diff options
| -rw-r--r-- | Distrib/PortingIssues.mdwn | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/Distrib/PortingIssues.mdwn b/Distrib/PortingIssues.mdwn index 12be7499..58e1b030 100644 --- a/Distrib/PortingIssues.mdwn +++ b/Distrib/PortingIssues.mdwn @@ -20,9 +20,19 @@ You can try out Neal Walfield's implementation of libpthreads. It will serve as The pthread library is available from [the Hurd CVS on Savannah](http://savannah.gnu.org/projects/hurd/). -## <a name="Undefined_PIPE_BUF"> </a> Undefined PIPE\_BUF +## <a name="Undefined_bits_confname_h_macros"> </a> Undefined bits/confname.h macros (PIPE\_BUF, ...) -Change it to use sysconf(\_SC\_PIPE\_BUF) #ifndef PIPE\_BUF. (from a Roland McGrath message in debian-hurd) +If macro XXX is undefined, but macro \_SC\_XXX or \_PC\_XXX is defined in bits/confname.h, you probably need to use sysconf, pathconf or fpathconf to obtain it dynamicaly. + +The following macros have been found in this offending situation (add more if you find them): PIPE\_BUF + +An example with sysconf: (when you find a sysconf offending macro, put a better example) + +#ifndef XXX #define XXX sysconf(\_SC\_XXX) #endif [ offending code using XXX follows ] + +An example with fpathconf: + +#ifdef PIPE\_BUF read(fd, buff, PIPE\_BUF - 1); #else read(fd, buff, fpathconf(fd, \_PC\_PIPE\_BUF) - 1); #endif [ note we can't #define PIPE\_BUF, because it depends on the "fd" variable ] ## <a name="Bad_File_Descriptor"> Bad File Descriptor </a> |