Implement Rule 0-0-1, unreachable statements from DeadCode package

[MichaelRFairhurst]

Description

Implement Rule 0-0-1

Change request type

• Release or process automation (GitHub workflows, internal scripts)
• Internal documentation
• External documentation
• Query files (.ql, .qll, .qls or unit tests)
• External scripts (analysis report or other code shipped as part of a release)

Rules with added or modified queries

• No rules added
• Queries have been added for the following rules:
  • RULE-0-0-1
• Queries have been modified for the following rules:
  • M0-1-1
  • RULE-2-1
  • M15-3-6
  • ERR54-CPP

Release change checklist

A change note (development_handbook.md#change-notes) is required for any pull request which modifies:

• The structure or layout of the release artifacts.
• The evaluation performance (memory, execution time) of an existing query.
• The results of an existing query in any circumstance.

If you are only adding new rule queries, a change note is not required.

Author: Is a change note required?

• Yes
• No

🚨🚨🚨
Reviewer: Confirm that format of shared queries (not the .qll file, the
.ql file that imports it) is valid by running them within VS Code.

• Confirmed

Reviewer: Confirm that either a change note is not required or the change note is required and has been added.

• Confirmed

Query development review checklist

For PRs that add new queries or modify existing queries, the following checklist should be completed by both the author and reviewer:

Author

• Have all the relevant rule package description files been checked in?
• Have you verified that the metadata properties of each new query is set appropriately?
• Do all the unit tests contain both "COMPLIANT" and "NON_COMPLIANT" cases?
• Are the alert messages properly formatted and consistent with the style guide?
• Have you run the queries on OpenPilot and verified that the performance and results are acceptable?
  As a rule of thumb, predicates specific to the query should take no more than 1 minute, and for simple queries be under 10 seconds. If this is not the case, this should be highlighted and agreed in the code review process.
• Does the query have an appropriate level of in-query comments/documentation?
• Have you considered/identified possible edge cases?
• Does the query not reinvent features in the standard library?
• Can the query be simplified further (not golfed!)

Reviewer

• Have all the relevant rule package description files been checked in?
• Have you verified that the metadata properties of each new query is set appropriately?
• Do all the unit tests contain both "COMPLIANT" and "NON_COMPLIANT" cases?
• Are the alert messages properly formatted and consistent with the style guide?
• Have you run the queries on OpenPilot and verified that the performance and results are acceptable?
  As a rule of thumb, predicates specific to the query should take no more than 1 minute, and for simple queries be under 10 seconds. If this is not the case, this should be highlighted and agreed in the code review process.
• Does the query have an appropriate level of in-query comments/documentation?
• Have you considered/identified possible edge cases?
• Does the query not reinvent features in the standard library?
• Can the query be simplified further (not golfed!)

[Copilot]

Pull request overview

This PR implements MISRA C++ 2023 Rule 0-0-1, which prohibits unreachable statements in functions. The implementation leverages custom reachability analysis that accounts for MISRA-specific semantics (e.g., both operands of && are reachable) and integrates with exception handling analysis.

Key changes:

• New query UnreachableStatement.ql implements MISRA-specific reachability analysis for detecting unreachable code
• Refactored catch block shadowing logic into shared Shadowing.qll library for reuse
• Enhanced UnreachableCode.qll to properly handle compiler-generated Handler blocks in CFG analysis

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
rules.csv	Updated rule metadata to reference DeadCode3 package
rule_packages/cpp/DeadCode3.json	New package definition for RULE-0-0-1 query
cpp/misra/test/rules/RULE-0-0-1/test.cpp	Comprehensive test cases covering various unreachability scenarios
cpp/misra/test/rules/RULE-0-0-1/UnreachableStatement.qlref	Query reference for testing
cpp/misra/test/rules/RULE-0-0-1/UnreachableStatement.expected	Expected test results with location issues
cpp/misra/src/rules/RULE-0-0-1/UnreachableStatement.ql	Main query implementing MISRA reachability semantics
cpp/common/src/codingstandards/cpp/rules/catchblockshadowing/CatchBlockShadowing.qll	Refactored to use shared Shadowing library
cpp/common/src/codingstandards/cpp/exclusions/cpp/RuleMetadata.qll	Added DeadCode3 package integration
cpp/common/src/codingstandards/cpp/exclusions/cpp/DeadCode3.qll	Auto-generated exclusions file for DeadCode3 package
cpp/common/src/codingstandards/cpp/exceptions/Shadowing.qll	New shared library for catch block shadowing detection
cpp/common/src/codingstandards/cpp/deadcode/UnreachableCode.qll	Enhanced to handle Handler blocks correctly
cpp/common/src/codingstandards/cpp/ast/Catch.qll	New utility functions for catch block analysis
change_notes/2025-12-15-update-catch-block-shadowing-dead-code.md	Change note with spelling error

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.