Re: [Bug-ddrescue] Re: ddrescue patch for unsigned/signed compiler warnings

[Martin Koeppe]

Hi Christian,

On Tue, 2 Mar 2010, Christian Franke wrote:

> Hi Martin,
> > Hi Antonio,
> >
> > > Martin Koeppe wrote:
> > >   >  Unfortunately gddrescue is not available for Windows.
> > >
> > > There is at least a cygwin port of ddrescue. Just search for "ddrescue
> > > cygwin".
> > yes, but I prefer a native Windows build because I need it on many 
> > different boxes and only occasionally on one particular box. And all of the 
> > boxes don't have cygwin installed.
>
> The Cygwin version of ddrescue does not require a Cygwin install. It requires 
> only cygwin1.dll is in same directory or in the PATH. I have successfully run 
> this ddrescue.exe also from a UBCD4Win Live CD without a Cygwin install.

Thanks for the info. This could be a usable construction. Does it work 
with raw devices? Did you happen to make a performance test?

> I've done a quick build of a native Windows ddrescue.exe with MinGW g++. 
> Required only few hacks (attached).
>
> to build on MSYS:
> $ ./configure
> $ make
>
> to build on Cygwin:
> $ ./configure CXX=g++-3 CPPFLAGS=-mno-cygwin LDFLAGS=-mno-cygwin
> $ make
>
> (Or: cross-compile it on Linux :-)
>
> But this version does not work with raw devices (e.g. '\\.\PhysicalDrive1') 
> because lseek(., 0, SEEK_END) fails. The lseeki64() from MSVCRT.dll 
> apparently cannot be used to determine the size of a raw device.
>
> Did you actually try your code with a raw disk or CD/DVD device? Which MSVC 
> version did you use?

Yes, I have approximately the same hacks for the MSVC build. The 
warnings are just warnings, obviously, and don't make the build 
impossible. And you are right, this version also doesn't work with raw 
devices. I need to replace open() etc. and I didn't yet. I wanted to 
coordinate with Antonio first, to avoid the hacks and make ddrescue 
more portable first. My suggestion was the os.h thing for all platform 
specific code. But there may be other solutions, and Antonio should 
ideally follow one of them.

Even if he doesn't want the platform specific code in the main source, 
reapplying the windows specific things to new versions of ddrescue 
should be easily possible.

Regards,
Martin