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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 "../../runtime/mgc0.h"
void dynreloc(void);
/*
* divide-and-conquer list-link
* sort of LSym* structures.
* Used for the data block.
*/
int
datcmp(LSym *s1, LSym *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);
}
LSym*
listsort(LSym *l, int (*cmp)(LSym*, LSym*), int off)
{
LSym *l1, *l2, *le;
#define NEXT(l) (*(LSym**)((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
}
void
relocsym(LSym *s)
{
Reloc *r;
LSym *rs;
int32 i, off, siz, fl;
vlong o;
uchar *cast;
ctxt->cursym = s;
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 | SHIDDEN)) == 0 || (r->sym->type & SMASK) == SXREF)) {
diag("%s: not defined", r->sym->name);
continue;
}
if(r->type >= 256)
continue;
if(r->siz == 0) // informational relocation - no work to do
continue;
// Solaris needs the ability to reference dynimport symbols.
if(HEADTYPE != Hsolaris && 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);
// Android emulates runtime.tlsg as a regular variable.
if (r->type == R_TLS && strcmp(goos, "android") == 0)
r->type = R_ADDR;
switch(r->type) {
default:
o = 0;
if(archreloc(r, s, &o) < 0)
diag("unknown reloc %d", r->type);
break;
case R_TLS:
if(linkmode == LinkInternal && iself && thechar == '5') {
// On ELF ARM, the thread pointer is 8 bytes before
// the start of the thread-local data block, so add 8
// to the actual TLS offset (r->sym->value).
// This 8 seems to be a fundamental constant of
// ELF on ARM (or maybe Glibc on ARM); it is not
// related to the fact that our own TLS storage happens
// to take up 8 bytes.
o = 8 + r->sym->value;
break;
}
r->done = 0;
o = 0;
if(thechar != '6')
o = r->add;
break;
case R_TLS_LE:
if(linkmode == LinkExternal && iself && HEADTYPE != Hopenbsd) {
r->done = 0;
r->sym = ctxt->tlsg;
r->xsym = ctxt->tlsg;
r->xadd = r->add;
o = 0;
if(thechar != '6')
o = r->add;
break;
}
o = ctxt->tlsoffset + r->add;
break;
case R_TLS_IE:
if(linkmode == LinkExternal && iself && HEADTYPE != Hopenbsd) {
r->done = 0;
r->sym = ctxt->tlsg;
r->xsym = ctxt->tlsg;
r->xadd = r->add;
o = 0;
if(thechar != '6')
o = r->add;
break;
}
if(iself || ctxt->headtype == Hplan9)
o = ctxt->tlsoffset + r->add;
else if(ctxt->headtype == Hwindows)
o = r->add;
else
sysfatal("unexpected R_TLS_IE relocation for %s", headstr(ctxt->headtype));
break;
case R_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->type != SDYNIMPORT && 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", headstring);
}
break;
}
o = symaddr(r->sym) + r->add;
// On amd64, 4-byte offsets will be sign-extended, so it is impossible to
// access more than 2GB of static data; fail at link time is better than
// fail at runtime. See http://golang.org/issue/7980.
// Instead of special casing only amd64, we treat this as an error on all
// 64-bit architectures so as to be future-proof.
if((int32)o < 0 && PtrSize > 4 && siz == 4) {
diag("non-pc-relative relocation address is too big: %#llux", o);
errorexit();
}
break;
case R_CALL:
case R_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 != ctxt->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->type != SDYNIMPORT && 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(r->type == R_CALL) {
if(rs->type != SHOSTOBJ)
o += symaddr(rs) - rs->sect->vaddr;
o -= r->off; // relative to section offset, not symbol
} else {
o += r->siz;
}
} else {
diag("unhandled pcrel relocation for %s", headstring);
}
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 R_SIZE:
o = r->sym->size + r->add;
break;
}
//print("relocate %s %#llux (%#llux+%#llux, size %d) => %s %#llux +%#llx [%llx]\n", s->name, (uvlong)(s->value+off), (uvlong)s->value, (uvlong)r->off, r->siz, r->sym ? r->sym->name : "<nil>", (uvlong)symaddr(r->sym), (vlong)r->add, (vlong)o);
switch(siz) {
default:
ctxt->cursym = s;
diag("bad reloc size %#ux for %s", siz, r->sym->name);
case 1:
// TODO(rsc): Remove.
s->p[off] = (int8)o;
break;
case 4:
if(r->type == R_PCREL || r->type == R_CALL) {
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)
{
LSym *s;
if(debug['v'])
Bprint(&bso, "%5.2f reloc\n", cputime());
Bflush(&bso);
for(s=ctxt->textp; s!=S; s=s->next)
relocsym(s);
for(s=datap; s!=S; s=s->next)
relocsym(s);
}
void
dynrelocsym(LSym *s)
{
Reloc *r;
if(HEADTYPE == Hwindows) {
LSym *rel, *targ;
rel = linklookup(ctxt, ".rel", 0);
if(s == rel)
return;
for(r=s->r; r<s->r+s->nr; r++) {
targ = r->sym;
if(targ == nil)
continue;
if(!targ->reachable)
diag("internal inconsistency: dynamic symbol %s is not reachable.", targ->name);
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(ctxt, rel, 0xff);
adduint8(ctxt, rel, 0x25);
addaddr(ctxt, rel, targ);
adduint8(ctxt, rel, 0x90);
adduint8(ctxt, rel, 0x90);
} else {
adduint8(ctxt, rel, 0xff);
adduint8(ctxt, rel, 0x24);
adduint8(ctxt, rel, 0x25);
addaddrplus4(ctxt, rel, targ, 0);
adduint8(ctxt, rel, 0x90);
}
} else if(r->sym->plt >= 0) {
r->sym = rel;
r->add = targ->plt;
}
}
return;
}
for(r=s->r; r<s->r+s->nr; r++) {
if(r->sym != S && r->sym->type == SDYNIMPORT || r->type >= 256) {
if(r->sym != S && !r->sym->reachable)
diag("internal inconsistency: dynamic symbol %s is not reachable.", r->sym->name);
adddynrel(s, r);
}
}
}
void
dynreloc(void)
{
LSym *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=ctxt->textp; s!=S; s=s->next)
dynrelocsym(s);
for(s=datap; s!=S; s=s->next)
dynrelocsym(s);
if(iself)
elfdynhash();
}
static void
blk(LSym *start, int64 addr, int64 size)
{
LSym *sym;
int64 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;
ctxt->cursym = sym;
if(sym->value < addr) {
diag("phase error: addr=%#llx but sym=%#llx type=%d", (vlong)addr, (vlong)sym->value, sym->type);
errorexit();
}
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();
}
if(sym->value+sym->size >= eaddr)
break;
}
for(; addr < eaddr; addr++)
cput(0);
cflush();
}
void
codeblk(int64 addr, int64 size)
{
LSym *sym;
int64 eaddr, n;
uchar *q;
if(debug['a'])
Bprint(&bso, "codeblk [%#x,%#x) at offset %#llx\n", addr, addr+size, cpos());
blk(ctxt->textp, addr, size);
/* again for printing */
if(!debug['a'])
return;
for(sym = ctxt->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");
}
Bprint(&bso, "%.6llux\t%-20s\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;
}
if(addr < eaddr) {
Bprint(&bso, "%-20s %.8llux|", "_", (vlong)addr);
for(; addr < eaddr; addr++)
Bprint(&bso, " %.2ux", 0);
}
Bflush(&bso);
}
void
datblk(int64 addr, int64 size)
{
LSym *sym;
int64 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 R_ADDR:
typ = "addr";
break;
case R_PCREL:
typ = "pcrel";
break;
case R_CALL:
typ = "call";
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)
{
LSym *s, *sp;
char *p;
uchar reachable;
p = smprint("%s.str", name);
sp = linklookup(ctxt, p, 0);
free(p);
addstring(sp, value);
sp->type = SRODATA;
s = linklookup(ctxt, name, 0);
s->size = 0;
s->dupok = 1;
reachable = s->reachable;
addaddr(ctxt, s, sp);
adduintxx(ctxt, s, strlen(value), PtrSize);
// addstring, addaddr, etc., mark the symbols as reachable.
// In this case that is not necessarily true, so stick to what
// we know before entering this function.
s->reachable = reachable;
sp->reachable = reachable;
}
vlong
addstring(LSym *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(ctxt, s, r+n);
memmove(s->p+r, str, n);
s->size += n;
return r;
}
void
dosymtype(void)
{
LSym *s;
for(s = ctxt->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(LSym *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, LSym *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(LSym *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;
}
// Helper object for building GC type programs.
typedef struct ProgGen ProgGen;
struct ProgGen
{
LSym* s;
int32 datasize;
uint8 data[256/PointersPerByte];
vlong pos;
};
static void
proggeninit(ProgGen *g, LSym *s)
{
g->s = s;
g->datasize = 0;
g->pos = 0;
memset(g->data, 0, sizeof(g->data));
}
static void
proggenemit(ProgGen *g, uint8 v)
{
adduint8(ctxt, g->s, v);
}
// Writes insData block from g->data.
static void
proggendataflush(ProgGen *g)
{
int32 i, s;
if(g->datasize == 0)
return;
proggenemit(g, insData);
proggenemit(g, g->datasize);
s = (g->datasize + PointersPerByte - 1)/PointersPerByte;
for(i = 0; i < s; i++)
proggenemit(g, g->data[i]);
g->datasize = 0;
memset(g->data, 0, sizeof(g->data));
}
static void
proggendata(ProgGen *g, uint8 d)
{
g->data[g->datasize/PointersPerByte] |= d << ((g->datasize%PointersPerByte)*BitsPerPointer);
g->datasize++;
if(g->datasize == 255)
proggendataflush(g);
}
// Skip v bytes due to alignment, etc.
static void
proggenskip(ProgGen *g, vlong off, vlong v)
{
vlong i;
for(i = off; i < off+v; i++) {
if((i%PtrSize) == 0)
proggendata(g, BitsScalar);
}
}
// Emit insArray instruction.
static void
proggenarray(ProgGen *g, vlong len)
{
int32 i;
proggendataflush(g);
proggenemit(g, insArray);
for(i = 0; i < PtrSize; i++, len >>= 8)
proggenemit(g, len);
}
static void
proggenarrayend(ProgGen *g)
{
proggendataflush(g);
proggenemit(g, insArrayEnd);
}
static void
proggenfini(ProgGen *g, vlong size)
{
proggenskip(g, g->pos, size - g->pos);
proggendataflush(g);
proggenemit(g, insEnd);
}
// This function generates GC pointer info for global variables.
static void
proggenaddsym(ProgGen *g, LSym *s)
{
LSym *gcprog;
uint8 *mask;
vlong i, size;
if(s->size == 0)
return;
// Skip alignment hole from the previous symbol.
proggenskip(g, g->pos, s->value - g->pos);
g->pos += s->value - g->pos;
// The test for names beginning with . here is meant
// to keep .dynamic and .dynsym from turning up as
// conservative symbols. They should be marked SELFSECT
// and not SDATA, but sometimes that doesn't happen.
// Leave debugging the SDATA issue for the Go rewrite.
if(s->gotype == nil && s->size >= PtrSize && s->name[0] != '.') {
// conservative scan
diag("missing Go type information for global symbol: %s size %d", s->name, (int)s->size);
if((s->size%PtrSize) || (g->pos%PtrSize))
diag("proggenaddsym: unaligned conservative symbol %s: size=%lld pos=%lld",
s->name, s->size, g->pos);
size = (s->size+PtrSize-1)/PtrSize*PtrSize;
if(size < 32*PtrSize) {
// Emit small symbols as data.
for(i = 0; i < size/PtrSize; i++)
proggendata(g, BitsPointer);
} else {
// Emit large symbols as array.
proggenarray(g, size/PtrSize);
proggendata(g, BitsPointer);
proggenarrayend(g);
}
g->pos = s->value + size;
} else if(s->gotype == nil || decodetype_noptr(s->gotype) || s->size < PtrSize || s->name[0] == '.') {
// no scan
if(s->size < 32*PtrSize) {
// Emit small symbols as data.
// This case also handles unaligned and tiny symbols, so tread carefully.
for(i = s->value; i < s->value+s->size; i++) {
if((i%PtrSize) == 0)
proggendata(g, BitsScalar);
}
} else {
// Emit large symbols as array.
if((s->size%PtrSize) || (g->pos%PtrSize))
diag("proggenaddsym: unaligned noscan symbol %s: size=%lld pos=%lld",
s->name, s->size, g->pos);
proggenarray(g, s->size/PtrSize);
proggendata(g, BitsScalar);
proggenarrayend(g);
}
g->pos = s->value + s->size;
} else if(decodetype_usegcprog(s->gotype)) {
// gc program, copy directly
proggendataflush(g);
gcprog = decodetype_gcprog(s->gotype);
size = decodetype_size(s->gotype);
if((size%PtrSize) || (g->pos%PtrSize))
diag("proggenaddsym: unaligned gcprog symbol %s: size=%lld pos=%lld",
s->name, s->size, g->pos);
for(i = 0; i < gcprog->np-1; i++)
proggenemit(g, gcprog->p[i]);
g->pos = s->value + size;
} else {
// gc mask, it's small so emit as data
mask = decodetype_gcmask(s->gotype);
size = decodetype_size(s->gotype);
if((size%PtrSize) || (g->pos%PtrSize))
diag("proggenaddsym: unaligned gcmask symbol %s: size=%lld pos=%lld",
s->name, s->size, g->pos);
for(i = 0; i < size; i += PtrSize)
proggendata(g, (mask[i/PtrSize/2]>>((i/PtrSize%2)*4+2))&BitsMask);
g->pos = s->value + size;
}
}
void
growdatsize(vlong *datsizep, LSym *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;
Segment *segro;
LSym *s, *last, **l;
LSym *gcdata, *gcbss;
ProgGen gen;
if(debug['v'])
Bprint(&bso, "%5.2f dodata\n", cputime());
Bflush(&bso);
last = nil;
datap = nil;
for(s=ctxt->allsym; s!=S; s=s->allsym) {
if(!s->reachable || s->special)
continue;
if(STEXT < s->type && s->type < SXREF) {
if(s->onlist)
sysfatal("symbol %s listed multiple times", s->name);
s->onlist = 1;
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;
datap = listsort(datap, datcmp, offsetof(LSym, 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 - sect->vaddr;
growdatsize(&datsize, s);
sect->len = datsize - sect->vaddr;
}
/* pointer-free data */
sect = addsection(&segdata, ".noptrdata", 06);
sect->align = maxalign(s, SINITARR-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
linklookup(ctxt, "runtime.noptrdata", 0)->sect = sect;
linklookup(ctxt, "runtime.enoptrdata", 0)->sect = sect;
for(; s != nil && s->type < SINITARR; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SDATA;
s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* shared library initializer */
if(flag_shared) {
sect = addsection(&segdata, ".init_array", 06);
sect->align = maxalign(s, SINITARR);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
for(; s != nil && s->type == SINITARR; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->value = datsize - sect->vaddr;
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;
linklookup(ctxt, "runtime.data", 0)->sect = sect;
linklookup(ctxt, "runtime.edata", 0)->sect = sect;
gcdata = linklookup(ctxt, "runtime.gcdata", 0);
proggeninit(&gen, gcdata);
for(; s != nil && s->type < SBSS; s = s->next) {
if(s->type == SINITARR) {
ctxt->cursym = s;
diag("unexpected symbol type %d", s->type);
}
s->sect = sect;
s->type = SDATA;
datsize = aligndatsize(datsize, s);
s->value = datsize - sect->vaddr;
proggenaddsym(&gen, s); // gc
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
proggenfini(&gen, sect->len); // gc
/* bss */
sect = addsection(&segdata, ".bss", 06);
sect->align = maxalign(s, SNOPTRBSS-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
linklookup(ctxt, "runtime.bss", 0)->sect = sect;
linklookup(ctxt, "runtime.ebss", 0)->sect = sect;
gcbss = linklookup(ctxt, "runtime.gcbss", 0);
proggeninit(&gen, gcbss);
for(; s != nil && s->type < SNOPTRBSS; s = s->next) {
s->sect = sect;
datsize = aligndatsize(datsize, s);
s->value = datsize - sect->vaddr;
proggenaddsym(&gen, s); // gc
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
proggenfini(&gen, sect->len); // gc
/* pointer-free bss */
sect = addsection(&segdata, ".noptrbss", 06);
sect->align = maxalign(s, SNOPTRBSS);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
linklookup(ctxt, "runtime.noptrbss", 0)->sect = sect;
linklookup(ctxt, "runtime.enoptrbss", 0)->sect = sect;
for(; s != nil && s->type == SNOPTRBSS; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
linklookup(ctxt, "runtime.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 - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize;
} else {
// Might be internal linking but still using cgo.
// In that case, the only possible STLSBSS symbol is runtime.tlsg.
// Give it offset 0, because it's the only thing here.
if(s != nil && s->type == STLSBSS && strcmp(s->name, "runtime.tlsg") == 0) {
s->value = 0;
s = s->next;
}
}
if(s != nil) {
ctxt->cursym = nil;
diag("unexpected symbol type %d for %s", s->type, s->name);
}
/*
* We finished data, begin read-only data.
* Not all systems support a separate read-only non-executable data section.
* ELF systems do.
* OS X and Plan 9 do not.
* Windows PE may, but if so we have not implemented it.
* And if we're using external linking mode, the point is moot,
* since it's not our decision; that code expects the sections in
* segtext.
*/
if(iself && linkmode == LinkInternal)
segro = &segrodata;
else
segro = &segtext;
s = datap;
datsize = 0;
/* read-only executable ELF, Mach-O sections */
for(; s != nil && s->type < STYPE; 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 - sect->vaddr;
growdatsize(&datsize, s);
sect->len = datsize - sect->vaddr;
}
/* read-only data */
sect = addsection(segro, ".rodata", 04);
sect->align = maxalign(s, STYPELINK-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = 0;
linklookup(ctxt, "runtime.rodata", 0)->sect = sect;
linklookup(ctxt, "runtime.erodata", 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 - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* typelink */
sect = addsection(segro, ".typelink", 04);
sect->align = maxalign(s, STYPELINK);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
linklookup(ctxt, "runtime.typelink", 0)->sect = sect;
linklookup(ctxt, "runtime.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 - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* gosymtab */
sect = addsection(segro, ".gosymtab", 04);
sect->align = maxalign(s, SPCLNTAB-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
linklookup(ctxt, "runtime.symtab", 0)->sect = sect;
linklookup(ctxt, "runtime.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 - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* gopclntab */
sect = addsection(segro, ".gopclntab", 04);
sect->align = maxalign(s, SELFROSECT-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
linklookup(ctxt, "runtime.pclntab", 0)->sect = sect;
linklookup(ctxt, "runtime.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 - sect->vaddr;
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(segro, s->name, 04);
sect->align = symalign(s);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
s->sect = sect;
s->type = SRODATA;
s->value = datsize - sect->vaddr;
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("read-only data segment too large");
}
/* number the sections */
n = 1;
for(sect = segtext.sect; sect != nil; sect = sect->next)
sect->extnum = n++;
for(sect = segrodata.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;
Section *sect;
LSym *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;
linklookup(ctxt, "runtime.text", 0)->sect = sect;
linklookup(ctxt, "runtime.etext", 0)->sect = sect;
va = INITTEXT;
sect->vaddr = va;
for(sym = ctxt->textp; sym != nil; sym = sym->next) {
sym->sect = sect;
if(sym->type & SSUB)
continue;
if(sym->align != 0)
va = rnd(va, sym->align);
else
va = rnd(va, funcalign);
sym->value = 0;
for(sub = sym; sub != S; sub = sub->sub)
sub->value += va;
if(sym->size == 0 && sym->sub != S)
ctxt->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;
Section *typelink;
LSym *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;
if(HEADTYPE == Hnacl)
va += 32; // room for the "halt sled"
if(segrodata.sect != nil) {
// align to page boundary so as not to mix
// rodata and executable text.
va = rnd(va, INITRND);
segrodata.rwx = 04;
segrodata.vaddr = va;
segrodata.fileoff = va - segtext.vaddr + segtext.fileoff;
segrodata.filelen = 0;
for(s=segrodata.sect; s != nil; s=s->next) {
va = rnd(va, s->align);
s->vaddr = va;
va += s->len;
}
segrodata.len = va - segrodata.vaddr;
segrodata.filelen = segrodata.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 == Hplan9)
segdata.fileoff = segtext.fileoff + segtext.filelen;
data = nil;
noptr = nil;
bss = nil;
noptrbss = 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;
}
segdata.filelen = bss->vaddr - segdata.vaddr;
text = segtext.sect;
if(segrodata.sect)
rodata = segrodata.sect;
else
rodata = text->next;
typelink = rodata->next;
symtab = typelink->next;
pclntab = symtab->next;
for(sym = datap; sym != nil; sym = sym->next) {
ctxt->cursym = sym;
if(sym->sect != nil)
sym->value += sym->sect->vaddr;
for(sub = sym->sub; sub != nil; sub = sub->sub)
sub->value += sym->value;
}
xdefine("runtime.text", STEXT, text->vaddr);
xdefine("runtime.etext", STEXT, text->vaddr + text->len);
xdefine("runtime.rodata", SRODATA, rodata->vaddr);
xdefine("runtime.erodata", SRODATA, rodata->vaddr + rodata->len);
xdefine("runtime.typelink", SRODATA, typelink->vaddr);
xdefine("runtime.etypelink", SRODATA, typelink->vaddr + typelink->len);
sym = linklookup(ctxt, "runtime.gcdata", 0);
xdefine("runtime.egcdata", SRODATA, symaddr(sym) + sym->size);
linklookup(ctxt, "runtime.egcdata", 0)->sect = sym->sect;
sym = linklookup(ctxt, "runtime.gcbss", 0);
xdefine("runtime.egcbss", SRODATA, symaddr(sym) + sym->size);
linklookup(ctxt, "runtime.egcbss", 0)->sect = sym->sect;
xdefine("runtime.symtab", SRODATA, symtab->vaddr);
xdefine("runtime.esymtab", SRODATA, symtab->vaddr + symtab->len);
xdefine("runtime.pclntab", SRODATA, pclntab->vaddr);
xdefine("runtime.epclntab", SRODATA, pclntab->vaddr + pclntab->len);
xdefine("runtime.noptrdata", SNOPTRDATA, noptr->vaddr);
xdefine("runtime.enoptrdata", SNOPTRDATA, noptr->vaddr + noptr->len);
xdefine("runtime.bss", SBSS, bss->vaddr);
xdefine("runtime.ebss", SBSS, bss->vaddr + bss->len);
xdefine("runtime.data", SDATA, data->vaddr);
xdefine("runtime.edata", SDATA, data->vaddr + data->len);
xdefine("runtime.noptrbss", SNOPTRBSS, noptrbss->vaddr);
xdefine("runtime.enoptrbss", SNOPTRBSS, noptrbss->vaddr + noptrbss->len);
xdefine("runtime.end", SBSS, segdata.vaddr + segdata.len);
}
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