LLVM  7.0.0svn
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/ArrayRef.h"
12 #include "llvm/ADT/DenseMap.h"
13 #include "llvm/ADT/Hashing.h"
14 #include "llvm/ADT/None.h"
15 #include "llvm/ADT/STLExtras.h"
16 #include "llvm/ADT/SmallString.h"
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/Twine.h"
21 #include "llvm/Config/config.h"
22 #include "llvm/MC/MCAsmInfo.h"
23 #include "llvm/MC/MCContext.h"
24 #include "llvm/MC/MCExpr.h"
27 #include "llvm/MC/MCRegisterInfo.h"
28 #include "llvm/MC/MCSection.h"
29 #include "llvm/MC/MCStreamer.h"
30 #include "llvm/MC/MCSymbol.h"
32 #include "llvm/Support/Casting.h"
33 #include "llvm/Support/Endian.h"
36 #include "llvm/Support/LEB128.h"
38 #include "llvm/Support/Path.h"
39 #include "llvm/Support/SourceMgr.h"
41 #include <cassert>
42 #include <cstdint>
43 #include <string>
44 #include <utility>
45 #include <vector>
46 
47 using namespace llvm;
48 
49 /// Manage the .debug_line_str section contents, if we use it.
51  MCSymbol *LineStrLabel = nullptr;
53  bool UseRelocs = false;
54 
55 public:
56  /// Construct an instance that can emit .debug_line_str (for use in a normal
57  /// v5 line table).
58  explicit MCDwarfLineStr(MCContext &Ctx) {
60  if (UseRelocs)
61  LineStrLabel =
63  }
64 
65  /// Emit a reference to the string.
66  void emitRef(MCStreamer *MCOS, StringRef Path);
67 
68  /// Emit the .debug_line_str section if appropriate.
69  void emitSection(MCStreamer *MCOS);
70 };
71 
72 static inline uint64_t ScaleAddrDelta(MCContext &Context, uint64_t AddrDelta) {
73  unsigned MinInsnLength = Context.getAsmInfo()->getMinInstAlignment();
74  if (MinInsnLength == 1)
75  return AddrDelta;
76  if (AddrDelta % MinInsnLength != 0) {
77  // TODO: report this error, but really only once.
78  ;
79  }
80  return AddrDelta / MinInsnLength;
81 }
82 
83 //
84 // This is called when an instruction is assembled into the specified section
85 // and if there is information from the last .loc directive that has yet to have
86 // a line entry made for it is made.
87 //
89  if (!MCOS->getContext().getDwarfLocSeen())
90  return;
91 
92  // Create a symbol at in the current section for use in the line entry.
93  MCSymbol *LineSym = MCOS->getContext().createTempSymbol();
94  // Set the value of the symbol to use for the MCDwarfLineEntry.
95  MCOS->EmitLabel(LineSym);
96 
97  // Get the current .loc info saved in the context.
98  const MCDwarfLoc &DwarfLoc = MCOS->getContext().getCurrentDwarfLoc();
99 
100  // Create a (local) line entry with the symbol and the current .loc info.
101  MCDwarfLineEntry LineEntry(LineSym, DwarfLoc);
102 
103  // clear DwarfLocSeen saying the current .loc info is now used.
104  MCOS->getContext().clearDwarfLocSeen();
105 
106  // Add the line entry to this section's entries.
107  MCOS->getContext()
109  .getMCLineSections()
110  .addLineEntry(LineEntry, Section);
111 }
112 
113 //
114 // This helper routine returns an expression of End - Start + IntVal .
115 //
116 static inline const MCExpr *MakeStartMinusEndExpr(const MCStreamer &MCOS,
117  const MCSymbol &Start,
118  const MCSymbol &End,
119  int IntVal) {
121  const MCExpr *Res =
122  MCSymbolRefExpr::create(&End, Variant, MCOS.getContext());
123  const MCExpr *RHS =
124  MCSymbolRefExpr::create(&Start, Variant, MCOS.getContext());
125  const MCExpr *Res1 =
127  const MCExpr *Res2 =
128  MCConstantExpr::create(IntVal, MCOS.getContext());
129  const MCExpr *Res3 =
131  return Res3;
132 }
133 
134 //
135 // This helper routine returns an expression of Start + IntVal .
136 //
137 static inline const MCExpr *
138 makeStartPlusIntExpr(MCContext &Ctx, const MCSymbol &Start, int IntVal) {
140  const MCExpr *LHS = MCSymbolRefExpr::create(&Start, Variant, Ctx);
141  const MCExpr *RHS = MCConstantExpr::create(IntVal, Ctx);
142  const MCExpr *Res = MCBinaryExpr::create(MCBinaryExpr::Add, LHS, RHS, Ctx);
143  return Res;
144 }
145 
146 //
147 // This emits the Dwarf line table for the specified section from the entries
148 // in the LineSection.
149 //
150 static inline void
152  const MCLineSection::MCDwarfLineEntryCollection &LineEntries) {
153  unsigned FileNum = 1;
154  unsigned LastLine = 1;
155  unsigned Column = 0;
156  unsigned Flags = DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0;
157  unsigned Isa = 0;
158  unsigned Discriminator = 0;
159  MCSymbol *LastLabel = nullptr;
160 
161  // Loop through each MCDwarfLineEntry and encode the dwarf line number table.
162  for (const MCDwarfLineEntry &LineEntry : LineEntries) {
163  int64_t LineDelta = static_cast<int64_t>(LineEntry.getLine()) - LastLine;
164 
165  if (FileNum != LineEntry.getFileNum()) {
166  FileNum = LineEntry.getFileNum();
167  MCOS->EmitIntValue(dwarf::DW_LNS_set_file, 1);
168  MCOS->EmitULEB128IntValue(FileNum);
169  }
170  if (Column != LineEntry.getColumn()) {
171  Column = LineEntry.getColumn();
172  MCOS->EmitIntValue(dwarf::DW_LNS_set_column, 1);
173  MCOS->EmitULEB128IntValue(Column);
174  }
175  if (Discriminator != LineEntry.getDiscriminator() &&
176  MCOS->getContext().getDwarfVersion() >= 4) {
177  Discriminator = LineEntry.getDiscriminator();
178  unsigned Size = getULEB128Size(Discriminator);
179  MCOS->EmitIntValue(dwarf::DW_LNS_extended_op, 1);
180  MCOS->EmitULEB128IntValue(Size + 1);
181  MCOS->EmitIntValue(dwarf::DW_LNE_set_discriminator, 1);
182  MCOS->EmitULEB128IntValue(Discriminator);
183  }
184  if (Isa != LineEntry.getIsa()) {
185  Isa = LineEntry.getIsa();
186  MCOS->EmitIntValue(dwarf::DW_LNS_set_isa, 1);
187  MCOS->EmitULEB128IntValue(Isa);
188  }
189  if ((LineEntry.getFlags() ^ Flags) & DWARF2_FLAG_IS_STMT) {
190  Flags = LineEntry.getFlags();
191  MCOS->EmitIntValue(dwarf::DW_LNS_negate_stmt, 1);
192  }
193  if (LineEntry.getFlags() & DWARF2_FLAG_BASIC_BLOCK)
194  MCOS->EmitIntValue(dwarf::DW_LNS_set_basic_block, 1);
195  if (LineEntry.getFlags() & DWARF2_FLAG_PROLOGUE_END)
196  MCOS->EmitIntValue(dwarf::DW_LNS_set_prologue_end, 1);
197  if (LineEntry.getFlags() & DWARF2_FLAG_EPILOGUE_BEGIN)
198  MCOS->EmitIntValue(dwarf::DW_LNS_set_epilogue_begin, 1);
199 
200  MCSymbol *Label = LineEntry.getLabel();
201 
202  // At this point we want to emit/create the sequence to encode the delta in
203  // line numbers and the increment of the address from the previous Label
204  // and the current Label.
205  const MCAsmInfo *asmInfo = MCOS->getContext().getAsmInfo();
206  MCOS->EmitDwarfAdvanceLineAddr(LineDelta, LastLabel, Label,
207  asmInfo->getCodePointerSize());
208 
209  Discriminator = 0;
210  LastLine = LineEntry.getLine();
211  LastLabel = Label;
212  }
213 
214  // Emit a DW_LNE_end_sequence for the end of the section.
215  // Use the section end label to compute the address delta and use INT64_MAX
216  // as the line delta which is the signal that this is actually a
217  // DW_LNE_end_sequence.
218  MCSymbol *SectionEnd = MCOS->endSection(Section);
219 
220  // Switch back the dwarf line section, in case endSection had to switch the
221  // section.
222  MCContext &Ctx = MCOS->getContext();
224 
225  const MCAsmInfo *AsmInfo = Ctx.getAsmInfo();
226  MCOS->EmitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, SectionEnd,
227  AsmInfo->getCodePointerSize());
228 }
229 
230 //
231 // This emits the Dwarf file and the line tables.
232 //
234  MCDwarfLineTableParams Params) {
235  MCContext &context = MCOS->getContext();
236 
237  auto &LineTables = context.getMCDwarfLineTables();
238 
239  // Bail out early so we don't switch to the debug_line section needlessly and
240  // in doing so create an unnecessary (if empty) section.
241  if (LineTables.empty())
242  return;
243 
244  // In a v5 non-split line table, put the strings in a separate section.
245  Optional<MCDwarfLineStr> LineStr;
246  if (context.getDwarfVersion() >= 5)
247  LineStr = MCDwarfLineStr(context);
248 
249  // Switch to the section where the table will be emitted into.
251 
252  // Handle the rest of the Compile Units.
253  for (const auto &CUIDTablePair : LineTables)
254  CUIDTablePair.second.EmitCU(MCOS, Params, LineStr);
255 
256  if (LineStr)
257  LineStr->emitSection(MCOS);
258 }
259 
261  MCDwarfLineTableParams Params) const {
262  Optional<MCDwarfLineStr> NoLineStr(None);
263  MCOS.EmitLabel(Header.Emit(&MCOS, Params, None, NoLineStr).second);
264 }
265 
266 std::pair<MCSymbol *, MCSymbol *>
268  Optional<MCDwarfLineStr> &LineStr) const {
269  static const char StandardOpcodeLengths[] = {
270  0, // length of DW_LNS_copy
271  1, // length of DW_LNS_advance_pc
272  1, // length of DW_LNS_advance_line
273  1, // length of DW_LNS_set_file
274  1, // length of DW_LNS_set_column
275  0, // length of DW_LNS_negate_stmt
276  0, // length of DW_LNS_set_basic_block
277  0, // length of DW_LNS_const_add_pc
278  1, // length of DW_LNS_fixed_advance_pc
279  0, // length of DW_LNS_set_prologue_end
280  0, // length of DW_LNS_set_epilogue_begin
281  1 // DW_LNS_set_isa
282  };
283  assert(array_lengthof(StandardOpcodeLengths) >=
284  (Params.DWARF2LineOpcodeBase - 1U));
285  return Emit(
286  MCOS, Params,
287  makeArrayRef(StandardOpcodeLengths, Params.DWARF2LineOpcodeBase - 1),
288  LineStr);
289 }
290 
291 static const MCExpr *forceExpAbs(MCStreamer &OS, const MCExpr* Expr) {
292  MCContext &Context = OS.getContext();
293  assert(!isa<MCSymbolRefExpr>(Expr));
294  if (Context.getAsmInfo()->hasAggressiveSymbolFolding())
295  return Expr;
296 
297  MCSymbol *ABS = Context.createTempSymbol();
298  OS.EmitAssignment(ABS, Expr);
299  return MCSymbolRefExpr::create(ABS, Context);
300 }
301 
302 static void emitAbsValue(MCStreamer &OS, const MCExpr *Value, unsigned Size) {
303  const MCExpr *ABS = forceExpAbs(OS, Value);
304  OS.EmitValue(ABS, Size);
305 }
306 
308  // Switch to the .debug_line_str section.
309  MCOS->SwitchSection(
311  // Emit the strings without perturbing the offsets we used.
312  LineStrings.finalizeInOrder();
314  Data.resize(LineStrings.getSize());
315  LineStrings.write((uint8_t *)Data.data());
316  MCOS->EmitBinaryData(Data.str());
317 }
318 
320  int RefSize = 4; // FIXME: Support DWARF-64
321  size_t Offset = LineStrings.add(Path);
322  if (UseRelocs) {
323  MCContext &Ctx = MCOS->getContext();
324  MCOS->EmitValue(makeStartPlusIntExpr(Ctx, *LineStrLabel, Offset), RefSize);
325  } else
326  MCOS->EmitIntValue(Offset, RefSize);
327 }
328 
329 void MCDwarfLineTableHeader::emitV2FileDirTables(MCStreamer *MCOS) const {
330  // First the directory table.
331  for (auto &Dir : MCDwarfDirs) {
332  MCOS->EmitBytes(Dir); // The DirectoryName, and...
333  MCOS->EmitBytes(StringRef("\0", 1)); // its null terminator.
334  }
335  MCOS->EmitIntValue(0, 1); // Terminate the directory list.
336 
337  // Second the file table.
338  for (unsigned i = 1; i < MCDwarfFiles.size(); i++) {
339  assert(!MCDwarfFiles[i].Name.empty());
340  MCOS->EmitBytes(MCDwarfFiles[i].Name); // FileName and...
341  MCOS->EmitBytes(StringRef("\0", 1)); // its null terminator.
342  MCOS->EmitULEB128IntValue(MCDwarfFiles[i].DirIndex); // Directory number.
343  MCOS->EmitIntValue(0, 1); // Last modification timestamp (always 0).
344  MCOS->EmitIntValue(0, 1); // File size (always 0).
345  }
346  MCOS->EmitIntValue(0, 1); // Terminate the file list.
347 }
348 
349 void MCDwarfLineTableHeader::emitV5FileDirTables(
350  MCStreamer *MCOS, Optional<MCDwarfLineStr> &LineStr) const {
351  // The directory format, which is just a list of the directory paths. In a
352  // non-split object, these are references to .debug_line_str; in a split
353  // object, they are inline strings.
354  MCOS->EmitIntValue(1, 1);
355  MCOS->EmitULEB128IntValue(dwarf::DW_LNCT_path);
356  MCOS->EmitULEB128IntValue(LineStr ? dwarf::DW_FORM_line_strp
357  : dwarf::DW_FORM_string);
358  MCOS->EmitULEB128IntValue(MCDwarfDirs.size() + 1);
359  if (LineStr) {
360  // Record path strings, emit references here.
361  LineStr->emitRef(MCOS, CompilationDir);
362  for (auto &Dir : MCDwarfDirs)
363  LineStr->emitRef(MCOS, Dir);
364  } else {
365  // The list of directory paths. CompilationDir comes first.
366  MCOS->EmitBytes(CompilationDir);
367  MCOS->EmitBytes(StringRef("\0", 1));
368  for (auto &Dir : MCDwarfDirs) {
369  MCOS->EmitBytes(Dir); // The DirectoryName, and...
370  MCOS->EmitBytes(StringRef("\0", 1)); // its null terminator.
371  }
372  }
373 
374  // The file format, which is the inline null-terminated filename and a
375  // directory index. We don't track file size/timestamp so don't emit them
376  // in the v5 table. Emit MD5 checksums if we have them.
377  MCOS->EmitIntValue(HasMD5 ? 3 : 2, 1);
378  MCOS->EmitULEB128IntValue(dwarf::DW_LNCT_path);
379  MCOS->EmitULEB128IntValue(LineStr ? dwarf::DW_FORM_line_strp
380  : dwarf::DW_FORM_string);
381  MCOS->EmitULEB128IntValue(dwarf::DW_LNCT_directory_index);
382  MCOS->EmitULEB128IntValue(dwarf::DW_FORM_udata);
383  if (HasMD5) {
384  MCOS->EmitULEB128IntValue(dwarf::DW_LNCT_MD5);
385  MCOS->EmitULEB128IntValue(dwarf::DW_FORM_data16);
386  }
387  // Then the list of file names. These start at 1.
388  MCOS->EmitULEB128IntValue(MCDwarfFiles.size() - 1);
389  for (unsigned i = 1; i < MCDwarfFiles.size(); ++i) {
390  assert(!MCDwarfFiles[i].Name.empty());
391  if (LineStr)
392  LineStr->emitRef(MCOS, MCDwarfFiles[i].Name);
393  else {
394  MCOS->EmitBytes(MCDwarfFiles[i].Name); // FileName and...
395  MCOS->EmitBytes(StringRef("\0", 1)); // its null terminator.
396  }
397  MCOS->EmitULEB128IntValue(MCDwarfFiles[i].DirIndex); // Directory number.
398  if (HasMD5) {
399  MD5::MD5Result *Cksum = MCDwarfFiles[i].Checksum;
400  MCOS->EmitBinaryData(
401  StringRef(reinterpret_cast<const char *>(Cksum->Bytes.data()),
402  Cksum->Bytes.size()));
403  }
404  }
405 }
406 
407 std::pair<MCSymbol *, MCSymbol *>
409  ArrayRef<char> StandardOpcodeLengths,
410  Optional<MCDwarfLineStr> &LineStr) const {
411  MCContext &context = MCOS->getContext();
412 
413  // Create a symbol at the beginning of the line table.
414  MCSymbol *LineStartSym = Label;
415  if (!LineStartSym)
416  LineStartSym = context.createTempSymbol();
417  // Set the value of the symbol, as we are at the start of the line table.
418  MCOS->EmitLabel(LineStartSym);
419 
420  // Create a symbol for the end of the section (to be set when we get there).
421  MCSymbol *LineEndSym = context.createTempSymbol();
422 
423  // The first 4 bytes is the total length of the information for this
424  // compilation unit (not including these 4 bytes for the length).
425  emitAbsValue(*MCOS,
426  MakeStartMinusEndExpr(*MCOS, *LineStartSym, *LineEndSym, 4), 4);
427 
428  // Next 2 bytes is the Version.
429  // FIXME: On Darwin we still default to V2.
430  unsigned LineTableVersion = context.getDwarfVersion();
431  if (context.getObjectFileInfo()->getTargetTriple().isOSDarwin())
432  LineTableVersion = 2;
433  MCOS->EmitIntValue(LineTableVersion, 2);
434 
435  // Keep track of the bytes between the very start and where the header length
436  // comes out.
437  unsigned PreHeaderLengthBytes = 4 + 2;
438 
439  // In v5, we get address info next.
440  if (LineTableVersion >= 5) {
441  MCOS->EmitIntValue(context.getAsmInfo()->getCodePointerSize(), 1);
442  MCOS->EmitIntValue(0, 1); // Segment selector; same as EmitGenDwarfAranges.
443  PreHeaderLengthBytes += 2;
444  }
445 
446  // Create a symbol for the end of the prologue (to be set when we get there).
447  MCSymbol *ProEndSym = context.createTempSymbol(); // Lprologue_end
448 
449  // Length of the prologue, is the next 4 bytes. This is actually the length
450  // from after the length word, to the end of the prologue.
451  emitAbsValue(*MCOS,
452  MakeStartMinusEndExpr(*MCOS, *LineStartSym, *ProEndSym,
453  (PreHeaderLengthBytes + 4)),
454  4);
455 
456  // Parameters of the state machine, are next.
457  MCOS->EmitIntValue(context.getAsmInfo()->getMinInstAlignment(), 1);
458  // maximum_operations_per_instruction
459  // For non-VLIW architectures this field is always 1.
460  // FIXME: VLIW architectures need to update this field accordingly.
461  if (LineTableVersion >= 4)
462  MCOS->EmitIntValue(1, 1);
464  MCOS->EmitIntValue(Params.DWARF2LineBase, 1);
465  MCOS->EmitIntValue(Params.DWARF2LineRange, 1);
466  MCOS->EmitIntValue(StandardOpcodeLengths.size() + 1, 1);
467 
468  // Standard opcode lengths
469  for (char Length : StandardOpcodeLengths)
470  MCOS->EmitIntValue(Length, 1);
471 
472  // Put out the directory and file tables. The formats vary depending on
473  // the version.
474  if (LineTableVersion >= 5)
475  emitV5FileDirTables(MCOS, LineStr);
476  else
477  emitV2FileDirTables(MCOS);
478 
479  // This is the end of the prologue, so set the value of the symbol at the
480  // end of the prologue (that was used in a previous expression).
481  MCOS->EmitLabel(ProEndSym);
482 
483  return std::make_pair(LineStartSym, LineEndSym);
484 }
485 
487  MCDwarfLineTableParams Params,
488  Optional<MCDwarfLineStr> &LineStr) const {
489  MCSymbol *LineEndSym = Header.Emit(MCOS, Params, LineStr).second;
490 
491  // Put out the line tables.
492  for (const auto &LineSec : MCLineSections.getMCLineEntries())
493  EmitDwarfLineTable(MCOS, LineSec.first, LineSec.second);
494 
495  // This is the end of the section, so set the value of the symbol at the end
496  // of this section (that was used in a previous expression).
497  MCOS->EmitLabel(LineEndSym);
498 }
499 
500 unsigned MCDwarfLineTable::getFile(StringRef &Directory, StringRef &FileName,
501  MD5::MD5Result *Checksum,
502  unsigned FileNumber) {
503  return Header.getFile(Directory, FileName, Checksum, FileNumber);
504 }
505 
507  StringRef &FileName,
508  MD5::MD5Result *Checksum,
509  unsigned FileNumber) {
510  if (Directory == CompilationDir)
511  Directory = "";
512  if (FileName.empty()) {
513  FileName = "<stdin>";
514  Directory = "";
515  }
516  assert(!FileName.empty());
517  if (FileNumber == 0) {
518  // File numbers start with 1 and/or after any file numbers
519  // allocated by inline-assembler .file directives.
520  FileNumber = MCDwarfFiles.empty() ? 1 : MCDwarfFiles.size();
521  SmallString<256> Buffer;
522  auto IterBool = SourceIdMap.insert(
523  std::make_pair((Directory + Twine('\0') + FileName).toStringRef(Buffer),
524  FileNumber));
525  if (!IterBool.second)
526  return IterBool.first->second;
527  }
528  // Make space for this FileNumber in the MCDwarfFiles vector if needed.
529  if (FileNumber >= MCDwarfFiles.size())
530  MCDwarfFiles.resize(FileNumber + 1);
531 
532  // Get the new MCDwarfFile slot for this FileNumber.
533  MCDwarfFile &File = MCDwarfFiles[FileNumber];
534 
535  // It is an error to use see the same number more than once.
536  if (!File.Name.empty())
537  return 0;
538 
539  // If any files have an MD5 checksum, they all must.
540  if (FileNumber > 1)
541  assert(HasMD5 == (Checksum != nullptr));
542 
543  if (Directory.empty()) {
544  // Separate the directory part from the basename of the FileName.
545  StringRef tFileName = sys::path::filename(FileName);
546  if (!tFileName.empty()) {
547  Directory = sys::path::parent_path(FileName);
548  if (!Directory.empty())
549  FileName = tFileName;
550  }
551  }
552 
553  // Find or make an entry in the MCDwarfDirs vector for this Directory.
554  // Capture directory name.
555  unsigned DirIndex;
556  if (Directory.empty()) {
557  // For FileNames with no directories a DirIndex of 0 is used.
558  DirIndex = 0;
559  } else {
560  DirIndex = 0;
561  for (unsigned End = MCDwarfDirs.size(); DirIndex < End; DirIndex++) {
562  if (Directory == MCDwarfDirs[DirIndex])
563  break;
564  }
565  if (DirIndex >= MCDwarfDirs.size())
566  MCDwarfDirs.push_back(Directory);
567  // The DirIndex is one based, as DirIndex of 0 is used for FileNames with
568  // no directories. MCDwarfDirs[] is unlike MCDwarfFiles[] in that the
569  // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames
570  // are stored at MCDwarfFiles[FileNumber].Name .
571  DirIndex++;
572  }
573 
574  File.Name = FileName;
575  File.DirIndex = DirIndex;
576  File.Checksum = Checksum;
577  if (Checksum)
578  HasMD5 = true;
579 
580  // return the allocated FileNumber.
581  return FileNumber;
582 }
583 
584 /// Utility function to emit the encoding to a streamer.
586  int64_t LineDelta, uint64_t AddrDelta) {
587  MCContext &Context = MCOS->getContext();
588  SmallString<256> Tmp;
589  raw_svector_ostream OS(Tmp);
590  MCDwarfLineAddr::Encode(Context, Params, LineDelta, AddrDelta, OS);
591  MCOS->EmitBytes(OS.str());
592 }
593 
594 /// Given a special op, return the address skip amount (in units of
595 /// DWARF2_LINE_MIN_INSN_LENGTH).
596 static uint64_t SpecialAddr(MCDwarfLineTableParams Params, uint64_t op) {
597  return (op - Params.DWARF2LineOpcodeBase) / Params.DWARF2LineRange;
598 }
599 
600 /// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas.
602  int64_t LineDelta, uint64_t AddrDelta,
603  raw_ostream &OS) {
604  uint64_t Temp, Opcode;
605  bool NeedCopy = false;
606 
607  // The maximum address skip amount that can be encoded with a special op.
608  uint64_t MaxSpecialAddrDelta = SpecialAddr(Params, 255);
609 
610  // Scale the address delta by the minimum instruction length.
611  AddrDelta = ScaleAddrDelta(Context, AddrDelta);
612 
613  // A LineDelta of INT64_MAX is a signal that this is actually a
614  // DW_LNE_end_sequence. We cannot use special opcodes here, since we want the
615  // end_sequence to emit the matrix entry.
616  if (LineDelta == INT64_MAX) {
617  if (AddrDelta == MaxSpecialAddrDelta)
618  OS << char(dwarf::DW_LNS_const_add_pc);
619  else if (AddrDelta) {
620  OS << char(dwarf::DW_LNS_advance_pc);
621  encodeULEB128(AddrDelta, OS);
622  }
623  OS << char(dwarf::DW_LNS_extended_op);
624  OS << char(1);
625  OS << char(dwarf::DW_LNE_end_sequence);
626  return;
627  }
628 
629  // Bias the line delta by the base.
630  Temp = LineDelta - Params.DWARF2LineBase;
631 
632  // If the line increment is out of range of a special opcode, we must encode
633  // it with DW_LNS_advance_line.
634  if (Temp >= Params.DWARF2LineRange ||
635  Temp + Params.DWARF2LineOpcodeBase > 255) {
636  OS << char(dwarf::DW_LNS_advance_line);
637  encodeSLEB128(LineDelta, OS);
638 
639  LineDelta = 0;
640  Temp = 0 - Params.DWARF2LineBase;
641  NeedCopy = true;
642  }
643 
644  // Use DW_LNS_copy instead of a "line +0, addr +0" special opcode.
645  if (LineDelta == 0 && AddrDelta == 0) {
646  OS << char(dwarf::DW_LNS_copy);
647  return;
648  }
649 
650  // Bias the opcode by the special opcode base.
651  Temp += Params.DWARF2LineOpcodeBase;
652 
653  // Avoid overflow when addr_delta is large.
654  if (AddrDelta < 256 + MaxSpecialAddrDelta) {
655  // Try using a special opcode.
656  Opcode = Temp + AddrDelta * Params.DWARF2LineRange;
657  if (Opcode <= 255) {
658  OS << char(Opcode);
659  return;
660  }
661 
662  // Try using DW_LNS_const_add_pc followed by special op.
663  Opcode = Temp + (AddrDelta - MaxSpecialAddrDelta) * Params.DWARF2LineRange;
664  if (Opcode <= 255) {
665  OS << char(dwarf::DW_LNS_const_add_pc);
666  OS << char(Opcode);
667  return;
668  }
669  }
670 
671  // Otherwise use DW_LNS_advance_pc.
672  OS << char(dwarf::DW_LNS_advance_pc);
673  encodeULEB128(AddrDelta, OS);
674 
675  if (NeedCopy)
676  OS << char(dwarf::DW_LNS_copy);
677  else {
678  assert(Temp <= 255 && "Buggy special opcode encoding.");
679  OS << char(Temp);
680  }
681 }
682 
683 // Utility function to write a tuple for .debug_abbrev.
684 static void EmitAbbrev(MCStreamer *MCOS, uint64_t Name, uint64_t Form) {
685  MCOS->EmitULEB128IntValue(Name);
686  MCOS->EmitULEB128IntValue(Form);
687 }
688 
689 // When generating dwarf for assembly source files this emits
690 // the data for .debug_abbrev section which contains three DIEs.
691 static void EmitGenDwarfAbbrev(MCStreamer *MCOS) {
692  MCContext &context = MCOS->getContext();
694 
695  // DW_TAG_compile_unit DIE abbrev (1).
696  MCOS->EmitULEB128IntValue(1);
697  MCOS->EmitULEB128IntValue(dwarf::DW_TAG_compile_unit);
699  EmitAbbrev(MCOS, dwarf::DW_AT_stmt_list, context.getDwarfVersion() >= 4
700  ? dwarf::DW_FORM_sec_offset
701  : dwarf::DW_FORM_data4);
702  if (context.getGenDwarfSectionSyms().size() > 1 &&
703  context.getDwarfVersion() >= 3) {
704  EmitAbbrev(MCOS, dwarf::DW_AT_ranges, context.getDwarfVersion() >= 4
705  ? dwarf::DW_FORM_sec_offset
706  : dwarf::DW_FORM_data4);
707  } else {
708  EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr);
709  EmitAbbrev(MCOS, dwarf::DW_AT_high_pc, dwarf::DW_FORM_addr);
710  }
711  EmitAbbrev(MCOS, dwarf::DW_AT_name, dwarf::DW_FORM_string);
712  if (!context.getCompilationDir().empty())
713  EmitAbbrev(MCOS, dwarf::DW_AT_comp_dir, dwarf::DW_FORM_string);
714  StringRef DwarfDebugFlags = context.getDwarfDebugFlags();
715  if (!DwarfDebugFlags.empty())
716  EmitAbbrev(MCOS, dwarf::DW_AT_APPLE_flags, dwarf::DW_FORM_string);
717  EmitAbbrev(MCOS, dwarf::DW_AT_producer, dwarf::DW_FORM_string);
718  EmitAbbrev(MCOS, dwarf::DW_AT_language, dwarf::DW_FORM_data2);
719  EmitAbbrev(MCOS, 0, 0);
720 
721  // DW_TAG_label DIE abbrev (2).
722  MCOS->EmitULEB128IntValue(2);
723  MCOS->EmitULEB128IntValue(dwarf::DW_TAG_label);
725  EmitAbbrev(MCOS, dwarf::DW_AT_name, dwarf::DW_FORM_string);
726  EmitAbbrev(MCOS, dwarf::DW_AT_decl_file, dwarf::DW_FORM_data4);
727  EmitAbbrev(MCOS, dwarf::DW_AT_decl_line, dwarf::DW_FORM_data4);
728  EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr);
729  EmitAbbrev(MCOS, dwarf::DW_AT_prototyped, dwarf::DW_FORM_flag);
730  EmitAbbrev(MCOS, 0, 0);
731 
732  // DW_TAG_unspecified_parameters DIE abbrev (3).
733  MCOS->EmitULEB128IntValue(3);
734  MCOS->EmitULEB128IntValue(dwarf::DW_TAG_unspecified_parameters);
736  EmitAbbrev(MCOS, 0, 0);
737 
738  // Terminate the abbreviations for this compilation unit.
739  MCOS->EmitIntValue(0, 1);
740 }
741 
742 // When generating dwarf for assembly source files this emits the data for
743 // .debug_aranges section. This section contains a header and a table of pairs
744 // of PointerSize'ed values for the address and size of section(s) with line
745 // table entries.
746 static void EmitGenDwarfAranges(MCStreamer *MCOS,
747  const MCSymbol *InfoSectionSymbol) {
748  MCContext &context = MCOS->getContext();
749 
750  auto &Sections = context.getGenDwarfSectionSyms();
751 
753 
754  // This will be the length of the .debug_aranges section, first account for
755  // the size of each item in the header (see below where we emit these items).
756  int Length = 4 + 2 + 4 + 1 + 1;
757 
758  // Figure the padding after the header before the table of address and size
759  // pairs who's values are PointerSize'ed.
760  const MCAsmInfo *asmInfo = context.getAsmInfo();
761  int AddrSize = asmInfo->getCodePointerSize();
762  int Pad = 2 * AddrSize - (Length & (2 * AddrSize - 1));
763  if (Pad == 2 * AddrSize)
764  Pad = 0;
765  Length += Pad;
766 
767  // Add the size of the pair of PointerSize'ed values for the address and size
768  // of each section we have in the table.
769  Length += 2 * AddrSize * Sections.size();
770  // And the pair of terminating zeros.
771  Length += 2 * AddrSize;
772 
773  // Emit the header for this section.
774  // The 4 byte length not including the 4 byte value for the length.
775  MCOS->EmitIntValue(Length - 4, 4);
776  // The 2 byte version, which is 2.
777  MCOS->EmitIntValue(2, 2);
778  // The 4 byte offset to the compile unit in the .debug_info from the start
779  // of the .debug_info.
780  if (InfoSectionSymbol)
781  MCOS->EmitSymbolValue(InfoSectionSymbol, 4,
783  else
784  MCOS->EmitIntValue(0, 4);
785  // The 1 byte size of an address.
786  MCOS->EmitIntValue(AddrSize, 1);
787  // The 1 byte size of a segment descriptor, we use a value of zero.
788  MCOS->EmitIntValue(0, 1);
789  // Align the header with the padding if needed, before we put out the table.
790  for(int i = 0; i < Pad; i++)
791  MCOS->EmitIntValue(0, 1);
792 
793  // Now emit the table of pairs of PointerSize'ed values for the section
794  // addresses and sizes.
795  for (MCSection *Sec : Sections) {
796  const MCSymbol *StartSymbol = Sec->getBeginSymbol();
797  MCSymbol *EndSymbol = Sec->getEndSymbol(context);
798  assert(StartSymbol && "StartSymbol must not be NULL");
799  assert(EndSymbol && "EndSymbol must not be NULL");
800 
801  const MCExpr *Addr = MCSymbolRefExpr::create(
802  StartSymbol, MCSymbolRefExpr::VK_None, context);
803  const MCExpr *Size = MakeStartMinusEndExpr(*MCOS,
804  *StartSymbol, *EndSymbol, 0);
805  MCOS->EmitValue(Addr, AddrSize);
806  emitAbsValue(*MCOS, Size, AddrSize);
807  }
808 
809  // And finally the pair of terminating zeros.
810  MCOS->EmitIntValue(0, AddrSize);
811  MCOS->EmitIntValue(0, AddrSize);
812 }
813 
814 // When generating dwarf for assembly source files this emits the data for
815 // .debug_info section which contains three parts. The header, the compile_unit
816 // DIE and a list of label DIEs.
817 static void EmitGenDwarfInfo(MCStreamer *MCOS,
818  const MCSymbol *AbbrevSectionSymbol,
819  const MCSymbol *LineSectionSymbol,
820  const MCSymbol *RangesSectionSymbol) {
821  MCContext &context = MCOS->getContext();
822 
824 
825  // Create a symbol at the start and end of this section used in here for the
826  // expression to calculate the length in the header.
827  MCSymbol *InfoStart = context.createTempSymbol();
828  MCOS->EmitLabel(InfoStart);
829  MCSymbol *InfoEnd = context.createTempSymbol();
830 
831  // First part: the header.
832 
833  // The 4 byte total length of the information for this compilation unit, not
834  // including these 4 bytes.
835  const MCExpr *Length = MakeStartMinusEndExpr(*MCOS, *InfoStart, *InfoEnd, 4);
836  emitAbsValue(*MCOS, Length, 4);
837 
838  // The 2 byte DWARF version.
839  MCOS->EmitIntValue(context.getDwarfVersion(), 2);
840 
841  // The DWARF v5 header has unit type, address size, abbrev offset.
842  // Earlier versions have abbrev offset, address size.
843  const MCAsmInfo &AsmInfo = *context.getAsmInfo();
844  int AddrSize = AsmInfo.getCodePointerSize();
845  if (context.getDwarfVersion() >= 5) {
846  MCOS->EmitIntValue(dwarf::DW_UT_compile, 1);
847  MCOS->EmitIntValue(AddrSize, 1);
848  }
849  // The 4 byte offset to the debug abbrevs from the start of the .debug_abbrev,
850  // it is at the start of that section so this is zero.
851  if (AbbrevSectionSymbol == nullptr)
852  MCOS->EmitIntValue(0, 4);
853  else
854  MCOS->EmitSymbolValue(AbbrevSectionSymbol, 4,
856  if (context.getDwarfVersion() <= 4)
857  MCOS->EmitIntValue(AddrSize, 1);
858 
859  // Second part: the compile_unit DIE.
860 
861  // The DW_TAG_compile_unit DIE abbrev (1).
862  MCOS->EmitULEB128IntValue(1);
863 
864  // DW_AT_stmt_list, a 4 byte offset from the start of the .debug_line section,
865  // which is at the start of that section so this is zero.
866  if (LineSectionSymbol)
867  MCOS->EmitSymbolValue(LineSectionSymbol, 4,
869  else
870  MCOS->EmitIntValue(0, 4);
871 
872  if (RangesSectionSymbol) {
873  // There are multiple sections containing code, so we must use the
874  // .debug_ranges sections.
875 
876  // AT_ranges, the 4 byte offset from the start of the .debug_ranges section
877  // to the address range list for this compilation unit.
878  MCOS->EmitSymbolValue(RangesSectionSymbol, 4);
879  } else {
880  // If we only have one non-empty code section, we can use the simpler
881  // AT_low_pc and AT_high_pc attributes.
882 
883  // Find the first (and only) non-empty text section
884  auto &Sections = context.getGenDwarfSectionSyms();
885  const auto TextSection = Sections.begin();
886  assert(TextSection != Sections.end() && "No text section found");
887 
888  MCSymbol *StartSymbol = (*TextSection)->getBeginSymbol();
889  MCSymbol *EndSymbol = (*TextSection)->getEndSymbol(context);
890  assert(StartSymbol && "StartSymbol must not be NULL");
891  assert(EndSymbol && "EndSymbol must not be NULL");
892 
893  // AT_low_pc, the first address of the default .text section.
894  const MCExpr *Start = MCSymbolRefExpr::create(
895  StartSymbol, MCSymbolRefExpr::VK_None, context);
896  MCOS->EmitValue(Start, AddrSize);
897 
898  // AT_high_pc, the last address of the default .text section.
900  EndSymbol, MCSymbolRefExpr::VK_None, context);
901  MCOS->EmitValue(End, AddrSize);
902  }
903 
904  // AT_name, the name of the source file. Reconstruct from the first directory
905  // and file table entries.
906  const SmallVectorImpl<std::string> &MCDwarfDirs = context.getMCDwarfDirs();
907  if (MCDwarfDirs.size() > 0) {
908  MCOS->EmitBytes(MCDwarfDirs[0]);
910  }
911  const SmallVectorImpl<MCDwarfFile> &MCDwarfFiles =
912  MCOS->getContext().getMCDwarfFiles();
913  MCOS->EmitBytes(MCDwarfFiles[1].Name);
914  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
915 
916  // AT_comp_dir, the working directory the assembly was done in.
917  if (!context.getCompilationDir().empty()) {
918  MCOS->EmitBytes(context.getCompilationDir());
919  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
920  }
921 
922  // AT_APPLE_flags, the command line arguments of the assembler tool.
923  StringRef DwarfDebugFlags = context.getDwarfDebugFlags();
924  if (!DwarfDebugFlags.empty()){
925  MCOS->EmitBytes(DwarfDebugFlags);
926  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
927  }
928 
929  // AT_producer, the version of the assembler tool.
930  StringRef DwarfDebugProducer = context.getDwarfDebugProducer();
931  if (!DwarfDebugProducer.empty())
932  MCOS->EmitBytes(DwarfDebugProducer);
933  else
934  MCOS->EmitBytes(StringRef("llvm-mc (based on LLVM " PACKAGE_VERSION ")"));
935  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
936 
937  // AT_language, a 4 byte value. We use DW_LANG_Mips_Assembler as the dwarf2
938  // draft has no standard code for assembler.
939  MCOS->EmitIntValue(dwarf::DW_LANG_Mips_Assembler, 2);
940 
941  // Third part: the list of label DIEs.
942 
943  // Loop on saved info for dwarf labels and create the DIEs for them.
944  const std::vector<MCGenDwarfLabelEntry> &Entries =
946  for (const auto &Entry : Entries) {
947  // The DW_TAG_label DIE abbrev (2).
948  MCOS->EmitULEB128IntValue(2);
949 
950  // AT_name, of the label without any leading underbar.
951  MCOS->EmitBytes(Entry.getName());
952  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
953 
954  // AT_decl_file, index into the file table.
955  MCOS->EmitIntValue(Entry.getFileNumber(), 4);
956 
957  // AT_decl_line, source line number.
958  MCOS->EmitIntValue(Entry.getLineNumber(), 4);
959 
960  // AT_low_pc, start address of the label.
961  const MCExpr *AT_low_pc = MCSymbolRefExpr::create(Entry.getLabel(),
962  MCSymbolRefExpr::VK_None, context);
963  MCOS->EmitValue(AT_low_pc, AddrSize);
964 
965  // DW_AT_prototyped, a one byte flag value of 0 saying we have no prototype.
966  MCOS->EmitIntValue(0, 1);
967 
968  // The DW_TAG_unspecified_parameters DIE abbrev (3).
969  MCOS->EmitULEB128IntValue(3);
970 
971  // Add the NULL DIE terminating the DW_TAG_unspecified_parameters DIE's.
972  MCOS->EmitIntValue(0, 1);
973  }
974 
975  // Add the NULL DIE terminating the Compile Unit DIE's.
976  MCOS->EmitIntValue(0, 1);
977 
978  // Now set the value of the symbol at the end of the info section.
979  MCOS->EmitLabel(InfoEnd);
980 }
981 
982 // When generating dwarf for assembly source files this emits the data for
983 // .debug_ranges section. We only emit one range list, which spans all of the
984 // executable sections of this file.
985 static void EmitGenDwarfRanges(MCStreamer *MCOS) {
986  MCContext &context = MCOS->getContext();
987  auto &Sections = context.getGenDwarfSectionSyms();
988 
989  const MCAsmInfo *AsmInfo = context.getAsmInfo();
990  int AddrSize = AsmInfo->getCodePointerSize();
991 
993 
994  for (MCSection *Sec : Sections) {
995  const MCSymbol *StartSymbol = Sec->getBeginSymbol();
996  MCSymbol *EndSymbol = Sec->getEndSymbol(context);
997  assert(StartSymbol && "StartSymbol must not be NULL");
998  assert(EndSymbol && "EndSymbol must not be NULL");
999 
1000  // Emit a base address selection entry for the start of this section
1001  const MCExpr *SectionStartAddr = MCSymbolRefExpr::create(
1002  StartSymbol, MCSymbolRefExpr::VK_None, context);
1003  MCOS->emitFill(AddrSize, 0xFF);
1004  MCOS->EmitValue(SectionStartAddr, AddrSize);
1005 
1006  // Emit a range list entry spanning this section
1007  const MCExpr *SectionSize = MakeStartMinusEndExpr(*MCOS,
1008  *StartSymbol, *EndSymbol, 0);
1009  MCOS->EmitIntValue(0, AddrSize);
1010  emitAbsValue(*MCOS, SectionSize, AddrSize);
1011  }
1012 
1013  // Emit end of list entry
1014  MCOS->EmitIntValue(0, AddrSize);
1015  MCOS->EmitIntValue(0, AddrSize);
1016 }
1017 
1018 //
1019 // When generating dwarf for assembly source files this emits the Dwarf
1020 // sections.
1021 //
1023  MCContext &context = MCOS->getContext();
1024 
1025  // Create the dwarf sections in this order (.debug_line already created).
1026  const MCAsmInfo *AsmInfo = context.getAsmInfo();
1027  bool CreateDwarfSectionSymbols =
1029  MCSymbol *LineSectionSymbol = nullptr;
1030  if (CreateDwarfSectionSymbols)
1031  LineSectionSymbol = MCOS->getDwarfLineTableSymbol(0);
1032  MCSymbol *AbbrevSectionSymbol = nullptr;
1033  MCSymbol *InfoSectionSymbol = nullptr;
1034  MCSymbol *RangesSectionSymbol = nullptr;
1035 
1036  // Create end symbols for each section, and remove empty sections
1037  MCOS->getContext().finalizeDwarfSections(*MCOS);
1038 
1039  // If there are no sections to generate debug info for, we don't need
1040  // to do anything
1041  if (MCOS->getContext().getGenDwarfSectionSyms().empty())
1042  return;
1043 
1044  // We only use the .debug_ranges section if we have multiple code sections,
1045  // and we are emitting a DWARF version which supports it.
1046  const bool UseRangesSection =
1047  MCOS->getContext().getGenDwarfSectionSyms().size() > 1 &&
1048  MCOS->getContext().getDwarfVersion() >= 3;
1049  CreateDwarfSectionSymbols |= UseRangesSection;
1050 
1052  if (CreateDwarfSectionSymbols) {
1053  InfoSectionSymbol = context.createTempSymbol();
1054  MCOS->EmitLabel(InfoSectionSymbol);
1055  }
1057  if (CreateDwarfSectionSymbols) {
1058  AbbrevSectionSymbol = context.createTempSymbol();
1059  MCOS->EmitLabel(AbbrevSectionSymbol);
1060  }
1061  if (UseRangesSection) {
1063  if (CreateDwarfSectionSymbols) {
1064  RangesSectionSymbol = context.createTempSymbol();
1065  MCOS->EmitLabel(RangesSectionSymbol);
1066  }
1067  }
1068 
1069  assert((RangesSectionSymbol != nullptr) || !UseRangesSection);
1070 
1072 
1073  // Output the data for .debug_aranges section.
1074  EmitGenDwarfAranges(MCOS, InfoSectionSymbol);
1075 
1076  if (UseRangesSection)
1077  EmitGenDwarfRanges(MCOS);
1078 
1079  // Output the data for .debug_abbrev section.
1080  EmitGenDwarfAbbrev(MCOS);
1081 
1082  // Output the data for .debug_info section.
1083  EmitGenDwarfInfo(MCOS, AbbrevSectionSymbol, LineSectionSymbol,
1084  RangesSectionSymbol);
1085 }
1086 
1087 //
1088 // When generating dwarf for assembly source files this is called when symbol
1089 // for a label is created. If this symbol is not a temporary and is in the
1090 // section that dwarf is being generated for, save the needed info to create
1091 // a dwarf label.
1092 //
1094  SourceMgr &SrcMgr, SMLoc &Loc) {
1095  // We won't create dwarf labels for temporary symbols.
1096  if (Symbol->isTemporary())
1097  return;
1098  MCContext &context = MCOS->getContext();
1099  // We won't create dwarf labels for symbols in sections that we are not
1100  // generating debug info for.
1101  if (!context.getGenDwarfSectionSyms().count(MCOS->getCurrentSectionOnly()))
1102  return;
1103 
1104  // The dwarf label's name does not have the symbol name's leading
1105  // underbar if any.
1106  StringRef Name = Symbol->getName();
1107  if (Name.startswith("_"))
1108  Name = Name.substr(1, Name.size()-1);
1109 
1110  // Get the dwarf file number to be used for the dwarf label.
1111  unsigned FileNumber = context.getGenDwarfFileNumber();
1112 
1113  // Finding the line number is the expensive part which is why we just don't
1114  // pass it in as for some symbols we won't create a dwarf label.
1115  unsigned CurBuffer = SrcMgr.FindBufferContainingLoc(Loc);
1116  unsigned LineNumber = SrcMgr.FindLineNumber(Loc, CurBuffer);
1117 
1118  // We create a temporary symbol for use for the AT_high_pc and AT_low_pc
1119  // values so that they don't have things like an ARM thumb bit from the
1120  // original symbol. So when used they won't get a low bit set after
1121  // relocation.
1122  MCSymbol *Label = context.createTempSymbol();
1123  MCOS->EmitLabel(Label);
1124 
1125  // Create and entry for the info and add it to the other entries.
1127  MCGenDwarfLabelEntry(Name, FileNumber, LineNumber, Label));
1128 }
1129 
1130 static int getDataAlignmentFactor(MCStreamer &streamer) {
1131  MCContext &context = streamer.getContext();
1132  const MCAsmInfo *asmInfo = context.getAsmInfo();
1133  int size = asmInfo->getCalleeSaveStackSlotSize();
1134  if (asmInfo->isStackGrowthDirectionUp())
1135  return size;
1136  else
1137  return -size;
1138 }
1139 
1140 static unsigned getSizeForEncoding(MCStreamer &streamer,
1141  unsigned symbolEncoding) {
1142  MCContext &context = streamer.getContext();
1143  unsigned format = symbolEncoding & 0x0f;
1144  switch (format) {
1145  default: llvm_unreachable("Unknown Encoding");
1148  return context.getAsmInfo()->getCodePointerSize();
1151  return 2;
1154  return 4;
1157  return 8;
1158  }
1159 }
1160 
1161 static void emitFDESymbol(MCObjectStreamer &streamer, const MCSymbol &symbol,
1162  unsigned symbolEncoding, bool isEH) {
1163  MCContext &context = streamer.getContext();
1164  const MCAsmInfo *asmInfo = context.getAsmInfo();
1165  const MCExpr *v = asmInfo->getExprForFDESymbol(&symbol,
1166  symbolEncoding,
1167  streamer);
1168  unsigned size = getSizeForEncoding(streamer, symbolEncoding);
1169  if (asmInfo->doDwarfFDESymbolsUseAbsDiff() && isEH)
1170  emitAbsValue(streamer, v, size);
1171  else
1172  streamer.EmitValue(v, size);
1173 }
1174 
1175 static void EmitPersonality(MCStreamer &streamer, const MCSymbol &symbol,
1176  unsigned symbolEncoding) {
1177  MCContext &context = streamer.getContext();
1178  const MCAsmInfo *asmInfo = context.getAsmInfo();
1179  const MCExpr *v = asmInfo->getExprForPersonalitySymbol(&symbol,
1180  symbolEncoding,
1181  streamer);
1182  unsigned size = getSizeForEncoding(streamer, symbolEncoding);
1183  streamer.EmitValue(v, size);
1184 }
1185 
1186 namespace {
1187 
1188 class FrameEmitterImpl {
1189  int CFAOffset = 0;
1190  int InitialCFAOffset = 0;
1191  bool IsEH;
1192  MCObjectStreamer &Streamer;
1193 
1194 public:
1195  FrameEmitterImpl(bool IsEH, MCObjectStreamer &Streamer)
1196  : IsEH(IsEH), Streamer(Streamer) {}
1197 
1198  /// Emit the unwind information in a compact way.
1199  void EmitCompactUnwind(const MCDwarfFrameInfo &frame);
1200 
1201  const MCSymbol &EmitCIE(const MCDwarfFrameInfo &F);
1202  void EmitFDE(const MCSymbol &cieStart, const MCDwarfFrameInfo &frame,
1203  bool LastInSection, const MCSymbol &SectionStart);
1204  void EmitCFIInstructions(ArrayRef<MCCFIInstruction> Instrs,
1205  MCSymbol *BaseLabel);
1206  void EmitCFIInstruction(const MCCFIInstruction &Instr);
1207 };
1208 
1209 } // end anonymous namespace
1210 
1211 static void emitEncodingByte(MCObjectStreamer &Streamer, unsigned Encoding) {
1212  Streamer.EmitIntValue(Encoding, 1);
1213 }
1214 
1215 void FrameEmitterImpl::EmitCFIInstruction(const MCCFIInstruction &Instr) {
1216  int dataAlignmentFactor = getDataAlignmentFactor(Streamer);
1217  auto *MRI = Streamer.getContext().getRegisterInfo();
1218 
1219  switch (Instr.getOperation()) {
1221  unsigned Reg1 = Instr.getRegister();
1222  unsigned Reg2 = Instr.getRegister2();
1223  if (!IsEH) {
1224  Reg1 = MRI->getDwarfRegNumFromDwarfEHRegNum(Reg1);
1225  Reg2 = MRI->getDwarfRegNumFromDwarfEHRegNum(Reg2);
1226  }
1227  Streamer.EmitIntValue(dwarf::DW_CFA_register, 1);
1228  Streamer.EmitULEB128IntValue(Reg1);
1229  Streamer.EmitULEB128IntValue(Reg2);
1230  return;
1231  }
1233  Streamer.EmitIntValue(dwarf::DW_CFA_GNU_window_save, 1);
1234  return;
1235 
1237  unsigned Reg = Instr.getRegister();
1238  Streamer.EmitIntValue(dwarf::DW_CFA_undefined, 1);
1239  Streamer.EmitULEB128IntValue(Reg);
1240  return;
1241  }
1244  const bool IsRelative =
1246 
1247  Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_offset, 1);
1248 
1249  if (IsRelative)
1250  CFAOffset += Instr.getOffset();
1251  else
1252  CFAOffset = -Instr.getOffset();
1253 
1254  Streamer.EmitULEB128IntValue(CFAOffset);
1255 
1256  return;
1257  }
1259  unsigned Reg = Instr.getRegister();
1260  if (!IsEH)
1261  Reg = MRI->getDwarfRegNumFromDwarfEHRegNum(Reg);
1262  Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa, 1);
1263  Streamer.EmitULEB128IntValue(Reg);
1264  CFAOffset = -Instr.getOffset();
1265  Streamer.EmitULEB128IntValue(CFAOffset);
1266 
1267  return;
1268  }
1270  unsigned Reg = Instr.getRegister();
1271  if (!IsEH)
1272  Reg = MRI->getDwarfRegNumFromDwarfEHRegNum(Reg);
1273  Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_register, 1);
1274  Streamer.EmitULEB128IntValue(Reg);
1275 
1276  return;
1277  }
1280  const bool IsRelative =
1282 
1283  unsigned Reg = Instr.getRegister();
1284  if (!IsEH)
1285  Reg = MRI->getDwarfRegNumFromDwarfEHRegNum(Reg);
1286 
1287  int Offset = Instr.getOffset();
1288  if (IsRelative)
1289  Offset -= CFAOffset;
1290  Offset = Offset / dataAlignmentFactor;
1291 
1292  if (Offset < 0) {
1293  Streamer.EmitIntValue(dwarf::DW_CFA_offset_extended_sf, 1);
1294  Streamer.EmitULEB128IntValue(Reg);
1295  Streamer.EmitSLEB128IntValue(Offset);
1296  } else if (Reg < 64) {
1297  Streamer.EmitIntValue(dwarf::DW_CFA_offset + Reg, 1);
1298  Streamer.EmitULEB128IntValue(Offset);
1299  } else {
1300  Streamer.EmitIntValue(dwarf::DW_CFA_offset_extended, 1);
1301  Streamer.EmitULEB128IntValue(Reg);
1302  Streamer.EmitULEB128IntValue(Offset);
1303  }
1304  return;
1305  }
1307  Streamer.EmitIntValue(dwarf::DW_CFA_remember_state, 1);
1308  return;
1310  Streamer.EmitIntValue(dwarf::DW_CFA_restore_state, 1);
1311  return;
1313  unsigned Reg = Instr.getRegister();
1314  Streamer.EmitIntValue(dwarf::DW_CFA_same_value, 1);
1315  Streamer.EmitULEB128IntValue(Reg);
1316  return;
1317  }
1319  unsigned Reg = Instr.getRegister();
1320  if (!IsEH)
1321  Reg = MRI->getDwarfRegNumFromDwarfEHRegNum(Reg);
1322  Streamer.EmitIntValue(dwarf::DW_CFA_restore | Reg, 1);
1323  return;
1324  }
1326  Streamer.EmitIntValue(dwarf::DW_CFA_GNU_args_size, 1);
1327  Streamer.EmitULEB128IntValue(Instr.getOffset());
1328  return;
1329 
1331  Streamer.EmitBytes(Instr.getValues());
1332  return;
1333  }
1334  llvm_unreachable("Unhandled case in switch");
1335 }
1336 
1337 /// Emit frame instructions to describe the layout of the frame.
1338 void FrameEmitterImpl::EmitCFIInstructions(ArrayRef<MCCFIInstruction> Instrs,
1339  MCSymbol *BaseLabel) {
1340  for (const MCCFIInstruction &Instr : Instrs) {
1341  MCSymbol *Label = Instr.getLabel();
1342  // Throw out move if the label is invalid.
1343  if (Label && !Label->isDefined()) continue; // Not emitted, in dead code.
1344 
1345  // Advance row if new location.
1346  if (BaseLabel && Label) {
1347  MCSymbol *ThisSym = Label;
1348  if (ThisSym != BaseLabel) {
1349  Streamer.EmitDwarfAdvanceFrameAddr(BaseLabel, ThisSym);
1350  BaseLabel = ThisSym;
1351  }
1352  }
1353 
1354  EmitCFIInstruction(Instr);
1355  }
1356 }
1357 
1358 /// Emit the unwind information in a compact way.
1359 void FrameEmitterImpl::EmitCompactUnwind(const MCDwarfFrameInfo &Frame) {
1360  MCContext &Context = Streamer.getContext();
1361  const MCObjectFileInfo *MOFI = Context.getObjectFileInfo();
1362 
1363  // range-start range-length compact-unwind-enc personality-func lsda
1364  // _foo LfooEnd-_foo 0x00000023 0 0
1365  // _bar LbarEnd-_bar 0x00000025 __gxx_personality except_tab1
1366  //
1367  // .section __LD,__compact_unwind,regular,debug
1368  //
1369  // # compact unwind for _foo
1370  // .quad _foo
1371  // .set L1,LfooEnd-_foo
1372  // .long L1
1373  // .long 0x01010001
1374  // .quad 0
1375  // .quad 0
1376  //
1377  // # compact unwind for _bar
1378  // .quad _bar
1379  // .set L2,LbarEnd-_bar
1380  // .long L2
1381  // .long 0x01020011
1382  // .quad __gxx_personality
1383  // .quad except_tab1
1384 
1385  uint32_t Encoding = Frame.CompactUnwindEncoding;
1386  if (!Encoding) return;
1387  bool DwarfEHFrameOnly = (Encoding == MOFI->getCompactUnwindDwarfEHFrameOnly());
1388 
1389  // The encoding needs to know we have an LSDA.
1390  if (!DwarfEHFrameOnly && Frame.Lsda)
1391  Encoding |= 0x40000000;
1392 
1393  // Range Start
1394  unsigned FDEEncoding = MOFI->getFDEEncoding();
1395  unsigned Size = getSizeForEncoding(Streamer, FDEEncoding);
1396  Streamer.EmitSymbolValue(Frame.Begin, Size);
1397 
1398  // Range Length
1399  const MCExpr *Range = MakeStartMinusEndExpr(Streamer, *Frame.Begin,
1400  *Frame.End, 0);
1401  emitAbsValue(Streamer, Range, 4);
1402 
1403  // Compact Encoding
1404  Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_udata4);
1405  Streamer.EmitIntValue(Encoding, Size);
1406 
1407  // Personality Function
1408  Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_absptr);
1409  if (!DwarfEHFrameOnly && Frame.Personality)
1410  Streamer.EmitSymbolValue(Frame.Personality, Size);
1411  else
1412  Streamer.EmitIntValue(0, Size); // No personality fn
1413 
1414  // LSDA
1415  Size = getSizeForEncoding(Streamer, Frame.LsdaEncoding);
1416  if (!DwarfEHFrameOnly && Frame.Lsda)
1417  Streamer.EmitSymbolValue(Frame.Lsda, Size);
1418  else
1419  Streamer.EmitIntValue(0, Size); // No LSDA
1420 }
1421 
1422 static unsigned getCIEVersion(bool IsEH, unsigned DwarfVersion) {
1423  if (IsEH)
1424  return 1;
1425  switch (DwarfVersion) {
1426  case 2:
1427  return 1;
1428  case 3:
1429  return 3;
1430  case 4:
1431  case 5:
1432  return 4;
1433  }
1434  llvm_unreachable("Unknown version");
1435 }
1436 
1437 const MCSymbol &FrameEmitterImpl::EmitCIE(const MCDwarfFrameInfo &Frame) {
1438  MCContext &context = Streamer.getContext();
1439  const MCRegisterInfo *MRI = context.getRegisterInfo();
1440  const MCObjectFileInfo *MOFI = context.getObjectFileInfo();
1441 
1442  MCSymbol *sectionStart = context.createTempSymbol();
1443  Streamer.EmitLabel(sectionStart);
1444 
1445  MCSymbol *sectionEnd = context.createTempSymbol();
1446 
1447  // Length
1448  const MCExpr *Length =
1449  MakeStartMinusEndExpr(Streamer, *sectionStart, *sectionEnd, 4);
1450  emitAbsValue(Streamer, Length, 4);
1451 
1452  // CIE ID
1453  unsigned CIE_ID = IsEH ? 0 : -1;
1454  Streamer.EmitIntValue(CIE_ID, 4);
1455 
1456  // Version
1457  uint8_t CIEVersion = getCIEVersion(IsEH, context.getDwarfVersion());
1458  Streamer.EmitIntValue(CIEVersion, 1);
1459 
1460  // Augmentation String
1461  SmallString<8> Augmentation;
1462  if (IsEH) {
1463  Augmentation += "z";
1464  if (Frame.Personality)
1465  Augmentation += "P";
1466  if (Frame.Lsda)
1467  Augmentation += "L";
1468  Augmentation += "R";
1469  if (Frame.IsSignalFrame)
1470  Augmentation += "S";
1471  Streamer.EmitBytes(Augmentation);
1472  }
1473  Streamer.EmitIntValue(0, 1);
1474 
1475  if (CIEVersion >= 4) {
1476  // Address Size
1477  Streamer.EmitIntValue(context.getAsmInfo()->getCodePointerSize(), 1);
1478 
1479  // Segment Descriptor Size
1480  Streamer.EmitIntValue(0, 1);
1481  }
1482 
1483  // Code Alignment Factor
1484  Streamer.EmitULEB128IntValue(context.getAsmInfo()->getMinInstAlignment());
1485 
1486  // Data Alignment Factor
1487  Streamer.EmitSLEB128IntValue(getDataAlignmentFactor(Streamer));
1488 
1489  // Return Address Register
1490  unsigned RAReg = Frame.RAReg;
1491  if (RAReg == static_cast<unsigned>(INT_MAX))
1492  RAReg = MRI->getDwarfRegNum(MRI->getRARegister(), IsEH);
1493 
1494  if (CIEVersion == 1) {
1495  assert(RAReg <= 255 &&
1496  "DWARF 2 encodes return_address_register in one byte");
1497  Streamer.EmitIntValue(RAReg, 1);
1498  } else {
1499  Streamer.EmitULEB128IntValue(RAReg);
1500  }
1501 
1502  // Augmentation Data Length (optional)
1503  unsigned augmentationLength = 0;
1504  if (IsEH) {
1505  if (Frame.Personality) {
1506  // Personality Encoding
1507  augmentationLength += 1;
1508  // Personality
1509  augmentationLength +=
1510  getSizeForEncoding(Streamer, Frame.PersonalityEncoding);
1511  }
1512  if (Frame.Lsda)
1513  augmentationLength += 1;
1514  // Encoding of the FDE pointers
1515  augmentationLength += 1;
1516 
1517  Streamer.EmitULEB128IntValue(augmentationLength);
1518 
1519  // Augmentation Data (optional)
1520  if (Frame.Personality) {
1521  // Personality Encoding
1522  emitEncodingByte(Streamer, Frame.PersonalityEncoding);
1523  // Personality
1524  EmitPersonality(Streamer, *Frame.Personality, Frame.PersonalityEncoding);
1525  }
1526 
1527  if (Frame.Lsda)
1528  emitEncodingByte(Streamer, Frame.LsdaEncoding);
1529 
1530  // Encoding of the FDE pointers
1531  emitEncodingByte(Streamer, MOFI->getFDEEncoding());
1532  }
1533 
1534  // Initial Instructions
1535 
1536  const MCAsmInfo *MAI = context.getAsmInfo();
1537  if (!Frame.IsSimple) {
1538  const std::vector<MCCFIInstruction> &Instructions =
1539  MAI->getInitialFrameState();
1540  EmitCFIInstructions(Instructions, nullptr);
1541  }
1542 
1543  InitialCFAOffset = CFAOffset;
1544 
1545  // Padding
1546  Streamer.EmitValueToAlignment(IsEH ? 4 : MAI->getCodePointerSize());
1547 
1548  Streamer.EmitLabel(sectionEnd);
1549  return *sectionStart;
1550 }
1551 
1552 void FrameEmitterImpl::EmitFDE(const MCSymbol &cieStart,
1553  const MCDwarfFrameInfo &frame,
1554  bool LastInSection,
1555  const MCSymbol &SectionStart) {
1556  MCContext &context = Streamer.getContext();
1557  MCSymbol *fdeStart = context.createTempSymbol();
1558  MCSymbol *fdeEnd = context.createTempSymbol();
1559  const MCObjectFileInfo *MOFI = context.getObjectFileInfo();
1560 
1561  CFAOffset = InitialCFAOffset;
1562 
1563  // Length
1564  const MCExpr *Length = MakeStartMinusEndExpr(Streamer, *fdeStart, *fdeEnd, 0);
1565  emitAbsValue(Streamer, Length, 4);
1566 
1567  Streamer.EmitLabel(fdeStart);
1568 
1569  // CIE Pointer
1570  const MCAsmInfo *asmInfo = context.getAsmInfo();
1571  if (IsEH) {
1572  const MCExpr *offset =
1573  MakeStartMinusEndExpr(Streamer, cieStart, *fdeStart, 0);
1574  emitAbsValue(Streamer, offset, 4);
1575  } else if (!asmInfo->doesDwarfUseRelocationsAcrossSections()) {
1576  const MCExpr *offset =
1577  MakeStartMinusEndExpr(Streamer, SectionStart, cieStart, 0);
1578  emitAbsValue(Streamer, offset, 4);
1579  } else {
1580  Streamer.EmitSymbolValue(&cieStart, 4);
1581  }
1582 
1583  // PC Begin
1584  unsigned PCEncoding =
1586  unsigned PCSize = getSizeForEncoding(Streamer, PCEncoding);
1587  emitFDESymbol(Streamer, *frame.Begin, PCEncoding, IsEH);
1588 
1589  // PC Range
1590  const MCExpr *Range =
1591  MakeStartMinusEndExpr(Streamer, *frame.Begin, *frame.End, 0);
1592  emitAbsValue(Streamer, Range, PCSize);
1593 
1594  if (IsEH) {
1595  // Augmentation Data Length
1596  unsigned augmentationLength = 0;
1597 
1598  if (frame.Lsda)
1599  augmentationLength += getSizeForEncoding(Streamer, frame.LsdaEncoding);
1600 
1601  Streamer.EmitULEB128IntValue(augmentationLength);
1602 
1603  // Augmentation Data
1604  if (frame.Lsda)
1605  emitFDESymbol(Streamer, *frame.Lsda, frame.LsdaEncoding, true);
1606  }
1607 
1608  // Call Frame Instructions
1609  EmitCFIInstructions(frame.Instructions, frame.Begin);
1610 
1611  // Padding
1612  // The size of a .eh_frame section has to be a multiple of the alignment
1613  // since a null CIE is interpreted as the end. Old systems overaligned
1614  // .eh_frame, so we do too and account for it in the last FDE.
1615  unsigned Align = LastInSection ? asmInfo->getCodePointerSize() : PCSize;
1616  Streamer.EmitValueToAlignment(Align);
1617 
1618  Streamer.EmitLabel(fdeEnd);
1619 }
1620 
1621 namespace {
1622 
1623 struct CIEKey {
1624  static const CIEKey getEmptyKey() {
1625  return CIEKey(nullptr, 0, -1, false, false, static_cast<unsigned>(INT_MAX));
1626  }
1627 
1628  static const CIEKey getTombstoneKey() {
1629  return CIEKey(nullptr, -1, 0, false, false, static_cast<unsigned>(INT_MAX));
1630  }
1631 
1632  CIEKey(const MCSymbol *Personality, unsigned PersonalityEncoding,
1633  unsigned LSDAEncoding, bool IsSignalFrame, bool IsSimple,
1634  unsigned RAReg)
1635  : Personality(Personality), PersonalityEncoding(PersonalityEncoding),
1636  LsdaEncoding(LSDAEncoding), IsSignalFrame(IsSignalFrame),
1637  IsSimple(IsSimple), RAReg(RAReg) {}
1638 
1639  explicit CIEKey(const MCDwarfFrameInfo &Frame)
1640  : Personality(Frame.Personality),
1641  PersonalityEncoding(Frame.PersonalityEncoding),
1642  LsdaEncoding(Frame.LsdaEncoding), IsSignalFrame(Frame.IsSignalFrame),
1643  IsSimple(Frame.IsSimple), RAReg(Frame.RAReg) {}
1644 
1645  const MCSymbol *Personality;
1646  unsigned PersonalityEncoding;
1647  unsigned LsdaEncoding;
1648  bool IsSignalFrame;
1649  bool IsSimple;
1650  unsigned RAReg;
1651 };
1652 
1653 } // end anonymous namespace
1654 
1655 namespace llvm {
1656 
1657 template <> struct DenseMapInfo<CIEKey> {
1658  static CIEKey getEmptyKey() { return CIEKey::getEmptyKey(); }
1659  static CIEKey getTombstoneKey() { return CIEKey::getTombstoneKey(); }
1660 
1661  static unsigned getHashValue(const CIEKey &Key) {
1662  return static_cast<unsigned>(
1663  hash_combine(Key.Personality, Key.PersonalityEncoding, Key.LsdaEncoding,
1664  Key.IsSignalFrame, Key.IsSimple, Key.RAReg));
1665  }
1666 
1667  static bool isEqual(const CIEKey &LHS, const CIEKey &RHS) {
1668  return LHS.Personality == RHS.Personality &&
1669  LHS.PersonalityEncoding == RHS.PersonalityEncoding &&
1670  LHS.LsdaEncoding == RHS.LsdaEncoding &&
1671  LHS.IsSignalFrame == RHS.IsSignalFrame &&
1672  LHS.IsSimple == RHS.IsSimple &&
1673  LHS.RAReg == RHS.RAReg;
1674  }
1675 };
1676 
1677 } // end namespace llvm
1678 
1680  bool IsEH) {
1681  Streamer.generateCompactUnwindEncodings(MAB);
1682 
1683  MCContext &Context = Streamer.getContext();
1684  const MCObjectFileInfo *MOFI = Context.getObjectFileInfo();
1685  const MCAsmInfo *AsmInfo = Context.getAsmInfo();
1686  FrameEmitterImpl Emitter(IsEH, Streamer);
1687  ArrayRef<MCDwarfFrameInfo> FrameArray = Streamer.getDwarfFrameInfos();
1688 
1689  // Emit the compact unwind info if available.
1690  bool NeedsEHFrameSection = !MOFI->getSupportsCompactUnwindWithoutEHFrame();
1691  if (IsEH && MOFI->getCompactUnwindSection()) {
1692  bool SectionEmitted = false;
1693  for (const MCDwarfFrameInfo &Frame : FrameArray) {
1694  if (Frame.CompactUnwindEncoding == 0) continue;
1695  if (!SectionEmitted) {
1696  Streamer.SwitchSection(MOFI->getCompactUnwindSection());
1697  Streamer.EmitValueToAlignment(AsmInfo->getCodePointerSize());
1698  SectionEmitted = true;
1699  }
1700  NeedsEHFrameSection |=
1701  Frame.CompactUnwindEncoding ==
1703  Emitter.EmitCompactUnwind(Frame);
1704  }
1705  }
1706 
1707  if (!NeedsEHFrameSection) return;
1708 
1709  MCSection &Section =
1710  IsEH ? *const_cast<MCObjectFileInfo *>(MOFI)->getEHFrameSection()
1711  : *MOFI->getDwarfFrameSection();
1712 
1713  Streamer.SwitchSection(&Section);
1714  MCSymbol *SectionStart = Context.createTempSymbol();
1715  Streamer.EmitLabel(SectionStart);
1716 
1718 
1719  const MCSymbol *DummyDebugKey = nullptr;
1720  bool CanOmitDwarf = MOFI->getOmitDwarfIfHaveCompactUnwind();
1721  for (auto I = FrameArray.begin(), E = FrameArray.end(); I != E;) {
1722  const MCDwarfFrameInfo &Frame = *I;
1723  ++I;
1724  if (CanOmitDwarf && Frame.CompactUnwindEncoding !=
1726  // Don't generate an EH frame if we don't need one. I.e., it's taken care
1727  // of by the compact unwind encoding.
1728  continue;
1729 
1730  CIEKey Key(Frame);
1731  const MCSymbol *&CIEStart = IsEH ? CIEStarts[Key] : DummyDebugKey;
1732  if (!CIEStart)
1733  CIEStart = &Emitter.EmitCIE(Frame);
1734 
1735  Emitter.EmitFDE(*CIEStart, Frame, I == E, *SectionStart);
1736  }
1737 }
1738 
1740  uint64_t AddrDelta) {
1741  MCContext &Context = Streamer.getContext();
1742  SmallString<256> Tmp;
1743  raw_svector_ostream OS(Tmp);
1744  MCDwarfFrameEmitter::EncodeAdvanceLoc(Context, AddrDelta, OS);
1745  Streamer.EmitBytes(OS.str());
1746 }
1747 
1749  uint64_t AddrDelta,
1750  raw_ostream &OS) {
1751  // Scale the address delta by the minimum instruction length.
1752  AddrDelta = ScaleAddrDelta(Context, AddrDelta);
1753 
1754  if (AddrDelta == 0) {
1755  } else if (isUIntN(6, AddrDelta)) {
1756  uint8_t Opcode = dwarf::DW_CFA_advance_loc | AddrDelta;
1757  OS << Opcode;
1758  } else if (isUInt<8>(AddrDelta)) {
1759  OS << uint8_t(dwarf::DW_CFA_advance_loc1);
1760  OS << uint8_t(AddrDelta);
1761  } else if (isUInt<16>(AddrDelta)) {
1762  OS << uint8_t(dwarf::DW_CFA_advance_loc2);
1763  if (Context.getAsmInfo()->isLittleEndian())
1764  support::endian::Writer<support::little>(OS).write<uint16_t>(AddrDelta);
1765  else
1766  support::endian::Writer<support::big>(OS).write<uint16_t>(AddrDelta);
1767  } else {
1768  assert(isUInt<32>(AddrDelta));
1769  OS << uint8_t(dwarf::DW_CFA_advance_loc4);
1770  if (Context.getAsmInfo()->isLittleEndian())
1772  else
1773  support::endian::Writer<support::big>(OS).write<uint32_t>(AddrDelta);
1774  }
1775 }
static const MCExpr * forceExpAbs(MCStreamer &OS, const MCExpr *Expr)
Definition: MCDwarf.cpp:291
const MCAsmInfo * getAsmInfo() const
Definition: MCContext.h:288
void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry &E)
Definition: MCContext.h:584
constexpr bool isUInt< 32 >(uint64_t x)
Definition: MathExtras.h:341
bool isOSDarwin() const
isOSDarwin - Is this a "Darwin" OS (OS X, iOS, or watchOS).
Definition: Triple.h:470
Instances of this class represent a uniqued identifier for a section in the current translation unit...
Definition: MCSection.h:39
constexpr char Align[]
Key for Kernel::Arg::Metadata::mAlign.
static int getDataAlignmentFactor(MCStreamer &streamer)
Definition: MCDwarf.cpp:1130
unsigned FindBufferContainingLoc(SMLoc Loc) const
Return the ID of the buffer containing the specified location.
Definition: SourceMgr.cpp:78
void EmitBytes(StringRef Data) override
Emit the bytes in Data into the output.
LLVMContext & Context
static CIEKey getTombstoneKey()
Definition: MCDwarf.cpp:1659
#define DWARF2_FLAG_PROLOGUE_END
Definition: MCDwarf.h:77
static void Make(MCObjectStreamer *MCOS, MCSection *Section)
Definition: MCDwarf.cpp:88
static const MCSymbolRefExpr * create(const MCSymbol *Symbol, MCContext &Ctx)
Definition: MCExpr.h:313
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
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:145
MCSection * getDwarfLineSection() const
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:42
iterator begin() const
Definition: ArrayRef.h:137
LLVM_ATTRIBUTE_ALWAYS_INLINE size_type size() const
Definition: SmallVector.h:136
const SmallVectorImpl< MCDwarfFile > & getMCDwarfFiles(unsigned CUID=0)
Definition: MCContext.h:516
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE size_t size() const
size - Get the string size.
Definition: StringRef.h:138
SourceMgr SrcMgr
Definition: Error.cpp:23
virtual void EmitBytes(StringRef Data)
Emit the bytes in Data into the output.
Definition: MCStreamer.cpp:937
format_object< Ts... > format(const char *Fmt, const Ts &... Vals)
These are helper functions used to produce formatted output.
Definition: Format.h:124
bool needsDwarfSectionOffsetDirective() const
Definition: MCAsmInfo.h:454
static void EmitAdvanceLoc(MCObjectStreamer &Streamer, uint64_t AddrDelta)
Definition: MCDwarf.cpp:1739
MCSection * getDwarfLineStrSection() const
A raw_ostream that writes to an SmallVector or SmallString.
Definition: raw_ostream.h:489
void Emit(MCStreamer &MCOS, MCDwarfLineTableParams Params) const
Definition: MCDwarf.cpp:260
F(f)
MCSection * getDwarfARangesSection() const
MCDwarfLineStr(MCContext &Ctx)
Construct an instance that can emit .debug_line_str (for use in a normal v5 line table).
Definition: MCDwarf.cpp:58
uint16_t getDwarfVersion() const
Definition: MCContext.h:600
#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:585
virtual MCSymbol * getDwarfLineTableSymbol(unsigned CUID)
Definition: MCStreamer.cpp:208
bool getSupportsCompactUnwindWithoutEHFrame() const
static void EmitGenDwarfInfo(MCStreamer *MCOS, const MCSymbol *AbbrevSectionSymbol, const MCSymbol *LineSectionSymbol, const MCSymbol *RangesSectionSymbol)
Definition: MCDwarf.cpp:817
unsigned LsdaEncoding
Definition: MCDwarf.h:524
StringRef getDwarfDebugFlags()
Definition: MCContext.h:589
std::vector< MCDwarfLineEntry > MCDwarfLineEntryCollection
Definition: MCDwarf.h:177
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:601
void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel, const MCSymbol *Label, unsigned PointerSize)
std::vector< MCCFIInstruction > Instructions
Definition: MCDwarf.h:521
const std::vector< MCGenDwarfLabelEntry > & getMCGenDwarfLabelEntries() const
Definition: MCContext.h:580
MCContext & getContext() const
Definition: MCStreamer.h:246
#define DWARF2_FLAG_IS_STMT
Definition: MCDwarf.h:75
StringRef getDwarfDebugProducer()
Definition: MCContext.h:592
std::string Name
Definition: MCDwarf.h:51
virtual const MCExpr * getExprForPersonalitySymbol(const MCSymbol *Sym, unsigned Encoding, MCStreamer &Streamer) const
Definition: MCAsmInfo.cpp:68
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:451
ABS - Determine the unsigned absolute value of a signed integer value of the same bitwidth...
Definition: ISDOpcodes.h:369
void finalizeDwarfSections(MCStreamer &MCOS)
Remove empty sections from SectionStartEndSyms, to avoid generating useless debug info for them...
Definition: MCContext.cpp:558
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:36
MCSymbol * Begin
Definition: MCDwarf.h:517
uint8_t DWARF2LineRange
Range of line offsets in a special line info. opcode.
Definition: MCDwarf.h:203
Reg
All possible values of the reg field in the ModR/M byte.
const MCSymbol * Lsda
Definition: MCDwarf.h:520
int getDwarfRegNum(unsigned RegNum, bool isEH) const
Map a target register to an equivalent dwarf register number.
unsigned getCompactUnwindDwarfEHFrameOnly() const
static void emitFDESymbol(MCObjectStreamer &streamer, const MCSymbol &symbol, unsigned symbolEncoding, bool isEH)
Definition: MCDwarf.cpp:1161
MCDwarfLineTable & getMCDwarfLineTable(unsigned CUID)
Definition: MCContext.h:506
MCSection * getDwarfFrameSection() const
unsigned getFile(StringRef &Directory, StringRef &FileName, MD5::MD5Result *Checksum, unsigned FileNumber=0)
Definition: MCDwarf.cpp:500
const SmallVectorImpl< std::string > & getMCDwarfDirs(unsigned CUID=0)
Definition: MCContext.h:520
bool hasAggressiveSymbolFolding() const
Definition: MCAsmInfo.h:513
bool getOmitDwarfIfHaveCompactUnwind() const
virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value)
Emit an assignment of Value to Symbol.
Definition: MCStreamer.cpp:832
StringRef str() const
Explicit conversion to StringRef.
Definition: SmallString.h:267
Context object for machine code objects.
Definition: MCContext.h:61
Key
PAL metadata keys.
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool startswith(StringRef Prefix) const
Check if this string starts with the given Prefix.
Definition: StringRef.h:267
static void EmitGenDwarfAbbrev(MCStreamer *MCOS)
Definition: MCDwarf.cpp:691
void write(raw_ostream &OS) const
Utility for building string tables with deduplicated suffixes.
unsigned getDwarfCompileUnitID()
Definition: MCContext.h:531
size_t add(CachedHashStringRef S)
Add a string to the builder.
const std::map< unsigned, MCDwarfLineTable > & getMCDwarfLineTables() const
Definition: MCContext.h:502
Streaming object file generation interface.
bool doesDwarfUseRelocationsAcrossSections() const
Definition: MCAsmInfo.h:575
unsigned getFile(StringRef &Directory, StringRef &FileName, MD5::MD5Result *Checksum, unsigned FileNumber=0)
Definition: MCDwarf.cpp:506
Instances of this class represent the information from a dwarf .loc directive.
Definition: MCDwarf.h:63
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:133
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
MCSection * getCompactUnwindSection() const
SmallString - A SmallString is just a SmallVector with methods and accessors that make it work better...
Definition: SmallString.h:26
virtual void EmitBinaryData(StringRef Data)
Functionally identical to EmitBytes.
Definition: MCStreamer.cpp:938
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:598
unsigned getGenDwarfFileNumber()
Definition: MCContext.h:564
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:110
MCSymbol * getLabel() const
Definition: MCDwarf.h:486
void EmitValue(const MCExpr *Value, unsigned Size, SMLoc Loc=SMLoc())
Definition: MCStreamer.cpp:141
MCSection * getDwarfAbbrevSection() const
static const MCBinaryExpr * create(Opcode Op, const MCExpr *LHS, const MCExpr *RHS, MCContext &Ctx, SMLoc Loc=SMLoc())
Definition: MCExpr.cpp:148
MCRegisterInfo base class - We assume that the target defines a static array of MCRegisterDesc object...
This class is intended to be used as a base class for asm properties and features specific to the tar...
Definition: MCAsmInfo.h:56
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:596
static unsigned getSizeForEncoding(MCStreamer &streamer, unsigned symbolEncoding)
Definition: MCDwarf.cpp:1140
Streaming machine code generation interface.
Definition: MCStreamer.h:181
static unsigned getCIEVersion(bool IsEH, unsigned DwarfVersion)
Definition: MCDwarf.cpp:1422
static void EmitAbbrev(MCStreamer *MCOS, uint64_t Name, uint64_t Form)
Definition: MCDwarf.cpp:684
MCSymbol * createTempSymbol(bool CanBeUnnamed=true)
Create and return a new assembler temporary symbol with a unique but unspecified name.
Definition: MCContext.cpp:215
uint8_t DWARF2LineOpcodeBase
First special line opcode - leave room for the standard opcodes.
Definition: MCDwarf.h:198
* if(!EatIfPresent(lltok::kw_thread_local)) return false
ParseOptionalThreadLocal := /*empty.
constexpr bool isUInt< 8 >(uint64_t x)
Definition: MathExtras.h:335
unsigned const MachineRegisterInfo * MRI
void EmitLabel(MCSymbol *Symbol, SMLoc Loc=SMLoc()) override
Emit a label for Symbol into the current section.
void write(ArrayRef< value_type > Vals)
Definition: EndianStream.h:30
unsigned getRegister2() const
Definition: MCDwarf.h:496
void finalizeInOrder()
Finalize the string table without reording it.
#define DWARF2_FLAG_EPILOGUE_BEGIN
Definition: MCDwarf.h:78
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:149
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
virtual void SwitchSection(MCSection *Section, const MCExpr *Subsection=nullptr)
Set the current section where code is being emitted to Section.
Definition: MCStreamer.cpp:959
static void emitAbsValue(MCStreamer &OS, const MCExpr *Value, unsigned Size)
Definition: MCDwarf.cpp:302
unsigned getFDEEncoding() const
static void EmitDwarfLineTable(MCObjectStreamer *MCOS, MCSection *Section, const MCLineSection::MCDwarfLineEntryCollection &LineEntries)
Definition: MCDwarf.cpp:151
int getOffset() const
Definition: MCDwarf.h:501
static void EmitGenDwarfAranges(MCStreamer *MCOS, const MCSymbol *InfoSectionSymbol)
Definition: MCDwarf.cpp:746
bool isTemporary() const
isTemporary - Check if this is an assembler temporary symbol.
Definition: MCSymbol.h:220
OpType getOperation() const
Definition: MCDwarf.h:485
static const unsigned End
const MCObjectFileInfo * getObjectFileInfo() const
Definition: MCContext.h:292
#define DWARF2_FLAG_BASIC_BLOCK
Definition: MCDwarf.h:76
bool doDwarfFDESymbolsUseAbsDiff() const
Definition: MCAsmInfo.h:579
const MCDwarfLoc & getCurrentDwarfLoc()
Definition: MCContext.h:560
StringRef parent_path(StringRef path, Style style=Style::native)
Get parent path.
Definition: Path.cpp:477
unsigned PersonalityEncoding
Definition: MCDwarf.h:523
This owns the files read by a parser, handles include stacks, and handles diagnostic wrangling...
Definition: SourceMgr.h:41
StringRef getValues() const
Definition: MCDwarf.h:508
StringRef toStringRef(bool B)
Construct a string ref from a boolean.
Definition: StringExtras.h:43
int8_t DWARF2LineBase
Minimum line offset in a special line info.
Definition: MCDwarf.h:201
StringRef get_separator(Style style=Style::native)
Return the preferred separator for this platform.
Definition: Path.cpp:612
void generateCompactUnwindEncodings(MCAsmBackend *MAB)
Definition: MCStreamer.cpp:102
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
void clearDwarfLocSeen()
Definition: MCContext.h:557
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.
StringRef getCompilationDir() const
Get the compilation directory for DW_AT_comp_dir The compilation directory should be set with setComp...
Definition: MCContext.h:482
unsigned getRegister() const
Definition: MCDwarf.h:488
const SetVector< MCSection * > & getGenDwarfSectionSyms()
Definition: MCContext.h:570
const std::vector< MCCFIInstruction > & getInitialFrameState() const
Definition: MCAsmInfo.h:587
static unsigned getHashValue(const CIEKey &Key)
Definition: MCDwarf.cpp:1661
void EmitCU(MCObjectStreamer *MCOS, MCDwarfLineTableParams Params, Optional< MCDwarfLineStr > &LineStr) const
Definition: MCDwarf.cpp:486
unsigned encodeULEB128(uint64_t Value, raw_ostream &OS, unsigned PadTo=0)
Utility function to encode a ULEB128 value to an output stream.
Definition: LEB128.h:81
unsigned encodeSLEB128(int64_t Value, raw_ostream &OS, unsigned PadTo=0)
Utility function to encode a SLEB128 value to an output stream.
Definition: LEB128.h:24
unsigned getMinInstAlignment() const
Definition: MCAsmInfo.h:463
constexpr size_t array_lengthof(T(&)[N])
Find the length of an array.
Definition: STLExtras.h:721
static bool isEqual(const CIEKey &LHS, const CIEKey &RHS)
Definition: MCDwarf.cpp:1667
iterator end() const
Definition: ArrayRef.h:138
MCSymbol * getBeginSymbol()
Definition: MCSection.h:106
const Triple & getTargetTriple() const
StringRef str()
Return a StringRef for the vector contents.
Definition: raw_ostream.h:514
static void EncodeAdvanceLoc(MCContext &Context, uint64_t AddrDelta, raw_ostream &OS)
Definition: MCDwarf.cpp:1748
MCSection * getDwarfInfoSection() const
uint32_t CompactUnwindEncoding
Definition: MCDwarf.h:525
static void EmitGenDwarfRanges(MCStreamer *MCOS)
Definition: MCDwarf.cpp:985
bool getDwarfLocSeen()
Definition: MCContext.h:559
This file contains constants used for implementing Dwarf debug support.
bool isDefined() const
isDefined - Check if this symbol is defined (i.e., it has an address).
Definition: MCSymbol.h:248
MCSection * getCurrentSectionOnly() const
Definition: MCStreamer.h:328
static CIEKey getEmptyKey()
Definition: MCDwarf.cpp:1658
hash_code hash_combine(const Ts &...args)
Combine values into a single hash_code.
Definition: Hashing.h:602
static void Emit(MCStreamer *MCOS)
Definition: MCDwarf.cpp:1022
iterator insert(iterator I, T &&Elt)
Definition: SmallVector.h:480
#define DWARF2_LINE_DEFAULT_IS_STMT
Definition: MCDwarf.h:73
unsigned FindLineNumber(SMLoc Loc, unsigned BufferID=0) const
Find the line number for the specified location in the specified file.
Definition: SourceMgr.h:150
bool isStackGrowthDirectionUp() const
True if target stack grow up.
Definition: MCAsmInfo.h:395
static uint64_t ScaleAddrDelta(MCContext &Context, uint64_t AddrDelta)
Definition: MCDwarf.cpp:72
Instances of this class represent the line information for the dwarf line table entries.
Definition: MCDwarf.h:146
static void Emit(MCObjectStreamer *MCOS, MCDwarfLineTableParams Params)
Definition: MCDwarf.cpp:233
static const MCExpr * MakeStartMinusEndExpr(const MCStreamer &MCOS, const MCSymbol &Start, const MCSymbol &End, int IntVal)
Definition: MCDwarf.cpp:116
pointer data()
Return a pointer to the vector&#39;s buffer, even if empty().
Definition: SmallVector.h:143
static void EmitPersonality(MCStreamer &streamer, const MCSymbol &symbol, unsigned symbolEncoding)
Definition: MCDwarf.cpp:1175
StringRef filename(StringRef path, Style style=Style::native)
Get filename.
Definition: Path.cpp:576
static void Make(MCSymbol *Symbol, MCStreamer *MCOS, SourceMgr &SrcMgr, SMLoc &Loc)
Definition: MCDwarf.cpp:1093
const MCSymbol * Personality
Definition: MCDwarf.h:519
#define I(x, y, z)
Definition: MD5.cpp:58
static const MCExpr * makeStartPlusIntExpr(MCContext &Ctx, const MCSymbol &Start, int IntVal)
Definition: MCDwarf.cpp:138
unsigned getCalleeSaveStackSlotSize() const
Get the callee-saved register stack slot size in bytes.
Definition: MCAsmInfo.h:387
bool isLittleEndian() const
True if the target is little endian.
Definition: MCAsmInfo.h:392
Manage the .debug_line_str section contents, if we use it.
Definition: MCDwarf.cpp:50
constexpr bool isUInt< 16 >(uint64_t x)
Definition: MathExtras.h:338
void emitFill(uint64_t NumBytes, uint8_t FillValue)
Emit NumBytes bytes worth of the value specified by FillValue.
Definition: MCStreamer.cpp:182
MD5::MD5Result * Checksum
The MD5 checksum, if there is one.
Definition: MCDwarf.h:58
unsigned getRARegister() const
This method should return the register where the return address can be found.
MCSymbol * endSection(MCSection *Section)
Definition: MCStreamer.cpp:973
unsigned DirIndex
Definition: MCDwarf.h:54
StringRef getName() const
getName - Get the symbol name.
Definition: MCSymbol.h:203
unsigned getCodePointerSize() const
Get the code pointer size in bytes.
Definition: MCAsmInfo.h:383
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
void emitRef(MCStreamer *MCOS, StringRef Path)
Emit a reference to the string.
Definition: MCDwarf.cpp:319
std::array< uint8_t, 16 > Bytes
Definition: MD5.h:56
const MCRegisterInfo * getRegisterInfo() const
Definition: MCContext.h:290
LLVM Value Representation.
Definition: Value.h:73
Generic interface to target specific assembler backends.
Definition: MCAsmBackend.h:40
ArrayRef< MCDwarfFrameInfo > getDwarfFrameInfos() const
Definition: MCStreamer.h:253
constexpr char Size[]
Key for Kernel::Arg::Metadata::mSize.
virtual void EmitLabel(MCSymbol *Symbol, SMLoc Loc=SMLoc())
Emit a label for Symbol into the current section.
Definition: MCStreamer.cpp:309
static void emitEncodingByte(MCObjectStreamer &Streamer, unsigned Encoding)
Definition: MCDwarf.cpp:1211
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
Subtraction.
Definition: MCExpr.h:431
void emitSection(MCStreamer *MCOS)
Emit the .debug_line_str section if appropriate.
Definition: MCDwarf.cpp:307
static void Emit(MCObjectStreamer &streamer, MCAsmBackend *MAB, bool isEH)
Definition: MCDwarf.cpp:1679
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
Instances of this class represent the name of the dwarf .file directive and its associated dwarf file...
Definition: MCDwarf.h:48
MCSection * getDwarfRangesSection() const
void EmitULEB128IntValue(uint64_t Value)
Special case of EmitULEB128Value that avoids the client having to pass in a MCExpr for constant integ...
Definition: MCStreamer.cpp:125
Represents a location in source code.
Definition: SMLoc.h:24
bool isUIntN(unsigned N, uint64_t x)
Checks if an unsigned integer fits into the given (dynamic) bit width.
Definition: MathExtras.h:385
static const MCConstantExpr * create(int64_t Value, MCContext &Ctx)
Definition: MCExpr.cpp:159
virtual const MCExpr * getExprForFDESymbol(const MCSymbol *Sym, unsigned Encoding, MCStreamer &Streamer) const
Definition: MCAsmInfo.cpp:75
std::pair< MCSymbol *, MCSymbol * > Emit(MCStreamer *MCOS, MCDwarfLineTableParams Params, Optional< MCDwarfLineStr > &LineStr) const
Definition: MCDwarf.cpp:267
void resize(size_type N)
Definition: SmallVector.h:353