http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54037
--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> 2012-07-19 22:04:39 UTC --- (In reply to comment #2) > (In reply to comment #1) > > Created attachment 27836 [details] > > A patch to add -Wpointer-to-signed-int-cast > > This won't work for intptr_t which is a signed integer type. -Wpointer-to-signed-int-cast will issue a warning for [hjl@gnu-6 pr54037]$ cat foo.c #include <stdint.h> unsigned long long foo (void *p) { return (intptr_t) p; } [hjl@gnu-6 pr54037]$ -Wpointer-to-signed-int-cast is used to help catch the potential point to signed integer cast issue. It shouldn't be turned on by default.