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IAR Embedded Workbench for RX 5.20

CERT-INT33-C_c

In this section:
Synopsis

Ensure that division and remainder operations do not result in divide-by-zero errors.

Enabled by default

Yes

Severity/Certainty

Low/High

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Full description

The result of the / operator is the quotient from the division of the first arithmetic operand by the second arithmetic operand. Division operations are susceptible to divide-by-zero errors. Overflow can also occur during two's complement signed integer division when the dividend is equal to the minimum (most negative) value for the signed integer type and the divisor is equal to -1. This check is identical to ATH-div-0-cmp-bef, MISRAC2004-1.2_f, MISRAC2012-Rule-1.3_d, SEC-DIV-0-compare-before.

Coding standards
CERT INT33-C

Ensure that division and modulo operations do not result in divide-by-zero errors

MISRA C:2004 1.2

(Required) No reliance shall be placed on undefined or unspecified behavior.

MISRA C:2012 Rule-1.3

(Required) There shall be no occurrence of undefined or critical unspecified behaviour

Code examples

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

int foo(int p)
{
  int a = 20, b = 1;
  b = a / p;
  if (p == 0) // Checking the value of 'p' too late.
    return 0;
  return b;
}

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

int foo(int p)
{
  int a = 20, b;
  if (p == 0)
    return 0;
  b = a / p;    /* Here 'p' is non-zero. */
  return b;
}