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 break; 314 default: 315 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 316 break; 317 } 318 319 unsigned EHSectionType = T.getArch() == Triple::x86_64 320 ? ELF::SHT_X86_64_UNWIND 321 : ELF::SHT_PROGBITS; 322 323 // Solaris requires different flags for .eh_frame to seemingly every other 324 // platform. 325 unsigned EHSectionFlags = ELF::SHF_ALLOC; 326 if (T.isOSSolaris() && T.getArch() != Triple::x86_64) 327 EHSectionFlags |= ELF::SHF_WRITE; 328 329 // ELF 330 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 331 ELF::SHF_WRITE | ELF::SHF_ALLOC); 332 333 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 334 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 335 336 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 337 ELF::SHF_WRITE | ELF::SHF_ALLOC); 338 339 ReadOnlySection = 340 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 341 342 TLSDataSection = 343 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 344 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 345 346 TLSBSSSection = Ctx->getELFSection( 347 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 348 349 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 350 ELF::SHF_ALLOC | ELF::SHF_WRITE); 351 352 MergeableConst4Section = 353 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 354 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, ""); 355 356 MergeableConst8Section = 357 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 358 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, ""); 359 360 MergeableConst16Section = 361 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 362 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, ""); 363 364 MergeableConst32Section = 365 Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS, 366 ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, ""); 367 368 // Exception Handling Sections. 369 370 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 371 // it contains relocatable pointers. In PIC mode, this is probably a big 372 // runtime hit for C++ apps. Either the contents of the LSDA need to be 373 // adjusted or this should be a data section. 374 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 375 ELF::SHF_ALLOC); 376 377 COFFDebugSymbolsSection = nullptr; 378 COFFDebugTypesSection = nullptr; 379 380 unsigned DebugSecType = ELF::SHT_PROGBITS; 381 382 // MIPS .debug_* sections should have SHT_MIPS_DWARF section type 383 // to distinguish among sections contain DWARF and ECOFF debug formats. 384 // Sections with ECOFF debug format are obsoleted and marked by SHT_PROGBITS. 385 if (T.isMIPS()) 386 DebugSecType = ELF::SHT_MIPS_DWARF; 387 388 // Debug Info Sections. 389 DwarfAbbrevSection = 390 Ctx->getELFSection(".debug_abbrev", DebugSecType, 0); 391 DwarfInfoSection = Ctx->getELFSection(".debug_info", DebugSecType, 0); 392 DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0); 393 DwarfLineStrSection = 394 Ctx->getELFSection(".debug_line_str", DebugSecType, 395 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 396 DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0); 397 DwarfPubNamesSection = 398 Ctx->getELFSection(".debug_pubnames", DebugSecType, 0); 399 DwarfPubTypesSection = 400 Ctx->getELFSection(".debug_pubtypes", DebugSecType, 0); 401 DwarfGnuPubNamesSection = 402 Ctx->getELFSection(".debug_gnu_pubnames", DebugSecType, 0); 403 DwarfGnuPubTypesSection = 404 Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0); 405 DwarfStrSection = 406 Ctx->getELFSection(".debug_str", DebugSecType, 407 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 408 DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0); 409 DwarfARangesSection = 410 Ctx->getELFSection(".debug_aranges", DebugSecType, 0); 411 DwarfRangesSection = 412 Ctx->getELFSection(".debug_ranges", DebugSecType, 0); 413 DwarfMacinfoSection = 414 Ctx->getELFSection(".debug_macinfo", DebugSecType, 0); 415 416 // DWARF5 Experimental Debug Info 417 418 // Accelerator Tables 419 DwarfDebugNamesSection = 420 Ctx->getELFSection(".debug_names", ELF::SHT_PROGBITS, 0); 421 DwarfAccelNamesSection = 422 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0); 423 DwarfAccelObjCSection = 424 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0); 425 DwarfAccelNamespaceSection = 426 Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0); 427 DwarfAccelTypesSection = 428 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0); 429 430 // String Offset and Address Sections 431 DwarfStrOffSection = 432 Ctx->getELFSection(".debug_str_offsets", DebugSecType, 0); 433 DwarfAddrSection = Ctx->getELFSection(".debug_addr", DebugSecType, 0); 434 DwarfRnglistsSection = Ctx->getELFSection(".debug_rnglists", DebugSecType, 0); 435 436 // Fission Sections 437 DwarfInfoDWOSection = 438 Ctx->getELFSection(".debug_info.dwo", DebugSecType, ELF::SHF_EXCLUDE); 439 DwarfTypesDWOSection = 440 Ctx->getELFSection(".debug_types.dwo", DebugSecType, ELF::SHF_EXCLUDE); 441 DwarfAbbrevDWOSection = 442 Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, ELF::SHF_EXCLUDE); 443 DwarfStrDWOSection = Ctx->getELFSection( 444 ".debug_str.dwo", DebugSecType, 445 ELF::SHF_MERGE | ELF::SHF_STRINGS | ELF::SHF_EXCLUDE, 1, ""); 446 DwarfLineDWOSection = 447 Ctx->getELFSection(".debug_line.dwo", DebugSecType, ELF::SHF_EXCLUDE); 448 DwarfLocDWOSection = 449 Ctx->getELFSection(".debug_loc.dwo", DebugSecType, ELF::SHF_EXCLUDE); 450 DwarfStrOffDWOSection = Ctx->getELFSection(".debug_str_offsets.dwo", 451 DebugSecType, ELF::SHF_EXCLUDE); 452 DwarfRnglistsDWOSection = 453 Ctx->getELFSection(".debug_rnglists.dwo", DebugSecType, ELF::SHF_EXCLUDE); 454 455 // DWP Sections 456 DwarfCUIndexSection = 457 Ctx->getELFSection(".debug_cu_index", DebugSecType, 0); 458 DwarfTUIndexSection = 459 Ctx->getELFSection(".debug_tu_index", DebugSecType, 0); 460 461 StackMapSection = 462 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 463 464 FaultMapSection = 465 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 466 467 EHFrameSection = 468 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags); 469 470 StackSizesSection = Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, 0); 471 } 472 473 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) { 474 EHFrameSection = Ctx->getCOFFSection( 475 ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 476 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 477 SectionKind::getData()); 478 479 // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode. This is 480 // used to indicate to the linker that the text segment contains thumb instructions 481 // and to set the ISA selection bit for calls accordingly. 482 const bool IsThumb = T.getArch() == Triple::thumb; 483 484 CommDirectiveSupportsAlignment = true; 485 486 // COFF 487 BSSSection = Ctx->getCOFFSection( 488 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | 489 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 490 SectionKind::getBSS()); 491 TextSection = Ctx->getCOFFSection( 492 ".text", 493 (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) | 494 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE | 495 COFF::IMAGE_SCN_MEM_READ, 496 SectionKind::getText()); 497 DataSection = Ctx->getCOFFSection( 498 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 499 COFF::IMAGE_SCN_MEM_WRITE, 500 SectionKind::getData()); 501 ReadOnlySection = Ctx->getCOFFSection( 502 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 503 SectionKind::getReadOnly()); 504 505 // FIXME: We're emitting LSDA info into a readonly section on COFF, even 506 // though it contains relocatable pointers. In PIC mode, this is probably a 507 // big runtime hit for C++ apps. Either the contents of the LSDA need to be 508 // adjusted or this should be a data section. 509 if (T.getArch() == Triple::x86_64) { 510 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section 511 LSDASection = nullptr; 512 } else { 513 LSDASection = Ctx->getCOFFSection(".gcc_except_table", 514 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 515 COFF::IMAGE_SCN_MEM_READ, 516 SectionKind::getReadOnly()); 517 } 518 519 // Debug info. 520 COFFDebugSymbolsSection = 521 Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 522 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 523 COFF::IMAGE_SCN_MEM_READ), 524 SectionKind::getMetadata()); 525 COFFDebugTypesSection = 526 Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 527 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 528 COFF::IMAGE_SCN_MEM_READ), 529 SectionKind::getMetadata()); 530 COFFGlobalTypeHashesSection = Ctx->getCOFFSection( 531 ".debug$H", 532 (COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 533 COFF::IMAGE_SCN_MEM_READ), 534 SectionKind::getMetadata()); 535 536 DwarfAbbrevSection = Ctx->getCOFFSection( 537 ".debug_abbrev", 538 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 539 COFF::IMAGE_SCN_MEM_READ, 540 SectionKind::getMetadata(), "section_abbrev"); 541 DwarfInfoSection = Ctx->getCOFFSection( 542 ".debug_info", 543 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 544 COFF::IMAGE_SCN_MEM_READ, 545 SectionKind::getMetadata(), "section_info"); 546 DwarfLineSection = Ctx->getCOFFSection( 547 ".debug_line", 548 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 549 COFF::IMAGE_SCN_MEM_READ, 550 SectionKind::getMetadata(), "section_line"); 551 DwarfLineStrSection = Ctx->getCOFFSection( 552 ".debug_line_str", 553 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 554 COFF::IMAGE_SCN_MEM_READ, 555 SectionKind::getMetadata(), "section_line_str"); 556 DwarfFrameSection = Ctx->getCOFFSection( 557 ".debug_frame", 558 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 559 COFF::IMAGE_SCN_MEM_READ, 560 SectionKind::getMetadata()); 561 DwarfPubNamesSection = Ctx->getCOFFSection( 562 ".debug_pubnames", 563 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 564 COFF::IMAGE_SCN_MEM_READ, 565 SectionKind::getMetadata()); 566 DwarfPubTypesSection = Ctx->getCOFFSection( 567 ".debug_pubtypes", 568 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 569 COFF::IMAGE_SCN_MEM_READ, 570 SectionKind::getMetadata()); 571 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 572 ".debug_gnu_pubnames", 573 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 574 COFF::IMAGE_SCN_MEM_READ, 575 SectionKind::getMetadata()); 576 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 577 ".debug_gnu_pubtypes", 578 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 579 COFF::IMAGE_SCN_MEM_READ, 580 SectionKind::getMetadata()); 581 DwarfStrSection = Ctx->getCOFFSection( 582 ".debug_str", 583 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 584 COFF::IMAGE_SCN_MEM_READ, 585 SectionKind::getMetadata(), "info_string"); 586 DwarfStrOffSection = Ctx->getCOFFSection( 587 ".debug_str_offsets", 588 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 589 COFF::IMAGE_SCN_MEM_READ, 590 SectionKind::getMetadata(), "section_str_off"); 591 DwarfLocSection = Ctx->getCOFFSection( 592 ".debug_loc", 593 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 594 COFF::IMAGE_SCN_MEM_READ, 595 SectionKind::getMetadata(), "section_debug_loc"); 596 DwarfARangesSection = Ctx->getCOFFSection( 597 ".debug_aranges", 598 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 599 COFF::IMAGE_SCN_MEM_READ, 600 SectionKind::getMetadata()); 601 DwarfRangesSection = Ctx->getCOFFSection( 602 ".debug_ranges", 603 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 604 COFF::IMAGE_SCN_MEM_READ, 605 SectionKind::getMetadata(), "debug_range"); 606 DwarfMacinfoSection = Ctx->getCOFFSection( 607 ".debug_macinfo", 608 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 609 COFF::IMAGE_SCN_MEM_READ, 610 SectionKind::getMetadata(), "debug_macinfo"); 611 DwarfInfoDWOSection = Ctx->getCOFFSection( 612 ".debug_info.dwo", 613 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 614 COFF::IMAGE_SCN_MEM_READ, 615 SectionKind::getMetadata(), "section_info_dwo"); 616 DwarfTypesDWOSection = Ctx->getCOFFSection( 617 ".debug_types.dwo", 618 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 619 COFF::IMAGE_SCN_MEM_READ, 620 SectionKind::getMetadata(), "section_types_dwo"); 621 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 622 ".debug_abbrev.dwo", 623 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 624 COFF::IMAGE_SCN_MEM_READ, 625 SectionKind::getMetadata(), "section_abbrev_dwo"); 626 DwarfStrDWOSection = Ctx->getCOFFSection( 627 ".debug_str.dwo", 628 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 629 COFF::IMAGE_SCN_MEM_READ, 630 SectionKind::getMetadata(), "skel_string"); 631 DwarfLineDWOSection = Ctx->getCOFFSection( 632 ".debug_line.dwo", 633 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 634 COFF::IMAGE_SCN_MEM_READ, 635 SectionKind::getMetadata()); 636 DwarfLocDWOSection = Ctx->getCOFFSection( 637 ".debug_loc.dwo", 638 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 639 COFF::IMAGE_SCN_MEM_READ, 640 SectionKind::getMetadata(), "skel_loc"); 641 DwarfStrOffDWOSection = Ctx->getCOFFSection( 642 ".debug_str_offsets.dwo", 643 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 644 COFF::IMAGE_SCN_MEM_READ, 645 SectionKind::getMetadata(), "section_str_off_dwo"); 646 DwarfAddrSection = Ctx->getCOFFSection( 647 ".debug_addr", 648 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 649 COFF::IMAGE_SCN_MEM_READ, 650 SectionKind::getMetadata(), "addr_sec"); 651 DwarfCUIndexSection = Ctx->getCOFFSection( 652 ".debug_cu_index", 653 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 654 COFF::IMAGE_SCN_MEM_READ, 655 SectionKind::getMetadata()); 656 DwarfTUIndexSection = Ctx->getCOFFSection( 657 ".debug_tu_index", 658 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 659 COFF::IMAGE_SCN_MEM_READ, 660 SectionKind::getMetadata()); 661 DwarfDebugNamesSection = Ctx->getCOFFSection( 662 ".debug_names", 663 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 664 COFF::IMAGE_SCN_MEM_READ, 665 SectionKind::getMetadata(), "debug_names_begin"); 666 DwarfAccelNamesSection = Ctx->getCOFFSection( 667 ".apple_names", 668 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 669 COFF::IMAGE_SCN_MEM_READ, 670 SectionKind::getMetadata(), "names_begin"); 671 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 672 ".apple_namespaces", 673 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 674 COFF::IMAGE_SCN_MEM_READ, 675 SectionKind::getMetadata(), "namespac_begin"); 676 DwarfAccelTypesSection = Ctx->getCOFFSection( 677 ".apple_types", 678 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 679 COFF::IMAGE_SCN_MEM_READ, 680 SectionKind::getMetadata(), "types_begin"); 681 DwarfAccelObjCSection = Ctx->getCOFFSection( 682 ".apple_objc", 683 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 684 COFF::IMAGE_SCN_MEM_READ, 685 SectionKind::getMetadata(), "objc_begin"); 686 687 DrectveSection = Ctx->getCOFFSection( 688 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 689 SectionKind::getMetadata()); 690 691 PDataSection = Ctx->getCOFFSection( 692 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 693 SectionKind::getData()); 694 695 XDataSection = Ctx->getCOFFSection( 696 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 697 SectionKind::getData()); 698 699 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 700 SectionKind::getMetadata()); 701 702 GFIDsSection = Ctx->getCOFFSection(".gfids$y", 703 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 704 COFF::IMAGE_SCN_MEM_READ, 705 SectionKind::getMetadata()); 706 707 TLSDataSection = Ctx->getCOFFSection( 708 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 709 COFF::IMAGE_SCN_MEM_WRITE, 710 SectionKind::getData()); 711 712 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 713 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 714 COFF::IMAGE_SCN_MEM_READ, 715 SectionKind::getReadOnly()); 716 } 717 718 void MCObjectFileInfo::initWasmMCObjectFileInfo(const Triple &T) { 719 TextSection = Ctx->getWasmSection(".text", SectionKind::getText()); 720 DataSection = Ctx->getWasmSection(".data", SectionKind::getData()); 721 722 DwarfLineSection = 723 Ctx->getWasmSection(".debug_line", SectionKind::getMetadata()); 724 DwarfLineStrSection = 725 Ctx->getWasmSection(".debug_line_str", SectionKind::getMetadata()); 726 DwarfStrSection = 727 Ctx->getWasmSection(".debug_str", SectionKind::getMetadata()); 728 DwarfLocSection = 729 Ctx->getWasmSection(".debug_loc", SectionKind::getMetadata()); 730 DwarfAbbrevSection = 731 Ctx->getWasmSection(".debug_abbrev", SectionKind::getMetadata()); 732 DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", SectionKind::getMetadata()); 733 DwarfRangesSection = 734 Ctx->getWasmSection(".debug_ranges", SectionKind::getMetadata()); 735 DwarfMacinfoSection = 736 Ctx->getWasmSection(".debug_macinfo", SectionKind::getMetadata()); 737 DwarfAddrSection = Ctx->getWasmSection(".debug_addr", SectionKind::getMetadata()); 738 DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", SectionKind::getMetadata()); 739 DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", SectionKind::getMetadata()); 740 DwarfInfoSection = 741 Ctx->getWasmSection(".debug_info", SectionKind::getMetadata()); 742 DwarfFrameSection = Ctx->getWasmSection(".debug_frame", SectionKind::getMetadata()); 743 DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", SectionKind::getMetadata()); 744 DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", SectionKind::getMetadata()); 745 746 // TODO: Define more sections. 747 } 748 749 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC, 750 MCContext &ctx, 751 bool LargeCodeModel) { 752 PositionIndependent = PIC; 753 Ctx = &ctx; 754 755 // Common. 756 CommDirectiveSupportsAlignment = true; 757 SupportsWeakOmittedEHFrame = true; 758 SupportsCompactUnwindWithoutEHFrame = false; 759 OmitDwarfIfHaveCompactUnwind = false; 760 761 FDECFIEncoding = dwarf::DW_EH_PE_absptr; 762 763 CompactUnwindDwarfEHFrameOnly = 0; 764 765 EHFrameSection = nullptr; // Created on demand. 766 CompactUnwindSection = nullptr; // Used only by selected targets. 767 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 768 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 769 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 770 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 771 772 TT = TheTriple; 773 774 switch (TT.getObjectFormat()) { 775 case Triple::MachO: 776 Env = IsMachO; 777 initMachOMCObjectFileInfo(TT); 778 break; 779 case Triple::COFF: 780 if (!TT.isOSWindows()) 781 report_fatal_error( 782 "Cannot initialize MC for non-Windows COFF object files."); 783 784 Env = IsCOFF; 785 initCOFFMCObjectFileInfo(TT); 786 break; 787 case Triple::ELF: 788 Env = IsELF; 789 initELFMCObjectFileInfo(TT, LargeCodeModel); 790 break; 791 case Triple::Wasm: 792 Env = IsWasm; 793 initWasmMCObjectFileInfo(TT); 794 break; 795 case Triple::UnknownObjectFormat: 796 report_fatal_error("Cannot initialize MC for unknown object file format."); 797 break; 798 } 799 } 800 801 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const { 802 switch (TT.getObjectFormat()) { 803 case Triple::ELF: 804 return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP, 805 0, utostr(Hash)); 806 case Triple::MachO: 807 case Triple::COFF: 808 case Triple::Wasm: 809 case Triple::UnknownObjectFormat: 810 report_fatal_error("Cannot get DWARF types section for this object file " 811 "format: not implemented."); 812 break; 813 } 814 llvm_unreachable("Unknown ObjectFormatType"); 815 } 816 817 MCSection * 818 MCObjectFileInfo::getStackSizesSection(const MCSection &TextSec) const { 819 if (Env != IsELF) 820 return StackSizesSection; 821 822 const MCSectionELF &ElfSec = static_cast<const MCSectionELF &>(TextSec); 823 unsigned Flags = ELF::SHF_LINK_ORDER; 824 StringRef GroupName; 825 if (const MCSymbol *Group = ElfSec.getGroup()) { 826 GroupName = Group->getName(); 827 Flags |= ELF::SHF_GROUP; 828 } 829 830 const MCSymbol *Link = TextSec.getBeginSymbol(); 831 auto It = StackSizesUniquing.insert({Link, StackSizesUniquing.size()}); 832 unsigned UniqueID = It.first->second; 833 834 return Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, Flags, 0, 835 GroupName, UniqueID, cast<MCSymbolELF>(Link)); 836 } 837