Fix Alignment of Hashed Structs (TextureGroup#287)

* Fix alignment of ASImageNodeContentsKey struct to fix hashing * Change the change log by logging a change * Add the world's stupidest explicit cast * Actually its simpler
AtomTickets · Apr 25, 2018 · d529763 · d529763
1 parent 754caea
commit d529763
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Showing 5 changed files with 16 additions and 2 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -24,4 +24,4 @@
 - [Layout] Extract layout implementation code into it's own subcategories [Michael Schneider] (https://github.com/maicki)[#272](https://github.com/TextureGroup/Texture/pull/272)
 - [Fix] Fix a potential crash when cell nodes that need layout are deleted during the same runloop.  [Adlai Holler](https://github.com/Adlai-Holler) [#279](https://github.com/TextureGroup/Texture/pull/279)
 - [Batch fetching] Add ASBatchFetchingDelegate that takes scroll velocity and remaining time into account [Huy Nguyen](https://github.com/nguyenhuy) [#281](https://github.com/TextureGroup/Texture/pull/281)
-
+- [Fix] Fix a major regression in our image node contents caching. [Adlai Holler](https://github.com/Adlai-Holler) [#287](https://github.com/TextureGroup/Texture/pull/287)
diff --git a/Source/ASImageNode.mm b/Source/ASImageNode.mm
@@ -113,15 +113,18 @@ - (BOOL)isEqual:(id)object
 
 - (NSUInteger)hash
 {
+#pragma clang diagnostic push
+#pragma clang diagnostic warning "-Wpadded"
   struct {
     NSUInteger imageHash;
     CGSize backingSize;
     CGRect imageDrawRect;
-    BOOL isOpaque;
+    NSInteger isOpaque;
     NSUInteger backgroundColorHash;
     void *willDisplayNodeContentWithRenderingContext;
     void *didDisplayNodeContentWithRenderingContext;
     void *imageModificationBlock;
+#pragma clang diagnostic pop
   } data = {
     _image.hash,
     _backingSize,

diff --git a/Source/ASTextNode.mm b/Source/ASTextNode.mm
@@ -64,9 +64,12 @@ @implementation ASTextNodeRendererKey
 
 - (NSUInteger)hash
 {
+#pragma clang diagnostic push
+#pragma clang diagnostic warning "-Wpadded"
   struct {
     size_t attributesHash;
     CGSize constrainedSize;
+#pragma clang diagnostic pop
   } data = {
     _attributes.hash(),
     _constrainedSize

diff --git a/Source/Private/ASHashing.h b/Source/Private/ASHashing.h
@@ -34,6 +34,11 @@ ASDISPLAYNODE_EXTERN_C_BEGIN
  *    _bounds.size
  *  };
  *  return ASHashBytes(&data, sizeof(data));
+ *
+ * @warning: If a struct has padding, any fields that are intiailized in {} 
+ *   will have garbage data for their padding, which will break this hash! Either
+ *   use `pragma clang diagnostic warning "-Wpadded"` around your struct definition
+ *   or manually initialize the fields of your struct (`myStruct.x = 7;` etc).
  */
 NSUInteger ASHashBytes(void *bytes, size_t length);
 

diff --git a/Source/TextKit/ASTextKitAttributes.mm b/Source/TextKit/ASTextKitAttributes.mm
@@ -24,6 +24,8 @@
 
 size_t ASTextKitAttributes::hash() const
 {
+#pragma clang diagnostic push
+#pragma clang diagnostic warning "-Wpadded"
   struct {
     NSUInteger attrStringHash;
     NSUInteger truncationStringHash;
@@ -35,6 +37,7 @@
     NSUInteger shadowColorHash;
     CGFloat shadowOpacity;
     CGFloat shadowRadius;
+#pragma clang diagnostic pop
   } data = {
     [attributedString hash],
     [truncationAttributedString hash],