Software :: Determining GCC / Binutils And Glibc Version Compatibility

This questions pertains mainly to building a brand new GNU toolchain on one machine for deployment on fs of another machine that has no toolchain installed. I understand the machine on which GNU toolchain is going to be built as the 'build' machine. I understand the machine on which GNU toolchain is going to be deployed as the 'host' machine. I understand the machine on which the code generated by the new GNU toolchain is going to be run as the 'target' machine.

Q1.) Is there a fixed 'rule', 'matrix' or 'table' somewhere which tells me exactly which versions of 'binutils' and 'libc' are required by a particular version of GCC? I.e. something along the lines of:

- gcc ver.'k' can be built using gcc ver.'m'(or later) with binutils ver.'i' and libc ver. 'j'
- gcc ver.'k' will operate with binutils ver.'t' and libc ver.'r'(or later)

Is there some 'rule of thumb' / 'heuristics' giving me the above version requirements for the building and operating GCC, or is this information somehow implied or derived systematically. Where can I find more about the above?

Q2) I assume that the libraries have no dependencies on any underlying software other than the system calls provided by the kernel. Furthermore it appears that the libraries are not too sensitive about the kernel version they run on (I found this out from experience). Therefore I could build the libraries on some build machine and place them on the bare naked newly set up host file system without regard to any other prerequisite SW components?

Q3) During operation, do GCC and its various components place system calls directly to the kernel or via library calls (or both)? In other words I am trying to understand conceptually if GCC requires 'Glibc' for its own operation or not?

Q4) During operation, do the 'binutils' components place system calls directly to the kernel or via library calls (or both)? In other words I am trying to understand conceptually if the 'binutils' require 'Glibc' for their operation or not? ( Of course it is clear to me that when GCC is operating it will need libraries and headers to resolve object references in the target code it produces, but that would be a >different< question).