step toward darwin ffi: factor out macho code

R=r
DELTA=771  (374 added, 287 deleted, 110 changed)
OCL=35187
CL=35187

12 files changed, 478 insertions, 391 deletions

diff --git a/src/cmd/6l/Makefile b/src/cmd/6l/Makefile
index 7952f754d..4821f9d91 100644
--- a/src/cmd/6l/Makefile
+++ b/src/cmd/6l/Makefile
@@ -14,6 +14,7 @@ OFILES=\
 	enam.$O\
 	go.$O\
 	list.$O\
+	macho.$O\
 	obj.$O\
 	optab.$O\
 	pass.$O\
@@ -23,6 +24,7 @@ HFILES=\
 	l.h\
 	../6l/6.out.h\
 	../ld/elf.h\
+	../ld/macho.h\
 	../6l/compat.h\
 
 
@@ -41,5 +43,5 @@ install: $(TARG)
 	cp $(TARG) $(GOBIN)/$(TARG)
 
 go.o: ../ld/go.c
-
 elf.o: ../ld/elf.c
+macho.o: ../ld/macho.c
diff --git a/src/cmd/6l/asm.c b/src/cmd/6l/asm.c
index 48a7bae4e..5562ee4e3 100644
--- a/src/cmd/6l/asm.c
+++ b/src/cmd/6l/asm.c
@@ -30,6 +30,7 @@
 
 #include	"l.h"
 #include	"../ld/elf.h"
+#include	"../ld/macho.h"
 
 #define	Dbufslop	100
 
@@ -422,13 +423,18 @@ asmb(void)
 {
 	Prog *p;
 	int32 v, magic;
-	int a, nl, dynsym;
+	int a, dynsym;
 	uchar *op1;
 	vlong vl, va, startva, fo, w, symo;
 	vlong symdatva = 0x99LL<<32;
 	ElfEhdr *eh;
 	ElfPhdr *ph, *pph;
 	ElfShdr *sh;
+	MachoHdr *mh;
+	MachoSect *msect;
+	MachoSeg *ms;
+	MachoDebug *md;
+	MachoLoad *ml;
 
 	if(debug['v'])
 		Bprint(&bso, "%5.2f asmb\n", cputime());
@@ -602,71 +608,91 @@ asmb(void)
 		break;
 	case 6:
 		/* apple MACH */
-		va = 4096;
-
-		lputl(0xfeedfacf);		/* 64-bit */
-		lputl((1<<24)|7);		/* cputype - x86/ABI64 */
-		lputl(3);			/* subtype - x86 */
-		lputl(2);			/* file type - mach executable */
-		nl = 4;
-		if (!debug['s'])
-			nl += 3;
-		if (!debug['d'])	// -d = turn off "dynamic loader"
-			nl += 3;
-		lputl(nl);			/* number of loads */
-		lputl(machheadr()-32);		/* size of loads */
-		lputl(1);			/* flags - no undefines */
-		lputl(0);			/* reserved */
-
-		machseg("__PAGEZERO",
-			0,va,			/* vaddr vsize */
-			0,0,			/* fileoffset filesize */
-			0,0,			/* protects */
-			0,0);			/* sections flags */
+		va = HEADR;
+		mh = getMachoHdr();
+		mh->cpu = MACHO_CPU_AMD64;
+		mh->subcpu = MACHO_SUBCPU_X86;
 
-		v = rnd(HEADR+textsize, INITRND);
-		machseg("__TEXT",
-			va,			/* vaddr */
-			v,			/* vsize */
-			0,v,			/* fileoffset filesize */
-			7,5,			/* protects */
-			1,0);			/* sections flags */
-		machsect("__text", "__TEXT",
-			va+HEADR,v-HEADR,	/* addr size */
-			HEADR,0,0,0,		/* offset align reloc nreloc */
-			0|0x400);		/* flag - some instructions */
+		/* segment for zero page */
+		ms = newMachoSeg("__PAGEZERO", 0);
+		ms->vsize = va;
 
+		/* text */
+		v = rnd(HEADR+textsize, INITRND);
+		ms = newMachoSeg("__TEXT", 1);
+		ms->vaddr = va;
+		ms->vsize = v;
+		ms->filesize = v;
+		ms->prot1 = 7;
+		ms->prot2 = 5;
+
+		msect = newMachoSect(ms, "__text");
+		msect->addr = va+HEADR;
+		msect->size = v - HEADR;
+		msect->off = HEADR;
+		msect->flag = 0x400;	/* flag - some instructions */
+
+		/* data */
 		w = datsize+bsssize;
-		machseg("__DATA",
-			va+v,			/* vaddr */
-			w,			/* vsize */
-			v,datsize,		/* fileoffset filesize */
-			7,3,			/* protects */
-			2,0);			/* sections flags */
-		machsect("__data", "__DATA",
-			va+v,datsize,		/* addr size */
-			v,0,0,0,		/* offset align reloc nreloc */
-			0);			/* flag */
-		machsect("__bss", "__DATA",
-			va+v+datsize,bsssize,	/* addr size */
-			0,0,0,0,		/* offset align reloc nreloc */
-			1);			/* flag - zero fill */
-
-		machdylink();
-		machstack(entryvalue());
+		ms = newMachoSeg("__DATA", 2);
+		ms->vaddr = va+v;
+		ms->vsize = w;
+		ms->fileoffset = v;
+		ms->filesize = datsize;
+		ms->prot1 = 7;
+		ms->prot2 = 3;
+
+		msect = newMachoSect(ms, "__data");
+		msect->addr = va+v;
+		msect->size = datsize;
+		msect->off = v;
+
+		msect = newMachoSect(ms, "__bss");
+		msect->addr = va+v+datsize;
+		msect->size = bsssize;
+		msect->flag = 1;	/* flag - zero fill */
+
+		ml = newMachoLoad(5, 42+2);	/* unix thread */
+		ml->data[0] = 4;	/* thread type */
+		ml->data[1] = 42;	/* word count */
+		ml->data[2+32] = entryvalue();	/* start pc */
+		ml->data[2+32+1] = entryvalue()>>32;
 
-		if (!debug['s']) {
-			machseg("__SYMDAT",
-				symdatva,		/* vaddr */
-				8+symsize+lcsize,		/* vsize */
-				symo, 8+symsize+lcsize,	/* fileoffset filesize */
-				7, 5,			/* protects */
-				0, 0);			/* sections flags */
-
-			machsymseg(symo+8,symsize);	/* fileoffset,filesize */
-			machsymseg(symo+8+symsize,lcsize);	/* fileoffset,filesize */
+		if(!debug['d']) {
+			ml = newMachoLoad(2, 4);	/* LC_SYMTAB */
+			USED(ml);
+
+			ml = newMachoLoad(11, 18);	/* LC_DYSYMTAB */
+			USED(ml);
+
+			ml = newMachoLoad(14, 6);	/* LC_LOAD_DYLINKER */
+			ml->data[0] = 12;	/* offset to string */
+			strcpy((char*)&ml->data[1], "/usr/lib/dyld");
 		}
+
+		if(!debug['s']) {
+			ms = newMachoSeg("__SYMDAT", 1);
+			ms->vaddr = symdatva;
+			ms->vsize = 8+symsize+lcsize;
+			ms->fileoffset = symo;
+			ms->filesize = 8+symsize+lcsize;
+			ms->prot1 = 7;
+			ms->prot2 = 5;
+
+			md = newMachoDebug();
+			md->fileoffset = symo+8;
+			md->filesize = symsize;
+
+			md = newMachoDebug();
+			md->fileoffset = symo+8+symsize;
+			md->filesize = lcsize;
+		}
+
+		a = machowrite();
+		if(a > MACHORESERVE)
+			diag("MACHORESERVE too small: %d > %d", a, MACHORESERVE);
 		break;
+
 	case 7:
 		/* elf amd-64 */
 
@@ -889,11 +915,8 @@ asmb(void)
 		a += elfwritehdr();
 		a += elfwritephdrs();
 		a += elfwriteshdrs();
-		if (a > ELFRESERVE) {
+		if (a > ELFRESERVE)
 			diag("ELFRESERVE too small: %d > %d", a, ELFRESERVE);
-		}
-		cflush();
-
 		break;
 	}
 	cflush();
@@ -1079,122 +1102,3 @@ rnd(vlong v, vlong r)
 	return v;
 }
 
-void
-machseg(char *name, vlong vaddr, vlong vsize, vlong foff, vlong fsize,
-	uint32 prot1, uint32 prot2, uint32 nsect, uint32 flag)
-{
-	lputl(25);	/* segment 64 */
-	lputl(72 + 80*nsect);
-	strnput(name, 16);
-	vputl(vaddr);
-	vputl(vsize);
-	vputl(foff);
-	vputl(fsize);
-	lputl(prot1);
-	lputl(prot2);
-	lputl(nsect);
-	lputl(flag);
-}
-
-void
-machsymseg(uint32 foffset, uint32 fsize)
-{
-	lputl(3);	/* obsolete gdb debug info */
-	lputl(16);	/* size of symseg command */
-	lputl(foffset);
-	lputl(fsize);
-}
-
-void
-machsect(char *name, char *seg, vlong addr, vlong size, uint32 off,
-	uint32 align, uint32 reloc, uint32 nreloc, uint32 flag)
-{
-	strnput(name, 16);
-	strnput(seg, 16);
-	vputl(addr);
-	vputl(size);
-	lputl(off);
-	lputl(align);
-	lputl(reloc);
-	lputl(nreloc);
-	lputl(flag);
-	lputl(0);	/* reserved */
-	lputl(0);	/* reserved */
-	lputl(0);	/* reserved */
-}
-
-// Emit a section requesting the dynamic loader
-// but giving it no work to do (an empty dynamic symbol table).
-// This is enough to make the Apple tracing programs (like dtrace)
-// accept the binary, so that one can run dtruss on a 6.out.
-// The dynamic linker loads at 0x8fe00000, so if we want to
-// be able to build >2GB binaries, we're going to need to move
-// the text segment to 4G like Apple does.
-void
-machdylink(void)
-{
-	int i;
-
-	if(debug['d'])
-		return;
-
-	lputl(2);	/* LC_SYMTAB */
-	lputl(24);	/* byte count - 6 words*/
-	for(i=0; i<4; i++)
-		lputl(0);
-
-	lputl(11);	/* LC_DYSYMTAB */
-	lputl(80);	/* byte count - 20 words */
-	for(i=0; i<18; i++)
-		lputl(0);
-
-	lputl(14);	/* LC_LOAD_DYLINKER */
-	lputl(32);	/* byte count */
-	lputl(12);	/* offset to string */
-	strnput("/usr/lib/dyld", 32-12);
-}
-
-void
-machstack(vlong e)
-{
-	int i;
-
-	lputl(5);			/* unix thread */
-	lputl((42+4)*4);		/* total byte count */
-
-	lputl(4);			/* thread type */
-	lputl(42);			/* word count */
-
-	for(i=0; i<32; i++)
-		lputl(0);
-	vputl(e);
-	for(i=0; i<8; i++)
-		lputl(0);
-}
-
-uint32
-machheadr(void)
-{
-	uint32 a;
-
-	a = 8;		/* a.out header */
-	a += 18;	/* page zero seg */
-	a += 18;	/* text seg */
-	a += 20;	/* text sect */
-	a += 18;	/* data seg */
-	a += 20;	/* data sect */
-	a += 20;	/* bss sect */
-	a += 46;	/* stack sect */
-	if (!debug['d']) {
-		a += 6;	/* symtab */
-		a += 20;	/* dysymtab */
-		a += 8;	/* load dylinker */
-	}
-	if (!debug['s']) {
-		a += 18;	/* symdat seg */
-		a += 4;	/* symtab seg */
-		a += 4;	/* lctab seg */
-	}
-
-	return a*4;
-}
diff --git a/src/cmd/6l/macho.c b/src/cmd/6l/macho.c
new file mode 100644
index 000000000..bafb0258c
--- /dev/null
+++ b/src/cmd/6l/macho.c
@@ -0,0 +1,6 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "l.h"
+#include "../ld/macho.c"
diff --git a/src/cmd/6l/obj.c b/src/cmd/6l/obj.c
index 4c115b180..ba2dec3b2 100644
--- a/src/cmd/6l/obj.c
+++ b/src/cmd/6l/obj.c
@@ -31,6 +31,7 @@
 #define	EXTERN
 #include	"l.h"
 #include	"../ld/elf.h"
+#include	"../ld/macho.h"
 #include	<ar.h>
 
 char	*noname		= "<none>";
@@ -188,7 +189,8 @@ main(int argc, char *argv[])
 			INITRND = 4096;
 		break;
 	case 6:	/* apple MACH */
-		HEADR = machheadr();
+		machoinit();
+		HEADR = MACHORESERVE;
 		if(INITTEXT == -1)
 			INITTEXT = 4096+HEADR;
 		if(INITDAT == -1)
diff --git a/src/cmd/8l/Makefile b/src/cmd/8l/Makefile
index 21b589b13..e0ba629e6 100644
--- a/src/cmd/8l/Makefile
+++ b/src/cmd/8l/Makefile
@@ -13,6 +13,7 @@ OFILES=\
 	elf.$O\
 	enam.$O\
 	list.$O\
+	macho.$O\
 	obj.$O\
 	optab.$O\
 	pass.$O\
@@ -23,6 +24,7 @@ HFILES=\
 	l.h\
 	../8l/8.out.h\
 	../ld/elf.h\
+	../ld/macho.h\
 
 
 $(TARG): $(OFILES)
@@ -41,3 +43,4 @@ install: $(TARG)
 
 go.o: ../ld/go.c
 elf.o: ../ld/elf.c
+macho.o: ../ld/macho.c
diff --git a/src/cmd/8l/asm.c b/src/cmd/8l/asm.c
index 627bd25e8..449467a5c 100644
--- a/src/cmd/8l/asm.c
+++ b/src/cmd/8l/asm.c
@@ -30,26 +30,12 @@
 
 #include	"l.h"
 #include	"../ld/elf.h"
+#include	"../ld/macho.h"
 
 #define	Dbufslop	100
 
 char linuxdynld[] = "/lib/ld-linux.so.2";
-
 uint32 symdatva = 0x99<<24;
-uint32 stroffset;
-uint32 strtabsize;
-
-uint32 machheadr(void);
-uint32		elfheadr(void);
-void		elfphdr(int type, int flags, uint32 foff, uint32 vaddr, uint32 paddr, uint32 filesize, uint32 memsize, uint32 align);
-void		elfshdr(char *name, uint32 type, uint32 flags, uint32 addr, uint32 off, uint32 size, uint32 link, uint32 info, uint32 align, uint32 entsize);
-int		elfstrtable(void);
-void		machdylink(void);
-uint32		machheadr(void);
-void		machsect(char *name, char *seg, vlong addr, vlong size, uint32 off, uint32 align, uint32 reloc, uint32 nreloc, uint32 flag);
-void		machseg(char *name, uint32 vaddr, uint32 vsize, uint32 foff, uint32 fsize, uint32 prot1, uint32 prot2, uint32 nsect, uint32 flag);
-void		machstack(vlong e);
-void		machsymseg(uint32 foffset, uint32 fsize);
 
 int32
 entryvalue(void)
@@ -428,13 +414,18 @@ asmb(void)
 {
 	Prog *p;
 	int32 v, magic;
-	int a, nl, dynsym;
+	int a, dynsym;
 	uint32 va, fo, w, symo, startva;
 	uchar *op1;
 	ulong expectpc;
-	Elf64_Ehdr *eh;
-	Elf64_Phdr *ph, *pph;
-	Elf64_Shdr *sh;
+	ElfEhdr *eh;
+	ElfPhdr *ph, *pph;
+	ElfShdr *sh;
+	MachoHdr *mh;
+	MachoSect *msect;
+	MachoSeg *ms;
+	MachoDebug *md;
+	MachoLoad *ml;
 
 	if(debug['v'])
 		Bprint(&bso, "%5.2f asmb\n", cputime());
@@ -585,7 +576,7 @@ asmb(void)
 			break;
 		case 7:
 		case 8:
-			symo = rnd(HEADR+textsize, INITRND)+datsize+strtabsize;
+			symo = rnd(HEADR+textsize, INITRND)+datsize;
 			symo = rnd(symo, INITRND);
 			break;
 		}
@@ -750,69 +741,88 @@ asmb(void)
 
 	case 6:
 		/* apple MACH */
-		va = 4096;
-
-		lputl(0xfeedface);		/* 32-bit */
-		lputl(7);		/* cputype - x86 */
-		lputl(3);			/* subtype - x86 */
-		lputl(2);			/* file type - mach executable */
-		nl = 4;
-		if (!debug['s'])
-			nl += 3;
-		if (!debug['d'])	// -d = turn off "dynamic loader"
-			nl += 3;
-		lputl(nl);			/* number of loads */
-		lputl(machheadr()-28);		/* size of loads */
-		lputl(1);			/* flags - no undefines */
-
-		machseg("__PAGEZERO",
-			0,va,			/* vaddr vsize */
-			0,0,			/* fileoffset filesize */
-			0,0,			/* protects */
-			0,0);			/* sections flags */
+		va = HEADR;
+		mh = getMachoHdr();
+		mh->cpu = MACHO_CPU_386;
+		mh->subcpu = MACHO_SUBCPU_X86;
 
-		v = rnd(HEADR+textsize, INITRND);
-		machseg("__TEXT",
-			va,			/* vaddr */
-			v,			/* vsize */
-			0,v,			/* fileoffset filesize */
-			7,5,			/* protects */
-			1,0);			/* sections flags */
-		machsect("__text", "__TEXT",
-			va+HEADR,v-HEADR,	/* addr size */
-			HEADR,0,0,0,		/* offset align reloc nreloc */
-			0|0x400);		/* flag - some instructions */
+		/* segment for zero page */
+		ms = newMachoSeg("__PAGEZERO", 0);
+		ms->vsize = va;
 
+		/* text */
+		v = rnd(HEADR+textsize, INITRND);
+		ms = newMachoSeg("__TEXT", 1);
+		ms->vaddr = va;
+		ms->vsize = v;
+		ms->filesize = v;
+		ms->prot1 = 7;
+		ms->prot2 = 5;
+
+		msect = newMachoSect(ms, "__text");
+		msect->addr = va+HEADR;
+		msect->size = v - HEADR;
+		msect->off = HEADR;
+		msect->flag = 0x400;	/* flag - some instructions */
+
+		/* data */
 		w = datsize+bsssize;
-		machseg("__DATA",
-			va+v,			/* vaddr */
-			w,			/* vsize */
-			v,datsize,		/* fileoffset filesize */
-			7,3,			/* protects */
-			2,0);			/* sections flags */
-		machsect("__data", "__DATA",
-			va+v,datsize,		/* addr size */
-			v,0,0,0,		/* offset align reloc nreloc */
-			0);			/* flag */
-		machsect("__bss", "__DATA",
-			va+v+datsize,bsssize,	/* addr size */
-			0,0,0,0,		/* offset align reloc nreloc */
-			1);			/* flag - zero fill */
-
-		machdylink();
-		machstack(entryvalue());
+		ms = newMachoSeg("__DATA", 2);
+		ms->vaddr = va+v;
+		ms->vsize = w;
+		ms->fileoffset = v;
+		ms->filesize = datsize;
+		ms->prot1 = 7;
+		ms->prot2 = 3;
+
+		msect = newMachoSect(ms, "__data");
+		msect->addr = va+v;
+		msect->size = datsize;
+		msect->off = v;
+
+		msect = newMachoSect(ms, "__bss");
+		msect->addr = va+v+datsize;
+		msect->size = bsssize;
+		msect->flag = 1;	/* flag - zero fill */
+
+		ml = newMachoLoad(5, 16+2);	/* unix thread */
+		ml->data[0] = 1;	/* thread type */
+		ml->data[1] = 16;	/* word count */
+		ml->data[2+10] = entryvalue();	/* start pc */
 
-		if (!debug['s']) {
-			machseg("__SYMDAT",
-				symdatva,		/* vaddr */
-				8+symsize+lcsize,		/* vsize */
-				symo, 8+symsize+lcsize,	/* fileoffset filesize */
-				7, 5,			/* protects */
-				0, 0);			/* sections flags */
-
-			machsymseg(symo+8,symsize);	/* fileoffset,filesize */
-			machsymseg(symo+8+symsize,lcsize);	/* fileoffset,filesize */
+		if(!debug['d']) {
+			ml = newMachoLoad(2, 4);	/* LC_SYMTAB */
+			USED(ml);
+
+			ml = newMachoLoad(11, 18);	/* LC_DYSYMTAB */
+			USED(ml);
+
+			ml = newMachoLoad(14, 6);	/* LC_LOAD_DYLINKER */
+			ml->data[0] = 12;	/* offset to string */
+			strcpy((char*)&ml->data[1], "/usr/lib/dyld");
+		}
+
+		if(!debug['s']) {
+			ms = newMachoSeg("__SYMDAT", 1);
+			ms->vaddr = symdatva;
+			ms->vsize = 8+symsize+lcsize;
+			ms->fileoffset = symo;
+			ms->filesize = 8+symsize+lcsize;
+			ms->prot1 = 7;
+			ms->prot2 = 5;
+
+			md = newMachoDebug();
+			md->fileoffset = symo+8;
+			md->filesize = symsize;
+
+			md = newMachoDebug();
+			md->fileoffset = symo+8+symsize;
+			md->filesize = lcsize;
 		}
+
+		a = machowrite();
+		if(a > MACHORESERVE)
+			diag("MACHORESERVE too small: %d > %d", a, MACHORESERVE);
 		break;
 
 	case 7:
@@ -1242,129 +1252,3 @@ rnd(int32 v, int32 r)
 	v -= c;
 	return v;
 }
-
-void
-machseg(char *name, uint32 vaddr, uint32 vsize, uint32 foff, uint32 fsize,
-	uint32 prot1, uint32 prot2, uint32 nsect, uint32 flag)
-{
-	lputl(1);	/* segment 32 */
-	lputl(56 + 68*nsect);
-	strnput(name, 16);
-	lputl(vaddr);
-	lputl(vsize);
-	lputl(foff);
-	lputl(fsize);
-	lputl(prot1);
-	lputl(prot2);
-	lputl(nsect);
-	lputl(flag);
-}
-
-void
-machsymseg(uint32 foffset, uint32 fsize)
-{
-	lputl(3);	/* obsolete gdb debug info */
-	lputl(16);	/* size of symseg command */
-	lputl(foffset);
-	lputl(fsize);
-}
-
-void
-machsect(char *name, char *seg, vlong addr, vlong size, uint32 off,
-	uint32 align, uint32 reloc, uint32 nreloc, uint32 flag)
-{
-	strnput(name, 16);
-	strnput(seg, 16);
-	lputl(addr);
-	lputl(size);
-	lputl(off);
-	lputl(align);
-	lputl(reloc);
-	lputl(nreloc);
-	lputl(flag);
-	lputl(0);	/* reserved */
-	lputl(0);	/* reserved */
-}
-
-// Emit a section requesting the dynamic loader
-// but giving it no work to do (an empty dynamic symbol table).
-// This is enough to make the Apple tracing programs (like dtrace)
-// accept the binary, so that one can run dtruss on an 8.out.
-void
-machdylink(void)
-{
-	int i;
-
-	if(debug['d'])
-		return;
-
-	lputl(2);	/* LC_SYMTAB */
-	lputl(24);	/* byte count - 6 words*/
-	for(i=0; i<4; i++)
-		lputl(0);
-
-	lputl(11);	/* LC_DYSYMTAB */
-	lputl(80);	/* byte count - 20 words */
-	for(i=0; i<18; i++)
-		lputl(0);
-
-	lputl(14);	/* LC_LOAD_DYLINKER */
-	lputl(32);	/* byte count */
-	lputl(12);	/* offset to string */
-	strnput("/usr/lib/dyld", 32-12);
-}
-
-void
-machstack(vlong e)
-{
-	int i;
-
-	lputl(5);			/* unix thread */
-	lputl((16+4)*4);		/* total byte count */
-
-	lputl(1);			/* thread type - x86_THREAD_STATE32 */
-	lputl(16);			/* word count */
-
-	for(i=0; i<16; i++)	/* initial register set */
-		if(i == 10)
-			lputl(e);
-		else
-			lputl(0);
-}
-
-uint32
-machheadr(void)
-{
-	uint32 a;
-	enum {
-		Header = 28,
-		Seg = 56,
-		Sect = 68,
-		Symtab = 24,
-		Dysymtab = 80,
-		LoadDylinker = 32,
-		Stack = 80,
-		Symseg = 16,
-	};
-
-	a = Header;		/* a.out header */
-	a += Seg;	/* page zero seg */
-	a += Seg;	/* text seg */
-	a += Sect;	/* text sect */
-	a += Seg;	/* data seg */
-	a += Sect;	/* data sect */
-	a += Sect;	/* bss sect */
-	if (!debug['d']) {
-		a += Symtab;	/* symtab */
-		a += Dysymtab;	/* dysymtab */
-		a += LoadDylinker;	/* load dylinker */
-	}
-	a += Stack;	/* stack sect */
-	if (!debug['s']) {
-		a += Seg;	/* symdat seg */
-		a += Symseg;	/* symtab seg */
-		a += Symseg;	/* lctab seg */
-	}
-
-	return a;
-}
diff --git a/src/cmd/8l/l.h b/src/cmd/8l/l.h
index ce28b1336..cc5901fcb 100644
--- a/src/cmd/8l/l.h
+++ b/src/cmd/8l/l.h
@@ -371,6 +371,7 @@ Sym*	lookup(char*, int);
 void	lput(int32);
 void	lputl(int32);
 void	vputl(uvlong);
+void	strnput(char*, int);
 void	main(int, char*[]);
 void	mkfwd(void);
 void*	mal(uint32);
diff --git a/src/cmd/8l/macho.c b/src/cmd/8l/macho.c
new file mode 100644
index 000000000..a4a4e6954
--- /dev/null
+++ b/src/cmd/8l/macho.c
@@ -0,0 +1,6 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "l.h"
+#include "../ld/macho.c"
diff --git a/src/cmd/8l/obj.c b/src/cmd/8l/obj.c
index 96099e77f..4b6532568 100644
--- a/src/cmd/8l/obj.c
+++ b/src/cmd/8l/obj.c
@@ -31,6 +31,7 @@
 #define	EXTERN
 #include	"l.h"
 #include	"../ld/elf.h"
+#include	"../ld/macho.h"
 #include	<ar.h>
 
 #ifndef	DEFAULT
@@ -212,7 +213,8 @@ main(int argc, char *argv[])
 			Bprint(&bso, "HEADR = 0x%ld\n", HEADR);
 		break;
 	case 6:	/* apple MACH */
-		HEADR = machheadr();
+		machoinit();
+		HEADR = MACHORESERVE;
 		if(INITTEXT == -1)
 			INITTEXT = 4096+HEADR;
 		if(INITDAT == -1)
diff --git a/src/cmd/ld/elf.h b/src/cmd/ld/elf.h
index 0edadc43d..cb4857248 100644
--- a/src/cmd/ld/elf.h
+++ b/src/cmd/ld/elf.h
@@ -963,7 +963,7 @@ extern	int	numelfphdr;
 extern	int	numelfshdr;
 
 /*
- * Total amount of ELF space to reserve at the start of the file
+ * Total amount of space to reserve at the start of the file
  * for Header, PHeaders, and SHeaders.
  * May waste some.
  */
diff --git a/src/cmd/ld/macho.c b/src/cmd/ld/macho.c
new file mode 100644
index 000000000..159aceb9e
--- /dev/null
+++ b/src/cmd/ld/macho.c
@@ -0,0 +1,207 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Mach-O file writing
+// http://developer.apple.com/mac/library/DOCUMENTATION/DeveloperTools/Conceptual/MachORuntime/Reference/reference.html
+
+#include "../ld/macho.h"
+
+static	int	macho64;
+static	MachoHdr	hdr;
+static	MachoLoad	load[16];
+static	MachoSeg	seg[16];
+static	MachoDebug	xdebug[16];
+static	int	nload, nseg, ndebug, nsect;
+
+void
+machoinit(void)
+{
+	switch(thechar) {
+	// 64-bit architectures
+	case '6':
+		macho64 = 1;
+		break;
+
+	// 32-bit architectures
+	default:
+		break;
+	}
+}
+
+MachoHdr*
+getMachoHdr(void)
+{
+	return &hdr;
+}
+
+MachoLoad*
+newMachoLoad(uint32 type, uint32 ndata)
+{
+	MachoLoad *l;
+
+	if(nload >= nelem(load)) {
+		diag("too many loads");
+		errorexit();
+	}
+	l = &load[nload++];
+	l->type = type;
+	l->ndata = ndata;
+	l->data = mal(ndata*4);
+	return l;
+}
+
+MachoSeg*
+newMachoSeg(char *name, int msect)
+{
+	MachoSeg *s;
+
+	if(nseg >= nelem(seg)) {
+		diag("too many segs");
+		errorexit();
+	}
+	s = &seg[nseg++];
+	s->name = name;
+	s->msect = msect;
+	s->sect = mal(msect*sizeof s->sect[0]);
+	return s;
+}
+
+MachoSect*
+newMachoSect(MachoSeg *seg, char *name)
+{
+	MachoSect *s;
+
+	if(seg->nsect >= seg->msect) {
+		diag("too many sects in segment %s", seg->name);
+		errorexit();
+	}
+	s = &seg->sect[seg->nsect++];
+	s->name = name;
+	nsect++;
+	return s;
+}
+
+MachoDebug*
+newMachoDebug(void)
+{
+	if(ndebug >= nelem(xdebug)) {
+		diag("too many debugs");
+		errorexit();
+	}
+	return &xdebug[ndebug++];
+}
+
+int
+machowrite(void)
+{
+	vlong o1;
+	int loadsize;
+	int i, j;
+	MachoSeg *s;
+	MachoSect *t;
+	MachoDebug *d;
+	MachoLoad *l;
+
+	o1 = Boffset(&bso);
+
+	loadsize = 4*4*ndebug;
+	for(i=0; i<nload; i++)
+		loadsize += 4*(load[i].ndata+2);
+	if(macho64) {
+		loadsize += 18*4*nseg;
+		loadsize += 20*4*nsect;
+	} else {
+		loadsize += 14*4*nseg;
+		loadsize += 17*4*nsect;
+	}
+
+	if(macho64)
+		LPUT(0xfeedfacf);
+	else
+		LPUT(0xfeedface);
+	LPUT(hdr.cpu);
+	LPUT(hdr.subcpu);
+	LPUT(2);	/* file type - mach executable */
+	LPUT(nload+nseg+ndebug);
+	LPUT(loadsize);
+	LPUT(1);	/* flags - no undefines */
+	if(macho64)
+		LPUT(0);	/* reserved */
+
+	for(i=0; i<nseg; i++) {
+		s = &seg[i];
+		if(macho64) {
+			LPUT(25);	/* segment 64 */
+			LPUT(72+80*s->nsect);
+			strnput(s->name, 16);
+			VPUT(s->vaddr);
+			VPUT(s->vsize);
+			VPUT(s->fileoffset);
+			VPUT(s->filesize);
+			LPUT(s->prot1);
+			LPUT(s->prot2);
+			LPUT(s->nsect);
+			LPUT(s->flag);
+		} else {
+			LPUT(1);	/* segment 32 */
+			LPUT(56+68*s->nsect);
+			strnput(s->name, 16);
+			LPUT(s->vaddr);
+			LPUT(s->vsize);
+			LPUT(s->fileoffset);
+			LPUT(s->filesize);
+			LPUT(s->prot1);
+			LPUT(s->prot2);
+			LPUT(s->nsect);
+			LPUT(s->flag);
+		}
+		for(j=0; j<s->nsect; j++) {
+			t = &s->sect[j];
+			if(macho64) {
+				strnput(t->name, 16);
+				strnput(s->name, 16);
+				VPUT(t->addr);
+				VPUT(t->size);
+				LPUT(t->off);
+				LPUT(t->align);
+				LPUT(t->reloc);
+				LPUT(t->nreloc);
+				LPUT(t->flag);
+				LPUT(0);	/* reserved */
+				LPUT(0);	/* reserved */
+				LPUT(0);	/* reserved */
+			} else {
+				strnput(t->name, 16);
+				strnput(s->name, 16);
+				LPUT(t->addr);
+				LPUT(t->size);
+				LPUT(t->off);
+				LPUT(t->align);
+				LPUT(t->reloc);
+				LPUT(t->nreloc);
+				LPUT(t->flag);
+				LPUT(0);	/* reserved */
+				LPUT(0);	/* reserved */
+			}
+		}
+	}
+
+	for(i=0; i<nload; i++) {
+		l = &load[i];
+		LPUT(l->type);
+		LPUT(4*(l->ndata+2));
+		for(j=0; j<l->ndata; j++)
+			LPUT(l->data[j]);
+	}
+
+	for(i=0; i<ndebug; i++) {
+		d = &xdebug[i];
+		LPUT(3);	/* obsolete gdb debug info */
+		LPUT(16);	/* size of symseg command */
+		LPUT(d->fileoffset);
+		LPUT(d->filesize);
+	}
+
+	return Boffset(&bso) - o1;
+}
diff --git a/src/cmd/ld/macho.h b/src/cmd/ld/macho.h
new file mode 100644
index 000000000..747adac2d
--- /dev/null
+++ b/src/cmd/ld/macho.h
@@ -0,0 +1,70 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+typedef struct MachoHdr MachoHdr;
+struct MachoHdr {
+	uint32	cpu;
+	uint32	subcpu;
+};
+
+typedef struct MachoSect MachoSect;
+struct MachoSect {
+	char*	name;
+	uint64	addr;
+	uint64	size;
+	uint32	off;
+	uint32	align;
+	uint32	reloc;
+	uint32	nreloc;
+	uint32	flag;
+};
+
+typedef struct MachoSeg MachoSeg;
+struct MachoSeg {
+	char*	name;
+	uint64	vsize;
+	uint64	vaddr;
+	uint64	fileoffset;
+	uint64	filesize;
+	uint32	prot1;
+	uint32	prot2;
+	uint32	nsect;
+	uint32	msect;
+	MachoSect	*sect;
+	uint32	flag;
+};
+
+typedef struct MachoLoad MachoLoad;
+struct MachoLoad {
+	uint32	type;
+	uint32	ndata;
+	uint32	*data;
+};
+
+typedef struct MachoDebug MachoDebug;
+struct MachoDebug {
+	uint32	fileoffset;
+	uint32	filesize;
+};
+
+MachoHdr*	getMachoHdr();
+MachoSeg*	newMachoSeg(char*, int);
+MachoSect*	newMachoSect(MachoSeg*, char*);
+MachoLoad*	newMachoLoad(uint32, uint32);
+MachoDebug*	newMachoDebug(void);
+int	machowrite(void);
+void	machoinit(void);
+
+/*
+ * Total amount of space to reserve at the start of the file
+ * for Header, PHeaders, and SHeaders.
+ * May waste some.
+ */
+#define	MACHORESERVE	4096
+
+enum {
+	MACHO_CPU_AMD64 = (1<<24)|7,
+	MACHO_CPU_386 = 7,
+	MACHO_SUBCPU_X86 = 3,
+};