[Tinycc-devel] __GNUC__ and GLIBC header mess

[Marc Andre Tanner]

There is a problem with the glibc headers. If you run

 cat > glibc-bug.c << EOF
 #include <glob.h>
 EOF

 tcc -c -D_FILE_OFFSET_BITS=64 glibc-bug.c

you get an error because of incompatible types for redefinition of 'glob64'.

glob.h includes sys/cdefs.h which inlcudes features.h and there 
__USE_FILE_OFFSET64 is set to 1.

features.h:

 #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
 # define __USE_FILE_OFFSET64    1
 #endif

The error happens within glob.h. Since __GNUC__ is not defined glob is 
defined as glob64.

 #if __USE_FILE_OFFSET64 && __GNUC__ < 2
 # define glob glob64
 # define globfree globfree64
 #endif

Then later in glob.h we find

 #if !defined __USE_FILE_OFFSET64 || __GNUC__ < 2
   extern int glob (... with glob_t ...)
 #endif

again the check is true because __GNUC__ is not defined.
but because of the earlier #define glob is replaced by glob64.

Further down in glob.h there is

 #ifdef __USE_LARGEFILE64
   extern int glob64 (... with glob64_t ...)
 #endif

so in the end we have 2 different definitions of glob64 which tcc 
rightfully complains.

Are the glibc headers actually supposed to work with other compilers 
than gcc?

The proper fix would probably be to check every time whether __GNUC__ is 
defined at all.

Any suggestion is welcome.

Marc

--
 Marc Andre Tanner >< http://www.brain-dump.org/ >< GPG key: CF7D56C0