[LLVMdev] [lld] TBSS wrong size

[Adhemerval Zanella]

Hi,

I am tracking some TLS issues with lld and found that it is
generating wrong tbss size for case where multiple modules
have non initialized threads variables.  For instance:

-- t0.c --

__thread int x0;
__thread int x1;
__thread int x2;

extern __thread int e0;
extern __thread int e1;
extern __thread int e2;
extern __thread int e3;

int foo0 ()
{
  return x0;
}

int main ()
{
  return x0;
}

-- t1.c --

__thread int e0;
__thread int e1;
__thread int e2;
__thread int e3;

---

lld is generating (for aarch64):

  [14] .tbss             NOBITS           0000000000401000  00001000
       0000000000000010  0000000000000000 WAT       0     0     4

Where is just taking in consideration the largest tbss segment, not all
from all objects.  ld generates a correct output:

  [17] .tbss             NOBITS           0000000000410dec  00000dec
       000000000000001c  0000000000000000 WAT       0     0     4

My initial idea is that 'lib/ReaderWriter/ELF/SegmentChunks.cpp' / 
Segment<ELFT>::assignVirtualAddress is setting wrong slice values, however
playing with this I could not find a correct logic to handle the TBSS.

Any ideas where lld is possible messing the TBSS segments sizes?