CERT.OOP.CSTD_FUNC_USE
Prefer special member functions and overloaded operators to C Standard Library functions.
Prefer special member functions and overloaded operators to C Standard Library functions. These C functions includes: memset(), memcpy(), memmove(), strcpy(), memcmp(), strcmp(). You should use C++ equivalent functionality to replace them.
Vulnerability and risk
Several C standard library functions perform bytewise operations on objects. For instance, std::memcmp() compares the bytes comprising the object representation of two objects, and std::memcpy() copies the bytes comprising an object representation into a destination buffer. However, for some object types, it results in undefined or abnormal program behavior.
Mitigation and prevention
You should use C++ equivalent functionality to replace them. For example, to use the class constructor or overloaded operators such as operator<(), operator>(), operator==(), or operator!=().
Example
#include <cstring>
#include <iostream>
class C {
int scalingFactor;
int otherData;
public:
C() : scalingFactor(1) {}
void set_other_data(int i);
int f(int i) {
return i / scalingFactor;
}
// ...
};
void f() {
C c;
// ... Code that mutates c ...
// Reinitialize c to its default state
std::memset(&c, 0, sizeof(C)); //uncompliant code
std::cout << c.f(100) << std::endl;
}
