LLVM  10.0.0svn
MipsELFObjectWriter.cpp
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1 //===-- MipsELFObjectWriter.cpp - Mips ELF Writer -------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
11 #include "llvm/ADT/STLExtras.h"
12 #include "llvm/BinaryFormat/ELF.h"
13 #include "llvm/MC/MCContext.h"
15 #include "llvm/MC/MCFixup.h"
16 #include "llvm/MC/MCObjectWriter.h"
17 #include "llvm/MC/MCSymbolELF.h"
18 #include "llvm/Support/Casting.h"
19 #include "llvm/Support/Compiler.h"
20 #include "llvm/Support/Debug.h"
24 #include <algorithm>
25 #include <cassert>
26 #include <cstdint>
27 #include <iterator>
28 #include <list>
29 #include <utility>
30 
31 #define DEBUG_TYPE "mips-elf-object-writer"
32 
33 using namespace llvm;
34 
35 namespace {
36 
37 /// Holds additional information needed by the relocation ordering algorithm.
38 struct MipsRelocationEntry {
39  const ELFRelocationEntry R; ///< The relocation.
40  bool Matched = false; ///< Is this relocation part of a match.
41 
42  MipsRelocationEntry(const ELFRelocationEntry &R) : R(R) {}
43 
44  void print(raw_ostream &Out) const {
45  R.print(Out);
46  Out << ", Matched=" << Matched;
47  }
48 };
49 
50 #ifndef NDEBUG
51 raw_ostream &operator<<(raw_ostream &OS, const MipsRelocationEntry &RHS) {
52  RHS.print(OS);
53  return OS;
54 }
55 #endif
56 
57 class MipsELFObjectWriter : public MCELFObjectTargetWriter {
58 public:
59  MipsELFObjectWriter(uint8_t OSABI, bool HasRelocationAddend, bool Is64);
60 
61  ~MipsELFObjectWriter() override = default;
62 
63  unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
64  const MCFixup &Fixup, bool IsPCRel) const override;
65  bool needsRelocateWithSymbol(const MCSymbol &Sym,
66  unsigned Type) const override;
67  void sortRelocs(const MCAssembler &Asm,
68  std::vector<ELFRelocationEntry> &Relocs) override;
69 };
70 
71 /// The possible results of the Predicate function used by find_best.
73  FindBest_NoMatch = 0, ///< The current element is not a match.
74  FindBest_Match, ///< The current element is a match but better ones are
75  /// possible.
76  FindBest_PerfectMatch, ///< The current element is an unbeatable match.
77 };
78 
79 } // end anonymous namespace
80 
81 /// Copy elements in the range [First, Last) to d1 when the predicate is true or
82 /// d2 when the predicate is false. This is essentially both std::copy_if and
83 /// std::remove_copy_if combined into a single pass.
84 template <class InputIt, class OutputIt1, class OutputIt2, class UnaryPredicate>
85 static std::pair<OutputIt1, OutputIt2> copy_if_else(InputIt First, InputIt Last,
86  OutputIt1 d1, OutputIt2 d2,
87  UnaryPredicate Predicate) {
88  for (InputIt I = First; I != Last; ++I) {
89  if (Predicate(*I)) {
90  *d1 = *I;
91  d1++;
92  } else {
93  *d2 = *I;
94  d2++;
95  }
96  }
97 
98  return std::make_pair(d1, d2);
99 }
100 
101 /// Find the best match in the range [First, Last).
102 ///
103 /// An element matches when Predicate(X) returns FindBest_Match or
104 /// FindBest_PerfectMatch. A value of FindBest_PerfectMatch also terminates
105 /// the search. BetterThan(A, B) is a comparator that returns true when A is a
106 /// better match than B. The return value is the position of the best match.
107 ///
108 /// This is similar to std::find_if but finds the best of multiple possible
109 /// matches.
110 template <class InputIt, class UnaryPredicate, class Comparator>
111 static InputIt find_best(InputIt First, InputIt Last, UnaryPredicate Predicate,
112  Comparator BetterThan) {
113  InputIt Best = Last;
114 
115  for (InputIt I = First; I != Last; ++I) {
116  unsigned Matched = Predicate(*I);
117  if (Matched != FindBest_NoMatch) {
118  LLVM_DEBUG(dbgs() << std::distance(First, I) << " is a match (";
119  I->print(dbgs()); dbgs() << ")\n");
120  if (Best == Last || BetterThan(*I, *Best)) {
121  LLVM_DEBUG(dbgs() << ".. and it beats the last one\n");
122  Best = I;
123  }
124  }
125  if (Matched == FindBest_PerfectMatch) {
126  LLVM_DEBUG(dbgs() << ".. and it is unbeatable\n");
127  break;
128  }
129  }
130 
131  return Best;
132 }
133 
134 /// Determine the low relocation that matches the given relocation.
135 /// If the relocation does not need a low relocation then the return value
136 /// is ELF::R_MIPS_NONE.
137 ///
138 /// The relocations that need a matching low part are
139 /// R_(MIPS|MICROMIPS|MIPS16)_HI16 for all symbols and
140 /// R_(MIPS|MICROMIPS|MIPS16)_GOT16 for local symbols only.
141 static unsigned getMatchingLoType(const ELFRelocationEntry &Reloc) {
142  unsigned Type = Reloc.Type;
143  if (Type == ELF::R_MIPS_HI16)
144  return ELF::R_MIPS_LO16;
145  if (Type == ELF::R_MICROMIPS_HI16)
146  return ELF::R_MICROMIPS_LO16;
147  if (Type == ELF::R_MIPS16_HI16)
148  return ELF::R_MIPS16_LO16;
149 
150  if (Reloc.OriginalSymbol &&
152  return ELF::R_MIPS_NONE;
153 
154  if (Type == ELF::R_MIPS_GOT16)
155  return ELF::R_MIPS_LO16;
156  if (Type == ELF::R_MICROMIPS_GOT16)
157  return ELF::R_MICROMIPS_LO16;
158  if (Type == ELF::R_MIPS16_GOT16)
159  return ELF::R_MIPS16_LO16;
160 
161  return ELF::R_MIPS_NONE;
162 }
163 
164 /// Determine whether a relocation (X) matches the one given in R.
165 ///
166 /// A relocation matches if:
167 /// - It's type matches that of a corresponding low part. This is provided in
168 /// MatchingType for efficiency.
169 /// - It's based on the same symbol.
170 /// - It's offset of greater or equal to that of the one given in R.
171 /// It should be noted that this rule assumes the programmer does not use
172 /// offsets that exceed the alignment of the symbol. The carry-bit will be
173 /// incorrect if this is not true.
174 ///
175 /// A matching relocation is unbeatable if:
176 /// - It is not already involved in a match.
177 /// - It's offset is exactly that of the one given in R.
178 static FindBestPredicateResult isMatchingReloc(const MipsRelocationEntry &X,
179  const ELFRelocationEntry &R,
180  unsigned MatchingType) {
181  if (X.R.Type == MatchingType && X.R.OriginalSymbol == R.OriginalSymbol) {
182  if (!X.Matched &&
183  X.R.OriginalAddend == R.OriginalAddend)
184  return FindBest_PerfectMatch;
185  else if (X.R.OriginalAddend >= R.OriginalAddend)
186  return FindBest_Match;
187  }
188  return FindBest_NoMatch;
189 }
190 
191 /// Determine whether Candidate or PreviousBest is the better match.
192 /// The return value is true if Candidate is the better match.
193 ///
194 /// A matching relocation is a better match if:
195 /// - It has a smaller addend.
196 /// - It is not already involved in a match.
197 static bool compareMatchingRelocs(const MipsRelocationEntry &Candidate,
198  const MipsRelocationEntry &PreviousBest) {
199  if (Candidate.R.OriginalAddend != PreviousBest.R.OriginalAddend)
200  return Candidate.R.OriginalAddend < PreviousBest.R.OriginalAddend;
201  return PreviousBest.Matched && !Candidate.Matched;
202 }
203 
204 #ifndef NDEBUG
205 /// Print all the relocations.
206 template <class Container>
207 static void dumpRelocs(const char *Prefix, const Container &Relocs) {
208  for (const auto &R : Relocs)
209  dbgs() << Prefix << R << "\n";
210 }
211 #endif
212 
213 MipsELFObjectWriter::MipsELFObjectWriter(uint8_t OSABI,
214  bool HasRelocationAddend, bool Is64)
215  : MCELFObjectTargetWriter(Is64, OSABI, ELF::EM_MIPS, HasRelocationAddend) {}
216 
218  const MCValue &Target,
219  const MCFixup &Fixup,
220  bool IsPCRel) const {
221  // Determine the type of the relocation.
222  unsigned Kind = Fixup.getTargetKind();
223 
224  switch (Kind) {
225  case FK_NONE:
226  return ELF::R_MIPS_NONE;
227  case FK_Data_1:
228  Ctx.reportError(Fixup.getLoc(),
229  "MIPS does not support one byte relocations");
230  return ELF::R_MIPS_NONE;
231  case Mips::fixup_Mips_16:
232  case FK_Data_2:
233  return IsPCRel ? ELF::R_MIPS_PC16 : ELF::R_MIPS_16;
234  case Mips::fixup_Mips_32:
235  case FK_Data_4:
236  return IsPCRel ? ELF::R_MIPS_PC32 : ELF::R_MIPS_32;
237  }
238 
239  if (IsPCRel) {
240  switch (Kind) {
241  case FK_Data_8:
242  Ctx.reportError(Fixup.getLoc(),
243  "MIPS does not support 64-bit PC-relative relocations");
244  return ELF::R_MIPS_NONE;
247  return ELF::R_MIPS_PC16;
249  return ELF::R_MICROMIPS_PC7_S1;
251  return ELF::R_MICROMIPS_PC10_S1;
253  return ELF::R_MICROMIPS_PC16_S1;
255  return ELF::R_MICROMIPS_PC26_S1;
257  return ELF::R_MICROMIPS_PC19_S2;
259  return ELF::R_MICROMIPS_PC18_S3;
261  return ELF::R_MICROMIPS_PC21_S1;
263  return ELF::R_MIPS_PC19_S2;
265  return ELF::R_MIPS_PC18_S3;
267  return ELF::R_MIPS_PC21_S2;
269  return ELF::R_MIPS_PC26_S2;
271  return ELF::R_MIPS_PCHI16;
273  return ELF::R_MIPS_PCLO16;
274  }
275 
276  llvm_unreachable("invalid PC-relative fixup kind!");
277  }
278 
279  switch (Kind) {
280  case Mips::fixup_Mips_64:
281  case FK_Data_8:
282  return ELF::R_MIPS_64;
283  case FK_DTPRel_4:
284  return ELF::R_MIPS_TLS_DTPREL32;
285  case FK_DTPRel_8:
286  return ELF::R_MIPS_TLS_DTPREL64;
287  case FK_TPRel_4:
288  return ELF::R_MIPS_TLS_TPREL32;
289  case FK_TPRel_8:
290  return ELF::R_MIPS_TLS_TPREL64;
291  case FK_GPRel_4:
292  if (is64Bit()) {
293  unsigned Type = (unsigned)ELF::R_MIPS_NONE;
294  Type = setRType((unsigned)ELF::R_MIPS_GPREL32, Type);
295  Type = setRType2((unsigned)ELF::R_MIPS_64, Type);
296  Type = setRType3((unsigned)ELF::R_MIPS_NONE, Type);
297  return Type;
298  }
299  return ELF::R_MIPS_GPREL32;
301  return ELF::R_MIPS_GPREL16;
302  case Mips::fixup_Mips_26:
303  return ELF::R_MIPS_26;
305  return ELF::R_MIPS_CALL16;
307  return ELF::R_MIPS_GOT16;
309  return ELF::R_MIPS_HI16;
311  return ELF::R_MIPS_LO16;
313  return ELF::R_MIPS_TLS_GD;
315  return ELF::R_MIPS_TLS_GOTTPREL;
317  return ELF::R_MIPS_TLS_TPREL_HI16;
319  return ELF::R_MIPS_TLS_TPREL_LO16;
321  return ELF::R_MIPS_TLS_LDM;
323  return ELF::R_MIPS_TLS_DTPREL_HI16;
325  return ELF::R_MIPS_TLS_DTPREL_LO16;
327  return ELF::R_MIPS_GOT_PAGE;
329  return ELF::R_MIPS_GOT_OFST;
331  return ELF::R_MIPS_GOT_DISP;
333  unsigned Type = (unsigned)ELF::R_MIPS_NONE;
334  Type = setRType((unsigned)ELF::R_MIPS_GPREL16, Type);
335  Type = setRType2((unsigned)ELF::R_MIPS_SUB, Type);
336  Type = setRType3((unsigned)ELF::R_MIPS_HI16, Type);
337  return Type;
338  }
340  unsigned Type = (unsigned)ELF::R_MIPS_NONE;
341  Type = setRType((unsigned)ELF::R_MICROMIPS_GPREL16, Type);
342  Type = setRType2((unsigned)ELF::R_MICROMIPS_SUB, Type);
343  Type = setRType3((unsigned)ELF::R_MICROMIPS_HI16, Type);
344  return Type;
345  }
347  unsigned Type = (unsigned)ELF::R_MIPS_NONE;
348  Type = setRType((unsigned)ELF::R_MIPS_GPREL16, Type);
349  Type = setRType2((unsigned)ELF::R_MIPS_SUB, Type);
350  Type = setRType3((unsigned)ELF::R_MIPS_LO16, Type);
351  return Type;
352  }
354  unsigned Type = (unsigned)ELF::R_MIPS_NONE;
355  Type = setRType((unsigned)ELF::R_MICROMIPS_GPREL16, Type);
356  Type = setRType2((unsigned)ELF::R_MICROMIPS_SUB, Type);
357  Type = setRType3((unsigned)ELF::R_MICROMIPS_LO16, Type);
358  return Type;
359  }
361  return ELF::R_MIPS_HIGHER;
363  return ELF::R_MIPS_HIGHEST;
365  return ELF::R_MIPS_SUB;
367  return ELF::R_MIPS_GOT_HI16;
369  return ELF::R_MIPS_GOT_LO16;
371  return ELF::R_MIPS_CALL_HI16;
373  return ELF::R_MIPS_CALL_LO16;
375  return ELF::R_MICROMIPS_26_S1;
377  return ELF::R_MICROMIPS_HI16;
379  return ELF::R_MICROMIPS_LO16;
381  return ELF::R_MICROMIPS_GOT16;
383  return ELF::R_MICROMIPS_CALL16;
385  return ELF::R_MICROMIPS_GOT_DISP;
387  return ELF::R_MICROMIPS_GOT_PAGE;
389  return ELF::R_MICROMIPS_GOT_OFST;
391  return ELF::R_MICROMIPS_TLS_GD;
393  return ELF::R_MICROMIPS_TLS_LDM;
395  return ELF::R_MICROMIPS_TLS_DTPREL_HI16;
397  return ELF::R_MICROMIPS_TLS_DTPREL_LO16;
399  return ELF::R_MICROMIPS_TLS_GOTTPREL;
401  return ELF::R_MICROMIPS_TLS_TPREL_HI16;
403  return ELF::R_MICROMIPS_TLS_TPREL_LO16;
405  return ELF::R_MICROMIPS_SUB;
407  return ELF::R_MICROMIPS_HIGHER;
409  return ELF::R_MICROMIPS_HIGHEST;
411  return ELF::R_MIPS_JALR;
413  return ELF::R_MICROMIPS_JALR;
414  }
415 
416  llvm_unreachable("invalid fixup kind!");
417 }
418 
419 /// Sort relocation table entries by offset except where another order is
420 /// required by the MIPS ABI.
421 ///
422 /// MIPS has a few relocations that have an AHL component in the expression used
423 /// to evaluate them. This AHL component is an addend with the same number of
424 /// bits as a symbol value but not all of our ABI's are able to supply a
425 /// sufficiently sized addend in a single relocation.
426 ///
427 /// The O32 ABI for example, uses REL relocations which store the addend in the
428 /// section data. All the relocations with AHL components affect 16-bit fields
429 /// so the addend for a single relocation is limited to 16-bit. This ABI
430 /// resolves the limitation by linking relocations (e.g. R_MIPS_HI16 and
431 /// R_MIPS_LO16) and distributing the addend between the linked relocations. The
432 /// ABI mandates that such relocations must be next to each other in a
433 /// particular order (e.g. R_MIPS_HI16 must be immediately followed by a
434 /// matching R_MIPS_LO16) but the rule is less strict in practice.
435 ///
436 /// The de facto standard is lenient in the following ways:
437 /// - 'Immediately following' does not refer to the next relocation entry but
438 /// the next matching relocation.
439 /// - There may be multiple high parts relocations for one low part relocation.
440 /// - There may be multiple low part relocations for one high part relocation.
441 /// - The AHL addend in each part does not have to be exactly equal as long as
442 /// the difference does not affect the carry bit from bit 15 into 16. This is
443 /// to allow, for example, the use of %lo(foo) and %lo(foo+4) when loading
444 /// both halves of a long long.
445 ///
446 /// See getMatchingLoType() for a description of which high part relocations
447 /// match which low part relocations. One particular thing to note is that
448 /// R_MIPS_GOT16 and similar only have AHL addends if they refer to local
449 /// symbols.
450 ///
451 /// It should also be noted that this function is not affected by whether
452 /// the symbol was kept or rewritten into a section-relative equivalent. We
453 /// always match using the expressions from the source.
454 void MipsELFObjectWriter::sortRelocs(const MCAssembler &Asm,
455  std::vector<ELFRelocationEntry> &Relocs) {
456  // We do not need to sort the relocation table for RELA relocations which
457  // N32/N64 uses as the relocation addend contains the value we require,
458  // rather than it being split across a pair of relocations.
459  if (hasRelocationAddend())
460  return;
461 
462  if (Relocs.size() < 2)
463  return;
464 
465  // Sort relocations by the address they are applied to.
466  llvm::sort(Relocs,
467  [](const ELFRelocationEntry &A, const ELFRelocationEntry &B) {
468  return A.Offset < B.Offset;
469  });
470 
471  std::list<MipsRelocationEntry> Sorted;
472  std::list<ELFRelocationEntry> Remainder;
473 
474  LLVM_DEBUG(dumpRelocs("R: ", Relocs));
475 
476  // Separate the movable relocations (AHL relocations using the high bits) from
477  // the immobile relocations (everything else). This does not preserve high/low
478  // matches that already existed in the input.
479  copy_if_else(Relocs.begin(), Relocs.end(), std::back_inserter(Remainder),
480  std::back_inserter(Sorted), [](const ELFRelocationEntry &Reloc) {
481  return getMatchingLoType(Reloc) != ELF::R_MIPS_NONE;
482  });
483 
484  for (auto &R : Remainder) {
485  LLVM_DEBUG(dbgs() << "Matching: " << R << "\n");
486 
487  unsigned MatchingType = getMatchingLoType(R);
488  assert(MatchingType != ELF::R_MIPS_NONE &&
489  "Wrong list for reloc that doesn't need a match");
490 
491  // Find the best matching relocation for the current high part.
492  // See isMatchingReloc for a description of a matching relocation and
493  // compareMatchingRelocs for a description of what 'best' means.
494  auto InsertionPoint =
495  find_best(Sorted.begin(), Sorted.end(),
496  [&R, &MatchingType](const MipsRelocationEntry &X) {
497  return isMatchingReloc(X, R, MatchingType);
498  },
500 
501  // If we matched then insert the high part in front of the match and mark
502  // both relocations as being involved in a match. We only mark the high
503  // part for cosmetic reasons in the debug output.
504  //
505  // If we failed to find a match then the high part is orphaned. This is not
506  // permitted since the relocation cannot be evaluated without knowing the
507  // carry-in. We can sometimes handle this using a matching low part that is
508  // already used in a match but we already cover that case in
509  // isMatchingReloc and compareMatchingRelocs. For the remaining cases we
510  // should insert the high part at the end of the list. This will cause the
511  // linker to fail but the alternative is to cause the linker to bind the
512  // high part to a semi-matching low part and silently calculate the wrong
513  // value. Unfortunately we have no means to warn the user that we did this
514  // so leave it up to the linker to complain about it.
515  if (InsertionPoint != Sorted.end())
516  InsertionPoint->Matched = true;
517  Sorted.insert(InsertionPoint, R)->Matched = true;
518  }
519 
520  LLVM_DEBUG(dumpRelocs("S: ", Sorted));
521 
522  assert(Relocs.size() == Sorted.size() && "Some relocs were not consumed");
523 
524  // Overwrite the original vector with the sorted elements. The caller expects
525  // them in reverse order.
526  unsigned CopyTo = 0;
527  for (const auto &R : reverse(Sorted))
528  Relocs[CopyTo++] = R.R;
529 }
530 
531 bool MipsELFObjectWriter::needsRelocateWithSymbol(const MCSymbol &Sym,
532  unsigned Type) const {
533  // If it's a compound relocation for N64 then we need the relocation if any
534  // sub-relocation needs it.
535  if (!isUInt<8>(Type))
536  return needsRelocateWithSymbol(Sym, Type & 0xff) ||
537  needsRelocateWithSymbol(Sym, (Type >> 8) & 0xff) ||
538  needsRelocateWithSymbol(Sym, (Type >> 16) & 0xff);
539 
540  switch (Type) {
541  default:
542  errs() << Type << "\n";
543  llvm_unreachable("Unexpected relocation");
544  return true;
545 
546  // This relocation doesn't affect the section data.
547  case ELF::R_MIPS_NONE:
548  return false;
549 
550  // On REL ABI's (e.g. O32), these relocations form pairs. The pairing is done
551  // by the static linker by matching the symbol and offset.
552  // We only see one relocation at a time but it's still safe to relocate with
553  // the section so long as both relocations make the same decision.
554  //
555  // Some older linkers may require the symbol for particular cases. Such cases
556  // are not supported yet but can be added as required.
557  case ELF::R_MIPS_GOT16:
558  case ELF::R_MIPS16_GOT16:
559  case ELF::R_MICROMIPS_GOT16:
560  case ELF::R_MIPS_HIGHER:
561  case ELF::R_MIPS_HIGHEST:
562  case ELF::R_MIPS_HI16:
563  case ELF::R_MIPS16_HI16:
564  case ELF::R_MICROMIPS_HI16:
565  case ELF::R_MIPS_LO16:
566  case ELF::R_MIPS16_LO16:
567  case ELF::R_MICROMIPS_LO16:
568  // FIXME: It should be safe to return false for the STO_MIPS_MICROMIPS but
569  // we neglect to handle the adjustment to the LSB of the addend that
570  // it causes in applyFixup() and similar.
571  if (cast<MCSymbolELF>(Sym).getOther() & ELF::STO_MIPS_MICROMIPS)
572  return true;
573  return false;
574 
575  case ELF::R_MIPS_GOT_PAGE:
576  case ELF::R_MICROMIPS_GOT_PAGE:
577  case ELF::R_MIPS_GOT_OFST:
578  case ELF::R_MICROMIPS_GOT_OFST:
579  case ELF::R_MIPS_16:
580  case ELF::R_MIPS_32:
581  case ELF::R_MIPS_GPREL32:
582  if (cast<MCSymbolELF>(Sym).getOther() & ELF::STO_MIPS_MICROMIPS)
583  return true;
585  case ELF::R_MIPS_26:
586  case ELF::R_MIPS_64:
587  case ELF::R_MIPS_GPREL16:
588  case ELF::R_MIPS_PC16:
589  case ELF::R_MIPS_SUB:
590  return false;
591 
592  // FIXME: Many of these relocations should probably return false but this
593  // hasn't been confirmed to be safe yet.
594  case ELF::R_MIPS_REL32:
595  case ELF::R_MIPS_LITERAL:
596  case ELF::R_MIPS_CALL16:
597  case ELF::R_MIPS_SHIFT5:
598  case ELF::R_MIPS_SHIFT6:
599  case ELF::R_MIPS_GOT_DISP:
600  case ELF::R_MIPS_GOT_HI16:
601  case ELF::R_MIPS_GOT_LO16:
602  case ELF::R_MIPS_INSERT_A:
603  case ELF::R_MIPS_INSERT_B:
604  case ELF::R_MIPS_DELETE:
605  case ELF::R_MIPS_CALL_HI16:
606  case ELF::R_MIPS_CALL_LO16:
607  case ELF::R_MIPS_SCN_DISP:
608  case ELF::R_MIPS_REL16:
609  case ELF::R_MIPS_ADD_IMMEDIATE:
610  case ELF::R_MIPS_PJUMP:
611  case ELF::R_MIPS_RELGOT:
612  case ELF::R_MIPS_JALR:
613  case ELF::R_MIPS_TLS_DTPMOD32:
614  case ELF::R_MIPS_TLS_DTPREL32:
615  case ELF::R_MIPS_TLS_DTPMOD64:
616  case ELF::R_MIPS_TLS_DTPREL64:
617  case ELF::R_MIPS_TLS_GD:
618  case ELF::R_MIPS_TLS_LDM:
619  case ELF::R_MIPS_TLS_DTPREL_HI16:
620  case ELF::R_MIPS_TLS_DTPREL_LO16:
621  case ELF::R_MIPS_TLS_GOTTPREL:
622  case ELF::R_MIPS_TLS_TPREL32:
623  case ELF::R_MIPS_TLS_TPREL64:
624  case ELF::R_MIPS_TLS_TPREL_HI16:
625  case ELF::R_MIPS_TLS_TPREL_LO16:
626  case ELF::R_MIPS_GLOB_DAT:
627  case ELF::R_MIPS_PC21_S2:
628  case ELF::R_MIPS_PC26_S2:
629  case ELF::R_MIPS_PC18_S3:
630  case ELF::R_MIPS_PC19_S2:
631  case ELF::R_MIPS_PCHI16:
632  case ELF::R_MIPS_PCLO16:
633  case ELF::R_MIPS_COPY:
634  case ELF::R_MIPS_JUMP_SLOT:
635  case ELF::R_MIPS_NUM:
636  case ELF::R_MIPS_PC32:
637  case ELF::R_MIPS_EH:
638  case ELF::R_MICROMIPS_26_S1:
639  case ELF::R_MICROMIPS_GPREL16:
640  case ELF::R_MICROMIPS_LITERAL:
641  case ELF::R_MICROMIPS_PC7_S1:
642  case ELF::R_MICROMIPS_PC10_S1:
643  case ELF::R_MICROMIPS_PC16_S1:
644  case ELF::R_MICROMIPS_CALL16:
645  case ELF::R_MICROMIPS_GOT_DISP:
646  case ELF::R_MICROMIPS_GOT_HI16:
647  case ELF::R_MICROMIPS_GOT_LO16:
648  case ELF::R_MICROMIPS_SUB:
649  case ELF::R_MICROMIPS_HIGHER:
650  case ELF::R_MICROMIPS_HIGHEST:
651  case ELF::R_MICROMIPS_CALL_HI16:
652  case ELF::R_MICROMIPS_CALL_LO16:
653  case ELF::R_MICROMIPS_SCN_DISP:
654  case ELF::R_MICROMIPS_JALR:
655  case ELF::R_MICROMIPS_HI0_LO16:
656  case ELF::R_MICROMIPS_TLS_GD:
657  case ELF::R_MICROMIPS_TLS_LDM:
658  case ELF::R_MICROMIPS_TLS_DTPREL_HI16:
659  case ELF::R_MICROMIPS_TLS_DTPREL_LO16:
660  case ELF::R_MICROMIPS_TLS_GOTTPREL:
661  case ELF::R_MICROMIPS_TLS_TPREL_HI16:
662  case ELF::R_MICROMIPS_TLS_TPREL_LO16:
663  case ELF::R_MICROMIPS_GPREL7_S2:
664  case ELF::R_MICROMIPS_PC23_S2:
665  case ELF::R_MICROMIPS_PC21_S1:
666  case ELF::R_MICROMIPS_PC26_S1:
667  case ELF::R_MICROMIPS_PC18_S3:
668  case ELF::R_MICROMIPS_PC19_S2:
669  return true;
670 
671  // FIXME: Many of these should probably return false but MIPS16 isn't
672  // supported by the integrated assembler.
673  case ELF::R_MIPS16_26:
674  case ELF::R_MIPS16_GPREL:
675  case ELF::R_MIPS16_CALL16:
676  case ELF::R_MIPS16_TLS_GD:
677  case ELF::R_MIPS16_TLS_LDM:
678  case ELF::R_MIPS16_TLS_DTPREL_HI16:
679  case ELF::R_MIPS16_TLS_DTPREL_LO16:
680  case ELF::R_MIPS16_TLS_GOTTPREL:
681  case ELF::R_MIPS16_TLS_TPREL_HI16:
682  case ELF::R_MIPS16_TLS_TPREL_LO16:
683  llvm_unreachable("Unsupported MIPS16 relocation");
684  return true;
685  }
686 }
687 
688 std::unique_ptr<MCObjectTargetWriter>
690  uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TT.getOS());
691  bool IsN64 = TT.isArch64Bit() && !IsN32;
692  bool HasRelocationAddend = TT.isArch64Bit();
693  return std::make_unique<MipsELFObjectWriter>(OSABI, HasRelocationAddend,
694  IsN64);
695 }
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
raw_ostream & errs()
This returns a reference to a raw_ostream for standard error.
A eight-byte dtp relative fixup.
Definition: MCFixup.h:38
This class represents lattice values for constants.
Definition: AllocatorList.h:23
This represents an "assembler immediate".
Definition: MCValue.h:39
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
OSType getOS() const
getOS - Get the parsed operating system type of this triple.
Definition: Triple.h:305
std::unique_ptr< MCObjectTargetWriter > createMipsELFObjectWriter(const Triple &TT, bool IsN32)
unsigned getBinding() const
Definition: MCSymbolELF.cpp:66
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:77
A four-byte tp relative fixup.
Definition: MCFixup.h:39
static unsigned getRelocType(const MCValue &Target, const MCFixupKind FixupKind, const bool IsPCRel)
Translates generic PPC fixup kind to Mach-O/PPC relocation type enum.
A four-byte fixup.
Definition: MCFixup.h:26
Context object for machine code objects.
Definition: MCContext.h:65
auto reverse(ContainerTy &&C, typename std::enable_if< has_rbegin< ContainerTy >::value >::type *=nullptr) -> decltype(make_range(C.rbegin(), C.rend()))
Definition: STLExtras.h:261
A four-byte gp relative fixup.
Definition: MCFixup.h:35
static std::pair< OutputIt1, OutputIt2 > copy_if_else(InputIt First, InputIt Last, OutputIt1 d1, OutputIt2 d2, UnaryPredicate Predicate)
Copy elements in the range [First, Last) to d1 when the predicate is true or d2 when the predicate is...
static FindBestPredicateResult isMatchingReloc(const MipsRelocationEntry &X, const ELFRelocationEntry &R, unsigned MatchingType)
Determine whether a relocation (X) matches the one given in R.
static InputIt find_best(InputIt First, InputIt Last, UnaryPredicate Predicate, Comparator BetterThan)
Find the best match in the range [First, Last).
A four-byte dtp relative fixup.
Definition: MCFixup.h:37
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
constexpr bool isUInt< 8 >(uint64_t x)
Definition: MathExtras.h:379
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
static void dumpRelocs(const char *Prefix, const Container &Relocs)
Print all the relocations.
static bool is64Bit(const char *name)
static bool compareMatchingRelocs(const MipsRelocationEntry &Candidate, const MipsRelocationEntry &PreviousBest)
Determine whether Candidate or PreviousBest is the better match.
void reportError(SMLoc L, const Twine &Msg)
Definition: MCContext.cpp:687
static void print(raw_ostream &Out, object::Archive::Kind Kind, T Val)
A eight-byte tp relative fixup.
Definition: MCFixup.h:40
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
A one-byte fixup.
Definition: MCFixup.h:24
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:43
void sort(IteratorTy Start, IteratorTy End)
Definition: STLExtras.h:1095
PowerPC TLS Dynamic Call Fixup
SMLoc getLoc() const
Definition: MCFixup.h:197
A no-op fixup.
Definition: MCFixup.h:23
FindBestPredicateResult
The possible results of the Predicate function used by find_best.
Predicate
Predicate - These are "(BI << 5) | BO" for various predicates.
Definition: PPCPredicates.h:26
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
Target - Wrapper for Target specific information.
bool isArch64Bit() const
Test whether the architecture is 64-bit.
Definition: Triple.cpp:1292
void print(raw_ostream &Out) const
#define I(x, y, z)
Definition: MD5.cpp:58
A eight-byte fixup.
Definition: MCFixup.h:27
raw_ostream & operator<<(raw_ostream &OS, const APInt &I)
Definition: APInt.h:2047
const MCSymbolELF * OriginalSymbol
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
unsigned getTargetKind() const
Definition: MCFixup.h:128
#define LLVM_FALLTHROUGH
LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements.
Definition: Compiler.h:273
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:45
static unsigned getMatchingLoType(const ELFRelocationEntry &Reloc)
Determine the low relocation that matches the given relocation.
#define LLVM_DEBUG(X)
Definition: Debug.h:122
A two-byte fixup.
Definition: MCFixup.h:25