Explicit Cast Insertion

Explicit cast insertion is a transformation that introduces explicit type casts in situations where implicit type conversions would otherwise occur. By making type conversions explicit, this technique improves code clarity, prevents unintended behavior, and enhances static code analysis. It is particularly useful in strongly typed languages, ensuring that conversions are intentional and reducing ambiguity in expressions involving mixed data types. While preserving program semantics, explicit cast insertion helps avoid compiler warnings and improves maintainability by making type changes more transparent.

Explicit Cast Insertion Transformation in emmtrix Studio

emmtrix Studio can implement explicit cast insertion using #pragma directives or via the GUI. Cast insertion is a transformation that inserts explicit type casts in situations where implicit type conversion will take place. The transformation preserves the code-semantics.

Typical Usage and Benefits

The transformation is used to generate clearer code and to increase capabilities of the code analysis.

Example

/* The following code tests cast insertion transformation applied to main function.
 * In the given example, in expressions sum(a, b), if (a) and x ? a : b, there is implicit type conversion. 
 * Explicit type casts are inserted in the relevant places.
 */   

int sum(int num1, int num2) {
    return num1 + num2;
}
#pragma EMX_TRANSFORMATION ExplicitCastInserter
int main(void) {
    char a = 5;
    char x = 's';
    float b = 3.14159;
    int c;
    sum(a, b);
    if (a) {
        printf(” % c\ n”, a);
    }
    c = x ? a : b;
    return 0;
}

/* The following code is the generated code after the transformation has been applied.
 */

int sum(int num1, int num2) {
    return num1 + num2;
}
int main() {
    char a = (char) 5;
    char x = (char)
    's';
    float b = (float) 3.14159;
    int c;
    sum((int) a, (int) b);
    if ((_Bool) a) {
        printf(” % c\ n”, a);
    }
    c = (int)((_Bool) x ? (float) a : b);
    return 0;
}

Explicit Cast Insertion