1 //===-- MCObjectFileInfo.cpp - Object File Information --------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/MC/MCObjectFileInfo.h" 10 #include "llvm/ADT/StringExtras.h" 11 #include "llvm/ADT/Triple.h" 12 #include "llvm/BinaryFormat/COFF.h" 13 #include "llvm/BinaryFormat/ELF.h" 14 #include "llvm/MC/MCAsmInfo.h" 15 #include "llvm/MC/MCContext.h" 16 #include "llvm/MC/MCSection.h" 17 #include "llvm/MC/MCSectionCOFF.h" 18 #include "llvm/MC/MCSectionELF.h" 19 #include "llvm/MC/MCSectionMachO.h" 20 #include "llvm/MC/MCSectionWasm.h" 21 #include "llvm/MC/MCSectionXCOFF.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 DwarfAddrSection = 258 Ctx->getMachOSection("__DWARF", "__debug_addr", MachO::S_ATTR_DEBUG, 259 SectionKind::getMetadata(), "section_info"); 260 DwarfLocSection = 261 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG, 262 SectionKind::getMetadata(), "section_debug_loc"); 263 DwarfLoclistsSection = 264 Ctx->getMachOSection("__DWARF", "__debug_loclists", MachO::S_ATTR_DEBUG, 265 SectionKind::getMetadata(), "section_debug_loc"); 266 267 DwarfARangesSection = 268 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG, 269 SectionKind::getMetadata()); 270 DwarfRangesSection = 271 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG, 272 SectionKind::getMetadata(), "debug_range"); 273 DwarfRnglistsSection = 274 Ctx->getMachOSection("__DWARF", "__debug_rnglists", MachO::S_ATTR_DEBUG, 275 SectionKind::getMetadata(), "debug_range"); 276 DwarfMacinfoSection = 277 Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG, 278 SectionKind::getMetadata(), "debug_macinfo"); 279 DwarfDebugInlineSection = 280 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG, 281 SectionKind::getMetadata()); 282 DwarfCUIndexSection = 283 Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG, 284 SectionKind::getMetadata()); 285 DwarfTUIndexSection = 286 Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG, 287 SectionKind::getMetadata()); 288 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 289 0, SectionKind::getMetadata()); 290 291 FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps", 292 0, SectionKind::getMetadata()); 293 294 RemarksSection = Ctx->getMachOSection( 295 "__LLVM", "__remarks", MachO::S_ATTR_DEBUG, SectionKind::getMetadata()); 296 297 TLSExtraDataSection = TLSTLVSection; 298 } 299 300 void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) { 301 switch (T.getArch()) { 302 case Triple::mips: 303 case Triple::mipsel: 304 case Triple::mips64: 305 case Triple::mips64el: 306 // We cannot use DW_EH_PE_sdata8 for the large PositionIndependent case 307 // since there is no R_MIPS_PC64 relocation (only a 32-bit version). 308 if (PositionIndependent && !Large) 309 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 310 else 311 FDECFIEncoding = Ctx->getAsmInfo()->getCodePointerSize() == 4 312 ? dwarf::DW_EH_PE_sdata4 313 : dwarf::DW_EH_PE_sdata8; 314 break; 315 case Triple::ppc64: 316 case Triple::ppc64le: 317 case Triple::x86_64: 318 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | 319 (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4); 320 break; 321 case Triple::bpfel: 322 case Triple::bpfeb: 323 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 324 break; 325 case Triple::hexagon: 326 FDECFIEncoding = 327 PositionIndependent ? dwarf::DW_EH_PE_pcrel : dwarf::DW_EH_PE_absptr; 328 break; 329 default: 330 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 331 break; 332 } 333 334 unsigned EHSectionType = T.getArch() == Triple::x86_64 335 ? ELF::SHT_X86_64_UNWIND 336 : ELF::SHT_PROGBITS; 337 338 // Solaris requires different flags for .eh_frame to seemingly every other 339 // platform. 340 unsigned EHSectionFlags = ELF::SHF_ALLOC; 341 if (T.isOSSolaris() && T.getArch() != Triple::x86_64) 342 EHSectionFlags |= ELF::SHF_WRITE; 343 344 // ELF 345 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 346 ELF::SHF_WRITE | ELF::SHF_ALLOC); 347 348 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 349 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 350 351 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 352 ELF::SHF_WRITE | ELF::SHF_ALLOC); 353 354 ReadOnlySection = 355 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 356 357 TLSDataSection = 358 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 359 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 360 361 TLSBSSSection = Ctx->getELFSection( 362 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 363 364 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 365 ELF::SHF_ALLOC | ELF::SHF_WRITE); 366 367 MergeableConst4Section = 368 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 369 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, ""); 370 371 MergeableConst8Section = 372 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 373 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, ""); 374 375 MergeableConst16Section = 376 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 377 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, ""); 378 379 MergeableConst32Section = 380 Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS, 381 ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, ""); 382 383 // Exception Handling Sections. 384 385 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 386 // it contains relocatable pointers. In PIC mode, this is probably a big 387 // runtime hit for C++ apps. Either the contents of the LSDA need to be 388 // adjusted or this should be a data section. 389 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 390 ELF::SHF_ALLOC); 391 392 COFFDebugSymbolsSection = nullptr; 393 COFFDebugTypesSection = nullptr; 394 395 unsigned DebugSecType = ELF::SHT_PROGBITS; 396 397 // MIPS .debug_* sections should have SHT_MIPS_DWARF section type 398 // to distinguish among sections contain DWARF and ECOFF debug formats. 399 // Sections with ECOFF debug format are obsoleted and marked by SHT_PROGBITS. 400 if (T.isMIPS()) 401 DebugSecType = ELF::SHT_MIPS_DWARF; 402 403 // Debug Info Sections. 404 DwarfAbbrevSection = 405 Ctx->getELFSection(".debug_abbrev", DebugSecType, 0); 406 DwarfInfoSection = Ctx->getELFSection(".debug_info", DebugSecType, 0); 407 DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0); 408 DwarfLineStrSection = 409 Ctx->getELFSection(".debug_line_str", DebugSecType, 410 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 411 DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0); 412 DwarfPubNamesSection = 413 Ctx->getELFSection(".debug_pubnames", DebugSecType, 0); 414 DwarfPubTypesSection = 415 Ctx->getELFSection(".debug_pubtypes", DebugSecType, 0); 416 DwarfGnuPubNamesSection = 417 Ctx->getELFSection(".debug_gnu_pubnames", DebugSecType, 0); 418 DwarfGnuPubTypesSection = 419 Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0); 420 DwarfStrSection = 421 Ctx->getELFSection(".debug_str", DebugSecType, 422 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 423 DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0); 424 DwarfARangesSection = 425 Ctx->getELFSection(".debug_aranges", DebugSecType, 0); 426 DwarfRangesSection = 427 Ctx->getELFSection(".debug_ranges", DebugSecType, 0); 428 DwarfMacinfoSection = 429 Ctx->getELFSection(".debug_macinfo", DebugSecType, 0); 430 431 // DWARF5 Experimental Debug Info 432 433 // Accelerator Tables 434 DwarfDebugNamesSection = 435 Ctx->getELFSection(".debug_names", ELF::SHT_PROGBITS, 0); 436 DwarfAccelNamesSection = 437 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0); 438 DwarfAccelObjCSection = 439 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0); 440 DwarfAccelNamespaceSection = 441 Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0); 442 DwarfAccelTypesSection = 443 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0); 444 445 // String Offset and Address Sections 446 DwarfStrOffSection = 447 Ctx->getELFSection(".debug_str_offsets", DebugSecType, 0); 448 DwarfAddrSection = Ctx->getELFSection(".debug_addr", DebugSecType, 0); 449 DwarfRnglistsSection = Ctx->getELFSection(".debug_rnglists", DebugSecType, 0); 450 DwarfLoclistsSection = Ctx->getELFSection(".debug_loclists", DebugSecType, 0); 451 452 // Fission Sections 453 DwarfInfoDWOSection = 454 Ctx->getELFSection(".debug_info.dwo", DebugSecType, ELF::SHF_EXCLUDE); 455 DwarfTypesDWOSection = 456 Ctx->getELFSection(".debug_types.dwo", DebugSecType, ELF::SHF_EXCLUDE); 457 DwarfAbbrevDWOSection = 458 Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, ELF::SHF_EXCLUDE); 459 DwarfStrDWOSection = Ctx->getELFSection( 460 ".debug_str.dwo", DebugSecType, 461 ELF::SHF_MERGE | ELF::SHF_STRINGS | ELF::SHF_EXCLUDE, 1, ""); 462 DwarfLineDWOSection = 463 Ctx->getELFSection(".debug_line.dwo", DebugSecType, ELF::SHF_EXCLUDE); 464 DwarfLocDWOSection = 465 Ctx->getELFSection(".debug_loc.dwo", DebugSecType, ELF::SHF_EXCLUDE); 466 DwarfStrOffDWOSection = Ctx->getELFSection(".debug_str_offsets.dwo", 467 DebugSecType, ELF::SHF_EXCLUDE); 468 DwarfRnglistsDWOSection = 469 Ctx->getELFSection(".debug_rnglists.dwo", DebugSecType, ELF::SHF_EXCLUDE); 470 471 // DWP Sections 472 DwarfCUIndexSection = 473 Ctx->getELFSection(".debug_cu_index", DebugSecType, 0); 474 DwarfTUIndexSection = 475 Ctx->getELFSection(".debug_tu_index", DebugSecType, 0); 476 477 StackMapSection = 478 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 479 480 FaultMapSection = 481 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 482 483 EHFrameSection = 484 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags); 485 486 StackSizesSection = Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, 0); 487 488 RemarksSection = 489 Ctx->getELFSection(".remarks", ELF::SHT_PROGBITS, ELF::SHF_EXCLUDE); 490 } 491 492 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) { 493 EHFrameSection = 494 Ctx->getCOFFSection(".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 495 COFF::IMAGE_SCN_MEM_READ, 496 SectionKind::getData()); 497 498 // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode. This is 499 // used to indicate to the linker that the text segment contains thumb instructions 500 // and to set the ISA selection bit for calls accordingly. 501 const bool IsThumb = T.getArch() == Triple::thumb; 502 503 CommDirectiveSupportsAlignment = true; 504 505 // COFF 506 BSSSection = Ctx->getCOFFSection( 507 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | 508 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 509 SectionKind::getBSS()); 510 TextSection = Ctx->getCOFFSection( 511 ".text", 512 (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) | 513 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE | 514 COFF::IMAGE_SCN_MEM_READ, 515 SectionKind::getText()); 516 DataSection = Ctx->getCOFFSection( 517 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 518 COFF::IMAGE_SCN_MEM_WRITE, 519 SectionKind::getData()); 520 ReadOnlySection = Ctx->getCOFFSection( 521 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 522 SectionKind::getReadOnly()); 523 524 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::aarch64) { 525 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section 526 LSDASection = nullptr; 527 } else { 528 LSDASection = Ctx->getCOFFSection(".gcc_except_table", 529 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 530 COFF::IMAGE_SCN_MEM_READ, 531 SectionKind::getReadOnly()); 532 } 533 534 // Debug info. 535 COFFDebugSymbolsSection = 536 Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 537 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 538 COFF::IMAGE_SCN_MEM_READ), 539 SectionKind::getMetadata()); 540 COFFDebugTypesSection = 541 Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 542 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 543 COFF::IMAGE_SCN_MEM_READ), 544 SectionKind::getMetadata()); 545 COFFGlobalTypeHashesSection = Ctx->getCOFFSection( 546 ".debug$H", 547 (COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 548 COFF::IMAGE_SCN_MEM_READ), 549 SectionKind::getMetadata()); 550 551 DwarfAbbrevSection = Ctx->getCOFFSection( 552 ".debug_abbrev", 553 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 554 COFF::IMAGE_SCN_MEM_READ, 555 SectionKind::getMetadata(), "section_abbrev"); 556 DwarfInfoSection = Ctx->getCOFFSection( 557 ".debug_info", 558 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 559 COFF::IMAGE_SCN_MEM_READ, 560 SectionKind::getMetadata(), "section_info"); 561 DwarfLineSection = Ctx->getCOFFSection( 562 ".debug_line", 563 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 564 COFF::IMAGE_SCN_MEM_READ, 565 SectionKind::getMetadata(), "section_line"); 566 DwarfLineStrSection = Ctx->getCOFFSection( 567 ".debug_line_str", 568 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 569 COFF::IMAGE_SCN_MEM_READ, 570 SectionKind::getMetadata(), "section_line_str"); 571 DwarfFrameSection = Ctx->getCOFFSection( 572 ".debug_frame", 573 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 574 COFF::IMAGE_SCN_MEM_READ, 575 SectionKind::getMetadata()); 576 DwarfPubNamesSection = Ctx->getCOFFSection( 577 ".debug_pubnames", 578 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 579 COFF::IMAGE_SCN_MEM_READ, 580 SectionKind::getMetadata()); 581 DwarfPubTypesSection = Ctx->getCOFFSection( 582 ".debug_pubtypes", 583 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 584 COFF::IMAGE_SCN_MEM_READ, 585 SectionKind::getMetadata()); 586 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 587 ".debug_gnu_pubnames", 588 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 589 COFF::IMAGE_SCN_MEM_READ, 590 SectionKind::getMetadata()); 591 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 592 ".debug_gnu_pubtypes", 593 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 594 COFF::IMAGE_SCN_MEM_READ, 595 SectionKind::getMetadata()); 596 DwarfStrSection = Ctx->getCOFFSection( 597 ".debug_str", 598 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 599 COFF::IMAGE_SCN_MEM_READ, 600 SectionKind::getMetadata(), "info_string"); 601 DwarfStrOffSection = Ctx->getCOFFSection( 602 ".debug_str_offsets", 603 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 604 COFF::IMAGE_SCN_MEM_READ, 605 SectionKind::getMetadata(), "section_str_off"); 606 DwarfLocSection = Ctx->getCOFFSection( 607 ".debug_loc", 608 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 609 COFF::IMAGE_SCN_MEM_READ, 610 SectionKind::getMetadata(), "section_debug_loc"); 611 DwarfARangesSection = Ctx->getCOFFSection( 612 ".debug_aranges", 613 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 614 COFF::IMAGE_SCN_MEM_READ, 615 SectionKind::getMetadata()); 616 DwarfRangesSection = Ctx->getCOFFSection( 617 ".debug_ranges", 618 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 619 COFF::IMAGE_SCN_MEM_READ, 620 SectionKind::getMetadata(), "debug_range"); 621 DwarfMacinfoSection = Ctx->getCOFFSection( 622 ".debug_macinfo", 623 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 624 COFF::IMAGE_SCN_MEM_READ, 625 SectionKind::getMetadata(), "debug_macinfo"); 626 DwarfInfoDWOSection = Ctx->getCOFFSection( 627 ".debug_info.dwo", 628 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 629 COFF::IMAGE_SCN_MEM_READ, 630 SectionKind::getMetadata(), "section_info_dwo"); 631 DwarfTypesDWOSection = Ctx->getCOFFSection( 632 ".debug_types.dwo", 633 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 634 COFF::IMAGE_SCN_MEM_READ, 635 SectionKind::getMetadata(), "section_types_dwo"); 636 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 637 ".debug_abbrev.dwo", 638 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 639 COFF::IMAGE_SCN_MEM_READ, 640 SectionKind::getMetadata(), "section_abbrev_dwo"); 641 DwarfStrDWOSection = Ctx->getCOFFSection( 642 ".debug_str.dwo", 643 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 644 COFF::IMAGE_SCN_MEM_READ, 645 SectionKind::getMetadata(), "skel_string"); 646 DwarfLineDWOSection = Ctx->getCOFFSection( 647 ".debug_line.dwo", 648 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 649 COFF::IMAGE_SCN_MEM_READ, 650 SectionKind::getMetadata()); 651 DwarfLocDWOSection = Ctx->getCOFFSection( 652 ".debug_loc.dwo", 653 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 654 COFF::IMAGE_SCN_MEM_READ, 655 SectionKind::getMetadata(), "skel_loc"); 656 DwarfStrOffDWOSection = Ctx->getCOFFSection( 657 ".debug_str_offsets.dwo", 658 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 659 COFF::IMAGE_SCN_MEM_READ, 660 SectionKind::getMetadata(), "section_str_off_dwo"); 661 DwarfAddrSection = Ctx->getCOFFSection( 662 ".debug_addr", 663 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 664 COFF::IMAGE_SCN_MEM_READ, 665 SectionKind::getMetadata(), "addr_sec"); 666 DwarfCUIndexSection = Ctx->getCOFFSection( 667 ".debug_cu_index", 668 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 669 COFF::IMAGE_SCN_MEM_READ, 670 SectionKind::getMetadata()); 671 DwarfTUIndexSection = Ctx->getCOFFSection( 672 ".debug_tu_index", 673 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 674 COFF::IMAGE_SCN_MEM_READ, 675 SectionKind::getMetadata()); 676 DwarfDebugNamesSection = Ctx->getCOFFSection( 677 ".debug_names", 678 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 679 COFF::IMAGE_SCN_MEM_READ, 680 SectionKind::getMetadata(), "debug_names_begin"); 681 DwarfAccelNamesSection = Ctx->getCOFFSection( 682 ".apple_names", 683 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 684 COFF::IMAGE_SCN_MEM_READ, 685 SectionKind::getMetadata(), "names_begin"); 686 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 687 ".apple_namespaces", 688 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 689 COFF::IMAGE_SCN_MEM_READ, 690 SectionKind::getMetadata(), "namespac_begin"); 691 DwarfAccelTypesSection = Ctx->getCOFFSection( 692 ".apple_types", 693 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 694 COFF::IMAGE_SCN_MEM_READ, 695 SectionKind::getMetadata(), "types_begin"); 696 DwarfAccelObjCSection = Ctx->getCOFFSection( 697 ".apple_objc", 698 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 699 COFF::IMAGE_SCN_MEM_READ, 700 SectionKind::getMetadata(), "objc_begin"); 701 702 DrectveSection = Ctx->getCOFFSection( 703 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 704 SectionKind::getMetadata()); 705 706 PDataSection = Ctx->getCOFFSection( 707 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 708 SectionKind::getData()); 709 710 XDataSection = Ctx->getCOFFSection( 711 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 712 SectionKind::getData()); 713 714 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 715 SectionKind::getMetadata()); 716 717 GFIDsSection = Ctx->getCOFFSection(".gfids$y", 718 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 719 COFF::IMAGE_SCN_MEM_READ, 720 SectionKind::getMetadata()); 721 722 TLSDataSection = Ctx->getCOFFSection( 723 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 724 COFF::IMAGE_SCN_MEM_WRITE, 725 SectionKind::getData()); 726 727 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 728 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 729 COFF::IMAGE_SCN_MEM_READ, 730 SectionKind::getReadOnly()); 731 } 732 733 void MCObjectFileInfo::initWasmMCObjectFileInfo(const Triple &T) { 734 TextSection = Ctx->getWasmSection(".text", SectionKind::getText()); 735 DataSection = Ctx->getWasmSection(".data", SectionKind::getData()); 736 737 DwarfLineSection = 738 Ctx->getWasmSection(".debug_line", SectionKind::getMetadata()); 739 DwarfLineStrSection = 740 Ctx->getWasmSection(".debug_line_str", SectionKind::getMetadata()); 741 DwarfStrSection = 742 Ctx->getWasmSection(".debug_str", SectionKind::getMetadata()); 743 DwarfLocSection = 744 Ctx->getWasmSection(".debug_loc", SectionKind::getMetadata()); 745 DwarfAbbrevSection = 746 Ctx->getWasmSection(".debug_abbrev", SectionKind::getMetadata()); 747 DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", SectionKind::getMetadata()); 748 DwarfRangesSection = 749 Ctx->getWasmSection(".debug_ranges", SectionKind::getMetadata()); 750 DwarfMacinfoSection = 751 Ctx->getWasmSection(".debug_macinfo", SectionKind::getMetadata()); 752 DwarfAddrSection = Ctx->getWasmSection(".debug_addr", SectionKind::getMetadata()); 753 DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", SectionKind::getMetadata()); 754 DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", SectionKind::getMetadata()); 755 DwarfInfoSection = 756 Ctx->getWasmSection(".debug_info", SectionKind::getMetadata()); 757 DwarfFrameSection = Ctx->getWasmSection(".debug_frame", SectionKind::getMetadata()); 758 DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", SectionKind::getMetadata()); 759 DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", SectionKind::getMetadata()); 760 761 // Wasm use data section for LSDA. 762 // TODO Consider putting each function's exception table in a separate 763 // section, as in -function-sections, to facilitate lld's --gc-section. 764 LSDASection = Ctx->getWasmSection(".rodata.gcc_except_table", 765 SectionKind::getReadOnlyWithRel()); 766 767 // TODO: Define more sections. 768 } 769 770 void MCObjectFileInfo::initXCOFFMCObjectFileInfo(const Triple &T) { 771 // The default csect for program code. Functions without a specified section 772 // get placed into this csect. The choice of csect name is not a property of 773 // the ABI or object file format. For example, the XL compiler uses an unnamed 774 // csect for program code. 775 TextSection = Ctx->getXCOFFSection( 776 ".text", XCOFF::StorageMappingClass::XMC_PR, SectionKind::getText()); 777 } 778 779 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC, 780 MCContext &ctx, 781 bool LargeCodeModel) { 782 PositionIndependent = PIC; 783 Ctx = &ctx; 784 785 // Common. 786 CommDirectiveSupportsAlignment = true; 787 SupportsWeakOmittedEHFrame = true; 788 SupportsCompactUnwindWithoutEHFrame = false; 789 OmitDwarfIfHaveCompactUnwind = false; 790 791 FDECFIEncoding = dwarf::DW_EH_PE_absptr; 792 793 CompactUnwindDwarfEHFrameOnly = 0; 794 795 EHFrameSection = nullptr; // Created on demand. 796 CompactUnwindSection = nullptr; // Used only by selected targets. 797 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 798 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 799 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 800 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 801 802 TT = TheTriple; 803 804 switch (TT.getObjectFormat()) { 805 case Triple::MachO: 806 Env = IsMachO; 807 initMachOMCObjectFileInfo(TT); 808 break; 809 case Triple::COFF: 810 if (!TT.isOSWindows()) 811 report_fatal_error( 812 "Cannot initialize MC for non-Windows COFF object files."); 813 814 Env = IsCOFF; 815 initCOFFMCObjectFileInfo(TT); 816 break; 817 case Triple::ELF: 818 Env = IsELF; 819 initELFMCObjectFileInfo(TT, LargeCodeModel); 820 break; 821 case Triple::Wasm: 822 Env = IsWasm; 823 initWasmMCObjectFileInfo(TT); 824 break; 825 case Triple::XCOFF: 826 Env = IsXCOFF; 827 initXCOFFMCObjectFileInfo(TT); 828 break; 829 case Triple::UnknownObjectFormat: 830 report_fatal_error("Cannot initialize MC for unknown object file format."); 831 break; 832 } 833 } 834 835 MCSection *MCObjectFileInfo::getDwarfComdatSection(const char *Name, 836 uint64_t Hash) const { 837 switch (TT.getObjectFormat()) { 838 case Triple::ELF: 839 return Ctx->getELFSection(Name, ELF::SHT_PROGBITS, ELF::SHF_GROUP, 0, 840 utostr(Hash)); 841 case Triple::MachO: 842 case Triple::COFF: 843 case Triple::Wasm: 844 case Triple::XCOFF: 845 case Triple::UnknownObjectFormat: 846 report_fatal_error("Cannot get DWARF comdat section for this object file " 847 "format: not implemented."); 848 break; 849 } 850 llvm_unreachable("Unknown ObjectFormatType"); 851 } 852 853 MCSection * 854 MCObjectFileInfo::getStackSizesSection(const MCSection &TextSec) const { 855 if (Env != IsELF) 856 return StackSizesSection; 857 858 const MCSectionELF &ElfSec = static_cast<const MCSectionELF &>(TextSec); 859 unsigned Flags = ELF::SHF_LINK_ORDER; 860 StringRef GroupName; 861 if (const MCSymbol *Group = ElfSec.getGroup()) { 862 GroupName = Group->getName(); 863 Flags |= ELF::SHF_GROUP; 864 } 865 866 const MCSymbol *Link = TextSec.getBeginSymbol(); 867 auto It = StackSizesUniquing.insert({Link, StackSizesUniquing.size()}); 868 unsigned UniqueID = It.first->second; 869 870 return Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, Flags, 0, 871 GroupName, UniqueID, cast<MCSymbolELF>(Link)); 872 } 873