1 //===-- PPCELFObjectWriter.cpp - PPC 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
10 #include "MCTargetDesc/PPCMCTargetDesc.h"
11 #include "MCTargetDesc/PPCFixupKinds.h"
12 #include "llvm/ADT/STLExtras.h"
13 #include "llvm/MC/MCELFObjectWriter.h"
14 #include "llvm/MC/MCExpr.h"
15 #include "llvm/MC/MCValue.h"
16 #include "llvm/Support/ErrorHandling.h"
17
18 using namespace llvm;
19
20 namespace {
21 class PPCELFObjectWriter : public MCELFObjectTargetWriter {
22 public:
23 PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI);
24
25 virtual ~PPCELFObjectWriter();
26 protected:
27 virtual unsigned getRelocTypeInner(const MCValue &Target,
28 const MCFixup &Fixup,
29 bool IsPCRel) const;
30 virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
31 bool IsPCRel, bool IsRelocWithSymbol,
32 int64_t Addend) const;
33 virtual const MCSymbol *ExplicitRelSym(const MCAssembler &Asm,
34 const MCValue &Target,
35 const MCFragment &F,
36 const MCFixup &Fixup,
37 bool IsPCRel) const;
38 virtual const MCSymbol *undefinedExplicitRelSym(const MCValue &Target,
39 const MCFixup &Fixup,
40 bool IsPCRel) const;
41 };
42 }
43
PPCELFObjectWriter(bool Is64Bit,uint8_t OSABI)44 PPCELFObjectWriter::PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI)
45 : MCELFObjectTargetWriter(Is64Bit, OSABI,
46 Is64Bit ? ELF::EM_PPC64 : ELF::EM_PPC,
47 /*HasRelocationAddend*/ true) {}
48
~PPCELFObjectWriter()49 PPCELFObjectWriter::~PPCELFObjectWriter() {
50 }
51
getRelocTypeInner(const MCValue & Target,const MCFixup & Fixup,bool IsPCRel) const52 unsigned PPCELFObjectWriter::getRelocTypeInner(const MCValue &Target,
53 const MCFixup &Fixup,
54 bool IsPCRel) const
55 {
56 MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ?
57 MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
58
59 // determine the type of the relocation
60 unsigned Type;
61 if (IsPCRel) {
62 switch ((unsigned)Fixup.getKind()) {
63 default:
64 llvm_unreachable("Unimplemented");
65 case PPC::fixup_ppc_br24:
66 case PPC::fixup_ppc_br24abs:
67 Type = ELF::R_PPC_REL24;
68 break;
69 case PPC::fixup_ppc_brcond14:
70 case PPC::fixup_ppc_brcond14abs:
71 Type = ELF::R_PPC_REL14;
72 break;
73 case PPC::fixup_ppc_half16:
74 switch (Modifier) {
75 default: llvm_unreachable("Unsupported Modifier");
76 case MCSymbolRefExpr::VK_None:
77 Type = ELF::R_PPC_REL16;
78 break;
79 case MCSymbolRefExpr::VK_PPC_LO:
80 Type = ELF::R_PPC_REL16_LO;
81 break;
82 case MCSymbolRefExpr::VK_PPC_HI:
83 Type = ELF::R_PPC_REL16_HI;
84 break;
85 case MCSymbolRefExpr::VK_PPC_HA:
86 Type = ELF::R_PPC_REL16_HA;
87 break;
88 }
89 break;
90 case FK_Data_4:
91 case FK_PCRel_4:
92 Type = ELF::R_PPC_REL32;
93 break;
94 case FK_Data_8:
95 case FK_PCRel_8:
96 Type = ELF::R_PPC64_REL64;
97 break;
98 }
99 } else {
100 switch ((unsigned)Fixup.getKind()) {
101 default: llvm_unreachable("invalid fixup kind!");
102 case PPC::fixup_ppc_br24abs:
103 Type = ELF::R_PPC_ADDR24;
104 break;
105 case PPC::fixup_ppc_brcond14abs:
106 Type = ELF::R_PPC_ADDR14; // XXX: or BRNTAKEN?_
107 break;
108 case PPC::fixup_ppc_half16:
109 switch (Modifier) {
110 default: llvm_unreachable("Unsupported Modifier");
111 case MCSymbolRefExpr::VK_None:
112 Type = ELF::R_PPC_ADDR16;
113 break;
114 case MCSymbolRefExpr::VK_PPC_LO:
115 Type = ELF::R_PPC_ADDR16_LO;
116 break;
117 case MCSymbolRefExpr::VK_PPC_HI:
118 Type = ELF::R_PPC_ADDR16_HI;
119 break;
120 case MCSymbolRefExpr::VK_PPC_HA:
121 Type = ELF::R_PPC_ADDR16_HA;
122 break;
123 case MCSymbolRefExpr::VK_PPC_HIGHER:
124 Type = ELF::R_PPC64_ADDR16_HIGHER;
125 break;
126 case MCSymbolRefExpr::VK_PPC_HIGHERA:
127 Type = ELF::R_PPC64_ADDR16_HIGHERA;
128 break;
129 case MCSymbolRefExpr::VK_PPC_HIGHEST:
130 Type = ELF::R_PPC64_ADDR16_HIGHEST;
131 break;
132 case MCSymbolRefExpr::VK_PPC_HIGHESTA:
133 Type = ELF::R_PPC64_ADDR16_HIGHESTA;
134 break;
135 case MCSymbolRefExpr::VK_GOT:
136 Type = ELF::R_PPC_GOT16;
137 break;
138 case MCSymbolRefExpr::VK_PPC_GOT_LO:
139 Type = ELF::R_PPC_GOT16_LO;
140 break;
141 case MCSymbolRefExpr::VK_PPC_GOT_HI:
142 Type = ELF::R_PPC_GOT16_HI;
143 break;
144 case MCSymbolRefExpr::VK_PPC_GOT_HA:
145 Type = ELF::R_PPC_GOT16_HA;
146 break;
147 case MCSymbolRefExpr::VK_PPC_TOC:
148 Type = ELF::R_PPC64_TOC16;
149 break;
150 case MCSymbolRefExpr::VK_PPC_TOC_LO:
151 Type = ELF::R_PPC64_TOC16_LO;
152 break;
153 case MCSymbolRefExpr::VK_PPC_TOC_HI:
154 Type = ELF::R_PPC64_TOC16_HI;
155 break;
156 case MCSymbolRefExpr::VK_PPC_TOC_HA:
157 Type = ELF::R_PPC64_TOC16_HA;
158 break;
159 case MCSymbolRefExpr::VK_PPC_TPREL:
160 Type = ELF::R_PPC_TPREL16;
161 break;
162 case MCSymbolRefExpr::VK_PPC_TPREL_LO:
163 Type = ELF::R_PPC_TPREL16_LO;
164 break;
165 case MCSymbolRefExpr::VK_PPC_TPREL_HI:
166 Type = ELF::R_PPC_TPREL16_HI;
167 break;
168 case MCSymbolRefExpr::VK_PPC_TPREL_HA:
169 Type = ELF::R_PPC_TPREL16_HA;
170 break;
171 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHER:
172 Type = ELF::R_PPC64_TPREL16_HIGHER;
173 break;
174 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHERA:
175 Type = ELF::R_PPC64_TPREL16_HIGHERA;
176 break;
177 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHEST:
178 Type = ELF::R_PPC64_TPREL16_HIGHEST;
179 break;
180 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHESTA:
181 Type = ELF::R_PPC64_TPREL16_HIGHESTA;
182 break;
183 case MCSymbolRefExpr::VK_PPC_DTPREL:
184 Type = ELF::R_PPC64_DTPREL16;
185 break;
186 case MCSymbolRefExpr::VK_PPC_DTPREL_LO:
187 Type = ELF::R_PPC64_DTPREL16_LO;
188 break;
189 case MCSymbolRefExpr::VK_PPC_DTPREL_HI:
190 Type = ELF::R_PPC64_DTPREL16_HI;
191 break;
192 case MCSymbolRefExpr::VK_PPC_DTPREL_HA:
193 Type = ELF::R_PPC64_DTPREL16_HA;
194 break;
195 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHER:
196 Type = ELF::R_PPC64_DTPREL16_HIGHER;
197 break;
198 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHERA:
199 Type = ELF::R_PPC64_DTPREL16_HIGHERA;
200 break;
201 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHEST:
202 Type = ELF::R_PPC64_DTPREL16_HIGHEST;
203 break;
204 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHESTA:
205 Type = ELF::R_PPC64_DTPREL16_HIGHESTA;
206 break;
207 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD:
208 Type = ELF::R_PPC64_GOT_TLSGD16;
209 break;
210 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO:
211 Type = ELF::R_PPC64_GOT_TLSGD16_LO;
212 break;
213 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HI:
214 Type = ELF::R_PPC64_GOT_TLSGD16_HI;
215 break;
216 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA:
217 Type = ELF::R_PPC64_GOT_TLSGD16_HA;
218 break;
219 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD:
220 Type = ELF::R_PPC64_GOT_TLSLD16;
221 break;
222 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO:
223 Type = ELF::R_PPC64_GOT_TLSLD16_LO;
224 break;
225 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HI:
226 Type = ELF::R_PPC64_GOT_TLSLD16_HI;
227 break;
228 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA:
229 Type = ELF::R_PPC64_GOT_TLSLD16_HA;
230 break;
231 case MCSymbolRefExpr::VK_PPC_GOT_TPREL:
232 /* We don't have R_PPC64_GOT_TPREL16, but since GOT offsets
233 are always 4-aligned, we can use R_PPC64_GOT_TPREL16_DS. */
234 Type = ELF::R_PPC64_GOT_TPREL16_DS;
235 break;
236 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO:
237 /* We don't have R_PPC64_GOT_TPREL16_LO, but since GOT offsets
238 are always 4-aligned, we can use R_PPC64_GOT_TPREL16_LO_DS. */
239 Type = ELF::R_PPC64_GOT_TPREL16_LO_DS;
240 break;
241 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HI:
242 Type = ELF::R_PPC64_GOT_TPREL16_HI;
243 break;
244 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL:
245 /* We don't have R_PPC64_GOT_DTPREL16, but since GOT offsets
246 are always 4-aligned, we can use R_PPC64_GOT_DTPREL16_DS. */
247 Type = ELF::R_PPC64_GOT_DTPREL16_DS;
248 break;
249 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO:
250 /* We don't have R_PPC64_GOT_DTPREL16_LO, but since GOT offsets
251 are always 4-aligned, we can use R_PPC64_GOT_DTPREL16_LO_DS. */
252 Type = ELF::R_PPC64_GOT_DTPREL16_LO_DS;
253 break;
254 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA:
255 Type = ELF::R_PPC64_GOT_TPREL16_HA;
256 break;
257 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HI:
258 Type = ELF::R_PPC64_GOT_DTPREL16_HI;
259 break;
260 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HA:
261 Type = ELF::R_PPC64_GOT_DTPREL16_HA;
262 break;
263 }
264 break;
265 case PPC::fixup_ppc_half16ds:
266 switch (Modifier) {
267 default: llvm_unreachable("Unsupported Modifier");
268 case MCSymbolRefExpr::VK_None:
269 Type = ELF::R_PPC64_ADDR16_DS;
270 break;
271 case MCSymbolRefExpr::VK_PPC_LO:
272 Type = ELF::R_PPC64_ADDR16_LO_DS;
273 break;
274 case MCSymbolRefExpr::VK_GOT:
275 Type = ELF::R_PPC64_GOT16_DS;
276 break;
277 case MCSymbolRefExpr::VK_PPC_GOT_LO:
278 Type = ELF::R_PPC64_GOT16_LO_DS;
279 break;
280 case MCSymbolRefExpr::VK_PPC_TOC:
281 Type = ELF::R_PPC64_TOC16_DS;
282 break;
283 case MCSymbolRefExpr::VK_PPC_TOC_LO:
284 Type = ELF::R_PPC64_TOC16_LO_DS;
285 break;
286 case MCSymbolRefExpr::VK_PPC_TPREL:
287 Type = ELF::R_PPC64_TPREL16_DS;
288 break;
289 case MCSymbolRefExpr::VK_PPC_TPREL_LO:
290 Type = ELF::R_PPC64_TPREL16_LO_DS;
291 break;
292 case MCSymbolRefExpr::VK_PPC_DTPREL:
293 Type = ELF::R_PPC64_DTPREL16_DS;
294 break;
295 case MCSymbolRefExpr::VK_PPC_DTPREL_LO:
296 Type = ELF::R_PPC64_DTPREL16_LO_DS;
297 break;
298 case MCSymbolRefExpr::VK_PPC_GOT_TPREL:
299 Type = ELF::R_PPC64_GOT_TPREL16_DS;
300 break;
301 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO:
302 Type = ELF::R_PPC64_GOT_TPREL16_LO_DS;
303 break;
304 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL:
305 Type = ELF::R_PPC64_GOT_DTPREL16_DS;
306 break;
307 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO:
308 Type = ELF::R_PPC64_GOT_DTPREL16_LO_DS;
309 break;
310 }
311 break;
312 case PPC::fixup_ppc_nofixup:
313 switch (Modifier) {
314 default: llvm_unreachable("Unsupported Modifier");
315 case MCSymbolRefExpr::VK_PPC_TLSGD:
316 Type = ELF::R_PPC64_TLSGD;
317 break;
318 case MCSymbolRefExpr::VK_PPC_TLSLD:
319 Type = ELF::R_PPC64_TLSLD;
320 break;
321 case MCSymbolRefExpr::VK_PPC_TLS:
322 Type = ELF::R_PPC64_TLS;
323 break;
324 }
325 break;
326 case FK_Data_8:
327 switch (Modifier) {
328 default: llvm_unreachable("Unsupported Modifier");
329 case MCSymbolRefExpr::VK_PPC_TOCBASE:
330 Type = ELF::R_PPC64_TOC;
331 break;
332 case MCSymbolRefExpr::VK_None:
333 Type = ELF::R_PPC64_ADDR64;
334 break;
335 case MCSymbolRefExpr::VK_PPC_DTPMOD:
336 Type = ELF::R_PPC64_DTPMOD64;
337 break;
338 case MCSymbolRefExpr::VK_PPC_TPREL:
339 Type = ELF::R_PPC64_TPREL64;
340 break;
341 case MCSymbolRefExpr::VK_PPC_DTPREL:
342 Type = ELF::R_PPC64_DTPREL64;
343 break;
344 }
345 break;
346 case FK_Data_4:
347 Type = ELF::R_PPC_ADDR32;
348 break;
349 case FK_Data_2:
350 Type = ELF::R_PPC_ADDR16;
351 break;
352 }
353 }
354 return Type;
355 }
356
GetRelocType(const MCValue & Target,const MCFixup & Fixup,bool IsPCRel,bool IsRelocWithSymbol,int64_t Addend) const357 unsigned PPCELFObjectWriter::GetRelocType(const MCValue &Target,
358 const MCFixup &Fixup,
359 bool IsPCRel,
360 bool IsRelocWithSymbol,
361 int64_t Addend) const {
362 return getRelocTypeInner(Target, Fixup, IsPCRel);
363 }
364
ExplicitRelSym(const MCAssembler & Asm,const MCValue & Target,const MCFragment & F,const MCFixup & Fixup,bool IsPCRel) const365 const MCSymbol *PPCELFObjectWriter::ExplicitRelSym(const MCAssembler &Asm,
366 const MCValue &Target,
367 const MCFragment &F,
368 const MCFixup &Fixup,
369 bool IsPCRel) const {
370 assert(Target.getSymA() && "SymA cannot be 0");
371 MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ?
372 MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
373
374 bool EmitThisSym;
375 switch (Modifier) {
376 // GOT references always need a relocation, even if the
377 // target symbol is local.
378 case MCSymbolRefExpr::VK_GOT:
379 case MCSymbolRefExpr::VK_PPC_GOT_LO:
380 case MCSymbolRefExpr::VK_PPC_GOT_HI:
381 case MCSymbolRefExpr::VK_PPC_GOT_HA:
382 EmitThisSym = true;
383 break;
384 default:
385 EmitThisSym = false;
386 break;
387 }
388
389 if (EmitThisSym)
390 return &Target.getSymA()->getSymbol().AliasedSymbol();
391 return NULL;
392 }
393
undefinedExplicitRelSym(const MCValue & Target,const MCFixup & Fixup,bool IsPCRel) const394 const MCSymbol *PPCELFObjectWriter::undefinedExplicitRelSym(const MCValue &Target,
395 const MCFixup &Fixup,
396 bool IsPCRel) const {
397 assert(Target.getSymA() && "SymA cannot be 0");
398 const MCSymbol &Symbol = Target.getSymA()->getSymbol().AliasedSymbol();
399
400 unsigned RelocType = getRelocTypeInner(Target, Fixup, IsPCRel);
401
402 // The .odp creation emits a relocation against the symbol ".TOC." which
403 // create a R_PPC64_TOC relocation. However the relocation symbol name
404 // in final object creation should be NULL, since the symbol does not
405 // really exist, it is just the reference to TOC base for the current
406 // object file.
407 bool EmitThisSym = RelocType != ELF::R_PPC64_TOC;
408
409 if (EmitThisSym && !Symbol.isTemporary())
410 return &Symbol;
411 return NULL;
412 }
413
createPPCELFObjectWriter(raw_ostream & OS,bool Is64Bit,uint8_t OSABI)414 MCObjectWriter *llvm::createPPCELFObjectWriter(raw_ostream &OS,
415 bool Is64Bit,
416 uint8_t OSABI) {
417 MCELFObjectTargetWriter *MOTW = new PPCELFObjectWriter(Is64Bit, OSABI);
418 return createELFObjectWriter(MOTW, OS, /*IsLittleEndian=*/false);
419 }
420