// 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 int32
aligndatsize(int32 datsize, Sym *s)
{
return rnd(datsize, symalign(s));
}
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++;
}
void
dodata(void)
{
int32 n, datsize;
Section *sect;
Sym *s, *last, **l;
Sym *gcdata1, *gcbss1;
if(debug['v'])
Bprint(&bso, "%5.2f dodata\n", cputime());
Bflush(&bso);
// define garbage collection symbols
gcdata1 = lookup("gcdata", 0);
gcdata1->type = STYPE;
gcdata1->reachable = 1;
gcbss1 = lookup("gcbss", 0);
gcbss1->type = STYPE;
gcbss1->reachable = 1;
// 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;
datsize += s->size;
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;
datsize += s->size;
}
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;
datsize += s->size;
}
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
datsize += s->size;
}
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
datsize += s->size;
}
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 = s->next) {
if(s->type > SNOPTRBSS) {
cursym = s;
diag("unexpected symbol type %d", s->type);
}
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->value = datsize;
datsize += s->size;
}
sect->len = datsize - sect->vaddr;
lookup("end", 0)->sect = sect;
/* we finished segdata, begin segtext */
s = datap;
datsize = 0;
/* 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;
datsize += s->size;
}
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;
datsize += s->size;
}
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;
datsize += s->size;
}
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;
datsize += s->size;
}
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;
datsize += s->size;
sect->len = datsize - sect->vaddr;
}
/* 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++;
}
static vlong
aligndatsize(vlong datsize, LSym *s)
{
return rnd(datsize, symalign(s));
}