1 //===-- AArch64ELFObjectWriter.cpp - AArch64 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 //
9 // This file handles ELF-specific object emission, converting LLVM's internal
10 // fixups into the appropriate relocations.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "MCTargetDesc/AArch64FixupKinds.h"
15 #include "MCTargetDesc/AArch64MCExpr.h"
16 #include "MCTargetDesc/AArch64MCTargetDesc.h"
17 #include "llvm/BinaryFormat/ELF.h"
18 #include "llvm/MC/MCContext.h"
19 #include "llvm/MC/MCELFObjectWriter.h"
20 #include "llvm/MC/MCFixup.h"
21 #include "llvm/MC/MCObjectWriter.h"
22 #include "llvm/MC/MCValue.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include <cassert>
25 #include <cstdint>
26 
27 using namespace llvm;
28 
29 namespace {
30 
31 class AArch64ELFObjectWriter : public MCELFObjectTargetWriter {
32 public:
33   AArch64ELFObjectWriter(uint8_t OSABI, bool IsILP32);
34 
35   ~AArch64ELFObjectWriter() override = default;
36 
37 protected:
38   unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
39                         const MCFixup &Fixup, bool IsPCRel) const override;
40   bool IsILP32;
41 };
42 
43 } // end anonymous namespace
44 
45 AArch64ELFObjectWriter::AArch64ELFObjectWriter(uint8_t OSABI, bool IsILP32)
46     : MCELFObjectTargetWriter(/*Is64Bit*/ true, OSABI, ELF::EM_AARCH64,
47                               /*HasRelocationAddend*/ true),
48       IsILP32(IsILP32) {}
49 
50 #define R_CLS(rtype)                                                           \
51   IsILP32 ? ELF::R_AARCH64_P32_##rtype : ELF::R_AARCH64_##rtype
52 #define BAD_ILP32_MOV(lp64rtype)                                               \
53   "ILP32 absolute MOV relocation not "                                         \
54   "supported (LP64 eqv: " #lp64rtype ")"
55 
56 // assumes IsILP32 is true
57 static bool isNonILP32reloc(const MCFixup &Fixup,
58                             AArch64MCExpr::VariantKind RefKind,
59                             MCContext &Ctx) {
60   if (Fixup.getTargetKind() != AArch64::fixup_aarch64_movw)
61     return false;
62   switch (RefKind) {
63   case AArch64MCExpr::VK_ABS_G3:
64     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_UABS_G3));
65     return true;
66   case AArch64MCExpr::VK_ABS_G2:
67     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_UABS_G2));
68     return true;
69   case AArch64MCExpr::VK_ABS_G2_S:
70     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_SABS_G2));
71     return true;
72   case AArch64MCExpr::VK_ABS_G2_NC:
73     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_UABS_G2_NC));
74     return true;
75   case AArch64MCExpr::VK_ABS_G1_S:
76     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_SABS_G1));
77     return true;
78   case AArch64MCExpr::VK_ABS_G1_NC:
79     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(MOVW_UABS_G1_NC));
80     return true;
81   case AArch64MCExpr::VK_DTPREL_G2:
82     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSLD_MOVW_DTPREL_G2));
83     return true;
84   case AArch64MCExpr::VK_DTPREL_G1_NC:
85     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSLD_MOVW_DTPREL_G1_NC));
86     return true;
87   case AArch64MCExpr::VK_TPREL_G2:
88     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSLE_MOVW_TPREL_G2));
89     return true;
90   case AArch64MCExpr::VK_TPREL_G1_NC:
91     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSLE_MOVW_TPREL_G1_NC));
92     return true;
93   case AArch64MCExpr::VK_GOTTPREL_G1:
94     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSIE_MOVW_GOTTPREL_G1));
95     return true;
96   case AArch64MCExpr::VK_GOTTPREL_G0_NC:
97     Ctx.reportError(Fixup.getLoc(), BAD_ILP32_MOV(TLSIE_MOVW_GOTTPREL_G0_NC));
98     return true;
99   default:
100     return false;
101   }
102   return false;
103 }
104 
105 unsigned AArch64ELFObjectWriter::getRelocType(MCContext &Ctx,
106                                               const MCValue &Target,
107                                               const MCFixup &Fixup,
108                                               bool IsPCRel) const {
109   unsigned Kind = Fixup.getTargetKind();
110   if (Kind >= FirstLiteralRelocationKind)
111     return Kind - FirstLiteralRelocationKind;
112   AArch64MCExpr::VariantKind RefKind =
113       static_cast<AArch64MCExpr::VariantKind>(Target.getRefKind());
114   AArch64MCExpr::VariantKind SymLoc = AArch64MCExpr::getSymbolLoc(RefKind);
115   bool IsNC = AArch64MCExpr::isNotChecked(RefKind);
116 
117   assert((!Target.getSymA() ||
118           Target.getSymA()->getKind() == MCSymbolRefExpr::VK_None ||
119           Target.getSymA()->getKind() == MCSymbolRefExpr::VK_PLT) &&
120          "Should only be expression-level modifiers here");
121 
122   assert((!Target.getSymB() ||
123           Target.getSymB()->getKind() == MCSymbolRefExpr::VK_None) &&
124          "Should only be expression-level modifiers here");
125 
126   if (IsPCRel) {
127     switch (Kind) {
128     case FK_Data_1:
129       Ctx.reportError(Fixup.getLoc(), "1-byte data relocations not supported");
130       return ELF::R_AARCH64_NONE;
131     case FK_Data_2:
132       return R_CLS(PREL16);
133     case FK_Data_4: {
134       return Target.getAccessVariant() == MCSymbolRefExpr::VK_PLT
135                  ? R_CLS(PLT32)
136                  : R_CLS(PREL32);
137     }
138     case FK_Data_8:
139       if (IsILP32) {
140         Ctx.reportError(Fixup.getLoc(),
141                         "ILP32 8 byte PC relative data "
142                         "relocation not supported (LP64 eqv: PREL64)");
143         return ELF::R_AARCH64_NONE;
144       } else
145         return ELF::R_AARCH64_PREL64;
146     case AArch64::fixup_aarch64_pcrel_adr_imm21:
147       if (SymLoc != AArch64MCExpr::VK_ABS)
148         Ctx.reportError(Fixup.getLoc(),
149                         "invalid symbol kind for ADR relocation");
150       return R_CLS(ADR_PREL_LO21);
151     case AArch64::fixup_aarch64_pcrel_adrp_imm21:
152       if (SymLoc == AArch64MCExpr::VK_ABS && !IsNC)
153         return R_CLS(ADR_PREL_PG_HI21);
154       if (SymLoc == AArch64MCExpr::VK_ABS && IsNC) {
155         if (IsILP32) {
156           Ctx.reportError(Fixup.getLoc(),
157                           "invalid fixup for 32-bit pcrel ADRP instruction "
158                           "VK_ABS VK_NC");
159           return ELF::R_AARCH64_NONE;
160         } else {
161           return ELF::R_AARCH64_ADR_PREL_PG_HI21_NC;
162         }
163       }
164       if (SymLoc == AArch64MCExpr::VK_GOT && !IsNC)
165         return R_CLS(ADR_GOT_PAGE);
166       if (SymLoc == AArch64MCExpr::VK_GOTTPREL && !IsNC)
167         return R_CLS(TLSIE_ADR_GOTTPREL_PAGE21);
168       if (SymLoc == AArch64MCExpr::VK_TLSDESC && !IsNC)
169         return R_CLS(TLSDESC_ADR_PAGE21);
170       Ctx.reportError(Fixup.getLoc(),
171                       "invalid symbol kind for ADRP relocation");
172       return ELF::R_AARCH64_NONE;
173     case AArch64::fixup_aarch64_pcrel_branch26:
174       return R_CLS(JUMP26);
175     case AArch64::fixup_aarch64_pcrel_call26:
176       return R_CLS(CALL26);
177     case AArch64::fixup_aarch64_ldr_pcrel_imm19:
178       if (SymLoc == AArch64MCExpr::VK_GOTTPREL)
179         return R_CLS(TLSIE_LD_GOTTPREL_PREL19);
180       if (SymLoc == AArch64MCExpr::VK_GOT)
181         return R_CLS(GOT_LD_PREL19);
182       return R_CLS(LD_PREL_LO19);
183     case AArch64::fixup_aarch64_pcrel_branch14:
184       return R_CLS(TSTBR14);
185     case AArch64::fixup_aarch64_pcrel_branch19:
186       return R_CLS(CONDBR19);
187     default:
188       Ctx.reportError(Fixup.getLoc(), "Unsupported pc-relative fixup kind");
189       return ELF::R_AARCH64_NONE;
190     }
191   } else {
192     if (IsILP32 && isNonILP32reloc(Fixup, RefKind, Ctx))
193       return ELF::R_AARCH64_NONE;
194     switch (Fixup.getTargetKind()) {
195     case FK_Data_1:
196       Ctx.reportError(Fixup.getLoc(), "1-byte data relocations not supported");
197       return ELF::R_AARCH64_NONE;
198     case FK_Data_2:
199       return R_CLS(ABS16);
200     case FK_Data_4:
201       return R_CLS(ABS32);
202     case FK_Data_8:
203       if (IsILP32) {
204         Ctx.reportError(Fixup.getLoc(),
205                         "ILP32 8 byte absolute data "
206                         "relocation not supported (LP64 eqv: ABS64)");
207         return ELF::R_AARCH64_NONE;
208       } else
209         return ELF::R_AARCH64_ABS64;
210     case AArch64::fixup_aarch64_add_imm12:
211       if (RefKind == AArch64MCExpr::VK_DTPREL_HI12)
212         return R_CLS(TLSLD_ADD_DTPREL_HI12);
213       if (RefKind == AArch64MCExpr::VK_TPREL_HI12)
214         return R_CLS(TLSLE_ADD_TPREL_HI12);
215       if (RefKind == AArch64MCExpr::VK_DTPREL_LO12_NC)
216         return R_CLS(TLSLD_ADD_DTPREL_LO12_NC);
217       if (RefKind == AArch64MCExpr::VK_DTPREL_LO12)
218         return R_CLS(TLSLD_ADD_DTPREL_LO12);
219       if (RefKind == AArch64MCExpr::VK_TPREL_LO12_NC)
220         return R_CLS(TLSLE_ADD_TPREL_LO12_NC);
221       if (RefKind == AArch64MCExpr::VK_TPREL_LO12)
222         return R_CLS(TLSLE_ADD_TPREL_LO12);
223       if (RefKind == AArch64MCExpr::VK_TLSDESC_LO12)
224         return R_CLS(TLSDESC_ADD_LO12);
225       if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
226         return R_CLS(ADD_ABS_LO12_NC);
227 
228       Ctx.reportError(Fixup.getLoc(),
229                       "invalid fixup for add (uimm12) instruction");
230       return ELF::R_AARCH64_NONE;
231     case AArch64::fixup_aarch64_ldst_imm12_scale1:
232       if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
233         return R_CLS(LDST8_ABS_LO12_NC);
234       if (SymLoc == AArch64MCExpr::VK_DTPREL && !IsNC)
235         return R_CLS(TLSLD_LDST8_DTPREL_LO12);
236       if (SymLoc == AArch64MCExpr::VK_DTPREL && IsNC)
237         return R_CLS(TLSLD_LDST8_DTPREL_LO12_NC);
238       if (SymLoc == AArch64MCExpr::VK_TPREL && !IsNC)
239         return R_CLS(TLSLE_LDST8_TPREL_LO12);
240       if (SymLoc == AArch64MCExpr::VK_TPREL && IsNC)
241         return R_CLS(TLSLE_LDST8_TPREL_LO12_NC);
242 
243       Ctx.reportError(Fixup.getLoc(),
244                       "invalid fixup for 8-bit load/store instruction");
245       return ELF::R_AARCH64_NONE;
246     case AArch64::fixup_aarch64_ldst_imm12_scale2:
247       if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
248         return R_CLS(LDST16_ABS_LO12_NC);
249       if (SymLoc == AArch64MCExpr::VK_DTPREL && !IsNC)
250         return R_CLS(TLSLD_LDST16_DTPREL_LO12);
251       if (SymLoc == AArch64MCExpr::VK_DTPREL && IsNC)
252         return R_CLS(TLSLD_LDST16_DTPREL_LO12_NC);
253       if (SymLoc == AArch64MCExpr::VK_TPREL && !IsNC)
254         return R_CLS(TLSLE_LDST16_TPREL_LO12);
255       if (SymLoc == AArch64MCExpr::VK_TPREL && IsNC)
256         return R_CLS(TLSLE_LDST16_TPREL_LO12_NC);
257 
258       Ctx.reportError(Fixup.getLoc(),
259                       "invalid fixup for 16-bit load/store instruction");
260       return ELF::R_AARCH64_NONE;
261     case AArch64::fixup_aarch64_ldst_imm12_scale4:
262       if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
263         return R_CLS(LDST32_ABS_LO12_NC);
264       if (SymLoc == AArch64MCExpr::VK_DTPREL && !IsNC)
265         return R_CLS(TLSLD_LDST32_DTPREL_LO12);
266       if (SymLoc == AArch64MCExpr::VK_DTPREL && IsNC)
267         return R_CLS(TLSLD_LDST32_DTPREL_LO12_NC);
268       if (SymLoc == AArch64MCExpr::VK_TPREL && !IsNC)
269         return R_CLS(TLSLE_LDST32_TPREL_LO12);
270       if (SymLoc == AArch64MCExpr::VK_TPREL && IsNC)
271         return R_CLS(TLSLE_LDST32_TPREL_LO12_NC);
272       if (SymLoc == AArch64MCExpr::VK_GOT && IsNC) {
273         if (IsILP32) {
274           return ELF::R_AARCH64_P32_LD32_GOT_LO12_NC;
275         } else {
276           Ctx.reportError(Fixup.getLoc(),
277                           "LP64 4 byte unchecked GOT load/store relocation "
278                           "not supported (ILP32 eqv: LD32_GOT_LO12_NC");
279           return ELF::R_AARCH64_NONE;
280         }
281       }
282       if (SymLoc == AArch64MCExpr::VK_GOT && !IsNC) {
283         if (IsILP32) {
284           Ctx.reportError(Fixup.getLoc(),
285                           "ILP32 4 byte checked GOT load/store relocation "
286                           "not supported (unchecked eqv: LD32_GOT_LO12_NC)");
287         } else {
288           Ctx.reportError(Fixup.getLoc(),
289                           "LP64 4 byte checked GOT load/store relocation "
290                           "not supported (unchecked/ILP32 eqv: "
291                           "LD32_GOT_LO12_NC)");
292         }
293         return ELF::R_AARCH64_NONE;
294       }
295       if (SymLoc == AArch64MCExpr::VK_GOTTPREL && IsNC) {
296         if (IsILP32) {
297           return ELF::R_AARCH64_P32_TLSIE_LD32_GOTTPREL_LO12_NC;
298         } else {
299           Ctx.reportError(Fixup.getLoc(),
300                           "LP64 32-bit load/store "
301                           "relocation not supported (ILP32 eqv: "
302                           "TLSIE_LD32_GOTTPREL_LO12_NC)");
303           return ELF::R_AARCH64_NONE;
304         }
305       }
306       if (SymLoc == AArch64MCExpr::VK_TLSDESC && !IsNC) {
307         if (IsILP32) {
308           return ELF::R_AARCH64_P32_TLSDESC_LD32_LO12;
309         } else {
310           Ctx.reportError(Fixup.getLoc(),
311                           "LP64 4 byte TLSDESC load/store relocation "
312                           "not supported (ILP32 eqv: TLSDESC_LD64_LO12)");
313           return ELF::R_AARCH64_NONE;
314         }
315       }
316 
317       Ctx.reportError(Fixup.getLoc(),
318                       "invalid fixup for 32-bit load/store instruction "
319                       "fixup_aarch64_ldst_imm12_scale4");
320       return ELF::R_AARCH64_NONE;
321     case AArch64::fixup_aarch64_ldst_imm12_scale8:
322       if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
323         return R_CLS(LDST64_ABS_LO12_NC);
324       if (SymLoc == AArch64MCExpr::VK_GOT && IsNC) {
325         if (!IsILP32) {
326           return ELF::R_AARCH64_LD64_GOT_LO12_NC;
327         } else {
328           Ctx.reportError(Fixup.getLoc(), "ILP32 64-bit load/store "
329                                           "relocation not supported (LP64 eqv: "
330                                           "LD64_GOT_LO12_NC)");
331           return ELF::R_AARCH64_NONE;
332         }
333       }
334       if (SymLoc == AArch64MCExpr::VK_DTPREL && !IsNC)
335         return R_CLS(TLSLD_LDST64_DTPREL_LO12);
336       if (SymLoc == AArch64MCExpr::VK_DTPREL && IsNC)
337         return R_CLS(TLSLD_LDST64_DTPREL_LO12_NC);
338       if (SymLoc == AArch64MCExpr::VK_TPREL && !IsNC)
339         return R_CLS(TLSLE_LDST64_TPREL_LO12);
340       if (SymLoc == AArch64MCExpr::VK_TPREL && IsNC)
341         return R_CLS(TLSLE_LDST64_TPREL_LO12_NC);
342       if (SymLoc == AArch64MCExpr::VK_GOTTPREL && IsNC) {
343         if (!IsILP32) {
344           return ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC;
345         } else {
346           Ctx.reportError(Fixup.getLoc(), "ILP32 64-bit load/store "
347                                           "relocation not supported (LP64 eqv: "
348                                           "TLSIE_LD64_GOTTPREL_LO12_NC)");
349           return ELF::R_AARCH64_NONE;
350         }
351       }
352       if (SymLoc == AArch64MCExpr::VK_TLSDESC) {
353         if (!IsILP32) {
354           return ELF::R_AARCH64_TLSDESC_LD64_LO12;
355         } else {
356           Ctx.reportError(Fixup.getLoc(), "ILP32 64-bit load/store "
357                                           "relocation not supported (LP64 eqv: "
358                                           "TLSDESC_LD64_LO12)");
359           return ELF::R_AARCH64_NONE;
360         }
361       }
362       Ctx.reportError(Fixup.getLoc(),
363                       "invalid fixup for 64-bit load/store instruction");
364       return ELF::R_AARCH64_NONE;
365     case AArch64::fixup_aarch64_ldst_imm12_scale16:
366       if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
367         return R_CLS(LDST128_ABS_LO12_NC);
368       if (SymLoc == AArch64MCExpr::VK_DTPREL && !IsNC)
369         return R_CLS(TLSLD_LDST128_DTPREL_LO12);
370       if (SymLoc == AArch64MCExpr::VK_DTPREL && IsNC)
371         return R_CLS(TLSLD_LDST128_DTPREL_LO12_NC);
372       if (SymLoc == AArch64MCExpr::VK_TPREL && !IsNC)
373         return R_CLS(TLSLE_LDST128_TPREL_LO12);
374       if (SymLoc == AArch64MCExpr::VK_TPREL && IsNC)
375         return R_CLS(TLSLE_LDST128_TPREL_LO12_NC);
376 
377       Ctx.reportError(Fixup.getLoc(),
378                       "invalid fixup for 128-bit load/store instruction");
379       return ELF::R_AARCH64_NONE;
380     // ILP32 case not reached here, tested with isNonILP32reloc
381     case AArch64::fixup_aarch64_movw:
382       if (RefKind == AArch64MCExpr::VK_ABS_G3)
383         return ELF::R_AARCH64_MOVW_UABS_G3;
384       if (RefKind == AArch64MCExpr::VK_ABS_G2)
385         return ELF::R_AARCH64_MOVW_UABS_G2;
386       if (RefKind == AArch64MCExpr::VK_ABS_G2_S)
387         return ELF::R_AARCH64_MOVW_SABS_G2;
388       if (RefKind == AArch64MCExpr::VK_ABS_G2_NC)
389         return ELF::R_AARCH64_MOVW_UABS_G2_NC;
390       if (RefKind == AArch64MCExpr::VK_ABS_G1)
391         return R_CLS(MOVW_UABS_G1);
392       if (RefKind == AArch64MCExpr::VK_ABS_G1_S)
393         return ELF::R_AARCH64_MOVW_SABS_G1;
394       if (RefKind == AArch64MCExpr::VK_ABS_G1_NC)
395         return ELF::R_AARCH64_MOVW_UABS_G1_NC;
396       if (RefKind == AArch64MCExpr::VK_ABS_G0)
397         return R_CLS(MOVW_UABS_G0);
398       if (RefKind == AArch64MCExpr::VK_ABS_G0_S)
399         return R_CLS(MOVW_SABS_G0);
400       if (RefKind == AArch64MCExpr::VK_ABS_G0_NC)
401         return R_CLS(MOVW_UABS_G0_NC);
402       if (RefKind == AArch64MCExpr::VK_PREL_G3)
403         return ELF::R_AARCH64_MOVW_PREL_G3;
404       if (RefKind == AArch64MCExpr::VK_PREL_G2)
405         return ELF::R_AARCH64_MOVW_PREL_G2;
406       if (RefKind == AArch64MCExpr::VK_PREL_G2_NC)
407         return ELF::R_AARCH64_MOVW_PREL_G2_NC;
408       if (RefKind == AArch64MCExpr::VK_PREL_G1)
409         return R_CLS(MOVW_PREL_G1);
410       if (RefKind == AArch64MCExpr::VK_PREL_G1_NC)
411         return ELF::R_AARCH64_MOVW_PREL_G1_NC;
412       if (RefKind == AArch64MCExpr::VK_PREL_G0)
413         return R_CLS(MOVW_PREL_G0);
414       if (RefKind == AArch64MCExpr::VK_PREL_G0_NC)
415         return R_CLS(MOVW_PREL_G0_NC);
416       if (RefKind == AArch64MCExpr::VK_DTPREL_G2)
417         return ELF::R_AARCH64_TLSLD_MOVW_DTPREL_G2;
418       if (RefKind == AArch64MCExpr::VK_DTPREL_G1)
419         return R_CLS(TLSLD_MOVW_DTPREL_G1);
420       if (RefKind == AArch64MCExpr::VK_DTPREL_G1_NC)
421         return ELF::R_AARCH64_TLSLD_MOVW_DTPREL_G1_NC;
422       if (RefKind == AArch64MCExpr::VK_DTPREL_G0)
423         return R_CLS(TLSLD_MOVW_DTPREL_G0);
424       if (RefKind == AArch64MCExpr::VK_DTPREL_G0_NC)
425         return R_CLS(TLSLD_MOVW_DTPREL_G0_NC);
426       if (RefKind == AArch64MCExpr::VK_TPREL_G2)
427         return ELF::R_AARCH64_TLSLE_MOVW_TPREL_G2;
428       if (RefKind == AArch64MCExpr::VK_TPREL_G1)
429         return R_CLS(TLSLE_MOVW_TPREL_G1);
430       if (RefKind == AArch64MCExpr::VK_TPREL_G1_NC)
431         return ELF::R_AARCH64_TLSLE_MOVW_TPREL_G1_NC;
432       if (RefKind == AArch64MCExpr::VK_TPREL_G0)
433         return R_CLS(TLSLE_MOVW_TPREL_G0);
434       if (RefKind == AArch64MCExpr::VK_TPREL_G0_NC)
435         return R_CLS(TLSLE_MOVW_TPREL_G0_NC);
436       if (RefKind == AArch64MCExpr::VK_GOTTPREL_G1)
437         return ELF::R_AARCH64_TLSIE_MOVW_GOTTPREL_G1;
438       if (RefKind == AArch64MCExpr::VK_GOTTPREL_G0_NC)
439         return ELF::R_AARCH64_TLSIE_MOVW_GOTTPREL_G0_NC;
440       Ctx.reportError(Fixup.getLoc(),
441                       "invalid fixup for movz/movk instruction");
442       return ELF::R_AARCH64_NONE;
443     case AArch64::fixup_aarch64_tlsdesc_call:
444       return R_CLS(TLSDESC_CALL);
445     default:
446       Ctx.reportError(Fixup.getLoc(), "Unknown ELF relocation type");
447       return ELF::R_AARCH64_NONE;
448     }
449   }
450 
451   llvm_unreachable("Unimplemented fixup -> relocation");
452 }
453 
454 std::unique_ptr<MCObjectTargetWriter>
455 llvm::createAArch64ELFObjectWriter(uint8_t OSABI, bool IsILP32) {
456   return std::make_unique<AArch64ELFObjectWriter>(OSABI, IsILP32);
457 }
458