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Description

In github/codeql#21313 we fixed a performance problem in SimpleRangeAnalysis. As part of that we reduced the limit for when range analysis decides to bail out and reduces precision because it expects too many bounds prior to the main range analysis recursion.

Because this test function produces so many bounds (because it's thousands of lines of code with lots of sequential ìfs) we now hit this limit.

I suggest you rewrite this test in the future to better reflect real-world code. This will make range analysis perform just like it did before.

Change request type

  • Release or process automation (GitHub workflows, internal scripts)
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    • rule number here
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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?
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  • Does the query have an appropriate level of in-query comments/documentation?
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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 February 11, 2026 20:06
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Pull request overview

This PR updates the INT34-C C/CERT test expectations to account for the reduced precision behavior introduced by the SimpleRangeAnalysis performance fix (github/codeql#21313), ensuring the test suite continues to pass under the new analysis limits.

Changes:

  • Mark two previously-COMPLIANT shift cases as expected false positives in INT34-C/test.c.
  • Update the .expected baseline to reflect less precise (higher) inferred upper bounds from range analysis.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File Description
c/cert/test/rules/INT34-C/test.c Adjusts compliance annotations for two shift cases that now trigger alerts due to reduced range-analysis precision.
c/cert/test/rules/INT34-C/ExprShiftedbyNegativeOrGreaterPrecisionOperand.expected Updates expected query results/upper-bound values (and adds any newly-triggered results) to match current analysis output.
Comments suppressed due to low confidence (1)

c/cert/test/rules/INT34-C/test.c:361

  • Test markers elsewhere in this repo predominantly use underscore-separated tags like COMPLIANT[FALSE_POSITIVE]/NON_COMPLIANT[FALSE_NEGATIVE]. To keep consistency (and avoid any tooling that might treat spaces inside the tag unexpectedly), consider changing COMPLIANT[FALSE POSITIVE] to COMPLIANT[FALSE_POSITIVE] here.
  lhs12 << rhs13; // COMPLIANT[FALSE POSITIVE]: lhs12's precision is strictly greater than rhs13 (FP because range analysis reduced precision for performance reasons)
  lhs12 << rhs14; // COMPLIANT[FALSE POSITIVE]: lhs12's precision is strictly greater than rhs14 (FP because range analysis reduced precision for performance reasons)

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