Follow the instruction for Linux.
On Mac OS X 10.2.x it was reported, that the default gcc (version
3.1 20020420 (prerelease)) fails to compile SDCC. Fortunately there's
also gcc 2.9.x installed, which works fine. This compiler can be selected
by running 'configure' with:
LDFLAGS="-Wl,-syslibroot,/Developer/SDKs/MacOSX10.4u.sdk -arch i386 -arch ppc" \
CXXFLAGS = "-O2 -isysroot /Developer/SDKs/MacOSX10.4u.sdk -arch i386 -arch ppc" \
CFLAGS = "-O2 -isysroot /Developer/SDKs/MacOSX10.4u.sdk -arch i386 -arch ppc"