1 //===- ELFObjectFile.cpp - ELF object file implementation -------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // Part of the ELFObjectFile class implementation. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/Object/ELFObjectFile.h" 15 #include "llvm/Support/ARMBuildAttributes.h" 16 #include "llvm/Support/ARMAttributeParser.h" 17 #include "llvm/Support/MathExtras.h" 18 19 namespace llvm { 20 using namespace object; 21 22 ELFObjectFileBase::ELFObjectFileBase(unsigned int Type, MemoryBufferRef Source) 23 : ObjectFile(Type, Source) {} 24 25 ErrorOr<std::unique_ptr<ObjectFile>> 26 ObjectFile::createELFObjectFile(MemoryBufferRef Obj) { 27 std::pair<unsigned char, unsigned char> Ident = 28 getElfArchType(Obj.getBuffer()); 29 std::size_t MaxAlignment = 30 1ULL << countTrailingZeros(uintptr_t(Obj.getBufferStart())); 31 32 if (MaxAlignment < 2) 33 return object_error::parse_failed; 34 35 std::error_code EC; 36 std::unique_ptr<ObjectFile> R; 37 if (Ident.first == ELF::ELFCLASS32) { 38 if (Ident.second == ELF::ELFDATA2LSB) 39 R.reset(new ELFObjectFile<ELFType<support::little, false>>(Obj, EC)); 40 else if (Ident.second == ELF::ELFDATA2MSB) 41 R.reset(new ELFObjectFile<ELFType<support::big, false>>(Obj, EC)); 42 else 43 return object_error::parse_failed; 44 } else if (Ident.first == ELF::ELFCLASS64) { 45 if (Ident.second == ELF::ELFDATA2LSB) 46 R.reset(new ELFObjectFile<ELFType<support::little, true>>(Obj, EC)); 47 else if (Ident.second == ELF::ELFDATA2MSB) 48 R.reset(new ELFObjectFile<ELFType<support::big, true>>(Obj, EC)); 49 else 50 return object_error::parse_failed; 51 } else { 52 return object_error::parse_failed; 53 } 54 55 if (EC) 56 return EC; 57 return std::move(R); 58 } 59 60 SubtargetFeatures ELFObjectFileBase::getMIPSFeatures() const { 61 SubtargetFeatures Features; 62 unsigned PlatformFlags; 63 getPlatformFlags(PlatformFlags); 64 65 switch (PlatformFlags & ELF::EF_MIPS_ARCH) { 66 case ELF::EF_MIPS_ARCH_1: 67 break; 68 case ELF::EF_MIPS_ARCH_2: 69 Features.AddFeature("mips2"); 70 break; 71 case ELF::EF_MIPS_ARCH_3: 72 Features.AddFeature("mips3"); 73 break; 74 case ELF::EF_MIPS_ARCH_4: 75 Features.AddFeature("mips4"); 76 break; 77 case ELF::EF_MIPS_ARCH_5: 78 Features.AddFeature("mips5"); 79 break; 80 case ELF::EF_MIPS_ARCH_32: 81 Features.AddFeature("mips32"); 82 break; 83 case ELF::EF_MIPS_ARCH_64: 84 Features.AddFeature("mips64"); 85 break; 86 case ELF::EF_MIPS_ARCH_32R2: 87 Features.AddFeature("mips32r2"); 88 break; 89 case ELF::EF_MIPS_ARCH_64R2: 90 Features.AddFeature("mips64r2"); 91 break; 92 case ELF::EF_MIPS_ARCH_32R6: 93 Features.AddFeature("mips32r6"); 94 break; 95 case ELF::EF_MIPS_ARCH_64R6: 96 Features.AddFeature("mips64r6"); 97 break; 98 default: 99 llvm_unreachable("Unknown EF_MIPS_ARCH value"); 100 } 101 102 switch (PlatformFlags & ELF::EF_MIPS_MACH) { 103 case ELF::EF_MIPS_MACH_NONE: 104 // No feature associated with this value. 105 break; 106 case ELF::EF_MIPS_MACH_OCTEON: 107 Features.AddFeature("cnmips"); 108 break; 109 default: 110 llvm_unreachable("Unknown EF_MIPS_ARCH value"); 111 } 112 113 if (PlatformFlags & ELF::EF_MIPS_ARCH_ASE_M16) 114 Features.AddFeature("mips16"); 115 if (PlatformFlags & ELF::EF_MIPS_MICROMIPS) 116 Features.AddFeature("micromips"); 117 118 return Features; 119 } 120 121 SubtargetFeatures ELFObjectFileBase::getARMFeatures() const { 122 SubtargetFeatures Features; 123 ARMAttributeParser Attributes; 124 std::error_code EC = getBuildAttributes(Attributes); 125 if (EC) 126 return SubtargetFeatures(); 127 128 // both ARMv7-M and R have to support thumb hardware div 129 bool isV7 = false; 130 if (Attributes.hasAttribute(ARMBuildAttrs::CPU_arch)) 131 isV7 = Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch) 132 == ARMBuildAttrs::v7; 133 134 if (Attributes.hasAttribute(ARMBuildAttrs::CPU_arch_profile)) { 135 switch(Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch_profile)) { 136 case ARMBuildAttrs::ApplicationProfile: 137 Features.AddFeature("aclass"); 138 break; 139 case ARMBuildAttrs::RealTimeProfile: 140 Features.AddFeature("rclass"); 141 if (isV7) 142 Features.AddFeature("hwdiv"); 143 break; 144 case ARMBuildAttrs::MicroControllerProfile: 145 Features.AddFeature("mclass"); 146 if (isV7) 147 Features.AddFeature("hwdiv"); 148 break; 149 } 150 } 151 152 if (Attributes.hasAttribute(ARMBuildAttrs::THUMB_ISA_use)) { 153 switch(Attributes.getAttributeValue(ARMBuildAttrs::THUMB_ISA_use)) { 154 default: 155 break; 156 case ARMBuildAttrs::Not_Allowed: 157 Features.AddFeature("thumb", false); 158 Features.AddFeature("thumb2", false); 159 break; 160 case ARMBuildAttrs::AllowThumb32: 161 Features.AddFeature("thumb2"); 162 break; 163 } 164 } 165 166 if (Attributes.hasAttribute(ARMBuildAttrs::FP_arch)) { 167 switch(Attributes.getAttributeValue(ARMBuildAttrs::FP_arch)) { 168 default: 169 break; 170 case ARMBuildAttrs::Not_Allowed: 171 Features.AddFeature("vfp2", false); 172 Features.AddFeature("vfp3", false); 173 Features.AddFeature("vfp4", false); 174 break; 175 case ARMBuildAttrs::AllowFPv2: 176 Features.AddFeature("vfp2"); 177 break; 178 case ARMBuildAttrs::AllowFPv3A: 179 case ARMBuildAttrs::AllowFPv3B: 180 Features.AddFeature("vfp3"); 181 break; 182 case ARMBuildAttrs::AllowFPv4A: 183 case ARMBuildAttrs::AllowFPv4B: 184 Features.AddFeature("vfp4"); 185 break; 186 } 187 } 188 189 if (Attributes.hasAttribute(ARMBuildAttrs::Advanced_SIMD_arch)) { 190 switch(Attributes.getAttributeValue(ARMBuildAttrs::Advanced_SIMD_arch)) { 191 default: 192 break; 193 case ARMBuildAttrs::Not_Allowed: 194 Features.AddFeature("neon", false); 195 Features.AddFeature("fp16", false); 196 break; 197 case ARMBuildAttrs::AllowNeon: 198 Features.AddFeature("neon"); 199 break; 200 case ARMBuildAttrs::AllowNeon2: 201 Features.AddFeature("neon"); 202 Features.AddFeature("fp16"); 203 break; 204 } 205 } 206 207 if (Attributes.hasAttribute(ARMBuildAttrs::DIV_use)) { 208 switch(Attributes.getAttributeValue(ARMBuildAttrs::DIV_use)) { 209 default: 210 break; 211 case ARMBuildAttrs::DisallowDIV: 212 Features.AddFeature("hwdiv", false); 213 Features.AddFeature("hwdiv-arm", false); 214 break; 215 case ARMBuildAttrs::AllowDIVExt: 216 Features.AddFeature("hwdiv"); 217 Features.AddFeature("hwdiv-arm"); 218 break; 219 } 220 } 221 222 return Features; 223 } 224 225 SubtargetFeatures ELFObjectFileBase::getFeatures() const { 226 switch (getEMachine()) { 227 case ELF::EM_MIPS: 228 return getMIPSFeatures(); 229 case ELF::EM_ARM: 230 return getARMFeatures(); 231 default: 232 return SubtargetFeatures(); 233 } 234 } 235 236 // FIXME Encode from a tablegen description or target parser. 237 void ELFObjectFileBase::setARMSubArch(Triple &TheTriple) const { 238 if (TheTriple.getSubArch() != Triple::NoSubArch) 239 return; 240 241 ARMAttributeParser Attributes; 242 std::error_code EC = getBuildAttributes(Attributes); 243 if (EC) 244 return; 245 246 std::string Triple; 247 // Default to ARM, but use the triple if it's been set. 248 if (TheTriple.getArch() == Triple::thumb || 249 TheTriple.getArch() == Triple::thumbeb) 250 Triple = "thumb"; 251 else 252 Triple = "arm"; 253 254 if (Attributes.hasAttribute(ARMBuildAttrs::CPU_arch)) { 255 switch(Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch)) { 256 case ARMBuildAttrs::v4: 257 Triple += "v4"; 258 break; 259 case ARMBuildAttrs::v4T: 260 Triple += "v4t"; 261 break; 262 case ARMBuildAttrs::v5T: 263 Triple += "v5t"; 264 break; 265 case ARMBuildAttrs::v5TE: 266 Triple += "v5te"; 267 break; 268 case ARMBuildAttrs::v5TEJ: 269 Triple += "v5tej"; 270 break; 271 case ARMBuildAttrs::v6: 272 Triple += "v6"; 273 break; 274 case ARMBuildAttrs::v6KZ: 275 Triple += "v6kz"; 276 break; 277 case ARMBuildAttrs::v6T2: 278 Triple += "v6t2"; 279 break; 280 case ARMBuildAttrs::v6K: 281 Triple += "v6k"; 282 break; 283 case ARMBuildAttrs::v7: 284 Triple += "v7"; 285 break; 286 case ARMBuildAttrs::v6_M: 287 Triple += "v6m"; 288 break; 289 case ARMBuildAttrs::v6S_M: 290 Triple += "v6sm"; 291 break; 292 case ARMBuildAttrs::v7E_M: 293 Triple += "v7em"; 294 break; 295 } 296 } 297 if (!isLittleEndian()) 298 Triple += "eb"; 299 300 TheTriple.setArchName(Triple); 301 } 302 303 } // end namespace llvm 304