I'm trying to search with IDA pro constants of type "#define SIZE 100" and normal local variables from a gcc-compiled binary file. I know there are a lot of open threads on the subject but I can't quite figure it out. For example, this tutorial is very close to what I want, but I don't understand how I can display them graphically in IDA pro. I'm new at this, thanks.
Generally speaking, this is not possible with any reverse engineering tool. If the programmer created custom
#define statements to associate numbers with symbolic names, this information will be destroyed by the compiler very early into the compilation process, long before the binary is ultimately created. Local variable names are also not preserved in the final binary, unless the binary contains debug information (or you have external debug information that you can apply to the binary). However, if this were the case, IDA would have already applied the information, and you would already see the proper names.
TL;DR compilation destroys all symbolic names, and generally speaking, they cannot be recovered without debug information.