Shared Libraries [was Re: D 1.076 and 2.061 release]

[John Colvin]

On Wednesday, 9 January 2013 at 10:38:33 UTC, Walter Bright wrote:
> On 1/9/2013 2:28 AM, Jacob Carlborg wrote:
>> On 2013-01-09 11:26, Jacob Carlborg wrote:
>>
>>> I think it sounds like that but I don't know. I'm just trying 
>>> to figure
>>> out how TLS is implemented on Mac OS X 10.7+.
>>
>> Also, there's nothing else that calls this tlv_get_addr 
>> function or the thunk so
>> I'm guessing it's the compiler that calls it.
>
> Watcha do is something like this:
>
> __thread int x;
> int foo() { return x; }
>
> Compile, disassemble, and look at the code generated and the 
> fixup records. Then there's no need to guess :-)

Surely __thread is redundant there, seeing as x will be TLS by 
default?

I tried disassembling this on os x 10.7.5

otool (the default tool for this on os x) just gave me this:

     tls_test.o:
     indirect symbol table offset is past end of file
     (__TEXT,__text) section

It couldn't see any instructions at all.

gdb disas gives this:

     0x0000000000000024 <D8tls_test3fooFZi+0>:	push   rbp
     0x0000000000000025 <D8tls_test3fooFZi+1>:	mov    rbp,rsp
     0x0000000000000028 <D8tls_test3fooFZi+4>:	mov    rdi,QWORD 
PTR [rip+0x0]        # 0x30 <D8tls_test3fooFZi+12>
     0x0000000000000030 <D8tls_test3fooFZi+12>:	call   0x35 
<D8tls_test3fooFZi+17>
     0x0000000000000035 <D8tls_test3fooFZi+17>:	mov    eax,DWORD 
PTR [rax]
     0x0000000000000037 <D8tls_test3fooFZi+19>:	pop    rbp
     0x0000000000000038 <D8tls_test3fooFZi+20>:	ret