[Qt5-feedback] Qt major versions (was: C++ api to use for UI in addition to QML)

[Konstantin Tokarev]

25.05.2011, 16:39, "Charley Bay" <charleyb123 at gmail.com>:
>> Jason H spaketh:
>> I think if we could lock the lib and exe to specific versions (like Windows SxS)
>> we'd be better off. We just need a way to link to specific versions of the Qt
>> libraries. (Though SxS is still problematic, I think it is an improvement)
> Craig S respondeth:
>> You technically already have what you need with the current releases. The major part of the version is also part of the library name that applications link to (or should link to!). Under Mac and linux, binaries link to llibQtCore.4.dylib and ibQtCore.so.4 respectively. Under Windows, the major version is made part of the library name itself rather than as part of the extension (ie QtCore4.dll) so you have no choice but to link against a specifc major version. Thus, there is already the mechanism required  for an application to link to specific binary compatible levels of Qt.
>>
>> <snip, good overview of major/minor versioning, binary compatibility, and release cycle>
>
> What about out-of-the-box support for static library linking?  While not perfect for every application, large desktop applications like Maya could simply statically-link the required Qt version, and never suffer the "anomalies" of system Qt library upgrade.
>
> I've built-and-statically-linked Qt, but IMHO it would be nice if the static libs were a first-class deployment option (e.g., automatically available when Qt is installed, I'm a commercial customer).
>
> Yes, LGPL applications would still need dynamic linking, so I concede that doesn't address the problem from that standpoint.
>
> Anybody out there shipping with statically-linked Qt?

Static linking is an ugly solution. While it goes when product is one executable file, it significantly bloats size when several binaries are built, and it truly sucks in case of "application + library + lots of plugins", because Qt is linked multiple times.

Dynamic linking itself does not cause any troubles as long as you can ship all needed libraries with your product.


-- 
Regards,
Konstantin