Getting the basics of linking right
We discussed the life cycle of a C++ program in Chapter 5, Compiling C++ Sources with CMake. It consists of five main stages – writing, compiling, linking, loading, and execution. After correctly compiling all the sources, we need to put them together into an executable. Object files produced in a compilation can't be executed by a processor directly. But why?
To answer this, let's take a look at how a compiler structures an object file in the popular ELF format (used by Unix-like systems and many others):
Figure 6.1 – The structure of an object file
The compiler will prepare an object file for every unit of translation (for every .cpp file). These files will be used to build an in-memory image of our program. Object files contain the following elements:
- An ELF header identifying the target operating system, ELF file type, target instruction set architecture, and information on the position...
