1 /* ----------------------------------------------------------------------- *
3 * Copyright 1996-2009 The NASM Authors - All Rights Reserved
4 * See the file AUTHORS included with the NASM distribution for
5 * the specific copyright holders.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
19 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
20 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
29 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
30 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 * ----------------------------------------------------------------------- */
35 * outmacho64.c output routines for the Netwide Assembler to produce
36 * NeXTstep/OpenStep/Rhapsody/Darwin/MacOS X (x86_64) object files
39 /* Most of this file is, like Mach-O itself, based on a.out. For more
40 * guidelines see outaout.c. */
54 #include "output/outform.h"
55 #include "output/outlib.h"
57 #if defined(OF_MACHO64)
59 /* Mach-O in-file header structure sizes */
60 #define MACHO_HEADER64_SIZE (32)
61 #define MACHO_SEGCMD64_SIZE (72)
62 #define MACHO_SECTCMD64_SIZE (80)
63 #define MACHO_SYMCMD_SIZE (24)
64 #define MACHO_NLIST64_SIZE (16)
65 #define MACHO_RELINFO64_SIZE (8)
67 /* Mach-O file header values */
68 #define MH_MAGIC_64 (0xfeedfacf)
69 #define CPU_TYPE_X86_64 (0x01000007) /* x86-64 platform */
70 #define CPU_SUBTYPE_I386_ALL (3) /* all-x86 compatible */
71 #define MH_OBJECT (0x1) /* object file */
73 #define LC_SEGMENT_64 (0x19) /* segment load command */
74 #define LC_SYMTAB (0x2) /* symbol table load command */
76 #define VM_PROT_NONE (0x00)
77 #define VM_PROT_READ (0x01)
78 #define VM_PROT_WRITE (0x02)
79 #define VM_PROT_EXECUTE (0x04)
81 #define VM_PROT_DEFAULT (VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE)
82 #define VM_PROT_ALL (VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE)
85 /* nasm internal data */
92 /* data that goes into the file */
93 char sectname
[16]; /* what this section is called */
94 char segname
[16]; /* segment this section will be in */
95 uint64_t addr
; /* in-memory address (subject to alignment) */
96 uint64_t size
; /* in-memory and -file size */
97 uint32_t nreloc
; /* relocation entry count */
98 uint32_t flags
; /* type and attributes (masked) */
99 uint32_t extreloc
; /* external relocations */
102 #define SECTION_TYPE 0x000000ff /* section type mask */
104 #define S_REGULAR (0x0) /* standard section */
105 #define S_ZEROFILL (0x1) /* zerofill, in-memory only */
107 #define SECTION_ATTRIBUTES_SYS 0x00ffff00 /* system setable attributes */
108 #define S_ATTR_SOME_INSTRUCTIONS 0x00000400 /* section contains some
109 machine instructions */
110 #define S_ATTR_EXT_RELOC 0x00000200 /* section has external
111 relocation entries */
112 #define S_ATTR_LOC_RELOC 0x00000100 /* section has local
113 relocation entries */
114 #define S_ATTR_PURE_INSTRUCTIONS 0x80000000 /* section uses pure
115 machine instructions */
117 static struct sectmap
{
118 const char *nasmsect
;
120 const char *sectname
;
123 {".text", "__TEXT", "__text", S_REGULAR
|S_ATTR_SOME_INSTRUCTIONS
|S_ATTR_PURE_INSTRUCTIONS
},
124 {".data", "__DATA", "__data", S_REGULAR
},
125 {".rodata", "__DATA", "__const", S_REGULAR
},
126 {".bss", "__DATA", "__bss", S_ZEROFILL
},
127 {NULL
, NULL
, NULL
, 0}
131 /* nasm internal data */
134 /* data that goes into the file */
135 int32_t addr
; /* op's offset in section */
136 uint32_t snum
:24, /* contains symbol index if
137 ** ext otherwise in-file
139 pcrel
:1, /* relative relocation */
140 length
:2, /* 0=byte, 1=word, 2=int32_t, 3=int64_t */
141 ext
:1, /* external symbol referenced */
142 type
:4; /* reloc type */
145 #define R_ABS 0 /* absolute relocation */
146 #define R_SCATTERED 0x80000000 /* reloc entry is scattered if
147 ** highest bit == 1 */
150 /* nasm internal data */
151 struct symbol
*next
; /* next symbol in the list */
152 char *name
; /* name of this symbol */
153 int32_t initial_snum
; /* symbol number used above in
155 int32_t snum
; /* true snum for reloc */
157 /* data that goes into the file */
158 uint32_t strx
; /* string table index */
159 uint8_t type
; /* symbol type */
160 uint8_t sect
; /* NO_SECT or section number */
161 uint16_t desc
; /* for stab debugging, 0 for us */
162 uint64_t value
; /* offset of symbol in section */
165 /* symbol type bits */
166 #define N_EXT 0x01 /* global or external symbol */
168 #define N_UNDF 0x0 /* undefined symbol | n_sect == */
169 #define N_ABS 0x2 /* absolute symbol | NO_SECT */
170 #define N_SECT 0xe /* defined symbol, n_sect holds
173 #define N_TYPE 0x0e /* type bit mask */
175 #define DEFAULT_SECTION_ALIGNMENT 0 /* byte (i.e. no) alignment */
177 /* special section number values */
178 #define NO_SECT 0 /* no section, invalid */
179 #define MAX_SECT 255 /* maximum number of sections */
181 static struct section
*sects
, **sectstail
;
182 static struct symbol
*syms
, **symstail
;
183 static uint32_t nsyms
;
185 /* These variables are set by macho_layout_symbols() to organize
186 the symbol table and string table in order the dynamic linker
187 expects. They are then used in macho_write() to put out the
188 symbols and strings in that order.
190 The order of the symbol table is:
192 defined external symbols (sorted by name)
193 undefined external symbols (sorted by name)
195 The order of the string table is:
196 strings for external symbols
197 strings for local symbols
199 static uint32_t ilocalsym
= 0;
200 static uint32_t iextdefsym
= 0;
201 static uint32_t iundefsym
= 0;
202 static uint32_t nlocalsym
;
203 static uint32_t nextdefsym
;
204 static uint32_t nundefsym
;
205 static struct symbol
**extdefsyms
= NULL
;
206 static struct symbol
**undefsyms
= NULL
;
208 static struct RAA
*extsyms
;
209 static struct SAA
*strs
;
210 static uint32_t strslen
;
212 extern struct ofmt of_macho64
;
214 /* Global file information. This should be cleaned up into either
215 a structure or as function arguments. */
216 uint32_t head_ncmds64
= 0;
217 uint32_t head_sizeofcmds64
= 0;
218 uint64_t seg_filesize64
= 0;
219 uint64_t seg_vmsize64
= 0;
220 uint32_t seg_nsects64
= 0;
221 uint64_t rel_padcnt64
= 0;
224 #define xstrncpy(xdst, xsrc) \
225 memset(xdst, '\0', sizeof(xdst)); /* zero out whole buffer */ \
226 strncpy(xdst, xsrc, sizeof(xdst)); /* copy over string */ \
227 xdst[sizeof(xdst) - 1] = '\0'; /* proper null-termination */
229 #define align(x, y) \
230 (((x) + (y) - 1) & ~((y) - 1)) /* align x to multiple of y */
232 #define alignint32_t(x) \
233 align(x, sizeof(int32_t)) /* align x to int32_t boundary */
235 #define alignint64_t(x) \
236 align(x, sizeof(int64_t)) /* align x to int64_t boundary */
238 static void debug_reloc (struct reloc
*);
239 static void debug_section_relocs (struct section
*) _unused
;
241 static int exact_log2 (uint32_t align
)
245 } else if (align
& (align
-1)) {
246 return -1; /* Not a power of 2 */
249 return __builtin_ctzl (align
);
253 /* We know exactly one bit is set at this point. */
254 if (align
& 0xffff0000)
256 if (align
& 0xff00ff00)
258 if (align
& 0xf0f0f0f0)
260 if (align
& 0xcccccccc)
262 if (align
& 0xaaaaaaaa)
270 static struct section
*get_section_by_name(const char *segname
,
271 const char *sectname
)
275 for (s
= sects
; s
!= NULL
; s
= s
->next
)
276 if (!strcmp(s
->segname
, segname
) && !strcmp(s
->sectname
, sectname
))
282 static struct section
*get_section_by_index(const int32_t index
)
286 for (s
= sects
; s
!= NULL
; s
= s
->next
)
287 if (index
== s
->index
)
293 static int32_t get_section_index_by_name(const char *segname
,
294 const char *sectname
)
298 for (s
= sects
; s
!= NULL
; s
= s
->next
)
299 if (!strcmp(s
->segname
, segname
) && !strcmp(s
->sectname
, sectname
))
305 static char *get_section_name_by_index(const int32_t index
)
309 for (s
= sects
; s
!= NULL
; s
= s
->next
)
310 if (index
== s
->index
)
316 static uint8_t get_section_fileindex_by_index(const int32_t index
)
321 for (s
= sects
; s
!= NULL
&& i
< MAX_SECT
; s
= s
->next
, ++i
)
322 if (index
== s
->index
)
326 nasm_error(ERR_WARNING
,
327 "too many sections (>255) - clipped by fileindex");
332 static struct symbol
*get_closest_section_symbol_by_offset(uint8_t fileindex
, int64_t offset
)
336 for (sym
= syms
; sym
!= NULL
; sym
= sym
->next
) {
337 if ((sym
->sect
!= NO_SECT
) &&
338 (sym
->sect
== fileindex
) &&
339 ((int64_t)sym
->value
>= offset
))
348 * Special section numbers which are used to define Mach-O special
349 * symbols, which can be used with WRT to provide PIC relocation
352 static int32_t macho_gotpcrel_sect
;
354 static void macho_init(void)
370 extsyms
= raa_init();
373 /* string table starts with a zero byte - don't ask why */
374 saa_wbytes(strs
, &zero
, sizeof(char));
377 /* add special symbol for ..gotpcrel */
378 macho_gotpcrel_sect
= seg_alloc();
379 macho_gotpcrel_sect
++;
380 define_label("..gotpcrel", macho_gotpcrel_sect
, 0L, NULL
, false, false);
383 static void sect_write(struct section
*sect
,
384 const uint8_t *data
, uint32_t len
)
386 saa_wbytes(sect
->data
, data
, len
);
390 static int32_t add_reloc(struct section
*sect
, int32_t section
,
391 int pcrel
, int bytes
, int64_t reloff
)
396 int32_t adjustment
= 0;
398 /* NeXT as puts relocs in reversed order (address-wise) into the
399 ** files, so we do the same, doesn't seem to make much of a
400 ** difference either way */
401 r
= nasm_malloc(sizeof(struct reloc
));
402 r
->next
= sect
->relocs
;
405 /* the current end of the section will be the symbol's address for
406 ** now, might have to be fixed by macho_fixup_relocs() later on. make
407 ** sure we don't make the symbol scattered by setting the highest
408 ** bit by accident */
409 r
->addr
= sect
->size
& ~R_SCATTERED
;
411 r
->pcrel
= (pcrel
? 1 : 0);
413 /* match byte count 1, 2, 4, 8 to length codes 0, 1, 2, 3 respectively */
431 /* set default relocation values */
432 r
->type
= 0; // X86_64_RELOC_UNSIGNED
433 r
->snum
= R_ABS
; // Absolute Symbol (indicates no relocation)
435 /* absolute relocation */
439 if (section
== NO_SEG
) {
440 // r->snum = R_ABS; // Set above
444 fi
= get_section_fileindex_by_index(section
);
448 r
->snum
= raa_read(extsyms
, section
);
452 sym
= get_closest_section_symbol_by_offset(fi
, reloff
);
453 r
->snum
= sym
->initial_snum
;
454 adjustment
= sym
->value
;
458 /* relative relocation */
459 } else if (pcrel
== 1) {
462 if (section
== NO_SEG
) {
463 r
->type
= 1; // X86_64_RELOC_SIGNED
467 r
->type
= 2; // X86_64_RELOC_BRANCH
468 fi
= get_section_fileindex_by_index(section
);
473 r
->snum
= raa_read(extsyms
, section
);
477 sym
= get_closest_section_symbol_by_offset(fi
, reloff
);
478 r
->snum
= sym
->initial_snum
;
479 adjustment
= sym
->value
;
484 } else if (pcrel
== 2) {
486 r
->type
= 5; // X86_64_RELOC_SUBTRACTOR
489 } else if (pcrel
== 3) {
490 r
->type
= 4; // X86_64_RELOC_GOT
491 r
->snum
= macho_gotpcrel_sect
;
493 /* gotpcrel MOVQ load */
494 } else if (pcrel
== 4) {
495 r
->type
= 3; // X86_64_RELOC_GOT_LOAD
496 r
->snum
= macho_gotpcrel_sect
;
504 static void macho_output(int32_t secto
, const void *data
,
505 enum out_type type
, uint64_t size
,
506 int32_t section
, int32_t wrt
)
508 struct section
*s
, *sbss
;
510 uint8_t mydata
[16], *p
, gotload
;
512 if (secto
== NO_SEG
) {
513 if (type
!= OUT_RESERVE
)
514 nasm_error(ERR_NONFATAL
, "attempt to assemble code in "
520 s
= get_section_by_index(secto
);
523 nasm_error(ERR_WARNING
, "attempt to assemble code in"
524 " section %d: defaulting to `.text'", secto
);
525 s
= get_section_by_name("__TEXT", "__text");
527 /* should never happen */
529 nasm_error(ERR_PANIC
, "text section not found");
532 sbss
= get_section_by_name("__DATA", "__bss");
534 if (s
== sbss
&& type
!= OUT_RESERVE
) {
535 nasm_error(ERR_WARNING
, "attempt to initialize memory in the"
536 " BSS section: ignored");
537 s
->size
+= realsize(type
, size
);
544 nasm_error(ERR_WARNING
, "uninitialized space declared in"
545 " %s section: zeroing",
546 get_section_name_by_index(secto
));
548 sect_write(s
, NULL
, size
);
555 if (section
!= NO_SEG
)
556 nasm_error(ERR_PANIC
, "OUT_RAWDATA with other than NO_SEG");
558 sect_write(s
, data
, size
);
562 addr
= *(int64_t *)data
;
563 if (section
!= NO_SEG
) {
565 nasm_error(ERR_NONFATAL
, "Mach-O format does not support"
566 " section base references");
570 nasm_error(ERR_NONFATAL
, "Mach-O 64-bit format does not support"
571 " 32-bit absolute addresses");
573 Seemingly, Mach-O's X86_64_RELOC_SUBTRACTOR would require
574 pre-determined knowledge of where the image base would be,
575 making it impractical for use in intermediate object files
578 addr
-= add_reloc(s
, section
, 0, size
, addr
); // X86_64_RELOC_UNSIGNED
581 nasm_error(ERR_NONFATAL
, "Mach-O format does not support"
588 WRITEADDR(p
, addr
, size
);
589 sect_write(s
, mydata
, size
);
594 WRITESHORT(p
, *(int64_t *)data
);
596 if (section
== secto
)
597 nasm_error(ERR_PANIC
, "intra-section OUT_REL2ADR");
599 if (section
== NO_SEG
) {
601 } else if (section
% 2) {
602 nasm_error(ERR_NONFATAL
, "Mach-O format does not support"
603 " section base references");
605 nasm_error(ERR_NONFATAL
, "Unsupported non-32-bit"
606 " Macho-O relocation [2]");
609 sect_write(s
, mydata
, 2L);
614 WRITELONG(p
, *(int64_t *)data
);
616 if (section
== secto
)
617 nasm_error(ERR_PANIC
, "intra-section OUT_REL4ADR");
619 if (section
!= NO_SEG
&& section
% 2) {
620 nasm_error(ERR_NONFATAL
, "Mach-O format does not support"
621 " section base references");
624 *mydata
-= add_reloc(s
, section
, 1, 4, (int64_t)*mydata
); // X86_64_RELOC_SIGNED/BRANCH
625 } else if (wrt
== macho_gotpcrel_sect
) {
626 if (s
->data
->datalen
> 1) {
627 saa_fread(s
->data
, s
->data
->datalen
-2, &gotload
, 1); // Retrieve Instruction Opcode
631 if (gotload
== 0x8B) { // Check for MOVQ Opcode
632 *mydata
-= add_reloc(s
, section
, 4, 4, (int64_t)*mydata
); // X86_64_GOT_LOAD (MOVQ load)
634 *mydata
-= add_reloc(s
, section
, 3, 4, (int64_t)*mydata
); // X86_64_GOT
637 nasm_error(ERR_NONFATAL
, "Mach-O format does not support"
639 wrt
= NO_SEG
; /* we can at least _try_ to continue */
643 sect_write(s
, mydata
, 4L);
647 nasm_error(ERR_PANIC
, "unknown output type?");
652 static int32_t macho_section(char *name
, int pass
, int *bits
)
654 int32_t index
, originalIndex
;
655 char *sectionAttributes
;
661 /* Default to 64 bits. */
665 sectionAttributes
= NULL
;
667 sectionAttributes
= name
;
668 name
= nasm_strsep(§ionAttributes
, " \t");
671 for (sm
= sectmap
; sm
->nasmsect
!= NULL
; ++sm
) {
672 /* make lookup into section name translation table */
673 if (!strcmp(name
, sm
->nasmsect
)) {
674 char *currentAttribute
;
676 /* try to find section with that name */
677 originalIndex
= index
= get_section_index_by_name(sm
->segname
,
680 /* create it if it doesn't exist yet */
682 s
= *sectstail
= nasm_malloc(sizeof(struct section
));
684 sectstail
= &s
->next
;
686 s
->data
= saa_init(1L);
687 s
->index
= seg_alloc();
691 xstrncpy(s
->segname
, sm
->segname
);
692 xstrncpy(s
->sectname
, sm
->sectname
);
695 s
->flags
= sm
->flags
;
699 s
= get_section_by_index(index
);
702 while ((NULL
!= sectionAttributes
)
703 && (currentAttribute
= nasm_strsep(§ionAttributes
, " \t"))) {
704 if (0 != *currentAttribute
) {
705 if (!nasm_strnicmp("align=", currentAttribute
, 6)) {
707 int newAlignment
, value
;
709 value
= strtoul(currentAttribute
+ 6, (char**)&end
, 0);
710 newAlignment
= exact_log2(value
);
713 nasm_error(ERR_PANIC
,
714 "unknown or missing alignment value \"%s\" "
715 "specified for section \"%s\"",
716 currentAttribute
+ 6,
719 } else if (0 > newAlignment
) {
720 nasm_error(ERR_PANIC
,
721 "alignment of %d (for section \"%s\") is not "
728 if ((-1 != originalIndex
)
729 && (s
->align
!= newAlignment
)
730 && (s
->align
!= -1)) {
731 nasm_error(ERR_PANIC
,
732 "section \"%s\" has already been specified "
733 "with alignment %d, conflicts with new "
741 s
->align
= newAlignment
;
742 } else if (!nasm_stricmp("data", currentAttribute
)) {
743 /* Do nothing; 'data' is implicit */
745 nasm_error(ERR_PANIC
,
746 "unknown section attribute %s for section %s",
758 nasm_error(ERR_PANIC
, "invalid section name %s", name
);
762 static void macho_symdef(char *name
, int32_t section
, int64_t offset
,
763 int is_global
, char *special
)
768 nasm_error(ERR_NONFATAL
, "The Mach-O output format does "
769 "not support any special symbol types");
773 if (is_global
== 3) {
774 nasm_error(ERR_NONFATAL
, "The Mach-O format does not "
775 "(yet) support forward reference fixups.");
779 if (name
[0] == '.' && name
[1] == '.' && name
[2] != '@') {
781 * This is a NASM special symbol. We never allow it into
782 * the Macho-O symbol table, even if it's a valid one. If it
783 * _isn't_ a valid one, we should barf immediately.
785 if (strcmp(name
, "..gotpcrel"))
786 nasm_error(ERR_NONFATAL
, "unrecognized special symbol `%s'", name
);
790 sym
= *symstail
= nasm_malloc(sizeof(struct symbol
));
792 symstail
= &sym
->next
;
799 sym
->initial_snum
= -1;
801 /* external and common symbols get N_EXT */
802 if (is_global
!= 0) {
806 if (section
== NO_SEG
) {
807 /* symbols in no section get absolute */
813 /* get the in-file index of the section the symbol was defined in */
814 sym
->sect
= get_section_fileindex_by_index(section
);
816 /* track the initially allocated symbol number for use in future fix-ups */
817 sym
->initial_snum
= nsyms
;
819 if (sym
->sect
== NO_SECT
) {
821 /* remember symbol number of references to external
822 ** symbols, this works because every external symbol gets
823 ** its own section number allocated internally by nasm and
824 ** can so be used as a key */
825 extsyms
= raa_write(extsyms
, section
, nsyms
);
830 /* there isn't actually a difference between global
831 ** and common symbols, both even have their size in
837 /* give an error on unfound section if it's not an
838 ** external or common symbol (assemble_file() does a
839 ** seg_alloc() on every call for them) */
840 nasm_error(ERR_PANIC
, "in-file index for section %d not found",
848 static int32_t macho_segbase(int32_t section
)
853 static void macho_filename(char *inname
, char *outname
)
855 standard_extension(inname
, outname
, ".o");
858 extern macros_t macho_stdmac
[];
860 /* Comparison function for qsort symbol layout. */
861 static int layout_compare (const struct symbol
**s1
,
862 const struct symbol
**s2
)
864 return (strcmp ((*s1
)->name
, (*s2
)->name
));
867 /* The native assembler does a few things in a similar function
869 * Remove temporary labels
870 * Sort symbols according to local, external, undefined (by name)
871 * Order the string table
873 We do not remove temporary labels right now.
875 numsyms is the total number of symbols we have. strtabsize is the
876 number entries in the string table. */
878 static void macho_layout_symbols (uint32_t *numsyms
,
879 uint32_t *strtabsize
)
881 struct symbol
*sym
, **symp
;
885 *strtabsize
= sizeof (char);
889 while ((sym
= *symp
)) {
890 /* Undefined symbols are now external. */
891 if (sym
->type
== N_UNDF
)
894 if ((sym
->type
& N_EXT
) == 0) {
895 sym
->snum
= *numsyms
;
896 *numsyms
= *numsyms
+ 1;
900 if ((sym
->type
& N_TYPE
) != N_UNDF
) {
906 /* If we handle debug info we'll want
907 to check for it here instead of just
908 adding the symbol to the string table. */
909 sym
->strx
= *strtabsize
;
910 saa_wbytes (strs
, sym
->name
, (int32_t)(strlen(sym
->name
) + 1));
911 *strtabsize
+= strlen(sym
->name
) + 1;
916 /* Next, sort the symbols. Most of this code is a direct translation from
917 the Apple cctools symbol layout. We need to keep compatibility with that. */
918 /* Set the indexes for symbol groups into the symbol table */
920 iextdefsym
= nlocalsym
;
921 iundefsym
= nlocalsym
+ nextdefsym
;
923 /* allocate arrays for sorting externals by name */
924 extdefsyms
= nasm_malloc(nextdefsym
* sizeof(struct symbol
*));
925 undefsyms
= nasm_malloc(nundefsym
* sizeof(struct symbol
*));
932 while ((sym
= *symp
)) {
934 if((sym
->type
& N_EXT
) == 0) {
935 sym
->strx
= *strtabsize
;
936 saa_wbytes (strs
, sym
->name
, (int32_t)(strlen (sym
->name
) + 1));
937 *strtabsize
+= strlen(sym
->name
) + 1;
940 if((sym
->type
& N_TYPE
) != N_UNDF
) {
941 extdefsyms
[i
++] = sym
;
943 undefsyms
[j
++] = sym
;
949 qsort(extdefsyms
, nextdefsym
, sizeof(struct symbol
*),
950 (int (*)(const void *, const void *))layout_compare
);
951 qsort(undefsyms
, nundefsym
, sizeof(struct symbol
*),
952 (int (*)(const void *, const void *))layout_compare
);
954 for(i
= 0; i
< nextdefsym
; i
++) {
955 extdefsyms
[i
]->snum
= *numsyms
;
958 for(j
= 0; j
< nundefsym
; j
++) {
959 undefsyms
[j
]->snum
= *numsyms
;
964 /* Calculate some values we'll need for writing later. */
966 static void macho_calculate_sizes (void)
970 /* count sections and calculate in-memory and in-file offsets */
971 for (s
= sects
; s
!= NULL
; s
= s
->next
) {
974 /* zerofill sections aren't actually written to the file */
975 if ((s
->flags
& SECTION_TYPE
) != S_ZEROFILL
)
976 seg_filesize64
+= s
->size
;
978 /* recalculate segment address based on alignment and vm size */
979 s
->addr
= seg_vmsize64
;
980 /* we need section alignment to calculate final section address */
982 s
->align
= DEFAULT_SECTION_ALIGNMENT
;
984 uint64_t newaddr
= align(s
->addr
, 1 << s
->align
);
985 pad
= newaddr
- s
->addr
;
989 seg_vmsize64
+= s
->size
+ pad
;
993 /* calculate size of all headers, load commands and sections to
994 ** get a pointer to the start of all the raw data */
995 if (seg_nsects64
> 0) {
998 MACHO_SEGCMD64_SIZE
+ seg_nsects64
* MACHO_SECTCMD64_SIZE
;
1003 head_sizeofcmds64
+= MACHO_SYMCMD_SIZE
;
1007 /* Write out the header information for the file. */
1009 static void macho_write_header (void)
1011 fwriteint32_t(MH_MAGIC_64
, ofile
); /* magic */
1012 fwriteint32_t(CPU_TYPE_X86_64
, ofile
); /* CPU type */
1013 fwriteint32_t(CPU_SUBTYPE_I386_ALL
, ofile
); /* CPU subtype */
1014 fwriteint32_t(MH_OBJECT
, ofile
); /* Mach-O file type */
1015 fwriteint32_t(head_ncmds64
, ofile
); /* number of load commands */
1016 fwriteint32_t(head_sizeofcmds64
, ofile
); /* size of load commands */
1017 fwriteint32_t(0, ofile
); /* no flags */
1018 fwriteint32_t(0, ofile
); /* reserved for future use */
1021 /* Write out the segment load command at offset. */
1023 static uint32_t macho_write_segment (uint64_t offset
)
1025 uint64_t rel_base
= alignint64_t (offset
+ seg_filesize64
);
1026 uint32_t s_reloff
= 0;
1029 fwriteint32_t(LC_SEGMENT_64
, ofile
); /* cmd == LC_SEGMENT_64 */
1031 /* size of load command including section load commands */
1032 fwriteint32_t(MACHO_SEGCMD64_SIZE
+ seg_nsects64
*
1033 MACHO_SECTCMD64_SIZE
, ofile
);
1035 /* in an MH_OBJECT file all sections are in one unnamed (name
1036 ** all zeros) segment */
1037 fwritezero(16, ofile
);
1038 fwriteint64_t(0, ofile
); /* in-memory offset */
1039 fwriteint64_t(seg_vmsize64
, ofile
); /* in-memory size */
1040 fwriteint64_t(offset
, ofile
); /* in-file offset to data */
1041 fwriteint64_t(seg_filesize64
, ofile
); /* in-file size */
1042 fwriteint32_t(VM_PROT_DEFAULT
, ofile
); /* maximum vm protection */
1043 fwriteint32_t(VM_PROT_DEFAULT
, ofile
); /* initial vm protection */
1044 fwriteint32_t(seg_nsects64
, ofile
); /* number of sections */
1045 fwriteint32_t(0, ofile
); /* no flags */
1047 /* emit section headers */
1048 for (s
= sects
; s
!= NULL
; s
= s
->next
) {
1049 fwrite(s
->sectname
, sizeof(s
->sectname
), 1, ofile
);
1050 fwrite(s
->segname
, sizeof(s
->segname
), 1, ofile
);
1051 fwriteint64_t(s
->addr
, ofile
);
1052 fwriteint64_t(s
->size
, ofile
);
1054 /* dummy data for zerofill sections or proper values */
1055 if ((s
->flags
& SECTION_TYPE
) != S_ZEROFILL
) {
1056 fwriteint32_t(offset
, ofile
);
1057 /* Write out section alignment, as a power of two.
1058 e.g. 32-bit word alignment would be 2 (2^2 = 4). */
1060 s
->align
= DEFAULT_SECTION_ALIGNMENT
;
1061 fwriteint32_t(s
->align
, ofile
);
1062 /* To be compatible with cctools as we emit
1063 a zero reloff if we have no relocations. */
1064 fwriteint32_t(s
->nreloc
? rel_base
+ s_reloff
: 0, ofile
);
1065 fwriteint32_t(s
->nreloc
, ofile
);
1068 s_reloff
+= s
->nreloc
* MACHO_RELINFO64_SIZE
;
1070 fwriteint32_t(0, ofile
);
1071 fwriteint32_t(0, ofile
);
1072 fwriteint32_t(0, ofile
);
1073 fwriteint32_t(0, ofile
);
1077 s
->flags
|= S_ATTR_LOC_RELOC
;
1079 s
->flags
|= S_ATTR_EXT_RELOC
;
1082 fwriteint32_t(s
->flags
, ofile
); /* flags */
1083 fwriteint32_t(0, ofile
); /* reserved */
1084 fwriteint32_t(0, ofile
); /* reserved */
1086 fwriteint32_t(0, ofile
); /* align */
1089 rel_padcnt64
= rel_base
- offset
;
1090 offset
= rel_base
+ s_reloff
;
1095 /* For a given chain of relocs r, write out the entire relocation
1096 chain to the object file. */
1098 static void macho_write_relocs (struct reloc
*r
)
1103 fwriteint32_t(r
->addr
, ofile
); /* reloc offset */
1106 word2
|= r
->pcrel
<< 24;
1107 word2
|= r
->length
<< 25;
1108 word2
|= r
->ext
<< 27;
1109 word2
|= r
->type
<< 28;
1110 fwriteint32_t(word2
, ofile
); /* reloc data */
1115 /* Write out the section data. */
1116 static void macho_write_section (void)
1118 struct section
*s
, *s2
;
1120 uint8_t fi
, *p
, *q
, blk
[8];
1124 for (s
= sects
; s
!= NULL
; s
= s
->next
) {
1125 if ((s
->flags
& SECTION_TYPE
) == S_ZEROFILL
)
1128 /* no padding needs to be done to the sections */
1130 /* Like a.out Mach-O references things in the data or bss
1131 * sections by addresses which are actually relative to the
1132 * start of the _text_ section, in the _file_. See outaout.c
1133 * for more information. */
1134 saa_rewind(s
->data
);
1135 for (r
= s
->relocs
; r
!= NULL
; r
= r
->next
) {
1136 len
= (int32_t)r
->length
<< 1;
1137 if(len
> 4) len
= 8;
1138 saa_fread(s
->data
, r
->addr
, blk
, len
);
1142 /* get offset based on relocation type */
1143 if (r
->length
> 0) {
1144 l
+= ((int64_t)*p
++) << 8;
1146 if (r
->length
> 1) {
1147 l
+= ((int64_t)*p
++) << 16;
1148 l
+= ((int64_t)*p
++) << 24;
1151 if (r
->length
> 2) {
1152 l
+= ((int64_t)*p
++) << 32;
1153 l
+= ((int64_t)*p
++) << 40;
1154 l
+= ((int64_t)*p
++) << 48;
1155 l
+= ((int64_t)*p
++) << 56;
1161 /* If the relocation is internal add to the current section
1162 offset. Otherwise the only value we need is the symbol
1163 offset which we already have. The linker takes care
1164 of the rest of the address. */
1166 /* generate final address by section address and offset */
1167 for (s2
= sects
, fi
= 1;
1168 s2
!= NULL
; s2
= s2
->next
, fi
++) {
1169 if (fi
== r
->snum
) {
1176 /* write new offset back */
1179 else if (r
->length
== 2)
1181 else if (r
->length
== 1)
1186 saa_fwrite(s
->data
, r
->addr
, blk
, len
);
1189 /* dump the section data to file */
1190 saa_fpwrite(s
->data
, ofile
);
1193 /* pad last section up to reloc entries on int64_t boundary */
1194 fwritezero(rel_padcnt64
, ofile
);
1196 /* emit relocation entries */
1197 for (s
= sects
; s
!= NULL
; s
= s
->next
)
1198 macho_write_relocs (s
->relocs
);
1201 /* Write out the symbol table. We should already have sorted this
1203 static void macho_write_symtab (void)
1210 /* we don't need to pad here since MACHO_RELINFO_SIZE == 8 */
1212 for (sym
= syms
; sym
!= NULL
; sym
= sym
->next
) {
1213 if ((sym
->type
& N_EXT
) == 0) {
1214 fwriteint32_t(sym
->strx
, ofile
); /* string table entry number */
1215 fwrite(&sym
->type
, 1, 1, ofile
); /* symbol type */
1216 fwrite(&sym
->sect
, 1, 1, ofile
); /* section */
1217 fwriteint16_t(sym
->desc
, ofile
); /* description */
1219 /* Fix up the symbol value now that we know the final section
1221 if (((sym
->type
& N_TYPE
) == N_SECT
) && (sym
->sect
!= NO_SECT
)) {
1222 for (s
= sects
, fi
= 1;
1223 s
!= NULL
&& fi
< sym
->sect
; s
= s
->next
, ++fi
)
1224 sym
->value
+= s
->size
;
1227 fwriteint64_t(sym
->value
, ofile
); /* value (i.e. offset) */
1231 for (i
= 0; i
< nextdefsym
; i
++) {
1232 sym
= extdefsyms
[i
];
1233 fwriteint32_t(sym
->strx
, ofile
);
1234 fwrite(&sym
->type
, 1, 1, ofile
); /* symbol type */
1235 fwrite(&sym
->sect
, 1, 1, ofile
); /* section */
1236 fwriteint16_t(sym
->desc
, ofile
); /* description */
1238 /* Fix up the symbol value now that we know the final section
1240 if (((sym
->type
& N_TYPE
) == N_SECT
) && (sym
->sect
!= NO_SECT
)) {
1241 for (s
= sects
, fi
= 1;
1242 s
!= NULL
&& fi
< sym
->sect
; s
= s
->next
, ++fi
)
1243 sym
->value
+= s
->size
;
1246 fwriteint64_t(sym
->value
, ofile
); /* value (i.e. offset) */
1249 for (i
= 0; i
< nundefsym
; i
++) {
1251 fwriteint32_t(sym
->strx
, ofile
);
1252 fwrite(&sym
->type
, 1, 1, ofile
); /* symbol type */
1253 fwrite(&sym
->sect
, 1, 1, ofile
); /* section */
1254 fwriteint16_t(sym
->desc
, ofile
); /* description */
1256 // Fix up the symbol value now that we know the final section sizes.
1257 if (((sym
->type
& N_TYPE
) == N_SECT
) && (sym
->sect
!= NO_SECT
)) {
1258 for (s
= sects
, fi
= 1;
1259 s
!= NULL
&& fi
< sym
->sect
; s
= s
->next
, ++fi
)
1260 sym
->value
+= s
->size
;
1263 fwriteint64_t(sym
->value
, ofile
); // value (i.e. offset)
1268 /* Fixup the snum in the relocation entries, we should be
1269 doing this only for externally referenced symbols. */
1270 static void macho_fixup_relocs (struct reloc
*r
)
1276 for (sym
= syms
; sym
!= NULL
; sym
= sym
->next
) {
1277 if (sym
->initial_snum
== r
->snum
) {
1278 r
->snum
= sym
->snum
;
1287 /* Write out the object file. */
1289 static void macho_write (void)
1291 uint64_t offset
= 0;
1293 /* mach-o object file structure:
1299 ** uint32_t mach file type
1300 ** uint32_t number of load commands
1301 ** uint32_t size of all load commands
1302 ** (includes section struct size of segment command)
1306 ** uint32_t command type == LC_SEGMENT_64
1307 ** uint32_t size of load command
1308 ** (including section load commands)
1309 ** char[16] segment name
1310 ** uint64_t in-memory offset
1311 ** uint64_t in-memory size
1312 ** uint64_t in-file offset to data area
1313 ** uint64_t in-file size
1314 ** (in-memory size excluding zerofill sections)
1315 ** int maximum vm protection
1316 ** int initial vm protection
1317 ** uint32_t number of sections
1321 ** char[16] section name
1322 ** char[16] segment name
1323 ** uint64_t in-memory offset
1324 ** uint64_t in-memory size
1325 ** uint32_t in-file offset
1326 ** uint32_t alignment
1327 ** (irrelevant in MH_OBJECT)
1328 ** uint32_t in-file offset of relocation entires
1329 ** uint32_t number of relocations
1331 ** uint32_t reserved
1332 ** uint32_t reserved
1334 ** symbol table command
1335 ** uint32_t command type == LC_SYMTAB
1336 ** uint32_t size of load command
1337 ** uint32_t symbol table offset
1338 ** uint32_t number of symbol table entries
1339 ** uint32_t string table offset
1340 ** uint32_t string table size
1344 ** padding to int64_t boundary
1346 ** relocation data (struct reloc)
1348 ** uint data (symbolnum, pcrel, length, extern, type)
1350 ** symbol table data (struct nlist)
1351 ** int32_t string table entry number
1353 ** (extern, absolute, defined in section)
1355 ** (0 for global symbols, section number of definition (>= 1, <=
1356 ** 254) for local symbols, size of variable for common symbols
1357 ** [type == extern])
1358 ** int16_t description
1359 ** (for stab debugging format)
1360 ** uint64_t value (i.e. file offset) of symbol or stab offset
1362 ** string table data
1363 ** list of null-terminated strings
1366 /* Emit the Mach-O header. */
1367 macho_write_header();
1369 offset
= MACHO_HEADER64_SIZE
+ head_sizeofcmds64
;
1371 /* emit the segment load command */
1372 if (seg_nsects64
> 0)
1373 offset
= macho_write_segment (offset
);
1375 nasm_error(ERR_WARNING
, "no sections?");
1378 /* write out symbol command */
1379 fwriteint32_t(LC_SYMTAB
, ofile
); /* cmd == LC_SYMTAB */
1380 fwriteint32_t(MACHO_SYMCMD_SIZE
, ofile
); /* size of load command */
1381 fwriteint32_t(offset
, ofile
); /* symbol table offset */
1382 fwriteint32_t(nsyms
, ofile
); /* number of symbol
1385 offset
+= nsyms
* MACHO_NLIST64_SIZE
;
1386 fwriteint32_t(offset
, ofile
); /* string table offset */
1387 fwriteint32_t(strslen
, ofile
); /* string table size */
1390 /* emit section data */
1391 if (seg_nsects64
> 0)
1392 macho_write_section ();
1394 /* emit symbol table if we have symbols */
1396 macho_write_symtab ();
1398 /* we don't need to pad here since MACHO_NLIST64_SIZE == 16 */
1400 /* emit string table */
1401 saa_fpwrite(strs
, ofile
);
1403 /* We do quite a bit here, starting with finalizing all of the data
1404 for the object file, writing, and then freeing all of the data from
1407 static void macho_cleanup(int debuginfo
)
1415 /* Sort all symbols. */
1416 macho_layout_symbols (&nsyms
, &strslen
);
1418 /* Fixup relocation entries */
1419 for (s
= sects
; s
!= NULL
; s
= s
->next
) {
1420 macho_fixup_relocs (s
->relocs
);
1423 /* First calculate and finalize needed values. */
1424 macho_calculate_sizes();
1427 /* free up everything */
1428 while (sects
->next
) {
1430 sects
= sects
->next
;
1433 while (s
->relocs
!= NULL
) {
1435 s
->relocs
= s
->relocs
->next
;
1446 while (syms
->next
) {
1455 /* Debugging routines. */
1456 static void debug_reloc (struct reloc
*r
)
1458 fprintf (stdout
, "reloc:\n");
1459 fprintf (stdout
, "\taddr: %"PRId32
"\n", r
->addr
);
1460 fprintf (stdout
, "\tsnum: %d\n", r
->snum
);
1461 fprintf (stdout
, "\tpcrel: %d\n", r
->pcrel
);
1462 fprintf (stdout
, "\tlength: %d\n", r
->length
);
1463 fprintf (stdout
, "\text: %d\n", r
->ext
);
1464 fprintf (stdout
, "\ttype: %d\n", r
->type
);
1467 static void debug_section_relocs (struct section
*s
)
1469 struct reloc
*r
= s
->relocs
;
1471 fprintf (stdout
, "relocs for section %s:\n\n", s
->sectname
);
1479 struct ofmt of_macho64
= {
1480 "NeXTstep/OpenStep/Rhapsody/Darwin/MacOS X (x86_64) object files",