MISRA C++:2008 Rule 18-0-5

The unbounded functions of library <cstring> shall not be used

Description

The unbounded functions of library <cstring> shall not be used.¹

Rationale

The unbounded functions of library <cstring> does not check the bounds of a buffer when reading from it or writing into it. This results in accessing a buffer beyond its end, which is undefined behavior. Functions that reads a buffer beyond its end include: strcpy, strcmp, strcat, strchr, strspn, strcspn, strpbrk, strrchr, strstr, strtok and strlen.

Polyspace Implementation

Polyspace^® reports a violation if you use any of these names in your code:

• strcpy

• strcmp

• strcat

• strchr

• strspn

• strcspn

• strpbrk

• strrchr

• strstr

• strtok

• strlen

Troubleshooting

If you expect a rule violation but Polyspace does not report it, see Diagnose Why Coding Standard Violations Do Not Appear as Expected.

Examples

Use of Unbounded <cstring> Function

In this example, Polyspace reports a violation on the use of the unbounded strcpy() function.

#include <cstring>

void foo ( const char * ptr2char )
{
   char str [ 10 ];
   strcpy ( str, ptr2char );   // Non-compliant   
}

Check Information

Group: Language Support Library

Category: Required

Version History

Introduced in R2013b