LANG.CAST.FN : Dangerous Function Cast

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CodeSonar^® 9.2p0

CONFIDENTIAL

CodeSecure Inc

LANG.CAST.FN : Dangerous Function Cast

Summary

A function pointer is cast to another function pointer that has an incompatible signature or return type.

Properties

MisraC2025

MisraC2025:1.3

There shall be no occurrence of undefined or critical unspecified behaviour

MisraC2025:11.1

Conversions shall not be performed between a pointer to a function and any other type

MisraC2023

MisraC2023:1.3

There shall be no occurrence of undefined or critical unspecified behaviour

MisraC2023:11.1

Conversions shall not be performed between a pointer to a function and any other type

Misra2012

Misra2012:1.3

There shall be no occurrence of undefined or critical unspecified behaviour

Misra2012:11.1

Conversions shall not be performed between a pointer to a function and any other type

Misra2004

Misra2004:11.1

Conversions shall not be performed between a pointer to a function and any type other than an integral type

AUTOSARC++14

AUTOSARC++14:A5-2-2

Traditional C-style casts shall not be used.

AUTOSARC++14:M5-2-6

A cast shall not convert a pointer to a function to any other pointer type, including a pointer to function type.

AUTOSARC++14:M8-4-4

A function identifier shall either be used to call the function or it shall be preceded by &.

MisraC++2008

MisraC++2008:5-2-4

C-style casts (other than void casts) and functional notation casts (other than explicit constructor calls) shall not be used.

MisraC++2008:5-2-6

A cast shall not convert a pointer to a function to any other pointer type, including a pointer to function type.

MisraC++2008:8-4-4

A function identifier shall either be used to call the function or it shall be preceded by &.

MisraC++2023

MisraC++2023:4.1.3

There shall be no occurrence of undefined or critical unspecified behaviour

MisraC++2023:8.2.2

C-style casts and functional notation casts shall not be used

CWE

CWE:704

Incorrect Type Conversion or Cast

JSF++

JSF++:183

Every possible measure should be taken to avoid type casting.

Example

#include <stdio.h>
typedef void (*thunk_t)(void);
typedef int (*int_unary_t)(int);
void A( void ) {}

int B( int i ) { 
    printf("%d", i); 
    return 1; 
}

void lang_cast_fn(void) {
    thunk_t thunk = (thunk_t)A;
    int_unary_t unary = (int_unary_t)B;
        
    thunk = (thunk_t)unary;  /* 'Dangerous Function Cast' warning issued here */
    thunk();
}