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 InternedName = ES.intern(*Name); 67 auto SymFlags = JITSymbolFlags::fromObjectSymbol(Sym); 68 if (!SymFlags) 69 return SymFlags.takeError(); 70 71 // Strip the 'exported' flag from MachO linker-private symbols. 72 if (Name->startswith("l")) 73 *SymFlags &= ~JITSymbolFlags::Exported; 74 75 I.SymbolFlags[InternedName] = std::move(*SymFlags); 76 } 77 78 for (auto &Sec : Obj.sections()) { 79 auto SecType = Obj.getSectionType(Sec); 80 if ((SecType & MachO::SECTION_TYPE) == MachO::S_MOD_INIT_FUNC_POINTERS) { 81 addInitSymbol(I, ES, Obj.getFileName()); 82 break; 83 } 84 auto SegName = Obj.getSectionFinalSegmentName(Sec.getRawDataRefImpl()); 85 auto SecName = cantFail(Obj.getSectionName(Sec.getRawDataRefImpl())); 86 if (MachOPlatform::isInitializerSection(SegName, SecName)) { 87 addInitSymbol(I, ES, Obj.getFileName()); 88 break; 89 } 90 } 91 92 return I; 93 } 94 95 static Expected<MaterializationUnit::Interface> 96 getELFObjectFileSymbolInfo(ExecutionSession &ES, 97 const object::ELFObjectFileBase &Obj) { 98 MaterializationUnit::Interface I; 99 100 for (auto &Sym : Obj.symbols()) { 101 Expected<uint32_t> SymFlagsOrErr = Sym.getFlags(); 102 if (!SymFlagsOrErr) 103 // TODO: Test this error. 104 return SymFlagsOrErr.takeError(); 105 106 // Skip symbols not defined in this object file. 107 if (*SymFlagsOrErr & object::BasicSymbolRef::SF_Undefined) 108 continue; 109 110 // Skip symbols that are not global. 111 if (!(*SymFlagsOrErr & object::BasicSymbolRef::SF_Global)) 112 continue; 113 114 // Skip symbols that have type SF_File. 115 if (auto SymType = Sym.getType()) { 116 if (*SymType == object::SymbolRef::ST_File) 117 continue; 118 } else 119 return SymType.takeError(); 120 121 auto Name = Sym.getName(); 122 if (!Name) 123 return Name.takeError(); 124 auto InternedName = ES.intern(*Name); 125 auto SymFlags = JITSymbolFlags::fromObjectSymbol(Sym); 126 if (!SymFlags) 127 return SymFlags.takeError(); 128 129 // ELF STB_GNU_UNIQUE should map to Weak for ORC. 130 if (Sym.getBinding() == ELF::STB_GNU_UNIQUE) 131 *SymFlags |= JITSymbolFlags::Weak; 132 133 I.SymbolFlags[InternedName] = std::move(*SymFlags); 134 } 135 136 SymbolStringPtr InitSymbol; 137 for (auto &Sec : Obj.sections()) { 138 if (auto SecName = Sec.getName()) { 139 if (ELFNixPlatform::isInitializerSection(*SecName)) { 140 addInitSymbol(I, ES, Obj.getFileName()); 141 break; 142 } 143 } 144 } 145 146 return I; 147 } 148 149 Expected<MaterializationUnit::Interface> 150 getGenericObjectFileSymbolInfo(ExecutionSession &ES, 151 const object::ObjectFile &Obj) { 152 MaterializationUnit::Interface I; 153 154 for (auto &Sym : Obj.symbols()) { 155 Expected<uint32_t> SymFlagsOrErr = Sym.getFlags(); 156 if (!SymFlagsOrErr) 157 // TODO: Test this error. 158 return SymFlagsOrErr.takeError(); 159 160 // Skip symbols not defined in this object file. 161 if (*SymFlagsOrErr & object::BasicSymbolRef::SF_Undefined) 162 continue; 163 164 // Skip symbols that are not global. 165 if (!(*SymFlagsOrErr & object::BasicSymbolRef::SF_Global)) 166 continue; 167 168 // Skip symbols that have type SF_File. 169 if (auto SymType = Sym.getType()) { 170 if (*SymType == object::SymbolRef::ST_File) 171 continue; 172 } else 173 return SymType.takeError(); 174 175 auto Name = Sym.getName(); 176 if (!Name) 177 return Name.takeError(); 178 auto InternedName = ES.intern(*Name); 179 auto SymFlags = JITSymbolFlags::fromObjectSymbol(Sym); 180 if (!SymFlags) 181 return SymFlags.takeError(); 182 183 I.SymbolFlags[InternedName] = std::move(*SymFlags); 184 } 185 186 return I; 187 } 188 189 Expected<MaterializationUnit::Interface> 190 getObjectFileInterface(ExecutionSession &ES, MemoryBufferRef ObjBuffer) { 191 auto Obj = object::ObjectFile::createObjectFile(ObjBuffer); 192 193 if (!Obj) 194 return Obj.takeError(); 195 196 if (auto *MachOObj = dyn_cast<object::MachOObjectFile>(Obj->get())) 197 return getMachOObjectFileSymbolInfo(ES, *MachOObj); 198 else if (auto *ELFObj = dyn_cast<object::ELFObjectFileBase>(Obj->get())) 199 return getELFObjectFileSymbolInfo(ES, *ELFObj); 200 201 return getGenericObjectFileSymbolInfo(ES, **Obj); 202 } 203 204 } // End namespace orc. 205 } // End namespace llvm. 206