https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102821
Bug ID: 102821
Summary: Tentative definition of variable with internal linkage
has incomplete non-array type: missing diagnostics
Product: gcc
Version: 11.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: pavel.morozkin at gmail dot com
Target Milestone: ---
Sample code (t940.c):
static struct s foo;
static struct s {int a;} foo;
Invocation:
$ gcc t940.c -c -std=c11 -pedantic -Wall -Wextra -Wno-unused-variable
Expected diagnostics:
t940.c:1:17: warning: tentative definition of variable with internal linkage
has incomplete non-array type 'struct s'
[-Wtentative-definition-incomplete-type]
Actual diagnostics:
<nothing>
Notes:
1. C11, 6.9.2 External object definitions, 3:
> If the declaration of an identifier for an object is a tentative definition
> and has internal linkage, the declared type shall not be an incomplete type.
2. C11, 4. Conformance, 1:
> In this International Standard, ‘‘shall’’ is to be interpreted as a
> requirement on an implementation or on a program; conversely, ‘‘shall not’’
> is to be interpreted as a prohibition.
