5.9.1 Particular Type Checks

These macros check for particular C types in `sys/types.h', `stdlib.h' and others, if they exist.

Macro: AC_TYPE_GETGROUPS

Define GETGROUPS_T to be whichever of gid_t or int is the base type of the array argument to getgroups.

Macro: AC_TYPE_MBSTATE_T

Define HAVE_MBSTATE_T if <wchar.h> declares the mbstate_t type. Also, define mbstate_t to be a type if <wchar.h> does not declare it.

Macro: AC_TYPE_MODE_T

Equivalent to `AC_CHECK_TYPE(mode_t, int)'.

Macro: AC_TYPE_OFF_T

Equivalent to `AC_CHECK_TYPE(off_t, long)'.

Macro: AC_TYPE_PID_T

Equivalent to `AC_CHECK_TYPE(pid_t, int)'.

Macro: AC_TYPE_SIGNAL

If `signal.h' declares signal as returning a pointer to a function returning void, define RETSIGTYPE to be void; otherwise, define it to be int.

Define signal handlers as returning type RETSIGTYPE:

RETSIGTYPE hup_handler () { ... }

Macro: AC_TYPE_SIZE_T

Equivalent to `AC_CHECK_TYPE(size_t, unsigned)'.

Macro: AC_TYPE_UID_T

If uid_t is not defined, define uid_t to be int and gid_t to be int.