MISRA-C:2004  Rule  9.1:  (Required)			All automatic variables shall have been assigned a value before being used.

Note that according to the ISO C standard, variables with static storage duration are automatically initialised to zero by default, unless explicitly initialised. In practice, many embedded environments do not implement this behaviour. Static storage duration is a property of all variables declared with the static storage class specifier, or with external linkage. Variables with automatic storage duration are not usually automatically initialised.

Example Code:

/* PRQA S 2983,3447 ++ */
#include "misra.h"
#include "m2cmex.h"


extern S16 test_0901a( const S16 *p );


extern S16 test_0901( void )
{
   S16 a;
   S16 b;
   S16 c;
   S16 d;
   S16 e;
   S16 r;

   r = a;                          /* MISRA Violation */

   if ( s16a > 0 )
   {
       b = s16a;
       e = s16a;
   }

   r = r + b;                      /* MISRA Violation */

   c = test_0901a( &d );           /* MISRA Violation */

   d = 1;

   c += test_0901a( &e );          /* MISRA Violation */

   return r + c + d;
}

QAC messages that encompass this guideline:

2883	This 'goto' statement will always bypass the initialization of local variables.
2961	Definite: Using value of uninitialized automatic object '%s'.
2962	Apparent: Using value of uninitialized automatic object '%s'.
2971	Definite: Passing address of uninitialized object '%s' to a function parameter declared as a pointer to const.
2972	Apparent: Passing address of uninitialized object '%s' to a function parameter declared as a pointer to const.

(c) The Motor Industry Research Association, 2004

QA C Source Code Analyser 8.1.2 MISRA-C:2004 Compliance Module 3.2 © 2013 Programming Research www.programmingresearch.com

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