[forwarded from http://bugs.debian.org/339495]
you can see[1] that cpp supports -O, -O[1-9], -Os options, and these options
are meaningful (defining macros). but this is not documented in man page[2] and
info[3].
[1]
$ cpp -dM /dev/null | grep OPT
$ cpp -dM -O /dev/null | grep OPT
#define __OPTIMIZE__ 1
$ cpp -dM -Os /dev/null | grep OPT
#define __OPTIMIZE__ 1
#define __OPTIMIZE_SIZE__ 1
$ cpp -dM -O2 /dev/null | grep OPT
#define __OPTIMIZE__ 1
[2] /usr/share/man/man1/cpp-4.0.1.gz
[3] /usr/share/info/cpp-4.0.info.gz
--
Summary: option -O undocumented in cpp docs
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: preprocessor
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: debian-gcc at lists dot debian dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24916
