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Fix RULE-7-0-2 false positives: UnknownType and reference-to-bool dereference - #1183

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Fix RULE-7-0-2 false positives: UnknownType and reference-to-bool dereference#1183
castler wants to merge 1 commit into
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castler:fix-rule-7-0-2-compiler-generated

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@castler castler commented Aug 25, 2026

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Description

NoImplicitBoolConversion.ql flagged two systematic false-positive shapes:

  1. Conversions whose source expression type could not be resolved to a concrete type (UnknownType). This occurs only in template-dependent contexts the extractor cannot resolve, e.g. a constexpr bool variable template initialized from another dependent variable template such as std::conjunction_v<...>, or a noexcept(...) specifier built the same way.

  2. Reference-dereference conversions (bool&/bool&& -> bool). getUnspecifiedType() resolves typedefs/specifiers but does not strip reference qualification, so a bool&/bool&& is not recognised as already being bool. This is most commonly synthesized by the compiler for structured binding decomposition (auto [a, b] = pair_or_tuple_expr; where b is bool), which is not a real conversion since the referenced value is already a bool.

This mirrors the same root-cause pattern already fixed for the sibling rule RULE-7-0-1 in 6f872c7 ("Fix RULE-7-0-1 false positives for bool-to- reference bindings"), applied here to the reverse conversion direction.

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:
    • RULE-7-0-2

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!)

…eference

NoImplicitBoolConversion.ql flagged two systematic false-positive shapes:

1. Conversions whose source expression type could not be resolved to a
   concrete type (UnknownType). This occurs only in template-dependent
   contexts the extractor cannot resolve, e.g. a `constexpr bool` variable
   template initialized from another dependent variable template such as
   `std::conjunction_v<...>`, or a `noexcept(...)` specifier built the same
   way.

2. Reference-dereference conversions (`bool&`/`bool&&` -> `bool`).
   `getUnspecifiedType()` resolves typedefs/specifiers but does not strip
   reference qualification, so a `bool&`/`bool&&` is not recognised as
   already being `bool`. This is most commonly synthesized by the compiler
   for structured binding decomposition (`auto [a, b] = pair_or_tuple_expr;`
   where `b` is `bool`), which is not a real conversion since the referenced
   value is already a `bool`.

This mirrors the same root-cause pattern already fixed for the sibling rule
RULE-7-0-1 in 6f872c7 ("Fix RULE-7-0-1 false positives for bool-to-
reference bindings"), applied here to the reverse conversion direction.
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