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 FDECFIEncoding = Ctx->getAsmInfo()->getCodePointerSize() == 4 308 ? dwarf::DW_EH_PE_sdata4 309 : dwarf::DW_EH_PE_sdata8; 310 break; 311 case Triple::ppc64: 312 case Triple::ppc64le: 313 case Triple::x86_64: 314 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | 315 (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4); 316 break; 317 case Triple::bpfel: 318 case Triple::bpfeb: 319 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 320 break; 321 case Triple::hexagon: 322 FDECFIEncoding = 323 PositionIndependent ? dwarf::DW_EH_PE_pcrel : dwarf::DW_EH_PE_absptr; 324 break; 325 default: 326 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 327 break; 328 } 329 330 unsigned EHSectionType = T.getArch() == Triple::x86_64 331 ? ELF::SHT_X86_64_UNWIND 332 : ELF::SHT_PROGBITS; 333 334 // Solaris requires different flags for .eh_frame to seemingly every other 335 // platform. 336 unsigned EHSectionFlags = ELF::SHF_ALLOC; 337 if (T.isOSSolaris() && T.getArch() != Triple::x86_64) 338 EHSectionFlags |= ELF::SHF_WRITE; 339 340 // ELF 341 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 342 ELF::SHF_WRITE | ELF::SHF_ALLOC); 343 344 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 345 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 346 347 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 348 ELF::SHF_WRITE | ELF::SHF_ALLOC); 349 350 ReadOnlySection = 351 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 352 353 TLSDataSection = 354 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 355 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 356 357 TLSBSSSection = Ctx->getELFSection( 358 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 359 360 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 361 ELF::SHF_ALLOC | ELF::SHF_WRITE); 362 363 MergeableConst4Section = 364 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 365 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, ""); 366 367 MergeableConst8Section = 368 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 369 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, ""); 370 371 MergeableConst16Section = 372 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 373 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, ""); 374 375 MergeableConst32Section = 376 Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS, 377 ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, ""); 378 379 // Exception Handling Sections. 380 381 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 382 // it contains relocatable pointers. In PIC mode, this is probably a big 383 // runtime hit for C++ apps. Either the contents of the LSDA need to be 384 // adjusted or this should be a data section. 385 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 386 ELF::SHF_ALLOC); 387 388 COFFDebugSymbolsSection = nullptr; 389 COFFDebugTypesSection = nullptr; 390 391 unsigned DebugSecType = ELF::SHT_PROGBITS; 392 393 // MIPS .debug_* sections should have SHT_MIPS_DWARF section type 394 // to distinguish among sections contain DWARF and ECOFF debug formats. 395 // Sections with ECOFF debug format are obsoleted and marked by SHT_PROGBITS. 396 if (T.isMIPS()) 397 DebugSecType = ELF::SHT_MIPS_DWARF; 398 399 // Debug Info Sections. 400 DwarfAbbrevSection = 401 Ctx->getELFSection(".debug_abbrev", DebugSecType, 0); 402 DwarfInfoSection = Ctx->getELFSection(".debug_info", DebugSecType, 0); 403 DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0); 404 DwarfLineStrSection = 405 Ctx->getELFSection(".debug_line_str", DebugSecType, 406 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 407 DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0); 408 DwarfPubNamesSection = 409 Ctx->getELFSection(".debug_pubnames", DebugSecType, 0); 410 DwarfPubTypesSection = 411 Ctx->getELFSection(".debug_pubtypes", DebugSecType, 0); 412 DwarfGnuPubNamesSection = 413 Ctx->getELFSection(".debug_gnu_pubnames", DebugSecType, 0); 414 DwarfGnuPubTypesSection = 415 Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0); 416 DwarfStrSection = 417 Ctx->getELFSection(".debug_str", DebugSecType, 418 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 419 DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0); 420 DwarfARangesSection = 421 Ctx->getELFSection(".debug_aranges", DebugSecType, 0); 422 DwarfRangesSection = 423 Ctx->getELFSection(".debug_ranges", DebugSecType, 0); 424 DwarfMacinfoSection = 425 Ctx->getELFSection(".debug_macinfo", DebugSecType, 0); 426 427 // DWARF5 Experimental Debug Info 428 429 // Accelerator Tables 430 DwarfDebugNamesSection = 431 Ctx->getELFSection(".debug_names", ELF::SHT_PROGBITS, 0); 432 DwarfAccelNamesSection = 433 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0); 434 DwarfAccelObjCSection = 435 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0); 436 DwarfAccelNamespaceSection = 437 Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0); 438 DwarfAccelTypesSection = 439 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0); 440 441 // String Offset and Address Sections 442 DwarfStrOffSection = 443 Ctx->getELFSection(".debug_str_offsets", DebugSecType, 0); 444 DwarfAddrSection = Ctx->getELFSection(".debug_addr", DebugSecType, 0); 445 DwarfRnglistsSection = Ctx->getELFSection(".debug_rnglists", DebugSecType, 0); 446 DwarfLoclistsSection = Ctx->getELFSection(".debug_loclists", DebugSecType, 0); 447 448 // Fission Sections 449 DwarfInfoDWOSection = 450 Ctx->getELFSection(".debug_info.dwo", DebugSecType, ELF::SHF_EXCLUDE); 451 DwarfTypesDWOSection = 452 Ctx->getELFSection(".debug_types.dwo", DebugSecType, ELF::SHF_EXCLUDE); 453 DwarfAbbrevDWOSection = 454 Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, ELF::SHF_EXCLUDE); 455 DwarfStrDWOSection = Ctx->getELFSection( 456 ".debug_str.dwo", DebugSecType, 457 ELF::SHF_MERGE | ELF::SHF_STRINGS | ELF::SHF_EXCLUDE, 1, ""); 458 DwarfLineDWOSection = 459 Ctx->getELFSection(".debug_line.dwo", DebugSecType, ELF::SHF_EXCLUDE); 460 DwarfLocDWOSection = 461 Ctx->getELFSection(".debug_loc.dwo", DebugSecType, ELF::SHF_EXCLUDE); 462 DwarfStrOffDWOSection = Ctx->getELFSection(".debug_str_offsets.dwo", 463 DebugSecType, ELF::SHF_EXCLUDE); 464 DwarfRnglistsDWOSection = 465 Ctx->getELFSection(".debug_rnglists.dwo", DebugSecType, ELF::SHF_EXCLUDE); 466 467 // DWP Sections 468 DwarfCUIndexSection = 469 Ctx->getELFSection(".debug_cu_index", DebugSecType, 0); 470 DwarfTUIndexSection = 471 Ctx->getELFSection(".debug_tu_index", DebugSecType, 0); 472 473 StackMapSection = 474 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 475 476 FaultMapSection = 477 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 478 479 EHFrameSection = 480 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags); 481 482 StackSizesSection = Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, 0); 483 } 484 485 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) { 486 EHFrameSection = 487 Ctx->getCOFFSection(".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 488 COFF::IMAGE_SCN_MEM_READ, 489 SectionKind::getData()); 490 491 // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode. This is 492 // used to indicate to the linker that the text segment contains thumb instructions 493 // and to set the ISA selection bit for calls accordingly. 494 const bool IsThumb = T.getArch() == Triple::thumb; 495 496 CommDirectiveSupportsAlignment = true; 497 498 // COFF 499 BSSSection = Ctx->getCOFFSection( 500 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | 501 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 502 SectionKind::getBSS()); 503 TextSection = Ctx->getCOFFSection( 504 ".text", 505 (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) | 506 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE | 507 COFF::IMAGE_SCN_MEM_READ, 508 SectionKind::getText()); 509 DataSection = Ctx->getCOFFSection( 510 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 511 COFF::IMAGE_SCN_MEM_WRITE, 512 SectionKind::getData()); 513 ReadOnlySection = Ctx->getCOFFSection( 514 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 515 SectionKind::getReadOnly()); 516 517 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::aarch64) { 518 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section 519 LSDASection = nullptr; 520 } else { 521 LSDASection = Ctx->getCOFFSection(".gcc_except_table", 522 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 523 COFF::IMAGE_SCN_MEM_READ, 524 SectionKind::getReadOnly()); 525 } 526 527 // Debug info. 528 COFFDebugSymbolsSection = 529 Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 530 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 531 COFF::IMAGE_SCN_MEM_READ), 532 SectionKind::getMetadata()); 533 COFFDebugTypesSection = 534 Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 535 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 536 COFF::IMAGE_SCN_MEM_READ), 537 SectionKind::getMetadata()); 538 COFFGlobalTypeHashesSection = Ctx->getCOFFSection( 539 ".debug$H", 540 (COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 541 COFF::IMAGE_SCN_MEM_READ), 542 SectionKind::getMetadata()); 543 544 DwarfAbbrevSection = Ctx->getCOFFSection( 545 ".debug_abbrev", 546 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 547 COFF::IMAGE_SCN_MEM_READ, 548 SectionKind::getMetadata(), "section_abbrev"); 549 DwarfInfoSection = Ctx->getCOFFSection( 550 ".debug_info", 551 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 552 COFF::IMAGE_SCN_MEM_READ, 553 SectionKind::getMetadata(), "section_info"); 554 DwarfLineSection = Ctx->getCOFFSection( 555 ".debug_line", 556 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 557 COFF::IMAGE_SCN_MEM_READ, 558 SectionKind::getMetadata(), "section_line"); 559 DwarfLineStrSection = Ctx->getCOFFSection( 560 ".debug_line_str", 561 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 562 COFF::IMAGE_SCN_MEM_READ, 563 SectionKind::getMetadata(), "section_line_str"); 564 DwarfFrameSection = Ctx->getCOFFSection( 565 ".debug_frame", 566 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 567 COFF::IMAGE_SCN_MEM_READ, 568 SectionKind::getMetadata()); 569 DwarfPubNamesSection = Ctx->getCOFFSection( 570 ".debug_pubnames", 571 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 572 COFF::IMAGE_SCN_MEM_READ, 573 SectionKind::getMetadata()); 574 DwarfPubTypesSection = Ctx->getCOFFSection( 575 ".debug_pubtypes", 576 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 577 COFF::IMAGE_SCN_MEM_READ, 578 SectionKind::getMetadata()); 579 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 580 ".debug_gnu_pubnames", 581 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 582 COFF::IMAGE_SCN_MEM_READ, 583 SectionKind::getMetadata()); 584 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 585 ".debug_gnu_pubtypes", 586 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 587 COFF::IMAGE_SCN_MEM_READ, 588 SectionKind::getMetadata()); 589 DwarfStrSection = Ctx->getCOFFSection( 590 ".debug_str", 591 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 592 COFF::IMAGE_SCN_MEM_READ, 593 SectionKind::getMetadata(), "info_string"); 594 DwarfStrOffSection = Ctx->getCOFFSection( 595 ".debug_str_offsets", 596 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 597 COFF::IMAGE_SCN_MEM_READ, 598 SectionKind::getMetadata(), "section_str_off"); 599 DwarfLocSection = Ctx->getCOFFSection( 600 ".debug_loc", 601 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 602 COFF::IMAGE_SCN_MEM_READ, 603 SectionKind::getMetadata(), "section_debug_loc"); 604 DwarfARangesSection = Ctx->getCOFFSection( 605 ".debug_aranges", 606 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 607 COFF::IMAGE_SCN_MEM_READ, 608 SectionKind::getMetadata()); 609 DwarfRangesSection = Ctx->getCOFFSection( 610 ".debug_ranges", 611 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 612 COFF::IMAGE_SCN_MEM_READ, 613 SectionKind::getMetadata(), "debug_range"); 614 DwarfMacinfoSection = Ctx->getCOFFSection( 615 ".debug_macinfo", 616 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 617 COFF::IMAGE_SCN_MEM_READ, 618 SectionKind::getMetadata(), "debug_macinfo"); 619 DwarfInfoDWOSection = Ctx->getCOFFSection( 620 ".debug_info.dwo", 621 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 622 COFF::IMAGE_SCN_MEM_READ, 623 SectionKind::getMetadata(), "section_info_dwo"); 624 DwarfTypesDWOSection = Ctx->getCOFFSection( 625 ".debug_types.dwo", 626 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 627 COFF::IMAGE_SCN_MEM_READ, 628 SectionKind::getMetadata(), "section_types_dwo"); 629 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 630 ".debug_abbrev.dwo", 631 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 632 COFF::IMAGE_SCN_MEM_READ, 633 SectionKind::getMetadata(), "section_abbrev_dwo"); 634 DwarfStrDWOSection = Ctx->getCOFFSection( 635 ".debug_str.dwo", 636 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 637 COFF::IMAGE_SCN_MEM_READ, 638 SectionKind::getMetadata(), "skel_string"); 639 DwarfLineDWOSection = Ctx->getCOFFSection( 640 ".debug_line.dwo", 641 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 642 COFF::IMAGE_SCN_MEM_READ, 643 SectionKind::getMetadata()); 644 DwarfLocDWOSection = Ctx->getCOFFSection( 645 ".debug_loc.dwo", 646 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 647 COFF::IMAGE_SCN_MEM_READ, 648 SectionKind::getMetadata(), "skel_loc"); 649 DwarfStrOffDWOSection = Ctx->getCOFFSection( 650 ".debug_str_offsets.dwo", 651 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 652 COFF::IMAGE_SCN_MEM_READ, 653 SectionKind::getMetadata(), "section_str_off_dwo"); 654 DwarfAddrSection = Ctx->getCOFFSection( 655 ".debug_addr", 656 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 657 COFF::IMAGE_SCN_MEM_READ, 658 SectionKind::getMetadata(), "addr_sec"); 659 DwarfCUIndexSection = Ctx->getCOFFSection( 660 ".debug_cu_index", 661 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 662 COFF::IMAGE_SCN_MEM_READ, 663 SectionKind::getMetadata()); 664 DwarfTUIndexSection = Ctx->getCOFFSection( 665 ".debug_tu_index", 666 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 667 COFF::IMAGE_SCN_MEM_READ, 668 SectionKind::getMetadata()); 669 DwarfDebugNamesSection = Ctx->getCOFFSection( 670 ".debug_names", 671 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 672 COFF::IMAGE_SCN_MEM_READ, 673 SectionKind::getMetadata(), "debug_names_begin"); 674 DwarfAccelNamesSection = Ctx->getCOFFSection( 675 ".apple_names", 676 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 677 COFF::IMAGE_SCN_MEM_READ, 678 SectionKind::getMetadata(), "names_begin"); 679 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 680 ".apple_namespaces", 681 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 682 COFF::IMAGE_SCN_MEM_READ, 683 SectionKind::getMetadata(), "namespac_begin"); 684 DwarfAccelTypesSection = Ctx->getCOFFSection( 685 ".apple_types", 686 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 687 COFF::IMAGE_SCN_MEM_READ, 688 SectionKind::getMetadata(), "types_begin"); 689 DwarfAccelObjCSection = Ctx->getCOFFSection( 690 ".apple_objc", 691 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 692 COFF::IMAGE_SCN_MEM_READ, 693 SectionKind::getMetadata(), "objc_begin"); 694 695 DrectveSection = Ctx->getCOFFSection( 696 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 697 SectionKind::getMetadata()); 698 699 PDataSection = Ctx->getCOFFSection( 700 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 701 SectionKind::getData()); 702 703 XDataSection = Ctx->getCOFFSection( 704 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 705 SectionKind::getData()); 706 707 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 708 SectionKind::getMetadata()); 709 710 GFIDsSection = Ctx->getCOFFSection(".gfids$y", 711 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 712 COFF::IMAGE_SCN_MEM_READ, 713 SectionKind::getMetadata()); 714 715 GLJMPSection = Ctx->getCOFFSection(".gljmp$y", 716 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 717 COFF::IMAGE_SCN_MEM_READ, 718 SectionKind::getMetadata()); 719 720 TLSDataSection = Ctx->getCOFFSection( 721 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 722 COFF::IMAGE_SCN_MEM_WRITE, 723 SectionKind::getData()); 724 725 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 726 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 727 COFF::IMAGE_SCN_MEM_READ, 728 SectionKind::getReadOnly()); 729 } 730 731 void MCObjectFileInfo::initWasmMCObjectFileInfo(const Triple &T) { 732 TextSection = Ctx->getWasmSection(".text", SectionKind::getText()); 733 DataSection = Ctx->getWasmSection(".data", SectionKind::getData()); 734 735 DwarfLineSection = 736 Ctx->getWasmSection(".debug_line", SectionKind::getMetadata()); 737 DwarfLineStrSection = 738 Ctx->getWasmSection(".debug_line_str", SectionKind::getMetadata()); 739 DwarfStrSection = 740 Ctx->getWasmSection(".debug_str", SectionKind::getMetadata()); 741 DwarfLocSection = 742 Ctx->getWasmSection(".debug_loc", SectionKind::getMetadata()); 743 DwarfAbbrevSection = 744 Ctx->getWasmSection(".debug_abbrev", SectionKind::getMetadata()); 745 DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", SectionKind::getMetadata()); 746 DwarfRangesSection = 747 Ctx->getWasmSection(".debug_ranges", SectionKind::getMetadata()); 748 DwarfMacinfoSection = 749 Ctx->getWasmSection(".debug_macinfo", SectionKind::getMetadata()); 750 DwarfAddrSection = Ctx->getWasmSection(".debug_addr", SectionKind::getMetadata()); 751 DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", SectionKind::getMetadata()); 752 DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", SectionKind::getMetadata()); 753 DwarfInfoSection = 754 Ctx->getWasmSection(".debug_info", SectionKind::getMetadata()); 755 DwarfFrameSection = Ctx->getWasmSection(".debug_frame", SectionKind::getMetadata()); 756 DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", SectionKind::getMetadata()); 757 DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", SectionKind::getMetadata()); 758 759 // Wasm use data section for LSDA. 760 // TODO Consider putting each function's exception table in a separate 761 // section, as in -function-sections, to facilitate lld's --gc-section. 762 LSDASection = Ctx->getWasmSection(".rodata.gcc_except_table", 763 SectionKind::getReadOnlyWithRel()); 764 765 // TODO: Define more sections. 766 } 767 768 void MCObjectFileInfo::initXCOFFMCObjectFileInfo(const Triple &T) { 769 // The default csect for program code. Functions without a specified section 770 // get placed into this csect. The choice of csect name is not a property of 771 // the ABI or object file format. For example, the XL compiler uses an unnamed 772 // csect for program code. 773 TextSection = Ctx->getXCOFFSection( 774 ".text", XCOFF::StorageMappingClass::XMC_PR, XCOFF::XTY_SD, 775 XCOFF::C_HIDEXT, SectionKind::getText()); 776 777 DataSection = Ctx->getXCOFFSection( 778 ".data", XCOFF::StorageMappingClass::XMC_RW, XCOFF::XTY_SD, 779 XCOFF::C_HIDEXT, SectionKind::getData()); 780 } 781 782 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC, 783 MCContext &ctx, 784 bool LargeCodeModel) { 785 PositionIndependent = PIC; 786 Ctx = &ctx; 787 788 // Common. 789 CommDirectiveSupportsAlignment = true; 790 SupportsWeakOmittedEHFrame = true; 791 SupportsCompactUnwindWithoutEHFrame = false; 792 OmitDwarfIfHaveCompactUnwind = false; 793 794 FDECFIEncoding = dwarf::DW_EH_PE_absptr; 795 796 CompactUnwindDwarfEHFrameOnly = 0; 797 798 EHFrameSection = nullptr; // Created on demand. 799 CompactUnwindSection = nullptr; // Used only by selected targets. 800 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 801 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 802 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 803 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 804 805 TT = TheTriple; 806 807 switch (TT.getObjectFormat()) { 808 case Triple::MachO: 809 Env = IsMachO; 810 initMachOMCObjectFileInfo(TT); 811 break; 812 case Triple::COFF: 813 if (!TT.isOSWindows()) 814 report_fatal_error( 815 "Cannot initialize MC for non-Windows COFF object files."); 816 817 Env = IsCOFF; 818 initCOFFMCObjectFileInfo(TT); 819 break; 820 case Triple::ELF: 821 Env = IsELF; 822 initELFMCObjectFileInfo(TT, LargeCodeModel); 823 break; 824 case Triple::Wasm: 825 Env = IsWasm; 826 initWasmMCObjectFileInfo(TT); 827 break; 828 case Triple::XCOFF: 829 Env = IsXCOFF; 830 initXCOFFMCObjectFileInfo(TT); 831 break; 832 case Triple::UnknownObjectFormat: 833 report_fatal_error("Cannot initialize MC for unknown object file format."); 834 break; 835 } 836 } 837 838 MCSection *MCObjectFileInfo::getDwarfComdatSection(const char *Name, 839 uint64_t Hash) const { 840 switch (TT.getObjectFormat()) { 841 case Triple::ELF: 842 return Ctx->getELFSection(Name, ELF::SHT_PROGBITS, ELF::SHF_GROUP, 0, 843 utostr(Hash)); 844 case Triple::MachO: 845 case Triple::COFF: 846 case Triple::Wasm: 847 case Triple::XCOFF: 848 case Triple::UnknownObjectFormat: 849 report_fatal_error("Cannot get DWARF comdat section for this object file " 850 "format: not implemented."); 851 break; 852 } 853 llvm_unreachable("Unknown ObjectFormatType"); 854 } 855 856 MCSection * 857 MCObjectFileInfo::getStackSizesSection(const MCSection &TextSec) const { 858 if (Env != IsELF) 859 return StackSizesSection; 860 861 const MCSectionELF &ElfSec = static_cast<const MCSectionELF &>(TextSec); 862 unsigned Flags = ELF::SHF_LINK_ORDER; 863 StringRef GroupName; 864 if (const MCSymbol *Group = ElfSec.getGroup()) { 865 GroupName = Group->getName(); 866 Flags |= ELF::SHF_GROUP; 867 } 868 869 const MCSymbol *Link = TextSec.getBeginSymbol(); 870 auto It = StackSizesUniquing.insert({Link, StackSizesUniquing.size()}); 871 unsigned UniqueID = It.first->second; 872 873 return Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, Flags, 0, 874 GroupName, UniqueID, cast<MCSymbolELF>(Link)); 875 } 876