[CMake] cmake on Windows x64

[Gregory Peele ARA/VHD]

> -----Original Message-----
> From: Clinton Stimpson [mailto:clinton at elemtech.com]
> Sent: Monday, October 15, 2012 1:41 PM
> To: cmake at cmake.org
> Cc: John Drescher; Gregory Peele ARA/VHD
> Subject: Re: [CMake] cmake on Windows x64
> 
> On Monday, October 15, 2012 01:37:42 PM John Drescher wrote:
> > > Having CMAKE_SYSTEM_PROCESSOR be "x86" for a 64-bit build is very
> > > inconvenient when detecting machine-dependent compiler flags,
> > > constructing directory names for outputs based on configuration,
> > > configuring third party search directories, etc.  It's always
> > > possible to work around (among other things, one can consult the
> > > generator string for Visual Studio builds, though not for MinGW
> > > builds) but that doesn't mean it shouldn't be better behaved - it's
> > > entirely reasonable to assume that CMAKE_SYSTEM_PROCESSOR should be
> > > the target processor for the build, especially so that you can have
> > > similar behavior on Windows, Linux, and Mac.  Though as previously
> > > discussed I also have the opposite problem on Linux when compiling
> for 32-bit CPU on 64-bit OS.
> > I see. I have always compared the size of the pointer for this..
> >
> > John
> 
> Same here,  I use CMAKE_CXX_SIZEOF_DATA_PTR if I need to know that info
> in a CMakeLists.txt file.
> 
> Clint

Hm, I didn't think of that since I've never seen or used that CMake variable.  That would solve the issue for X86 vs. AMD64 native compiles, and I'm not worried about cross-compiles.  Thanks for that idea, it will simplify my build logic.

Gregory Peele, Jr.
Staff Software Engineer
Virtual Heroes - Orlando
Applied Research Associates, Inc.
+1 (407) 823-9121 x 840013