I was given a task to port our comparison engine written in native c++ to run in a 64 bit environment. Without modifying anything, I found out that the engine works in 64 bit environment without any problem. But to be compliance, I was still required to get the engine code compiled in the 64 bit compiler. Sounds like an easy task, but it isn't.

The problem is that the engine is compiled using Visual Studio 2003, and VS2003 support for targeting 64 bit environment is pretty much non-existent. Now, I can just convert the solution files to VS2005 or VS 2008 as both of them support multi-platform targeting. I tried that actually and the compiler didn't like the current engine codes, I got lots of compile error. So I reckon by doing that I introduce a whole new set of problems. So that’s not an option.

After some researches, I found a website that suggests that in order to compile VS2003 I have to download "Microsoft Platform SDK". The Platform SDK is an older version of "Microsoft Windows SDK". In there, there's a 64 bit compiler. All you need to do is to change the environment to be 64 bit and then launch VS2003 and specify to use the default environment. Once you've changed the environment, you can't changed it back to target 32 bit without restarting Visual astudio. Thus you need a batch files that will change the environment and launch Visual Studio, which looks like these:

X86 batch file:

X64 batch file:

To confirm you're using the right compiler, you can go to: Tools -> Options -> Projects -> VC++ directories. You will see that the directory now targets the compiler inside the Microsoft Platform SDK folder.

Using the SDK compiler doesn’t work straight away, Im getting the following compile Errors:

This is due to the "/GS" switch being set by default by the platform SDK compiler. The code for the "GS" switch resides in the C Runtime Library, which is the default library that is pulled in by the linker in Visual Studio. However, the version of the runtime library included in Platform SDK is not the same as the one in Visual Studio. Thus in order to fix this issue you must include the "bufferoverflowU.lib" in the Project Linker Command Line, i.e Project Properties -> Linker -> Command Line -> Additional Options.

That’s my journey so far in trying to make VS2003 to target 64 bit environment. Still having some issue with the compiler, when it's been resolved will update this post. Anyway, I highly recommend to visit sites on the references, as most of the stuffs written here are coming from there.

Rwendi

References:
http://www.toymaker.info/Games/html/64_bit.html
http://support.microsoft.com/kb/894573