QA·C Help - 2022

	2022	A tentative definition is being used. Is it appropriate to include an explicit initializer ?

Declarations and Definitions

This is a tentative definition and according to the ISO:C Standard, the object will automatically be initialized to zero.

In practice, some compilers do not conform to the C standard and objects defined with a tentative definition are not necessarily initialized. It may therefore be appropriate to ensure that all objects with linkage are defined with explicit initialization.

For example:


/*PRQA S 1306,3120,3207,3210,3211,3408,3447 ++*/

extern int ea;                /*              Declaration                                                              */
int eb = 5;                   /*              Explicit  definition                                                     */
int ec;                       /* Message 2022 Tentative definition -> definition with implicit initialization to zero  */
int ed;                       /* Message 2021 Tentative definition -> declaration                                      */
int ed;                       /* Message 2021 Tentative definition -> declaration                                      */
int ed = 5;                   /*              Explicit  definition                                                     */
int ee;                       /* Message 2021 Tentative definition -> declaration                                      */
extern int ee = 5;            /*              Explicit  definition                                                     */

static int sa;                /* Message 2022 Tentative definition -> definition with implicit initialization to zero  */
static int sb = 5;            /*              Explicit  definition                                                     */
static int sc;                /* Message 2022 Tentative definition -> definition with implicit initialization to zero  */
static int sd;                /* Message 2021 Tentative definition -> declaration                                      */
static int sd;                /* Message 2021 Tentative definition -> declaration                                      */
static int sd = 5;            /*              Explicit  definition                                                     */
static int se;                /* Message 2021 Tentative definition -> declaration                                      */
static int se = 5;            /*              Explicit  definition                                                     */