the cstring header is missing so the compilation failes attached ebuild.patch and gcc.patch
Created attachment 146663 [details, diff] gcc 4.3 includes patch
Created attachment 146665 [details, diff] libwpd-0.8.10-r1.ebuild.patch
app-text/libwpd-0.8.14 which I just added compiles fine for me out of the box with gcc-4.3.0. Thanks anyway. Please reopen if it doesn't build for you.