Issue #2342: Use [[nodiscard]] in /uriloader /widget

Also a few misc low-volume places.

18 files changed, 59 insertions, 65 deletions

diff --git a/security/manager/ssl/nsNSSComponent.h b/security/manager/ssl/nsNSSComponent.h
index e510dd10f3..f595aa5c50 100644
--- a/security/manager/ssl/nsNSSComponent.h
+++ b/security/manager/ssl/nsNSSComponent.h
@@ -30,7 +30,7 @@ class SmartCardThreadList;
 
 namespace mozilla { namespace psm {
 
-MOZ_MUST_USE
+[[nodiscard]]
   ::already_AddRefed<mozilla::psm::SharedCertVerifier>
   GetDefaultCertVerifier();
 
diff --git a/toolkit/components/commandlines/nsCommandLine.cpp b/toolkit/components/commandlines/nsCommandLine.cpp
index 280b1d24a6..d78cdd23a8 100644
--- a/toolkit/components/commandlines/nsCommandLine.cpp
+++ b/toolkit/components/commandlines/nsCommandLine.cpp
@@ -65,7 +65,7 @@ protected:
 					void *aClosure);
 
   void appendArg(const char* arg);
-  MOZ_MUST_USE nsresult resolveShortcutURL(nsIFile* aFile, nsACString& outURL);
+  [[nodiscard]] nsresult resolveShortcutURL(nsIFile* aFile, nsACString& outURL);
   nsresult EnumerateHandlers(EnumerateHandlersCallback aCallback, void *aClosure);
   nsresult EnumerateValidators(EnumerateValidatorsCallback aCallback, void *aClosure);
 
diff --git a/uriloader/base/nsDocLoader.h b/uriloader/base/nsDocLoader.h
index b469b8e079..1c50df24b1 100644
--- a/uriloader/base/nsDocLoader.h
+++ b/uriloader/base/nsDocLoader.h
@@ -58,7 +58,7 @@ public:
 
     nsDocLoader();
 
-    virtual MOZ_MUST_USE nsresult Init();
+    [[nodiscard]] virtual nsresult Init();
 
     static already_AddRefed<nsDocLoader> GetAsDocLoader(nsISupports* aSupports);
     // Needed to deal with ambiguous inheritance from nsISupports...
@@ -67,7 +67,7 @@ public:
     }
 
     // Add aDocLoader as a child to the docloader service.
-    static MOZ_MUST_USE nsresult AddDocLoaderAsChildOfRoot(nsDocLoader* aDocLoader);
+    [[nodiscard]] static nsresult AddDocLoaderAsChildOfRoot(nsDocLoader* aDocLoader);
 
     NS_DECL_ISUPPORTS
     NS_DECL_NSIDOCUMENTLOADER
@@ -89,10 +89,10 @@ public:
 
     // Remove aChild from our childlist.  This nulls out the child's mParent
     // pointer.
-    MOZ_MUST_USE nsresult RemoveChildLoader(nsDocLoader *aChild);
+    [[nodiscard]] nsresult RemoveChildLoader(nsDocLoader *aChild);
     // Add aChild to our child list.  This will set aChild's mParent pointer to
     // |this|.
-    MOZ_MUST_USE nsresult AddChildLoader(nsDocLoader* aChild);
+    [[nodiscard]] nsresult AddChildLoader(nsDocLoader* aChild);
     nsDocLoader* GetParent() const { return mParent; }
 
     struct nsListenerInfo {
@@ -114,7 +114,7 @@ public:
 protected:
     virtual ~nsDocLoader();
 
-    virtual MOZ_MUST_USE nsresult SetDocLoaderParent(nsDocLoader * aLoader);
+    [[nodiscard]] virtual nsresult SetDocLoaderParent(nsDocLoader * aLoader);
 
     bool IsBusy();
 
@@ -166,7 +166,7 @@ protected:
                               nsIURI *aUri,
                               uint32_t aFlags);
 
-    MOZ_MUST_USE bool RefreshAttempted(nsIWebProgress* aWebProgress,
+    [[nodiscard]] bool RefreshAttempted(nsIWebProgress* aWebProgress,
                             nsIURI *aURI,
                             int32_t aDelay,
                             bool aSameURI);
@@ -189,7 +189,7 @@ protected:
 
     // Inform a parent docloader that aChild is about to call its onload
     // handler.
-    MOZ_MUST_USE bool ChildEnteringOnload(nsIDocumentLoader* aChild) {
+    [[nodiscard]] bool ChildEnteringOnload(nsIDocumentLoader* aChild) {
         // It's ok if we're already in the list -- we'll just be in there twice
         // and then the RemoveObject calls from ChildDoneWithOnload will remove
         // us.
diff --git a/uriloader/base/nsURILoader.h b/uriloader/base/nsURILoader.h
index 2c5648dbae..3e92eec452 100644
--- a/uriloader/base/nsURILoader.h
+++ b/uriloader/base/nsURILoader.h
@@ -35,11 +35,11 @@ protected:
    * Equivalent to nsIURILoader::openChannel, but allows specifying whether the
    * channel is opened already.
    */
-  MOZ_MUST_USE nsresult OpenChannel(nsIChannel* channel,
-                                    uint32_t aFlags,
-                                    nsIInterfaceRequestor* aWindowContext,
-                                    bool aChannelOpen,
-                                    nsIStreamListener** aListener);
+  [[nodiscard]] nsresult OpenChannel(nsIChannel* channel,
+                                     uint32_t aFlags,
+                                     nsIInterfaceRequestor* aWindowContext,
+                                     bool aChannelOpen,
+                                     nsIStreamListener** aListener);
 
   /**
    * we shouldn't need to have an owning ref count on registered
diff --git a/uriloader/exthandler/ContentHandlerService.h b/uriloader/exthandler/ContentHandlerService.h
index e39e89bc90..1781bbe69c 100644
--- a/uriloader/exthandler/ContentHandlerService.h
+++ b/uriloader/exthandler/ContentHandlerService.h
@@ -21,7 +21,7 @@ public:
   NS_DECL_NSIHANDLERSERVICE
 
   ContentHandlerService();
-  MOZ_MUST_USE nsresult Init();
+  [[nodiscard]] nsresult Init();
   static void nsIHandlerInfoToHandlerInfo(nsIHandlerInfo* aInfo, HandlerInfo* aHandlerInfo);
 
 private:
diff --git a/uriloader/exthandler/ExternalHelperAppChild.h b/uriloader/exthandler/ExternalHelperAppChild.h
index 0e3b09848c..ee5057857e 100644
--- a/uriloader/exthandler/ExternalHelperAppChild.h
+++ b/uriloader/exthandler/ExternalHelperAppChild.h
@@ -32,7 +32,7 @@ public:
     virtual bool RecvCancel(const nsresult& aStatus) override;
 private:
     virtual ~ExternalHelperAppChild();
-    MOZ_MUST_USE nsresult DivertToParent(nsIDivertableChannel *divertable, nsIRequest *request);
+    [[nodiscard]] nsresult DivertToParent(nsIDivertableChannel *divertable, nsIRequest *request);
 
     RefPtr<nsExternalAppHandler> mHandler;
     nsresult mStatus;
diff --git a/uriloader/exthandler/mac/nsDecodeAppleFile.h b/uriloader/exthandler/mac/nsDecodeAppleFile.h
index cea2d701ec..8433b533af 100644
--- a/uriloader/exthandler/mac/nsDecodeAppleFile.h
+++ b/uriloader/exthandler/mac/nsDecodeAppleFile.h
@@ -83,7 +83,7 @@ public:
   nsDecodeAppleFile();
   virtual ~nsDecodeAppleFile();
   
-  MOZ_MUST_USE nsresult Initialize(nsIOutputStream *output, nsIFile *file);
+  [[nodiscard]] nsresult Initialize(nsIOutputStream *output, nsIFile *file);
   
 private:
   #define MAX_BUFFERSIZE    1024
diff --git a/uriloader/exthandler/mac/nsMIMEInfoMac.h b/uriloader/exthandler/mac/nsMIMEInfoMac.h
index 298357f757..d301234c87 100644
--- a/uriloader/exthandler/mac/nsMIMEInfoMac.h
+++ b/uriloader/exthandler/mac/nsMIMEInfoMac.h
@@ -16,15 +16,15 @@ class nsMIMEInfoMac : public nsMIMEInfoImpl {
 
     NS_IMETHOD LaunchWithFile(nsIFile* aFile);
   protected:
-    virtual MOZ_MUST_USE nsresult LoadUriInternal(nsIURI *aURI);
+    [[nodiscard]] virtual nsresult LoadUriInternal(nsIURI *aURI);
 #ifdef DEBUG
-    virtual MOZ_MUST_USE nsresult LaunchDefaultWithFile(nsIFile* aFile) {
+    [[nodiscard]] virtual nsresult LaunchDefaultWithFile(nsIFile* aFile) {
       NS_NOTREACHED("do not call this method, use LaunchWithFile");
       return NS_ERROR_UNEXPECTED;
     }
 #endif
-    static MOZ_MUST_USE nsresult OpenApplicationWithURI(nsIFile *aApplication,
-                                                        const nsCString& aURI);
+    [[nodiscard]] static nsresult OpenApplicationWithURI(nsIFile *aApplication,
+                                                         const nsCString& aURI);
                                                        
     NS_IMETHOD GetDefaultDescription(nsAString& aDefaultDescription);
     
diff --git a/uriloader/exthandler/mac/nsOSHelperAppService.h b/uriloader/exthandler/mac/nsOSHelperAppService.h
index 7371e1f42d..05e71d4b1b 100644
--- a/uriloader/exthandler/mac/nsOSHelperAppService.h
+++ b/uriloader/exthandler/mac/nsOSHelperAppService.h
@@ -36,10 +36,10 @@ public:
   // platformAppPath --> a platform specific path to an application that we got out of the 
   //                     rdf data source. This can be a mac file spec, a unix path or a windows path depending on the platform
   // aFile --> an nsIFile representation of that platform application path.
-  virtual MOZ_MUST_USE nsresult GetFileTokenForPath(const char16_t * platformAppPath, nsIFile ** aFile);
+  [[nodiscard]] virtual nsresult GetFileTokenForPath(const char16_t * platformAppPath, nsIFile ** aFile);
 
-  MOZ_MUST_USE nsresult OSProtocolHandlerExists(const char * aScheme,
-                                                bool * aHandlerExists);
+  [[nodiscard]] nsresult OSProtocolHandlerExists(const char * aScheme,
+                                                 bool * aHandlerExists);
 
 private:
   uint32_t mPermissions;
diff --git a/uriloader/exthandler/nsExternalHelperAppService.h b/uriloader/exthandler/nsExternalHelperAppService.h
index 13dcbb7122..7956b70b2d 100644
--- a/uriloader/exthandler/nsExternalHelperAppService.h
+++ b/uriloader/exthandler/nsExternalHelperAppService.h
@@ -67,7 +67,7 @@ public:
    * Initializes internal state. Will be called automatically when
    * this service is first instantiated.
    */
-  MOZ_MUST_USE nsresult Init();
+  [[nodiscard]] nsresult Init();
  
   /**
    * Given a mimetype and an extension, looks up a mime info from the OS.
diff --git a/widget/PluginWidgetProxy.h b/widget/PluginWidgetProxy.h
index 3fb86a5162..e16554967f 100644
--- a/widget/PluginWidgetProxy.h
+++ b/widget/PluginWidgetProxy.h
@@ -35,11 +35,10 @@ public:
 
   // nsIWidget
   using PuppetWidget::Create; // for Create signature not overridden here
-  virtual MOZ_MUST_USE nsresult Create(nsIWidget* aParent,
-                                       nsNativeWidget aNativeParent,
-                                       const LayoutDeviceIntRect& aRect,
-                                       nsWidgetInitData* aInitData = nullptr)
-                                       override;
+  [[nodiscard]] virtual nsresult Create(nsIWidget* aParent,
+                                        nsNativeWidget aNativeParent,
+                                        const LayoutDeviceIntRect& aRect,
+                                        nsWidgetInitData* aInitData = nullptr) override;
   virtual void Destroy() override;
   NS_IMETHOD SetFocus(bool aRaise = false) override;
   NS_IMETHOD SetParent(nsIWidget* aNewParent) override;
diff --git a/widget/cocoa/nsChildView.h b/widget/cocoa/nsChildView.h
index 7b998a6c5c..3ec93f1875 100644
--- a/widget/cocoa/nsChildView.h
+++ b/widget/cocoa/nsChildView.h
@@ -303,11 +303,10 @@ public:
   nsChildView();
 
   // nsIWidget interface
-  virtual MOZ_MUST_USE nsresult Create(nsIWidget* aParent,
-                                       nsNativeWidget aNativeParent,
-                                       const LayoutDeviceIntRect& aRect,
-                                       nsWidgetInitData* aInitData = nullptr)
-                                       override;
+  [[nodiscard]] virtual nsresult Create(nsIWidget* aParent,
+                                        nsNativeWidget aNativeParent,
+                                        const LayoutDeviceIntRect& aRect,
+                                        nsWidgetInitData* aInitData = nullptr) override;
 
   virtual void            Destroy() override;
 
diff --git a/widget/cocoa/nsCocoaWindow.h b/widget/cocoa/nsCocoaWindow.h
index 1913696b8c..43f8668e84 100644
--- a/widget/cocoa/nsCocoaWindow.h
+++ b/widget/cocoa/nsCocoaWindow.h
@@ -223,17 +223,15 @@ public:
     NS_DECL_ISUPPORTS_INHERITED
     NS_DECL_NSPIWIDGETCOCOA
 
-    virtual MOZ_MUST_USE nsresult Create(nsIWidget* aParent,
-                                         nsNativeWidget aNativeParent,
-                                         const DesktopIntRect& aRect,
-                                         nsWidgetInitData* aInitData = nullptr)
-                                         override;
-
-    virtual MOZ_MUST_USE nsresult Create(nsIWidget* aParent,
-                                         nsNativeWidget aNativeParent,
-                                         const LayoutDeviceIntRect& aRect,
-                                         nsWidgetInitData* aInitData = nullptr)
-                                         override;
+    [[nodiscard]] virtual nsresult Create(nsIWidget* aParent,
+                                          nsNativeWidget aNativeParent,
+                                          const DesktopIntRect& aRect,
+                                          nsWidgetInitData* aInitData = nullptr) override;
+
+    [[nodiscard]] virtual nsresult Create(nsIWidget* aParent,
+                                          nsNativeWidget aNativeParent,
+                                          const LayoutDeviceIntRect& aRect,
+                                          nsWidgetInitData* aInitData = nullptr) override;
 
     virtual void            Destroy() override;
 
diff --git a/widget/gtk/nsWindow.h b/widget/gtk/nsWindow.h
index f76f72d71b..1772e11926 100644
--- a/widget/gtk/nsWindow.h
+++ b/widget/gtk/nsWindow.h
@@ -94,10 +94,10 @@ public:
 
     // nsIWidget
     using nsBaseWidget::Create; // for Create signature not overridden here
-    virtual MOZ_MUST_USE nsresult Create(nsIWidget* aParent,
-                                         nsNativeWidget aNativeParent,
-                                         const LayoutDeviceIntRect& aRect,
-                                         nsWidgetInitData* aInitData) override;
+    [[nodiscard]] virtual nsresult Create(nsIWidget* aParent,
+                                          nsNativeWidget aNativeParent,
+                                          const LayoutDeviceIntRect& aRect,
+                                          nsWidgetInitData* aInitData) override;
     virtual void       Destroy() override;
     virtual nsIWidget *GetParent() override;
     virtual float      GetDPI() override;
diff --git a/widget/nsBaseWidget.h b/widget/nsBaseWidget.h
index ab29fcd0ff..cc38b14b86 100644
--- a/widget/nsBaseWidget.h
+++ b/widget/nsBaseWidget.h
@@ -239,7 +239,7 @@ public:
   virtual LayoutDeviceIntRect GetBounds() override;
   virtual LayoutDeviceIntRect GetClientBounds() override;
   virtual LayoutDeviceIntRect GetScreenBounds() override;
-  virtual MOZ_MUST_USE nsresult GetRestoredBounds(LayoutDeviceIntRect& aRect) override;
+  [[nodiscard]] virtual   nsresult GetRestoredBounds(LayoutDeviceIntRect& aRect) override;
   NS_IMETHOD              SetNonClientMargins(LayoutDeviceIntMargin& aMargins) override;
   virtual LayoutDeviceIntPoint GetClientOffset() override;
   virtual void            EnableDragDrop(bool aEnable) override {};
diff --git a/widget/nsIWidget.h b/widget/nsIWidget.h
index fe21b67275..825db6f0cf 100644
--- a/widget/nsIWidget.h
+++ b/widget/nsIWidget.h
@@ -417,7 +417,7 @@ class nsIWidget : public nsISupports
      * @param     aInitData     data that is used for widget initialization
      *
      */
-    virtual MOZ_MUST_USE nsresult
+    [[nodiscard]] virtual nsresult
     Create(nsIWidget* aParent,
            nsNativeWidget aNativeParent,
            const LayoutDeviceIntRect& aRect,
@@ -431,7 +431,7 @@ class nsIWidget : public nsISupports
      * mapping is not straightforward or the native platform needs to use the
      * desktop pixel values directly.
      */
-    virtual MOZ_MUST_USE nsresult
+    [[nodiscard]] virtual nsresult
     Create(nsIWidget* aParent,
            nsNativeWidget aNativeParent,
            const DesktopIntRect& aRect,
@@ -890,7 +890,7 @@ class nsIWidget : public nsISupports
      * @param aRect   On return it holds the  x, y, width and height of
      *                this widget.
      */
-    virtual MOZ_MUST_USE nsresult
+    [[nodiscard]] virtual nsresult
     GetRestoredBounds(LayoutDeviceIntRect& aRect) = 0;
 
     /**
diff --git a/widget/uikit/nsWindow.h b/widget/uikit/nsWindow.h
index cb18c09069..9a69113312 100644
--- a/widget/uikit/nsWindow.h
+++ b/widget/uikit/nsWindow.h
@@ -29,11 +29,10 @@ public:
     // nsIWidget
     //
 
-    virtual MOZ_MUST_USE nsresult Create(nsIWidget* aParent,
-                                         nsNativeWidget aNativeParent,
-                                         const LayoutDeviceIntRect& aRect,
-                                         nsWidgetInitData* aInitData = nullptr)
-                                         override;
+    [[nodiscard]] virtual nsresult Create(nsIWidget* aParent,
+                                          nsNativeWidget aNativeParent,
+                                          const LayoutDeviceIntRect& aRect,
+                                          nsWidgetInitData* aInitData = nullptr) override;
     virtual void Destroy() override;
     NS_IMETHOD Show(bool aState) override;
     NS_IMETHOD              Enable(bool aState) override {
diff --git a/widget/windows/nsWindow.h b/widget/windows/nsWindow.h
index ec4a1f0192..4c6c7cb80d 100644
--- a/widget/windows/nsWindow.h
+++ b/widget/windows/nsWindow.h
@@ -98,11 +98,10 @@ public:
 
   // nsIWidget interface
   using nsWindowBase::Create; // for Create signature not overridden here
-  virtual MOZ_MUST_USE nsresult Create(nsIWidget* aParent,
-                                       nsNativeWidget aNativeParent,
-                                       const LayoutDeviceIntRect& aRect,
-                                       nsWidgetInitData* aInitData = nullptr)
-                                       override;
+  [[nodiscard]] virtual nsresult Create(nsIWidget* aParent,
+                                        nsNativeWidget aNativeParent,
+                                        const LayoutDeviceIntRect& aRect,
+                                        nsWidgetInitData* aInitData = nullptr) override;
   virtual void            Destroy() override;
   NS_IMETHOD              SetParent(nsIWidget *aNewParent) override;
   virtual nsIWidget*      GetParent(void) override;
@@ -136,7 +135,7 @@ public:
   NS_IMETHOD              SetFocus(bool aRaise) override;
   virtual LayoutDeviceIntRect GetBounds() override;
   virtual LayoutDeviceIntRect GetScreenBounds() override;
-  virtual MOZ_MUST_USE nsresult GetRestoredBounds(LayoutDeviceIntRect& aRect) override;
+  [[nodiscard]] virtual nsresult GetRestoredBounds(LayoutDeviceIntRect& aRect) override;
   virtual LayoutDeviceIntRect GetClientBounds() override;
   virtual LayoutDeviceIntPoint GetClientOffset() override;
   void                    SetBackgroundColor(const nscolor& aColor) override;