C++: test for Class::isStandardLayout()

cpp/ql/test/library-tests/std_layout/test.c

@@ -0,0 +1,5 @@
+
+// Confirm that `Class::isStandardLayout()` holds for a C struct.
+struct PlainOldCStruct {
+  int x;
+};

cpp/ql/test/library-tests/std_layout/test.cpp

@@ -0,0 +1,89 @@
+
+// AStd is a standard layout type
+struct AStd {
+  int x;
+};
+
+// BNonStd is NOT a standard layout type - not all members have the same access
+// control
+class BNonStd {
+  int x;
+public:
+  int y;
+};
+
+// CNonStd is NOT a standard layout type - it has a virtual function
+class CNonStd {
+  virtual void f();
+};
+
+// DNonStd is NOT a standard layout type - it has a virtual base class
+class DNonStd : public virtual AStd {};
+
+// ENonStd is NOT a standard layout type - it has a data member of reference
+// type
+class ENonStd {
+  int& xref;
+};
+
+// FStd is a standard layout type - all data members are standard layout types
+class FStd {
+  AStd a;
+};
+
+// GNonStd is NOT a standard layout type - contains a non-standard-layout member
+class GNonStd {
+  BNonStd b;
+};
+
+// HStd is a standard layout type - its base class is a standard layout type
+struct HStd : AStd {};
+
+// INonStd is NOT a standard layout type - its base class is not a standard
+// layout type
+struct INonStd : BNonStd {};
+
+// JStd is a standard layout type
+struct JStd {
+  static int x;
+};
+
+// KStd is a standard layout type - base class has no non-static data members
+struct KStd : JStd {};
+
+// LStd is a standard layout type - only one base class has non-static data
+// members
+struct LStd : AStd, JStd {};
+
+// MNonStd is NOT a standard layout type - more than one base class with
+// non-static data members
+struct MNonStd : AStd, FStd {};
+
+// Instantiations of NMaybeStd may or may not be standard layout types,
+// depending on the template parameter.
+template<typename T>
+struct NMaybeStd {
+  T x;
+};
+
+// Instantiation NMaybeStd<AStd> is a standard layout type
+NMaybeStd<AStd> nmaybestd_astd;
+
+// Instantiation NMaybeStd<AStd> is a standard layout type
+NMaybeStd<int> nmaybestd_int;
+
+// Instantiation NMaybeStd<BNonStd> is NOT a standard layout type
+NMaybeStd<BNonStd> nmaybestd_bnonstd;
+
+// Instantiations of ONonStd cannot be standard layout types - regardless of the
+// template parameter's type - since not all members have the same access
+// control.
+template<typename T>
+struct ONonStd {
+  T x;
+private:
+  T y;
+};
+
+// Therefore instantiation ONonStd<int> is NOT a standard layout type
+ONonStd<int> ononstd_int;

cpp/ql/test/library-tests/std_layout/test.expected

@@ -0,0 +1,21 @@
+| file://:0:0:0:0 | __va_list_tag | standard layout |
+| test.c:3:8:3:22 | PlainOldCStruct | standard layout |
+| test.cpp:3:8:3:11 | AStd | standard layout |
+| test.cpp:9:7:9:13 | BNonStd | NOT standard layout |
+| test.cpp:16:7:16:13 | CNonStd | NOT standard layout |
+| test.cpp:21:7:21:13 | DNonStd | NOT standard layout |
+| test.cpp:25:7:25:13 | ENonStd | NOT standard layout |
+| test.cpp:30:7:30:10 | FStd | standard layout |
+| test.cpp:35:7:35:13 | GNonStd | NOT standard layout |
+| test.cpp:40:8:40:11 | HStd | standard layout |
+| test.cpp:44:8:44:14 | INonStd | NOT standard layout |
+| test.cpp:47:8:47:11 | JStd | standard layout |
+| test.cpp:52:8:52:11 | KStd | standard layout |
+| test.cpp:56:8:56:11 | LStd | standard layout |
+| test.cpp:60:8:60:14 | MNonStd | NOT standard layout |
+| test.cpp:65:8:65:16 | NMaybeStd<AStd> | standard layout |
+| test.cpp:65:8:65:16 | NMaybeStd<BNonStd> | NOT standard layout |
+| test.cpp:65:8:65:16 | NMaybeStd<T> | NOT standard layout |
+| test.cpp:65:8:65:16 | NMaybeStd<int> | standard layout |
+| test.cpp:82:8:82:14 | ONonStd<T> | NOT standard layout |
+| test.cpp:82:8:82:14 | ONonStd<int> | NOT standard layout |

cpp/ql/test/library-tests/std_layout/test.ql

@@ -0,0 +1,5 @@
+import cpp
+
+from Class c, string s
+where if c.isStandardLayout() then s = "standard layout" else s = "NOT standard layout"
+select c, s