This looks like a trivial bug in options processing. It's been not working for a long time.
=== [EMAIL PROTECTED]:~/exp-save-temps-dash$ cat hello.c #include <stdio.h> int main() { printf("Hello, world\n"); return 0; } [EMAIL PROTECTED]:~/exp-save-temps-dash$ cat hello.c | /home/mec/gcc-3.4.6/install/bin/gcc -save-temps -x c - cc1: error: unrecognized command line option "-.i" [EMAIL PROTECTED]:~/exp-save-temps-dash$ cat hello.c | /home/mec/gcc-4.0.4/install/bin/gcc -save-temps -x c - cc1: error: unrecognized command line option "-.i" [EMAIL PROTECTED]:~/exp-save-temps-dash$ cat hello.c | /home/mec/gcc-4.1.2/install/bin/gcc -save-temps -x c - cc1: error: unrecognized command line option "-.i" [EMAIL PROTECTED]:~/exp-save-temps-dash$ cat hello.c | /home/mec/gcc-4.2.0/install/bin/gcc -save-temps -x c - cc1: error: unrecognized command line option "-.i" [EMAIL PROTECTED]:~/exp-save-temps-dash$ cat hello.c | /home/mec/gcc-4.3-20070622/install/bin/gcc -save-temps -x c - cc1: error: unrecognized command line option "-.i" [EMAIL PROTECTED]:~/exp-save-temps-dash$ -- Summary: -save-temps when compiling standard input fails Product: gcc Version: 4.3.0 Status: UNCONFIRMED Severity: trivial Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: mec at google dot com GCC build triplet: i686-pc-linux-gnu GCC host triplet: i686-pc-linux-gnu GCC target triplet: i686-pc-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32528