[Patch mach-o, indirect symbols 1/2] support indirect symbols in mach-o.

[Iain Sandoe]

Hi Tristan,

On 4 Jan 2012, at 08:26, Tristan Gingold wrote:
>>> Well, OK, the simplest solution is to keep the code mechanism as  
>>> is - but to use a new/different flag to  
>>> signal .indirect_symbols .. the sorting etc. doesn't really need  
>>> to change (just the bits using IS_MACHO_INDIRECT - which needs to  
>>> utilize a different flag) .. any suggestions about the Right Flag   
>>> (or a new one)?
>>>
>>> The GAS end will need amending to use a SET_MACHO_INDIRECT .. but  
>>> that's also not too too bad...
>>
>> So, here's a revised patch -
>> that uses (BSF_INDIRECT | BSF_SYNTHETIC) as the 'signal' from gas - 
>> > bfd that the symbol is a mach_o .indirect_symbol
>> these symbols are also unnamed (could be used as a third key if  
>> there is a meaning - can't think of one tonight - to (BSF_INDIRECT  
>> | BSF_SYNTHETIC)).
>
> I think we should really moving .indirect_symbols out of the symtab  
> for the following reasons:
> 1) there is no natural flags for them (BSF_INDIRECT | BSF_SYNTHETIC  
> is not fully correct)
> 2) they are anonymous (so it doesn't make sense to create a symbol  
> for them)
> 3) they aren't physically in the symtab
> 4) they're values are well defined.
> 5) there is a symmetry violation: when we read a mach-o file, we  
> don't create symbol for .indirect_symbol, but we will need symbols  
> to create .indirect_symbol.  This will lead to trouble for objcopy  
> and co.
> If you don't agree, please argue!

Those seem good reasons to me too.

So .. what about a new obstack for these in obj-macho.c?
and, I suppose, a private interface for passing them to BFD.

===

I'll repost the symbol quals patch if you like - since there's quite a  
lot to remove (or are you OK with me removing and applying?)

>> +  do
>> +    {
>> +      name = input_line_pointer;
>> +      c = get_symbol_end ();
>> +      symbolP = symbol_find_or_make (name);
>> +      err = obj_mach_o_set_symbol_qualifier (symbolP, ntype);
>> +      *input_line_pointer = c;
>> +      if (err)
>> +	break;
>
> Do we need to break in case of error ?


... I'm not a fan of a flurry of errors for one typo ..
(but I suppose we should also do an 'ignore_rest_of_Line' as well)

I'll remove it for now, and we can see how that works out.

thanks for reviewing!
Iain