C++: HashCons library

change-notes/1.19/analysis-cpp.md

@@ -0,0 +1,20 @@
+# Improvements to C/C++ analysis
+
+## General improvements
+
+## New queries
+
+| **Query**                   | **Tags**  | **Purpose**                                                        |
+|-----------------------------|-----------|--------------------------------------------------------------------|
+| *@name of query (Query ID)* | *Tags*    |*Aim of the new query and whether it is enabled by default or not*  |
+
+## Changes to existing queries
+
+| **Query**                  | **Expected impact**    | **Change**                                                       |
+|----------------------------|------------------------|------------------------------------------------------------------|
+| *@name of query (Query ID)*| *Impact on results*    | *How/why the query has changed*                                  |
+
+
+## Changes to QL libraries
+
+* Added a hash consing library for structural comparison of expressions.

cpp/ql/src/filters/ImportAdditionalLibraries.ql

@@ -14,6 +14,7 @@ import semmle.code.cpp.dataflow.DataFlow2
 import semmle.code.cpp.dataflow.DataFlow3
 import semmle.code.cpp.dataflow.DataFlow4
 import semmle.code.cpp.dataflow.TaintTracking
+import semmle.code.cpp.valuenumbering.HashCons
 
 from File f, string tag
 where none()