codeql/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/IntMultToLong.c

long long f(short x, int y, long long z) {
    y == x * x;         // safe
    y == x * (int)x;    // safe
    z == y * x;         // unsafe
    z == (long long)(y * x); // we assume the user knows what they are doing
    if(x == 56)
        return y * y;   // unsafe
    if(x == 56)
        return (long long)(y * y); // we assume the user knows what they are doing
    return 42 * 23;     // safe
}

void int_float(int i, int j, long long ll, float f, float g, double h, char c) {
    // note: where cases are marked as 'dubious' that means there could be an overflow,
    //       but the target type does not imply that the developer anticipates one as with
    //       an int -> long long conversion.  We should therefore not flag these cases.

    double v1_1 = f * g; // unsafe (float -> double)
    double v1_2 = f * (double)g; // safe

    double v2_1 = (i + j) * f; // unsafe (float -> double)
    double v2_2 = (i + j) * (double)f; // safe

    double v3_1 = i * j; // dubious (int -> double)
    double v3_2 = (double)i * j; // safe
    double v3_3 = (long long)i * j; // safe

    float v4_1 = i * j; // dubious (int -> float)
    float v4_2 = i * (float)j; // safe

    long long v5_1 = f * g; // safe (float -> long long)
    long long v5_2 = f * (long long)g; // safe
    long long v5_3 = (long long)f * (long long)g; // safe

    int v6_1 = f * g; // safe (float -> int)
    int v6_2 = (int)f * g; // safe

    double v7_1 = f * f; // unsafe (float -> double)
    double v7_2 = h * h; // safe
    double v7_3 = (f * f); // unsafe (float -> double) [NOT DETECTED]

    float v8_1 = f * f * 2.0; // dubious (float -> double -> float)
		// ^ though 2.0 is strictly speaking a double, it's unlikely the author anticipates requiring a double here
    float v8_2 = f * f * 2.0f; // safe (float -> float)

    float v9_1 = f * 2.0 * f; // dubious (float -> double -> float)
    float v9_2 = f * 2.0f * f; // safe (float -> float)

    float v10_1 = 2.0 * f * f; // dubious (float -> double -> float)
    float v10_2 = 2.0f * f * f; // safe (float -> float)

    float v11_1 = (2.0 * 2.0) * f; // safe (one argument is const)
    float v11_2 = (2.0f * 2.0f) * f; // safe

    float v12_1 = 1.0 + f * f + f * f; // dubious (float -> double -> float)
    float v12_2 = 1.0f + f * f + f * f; // safe
   
    double v13_1 = f * f * 2.0; // unsafe (float -> double) [NOT DETECTED]
    double v13_2 = f * f * 2.0f; // unsafe (float -> double)

    long long v14_1 = i * (i + 2) + ll; // unsafe (int -> long long)
    long long v14_2 = i * (i + 2ll) * ll; // safe
    long long v14_3 = i * (i + (int)2ll) + ll; // unsafe (int -> long long)
}

typedef unsigned long long size_t;
void *malloc(size_t size);

void use_size_t(int W, int H)
{
	int x = 10;
	int y = 20;
	const int vs[] = {10, 20};

	malloc(W * H); // unsafe (int -> size_t)
	malloc((size_t)W * (size_t)H); // safe

	malloc(10 * 20); // safe (small values)
	malloc(x * y); // safe (small values)
	malloc(vs[0] * vs[1]); // safe (small values)
}

int printf(const char *format, ...);

void use_printf(float f, double d)
{
	printf("%f", f * f); // safe (float -> double)
		// ^ there's a float -> double varargs promotion here, but it's unlikely that the author anticipates requiring a double
	printf("%f", d * d); // safe
}

size_t three_chars(unsigned char a, unsigned char b, unsigned char c) {
    return a * b * c; // at most 16581375
}

void g(unsigned char uchar1, unsigned char uchar2, unsigned char uchar3, int i) {
    unsigned long ulong1, ulong2, ulong3, ulong4, ulong5;
    ulong1 = (uchar1 + 1) * (uchar2 + 1); // GOOD
    ulong2 = (i + 1) * (uchar2 + 1); // BAD
    ulong3 = (uchar1 + 1) * (uchar2 + 1) * (uchar3 + 1); // GOOD

    ulong4 = (uchar1 + (uchar1 + 1)) * (uchar2 + 1); // GOOD
    ulong5 = (i + (uchar1 + 1)) * (uchar2 + 1); // BAD

    ulong5 = (uchar1 + 1073741824) * uchar2; // BAD [NOT DETECTED]
    ulong5 = (uchar1 + (1 << 30)) * uchar2; // BAD [NOT DETECTED]
    ulong5 = uchar1 * uchar1 * uchar1 * uchar2 * uchar2 * uchar2; // BAD [NOT DETECTED]
    ulong5 = (uchar1 + (unsigned short)(-1)) * (uchar2 + (unsigned short)(-1)); // BAD
}

struct A {
    short s;
    int i;
};

void g2(struct A* a, short n) {
    unsigned long ulong1, ulong2;
    ulong1 = (a->s - 1) * ((*a).s + 1); // GOOD
    ulong2 = a->i * (*a).i; // BAD
}

int global_i;
unsigned char global_uchar;
void g3() {
    unsigned long ulong1, ulong2;
    ulong1 = global_i * global_i; // BAD
    ulong2 = (global_uchar + 1) * 2; // GOOD
}