C++: Placement-new tests for MemoryNeverFreed.ql

Author: jbj

cpp/ql/test/query-tests/Critical/MemoryFreed/MemoryNeverFreed.expected

@@ -8,3 +8,7 @@
 | test.cpp:42:18:42:23 | call to malloc | This memory is never freed |
 | test.cpp:73:18:73:23 | call to malloc | This memory is never freed |
 | test.cpp:89:18:89:23 | call to malloc | This memory is never freed |
+| test.cpp:150:3:150:21 | new | This memory is never freed |
+| test.cpp:153:3:153:17 | new[] | This memory is never freed |
+| test.cpp:156:3:156:26 | new | This memory is never freed |
+| test.cpp:157:3:157:26 | new[] | This memory is never freed |

cpp/ql/test/query-tests/Critical/MemoryFreed/test.cpp

@@ -130,3 +130,29 @@ int main()
 
 	return 0;
 }
+
+// --- placement new ---
+
+namespace std {
+  typedef unsigned long size_t;
+  struct nothrow_t {};
+  extern const nothrow_t nothrow;
+}
+
+void* operator new  (std::size_t size, void* ptr) noexcept;
+void* operator new[](std::size_t size, void* ptr) noexcept;
+void* operator new(std::size_t size, const std::nothrow_t&) noexcept;
+void* operator new[](std::size_t size, const std::nothrow_t&) noexcept;
+
+int overloadedNew() {
+  char buf[sizeof(int)];
+
+  new(&buf[0]) int(5); // GOOD [FALSE POSITIVE]
+  int five = *(int*)buf;
+
+  new(buf) int[1]; // GOOD [FALSE POSITIVE]
+  *(int*)buf = 4;
+
+  new(std::nothrow) int(3); // BAD
+  new(std::nothrow) int[2]; // BAD
+}