curl, libcurl, libcomprex, leakbug (was:Re: Packaging cURL for cygwin distribution ???)

Charles Wilson
Fri Oct 12 10:22:00 GMT 2001

Versioning for DLLs is important.  Search the archives for more info; 
these threads should get you started -- but be prepared for a lot of 

>> > > [libtool] should
>> > > probably name [dll's] after the oldest ``interface'' (see the document
>> > > quoted above) that the library fully supports.  That is, if you build
>> > > a dll using libtool's --version 5:4:3, you would get library2.dll
>> 5:4:3 is revision 4 of the implementation of interface 5, which
>> is backwards compatible with the 3 previous interface definitions
>> (i.e. it is safe for applications linked against interfaces 5, 4, 3
>> and 2 to load the 5:4:3 dll at runtime).   Libtool translates the
>> 5:4:3 into a system specific version number for the soname to help the
>> runtime loadee choose the best available library at runtime.  As I
>> said before, currently this mapping is wrong on Windows, 
> ======== Robert's hacked libtool seems to use the "correct" mapping,
> below, on windows.
>> and I think
>> the correct mapping is to always use the oldest supported interface
>> number -- in this case library2.dll -- when generating the soname.
>> This is explained fully in the version node of the libtool manual link
>> that was quoted earlier in the thread. 

The upshot of all this is that libraries should follow this naming scheme:

static lib:  /usr/lib/libfoo.a
import lib:  /usr/lib/libfoo.dll.a
dynamic lib: /usr/bin/cygfoo<VER>.dll or /usr/bin/cygfoo-<VER>.dll


> I noticed your example had a DLL name of cygcurl-2.dll. The DLLs (and
> libs) from the mingw version are named:
>    137134  09-25-01 03:21   libcurl.a
>       771  09-25-01 03:01   libcurl.def
>    140524  09-25-01 03:25   libcurl.dll
>     19726  09-25-01 03:25   libcurldll.a
> Is there any specific reason to use cygcurl-2.dll instead of
> libcurl.dll? If so, could you either explain the reason to me or point
> me to a previous discussion of this issue (or both)?

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