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IAR Embedded Workbench for RX 5.20

MISRAC2012-Rule-9.1_b

In this section:
Synopsis

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

Enabled by default

Yes

Severity/Certainty

High/Medium

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Full description

Read accesses from local buffers were found that are not preceded by writes. This check is identical to MISRAC2004-1.2_a, SPC-uninit-arr-all, CERT-EXP33-C_d.

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:

void example() {
  int a[20];
  int b = a[1];
}

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

extern void f(int*);
void example() {
  int a[20];
  f(a);
  int b = a[1];
}