Read the Dragon Book compilation Principle Semantic Analysis (1) ...

An abstract syntax tree is generated, followed by semantic analysis ... The tasks of semantic analysis are as follows:

A relatively simple type checking algorithm can be this:

This can be followed by an ID:

This leads to the concept of the symbol table:

At the same time the symbol table should also meet the concept of scope in the program, the implementation of the scope of the method is as follows:

At the same time the symbol table should also solve the problem of namespaces, you can see that the list appears more than once, but the actual compiler should still be able to work properly:

The implementation scenario can be as follows:

Read the Dragon Book compilation Principle Semantic Analysis (1) ...