Jeff King <peff@xxxxxxxx> writes: > The preprocessor doesn't know that we'll be confused if "s" isn't > resolved, and by the time the compiler sees it, it's a string already. > > Obviously we could add a test that catches this at run-time, but we > should be able to do better (catch it earlier, and with less code). Ah, great minds think alike. I am glad you have already thought it through. > My first thought was: why can't we just treat the port as an "int" in > the first place? The answer is mostly that getaddrinfo() expects it as a > string. It could even be a non-numeric service like "http" in theory > (and looked up in /etc/services; Debian's even has "git" in it!), but > our get_host_and_port() refuses to allow that. But even if we didn't > want to ever support non-numeric service names, it makes the code more > awkward (we have to format the port into an extra buffer). > > This would work: > > diff --git a/connect.c b/connect.c > index fd3179e545..1eba71e34c 100644 > --- a/connect.c > +++ b/connect.c > @@ -753,7 +753,7 @@ static char *host_end(char **hoststart, int removebrackets) > } > > #define STR_(s) # s > -#define STR(s) STR_(s) > +#define STR(s) (STR_(s) + BUILD_ASSERT_OR_ZERO(s)) OOoooh. Clever. A pointer plus N indexes into an array, but if the offset is N then the pointer is left intact so the caller does not see the difference. > ... But the > BUILD_ASSERT doesn't seem too bad to me. Indeed.
