5.6.1 Portability of Headers

This section tries to collect knowledge about common headers, and the problems they cause. By definition, this list always requires additions. Please help us keeping it as complete as possible.

‘limits.h’

C99 says that ‘limits.h’ defines LLONG_MIN, LLONG_MAX, and ULLONG_MAX, but many almost-C99 environments (e.g., default GCC 4.0.2 + glibc 2.4) do not define them.

‘inttypes.h’ vs. ‘stdint.h’

The C99 standard says that ‘inttypes.h’ includes ‘stdint.h’, so there's no need to include ‘stdint.h’ separately in a standard environment. Some implementations have ‘inttypes.h’ but not ‘stdint.h’ (e.g., Solaris 7), but we don't know of any implementation that has ‘stdint.h’ but not ‘inttypes.h’.

‘linux/irda.h’

It requires ‘linux/types.h’ and ‘sys/socket.h’.

‘linux/random.h’

It requires ‘linux/types.h’.

‘net/if.h’

On Darwin, this file requires that ‘sys/socket.h’ be included beforehand. One should run:

AC_CHECK_HEADERS([sys/socket.h]) AC_CHECK_HEADERS([net/if.h], [], [], [#include <stdio.h> #ifdef STDC_HEADERS # include <stdlib.h> # include <stddef.h> #else # ifdef HAVE_STDLIB_H # include <stdlib.h> # endif #endif #ifdef HAVE_SYS_SOCKET_H # include <sys/socket.h> #endif ])

‘netinet/if_ether.h’

On Darwin, this file requires that ‘stdio.h’ and ‘sys/socket.h’ be included beforehand. One should run:

AC_CHECK_HEADERS([sys/socket.h]) AC_CHECK_HEADERS([netinet/if_ether.h], [], [], [#include <stdio.h> #ifdef STDC_HEADERS # include <stdlib.h> # include <stddef.h> #else # ifdef HAVE_STDLIB_H # include <stdlib.h> # endif #endif #ifdef HAVE_SYS_SOCKET_H # include <sys/socket.h> #endif ])

‘stdint.h’

See above, item ‘inttypes.h’ vs. ‘stdint.h’.

‘stdlib.h’

On many systems (e.g., Darwin), ‘stdio.h’ is a prerequisite.

‘sys/mount.h’

On FreeBSD 4.8 on ia32 and using gcc version 2.95.4, ‘sys/params.h’ is a prerequisite.

‘sys/ptem.h’

On Solaris 8, ‘sys/stream.h’ is a prerequisite.

‘sys/socket.h’

On Darwin, ‘stdlib.h’ is a prerequisite.

‘sys/ucred.h’

On Tru64 5.1, ‘sys/types.h’ is a prerequisite.

‘X11/extensions/scrnsaver.h’

Using XFree86, this header requires ‘X11/Xlib.h’, which is probably so required that you might not even consider looking for it.

AC_CHECK_HEADERS([X11/extensions/scrnsaver.h], [], [], [[#include <X11/Xlib.h> ]])