1 //=== MachOWriter.h - Target-independent Mach-O writer support --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Nate Begeman and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the MachOWriter class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CODEGEN_MACHOWRITER_H
15 #define LLVM_CODEGEN_MACHOWRITER_H
17 #include "llvm/DerivedTypes.h"
18 #include "llvm/CodeGen/MachineFunctionPass.h"
19 #include "llvm/CodeGen/MachineRelocation.h"
20 #include "llvm/Target/TargetData.h"
21 #include "llvm/Target/TargetMachine.h"
26 class MachineCodeEmitter;
27 class MachOCodeEmitter;
30 /// MachOSym - This struct contains information about each symbol that is
31 /// added to logical symbol table for the module. This is eventually
32 /// turned into a real symbol table in the file.
34 const GlobalValue *GV; // The global value this corresponds to.
35 std::string GVName; // The mangled name of the global value.
36 uint32_t n_strx; // index into the string table
37 uint8_t n_type; // type flag
38 uint8_t n_sect; // section number or NO_SECT
39 int16_t n_desc; // see <mach-o/stab.h>
40 uint64_t n_value; // value for this symbol (or stab offset)
42 // Constants for the n_sect field
43 // see <mach-o/nlist.h>
44 enum { NO_SECT = 0 }; // symbol is not in any section
46 // Constants for the n_type field
47 // see <mach-o/nlist.h>
48 enum { N_UNDF = 0x0, // undefined, n_sect == NO_SECT
49 N_ABS = 0x2, // absolute, n_sect == NO_SECT
50 N_SECT = 0xe, // defined in section number n_sect
51 N_PBUD = 0xc, // prebound undefined (defined in a dylib)
52 N_INDR = 0xa // indirect
54 // The following bits are OR'd into the types above. For example, a type
55 // of 0x0f would be an external N_SECT symbol (0x0e | 0x01).
56 enum { N_EXT = 0x01, // external symbol bit
57 N_PEXT = 0x10 // private external symbol bit
60 // Constants for the n_desc field
61 // see <mach-o/loader.h>
62 enum { REFERENCE_FLAG_UNDEFINED_NON_LAZY = 0,
63 REFERENCE_FLAG_UNDEFINED_LAZY = 1,
64 REFERENCE_FLAG_DEFINED = 2,
65 REFERENCE_FLAG_PRIVATE_DEFINED = 3,
66 REFERENCE_FLAG_PRIVATE_UNDEFINED_NON_LAZY = 4,
67 REFERENCE_FLAG_PRIVATE_UNDEFINED_LAZY = 5
69 enum { N_NO_DEAD_STRIP = 0x0020, // symbol is not to be dead stripped
70 N_WEAK_REF = 0x0040, // symbol is weak referenced
71 N_WEAK_DEF = 0x0080 // coalesced symbol is a weak definition
74 MachOSym(const GlobalValue *gv, std::string name, uint8_t sect,
78 /// MachOWriter - This class implements the common target-independent code for
79 /// writing Mach-O files. Targets should derive a class from this to
80 /// parameterize the output format.
82 class MachOWriter : public MachineFunctionPass {
83 friend class MachOCodeEmitter;
85 MachineCodeEmitter &getMachineCodeEmitter() const {
86 return *(MachineCodeEmitter*)MCE;
91 typedef std::vector<unsigned char> DataBuffer;
94 MachOWriter(std::ostream &O, TargetMachine &TM);
96 /// Output stream to send the resultant object file to.
100 /// Target machine description.
104 /// Target object writer info.
106 const TargetObjInfo *TOI;
108 /// Mang - The object used to perform name mangling for this module.
112 /// MCE - The MachineCodeEmitter object that we are exposing to emit machine
113 /// code for functions to the .o file.
114 MachOCodeEmitter *MCE;
116 /// is64Bit/isLittleEndian - This information is inferred from the target
117 /// machine directly, indicating what header values and flags to set.
118 bool is64Bit, isLittleEndian;
120 /// doInitialization - Emit the file header and all of the global variables
121 /// for the module to the Mach-O file.
122 bool doInitialization(Module &M);
124 bool runOnMachineFunction(MachineFunction &MF);
126 /// doFinalization - Now that the module has been completely processed, emit
127 /// the Mach-O file to 'O'.
128 bool doFinalization(Module &M);
130 /// MachOHeader - This struct contains the header information about a
131 /// specific architecture type/subtype pair that is emitted to the file.
133 uint32_t magic; // mach magic number identifier
134 uint32_t cputype; // cpu specifier
135 uint32_t cpusubtype; // machine specifier
136 uint32_t filetype; // type of file
137 uint32_t ncmds; // number of load commands
138 uint32_t sizeofcmds; // the size of all the load commands
139 uint32_t flags; // flags
140 uint32_t reserved; // 64-bit only
142 /// HeaderData - The actual data for the header which we are building
143 /// up for emission to the file.
144 DataBuffer HeaderData;
146 // The various CPU_TYPE_* constants are already defined by at least one
147 // system header file and create compilation errors if not respected.
148 #if !defined(CPU_TYPE_I386)
149 #define CPU_TYPE_I386 7
151 #if !defined(CPU_TYPE_X86_64)
152 #define CPU_TYPE_X86_64 (CPU_TYPE_I386 | 0x1000000)
154 #if !defined(CPU_TYPE_ARM)
155 #define CPU_TYPE_ARM 12
157 #if !defined(CPU_TYPE_SPARC)
158 #define CPU_TYPE_SPARC 14
160 #if !defined(CPU_TYPE_POWERPC)
161 #define CPU_TYPE_POWERPC 18
163 #if !defined(CPU_TYPE_POWERPC64)
164 #define CPU_TYPE_POWERPC64 (CPU_TYPE_POWERPC | 0x1000000)
167 // Constants for the cputype field
168 // see <mach/machine.h>
169 enum { HDR_CPU_TYPE_I386 = CPU_TYPE_I386,
170 HDR_CPU_TYPE_X86_64 = CPU_TYPE_X86_64,
171 HDR_CPU_TYPE_ARM = CPU_TYPE_ARM,
172 HDR_CPU_TYPE_SPARC = CPU_TYPE_SPARC,
173 HDR_CPU_TYPE_POWERPC = CPU_TYPE_POWERPC,
174 HDR_CPU_TYPE_POWERPC64 = CPU_TYPE_POWERPC64
177 #if !defined(CPU_SUBTYPE_I386_ALL)
178 #define CPU_SUBTYPE_I386_ALL 3
180 #if !defined(CPU_SUBTYPE_X86_64_ALL)
181 #define CPU_SUBTYPE_X86_64_ALL 3
183 #if !defined(CPU_SUBTYPE_ARM_ALL)
184 #define CPU_SUBTYPE_ARM_ALL 0
186 #if !defined(CPU_SUBTYPE_SPARC_ALL)
187 #define CPU_SUBTYPE_SPARC_ALL 0
189 #if !defined(CPU_SUBTYPE_POWERPC_ALL)
190 #define CPU_SUBTYPE_POWERPC_ALL 0
193 // Constants for the cpusubtype field
194 // see <mach/machine.h>
195 enum { HDR_CPU_SUBTYPE_I386_ALL = CPU_SUBTYPE_I386_ALL,
196 HDR_CPU_SUBTYPE_X86_64_ALL = CPU_SUBTYPE_X86_64_ALL,
197 HDR_CPU_SUBTYPE_ARM_ALL = CPU_SUBTYPE_ARM_ALL,
198 HDR_CPU_SUBTYPE_SPARC_ALL = CPU_SUBTYPE_SPARC_ALL,
199 HDR_CPU_SUBTYPE_POWERPC_ALL = CPU_SUBTYPE_POWERPC_ALL
202 // Constants for the filetype field
203 // see <mach-o/loader.h> for additional info on the various types
204 enum { MH_OBJECT = 1, // relocatable object file
205 MH_EXECUTE = 2, // demand paged executable file
206 MH_FVMLIB = 3, // fixed VM shared library file
207 MH_CORE = 4, // core file
208 MH_PRELOAD = 5, // preloaded executable file
209 MH_DYLIB = 6, // dynamically bound shared library
210 MH_DYLINKER = 7, // dynamic link editor
211 MH_BUNDLE = 8, // dynamically bound bundle file
212 MH_DYLIB_STUB = 9, // shared library stub for static linking only
213 MH_DSYM = 10 // companion file wiht only debug sections
216 // Constants for the flags field
217 enum { MH_NOUNDEFS = 1 << 0,
218 // the object file has no undefined references
219 MH_INCRLINK = 1 << 1,
220 // the object file is the output of an incremental link against
221 // a base file and cannot be link edited again
222 MH_DYLDLINK = 1 << 2,
223 // the object file is input for the dynamic linker and cannot be
224 // statically link edited again.
225 MH_BINDATLOAD = 1 << 3,
226 // the object file's undefined references are bound by the
227 // dynamic linker when loaded.
228 MH_PREBOUND = 1 << 4,
229 // the file has its dynamic undefined references prebound
230 MH_SPLIT_SEGS = 1 << 5,
231 // the file has its read-only and read-write segments split
232 // see <mach/shared_memory_server.h>
233 MH_LAZY_INIT = 1 << 6,
234 // the shared library init routine is to be run lazily via
235 // catching memory faults to its writable segments (obsolete)
236 MH_TWOLEVEL = 1 << 7,
237 // the image is using two-level namespace bindings
238 MH_FORCE_FLAT = 1 << 8,
239 // the executable is forcing all images to use flat namespace
241 MH_NOMULTIDEFS = 1 << 8,
242 // this umbrella guarantees no multiple definitions of symbols
243 // in its sub-images so the two-level namespace hints can
245 MH_NOFIXPREBINDING = 1 << 10,
246 // do not have dyld notify the prebidning agent about this
248 MH_PREBINDABLE = 1 << 11,
249 // the binary is not prebound but can have its prebinding
250 // redone. only used when MH_PREBOUND is not set.
251 MH_ALLMODSBOUND = 1 << 12,
252 // indicates that this binary binds to all two-level namespace
253 // modules of its dependent libraries. Only used when
254 // MH_PREBINDABLE and MH_TWOLEVEL are both set.
255 MH_SUBSECTIONS_VIA_SYMBOLS = 1 << 13,
256 // safe to divide up the sections into sub-sections via symbols
257 // for dead code stripping.
258 MH_CANONICAL = 1 << 14,
259 // the binary has been canonicalized via the unprebind operation
260 MH_WEAK_DEFINES = 1 << 15,
261 // the final linked image contains external weak symbols
262 MH_BINDS_TO_WEAK = 1 << 16,
263 // the final linked image uses weak symbols
264 MH_ALLOW_STACK_EXECUTION = 1 << 17
265 // When this bit is set, all stacks in the task will be given
266 // stack execution privilege. Only used in MH_EXECUTE filetype
269 MachOHeader() : magic(0), cputype(0), cpusubtype(0), filetype(0),
270 ncmds(0), sizeofcmds(0), flags(0), reserved(0) { }
272 /// cmdSize - This routine returns the size of the MachOSection as written
273 /// to disk, depending on whether the destination is a 64 bit Mach-O file.
274 unsigned cmdSize(bool is64Bit) const {
276 return 8 * sizeof(uint32_t);
278 return 7 * sizeof(uint32_t);
281 /// setMagic - This routine sets the appropriate value for the 'magic'
282 /// field based on pointer size and endianness.
283 void setMagic(bool isLittleEndian, bool is64Bit) {
285 if (is64Bit) magic = 0xcffaedfe;
286 else magic = 0xcefaedfe;
288 if (is64Bit) magic = 0xfeedfacf;
289 else magic = 0xfeedface;
293 /// Header - An instance of MachOHeader that we will update while we build
294 /// the file, and then emit during finalization.
297 /// MachOSegment - This struct contains the necessary information to
298 /// emit the load commands for each section in the file.
299 struct MachOSegment {
300 uint32_t cmd; // LC_SEGMENT or LC_SEGMENT_64
301 uint32_t cmdsize; // Total size of this struct and section commands
302 std::string segname; // segment name
303 uint64_t vmaddr; // address of this segment
304 uint64_t vmsize; // size of this segment, may be larger than filesize
305 uint64_t fileoff; // offset in file
306 uint64_t filesize; // amount to read from file
307 uint32_t maxprot; // maximum VM protection
308 uint32_t initprot; // initial VM protection
309 uint32_t nsects; // number of sections in this segment
310 uint32_t flags; // flags
312 // The following constants are getting pulled in by one of the
313 // system headers, which creates a neat clash with the enum.
314 #if !defined(VM_PROT_NONE)
315 #define VM_PROT_NONE 0x00
317 #if !defined(VM_PROT_READ)
318 #define VM_PROT_READ 0x01
320 #if !defined(VM_PROT_WRITE)
321 #define VM_PROT_WRITE 0x02
323 #if !defined(VM_PROT_EXECUTE)
324 #define VM_PROT_EXECUTE 0x04
326 #if !defined(VM_PROT_ALL)
327 #define VM_PROT_ALL 0x07
330 // Constants for the vm protection fields
331 // see <mach-o/vm_prot.h>
332 enum { SEG_VM_PROT_NONE = VM_PROT_NONE,
333 SEG_VM_PROT_READ = VM_PROT_READ, // read permission
334 SEG_VM_PROT_WRITE = VM_PROT_WRITE, // write permission
335 SEG_VM_PROT_EXECUTE = VM_PROT_EXECUTE,
336 SEG_VM_PROT_ALL = VM_PROT_ALL
339 // Constants for the cmd field
340 // see <mach-o/loader.h>
341 enum { LC_SEGMENT = 0x01, // segment of this file to be mapped
342 LC_SEGMENT_64 = 0x19 // 64-bit segment of this file to be mapped
345 /// cmdSize - This routine returns the size of the MachOSection as written
346 /// to disk, depending on whether the destination is a 64 bit Mach-O file.
347 unsigned cmdSize(bool is64Bit) const {
349 return 6 * sizeof(uint32_t) + 4 * sizeof(uint64_t) + 16;
351 return 10 * sizeof(uint32_t) + 16; // addresses only 32 bits
354 MachOSegment(const std::string &seg, bool is64Bit)
355 : cmd(is64Bit ? LC_SEGMENT_64 : LC_SEGMENT), cmdsize(0), segname(seg),
356 vmaddr(0), vmsize(0), fileoff(0), filesize(0), maxprot(VM_PROT_ALL),
357 initprot(VM_PROT_ALL), nsects(0), flags(0) { }
360 /// MachORelocation - This struct contains information about each relocation
361 /// that needs to be emitted to the file.
362 /// see <mach-o/reloc.h>
363 struct MachORelocation {
364 uint32_t r_address; // offset in the section to what is being relocated
365 uint32_t r_symbolnum; // symbol index if r_extern == 1 else section index
366 bool r_pcrel; // was relocated pc-relative already
367 uint8_t r_length; // length = 2 ^ r_length
369 uint8_t r_type; // if not 0, machine-specific relocation type.
371 uint32_t getPackedFields() {
372 return (r_symbolnum << 8) | (r_pcrel << 7) | ((r_length & 3) << 5) |
373 (r_extern << 4) | (r_type & 15);
376 MachORelocation(uint32_t addr, uint32_t index, bool pcrel, uint8_t len,
377 bool ext, uint8_t type) : r_address(addr),
378 r_symbolnum(index), r_pcrel(pcrel), r_length(len), r_extern(ext),
382 /// MachOSection - This struct contains information about each section in a
383 /// particular segment that is emitted to the file. This is eventually
384 /// turned into the SectionCommand in the load command for a particlar
386 struct MachOSection {
387 std::string sectname; // name of this section,
388 std::string segname; // segment this section goes in
389 uint64_t addr; // memory address of this section
390 uint64_t size; // size in bytes of this section
391 uint32_t offset; // file offset of this section
392 uint32_t align; // section alignment (power of 2)
393 uint32_t reloff; // file offset of relocation entries
394 uint32_t nreloc; // number of relocation entries
395 uint32_t flags; // flags (section type and attributes)
396 uint32_t reserved1; // reserved (for offset or index)
397 uint32_t reserved2; // reserved (for count or sizeof)
398 uint32_t reserved3; // reserved (64 bit only)
400 /// A unique number for this section, which will be used to match symbols
401 /// to the correct section.
404 /// SectionData - The actual data for this section which we are building
405 /// up for emission to the file.
406 DataBuffer SectionData;
408 /// RelocBuffer - A buffer to hold the mach-o relocations before we write
409 /// them out at the appropriate location in the file.
410 DataBuffer RelocBuffer;
412 /// Relocations - The relocations that we have encountered so far in this
413 /// section that we will need to convert to MachORelocation entries when
414 /// the file is written.
415 std::vector<MachineRelocation> Relocations;
417 // Constants for the section types (low 8 bits of flags field)
418 // see <mach-o/loader.h>
419 enum { S_REGULAR = 0,
422 // zero fill on demand section
423 S_CSTRING_LITERALS = 2,
424 // section with only literal C strings
425 S_4BYTE_LITERALS = 3,
426 // section with only 4 byte literals
427 S_8BYTE_LITERALS = 4,
428 // section with only 8 byte literals
429 S_LITERAL_POINTERS = 5,
430 // section with only pointers to literals
431 S_NON_LAZY_SYMBOL_POINTERS = 6,
432 // section with only non-lazy symbol pointers
433 S_LAZY_SYMBOL_POINTERS = 7,
434 // section with only lazy symbol pointers
436 // section with only symbol stubs
437 // byte size of stub in the reserved2 field
438 S_MOD_INIT_FUNC_POINTERS = 9,
439 // section with only function pointers for initialization
440 S_MOD_TERM_FUNC_POINTERS = 10,
441 // section with only function pointers for termination
443 // section contains symbols that are coalesced
445 // zero fill on demand section (that can be larger than 4GB)
447 // section with only pairs of function pointers for interposing
448 S_16BYTE_LITERALS = 14
449 // section with only 16 byte literals
452 // Constants for the section flags (high 24 bits of flags field)
453 // see <mach-o/loader.h>
454 enum { S_ATTR_PURE_INSTRUCTIONS = 1 << 31,
455 // section contains only true machine instructions
456 S_ATTR_NO_TOC = 1 << 30,
457 // section contains coalesced symbols that are not to be in a
458 // ranlib table of contents
459 S_ATTR_STRIP_STATIC_SYMS = 1 << 29,
460 // ok to strip static symbols in this section in files with the
462 S_ATTR_NO_DEAD_STRIP = 1 << 28,
464 S_ATTR_LIVE_SUPPORT = 1 << 27,
465 // blocks are live if they reference live blocks
466 S_ATTR_SELF_MODIFYING_CODE = 1 << 26,
467 // used with i386 code stubs written on by dyld
468 S_ATTR_DEBUG = 1 << 25,
470 S_ATTR_SOME_INSTRUCTIONS = 1 << 10,
471 // section contains some machine instructions
472 S_ATTR_EXT_RELOC = 1 << 9,
473 // section has external relocation entries
474 S_ATTR_LOC_RELOC = 1 << 8
475 // section has local relocation entries
478 /// cmdSize - This routine returns the size of the MachOSection as written
479 /// to disk, depending on whether the destination is a 64 bit Mach-O file.
480 unsigned cmdSize(bool is64Bit) const {
482 return 7 * sizeof(uint32_t) + 2 * sizeof(uint64_t) + 32;
484 return 9 * sizeof(uint32_t) + 32; // addresses only 32 bits
487 MachOSection(const std::string &seg, const std::string §)
488 : sectname(sect), segname(seg), addr(0), size(0), offset(0), align(2),
489 reloff(0), nreloc(0), flags(0), reserved1(0), reserved2(0),
495 /// SectionList - This is the list of sections that we have emitted to the
496 /// file. Once the file has been completely built, the segment load command
497 /// SectionCommands are constructed from this info.
498 std::vector<MachOSection*> SectionList;
500 /// SectionLookup - This is a mapping from section name to SectionList entry
501 std::map<std::string, MachOSection*> SectionLookup;
503 /// GVSection - This is a mapping from a GlobalValue to a MachOSection,
504 /// to aid in emitting relocations.
505 std::map<GlobalValue*, MachOSection*> GVSection;
507 /// GVOffset - This is a mapping from a GlobalValue to an offset from the
508 /// start of the section in which the GV resides, to aid in emitting
510 std::map<GlobalValue*, intptr_t> GVOffset;
512 /// getSection - Return the section with the specified name, creating a new
513 /// section if one does not already exist.
514 MachOSection *getSection(const std::string &seg, const std::string §,
515 unsigned Flags = 0) {
516 MachOSection *MOS = SectionLookup[seg+sect];
519 MOS = new MachOSection(seg, sect);
520 SectionList.push_back(MOS);
521 MOS->Index = SectionList.size();
522 MOS->flags = MachOSection::S_REGULAR | Flags;
523 SectionLookup[seg+sect] = MOS;
526 MachOSection *getTextSection(bool isCode = true) {
528 return getSection("__TEXT", "__text",
529 MachOSection::S_ATTR_PURE_INSTRUCTIONS |
530 MachOSection::S_ATTR_SOME_INSTRUCTIONS);
532 return getSection("__TEXT", "__text");
534 MachOSection *getBSSSection() {
535 return getSection("__DATA", "__bss", MachOSection::S_ZEROFILL);
537 MachOSection *getDataSection() {
538 return getSection("__DATA", "__data");
540 MachOSection *getConstSection(const Type *Ty) {
541 // FIXME: support cstring literals and pointer literal
542 if (Ty->isPrimitiveType() || Ty->isInteger()) {
543 unsigned Size = TM.getTargetData()->getTypeSize(Ty);
545 default: break; // Fall through to __TEXT,__const
547 return getSection("__TEXT", "__literal4",
548 MachOSection::S_4BYTE_LITERALS);
550 return getSection("__TEXT", "__literal8",
551 MachOSection::S_8BYTE_LITERALS);
553 return getSection("__TEXT", "__literal16",
554 MachOSection::S_16BYTE_LITERALS);
557 return getSection("__TEXT", "__const");
559 MachOSection *getJumpTableSection() {
560 if (TM.getRelocationModel() == Reloc::PIC_)
561 return getTextSection(false);
563 return getSection("__TEXT", "__const");
566 /// MachOSymTab - This struct contains information about the offsets and
567 /// size of symbol table information.
570 uint32_t cmd; // LC_SYMTAB
571 uint32_t cmdsize; // sizeof( MachOSymTab )
572 uint32_t symoff; // symbol table offset
573 uint32_t nsyms; // number of symbol table entries
574 uint32_t stroff; // string table offset
575 uint32_t strsize; // string table size in bytes
577 // Constants for the cmd field
578 // see <mach-o/loader.h>
579 enum { LC_SYMTAB = 0x02 // link-edit stab symbol table info
582 MachOSymTab() : cmd(LC_SYMTAB), cmdsize(6 * sizeof(uint32_t)), symoff(0),
583 nsyms(0), stroff(0), strsize(0) { }
586 /// MachOSymTab - This struct contains information about the offsets and
587 /// size of symbol table information.
589 struct MachODySymTab {
590 uint32_t cmd; // LC_DYSYMTAB
591 uint32_t cmdsize; // sizeof( MachODySymTab )
592 uint32_t ilocalsym; // index to local symbols
593 uint32_t nlocalsym; // number of local symbols
594 uint32_t iextdefsym; // index to externally defined symbols
595 uint32_t nextdefsym; // number of externally defined symbols
596 uint32_t iundefsym; // index to undefined symbols
597 uint32_t nundefsym; // number of undefined symbols
598 uint32_t tocoff; // file offset to table of contents
599 uint32_t ntoc; // number of entries in table of contents
600 uint32_t modtaboff; // file offset to module table
601 uint32_t nmodtab; // number of module table entries
602 uint32_t extrefsymoff; // offset to referenced symbol table
603 uint32_t nextrefsyms; // number of referenced symbol table entries
604 uint32_t indirectsymoff; // file offset to the indirect symbol table
605 uint32_t nindirectsyms; // number of indirect symbol table entries
606 uint32_t extreloff; // offset to external relocation entries
607 uint32_t nextrel; // number of external relocation entries
608 uint32_t locreloff; // offset to local relocation entries
609 uint32_t nlocrel; // number of local relocation entries
611 // Constants for the cmd field
612 // see <mach-o/loader.h>
613 enum { LC_DYSYMTAB = 0x0B // dynamic link-edit symbol table info
616 MachODySymTab() : cmd(LC_DYSYMTAB), cmdsize(20 * sizeof(uint32_t)),
617 ilocalsym(0), nlocalsym(0), iextdefsym(0), nextdefsym(0),
618 iundefsym(0), nundefsym(0), tocoff(0), ntoc(0), modtaboff(0),
619 nmodtab(0), extrefsymoff(0), nextrefsyms(0), indirectsymoff(0),
620 nindirectsyms(0), extreloff(0), nextrel(0), locreloff(0), nlocrel(0) { }
623 /// SymTab - The "stab" style symbol table information
625 /// DySymTab - symbol table info for the dynamic link editor
626 MachODySymTab DySymTab;
629 // FIXME: this does not appear to be sorting 'f' after 'F'
630 bool operator()(const MachOSym &LHS, const MachOSym &RHS) {
631 return LHS.GVName < RHS.GVName;
635 /// PartitionByLocal - Simple boolean predicate that returns true if Sym is
636 /// a local symbol rather than an external symbol.
637 static bool PartitionByLocal(const MachOSym &Sym);
639 /// PartitionByDefined - Simple boolean predicate that returns true if Sym
640 /// is defined in this module.
641 static bool PartitionByDefined(const MachOSym &Sym);
645 /// SymbolTable - This is the list of symbols we have emitted to the file.
646 /// This actually gets rearranged before emission to the file (to put the
647 /// local symbols first in the list).
648 std::vector<MachOSym> SymbolTable;
650 /// SymT - A buffer to hold the symbol table before we write it out at the
651 /// appropriate location in the file.
654 /// StrT - A buffer to hold the string table before we write it out at the
655 /// appropriate location in the file.
658 /// PendingSyms - This is a list of externally defined symbols that we have
659 /// been asked to emit, but have not seen a reference to. When a reference
660 /// is seen, the symbol will move from this list to the SymbolTable.
661 std::vector<MachOSym> PendingSyms;
663 /// DynamicSymbolTable - This is just a vector of indices into
664 /// SymbolTable to aid in emitting the DYSYMTAB load command.
665 std::vector<unsigned> DynamicSymbolTable;
667 static void InitMem(const Constant *C, void *Addr, intptr_t Offset,
668 const TargetData *TD,
669 std::vector<MachineRelocation> &MRs);
672 void AddSymbolToSection(MachOSection *MOS, GlobalVariable *GV);
673 void EmitGlobal(GlobalVariable *GV);
674 void EmitHeaderAndLoadCommands();
676 void BufferSymbolAndStringTable();
677 void CalculateRelocations(MachOSection &MOS);
679 virtual MachineRelocation GetJTRelocation(unsigned Offset,
680 MachineBasicBlock *MBB) = 0;
681 virtual void GetTargetRelocation(MachineRelocation &MR, MachOSection &From,
682 MachOSection &To) = 0;