1 //===-- MObjectFileInfo.cpp - Object File Information ---------------------===// 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/MCObjectFileInfo.h" 11 #include "llvm/MC/MCContext.h" 12 #include "llvm/MC/MCSection.h" 13 #include "llvm/MC/MCSectionCOFF.h" 14 #include "llvm/MC/MCSectionELF.h" 15 #include "llvm/MC/MCSectionMachO.h" 16 #include "llvm/ADT/Triple.h" 17 using namespace llvm; 18 19 void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) { 20 // MachO 21 IsFunctionEHFrameSymbolPrivate = false; 22 SupportsWeakOmittedEHFrame = false; 23 24 // .comm doesn't support alignment before Leopard. 25 if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5)) 26 CommDirectiveSupportsAlignment = false; 27 28 TextSection // .text 29 = Ctx->getMachOSection("__TEXT", "__text", 30 MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS, 31 SectionKind::getText()); 32 DataSection // .data 33 = Ctx->getMachOSection("__DATA", "__data", 0, 34 SectionKind::getDataRel()); 35 36 TLSDataSection // .tdata 37 = Ctx->getMachOSection("__DATA", "__thread_data", 38 MCSectionMachO::S_THREAD_LOCAL_REGULAR, 39 SectionKind::getDataRel()); 40 TLSBSSSection // .tbss 41 = Ctx->getMachOSection("__DATA", "__thread_bss", 42 MCSectionMachO::S_THREAD_LOCAL_ZEROFILL, 43 SectionKind::getThreadBSS()); 44 45 // TODO: Verify datarel below. 46 TLSTLVSection // .tlv 47 = Ctx->getMachOSection("__DATA", "__thread_vars", 48 MCSectionMachO::S_THREAD_LOCAL_VARIABLES, 49 SectionKind::getDataRel()); 50 51 TLSThreadInitSection 52 = Ctx->getMachOSection("__DATA", "__thread_init", 53 MCSectionMachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS, 54 SectionKind::getDataRel()); 55 56 CStringSection // .cstring 57 = Ctx->getMachOSection("__TEXT", "__cstring", 58 MCSectionMachO::S_CSTRING_LITERALS, 59 SectionKind::getMergeable1ByteCString()); 60 UStringSection 61 = Ctx->getMachOSection("__TEXT","__ustring", 0, 62 SectionKind::getMergeable2ByteCString()); 63 FourByteConstantSection // .literal4 64 = Ctx->getMachOSection("__TEXT", "__literal4", 65 MCSectionMachO::S_4BYTE_LITERALS, 66 SectionKind::getMergeableConst4()); 67 EightByteConstantSection // .literal8 68 = Ctx->getMachOSection("__TEXT", "__literal8", 69 MCSectionMachO::S_8BYTE_LITERALS, 70 SectionKind::getMergeableConst8()); 71 72 // ld_classic doesn't support .literal16 in 32-bit mode, and ld64 falls back 73 // to using it in -static mode. 74 SixteenByteConstantSection = 0; 75 if (RelocM != Reloc::Static && 76 T.getArch() != Triple::x86_64 && T.getArch() != Triple::ppc64) 77 SixteenByteConstantSection = // .literal16 78 Ctx->getMachOSection("__TEXT", "__literal16", 79 MCSectionMachO::S_16BYTE_LITERALS, 80 SectionKind::getMergeableConst16()); 81 82 ReadOnlySection // .const 83 = Ctx->getMachOSection("__TEXT", "__const", 0, 84 SectionKind::getReadOnly()); 85 86 TextCoalSection 87 = Ctx->getMachOSection("__TEXT", "__textcoal_nt", 88 MCSectionMachO::S_COALESCED | 89 MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS, 90 SectionKind::getText()); 91 ConstTextCoalSection 92 = Ctx->getMachOSection("__TEXT", "__const_coal", 93 MCSectionMachO::S_COALESCED, 94 SectionKind::getReadOnly()); 95 ConstDataSection // .const_data 96 = Ctx->getMachOSection("__DATA", "__const", 0, 97 SectionKind::getReadOnlyWithRel()); 98 DataCoalSection 99 = Ctx->getMachOSection("__DATA","__datacoal_nt", 100 MCSectionMachO::S_COALESCED, 101 SectionKind::getDataRel()); 102 DataCommonSection 103 = Ctx->getMachOSection("__DATA","__common", 104 MCSectionMachO::S_ZEROFILL, 105 SectionKind::getBSS()); 106 DataBSSSection 107 = Ctx->getMachOSection("__DATA","__bss", MCSectionMachO::S_ZEROFILL, 108 SectionKind::getBSS()); 109 110 111 LazySymbolPointerSection 112 = Ctx->getMachOSection("__DATA", "__la_symbol_ptr", 113 MCSectionMachO::S_LAZY_SYMBOL_POINTERS, 114 SectionKind::getMetadata()); 115 NonLazySymbolPointerSection 116 = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr", 117 MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS, 118 SectionKind::getMetadata()); 119 120 if (RelocM == Reloc::Static) { 121 StaticCtorSection 122 = Ctx->getMachOSection("__TEXT", "__constructor", 0, 123 SectionKind::getDataRel()); 124 StaticDtorSection 125 = Ctx->getMachOSection("__TEXT", "__destructor", 0, 126 SectionKind::getDataRel()); 127 } else { 128 StaticCtorSection 129 = Ctx->getMachOSection("__DATA", "__mod_init_func", 130 MCSectionMachO::S_MOD_INIT_FUNC_POINTERS, 131 SectionKind::getDataRel()); 132 StaticDtorSection 133 = Ctx->getMachOSection("__DATA", "__mod_term_func", 134 MCSectionMachO::S_MOD_TERM_FUNC_POINTERS, 135 SectionKind::getDataRel()); 136 } 137 138 // Exception Handling. 139 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0, 140 SectionKind::getReadOnlyWithRel()); 141 142 if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) 143 CompactUnwindSection = 144 Ctx->getMachOSection("__LD", "__compact_unwind", 145 MCSectionMachO::S_ATTR_DEBUG, 146 SectionKind::getReadOnly()); 147 148 // Debug Information. 149 DwarfAbbrevSection = 150 Ctx->getMachOSection("__DWARF", "__debug_abbrev", 151 MCSectionMachO::S_ATTR_DEBUG, 152 SectionKind::getMetadata()); 153 DwarfInfoSection = 154 Ctx->getMachOSection("__DWARF", "__debug_info", 155 MCSectionMachO::S_ATTR_DEBUG, 156 SectionKind::getMetadata()); 157 DwarfLineSection = 158 Ctx->getMachOSection("__DWARF", "__debug_line", 159 MCSectionMachO::S_ATTR_DEBUG, 160 SectionKind::getMetadata()); 161 DwarfFrameSection = 162 Ctx->getMachOSection("__DWARF", "__debug_frame", 163 MCSectionMachO::S_ATTR_DEBUG, 164 SectionKind::getMetadata()); 165 DwarfPubNamesSection = 166 Ctx->getMachOSection("__DWARF", "__debug_pubnames", 167 MCSectionMachO::S_ATTR_DEBUG, 168 SectionKind::getMetadata()); 169 DwarfPubTypesSection = 170 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", 171 MCSectionMachO::S_ATTR_DEBUG, 172 SectionKind::getMetadata()); 173 DwarfStrSection = 174 Ctx->getMachOSection("__DWARF", "__debug_str", 175 MCSectionMachO::S_ATTR_DEBUG, 176 SectionKind::getMetadata()); 177 DwarfLocSection = 178 Ctx->getMachOSection("__DWARF", "__debug_loc", 179 MCSectionMachO::S_ATTR_DEBUG, 180 SectionKind::getMetadata()); 181 DwarfARangesSection = 182 Ctx->getMachOSection("__DWARF", "__debug_aranges", 183 MCSectionMachO::S_ATTR_DEBUG, 184 SectionKind::getMetadata()); 185 DwarfRangesSection = 186 Ctx->getMachOSection("__DWARF", "__debug_ranges", 187 MCSectionMachO::S_ATTR_DEBUG, 188 SectionKind::getMetadata()); 189 DwarfMacroInfoSection = 190 Ctx->getMachOSection("__DWARF", "__debug_macinfo", 191 MCSectionMachO::S_ATTR_DEBUG, 192 SectionKind::getMetadata()); 193 DwarfDebugInlineSection = 194 Ctx->getMachOSection("__DWARF", "__debug_inlined", 195 MCSectionMachO::S_ATTR_DEBUG, 196 SectionKind::getMetadata()); 197 198 TLSExtraDataSection = TLSTLVSection; 199 } 200 201 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) { 202 // ELF 203 BSSSection = 204 Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 205 ELF::SHF_WRITE |ELF::SHF_ALLOC, 206 SectionKind::getBSS()); 207 208 TextSection = 209 Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 210 ELF::SHF_EXECINSTR | 211 ELF::SHF_ALLOC, 212 SectionKind::getText()); 213 214 DataSection = 215 Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 216 ELF::SHF_WRITE |ELF::SHF_ALLOC, 217 SectionKind::getDataRel()); 218 219 ReadOnlySection = 220 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, 221 ELF::SHF_ALLOC, 222 SectionKind::getReadOnly()); 223 224 TLSDataSection = 225 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 226 ELF::SHF_ALLOC | ELF::SHF_TLS | 227 ELF::SHF_WRITE, 228 SectionKind::getThreadData()); 229 230 TLSBSSSection = 231 Ctx->getELFSection(".tbss", ELF::SHT_NOBITS, 232 ELF::SHF_ALLOC | ELF::SHF_TLS | 233 ELF::SHF_WRITE, 234 SectionKind::getThreadBSS()); 235 236 DataRelSection = 237 Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS, 238 ELF::SHF_ALLOC |ELF::SHF_WRITE, 239 SectionKind::getDataRel()); 240 241 DataRelLocalSection = 242 Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS, 243 ELF::SHF_ALLOC |ELF::SHF_WRITE, 244 SectionKind::getDataRelLocal()); 245 246 DataRelROSection = 247 Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 248 ELF::SHF_ALLOC |ELF::SHF_WRITE, 249 SectionKind::getReadOnlyWithRel()); 250 251 DataRelROLocalSection = 252 Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS, 253 ELF::SHF_ALLOC |ELF::SHF_WRITE, 254 SectionKind::getReadOnlyWithRelLocal()); 255 256 MergeableConst4Section = 257 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 258 ELF::SHF_ALLOC |ELF::SHF_MERGE, 259 SectionKind::getMergeableConst4()); 260 261 MergeableConst8Section = 262 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 263 ELF::SHF_ALLOC |ELF::SHF_MERGE, 264 SectionKind::getMergeableConst8()); 265 266 MergeableConst16Section = 267 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 268 ELF::SHF_ALLOC |ELF::SHF_MERGE, 269 SectionKind::getMergeableConst16()); 270 271 StaticCtorSection = 272 Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS, 273 ELF::SHF_ALLOC |ELF::SHF_WRITE, 274 SectionKind::getDataRel()); 275 276 StaticDtorSection = 277 Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS, 278 ELF::SHF_ALLOC |ELF::SHF_WRITE, 279 SectionKind::getDataRel()); 280 281 // Exception Handling Sections. 282 283 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 284 // it contains relocatable pointers. In PIC mode, this is probably a big 285 // runtime hit for C++ apps. Either the contents of the LSDA need to be 286 // adjusted or this should be a data section. 287 LSDASection = 288 Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 289 ELF::SHF_ALLOC, 290 SectionKind::getReadOnly()); 291 292 // Debug Info Sections. 293 DwarfAbbrevSection = 294 Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0, 295 SectionKind::getMetadata()); 296 DwarfInfoSection = 297 Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, 298 SectionKind::getMetadata()); 299 DwarfLineSection = 300 Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0, 301 SectionKind::getMetadata()); 302 DwarfFrameSection = 303 Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0, 304 SectionKind::getMetadata()); 305 DwarfPubNamesSection = 306 Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0, 307 SectionKind::getMetadata()); 308 DwarfPubTypesSection = 309 Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0, 310 SectionKind::getMetadata()); 311 DwarfStrSection = 312 Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS, 0, 313 SectionKind::getMetadata()); 314 DwarfLocSection = 315 Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0, 316 SectionKind::getMetadata()); 317 DwarfARangesSection = 318 Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0, 319 SectionKind::getMetadata()); 320 DwarfRangesSection = 321 Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, 322 SectionKind::getMetadata()); 323 DwarfMacroInfoSection = 324 Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0, 325 SectionKind::getMetadata()); 326 } 327 328 329 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) { 330 // COFF 331 TextSection = 332 Ctx->getCOFFSection(".text", 333 COFF::IMAGE_SCN_CNT_CODE | 334 COFF::IMAGE_SCN_MEM_EXECUTE | 335 COFF::IMAGE_SCN_MEM_READ, 336 SectionKind::getText()); 337 DataSection = 338 Ctx->getCOFFSection(".data", 339 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 340 COFF::IMAGE_SCN_MEM_READ | 341 COFF::IMAGE_SCN_MEM_WRITE, 342 SectionKind::getDataRel()); 343 ReadOnlySection = 344 Ctx->getCOFFSection(".rdata", 345 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 346 COFF::IMAGE_SCN_MEM_READ, 347 SectionKind::getReadOnly()); 348 StaticCtorSection = 349 Ctx->getCOFFSection(".ctors", 350 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 351 COFF::IMAGE_SCN_MEM_READ | 352 COFF::IMAGE_SCN_MEM_WRITE, 353 SectionKind::getDataRel()); 354 StaticDtorSection = 355 Ctx->getCOFFSection(".dtors", 356 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 357 COFF::IMAGE_SCN_MEM_READ | 358 COFF::IMAGE_SCN_MEM_WRITE, 359 SectionKind::getDataRel()); 360 361 // FIXME: We're emitting LSDA info into a readonly section on COFF, even 362 // though it contains relocatable pointers. In PIC mode, this is probably a 363 // big runtime hit for C++ apps. Either the contents of the LSDA need to be 364 // adjusted or this should be a data section. 365 LSDASection = 366 Ctx->getCOFFSection(".gcc_except_table", 367 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 368 COFF::IMAGE_SCN_MEM_READ, 369 SectionKind::getReadOnly()); 370 371 // Debug info. 372 DwarfAbbrevSection = 373 Ctx->getCOFFSection(".debug_abbrev", 374 COFF::IMAGE_SCN_MEM_DISCARDABLE | 375 COFF::IMAGE_SCN_MEM_READ, 376 SectionKind::getMetadata()); 377 DwarfInfoSection = 378 Ctx->getCOFFSection(".debug_info", 379 COFF::IMAGE_SCN_MEM_DISCARDABLE | 380 COFF::IMAGE_SCN_MEM_READ, 381 SectionKind::getMetadata()); 382 DwarfLineSection = 383 Ctx->getCOFFSection(".debug_line", 384 COFF::IMAGE_SCN_MEM_DISCARDABLE | 385 COFF::IMAGE_SCN_MEM_READ, 386 SectionKind::getMetadata()); 387 DwarfFrameSection = 388 Ctx->getCOFFSection(".debug_frame", 389 COFF::IMAGE_SCN_MEM_DISCARDABLE | 390 COFF::IMAGE_SCN_MEM_READ, 391 SectionKind::getMetadata()); 392 DwarfPubNamesSection = 393 Ctx->getCOFFSection(".debug_pubnames", 394 COFF::IMAGE_SCN_MEM_DISCARDABLE | 395 COFF::IMAGE_SCN_MEM_READ, 396 SectionKind::getMetadata()); 397 DwarfPubTypesSection = 398 Ctx->getCOFFSection(".debug_pubtypes", 399 COFF::IMAGE_SCN_MEM_DISCARDABLE | 400 COFF::IMAGE_SCN_MEM_READ, 401 SectionKind::getMetadata()); 402 DwarfStrSection = 403 Ctx->getCOFFSection(".debug_str", 404 COFF::IMAGE_SCN_MEM_DISCARDABLE | 405 COFF::IMAGE_SCN_MEM_READ, 406 SectionKind::getMetadata()); 407 DwarfLocSection = 408 Ctx->getCOFFSection(".debug_loc", 409 COFF::IMAGE_SCN_MEM_DISCARDABLE | 410 COFF::IMAGE_SCN_MEM_READ, 411 SectionKind::getMetadata()); 412 DwarfARangesSection = 413 Ctx->getCOFFSection(".debug_aranges", 414 COFF::IMAGE_SCN_MEM_DISCARDABLE | 415 COFF::IMAGE_SCN_MEM_READ, 416 SectionKind::getMetadata()); 417 DwarfRangesSection = 418 Ctx->getCOFFSection(".debug_ranges", 419 COFF::IMAGE_SCN_MEM_DISCARDABLE | 420 COFF::IMAGE_SCN_MEM_READ, 421 SectionKind::getMetadata()); 422 DwarfMacroInfoSection = 423 Ctx->getCOFFSection(".debug_macinfo", 424 COFF::IMAGE_SCN_MEM_DISCARDABLE | 425 COFF::IMAGE_SCN_MEM_READ, 426 SectionKind::getMetadata()); 427 428 DrectveSection = 429 Ctx->getCOFFSection(".drectve", 430 COFF::IMAGE_SCN_LNK_INFO, 431 SectionKind::getMetadata()); 432 433 PDataSection = 434 Ctx->getCOFFSection(".pdata", 435 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 436 COFF::IMAGE_SCN_MEM_READ | 437 COFF::IMAGE_SCN_MEM_WRITE, 438 SectionKind::getDataRel()); 439 440 XDataSection = 441 Ctx->getCOFFSection(".xdata", 442 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 443 COFF::IMAGE_SCN_MEM_READ | 444 COFF::IMAGE_SCN_MEM_WRITE, 445 SectionKind::getDataRel()); 446 } 447 448 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm, 449 MCContext &ctx) { 450 RelocM = relocm; 451 Ctx = &ctx; 452 453 // Common. 454 CommDirectiveSupportsAlignment = true; 455 SupportsWeakOmittedEHFrame = true; 456 IsFunctionEHFrameSymbolPrivate = true; 457 458 Triple T(TT); 459 Triple::ArchType Arch = T.getArch(); 460 // FIXME: Checking for Arch here to filter out bogus triples such as 461 // cellspu-apple-darwin. Perhaps we should fix in Triple? 462 if ((Arch == Triple::x86 || Arch == Triple::x86_64 || 463 Arch == Triple::arm || Arch == Triple::thumb || 464 Arch == Triple::ppc || Arch == Triple::ppc64 || 465 Arch == Triple::UnknownArch) && 466 (T.isOSDarwin() || T.getEnvironment() == Triple::MachO)) { 467 Env = IsMachO; 468 InitMachOMCObjectFileInfo(T); 469 } else if (T.getOS() == Triple::MinGW32 || T.getOS() == Triple::Cygwin || 470 T.getOS() == Triple::Win32) { 471 Env = IsCOFF; 472 InitCOFFMCObjectFileInfo(T); 473 } else { 474 Env = IsELF; 475 InitELFMCObjectFileInfo(T); 476 } 477 } 478 479 void MCObjectFileInfo::InitEHFrameSection() { 480 if (Env == IsMachO) 481 EHFrameSection = 482 Ctx->getMachOSection("__TEXT", "__eh_frame", 483 MCSectionMachO::S_COALESCED | 484 MCSectionMachO::S_ATTR_NO_TOC | 485 MCSectionMachO::S_ATTR_STRIP_STATIC_SYMS | 486 MCSectionMachO::S_ATTR_LIVE_SUPPORT, 487 SectionKind::getReadOnly()); 488 else if (Env == IsELF) 489 EHFrameSection = 490 Ctx->getELFSection(".eh_frame", ELF::SHT_PROGBITS, 491 ELF::SHF_ALLOC, 492 SectionKind::getDataRel()); 493 else 494 EHFrameSection = 495 Ctx->getCOFFSection(".eh_frame", 496 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 497 COFF::IMAGE_SCN_MEM_READ | 498 COFF::IMAGE_SCN_MEM_WRITE, 499 SectionKind::getDataRel()); 500 } 501
