Bruce Momjian wrote: > Tom Lane wrote: > > Bruce Momjian <pgman@candle.pha.pa.us> writes: > > >> I'm not sure that macros can have variable number of arguments on all > > >> supported platforms. I've been burnt by this before. > > > > > The actual patch is: > > > > > + #ifdef __GNUC__ > > > + #define vsnprintf(...) pg_vsnprintf(__VA_ARGS__) > > > + #define snprintf(...) pg_snprintf(__VA_ARGS__) > > > + #define printf(...) pg_printf(__VA_ARGS__) > > > + #else > > > + #define vsnprintf pg_vsnprintf > > > + #define snprintf pg_snprintf > > > + #define printf pg_printf > > > + #endif > > > > Uh, why bother with the different approach for gcc? > > Because if we don't do that then the code above fails: > > extern int pg_snprintf(char *str, size_t count, const char *fmt,...) > /* This extension allows gcc to check the format string */ > __attribute__((format(printf, 3, 4))); > > The issue is that the "printf" here is interpreted specially by the > compiler to mean "check arguments as printf". If the preprocessor > changes that, we get a failure. The good news is that only gcc supports > arg checking using __attribute__ and it also supports the __VA_ARGS__ > macros. What I think we do lose is argument checking for non-gcc, but > this seems as close as we can get.
I am adding a comment explaining why those macros are used. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
