EWMISRAC:2004-1
IAR Embedded Workbench®
MISRA C:2004
Reference Guide
EWMISRAC:2004-1
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EDITION NOTICE
Third edition: March 2008
Part number: EWMISRAC:2004-1
This guide describes version 1.0 of the IAR Systems implementation of The Motor
Industry Software Reliability Association’s Guidelines for the Use of the C Language
in Critical Systems (the MISRA-C:2004 standard), including the MISRA-C:2004
Technical Corrigendum 1, dated 17 July, 2007.
Internal reference: IJOA
EWMISRAC:2004-1
iii
Contents
Preface ...................................................................................................................... 1
Who should read this guide ................................................................. 1
What this guide contains ....................................................................... 1
Other documentation ............................................................................. 2
Document conventions .......................................................................... 2
Introduction .......................................................................................................... 5
Using MISRA C .......................................................................................... 5
Claiming compliance ........................................................................... 5
Implementation and interpretation of the MISRA C rules .... 5
Checking the rules ................................................................................ 6
Enabling MISRA C rules ......................................................................... 7
General IDE options ......................................................................................... 9
MISRA C 2004 ........................................................................................... 9
Compiler IDE options .................................................................................... 11
MISRA C 2004 ......................................................................................... 11
Command line options .................................................................................. 13
Options summary ................................................................................... 13
Descriptions of options ........................................................................ 13
MISRA C:2004 rules reference .................................................................. 15
Summary of rules .................................................................................. 15
Group 1: Environment ....................................................................... 15
Group 2: Language extensions ........................................................... 16
Group 3: Documentation .................................................................... 16
Group 4: Character sets ...................................................................... 16
Group 5: Identifiers ............................................................................ 17
Group 6: Types ................................................................................... 17
Group 7: Constants ............................................................................. 17
Group 8: Declarations and definitions ............................................... 18
EWMISRAC:2004-1
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IAR Embedded Workbench® MISRA C:2004
Reference Guide
Group 9: Initialization ........................................................................ 19
Group 10: Arithmetic type conversions ............................................. 19
Group 11: Pointer type conversions ................................................... 20
Group 12: Expressions ....................................................................... 20
Group 13: Control statement expressions .......................................... 21
Group 14: Control flow ...................................................................... 22
Group 15: Switch statements ............................................................. 23
Group 16: Functions ........................................................................... 23
Group 17: Pointers and arrays ............................................................ 24
Group 18: Structures and unions ........................................................ 24
Group 19: Preprocessing directives ................................................... 25
Group 20: Standard libraries .............................................................. 26
Group 21: Runtime failures ................................................................ 27
Environment rules .................................................................................. 27
Language extensions ............................................................................. 28
Documentation ........................................................................................ 29
Character sets .......................................................................................... 31
Identifiers ................................................................................................... 32
Types ............................................................................................................ 33
Constants ................................................................................................... 35
Declarations and definitions .............................................................. 35
Initialization .............................................................................................. 38
Arithmetic type conversions ............................................................. 39
Pointer type conversions ..................................................................... 42
Expressions ................................................................................................ 43
Control statement expressions ........................................................ 47
Control flow .............................................................................................. 49
Switch statements .................................................................................. 52
Functions .................................................................................................... 53
Pointers and arrays ................................................................................ 56
Structures and unions ........................................................................... 57
Preprocessing directives ...................................................................... 58
Standard libraries ................................................................................... 63
Runtime failures ...................................................................................... 65
EWMISRAC:2004-1
1
Preface
Welcome to the IAR Embedded Workbench® MISRA C:2004 Reference
Guide. This guide includes gives reference information about the IAR Systems
implementation of The Motor Industry Software Reliability Association’s
Guidelines for the Use of the C Language in Critical Systems.
Who should read this guide
You should read this guide if you are developing a software product using the
MISRA-C:2004 rules. In addition, you should have a working knowledge of:
● The C programming language
● The MISRA C subset of the C language
● Application development for safety-critical embedded systems
● The architecture and instruction set of your microcontroller (refer to the chip
manufacturer's documentation)
● The operating system of your host machine.
What this guide contains
Below is a brief outline and summary of the chapters in this guide.
● Introduction explains the benefits of using MISRA C and gives an overview of the
IAR Systems implementation.
● General IDE options describes the general MISRA C options in the IAR Embedded
Workbench IDE.
● Compiler IDE options describes the MISRA C compiler options in the IAR
Embedded Workbench IDE.
● Command line options explains how to set the options from the command line.
● MISRA C:2004 rules reference describes how IAR Systems has interpreted and
implemented the rules given in Guidelines for the Use of the C Language in Critical
Systems, including the MISRA-C:2004 Technical Corrigendum 1, dated 17 July,
2007.
