github
diff --git a/‎cpp/ql/lib/semmle/code/cpp/dataflow/ExternalFlow.qll‎
Lines changed: 76 additions & 4 deletions b/‎cpp/ql/lib/semmle/code/cpp/dataflow/ExternalFlow.qll‎
Lines changed: 76 additions & 4 deletions
@@ -276,6 +276,45 @@ private predicate isClassConstructedFrom(Class c, Class templateClass) {
   not c.isConstructedFrom(_) and c = templateClass
 }
 
+/** Gets the fully templated version of `c`. */
+private Class getFullyTemplatedClassOld(Class c) {
+  not c.isFromUninstantiatedTemplate(_) and
+  isClassConstructedFrom(c, result)
+}
+
+private TemplateClass getOriginalClassTemplate(TemplateClass tc) {
+  result = tc.getOriginalTemplate()
+  or
+  not exists(tc.getOriginalTemplate()) and
+  result = tc
+}
+
+/** Gets the fully templated version of `c`. */
+private Class getFullyTemplatedClassNew(Class c) {
+  not c.isFromUninstantiatedTemplate(_) and
+  exists(Class mid |
+    c.isConstructedFrom(mid)
+    or
+    not c.isConstructedFrom(_) and c = mid
+  |
+    result = getOriginalClassTemplate(mid)
+    or
+    not mid instanceof TemplateClass and mid = result
+  )
+}
+
+/** Gets the fully templated version of `c`. */
+private Class getFullyTemplatedClass(Class c) {
+  // The `Class::getOriginalTemplate` predicate was introduced in CodeQL
+  // version 2.25.6 and the upgrade script leaves the
+  // `class_template_generated_from` extensionals empty if the database
+  // was generated with an older extractor. So we use the old implementation
+  // if the `class_template_generated_from` extensional is empty.
+  if class_template_generated_from(_, _)
+  then result = getFullyTemplatedClassNew(c)
+  else result = getFullyTemplatedClassOld(c)
+}
+
 /**
  * Holds if `f` is an instantiation of a function template `templateFunc`, or
  * holds with `f = templateFunc` if `f` is not an instantiation of any function
@@ -292,7 +331,7 @@ private predicate isFunctionConstructedFrom(Function f, Function templateFunc) {
 }
 
 /** Gets the fully templated version of `f`. */
-Function getFullyTemplatedFunction(Function f) {
+private Function getFullyTemplatedFunctionOld(Function f) {
   not f.isFromUninstantiatedTemplate(_) and
   (
     exists(Class c, Class templateClass, int i |
@@ -306,13 +345,46 @@ Function getFullyTemplatedFunction(Function f) {
   )
 }
 
+private TemplateFunction getOriginalFunctionTemplate(TemplateFunction tf) {
+  result = tf.getOriginalTemplate()
+  or
+  not exists(tf.getOriginalTemplate()) and
+  result = tf
+}
+
+/** Gets the fully templated version of `f`. */
+private Function getFullyTemplatedFunctionNew(Function f) {
+  not f.isFromUninstantiatedTemplate(_) and
+  exists(Function mid |
+    f.isConstructedFrom(mid)
+    or
+    not f.isConstructedFrom(_) and f = mid
+  |
+    result = getOriginalFunctionTemplate(mid)
+    or
+    not mid instanceof TemplateFunction and mid = result
+  )
+}
+
+/** Gets the fully templated version of `f`. */
+Function getFullyTemplatedFunction(Function f) {
+  // The `Function::getOriginalTemplate` predicate was introduced in CodeQL
+  // version 2.25.6 and the upgrade script leaves the
+  // `function_template_generated_from` extensionals empty if the database
+  // was generated with an older extractor. So we use the old implementation
+  // if the `function_template_generated_from` extensional is empty.
+  if function_template_generated_from(_, _)
+  then result = getFullyTemplatedFunctionNew(f)
+  else result = getFullyTemplatedFunctionOld(f)
+}
+
 /** Prefixes `const` to `s` if `t` is const, or returns `s` otherwise. */
 bindingset[s, t]
 private string withConst(string s, Type t) {
   if t.isConst() then result = "const " + s else result = s
 }
 
-/** Prefixes `volatile` to `s` if `t` is const, or returns `s` otherwise. */
+/** Prefixes `volatile` to `s` if `t` is volatile, or returns `s` otherwise. */
 bindingset[s, t]
 private string withVolatile(string s, Type t) {
   if t.isVolatile() then result = "volatile " + s else result = s
@@ -490,7 +562,7 @@ pragma[nomagic]
 private string getTypeNameWithoutClassTemplates(Function f, int n, int remaining) {
   // If there is a declaring type then we start by expanding the function templates
   exists(Class template |
-    isClassConstructedFrom(f.getDeclaringType(), template) and
+    template = getFullyTemplatedClass(f.getDeclaringType()) and
     remaining = getNumberOfSupportedClassTemplateArguments(template) and
     result = getTypeNameWithoutFunctionTemplates(f, n, 0)
   )
@@ -502,7 +574,7 @@ private string getTypeNameWithoutClassTemplates(Function f, int n, int remaining
   or
   exists(string mid, TypeTemplateParameter tp, Class template |
     mid = getTypeNameWithoutClassTemplates(f, n, remaining + 1) and
-    isClassConstructedFrom(f.getDeclaringType(), template) and
+    template = getFullyTemplatedClass(f.getDeclaringType()) and
     tp = getSupportedClassTemplateArgument(template, remaining)
   |
     result = mid.replaceAll(tp.getName(), "class:" + remaining.toString())