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go/src/cmd/ld/data.c

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// 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/macho.h"
#include "../ld/pe.h"
#include "../../pkg/runtime/mgc0.h"
void dynreloc(void);
static vlong addaddrplus4(Sym *s, Sym *t, vlong add);
/*
* 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*
listsort(Sym *l, int (*cmp)(Sym*, Sym*), int off)
{
Sym *l1, *l2, *le;
#define NEXT(l) (*(Sym**)((char*)(l)+off))
if(l == 0 || NEXT(l) == 0)
return l;
l1 = l;
l2 = l;
for(;;) {
l2 = NEXT(l2);
if(l2 == 0)
break;
l2 = NEXT(l2);
if(l2 == 0)
break;
l1 = NEXT(l1);
}
l2 = NEXT(l1);
NEXT(l1) = 0;
l1 = listsort(l, cmp, off);
l2 = listsort(l2, cmp, off);
/* set up lead element */
if(cmp(l1, l2) < 0) {
l = l1;
l1 = NEXT(l1);
} else {
l = l2;
l2 = NEXT(l2);
}
le = l;
for(;;) {
if(l1 == 0) {
while(l2) {
NEXT(le) = l2;
le = l2;
l2 = NEXT(l2);
}
NEXT(le) = 0;
break;
}
if(l2 == 0) {
while(l1) {
NEXT(le) = l1;
le = l1;
l1 = NEXT(l1);
}
break;
}
if(cmp(l1, l2) < 0) {
NEXT(le) = l1;
le = l1;
l1 = NEXT(l1);
} else {
NEXT(le) = l2;
le = l2;
l2 = NEXT(l2);
}
}
NEXT(le) = 0;
return l;
#undef NEXT
}
Reloc*
addrel(Sym *s)
{
if(s->nr >= s->maxr) {
if(s->maxr == 0)
s->maxr = 4;
else
s->maxr <<= 1;
s->r = erealloc(s->r, s->maxr*sizeof s->r[0]);
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;
Sym *rs;
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++) {
r->done = 1;
off = r->off;
siz = r->siz;
if(off < 0 || off+siz > s->np) {
diag("%s: invalid relocation %d+%d not in [%d,%d)", s->name, off, siz, 0, s->np);
continue;
}
if(r->sym != S && (r->sym->type & SMASK == 0 || r->sym->type & SMASK == 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->type != STLSBSS && !r->sym->reachable)
diag("unreachable sym in relocation: %s %s", s->name, r->sym->name);
switch(r->type) {
default:
o = 0;
if(linkmode == LinkExternal || archreloc(r, s, &o) < 0)
diag("unknown reloc %d", r->type);
break;
case D_TLS:
r->done = 0;
o = 0;
break;
case D_ADDR:
if(linkmode == LinkExternal && r->sym->type != SCONST) {
r->done = 0;
// set up addend for eventual relocation via outer symbol.
rs = r->sym;
r->xadd = r->add;
while(rs->outer != nil) {
r->xadd += symaddr(rs) - symaddr(rs->outer);
rs = rs->outer;
}
if(rs->type != SHOSTOBJ && rs->sect == nil)
diag("missing section for %s", rs->name);
r->xsym = rs;
o = r->xadd;
if(iself) {
if(thechar == '6')
o = 0;
} else if(HEADTYPE == Hdarwin) {
if(rs->type != SHOSTOBJ)
o += symaddr(rs);
} else {
diag("unhandled pcrel relocation for %s", headtype);
}
break;
}
o = symaddr(r->sym) + r->add;
break;
case D_PCREL:
// r->sym can be null when CALL $(constant) is transformed from absolute PC to relative PC call.
if(linkmode == LinkExternal && r->sym && r->sym->type != SCONST && r->sym->sect != cursym->sect) {
r->done = 0;
// set up addend for eventual relocation via outer symbol.
rs = r->sym;
r->xadd = r->add;
while(rs->outer != nil) {
r->xadd += symaddr(rs) - symaddr(rs->outer);
rs = rs->outer;
}
r->xadd -= r->siz; // relative to address after the relocated chunk
if(rs->type != SHOSTOBJ && rs->sect == nil)
diag("missing section for %s", rs->name);
r->xsym = rs;
o = r->xadd;
if(iself) {
if(thechar == '6')
o = 0;
} else if(HEADTYPE == Hdarwin) {
if(rs->type != SHOSTOBJ)
o += symaddr(rs) - rs->sect->vaddr;
o -= r->off; // WTF?
} else {
diag("unhandled pcrel relocation for %s", headtype);
}
break;
}
o = 0;
if(r->sym)
o += symaddr(r->sym);
// NOTE: The (int32) cast on the next line works around a bug in Plan 9's 8c
// compiler. The expression s->value + r->off + r->siz is int32 + int32 +
// uchar, and Plan 9 8c incorrectly treats the expression as type uint32
// instead of int32, causing incorrect values when sign extended for adding
// to o. The bug only occurs on Plan 9, because this C program is compiled by
// the standard host compiler (gcc on most other systems).
o += r->add - (s->value + r->off + (int32)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:
if(r->type == D_PCREL) {
if(o != (int32)o)
diag("pc-relative relocation address is too big: %#llx", o);
} else {
if(o != (int32)o && o != (uint32)o)
diag("non-pc-relative relocation address is too big: %#llux", o);
}
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;
Sym *rel;
Sym *got;
if(HEADTYPE == Hwindows) {
Sym *rel, *targ;
rel = lookup(".rel", 0);
if(s == rel)
return;
for(r=s->r; r<s->r+s->nr; r++) {
targ = r->sym;
if(r->sym->plt == -2 && r->sym->got != -2) { // make dynimport JMP table for PE object files.
targ->plt = rel->size;
r->sym = rel;
r->add = targ->plt;
// jmp *addr
if(thechar == '8') {
adduint8(rel, 0xff);
adduint8(rel, 0x25);
addaddr(rel, targ);
adduint8(rel, 0x90);
adduint8(rel, 0x90);
} else {
adduint8(rel, 0xff);
adduint8(rel, 0x24);
adduint8(rel, 0x25);
addaddrplus4(rel, targ, 0);
adduint8(rel, 0x90);
}
} else if(r->sym->plt >= 0) {
r->sym = rel;
r->add = targ->plt;
}
}
return;
}
got = rel = nil;
if(flag_shared) {
rel = lookuprel();
got = lookup(".got", 0);
}
s->rel_ro = 0;
for(r=s->r; r<s->r+s->nr; r++) {
if(r->sym != S && r->sym->type == SDYNIMPORT || r->type >= 256)
adddynrel(s, r);
if(flag_shared && r->sym != S && s->type != SDYNIMPORT && r->type == D_ADDR
&& (s == got || s->type == SDATA || s->type == SGOSTRING || s->type == STYPE || s->type == SRODATA)) {
// Create address based RELATIVE relocation
adddynrela(rel, s, r);
if(s->type < SNOPTRDATA)
s->rel_ro = 1;
}
}
}
void
dynreloc(void)
{
Sym *s;
// -d suppresses dynamic loader format, so we may as well not
// compute these sections or mark their symbols as reachable.
if(debug['d'] && HEADTYPE != Hwindows)
return;
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 = erealloc(s->p, s->maxp);
memset(s->p+s->np, 0, s->maxp-s->np);
}
s->np = siz;
}
void
savedata(Sym *s, Prog *p, char *pn)
{
int32 off, siz, i, fl;
uchar *cast;
vlong o;
Reloc *r;
off = p->from.offset;
siz = p->datasize;
if(off < 0 || siz < 0 || off >= 1<<30 || siz >= 100)
mangle(pn);
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 *start, int32 addr, int32 size)
{
Sym *sym;
int32 eaddr;
uchar *p, *ep;
for(sym = start; 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, cpos());
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, (int)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, "%.6llux\t", (uvlong)p->pc);
q = sym->p + p->pc - sym->value;
n = epc - p->pc;
Bprint(&bso, "%-20.*I | %P\n", (int)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 i, eaddr;
uchar *p, *ep;
char *typ, *rsname;
Reloc *r;
if(debug['a'])
Bprint(&bso, "datblk [%#x,%#x) at offset %#llx\n", addr, addr+size, cpos());
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, "\t%.8ux| 00 ...\n", addr);
addr = sym->value;
}
Bprint(&bso, "%s\n\t%.8ux|", sym->name, (uint)addr);
p = sym->p;
ep = p + sym->np;
while(p < ep) {
if(p > sym->p && (int)(p-sym->p)%16 == 0)
Bprint(&bso, "\n\t%.8ux|", (uint)(addr+(p-sym->p)));
Bprint(&bso, " %.2ux", *p++);
}
addr += sym->np;
for(; addr < sym->value+sym->size; addr++)
Bprint(&bso, " %.2ux", 0);
Bprint(&bso, "\n");
if(linkmode == LinkExternal) {
for(i=0; i<sym->nr; i++) {
r = &sym->r[i];
rsname = "";
if(r->sym)
rsname = r->sym->name;
typ = "?";
switch(r->type) {
case D_ADDR:
typ = "addr";
break;
case D_PCREL:
typ = "pcrel";
break;
}
Bprint(&bso, "\treloc %.8ux/%d %s %s+%#llx [%#llx]\n",
(uint)(sym->value+r->off), r->siz, typ, rsname, (vlong)r->add, (vlong)(r->sym->value+r->add));
}
}
}
if(addr < eaddr)
Bprint(&bso, "\t%.8ux| 00 ...\n", (uint)addr);
Bprint(&bso, "\t%.8ux|\n", (uint)eaddr);
}
void
strnput(char *s, int n)
{
for(; n > 0 && *s; s++) {
cput(*s);
n--;
}
while(n > 0) {
cput(0);
n--;
}
}
void
addstrdata(char *name, char *value)
{
Sym *s, *sp;
char *p;
p = smprint("%s.str", name);
sp = lookup(p, 0);
free(p);
addstring(sp, value);
s = lookup(name, 0);
s->size = 0;
s->dupok = 1;
addaddr(s, sp);
adduint32(s, strlen(value));
if(PtrSize == 8)
adduint32(s, 0); // round struct to pointer width
// in case reachability has already been computed
sp->reachable = s->reachable;
}
vlong
addstring(Sym *s, char *str)
{
int n;
int32 r;
if(s->type == 0)
s->type = SNOPTRDATA;
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
setuintxx(Sym *s, vlong off, uint64 v, vlong wid)
{
int32 i, fl;
vlong o;
uchar *cast;
if(s->type == 0)
s->type = SDATA;
s->reachable = 1;
if(s->size < off+wid) {
s->size = off+wid;
symgrow(s, s->size);
}
fl = v;
cast = (uchar*)&fl;
switch(wid) {
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:
o = v;
cast = (uchar*)&o;
for(i=0; i<8; i++)
s->p[off+i] = cast[inuxi8[i]];
break;
}
return off;
}
vlong
adduintxx(Sym *s, uint64 v, int wid)
{
vlong off;
off = s->size;
setuintxx(s, off, v, wid);
return off;
}
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);
}
void
setuint8(Sym *s, vlong r, uint8 v)
{
setuintxx(s, r, v, 1);
}
void
setuint16(Sym *s, vlong r, uint16 v)
{
setuintxx(s, r, v, 2);
}
void
setuint32(Sym *s, vlong r, uint32 v)
{
setuintxx(s, r, v, 4);
}
void
setuint64(Sym *s, vlong r, uint64 v)
{
setuintxx(s, r, v, 8);
}
vlong
addaddrplus(Sym *s, Sym *t, vlong 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;
}
static vlong
addaddrplus4(Sym *s, Sym *t, vlong 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->siz = 4;
r->type = D_ADDR;
r->add = add;
return i;
}
vlong
addpcrelplus(Sym *s, Sym *t, vlong 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
setaddrplus(Sym *s, vlong off, Sym *t, vlong add)
{
Reloc *r;
if(s->type == 0)
s->type = SDATA;
s->reachable = 1;
if(off+PtrSize > s->size) {
s->size = off + PtrSize;
symgrow(s, s->size);
}
r = addrel(s);
r->sym = t;
r->off = off;
r->siz = PtrSize;
r->type = D_ADDR;
r->add = add;
return off;
}
vlong
setaddr(Sym *s, vlong off, Sym *t)
{
return setaddrplus(s, off, 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
dosymtype(void)
{
Sym *s;
for(s = allsym; s != nil; s = s->allsym) {
if(s->np > 0) {
if(s->type == SBSS)
s->type = SDATA;
if(s->type == SNOPTRBSS)
s->type = SNOPTRDATA;
}
}
}
static int32
symalign(Sym *s)
{
int32 align;
if(s->align != 0)
return s->align;
align = MaxAlign;
while(align > s->size && align > 1)
align >>= 1;
if(align < s->align)
align = s->align;
return align;
}
static vlong
aligndatsize(vlong datsize, Sym *s)
{
return rnd(datsize, symalign(s));
}
// maxalign returns the maximum required alignment for
// the list of symbols s; the list stops when s->type exceeds type.
static int32
maxalign(Sym *s, int type)
{
int32 align, max;
max = 0;
for(; s != S && s->type <= type; s = s->next) {
align = symalign(s);
if(max < align)
max = align;
}
return max;
}
static void
gcaddsym(Sym *gc, Sym *s, vlong off)
{
vlong a;
Sym *gotype;
if(s->size < PtrSize)
return;
if(strcmp(s->name, ".string") == 0)
return;
gotype = s->gotype;
if(gotype != nil) {
//print("gcaddsym: %s %d %s\n", s->name, s->size, gotype->name);
adduintxx(gc, GC_CALL, PtrSize);
adduintxx(gc, off, PtrSize);
addpcrelplus(gc, decodetype_gc(gotype), 3*PtrSize+4);
if(PtrSize == 8)
adduintxx(gc, 0, 4);
} else {
//print("gcaddsym: %s %d <unknown type>\n", s->name, s->size);
for(a = -off&(PtrSize-1); a+PtrSize<=s->size; a+=PtrSize) {
adduintxx(gc, GC_APTR, PtrSize);
adduintxx(gc, off+a, PtrSize);
}
}
}
void
growdatsize(vlong *datsizep, Sym *s)
{
vlong datsize;
datsize = *datsizep;
if(s->size < 0)
diag("negative size (datsize = %lld, s->size = %lld)", datsize, s->size);
if(datsize + s->size < datsize)
diag("symbol too large (datsize = %lld, s->size = %lld)", datsize, s->size);
*datsizep = datsize + s->size;
}
void
dodata(void)
{
int32 n;
vlong datsize;
Section *sect;
Sym *s, *last, **l;
Sym *gcdata1, *gcbss1;
if(debug['v'])
Bprint(&bso, "%5.2f dodata\n", cputime());
Bflush(&bso);
gcdata1 = lookup("gcdata", 0);
gcbss1 = lookup("gcbss", 0);
// size of .data and .bss section. the zero value is later replaced by the actual size of the section.
adduintxx(gcdata1, 0, PtrSize);
adduintxx(gcbss1, 0, PtrSize);
last = nil;
datap = nil;
for(s=allsym; s!=S; s=s->allsym) {
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 > 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.
*
* on darwin, we need the symbol table numbers for dynreloc.
*/
if(HEADTYPE == Hdarwin)
machosymorder();
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;
if(flag_shared) {
for(s=datap; s != nil; s = s->next) {
if(s->rel_ro)
s->type = SDATARELRO;
}
}
datap = listsort(datap, datcmp, offsetof(Sym, next));
/*
* allocate sections. list is sorted by type,
* so we can just walk it for each piece we want to emit.
* segdata is processed before segtext, because we need
* to see all symbols in the .data and .bss sections in order
* to generate garbage collection information.
*/
/* begin segdata */
/* skip symbols belonging to segtext */
s = datap;
for(; s != nil && s->type < SELFSECT; s = s->next)
;
/* writable ELF sections */
datsize = 0;
for(; s != nil && s->type < SNOPTRDATA; s = s->next) {
sect = addsection(&segdata, s->name, 06);
sect->align = symalign(s);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
s->sect = sect;
s->type = SDATA;
s->value = datsize;
growdatsize(&datsize, s);
sect->len = datsize - sect->vaddr;
}
/* pointer-free data */
sect = addsection(&segdata, ".noptrdata", 06);
sect->align = maxalign(s, SDATARELRO-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
lookup("noptrdata", 0)->sect = sect;
lookup("enoptrdata", 0)->sect = sect;
for(; s != nil && s->type < SDATARELRO; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SDATA;
s->value = datsize;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* dynamic relocated rodata */
if(flag_shared) {
sect = addsection(&segdata, ".data.rel.ro", 06);
sect->align = maxalign(s, SDATARELRO);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
lookup("datarelro", 0)->sect = sect;
lookup("edatarelro", 0)->sect = sect;
for(; s != nil && s->type == SDATARELRO; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SDATA;
s->value = datsize;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
}
/* data */
sect = addsection(&segdata, ".data", 06);
sect->align = maxalign(s, SBSS-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
lookup("data", 0)->sect = sect;
lookup("edata", 0)->sect = sect;
for(; s != nil && s->type < SBSS; s = s->next) {
if(s->type == SDATARELRO) {
cursym = s;
diag("unexpected symbol type %d", s->type);
}
s->sect = sect;
s->type = SDATA;
datsize = aligndatsize(datsize, s);
s->value = datsize;
gcaddsym(gcdata1, s, datsize - sect->vaddr); // gc
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
adduintxx(gcdata1, GC_END, PtrSize);
setuintxx(gcdata1, 0, sect->len, PtrSize);
/* bss */
sect = addsection(&segdata, ".bss", 06);
sect->align = maxalign(s, SNOPTRBSS-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
lookup("bss", 0)->sect = sect;
lookup("ebss", 0)->sect = sect;
for(; s != nil && s->type < SNOPTRBSS; s = s->next) {
s->sect = sect;
datsize = aligndatsize(datsize, s);
s->value = datsize;
gcaddsym(gcbss1, s, datsize - sect->vaddr); // gc
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
adduintxx(gcbss1, GC_END, PtrSize);
setuintxx(gcbss1, 0, sect->len, PtrSize);
/* pointer-free bss */
sect = addsection(&segdata, ".noptrbss", 06);
sect->align = maxalign(s, SNOPTRBSS);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
lookup("noptrbss", 0)->sect = sect;
lookup("enoptrbss", 0)->sect = sect;
for(; s != nil && s->type == SNOPTRBSS; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->value = datsize;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
lookup("end", 0)->sect = sect;
// 6g uses 4-byte relocation offsets, so the entire segment must fit in 32 bits.
if(datsize != (uint32)datsize) {
diag("data or bss segment too large");
}
if(iself && linkmode == LinkExternal && s != nil && s->type == STLSBSS && HEADTYPE != Hopenbsd) {
sect = addsection(&segdata, ".tbss", 06);
sect->align = PtrSize;
sect->vaddr = 0;
datsize = 0;
for(; s != nil && s->type == STLSBSS; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->value = datsize;
growdatsize(&datsize, s);
}
sect->len = datsize;
}
if(s != nil) {
cursym = nil;
diag("unexpected symbol type %d for %s", s->type, s->name);
}
/* we finished segdata, begin segtext */
s = datap;
/* read-only data */
sect = addsection(&segtext, ".rodata", 04);
sect->align = maxalign(s, STYPELINK-1);
sect->vaddr = 0;
lookup("rodata", 0)->sect = sect;
lookup("erodata", 0)->sect = sect;
datsize = 0;
for(; s != nil && s->type < STYPELINK; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SRODATA;
s->value = datsize;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* typelink */
sect = addsection(&segtext, ".typelink", 04);
sect->align = maxalign(s, STYPELINK);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
lookup("typelink", 0)->sect = sect;
lookup("etypelink", 0)->sect = sect;
for(; s != nil && s->type == STYPELINK; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SRODATA;
s->value = datsize;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* gosymtab */
sect = addsection(&segtext, ".gosymtab", 04);
sect->align = maxalign(s, SPCLNTAB-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
lookup("symtab", 0)->sect = sect;
lookup("esymtab", 0)->sect = sect;
for(; s != nil && s->type < SPCLNTAB; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SRODATA;
s->value = datsize;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* gopclntab */
sect = addsection(&segtext, ".gopclntab", 04);
sect->align = maxalign(s, SELFROSECT-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
lookup("pclntab", 0)->sect = sect;
lookup("epclntab", 0)->sect = sect;
for(; s != nil && s->type < SELFROSECT; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SRODATA;
s->value = datsize;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* read-only ELF, Mach-O sections */
for(; s != nil && s->type < SELFSECT; s = s->next) {
sect = addsection(&segtext, s->name, 04);
sect->align = symalign(s);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
s->sect = sect;
s->type = SRODATA;
s->value = datsize;
growdatsize(&datsize, s);
sect->len = datsize - sect->vaddr;
}
// 6g uses 4-byte relocation offsets, so the entire segment must fit in 32 bits.
if(datsize != (uint32)datsize) {
diag("text segment too large");
}
/* number the sections */
n = 1;
for(sect = segtext.sect; sect != nil; sect = sect->next)
sect->extnum = n++;
for(sect = segdata.sect; sect != nil; sect = sect->next)
sect->extnum = n++;
}
// 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;
sect->align = FuncAlign;
lookup("text", 0)->sect = sect;
lookup("etext", 0)->sect = sect;
va = INITTEXT;
sect->vaddr = va;
for(sym = textp; sym != nil; sym = sym->next) {
sym->sect = sect;
if(sym->type & SSUB)
continue;
if(sym->align != 0)
va = rnd(va, sym->align);
else if(sym->text != P)
va = rnd(va, FuncAlign);
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, *symtab, *pclntab, *noptr, *bss, *noptrbss, *datarelro;
Section *typelink;
Sym *sym, *sub;
uvlong va;
vlong vlen;
va = INITTEXT;
segtext.rwx = 05;
segtext.vaddr = va;
segtext.fileoff = HEADR;
for(s=segtext.sect; s != nil; s=s->next) {
va = rnd(va, s->align);
s->vaddr = va;
va += s->len;
}
segtext.len = va - INITTEXT;
segtext.filelen = segtext.len;
va = rnd(va, INITRND);
segdata.rwx = 06;
segdata.vaddr = va;
segdata.fileoff = va - segtext.vaddr + segtext.fileoff;
segdata.filelen = 0;
if(HEADTYPE == Hwindows)
segdata.fileoff = segtext.fileoff + rnd(segtext.len, PEFILEALIGN);
if(HEADTYPE == Hplan9x64 || HEADTYPE == Hplan9x32)
segdata.fileoff = segtext.fileoff + segtext.filelen;
data = nil;
noptr = nil;
bss = nil;
noptrbss = nil;
datarelro = nil;
for(s=segdata.sect; s != nil; s=s->next) {
vlen = s->len;
if(s->next)
vlen = s->next->vaddr - s->vaddr;
s->vaddr = va;
va += vlen;
segdata.len = va - segdata.vaddr;
if(strcmp(s->name, ".data") == 0)
data = s;
if(strcmp(s->name, ".noptrdata") == 0)
noptr = s;
if(strcmp(s->name, ".bss") == 0)
bss = s;
if(strcmp(s->name, ".noptrbss") == 0)
noptrbss = s;
if(strcmp(s->name, ".data.rel.ro") == 0)
datarelro = s;
}
segdata.filelen = bss->vaddr - segdata.vaddr;
text = segtext.sect;
rodata = text->next;
typelink = rodata->next;
symtab = typelink->next;
pclntab = symtab->next;
for(sym = datap; sym != nil; sym = sym->next) {
cursym = sym;
if(sym->type < SNOPTRDATA)
sym->value += rodata->vaddr;
else
sym->value += segdata.sect->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("typelink", SRODATA, typelink->vaddr);
xdefine("etypelink", SRODATA, typelink->vaddr + typelink->len);
if(datarelro != nil) {
xdefine("datarelro", SRODATA, datarelro->vaddr);
xdefine("edatarelro", SRODATA, datarelro->vaddr + datarelro->len);
}
sym = lookup("gcdata", 0);
xdefine("egcdata", SRODATA, symaddr(sym) + sym->size);
lookup("egcdata", 0)->sect = sym->sect;
sym = lookup("gcbss", 0);
xdefine("egcbss", SRODATA, symaddr(sym) + sym->size);
lookup("egcbss", 0)->sect = sym->sect;
xdefine("symtab", SRODATA, symtab->vaddr);
xdefine("esymtab", SRODATA, symtab->vaddr + symtab->len);
xdefine("pclntab", SRODATA, pclntab->vaddr);
xdefine("epclntab", SRODATA, pclntab->vaddr + pclntab->len);
xdefine("noptrdata", SNOPTRDATA, noptr->vaddr);
xdefine("enoptrdata", SNOPTRDATA, noptr->vaddr + noptr->len);
xdefine("bss", SBSS, bss->vaddr);
xdefine("ebss", SBSS, bss->vaddr + bss->len);
xdefine("data", SDATA, data->vaddr);
xdefine("edata", SDATA, data->vaddr + data->len);
xdefine("noptrbss", SNOPTRBSS, noptrbss->vaddr);
xdefine("enoptrbss", SNOPTRBSS, noptrbss->vaddr + noptrbss->len);
xdefine("end", SBSS, segdata.vaddr + segdata.len);
}
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