QA C Help - Rule-5.2

		MISRA C:2012 Rule-5.2: (Required)			Identifiers declared in the same scope and name space shall be distinct

Amplification:

This rule does not apply if both identifers are external identifers because this case is covered by Rule 5.1.

This rule does not apply if either identifer is a macro identifer because this case is covered by Rule 5.4 and Rule 5.5.

The definition of distinct depends on the implementation and on the version of the C language that is being used:

In C90 the minimum requirement is that the first 31 characters are significant;
In C99 the minimum requirement is that the first 63 characters are significant, with each universal character or extended source character counting as a single character;

Example Code:


#include "misra.h"
#include "m3cmex.h"

            /* 1234567890123456789012345678901 *****/
static int32_t b23456789012345678901234567;
static int32_t b23456789012345678901234567890;                  /*      */      /* Compliant */

            /* 1234567890123456789012345678901 ******/
static int32_t a234567890123456789012345678901234;
static int32_t a234567890123456789012345678901234x;             /* 0779 */      /* Non-compliant */

extern int16_t rule_0502(void)
{
       /* 1234567890123456789012345678901 ******/
  int32_t a234567890123456789012345678901234y;                  /* 0779 */      /* Not-compliant with Rule 5.3 */

  return 1;
}

QAC messages that encompass this guideline:

0779 [U] Identifier does not differ from other identifier(s) (e.g. '%s') within the specified number of significant characters.

Related rules:

Rule-1.3 There shall be no occurrence of undefined or critical unspecified behaviour

(c) The Motor Industry Research Association, 2012

QA C Source Code Analyser 8.1.2
MISRA C:2012 Compliance Module 1.0
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