Hi! [ This message is about a general issue in GNU/Hurd, which i encountered during i tried to fix Ruby, thus I think it's most relevant for this list. ]
I tried to find out more about the problem with the E* constants in Ruby. I found out that Ruby does the following: It allocates an array of sys_nerr elements (the sys_nerr in glibc on GNU/Hurd is 119) and tries to store an object for each E* constant in one of those elements, but uses the actual value of the constant as offset. However, it doesn't crash while doing this on GNU/Hurd, because it checks if the number is smaller or equal to sys_nerr and if it is not, it simply does not copy it into the array. I am not shure if this actually is the problem (I get a very strange result when using Bignums instead of Fixnums for storing the errno constants; it seems to call a method of an object which has no class at all, which should be impossible in Ruby), but even if this does not cause _any_ harm in the case of Ruby, this shows some general problem: Programs might (and in fact do) assume that sys_nerr is the biggest numeric value of any errno constant, which is not the case on GNU/Hurd. This might cause strange bugs. We would recognise such a problem when working with the program, but not during compilation. For me, this looks similar to the problem with PATH_MAX, which we don't define as UINT_MAX (which should be the current theoretical limit), but not define at all. We could stop defining sys_nerr in glibc (programs that use it should be fixed anyway, shouldn't they?), and indeed <http://www.delorie.com/djgpp/doc/libc/libc_748.html> claims that it's neither POSIX nor ANSI, but Manuel Menal wrote (on #hurd): "sys_nerr is SVID2, SVID3, XPG2 according to a manpage from HP-UX r10.20. It also states: ssys_nerr is the largest message number provided for in the table; it should be checked because new error codes might be added to the system before they are added to the table." I guess that "the table" is reffering to sys_errlist[]. Since we do not have this, it would be interesting to see if one of these standards defines what the meaning of sys_nerr should be if there is no such table. Ok, so what should we done? Cheers, GNU/Wolfgang -- Wolfgang Jährling <[EMAIL PROTECTED]> `-:._ "Omnis enim res, quae dando Debian GNU/Linux user && Debian GNU/Hurd user `-:. non deficit, dum habetur Hurd Hacking Guide - http://stdio.cjb.net/hhg.html ) et non datur, nondum www.debian.org || www.gnu.org || hurd.gnu.org _,-:' habetur, quomodo habenda ["Accelerate your PC - with 9.81 m/s^2."] ,-:' est." --> fsfeurope.org <-- _______________________________________________ Bug-hurd mailing list [EMAIL PROTECTED] http://mail.gnu.org/mailman/listinfo/bug-hurd
