diff --git a/Signal.xcodeproj/project.pbxproj b/Signal.xcodeproj/project.pbxproj
index f085841ad..77943b6aa 100644
--- a/Signal.xcodeproj/project.pbxproj
+++ b/Signal.xcodeproj/project.pbxproj
@@ -3906,6 +3906,9 @@
 			buildSettings = {
 				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
+				CLANG_ANALYZER_SECURITY_FLOATLOOPCOUNTER = YES;
+				CLANG_ANALYZER_SECURITY_INSECUREAPI_RAND = YES;
+				CLANG_ANALYZER_SECURITY_INSECUREAPI_STRCPY = YES;
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_ENTITLEMENTS = Signal/Signal.entitlements;
 				CODE_SIGN_IDENTITY = "iPhone Developer";
@@ -3951,6 +3954,7 @@
 				PRODUCT_NAME = Signal;
 				PROVISIONING_PROFILE = "";
 				PROVISIONING_PROFILE_SPECIFIER = "";
+				RUN_CLANG_STATIC_ANALYZER = YES;
 				SDKROOT = iphoneos;
 				SWIFT_OBJC_BRIDGING_HEADER = "Signal/src/Signal-Bridging-Header.h";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
@@ -3968,6 +3972,9 @@
 			buildSettings = {
 				ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES = YES;
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
+				CLANG_ANALYZER_SECURITY_FLOATLOOPCOUNTER = YES;
+				CLANG_ANALYZER_SECURITY_INSECUREAPI_RAND = YES;
+				CLANG_ANALYZER_SECURITY_INSECUREAPI_STRCPY = YES;
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_ENTITLEMENTS = Signal/Signal.entitlements;
 				CODE_SIGN_IDENTITY = "iPhone Developer";
@@ -4012,6 +4019,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = org.whispersystems.signal;
 				PRODUCT_NAME = Signal;
 				PROVISIONING_PROFILE = "";
+				RUN_CLANG_STATIC_ANALYZER = YES;
 				SDKROOT = iphoneos;
 				SWIFT_OBJC_BRIDGING_HEADER = "Signal/src/Signal-Bridging-Header.h";
 				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
diff --git a/Signal/src/ViewControllers/AppSettings/NotificationSettingsOptionsViewController.m b/Signal/src/ViewControllers/AppSettings/NotificationSettingsOptionsViewController.m
index 5944955a0..9c1b736df 100644
--- a/Signal/src/ViewControllers/AppSettings/NotificationSettingsOptionsViewController.m
+++ b/Signal/src/ViewControllers/AppSettings/NotificationSettingsOptionsViewController.m
@@ -11,6 +11,8 @@
 
 - (void)viewDidLoad
 {
+    [super viewDidLoad];
+    
     [self updateTableContents];
 }
 
diff --git a/Signal/src/ViewControllers/AppSettings/NotificationSettingsViewController.m b/Signal/src/ViewControllers/AppSettings/NotificationSettingsViewController.m
index 62fd0b92c..bfd45930d 100644
--- a/Signal/src/ViewControllers/AppSettings/NotificationSettingsViewController.m
+++ b/Signal/src/ViewControllers/AppSettings/NotificationSettingsViewController.m
@@ -22,6 +22,8 @@
 
 - (void)viewDidAppear:(BOOL)animated
 {
+    [super viewDidAppear:animated];
+
     [self updateTableContents];
 }
 
diff --git a/Signal/src/ViewControllers/AppSettings/OWSBackupSettingsViewController.m b/Signal/src/ViewControllers/AppSettings/OWSBackupSettingsViewController.m
index 9a991967f..68139aa8a 100644
--- a/Signal/src/ViewControllers/AppSettings/OWSBackupSettingsViewController.m
+++ b/Signal/src/ViewControllers/AppSettings/OWSBackupSettingsViewController.m
@@ -45,6 +45,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)viewDidAppear:(BOOL)animated
 {
+    [super viewDidAppear:animated];
     [self updateTableContents];
 }
 
diff --git a/Signal/src/ViewControllers/AppSettings/OWSLinkedDevicesTableViewController.m b/Signal/src/ViewControllers/AppSettings/OWSLinkedDevicesTableViewController.m
index 928adc51a..9a4878119 100644
--- a/Signal/src/ViewControllers/AppSettings/OWSLinkedDevicesTableViewController.m
+++ b/Signal/src/ViewControllers/AppSettings/OWSLinkedDevicesTableViewController.m
@@ -312,7 +312,7 @@ int const OWSLinkedDevicesTableViewControllerSectionAddDevice = 1;
         return cell;
     } else {
         DDLogError(@"Unknown section: %@", indexPath);
-        return nil;
+        return [UITableViewCell new];
     }
 }
 
diff --git a/Signal/src/ViewControllers/AppSettings/OWSSoundSettingsViewController.m b/Signal/src/ViewControllers/AppSettings/OWSSoundSettingsViewController.m
index 1a65c77af..ed1addd87 100644
--- a/Signal/src/ViewControllers/AppSettings/OWSSoundSettingsViewController.m
+++ b/Signal/src/ViewControllers/AppSettings/OWSSoundSettingsViewController.m
@@ -38,6 +38,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)viewDidAppear:(BOOL)animated
 {
+    [super viewDidAppear:animated];
+
     [self updateTableContents];
 }
 
diff --git a/Signal/src/ViewControllers/AppSettings/PrivacySettingsTableViewController.m b/Signal/src/ViewControllers/AppSettings/PrivacySettingsTableViewController.m
index 96cda65f7..0fb95b8ed 100644
--- a/Signal/src/ViewControllers/AppSettings/PrivacySettingsTableViewController.m
+++ b/Signal/src/ViewControllers/AppSettings/PrivacySettingsTableViewController.m
@@ -30,6 +30,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)viewDidAppear:(BOOL)animated
 {
+    [super viewDidAppear:animated];
+
     [self updateTableContents];
 }
 
diff --git a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
index e8f04599d..6f3867dbb 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
@@ -1862,20 +1862,24 @@ typedef enum : NSUInteger {
     [self presentViewController:actionSheetController animated:YES completion:nil];
 }
 
-- (void)tappedNonBlockingIdentityChangeForRecipientId:(nullable NSString *)signalId
+- (void)tappedNonBlockingIdentityChangeForRecipientId:(nullable NSString *)signalIdParam
 {
-    if (signalId == nil) {
+    if (signalIdParam == nil) {
         if (self.thread.isGroupThread) {
             // Before 2.13 we didn't track the recipient id in the identity change error.
             DDLogWarn(@"%@ Ignoring tap on legacy nonblocking identity change since it has no signal id", self.logTag);
+            return;
+            
         } else {
             DDLogInfo(
                 @"%@ Assuming tap on legacy nonblocking identity change corresponds to current contact thread: %@",
                 self.logTag,
                 self.thread.contactIdentifier);
-            signalId = self.thread.contactIdentifier;
+            signalIdParam = self.thread.contactIdentifier;
         }
     }
+    
+    NSString *signalId = signalIdParam;
 
     [self showFingerprintWithRecipientId:signalId];
 }
diff --git a/Signal/src/ViewControllers/NewContactThreadViewController.m b/Signal/src/ViewControllers/NewContactThreadViewController.m
index 43c07c30f..3d10efb7c 100644
--- a/Signal/src/ViewControllers/NewContactThreadViewController.m
+++ b/Signal/src/ViewControllers/NewContactThreadViewController.m
@@ -907,7 +907,7 @@ NS_ASSUME_NONNULL_BEGIN
     return result;
 }
 
-- (NSString *)callingCodeForPossiblePhoneNumber:(NSString *)phoneNumber
+- (nullable NSString *)callingCodeForPossiblePhoneNumber:(NSString *)phoneNumber
 {
     OWSAssert([phoneNumber hasPrefix:@"+"]);
 
@@ -924,7 +924,7 @@ NS_ASSUME_NONNULL_BEGIN
     NSString *searchText = self.searchBar.text;
 
     if (searchText.length < 8) {
-        return nil;
+        return @[];
     }
 
     NSMutableSet<NSString *> *parsedPhoneNumbers = [NSMutableSet new];
@@ -935,7 +935,7 @@ NS_ASSUME_NONNULL_BEGIN
         NSString *phoneNumberString = phoneNumber.toE164;
 
         // Ignore phone numbers with an unrecognized calling code.
-        NSString *callingCode = [self callingCodeForPossiblePhoneNumber:phoneNumberString];
+        NSString *_Nullable callingCode = [self callingCodeForPossiblePhoneNumber:phoneNumberString];
         if (!callingCode) {
             continue;
         }