GCC cross compiler make vs make all-gcc, why does one give me an error but the other compiles fine?

I built an i386-elf cross compiler by following this guide in the osdev wiki, however, before I found that guide, i was attempting to compile (and failing) by simply running make after configuring GCC. I kept getting this error 10 or so minutes into the compilation:

checking for the value of EOF... configure: error: computing EOF failed

However, when I did make all-gcc followed by make all-target-libgcc, both gcc and libgcc compiled with no errors. Same thing for make install, it only worked when i did make install-target-libgcc and make install-gcc.

Why do I have to compile them separately? And what does the EOF failed error mean?