Bug#329836: gcc-4.0: static functions which are called only indirectly are considered "unused"

[Justin Pryzby <justinpryzby@users.sourceforge.net>]

Package: gcc-3.3
Version: 4.0.1-3
Severity: normal
Tags: upstream

I have a static function, the address of which is passed to a curl_*
library function for use as a callback.  The function is otherwise
unused.  Compilation with gcc:

cc -W -Wall -Winline -O6  -g -std=gnu99 -DPATH_SEP=\'/\'   -Wl,-O6 usnoquery.c libastro.a  -lm  -L/usr/lib -lcurl -lidn -lssl -lcrypto -ldl -lssl -lcrypto -ldl -lz -o usnoquery
usnoquery.c:514: warning: 'write_data' defined but not used

I think the warning is erroneous, no?