[ios, macos] Fixes for static analyzer warnings (#14453)

14 files changed, 62 insertions, 28 deletions

diff --git a/platform/darwin/src/MGLStyleValue_Private.h b/platform/darwin/src/MGLStyleValue_Private.h
index fee34b4b71..376bf5e73b 100644
--- a/platform/darwin/src/MGLStyleValue_Private.h
+++ b/platform/darwin/src/MGLStyleValue_Private.h
@@ -291,7 +291,7 @@ private: // Private utilities for converting from mbgl to mgl values
     }
 
     // Array
-    static ObjCType toMGLRawStyleValue(const std::vector<MBGLElement> &mbglStopValue) {
+    static NSArray<NSExpression*> *toMGLRawStyleValue(const std::vector<MBGLElement> &mbglStopValue) {
         NSMutableArray *array = [NSMutableArray arrayWithCapacity:mbglStopValue.size()];
         for (const auto &mbglElement: mbglStopValue) {
             [array addObject:[NSExpression expressionForConstantValue:toMGLRawStyleValue(mbglElement)]];
diff --git a/platform/darwin/src/NSExpression+MGLAdditions.h b/platform/darwin/src/NSExpression+MGLAdditions.h
index a19ec1af2e..9ef6623068 100644
--- a/platform/darwin/src/NSExpression+MGLAdditions.h
+++ b/platform/darwin/src/NSExpression+MGLAdditions.h
@@ -190,7 +190,7 @@ FOUNDATION_EXTERN MGL_EXPORT const MGLExpressionInterpolationMode MGLExpressionI
  @return An initialized expression equivalent to `object`, suitable for use as
     the value of a style layer attribute.
  */
-+ (instancetype)expressionWithMGLJSONObject:(id)object NS_SWIFT_NAME(init(mglJSONObject:));
++ (instancetype)expressionWithMGLJSONObject:(nullable id)object NS_SWIFT_NAME(init(mglJSONObject:));
 
 /**
  An equivalent Foundation object that can be serialized as JSON.
diff --git a/platform/darwin/src/NSExpression+MGLAdditions.mm b/platform/darwin/src/NSExpression+MGLAdditions.mm
index 9dad00e56e..026d8bec02 100644
--- a/platform/darwin/src/NSExpression+MGLAdditions.mm
+++ b/platform/darwin/src/NSExpression+MGLAdditions.mm
@@ -823,9 +823,14 @@ NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) {
                     minimum = [NSExpression expressionWithMGLJSONObject:valueExpression];
                 }
             }
-            NSExpression *stopExpression = [NSExpression expressionForConstantValue:stops];
-            return [NSExpression expressionForFunction:@"mgl_step:from:stops:"
-                                             arguments:@[inputExpression, minimum, stopExpression]];
+            
+            NSAssert(minimum, @"minimum should be non-nil");
+            if (minimum) {
+                NSExpression *stopExpression = [NSExpression expressionForConstantValue:stops];
+                return [NSExpression expressionForFunction:@"mgl_step:from:stops:"
+                                                 arguments:@[inputExpression, minimum, stopExpression]];
+            }
+            
         } else if ([op isEqualToString:@"zoom"]) {
             return NSExpression.zoomLevelVariableExpression;
         } else if ([op isEqualToString:@"heatmap-density"]) {
@@ -1030,7 +1035,11 @@ NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) {
                     expressionObject = @[@"get", pathComponent];
                 }
             }
-            return expressionObject;
+            
+            NSAssert(expressionObject.count > 0, @"expressionObject should be non-empty");
+
+            // Return a non-null value to quieten static analysis
+            return expressionObject ?: @[];
         }
             
         case NSFunctionExpressionType: {
diff --git a/platform/darwin/src/NSExpression+MGLPrivateAdditions.h b/platform/darwin/src/NSExpression+MGLPrivateAdditions.h
index 4ef49a2d15..54bc9068f4 100644
--- a/platform/darwin/src/NSExpression+MGLPrivateAdditions.h
+++ b/platform/darwin/src/NSExpression+MGLPrivateAdditions.h
@@ -13,8 +13,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface NSObject (MGLExpressionAdditions)
 
-- (NSNumber *)mgl_number;
-- (NSNumber *)mgl_numberWithFallbackValues:(id)fallbackValue, ... NS_REQUIRES_NIL_TERMINATION;
+- (nullable NSNumber *)mgl_number;
+- (nullable NSNumber *)mgl_numberWithFallbackValues:(id)fallbackValue, ... NS_REQUIRES_NIL_TERMINATION;
 
 @end
 
diff --git a/platform/darwin/src/NSPredicate+MGLPrivateAdditions.h b/platform/darwin/src/NSPredicate+MGLPrivateAdditions.h
index 1828009678..051a2775a1 100644
--- a/platform/darwin/src/NSPredicate+MGLPrivateAdditions.h
+++ b/platform/darwin/src/NSPredicate+MGLPrivateAdditions.h
@@ -10,15 +10,15 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (mbgl::style::Filter)mgl_filter;
 
-+ (instancetype)mgl_predicateWithFilter:(mbgl::style::Filter)filter;
++ (nullable instancetype)mgl_predicateWithFilter:(mbgl::style::Filter)filter;
 
 @end
 
 @interface NSPredicate (MGLExpressionAdditions)
 
-- (id)mgl_if:(id)firstValue, ...;
+- (nullable id)mgl_if:(id)firstValue, ...;
 
-- (id)mgl_match:(NSExpression *)firstCase, ...;
+- (nullable id)mgl_match:(NSExpression *)firstCase, ...;
 
 @end
 
diff --git a/platform/ios/app/MBXCustomLocationViewController.m b/platform/ios/app/MBXCustomLocationViewController.m
index 34887c5736..0473f8c2ef 100644
--- a/platform/ios/app/MBXCustomLocationViewController.m
+++ b/platform/ios/app/MBXCustomLocationViewController.m
@@ -168,6 +168,7 @@
 }
 
 - (void)viewWillDisappear:(BOOL)animated {
+    [super viewWillDisappear:animated];
     self.mapView.showsUserLocation = NO;
 }
 
diff --git a/platform/ios/app/MBXFrameTimeGraphView.m b/platform/ios/app/MBXFrameTimeGraphView.m
index f689768818..e881eb9f48 100644
--- a/platform/ios/app/MBXFrameTimeGraphView.m
+++ b/platform/ios/app/MBXFrameTimeGraphView.m
@@ -59,7 +59,12 @@ const CGFloat MBXFrameTimeBarWidth = 4.f;
         self.scrollLayer.frame = self.bounds;
 
         CGRect thresholdLineRect = CGRectMake(0, self.frame.size.height - [self renderDurationTargetMilliseconds], self.frame.size.width, 1);
-        self.thresholdLayer.path = CGPathCreateWithRect(thresholdLineRect, nil);
+        
+        {
+            CGPathRef path = CGPathCreateWithRect(thresholdLineRect, nil);        
+            self.thresholdLayer.path = path;
+            CGPathRelease(path);
+        }
     }
 }
 
diff --git a/platform/ios/app/MBXOrnamentsViewController.m b/platform/ios/app/MBXOrnamentsViewController.m
index 5c7aac7f88..861d5d7678 100644
--- a/platform/ios/app/MBXOrnamentsViewController.m
+++ b/platform/ios/app/MBXOrnamentsViewController.m
@@ -72,11 +72,13 @@
 }
 
 - (void)viewDidDisappear:(BOOL)animated {
+    [super viewDidDisappear:animated];
     [self.timer invalidate];
     self.timer = nil;
 }
 
 - (void)viewDidAppear:(BOOL)animated {
+    [super viewDidAppear:animated];
     self.timer = [NSTimer scheduledTimerWithTimeInterval:1
                                                   target:self
                                                 selector:@selector(onTimerTick)
diff --git a/platform/ios/app/MBXViewController.m b/platform/ios/app/MBXViewController.m
index 8d936d6a25..1bd2b2f5b3 100644
--- a/platform/ios/app/MBXViewController.m
+++ b/platform/ios/app/MBXViewController.m
@@ -155,13 +155,13 @@ CLLocationCoordinate2D randomWorldCoordinate() {
         {{ 12.966246,   77.586505 },    19000 }     // Bengaluru
     };
 
-    NSInteger index                   = drand48() * (sizeof(landmasses)/sizeof(landmasses[0]));
+    NSInteger index                   = arc4random_uniform(sizeof(landmasses)/sizeof(landmasses[0]));
     CLLocationCoordinate2D coordinate = landmasses[index].coordinate;
     CLLocationDistance radius         = landmasses[index].radius;
 
     // Now create a world coord
-    CLLocationDegrees heading          = drand48()*360.0;
-    CLLocationDistance distance        = drand48()*radius;
+    CLLocationDegrees heading          = (CLLocationDegrees)arc4random_uniform(360);
+    CLLocationDistance distance        = (CLLocationDistance)arc4random_uniform(radius);
     CLLocationCoordinate2D newLocation = coordinateCentered(coordinate, heading, distance);
     return newLocation;
 }
@@ -1775,8 +1775,8 @@ CLLocationCoordinate2D randomWorldCoordinate() {
     NSMutableArray *annotations = [[NSMutableArray alloc] initWithCapacity:numAnnotations];
     for (NSInteger i = 0; i<numAnnotations; i++) {
 
-        CLLocationDegrees heading          = drand48()*360.0;
-        CLLocationDistance distance        = drand48()*radius;
+        CLLocationDegrees heading          = (CLLocationDegrees)arc4random_uniform(360);
+        CLLocationDistance distance        = (CLLocationDistance)arc4random_uniform(radius);
         CLLocationCoordinate2D newLocation = coordinateCentered(coordinate, heading, distance);
 
         MBXDroppedPinAnnotation *annotation = [[MBXDroppedPinAnnotation alloc] init];
@@ -1814,12 +1814,12 @@ CLLocationCoordinate2D randomWorldCoordinate() {
     [self.mapView addAnnotation:annotation];
 
     // Add annotations around that coord
-    [self addAnnotations:50 aroundCoordinate:annotation.coordinate radius:100000.0]; // 100km
+    [self addAnnotations:50 aroundCoordinate:annotation.coordinate radius:100000]; // 100km
 
     MGLMapCamera *camera = [MGLMapCamera cameraLookingAtCenterCoordinate:annotation.coordinate
                                                                 altitude:10000.0
-                                                                   pitch:drand48()*60.0
-                                                                 heading:drand48()*360];
+                                                                   pitch:(CLLocationDegrees)arc4random_uniform(60)
+                                                                 heading:(CLLocationDegrees)arc4random_uniform(360)];
     [self.mapView flyToCamera:camera
                  withDuration:duration
                  peakAltitude:2000000.0
diff --git a/platform/ios/ios.xcodeproj/project.pbxproj b/platform/ios/ios.xcodeproj/project.pbxproj
index 9a7a0dd100..dd5ca9abcd 100644
--- a/platform/ios/ios.xcodeproj/project.pbxproj
+++ b/platform/ios/ios.xcodeproj/project.pbxproj
@@ -3630,8 +3630,12 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
+				CLANG_ANALYZER_GCD_PERFORMANCE = YES;
+				CLANG_ANALYZER_LOCALIZABILITY_EMPTY_CONTEXT = YES;
 				CLANG_ANALYZER_LOCALIZABILITY_NONLOCALIZED = YES;
 				CLANG_ANALYZER_NONNULL = YES;
+				CLANG_ANALYZER_SECURITY_INSECUREAPI_RAND = YES;
+				CLANG_ANALYZER_SECURITY_INSECUREAPI_STRCPY = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_ENABLE_MODULES = YES;
@@ -3899,8 +3903,12 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
+				CLANG_ANALYZER_GCD_PERFORMANCE = YES;
+				CLANG_ANALYZER_LOCALIZABILITY_EMPTY_CONTEXT = YES;
 				CLANG_ANALYZER_LOCALIZABILITY_NONLOCALIZED = YES;
 				CLANG_ANALYZER_NONNULL = YES;
+				CLANG_ANALYZER_SECURITY_INSECUREAPI_RAND = YES;
+				CLANG_ANALYZER_SECURITY_INSECUREAPI_STRCPY = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_ENABLE_MODULES = YES;
@@ -3967,8 +3975,12 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
+				CLANG_ANALYZER_GCD_PERFORMANCE = YES;
+				CLANG_ANALYZER_LOCALIZABILITY_EMPTY_CONTEXT = YES;
 				CLANG_ANALYZER_LOCALIZABILITY_NONLOCALIZED = YES;
 				CLANG_ANALYZER_NONNULL = YES;
+				CLANG_ANALYZER_SECURITY_INSECUREAPI_RAND = YES;
+				CLANG_ANALYZER_SECURITY_INSECUREAPI_STRCPY = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_ENABLE_MODULES = YES;
diff --git a/platform/ios/src/MGLMapView.h b/platform/ios/src/MGLMapView.h
index 607a197840..2423d62ee1 100644
--- a/platform/ios/src/MGLMapView.h
+++ b/platform/ios/src/MGLMapView.h
@@ -1130,7 +1130,7 @@ MGL_EXPORT
  `UIApplicationWillTerminateNotification`; you may receive a `nil` return value
  depending on the order of notification delivery.
  */
-- (MGLMapCamera *)cameraThatFitsCoordinateBounds:(MGLCoordinateBounds)bounds edgePadding:(UIEdgeInsets)insets;
+- (nullable MGLMapCamera *)cameraThatFitsCoordinateBounds:(MGLCoordinateBounds)bounds edgePadding:(UIEdgeInsets)insets;
 
 /**
  Returns the camera that best fits the given coordinate bounds, with the specified camera,
@@ -1150,7 +1150,7 @@ MGL_EXPORT
  `UIApplicationWillTerminateNotification`; you may receive a `nil` return value
  depending on the order of notification delivery.
  */
-- (MGLMapCamera *)camera:(MGLMapCamera *)camera fittingCoordinateBounds:(MGLCoordinateBounds)bounds edgePadding:(UIEdgeInsets)insets;
+- (nullable MGLMapCamera *)camera:(MGLMapCamera *)camera fittingCoordinateBounds:(MGLCoordinateBounds)bounds edgePadding:(UIEdgeInsets)insets;
 
 /**
  Returns the camera that best fits the given shape, with the specified camera,
@@ -1169,7 +1169,7 @@ MGL_EXPORT
  `UIApplicationWillTerminateNotification`; you may receive a `nil` return value
  depending on the order of notification delivery.
  */
-- (MGLMapCamera *)camera:(MGLMapCamera *)camera fittingShape:(MGLShape *)shape edgePadding:(UIEdgeInsets)insets;
+- (nullable MGLMapCamera *)camera:(MGLMapCamera *)camera fittingShape:(MGLShape *)shape edgePadding:(UIEdgeInsets)insets;
 
 /**
  Returns the camera that best fits the given shape, with the specified direction,
@@ -1187,7 +1187,7 @@ MGL_EXPORT
  `UIApplicationWillTerminateNotification`; you may receive a `nil` return value
  depending on the order of notification delivery.
  */
-- (MGLMapCamera *)cameraThatFitsShape:(MGLShape *)shape direction:(CLLocationDirection)direction edgePadding:(UIEdgeInsets)insets;
+- (nullable MGLMapCamera *)cameraThatFitsShape:(MGLShape *)shape direction:(CLLocationDirection)direction edgePadding:(UIEdgeInsets)insets;
 
 /**
  Returns the point in this view’s coordinate system on which to "anchor" in
diff --git a/platform/ios/src/MGLMapView.mm b/platform/ios/src/MGLMapView.mm
index 345ac64bc7..b5383ee30e 100644
--- a/platform/ios/src/MGLMapView.mm
+++ b/platform/ios/src/MGLMapView.mm
@@ -2481,7 +2481,7 @@ public:
     }];
     [attributionController addAction:telemetryAction];
     
-    NSString *cancelTitle = NSLocalizedStringWithDefaultValue(@"CANCEL", nil, nil, @"Cancel", @"");
+    NSString *cancelTitle = NSLocalizedStringWithDefaultValue(@"CANCEL", nil, nil, @"Cancel", @"Cancel");
     UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:cancelTitle
                                                            style:UIAlertActionStyleCancel
                                                          handler:NULL];
diff --git a/platform/ios/src/UIView+MGLAdditions.h b/platform/ios/src/UIView+MGLAdditions.h
index 85fea31ad2..ef074215b3 100644
--- a/platform/ios/src/UIView+MGLAdditions.h
+++ b/platform/ios/src/UIView+MGLAdditions.h
@@ -4,7 +4,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface UIView (MGLAdditions)
 
-- (UIViewController *)mgl_viewControllerForLayoutGuides;
+- (nullable UIViewController *)mgl_viewControllerForLayoutGuides;
 
 - (NSLayoutYAxisAnchor *)mgl_safeTopAnchor;
 
diff --git a/platform/ios/vendor/SMCalloutView/SMCalloutView.m b/platform/ios/vendor/SMCalloutView/SMCalloutView.m
index 66a7b5a7a7..0520ba08a5 100755
--- a/platform/ios/vendor/SMCalloutView/SMCalloutView.m
+++ b/platform/ios/vendor/SMCalloutView/SMCalloutView.m
@@ -554,13 +554,18 @@ NSTimeInterval const kMGLSMCalloutViewRepositionDelayForUIScrollView = 1.0/3.0;
         stretch.toValue = presenting ? @1.0 : @0.0;
         animation = stretch;
     }
-    
+
+    NSAssert(animation, @"There should be an animation");
+
     // CAAnimation is KVC compliant, so we can store whether we're presenting for lookup in our delegate methods
     [animation setValue:@(presenting) forKey:@"presenting"];
     
     animation.fillMode = kCAFillModeForwards;
     animation.removedOnCompletion = NO;
-    return animation;
+    
+    // Cast as non-null to mute static analysis warning as documented at
+    // https://clang-analyzer.llvm.org/faq.html#decide_nullability
+    return (CAAnimation * _Nonnull)animation;
 }
 
 - (void)layoutSubviews {