MISRA C:2012 Rule 21.10

The Standard Library time and date functions shall not be used

Description

Rule Definition

The Standard Library time and date functions shall not be used¹ .

Rationale

Using these functions can cause unspecified, undefined and implementation-defined behavior.

Polyspace Implementation

Polyspace^® reports violations on the use of various time and date functions and related types from the standard library. Flagged functions and types include:

• Types, constants, and functions from the header time.h

• The function wcsftime() from the wchar.h

If the function is a macro and the macro is expanded in the code, this rule is violated. It is assumed that rule 21.2 is not violated.

If you redefine any of the standard library functions as functions or function-like-macros, Polyspace does not report violations on the user-defined functions or fucntion-like-macros.

Troubleshooting

If you expect a rule violation but do not see it, refer to Diagnose Why Coding Standard Violations Do Not Appear as Expected.

Examples

Use of Functions and Types from Header time.h

In this example, the uses of functions and types from the time.h header file are reported as violations of this rule.

#include <stdio.h>
#include <wchar.h>
#include <time.h>              /*Noncompliant*/

typedef time_t my_time_t;                      /*Noncompliant*/

typedef const struct tm my_const_tm_t;         /*Noncompliant*/

void foo(void) {
	clock_t begin = clock();   /*Noncompliant*/

	/* Perform some computation or operation here that you want to measure */

	clock_t end = clock();     /*Noncompliant*/

	double time_spent = (double)(end - begin) / CLOCKS_PER_SEC; /*Noncompliant*/

	printf("Time taken for computation: %f seconds\n", time_spent);

}


void bar() {
	time_t current_time;       /*Noncompliant*/
	time(&current_time);       /*Noncompliant*/
	struct tm *local_time =                   /*Noncompliant*/
	                localtime(&current_time);   /*Noncompliant*/
}

Check Information

Group: Standard Libraries

Category: Required

AGC Category: Required

Version History

Introduced in R2014b

R2025a: More time and date functions from the standard library detected

Polyspace now reports these as violations:

• Use of the standard library function wcsftime().

• Use of types and constants from the header time.h.

R2024a: Including the header time.h reported as violation

Including the header time.h is now reported as a violation fo this rule:

#include<time.h> //Noncompliant