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