C/C++: Detect ambiguous assignment of comparison results - #22336
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theinfosecguy wants to merge 1 commit into
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C/C++: Detect ambiguous assignment of comparison results#22336theinfosecguy wants to merge 1 commit into
theinfosecguy wants to merge 1 commit into
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ryao
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Aug 15, 2026
ryao
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While I am happy you did the work for me to get this into a PR and made what appear to be improvements, would you add an Original-patch-by: to the commit message to credit my prior work?
Also, have you run your variant against any major corpora (e.g. Linux, curl, OpenZFS) to verify the lack of FPs in production code, like I did with the original version? If it helps:
| if ((status = read_status() < 0)) // BAD: assigns the comparison result. | ||
| return status; | ||
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| if ((status = read_status()) < 0) // GOOD: assigns first, then compares. |
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This isn't the only good variant. The following is good too, because it shows that the developer really meant it.
if ((status = (read_status() < 0))) // GOOD: explicitly assigns the comparison result.
return status;
| not isExplicitlyGrouped(comparison) and | ||
| occursInCondition(assignment) and | ||
| // Assigning a comparison result to a Boolean is normally intentional. | ||
| not assignment.getLValue().getUnspecifiedType() instanceof BoolType and |
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While this is normally intentional, I believe not isExplicitlyGrouped(comparison) precludes this.
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Adds
cpp/ambiguous-assignment-of-comparisonto flag conditions such as:The query distinguishes this from explicitly grouped assign-then-compare and compare-then-assign expressions. It includes C and C++ tests, query help, and query-suite integration.
Local targeted and neighboring tests pass. The motivating regression is detected, and a run against
git/gitproduced no alerts.Fixes #22286