Question

Back in the 90s when I first started out with MFC I used to dynamically link my apps and shipped the relevant MFC DLLs. This caused me a few issues (DLL hell!) and I switched to statically linking instead – not just for MFC, but for the CRT and ATL. Other than larger EXE files, statically linking has never caused me any problems at all – so are there any downsides that other people have come across? Is there a good reason for revisiting dynamic linking again? My apps are mainly STL/Boost nowadays FWIW.

Answer 1

There are some downsides:

• Bigger exe size (esp if you ship multiple exe’s)
• Problems using other DLL’s which rely on or assume dynamic linking (eg: 3rd party DLL’s which you cannot get as static libraries)
• Different c-runtimes between DLL’s with independent static linkage (no cross-module allocate/deallocate)
• No automatic servicing of shared components (no ability to have 3rd party module supplier update their code to fix issues without recompiling and updating your application)

We do static linking for our Windows apps, primarily because it allows xcopy deployment, which is just not possible with installing or relying on SxS DLL’s in a way which works, since the process and mechanism is not well documented or easily remotable. If you use local DLL’s in the install directory it will kinda work, but it’s not well supported. The inability to easily do remote installation without going through a MSI on the remote system is the primary reason why we don’t use dynamic linking, but (as you pointed out) there are many other benefits to static linking. There are pros and cons to each; hopefully this helps enumerate them.