
Definition: MCDwarf.cpp:1472
#define DWARF2_FLAG_PROLOGUE_END
Definition: MCDwarf.h:70
static const MCSymbolRefExpr * create(const MCSymbol *Symbol, MCContext &Ctx)
Definition: MCExpr.h:315
void EmitSLEB128IntValue(int64_t Value)
Special case of EmitSLEB128Value that avoids the client having to pass in a MCExpr for constant integ...
Definition: MCStreamer.cpp:103
size_t size() const
size - Get the string size.
Definition: StringRef.h:113
void EmitSymbolValue(const MCSymbol *Sym, unsigned Size, bool IsSectionRelative=false)
Special case of EmitValue that avoids the client having to pass in a MCExpr for MCSymbols.
Definition: MCStreamer.cpp:115
void EmitLabel(MCSymbol *Symbol) override
Emit a label for Symbol into the current section.
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:39
void write(value_type Val)
Definition: EndianStream.h:29
void Emit(MCStreamer &MCOS) const
Definition: MCDwarf.cpp:218
const SmallVectorImpl< MCDwarfFile > & getMCDwarfFiles(unsigned CUID=0)
Definition: MCContext.h:423
SourceMgr SrcMgr
virtual void EmitBytes(StringRef Data)
Emit the bytes in Data into the output.
Definition: MCStreamer.cpp:681
#define DWARF2_LINE_BASE
Definition: MCDwarf.cpp:46
StringRef substr(size_t Start, size_t N=npos) const
Return a reference to the substring from [Start, Start + N).
Definition: StringRef.h:405
static void EmitAdvanceLoc(MCObjectStreamer &Streamer, uint64_t AddrDelta)
Definition: MCDwarf.cpp:1570
A raw_ostream that writes to an SmallVector or SmallString.
Definition: raw_ostream.h:488
ArrayRef< MCDwarfFrameInfo > getDwarfFrameInfos() const
Definition: MCStreamer.h:217
virtual MCSymbol * getDwarfLineTableSymbol(unsigned CUID)
Definition: MCStreamer.cpp:162
static void EmitGenDwarfInfo(MCStreamer *MCOS, const MCSymbol *AbbrevSectionSymbol, const MCSymbol *LineSectionSymbol, const MCSymbol *RangesSectionSymbol)
Definition: MCDwarf.cpp:635
uint16_t getDwarfVersion() const
Definition: MCContext.h:492
unsigned LsdaEncoding
Definition: MCDwarf.h:483
StringRef getDwarfDebugFlags()
Definition: MCContext.h:486
void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel, const MCSymbol *Label, unsigned PointerSize)
unsigned getRegister() const
Definition: MCDwarf.h:444
std::vector< MCCFIInstruction > Instructions
Definition: MCDwarf.h:480
static void Encode(MCContext &Context, int64_t LineDelta, uint64_t AddrDelta, raw_ostream &OS)
Utility function to encode a Dwarf pair of LineDelta and AddrDeltas.
Definition: MCDwarf.cpp:429
static const MCBinaryExpr * create(Opcode Op, const MCExpr *LHS, const MCExpr *RHS, MCContext &Ctx)
Definition: MCExpr.cpp:140
virtual const MCExpr * getExprForPersonalitySymbol(const MCSymbol *Sym, unsigned Encoding, MCStreamer &Streamer) const
Definition: MCAsmInfo.cpp:121
int getOffset() const
Definition: MCDwarf.h:457
#define DWARF2_FLAG_IS_STMT
Definition: MCDwarf.h:68
StringRef getDwarfDebugProducer()
Definition: MCContext.h:489
bool getSupportsCompactUnwindWithoutEHFrame() const
std::string Name
Definition: MCDwarf.h:48
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:79
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Definition: ErrorHandling.h:98
MCSectionSubPair getCurrentSection() const
Return the current section that the streamer is emitting code to.
Definition: MCStreamer.h:274
void EmitCU(MCObjectStreamer *MCOS) const
Definition: MCDwarf.cpp:332
void finalizeDwarfSections(MCStreamer &MCOS)
Remove empty sections from SectionStartEndSyms, to avoid generating useless debug info for them...
Definition: MCContext.cpp:469
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:33
MCSymbol * Begin
Definition: MCDwarf.h:476
Reg
All possible values of the reg field in the ModR/M byte.
const std::vector< MCCFIInstruction > & getInitialFrameState() const
Definition: MCAsmInfo.h:538
const MCSymbol * Lsda
Definition: MCDwarf.h:479
static void emitFDESymbol(MCObjectStreamer &streamer, const MCSymbol &symbol, unsigned symbolEncoding, bool isEH)
Definition: MCDwarf.cpp:975
MCDwarfLineTable & getMCDwarfLineTable(unsigned CUID)
Definition: MCContext.h:413
MCContext & getContext() const
Definition: MCStreamer.h:210
bool isLittleEndian() const
True if the target is little endian.
Definition: MCAsmInfo.h:376
const SmallVectorImpl< std::string > & getMCDwarfDirs(unsigned CUID=0)
Definition: MCContext.h:426
virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value)
Emit an assignment of Value to Symbol.
Definition: MCStreamer.cpp:596
Context object for machine code objects.
Definition: MCContext.h:48
StringRef getValues() const
Definition: MCDwarf.h:464
static void EmitGenDwarfAbbrev(MCStreamer *MCOS)
Definition: MCDwarf.cpp:512
#define MAX_SPECIAL_ADDR_DELTA
Definition: MCDwarf.cpp:37
unsigned getDwarfCompileUnitID()
Definition: MCContext.h:436
Streaming object file generation interface.
Instances of this class represent the information from a dwarf .loc directive.
Definition: MCDwarf.h:56
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: ArrayRef.h:31
unsigned getGenDwarfFileNumber()
Definition: MCContext.h:466
virtual void EmitIntValue(uint64_t Value, unsigned Size)
Special case of EmitValue that avoids the client having to pass in a MCExpr for constant integers...
Definition: MCStreamer.cpp:79
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:134
#define DWARF2_LINE_RANGE
Definition: MCDwarf.cpp:49
MCRegisterInfo base class - We assume that the target defines a static array of MCRegisterDesc object...
format_object< Ts...> format(const char *Fmt, const Ts &...Vals)
These are helper functions used to produce formatted output.
Definition: Format.h:111
LLVM_CONSTEXPR size_t array_lengthof(T(&)[N])
Find the length of an array.
Definition: STLExtras.h:247
This class is intended to be used as a base class for asm properties and features specific to the tar...
Definition: MCAsmInfo.h:58
MCSection * getDwarfLineSection() const
bool needsDwarfSectionOffsetDirective() const
Definition: MCAsmInfo.h:425
static unsigned getSizeForEncoding(MCStreamer &streamer, unsigned symbolEncoding)
Definition: MCDwarf.cpp:954
StringRef filename(StringRef path)
Get filename.
Definition: Path.cpp:548
Streaming machine code generation interface.
Definition: MCStreamer.h:157
static unsigned getCIEVersion(bool IsEH, unsigned DwarfVersion)
Definition: MCDwarf.cpp:1248
MCSection * getCompactUnwindSection() const
static void EmitAbbrev(MCStreamer *MCOS, uint64_t Name, uint64_t Form)
Definition: MCDwarf.cpp:505
MCSymbol * createTempSymbol(bool CanBeUnnamed=true)
Create and return a new assembler temporary symbol with a unique but unspecified name.
Definition: MCContext.cpp:222
virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue)
Emit NumBytes bytes worth of the value specified by FillValue.
Definition: MCStreamer.cpp:136
#define DWARF2_FLAG_EPILOGUE_BEGIN
Definition: MCDwarf.h:71
virtual void SwitchSection(MCSection *Section, const MCExpr *Subsection=nullptr)
Set the current section where code is being emitted to Section.
Definition: MCStreamer.cpp:701
static void emitAbsValue(MCStreamer &OS, const MCExpr *Value, unsigned Size)
Definition: MCDwarf.cpp:253
unsigned size() const
Definition: StringMap.h:99
static void EmitGenDwarfAranges(MCStreamer *MCOS, const MCSymbol *InfoSectionSymbol)
Definition: MCDwarf.cpp:563
cl::opt< int > DwarfVersion("dwarf-version", cl::desc("Dwarf version"), cl::init(0))
unsigned getFile(StringRef &Directory, StringRef &FileName, unsigned FileNumber=0)
Definition: MCDwarf.cpp:349
#define DWARF2_FLAG_BASIC_BLOCK
Definition: MCDwarf.h:69
const MCDwarfLoc & getCurrentDwarfLoc()
Definition: MCContext.h:462
unsigned PersonalityEncoding
Definition: MCDwarf.h:482
This owns the files read by a parser, handles include stacks, and handles diagnostic wrangling...
Definition: SourceMgr.h:35
std::vector< MCLineEntry > MCLineEntryCollection
Definition: MCDwarf.h:169
void generateCompactUnwindEncodings(MCAsmBackend *MAB)
Definition: MCStreamer.cpp:71
#define DWARF2_LINE_OPCODE_BASE
Definition: MCDwarf.cpp:42
void clearDwarfLocSeen()
Definition: MCContext.h:459
unsigned getULEB128Size(uint64_t Value)
Utility function to get the size of the ULEB128-encoded value.
Definition: LEB128.cpp:20
void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value=0, unsigned ValueSize=1, unsigned MaxBytesToEmit=0) override
Emit some number of copies of Value until the byte alignment ByteAlignment is reached.
unsigned getPointerSize() const
Get the pointer size in bytes.
Definition: MCAsmInfo.h:367
const SetVector< MCSection * > & getGenDwarfSectionSyms()
Definition: MCContext.h:470
OpType getOperation() const
Definition: MCDwarf.h:441
bool isDefined() const
isDefined - Check if this symbol is defined (i.e., it has an address).
Definition: MCSymbol.h:251
bool startswith(StringRef Prefix) const
Check if this string starts with the given Prefix.
Definition: StringRef.h:215
unsigned getMinInstAlignment() const
Definition: MCAsmInfo.h:437
void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, const MCSymbol *Label)
bool doDwarfFDESymbolsUseAbsDiff() const
Definition: MCAsmInfo.h:530
static unsigned getHashValue(const CIEKey &Key)
Definition: MCDwarf.cpp:1475
virtual void EmitLabel(MCSymbol *Symbol)
Emit a label for Symbol into the current section.
Definition: MCStreamer.cpp:203
static bool isEqual(const CIEKey &LHS, const CIEKey &RHS)
Definition: MCDwarf.cpp:1482
static void EmitDwarfLineTable(MCObjectStreamer *MCOS, MCSection *Section, const MCLineSection::MCLineEntryCollection &LineEntries)
Definition: MCDwarf.cpp:118
unsigned getRegister2() const
Definition: MCDwarf.h:452
static void EncodeAdvanceLoc(MCContext &Context, uint64_t AddrDelta, raw_ostream &OS)
Definition: MCDwarf.cpp:1579
uint32_t CompactUnwindEncoding
Definition: MCDwarf.h:484
static void EmitGenDwarfRanges(MCStreamer *MCOS)
Definition: MCDwarf.cpp:799
bool getDwarfLocSeen()
Definition: MCContext.h:461
bool insert(MapEntryTy *KeyValue)
insert - Insert the specified key/value pair into the map.
Definition: StringMap.h:298
void encodeSLEB128(int64_t Value, raw_ostream &OS)
Utility function to encode a SLEB128 value to an output stream.
Definition: LEB128.h:23
const std::vector< MCGenDwarfLabelEntry > & getMCGenDwarfLabelEntries() const
Definition: MCContext.h:478
bool isUInt< 32 >(uint64_t x)
Definition: MathExtras.h:302
StringRef parent_path(StringRef path)
Get parent path.
Definition: Path.cpp:490
static CIEKey getEmptyKey()
Definition: MCDwarf.cpp:1469
unsigned FindLineNumber(SMLoc Loc, unsigned BufferID=0) const
Find the line number for the specified location in the specified file.
Definition: SourceMgr.h:148
hash_code hash_combine(const Ts &...args)
Combine values into a single hash_code.
Definition: Hashing.h:603
StringRef get_separator()
Return the preferred separator for this platform.
Definition: Path.cpp:590
bool isTemporary() const
isTemporary - Check if this is an assembler temporary symbol.
Definition: MCSymbol.h:222
static void Emit(MCStreamer *MCOS)
Definition: MCDwarf.cpp:836
#define DWARF2_LINE_DEFAULT_IS_STMT
Definition: MCDwarf.h:66
static StringRef toStringRef(bool B)
Construct a string ref from a boolean.
Definition: StringExtras.h:32
static uint64_t ScaleAddrDelta(MCContext &Context, uint64_t AddrDelta)
Definition: MCDwarf.cpp:51
const MCRegisterInfo * getRegisterInfo() const
Definition: MCContext.h:227
StringRef str()
Flushes the stream contents to the target vector and return a StringRef for the vector contents...
StringRef getCompilationDir() const
Get the compilation directory for DW_AT_comp_dir This can be overridden by clients which want to cont...
Definition: MCContext.h:389
MCSection * getDwarfARangesSection() const
Adapter to write values to a stream in a particular byte order.
Definition: EndianStream.h:26
static const MCExpr * MakeStartMinusEndExpr(const MCStreamer &MCOS, const MCSymbol &Start, const MCSymbol &End, int IntVal)
Definition: MCDwarf.cpp:95
Instances of this class represent the line information for the dwarf line table entries.
Definition: MCDwarf.h:138
StringRef getName() const
getName - Get the symbol name.
Definition: MCSymbol.h:205
StringMap< unsigned > SourceIdMap
Definition: MCDwarf.h:189
static void EmitPersonality(MCStreamer &streamer, const MCSymbol &symbol, unsigned symbolEncoding)
Definition: MCDwarf.cpp:989
static void Make(MCSymbol *Symbol, MCStreamer *MCOS, SourceMgr &SrcMgr, SMLoc &Loc)
Definition: MCDwarf.cpp:907
const std::map< unsigned, MCDwarfLineTable > & getMCDwarfLineTables() const
Definition: MCContext.h:409
const MCSymbol * Personality
Definition: MCDwarf.h:478
bool isStackGrowthDirectionUp() const
True if target stack grow up.
Definition: MCAsmInfo.h:379
MCSection * getDwarfFrameSection() const
#define N
static void Make(MCObjectStreamer *MCOS, MCSection *Section)
Definition: MCDwarf.cpp:67
void size_t size
std::pair< MCSymbol *, MCSymbol * > Emit(MCStreamer *MCOS) const
Definition: MCDwarf.cpp:222
unsigned getCalleeSaveStackSlotSize() const
Get the callee-saved register stack slot size in bytes.
Definition: MCAsmInfo.h:371
const MCLineDivisionMap & getMCLineEntries() const
Definition: MCDwarf.h:180
bool hasAggressiveSymbolFolding() const
Definition: MCAsmInfo.h:480
void EmitValue(const MCExpr *Value, unsigned Size, const SMLoc &Loc=SMLoc())
Definition: MCStreamer.cpp:110
void EmitULEB128IntValue(uint64_t Value, unsigned Padding=0)
Special case of EmitULEB128Value that avoids the client having to pass in a MCExpr for constant integ...
Definition: MCStreamer.cpp:94
MCSymbol * endSection(MCSection *Section)
Definition: MCStreamer.cpp:715
unsigned DirIndex
Definition: MCDwarf.h:51
unsigned FindBufferContainingLoc(SMLoc Loc) const
Return the ID of the buffer containing the specified location.
Definition: SourceMgr.cpp:66
MCGenDwarfLabelEntry(StringRef name, unsigned fileNumber, unsigned lineNumber, MCSymbol *label)
Definition: MCDwarf.h:295
virtual const MCExpr * getExprForFDESymbol(const MCSymbol *Sym, unsigned Encoding, MCStreamer &Streamer) const
Definition: MCAsmInfo.cpp:128
LLVM Value Representation.
Definition: Value.h:69
Generic interface to target specific assembler backends.
Definition: MCAsmBackend.h:34
const MCObjectFileInfo * getObjectFileInfo() const
Definition: MCContext.h:229
MCSection * getDwarfInfoSection() const
MCSection * getDwarfRangesSection() const
bool isUInt< 16 >(uint64_t x)
Definition: MathExtras.h:298
unsigned getCompactUnwindDwarfEHFrameOnly() const
static void emitEncodingByte(MCObjectStreamer &Streamer, unsigned Encoding)
Definition: MCDwarf.cpp:1036
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:38
SmallVector< MCDwarfFile, 3 > MCDwarfFiles
Definition: MCDwarf.h:188
void encodeULEB128(uint64_t Value, raw_ostream &OS, unsigned Padding=0)
Utility function to encode a ULEB128 value to an output stream.
Definition: LEB128.h:38
Subtraction.
Definition: MCExpr.h:429
static void Emit(MCObjectStreamer &streamer, MCAsmBackend *MAB, bool isEH)
Definition: MCDwarf.cpp:1493
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:40
Instances of this class represent the name of the dwarf .file directive and its associated dwarf file...
Definition: MCDwarf.h:45
unsigned getRARegister() const
This method should return the register where the return address can be found.
MCSection * getDwarfAbbrevSection() const
Represents a location in source code.
Definition: SMLoc.h:23
unsigned getFile(StringRef &Directory, StringRef &FileName, unsigned FileNumber=0)
Definition: MCDwarf.cpp:344
bool isUIntN(unsigned N, uint64_t x)
isUIntN - Checks if an unsigned integer fits into the given (dynamic) bit width.
Definition: MathExtras.h:315
MCSymbol * getLabel() const
Definition: MCDwarf.h:442
SmallVector< std::string, 3 > MCDwarfDirs
Definition: MCDwarf.h:187
static const MCConstantExpr * create(int64_t Value, MCContext &Ctx)
Definition: MCExpr.cpp:150
bool doesDwarfUseRelocationsAcrossSections() const
Definition: MCAsmInfo.h:527
bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:110
static void Emit(MCObjectStreamer *MCOS)
Definition: MCDwarf.cpp:200