how to compile gcc

[Jiang Long]

Hello,

I 'd like to dig into gcc internals, and would like to compile it with -g. 

I can't find any document on how to do that? I tried 

make BOOT_CFLAGS=-g CFLAGS=-g, 

but it still will add '-O2' later on. 

Any documentation on how GCC is compiled? what are the stages of the
compilation?

Thanks,

-Jiang