Initial checkin of the Mach-O emitter. There's plenty of fixmes, but it

does emit linkable .o files in very simple cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29850 91177308-0d34-0410-b5e6-96231b3b80d8

8 files changed, 1118 insertions, 47 deletions

diff --git a/include/llvm/CodeGen/MachOWriter.h b/include/llvm/CodeGen/MachOWriter.h
new file mode 100644
index 0000000..37fa005
--- /dev/null
+++ b/include/llvm/CodeGen/MachOWriter.h
@@ -0,0 +1,600 @@
+//=== MachOWriter.h - Target-independent Mach-O writer support --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the MachOWriter class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_MACHOWRITER_H
+#define LLVM_CODEGEN_MACHOWRITER_H
+
+#include "llvm/CodeGen/MachineRelocation.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include <list>
+
+namespace llvm {
+  class GlobalVariable;
+  class Mangler;
+  class MachineCodeEmitter;
+  class MachOCodeEmitter;
+
+  /// 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:
+    MachineCodeEmitter &getMachineCodeEmitter() const {
+      return *(MachineCodeEmitter*)MCE;
+    }
+
+    ~MachOWriter();
+
+    typedef std::vector<unsigned char> DataBuffer;
+
+  protected:
+    MachOWriter(std::ostream &O, TargetMachine &TM);
+
+    /// Output stream to send the resultant object file to.
+    ///
+    std::ostream &O;
+
+    /// Target machine description.
+    ///
+    TargetMachine &TM;
+
+    /// Mang - The object used to perform name mangling for this module.
+    ///
+    Mangler *Mang;
+
+    /// MCE - The MachineCodeEmitter 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;
+
+    /// 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	cputype;    // cpu specifier
+      uint32_t	cpusubtype; // machine specifier
+      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 cputype field
+      // see <mach/machine.h>
+      enum { CPU_TYPE_I386      = 7,
+             CPU_TYPE_X86_64    = 7 | 0x1000000,
+             CPU_TYPE_ARM       = 12,
+             CPU_TYPE_SPARC     = 14,
+             CPU_TYPE_POWERPC   = 18,
+             CPU_TYPE_POWERPC64 = 18 | 0x1000000
+      };
+      
+      // Constants for the cpusubtype field
+      // see <mach/machine.h>
+      enum { CPU_SUBTYPE_I386_ALL    = 3,
+             CPU_SUBTYPE_X86_64_ALL  = 3,
+             CPU_SUBTYPE_ARM_ALL     = 0,
+             CPU_SUBTYPE_SPARC_ALL   = 0,
+             CPU_SUBTYPE_POWERPC_ALL = 0
+      };
+             
+      // 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), cputype(0), cpusubtype(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;
+    
+  private:
+
+    /// 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
+      
+      // Constants for the vm protection fields
+      // see <mach-o/vm_prot.h>
+      enum { VM_PROT_NONE    = 0x00, 
+             VM_PROT_READ    = 0x01, // read permission
+             VM_PROT_WRITE   = 0x02, // write permission
+             VM_PROT_EXECUTE = 0x04, // execute permission,
+             VM_PROT_ALL     = 0x07
+      };
+      
+      // 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;
+      
+      // 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 &sect)
+        : sectname(sect), segname(seg), addr(0), size(0), offset(0), align(0),
+          reloff(0), nreloc(0), flags(0), reserved1(0), reserved2(0),
+          reserved3(0) { }
+    };
+
+    /// 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::list<MachOSection> SectionList;
+
+    /// SectionLookup - This is a mapping from section name to SectionList entry
+    std::map<std::string, MachOSection*> SectionLookup;
+
+    /// 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 &sect,
+                             unsigned Flags = 0) {
+      MachOSection *&SN = SectionLookup[seg+sect];
+      if (SN) return *SN;
+
+      SectionList.push_back(MachOSection(seg, sect));
+      SN = &SectionList.back();
+      SN->Index = SectionList.size();
+      SN->flags = MachOSection::S_REGULAR | Flags;
+      return *SN;
+    }
+    MachOSection &getTextSection() {
+      return getSection("__TEXT", "__text", 
+                        MachOSection::S_ATTR_PURE_INSTRUCTIONS |
+                        MachOSection::S_ATTR_SOME_INSTRUCTIONS);
+    }
+    
+    /// 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 <mach-o/loader.h>
+      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 <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) { }
+    };
+    
+    /// SymTab - The "stab" style symbol table information
+    MachOSymTab   SymTab;     
+    /// DySymTab - symbol table info for the dynamic link editor
+    MachODySymTab DySymTab;
+
+    /// 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.
+      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
+      };
+      
+      /// entrySize - This routine returns the size of a symbol table entry as
+      /// written to disk.
+      static unsigned entrySize() { return 12; }
+
+      MachOSym(const GlobalValue *gv, uint8_t sect) : GV(gv), n_strx(0), 
+        n_type(N_UNDF), n_sect(sect), n_desc(0), n_value(0) {}
+    };
+
+    /// 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<MachOSym> SymbolTable;
+    
+    /// DynamicSymbolTable - This is just a vector of indices into
+    /// SymbolTable to aid in emitting the DYSYMTAB load command.
+    std::vector<unsigned> DynamicSymbolTable;
+    
+    /// StringTable - The table of strings referenced by SymbolTable entries
+    std::vector<std::string> StringTable;
+
+    // align - Emit padding into the file until the current output position is
+    // aligned to the specified power of two boundary.
+    static void align(DataBuffer &Output, unsigned Boundary) {
+      assert(Boundary && (Boundary & (Boundary-1)) == 0 &&
+             "Must align to 2^k boundary");
+      size_t Size = Output.size();
+      if (Size & (Boundary-1)) {
+        // Add padding to get alignment to the correct place.
+        size_t Pad = Boundary-(Size & (Boundary-1));
+        Output.resize(Size+Pad);
+      }
+    }
+
+    void outbyte(DataBuffer &Output, unsigned char X) {
+      Output.push_back(X);
+    }
+    void outhalf(DataBuffer &Output, unsigned short X) {
+      if (isLittleEndian) {
+        Output.push_back(X&255);
+        Output.push_back(X >> 8);
+      } else {
+        Output.push_back(X >> 8);
+        Output.push_back(X&255);
+      }
+    }
+    void outword(DataBuffer &Output, unsigned X) {
+      if (isLittleEndian) {
+        Output.push_back((X >>  0) & 255);
+        Output.push_back((X >>  8) & 255);
+        Output.push_back((X >> 16) & 255);
+        Output.push_back((X >> 24) & 255);
+      } else {
+        Output.push_back((X >> 24) & 255);
+        Output.push_back((X >> 16) & 255);
+        Output.push_back((X >>  8) & 255);
+        Output.push_back((X >>  0) & 255);
+      }
+    }
+    void outxword(DataBuffer &Output, uint64_t X) {
+      if (isLittleEndian) {
+        Output.push_back(unsigned(X >>  0) & 255);
+        Output.push_back(unsigned(X >>  8) & 255);
+        Output.push_back(unsigned(X >> 16) & 255);
+        Output.push_back(unsigned(X >> 24) & 255);
+        Output.push_back(unsigned(X >> 32) & 255);
+        Output.push_back(unsigned(X >> 40) & 255);
+        Output.push_back(unsigned(X >> 48) & 255);
+        Output.push_back(unsigned(X >> 56) & 255);
+      } else {
+        Output.push_back(unsigned(X >> 56) & 255);
+        Output.push_back(unsigned(X >> 48) & 255);
+        Output.push_back(unsigned(X >> 40) & 255);
+        Output.push_back(unsigned(X >> 32) & 255);
+        Output.push_back(unsigned(X >> 24) & 255);
+        Output.push_back(unsigned(X >> 16) & 255);
+        Output.push_back(unsigned(X >>  8) & 255);
+        Output.push_back(unsigned(X >>  0) & 255);
+      }
+    }
+    void outaddr32(DataBuffer &Output, unsigned X) {
+      outword(Output, X);
+    }
+    void outaddr64(DataBuffer &Output, uint64_t X) {
+      outxword(Output, X);
+    }
+    void outaddr(DataBuffer &Output, uint64_t X) {
+      if (!is64Bit)
+        outword(Output, (unsigned)X);
+      else
+        outxword(Output, X);
+    }
+    void outstring(DataBuffer &Output, std::string &S, unsigned Length) {
+      char *buffer = (char *)calloc(1, Length);
+      unsigned i;
+      // FIXME: it is unclear if mach-o requires null terminated strings, or
+      //        if a string of 16 bytes with no null terminator is ok.  If so,
+      //        we should switch to strncpy.
+      strlcpy(buffer, S.c_str(), Length);
+      
+      for (i = 0; i < Length; ++i)
+        outbyte(Output, buffer[i]);
+      
+      free(buffer);
+    }
+  private:
+    void EmitGlobal(GlobalVariable *GV);
+    void EmitHeaderAndLoadCommands();
+    void EmitSections();
+    void EmitRelocations();
+    void EmitSymbolTable();
+    void EmitStringTable();
+  };
+}
+
+#endif
diff --git a/lib/CodeGen/MachOWriter.cpp b/lib/CodeGen/MachOWriter.cpp
new file mode 100644
index 0000000..e3228cb
--- /dev/null
+++ b/lib/CodeGen/MachOWriter.cpp
@@ -0,0 +1,428 @@
+//===-- MachOWriter.cpp - Target-independent Mach-O Writer code -----------===//
+//
+//                     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 implements the target-independent Mach-O writer.  This file writes
+// out the Mach-O file in the following order:
+//
+//  #1 FatHeader (universal-only)
+//  #2 FatArch (universal-only, 1 per universal arch)
+//  Per arch:
+//    #3 Header
+//    #4 Load Commands
+//    #5 Sections
+//    #6 Relocations
+//    #7 Symbols
+//    #8 Strings
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Module.h"
+#include "llvm/CodeGen/MachineCodeEmitter.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineRelocation.h"
+#include "llvm/CodeGen/MachOWriter.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetJITInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Support/Mangler.h"
+#include <iostream>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+//                       MachOCodeEmitter Implementation
+//===----------------------------------------------------------------------===//
+
+namespace llvm {
+  /// MachOCodeEmitter - This class is used by the MachOWriter to emit the code 
+  /// for functions to the Mach-O file.
+  class MachOCodeEmitter : public MachineCodeEmitter {
+    MachOWriter &MOW;
+    
+    /// MOS - The current section we're writing to
+    MachOWriter::MachOSection *MOS;
+
+    /// Relocations - These are the relocations that the function needs, as
+    /// emitted.
+    std::vector<MachineRelocation> Relocations;
+
+    /// MBBLocations - This vector is a mapping from MBB ID's to their address.
+    /// It is filled in by the StartMachineBasicBlock callback and queried by
+    /// the getMachineBasicBlockAddress callback.
+    std::vector<intptr_t> MBBLocations;
+    
+  public:
+    MachOCodeEmitter(MachOWriter &mow) : MOW(mow) {}
+
+    void startFunction(MachineFunction &F);
+    bool finishFunction(MachineFunction &F);
+
+    void addRelocation(const MachineRelocation &MR) {
+      Relocations.push_back(MR);
+    }
+    
+    virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
+      if (MBBLocations.size() <= (unsigned)MBB->getNumber())
+        MBBLocations.resize((MBB->getNumber()+1)*2);
+      MBBLocations[MBB->getNumber()] = getCurrentPCValue();
+    }
+
+    virtual intptr_t getConstantPoolEntryAddress(unsigned Index) const {
+      assert(0 && "CP not implementated yet!");
+      return 0;
+    }
+    virtual intptr_t getJumpTableEntryAddress(unsigned Index) const {
+      assert(0 && "JT not implementated yet!");
+      return 0;
+    }
+
+    virtual intptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
+      assert(MBBLocations.size() > (unsigned)MBB->getNumber() && 
+             MBBLocations[MBB->getNumber()] && "MBB not emitted!");
+      return MBBLocations[MBB->getNumber()];
+    }
+
+    /// JIT SPECIFIC FUNCTIONS - DO NOT IMPLEMENT THESE HERE!
+    void startFunctionStub(unsigned StubSize) {
+      assert(0 && "JIT specific function called!");
+      abort();
+    }
+    void *finishFunctionStub(const Function *F) {
+      assert(0 && "JIT specific function called!");
+      abort();
+      return 0;
+    }
+  };
+}
+
+/// startFunction - This callback is invoked when a new machine function is
+/// about to be emitted.
+void MachOCodeEmitter::startFunction(MachineFunction &F) {
+  // Align the output buffer to the appropriate alignment, power of 2.
+  // FIXME: GENERICIZE!!
+  unsigned Align = 4;
+
+  // Get the Mach-O Section that this function belongs in.
+  MOS = &MOW.getTextSection();
+  
+   // FIXME: better memory management
+  MOS->SectionData.reserve(4096);
+  BufferBegin = &(MOS->SectionData[0]);
+  BufferEnd = BufferBegin + MOS->SectionData.capacity();
+  CurBufferPtr = BufferBegin + MOS->size;
+
+  // Upgrade the section alignment if required.
+  if (MOS->align < Align) MOS->align = Align;
+
+  // Make sure we only relocate to this function's MBBs.
+  MBBLocations.clear();
+}
+
+/// finishFunction - This callback is invoked after the function is completely
+/// finished.
+bool MachOCodeEmitter::finishFunction(MachineFunction &F) {
+  MOS->size += CurBufferPtr - BufferBegin;
+  
+  // Get a symbol for the function to add to the symbol table
+  MachOWriter::MachOSym FnSym(F.getFunction(), MOS->Index);
+  
+  // Figure out the binding (linkage) of the symbol.
+  switch (F.getFunction()->getLinkage()) {
+  default:
+    // appending linkage is illegal for functions.
+    assert(0 && "Unknown linkage type!");
+  case GlobalValue::ExternalLinkage:
+    FnSym.n_type = MachOWriter::MachOSym::N_SECT | MachOWriter::MachOSym::N_EXT;
+    break;
+  case GlobalValue::InternalLinkage:
+    FnSym.n_type = MachOWriter::MachOSym::N_SECT;
+    break;
+  }
+  
+  // Resolve the function's relocations either to concrete pointers in the case
+  // of branches from one block to another, or to target relocation entries.
+  for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
+    MachineRelocation &MR = Relocations[i];
+    if (MR.isBasicBlock()) {
+      void *MBBAddr = (void *)getMachineBasicBlockAddress(MR.getBasicBlock());
+      MR.setResultPointer(MBBAddr);
+      MOW.TM.getJITInfo()->relocate(BufferBegin, &MR, 1, 0);
+      // FIXME: we basically want the JITInfo relocate() function to rewrite
+      //        this guy right now, so we just write the correct displacement
+      //        to the file.
+    } else {
+      // isString | isGV | isCPI | isJTI
+      // FIXME: do something smart here.  We won't be able to relocate these
+      //        until the sections are all layed out, but we still need to
+      //        record them.  Maybe emit TargetRelocations and then resolve
+      //        those at file writing time?
+      std::cerr << "whee!\n";
+    }
+  }
+  Relocations.clear();
+  
+  // Finally, add it to the symtab.
+  MOW.SymbolTable.push_back(FnSym);
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+//                          MachOWriter Implementation
+//===----------------------------------------------------------------------===//
+
+MachOWriter::MachOWriter(std::ostream &o, TargetMachine &tm) : O(o), TM(tm) {
+  // FIXME: set cpu type and cpu subtype somehow from TM
+  is64Bit = TM.getTargetData()->getPointerSizeInBits() == 64;
+  isLittleEndian = TM.getTargetData()->isLittleEndian();
+
+  // Create the machine code emitter object for this target.
+  MCE = new MachOCodeEmitter(*this);
+}
+
+MachOWriter::~MachOWriter() {
+  delete MCE;
+}
+
+void MachOWriter::EmitGlobal(GlobalVariable *GV) {
+  // FIXME: do something smart here.
+}
+
+
+bool MachOWriter::runOnMachineFunction(MachineFunction &MF) {
+  // Nothing to do here, this is all done through the MCE object.
+  return false;
+}
+
+bool MachOWriter::doInitialization(Module &M) {
+  // Set the magic value, now that we know the pointer size and endianness
+  Header.setMagic(isLittleEndian, is64Bit);
+
+  // Set the file type
+  // FIXME: this only works for object files, we do not support the creation
+  //        of dynamic libraries or executables at this time.
+  Header.filetype = MachOHeader::MH_OBJECT;
+
+  Mang = new Mangler(M);
+  return false;
+}
+
+/// doFinalization - Now that the module has been completely processed, emit
+/// the Mach-O file to 'O'.
+bool MachOWriter::doFinalization(Module &M) {
+  // Okay, the.text section has been completed, build the .data, .bss, and 
+  // "common" sections next.
+  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
+       I != E; ++I)
+    EmitGlobal(I);
+  
+  // Emit the header and load commands.
+  EmitHeaderAndLoadCommands();
+
+  // Emit the text and data sections.
+  EmitSections();
+
+  // Emit the relocation entry data for each section.
+  // FIXME: presumably this should be a virtual method, since different targets
+  //        have different relocation types.
+  EmitRelocations();
+
+  // Emit the symbol table.
+  // FIXME: we don't handle debug info yet, we should probably do that.
+  EmitSymbolTable();
+
+  // Emit the string table for the sections we have.
+  EmitStringTable();
+
+  // We are done with the abstract symbols.
+  SectionList.clear();
+  SymbolTable.clear();
+  DynamicSymbolTable.clear();
+
+  // Release the name mangler object.
+  delete Mang; Mang = 0;
+  return false;
+}
+
+void MachOWriter::EmitHeaderAndLoadCommands() {
+  // Step #0: Fill in the segment load command size, since we need it to figure
+  //          out the rest of the header fields
+  MachOSegment SEG("", is64Bit);
+  SEG.nsects  = SectionList.size();
+  SEG.cmdsize = SEG.cmdSize(is64Bit) + 
+                SEG.nsects * SectionList.begin()->cmdSize(is64Bit);
+  
+  // Step #1: calculate the number of load commands.  We always have at least
+  //          one, for the LC_SEGMENT load command, plus two for the normal
+  //          and dynamic symbol tables, if there are any symbols.
+  Header.ncmds = SymbolTable.empty() ? 1 : 3;
+  
+  // Step #2: calculate the size of the load commands
+  Header.sizeofcmds = SEG.cmdsize;
+  if (!SymbolTable.empty())
+    Header.sizeofcmds += SymTab.cmdsize + DySymTab.cmdsize;
+    
+  // Step #3: write the header to the file
+  // Local alias to shortenify coming code.
+  DataBuffer &FH = Header.HeaderData;
+  outword(FH, Header.magic);
+  outword(FH, Header.cputype);
+  outword(FH, Header.cpusubtype);
+  outword(FH, Header.filetype);
+  outword(FH, Header.ncmds);
+  outword(FH, Header.sizeofcmds);
+  outword(FH, Header.flags);
+  if (is64Bit)
+    outword(FH, Header.reserved);
+  
+  // Step #4: Finish filling in the segment load command and write it out
+  for (std::list<MachOSection>::iterator I = SectionList.begin(),
+         E = SectionList.end(); I != E; ++I)
+    SEG.filesize += I->size;
+  SEG.vmsize = SEG.filesize;
+  SEG.fileoff = Header.cmdSize(is64Bit) + Header.sizeofcmds;
+  
+  outword(FH, SEG.cmd);
+  outword(FH, SEG.cmdsize);
+  outstring(FH, SEG.segname, 16);
+  outaddr(FH, SEG.vmaddr);
+  outaddr(FH, SEG.vmsize);
+  outaddr(FH, SEG.fileoff);
+  outaddr(FH, SEG.filesize);
+  outword(FH, SEG.maxprot);
+  outword(FH, SEG.initprot);
+  outword(FH, SEG.nsects);
+  outword(FH, SEG.flags);
+  
+  // Step #5: Write out the section commands for each section
+  for (std::list<MachOSection>::iterator I = SectionList.begin(),
+         E = SectionList.end(); I != E; ++I) {
+    I->offset = SEG.fileoff;  // FIXME: separate offset
+    outstring(FH, I->sectname, 16);
+    outstring(FH, I->segname, 16);
+    outaddr(FH, I->addr);
+    outaddr(FH, I->size);
+    outword(FH, I->offset);
+    outword(FH, I->align);
+    outword(FH, I->reloff);
+    outword(FH, I->nreloc);
+    outword(FH, I->flags);
+    outword(FH, I->reserved1);
+    outword(FH, I->reserved2);
+    if (is64Bit)
+      outword(FH, I->reserved3);
+  }
+  
+  // Step #6: Emit LC_SYMTAB/LC_DYSYMTAB load commands
+  // FIXME: We'll need to scan over the symbol table and possibly do the sort
+  // here so that we can set the proper indices in the dysymtab load command for
+  // the index and number of external symbols defined in this module.
+  // FIXME: We'll also need to scan over all the symbols so that we can 
+  // calculate the size of the string table.
+  // FIXME: add size of relocs
+  SymTab.symoff  = SEG.fileoff + SEG.filesize;
+  SymTab.nsyms   = SymbolTable.size();
+  SymTab.stroff  = SymTab.symoff + SymTab.nsyms * MachOSym::entrySize();
+  SymTab.strsize = 10;
+  outword(FH, SymTab.cmd);
+  outword(FH, SymTab.cmdsize);
+  outword(FH, SymTab.symoff);
+  outword(FH, SymTab.nsyms);
+  outword(FH, SymTab.stroff);
+  outword(FH, SymTab.strsize);
+
+  // FIXME: set DySymTab fields appropriately
+  outword(FH, DySymTab.cmd);
+  outword(FH, DySymTab.cmdsize);
+  outword(FH, DySymTab.ilocalsym);
+  outword(FH, DySymTab.nlocalsym);
+  outword(FH, DySymTab.iextdefsym);
+  outword(FH, DySymTab.nextdefsym);
+  outword(FH, DySymTab.iundefsym);
+  outword(FH, DySymTab.nundefsym);
+  outword(FH, DySymTab.tocoff);
+  outword(FH, DySymTab.ntoc);
+  outword(FH, DySymTab.modtaboff);
+  outword(FH, DySymTab.nmodtab);
+  outword(FH, DySymTab.extrefsymoff);
+  outword(FH, DySymTab.nextrefsyms);
+  outword(FH, DySymTab.indirectsymoff);
+  outword(FH, DySymTab.nindirectsyms);
+  outword(FH, DySymTab.extreloff);
+  outword(FH, DySymTab.nextrel);
+  outword(FH, DySymTab.locreloff);
+  outword(FH, DySymTab.nlocrel);
+  
+  O.write((char*)&FH[0], FH.size());
+}
+
+/// EmitSections - Now that we have constructed the file header and load
+/// commands, emit the data for each section to the file.
+void MachOWriter::EmitSections() {
+  for (std::list<MachOSection>::iterator I = SectionList.begin(),
+         E = SectionList.end(); I != E; ++I) {
+    O.write((char*)&I->SectionData[0], I->size);
+  }
+}
+
+void MachOWriter::EmitRelocations() {
+  // FIXME: this should probably be a pure virtual function, since the
+  // relocation types and layout of the relocations themselves are target
+  // specific.
+}
+
+/// EmitSymbolTable - Sort the symbols we encountered and assign them each a 
+/// string table index so that they appear in the correct order in the output 
+/// file.
+void MachOWriter::EmitSymbolTable() {
+  // The order of the symbol table is:
+  // local symbols
+  // defined external symbols (sorted by name)
+  // undefined external symbols (sorted by name)
+  DataBuffer ST;
+  
+  // FIXME: enforce the above ordering, presumably by sorting by name, 
+  // then partitioning twice.
+  unsigned stringIndex;
+  for (std::vector<MachOSym>::iterator I = SymbolTable.begin(),
+         E = SymbolTable.end(); I != E; ++I) {
+    // FIXME: remove when we actually calculate these correctly
+    I->n_strx = 1;
+    StringTable.push_back(Mang->getValueName(I->GV));
+    // Emit nlist to buffer
+    outword(ST, I->n_strx);
+    outbyte(ST, I->n_type);
+    outbyte(ST, I->n_sect);
+    outhalf(ST, I->n_desc);
+    outaddr(ST, I->n_value);
+  }
+  
+  O.write((char*)&ST[0], ST.size());
+}
+
+/// EmitStringTable - This method adds and emits a section for the Mach-O 
+/// string table.
+void MachOWriter::EmitStringTable() {
+  // The order of the string table is:
+  // strings for external symbols
+  // strings for local symbols
+  // This is the symbol table, but backwards.  This allows us to avoid a sorting
+  // the symbol table again; all we have to do is use a reverse iterator.
+  DataBuffer ST;
+
+  // Write out a leading zero byte when emitting string table, for n_strx == 0
+  // which means an empty string.
+  outbyte(ST, 0);
+
+  for (std::vector<std::string>::iterator I = StringTable.begin(),
+         E = StringTable.end(); I != E; ++I) {
+    // FIXME: do not arbitrarily cap symbols to 16 characters
+    // FIXME: do something more efficient than outstring
+    outstring(ST, *I, 16);
+  }
+  O.write((char*)&ST[0], ST.size());
+}
diff --git a/lib/Target/PowerPC/PPC.h b/lib/Target/PowerPC/PPC.h
index 5e8e15c..f34b9b0 100644
--- a/lib/Target/PowerPC/PPC.h
+++ b/lib/Target/PowerPC/PPC.h
@@ -19,11 +19,18 @@
 
 namespace llvm {
 
-class FunctionPass;
 class PPCTargetMachine;
+class PassManager;
+class FunctionPass;
+class MachineCodeEmitter;
+
 FunctionPass *createPPCBranchSelectionPass();
 FunctionPass *createPPCISelDag(PPCTargetMachine &TM);
 FunctionPass *createDarwinAsmPrinter(std::ostream &OS, PPCTargetMachine &TM);
+FunctionPass *createPPCCodeEmitterPass(PPCTargetMachine &TM,
+                                       MachineCodeEmitter &MCE);
+void addPPCMachOObjectWriterPass(PassManager &FPM, std::ostream &o, 
+                                 PPCTargetMachine &tm);
 } // end namespace llvm;
 
 // GCC #defines PPC on Linux but we use it as our namespace name
diff --git a/lib/Target/PowerPC/PPCCodeEmitter.cpp b/lib/Target/PowerPC/PPCCodeEmitter.cpp
index 49d3f25..85697f9 100644
--- a/lib/Target/PowerPC/PPCCodeEmitter.cpp
+++ b/lib/Target/PowerPC/PPCCodeEmitter.cpp
@@ -21,7 +21,7 @@
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/Passes.h"
-#include "llvm/Support/Debug.h"
+#include "llvm/Support/Debug.h"                   
 #include "llvm/Support/Visibility.h"
 #include "llvm/Target/TargetOptions.h"
 #include <iostream>
@@ -62,19 +62,11 @@ namespace {
   };
 }
 
-/// addPassesToEmitMachineCode - Add passes to the specified pass manager to get
-/// machine code emitted.  This uses a MachineCodeEmitter object to handle
-/// actually outputting the machine code and resolving things like the address
-/// of functions.  This method should returns true if machine code emission is
-/// not supported.
-///
-bool PPCTargetMachine::addPassesToEmitMachineCode(FunctionPassManager &PM,
-                                                  MachineCodeEmitter &MCE) {
-  // Machine code emitter pass for PowerPC
-  PM.add(new PPCCodeEmitter(*this, MCE));
-  // Delete machine code for this function after emitting it
-  PM.add(createMachineCodeDeleter());
-  return false;
+/// createPPCCodeEmitterPass - Return a pass that emits the collected PPC code
+/// to the specified MCE object.
+FunctionPass *llvm::createPPCCodeEmitterPass(PPCTargetMachine &TM,
+                                             MachineCodeEmitter &MCE) {
+  return new PPCCodeEmitter(TM, MCE);
 }
 
 #ifdef __APPLE__ 
@@ -132,7 +124,8 @@ int PPCCodeEmitter::getMachineOpValue(MachineInstr &MI, MachineOperand &MO) {
     }
   } else if (MO.isImmediate()) {
     rv = MO.getImmedValue();
-  } else if (MO.isGlobalAddress() || MO.isExternalSymbol()) {
+  } else if (MO.isGlobalAddress() || MO.isExternalSymbol() ||
+             MO.isConstantPoolIndex() || MO.isJumpTableIndex()) {
     unsigned Reloc = 0;
     if (MI.getOpcode() == PPC::BL)
       Reloc = PPC::reloc_pcrel_bx;
@@ -141,6 +134,7 @@ int PPCCodeEmitter::getMachineOpValue(MachineInstr &MI, MachineOperand &MO) {
       default: DEBUG(MI.dump()); assert(0 && "Unknown instruction for relocation!");
       case PPC::LIS:
       case PPC::LIS8:
+      case PPC::ADDIS:
       case PPC::ADDIS8:
         Reloc = PPC::reloc_absolute_high;       // Pointer to symbol
         break;
@@ -176,9 +170,17 @@ int PPCCodeEmitter::getMachineOpValue(MachineInstr &MI, MachineOperand &MO) {
     if (MO.isGlobalAddress())
       MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(),
                                           Reloc, MO.getGlobal(), 0));
-    else
+    else if (MO.isExternalSymbol())
       MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
                                           Reloc, MO.getSymbolName(), 0));
+    else if (MO.isConstantPoolIndex())
+      MCE.addRelocation(MachineRelocation::getConstPool(
+                                          MCE.getCurrentPCOffset(),
+                                          Reloc, MO.getConstantPoolIndex(), 0));
+    else // isJumpTableIndex
+      MCE.addRelocation(MachineRelocation::getJumpTable(
+                                          MCE.getCurrentPCOffset(),
+                                          Reloc, MO.getJumpTableIndex(), 0));
   } else if (MO.isMachineBasicBlock()) {
     unsigned Reloc = 0;
     unsigned Opcode = MI.getOpcode();
@@ -190,28 +192,6 @@ int PPCCodeEmitter::getMachineOpValue(MachineInstr &MI, MachineOperand &MO) {
     MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
                                                Reloc,
                                                MO.getMachineBasicBlock()));
-  } else if (MO.isConstantPoolIndex() || MO.isJumpTableIndex()) {
-    if (MO.isConstantPoolIndex())
-      rv = MCE.getConstantPoolEntryAddress(MO.getConstantPoolIndex());
-    else
-      rv = MCE.getJumpTableEntryAddress(MO.getJumpTableIndex());
-
-    unsigned Opcode = MI.getOpcode();
-    if (Opcode == PPC::LIS || Opcode == PPC::LIS8 ||
-        Opcode == PPC::ADDIS || Opcode == PPC::ADDIS8) {
-      // lis wants hi16(addr)
-      if ((short)rv < 0) rv += 1 << 16;
-      rv >>= 16;
-    } else if (Opcode == PPC::LWZ || Opcode == PPC::LWZ8 ||
-               Opcode == PPC::LA ||
-               Opcode == PPC::LI  || Opcode == PPC::LI8 ||
-               Opcode == PPC::LFS || Opcode == PPC::LFD) {
-      // These load opcodes want lo16(addr)
-      rv &= 0xffff;
-    } else {
-      MI.dump();
-      assert(0 && "Unknown constant pool or jump table using instruction!");
-    }
   } else {
     std::cerr << "ERROR: Unknown type of MachineOperand: " << MO << "\n";
     abort();
diff --git a/lib/Target/PowerPC/PPCMachOWriter.cpp b/lib/Target/PowerPC/PPCMachOWriter.cpp
new file mode 100644
index 0000000..29f8238
--- /dev/null
+++ b/lib/Target/PowerPC/PPCMachOWriter.cpp
@@ -0,0 +1,41 @@
+//===-- PPCMachOWriter.cpp - Emit a Mach-O file for the PowerPC backend ---===//
+//
+//                     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 implements a Mach-O writer for the PowerPC backend.  The public
+// interface to this file is the createPPCMachOObjectWriterPass function.
+//
+//===----------------------------------------------------------------------===//
+
+#include "PPCTargetMachine.h"
+#include "llvm/PassManager.h"
+#include "llvm/CodeGen/MachOWriter.h"
+#include "llvm/Support/Visibility.h"
+using namespace llvm;
+
+namespace {
+  class VISIBILITY_HIDDEN PPCMachOWriter : public MachOWriter {
+  public:
+    PPCMachOWriter(std::ostream &O, PPCTargetMachine &TM) : MachOWriter(O, TM) {
+      // FIMXE: choose ppc64 when appropriate
+      Header.cputype = MachOHeader::CPU_TYPE_POWERPC;
+      Header.cpusubtype = MachOHeader::CPU_SUBTYPE_POWERPC_ALL;
+    }
+
+  };
+}
+
+/// addPPCMachOObjectWriterPass - Returns a pass that outputs the generated code
+/// as a Mach-O object file.
+///
+void llvm::addPPCMachOObjectWriterPass(PassManager &FPM,
+                                       std::ostream &O, PPCTargetMachine &TM) {
+  PPCMachOWriter *EW = new PPCMachOWriter(O, TM);
+  FPM.add(EW);
+  FPM.add(createPPCCodeEmitterPass(TM, EW->getMachineCodeEmitter()));
+}
diff --git a/lib/Target/PowerPC/PPCTargetMachine.cpp b/lib/Target/PowerPC/PPCTargetMachine.cpp
index deb479a..e360f37 100644
--- a/lib/Target/PowerPC/PPCTargetMachine.cpp
+++ b/lib/Target/PowerPC/PPCTargetMachine.cpp
@@ -109,11 +109,11 @@ PPC64TargetMachine::PPC64TargetMachine(const Module &M, const std::string &FS)
 /// addPassesToEmitFile - Add passes to the specified pass manager to implement
 /// a static compiler for this target.
 ///
-bool PPCTargetMachine::addPassesToEmitFile(PassManager &PM,
-                                           std::ostream &Out,
+bool PPCTargetMachine::addPassesToEmitFile(PassManager &PM, std::ostream &Out,
                                            CodeGenFileType FileType,
                                            bool Fast) {
-  if (FileType != TargetMachine::AssemblyFile) return true;
+  if (FileType != TargetMachine::AssemblyFile &&
+      FileType != TargetMachine::ObjectFile) return true;
   
   // Run loop strength reduction before anything else.
   if (!Fast) PM.add(createLoopStrengthReducePass(&TLInfo));
@@ -146,7 +146,11 @@ bool PPCTargetMachine::addPassesToEmitFile(PassManager &PM,
   // Must run branch selection immediately preceding the asm printer
   PM.add(createPPCBranchSelectionPass());
 
-  PM.add(createDarwinAsmPrinter(Out, *this));
+  if (FileType == TargetMachine::AssemblyFile)
+    PM.add(createDarwinAsmPrinter(Out, *this));
+  else
+    // FIXME: support PPC ELF files at some point
+    addPPCMachOObjectWriterPass(PM, Out, *this);
 
   PM.add(createMachineCodeDeleter());
   return false;
@@ -184,3 +188,17 @@ void PPCJITInfo::addPassesToJITCompile(FunctionPassManager &PM) {
     PM.add(createMachineFunctionPrinterPass(&std::cerr));
 }
 
+/// addPassesToEmitMachineCode - Add passes to the specified pass manager to get
+/// machine code emitted.  This uses a MachineCodeEmitter object to handle
+/// actually outputting the machine code and resolving things like the address
+/// of functions.  This method should returns true if machine code emission is
+/// not supported.
+///
+bool PPCTargetMachine::addPassesToEmitMachineCode(FunctionPassManager &PM,
+                                                  MachineCodeEmitter &MCE) {
+  // Machine code emitter pass for PowerPC
+  PM.add(createPPCCodeEmitterPass(*this, MCE));
+  // Delete machine code for this function after emitting it
+  PM.add(createMachineCodeDeleter());
+  return false;
+}
diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp
index 90175ac..9616dc1 100644
--- a/lib/Target/X86/X86TargetMachine.cpp
+++ b/lib/Target/X86/X86TargetMachine.cpp
@@ -136,7 +136,7 @@ bool X86TargetMachine::addPassesToEmitFile(PassManager &PM, std::ostream &Out,
     case TargetMachine::ObjectFile:
       // FIXME: We only support emission of ELF files for now, this should check
       // the target triple and decide on the format to write (e.g. COFF on
-      // win32).
+      // win32 or Mach-O on darwin).
       addX86ELFObjectWriterPass(PM, Out, *this);
       break;
     }
diff --git a/tools/llc/llc.cpp b/tools/llc/llc.cpp
index 93391e9..3ec213b 100644
--- a/tools/llc/llc.cpp
+++ b/tools/llc/llc.cpp
@@ -219,9 +219,6 @@ int main(int argc, char **argv) {
       }
     }
 
-    if (FileType != TargetMachine::AssemblyFile)
-      std::cerr << "WARNING: only -filetype=asm is currently supported.\n";
-    
     // Ask the target to add backend passes as necessary.
     if (Target.addPassesToEmitFile(Passes, *Out, FileType, Fast)) {
       std::cerr << argv[0] << ": target '" << Target.getName()