C++: Add implicit read of the 'm_strPath' member.

Author: MathiasVP

cpp/ql/lib/semmle/code/cpp/models/Models.qll

@@ -52,3 +52,4 @@ private import implementations.ZMQ
 private import implementations.Win32CommandExecution
 private import implementations.CA2AEX
 private import implementations.CComBSTR
+private import implementations.CPathT

cpp/ql/lib/semmle/code/cpp/models/implementations/CPathT.qll

@@ -0,0 +1,16 @@
+private import cpp
+private import semmle.code.cpp.ir.dataflow.FlowSteps
+private import semmle.code.cpp.dataflow.new.DataFlow
+
+/** The `CPathT` class from the Microsoft "Active Template Library". */
+class CPathT extends Class {
+  CPathT() { this.hasGlobalName("CPathT") }
+}
+
+private class MStrPath extends Field {
+  MStrPath() { this.getDeclaringType() instanceof CPathT and this.hasName("m_strPath") }
+}
+
+private class MStrPathTaintInheritingContent extends TaintInheritingContent, DataFlow::FieldContent {
+  MStrPathTaintInheritingContent() { this.getField() instanceof MStrPath }
+}

cpp/ql/test/library-tests/dataflow/taint-tests/atl.cpp

@@ -664,45 +664,45 @@ void test_CPathT() {
   char* x = indirect_source<char>();
   CPath p(x);
   sink(static_cast<char*>(p)); // $ MISSING: ir
-  sink(p.m_strPath); // $ MISSING: ir
+  sink(p.m_strPath); // $ ir
 
   CPath p2(p);
-  sink(p2.m_strPath); // $ MISSING: ir
+  sink(p2.m_strPath); // $ ir
 
   {
     CPath p;
     p.AddExtension(x);
-    sink(p.m_strPath); // $ MISSING: ir
+    sink(p.m_strPath); // $ ir
   }
   {
     CPath p;
     p.Append(x);
-    sink(p.m_strPath); // $ MISSING: ir
+    sink(p.m_strPath); // $ ir
 
     CPath p2;
     p2 += p;
-    sink(p.m_strPath); // $ MISSING: ir
+    sink(p.m_strPath); // $ ir
 
     CPath p3;
     p3 += x;
-    sink(p.m_strPath); // $ MISSING: ir
+    sink(p.m_strPath); // $ ir
   }
 
   {
     CPath p;
     p.Combine(x, nullptr);
-    sink(p.m_strPath); // $ MISSING: ir
+    sink(p.m_strPath); // $ ir
   }
   {
     CPath p;
     p.Combine(nullptr, x);
-    sink(p.m_strPath); // $ MISSING: ir
+    sink(p.m_strPath); // $ ir
   }
 
   {
     CPath p;
     auto p2 = p.CommonPrefix(x);
-    sink(p2.m_strPath); // $ MISSING: ir
+    sink(p2.m_strPath); // $ ir
     sink(p2.GetExtension()); // $ ir
   }
 }