10b57cec5SDimitry Andric //===- InputFiles.cpp -----------------------------------------------------===// 20b57cec5SDimitry Andric // 30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 60b57cec5SDimitry Andric // 70b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 80b57cec5SDimitry Andric 90b57cec5SDimitry Andric #include "InputFiles.h" 1081ad6265SDimitry Andric #include "Config.h" 1181ad6265SDimitry Andric #include "DWARF.h" 120b57cec5SDimitry Andric #include "Driver.h" 130b57cec5SDimitry Andric #include "InputSection.h" 140b57cec5SDimitry Andric #include "LinkerScript.h" 150b57cec5SDimitry Andric #include "SymbolTable.h" 160b57cec5SDimitry Andric #include "Symbols.h" 170b57cec5SDimitry Andric #include "SyntheticSections.h" 181fd87a68SDimitry Andric #include "Target.h" 1904eeddc0SDimitry Andric #include "lld/Common/CommonLinkerContext.h" 20480093f4SDimitry Andric #include "lld/Common/DWARF.h" 2181ad6265SDimitry Andric #include "llvm/ADT/CachedHashString.h" 220b57cec5SDimitry Andric #include "llvm/ADT/STLExtras.h" 230b57cec5SDimitry Andric #include "llvm/LTO/LTO.h" 2481ad6265SDimitry Andric #include "llvm/Object/IRObjectFile.h" 250b57cec5SDimitry Andric #include "llvm/Support/ARMAttributeParser.h" 260b57cec5SDimitry Andric #include "llvm/Support/ARMBuildAttributes.h" 270b57cec5SDimitry Andric #include "llvm/Support/Endian.h" 2881ad6265SDimitry Andric #include "llvm/Support/FileSystem.h" 290b57cec5SDimitry Andric #include "llvm/Support/Path.h" 30e8d8bef9SDimitry Andric #include "llvm/Support/RISCVAttributeParser.h" 310b57cec5SDimitry Andric #include "llvm/Support/TarWriter.h" 320b57cec5SDimitry Andric #include "llvm/Support/raw_ostream.h" 330b57cec5SDimitry Andric 340b57cec5SDimitry Andric using namespace llvm; 350b57cec5SDimitry Andric using namespace llvm::ELF; 360b57cec5SDimitry Andric using namespace llvm::object; 370b57cec5SDimitry Andric using namespace llvm::sys; 380b57cec5SDimitry Andric using namespace llvm::sys::fs; 390b57cec5SDimitry Andric using namespace llvm::support::endian; 405ffd83dbSDimitry Andric using namespace lld; 415ffd83dbSDimitry Andric using namespace lld::elf; 420b57cec5SDimitry Andric 435ffd83dbSDimitry Andric bool InputFile::isInGroup; 445ffd83dbSDimitry Andric uint32_t InputFile::nextGroupId; 455ffd83dbSDimitry Andric 465ffd83dbSDimitry Andric std::unique_ptr<TarWriter> elf::tar; 475ffd83dbSDimitry Andric 4885868e8aSDimitry Andric // Returns "<internal>", "foo.a(bar.o)" or "baz.o". 495ffd83dbSDimitry Andric std::string lld::toString(const InputFile *f) { 50*bdd1243dSDimitry Andric static std::mutex mu; 5185868e8aSDimitry Andric if (!f) 5285868e8aSDimitry Andric return "<internal>"; 530b57cec5SDimitry Andric 54*bdd1243dSDimitry Andric { 55*bdd1243dSDimitry Andric std::lock_guard<std::mutex> lock(mu); 5685868e8aSDimitry Andric if (f->toStringCache.empty()) { 5785868e8aSDimitry Andric if (f->archiveName.empty()) 580eae32dcSDimitry Andric f->toStringCache = f->getName(); 5985868e8aSDimitry Andric else 600eae32dcSDimitry Andric (f->archiveName + "(" + f->getName() + ")").toVector(f->toStringCache); 6185868e8aSDimitry Andric } 62*bdd1243dSDimitry Andric } 630eae32dcSDimitry Andric return std::string(f->toStringCache); 6485868e8aSDimitry Andric } 6585868e8aSDimitry Andric 660b57cec5SDimitry Andric static ELFKind getELFKind(MemoryBufferRef mb, StringRef archiveName) { 670b57cec5SDimitry Andric unsigned char size; 680b57cec5SDimitry Andric unsigned char endian; 690b57cec5SDimitry Andric std::tie(size, endian) = getElfArchType(mb.getBuffer()); 700b57cec5SDimitry Andric 710b57cec5SDimitry Andric auto report = [&](StringRef msg) { 720b57cec5SDimitry Andric StringRef filename = mb.getBufferIdentifier(); 730b57cec5SDimitry Andric if (archiveName.empty()) 740b57cec5SDimitry Andric fatal(filename + ": " + msg); 750b57cec5SDimitry Andric else 760b57cec5SDimitry Andric fatal(archiveName + "(" + filename + "): " + msg); 770b57cec5SDimitry Andric }; 780b57cec5SDimitry Andric 790b57cec5SDimitry Andric if (!mb.getBuffer().startswith(ElfMagic)) 800b57cec5SDimitry Andric report("not an ELF file"); 810b57cec5SDimitry Andric if (endian != ELFDATA2LSB && endian != ELFDATA2MSB) 820b57cec5SDimitry Andric report("corrupted ELF file: invalid data encoding"); 830b57cec5SDimitry Andric if (size != ELFCLASS32 && size != ELFCLASS64) 840b57cec5SDimitry Andric report("corrupted ELF file: invalid file class"); 850b57cec5SDimitry Andric 860b57cec5SDimitry Andric size_t bufSize = mb.getBuffer().size(); 870b57cec5SDimitry Andric if ((size == ELFCLASS32 && bufSize < sizeof(Elf32_Ehdr)) || 880b57cec5SDimitry Andric (size == ELFCLASS64 && bufSize < sizeof(Elf64_Ehdr))) 890b57cec5SDimitry Andric report("corrupted ELF file: file is too short"); 900b57cec5SDimitry Andric 910b57cec5SDimitry Andric if (size == ELFCLASS32) 920b57cec5SDimitry Andric return (endian == ELFDATA2LSB) ? ELF32LEKind : ELF32BEKind; 930b57cec5SDimitry Andric return (endian == ELFDATA2LSB) ? ELF64LEKind : ELF64BEKind; 940b57cec5SDimitry Andric } 950b57cec5SDimitry Andric 96*bdd1243dSDimitry Andric // For ARM only, to set the EF_ARM_ABI_FLOAT_SOFT or EF_ARM_ABI_FLOAT_HARD 97*bdd1243dSDimitry Andric // flag in the ELF Header we need to look at Tag_ABI_VFP_args to find out how 98*bdd1243dSDimitry Andric // the input objects have been compiled. 99*bdd1243dSDimitry Andric static void updateARMVFPArgs(const ARMAttributeParser &attributes, 100*bdd1243dSDimitry Andric const InputFile *f) { 101*bdd1243dSDimitry Andric std::optional<unsigned> attr = 102*bdd1243dSDimitry Andric attributes.getAttributeValue(ARMBuildAttrs::ABI_VFP_args); 103*bdd1243dSDimitry Andric if (!attr) 104*bdd1243dSDimitry Andric // If an ABI tag isn't present then it is implicitly given the value of 0 105*bdd1243dSDimitry Andric // which maps to ARMBuildAttrs::BaseAAPCS. However many assembler files, 106*bdd1243dSDimitry Andric // including some in glibc that don't use FP args (and should have value 3) 107*bdd1243dSDimitry Andric // don't have the attribute so we do not consider an implicit value of 0 108*bdd1243dSDimitry Andric // as a clash. 109*bdd1243dSDimitry Andric return; 110*bdd1243dSDimitry Andric 111*bdd1243dSDimitry Andric unsigned vfpArgs = *attr; 112*bdd1243dSDimitry Andric ARMVFPArgKind arg; 113*bdd1243dSDimitry Andric switch (vfpArgs) { 114*bdd1243dSDimitry Andric case ARMBuildAttrs::BaseAAPCS: 115*bdd1243dSDimitry Andric arg = ARMVFPArgKind::Base; 116*bdd1243dSDimitry Andric break; 117*bdd1243dSDimitry Andric case ARMBuildAttrs::HardFPAAPCS: 118*bdd1243dSDimitry Andric arg = ARMVFPArgKind::VFP; 119*bdd1243dSDimitry Andric break; 120*bdd1243dSDimitry Andric case ARMBuildAttrs::ToolChainFPPCS: 121*bdd1243dSDimitry Andric // Tool chain specific convention that conforms to neither AAPCS variant. 122*bdd1243dSDimitry Andric arg = ARMVFPArgKind::ToolChain; 123*bdd1243dSDimitry Andric break; 124*bdd1243dSDimitry Andric case ARMBuildAttrs::CompatibleFPAAPCS: 125*bdd1243dSDimitry Andric // Object compatible with all conventions. 126*bdd1243dSDimitry Andric return; 127*bdd1243dSDimitry Andric default: 128*bdd1243dSDimitry Andric error(toString(f) + ": unknown Tag_ABI_VFP_args value: " + Twine(vfpArgs)); 129*bdd1243dSDimitry Andric return; 130*bdd1243dSDimitry Andric } 131*bdd1243dSDimitry Andric // Follow ld.bfd and error if there is a mix of calling conventions. 132*bdd1243dSDimitry Andric if (config->armVFPArgs != arg && config->armVFPArgs != ARMVFPArgKind::Default) 133*bdd1243dSDimitry Andric error(toString(f) + ": incompatible Tag_ABI_VFP_args"); 134*bdd1243dSDimitry Andric else 135*bdd1243dSDimitry Andric config->armVFPArgs = arg; 136*bdd1243dSDimitry Andric } 137*bdd1243dSDimitry Andric 138*bdd1243dSDimitry Andric // The ARM support in lld makes some use of instructions that are not available 139*bdd1243dSDimitry Andric // on all ARM architectures. Namely: 140*bdd1243dSDimitry Andric // - Use of BLX instruction for interworking between ARM and Thumb state. 141*bdd1243dSDimitry Andric // - Use of the extended Thumb branch encoding in relocation. 142*bdd1243dSDimitry Andric // - Use of the MOVT/MOVW instructions in Thumb Thunks. 143*bdd1243dSDimitry Andric // The ARM Attributes section contains information about the architecture chosen 144*bdd1243dSDimitry Andric // at compile time. We follow the convention that if at least one input object 145*bdd1243dSDimitry Andric // is compiled with an architecture that supports these features then lld is 146*bdd1243dSDimitry Andric // permitted to use them. 147*bdd1243dSDimitry Andric static void updateSupportedARMFeatures(const ARMAttributeParser &attributes) { 148*bdd1243dSDimitry Andric std::optional<unsigned> attr = 149*bdd1243dSDimitry Andric attributes.getAttributeValue(ARMBuildAttrs::CPU_arch); 150*bdd1243dSDimitry Andric if (!attr) 151*bdd1243dSDimitry Andric return; 152*bdd1243dSDimitry Andric auto arch = *attr; 153*bdd1243dSDimitry Andric switch (arch) { 154*bdd1243dSDimitry Andric case ARMBuildAttrs::Pre_v4: 155*bdd1243dSDimitry Andric case ARMBuildAttrs::v4: 156*bdd1243dSDimitry Andric case ARMBuildAttrs::v4T: 157*bdd1243dSDimitry Andric // Architectures prior to v5 do not support BLX instruction 158*bdd1243dSDimitry Andric break; 159*bdd1243dSDimitry Andric case ARMBuildAttrs::v5T: 160*bdd1243dSDimitry Andric case ARMBuildAttrs::v5TE: 161*bdd1243dSDimitry Andric case ARMBuildAttrs::v5TEJ: 162*bdd1243dSDimitry Andric case ARMBuildAttrs::v6: 163*bdd1243dSDimitry Andric case ARMBuildAttrs::v6KZ: 164*bdd1243dSDimitry Andric case ARMBuildAttrs::v6K: 165*bdd1243dSDimitry Andric config->armHasBlx = true; 166*bdd1243dSDimitry Andric // Architectures used in pre-Cortex processors do not support 167*bdd1243dSDimitry Andric // The J1 = 1 J2 = 1 Thumb branch range extension, with the exception 168*bdd1243dSDimitry Andric // of Architecture v6T2 (arm1156t2-s and arm1156t2f-s) that do. 169*bdd1243dSDimitry Andric break; 170*bdd1243dSDimitry Andric default: 171*bdd1243dSDimitry Andric // All other Architectures have BLX and extended branch encoding 172*bdd1243dSDimitry Andric config->armHasBlx = true; 173*bdd1243dSDimitry Andric config->armJ1J2BranchEncoding = true; 174*bdd1243dSDimitry Andric if (arch != ARMBuildAttrs::v6_M && arch != ARMBuildAttrs::v6S_M) 175*bdd1243dSDimitry Andric // All Architectures used in Cortex processors with the exception 176*bdd1243dSDimitry Andric // of v6-M and v6S-M have the MOVT and MOVW instructions. 177*bdd1243dSDimitry Andric config->armHasMovtMovw = true; 178*bdd1243dSDimitry Andric break; 179*bdd1243dSDimitry Andric } 180*bdd1243dSDimitry Andric } 181*bdd1243dSDimitry Andric 1820b57cec5SDimitry Andric InputFile::InputFile(Kind k, MemoryBufferRef m) 1830b57cec5SDimitry Andric : mb(m), groupId(nextGroupId), fileKind(k) { 1840b57cec5SDimitry Andric // All files within the same --{start,end}-group get the same group ID. 1850b57cec5SDimitry Andric // Otherwise, a new file will get a new group ID. 1860b57cec5SDimitry Andric if (!isInGroup) 1870b57cec5SDimitry Andric ++nextGroupId; 1880b57cec5SDimitry Andric } 1890b57cec5SDimitry Andric 190*bdd1243dSDimitry Andric std::optional<MemoryBufferRef> elf::readFile(StringRef path) { 191e8d8bef9SDimitry Andric llvm::TimeTraceScope timeScope("Load input files", path); 192e8d8bef9SDimitry Andric 1930b57cec5SDimitry Andric // The --chroot option changes our virtual root directory. 1940b57cec5SDimitry Andric // This is useful when you are dealing with files created by --reproduce. 1950b57cec5SDimitry Andric if (!config->chroot.empty() && path.startswith("/")) 19604eeddc0SDimitry Andric path = saver().save(config->chroot + path); 1970b57cec5SDimitry Andric 1980b57cec5SDimitry Andric log(path); 199e8d8bef9SDimitry Andric config->dependencyFiles.insert(llvm::CachedHashString(path)); 2000b57cec5SDimitry Andric 201fe6060f1SDimitry Andric auto mbOrErr = MemoryBuffer::getFile(path, /*IsText=*/false, 202fe6060f1SDimitry Andric /*RequiresNullTerminator=*/false); 2030b57cec5SDimitry Andric if (auto ec = mbOrErr.getError()) { 2040b57cec5SDimitry Andric error("cannot open " + path + ": " + ec.message()); 205*bdd1243dSDimitry Andric return std::nullopt; 2060b57cec5SDimitry Andric } 2070b57cec5SDimitry Andric 20804eeddc0SDimitry Andric MemoryBufferRef mbref = (*mbOrErr)->getMemBufferRef(); 209*bdd1243dSDimitry Andric ctx.memoryBuffers.push_back(std::move(*mbOrErr)); // take MB ownership 2100b57cec5SDimitry Andric 2110b57cec5SDimitry Andric if (tar) 2120b57cec5SDimitry Andric tar->append(relativeToRoot(path), mbref.getBuffer()); 2130b57cec5SDimitry Andric return mbref; 2140b57cec5SDimitry Andric } 2150b57cec5SDimitry Andric 2160b57cec5SDimitry Andric // All input object files must be for the same architecture 2170b57cec5SDimitry Andric // (e.g. it does not make sense to link x86 object files with 2180b57cec5SDimitry Andric // MIPS object files.) This function checks for that error. 2190b57cec5SDimitry Andric static bool isCompatible(InputFile *file) { 2200b57cec5SDimitry Andric if (!file->isElf() && !isa<BitcodeFile>(file)) 2210b57cec5SDimitry Andric return true; 2220b57cec5SDimitry Andric 2230b57cec5SDimitry Andric if (file->ekind == config->ekind && file->emachine == config->emachine) { 2240b57cec5SDimitry Andric if (config->emachine != EM_MIPS) 2250b57cec5SDimitry Andric return true; 2260b57cec5SDimitry Andric if (isMipsN32Abi(file) == config->mipsN32Abi) 2270b57cec5SDimitry Andric return true; 2280b57cec5SDimitry Andric } 2290b57cec5SDimitry Andric 2305ffd83dbSDimitry Andric StringRef target = 2315ffd83dbSDimitry Andric !config->bfdname.empty() ? config->bfdname : config->emulation; 2325ffd83dbSDimitry Andric if (!target.empty()) { 2335ffd83dbSDimitry Andric error(toString(file) + " is incompatible with " + target); 23485868e8aSDimitry Andric return false; 23585868e8aSDimitry Andric } 23685868e8aSDimitry Andric 237d56accc7SDimitry Andric InputFile *existing = nullptr; 238*bdd1243dSDimitry Andric if (!ctx.objectFiles.empty()) 239*bdd1243dSDimitry Andric existing = ctx.objectFiles[0]; 240*bdd1243dSDimitry Andric else if (!ctx.sharedFiles.empty()) 241*bdd1243dSDimitry Andric existing = ctx.sharedFiles[0]; 242*bdd1243dSDimitry Andric else if (!ctx.bitcodeFiles.empty()) 243*bdd1243dSDimitry Andric existing = ctx.bitcodeFiles[0]; 244d56accc7SDimitry Andric std::string with; 245d56accc7SDimitry Andric if (existing) 246d56accc7SDimitry Andric with = " with " + toString(existing); 247d56accc7SDimitry Andric error(toString(file) + " is incompatible" + with); 2480b57cec5SDimitry Andric return false; 2490b57cec5SDimitry Andric } 2500b57cec5SDimitry Andric 2510b57cec5SDimitry Andric template <class ELFT> static void doParseFile(InputFile *file) { 2520b57cec5SDimitry Andric if (!isCompatible(file)) 2530b57cec5SDimitry Andric return; 2540b57cec5SDimitry Andric 2550b57cec5SDimitry Andric // Binary file 2560b57cec5SDimitry Andric if (auto *f = dyn_cast<BinaryFile>(file)) { 257*bdd1243dSDimitry Andric ctx.binaryFiles.push_back(f); 2580b57cec5SDimitry Andric f->parse(); 2590b57cec5SDimitry Andric return; 2600b57cec5SDimitry Andric } 2610b57cec5SDimitry Andric 2620b57cec5SDimitry Andric // Lazy object file 2630eae32dcSDimitry Andric if (file->lazy) { 2640eae32dcSDimitry Andric if (auto *f = dyn_cast<BitcodeFile>(file)) { 265*bdd1243dSDimitry Andric ctx.lazyBitcodeFiles.push_back(f); 2660eae32dcSDimitry Andric f->parseLazy(); 2670eae32dcSDimitry Andric } else { 2680eae32dcSDimitry Andric cast<ObjFile<ELFT>>(file)->parseLazy(); 2690eae32dcSDimitry Andric } 2700b57cec5SDimitry Andric return; 2710b57cec5SDimitry Andric } 2720b57cec5SDimitry Andric 2730b57cec5SDimitry Andric if (config->trace) 2740b57cec5SDimitry Andric message(toString(file)); 2750b57cec5SDimitry Andric 2760b57cec5SDimitry Andric // .so file 2770b57cec5SDimitry Andric if (auto *f = dyn_cast<SharedFile>(file)) { 2780b57cec5SDimitry Andric f->parse<ELFT>(); 2790b57cec5SDimitry Andric return; 2800b57cec5SDimitry Andric } 2810b57cec5SDimitry Andric 2820b57cec5SDimitry Andric // LLVM bitcode file 2830b57cec5SDimitry Andric if (auto *f = dyn_cast<BitcodeFile>(file)) { 284*bdd1243dSDimitry Andric ctx.bitcodeFiles.push_back(f); 285*bdd1243dSDimitry Andric f->parse(); 2860b57cec5SDimitry Andric return; 2870b57cec5SDimitry Andric } 2880b57cec5SDimitry Andric 2890b57cec5SDimitry Andric // Regular object file 290*bdd1243dSDimitry Andric ctx.objectFiles.push_back(cast<ELFFileBase>(file)); 2910b57cec5SDimitry Andric cast<ObjFile<ELFT>>(file)->parse(); 2920b57cec5SDimitry Andric } 2930b57cec5SDimitry Andric 2940b57cec5SDimitry Andric // Add symbols in File to the symbol table. 2951fd87a68SDimitry Andric void elf::parseFile(InputFile *file) { invokeELFT(doParseFile, file); } 2960b57cec5SDimitry Andric 2970b57cec5SDimitry Andric // Concatenates arguments to construct a string representing an error location. 2980b57cec5SDimitry Andric static std::string createFileLineMsg(StringRef path, unsigned line) { 2995ffd83dbSDimitry Andric std::string filename = std::string(path::filename(path)); 3000b57cec5SDimitry Andric std::string lineno = ":" + std::to_string(line); 3010b57cec5SDimitry Andric if (filename == path) 3020b57cec5SDimitry Andric return filename + lineno; 3030b57cec5SDimitry Andric return filename + lineno + " (" + path.str() + lineno + ")"; 3040b57cec5SDimitry Andric } 3050b57cec5SDimitry Andric 3060b57cec5SDimitry Andric template <class ELFT> 3070b57cec5SDimitry Andric static std::string getSrcMsgAux(ObjFile<ELFT> &file, const Symbol &sym, 3080b57cec5SDimitry Andric InputSectionBase &sec, uint64_t offset) { 3090b57cec5SDimitry Andric // In DWARF, functions and variables are stored to different places. 3100b57cec5SDimitry Andric // First, look up a function for a given offset. 311*bdd1243dSDimitry Andric if (std::optional<DILineInfo> info = file.getDILineInfo(&sec, offset)) 3120b57cec5SDimitry Andric return createFileLineMsg(info->FileName, info->Line); 3130b57cec5SDimitry Andric 3140b57cec5SDimitry Andric // If it failed, look up again as a variable. 315*bdd1243dSDimitry Andric if (std::optional<std::pair<std::string, unsigned>> fileLine = 3160b57cec5SDimitry Andric file.getVariableLoc(sym.getName())) 3170b57cec5SDimitry Andric return createFileLineMsg(fileLine->first, fileLine->second); 3180b57cec5SDimitry Andric 3190b57cec5SDimitry Andric // File.sourceFile contains STT_FILE symbol, and that is a last resort. 3205ffd83dbSDimitry Andric return std::string(file.sourceFile); 3210b57cec5SDimitry Andric } 3220b57cec5SDimitry Andric 3230b57cec5SDimitry Andric std::string InputFile::getSrcMsg(const Symbol &sym, InputSectionBase &sec, 3240b57cec5SDimitry Andric uint64_t offset) { 3250b57cec5SDimitry Andric if (kind() != ObjKind) 3260b57cec5SDimitry Andric return ""; 327*bdd1243dSDimitry Andric switch (ekind) { 3280b57cec5SDimitry Andric default: 3290b57cec5SDimitry Andric llvm_unreachable("Invalid kind"); 3300b57cec5SDimitry Andric case ELF32LEKind: 3310b57cec5SDimitry Andric return getSrcMsgAux(cast<ObjFile<ELF32LE>>(*this), sym, sec, offset); 3320b57cec5SDimitry Andric case ELF32BEKind: 3330b57cec5SDimitry Andric return getSrcMsgAux(cast<ObjFile<ELF32BE>>(*this), sym, sec, offset); 3340b57cec5SDimitry Andric case ELF64LEKind: 3350b57cec5SDimitry Andric return getSrcMsgAux(cast<ObjFile<ELF64LE>>(*this), sym, sec, offset); 3360b57cec5SDimitry Andric case ELF64BEKind: 3370b57cec5SDimitry Andric return getSrcMsgAux(cast<ObjFile<ELF64BE>>(*this), sym, sec, offset); 3380b57cec5SDimitry Andric } 3390b57cec5SDimitry Andric } 3400b57cec5SDimitry Andric 341e8d8bef9SDimitry Andric StringRef InputFile::getNameForScript() const { 342e8d8bef9SDimitry Andric if (archiveName.empty()) 343e8d8bef9SDimitry Andric return getName(); 344e8d8bef9SDimitry Andric 345e8d8bef9SDimitry Andric if (nameForScriptCache.empty()) 346e8d8bef9SDimitry Andric nameForScriptCache = (archiveName + Twine(':') + getName()).str(); 347e8d8bef9SDimitry Andric 348e8d8bef9SDimitry Andric return nameForScriptCache; 349e8d8bef9SDimitry Andric } 350e8d8bef9SDimitry Andric 351*bdd1243dSDimitry Andric // An ELF object file may contain a `.deplibs` section. If it exists, the 352*bdd1243dSDimitry Andric // section contains a list of library specifiers such as `m` for libm. This 353*bdd1243dSDimitry Andric // function resolves a given name by finding the first matching library checking 354*bdd1243dSDimitry Andric // the various ways that a library can be specified to LLD. This ELF extension 355*bdd1243dSDimitry Andric // is a form of autolinking and is called `dependent libraries`. It is currently 356*bdd1243dSDimitry Andric // unique to LLVM and lld. 357*bdd1243dSDimitry Andric static void addDependentLibrary(StringRef specifier, const InputFile *f) { 358*bdd1243dSDimitry Andric if (!config->dependentLibraries) 359*bdd1243dSDimitry Andric return; 360*bdd1243dSDimitry Andric if (std::optional<std::string> s = searchLibraryBaseName(specifier)) 361*bdd1243dSDimitry Andric ctx.driver.addFile(saver().save(*s), /*withLOption=*/true); 362*bdd1243dSDimitry Andric else if (std::optional<std::string> s = findFromSearchPaths(specifier)) 363*bdd1243dSDimitry Andric ctx.driver.addFile(saver().save(*s), /*withLOption=*/true); 364*bdd1243dSDimitry Andric else if (fs::exists(specifier)) 365*bdd1243dSDimitry Andric ctx.driver.addFile(specifier, /*withLOption=*/false); 366*bdd1243dSDimitry Andric else 367*bdd1243dSDimitry Andric error(toString(f) + 368*bdd1243dSDimitry Andric ": unable to find library from dependent library specifier: " + 369*bdd1243dSDimitry Andric specifier); 370*bdd1243dSDimitry Andric } 371*bdd1243dSDimitry Andric 372*bdd1243dSDimitry Andric // Record the membership of a section group so that in the garbage collection 373*bdd1243dSDimitry Andric // pass, section group members are kept or discarded as a unit. 374*bdd1243dSDimitry Andric template <class ELFT> 375*bdd1243dSDimitry Andric static void handleSectionGroup(ArrayRef<InputSectionBase *> sections, 376*bdd1243dSDimitry Andric ArrayRef<typename ELFT::Word> entries) { 377*bdd1243dSDimitry Andric bool hasAlloc = false; 378*bdd1243dSDimitry Andric for (uint32_t index : entries.slice(1)) { 379*bdd1243dSDimitry Andric if (index >= sections.size()) 380*bdd1243dSDimitry Andric return; 381*bdd1243dSDimitry Andric if (InputSectionBase *s = sections[index]) 382*bdd1243dSDimitry Andric if (s != &InputSection::discarded && s->flags & SHF_ALLOC) 383*bdd1243dSDimitry Andric hasAlloc = true; 384*bdd1243dSDimitry Andric } 385*bdd1243dSDimitry Andric 386*bdd1243dSDimitry Andric // If any member has the SHF_ALLOC flag, the whole group is subject to garbage 387*bdd1243dSDimitry Andric // collection. See the comment in markLive(). This rule retains .debug_types 388*bdd1243dSDimitry Andric // and .rela.debug_types. 389*bdd1243dSDimitry Andric if (!hasAlloc) 390*bdd1243dSDimitry Andric return; 391*bdd1243dSDimitry Andric 392*bdd1243dSDimitry Andric // Connect the members in a circular doubly-linked list via 393*bdd1243dSDimitry Andric // nextInSectionGroup. 394*bdd1243dSDimitry Andric InputSectionBase *head; 395*bdd1243dSDimitry Andric InputSectionBase *prev = nullptr; 396*bdd1243dSDimitry Andric for (uint32_t index : entries.slice(1)) { 397*bdd1243dSDimitry Andric InputSectionBase *s = sections[index]; 398*bdd1243dSDimitry Andric if (!s || s == &InputSection::discarded) 399*bdd1243dSDimitry Andric continue; 400*bdd1243dSDimitry Andric if (prev) 401*bdd1243dSDimitry Andric prev->nextInSectionGroup = s; 402*bdd1243dSDimitry Andric else 403*bdd1243dSDimitry Andric head = s; 404*bdd1243dSDimitry Andric prev = s; 405*bdd1243dSDimitry Andric } 406*bdd1243dSDimitry Andric if (prev) 407*bdd1243dSDimitry Andric prev->nextInSectionGroup = head; 408*bdd1243dSDimitry Andric } 409*bdd1243dSDimitry Andric 4105ffd83dbSDimitry Andric template <class ELFT> DWARFCache *ObjFile<ELFT>::getDwarf() { 4115ffd83dbSDimitry Andric llvm::call_once(initDwarf, [this]() { 4125ffd83dbSDimitry Andric dwarf = std::make_unique<DWARFCache>(std::make_unique<DWARFContext>( 4135ffd83dbSDimitry Andric std::make_unique<LLDDwarfObj<ELFT>>(this), "", 4145ffd83dbSDimitry Andric [&](Error err) { warn(getName() + ": " + toString(std::move(err))); }, 4155ffd83dbSDimitry Andric [&](Error warning) { 4165ffd83dbSDimitry Andric warn(getName() + ": " + toString(std::move(warning))); 4175ffd83dbSDimitry Andric })); 4185ffd83dbSDimitry Andric }); 4195ffd83dbSDimitry Andric 4205ffd83dbSDimitry Andric return dwarf.get(); 4210b57cec5SDimitry Andric } 4220b57cec5SDimitry Andric 4230b57cec5SDimitry Andric // Returns the pair of file name and line number describing location of data 4240b57cec5SDimitry Andric // object (variable, array, etc) definition. 4250b57cec5SDimitry Andric template <class ELFT> 426*bdd1243dSDimitry Andric std::optional<std::pair<std::string, unsigned>> 4270b57cec5SDimitry Andric ObjFile<ELFT>::getVariableLoc(StringRef name) { 4285ffd83dbSDimitry Andric return getDwarf()->getVariableLoc(name); 4290b57cec5SDimitry Andric } 4300b57cec5SDimitry Andric 4310b57cec5SDimitry Andric // Returns source line information for a given offset 4320b57cec5SDimitry Andric // using DWARF debug info. 4330b57cec5SDimitry Andric template <class ELFT> 434*bdd1243dSDimitry Andric std::optional<DILineInfo> ObjFile<ELFT>::getDILineInfo(InputSectionBase *s, 4350b57cec5SDimitry Andric uint64_t offset) { 4360b57cec5SDimitry Andric // Detect SectionIndex for specified section. 4370b57cec5SDimitry Andric uint64_t sectionIndex = object::SectionedAddress::UndefSection; 4380b57cec5SDimitry Andric ArrayRef<InputSectionBase *> sections = s->file->getSections(); 4390b57cec5SDimitry Andric for (uint64_t curIndex = 0; curIndex < sections.size(); ++curIndex) { 4400b57cec5SDimitry Andric if (s == sections[curIndex]) { 4410b57cec5SDimitry Andric sectionIndex = curIndex; 4420b57cec5SDimitry Andric break; 4430b57cec5SDimitry Andric } 4440b57cec5SDimitry Andric } 4450b57cec5SDimitry Andric 4465ffd83dbSDimitry Andric return getDwarf()->getDILineInfo(offset, sectionIndex); 4470b57cec5SDimitry Andric } 4480b57cec5SDimitry Andric 449*bdd1243dSDimitry Andric ELFFileBase::ELFFileBase(Kind k, ELFKind ekind, MemoryBufferRef mb) 450*bdd1243dSDimitry Andric : InputFile(k, mb) { 451*bdd1243dSDimitry Andric this->ekind = ekind; 4520b57cec5SDimitry Andric } 4530b57cec5SDimitry Andric 4540b57cec5SDimitry Andric template <typename Elf_Shdr> 4550b57cec5SDimitry Andric static const Elf_Shdr *findSection(ArrayRef<Elf_Shdr> sections, uint32_t type) { 4560b57cec5SDimitry Andric for (const Elf_Shdr &sec : sections) 4570b57cec5SDimitry Andric if (sec.sh_type == type) 4580b57cec5SDimitry Andric return &sec; 4590b57cec5SDimitry Andric return nullptr; 4600b57cec5SDimitry Andric } 4610b57cec5SDimitry Andric 462*bdd1243dSDimitry Andric void ELFFileBase::init() { 463*bdd1243dSDimitry Andric switch (ekind) { 464*bdd1243dSDimitry Andric case ELF32LEKind: 465*bdd1243dSDimitry Andric init<ELF32LE>(fileKind); 466*bdd1243dSDimitry Andric break; 467*bdd1243dSDimitry Andric case ELF32BEKind: 468*bdd1243dSDimitry Andric init<ELF32BE>(fileKind); 469*bdd1243dSDimitry Andric break; 470*bdd1243dSDimitry Andric case ELF64LEKind: 471*bdd1243dSDimitry Andric init<ELF64LE>(fileKind); 472*bdd1243dSDimitry Andric break; 473*bdd1243dSDimitry Andric case ELF64BEKind: 474*bdd1243dSDimitry Andric init<ELF64BE>(fileKind); 475*bdd1243dSDimitry Andric break; 476*bdd1243dSDimitry Andric default: 477*bdd1243dSDimitry Andric llvm_unreachable("getELFKind"); 478*bdd1243dSDimitry Andric } 479*bdd1243dSDimitry Andric } 480*bdd1243dSDimitry Andric 481*bdd1243dSDimitry Andric template <class ELFT> void ELFFileBase::init(InputFile::Kind k) { 4820b57cec5SDimitry Andric using Elf_Shdr = typename ELFT::Shdr; 4830b57cec5SDimitry Andric using Elf_Sym = typename ELFT::Sym; 4840b57cec5SDimitry Andric 4850b57cec5SDimitry Andric // Initialize trivial attributes. 4860b57cec5SDimitry Andric const ELFFile<ELFT> &obj = getObj<ELFT>(); 487e8d8bef9SDimitry Andric emachine = obj.getHeader().e_machine; 488e8d8bef9SDimitry Andric osabi = obj.getHeader().e_ident[llvm::ELF::EI_OSABI]; 489e8d8bef9SDimitry Andric abiVersion = obj.getHeader().e_ident[llvm::ELF::EI_ABIVERSION]; 4900b57cec5SDimitry Andric 4910b57cec5SDimitry Andric ArrayRef<Elf_Shdr> sections = CHECK(obj.sections(), this); 4920eae32dcSDimitry Andric elfShdrs = sections.data(); 4930eae32dcSDimitry Andric numELFShdrs = sections.size(); 4940b57cec5SDimitry Andric 4950b57cec5SDimitry Andric // Find a symbol table. 4960b57cec5SDimitry Andric const Elf_Shdr *symtabSec = 497*bdd1243dSDimitry Andric findSection(sections, k == SharedKind ? SHT_DYNSYM : SHT_SYMTAB); 4980b57cec5SDimitry Andric 4990b57cec5SDimitry Andric if (!symtabSec) 5000b57cec5SDimitry Andric return; 5010b57cec5SDimitry Andric 5020b57cec5SDimitry Andric // Initialize members corresponding to a symbol table. 5030b57cec5SDimitry Andric firstGlobal = symtabSec->sh_info; 5040b57cec5SDimitry Andric 5050b57cec5SDimitry Andric ArrayRef<Elf_Sym> eSyms = CHECK(obj.symbols(symtabSec), this); 5060b57cec5SDimitry Andric if (firstGlobal == 0 || firstGlobal > eSyms.size()) 5070b57cec5SDimitry Andric fatal(toString(this) + ": invalid sh_info in symbol table"); 5080b57cec5SDimitry Andric 5090b57cec5SDimitry Andric elfSyms = reinterpret_cast<const void *>(eSyms.data()); 5100eae32dcSDimitry Andric numELFSyms = uint32_t(eSyms.size()); 5110b57cec5SDimitry Andric stringTable = CHECK(obj.getStringTableForSymtab(*symtabSec, sections), this); 5120b57cec5SDimitry Andric } 5130b57cec5SDimitry Andric 5140b57cec5SDimitry Andric template <class ELFT> 5150b57cec5SDimitry Andric uint32_t ObjFile<ELFT>::getSectionIndex(const Elf_Sym &sym) const { 5160b57cec5SDimitry Andric return CHECK( 517e8d8bef9SDimitry Andric this->getObj().getSectionIndex(sym, getELFSyms<ELFT>(), shndxTable), 5180b57cec5SDimitry Andric this); 5190b57cec5SDimitry Andric } 5200b57cec5SDimitry Andric 5210b57cec5SDimitry Andric template <class ELFT> void ObjFile<ELFT>::parse(bool ignoreComdats) { 5221fd87a68SDimitry Andric object::ELFFile<ELFT> obj = this->getObj(); 5230b57cec5SDimitry Andric // Read a section table. justSymbols is usually false. 524*bdd1243dSDimitry Andric if (this->justSymbols) { 5250b57cec5SDimitry Andric initializeJustSymbols(); 526*bdd1243dSDimitry Andric initializeSymbols(obj); 527*bdd1243dSDimitry Andric return; 528*bdd1243dSDimitry Andric } 529*bdd1243dSDimitry Andric 530*bdd1243dSDimitry Andric // Handle dependent libraries and selection of section groups as these are not 531*bdd1243dSDimitry Andric // done in parallel. 532*bdd1243dSDimitry Andric ArrayRef<Elf_Shdr> objSections = getELFShdrs<ELFT>(); 533*bdd1243dSDimitry Andric StringRef shstrtab = CHECK(obj.getSectionStringTable(objSections), this); 534*bdd1243dSDimitry Andric uint64_t size = objSections.size(); 535*bdd1243dSDimitry Andric sections.resize(size); 536*bdd1243dSDimitry Andric for (size_t i = 0; i != size; ++i) { 537*bdd1243dSDimitry Andric const Elf_Shdr &sec = objSections[i]; 538*bdd1243dSDimitry Andric if (sec.sh_type == SHT_LLVM_DEPENDENT_LIBRARIES && !config->relocatable) { 539*bdd1243dSDimitry Andric StringRef name = check(obj.getSectionName(sec, shstrtab)); 540*bdd1243dSDimitry Andric ArrayRef<char> data = CHECK( 541*bdd1243dSDimitry Andric this->getObj().template getSectionContentsAsArray<char>(sec), this); 542*bdd1243dSDimitry Andric if (!data.empty() && data.back() != '\0') { 543*bdd1243dSDimitry Andric error( 544*bdd1243dSDimitry Andric toString(this) + 545*bdd1243dSDimitry Andric ": corrupted dependent libraries section (unterminated string): " + 546*bdd1243dSDimitry Andric name); 547*bdd1243dSDimitry Andric } else { 548*bdd1243dSDimitry Andric for (const char *d = data.begin(), *e = data.end(); d < e;) { 549*bdd1243dSDimitry Andric StringRef s(d); 550*bdd1243dSDimitry Andric addDependentLibrary(s, this); 551*bdd1243dSDimitry Andric d += s.size() + 1; 552*bdd1243dSDimitry Andric } 553*bdd1243dSDimitry Andric } 554*bdd1243dSDimitry Andric this->sections[i] = &InputSection::discarded; 555*bdd1243dSDimitry Andric continue; 556*bdd1243dSDimitry Andric } 557*bdd1243dSDimitry Andric 558*bdd1243dSDimitry Andric if (sec.sh_type == SHT_ARM_ATTRIBUTES && config->emachine == EM_ARM) { 559*bdd1243dSDimitry Andric ARMAttributeParser attributes; 560*bdd1243dSDimitry Andric ArrayRef<uint8_t> contents = 561*bdd1243dSDimitry Andric check(this->getObj().getSectionContents(sec)); 562*bdd1243dSDimitry Andric StringRef name = check(obj.getSectionName(sec, shstrtab)); 563*bdd1243dSDimitry Andric this->sections[i] = &InputSection::discarded; 564*bdd1243dSDimitry Andric if (Error e = 565*bdd1243dSDimitry Andric attributes.parse(contents, ekind == ELF32LEKind ? support::little 566*bdd1243dSDimitry Andric : support::big)) { 567*bdd1243dSDimitry Andric InputSection isec(*this, sec, name); 568*bdd1243dSDimitry Andric warn(toString(&isec) + ": " + llvm::toString(std::move(e))); 569*bdd1243dSDimitry Andric } else { 570*bdd1243dSDimitry Andric updateSupportedARMFeatures(attributes); 571*bdd1243dSDimitry Andric updateARMVFPArgs(attributes, this); 572*bdd1243dSDimitry Andric 573*bdd1243dSDimitry Andric // FIXME: Retain the first attribute section we see. The eglibc ARM 574*bdd1243dSDimitry Andric // dynamic loaders require the presence of an attribute section for 575*bdd1243dSDimitry Andric // dlopen to work. In a full implementation we would merge all attribute 576*bdd1243dSDimitry Andric // sections. 577*bdd1243dSDimitry Andric if (in.attributes == nullptr) { 578*bdd1243dSDimitry Andric in.attributes = std::make_unique<InputSection>(*this, sec, name); 579*bdd1243dSDimitry Andric this->sections[i] = in.attributes.get(); 580*bdd1243dSDimitry Andric } 581*bdd1243dSDimitry Andric } 582*bdd1243dSDimitry Andric } 583*bdd1243dSDimitry Andric 584*bdd1243dSDimitry Andric if (sec.sh_type != SHT_GROUP) 585*bdd1243dSDimitry Andric continue; 586*bdd1243dSDimitry Andric StringRef signature = getShtGroupSignature(objSections, sec); 587*bdd1243dSDimitry Andric ArrayRef<Elf_Word> entries = 588*bdd1243dSDimitry Andric CHECK(obj.template getSectionContentsAsArray<Elf_Word>(sec), this); 589*bdd1243dSDimitry Andric if (entries.empty()) 590*bdd1243dSDimitry Andric fatal(toString(this) + ": empty SHT_GROUP"); 591*bdd1243dSDimitry Andric 592*bdd1243dSDimitry Andric Elf_Word flag = entries[0]; 593*bdd1243dSDimitry Andric if (flag && flag != GRP_COMDAT) 594*bdd1243dSDimitry Andric fatal(toString(this) + ": unsupported SHT_GROUP format"); 595*bdd1243dSDimitry Andric 596*bdd1243dSDimitry Andric bool keepGroup = 597*bdd1243dSDimitry Andric (flag & GRP_COMDAT) == 0 || ignoreComdats || 598*bdd1243dSDimitry Andric symtab.comdatGroups.try_emplace(CachedHashStringRef(signature), this) 599*bdd1243dSDimitry Andric .second; 600*bdd1243dSDimitry Andric if (keepGroup) { 601*bdd1243dSDimitry Andric if (config->relocatable) 602*bdd1243dSDimitry Andric this->sections[i] = createInputSection( 603*bdd1243dSDimitry Andric i, sec, check(obj.getSectionName(sec, shstrtab))); 604*bdd1243dSDimitry Andric continue; 605*bdd1243dSDimitry Andric } 606*bdd1243dSDimitry Andric 607*bdd1243dSDimitry Andric // Otherwise, discard group members. 608*bdd1243dSDimitry Andric for (uint32_t secIndex : entries.slice(1)) { 609*bdd1243dSDimitry Andric if (secIndex >= size) 610*bdd1243dSDimitry Andric fatal(toString(this) + 611*bdd1243dSDimitry Andric ": invalid section index in group: " + Twine(secIndex)); 612*bdd1243dSDimitry Andric this->sections[secIndex] = &InputSection::discarded; 613*bdd1243dSDimitry Andric } 614*bdd1243dSDimitry Andric } 6150b57cec5SDimitry Andric 6160b57cec5SDimitry Andric // Read a symbol table. 6171fd87a68SDimitry Andric initializeSymbols(obj); 6180b57cec5SDimitry Andric } 6190b57cec5SDimitry Andric 6200b57cec5SDimitry Andric // Sections with SHT_GROUP and comdat bits define comdat section groups. 6210b57cec5SDimitry Andric // They are identified and deduplicated by group name. This function 6220b57cec5SDimitry Andric // returns a group name. 6230b57cec5SDimitry Andric template <class ELFT> 6240b57cec5SDimitry Andric StringRef ObjFile<ELFT>::getShtGroupSignature(ArrayRef<Elf_Shdr> sections, 6250b57cec5SDimitry Andric const Elf_Shdr &sec) { 6260b57cec5SDimitry Andric typename ELFT::SymRange symbols = this->getELFSyms<ELFT>(); 6270b57cec5SDimitry Andric if (sec.sh_info >= symbols.size()) 6280b57cec5SDimitry Andric fatal(toString(this) + ": invalid symbol index"); 6290b57cec5SDimitry Andric const typename ELFT::Sym &sym = symbols[sec.sh_info]; 630349cc55cSDimitry Andric return CHECK(sym.getName(this->stringTable), this); 6310b57cec5SDimitry Andric } 6320b57cec5SDimitry Andric 63385868e8aSDimitry Andric template <class ELFT> 63485868e8aSDimitry Andric bool ObjFile<ELFT>::shouldMerge(const Elf_Shdr &sec, StringRef name) { 6350b57cec5SDimitry Andric // On a regular link we don't merge sections if -O0 (default is -O1). This 6360b57cec5SDimitry Andric // sometimes makes the linker significantly faster, although the output will 6370b57cec5SDimitry Andric // be bigger. 6380b57cec5SDimitry Andric // 6390b57cec5SDimitry Andric // Doing the same for -r would create a problem as it would combine sections 6400b57cec5SDimitry Andric // with different sh_entsize. One option would be to just copy every SHF_MERGE 6410b57cec5SDimitry Andric // section as is to the output. While this would produce a valid ELF file with 6420b57cec5SDimitry Andric // usable SHF_MERGE sections, tools like (llvm-)?dwarfdump get confused when 6430b57cec5SDimitry Andric // they see two .debug_str. We could have separate logic for combining 6440b57cec5SDimitry Andric // SHF_MERGE sections based both on their name and sh_entsize, but that seems 6450b57cec5SDimitry Andric // to be more trouble than it is worth. Instead, we just use the regular (-O1) 6460b57cec5SDimitry Andric // logic for -r. 6470b57cec5SDimitry Andric if (config->optimize == 0 && !config->relocatable) 6480b57cec5SDimitry Andric return false; 6490b57cec5SDimitry Andric 6500b57cec5SDimitry Andric // A mergeable section with size 0 is useless because they don't have 6510b57cec5SDimitry Andric // any data to merge. A mergeable string section with size 0 can be 6520b57cec5SDimitry Andric // argued as invalid because it doesn't end with a null character. 6530b57cec5SDimitry Andric // We'll avoid a mess by handling them as if they were non-mergeable. 6540b57cec5SDimitry Andric if (sec.sh_size == 0) 6550b57cec5SDimitry Andric return false; 6560b57cec5SDimitry Andric 6570b57cec5SDimitry Andric // Check for sh_entsize. The ELF spec is not clear about the zero 6580b57cec5SDimitry Andric // sh_entsize. It says that "the member [sh_entsize] contains 0 if 6590b57cec5SDimitry Andric // the section does not hold a table of fixed-size entries". We know 6600b57cec5SDimitry Andric // that Rust 1.13 produces a string mergeable section with a zero 6610b57cec5SDimitry Andric // sh_entsize. Here we just accept it rather than being picky about it. 6620b57cec5SDimitry Andric uint64_t entSize = sec.sh_entsize; 6630b57cec5SDimitry Andric if (entSize == 0) 6640b57cec5SDimitry Andric return false; 6650b57cec5SDimitry Andric if (sec.sh_size % entSize) 66685868e8aSDimitry Andric fatal(toString(this) + ":(" + name + "): SHF_MERGE section size (" + 66785868e8aSDimitry Andric Twine(sec.sh_size) + ") must be a multiple of sh_entsize (" + 66885868e8aSDimitry Andric Twine(entSize) + ")"); 6690b57cec5SDimitry Andric 6705ffd83dbSDimitry Andric if (sec.sh_flags & SHF_WRITE) 67185868e8aSDimitry Andric fatal(toString(this) + ":(" + name + 67285868e8aSDimitry Andric "): writable SHF_MERGE section is not supported"); 6730b57cec5SDimitry Andric 6740b57cec5SDimitry Andric return true; 6750b57cec5SDimitry Andric } 6760b57cec5SDimitry Andric 6770b57cec5SDimitry Andric // This is for --just-symbols. 6780b57cec5SDimitry Andric // 6790b57cec5SDimitry Andric // --just-symbols is a very minor feature that allows you to link your 6800b57cec5SDimitry Andric // output against other existing program, so that if you load both your 6810b57cec5SDimitry Andric // program and the other program into memory, your output can refer the 6820b57cec5SDimitry Andric // other program's symbols. 6830b57cec5SDimitry Andric // 6840b57cec5SDimitry Andric // When the option is given, we link "just symbols". The section table is 6850b57cec5SDimitry Andric // initialized with null pointers. 6860b57cec5SDimitry Andric template <class ELFT> void ObjFile<ELFT>::initializeJustSymbols() { 6870eae32dcSDimitry Andric sections.resize(numELFShdrs); 6880b57cec5SDimitry Andric } 6890b57cec5SDimitry Andric 6900b57cec5SDimitry Andric template <class ELFT> 6911fd87a68SDimitry Andric void ObjFile<ELFT>::initializeSections(bool ignoreComdats, 6921fd87a68SDimitry Andric const llvm::object::ELFFile<ELFT> &obj) { 6930eae32dcSDimitry Andric ArrayRef<Elf_Shdr> objSections = getELFShdrs<ELFT>(); 694349cc55cSDimitry Andric StringRef shstrtab = CHECK(obj.getSectionStringTable(objSections), this); 6950b57cec5SDimitry Andric uint64_t size = objSections.size(); 696*bdd1243dSDimitry Andric SmallVector<ArrayRef<Elf_Word>, 0> selectedGroups; 69704eeddc0SDimitry Andric for (size_t i = 0; i != size; ++i) { 6980b57cec5SDimitry Andric if (this->sections[i] == &InputSection::discarded) 6990b57cec5SDimitry Andric continue; 7000b57cec5SDimitry Andric const Elf_Shdr &sec = objSections[i]; 7010b57cec5SDimitry Andric 7020b57cec5SDimitry Andric // SHF_EXCLUDE'ed sections are discarded by the linker. However, 7030b57cec5SDimitry Andric // if -r is given, we'll let the final link discard such sections. 7040b57cec5SDimitry Andric // This is compatible with GNU. 7050b57cec5SDimitry Andric if ((sec.sh_flags & SHF_EXCLUDE) && !config->relocatable) { 7060eae32dcSDimitry Andric if (sec.sh_type == SHT_LLVM_CALL_GRAPH_PROFILE) 7070eae32dcSDimitry Andric cgProfileSectionIndex = i; 7080b57cec5SDimitry Andric if (sec.sh_type == SHT_LLVM_ADDRSIG) { 7090b57cec5SDimitry Andric // We ignore the address-significance table if we know that the object 7100b57cec5SDimitry Andric // file was created by objcopy or ld -r. This is because these tools 7110b57cec5SDimitry Andric // will reorder the symbols in the symbol table, invalidating the data 7120b57cec5SDimitry Andric // in the address-significance table, which refers to symbols by index. 7130b57cec5SDimitry Andric if (sec.sh_link != 0) 7140b57cec5SDimitry Andric this->addrsigSec = &sec; 7150b57cec5SDimitry Andric else if (config->icf == ICFLevel::Safe) 716fe6060f1SDimitry Andric warn(toString(this) + 717fe6060f1SDimitry Andric ": --icf=safe conservatively ignores " 718fe6060f1SDimitry Andric "SHT_LLVM_ADDRSIG [index " + 719fe6060f1SDimitry Andric Twine(i) + 720fe6060f1SDimitry Andric "] with sh_link=0 " 721fe6060f1SDimitry Andric "(likely created using objcopy or ld -r)"); 7220b57cec5SDimitry Andric } 7230b57cec5SDimitry Andric this->sections[i] = &InputSection::discarded; 7240b57cec5SDimitry Andric continue; 7250b57cec5SDimitry Andric } 7260b57cec5SDimitry Andric 7270b57cec5SDimitry Andric switch (sec.sh_type) { 7280b57cec5SDimitry Andric case SHT_GROUP: { 729*bdd1243dSDimitry Andric if (!config->relocatable) 730*bdd1243dSDimitry Andric sections[i] = &InputSection::discarded; 731*bdd1243dSDimitry Andric StringRef signature = 732*bdd1243dSDimitry Andric cantFail(this->getELFSyms<ELFT>()[sec.sh_info].getName(stringTable)); 7330b57cec5SDimitry Andric ArrayRef<Elf_Word> entries = 734*bdd1243dSDimitry Andric cantFail(obj.template getSectionContentsAsArray<Elf_Word>(sec)); 735*bdd1243dSDimitry Andric if ((entries[0] & GRP_COMDAT) == 0 || ignoreComdats || 736*bdd1243dSDimitry Andric symtab.comdatGroups.find(CachedHashStringRef(signature))->second == 737*bdd1243dSDimitry Andric this) 738480093f4SDimitry Andric selectedGroups.push_back(entries); 7390b57cec5SDimitry Andric break; 7400b57cec5SDimitry Andric } 7410b57cec5SDimitry Andric case SHT_SYMTAB_SHNDX: 7420b57cec5SDimitry Andric shndxTable = CHECK(obj.getSHNDXTable(sec, objSections), this); 7430b57cec5SDimitry Andric break; 7440b57cec5SDimitry Andric case SHT_SYMTAB: 7450b57cec5SDimitry Andric case SHT_STRTAB: 7465ffd83dbSDimitry Andric case SHT_REL: 7475ffd83dbSDimitry Andric case SHT_RELA: 7480b57cec5SDimitry Andric case SHT_NULL: 7490b57cec5SDimitry Andric break; 75081ad6265SDimitry Andric case SHT_LLVM_SYMPART: 751*bdd1243dSDimitry Andric ctx.hasSympart.store(true, std::memory_order_relaxed); 752*bdd1243dSDimitry Andric [[fallthrough]]; 7530b57cec5SDimitry Andric default: 7541fd87a68SDimitry Andric this->sections[i] = 7551fd87a68SDimitry Andric createInputSection(i, sec, check(obj.getSectionName(sec, shstrtab))); 7560b57cec5SDimitry Andric } 75785868e8aSDimitry Andric } 75885868e8aSDimitry Andric 7595ffd83dbSDimitry Andric // We have a second loop. It is used to: 7605ffd83dbSDimitry Andric // 1) handle SHF_LINK_ORDER sections. 7615ffd83dbSDimitry Andric // 2) create SHT_REL[A] sections. In some cases the section header index of a 7625ffd83dbSDimitry Andric // relocation section may be smaller than that of the relocated section. In 7635ffd83dbSDimitry Andric // such cases, the relocation section would attempt to reference a target 7645ffd83dbSDimitry Andric // section that has not yet been created. For simplicity, delay creation of 7655ffd83dbSDimitry Andric // relocation sections until now. 76604eeddc0SDimitry Andric for (size_t i = 0; i != size; ++i) { 76785868e8aSDimitry Andric if (this->sections[i] == &InputSection::discarded) 76885868e8aSDimitry Andric continue; 76985868e8aSDimitry Andric const Elf_Shdr &sec = objSections[i]; 7705ffd83dbSDimitry Andric 77104eeddc0SDimitry Andric if (sec.sh_type == SHT_REL || sec.sh_type == SHT_RELA) { 77204eeddc0SDimitry Andric // Find a relocation target section and associate this section with that. 77304eeddc0SDimitry Andric // Target may have been discarded if it is in a different section group 77404eeddc0SDimitry Andric // and the group is discarded, even though it's a violation of the spec. 77504eeddc0SDimitry Andric // We handle that situation gracefully by discarding dangling relocation 77604eeddc0SDimitry Andric // sections. 77704eeddc0SDimitry Andric const uint32_t info = sec.sh_info; 77804eeddc0SDimitry Andric InputSectionBase *s = getRelocTarget(i, sec, info); 77904eeddc0SDimitry Andric if (!s) 78004eeddc0SDimitry Andric continue; 78104eeddc0SDimitry Andric 78204eeddc0SDimitry Andric // ELF spec allows mergeable sections with relocations, but they are rare, 78304eeddc0SDimitry Andric // and it is in practice hard to merge such sections by contents, because 78404eeddc0SDimitry Andric // applying relocations at end of linking changes section contents. So, we 78504eeddc0SDimitry Andric // simply handle such sections as non-mergeable ones. Degrading like this 78604eeddc0SDimitry Andric // is acceptable because section merging is optional. 78704eeddc0SDimitry Andric if (auto *ms = dyn_cast<MergeInputSection>(s)) { 788*bdd1243dSDimitry Andric s = makeThreadLocal<InputSection>( 789*bdd1243dSDimitry Andric ms->file, ms->flags, ms->type, ms->addralign, 790*bdd1243dSDimitry Andric ms->contentMaybeDecompress(), ms->name); 79104eeddc0SDimitry Andric sections[info] = s; 79204eeddc0SDimitry Andric } 79304eeddc0SDimitry Andric 79404eeddc0SDimitry Andric if (s->relSecIdx != 0) 79504eeddc0SDimitry Andric error( 79604eeddc0SDimitry Andric toString(s) + 79704eeddc0SDimitry Andric ": multiple relocation sections to one section are not supported"); 79804eeddc0SDimitry Andric s->relSecIdx = i; 79904eeddc0SDimitry Andric 80004eeddc0SDimitry Andric // Relocation sections are usually removed from the output, so return 80104eeddc0SDimitry Andric // `nullptr` for the normal case. However, if -r or --emit-relocs is 80204eeddc0SDimitry Andric // specified, we need to copy them to the output. (Some post link analysis 80304eeddc0SDimitry Andric // tools specify --emit-relocs to obtain the information.) 80404eeddc0SDimitry Andric if (config->copyRelocs) { 805*bdd1243dSDimitry Andric auto *isec = makeThreadLocal<InputSection>( 80604eeddc0SDimitry Andric *this, sec, check(obj.getSectionName(sec, shstrtab))); 80704eeddc0SDimitry Andric // If the relocated section is discarded (due to /DISCARD/ or 80804eeddc0SDimitry Andric // --gc-sections), the relocation section should be discarded as well. 80904eeddc0SDimitry Andric s->dependentSections.push_back(isec); 81004eeddc0SDimitry Andric sections[i] = isec; 81104eeddc0SDimitry Andric } 81204eeddc0SDimitry Andric continue; 81304eeddc0SDimitry Andric } 8145ffd83dbSDimitry Andric 815e8d8bef9SDimitry Andric // A SHF_LINK_ORDER section with sh_link=0 is handled as if it did not have 816e8d8bef9SDimitry Andric // the flag. 81704eeddc0SDimitry Andric if (!sec.sh_link || !(sec.sh_flags & SHF_LINK_ORDER)) 81885868e8aSDimitry Andric continue; 8190b57cec5SDimitry Andric 8200b57cec5SDimitry Andric InputSectionBase *linkSec = nullptr; 82104eeddc0SDimitry Andric if (sec.sh_link < size) 8220b57cec5SDimitry Andric linkSec = this->sections[sec.sh_link]; 8230b57cec5SDimitry Andric if (!linkSec) 82485868e8aSDimitry Andric fatal(toString(this) + ": invalid sh_link index: " + Twine(sec.sh_link)); 8250b57cec5SDimitry Andric 826e8d8bef9SDimitry Andric // A SHF_LINK_ORDER section is discarded if its linked-to section is 827e8d8bef9SDimitry Andric // discarded. 8280b57cec5SDimitry Andric InputSection *isec = cast<InputSection>(this->sections[i]); 8290b57cec5SDimitry Andric linkSec->dependentSections.push_back(isec); 8300b57cec5SDimitry Andric if (!isa<InputSection>(linkSec)) 8310b57cec5SDimitry Andric error("a section " + isec->name + 83285868e8aSDimitry Andric " with SHF_LINK_ORDER should not refer a non-regular section: " + 8330b57cec5SDimitry Andric toString(linkSec)); 8340b57cec5SDimitry Andric } 835480093f4SDimitry Andric 836480093f4SDimitry Andric for (ArrayRef<Elf_Word> entries : selectedGroups) 837480093f4SDimitry Andric handleSectionGroup<ELFT>(this->sections, entries); 8380b57cec5SDimitry Andric } 8390b57cec5SDimitry Andric 8400b57cec5SDimitry Andric // If a source file is compiled with x86 hardware-assisted call flow control 8410b57cec5SDimitry Andric // enabled, the generated object file contains feature flags indicating that 8420b57cec5SDimitry Andric // fact. This function reads the feature flags and returns it. 8430b57cec5SDimitry Andric // 8440b57cec5SDimitry Andric // Essentially we want to read a single 32-bit value in this function, but this 8450b57cec5SDimitry Andric // function is rather complicated because the value is buried deep inside a 8460b57cec5SDimitry Andric // .note.gnu.property section. 8470b57cec5SDimitry Andric // 8480b57cec5SDimitry Andric // The section consists of one or more NOTE records. Each NOTE record consists 8490b57cec5SDimitry Andric // of zero or more type-length-value fields. We want to find a field of a 8500b57cec5SDimitry Andric // certain type. It seems a bit too much to just store a 32-bit value, perhaps 8510b57cec5SDimitry Andric // the ABI is unnecessarily complicated. 852e8d8bef9SDimitry Andric template <class ELFT> static uint32_t readAndFeatures(const InputSection &sec) { 8530b57cec5SDimitry Andric using Elf_Nhdr = typename ELFT::Nhdr; 8540b57cec5SDimitry Andric using Elf_Note = typename ELFT::Note; 8550b57cec5SDimitry Andric 8560b57cec5SDimitry Andric uint32_t featuresSet = 0; 857*bdd1243dSDimitry Andric ArrayRef<uint8_t> data = sec.content(); 858e8d8bef9SDimitry Andric auto reportFatal = [&](const uint8_t *place, const char *msg) { 859e8d8bef9SDimitry Andric fatal(toString(sec.file) + ":(" + sec.name + "+0x" + 860*bdd1243dSDimitry Andric Twine::utohexstr(place - sec.content().data()) + "): " + msg); 861e8d8bef9SDimitry Andric }; 8620b57cec5SDimitry Andric while (!data.empty()) { 8630b57cec5SDimitry Andric // Read one NOTE record. 8640b57cec5SDimitry Andric auto *nhdr = reinterpret_cast<const Elf_Nhdr *>(data.data()); 865e8d8bef9SDimitry Andric if (data.size() < sizeof(Elf_Nhdr) || data.size() < nhdr->getSize()) 866e8d8bef9SDimitry Andric reportFatal(data.data(), "data is too short"); 8670b57cec5SDimitry Andric 8680b57cec5SDimitry Andric Elf_Note note(*nhdr); 8690b57cec5SDimitry Andric if (nhdr->n_type != NT_GNU_PROPERTY_TYPE_0 || note.getName() != "GNU") { 8700b57cec5SDimitry Andric data = data.slice(nhdr->getSize()); 8710b57cec5SDimitry Andric continue; 8720b57cec5SDimitry Andric } 8730b57cec5SDimitry Andric 8740b57cec5SDimitry Andric uint32_t featureAndType = config->emachine == EM_AARCH64 8750b57cec5SDimitry Andric ? GNU_PROPERTY_AARCH64_FEATURE_1_AND 8760b57cec5SDimitry Andric : GNU_PROPERTY_X86_FEATURE_1_AND; 8770b57cec5SDimitry Andric 8780b57cec5SDimitry Andric // Read a body of a NOTE record, which consists of type-length-value fields. 8790b57cec5SDimitry Andric ArrayRef<uint8_t> desc = note.getDesc(); 8800b57cec5SDimitry Andric while (!desc.empty()) { 881e8d8bef9SDimitry Andric const uint8_t *place = desc.data(); 8820b57cec5SDimitry Andric if (desc.size() < 8) 883e8d8bef9SDimitry Andric reportFatal(place, "program property is too short"); 884e8d8bef9SDimitry Andric uint32_t type = read32<ELFT::TargetEndianness>(desc.data()); 885e8d8bef9SDimitry Andric uint32_t size = read32<ELFT::TargetEndianness>(desc.data() + 4); 886e8d8bef9SDimitry Andric desc = desc.slice(8); 887e8d8bef9SDimitry Andric if (desc.size() < size) 888e8d8bef9SDimitry Andric reportFatal(place, "program property is too short"); 8890b57cec5SDimitry Andric 8900b57cec5SDimitry Andric if (type == featureAndType) { 8910b57cec5SDimitry Andric // We found a FEATURE_1_AND field. There may be more than one of these 892480093f4SDimitry Andric // in a .note.gnu.property section, for a relocatable object we 8930b57cec5SDimitry Andric // accumulate the bits set. 894e8d8bef9SDimitry Andric if (size < 4) 895e8d8bef9SDimitry Andric reportFatal(place, "FEATURE_1_AND entry is too short"); 896e8d8bef9SDimitry Andric featuresSet |= read32<ELFT::TargetEndianness>(desc.data()); 8970b57cec5SDimitry Andric } 8980b57cec5SDimitry Andric 899e8d8bef9SDimitry Andric // Padding is present in the note descriptor, if necessary. 900e8d8bef9SDimitry Andric desc = desc.slice(alignTo<(ELFT::Is64Bits ? 8 : 4)>(size)); 9010b57cec5SDimitry Andric } 9020b57cec5SDimitry Andric 9030b57cec5SDimitry Andric // Go to next NOTE record to look for more FEATURE_1_AND descriptions. 9040b57cec5SDimitry Andric data = data.slice(nhdr->getSize()); 9050b57cec5SDimitry Andric } 9060b57cec5SDimitry Andric 9070b57cec5SDimitry Andric return featuresSet; 9080b57cec5SDimitry Andric } 9090b57cec5SDimitry Andric 9100b57cec5SDimitry Andric template <class ELFT> 91104eeddc0SDimitry Andric InputSectionBase *ObjFile<ELFT>::getRelocTarget(uint32_t idx, 91204eeddc0SDimitry Andric const Elf_Shdr &sec, 91304eeddc0SDimitry Andric uint32_t info) { 914349cc55cSDimitry Andric if (info < this->sections.size()) { 915349cc55cSDimitry Andric InputSectionBase *target = this->sections[info]; 9160b57cec5SDimitry Andric 9170b57cec5SDimitry Andric // Strictly speaking, a relocation section must be included in the 9180b57cec5SDimitry Andric // group of the section it relocates. However, LLVM 3.3 and earlier 9190b57cec5SDimitry Andric // would fail to do so, so we gracefully handle that case. 9200b57cec5SDimitry Andric if (target == &InputSection::discarded) 9210b57cec5SDimitry Andric return nullptr; 9220b57cec5SDimitry Andric 923349cc55cSDimitry Andric if (target != nullptr) 9240b57cec5SDimitry Andric return target; 9250b57cec5SDimitry Andric } 9260b57cec5SDimitry Andric 92704eeddc0SDimitry Andric error(toString(this) + Twine(": relocation section (index ") + Twine(idx) + 92804eeddc0SDimitry Andric ") has invalid sh_info (" + Twine(info) + ")"); 929349cc55cSDimitry Andric return nullptr; 930349cc55cSDimitry Andric } 931349cc55cSDimitry Andric 932*bdd1243dSDimitry Andric // The function may be called concurrently for different input files. For 933*bdd1243dSDimitry Andric // allocation, prefer makeThreadLocal which does not require holding a lock. 9340b57cec5SDimitry Andric template <class ELFT> 935349cc55cSDimitry Andric InputSectionBase *ObjFile<ELFT>::createInputSection(uint32_t idx, 936349cc55cSDimitry Andric const Elf_Shdr &sec, 9371fd87a68SDimitry Andric StringRef name) { 9380eae32dcSDimitry Andric if (name.startswith(".n")) { 9390b57cec5SDimitry Andric // The GNU linker uses .note.GNU-stack section as a marker indicating 9400b57cec5SDimitry Andric // that the code in the object file does not expect that the stack is 9410b57cec5SDimitry Andric // executable (in terms of NX bit). If all input files have the marker, 9420b57cec5SDimitry Andric // the GNU linker adds a PT_GNU_STACK segment to tells the loader to 9430b57cec5SDimitry Andric // make the stack non-executable. Most object files have this section as 9440b57cec5SDimitry Andric // of 2017. 9450b57cec5SDimitry Andric // 9460b57cec5SDimitry Andric // But making the stack non-executable is a norm today for security 9470b57cec5SDimitry Andric // reasons. Failure to do so may result in a serious security issue. 9480b57cec5SDimitry Andric // Therefore, we make LLD always add PT_GNU_STACK unless it is 9490b57cec5SDimitry Andric // explicitly told to do otherwise (by -z execstack). Because the stack 9500b57cec5SDimitry Andric // executable-ness is controlled solely by command line options, 9510b57cec5SDimitry Andric // .note.GNU-stack sections are simply ignored. 9520b57cec5SDimitry Andric if (name == ".note.GNU-stack") 9530b57cec5SDimitry Andric return &InputSection::discarded; 9540b57cec5SDimitry Andric 9550b57cec5SDimitry Andric // Object files that use processor features such as Intel Control-Flow 9560b57cec5SDimitry Andric // Enforcement (CET) or AArch64 Branch Target Identification BTI, use a 9570b57cec5SDimitry Andric // .note.gnu.property section containing a bitfield of feature bits like the 9580b57cec5SDimitry Andric // GNU_PROPERTY_X86_FEATURE_1_IBT flag. Read a bitmap containing the flag. 9590b57cec5SDimitry Andric // 9600b57cec5SDimitry Andric // Since we merge bitmaps from multiple object files to create a new 9610b57cec5SDimitry Andric // .note.gnu.property containing a single AND'ed bitmap, we discard an input 9620b57cec5SDimitry Andric // file's .note.gnu.property section. 9630b57cec5SDimitry Andric if (name == ".note.gnu.property") { 964e8d8bef9SDimitry Andric this->andFeatures = readAndFeatures<ELFT>(InputSection(*this, sec, name)); 9650b57cec5SDimitry Andric return &InputSection::discarded; 9660b57cec5SDimitry Andric } 9670b57cec5SDimitry Andric 9680b57cec5SDimitry Andric // Split stacks is a feature to support a discontiguous stack, 9690b57cec5SDimitry Andric // commonly used in the programming language Go. For the details, 9700b57cec5SDimitry Andric // see https://gcc.gnu.org/wiki/SplitStacks. An object file compiled 9710b57cec5SDimitry Andric // for split stack will include a .note.GNU-split-stack section. 9720b57cec5SDimitry Andric if (name == ".note.GNU-split-stack") { 9730b57cec5SDimitry Andric if (config->relocatable) { 9740eae32dcSDimitry Andric error( 9750eae32dcSDimitry Andric "cannot mix split-stack and non-split-stack in a relocatable link"); 9760b57cec5SDimitry Andric return &InputSection::discarded; 9770b57cec5SDimitry Andric } 9780b57cec5SDimitry Andric this->splitStack = true; 9790b57cec5SDimitry Andric return &InputSection::discarded; 9800b57cec5SDimitry Andric } 9810b57cec5SDimitry Andric 982*bdd1243dSDimitry Andric // An object file compiled for split stack, but where some of the 9830b57cec5SDimitry Andric // functions were compiled with the no_split_stack_attribute will 9840b57cec5SDimitry Andric // include a .note.GNU-no-split-stack section. 9850b57cec5SDimitry Andric if (name == ".note.GNU-no-split-stack") { 9860b57cec5SDimitry Andric this->someNoSplitStack = true; 9870b57cec5SDimitry Andric return &InputSection::discarded; 9880b57cec5SDimitry Andric } 9890b57cec5SDimitry Andric 9900eae32dcSDimitry Andric // Strip existing .note.gnu.build-id sections so that the output won't have 9910eae32dcSDimitry Andric // more than one build-id. This is not usually a problem because input 9920eae32dcSDimitry Andric // object files normally don't have .build-id sections, but you can create 9930eae32dcSDimitry Andric // such files by "ld.{bfd,gold,lld} -r --build-id", and we want to guard 9940eae32dcSDimitry Andric // against it. 9950eae32dcSDimitry Andric if (name == ".note.gnu.build-id") 9960eae32dcSDimitry Andric return &InputSection::discarded; 9970eae32dcSDimitry Andric } 9980eae32dcSDimitry Andric 9990b57cec5SDimitry Andric // The linker merges EH (exception handling) frames and creates a 10000b57cec5SDimitry Andric // .eh_frame_hdr section for runtime. So we handle them with a special 10010b57cec5SDimitry Andric // class. For relocatable outputs, they are just passed through. 10020b57cec5SDimitry Andric if (name == ".eh_frame" && !config->relocatable) 1003*bdd1243dSDimitry Andric return makeThreadLocal<EhInputSection>(*this, sec, name); 10040b57cec5SDimitry Andric 10050eae32dcSDimitry Andric if ((sec.sh_flags & SHF_MERGE) && shouldMerge(sec, name)) 1006*bdd1243dSDimitry Andric return makeThreadLocal<MergeInputSection>(*this, sec, name); 1007*bdd1243dSDimitry Andric return makeThreadLocal<InputSection>(*this, sec, name); 10080b57cec5SDimitry Andric } 10090b57cec5SDimitry Andric 10100b57cec5SDimitry Andric // Initialize this->Symbols. this->Symbols is a parallel array as 10110b57cec5SDimitry Andric // its corresponding ELF symbol table. 10121fd87a68SDimitry Andric template <class ELFT> 10131fd87a68SDimitry Andric void ObjFile<ELFT>::initializeSymbols(const object::ELFFile<ELFT> &obj) { 10140eae32dcSDimitry Andric ArrayRef<Elf_Sym> eSyms = this->getELFSyms<ELFT>(); 1015*bdd1243dSDimitry Andric if (numSymbols == 0) { 1016*bdd1243dSDimitry Andric numSymbols = eSyms.size(); 1017*bdd1243dSDimitry Andric symbols = std::make_unique<Symbol *[]>(numSymbols); 1018*bdd1243dSDimitry Andric } 10190eae32dcSDimitry Andric 102081ad6265SDimitry Andric // Some entries have been filled by LazyObjFile. 102181ad6265SDimitry Andric for (size_t i = firstGlobal, end = eSyms.size(); i != end; ++i) 102281ad6265SDimitry Andric if (!symbols[i]) 102381ad6265SDimitry Andric symbols[i] = symtab.insert(CHECK(eSyms[i].getName(stringTable), this)); 102481ad6265SDimitry Andric 102581ad6265SDimitry Andric // Perform symbol resolution on non-local symbols. 102681ad6265SDimitry Andric SmallVector<unsigned, 32> undefineds; 102781ad6265SDimitry Andric for (size_t i = firstGlobal, end = eSyms.size(); i != end; ++i) { 102881ad6265SDimitry Andric const Elf_Sym &eSym = eSyms[i]; 102981ad6265SDimitry Andric uint32_t secIdx = eSym.st_shndx; 103081ad6265SDimitry Andric if (secIdx == SHN_UNDEF) { 103181ad6265SDimitry Andric undefineds.push_back(i); 103281ad6265SDimitry Andric continue; 103381ad6265SDimitry Andric } 103481ad6265SDimitry Andric 103581ad6265SDimitry Andric uint8_t binding = eSym.getBinding(); 103681ad6265SDimitry Andric uint8_t stOther = eSym.st_other; 103781ad6265SDimitry Andric uint8_t type = eSym.getType(); 103881ad6265SDimitry Andric uint64_t value = eSym.st_value; 103981ad6265SDimitry Andric uint64_t size = eSym.st_size; 104081ad6265SDimitry Andric 104181ad6265SDimitry Andric Symbol *sym = symbols[i]; 104281ad6265SDimitry Andric sym->isUsedInRegularObj = true; 104381ad6265SDimitry Andric if (LLVM_UNLIKELY(eSym.st_shndx == SHN_COMMON)) { 104481ad6265SDimitry Andric if (value == 0 || value >= UINT32_MAX) 104581ad6265SDimitry Andric fatal(toString(this) + ": common symbol '" + sym->getName() + 104681ad6265SDimitry Andric "' has invalid alignment: " + Twine(value)); 104781ad6265SDimitry Andric hasCommonSyms = true; 104881ad6265SDimitry Andric sym->resolve( 104981ad6265SDimitry Andric CommonSymbol{this, StringRef(), binding, stOther, type, value, size}); 105081ad6265SDimitry Andric continue; 105181ad6265SDimitry Andric } 105281ad6265SDimitry Andric 105381ad6265SDimitry Andric // Handle global defined symbols. Defined::section will be set in postParse. 105481ad6265SDimitry Andric sym->resolve(Defined{this, StringRef(), binding, stOther, type, value, size, 105581ad6265SDimitry Andric nullptr}); 105681ad6265SDimitry Andric } 105781ad6265SDimitry Andric 105881ad6265SDimitry Andric // Undefined symbols (excluding those defined relative to non-prevailing 105981ad6265SDimitry Andric // sections) can trigger recursive extract. Process defined symbols first so 106081ad6265SDimitry Andric // that the relative order between a defined symbol and an undefined symbol 106181ad6265SDimitry Andric // does not change the symbol resolution behavior. In addition, a set of 106281ad6265SDimitry Andric // interconnected symbols will all be resolved to the same file, instead of 106381ad6265SDimitry Andric // being resolved to different files. 106481ad6265SDimitry Andric for (unsigned i : undefineds) { 106581ad6265SDimitry Andric const Elf_Sym &eSym = eSyms[i]; 106681ad6265SDimitry Andric Symbol *sym = symbols[i]; 106781ad6265SDimitry Andric sym->resolve(Undefined{this, StringRef(), eSym.getBinding(), eSym.st_other, 106881ad6265SDimitry Andric eSym.getType()}); 106981ad6265SDimitry Andric sym->isUsedInRegularObj = true; 107081ad6265SDimitry Andric sym->referenced = true; 107181ad6265SDimitry Andric } 107281ad6265SDimitry Andric } 107381ad6265SDimitry Andric 1074*bdd1243dSDimitry Andric template <class ELFT> 1075*bdd1243dSDimitry Andric void ObjFile<ELFT>::initSectionsAndLocalSyms(bool ignoreComdats) { 1076*bdd1243dSDimitry Andric if (!justSymbols) 1077*bdd1243dSDimitry Andric initializeSections(ignoreComdats, getObj()); 1078*bdd1243dSDimitry Andric 107981ad6265SDimitry Andric if (!firstGlobal) 108081ad6265SDimitry Andric return; 1081*bdd1243dSDimitry Andric SymbolUnion *locals = makeThreadLocalN<SymbolUnion>(firstGlobal); 1082*bdd1243dSDimitry Andric memset(locals, 0, sizeof(SymbolUnion) * firstGlobal); 108381ad6265SDimitry Andric 108481ad6265SDimitry Andric ArrayRef<Elf_Sym> eSyms = this->getELFSyms<ELFT>(); 10850eae32dcSDimitry Andric for (size_t i = 0, end = firstGlobal; i != end; ++i) { 10860b57cec5SDimitry Andric const Elf_Sym &eSym = eSyms[i]; 10871fd87a68SDimitry Andric uint32_t secIdx = eSym.st_shndx; 10881fd87a68SDimitry Andric if (LLVM_UNLIKELY(secIdx == SHN_XINDEX)) 10891fd87a68SDimitry Andric secIdx = check(getExtendedSymbolTableIndex<ELFT>(eSym, i, shndxTable)); 10901fd87a68SDimitry Andric else if (secIdx >= SHN_LORESERVE) 10911fd87a68SDimitry Andric secIdx = 0; 10920eae32dcSDimitry Andric if (LLVM_UNLIKELY(secIdx >= sections.size())) 10930b57cec5SDimitry Andric fatal(toString(this) + ": invalid section index: " + Twine(secIdx)); 10940eae32dcSDimitry Andric if (LLVM_UNLIKELY(eSym.getBinding() != STB_LOCAL)) 10955ffd83dbSDimitry Andric error(toString(this) + ": non-local symbol (" + Twine(i) + 10960eae32dcSDimitry Andric ") found at index < .symtab's sh_info (" + Twine(end) + ")"); 10975ffd83dbSDimitry Andric 10980eae32dcSDimitry Andric InputSectionBase *sec = sections[secIdx]; 10995ffd83dbSDimitry Andric uint8_t type = eSym.getType(); 11005ffd83dbSDimitry Andric if (type == STT_FILE) 11010eae32dcSDimitry Andric sourceFile = CHECK(eSym.getName(stringTable), this); 11020eae32dcSDimitry Andric if (LLVM_UNLIKELY(stringTable.size() <= eSym.st_name)) 11035ffd83dbSDimitry Andric fatal(toString(this) + ": invalid symbol name offset"); 110404eeddc0SDimitry Andric StringRef name(stringTable.data() + eSym.st_name); 11055ffd83dbSDimitry Andric 11060eae32dcSDimitry Andric symbols[i] = reinterpret_cast<Symbol *>(locals + i); 11070eae32dcSDimitry Andric if (eSym.st_shndx == SHN_UNDEF || sec == &InputSection::discarded) 11080eae32dcSDimitry Andric new (symbols[i]) Undefined(this, name, STB_LOCAL, eSym.st_other, type, 11095ffd83dbSDimitry Andric /*discardedSecIdx=*/secIdx); 11105ffd83dbSDimitry Andric else 11110eae32dcSDimitry Andric new (symbols[i]) Defined(this, name, STB_LOCAL, eSym.st_other, type, 11120eae32dcSDimitry Andric eSym.st_value, eSym.st_size, sec); 1113*bdd1243dSDimitry Andric symbols[i]->partition = 1; 111481ad6265SDimitry Andric symbols[i]->isUsedInRegularObj = true; 111581ad6265SDimitry Andric } 11165ffd83dbSDimitry Andric } 11175ffd83dbSDimitry Andric 111881ad6265SDimitry Andric // Called after all ObjFile::parse is called for all ObjFiles. This checks 111981ad6265SDimitry Andric // duplicate symbols and may do symbol property merge in the future. 112081ad6265SDimitry Andric template <class ELFT> void ObjFile<ELFT>::postParse() { 112181ad6265SDimitry Andric static std::mutex mu; 112281ad6265SDimitry Andric ArrayRef<Elf_Sym> eSyms = this->getELFSyms<ELFT>(); 11235ffd83dbSDimitry Andric for (size_t i = firstGlobal, end = eSyms.size(); i != end; ++i) { 11245ffd83dbSDimitry Andric const Elf_Sym &eSym = eSyms[i]; 112581ad6265SDimitry Andric Symbol &sym = *symbols[i]; 11261fd87a68SDimitry Andric uint32_t secIdx = eSym.st_shndx; 112781ad6265SDimitry Andric uint8_t binding = eSym.getBinding(); 112881ad6265SDimitry Andric if (LLVM_UNLIKELY(binding != STB_GLOBAL && binding != STB_WEAK && 112981ad6265SDimitry Andric binding != STB_GNU_UNIQUE)) 113081ad6265SDimitry Andric errorOrWarn(toString(this) + ": symbol (" + Twine(i) + 113181ad6265SDimitry Andric ") has invalid binding: " + Twine((int)binding)); 113281ad6265SDimitry Andric 113381ad6265SDimitry Andric // st_value of STT_TLS represents the assigned offset, not the actual 113481ad6265SDimitry Andric // address which is used by STT_FUNC and STT_OBJECT. STT_TLS symbols can 113581ad6265SDimitry Andric // only be referenced by special TLS relocations. It is usually an error if 113681ad6265SDimitry Andric // a STT_TLS symbol is replaced by a non-STT_TLS symbol, vice versa. 113781ad6265SDimitry Andric if (LLVM_UNLIKELY(sym.isTls()) && eSym.getType() != STT_TLS && 113881ad6265SDimitry Andric eSym.getType() != STT_NOTYPE) 113981ad6265SDimitry Andric errorOrWarn("TLS attribute mismatch: " + toString(sym) + "\n>>> in " + 114081ad6265SDimitry Andric toString(sym.file) + "\n>>> in " + toString(this)); 114181ad6265SDimitry Andric 114281ad6265SDimitry Andric // Handle non-COMMON defined symbol below. !sym.file allows a symbol 114381ad6265SDimitry Andric // assignment to redefine a symbol without an error. 114481ad6265SDimitry Andric if (!sym.file || !sym.isDefined() || secIdx == SHN_UNDEF || 114581ad6265SDimitry Andric secIdx == SHN_COMMON) 114681ad6265SDimitry Andric continue; 114781ad6265SDimitry Andric 11481fd87a68SDimitry Andric if (LLVM_UNLIKELY(secIdx == SHN_XINDEX)) 11491fd87a68SDimitry Andric secIdx = check(getExtendedSymbolTableIndex<ELFT>(eSym, i, shndxTable)); 11501fd87a68SDimitry Andric else if (secIdx >= SHN_LORESERVE) 11511fd87a68SDimitry Andric secIdx = 0; 11520eae32dcSDimitry Andric if (LLVM_UNLIKELY(secIdx >= sections.size())) 11530eae32dcSDimitry Andric fatal(toString(this) + ": invalid section index: " + Twine(secIdx)); 11540eae32dcSDimitry Andric InputSectionBase *sec = sections[secIdx]; 11550b57cec5SDimitry Andric if (sec == &InputSection::discarded) { 115681ad6265SDimitry Andric if (sym.traced) { 115781ad6265SDimitry Andric printTraceSymbol(Undefined{this, sym.getName(), sym.binding, 115881ad6265SDimitry Andric sym.stOther, sym.type, secIdx}, 115981ad6265SDimitry Andric sym.getName()); 116081ad6265SDimitry Andric } 116181ad6265SDimitry Andric if (sym.file == this) { 116281ad6265SDimitry Andric std::lock_guard<std::mutex> lock(mu); 1163*bdd1243dSDimitry Andric ctx.nonPrevailingSyms.emplace_back(&sym, secIdx); 116481ad6265SDimitry Andric } 11650b57cec5SDimitry Andric continue; 11660b57cec5SDimitry Andric } 11670b57cec5SDimitry Andric 116881ad6265SDimitry Andric if (sym.file == this) { 116981ad6265SDimitry Andric cast<Defined>(sym).section = sec; 11700b57cec5SDimitry Andric continue; 11710b57cec5SDimitry Andric } 11720b57cec5SDimitry Andric 1173f3fd488fSDimitry Andric if (sym.binding == STB_WEAK || binding == STB_WEAK) 117481ad6265SDimitry Andric continue; 117581ad6265SDimitry Andric std::lock_guard<std::mutex> lock(mu); 1176*bdd1243dSDimitry Andric ctx.duplicates.push_back({&sym, this, sec, eSym.st_value}); 11770b57cec5SDimitry Andric } 11780b57cec5SDimitry Andric } 11790b57cec5SDimitry Andric 1180e8d8bef9SDimitry Andric // The handling of tentative definitions (COMMON symbols) in archives is murky. 1181fe6060f1SDimitry Andric // A tentative definition will be promoted to a global definition if there are 1182fe6060f1SDimitry Andric // no non-tentative definitions to dominate it. When we hold a tentative 1183fe6060f1SDimitry Andric // definition to a symbol and are inspecting archive members for inclusion 1184fe6060f1SDimitry Andric // there are 2 ways we can proceed: 1185e8d8bef9SDimitry Andric // 1186e8d8bef9SDimitry Andric // 1) Consider the tentative definition a 'real' definition (ie promotion from 1187e8d8bef9SDimitry Andric // tentative to real definition has already happened) and not inspect 1188e8d8bef9SDimitry Andric // archive members for Global/Weak definitions to replace the tentative 1189e8d8bef9SDimitry Andric // definition. An archive member would only be included if it satisfies some 1190e8d8bef9SDimitry Andric // other undefined symbol. This is the behavior Gold uses. 1191e8d8bef9SDimitry Andric // 1192e8d8bef9SDimitry Andric // 2) Consider the tentative definition as still undefined (ie the promotion to 1193fe6060f1SDimitry Andric // a real definition happens only after all symbol resolution is done). 1194fe6060f1SDimitry Andric // The linker searches archive members for STB_GLOBAL definitions to 1195e8d8bef9SDimitry Andric // replace the tentative definition with. This is the behavior used by 1196e8d8bef9SDimitry Andric // GNU ld. 1197e8d8bef9SDimitry Andric // 1198e8d8bef9SDimitry Andric // The second behavior is inherited from SysVR4, which based it on the FORTRAN 1199fe6060f1SDimitry Andric // COMMON BLOCK model. This behavior is needed for proper initialization in old 1200e8d8bef9SDimitry Andric // (pre F90) FORTRAN code that is packaged into an archive. 1201e8d8bef9SDimitry Andric // 1202fe6060f1SDimitry Andric // The following functions search archive members for definitions to replace 1203fe6060f1SDimitry Andric // tentative definitions (implementing behavior 2). 1204e8d8bef9SDimitry Andric static bool isBitcodeNonCommonDef(MemoryBufferRef mb, StringRef symName, 1205e8d8bef9SDimitry Andric StringRef archiveName) { 1206e8d8bef9SDimitry Andric IRSymtabFile symtabFile = check(readIRSymtab(mb)); 1207e8d8bef9SDimitry Andric for (const irsymtab::Reader::SymbolRef &sym : 1208e8d8bef9SDimitry Andric symtabFile.TheReader.symbols()) { 1209e8d8bef9SDimitry Andric if (sym.isGlobal() && sym.getName() == symName) 1210fe6060f1SDimitry Andric return !sym.isUndefined() && !sym.isWeak() && !sym.isCommon(); 1211e8d8bef9SDimitry Andric } 1212e8d8bef9SDimitry Andric return false; 1213e8d8bef9SDimitry Andric } 1214e8d8bef9SDimitry Andric 1215e8d8bef9SDimitry Andric template <class ELFT> 1216*bdd1243dSDimitry Andric static bool isNonCommonDef(ELFKind ekind, MemoryBufferRef mb, StringRef symName, 1217e8d8bef9SDimitry Andric StringRef archiveName) { 1218*bdd1243dSDimitry Andric ObjFile<ELFT> *obj = make<ObjFile<ELFT>>(ekind, mb, archiveName); 1219*bdd1243dSDimitry Andric obj->init(); 1220e8d8bef9SDimitry Andric StringRef stringtable = obj->getStringTable(); 1221e8d8bef9SDimitry Andric 1222e8d8bef9SDimitry Andric for (auto sym : obj->template getGlobalELFSyms<ELFT>()) { 1223e8d8bef9SDimitry Andric Expected<StringRef> name = sym.getName(stringtable); 1224e8d8bef9SDimitry Andric if (name && name.get() == symName) 1225fe6060f1SDimitry Andric return sym.isDefined() && sym.getBinding() == STB_GLOBAL && 1226fe6060f1SDimitry Andric !sym.isCommon(); 1227e8d8bef9SDimitry Andric } 1228e8d8bef9SDimitry Andric return false; 1229e8d8bef9SDimitry Andric } 1230e8d8bef9SDimitry Andric 1231e8d8bef9SDimitry Andric static bool isNonCommonDef(MemoryBufferRef mb, StringRef symName, 1232e8d8bef9SDimitry Andric StringRef archiveName) { 1233e8d8bef9SDimitry Andric switch (getELFKind(mb, archiveName)) { 1234e8d8bef9SDimitry Andric case ELF32LEKind: 1235*bdd1243dSDimitry Andric return isNonCommonDef<ELF32LE>(ELF32LEKind, mb, symName, archiveName); 1236e8d8bef9SDimitry Andric case ELF32BEKind: 1237*bdd1243dSDimitry Andric return isNonCommonDef<ELF32BE>(ELF32BEKind, mb, symName, archiveName); 1238e8d8bef9SDimitry Andric case ELF64LEKind: 1239*bdd1243dSDimitry Andric return isNonCommonDef<ELF64LE>(ELF64LEKind, mb, symName, archiveName); 1240e8d8bef9SDimitry Andric case ELF64BEKind: 1241*bdd1243dSDimitry Andric return isNonCommonDef<ELF64BE>(ELF64BEKind, mb, symName, archiveName); 1242e8d8bef9SDimitry Andric default: 1243e8d8bef9SDimitry Andric llvm_unreachable("getELFKind"); 1244e8d8bef9SDimitry Andric } 1245e8d8bef9SDimitry Andric } 1246e8d8bef9SDimitry Andric 12470b57cec5SDimitry Andric unsigned SharedFile::vernauxNum; 12480b57cec5SDimitry Andric 1249*bdd1243dSDimitry Andric SharedFile::SharedFile(MemoryBufferRef m, StringRef defaultSoName) 1250*bdd1243dSDimitry Andric : ELFFileBase(SharedKind, getELFKind(m, ""), m), soName(defaultSoName), 1251*bdd1243dSDimitry Andric isNeeded(!config->asNeeded) {} 1252*bdd1243dSDimitry Andric 12530b57cec5SDimitry Andric // Parse the version definitions in the object file if present, and return a 12540b57cec5SDimitry Andric // vector whose nth element contains a pointer to the Elf_Verdef for version 12550b57cec5SDimitry Andric // identifier n. Version identifiers that are not definitions map to nullptr. 12560b57cec5SDimitry Andric template <typename ELFT> 12570eae32dcSDimitry Andric static SmallVector<const void *, 0> 12580eae32dcSDimitry Andric parseVerdefs(const uint8_t *base, const typename ELFT::Shdr *sec) { 12590b57cec5SDimitry Andric if (!sec) 12600b57cec5SDimitry Andric return {}; 12610b57cec5SDimitry Andric 12620b57cec5SDimitry Andric // Build the Verdefs array by following the chain of Elf_Verdef objects 12630b57cec5SDimitry Andric // from the start of the .gnu.version_d section. 12640eae32dcSDimitry Andric SmallVector<const void *, 0> verdefs; 12650b57cec5SDimitry Andric const uint8_t *verdef = base + sec->sh_offset; 12660eae32dcSDimitry Andric for (unsigned i = 0, e = sec->sh_info; i != e; ++i) { 12670b57cec5SDimitry Andric auto *curVerdef = reinterpret_cast<const typename ELFT::Verdef *>(verdef); 12680b57cec5SDimitry Andric verdef += curVerdef->vd_next; 12690b57cec5SDimitry Andric unsigned verdefIndex = curVerdef->vd_ndx; 12700eae32dcSDimitry Andric if (verdefIndex >= verdefs.size()) 12710b57cec5SDimitry Andric verdefs.resize(verdefIndex + 1); 12720b57cec5SDimitry Andric verdefs[verdefIndex] = curVerdef; 12730b57cec5SDimitry Andric } 12740b57cec5SDimitry Andric return verdefs; 12750b57cec5SDimitry Andric } 12760b57cec5SDimitry Andric 12775ffd83dbSDimitry Andric // Parse SHT_GNU_verneed to properly set the name of a versioned undefined 12785ffd83dbSDimitry Andric // symbol. We detect fatal issues which would cause vulnerabilities, but do not 12795ffd83dbSDimitry Andric // implement sophisticated error checking like in llvm-readobj because the value 12805ffd83dbSDimitry Andric // of such diagnostics is low. 12815ffd83dbSDimitry Andric template <typename ELFT> 12825ffd83dbSDimitry Andric std::vector<uint32_t> SharedFile::parseVerneed(const ELFFile<ELFT> &obj, 12835ffd83dbSDimitry Andric const typename ELFT::Shdr *sec) { 12845ffd83dbSDimitry Andric if (!sec) 12855ffd83dbSDimitry Andric return {}; 12865ffd83dbSDimitry Andric std::vector<uint32_t> verneeds; 1287e8d8bef9SDimitry Andric ArrayRef<uint8_t> data = CHECK(obj.getSectionContents(*sec), this); 12885ffd83dbSDimitry Andric const uint8_t *verneedBuf = data.begin(); 12895ffd83dbSDimitry Andric for (unsigned i = 0; i != sec->sh_info; ++i) { 12905ffd83dbSDimitry Andric if (verneedBuf + sizeof(typename ELFT::Verneed) > data.end()) 12915ffd83dbSDimitry Andric fatal(toString(this) + " has an invalid Verneed"); 12925ffd83dbSDimitry Andric auto *vn = reinterpret_cast<const typename ELFT::Verneed *>(verneedBuf); 12935ffd83dbSDimitry Andric const uint8_t *vernauxBuf = verneedBuf + vn->vn_aux; 12945ffd83dbSDimitry Andric for (unsigned j = 0; j != vn->vn_cnt; ++j) { 12955ffd83dbSDimitry Andric if (vernauxBuf + sizeof(typename ELFT::Vernaux) > data.end()) 12965ffd83dbSDimitry Andric fatal(toString(this) + " has an invalid Vernaux"); 12975ffd83dbSDimitry Andric auto *aux = reinterpret_cast<const typename ELFT::Vernaux *>(vernauxBuf); 12985ffd83dbSDimitry Andric if (aux->vna_name >= this->stringTable.size()) 12995ffd83dbSDimitry Andric fatal(toString(this) + " has a Vernaux with an invalid vna_name"); 13005ffd83dbSDimitry Andric uint16_t version = aux->vna_other & VERSYM_VERSION; 13015ffd83dbSDimitry Andric if (version >= verneeds.size()) 13025ffd83dbSDimitry Andric verneeds.resize(version + 1); 13035ffd83dbSDimitry Andric verneeds[version] = aux->vna_name; 13045ffd83dbSDimitry Andric vernauxBuf += aux->vna_next; 13055ffd83dbSDimitry Andric } 13065ffd83dbSDimitry Andric verneedBuf += vn->vn_next; 13075ffd83dbSDimitry Andric } 13085ffd83dbSDimitry Andric return verneeds; 13095ffd83dbSDimitry Andric } 13105ffd83dbSDimitry Andric 13110b57cec5SDimitry Andric // We do not usually care about alignments of data in shared object 13120b57cec5SDimitry Andric // files because the loader takes care of it. However, if we promote a 13130b57cec5SDimitry Andric // DSO symbol to point to .bss due to copy relocation, we need to keep 13140b57cec5SDimitry Andric // the original alignment requirements. We infer it in this function. 13150b57cec5SDimitry Andric template <typename ELFT> 13160b57cec5SDimitry Andric static uint64_t getAlignment(ArrayRef<typename ELFT::Shdr> sections, 13170b57cec5SDimitry Andric const typename ELFT::Sym &sym) { 13180b57cec5SDimitry Andric uint64_t ret = UINT64_MAX; 13190b57cec5SDimitry Andric if (sym.st_value) 13200b57cec5SDimitry Andric ret = 1ULL << countTrailingZeros((uint64_t)sym.st_value); 13210b57cec5SDimitry Andric if (0 < sym.st_shndx && sym.st_shndx < sections.size()) 13220b57cec5SDimitry Andric ret = std::min<uint64_t>(ret, sections[sym.st_shndx].sh_addralign); 13230b57cec5SDimitry Andric return (ret > UINT32_MAX) ? 0 : ret; 13240b57cec5SDimitry Andric } 13250b57cec5SDimitry Andric 13260b57cec5SDimitry Andric // Fully parse the shared object file. 13270b57cec5SDimitry Andric // 13280b57cec5SDimitry Andric // This function parses symbol versions. If a DSO has version information, 13290b57cec5SDimitry Andric // the file has a ".gnu.version_d" section which contains symbol version 13300b57cec5SDimitry Andric // definitions. Each symbol is associated to one version through a table in 13310b57cec5SDimitry Andric // ".gnu.version" section. That table is a parallel array for the symbol 13320b57cec5SDimitry Andric // table, and each table entry contains an index in ".gnu.version_d". 13330b57cec5SDimitry Andric // 13340b57cec5SDimitry Andric // The special index 0 is reserved for VERF_NDX_LOCAL and 1 is for 13350b57cec5SDimitry Andric // VER_NDX_GLOBAL. There's no table entry for these special versions in 13360b57cec5SDimitry Andric // ".gnu.version_d". 13370b57cec5SDimitry Andric // 13380b57cec5SDimitry Andric // The file format for symbol versioning is perhaps a bit more complicated 13390b57cec5SDimitry Andric // than necessary, but you can easily understand the code if you wrap your 13400b57cec5SDimitry Andric // head around the data structure described above. 13410b57cec5SDimitry Andric template <class ELFT> void SharedFile::parse() { 13420b57cec5SDimitry Andric using Elf_Dyn = typename ELFT::Dyn; 13430b57cec5SDimitry Andric using Elf_Shdr = typename ELFT::Shdr; 13440b57cec5SDimitry Andric using Elf_Sym = typename ELFT::Sym; 13450b57cec5SDimitry Andric using Elf_Verdef = typename ELFT::Verdef; 13460b57cec5SDimitry Andric using Elf_Versym = typename ELFT::Versym; 13470b57cec5SDimitry Andric 13480b57cec5SDimitry Andric ArrayRef<Elf_Dyn> dynamicTags; 13490b57cec5SDimitry Andric const ELFFile<ELFT> obj = this->getObj<ELFT>(); 13500eae32dcSDimitry Andric ArrayRef<Elf_Shdr> sections = getELFShdrs<ELFT>(); 13510b57cec5SDimitry Andric 13520b57cec5SDimitry Andric const Elf_Shdr *versymSec = nullptr; 13530b57cec5SDimitry Andric const Elf_Shdr *verdefSec = nullptr; 13545ffd83dbSDimitry Andric const Elf_Shdr *verneedSec = nullptr; 13550b57cec5SDimitry Andric 13560b57cec5SDimitry Andric // Search for .dynsym, .dynamic, .symtab, .gnu.version and .gnu.version_d. 13570b57cec5SDimitry Andric for (const Elf_Shdr &sec : sections) { 13580b57cec5SDimitry Andric switch (sec.sh_type) { 13590b57cec5SDimitry Andric default: 13600b57cec5SDimitry Andric continue; 13610b57cec5SDimitry Andric case SHT_DYNAMIC: 13620b57cec5SDimitry Andric dynamicTags = 1363e8d8bef9SDimitry Andric CHECK(obj.template getSectionContentsAsArray<Elf_Dyn>(sec), this); 13640b57cec5SDimitry Andric break; 13650b57cec5SDimitry Andric case SHT_GNU_versym: 13660b57cec5SDimitry Andric versymSec = &sec; 13670b57cec5SDimitry Andric break; 13680b57cec5SDimitry Andric case SHT_GNU_verdef: 13690b57cec5SDimitry Andric verdefSec = &sec; 13700b57cec5SDimitry Andric break; 13715ffd83dbSDimitry Andric case SHT_GNU_verneed: 13725ffd83dbSDimitry Andric verneedSec = &sec; 13735ffd83dbSDimitry Andric break; 13740b57cec5SDimitry Andric } 13750b57cec5SDimitry Andric } 13760b57cec5SDimitry Andric 13770b57cec5SDimitry Andric if (versymSec && numELFSyms == 0) { 13780b57cec5SDimitry Andric error("SHT_GNU_versym should be associated with symbol table"); 13790b57cec5SDimitry Andric return; 13800b57cec5SDimitry Andric } 13810b57cec5SDimitry Andric 13820b57cec5SDimitry Andric // Search for a DT_SONAME tag to initialize this->soName. 13830b57cec5SDimitry Andric for (const Elf_Dyn &dyn : dynamicTags) { 13840b57cec5SDimitry Andric if (dyn.d_tag == DT_NEEDED) { 13850b57cec5SDimitry Andric uint64_t val = dyn.getVal(); 13860b57cec5SDimitry Andric if (val >= this->stringTable.size()) 13870b57cec5SDimitry Andric fatal(toString(this) + ": invalid DT_NEEDED entry"); 13880b57cec5SDimitry Andric dtNeeded.push_back(this->stringTable.data() + val); 13890b57cec5SDimitry Andric } else if (dyn.d_tag == DT_SONAME) { 13900b57cec5SDimitry Andric uint64_t val = dyn.getVal(); 13910b57cec5SDimitry Andric if (val >= this->stringTable.size()) 13920b57cec5SDimitry Andric fatal(toString(this) + ": invalid DT_SONAME entry"); 13930b57cec5SDimitry Andric soName = this->stringTable.data() + val; 13940b57cec5SDimitry Andric } 13950b57cec5SDimitry Andric } 13960b57cec5SDimitry Andric 13970b57cec5SDimitry Andric // DSOs are uniquified not by filename but by soname. 139804eeddc0SDimitry Andric DenseMap<CachedHashStringRef, SharedFile *>::iterator it; 13990b57cec5SDimitry Andric bool wasInserted; 140004eeddc0SDimitry Andric std::tie(it, wasInserted) = 1401*bdd1243dSDimitry Andric symtab.soNames.try_emplace(CachedHashStringRef(soName), this); 14020b57cec5SDimitry Andric 14030b57cec5SDimitry Andric // If a DSO appears more than once on the command line with and without 14040b57cec5SDimitry Andric // --as-needed, --no-as-needed takes precedence over --as-needed because a 14050b57cec5SDimitry Andric // user can add an extra DSO with --no-as-needed to force it to be added to 14060b57cec5SDimitry Andric // the dependency list. 14070b57cec5SDimitry Andric it->second->isNeeded |= isNeeded; 14080b57cec5SDimitry Andric if (!wasInserted) 14090b57cec5SDimitry Andric return; 14100b57cec5SDimitry Andric 1411*bdd1243dSDimitry Andric ctx.sharedFiles.push_back(this); 14120b57cec5SDimitry Andric 14130b57cec5SDimitry Andric verdefs = parseVerdefs<ELFT>(obj.base(), verdefSec); 14145ffd83dbSDimitry Andric std::vector<uint32_t> verneeds = parseVerneed<ELFT>(obj, verneedSec); 14150b57cec5SDimitry Andric 14160b57cec5SDimitry Andric // Parse ".gnu.version" section which is a parallel array for the symbol 14170b57cec5SDimitry Andric // table. If a given file doesn't have a ".gnu.version" section, we use 14180b57cec5SDimitry Andric // VER_NDX_GLOBAL. 14190b57cec5SDimitry Andric size_t size = numELFSyms - firstGlobal; 14205ffd83dbSDimitry Andric std::vector<uint16_t> versyms(size, VER_NDX_GLOBAL); 14210b57cec5SDimitry Andric if (versymSec) { 14220b57cec5SDimitry Andric ArrayRef<Elf_Versym> versym = 1423e8d8bef9SDimitry Andric CHECK(obj.template getSectionContentsAsArray<Elf_Versym>(*versymSec), 14240b57cec5SDimitry Andric this) 14250b57cec5SDimitry Andric .slice(firstGlobal); 14260b57cec5SDimitry Andric for (size_t i = 0; i < size; ++i) 14270b57cec5SDimitry Andric versyms[i] = versym[i].vs_index; 14280b57cec5SDimitry Andric } 14290b57cec5SDimitry Andric 14300b57cec5SDimitry Andric // System libraries can have a lot of symbols with versions. Using a 14310b57cec5SDimitry Andric // fixed buffer for computing the versions name (foo@ver) can save a 14320b57cec5SDimitry Andric // lot of allocations. 14330b57cec5SDimitry Andric SmallString<0> versionedNameBuffer; 14340b57cec5SDimitry Andric 14350b57cec5SDimitry Andric // Add symbols to the symbol table. 14360b57cec5SDimitry Andric ArrayRef<Elf_Sym> syms = this->getGlobalELFSyms<ELFT>(); 14370eae32dcSDimitry Andric for (size_t i = 0, e = syms.size(); i != e; ++i) { 14380b57cec5SDimitry Andric const Elf_Sym &sym = syms[i]; 14390b57cec5SDimitry Andric 14400b57cec5SDimitry Andric // ELF spec requires that all local symbols precede weak or global 14410b57cec5SDimitry Andric // symbols in each symbol table, and the index of first non-local symbol 14420b57cec5SDimitry Andric // is stored to sh_info. If a local symbol appears after some non-local 14430b57cec5SDimitry Andric // symbol, that's a violation of the spec. 14440eae32dcSDimitry Andric StringRef name = CHECK(sym.getName(stringTable), this); 14450b57cec5SDimitry Andric if (sym.getBinding() == STB_LOCAL) { 1446*bdd1243dSDimitry Andric errorOrWarn(toString(this) + ": invalid local symbol '" + name + 1447*bdd1243dSDimitry Andric "' in global part of symbol table"); 14480b57cec5SDimitry Andric continue; 14490b57cec5SDimitry Andric } 14500b57cec5SDimitry Andric 1451*bdd1243dSDimitry Andric const uint16_t ver = versyms[i], idx = ver & ~VERSYM_HIDDEN; 14520b57cec5SDimitry Andric if (sym.isUndefined()) { 14535ffd83dbSDimitry Andric // For unversioned undefined symbols, VER_NDX_GLOBAL makes more sense but 14545ffd83dbSDimitry Andric // as of binutils 2.34, GNU ld produces VER_NDX_LOCAL. 1455*bdd1243dSDimitry Andric if (ver != VER_NDX_LOCAL && ver != VER_NDX_GLOBAL) { 14565ffd83dbSDimitry Andric if (idx >= verneeds.size()) { 14575ffd83dbSDimitry Andric error("corrupt input file: version need index " + Twine(idx) + 14585ffd83dbSDimitry Andric " for symbol " + name + " is out of bounds\n>>> defined in " + 14595ffd83dbSDimitry Andric toString(this)); 14605ffd83dbSDimitry Andric continue; 14615ffd83dbSDimitry Andric } 14620eae32dcSDimitry Andric StringRef verName = stringTable.data() + verneeds[idx]; 14635ffd83dbSDimitry Andric versionedNameBuffer.clear(); 146404eeddc0SDimitry Andric name = saver().save( 146504eeddc0SDimitry Andric (name + "@" + verName).toStringRef(versionedNameBuffer)); 14665ffd83dbSDimitry Andric } 14670eae32dcSDimitry Andric Symbol *s = symtab.addSymbol( 14680b57cec5SDimitry Andric Undefined{this, name, sym.getBinding(), sym.st_other, sym.getType()}); 14690b57cec5SDimitry Andric s->exportDynamic = true; 14700eae32dcSDimitry Andric if (s->isUndefined() && sym.getBinding() != STB_WEAK && 1471fe6060f1SDimitry Andric config->unresolvedSymbolsInShlib != UnresolvedPolicy::Ignore) 1472fe6060f1SDimitry Andric requiredSymbols.push_back(s); 14730b57cec5SDimitry Andric continue; 14740b57cec5SDimitry Andric } 14750b57cec5SDimitry Andric 1476*bdd1243dSDimitry Andric if (ver == VER_NDX_LOCAL || 1477*bdd1243dSDimitry Andric (ver != VER_NDX_GLOBAL && idx >= verdefs.size())) { 1478*bdd1243dSDimitry Andric // In GNU ld < 2.31 (before 3be08ea4728b56d35e136af4e6fd3086ade17764), the 1479*bdd1243dSDimitry Andric // MIPS port puts _gp_disp symbol into DSO files and incorrectly assigns 1480*bdd1243dSDimitry Andric // VER_NDX_LOCAL. Workaround this bug. 1481*bdd1243dSDimitry Andric if (config->emachine == EM_MIPS && name == "_gp_disp") 14820b57cec5SDimitry Andric continue; 14830b57cec5SDimitry Andric error("corrupt input file: version definition index " + Twine(idx) + 14840b57cec5SDimitry Andric " for symbol " + name + " is out of bounds\n>>> defined in " + 14850b57cec5SDimitry Andric toString(this)); 14860b57cec5SDimitry Andric continue; 14870b57cec5SDimitry Andric } 14880b57cec5SDimitry Andric 1489*bdd1243dSDimitry Andric uint32_t alignment = getAlignment<ELFT>(sections, sym); 1490*bdd1243dSDimitry Andric if (ver == idx) { 1491*bdd1243dSDimitry Andric auto *s = symtab.addSymbol( 1492*bdd1243dSDimitry Andric SharedSymbol{*this, name, sym.getBinding(), sym.st_other, 1493*bdd1243dSDimitry Andric sym.getType(), sym.st_value, sym.st_size, alignment}); 1494*bdd1243dSDimitry Andric if (s->file == this) 1495*bdd1243dSDimitry Andric s->verdefIndex = ver; 1496*bdd1243dSDimitry Andric } 1497*bdd1243dSDimitry Andric 1498*bdd1243dSDimitry Andric // Also add the symbol with the versioned name to handle undefined symbols 1499*bdd1243dSDimitry Andric // with explicit versions. 1500*bdd1243dSDimitry Andric if (ver == VER_NDX_GLOBAL) 1501*bdd1243dSDimitry Andric continue; 1502*bdd1243dSDimitry Andric 15030b57cec5SDimitry Andric StringRef verName = 15040eae32dcSDimitry Andric stringTable.data() + 15050b57cec5SDimitry Andric reinterpret_cast<const Elf_Verdef *>(verdefs[idx])->getAux()->vda_name; 15060b57cec5SDimitry Andric versionedNameBuffer.clear(); 15070b57cec5SDimitry Andric name = (name + "@" + verName).toStringRef(versionedNameBuffer); 150881ad6265SDimitry Andric auto *s = symtab.addSymbol( 150981ad6265SDimitry Andric SharedSymbol{*this, saver().save(name), sym.getBinding(), sym.st_other, 151081ad6265SDimitry Andric sym.getType(), sym.st_value, sym.st_size, alignment}); 151181ad6265SDimitry Andric if (s->file == this) 151281ad6265SDimitry Andric s->verdefIndex = idx; 15130b57cec5SDimitry Andric } 15140b57cec5SDimitry Andric } 15150b57cec5SDimitry Andric 15160b57cec5SDimitry Andric static ELFKind getBitcodeELFKind(const Triple &t) { 15170b57cec5SDimitry Andric if (t.isLittleEndian()) 15180b57cec5SDimitry Andric return t.isArch64Bit() ? ELF64LEKind : ELF32LEKind; 15190b57cec5SDimitry Andric return t.isArch64Bit() ? ELF64BEKind : ELF32BEKind; 15200b57cec5SDimitry Andric } 15210b57cec5SDimitry Andric 1522e8d8bef9SDimitry Andric static uint16_t getBitcodeMachineKind(StringRef path, const Triple &t) { 15230b57cec5SDimitry Andric switch (t.getArch()) { 15240b57cec5SDimitry Andric case Triple::aarch64: 1525fe6060f1SDimitry Andric case Triple::aarch64_be: 15260b57cec5SDimitry Andric return EM_AARCH64; 15270b57cec5SDimitry Andric case Triple::amdgcn: 15280b57cec5SDimitry Andric case Triple::r600: 15290b57cec5SDimitry Andric return EM_AMDGPU; 15300b57cec5SDimitry Andric case Triple::arm: 15310b57cec5SDimitry Andric case Triple::thumb: 15320b57cec5SDimitry Andric return EM_ARM; 15330b57cec5SDimitry Andric case Triple::avr: 15340b57cec5SDimitry Andric return EM_AVR; 1535349cc55cSDimitry Andric case Triple::hexagon: 1536349cc55cSDimitry Andric return EM_HEXAGON; 15370b57cec5SDimitry Andric case Triple::mips: 15380b57cec5SDimitry Andric case Triple::mipsel: 15390b57cec5SDimitry Andric case Triple::mips64: 15400b57cec5SDimitry Andric case Triple::mips64el: 15410b57cec5SDimitry Andric return EM_MIPS; 15420b57cec5SDimitry Andric case Triple::msp430: 15430b57cec5SDimitry Andric return EM_MSP430; 15440b57cec5SDimitry Andric case Triple::ppc: 1545e8d8bef9SDimitry Andric case Triple::ppcle: 15460b57cec5SDimitry Andric return EM_PPC; 15470b57cec5SDimitry Andric case Triple::ppc64: 15480b57cec5SDimitry Andric case Triple::ppc64le: 15490b57cec5SDimitry Andric return EM_PPC64; 15500b57cec5SDimitry Andric case Triple::riscv32: 15510b57cec5SDimitry Andric case Triple::riscv64: 15520b57cec5SDimitry Andric return EM_RISCV; 15530b57cec5SDimitry Andric case Triple::x86: 15540b57cec5SDimitry Andric return t.isOSIAMCU() ? EM_IAMCU : EM_386; 15550b57cec5SDimitry Andric case Triple::x86_64: 15560b57cec5SDimitry Andric return EM_X86_64; 15570b57cec5SDimitry Andric default: 15580b57cec5SDimitry Andric error(path + ": could not infer e_machine from bitcode target triple " + 15590b57cec5SDimitry Andric t.str()); 15600b57cec5SDimitry Andric return EM_NONE; 15610b57cec5SDimitry Andric } 15620b57cec5SDimitry Andric } 15630b57cec5SDimitry Andric 1564e8d8bef9SDimitry Andric static uint8_t getOsAbi(const Triple &t) { 1565e8d8bef9SDimitry Andric switch (t.getOS()) { 1566e8d8bef9SDimitry Andric case Triple::AMDHSA: 1567e8d8bef9SDimitry Andric return ELF::ELFOSABI_AMDGPU_HSA; 1568e8d8bef9SDimitry Andric case Triple::AMDPAL: 1569e8d8bef9SDimitry Andric return ELF::ELFOSABI_AMDGPU_PAL; 1570e8d8bef9SDimitry Andric case Triple::Mesa3D: 1571e8d8bef9SDimitry Andric return ELF::ELFOSABI_AMDGPU_MESA3D; 1572e8d8bef9SDimitry Andric default: 1573e8d8bef9SDimitry Andric return ELF::ELFOSABI_NONE; 1574e8d8bef9SDimitry Andric } 1575e8d8bef9SDimitry Andric } 1576e8d8bef9SDimitry Andric 15770b57cec5SDimitry Andric BitcodeFile::BitcodeFile(MemoryBufferRef mb, StringRef archiveName, 15780eae32dcSDimitry Andric uint64_t offsetInArchive, bool lazy) 15790b57cec5SDimitry Andric : InputFile(BitcodeKind, mb) { 15800eae32dcSDimitry Andric this->archiveName = archiveName; 15810eae32dcSDimitry Andric this->lazy = lazy; 15820b57cec5SDimitry Andric 15830b57cec5SDimitry Andric std::string path = mb.getBufferIdentifier().str(); 15840b57cec5SDimitry Andric if (config->thinLTOIndexOnly) 15850b57cec5SDimitry Andric path = replaceThinLTOSuffix(mb.getBufferIdentifier()); 15860b57cec5SDimitry Andric 15870b57cec5SDimitry Andric // ThinLTO assumes that all MemoryBufferRefs given to it have a unique 15880b57cec5SDimitry Andric // name. If two archives define two members with the same name, this 15890b57cec5SDimitry Andric // causes a collision which result in only one of the objects being taken 15900b57cec5SDimitry Andric // into consideration at LTO time (which very likely causes undefined 15910b57cec5SDimitry Andric // symbols later in the link stage). So we append file offset to make 15920b57cec5SDimitry Andric // filename unique. 159304eeddc0SDimitry Andric StringRef name = archiveName.empty() 159404eeddc0SDimitry Andric ? saver().save(path) 159504eeddc0SDimitry Andric : saver().save(archiveName + "(" + path::filename(path) + 159604eeddc0SDimitry Andric " at " + utostr(offsetInArchive) + ")"); 15970b57cec5SDimitry Andric MemoryBufferRef mbref(mb.getBuffer(), name); 15980b57cec5SDimitry Andric 15990b57cec5SDimitry Andric obj = CHECK(lto::InputFile::create(mbref), this); 16000b57cec5SDimitry Andric 16010b57cec5SDimitry Andric Triple t(obj->getTargetTriple()); 16020b57cec5SDimitry Andric ekind = getBitcodeELFKind(t); 16030b57cec5SDimitry Andric emachine = getBitcodeMachineKind(mb.getBufferIdentifier(), t); 1604e8d8bef9SDimitry Andric osabi = getOsAbi(t); 16050b57cec5SDimitry Andric } 16060b57cec5SDimitry Andric 16070b57cec5SDimitry Andric static uint8_t mapVisibility(GlobalValue::VisibilityTypes gvVisibility) { 16080b57cec5SDimitry Andric switch (gvVisibility) { 16090b57cec5SDimitry Andric case GlobalValue::DefaultVisibility: 16100b57cec5SDimitry Andric return STV_DEFAULT; 16110b57cec5SDimitry Andric case GlobalValue::HiddenVisibility: 16120b57cec5SDimitry Andric return STV_HIDDEN; 16130b57cec5SDimitry Andric case GlobalValue::ProtectedVisibility: 16140b57cec5SDimitry Andric return STV_PROTECTED; 16150b57cec5SDimitry Andric } 16160b57cec5SDimitry Andric llvm_unreachable("unknown visibility"); 16170b57cec5SDimitry Andric } 16180b57cec5SDimitry Andric 161904eeddc0SDimitry Andric static void 162004eeddc0SDimitry Andric createBitcodeSymbol(Symbol *&sym, const std::vector<bool> &keptComdats, 162104eeddc0SDimitry Andric const lto::InputFile::Symbol &objSym, BitcodeFile &f) { 16220b57cec5SDimitry Andric uint8_t binding = objSym.isWeak() ? STB_WEAK : STB_GLOBAL; 16230b57cec5SDimitry Andric uint8_t type = objSym.isTLS() ? STT_TLS : STT_NOTYPE; 16240b57cec5SDimitry Andric uint8_t visibility = mapVisibility(objSym.getVisibility()); 16250b57cec5SDimitry Andric 162681ad6265SDimitry Andric if (!sym) 1627*bdd1243dSDimitry Andric sym = symtab.insert(saver().save(objSym.getName())); 162804eeddc0SDimitry Andric 16290b57cec5SDimitry Andric int c = objSym.getComdatIndex(); 16300b57cec5SDimitry Andric if (objSym.isUndefined() || (c != -1 && !keptComdats[c])) { 163181ad6265SDimitry Andric Undefined newSym(&f, StringRef(), binding, visibility, type); 163204eeddc0SDimitry Andric sym->resolve(newSym); 163304eeddc0SDimitry Andric sym->referenced = true; 163404eeddc0SDimitry Andric return; 16350b57cec5SDimitry Andric } 16360b57cec5SDimitry Andric 163704eeddc0SDimitry Andric if (objSym.isCommon()) { 163881ad6265SDimitry Andric sym->resolve(CommonSymbol{&f, StringRef(), binding, visibility, STT_OBJECT, 163904eeddc0SDimitry Andric objSym.getCommonAlignment(), 164004eeddc0SDimitry Andric objSym.getCommonSize()}); 164104eeddc0SDimitry Andric } else { 164281ad6265SDimitry Andric Defined newSym(&f, StringRef(), binding, visibility, type, 0, 0, nullptr); 164381ad6265SDimitry Andric if (objSym.canBeOmittedFromSymbolTable()) 164485868e8aSDimitry Andric newSym.exportDynamic = false; 164504eeddc0SDimitry Andric sym->resolve(newSym); 164604eeddc0SDimitry Andric } 16470b57cec5SDimitry Andric } 16480b57cec5SDimitry Andric 1649*bdd1243dSDimitry Andric void BitcodeFile::parse() { 1650fe6060f1SDimitry Andric for (std::pair<StringRef, Comdat::SelectionKind> s : obj->getComdatTable()) { 16510b57cec5SDimitry Andric keptComdats.push_back( 1652fe6060f1SDimitry Andric s.second == Comdat::NoDeduplicate || 1653*bdd1243dSDimitry Andric symtab.comdatGroups.try_emplace(CachedHashStringRef(s.first), this) 1654fe6060f1SDimitry Andric .second); 1655fe6060f1SDimitry Andric } 16560b57cec5SDimitry Andric 1657*bdd1243dSDimitry Andric if (numSymbols == 0) { 1658*bdd1243dSDimitry Andric numSymbols = obj->symbols().size(); 1659*bdd1243dSDimitry Andric symbols = std::make_unique<Symbol *[]>(numSymbols); 1660*bdd1243dSDimitry Andric } 166181ad6265SDimitry Andric // Process defined symbols first. See the comment in 166281ad6265SDimitry Andric // ObjFile<ELFT>::initializeSymbols. 1663*bdd1243dSDimitry Andric for (auto [i, irSym] : llvm::enumerate(obj->symbols())) 1664*bdd1243dSDimitry Andric if (!irSym.isUndefined()) 1665*bdd1243dSDimitry Andric createBitcodeSymbol(symbols[i], keptComdats, irSym, *this); 1666*bdd1243dSDimitry Andric for (auto [i, irSym] : llvm::enumerate(obj->symbols())) 1667*bdd1243dSDimitry Andric if (irSym.isUndefined()) 1668*bdd1243dSDimitry Andric createBitcodeSymbol(symbols[i], keptComdats, irSym, *this); 16690b57cec5SDimitry Andric 16700b57cec5SDimitry Andric for (auto l : obj->getDependentLibraries()) 16710b57cec5SDimitry Andric addDependentLibrary(l, this); 16720b57cec5SDimitry Andric } 16730b57cec5SDimitry Andric 16740eae32dcSDimitry Andric void BitcodeFile::parseLazy() { 1675*bdd1243dSDimitry Andric numSymbols = obj->symbols().size(); 1676*bdd1243dSDimitry Andric symbols = std::make_unique<Symbol *[]>(numSymbols); 1677*bdd1243dSDimitry Andric for (auto [i, irSym] : llvm::enumerate(obj->symbols())) 1678*bdd1243dSDimitry Andric if (!irSym.isUndefined()) { 1679*bdd1243dSDimitry Andric auto *sym = symtab.insert(saver().save(irSym.getName())); 168081ad6265SDimitry Andric sym->resolve(LazyObject{*this}); 1681*bdd1243dSDimitry Andric symbols[i] = sym; 168281ad6265SDimitry Andric } 168381ad6265SDimitry Andric } 168481ad6265SDimitry Andric 168581ad6265SDimitry Andric void BitcodeFile::postParse() { 1686*bdd1243dSDimitry Andric for (auto [i, irSym] : llvm::enumerate(obj->symbols())) { 1687*bdd1243dSDimitry Andric const Symbol &sym = *symbols[i]; 1688*bdd1243dSDimitry Andric if (sym.file == this || !sym.isDefined() || irSym.isUndefined() || 1689*bdd1243dSDimitry Andric irSym.isCommon() || irSym.isWeak()) 169081ad6265SDimitry Andric continue; 1691*bdd1243dSDimitry Andric int c = irSym.getComdatIndex(); 169281ad6265SDimitry Andric if (c != -1 && !keptComdats[c]) 169381ad6265SDimitry Andric continue; 169481ad6265SDimitry Andric reportDuplicate(sym, this, nullptr, 0); 169581ad6265SDimitry Andric } 16960eae32dcSDimitry Andric } 16970eae32dcSDimitry Andric 16980b57cec5SDimitry Andric void BinaryFile::parse() { 16990b57cec5SDimitry Andric ArrayRef<uint8_t> data = arrayRefFromStringRef(mb.getBuffer()); 17000b57cec5SDimitry Andric auto *section = make<InputSection>(this, SHF_ALLOC | SHF_WRITE, SHT_PROGBITS, 17010b57cec5SDimitry Andric 8, data, ".data"); 17020b57cec5SDimitry Andric sections.push_back(section); 17030b57cec5SDimitry Andric 17040b57cec5SDimitry Andric // For each input file foo that is embedded to a result as a binary 17050b57cec5SDimitry Andric // blob, we define _binary_foo_{start,end,size} symbols, so that 17060b57cec5SDimitry Andric // user programs can access blobs by name. Non-alphanumeric 17070b57cec5SDimitry Andric // characters in a filename are replaced with underscore. 17080b57cec5SDimitry Andric std::string s = "_binary_" + mb.getBufferIdentifier().str(); 17090b57cec5SDimitry Andric for (size_t i = 0; i < s.size(); ++i) 17100b57cec5SDimitry Andric if (!isAlnum(s[i])) 17110b57cec5SDimitry Andric s[i] = '_'; 17120b57cec5SDimitry Andric 171304eeddc0SDimitry Andric llvm::StringSaver &saver = lld::saver(); 171404eeddc0SDimitry Andric 1715*bdd1243dSDimitry Andric symtab.addAndCheckDuplicate(Defined{nullptr, saver.save(s + "_start"), 1716*bdd1243dSDimitry Andric STB_GLOBAL, STV_DEFAULT, STT_OBJECT, 0, 0, 1717*bdd1243dSDimitry Andric section}); 1718*bdd1243dSDimitry Andric symtab.addAndCheckDuplicate(Defined{nullptr, saver.save(s + "_end"), 171981ad6265SDimitry Andric STB_GLOBAL, STV_DEFAULT, STT_OBJECT, 172081ad6265SDimitry Andric data.size(), 0, section}); 1721*bdd1243dSDimitry Andric symtab.addAndCheckDuplicate(Defined{nullptr, saver.save(s + "_size"), 172281ad6265SDimitry Andric STB_GLOBAL, STV_DEFAULT, STT_OBJECT, 172381ad6265SDimitry Andric data.size(), 0, nullptr}); 17240b57cec5SDimitry Andric } 17250b57cec5SDimitry Andric 1726fcaf7f86SDimitry Andric ELFFileBase *elf::createObjFile(MemoryBufferRef mb, StringRef archiveName, 1727fcaf7f86SDimitry Andric bool lazy) { 1728fcaf7f86SDimitry Andric ELFFileBase *f; 17290b57cec5SDimitry Andric switch (getELFKind(mb, archiveName)) { 17300b57cec5SDimitry Andric case ELF32LEKind: 1731*bdd1243dSDimitry Andric f = make<ObjFile<ELF32LE>>(ELF32LEKind, mb, archiveName); 1732fcaf7f86SDimitry Andric break; 17330b57cec5SDimitry Andric case ELF32BEKind: 1734*bdd1243dSDimitry Andric f = make<ObjFile<ELF32BE>>(ELF32BEKind, mb, archiveName); 1735fcaf7f86SDimitry Andric break; 17360b57cec5SDimitry Andric case ELF64LEKind: 1737*bdd1243dSDimitry Andric f = make<ObjFile<ELF64LE>>(ELF64LEKind, mb, archiveName); 1738fcaf7f86SDimitry Andric break; 17390b57cec5SDimitry Andric case ELF64BEKind: 1740*bdd1243dSDimitry Andric f = make<ObjFile<ELF64BE>>(ELF64BEKind, mb, archiveName); 1741fcaf7f86SDimitry Andric break; 17420b57cec5SDimitry Andric default: 17430b57cec5SDimitry Andric llvm_unreachable("getELFKind"); 17440b57cec5SDimitry Andric } 1745*bdd1243dSDimitry Andric f->init(); 1746fcaf7f86SDimitry Andric f->lazy = lazy; 1747fcaf7f86SDimitry Andric return f; 17480b57cec5SDimitry Andric } 17490b57cec5SDimitry Andric 17500eae32dcSDimitry Andric template <class ELFT> void ObjFile<ELFT>::parseLazy() { 17510eae32dcSDimitry Andric const ArrayRef<typename ELFT::Sym> eSyms = this->getELFSyms<ELFT>(); 1752*bdd1243dSDimitry Andric numSymbols = eSyms.size(); 1753*bdd1243dSDimitry Andric symbols = std::make_unique<Symbol *[]>(numSymbols); 17540b57cec5SDimitry Andric 17550eae32dcSDimitry Andric // resolve() may trigger this->extract() if an existing symbol is an undefined 17560eae32dcSDimitry Andric // symbol. If that happens, this function has served its purpose, and we can 17570eae32dcSDimitry Andric // exit from the loop early. 1758*bdd1243dSDimitry Andric for (size_t i = firstGlobal, end = eSyms.size(); i != end; ++i) { 1759*bdd1243dSDimitry Andric if (eSyms[i].st_shndx == SHN_UNDEF) 1760*bdd1243dSDimitry Andric continue; 1761*bdd1243dSDimitry Andric symbols[i] = symtab.insert(CHECK(eSyms[i].getName(stringTable), this)); 1762*bdd1243dSDimitry Andric symbols[i]->resolve(LazyObject{*this}); 17630eae32dcSDimitry Andric if (!lazy) 1764*bdd1243dSDimitry Andric break; 17650b57cec5SDimitry Andric } 17660b57cec5SDimitry Andric } 17670b57cec5SDimitry Andric 17680eae32dcSDimitry Andric bool InputFile::shouldExtractForCommon(StringRef name) { 1769fcaf7f86SDimitry Andric if (isa<BitcodeFile>(this)) 1770e8d8bef9SDimitry Andric return isBitcodeNonCommonDef(mb, name, archiveName); 1771e8d8bef9SDimitry Andric 1772e8d8bef9SDimitry Andric return isNonCommonDef(mb, name, archiveName); 1773e8d8bef9SDimitry Andric } 1774e8d8bef9SDimitry Andric 17755ffd83dbSDimitry Andric std::string elf::replaceThinLTOSuffix(StringRef path) { 1776*bdd1243dSDimitry Andric auto [suffix, repl] = config->thinLTOObjectSuffixReplace; 17770b57cec5SDimitry Andric if (path.consume_back(suffix)) 17780b57cec5SDimitry Andric return (path + repl).str(); 17795ffd83dbSDimitry Andric return std::string(path); 17800b57cec5SDimitry Andric } 17810b57cec5SDimitry Andric 17825ffd83dbSDimitry Andric template class elf::ObjFile<ELF32LE>; 17835ffd83dbSDimitry Andric template class elf::ObjFile<ELF32BE>; 17845ffd83dbSDimitry Andric template class elf::ObjFile<ELF64LE>; 17855ffd83dbSDimitry Andric template class elf::ObjFile<ELF64BE>; 17860b57cec5SDimitry Andric 17870b57cec5SDimitry Andric template void SharedFile::parse<ELF32LE>(); 17880b57cec5SDimitry Andric template void SharedFile::parse<ELF32BE>(); 17890b57cec5SDimitry Andric template void SharedFile::parse<ELF64LE>(); 17900b57cec5SDimitry Andric template void SharedFile::parse<ELF64BE>(); 1791