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150
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1 //===- Driver.cpp ---------------------------------------------------------===//
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2 //
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3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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4 // See https://llvm.org/LICENSE.txt for license information.
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5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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6 //
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7 //===----------------------------------------------------------------------===//
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8 //
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9 // The driver drives the entire linking process. It is responsible for
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10 // parsing command line options and doing whatever it is instructed to do.
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11 //
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12 // One notable thing in the LLD's driver when compared to other linkers is
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13 // that the LLD's driver is agnostic on the host operating system.
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14 // Other linkers usually have implicit default values (such as a dynamic
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15 // linker path or library paths) for each host OS.
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16 //
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17 // I don't think implicit default values are useful because they are
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18 // usually explicitly specified by the compiler driver. They can even
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19 // be harmful when you are doing cross-linking. Therefore, in LLD, we
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20 // simply trust the compiler driver to pass all required options and
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21 // don't try to make effort on our side.
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22 //
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23 //===----------------------------------------------------------------------===//
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24
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25 #include "Driver.h"
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26 #include "Config.h"
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27 #include "ICF.h"
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28 #include "InputFiles.h"
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29 #include "InputSection.h"
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30 #include "LinkerScript.h"
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31 #include "MarkLive.h"
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32 #include "OutputSections.h"
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33 #include "ScriptParser.h"
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34 #include "SymbolTable.h"
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35 #include "Symbols.h"
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36 #include "SyntheticSections.h"
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37 #include "Target.h"
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38 #include "Writer.h"
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39 #include "lld/Common/Args.h"
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40 #include "lld/Common/Driver.h"
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41 #include "lld/Common/ErrorHandler.h"
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42 #include "lld/Common/Filesystem.h"
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43 #include "lld/Common/Memory.h"
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44 #include "lld/Common/Strings.h"
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45 #include "lld/Common/TargetOptionsCommandFlags.h"
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46 #include "lld/Common/Version.h"
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47 #include "llvm/ADT/SetVector.h"
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48 #include "llvm/ADT/StringExtras.h"
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49 #include "llvm/ADT/StringSwitch.h"
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50 #include "llvm/LTO/LTO.h"
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51 #include "llvm/Support/CommandLine.h"
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52 #include "llvm/Support/Compression.h"
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53 #include "llvm/Support/GlobPattern.h"
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54 #include "llvm/Support/LEB128.h"
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173
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55 #include "llvm/Support/Parallel.h"
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150
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56 #include "llvm/Support/Path.h"
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57 #include "llvm/Support/TarWriter.h"
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58 #include "llvm/Support/TargetSelect.h"
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59 #include "llvm/Support/TimeProfiler.h"
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60 #include "llvm/Support/raw_ostream.h"
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61 #include <cstdlib>
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62 #include <utility>
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63
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64 using namespace llvm;
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65 using namespace llvm::ELF;
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66 using namespace llvm::object;
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67 using namespace llvm::sys;
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68 using namespace llvm::support;
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173
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69 using namespace lld;
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70 using namespace lld::elf;
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150
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71
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173
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72 Configuration *elf::config;
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73 LinkerDriver *elf::driver;
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150
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74
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75 static void setConfigs(opt::InputArgList &args);
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76 static void readConfigs(opt::InputArgList &args);
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77
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173
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78 bool elf::link(ArrayRef<const char *> args, bool canExitEarly,
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79 raw_ostream &stdoutOS, raw_ostream &stderrOS) {
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150
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80 lld::stdoutOS = &stdoutOS;
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81 lld::stderrOS = &stderrOS;
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82
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83 errorHandler().logName = args::getFilenameWithoutExe(args[0]);
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84 errorHandler().errorLimitExceededMsg =
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85 "too many errors emitted, stopping now (use "
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86 "-error-limit=0 to see all errors)";
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87 errorHandler().exitEarly = canExitEarly;
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88 stderrOS.enable_colors(stderrOS.has_colors());
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89
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90 inputSections.clear();
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91 outputSections.clear();
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173
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92 archiveFiles.clear();
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150
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93 binaryFiles.clear();
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94 bitcodeFiles.clear();
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173
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95 lazyObjFiles.clear();
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150
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96 objectFiles.clear();
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97 sharedFiles.clear();
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173
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98 backwardReferences.clear();
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150
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99
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100 config = make<Configuration>();
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101 driver = make<LinkerDriver>();
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102 script = make<LinkerScript>();
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103 symtab = make<SymbolTable>();
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104
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105 tar = nullptr;
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106 memset(&in, 0, sizeof(in));
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107
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108 partitions = {Partition()};
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109
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110 SharedFile::vernauxNum = 0;
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111
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112 config->progName = args[0];
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113
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114 driver->main(args);
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115
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116 // Exit immediately if we don't need to return to the caller.
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117 // This saves time because the overhead of calling destructors
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118 // for all globally-allocated objects is not negligible.
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119 if (canExitEarly)
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120 exitLld(errorCount() ? 1 : 0);
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121
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122 freeArena();
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123 return !errorCount();
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124 }
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125
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126 // Parses a linker -m option.
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127 static std::tuple<ELFKind, uint16_t, uint8_t> parseEmulation(StringRef emul) {
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128 uint8_t osabi = 0;
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129 StringRef s = emul;
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130 if (s.endswith("_fbsd")) {
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131 s = s.drop_back(5);
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132 osabi = ELFOSABI_FREEBSD;
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133 }
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134
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135 std::pair<ELFKind, uint16_t> ret =
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136 StringSwitch<std::pair<ELFKind, uint16_t>>(s)
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137 .Cases("aarch64elf", "aarch64linux", "aarch64_elf64_le_vec",
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138 {ELF64LEKind, EM_AARCH64})
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139 .Cases("armelf", "armelf_linux_eabi", {ELF32LEKind, EM_ARM})
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140 .Case("elf32_x86_64", {ELF32LEKind, EM_X86_64})
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141 .Cases("elf32btsmip", "elf32btsmipn32", {ELF32BEKind, EM_MIPS})
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142 .Cases("elf32ltsmip", "elf32ltsmipn32", {ELF32LEKind, EM_MIPS})
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143 .Case("elf32lriscv", {ELF32LEKind, EM_RISCV})
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144 .Cases("elf32ppc", "elf32ppclinux", {ELF32BEKind, EM_PPC})
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145 .Case("elf64btsmip", {ELF64BEKind, EM_MIPS})
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146 .Case("elf64ltsmip", {ELF64LEKind, EM_MIPS})
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147 .Case("elf64lriscv", {ELF64LEKind, EM_RISCV})
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148 .Case("elf64ppc", {ELF64BEKind, EM_PPC64})
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149 .Case("elf64lppc", {ELF64LEKind, EM_PPC64})
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150 .Cases("elf_amd64", "elf_x86_64", {ELF64LEKind, EM_X86_64})
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151 .Case("elf_i386", {ELF32LEKind, EM_386})
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152 .Case("elf_iamcu", {ELF32LEKind, EM_IAMCU})
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173
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153 .Case("elf64_sparc", {ELF64BEKind, EM_SPARCV9})
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150
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154 .Default({ELFNoneKind, EM_NONE});
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155
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156 if (ret.first == ELFNoneKind)
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157 error("unknown emulation: " + emul);
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158 return std::make_tuple(ret.first, ret.second, osabi);
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159 }
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160
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161 // Returns slices of MB by parsing MB as an archive file.
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162 // Each slice consists of a member file in the archive.
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163 std::vector<std::pair<MemoryBufferRef, uint64_t>> static getArchiveMembers(
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164 MemoryBufferRef mb) {
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165 std::unique_ptr<Archive> file =
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166 CHECK(Archive::create(mb),
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167 mb.getBufferIdentifier() + ": failed to parse archive");
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168
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169 std::vector<std::pair<MemoryBufferRef, uint64_t>> v;
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170 Error err = Error::success();
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171 bool addToTar = file->isThin() && tar;
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172 for (const Archive::Child &c : file->children(err)) {
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173 MemoryBufferRef mbref =
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174 CHECK(c.getMemoryBufferRef(),
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175 mb.getBufferIdentifier() +
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176 ": could not get the buffer for a child of the archive");
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177 if (addToTar)
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178 tar->append(relativeToRoot(check(c.getFullName())), mbref.getBuffer());
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179 v.push_back(std::make_pair(mbref, c.getChildOffset()));
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180 }
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181 if (err)
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182 fatal(mb.getBufferIdentifier() + ": Archive::children failed: " +
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183 toString(std::move(err)));
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184
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185 // Take ownership of memory buffers created for members of thin archives.
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186 for (std::unique_ptr<MemoryBuffer> &mb : file->takeThinBuffers())
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187 make<std::unique_ptr<MemoryBuffer>>(std::move(mb));
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188
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189 return v;
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190 }
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191
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192 // Opens a file and create a file object. Path has to be resolved already.
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193 void LinkerDriver::addFile(StringRef path, bool withLOption) {
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194 using namespace sys::fs;
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195
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196 Optional<MemoryBufferRef> buffer = readFile(path);
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197 if (!buffer.hasValue())
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198 return;
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199 MemoryBufferRef mbref = *buffer;
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200
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201 if (config->formatBinary) {
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202 files.push_back(make<BinaryFile>(mbref));
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203 return;
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204 }
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205
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206 switch (identify_magic(mbref.getBuffer())) {
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207 case file_magic::unknown:
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208 readLinkerScript(mbref);
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209 return;
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210 case file_magic::archive: {
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211 // Handle -whole-archive.
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212 if (inWholeArchive) {
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213 for (const auto &p : getArchiveMembers(mbref))
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214 files.push_back(createObjectFile(p.first, path, p.second));
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215 return;
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216 }
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217
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218 std::unique_ptr<Archive> file =
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219 CHECK(Archive::create(mbref), path + ": failed to parse archive");
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220
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221 // If an archive file has no symbol table, it is likely that a user
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222 // is attempting LTO and using a default ar command that doesn't
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223 // understand the LLVM bitcode file. It is a pretty common error, so
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224 // we'll handle it as if it had a symbol table.
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225 if (!file->isEmpty() && !file->hasSymbolTable()) {
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226 // Check if all members are bitcode files. If not, ignore, which is the
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227 // default action without the LTO hack described above.
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228 for (const std::pair<MemoryBufferRef, uint64_t> &p :
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229 getArchiveMembers(mbref))
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230 if (identify_magic(p.first.getBuffer()) != file_magic::bitcode) {
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231 error(path + ": archive has no index; run ranlib to add one");
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232 return;
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233 }
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234
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235 for (const std::pair<MemoryBufferRef, uint64_t> &p :
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236 getArchiveMembers(mbref))
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237 files.push_back(make<LazyObjFile>(p.first, path, p.second));
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238 return;
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239 }
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240
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241 // Handle the regular case.
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242 files.push_back(make<ArchiveFile>(std::move(file)));
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243 return;
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244 }
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245 case file_magic::elf_shared_object:
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246 if (config->isStatic || config->relocatable) {
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247 error("attempted static link of dynamic object " + path);
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248 return;
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249 }
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250
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251 // DSOs usually have DT_SONAME tags in their ELF headers, and the
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252 // sonames are used to identify DSOs. But if they are missing,
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253 // they are identified by filenames. We don't know whether the new
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254 // file has a DT_SONAME or not because we haven't parsed it yet.
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255 // Here, we set the default soname for the file because we might
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256 // need it later.
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257 //
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258 // If a file was specified by -lfoo, the directory part is not
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259 // significant, as a user did not specify it. This behavior is
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260 // compatible with GNU.
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261 files.push_back(
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262 make<SharedFile>(mbref, withLOption ? path::filename(path) : path));
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263 return;
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264 case file_magic::bitcode:
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265 case file_magic::elf_relocatable:
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266 if (inLib)
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267 files.push_back(make<LazyObjFile>(mbref, "", 0));
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268 else
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269 files.push_back(createObjectFile(mbref));
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270 break;
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271 default:
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272 error(path + ": unknown file type");
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273 }
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274 }
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275
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276 // Add a given library by searching it from input search paths.
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277 void LinkerDriver::addLibrary(StringRef name) {
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278 if (Optional<std::string> path = searchLibrary(name))
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279 addFile(*path, /*withLOption=*/true);
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280 else
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281 error("unable to find library -l" + name);
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282 }
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283
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284 // This function is called on startup. We need this for LTO since
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285 // LTO calls LLVM functions to compile bitcode files to native code.
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286 // Technically this can be delayed until we read bitcode files, but
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287 // we don't bother to do lazily because the initialization is fast.
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288 static void initLLVM() {
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289 InitializeAllTargets();
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290 InitializeAllTargetMCs();
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291 InitializeAllAsmPrinters();
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292 InitializeAllAsmParsers();
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293 }
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294
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295 // Some command line options or some combinations of them are not allowed.
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296 // This function checks for such errors.
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297 static void checkOptions() {
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298 // The MIPS ABI as of 2016 does not support the GNU-style symbol lookup
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299 // table which is a relatively new feature.
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300 if (config->emachine == EM_MIPS && config->gnuHash)
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301 error("the .gnu.hash section is not compatible with the MIPS target");
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302
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303 if (config->fixCortexA53Errata843419 && config->emachine != EM_AARCH64)
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304 error("--fix-cortex-a53-843419 is only supported on AArch64 targets");
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305
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306 if (config->fixCortexA8 && config->emachine != EM_ARM)
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307 error("--fix-cortex-a8 is only supported on ARM targets");
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308
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309 if (config->tocOptimize && config->emachine != EM_PPC64)
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310 error("--toc-optimize is only supported on the PowerPC64 target");
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311
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312 if (config->pie && config->shared)
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313 error("-shared and -pie may not be used together");
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314
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315 if (!config->shared && !config->filterList.empty())
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316 error("-F may not be used without -shared");
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317
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318 if (!config->shared && !config->auxiliaryList.empty())
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319 error("-f may not be used without -shared");
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320
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321 if (!config->relocatable && !config->defineCommon)
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322 error("-no-define-common not supported in non relocatable output");
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323
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324 if (config->strip == StripPolicy::All && config->emitRelocs)
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325 error("--strip-all and --emit-relocs may not be used together");
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326
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327 if (config->zText && config->zIfuncNoplt)
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328 error("-z text and -z ifunc-noplt may not be used together");
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329
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330 if (config->relocatable) {
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331 if (config->shared)
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332 error("-r and -shared may not be used together");
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333 if (config->gcSections)
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334 error("-r and --gc-sections may not be used together");
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335 if (config->gdbIndex)
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336 error("-r and --gdb-index may not be used together");
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337 if (config->icf != ICFLevel::None)
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338 error("-r and --icf may not be used together");
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339 if (config->pie)
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340 error("-r and -pie may not be used together");
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341 if (config->exportDynamic)
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342 error("-r and --export-dynamic may not be used together");
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343 }
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344
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345 if (config->executeOnly) {
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346 if (config->emachine != EM_AARCH64)
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347 error("-execute-only is only supported on AArch64 targets");
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348
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349 if (config->singleRoRx && !script->hasSectionsCommand)
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350 error("-execute-only and -no-rosegment cannot be used together");
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351 }
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352
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353 if (config->zRetpolineplt && config->zForceIbt)
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354 error("-z force-ibt may not be used with -z retpolineplt");
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355
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356 if (config->emachine != EM_AARCH64) {
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173
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357 if (config->zPacPlt)
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150
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358 error("-z pac-plt only supported on AArch64");
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173
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359 if (config->zForceBti)
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150
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360 error("-z force-bti only supported on AArch64");
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361 }
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362 }
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363
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364 static const char *getReproduceOption(opt::InputArgList &args) {
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365 if (auto *arg = args.getLastArg(OPT_reproduce))
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366 return arg->getValue();
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367 return getenv("LLD_REPRODUCE");
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368 }
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369
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370 static bool hasZOption(opt::InputArgList &args, StringRef key) {
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371 for (auto *arg : args.filtered(OPT_z))
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372 if (key == arg->getValue())
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373 return true;
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374 return false;
|
|
|
375 }
|
|
|
376
|
|
|
377 static bool getZFlag(opt::InputArgList &args, StringRef k1, StringRef k2,
|
|
|
378 bool Default) {
|
|
|
379 for (auto *arg : args.filtered_reverse(OPT_z)) {
|
|
|
380 if (k1 == arg->getValue())
|
|
|
381 return true;
|
|
|
382 if (k2 == arg->getValue())
|
|
|
383 return false;
|
|
|
384 }
|
|
|
385 return Default;
|
|
|
386 }
|
|
|
387
|
|
|
388 static SeparateSegmentKind getZSeparate(opt::InputArgList &args) {
|
|
|
389 for (auto *arg : args.filtered_reverse(OPT_z)) {
|
|
|
390 StringRef v = arg->getValue();
|
|
|
391 if (v == "noseparate-code")
|
|
|
392 return SeparateSegmentKind::None;
|
|
|
393 if (v == "separate-code")
|
|
|
394 return SeparateSegmentKind::Code;
|
|
|
395 if (v == "separate-loadable-segments")
|
|
|
396 return SeparateSegmentKind::Loadable;
|
|
|
397 }
|
|
|
398 return SeparateSegmentKind::None;
|
|
|
399 }
|
|
|
400
|
|
|
401 static GnuStackKind getZGnuStack(opt::InputArgList &args) {
|
|
|
402 for (auto *arg : args.filtered_reverse(OPT_z)) {
|
|
|
403 if (StringRef("execstack") == arg->getValue())
|
|
|
404 return GnuStackKind::Exec;
|
|
|
405 if (StringRef("noexecstack") == arg->getValue())
|
|
|
406 return GnuStackKind::NoExec;
|
|
|
407 if (StringRef("nognustack") == arg->getValue())
|
|
|
408 return GnuStackKind::None;
|
|
|
409 }
|
|
|
410
|
|
|
411 return GnuStackKind::NoExec;
|
|
|
412 }
|
|
|
413
|
|
|
414 static bool isKnownZFlag(StringRef s) {
|
|
|
415 return s == "combreloc" || s == "copyreloc" || s == "defs" ||
|
|
|
416 s == "execstack" || s == "force-bti" || s == "force-ibt" ||
|
|
|
417 s == "global" || s == "hazardplt" || s == "ifunc-noplt" ||
|
|
|
418 s == "initfirst" || s == "interpose" ||
|
|
|
419 s == "keep-text-section-prefix" || s == "lazy" || s == "muldefs" ||
|
|
|
420 s == "separate-code" || s == "separate-loadable-segments" ||
|
|
|
421 s == "nocombreloc" || s == "nocopyreloc" || s == "nodefaultlib" ||
|
|
|
422 s == "nodelete" || s == "nodlopen" || s == "noexecstack" ||
|
|
|
423 s == "nognustack" || s == "nokeep-text-section-prefix" ||
|
|
|
424 s == "norelro" || s == "noseparate-code" || s == "notext" ||
|
|
|
425 s == "now" || s == "origin" || s == "pac-plt" || s == "relro" ||
|
|
|
426 s == "retpolineplt" || s == "rodynamic" || s == "shstk" ||
|
|
|
427 s == "text" || s == "undefs" || s == "wxneeded" ||
|
|
|
428 s.startswith("common-page-size=") || s.startswith("max-page-size=") ||
|
|
|
429 s.startswith("stack-size=");
|
|
|
430 }
|
|
|
431
|
|
|
432 // Report an error for an unknown -z option.
|
|
|
433 static void checkZOptions(opt::InputArgList &args) {
|
|
|
434 for (auto *arg : args.filtered(OPT_z))
|
|
|
435 if (!isKnownZFlag(arg->getValue()))
|
|
|
436 error("unknown -z value: " + StringRef(arg->getValue()));
|
|
|
437 }
|
|
|
438
|
|
|
439 void LinkerDriver::main(ArrayRef<const char *> argsArr) {
|
|
|
440 ELFOptTable parser;
|
|
|
441 opt::InputArgList args = parser.parse(argsArr.slice(1));
|
|
|
442
|
|
|
443 // Interpret this flag early because error() depends on them.
|
|
|
444 errorHandler().errorLimit = args::getInteger(args, OPT_error_limit, 20);
|
|
|
445 checkZOptions(args);
|
|
|
446
|
|
|
447 // Handle -help
|
|
|
448 if (args.hasArg(OPT_help)) {
|
|
|
449 printHelp();
|
|
|
450 return;
|
|
|
451 }
|
|
|
452
|
|
|
453 // Handle -v or -version.
|
|
|
454 //
|
|
|
455 // A note about "compatible with GNU linkers" message: this is a hack for
|
|
|
456 // scripts generated by GNU Libtool 2.4.6 (released in February 2014 and
|
|
|
457 // still the newest version in March 2017) or earlier to recognize LLD as
|
|
|
458 // a GNU compatible linker. As long as an output for the -v option
|
|
|
459 // contains "GNU" or "with BFD", they recognize us as GNU-compatible.
|
|
|
460 //
|
|
|
461 // This is somewhat ugly hack, but in reality, we had no choice other
|
|
|
462 // than doing this. Considering the very long release cycle of Libtool,
|
|
|
463 // it is not easy to improve it to recognize LLD as a GNU compatible
|
|
|
464 // linker in a timely manner. Even if we can make it, there are still a
|
|
|
465 // lot of "configure" scripts out there that are generated by old version
|
|
|
466 // of Libtool. We cannot convince every software developer to migrate to
|
|
|
467 // the latest version and re-generate scripts. So we have this hack.
|
|
|
468 if (args.hasArg(OPT_v) || args.hasArg(OPT_version))
|
|
|
469 message(getLLDVersion() + " (compatible with GNU linkers)");
|
|
|
470
|
|
|
471 if (const char *path = getReproduceOption(args)) {
|
|
|
472 // Note that --reproduce is a debug option so you can ignore it
|
|
|
473 // if you are trying to understand the whole picture of the code.
|
|
|
474 Expected<std::unique_ptr<TarWriter>> errOrWriter =
|
|
|
475 TarWriter::create(path, path::stem(path));
|
|
|
476 if (errOrWriter) {
|
|
|
477 tar = std::move(*errOrWriter);
|
|
|
478 tar->append("response.txt", createResponseFile(args));
|
|
|
479 tar->append("version.txt", getLLDVersion() + "\n");
|
|
|
480 } else {
|
|
|
481 error("--reproduce: " + toString(errOrWriter.takeError()));
|
|
|
482 }
|
|
|
483 }
|
|
|
484
|
|
|
485 readConfigs(args);
|
|
|
486
|
|
|
487 // The behavior of -v or --version is a bit strange, but this is
|
|
|
488 // needed for compatibility with GNU linkers.
|
|
|
489 if (args.hasArg(OPT_v) && !args.hasArg(OPT_INPUT))
|
|
|
490 return;
|
|
|
491 if (args.hasArg(OPT_version))
|
|
|
492 return;
|
|
|
493
|
|
|
494 // Initialize time trace profiler.
|
|
|
495 if (config->timeTraceEnabled)
|
|
|
496 timeTraceProfilerInitialize(config->timeTraceGranularity, config->progName);
|
|
|
497
|
|
|
498 {
|
|
|
499 llvm::TimeTraceScope timeScope("ExecuteLinker");
|
|
|
500
|
|
|
501 initLLVM();
|
|
|
502 createFiles(args);
|
|
|
503 if (errorCount())
|
|
|
504 return;
|
|
|
505
|
|
|
506 inferMachineType();
|
|
|
507 setConfigs(args);
|
|
|
508 checkOptions();
|
|
|
509 if (errorCount())
|
|
|
510 return;
|
|
|
511
|
|
|
512 // The Target instance handles target-specific stuff, such as applying
|
|
|
513 // relocations or writing a PLT section. It also contains target-dependent
|
|
|
514 // values such as a default image base address.
|
|
|
515 target = getTarget();
|
|
|
516
|
|
|
517 switch (config->ekind) {
|
|
|
518 case ELF32LEKind:
|
|
|
519 link<ELF32LE>(args);
|
|
|
520 break;
|
|
|
521 case ELF32BEKind:
|
|
|
522 link<ELF32BE>(args);
|
|
|
523 break;
|
|
|
524 case ELF64LEKind:
|
|
|
525 link<ELF64LE>(args);
|
|
|
526 break;
|
|
|
527 case ELF64BEKind:
|
|
|
528 link<ELF64BE>(args);
|
|
|
529 break;
|
|
|
530 default:
|
|
|
531 llvm_unreachable("unknown Config->EKind");
|
|
|
532 }
|
|
|
533 }
|
|
|
534
|
|
|
535 if (config->timeTraceEnabled) {
|
|
173
|
536 if (auto E = timeTraceProfilerWrite(args.getLastArgValue(OPT_time_trace_file_eq).str(),
|
|
|
537 config->outputFile)) {
|
|
|
538 handleAllErrors(std::move(E), [&](const StringError &SE) {
|
|
|
539 error(SE.getMessage());
|
|
|
540 });
|
|
150
|
541 return;
|
|
|
542 }
|
|
173
|
543
|
|
150
|
544 timeTraceProfilerCleanup();
|
|
|
545 }
|
|
|
546 }
|
|
|
547
|
|
|
548 static std::string getRpath(opt::InputArgList &args) {
|
|
|
549 std::vector<StringRef> v = args::getStrings(args, OPT_rpath);
|
|
|
550 return llvm::join(v.begin(), v.end(), ":");
|
|
|
551 }
|
|
|
552
|
|
|
553 // Determines what we should do if there are remaining unresolved
|
|
|
554 // symbols after the name resolution.
|
|
|
555 static UnresolvedPolicy getUnresolvedSymbolPolicy(opt::InputArgList &args) {
|
|
|
556 UnresolvedPolicy errorOrWarn = args.hasFlag(OPT_error_unresolved_symbols,
|
|
|
557 OPT_warn_unresolved_symbols, true)
|
|
|
558 ? UnresolvedPolicy::ReportError
|
|
|
559 : UnresolvedPolicy::Warn;
|
|
|
560
|
|
|
561 // Process the last of -unresolved-symbols, -no-undefined or -z defs.
|
|
|
562 for (auto *arg : llvm::reverse(args)) {
|
|
|
563 switch (arg->getOption().getID()) {
|
|
|
564 case OPT_unresolved_symbols: {
|
|
|
565 StringRef s = arg->getValue();
|
|
|
566 if (s == "ignore-all" || s == "ignore-in-object-files")
|
|
|
567 return UnresolvedPolicy::Ignore;
|
|
|
568 if (s == "ignore-in-shared-libs" || s == "report-all")
|
|
|
569 return errorOrWarn;
|
|
|
570 error("unknown --unresolved-symbols value: " + s);
|
|
|
571 continue;
|
|
|
572 }
|
|
|
573 case OPT_no_undefined:
|
|
|
574 return errorOrWarn;
|
|
|
575 case OPT_z:
|
|
|
576 if (StringRef(arg->getValue()) == "defs")
|
|
|
577 return errorOrWarn;
|
|
|
578 if (StringRef(arg->getValue()) == "undefs")
|
|
|
579 return UnresolvedPolicy::Ignore;
|
|
|
580 continue;
|
|
|
581 }
|
|
|
582 }
|
|
|
583
|
|
|
584 // -shared implies -unresolved-symbols=ignore-all because missing
|
|
|
585 // symbols are likely to be resolved at runtime using other DSOs.
|
|
|
586 if (config->shared)
|
|
|
587 return UnresolvedPolicy::Ignore;
|
|
|
588 return errorOrWarn;
|
|
|
589 }
|
|
|
590
|
|
|
591 static Target2Policy getTarget2(opt::InputArgList &args) {
|
|
|
592 StringRef s = args.getLastArgValue(OPT_target2, "got-rel");
|
|
|
593 if (s == "rel")
|
|
|
594 return Target2Policy::Rel;
|
|
|
595 if (s == "abs")
|
|
|
596 return Target2Policy::Abs;
|
|
|
597 if (s == "got-rel")
|
|
|
598 return Target2Policy::GotRel;
|
|
|
599 error("unknown --target2 option: " + s);
|
|
|
600 return Target2Policy::GotRel;
|
|
|
601 }
|
|
|
602
|
|
|
603 static bool isOutputFormatBinary(opt::InputArgList &args) {
|
|
|
604 StringRef s = args.getLastArgValue(OPT_oformat, "elf");
|
|
|
605 if (s == "binary")
|
|
|
606 return true;
|
|
|
607 if (!s.startswith("elf"))
|
|
|
608 error("unknown --oformat value: " + s);
|
|
|
609 return false;
|
|
|
610 }
|
|
|
611
|
|
|
612 static DiscardPolicy getDiscard(opt::InputArgList &args) {
|
|
|
613 auto *arg =
|
|
|
614 args.getLastArg(OPT_discard_all, OPT_discard_locals, OPT_discard_none);
|
|
|
615 if (!arg)
|
|
|
616 return DiscardPolicy::Default;
|
|
|
617 if (arg->getOption().getID() == OPT_discard_all)
|
|
|
618 return DiscardPolicy::All;
|
|
|
619 if (arg->getOption().getID() == OPT_discard_locals)
|
|
|
620 return DiscardPolicy::Locals;
|
|
|
621 return DiscardPolicy::None;
|
|
|
622 }
|
|
|
623
|
|
|
624 static StringRef getDynamicLinker(opt::InputArgList &args) {
|
|
|
625 auto *arg = args.getLastArg(OPT_dynamic_linker, OPT_no_dynamic_linker);
|
|
|
626 if (!arg)
|
|
|
627 return "";
|
|
|
628 if (arg->getOption().getID() == OPT_no_dynamic_linker) {
|
|
|
629 // --no-dynamic-linker suppresses undefined weak symbols in .dynsym
|
|
|
630 config->noDynamicLinker = true;
|
|
|
631 return "";
|
|
|
632 }
|
|
|
633 return arg->getValue();
|
|
|
634 }
|
|
|
635
|
|
|
636 static ICFLevel getICF(opt::InputArgList &args) {
|
|
|
637 auto *arg = args.getLastArg(OPT_icf_none, OPT_icf_safe, OPT_icf_all);
|
|
|
638 if (!arg || arg->getOption().getID() == OPT_icf_none)
|
|
|
639 return ICFLevel::None;
|
|
|
640 if (arg->getOption().getID() == OPT_icf_safe)
|
|
|
641 return ICFLevel::Safe;
|
|
|
642 return ICFLevel::All;
|
|
|
643 }
|
|
|
644
|
|
|
645 static StripPolicy getStrip(opt::InputArgList &args) {
|
|
|
646 if (args.hasArg(OPT_relocatable))
|
|
|
647 return StripPolicy::None;
|
|
|
648
|
|
|
649 auto *arg = args.getLastArg(OPT_strip_all, OPT_strip_debug);
|
|
|
650 if (!arg)
|
|
|
651 return StripPolicy::None;
|
|
|
652 if (arg->getOption().getID() == OPT_strip_all)
|
|
|
653 return StripPolicy::All;
|
|
|
654 return StripPolicy::Debug;
|
|
|
655 }
|
|
|
656
|
|
|
657 static uint64_t parseSectionAddress(StringRef s, opt::InputArgList &args,
|
|
|
658 const opt::Arg &arg) {
|
|
|
659 uint64_t va = 0;
|
|
|
660 if (s.startswith("0x"))
|
|
|
661 s = s.drop_front(2);
|
|
|
662 if (!to_integer(s, va, 16))
|
|
|
663 error("invalid argument: " + arg.getAsString(args));
|
|
|
664 return va;
|
|
|
665 }
|
|
|
666
|
|
|
667 static StringMap<uint64_t> getSectionStartMap(opt::InputArgList &args) {
|
|
|
668 StringMap<uint64_t> ret;
|
|
|
669 for (auto *arg : args.filtered(OPT_section_start)) {
|
|
|
670 StringRef name;
|
|
|
671 StringRef addr;
|
|
|
672 std::tie(name, addr) = StringRef(arg->getValue()).split('=');
|
|
|
673 ret[name] = parseSectionAddress(addr, args, *arg);
|
|
|
674 }
|
|
|
675
|
|
|
676 if (auto *arg = args.getLastArg(OPT_Ttext))
|
|
|
677 ret[".text"] = parseSectionAddress(arg->getValue(), args, *arg);
|
|
|
678 if (auto *arg = args.getLastArg(OPT_Tdata))
|
|
|
679 ret[".data"] = parseSectionAddress(arg->getValue(), args, *arg);
|
|
|
680 if (auto *arg = args.getLastArg(OPT_Tbss))
|
|
|
681 ret[".bss"] = parseSectionAddress(arg->getValue(), args, *arg);
|
|
|
682 return ret;
|
|
|
683 }
|
|
|
684
|
|
|
685 static SortSectionPolicy getSortSection(opt::InputArgList &args) {
|
|
|
686 StringRef s = args.getLastArgValue(OPT_sort_section);
|
|
|
687 if (s == "alignment")
|
|
|
688 return SortSectionPolicy::Alignment;
|
|
|
689 if (s == "name")
|
|
|
690 return SortSectionPolicy::Name;
|
|
|
691 if (!s.empty())
|
|
|
692 error("unknown --sort-section rule: " + s);
|
|
|
693 return SortSectionPolicy::Default;
|
|
|
694 }
|
|
|
695
|
|
|
696 static OrphanHandlingPolicy getOrphanHandling(opt::InputArgList &args) {
|
|
|
697 StringRef s = args.getLastArgValue(OPT_orphan_handling, "place");
|
|
|
698 if (s == "warn")
|
|
|
699 return OrphanHandlingPolicy::Warn;
|
|
|
700 if (s == "error")
|
|
|
701 return OrphanHandlingPolicy::Error;
|
|
|
702 if (s != "place")
|
|
|
703 error("unknown --orphan-handling mode: " + s);
|
|
|
704 return OrphanHandlingPolicy::Place;
|
|
|
705 }
|
|
|
706
|
|
|
707 // Parse --build-id or --build-id=<style>. We handle "tree" as a
|
|
|
708 // synonym for "sha1" because all our hash functions including
|
|
|
709 // -build-id=sha1 are actually tree hashes for performance reasons.
|
|
|
710 static std::pair<BuildIdKind, std::vector<uint8_t>>
|
|
|
711 getBuildId(opt::InputArgList &args) {
|
|
|
712 auto *arg = args.getLastArg(OPT_build_id, OPT_build_id_eq);
|
|
|
713 if (!arg)
|
|
|
714 return {BuildIdKind::None, {}};
|
|
|
715
|
|
|
716 if (arg->getOption().getID() == OPT_build_id)
|
|
|
717 return {BuildIdKind::Fast, {}};
|
|
|
718
|
|
|
719 StringRef s = arg->getValue();
|
|
|
720 if (s == "fast")
|
|
|
721 return {BuildIdKind::Fast, {}};
|
|
|
722 if (s == "md5")
|
|
|
723 return {BuildIdKind::Md5, {}};
|
|
|
724 if (s == "sha1" || s == "tree")
|
|
|
725 return {BuildIdKind::Sha1, {}};
|
|
|
726 if (s == "uuid")
|
|
|
727 return {BuildIdKind::Uuid, {}};
|
|
|
728 if (s.startswith("0x"))
|
|
|
729 return {BuildIdKind::Hexstring, parseHex(s.substr(2))};
|
|
|
730
|
|
|
731 if (s != "none")
|
|
|
732 error("unknown --build-id style: " + s);
|
|
|
733 return {BuildIdKind::None, {}};
|
|
|
734 }
|
|
|
735
|
|
|
736 static std::pair<bool, bool> getPackDynRelocs(opt::InputArgList &args) {
|
|
|
737 StringRef s = args.getLastArgValue(OPT_pack_dyn_relocs, "none");
|
|
|
738 if (s == "android")
|
|
|
739 return {true, false};
|
|
|
740 if (s == "relr")
|
|
|
741 return {false, true};
|
|
|
742 if (s == "android+relr")
|
|
|
743 return {true, true};
|
|
|
744
|
|
|
745 if (s != "none")
|
|
|
746 error("unknown -pack-dyn-relocs format: " + s);
|
|
|
747 return {false, false};
|
|
|
748 }
|
|
|
749
|
|
|
750 static void readCallGraph(MemoryBufferRef mb) {
|
|
|
751 // Build a map from symbol name to section
|
|
|
752 DenseMap<StringRef, Symbol *> map;
|
|
|
753 for (InputFile *file : objectFiles)
|
|
|
754 for (Symbol *sym : file->getSymbols())
|
|
|
755 map[sym->getName()] = sym;
|
|
|
756
|
|
|
757 auto findSection = [&](StringRef name) -> InputSectionBase * {
|
|
|
758 Symbol *sym = map.lookup(name);
|
|
|
759 if (!sym) {
|
|
|
760 if (config->warnSymbolOrdering)
|
|
|
761 warn(mb.getBufferIdentifier() + ": no such symbol: " + name);
|
|
|
762 return nullptr;
|
|
|
763 }
|
|
|
764 maybeWarnUnorderableSymbol(sym);
|
|
|
765
|
|
|
766 if (Defined *dr = dyn_cast_or_null<Defined>(sym))
|
|
|
767 return dyn_cast_or_null<InputSectionBase>(dr->section);
|
|
|
768 return nullptr;
|
|
|
769 };
|
|
|
770
|
|
|
771 for (StringRef line : args::getLines(mb)) {
|
|
|
772 SmallVector<StringRef, 3> fields;
|
|
|
773 line.split(fields, ' ');
|
|
|
774 uint64_t count;
|
|
|
775
|
|
|
776 if (fields.size() != 3 || !to_integer(fields[2], count)) {
|
|
|
777 error(mb.getBufferIdentifier() + ": parse error");
|
|
|
778 return;
|
|
|
779 }
|
|
|
780
|
|
|
781 if (InputSectionBase *from = findSection(fields[0]))
|
|
|
782 if (InputSectionBase *to = findSection(fields[1]))
|
|
|
783 config->callGraphProfile[std::make_pair(from, to)] += count;
|
|
|
784 }
|
|
|
785 }
|
|
|
786
|
|
|
787 template <class ELFT> static void readCallGraphsFromObjectFiles() {
|
|
|
788 for (auto file : objectFiles) {
|
|
|
789 auto *obj = cast<ObjFile<ELFT>>(file);
|
|
|
790
|
|
|
791 for (const Elf_CGProfile_Impl<ELFT> &cgpe : obj->cgProfile) {
|
|
|
792 auto *fromSym = dyn_cast<Defined>(&obj->getSymbol(cgpe.cgp_from));
|
|
|
793 auto *toSym = dyn_cast<Defined>(&obj->getSymbol(cgpe.cgp_to));
|
|
|
794 if (!fromSym || !toSym)
|
|
|
795 continue;
|
|
|
796
|
|
|
797 auto *from = dyn_cast_or_null<InputSectionBase>(fromSym->section);
|
|
|
798 auto *to = dyn_cast_or_null<InputSectionBase>(toSym->section);
|
|
|
799 if (from && to)
|
|
|
800 config->callGraphProfile[{from, to}] += cgpe.cgp_weight;
|
|
|
801 }
|
|
|
802 }
|
|
|
803 }
|
|
|
804
|
|
|
805 static bool getCompressDebugSections(opt::InputArgList &args) {
|
|
|
806 StringRef s = args.getLastArgValue(OPT_compress_debug_sections, "none");
|
|
|
807 if (s == "none")
|
|
|
808 return false;
|
|
|
809 if (s != "zlib")
|
|
|
810 error("unknown --compress-debug-sections value: " + s);
|
|
|
811 if (!zlib::isAvailable())
|
|
|
812 error("--compress-debug-sections: zlib is not available");
|
|
|
813 return true;
|
|
|
814 }
|
|
|
815
|
|
|
816 static StringRef getAliasSpelling(opt::Arg *arg) {
|
|
|
817 if (const opt::Arg *alias = arg->getAlias())
|
|
|
818 return alias->getSpelling();
|
|
|
819 return arg->getSpelling();
|
|
|
820 }
|
|
|
821
|
|
|
822 static std::pair<StringRef, StringRef> getOldNewOptions(opt::InputArgList &args,
|
|
|
823 unsigned id) {
|
|
|
824 auto *arg = args.getLastArg(id);
|
|
|
825 if (!arg)
|
|
|
826 return {"", ""};
|
|
|
827
|
|
|
828 StringRef s = arg->getValue();
|
|
|
829 std::pair<StringRef, StringRef> ret = s.split(';');
|
|
|
830 if (ret.second.empty())
|
|
|
831 error(getAliasSpelling(arg) + " expects 'old;new' format, but got " + s);
|
|
|
832 return ret;
|
|
|
833 }
|
|
|
834
|
|
|
835 // Parse the symbol ordering file and warn for any duplicate entries.
|
|
|
836 static std::vector<StringRef> getSymbolOrderingFile(MemoryBufferRef mb) {
|
|
|
837 SetVector<StringRef> names;
|
|
|
838 for (StringRef s : args::getLines(mb))
|
|
|
839 if (!names.insert(s) && config->warnSymbolOrdering)
|
|
|
840 warn(mb.getBufferIdentifier() + ": duplicate ordered symbol: " + s);
|
|
|
841
|
|
|
842 return names.takeVector();
|
|
|
843 }
|
|
|
844
|
|
|
845 static void parseClangOption(StringRef opt, const Twine &msg) {
|
|
|
846 std::string err;
|
|
|
847 raw_string_ostream os(err);
|
|
|
848
|
|
|
849 const char *argv[] = {config->progName.data(), opt.data()};
|
|
|
850 if (cl::ParseCommandLineOptions(2, argv, "", &os))
|
|
|
851 return;
|
|
|
852 os.flush();
|
|
|
853 error(msg + ": " + StringRef(err).trim());
|
|
|
854 }
|
|
|
855
|
|
|
856 // Initializes Config members by the command line options.
|
|
|
857 static void readConfigs(opt::InputArgList &args) {
|
|
|
858 errorHandler().verbose = args.hasArg(OPT_verbose);
|
|
|
859 errorHandler().fatalWarnings =
|
|
|
860 args.hasFlag(OPT_fatal_warnings, OPT_no_fatal_warnings, false);
|
|
|
861 errorHandler().vsDiagnostics =
|
|
|
862 args.hasArg(OPT_visual_studio_diagnostics_format, false);
|
|
|
863
|
|
|
864 config->allowMultipleDefinition =
|
|
|
865 args.hasFlag(OPT_allow_multiple_definition,
|
|
|
866 OPT_no_allow_multiple_definition, false) ||
|
|
|
867 hasZOption(args, "muldefs");
|
|
|
868 config->allowShlibUndefined =
|
|
|
869 args.hasFlag(OPT_allow_shlib_undefined, OPT_no_allow_shlib_undefined,
|
|
|
870 args.hasArg(OPT_shared));
|
|
|
871 config->auxiliaryList = args::getStrings(args, OPT_auxiliary);
|
|
|
872 config->bsymbolic = args.hasArg(OPT_Bsymbolic);
|
|
|
873 config->bsymbolicFunctions = args.hasArg(OPT_Bsymbolic_functions);
|
|
|
874 config->checkSections =
|
|
|
875 args.hasFlag(OPT_check_sections, OPT_no_check_sections, true);
|
|
|
876 config->chroot = args.getLastArgValue(OPT_chroot);
|
|
|
877 config->compressDebugSections = getCompressDebugSections(args);
|
|
|
878 config->cref = args.hasFlag(OPT_cref, OPT_no_cref, false);
|
|
|
879 config->defineCommon = args.hasFlag(OPT_define_common, OPT_no_define_common,
|
|
|
880 !args.hasArg(OPT_relocatable));
|
|
173
|
881 config->optimizeBBJumps =
|
|
|
882 args.hasFlag(OPT_optimize_bb_jumps, OPT_no_optimize_bb_jumps, false);
|
|
150
|
883 config->demangle = args.hasFlag(OPT_demangle, OPT_no_demangle, true);
|
|
|
884 config->dependentLibraries = args.hasFlag(OPT_dependent_libraries, OPT_no_dependent_libraries, true);
|
|
|
885 config->disableVerify = args.hasArg(OPT_disable_verify);
|
|
|
886 config->discard = getDiscard(args);
|
|
|
887 config->dwoDir = args.getLastArgValue(OPT_plugin_opt_dwo_dir_eq);
|
|
|
888 config->dynamicLinker = getDynamicLinker(args);
|
|
|
889 config->ehFrameHdr =
|
|
|
890 args.hasFlag(OPT_eh_frame_hdr, OPT_no_eh_frame_hdr, false);
|
|
|
891 config->emitLLVM = args.hasArg(OPT_plugin_opt_emit_llvm, false);
|
|
|
892 config->emitRelocs = args.hasArg(OPT_emit_relocs);
|
|
|
893 config->callGraphProfileSort = args.hasFlag(
|
|
|
894 OPT_call_graph_profile_sort, OPT_no_call_graph_profile_sort, true);
|
|
|
895 config->enableNewDtags =
|
|
|
896 args.hasFlag(OPT_enable_new_dtags, OPT_disable_new_dtags, true);
|
|
|
897 config->entry = args.getLastArgValue(OPT_entry);
|
|
|
898 config->executeOnly =
|
|
|
899 args.hasFlag(OPT_execute_only, OPT_no_execute_only, false);
|
|
|
900 config->exportDynamic =
|
|
|
901 args.hasFlag(OPT_export_dynamic, OPT_no_export_dynamic, false);
|
|
|
902 config->filterList = args::getStrings(args, OPT_filter);
|
|
|
903 config->fini = args.getLastArgValue(OPT_fini, "_fini");
|
|
|
904 config->fixCortexA53Errata843419 = args.hasArg(OPT_fix_cortex_a53_843419) &&
|
|
|
905 !args.hasArg(OPT_relocatable);
|
|
|
906 config->fixCortexA8 =
|
|
|
907 args.hasArg(OPT_fix_cortex_a8) && !args.hasArg(OPT_relocatable);
|
|
|
908 config->gcSections = args.hasFlag(OPT_gc_sections, OPT_no_gc_sections, false);
|
|
|
909 config->gnuUnique = args.hasFlag(OPT_gnu_unique, OPT_no_gnu_unique, true);
|
|
|
910 config->gdbIndex = args.hasFlag(OPT_gdb_index, OPT_no_gdb_index, false);
|
|
|
911 config->icf = getICF(args);
|
|
|
912 config->ignoreDataAddressEquality =
|
|
|
913 args.hasArg(OPT_ignore_data_address_equality);
|
|
|
914 config->ignoreFunctionAddressEquality =
|
|
|
915 args.hasArg(OPT_ignore_function_address_equality);
|
|
|
916 config->init = args.getLastArgValue(OPT_init, "_init");
|
|
|
917 config->ltoAAPipeline = args.getLastArgValue(OPT_lto_aa_pipeline);
|
|
|
918 config->ltoCSProfileGenerate = args.hasArg(OPT_lto_cs_profile_generate);
|
|
|
919 config->ltoCSProfileFile = args.getLastArgValue(OPT_lto_cs_profile_file);
|
|
|
920 config->ltoDebugPassManager = args.hasArg(OPT_lto_debug_pass_manager);
|
|
173
|
921 config->ltoEmitAsm = args.hasArg(OPT_lto_emit_asm);
|
|
150
|
922 config->ltoNewPassManager = args.hasArg(OPT_lto_new_pass_manager);
|
|
|
923 config->ltoNewPmPasses = args.getLastArgValue(OPT_lto_newpm_passes);
|
|
|
924 config->ltoWholeProgramVisibility =
|
|
|
925 args.hasArg(OPT_lto_whole_program_visibility);
|
|
|
926 config->ltoo = args::getInteger(args, OPT_lto_O, 2);
|
|
|
927 config->ltoObjPath = args.getLastArgValue(OPT_lto_obj_path_eq);
|
|
|
928 config->ltoPartitions = args::getInteger(args, OPT_lto_partitions, 1);
|
|
|
929 config->ltoSampleProfile = args.getLastArgValue(OPT_lto_sample_profile);
|
|
173
|
930 config->ltoBasicBlockSections =
|
|
|
931 args.getLastArgValue(OPT_lto_basicblock_sections);
|
|
|
932 config->ltoUniqueBBSectionNames =
|
|
|
933 args.hasFlag(OPT_lto_unique_bb_section_names,
|
|
|
934 OPT_no_lto_unique_bb_section_names, false);
|
|
150
|
935 config->mapFile = args.getLastArgValue(OPT_Map);
|
|
|
936 config->mipsGotSize = args::getInteger(args, OPT_mips_got_size, 0xfff0);
|
|
|
937 config->mergeArmExidx =
|
|
|
938 args.hasFlag(OPT_merge_exidx_entries, OPT_no_merge_exidx_entries, true);
|
|
|
939 config->mmapOutputFile =
|
|
|
940 args.hasFlag(OPT_mmap_output_file, OPT_no_mmap_output_file, true);
|
|
|
941 config->nmagic = args.hasFlag(OPT_nmagic, OPT_no_nmagic, false);
|
|
|
942 config->noinhibitExec = args.hasArg(OPT_noinhibit_exec);
|
|
|
943 config->nostdlib = args.hasArg(OPT_nostdlib);
|
|
|
944 config->oFormatBinary = isOutputFormatBinary(args);
|
|
|
945 config->omagic = args.hasFlag(OPT_omagic, OPT_no_omagic, false);
|
|
|
946 config->optRemarksFilename = args.getLastArgValue(OPT_opt_remarks_filename);
|
|
|
947 config->optRemarksPasses = args.getLastArgValue(OPT_opt_remarks_passes);
|
|
|
948 config->optRemarksWithHotness = args.hasArg(OPT_opt_remarks_with_hotness);
|
|
|
949 config->optRemarksFormat = args.getLastArgValue(OPT_opt_remarks_format);
|
|
|
950 config->optimize = args::getInteger(args, OPT_O, 1);
|
|
|
951 config->orphanHandling = getOrphanHandling(args);
|
|
|
952 config->outputFile = args.getLastArgValue(OPT_o);
|
|
|
953 config->pie = args.hasFlag(OPT_pie, OPT_no_pie, false);
|
|
|
954 config->printIcfSections =
|
|
|
955 args.hasFlag(OPT_print_icf_sections, OPT_no_print_icf_sections, false);
|
|
|
956 config->printGcSections =
|
|
|
957 args.hasFlag(OPT_print_gc_sections, OPT_no_print_gc_sections, false);
|
|
173
|
958 config->printArchiveStats = args.getLastArgValue(OPT_print_archive_stats);
|
|
150
|
959 config->printSymbolOrder =
|
|
|
960 args.getLastArgValue(OPT_print_symbol_order);
|
|
|
961 config->rpath = getRpath(args);
|
|
|
962 config->relocatable = args.hasArg(OPT_relocatable);
|
|
|
963 config->saveTemps = args.hasArg(OPT_save_temps);
|
|
173
|
964 if (args.hasArg(OPT_shuffle_sections))
|
|
|
965 config->shuffleSectionSeed = args::getInteger(args, OPT_shuffle_sections, 0);
|
|
150
|
966 config->searchPaths = args::getStrings(args, OPT_library_path);
|
|
|
967 config->sectionStartMap = getSectionStartMap(args);
|
|
|
968 config->shared = args.hasArg(OPT_shared);
|
|
173
|
969 config->singleRoRx = !args.hasFlag(OPT_rosegment, OPT_no_rosegment, true);
|
|
150
|
970 config->soName = args.getLastArgValue(OPT_soname);
|
|
|
971 config->sortSection = getSortSection(args);
|
|
|
972 config->splitStackAdjustSize = args::getInteger(args, OPT_split_stack_adjust_size, 16384);
|
|
|
973 config->strip = getStrip(args);
|
|
|
974 config->sysroot = args.getLastArgValue(OPT_sysroot);
|
|
|
975 config->target1Rel = args.hasFlag(OPT_target1_rel, OPT_target1_abs, false);
|
|
|
976 config->target2 = getTarget2(args);
|
|
|
977 config->thinLTOCacheDir = args.getLastArgValue(OPT_thinlto_cache_dir);
|
|
|
978 config->thinLTOCachePolicy = CHECK(
|
|
|
979 parseCachePruningPolicy(args.getLastArgValue(OPT_thinlto_cache_policy)),
|
|
|
980 "--thinlto-cache-policy: invalid cache policy");
|
|
|
981 config->thinLTOEmitImportsFiles = args.hasArg(OPT_thinlto_emit_imports_files);
|
|
|
982 config->thinLTOIndexOnly = args.hasArg(OPT_thinlto_index_only) ||
|
|
|
983 args.hasArg(OPT_thinlto_index_only_eq);
|
|
|
984 config->thinLTOIndexOnlyArg = args.getLastArgValue(OPT_thinlto_index_only_eq);
|
|
|
985 config->thinLTOObjectSuffixReplace =
|
|
|
986 getOldNewOptions(args, OPT_thinlto_object_suffix_replace_eq);
|
|
|
987 config->thinLTOPrefixReplace =
|
|
|
988 getOldNewOptions(args, OPT_thinlto_prefix_replace_eq);
|
|
|
989 config->timeTraceEnabled = args.hasArg(OPT_time_trace);
|
|
|
990 config->timeTraceGranularity =
|
|
|
991 args::getInteger(args, OPT_time_trace_granularity, 500);
|
|
|
992 config->trace = args.hasArg(OPT_trace);
|
|
|
993 config->undefined = args::getStrings(args, OPT_undefined);
|
|
|
994 config->undefinedVersion =
|
|
|
995 args.hasFlag(OPT_undefined_version, OPT_no_undefined_version, true);
|
|
173
|
996 config->unique = args.hasArg(OPT_unique);
|
|
150
|
997 config->useAndroidRelrTags = args.hasFlag(
|
|
|
998 OPT_use_android_relr_tags, OPT_no_use_android_relr_tags, false);
|
|
|
999 config->unresolvedSymbols = getUnresolvedSymbolPolicy(args);
|
|
|
1000 config->warnBackrefs =
|
|
|
1001 args.hasFlag(OPT_warn_backrefs, OPT_no_warn_backrefs, false);
|
|
|
1002 config->warnCommon = args.hasFlag(OPT_warn_common, OPT_no_warn_common, false);
|
|
|
1003 config->warnIfuncTextrel =
|
|
|
1004 args.hasFlag(OPT_warn_ifunc_textrel, OPT_no_warn_ifunc_textrel, false);
|
|
|
1005 config->warnSymbolOrdering =
|
|
|
1006 args.hasFlag(OPT_warn_symbol_ordering, OPT_no_warn_symbol_ordering, true);
|
|
|
1007 config->zCombreloc = getZFlag(args, "combreloc", "nocombreloc", true);
|
|
|
1008 config->zCopyreloc = getZFlag(args, "copyreloc", "nocopyreloc", true);
|
|
173
|
1009 config->zForceBti = hasZOption(args, "force-bti");
|
|
150
|
1010 config->zForceIbt = hasZOption(args, "force-ibt");
|
|
|
1011 config->zGlobal = hasZOption(args, "global");
|
|
|
1012 config->zGnustack = getZGnuStack(args);
|
|
|
1013 config->zHazardplt = hasZOption(args, "hazardplt");
|
|
|
1014 config->zIfuncNoplt = hasZOption(args, "ifunc-noplt");
|
|
|
1015 config->zInitfirst = hasZOption(args, "initfirst");
|
|
|
1016 config->zInterpose = hasZOption(args, "interpose");
|
|
|
1017 config->zKeepTextSectionPrefix = getZFlag(
|
|
|
1018 args, "keep-text-section-prefix", "nokeep-text-section-prefix", false);
|
|
|
1019 config->zNodefaultlib = hasZOption(args, "nodefaultlib");
|
|
|
1020 config->zNodelete = hasZOption(args, "nodelete");
|
|
|
1021 config->zNodlopen = hasZOption(args, "nodlopen");
|
|
|
1022 config->zNow = getZFlag(args, "now", "lazy", false);
|
|
|
1023 config->zOrigin = hasZOption(args, "origin");
|
|
173
|
1024 config->zPacPlt = hasZOption(args, "pac-plt");
|
|
150
|
1025 config->zRelro = getZFlag(args, "relro", "norelro", true);
|
|
|
1026 config->zRetpolineplt = hasZOption(args, "retpolineplt");
|
|
|
1027 config->zRodynamic = hasZOption(args, "rodynamic");
|
|
|
1028 config->zSeparate = getZSeparate(args);
|
|
|
1029 config->zShstk = hasZOption(args, "shstk");
|
|
|
1030 config->zStackSize = args::getZOptionValue(args, OPT_z, "stack-size", 0);
|
|
|
1031 config->zText = getZFlag(args, "text", "notext", true);
|
|
|
1032 config->zWxneeded = hasZOption(args, "wxneeded");
|
|
|
1033
|
|
|
1034 // Parse LTO options.
|
|
|
1035 if (auto *arg = args.getLastArg(OPT_plugin_opt_mcpu_eq))
|
|
|
1036 parseClangOption(saver.save("-mcpu=" + StringRef(arg->getValue())),
|
|
|
1037 arg->getSpelling());
|
|
|
1038
|
|
173
|
1039 for (opt::Arg *arg : args.filtered(OPT_plugin_opt_eq_minus))
|
|
|
1040 parseClangOption(std::string("-") + arg->getValue(), arg->getSpelling());
|
|
|
1041
|
|
|
1042 // GCC collect2 passes -plugin-opt=path/to/lto-wrapper with an absolute or
|
|
|
1043 // relative path. Just ignore. If not ended with "lto-wrapper", consider it an
|
|
|
1044 // unsupported LLVMgold.so option and error.
|
|
|
1045 for (opt::Arg *arg : args.filtered(OPT_plugin_opt_eq))
|
|
|
1046 if (!StringRef(arg->getValue()).endswith("lto-wrapper"))
|
|
|
1047 error(arg->getSpelling() + ": unknown plugin option '" + arg->getValue() +
|
|
|
1048 "'");
|
|
150
|
1049
|
|
|
1050 // Parse -mllvm options.
|
|
|
1051 for (auto *arg : args.filtered(OPT_mllvm))
|
|
|
1052 parseClangOption(arg->getValue(), arg->getSpelling());
|
|
|
1053
|
|
173
|
1054 // --threads= takes a positive integer and provides the default value for
|
|
|
1055 // --thinlto-jobs=.
|
|
|
1056 if (auto *arg = args.getLastArg(OPT_threads)) {
|
|
|
1057 StringRef v(arg->getValue());
|
|
|
1058 unsigned threads = 0;
|
|
|
1059 if (!llvm::to_integer(v, threads, 0) || threads == 0)
|
|
|
1060 error(arg->getSpelling() + ": expected a positive integer, but got '" +
|
|
|
1061 arg->getValue() + "'");
|
|
|
1062 parallel::strategy = hardware_concurrency(threads);
|
|
|
1063 config->thinLTOJobs = v;
|
|
|
1064 }
|
|
|
1065 if (auto *arg = args.getLastArg(OPT_thinlto_jobs))
|
|
|
1066 config->thinLTOJobs = arg->getValue();
|
|
|
1067
|
|
150
|
1068 if (config->ltoo > 3)
|
|
|
1069 error("invalid optimization level for LTO: " + Twine(config->ltoo));
|
|
|
1070 if (config->ltoPartitions == 0)
|
|
|
1071 error("--lto-partitions: number of threads must be > 0");
|
|
173
|
1072 if (!get_threadpool_strategy(config->thinLTOJobs))
|
|
|
1073 error("--thinlto-jobs: invalid job count: " + config->thinLTOJobs);
|
|
150
|
1074
|
|
|
1075 if (config->splitStackAdjustSize < 0)
|
|
|
1076 error("--split-stack-adjust-size: size must be >= 0");
|
|
|
1077
|
|
|
1078 // The text segment is traditionally the first segment, whose address equals
|
|
|
1079 // the base address. However, lld places the R PT_LOAD first. -Ttext-segment
|
|
|
1080 // is an old-fashioned option that does not play well with lld's layout.
|
|
|
1081 // Suggest --image-base as a likely alternative.
|
|
|
1082 if (args.hasArg(OPT_Ttext_segment))
|
|
|
1083 error("-Ttext-segment is not supported. Use --image-base if you "
|
|
|
1084 "intend to set the base address");
|
|
|
1085
|
|
|
1086 // Parse ELF{32,64}{LE,BE} and CPU type.
|
|
|
1087 if (auto *arg = args.getLastArg(OPT_m)) {
|
|
|
1088 StringRef s = arg->getValue();
|
|
|
1089 std::tie(config->ekind, config->emachine, config->osabi) =
|
|
|
1090 parseEmulation(s);
|
|
|
1091 config->mipsN32Abi =
|
|
|
1092 (s.startswith("elf32btsmipn32") || s.startswith("elf32ltsmipn32"));
|
|
|
1093 config->emulation = s;
|
|
|
1094 }
|
|
|
1095
|
|
|
1096 // Parse -hash-style={sysv,gnu,both}.
|
|
|
1097 if (auto *arg = args.getLastArg(OPT_hash_style)) {
|
|
|
1098 StringRef s = arg->getValue();
|
|
|
1099 if (s == "sysv")
|
|
|
1100 config->sysvHash = true;
|
|
|
1101 else if (s == "gnu")
|
|
|
1102 config->gnuHash = true;
|
|
|
1103 else if (s == "both")
|
|
|
1104 config->sysvHash = config->gnuHash = true;
|
|
|
1105 else
|
|
|
1106 error("unknown -hash-style: " + s);
|
|
|
1107 }
|
|
|
1108
|
|
|
1109 if (args.hasArg(OPT_print_map))
|
|
|
1110 config->mapFile = "-";
|
|
|
1111
|
|
|
1112 // Page alignment can be disabled by the -n (--nmagic) and -N (--omagic).
|
|
|
1113 // As PT_GNU_RELRO relies on Paging, do not create it when we have disabled
|
|
|
1114 // it.
|
|
|
1115 if (config->nmagic || config->omagic)
|
|
|
1116 config->zRelro = false;
|
|
|
1117
|
|
|
1118 std::tie(config->buildId, config->buildIdVector) = getBuildId(args);
|
|
|
1119
|
|
|
1120 std::tie(config->androidPackDynRelocs, config->relrPackDynRelocs) =
|
|
|
1121 getPackDynRelocs(args);
|
|
|
1122
|
|
|
1123 if (auto *arg = args.getLastArg(OPT_symbol_ordering_file)){
|
|
|
1124 if (args.hasArg(OPT_call_graph_ordering_file))
|
|
|
1125 error("--symbol-ordering-file and --call-graph-order-file "
|
|
|
1126 "may not be used together");
|
|
|
1127 if (Optional<MemoryBufferRef> buffer = readFile(arg->getValue())){
|
|
|
1128 config->symbolOrderingFile = getSymbolOrderingFile(*buffer);
|
|
|
1129 // Also need to disable CallGraphProfileSort to prevent
|
|
|
1130 // LLD order symbols with CGProfile
|
|
|
1131 config->callGraphProfileSort = false;
|
|
|
1132 }
|
|
|
1133 }
|
|
|
1134
|
|
|
1135 assert(config->versionDefinitions.empty());
|
|
|
1136 config->versionDefinitions.push_back({"local", (uint16_t)VER_NDX_LOCAL, {}});
|
|
|
1137 config->versionDefinitions.push_back(
|
|
|
1138 {"global", (uint16_t)VER_NDX_GLOBAL, {}});
|
|
|
1139
|
|
|
1140 // If --retain-symbol-file is used, we'll keep only the symbols listed in
|
|
|
1141 // the file and discard all others.
|
|
|
1142 if (auto *arg = args.getLastArg(OPT_retain_symbols_file)) {
|
|
|
1143 config->versionDefinitions[VER_NDX_LOCAL].patterns.push_back(
|
|
|
1144 {"*", /*isExternCpp=*/false, /*hasWildcard=*/true});
|
|
|
1145 if (Optional<MemoryBufferRef> buffer = readFile(arg->getValue()))
|
|
|
1146 for (StringRef s : args::getLines(*buffer))
|
|
|
1147 config->versionDefinitions[VER_NDX_GLOBAL].patterns.push_back(
|
|
|
1148 {s, /*isExternCpp=*/false, /*hasWildcard=*/false});
|
|
|
1149 }
|
|
|
1150
|
|
173
|
1151 for (opt::Arg *arg : args.filtered(OPT_warn_backrefs_exclude)) {
|
|
|
1152 StringRef pattern(arg->getValue());
|
|
|
1153 if (Expected<GlobPattern> pat = GlobPattern::create(pattern))
|
|
|
1154 config->warnBackrefsExclude.push_back(std::move(*pat));
|
|
|
1155 else
|
|
|
1156 error(arg->getSpelling() + ": " + toString(pat.takeError()));
|
|
|
1157 }
|
|
|
1158
|
|
150
|
1159 // Parses -dynamic-list and -export-dynamic-symbol. They make some
|
|
|
1160 // symbols private. Note that -export-dynamic takes precedence over them
|
|
|
1161 // as it says all symbols should be exported.
|
|
|
1162 if (!config->exportDynamic) {
|
|
|
1163 for (auto *arg : args.filtered(OPT_dynamic_list))
|
|
|
1164 if (Optional<MemoryBufferRef> buffer = readFile(arg->getValue()))
|
|
|
1165 readDynamicList(*buffer);
|
|
|
1166
|
|
|
1167 for (auto *arg : args.filtered(OPT_export_dynamic_symbol))
|
|
|
1168 config->dynamicList.push_back(
|
|
|
1169 {arg->getValue(), /*isExternCpp=*/false, /*hasWildcard=*/false});
|
|
|
1170 }
|
|
|
1171
|
|
|
1172 // If --export-dynamic-symbol=foo is given and symbol foo is defined in
|
|
|
1173 // an object file in an archive file, that object file should be pulled
|
|
|
1174 // out and linked. (It doesn't have to behave like that from technical
|
|
|
1175 // point of view, but this is needed for compatibility with GNU.)
|
|
|
1176 for (auto *arg : args.filtered(OPT_export_dynamic_symbol))
|
|
|
1177 config->undefined.push_back(arg->getValue());
|
|
|
1178
|
|
|
1179 for (auto *arg : args.filtered(OPT_version_script))
|
|
|
1180 if (Optional<std::string> path = searchScript(arg->getValue())) {
|
|
|
1181 if (Optional<MemoryBufferRef> buffer = readFile(*path))
|
|
|
1182 readVersionScript(*buffer);
|
|
|
1183 } else {
|
|
|
1184 error(Twine("cannot find version script ") + arg->getValue());
|
|
|
1185 }
|
|
|
1186 }
|
|
|
1187
|
|
|
1188 // Some Config members do not directly correspond to any particular
|
|
|
1189 // command line options, but computed based on other Config values.
|
|
|
1190 // This function initialize such members. See Config.h for the details
|
|
|
1191 // of these values.
|
|
|
1192 static void setConfigs(opt::InputArgList &args) {
|
|
|
1193 ELFKind k = config->ekind;
|
|
|
1194 uint16_t m = config->emachine;
|
|
|
1195
|
|
|
1196 config->copyRelocs = (config->relocatable || config->emitRelocs);
|
|
|
1197 config->is64 = (k == ELF64LEKind || k == ELF64BEKind);
|
|
|
1198 config->isLE = (k == ELF32LEKind || k == ELF64LEKind);
|
|
|
1199 config->endianness = config->isLE ? endianness::little : endianness::big;
|
|
|
1200 config->isMips64EL = (k == ELF64LEKind && m == EM_MIPS);
|
|
|
1201 config->isPic = config->pie || config->shared;
|
|
|
1202 config->picThunk = args.hasArg(OPT_pic_veneer, config->isPic);
|
|
|
1203 config->wordsize = config->is64 ? 8 : 4;
|
|
|
1204
|
|
|
1205 // ELF defines two different ways to store relocation addends as shown below:
|
|
|
1206 //
|
|
|
1207 // Rel: Addends are stored to the location where relocations are applied.
|
|
|
1208 // Rela: Addends are stored as part of relocation entry.
|
|
|
1209 //
|
|
|
1210 // In other words, Rela makes it easy to read addends at the price of extra
|
|
|
1211 // 4 or 8 byte for each relocation entry. We don't know why ELF defined two
|
|
|
1212 // different mechanisms in the first place, but this is how the spec is
|
|
|
1213 // defined.
|
|
|
1214 //
|
|
|
1215 // You cannot choose which one, Rel or Rela, you want to use. Instead each
|
|
|
1216 // ABI defines which one you need to use. The following expression expresses
|
|
|
1217 // that.
|
|
|
1218 config->isRela = m == EM_AARCH64 || m == EM_AMDGPU || m == EM_HEXAGON ||
|
|
|
1219 m == EM_PPC || m == EM_PPC64 || m == EM_RISCV ||
|
|
|
1220 m == EM_X86_64;
|
|
|
1221
|
|
|
1222 // If the output uses REL relocations we must store the dynamic relocation
|
|
|
1223 // addends to the output sections. We also store addends for RELA relocations
|
|
|
1224 // if --apply-dynamic-relocs is used.
|
|
|
1225 // We default to not writing the addends when using RELA relocations since
|
|
|
1226 // any standard conforming tool can find it in r_addend.
|
|
|
1227 config->writeAddends = args.hasFlag(OPT_apply_dynamic_relocs,
|
|
|
1228 OPT_no_apply_dynamic_relocs, false) ||
|
|
|
1229 !config->isRela;
|
|
|
1230
|
|
|
1231 config->tocOptimize =
|
|
|
1232 args.hasFlag(OPT_toc_optimize, OPT_no_toc_optimize, m == EM_PPC64);
|
|
|
1233 }
|
|
|
1234
|
|
|
1235 // Returns a value of "-format" option.
|
|
|
1236 static bool isFormatBinary(StringRef s) {
|
|
|
1237 if (s == "binary")
|
|
|
1238 return true;
|
|
|
1239 if (s == "elf" || s == "default")
|
|
|
1240 return false;
|
|
|
1241 error("unknown -format value: " + s +
|
|
|
1242 " (supported formats: elf, default, binary)");
|
|
|
1243 return false;
|
|
|
1244 }
|
|
|
1245
|
|
|
1246 void LinkerDriver::createFiles(opt::InputArgList &args) {
|
|
|
1247 // For --{push,pop}-state.
|
|
|
1248 std::vector<std::tuple<bool, bool, bool>> stack;
|
|
|
1249
|
|
|
1250 // Iterate over argv to process input files and positional arguments.
|
|
|
1251 for (auto *arg : args) {
|
|
|
1252 switch (arg->getOption().getID()) {
|
|
|
1253 case OPT_library:
|
|
|
1254 addLibrary(arg->getValue());
|
|
|
1255 break;
|
|
|
1256 case OPT_INPUT:
|
|
|
1257 addFile(arg->getValue(), /*withLOption=*/false);
|
|
|
1258 break;
|
|
|
1259 case OPT_defsym: {
|
|
|
1260 StringRef from;
|
|
|
1261 StringRef to;
|
|
|
1262 std::tie(from, to) = StringRef(arg->getValue()).split('=');
|
|
|
1263 if (from.empty() || to.empty())
|
|
|
1264 error("-defsym: syntax error: " + StringRef(arg->getValue()));
|
|
|
1265 else
|
|
|
1266 readDefsym(from, MemoryBufferRef(to, "-defsym"));
|
|
|
1267 break;
|
|
|
1268 }
|
|
|
1269 case OPT_script:
|
|
|
1270 if (Optional<std::string> path = searchScript(arg->getValue())) {
|
|
|
1271 if (Optional<MemoryBufferRef> mb = readFile(*path))
|
|
|
1272 readLinkerScript(*mb);
|
|
|
1273 break;
|
|
|
1274 }
|
|
|
1275 error(Twine("cannot find linker script ") + arg->getValue());
|
|
|
1276 break;
|
|
|
1277 case OPT_as_needed:
|
|
|
1278 config->asNeeded = true;
|
|
|
1279 break;
|
|
|
1280 case OPT_format:
|
|
|
1281 config->formatBinary = isFormatBinary(arg->getValue());
|
|
|
1282 break;
|
|
|
1283 case OPT_no_as_needed:
|
|
|
1284 config->asNeeded = false;
|
|
|
1285 break;
|
|
|
1286 case OPT_Bstatic:
|
|
|
1287 case OPT_omagic:
|
|
|
1288 case OPT_nmagic:
|
|
|
1289 config->isStatic = true;
|
|
|
1290 break;
|
|
|
1291 case OPT_Bdynamic:
|
|
|
1292 config->isStatic = false;
|
|
|
1293 break;
|
|
|
1294 case OPT_whole_archive:
|
|
|
1295 inWholeArchive = true;
|
|
|
1296 break;
|
|
|
1297 case OPT_no_whole_archive:
|
|
|
1298 inWholeArchive = false;
|
|
|
1299 break;
|
|
|
1300 case OPT_just_symbols:
|
|
|
1301 if (Optional<MemoryBufferRef> mb = readFile(arg->getValue())) {
|
|
|
1302 files.push_back(createObjectFile(*mb));
|
|
|
1303 files.back()->justSymbols = true;
|
|
|
1304 }
|
|
|
1305 break;
|
|
|
1306 case OPT_start_group:
|
|
|
1307 if (InputFile::isInGroup)
|
|
|
1308 error("nested --start-group");
|
|
|
1309 InputFile::isInGroup = true;
|
|
|
1310 break;
|
|
|
1311 case OPT_end_group:
|
|
|
1312 if (!InputFile::isInGroup)
|
|
|
1313 error("stray --end-group");
|
|
|
1314 InputFile::isInGroup = false;
|
|
|
1315 ++InputFile::nextGroupId;
|
|
|
1316 break;
|
|
|
1317 case OPT_start_lib:
|
|
|
1318 if (inLib)
|
|
|
1319 error("nested --start-lib");
|
|
|
1320 if (InputFile::isInGroup)
|
|
|
1321 error("may not nest --start-lib in --start-group");
|
|
|
1322 inLib = true;
|
|
|
1323 InputFile::isInGroup = true;
|
|
|
1324 break;
|
|
|
1325 case OPT_end_lib:
|
|
|
1326 if (!inLib)
|
|
|
1327 error("stray --end-lib");
|
|
|
1328 inLib = false;
|
|
|
1329 InputFile::isInGroup = false;
|
|
|
1330 ++InputFile::nextGroupId;
|
|
|
1331 break;
|
|
|
1332 case OPT_push_state:
|
|
|
1333 stack.emplace_back(config->asNeeded, config->isStatic, inWholeArchive);
|
|
|
1334 break;
|
|
|
1335 case OPT_pop_state:
|
|
|
1336 if (stack.empty()) {
|
|
|
1337 error("unbalanced --push-state/--pop-state");
|
|
|
1338 break;
|
|
|
1339 }
|
|
|
1340 std::tie(config->asNeeded, config->isStatic, inWholeArchive) = stack.back();
|
|
|
1341 stack.pop_back();
|
|
|
1342 break;
|
|
|
1343 }
|
|
|
1344 }
|
|
|
1345
|
|
|
1346 if (files.empty() && errorCount() == 0)
|
|
|
1347 error("no input files");
|
|
|
1348 }
|
|
|
1349
|
|
|
1350 // If -m <machine_type> was not given, infer it from object files.
|
|
|
1351 void LinkerDriver::inferMachineType() {
|
|
|
1352 if (config->ekind != ELFNoneKind)
|
|
|
1353 return;
|
|
|
1354
|
|
|
1355 for (InputFile *f : files) {
|
|
|
1356 if (f->ekind == ELFNoneKind)
|
|
|
1357 continue;
|
|
|
1358 config->ekind = f->ekind;
|
|
|
1359 config->emachine = f->emachine;
|
|
|
1360 config->osabi = f->osabi;
|
|
|
1361 config->mipsN32Abi = config->emachine == EM_MIPS && isMipsN32Abi(f);
|
|
|
1362 return;
|
|
|
1363 }
|
|
|
1364 error("target emulation unknown: -m or at least one .o file required");
|
|
|
1365 }
|
|
|
1366
|
|
|
1367 // Parse -z max-page-size=<value>. The default value is defined by
|
|
|
1368 // each target.
|
|
|
1369 static uint64_t getMaxPageSize(opt::InputArgList &args) {
|
|
|
1370 uint64_t val = args::getZOptionValue(args, OPT_z, "max-page-size",
|
|
|
1371 target->defaultMaxPageSize);
|
|
|
1372 if (!isPowerOf2_64(val))
|
|
|
1373 error("max-page-size: value isn't a power of 2");
|
|
|
1374 if (config->nmagic || config->omagic) {
|
|
|
1375 if (val != target->defaultMaxPageSize)
|
|
|
1376 warn("-z max-page-size set, but paging disabled by omagic or nmagic");
|
|
|
1377 return 1;
|
|
|
1378 }
|
|
|
1379 return val;
|
|
|
1380 }
|
|
|
1381
|
|
|
1382 // Parse -z common-page-size=<value>. The default value is defined by
|
|
|
1383 // each target.
|
|
|
1384 static uint64_t getCommonPageSize(opt::InputArgList &args) {
|
|
|
1385 uint64_t val = args::getZOptionValue(args, OPT_z, "common-page-size",
|
|
|
1386 target->defaultCommonPageSize);
|
|
|
1387 if (!isPowerOf2_64(val))
|
|
|
1388 error("common-page-size: value isn't a power of 2");
|
|
|
1389 if (config->nmagic || config->omagic) {
|
|
|
1390 if (val != target->defaultCommonPageSize)
|
|
|
1391 warn("-z common-page-size set, but paging disabled by omagic or nmagic");
|
|
|
1392 return 1;
|
|
|
1393 }
|
|
|
1394 // commonPageSize can't be larger than maxPageSize.
|
|
|
1395 if (val > config->maxPageSize)
|
|
|
1396 val = config->maxPageSize;
|
|
|
1397 return val;
|
|
|
1398 }
|
|
|
1399
|
|
|
1400 // Parses -image-base option.
|
|
|
1401 static Optional<uint64_t> getImageBase(opt::InputArgList &args) {
|
|
|
1402 // Because we are using "Config->maxPageSize" here, this function has to be
|
|
|
1403 // called after the variable is initialized.
|
|
|
1404 auto *arg = args.getLastArg(OPT_image_base);
|
|
|
1405 if (!arg)
|
|
|
1406 return None;
|
|
|
1407
|
|
|
1408 StringRef s = arg->getValue();
|
|
|
1409 uint64_t v;
|
|
|
1410 if (!to_integer(s, v)) {
|
|
|
1411 error("-image-base: number expected, but got " + s);
|
|
|
1412 return 0;
|
|
|
1413 }
|
|
|
1414 if ((v % config->maxPageSize) != 0)
|
|
|
1415 warn("-image-base: address isn't multiple of page size: " + s);
|
|
|
1416 return v;
|
|
|
1417 }
|
|
|
1418
|
|
|
1419 // Parses `--exclude-libs=lib,lib,...`.
|
|
|
1420 // The library names may be delimited by commas or colons.
|
|
|
1421 static DenseSet<StringRef> getExcludeLibs(opt::InputArgList &args) {
|
|
|
1422 DenseSet<StringRef> ret;
|
|
|
1423 for (auto *arg : args.filtered(OPT_exclude_libs)) {
|
|
|
1424 StringRef s = arg->getValue();
|
|
|
1425 for (;;) {
|
|
|
1426 size_t pos = s.find_first_of(",:");
|
|
|
1427 if (pos == StringRef::npos)
|
|
|
1428 break;
|
|
|
1429 ret.insert(s.substr(0, pos));
|
|
|
1430 s = s.substr(pos + 1);
|
|
|
1431 }
|
|
|
1432 ret.insert(s);
|
|
|
1433 }
|
|
|
1434 return ret;
|
|
|
1435 }
|
|
|
1436
|
|
|
1437 // Handles the -exclude-libs option. If a static library file is specified
|
|
|
1438 // by the -exclude-libs option, all public symbols from the archive become
|
|
|
1439 // private unless otherwise specified by version scripts or something.
|
|
|
1440 // A special library name "ALL" means all archive files.
|
|
|
1441 //
|
|
|
1442 // This is not a popular option, but some programs such as bionic libc use it.
|
|
|
1443 static void excludeLibs(opt::InputArgList &args) {
|
|
|
1444 DenseSet<StringRef> libs = getExcludeLibs(args);
|
|
|
1445 bool all = libs.count("ALL");
|
|
|
1446
|
|
|
1447 auto visit = [&](InputFile *file) {
|
|
|
1448 if (!file->archiveName.empty())
|
|
|
1449 if (all || libs.count(path::filename(file->archiveName)))
|
|
|
1450 for (Symbol *sym : file->getSymbols())
|
|
|
1451 if (!sym->isUndefined() && !sym->isLocal() && sym->file == file)
|
|
|
1452 sym->versionId = VER_NDX_LOCAL;
|
|
|
1453 };
|
|
|
1454
|
|
|
1455 for (InputFile *file : objectFiles)
|
|
|
1456 visit(file);
|
|
|
1457
|
|
|
1458 for (BitcodeFile *file : bitcodeFiles)
|
|
|
1459 visit(file);
|
|
|
1460 }
|
|
|
1461
|
|
|
1462 // Force Sym to be entered in the output. Used for -u or equivalent.
|
|
|
1463 static void handleUndefined(Symbol *sym) {
|
|
|
1464 // Since a symbol may not be used inside the program, LTO may
|
|
|
1465 // eliminate it. Mark the symbol as "used" to prevent it.
|
|
|
1466 sym->isUsedInRegularObj = true;
|
|
|
1467
|
|
173
|
1468 // GNU linkers allow -u foo -ldef -lref. We should not treat it as a backward
|
|
|
1469 // reference.
|
|
|
1470 backwardReferences.erase(sym);
|
|
|
1471
|
|
150
|
1472 if (sym->isLazy())
|
|
|
1473 sym->fetch();
|
|
|
1474 }
|
|
|
1475
|
|
|
1476 // As an extension to GNU linkers, lld supports a variant of `-u`
|
|
|
1477 // which accepts wildcard patterns. All symbols that match a given
|
|
|
1478 // pattern are handled as if they were given by `-u`.
|
|
|
1479 static void handleUndefinedGlob(StringRef arg) {
|
|
|
1480 Expected<GlobPattern> pat = GlobPattern::create(arg);
|
|
|
1481 if (!pat) {
|
|
|
1482 error("--undefined-glob: " + toString(pat.takeError()));
|
|
|
1483 return;
|
|
|
1484 }
|
|
|
1485
|
|
|
1486 std::vector<Symbol *> syms;
|
|
|
1487 for (Symbol *sym : symtab->symbols()) {
|
|
|
1488 // Calling Sym->fetch() from here is not safe because it may
|
|
|
1489 // add new symbols to the symbol table, invalidating the
|
|
|
1490 // current iterator. So we just keep a note.
|
|
|
1491 if (pat->match(sym->getName()))
|
|
|
1492 syms.push_back(sym);
|
|
|
1493 }
|
|
|
1494
|
|
|
1495 for (Symbol *sym : syms)
|
|
|
1496 handleUndefined(sym);
|
|
|
1497 }
|
|
|
1498
|
|
|
1499 static void handleLibcall(StringRef name) {
|
|
|
1500 Symbol *sym = symtab->find(name);
|
|
|
1501 if (!sym || !sym->isLazy())
|
|
|
1502 return;
|
|
|
1503
|
|
|
1504 MemoryBufferRef mb;
|
|
|
1505 if (auto *lo = dyn_cast<LazyObject>(sym))
|
|
|
1506 mb = lo->file->mb;
|
|
|
1507 else
|
|
|
1508 mb = cast<LazyArchive>(sym)->getMemberBuffer();
|
|
|
1509
|
|
|
1510 if (isBitcode(mb))
|
|
|
1511 sym->fetch();
|
|
|
1512 }
|
|
|
1513
|
|
|
1514 // Replaces common symbols with defined symbols reside in .bss sections.
|
|
|
1515 // This function is called after all symbol names are resolved. As a
|
|
|
1516 // result, the passes after the symbol resolution won't see any
|
|
|
1517 // symbols of type CommonSymbol.
|
|
|
1518 static void replaceCommonSymbols() {
|
|
|
1519 for (Symbol *sym : symtab->symbols()) {
|
|
|
1520 auto *s = dyn_cast<CommonSymbol>(sym);
|
|
|
1521 if (!s)
|
|
|
1522 continue;
|
|
|
1523
|
|
|
1524 auto *bss = make<BssSection>("COMMON", s->size, s->alignment);
|
|
|
1525 bss->file = s->file;
|
|
|
1526 bss->markDead();
|
|
|
1527 inputSections.push_back(bss);
|
|
|
1528 s->replace(Defined{s->file, s->getName(), s->binding, s->stOther, s->type,
|
|
|
1529 /*value=*/0, s->size, bss});
|
|
|
1530 }
|
|
|
1531 }
|
|
|
1532
|
|
|
1533 // If all references to a DSO happen to be weak, the DSO is not added
|
|
|
1534 // to DT_NEEDED. If that happens, we need to eliminate shared symbols
|
|
|
1535 // created from the DSO. Otherwise, they become dangling references
|
|
|
1536 // that point to a non-existent DSO.
|
|
|
1537 static void demoteSharedSymbols() {
|
|
|
1538 for (Symbol *sym : symtab->symbols()) {
|
|
|
1539 auto *s = dyn_cast<SharedSymbol>(sym);
|
|
|
1540 if (!s || s->getFile().isNeeded)
|
|
|
1541 continue;
|
|
|
1542
|
|
|
1543 bool used = s->used;
|
|
|
1544 s->replace(Undefined{nullptr, s->getName(), STB_WEAK, s->stOther, s->type});
|
|
|
1545 s->used = used;
|
|
|
1546 }
|
|
|
1547 }
|
|
|
1548
|
|
|
1549 // The section referred to by `s` is considered address-significant. Set the
|
|
|
1550 // keepUnique flag on the section if appropriate.
|
|
|
1551 static void markAddrsig(Symbol *s) {
|
|
|
1552 if (auto *d = dyn_cast_or_null<Defined>(s))
|
|
|
1553 if (d->section)
|
|
|
1554 // We don't need to keep text sections unique under --icf=all even if they
|
|
|
1555 // are address-significant.
|
|
|
1556 if (config->icf == ICFLevel::Safe || !(d->section->flags & SHF_EXECINSTR))
|
|
|
1557 d->section->keepUnique = true;
|
|
|
1558 }
|
|
|
1559
|
|
|
1560 // Record sections that define symbols mentioned in --keep-unique <symbol>
|
|
|
1561 // and symbols referred to by address-significance tables. These sections are
|
|
|
1562 // ineligible for ICF.
|
|
|
1563 template <class ELFT>
|
|
|
1564 static void findKeepUniqueSections(opt::InputArgList &args) {
|
|
|
1565 for (auto *arg : args.filtered(OPT_keep_unique)) {
|
|
|
1566 StringRef name = arg->getValue();
|
|
|
1567 auto *d = dyn_cast_or_null<Defined>(symtab->find(name));
|
|
|
1568 if (!d || !d->section) {
|
|
|
1569 warn("could not find symbol " + name + " to keep unique");
|
|
|
1570 continue;
|
|
|
1571 }
|
|
|
1572 d->section->keepUnique = true;
|
|
|
1573 }
|
|
|
1574
|
|
|
1575 // --icf=all --ignore-data-address-equality means that we can ignore
|
|
|
1576 // the dynsym and address-significance tables entirely.
|
|
|
1577 if (config->icf == ICFLevel::All && config->ignoreDataAddressEquality)
|
|
|
1578 return;
|
|
|
1579
|
|
|
1580 // Symbols in the dynsym could be address-significant in other executables
|
|
|
1581 // or DSOs, so we conservatively mark them as address-significant.
|
|
|
1582 for (Symbol *sym : symtab->symbols())
|
|
|
1583 if (sym->includeInDynsym())
|
|
|
1584 markAddrsig(sym);
|
|
|
1585
|
|
|
1586 // Visit the address-significance table in each object file and mark each
|
|
|
1587 // referenced symbol as address-significant.
|
|
|
1588 for (InputFile *f : objectFiles) {
|
|
|
1589 auto *obj = cast<ObjFile<ELFT>>(f);
|
|
|
1590 ArrayRef<Symbol *> syms = obj->getSymbols();
|
|
|
1591 if (obj->addrsigSec) {
|
|
|
1592 ArrayRef<uint8_t> contents =
|
|
|
1593 check(obj->getObj().getSectionContents(obj->addrsigSec));
|
|
|
1594 const uint8_t *cur = contents.begin();
|
|
|
1595 while (cur != contents.end()) {
|
|
|
1596 unsigned size;
|
|
|
1597 const char *err;
|
|
|
1598 uint64_t symIndex = decodeULEB128(cur, &size, contents.end(), &err);
|
|
|
1599 if (err)
|
|
|
1600 fatal(toString(f) + ": could not decode addrsig section: " + err);
|
|
|
1601 markAddrsig(syms[symIndex]);
|
|
|
1602 cur += size;
|
|
|
1603 }
|
|
|
1604 } else {
|
|
|
1605 // If an object file does not have an address-significance table,
|
|
|
1606 // conservatively mark all of its symbols as address-significant.
|
|
|
1607 for (Symbol *s : syms)
|
|
|
1608 markAddrsig(s);
|
|
|
1609 }
|
|
|
1610 }
|
|
|
1611 }
|
|
|
1612
|
|
|
1613 // This function reads a symbol partition specification section. These sections
|
|
|
1614 // are used to control which partition a symbol is allocated to. See
|
|
|
1615 // https://lld.llvm.org/Partitions.html for more details on partitions.
|
|
|
1616 template <typename ELFT>
|
|
|
1617 static void readSymbolPartitionSection(InputSectionBase *s) {
|
|
|
1618 // Read the relocation that refers to the partition's entry point symbol.
|
|
|
1619 Symbol *sym;
|
|
|
1620 if (s->areRelocsRela)
|
|
|
1621 sym = &s->getFile<ELFT>()->getRelocTargetSym(s->template relas<ELFT>()[0]);
|
|
|
1622 else
|
|
|
1623 sym = &s->getFile<ELFT>()->getRelocTargetSym(s->template rels<ELFT>()[0]);
|
|
|
1624 if (!isa<Defined>(sym) || !sym->includeInDynsym())
|
|
|
1625 return;
|
|
|
1626
|
|
|
1627 StringRef partName = reinterpret_cast<const char *>(s->data().data());
|
|
|
1628 for (Partition &part : partitions) {
|
|
|
1629 if (part.name == partName) {
|
|
|
1630 sym->partition = part.getNumber();
|
|
|
1631 return;
|
|
|
1632 }
|
|
|
1633 }
|
|
|
1634
|
|
|
1635 // Forbid partitions from being used on incompatible targets, and forbid them
|
|
|
1636 // from being used together with various linker features that assume a single
|
|
|
1637 // set of output sections.
|
|
|
1638 if (script->hasSectionsCommand)
|
|
|
1639 error(toString(s->file) +
|
|
|
1640 ": partitions cannot be used with the SECTIONS command");
|
|
|
1641 if (script->hasPhdrsCommands())
|
|
|
1642 error(toString(s->file) +
|
|
|
1643 ": partitions cannot be used with the PHDRS command");
|
|
|
1644 if (!config->sectionStartMap.empty())
|
|
|
1645 error(toString(s->file) + ": partitions cannot be used with "
|
|
|
1646 "--section-start, -Ttext, -Tdata or -Tbss");
|
|
|
1647 if (config->emachine == EM_MIPS)
|
|
|
1648 error(toString(s->file) + ": partitions cannot be used on this target");
|
|
|
1649
|
|
|
1650 // Impose a limit of no more than 254 partitions. This limit comes from the
|
|
|
1651 // sizes of the Partition fields in InputSectionBase and Symbol, as well as
|
|
|
1652 // the amount of space devoted to the partition number in RankFlags.
|
|
|
1653 if (partitions.size() == 254)
|
|
|
1654 fatal("may not have more than 254 partitions");
|
|
|
1655
|
|
|
1656 partitions.emplace_back();
|
|
|
1657 Partition &newPart = partitions.back();
|
|
|
1658 newPart.name = partName;
|
|
|
1659 sym->partition = newPart.getNumber();
|
|
|
1660 }
|
|
|
1661
|
|
|
1662 static Symbol *addUndefined(StringRef name) {
|
|
|
1663 return symtab->addSymbol(
|
|
|
1664 Undefined{nullptr, name, STB_GLOBAL, STV_DEFAULT, 0});
|
|
|
1665 }
|
|
|
1666
|
|
|
1667 // This function is where all the optimizations of link-time
|
|
|
1668 // optimization takes place. When LTO is in use, some input files are
|
|
|
1669 // not in native object file format but in the LLVM bitcode format.
|
|
|
1670 // This function compiles bitcode files into a few big native files
|
|
|
1671 // using LLVM functions and replaces bitcode symbols with the results.
|
|
|
1672 // Because all bitcode files that the program consists of are passed to
|
|
|
1673 // the compiler at once, it can do a whole-program optimization.
|
|
|
1674 template <class ELFT> void LinkerDriver::compileBitcodeFiles() {
|
|
|
1675 llvm::TimeTraceScope timeScope("LTO");
|
|
|
1676 // Compile bitcode files and replace bitcode symbols.
|
|
|
1677 lto.reset(new BitcodeCompiler);
|
|
|
1678 for (BitcodeFile *file : bitcodeFiles)
|
|
|
1679 lto->add(*file);
|
|
|
1680
|
|
|
1681 for (InputFile *file : lto->compile()) {
|
|
|
1682 auto *obj = cast<ObjFile<ELFT>>(file);
|
|
|
1683 obj->parse(/*ignoreComdats=*/true);
|
|
|
1684 for (Symbol *sym : obj->getGlobalSymbols())
|
|
|
1685 sym->parseSymbolVersion();
|
|
|
1686 objectFiles.push_back(file);
|
|
|
1687 }
|
|
|
1688 }
|
|
|
1689
|
|
|
1690 // The --wrap option is a feature to rename symbols so that you can write
|
|
|
1691 // wrappers for existing functions. If you pass `-wrap=foo`, all
|
|
|
1692 // occurrences of symbol `foo` are resolved to `wrap_foo` (so, you are
|
|
|
1693 // expected to write `wrap_foo` function as a wrapper). The original
|
|
|
1694 // symbol becomes accessible as `real_foo`, so you can call that from your
|
|
|
1695 // wrapper.
|
|
|
1696 //
|
|
|
1697 // This data structure is instantiated for each -wrap option.
|
|
|
1698 struct WrappedSymbol {
|
|
|
1699 Symbol *sym;
|
|
|
1700 Symbol *real;
|
|
|
1701 Symbol *wrap;
|
|
|
1702 };
|
|
|
1703
|
|
|
1704 // Handles -wrap option.
|
|
|
1705 //
|
|
|
1706 // This function instantiates wrapper symbols. At this point, they seem
|
|
|
1707 // like they are not being used at all, so we explicitly set some flags so
|
|
|
1708 // that LTO won't eliminate them.
|
|
|
1709 static std::vector<WrappedSymbol> addWrappedSymbols(opt::InputArgList &args) {
|
|
|
1710 std::vector<WrappedSymbol> v;
|
|
|
1711 DenseSet<StringRef> seen;
|
|
|
1712
|
|
|
1713 for (auto *arg : args.filtered(OPT_wrap)) {
|
|
|
1714 StringRef name = arg->getValue();
|
|
|
1715 if (!seen.insert(name).second)
|
|
|
1716 continue;
|
|
|
1717
|
|
|
1718 Symbol *sym = symtab->find(name);
|
|
|
1719 if (!sym)
|
|
|
1720 continue;
|
|
|
1721
|
|
|
1722 Symbol *real = addUndefined(saver.save("__real_" + name));
|
|
|
1723 Symbol *wrap = addUndefined(saver.save("__wrap_" + name));
|
|
|
1724 v.push_back({sym, real, wrap});
|
|
|
1725
|
|
|
1726 // We want to tell LTO not to inline symbols to be overwritten
|
|
|
1727 // because LTO doesn't know the final symbol contents after renaming.
|
|
|
1728 real->canInline = false;
|
|
|
1729 sym->canInline = false;
|
|
|
1730
|
|
|
1731 // Tell LTO not to eliminate these symbols.
|
|
|
1732 sym->isUsedInRegularObj = true;
|
|
|
1733 wrap->isUsedInRegularObj = true;
|
|
|
1734 }
|
|
|
1735 return v;
|
|
|
1736 }
|
|
|
1737
|
|
|
1738 // Do renaming for -wrap by updating pointers to symbols.
|
|
|
1739 //
|
|
|
1740 // When this function is executed, only InputFiles and symbol table
|
|
|
1741 // contain pointers to symbol objects. We visit them to replace pointers,
|
|
|
1742 // so that wrapped symbols are swapped as instructed by the command line.
|
|
|
1743 static void wrapSymbols(ArrayRef<WrappedSymbol> wrapped) {
|
|
|
1744 DenseMap<Symbol *, Symbol *> map;
|
|
|
1745 for (const WrappedSymbol &w : wrapped) {
|
|
|
1746 map[w.sym] = w.wrap;
|
|
|
1747 map[w.real] = w.sym;
|
|
|
1748 }
|
|
|
1749
|
|
|
1750 // Update pointers in input files.
|
|
|
1751 parallelForEach(objectFiles, [&](InputFile *file) {
|
|
|
1752 MutableArrayRef<Symbol *> syms = file->getMutableSymbols();
|
|
|
1753 for (size_t i = 0, e = syms.size(); i != e; ++i)
|
|
|
1754 if (Symbol *s = map.lookup(syms[i]))
|
|
|
1755 syms[i] = s;
|
|
|
1756 });
|
|
|
1757
|
|
|
1758 // Update pointers in the symbol table.
|
|
|
1759 for (const WrappedSymbol &w : wrapped)
|
|
|
1760 symtab->wrap(w.sym, w.real, w.wrap);
|
|
|
1761 }
|
|
|
1762
|
|
|
1763 // To enable CET (x86's hardware-assited control flow enforcement), each
|
|
|
1764 // source file must be compiled with -fcf-protection. Object files compiled
|
|
|
1765 // with the flag contain feature flags indicating that they are compatible
|
|
|
1766 // with CET. We enable the feature only when all object files are compatible
|
|
|
1767 // with CET.
|
|
|
1768 //
|
|
|
1769 // This is also the case with AARCH64's BTI and PAC which use the similar
|
|
|
1770 // GNU_PROPERTY_AARCH64_FEATURE_1_AND mechanism.
|
|
|
1771 template <class ELFT> static uint32_t getAndFeatures() {
|
|
|
1772 if (config->emachine != EM_386 && config->emachine != EM_X86_64 &&
|
|
|
1773 config->emachine != EM_AARCH64)
|
|
|
1774 return 0;
|
|
|
1775
|
|
|
1776 uint32_t ret = -1;
|
|
|
1777 for (InputFile *f : objectFiles) {
|
|
|
1778 uint32_t features = cast<ObjFile<ELFT>>(f)->andFeatures;
|
|
173
|
1779 if (config->zForceBti && !(features & GNU_PROPERTY_AARCH64_FEATURE_1_BTI)) {
|
|
|
1780 warn(toString(f) + ": -z force-bti: file does not have "
|
|
|
1781 "GNU_PROPERTY_AARCH64_FEATURE_1_BTI property");
|
|
150
|
1782 features |= GNU_PROPERTY_AARCH64_FEATURE_1_BTI;
|
|
|
1783 } else if (config->zForceIbt &&
|
|
|
1784 !(features & GNU_PROPERTY_X86_FEATURE_1_IBT)) {
|
|
|
1785 warn(toString(f) + ": -z force-ibt: file does not have "
|
|
|
1786 "GNU_PROPERTY_X86_FEATURE_1_IBT property");
|
|
|
1787 features |= GNU_PROPERTY_X86_FEATURE_1_IBT;
|
|
|
1788 }
|
|
173
|
1789 if (config->zPacPlt && !(features & GNU_PROPERTY_AARCH64_FEATURE_1_PAC)) {
|
|
|
1790 warn(toString(f) + ": -z pac-plt: file does not have "
|
|
|
1791 "GNU_PROPERTY_AARCH64_FEATURE_1_PAC property");
|
|
|
1792 features |= GNU_PROPERTY_AARCH64_FEATURE_1_PAC;
|
|
|
1793 }
|
|
150
|
1794 ret &= features;
|
|
|
1795 }
|
|
|
1796
|
|
|
1797 // Force enable Shadow Stack.
|
|
|
1798 if (config->zShstk)
|
|
|
1799 ret |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
|
|
|
1800
|
|
|
1801 return ret;
|
|
|
1802 }
|
|
|
1803
|
|
|
1804 // Do actual linking. Note that when this function is called,
|
|
|
1805 // all linker scripts have already been parsed.
|
|
|
1806 template <class ELFT> void LinkerDriver::link(opt::InputArgList &args) {
|
|
|
1807 llvm::TimeTraceScope timeScope("Link", StringRef("LinkerDriver::Link"));
|
|
|
1808 // If a -hash-style option was not given, set to a default value,
|
|
|
1809 // which varies depending on the target.
|
|
|
1810 if (!args.hasArg(OPT_hash_style)) {
|
|
|
1811 if (config->emachine == EM_MIPS)
|
|
|
1812 config->sysvHash = true;
|
|
|
1813 else
|
|
|
1814 config->sysvHash = config->gnuHash = true;
|
|
|
1815 }
|
|
|
1816
|
|
|
1817 // Default output filename is "a.out" by the Unix tradition.
|
|
|
1818 if (config->outputFile.empty())
|
|
|
1819 config->outputFile = "a.out";
|
|
|
1820
|
|
|
1821 // Fail early if the output file or map file is not writable. If a user has a
|
|
|
1822 // long link, e.g. due to a large LTO link, they do not wish to run it and
|
|
|
1823 // find that it failed because there was a mistake in their command-line.
|
|
|
1824 if (auto e = tryCreateFile(config->outputFile))
|
|
|
1825 error("cannot open output file " + config->outputFile + ": " + e.message());
|
|
|
1826 if (auto e = tryCreateFile(config->mapFile))
|
|
|
1827 error("cannot open map file " + config->mapFile + ": " + e.message());
|
|
|
1828 if (errorCount())
|
|
|
1829 return;
|
|
|
1830
|
|
|
1831 // Use default entry point name if no name was given via the command
|
|
|
1832 // line nor linker scripts. For some reason, MIPS entry point name is
|
|
|
1833 // different from others.
|
|
|
1834 config->warnMissingEntry =
|
|
|
1835 (!config->entry.empty() || (!config->shared && !config->relocatable));
|
|
|
1836 if (config->entry.empty() && !config->relocatable)
|
|
|
1837 config->entry = (config->emachine == EM_MIPS) ? "__start" : "_start";
|
|
|
1838
|
|
|
1839 // Handle --trace-symbol.
|
|
|
1840 for (auto *arg : args.filtered(OPT_trace_symbol))
|
|
|
1841 symtab->insert(arg->getValue())->traced = true;
|
|
|
1842
|
|
|
1843 // Add all files to the symbol table. This will add almost all
|
|
|
1844 // symbols that we need to the symbol table. This process might
|
|
|
1845 // add files to the link, via autolinking, these files are always
|
|
|
1846 // appended to the Files vector.
|
|
|
1847 {
|
|
|
1848 llvm::TimeTraceScope timeScope("Parse input files");
|
|
|
1849 for (size_t i = 0; i < files.size(); ++i)
|
|
|
1850 parseFile(files[i]);
|
|
|
1851 }
|
|
|
1852
|
|
|
1853 // Now that we have every file, we can decide if we will need a
|
|
|
1854 // dynamic symbol table.
|
|
|
1855 // We need one if we were asked to export dynamic symbols or if we are
|
|
|
1856 // producing a shared library.
|
|
|
1857 // We also need one if any shared libraries are used and for pie executables
|
|
|
1858 // (probably because the dynamic linker needs it).
|
|
|
1859 config->hasDynSymTab =
|
|
|
1860 !sharedFiles.empty() || config->isPic || config->exportDynamic;
|
|
|
1861
|
|
|
1862 // Some symbols (such as __ehdr_start) are defined lazily only when there
|
|
|
1863 // are undefined symbols for them, so we add these to trigger that logic.
|
|
|
1864 for (StringRef name : script->referencedSymbols)
|
|
|
1865 addUndefined(name);
|
|
|
1866
|
|
|
1867 // Handle the `--undefined <sym>` options.
|
|
|
1868 for (StringRef arg : config->undefined)
|
|
|
1869 if (Symbol *sym = symtab->find(arg))
|
|
|
1870 handleUndefined(sym);
|
|
|
1871
|
|
|
1872 // If an entry symbol is in a static archive, pull out that file now.
|
|
|
1873 if (Symbol *sym = symtab->find(config->entry))
|
|
|
1874 handleUndefined(sym);
|
|
|
1875
|
|
|
1876 // Handle the `--undefined-glob <pattern>` options.
|
|
|
1877 for (StringRef pat : args::getStrings(args, OPT_undefined_glob))
|
|
|
1878 handleUndefinedGlob(pat);
|
|
|
1879
|
|
|
1880 // Mark -init and -fini symbols so that the LTO doesn't eliminate them.
|
|
|
1881 if (Symbol *sym = symtab->find(config->init))
|
|
|
1882 sym->isUsedInRegularObj = true;
|
|
|
1883 if (Symbol *sym = symtab->find(config->fini))
|
|
|
1884 sym->isUsedInRegularObj = true;
|
|
|
1885
|
|
|
1886 // If any of our inputs are bitcode files, the LTO code generator may create
|
|
|
1887 // references to certain library functions that might not be explicit in the
|
|
|
1888 // bitcode file's symbol table. If any of those library functions are defined
|
|
|
1889 // in a bitcode file in an archive member, we need to arrange to use LTO to
|
|
|
1890 // compile those archive members by adding them to the link beforehand.
|
|
|
1891 //
|
|
|
1892 // However, adding all libcall symbols to the link can have undesired
|
|
|
1893 // consequences. For example, the libgcc implementation of
|
|
|
1894 // __sync_val_compare_and_swap_8 on 32-bit ARM pulls in an .init_array entry
|
|
|
1895 // that aborts the program if the Linux kernel does not support 64-bit
|
|
|
1896 // atomics, which would prevent the program from running even if it does not
|
|
|
1897 // use 64-bit atomics.
|
|
|
1898 //
|
|
|
1899 // Therefore, we only add libcall symbols to the link before LTO if we have
|
|
|
1900 // to, i.e. if the symbol's definition is in bitcode. Any other required
|
|
|
1901 // libcall symbols will be added to the link after LTO when we add the LTO
|
|
|
1902 // object file to the link.
|
|
|
1903 if (!bitcodeFiles.empty())
|
|
|
1904 for (auto *s : lto::LTO::getRuntimeLibcallSymbols())
|
|
|
1905 handleLibcall(s);
|
|
|
1906
|
|
|
1907 // Return if there were name resolution errors.
|
|
|
1908 if (errorCount())
|
|
|
1909 return;
|
|
|
1910
|
|
|
1911 // We want to declare linker script's symbols early,
|
|
|
1912 // so that we can version them.
|
|
|
1913 // They also might be exported if referenced by DSOs.
|
|
|
1914 script->declareSymbols();
|
|
|
1915
|
|
|
1916 // Handle the -exclude-libs option.
|
|
|
1917 if (args.hasArg(OPT_exclude_libs))
|
|
|
1918 excludeLibs(args);
|
|
|
1919
|
|
|
1920 // Create elfHeader early. We need a dummy section in
|
|
|
1921 // addReservedSymbols to mark the created symbols as not absolute.
|
|
|
1922 Out::elfHeader = make<OutputSection>("", 0, SHF_ALLOC);
|
|
|
1923 Out::elfHeader->size = sizeof(typename ELFT::Ehdr);
|
|
|
1924
|
|
|
1925 // Create wrapped symbols for -wrap option.
|
|
|
1926 std::vector<WrappedSymbol> wrapped = addWrappedSymbols(args);
|
|
|
1927
|
|
|
1928 // We need to create some reserved symbols such as _end. Create them.
|
|
|
1929 if (!config->relocatable)
|
|
|
1930 addReservedSymbols();
|
|
|
1931
|
|
|
1932 // Apply version scripts.
|
|
|
1933 //
|
|
|
1934 // For a relocatable output, version scripts don't make sense, and
|
|
|
1935 // parsing a symbol version string (e.g. dropping "@ver1" from a symbol
|
|
|
1936 // name "foo@ver1") rather do harm, so we don't call this if -r is given.
|
|
|
1937 if (!config->relocatable)
|
|
|
1938 symtab->scanVersionScript();
|
|
|
1939
|
|
|
1940 // Do link-time optimization if given files are LLVM bitcode files.
|
|
|
1941 // This compiles bitcode files into real object files.
|
|
|
1942 //
|
|
|
1943 // With this the symbol table should be complete. After this, no new names
|
|
|
1944 // except a few linker-synthesized ones will be added to the symbol table.
|
|
|
1945 compileBitcodeFiles<ELFT>();
|
|
173
|
1946
|
|
|
1947 // Symbol resolution finished. Report backward reference problems.
|
|
|
1948 reportBackrefs();
|
|
150
|
1949 if (errorCount())
|
|
|
1950 return;
|
|
|
1951
|
|
|
1952 // If -thinlto-index-only is given, we should create only "index
|
|
|
1953 // files" and not object files. Index file creation is already done
|
|
|
1954 // in addCombinedLTOObject, so we are done if that's the case.
|
|
173
|
1955 // Likewise, --plugin-opt=emit-llvm and --plugin-opt=emit-asm are the
|
|
|
1956 // options to create output files in bitcode or assembly code
|
|
|
1957 // repsectively. No object files are generated.
|
|
|
1958 if (config->thinLTOIndexOnly || config->emitLLVM || config->ltoEmitAsm)
|
|
150
|
1959 return;
|
|
|
1960
|
|
|
1961 // Apply symbol renames for -wrap.
|
|
|
1962 if (!wrapped.empty())
|
|
|
1963 wrapSymbols(wrapped);
|
|
|
1964
|
|
|
1965 // Now that we have a complete list of input files.
|
|
|
1966 // Beyond this point, no new files are added.
|
|
|
1967 // Aggregate all input sections into one place.
|
|
|
1968 for (InputFile *f : objectFiles)
|
|
|
1969 for (InputSectionBase *s : f->getSections())
|
|
|
1970 if (s && s != &InputSection::discarded)
|
|
|
1971 inputSections.push_back(s);
|
|
|
1972 for (BinaryFile *f : binaryFiles)
|
|
|
1973 for (InputSectionBase *s : f->getSections())
|
|
|
1974 inputSections.push_back(cast<InputSection>(s));
|
|
|
1975
|
|
|
1976 llvm::erase_if(inputSections, [](InputSectionBase *s) {
|
|
|
1977 if (s->type == SHT_LLVM_SYMPART) {
|
|
|
1978 readSymbolPartitionSection<ELFT>(s);
|
|
|
1979 return true;
|
|
|
1980 }
|
|
|
1981
|
|
|
1982 // We do not want to emit debug sections if --strip-all
|
|
|
1983 // or -strip-debug are given.
|
|
173
|
1984 if (config->strip == StripPolicy::None)
|
|
|
1985 return false;
|
|
|
1986
|
|
|
1987 if (isDebugSection(*s))
|
|
|
1988 return true;
|
|
|
1989 if (auto *isec = dyn_cast<InputSection>(s))
|
|
|
1990 if (InputSectionBase *rel = isec->getRelocatedSection())
|
|
|
1991 if (isDebugSection(*rel))
|
|
|
1992 return true;
|
|
|
1993
|
|
|
1994 return false;
|
|
150
|
1995 });
|
|
|
1996
|
|
|
1997 // Now that the number of partitions is fixed, save a pointer to the main
|
|
|
1998 // partition.
|
|
|
1999 mainPart = &partitions[0];
|
|
|
2000
|
|
|
2001 // Read .note.gnu.property sections from input object files which
|
|
|
2002 // contain a hint to tweak linker's and loader's behaviors.
|
|
|
2003 config->andFeatures = getAndFeatures<ELFT>();
|
|
|
2004
|
|
|
2005 // The Target instance handles target-specific stuff, such as applying
|
|
|
2006 // relocations or writing a PLT section. It also contains target-dependent
|
|
|
2007 // values such as a default image base address.
|
|
|
2008 target = getTarget();
|
|
|
2009
|
|
|
2010 config->eflags = target->calcEFlags();
|
|
|
2011 // maxPageSize (sometimes called abi page size) is the maximum page size that
|
|
|
2012 // the output can be run on. For example if the OS can use 4k or 64k page
|
|
|
2013 // sizes then maxPageSize must be 64k for the output to be useable on both.
|
|
|
2014 // All important alignment decisions must use this value.
|
|
|
2015 config->maxPageSize = getMaxPageSize(args);
|
|
|
2016 // commonPageSize is the most common page size that the output will be run on.
|
|
|
2017 // For example if an OS can use 4k or 64k page sizes and 4k is more common
|
|
|
2018 // than 64k then commonPageSize is set to 4k. commonPageSize can be used for
|
|
|
2019 // optimizations such as DATA_SEGMENT_ALIGN in linker scripts. LLD's use of it
|
|
|
2020 // is limited to writing trap instructions on the last executable segment.
|
|
|
2021 config->commonPageSize = getCommonPageSize(args);
|
|
|
2022
|
|
|
2023 config->imageBase = getImageBase(args);
|
|
|
2024
|
|
|
2025 if (config->emachine == EM_ARM) {
|
|
|
2026 // FIXME: These warnings can be removed when lld only uses these features
|
|
|
2027 // when the input objects have been compiled with an architecture that
|
|
|
2028 // supports them.
|
|
|
2029 if (config->armHasBlx == false)
|
|
|
2030 warn("lld uses blx instruction, no object with architecture supporting "
|
|
|
2031 "feature detected");
|
|
|
2032 }
|
|
|
2033
|
|
|
2034 // This adds a .comment section containing a version string.
|
|
|
2035 if (!config->relocatable)
|
|
|
2036 inputSections.push_back(createCommentSection());
|
|
|
2037
|
|
|
2038 // Replace common symbols with regular symbols.
|
|
|
2039 replaceCommonSymbols();
|
|
|
2040
|
|
|
2041 // Split SHF_MERGE and .eh_frame sections into pieces in preparation for garbage collection.
|
|
|
2042 splitSections<ELFT>();
|
|
|
2043
|
|
|
2044 // Garbage collection and removal of shared symbols from unused shared objects.
|
|
|
2045 markLive<ELFT>();
|
|
|
2046 demoteSharedSymbols();
|
|
|
2047
|
|
|
2048 // Make copies of any input sections that need to be copied into each
|
|
|
2049 // partition.
|
|
|
2050 copySectionsIntoPartitions();
|
|
|
2051
|
|
|
2052 // Create synthesized sections such as .got and .plt. This is called before
|
|
|
2053 // processSectionCommands() so that they can be placed by SECTIONS commands.
|
|
|
2054 createSyntheticSections<ELFT>();
|
|
|
2055
|
|
|
2056 // Some input sections that are used for exception handling need to be moved
|
|
|
2057 // into synthetic sections. Do that now so that they aren't assigned to
|
|
|
2058 // output sections in the usual way.
|
|
|
2059 if (!config->relocatable)
|
|
|
2060 combineEhSections();
|
|
|
2061
|
|
|
2062 // Create output sections described by SECTIONS commands.
|
|
|
2063 script->processSectionCommands();
|
|
|
2064
|
|
|
2065 // Linker scripts control how input sections are assigned to output sections.
|
|
|
2066 // Input sections that were not handled by scripts are called "orphans", and
|
|
|
2067 // they are assigned to output sections by the default rule. Process that.
|
|
|
2068 script->addOrphanSections();
|
|
|
2069
|
|
|
2070 // Migrate InputSectionDescription::sectionBases to sections. This includes
|
|
|
2071 // merging MergeInputSections into a single MergeSyntheticSection. From this
|
|
|
2072 // point onwards InputSectionDescription::sections should be used instead of
|
|
|
2073 // sectionBases.
|
|
|
2074 for (BaseCommand *base : script->sectionCommands)
|
|
|
2075 if (auto *sec = dyn_cast<OutputSection>(base))
|
|
|
2076 sec->finalizeInputSections();
|
|
|
2077 llvm::erase_if(inputSections,
|
|
|
2078 [](InputSectionBase *s) { return isa<MergeInputSection>(s); });
|
|
|
2079
|
|
|
2080 // Two input sections with different output sections should not be folded.
|
|
|
2081 // ICF runs after processSectionCommands() so that we know the output sections.
|
|
|
2082 if (config->icf != ICFLevel::None) {
|
|
|
2083 findKeepUniqueSections<ELFT>(args);
|
|
|
2084 doIcf<ELFT>();
|
|
|
2085 }
|
|
|
2086
|
|
|
2087 // Read the callgraph now that we know what was gced or icfed
|
|
|
2088 if (config->callGraphProfileSort) {
|
|
|
2089 if (auto *arg = args.getLastArg(OPT_call_graph_ordering_file))
|
|
|
2090 if (Optional<MemoryBufferRef> buffer = readFile(arg->getValue()))
|
|
|
2091 readCallGraph(*buffer);
|
|
|
2092 readCallGraphsFromObjectFiles<ELFT>();
|
|
|
2093 }
|
|
|
2094
|
|
|
2095 // Write the result to the file.
|
|
|
2096 writeResult<ELFT>();
|
|
|
2097 }
|
