LLVM  4.0.0
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"
27 #include "llvm/Support/LEB128.h"
28 #include "llvm/Support/Path.h"
29 #include "llvm/Support/SourceMgr.h"
31 
32 using namespace llvm;
33 
34 static inline uint64_t ScaleAddrDelta(MCContext &Context, uint64_t AddrDelta) {
35  unsigned MinInsnLength = Context.getAsmInfo()->getMinInstAlignment();
36  if (MinInsnLength == 1)
37  return AddrDelta;
38  if (AddrDelta % MinInsnLength != 0) {
39  // TODO: report this error, but really only once.
40  ;
41  }
42  return AddrDelta / MinInsnLength;
43 }
44 
45 //
46 // This is called when an instruction is assembled into the specified section
47 // and if there is information from the last .loc directive that has yet to have
48 // a line entry made for it is made.
49 //
51  if (!MCOS->getContext().getDwarfLocSeen())
52  return;
53 
54  // Create a symbol at in the current section for use in the line entry.
55  MCSymbol *LineSym = MCOS->getContext().createTempSymbol();
56  // Set the value of the symbol to use for the MCDwarfLineEntry.
57  MCOS->EmitLabel(LineSym);
58 
59  // Get the current .loc info saved in the context.
60  const MCDwarfLoc &DwarfLoc = MCOS->getContext().getCurrentDwarfLoc();
61 
62  // Create a (local) line entry with the symbol and the current .loc info.
63  MCDwarfLineEntry LineEntry(LineSym, DwarfLoc);
64 
65  // clear DwarfLocSeen saying the current .loc info is now used.
66  MCOS->getContext().clearDwarfLocSeen();
67 
68  // Add the line entry to this section's entries.
69  MCOS->getContext()
71  .getMCLineSections()
72  .addLineEntry(LineEntry, Section);
73 }
74 
75 //
76 // This helper routine returns an expression of End - Start + IntVal .
77 //
78 static inline const MCExpr *MakeStartMinusEndExpr(const MCStreamer &MCOS,
79  const MCSymbol &Start,
80  const MCSymbol &End,
81  int IntVal) {
83  const MCExpr *Res =
84  MCSymbolRefExpr::create(&End, Variant, MCOS.getContext());
85  const MCExpr *RHS =
86  MCSymbolRefExpr::create(&Start, Variant, MCOS.getContext());
87  const MCExpr *Res1 =
89  const MCExpr *Res2 =
90  MCConstantExpr::create(IntVal, MCOS.getContext());
91  const MCExpr *Res3 =
93  return Res3;
94 }
95 
96 //
97 // This emits the Dwarf line table for the specified section from the entries
98 // in the LineSection.
99 //
100 static inline void
102  const MCLineSection::MCDwarfLineEntryCollection &LineEntries) {
103  unsigned FileNum = 1;
104  unsigned LastLine = 1;
105  unsigned Column = 0;
107  unsigned Isa = 0;
108  unsigned Discriminator = 0;
109  MCSymbol *LastLabel = nullptr;
110 
111  // Loop through each MCDwarfLineEntry and encode the dwarf line number table.
112  for (const MCDwarfLineEntry &LineEntry : LineEntries) {
113  int64_t LineDelta = static_cast<int64_t>(LineEntry.getLine()) - LastLine;
114 
115  if (FileNum != LineEntry.getFileNum()) {
116  FileNum = LineEntry.getFileNum();
117  MCOS->EmitIntValue(dwarf::DW_LNS_set_file, 1);
118  MCOS->EmitULEB128IntValue(FileNum);
119  }
120  if (Column != LineEntry.getColumn()) {
121  Column = LineEntry.getColumn();
122  MCOS->EmitIntValue(dwarf::DW_LNS_set_column, 1);
123  MCOS->EmitULEB128IntValue(Column);
124  }
125  if (Discriminator != LineEntry.getDiscriminator() &&
126  MCOS->getContext().getDwarfVersion() >= 4) {
127  Discriminator = LineEntry.getDiscriminator();
128  unsigned Size = getULEB128Size(Discriminator);
129  MCOS->EmitIntValue(dwarf::DW_LNS_extended_op, 1);
130  MCOS->EmitULEB128IntValue(Size + 1);
131  MCOS->EmitIntValue(dwarf::DW_LNE_set_discriminator, 1);
132  MCOS->EmitULEB128IntValue(Discriminator);
133  }
134  if (Isa != LineEntry.getIsa()) {
135  Isa = LineEntry.getIsa();
136  MCOS->EmitIntValue(dwarf::DW_LNS_set_isa, 1);
137  MCOS->EmitULEB128IntValue(Isa);
138  }
139  if ((LineEntry.getFlags() ^ Flags) & DWARF2_FLAG_IS_STMT) {
140  Flags = LineEntry.getFlags();
141  MCOS->EmitIntValue(dwarf::DW_LNS_negate_stmt, 1);
142  }
143  if (LineEntry.getFlags() & DWARF2_FLAG_BASIC_BLOCK)
144  MCOS->EmitIntValue(dwarf::DW_LNS_set_basic_block, 1);
145  if (LineEntry.getFlags() & DWARF2_FLAG_PROLOGUE_END)
146  MCOS->EmitIntValue(dwarf::DW_LNS_set_prologue_end, 1);
147  if (LineEntry.getFlags() & DWARF2_FLAG_EPILOGUE_BEGIN)
148  MCOS->EmitIntValue(dwarf::DW_LNS_set_epilogue_begin, 1);
149 
150  MCSymbol *Label = LineEntry.getLabel();
151 
152  // At this point we want to emit/create the sequence to encode the delta in
153  // line numbers and the increment of the address from the previous Label
154  // and the current Label.
155  const MCAsmInfo *asmInfo = MCOS->getContext().getAsmInfo();
156  MCOS->EmitDwarfAdvanceLineAddr(LineDelta, LastLabel, Label,
157  asmInfo->getPointerSize());
158 
159  Discriminator = 0;
160  LastLine = LineEntry.getLine();
161  LastLabel = Label;
162  }
163 
164  // Emit a DW_LNE_end_sequence for the end of the section.
165  // Use the section end label to compute the address delta and use INT64_MAX
166  // as the line delta which is the signal that this is actually a
167  // DW_LNE_end_sequence.
168  MCSymbol *SectionEnd = MCOS->endSection(Section);
169 
170  // Switch back the dwarf line section, in case endSection had to switch the
171  // section.
172  MCContext &Ctx = MCOS->getContext();
174 
175  const MCAsmInfo *AsmInfo = Ctx.getAsmInfo();
176  MCOS->EmitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, SectionEnd,
177  AsmInfo->getPointerSize());
178 }
179 
180 //
181 // This emits the Dwarf file and the line tables.
182 //
184  MCDwarfLineTableParams Params) {
185  MCContext &context = MCOS->getContext();
186 
187  auto &LineTables = context.getMCDwarfLineTables();
188 
189  // Bail out early so we don't switch to the debug_line section needlessly and
190  // in doing so create an unnecessary (if empty) section.
191  if (LineTables.empty())
192  return;
193 
194  // Switch to the section where the table will be emitted into.
196 
197  // Handle the rest of the Compile Units.
198  for (const auto &CUIDTablePair : LineTables)
199  CUIDTablePair.second.EmitCU(MCOS, Params);
200 }
201 
203  MCDwarfLineTableParams Params) const {
204  MCOS.EmitLabel(Header.Emit(&MCOS, Params, None).second);
205 }
206 
207 std::pair<MCSymbol *, MCSymbol *>
209  MCDwarfLineTableParams Params) const {
210  static const char StandardOpcodeLengths[] = {
211  0, // length of DW_LNS_copy
212  1, // length of DW_LNS_advance_pc
213  1, // length of DW_LNS_advance_line
214  1, // length of DW_LNS_set_file
215  1, // length of DW_LNS_set_column
216  0, // length of DW_LNS_negate_stmt
217  0, // length of DW_LNS_set_basic_block
218  0, // length of DW_LNS_const_add_pc
219  1, // length of DW_LNS_fixed_advance_pc
220  0, // length of DW_LNS_set_prologue_end
221  0, // length of DW_LNS_set_epilogue_begin
222  1 // DW_LNS_set_isa
223  };
224  assert(array_lengthof(StandardOpcodeLengths) >=
225  (Params.DWARF2LineOpcodeBase - 1U));
226  return Emit(MCOS, Params, makeArrayRef(StandardOpcodeLengths,
227  Params.DWARF2LineOpcodeBase - 1));
228 }
229 
230 static const MCExpr *forceExpAbs(MCStreamer &OS, const MCExpr* Expr) {
231  MCContext &Context = OS.getContext();
232  assert(!isa<MCSymbolRefExpr>(Expr));
233  if (Context.getAsmInfo()->hasAggressiveSymbolFolding())
234  return Expr;
235 
236  MCSymbol *ABS = Context.createTempSymbol();
237  OS.EmitAssignment(ABS, Expr);
238  return MCSymbolRefExpr::create(ABS, Context);
239 }
240 
241 static void emitAbsValue(MCStreamer &OS, const MCExpr *Value, unsigned Size) {
242  const MCExpr *ABS = forceExpAbs(OS, Value);
243  OS.EmitValue(ABS, Size);
244 }
245 
246 std::pair<MCSymbol *, MCSymbol *>
248  ArrayRef<char> StandardOpcodeLengths) const {
249  MCContext &context = MCOS->getContext();
250 
251  // Create a symbol at the beginning of the line table.
252  MCSymbol *LineStartSym = Label;
253  if (!LineStartSym)
254  LineStartSym = context.createTempSymbol();
255  // Set the value of the symbol, as we are at the start of the line table.
256  MCOS->EmitLabel(LineStartSym);
257 
258  // Create a symbol for the end of the section (to be set when we get there).
259  MCSymbol *LineEndSym = context.createTempSymbol();
260 
261  // The first 4 bytes is the total length of the information for this
262  // compilation unit (not including these 4 bytes for the length).
263  emitAbsValue(*MCOS,
264  MakeStartMinusEndExpr(*MCOS, *LineStartSym, *LineEndSym, 4), 4);
265 
266  // Next 2 bytes is the Version, which is Dwarf 2.
267  MCOS->EmitIntValue(2, 2);
268 
269  // Create a symbol for the end of the prologue (to be set when we get there).
270  MCSymbol *ProEndSym = context.createTempSymbol(); // Lprologue_end
271 
272  // Length of the prologue, is the next 4 bytes. Which is the start of the
273  // section to the end of the prologue. Not including the 4 bytes for the
274  // total length, the 2 bytes for the version, and these 4 bytes for the
275  // length of the prologue.
276  emitAbsValue(
277  *MCOS,
278  MakeStartMinusEndExpr(*MCOS, *LineStartSym, *ProEndSym, (4 + 2 + 4)), 4);
279 
280  // Parameters of the state machine, are next.
281  MCOS->EmitIntValue(context.getAsmInfo()->getMinInstAlignment(), 1);
283  MCOS->EmitIntValue(Params.DWARF2LineBase, 1);
284  MCOS->EmitIntValue(Params.DWARF2LineRange, 1);
285  MCOS->EmitIntValue(StandardOpcodeLengths.size() + 1, 1);
286 
287  // Standard opcode lengths
288  for (char Length : StandardOpcodeLengths)
289  MCOS->EmitIntValue(Length, 1);
290 
291  // Put out the directory and file tables.
292 
293  // First the directory table.
294  for (unsigned i = 0; i < MCDwarfDirs.size(); i++) {
295  MCOS->EmitBytes(MCDwarfDirs[i]); // the DirectoryName
296  MCOS->EmitBytes(StringRef("\0", 1)); // the null term. of the string
297  }
298  MCOS->EmitIntValue(0, 1); // Terminate the directory list
299 
300  // Second the file table.
301  for (unsigned i = 1; i < MCDwarfFiles.size(); i++) {
302  assert(!MCDwarfFiles[i].Name.empty());
303  MCOS->EmitBytes(MCDwarfFiles[i].Name); // FileName
304  MCOS->EmitBytes(StringRef("\0", 1)); // the null term. of the string
305  // the Directory num
306  MCOS->EmitULEB128IntValue(MCDwarfFiles[i].DirIndex);
307  MCOS->EmitIntValue(0, 1); // last modification timestamp (always 0)
308  MCOS->EmitIntValue(0, 1); // filesize (always 0)
309  }
310  MCOS->EmitIntValue(0, 1); // Terminate the file list
311 
312  // This is the end of the prologue, so set the value of the symbol at the
313  // end of the prologue (that was used in a previous expression).
314  MCOS->EmitLabel(ProEndSym);
315 
316  return std::make_pair(LineStartSym, LineEndSym);
317 }
318 
320  MCDwarfLineTableParams Params) const {
321  MCSymbol *LineEndSym = Header.Emit(MCOS, Params).second;
322 
323  // Put out the line tables.
324  for (const auto &LineSec : MCLineSections.getMCLineEntries())
325  EmitDwarfLineTable(MCOS, LineSec.first, LineSec.second);
326 
327  // This is the end of the section, so set the value of the symbol at the end
328  // of this section (that was used in a previous expression).
329  MCOS->EmitLabel(LineEndSym);
330 }
331 
332 unsigned MCDwarfLineTable::getFile(StringRef &Directory, StringRef &FileName,
333  unsigned FileNumber) {
334  return Header.getFile(Directory, FileName, FileNumber);
335 }
336 
338  StringRef &FileName,
339  unsigned FileNumber) {
340  if (Directory == CompilationDir)
341  Directory = "";
342  if (FileName.empty()) {
343  FileName = "<stdin>";
344  Directory = "";
345  }
346  assert(!FileName.empty());
347  if (FileNumber == 0) {
348  // File numbers start with 1 and/or after any file numbers
349  // allocated by inline-assembler .file directives.
350  FileNumber = MCDwarfFiles.empty() ? 1 : MCDwarfFiles.size();
351  SmallString<256> Buffer;
352  auto IterBool = SourceIdMap.insert(
353  std::make_pair((Directory + Twine('\0') + FileName).toStringRef(Buffer),
354  FileNumber));
355  if (!IterBool.second)
356  return IterBool.first->second;
357  }
358  // Make space for this FileNumber in the MCDwarfFiles vector if needed.
359  MCDwarfFiles.resize(FileNumber + 1);
360 
361  // Get the new MCDwarfFile slot for this FileNumber.
362  MCDwarfFile &File = MCDwarfFiles[FileNumber];
363 
364  // It is an error to use see the same number more than once.
365  if (!File.Name.empty())
366  return 0;
367 
368  if (Directory.empty()) {
369  // Separate the directory part from the basename of the FileName.
370  StringRef tFileName = sys::path::filename(FileName);
371  if (!tFileName.empty()) {
372  Directory = sys::path::parent_path(FileName);
373  if (!Directory.empty())
374  FileName = tFileName;
375  }
376  }
377 
378  // Find or make an entry in the MCDwarfDirs vector for this Directory.
379  // Capture directory name.
380  unsigned DirIndex;
381  if (Directory.empty()) {
382  // For FileNames with no directories a DirIndex of 0 is used.
383  DirIndex = 0;
384  } else {
385  DirIndex = 0;
386  for (unsigned End = MCDwarfDirs.size(); DirIndex < End; DirIndex++) {
387  if (Directory == MCDwarfDirs[DirIndex])
388  break;
389  }
390  if (DirIndex >= MCDwarfDirs.size())
391  MCDwarfDirs.push_back(Directory);
392  // The DirIndex is one based, as DirIndex of 0 is used for FileNames with
393  // no directories. MCDwarfDirs[] is unlike MCDwarfFiles[] in that the
394  // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames
395  // are stored at MCDwarfFiles[FileNumber].Name .
396  DirIndex++;
397  }
398 
399  File.Name = FileName;
400  File.DirIndex = DirIndex;
401 
402  // return the allocated FileNumber.
403  return FileNumber;
404 }
405 
406 /// Utility function to emit the encoding to a streamer.
408  int64_t LineDelta, uint64_t AddrDelta) {
409  MCContext &Context = MCOS->getContext();
410  SmallString<256> Tmp;
411  raw_svector_ostream OS(Tmp);
412  MCDwarfLineAddr::Encode(Context, Params, LineDelta, AddrDelta, OS);
413  MCOS->EmitBytes(OS.str());
414 }
415 
416 /// Given a special op, return the address skip amount (in units of
417 /// DWARF2_LINE_MIN_INSN_LENGTH).
418 static uint64_t SpecialAddr(MCDwarfLineTableParams Params, uint64_t op) {
419  return (op - Params.DWARF2LineOpcodeBase) / Params.DWARF2LineRange;
420 }
421 
422 /// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas.
424  int64_t LineDelta, uint64_t AddrDelta,
425  raw_ostream &OS) {
426  uint64_t Temp, Opcode;
427  bool NeedCopy = false;
428 
429  // The maximum address skip amount that can be encoded with a special op.
430  uint64_t MaxSpecialAddrDelta = SpecialAddr(Params, 255);
431 
432  // Scale the address delta by the minimum instruction length.
433  AddrDelta = ScaleAddrDelta(Context, AddrDelta);
434 
435  // A LineDelta of INT64_MAX is a signal that this is actually a
436  // DW_LNE_end_sequence. We cannot use special opcodes here, since we want the
437  // end_sequence to emit the matrix entry.
438  if (LineDelta == INT64_MAX) {
439  if (AddrDelta == MaxSpecialAddrDelta)
440  OS << char(dwarf::DW_LNS_const_add_pc);
441  else if (AddrDelta) {
442  OS << char(dwarf::DW_LNS_advance_pc);
443  encodeULEB128(AddrDelta, OS);
444  }
445  OS << char(dwarf::DW_LNS_extended_op);
446  OS << char(1);
447  OS << char(dwarf::DW_LNE_end_sequence);
448  return;
449  }
450 
451  // Bias the line delta by the base.
452  Temp = LineDelta - Params.DWARF2LineBase;
453 
454  // If the line increment is out of range of a special opcode, we must encode
455  // it with DW_LNS_advance_line.
456  if (Temp >= Params.DWARF2LineRange ||
457  Temp + Params.DWARF2LineOpcodeBase > 255) {
458  OS << char(dwarf::DW_LNS_advance_line);
459  encodeSLEB128(LineDelta, OS);
460 
461  LineDelta = 0;
462  Temp = 0 - Params.DWARF2LineBase;
463  NeedCopy = true;
464  }
465 
466  // Use DW_LNS_copy instead of a "line +0, addr +0" special opcode.
467  if (LineDelta == 0 && AddrDelta == 0) {
468  OS << char(dwarf::DW_LNS_copy);
469  return;
470  }
471 
472  // Bias the opcode by the special opcode base.
473  Temp += Params.DWARF2LineOpcodeBase;
474 
475  // Avoid overflow when addr_delta is large.
476  if (AddrDelta < 256 + MaxSpecialAddrDelta) {
477  // Try using a special opcode.
478  Opcode = Temp + AddrDelta * Params.DWARF2LineRange;
479  if (Opcode <= 255) {
480  OS << char(Opcode);
481  return;
482  }
483 
484  // Try using DW_LNS_const_add_pc followed by special op.
485  Opcode = Temp + (AddrDelta - MaxSpecialAddrDelta) * Params.DWARF2LineRange;
486  if (Opcode <= 255) {
487  OS << char(dwarf::DW_LNS_const_add_pc);
488  OS << char(Opcode);
489  return;
490  }
491  }
492 
493  // Otherwise use DW_LNS_advance_pc.
494  OS << char(dwarf::DW_LNS_advance_pc);
495  encodeULEB128(AddrDelta, OS);
496 
497  if (NeedCopy)
498  OS << char(dwarf::DW_LNS_copy);
499  else {
500  assert(Temp <= 255 && "Buggy special opcode encoding.");
501  OS << char(Temp);
502  }
503 }
504 
505 // Utility function to write a tuple for .debug_abbrev.
506 static void EmitAbbrev(MCStreamer *MCOS, uint64_t Name, uint64_t Form) {
507  MCOS->EmitULEB128IntValue(Name);
508  MCOS->EmitULEB128IntValue(Form);
509 }
510 
511 // When generating dwarf for assembly source files this emits
512 // the data for .debug_abbrev section which contains three DIEs.
513 static void EmitGenDwarfAbbrev(MCStreamer *MCOS) {
514  MCContext &context = MCOS->getContext();
516 
517  // DW_TAG_compile_unit DIE abbrev (1).
518  MCOS->EmitULEB128IntValue(1);
519  MCOS->EmitULEB128IntValue(dwarf::DW_TAG_compile_unit);
521  EmitAbbrev(MCOS, dwarf::DW_AT_stmt_list, context.getDwarfVersion() >= 4
522  ? dwarf::DW_FORM_sec_offset
523  : dwarf::DW_FORM_data4);
524  if (context.getGenDwarfSectionSyms().size() > 1 &&
525  context.getDwarfVersion() >= 3) {
526  EmitAbbrev(MCOS, dwarf::DW_AT_ranges, context.getDwarfVersion() >= 4
527  ? dwarf::DW_FORM_sec_offset
528  : dwarf::DW_FORM_data4);
529  } else {
530  EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr);
531  EmitAbbrev(MCOS, dwarf::DW_AT_high_pc, dwarf::DW_FORM_addr);
532  }
533  EmitAbbrev(MCOS, dwarf::DW_AT_name, dwarf::DW_FORM_string);
534  if (!context.getCompilationDir().empty())
535  EmitAbbrev(MCOS, dwarf::DW_AT_comp_dir, dwarf::DW_FORM_string);
536  StringRef DwarfDebugFlags = context.getDwarfDebugFlags();
537  if (!DwarfDebugFlags.empty())
538  EmitAbbrev(MCOS, dwarf::DW_AT_APPLE_flags, dwarf::DW_FORM_string);
539  EmitAbbrev(MCOS, dwarf::DW_AT_producer, dwarf::DW_FORM_string);
540  EmitAbbrev(MCOS, dwarf::DW_AT_language, dwarf::DW_FORM_data2);
541  EmitAbbrev(MCOS, 0, 0);
542 
543  // DW_TAG_label DIE abbrev (2).
544  MCOS->EmitULEB128IntValue(2);
545  MCOS->EmitULEB128IntValue(dwarf::DW_TAG_label);
547  EmitAbbrev(MCOS, dwarf::DW_AT_name, dwarf::DW_FORM_string);
548  EmitAbbrev(MCOS, dwarf::DW_AT_decl_file, dwarf::DW_FORM_data4);
549  EmitAbbrev(MCOS, dwarf::DW_AT_decl_line, dwarf::DW_FORM_data4);
550  EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr);
551  EmitAbbrev(MCOS, dwarf::DW_AT_prototyped, dwarf::DW_FORM_flag);
552  EmitAbbrev(MCOS, 0, 0);
553 
554  // DW_TAG_unspecified_parameters DIE abbrev (3).
555  MCOS->EmitULEB128IntValue(3);
556  MCOS->EmitULEB128IntValue(dwarf::DW_TAG_unspecified_parameters);
558  EmitAbbrev(MCOS, 0, 0);
559 
560  // Terminate the abbreviations for this compilation unit.
561  MCOS->EmitIntValue(0, 1);
562 }
563 
564 // When generating dwarf for assembly source files this emits the data for
565 // .debug_aranges section. This section contains a header and a table of pairs
566 // of PointerSize'ed values for the address and size of section(s) with line
567 // table entries.
568 static void EmitGenDwarfAranges(MCStreamer *MCOS,
569  const MCSymbol *InfoSectionSymbol) {
570  MCContext &context = MCOS->getContext();
571 
572  auto &Sections = context.getGenDwarfSectionSyms();
573 
575 
576  // This will be the length of the .debug_aranges section, first account for
577  // the size of each item in the header (see below where we emit these items).
578  int Length = 4 + 2 + 4 + 1 + 1;
579 
580  // Figure the padding after the header before the table of address and size
581  // pairs who's values are PointerSize'ed.
582  const MCAsmInfo *asmInfo = context.getAsmInfo();
583  int AddrSize = asmInfo->getPointerSize();
584  int Pad = 2 * AddrSize - (Length & (2 * AddrSize - 1));
585  if (Pad == 2 * AddrSize)
586  Pad = 0;
587  Length += Pad;
588 
589  // Add the size of the pair of PointerSize'ed values for the address and size
590  // of each section we have in the table.
591  Length += 2 * AddrSize * Sections.size();
592  // And the pair of terminating zeros.
593  Length += 2 * AddrSize;
594 
595 
596  // Emit the header for this section.
597  // The 4 byte length not including the 4 byte value for the length.
598  MCOS->EmitIntValue(Length - 4, 4);
599  // The 2 byte version, which is 2.
600  MCOS->EmitIntValue(2, 2);
601  // The 4 byte offset to the compile unit in the .debug_info from the start
602  // of the .debug_info.
603  if (InfoSectionSymbol)
604  MCOS->EmitSymbolValue(InfoSectionSymbol, 4,
606  else
607  MCOS->EmitIntValue(0, 4);
608  // The 1 byte size of an address.
609  MCOS->EmitIntValue(AddrSize, 1);
610  // The 1 byte size of a segment descriptor, we use a value of zero.
611  MCOS->EmitIntValue(0, 1);
612  // Align the header with the padding if needed, before we put out the table.
613  for(int i = 0; i < Pad; i++)
614  MCOS->EmitIntValue(0, 1);
615 
616  // Now emit the table of pairs of PointerSize'ed values for the section
617  // addresses and sizes.
618  for (MCSection *Sec : Sections) {
619  const MCSymbol *StartSymbol = Sec->getBeginSymbol();
620  MCSymbol *EndSymbol = Sec->getEndSymbol(context);
621  assert(StartSymbol && "StartSymbol must not be NULL");
622  assert(EndSymbol && "EndSymbol must not be NULL");
623 
624  const MCExpr *Addr = MCSymbolRefExpr::create(
625  StartSymbol, MCSymbolRefExpr::VK_None, context);
626  const MCExpr *Size = MakeStartMinusEndExpr(*MCOS,
627  *StartSymbol, *EndSymbol, 0);
628  MCOS->EmitValue(Addr, AddrSize);
629  emitAbsValue(*MCOS, Size, AddrSize);
630  }
631 
632  // And finally the pair of terminating zeros.
633  MCOS->EmitIntValue(0, AddrSize);
634  MCOS->EmitIntValue(0, AddrSize);
635 }
636 
637 // When generating dwarf for assembly source files this emits the data for
638 // .debug_info section which contains three parts. The header, the compile_unit
639 // DIE and a list of label DIEs.
640 static void EmitGenDwarfInfo(MCStreamer *MCOS,
641  const MCSymbol *AbbrevSectionSymbol,
642  const MCSymbol *LineSectionSymbol,
643  const MCSymbol *RangesSectionSymbol) {
644  MCContext &context = MCOS->getContext();
645 
647 
648  // Create a symbol at the start and end of this section used in here for the
649  // expression to calculate the length in the header.
650  MCSymbol *InfoStart = context.createTempSymbol();
651  MCOS->EmitLabel(InfoStart);
652  MCSymbol *InfoEnd = context.createTempSymbol();
653 
654  // First part: the header.
655 
656  // The 4 byte total length of the information for this compilation unit, not
657  // including these 4 bytes.
658  const MCExpr *Length = MakeStartMinusEndExpr(*MCOS, *InfoStart, *InfoEnd, 4);
659  emitAbsValue(*MCOS, Length, 4);
660 
661  // The 2 byte DWARF version.
662  MCOS->EmitIntValue(context.getDwarfVersion(), 2);
663 
664  const MCAsmInfo &AsmInfo = *context.getAsmInfo();
665  // The 4 byte offset to the debug abbrevs from the start of the .debug_abbrev,
666  // it is at the start of that section so this is zero.
667  if (AbbrevSectionSymbol == nullptr)
668  MCOS->EmitIntValue(0, 4);
669  else
670  MCOS->EmitSymbolValue(AbbrevSectionSymbol, 4,
672 
673  const MCAsmInfo *asmInfo = context.getAsmInfo();
674  int AddrSize = asmInfo->getPointerSize();
675  // The 1 byte size of an address.
676  MCOS->EmitIntValue(AddrSize, 1);
677 
678  // Second part: the compile_unit DIE.
679 
680  // The DW_TAG_compile_unit DIE abbrev (1).
681  MCOS->EmitULEB128IntValue(1);
682 
683  // DW_AT_stmt_list, a 4 byte offset from the start of the .debug_line section,
684  // which is at the start of that section so this is zero.
685  if (LineSectionSymbol)
686  MCOS->EmitSymbolValue(LineSectionSymbol, 4,
688  else
689  MCOS->EmitIntValue(0, 4);
690 
691  if (RangesSectionSymbol) {
692  // There are multiple sections containing code, so we must use the
693  // .debug_ranges sections.
694 
695  // AT_ranges, the 4 byte offset from the start of the .debug_ranges section
696  // to the address range list for this compilation unit.
697  MCOS->EmitSymbolValue(RangesSectionSymbol, 4);
698  } else {
699  // If we only have one non-empty code section, we can use the simpler
700  // AT_low_pc and AT_high_pc attributes.
701 
702  // Find the first (and only) non-empty text section
703  auto &Sections = context.getGenDwarfSectionSyms();
704  const auto TextSection = Sections.begin();
705  assert(TextSection != Sections.end() && "No text section found");
706 
707  MCSymbol *StartSymbol = (*TextSection)->getBeginSymbol();
708  MCSymbol *EndSymbol = (*TextSection)->getEndSymbol(context);
709  assert(StartSymbol && "StartSymbol must not be NULL");
710  assert(EndSymbol && "EndSymbol must not be NULL");
711 
712  // AT_low_pc, the first address of the default .text section.
713  const MCExpr *Start = MCSymbolRefExpr::create(
714  StartSymbol, MCSymbolRefExpr::VK_None, context);
715  MCOS->EmitValue(Start, AddrSize);
716 
717  // AT_high_pc, the last address of the default .text section.
719  EndSymbol, MCSymbolRefExpr::VK_None, context);
720  MCOS->EmitValue(End, AddrSize);
721  }
722 
723  // AT_name, the name of the source file. Reconstruct from the first directory
724  // and file table entries.
725  const SmallVectorImpl<std::string> &MCDwarfDirs = context.getMCDwarfDirs();
726  if (MCDwarfDirs.size() > 0) {
727  MCOS->EmitBytes(MCDwarfDirs[0]);
729  }
730  const SmallVectorImpl<MCDwarfFile> &MCDwarfFiles =
731  MCOS->getContext().getMCDwarfFiles();
732  MCOS->EmitBytes(MCDwarfFiles[1].Name);
733  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
734 
735  // AT_comp_dir, the working directory the assembly was done in.
736  if (!context.getCompilationDir().empty()) {
737  MCOS->EmitBytes(context.getCompilationDir());
738  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
739  }
740 
741  // AT_APPLE_flags, the command line arguments of the assembler tool.
742  StringRef DwarfDebugFlags = context.getDwarfDebugFlags();
743  if (!DwarfDebugFlags.empty()){
744  MCOS->EmitBytes(DwarfDebugFlags);
745  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
746  }
747 
748  // AT_producer, the version of the assembler tool.
749  StringRef DwarfDebugProducer = context.getDwarfDebugProducer();
750  if (!DwarfDebugProducer.empty())
751  MCOS->EmitBytes(DwarfDebugProducer);
752  else
753  MCOS->EmitBytes(StringRef("llvm-mc (based on LLVM " PACKAGE_VERSION ")"));
754  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
755 
756  // AT_language, a 4 byte value. We use DW_LANG_Mips_Assembler as the dwarf2
757  // draft has no standard code for assembler.
758  MCOS->EmitIntValue(dwarf::DW_LANG_Mips_Assembler, 2);
759 
760  // Third part: the list of label DIEs.
761 
762  // Loop on saved info for dwarf labels and create the DIEs for them.
763  const std::vector<MCGenDwarfLabelEntry> &Entries =
765  for (const auto &Entry : Entries) {
766  // The DW_TAG_label DIE abbrev (2).
767  MCOS->EmitULEB128IntValue(2);
768 
769  // AT_name, of the label without any leading underbar.
770  MCOS->EmitBytes(Entry.getName());
771  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
772 
773  // AT_decl_file, index into the file table.
774  MCOS->EmitIntValue(Entry.getFileNumber(), 4);
775 
776  // AT_decl_line, source line number.
777  MCOS->EmitIntValue(Entry.getLineNumber(), 4);
778 
779  // AT_low_pc, start address of the label.
780  const MCExpr *AT_low_pc = MCSymbolRefExpr::create(Entry.getLabel(),
781  MCSymbolRefExpr::VK_None, context);
782  MCOS->EmitValue(AT_low_pc, AddrSize);
783 
784  // DW_AT_prototyped, a one byte flag value of 0 saying we have no prototype.
785  MCOS->EmitIntValue(0, 1);
786 
787  // The DW_TAG_unspecified_parameters DIE abbrev (3).
788  MCOS->EmitULEB128IntValue(3);
789 
790  // Add the NULL DIE terminating the DW_TAG_unspecified_parameters DIE's.
791  MCOS->EmitIntValue(0, 1);
792  }
793 
794  // Add the NULL DIE terminating the Compile Unit DIE's.
795  MCOS->EmitIntValue(0, 1);
796 
797  // Now set the value of the symbol at the end of the info section.
798  MCOS->EmitLabel(InfoEnd);
799 }
800 
801 // When generating dwarf for assembly source files this emits the data for
802 // .debug_ranges section. We only emit one range list, which spans all of the
803 // executable sections of this file.
804 static void EmitGenDwarfRanges(MCStreamer *MCOS) {
805  MCContext &context = MCOS->getContext();
806  auto &Sections = context.getGenDwarfSectionSyms();
807 
808  const MCAsmInfo *AsmInfo = context.getAsmInfo();
809  int AddrSize = AsmInfo->getPointerSize();
810 
812 
813  for (MCSection *Sec : Sections) {
814  const MCSymbol *StartSymbol = Sec->getBeginSymbol();
815  MCSymbol *EndSymbol = Sec->getEndSymbol(context);
816  assert(StartSymbol && "StartSymbol must not be NULL");
817  assert(EndSymbol && "EndSymbol must not be NULL");
818 
819  // Emit a base address selection entry for the start of this section
820  const MCExpr *SectionStartAddr = MCSymbolRefExpr::create(
821  StartSymbol, MCSymbolRefExpr::VK_None, context);
822  MCOS->emitFill(AddrSize, 0xFF);
823  MCOS->EmitValue(SectionStartAddr, AddrSize);
824 
825  // Emit a range list entry spanning this section
827  *StartSymbol, *EndSymbol, 0);
828  MCOS->EmitIntValue(0, AddrSize);
829  emitAbsValue(*MCOS, SectionSize, AddrSize);
830  }
831 
832  // Emit end of list entry
833  MCOS->EmitIntValue(0, AddrSize);
834  MCOS->EmitIntValue(0, AddrSize);
835 }
836 
837 //
838 // When generating dwarf for assembly source files this emits the Dwarf
839 // sections.
840 //
842  MCContext &context = MCOS->getContext();
843 
844  // Create the dwarf sections in this order (.debug_line already created).
845  const MCAsmInfo *AsmInfo = context.getAsmInfo();
846  bool CreateDwarfSectionSymbols =
848  MCSymbol *LineSectionSymbol = nullptr;
849  if (CreateDwarfSectionSymbols)
850  LineSectionSymbol = MCOS->getDwarfLineTableSymbol(0);
851  MCSymbol *AbbrevSectionSymbol = nullptr;
852  MCSymbol *InfoSectionSymbol = nullptr;
853  MCSymbol *RangesSectionSymbol = nullptr;
854 
855  // Create end symbols for each section, and remove empty sections
856  MCOS->getContext().finalizeDwarfSections(*MCOS);
857 
858  // If there are no sections to generate debug info for, we don't need
859  // to do anything
860  if (MCOS->getContext().getGenDwarfSectionSyms().empty())
861  return;
862 
863  // We only use the .debug_ranges section if we have multiple code sections,
864  // and we are emitting a DWARF version which supports it.
865  const bool UseRangesSection =
866  MCOS->getContext().getGenDwarfSectionSyms().size() > 1 &&
867  MCOS->getContext().getDwarfVersion() >= 3;
868  CreateDwarfSectionSymbols |= UseRangesSection;
869 
871  if (CreateDwarfSectionSymbols) {
872  InfoSectionSymbol = context.createTempSymbol();
873  MCOS->EmitLabel(InfoSectionSymbol);
874  }
876  if (CreateDwarfSectionSymbols) {
877  AbbrevSectionSymbol = context.createTempSymbol();
878  MCOS->EmitLabel(AbbrevSectionSymbol);
879  }
880  if (UseRangesSection) {
882  if (CreateDwarfSectionSymbols) {
883  RangesSectionSymbol = context.createTempSymbol();
884  MCOS->EmitLabel(RangesSectionSymbol);
885  }
886  }
887 
888  assert((RangesSectionSymbol != NULL) || !UseRangesSection);
889 
891 
892  // Output the data for .debug_aranges section.
893  EmitGenDwarfAranges(MCOS, InfoSectionSymbol);
894 
895  if (UseRangesSection)
896  EmitGenDwarfRanges(MCOS);
897 
898  // Output the data for .debug_abbrev section.
899  EmitGenDwarfAbbrev(MCOS);
900 
901  // Output the data for .debug_info section.
902  EmitGenDwarfInfo(MCOS, AbbrevSectionSymbol, LineSectionSymbol,
903  RangesSectionSymbol);
904 }
905 
906 //
907 // When generating dwarf for assembly source files this is called when symbol
908 // for a label is created. If this symbol is not a temporary and is in the
909 // section that dwarf is being generated for, save the needed info to create
910 // a dwarf label.
911 //
913  SourceMgr &SrcMgr, SMLoc &Loc) {
914  // We won't create dwarf labels for temporary symbols.
915  if (Symbol->isTemporary())
916  return;
917  MCContext &context = MCOS->getContext();
918  // We won't create dwarf labels for symbols in sections that we are not
919  // generating debug info for.
920  if (!context.getGenDwarfSectionSyms().count(MCOS->getCurrentSectionOnly()))
921  return;
922 
923  // The dwarf label's name does not have the symbol name's leading
924  // underbar if any.
925  StringRef Name = Symbol->getName();
926  if (Name.startswith("_"))
927  Name = Name.substr(1, Name.size()-1);
928 
929  // Get the dwarf file number to be used for the dwarf label.
930  unsigned FileNumber = context.getGenDwarfFileNumber();
931 
932  // Finding the line number is the expensive part which is why we just don't
933  // pass it in as for some symbols we won't create a dwarf label.
934  unsigned CurBuffer = SrcMgr.FindBufferContainingLoc(Loc);
935  unsigned LineNumber = SrcMgr.FindLineNumber(Loc, CurBuffer);
936 
937  // We create a temporary symbol for use for the AT_high_pc and AT_low_pc
938  // values so that they don't have things like an ARM thumb bit from the
939  // original symbol. So when used they won't get a low bit set after
940  // relocation.
941  MCSymbol *Label = context.createTempSymbol();
942  MCOS->EmitLabel(Label);
943 
944  // Create and entry for the info and add it to the other entries.
946  MCGenDwarfLabelEntry(Name, FileNumber, LineNumber, Label));
947 }
948 
949 static int getDataAlignmentFactor(MCStreamer &streamer) {
950  MCContext &context = streamer.getContext();
951  const MCAsmInfo *asmInfo = context.getAsmInfo();
952  int size = asmInfo->getCalleeSaveStackSlotSize();
953  if (asmInfo->isStackGrowthDirectionUp())
954  return size;
955  else
956  return -size;
957 }
958 
959 static unsigned getSizeForEncoding(MCStreamer &streamer,
960  unsigned symbolEncoding) {
961  MCContext &context = streamer.getContext();
962  unsigned format = symbolEncoding & 0x0f;
963  switch (format) {
964  default: llvm_unreachable("Unknown Encoding");
967  return context.getAsmInfo()->getPointerSize();
970  return 2;
973  return 4;
976  return 8;
977  }
978 }
979 
980 static void emitFDESymbol(MCObjectStreamer &streamer, const MCSymbol &symbol,
981  unsigned symbolEncoding, bool isEH) {
982  MCContext &context = streamer.getContext();
983  const MCAsmInfo *asmInfo = context.getAsmInfo();
984  const MCExpr *v = asmInfo->getExprForFDESymbol(&symbol,
985  symbolEncoding,
986  streamer);
987  unsigned size = getSizeForEncoding(streamer, symbolEncoding);
988  if (asmInfo->doDwarfFDESymbolsUseAbsDiff() && isEH)
989  emitAbsValue(streamer, v, size);
990  else
991  streamer.EmitValue(v, size);
992 }
993 
994 static void EmitPersonality(MCStreamer &streamer, const MCSymbol &symbol,
995  unsigned symbolEncoding) {
996  MCContext &context = streamer.getContext();
997  const MCAsmInfo *asmInfo = context.getAsmInfo();
998  const MCExpr *v = asmInfo->getExprForPersonalitySymbol(&symbol,
999  symbolEncoding,
1000  streamer);
1001  unsigned size = getSizeForEncoding(streamer, symbolEncoding);
1002  streamer.EmitValue(v, size);
1003 }
1004 
1005 namespace {
1006 class FrameEmitterImpl {
1007  int CFAOffset = 0;
1008  int InitialCFAOffset = 0;
1009  bool IsEH;
1010  MCObjectStreamer &Streamer;
1011 
1012 public:
1013  FrameEmitterImpl(bool IsEH, MCObjectStreamer &Streamer)
1014  : IsEH(IsEH), Streamer(Streamer) {}
1015 
1016  /// Emit the unwind information in a compact way.
1017  void EmitCompactUnwind(const MCDwarfFrameInfo &frame);
1018 
1019  const MCSymbol &EmitCIE(const MCSymbol *personality,
1020  unsigned personalityEncoding, const MCSymbol *lsda,
1021  bool IsSignalFrame, unsigned lsdaEncoding,
1022  bool IsSimple);
1023  void EmitFDE(const MCSymbol &cieStart, const MCDwarfFrameInfo &frame,
1024  bool LastInSection, const MCSymbol &SectionStart);
1025  void EmitCFIInstructions(ArrayRef<MCCFIInstruction> Instrs,
1026  MCSymbol *BaseLabel);
1027  void EmitCFIInstruction(const MCCFIInstruction &Instr);
1028 };
1029 
1030 } // end anonymous namespace
1031 
1032 static void emitEncodingByte(MCObjectStreamer &Streamer, unsigned Encoding) {
1033  Streamer.EmitIntValue(Encoding, 1);
1034 }
1035 
1036 void FrameEmitterImpl::EmitCFIInstruction(const MCCFIInstruction &Instr) {
1037  int dataAlignmentFactor = getDataAlignmentFactor(Streamer);
1038  auto *MRI = Streamer.getContext().getRegisterInfo();
1039 
1040  switch (Instr.getOperation()) {
1042  unsigned Reg1 = Instr.getRegister();
1043  unsigned Reg2 = Instr.getRegister2();
1044  if (!IsEH) {
1045  Reg1 = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg1, true), false);
1046  Reg2 = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg2, true), false);
1047  }
1048  Streamer.EmitIntValue(dwarf::DW_CFA_register, 1);
1049  Streamer.EmitULEB128IntValue(Reg1);
1050  Streamer.EmitULEB128IntValue(Reg2);
1051  return;
1052  }
1054  Streamer.EmitIntValue(dwarf::DW_CFA_GNU_window_save, 1);
1055  return;
1056  }
1058  unsigned Reg = Instr.getRegister();
1059  Streamer.EmitIntValue(dwarf::DW_CFA_undefined, 1);
1060  Streamer.EmitULEB128IntValue(Reg);
1061  return;
1062  }
1065  const bool IsRelative =
1067 
1068  Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_offset, 1);
1069 
1070  if (IsRelative)
1071  CFAOffset += Instr.getOffset();
1072  else
1073  CFAOffset = -Instr.getOffset();
1074 
1075  Streamer.EmitULEB128IntValue(CFAOffset);
1076 
1077  return;
1078  }
1080  unsigned Reg = Instr.getRegister();
1081  if (!IsEH)
1082  Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false);
1083  Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa, 1);
1084  Streamer.EmitULEB128IntValue(Reg);
1085  CFAOffset = -Instr.getOffset();
1086  Streamer.EmitULEB128IntValue(CFAOffset);
1087 
1088  return;
1089  }
1090 
1092  unsigned Reg = Instr.getRegister();
1093  if (!IsEH)
1094  Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false);
1095  Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_register, 1);
1096  Streamer.EmitULEB128IntValue(Reg);
1097 
1098  return;
1099  }
1100 
1103  const bool IsRelative =
1105 
1106  unsigned Reg = Instr.getRegister();
1107  if (!IsEH)
1108  Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false);
1109 
1110  int Offset = Instr.getOffset();
1111  if (IsRelative)
1112  Offset -= CFAOffset;
1113  Offset = Offset / dataAlignmentFactor;
1114 
1115  if (Offset < 0) {
1116  Streamer.EmitIntValue(dwarf::DW_CFA_offset_extended_sf, 1);
1117  Streamer.EmitULEB128IntValue(Reg);
1118  Streamer.EmitSLEB128IntValue(Offset);
1119  } else if (Reg < 64) {
1120  Streamer.EmitIntValue(dwarf::DW_CFA_offset + Reg, 1);
1121  Streamer.EmitULEB128IntValue(Offset);
1122  } else {
1123  Streamer.EmitIntValue(dwarf::DW_CFA_offset_extended, 1);
1124  Streamer.EmitULEB128IntValue(Reg);
1125  Streamer.EmitULEB128IntValue(Offset);
1126  }
1127  return;
1128  }
1130  Streamer.EmitIntValue(dwarf::DW_CFA_remember_state, 1);
1131  return;
1133  Streamer.EmitIntValue(dwarf::DW_CFA_restore_state, 1);
1134  return;
1136  unsigned Reg = Instr.getRegister();
1137  Streamer.EmitIntValue(dwarf::DW_CFA_same_value, 1);
1138  Streamer.EmitULEB128IntValue(Reg);
1139  return;
1140  }
1142  unsigned Reg = Instr.getRegister();
1143  if (!IsEH)
1144  Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false);
1145  Streamer.EmitIntValue(dwarf::DW_CFA_restore | Reg, 1);
1146  return;
1147  }
1149  Streamer.EmitIntValue(dwarf::DW_CFA_GNU_args_size, 1);
1150  Streamer.EmitULEB128IntValue(Instr.getOffset());
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(ArrayRef<MCCFIInstruction> Instrs,
1162  MCSymbol *BaseLabel) {
1163  for (const MCCFIInstruction &Instr : Instrs) {
1164  MCSymbol *Label = Instr.getLabel();
1165  // Throw out move if the label is invalid.
1166  if (Label && !Label->isDefined()) continue; // Not emitted, in dead code.
1167 
1168  // Advance row if new location.
1169  if (BaseLabel && Label) {
1170  MCSymbol *ThisSym = Label;
1171  if (ThisSym != BaseLabel) {
1172  Streamer.EmitDwarfAdvanceFrameAddr(BaseLabel, ThisSym);
1173  BaseLabel = ThisSym;
1174  }
1175  }
1176 
1177  EmitCFIInstruction(Instr);
1178  }
1179 }
1180 
1181 /// Emit the unwind information in a compact way.
1182 void FrameEmitterImpl::EmitCompactUnwind(const MCDwarfFrameInfo &Frame) {
1183  MCContext &Context = Streamer.getContext();
1184  const MCObjectFileInfo *MOFI = Context.getObjectFileInfo();
1185 
1186  // range-start range-length compact-unwind-enc personality-func lsda
1187  // _foo LfooEnd-_foo 0x00000023 0 0
1188  // _bar LbarEnd-_bar 0x00000025 __gxx_personality except_tab1
1189  //
1190  // .section __LD,__compact_unwind,regular,debug
1191  //
1192  // # compact unwind for _foo
1193  // .quad _foo
1194  // .set L1,LfooEnd-_foo
1195  // .long L1
1196  // .long 0x01010001
1197  // .quad 0
1198  // .quad 0
1199  //
1200  // # compact unwind for _bar
1201  // .quad _bar
1202  // .set L2,LbarEnd-_bar
1203  // .long L2
1204  // .long 0x01020011
1205  // .quad __gxx_personality
1206  // .quad except_tab1
1207 
1208  uint32_t Encoding = Frame.CompactUnwindEncoding;
1209  if (!Encoding) return;
1210  bool DwarfEHFrameOnly = (Encoding == MOFI->getCompactUnwindDwarfEHFrameOnly());
1211 
1212  // The encoding needs to know we have an LSDA.
1213  if (!DwarfEHFrameOnly && Frame.Lsda)
1214  Encoding |= 0x40000000;
1215 
1216  // Range Start
1217  unsigned FDEEncoding = MOFI->getFDEEncoding();
1218  unsigned Size = getSizeForEncoding(Streamer, FDEEncoding);
1219  Streamer.EmitSymbolValue(Frame.Begin, Size);
1220 
1221  // Range Length
1222  const MCExpr *Range = MakeStartMinusEndExpr(Streamer, *Frame.Begin,
1223  *Frame.End, 0);
1224  emitAbsValue(Streamer, Range, 4);
1225 
1226  // Compact Encoding
1227  Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_udata4);
1228  Streamer.EmitIntValue(Encoding, Size);
1229 
1230  // Personality Function
1231  Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_absptr);
1232  if (!DwarfEHFrameOnly && Frame.Personality)
1233  Streamer.EmitSymbolValue(Frame.Personality, Size);
1234  else
1235  Streamer.EmitIntValue(0, Size); // No personality fn
1236 
1237  // LSDA
1238  Size = getSizeForEncoding(Streamer, Frame.LsdaEncoding);
1239  if (!DwarfEHFrameOnly && Frame.Lsda)
1240  Streamer.EmitSymbolValue(Frame.Lsda, Size);
1241  else
1242  Streamer.EmitIntValue(0, Size); // No LSDA
1243 }
1244 
1245 static unsigned getCIEVersion(bool IsEH, unsigned DwarfVersion) {
1246  if (IsEH)
1247  return 1;
1248  switch (DwarfVersion) {
1249  case 2:
1250  return 1;
1251  case 3:
1252  return 3;
1253  case 4:
1254  case 5:
1255  return 4;
1256  }
1257  llvm_unreachable("Unknown version");
1258 }
1259 
1260 const MCSymbol &FrameEmitterImpl::EmitCIE(const MCSymbol *personality,
1261  unsigned personalityEncoding,
1262  const MCSymbol *lsda,
1263  bool IsSignalFrame,
1264  unsigned lsdaEncoding,
1265  bool IsSimple) {
1266  MCContext &context = Streamer.getContext();
1267  const MCRegisterInfo *MRI = context.getRegisterInfo();
1268  const MCObjectFileInfo *MOFI = context.getObjectFileInfo();
1269 
1270  MCSymbol *sectionStart = context.createTempSymbol();
1271  Streamer.EmitLabel(sectionStart);
1272 
1273  MCSymbol *sectionEnd = context.createTempSymbol();
1274 
1275  // Length
1276  const MCExpr *Length =
1277  MakeStartMinusEndExpr(Streamer, *sectionStart, *sectionEnd, 4);
1278  emitAbsValue(Streamer, Length, 4);
1279 
1280  // CIE ID
1281  unsigned CIE_ID = IsEH ? 0 : -1;
1282  Streamer.EmitIntValue(CIE_ID, 4);
1283 
1284  // Version
1285  uint8_t CIEVersion = getCIEVersion(IsEH, context.getDwarfVersion());
1286  Streamer.EmitIntValue(CIEVersion, 1);
1287 
1288  // Augmentation String
1289  SmallString<8> Augmentation;
1290  if (IsEH) {
1291  Augmentation += "z";
1292  if (personality)
1293  Augmentation += "P";
1294  if (lsda)
1295  Augmentation += "L";
1296  Augmentation += "R";
1297  if (IsSignalFrame)
1298  Augmentation += "S";
1299  Streamer.EmitBytes(Augmentation);
1300  }
1301  Streamer.EmitIntValue(0, 1);
1302 
1303  if (CIEVersion >= 4) {
1304  // Address Size
1305  Streamer.EmitIntValue(context.getAsmInfo()->getPointerSize(), 1);
1306 
1307  // Segment Descriptor Size
1308  Streamer.EmitIntValue(0, 1);
1309  }
1310 
1311  // Code Alignment Factor
1312  Streamer.EmitULEB128IntValue(context.getAsmInfo()->getMinInstAlignment());
1313 
1314  // Data Alignment Factor
1315  Streamer.EmitSLEB128IntValue(getDataAlignmentFactor(Streamer));
1316 
1317  // Return Address Register
1318  if (CIEVersion == 1) {
1319  assert(MRI->getRARegister() <= 255 &&
1320  "DWARF 2 encodes return_address_register in one byte");
1321  Streamer.EmitIntValue(MRI->getDwarfRegNum(MRI->getRARegister(), IsEH), 1);
1322  } else {
1323  Streamer.EmitULEB128IntValue(
1324  MRI->getDwarfRegNum(MRI->getRARegister(), IsEH));
1325  }
1326 
1327  // Augmentation Data Length (optional)
1328 
1329  unsigned augmentationLength = 0;
1330  if (IsEH) {
1331  if (personality) {
1332  // Personality Encoding
1333  augmentationLength += 1;
1334  // Personality
1335  augmentationLength += getSizeForEncoding(Streamer, personalityEncoding);
1336  }
1337  if (lsda)
1338  augmentationLength += 1;
1339  // Encoding of the FDE pointers
1340  augmentationLength += 1;
1341 
1342  Streamer.EmitULEB128IntValue(augmentationLength);
1343 
1344  // Augmentation Data (optional)
1345  if (personality) {
1346  // Personality Encoding
1347  emitEncodingByte(Streamer, personalityEncoding);
1348  // Personality
1349  EmitPersonality(Streamer, *personality, personalityEncoding);
1350  }
1351 
1352  if (lsda)
1353  emitEncodingByte(Streamer, lsdaEncoding);
1354 
1355  // Encoding of the FDE pointers
1356  emitEncodingByte(Streamer, MOFI->getFDEEncoding());
1357  }
1358 
1359  // Initial Instructions
1360 
1361  const MCAsmInfo *MAI = context.getAsmInfo();
1362  if (!IsSimple) {
1363  const std::vector<MCCFIInstruction> &Instructions =
1364  MAI->getInitialFrameState();
1365  EmitCFIInstructions(Instructions, nullptr);
1366  }
1367 
1368  InitialCFAOffset = CFAOffset;
1369 
1370  // Padding
1371  Streamer.EmitValueToAlignment(IsEH ? 4 : MAI->getPointerSize());
1372 
1373  Streamer.EmitLabel(sectionEnd);
1374  return *sectionStart;
1375 }
1376 
1377 void FrameEmitterImpl::EmitFDE(const MCSymbol &cieStart,
1378  const MCDwarfFrameInfo &frame,
1379  bool LastInSection,
1380  const MCSymbol &SectionStart) {
1381  MCContext &context = Streamer.getContext();
1382  MCSymbol *fdeStart = context.createTempSymbol();
1383  MCSymbol *fdeEnd = context.createTempSymbol();
1384  const MCObjectFileInfo *MOFI = context.getObjectFileInfo();
1385 
1386  CFAOffset = InitialCFAOffset;
1387 
1388  // Length
1389  const MCExpr *Length = MakeStartMinusEndExpr(Streamer, *fdeStart, *fdeEnd, 0);
1390  emitAbsValue(Streamer, Length, 4);
1391 
1392  Streamer.EmitLabel(fdeStart);
1393 
1394  // CIE Pointer
1395  const MCAsmInfo *asmInfo = context.getAsmInfo();
1396  if (IsEH) {
1397  const MCExpr *offset =
1398  MakeStartMinusEndExpr(Streamer, cieStart, *fdeStart, 0);
1399  emitAbsValue(Streamer, offset, 4);
1400  } else if (!asmInfo->doesDwarfUseRelocationsAcrossSections()) {
1401  const MCExpr *offset =
1402  MakeStartMinusEndExpr(Streamer, SectionStart, cieStart, 0);
1403  emitAbsValue(Streamer, offset, 4);
1404  } else {
1405  Streamer.EmitSymbolValue(&cieStart, 4);
1406  }
1407 
1408  // PC Begin
1409  unsigned PCEncoding =
1411  unsigned PCSize = getSizeForEncoding(Streamer, PCEncoding);
1412  emitFDESymbol(Streamer, *frame.Begin, PCEncoding, IsEH);
1413 
1414  // PC Range
1415  const MCExpr *Range =
1416  MakeStartMinusEndExpr(Streamer, *frame.Begin, *frame.End, 0);
1417  emitAbsValue(Streamer, Range, PCSize);
1418 
1419  if (IsEH) {
1420  // Augmentation Data Length
1421  unsigned augmentationLength = 0;
1422 
1423  if (frame.Lsda)
1424  augmentationLength += getSizeForEncoding(Streamer, frame.LsdaEncoding);
1425 
1426  Streamer.EmitULEB128IntValue(augmentationLength);
1427 
1428  // Augmentation Data
1429  if (frame.Lsda)
1430  emitFDESymbol(Streamer, *frame.Lsda, frame.LsdaEncoding, true);
1431  }
1432 
1433  // Call Frame Instructions
1434  EmitCFIInstructions(frame.Instructions, frame.Begin);
1435 
1436  // Padding
1437  // The size of a .eh_frame section has to be a multiple of the alignment
1438  // since a null CIE is interpreted as the end. Old systems overaligned
1439  // .eh_frame, so we do too and account for it in the last FDE.
1440  unsigned Align = LastInSection ? asmInfo->getPointerSize() : PCSize;
1441  Streamer.EmitValueToAlignment(Align);
1442 
1443  Streamer.EmitLabel(fdeEnd);
1444 }
1445 
1446 namespace {
1447 struct CIEKey {
1448  static const CIEKey getEmptyKey() {
1449  return CIEKey(nullptr, 0, -1, false, false);
1450  }
1451  static const CIEKey getTombstoneKey() {
1452  return CIEKey(nullptr, -1, 0, false, false);
1453  }
1454 
1455  CIEKey(const MCSymbol *Personality, unsigned PersonalityEncoding,
1456  unsigned LsdaEncoding, bool IsSignalFrame, bool IsSimple)
1457  : Personality(Personality), PersonalityEncoding(PersonalityEncoding),
1458  LsdaEncoding(LsdaEncoding), IsSignalFrame(IsSignalFrame),
1459  IsSimple(IsSimple) {}
1460  const MCSymbol *Personality;
1461  unsigned PersonalityEncoding;
1462  unsigned LsdaEncoding;
1463  bool IsSignalFrame;
1464  bool IsSimple;
1465 };
1466 } // anonymous namespace
1467 
1468 namespace llvm {
1469 template <> struct DenseMapInfo<CIEKey> {
1470  static CIEKey getEmptyKey() { return CIEKey::getEmptyKey(); }
1471  static CIEKey getTombstoneKey() { return CIEKey::getTombstoneKey(); }
1472  static unsigned getHashValue(const CIEKey &Key) {
1473  return static_cast<unsigned>(
1474  hash_combine(Key.Personality, Key.PersonalityEncoding, Key.LsdaEncoding,
1475  Key.IsSignalFrame, Key.IsSimple));
1476  }
1477  static bool isEqual(const CIEKey &LHS, const CIEKey &RHS) {
1478  return LHS.Personality == RHS.Personality &&
1479  LHS.PersonalityEncoding == RHS.PersonalityEncoding &&
1480  LHS.LsdaEncoding == RHS.LsdaEncoding &&
1481  LHS.IsSignalFrame == RHS.IsSignalFrame &&
1482  LHS.IsSimple == RHS.IsSimple;
1483  }
1484 };
1485 } // namespace llvm
1486 
1488  bool IsEH) {
1489  Streamer.generateCompactUnwindEncodings(MAB);
1490 
1491  MCContext &Context = Streamer.getContext();
1492  const MCObjectFileInfo *MOFI = Context.getObjectFileInfo();
1493  FrameEmitterImpl Emitter(IsEH, Streamer);
1494  ArrayRef<MCDwarfFrameInfo> FrameArray = Streamer.getDwarfFrameInfos();
1495 
1496  // Emit the compact unwind info if available.
1497  bool NeedsEHFrameSection = !MOFI->getSupportsCompactUnwindWithoutEHFrame();
1498  if (IsEH && MOFI->getCompactUnwindSection()) {
1499  bool SectionEmitted = false;
1500  for (const MCDwarfFrameInfo &Frame : FrameArray) {
1501  if (Frame.CompactUnwindEncoding == 0) continue;
1502  if (!SectionEmitted) {
1503  Streamer.SwitchSection(MOFI->getCompactUnwindSection());
1504  Streamer.EmitValueToAlignment(Context.getAsmInfo()->getPointerSize());
1505  SectionEmitted = true;
1506  }
1507  NeedsEHFrameSection |=
1508  Frame.CompactUnwindEncoding ==
1510  Emitter.EmitCompactUnwind(Frame);
1511  }
1512  }
1513 
1514  if (!NeedsEHFrameSection) return;
1515 
1516  MCSection &Section =
1517  IsEH ? *const_cast<MCObjectFileInfo *>(MOFI)->getEHFrameSection()
1518  : *MOFI->getDwarfFrameSection();
1519 
1520  Streamer.SwitchSection(&Section);
1521  MCSymbol *SectionStart = Context.createTempSymbol();
1522  Streamer.EmitLabel(SectionStart);
1523 
1525 
1526  const MCSymbol *DummyDebugKey = nullptr;
1527  bool CanOmitDwarf = MOFI->getOmitDwarfIfHaveCompactUnwind();
1528  for (auto I = FrameArray.begin(), E = FrameArray.end(); I != E;) {
1529  const MCDwarfFrameInfo &Frame = *I;
1530  ++I;
1531  if (CanOmitDwarf && Frame.CompactUnwindEncoding !=
1533  // Don't generate an EH frame if we don't need one. I.e., it's taken care
1534  // of by the compact unwind encoding.
1535  continue;
1536 
1537  CIEKey Key(Frame.Personality, Frame.PersonalityEncoding,
1538  Frame.LsdaEncoding, Frame.IsSignalFrame, Frame.IsSimple);
1539  const MCSymbol *&CIEStart = IsEH ? CIEStarts[Key] : DummyDebugKey;
1540  if (!CIEStart)
1541  CIEStart = &Emitter.EmitCIE(Frame.Personality, Frame.PersonalityEncoding,
1542  Frame.Lsda, Frame.IsSignalFrame,
1543  Frame.LsdaEncoding, Frame.IsSimple);
1544 
1545  Emitter.EmitFDE(*CIEStart, Frame, I == E, *SectionStart);
1546  }
1547 }
1548 
1550  uint64_t AddrDelta) {
1551  MCContext &Context = Streamer.getContext();
1552  SmallString<256> Tmp;
1553  raw_svector_ostream OS(Tmp);
1554  MCDwarfFrameEmitter::EncodeAdvanceLoc(Context, AddrDelta, OS);
1555  Streamer.EmitBytes(OS.str());
1556 }
1557 
1559  uint64_t AddrDelta,
1560  raw_ostream &OS) {
1561  // Scale the address delta by the minimum instruction length.
1562  AddrDelta = ScaleAddrDelta(Context, AddrDelta);
1563 
1564  if (AddrDelta == 0) {
1565  } else if (isUIntN(6, AddrDelta)) {
1566  uint8_t Opcode = dwarf::DW_CFA_advance_loc | AddrDelta;
1567  OS << Opcode;
1568  } else if (isUInt<8>(AddrDelta)) {
1569  OS << uint8_t(dwarf::DW_CFA_advance_loc1);
1570  OS << uint8_t(AddrDelta);
1571  } else if (isUInt<16>(AddrDelta)) {
1572  OS << uint8_t(dwarf::DW_CFA_advance_loc2);
1573  if (Context.getAsmInfo()->isLittleEndian())
1574  support::endian::Writer<support::little>(OS).write<uint16_t>(AddrDelta);
1575  else
1576  support::endian::Writer<support::big>(OS).write<uint16_t>(AddrDelta);
1577  } else {
1578  assert(isUInt<32>(AddrDelta));
1579  OS << uint8_t(dwarf::DW_CFA_advance_loc4);
1580  if (Context.getAsmInfo()->isLittleEndian())
1582  else
1583  support::endian::Writer<support::big>(OS).write<uint32_t>(AddrDelta);
1584  }
1585 }
static const MCExpr * forceExpAbs(MCStreamer &OS, const MCExpr *Expr)
Definition: MCDwarf.cpp:230
void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry &E)
Definition: MCContext.h:521
constexpr bool isUInt< 32 >(uint64_t x)
Definition: MathExtras.h:315
Instances of this class represent a uniqued identifier for a section in the current translation unit...
Definition: MCSection.h:40
void push_back(const T &Elt)
Definition: SmallVector.h:211
int getDwarfRegNum(unsigned RegNum, bool isEH) const
Map a target register to an equivalent dwarf register number.
const MCAsmInfo * getAsmInfo() const
Definition: MCContext.h:243
unsigned getFDEEncoding() const
static int getDataAlignmentFactor(MCStreamer &streamer)
Definition: MCDwarf.cpp:949
void EmitBytes(StringRef Data) override
Emit the bytes in Data into the output.
LLVMContext & Context
static CIEKey getTombstoneKey()
Definition: MCDwarf.cpp:1471
#define DWARF2_FLAG_PROLOGUE_END
Definition: MCDwarf.h:68
static void Make(MCObjectStreamer *MCOS, MCSection *Section)
Definition: MCDwarf.cpp:50
static const MCSymbolRefExpr * create(const MCSymbol *Symbol, MCContext &Ctx)
Definition: MCExpr.h:298
size_t i
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:120
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
const SmallVectorImpl< MCDwarfFile > & getMCDwarfFiles(unsigned CUID=0)
Definition: MCContext.h:463
iterator end() const
Definition: ArrayRef.h:130
SourceMgr SrcMgr
virtual void EmitBytes(StringRef Data)
Emit the bytes in Data into the output.
Definition: MCStreamer.cpp:807
static void EmitAdvanceLoc(MCObjectStreamer &Streamer, uint64_t AddrDelta)
Definition: MCDwarf.cpp:1549
bool getOmitDwarfIfHaveCompactUnwind() const
A raw_ostream that writes to an SmallVector or SmallString.
Definition: raw_ostream.h:490
ArrayRef< MCDwarfFrameInfo > getDwarfFrameInfos() const
Definition: MCStreamer.h:228
#define op(i)
static void Emit(MCStreamer *MCOS, MCDwarfLineTableParams Params, int64_t LineDelta, uint64_t AddrDelta)
Utility function to emit the encoding to a streamer.
Definition: MCDwarf.cpp:407
virtual MCSymbol * getDwarfLineTableSymbol(unsigned CUID)
Definition: MCStreamer.cpp:192
static void EmitGenDwarfInfo(MCStreamer *MCOS, const MCSymbol *AbbrevSectionSymbol, const MCSymbol *LineSectionSymbol, const MCSymbol *RangesSectionSymbol)
Definition: MCDwarf.cpp:640
uint16_t getDwarfVersion() const
Definition: MCContext.h:535
unsigned LsdaEncoding
Definition: MCDwarf.h:503
StringRef getDwarfDebugFlags()
Definition: MCContext.h:526
static void Encode(MCContext &Context, MCDwarfLineTableParams Params, int64_t LineDelta, uint64_t AddrDelta, raw_ostream &OS)
Utility function to encode a Dwarf pair of LineDelta and AddrDeltas.
Definition: MCDwarf.cpp:423
void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel, const MCSymbol *Label, unsigned PointerSize)
unsigned getRegister() const
Definition: MCDwarf.h:464
std::vector< MCCFIInstruction > Instructions
Definition: MCDwarf.h:500
static const MCBinaryExpr * create(Opcode Op, const MCExpr *LHS, const MCExpr *RHS, MCContext &Ctx)
Definition: MCExpr.cpp:139
virtual const MCExpr * getExprForPersonalitySymbol(const MCSymbol *Sym, unsigned Encoding, MCStreamer &Streamer) const
Definition: MCAsmInfo.cpp:122
int getOffset() const
Definition: MCDwarf.h:477
#define DWARF2_FLAG_IS_STMT
Definition: MCDwarf.h:66
StringRef getDwarfDebugProducer()
Definition: MCContext.h:529
bool getSupportsCompactUnwindWithoutEHFrame() const
std::string Name
Definition: MCDwarf.h:46
struct fuzzer::@269 Flags
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
ArrayRef< T > makeArrayRef(const T &OneElt)
Construct an ArrayRef from a single element.
Definition: ArrayRef.h:440
MCSection * getCurrentSectionOnly() const
Definition: MCStreamer.h:302
void finalizeDwarfSections(MCStreamer &MCOS)
Remove empty sections from SectionStartEndSyms, to avoid generating useless debug info for them...
Definition: MCContext.cpp:495
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:34
MCSymbol * Begin
Definition: MCDwarf.h:496
uint8_t DWARF2LineRange
Range of line offsets in a special line info. opcode.
Definition: MCDwarf.h:193
Reg
All possible values of the reg field in the ModR/M byte.
const std::vector< MCCFIInstruction > & getInitialFrameState() const
Definition: MCAsmInfo.h:569
const MCSymbol * Lsda
Definition: MCDwarf.h:499
static void emitFDESymbol(MCObjectStreamer &streamer, const MCSymbol &symbol, unsigned symbolEncoding, bool isEH)
Definition: MCDwarf.cpp:980
MCDwarfLineTable & getMCDwarfLineTable(unsigned CUID)
Definition: MCContext.h:453
MCContext & getContext() const
Definition: MCStreamer.h:221
bool isLittleEndian() const
True if the target is little endian.
Definition: MCAsmInfo.h:392
const SmallVectorImpl< std::string > & getMCDwarfDirs(unsigned CUID=0)
Definition: MCContext.h:466
virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value)
Emit an assignment of Value to Symbol.
Definition: MCStreamer.cpp:722
Context object for machine code objects.
Definition: MCContext.h:51
StringRef getValues() const
Definition: MCDwarf.h:484
static void EmitGenDwarfAbbrev(MCStreamer *MCOS)
Definition: MCDwarf.cpp:513
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool startswith(StringRef Prefix) const
Check if this string starts with the given Prefix.
Definition: StringRef.h:264
unsigned getDwarfCompileUnitID()
Definition: MCContext.h:476
Streaming object file generation interface.
Instances of this class represent the information from a dwarf .loc directive.
Definition: MCDwarf.h:54
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
unsigned getGenDwarfFileNumber()
Definition: MCContext.h:506
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE size_t size() const
size - Get the string size.
Definition: StringRef.h:135
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:85
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:141
void EmitValue(const MCExpr *Value, unsigned Size, SMLoc Loc=SMLoc())
Definition: MCStreamer.cpp:116
void EmitCU(MCObjectStreamer *MCOS, MCDwarfLineTableParams Params) const
Definition: MCDwarf.cpp:319
static GCRegistry::Add< CoreCLRGC > E("coreclr","CoreCLR-compatible GC")
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:124
This class is intended to be used as a base class for asm properties and features specific to the tar...
Definition: MCAsmInfo.h:57
MCSection * getDwarfLineSection() const
bool needsDwarfSectionOffsetDirective() const
Definition: MCAsmInfo.h:454
static uint64_t SpecialAddr(MCDwarfLineTableParams Params, uint64_t op)
Given a special op, return the address skip amount (in units of DWARF2_LINE_MIN_INSN_LENGTH).
Definition: MCDwarf.cpp:418
static unsigned getSizeForEncoding(MCStreamer &streamer, unsigned symbolEncoding)
Definition: MCDwarf.cpp:959
StringRef filename(StringRef path)
Get filename.
Definition: Path.cpp:584
Streaming machine code generation interface.
Definition: MCStreamer.h:161
static unsigned getCIEVersion(bool IsEH, unsigned DwarfVersion)
Definition: MCDwarf.cpp:1245
MCSection * getCompactUnwindSection() const
static void EmitAbbrev(MCStreamer *MCOS, uint64_t Name, uint64_t Form)
Definition: MCDwarf.cpp:506
MCSymbol * createTempSymbol(bool CanBeUnnamed=true)
Create and return a new assembler temporary symbol with a unique but unspecified name.
Definition: MCContext.cpp:218
uint8_t DWARF2LineOpcodeBase
First special line opcode - leave room for the standard opcodes.
Definition: MCDwarf.h:188
* if(!EatIfPresent(lltok::kw_thread_local)) return false
ParseOptionalThreadLocal := /*empty.
constexpr bool isUInt< 8 >(uint64_t x)
Definition: MathExtras.h:309
unsigned const MachineRegisterInfo * MRI
void write(ArrayRef< value_type > Vals)
Definition: EndianStream.h:30
#define DWARF2_FLAG_EPILOGUE_BEGIN
Definition: MCDwarf.h:69
virtual void SwitchSection(MCSection *Section, const MCExpr *Subsection=nullptr)
Set the current section where code is being emitted to Section.
Definition: MCStreamer.cpp:829
static void emitAbsValue(MCStreamer &OS, const MCExpr *Value, unsigned Size)
Definition: MCDwarf.cpp:241
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE StringRef substr(size_t Start, size_t N=npos) const
Return a reference to the substring from [Start, Start + N).
Definition: StringRef.h:587
static void EmitDwarfLineTable(MCObjectStreamer *MCOS, MCSection *Section, const MCLineSection::MCDwarfLineEntryCollection &LineEntries)
Definition: MCDwarf.cpp:101
static void EmitGenDwarfAranges(MCStreamer *MCOS, const MCSymbol *InfoSectionSymbol)
Definition: MCDwarf.cpp:568
std::vector< MCDwarfLineEntry > MCDwarfLineEntryCollection
Definition: MCDwarf.h:167
uint32_t Offset
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:337
static const unsigned End
iterator begin() const
Definition: ArrayRef.h:129
#define DWARF2_FLAG_BASIC_BLOCK
Definition: MCDwarf.h:67
const MCDwarfLoc & getCurrentDwarfLoc()
Definition: MCContext.h:502
unsigned PersonalityEncoding
Definition: MCDwarf.h:502
This owns the files read by a parser, handles include stacks, and handles diagnostic wrangling...
Definition: SourceMgr.h:35
int8_t DWARF2LineBase
Minimum line offset in a special line info.
Definition: MCDwarf.h:191
void generateCompactUnwindEncodings(MCAsmBackend *MAB)
Definition: MCStreamer.cpp:77
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
void clearDwarfLocSeen()
Definition: MCContext.h:499
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:383
const SetVector< MCSection * > & getGenDwarfSectionSyms()
Definition: MCContext.h:510
OpType getOperation() const
Definition: MCDwarf.h:461
unsigned getMinInstAlignment() const
Definition: MCAsmInfo.h:463
bool doDwarfFDESymbolsUseAbsDiff() const
Definition: MCAsmInfo.h:561
static unsigned getHashValue(const CIEKey &Key)
Definition: MCDwarf.cpp:1472
virtual void EmitLabel(MCSymbol *Symbol)
Emit a label for Symbol into the current section.
Definition: MCStreamer.cpp:293
constexpr size_t array_lengthof(T(&)[N])
Find the length of an array.
Definition: STLExtras.h:649
static bool isEqual(const CIEKey &LHS, const CIEKey &RHS)
Definition: MCDwarf.cpp:1477
unsigned getRegister2() const
Definition: MCDwarf.h:472
StringRef str()
Return a StringRef for the vector contents.
Definition: raw_ostream.h:515
static void EncodeAdvanceLoc(MCContext &Context, uint64_t AddrDelta, raw_ostream &OS)
Definition: MCDwarf.cpp:1558
uint32_t CompactUnwindEncoding
Definition: MCDwarf.h:504
static void EmitGenDwarfRanges(MCStreamer *MCOS)
Definition: MCDwarf.cpp:804
bool isDefined(bool SetUsed=true) const
isDefined - Check if this symbol is defined (i.e., it has an address).
Definition: MCSymbol.h:245
bool getDwarfLocSeen()
Definition: MCContext.h:501
bool insert(MapEntryTy *KeyValue)
insert - Insert the specified key/value pair into the map.
Definition: StringMap.h:348
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:518
StringRef parent_path(StringRef path)
Get parent path.
Definition: Path.cpp:493
static CIEKey getEmptyKey()
Definition: MCDwarf.cpp:1470
unsigned FindLineNumber(SMLoc Loc, unsigned BufferID=0) const
Find the line number for the specified location in the specified file.
Definition: SourceMgr.h:143
hash_code hash_combine(const Ts &...args)
Combine values into a single hash_code.
Definition: Hashing.h:602
StringRef get_separator()
Return the preferred separator for this platform.
Definition: Path.cpp:626
bool isTemporary() const
isTemporary - Check if this is an assembler temporary symbol.
Definition: MCSymbol.h:216
static void Emit(MCStreamer *MCOS)
Definition: MCDwarf.cpp:841
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:130
#define DWARF2_LINE_DEFAULT_IS_STMT
Definition: MCDwarf.h:64
static StringRef toStringRef(bool B)
Construct a string ref from a boolean.
Definition: StringExtras.h:33
static uint64_t ScaleAddrDelta(MCContext &Context, uint64_t AddrDelta)
Definition: MCDwarf.cpp:34
const MCRegisterInfo * getRegisterInfo() const
Definition: MCContext.h:245
Instances of this class represent the line information for the dwarf line table entries.
Definition: MCDwarf.h:136
static void Emit(MCObjectStreamer *MCOS, MCDwarfLineTableParams Params)
Definition: MCDwarf.cpp:183
StringRef getCompilationDir() const
Get the compilation directory for DW_AT_comp_dir The compilation directory should be set with setComp...
Definition: MCContext.h:430
MCSection * getDwarfARangesSection() const
void Emit(MCStreamer &MCOS, MCDwarfLineTableParams Params) const
Definition: MCDwarf.cpp:202
static const MCExpr * MakeStartMinusEndExpr(const MCStreamer &MCOS, const MCSymbol &Start, const MCSymbol &End, int IntVal)
Definition: MCDwarf.cpp:78
StringRef getName() const
getName - Get the symbol name.
Definition: MCSymbol.h:199
StringMap< unsigned > SourceIdMap
Definition: MCDwarf.h:200
static void EmitPersonality(MCStreamer &streamer, const MCSymbol &symbol, unsigned symbolEncoding)
Definition: MCDwarf.cpp:994
static void Make(MCSymbol *Symbol, MCStreamer *MCOS, SourceMgr &SrcMgr, SMLoc &Loc)
Definition: MCDwarf.cpp:912
const std::map< unsigned, MCDwarfLineTable > & getMCDwarfLineTables() const
Definition: MCContext.h:449
const MCSymbol * Personality
Definition: MCDwarf.h:498
bool isStackGrowthDirectionUp() const
True if target stack grow up.
Definition: MCAsmInfo.h:395
MCSection * getDwarfFrameSection() const
#define I(x, y, z)
Definition: MD5.cpp:54
LLVM_ATTRIBUTE_ALWAYS_INLINE size_type size() const
Definition: SmallVector.h:135
unsigned getCalleeSaveStackSlotSize() const
Get the callee-saved register stack slot size in bytes.
Definition: MCAsmInfo.h:387
constexpr bool isUInt< 16 >(uint64_t x)
Definition: MathExtras.h:312
virtual void emitFill(uint64_t NumBytes, uint8_t FillValue)
Emit NumBytes bytes worth of the value specified by FillValue.
Definition: MCStreamer.cpp:157
const MCLineDivisionMap & getMCLineEntries() const
Definition: MCDwarf.h:178
bool hasAggressiveSymbolFolding() const
Definition: MCAsmInfo.h:506
std::pair< MCSymbol *, MCSymbol * > Emit(MCStreamer *MCOS, MCDwarfLineTableParams Params) const
Definition: MCDwarf.cpp:208
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:100
MCSymbol * endSection(MCSection *Section)
Definition: MCStreamer.cpp:843
unsigned DirIndex
Definition: MCDwarf.h:49
unsigned FindBufferContainingLoc(SMLoc Loc) const
Return the ID of the buffer containing the specified location.
Definition: SourceMgr.cpp:67
MCGenDwarfLabelEntry(StringRef name, unsigned fileNumber, unsigned lineNumber, MCSymbol *label)
Definition: MCDwarf.h:309
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
virtual const MCExpr * getExprForFDESymbol(const MCSymbol *Sym, unsigned Encoding, MCStreamer &Streamer) const
Definition: MCAsmInfo.cpp:129
LLVM Value Representation.
Definition: Value.h:71
Generic interface to target specific assembler backends.
Definition: MCAsmBackend.h:36
const MCObjectFileInfo * getObjectFileInfo() const
Definition: MCContext.h:247
MCSection * getDwarfInfoSection() const
MCSection * getDwarfRangesSection() const
unsigned getCompactUnwindDwarfEHFrameOnly() const
static void emitEncodingByte(MCObjectStreamer &Streamer, unsigned Encoding)
Definition: MCDwarf.cpp:1032
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
SmallVector< MCDwarfFile, 3 > MCDwarfFiles
Definition: MCDwarf.h:199
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:412
static void Emit(MCObjectStreamer &streamer, MCAsmBackend *MAB, bool isEH)
Definition: MCDwarf.cpp:1487
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:47
Instances of this class represent the name of the dwarf .file directive and its associated dwarf file...
Definition: MCDwarf.h:43
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:24
unsigned getFile(StringRef &Directory, StringRef &FileName, unsigned FileNumber=0)
Definition: MCDwarf.cpp:332
bool isUIntN(unsigned N, uint64_t x)
isUIntN - Checks if an unsigned integer fits into the given (dynamic) bit width.
Definition: MathExtras.h:360
MCSymbol * getLabel() const
Definition: MCDwarf.h:462
SmallVector< std::string, 3 > MCDwarfDirs
Definition: MCDwarf.h:198
static const MCConstantExpr * create(int64_t Value, MCContext &Ctx)
Definition: MCExpr.cpp:149
bool doesDwarfUseRelocationsAcrossSections() const
Definition: MCAsmInfo.h:558