Learning about AST in Clang
In this section, we are going to learn about Clang's AST in-memory representation and its essential API usage. The first part of this section will provide you with a high-level overview of Clang AST's hierarchy; the second part will focus on a more specific topic regarding type representation in Clang AST; and the final part will show you the basic usage of AST matcher, which is extremely useful when you're writing an AST plugin.
In-memory structure of Clang AST
The in-memory representation of AST in Clang is organized in a hierarchy structure that resembles the syntax structure of C-family language programs. Starting from the top-most level, there are two classes worth mentioning:
TranslationUnitDecl: This class represents an input source file, also called a translation unit (most of the time). It contains all the top-level declarations – global variables, classes, and functions, to name a few – as its children...
