How is “const” implemented?

Question

How does a compiler, C or C++, (for example, gcc) honors the const declaration?

For example, in the following code, how does the compiler keeps trac

Answer 1

Of course it is up the implementation of each compiler, but in a nutshell, it stores the variable's const and volatile qualifiers (if any) in its variable symbol table along with other information such as the variable's type and whether or not it is a pointer / reference.