ISO C does not allow empty statements outside of functions, and gcc
will warn the trailing semicolons when compiling with -pedantic:
warning: ISO C does not allow extra ‘;’ outside of a function [-Wpedantic]
But our code cannot compile with -pedantic anyway, at least because
warning: ISO C does not support ‘__PRETTY_FUNCTION__’ predefined identifier [-Wpedantic]
Without -pedatnic, clang and even old gcc (3.4) generate no warnings about
those semicolons, so let's just drop __useless_struct_to_allow_trailing_semicolon__.
xyz_from_string() functions defined with DEFINE_STRING_TABLE_LOOKUP() properly
handle NULL strings already. make sure the equivalent functions defined with
DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN() do the same.
In a couple of cases we maintain configuration settings that know an on
and off state, like a boolean, plus some additional states. We generally
parse them as booleans first, and if that fails check for specific
additional values.
This adds a generalized set of macros for parsing such settings, and
ports one use in resolved and another in networkd over to it.
Zbigniew Jędrzejewski-Szmek
Lennart Poettering
Daniel Mack
Thomas Hindoe Paaboel Andersen