Programming

I have yet to find a memory hungry program thats its caused by its dependencies instead of its data. And frankly the disk space of all libraries is minuscule compared to graphical assets.

You know what's going to really bother the issue? If the program doesn't work because of a dependency. And this happens often across all OSes, searching for these are dime a dozen in forums. "Package managers should just fix all the issues". Until they don't, wrong versions get uploaded, issues compiling them, environment problems, etc etc.

So to me, the idea of efficiency for dynamic linking doesn't really cut it. A bloated program is more efficient that a program that doesn't work.

This is not to say that dynamic linking shouldn't be used. For programs doing any kind of elevation or administration, it's almost always better from a security perspective. But for general user programs? Static all the way.

The user never had much choice to begin with. If I write a program using version 1.2.3 of a library, then my application is going to need version 1.2.3 installed. But how the user gets 1.2.3 depends on their system, and in some cases, they might be entirely unable unless they grab a flatpak or appimage. I suppose it limits the ability to write shims over those libraries if you want to customize something at that level, but that's a niche use-case that many people aren't going to need.

In a static linked application, you can largely just ship your application and it will just work. You don't need to fuss about the user installing all the dependencies at the system level, and your application can be prone to less user problems as a result.

Shared libraries save RAM.

Dynamic linking allows working around problematic libraries, or even adding functionality, if the app developer can't or won't.

Static linking makes sense sometimes, but not all the time.

Personally, I prefer static linking. There's just something appealing about an all-in-one binary.

It's also important to note that applications are rarely 100% one or the other. Full static linking is really only possible in the Linux (and BSD?) worlds thanks to syscall stability - on macOS and Windows, dynamically linking the local libc is the only good way to talk to the kernel.

(There have been some attempts made to avoid this. Most famously, Go attempted to bypass linking libc on macOS in favor of raw syscalls... only to discover that when the kernel devs say "unstable," they mean it.)

disk is cheap and it's easier to test exact versions of dependencies. As a user I'd rather not have all my non OS stuff mixed up.

The main problem is that dynamic linking is hard. It is not just easier for the maintainers of the languages to ignore it, it removes an entire class of problems.

Dynamic linking does not even reliably work with C++, an "old" language with decades of tooling and experience on the matter. You get into all kind of UB when interacting with a separate DSO, especially since there are minimal verification of the ABI compatibility when loading a dynamic library. So you have to wait for a crash to be certain you got it wrong. Unless you control the compilation of your dependencies, it's fairly hard to be certain you won't encounter dynamic linking related issues. At which point you realize that, if the license allows it, you're better off static linking everything, including the C++ library itself: it makes it much more predictable, you're not forcing an additional dependency on your users and most UB are now gone (especially the one about raising exception across DSO boundaries, which can happen behind your back, unless you control the compilation of all your dependencies...).

That's especially true if you are releasing a library where you do not know it's runtime: it might be dynamically loaded via dlopen by a C++ binary that will load its own C++ library first, but some of your users use the version that is stuck on C++14 and your codebase is in C++23. This can be solved, by playing with LD_LIBRARY_PATH, but the application is already making use of it to load the C++ library it comes with instead of the one provided by the system (which only provides C++11 runtime), and it completely ignores the initial state of the environment variable (how could it do otherwise? It would have to guess the path to the libstdc++ is for a newer version and not the older one provided by the system). Now imagine the same issue with your own transitive dependency on top of that: it's a nightmare.

So dynamic linking never really worked, except maybe for C when you expect a single level of dependency, all provided by the system. And even then that's mostly thanks to C simpler ABI and runtime.

So I expect that is the main reason newer languages do not bother with dynamic linking: it introduces way too many issues. Look at your average rust program and how many version of a same dependency it loads, transitively. How would you solve that problem as to be able to load different versions when it matters but try first and foremost to load only one if possible? How would you be able to make the right call? By using semver? If nobody made any mistake why not, but you will rather be required to provide escape hatches that, much like LD_LIBRARY_PATH and LD_PRELOAD, will be misused. And by then, you only "solved" the simplest problem.

Nowadays, based on how applications are delivered on Windows and OSX, and with the advent of docker, flatpack/snap and appimage, I do not see a way back to dynamic linking anytime soon. It's just too complicated of a problem, especially as the number of dependency grows.

Some languages don't even support linking at all. Interpreted languages often dispatch everything by name without any relocations, which is obviously horrible. And some compiled languages only support translating the whole program (or at least, whole binary - looking at you, Rust!) at once. Do note that "static linking" has shades of meaning: it applies to "link multiple objects into a binary", but often that it excluded from the discussion in favor of just "use a .a instead of a .so".

Dynamic linking supports much faster development cycle than static linking (which is faster than whole-binary-at-once), at the cost of slightly slower runtime (but the location of that slowness can be controlled, if you actually care, and can easily be kept out of hot paths). It is of particularly high value for security updates, but we all known most developers don't care about security so I'm talking about annoyance instead. Some realistic numbers here: dynamic linking might be "rebuild in 0.3 seconds" vs static linking "rebuild in 3 seconds" vs no linking "rebuild in 30 seconds".

Dynamic linking is generally more reliable against long-term system changes. For example, it is impossible to run old statically-linked versions of bash 3.2 anymore on a modern distro (something about an incompatible locale format?), whereas the dynamically linked versions work just fine (assuming the libraries are installed, which is a reasonable assumption). Keep in mind that "just run everything in a container" isn't a solution because somebody has to maintain the distro inside the container.

Unfortunately, a lot of programmers lack basic competence and therefore have trouble setting up dynamic linking. If you really need frobbing, there's nothing wrong with RPATH if you're not setuid or similar (and even if you are, absolute root-owned paths are safe - a reasonable restriction since setuid will require more than just extracting a tarball anyway).

Even if you do use static linking, you should NEVER statically link to libc, and probably not to libstdc++ either. There are just too many things that can go wrong when you given up on the notion of "single source of truth". If you actually read the man pages for the tools you're using this is very easy to do, but a lack of such basic abilities is common among proponents of static linking.

Again, keep in mind that "just run everything in a container" isn't a solution because somebody has to maintain the distro inside the container.

The big question these days should not be "static or dynamic linking" but "dynamic linking with or without semantic interposition?" Apple's broken "two level namespaces" is closely related but also prevents symbol migration, and is really aimed at people who forgot to use -fvisibility=hidden.

You might want to have a look at this:

https://drewdevault.com/dynlib

Dynamically linked all the way; you only have to update one thing (mostly) to fix a vulnerability in a dependency, not rebuild every package.

Disk space and RAM availability has increased a lot in the last decade, which has allowed the rise of the lazy programmer, who'll code not caring (or, increasingly, not knowing) about these things. Bloat is king now.

Dynamic linking allows you to save disk space and memory by ensuring all programs are using the only one version of a library laying around, so less testing. You're delegating the version tracking to distro package maintainers.

You can use the dl* family to better control what you use and if the dependency is FLOSS, the world's your oyster.

Static linking can make sense if you're developing portable code for a wide variety of OSs and/or architectures, or if your dependencies are small and/or not that common or whatever.

This, of course, is my take on the matter. YMMV.

It seems the world has shifted towards architectures and tooling that does not allow dynamic linking or makes it harder.

In what context? In Linux, dynamic links have always been a steady thing.

You can statically link half a gig of Qt5 for every single application(half a gig for calendar, half a gig for file mager, etc) or keep it normal size. Also if there will be new bug in openssl, it is not your headache to monitor for vuln announcements.

This compromise makes it easier for the maintainers of the tools / languages

What do you mean? Also how would you implement plug-ins in language that explicitly forbids dynamic loading, assuming such language exists.

Depending on which is more convenient and whether your dependencies are security-critical, you can do both on the same program. :D