1 //===- GNUInfo.h ----------------------------------------------------------===// 2 // 3 // The MCLinker Project 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 #ifndef MCLD_TARGET_GNUINFO_H_ 10 #define MCLD_TARGET_GNUINFO_H_ 11 #include <llvm/ADT/Triple.h> 12 #include <llvm/Support/ELF.h> 13 14 namespace mcld { 15 16 /** \class GNUInfo 17 * \brief GNUInfo records ELF-dependent and target-dependnet data fields 18 */ 19 class GNUInfo { 20 public: 21 explicit GNUInfo(const llvm::Triple& pTriple); 22 ~GNUInfo()23 virtual ~GNUInfo() {} 24 25 /// ELFVersion - the value of e_ident[EI_VERSION] ELFVersion()26 virtual uint8_t ELFVersion() const { return llvm::ELF::EV_CURRENT; } 27 28 /// The return value of machine() it the same as e_machine in the ELF header 29 virtual uint32_t machine() const = 0; 30 31 /// OSABI - the value of e_ident[EI_OSABI] 32 uint8_t OSABI() const; 33 34 /// ABIVersion - the value of e_ident[EI_ABIVRESION] ABIVersion()35 virtual uint8_t ABIVersion() const { return 0x0; } 36 37 /// defaultTextSegmentAddr - target should specify its own default start 38 /// address of the text segment. esp. for exec. defaultTextSegmentAddr()39 virtual uint64_t defaultTextSegmentAddr() const { return 0x0; } 40 41 /// flags - the value of ElfXX_Ehdr::e_flags 42 virtual uint64_t flags() const = 0; 43 44 /// entry - the symbol name of the entry point entry()45 virtual const char* entry() const { return "_start"; } 46 47 /// dyld - the name of the default dynamic linker 48 /// target may override this function if needed. dyld()49 virtual const char* dyld() const { return "/usr/lib/libc.so.1"; } 50 51 /// isDefaultExecStack - target should specify whether the stack is default 52 /// executable. If target favors another choice, please override this function isDefaultExecStack()53 virtual bool isDefaultExecStack() const { return true; } 54 55 /// commonPageSize - the common page size of the target machine, and we set it 56 /// to 4K here. If target favors the different size, please override this commonPageSize()57 virtual uint64_t commonPageSize() const { return 0x1000; } 58 59 /// abiPageSize - the abi page size of the target machine, and we set it to 4K 60 /// here. If target favors the different size, please override this function abiPageSize()61 virtual uint64_t abiPageSize() const { return 0x1000; } 62 63 /// stubGroupSize - the default group size to place stubs between sections. stubGroupSize()64 virtual unsigned stubGroupSize() const { return 0x10000; } 65 66 protected: 67 const llvm::Triple& m_Triple; 68 }; 69 70 } // namespace mcld 71 72 #endif // MCLD_TARGET_GNUINFO_H_ 73