C++: Add change note.

MathiasVP · MathiasVP · commit 497592a4d478 · 2024-02-16T13:36:25.000+01:00
diff --git a/cpp/ql/src/change-notes/2024-02-16-modelled-functions-block-flow.md b/cpp/ql/src/change-notes/2024-02-16-modelled-functions-block-flow.md
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+---
+category: minorAnalysis
+---
+* The new C/C++ dataflow and taint-tracking libraries (`semmle.code.cpp.dataflow.new.DataFlow` and `semmle.code.cpp.dataflow.new.TaintTracking`) now implicitly assume that dataflow and taint modelled via `DataFlowFunction` and `TaintFunction` always fully overwrite their buffers and thus act as flow barriers. As a result, many dataflow and taint-tracking queries now produce fewer false positives. To remove this assumption and go back to the previous behavior for a given model, one can override the new `isPartialWrite` predicate.

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 +---
 +category: minorAnalysis
 +---
 +* The new C/C++ dataflow and taint-tracking libraries (`semmle.code.cpp.dataflow.new.DataFlow` and `semmle.code.cpp.dataflow.new.TaintTracking`) now implicitly assume that dataflow and taint modelled via `DataFlowFunction` and `TaintFunction` always fully overwrite their buffers and thus act as flow barriers. As a result, many dataflow and taint-tracking queries now produce fewer false positives. To remove this assumption and go back to the previous behavior for a given model, one can override the new `isPartialWrite` predicate.