Why would we need intermodular analysis? How does the analyzer benefit from it? Normally, our tool is checking only one source file at a time. The analyzer doesn't know about the contents of other project files. Intermodular analysis allows us to provide the analyzer with information about the entire project structure. This way, the analysis becomes more accurate and qualitative. This approach is similar to Link Time Optimization (LTO). For example, the analyzer can learn about a function behavior from another project file and issue a warning. It may be, for instance, dereference of a null pointer that was passed as an argument to an external function.
Implementation of intermodular analysis is a challenging task. Why? To find out the answer to this question, let's first dig into the structure of C++ projects.