Understand the MISRA-C Guidelines and Compliance Goals
Before integrating MISRA-C checkers into your firmware build, familiarize yourself with the MISRA-C guidelines relevant to your project. Each guideline has a rationale, examples, and the compliance criteria necessary for fulfilling safety-critical requirements.
Discuss with your team to identify which MISRA-C rules are most critical to your project, and prioritize them. This helps focus the integration on meeting your immediate safety requirements while also ensuring greater consistency across the project.
Select and Configure the Appropriate Static Analysis Tool
Choose a static analysis tool that supports MISRA-C compliance. Popular ones include PC-lint, Coverity, and Cppcheck. Ensure that the chosen tool has adequate support and an easy integration path for your build environment.
Once you have your tool, configure it to reflect your compliance priorities. This usually involves setting up rule sets that correspond to the MISRA-C guidelines you target. Refer to your tool's documentation on how to apply these rules.
# Example configuration snippet for a static analyzer
[misc]
misra-rules = Rule1, Rule2, Rule3
enable-misra = true
Integrate the Static Analysis Tool into the Build Process
Begin by scripting the static analysis tool to run as part of your build process. If your build system uses Makefiles, Ant, or CMake, you can add a target that runs the static analysis as part of the build process. This ensures that any code you compile meets the MISRA-C requirements.
Test the integration independently first to ensure the static analysis tool detects MISRA-C violations without compiling errors. Confirm that all outputs are logged properly for further review.
# Example Makefile snippet
misra-check:
static-analyzer --config=path/to/config/file $(SRC_FILES)
Address Violations and Iterate
After running the static analysis tool, you will likely encounter a lot of violations at first. Prioritize fixing these by focusing on high-severity issues that could affect system stability or safety first.
Understand that not all violations can or should be fixed immediately, especially if they concern legacy code. Document these to address them in future iterations.
Automate Reports for Continuous Integration (CI)
Integrate your MISRA-C checks into your CI/CD pipeline to maintain code quality over time. This can be done by generating reports that are automatically evaluated against compliance thresholds after each build.
Tools like Jenkins, GitLab CI/CD, or Travis CI can help automate this process. Ensure that any violations beyond acceptable levels result in build failures, prompting immediate attention from developers.
# Example GitLab CI/CD configuration
misra_check:
script:
- static-analyzer --config=path/to/config/file $(SRC_FILES)
artifacts:
paths:
- static_analyzer_report.xml
only:
- master
- merge_requests
Maintain and Reassess
As your codebase evolves, periodically reassess your MISRA-C integration strategy. Software updates and the introduction of new libraries or functions may necessitate revisiting your MISRA-C priorities or adding new checks.
Regularly seek feedback from your team and invest in additional training if necessary to ensure everyone is up to speed with best practices for meeting MISRA-C compliance.
