Bug 1435483 part 21. Remove nsIException::ToString. r=qdot

MozReview-Commit-ID: 17yuhlqzbr2

dom/base/DOMException.cpp

@@ -256,7 +256,7 @@ Exception::GetFilename(JSContext* aCx, nsAString& aFilename)
   aFilename.Truncate();
 }
 
-NS_IMETHODIMP
+void
 Exception::ToString(JSContext* aCx, nsACString& _retval)
 {
   static const char defaultMsg[] = "<no message>";
@@ -291,7 +291,6 @@ Exception::ToString(JSContext* aCx, nsACString& _retval)
   _retval.Truncate();
   _retval.AppendPrintf(format, msg, static_cast<uint32_t>(mResult), resultName,
                        location.get(), data);
-  return NS_OK;
 }
 
 JSObject*
@@ -353,11 +352,7 @@ void
 Exception::Stringify(JSContext* aCx, nsString& retval)
 {
   nsCString str;
-#ifdef DEBUG
-  DebugOnly<nsresult> rv =
-#endif
   ToString(aCx, str);
-  MOZ_ASSERT(NS_SUCCEEDED(rv));
   CopyUTF8toUTF16(str, retval);
 }
 
@@ -392,7 +387,7 @@ DOMException::GetCode(uint16_t* aCode)
   return NS_OK;
 }
 
-NS_IMETHODIMP
+void
 DOMException::ToString(JSContext* aCx, nsACString& aReturn)
 {
   aReturn.Truncate();
@@ -414,8 +409,6 @@ DOMException::ToString(JSContext* aCx, nsACString& aReturn)
 
   aReturn.AppendPrintf(format, msg, mCode, static_cast<uint32_t>(mResult), resultName,
                        location.get());
-
-  return NS_OK;
 }
 
 void

dom/base/DOMException.h

@@ -61,6 +61,9 @@ public:
   {
     return mResult;
   }
+  // DOMException wants different ToString behavior, so allow it to override.
+  virtual void ToString(JSContext* aCx, nsACString& aReturn);
+
 
   // Cruft used by XPConnect for exceptions originating in JS implemented
   // components.
@@ -151,9 +154,6 @@ public:
   NS_DECL_ISUPPORTS_INHERITED
   NS_DECL_NSIDOMDOMEXCEPTION
 
-  // nsIException overrides
-  NS_IMETHOD ToString(JSContext* aCx, nsACString& aReturn) override;
-
   // nsWrapperCache overrides
   virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
     override;
@@ -171,6 +171,9 @@ public:
   // Intentionally shadow the Exception version.
   void GetName(nsString& retval);
 
+  // Exception overrides
+  void ToString(JSContext* aCx, nsACString& aReturn) override;
+
   virtual void GetErrorMessage(nsAString& aRetVal) override
   {
     // See the comment in Exception::GetErrorMessage.

js/xpconnect/src/XPCWrappedJSClass.cpp

@@ -956,8 +956,8 @@ nsXPCWrappedJSClass::CheckForException(XPCCallContext & ccx,
                 fputs(line, stdout);
                 fputs(preamble, stdout);
                 nsCString text;
-                if (NS_SUCCEEDED(xpc_exception->ToString(cx, text)) &&
-                    !text.IsEmpty()) {
+                xpc_exception->ToString(cx, text);
+                if (!text.IsEmpty()) {
                     fputs(text.get(), stdout);
                     fputs("\n", stdout);
                 } else
@@ -970,7 +970,6 @@ nsXPCWrappedJSClass::CheckForException(XPCCallContext & ccx,
             nsCOMPtr<nsIConsoleService> consoleService
                 (do_GetService(XPC_CONSOLE_CONTRACTID));
             if (nullptr != consoleService) {
-                nsresult rv;
                 nsCOMPtr<nsIScriptError> scriptError =
                     do_QueryInterface(xpc_exception->GetData());
 
@@ -980,32 +979,31 @@ nsXPCWrappedJSClass::CheckForException(XPCCallContext & ccx,
                     scriptError = do_CreateInstance(XPC_SCRIPT_ERROR_CONTRACTID);
                     if (nullptr != scriptError) {
                         nsCString newMessage;
-                        rv = xpc_exception->ToString(cx, newMessage);
-                        if (NS_SUCCEEDED(rv)) {
-                            // try to get filename, lineno from the first
-                            // stack frame location.
-                            int32_t lineNumber = 0;
-                            nsString sourceName;
+                        xpc_exception->ToString(cx, newMessage);
+                        // try to get filename, lineno from the first
+                        // stack frame location.
+                        int32_t lineNumber = 0;
+                        nsString sourceName;
 
-                            nsCOMPtr<nsIStackFrame> location =
-                                xpc_exception->GetLocation();
-                            if (location) {
-                                // Get line number.
-                                lineNumber = location->GetLineNumber(cx);
+                        nsCOMPtr<nsIStackFrame> location =
+                            xpc_exception->GetLocation();
+                        if (location) {
+                            // Get line number.
+                            lineNumber = location->GetLineNumber(cx);
 
-                                // get a filename.
-                                location->GetFilename(cx, sourceName);
-                            }
-
-                            rv = scriptError->InitWithWindowID(NS_ConvertUTF8toUTF16(newMessage),
-                                                               sourceName,
-                                                               EmptyString(),
-                                                               lineNumber, 0, 0,
-                                                               "XPConnect JavaScript",
-                                                               nsJSUtils::GetCurrentlyRunningCodeInnerWindowID(cx));
-                            if (NS_FAILED(rv))
-                                scriptError = nullptr;
+                            // get a filename.
+                            location->GetFilename(cx, sourceName);
                         }
+
+                        nsresult rv =
+                            scriptError->InitWithWindowID(NS_ConvertUTF8toUTF16(newMessage),
+                                                          sourceName,
+                                                          EmptyString(),
+                                                          lineNumber, 0, 0,
+                                                          "XPConnect JavaScript",
+                                                          nsJSUtils::GetCurrentlyRunningCodeInnerWindowID(cx));
+                        if (NS_FAILED(rv))
+                            scriptError = nullptr;
                     }
                 }
                 if (nullptr != scriptError)

xpcom/base/nsIException.idl

@@ -65,10 +65,11 @@ interface nsIStackFrame : nsISupports
     void toStringInfallible(in JSContext aCx, out AUTF8String aString);
 };
 
+// This interface only exists because of all the JS consumers doing
+// "instanceof Ci.nsIException".  We should switch them to something else and
+// get rid of it; bug 1435856 tracks that.  C++ code should NOT use this; use
+// mozilla::dom::Exception instead.
 [scriptable, builtinclass, uuid(4371b5bf-6845-487f-8d9d-3f1e4a9badd2)]
 interface nsIException : nsISupports
 {
-    // A generic formatter - make it suitable to print, etc.
-    [implicit_jscontext]
-    AUTF8String toString();
 };