Imported Upstream version 2011.01.12upstream/2011.01.12

16 files changed, 6916 insertions, 637 deletions

diff --git a/src/cmd/ld/data.c b/src/cmd/ld/data.c
new file mode 100644
index 000000000..210f10ab5
--- /dev/null
+++ b/src/cmd/ld/data.c
@@ -0,0 +1,914 @@
+// Inferno utils/8l/asm.c
+// http://code.google.com/p/inferno-os/source/browse/utils/8l/asm.c
+//
+//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
+//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+//	Portions Copyright © 1997-1999 Vita Nuova Limited
+//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
+//	Portions Copyright © 2004,2006 Bruce Ellis
+//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
+//	Portions Copyright © 2009 The Go Authors.  All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Data layout and relocation.
+
+#include	"l.h"
+#include	"../ld/lib.h"
+#include	"../ld/elf.h"
+#include	"../ld/pe.h"
+
+void	dynreloc(void);
+
+/*
+ * divide-and-conquer list-link
+ * sort of Sym* structures.
+ * Used for the data block.
+ */
+int
+datcmp(Sym *s1, Sym *s2)
+{
+	if(s1->type != s2->type)
+		return (int)s1->type - (int)s2->type;
+	if(s1->size != s2->size) {
+		if(s1->size < s2->size)
+			return -1;
+		return +1;
+	}
+	return strcmp(s1->name, s2->name);
+}
+
+Sym*
+datsort(Sym *l)
+{
+	Sym *l1, *l2, *le;
+
+	if(l == 0 || l->next == 0)
+		return l;
+
+	l1 = l;
+	l2 = l;
+	for(;;) {
+		l2 = l2->next;
+		if(l2 == 0)
+			break;
+		l2 = l2->next;
+		if(l2 == 0)
+			break;
+		l1 = l1->next;
+	}
+
+	l2 = l1->next;
+	l1->next = 0;
+	l1 = datsort(l);
+	l2 = datsort(l2);
+
+	/* set up lead element */
+	if(datcmp(l1, l2) < 0) {
+		l = l1;
+		l1 = l1->next;
+	} else {
+		l = l2;
+		l2 = l2->next;
+	}
+	le = l;
+
+	for(;;) {
+		if(l1 == 0) {
+			while(l2) {
+				le->next = l2;
+				le = l2;
+				l2 = l2->next;
+			}
+			le->next = 0;
+			break;
+		}
+		if(l2 == 0) {
+			while(l1) {
+				le->next = l1;
+				le = l1;
+				l1 = l1->next;
+			}
+			break;
+		}
+		if(datcmp(l1, l2) < 0) {
+			le->next = l1;
+			le = l1;
+			l1 = l1->next;
+		} else {
+			le->next = l2;
+			le = l2;
+			l2 = l2->next;
+		}
+	}
+	le->next = 0;
+	return l;
+}
+
+Reloc*
+addrel(Sym *s)
+{
+	if(s->nr >= s->maxr) {
+		if(s->maxr == 0)
+			s->maxr = 4;
+		else
+			s->maxr <<= 1;
+		s->r = realloc(s->r, s->maxr*sizeof s->r[0]);
+		if(s->r == 0) {
+			diag("out of memory");
+			errorexit();
+		}
+		memset(s->r+s->nr, 0, (s->maxr-s->nr)*sizeof s->r[0]);
+	}
+	return &s->r[s->nr++];
+}
+
+void
+relocsym(Sym *s)
+{
+	Reloc *r;
+	Prog p;
+	int32 i, off, siz, fl;
+	vlong o;
+	uchar *cast;
+	
+	cursym = s;
+	memset(&p, 0, sizeof p);
+	for(r=s->r; r<s->r+s->nr; r++) {
+		off = r->off;
+		siz = r->siz;
+		if(off < 0 || off+(siz&~Rbig) > s->np) {
+			diag("%s: invalid relocation %d+%d not in [%d,%d)", s->name, off, siz&~Rbig, 0, s->np);
+			continue;
+		}
+		if(r->sym != S && (r->sym->type == 0 || r->sym->type == SXREF)) {
+			diag("%s: not defined", r->sym->name);
+			continue;
+		}
+		if(r->type >= 256)
+			continue;
+
+		if(r->sym != S && r->sym->type == SDYNIMPORT)
+			diag("unhandled relocation for %s (type %d rtype %d)", r->sym->name, r->sym->type, r->type);
+
+		if(r->sym != S && !r->sym->reachable)
+			diag("unreachable sym in relocation: %s %s", s->name, r->sym->name);
+
+		switch(r->type) {
+		default:
+			o = 0;
+			if(archreloc(r, s, &o) < 0)
+				diag("unknown reloc %d", r->type);
+			break;
+		case D_ADDR:
+			o = symaddr(r->sym) + r->add;
+			break;
+		case D_PCREL:
+			o = symaddr(r->sym) + r->add - (s->value + r->off + r->siz);
+			break;
+		case D_SIZE:
+			o = r->sym->size + r->add;
+			break;
+		}
+//print("relocate %s %p %s => %p %p %p %p [%p]\n", s->name, s->value+off, r->sym ? r->sym->name : "<nil>", (void*)symaddr(r->sym), (void*)s->value, (void*)r->off, (void*)r->siz, (void*)o);
+		switch(siz) {
+		default:
+			cursym = s;
+			diag("bad reloc size %#ux for %s", siz, r->sym->name);
+		case 4 + Rbig:
+			fl = o;
+			s->p[off] = fl>>24;
+			s->p[off+1] = fl>>16;
+			s->p[off+2] = fl>>8;
+			s->p[off+3] = fl;
+			break;
+		case 4 + Rlittle:
+			fl = o;
+			s->p[off] = fl;
+			s->p[off+1] = fl>>8;
+			s->p[off+2] = fl>>16;
+			s->p[off+3] = fl>>24;
+			break;
+		case 4:
+			fl = o;
+			cast = (uchar*)&fl;
+			for(i=0; i<4; i++)
+				s->p[off+i] = cast[inuxi4[i]];
+			break;
+		case 8:
+			cast = (uchar*)&o;
+			for(i=0; i<8; i++)
+				s->p[off+i] = cast[inuxi8[i]];
+			break;
+		}		
+	}
+}
+
+void
+reloc(void)
+{
+	Sym *s;
+	
+	if(debug['v'])
+		Bprint(&bso, "%5.2f reloc\n", cputime());
+	Bflush(&bso);
+
+	for(s=textp; s!=S; s=s->next)
+		relocsym(s);
+	for(s=datap; s!=S; s=s->next)
+		relocsym(s);
+}
+
+void
+dynrelocsym(Sym *s)
+{
+	Reloc *r;
+
+	for(r=s->r; r<s->r+s->nr; r++)
+		if(r->sym->type == SDYNIMPORT || r->type >= 256)
+			adddynrel(s, r);
+}
+
+void
+dynreloc(void)
+{
+	Sym *s;
+	
+	if(debug['v'])
+		Bprint(&bso, "%5.2f reloc\n", cputime());
+	Bflush(&bso);
+
+	for(s=textp; s!=S; s=s->next)
+		dynrelocsym(s);
+	for(s=datap; s!=S; s=s->next)
+		dynrelocsym(s);
+	if(iself)
+		elfdynhash();
+}
+
+void
+symgrow(Sym *s, int32 siz)
+{
+	if(s->np >= siz)
+		return;
+
+	if(s->maxp < siz) {
+		if(s->maxp == 0)
+			s->maxp = 8;
+		while(s->maxp < siz)
+			s->maxp <<= 1;
+		s->p = realloc(s->p, s->maxp);
+		if(s->p == nil) {
+			diag("out of memory");
+			errorexit();
+		}
+		memset(s->p+s->np, 0, s->maxp-s->np);
+	}
+	s->np = siz;
+}
+
+void
+savedata(Sym *s, Prog *p)
+{
+	int32 off, siz, i, fl;
+	uchar *cast;
+	vlong o;
+	Reloc *r;
+
+	off = p->from.offset;
+	siz = p->datasize;
+	symgrow(s, off+siz);
+	
+	switch(p->to.type) {
+	default:
+		diag("bad data: %P", p);
+		break;
+
+	case D_FCONST:
+		switch(siz) {
+		default:
+		case 4:
+			fl = ieeedtof(&p->to.ieee);
+			cast = (uchar*)&fl;
+			for(i=0; i<4; i++)
+				s->p[off+i] = cast[fnuxi4[i]];
+			break;
+		case 8:
+			cast = (uchar*)&p->to.ieee;
+			for(i=0; i<8; i++)
+				s->p[off+i] = cast[fnuxi8[i]];
+			break;
+		}
+		break;
+	
+	case D_SCONST:
+		for(i=0; i<siz; i++)
+			s->p[off+i] = p->to.scon[i];
+		break;
+	
+	case D_CONST:
+		if(p->to.sym)
+			goto Addr;
+		o = p->to.offset;
+		fl = o;
+		cast = (uchar*)&fl;
+		switch(siz) {
+		default:
+			diag("bad nuxi %d\n%P", siz, p);
+			break;
+		case 1:
+			s->p[off] = cast[inuxi1[0]];
+			break;
+		case 2:
+			for(i=0; i<2; i++)
+				s->p[off+i] = cast[inuxi2[i]];
+			break;
+		case 4:
+			for(i=0; i<4; i++)
+				s->p[off+i] = cast[inuxi4[i]];
+			break;
+		case 8:
+			cast = (uchar*)&o;
+			for(i=0; i<8; i++)
+				s->p[off+i] = cast[inuxi8[i]];
+			break;
+		}
+		break;
+
+	case D_ADDR:
+	case D_SIZE:
+	Addr:
+		r = addrel(s);
+		r->off = off;
+		r->siz = siz;
+		r->sym = p->to.sym;
+		r->type = p->to.type;
+		if(r->type != D_SIZE)
+			r->type = D_ADDR;
+		r->add = p->to.offset;
+		break;
+	}
+}
+
+static void
+blk(Sym *allsym, int32 addr, int32 size)
+{
+	Sym *sym;
+	int32 eaddr;
+	uchar *p, *ep;
+
+	for(sym = allsym; sym != nil; sym = sym->next)
+		if(!(sym->type&SSUB) && sym->value >= addr)
+			break;
+
+	eaddr = addr+size;
+	for(; sym != nil; sym = sym->next) {
+		if(sym->type&SSUB)
+			continue;
+		if(sym->value >= eaddr)
+			break;
+		if(sym->value < addr) {
+			diag("phase error: addr=%#llx but sym=%#llx type=%d", (vlong)addr, (vlong)sym->value, sym->type);
+			errorexit();
+		}
+		cursym = sym;
+		for(; addr < sym->value; addr++)
+			cput(0);
+		p = sym->p;
+		ep = p + sym->np;
+		while(p < ep)
+			cput(*p++);
+		addr += sym->np;
+		for(; addr < sym->value+sym->size; addr++)
+			cput(0);
+		if(addr != sym->value+sym->size) {
+			diag("phase error: addr=%#llx value+size=%#llx", (vlong)addr, (vlong)sym->value+sym->size);
+			errorexit();
+		}
+	}
+	
+	for(; addr < eaddr; addr++)
+		cput(0);
+	cflush();
+}
+			
+void
+codeblk(int32 addr, int32 size)
+{
+	Sym *sym;
+	int32 eaddr, n, epc;
+	Prog *p;
+	uchar *q;
+
+	if(debug['a'])
+		Bprint(&bso, "codeblk [%#x,%#x) at offset %#llx\n", addr, addr+size, seek(cout, 0, 1));
+
+	blk(textp, addr, size);
+
+	/* again for printing */
+	if(!debug['a'])
+		return;
+
+	for(sym = textp; sym != nil; sym = sym->next) {
+		if(!sym->reachable)
+			continue;
+		if(sym->value >= addr)
+			break;
+	}
+
+	eaddr = addr + size;
+	for(; sym != nil; sym = sym->next) {
+		if(!sym->reachable)
+			continue;
+		if(sym->value >= eaddr)
+			break;
+
+		if(addr < sym->value) {
+			Bprint(&bso, "%-20s %.8llux|", "_", (vlong)addr);
+			for(; addr < sym->value; addr++)
+				Bprint(&bso, " %.2ux", 0);
+			Bprint(&bso, "\n");
+		}
+		p = sym->text;
+		if(p == nil) {
+			Bprint(&bso, "%.6llux\t%-20s | foreign text\n", (vlong)addr, sym->name);
+			n = sym->size;
+			q = sym->p;
+			
+			while(n >= 16) {
+				Bprint(&bso, "%.6ux\t%-20.16I\n",  addr, q);
+				addr += 16;
+				q += 16;
+				n -= 16;
+			}
+			if(n > 0)
+				Bprint(&bso, "%.6ux\t%-20.*I\n", addr, n, q);
+			addr += n;
+			continue;
+		}
+			
+		Bprint(&bso, "%.6llux\t%-20s | %P\n", (vlong)sym->value, sym->name, p);
+		for(p = p->link; p != P; p = p->link) {
+			if(p->link != P)
+				epc = p->link->pc;
+			else
+				epc = sym->value + sym->size;
+			Bprint(&bso, "%.6ux\t", p->pc);
+			q = sym->p + p->pc - sym->value;
+			n = epc - p->pc;
+			Bprint(&bso, "%-20.*I | %P\n", n, q, p);
+			addr += n;
+		}
+	}
+
+	if(addr < eaddr) {
+		Bprint(&bso, "%-20s %.8llux|", "_", (vlong)addr);
+		for(; addr < eaddr; addr++)
+			Bprint(&bso, " %.2ux", 0);
+	}
+	Bflush(&bso);
+}
+			
+void
+datblk(int32 addr, int32 size)
+{
+	Sym *sym;
+	int32 eaddr;
+	uchar *p, *ep;
+
+	if(debug['a'])
+		Bprint(&bso, "datblk [%#x,%#x) at offset %#llx\n", addr, addr+size, seek(cout, 0, 1));
+
+	blk(datap, addr, size);
+
+	/* again for printing */
+	if(!debug['a'])
+		return;
+
+	for(sym = datap; sym != nil; sym = sym->next)
+		if(sym->value >= addr)
+			break;
+
+	eaddr = addr + size;
+	for(; sym != nil; sym = sym->next) {
+		if(sym->value >= eaddr)
+			break;
+		if(addr < sym->value) {
+			Bprint(&bso, "%-20s %.8ux| 00 ...\n", "(pre-pad)", addr);
+			addr = sym->value;
+		}
+		Bprint(&bso, "%-20s %.8ux|", sym->name, addr);
+		p = sym->p;
+		ep = p + sym->np;
+		while(p < ep)
+			Bprint(&bso, " %.2ux", *p++);
+		addr += sym->np;
+		for(; addr < sym->value+sym->size; addr++)
+			Bprint(&bso, " %.2ux", 0);
+		Bprint(&bso, "\n");
+	}
+
+	if(addr < eaddr)
+		Bprint(&bso, "%-20s %.8ux| 00 ...\n", "(post-pad)", addr);
+	Bprint(&bso, "%-20s %.8ux|\n", "", eaddr);
+}
+
+void
+strnput(char *s, int n)
+{
+	for(; *s && n > 0; s++) {
+		cput(*s);
+		n--;
+	}
+	while(n > 0) {
+		cput(0);
+		n--;
+	}
+}
+
+vlong
+addstring(Sym *s, char *str)
+{
+	int n;
+	int32 r;
+
+	if(s->type == 0)
+		s->type = SDATA;
+	s->reachable = 1;
+	r = s->size;
+	n = strlen(str)+1;
+	if(strcmp(s->name, ".shstrtab") == 0)
+		elfsetstring(str, r);
+	symgrow(s, r+n);
+	memmove(s->p+r, str, n);
+	s->size += n;
+	return r;
+}
+
+vlong
+adduintxx(Sym *s, uint64 v, int wid)
+{
+	int32 i, r, fl;
+	vlong o;
+	uchar *cast;
+
+	if(s->type == 0)
+		s->type = SDATA;
+	s->reachable = 1;
+	r = s->size;
+	s->size += wid;
+	symgrow(s, s->size);
+	assert(r+wid <= s->size);
+	fl = v;
+	cast = (uchar*)&fl;
+	switch(wid) {
+	case 1:
+		s->p[r] = cast[inuxi1[0]];
+		break;
+	case 2:
+		for(i=0; i<2; i++)
+			s->p[r+i] = cast[inuxi2[i]];
+		break;
+	case 4:
+		for(i=0; i<4; i++)
+			s->p[r+i] = cast[inuxi4[i]];
+		break;
+	case 8:
+		o = v;
+		cast = (uchar*)&o;
+		for(i=0; i<8; i++)
+			s->p[r+i] = cast[inuxi8[i]];
+		break;
+	}
+	return r;
+}
+
+vlong
+adduint8(Sym *s, uint8 v)
+{
+	return adduintxx(s, v, 1);
+}
+
+vlong
+adduint16(Sym *s, uint16 v)
+{
+	return adduintxx(s, v, 2);
+}
+
+vlong
+adduint32(Sym *s, uint32 v)
+{
+	return adduintxx(s, v, 4);
+}
+
+vlong
+adduint64(Sym *s, uint64 v)
+{
+	return adduintxx(s, v, 8);
+}
+
+vlong
+addaddrplus(Sym *s, Sym *t, int32 add)
+{
+	vlong i;
+	Reloc *r;
+
+	if(s->type == 0)
+		s->type = SDATA;
+	s->reachable = 1;
+	i = s->size;
+	s->size += PtrSize;
+	symgrow(s, s->size);
+	r = addrel(s);
+	r->sym = t;
+	r->off = i;
+	r->siz = PtrSize;
+	r->type = D_ADDR;
+	r->add = add;
+	return i;
+}
+
+vlong
+addpcrelplus(Sym *s, Sym *t, int32 add)
+{
+	vlong i;
+	Reloc *r;
+	
+	if(s->type == 0)
+		s->type = SDATA;
+	s->reachable = 1;
+	i = s->size;
+	s->size += 4;
+	symgrow(s, s->size);
+	r = addrel(s);
+	r->sym = t;
+	r->off = i;
+	r->add = add;
+	r->type = D_PCREL;
+	r->siz = 4;
+	return i;
+}
+
+vlong
+addaddr(Sym *s, Sym *t)
+{
+	return addaddrplus(s, t, 0);
+}
+
+vlong
+addsize(Sym *s, Sym *t)
+{
+	vlong i;
+	Reloc *r;
+
+	if(s->type == 0)
+		s->type = SDATA;
+	s->reachable = 1;
+	i = s->size;
+	s->size += PtrSize;
+	symgrow(s, s->size);
+	r = addrel(s);
+	r->sym = t;
+	r->off = i;
+	r->siz = PtrSize;
+	r->type = D_SIZE;
+	return i;
+}
+
+void
+dodata(void)
+{
+	int32 h, t, datsize;
+	Section *sect;
+	Sym *s, *last, **l;
+
+	if(debug['v'])
+		Bprint(&bso, "%5.2f dodata\n", cputime());
+	Bflush(&bso);
+
+	last = nil;
+	datap = nil;
+	for(h=0; h<NHASH; h++) {
+		for(s=hash[h]; s!=S; s=s->hash){
+			if(!s->reachable || s->special)
+				continue;
+			if(STEXT < s->type && s->type < SXREF) {
+				if(last == nil)
+					datap = s;
+				else
+					last->next = s;
+				s->next = nil;
+				last = s;
+			}
+		}
+	}
+
+	for(s = datap; s != nil; s = s->next) {
+		if(s->np > 0 && s->type == SBSS)	// TODO: necessary?
+			s->type = SDATA;
+		if(s->np > s->size)
+			diag("%s: initialize bounds (%lld < %d)",
+				s->name, (vlong)s->size, s->np);
+	}
+	
+	/*
+	 * now that we have the datap list, but before we start
+	 * to assign addresses, record all the necessary
+	 * dynamic relocations.  these will grow the relocation
+	 * symbol, which is itself data.
+	 */
+	dynreloc();
+	
+	/* some symbols may no longer belong in datap (Mach-O) */
+	for(l=&datap; (s=*l) != nil; ) {
+		if(s->type <= STEXT || SXREF <= s->type)
+			*l = s->next;
+		else
+			l = &s->next;
+	}
+	*l = nil;
+
+	datap = datsort(datap);
+
+	/*
+	 * allocate data sections.  list is sorted by type,
+	 * so we can just walk it for each piece we want to emit.
+	 */
+
+	/* read-only data */
+	sect = addsection(&segtext, ".rodata", 06);
+	sect->vaddr = 0;
+	datsize = 0;
+	s = datap;
+	for(; s != nil && s->type < SDATA; s = s->next) {
+		s->type = SRODATA;
+		t = rnd(s->size, 4);
+		s->size = t;
+		s->value = datsize;
+		datsize += t;
+	}
+	sect->len = datsize - sect->vaddr;
+	
+	/* data */
+	datsize = 0;
+	sect = addsection(&segdata, ".data", 06);
+	sect->vaddr = 0;
+	for(; s != nil && s->type < SBSS; s = s->next) {
+		s->type = SDATA;
+		t = s->size;
+		if(t == 0 && s->name[0] != '.') {
+			diag("%s: no size", s->name);
+			t = 1;
+		}
+		if(t & 1)
+			;
+		else if(t & 2)
+			datsize = rnd(datsize, 2);
+		else if(t & 4)
+			datsize = rnd(datsize, 4);
+		else
+			datsize = rnd(datsize, 8);
+		s->value = datsize;
+		datsize += t;
+	}
+	sect->len = datsize - sect->vaddr;
+
+	/* bss */
+	sect = addsection(&segdata, ".bss", 06);
+	sect->vaddr = datsize;
+	for(; s != nil; s = s->next) {
+		if(s->type != SBSS) {
+			cursym = s;
+			diag("unexpected symbol type %d", s->type);
+		}
+		t = s->size;
+		if(t & 1)
+			;
+		else if(t & 2)
+			datsize = rnd(datsize, 2);
+		else if(t & 4)
+			datsize = rnd(datsize, 4);
+		else
+			datsize = rnd(datsize, 8);
+		s->size = t;
+		s->value = datsize;
+		datsize += t;
+	}
+	sect->len = datsize - sect->vaddr;
+}
+
+// assign addresses to text
+void
+textaddress(void)
+{
+	uvlong va;
+	Prog *p;
+	Section *sect;
+	Sym *sym, *sub;
+
+	addsection(&segtext, ".text", 05);
+
+	// Assign PCs in text segment.
+	// Could parallelize, by assigning to text 
+	// and then letting threads copy down, but probably not worth it.
+	sect = segtext.sect;
+	va = INITTEXT;
+	sect->vaddr = va;
+	for(sym = textp; sym != nil; sym = sym->next) {
+		if(sym->type & SSUB)
+			continue;
+		sym->value = 0;
+		for(sub = sym; sub != S; sub = sub->sub) {
+			sub->value += va;
+			for(p = sub->text; p != P; p = p->link)
+				p->pc += sub->value;
+		}
+		if(sym->size == 0 && sym->sub != S) {
+			cursym = sym;
+		}
+		va += sym->size;
+	}
+	sect->len = va - sect->vaddr;
+}
+
+// assign addresses
+void
+address(void)
+{
+	Section *s, *text, *data, *rodata, *bss;
+	Sym *sym, *sub;
+	uvlong va;
+
+	va = INITTEXT;
+	segtext.rwx = 05;
+	segtext.vaddr = va;
+	segtext.fileoff = HEADR;
+	for(s=segtext.sect; s != nil; s=s->next) {
+		s->vaddr = va;
+		va += s->len;
+		segtext.len = va - INITTEXT;
+		va = rnd(va, INITRND);
+	}
+	segtext.filelen = segtext.len;
+
+	segdata.rwx = 06;
+	segdata.vaddr = va;
+	segdata.fileoff = va - segtext.vaddr + segtext.fileoff;
+	if(thechar == '8' && HEADTYPE == 10)	// Windows PE
+		segdata.fileoff = segtext.fileoff + rnd(segtext.len, PEFILEALIGN);
+	if(thechar == '8' && HEADTYPE == 2) {	// Plan 9		
+		segdata.vaddr = va = rnd(va, 4096);
+		segdata.fileoff = segtext.fileoff + segtext.filelen;
+	}
+	for(s=segdata.sect; s != nil; s=s->next) {
+		s->vaddr = va;
+		va += s->len;
+		segdata.len = va - segdata.vaddr;
+	}
+	segdata.filelen = segdata.sect->len;	// assume .data is first
+	
+	text = segtext.sect;
+	rodata = segtext.sect->next;
+	data = segdata.sect;
+	bss = segdata.sect->next;
+
+	for(sym = datap; sym != nil; sym = sym->next) {
+		cursym = sym;
+		if(sym->type < SDATA)
+			sym->value += rodata->vaddr;
+		else
+			sym->value += data->vaddr;
+		for(sub = sym->sub; sub != nil; sub = sub->sub)
+			sub->value += sym->value;
+	}
+	
+	xdefine("text", STEXT, text->vaddr);
+	xdefine("etext", STEXT, text->vaddr + text->len);
+	xdefine("rodata", SRODATA, rodata->vaddr);
+	xdefine("erodata", SRODATA, rodata->vaddr + rodata->len);
+	xdefine("data", SBSS, data->vaddr);
+	xdefine("edata", SBSS, data->vaddr + data->len);
+	xdefine("end", SBSS, segdata.vaddr + segdata.len);
+
+	sym = lookup("pclntab", 0);
+	xdefine("epclntab", SRODATA, sym->value + sym->size);
+	sym = lookup("symtab", 0);
+	xdefine("esymtab", SRODATA, sym->value + sym->size);
+}
diff --git a/src/cmd/ld/dwarf.c b/src/cmd/ld/dwarf.c
new file mode 100644
index 000000000..506c6e5db
--- /dev/null
+++ b/src/cmd/ld/dwarf.c
@@ -0,0 +1,2547 @@
+// Copyright 2010 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.
+
+// TODO/NICETOHAVE:
+//   - eliminate DW_CLS_ if not used
+//   - package info in compilation units
+//   - assign global variables and types to their packages
+//   - (upstream) type info for C parts of runtime
+//   - gdb uses c syntax, meaning clumsy quoting is needed for go identifiers. eg
+//     ptype struct '[]uint8' and qualifiers need to be quoted away
+//   - lexical scoping is lost, so gdb gets confused as to which 'main.i' you mean.
+//   - file:line info for variables
+//   - make strings a typedef so prettyprinters can see the underlying string type
+//
+#include	"l.h"
+#include	"lib.h"
+#include	"../ld/dwarf.h"
+#include	"../ld/dwarf_defs.h"
+#include	"../ld/elf.h"
+#include	"../ld/macho.h"
+
+/*
+ * Offsets and sizes of the debug_* sections in the cout file.
+ */
+
+static vlong abbrevo;
+static vlong abbrevsize;
+static vlong lineo;
+static vlong linesize;
+static vlong infoo;	// also the base for DWDie->offs and reference attributes.
+static vlong infosize;
+static vlong frameo;
+static vlong framesize;
+static vlong pubnameso;
+static vlong pubnamessize;
+static vlong pubtypeso;
+static vlong pubtypessize;
+static vlong arangeso;
+static vlong arangessize;
+static vlong gdbscripto;
+static vlong gdbscriptsize;
+
+static char  gdbscript[1024];
+
+/*
+ *  Basic I/O
+ */
+
+static void
+addrput(vlong addr)
+{
+	switch(PtrSize) {
+	case 4:
+		LPUT(addr);
+		break;
+	case 8:
+		VPUT(addr);
+		break;
+	}
+}
+
+static int
+uleb128enc(uvlong v, char* dst)
+{
+	uint8 c, len;
+
+	len = 0;
+	do {
+		c = v & 0x7f;
+		v >>= 7;
+		if (v)
+			c |= 0x80;
+		if (dst)
+			*dst++ = c;
+		len++;
+	} while (c & 0x80);
+	return len;
+};
+
+static int
+sleb128enc(vlong v, char *dst)
+{
+	uint8 c, s, len;
+
+	len = 0;
+	do {
+		c = v & 0x7f;
+		s = v & 0x40;
+		v >>= 7;
+		if ((v != -1 || !s) && (v != 0 || s))
+			c |= 0x80;
+		if (dst)
+			*dst++ = c;
+		len++;
+	} while(c & 0x80);
+	return len;
+}
+
+static void
+uleb128put(vlong v)
+{
+	char buf[10];
+	strnput(buf, uleb128enc(v, buf));
+}
+
+static void
+sleb128put(vlong v)
+{
+	char buf[10];
+	strnput(buf, sleb128enc(v, buf));
+}
+
+/*
+ * Defining Abbrevs.  This is hardcoded, and there will be
+ * only a handful of them.  The DWARF spec places no restriction on
+ * the ordering of atributes in the Abbrevs and DIEs, and we will
+ * always write them out in the order of declaration in the abbrev.
+ * This implementation relies on tag, attr < 127, so they serialize as
+ * a char.  Higher numbered user-defined tags or attributes can be used
+ * for storing internal data but won't be serialized.
+ */
+typedef struct DWAttrForm DWAttrForm;
+struct DWAttrForm {
+	uint8 attr;
+	uint8 form;
+};
+
+// Index into the abbrevs table below.
+// Keep in sync with ispubname() and ispubtype() below.
+// ispubtype considers >= NULLTYPE public
+enum
+{
+	DW_ABRV_NULL,
+	DW_ABRV_COMPUNIT,
+	DW_ABRV_FUNCTION,
+	DW_ABRV_VARIABLE,
+	DW_ABRV_AUTO,
+	DW_ABRV_PARAM,
+	DW_ABRV_STRUCTFIELD,
+	DW_ABRV_FUNCTYPEPARAM,
+	DW_ABRV_DOTDOTDOT,
+	DW_ABRV_ARRAYRANGE,
+	DW_ABRV_NULLTYPE,
+	DW_ABRV_BASETYPE,
+	DW_ABRV_ARRAYTYPE,
+	DW_ABRV_CHANTYPE,
+	DW_ABRV_FUNCTYPE,
+	DW_ABRV_IFACETYPE,
+	DW_ABRV_MAPTYPE,
+	DW_ABRV_PTRTYPE,
+	DW_ABRV_SLICETYPE,
+	DW_ABRV_STRINGTYPE,
+	DW_ABRV_STRUCTTYPE,
+	DW_ABRV_TYPEDECL,
+	DW_NABRV
+};
+
+typedef struct DWAbbrev DWAbbrev;
+static struct DWAbbrev {
+	uint8 tag;
+	uint8 children;
+	DWAttrForm attr[30];
+} abbrevs[DW_NABRV] = {
+	/* The mandatory DW_ABRV_NULL entry. */
+	{ 0 },
+	/* COMPUNIT */
+	{
+		DW_TAG_compile_unit, DW_CHILDREN_yes,
+		DW_AT_name,	 DW_FORM_string,
+		DW_AT_language,	 DW_FORM_data1,
+		DW_AT_low_pc,	 DW_FORM_addr,
+		DW_AT_high_pc,	 DW_FORM_addr,
+		DW_AT_stmt_list, DW_FORM_data4,
+		0, 0
+	},
+	/* FUNCTION */
+	{
+		DW_TAG_subprogram, DW_CHILDREN_yes,
+		DW_AT_name,	 DW_FORM_string,
+		DW_AT_low_pc,	 DW_FORM_addr,
+		DW_AT_high_pc,	 DW_FORM_addr,
+		DW_AT_external,	 DW_FORM_flag,
+		0, 0
+	},
+	/* VARIABLE */
+	{
+		DW_TAG_variable, DW_CHILDREN_no,
+		DW_AT_name,	 DW_FORM_string,
+		DW_AT_location,	 DW_FORM_block1,
+		DW_AT_type,	 DW_FORM_ref_addr,
+		DW_AT_external,	 DW_FORM_flag,
+		0, 0
+	},
+	/* AUTO */
+	{
+		DW_TAG_variable, DW_CHILDREN_no,
+		DW_AT_name,	 DW_FORM_string,
+		DW_AT_location,	 DW_FORM_block1,
+		DW_AT_type,	 DW_FORM_ref_addr,
+		0, 0
+	},
+	/* PARAM */
+	{
+		DW_TAG_formal_parameter, DW_CHILDREN_no,
+		DW_AT_name,	 DW_FORM_string,
+		DW_AT_location,	 DW_FORM_block1,
+		DW_AT_type,	 DW_FORM_ref_addr,
+		0, 0
+	},
+	/* STRUCTFIELD */
+	{
+		DW_TAG_member,	DW_CHILDREN_no,
+		DW_AT_name,	DW_FORM_string,
+		DW_AT_data_member_location, DW_FORM_block1,
+		DW_AT_type,	 DW_FORM_ref_addr,
+		0, 0
+	},
+	/* FUNCTYPEPARAM */
+	{
+		DW_TAG_formal_parameter, DW_CHILDREN_no,
+		// No name!
+		DW_AT_type,	 DW_FORM_ref_addr,
+		0, 0
+	},
+
+	/* DOTDOTDOT */
+	{
+		DW_TAG_unspecified_parameters, DW_CHILDREN_no,
+		0, 0
+	},
+	/* ARRAYRANGE */
+	{
+		DW_TAG_subrange_type, DW_CHILDREN_no,
+		// No name!
+		DW_AT_type,	 DW_FORM_ref_addr,
+		DW_AT_upper_bound, DW_FORM_data1,
+		0, 0
+	},
+
+	// Below here are the types considered public by ispubtype
+	/* NULLTYPE */
+	{
+		DW_TAG_unspecified_type, DW_CHILDREN_no,
+		DW_AT_name,	DW_FORM_string,
+		0, 0
+	},
+	/* BASETYPE */
+	{
+		DW_TAG_base_type, DW_CHILDREN_no,
+		DW_AT_name,	 DW_FORM_string,
+		DW_AT_encoding,	 DW_FORM_data1,
+		DW_AT_byte_size, DW_FORM_data1,
+		0, 0
+	},
+	/* ARRAYTYPE */
+	// child is subrange with upper bound
+	{
+		DW_TAG_array_type, DW_CHILDREN_yes,
+		DW_AT_name,	DW_FORM_string,
+		DW_AT_type,	DW_FORM_ref_addr,
+		DW_AT_byte_size, DW_FORM_udata,
+		0, 0
+	},
+
+	/* CHANTYPE */
+	{
+		DW_TAG_typedef, DW_CHILDREN_no,
+		DW_AT_name,	DW_FORM_string,
+		DW_AT_type,	DW_FORM_ref_addr,
+		0, 0
+	},
+
+	/* FUNCTYPE */
+	{
+		DW_TAG_subroutine_type, DW_CHILDREN_yes,
+		DW_AT_name,	DW_FORM_string,
+//		DW_AT_type,	DW_FORM_ref_addr,
+		0, 0
+	},
+
+	/* IFACETYPE */
+	{
+		DW_TAG_typedef, DW_CHILDREN_yes,
+		DW_AT_name,	 DW_FORM_string,
+		DW_AT_type,	DW_FORM_ref_addr,
+		0, 0
+	},
+
+	/* MAPTYPE */
+	{
+		DW_TAG_typedef, DW_CHILDREN_no,
+		DW_AT_name,	DW_FORM_string,
+		DW_AT_type,	DW_FORM_ref_addr,
+		0, 0
+	},
+
+	/* PTRTYPE */
+	{
+		DW_TAG_pointer_type, DW_CHILDREN_no,
+		DW_AT_name,	DW_FORM_string,
+		DW_AT_type,	DW_FORM_ref_addr,
+		0, 0
+	},
+
+	/* SLICETYPE */
+	{
+		DW_TAG_structure_type, DW_CHILDREN_yes,
+		DW_AT_name,	DW_FORM_string,
+		DW_AT_byte_size, DW_FORM_udata,
+		0, 0
+	},
+
+	/* STRINGTYPE */
+	{
+		DW_TAG_structure_type, DW_CHILDREN_yes,
+		DW_AT_name,	DW_FORM_string,
+		DW_AT_byte_size, DW_FORM_udata,
+		0, 0
+	},
+
+	/* STRUCTTYPE */
+	{
+		DW_TAG_structure_type, DW_CHILDREN_yes,
+		DW_AT_name,	DW_FORM_string,
+		DW_AT_byte_size, DW_FORM_udata,
+		0, 0
+	},
+
+	/* TYPEDECL */
+	{
+		DW_TAG_typedef, DW_CHILDREN_no,
+		DW_AT_name,	DW_FORM_string,
+		DW_AT_type,	DW_FORM_ref_addr,
+		0, 0
+	},
+};
+
+static void
+writeabbrev(void)
+{
+	int i, n;
+
+	abbrevo = cpos();
+	for (i = 1; i < DW_NABRV; i++) {
+		// See section 7.5.3
+		uleb128put(i);
+		uleb128put(abbrevs[i].tag);
+		cput(abbrevs[i].children);
+		// 0 is not a valid attr or form, and DWAbbrev.attr is
+		// 0-terminated, so we can treat it as a string
+		n = strlen((char*)abbrevs[i].attr) / 2;
+		strnput((char*)abbrevs[i].attr,
+			(n+1) * sizeof(DWAttrForm));
+	}
+	cput(0);
+	abbrevsize = cpos() - abbrevo;
+}
+
+/*
+ * Debugging Information Entries and their attributes.
+ */
+
+enum
+{
+	HASHSIZE = 107
+};
+
+static uint32
+hashstr(char* s)
+{
+	uint32 h;
+
+	h = 0;
+	while (*s)
+		h = h+h+h + *s++;
+	return h % HASHSIZE;
+}
+
+// For DW_CLS_string and _block, value should contain the length, and
+// data the data, for _reference, value is 0 and data is a DWDie* to
+// the referenced instance, for all others, value is the whole thing
+// and data is null.
+
+typedef struct DWAttr DWAttr;
+struct DWAttr {
+	DWAttr *link;
+	uint8 atr;  // DW_AT_
+	uint8 cls;  // DW_CLS_
+	vlong value;
+	char *data;
+};
+
+typedef struct DWDie DWDie;
+struct DWDie {
+	int abbrev;
+	DWDie *link;
+	DWDie *child;
+	DWAttr *attr;
+	// offset into .debug_info section, i.e relative to
+	// infoo. only valid after call to putdie()
+	vlong offs;
+	DWDie **hash;  // optional index of children by name, enabled by mkindex()
+	DWDie *hlink;  // bucket chain in parent's index
+};
+
+/*
+ * Root DIEs for compilation units, types and global variables.
+ */
+
+static DWDie dwroot;
+static DWDie dwtypes;
+static DWDie dwglobals;
+
+static DWAttr*
+newattr(DWDie *die, uint8 attr, int cls, vlong value, char *data)
+{
+	DWAttr *a;
+
+	a = mal(sizeof *a);
+	a->link = die->attr;
+	die->attr = a;
+	a->atr = attr;
+	a->cls = cls;
+	a->value = value;
+	a->data = data;
+	return a;
+}
+
+// Each DIE (except the root ones) has at least 1 attribute: its
+// name. getattr moves the desired one to the front so
+// frequently searched ones are found faster.
+static DWAttr*
+getattr(DWDie *die, uint8 attr)
+{
+	DWAttr *a, *b;
+
+	if (die->attr->atr == attr)
+		return die->attr;
+
+	a = die->attr;
+	b = a->link;
+	while (b != nil) {
+		if (b->atr == attr) {
+			a->link = b->link;
+			b->link = die->attr;
+			die->attr = b;
+			return b;
+		}
+		a = b;
+		b = b->link;
+	}
+	return nil;
+}
+
+static void
+delattr(DWDie *die, uint8 attr)
+{
+	DWAttr **a;
+
+	a = &die->attr;
+	while (*a != nil)
+		if ((*a)->atr == attr)
+			*a = (*a)->link;
+		else
+			a = &((*a)->link);
+}
+
+// Every DIE has at least a DW_AT_name attribute (but it will only be
+// written out if it is listed in the abbrev).	If its parent is
+// keeping an index, the new DIE will be inserted there.
+static DWDie*
+newdie(DWDie *parent, int abbrev, char *name)
+{
+	DWDie *die;
+	int h;
+
+	die = mal(sizeof *die);
+	die->abbrev = abbrev;
+	die->link = parent->child;
+	parent->child = die;
+
+	newattr(die, DW_AT_name, DW_CLS_STRING, strlen(name), name);
+
+	if (parent->hash) {
+		h = hashstr(name);
+		die->hlink = parent->hash[h];
+		parent->hash[h] = die;
+	}
+
+	return die;
+}
+
+static void
+mkindex(DWDie *die)
+{
+	die->hash = mal(HASHSIZE * sizeof(DWDie*));
+}
+
+// Find child by AT_name using hashtable if available or linear scan
+// if not.
+static DWDie*
+find(DWDie *die, char* name)
+{
+	DWDie *a, *b;
+	int h;
+
+	if (die->hash == nil) {
+		for (a = die->child; a != nil; a = a->link)
+			if (strcmp(name, getattr(a, DW_AT_name)->data) == 0)
+				return a;
+		return nil;
+	}
+
+	h = hashstr(name);
+	a = die->hash[h];
+
+	if (a == nil)
+		return nil;
+
+
+	if (strcmp(name, getattr(a, DW_AT_name)->data) == 0)
+		return a;
+
+	// Move found ones to head of the list.
+	b = a->hlink;
+	while (b != nil) {
+		if (strcmp(name, getattr(b, DW_AT_name)->data) == 0) {
+			a->hlink = b->hlink;
+			b->hlink = die->hash[h];
+			die->hash[h] = b;
+			return b;
+		}
+		a = b;
+		b = b->hlink;
+	}
+	return nil;
+}
+
+static DWDie*
+find_or_diag(DWDie *die, char* name)
+{
+	DWDie *r;
+	r = find(die, name);
+	if (r == nil)
+		diag("dwarf find: %s has no %s", getattr(die, DW_AT_name)->data, name);
+	return r;
+}
+
+static DWAttr*
+newrefattr(DWDie *die, uint8 attr, DWDie* ref)
+{
+	if (ref == nil)
+		return nil;
+	return newattr(die, attr, DW_CLS_REFERENCE, 0, (char*)ref);
+}
+
+static int fwdcount;
+
+static void
+putattr(int form, int cls, vlong value, char *data)
+{
+	switch(form) {
+	case DW_FORM_addr:	// address
+		addrput(value);
+		break;
+
+	case DW_FORM_block1:	// block
+		value &= 0xff;
+		cput(value);
+		while(value--)
+			cput(*data++);
+		break;
+
+	case DW_FORM_block2:	// block
+		value &= 0xffff;
+		WPUT(value);
+		while(value--)
+			cput(*data++);
+		break;
+
+	case DW_FORM_block4:	// block
+		value &= 0xffffffff;
+		LPUT(value);
+		while(value--)
+			cput(*data++);
+		break;
+
+	case DW_FORM_block:	// block
+		uleb128put(value);
+		while(value--)
+			cput(*data++);
+		break;
+
+	case DW_FORM_data1:	// constant
+		cput(value);
+		break;
+
+	case DW_FORM_data2:	// constant
+		WPUT(value);
+		break;
+
+	case DW_FORM_data4:	// constant, {line,loclist,mac,rangelist}ptr
+		LPUT(value);
+		break;
+
+	case DW_FORM_data8:	// constant, {line,loclist,mac,rangelist}ptr
+		VPUT(value);
+		break;
+
+	case DW_FORM_sdata:	// constant
+		sleb128put(value);
+		break;
+
+	case DW_FORM_udata:	// constant
+		uleb128put(value);
+		break;
+
+	case DW_FORM_string:	// string
+		strnput(data, value+1);
+		break;
+
+	case DW_FORM_flag:	// flag
+		cput(value?1:0);
+		break;
+
+	case DW_FORM_ref_addr:	// reference to a DIE in the .info section
+		if (data == nil) {
+			diag("null dwarf reference");
+			LPUT(0);  // invalid dwarf, gdb will complain.
+		} else {
+			if (((DWDie*)data)->offs == 0)
+				fwdcount++;
+			LPUT(((DWDie*)data)->offs);
+		}
+		break;
+
+	case DW_FORM_ref1:	// reference within the compilation unit
+	case DW_FORM_ref2:	// reference
+	case DW_FORM_ref4:	// reference
+	case DW_FORM_ref8:	// reference
+	case DW_FORM_ref_udata:	// reference
+
+	case DW_FORM_strp:	// string
+	case DW_FORM_indirect:	// (see Section 7.5.3)
+	default:
+		diag("Unsupported atribute form %d / class %d", form, cls);
+		errorexit();
+	}
+}
+
+// Note that we can (and do) add arbitrary attributes to a DIE, but
+// only the ones actually listed in the Abbrev will be written out.
+static void
+putattrs(int abbrev, DWAttr* attr)
+{
+	DWAttr *attrs[DW_AT_recursive + 1];
+	DWAttrForm* af;
+
+	memset(attrs, 0, sizeof attrs);
+	for( ; attr; attr = attr->link)
+		if (attr->atr < nelem(attrs))
+			attrs[attr->atr] = attr;
+
+	for(af = abbrevs[abbrev].attr; af->attr; af++)
+		if (attrs[af->attr])
+			putattr(af->form,
+				attrs[af->attr]->cls,
+				attrs[af->attr]->value,
+				attrs[af->attr]->data);
+		else
+			putattr(af->form, 0, 0, 0);
+}
+
+static void putdie(DWDie* die);
+
+static void
+putdies(DWDie* die)
+{
+	for(; die; die = die->link)
+		putdie(die);
+}
+
+static void
+putdie(DWDie* die)
+{
+	die->offs = cpos() - infoo;
+	uleb128put(die->abbrev);
+	putattrs(die->abbrev, die->attr);
+	if (abbrevs[die->abbrev].children) {
+		putdies(die->child);
+		cput(0);
+	}
+}
+
+static void
+reverselist(DWDie** list)
+{
+	DWDie *curr, *prev;
+
+	curr = *list;
+	prev = nil;
+	while(curr != nil) {
+		DWDie* next = curr->link;
+		curr->link = prev;
+		prev = curr;
+		curr = next;
+	}
+	*list = prev;
+}
+
+static void
+reversetree(DWDie** list)
+{
+	 DWDie *die;
+
+	 reverselist(list);
+	 for (die = *list; die != nil; die = die->link)
+		 if (abbrevs[die->abbrev].children)
+			 reversetree(&die->child);
+}
+
+static void
+newmemberoffsetattr(DWDie *die, int32 offs)
+{
+	char block[10];
+	int i;
+
+	i = 0;
+	if (offs != 0) {
+		block[i++] = DW_OP_consts;
+		i += sleb128enc(offs, block+i);
+		block[i++] = DW_OP_plus;
+	}
+	newattr(die, DW_AT_data_member_location, DW_CLS_BLOCK, i, mal(i));
+	memmove(die->attr->data, block, i);
+}
+
+// GDB doesn't like DW_FORM_addr for DW_AT_location, so emit a
+// location expression that evals to a const.
+static void
+newabslocexprattr(DWDie *die, vlong addr)
+{
+	char block[10];
+	int i;
+
+	i = 0;
+	block[i++] = DW_OP_constu;
+	i += uleb128enc(addr, block+i);
+	newattr(die, DW_AT_location, DW_CLS_BLOCK, i, mal(i));
+	memmove(die->attr->data, block, i);
+}
+
+// Decoding the type.* symbols.	 This has to be in sync with
+// ../../pkg/runtime/type.go, or more specificaly, with what
+// ../gc/reflect.c stuffs in these.
+
+enum {
+	KindBool = 1,
+	KindInt,
+	KindInt8,
+	KindInt16,
+	KindInt32,
+	KindInt64,
+	KindUint,
+	KindUint8,
+	KindUint16,
+	KindUint32,
+	KindUint64,
+	KindUintptr,
+	KindFloat,
+	KindFloat32,
+	KindFloat64,
+	KindComplex,
+	KindComplex64,
+	KindComplex128,
+	KindArray,
+	KindChan,
+	KindFunc,
+	KindInterface,
+	KindMap,
+	KindPtr,
+	KindSlice,
+	KindString,
+	KindStruct,
+	KindUnsafePointer,
+
+	KindNoPointers = 1<<7,
+};
+
+static Reloc*
+decode_reloc(Sym *s, int32 off)
+{
+	int i;
+
+	for (i = 0; i < s->nr; i++)
+		if (s->r[i].off == off)
+			return s->r + i;
+	return nil;
+}
+
+static uvlong
+decode_inuxi(uchar* p, int sz)
+{
+	uint64 v;
+	uint32 l;
+	uchar *cast, *inuxi;
+	int i;
+
+	v = l = 0;
+	cast = nil;
+	inuxi = nil;
+	switch (sz) {
+	case 2:
+		cast = (uchar*)&l;
+		inuxi = inuxi2;
+		break;
+	case 4:
+		cast = (uchar*)&l;
+		inuxi = inuxi4;
+		break;
+	case 8:
+		cast = (uchar*)&v;
+		inuxi = inuxi8;
+		break;
+	default:
+		diag("decode inuxi %d", sz);
+		errorexit();
+	}
+	for (i = 0; i < sz; i++)
+		cast[inuxi[i]] = p[i];
+	if (sz == 8)
+		return v;
+	return l;
+}
+
+// Type.commonType.kind
+static uint8
+decodetype_kind(Sym *s)
+{
+	return s->p[3*PtrSize + 7] & ~KindNoPointers;	//  0x13 / 0x1f
+}
+
+// Type.commonType.size
+static vlong
+decodetype_size(Sym *s)
+{
+	return decode_inuxi(s->p + 2*PtrSize, PtrSize);	 // 0x8 / 0x10
+}
+
+// Type.ArrayType.elem and Type.SliceType.Elem
+static Sym*
+decodetype_arrayelem(Sym *s)
+{
+	return decode_reloc(s, 5*PtrSize + 8)->sym;	// 0x1c / 0x30
+}
+
+static vlong
+decodetype_arraylen(Sym *s)
+{
+	return decode_inuxi(s->p + 6*PtrSize + 8, PtrSize);
+}
+
+// Type.PtrType.elem
+static Sym*
+decodetype_ptrelem(Sym *s)
+{
+	return decode_reloc(s, 5*PtrSize + 8)->sym;	// 0x1c / 0x30
+}
+
+// Type.MapType.key, elem
+static Sym*
+decodetype_mapkey(Sym *s)
+{
+	return decode_reloc(s, 5*PtrSize + 8)->sym;	// 0x1c / 0x30
+}
+static Sym*
+decodetype_mapvalue(Sym *s)
+{
+	return decode_reloc(s, 6*PtrSize + 8)->sym;	// 0x20 / 0x38
+}
+
+// Type.ChanType.elem
+static Sym*
+decodetype_chanelem(Sym *s)
+{
+	return decode_reloc(s, 5*PtrSize + 8)->sym;	// 0x1c / 0x30
+}
+
+// Type.FuncType.dotdotdot
+static int
+decodetype_funcdotdotdot(Sym *s)
+{
+	return s->p[5*PtrSize + 8];
+}
+
+// Type.FuncType.in.len
+static int
+decodetype_funcincount(Sym *s)
+{
+	return decode_inuxi(s->p + 7*PtrSize + 8, 4);
+}
+
+static int
+decodetype_funcoutcount(Sym *s)
+{
+	return decode_inuxi(s->p + 8*PtrSize + 16, 4);
+}
+
+static Sym*
+decodetype_funcintype(Sym *s, int i)
+{
+	Reloc *r;
+
+	r = decode_reloc(s, 6*PtrSize + 8);
+	return decode_reloc(r->sym, r->add + i * PtrSize)->sym;
+}
+
+static Sym*
+decodetype_funcouttype(Sym *s, int i)
+{
+	Reloc *r;
+
+	r = decode_reloc(s, 7*PtrSize + 16);
+	return decode_reloc(r->sym, r->add + i * PtrSize)->sym;
+}
+
+// Type.StructType.fields.Slice::len
+static int
+decodetype_structfieldcount(Sym *s)
+{
+	return decode_inuxi(s->p + 6*PtrSize + 8, 4);  //  0x20 / 0x38
+}
+
+// Type.StructType.fields[]-> name, typ and offset. sizeof(structField) =  5*PtrSize
+static char*
+decodetype_structfieldname(Sym *s, int i)
+{
+	Reloc* r;
+
+	r = decode_reloc(s, 6*PtrSize + 0x10 + i*5*PtrSize);   // go.string."foo"  0x28 / 0x40
+	if (r == nil)				// embedded structs have a nil name.
+		return nil;
+	r = decode_reloc(r->sym, 0);		// string."foo"
+	if (r == nil)				// shouldn't happen.
+		return nil;
+	return (char*)r->sym->p;		// the c-string
+}
+
+static Sym*
+decodetype_structfieldtype(Sym *s, int i)
+{
+	return decode_reloc(s, 8*PtrSize + 0x10 + i*5*PtrSize)->sym;	 //   0x30 / 0x50
+}
+
+static vlong
+decodetype_structfieldoffs(Sym *s, int i)
+{
+	return decode_inuxi(s->p + 10*PtrSize + 0x10 + i*5*PtrSize, 4);	 // 0x38  / 0x60
+}
+
+// InterfaceTYpe.methods.len
+static vlong
+decodetype_ifacemethodcount(Sym *s)
+{
+	return decode_inuxi(s->p + 6*PtrSize + 8, 4);
+}
+
+
+// Fake attributes for slices, maps and channel
+enum {
+	DW_AT_internal_elem_type = 250,	 // channels and slices
+	DW_AT_internal_key_type = 251,	 // maps
+	DW_AT_internal_val_type = 252,	 // maps
+	DW_AT_internal_location = 253,	 // params and locals
+};
+
+static DWDie* defptrto(DWDie *dwtype);	// below
+
+// Define gotype, for composite ones recurse into constituents.
+static DWDie*
+defgotype(Sym *gotype)
+{
+	DWDie *die, *fld;
+	Sym *s;
+	char *name, *f;
+	uint8 kind;
+	vlong bytesize;
+	int i, nfields;
+
+	if (gotype == nil)
+		return find_or_diag(&dwtypes, "<unspecified>");
+
+	if (strncmp("type.", gotype->name, 5) != 0) {
+		diag("Type name doesn't start with \".type\": %s", gotype->name);
+		return find_or_diag(&dwtypes, "<unspecified>");
+	}
+	name = gotype->name + 5;  // Altenatively decode from Type.string
+
+	die = find(&dwtypes, name);
+	if (die != nil)
+		return die;
+
+	if (0 && debug['v'] > 2) {
+		print("new type: %s @0x%08x [%d]", gotype->name, gotype->value, gotype->size);
+		for (i = 0; i < gotype->size; i++) {
+			if (!(i%8)) print("\n\t%04x ", i);
+			print("%02x ", gotype->p[i]);
+		}
+		print("\n");
+		for (i = 0; i < gotype->nr; i++) {
+			print("\t0x%02x[%x] %d %s[%llx]\n",
+			      gotype->r[i].off,
+			      gotype->r[i].siz,
+			      gotype->r[i].type,
+			      gotype->r[i].sym->name,
+			      (vlong)gotype->r[i].add);
+		}
+	}
+
+	kind = decodetype_kind(gotype);
+	bytesize = decodetype_size(gotype);
+
+	switch (kind) {
+	case KindBool:
+		die = newdie(&dwtypes, DW_ABRV_BASETYPE, name);
+		newattr(die, DW_AT_encoding,  DW_CLS_CONSTANT, DW_ATE_boolean, 0);
+		newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, bytesize, 0);
+		break;
+
+	case KindInt:
+	case KindInt8:
+	case KindInt16:
+	case KindInt32:
+	case KindInt64:
+		die = newdie(&dwtypes, DW_ABRV_BASETYPE, name);
+		newattr(die, DW_AT_encoding,  DW_CLS_CONSTANT, DW_ATE_signed, 0);
+		newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, bytesize, 0);
+		break;
+
+	case KindUint:
+	case KindUint8:
+	case KindUint16:
+	case KindUint32:
+	case KindUint64:
+	case KindUintptr:
+		die = newdie(&dwtypes, DW_ABRV_BASETYPE, name);
+		newattr(die, DW_AT_encoding,  DW_CLS_CONSTANT, DW_ATE_unsigned, 0);
+		newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, bytesize, 0);
+		break;
+
+	case KindFloat:
+	case KindFloat32:
+	case KindFloat64:
+		die = newdie(&dwtypes, DW_ABRV_BASETYPE, name);
+		newattr(die, DW_AT_encoding,  DW_CLS_CONSTANT, DW_ATE_float, 0);
+		newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, bytesize, 0);
+		break;
+
+	case KindComplex:
+	case KindComplex64:
+	case KindComplex128:
+		die = newdie(&dwtypes, DW_ABRV_BASETYPE, name);
+		newattr(die, DW_AT_encoding,  DW_CLS_CONSTANT, DW_ATE_complex_float, 0);
+		newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, bytesize, 0);
+		break;
+
+	case KindArray:
+		die = newdie(&dwtypes, DW_ABRV_ARRAYTYPE, name);
+		newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, bytesize, 0);
+		s = decodetype_arrayelem(gotype);
+		newrefattr(die, DW_AT_type, defgotype(s));
+		fld = newdie(die, DW_ABRV_ARRAYRANGE, "range");
+		newattr(fld, DW_AT_upper_bound, DW_CLS_CONSTANT, decodetype_arraylen(gotype), 0);
+		newrefattr(fld, DW_AT_type, find_or_diag(&dwtypes, "uintptr"));
+		break;
+
+	case KindChan:
+		die = newdie(&dwtypes, DW_ABRV_CHANTYPE, name);
+		newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, bytesize, 0);
+		s = decodetype_chanelem(gotype);
+		newrefattr(die, DW_AT_internal_elem_type, defgotype(s));
+		break;
+
+	case KindFunc:
+		die = newdie(&dwtypes, DW_ABRV_FUNCTYPE, name);
+		newrefattr(die, DW_AT_type, find_or_diag(&dwtypes, "void"));
+		nfields = decodetype_funcincount(gotype);
+		for (i = 0; i < nfields; i++) {
+			s = decodetype_funcintype(gotype, i);
+			fld = newdie(die, DW_ABRV_FUNCTYPEPARAM, s->name+5);
+			newrefattr(fld, DW_AT_type, defgotype(s));
+		}
+		if (decodetype_funcdotdotdot(gotype))
+			newdie(die, DW_ABRV_DOTDOTDOT, "...");
+		nfields = decodetype_funcoutcount(gotype);
+		for (i = 0; i < nfields; i++) {
+			s = decodetype_funcouttype(gotype, i);
+			fld = newdie(die, DW_ABRV_FUNCTYPEPARAM, s->name+5);
+			newrefattr(fld, DW_AT_type, defptrto(defgotype(s)));
+		}
+		die = defptrto(die);
+		break;
+
+	case KindInterface:
+		die = newdie(&dwtypes, DW_ABRV_IFACETYPE, name);
+		newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, bytesize, 0);
+		nfields = decodetype_ifacemethodcount(gotype);
+		if (nfields == 0)
+			s = lookup("type.runtime.eface", 0);
+		else
+			s = lookup("type.runtime.iface", 0);
+		newrefattr(die, DW_AT_type, defgotype(s));
+		break;
+
+	case KindMap:
+		die = newdie(&dwtypes, DW_ABRV_MAPTYPE, name);
+		s = decodetype_mapkey(gotype);
+		newrefattr(die, DW_AT_internal_key_type, defgotype(s));
+		s = decodetype_mapvalue(gotype);
+		newrefattr(die, DW_AT_internal_val_type, defgotype(s));
+		break;
+
+	case KindPtr:
+		die = newdie(&dwtypes, DW_ABRV_PTRTYPE, name);
+		s = decodetype_ptrelem(gotype);
+		newrefattr(die, DW_AT_type, defgotype(s));
+		break;
+
+	case KindSlice:
+		die = newdie(&dwtypes, DW_ABRV_SLICETYPE, name);
+		newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, bytesize, 0);
+		s = decodetype_arrayelem(gotype);
+		newrefattr(die, DW_AT_internal_elem_type, defgotype(s));
+		break;
+
+	case KindString:
+		die = newdie(&dwtypes, DW_ABRV_STRINGTYPE, name);
+		newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, bytesize, 0);
+		break;
+
+	case KindStruct:
+		die = newdie(&dwtypes, DW_ABRV_STRUCTTYPE, name);
+		newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, bytesize, 0);
+		nfields = decodetype_structfieldcount(gotype);
+		for (i = 0; i < nfields; i++) {
+			f = decodetype_structfieldname(gotype, i);
+			s = decodetype_structfieldtype(gotype, i);
+			if (f == nil)
+				f = s->name + 5;	 // skip "type."
+			fld = newdie(die, DW_ABRV_STRUCTFIELD, f);
+			newrefattr(fld, DW_AT_type, defgotype(s));
+			newmemberoffsetattr(fld, decodetype_structfieldoffs(gotype, i));
+		}
+		break;
+
+	case KindUnsafePointer:
+		die = newdie(&dwtypes, DW_ABRV_PTRTYPE, name);
+		newrefattr(die, DW_AT_type, find(&dwtypes, "void"));
+		break;
+
+	default:
+		diag("definition of unknown kind %d: %s", kind, gotype->name);
+		die = newdie(&dwtypes, DW_ABRV_TYPEDECL, name);
+		newrefattr(die, DW_AT_type, find_or_diag(&dwtypes, "<unspecified>"));
+	 }
+
+	return die;
+}
+
+// Find or construct *T given T.
+static DWDie*
+defptrto(DWDie *dwtype)
+{
+	char ptrname[1024];
+	DWDie *die;
+
+	snprint(ptrname, sizeof ptrname, "*%s", getattr(dwtype, DW_AT_name)->data);
+	die = find(&dwtypes, ptrname);
+	if (die == nil) {
+		die = newdie(&dwtypes, DW_ABRV_PTRTYPE,
+			     strcpy(mal(strlen(ptrname)+1), ptrname));
+		newrefattr(die, DW_AT_type, dwtype);
+	}
+	return die;
+}
+
+// Copies src's children into dst. Copies attributes by value.
+// DWAttr.data is copied as pointer only.
+static void
+copychildren(DWDie *dst, DWDie *src)
+{
+	DWDie *c;
+	DWAttr *a;
+
+	for (src = src->child; src != nil; src = src->link) {
+		c = newdie(dst, src->abbrev, getattr(src, DW_AT_name)->data);
+		for (a = src->attr; a != nil; a = a->link)
+			newattr(c, a->atr, a->cls, a->value, a->data);
+		copychildren(c, src);
+	}
+	reverselist(&dst->child);
+}
+
+// Search children (assumed to have DW_TAG_member) for the one named
+// field and set it's DW_AT_type to dwtype
+static void
+substitutetype(DWDie *structdie, char *field, DWDie* dwtype)
+{
+	DWDie *child;
+	DWAttr *a;
+
+	child = find_or_diag(structdie, field);
+	if (child == nil)
+		return;
+
+	a = getattr(child, DW_AT_type);
+	if (a != nil)
+		a->data = (char*) dwtype;
+	else
+		newrefattr(child, DW_AT_type, dwtype);
+}
+
+static void
+synthesizestringtypes(DWDie* die)
+{
+	DWDie *prototype;
+
+	prototype = defgotype(lookup("type.runtime.string_", 0));
+	if (prototype == nil)
+		return;
+
+	for (; die != nil; die = die->link) {
+		if (die->abbrev != DW_ABRV_STRINGTYPE)
+			continue;
+		copychildren(die, prototype);
+	}
+}
+
+static void
+synthesizeslicetypes(DWDie *die)
+{
+	DWDie *prototype, *elem;
+
+	prototype = defgotype(lookup("type.runtime.slice",0));
+	if (prototype == nil)
+		return;
+
+	for (; die != nil; die = die->link) {
+		if (die->abbrev != DW_ABRV_SLICETYPE)
+			continue;
+		copychildren(die, prototype);
+		elem = (DWDie*) getattr(die, DW_AT_internal_elem_type)->data;
+		substitutetype(die, "array", defptrto(elem));
+	}
+}
+
+static char*
+mkinternaltypename(char *base, char *arg1, char *arg2)
+{
+	char buf[1024];
+	char *n;
+
+	if (arg2 == nil)
+		snprint(buf, sizeof buf, "%s<%s>", base, arg1);
+	else
+		snprint(buf, sizeof buf, "%s<%s,%s>", base, arg1, arg2);
+	n = mal(strlen(buf) + 1);
+	memmove(n, buf, strlen(buf));
+	return n;
+}
+
+
+// synthesizemaptypes is way too closely married to runtime/hashmap.c
+enum {
+	MaxValsize = 256 - 64
+};
+
+static void
+synthesizemaptypes(DWDie *die)
+{
+
+	DWDie *hash, *hash_subtable, *hash_entry,
+		*dwh, *dwhs, *dwhe, *keytype, *valtype, *fld;
+	int hashsize, keysize, valsize, datsize, valsize_in_hash, datavo;
+	DWAttr *a;
+
+	hash		= defgotype(lookup("type.runtime.hash",0));
+	hash_subtable	= defgotype(lookup("type.runtime.hash_subtable",0));
+	hash_entry	= defgotype(lookup("type.runtime.hash_entry",0));
+
+	if (hash == nil || hash_subtable == nil || hash_entry == nil)
+		return;
+
+	dwh = (DWDie*)getattr(find_or_diag(hash_entry, "hash"), DW_AT_type)->data;
+	if (dwh == nil)
+		return;
+
+	hashsize = getattr(dwh, DW_AT_byte_size)->value;
+
+	for (; die != nil; die = die->link) {
+		if (die->abbrev != DW_ABRV_MAPTYPE)
+			continue;
+
+		keytype = (DWDie*) getattr(die, DW_AT_internal_key_type)->data;
+		valtype = (DWDie*) getattr(die, DW_AT_internal_val_type)->data;
+
+		a = getattr(keytype, DW_AT_byte_size);
+		keysize = a ? a->value : PtrSize;  // We don't store size with Pointers
+
+		a = getattr(valtype, DW_AT_byte_size);
+		valsize = a ? a->value : PtrSize;
+
+		// This is what happens in hash_init and makemap_c
+		valsize_in_hash = valsize;
+		if (valsize > MaxValsize)
+			valsize_in_hash = PtrSize;
+		datavo = keysize;
+		if (valsize_in_hash >= PtrSize)
+			datavo = rnd(keysize, PtrSize);
+		datsize = datavo + valsize_in_hash;
+		if (datsize < PtrSize)
+			datsize = PtrSize;
+		datsize = rnd(datsize, PtrSize);
+
+		// Construct struct hash_entry<K,V>
+		dwhe = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
+			mkinternaltypename("hash_entry",
+				getattr(keytype, DW_AT_name)->data,
+				getattr(valtype, DW_AT_name)->data));
+		copychildren(dwhe, hash_entry);
+		substitutetype(dwhe, "key", keytype);
+		if (valsize > MaxValsize)
+			valtype = defptrto(valtype);
+		substitutetype(dwhe, "val", valtype);
+		fld = find_or_diag(dwhe, "val");
+		delattr(fld, DW_AT_data_member_location);
+		newmemberoffsetattr(fld, hashsize + datavo);
+		newattr(dwhe, DW_AT_byte_size, DW_CLS_CONSTANT, hashsize + datsize, NULL);
+
+		// Construct hash_subtable<hash_entry<K,V>>
+		dwhs = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
+			mkinternaltypename("hash_subtable",
+				getattr(keytype, DW_AT_name)->data,
+				getattr(valtype, DW_AT_name)->data));
+		copychildren(dwhs, hash_subtable);
+		substitutetype(dwhs, "end", defptrto(dwhe));
+		substitutetype(dwhs, "entry", dwhe);  // todo: []hash_entry with dynamic size
+		newattr(dwhs, DW_AT_byte_size, DW_CLS_CONSTANT,
+			getattr(hash_subtable, DW_AT_byte_size)->value, NULL);
+
+		// Construct hash<K,V>
+		dwh = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
+			mkinternaltypename("hash",
+				getattr(keytype, DW_AT_name)->data,
+				getattr(valtype, DW_AT_name)->data));
+		copychildren(dwh, hash);
+		substitutetype(dwh, "st", defptrto(dwhs));
+		newattr(dwh, DW_AT_byte_size, DW_CLS_CONSTANT,
+			getattr(hash, DW_AT_byte_size)->value, NULL);
+
+		newrefattr(die, DW_AT_type, defptrto(dwh));
+	}
+}
+
+static void
+synthesizechantypes(DWDie *die)
+{
+	DWDie *sudog, *waitq, *link, *hchan,
+		*dws, *dww, *dwl, *dwh, *elemtype;
+	DWAttr *a;
+	int elemsize, linksize, sudogsize;
+
+	sudog = defgotype(lookup("type.runtime.sudoG",0));
+	waitq = defgotype(lookup("type.runtime.waitQ",0));
+	link  = defgotype(lookup("type.runtime.link",0));
+	hchan = defgotype(lookup("type.runtime.hChan",0));
+	if (sudog == nil || waitq == nil || link == nil || hchan == nil)
+		return;
+
+	sudogsize = getattr(sudog, DW_AT_byte_size)->value;
+	linksize = getattr(link, DW_AT_byte_size)->value;
+
+	for (; die != nil; die = die->link) {
+		if (die->abbrev != DW_ABRV_CHANTYPE)
+			continue;
+		elemtype = (DWDie*) getattr(die, DW_AT_internal_elem_type)->data;
+		a = getattr(elemtype, DW_AT_byte_size);
+		elemsize = a ? a->value : PtrSize;
+
+		// sudog<T>
+		dws = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
+			mkinternaltypename("sudog",
+				getattr(elemtype, DW_AT_name)->data, NULL));
+		copychildren(dws, sudog);
+		substitutetype(dws, "elem", elemtype);
+		newattr(dws, DW_AT_byte_size, DW_CLS_CONSTANT,
+			sudogsize + (elemsize > 8 ? elemsize - 8 : 0), NULL);
+
+		// waitq<T>
+		dww = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
+			mkinternaltypename("waitq", getattr(elemtype, DW_AT_name)->data, NULL));
+		copychildren(dww, waitq);
+		substitutetype(dww, "first", defptrto(dws));
+		substitutetype(dww, "last",  defptrto(dws));
+		newattr(dww, DW_AT_byte_size, DW_CLS_CONSTANT,
+			getattr(waitq, DW_AT_byte_size)->value, NULL);
+
+		// link<T>
+		dwl = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
+			mkinternaltypename("link", getattr(elemtype, DW_AT_name)->data, NULL));
+		copychildren(dwl, link);
+		substitutetype(dwl, "link", defptrto(dwl));
+		substitutetype(dwl, "elem", elemtype);
+		newattr(dwl, DW_AT_byte_size, DW_CLS_CONSTANT,
+			linksize + (elemsize > 8 ? elemsize - 8 : 0), NULL);
+
+		// hchan<T>
+		dwh = newdie(&dwtypes, DW_ABRV_STRUCTTYPE,
+			mkinternaltypename("hchan", getattr(elemtype, DW_AT_name)->data, NULL));
+		copychildren(dwh, hchan);
+		substitutetype(dwh, "senddataq", defptrto(dwl));
+		substitutetype(dwh, "recvdataq", defptrto(dwl));
+		substitutetype(dwh, "recvq", dww);
+		substitutetype(dwh, "sendq", dww);
+		substitutetype(dwh, "free", dws);
+		newattr(dwh, DW_AT_byte_size, DW_CLS_CONSTANT,
+			getattr(hchan, DW_AT_byte_size)->value, NULL);
+
+		newrefattr(die, DW_AT_type, defptrto(dwh));
+	}
+}
+
+// For use with pass.c::genasmsym
+static void
+defdwsymb(Sym* sym, char *s, int t, vlong v, vlong size, int ver, Sym *gotype)
+{
+	DWDie *dv, *dt;
+
+	if (strncmp(s, "go.string.", 10) == 0)
+		return;
+	if (strncmp(s, "string.", 7) == 0)
+		return;
+	if (strncmp(s, "type._.", 7) == 0)
+		return;
+
+	if (strncmp(s, "type.", 5) == 0) {
+		defgotype(sym);
+		return;
+	}
+
+	dv = nil;
+
+	switch (t) {
+	default:
+		return;
+	case 'd':
+	case 'b':
+	case 'D':
+	case 'B':
+		dv = newdie(&dwglobals, DW_ABRV_VARIABLE, s);
+		newabslocexprattr(dv, v);
+		if (ver == 0)
+			newattr(dv, DW_AT_external, DW_CLS_FLAG, 1, 0);
+		// fallthrough
+	case 'a':
+	case 'p':
+		dt = defgotype(gotype);
+	}
+
+	if (dv != nil)
+		newrefattr(dv, DW_AT_type, dt);
+}
+
+// TODO(lvd) For now, just append them all to the first compilation
+// unit (that should be main), in the future distribute them to the
+// appropriate compilation units.
+static void
+movetomodule(DWDie *parent)
+{
+	DWDie *die;
+
+	for (die = dwroot.child->child; die->link != nil; die = die->link) /* nix */;
+	die->link = parent->child;
+}
+
+/*
+ * Filename fragments for the line history stack.
+ */
+
+static char **ftab;
+static int ftabsize;
+
+void
+dwarfaddfrag(int n, char *frag)
+{
+	int s;
+
+	if (n >= ftabsize) {
+		s = ftabsize;
+		ftabsize = 1 + n + (n >> 2);
+		ftab = realloc(ftab, ftabsize * sizeof(ftab[0]));
+		memset(ftab + s, 0, (ftabsize - s) * sizeof(ftab[0]));
+	}
+
+	if (*frag == '<')
+		frag++;
+	ftab[n] = frag;
+}
+
+// Returns a malloc'ed string, piecewise copied from the ftab.
+static char *
+decodez(char *s)
+{
+	int len, o;
+	char *ss, *f;
+	char *r, *rb, *re;
+
+	len = 0;
+	ss = s + 1;	// first is 0
+	while((o = ((uint8)ss[0] << 8) | (uint8)ss[1]) != 0) {
+		if (o < 0 || o >= ftabsize) {
+			diag("corrupt z entry");
+			return 0;
+		}
+		f = ftab[o];
+		if (f == nil) {
+			diag("corrupt z entry");
+			return 0;
+		}
+		len += strlen(f) + 1;	// for the '/'
+		ss += 2;
+	}
+
+	if (len == 0)
+		return 0;
+
+	r = malloc(len + 1);
+	rb = r;
+	re = rb + len + 1;
+
+	s++;
+	while((o = ((uint8)s[0] << 8) | (uint8)s[1]) != 0) {
+		f = ftab[o];
+		if (rb == r || rb[-1] == '/')
+			rb = seprint(rb, re, "%s", f);
+		else
+			rb = seprint(rb, re, "/%s", f);
+		s += 2;
+	}
+	return r;
+}
+
+/*
+ * The line history itself
+ */
+
+static char **histfile;	   // [0] holds "<eof>", DW_LNS_set_file arguments must be > 0.
+static int  histfilesize;
+static int  histfilecap;
+
+static void
+clearhistfile(void)
+{
+	int i;
+
+	// [0] holds "<eof>"
+	for (i = 1; i < histfilesize; i++)
+		free(histfile[i]);
+	histfilesize = 0;
+}
+
+static int
+addhistfile(char *zentry)
+{
+	char *fname;
+
+	if (histfilesize == histfilecap) {
+		histfilecap = 2 * histfilecap + 2;
+		histfile = realloc(histfile, histfilecap * sizeof(char*));
+	}
+	if (histfilesize == 0)
+		histfile[histfilesize++] = "<eof>";
+
+	fname = decodez(zentry);
+	if (fname == 0)
+		return -1;
+	// Don't fill with duplicates (check only top one).
+	if (strcmp(fname, histfile[histfilesize-1]) == 0) {
+		free(fname);
+		return histfilesize - 1;
+	}
+	histfile[histfilesize++] = fname;
+	return histfilesize - 1;
+}
+
+// if the histfile stack contains ..../runtime/runtime_defs.go
+// use that to set gdbscript
+static void
+finddebugruntimepath()
+{
+	int i, l;
+	char *c;
+
+	for (i = 1; i < histfilesize; i++) {
+		if ((c = strstr(histfile[i], "runtime/runtime_defs.go")) != nil) {
+			l = c - histfile[i];
+			memmove(gdbscript, histfile[i], l);
+			memmove(gdbscript + l, "runtime/runtime-gdb.py", strlen("runtime/runtime-gdb.py") + 1);
+			break;
+		}
+	}
+}
+
+// Go's runtime C sources are sane, and Go sources nest only 1 level,
+// so 16 should be plenty.
+static struct {
+	int file;
+	vlong line;
+} includestack[16];
+static int includetop;
+static vlong absline;
+
+typedef struct Linehist Linehist;
+struct Linehist {
+	Linehist *link;
+	vlong absline;
+	vlong line;
+	int file;
+};
+
+static Linehist *linehist;
+
+static void
+checknesting(void)
+{
+	int i;
+
+	if (includetop < 0) {
+		diag("corrupt z stack");
+		errorexit();
+	}
+	if (includetop >= nelem(includestack)) {
+		diag("nesting too deep");
+		for (i = 0; i < nelem(includestack); i++)
+			diag("\t%s", histfile[includestack[i].file]);
+		errorexit();
+	}
+}
+
+/*
+ * Return false if the a->link chain contains no history, otherwise
+ * returns true and finds z and Z entries in the Auto list (of a
+ * Prog), and resets the history stack
+ */
+static int
+inithist(Auto *a)
+{
+	Linehist *lh;
+
+	for (; a; a = a->link)
+		if (a->type == D_FILE)
+			break;
+	if (a==nil)
+		return 0;
+
+	// We have a new history.  They are guaranteed to come completely
+	// at the beginning of the compilation unit.
+	if (a->aoffset != 1) {
+		diag("stray 'z' with offset %d", a->aoffset);
+		return 0;
+	}
+
+	// Clear the history.
+	clearhistfile();
+	includetop = 0;
+	includestack[includetop].file = 0;
+	includestack[includetop].line = -1;
+	absline = 0;
+	while (linehist != nil) {
+		lh = linehist->link;
+		free(linehist);
+		linehist = lh;
+	}
+
+	// Construct the new one.
+	for (; a; a = a->link) {
+		if (a->type == D_FILE) {  // 'z'
+			int f = addhistfile(a->asym->name);
+			if (f < 0) {	   // pop file
+				includetop--;
+				checknesting();
+			} else if(f != includestack[includetop].file) { // pushed a new file
+				includestack[includetop].line += a->aoffset - absline;
+				includetop++;
+				checknesting();
+				includestack[includetop].file = f;
+				includestack[includetop].line = 1;
+			}
+			absline = a->aoffset;
+		} else if (a->type == D_FILE1) {  // 'Z'
+			// We could just fixup the current
+			// linehist->line, but there doesn't appear to
+			// be a guarantee that every 'Z' is preceded
+			// by it's own 'z', so do the safe thing and
+			// update the stack and push a new Linehist
+			// entry
+			includestack[includetop].line =	 a->aoffset;
+		} else
+			continue;
+		if (linehist == 0 || linehist->absline != absline) {
+			Linehist* lh = malloc(sizeof *lh);
+			lh->link = linehist;
+			lh->absline = absline;
+			linehist = lh;
+		}
+		linehist->file = includestack[includetop].file;
+		linehist->line = includestack[includetop].line;
+	}
+	return 1;
+}
+
+static Linehist *
+searchhist(vlong absline)
+{
+	Linehist *lh;
+
+	for (lh = linehist; lh; lh = lh->link)
+		if (lh->absline <= absline)
+			break;
+	return lh;
+}
+
+static int
+guesslang(char *s)
+{
+	if(strlen(s) >= 3 && strcmp(s+strlen(s)-3, ".go") == 0)
+		return DW_LANG_Go;
+
+	return DW_LANG_C;
+}
+
+/*
+ * Generate short opcodes when possible, long ones when neccesary.
+ * See section 6.2.5
+ */
+
+enum {
+	LINE_BASE = -1,
+	LINE_RANGE = 4,
+	OPCODE_BASE = 5
+};
+
+static void
+putpclcdelta(vlong delta_pc, vlong delta_lc)
+{
+	if (LINE_BASE <= delta_lc && delta_lc < LINE_BASE+LINE_RANGE) {
+		vlong opcode = OPCODE_BASE + (delta_lc - LINE_BASE) + (LINE_RANGE * delta_pc);
+		if (OPCODE_BASE <= opcode && opcode < 256) {
+			cput(opcode);
+			return;
+		}
+	}
+
+	if (delta_pc) {
+		cput(DW_LNS_advance_pc);
+		sleb128put(delta_pc);
+	}
+
+	cput(DW_LNS_advance_line);
+	sleb128put(delta_lc);
+	cput(DW_LNS_copy);
+}
+
+static void
+newcfaoffsetattr(DWDie *die, int32 offs)
+{
+	char block[10];
+	int i;
+
+	i = 0;
+
+	block[i++] = DW_OP_call_frame_cfa;
+	if (offs != 0) {
+		block[i++] = DW_OP_consts;
+		i += sleb128enc(offs, block+i);
+		block[i++] = DW_OP_plus;
+	}
+	newattr(die, DW_AT_location, DW_CLS_BLOCK, i, mal(i));
+	memmove(die->attr->data, block, i);
+}
+
+static char*
+mkvarname(char* name, int da)
+{
+	char buf[1024];
+	char *n;
+
+	snprint(buf, sizeof buf, "%s#%d", name, da);
+	n = mal(strlen(buf) + 1);
+	memmove(n, buf, strlen(buf));
+	return n;
+}
+
+/*
+ * Walk prog table, emit line program and build DIE tree.
+ */
+
+// flush previous compilation unit.
+static void
+flushunit(DWDie *dwinfo, vlong pc, vlong unitstart)
+{
+	vlong here;
+
+	if (dwinfo != nil && pc != 0) {
+		newattr(dwinfo, DW_AT_high_pc, DW_CLS_ADDRESS, pc+1, 0);
+	}
+
+	if (unitstart >= 0) {
+		cput(0);  // start extended opcode
+		uleb128put(1);
+		cput(DW_LNE_end_sequence);
+		cflush();
+
+		here = cpos();
+		seek(cout, unitstart, 0);
+		LPUT(here - unitstart - sizeof(int32));
+		cflush();
+		seek(cout, here, 0);
+	}
+}
+
+static void
+writelines(void)
+{
+	Prog *q;
+	Sym *s;
+	Auto *a;
+	vlong unitstart, offs;
+	vlong pc, epc, lc, llc, lline;
+	int currfile;
+	int i, lang, da, dt;
+	Linehist *lh;
+	DWDie *dwinfo, *dwfunc, *dwvar, **dws;
+	DWDie *varhash[HASHSIZE];
+	char *n, *nn;
+
+	unitstart = -1;
+	epc = pc = 0;
+	lc = 1;
+	llc = 1;
+	currfile = -1;
+	lineo = cpos();
+	dwinfo = nil;
+
+	for(cursym = textp; cursym != nil; cursym = cursym->next) {
+		s = cursym;
+		if(s->text == P)
+			continue;
+
+		// Look for history stack.  If we find one,
+		// we're entering a new compilation unit
+
+		if (inithist(s->autom)) {
+			flushunit(dwinfo, epc, unitstart);
+			unitstart = cpos();
+
+			if(debug['v'] > 1) {
+				print("dwarf writelines found %s\n", histfile[1]);
+				Linehist* lh;
+				for (lh = linehist; lh; lh = lh->link)
+					print("\t%8lld: [%4lld]%s\n",
+					      lh->absline, lh->line, histfile[lh->file]);
+			}
+
+			lang = guesslang(histfile[1]);
+			finddebugruntimepath();
+
+			dwinfo = newdie(&dwroot, DW_ABRV_COMPUNIT, strdup(histfile[1]));
+			newattr(dwinfo, DW_AT_language, DW_CLS_CONSTANT,lang, 0);
+			newattr(dwinfo, DW_AT_stmt_list, DW_CLS_PTR, unitstart - lineo, 0);
+			newattr(dwinfo, DW_AT_low_pc, DW_CLS_ADDRESS, s->text->pc, 0);
+
+			// Write .debug_line Line Number Program Header (sec 6.2.4)
+			// Fields marked with (*) must be changed for 64-bit dwarf
+			LPUT(0);   // unit_length (*), will be filled in later.
+			WPUT(3);   // dwarf version (appendix F)
+			LPUT(11);  // header_length (*), starting here.
+
+			cput(1);   // minimum_instruction_length
+			cput(1);   // default_is_stmt
+			cput(LINE_BASE);     // line_base
+			cput(LINE_RANGE);    // line_range
+			cput(OPCODE_BASE);   // opcode_base (we only use 1..4)
+			cput(0);   // standard_opcode_lengths[1]
+			cput(1);   // standard_opcode_lengths[2]
+			cput(1);   // standard_opcode_lengths[3]
+			cput(1);   // standard_opcode_lengths[4]
+			cput(0);   // include_directories  (empty)
+			cput(0);   // file_names (empty) (emitted by DW_LNE's below)
+			// header_length ends here.
+
+			for (i=1; i < histfilesize; i++) {
+				cput(0);  // start extended opcode
+				uleb128put(1 + strlen(histfile[i]) + 4);
+				cput(DW_LNE_define_file);
+				strnput(histfile[i], strlen(histfile[i]) + 4);
+				// 4 zeros: the string termination + 3 fields.
+			}
+
+			epc = pc = s->text->pc;
+			currfile = 1;
+			lc = 1;
+			llc = 1;
+
+			cput(0);  // start extended opcode
+			uleb128put(1 + PtrSize);
+			cput(DW_LNE_set_address);
+			addrput(pc);
+		}
+		if(s->text == nil)
+			continue;
+
+		if (unitstart < 0) {
+			diag("reachable code before seeing any history: %P", s->text);
+			continue;
+		}
+
+		dwfunc = newdie(dwinfo, DW_ABRV_FUNCTION, s->name);
+		newattr(dwfunc, DW_AT_low_pc, DW_CLS_ADDRESS, s->value, 0);
+		epc = s->value + s->size;
+		newattr(dwfunc, DW_AT_high_pc, DW_CLS_ADDRESS, epc, 0);
+		if (s->version == 0)
+			newattr(dwfunc, DW_AT_external, DW_CLS_FLAG, 1, 0);
+
+		if(s->text->link == nil)
+			continue;
+
+		for(q = s->text; q != P; q = q->link) {
+			lh = searchhist(q->line);
+			if (lh == nil) {
+				diag("corrupt history or bad absolute line: %P", q);
+				continue;
+			}
+
+			if (lh->file < 1) {  // 0 is the past-EOF entry.
+				// diag("instruction with line number past EOF in %s: %P", histfile[1], q);
+				continue;
+			}
+
+			lline = lh->line + q->line - lh->absline;
+			if (debug['v'] > 1)
+				print("%6llux %s[%lld] %P\n", (vlong)q->pc, histfile[lh->file], lline, q);
+
+			if (q->line == lc)
+				continue;
+			if (currfile != lh->file) {
+				currfile = lh->file;
+				cput(DW_LNS_set_file);
+				uleb128put(currfile);
+			}
+			putpclcdelta(q->pc - pc, lline - llc);
+			pc  = q->pc;
+			lc  = q->line;
+			llc = lline;
+		}
+
+		da = 0;
+		dwfunc->hash = varhash;	 // enable indexing of children by name
+		memset(varhash, 0, sizeof varhash);
+		for(a = s->autom; a; a = a->link) {
+			switch (a->type) {
+			case D_AUTO:
+				dt = DW_ABRV_AUTO;
+				offs = a->aoffset - PtrSize;
+				break;
+			case D_PARAM:
+				dt = DW_ABRV_PARAM;
+				offs = a->aoffset;
+				break;
+			default:
+				continue;
+			}
+			if (strstr(a->asym->name, ".autotmp_"))
+				continue;
+			if (find(dwfunc, a->asym->name) != nil)
+				n = mkvarname(a->asym->name, da);
+			else
+				n = a->asym->name;
+			// Drop the package prefix from locals and arguments.
+			nn = strrchr(n, '.');
+			if (nn)
+				n = nn + 1;
+
+			dwvar = newdie(dwfunc, dt, n);
+			newcfaoffsetattr(dwvar, offs);
+			newrefattr(dwvar, DW_AT_type, defgotype(a->gotype));
+
+			// push dwvar down dwfunc->child to preserve order
+			newattr(dwvar, DW_AT_internal_location, DW_CLS_CONSTANT, offs, NULL);
+			dwfunc->child = dwvar->link;  // take dwvar out from the top of the list
+			for (dws = &dwfunc->child; *dws != nil; dws = &(*dws)->link)
+				if (offs > getattr(*dws, DW_AT_internal_location)->value)
+					break;
+			dwvar->link = *dws;
+			*dws = dwvar;
+
+			da++;
+		}
+
+		dwfunc->hash = nil;
+	}
+
+	flushunit(dwinfo, epc, unitstart);
+	linesize = cpos() - lineo;
+}
+
+/*
+ *  Emit .debug_frame
+ */
+enum
+{
+	CIERESERVE = 16,
+	DATAALIGNMENTFACTOR = -4,	// TODO -PtrSize?
+	FAKERETURNCOLUMN = 16		// TODO gdb6 doesnt like > 15?
+};
+
+static void
+putpccfadelta(vlong deltapc, vlong cfa)
+{
+	if (deltapc < 0x40) {
+		cput(DW_CFA_advance_loc + deltapc);
+	} else if (deltapc < 0x100) {
+		cput(DW_CFA_advance_loc1);
+		cput(deltapc);
+	} else if (deltapc < 0x10000) {
+		cput(DW_CFA_advance_loc2);
+		WPUT(deltapc);
+	} else {
+		cput(DW_CFA_advance_loc4);
+		LPUT(deltapc);
+	}
+
+	cput(DW_CFA_def_cfa_offset_sf);
+	sleb128put(cfa / DATAALIGNMENTFACTOR);
+}
+
+static void
+writeframes(void)
+{
+	Prog *p, *q;
+	Sym *s;
+	vlong fdeo, fdesize, pad, cfa, pc;
+
+	frameo = cpos();
+
+	// Emit the CIE, Section 6.4.1
+	LPUT(CIERESERVE);	// initial length, must be multiple of PtrSize
+	LPUT(0xffffffff);	// cid.
+	cput(3);		// dwarf version (appendix F)
+	cput(0);		// augmentation ""
+	uleb128put(1);		// code_alignment_factor
+	sleb128put(DATAALIGNMENTFACTOR); // guess
+	uleb128put(FAKERETURNCOLUMN);	// return_address_register
+
+	cput(DW_CFA_def_cfa);
+	uleb128put(DWARFREGSP);	// register SP (**ABI-dependent, defined in l.h)
+	uleb128put(PtrSize);	// offset
+
+	cput(DW_CFA_offset + FAKERETURNCOLUMN);	 // return address
+	uleb128put(-PtrSize / DATAALIGNMENTFACTOR);  // at cfa - x*4
+
+	// 4 is to exclude the length field.
+	pad = CIERESERVE + frameo + 4 - cpos();
+	if (pad < 0) {
+		diag("CIERESERVE too small by %lld bytes.", -pad);
+		errorexit();
+	}
+	strnput("", pad);
+
+	for(cursym = textp; cursym != nil; cursym = cursym->next) {
+		s = cursym;
+		if(s->text == nil)
+			continue;
+
+		fdeo = cpos();
+		// Emit a FDE, Section 6.4.1, starting wit a placeholder.
+		LPUT(0);	// length, must be multiple of PtrSize
+		LPUT(0);	// Pointer to the CIE above, at offset 0
+		addrput(0);	// initial location
+		addrput(0);	// address range
+
+		cfa = PtrSize;	// CFA starts at sp+PtrSize
+		p = s->text;
+		pc = p->pc;
+
+		for(q = p; q->link != P; q = q->link) {
+			if (q->spadj == 0)
+				continue;
+			cfa += q->spadj;
+			putpccfadelta(q->link->pc - pc, cfa);
+			pc = q->link->pc;
+		}
+
+		fdesize = cpos() - fdeo - 4;	// exclude the length field.
+		pad = rnd(fdesize, PtrSize) - fdesize;
+		strnput("", pad);
+		fdesize += pad;
+		cflush();
+
+		// Emit the FDE header for real, Section 6.4.1.
+		seek(cout, fdeo, 0);
+		LPUT(fdesize);
+		LPUT(0);
+		addrput(p->pc);
+		addrput(s->size);
+
+		cflush();
+		seek(cout, fdeo + 4 + fdesize, 0);
+	}
+
+	cflush();
+	framesize = cpos() - frameo;
+}
+
+/*
+ *  Walk DWarfDebugInfoEntries, and emit .debug_info
+ */
+enum
+{
+	COMPUNITHEADERSIZE = 4+2+4+1
+};
+
+static void
+writeinfo(void)
+{
+	DWDie *compunit;
+	vlong unitstart, here;
+
+	fwdcount = 0;
+
+	for (compunit = dwroot.child; compunit; compunit = compunit->link) {
+		unitstart = cpos();
+
+		// Write .debug_info Compilation Unit Header (sec 7.5.1)
+		// Fields marked with (*) must be changed for 64-bit dwarf
+		// This must match COMPUNITHEADERSIZE above.
+		LPUT(0);	// unit_length (*), will be filled in later.
+		WPUT(3);	// dwarf version (appendix F)
+		LPUT(0);	// debug_abbrev_offset (*)
+		cput(PtrSize);	// address_size
+
+		putdie(compunit);
+
+		cflush();
+		here = cpos();
+		seek(cout, unitstart, 0);
+		LPUT(here - unitstart - 4);	// exclude the length field.
+		cflush();
+		seek(cout, here, 0);
+	}
+
+}
+
+/*
+ *  Emit .debug_pubnames/_types.  _info must have been written before,
+ *  because we need die->offs and infoo/infosize;
+ */
+static int
+ispubname(DWDie *die) {
+	DWAttr *a;
+
+	switch(die->abbrev) {
+	case DW_ABRV_FUNCTION:
+	case DW_ABRV_VARIABLE:
+		a = getattr(die, DW_AT_external);
+		return a && a->value;
+	}
+	return 0;
+}
+
+static int
+ispubtype(DWDie *die) {
+	return die->abbrev >= DW_ABRV_NULLTYPE;
+}
+
+static vlong
+writepub(int (*ispub)(DWDie*))
+{
+	DWDie *compunit, *die;
+	DWAttr *dwa;
+	vlong unitstart, unitend, sectionstart, here;
+
+	sectionstart = cpos();
+
+	for (compunit = dwroot.child; compunit != nil; compunit = compunit->link) {
+		unitstart = compunit->offs - COMPUNITHEADERSIZE;
+		if (compunit->link != nil)
+			unitend = compunit->link->offs - COMPUNITHEADERSIZE;
+		else
+			unitend = infoo + infosize;
+
+		// Write .debug_pubnames/types	Header (sec 6.1.1)
+		LPUT(0);			// unit_length (*), will be filled in later.
+		WPUT(2);			// dwarf version (appendix F)
+		LPUT(unitstart);		// debug_info_offset (of the Comp unit Header)
+		LPUT(unitend - unitstart);	// debug_info_length
+
+		for (die = compunit->child; die != nil; die = die->link) {
+			if (!ispub(die)) continue;
+			LPUT(die->offs - unitstart);
+			dwa = getattr(die, DW_AT_name);
+			strnput(dwa->data, dwa->value + 1);
+		}
+		LPUT(0);
+
+		cflush();
+		here = cpos();
+		seek(cout, sectionstart, 0);
+		LPUT(here - sectionstart - 4);	// exclude the length field.
+		cflush();
+		seek(cout, here, 0);
+
+	}
+
+	return sectionstart;
+}
+
+/*
+ *  emit .debug_aranges.  _info must have been written before,
+ *  because we need die->offs of dw_globals.
+ */
+static vlong
+writearanges(void)
+{
+	DWDie *compunit;
+	DWAttr *b, *e;
+	int headersize;
+	vlong sectionstart;
+
+	sectionstart = cpos();
+	headersize = rnd(4+2+4+1+1, PtrSize);  // don't count unit_length field itself
+
+	for (compunit = dwroot.child; compunit != nil; compunit = compunit->link) {
+		b = getattr(compunit,  DW_AT_low_pc);
+		if (b == nil)
+			continue;
+		e = getattr(compunit,  DW_AT_high_pc);
+		if (e == nil)
+			continue;
+
+		// Write .debug_aranges	 Header + entry	 (sec 6.1.2)
+		LPUT(headersize + 4*PtrSize - 4);	// unit_length (*)
+		WPUT(2);	// dwarf version (appendix F)
+		LPUT(compunit->offs - COMPUNITHEADERSIZE);	// debug_info_offset
+		cput(PtrSize);	// address_size
+		cput(0);	// segment_size
+		strnput("", headersize - (4+2+4+1+1));	// align to PtrSize
+
+		addrput(b->value);
+		addrput(e->value - b->value);
+		addrput(0);
+		addrput(0);
+	}
+	cflush();
+	return sectionstart;
+}
+
+static vlong
+writegdbscript(void)
+{
+	vlong sectionstart;
+
+	sectionstart = cpos();
+
+	if (gdbscript[0]) {
+		cput(1);  // magic 1 byte?
+		strnput(gdbscript, strlen(gdbscript)+1);
+		cflush();
+	}
+	return sectionstart;
+}
+
+/*
+ * This is the main entry point for generating dwarf.  After emitting
+ * the mandatory debug_abbrev section, it calls writelines() to set up
+ * the per-compilation unit part of the DIE tree, while simultaneously
+ * emitting the debug_line section.  When the final tree contains
+ * forward references, it will write the debug_info section in 2
+ * passes.
+ *
+ */
+void
+dwarfemitdebugsections(void)
+{
+	vlong infoe;
+	DWDie* die;
+
+	// For diagnostic messages.
+	newattr(&dwtypes, DW_AT_name, DW_CLS_STRING, strlen("dwtypes"), "dwtypes");
+
+	mkindex(&dwroot);
+	mkindex(&dwtypes);
+	mkindex(&dwglobals);
+
+	// Some types that must exist to define other ones.
+	newdie(&dwtypes, DW_ABRV_NULLTYPE, "<unspecified>");
+	newdie(&dwtypes, DW_ABRV_NULLTYPE, "void");
+	newrefattr(newdie(&dwtypes, DW_ABRV_PTRTYPE, "unsafe.Pointer"),
+		DW_AT_type, find(&dwtypes, "void"));
+	die = newdie(&dwtypes, DW_ABRV_BASETYPE, "uintptr");  // needed for array size
+	newattr(die, DW_AT_encoding,  DW_CLS_CONSTANT, DW_ATE_unsigned, 0);
+	newattr(die, DW_AT_byte_size, DW_CLS_CONSTANT, PtrSize, 0);
+
+	// Needed by the prettyprinter code for interface inspection.
+	defgotype(lookup("type.runtime.commonType",0));
+	defgotype(lookup("type.runtime.InterfaceType",0));
+	defgotype(lookup("type.runtime.itab",0));
+
+	genasmsym(defdwsymb);
+
+	writeabbrev();
+	writelines();
+	writeframes();
+
+	synthesizestringtypes(dwtypes.child);
+	synthesizeslicetypes(dwtypes.child);
+	synthesizemaptypes(dwtypes.child);
+	synthesizechantypes(dwtypes.child);
+
+	reversetree(&dwroot.child);
+	reversetree(&dwtypes.child);
+	reversetree(&dwglobals.child);
+
+	movetomodule(&dwtypes);
+	movetomodule(&dwglobals);
+
+	infoo = cpos();
+	writeinfo();
+	gdbscripto = arangeso = pubtypeso = pubnameso = infoe = cpos();
+
+	if (fwdcount > 0) {
+		if (debug['v'])
+			Bprint(&bso, "%5.2f dwarf pass 2.\n", cputime());
+		seek(cout, infoo, 0);
+		writeinfo();
+		if (fwdcount > 0) {
+			diag("unresolved references after first dwarf info pass");
+			errorexit();
+		}
+		if (infoe != cpos()) {
+			diag("inconsistent second dwarf info pass");
+			errorexit();
+		}
+	}
+	infosize = infoe - infoo;
+
+	pubnameso  = writepub(ispubname);
+	pubtypeso  = writepub(ispubtype);
+	arangeso   = writearanges();
+	gdbscripto = writegdbscript();
+
+	pubnamessize  = pubtypeso - pubnameso;
+	pubtypessize  = arangeso - pubtypeso;
+	arangessize   = gdbscripto - arangeso;
+	gdbscriptsize = cpos() - gdbscripto;
+}
+
+/*
+ *  Elf.
+ */
+enum
+{
+	ElfStrDebugAbbrev,
+	ElfStrDebugAranges,
+	ElfStrDebugFrame,
+	ElfStrDebugInfo,
+	ElfStrDebugLine,
+	ElfStrDebugLoc,
+	ElfStrDebugMacinfo,
+	ElfStrDebugPubNames,
+	ElfStrDebugPubTypes,
+	ElfStrDebugRanges,
+	ElfStrDebugStr,
+	ElfStrGDBScripts,
+	NElfStrDbg
+};
+
+vlong elfstrdbg[NElfStrDbg];
+
+void
+dwarfaddshstrings(Sym *shstrtab)
+{
+	elfstrdbg[ElfStrDebugAbbrev]   = addstring(shstrtab, ".debug_abbrev");
+	elfstrdbg[ElfStrDebugAranges]  = addstring(shstrtab, ".debug_aranges");
+	elfstrdbg[ElfStrDebugFrame]    = addstring(shstrtab, ".debug_frame");
+	elfstrdbg[ElfStrDebugInfo]     = addstring(shstrtab, ".debug_info");
+	elfstrdbg[ElfStrDebugLine]     = addstring(shstrtab, ".debug_line");
+	elfstrdbg[ElfStrDebugLoc]      = addstring(shstrtab, ".debug_loc");
+	elfstrdbg[ElfStrDebugMacinfo]  = addstring(shstrtab, ".debug_macinfo");
+	elfstrdbg[ElfStrDebugPubNames] = addstring(shstrtab, ".debug_pubnames");
+	elfstrdbg[ElfStrDebugPubTypes] = addstring(shstrtab, ".debug_pubtypes");
+	elfstrdbg[ElfStrDebugRanges]   = addstring(shstrtab, ".debug_ranges");
+	elfstrdbg[ElfStrDebugStr]      = addstring(shstrtab, ".debug_str");
+	elfstrdbg[ElfStrGDBScripts]    = addstring(shstrtab, ".debug_gdb_scripts");
+}
+
+void
+dwarfaddelfheaders(void)
+{
+	ElfShdr *sh;
+
+	sh = newElfShdr(elfstrdbg[ElfStrDebugAbbrev]);
+	sh->type = SHT_PROGBITS;
+	sh->off = abbrevo;
+	sh->size = abbrevsize;
+	sh->addralign = 1;
+
+	sh = newElfShdr(elfstrdbg[ElfStrDebugLine]);
+	sh->type = SHT_PROGBITS;
+	sh->off = lineo;
+	sh->size = linesize;
+	sh->addralign = 1;
+
+	sh = newElfShdr(elfstrdbg[ElfStrDebugFrame]);
+	sh->type = SHT_PROGBITS;
+	sh->off = frameo;
+	sh->size = framesize;
+	sh->addralign = 1;
+
+	sh = newElfShdr(elfstrdbg[ElfStrDebugInfo]);
+	sh->type = SHT_PROGBITS;
+	sh->off = infoo;
+	sh->size = infosize;
+	sh->addralign = 1;
+
+	if (pubnamessize > 0) {
+		sh = newElfShdr(elfstrdbg[ElfStrDebugPubNames]);
+		sh->type = SHT_PROGBITS;
+		sh->off = pubnameso;
+		sh->size = pubnamessize;
+		sh->addralign = 1;
+	}
+
+	if (pubtypessize > 0) {
+		sh = newElfShdr(elfstrdbg[ElfStrDebugPubTypes]);
+		sh->type = SHT_PROGBITS;
+		sh->off = pubtypeso;
+		sh->size = pubtypessize;
+		sh->addralign = 1;
+	}
+
+	if (arangessize) {
+		sh = newElfShdr(elfstrdbg[ElfStrDebugAranges]);
+		sh->type = SHT_PROGBITS;
+		sh->off = arangeso;
+		sh->size = arangessize;
+		sh->addralign = 1;
+	}
+
+	if (gdbscriptsize) {
+		sh = newElfShdr(elfstrdbg[ElfStrGDBScripts]);
+		sh->type = SHT_PROGBITS;
+		sh->off = gdbscripto;
+		sh->size = gdbscriptsize;
+		sh->addralign = 1;
+	}
+}
+
+/*
+ * Macho
+ */
+void
+dwarfaddmachoheaders(void)
+{
+	MachoSect *msect;
+	MachoSeg *ms;
+	vlong fakestart;
+	int nsect;
+
+	// Zero vsize segments won't be loaded in memory, even so they
+	// have to be page aligned in the file.
+	fakestart = abbrevo & ~0xfff;
+
+	nsect = 4;
+	if (pubnamessize  > 0)
+		nsect++;
+	if (pubtypessize  > 0)
+		nsect++;
+	if (arangessize	  > 0)
+		nsect++;
+	if (gdbscriptsize > 0)
+		nsect++;
+
+	ms = newMachoSeg("__DWARF", nsect);
+	ms->fileoffset = fakestart;
+	ms->filesize = abbrevo-fakestart;
+
+	msect = newMachoSect(ms, "__debug_abbrev");
+	msect->off = abbrevo;
+	msect->size = abbrevsize;
+	ms->filesize += msect->size;
+
+	msect = newMachoSect(ms, "__debug_line");
+	msect->off = lineo;
+	msect->size = linesize;
+	ms->filesize += msect->size;
+
+	msect = newMachoSect(ms, "__debug_frame");
+	msect->off = frameo;
+	msect->size = framesize;
+	ms->filesize += msect->size;
+
+	msect = newMachoSect(ms, "__debug_info");
+	msect->off = infoo;
+	msect->size = infosize;
+	ms->filesize += msect->size;
+
+	if (pubnamessize > 0) {
+		msect = newMachoSect(ms, "__debug_pubnames");
+		msect->off = pubnameso;
+		msect->size = pubnamessize;
+		ms->filesize += msect->size;
+	}
+
+	if (pubtypessize > 0) {
+		msect = newMachoSect(ms, "__debug_pubtypes");
+		msect->off = pubtypeso;
+		msect->size = pubtypessize;
+		ms->filesize += msect->size;
+	}
+
+	if (arangessize > 0) {
+		msect = newMachoSect(ms, "__debug_aranges");
+		msect->off = arangeso;
+		msect->size = arangessize;
+		ms->filesize += msect->size;
+	}
+
+	// TODO(lvd) fix gdb/python to load MachO (16 char section name limit)
+	if (gdbscriptsize > 0) {
+		msect = newMachoSect(ms, "__debug_gdb_scripts");
+		msect->off = gdbscripto;
+		msect->size = gdbscriptsize;
+		ms->filesize += msect->size;
+	}
+}
diff --git a/src/cmd/ld/dwarf.h b/src/cmd/ld/dwarf.h
new file mode 100644
index 000000000..7881213c2
--- /dev/null
+++ b/src/cmd/ld/dwarf.h
@@ -0,0 +1,29 @@
+// Copyright 2010 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.
+
+/*
+ * Register 'f' symbol file fragments.  Doing this while parsing the
+ * .6 input saves a pass over the symbol table later.
+ */
+void dwarfaddfrag(int n, char* frag);
+
+/*
+ * Emit debug_abbrevs, debug_info and debug_line sections to current
+ * offset in cout.
+ */
+void dwarfemitdebugsections(void);
+
+/*
+ * Add the dwarf section names to the ELF
+ * s[ection]h[eader]str[ing]tab.  Prerequisite for
+ * dwarfaddelfheaders().
+ */
+void dwarfaddshstrings(Sym *shstrtab);
+
+/*
+ * Add section headers pointing to the sections emitted in
+ * dwarfemitdebugsections.
+ */
+void dwarfaddelfheaders(void);
+void dwarfaddmachoheaders(void);
diff --git a/src/cmd/ld/dwarf_defs.h b/src/cmd/ld/dwarf_defs.h
new file mode 100644
index 000000000..eed143dff
--- /dev/null
+++ b/src/cmd/ld/dwarf_defs.h
@@ -0,0 +1,503 @@
+// Copyright 2010 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.
+
+// Cut, pasted, tr-and-awk'ed from tables in
+// http://dwarfstd.org/doc/Dwarf3.pdf
+
+// Table 18
+enum
+{
+	DW_TAG_array_type = 0x01,
+	DW_TAG_class_type = 0x02,
+	DW_TAG_entry_point = 0x03,
+	DW_TAG_enumeration_type = 0x04,
+	DW_TAG_formal_parameter = 0x05,
+	DW_TAG_imported_declaration = 0x08,
+	DW_TAG_label = 0x0a,
+	DW_TAG_lexical_block = 0x0b,
+	DW_TAG_member = 0x0d,
+	DW_TAG_pointer_type = 0x0f,
+	DW_TAG_reference_type = 0x10,
+	DW_TAG_compile_unit = 0x11,
+	DW_TAG_string_type = 0x12,
+	DW_TAG_structure_type = 0x13,
+	DW_TAG_subroutine_type = 0x15,
+	DW_TAG_typedef = 0x16,
+	DW_TAG_union_type = 0x17,
+	DW_TAG_unspecified_parameters = 0x18,
+	DW_TAG_variant = 0x19,
+	DW_TAG_common_block = 0x1a,
+	DW_TAG_common_inclusion = 0x1b,
+	DW_TAG_inheritance = 0x1c,
+	DW_TAG_inlined_subroutine = 0x1d,
+	DW_TAG_module = 0x1e,
+	DW_TAG_ptr_to_member_type = 0x1f,
+	DW_TAG_set_type = 0x20,
+	DW_TAG_subrange_type = 0x21,
+	DW_TAG_with_stmt = 0x22,
+	DW_TAG_access_declaration = 0x23,
+	DW_TAG_base_type = 0x24,
+	DW_TAG_catch_block = 0x25,
+	DW_TAG_const_type = 0x26,
+	DW_TAG_constant = 0x27,
+	DW_TAG_enumerator = 0x28,
+	DW_TAG_file_type = 0x29,
+	DW_TAG_friend = 0x2a,
+	DW_TAG_namelist = 0x2b,
+	DW_TAG_namelist_item = 0x2c,
+	DW_TAG_packed_type = 0x2d,
+	DW_TAG_subprogram = 0x2e,
+	DW_TAG_template_type_parameter = 0x2f,
+	DW_TAG_template_value_parameter = 0x30,
+	DW_TAG_thrown_type = 0x31,
+	DW_TAG_try_block = 0x32,
+	DW_TAG_variant_part = 0x33,
+	DW_TAG_variable = 0x34,
+	DW_TAG_volatile_type = 0x35,
+	// Dwarf3
+	DW_TAG_dwarf_procedure = 0x36,
+	DW_TAG_restrict_type = 0x37,
+	DW_TAG_interface_type = 0x38,
+	DW_TAG_namespace = 0x39,
+	DW_TAG_imported_module = 0x3a,
+	DW_TAG_unspecified_type = 0x3b,
+	DW_TAG_partial_unit = 0x3c,
+	DW_TAG_imported_unit = 0x3d,
+	DW_TAG_condition = 0x3f,
+	DW_TAG_shared_type = 0x40,
+	// Dwarf4
+	DW_TAG_type_unit = 0x41,
+	DW_TAG_rvalue_reference_type = 0x42,
+	DW_TAG_template_alias = 0x43,
+
+	// User defined
+	DW_TAG_lo_user = 0x4080,
+	DW_TAG_hi_user = 0xffff,
+
+};
+
+// Table 19
+enum
+{
+	DW_CHILDREN_no = 0x00,
+	DW_CHILDREN_yes = 0x01,
+};
+
+// Not from the spec, but logicaly belongs here
+enum
+{
+	DW_CLS_ADDRESS = 0x01,
+	DW_CLS_BLOCK,
+	DW_CLS_CONSTANT,
+	DW_CLS_FLAG,
+	DW_CLS_PTR,	// lineptr, loclistptr, macptr, rangelistptr
+	DW_CLS_REFERENCE,
+	DW_CLS_STRING
+};
+
+// Table 20
+enum
+{
+	DW_AT_sibling = 0x01,	// reference
+	DW_AT_location = 0x02,	// block, loclistptr
+	DW_AT_name = 0x03,	// string
+	DW_AT_ordering = 0x09,	// constant
+	DW_AT_byte_size = 0x0b,	// block, constant, reference
+	DW_AT_bit_offset = 0x0c,	// block, constant, reference
+	DW_AT_bit_size = 0x0d,	// block, constant, reference
+	DW_AT_stmt_list = 0x10,	// lineptr
+	DW_AT_low_pc = 0x11,	// address
+	DW_AT_high_pc = 0x12,	// address
+	DW_AT_language = 0x13,	// constant
+	DW_AT_discr = 0x15,	// reference
+	DW_AT_discr_value = 0x16,	// constant
+	DW_AT_visibility = 0x17,	// constant
+	DW_AT_import = 0x18,	// reference
+	DW_AT_string_length = 0x19,	// block, loclistptr
+	DW_AT_common_reference = 0x1a,	// reference
+	DW_AT_comp_dir = 0x1b,	// string
+	DW_AT_const_value = 0x1c,	// block, constant, string
+	DW_AT_containing_type = 0x1d,	// reference
+	DW_AT_default_value = 0x1e,	// reference
+	DW_AT_inline = 0x20,	// constant
+	DW_AT_is_optional = 0x21,	// flag
+	DW_AT_lower_bound = 0x22,	// block, constant, reference
+	DW_AT_producer = 0x25,	// string
+	DW_AT_prototyped = 0x27,	// flag
+	DW_AT_return_addr = 0x2a,	// block, loclistptr
+	DW_AT_start_scope = 0x2c,	// constant
+	DW_AT_bit_stride = 0x2e,	// constant
+	DW_AT_upper_bound = 0x2f,	// block, constant, reference
+	DW_AT_abstract_origin = 0x31,	// reference
+	DW_AT_accessibility = 0x32,	// constant
+	DW_AT_address_class = 0x33,	// constant
+	DW_AT_artificial = 0x34,	// flag
+	DW_AT_base_types = 0x35,	// reference
+	DW_AT_calling_convention = 0x36,	// constant
+	DW_AT_count = 0x37,	// block, constant, reference
+	DW_AT_data_member_location = 0x38,	// block, constant, loclistptr
+	DW_AT_decl_column = 0x39,	// constant
+	DW_AT_decl_file = 0x3a,	// constant
+	DW_AT_decl_line = 0x3b,	// constant
+	DW_AT_declaration = 0x3c,	// flag
+	DW_AT_discr_list = 0x3d,	// block
+	DW_AT_encoding = 0x3e,	// constant
+	DW_AT_external = 0x3f,	// flag
+	DW_AT_frame_base = 0x40,	// block, loclistptr
+	DW_AT_friend = 0x41,	// reference
+	DW_AT_identifier_case = 0x42,	// constant
+	DW_AT_macro_info = 0x43,	// macptr
+	DW_AT_namelist_item = 0x44,	// block
+	DW_AT_priority = 0x45,	// reference
+	DW_AT_segment = 0x46,	// block, loclistptr
+	DW_AT_specification = 0x47,	// reference
+	DW_AT_static_link = 0x48,	// block, loclistptr
+	DW_AT_type = 0x49,	// reference
+	DW_AT_use_location = 0x4a,	// block, loclistptr
+	DW_AT_variable_parameter = 0x4b,	// flag
+	DW_AT_virtuality = 0x4c,	// constant
+	DW_AT_vtable_elem_location = 0x4d,	// block, loclistptr
+	// Dwarf3
+	DW_AT_allocated = 0x4e,	// block, constant, reference
+	DW_AT_associated = 0x4f,	// block, constant, reference
+	DW_AT_data_location = 0x50,	// block
+	DW_AT_byte_stride = 0x51,	// block, constant, reference
+	DW_AT_entry_pc = 0x52,	// address
+	DW_AT_use_UTF8 = 0x53,	// flag
+	DW_AT_extension = 0x54,	// reference
+	DW_AT_ranges = 0x55,	// rangelistptr
+	DW_AT_trampoline = 0x56,	// address, flag, reference, string
+	DW_AT_call_column = 0x57,	// constant
+	DW_AT_call_file = 0x58,	// constant
+	DW_AT_call_line = 0x59,	// constant
+	DW_AT_description = 0x5a,	// string
+	DW_AT_binary_scale = 0x5b,	// constant
+	DW_AT_decimal_scale = 0x5c,	// constant
+	DW_AT_small = 0x5d,	// reference
+	DW_AT_decimal_sign = 0x5e,	// constant
+	DW_AT_digit_count = 0x5f,	// constant
+	DW_AT_picture_string = 0x60,	// string
+	DW_AT_mutable = 0x61,	// flag
+	DW_AT_threads_scaled = 0x62,	// flag
+	DW_AT_explicit = 0x63,	// flag
+	DW_AT_object_pointer = 0x64,	// reference
+	DW_AT_endianity = 0x65,	// constant
+	DW_AT_elemental = 0x66,	// flag
+	DW_AT_pure = 0x67,	// flag
+	DW_AT_recursive = 0x68,	// flag
+
+	DW_AT_lo_user = 0x2000,	// ---
+	DW_AT_hi_user = 0x3fff,	// ---
+
+};
+
+// Table 21
+enum
+{
+	DW_FORM_addr = 0x01,	// address
+	DW_FORM_block2 = 0x03,	// block
+	DW_FORM_block4 = 0x04,	// block
+	DW_FORM_data2 = 0x05,	// constant
+	DW_FORM_data4 = 0x06,	// constant, lineptr, loclistptr, macptr, rangelistptr
+	DW_FORM_data8 = 0x07,	// constant, lineptr, loclistptr, macptr, rangelistptr
+	DW_FORM_string = 0x08,	// string
+	DW_FORM_block = 0x09,	// block
+	DW_FORM_block1 = 0x0a,	// block
+	DW_FORM_data1 = 0x0b,	// constant
+	DW_FORM_flag = 0x0c,	// flag
+	DW_FORM_sdata = 0x0d,	// constant
+	DW_FORM_strp = 0x0e,	// string
+	DW_FORM_udata = 0x0f,	// constant
+	DW_FORM_ref_addr = 0x10,	// reference
+	DW_FORM_ref1 = 0x11,	// reference
+	DW_FORM_ref2 = 0x12,	// reference
+	DW_FORM_ref4 = 0x13,	// reference
+	DW_FORM_ref8 = 0x14,	// reference
+	DW_FORM_ref_udata = 0x15,	// reference
+	DW_FORM_indirect = 0x16,	// (see Section 7.5.3)
+};
+
+// Table 24 (#operands, notes)
+enum
+{
+	DW_OP_addr = 0x03,	// 1 constant address (size target specific)
+	DW_OP_deref = 0x06,	// 0
+	DW_OP_const1u = 0x08,	// 1 1-byte constant
+	DW_OP_const1s = 0x09,	// 1 1-byte constant
+	DW_OP_const2u = 0x0a,	// 1 2-byte constant
+	DW_OP_const2s = 0x0b,	// 1 2-byte constant
+	DW_OP_const4u = 0x0c,	// 1 4-byte constant
+	DW_OP_const4s = 0x0d,	// 1 4-byte constant
+	DW_OP_const8u = 0x0e,	// 1 8-byte constant
+	DW_OP_const8s = 0x0f,	// 1 8-byte constant
+	DW_OP_constu = 0x10,	// 1 ULEB128 constant
+	DW_OP_consts = 0x11,	// 1 SLEB128 constant
+	DW_OP_dup = 0x12,	// 0
+	DW_OP_drop = 0x13,	// 0
+	DW_OP_over = 0x14,	// 0
+	DW_OP_pick = 0x15,	// 1 1-byte stack index
+	DW_OP_swap = 0x16,	// 0
+	DW_OP_rot = 0x17,	// 0
+	DW_OP_xderef = 0x18,	// 0
+	DW_OP_abs = 0x19,	// 0
+	DW_OP_and = 0x1a,	// 0
+	DW_OP_div = 0x1b,	// 0
+	DW_OP_minus = 0x1c,	// 0
+	DW_OP_mod = 0x1d,	// 0
+	DW_OP_mul = 0x1e,	// 0
+	DW_OP_neg = 0x1f,	// 0
+	DW_OP_not = 0x20,	// 0
+	DW_OP_or = 0x21,	// 0
+	DW_OP_plus = 0x22,	// 0
+	DW_OP_plus_uconst = 0x23,	// 1 ULEB128 addend
+	DW_OP_shl = 0x24,	// 0
+	DW_OP_shr = 0x25,	// 0
+	DW_OP_shra = 0x26,	// 0
+	DW_OP_xor = 0x27,	// 0
+	DW_OP_skip = 0x2f,	// 1 signed 2-byte constant
+	DW_OP_bra = 0x28,	// 1 signed 2-byte constant
+	DW_OP_eq = 0x29,	// 0
+	DW_OP_ge = 0x2a,	// 0
+	DW_OP_gt = 0x2b,	// 0
+	DW_OP_le = 0x2c,	// 0
+	DW_OP_lt = 0x2d,	// 0
+	DW_OP_ne = 0x2e,	// 0
+	DW_OP_lit0 = 0x30,	// 0 ...
+	DW_OP_lit31 = 0x4f,	// 0 literals 0..31 = (DW_OP_lit0 +
+	// literal)
+	DW_OP_reg0 = 0x50,	// 0 ..
+	DW_OP_reg31 = 0x6f,	// 0 reg 0..31 = (DW_OP_reg0 + regnum)
+	DW_OP_breg0 = 0x70,	// 1 ...
+	DW_OP_breg31 = 0x8f,	// 1 SLEB128 offset base register 0..31 = (DW_OP_breg0 + regnum)
+	DW_OP_regx = 0x90,	// 1 ULEB128 register
+	DW_OP_fbreg = 0x91,	// 1 SLEB128 offset
+	DW_OP_bregx = 0x92,	// 2 ULEB128 register followed by SLEB128 offset
+	DW_OP_piece = 0x93,	// 1 ULEB128 size of piece addressed
+	DW_OP_deref_size = 0x94,	// 1 1-byte size of data retrieved
+	DW_OP_xderef_size = 0x95,	// 1 1-byte size of data retrieved
+	DW_OP_nop = 0x96,	// 0
+	DW_OP_push_object_address = 0x97,	// 0
+	DW_OP_call2 = 0x98,	// 1 2-byte offset of DIE
+	DW_OP_call4 = 0x99,	// 1 4-byte offset of DIE
+	DW_OP_call_ref = 0x9a,	// 1 4- or 8-byte offset of DIE
+	DW_OP_form_tls_address = 0x9b,	// 0
+	DW_OP_call_frame_cfa = 0x9c,	// 0
+	DW_OP_bit_piece = 0x9d,	// 2
+	DW_OP_lo_user = 0xe0,
+	DW_OP_hi_user = 0xff,
+};
+
+// Table 25
+enum
+{
+	DW_ATE_address = 0x01,
+	DW_ATE_boolean = 0x02,
+	DW_ATE_complex_float = 0x03,
+	DW_ATE_float = 0x04,
+	DW_ATE_signed = 0x05,
+	DW_ATE_signed_char = 0x06,
+	DW_ATE_unsigned = 0x07,
+	DW_ATE_unsigned_char = 0x08,
+	DW_ATE_imaginary_float = 0x09,
+	DW_ATE_packed_decimal = 0x0a,
+	DW_ATE_numeric_string = 0x0b,
+	DW_ATE_edited = 0x0c,
+	DW_ATE_signed_fixed = 0x0d,
+	DW_ATE_unsigned_fixed = 0x0e,
+	DW_ATE_decimal_float = 0x0f,
+	DW_ATE_lo_user = 0x80,
+	DW_ATE_hi_user = 0xff,
+};
+
+// Table 26
+enum
+{
+	DW_DS_unsigned = 0x01,
+	DW_DS_leading_overpunch = 0x02,
+	DW_DS_trailing_overpunch = 0x03,
+	DW_DS_leading_separate = 0x04,
+	DW_DS_trailing_separate = 0x05,
+};
+
+// Table 27
+enum
+{
+	DW_END_default = 0x00,
+	DW_END_big = 0x01,
+	DW_END_little = 0x02,
+	DW_END_lo_user = 0x40,
+	DW_END_hi_user = 0xff,
+};
+
+// Table 28
+enum
+{
+	DW_ACCESS_public = 0x01,
+	DW_ACCESS_protected = 0x02,
+	DW_ACCESS_private = 0x03,
+};
+
+// Table 29
+enum
+{
+	DW_VIS_local = 0x01,
+	DW_VIS_exported = 0x02,
+	DW_VIS_qualified = 0x03,
+};
+
+// Table 30
+enum
+{
+	DW_VIRTUALITY_none = 0x00,
+	DW_VIRTUALITY_virtual = 0x01,
+	DW_VIRTUALITY_pure_virtual = 0x02,
+};
+
+// Table 31
+enum
+{
+	DW_LANG_C89 = 0x0001,
+	DW_LANG_C = 0x0002,
+	DW_LANG_Ada83 = 0x0003,
+	DW_LANG_C_plus_plus = 0x0004,
+	DW_LANG_Cobol74 = 0x0005,
+	DW_LANG_Cobol85 = 0x0006,
+	DW_LANG_Fortran77 = 0x0007,
+	DW_LANG_Fortran90 = 0x0008,
+	DW_LANG_Pascal83 = 0x0009,
+	DW_LANG_Modula2 = 0x000a,
+	// Dwarf3
+	DW_LANG_Java = 0x000b,
+	DW_LANG_C99 = 0x000c,
+	DW_LANG_Ada95 = 0x000d,
+	DW_LANG_Fortran95 = 0x000e,
+	DW_LANG_PLI = 0x000f,
+	DW_LANG_ObjC = 0x0010,
+	DW_LANG_ObjC_plus_plus = 0x0011,
+	DW_LANG_UPC = 0x0012,
+	DW_LANG_D = 0x0013,
+	// Dwarf4
+	DW_LANG_Python = 0x0014,
+	// Dwarf5
+	DW_LANG_Go = 0x0016,
+
+	DW_LANG_lo_user = 0x8000,
+	DW_LANG_hi_user = 0xffff,
+};
+
+// Table 32
+enum
+{
+	DW_ID_case_sensitive = 0x00,
+	DW_ID_up_case = 0x01,
+	DW_ID_down_case = 0x02,
+	DW_ID_case_insensitive = 0x03,
+};
+
+// Table 33
+enum
+{
+	DW_CC_normal = 0x01,
+	DW_CC_program = 0x02,
+	DW_CC_nocall = 0x03,
+	DW_CC_lo_user = 0x40,
+	DW_CC_hi_user = 0xff,
+};
+
+// Table 34
+enum
+{
+	DW_INL_not_inlined = 0x00,
+	DW_INL_inlined = 0x01,
+	DW_INL_declared_not_inlined = 0x02,
+	DW_INL_declared_inlined = 0x03,
+};
+
+// Table 35
+enum
+{
+	DW_ORD_row_major = 0x00,
+	DW_ORD_col_major = 0x01,
+};
+
+// Table 36
+enum
+{
+	DW_DSC_label = 0x00,
+	DW_DSC_range = 0x01,
+};
+
+// Table 37
+enum
+{
+	DW_LNS_copy = 0x01,
+	DW_LNS_advance_pc = 0x02,
+	DW_LNS_advance_line = 0x03,
+	DW_LNS_set_file = 0x04,
+	DW_LNS_set_column = 0x05,
+	DW_LNS_negate_stmt = 0x06,
+	DW_LNS_set_basic_block = 0x07,
+	DW_LNS_const_add_pc = 0x08,
+	DW_LNS_fixed_advance_pc = 0x09,
+	// Dwarf3
+	DW_LNS_set_prologue_end = 0x0a,
+	DW_LNS_set_epilogue_begin = 0x0b,
+	DW_LNS_set_isa = 0x0c,
+};
+
+// Table 38
+enum
+{
+	DW_LNE_end_sequence = 0x01,
+	DW_LNE_set_address = 0x02,
+	DW_LNE_define_file = 0x03,
+	DW_LNE_lo_user = 0x80,
+	DW_LNE_hi_user = 0xff,
+};
+
+// Table 39
+enum
+{
+	DW_MACINFO_define = 0x01,
+	DW_MACINFO_undef = 0x02,
+	DW_MACINFO_start_file = 0x03,
+	DW_MACINFO_end_file = 0x04,
+	DW_MACINFO_vendor_ext = 0xff,
+};
+
+// Table 40.
+enum
+{					// operand,...
+	DW_CFA_nop = 0x00,
+	DW_CFA_set_loc = 0x01,		// address
+	DW_CFA_advance_loc1 = 0x02,	// 1-byte delta
+	DW_CFA_advance_loc2 = 0x03,	// 2-byte delta
+	DW_CFA_advance_loc4 = 0x04,	// 4-byte delta
+	DW_CFA_offset_extended = 0x05,	// ULEB128 register, ULEB128 offset
+	DW_CFA_restore_extended = 0x06, // ULEB128 register
+	DW_CFA_undefined = 0x07,	// ULEB128 register
+	DW_CFA_same_value = 0x08,	// ULEB128 register
+	DW_CFA_register = 0x09,		// ULEB128 register, ULEB128 register
+	DW_CFA_remember_state = 0x0a,
+	DW_CFA_restore_state = 0x0b,
+	DW_CFA_def_cfa = 0x0c,		// ULEB128 register, ULEB128 offset
+	DW_CFA_def_cfa_register = 0x0d,	// ULEB128 register
+	DW_CFA_def_cfa_offset = 0x0e,	// ULEB128 offset
+	DW_CFA_def_cfa_expression = 0x0f, // BLOCK
+	DW_CFA_expression = 0x10,	// ULEB128 register, BLOCK
+	DW_CFA_offset_extended_sf = 0x11, // ULEB128 register, SLEB128 offset
+	DW_CFA_def_cfa_sf = 0x12,	// ULEB128 register, SLEB128 offset
+	DW_CFA_def_cfa_offset_sf = 0x13, // SLEB128 offset
+	DW_CFA_val_offset = 0x14,	// ULEB128, ULEB128
+	DW_CFA_val_offset_sf = 0x15,	// ULEB128, SLEB128
+	DW_CFA_val_expression = 0x16,	// ULEB128, BLOCK
+
+	DW_CFA_lo_user = 0x1c,
+	DW_CFA_hi_user = 0x3f,
+
+	// Opcodes that take an addend operand.
+	DW_CFA_advance_loc = 0x1<<6, // +delta
+	DW_CFA_offset	   = 0x2<<6, // +register (ULEB128 offset)
+	DW_CFA_restore	   = 0x3<<6, // +register
+};
diff --git a/src/cmd/ld/elf.c b/src/cmd/ld/elf.c
index c5d58576d..d5b0b0311 100644
--- a/src/cmd/ld/elf.c
+++ b/src/cmd/ld/elf.c
@@ -21,6 +21,16 @@ static	ElfPhdr	*phdr[NSECT];
 static	ElfShdr	*shdr[NSECT];
 static	char	*interp;
 
+typedef struct Elfstring Elfstring;
+struct Elfstring
+{
+	char *s;
+	int off;
+};
+
+static Elfstring elfstr[100];
+static int nelfstr;
+
 /*
  Initialize the global variable that describes the ELF header. It will be updated as
  we write section and prog headers.
@@ -122,6 +132,18 @@ elfwriteshdrs(void)
 	return hdr.shnum * ELF32SHDRSIZE;
 }
 
+void
+elfsetstring(char *s, int off)
+{
+	if(nelfstr >= nelem(elfstr)) {
+		diag("too many elf strings");
+		errorexit();
+	}
+	elfstr[nelfstr].s = s;
+	elfstr[nelfstr].off = off;
+	nelfstr++;
+}
+
 uint32
 elfwritephdrs(void)
 {
@@ -142,8 +164,7 @@ newElfPhdr(void)
 {
 	ElfPhdr *e;
 
-	e = malloc(sizeof *e);
-	memset(e, 0, sizeof *e);
+	e = mal(sizeof *e);
 	if (hdr.phnum >= NSECT)
 		diag("too many phdrs");
 	else
@@ -167,8 +188,7 @@ newElfShdr(vlong name)
 {
 	ElfShdr *e;
 
-	e = malloc(sizeof *e);
-	memset(e, 0, sizeof *e);
+	e = mal(sizeof *e);
 	e->name = name;
 	if (hdr.shnum >= NSECT) {
 		diag("too many shdrs");
@@ -294,7 +314,7 @@ elfwriteinterp(void)
 
 	n = strlen(interp)+1;
 	seek(cout, ELFRESERVE-n, 0);
-	write(cout, interp, n);
+	ewrite(cout, interp, n);
 	return n;
 }
 
@@ -310,17 +330,25 @@ elfinterp(ElfShdr *sh, uint64 startva, char *p)
 	sh->size = n;
 }
 
+extern int nelfsym;
+
 void
-elfdynhash(int nsym)
+elfdynhash(void)
 {
 	Sym *s, *sy;
 	int i, h, nbucket, b;
 	uchar *pc;
 	uint32 hc, g;
 	uint32 *chain, *buckets;
+	int nsym;
+	char *name;
+	
+	if(!iself)
+		return;
 
+	nsym = nelfsym;
 	s = lookup(".hash", 0);
-	s->type = SELFDATA;	// TODO: rodata
+	s->type = SELFDATA;
 	s->reachable = 1;
 
 	i = nsym;
@@ -331,17 +359,24 @@ elfdynhash(int nsym)
 	}
 
 	chain = malloc(nsym * sizeof(uint32));
-	memset(chain, 0, nsym * sizeof(uint32));
 	buckets = malloc(nbucket * sizeof(uint32));
+	if(chain == nil || buckets == nil) {
+		cursym = nil;
+		diag("out of memory");
+		errorexit();
+	}
+	memset(chain, 0, nsym * sizeof(uint32));
 	memset(buckets, 0, nbucket * sizeof(uint32));
-	i = 1;
 	for(h = 0; h<NHASH; h++) {
-		for(sy=hash[h]; sy!=S; sy=sy->link) {
-			if (!sy->reachable || (sy->type != STEXT && sy->type != SDATA && sy->type != SBSS) || sy->dynimpname == nil)
+		for(sy=hash[h]; sy!=S; sy=sy->hash) {
+			if (sy->dynid <= 0)
 				continue;
 
 			hc = 0;
-			for(pc = (uchar*)sy->dynimpname; *pc; pc++) {
+			name = sy->dynimpname;
+			if(name == nil)
+				name = sy->name;
+			for(pc = (uchar*)name; *pc; pc++) {
 				hc = (hc<<4) + *pc;
 				g = hc & 0xf0000000;
 				hc ^= g >> 24;
@@ -349,9 +384,8 @@ elfdynhash(int nsym)
 			}
 
 			b = hc % nbucket;
-			chain[i] = buckets[b];
-			buckets[b] = i;
-			i++;
+			chain[sy->dynid] = buckets[b];
+			buckets[b] = sy->dynid;
 		}
 	}
 
@@ -364,4 +398,64 @@ elfdynhash(int nsym)
 
 	free(chain);
 	free(buckets);
+
+	elfwritedynent(lookup(".dynamic", 0), DT_NULL, 0);
+}
+
+ElfPhdr*
+elfphload(Segment *seg)
+{
+	ElfPhdr *ph;
+	
+	ph = newElfPhdr();
+	ph->type = PT_LOAD;
+	if(seg->rwx & 4)
+		ph->flags |= PF_R;
+	if(seg->rwx & 2)
+		ph->flags |= PF_W;
+	if(seg->rwx & 1)
+		ph->flags |= PF_X;
+	ph->vaddr = seg->vaddr;
+	ph->paddr = seg->vaddr;
+	ph->memsz = seg->len;
+	ph->off = seg->fileoff;
+	ph->filesz = seg->filelen;
+	ph->align = INITRND;
+	
+	return ph;
+}
+
+ElfShdr*
+elfshbits(Section *sect)
+{
+	int i, off;
+	ElfShdr *sh;
+	
+	for(i=0; i<nelfstr; i++) {
+		if(strcmp(sect->name, elfstr[i].s) == 0) {
+			off = elfstr[i].off;
+			goto found;
+		}
+	}
+	diag("cannot find elf name %s", sect->name);
+	errorexit();
+	return nil;
+
+found:
+	sh = newElfShdr(off);
+	if(sect->vaddr < sect->seg->vaddr + sect->seg->filelen)
+		sh->type = SHT_PROGBITS;
+	else
+		sh->type = SHT_NOBITS;
+	sh->flags = SHF_ALLOC;
+	if(sect->rwx & 1)
+		sh->flags |= SHF_EXECINSTR;
+	if(sect->rwx & 2)
+		sh->flags |= SHF_WRITE;
+	sh->addr = sect->vaddr;
+	sh->addralign = PtrSize;
+	sh->size = sect->len;
+	sh->off = sect->seg->fileoff + sect->vaddr - sect->seg->vaddr;
+	
+	return sh;
 }
diff --git a/src/cmd/ld/elf.h b/src/cmd/ld/elf.h
index 9b5fdb17e..df15cb115 100644
--- a/src/cmd/ld/elf.h
+++ b/src/cmd/ld/elf.h
@@ -964,7 +964,10 @@ extern	int	numelfshdr;
 extern	int	iself;
 int	elfwriteinterp(void);
 void	elfinterp(ElfShdr*, uint64, char*);
-void	elfdynhash(int);
+void	elfdynhash(void);
+ElfPhdr* elfphload(Segment*);
+ElfShdr* elfshbits(Section*);
+void	elfsetstring(char*, int);
 
 /*
  * Total amount of space to reserve at the start of the file
@@ -972,5 +975,4 @@ void	elfdynhash(int);
  * May waste some.
  * On FreeBSD, cannot be larger than a page.
  */
-#define	ELFRESERVE	2048
-
+#define	ELFRESERVE	3072
diff --git a/src/cmd/ld/go.c b/src/cmd/ld/go.c
index 015f34db2..8966b2a1f 100644
--- a/src/cmd/ld/go.c
+++ b/src/cmd/ld/go.c
@@ -66,12 +66,11 @@ ilookup(char *name)
 }
 
 static void loadpkgdata(char*, char*, char*, int);
-static void loaddynimport(char*, char*, int);
+static void loaddynimport(char*, char*, char*, int);
 static void loaddynexport(char*, char*, char*, int);
 static int parsemethod(char**, char*, char**);
 static int parsepkgdata(char*, char*, char**, char*, char**, char**, char**);
 
-static int ndynexp;
 static Sym **dynexp;
 
 void
@@ -194,7 +193,7 @@ ldpkg(Biobuf *f, char *pkg, int64 len, char *filename, int whence)
 				errorexit();
 			return;
 		}
-		loaddynimport(filename, p0 + 1, p1 - (p0+1));
+		loaddynimport(filename, pkg, p0 + 1, p1 - (p0+1));
 	}
 
 	// look for dynexp section
@@ -266,6 +265,10 @@ expandpkg(char *t0, char *pkg)
 
 	// use malloc, not mal, so that caller can free
 	w0 = malloc(strlen(t0) + strlen(pkg)*n);
+	if(w0 == nil) {
+		diag("out of memory");
+		errorexit();
+	}
 	w = w0;
 	for(p=t=t0; (p=strstr(p, "\"\".")) != nil; p=t) {
 		memmove(w, t, p - t);
@@ -282,7 +285,7 @@ static int
 parsepkgdata(char *file, char *pkg, char **pp, char *ep, char **prefixp, char **namep, char **defp)
 {
 	char *p, *prefix, *name, *def, *edef, *meth;
-	int n;
+	int n, inquote;
 
 	// skip white space
 	p = *pp;
@@ -319,8 +322,19 @@ loop:
 
 	// name: a.b followed by space
 	name = p;
-	while(p < ep && *p != ' ')
+	inquote = 0;
+	while(p < ep) {
+		if (*p == ' ' && !inquote)
+			break;
+
+		if(*p == '\\')
+			p++;
+		else if(*p == '"')
+			inquote = !inquote;
+
 		p++;
+	}
+
 	if(p >= ep)
 		return -1;
 	*p++ = '\0';
@@ -397,7 +411,7 @@ parsemethod(char **pp, char *ep, char **methp)
 }
 
 static void
-loaddynimport(char *file, char *p, int n)
+loaddynimport(char *file, char *pkg, char *p, int n)
 {
 	char *pend, *next, *name, *def, *p0, *lib;
 	Sym *s;
@@ -431,10 +445,21 @@ loaddynimport(char *file, char *p, int n)
 		// successful parse: now can edit the line
 		*strchr(name, ' ') = 0;
 		*strchr(def, ' ') = 0;
+		
+		if(strcmp(name, "_") == 0 && strcmp(def, "_") == 0) {
+			// allow #pragma dynimport _ _ "foo.so"
+			// to force a link of foo.so.
+			adddynlib(lib);
+			continue;
+		}
 
+		name = expandpkg(name, pkg);
 		s = lookup(name, 0);
-		s->dynimplib = lib;
-		s->dynimpname = def;
+		if(s->type == 0 || s->type == SXREF) {
+			s->dynimplib = lib;
+			s->dynimpname = def;
+			s->type = SDYNIMPORT;
+		}
 	}
 	return;
 
@@ -499,38 +524,19 @@ err:
 static int markdepth;
 
 static void
-markdata(Prog *p, Sym *s)
-{
-	markdepth++;
-	if(p != P && debug['v'] > 1)
-		Bprint(&bso, "%d markdata %s\n", markdepth, s->name);
-	for(; p != P; p=p->dlink)
-		if(p->to.sym)
-			mark(p->to.sym);
-	markdepth--;
-}
-
-static void
-marktext(Prog *p)
+marktext(Sym *s)
 {
 	Auto *a;
+	Prog *p;
 
-	if(p == P)
+	if(s == S)
 		return;
-	if(p->as != ATEXT) {
-		diag("marktext: %P", p);
-		return;
-	}
-	for(a=p->to.autom; a; a=a->link)
-		mark(a->gotype);
 	markdepth++;
 	if(debug['v'] > 1)
-		Bprint(&bso, "%d marktext %s\n", markdepth, p->from.sym->name);
-	for(a=p->to.autom; a; a=a->link)
+		Bprint(&bso, "%d marktext %s\n", markdepth, s->name);
+	for(a=s->autom; a; a=a->link)
 		mark(a->gotype);
-	for(p=p->link; p != P; p=p->link) {
-		if(p->as == ATEXT || p->as == ADATA || p->as == AGLOBL)
-			break;
+	for(p=s->text; p != P; p=p->link) {
 		if(p->from.sym)
 			mark(p->from.sym);
 		if(p->to.sym)
@@ -542,45 +548,21 @@ marktext(Prog *p)
 void
 mark(Sym *s)
 {
+	int i;
+
 	if(s == S || s->reachable)
 		return;
 	s->reachable = 1;
 	if(s->text)
-		marktext(s->text);
-	if(s->data)
-		markdata(s->data, s);
+		marktext(s);
+	for(i=0; i<s->nr; i++)
+		mark(s->r[i].sym);
 	if(s->gotype)
 		mark(s->gotype);
-}
-
-static void
-sweeplist(Prog **first, Prog **last)
-{
-	int reachable;
-	Prog *p, *q;
-
-	reachable = 1;
-	q = P;
-	for(p=*first; p != P; p=p->link) {
-		switch(p->as) {
-		case ATEXT:
-		case ADATA:
-		case AGLOBL:
-			reachable = p->from.sym->reachable;
-		}
-		if(reachable) {
-			if(q == P)
-				*first = p;
-			else
-				q->link = p;
-			q = p;
-		}
-	}
-	if(q == P)
-		*first = P;
-	else
-		q->link = P;
-	*last = q;
+	if(s->sub)
+		mark(s->sub);
+	if(s->outer)
+		mark(s->outer);
 }
 
 static char*
@@ -602,10 +584,43 @@ morename[] =
 	"runtime.morestack48",
 };
 
+static int
+isz(Auto *a)
+{
+	for(; a; a=a->link)
+		if(a->type == D_FILE || a->type == D_FILE1)
+			return 1;
+	return 0;
+}
+
+static void
+addz(Sym *s, Auto *z)
+{
+	Auto *a, *last;
+
+	// strip out non-z
+	last = nil;
+	for(a = z; a != nil; a = a->link) {
+		if(a->type == D_FILE || a->type == D_FILE1) {
+			if(last == nil)
+				z = a;
+			else
+				last->link = a;
+			last = a;
+		}
+	}
+	if(last) {
+		last->link = s->autom;
+		s->autom = z;
+	}
+}
+
 void
 deadcode(void)
 {
 	int i;
+	Sym *s, *last;
+	Auto *z;
 
 	if(debug['v'])
 		Bprint(&bso, "%5.2f deadcode\n", cputime());
@@ -616,7 +631,38 @@ deadcode(void)
 
 	for(i=0; i<ndynexp; i++)
 		mark(dynexp[i]);
+	
+	// remove dead text but keep file information (z symbols).
+	last = nil;
+	z = nil;
+	for(s = textp; s != nil; s = s->next) {
+		if(!s->reachable) {
+			if(isz(s->autom))
+				z = s->autom;
+			continue;
+		}
+		if(last == nil)
+			textp = s;
+		else
+			last->next = s;
+		last = s;
+		if(z != nil) {
+			if(!isz(s->autom))
+				addz(s, z);
+			z = nil;
+		}
+	}
+	if(last == nil)
+		textp = nil;
+	else
+		last->next = nil;
+}
 
-	// remove dead data
-	sweeplist(&datap, &edatap);
+void
+addexport(void)
+{
+	int i;
+	
+	for(i=0; i<ndynexp; i++)
+		adddynsym(dynexp[i]);
 }
diff --git a/src/cmd/ld/ldelf.c b/src/cmd/ld/ldelf.c
new file mode 100644
index 000000000..44bbe68ee
--- /dev/null
+++ b/src/cmd/ld/ldelf.c
@@ -0,0 +1,816 @@
+/*
+Derived from Plan 9 from User Space's src/libmach/elf.h, elf.c
+http://code.swtch.com/plan9port/src/tip/src/libmach/
+
+	Copyright © 2004 Russ Cox.
+	Portions Copyright © 2008-2010 Google Inc.
+	Portions Copyright © 2010 The Go Authors.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#include	"l.h"
+#include	"lib.h"
+#include	"../ld/elf.h"
+
+enum
+{
+	ElfClassNone = 0,
+	ElfClass32,
+	ElfClass64,
+
+	ElfDataNone = 0,
+	ElfDataLsb,
+	ElfDataMsb,
+
+	ElfTypeNone = 0,
+	ElfTypeRelocatable,
+	ElfTypeExecutable,
+	ElfTypeSharedObject,
+	ElfTypeCore,
+	/* 0xFF00 - 0xFFFF reserved for processor-specific types */
+
+	ElfMachNone = 0,
+	ElfMach32100,		/* AT&T WE 32100 */
+	ElfMachSparc,		/* SPARC */
+	ElfMach386,		/* Intel 80386 */
+	ElfMach68000,		/* Motorola 68000 */
+	ElfMach88000,		/* Motorola 88000 */
+	ElfMach486,		/* Intel 80486, no longer used */
+	ElfMach860,		/* Intel 80860 */
+	ElfMachMips,		/* MIPS RS3000 */
+	ElfMachS370,		/* IBM System/370 */
+	ElfMachMipsLe,	/* MIPS RS3000 LE */
+	ElfMachParisc = 15,		/* HP PA RISC */
+	ElfMachVpp500 = 17,	/* Fujitsu VPP500 */
+	ElfMachSparc32Plus,	/* SPARC V8+ */
+	ElfMach960,		/* Intel 80960 */
+	ElfMachPower,		/* PowerPC */
+	ElfMachPower64,	/* PowerPC 64 */
+	ElfMachS390,		/* IBM System/390 */
+	ElfMachV800 = 36,	/* NEC V800 */
+	ElfMachFr20,		/* Fujitsu FR20 */
+	ElfMachRh32,		/* TRW RH-32 */
+	ElfMachRce,		/* Motorola RCE */
+	ElfMachArm,		/* ARM */
+	ElfMachAlpha,		/* Digital Alpha */
+	ElfMachSH,		/* Hitachi SH */
+	ElfMachSparc9,		/* SPARC V9 */
+	ElfMachAmd64 = 62,
+	/* and the list goes on... */
+
+	ElfAbiNone = 0,
+	ElfAbiSystemV = 0,	/* [sic] */
+	ElfAbiHPUX,
+	ElfAbiNetBSD,
+	ElfAbiLinux,
+	ElfAbiSolaris = 6,
+	ElfAbiAix,
+	ElfAbiIrix,
+	ElfAbiFreeBSD,
+	ElfAbiTru64,
+	ElfAbiModesto,
+	ElfAbiOpenBSD,
+	ElfAbiARM = 97,
+	ElfAbiEmbedded = 255,
+
+	/* some of sections 0xFF00 - 0xFFFF reserved for various things */
+	ElfSectNone = 0,
+	ElfSectProgbits,
+	ElfSectSymtab,
+	ElfSectStrtab,
+	ElfSectRela,
+	ElfSectHash,
+	ElfSectDynamic,
+	ElfSectNote,
+	ElfSectNobits,
+	ElfSectRel,
+	ElfSectShlib,
+	ElfSectDynsym,
+
+	ElfSectFlagWrite = 0x1,
+	ElfSectFlagAlloc = 0x2,
+	ElfSectFlagExec = 0x4,
+	/* 0xF0000000 are reserved for processor specific */
+
+	ElfSymBindLocal = 0,
+	ElfSymBindGlobal,
+	ElfSymBindWeak,
+	/* 13-15 reserved */
+
+	ElfSymTypeNone = 0,
+	ElfSymTypeObject,
+	ElfSymTypeFunc,
+	ElfSymTypeSection,
+	ElfSymTypeFile,
+	/* 13-15 reserved */
+
+	ElfSymShnNone = 0,
+	ElfSymShnAbs = 0xFFF1,
+	ElfSymShnCommon = 0xFFF2,
+	/* 0xFF00-0xFF1F reserved for processors */
+	/* 0xFF20-0xFF3F reserved for operating systems */
+
+	ElfProgNone = 0,
+	ElfProgLoad,
+	ElfProgDynamic,
+	ElfProgInterp,
+	ElfProgNote,
+	ElfProgShlib,
+	ElfProgPhdr,
+
+	ElfProgFlagExec = 0x1,
+	ElfProgFlagWrite = 0x2,
+	ElfProgFlagRead = 0x4,
+
+	ElfNotePrStatus = 1,
+	ElfNotePrFpreg = 2,
+	ElfNotePrPsinfo = 3,
+	ElfNotePrTaskstruct = 4,
+	ElfNotePrAuxv = 6,
+	ElfNotePrXfpreg = 0x46e62b7f	/* for gdb/386 */
+};
+
+typedef struct ElfHdrBytes ElfHdrBytes;
+typedef struct ElfSectBytes ElfSectBytes;
+typedef struct ElfProgBytes ElfProgBytes;
+typedef struct ElfSymBytes ElfSymBytes;
+
+typedef struct ElfHdrBytes64 ElfHdrBytes64;
+typedef struct ElfSectBytes64 ElfSectBytes64;
+typedef struct ElfProgBytes64 ElfProgBytes64;
+typedef struct ElfSymBytes64 ElfSymBytes64;
+
+struct ElfHdrBytes
+{
+	uchar	ident[16];
+	uchar	type[2];
+	uchar	machine[2];
+	uchar	version[4];
+	uchar	entry[4];
+	uchar	phoff[4];
+	uchar	shoff[4];
+	uchar	flags[4];
+	uchar	ehsize[2];
+	uchar	phentsize[2];
+	uchar	phnum[2];
+	uchar	shentsize[2];
+	uchar	shnum[2];
+	uchar	shstrndx[2];
+};
+
+struct ElfHdrBytes64
+{
+	uchar	ident[16];
+	uchar	type[2];
+	uchar	machine[2];
+	uchar	version[4];
+	uchar	entry[8];
+	uchar	phoff[8];
+	uchar	shoff[8];
+	uchar	flags[4];
+	uchar	ehsize[2];
+	uchar	phentsize[2];
+	uchar	phnum[2];
+	uchar	shentsize[2];
+	uchar	shnum[2];
+	uchar	shstrndx[2];
+};
+
+struct ElfSectBytes
+{
+	uchar	name[4];
+	uchar	type[4];
+	uchar	flags[4];
+	uchar	addr[4];
+	uchar	off[4];
+	uchar	size[4];
+	uchar	link[4];
+	uchar	info[4];
+	uchar	align[4];
+	uchar	entsize[4];
+};
+
+struct ElfSectBytes64
+{
+	uchar	name[4];
+	uchar	type[4];
+	uchar	flags[8];
+	uchar	addr[8];
+	uchar	off[8];
+	uchar	size[8];
+	uchar	link[4];
+	uchar	info[4];
+	uchar	align[8];
+	uchar	entsize[8];
+};
+
+struct ElfSymBytes
+{
+	uchar	name[4];
+	uchar	value[4];
+	uchar	size[4];
+	uchar	info;	/* top4: bind, bottom4: type */
+	uchar	other;
+	uchar	shndx[2];
+};
+
+struct ElfSymBytes64
+{
+	uchar	name[4];
+	uchar	info;	/* top4: bind, bottom4: type */
+	uchar	other;
+	uchar	shndx[2];
+	uchar	value[8];
+	uchar	size[8];
+};
+
+typedef struct ElfSect ElfSect;
+typedef struct ElfObj ElfObj;
+typedef struct ElfSym ElfSym;
+
+struct ElfSect
+{
+	char		*name;
+	uint32	type;
+	uint64	flags;
+	uint64	addr;
+	uint64	off;
+	uint64	size;
+	uint32	link;
+	uint32	info;
+	uint64	align;
+	uint64	entsize;
+	uchar	*base;
+	Sym	*sym;
+};
+
+struct ElfObj
+{
+	Biobuf	*f;
+	int64	base;	// offset in f where ELF begins
+	int64	len;		// length of ELF
+	int	is64;
+	char	*name;
+
+	Endian	*e;
+	ElfSect	*sect;
+	uint		nsect;
+	char		*shstrtab;
+	int		nsymtab;
+	ElfSect	*symtab;
+	ElfSect	*symstr;
+
+	uint32	type;
+	uint32	machine;
+	uint32	version;
+	uint64	entry;
+	uint64	phoff;
+	uint64	shoff;
+	uint32	flags;
+	uint32	ehsize;
+	uint32	phentsize;
+	uint32	phnum;
+	uint32	shentsize;
+	uint32	shnum;
+	uint32	shstrndx;
+};
+
+struct ElfSym
+{
+	char*	name;
+	uint64	value;
+	uint64	size;
+	uchar	bind;
+	uchar	type;
+	uchar	other;
+	uint16	shndx;
+	Sym*	sym;
+};
+
+uchar ElfMagic[4] = { 0x7F, 'E', 'L', 'F' };
+
+static ElfSect*	section(ElfObj*, char*);
+static int	map(ElfObj*, ElfSect*);
+static int	readsym(ElfObj*, int i, ElfSym*);
+static int	reltype(char*, int, uchar*);
+
+void
+ldelf(Biobuf *f, char *pkg, int64 len, char *pn)
+{
+	int32 base;
+	uint64 add, info;
+	char *name;
+	int i, j, rela, is64, n;
+	uchar hdrbuf[64];
+	uchar *p, *dp;
+	ElfHdrBytes *hdr;
+	ElfObj *obj;
+	ElfSect *sect, *rsect;
+	ElfSym sym;
+	Endian *e;
+	Reloc *r, *rp;
+	Sym *s;
+
+	if(debug['v'])
+		Bprint(&bso, "%5.2f ldelf %s\n", cputime(), pn);
+
+	version++;
+	base = Boffset(f);
+
+	if(Bread(f, &hdrbuf, sizeof hdrbuf) != sizeof hdrbuf)
+		goto bad;
+	hdr = (ElfHdrBytes*)&hdrbuf;
+	if(memcmp(hdr->ident, ElfMagic, 4) != 0)
+		goto bad;
+	switch(hdr->ident[5]) {
+	case ElfDataLsb:
+		e = &le;
+		break;
+	case ElfDataMsb:
+		e = &be;
+		break;
+	default:
+		goto bad;
+	}
+
+	// read header
+	obj = mal(sizeof *obj);
+	obj->e = e;
+	obj->f = f;
+	obj->base = base;
+	obj->len = len;
+	obj->name = pn;
+	
+	is64 = 0;
+	if(hdr->ident[4] == ElfClass64) {
+		ElfHdrBytes64* hdr;
+
+		is64 = 1;
+		hdr = (ElfHdrBytes64*)hdrbuf;
+		obj->type = e->e16(hdr->type);
+		obj->machine = e->e16(hdr->machine);
+		obj->version = e->e32(hdr->version);
+		obj->phoff = e->e64(hdr->phoff);
+		obj->shoff = e->e64(hdr->shoff);
+		obj->flags = e->e32(hdr->flags);
+		obj->ehsize = e->e16(hdr->ehsize);
+		obj->phentsize = e->e16(hdr->phentsize);
+		obj->phnum = e->e16(hdr->phnum);
+		obj->shentsize = e->e16(hdr->shentsize);
+		obj->shnum = e->e16(hdr->shnum);
+		obj->shstrndx = e->e16(hdr->shstrndx);
+	} else {
+		obj->type = e->e16(hdr->type);
+		obj->machine = e->e16(hdr->machine);
+		obj->version = e->e32(hdr->version);
+		obj->entry = e->e32(hdr->entry);
+		obj->phoff = e->e32(hdr->phoff);
+		obj->shoff = e->e32(hdr->shoff);
+		obj->flags = e->e32(hdr->flags);
+		obj->ehsize = e->e16(hdr->ehsize);
+		obj->phentsize = e->e16(hdr->phentsize);
+		obj->phnum = e->e16(hdr->phnum);
+		obj->shentsize = e->e16(hdr->shentsize);
+		obj->shnum = e->e16(hdr->shnum);
+		obj->shstrndx = e->e16(hdr->shstrndx);
+	}
+	obj->is64 = is64;
+	
+	if(hdr->ident[6] != obj->version)
+		goto bad;
+
+	if(e->e16(hdr->type) != ElfTypeRelocatable) {
+		diag("%s: elf but not elf relocatable object");
+		return;
+	}
+
+	switch(thechar) {
+	default:
+		diag("%s: elf %s unimplemented", thestring);
+		return;
+	case '5':
+		if(e != &le || obj->machine != ElfMachArm || hdr->ident[4] != ElfClass32) {
+			diag("%s: elf object but not arm", pn);
+			return;
+		}
+		break;
+	case '6':
+		if(e != &le || obj->machine != ElfMachAmd64 || hdr->ident[4] != ElfClass64) {
+			diag("%s: elf object but not amd64", pn);
+			return;
+		}
+		break;
+	case '8':
+		if(e != &le || obj->machine != ElfMach386 || hdr->ident[4] != ElfClass32) {
+			diag("%s: elf object but not 386", pn);
+			return;
+		}
+		break;
+	}
+
+	// load section list into memory.
+	obj->sect = mal(obj->shnum*sizeof obj->sect[0]);
+	obj->nsect = obj->shnum;
+	for(i=0; i<obj->nsect; i++) {
+		if(Bseek(f, base+obj->shoff+i*obj->shentsize, 0) < 0)
+			goto bad;
+		sect = &obj->sect[i];
+		if(is64) {
+			ElfSectBytes64 b;
+
+			werrstr("short read");
+			if(Bread(f, &b, sizeof b) != sizeof b)
+				goto bad;
+
+			sect->name = (char*)(uintptr)e->e32(b.name);
+			sect->type = e->e32(b.type);
+			sect->flags = e->e64(b.flags);
+			sect->addr = e->e64(b.addr);
+			sect->off = e->e64(b.off);
+			sect->size = e->e64(b.size);
+			sect->link = e->e32(b.link);
+			sect->info = e->e32(b.info);
+			sect->align = e->e64(b.align);
+			sect->entsize = e->e64(b.entsize);
+		} else {
+			ElfSectBytes b;
+
+			werrstr("short read");
+			if(Bread(f, &b, sizeof b) != sizeof b)
+				goto bad;
+		
+			sect->name = (char*)(uintptr)e->e32(b.name);
+			sect->type = e->e32(b.type);
+			sect->flags = e->e32(b.flags);
+			sect->addr = e->e32(b.addr);
+			sect->off = e->e32(b.off);
+			sect->size = e->e32(b.size);
+			sect->link = e->e32(b.link);
+			sect->info = e->e32(b.info);
+			sect->align = e->e32(b.align);
+			sect->entsize = e->e32(b.entsize);
+		}
+	}
+
+	// read section string table and translate names
+	if(obj->shstrndx >= obj->nsect) {
+		werrstr("shstrndx out of range %d >= %d", obj->shstrndx, obj->nsect);
+		goto bad;
+	}
+	sect = &obj->sect[obj->shstrndx];
+	if(map(obj, sect) < 0)
+		goto bad;
+	for(i=0; i<obj->nsect; i++)
+		if(obj->sect[i].name != nil)
+			obj->sect[i].name = (char*)sect->base + (uintptr)obj->sect[i].name;
+	
+	// load string table for symbols into memory.
+	obj->symtab = section(obj, ".symtab");
+	if(obj->symtab == nil) {
+		// our work is done here - no symbols means nothing can refer to this file
+		return;
+	}
+	if(obj->symtab->link <= 0 || obj->symtab->link >= obj->nsect) {
+		diag("%s: elf object has symbol table with invalid string table link", pn);
+		return;
+	}
+	obj->symstr = &obj->sect[obj->symtab->link];
+	if(is64)
+		obj->nsymtab = obj->symtab->size / sizeof(ElfSymBytes64);
+	else
+		obj->nsymtab = obj->symtab->size / sizeof(ElfSymBytes);
+	
+	if(map(obj, obj->symtab) < 0)
+		goto bad;
+	if(map(obj, obj->symstr) < 0)
+		goto bad;
+
+	// load text and data segments into memory.
+	// they are not as small as the section lists, but we'll need
+	// the memory anyway for the symbol images, so we might
+	// as well use one large chunk.
+	
+	// create symbols for mapped sections
+	for(i=0; i<obj->nsect; i++) {
+		sect = &obj->sect[i];
+		if((sect->type != ElfSectProgbits && sect->type != ElfSectNobits) || !(sect->flags&ElfSectFlagAlloc))
+			continue;
+		if(sect->type != ElfSectNobits && map(obj, sect) < 0)
+			goto bad;
+		
+		name = smprint("%s(%s)", pn, sect->name);
+		s = lookup(name, version);
+		free(name);
+		switch(sect->flags&(ElfSectFlagAlloc|ElfSectFlagWrite|ElfSectFlagExec)) {
+		default:
+			werrstr("unexpected flags for ELF section %s", sect->name);
+			goto bad;
+		case ElfSectFlagAlloc:
+			s->type = SRODATA;
+			break;
+		case ElfSectFlagAlloc + ElfSectFlagWrite:
+			s->type = SDATA;
+			break;
+		case ElfSectFlagAlloc + ElfSectFlagExec:
+			s->type = STEXT;
+			break;
+		}
+		if(sect->type == ElfSectProgbits) {
+			s->p = sect->base;
+			s->np = sect->size;
+		}
+		s->size = sect->size;
+		if(s->type == STEXT) {
+			if(etextp)
+				etextp->next = s;
+			else
+				textp = s;
+			etextp = s;
+		}
+		sect->sym = s;
+	}		
+
+	// load relocations
+	for(i=0; i<obj->nsect; i++) {
+		rsect = &obj->sect[i];
+		if(rsect->type != ElfSectRela && rsect->type != ElfSectRel)
+			continue;
+		if(rsect->info >= obj->nsect || obj->sect[rsect->info].base == nil)
+			continue;
+		sect = &obj->sect[rsect->info];
+		if(map(obj, rsect) < 0)
+			goto bad;
+		rela = rsect->type == ElfSectRela;
+		n = rsect->size/(4+4*is64)/(2+rela);
+		r = mal(n*sizeof r[0]);
+		p = rsect->base;
+		dp = sect->base;
+		for(j=0; j<n; j++) {
+			add = 0;
+			rp = &r[j];
+			if(is64) {
+				// 64-bit rel/rela
+				rp->off = e->e64(p);
+				p += 8;
+				info = e->e64(p);
+				p += 8;
+				if(rela) {
+					add = e->e64(p);
+					p += 8;
+				}
+			} else {
+				// 32-bit rel/rela
+				rp->off = e->e32(p);
+				p += 4;
+				info = e->e32(p);
+				info = info>>8<<32 | (info&0xff);	// convert to 64-bit info
+				p += 4;
+				if(rela) {
+					add = e->e32(p);
+					p += 4;
+				}
+			}
+			if(readsym(obj, info>>32, &sym) < 0)
+				goto bad;
+			if(sym.sym == nil) {
+				werrstr("%s#%d: reloc of invalid sym #%d %s shndx=%d type=%d",
+					sect->sym->name, j, (int)(info>>32), sym.name, sym.shndx, sym.type);
+				goto bad;
+			}
+			rp->sym = sym.sym;
+			rp->type = reltype(pn, (uint32)info, &rp->siz);
+			if(rela)
+				rp->add = add;
+			else {
+				// load addend from image
+				if(rp->siz == 4)
+					rp->add = e->e32(sect->base+rp->off);
+				else if(rp->siz == 8)
+					rp->add = e->e64(sect->base+rp->off);
+				else
+					diag("invalid rela size %d", rp->siz);
+			}
+		}
+		qsort(r, n, sizeof r[0], rbyoff);	// just in case
+		
+		s = sect->sym;
+		s->r = r;
+		s->nr = n;
+	}
+
+	// enter sub-symbols into symbol table.
+	// symbol 0 is the null symbol.
+	for(i=1; i<obj->nsymtab; i++) {
+		if(readsym(obj, i, &sym) < 0)
+			goto bad;
+		if(sym.type != ElfSymTypeFunc && sym.type != ElfSymTypeObject && sym.type != ElfSymTypeNone)
+			continue;
+		if(sym.shndx == ElfSymShnCommon) {
+			s = sym.sym;
+			if(s->size < sym.size)
+				s->size = sym.size;
+			if(s->type == 0 || s->type == SXREF)
+				s->type = SBSS;
+			continue;
+		}
+		if(sym.shndx >= obj->nsect || sym.shndx == 0)
+			continue;
+		sect = obj->sect+sym.shndx;
+		if(sect->sym == nil) {
+			diag("%s: sym#%d: ignoring %s in section %d (type %d)", pn, i, sym.name, sym.shndx, sym.type);
+			continue;
+		}
+		s = sym.sym;
+		s->sub = sect->sym->sub;
+		sect->sym->sub = s;
+		s->type = sect->sym->type | SSUB;
+		if(!s->dynexport) {
+			s->dynimplib = nil;  // satisfy dynimport
+			s->dynimpname = nil;  // satisfy dynimport
+		}
+		s->value = sym.value;
+		s->size = sym.size;
+		s->outer = sect->sym;
+		if(sect->sym->type == STEXT) {
+			Prog *p;
+
+			if(s->text != P)
+				diag("%s: duplicate definition of %s", pn, s->name);
+			// build a TEXT instruction with a unique pc
+			// just to make the rest of the linker happy.
+			p = prg();
+			p->as = ATEXT;
+			p->from.type = D_EXTERN;
+			p->from.sym = s;
+			p->textflag = 7;
+			p->to.type = D_CONST;
+			p->link = nil;
+			p->pc = pc++;
+			s->text = p;
+
+			etextp->next = s;
+			etextp = s;
+		}
+	}
+	return;
+
+bad:
+	diag("%s: malformed elf file: %r", pn);
+}
+
+static ElfSect*
+section(ElfObj *obj, char *name)
+{
+	int i;
+	
+	for(i=0; i<obj->nsect; i++)
+		if(obj->sect[i].name && name && strcmp(obj->sect[i].name, name) == 0)
+			return &obj->sect[i];
+	return nil;
+}
+
+static int
+map(ElfObj *obj, ElfSect *sect)
+{
+	if(sect->base != nil)
+		return 0;
+
+	if(sect->off+sect->size > obj->len) {
+		werrstr("elf section past end of file");
+		return -1;
+	}
+
+	sect->base = mal(sect->size);
+	werrstr("short read");
+	if(Bseek(obj->f, obj->base+sect->off, 0) < 0 || Bread(obj->f, sect->base, sect->size) != sect->size)
+		return -1;
+	
+	return 0;
+}
+
+static int
+readsym(ElfObj *obj, int i, ElfSym *sym)
+{
+	Sym *s;
+
+	if(i >= obj->nsymtab || i < 0) {
+		werrstr("invalid elf symbol index");
+		return -1;
+	}
+
+	if(obj->is64) {
+		ElfSymBytes64 *b;
+		
+		b = (ElfSymBytes64*)(obj->symtab->base + i*sizeof *b);
+		sym->name = (char*)obj->symstr->base + obj->e->e32(b->name);
+		sym->value = obj->e->e64(b->value);
+		sym->size = obj->e->e64(b->size);
+		sym->shndx = obj->e->e16(b->shndx);
+		sym->bind = b->info>>4;
+		sym->type = b->info&0xf;
+		sym->other = b->other;
+	} else {
+		ElfSymBytes *b;
+		
+		b = (ElfSymBytes*)(obj->symtab->base + i*sizeof *b);
+		sym->name = (char*)obj->symstr->base + obj->e->e32(b->name);
+		sym->value = obj->e->e32(b->value);
+		sym->size = obj->e->e32(b->size);
+		sym->shndx = obj->e->e16(b->shndx);
+		sym->bind = b->info>>4;
+		sym->type = b->info&0xf;
+		sym->other = b->other;
+	}
+
+	s = nil;
+	if(strcmp(sym->name, "_GLOBAL_OFFSET_TABLE_") == 0)
+		sym->name = ".got";
+	if(strcmp(sym->name, "__stack_chk_fail_local") == 0)
+		sym->other = 0;  // rewrite hidden -> default visibility
+	switch(sym->type) {
+	case ElfSymTypeSection:
+		s = obj->sect[sym->shndx].sym;
+		break;
+	case ElfSymTypeObject:
+	case ElfSymTypeFunc:
+	case ElfSymTypeNone:
+		switch(sym->bind) {
+		case ElfSymBindGlobal:
+			if(sym->other != 2) {
+				s = lookup(sym->name, 0);
+				break;
+			}
+			// fall through
+		case ElfSymBindLocal:
+			s = lookup(sym->name, version);
+			break;
+		default:
+			werrstr("%s: invalid symbol binding %d", sym->name, sym->bind);
+			return -1;
+		}
+		break;
+	}
+	if(s != nil && s->type == 0 && sym->type != ElfSymTypeSection)
+		s->type = SXREF;
+	sym->sym = s;
+
+	return 0;
+}
+
+int
+rbyoff(const void *va, const void *vb)
+{
+	Reloc *a, *b;
+	
+	a = (Reloc*)va;
+	b = (Reloc*)vb;
+	if(a->off < b->off)
+		return -1;
+	if(a->off > b->off)
+		return +1;
+	return 0;
+}
+
+#define R(x, y) ((x)|((y)<<24))
+
+static int
+reltype(char *pn, int elftype, uchar *siz)
+{
+	switch(R(thechar, elftype)) {
+	default:
+		diag("%s: unknown relocation type %d; compiled without -fpic?", pn, elftype);
+	case R('6', R_X86_64_PC32):
+	case R('6', R_X86_64_PLT32):
+	case R('6', R_X86_64_GOTPCREL):
+	case R('8', R_386_32):
+	case R('8', R_386_PC32):
+	case R('8', R_386_GOT32):
+	case R('8', R_386_PLT32):
+	case R('8', R_386_GOTOFF):
+	case R('8', R_386_GOTPC):
+		*siz = 4;
+		break;
+	case R('6', R_X86_64_64):
+		*siz = 8;
+		break;
+	}
+
+	return 256+elftype;
+}
diff --git a/src/cmd/ld/ldmacho.c b/src/cmd/ld/ldmacho.c
new file mode 100644
index 000000000..7e38db0e4
--- /dev/null
+++ b/src/cmd/ld/ldmacho.c
@@ -0,0 +1,794 @@
+/*
+Derived from Plan 9 from User Space's src/libmach/elf.h, elf.c
+http://code.swtch.com/plan9port/src/tip/src/libmach/
+
+	Copyright © 2004 Russ Cox.
+	Portions Copyright © 2008-2010 Google Inc.
+	Portions Copyright © 2010 The Go Authors.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#include	"l.h"
+#include	"lib.h"
+
+enum {
+	MACHO_FAKE_GOTPCREL = 100,	// from macho.h
+	
+	N_EXT = 0x01,
+	N_TYPE = 0x1e,
+	N_STAB = 0xe0,
+};
+
+typedef struct MachoObj MachoObj;
+typedef struct MachoCmd MachoCmd;
+typedef struct MachoSeg MachoSeg;
+typedef struct MachoSect MachoSect;
+typedef struct MachoRel MachoRel;
+typedef struct MachoSymtab MachoSymtab;
+typedef struct MachoSym MachoSym;
+typedef struct MachoDysymtab MachoDysymtab;
+
+enum
+{
+	MachoCpuVax = 1,
+	MachoCpu68000 = 6,
+	MachoCpu386 = 7,
+	MachoCpuAmd64 = 0x1000007,
+	MachoCpuMips = 8,
+	MachoCpu98000 = 10,
+	MachoCpuHppa = 11,
+	MachoCpuArm = 12,
+	MachoCpu88000 = 13,
+	MachoCpuSparc = 14,
+	MachoCpu860 = 15,
+	MachoCpuAlpha = 16,
+	MachoCpuPower = 18,
+
+	MachoCmdSegment = 1,
+	MachoCmdSymtab = 2,
+	MachoCmdSymseg = 3,
+	MachoCmdThread = 4,
+	MachoCmdDysymtab = 11,
+	MachoCmdSegment64 = 25,
+
+	MachoFileObject = 1,
+	MachoFileExecutable = 2,
+	MachoFileFvmlib = 3,
+	MachoFileCore = 4,
+	MachoFilePreload = 5,
+};
+
+struct MachoSeg
+{
+	char name[16+1];
+	uint64 vmaddr;
+	uint64 vmsize;
+	uint32 fileoff;
+	uint32 filesz;
+	uint32 maxprot;
+	uint32 initprot;
+	uint32 nsect;
+	uint32 flags;
+	MachoSect *sect;
+};
+
+struct MachoSect
+{
+	char	name[16+1];
+	char	segname[16+1];
+	uint64 addr;
+	uint64 size;
+	uint32 off;
+	uint32 align;
+	uint32 reloff;
+	uint32 nreloc;
+	uint32 flags;
+	uint32 res1;
+	uint32 res2;
+	Sym *sym;
+	
+	MachoRel *rel;
+};
+
+struct MachoRel
+{
+	uint32 addr;
+	uint32 symnum;
+	uint8 pcrel;
+	uint8 length;
+	uint8 extrn;
+	uint8 type;
+	uint8 scattered;
+	uint32 value;
+};
+
+struct MachoSymtab
+{
+	uint32 symoff;
+	uint32 nsym;
+	uint32 stroff;
+	uint32 strsize;
+	
+	char *str;
+	MachoSym *sym;
+};
+
+struct MachoSym
+{
+	char *name;
+	uint8 type;
+	uint8 sectnum;
+	uint16 desc;
+	char kind;
+	uint64 value;
+	Sym *sym;
+};
+
+struct MachoDysymtab
+{
+	uint32 ilocalsym;
+	uint32 nlocalsym;
+	uint32 iextdefsym;
+	uint32 nextdefsym;
+	uint32 iundefsym;
+	uint32 nundefsym;
+	uint32 tocoff;
+	uint32 ntoc;
+	uint32 modtaboff;
+	uint32 nmodtab;
+	uint32 extrefsymoff;
+	uint32 nextrefsyms;
+	uint32 indirectsymoff;
+	uint32 nindirectsyms;
+	uint32 extreloff;
+	uint32 nextrel;
+	uint32 locreloff;
+	uint32 nlocrel;
+	uint32 *indir;
+};
+
+struct MachoCmd
+{
+	int type;
+	uint32 off;
+	uint32 size;
+	MachoSeg seg;
+	MachoSymtab sym;
+	MachoDysymtab dsym;
+};
+
+struct MachoObj
+{
+	Biobuf	*f;
+	int64	base;	// off in f where Mach-O begins
+	int64	len;		// length of Mach-O
+	int is64;
+	char	*name;
+
+	Endian	*e;
+	uint cputype;
+	uint subcputype;
+	uint32 filetype;
+	uint32 flags;
+	MachoCmd *cmd;
+	uint ncmd;
+};
+
+static int
+unpackcmd(uchar *p, MachoObj *m, MachoCmd *c, uint type, uint sz)
+{
+	uint32 (*e4)(uchar*);
+	uint64 (*e8)(uchar*);
+	MachoSect *s;
+	int i;
+
+	e4 = m->e->e32;
+	e8 = m->e->e64;
+
+	c->type = type;
+	c->size = sz;
+	switch(type){
+	default:
+		return -1;
+	case MachoCmdSegment:
+		if(sz < 56)
+			return -1;
+		strecpy(c->seg.name, c->seg.name+sizeof c->seg.name, (char*)p+8);
+		c->seg.vmaddr = e4(p+24);
+		c->seg.vmsize = e4(p+28);
+		c->seg.fileoff = e4(p+32);
+		c->seg.filesz = e4(p+36);
+		c->seg.maxprot = e4(p+40);
+		c->seg.initprot = e4(p+44);
+		c->seg.nsect = e4(p+48);
+		c->seg.flags = e4(p+52);
+		c->seg.sect = mal(c->seg.nsect * sizeof c->seg.sect[0]);
+		if(sz < 56+c->seg.nsect*68)
+			return -1;
+		p += 56;
+		for(i=0; i<c->seg.nsect; i++) {
+			s = &c->seg.sect[i];
+			strecpy(s->name, s->name+sizeof s->name, (char*)p+0);
+			strecpy(s->segname, s->segname+sizeof s->segname, (char*)p+16);
+			s->addr = e4(p+32);
+			s->size = e4(p+36);
+			s->off = e4(p+40);
+			s->align = e4(p+44);
+			s->reloff = e4(p+48);
+			s->nreloc = e4(p+52);
+			s->flags = e4(p+56);
+			s->res1 = e4(p+60);
+			s->res2 = e4(p+64);
+			p += 68;
+		}
+		break;
+	case MachoCmdSegment64:
+		if(sz < 72)
+			return -1;
+		strecpy(c->seg.name, c->seg.name+sizeof c->seg.name, (char*)p+8);
+		c->seg.vmaddr = e8(p+24);
+		c->seg.vmsize = e8(p+32);
+		c->seg.fileoff = e8(p+40);
+		c->seg.filesz = e8(p+48);
+		c->seg.maxprot = e4(p+56);
+		c->seg.initprot = e4(p+60);
+		c->seg.nsect = e4(p+64);
+		c->seg.flags = e4(p+68);
+		c->seg.sect = mal(c->seg.nsect * sizeof c->seg.sect[0]);
+		if(sz < 72+c->seg.nsect*80)
+			return -1;
+		p += 72;
+		for(i=0; i<c->seg.nsect; i++) {
+			s = &c->seg.sect[i];
+			strecpy(s->name, s->name+sizeof s->name, (char*)p+0);
+			strecpy(s->segname, s->segname+sizeof s->segname, (char*)p+16);
+			s->addr = e8(p+32);
+			s->size = e8(p+40);
+			s->off = e4(p+48);
+			s->align = e4(p+52);
+			s->reloff = e4(p+56);
+			s->nreloc = e4(p+60);
+			s->flags = e4(p+64);
+			s->res1 = e4(p+68);
+			s->res2 = e4(p+72);
+			// p+76 is reserved
+			p += 80;
+		}
+		break;
+	case MachoCmdSymtab:
+		if(sz < 24)
+			return -1;
+		c->sym.symoff = e4(p+8);
+		c->sym.nsym = e4(p+12);
+		c->sym.stroff = e4(p+16);
+		c->sym.strsize = e4(p+20);
+		break;
+	case MachoCmdDysymtab:
+		if(sz < 80)
+			return -1;
+		c->dsym.ilocalsym = e4(p+8);
+		c->dsym.nlocalsym = e4(p+12);
+		c->dsym.iextdefsym = e4(p+16);
+		c->dsym.nextdefsym = e4(p+20);
+		c->dsym.iundefsym = e4(p+24);
+		c->dsym.nundefsym = e4(p+28);
+		c->dsym.tocoff = e4(p+32);
+		c->dsym.ntoc = e4(p+36);
+		c->dsym.modtaboff = e4(p+40);
+		c->dsym.nmodtab = e4(p+44);
+		c->dsym.extrefsymoff = e4(p+48);
+		c->dsym.nextrefsyms = e4(p+52);
+		c->dsym.indirectsymoff = e4(p+56);
+		c->dsym.nindirectsyms = e4(p+60);
+		c->dsym.extreloff = e4(p+64);
+		c->dsym.nextrel = e4(p+68);
+		c->dsym.locreloff = e4(p+72);
+		c->dsym.nlocrel = e4(p+76);
+		break;
+	}
+	return 0;
+}
+
+static int
+macholoadrel(MachoObj *m, MachoSect *sect)
+{
+	MachoRel *rel, *r;
+	uchar *buf, *p;
+	int i, n;
+	uint32 v;
+	
+	if(sect->rel != nil || sect->nreloc == 0)
+		return 0;
+	rel = mal(sect->nreloc * sizeof r[0]);
+	n = sect->nreloc * 8;
+	buf = mal(n);
+	if(Bseek(m->f, m->base + sect->reloff, 0) < 0 || Bread(m->f, buf, n) != n)
+		return -1;
+	for(i=0; i<sect->nreloc; i++) {
+		r = &rel[i];
+		p = buf+i*8;
+		r->addr = m->e->e32(p);
+		
+		// TODO(rsc): Wrong interpretation for big-endian bitfields?
+		if(r->addr & 0x80000000) {
+			// scatterbrained relocation
+			r->scattered = 1;
+			v = r->addr >> 24;
+			r->addr &= 0xFFFFFF;
+			r->type = v & 0xF;
+			v >>= 4;
+			r->length = 1<<(v&3);
+			v >>= 2;
+			r->pcrel = v & 1;
+			r->value = m->e->e32(p+4);
+		} else {
+			v = m->e->e32(p+4);
+			r->symnum = v & 0xFFFFFF;
+			v >>= 24;
+			r->pcrel = v&1;
+			v >>= 1;
+			r->length = 1<<(v&3);
+			v >>= 2;
+			r->extrn = v&1;
+			v >>= 1;
+			r->type = v;
+		}
+	}
+	sect->rel = rel;
+	return 0;
+}
+
+static int
+macholoaddsym(MachoObj *m, MachoDysymtab *d)
+{
+	uchar *p;
+	int i, n;
+	
+	n = d->nindirectsyms;
+	
+	p = mal(n*4);
+	if(Bseek(m->f, m->base + d->indirectsymoff, 0) < 0 || Bread(m->f, p, n*4) != n*4)
+		return -1;
+	
+	d->indir = (uint32*)p;
+	for(i=0; i<n; i++)
+		d->indir[i] = m->e->e32(p+4*i);
+	return 0;
+}
+
+static int 
+macholoadsym(MachoObj *m, MachoSymtab *symtab)
+{
+	char *strbuf;
+	uchar *symbuf, *p;
+	int i, n, symsize;
+	MachoSym *sym, *s;
+	uint32 v;
+
+	if(symtab->sym != nil)
+		return 0;
+
+	strbuf = mal(symtab->strsize);
+	if(Bseek(m->f, m->base + symtab->stroff, 0) < 0 || Bread(m->f, strbuf, symtab->strsize) != symtab->strsize)
+		return -1;
+	
+	symsize = 12;
+	if(m->is64)
+		symsize = 16;
+	n = symtab->nsym * symsize;
+	symbuf = mal(n);
+	if(Bseek(m->f, m->base + symtab->symoff, 0) < 0 || Bread(m->f, symbuf, n) != n)
+		return -1;
+	sym = mal(symtab->nsym * sizeof sym[0]);
+	p = symbuf;
+	for(i=0; i<symtab->nsym; i++) {
+		s = &sym[i];
+		v = m->e->e32(p);
+		if(v >= symtab->strsize)
+			return -1;
+		s->name = strbuf + v;
+		s->type = p[4];
+		s->sectnum = p[5];
+		s->desc = m->e->e16(p+6);
+		if(m->is64)
+			s->value = m->e->e64(p+8);
+		else
+			s->value = m->e->e32(p+8);
+		p += symsize;
+	}
+	symtab->str = strbuf;
+	symtab->sym = sym;
+	return 0;
+}
+
+void
+ldmacho(Biobuf *f, char *pkg, int64 len, char *pn)
+{
+	int i, j, is64;
+	uchar hdr[7*4], *cmdp;
+	uchar tmp[4];
+	uchar *dat;
+	ulong ncmd, cmdsz, ty, sz, off;
+	MachoObj *m;
+	Endian *e;
+	int64 base;
+	MachoSect *sect;
+	MachoRel *rel;
+	Sym *s, *outer;
+	MachoCmd *c;
+	MachoSymtab *symtab;
+	MachoDysymtab *dsymtab;
+	MachoSym *sym;
+	Reloc *r, *rp;
+	char *name;
+
+	version++;
+	base = Boffset(f);
+	if(Bread(f, hdr, sizeof hdr) != sizeof hdr)
+		goto bad;
+
+	if((be.e32(hdr)&~1) == 0xFEEDFACE){
+		e = &be;
+	}else if((le.e32(hdr)&~1) == 0xFEEDFACE){
+		e = &le;
+	}else{
+		werrstr("bad magic - not mach-o file");
+		goto bad;
+	}
+
+	is64 = e->e32(hdr) == 0xFEEDFACF;
+	ncmd = e->e32(hdr+4*4);
+	cmdsz = e->e32(hdr+5*4);
+	if(ncmd > 0x10000 || cmdsz >= 0x01000000){
+		werrstr("implausible mach-o header ncmd=%lud cmdsz=%lud", ncmd, cmdsz);
+		goto bad;
+	}
+	if(is64)
+		Bread(f, tmp, 4);	// skip reserved word in header
+
+	m = mal(sizeof(*m)+ncmd*sizeof(MachoCmd)+cmdsz);
+	m->f = f;
+	m->e = e;
+	m->cputype = e->e32(hdr+1*4);
+	m->subcputype = e->e32(hdr+2*4);
+	m->filetype = e->e32(hdr+3*4);
+	m->ncmd = ncmd;
+	m->flags = e->e32(hdr+6*4);
+	m->is64 = is64;
+	m->base = base;
+	m->len = len;
+	m->name = pn;
+	
+	switch(thechar) {
+	default:
+		diag("%s: mach-o %s unimplemented", thestring);
+		return;
+	case '6':
+		if(e != &le || m->cputype != MachoCpuAmd64) {
+			diag("%s: mach-o object but not amd64", pn);
+			return;
+		}
+		break;
+	case '8':
+		if(e != &le || m->cputype != MachoCpu386) {
+			diag("%s: mach-o object but not 386", pn);
+			return;
+		}
+		break;
+	}
+
+	m->cmd = (MachoCmd*)(m+1);
+	off = sizeof hdr;
+	cmdp = (uchar*)(m->cmd+ncmd);
+	if(Bread(f, cmdp, cmdsz) != cmdsz){
+		werrstr("reading cmds: %r");
+		goto bad;
+	}
+
+	// read and parse load commands
+	c = nil;
+	symtab = nil;
+	dsymtab = nil;
+	for(i=0; i<ncmd; i++){
+		ty = e->e32(cmdp);
+		sz = e->e32(cmdp+4);
+		m->cmd[i].off = off;
+		unpackcmd(cmdp, m, &m->cmd[i], ty, sz);
+		cmdp += sz;
+		off += sz;
+		if(ty == MachoCmdSymtab) {
+			if(symtab != nil) {
+				werrstr("multiple symbol tables");
+				goto bad;
+			}
+			symtab = &m->cmd[i].sym;
+			macholoadsym(m, symtab);
+		}
+		if(ty == MachoCmdDysymtab) {
+			dsymtab = &m->cmd[i].dsym;
+			macholoaddsym(m, dsymtab);
+		}
+		if((is64 && ty == MachoCmdSegment64) || (!is64 && ty == MachoCmdSegment)) {
+			if(c != nil) {
+				werrstr("multiple load commands");
+				goto bad;
+			}
+			c = &m->cmd[i];
+		}
+	}
+
+	// load text and data segments into memory.
+	// they are not as small as the load commands, but we'll need
+	// the memory anyway for the symbol images, so we might
+	// as well use one large chunk.
+	if(c == nil) {
+		werrstr("no load command");
+		goto bad;
+	}
+	if(symtab == nil) {
+		// our work is done here - no symbols means nothing can refer to this file
+		return;
+	}
+
+	if(c->seg.fileoff+c->seg.filesz >= len) {
+		werrstr("load segment out of range");
+		goto bad;
+	}
+
+	dat = mal(c->seg.filesz);
+	if(Bseek(f, m->base + c->seg.fileoff, 0) < 0 || Bread(f, dat, c->seg.filesz) != c->seg.filesz) {
+		werrstr("cannot load object data: %r");
+		goto bad;
+	}
+	
+	for(i=0; i<c->seg.nsect; i++) {
+		sect = &c->seg.sect[i];
+		if(strcmp(sect->segname, "__TEXT") != 0 && strcmp(sect->segname, "__DATA") != 0)
+			continue;
+		if(strcmp(sect->name, "__eh_frame") == 0)
+			continue;
+		name = smprint("%s(%s/%s)", pn, sect->segname, sect->name);
+		s = lookup(name, version);
+		if(s->type != 0) {
+			werrstr("duplicate %s/%s", sect->segname, sect->name);
+			goto bad;
+		}
+		free(name);
+		s->p = dat + sect->addr - c->seg.vmaddr;
+		s->np = sect->size;
+		s->size = s->np;
+		
+		if(strcmp(sect->segname, "__TEXT") == 0) {
+			if(strcmp(sect->name, "__text") == 0)
+				s->type = STEXT;
+			else
+				s->type = SRODATA;
+		} else {
+			s->type = SDATA;
+		}
+		if(s->type == STEXT) {
+			if(etextp)
+				etextp->next = s;
+			else
+				textp = s;
+			etextp = s;
+		}
+		sect->sym = s;
+	}
+	
+	// enter sub-symbols into symbol table.
+	// have to guess sizes from next symbol.
+	for(i=0; i<symtab->nsym; i++) {
+		int v;
+		sym = &symtab->sym[i];
+		if(sym->type&N_STAB)
+			continue;
+		// TODO: check sym->type against outer->type.
+		name = sym->name;
+		if(name[0] == '_' && name[1] != '\0')
+			name++;
+		v = 0;
+		if(!(sym->type&N_EXT))
+			v = version;
+		s = lookup(name, v);
+		sym->sym = s;
+		if(sym->sectnum == 0)	// undefined
+			continue;
+		if(sym->sectnum > c->seg.nsect) {
+			werrstr("reference to invalid section %d", sym->sectnum);
+			goto bad;
+		}
+		sect = &c->seg.sect[sym->sectnum-1];
+		outer = sect->sym;
+		if(outer == nil) {
+			werrstr("reference to invalid section %s/%s", sect->segname, sect->name);
+			continue;
+		}
+		s->type = outer->type | SSUB;
+		s->sub = outer->sub;
+		outer->sub = s;
+		s->outer = outer;
+		s->value = sym->value - sect->addr;
+		if(i+1 < symtab->nsym)
+			s->size = (sym+1)->value - sym->value;
+		else
+			s->size = sect->addr + sect->size - sym->value;
+		if(!s->dynexport) {
+			s->dynimplib = nil;	// satisfy dynimport
+			s->dynimpname = nil;	// satisfy dynimport
+		}
+		if(outer->type == STEXT) {
+			Prog *p;
+
+			if(s->text != P)
+				diag("%s sym#%d: duplicate definition of %s", pn, i, s->name);
+			// build a TEXT instruction with a unique pc
+			// just to make the rest of the linker happy.
+			// TODO: this is too 6l-specific ?
+			p = prg();
+			p->as = ATEXT;
+			p->from.type = D_EXTERN;
+			p->from.sym = s;
+			p->textflag = 7;
+			p->to.type = D_CONST;
+			p->link = nil;
+			p->pc = pc++;
+			s->text = p;
+
+			etextp->next = s;
+			etextp = s;
+		}
+		sym->sym = s;
+	}
+
+	// load relocations
+	for(i=0; i<c->seg.nsect; i++) {
+		sect = &c->seg.sect[i];
+		if((s = sect->sym) == S)
+			continue;
+		macholoadrel(m, sect);
+		if(sect->rel == nil)
+			continue;
+		r = mal(sect->nreloc*sizeof r[0]);
+		rp = r;
+		rel = sect->rel;
+		for(j=0; j<sect->nreloc; j++, rel++) {
+			if(rel->scattered) {
+				int k;
+				MachoSect *ks;
+
+				if(thechar != '8')
+					diag("unexpected scattered relocation");
+
+				// on 386, rewrite scattered 4/1 relocation into
+				// the pseudo-pc-relative reference that it is.
+				// assume that the second in the pair is in this section
+				// and use that as the pc-relative base.
+				if(thechar != '8' || rel->type != 4 || j+1 >= sect->nreloc ||
+						!(rel+1)->scattered || (rel+1)->type != 1 ||
+						(rel+1)->value < sect->addr || (rel+1)->value >= sect->addr+sect->size) {
+					werrstr("unsupported scattered relocation %d/%d", (int)rel->type, (int)(rel+1)->type);
+					goto bad;
+				}
+				rp->siz = rel->length;
+				rp->off = rel->addr;
+				
+				// NOTE(rsc): I haven't worked out why (really when)
+				// we should ignore the addend on a
+				// scattered relocation, but it seems that the
+				// common case is we ignore it.
+				// It's likely that this is not strictly correct
+				// and that the math should look something
+				// like the non-scattered case below.
+				rp->add = 0;
+				
+				// want to make it pc-relative aka relative to rp->off+4
+				// but the scatter asks for relative to off = (rel+1)->value - sect->addr.
+				// adjust rp->add accordingly.
+				rp->type = D_PCREL;
+				rp->add += (rp->off+4) - ((rel+1)->value - sect->addr);
+				
+				// now consider the desired symbol.
+				// find the section where it lives.
+				for(k=0; k<c->seg.nsect; k++) {
+					ks = &c->seg.sect[k];
+					if(ks->addr <= rel->value && rel->value < ks->addr+ks->size)
+						goto foundk;
+				}
+				werrstr("unsupported scattered relocation: invalid address %#ux", rel->addr);
+				goto bad;
+			foundk:
+				if(ks->sym != S) {
+					rp->sym = ks->sym;
+					rp->add += rel->value - ks->addr;
+				} else if(strcmp(ks->segname, "__IMPORT") == 0 && strcmp(ks->name, "__pointers") == 0) {
+					// handle reference to __IMPORT/__pointers.
+					// how much worse can this get?
+					// why are we supporting 386 on the mac anyway?
+					rp->type = 512 + MACHO_FAKE_GOTPCREL;
+					// figure out which pointer this is a reference to.
+					k = ks->res1 + (rel->value - ks->addr) / 4;
+					// load indirect table for __pointers
+					// fetch symbol number
+					if(dsymtab == nil || k < 0 || k >= dsymtab->nindirectsyms || dsymtab->indir == nil) {
+						werrstr("invalid scattered relocation: indirect symbol reference out of range");
+						goto bad;
+					}
+					k = dsymtab->indir[k];
+					if(k < 0 || k >= symtab->nsym) {
+						werrstr("invalid scattered relocation: symbol reference out of range");
+						goto bad;
+					}
+					rp->sym = symtab->sym[k].sym;
+				} else {
+					werrstr("unsupported scattered relocation: reference to %s/%s", ks->segname, ks->name);
+					goto bad;
+				}
+				rp++;
+				// skip #1 of 2 rel; continue skips #2 of 2.
+				rel++;
+				j++;
+				continue;
+			}
+
+			rp->siz = rel->length;
+			rp->type = 512 + (rel->type<<1) + rel->pcrel;
+			rp->off = rel->addr;
+			
+			rp->add = e->e32(s->p+rp->off);
+			// For i386 Mach-O PC-relative, the addend is written such that
+			// it *is* the PC being subtracted.  Use that to make
+			// it match our version of PC-relative.
+			if(rel->pcrel && thechar == '8')
+				rp->add += rp->off+rp->siz;
+			if(!rel->extrn) {
+				if(rel->symnum < 1 || rel->symnum > c->seg.nsect) {
+					werrstr("invalid relocation: section reference out of range %d vs %d", rel->symnum, c->seg.nsect);
+					goto bad;
+				}
+				rp->sym = c->seg.sect[rel->symnum-1].sym;
+				if(rp->sym == nil) {
+					werrstr("invalid relocation: %s", c->seg.sect[rel->symnum-1].name);
+					goto bad;
+				}
+				// References to symbols in other sections
+				// include that information in the addend.
+				// We only care about the delta from the 
+				// section base.
+				if(thechar == '8')
+					rp->add -= c->seg.sect[rel->symnum-1].addr;
+			} else {
+				if(rel->symnum >= symtab->nsym) {
+					werrstr("invalid relocation: symbol reference out of range");
+					goto bad;
+				}
+				rp->sym = symtab->sym[rel->symnum].sym;
+			}
+			rp++;
+		}			
+		qsort(r, rp - r, sizeof r[0], rbyoff);
+		s->r = r;
+		s->nr = rp - r;
+	}
+	return;
+
+bad:
+	diag("%s: malformed mach-o file: %r", pn);
+}
diff --git a/src/cmd/ld/lib.c b/src/cmd/ld/lib.c
index 1af9f7a41..ae77247c3 100644
--- a/src/cmd/ld/lib.c
+++ b/src/cmd/ld/lib.c
@@ -1,5 +1,6 @@
-// Derived from Inferno utils/6l/obj.c
+// Derived from Inferno utils/6l/obj.c and utils/6l/span.c
 // http://code.google.com/p/inferno-os/source/browse/utils/6l/obj.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6l/span.c
 //
 //	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
 //	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
@@ -118,7 +119,7 @@ addlib(char *src, char *obj)
 	}
 
 	for(; i<histfrogp; i++) {
-		snprint(comp, sizeof comp, histfrog[i]->name+1);
+		snprint(comp, sizeof comp, "%s", histfrog[i]->name+1);
 		for(;;) {
 			p = strstr(comp, "$O");
 			if(p == 0)
@@ -146,6 +147,22 @@ addlib(char *src, char *obj)
 		strcat(name, comp);
 	}
 	cleanname(name);
+	
+	// runtime.a -> runtime
+	p = nil;
+	if(strlen(name) > 2 && name[strlen(name)-2] == '.') {
+		p = name+strlen(name)-2;
+		*p = '\0';
+	}
+	
+	// already loaded?
+	for(i=0; i<libraryp; i++)
+		if(strcmp(library[i].pkg, name) == 0)
+			return;
+	
+	// runtime -> runtime.a for search
+	if(p != nil)
+		*p = '.';
 
 	if(search) {
 		// try dot, -L "libdir", and then goroot.
@@ -159,8 +176,8 @@ addlib(char *src, char *obj)
 	cleanname(pname);
 
 	/* runtime.a -> runtime */
-	if(strlen(name) > 2 && name[strlen(name)-2] == '.')
-		name[strlen(name)-2] = '\0';
+	if(p != nil)
+		*p = '\0';
 
 	if(debug['v'])
 		Bprint(&bso, "%5.2f addlib: %s %s pulls in %s\n", cputime(), obj, src, pname);
@@ -186,9 +203,9 @@ addlibpath(char *srcref, char *objref, char *file, char *pkg)
 		if(strcmp(file, library[i].file) == 0)
 			return;
 
-	if(debug['v'])
+	if(debug['v'] > 1)
 		Bprint(&bso, "%5.2f addlibpath: srcref: %s objref: %s file: %s pkg: %s\n",
-		cputime(), srcref, objref, file, pkg);
+			cputime(), srcref, objref, file, pkg);
 
 	if(libraryp == nlibrary){
 		nlibrary = 50 + 2*libraryp;
@@ -219,8 +236,6 @@ loadlib(void)
 {
 	char pname[1024];
 	int i, found;
-	int32 h;
-	Sym *s;
 
 	found = 0;
 	for(i=0; i<nlibdir; i++) {
@@ -233,47 +248,51 @@ loadlib(void)
 			break;
 		}
 	}
-	if(!found) Bprint(&bso, "warning: unable to find runtime.a\n");
+	if(!found)
+		Bprint(&bso, "warning: unable to find runtime.a\n");
 
-loop:
-	xrefresolv = 0;
 	for(i=0; i<libraryp; i++) {
 		if(debug['v'])
 			Bprint(&bso, "%5.2f autolib: %s (from %s)\n", cputime(), library[i].file, library[i].objref);
 		objfile(library[i].file, library[i].pkg);
 	}
+}
 
-	if(xrefresolv)
-	for(h=0; h<nelem(hash); h++)
-	for(s = hash[h]; s != S; s = s->link)
-		if(s->type == SXREF)
-			goto loop;
-
+/*
+ * look for the next file in an archive.
+ * adapted from libmach.
+ */
+int
+nextar(Biobuf *bp, int off, struct ar_hdr *a)
+{
+	int r;
+	int32 arsize;
+
+	if (off&01)
+		off++;
+	Bseek(bp, off, 0);
+	r = Bread(bp, a, SAR_HDR);
+	if(r != SAR_HDR)
+		return 0;
+	if(strncmp(a->fmag, ARFMAG, sizeof(a->fmag)))
+		return -1;
+	arsize = strtol(a->size, 0, 0);
+	if (arsize&1)
+		arsize++;
+	return arsize + SAR_HDR;
 }
 
 void
 objfile(char *file, char *pkg)
 {
-	int32 off, esym, cnt, l;
-	int work;
+	int32 off, l;
 	Biobuf *f;
-	Sym *s;
 	char magbuf[SARMAG];
-	char name[100], pname[150];
+	char pname[150];
 	struct ar_hdr arhdr;
-	char *e, *start, *stop, *x;
 
 	pkg = smprint("%i", pkg);
 
-	if(file[0] == '-' && file[1] == 'l') {	// TODO: fix this
-		if(debug['9'])
-			sprint(name, "/%s/lib/lib", thestring);
-		else
-			sprint(name, "/usr/%clib/lib", thechar);
-		strcat(name, file+2);
-		strcat(name, ".a");
-		file = name;
-	}
 	if(debug['v'])
 		Bprint(&bso, "%5.2f ldobj: %s (%s)\n", cputime(), file, pkg);
 	Bflush(&bso);
@@ -291,9 +310,10 @@ objfile(char *file, char *pkg)
 		Bterm(f);
 		return;
 	}
-
-	l = Bread(f, &arhdr, SAR_HDR);
-	if(l != SAR_HDR) {
+	
+	/* skip over __.SYMDEF */
+	off = Boffset(f);
+	if((l = nextar(f, off, &arhdr)) <= 0) {
 		diag("%s: short read on archive file symbol header", file);
 		goto out;
 	}
@@ -301,88 +321,52 @@ objfile(char *file, char *pkg)
 		diag("%s: first entry not symbol header", file);
 		goto out;
 	}
-
-	esym = SARMAG + SAR_HDR + atolwhex(arhdr.size);
-	off = SARMAG + SAR_HDR;
-
-	if(debug['u']) {
-		struct ar_hdr pkghdr;
-		int n;
-
-		// Read next ar header to check for package safe bit.
-		Bseek(f, esym+(esym&1), 0);
-		l = Bread(f, &pkghdr, SAR_HDR);
-		if(l != SAR_HDR) {
-			diag("%s: short read on second archive header", file);
-			goto out;
-		}
-		if(strncmp(pkghdr.name, pkgname, strlen(pkgname))) {
-			diag("%s: second entry not package header", file);
-			goto out;
-		}
-		n = atolwhex(pkghdr.size);
-		ldpkg(f, pkg, n, file, Pkgdef);
+	off += l;
+	
+	/* skip over (or process) __.PKGDEF */
+	if((l = nextar(f, off, &arhdr)) <= 0) {
+		diag("%s: short read on archive file symbol header", file);
+		goto out;
 	}
+	if(strncmp(arhdr.name, pkgname, strlen(pkgname))) {
+		diag("%s: second entry not package header", file);
+		goto out;
+	}
+	off += l;
+
+	if(debug['u'])
+		ldpkg(f, pkg, atolwhex(arhdr.size), file, Pkgdef);
 
 	/*
-	 * just bang the whole symbol file into memory
+	 * load all the object files from the archive now.
+	 * this gives us sequential file access and keeps us
+	 * from needing to come back later to pick up more
+	 * objects.  it breaks the usual C archive model, but
+	 * this is Go, not C.  the common case in Go is that
+	 * we need to load all the objects, and then we throw away
+	 * the individual symbols that are unused.
+	 *
+	 * loading every object will also make it possible to
+	 * load foreign objects not referenced by __.SYMDEF.
 	 */
-	Bseek(f, off, 0);
-	cnt = esym - off;
-	start = mal(cnt + 10);
-	cnt = Bread(f, start, cnt);
-	if(cnt <= 0){
-		Bterm(f);
-		return;
-	}
-	stop = &start[cnt];
-	memset(stop, 0, 10);
-
-	work = 1;
-	while(work) {
-		if(debug['v'])
-			Bprint(&bso, "%5.2f library pass: %s\n", cputime(), file);
-		Bflush(&bso);
-		work = 0;
-		for(e = start; e < stop; e = strchr(e+5, 0) + 1) {
-			x = expandpkg(e+5, pkg);
-			s = lookup(x, 0);
-			if(x != e+5)
-				free(x);
-			if(s->type != SXREF)
-				continue;
-			sprint(pname, "%s(%s)", file, s->name);
-			if(debug['v'])
-				Bprint(&bso, "%5.2f library: %s\n", cputime(), pname);
-			Bflush(&bso);
-			l = e[1] & 0xff;
-			l |= (e[2] & 0xff) << 8;
-			l |= (e[3] & 0xff) << 16;
-			l |= (e[4] & 0xff) << 24;
-			Bseek(f, l, 0);
-			l = Bread(f, &arhdr, SAR_HDR);
-			if(l != SAR_HDR)
-				goto bad;
-			if(strncmp(arhdr.fmag, ARFMAG, sizeof(arhdr.fmag)))
-				goto bad;
-			l = SARNAME;
-			while(l > 0 && arhdr.name[l-1] == ' ')
-				l--;
-			sprint(pname, "%s(%.*s)", file, l, arhdr.name);
-			l = atolwhex(arhdr.size);
-			ldobj(f, pkg, l, pname, ArchiveObj);
-			if(s->type == SXREF) {
-				diag("%s: failed to load: %s", file, s->name);
-				errorexit();
-			}
-			work = 1;
-			xrefresolv = 1;
+	for(;;) {
+		l = nextar(f, off, &arhdr);
+		if(l == 0)
+			break;
+		if(l < 0) {
+			diag("%s: malformed archive", file);
+			goto out;
 		}
+		off += l;
+
+		l = SARNAME;
+		while(l > 0 && arhdr.name[l-1] == ' ')
+			l--;
+		snprint(pname, sizeof pname, "%s(%.*s)", file, utfnlen(arhdr.name, l), arhdr.name);
+		l = atolwhex(arhdr.size);
+		ldobj(f, pkg, l, pname, ArchiveObj);
 	}
-	return;
 
-bad:
-	diag("%s: bad or out of date archive", file);
 out:
 	Bterm(f);
 }
@@ -390,32 +374,38 @@ out:
 void
 ldobj(Biobuf *f, char *pkg, int64 len, char *pn, int whence)
 {
-	static int files;
-	static char **filen;
-	char **nfilen, *line;
-	int i, n, c1, c2, c3;
+	char *line;
+	int n, c1, c2, c3, c4;
+	uint32 magic;
 	vlong import0, import1, eof;
 	char src[1024];
 
 	eof = Boffset(f) + len;
 	src[0] = '\0';
 
-	// don't load individual object more than once.
-	// happens with import of .6 files because of loop in xresolv.
-	// doesn't happen with .a because SYMDEF is consulted
-	// first to decide whether each individual object file is needed.
-	for(i=0; i<files; i++)
-		if(strcmp(filen[i], pn) == 0)
-			return;
+	pn = strdup(pn);
+	
+	USED(c4);
+	USED(magic);
 
-	if((files&15) == 0){
-		nfilen = malloc((files+16)*sizeof(char*));
-		memmove(nfilen, filen, files*sizeof(char*));
-		free(filen);
-		filen = nfilen;
+	c1 = Bgetc(f);
+	c2 = Bgetc(f);
+	c3 = Bgetc(f);
+	c4 = Bgetc(f);
+	Bungetc(f);
+	Bungetc(f);
+	Bungetc(f);
+	Bungetc(f);
+	
+	magic = c1<<24 | c2<<16 | c3<<8 | c4;
+	if(magic == 0x7f454c46) {	// \x7F E L F
+		ldelf(f, pkg, len, pn);
+		return;
+	}
+	if((magic&~1) == 0xfeedface || (magic&~0x01000000) == 0xcefaedfe) {
+		ldmacho(f, pkg, len, pn);
+		return;
 	}
-	pn = strdup(pn);
-	filen[files++] = pn;
 
 	/* check the header */
 	line = Brdline(f, '\n');
@@ -478,7 +468,7 @@ lookup(char *symb, int v)
 	// not if(h < 0) h = ~h, because gcc 4.3 -O2 miscompiles it.
 	h &= 0xffffff;
 	h %= NHASH;
-	for(s = hash[h]; s != S; s = s->link)
+	for(s = hash[h]; s != S; s = s->hash)
 		if(s->version == v)
 		if(memcmp(s->name, symb, l) == 0)
 			return s;
@@ -487,14 +477,18 @@ lookup(char *symb, int v)
 	if(debug['v'] > 1)
 		Bprint(&bso, "lookup %s\n", symb);
 
+	s->dynid = -1;
+	s->plt = -1;
+	s->got = -1;
 	s->name = mal(l + 1);
 	memmove(s->name, symb, l);
 
-	s->link = hash[h];
+	s->hash = hash[h];
 	s->type = 0;
 	s->version = v;
 	s->value = 0;
 	s->sig = 0;
+	s->size = 0;
 	hash[h] = s;
 	nsymbol++;
 	return s;
@@ -607,8 +601,13 @@ nuxiinit(void)
 		if(i < 1)
 			inuxi1[i] = c;
 		inuxi4[i] = c;
-		inuxi8[i] = c;
-		inuxi8[i+4] = c+4;
+		if(c == i) {
+			inuxi8[i] = c;
+			inuxi8[i+4] = c+4;
+		} else {
+			inuxi8[i] = c+4;
+			inuxi8[i+4] = c;
+		}
 		fnuxi4[i] = c;
 		fnuxi8[i] = c;
 		fnuxi8[i+4] = c+4;
@@ -732,21 +731,6 @@ ieeedtod(Ieee *ieeep)
 }
 
 void
-undefsym(Sym *s)
-{
-	int n;
-
-	n = imports;
-	if(s->value != 0)
-		diag("value != 0 on SXREF");
-	if(n >= 1<<Rindex)
-		diag("import index %d out of range", n);
-	s->value = n<<Roffset;
-	s->type = SUNDEF;
-	imports++;
-}
-
-void
 zerosig(char *sp)
 {
 	Sym *s;
@@ -755,47 +739,6 @@ zerosig(char *sp)
 	s->sig = 0;
 }
 
-void
-readundefs(char *f, int t)
-{
-	int i, n;
-	Sym *s;
-	Biobuf *b;
-	char *l, buf[256], *fields[64];
-
-	if(f == nil)
-		return;
-	b = Bopen(f, OREAD);
-	if(b == nil){
-		diag("could not open %s: %r", f);
-		errorexit();
-	}
-	while((l = Brdline(b, '\n')) != nil){
-		n = Blinelen(b);
-		if(n >= sizeof(buf)){
-			diag("%s: line too long", f);
-			errorexit();
-		}
-		memmove(buf, l, n);
-		buf[n-1] = '\0';
-		n = getfields(buf, fields, nelem(fields), 1, " \t\r\n");
-		if(n == nelem(fields)){
-			diag("%s: bad format", f);
-			errorexit();
-		}
-		for(i = 0; i < n; i++){
-			s = lookup(fields[i], 0);
-			s->type = SXREF;
-			s->subtype = t;
-			if(t == SIMPORT)
-				nimports++;
-			else
-				nexports++;
-		}
-	}
-	Bterm(b);
-}
-
 int32
 Bget4(Biobuf *f)
 {
@@ -829,15 +772,22 @@ mal(uint32 n)
 {
 	void *v;
 
-	while(n & 7)
-		n++;
+	n = (n+7)&~7;
 	if(n > NHUNK) {
 		v = malloc(n);
+		if(v == nil) {
+			diag("out of memory");
+			errorexit();
+		}
 		memset(v, 0, n);
 		return v;
 	}
 	if(n > nhunk) {
 		hunk = malloc(NHUNK);
+		if(hunk == nil) {
+			diag("out of memory");
+			errorexit();
+		}
 		nhunk = NHUNK;
 	}
 
@@ -849,6 +799,16 @@ mal(uint32 n)
 	return v;
 }
 
+void
+unmal(void *v, uint32 n)
+{
+	n = (n+7)&~7;
+	if(hunk - n == v) {
+		hunk -= n;
+		nhunk += n;
+	}
+}
+
 // Copied from ../gc/subr.c:/^pathtoprefix; must stay in sync.
 /*
  * Convert raw string to the prefix that will be used in the symbol table.
@@ -901,3 +861,211 @@ iconv(Fmt *fp)
 	return 0;
 }
 
+void
+mangle(char *file)
+{
+	fprint(2, "%s: mangled input file\n", file);
+	errorexit();
+}
+
+Section*
+addsection(Segment *seg, char *name, int rwx)
+{
+	Section **l;
+	Section *sect;
+	
+	for(l=&seg->sect; *l; l=&(*l)->next)
+		;
+	sect = mal(sizeof *sect);
+	sect->rwx = rwx;
+	sect->name = name;
+	sect->seg = seg;
+	*l = sect;
+	return sect;
+}
+
+void
+ewrite(int fd, void *buf, int n)
+{
+	if(write(fd, buf, n) < 0) {
+		diag("write error: %r");
+		errorexit();
+	}
+}
+
+void
+pclntab(void)
+{
+	vlong oldpc;
+	Prog *p;
+	int32 oldlc, v, s;
+	Sym *sym;
+	uchar *bp;
+	
+	sym = lookup("pclntab", 0);
+	sym->type = SRODATA;
+	sym->reachable = 1;
+	if(debug['s'])
+		return;
+
+	oldpc = INITTEXT;
+	oldlc = 0;
+	for(cursym = textp; cursym != nil; cursym = cursym->next) {
+		for(p = cursym->text; p != P; p = p->link) {
+			if(p->line == oldlc || p->as == ATEXT || p->as == ANOP) {
+				if(debug['O'])
+					Bprint(&bso, "%6llux %P\n",
+						(vlong)p->pc, p);
+				continue;
+			}
+			if(debug['O'])
+				Bprint(&bso, "\t\t%6d", lcsize);
+			v = (p->pc - oldpc) / MINLC;
+			while(v) {
+				s = 127;
+				if(v < 127)
+					s = v;
+				symgrow(sym, lcsize+1);
+				bp = sym->p + lcsize;
+				*bp = s+128;	/* 129-255 +pc */
+				if(debug['O'])
+					Bprint(&bso, " pc+%d*%d(%d)", s, MINLC, s+128);
+				v -= s;
+				lcsize++;
+			}
+			s = p->line - oldlc;
+			oldlc = p->line;
+			oldpc = p->pc + MINLC;
+			if(s > 64 || s < -64) {
+				symgrow(sym, lcsize+5);
+				bp = sym->p + lcsize;
+				*bp++ = 0;	/* 0 vv +lc */
+				*bp++ = s>>24;
+				*bp++ = s>>16;
+				*bp++ = s>>8;
+				*bp = s;
+				if(debug['O']) {
+					if(s > 0)
+						Bprint(&bso, " lc+%d(%d,%d)\n",
+							s, 0, s);
+					else
+						Bprint(&bso, " lc%d(%d,%d)\n",
+							s, 0, s);
+					Bprint(&bso, "%6llux %P\n",
+						(vlong)p->pc, p);
+				}
+				lcsize += 5;
+				continue;
+			}
+			symgrow(sym, lcsize+1);
+			bp = sym->p + lcsize;
+			if(s > 0) {
+				*bp = 0+s;	/* 1-64 +lc */
+				if(debug['O']) {
+					Bprint(&bso, " lc+%d(%d)\n", s, 0+s);
+					Bprint(&bso, "%6llux %P\n",
+						(vlong)p->pc, p);
+				}
+			} else {
+				*bp = 64-s;	/* 65-128 -lc */
+				if(debug['O']) {
+					Bprint(&bso, " lc%d(%d)\n", s, 64-s);
+					Bprint(&bso, "%6llux %P\n",
+						(vlong)p->pc, p);
+				}
+			}
+			lcsize++;
+		}
+	}
+	if(lcsize & 1) {
+		symgrow(sym, lcsize+1);
+		sym->p[lcsize] = 129;
+		lcsize++;
+	}
+	sym->size = lcsize;
+	lcsize = 0;
+
+	if(debug['v'] || debug['O'])
+		Bprint(&bso, "lcsize = %d\n", lcsize);
+	Bflush(&bso);
+}
+
+#define	LOG	5
+void
+mkfwd(void)
+{
+	Prog *p;
+	int i;
+	int32 dwn[LOG], cnt[LOG];
+	Prog *lst[LOG], *last;
+
+	for(i=0; i<LOG; i++) {
+		if(i == 0)
+			cnt[i] = 1;
+		else
+			cnt[i] = LOG * cnt[i-1];
+		dwn[i] = 1;
+		lst[i] = P;
+	}
+	i = 0;
+	last = nil;
+	for(cursym = textp; cursym != nil; cursym = cursym->next) {
+		for(p = cursym->text; p != P; p = p->link) {
+			if(p->link == P) {
+				if(cursym->next)
+					p->forwd = cursym->next->text;
+				break;
+			}
+			i--;
+			if(i < 0)
+				i = LOG-1;
+			p->forwd = P;
+			dwn[i]--;
+			if(dwn[i] <= 0) {
+				dwn[i] = cnt[i];
+				if(lst[i] != P)
+					lst[i]->forwd = p;
+				lst[i] = p;
+			}
+		}
+	}
+}
+
+uint16
+le16(uchar *b)
+{
+	return b[0] | b[1]<<8;
+}
+
+uint32
+le32(uchar *b)
+{
+	return b[0] | b[1]<<8 | b[2]<<16 | b[3]<<24;
+}
+
+uint64
+le64(uchar *b)
+{
+	return le32(b) | (uint64)le32(b+4)<<32;
+}
+
+uint16
+be16(uchar *b)
+{
+	return b[0]<<8 | b[1];
+}
+
+uint32
+be32(uchar *b)
+{
+	return b[0]<<24 | b[1]<<16 | b[2]<<8 | b[3];
+}
+
+uint64
+be64(uchar *b)
+{
+	return (uvlong)be32(b)<<32 | be32(b+4);
+}
+
+Endian be = { be16, be32, be64 };
+Endian le = { le16, le32, le64 };
diff --git a/src/cmd/ld/lib.h b/src/cmd/ld/lib.h
index 652d845fb..bcf297116 100644
--- a/src/cmd/ld/lib.h
+++ b/src/cmd/ld/lib.h
@@ -40,6 +40,34 @@ struct Library
 	char *pkg;	// import path
 };
 
+// Terrible but standard terminology.
+// A segment describes a block of file to load into memory.
+// A section further describes the pieces of that block for
+// use in debuggers and such.
+
+typedef struct Segment Segment;
+typedef struct Section Section;
+
+struct Segment
+{
+	uchar	rwx;		// permission as usual unix bits (5 = r-x etc)
+	uvlong	vaddr;	// virtual address
+	uvlong	len;		// length in memory
+	uvlong	fileoff;	// file offset
+	uvlong	filelen;	// length on disk
+	Section*	sect;
+};
+
+struct Section
+{
+	uchar	rwx;
+	char	*name;
+	uvlong	vaddr;
+	uvlong	len;
+	Section	*next;	// in segment list
+	Segment	*seg;
+};
+
 extern	char	symname[];
 extern	char	*libdir[];
 extern	int	nlibdir;
@@ -64,11 +92,18 @@ EXTERN	uchar	inuxi8[8];
 EXTERN	char*	outfile;
 EXTERN	int32	nsymbol;
 EXTERN	char*	thestring;
+EXTERN	int	ndynexp;
+
+EXTERN	Segment	segtext;
+EXTERN	Segment	segdata;
+EXTERN	Segment	segsym;
 
 void	addlib(char *src, char *obj);
 void	addlibpath(char *srcref, char *objref, char *file, char *pkg);
+Section*	addsection(Segment*, char*, int);
 void	copyhistfrog(char *buf, int nbuf);
 void	addhist(int32 line, int type);
+void	asmlc(void);
 void	histtoauto(void);
 void	collapsefrog(Sym *s);
 Sym*	lookup(char *symb, int v);
@@ -83,20 +118,82 @@ void	readundefs(char *f, int t);
 int32	Bget4(Biobuf *f);
 void	loadlib(void);
 void	errorexit(void);
+void	mangle(char*);
 void	objfile(char *file, char *pkg);
 void	libinit(void);
+void	pclntab(void);
+void	symtab(void);
 void	Lflag(char *arg);
 void	usage(void);
+void	adddynrel(Sym*, Reloc*);
 void	ldobj1(Biobuf *f, char*, int64 len, char *pn);
 void	ldobj(Biobuf*, char*, int64, char*, int);
+void	ldelf(Biobuf*, char*, int64, char*);
+void	ldmacho(Biobuf*, char*, int64, char*);
 void	ldpkg(Biobuf*, char*, int64, char*, int);
 void	mark(Sym *s);
+void	mkfwd(void);
 char*	expandpkg(char*, char*);
 void	deadcode(void);
+void	ewrite(int, void*, int);
+Reloc*	addrel(Sym*);
+void	codeblk(int32, int32);
+void	datblk(int32, int32);
+Sym*	datsort(Sym*);
+void	reloc(void);
+void	relocsym(Sym*);
+void	savedata(Sym*, Prog*);
+void	symgrow(Sym*, int32);
+vlong	addstring(Sym*, char*);
+vlong	adduint32(Sym*, uint32);
+vlong	adduint64(Sym*, uint64);
+vlong	addaddr(Sym*, Sym*);
+vlong	addaddrplus(Sym*, Sym*, int32);
+vlong	addpcrelplus(Sym*, Sym*, int32);
+vlong	addsize(Sym*, Sym*);
+vlong	adduint8(Sym*, uint8);
+vlong	adduint16(Sym*, uint16);
+void	asmsym(void);
+void	asmelfsym64(void);
+void	strnput(char*, int);
+void	dodata(void);
+void	address(void);
+void	textaddress(void);
+void	genasmsym(void (*put)(Sym*, char*, int, vlong, vlong, int, Sym*));
+vlong	datoff(vlong);
+void	adddynlib(char*);
+int	archreloc(Reloc*, Sym*, vlong*);
+void	adddynsym(Sym*);
+void	addexport(void);
 
 int	pathchar(void);
 void*	mal(uint32);
+void	unmal(void*, uint32);
 void	mywhatsys(void);
+int	rbyoff(const void*, const void*);
+
+uint16	le16(uchar*);
+uint32	le32(uchar*);
+uint64	le64(uchar*);
+uint16	be16(uchar*);
+uint32	be32(uchar*);
+uint64	be64(uchar*);
+
+typedef struct Endian Endian;
+struct Endian
+{
+	uint16	(*e16)(uchar*);
+	uint32	(*e32)(uchar*);
+	uint64	(*e64)(uchar*);
+};
+
+extern Endian be, le;
+
+// relocation size bits
+enum {
+	Rbig = 128,
+	Rlittle = 64,
+};
 
 /* set by call to mywhatsys() */
 extern	char*	goroot;
diff --git a/src/cmd/ld/macho.c b/src/cmd/ld/macho.c
index 24400cf14..402e0ec63 100644
--- a/src/cmd/ld/macho.c
+++ b/src/cmd/ld/macho.c
@@ -6,6 +6,7 @@
 // http://developer.apple.com/mac/library/DOCUMENTATION/DeveloperTools/Conceptual/MachORuntime/Reference/reference.html
 
 #include "l.h"
+#include "../ld/dwarf.h"
 #include "../ld/lib.h"
 #include "../ld/macho.h"
 
@@ -46,6 +47,10 @@ newMachoLoad(uint32 type, uint32 ndata)
 		diag("too many loads");
 		errorexit();
 	}
+	
+	if(macho64 && (ndata & 1))
+		ndata++;
+	
 	l = &load[nload++];
 	l->type = type;
 	l->ndata = ndata;
@@ -97,22 +102,6 @@ newMachoDebug(void)
 
 // Generic linking code.
 
-static uchar *linkdata;
-static uint32 nlinkdata;
-static uint32 mlinkdata;
-
-static uchar *strtab;
-static uint32 nstrtab;
-static uint32 mstrtab;
-
-struct	Expsym
-{
-	int	off;
-	Sym*	s;
-} *expsym;
-static int nexpsym;
-static int nimpsym;
-
 static char **dylib;
 static int ndylib;
 
@@ -129,7 +118,7 @@ machowrite(void)
 	MachoDebug *d;
 	MachoLoad *l;
 
-	o1 = Boffset(&bso);
+	o1 = cpos();
 
 	loadsize = 4*4*ndebug;
 	for(i=0; i<nload; i++)
@@ -194,8 +183,8 @@ machowrite(void)
 				LPUT(t->reloc);
 				LPUT(t->nreloc);
 				LPUT(t->flag);
-				LPUT(0);	/* reserved */
-				LPUT(0);	/* reserved */
+				LPUT(t->res1);	/* reserved */
+				LPUT(t->res2);	/* reserved */
 				LPUT(0);	/* reserved */
 			} else {
 				strnput(t->name, 16);
@@ -207,8 +196,8 @@ machowrite(void)
 				LPUT(t->reloc);
 				LPUT(t->nreloc);
 				LPUT(t->flag);
-				LPUT(0);	/* reserved */
-				LPUT(0);	/* reserved */
+				LPUT(t->res1);	/* reserved */
+				LPUT(t->res2);	/* reserved */
 			}
 		}
 	}
@@ -229,224 +218,71 @@ machowrite(void)
 		LPUT(d->filesize);
 	}
 
-	return Boffset(&bso) - o1;
-}
-
-static void*
-grow(uchar **dat, uint32 *ndat, uint32 *mdat, uint32 n)
-{
-	uchar *p;
-	uint32 old;
-
-	if(*ndat+n > *mdat) {
-		old = *mdat;
-		*mdat = (*ndat+n)*2 + 128;
-		*dat = realloc(*dat, *mdat);
-		if(*dat == 0) {
-			diag("out of memory");
-			errorexit();
-		}
-		memset(*dat+old, 0, *mdat-old);
-	}
-	p = *dat + *ndat;
-	*ndat += n;
-	return p;
-}
-
-static int
-needlib(char *name)
-{
-	char *p;
-	Sym *s;
-
-	/* reuse hash code in symbol table */
-	p = smprint(".machoload.%s", name);
-	s = lookup(p, 0);
-	if(s->type == 0) {
-		s->type = 100;	// avoid SDATA, etc.
-		return 1;
-	}
-	return 0;
+	return cpos() - o1;
 }
 
 void
 domacho(void)
 {
-	int h, ptrsize, t;
-	char *p;
-	uchar *dat;
-	uint32 x;
 	Sym *s;
-	Sym **impsym;
 
-	ptrsize = 4;
-	if(macho64)
-		ptrsize = 8;
+	if(debug['d'])
+		return;
 
 	// empirically, string table must begin with " \x00".
-	if(!debug['d'])
-		*(char*)grow(&strtab, &nstrtab, &mstrtab, 2) = ' ';
-
-	impsym = nil;
-	for(h=0; h<NHASH; h++) {
-		for(s=hash[h]; s!=S; s=s->link) {
-			if(!s->reachable || (s->type != STEXT && s->type != SDATA && s->type != SBSS) || s->dynimpname == nil)
-				continue;
-			if(debug['d']) {
-				diag("cannot use dynamic loading and -d");
-				errorexit();
-			}
-			if(!s->dynexport) {
-				if(nimpsym%32 == 0) {
-					impsym = realloc(impsym, (nimpsym+32)*sizeof impsym[0]);
-					if(impsym == nil) {
-						diag("out of memory");
-						errorexit();
-					}
-				}
-				impsym[nimpsym++] = s;
-				continue;
-			}
-
-			/* symbol table entry - darwin still puts _ prefixes on all C symbols */
-			x = nstrtab;
-			p = grow(&strtab, &nstrtab, &mstrtab, 1+strlen(s->dynimpname)+1);
-			*p++ = '_';
-			strcpy(p, s->dynimpname);
-
-			dat = grow(&linkdata, &nlinkdata, &mlinkdata, 8+ptrsize);
-			dat[0] = x;
-			dat[1] = x>>8;
-			dat[2] = x>>16;
-			dat[3] = x>>24;
-
-			dat[4] = 0x0f;	// type: N_SECT | N_EXT - external, defined in sect
-			switch(s->type) {
-			default:
-			case STEXT:
-				t = 1;
-				break;
-			case SDATA:
-				t = 2;
-				break;
-			case SBSS:
-				t = 4;
-				break;
-			}
-			dat[5] = t;	// sect: section number
-
-			if (nexpsym%32 == 0) {
-				expsym = realloc(expsym, (nexpsym+32)*sizeof expsym[0]);
-				if (expsym == nil) {
-					diag("out of memory");
-					errorexit();
-				}
-			}
-			expsym[nexpsym].off = nlinkdata - ptrsize;
-			expsym[nexpsym++].s = s;
-		}
-	}
-
-	for(h=0; h<nimpsym; h++) {
-		s = impsym[h];
-		s->type = SMACHO;
-		s->value = (nexpsym+h) * ptrsize;
-
-		/* symbol table entry - darwin still puts _ prefixes on all C symbols */
-		x = nstrtab;
-		p = grow(&strtab, &nstrtab, &mstrtab, 1+strlen(s->dynimpname)+1);
-		*p++ = '_';
-		strcpy(p, s->dynimpname);
-
-		dat = grow(&linkdata, &nlinkdata, &mlinkdata, 8+ptrsize);
-		dat[0] = x;
-		dat[1] = x>>8;
-		dat[2] = x>>16;
-		dat[3] = x>>24;
-
-		dat[4] = 0x01;	// type: N_EXT - external symbol
-
-		if(needlib(s->dynimplib)) {
-			if(ndylib%32 == 0) {
-				dylib = realloc(dylib, (ndylib+32)*sizeof dylib[0]);
-				if(dylib == nil) {
-					diag("out of memory");
-					errorexit();
-				}
-			}
-			dylib[ndylib++] = s->dynimplib;
-		}
-	}
-	free(impsym);
-
-	/*
-	 * list of symbol table indexes.
-	 * we don't take advantage of the opportunity
-	 * to order the symbol table differently from
-	 * this list, so it is boring: 0 1 2 3 4 ...
-	 */
-	for(x=0; x<nexpsym+nimpsym; x++) {
-		dat = grow(&linkdata, &nlinkdata, &mlinkdata, 4);
-		dat[0] = x;
-		dat[1] = x>>8;
-		dat[2] = x>>16;
-		dat[3] = x>>24;
-	}
-
-	dynptrsize = (nexpsym+nimpsym) * ptrsize;
+	s = lookup(".dynstr", 0);
+	s->type = SMACHODYNSTR;
+	s->reachable = 1;
+	adduint8(s, ' ');
+	adduint8(s, '\0');
+	
+	s = lookup(".dynsym", 0);
+	s->type = SMACHODYNSYM;
+	s->reachable = 1;
+	
+	s = lookup(".plt", 0);	// will be __symbol_stub
+	s->type = SMACHOPLT;
+	s->reachable = 1;
+	
+	s = lookup(".got", 0);	// will be __nl_symbol_ptr
+	s->type = SMACHOGOT;
+	s->reachable = 1;
+	
+	s = lookup(".linkedit.plt", 0);	// indirect table for .plt
+	s->type = SMACHOINDIRECTPLT;
+	s->reachable = 1;
+	
+	s = lookup(".linkedit.got", 0);	// indirect table for .got
+	s->type = SMACHOINDIRECTGOT;
+	s->reachable = 1;
 }
 
-vlong
-domacholink(void)
+void
+machoadddynlib(char *lib)
 {
-	int i;
-	uchar *p;
-	Sym *s;
-	uint64 val;
-
-	linkoff = 0;
-	if(nlinkdata > 0) {
-		linkoff = rnd(HEADR+textsize, INITRND) + rnd(datsize, INITRND);
-		seek(cout, linkoff, 0);
-
-		for(i = 0; i<nexpsym; ++i) {
-			s = expsym[i].s;
-			val = s->value;
-			if(s->type == SUNDEF)
-				diag("export of undefined symbol %s", s->name);
-			if (s->type != STEXT)
-				val += INITDAT;
-			p = linkdata+expsym[i].off;
-			p[0] = val;
-			p[1] = val >> 8;
-			p[2] = val >> 16;
-			p[3] = val >> 24;
-			if (macho64) {
-				p[4] = val >> 32;
-				p[5] = val >> 40;
-				p[6] = val >> 48;
-				p[7] = val >> 56;
-			}
+	if(ndylib%32 == 0) {
+		dylib = realloc(dylib, (ndylib+32)*sizeof dylib[0]);
+		if(dylib == nil) {
+			diag("out of memory");
+			errorexit();
 		}
-
-		write(cout, linkdata, nlinkdata);
-		write(cout, strtab, nstrtab);
 	}
-	return rnd(nlinkdata+nstrtab, INITRND);
+	dylib[ndylib++] = lib;
 }
 
 void
-asmbmacho(vlong symdatva, vlong symo)
+asmbmacho(void)
 {
 	vlong v, w;
 	vlong va;
-	int a, i, ptrsize;
+	int a, i;
 	char *pkgroot;
 	MachoHdr *mh;
 	MachoSect *msect;
 	MachoSeg *ms;
 	MachoDebug *md;
 	MachoLoad *ml;
+	Sym *s;
 
 	/* apple MACH */
 	va = INITTEXT - HEADR;
@@ -458,12 +294,10 @@ asmbmacho(vlong symdatva, vlong symo)
 	case '6':
 		mh->cpu = MACHO_CPU_AMD64;
 		mh->subcpu = MACHO_SUBCPU_X86;
-		ptrsize = 8;
 		break;
 	case '8':
 		mh->cpu = MACHO_CPU_386;
 		mh->subcpu = MACHO_SUBCPU_X86;
-		ptrsize = 4;
 		break;
 	}
 
@@ -472,8 +306,8 @@ asmbmacho(vlong symdatva, vlong symo)
 	ms->vsize = va;
 
 	/* text */
-	v = rnd(HEADR+textsize, INITRND);
-	ms = newMachoSeg("__TEXT", 1);
+	v = rnd(HEADR+segtext.len, INITRND);
+	ms = newMachoSeg("__TEXT", 2);
 	ms->vaddr = va;
 	ms->vsize = v;
 	ms->filesize = v;
@@ -482,45 +316,50 @@ asmbmacho(vlong symdatva, vlong symo)
 
 	msect = newMachoSect(ms, "__text");
 	msect->addr = INITTEXT;
-	msect->size = textsize;
+	msect->size = segtext.sect->len;
 	msect->off = INITTEXT - va;
 	msect->flag = 0x400;	/* flag - some instructions */
+	
+	s = lookup(".plt", 0);
+	if(s->size > 0) {
+		msect = newMachoSect(ms, "__symbol_stub1");
+		msect->addr = symaddr(s);
+		msect->size = s->size;
+		msect->off = ms->fileoffset + msect->addr - ms->vaddr;
+		msect->flag = 0x80000408;	/* flag */
+		msect->res1 = 0;	/* index into indirect symbol table */
+		msect->res2 = 6;	/* size of stubs */
+	}
 
 	/* data */
-	w = datsize+dynptrsize+bsssize;
-	ms = newMachoSeg("__DATA", 2+(dynptrsize>0));
+	w = segdata.len;
+	ms = newMachoSeg("__DATA", 3);
 	ms->vaddr = va+v;
 	ms->vsize = w;
 	ms->fileoffset = v;
-	ms->filesize = datsize;
+	ms->filesize = segdata.filelen;
 	ms->prot1 = 7;
 	ms->prot2 = 3;
 
 	msect = newMachoSect(ms, "__data");
 	msect->addr = va+v;
-	msect->size = datsize;
+	msect->size = symaddr(lookup(".got", 0)) - msect->addr;
 	msect->off = v;
 
-	if(dynptrsize > 0) {
+	s = lookup(".got", 0);
+	if(s->size > 0) {
 		msect = newMachoSect(ms, "__nl_symbol_ptr");
-		msect->addr = va+v+datsize;
-		msect->size = dynptrsize;
+		msect->addr = symaddr(s);
+		msect->size = s->size;
+		msect->off = datoff(msect->addr);
 		msect->align = 2;
 		msect->flag = 6;	/* section with nonlazy symbol pointers */
-		/*
-		 * The reserved1 field is supposed to be the index of
-		 * the first entry in the list of symbol table indexes
-		 * in isymtab for the symbols we need.  We only use
-		 * pointers, so we need the entire list, so the index
-		 * here should be 0, which luckily is what the Mach-O
-		 * writing code emits by default for this not really reserved field.
-		msect->reserved1 = 0; - first indirect symbol table entry we need
-		 */
+		msect->res1 = lookup(".linkedit.plt", 0)->size / 4;	/* offset into indirect symbol table */
 	}
 
 	msect = newMachoSect(ms, "__bss");
-	msect->addr = va+v+datsize+dynptrsize;
-	msect->size = bsssize;
+	msect->addr = va+v+segdata.filelen;
+	msect->size = segdata.len - segdata.filelen;
 	msect->flag = 1;	/* flag - zero fill */
 
 	switch(thechar) {
@@ -532,7 +371,7 @@ asmbmacho(vlong symdatva, vlong symo)
 		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;
+		ml->data[2+32+1] = entryvalue()>>16>>16;	// hide >>32 for 8l
 		break;
 	case '8':
 		ml = newMachoLoad(5, 16+2);	/* unix thread */
@@ -543,39 +382,43 @@ asmbmacho(vlong symdatva, vlong symo)
 	}
 
 	if(!debug['d']) {
-		int nsym;
+		Sym *s1, *s2, *s3, *s4;
 
-		nsym = dynptrsize/ptrsize;
+		// must match domacholink below
+		s1 = lookup(".dynsym", 0);
+		s2 = lookup(".dynstr", 0);
+		s3 = lookup(".linkedit.plt", 0);
+		s4 = lookup(".linkedit.got", 0);
 
 		ms = newMachoSeg("__LINKEDIT", 0);
-		ms->vaddr = va+v+rnd(datsize+dynptrsize+bsssize, INITRND);
-		ms->vsize = nlinkdata+nstrtab;
+		ms->vaddr = va+v+rnd(segdata.len, INITRND);
+		ms->vsize = s1->size + s2->size + s3->size + s4->size;
 		ms->fileoffset = linkoff;
-		ms->filesize = nlinkdata+nstrtab;
+		ms->filesize = ms->vsize;
 		ms->prot1 = 7;
 		ms->prot2 = 3;
 
 		ml = newMachoLoad(2, 4);	/* LC_SYMTAB */
 		ml->data[0] = linkoff;	/* symoff */
-		ml->data[1] = nsym;	/* nsyms */
-		ml->data[2] = linkoff + nlinkdata;	/* stroff */
-		ml->data[3] = nstrtab;	/* strsize */
+		ml->data[1] = s1->size / (macho64 ? 16 : 12);	/* nsyms */
+		ml->data[2] = linkoff + s1->size;	/* stroff */
+		ml->data[3] = s2->size;	/* strsize */
 
 		ml = newMachoLoad(11, 18);	/* LC_DYSYMTAB */
 		ml->data[0] = 0;	/* ilocalsym */
 		ml->data[1] = 0;	/* nlocalsym */
 		ml->data[2] = 0;	/* iextdefsym */
-		ml->data[3] = nexpsym;	/* nextdefsym */
-		ml->data[4] = nexpsym;	/* iundefsym */
-		ml->data[5] = nimpsym;	/* nundefsym */
+		ml->data[3] = ndynexp;	/* nextdefsym */
+		ml->data[4] = ndynexp;	/* iundefsym */
+		ml->data[5] = (s1->size / (macho64 ? 16 : 12)) - ndynexp;	/* nundefsym */
 		ml->data[6] = 0;	/* tocoffset */
 		ml->data[7] = 0;	/* ntoc */
 		ml->data[8] = 0;	/* modtaboff */
 		ml->data[9] = 0;	/* nmodtab */
 		ml->data[10] = 0;	/* extrefsymoff */
 		ml->data[11] = 0;	/* nextrefsyms */
-		ml->data[12] = linkoff + nlinkdata - nsym*4;	/* indirectsymoff */
-		ml->data[13] = nsym;	/* nindirectsyms */
+		ml->data[12] = linkoff + s1->size + s2->size;	/* indirectsymoff */
+		ml->data[13] = (s3->size + s4->size) / 4;	/* nindirectsyms */
 		ml->data[14] = 0;	/* extreloff */
 		ml->data[15] = 0;	/* nextrel */
 		ml->data[16] = 0;	/* locreloff */
@@ -602,24 +445,53 @@ asmbmacho(vlong symdatva, vlong symo)
 	}
 
 	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;
+		Sym *s;
 
 		md = newMachoDebug();
-		md->fileoffset = symo+8;
-		md->filesize = symsize;
+		s = lookup("symtab", 0);
+		md->fileoffset = datoff(s->value);
+		md->filesize = s->size;
 
 		md = newMachoDebug();
-		md->fileoffset = symo+8+symsize;
-		md->filesize = lcsize;
+		s = lookup("pclntab", 0);
+		md->fileoffset = datoff(s->value);
+		md->filesize = s->size;
+
+		dwarfaddmachoheaders();
 	}
 
 	a = machowrite();
 	if(a > MACHORESERVE)
 		diag("MACHORESERVE too small: %d > %d", a, MACHORESERVE);
 }
+
+vlong
+domacholink(void)
+{
+	int size;
+	Sym *s1, *s2, *s3, *s4;
+
+	// write data that will be linkedit section
+	s1 = lookup(".dynsym", 0);
+	relocsym(s1);
+	s2 = lookup(".dynstr", 0);
+	s3 = lookup(".linkedit.plt", 0);
+	s4 = lookup(".linkedit.got", 0);
+
+	while(s2->size%4)
+		adduint8(s2, 0);
+	
+	size = s1->size + s2->size + s3->size + s4->size;
+
+	if(size > 0) {
+		linkoff = rnd(HEADR+segtext.len, INITRND) + rnd(segdata.filelen, INITRND);
+		seek(cout, linkoff, 0);
+
+		ewrite(cout, s1->p, s1->size);
+		ewrite(cout, s2->p, s2->size);
+		ewrite(cout, s3->p, s3->size);
+		ewrite(cout, s4->p, s4->size);
+	}
+
+	return rnd(size, INITRND);
+}
diff --git a/src/cmd/ld/macho.h b/src/cmd/ld/macho.h
index a96b2a383..4cc7edc80 100644
--- a/src/cmd/ld/macho.h
+++ b/src/cmd/ld/macho.h
@@ -18,6 +18,8 @@ struct MachoSect {
 	uint32	reloc;
 	uint32	nreloc;
 	uint32	flag;
+	uint32	res1;
+	uint32	res2;
 };
 
 typedef struct MachoSeg MachoSeg;
@@ -70,8 +72,23 @@ enum {
 
 	MACHO32SYMSIZE = 12,
 	MACHO64SYMSIZE = 16,
+	
+	MACHO_X86_64_RELOC_UNSIGNED = 0,
+	MACHO_X86_64_RELOC_SIGNED = 1,
+	MACHO_X86_64_RELOC_BRANCH = 2,
+	MACHO_X86_64_RELOC_GOT_LOAD = 3,
+	MACHO_X86_64_RELOC_GOT = 4,
+	MACHO_X86_64_RELOC_SUBTRACTOR = 5,
+	MACHO_X86_64_RELOC_SIGNED_1 = 6,
+	MACHO_X86_64_RELOC_SIGNED_2 = 7,
+	MACHO_X86_64_RELOC_SIGNED_4 = 8,
+	
+	MACHO_GENERIC_RELOC_VANILLA = 0,
+	
+	MACHO_FAKE_GOTPCREL = 100,
 };
 
 void	domacho(void);
 vlong	domacholink(void);
-void	asmbmacho(vlong, vlong);
+void	asmbmacho(void);
+void	machoadddynlib(char*);
diff --git a/src/cmd/ld/pe.c b/src/cmd/ld/pe.c
index d3439abfb..82c6941f2 100644
--- a/src/cmd/ld/pe.c
+++ b/src/cmd/ld/pe.c
@@ -33,18 +33,39 @@ static char dosstub[] =
 	0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 };
 
+int32 PESECTHEADR;
+int32 PEFILEHEADR;
+
 static int pe64;
 static int nsect;
-static int sect_virt_begin;
-static int sect_raw_begin = PERESERVE;
+static int nextsectoff;
+static int nextfileoff;
 
 static IMAGE_FILE_HEADER fh;
 static IMAGE_OPTIONAL_HEADER oh;
 static IMAGE_SECTION_HEADER sh[16];
-static IMAGE_SECTION_HEADER *textsect, *datsect, *bsssect;
+
+typedef struct Imp Imp;
+struct Imp {
+	Sym* s;
+	long va;
+	long vb;
+	Imp* next;
+};
+
+typedef struct Dll Dll;
+struct Dll {
+	char* name;
+	int count;
+	Imp* ms;
+	Dll* next;
+};
+
+static Dll* dr;
+static int ndll, nimp, nsize;
 
 static IMAGE_SECTION_HEADER*
-new_section(char *name, int size, int noraw)
+addpesection(char *name, int sectsize, int filesize, Segment *s)
 {
 	IMAGE_SECTION_HEADER *h;
 
@@ -54,15 +75,23 @@ new_section(char *name, int size, int noraw)
 	}
 	h = &sh[nsect++];
 	strncpy((char*)h->Name, name, sizeof(h->Name));
-	h->VirtualSize = size;
-	if(!sect_virt_begin)
-		sect_virt_begin = 0x1000;
-	h->VirtualAddress = sect_virt_begin;
-	sect_virt_begin = rnd(sect_virt_begin+size, 0x1000);
-	if(!noraw) {
-		h->SizeOfRawData = rnd(size, PEALIGN);
-		h->PointerToRawData = sect_raw_begin;
-		sect_raw_begin += h->SizeOfRawData;
+	h->VirtualSize = sectsize;
+	h->VirtualAddress = nextsectoff;
+	nextsectoff = rnd(nextsectoff+sectsize, PESECTALIGN);
+	h->PointerToRawData = nextfileoff;
+	if(filesize > 0) {
+		h->SizeOfRawData = rnd(filesize, PEFILEALIGN);
+		nextfileoff += h->SizeOfRawData;
+	}
+	if(s) {
+		if(s->vaddr-PEBASE != h->VirtualAddress) {
+			diag("%s.VirtualAddress = %#llux, want %#llux", name, (vlong)h->VirtualAddress, (vlong)(s->vaddr-PEBASE));
+			errorexit();
+		}
+		if(s->fileoff != h->PointerToRawData) {
+			diag("%s.PointerToRawData = %#llux, want %#llux", name, (vlong)h->PointerToRawData, (vlong)(s->fileoff));
+			errorexit();
+		}
 	}
 	return h;
 }
@@ -79,6 +108,11 @@ peinit(void)
 	default:
 		break;
 	}
+
+	PEFILEHEADR = rnd(sizeof(dosstub)+sizeof(fh)+sizeof(oh)+sizeof(sh), PEFILEALIGN);
+	PESECTHEADR = rnd(PEFILEHEADR, PESECTALIGN);
+	nextsectoff = PESECTHEADR;
+	nextfileoff = PEFILEHEADR;
 }
 
 static void
@@ -86,7 +120,8 @@ pewrite(void)
 {
 	int i, j;
 
-	write(cout, dosstub, sizeof dosstub);
+	seek(cout, 0, 0);
+	ewrite(cout, dosstub, sizeof dosstub);
 	strnput("PE", 4);
 
 	for (i=0; i<sizeof(fh); i++)
@@ -98,24 +133,6 @@ pewrite(void)
 			cput(((char*)&sh[i])[j]);
 }
 
-void
-dope(void)
-{
-	textsect = new_section(".text", textsize, 0);
-	textsect->Characteristics = IMAGE_SCN_CNT_CODE|
-		IMAGE_SCN_CNT_INITIALIZED_DATA|
-		IMAGE_SCN_MEM_EXECUTE|IMAGE_SCN_MEM_READ;
-
-	datsect = new_section(".data", datsize, 0);
-	datsect->Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA|
-		IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
-	INITDAT = PEBASE+datsect->VirtualAddress;
-
-	bsssect = new_section(".bss", bsssize, 1);
-	bsssect->Characteristics = IMAGE_SCN_CNT_UNINITIALIZED_DATA|
-		IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
-}
-
 static void
 strput(char *s)
 {
@@ -124,73 +141,167 @@ strput(char *s)
 	cput('\0');
 }
 
-static void
-add_import_table(void)
+static Dll* 
+initdynimport(void)
 {
-	IMAGE_IMPORT_DESCRIPTOR ds[2], *d;
-	char *dllname = "kernel32.dll";
-	struct {
-		char *name;
-		uint32 thunk;
-	} *f, fs[] = {
-		{ "GetProcAddress", 0 },
-		{ "LoadLibraryExA", 0 },
-		{ 0, 0 }
-	};
-
-	uint32 size = 0;
-	memset(ds, 0, sizeof(ds));
-	size += sizeof(ds);
-	ds[0].Name = size;
-	size += strlen(dllname) + 1;
-	for(f=fs; f->name; f++) {
-		f->thunk = size;
-		size += sizeof(uint16) + strlen(f->name) + 1;
+	Imp *m;
+	Dll *d;
+	Sym *s;
+	int i;
+	Sym *dynamic;
+
+	dr = nil;
+	ndll = 0;
+	nimp = 0;
+	nsize = 0;
+	
+	for(i=0; i<NHASH; i++)
+	for(s = hash[i]; s != S; s = s->hash) {
+		if(!s->reachable || !s->dynimpname)
+			continue;
+		nimp++;
+		for(d = dr; d != nil; d = d->next) {
+			if(strcmp(d->name,s->dynimplib) == 0) {
+				m = mal(sizeof *m);
+				m->s = s;
+				m->next = d->ms;
+				d->ms = m;
+				d->count++;
+				nsize += strlen(s->dynimpname)+2+1;
+				break;
+			}
+		}
+		if(d == nil) {
+			d = mal(sizeof *d);
+			d->name = s->dynimplib;
+			d->count = 1;
+			d->next = dr;
+			dr = d;
+			m = mal(sizeof *m);
+			m->s = s;
+			m->next = 0;
+			d->ms = m;
+			ndll++;
+			nsize += strlen(s->dynimpname)+2+1;
+			nsize += strlen(s->dynimplib)+1;
+		}
+	}
+	
+	nsize += 20*ndll + 20;
+	nsize += 4*nimp + 4*ndll;
+	
+	dynamic = lookup(".windynamic", 0);
+	dynamic->reachable = 1;
+	dynamic->type = SWINDOWS;
+	for(d = dr; d != nil; d = d->next) {
+		for(m = d->ms; m != nil; m = m->next) {
+			m->s->type = SWINDOWS | SSUB;
+			m->s->sub = dynamic->sub;
+			dynamic->sub = m->s;
+			m->s->value = dynamic->size;
+			dynamic->size += 4;
+		}
+		dynamic->size += 4;
 	}
-	ds[0].FirstThunk = size;
-	for(f=fs; f->name; f++)
-		size += sizeof(fs[0].thunk);
+		
+	return dr;
+}
 
+static void
+addimports(vlong fileoff, IMAGE_SECTION_HEADER *datsect)
+{
 	IMAGE_SECTION_HEADER *isect;
-	isect = new_section(".idata", size, 0);
+	uint32 va;
+	int noff, aoff, o, last_fn, last_name_off, iat_off;
+	Imp *m;
+	Dll *d;
+	Sym* dynamic;
+	
+	isect = addpesection(".idata", nsize, nsize, 0);
 	isect->Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA|
 		IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
-	
-	uint32 va = isect->VirtualAddress;
+	va = isect->VirtualAddress;
 	oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].VirtualAddress = va;
 	oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].Size = isect->VirtualSize;
 
-	ds[0].Name += va;
-	ds[0].FirstThunk += va;
-	for(f=fs; f->name; f++)
-		f->thunk += va;
+	seek(cout, fileoff, 0);
 
-	vlong off = seek(cout, 0, 1);
-	seek(cout, 0, 2);
-	for(d=ds; ; d++) {
-		lputl(d->OriginalFirstThunk);
-		lputl(d->TimeDateStamp);
-		lputl(d->ForwarderChain);
-		lputl(d->Name);
-		lputl(d->FirstThunk);
-		if(!d->Name) 
-			break;
+	dynamic = lookup(".windynamic", 0);
+	iat_off = dynamic->value - PEBASE; // FirstThunk allocated in .data
+	oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IAT].VirtualAddress = iat_off;
+	oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IAT].Size = dynamic->size;
+
+	noff = va + 20*ndll + 20;
+	aoff = noff + 4*nimp + 4*ndll;
+	last_fn = 0;
+	last_name_off = aoff;
+	for(d = dr; d != nil; d = d->next) {
+		lputl(noff);
+		lputl(0);
+		lputl(0);
+		lputl(last_name_off);
+		lputl(iat_off);
+		last_fn = d->count;
+		noff += 4*last_fn + 4;
+		aoff += 4*last_fn + 4;
+		iat_off += 4*last_fn + 4;
+		last_name_off += strlen(d->name)+1;
 	}
-	strput(dllname);
-	for(f=fs; f->name; f++) {
-		wputl(0);
-		strput(f->name);
+	lputl(0); //end
+	lputl(0);
+	lputl(0);
+	lputl(0);
+	lputl(0);
+	
+	// put OriginalFirstThunk
+	o = last_name_off;
+	for(d = dr; d != nil; d = d->next) {
+		for(m = d->ms; m != nil; m = m->next) {
+			lputl(o);
+			o += 2 + strlen(m->s->dynimpname) + 1;
+		}
+		lputl(0);
+	}
+	// put names
+	for(d = dr; d != nil; d = d->next) {
+		strput(d->name);
+	}
+	// put hint+name
+	for(d = dr; d != nil; d = d->next) {
+		for(m = d->ms; m != nil; m = m->next) {
+			wputl(0);
+			strput(m->s->dynimpname);
+		}
+	}
+	
+	strnput("", isect->SizeOfRawData - nsize);
+	cflush();
+
+	// put FirstThunk
+	o = last_name_off;
+	seek(cout, datsect->PointerToRawData + dynamic->value - PEBASE - datsect->VirtualAddress, 0);
+	for(d = dr; d != nil; d = d->next) {
+		for(m = d->ms; m != nil; m = m->next) {
+			lputl(o);
+			o += 2 + strlen(m->s->dynimpname) + 1;
+		}
+		lputl(0);
 	}
-	for(f=fs; f->name; f++)
-		lputl(f->thunk);
-	strnput("", isect->SizeOfRawData - size);
 	cflush();
-	seek(cout, off, 0);
+	seek(cout, 0, 2);
+}
+
+void
+dope(void)
+{
+	initdynimport();
 }
 
 void
 asmbpe(void)
 {
+	IMAGE_SECTION_HEADER *t, *d;
+
 	switch(thechar) {
 	default:
 		diag("unknown PE architecture");
@@ -203,14 +314,16 @@ asmbpe(void)
 		break;
 	}
 
-	if(!debug['s']) {
-		IMAGE_SECTION_HEADER *symsect;
-		symsect = new_section(".symdat", 8+symsize+lcsize, 0);
-		symsect->Characteristics = IMAGE_SCN_MEM_READ|
-			IMAGE_SCN_CNT_INITIALIZED_DATA;
-	}
+	t = addpesection(".text", segtext.len, segtext.len, &segtext);
+	t->Characteristics = IMAGE_SCN_CNT_CODE|
+		IMAGE_SCN_CNT_INITIALIZED_DATA|
+		IMAGE_SCN_MEM_EXECUTE|IMAGE_SCN_MEM_READ;
+
+	d = addpesection(".data", segdata.len, segdata.filelen, &segdata);
+	d->Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA|
+		IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
 
-	add_import_table();
+	addimports(nextfileoff, d);
 
 	fh.NumberOfSections = nsect;
 	fh.TimeDateStamp = time(0);
@@ -223,24 +336,24 @@ asmbpe(void)
 	oh.Magic = 0x10b;	// PE32
 	oh.MajorLinkerVersion = 1;
 	oh.MinorLinkerVersion = 0;
-	oh.SizeOfCode = textsect->SizeOfRawData;
-	oh.SizeOfInitializedData = datsect->SizeOfRawData;
-	oh.SizeOfUninitializedData = bsssect->SizeOfRawData;
+	oh.SizeOfCode = t->SizeOfRawData;
+	oh.SizeOfInitializedData = d->SizeOfRawData;
+	oh.SizeOfUninitializedData = 0;
 	oh.AddressOfEntryPoint = entryvalue()-PEBASE;
-	oh.BaseOfCode = textsect->VirtualAddress;
-	oh.BaseOfData = datsect->VirtualAddress;
+	oh.BaseOfCode = t->VirtualAddress;
+	oh.BaseOfData = d->VirtualAddress;
 
 	oh.ImageBase = PEBASE;
-	oh.SectionAlignment = 0x00001000;
-	oh.FileAlignment = PEALIGN;
+	oh.SectionAlignment = PESECTALIGN;
+	oh.FileAlignment = PEFILEALIGN;
 	oh.MajorOperatingSystemVersion = 4;
 	oh.MinorOperatingSystemVersion = 0;
 	oh.MajorImageVersion = 1;
 	oh.MinorImageVersion = 0;
 	oh.MajorSubsystemVersion = 4;
 	oh.MinorSubsystemVersion = 0;
-	oh.SizeOfImage = sect_virt_begin;
-	oh.SizeOfHeaders = PERESERVE;
+	oh.SizeOfImage = nextsectoff;
+	oh.SizeOfHeaders = PEFILEHEADR;
 	oh.Subsystem = 3;	// WINDOWS_CUI
 	oh.SizeOfStackReserve = 0x00200000;
 	oh.SizeOfStackCommit = 0x00001000;
diff --git a/src/cmd/ld/pe.h b/src/cmd/ld/pe.h
index b64dd97c0..f8161cc4a 100644
--- a/src/cmd/ld/pe.h
+++ b/src/cmd/ld/pe.h
@@ -72,9 +72,16 @@ typedef struct {
 	uint32 FirstThunk;
 } IMAGE_IMPORT_DESCRIPTOR;
 
-#define PERESERVE	0x400
-#define PEALIGN		0x200
 #define PEBASE		0x00400000
+// SectionAlignment must be greater than or equal to FileAlignment.
+// The default is the page size for the architecture.
+#define PESECTALIGN	0x1000
+// FileAlignment should be a power of 2 between 512 and 64 K, inclusive.
+// The default is 512. If the SectionAlignment is less than
+// the architecture's page size, then FileAlignment must match SectionAlignment.
+#define PEFILEALIGN	(2<<8)
+extern	int32	PESECTHEADR;
+extern	int32	PEFILEHEADR;
 
 enum {
 	IMAGE_FILE_MACHINE_I386 = 0x14c,
@@ -112,5 +119,6 @@ enum {
 };
 
 void peinit(void);
-void dope(void);
 void asmbpe(void);
+void dope(void);
+
diff --git a/src/cmd/ld/symtab.c b/src/cmd/ld/symtab.c
new file mode 100644
index 000000000..26e4def64
--- /dev/null
+++ b/src/cmd/ld/symtab.c
@@ -0,0 +1,259 @@
+// Inferno utils/6l/span.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6l/span.c
+//
+//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
+//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+//	Portions Copyright © 1997-1999 Vita Nuova Limited
+//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
+//	Portions Copyright © 2004,2006 Bruce Ellis
+//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
+//	Portions Copyright © 2009 The Go Authors.  All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Symbol table.
+
+#include	"l.h"
+#include	"../ld/lib.h"
+#include	"../ld/elf.h"
+
+char *elfstrdat;
+int elfstrsize;
+int maxelfstr;
+int elftextsh;
+
+int
+putelfstr(char *s)
+{
+	int off, n;
+
+	if(elfstrsize == 0 && s[0] != 0) {
+		// first entry must be empty string
+		putelfstr("");
+	}
+
+	n = strlen(s)+1;
+	if(elfstrsize+n > maxelfstr) {
+		maxelfstr = 2*(elfstrsize+n+(1<<20));
+		elfstrdat = realloc(elfstrdat, maxelfstr);
+	}
+	off = elfstrsize;
+	elfstrsize += n;
+	memmove(elfstrdat+off, s, n);
+	return off;
+}
+
+void
+putelfsym64(Sym *x, char *s, int t, vlong addr, vlong size, int ver, Sym *go)
+{
+	int bind, type, shndx, stroff;
+	
+	bind = STB_GLOBAL;
+	switch(t) {
+	default:
+		return;
+	case 'T':
+		type = STT_FUNC;
+		shndx = elftextsh + 0;
+		break;
+	case 'D':
+		type = STT_OBJECT;
+		shndx = elftextsh + 1;
+		break;
+	case 'B':
+		type = STT_OBJECT;
+		shndx = elftextsh + 2;
+		break;
+	}
+	
+	stroff = putelfstr(s);
+	LPUT(stroff);	// string
+	cput((bind<<4)|(type&0xF));
+	cput(0);
+	WPUT(shndx);
+	VPUT(addr);
+	VPUT(size);
+}
+
+void
+asmelfsym64(void)
+{
+	genasmsym(putelfsym64);
+}
+
+void
+putelfsym32(Sym *x, char *s, int t, vlong addr, vlong size, int ver, Sym *go)
+{
+	int bind, type, shndx, stroff;
+	
+	bind = STB_GLOBAL;
+	switch(t) {
+	default:
+		return;
+	case 'T':
+		type = STT_FUNC;
+		shndx = elftextsh + 0;
+		break;
+	case 'D':
+		type = STT_OBJECT;
+		shndx = elftextsh + 1;
+		break;
+	case 'B':
+		type = STT_OBJECT;
+		shndx = elftextsh + 2;
+		break;
+	}
+	
+	stroff = putelfstr(s);
+	LPUT(stroff);	// string
+	LPUT(addr);
+	LPUT(size);
+	cput((bind<<4)|(type&0xF));
+	cput(0);
+	WPUT(shndx);
+}
+
+void
+asmelfsym32(void)
+{
+	genasmsym(putelfsym32);
+}
+
+
+static Sym *symt;
+
+static void
+scput(int b)
+{
+	uchar *p;
+
+	symgrow(symt, symt->size+1);
+	p = symt->p + symt->size;
+	*p = b;
+	symt->size++;
+}
+
+static void
+slputb(int32 v)
+{
+	uchar *p;
+	
+	symgrow(symt, symt->size+4);
+	p = symt->p + symt->size;
+	*p++ = v>>24;
+	*p++ = v>>16;
+	*p++ = v>>8;
+	*p = v;
+	symt->size += 4;
+}
+
+void
+putsymb(Sym *s, char *name, int t, vlong v, vlong size, int ver, Sym *typ)
+{
+	int i, f, l;
+	Reloc *rel;
+
+	if(t == 'f')
+		name++;
+	l = 4;
+//	if(!debug['8'])
+//		l = 8;
+	if(s != nil) {
+		rel = addrel(symt);
+		rel->siz = l + Rbig;
+		rel->sym = s;
+		rel->type = D_ADDR;
+		rel->off = symt->size;
+		v = 0;
+	}	
+	if(l == 8)
+		slputb(v>>32);
+	slputb(v);
+	if(ver)
+		t += 'a' - 'A';
+	scput(t+0x80);			/* 0x80 is variable length */
+
+	if(t == 'Z' || t == 'z') {
+		scput(name[0]);
+		for(i=1; name[i] != 0 || name[i+1] != 0; i += 2) {
+			scput(name[i]);
+			scput(name[i+1]);
+		}
+		scput(0);
+		scput(0);
+		i++;
+	}
+	else {
+		for(i=0; name[i]; i++)
+			scput(name[i]);
+		scput(0);
+	}
+	if(typ) {
+		if(!typ->reachable)
+			diag("unreachable type %s", typ->name);
+		rel = addrel(symt);
+		rel->siz = l;
+		rel->sym = typ;
+		rel->type = D_ADDR;
+		rel->off = symt->size;
+	}
+	if(l == 8)
+		slputb(0);
+	slputb(0);
+
+	if(debug['n']) {
+		if(t == 'z' || t == 'Z') {
+			Bprint(&bso, "%c %.8llux ", t, v);
+			for(i=1; name[i] != 0 || name[i+1] != 0; i+=2) {
+				f = ((name[i]&0xff) << 8) | (name[i+1]&0xff);
+				Bprint(&bso, "/%x", f);
+			}
+			Bprint(&bso, "\n");
+			return;
+		}
+		if(ver)
+			Bprint(&bso, "%c %.8llux %s<%d> %s\n", t, v, s, ver, typ ? typ->name : "");
+		else
+			Bprint(&bso, "%c %.8llux %s %s\n", t, v, s, typ ? typ->name : "");
+	}
+}
+
+void
+symtab(void)
+{
+	// Define these so that they'll get put into the symbol table.
+	// data.c:/^address will provide the actual values.
+	xdefine("text", STEXT, 0);
+	xdefine("etext", STEXT, 0);
+	xdefine("rodata", SRODATA, 0);
+	xdefine("erodata", SRODATA, 0);
+	xdefine("data", SBSS, 0);
+	xdefine("edata", SBSS, 0);
+	xdefine("end", SBSS, 0);
+	xdefine("epclntab", SRODATA, 0);
+	xdefine("esymtab", SRODATA, 0);
+
+	symt = lookup("symtab", 0);
+	symt->type = SRODATA;
+	symt->size = 0;
+	symt->reachable = 1;
+
+	genasmsym(putsymb);
+}