I too am running on a PPC Mac with OS-X 10.4.11, using the gnu tools that came installed.
Chris’ advice to not use some other gnu tools than what came with the machine is probably the
best, but I will add:
I have successfully built llvm and clang from the 2.9 tar balls with only two very minor source code edits.
(I’ll be glad to post them, but they were so trivial that if you run into the same ones you will no doubt
figure them out on your own.)
BUT… I gave up using “configure” long long ago, and am only using “cmake” exclusively.
I strongly recommend getting away from “configure” and start using “cmake” asap, the sooner