MISRA.VAR.UNIQUE

Identifier clashes with other identifier.

MISRA-C Rule 5.7 (advisory): No identifier name should be reused.

Regardless of scope, no identifier should be re-used across any files in the system. This rule incorporates the provisions of Rules 5.2, 5.3, 5.4, 5.5 and 5.6.

Example

struct air_speed
{
   uint16_t speed; /* knots */
} * x;
struct gnd_speed
{
   uint16_t speed; /* mph                                         */
                   /* Not Compliant - speed is in different units */
} * y;
x->speed = y->speed;

Where an identifier name is used in a header file, and that header file is included in multiple source files, this rule is not violated. The use of a rigorous naming convention can support the implementation of this rule.