Regarding the GCC issue, if we don't need to use the RPM package to install GCC, what if we use the compilation method to install GCC?

Regarding the GCC issue, if we don't need to use the RPM package to install GCC, what if we use the compilation method to install GCC? -- Linux general technology-Linux programming and kernel information. The following is a detailed description. We know that GCC is a compilation tool, and GCC is written in C (I am not sure ), who will compile GCC after it is written in C ?????????
Because it is compiled, without it, who will compile it?
After learning C for a while, this problem is always bothering me.

Thank you for your answers.