C++: Call qualifiers are passed by reference #3439
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After github#3382 changed the escape analysis to model qualifiers as escaping, there was an imbalance in the SSA library, where `addressTakenVariable` excludes variables from SSA analysis if they have their address taken but are _not_ passed by reference. This showed up as a missing result in `TOCTOUFilesystemRace.ql`, demonstrated with a test case in github#3432. This commit changes the definition of "pass by reference" to include call qualifiers, which allows SSA modeling of variables that have member function calls on them.
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Here is the SSA code that was out of balance: codeql/cpp/ql/src/semmle/code/cpp/controlflow/SSAUtils.qll Lines 64 to 68 in 8ff045b |
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The CPP-Differences job has finished, and it reports exactly one difference: the restoration of the result that got lost after #3382. |
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After #3382 changed the escape analysis to model qualifiers as escaping, there was an imbalance in the SSA library, where
addressTakenVariableexcludes variables from SSA analysis if they have their address taken but are not passed by reference. This showed up as a missing result inTOCTOUFilesystemRace.ql, demonstrated with a test case in #3432.This PR changes the definition of "pass by reference" to include call qualifiers, which allows SSA modeling of variables that have member function calls on them.