| //=== MachO.h - Mach-O structures and constants -----------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines MachO . |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef MACHO_H |
| #define MACHO_H |
| |
| #include "llvm/CodeGen/BinaryObject.h" |
| #include <string> |
| #include <vector> |
| |
| namespace llvm { |
| |
| class GlobalValue; |
| class TargetAsmInfo; |
| |
| /// 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 <mach-o/stab.h> |
| uint64_t n_value; // value for this symbol (or stab offset) |
| |
| // Constants for the n_sect field |
| // see <mach-o/nlist.h> |
| enum { NO_SECT = 0 }; // symbol is not in any section |
| |
| // Constants for the n_type field |
| // see <mach-o/nlist.h> |
| 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 <mach-o/loader.h> |
| 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, |
| const TargetAsmInfo *TAI); |
| |
| struct SymCmp { |
| // 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 inline bool PartitionByLocal(const MachOSym &Sym) { |
| return (Sym.n_type & (MachOSym::N_EXT | MachOSym::N_PEXT)) == 0; |
| } |
| |
| /// PartitionByDefined - Simple boolean predicate that returns true if Sym is |
| /// defined in this module. |
| |
| static inline bool PartitionByDefined(const MachOSym &Sym) { |
| // FIXME: Do N_ABS or N_INDR count as defined? |
| return (Sym.n_type & MachOSym::N_SECT) == MachOSym::N_SECT; |
| } |
| |
| }; // end struct MachOSym |
| |
| /// 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. |
| std::vector<unsigned char> HeaderData; |
| |
| // Constants for the filetype field |
| // see <mach-o/loader.h> 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 <mach/shared_memory_server.h> |
| 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; |
| } |
| |
| }; // end struct MachOHeader |
| |
| /// 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 <mach-o/vm_prot.h> |
| 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 <mach-o/loader.h> |
| 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 : public BinaryObject { |
| std::string sectname; // name of this section, |
| std::string segname; // segment this section goes in |
| uint64_t addr; // memory address 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; |
| |
| /// RelocBuffer - A buffer to hold the mach-o relocations before we write |
| /// them out at the appropriate location in the file. |
| std::vector<unsigned char> RelocBuffer; |
| |
| // Constants for the section types (low 8 bits of flags field) |
| // see <mach-o/loader.h> |
| 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 <mach-o/loader.h> |
| 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 §) |
| : BinaryObject(), sectname(sect), segname(seg), addr(0), offset(0), |
| align(2), reloff(0), nreloc(0), flags(0), reserved1(0), reserved2(0), |
| reserved3(0) { } |
| |
| }; // end struct MachOSection |
| |
| /// 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 <mach-o/loader.h> |
| 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) {} |
| |
| }; // end struct MachODySymTab |
| |
| } // end namespace llvm |
| |
| #endif |
| |
