Phase 4: Linking
Phase 4 is called linking. C++ programs typically contain references to functions and data defined elsewhere, such as in the standard libraries or in the private libraries of groups of programmers working on a particular project (Fig. 1.4). The object code produced by the C++ compiler typically contains “holes” due to these missing parts. A linker links the object code with the code for the missing functions to produce an executable program (with no missing pieces). If the program compiles and links correctly, an executable image is produced.