X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FMachOWriter.h;h=2e7e67d2db7298273c034409e4b51a8d40a343d7;hb=3b131d7cc4dc4bbb329c136705b37dc255995fbd;hp=0492c9e93c5e09984f88ff3191a6d274f1afa96f;hpb=ca0ed744852a7d9625572fbb793f65e81225a3e8;p=oota-llvm.git diff --git a/lib/CodeGen/MachOWriter.h b/lib/CodeGen/MachOWriter.h index 0492c9e93c5..2e7e67d2db7 100644 --- a/lib/CodeGen/MachOWriter.h +++ b/lib/CodeGen/MachOWriter.h @@ -2,8 +2,8 @@ // // The LLVM Compiler Infrastructure // -// This file was developed by Nate Begeman and is distributed under the -// University of Illinois Open Source License. See LICENSE.TXT for details. +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // @@ -14,612 +14,73 @@ #ifndef MACHOWRITER_H #define MACHOWRITER_H -#include "llvm/Constants.h" -#include "llvm/DerivedTypes.h" #include "llvm/CodeGen/MachineFunctionPass.h" -#include "llvm/CodeGen/MachineRelocation.h" -#include "llvm/Target/TargetData.h" #include "llvm/Target/TargetMachine.h" -#include "llvm/Target/TargetMachOWriterInfo.h" namespace llvm { class GlobalVariable; class Mangler; - class MachineCodeEmitter; - class MachOCodeEmitter; - class OutputBuffer; - - /// MachOSym - This struct contains information about each symbol that is - /// added to logical symbol table for the module. This is eventually - /// turned into a real symbol table in the file. - struct MachOSym { - const GlobalValue *GV; // The global value this corresponds to. - std::string GVName; // The mangled name of the global value. - uint32_t n_strx; // index into the string table - uint8_t n_type; // type flag - uint8_t n_sect; // section number or NO_SECT - int16_t n_desc; // see - uint64_t n_value; // value for this symbol (or stab offset) - - // Constants for the n_sect field - // see - enum { NO_SECT = 0 }; // symbol is not in any section - - // Constants for the n_type field - // see - enum { N_UNDF = 0x0, // undefined, n_sect == NO_SECT - N_ABS = 0x2, // absolute, n_sect == NO_SECT - N_SECT = 0xe, // defined in section number n_sect - N_PBUD = 0xc, // prebound undefined (defined in a dylib) - N_INDR = 0xa // indirect - }; - // The following bits are OR'd into the types above. For example, a type - // of 0x0f would be an external N_SECT symbol (0x0e | 0x01). - enum { N_EXT = 0x01, // external symbol bit - N_PEXT = 0x10 // private external symbol bit - }; - - // Constants for the n_desc field - // see - enum { REFERENCE_FLAG_UNDEFINED_NON_LAZY = 0, - REFERENCE_FLAG_UNDEFINED_LAZY = 1, - REFERENCE_FLAG_DEFINED = 2, - REFERENCE_FLAG_PRIVATE_DEFINED = 3, - REFERENCE_FLAG_PRIVATE_UNDEFINED_NON_LAZY = 4, - REFERENCE_FLAG_PRIVATE_UNDEFINED_LAZY = 5 - }; - enum { N_NO_DEAD_STRIP = 0x0020, // symbol is not to be dead stripped - N_WEAK_REF = 0x0040, // symbol is weak referenced - N_WEAK_DEF = 0x0080 // coalesced symbol is a weak definition - }; - - MachOSym(const GlobalValue *gv, std::string name, uint8_t sect, - TargetMachine &TM); - }; - + class MCCodeEmitter; + class MCContext; + class MCStreamer; + /// MachOWriter - This class implements the common target-independent code for /// writing Mach-O files. Targets should derive a class from this to /// parameterize the output format. /// class MachOWriter : public MachineFunctionPass { - friend class MachOCodeEmitter; - public: static char ID; - MachineCodeEmitter &getMachineCodeEmitter() const { - return *(MachineCodeEmitter*)MCE; - } - - MachOWriter(std::ostream &O, TargetMachine &TM); - virtual ~MachOWriter(); - - virtual const char *getPassName() const { - return "Mach-O Writer"; - } - typedef std::vector DataBuffer; protected: /// Output stream to send the resultant object file to. /// - std::ostream &O; + formatted_raw_ostream &O; /// Target machine description. /// TargetMachine &TM; - /// Mang - The object used to perform name mangling for this module. + /// Target Asm Printer information. /// - Mangler *Mang; + const MCAsmInfo *MAI; - /// MCE - The MachineCodeEmitter object that we are exposing to emit machine + /// MCCE - The MCCodeEmitter object that we are exposing to emit machine /// code for functions to the .o file. - MachOCodeEmitter *MCE; - - /// is64Bit/isLittleEndian - This information is inferred from the target - /// machine directly, indicating what header values and flags to set. - bool is64Bit, isLittleEndian; - + MCCodeEmitter *MCCE; + + /// OutContext - This is the context for the output file that we are + /// streaming. This owns all of the global MC-related objects for the + /// generated translation unit. + MCContext &OutContext; + + /// OutStreamer - This is the MCStreamer object for the file we are + /// generating. This contains the transient state for the current + /// translation unit that we are generating (such as the current section + /// etc). + MCStreamer &OutStreamer; + + /// Name-mangler for global names. + /// + Mangler *Mang; + /// doInitialization - Emit the file header and all of the global variables /// for the module to the Mach-O file. bool doInitialization(Module &M); - bool runOnMachineFunction(MachineFunction &MF); - /// doFinalization - Now that the module has been completely processed, emit /// the Mach-O file to 'O'. bool doFinalization(Module &M); - /// MachOHeader - This struct contains the header information about a - /// specific architecture type/subtype pair that is emitted to the file. - struct MachOHeader { - uint32_t magic; // mach magic number identifier - uint32_t filetype; // type of file - uint32_t ncmds; // number of load commands - uint32_t sizeofcmds; // the size of all the load commands - uint32_t flags; // flags - uint32_t reserved; // 64-bit only - - /// HeaderData - The actual data for the header which we are building - /// up for emission to the file. - DataBuffer HeaderData; - - // Constants for the filetype field - // see for additional info on the various types - enum { MH_OBJECT = 1, // relocatable object file - MH_EXECUTE = 2, // demand paged executable file - MH_FVMLIB = 3, // fixed VM shared library file - MH_CORE = 4, // core file - MH_PRELOAD = 5, // preloaded executable file - MH_DYLIB = 6, // dynamically bound shared library - MH_DYLINKER = 7, // dynamic link editor - MH_BUNDLE = 8, // dynamically bound bundle file - MH_DYLIB_STUB = 9, // shared library stub for static linking only - MH_DSYM = 10 // companion file wiht only debug sections - }; - - // Constants for the flags field - enum { MH_NOUNDEFS = 1 << 0, - // the object file has no undefined references - MH_INCRLINK = 1 << 1, - // the object file is the output of an incremental link against - // a base file and cannot be link edited again - MH_DYLDLINK = 1 << 2, - // the object file is input for the dynamic linker and cannot be - // statically link edited again. - MH_BINDATLOAD = 1 << 3, - // the object file's undefined references are bound by the - // dynamic linker when loaded. - MH_PREBOUND = 1 << 4, - // the file has its dynamic undefined references prebound - MH_SPLIT_SEGS = 1 << 5, - // the file has its read-only and read-write segments split - // see - MH_LAZY_INIT = 1 << 6, - // the shared library init routine is to be run lazily via - // catching memory faults to its writable segments (obsolete) - MH_TWOLEVEL = 1 << 7, - // the image is using two-level namespace bindings - MH_FORCE_FLAT = 1 << 8, - // the executable is forcing all images to use flat namespace - // bindings. - MH_NOMULTIDEFS = 1 << 8, - // this umbrella guarantees no multiple definitions of symbols - // in its sub-images so the two-level namespace hints can - // always be used. - MH_NOFIXPREBINDING = 1 << 10, - // do not have dyld notify the prebidning agent about this - // executable. - MH_PREBINDABLE = 1 << 11, - // the binary is not prebound but can have its prebinding - // redone. only used when MH_PREBOUND is not set. - MH_ALLMODSBOUND = 1 << 12, - // indicates that this binary binds to all two-level namespace - // modules of its dependent libraries. Only used when - // MH_PREBINDABLE and MH_TWOLEVEL are both set. - MH_SUBSECTIONS_VIA_SYMBOLS = 1 << 13, - // safe to divide up the sections into sub-sections via symbols - // for dead code stripping. - MH_CANONICAL = 1 << 14, - // the binary has been canonicalized via the unprebind operation - MH_WEAK_DEFINES = 1 << 15, - // the final linked image contains external weak symbols - MH_BINDS_TO_WEAK = 1 << 16, - // the final linked image uses weak symbols - MH_ALLOW_STACK_EXECUTION = 1 << 17 - // When this bit is set, all stacks in the task will be given - // stack execution privilege. Only used in MH_EXECUTE filetype - }; - - MachOHeader() : magic(0), filetype(0), ncmds(0), sizeofcmds(0), flags(0), - reserved(0) { } - - /// cmdSize - This routine returns the size of the MachOSection as written - /// to disk, depending on whether the destination is a 64 bit Mach-O file. - unsigned cmdSize(bool is64Bit) const { - if (is64Bit) - return 8 * sizeof(uint32_t); - else - return 7 * sizeof(uint32_t); - } - - /// setMagic - This routine sets the appropriate value for the 'magic' - /// field based on pointer size and endianness. - void setMagic(bool isLittleEndian, bool is64Bit) { - if (isLittleEndian) - if (is64Bit) magic = 0xcffaedfe; - else magic = 0xcefaedfe; - else - if (is64Bit) magic = 0xfeedfacf; - else magic = 0xfeedface; - } - }; - - /// Header - An instance of MachOHeader that we will update while we build - /// the file, and then emit during finalization. - MachOHeader Header; - - /// MachOSegment - This struct contains the necessary information to - /// emit the load commands for each section in the file. - struct MachOSegment { - uint32_t cmd; // LC_SEGMENT or LC_SEGMENT_64 - uint32_t cmdsize; // Total size of this struct and section commands - std::string segname; // segment name - uint64_t vmaddr; // address of this segment - uint64_t vmsize; // size of this segment, may be larger than filesize - uint64_t fileoff; // offset in file - uint64_t filesize; // amount to read from file - uint32_t maxprot; // maximum VM protection - uint32_t initprot; // initial VM protection - uint32_t nsects; // number of sections in this segment - uint32_t flags; // flags - - // The following constants are getting pulled in by one of the - // system headers, which creates a neat clash with the enum. -#if !defined(VM_PROT_NONE) -#define VM_PROT_NONE 0x00 -#endif -#if !defined(VM_PROT_READ) -#define VM_PROT_READ 0x01 -#endif -#if !defined(VM_PROT_WRITE) -#define VM_PROT_WRITE 0x02 -#endif -#if !defined(VM_PROT_EXECUTE) -#define VM_PROT_EXECUTE 0x04 -#endif -#if !defined(VM_PROT_ALL) -#define VM_PROT_ALL 0x07 -#endif - - // Constants for the vm protection fields - // see - enum { SEG_VM_PROT_NONE = VM_PROT_NONE, - SEG_VM_PROT_READ = VM_PROT_READ, // read permission - SEG_VM_PROT_WRITE = VM_PROT_WRITE, // write permission - SEG_VM_PROT_EXECUTE = VM_PROT_EXECUTE, - SEG_VM_PROT_ALL = VM_PROT_ALL - }; - - // Constants for the cmd field - // see - enum { LC_SEGMENT = 0x01, // segment of this file to be mapped - LC_SEGMENT_64 = 0x19 // 64-bit segment of this file to be mapped - }; - - /// cmdSize - This routine returns the size of the MachOSection as written - /// to disk, depending on whether the destination is a 64 bit Mach-O file. - unsigned cmdSize(bool is64Bit) const { - if (is64Bit) - return 6 * sizeof(uint32_t) + 4 * sizeof(uint64_t) + 16; - else - return 10 * sizeof(uint32_t) + 16; // addresses only 32 bits - } - - MachOSegment(const std::string &seg, bool is64Bit) - : cmd(is64Bit ? LC_SEGMENT_64 : LC_SEGMENT), cmdsize(0), segname(seg), - vmaddr(0), vmsize(0), fileoff(0), filesize(0), maxprot(VM_PROT_ALL), - initprot(VM_PROT_ALL), nsects(0), flags(0) { } - }; - - /// MachOSection - This struct contains information about each section in a - /// particular segment that is emitted to the file. This is eventually - /// turned into the SectionCommand in the load command for a particlar - /// segment. - struct MachOSection { - std::string sectname; // name of this section, - std::string segname; // segment this section goes in - uint64_t addr; // memory address of this section - uint64_t size; // size in bytes of this section - uint32_t offset; // file offset of this section - uint32_t align; // section alignment (power of 2) - uint32_t reloff; // file offset of relocation entries - uint32_t nreloc; // number of relocation entries - uint32_t flags; // flags (section type and attributes) - uint32_t reserved1; // reserved (for offset or index) - uint32_t reserved2; // reserved (for count or sizeof) - uint32_t reserved3; // reserved (64 bit only) - - /// A unique number for this section, which will be used to match symbols - /// to the correct section. - uint32_t Index; - - /// SectionData - The actual data for this section which we are building - /// up for emission to the file. - DataBuffer SectionData; - - /// RelocBuffer - A buffer to hold the mach-o relocations before we write - /// them out at the appropriate location in the file. - DataBuffer RelocBuffer; - - /// Relocations - The relocations that we have encountered so far in this - /// section that we will need to convert to MachORelocation entries when - /// the file is written. - std::vector Relocations; - - // Constants for the section types (low 8 bits of flags field) - // see - enum { S_REGULAR = 0, - // regular section - S_ZEROFILL = 1, - // zero fill on demand section - S_CSTRING_LITERALS = 2, - // section with only literal C strings - S_4BYTE_LITERALS = 3, - // section with only 4 byte literals - S_8BYTE_LITERALS = 4, - // section with only 8 byte literals - S_LITERAL_POINTERS = 5, - // section with only pointers to literals - S_NON_LAZY_SYMBOL_POINTERS = 6, - // section with only non-lazy symbol pointers - S_LAZY_SYMBOL_POINTERS = 7, - // section with only lazy symbol pointers - S_SYMBOL_STUBS = 8, - // section with only symbol stubs - // byte size of stub in the reserved2 field - S_MOD_INIT_FUNC_POINTERS = 9, - // section with only function pointers for initialization - S_MOD_TERM_FUNC_POINTERS = 10, - // section with only function pointers for termination - S_COALESCED = 11, - // section contains symbols that are coalesced - S_GB_ZEROFILL = 12, - // zero fill on demand section (that can be larger than 4GB) - S_INTERPOSING = 13, - // section with only pairs of function pointers for interposing - S_16BYTE_LITERALS = 14 - // section with only 16 byte literals - }; - - // Constants for the section flags (high 24 bits of flags field) - // see - enum { S_ATTR_PURE_INSTRUCTIONS = 1 << 31, - // section contains only true machine instructions - S_ATTR_NO_TOC = 1 << 30, - // section contains coalesced symbols that are not to be in a - // ranlib table of contents - S_ATTR_STRIP_STATIC_SYMS = 1 << 29, - // ok to strip static symbols in this section in files with the - // MY_DYLDLINK flag - S_ATTR_NO_DEAD_STRIP = 1 << 28, - // no dead stripping - S_ATTR_LIVE_SUPPORT = 1 << 27, - // blocks are live if they reference live blocks - S_ATTR_SELF_MODIFYING_CODE = 1 << 26, - // used with i386 code stubs written on by dyld - S_ATTR_DEBUG = 1 << 25, - // a debug section - S_ATTR_SOME_INSTRUCTIONS = 1 << 10, - // section contains some machine instructions - S_ATTR_EXT_RELOC = 1 << 9, - // section has external relocation entries - S_ATTR_LOC_RELOC = 1 << 8 - // section has local relocation entries - }; - - /// cmdSize - This routine returns the size of the MachOSection as written - /// to disk, depending on whether the destination is a 64 bit Mach-O file. - unsigned cmdSize(bool is64Bit) const { - if (is64Bit) - return 7 * sizeof(uint32_t) + 2 * sizeof(uint64_t) + 32; - else - return 9 * sizeof(uint32_t) + 32; // addresses only 32 bits - } - - MachOSection(const std::string &seg, const std::string §) - : sectname(sect), segname(seg), addr(0), size(0), offset(0), align(2), - reloff(0), nreloc(0), flags(0), reserved1(0), reserved2(0), - reserved3(0) { } - }; - - private: - - /// SectionList - This is the list of sections that we have emitted to the - /// file. Once the file has been completely built, the segment load command - /// SectionCommands are constructed from this info. - std::vector SectionList; - - /// SectionLookup - This is a mapping from section name to SectionList entry - std::map SectionLookup; - - /// GVSection - This is a mapping from a GlobalValue to a MachOSection, - /// to aid in emitting relocations. - std::map GVSection; - - /// GVOffset - This is a mapping from a GlobalValue to an offset from the - /// start of the section in which the GV resides, to aid in emitting - /// relocations. - std::map GVOffset; - - /// getSection - Return the section with the specified name, creating a new - /// section if one does not already exist. - MachOSection *getSection(const std::string &seg, const std::string §, - unsigned Flags = 0) { - MachOSection *MOS = SectionLookup[seg+sect]; - if (MOS) return MOS; - - MOS = new MachOSection(seg, sect); - SectionList.push_back(MOS); - MOS->Index = SectionList.size(); - MOS->flags = MachOSection::S_REGULAR | Flags; - SectionLookup[seg+sect] = MOS; - return MOS; - } - MachOSection *getTextSection(bool isCode = true) { - if (isCode) - return getSection("__TEXT", "__text", - MachOSection::S_ATTR_PURE_INSTRUCTIONS | - MachOSection::S_ATTR_SOME_INSTRUCTIONS); - else - return getSection("__TEXT", "__text"); - } - MachOSection *getBSSSection() { - return getSection("__DATA", "__bss", MachOSection::S_ZEROFILL); - } - MachOSection *getDataSection() { - return getSection("__DATA", "__data"); - } - MachOSection *getConstSection(Constant *C) { - const ConstantArray *CVA = dyn_cast(C); - if (CVA && CVA->isCString()) - return getSection("__TEXT", "__cstring", - MachOSection::S_CSTRING_LITERALS); - - const Type *Ty = C->getType(); - if (Ty->isPrimitiveType() || Ty->isInteger()) { - unsigned Size = TM.getTargetData()->getABITypeSize(Ty); - switch(Size) { - default: break; // Fall through to __TEXT,__const - case 4: - return getSection("__TEXT", "__literal4", - MachOSection::S_4BYTE_LITERALS); - case 8: - return getSection("__TEXT", "__literal8", - MachOSection::S_8BYTE_LITERALS); - case 16: - return getSection("__TEXT", "__literal16", - MachOSection::S_16BYTE_LITERALS); - } - } - return getSection("__TEXT", "__const"); - } - MachOSection *getJumpTableSection() { - if (TM.getRelocationModel() == Reloc::PIC_) - return getTextSection(false); - else - return getSection("__TEXT", "__const"); - } - - /// MachOSymTab - This struct contains information about the offsets and - /// size of symbol table information. - /// segment. - struct MachOSymTab { - uint32_t cmd; // LC_SYMTAB - uint32_t cmdsize; // sizeof( MachOSymTab ) - uint32_t symoff; // symbol table offset - uint32_t nsyms; // number of symbol table entries - uint32_t stroff; // string table offset - uint32_t strsize; // string table size in bytes - - // Constants for the cmd field - // see - enum { LC_SYMTAB = 0x02 // link-edit stab symbol table info - }; - - MachOSymTab() : cmd(LC_SYMTAB), cmdsize(6 * sizeof(uint32_t)), symoff(0), - nsyms(0), stroff(0), strsize(0) { } - }; - - /// MachOSymTab - This struct contains information about the offsets and - /// size of symbol table information. - /// segment. - struct MachODySymTab { - uint32_t cmd; // LC_DYSYMTAB - uint32_t cmdsize; // sizeof( MachODySymTab ) - uint32_t ilocalsym; // index to local symbols - uint32_t nlocalsym; // number of local symbols - uint32_t iextdefsym; // index to externally defined symbols - uint32_t nextdefsym; // number of externally defined symbols - uint32_t iundefsym; // index to undefined symbols - uint32_t nundefsym; // number of undefined symbols - uint32_t tocoff; // file offset to table of contents - uint32_t ntoc; // number of entries in table of contents - uint32_t modtaboff; // file offset to module table - uint32_t nmodtab; // number of module table entries - uint32_t extrefsymoff; // offset to referenced symbol table - uint32_t nextrefsyms; // number of referenced symbol table entries - uint32_t indirectsymoff; // file offset to the indirect symbol table - uint32_t nindirectsyms; // number of indirect symbol table entries - uint32_t extreloff; // offset to external relocation entries - uint32_t nextrel; // number of external relocation entries - uint32_t locreloff; // offset to local relocation entries - uint32_t nlocrel; // number of local relocation entries - - // Constants for the cmd field - // see - enum { LC_DYSYMTAB = 0x0B // dynamic link-edit symbol table info - }; - - MachODySymTab() : cmd(LC_DYSYMTAB), cmdsize(20 * sizeof(uint32_t)), - ilocalsym(0), nlocalsym(0), iextdefsym(0), nextdefsym(0), - iundefsym(0), nundefsym(0), tocoff(0), ntoc(0), modtaboff(0), - nmodtab(0), extrefsymoff(0), nextrefsyms(0), indirectsymoff(0), - nindirectsyms(0), extreloff(0), nextrel(0), locreloff(0), nlocrel(0) { } - }; - - /// SymTab - The "stab" style symbol table information - MachOSymTab SymTab; - /// DySymTab - symbol table info for the dynamic link editor - MachODySymTab DySymTab; - - struct MachOSymCmp { - // FIXME: this does not appear to be sorting 'f' after 'F' - bool operator()(const MachOSym &LHS, const MachOSym &RHS) { - return LHS.GVName < RHS.GVName; - } - }; - - /// PartitionByLocal - Simple boolean predicate that returns true if Sym is - /// a local symbol rather than an external symbol. - static bool PartitionByLocal(const MachOSym &Sym); - - /// PartitionByDefined - Simple boolean predicate that returns true if Sym - /// is defined in this module. - static bool PartitionByDefined(const MachOSym &Sym); - - protected: - - /// SymbolTable - This is the list of symbols we have emitted to the file. - /// This actually gets rearranged before emission to the file (to put the - /// local symbols first in the list). - std::vector SymbolTable; - - /// SymT - A buffer to hold the symbol table before we write it out at the - /// appropriate location in the file. - DataBuffer SymT; - - /// StrT - A buffer to hold the string table before we write it out at the - /// appropriate location in the file. - DataBuffer StrT; + bool runOnMachineFunction(MachineFunction &MF); - /// PendingSyms - This is a list of externally defined symbols that we have - /// been asked to emit, but have not seen a reference to. When a reference - /// is seen, the symbol will move from this list to the SymbolTable. - std::vector PendingGlobals; + public: + explicit MachOWriter(formatted_raw_ostream &O, TargetMachine &TM, + const MCAsmInfo *T, MCCodeEmitter *MCE); - /// DynamicSymbolTable - This is just a vector of indices into - /// SymbolTable to aid in emitting the DYSYMTAB load command. - std::vector DynamicSymbolTable; + virtual ~MachOWriter(); - static void InitMem(const Constant *C, void *Addr, intptr_t Offset, - const TargetData *TD, - std::vector &MRs); - - private: - void AddSymbolToSection(MachOSection *MOS, GlobalVariable *GV); - void EmitGlobal(GlobalVariable *GV); - void EmitHeaderAndLoadCommands(); - void EmitSections(); - void BufferSymbolAndStringTable(); - void CalculateRelocations(MachOSection &MOS); - - MachineRelocation GetJTRelocation(unsigned Offset, - MachineBasicBlock *MBB) const { - return TM.getMachOWriterInfo()->GetJTRelocation(Offset, MBB); - } - - /// GetTargetRelocation - Returns the number of relocations. - unsigned GetTargetRelocation(MachineRelocation &MR, - unsigned FromIdx, - unsigned ToAddr, - unsigned ToIndex, - OutputBuffer &RelocOut, - OutputBuffer &SecOut, - bool Scattered, - bool Extern) { - return TM.getMachOWriterInfo()->GetTargetRelocation(MR, FromIdx, ToAddr, - ToIndex, RelocOut, - SecOut, Scattered, - Extern); + virtual const char *getPassName() const { + return "Mach-O Writer"; } }; }