1 //===- XCOFFObjectFile.h - XCOFF object file implementation -----*- C++ -*-===// 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 // This file declares the XCOFFObjectFile class. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_OBJECT_XCOFFOBJECTFILE_H 14 #define LLVM_OBJECT_XCOFFOBJECTFILE_H 15 16 #include "llvm/BinaryFormat/XCOFF.h" 17 #include "llvm/Object/ObjectFile.h" 18 19 namespace llvm { 20 namespace object { 21 22 struct XCOFFFileHeader32 { 23 support::ubig16_t Magic; 24 support::ubig16_t NumberOfSections; 25 26 // Unix time value, value of 0 indicates no timestamp. 27 // Negative values are reserved. 28 support::big32_t TimeStamp; 29 30 support::ubig32_t SymbolTableOffset; // File offset to symbol table. 31 support::big32_t NumberOfSymTableEntries; 32 support::ubig16_t AuxHeaderSize; 33 support::ubig16_t Flags; 34 }; 35 36 struct XCOFFFileHeader64 { 37 support::ubig16_t Magic; 38 support::ubig16_t NumberOfSections; 39 40 // Unix time value, value of 0 indicates no timestamp. 41 // Negative values are reserved. 42 support::big32_t TimeStamp; 43 44 support::ubig64_t SymbolTableOffset; // File offset to symbol table. 45 support::ubig16_t AuxHeaderSize; 46 support::ubig16_t Flags; 47 support::ubig32_t NumberOfSymTableEntries; 48 }; 49 50 struct XCOFFSectionHeader32 { 51 char Name[XCOFF::NameSize]; 52 support::ubig32_t PhysicalAddress; 53 support::ubig32_t VirtualAddress; 54 support::ubig32_t SectionSize; 55 support::ubig32_t FileOffsetToRawData; 56 support::ubig32_t FileOffsetToRelocationInfo; 57 support::ubig32_t FileOffsetToLineNumberInfo; 58 support::ubig16_t NumberOfRelocations; 59 support::ubig16_t NumberOfLineNumbers; 60 support::big32_t Flags; 61 62 StringRef getName() const; 63 }; 64 65 struct XCOFFSectionHeader64 { 66 char Name[XCOFF::NameSize]; 67 support::ubig64_t PhysicalAddress; 68 support::ubig64_t VirtualAddress; 69 support::ubig64_t SectionSize; 70 support::big64_t FileOffsetToRawData; 71 support::big64_t FileOffsetToRelocationInfo; 72 support::big64_t FileOffsetToLineNumberInfo; 73 support::ubig32_t NumberOfRelocations; 74 support::ubig32_t NumberOfLineNumbers; 75 support::big32_t Flags; 76 char Padding[4]; 77 78 StringRef getName() const; 79 }; 80 81 struct XCOFFSymbolEntry { 82 enum { NAME_IN_STR_TBL_MAGIC = 0x0 }; 83 typedef struct { 84 support::big32_t Magic; // Zero indicates name in string table. 85 support::ubig32_t Offset; 86 } NameInStrTblType; 87 88 typedef struct { 89 uint8_t LanguageId; 90 uint8_t CpuTypeId; 91 } CFileLanguageIdAndTypeIdType; 92 93 union { 94 char SymbolName[XCOFF::NameSize]; 95 NameInStrTblType NameInStrTbl; 96 }; 97 98 support::ubig32_t Value; // Symbol value; storage class-dependent. 99 support::big16_t SectionNumber; 100 101 union { 102 support::ubig16_t SymbolType; 103 CFileLanguageIdAndTypeIdType CFileLanguageIdAndTypeId; 104 }; 105 106 XCOFF::StorageClass StorageClass; 107 uint8_t NumberOfAuxEntries; 108 }; 109 110 struct XCOFFStringTable { 111 uint32_t Size; 112 const char *Data; 113 }; 114 115 struct XCOFFCsectAuxEnt32 { 116 support::ubig32_t 117 SectionOrLength; // If the symbol type is XTY_SD or XTY_CM, the csect 118 // length. 119 // If the symbol type is XTY_LD, the symbol table 120 // index of the containing csect. 121 // If the symbol type is XTY_ER, 0. 122 support::ubig32_t ParameterHashIndex; 123 support::ubig16_t TypeChkSectNum; 124 uint8_t SymbolAlignmentAndType; 125 XCOFF::StorageMappingClass StorageMappingClass; 126 support::ubig32_t StabInfoIndex; 127 support::ubig16_t StabSectNum; 128 }; 129 130 struct XCOFFFileAuxEnt { 131 typedef struct { 132 support::big32_t Magic; // Zero indicates name in string table. 133 support::ubig32_t Offset; 134 char NamePad[XCOFF::FileNamePadSize]; 135 } NameInStrTblType; 136 union { 137 char Name[XCOFF::NameSize + XCOFF::FileNamePadSize]; 138 NameInStrTblType NameInStrTbl; 139 }; 140 XCOFF::CFileStringType Type; 141 uint8_t ReservedZeros[2]; 142 uint8_t AuxType; // 64-bit XCOFF file only. 143 }; 144 145 struct XCOFFSectAuxEntForStat { 146 support::ubig32_t SectionLength; 147 support::ubig16_t NumberOfRelocEnt; 148 support::ubig16_t NumberOfLineNum; 149 uint8_t Pad[10]; 150 }; 151 152 struct XCOFFRelocation32 { 153 // Masks for packing/unpacking the r_rsize field of relocations. 154 155 // The msb is used to indicate if the bits being relocated are signed or 156 // unsigned. 157 static constexpr uint8_t XR_SIGN_INDICATOR_MASK = 0x80; 158 159 // The 2nd msb is used to indicate that the binder has replaced/modified the 160 // original instruction. 161 static constexpr uint8_t XR_FIXUP_INDICATOR_MASK = 0x40; 162 163 // The remaining bits specify the bit length of the relocatable reference 164 // minus one. 165 static constexpr uint8_t XR_BIASED_LENGTH_MASK = 0x3f; 166 167 public: 168 support::ubig32_t VirtualAddress; 169 support::ubig32_t SymbolIndex; 170 171 // Packed field, see XR_* masks for details of packing. 172 uint8_t Info; 173 174 XCOFF::RelocationType Type; 175 176 public: 177 bool isRelocationSigned() const; 178 bool isFixupIndicated() const; 179 180 // Returns the number of bits being relocated. 181 uint8_t getRelocatedLength() const; 182 }; 183 184 class XCOFFObjectFile : public ObjectFile { 185 private: 186 const void *FileHeader = nullptr; 187 const void *SectionHeaderTable = nullptr; 188 189 const XCOFFSymbolEntry *SymbolTblPtr = nullptr; 190 XCOFFStringTable StringTable = {0, nullptr}; 191 192 const XCOFFFileHeader32 *fileHeader32() const; 193 const XCOFFFileHeader64 *fileHeader64() const; 194 195 const XCOFFSectionHeader32 *sectionHeaderTable32() const; 196 const XCOFFSectionHeader64 *sectionHeaderTable64() const; 197 198 size_t getFileHeaderSize() const; 199 size_t getSectionHeaderSize() const; 200 201 const XCOFFSectionHeader32 *toSection32(DataRefImpl Ref) const; 202 const XCOFFSectionHeader64 *toSection64(DataRefImpl Ref) const; 203 uintptr_t getSectionHeaderTableAddress() const; 204 uintptr_t getEndOfSymbolTableAddress() const; 205 206 // This returns a pointer to the start of the storage for the name field of 207 // the 32-bit or 64-bit SectionHeader struct. This string is *not* necessarily 208 // null-terminated. 209 const char *getSectionNameInternal(DataRefImpl Sec) const; 210 211 // This function returns string table entry. 212 Expected<StringRef> getStringTableEntry(uint32_t Offset) const; 213 214 static bool isReservedSectionNumber(int16_t SectionNumber); 215 216 // Constructor and "create" factory function. The constructor is only a thin 217 // wrapper around the base constructor. The "create" function fills out the 218 // XCOFF-specific information and performs the error checking along the way. 219 XCOFFObjectFile(unsigned Type, MemoryBufferRef Object); 220 static Expected<std::unique_ptr<XCOFFObjectFile>> create(unsigned Type, 221 MemoryBufferRef MBR); 222 223 // Helper for parsing the StringTable. Returns an 'Error' if parsing failed 224 // and an XCOFFStringTable if parsing succeeded. 225 static Expected<XCOFFStringTable> parseStringTable(const XCOFFObjectFile *Obj, 226 uint64_t Offset); 227 228 // Make a friend so it can call the private 'create' function. 229 friend Expected<std::unique_ptr<ObjectFile>> 230 ObjectFile::createXCOFFObjectFile(MemoryBufferRef Object, unsigned FileType); 231 232 void checkSectionAddress(uintptr_t Addr, uintptr_t TableAddr) const; 233 234 public: 235 // Interface inherited from base classes. 236 void moveSymbolNext(DataRefImpl &Symb) const override; 237 uint32_t getSymbolFlags(DataRefImpl Symb) const override; 238 basic_symbol_iterator symbol_begin() const override; 239 basic_symbol_iterator symbol_end() const override; 240 241 Expected<StringRef> getSymbolName(DataRefImpl Symb) const override; 242 Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const override; 243 uint64_t getSymbolValueImpl(DataRefImpl Symb) const override; 244 uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const override; 245 Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const override; 246 Expected<section_iterator> getSymbolSection(DataRefImpl Symb) const override; 247 248 void moveSectionNext(DataRefImpl &Sec) const override; 249 Expected<StringRef> getSectionName(DataRefImpl Sec) const override; 250 uint64_t getSectionAddress(DataRefImpl Sec) const override; 251 uint64_t getSectionIndex(DataRefImpl Sec) const override; 252 uint64_t getSectionSize(DataRefImpl Sec) const override; 253 Expected<ArrayRef<uint8_t>> 254 getSectionContents(DataRefImpl Sec) const override; 255 uint64_t getSectionAlignment(DataRefImpl Sec) const override; 256 bool isSectionCompressed(DataRefImpl Sec) const override; 257 bool isSectionText(DataRefImpl Sec) const override; 258 bool isSectionData(DataRefImpl Sec) const override; 259 bool isSectionBSS(DataRefImpl Sec) const override; 260 261 bool isSectionVirtual(DataRefImpl Sec) const override; 262 relocation_iterator section_rel_begin(DataRefImpl Sec) const override; 263 relocation_iterator section_rel_end(DataRefImpl Sec) const override; 264 265 void moveRelocationNext(DataRefImpl &Rel) const override; 266 uint64_t getRelocationOffset(DataRefImpl Rel) const override; 267 symbol_iterator getRelocationSymbol(DataRefImpl Rel) const override; 268 uint64_t getRelocationType(DataRefImpl Rel) const override; 269 void getRelocationTypeName(DataRefImpl Rel, 270 SmallVectorImpl<char> &Result) const override; 271 272 section_iterator section_begin() const override; 273 section_iterator section_end() const override; 274 uint8_t getBytesInAddress() const override; 275 StringRef getFileFormatName() const override; 276 Triple::ArchType getArch() const override; 277 SubtargetFeatures getFeatures() const override; 278 Expected<uint64_t> getStartAddress() const override; 279 bool isRelocatableObject() const override; 280 281 // Below here is the non-inherited interface. 282 bool is64Bit() const; 283 284 const XCOFFSymbolEntry *getPointerToSymbolTable() const { 285 assert(!is64Bit() && "Symbol table handling not supported yet."); 286 return SymbolTblPtr; 287 } 288 289 Expected<StringRef> 290 getSymbolSectionName(const XCOFFSymbolEntry *SymEntPtr) const; 291 292 const XCOFFSymbolEntry *toSymbolEntry(DataRefImpl Ref) const; 293 294 // File header related interfaces. 295 uint16_t getMagic() const; 296 uint16_t getNumberOfSections() const; 297 int32_t getTimeStamp() const; 298 299 // Symbol table offset and entry count are handled differently between 300 // XCOFF32 and XCOFF64. 301 uint32_t getSymbolTableOffset32() const; 302 uint64_t getSymbolTableOffset64() const; 303 304 // Note that this value is signed and might return a negative value. Negative 305 // values are reserved for future use. 306 int32_t getRawNumberOfSymbolTableEntries32() const; 307 308 // The sanitized value appropriate to use as an index into the symbol table. 309 uint32_t getLogicalNumberOfSymbolTableEntries32() const; 310 311 uint32_t getNumberOfSymbolTableEntries64() const; 312 uint32_t getSymbolIndex(uintptr_t SymEntPtr) const; 313 Expected<StringRef> getSymbolNameByIndex(uint32_t SymbolTableIndex) const; 314 315 Expected<StringRef> getCFileName(const XCOFFFileAuxEnt *CFileEntPtr) const; 316 uint16_t getOptionalHeaderSize() const; 317 uint16_t getFlags() const; 318 319 // Section header table related interfaces. 320 ArrayRef<XCOFFSectionHeader32> sections32() const; 321 ArrayRef<XCOFFSectionHeader64> sections64() const; 322 323 int32_t getSectionFlags(DataRefImpl Sec) const; 324 Expected<DataRefImpl> getSectionByNum(int16_t Num) const; 325 326 void checkSymbolEntryPointer(uintptr_t SymbolEntPtr) const; 327 328 // Relocation-related interfaces. 329 Expected<uint32_t> 330 getLogicalNumberOfRelocationEntries(const XCOFFSectionHeader32 &Sec) const; 331 332 Expected<ArrayRef<XCOFFRelocation32>> 333 relocations(const XCOFFSectionHeader32 &) const; 334 }; // XCOFFObjectFile 335 336 class XCOFFSymbolRef { 337 const DataRefImpl SymEntDataRef; 338 const XCOFFObjectFile *const OwningObjectPtr; 339 340 public: 341 XCOFFSymbolRef(DataRefImpl SymEntDataRef, 342 const XCOFFObjectFile *OwningObjectPtr) 343 : SymEntDataRef(SymEntDataRef), OwningObjectPtr(OwningObjectPtr){}; 344 345 XCOFF::StorageClass getStorageClass() const; 346 uint8_t getNumberOfAuxEntries() const; 347 const XCOFFCsectAuxEnt32 *getXCOFFCsectAuxEnt32() const; 348 uint16_t getType() const; 349 int16_t getSectionNumber() const; 350 351 bool hasCsectAuxEnt() const; 352 bool isFunction() const; 353 }; 354 355 } // namespace object 356 } // namespace llvm 357 358 #endif // LLVM_OBJECT_XCOFFOBJECTFILE_H 359