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 || T.getArch() == Triple::aarch64_32) 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() && 61 (T.getArch() == Triple::aarch64 || T.getArch() == Triple::aarch64_32)) 62 SupportsCompactUnwindWithoutEHFrame = true; 63 64 if (T.isWatchABI()) 65 OmitDwarfIfHaveCompactUnwind = true; 66 67 FDECFIEncoding = dwarf::DW_EH_PE_pcrel; 68 69 // .comm doesn't support alignment before Leopard. 70 if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5)) 71 CommDirectiveSupportsAlignment = false; 72 73 TextSection // .text 74 = Ctx->getMachOSection("__TEXT", "__text", 75 MachO::S_ATTR_PURE_INSTRUCTIONS, 76 SectionKind::getText()); 77 DataSection // .data 78 = Ctx->getMachOSection("__DATA", "__data", 0, SectionKind::getData()); 79 80 // BSSSection might not be expected initialized on msvc. 81 BSSSection = nullptr; 82 83 TLSDataSection // .tdata 84 = Ctx->getMachOSection("__DATA", "__thread_data", 85 MachO::S_THREAD_LOCAL_REGULAR, 86 SectionKind::getData()); 87 TLSBSSSection // .tbss 88 = Ctx->getMachOSection("__DATA", "__thread_bss", 89 MachO::S_THREAD_LOCAL_ZEROFILL, 90 SectionKind::getThreadBSS()); 91 92 // TODO: Verify datarel below. 93 TLSTLVSection // .tlv 94 = Ctx->getMachOSection("__DATA", "__thread_vars", 95 MachO::S_THREAD_LOCAL_VARIABLES, 96 SectionKind::getData()); 97 98 TLSThreadInitSection = Ctx->getMachOSection( 99 "__DATA", "__thread_init", MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS, 100 SectionKind::getData()); 101 102 CStringSection // .cstring 103 = Ctx->getMachOSection("__TEXT", "__cstring", 104 MachO::S_CSTRING_LITERALS, 105 SectionKind::getMergeable1ByteCString()); 106 UStringSection 107 = Ctx->getMachOSection("__TEXT","__ustring", 0, 108 SectionKind::getMergeable2ByteCString()); 109 FourByteConstantSection // .literal4 110 = Ctx->getMachOSection("__TEXT", "__literal4", 111 MachO::S_4BYTE_LITERALS, 112 SectionKind::getMergeableConst4()); 113 EightByteConstantSection // .literal8 114 = Ctx->getMachOSection("__TEXT", "__literal8", 115 MachO::S_8BYTE_LITERALS, 116 SectionKind::getMergeableConst8()); 117 118 SixteenByteConstantSection // .literal16 119 = Ctx->getMachOSection("__TEXT", "__literal16", 120 MachO::S_16BYTE_LITERALS, 121 SectionKind::getMergeableConst16()); 122 123 ReadOnlySection // .const 124 = Ctx->getMachOSection("__TEXT", "__const", 0, 125 SectionKind::getReadOnly()); 126 127 // If the target is not powerpc, map the coal sections to the non-coal 128 // sections. 129 // 130 // "__TEXT/__textcoal_nt" => section "__TEXT/__text" 131 // "__TEXT/__const_coal" => section "__TEXT/__const" 132 // "__DATA/__datacoal_nt" => section "__DATA/__data" 133 Triple::ArchType ArchTy = T.getArch(); 134 135 ConstDataSection // .const_data 136 = Ctx->getMachOSection("__DATA", "__const", 0, 137 SectionKind::getReadOnlyWithRel()); 138 139 if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) { 140 TextCoalSection 141 = Ctx->getMachOSection("__TEXT", "__textcoal_nt", 142 MachO::S_COALESCED | 143 MachO::S_ATTR_PURE_INSTRUCTIONS, 144 SectionKind::getText()); 145 ConstTextCoalSection 146 = Ctx->getMachOSection("__TEXT", "__const_coal", 147 MachO::S_COALESCED, 148 SectionKind::getReadOnly()); 149 DataCoalSection = Ctx->getMachOSection( 150 "__DATA", "__datacoal_nt", MachO::S_COALESCED, SectionKind::getData()); 151 ConstDataCoalSection = DataCoalSection; 152 } else { 153 TextCoalSection = TextSection; 154 ConstTextCoalSection = ReadOnlySection; 155 DataCoalSection = DataSection; 156 ConstDataCoalSection = ConstDataSection; 157 } 158 159 DataCommonSection 160 = Ctx->getMachOSection("__DATA","__common", 161 MachO::S_ZEROFILL, 162 SectionKind::getBSS()); 163 DataBSSSection 164 = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL, 165 SectionKind::getBSS()); 166 167 168 LazySymbolPointerSection 169 = Ctx->getMachOSection("__DATA", "__la_symbol_ptr", 170 MachO::S_LAZY_SYMBOL_POINTERS, 171 SectionKind::getMetadata()); 172 NonLazySymbolPointerSection 173 = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr", 174 MachO::S_NON_LAZY_SYMBOL_POINTERS, 175 SectionKind::getMetadata()); 176 177 ThreadLocalPointerSection 178 = Ctx->getMachOSection("__DATA", "__thread_ptr", 179 MachO::S_THREAD_LOCAL_VARIABLE_POINTERS, 180 SectionKind::getMetadata()); 181 182 // Exception Handling. 183 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0, 184 SectionKind::getReadOnlyWithRel()); 185 186 COFFDebugSymbolsSection = nullptr; 187 COFFDebugTypesSection = nullptr; 188 COFFGlobalTypeHashesSection = nullptr; 189 190 if (useCompactUnwind(T)) { 191 CompactUnwindSection = 192 Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG, 193 SectionKind::getReadOnly()); 194 195 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86) 196 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_X86_64_MODE_DWARF 197 else if (T.getArch() == Triple::aarch64 || T.getArch() == Triple::aarch64_32) 198 CompactUnwindDwarfEHFrameOnly = 0x03000000; // UNWIND_ARM64_MODE_DWARF 199 else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb) 200 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_ARM_MODE_DWARF 201 } 202 203 // Debug Information. 204 DwarfDebugNamesSection = 205 Ctx->getMachOSection("__DWARF", "__debug_names", MachO::S_ATTR_DEBUG, 206 SectionKind::getMetadata(), "debug_names_begin"); 207 DwarfAccelNamesSection = 208 Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG, 209 SectionKind::getMetadata(), "names_begin"); 210 DwarfAccelObjCSection = 211 Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG, 212 SectionKind::getMetadata(), "objc_begin"); 213 // 16 character section limit... 214 DwarfAccelNamespaceSection = 215 Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG, 216 SectionKind::getMetadata(), "namespac_begin"); 217 DwarfAccelTypesSection = 218 Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG, 219 SectionKind::getMetadata(), "types_begin"); 220 221 DwarfSwiftASTSection = 222 Ctx->getMachOSection("__DWARF", "__swift_ast", MachO::S_ATTR_DEBUG, 223 SectionKind::getMetadata()); 224 225 DwarfAbbrevSection = 226 Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG, 227 SectionKind::getMetadata(), "section_abbrev"); 228 DwarfInfoSection = 229 Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG, 230 SectionKind::getMetadata(), "section_info"); 231 DwarfLineSection = 232 Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG, 233 SectionKind::getMetadata(), "section_line"); 234 DwarfLineStrSection = 235 Ctx->getMachOSection("__DWARF", "__debug_line_str", MachO::S_ATTR_DEBUG, 236 SectionKind::getMetadata(), "section_line_str"); 237 DwarfFrameSection = 238 Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG, 239 SectionKind::getMetadata()); 240 DwarfPubNamesSection = 241 Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG, 242 SectionKind::getMetadata()); 243 DwarfPubTypesSection = 244 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG, 245 SectionKind::getMetadata()); 246 DwarfGnuPubNamesSection = 247 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG, 248 SectionKind::getMetadata()); 249 DwarfGnuPubTypesSection = 250 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG, 251 SectionKind::getMetadata()); 252 DwarfStrSection = 253 Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG, 254 SectionKind::getMetadata(), "info_string"); 255 DwarfStrOffSection = 256 Ctx->getMachOSection("__DWARF", "__debug_str_offs", MachO::S_ATTR_DEBUG, 257 SectionKind::getMetadata(), "section_str_off"); 258 DwarfAddrSection = 259 Ctx->getMachOSection("__DWARF", "__debug_addr", MachO::S_ATTR_DEBUG, 260 SectionKind::getMetadata(), "section_info"); 261 DwarfLocSection = 262 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG, 263 SectionKind::getMetadata(), "section_debug_loc"); 264 DwarfLoclistsSection = 265 Ctx->getMachOSection("__DWARF", "__debug_loclists", MachO::S_ATTR_DEBUG, 266 SectionKind::getMetadata(), "section_debug_loc"); 267 268 DwarfARangesSection = 269 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG, 270 SectionKind::getMetadata()); 271 DwarfRangesSection = 272 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG, 273 SectionKind::getMetadata(), "debug_range"); 274 DwarfRnglistsSection = 275 Ctx->getMachOSection("__DWARF", "__debug_rnglists", MachO::S_ATTR_DEBUG, 276 SectionKind::getMetadata(), "debug_range"); 277 DwarfMacinfoSection = 278 Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG, 279 SectionKind::getMetadata(), "debug_macinfo"); 280 DwarfDebugInlineSection = 281 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG, 282 SectionKind::getMetadata()); 283 DwarfCUIndexSection = 284 Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG, 285 SectionKind::getMetadata()); 286 DwarfTUIndexSection = 287 Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG, 288 SectionKind::getMetadata()); 289 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 290 0, SectionKind::getMetadata()); 291 292 FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps", 293 0, SectionKind::getMetadata()); 294 295 RemarksSection = Ctx->getMachOSection( 296 "__LLVM", "__remarks", MachO::S_ATTR_DEBUG, SectionKind::getMetadata()); 297 298 TLSExtraDataSection = TLSTLVSection; 299 } 300 301 void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) { 302 switch (T.getArch()) { 303 case Triple::mips: 304 case Triple::mipsel: 305 case Triple::mips64: 306 case Triple::mips64el: 307 // We cannot use DW_EH_PE_sdata8 for the large PositionIndependent case 308 // since there is no R_MIPS_PC64 relocation (only a 32-bit version). 309 if (PositionIndependent && !Large) 310 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 311 else 312 FDECFIEncoding = Ctx->getAsmInfo()->getCodePointerSize() == 4 313 ? dwarf::DW_EH_PE_sdata4 314 : dwarf::DW_EH_PE_sdata8; 315 break; 316 case Triple::ppc64: 317 case Triple::ppc64le: 318 case Triple::x86_64: 319 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | 320 (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4); 321 break; 322 case Triple::bpfel: 323 case Triple::bpfeb: 324 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 325 break; 326 case Triple::hexagon: 327 FDECFIEncoding = 328 PositionIndependent ? dwarf::DW_EH_PE_pcrel : dwarf::DW_EH_PE_absptr; 329 break; 330 default: 331 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 332 break; 333 } 334 335 unsigned EHSectionType = T.getArch() == Triple::x86_64 336 ? ELF::SHT_X86_64_UNWIND 337 : ELF::SHT_PROGBITS; 338 339 // Solaris requires different flags for .eh_frame to seemingly every other 340 // platform. 341 unsigned EHSectionFlags = ELF::SHF_ALLOC; 342 if (T.isOSSolaris() && T.getArch() != Triple::x86_64) 343 EHSectionFlags |= ELF::SHF_WRITE; 344 345 // ELF 346 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 347 ELF::SHF_WRITE | ELF::SHF_ALLOC); 348 349 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 350 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 351 352 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 353 ELF::SHF_WRITE | ELF::SHF_ALLOC); 354 355 ReadOnlySection = 356 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 357 358 TLSDataSection = 359 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 360 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 361 362 TLSBSSSection = Ctx->getELFSection( 363 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 364 365 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 366 ELF::SHF_ALLOC | ELF::SHF_WRITE); 367 368 MergeableConst4Section = 369 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 370 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, ""); 371 372 MergeableConst8Section = 373 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 374 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, ""); 375 376 MergeableConst16Section = 377 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 378 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, ""); 379 380 MergeableConst32Section = 381 Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS, 382 ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, ""); 383 384 // Exception Handling Sections. 385 386 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 387 // it contains relocatable pointers. In PIC mode, this is probably a big 388 // runtime hit for C++ apps. Either the contents of the LSDA need to be 389 // adjusted or this should be a data section. 390 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 391 ELF::SHF_ALLOC); 392 393 COFFDebugSymbolsSection = nullptr; 394 COFFDebugTypesSection = nullptr; 395 396 unsigned DebugSecType = ELF::SHT_PROGBITS; 397 398 // MIPS .debug_* sections should have SHT_MIPS_DWARF section type 399 // to distinguish among sections contain DWARF and ECOFF debug formats. 400 // Sections with ECOFF debug format are obsoleted and marked by SHT_PROGBITS. 401 if (T.isMIPS()) 402 DebugSecType = ELF::SHT_MIPS_DWARF; 403 404 // Debug Info Sections. 405 DwarfAbbrevSection = 406 Ctx->getELFSection(".debug_abbrev", DebugSecType, 0); 407 DwarfInfoSection = Ctx->getELFSection(".debug_info", DebugSecType, 0); 408 DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0); 409 DwarfLineStrSection = 410 Ctx->getELFSection(".debug_line_str", DebugSecType, 411 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 412 DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0); 413 DwarfPubNamesSection = 414 Ctx->getELFSection(".debug_pubnames", DebugSecType, 0); 415 DwarfPubTypesSection = 416 Ctx->getELFSection(".debug_pubtypes", DebugSecType, 0); 417 DwarfGnuPubNamesSection = 418 Ctx->getELFSection(".debug_gnu_pubnames", DebugSecType, 0); 419 DwarfGnuPubTypesSection = 420 Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0); 421 DwarfStrSection = 422 Ctx->getELFSection(".debug_str", DebugSecType, 423 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 424 DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0); 425 DwarfARangesSection = 426 Ctx->getELFSection(".debug_aranges", DebugSecType, 0); 427 DwarfRangesSection = 428 Ctx->getELFSection(".debug_ranges", DebugSecType, 0); 429 DwarfMacinfoSection = 430 Ctx->getELFSection(".debug_macinfo", DebugSecType, 0); 431 432 // DWARF5 Experimental Debug Info 433 434 // Accelerator Tables 435 DwarfDebugNamesSection = 436 Ctx->getELFSection(".debug_names", ELF::SHT_PROGBITS, 0); 437 DwarfAccelNamesSection = 438 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0); 439 DwarfAccelObjCSection = 440 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0); 441 DwarfAccelNamespaceSection = 442 Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0); 443 DwarfAccelTypesSection = 444 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0); 445 446 // String Offset and Address Sections 447 DwarfStrOffSection = 448 Ctx->getELFSection(".debug_str_offsets", DebugSecType, 0); 449 DwarfAddrSection = Ctx->getELFSection(".debug_addr", DebugSecType, 0); 450 DwarfRnglistsSection = Ctx->getELFSection(".debug_rnglists", DebugSecType, 0); 451 DwarfLoclistsSection = Ctx->getELFSection(".debug_loclists", DebugSecType, 0); 452 453 // Fission Sections 454 DwarfInfoDWOSection = 455 Ctx->getELFSection(".debug_info.dwo", DebugSecType, ELF::SHF_EXCLUDE); 456 DwarfTypesDWOSection = 457 Ctx->getELFSection(".debug_types.dwo", DebugSecType, ELF::SHF_EXCLUDE); 458 DwarfAbbrevDWOSection = 459 Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, ELF::SHF_EXCLUDE); 460 DwarfStrDWOSection = Ctx->getELFSection( 461 ".debug_str.dwo", DebugSecType, 462 ELF::SHF_MERGE | ELF::SHF_STRINGS | ELF::SHF_EXCLUDE, 1, ""); 463 DwarfLineDWOSection = 464 Ctx->getELFSection(".debug_line.dwo", DebugSecType, ELF::SHF_EXCLUDE); 465 DwarfLocDWOSection = 466 Ctx->getELFSection(".debug_loc.dwo", DebugSecType, ELF::SHF_EXCLUDE); 467 DwarfStrOffDWOSection = Ctx->getELFSection(".debug_str_offsets.dwo", 468 DebugSecType, ELF::SHF_EXCLUDE); 469 DwarfRnglistsDWOSection = 470 Ctx->getELFSection(".debug_rnglists.dwo", DebugSecType, ELF::SHF_EXCLUDE); 471 472 // DWP Sections 473 DwarfCUIndexSection = 474 Ctx->getELFSection(".debug_cu_index", DebugSecType, 0); 475 DwarfTUIndexSection = 476 Ctx->getELFSection(".debug_tu_index", DebugSecType, 0); 477 478 StackMapSection = 479 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 480 481 FaultMapSection = 482 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 483 484 EHFrameSection = 485 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags); 486 487 StackSizesSection = Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, 0); 488 489 RemarksSection = 490 Ctx->getELFSection(".remarks", ELF::SHT_PROGBITS, ELF::SHF_EXCLUDE); 491 } 492 493 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) { 494 EHFrameSection = 495 Ctx->getCOFFSection(".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 496 COFF::IMAGE_SCN_MEM_READ, 497 SectionKind::getData()); 498 499 // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode. This is 500 // used to indicate to the linker that the text segment contains thumb instructions 501 // and to set the ISA selection bit for calls accordingly. 502 const bool IsThumb = T.getArch() == Triple::thumb; 503 504 CommDirectiveSupportsAlignment = true; 505 506 // COFF 507 BSSSection = Ctx->getCOFFSection( 508 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | 509 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 510 SectionKind::getBSS()); 511 TextSection = Ctx->getCOFFSection( 512 ".text", 513 (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) | 514 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE | 515 COFF::IMAGE_SCN_MEM_READ, 516 SectionKind::getText()); 517 DataSection = Ctx->getCOFFSection( 518 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 519 COFF::IMAGE_SCN_MEM_WRITE, 520 SectionKind::getData()); 521 ReadOnlySection = Ctx->getCOFFSection( 522 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 523 SectionKind::getReadOnly()); 524 525 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::aarch64) { 526 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section 527 LSDASection = nullptr; 528 } else { 529 LSDASection = Ctx->getCOFFSection(".gcc_except_table", 530 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 531 COFF::IMAGE_SCN_MEM_READ, 532 SectionKind::getReadOnly()); 533 } 534 535 // Debug info. 536 COFFDebugSymbolsSection = 537 Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 538 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 539 COFF::IMAGE_SCN_MEM_READ), 540 SectionKind::getMetadata()); 541 COFFDebugTypesSection = 542 Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 543 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 544 COFF::IMAGE_SCN_MEM_READ), 545 SectionKind::getMetadata()); 546 COFFGlobalTypeHashesSection = Ctx->getCOFFSection( 547 ".debug$H", 548 (COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 549 COFF::IMAGE_SCN_MEM_READ), 550 SectionKind::getMetadata()); 551 552 DwarfAbbrevSection = Ctx->getCOFFSection( 553 ".debug_abbrev", 554 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 555 COFF::IMAGE_SCN_MEM_READ, 556 SectionKind::getMetadata(), "section_abbrev"); 557 DwarfInfoSection = Ctx->getCOFFSection( 558 ".debug_info", 559 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 560 COFF::IMAGE_SCN_MEM_READ, 561 SectionKind::getMetadata(), "section_info"); 562 DwarfLineSection = Ctx->getCOFFSection( 563 ".debug_line", 564 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 565 COFF::IMAGE_SCN_MEM_READ, 566 SectionKind::getMetadata(), "section_line"); 567 DwarfLineStrSection = Ctx->getCOFFSection( 568 ".debug_line_str", 569 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 570 COFF::IMAGE_SCN_MEM_READ, 571 SectionKind::getMetadata(), "section_line_str"); 572 DwarfFrameSection = Ctx->getCOFFSection( 573 ".debug_frame", 574 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 575 COFF::IMAGE_SCN_MEM_READ, 576 SectionKind::getMetadata()); 577 DwarfPubNamesSection = Ctx->getCOFFSection( 578 ".debug_pubnames", 579 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 580 COFF::IMAGE_SCN_MEM_READ, 581 SectionKind::getMetadata()); 582 DwarfPubTypesSection = Ctx->getCOFFSection( 583 ".debug_pubtypes", 584 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 585 COFF::IMAGE_SCN_MEM_READ, 586 SectionKind::getMetadata()); 587 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 588 ".debug_gnu_pubnames", 589 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 590 COFF::IMAGE_SCN_MEM_READ, 591 SectionKind::getMetadata()); 592 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 593 ".debug_gnu_pubtypes", 594 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 595 COFF::IMAGE_SCN_MEM_READ, 596 SectionKind::getMetadata()); 597 DwarfStrSection = Ctx->getCOFFSection( 598 ".debug_str", 599 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 600 COFF::IMAGE_SCN_MEM_READ, 601 SectionKind::getMetadata(), "info_string"); 602 DwarfStrOffSection = Ctx->getCOFFSection( 603 ".debug_str_offsets", 604 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 605 COFF::IMAGE_SCN_MEM_READ, 606 SectionKind::getMetadata(), "section_str_off"); 607 DwarfLocSection = Ctx->getCOFFSection( 608 ".debug_loc", 609 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 610 COFF::IMAGE_SCN_MEM_READ, 611 SectionKind::getMetadata(), "section_debug_loc"); 612 DwarfARangesSection = Ctx->getCOFFSection( 613 ".debug_aranges", 614 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 615 COFF::IMAGE_SCN_MEM_READ, 616 SectionKind::getMetadata()); 617 DwarfRangesSection = Ctx->getCOFFSection( 618 ".debug_ranges", 619 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 620 COFF::IMAGE_SCN_MEM_READ, 621 SectionKind::getMetadata(), "debug_range"); 622 DwarfMacinfoSection = Ctx->getCOFFSection( 623 ".debug_macinfo", 624 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 625 COFF::IMAGE_SCN_MEM_READ, 626 SectionKind::getMetadata(), "debug_macinfo"); 627 DwarfInfoDWOSection = Ctx->getCOFFSection( 628 ".debug_info.dwo", 629 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 630 COFF::IMAGE_SCN_MEM_READ, 631 SectionKind::getMetadata(), "section_info_dwo"); 632 DwarfTypesDWOSection = Ctx->getCOFFSection( 633 ".debug_types.dwo", 634 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 635 COFF::IMAGE_SCN_MEM_READ, 636 SectionKind::getMetadata(), "section_types_dwo"); 637 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 638 ".debug_abbrev.dwo", 639 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 640 COFF::IMAGE_SCN_MEM_READ, 641 SectionKind::getMetadata(), "section_abbrev_dwo"); 642 DwarfStrDWOSection = Ctx->getCOFFSection( 643 ".debug_str.dwo", 644 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 645 COFF::IMAGE_SCN_MEM_READ, 646 SectionKind::getMetadata(), "skel_string"); 647 DwarfLineDWOSection = Ctx->getCOFFSection( 648 ".debug_line.dwo", 649 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 650 COFF::IMAGE_SCN_MEM_READ, 651 SectionKind::getMetadata()); 652 DwarfLocDWOSection = Ctx->getCOFFSection( 653 ".debug_loc.dwo", 654 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 655 COFF::IMAGE_SCN_MEM_READ, 656 SectionKind::getMetadata(), "skel_loc"); 657 DwarfStrOffDWOSection = Ctx->getCOFFSection( 658 ".debug_str_offsets.dwo", 659 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 660 COFF::IMAGE_SCN_MEM_READ, 661 SectionKind::getMetadata(), "section_str_off_dwo"); 662 DwarfAddrSection = Ctx->getCOFFSection( 663 ".debug_addr", 664 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 665 COFF::IMAGE_SCN_MEM_READ, 666 SectionKind::getMetadata(), "addr_sec"); 667 DwarfCUIndexSection = Ctx->getCOFFSection( 668 ".debug_cu_index", 669 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 670 COFF::IMAGE_SCN_MEM_READ, 671 SectionKind::getMetadata()); 672 DwarfTUIndexSection = Ctx->getCOFFSection( 673 ".debug_tu_index", 674 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 675 COFF::IMAGE_SCN_MEM_READ, 676 SectionKind::getMetadata()); 677 DwarfDebugNamesSection = Ctx->getCOFFSection( 678 ".debug_names", 679 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 680 COFF::IMAGE_SCN_MEM_READ, 681 SectionKind::getMetadata(), "debug_names_begin"); 682 DwarfAccelNamesSection = Ctx->getCOFFSection( 683 ".apple_names", 684 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 685 COFF::IMAGE_SCN_MEM_READ, 686 SectionKind::getMetadata(), "names_begin"); 687 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 688 ".apple_namespaces", 689 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 690 COFF::IMAGE_SCN_MEM_READ, 691 SectionKind::getMetadata(), "namespac_begin"); 692 DwarfAccelTypesSection = Ctx->getCOFFSection( 693 ".apple_types", 694 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 695 COFF::IMAGE_SCN_MEM_READ, 696 SectionKind::getMetadata(), "types_begin"); 697 DwarfAccelObjCSection = Ctx->getCOFFSection( 698 ".apple_objc", 699 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 700 COFF::IMAGE_SCN_MEM_READ, 701 SectionKind::getMetadata(), "objc_begin"); 702 703 DrectveSection = Ctx->getCOFFSection( 704 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 705 SectionKind::getMetadata()); 706 707 PDataSection = Ctx->getCOFFSection( 708 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 709 SectionKind::getData()); 710 711 XDataSection = Ctx->getCOFFSection( 712 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 713 SectionKind::getData()); 714 715 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 716 SectionKind::getMetadata()); 717 718 GFIDsSection = Ctx->getCOFFSection(".gfids$y", 719 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 720 COFF::IMAGE_SCN_MEM_READ, 721 SectionKind::getMetadata()); 722 723 TLSDataSection = Ctx->getCOFFSection( 724 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 725 COFF::IMAGE_SCN_MEM_WRITE, 726 SectionKind::getData()); 727 728 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 729 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 730 COFF::IMAGE_SCN_MEM_READ, 731 SectionKind::getReadOnly()); 732 } 733 734 void MCObjectFileInfo::initWasmMCObjectFileInfo(const Triple &T) { 735 TextSection = Ctx->getWasmSection(".text", SectionKind::getText()); 736 DataSection = Ctx->getWasmSection(".data", SectionKind::getData()); 737 738 DwarfLineSection = 739 Ctx->getWasmSection(".debug_line", SectionKind::getMetadata()); 740 DwarfLineStrSection = 741 Ctx->getWasmSection(".debug_line_str", SectionKind::getMetadata()); 742 DwarfStrSection = 743 Ctx->getWasmSection(".debug_str", SectionKind::getMetadata()); 744 DwarfLocSection = 745 Ctx->getWasmSection(".debug_loc", SectionKind::getMetadata()); 746 DwarfAbbrevSection = 747 Ctx->getWasmSection(".debug_abbrev", SectionKind::getMetadata()); 748 DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", SectionKind::getMetadata()); 749 DwarfRangesSection = 750 Ctx->getWasmSection(".debug_ranges", SectionKind::getMetadata()); 751 DwarfMacinfoSection = 752 Ctx->getWasmSection(".debug_macinfo", SectionKind::getMetadata()); 753 DwarfAddrSection = Ctx->getWasmSection(".debug_addr", SectionKind::getMetadata()); 754 DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", SectionKind::getMetadata()); 755 DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", SectionKind::getMetadata()); 756 DwarfInfoSection = 757 Ctx->getWasmSection(".debug_info", SectionKind::getMetadata()); 758 DwarfFrameSection = Ctx->getWasmSection(".debug_frame", SectionKind::getMetadata()); 759 DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", SectionKind::getMetadata()); 760 DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", SectionKind::getMetadata()); 761 762 // Wasm use data section for LSDA. 763 // TODO Consider putting each function's exception table in a separate 764 // section, as in -function-sections, to facilitate lld's --gc-section. 765 LSDASection = Ctx->getWasmSection(".rodata.gcc_except_table", 766 SectionKind::getReadOnlyWithRel()); 767 768 // TODO: Define more sections. 769 } 770 771 void MCObjectFileInfo::initXCOFFMCObjectFileInfo(const Triple &T) { 772 // The default csect for program code. Functions without a specified section 773 // get placed into this csect. The choice of csect name is not a property of 774 // the ABI or object file format. For example, the XL compiler uses an unnamed 775 // csect for program code. 776 TextSection = Ctx->getXCOFFSection( 777 ".text", XCOFF::StorageMappingClass::XMC_PR, XCOFF::XTY_SD, 778 XCOFF::C_HIDEXT, SectionKind::getText()); 779 780 DataSection = Ctx->getXCOFFSection( 781 ".data", XCOFF::StorageMappingClass::XMC_RW, XCOFF::XTY_SD, 782 XCOFF::C_HIDEXT, SectionKind::getData()); 783 } 784 785 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC, 786 MCContext &ctx, 787 bool LargeCodeModel) { 788 PositionIndependent = PIC; 789 Ctx = &ctx; 790 791 // Common. 792 CommDirectiveSupportsAlignment = true; 793 SupportsWeakOmittedEHFrame = true; 794 SupportsCompactUnwindWithoutEHFrame = false; 795 OmitDwarfIfHaveCompactUnwind = false; 796 797 FDECFIEncoding = dwarf::DW_EH_PE_absptr; 798 799 CompactUnwindDwarfEHFrameOnly = 0; 800 801 EHFrameSection = nullptr; // Created on demand. 802 CompactUnwindSection = nullptr; // Used only by selected targets. 803 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 804 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 805 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 806 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 807 808 TT = TheTriple; 809 810 switch (TT.getObjectFormat()) { 811 case Triple::MachO: 812 Env = IsMachO; 813 initMachOMCObjectFileInfo(TT); 814 break; 815 case Triple::COFF: 816 if (!TT.isOSWindows()) 817 report_fatal_error( 818 "Cannot initialize MC for non-Windows COFF object files."); 819 820 Env = IsCOFF; 821 initCOFFMCObjectFileInfo(TT); 822 break; 823 case Triple::ELF: 824 Env = IsELF; 825 initELFMCObjectFileInfo(TT, LargeCodeModel); 826 break; 827 case Triple::Wasm: 828 Env = IsWasm; 829 initWasmMCObjectFileInfo(TT); 830 break; 831 case Triple::XCOFF: 832 Env = IsXCOFF; 833 initXCOFFMCObjectFileInfo(TT); 834 break; 835 case Triple::UnknownObjectFormat: 836 report_fatal_error("Cannot initialize MC for unknown object file format."); 837 break; 838 } 839 } 840 841 MCSection *MCObjectFileInfo::getDwarfComdatSection(const char *Name, 842 uint64_t Hash) const { 843 switch (TT.getObjectFormat()) { 844 case Triple::ELF: 845 return Ctx->getELFSection(Name, ELF::SHT_PROGBITS, ELF::SHF_GROUP, 0, 846 utostr(Hash)); 847 case Triple::MachO: 848 case Triple::COFF: 849 case Triple::Wasm: 850 case Triple::XCOFF: 851 case Triple::UnknownObjectFormat: 852 report_fatal_error("Cannot get DWARF comdat section for this object file " 853 "format: not implemented."); 854 break; 855 } 856 llvm_unreachable("Unknown ObjectFormatType"); 857 } 858 859 MCSection * 860 MCObjectFileInfo::getStackSizesSection(const MCSection &TextSec) const { 861 if (Env != IsELF) 862 return StackSizesSection; 863 864 const MCSectionELF &ElfSec = static_cast<const MCSectionELF &>(TextSec); 865 unsigned Flags = ELF::SHF_LINK_ORDER; 866 StringRef GroupName; 867 if (const MCSymbol *Group = ElfSec.getGroup()) { 868 GroupName = Group->getName(); 869 Flags |= ELF::SHF_GROUP; 870 } 871 872 const MCSymbol *Link = TextSec.getBeginSymbol(); 873 auto It = StackSizesUniquing.insert({Link, StackSizesUniquing.size()}); 874 unsigned UniqueID = It.first->second; 875 876 return Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, Flags, 0, 877 GroupName, UniqueID, cast<MCSymbolELF>(Link)); 878 } 879