Stripping Data Symbols (Win64)

[Benjamin Thaut via Digitalmars-d]

On Wednesday, 30 December 2015 at 09:43:32 UTC, Rainer Schuetze 
wrote:
>
>
>
> I noticed something similar recently when compiling a C file 
> with /Gy, see 
> https://github.com/D-Programming-Language/druntime/pull/1446#issuecomment-160880021
>
> The compiler puts all functions into COMDATs, but they are all 
> still linked in if only a single symbol is referenced, even if 
> linked with /OPT:REF.
>
> So I suspect this is not an issue with dmd, but the Microsoft 
> linker. I still wonder whether the approach to use "function 
> level linking" works at all for Win64.
>
> > I noticed by looking at some object file dumps that dmd puts
> each
> > function into its own section, but data symbols, like
> initializers, are
> > all merged into the same section. Could this be the root
> issue?
>
> Having all data in a single section misses some possible 
> optimizations, and it might be the reason for the behavior in 
> your case (you can check this with "dumpbin /all objectfile"), 
> but the issue above does not contain any data.

So if I understand this correctly the microsoft linker only 
strips unused comdats, otherwise always the entire object file 
gets pulled in?

For me stripping of individual data symbols not working is 
actually a good thing, if it doesn't work, I can't break it. ;-)