AC_CHECK_HEADERS([unistd.h])

[Peter]

what is that macro doing?

It is checking if that header is available, and defines a PP macro in config.h. BUT we are not using config.h in any file, and shouldn't we at least define a ACTION-IF-NOT-FOUND. Or why are we doing this check?

[Peter]

This actually includes all these macros (except AC_PROG_LIBTOOL)

# Checks for header files.
AC_CHECK_HEADERS([unistd.h])

# Checks for typedefs, structures, and compiler characteristics.
AC_HEADER_STDBOOL
AC_C_CONST
AC_C_INLINE
AC_TYPE_SIZE_T

# Checks for library functions.
AC_PROG_LIBTOOL
AC_FUNC_ERROR_AT_LINE
AC_HEADER_STDC
AC_CHECK_FUNCS([pow sqrt])

Can I just remove them, or should we make configure complain if something is missing? I think it is stupid to have macros that just add info tho config.h which is never used. According to svn praise the macros were added in r71 and as far as I can see there was no reason but inexperience.

[Peter]

(In [1459]) Cleaning up in configure.ac. Removed a couple of macros that were C specific or obsolete. Possibly we could keep tests for sqrt but then we need to use the test somehow (see discussion in ticket:430. Closes #430 and #431.