Bug 44257

Summary:	typeof((struct undefined )) fails to compile
Product:	gcc	Reporter:	rusty
Component:	c	Assignee:	Not yet assigned to anyone <unassigned>
Status:	RESOLVED FIXED
Severity:	normal	CC:	gcc-bugs
Priority:	P3
Version:	4.4.3
Target Milestone:	10.0
See Also:	https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88827
Host:		Target:
Build:		Known to work:	10.1.0
Known to fail:	5.1.0, 8.1.0, 9.1.0, 9.4.0	Last reconfirmed:

Description rusty 2010-05-24 00:29:46 UTC

struct foo; 
typeof(struct foo) *p; // This is fine.
typeof(*p) *p2; // foo.c:5: error: dereferencing pointer to incomplete type

This is important, because AFAICT the only way to declare a const pointer for a given type is: "const typeof(*p) *" which doesn't work if p is a pointer to an undefined struct :(

Comment 1 Andrew Pinski 2021-09-20 02:14:38 UTC

Fixed for GCC 10+, most likely by r10-5166 (aka PR 88827).