[PATCH] D64680: [analyzer] MallocChecker: Prevent Integer Set Library false positives

Fri Jul 12 22:33:48 PDT 2019

NoQ added a comment.

In D64680#1584130 <https://reviews.llvm.org/D64680#1584130>, @Charusso wrote:

> Here is an example of the mentioned use-after-free by pointer-escaping as an argument:
>  https://llvm.org/reports/scan-build/report-DeclBase.cpp-getFromVoidPointer-0-1.html#EndPath

Not sure how is this false positive related to that report, but this false positive looks super weird and i'd love to debug it more.

P.S. I think you should attach the report to Phabricator directly, as the link will expire as soon as these reports get regenerated.

================
Comment at: clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp:56-58
+    // If this checker does not model the allocation.
+    DoNothing,
+    // Reference to allocated memory.
----------------
Charusso wrote:
> NoQ wrote:
> > We already have `Escaped`, it's the same thing in practice.
> It is more strict than `Escaped`, also it made for the purpose of `PSK_EscapeOther` to force out we lost the entire pointer and do not make false warnings of use-after-free.
How exactly is it more strict? I.e., what warnings are getting suppressed by you that aren't going to be suppressed if you use `Escaped` instead?

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https://reviews.llvm.org/D64680