Re: asymmetry

[Simon Josefsson]

Bruno Haible <address@hidden> writes:

> Simon Josefsson wrote:
>> Thinking about this, there is some asymmetry between structures and
>> functions in gnulib: to get a function from a header file, you need to
>> pull in a module for that function.  To get a structure from a header
>> file, whether you need it or not, you pull in a module for the header
>> file.  This creates some excess dependencies, as can be seen here (netdb
>> wouldn't have to depend on sys_socket).  If there were a 'hostent'
>> module to get the 'struct hostent' declaration from the netdb.h file,
>> the netdb module wouldn't need to depend on sys/socket.h, and the
>> 'hostent' module could depend on the sys_socket module to get that
>> definition on MinGW.  However, this appears to be established procedures
>> in gnulib though, but it can be useful to be aware of this.
>
> The origin of this asymmetry is probably that:
>
> 1) People look at the code size of their executables and shared libraries,
>    and don't care much about the size of the distributed tarball (thanks to
>    autoconf :-S). Therefore an additional dependency is not much of a problem.
>    Whereas an additional compiled function increases the code size.
>
> 2) It's expected that programmers can detect the list of modules they need
>    by looking at their source code: which are the #include<>s, and which are
>    the function calls ("nm")? When a programmer sees a '#include <netdb.h>'
>    it is immediate for him to infer that he needs the 'netdb' module. But
>    it takes more investigation to detect which _parts_ of <netdb.h> he needs.

Right, and it is likely a good trade-off until we know of valid reasons
to work on changing this.

/Simon