C++: Introduce usertypes for structs and unions

cpp/ql/lib/semmle/code/cpp/Class.qll

@@ -869,7 +869,7 @@ class AbstractClass extends Class {
  * `FullClassTemplateSpecialization`.
  */
 class TemplateClass extends Class {
-  TemplateClass() { usertypes(underlyingElement(this), _, 6) }
+  TemplateClass() { usertypes(underlyingElement(this), _, [15, 16, 17]) }
 
   /**
    * Gets a class instantiated from this template.

cpp/ql/lib/semmle/code/cpp/Struct.qll

@@ -20,7 +20,7 @@ import semmle.code.cpp.Class
  * ```
  */
 class Struct extends Class {
-  Struct() { usertypes(underlyingElement(this), _, 1) or usertypes(underlyingElement(this), _, 3) }
+  Struct() { usertypes(underlyingElement(this), _, [1, 3, 15, 17]) }
 
   override string getAPrimaryQlClass() { result = "Struct" }
 

cpp/ql/lib/semmle/code/cpp/TemplateParameter.qll

@@ -52,9 +52,7 @@ deprecated class TemplateParameter = TypeTemplateParameter;
  * ```
  */
 class TypeTemplateParameter extends UserType, TemplateParameterImpl {
-  TypeTemplateParameter() {
-    usertypes(underlyingElement(this), _, 7) or usertypes(underlyingElement(this), _, 8)
-  }
+  TypeTemplateParameter() { usertypes(underlyingElement(this), _, [7, 8]) }
 
   override string getAPrimaryQlClass() { result = "TypeTemplateParameter" }
 

cpp/ql/lib/semmle/code/cpp/Type.qll

@@ -406,10 +406,7 @@ class IntegralOrEnumType extends Type {
     isIntegralType(underlyingElement(this), _)
     or
     // Enum type
-    (
-      usertypes(underlyingElement(this), _, 4) or
-      usertypes(underlyingElement(this), _, 13)
-    )
+    usertypes(underlyingElement(this), _, [4, 13])
   }
 }
 

cpp/ql/lib/semmle/code/cpp/TypedefType.qll

@@ -13,10 +13,7 @@ private import semmle.code.cpp.internal.ResolveClass
  * ```
  */
 class TypedefType extends UserType {
-  TypedefType() {
-    usertypes(underlyingElement(this), _, 5) or
-    usertypes(underlyingElement(this), _, 14)
-  }
+  TypedefType() { usertypes(underlyingElement(this), _, [5, 14]) }
 
   /**
    * Gets the base type of this typedef type.

cpp/ql/lib/semmle/code/cpp/Union.qll

@@ -15,7 +15,7 @@ import semmle.code.cpp.Struct
  * ```
  */
 class Union extends Struct {
-  Union() { usertypes(underlyingElement(this), _, 3) }
+  Union() { usertypes(underlyingElement(this), _, [3, 17]) }
 
   override string getAPrimaryQlClass() { result = "Union" }
 

cpp/ql/lib/semmle/code/cpp/internal/QualifiedName.qll

@@ -227,11 +227,11 @@ class ProxyClass extends UserType {
 }
 
 class TypeTemplateParameter extends UserType {
-  TypeTemplateParameter() { usertypes(this, _, 7) or usertypes(this, _, 8) }
+  TypeTemplateParameter() { usertypes(this, _, [7, 8]) }
 }
 
 class TemplateClass extends UserType {
-  TemplateClass() { usertypes(this, _, 6) }
+  TemplateClass() { usertypes(this, _, [15, 16, 17]) }
 
   UserType getAnInstantiation() {
     class_instantiation(result, this) and

cpp/ql/lib/semmle/code/cpp/internal/ResolveClass.qll

@@ -114,15 +114,7 @@ private module Cached {
    * Holds if `t` is a struct, class, union, or template.
    */
   cached
-  predicate isClass(@usertype t) {
-    usertypes(t, _, 1) or
-    usertypes(t, _, 2) or
-    usertypes(t, _, 3) or
-    usertypes(t, _, 6) or
-    usertypes(t, _, 10) or
-    usertypes(t, _, 11) or
-    usertypes(t, _, 12)
-  }
+  predicate isClass(@usertype t) { usertypes(t, _, [1, 2, 3, 15, 16, 17]) }
 
   cached
   predicate isType(@type t) {

cpp/ql/lib/semmlecode.cpp.dbscheme

@@ -771,12 +771,13 @@ decltypes(
 
 /*
 case @usertype.kind of
-   1 = @struct
+|  0 = @unknown_usertype
+|  1 = @struct
 |  2 = @class
 |  3 = @union
 |  4 = @enum
 |  5 = @typedef                       // classic C: typedef typedef type name
-|  6 = @template
+// ... 6 = @template deprecated
 |  7 = @template_parameter
 |  8 = @template_template_parameter
 |  9 = @proxy_class                   // a proxy class associated with a template parameter
@@ -785,6 +786,9 @@ case @usertype.kind of
 // ... 12 objc_category deprecated
 | 13 = @scoped_enum
 | 14 = @using_alias                  // a using name = type style typedef
+| 15 = @template_struct
+| 16 = @template_class
+| 17 = @template_union
 ;
 */
 

cpp/ql/src/Architecture/Refactoring Opportunities/ClassesWithManyFields.ql

@@ -21,7 +21,7 @@ string kindstr(Class c) {
     or
     kind = 2 and result = "Class"
     or
-    kind = 6 and result = "Template class"
+    kind = [15, 16] and result = "Template class"
   )
 }