DUB / compiling same source and config to different windows subsystems in 32/64 bit

[Mike Parker]

On Monday, 4 March 2019 at 18:34:09 UTC, Robert M. Münch wrote:
> Hi, when compiling a minimal Windows GUI app (using WinMain()) 
> and compiling it with DUB, the 32-bit x86 version is a 
> character subsystem EXE (writeln works) and for x86_64 it's a 
> GUI subsystem EXE (writeln doesn't work). Since compiling the 
> same source, with the same DUB config file, I would expect the 
> x86 and x86_64 version to be equal.
>
> That's the DUB JSON I use:
>
> {
> 	"targetType" : "executable",
>
>  	"libs-windows-x86_64": ["user32", "gdi32"],
>  	"libs-windows-x86"   : ["gdi32"],
> }
>
> So, how can I get a character subsystem for x86_64 and a GUI 
> subsystem for x86?

I stopped using WinMain with D a long time ago. It's not 
necessary. If you always use `main`, then both linkers will 
provide you with a console subsystem app by default. That's 
particularly useful during development. You can add a 
configuration to your dub.json that turns on the windows 
subsystem for both linkers.

For OPTLINK (x86) you only need to pass to the linker 
`/SUBSYSTEM:windows`.

For the MS linker (x86_mscoff, x86_64) you need to that and you 
need to specify that the entry point is `main`, because it will 
expect `WinMain` when you specify the windows subsystem. You can 
do that with `/ENTRY:mainCRTStartup`

https://docs.microsoft.com/en-us/cpp/build/reference/subsystem-specify-subsystem?view=vs-2017
https://docs.microsoft.com/en-us/cpp/build/reference/entry-entry-point-symbol?view=vs-2017