https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110910
Bug ID: 110910
Summary: weakref should allow incomplete array type
Product: gcc
Version: 13.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: jrtc27 at jrtc27 dot com
Target Milestone: ---
Consider:
extern char foo[];
static char weak_foo[] __attribute__((weakref("foo")));
Normally, being a tentative type with internal linkage, weak_foo would not be
allowed to have an incomplete type, and this is what GCC enforces today
("warning: array 'weak_foo' assumed to have one element" / "error: array size
missing in 'weak_foo'" depending on -pedantic). However, weakref is special,
and makes weak_foo not exist at all, but instead be an alias for foo, which can
legitimately have internal linkage. Therefore I believe this restriction,
namely C99 6.9.2p3, should be relaxed when weakref is used. This does mean the
diagnostic for something like:
static char weak_foo[];
...
static char weak_foo[] __attribute__((weakref("foo")));
needs to be delayed until the whole file has been parsed, but given GCC already
supports:
static char foo[];
...
static char foo[42];
as an extension that doesn't seem to be a problem.
