src/cmd/8l/obj.c - go - Git at Google

 // Inferno utils/8l/obj.c
 // http://code.google.com/p/inferno-os/source/browse/utils/8l/obj.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.

 // Reading object files.

 #define	EXTERN
 #include	"l.h"
 #include	"../ld/lib.h"
 #include	"../ld/elf.h"
 #include	"../ld/macho.h"
 #include	"../ld/dwarf.h"
 #include	"../ld/pe.h"
 #include	<ar.h>

 #ifndef	DEFAULT
 #define	DEFAULT	'9'
 #endif

 char	*noname		= "<none>";
 char	*thestring 	= "386";

 Header headers[] = {
    "garbunix", Hgarbunix,
    "unixcoff", Hunixcoff,
    "plan9", Hplan9x32,
    "msdoscom", Hmsdoscom,
    "msdosexe", Hmsdosexe,
    "darwin", Hdarwin,
    "linux", Hlinux,
    "freebsd", Hfreebsd,
    "windows", Hwindows,
    "windowsgui", Hwindows,
    0, 0
 };

 /*
  *	-Hgarbunix -T0x40004C -D0x10000000	is garbage unix
  *	-Hunixcoff -T0xd0 -R4			is unix coff
  *	-Hplan9 -T4128 -R4096			is plan9 format
  *	-Hmsdoscom -Tx -Rx			is MS-DOS .COM
  *	-Hmsdosexe -Tx -Rx			is fake MS-DOS .EXE
  *	-Hdarwin -Tx -Rx			is Apple Mach-O
  *	-Hlinux -Tx -Rx				is Linux ELF32
  *	-Hfreebsd -Tx -Rx			is FreeBSD ELF32
  *	-Hwindows -Tx -Rx			is MS Windows PE32
  */

 void
 usage(void)
 {
 	fprint(2, "usage: 8l [-options] [-E entry] [-H head] [-I interpreter] [-L dir] [-T text] [-R rnd] [-r path] [-o out] main.8\n");
 	exits("usage");
 }

 void
 main(int argc, char *argv[])
 {
 	int c;

 	Binit(&bso, 1, OWRITE);
 	cout = -1;
 	listinit();
 	memset(debug, 0, sizeof(debug));
 	nerrors = 0;
 	outfile = nil;
 	HEADTYPE = -1;
 	INITTEXT = -1;
 	INITDAT = -1;
 	INITRND = -1;
 	INITENTRY = 0;

 	ARGBEGIN {
 	default:
 		c = ARGC();
 		if(c == 'l')
 			usage();
  		if(c >= 0 && c < sizeof(debug))
 			debug[c]++;
 		break;
 	case 'o': /* output to (next arg) */
 		outfile = EARGF(usage());
 		break;
 	case 'E':
 		INITENTRY = EARGF(usage());
 		break;
 	case 'H':
 		HEADTYPE = headtype(EARGF(usage()));
 		break;
 	case 'I':
 		interpreter = EARGF(usage());
 		break;
 	case 'L':
 		Lflag(EARGF(usage()));
 		break;
 	case 'T':
 		INITTEXT = atolwhex(EARGF(usage()));
 		break;
 	case 'D':
 		INITDAT = atolwhex(EARGF(usage()));
 		break;
 	case 'R':
 		INITRND = atolwhex(EARGF(usage()));
 		break;
 	case 'r':
 		rpath = EARGF(usage());
 		break;
 	case 'V':
 		print("%cl version %s\n", thechar, getgoversion());
 		errorexit();
 	} ARGEND

 	if(argc != 1)
 		usage();

 	mywhatsys();	// get goos

 	if(HEADTYPE == -1)
 		HEADTYPE = headtype(goos);

 	if(outfile == nil) {
 		if(HEADTYPE == Hwindows)
 			outfile = "8.out.exe";
 		else
 			outfile = "8.out";
 	}

 	libinit();

 	switch(HEADTYPE) {
 	default:
 		diag("unknown -H option");
 		errorexit();

 	case Hgarbunix:	/* this is garbage */
 		HEADR = 20L+56L;
 		if(INITTEXT == -1)
 			INITTEXT = 0x40004CL;
 		if(INITDAT == -1)
 			INITDAT = 0x10000000L;
 		if(INITRND == -1)
 			INITRND = 0;
 		break;
 	case Hunixcoff:	/* is unix coff */
 		HEADR = 0xd0L;
 		if(INITTEXT == -1)
 			INITTEXT = 0xd0;
 		if(INITDAT == -1)
 			INITDAT = 0x400000;
 		if(INITRND == -1)
 			INITRND = 0;
 		break;
 	case Hplan9x32:	/* plan 9 */
 		tlsoffset = -8;
 		HEADR = 32L;
 		if(INITTEXT == -1)
 			INITTEXT = 4096+32;
 		if(INITDAT == -1)
 			INITDAT = 0;
 		if(INITRND == -1)
 			INITRND = 4096;
 		break;
 	case Hmsdoscom:	/* MS-DOS .COM */
 		HEADR = 0;
 		if(INITTEXT == -1)
 			INITTEXT = 0x0100;
 		if(INITDAT == -1)
 			INITDAT = 0;
 		if(INITRND == -1)
 			INITRND = 4;
 		break;
 	case Hmsdosexe:	/* fake MS-DOS .EXE */
 		HEADR = 0x200;
 		if(INITTEXT == -1)
 			INITTEXT = 0x0100;
 		if(INITDAT == -1)
 			INITDAT = 0;
 		if(INITRND == -1)
 			INITRND = 4;
 		HEADR += (INITTEXT & 0xFFFF);
 		if(debug['v'])
 			Bprint(&bso, "HEADR = 0x%d\n", HEADR);
 		break;
 	case Hdarwin:	/* apple MACH */
 		/*
 		 * OS X system constant - offset from %gs to our TLS.
 		 * Explained in ../../libcgo/darwin_386.c.
 		 */
 		tlsoffset = 0x468;
 		machoinit();
 		HEADR = INITIAL_MACHO_HEADR;
 		if(INITTEXT == -1)
 			INITTEXT = 4096+HEADR;
 		if(INITDAT == -1)
 			INITDAT = 0;
 		if(INITRND == -1)
 			INITRND = 4096;
 		break;
 	case Hlinux:	/* elf32 executable */
 	case Hfreebsd:
 		/*
 		 * ELF uses TLS offsets negative from %gs.
 		 * Translate 0(GS) and 4(GS) into -8(GS) and -4(GS).
 		 * Also known to ../../pkg/runtime/linux/386/sys.s
 		 * and ../../libcgo/linux_386.c.
 		 */
 		tlsoffset = -8;
 		elfinit();
 		HEADR = ELFRESERVE;
 		if(INITTEXT == -1)
 			INITTEXT = 0x08048000+HEADR;
 		if(INITDAT == -1)
 			INITDAT = 0;
 		if(INITRND == -1)
 			INITRND = 4096;
 		break;
 	case Hwindows: /* PE executable */
 		peinit();
 		HEADR = PEFILEHEADR;
 		if(INITTEXT == -1)
 			INITTEXT = PEBASE+PESECTHEADR;
 		if(INITDAT == -1)
 			INITDAT = 0;
 		if(INITRND == -1)
 			INITRND = PESECTALIGN;
 		break;
 	}
 	if(INITDAT != 0 && INITRND != 0)
 		print("warning: -D0x%ux is ignored because of -R0x%ux\n",
 			INITDAT, INITRND);
 	if(debug['v'])
 		Bprint(&bso, "HEADER = -H0x%d -T0x%ux -D0x%ux -R0x%ux\n",
 			HEADTYPE, INITTEXT, INITDAT, INITRND);
 	Bflush(&bso);

 	instinit();
 	zprg.link = P;
 	zprg.pcond = P;
 	zprg.back = 2;
 	zprg.as = AGOK;
 	zprg.from.type = D_NONE;
 	zprg.from.index = D_NONE;
 	zprg.from.scale = 1;
 	zprg.to = zprg.from;

 	pcstr = "%.6ux ";
 	nuxiinit();
 	histgen = 0;
 	pc = 0;
 	dtype = 4;
 	version = 0;
 	cbp = buf.cbuf;
 	cbc = sizeof(buf.cbuf);

 	addlibpath("command line", "command line", argv[0], "main");
 	loadlib();
 	deadcode();
 	patch();
 	follow();
 	doelf();
 	if(HEADTYPE == Hdarwin)
 		domacho();
 	if(HEADTYPE == Hwindows)
 		dope();
 	dostkoff();
 	if(debug['p'])
 		if(debug['1'])
 			doprof1();
 		else
 			doprof2();
 	span();
 	addexport();
 	textaddress();
 	pclntab();
 	symtab();
 	dodata();
 	address();
 	doweak();
 	reloc();
 	asmb();
 	undef();
 	if(debug['v']) {
 		Bprint(&bso, "%5.2f cpu time\n", cputime());
 		Bprint(&bso, "%d symbols\n", nsymbol);
 		Bprint(&bso, "%d sizeof adr\n", sizeof(Adr));
 		Bprint(&bso, "%d sizeof prog\n", sizeof(Prog));
 	}
 	Bflush(&bso);

 	errorexit();
 }

 static Sym*
 zsym(char *pn, Biobuf *f, Sym *h[])
 {
 	int o;

 	o = Bgetc(f);
 	if(o < 0 || o >= NSYM || h[o] == nil)
 		mangle(pn);
 	return h[o];
 }

 static void
 zaddr(char *pn, Biobuf *f, Adr *a, Sym *h[])
 {
 	int t;
 	int32 l;
 	Sym *s;
 	Auto *u;

 	t = Bgetc(f);
 	a->index = D_NONE;
 	a->scale = 0;
 	if(t & T_INDEX) {
 		a->index = Bgetc(f);
 		a->scale = Bgetc(f);
 	}
 	a->type = D_NONE;
 	a->offset = 0;
 	if(t & T_OFFSET)
 		a->offset = Bget4(f);
 	a->offset2 = 0;
 	if(t & T_OFFSET2) {
 		a->offset2 = Bget4(f);
 		a->type = D_CONST2;
 	}
 	a->sym = S;
 	if(t & T_SYM)
 		a->sym = zsym(pn, f, h);
 	if(t & T_FCONST) {
 		a->ieee.l = Bget4(f);
 		a->ieee.h = Bget4(f);
 		a->type = D_FCONST;
 	} else
 	if(t & T_SCONST) {
 		Bread(f, a->scon, NSNAME);
 		a->type = D_SCONST;
 	}
 	if(t & T_TYPE)
 		a->type = Bgetc(f);
 	adrgotype = S;
 	if(t & T_GOTYPE)
 		adrgotype = zsym(pn, f, h);

 	t = a->type;
 	if(t == D_INDIR+D_GS)
 		a->offset += tlsoffset;

 	s = a->sym;
 	if(s == S)
 		return;
 	if(t != D_AUTO && t != D_PARAM) {
 		if(adrgotype)
 			s->gotype = adrgotype;
 		return;
 	}
 	l = a->offset;
 	for(u=curauto; u; u=u->link) {
 		if(u->asym == s)
 		if(u->type == t) {
 			if(u->aoffset > l)
 				u->aoffset = l;
 			if(adrgotype)
 				u->gotype = adrgotype;
 			return;
 		}
 	}

 	u = mal(sizeof(*u));
 	u->link = curauto;
 	curauto = u;
 	u->asym = s;
 	u->aoffset = l;
 	u->type = t;
 	u->gotype = adrgotype;
 }

 void
 nopout(Prog *p)
 {
 	p->as = ANOP;
 	p->from.type = D_NONE;
 	p->to.type = D_NONE;
 }

 void
 ldobj1(Biobuf *f, char *pkg, int64 len, char *pn)
 {
 	int32 ipc;
 	Prog *p;
 	int v, o, r, skip;
 	Sym *h[NSYM], *s;
 	uint32 sig;
 	int ntext;
 	int32 eof;
 	char *name, *x;
 	char src[1024];
 	Prog *lastp;

 	lastp = nil;
 	ntext = 0;
 	eof = Boffset(f) + len;
 	src[0] = 0;


 newloop:
 	memset(h, 0, sizeof(h));
 	version++;
 	histfrogp = 0;
 	ipc = pc;
 	skip = 0;

 loop:
 	if(f->state == Bracteof || Boffset(f) >= eof)
 		goto eof;
 	o = Bgetc(f);
 	if(o == Beof)
 		goto eof;
 	o |= Bgetc(f) << 8;
 	if(o <= AXXX || o >= ALAST) {
 		if(o < 0)
 			goto eof;
 		diag("%s:#%lld: opcode out of range: %#ux", pn, Boffset(f), o);
 		print("	probably not a .%c file\n", thechar);
 		errorexit();
 	}

 	if(o == ANAME || o == ASIGNAME) {
 		sig = 0;
 		if(o == ASIGNAME)
 			sig = Bget4(f);
 		v = Bgetc(f);	/* type */
 		o = Bgetc(f);	/* sym */
 		r = 0;
 		if(v == D_STATIC)
 			r = version;
 		name = Brdline(f, '\0');
 		if(name == nil) {
 			if(Blinelen(f) > 0) {
 				fprint(2, "%s: name too long\n", pn);
 				errorexit();
 			}
 			goto eof;
 		}
 		x = expandpkg(name, pkg);
 		s = lookup(x, r);
 		if(x != name)
 			free(x);

 		if(debug['S'] && r == 0)
 			sig = 1729;
 		if(sig != 0){
 			if(s->sig != 0 && s->sig != sig)
 				diag("incompatible type signatures"
 					"%ux(%s) and %ux(%s) for %s",
 					s->sig, s->file, sig, pn, s->name);
 			s->sig = sig;
 			s->file = pn;
 		}

 		if(debug['W'])
 			print("	ANAME	%s\n", s->name);
 		if(o < 0 || o >= nelem(h))
 			mangle(pn);
 		h[o] = s;
 		if((v == D_EXTERN || v == D_STATIC) && s->type == 0)
 			s->type = SXREF;
 		if(v == D_FILE) {
 			if(s->type != SFILE) {
 				histgen++;
 				s->type = SFILE;
 				s->value = histgen;
 			}
 			if(histfrogp < MAXHIST) {
 				histfrog[histfrogp] = s;
 				histfrogp++;
 			} else
 				collapsefrog(s);
 			dwarfaddfrag(s->value, s->name);
 		}
 		goto loop;
 	}

 	p = mal(sizeof(*p));
 	p->as = o;
 	p->line = Bget4(f);
 	p->back = 2;
 	p->ft = 0;
 	p->tt = 0;
 	zaddr(pn, f, &p->from, h);
 	fromgotype = adrgotype;
 	zaddr(pn, f, &p->to, h);

 	if(debug['W'])
 		print("%P\n", p);

 	switch(p->as) {
 	case AHISTORY:
 		if(p->to.offset == -1) {
 			addlib(src, pn);
 			histfrogp = 0;
 			goto loop;
 		}
 		if(src[0] == '\0')
 			copyhistfrog(src, sizeof src);
 		addhist(p->line, D_FILE);		/* 'z' */
 		if(p->to.offset)
 			addhist(p->to.offset, D_FILE1);	/* 'Z' */
 		histfrogp = 0;
 		goto loop;

 	case AEND:
 		histtoauto();
 		if(cursym != nil && cursym->text)
 			cursym->autom = curauto;
 		curauto = 0;
 		cursym = nil;
 		if(Boffset(f) == eof)
 			return;
 		goto newloop;

 	case AGLOBL:
 		s = p->from.sym;
 		if(s->type == 0 || s->type == SXREF) {
 			s->type = SBSS;
 			s->size = 0;
 		}
 		if(s->type != SBSS && !s->dupok) {
 			diag("%s: redefinition: %s in %s",
 				pn, s->name, TNAME);
 			s->type = SBSS;
 			s->size = 0;
 		}
 		if(p->to.offset > s->size)
 			s->size = p->to.offset;
 		if(p->from.scale & DUPOK)
 			s->dupok = 1;
 		if(p->from.scale & RODATA)
 			s->type = SRODATA;
 		goto loop;

 	case ADATA:
 		// Assume that AGLOBL comes after ADATA.
 		// If we've seen an AGLOBL that said this sym was DUPOK,
 		// ignore any more ADATA we see, which must be
 		// redefinitions.
 		s = p->from.sym;
 		if(s->dupok) {
 //			if(debug['v'])
 //				Bprint(&bso, "skipping %s in %s: dupok\n", s->name, pn);
 			goto loop;
 		}
 		if(s->file == nil)
 			s->file = pn;
 		else if(s->file != pn) {
 			diag("multiple initialization for %s: in both %s and %s", s->name, s->file, pn);
 			errorexit();
 		}
 		savedata(s, p, pn);
 		unmal(p, sizeof *p);
 		goto loop;

 	case AGOK:
 		diag("%s: GOK opcode in %s", pn, TNAME);
 		pc++;
 		goto loop;

 	case ATEXT:
 		s = p->from.sym;
 		if(s->text != nil) {
 			diag("%s: %s: redefinition", pn, s->name);
 			return;
 		}
 		if(ntext++ == 0 && s->type != 0 && s->type != SXREF) {
 			/* redefinition, so file has probably been seen before */
 			if(debug['v'])
 				diag("skipping: %s: redefinition: %s", pn, s->name);
 			return;
 		}
 		if(cursym != nil && cursym->text) {
 			histtoauto();
 			cursym->autom = curauto;
 			curauto = 0;
 		}
 		skip = 0;
 		if(etextp)
 			etextp->next = s;
 		else
 			textp = s;
 		etextp = s;
 		s->text = p;
 		cursym = s;
 		if(s->type != 0 && s->type != SXREF) {
 			if(p->from.scale & DUPOK) {
 				skip = 1;
 				goto casdef;
 			}
 			diag("%s: redefinition: %s\n%P", pn, s->name, p);
 		}
 		s->type = STEXT;
 		s->value = pc;
 		lastp = p;
 		p->pc = pc++;
 		goto loop;

 	case AFMOVF:
 	case AFADDF:
 	case AFSUBF:
 	case AFSUBRF:
 	case AFMULF:
 	case AFDIVF:
 	case AFDIVRF:
 	case AFCOMF:
 	case AFCOMFP:
 		if(skip)
 			goto casdef;
 		if(p->from.type == D_FCONST) {
 			/* size sb 9 max */
 			sprint(literal, "$%ux", ieeedtof(&p->from.ieee));
 			s = lookup(literal, 0);
 			if(s->type == 0) {
 				s->type = SDATA;
 				adduint32(s, ieeedtof(&p->from.ieee));
 				s->reachable = 0;
 			}
 			p->from.type = D_EXTERN;
 			p->from.sym = s;
 			p->from.offset = 0;
 		}
 		goto casdef;

 	case AFMOVD:
 	case AFADDD:
 	case AFSUBD:
 	case AFSUBRD:
 	case AFMULD:
 	case AFDIVD:
 	case AFDIVRD:
 	case AFCOMD:
 	case AFCOMDP:
 		if(skip)
 			goto casdef;
 		if(p->from.type == D_FCONST) {
 			/* size sb 18 max */
 			sprint(literal, "$%ux.%ux",
 				p->from.ieee.l, p->from.ieee.h);
 			s = lookup(literal, 0);
 			if(s->type == 0) {
 				s->type = SDATA;
 				adduint32(s, p->from.ieee.l);
 				adduint32(s, p->from.ieee.h);
 				s->reachable = 0;
 			}
 			p->from.type = D_EXTERN;
 			p->from.sym = s;
 			p->from.offset = 0;
 		}
 		goto casdef;

 	casdef:
 	default:
 		if(skip)
 			nopout(p);
 		p->pc = pc;
 		pc++;

 		if(p->to.type == D_BRANCH)
 			p->to.offset += ipc;
 		if(lastp == nil) {
 			if(p->as != ANOP)
 				diag("unexpected instruction: %P", p);
 			goto loop;
 		}
 		lastp->link = p;
 		lastp = p;
 		goto loop;
 	}

 eof:
 	diag("truncated object file: %s", pn);
 }

 Prog*
 prg(void)
 {
 	Prog *p;

 	p = mal(sizeof(Prog));
 	*p = zprg;
 	return p;
 }

 Prog*
 copyp(Prog *q)
 {
 	Prog *p;

 	p = prg();
 	*p = *q;
 	return p;
 }

 Prog*
 appendp(Prog *q)
 {
 	Prog *p;

 	p = prg();
 	p->link = q->link;
 	q->link = p;
 	p->line = q->line;
 	return p;
 }
	// Inferno utils/8l/obj.c
	// http://code.google.com/p/inferno-os/source/browse/utils/8l/obj.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.

	// Reading object files.

	#define EXTERN
	#include "l.h"
	#include "../ld/lib.h"
	#include "../ld/elf.h"
	#include "../ld/macho.h"
	#include "../ld/dwarf.h"
	#include "../ld/pe.h"
	#include <ar.h>

	#ifndef DEFAULT
	#define DEFAULT '9'
	#endif

	char *noname = "<none>";
	char *thestring = "386";

	Header headers[] = {
	"garbunix", Hgarbunix,
	"unixcoff", Hunixcoff,
	"plan9", Hplan9x32,
	"msdoscom", Hmsdoscom,
	"msdosexe", Hmsdosexe,
	"darwin", Hdarwin,
	"linux", Hlinux,
	"freebsd", Hfreebsd,
	"windows", Hwindows,
	"windowsgui", Hwindows,
	0, 0
	};

	/*
	* -Hgarbunix -T0x40004C -D0x10000000 is garbage unix
	* -Hunixcoff -T0xd0 -R4 is unix coff
	* -Hplan9 -T4128 -R4096 is plan9 format
	* -Hmsdoscom -Tx -Rx is MS-DOS .COM
	* -Hmsdosexe -Tx -Rx is fake MS-DOS .EXE
	* -Hdarwin -Tx -Rx is Apple Mach-O
	* -Hlinux -Tx -Rx is Linux ELF32
	* -Hfreebsd -Tx -Rx is FreeBSD ELF32
	* -Hwindows -Tx -Rx is MS Windows PE32
	*/

	void
	usage(void)
	{
	fprint(2, "usage: 8l [-options] [-E entry] [-H head] [-I interpreter] [-L dir] [-T text] [-R rnd] [-r path] [-o out] main.8\n");
	exits("usage");
	}

	void
	main(int argc, char *argv[])
	{
	int c;

	Binit(&bso, 1, OWRITE);
	cout = -1;
	listinit();
	memset(debug, 0, sizeof(debug));
	nerrors = 0;
	outfile = nil;
	HEADTYPE = -1;
	INITTEXT = -1;
	INITDAT = -1;
	INITRND = -1;
	INITENTRY = 0;

	ARGBEGIN {
	default:
	c = ARGC();
	if(c == 'l')
	usage();
	if(c >= 0 && c < sizeof(debug))
	debug[c]++;
	break;
	case 'o': /* output to (next arg) */
	outfile = EARGF(usage());
	break;
	case 'E':
	INITENTRY = EARGF(usage());
	break;
	case 'H':
	HEADTYPE = headtype(EARGF(usage()));
	break;
	case 'I':
	interpreter = EARGF(usage());
	break;
	case 'L':
	Lflag(EARGF(usage()));
	break;
	case 'T':
	INITTEXT = atolwhex(EARGF(usage()));
	break;
	case 'D':
	INITDAT = atolwhex(EARGF(usage()));
	break;
	case 'R':
	INITRND = atolwhex(EARGF(usage()));
	break;
	case 'r':
	rpath = EARGF(usage());
	break;
	case 'V':
	print("%cl version %s\n", thechar, getgoversion());
	errorexit();
	} ARGEND

	if(argc != 1)
	usage();

	mywhatsys(); // get goos

	if(HEADTYPE == -1)
	HEADTYPE = headtype(goos);

	if(outfile == nil) {
	if(HEADTYPE == Hwindows)
	outfile = "8.out.exe";
	else
	outfile = "8.out";
	}

	libinit();

	switch(HEADTYPE) {
	default:
	diag("unknown -H option");
	errorexit();

	case Hgarbunix: /* this is garbage */
	HEADR = 20L+56L;
	if(INITTEXT == -1)
	INITTEXT = 0x40004CL;
	if(INITDAT == -1)
	INITDAT = 0x10000000L;
	if(INITRND == -1)
	INITRND = 0;
	break;
	case Hunixcoff: /* is unix coff */
	HEADR = 0xd0L;
	if(INITTEXT == -1)
	INITTEXT = 0xd0;
	if(INITDAT == -1)
	INITDAT = 0x400000;
	if(INITRND == -1)
	INITRND = 0;
	break;
	case Hplan9x32: /* plan 9 */
	tlsoffset = -8;
	HEADR = 32L;
	if(INITTEXT == -1)
	INITTEXT = 4096+32;
	if(INITDAT == -1)
	INITDAT = 0;
	if(INITRND == -1)
	INITRND = 4096;
	break;
	case Hmsdoscom: /* MS-DOS .COM */
	HEADR = 0;
	if(INITTEXT == -1)
	INITTEXT = 0x0100;
	if(INITDAT == -1)
	INITDAT = 0;
	if(INITRND == -1)
	INITRND = 4;
	break;
	case Hmsdosexe: /* fake MS-DOS .EXE */
	HEADR = 0x200;
	if(INITTEXT == -1)
	INITTEXT = 0x0100;
	if(INITDAT == -1)
	INITDAT = 0;
	if(INITRND == -1)
	INITRND = 4;
	HEADR += (INITTEXT & 0xFFFF);
	if(debug['v'])
	Bprint(&bso, "HEADR = 0x%d\n", HEADR);
	break;
	case Hdarwin: /* apple MACH */
	/*
	* OS X system constant - offset from %gs to our TLS.
	* Explained in ../../libcgo/darwin_386.c.
	*/
	tlsoffset = 0x468;
	machoinit();
	HEADR = INITIAL_MACHO_HEADR;
	if(INITTEXT == -1)
	INITTEXT = 4096+HEADR;
	if(INITDAT == -1)
	INITDAT = 0;
	if(INITRND == -1)
	INITRND = 4096;
	break;
	case Hlinux: /* elf32 executable */
	case Hfreebsd:
	/*
	* ELF uses TLS offsets negative from %gs.
	* Translate 0(GS) and 4(GS) into -8(GS) and -4(GS).
	* Also known to ../../pkg/runtime/linux/386/sys.s
	* and ../../libcgo/linux_386.c.
	*/
	tlsoffset = -8;
	elfinit();
	HEADR = ELFRESERVE;
	if(INITTEXT == -1)
	INITTEXT = 0x08048000+HEADR;
	if(INITDAT == -1)
	INITDAT = 0;
	if(INITRND == -1)
	INITRND = 4096;
	break;
	case Hwindows: /* PE executable */
	peinit();
	HEADR = PEFILEHEADR;
	if(INITTEXT == -1)
	INITTEXT = PEBASE+PESECTHEADR;
	if(INITDAT == -1)
	INITDAT = 0;
	if(INITRND == -1)
	INITRND = PESECTALIGN;
	break;
	}
	if(INITDAT != 0 && INITRND != 0)
	print("warning: -D0x%ux is ignored because of -R0x%ux\n",
	INITDAT, INITRND);
	if(debug['v'])
	Bprint(&bso, "HEADER = -H0x%d -T0x%ux -D0x%ux -R0x%ux\n",
	HEADTYPE, INITTEXT, INITDAT, INITRND);
	Bflush(&bso);

	instinit();
	zprg.link = P;
	zprg.pcond = P;
	zprg.back = 2;
	zprg.as = AGOK;
	zprg.from.type = D_NONE;
	zprg.from.index = D_NONE;
	zprg.from.scale = 1;
	zprg.to = zprg.from;

	pcstr = "%.6ux ";
	nuxiinit();
	histgen = 0;
	pc = 0;
	dtype = 4;
	version = 0;
	cbp = buf.cbuf;
	cbc = sizeof(buf.cbuf);

	addlibpath("command line", "command line", argv[0], "main");
	loadlib();
	deadcode();
	patch();
	follow();
	doelf();
	if(HEADTYPE == Hdarwin)
	domacho();
	if(HEADTYPE == Hwindows)
	dope();
	dostkoff();
	if(debug['p'])
	if(debug['1'])
	doprof1();
	else
	doprof2();
	span();
	addexport();
	textaddress();
	pclntab();
	symtab();
	dodata();
	address();
	doweak();
	reloc();
	asmb();
	undef();
	if(debug['v']) {
	Bprint(&bso, "%5.2f cpu time\n", cputime());
	Bprint(&bso, "%d symbols\n", nsymbol);
	Bprint(&bso, "%d sizeof adr\n", sizeof(Adr));
	Bprint(&bso, "%d sizeof prog\n", sizeof(Prog));
	}
	Bflush(&bso);

	errorexit();
	}

	static Sym*
	zsym(char pn, Biobuf f, Sym *h[])
	{
	int o;

	o = Bgetc(f);
	if(o < 0 \|\| o >= NSYM \|\| h[o] == nil)
	mangle(pn);
	return h[o];
	}

	static void
	zaddr(char pn, Biobuf f, Adr a, Sym h[])
	{
	int t;
	int32 l;
	Sym *s;
	Auto *u;

	t = Bgetc(f);
	a->index = D_NONE;
	a->scale = 0;
	if(t & T_INDEX) {
	a->index = Bgetc(f);
	a->scale = Bgetc(f);
	}
	a->type = D_NONE;
	a->offset = 0;
	if(t & T_OFFSET)
	a->offset = Bget4(f);
	a->offset2 = 0;
	if(t & T_OFFSET2) {
	a->offset2 = Bget4(f);
	a->type = D_CONST2;
	}
	a->sym = S;
	if(t & T_SYM)
	a->sym = zsym(pn, f, h);
	if(t & T_FCONST) {
	a->ieee.l = Bget4(f);
	a->ieee.h = Bget4(f);
	a->type = D_FCONST;
	} else
	if(t & T_SCONST) {
	Bread(f, a->scon, NSNAME);
	a->type = D_SCONST;
	}
	if(t & T_TYPE)
	a->type = Bgetc(f);
	adrgotype = S;
	if(t & T_GOTYPE)
	adrgotype = zsym(pn, f, h);

	t = a->type;
	if(t == D_INDIR+D_GS)
	a->offset += tlsoffset;

	s = a->sym;
	if(s == S)
	return;
	if(t != D_AUTO && t != D_PARAM) {
	if(adrgotype)
	s->gotype = adrgotype;
	return;
	}
	l = a->offset;
	for(u=curauto; u; u=u->link) {
	if(u->asym == s)
	if(u->type == t) {
	if(u->aoffset > l)
	u->aoffset = l;
	if(adrgotype)
	u->gotype = adrgotype;
	return;
	}
	}

	u = mal(sizeof(*u));
	u->link = curauto;
	curauto = u;
	u->asym = s;
	u->aoffset = l;
	u->type = t;
	u->gotype = adrgotype;
	}

	void
	nopout(Prog *p)
	{
	p->as = ANOP;
	p->from.type = D_NONE;
	p->to.type = D_NONE;
	}

	void
	ldobj1(Biobuf f, char pkg, int64 len, char *pn)
	{
	int32 ipc;
	Prog *p;
	int v, o, r, skip;
	Sym h[NSYM], s;
	uint32 sig;
	int ntext;
	int32 eof;
	char name, x;
	char src[1024];
	Prog *lastp;

	lastp = nil;
	ntext = 0;
	eof = Boffset(f) + len;
	src[0] = 0;


	newloop:
	memset(h, 0, sizeof(h));
	version++;
	histfrogp = 0;
	ipc = pc;
	skip = 0;

	loop:
	if(f->state == Bracteof \|\| Boffset(f) >= eof)
	goto eof;
	o = Bgetc(f);
	if(o == Beof)
	goto eof;
	o \|= Bgetc(f) << 8;
	if(o <= AXXX \|\| o >= ALAST) {
	if(o < 0)
	goto eof;
	diag("%s:#%lld: opcode out of range: %#ux", pn, Boffset(f), o);
	print(" probably not a .%c file\n", thechar);
	errorexit();
	}

	if(o == ANAME \|\| o == ASIGNAME) {
	sig = 0;
	if(o == ASIGNAME)
	sig = Bget4(f);
	v = Bgetc(f); /* type */
	o = Bgetc(f); /* sym */
	r = 0;
	if(v == D_STATIC)
	r = version;
	name = Brdline(f, '\0');
	if(name == nil) {
	if(Blinelen(f) > 0) {
	fprint(2, "%s: name too long\n", pn);
	errorexit();
	}
	goto eof;
	}
	x = expandpkg(name, pkg);
	s = lookup(x, r);
	if(x != name)
	free(x);

	if(debug['S'] && r == 0)
	sig = 1729;
	if(sig != 0){
	if(s->sig != 0 && s->sig != sig)
	diag("incompatible type signatures"
	"%ux(%s) and %ux(%s) for %s",
	s->sig, s->file, sig, pn, s->name);
	s->sig = sig;
	s->file = pn;
	}

	if(debug['W'])
	print(" ANAME %s\n", s->name);
	if(o < 0 \|\| o >= nelem(h))
	mangle(pn);
	h[o] = s;
	if((v == D_EXTERN \|\| v == D_STATIC) && s->type == 0)
	s->type = SXREF;
	if(v == D_FILE) {
	if(s->type != SFILE) {
	histgen++;
	s->type = SFILE;
	s->value = histgen;
	}
	if(histfrogp < MAXHIST) {
	histfrog[histfrogp] = s;
	histfrogp++;
	} else
	collapsefrog(s);
	dwarfaddfrag(s->value, s->name);
	}
	goto loop;
	}

	p = mal(sizeof(*p));
	p->as = o;
	p->line = Bget4(f);
	p->back = 2;
	p->ft = 0;
	p->tt = 0;
	zaddr(pn, f, &p->from, h);
	fromgotype = adrgotype;
	zaddr(pn, f, &p->to, h);

	if(debug['W'])
	print("%P\n", p);

	switch(p->as) {
	case AHISTORY:
	if(p->to.offset == -1) {
	addlib(src, pn);
	histfrogp = 0;
	goto loop;
	}
	if(src[0] == '\0')
	copyhistfrog(src, sizeof src);
	addhist(p->line, D_FILE); /* 'z' */
	if(p->to.offset)
	addhist(p->to.offset, D_FILE1); /* 'Z' */
	histfrogp = 0;
	goto loop;

	case AEND:
	histtoauto();
	if(cursym != nil && cursym->text)
	cursym->autom = curauto;
	curauto = 0;
	cursym = nil;
	if(Boffset(f) == eof)
	return;
	goto newloop;

	case AGLOBL:
	s = p->from.sym;
	if(s->type == 0 \|\| s->type == SXREF) {
	s->type = SBSS;
	s->size = 0;
	}
	if(s->type != SBSS && !s->dupok) {
	diag("%s: redefinition: %s in %s",
	pn, s->name, TNAME);
	s->type = SBSS;
	s->size = 0;
	}
	if(p->to.offset > s->size)
	s->size = p->to.offset;
	if(p->from.scale & DUPOK)
	s->dupok = 1;
	if(p->from.scale & RODATA)
	s->type = SRODATA;
	goto loop;

	case ADATA:
	// Assume that AGLOBL comes after ADATA.
	// If we've seen an AGLOBL that said this sym was DUPOK,
	// ignore any more ADATA we see, which must be
	// redefinitions.
	s = p->from.sym;
	if(s->dupok) {
	// if(debug['v'])
	// Bprint(&bso, "skipping %s in %s: dupok\n", s->name, pn);
	goto loop;
	}
	if(s->file == nil)
	s->file = pn;
	else if(s->file != pn) {
	diag("multiple initialization for %s: in both %s and %s", s->name, s->file, pn);
	errorexit();
	}
	savedata(s, p, pn);
	unmal(p, sizeof *p);
	goto loop;

	case AGOK:
	diag("%s: GOK opcode in %s", pn, TNAME);
	pc++;
	goto loop;

	case ATEXT:
	s = p->from.sym;
	if(s->text != nil) {
	diag("%s: %s: redefinition", pn, s->name);
	return;
	}
	if(ntext++ == 0 && s->type != 0 && s->type != SXREF) {
	/* redefinition, so file has probably been seen before */
	if(debug['v'])
	diag("skipping: %s: redefinition: %s", pn, s->name);
	return;
	}
	if(cursym != nil && cursym->text) {
	histtoauto();
	cursym->autom = curauto;
	curauto = 0;
	}
	skip = 0;
	if(etextp)
	etextp->next = s;
	else
	textp = s;
	etextp = s;
	s->text = p;
	cursym = s;
	if(s->type != 0 && s->type != SXREF) {
	if(p->from.scale & DUPOK) {
	skip = 1;
	goto casdef;
	}
	diag("%s: redefinition: %s\n%P", pn, s->name, p);
	}
	s->type = STEXT;
	s->value = pc;
	lastp = p;
	p->pc = pc++;
	goto loop;

	case AFMOVF:
	case AFADDF:
	case AFSUBF:
	case AFSUBRF:
	case AFMULF:
	case AFDIVF:
	case AFDIVRF:
	case AFCOMF:
	case AFCOMFP:
	if(skip)
	goto casdef;
	if(p->from.type == D_FCONST) {
	/* size sb 9 max */
	sprint(literal, "$%ux", ieeedtof(&p->from.ieee));
	s = lookup(literal, 0);
	if(s->type == 0) {
	s->type = SDATA;
	adduint32(s, ieeedtof(&p->from.ieee));
	s->reachable = 0;
	}
	p->from.type = D_EXTERN;
	p->from.sym = s;
	p->from.offset = 0;
	}
	goto casdef;

	case AFMOVD:
	case AFADDD:
	case AFSUBD:
	case AFSUBRD:
	case AFMULD:
	case AFDIVD:
	case AFDIVRD:
	case AFCOMD:
	case AFCOMDP:
	if(skip)
	goto casdef;
	if(p->from.type == D_FCONST) {
	/* size sb 18 max */
	sprint(literal, "$%ux.%ux",
	p->from.ieee.l, p->from.ieee.h);
	s = lookup(literal, 0);
	if(s->type == 0) {
	s->type = SDATA;
	adduint32(s, p->from.ieee.l);
	adduint32(s, p->from.ieee.h);
	s->reachable = 0;
	}
	p->from.type = D_EXTERN;
	p->from.sym = s;
	p->from.offset = 0;
	}
	goto casdef;

	casdef:
	default:
	if(skip)
	nopout(p);
	p->pc = pc;
	pc++;

	if(p->to.type == D_BRANCH)
	p->to.offset += ipc;
	if(lastp == nil) {
	if(p->as != ANOP)
	diag("unexpected instruction: %P", p);
	goto loop;
	}
	lastp->link = p;
	lastp = p;
	goto loop;
	}

	eof:
	diag("truncated object file: %s", pn);
	}

	Prog*
	prg(void)
	{
	Prog *p;

	p = mal(sizeof(Prog));
	*p = zprg;
	return p;
	}

	Prog*
	copyp(Prog *q)
	{
	Prog *p;

	p = prg();
	p = q;
	return p;
	}

	Prog*
	appendp(Prog *q)
	{
	Prog *p;

	p = prg();
	p->link = q->link;
	q->link = p;
	p->line = q->line;
	return p;
	}