On Mon, Dec 30, 2002 at 11:19:32AM -0500, H. S. Teoh wrote: > On Mon, Dec 30, 2002 at 10:57:47AM -0500, Daniel Jacobowitz wrote: > > On Mon, Dec 30, 2002 at 10:23:16AM -0500, H. S. Teoh wrote: > > > Hi, I just confirmed that trunc() is missing from /usr/include/math.h. > > > Furthermore, the following are also missing (referenced from the manpage > > > of trunc()): > > > - lrint > > > - nearbyint > > > - round > > > > > > Oddly, these functions do *not* appear in the libc info pages. > > > Nevertheless, they are definitely in libm: > > > > How did you confirm that they were not in <math.h>? Judging from your > > previous messages, by using cpp or building a test program. I always > > recommend actually grepping around in /usr/include for them; it can be > > enlightening. > > > > Consider this case: > > #ifdef __USE_ISOC99 > [snip] > > Aha. That explains it. So these functions are only defined for ISO C99?
Yes. Declaring something named "round" when it isn't part of the relevant language standard is a bit much, don't you think? :) > > They are only declared in C99 mode. I believe that is correct. > > Is this indicated in the docs, though? As far as I can tell, the info > pages do not indicate that C99 mode is needed to use these functions. Hmm, I don't see it either. > > > This is on libc6 2.3.1-8. I'm not sure I understand why they are in the > > > .so but not in any header files nor in the info docs. Are there some > > > standard compliance issues here that I'm not aware of? > > > > They're in my copy of the info docs. Try: > > "info libc Arithmetic Arithmetic\ Functions Rounding\ Functions" > > Yeah, I must've been doing something silly when I searched the info pages > (like using 'n' to find the next match, thinking it's vi. :-P) > > Anyway, this bug now looks like a documentation bug/deficiency. The > manpages should add #define _ISO_SOURCE (or whatever the proper name was, > I forgot) for these functions, and the info pages should indicate the C99 > prerequisite as well. Either -D_GNU_SOURCE or -D_ISOC99_SOURCE (or _ISOC9X_SOURCE or __STDC_VERSION__=199901L). -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer
