Question

I have an argument with another developer, I’d like to settle here over Dynamic Link vs. Static Link.

In Theory:

Say you have a library with 100 functions, each has significant amounts of code inside it:

int A()
int B()
int C()
..
..and so on...

And your application only calls or depends on one of them.

You have two methods at your disposal.

1. Build the library as a dynamic linked library
2. Build the library as a statically linked library

My colleague claims that linking the static library to our application, the compiler/linker will not add the code of the 99 unused functions into our executable. I claim it will. I claim in this scenario the only advantage is having a single executable and not having to distribute the library with our application, but it will not have significant size differences if we used a dynamically linked library approach.

Who is correct?

Answer 1

It depends 🙂

If you put each function in its own source file, or use the /Gy compile option, each function will be packaged in a separate section of the static library.

The linker will then be able to pick them up as needed, and only include the functions that are actually called.