Do not allow comparing objects of different types

smalltalksrc/VMMaker/StackInterpreter.class.st

@@ -10889,7 +10889,6 @@ StackInterpreter >> primitiveCompareBytes [
 
 	<export: true>
 	| arg1 arg2 len1 len2 result boolean |
-
 	argumentCount < 1 ifTrue: [ ^ self primitiveFail ].
 
 	arg1 := self stackValue: 1.
@@ -10898,13 +10897,18 @@ StackInterpreter >> primitiveCompareBytes [
 	"Quick identity test to avoid checking object contents when they are the same one\"
 	arg1 = arg2 ifTrue: [
 		^ self pop: 2 thenPush: objectMemory trueObject ].
-
+
+	"This primitive only works for objects of the same type e.g., both byte indexable.
+	This prevents comparison of byte arrays with word arrays"
+	(objectMemory instSpecOfClass: (objectMemory fetchClassOf: arg1)) ~= (objectMemory instSpecOfClass: (objectMemory fetchClassOf: arg2))
+		ifTrue: [
+			self primitiveFail.
+			^ self ].
+
 	"This primitive only works for bytes and words objects.
 	The check below does not even let pass forwarders.
-	Below, we assume that the two compared objects are indexable and can be compared."
-	((objectMemory isWordsOrBytes: arg1) and: [
-		 objectMemory isWordsOrBytes: arg2 ]) ifFalse: [
-		^ self primitiveFail ].
+	Since we know by the check before that both arguments are of the same type, we only need to check one of them here"
+	(objectMemory isWordsOrBytes: arg1) ifFalse: [ ^ self primitiveFail ].
 
 	"Two arrays of different lenght can never be equal"
 	len1 := objectMemory byteSizeOf: arg1.

smalltalksrc/VMMakerTests/VMPrimitiveTest.class.st

@@ -1388,9 +1388,11 @@ VMPrimitiveTest >> testPrimitiveCompareBytesWithLastDifferentValue [
 { #category : #'tests - primitiveCompareBytes' }
 VMPrimitiveTest >> testPrimitiveCompareBytesWithNonByteArgument [
 
-	| array1 size |
+	| array1 size nilClass |
 	size := 2.
 	array1 := self new8BitIndexableOfSize: size.
+	nilClass := self newClassInOldSpaceWithSlots: 0 instSpec: memory zeroSlotsNonIndexablePointerFormat.
+	memory setClassIndexOf: memory nilObject to: (memory ensureBehaviorHash: nilClass).
 
 	1 to: size do: [ :i |
 	memory storeByte: i - 1 ofObject: array1 withValue: 0 ].
@@ -1407,9 +1409,12 @@ VMPrimitiveTest >> testPrimitiveCompareBytesWithNonByteArgument [
 { #category : #'tests - primitiveCompareBytes' }
 VMPrimitiveTest >> testPrimitiveCompareBytesWithNonByteReceiver [
 
-	| array1 size |
+	| array1 size nilClass |
 	size := 2.
 	array1 := self new8BitIndexableOfSize: size.
+	nilClass := self newClassInOldSpaceWithSlots: 0 instSpec: memory zeroSlotsNonIndexablePointerFormat.
+	memory setClassIndexOf: memory nilObject to: (memory ensureBehaviorHash: nilClass).
+
 
 	1 to: size do: [ :i |
 	memory storeByte: i - 1 ofObject: array1 withValue: 0 ].
@@ -1426,9 +1431,12 @@ VMPrimitiveTest >> testPrimitiveCompareBytesWithNonByteReceiver [
 { #category : #'tests - primitiveCompareBytes' }
 VMPrimitiveTest >> testPrimitiveCompareBytesWithNonByteReceiverShouldLeaveTheSameStack [
 
-	| array1 size |
+	| array1 size nilClass |
 	size := 2.
 	array1 := self new8BitIndexableOfSize: size.
+	nilClass := self newClassInOldSpaceWithSlots: 0 instSpec: memory zeroSlotsNonIndexablePointerFormat.
+	memory setClassIndexOf: memory nilObject to: (memory ensureBehaviorHash: nilClass).
+
 
 	1 to: size do: [ :i |
 	memory storeByte: i - 1 ofObject: array1 withValue: 0 ].
@@ -1464,6 +1472,41 @@ VMPrimitiveTest >> testPrimitiveCompareBytesWithSize [
 	self assert: interpreter stackTop equals: memory trueObject
 ]
 
+{ #category : #'tests - primitiveCompareBytes' }
+VMPrimitiveTest >> testPrimitiveCompareBytesWithWordArgument [
+
+	| array1 array2 size |
+	size := 1.
+	"Both will be 8 bytes long"
+	array1 := self new8BitIndexableOfSize: size * 8.
+	array2 := self new64BitIndexableOfSize: size.
+
+	interpreter push: array1.
+	interpreter push: array2.
+
+	interpreter argumentCount: 1.
+	interpreter primitiveCompareBytes.
+
+	"Should fail because they don't have the same type"
+	self assert: interpreter failed
+]
+
+{ #category : #'tests - primitiveCompareBytes' }
+VMPrimitiveTest >> testPrimitiveCompareWordsEmpty [
+
+	| array1 array2 |
+	array1 := self new64BitIndexableOfSize: 0.
+	array2 := self new64BitIndexableOfSize: 0.
+
+	interpreter push: array1.
+	interpreter push: array2.
+
+	interpreter argumentCount: 1.
+	interpreter primitiveCompareBytes.
+
+	self assert: interpreter stackTop equals: memory trueObject
+]
+
 { #category : #'tests - primitiveDiv' }
 VMPrimitiveTest >> testPrimitiveDiv [
 

smalltalksrc/VMMakerTests/VMSpurMemoryManagerTest.class.st

@@ -424,14 +424,17 @@ VMSpurMemoryManagerTest >> newArrayWithSlots: slots classIndex: anIndex [
 { #category : #helpers }
 VMSpurMemoryManagerTest >> newBitIndexableOfSize: aSize bytesPerSlot: bytesPerSlot format: format [
 
-	| padding numberOfWordSizeSlots desiredByteSize |
+	| padding numberOfWordSizeSlots desiredByteSize theClass classIndex |
+	theClass := self newClassInOldSpaceWithSlots: 0 instSpec: format.
+	classIndex := memory ensureBehaviorHash: theClass.
+
 	desiredByteSize := aSize * bytesPerSlot roundUpTo: self wordSize.
 	numberOfWordSizeSlots := desiredByteSize / self wordSize.
 	padding := desiredByteSize / bytesPerSlot - aSize.
 	^ memory
 		  allocateNewSpaceSlots: numberOfWordSizeSlots
 		  format: format + padding
-		  classIndex: self nextOrdinaryClassIndex
+		  classIndex: classIndex
 ]
 
 { #category : #asd }