I am always curious how different C programs decide how to manage memory. In this case there are is a custom string library. Functions returned owned heap-allocated strings. However, I think there's a problem where static strings are used interchangably with heap-allocated strings, such as in the function `string class_simple_name(string full)` ( https://github.com/neocanable/garlic/blob/72357ddbcffdb75641... ) Somet…
At a basic level, you can create memory on the stack or on the heap. Obviously I will focus on the heap as that is dynamically allocating memory of a certain size.
The C programming language does not force you how to handle memory. You are pretty much on your own. For some C programmers (and likely more inexperienced ones) they will malloc individual variables like they are creating a 'new' instance in a typical OOP language like Java. This can be a telltale sign of a programmer working with C that comes from an OOP background. As they learn and improve on their C skills they realise they should create a chunk of memory of a certain type, but could still be malloc(ing) and free(ing) all over the code, making it difficult to understand what is being used and where -- especially if you are looking at code you did not write.
You can also have programs that do not bother free(ing) memory. For example, a simple shell program that just does simple input->process->output and terminates. For these types of programs, just let the OS deal with freeing the memory.
Good C code (in my opinion) uses malloc and free in only a handful of functions. There are higher level functions for proper Allocators. One example is an Arena Allocator. Then if you want a function which may require dynamic memory, you can tell it which allocator to use. It gives you control, generally speaking. You can create a simple string library or builder with an allocator.
Of course an Allocator does not have to use memory on the heap. It can still use on the stack as well.
There are various other patterns to use in the world of memory, especially in C.