LLVM  6.0.0svn
MipsELFObjectWriter.cpp
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1 //===-- MipsELFObjectWriter.cpp - Mips ELF Writer -------------------------===//
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 
12 #include "llvm/ADT/STLExtras.h"
13 #include "llvm/BinaryFormat/ELF.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  bool IsLittleEndian);
61 
62  ~MipsELFObjectWriter() override = default;
63 
64  unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
65  const MCFixup &Fixup, bool IsPCRel) const override;
66  bool needsRelocateWithSymbol(const MCSymbol &Sym,
67  unsigned Type) const override;
68  void sortRelocs(const MCAssembler &Asm,
69  std::vector<ELFRelocationEntry> &Relocs) override;
70 };
71 
72 /// The possible results of the Predicate function used by find_best.
74  FindBest_NoMatch = 0, ///< The current element is not a match.
75  FindBest_Match, ///< The current element is a match but better ones are
76  /// possible.
77  FindBest_PerfectMatch, ///< The current element is an unbeatable match.
78 };
79 
80 } // end anonymous namespace
81 
82 /// Copy elements in the range [First, Last) to d1 when the predicate is true or
83 /// d2 when the predicate is false. This is essentially both std::copy_if and
84 /// std::remove_copy_if combined into a single pass.
85 template <class InputIt, class OutputIt1, class OutputIt2, class UnaryPredicate>
86 static std::pair<OutputIt1, OutputIt2> copy_if_else(InputIt First, InputIt Last,
87  OutputIt1 d1, OutputIt2 d2,
88  UnaryPredicate Predicate) {
89  for (InputIt I = First; I != Last; ++I) {
90  if (Predicate(*I)) {
91  *d1 = *I;
92  d1++;
93  } else {
94  *d2 = *I;
95  d2++;
96  }
97  }
98 
99  return std::make_pair(d1, d2);
100 }
101 
102 /// Find the best match in the range [First, Last).
103 ///
104 /// An element matches when Predicate(X) returns FindBest_Match or
105 /// FindBest_PerfectMatch. A value of FindBest_PerfectMatch also terminates
106 /// the search. BetterThan(A, B) is a comparator that returns true when A is a
107 /// better match than B. The return value is the position of the best match.
108 ///
109 /// This is similar to std::find_if but finds the best of multiple possible
110 /// matches.
111 template <class InputIt, class UnaryPredicate, class Comparator>
112 static InputIt find_best(InputIt First, InputIt Last, UnaryPredicate Predicate,
113  Comparator BetterThan) {
114  InputIt Best = Last;
115 
116  for (InputIt I = First; I != Last; ++I) {
117  unsigned Matched = Predicate(*I);
118  if (Matched != FindBest_NoMatch) {
119  DEBUG(dbgs() << std::distance(First, I) << " is a match (";
120  I->print(dbgs()); dbgs() << ")\n");
121  if (Best == Last || BetterThan(*I, *Best)) {
122  DEBUG(dbgs() << ".. and it beats the last one\n");
123  Best = I;
124  }
125  }
126  if (Matched == FindBest_PerfectMatch) {
127  DEBUG(dbgs() << ".. and it is unbeatable\n");
128  break;
129  }
130  }
131 
132  return Best;
133 }
134 
135 /// Determine the low relocation that matches the given relocation.
136 /// If the relocation does not need a low relocation then the return value
137 /// is ELF::R_MIPS_NONE.
138 ///
139 /// The relocations that need a matching low part are
140 /// R_(MIPS|MICROMIPS|MIPS16)_HI16 for all symbols and
141 /// R_(MIPS|MICROMIPS|MIPS16)_GOT16 for local symbols only.
142 static unsigned getMatchingLoType(const ELFRelocationEntry &Reloc) {
143  unsigned Type = Reloc.Type;
144  if (Type == ELF::R_MIPS_HI16)
145  return ELF::R_MIPS_LO16;
146  if (Type == ELF::R_MICROMIPS_HI16)
147  return ELF::R_MICROMIPS_LO16;
148  if (Type == ELF::R_MIPS16_HI16)
149  return ELF::R_MIPS16_LO16;
150 
151  if (Reloc.OriginalSymbol->getBinding() != ELF::STB_LOCAL)
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  bool IsLittleEndian)
216  : MCELFObjectTargetWriter(Is64, OSABI, ELF::EM_MIPS, HasRelocationAddend) {}
217 
219  const MCValue &Target,
220  const MCFixup &Fixup,
221  bool IsPCRel) const {
222  // Determine the type of the relocation.
223  unsigned Kind = (unsigned)Fixup.getKind();
224 
225  switch (Kind) {
227  return ELF::R_MIPS_NONE;
228  case Mips::fixup_Mips_16:
229  case FK_Data_2:
230  return IsPCRel ? ELF::R_MIPS_PC16 : ELF::R_MIPS_16;
231  case Mips::fixup_Mips_32:
232  case FK_Data_4:
233  return IsPCRel ? ELF::R_MIPS_PC32 : ELF::R_MIPS_32;
234  }
235 
236  if (IsPCRel) {
237  switch (Kind) {
240  return ELF::R_MIPS_PC16;
242  return ELF::R_MICROMIPS_PC7_S1;
244  return ELF::R_MICROMIPS_PC10_S1;
246  return ELF::R_MICROMIPS_PC16_S1;
248  return ELF::R_MICROMIPS_PC26_S1;
250  return ELF::R_MICROMIPS_PC19_S2;
252  return ELF::R_MICROMIPS_PC18_S3;
254  return ELF::R_MICROMIPS_PC21_S1;
256  return ELF::R_MIPS_PC19_S2;
258  return ELF::R_MIPS_PC18_S3;
260  return ELF::R_MIPS_PC21_S2;
262  return ELF::R_MIPS_PC26_S2;
264  return ELF::R_MIPS_PCHI16;
266  return ELF::R_MIPS_PCLO16;
267  }
268 
269  llvm_unreachable("invalid PC-relative fixup kind!");
270  }
271 
272  switch (Kind) {
273  case Mips::fixup_Mips_64:
274  case FK_Data_8:
275  return ELF::R_MIPS_64;
276  case FK_DTPRel_4:
277  return ELF::R_MIPS_TLS_DTPREL32;
278  case FK_DTPRel_8:
279  return ELF::R_MIPS_TLS_DTPREL64;
280  case FK_TPRel_4:
281  return ELF::R_MIPS_TLS_TPREL32;
282  case FK_TPRel_8:
283  return ELF::R_MIPS_TLS_TPREL64;
284  case FK_GPRel_4:
285  if (is64Bit()) {
286  unsigned Type = (unsigned)ELF::R_MIPS_NONE;
287  Type = setRType((unsigned)ELF::R_MIPS_GPREL32, Type);
288  Type = setRType2((unsigned)ELF::R_MIPS_64, Type);
289  Type = setRType3((unsigned)ELF::R_MIPS_NONE, Type);
290  return Type;
291  }
292  return ELF::R_MIPS_GPREL32;
294  return ELF::R_MIPS_GPREL16;
295  case Mips::fixup_Mips_26:
296  return ELF::R_MIPS_26;
298  return ELF::R_MIPS_CALL16;
300  return ELF::R_MIPS_GOT16;
302  return ELF::R_MIPS_HI16;
304  return ELF::R_MIPS_LO16;
306  return ELF::R_MIPS_TLS_GD;
308  return ELF::R_MIPS_TLS_GOTTPREL;
310  return ELF::R_MIPS_TLS_TPREL_HI16;
312  return ELF::R_MIPS_TLS_TPREL_LO16;
314  return ELF::R_MIPS_TLS_LDM;
316  return ELF::R_MIPS_TLS_DTPREL_HI16;
318  return ELF::R_MIPS_TLS_DTPREL_LO16;
320  return ELF::R_MIPS_GOT_PAGE;
322  return ELF::R_MIPS_GOT_OFST;
324  return ELF::R_MIPS_GOT_DISP;
326  unsigned Type = (unsigned)ELF::R_MIPS_NONE;
327  Type = setRType((unsigned)ELF::R_MIPS_GPREL16, Type);
328  Type = setRType2((unsigned)ELF::R_MIPS_SUB, Type);
329  Type = setRType3((unsigned)ELF::R_MIPS_HI16, Type);
330  return Type;
331  }
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_LO16, Type);
337  return Type;
338  }
340  return ELF::R_MIPS_HIGHER;
342  return ELF::R_MIPS_HIGHEST;
344  return ELF::R_MIPS_SUB;
346  return ELF::R_MIPS_GOT_HI16;
348  return ELF::R_MIPS_GOT_LO16;
350  return ELF::R_MIPS_CALL_HI16;
352  return ELF::R_MIPS_CALL_LO16;
354  return ELF::R_MICROMIPS_26_S1;
356  return ELF::R_MICROMIPS_HI16;
358  return ELF::R_MICROMIPS_LO16;
360  return ELF::R_MICROMIPS_GOT16;
362  return ELF::R_MICROMIPS_CALL16;
364  return ELF::R_MICROMIPS_GOT_DISP;
366  return ELF::R_MICROMIPS_GOT_PAGE;
368  return ELF::R_MICROMIPS_GOT_OFST;
370  return ELF::R_MICROMIPS_TLS_GD;
372  return ELF::R_MICROMIPS_TLS_LDM;
374  return ELF::R_MICROMIPS_TLS_DTPREL_HI16;
376  return ELF::R_MICROMIPS_TLS_DTPREL_LO16;
378  return ELF::R_MICROMIPS_TLS_GOTTPREL;
380  return ELF::R_MICROMIPS_TLS_TPREL_HI16;
382  return ELF::R_MICROMIPS_TLS_TPREL_LO16;
384  return ELF::R_MICROMIPS_SUB;
385  }
386 
387  llvm_unreachable("invalid fixup kind!");
388 }
389 
390 /// Sort relocation table entries by offset except where another order is
391 /// required by the MIPS ABI.
392 ///
393 /// MIPS has a few relocations that have an AHL component in the expression used
394 /// to evaluate them. This AHL component is an addend with the same number of
395 /// bits as a symbol value but not all of our ABI's are able to supply a
396 /// sufficiently sized addend in a single relocation.
397 ///
398 /// The O32 ABI for example, uses REL relocations which store the addend in the
399 /// section data. All the relocations with AHL components affect 16-bit fields
400 /// so the addend for a single relocation is limited to 16-bit. This ABI
401 /// resolves the limitation by linking relocations (e.g. R_MIPS_HI16 and
402 /// R_MIPS_LO16) and distributing the addend between the linked relocations. The
403 /// ABI mandates that such relocations must be next to each other in a
404 /// particular order (e.g. R_MIPS_HI16 must be immediately followed by a
405 /// matching R_MIPS_LO16) but the rule is less strict in practice.
406 ///
407 /// The de facto standard is lenient in the following ways:
408 /// - 'Immediately following' does not refer to the next relocation entry but
409 /// the next matching relocation.
410 /// - There may be multiple high parts relocations for one low part relocation.
411 /// - There may be multiple low part relocations for one high part relocation.
412 /// - The AHL addend in each part does not have to be exactly equal as long as
413 /// the difference does not affect the carry bit from bit 15 into 16. This is
414 /// to allow, for example, the use of %lo(foo) and %lo(foo+4) when loading
415 /// both halves of a long long.
416 ///
417 /// See getMatchingLoType() for a description of which high part relocations
418 /// match which low part relocations. One particular thing to note is that
419 /// R_MIPS_GOT16 and similar only have AHL addends if they refer to local
420 /// symbols.
421 ///
422 /// It should also be noted that this function is not affected by whether
423 /// the symbol was kept or rewritten into a section-relative equivalent. We
424 /// always match using the expressions from the source.
425 void MipsELFObjectWriter::sortRelocs(const MCAssembler &Asm,
426  std::vector<ELFRelocationEntry> &Relocs) {
427  // We do not need to sort the relocation table for RELA relocations which
428  // N32/N64 uses as the relocation addend contains the value we require,
429  // rather than it being split across a pair of relocations.
430  if (hasRelocationAddend())
431  return;
432 
433  if (Relocs.size() < 2)
434  return;
435 
436  // Sort relocations by the address they are applied to.
437  std::sort(Relocs.begin(), Relocs.end(),
438  [](const ELFRelocationEntry &A, const ELFRelocationEntry &B) {
439  return A.Offset < B.Offset;
440  });
441 
442  std::list<MipsRelocationEntry> Sorted;
443  std::list<ELFRelocationEntry> Remainder;
444 
445  DEBUG(dumpRelocs("R: ", Relocs));
446 
447  // Separate the movable relocations (AHL relocations using the high bits) from
448  // the immobile relocations (everything else). This does not preserve high/low
449  // matches that already existed in the input.
450  copy_if_else(Relocs.begin(), Relocs.end(), std::back_inserter(Remainder),
451  std::back_inserter(Sorted), [](const ELFRelocationEntry &Reloc) {
452  return getMatchingLoType(Reloc) != ELF::R_MIPS_NONE;
453  });
454 
455  for (auto &R : Remainder) {
456  DEBUG(dbgs() << "Matching: " << R << "\n");
457 
458  unsigned MatchingType = getMatchingLoType(R);
459  assert(MatchingType != ELF::R_MIPS_NONE &&
460  "Wrong list for reloc that doesn't need a match");
461 
462  // Find the best matching relocation for the current high part.
463  // See isMatchingReloc for a description of a matching relocation and
464  // compareMatchingRelocs for a description of what 'best' means.
465  auto InsertionPoint =
466  find_best(Sorted.begin(), Sorted.end(),
467  [&R, &MatchingType](const MipsRelocationEntry &X) {
468  return isMatchingReloc(X, R, MatchingType);
469  },
471 
472  // If we matched then insert the high part in front of the match and mark
473  // both relocations as being involved in a match. We only mark the high
474  // part for cosmetic reasons in the debug output.
475  //
476  // If we failed to find a match then the high part is orphaned. This is not
477  // permitted since the relocation cannot be evaluated without knowing the
478  // carry-in. We can sometimes handle this using a matching low part that is
479  // already used in a match but we already cover that case in
480  // isMatchingReloc and compareMatchingRelocs. For the remaining cases we
481  // should insert the high part at the end of the list. This will cause the
482  // linker to fail but the alternative is to cause the linker to bind the
483  // high part to a semi-matching low part and silently calculate the wrong
484  // value. Unfortunately we have no means to warn the user that we did this
485  // so leave it up to the linker to complain about it.
486  if (InsertionPoint != Sorted.end())
487  InsertionPoint->Matched = true;
488  Sorted.insert(InsertionPoint, R)->Matched = true;
489  }
490 
491  DEBUG(dumpRelocs("S: ", Sorted));
492 
493  assert(Relocs.size() == Sorted.size() && "Some relocs were not consumed");
494 
495  // Overwrite the original vector with the sorted elements. The caller expects
496  // them in reverse order.
497  unsigned CopyTo = 0;
498  for (const auto &R : reverse(Sorted))
499  Relocs[CopyTo++] = R.R;
500 }
501 
502 bool MipsELFObjectWriter::needsRelocateWithSymbol(const MCSymbol &Sym,
503  unsigned Type) const {
504  // If it's a compound relocation for N64 then we need the relocation if any
505  // sub-relocation needs it.
506  if (!isUInt<8>(Type))
507  return needsRelocateWithSymbol(Sym, Type & 0xff) ||
508  needsRelocateWithSymbol(Sym, (Type >> 8) & 0xff) ||
509  needsRelocateWithSymbol(Sym, (Type >> 16) & 0xff);
510 
511  switch (Type) {
512  default:
513  errs() << Type << "\n";
514  llvm_unreachable("Unexpected relocation");
515  return true;
516 
517  // This relocation doesn't affect the section data.
518  case ELF::R_MIPS_NONE:
519  return false;
520 
521  // On REL ABI's (e.g. O32), these relocations form pairs. The pairing is done
522  // by the static linker by matching the symbol and offset.
523  // We only see one relocation at a time but it's still safe to relocate with
524  // the section so long as both relocations make the same decision.
525  //
526  // Some older linkers may require the symbol for particular cases. Such cases
527  // are not supported yet but can be added as required.
528  case ELF::R_MIPS_GOT16:
529  case ELF::R_MIPS16_GOT16:
530  case ELF::R_MICROMIPS_GOT16:
531  case ELF::R_MIPS_HIGHER:
532  case ELF::R_MIPS_HIGHEST:
533  case ELF::R_MIPS_HI16:
534  case ELF::R_MIPS16_HI16:
535  case ELF::R_MICROMIPS_HI16:
536  case ELF::R_MIPS_LO16:
537  case ELF::R_MIPS16_LO16:
538  case ELF::R_MICROMIPS_LO16:
539  // FIXME: It should be safe to return false for the STO_MIPS_MICROMIPS but
540  // we neglect to handle the adjustment to the LSB of the addend that
541  // it causes in applyFixup() and similar.
542  if (cast<MCSymbolELF>(Sym).getOther() & ELF::STO_MIPS_MICROMIPS)
543  return true;
544  return false;
545 
546  case ELF::R_MIPS_GOT_PAGE:
547  case ELF::R_MICROMIPS_GOT_PAGE:
548  case ELF::R_MIPS_GOT_OFST:
549  case ELF::R_MICROMIPS_GOT_OFST:
550  case ELF::R_MIPS_16:
551  case ELF::R_MIPS_32:
552  case ELF::R_MIPS_GPREL32:
553  if (cast<MCSymbolELF>(Sym).getOther() & ELF::STO_MIPS_MICROMIPS)
554  return true;
556  case ELF::R_MIPS_26:
557  case ELF::R_MIPS_64:
558  case ELF::R_MIPS_GPREL16:
559  case ELF::R_MIPS_PC16:
560  case ELF::R_MIPS_SUB:
561  return false;
562 
563  // FIXME: Many of these relocations should probably return false but this
564  // hasn't been confirmed to be safe yet.
565  case ELF::R_MIPS_REL32:
566  case ELF::R_MIPS_LITERAL:
567  case ELF::R_MIPS_CALL16:
568  case ELF::R_MIPS_SHIFT5:
569  case ELF::R_MIPS_SHIFT6:
570  case ELF::R_MIPS_GOT_DISP:
571  case ELF::R_MIPS_GOT_HI16:
572  case ELF::R_MIPS_GOT_LO16:
573  case ELF::R_MIPS_INSERT_A:
574  case ELF::R_MIPS_INSERT_B:
575  case ELF::R_MIPS_DELETE:
576  case ELF::R_MIPS_CALL_HI16:
577  case ELF::R_MIPS_CALL_LO16:
578  case ELF::R_MIPS_SCN_DISP:
579  case ELF::R_MIPS_REL16:
580  case ELF::R_MIPS_ADD_IMMEDIATE:
581  case ELF::R_MIPS_PJUMP:
582  case ELF::R_MIPS_RELGOT:
583  case ELF::R_MIPS_JALR:
584  case ELF::R_MIPS_TLS_DTPMOD32:
585  case ELF::R_MIPS_TLS_DTPREL32:
586  case ELF::R_MIPS_TLS_DTPMOD64:
587  case ELF::R_MIPS_TLS_DTPREL64:
588  case ELF::R_MIPS_TLS_GD:
589  case ELF::R_MIPS_TLS_LDM:
590  case ELF::R_MIPS_TLS_DTPREL_HI16:
591  case ELF::R_MIPS_TLS_DTPREL_LO16:
592  case ELF::R_MIPS_TLS_GOTTPREL:
593  case ELF::R_MIPS_TLS_TPREL32:
594  case ELF::R_MIPS_TLS_TPREL64:
595  case ELF::R_MIPS_TLS_TPREL_HI16:
596  case ELF::R_MIPS_TLS_TPREL_LO16:
597  case ELF::R_MIPS_GLOB_DAT:
598  case ELF::R_MIPS_PC21_S2:
599  case ELF::R_MIPS_PC26_S2:
600  case ELF::R_MIPS_PC18_S3:
601  case ELF::R_MIPS_PC19_S2:
602  case ELF::R_MIPS_PCHI16:
603  case ELF::R_MIPS_PCLO16:
604  case ELF::R_MIPS_COPY:
605  case ELF::R_MIPS_JUMP_SLOT:
606  case ELF::R_MIPS_NUM:
607  case ELF::R_MIPS_PC32:
608  case ELF::R_MIPS_EH:
609  case ELF::R_MICROMIPS_26_S1:
610  case ELF::R_MICROMIPS_GPREL16:
611  case ELF::R_MICROMIPS_LITERAL:
612  case ELF::R_MICROMIPS_PC7_S1:
613  case ELF::R_MICROMIPS_PC10_S1:
614  case ELF::R_MICROMIPS_PC16_S1:
615  case ELF::R_MICROMIPS_CALL16:
616  case ELF::R_MICROMIPS_GOT_DISP:
617  case ELF::R_MICROMIPS_GOT_HI16:
618  case ELF::R_MICROMIPS_GOT_LO16:
619  case ELF::R_MICROMIPS_SUB:
620  case ELF::R_MICROMIPS_HIGHER:
621  case ELF::R_MICROMIPS_HIGHEST:
622  case ELF::R_MICROMIPS_CALL_HI16:
623  case ELF::R_MICROMIPS_CALL_LO16:
624  case ELF::R_MICROMIPS_SCN_DISP:
625  case ELF::R_MICROMIPS_JALR:
626  case ELF::R_MICROMIPS_HI0_LO16:
627  case ELF::R_MICROMIPS_TLS_GD:
628  case ELF::R_MICROMIPS_TLS_LDM:
629  case ELF::R_MICROMIPS_TLS_DTPREL_HI16:
630  case ELF::R_MICROMIPS_TLS_DTPREL_LO16:
631  case ELF::R_MICROMIPS_TLS_GOTTPREL:
632  case ELF::R_MICROMIPS_TLS_TPREL_HI16:
633  case ELF::R_MICROMIPS_TLS_TPREL_LO16:
634  case ELF::R_MICROMIPS_GPREL7_S2:
635  case ELF::R_MICROMIPS_PC23_S2:
636  case ELF::R_MICROMIPS_PC21_S1:
637  case ELF::R_MICROMIPS_PC26_S1:
638  case ELF::R_MICROMIPS_PC18_S3:
639  case ELF::R_MICROMIPS_PC19_S2:
640  return true;
641 
642  // FIXME: Many of these should probably return false but MIPS16 isn't
643  // supported by the integrated assembler.
644  case ELF::R_MIPS16_26:
645  case ELF::R_MIPS16_GPREL:
646  case ELF::R_MIPS16_CALL16:
647  case ELF::R_MIPS16_TLS_GD:
648  case ELF::R_MIPS16_TLS_LDM:
649  case ELF::R_MIPS16_TLS_DTPREL_HI16:
650  case ELF::R_MIPS16_TLS_DTPREL_LO16:
651  case ELF::R_MIPS16_TLS_GOTTPREL:
652  case ELF::R_MIPS16_TLS_TPREL_HI16:
653  case ELF::R_MIPS16_TLS_TPREL_LO16:
654  llvm_unreachable("Unsupported MIPS16 relocation");
655  return true;
656  }
657 }
658 
659 std::unique_ptr<MCObjectWriter>
661  bool IsN32) {
662  uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TT.getOS());
663  bool IsN64 = TT.isArch64Bit() && !IsN32;
664  bool HasRelocationAddend = TT.isArch64Bit();
665  auto MOTW = llvm::make_unique<MipsELFObjectWriter>(
666  OSABI, HasRelocationAddend, IsN64, TT.isLittleEndian());
667  return createELFObjectWriter(std::move(MOTW), OS, TT.isLittleEndian());
668 }
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:37
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
This represents an "assembler immediate".
Definition: MCValue.h:40
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:42
OSType getOS() const
getOS - Get the parsed operating system type of this triple.
Definition: Triple.h:294
unsigned getBinding() const
Definition: MCSymbolELF.cpp:68
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:66
A four-byte tp relative fixup.
Definition: MCFixup.h:38
std::unique_ptr< MCObjectWriter > createMipsELFObjectWriter(raw_pwrite_stream &OS, const Triple &TT, bool IsN32)
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:59
auto reverse(ContainerTy &&C, typename std::enable_if< has_rbegin< ContainerTy >::value >::type *=nullptr) -> decltype(make_range(C.rbegin(), C.rend()))
Definition: STLExtras.h:232
A four-byte gp relative fixup.
Definition: MCFixup.h:34
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...
std::unique_ptr< MCObjectWriter > createELFObjectWriter(std::unique_ptr< MCELFObjectTargetWriter > MOTW, raw_pwrite_stream &OS, bool IsLittleEndian)
Construct a new ELF writer instance.
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:36
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
constexpr bool isUInt< 8 >(uint64_t x)
Definition: MathExtras.h:335
bool isLittleEndian() const
Tests whether the target triple is little endian.
Definition: Triple.cpp:1470
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.
static void print(raw_ostream &Out, object::Archive::Kind Kind, T Val)
A eight-byte tp relative fixup.
Definition: MCFixup.h:39
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:44
PowerPC TLS Dynamic Call Fixup
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:27
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:1243
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:2018
An abstract base class for streams implementations that also support a pwrite operation.
Definition: raw_ostream.h:337
const MCSymbolELF * OriginalSymbol
const unsigned Kind
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
#define LLVM_FALLTHROUGH
LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements.
Definition: Compiler.h:235
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
#define DEBUG(X)
Definition: Debug.h:118
static unsigned getMatchingLoType(const ELFRelocationEntry &Reloc)
Determine the low relocation that matches the given relocation.
void sort(Policy policy, RandomAccessIterator Start, RandomAccessIterator End, const Comparator &Comp=Comparator())
Definition: Parallel.h:199
A two-byte fixup.
Definition: MCFixup.h:25
MCFixupKind getKind() const
Definition: MCFixup.h:93