src/cmd/9l/asm.c - go - Git at Google

 // 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 = segdata.fileoff+segdata.filelen;
 			break;
 		ElfSym:
 			symo = segdata.fileoff+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;
 }
	// 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 = segdata.fileoff+segdata.filelen;
	break;
	ElfSym:
	symo = segdata.fileoff+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;
	}