1 //===-- MCObjectFileInfo.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/ADT/StringExtras.h" 12 #include "llvm/ADT/Triple.h" 13 #include "llvm/BinaryFormat/COFF.h" 14 #include "llvm/BinaryFormat/ELF.h" 15 #include "llvm/MC/MCAsmInfo.h" 16 #include "llvm/MC/MCContext.h" 17 #include "llvm/MC/MCSection.h" 18 #include "llvm/MC/MCSectionCOFF.h" 19 #include "llvm/MC/MCSectionELF.h" 20 #include "llvm/MC/MCSectionMachO.h" 21 #include "llvm/MC/MCSectionWasm.h" 22 23 using namespace llvm; 24 25 static bool useCompactUnwind(const Triple &T) { 26 // Only on darwin. 27 if (!T.isOSDarwin()) 28 return false; 29 30 // aarch64 always has it. 31 if (T.getArch() == Triple::aarch64) 32 return true; 33 34 // armv7k always has it. 35 if (T.isWatchABI()) 36 return true; 37 38 // Use it on newer version of OS X. 39 if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) 40 return true; 41 42 // And the iOS simulator. 43 if (T.isiOS() && 44 (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)) 45 return true; 46 47 return false; 48 } 49 50 void MCObjectFileInfo::initMachOMCObjectFileInfo(const Triple &T) { 51 // MachO 52 SupportsWeakOmittedEHFrame = false; 53 54 EHFrameSection = Ctx->getMachOSection( 55 "__TEXT", "__eh_frame", 56 MachO::S_COALESCED | MachO::S_ATTR_NO_TOC | 57 MachO::S_ATTR_STRIP_STATIC_SYMS | MachO::S_ATTR_LIVE_SUPPORT, 58 SectionKind::getReadOnly()); 59 60 if (T.isOSDarwin() && T.getArch() == Triple::aarch64) 61 SupportsCompactUnwindWithoutEHFrame = true; 62 63 if (T.isWatchABI()) 64 OmitDwarfIfHaveCompactUnwind = true; 65 66 FDECFIEncoding = dwarf::DW_EH_PE_pcrel; 67 68 // .comm doesn't support alignment before Leopard. 69 if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5)) 70 CommDirectiveSupportsAlignment = false; 71 72 TextSection // .text 73 = Ctx->getMachOSection("__TEXT", "__text", 74 MachO::S_ATTR_PURE_INSTRUCTIONS, 75 SectionKind::getText()); 76 DataSection // .data 77 = Ctx->getMachOSection("__DATA", "__data", 0, SectionKind::getData()); 78 79 // BSSSection might not be expected initialized on msvc. 80 BSSSection = nullptr; 81 82 TLSDataSection // .tdata 83 = Ctx->getMachOSection("__DATA", "__thread_data", 84 MachO::S_THREAD_LOCAL_REGULAR, 85 SectionKind::getData()); 86 TLSBSSSection // .tbss 87 = Ctx->getMachOSection("__DATA", "__thread_bss", 88 MachO::S_THREAD_LOCAL_ZEROFILL, 89 SectionKind::getThreadBSS()); 90 91 // TODO: Verify datarel below. 92 TLSTLVSection // .tlv 93 = Ctx->getMachOSection("__DATA", "__thread_vars", 94 MachO::S_THREAD_LOCAL_VARIABLES, 95 SectionKind::getData()); 96 97 TLSThreadInitSection = Ctx->getMachOSection( 98 "__DATA", "__thread_init", MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS, 99 SectionKind::getData()); 100 101 CStringSection // .cstring 102 = Ctx->getMachOSection("__TEXT", "__cstring", 103 MachO::S_CSTRING_LITERALS, 104 SectionKind::getMergeable1ByteCString()); 105 UStringSection 106 = Ctx->getMachOSection("__TEXT","__ustring", 0, 107 SectionKind::getMergeable2ByteCString()); 108 FourByteConstantSection // .literal4 109 = Ctx->getMachOSection("__TEXT", "__literal4", 110 MachO::S_4BYTE_LITERALS, 111 SectionKind::getMergeableConst4()); 112 EightByteConstantSection // .literal8 113 = Ctx->getMachOSection("__TEXT", "__literal8", 114 MachO::S_8BYTE_LITERALS, 115 SectionKind::getMergeableConst8()); 116 117 SixteenByteConstantSection // .literal16 118 = Ctx->getMachOSection("__TEXT", "__literal16", 119 MachO::S_16BYTE_LITERALS, 120 SectionKind::getMergeableConst16()); 121 122 ReadOnlySection // .const 123 = Ctx->getMachOSection("__TEXT", "__const", 0, 124 SectionKind::getReadOnly()); 125 126 // If the target is not powerpc, map the coal sections to the non-coal 127 // sections. 128 // 129 // "__TEXT/__textcoal_nt" => section "__TEXT/__text" 130 // "__TEXT/__const_coal" => section "__TEXT/__const" 131 // "__DATA/__datacoal_nt" => section "__DATA/__data" 132 Triple::ArchType ArchTy = T.getArch(); 133 134 ConstDataSection // .const_data 135 = Ctx->getMachOSection("__DATA", "__const", 0, 136 SectionKind::getReadOnlyWithRel()); 137 138 if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) { 139 TextCoalSection 140 = Ctx->getMachOSection("__TEXT", "__textcoal_nt", 141 MachO::S_COALESCED | 142 MachO::S_ATTR_PURE_INSTRUCTIONS, 143 SectionKind::getText()); 144 ConstTextCoalSection 145 = Ctx->getMachOSection("__TEXT", "__const_coal", 146 MachO::S_COALESCED, 147 SectionKind::getReadOnly()); 148 DataCoalSection = Ctx->getMachOSection( 149 "__DATA", "__datacoal_nt", MachO::S_COALESCED, SectionKind::getData()); 150 ConstDataCoalSection = DataCoalSection; 151 } else { 152 TextCoalSection = TextSection; 153 ConstTextCoalSection = ReadOnlySection; 154 DataCoalSection = DataSection; 155 ConstDataCoalSection = ConstDataSection; 156 } 157 158 DataCommonSection 159 = Ctx->getMachOSection("__DATA","__common", 160 MachO::S_ZEROFILL, 161 SectionKind::getBSS()); 162 DataBSSSection 163 = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL, 164 SectionKind::getBSS()); 165 166 167 LazySymbolPointerSection 168 = Ctx->getMachOSection("__DATA", "__la_symbol_ptr", 169 MachO::S_LAZY_SYMBOL_POINTERS, 170 SectionKind::getMetadata()); 171 NonLazySymbolPointerSection 172 = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr", 173 MachO::S_NON_LAZY_SYMBOL_POINTERS, 174 SectionKind::getMetadata()); 175 176 ThreadLocalPointerSection 177 = Ctx->getMachOSection("__DATA", "__thread_ptr", 178 MachO::S_THREAD_LOCAL_VARIABLE_POINTERS, 179 SectionKind::getMetadata()); 180 181 // Exception Handling. 182 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0, 183 SectionKind::getReadOnlyWithRel()); 184 185 COFFDebugSymbolsSection = nullptr; 186 COFFDebugTypesSection = nullptr; 187 COFFGlobalTypeHashesSection = nullptr; 188 189 if (useCompactUnwind(T)) { 190 CompactUnwindSection = 191 Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG, 192 SectionKind::getReadOnly()); 193 194 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86) 195 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_X86_64_MODE_DWARF 196 else if (T.getArch() == Triple::aarch64) 197 CompactUnwindDwarfEHFrameOnly = 0x03000000; // UNWIND_ARM64_MODE_DWARF 198 else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb) 199 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_ARM_MODE_DWARF 200 } 201 202 // Debug Information. 203 DwarfDebugNamesSection = 204 Ctx->getMachOSection("__DWARF", "__debug_names", MachO::S_ATTR_DEBUG, 205 SectionKind::getMetadata(), "debug_names_begin"); 206 DwarfAccelNamesSection = 207 Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG, 208 SectionKind::getMetadata(), "names_begin"); 209 DwarfAccelObjCSection = 210 Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG, 211 SectionKind::getMetadata(), "objc_begin"); 212 // 16 character section limit... 213 DwarfAccelNamespaceSection = 214 Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG, 215 SectionKind::getMetadata(), "namespac_begin"); 216 DwarfAccelTypesSection = 217 Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG, 218 SectionKind::getMetadata(), "types_begin"); 219 220 DwarfSwiftASTSection = 221 Ctx->getMachOSection("__DWARF", "__swift_ast", MachO::S_ATTR_DEBUG, 222 SectionKind::getMetadata()); 223 224 DwarfAbbrevSection = 225 Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG, 226 SectionKind::getMetadata(), "section_abbrev"); 227 DwarfInfoSection = 228 Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG, 229 SectionKind::getMetadata(), "section_info"); 230 DwarfLineSection = 231 Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG, 232 SectionKind::getMetadata(), "section_line"); 233 DwarfLineStrSection = 234 Ctx->getMachOSection("__DWARF", "__debug_line_str", MachO::S_ATTR_DEBUG, 235 SectionKind::getMetadata(), "section_line_str"); 236 DwarfFrameSection = 237 Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG, 238 SectionKind::getMetadata()); 239 DwarfPubNamesSection = 240 Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG, 241 SectionKind::getMetadata()); 242 DwarfPubTypesSection = 243 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG, 244 SectionKind::getMetadata()); 245 DwarfGnuPubNamesSection = 246 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG, 247 SectionKind::getMetadata()); 248 DwarfGnuPubTypesSection = 249 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG, 250 SectionKind::getMetadata()); 251 DwarfStrSection = 252 Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG, 253 SectionKind::getMetadata(), "info_string"); 254 DwarfStrOffSection = 255 Ctx->getMachOSection("__DWARF", "__debug_str_offs", MachO::S_ATTR_DEBUG, 256 SectionKind::getMetadata(), "section_str_off"); 257 DwarfLocSection = 258 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG, 259 SectionKind::getMetadata(), "section_debug_loc"); 260 DwarfARangesSection = 261 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG, 262 SectionKind::getMetadata()); 263 DwarfRangesSection = 264 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG, 265 SectionKind::getMetadata(), "debug_range"); 266 DwarfRnglistsSection = 267 Ctx->getMachOSection("__DWARF", "__debug_rnglists", MachO::S_ATTR_DEBUG, 268 SectionKind::getMetadata(), "debug_range"); 269 DwarfMacinfoSection = 270 Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG, 271 SectionKind::getMetadata(), "debug_macinfo"); 272 DwarfDebugInlineSection = 273 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG, 274 SectionKind::getMetadata()); 275 DwarfCUIndexSection = 276 Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG, 277 SectionKind::getMetadata()); 278 DwarfTUIndexSection = 279 Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG, 280 SectionKind::getMetadata()); 281 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 282 0, SectionKind::getMetadata()); 283 284 FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps", 285 0, SectionKind::getMetadata()); 286 287 TLSExtraDataSection = TLSTLVSection; 288 } 289 290 void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) { 291 switch (T.getArch()) { 292 case Triple::mips: 293 case Triple::mipsel: 294 FDECFIEncoding = dwarf::DW_EH_PE_sdata4; 295 break; 296 case Triple::mips64: 297 case Triple::mips64el: 298 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 299 break; 300 case Triple::ppc64: 301 case Triple::ppc64le: 302 case Triple::x86_64: 303 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | 304 (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4); 305 break; 306 case Triple::bpfel: 307 case Triple::bpfeb: 308 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 309 break; 310 case Triple::hexagon: 311 FDECFIEncoding = 312 PositionIndependent ? dwarf::DW_EH_PE_pcrel : dwarf::DW_EH_PE_absptr; 313 default: 314 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 315 break; 316 } 317 318 unsigned EHSectionType = T.getArch() == Triple::x86_64 319 ? ELF::SHT_X86_64_UNWIND 320 : ELF::SHT_PROGBITS; 321 322 // Solaris requires different flags for .eh_frame to seemingly every other 323 // platform. 324 unsigned EHSectionFlags = ELF::SHF_ALLOC; 325 if (T.isOSSolaris() && T.getArch() != Triple::x86_64) 326 EHSectionFlags |= ELF::SHF_WRITE; 327 328 // ELF 329 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 330 ELF::SHF_WRITE | ELF::SHF_ALLOC); 331 332 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 333 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 334 335 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 336 ELF::SHF_WRITE | ELF::SHF_ALLOC); 337 338 ReadOnlySection = 339 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 340 341 TLSDataSection = 342 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 343 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 344 345 TLSBSSSection = Ctx->getELFSection( 346 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 347 348 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 349 ELF::SHF_ALLOC | ELF::SHF_WRITE); 350 351 MergeableConst4Section = 352 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 353 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, ""); 354 355 MergeableConst8Section = 356 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 357 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, ""); 358 359 MergeableConst16Section = 360 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 361 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, ""); 362 363 MergeableConst32Section = 364 Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS, 365 ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, ""); 366 367 // Exception Handling Sections. 368 369 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 370 // it contains relocatable pointers. In PIC mode, this is probably a big 371 // runtime hit for C++ apps. Either the contents of the LSDA need to be 372 // adjusted or this should be a data section. 373 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 374 ELF::SHF_ALLOC); 375 376 COFFDebugSymbolsSection = nullptr; 377 COFFDebugTypesSection = nullptr; 378 379 unsigned DebugSecType = ELF::SHT_PROGBITS; 380 381 // MIPS .debug_* sections should have SHT_MIPS_DWARF section type 382 // to distinguish among sections contain DWARF and ECOFF debug formats. 383 // Sections with ECOFF debug format are obsoleted and marked by SHT_PROGBITS. 384 if (T.isMIPS()) 385 DebugSecType = ELF::SHT_MIPS_DWARF; 386 387 // Debug Info Sections. 388 DwarfAbbrevSection = 389 Ctx->getELFSection(".debug_abbrev", DebugSecType, 0); 390 DwarfInfoSection = Ctx->getELFSection(".debug_info", DebugSecType, 0); 391 DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0); 392 DwarfLineStrSection = 393 Ctx->getELFSection(".debug_line_str", DebugSecType, 394 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 395 DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0); 396 DwarfPubNamesSection = 397 Ctx->getELFSection(".debug_pubnames", DebugSecType, 0); 398 DwarfPubTypesSection = 399 Ctx->getELFSection(".debug_pubtypes", DebugSecType, 0); 400 DwarfGnuPubNamesSection = 401 Ctx->getELFSection(".debug_gnu_pubnames", DebugSecType, 0); 402 DwarfGnuPubTypesSection = 403 Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0); 404 DwarfStrSection = 405 Ctx->getELFSection(".debug_str", DebugSecType, 406 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 407 DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0); 408 DwarfARangesSection = 409 Ctx->getELFSection(".debug_aranges", DebugSecType, 0); 410 DwarfRangesSection = 411 Ctx->getELFSection(".debug_ranges", DebugSecType, 0); 412 DwarfMacinfoSection = 413 Ctx->getELFSection(".debug_macinfo", DebugSecType, 0); 414 415 // DWARF5 Experimental Debug Info 416 417 // Accelerator Tables 418 DwarfDebugNamesSection = 419 Ctx->getELFSection(".debug_names", ELF::SHT_PROGBITS, 0); 420 DwarfAccelNamesSection = 421 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0); 422 DwarfAccelObjCSection = 423 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0); 424 DwarfAccelNamespaceSection = 425 Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0); 426 DwarfAccelTypesSection = 427 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0); 428 429 // String Offset and Address Sections 430 DwarfStrOffSection = 431 Ctx->getELFSection(".debug_str_offsets", DebugSecType, 0); 432 DwarfAddrSection = Ctx->getELFSection(".debug_addr", DebugSecType, 0); 433 DwarfRnglistsSection = Ctx->getELFSection(".debug_rnglists", DebugSecType, 0); 434 435 // Fission Sections 436 DwarfInfoDWOSection = 437 Ctx->getELFSection(".debug_info.dwo", DebugSecType, 0); 438 DwarfTypesDWOSection = 439 Ctx->getELFSection(".debug_types.dwo", DebugSecType, 0); 440 DwarfAbbrevDWOSection = 441 Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, 0); 442 DwarfStrDWOSection = 443 Ctx->getELFSection(".debug_str.dwo", DebugSecType, 444 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 445 DwarfLineDWOSection = 446 Ctx->getELFSection(".debug_line.dwo", DebugSecType, 0); 447 DwarfLocDWOSection = 448 Ctx->getELFSection(".debug_loc.dwo", DebugSecType, 0); 449 DwarfStrOffDWOSection = 450 Ctx->getELFSection(".debug_str_offsets.dwo", DebugSecType, 0); 451 DwarfRnglistsDWOSection = 452 Ctx->getELFSection(".debug_rnglists.dwo", DebugSecType, 0); 453 454 // DWP Sections 455 DwarfCUIndexSection = 456 Ctx->getELFSection(".debug_cu_index", DebugSecType, 0); 457 DwarfTUIndexSection = 458 Ctx->getELFSection(".debug_tu_index", DebugSecType, 0); 459 460 StackMapSection = 461 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 462 463 FaultMapSection = 464 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 465 466 EHFrameSection = 467 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags); 468 469 StackSizesSection = Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, 0); 470 } 471 472 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) { 473 EHFrameSection = Ctx->getCOFFSection( 474 ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 475 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 476 SectionKind::getData()); 477 478 // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode. This is 479 // used to indicate to the linker that the text segment contains thumb instructions 480 // and to set the ISA selection bit for calls accordingly. 481 const bool IsThumb = T.getArch() == Triple::thumb; 482 483 CommDirectiveSupportsAlignment = true; 484 485 // COFF 486 BSSSection = Ctx->getCOFFSection( 487 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | 488 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 489 SectionKind::getBSS()); 490 TextSection = Ctx->getCOFFSection( 491 ".text", 492 (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) | 493 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE | 494 COFF::IMAGE_SCN_MEM_READ, 495 SectionKind::getText()); 496 DataSection = Ctx->getCOFFSection( 497 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 498 COFF::IMAGE_SCN_MEM_WRITE, 499 SectionKind::getData()); 500 ReadOnlySection = Ctx->getCOFFSection( 501 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 502 SectionKind::getReadOnly()); 503 504 // FIXME: We're emitting LSDA info into a readonly section on COFF, even 505 // though it contains relocatable pointers. In PIC mode, this is probably a 506 // big runtime hit for C++ apps. Either the contents of the LSDA need to be 507 // adjusted or this should be a data section. 508 if (T.getArch() == Triple::x86_64) { 509 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section 510 LSDASection = nullptr; 511 } else { 512 LSDASection = Ctx->getCOFFSection(".gcc_except_table", 513 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 514 COFF::IMAGE_SCN_MEM_READ, 515 SectionKind::getReadOnly()); 516 } 517 518 // Debug info. 519 COFFDebugSymbolsSection = 520 Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 521 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 522 COFF::IMAGE_SCN_MEM_READ), 523 SectionKind::getMetadata()); 524 COFFDebugTypesSection = 525 Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 526 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 527 COFF::IMAGE_SCN_MEM_READ), 528 SectionKind::getMetadata()); 529 COFFGlobalTypeHashesSection = Ctx->getCOFFSection( 530 ".debug$H", 531 (COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 532 COFF::IMAGE_SCN_MEM_READ), 533 SectionKind::getMetadata()); 534 535 DwarfAbbrevSection = Ctx->getCOFFSection( 536 ".debug_abbrev", 537 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 538 COFF::IMAGE_SCN_MEM_READ, 539 SectionKind::getMetadata(), "section_abbrev"); 540 DwarfInfoSection = Ctx->getCOFFSection( 541 ".debug_info", 542 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 543 COFF::IMAGE_SCN_MEM_READ, 544 SectionKind::getMetadata(), "section_info"); 545 DwarfLineSection = Ctx->getCOFFSection( 546 ".debug_line", 547 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 548 COFF::IMAGE_SCN_MEM_READ, 549 SectionKind::getMetadata(), "section_line"); 550 DwarfLineStrSection = Ctx->getCOFFSection( 551 ".debug_line_str", 552 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 553 COFF::IMAGE_SCN_MEM_READ, 554 SectionKind::getMetadata(), "section_line_str"); 555 DwarfFrameSection = Ctx->getCOFFSection( 556 ".debug_frame", 557 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 558 COFF::IMAGE_SCN_MEM_READ, 559 SectionKind::getMetadata()); 560 DwarfPubNamesSection = Ctx->getCOFFSection( 561 ".debug_pubnames", 562 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 563 COFF::IMAGE_SCN_MEM_READ, 564 SectionKind::getMetadata()); 565 DwarfPubTypesSection = Ctx->getCOFFSection( 566 ".debug_pubtypes", 567 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 568 COFF::IMAGE_SCN_MEM_READ, 569 SectionKind::getMetadata()); 570 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 571 ".debug_gnu_pubnames", 572 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 573 COFF::IMAGE_SCN_MEM_READ, 574 SectionKind::getMetadata()); 575 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 576 ".debug_gnu_pubtypes", 577 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 578 COFF::IMAGE_SCN_MEM_READ, 579 SectionKind::getMetadata()); 580 DwarfStrSection = Ctx->getCOFFSection( 581 ".debug_str", 582 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 583 COFF::IMAGE_SCN_MEM_READ, 584 SectionKind::getMetadata(), "info_string"); 585 DwarfStrOffSection = Ctx->getCOFFSection( 586 ".debug_str_offsets", 587 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 588 COFF::IMAGE_SCN_MEM_READ, 589 SectionKind::getMetadata(), "section_str_off"); 590 DwarfLocSection = Ctx->getCOFFSection( 591 ".debug_loc", 592 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 593 COFF::IMAGE_SCN_MEM_READ, 594 SectionKind::getMetadata(), "section_debug_loc"); 595 DwarfARangesSection = Ctx->getCOFFSection( 596 ".debug_aranges", 597 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 598 COFF::IMAGE_SCN_MEM_READ, 599 SectionKind::getMetadata()); 600 DwarfRangesSection = Ctx->getCOFFSection( 601 ".debug_ranges", 602 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 603 COFF::IMAGE_SCN_MEM_READ, 604 SectionKind::getMetadata(), "debug_range"); 605 DwarfMacinfoSection = Ctx->getCOFFSection( 606 ".debug_macinfo", 607 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 608 COFF::IMAGE_SCN_MEM_READ, 609 SectionKind::getMetadata(), "debug_macinfo"); 610 DwarfInfoDWOSection = Ctx->getCOFFSection( 611 ".debug_info.dwo", 612 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 613 COFF::IMAGE_SCN_MEM_READ, 614 SectionKind::getMetadata(), "section_info_dwo"); 615 DwarfTypesDWOSection = Ctx->getCOFFSection( 616 ".debug_types.dwo", 617 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 618 COFF::IMAGE_SCN_MEM_READ, 619 SectionKind::getMetadata(), "section_types_dwo"); 620 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 621 ".debug_abbrev.dwo", 622 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 623 COFF::IMAGE_SCN_MEM_READ, 624 SectionKind::getMetadata(), "section_abbrev_dwo"); 625 DwarfStrDWOSection = Ctx->getCOFFSection( 626 ".debug_str.dwo", 627 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 628 COFF::IMAGE_SCN_MEM_READ, 629 SectionKind::getMetadata(), "skel_string"); 630 DwarfLineDWOSection = Ctx->getCOFFSection( 631 ".debug_line.dwo", 632 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 633 COFF::IMAGE_SCN_MEM_READ, 634 SectionKind::getMetadata()); 635 DwarfLocDWOSection = Ctx->getCOFFSection( 636 ".debug_loc.dwo", 637 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 638 COFF::IMAGE_SCN_MEM_READ, 639 SectionKind::getMetadata(), "skel_loc"); 640 DwarfStrOffDWOSection = Ctx->getCOFFSection( 641 ".debug_str_offsets.dwo", 642 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 643 COFF::IMAGE_SCN_MEM_READ, 644 SectionKind::getMetadata(), "section_str_off_dwo"); 645 DwarfAddrSection = Ctx->getCOFFSection( 646 ".debug_addr", 647 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 648 COFF::IMAGE_SCN_MEM_READ, 649 SectionKind::getMetadata(), "addr_sec"); 650 DwarfCUIndexSection = Ctx->getCOFFSection( 651 ".debug_cu_index", 652 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 653 COFF::IMAGE_SCN_MEM_READ, 654 SectionKind::getMetadata()); 655 DwarfTUIndexSection = Ctx->getCOFFSection( 656 ".debug_tu_index", 657 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 658 COFF::IMAGE_SCN_MEM_READ, 659 SectionKind::getMetadata()); 660 DwarfDebugNamesSection = Ctx->getCOFFSection( 661 ".debug_names", 662 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 663 COFF::IMAGE_SCN_MEM_READ, 664 SectionKind::getMetadata(), "debug_names_begin"); 665 DwarfAccelNamesSection = Ctx->getCOFFSection( 666 ".apple_names", 667 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 668 COFF::IMAGE_SCN_MEM_READ, 669 SectionKind::getMetadata(), "names_begin"); 670 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 671 ".apple_namespaces", 672 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 673 COFF::IMAGE_SCN_MEM_READ, 674 SectionKind::getMetadata(), "namespac_begin"); 675 DwarfAccelTypesSection = Ctx->getCOFFSection( 676 ".apple_types", 677 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 678 COFF::IMAGE_SCN_MEM_READ, 679 SectionKind::getMetadata(), "types_begin"); 680 DwarfAccelObjCSection = Ctx->getCOFFSection( 681 ".apple_objc", 682 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 683 COFF::IMAGE_SCN_MEM_READ, 684 SectionKind::getMetadata(), "objc_begin"); 685 686 DrectveSection = Ctx->getCOFFSection( 687 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 688 SectionKind::getMetadata()); 689 690 PDataSection = Ctx->getCOFFSection( 691 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 692 SectionKind::getData()); 693 694 XDataSection = Ctx->getCOFFSection( 695 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 696 SectionKind::getData()); 697 698 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 699 SectionKind::getMetadata()); 700 701 GFIDsSection = Ctx->getCOFFSection(".gfids$y", 702 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 703 COFF::IMAGE_SCN_MEM_READ, 704 SectionKind::getMetadata()); 705 706 TLSDataSection = Ctx->getCOFFSection( 707 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 708 COFF::IMAGE_SCN_MEM_WRITE, 709 SectionKind::getData()); 710 711 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 712 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 713 COFF::IMAGE_SCN_MEM_READ, 714 SectionKind::getReadOnly()); 715 } 716 717 void MCObjectFileInfo::initWasmMCObjectFileInfo(const Triple &T) { 718 TextSection = Ctx->getWasmSection(".text", SectionKind::getText()); 719 DataSection = Ctx->getWasmSection(".data", SectionKind::getData()); 720 721 DwarfLineSection = 722 Ctx->getWasmSection(".debug_line", SectionKind::getMetadata()); 723 DwarfLineStrSection = 724 Ctx->getWasmSection(".debug_line_str", SectionKind::getMetadata()); 725 DwarfStrSection = 726 Ctx->getWasmSection(".debug_str", SectionKind::getMetadata()); 727 DwarfLocSection = 728 Ctx->getWasmSection(".debug_loc", SectionKind::getMetadata()); 729 DwarfAbbrevSection = 730 Ctx->getWasmSection(".debug_abbrev", SectionKind::getMetadata()); 731 DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", SectionKind::getMetadata()); 732 DwarfRangesSection = 733 Ctx->getWasmSection(".debug_ranges", SectionKind::getMetadata()); 734 DwarfMacinfoSection = 735 Ctx->getWasmSection(".debug_macinfo", SectionKind::getMetadata()); 736 DwarfAddrSection = Ctx->getWasmSection(".debug_addr", SectionKind::getMetadata()); 737 DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", SectionKind::getMetadata()); 738 DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", SectionKind::getMetadata()); 739 DwarfInfoSection = 740 Ctx->getWasmSection(".debug_info", SectionKind::getMetadata()); 741 DwarfFrameSection = Ctx->getWasmSection(".debug_frame", SectionKind::getMetadata()); 742 DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", SectionKind::getMetadata()); 743 DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", SectionKind::getMetadata()); 744 745 // TODO: Define more sections. 746 } 747 748 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC, 749 MCContext &ctx, 750 bool LargeCodeModel) { 751 PositionIndependent = PIC; 752 Ctx = &ctx; 753 754 // Common. 755 CommDirectiveSupportsAlignment = true; 756 SupportsWeakOmittedEHFrame = true; 757 SupportsCompactUnwindWithoutEHFrame = false; 758 OmitDwarfIfHaveCompactUnwind = false; 759 760 FDECFIEncoding = dwarf::DW_EH_PE_absptr; 761 762 CompactUnwindDwarfEHFrameOnly = 0; 763 764 EHFrameSection = nullptr; // Created on demand. 765 CompactUnwindSection = nullptr; // Used only by selected targets. 766 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 767 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 768 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 769 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 770 771 TT = TheTriple; 772 773 switch (TT.getObjectFormat()) { 774 case Triple::MachO: 775 Env = IsMachO; 776 initMachOMCObjectFileInfo(TT); 777 break; 778 case Triple::COFF: 779 if (!TT.isOSWindows()) 780 report_fatal_error( 781 "Cannot initialize MC for non-Windows COFF object files."); 782 783 Env = IsCOFF; 784 initCOFFMCObjectFileInfo(TT); 785 break; 786 case Triple::ELF: 787 Env = IsELF; 788 initELFMCObjectFileInfo(TT, LargeCodeModel); 789 break; 790 case Triple::Wasm: 791 Env = IsWasm; 792 initWasmMCObjectFileInfo(TT); 793 break; 794 case Triple::UnknownObjectFormat: 795 report_fatal_error("Cannot initialize MC for unknown object file format."); 796 break; 797 } 798 } 799 800 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const { 801 switch (TT.getObjectFormat()) { 802 case Triple::ELF: 803 return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP, 804 0, utostr(Hash)); 805 case Triple::MachO: 806 case Triple::COFF: 807 case Triple::Wasm: 808 case Triple::UnknownObjectFormat: 809 report_fatal_error("Cannot get DWARF types section for this object file " 810 "format: not implemented."); 811 break; 812 } 813 llvm_unreachable("Unknown ObjectFormatType"); 814 } 815 816 MCSection * 817 MCObjectFileInfo::getStackSizesSection(const MCSection &TextSec) const { 818 if (Env != IsELF) 819 return StackSizesSection; 820 821 const MCSectionELF &ElfSec = static_cast<const MCSectionELF &>(TextSec); 822 unsigned Flags = ELF::SHF_LINK_ORDER; 823 StringRef GroupName; 824 if (const MCSymbol *Group = ElfSec.getGroup()) { 825 GroupName = Group->getName(); 826 Flags |= ELF::SHF_GROUP; 827 } 828 829 const MCSymbol *Link = TextSec.getBeginSymbol(); 830 auto It = StackSizesUniquing.insert({Link, StackSizesUniquing.size()}); 831 unsigned UniqueID = It.first->second; 832 833 return Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, Flags, 0, 834 GroupName, UniqueID, cast<MCSymbolELF>(Link)); 835 } 836