function declarator strangeness

Kirk 'UhOh' Johnson tuna at athena.mit.edu
Thu May 31 03:39:22 AEST 1990


the following bits of grammar are culled from appendix A of K&R (1st
ed.):

    function-declarator:                          /* page 204 */
        declarator ( parameter-list_opt )

    declarator:                                   /* page 194 */
        identifier
        ( declarator )
        * declarator
        declarator ( )
        declarator [ constant-expression_opt ]

so a function "foo" returning a pointer to a function returning an int
would be declared as:

    int (*foo())()
    {
      /* body of foo */
    }

imagine that i'd like "foo" to take one argument, arg, an integer.
given the bits of grammar shown above, i would expect use:

    int (*foo())(arg)
        int arg;
    {
      /* body of foo */
    }

unfortunately, both pcc and gcc choke upon such a declaration. but if
i rearrange things as

    int (*foo(arg))()
        int arg;
    {
      /* body of foo */
    }

both compilers generate code which seems to do the right thing,
despite the fact that this declaration of "foo" doesn't seem to match
the grammar shown in my copy of K&R (1st ed.).

anybody have any helpful comments? how should the function-declarator
grammar really read? if the problem is that K&R (1st ed.) is out of
date, is there a better reference that isn't?

although i will try to keep up with comp.lang.c to look for responses
to my questions, i'd appreciate it if responses could also be e-mailed
so i don't inadvertently miss them.

thanks in advance for any help

kirk
--

-------------------------------------------------------------------------------
kirk johnson                                                    `Eat blue dogs
tuna at masala.lcs.mit.edu                                          and dig life.'



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