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Diffstat (limited to 'lib/CodeGen/MachO.h')
| -rw-r--r-- | lib/CodeGen/MachO.h | 423 |
1 files changed, 423 insertions, 0 deletions
diff --git a/lib/CodeGen/MachO.h b/lib/CodeGen/MachO.h new file mode 100644 index 000000000000..bd9bd61e9ede --- /dev/null +++ b/lib/CodeGen/MachO.h @@ -0,0 +1,423 @@ +//=== 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/Constants.h" +#include "llvm/DerivedTypes.h" +#include "llvm/CodeGen/MachineRelocation.h" +#include "llvm/Target/TargetAsmInfo.h" +#include <string> +#include <vector> + +namespace llvm { + +typedef std::vector<unsigned char> DataBuffer; + +/// 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. + DataBuffer 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 { + 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<MachineRelocation> Relocations; + + // 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 §) + : sectname(sect), segname(seg), addr(0), size(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 namespace llvm + +#endif + |