Handle unexpected (out-of-range) cases in switch statements for CompilerWarningLevel.HIGH targets

Summary: For `CompilerWarningLevel.HIGH` targets (except Instagram), let's address `switch` without `default` present

Reviewed By: aary

Differential Revision: D75460752

fbshipit-source-id: dd0a4594421580b745b7bb866efe4a86d3061d6d

Author: NSProgrammer

Source/IGListDiffKit/IGListDiff.mm

@@ -12,6 +12,7 @@
 #import <vector>
 
 #import "IGListCompatibility.h"
+#import "IGListMacros.h"
 
 #import "IGListIndexPathResultInternal.h"
 #import "IGListIndexSetResultInternal.h"
@@ -213,6 +214,8 @@ static id IGListDiffing(BOOL returnIndexPaths,
                         entry->updated = YES;
                     }
                     break;
+                default /* unexpected */:
+                    IGLK_UNEXPECTED_SWITCH_CASE_ABORT(IGListDiffOption, option);
             }
         }
         if (originalIndex != NSNotFound

Source/IGListDiffKit/IGListMacros.h

@@ -38,3 +38,20 @@
            ig_safe_block(__VA_ARGS__); \
        } \
    } while (NO)
+
+/*
+  E.g.
+  switch (direction) {
+    case UICollectionViewScrollDirectionHorizontal:
+        ...
+    case UICollectionViewScrollDirectionVertical:
+        ...
+    default:
+      IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, direction);
+  }
+*/
+#define IGLK_UNEXPECTED_SWITCH_CASE_ABORT(type, value) ({ \
+    type value__##__LINE__ = (value); \
+    fprintf(stderr, "Unexpected " #type " : %ld\n", (long)(value__##__LINE__)); \
+    abort(); \
+})

Source/IGListKit/IGListAdapter.m

@@ -261,6 +261,8 @@ - (void)scrollToObject:(id)object
                 case UICollectionViewScrollPositionCenteredVertically:
                     contentOffset.x = offset.min - contentInset.left;
                     break;
+                default: /* unexpected */
+                    IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollPosition, scrollPosition);
             }
             const CGFloat maxOffsetX = collectionView.contentSize.width - collectionView.frame.size.width + contentInset.right;
             const CGFloat minOffsetX = -contentInset.left;
@@ -286,6 +288,8 @@ - (void)scrollToObject:(id)object
                 case UICollectionViewScrollPositionCenteredHorizontally:
                     contentOffset.y = offset.min - contentInset.top;
                     break;
+                default: /* unexpected */
+                    IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollPosition, scrollPosition);
             }
             // If we don't call [collectionView layoutIfNeeded], the collectionView.contentSize does not get updated.
             // So lets use the layout object, since it should have been updated by now.
@@ -297,6 +301,8 @@ - (void)scrollToObject:(id)object
             contentOffset.y = MAX(contentOffset.y, minOffsetY);
             break;
         }
+        default: /* unexpected */
+            IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, scrollDirection);
     }
 
     [collectionView setContentOffset:contentOffset animated:animated];
@@ -318,6 +324,8 @@ - (CGFloat)offsetForFirstVisibleItemWithScrollDirection:(UICollectionViewScrollD
                 return self.collectionView.contentInset.left + self.collectionView.contentOffset.x - offset.min;
             case UICollectionViewScrollDirectionVertical:
                 return self.collectionView.contentInset.top + self.collectionView.contentOffset.y - offset.min;
+            default: /* unexpected */
+                IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, scrollDirection);
         }
     } else {
         return 0;
@@ -371,6 +379,8 @@ - (OffsetRange)_offsetRangeForIndexPath:(NSIndexPath *)indexPath
                 originMin = CGRectGetMinY(frame);
                 endMax = CGRectGetMaxY(frame);
                 break;
+            default: /* unexpected */
+                IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, scrollDirection);
         }
 
         // find the minimum origin value of all the layout attributes

Source/IGListKit/IGListCollectionViewLayout.mm

@@ -25,48 +25,62 @@ static CGFloat UIEdgeInsetsLeadingInsetInDirection(UIEdgeInsets insets, UICollec
     switch (direction) {
         case UICollectionViewScrollDirectionVertical: return insets.top;
         case UICollectionViewScrollDirectionHorizontal: return insets.left;
+        default: /* unexpected */
+            IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, direction);
     }
 }
 
 static CGFloat UIEdgeInsetsTrailingInsetInDirection(UIEdgeInsets insets, UICollectionViewScrollDirection direction) {
     switch (direction) {
         case UICollectionViewScrollDirectionVertical: return insets.bottom;
         case UICollectionViewScrollDirectionHorizontal: return insets.right;
+        default: /* unexpected */
+            IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, direction);
     }
 }
 
 static CGFloat CGPointGetCoordinateInDirection(CGPoint point, UICollectionViewScrollDirection direction) {
     switch (direction) {
         case UICollectionViewScrollDirectionVertical: return point.y;
         case UICollectionViewScrollDirectionHorizontal: return point.x;
+        default: /* unexpected */
+            IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, direction);
     }
 }
 
 static CGFloat CGRectGetLengthInDirection(CGRect rect, UICollectionViewScrollDirection direction) {
     switch (direction) {
         case UICollectionViewScrollDirectionVertical: return rect.size.height;
         case UICollectionViewScrollDirectionHorizontal: return rect.size.width;
+        default: /* unexpected */
+            IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, direction);
     }
 }
 
 static CGFloat CGRectGetMaxInDirection(CGRect rect, UICollectionViewScrollDirection direction) {
     switch (direction) {
         case UICollectionViewScrollDirectionVertical: return CGRectGetMaxY(rect);
         case UICollectionViewScrollDirectionHorizontal: return CGRectGetMaxX(rect);
+        default: /* unexpected */
+            IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, direction);
     }
 }
 
 static CGFloat CGRectGetMinInDirection(CGRect rect, UICollectionViewScrollDirection direction) {
     switch (direction) {
         case UICollectionViewScrollDirectionVertical: return CGRectGetMinY(rect);
         case UICollectionViewScrollDirectionHorizontal: return CGRectGetMinX(rect);
+        default: /* unexpected */
+            IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, direction);
     }
 }
 
 static CGFloat CGSizeGetLengthInDirection(CGSize size, UICollectionViewScrollDirection direction) {
     switch (direction) {
         case UICollectionViewScrollDirectionVertical: return size.height;
         case UICollectionViewScrollDirectionHorizontal: return size.width;
+        default: /* unexpected */
+            IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, direction);
     }
 }
 
@@ -77,9 +91,11 @@ static CGFloat CGSizeGetLengthInDirection(CGSize size, UICollectionViewScrollDir
 static NSInteger IGListMergeMinimumInvalidatedSection(NSInteger section, NSInteger otherSection) {
     if (section == NSNotFound && otherSection == NSNotFound) {
         return NSNotFound;
-    } else if (section == NSNotFound) {
+    }
+    if (section == NSNotFound) {
         return otherSection;
-    } else if (otherSection == NSNotFound) {
+    }
+    if (otherSection == NSNotFound) {
         return section;
     }
 
@@ -331,6 +347,8 @@ - (UICollectionViewLayoutAttributes *)layoutAttributesForSupplementaryViewOfKind
                 case UICollectionViewScrollDirectionHorizontal:
                     frame.origin.x = offset;
                     break;
+                default: /* unexpected */
+                    IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, self.scrollDirection);
             }
         }
     } else if ([elementKind isEqualToString:UICollectionElementKindSectionFooter]) {
@@ -370,6 +388,8 @@ - (CGSize)collectionViewContentSize {
         case UICollectionViewScrollDirectionHorizontal:
             return CGSizeMake(CGRectGetMaxX(section.bounds) + section.insets.right,
                               CGRectGetHeight(collectionView.bounds) - contentInset.top - contentInset.bottom);
+        default: /* unexpected */
+            IGLK_UNEXPECTED_SWITCH_CASE_ABORT(UICollectionViewScrollDirection, self.scrollDirection);
     }
 }
 

Source/IGListKit/Internal/IGListAdapterUpdater+DebugDescription.m

@@ -43,6 +43,8 @@ @implementation IGListAdapterUpdater (DebugDescription)
         case IGListBatchUpdateStateExecutingBatchUpdateBlock:
             stateString = @"Executing batch update block";
             break;
+        default: /* unknown */
+            IGLK_UNEXPECTED_SWITCH_CASE_ABORT(IGListBatchUpdateState, state);
     }
     [debug addObject:[NSString stringWithFormat:@"State: %@", stateString]];
 

Source/IGListKit/Internal/IGListUpdateTransactionBuilder.m

@@ -179,6 +179,8 @@ - (void)addChangesFromBuilder:(IGListUpdateTransactionBuilder *)builder {
                                                                  itemUpdateBlocks:self.itemUpdateBlocks
                                                                  completionBlocks:self.completionBlocks];
         }
+        default: /* unexpected */
+            IGLK_UNEXPECTED_SWITCH_CASE_ABORT(IGListUpdateTransactionBuilderMode, self.mode);
     }
 }