[dev.power64] cmd/9l: introduce the power64 linker, based loosely on 5l

LGTM=rsc
R=rsc, iant
CC=golang-codereviews
https://golang.org/cl/123940043

src/cmd/9l/Makefile

+# Copyright 2012 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+include ../../Make.dist

src/cmd/9l/asm.c

+// Inferno utils/5l/asm.c
+// http://code.google.com/p/inferno-os/source/browse/utils/5l/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.
+
+// Writing object files.
+
+#include	"l.h"
+#include	"../ld/lib.h"
+#include	"../ld/elf.h"
+#include	"../ld/dwarf.h"
+
+
+char linuxdynld[] = "/lib64/ld64.so.1";
+char freebsddynld[] = "XXX";
+char openbsddynld[] = "XXX";
+char netbsddynld[] = "XXX";
+char dragonflydynld[] = "XXX";
+char solarisdynld[] = "XXX";
+
+static int
+needlib(char *name)
+{
+	char *p;
+	LSym *s;
+
+	if(*name == '\0')
+		return 0;
+
+	/* reuse hash code in symbol table */
+	p = smprint(".dynlib.%s", name);
+	s = linklookup(ctxt, p, 0);
+	free(p);
+	if(s->type == 0) {
+		s->type = 100;	// avoid SDATA, etc.
+		return 1;
+	}
+	return 0;
+}
+
+int	nelfsym = 1;
+
+// b is the addresses, a is the I-form branch instruction template, peform
+// addition so that the instruction jumps to address (offset) b.
+static int32
+braddoff(int32 a, int32 b)
+{
+	return (((uint32)a) & 0xfc000003U) | (0x03fffffcU & (uint32)((a & 0x3fffffcU) + b));
+}
+
+void
+adddynrela(LSym *rel, LSym *s, Reloc *r)
+{
+	// TODO(minux)
+	USED(rel); USED(s); USED(r);
+}
+
+void
+adddynrel(LSym *s, Reloc *r)
+{
+	LSym *targ;
+
+	// TODO(minux)
+
+	targ = r->sym;
+	ctxt->cursym = s;
+	diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ->name, r->type, targ->type);
+}
+
+int
+elfreloc1(Reloc *r, vlong sectoff)
+{
+	USED(r); USED(sectoff);
+	// TODO(minux)
+	return -1;
+}
+
+void
+elfsetupplt(void)
+{
+	// TODO(minux)
+	return;
+}
+
+int
+machoreloc1(Reloc *r, vlong sectoff)
+{
+	USED(r);
+	USED(sectoff);
+
+	return -1;
+}
+
+
+int
+archreloc(Reloc *r, LSym *s, vlong *val)
+{
+	uint32 o1, o2;
+	int32 t;
+
+	if(linkmode == LinkExternal) {
+		// TODO(minux): translate R_ADDRPOWER and R_CALLPOWER into standard ELF relocations.
+		// R_ADDRPOWER corresponds to R_PPC_ADDR16_HA and R_PPC_ADDR16_LO.
+		// R_CALLPOWER corresponds to R_PPC_REL24.
+		return -1;
+	}
+	switch(r->type) {
+	case R_CONST:
+		*val = r->add;
+		return 0;
+	case R_GOTOFF:
+		*val = symaddr(r->sym) + r->add - symaddr(linklookup(ctxt, ".got", 0));
+		return 0;
+	case R_ADDRPOWER:
+		// r->add is two power64 instructions holding an immediate 32-bit constant.
+		// We want to add r->sym's address to that constant.
+		// The encoding of the immediate x<<16 + y,
+		// where x is the low 16 bits of the first instruction and y is the low 16
+		// bits of the second. Both x and y are signed (int16, not uint16).
+		o1 = r->add >> 32;
+		o2 = r->add;
+		t = symaddr(r->sym);
+		if(t < 0) {
+			ctxt->diag("relocation for %s is too big (>=2G): %lld", s->name, symaddr(r->sym));
+		}
+		t += ((o1 & 0xffff) << 16) + ((int32)o2 << 16 >> 16);
+		if(t & 0x8000)
+			t += 0x10000;
+		o1 = (o1 & 0xffff0000) | ((t >> 16) & 0xffff);
+		o2 = (o2 & 0xffff0000) | (t & 0xffff);
+		// when laid out, the instruction order must always be o1, o2.
+		if(ctxt->arch->endian == BigEndian)
+			*val = ((vlong)o1 << 32) | o2;
+		else
+			*val = ((vlong)o2 << 32) | o1;
+		return 0;
+	case R_CALLPOWER:
+		*val = braddoff((uint32)r->add, (int32)(symaddr(r->sym) - (s->value + r->off)));
+		return 0;
+	}
+	return -1;
+}
+
+void
+adddynsym(Link *ctxt, LSym *s)
+{
+	USED(ctxt); USED(s);
+	// TODO(minux)
+	return;
+}
+
+void
+adddynlib(char *lib)
+{
+	LSym *s;
+	
+	if(!needlib(lib))
+		return;
+	
+	if(iself) {
+		s = linklookup(ctxt, ".dynstr", 0);
+		if(s->size == 0)
+			addstring(s, "");
+		elfwritedynent(linklookup(ctxt, ".dynamic", 0), DT_NEEDED, addstring(s, lib));
+	} else {
+		diag("adddynlib: unsupported binary format");
+	}
+}
+
+void
+asmb(void)
+{
+	uint32 symo;
+	Section *sect;
+	LSym *sym;
+	int i;
+
+	if(debug['v'])
+		Bprint(&bso, "%5.2f asmb\n", cputime());
+	Bflush(&bso);
+
+	if(iself)
+		asmbelfsetup();
+
+	sect = segtext.sect;
+	cseek(sect->vaddr - segtext.vaddr + segtext.fileoff);
+	codeblk(sect->vaddr, sect->len);
+	for(sect = sect->next; sect != nil; sect = sect->next) {
+		cseek(sect->vaddr - segtext.vaddr + segtext.fileoff);
+		datblk(sect->vaddr, sect->len);
+	}
+
+	if(segrodata.filelen > 0) {
+		if(debug['v'])
+			Bprint(&bso, "%5.2f rodatblk\n", cputime());
+		Bflush(&bso);
+
+		cseek(segrodata.fileoff);
+		datblk(segrodata.vaddr, segrodata.filelen);
+	}
+
+	if(debug['v'])
+		Bprint(&bso, "%5.2f datblk\n", cputime());
+	Bflush(&bso);
+
+	cseek(segdata.fileoff);
+	datblk(segdata.vaddr, segdata.filelen);
+
+	/* output symbol table */
+	symsize = 0;
+	lcsize = 0;
+	symo = 0;
+	if(!debug['s']) {
+		// TODO: rationalize
+		if(debug['v'])
+			Bprint(&bso, "%5.2f sym\n", cputime());
+		Bflush(&bso);
+		switch(HEADTYPE) {
+		default:
+			if(iself)
+				goto ElfSym;
+		case Hplan9:
+			symo = HEADR+segtext.len+segdata.filelen;
+			break;
+		ElfSym:
+			symo = rnd(HEADR+segtext.filelen, INITRND)+rnd(HEADR+segrodata.filelen, INITRND)+segdata.filelen;
+			symo = rnd(symo, INITRND);
+			break;
+		}
+		cseek(symo);
+		switch(HEADTYPE) {
+		default:
+			if(iself) {
+				if(debug['v'])
+					Bprint(&bso, "%5.2f elfsym\n", cputime());
+				asmelfsym();
+				cflush();
+				cwrite(elfstrdat, elfstrsize);
+	
+				if(debug['v'])
+					Bprint(&bso, "%5.2f dwarf\n", cputime());
+				dwarfemitdebugsections();
+				
+				if(linkmode == LinkExternal)
+					elfemitreloc();
+			}
+			break;
+		case Hplan9:
+			asmplan9sym();
+			cflush();
+
+			sym = linklookup(ctxt, "pclntab", 0);
+			if(sym != nil) {
+				lcsize = sym->np;
+				for(i=0; i < lcsize; i++)
+					cput(sym->p[i]);
+
+				cflush();
+			}
+			break;
+		}
+	}
+
+	ctxt->cursym = nil;
+	if(debug['v'])
+		Bprint(&bso, "%5.2f header\n", cputime());
+	Bflush(&bso);
+	cseek(0L);
+	switch(HEADTYPE) {
+	default:
+	case Hplan9:	/* plan 9 */
+		LPUT(0x647);			/* magic */
+		LPUT(segtext.filelen);			/* sizes */
+		LPUT(segdata.filelen);
+		LPUT(segdata.len - segdata.filelen);
+		LPUT(symsize);			/* nsyms */
+		LPUT(entryvalue());		/* va of entry */
+		LPUT(0L);
+		LPUT(lcsize);
+		break;
+	case Hlinux:
+	case Hfreebsd:
+	case Hnetbsd:
+	case Hopenbsd:
+	case Hnacl:
+		asmbelf(symo);
+		break;
+	}
+	cflush();
+	if(debug['c']){
+		print("textsize=%ulld\n", segtext.filelen);
+		print("datsize=%ulld\n", segdata.filelen);
+		print("bsssize=%ulld\n", segdata.len - segdata.filelen);
+		print("symsize=%d\n", symsize);
+		print("lcsize=%d\n", lcsize);
+		print("total=%lld\n", segtext.filelen+segdata.len+symsize+lcsize);
+	}
+}
+
+vlong
+rnd(vlong v, int32 r)
+{
+	vlong c;
+
+	if(r <= 0)
+		return v;
+	v += r - 1;
+	c = v % r;
+	if(c < 0)
+		c += r;
+	v -= c;
+	return v;
+}

src/cmd/9l/doc.go

+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ignore
+
+/*
+
+9l is the linker for the Power64.
+The $GOARCH for these tools is power64 (big endian) or
+power64le (little endian).
+
+The flags are documented in ../ld/doc.go.
+
+*/
+package main

src/cmd/9l/list.c

+// Inferno utils/5l/list.h
+// http://code.google.com/p/inferno-os/source/browse/utils/5l/list.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.
+
+// Printing.
+
+#include "l.h"
+#include "../ld/lib.h"
+
+void
+listinit(void)
+{
+	listinit9();
+}

src/cmd/9l/obj.c

+// Inferno utils/5l/obj.c
+// http://code.google.com/p/inferno-os/source/browse/utils/5l/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.
+
+#include	"l.h"
+#include	"../ld/lib.h"
+#include	"../ld/elf.h"
+#include	"../ld/dwarf.h"
+#include	<ar.h>
+
+char *thestring = "power64";
+LinkArch *thelinkarch;
+
+void
+linkarchinit(void)
+{
+	thestring = getgoarch();
+	if(strcmp(thestring, "power64le") == 0)
+		thelinkarch = &linkpower64le;
+	else
+		thelinkarch = &linkpower64;
+}
+
+void
+archinit(void)
+{
+	// getgoextlinkenabled is based on GO_EXTLINK_ENABLED when
+	// Go was built; see ../../make.bash.
+	if(linkmode == LinkAuto && strcmp(getgoextlinkenabled(), "0") == 0)
+		linkmode = LinkInternal;
+
+	switch(HEADTYPE) {
+	default:
+		if(linkmode == LinkAuto)
+			linkmode = LinkInternal;
+		if(linkmode == LinkExternal && strcmp(getgoextlinkenabled(), "1") != 0)
+			sysfatal("cannot use -linkmode=external with -H %s", headstr(HEADTYPE));
+		break;
+	}
+
+	switch(HEADTYPE) {
+	default:
+		diag("unknown -H option");
+		errorexit();
+	case Hplan9:	/* plan 9 */
+		HEADR = 32L;
+		if(INITTEXT == -1)
+			INITTEXT = 4128;
+		if(INITDAT == -1)
+			INITDAT = 0;
+		if(INITRND == -1)
+			INITRND = 4096;
+		break;
+	case Hlinux:	/* power64 elf */
+		debug['d'] = 1;	// TODO(minux): dynamic linking is not supported yet.
+		elfinit();
+		HEADR = ELFRESERVE;
+		if(INITTEXT == -1)
+			INITTEXT = 0x10000 + HEADR;
+		if(INITDAT == -1)
+			INITDAT = 0;
+		if(INITRND == -1)
+			INITRND = 4096;
+		break;
+	case Hnacl:
+		elfinit();
+		HEADR = 0x10000;
+		funcalign = 16;
+		if(INITTEXT == -1)
+			INITTEXT = 0x20000;
+		if(INITDAT == -1)
+			INITDAT = 0;
+		if(INITRND == -1)
+			INITRND = 0x10000;
+		break;
+	}
+	if(INITDAT != 0 && INITRND != 0)
+		print("warning: -D0x%ux is ignored because of -R0x%ux\n",
+			INITDAT, INITRND);
+}