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IAR Embedded Workbench for Arm 9.70.x

CERT-INT32-C_b

In this section:
Synopsis

Ensure that operations on signed integers do not result in overflow.

Enabled by default

No

Severity/Certainty

High/High

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Full description

Integer operations will overflow if the resulting value cannot be represented by the underlying representation of the integer. Signed integer overflow is undefined behavior. It is important to ensure that operations on signed integers do not result in overflow. This check warns on other wrapping cases except the ones already covered by CERT-INT32-C_a.

Coding standards
CERT INT32-C

Ensure that operations on signed integers do not result in overflow

CWE 190

Integer Overflow or Wraparound

CWE 191

Integer Underflow (Wrap or Wraparound)

CWE 680

Integer Overflow to Buffer Overflow

Code examples

The following code example fails the check and will give a warning:

void func(signed int si_a, signed int si_b) {
    signed int sum = si_a + si_b;
    /* ... */
}

The following code example passes the check and will not give a warning about this issue:

#include <limits.h>

void f(signed int si_a, signed int si_b) {
    signed int sum;
    if (((si_b > 0) && (si_a > (INT_MAX - si_b))) ||
        ((si_b < 0) && (si_a < (INT_MIN - si_b)))) {
        /* Handle error */
    } else {
        sum = si_a + si_b;
    }
    /* ... */
}