1 //===------ ObjectFileInterface.cpp - MU interface utils for objects ------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/ExecutionEngine/Orc/ObjectFileInterface.h" 10 #include "llvm/ExecutionEngine/Orc/ELFNixPlatform.h" 11 #include "llvm/ExecutionEngine/Orc/MachOPlatform.h" 12 #include "llvm/Object/ELFObjectFile.h" 13 #include "llvm/Object/MachO.h" 14 #include "llvm/Object/ObjectFile.h" 15 #include "llvm/Support/Debug.h" 16 17 #define DEBUG_TYPE "orc" 18 19 namespace llvm { 20 namespace orc { 21 22 void addInitSymbol(MaterializationUnit::Interface &I, ExecutionSession &ES, 23 StringRef ObjFileName) { 24 assert(!I.InitSymbol && "I already has an init symbol"); 25 size_t Counter = 0; 26 27 do { 28 std::string InitSymString; 29 raw_string_ostream(InitSymString) 30 << "$." << ObjFileName << ".__inits." << Counter++; 31 I.InitSymbol = ES.intern(InitSymString); 32 } while (I.SymbolFlags.count(I.InitSymbol)); 33 34 I.SymbolFlags[I.InitSymbol] = JITSymbolFlags::MaterializationSideEffectsOnly; 35 } 36 37 static Expected<MaterializationUnit::Interface> 38 getMachOObjectFileSymbolInfo(ExecutionSession &ES, 39 const object::MachOObjectFile &Obj) { 40 MaterializationUnit::Interface I; 41 42 for (auto &Sym : Obj.symbols()) { 43 Expected<uint32_t> SymFlagsOrErr = Sym.getFlags(); 44 if (!SymFlagsOrErr) 45 // TODO: Test this error. 46 return SymFlagsOrErr.takeError(); 47 48 // Skip symbols not defined in this object file. 49 if (*SymFlagsOrErr & object::BasicSymbolRef::SF_Undefined) 50 continue; 51 52 // Skip symbols that are not global. 53 if (!(*SymFlagsOrErr & object::BasicSymbolRef::SF_Global)) 54 continue; 55 56 // Skip symbols that have type SF_File. 57 if (auto SymType = Sym.getType()) { 58 if (*SymType == object::SymbolRef::ST_File) 59 continue; 60 } else 61 return SymType.takeError(); 62 63 auto Name = Sym.getName(); 64 if (!Name) 65 return Name.takeError(); 66 auto SymFlags = JITSymbolFlags::fromObjectSymbol(Sym); 67 if (!SymFlags) 68 return SymFlags.takeError(); 69 70 // Strip the 'exported' flag from MachO linker-private symbols. 71 if (Name->startswith("l")) 72 *SymFlags &= ~JITSymbolFlags::Exported; 73 74 I.SymbolFlags[ES.intern(*Name)] = std::move(*SymFlags); 75 } 76 77 for (auto &Sec : Obj.sections()) { 78 auto SecType = Obj.getSectionType(Sec); 79 if ((SecType & MachO::SECTION_TYPE) == MachO::S_MOD_INIT_FUNC_POINTERS) { 80 addInitSymbol(I, ES, Obj.getFileName()); 81 break; 82 } 83 auto SegName = Obj.getSectionFinalSegmentName(Sec.getRawDataRefImpl()); 84 auto SecName = cantFail(Obj.getSectionName(Sec.getRawDataRefImpl())); 85 if (MachOPlatform::isInitializerSection(SegName, SecName)) { 86 addInitSymbol(I, ES, Obj.getFileName()); 87 break; 88 } 89 } 90 91 return I; 92 } 93 94 static Expected<MaterializationUnit::Interface> 95 getELFObjectFileSymbolInfo(ExecutionSession &ES, 96 const object::ELFObjectFileBase &Obj) { 97 MaterializationUnit::Interface I; 98 99 for (auto &Sym : Obj.symbols()) { 100 Expected<uint32_t> SymFlagsOrErr = Sym.getFlags(); 101 if (!SymFlagsOrErr) 102 // TODO: Test this error. 103 return SymFlagsOrErr.takeError(); 104 105 // Skip symbols not defined in this object file. 106 if (*SymFlagsOrErr & object::BasicSymbolRef::SF_Undefined) 107 continue; 108 109 // Skip symbols that are not global. 110 if (!(*SymFlagsOrErr & object::BasicSymbolRef::SF_Global)) 111 continue; 112 113 // Skip symbols that have type SF_File. 114 if (auto SymType = Sym.getType()) { 115 if (*SymType == object::SymbolRef::ST_File) 116 continue; 117 } else 118 return SymType.takeError(); 119 120 auto Name = Sym.getName(); 121 if (!Name) 122 return Name.takeError(); 123 124 auto SymFlags = JITSymbolFlags::fromObjectSymbol(Sym); 125 if (!SymFlags) 126 return SymFlags.takeError(); 127 128 // ELF STB_GNU_UNIQUE should map to Weak for ORC. 129 if (Sym.getBinding() == ELF::STB_GNU_UNIQUE) 130 *SymFlags |= JITSymbolFlags::Weak; 131 132 I.SymbolFlags[ES.intern(*Name)] = std::move(*SymFlags); 133 } 134 135 SymbolStringPtr InitSymbol; 136 for (auto &Sec : Obj.sections()) { 137 if (auto SecName = Sec.getName()) { 138 if (ELFNixPlatform::isInitializerSection(*SecName)) { 139 addInitSymbol(I, ES, Obj.getFileName()); 140 break; 141 } 142 } 143 } 144 145 return I; 146 } 147 148 Expected<MaterializationUnit::Interface> 149 getGenericObjectFileSymbolInfo(ExecutionSession &ES, 150 const object::ObjectFile &Obj) { 151 MaterializationUnit::Interface I; 152 153 for (auto &Sym : Obj.symbols()) { 154 Expected<uint32_t> SymFlagsOrErr = Sym.getFlags(); 155 if (!SymFlagsOrErr) 156 // TODO: Test this error. 157 return SymFlagsOrErr.takeError(); 158 159 // Skip symbols not defined in this object file. 160 if (*SymFlagsOrErr & object::BasicSymbolRef::SF_Undefined) 161 continue; 162 163 // Skip symbols that are not global. 164 if (!(*SymFlagsOrErr & object::BasicSymbolRef::SF_Global)) 165 continue; 166 167 // Skip symbols that have type SF_File. 168 if (auto SymType = Sym.getType()) { 169 if (*SymType == object::SymbolRef::ST_File) 170 continue; 171 } else 172 return SymType.takeError(); 173 174 auto Name = Sym.getName(); 175 if (!Name) 176 return Name.takeError(); 177 178 auto SymFlags = JITSymbolFlags::fromObjectSymbol(Sym); 179 if (!SymFlags) 180 return SymFlags.takeError(); 181 182 I.SymbolFlags[ES.intern(*Name)] = std::move(*SymFlags); 183 } 184 185 return I; 186 } 187 188 Expected<MaterializationUnit::Interface> 189 getObjectFileInterface(ExecutionSession &ES, MemoryBufferRef ObjBuffer) { 190 auto Obj = object::ObjectFile::createObjectFile(ObjBuffer); 191 192 if (!Obj) 193 return Obj.takeError(); 194 195 if (auto *MachOObj = dyn_cast<object::MachOObjectFile>(Obj->get())) 196 return getMachOObjectFileSymbolInfo(ES, *MachOObj); 197 else if (auto *ELFObj = dyn_cast<object::ELFObjectFileBase>(Obj->get())) 198 return getELFObjectFileSymbolInfo(ES, *ELFObj); 199 200 return getGenericObjectFileSymbolInfo(ES, **Obj); 201 } 202 203 } // End namespace orc. 204 } // End namespace llvm. 205