A Guide to MISRA C:2012 Permits for Deviation and Compliance
What is Misra C and why is it important?
Misra C is a set of coding standards and guidelines for developing software in the C programming language, especially for embedded systems. Embedded systems are devices that have a specific function within a larger system, such as cars, medical equipment, robots, etc. Embedded systems often have limited resources, such as memory, processing power, or battery life, and need to operate reliably and safely under various conditions.
Misra C 2012 Pdf 160
Misra C was created by the Motor Industry Software Reliability Association (MISRA) in 1998, with the aim of improving the quality, reliability, portability, and maintainability of software written in C. Since then, Misra C has been widely adopted by various industries and sectors that use embedded systems, such as automotive, aerospace, defense, telecommunications, etc. Misra C has also been recognized as an international standard by ISO (International Organization for Standardization).
Misra C provides a set of rules and guidelines that cover various aspects of coding in C, such as syntax, data types, operators, expressions, control structures, functions, pointers, arrays, etc. The rules and guidelines are based on best practices and common pitfalls that have been identified by experts and practitioners in the field. By following Misra C, developers can avoid errors, bugs, vulnerabilities, inefficiencies, and inconsistencies in their code. This can lead to better performance, security, compatibility, readability, and testability of their software.
What are the main features of Misra C 2012?
Misra C 2012 is the latest version of Misra C, which was released in March 2013. It is also known as MISRA-C:2012 or MISRA-C3. It is based on the ISO/IEC 9899:1999 standard for the C programming language (also known as C99).
Misra C 2012 introduces several changes and improvements from previous versions of Misra C (such as MISRA-C:2004 or MISRA-C:1998). Some of the main features of Misra C 2012 are:
It contains 143 rules and 16 directives that cover various aspects of coding in C. The rules are classified into three categories: mandatory, required, and advisory. The directives are classified into two categories: mandatory and advisory. The mandatory rules and directives must be followed in all cases, the required rules and directives should be followed unless there is a good reason not to, and the advisory rules and directives may be followed or not depending on the context and judgment of the developer.
It allows the use of some features of C99 that were previously forbidden or discouraged by Misra C, such as variable-length arrays, designated initializers, compound literals, etc. However, it also restricts or prohibits the use of some other features of C99 that are considered unsafe or unnecessary, such as flexible array members, complex numbers, variable arguments, etc.
It introduces the concept of deviations, which are exceptions to the rules and directives that can be applied in specific situations where following them would be impractical or detrimental. Deviations must be justified and documented by the developer, and must be approved by an independent authority.
It provides more detailed explanations and examples for each rule and directive, as well as references to relevant sources and standards. It also provides more flexibility and clarity for applying the rules and directives in different contexts and scenarios.
How to use Misra C 2012 in your projects?
If you want to use Misra C 2012 in your projects, you need to follow these steps:
Obtain a copy of Misra C 2012 PDF 160, which is the official document that contains the rules and directives of Misra C 2012. You can purchase it from the MISRA website (https://www.misra.org.uk) or from other authorized distributors.
Choose a subset of Misra C 2012 that is suitable for your project. You can use the full set of Misra C 2012 rules and directives, or you can select a subset that meets your specific needs and requirements. You can also define your own subset by adding or removing rules and directives from the full set. However, you need to ensure that your subset is consistent, coherent, and compliant with Misra C 2012.
Apply the chosen subset of Misra C 2012 to your code. You can use manual methods, such as code reviews, inspections, audits, etc., or you can use automated tools, such as static analyzers, code checkers, compilers, etc., that support Misra C 2012. You need to ensure that your code conforms to the rules and directives of your chosen subset of Misra C 2012.
Document and justify any deviations from your chosen subset of Misra C 2012. If you encounter any situations where following a rule or directive would be impractical or detrimental for your project, you can apply a deviation that allows you to violate or modify the rule or directive. However, you need to document and justify each deviation clearly and convincingly, and obtain approval from an independent authority.
Test and verify your code. You need to ensure that your code meets the functional and non-functional requirements of your project, as well as the quality and reliability standards of Misra C 2012. You can use various testing and verification methods, such as unit testing, integration testing, system testing, regression testing, etc., as well as tools that support Misra C 2012.
What are the tools and resources for Misra C 2012?
There are many tools and resources that can help you use Misra C 2012 in your projects. Some of them are:
Software tools that support Misra C 2012. These are tools that can check, analyze, compile, test, or verify your code against Misra C 2012 rules and directives. Some examples of these tools are: PC-lint (https://gimpel.com), LDRA Testbed (https://ldra.com), PRQA QA-C (https://www.perforce.com), Parasoft C/C++test (https://www.parasoft.com), etc.
What are the challenges and limitations of Misra C 2012?
While Misra C 2012 has many benefits and advantages for developing software in C, it also has some challenges and limitations that need to be considered and addressed. Some of the main challenges and limitations of Misra C 2012 are:
It can be difficult and time-consuming to learn and apply Misra C 2012 correctly and consistently. Misra C 2012 contains many rules and directives that cover various aspects of coding in C, some of which are complex, subtle, or ambiguous. Developers need to have a good understanding of the rationale and implications of each rule and directive, as well as the skills and experience to apply them in different contexts and scenarios. Developers also need to keep up with the updates and revisions of Misra C 2012, as well as the feedback and interpretations from the MISRA community.
It can be costly and cumbersome to obtain and use Misra C 2012 tools and resources. Misra C 2012 PDF 160, which is the official document that contains the rules and directives of Misra C 2012, is not freely available and requires a license fee to purchase. Software tools that support Misra C 2012, such as static analyzers, code checkers, compilers, etc., are also not free and may require additional licenses or subscriptions. Online resources that provide information and guidance on Misra C 2012, such as websites, blogs, forums, articles, videos, podcasts, etc., may not be comprehensive, accurate, or up-to-date.
It can be restrictive and inflexible to follow Misra C 2012 strictly and rigidly. Misra C 2012 imposes many constraints and requirements on coding in C, some of which may not be suitable or optimal for every project or situation. Developers may encounter cases where following a rule or directive would be impractical or detrimental for their project, such as performance issues, compatibility issues, legacy issues, etc. Developers may also have different preferences or opinions on coding style, conventions, or practices that may conflict with Misra C 2012.
How to overcome the challenges and limitations of Misra C 2012?
Despite the challenges and limitations of Misra C 2012, there are ways to overcome them and use Misra C 2012 effectively and efficiently in your projects. Some of the tips and best practices for overcoming the challenges and limitations of Misra C 2012 are:
Invest in training and education on Misra C 2012. Developers should learn the basics and fundamentals of Misra C 2012, as well as the advanced and specific topics that are relevant for their projects. Developers should also seek feedback and guidance from experts and mentors who have experience and knowledge on Misra C 2012. Developers should also participate in online or offline communities and events that discuss and share information and insights on Misra C 2012.
Select and use appropriate tools and resources for Misra C 2012. Developers should choose tools and resources that are reliable, compatible, affordable, and accessible for their projects. Developers should also compare and evaluate different options and alternatives for tools and resources that support Misra C 2012. Developers should also update and maintain their tools and resources regularly to ensure that they are consistent with the latest version of Misra C 2012.
Apply deviations judiciously and transparently for Misra C 2012. Developers should use deviations sparingly and only when necessary for their projects. Developers should also document and justify each deviation clearly and convincingly, as well as obtain approval from an independent authority. Developers should also review and revise their deviations periodically to ensure that they are still valid and relevant for their projects.
What are the future prospects and trends for Misra C 2012?
Misra C 2012 is a dynamic and evolving standard that reflects the current state-of-the-art and best practices for developing software in C. However, it is also subject to change and improvement based on the feedback from users, developers, researchers, and industry experts. Some of the future prospects and trends for Misra C 2012 are:
Misra C 2020. This is the next version of Misra C that is expected to be released in 2020. It is based on the ISO/IEC 9899:2011 standard for the C programming language (also known as C11). It will introduce new rules and directives that cover the new features and enhancements of C11, such as atomic operations, threads, alignment, etc. It will also revise and clarify some of the existing rules and directives of Misra C 2012, as well as address some of the issues and feedback from the users and developers.
Misra C for security. This is a proposed extension of Misra C that focuses on the security aspects of developing software in C. It will provide additional rules and directives that cover various security topics, such as cryptography, authentication, authorization, encryption, decryption, etc. It will also provide guidance and recommendations on how to use Misra C to prevent or mitigate common security threats and vulnerabilities, such as buffer overflows, injection attacks, denial-of-service attacks, etc.
Misra C for other languages. This is a possible expansion of Misra C that applies to other programming languages that are related or similar to C, such as C++, Java, Python, etc. It will provide rules and directives that are specific or adapted to each language, as well as rules and directives that are common or shared among them. It will also provide compatibility and interoperability guidelines for using different languages in the same project or system.
How to access and download Misra C 2012 PDF 160?
Misra C 2012 PDF 160 is the official document that contains the rules and directives of Misra C 2012. It is a PDF file that has 160 pages and is formatted according to the ISO standards for technical documents. It is the primary and authoritative source of information and guidance on Misra C 2012.
If you want to access and download Misra C 2012 PDF 160, you need to follow these steps:
Visit the MISRA website (https://www.misra.org.uk) or one of its authorized distributors (such as https://www.his.se or https://www.sae.org). You can find a list of authorized distributors on the MISRA website.
Select the option to purchase Misra C 2012 PDF 160. You can choose between a single-user license or a multi-user license, depending on your needs and preferences. You can also choose between a digital download or a physical delivery, depending on your location and convenience.
Complete the payment process using your preferred method, such as credit card, PayPal, bank transfer, etc. You will need to provide some personal and professional details, such as your name, email address, company name, etc., for verification and confirmation purposes.
Receive an email confirmation with a link to download Misra C 2012 PDF 160. You will also receive a license key that you will need to enter when opening the PDF file for the first time. You can download the PDF file to your computer or device and save it for future use.
Open the PDF file using a compatible PDF reader, such as Adobe Acrobat Reader (https://get.adobe.com/reader). Enter the license key when prompted and agree to the terms and conditions of use. You can then view, print, or copy the content of Misra C 2012 PDF 160 as per your license agreement.
What is the content and structure of Misra C 2012 PDF 160?
Misra C 2012 PDF 160 has a clear and consistent content and structure that makes it easy to read and understand. It consists of six main sections and several appendices that cover various topics related to Misra C 2012. The main sections are:
Section 1: Introduction. This section provides an overview of Misra C and its history, purpose, scope, benefits, and limitations. It also explains the terminology, notation, classification, and deviation mechanisms used in Misra C 2012.
Section 2: Environment. This section describes the environment in which Misra C 2012 is intended to be used, such as the target language (C99), the target systems (embedded systems), the target users (developers), and the target tools (software tools).
Section 3: General guidelines. This section provides general guidelines that apply to all aspects of coding in C using Misra C 2012. It covers topics such as code layout, comments, identifiers, literals, types, conversions, operators, expressions, statements, functions, etc.
Section 4: Specific guidelines. This section provides specific guidelines that apply to particular aspects of coding in C using Misra C 2012. It covers topics such as preprocessor directives, pointers and arrays, structures and unions, enumerations and bit-fields, dynamic memory management, input/output, recursion, etc.
Section 5: Compliance. This section explains how to achieve and demonstrate compliance with Misra C 2012. It covers topics such as compliance metrics, compliance documentation, compliance verification, compliance tools, etc.
Section 6: References. This section provides references to relevant sources and standards that are related or complementary to Misra C 2012. It includes references to ISO standards, MISRA publications, C books, C websites, etc.
The appendices are:
Appendix A: Summary of guidelines. This appendix provides a summary of all the rules and directives of Misra C 2012 in a tabular format.
Appendix B: Rationale for guidelines. This appendix provides a rationale for each rule and directive of Misra C 2012 in terms of its benefits and drawbacks.
Appendix C: Example deviations. This appendix provides some examples of deviations from Misra C 2012 rules and directives, along with their justification and documentation.
Appendix D: Example subset. This appendix provides an example of a subset of Misra C 2012 rules and directives that is suitable for a specific project or situation.
Appendix E: Glossary. This appendix provides definitions of key terms and concepts used in Misra C 2012.
Appendix F: Bibliography. This appendix provides a list of additional sources and standards that are related or complementary to Misra C 2012.
Appendix G: Index. This appendix provides an index of keywords and topics covered in Misra C 2012.
How to use Misra C 2012 PDF 160 as a reference?
Misra C 2012 PDF 160 is a valuable and useful reference for developers who want to use Misra C 2012 in their projects. It provides comprehensive and detailed information and guidance on Misra C 2012 rules and directives, as well as examples and explanations for each one. It also provides tips and best practices for applying Misra C 2012 in different contexts and scenarios.
If you want to use Misra C 2012 PDF 160 as a reference, you can follow these tips:
Use the table of contents, the summary of guidelines, the index, or the search function to find the rule or directive that you are looking for.
Read the rule or directive carefully and understand its rationale and implications. Pay attention to the classification, notation, and deviation mechanisms that are used for each rule or directive.
Look at the examples and explanations that are provided for each rule or directive. They can help you understand how to apply the rule or directive correctly and consistently in your code.
Refer to the references, the rationale, the deviations, or the subset that are provided for each rule or directive. They can help you learn more about the background, benefits, drawbacks, exceptions, or alternatives for each rule or directive.
Use the general guidelines, the specific guidelines, the compliance guidelines, or the appendices as additional resources that can help you use Misra C 2012 effectively and efficiently in your projects.
Conclusion
Misra C 2012 is a set of coding standards and guidelines for developing software in C, especially for embedded systems. It aims to improve the quality, reliability, portability, and maintainability of software written in C. It is based on the ISO/IEC 9899:1999 standard for the C programming language (C99) and contains 143 rules and 16 directives that cover various aspects of coding in C.
Misra C 2012 has many benefits and advantages for developers who use C in their projects, such as avoiding errors, bugs, vulnerabilities, inefficiencies, and inconsistencies in their code. It also has some challenges and limitations that need to be considered and addressed, such as learning and applying Misra C 2012 correctly and consistently, obtaining and using Misra C 2012 tools and resources, following Misra C 2012 strictly and rigidly, etc.
Misra C 2012 PDF 160 is the official document that contains the rules and directives of Misra C 2012. It is a PDF file that has 160 pages and is formatted according to the ISO standards for technical documents. It is the primary and authoritative source of information and guidance on Misra C 2012. It can be accessed and downloaded from the MISRA website (https://www.misra.org.uk) or from other authorized distributors.
Misra C 2012 PDF 160 has a clear and consistent content and structure that makes it easy to read and understand. It consists of six main sections and several appendices that cover various topics related to Misra C 2012. It also provides detailed explanations and examples for each rule and directive, as well as references to relevant sources and standards. It can be used as a valuable and useful refer