Eric Blake wrote: > > Should gl_MANYWARN_ALL_GCC be adding some gcc -f options? For example, > > at least gcc 4.3.4 -Wdisabled-optimization would emit a warning that > > several other -W warnings are useless without -funit-at-a-time also in > > place (see coreutils commit 5e361387d). Also, according to 'info gcc, > > -Wsuggest-attribute=pure only works if -fipa-pure-const is turned on > > (true by default for -O compilation, but apparently the -W option can > > also catch a few cases even without -O if -fipa-pure-const is manually > > turned on).
-funit-at-a-time is an option which changes the code generation. IMO it should not be enabled by a warnings module. For the same reason, -Wdisabled-optimization is useless for our purposes - it is useful for people who want maximum optimization, but the Autoconf default is -O2 (for a good reason: Avoid less reliable optimizations). So, treat -Wdisabled-optimization like -Wno-unsuffixed-float-constants. > I also meant to add that -fdiagnostics-show-option is a must for > determining which warnings are firing, when deciding which warnings to > avoid. Having these -f options added by default instead of making each > client add them would make maintenance easier. This option influences diagnostics, so IMO it makes sense to add it whenever the compiler supports it. Bruno -- In memoriam Rudolf Slánský <http://en.wikipedia.org/wiki/Rudolf_Slánský>
