Issue #2342: Use [[nodiscard]] in /netwerk

19 files changed, 58 insertions, 62 deletions

diff --git a/netwerk/base/nsNetUtil.h b/netwerk/base/nsNetUtil.h
index 53fa679879..bc92301014 100644
--- a/netwerk/base/nsNetUtil.h
+++ b/netwerk/base/nsNetUtil.h
@@ -527,7 +527,7 @@ nsresult NS_BackgroundOutputStream(nsIOutputStream **result,
                                    uint32_t          segmentSize  = 0,
                                    uint32_t          segmentCount = 0);
 
-MOZ_MUST_USE nsresult
+[[nodiscard]] nsresult
 NS_NewBufferedInputStream(nsIInputStream **result,
                           nsIInputStream  *str,
                           uint32_t         bufferSize);
diff --git a/netwerk/base/nsNetUtilInlines.h b/netwerk/base/nsNetUtilInlines.h
index ea05bd1307..7b5ac15330 100644
--- a/netwerk/base/nsNetUtilInlines.h
+++ b/netwerk/base/nsNetUtilInlines.h
@@ -327,7 +327,7 @@ NS_NewLocalFileOutputStream(nsIOutputStream **result,
     return rv;
 }
 
-INLINE_IF_EXTERN MOZ_MUST_USE nsresult
+[[nodiscard]] INLINE_IF_EXTERN nsresult
 NS_NewBufferedInputStream(nsIInputStream **result,
                           nsIInputStream  *str,
                           uint32_t         bufferSize)
diff --git a/netwerk/base/nsStandardURL.cpp b/netwerk/base/nsStandardURL.cpp
index aa60b52cd5..be40f817ea 100644
--- a/netwerk/base/nsStandardURL.cpp
+++ b/netwerk/base/nsStandardURL.cpp
@@ -3523,8 +3523,7 @@ ToIPCSegment(const nsStandardURL::URLSegment& aSegment)
     return ipc::StandardURLSegment(aSegment.mPos, aSegment.mLen);
 }
 
-inline
-MOZ_MUST_USE bool
+[[nodiscard]] inline bool
 FromIPCSegment(const nsACString& aSpec, const ipc::StandardURLSegment& aSegment, nsStandardURL::URLSegment& aTarget)
 {
     // This seems to be just an empty segment.
diff --git a/netwerk/cache2/CacheFileChunk.cpp b/netwerk/cache2/CacheFileChunk.cpp
index 83d79f79fc..2eebd97e93 100644
--- a/netwerk/cache2/CacheFileChunk.cpp
+++ b/netwerk/cache2/CacheFileChunk.cpp
@@ -76,7 +76,7 @@ CacheFileChunkBuffer::FillInvalidRanges(CacheFileChunkBuffer *aOther,
   return NS_OK;
 }
 
-MOZ_MUST_USE nsresult
+[[nodiscard]] nsresult
 CacheFileChunkBuffer::EnsureBufSize(uint32_t aBufSize)
 {
   AssertOwnsLock();
diff --git a/netwerk/ipc/NeckoParent.h b/netwerk/ipc/NeckoParent.h
index fe1d77e482..068e96d499 100644
--- a/netwerk/ipc/NeckoParent.h
+++ b/netwerk/ipc/NeckoParent.h
@@ -32,8 +32,7 @@ public:
   NeckoParent();
   virtual ~NeckoParent();
 
-  MOZ_MUST_USE
-  static const char *
+  [[nodiscard]] static const char*
   GetValidatedOriginAttributes(const SerializedLoadContext& aSerialized,
                                PContentParent* aBrowser,
                                nsIPrincipal* aRequestingPrincipal,
@@ -46,8 +45,7 @@ public:
    *
    * Returns null if successful, or an error string if failed.
    */
-  MOZ_MUST_USE
-  static const char*
+  [[nodiscard]] static const char*
   CreateChannelLoadContext(const PBrowserOrId& aBrowser,
                            PContentParent* aContent,
                            const SerializedLoadContext& aSerialized,
diff --git a/netwerk/protocol/about/nsAboutCache.h b/netwerk/protocol/about/nsAboutCache.h
index 6fb837eacd..a1fe77324f 100644
--- a/netwerk/protocol/about/nsAboutCache.h
+++ b/netwerk/protocol/about/nsAboutCache.h
@@ -49,10 +49,10 @@ public:
 
     nsAboutCache() {}
 
-    static MOZ_MUST_USE nsresult
+    [[nodiscard]] static nsresult
     Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);
 
-    static MOZ_MUST_USE nsresult
+    [[nodiscard]] static nsresult
     GetStorage(nsACString const & storageName, nsILoadContextInfo* loadInfo,
                nsICacheStorage **storage);
 
@@ -75,13 +75,13 @@ protected:
         virtual ~Channel() {}
 
     public:
-        MOZ_MUST_USE nsresult Init(nsIURI* aURI, nsILoadInfo* aLoadInfo);
-        MOZ_MUST_USE nsresult ParseURI(nsIURI * uri, nsACString & storage);
+        [[nodiscard]] nsresult Init(nsIURI* aURI, nsILoadInfo* aLoadInfo);
+        [[nodiscard]] nsresult ParseURI(nsIURI * uri, nsACString & storage);
 
         // Finds a next storage we wish to visit (we use this method
         // even there is a specified storage name, which is the only
         // one in the list then.)  Posts FireVisitStorage() when found.
-        MOZ_MUST_USE nsresult VisitNextStorage();
+        [[nodiscard]] nsresult VisitNextStorage();
         // Helper method that calls VisitStorage() for the current storage.
         // When it fails, OnCacheEntryVisitCompleted is simulated to close
         // the output stream and thus the about:cache channel.
@@ -89,13 +89,13 @@ protected:
         // Kiks the visit cycle for the given storage, names can be:
         // "disk", "memory", "appcache"
         // Note: any newly added storage type has to be manually handled here.
-        MOZ_MUST_USE nsresult VisitStorage(nsACString const & storageName);
+        [[nodiscard]] nsresult VisitStorage(nsACString const & storageName);
 
         // Writes content of mBuffer to mStream and truncates
         // the buffer.  It may fail when the input stream is closed by canceling
         // the input stream channel.  It can be used to stop the cache iteration
         // process.
-        MOZ_MUST_USE nsresult FlushBuffer();
+        [[nodiscard]] nsresult FlushBuffer();
 
         // Whether we are showing overview status of all available
         // storages.
diff --git a/netwerk/protocol/about/nsAboutCacheEntry.h b/netwerk/protocol/about/nsAboutCacheEntry.h
index 8bfa0aa723..f770a9fa2e 100644
--- a/netwerk/protocol/about/nsAboutCacheEntry.h
+++ b/netwerk/protocol/about/nsAboutCacheEntry.h
@@ -53,20 +53,20 @@ private:
         virtual ~Channel() {}
 
     public:
-        MOZ_MUST_USE nsresult Init(nsIURI* uri, nsILoadInfo* aLoadInfo);
-
-        MOZ_MUST_USE nsresult GetContentStream(nsIURI *, nsIInputStream **);
-        MOZ_MUST_USE nsresult OpenCacheEntry(nsIURI *);
-        MOZ_MUST_USE nsresult OpenCacheEntry();
-        MOZ_MUST_USE nsresult WriteCacheEntryDescription(nsICacheEntry *);
-        MOZ_MUST_USE nsresult WriteCacheEntryUnavailable();
-        MOZ_MUST_USE nsresult ParseURI(nsIURI *uri, nsACString &storageName,
+        [[nodiscard]] nsresult Init(nsIURI* uri, nsILoadInfo* aLoadInfo);
+
+        [[nodiscard]] nsresult GetContentStream(nsIURI *, nsIInputStream **);
+        [[nodiscard]] nsresult OpenCacheEntry(nsIURI *);
+        [[nodiscard]] nsresult OpenCacheEntry();
+        [[nodiscard]] nsresult WriteCacheEntryDescription(nsICacheEntry *);
+        [[nodiscard]] nsresult WriteCacheEntryUnavailable();
+        [[nodiscard]] nsresult ParseURI(nsIURI *uri, nsACString &storageName,
                                        nsILoadContextInfo **loadInfo,
                                        nsCString &enahnceID,
                                        nsIURI **cacheUri);
         void CloseContent();
 
-        static MOZ_MUST_USE nsresult
+        [[nodiscard]] static nsresult
         PrintCacheData(nsIInputStream *aInStream,
                        void *aClosure,
                        const char *aFromSegment,
diff --git a/netwerk/protocol/about/nsAboutProtocolUtils.h b/netwerk/protocol/about/nsAboutProtocolUtils.h
index c5946412b0..ec4e51e857 100644
--- a/netwerk/protocol/about/nsAboutProtocolUtils.h
+++ b/netwerk/protocol/about/nsAboutProtocolUtils.h
@@ -12,7 +12,7 @@
 #include "nsServiceManagerUtils.h"
 #include "prtime.h"
 
-inline MOZ_MUST_USE nsresult
+[[nodiscard]] inline nsresult
 NS_GetAboutModuleName(nsIURI *aAboutURI, nsCString& aModule)
 {
 #ifdef DEBUG
diff --git a/netwerk/protocol/data/DataChannelParent.h b/netwerk/protocol/data/DataChannelParent.h
index 48c610d6a4..c36a3c8822 100644
--- a/netwerk/protocol/data/DataChannelParent.h
+++ b/netwerk/protocol/data/DataChannelParent.h
@@ -26,7 +26,7 @@ public:
     NS_DECL_NSIREQUESTOBSERVER
     NS_DECL_NSISTREAMLISTENER
 
-    MOZ_MUST_USE bool Init(const uint32_t& aArgs);
+    [[nodiscard]] bool Init(const uint32_t& aArgs);
 
 private:
     ~DataChannelParent();
diff --git a/netwerk/protocol/data/nsDataChannel.h b/netwerk/protocol/data/nsDataChannel.h
index c986fba1e9..b5599f0909 100644
--- a/netwerk/protocol/data/nsDataChannel.h
+++ b/netwerk/protocol/data/nsDataChannel.h
@@ -20,9 +20,9 @@ public:
     }
 
 protected:
-    virtual MOZ_MUST_USE nsresult OpenContentStream(bool async,
-                                                    nsIInputStream **result,
-                                                    nsIChannel** channel);
+    [[nodiscard]] virtual nsresult OpenContentStream(bool async,
+                                                     nsIInputStream **result,
+                                                     nsIChannel** channel);
 };
 
 #endif /* nsDataChannel_h___ */
diff --git a/netwerk/protocol/data/nsDataHandler.h b/netwerk/protocol/data/nsDataHandler.h
index 75f873e174..3c4adbffa3 100644
--- a/netwerk/protocol/data/nsDataHandler.h
+++ b/netwerk/protocol/data/nsDataHandler.h
@@ -24,18 +24,18 @@ public:
     nsDataHandler();
 
     // Define a Create method to be used with a factory:
-    static MOZ_MUST_USE nsresult
+    [[nodiscard]] static nsresult
     Create(nsISupports* aOuter, const nsIID& aIID, void* *aResult);
 
     // Parse a data: URI and return the individual parts
     // (the given spec will temporarily be modified but will be returned
     //  to the original before returning)
     // contentCharset and dataBuffer can be nullptr if they are not needed.
-    static MOZ_MUST_USE nsresult ParseURI(nsCString& spec,
-                                          nsCString& contentType,
-                                          nsCString* contentCharset,
-                                          bool& isBase64,
-                                          nsCString* dataBuffer);
+    [[nodiscard]] static nsresult ParseURI(nsCString& spec,
+                                           nsCString& contentType,
+                                           nsCString* contentCharset,
+                                           bool& isBase64,
+                                           nsCString* dataBuffer);
 };
 
 #endif /* nsDataHandler_h___ */
diff --git a/netwerk/protocol/device/nsDeviceCaptureProvider.h b/netwerk/protocol/device/nsDeviceCaptureProvider.h
index 024f6689d6..423ef231b8 100644
--- a/netwerk/protocol/device/nsDeviceCaptureProvider.h
+++ b/netwerk/protocol/device/nsDeviceCaptureProvider.h
@@ -23,9 +23,9 @@ struct nsCaptureParams {
 class nsDeviceCaptureProvider : public nsISupports
 {
 public:
-  virtual MOZ_MUST_USE nsresult Init(nsACString& aContentType,
-                                     nsCaptureParams* aParams,
-                                     nsIInputStream** aStream) = 0;
+  [[nodiscard]] virtual nsresult Init(nsACString& aContentType,
+                                      nsCaptureParams* aParams,
+                                      nsIInputStream** aStream) = 0;
 };
 
 #endif
diff --git a/netwerk/protocol/device/nsDeviceChannel.h b/netwerk/protocol/device/nsDeviceChannel.h
index 8c3e447931..f58b2716b5 100644
--- a/netwerk/protocol/device/nsDeviceChannel.h
+++ b/netwerk/protocol/device/nsDeviceChannel.h
@@ -15,10 +15,10 @@ public:
 
   nsDeviceChannel();
 
-  MOZ_MUST_USE nsresult Init(nsIURI* uri);
-  MOZ_MUST_USE nsresult OpenContentStream(bool aAsync,
-                                          nsIInputStream **aStream,
-                                          nsIChannel **aChannel) override;
+  [[nodiscard]] nsresult Init(nsIURI* uri);
+  [[nodiscard]] nsresult OpenContentStream(bool aAsync,
+                                           nsIInputStream **aStream,
+                                           nsIChannel **aChannel) override;
 
 protected:
   ~nsDeviceChannel();
diff --git a/netwerk/protocol/device/nsDeviceProtocolHandler.h b/netwerk/protocol/device/nsDeviceProtocolHandler.h
index dee9b4f8f0..8188e3e9e0 100644
--- a/netwerk/protocol/device/nsDeviceProtocolHandler.h
+++ b/netwerk/protocol/device/nsDeviceProtocolHandler.h
@@ -26,7 +26,7 @@ public:
 
   nsDeviceProtocolHandler() {}
 
-  MOZ_MUST_USE nsresult Init();
+  [[nodiscard]] nsresult Init();
 };
 
 } // namespace net
diff --git a/netwerk/protocol/file/nsFileChannel.h b/netwerk/protocol/file/nsFileChannel.h
index 4f28b9ed01..090b4bb403 100644
--- a/netwerk/protocol/file/nsFileChannel.h
+++ b/netwerk/protocol/file/nsFileChannel.h
@@ -28,13 +28,13 @@ protected:
   // method also returns a best guess at the content-type for the data stream.
   // NOTE: If the channel has a type hint set, contentType will be left
   // untouched. The caller should not use it in that case.
-  MOZ_MUST_USE nsresult MakeFileInputStream(nsIFile *file,
-                                            nsCOMPtr<nsIInputStream> &stream,
-                                            nsCString &contentType, bool async);
+  [[nodiscard]] nsresult MakeFileInputStream(nsIFile *file,
+                                             nsCOMPtr<nsIInputStream> &stream,
+                                             nsCString &contentType, bool async);
 
-  virtual MOZ_MUST_USE nsresult OpenContentStream(bool async,
-                                                  nsIInputStream **result,
-                                                  nsIChannel** channel) override;
+  [[nodiscard]] virtual nsresult OpenContentStream(bool async,
+                                                   nsIInputStream **result,
+                                                   nsIChannel** channel) override;
 
 private:
   nsCOMPtr<nsIInputStream> mUploadStream;
diff --git a/netwerk/protocol/file/nsFileProtocolHandler.h b/netwerk/protocol/file/nsFileProtocolHandler.h
index 211eb2873e..1da0713284 100644
--- a/netwerk/protocol/file/nsFileProtocolHandler.h
+++ b/netwerk/protocol/file/nsFileProtocolHandler.h
@@ -21,7 +21,7 @@ public:
 
     nsFileProtocolHandler();
 
-    MOZ_MUST_USE nsresult Init();
+    [[nodiscard]] nsresult Init();
 };
 
 #endif // !nsFileProtocolHandler_h__
diff --git a/netwerk/protocol/http/TunnelUtils.h b/netwerk/protocol/http/TunnelUtils.h
index 4a003082ec..2d56fb0932 100644
--- a/netwerk/protocol/http/TunnelUtils.h
+++ b/netwerk/protocol/http/TunnelUtils.h
@@ -122,7 +122,7 @@ public:
   nsresult CommitToSegmentSize(uint32_t size, bool forceCommitment) override;
   nsresult GetTransactionSecurityInfo(nsISupports **) override;
   nsresult NudgeTunnel(NudgeTunnelCallback *callback);
-  MOZ_MUST_USE nsresult SetProxiedTransaction(nsAHttpTransaction *aTrans,
+  [[nodiscard]] nsresult SetProxiedTransaction(nsAHttpTransaction *aTrans,
                                               nsAHttpTransaction *aSpdyConnectTransaction = nullptr);
   void     newIODriver(nsIAsyncInputStream *aSocketIn,
                        nsIAsyncOutputStream *aSocketOut,
diff --git a/netwerk/protocol/http/nsHttpChannel.h b/netwerk/protocol/http/nsHttpChannel.h
index 2681f34764..8ae7035822 100644
--- a/netwerk/protocol/http/nsHttpChannel.h
+++ b/netwerk/protocol/http/nsHttpChannel.h
@@ -282,7 +282,7 @@ private:
     bool     RequestIsConditional();
     nsresult BeginConnect();
     void     HandleBeginConnectContinue();
-    MOZ_MUST_USE nsresult BeginConnectContinue();
+    [[nodiscard]] nsresult BeginConnectContinue();
     nsresult ContinueBeginConnectWithResult();
     void     ContinueBeginConnect();
     nsresult Connect();
diff --git a/netwerk/sctp/datachannel/DataChannel.h b/netwerk/sctp/datachannel/DataChannel.h
index 33458e6c2b..02dca930c5 100644
--- a/netwerk/sctp/datachannel/DataChannel.h
+++ b/netwerk/sctp/datachannel/DataChannel.h
@@ -140,15 +140,14 @@ public:
     PARTIAL_RELIABLE_TIMED = 2
   } Type;
 
-  MOZ_MUST_USE
-  already_AddRefed<DataChannel> Open(const nsACString& label,
-                                     const nsACString& protocol,
-                                     Type type, bool inOrder,
-                                     uint32_t prValue,
-                                     DataChannelListener *aListener,
-                                     nsISupports *aContext,
-                                     bool aExternalNegotiated,
-                                     uint16_t aStream);
+  [[nodiscard]] already_AddRefed<DataChannel> Open(const nsACString& label,
+                                                   const nsACString& protocol,
+                                                   Type type, bool inOrder,
+                                                   uint32_t prValue,
+                                                   DataChannelListener *aListener,
+                                                   nsISupports *aContext,
+                                                   bool aExternalNegotiated,
+                                                   uint16_t aStream);
 
   void Close(DataChannel *aChannel);
   // CloseInt() must be called with mLock held