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

[Antonio Diaz Diaz]

Martin Koeppe wrote:
> 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.

Of course you are free to port ddrescue to windows.


> Why? As I could see, one block is filled by one readblock(),

A small block, split from a larger block, is filled by a call to 
readblock. The result is then joined to the coreresponding larger block. 
Both larger blocks can have sizes larger than 32 bits. This is why the 
ddrescue logfile is so efficient.


> However, I saw a use of -1 in the size_ field.

-1 means undefined size. It was used for devices of unknown size.


> Where exactly does it break? I can make a new version, if you like.

For example where it moves "#define _FILE_OFFSET_BITS 64" to "os.h" and 
then includes "os.h" after cstdio. This makes ddrescue unable to read 
files larger than 2 GiB on 32 bit systems.

But please, don't send a new version. I do not accept patches with 
windows-specific code.


> I think that in all loops such as
> for (i=0; i<vector<>::size(); i++)
> i should be of the same type as size() returns. That's not int and not unsigned 
> int either, but size_t.

If the size never exceeds what an unsigned int can contain, why should I 
use size_t?


> Every index access, i.e. anything within [] should be of type size_t, or at 
> least unsigned.

Why? AFAIK, negative indices are generally valid as long as array limits 
are not surpassed, being p[-1] equivalent to *(p-1).


Regards,
Antonio.