C++: Allow querying virtual, override, and final declaration specifiers.

Author: sashabu

cpp/change-notes/2021-07-29-virtual-function-declaration-specifiers.md

@@ -0,0 +1,2 @@
+lgtm,codescanning
+* Virtual function specifiers are now accessible via the new predicates on `Function` (`.isDeclaredVirtual`, `.isOverride`, and `.isFinal`).

cpp/ql/src/semmle/code/cpp/Function.qll

@@ -82,9 +82,23 @@ class Function extends Declaration, ControlFlowNode, AccessHolder, @function {
   /** Holds if this function is inline. */
   predicate isInline() { this.hasSpecifier("inline") }
 
-  /** Holds if this function is virtual. */
+  /**
+   * Holds if this function is virtual.
+   *
+   * Unlike `isDeclaredVirtual()`, `isVirtual()` holds even if the function
+   * is not explicitly declared with the `virtual` specifier.
+   */
   predicate isVirtual() { this.hasSpecifier("virtual") }
 
+  /** Holds if this function is declared with the `virtual` specifier. */
+  predicate isDeclaredVirtual() { this.hasSpecifier("declared_virtual") }
+
+  /** Holds if this function is declared with the `override` specifier. */
+  predicate isOverride() { this.hasSpecifier("override") }
+
+  /** Holds if this function is declared with the `final` specifier. */
+  predicate isFinal() { this.hasSpecifier("final") }
+
   /**
    * Holds if this function is deleted.
    * This may be because it was explicitly deleted with an `= delete`

cpp/ql/test/library-tests/clang_ms/element.expected

@@ -79,6 +79,7 @@
 | file://:0:0:0:0 | declaration of 1st parameter |
 | file://:0:0:0:0 | declared_constexpr |
 | file://:0:0:0:0 | declared_constinit |
+| file://:0:0:0:0 | declared_virtual |
 | file://:0:0:0:0 | decltype(nullptr) |
 | file://:0:0:0:0 | definition of fp_offset |
 | file://:0:0:0:0 | definition of gp_offset |
@@ -91,6 +92,7 @@
 | file://:0:0:0:0 | explicit |
 | file://:0:0:0:0 | extern |
 | file://:0:0:0:0 | far |
+| file://:0:0:0:0 | final |
 | file://:0:0:0:0 | float |
 | file://:0:0:0:0 | forceinline |
 | file://:0:0:0:0 | fp_offset |

cpp/ql/test/library-tests/conditions/elements.expected

@@ -49,6 +49,7 @@
 | file://:0:0:0:0 | const __va_list_tag & |
 | file://:0:0:0:0 | declared_constexpr |
 | file://:0:0:0:0 | declared_constinit |
+| file://:0:0:0:0 | declared_virtual |
 | file://:0:0:0:0 | decltype(nullptr) |
 | file://:0:0:0:0 | definition of <error> |
 | file://:0:0:0:0 | definition of fp_offset |
@@ -62,6 +63,7 @@
 | file://:0:0:0:0 | explicit |
 | file://:0:0:0:0 | extern |
 | file://:0:0:0:0 | far |
+| file://:0:0:0:0 | final |
 | file://:0:0:0:0 | float |
 | file://:0:0:0:0 | forceinline |
 | file://:0:0:0:0 | fp_offset |

cpp/ql/test/library-tests/specifiers2/specifiers2.expected

@@ -43,10 +43,12 @@
 | Function | specifiers2pp.cpp:10:18:10:24 | MyClass | MyClass | public |
 | Function | specifiers2pp.cpp:12:14:12:22 | publicFun | publicFun | inline |
 | Function | specifiers2pp.cpp:12:14:12:22 | publicFun | publicFun | public |
+| Function | specifiers2pp.cpp:13:21:13:26 | getInt | getInt | declared_virtual |
 | Function | specifiers2pp.cpp:13:21:13:26 | getInt | getInt | extern |
 | Function | specifiers2pp.cpp:13:21:13:26 | getInt | getInt | public |
 | Function | specifiers2pp.cpp:13:21:13:26 | getInt | getInt | pure |
 | Function | specifiers2pp.cpp:13:21:13:26 | getInt | getInt | virtual |
+| Function | specifiers2pp.cpp:14:21:14:21 | f | f | declared_virtual |
 | Function | specifiers2pp.cpp:14:21:14:21 | f | f | extern |
 | Function | specifiers2pp.cpp:14:21:14:21 | f | f | public |
 | Function | specifiers2pp.cpp:14:21:14:21 | f | f | virtual |
@@ -71,6 +73,7 @@
 | Function | specifiers2pp.cpp:24:7:24:7 | operator= | operator= | inline |
 | Function | specifiers2pp.cpp:24:7:24:7 | operator= | operator= | public |
 | Function | specifiers2pp.cpp:24:7:24:7 | operator= | operator= | public |
+| Function | specifiers2pp.cpp:26:21:26:21 | f | f | declared_virtual |
 | Function | specifiers2pp.cpp:26:21:26:21 | f | f | extern |
 | Function | specifiers2pp.cpp:26:21:26:21 | f | f | override |
 | Function | specifiers2pp.cpp:26:21:26:21 | f | f | public |

cpp/ql/test/library-tests/templates/instantiations_functions/elements.expected

@@ -109,6 +109,7 @@
 | file://:0:0:0:0 | declaration of 1st parameter |
 | file://:0:0:0:0 | declared_constexpr |
 | file://:0:0:0:0 | declared_constinit |
+| file://:0:0:0:0 | declared_virtual |
 | file://:0:0:0:0 | decltype(nullptr) |
 | file://:0:0:0:0 | definition of fp_offset |
 | file://:0:0:0:0 | definition of gp_offset |
@@ -121,6 +122,7 @@
 | file://:0:0:0:0 | explicit |
 | file://:0:0:0:0 | extern |
 | file://:0:0:0:0 | far |
+| file://:0:0:0:0 | final |
 | file://:0:0:0:0 | float |
 | file://:0:0:0:0 | forceinline |
 | file://:0:0:0:0 | fp_offset |

cpp/ql/test/library-tests/unnamed/elements.expected

@@ -41,6 +41,7 @@
 | file://:0:0:0:0 | const | Other |
 | file://:0:0:0:0 | declared_constexpr | Other |
 | file://:0:0:0:0 | declared_constinit | Other |
+| file://:0:0:0:0 | declared_virtual | Other |
 | file://:0:0:0:0 | decltype(nullptr) | Other |
 | file://:0:0:0:0 | definition of fp_offset | Other |
 | file://:0:0:0:0 | definition of gp_offset | Other |
@@ -53,6 +54,7 @@
 | file://:0:0:0:0 | explicit | Other |
 | file://:0:0:0:0 | extern | Other |
 | file://:0:0:0:0 | far | Other |
+| file://:0:0:0:0 | final | Other |
 | file://:0:0:0:0 | float | Other |
 | file://:0:0:0:0 | forceinline | Other |
 | file://:0:0:0:0 | fp_offset | Other |