AUTOSAR for dummies - #12 - AUTOSAR C Rules

Below are some of the C rules mandated by AUTOSAR

Declaration

There should not be more than one declaration per line.

 Eg uint8 blockIndex, lastBlock; /*violation*/

Brackets

Brackets shall always be used in complex expressions even if the C priority rules do not necessarily demand this for operators. This also applies to expressions evaluated by the pre-processor

Eg. if ( (counter1 > 0) || (counter2 < 0) )

Comments

Function comments shall be positioned in front of the function header. The function comments shall be above the functions in the C file. The function comments may also be in the H file.

Eg.

/***********************************************************

/* Function name: MyFunc( uint8 X)

/* Description: Short Description, including preconditions

/* Parameter X : Description

/* Return value: None

/* Remarks: global variables used, side effects

/***********************************************************/ Void MyFunc( uint8 X)

{

Protection against multiple inclusion

Each header file shall protect itself against multiple inclusion.

Eg.

#ifndef FILENAME_H #define FILENAME_H

.....

#endif /* FILENAME_H */

Commenting violations:

Violations of MISRA rules shall be commented and reasoned at the corresponding code line.

Violations of AUTOSAR C programming guidelines shall be commented and reasoned at the corresponding code line.

Header includes

Header files which are a part of predefined program libraries shall be included using

<>.

Header files which are a part of the source code generated in the software project shall be included with "".

Eg.

#include ;

#include "Eep.h";

Inclusion of own header file

Each module shall include its own header file.

Multiple assignments

Multiple assignments shall not be done.

Eg.

x = y = z; /* violation */

Explicit definition of types

Each self-defined type has to have an explicit type declaration even if there is only one variable of this type.

Eg.

typedef struct

{

uint16 Position; uint8 Direction;

} MotorType;

static MotorType MotorData;

to be continued..