Useful GCC warning options
“Useful GCC warning options not enabled by -Wall -Wextra
GCC can warn about questionable constructs in the source code, but most such warnings are not enabled by default – developers need to use the options -Wall and -Wextra to get all generally useful warnings. There are many additional warning options that are not enabled by -Wall -Wextra as they may produce too many false positive warnings or be targeted to a specific obscure use case, but I think a few of them (listed below) may be useful for general use. ”
Warning levels are lowered nightly, to reduce the risk that you unknowingly introduce a warning just because someone else removed one.