🚀 go-pugleaf

G'day

I have a situation where two static structures at the external level
are defined and initialized to each have a member pointer to the other.
My problem is finding the proper ANSI declarations/definitions for this
case.

It is obvious that the second object defined should first have a
forward declaration for the first object to be properly initialized.
Maybe a sketch will do here:

	<linkage> struct x i7;
	static struct x i6 = { &i7 };
	<linkage> struct x i7 = { &i6 };

Now, the <linkage> is what I find different compilers have different
expectations of. ANSI 3.7.2 is where I looked for the answer. I tried
gnu (1.39) which I hope is ANSI by now. It likes this one:

(1)	extern int i7;
(2)	static int i7 = 1;

It hates this one:

	static int i7;		/* tentative definition, internal linkage */
(3)	extern int i7 = 1;

Microsoft 5.1 likes both, but I wouldn't trust it much.

Q: what should the comment on the right say for (1,2,3) in the sense on
the examples at the end of 3.7.2? What I want is to first give a
'tentative definition' or a 'declaration' followed later by the
initialized 'definition'.

I know how shady this area is with traditional compilers and do not wish to
discuss it, so please limit replies to ANSI issues.