MISRA C:2012  Rule-5.3:  (Required)			An identifier declared in an inner scope shall not hide an identifier declared in an outer scope

Amplification:

An identifier declared in an inner scope shall be distinct from any identifier declared in an outer scope.

The definition of distinct depends on the implementation and 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:

#pragma PRQA_MESSAGES_OFF 2983

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

struct ST0503
{
   int16_t a;
   int16_t b;
};

enum TE0503 { enx1, enx2, enx3 };
static enum TE0503 enva;

extern int16_t rule_0503( void )
{
   int16_t enx1;                                        /* 3334 */      /* Non-compliant - type hides object */

   struct ST0503                                        /* 2547 */      /* Non-compliant - tag hides tag     */
   {
      uint16_t x;
      uint16_t y;
   } sl;

   return 1;
}

QAC messages that encompass this guideline:

2547	This declaration of tag '%s' hides a more global declaration.
3334	This declaration of '%s' hides a more global declaration.

(c) The Motor Industry Research Association, 2012

QA C Source Code Analyser 8.1.2 MISRA C:2012 Compliance Module 1.0 © 2013 Programming Research www.programmingresearch.com

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