gcj implements several warnings. As with other generic
gcc warnings, if an option of the form -Wfoo enables a
warning, then -Wno-foo will disable it. Here we've chosen to
document the form of the warning which will have an effect - the
default being the opposite of what is listed.
-Wredundant-modifiers
gcj will warn about redundant modifiers. For
instance, it will warn if an interface method is declared public.
-Wextraneous-semicolon
gcj to warn about empty statements. Empty statements
have been deprecated.
-Wno-out-of-date
gcj not to warn when a source file is
newer than its matching class file. By default gcj will warn
about this.
-Wunused
gcc's -Wunused.
-Wall
-Wredundant-modifiers -Wextraneous-semicolon
-Wunused.