Bug 704127 - Implement MOZ_FINAL as a modifier for classes and virtual member functions. r=cjones

--HG--
extra : rebase_source : d95a3b3e726f810f299314358ba8c5e23557698e

content/base/src/nsTextFragment.h

@@ -43,6 +43,8 @@
 #ifndef nsTextFragment_h___
 #define nsTextFragment_h___
 
+#include "mozilla/Attributes.h"
+
 #include "nsString.h"
 #include "nsReadableUtils.h"
 #include "nsTraceRefcnt.h"
@@ -80,7 +82,7 @@ class nsCString;
  * This class does not have a virtual destructor therefore it is not
  * meant to be subclassed.
  */
-class NS_FINAL_CLASS nsTextFragment {
+class nsTextFragment MOZ_FINAL {
 public:
   static nsresult Init();
   static void Shutdown();

ipc/glue/Shmem.h

@@ -41,6 +41,8 @@
 #ifndef mozilla_ipc_Shmem_h
 #define mozilla_ipc_Shmem_h
 
+#include "mozilla/Attributes.h"
+
 #include "base/basictypes.h"
 #include "base/process.h"
 
@@ -87,7 +89,7 @@
 namespace mozilla {
 namespace ipc {
 
-class NS_FINAL_CLASS Shmem
+class Shmem MOZ_FINAL
 {
   friend struct IPC::ParamTraits<mozilla::ipc::Shmem>;
 

ipc/ipdl/ipdl/builtin.py

@@ -92,6 +92,7 @@ Types = (
 
 
 Includes = (
+    'mozilla/Attributes.h',
     'base/basictypes.h',
     'prtime.h',
     'nscore.h',

ipc/ipdl/ipdl/cxx/cgen.py

@@ -161,9 +161,9 @@ class CxxCodeGen(CodePrinter, Visitor):
         if c.abstract:
             # FIXME/cjones: turn this "on" when we get the analysis
             self.write(' /*NS_ABSTRACT_CLASS*/')
-        if c.final:
-            self.write(' NS_FINAL_CLASS')
         self.write(' '+ c.name)
+        if c.final:
+            self.write(' MOZ_FINAL')
 
         if c.specializes is not None:
             self.write(' <')

js/src/shell/jsworkers.cpp

@@ -40,6 +40,8 @@
 
 #ifdef JS_THREADSAFE
 
+#include "mozilla/Attributes.h"
+
 #include <string.h>
 #include "prthread.h"
 #include "prlock.h"
@@ -351,7 +353,7 @@ class Event
 
 typedef ThreadSafeQueue<Event *> EventQueue;
 
-class MainQueue : public EventQueue, public WorkerParent
+class MainQueue MOZ_FINAL : public EventQueue, public WorkerParent
 {
   private:
     ThreadPool *threadPool;
@@ -430,7 +432,7 @@ class MainQueue : public EventQueue, public WorkerParent
  * We keep a queue of workers with pending events, rather than a queue of
  * events, so that two threads won't try to run a Worker at the same time.
  */
-class WorkerQueue : public ThreadSafeQueue<Worker *>
+class WorkerQueue MOZ_FINAL : public ThreadSafeQueue<Worker *>
 {
   private:
     MainQueue *main;
@@ -588,7 +590,7 @@ class ThreadPool
  * Separately, there is a terminateFlag that other threads can set
  * asynchronously to tell the Worker to terminate.
  */
-class Worker : public WorkerParent
+class Worker MOZ_FINAL : public WorkerParent
 {
   private:
     ThreadPool *threadPool;

layout/generic/nsFrameSelection.h

@@ -37,7 +37,7 @@
 
 #ifndef nsFrameSelection_h___
 #define nsFrameSelection_h___
- 
+
 #include "nsIFrame.h"
 #include "nsIContent.h"
 #include "nsISelectionController.h"
@@ -210,7 +210,7 @@ class nsIScrollableFrame;
  * or they may cause other objects to be deleted.
  */
 
-class NS_FINAL_CLASS nsFrameSelection : public nsISupports {
+class nsFrameSelection : public nsISupports {
 public:
   enum HINT { HINTLEFT = 0, HINTRIGHT = 1};  //end of this line or beginning of next
   /*interfaces for addref and release and queryinterface*/

layout/generic/nsLineBox.h

@@ -43,6 +43,8 @@
 #ifndef nsLineBox_h___
 #define nsLineBox_h___
 
+#include "mozilla/Attributes.h"
+
 #include "nsILineIterator.h"
 #include "nsIFrame.h"
 
@@ -1566,7 +1568,7 @@ nsLineList_const_reverse_iterator::operator=(const nsLineList_const_reverse_iter
 
 //----------------------------------------------------------------------
 
-class NS_FINAL_CLASS nsLineIterator : public nsILineIterator
+class nsLineIterator MOZ_FINAL : public nsILineIterator
 {
 public:
   nsLineIterator();

layout/generic/nsSelection.cpp

@@ -41,6 +41,8 @@
  * Implementation of selection: nsISelection,nsISelectionPrivate and nsFrameSelection
  */
 
+#include "mozilla/Attributes.h"
+
 #include "nsCOMPtr.h"
 #include "nsWeakReference.h"
 #include "nsIFactory.h"
@@ -357,7 +359,7 @@ private:
 };
 
 // Stack-class to turn on/off selection batching for table selection
-class NS_STACK_CLASS NS_FINAL_CLASS nsSelectionBatcher
+class NS_STACK_CLASS nsSelectionBatcher MOZ_FINAL
 {
 private:
   nsCOMPtr<nsISelectionPrivate> mSelection;

layout/style/ImportRule.h

@@ -40,6 +40,8 @@
 #ifndef mozilla_css_ImportRule_h__
 #define mozilla_css_ImportRule_h__
 
+#include "mozilla/Attributes.h"
+
 #include "mozilla/css/Rule.h"
 #include "nsIDOMCSSImportRule.h"
 #include "nsCSSRules.h"
@@ -50,8 +52,8 @@ class nsString;
 namespace mozilla {
 namespace css {
 
-class NS_FINAL_CLASS ImportRule : public Rule,
-                                  public nsIDOMCSSImportRule
+class ImportRule MOZ_FINAL : public Rule,
+                             public nsIDOMCSSImportRule
 {
 public:
   ImportRule(nsMediaList* aMedia, const nsString& aURLSpec);

layout/style/NameSpaceRule.h

@@ -53,8 +53,8 @@ class nsIAtom;
 namespace mozilla {
 namespace css {
 
-class NS_FINAL_CLASS NameSpaceRule : public Rule,
-                                     public nsIDOMCSSRule
+class NameSpaceRule : public Rule,
+                      public nsIDOMCSSRule
 {
 public:
   NameSpaceRule(nsIAtom* aPrefix, const nsString& aURLSpec);

layout/style/StyleRule.h

@@ -318,7 +318,7 @@ protected:
   friend class StyleRule;
 };
 
-class NS_FINAL_CLASS StyleRule : public Rule
+class StyleRule : public Rule
 {
  public:
   StyleRule(nsCSSSelectorList* aSelector,

layout/style/nsCSSRules.cpp

@@ -120,7 +120,7 @@ Rule::GetParentStyleSheet(nsIDOMCSSStyleSheet** aSheet)
 // Style Rule List for group rules
 //
 
-class NS_FINAL_CLASS GroupRuleRuleList : public nsICSSRuleList
+class GroupRuleRuleList : public nsICSSRuleList
 {
 public:
   GroupRuleRuleList(GroupRule *aGroupRule);

layout/style/nsCSSRules.h

@@ -43,6 +43,8 @@
 #ifndef nsCSSRules_h_
 #define nsCSSRules_h_
 
+#include "mozilla/Attributes.h"
+
 #include "mozilla/css/GroupRule.h"
 #include "nsIDOMCSSMediaRule.h"
 #include "nsIDOMCSSMozDocumentRule.h"
@@ -70,8 +72,8 @@ class nsMediaList;
 namespace mozilla {
 namespace css {
 
-class NS_FINAL_CLASS MediaRule : public GroupRule,
-                                 public nsIDOMCSSMediaRule
+class MediaRule : public GroupRule,
+                  public nsIDOMCSSMediaRule
 {
 public:
   MediaRule();
@@ -113,8 +115,8 @@ protected:
   nsRefPtr<nsMediaList> mMedia;
 };
 
-class NS_FINAL_CLASS DocumentRule : public GroupRule,
-                                    public nsIDOMCSSMozDocumentRule
+class DocumentRule : public GroupRule,
+                     public nsIDOMCSSMozDocumentRule
 {
 public:
   DocumentRule();
@@ -212,8 +214,8 @@ private:
   void* operator new(size_t size) CPP_THROW_NEW;
 };
 
-class NS_FINAL_CLASS nsCSSFontFaceRule : public mozilla::css::Rule,
-                                         public nsIDOMCSSFontFaceRule
+class nsCSSFontFaceRule MOZ_FINAL : public mozilla::css::Rule,
+                                    public nsIDOMCSSFontFaceRule
 {
 public:
   nsCSSFontFaceRule() {}
@@ -273,8 +275,8 @@ nsCSSFontFaceStyleDecl::ContainingRule() const
 namespace mozilla {
 namespace css {
 
-class NS_FINAL_CLASS CharsetRule : public Rule,
-                                   public nsIDOMCSSCharsetRule
+class CharsetRule MOZ_FINAL : public Rule,
+                              public nsIDOMCSSCharsetRule
 {
 public:
   CharsetRule(const nsAString& aEncoding);
@@ -313,8 +315,7 @@ private:
 
 class nsCSSKeyframeRule;
 
-class NS_FINAL_CLASS nsCSSKeyframeStyleDeclaration
-                         : public nsDOMCSSDeclaration
+class nsCSSKeyframeStyleDeclaration : public nsDOMCSSDeclaration
 {
 public:
   nsCSSKeyframeStyleDeclaration(nsCSSKeyframeRule *aRule);
@@ -344,8 +345,8 @@ protected:
   nsCSSKeyframeRule *mRule;
 };
 
-class NS_FINAL_CLASS nsCSSKeyframeRule : public mozilla::css::Rule,
-                                         public nsIDOMMozCSSKeyframeRule
+class nsCSSKeyframeRule MOZ_FINAL : public mozilla::css::Rule,
+                                    public nsIDOMMozCSSKeyframeRule
 {
 public:
   // WARNING: Steals the contents of aKeys *and* aDeclaration
@@ -389,8 +390,8 @@ private:
   nsRefPtr<nsCSSKeyframeStyleDeclaration>    mDOMDeclaration;
 };
 
-class NS_FINAL_CLASS nsCSSKeyframesRule : public mozilla::css::GroupRule,
-                                          public nsIDOMMozCSSKeyframesRule
+class nsCSSKeyframesRule : public mozilla::css::GroupRule,
+                           public nsIDOMMozCSSKeyframesRule
 {
 public:
   nsCSSKeyframesRule(const nsSubstring& aName)

layout/style/nsCSSStyleSheet.h

@@ -44,6 +44,8 @@
 #ifndef nsCSSStyleSheet_h_
 #define nsCSSStyleSheet_h_
 
+#include "mozilla/Attributes.h"
+
 #include "nscore.h"
 #include "nsCOMPtr.h"
 #include "nsAutoPtr.h"
@@ -132,9 +134,9 @@ struct ChildSheetListBuilder;
  { 0x84, 0x67, 0x80, 0x3f, 0xb3, 0x2a, 0xf2, 0x0a } }
 
 
-class NS_FINAL_CLASS nsCSSStyleSheet : public nsIStyleSheet,
-                                       public nsIDOMCSSStyleSheet,
-                                       public nsICSSLoaderObserver
+class nsCSSStyleSheet : public nsIStyleSheet,
+                        public nsIDOMCSSStyleSheet,
+                        public nsICSSLoaderObserver
 {
 public:
   nsCSSStyleSheet();
@@ -271,9 +273,8 @@ private:
                   nsIDocument* aDocumentToUse,
                   nsIDOMNode* aOwningNodeToUse);
 
-  // These are not supported and are not implemented! 
-  nsCSSStyleSheet(const nsCSSStyleSheet& aCopy); 
-  nsCSSStyleSheet& operator=(const nsCSSStyleSheet& aCopy); 
+  nsCSSStyleSheet(const nsCSSStyleSheet& aCopy) MOZ_DELETE;
+  nsCSSStyleSheet& operator=(const nsCSSStyleSheet& aCopy) MOZ_DELETE;
 
 protected:
   virtual ~nsCSSStyleSheet();

layout/xul/base/src/tree/src/nsTreeBodyFrame.h

@@ -44,6 +44,8 @@
 #ifndef nsTreeBodyFrame_h
 #define nsTreeBodyFrame_h
 
+#include "mozilla/Attributes.h"
+
 #include "nsLeafBoxFrame.h"
 #include "nsITreeView.h"
 #include "nsICSSPseudoComparator.h"
@@ -77,7 +79,7 @@ struct nsTreeImageCacheEntry
 };
 
 // The actual frame that paints the cells and rows.
-class NS_FINAL_CLASS nsTreeBodyFrame
+class nsTreeBodyFrame MOZ_FINAL
   : public nsLeafBoxFrame
   , public nsICSSPseudoComparator
   , public nsIScrollbarMediator

mfbt/Attributes.h

@@ -64,6 +64,7 @@
 #  if __clang_major__ >= 3
 #    define MOZ_HAVE_CXX11_DELETE
 #    define MOZ_HAVE_CXX11_OVERRIDE
+#    define MOZ_HAVE_CXX11_FINAL         final
 #  elif __clang_major__ == 2
 #    if __clang_minor__ >= 9
 #      define MOZ_HAVE_CXX11_DELETE
@@ -74,6 +75,7 @@
 #    if __GNUC__ > 4
 #      define MOZ_HAVE_CXX11_DELETE
 #      define MOZ_HAVE_CXX11_OVERRIDE
+#      define MOZ_HAVE CXX11_FINAL       final
 #    elif __GNUC__ == 4
 #      if __GNUC_MINOR__ >= 7
 #        define MOZ_HAVE_CXX11_OVERRIDE
@@ -82,10 +84,21 @@
 #        define MOZ_HAVE_CXX11_DELETE
 #      endif
 #    endif
+#  else
+     /* __final is a non-C++11 GCC synonym for 'final', per GCC r176655. */
+#    if __GNUC__ > 4
+#      define MOZ_HAVE_CXX11_FINAL       __final
+#    elif __GNUC__ == 4
+#      if __GNUC_MINOR__ >= 7
+#        define MOZ_HAVE_CXX11_FINAL     __final
+#      endif
+#    endif
 #  endif
 #elif defined(_MSC_VER)
 #  if _MSC_VER >= 1400
 #    define MOZ_HAVE_CXX11_OVERRIDE
+     /* MSVC currently spells "final" as "sealed". */
+#    define MOZ_HAVE_CXX11_FINAL         sealed
 #  endif
 #endif
 
@@ -158,4 +171,73 @@
 #  define MOZ_OVERRIDE          /* no support */
 #endif
 
+/*
+ * MOZ_FINAL indicates that some functionality cannot be overridden through
+ * inheritance.  It can be used to annotate either classes/structs or virtual
+ * member functions.
+ *
+ * To annotate a class/struct with MOZ_FINAL, place MOZ_FINAL immediately after
+ * the name of the class, before the list of classes from which it derives (if
+ * any) and before its opening brace.  MOZ_FINAL must not be used to annotate
+ * unnamed classes or structs.  (With some compilers, and with C++11 proper, the
+ * underlying expansion is ambiguous with specifying a class name.)
+ *
+ *   class Base MOZ_FINAL
+ *   {
+ *     public:
+ *       Base();
+ *       ~Base();
+ *       virtual void f() { }
+ *   };
+ *   // This will be an error in some compilers:
+ *   class Derived : public Base
+ *   {
+ *     public:
+ *       ~Derived() { }
+ *   };
+ *
+ * One particularly common reason to specify MOZ_FINAL upon a class is to tell
+ * the compiler that it's not dangerous for it to have a non-virtual destructor
+ * yet have one or more virtual functions, silencing the warning it might emit
+ * in this case.  Suppose Base above weren't annotated with MOZ_FINAL.  Because
+ * ~Base() is non-virtual, an attempt to delete a Derived* through a Base*
+ * wouldn't call ~Derived(), so any cleanup ~Derived() might do wouldn't happen.
+ * (Formally C++ says behavior is undefined, but compilers will likely just call
+ * ~Base() and not ~Derived().)  Specifying MOZ_FINAL tells the compiler that
+ * it's safe for the destructor to be non-virtual.
+ *
+ * In compilers implementing final controls, it is an error to inherit from a
+ * class annotated with MOZ_FINAL.  In other compilers it serves only as
+ * documentation.
+ *
+ * To annotate a virtual member function with MOZ_FINAL, place MOZ_FINAL
+ * immediately before the ';' terminating the member function's declaration, or
+ * before '= 0;' if the member function is pure.  If the member function is
+ * defined in the class definition, it should appear before the opening brace of
+ * the function body.  (This placement is identical to that for MOZ_OVERRIDE.
+ * If both are used, they should appear in the order 'MOZ_FINAL MOZ_OVERRIDE'
+ * for consistency.)
+ *
+ *   class Base
+ *   {
+ *     public:
+ *       virtual void f() MOZ_FINAL;
+ *   };
+ *   class Derived
+ *   {
+ *     public:
+ *       // This will be an error in some compilers:
+ *       virtual void f();
+ *   };
+ *
+ * In compilers implementing final controls, it is an error for a derived class
+ * to override a method annotated with MOZ_FINAL.  In other compilers it serves
+ * only as documentation.
+ */
+#if defined(MOZ_HAVE_CXX11_FINAL)
+#  define MOZ_FINAL             MOZ_HAVE_CXX11_FINAL
+#else
+#  define MOZ_FINAL             /* no support */
+#endif
+
 #endif  /* mozilla_Attributes_h_ */

xpcom/base/nsConsoleMessage.h

@@ -38,10 +38,12 @@
 #ifndef __nsconsolemessage_h__
 #define __nsconsolemessage_h__
 
+#include "mozilla/Attributes.h"
+
 #include "nsIConsoleMessage.h"
 #include "nsString.h"
 
-class nsConsoleMessage : public nsIConsoleMessage {
+class nsConsoleMessage MOZ_FINAL : public nsIConsoleMessage {
 public:
     nsConsoleMessage();
     nsConsoleMessage(const PRUnichar *message);

xpcom/base/nsErrorService.h

@@ -38,6 +38,8 @@
 #ifndef nsErrorService_h__
 #define nsErrorService_h__
 
+#include "mozilla/Attributes.h"
+
 #include "nsIErrorService.h"
 #include "nsHashtable.h"
 
@@ -54,7 +56,7 @@ protected:
     nsObjectHashtable mHashtable;
 };
 
-class nsErrorService : public nsIErrorService
+class nsErrorService MOZ_FINAL : public nsIErrorService
 {
 public:
     NS_DECL_ISUPPORTS

xpcom/glue/GenericFactory.h

@@ -38,6 +38,8 @@
 #ifndef mozilla_GenericFactory_h
 #define mozilla_GenericFactory_h
 
+#include "mozilla/Attributes.h"
+
 #include "mozilla/Module.h"
 
 namespace mozilla {
@@ -47,7 +49,7 @@ namespace mozilla {
  * This class is intended for use by the component manager and the generic
  * module.
  */
-class GenericFactory : public nsIFactory
+class GenericFactory MOZ_FINAL : public nsIFactory
 {
 public:
   typedef Module::ConstructorProcPtr ConstructorProcPtr;

xpcom/glue/nsArrayEnumerator.cpp

@@ -36,6 +36,8 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+#include "mozilla/Attributes.h"
+
 #include "nsArrayEnumerator.h"
 
 #include "nsIArray.h"
@@ -44,7 +46,7 @@
 #include "nsCOMArray.h"
 #include "nsCOMPtr.h"
 
-class nsSimpleArrayEnumerator : public nsISimpleEnumerator
+class nsSimpleArrayEnumerator MOZ_FINAL : public nsISimpleEnumerator
 {
 public:
     // nsISupports interface
@@ -126,7 +128,7 @@ NS_NewArrayEnumerator(nsISimpleEnumerator* *result,
 // creates a snapshot of the array in question
 // you MUST use NS_NewArrayEnumerator to create this, so that
 // allocation is done correctly
-class nsCOMArrayEnumerator : public nsISimpleEnumerator
+class nsCOMArrayEnumerator MOZ_FINAL : public nsISimpleEnumerator
 {
 public:
     // nsISupports interface

xpcom/glue/nsCOMPtr.h

@@ -53,6 +53,7 @@
                        -- scc
 */
 
+#include "mozilla/Attributes.h"
 
   // Wrapping includes can speed up compiles (see "Large Scale C++ Software Design")
 #ifndef nsDebug_h___
@@ -277,8 +278,7 @@ class nsCOMPtr_helper
 class
   NS_COM_GLUE
   NS_STACK_CLASS
-  NS_FINAL_CLASS
-nsQueryInterface
+nsQueryInterface MOZ_FINAL
   {
     public:
       explicit
@@ -513,9 +513,7 @@ nsCOMPtr_base
 // template <class T> class nsGetterAddRefs;
 
 template <class T>
-class
-  NS_FINAL_CLASS
-nsCOMPtr
+class nsCOMPtr MOZ_FINAL
 #ifdef NSCAP_FEATURE_USE_BASE
     : private nsCOMPtr_base
 #endif

xpcom/glue/nsEnumeratorUtils.cpp

@@ -40,6 +40,8 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+#include "mozilla/Attributes.h"
+
 #include "nsEnumeratorUtils.h"
 
 #include "nsISimpleEnumerator.h"
@@ -124,7 +126,7 @@ NS_NewEmptyEnumerator(nsISimpleEnumerator** aResult)
 
 ////////////////////////////////////////////////////////////////////////////////
 
-class nsSingletonEnumerator : public nsISimpleEnumerator
+class nsSingletonEnumerator MOZ_FINAL : public nsISimpleEnumerator
 {
 public:
     NS_DECL_ISUPPORTS

xpcom/glue/nsWeakReference.cpp

@@ -40,10 +40,12 @@
 
 // nsWeakReference.cpp
 
+#include "mozilla/Attributes.h"
+
 #include "nsWeakReference.h"
 #include "nsCOMPtr.h"
 
-class nsWeakReference : public nsIWeakReference
+class nsWeakReference MOZ_FINAL : public nsIWeakReference
   {
     public:
     // nsISupports...