dmd's linking order

[Mike Wey]

On 04/11/2012 09:54 PM, eles wrote:
>> if you tried to link:
>>
>> gcc my_program.o -lB -lA (so, in reverse order)
>
> read:
>
> gcc my_program.o -lB -lA (so, in unnatural order)
>
>>
>> this looked a bit like:
>>
>> gcc my_program.o -lA -lB
>
> read:
>
> "it looked like the order is arbitrary"
>
>>
>> BUT what really happened was that the true link command was now:
>>
>> gcc my_program.o -lA -lB -lC -lB
>
> read:
>
> gcc my_program.o -lB -lA -lB -lC (so that the symbols of libA *were*
> resolved)
>
>>
>> where the "-lA -lB -lC" is the expansion of the previous "-lA".
>
>
>

And to tell ld to not depend on the order in which the libs are 
specifies, you can use --start-group and --end-group.

 From the ld man page:

--start-group archives --end-group
     The archives should be a list of archive files.  They may be either
     explicit file names, or -l options.

     The specified archives are searched repeatedly until no new
     undefined references are created.  Normally, an archive is searched
     only once in the order that it is specified on the command line.
     If a symbol in that archive is needed to resolve an undefined
     symbol referred to by an object in an archive that appears later on
     the command line, the linker would not be able to resolve that
     reference.  By grouping the archives, they all be searched
     repeatedly until all possible references are resolved.

     Using this option has a significant performance cost.  It is best
     to use it only when there are unavoidable circular references
     between two or more archives.

-- 
Mike Wey