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IAR Embedded Workbench for RX 5.20

CERT-DCL30-C_a

In this section:
Synopsis

Declare objects with appropriate storage durations.

Enabled by default

Yes

Severity/Certainty

High/Medium

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Full description

Every object has a storage duration that determines its lifetime: static, thread, automatic, or allocated. Do not attempt to access an object outside of its lifetime. Attempting to do so is undefined behavior and can lead to an exploitable vulnerability. This check is identical to MEM-stack, MISRAC++2008-7-5-1_b, MISRAC++2023-6.8.2_b, MISRAC2004-17.6_a, MISRAC2012-Rule-18.6_a.

Coding standards
CERT DCL30-C

Declare objects with appropriate storage durations

MISRA C:2004 17.6

(Required) The address of an object with automatic storage shall not be assigned to another object that may persist after the first object has ceased to exist.

MISRA C:2012 Rule-18.6

(Required) The address of an object with automatic storage shall not be copied to another object that persists after the first object has ceased to exist

MISRA C++ 2008 7-5-1

(Required) A function shall not return a reference or a pointer to an automatic variable (including parameters), defined within the function.

MISRA C++ 2023 6.8.2

(Mandatory) A function must not return a reference or a pointer to a local variable with automatic storage duration

Code examples

The following code example fails the check and will give a warning:

int *example(void) {
  int a[20];
  return a;  //a is a local array
}

The following code example passes the check and will not give a warning about this issue:

#include <stdlib.h>

int* example(void) {
  int *p,i;
  p = (int *)malloc(sizeof(int));
  return p;  //OK - p is dynamically allocated

}