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IAR Embedded Workbench for Arm 9.70.x

MISRAC2004-1.2_b

In this section:
Synopsis

(Required) No reliance shall be placed on undefined or unspecified behavior. Using uninitialized values might cause unexpected results or unpredictable behavior, particularly in the case of pointer fields.

Enabled by default

Yes

Severity/Certainty

High/Medium

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Full description

On all execution paths, one or more fields are read from a struct before they are initialized. This check is identical to MISRAC2012-Rule-9.1_d, CERT-EXP33-C_e.

Coding standards
CERT EXP33-C

Do not reference uninitialized memory

CWE 457

Use of Uninitialized Variable

MISRA C:2004 1.2

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

MISRA C:2012 Rule-9.1

(Mandatory) The value of an object with automatic storage duration shall not be read before it has been set

Code examples

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

struct st {
  int x;
  int y;
};

void example(void) {
  int a;
  struct st str;
  a = str.x;
}

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

struct st {
  int x;
  int y;
};

void example(int i) {
  int a;
  struct st str;
  str.x = i;
  a = str.x;
}