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Fix FPs for unsigned operations in INT30-C and RULE-8-20-1#1140

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mbaluda wants to merge 4 commits into
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mbaluda-FP-wrap
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Fix FPs for unsigned operations in INT30-C and RULE-8-20-1#1140
mbaluda wants to merge 4 commits into
mainfrom
mbaluda-FP-wrap

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@mbaluda mbaluda commented Jun 18, 2026

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Description

This pull request addresses false positives in the detection of unsigned integer operations that may wrap around, specifically for division and remainder assignments (/= and %=), and updates relevant tests and documentation. The main changes include refining the logic in the query to group division and remainder operations, updating test cases to reflect compliant usage, and documenting the fixes.

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 number here
  • Queries have been modified for the following rules:
    • INT30-C
    • RULE-8-20-1

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 AI review requested due to automatic review settings June 18, 2026 13:16
GitHub Advanced Security started work on behalf of mbaluda June 18, 2026 13:16 View session
@mbaluda mbaluda requested a review from a team June 18, 2026 13:17
GitHub Advanced Security finished work on behalf of mbaluda June 18, 2026 13:18

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Pull request overview

This PR aims to reduce false positives for unsigned division/remainder compound assignments (/= and %=) in the shared “unsigned operation with constant operands wraps” logic, which is reused by INT30-C and RULE-8-20-1.

Changes:

  • Update the shared query predicate to exclude all division/remainder operations via DivOrRemOperation (including assignment forms).
  • Add new C and C++ test cases marking /, /=, %, and %= as COMPLIANT under exception 2.
  • Add a change note documenting the FP fix for both affected rules.

Review checklist items uncertain / not verified in this automated review:

  • Running the shared queries in VS Code to confirm output format validity.
  • Performance/results validation on OpenPilot.
Show a summary per file
File Description
cpp/common/src/codingstandards/cpp/rules/unsignedoperationwithconstantoperandswraps/UnsignedOperationWithConstantOperandsWraps.qll Broadens the exception-2 exclusion to cover division/remainder compound assignments via DivOrRemOperation.
cpp/common/test/rules/unsignedoperationwithconstantoperandswraps/test.cpp Adds /, /=, %, %= COMPLIANT tests (currently introduced in a way that breaks compilation; see PR comments).
c/common/test/rules/unsignedoperationwithconstantoperandswraps/test.c Mirrors the C++ test additions (currently introduced in a way that breaks compilation; see PR comments).
change_notes/2026-06-18-fix-fp-misra-c++-8-20-1.md Documents the FP fix for INT30-C and RULE-8-20-1.

Copilot's findings

  • Files reviewed: 4/4 changed files
  • Comments generated: 2

mbaluda and others added 2 commits June 18, 2026 15:24
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
GitHub Advanced Security started work on behalf of mbaluda June 18, 2026 13:25 View session
@mbaluda mbaluda requested a review from Copilot June 18, 2026 13:25
GitHub Advanced Security started work on behalf of mbaluda June 18, 2026 13:25 View session
GitHub Advanced Security finished work on behalf of mbaluda June 18, 2026 13:26
GitHub Advanced Security finished work on behalf of mbaluda June 18, 2026 13:27

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Copilot's findings

  • Files reviewed: 4/4 changed files
  • Comments generated: 0 new

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2 participants