Compiling GCC 7.2.0 on sparc-sun-solaris2.10

[Luigi30]

Hi,

I'm trying to compile GCC 7.2.0 on a machine running Solaris 10. I
currently have the tgcware GCC 5.5 package installed, binutils 2.29, and
I'm using the GNU linker and assembler.

My compile gets as far as:

Checking multilib configuration for libgcc...
Configuring stage 1 in sparc-sun-solaris2.10/libgcc
[...]
checking for suffix of object files... configure: error: in
`/home/luigi/gcc/gcc-obj/sparc-sun-solaris2.10/libgcc':
configure: error: cannot compute suffix of object files: cannot compile

(I've pasted the rest here: https://pastebin.com/fL8W0gwC)

config.log says xgcc failed to compile a file containing "int main() {
return 0; }". If I try to compile a file with xgcc that just contains a
return 0, I get the following error:

xgcc: error trying to exec 'cc1': execvp: No such file or directory

What am I doing wrong?

Thank you.