Merge pull request #51 from ParsePlatform/nlutsenko.xctoolchain

Update xctoolchain, fix new static analyzer warnings.

Author: nlutsenko

ParseFacebookUtils/Internal/AuthenticationProvider/PFFacebookAuthenticationProvider.m

@@ -25,7 +25,7 @@ @implementation PFFacebookAuthenticationProvider
 - (instancetype)initWithApplication:(UIApplication *)application
                       launchOptions:(nullable NSDictionary *)launchOptions {
     self = [super init];
-    if (!self) return nil;
+    if (!self) return self;
 
     [[FBSDKApplicationDelegate sharedInstance] application:[UIApplication sharedApplication]
                              didFinishLaunchingWithOptions:launchOptions];

ParseFacebookUtils/Internal/AuthenticationProvider/iOS/PFFacebookMobileAuthenticationProvider.m

@@ -31,7 +31,7 @@ @implementation PFFacebookMobileAuthenticationProvider
 - (instancetype)initWithApplication:(UIApplication *)application
                       launchOptions:(nullable NSDictionary *)launchOptions {
     self = [super initWithApplication:application launchOptions:launchOptions];
-    if (!self) return nil;
+    if (!self) return self;
 
     _loginManager = [[FBSDKLoginManager alloc] init];
 

ParseFacebookUtils/Internal/PFFacebookPrivateUtilities.h

@@ -30,9 +30,9 @@ NS_ASSUME_NONNULL_BEGIN
 + (NSDictionary *)userAuthenticationDataWithFacebookUserId:(NSString *)userId
                                                accessToken:(NSString *)accessToken
                                             expirationDate:(NSDate *)expirationDate;
-+ (NSDictionary *)userAuthenticationDataFromAccessToken:(FBSDKAccessToken *)token;
++ (nullable NSDictionary *)userAuthenticationDataFromAccessToken:(FBSDKAccessToken *)token;
 
-+ (FBSDKAccessToken *)facebookAccessTokenFromUserAuthenticationData:(nullable NSDictionary<NSString *, NSString *> *)authData;
++ (nullable FBSDKAccessToken *)facebookAccessTokenFromUserAuthenticationData:(nullable NSDictionary<NSString *, NSString *> *)authData;
 
 @end
 

ParseFacebookUtils/Internal/PFFacebookPrivateUtilities.m

@@ -33,7 +33,7 @@ + (NSDictionary *)userAuthenticationDataWithFacebookUserId:(NSString *)userId
               @"expiration_date" : [[NSDateFormatter pffb_preciseDateFormatter] stringFromDate:expirationDate] };
 }
 
-+ (NSDictionary *)userAuthenticationDataFromAccessToken:(FBSDKAccessToken *)token {
++ (nullable NSDictionary *)userAuthenticationDataFromAccessToken:(FBSDKAccessToken *)token {
     if (!token.userID || !token.tokenString || !token.expirationDate) {
         return nil;
     }
@@ -43,7 +43,7 @@ + (NSDictionary *)userAuthenticationDataFromAccessToken:(FBSDKAccessToken *)toke
                                            expirationDate:token.expirationDate];
 }
 
-+ (FBSDKAccessToken *)facebookAccessTokenFromUserAuthenticationData:(nullable NSDictionary<NSString *, NSString *> *)authData {
++ (nullable FBSDKAccessToken *)facebookAccessTokenFromUserAuthenticationData:(nullable NSDictionary<NSString *, NSString *> *)authData {
     NSString *accessToken = authData[@"access_token"];
     NSString *expirationDateString = authData[@"expiration_date"];
     if (!accessToken || !expirationDateString) {