Swift: Unify ArrayContent and CollectionContent

swift/ql/lib/change-notes/2023-09-13-array-content-unification.md

@@ -0,0 +1,5 @@
+---
+category: deprecated
+---
+
+* The `ArrayContent` type in the data flow library has been deprecated and made an alias for the `CollectionContent` type, to better reflect the hierarchy of the Swift standard library. Uses of `ArrayElement` in model files will be interpreted as referring to `CollectionContent`.

swift/ql/lib/codeql/swift/dataflow/ExternalFlow.qll

@@ -497,8 +497,9 @@ predicate parseContent(AccessPathToken component, Content content) {
   or
   parseEnum(component, content)
   or
+  // map legacy "ArrayElement" specification components to `CollectionContent`
   component.getName() = "ArrayElement" and
-  content instanceof Content::ArrayContent
+  content instanceof Content::CollectionContent
   or
   component.getName() = "CollectionElement" and
   content instanceof Content::CollectionContent

swift/ql/lib/codeql/swift/dataflow/internal/DataFlowPrivate.qll

@@ -297,7 +297,6 @@ private module Cached {
     TFieldContent(FieldDecl f) or
     TTupleContent(int index) { exists(any(TupleExpr te).getElement(index)) } or
     TEnumContent(ParamDecl f) { exists(EnumElementDecl d | d.getAParam() = f) } or
-    TArrayContent() or
     TCollectionContent()
 }
 
@@ -842,7 +841,7 @@ predicate storeStep(Node node1, ContentSet c, Node node2) {
   exists(ArrayExpr arr |
     node1.asExpr() = arr.getAnElement() and
     node2.asExpr() = arr and
-    c.isSingleton(any(Content::ArrayContent ac))
+    c.isSingleton(any(Content::CollectionContent ac))
   )
   or
   // array assignment `a[n] = x`
@@ -851,7 +850,7 @@ predicate storeStep(Node node1, ContentSet c, Node node2) {
     node2.(PostUpdateNode).getPreUpdateNode().asExpr() = subscript.getBase() and
     subscript = assign.getDest() and
     subscript.getBase().getType() instanceof ArrayType and
-    c.isSingleton(any(Content::ArrayContent ac))
+    c.isSingleton(any(Content::CollectionContent ac))
   )
   or
   // creation of an optional via implicit wrapping keypath component
@@ -948,7 +947,7 @@ predicate readStep(Node node1, ContentSet c, Node node2) {
     (
       c.isSingleton(any(Content::FieldContent ct | ct.getField() = component.getDeclRef()))
       or
-      c.isSingleton(any(Content::ArrayContent ac)) and
+      c.isSingleton(any(Content::CollectionContent ac)) and
       component.isSubscript()
       or
       c instanceof OptionalSomeContentSet and
@@ -971,12 +970,7 @@ predicate readStep(Node node1, ContentSet c, Node node2) {
   exists(SubscriptExpr subscript |
     subscript.getBase() = node1.asExpr() and
     subscript = node2.asExpr() and
-    (
-      subscript.getBase().getType() instanceof ArrayType and
-      c.isSingleton(any(Content::ArrayContent ac))
-      or
-      c.isSingleton(any(Content::CollectionContent ac))
-    )
+    c.isSingleton(any(Content::CollectionContent ac))
   )
   or
   // read of a dictionary value via subscript operator
@@ -1098,9 +1092,7 @@ class DataFlowExpr = Expr;
  * Holds if access paths with `c` at their head always should be tracked at high
  * precision. This disables adaptive access path precision for such access paths.
  */
-predicate forceHighPrecision(Content c) {
-  c instanceof Content::ArrayContent or c instanceof Content::CollectionContent
-}
+predicate forceHighPrecision(Content c) { c instanceof Content::CollectionContent }
 
 /**
  * Holds if the node `n` is unreachable when the call context is `call`.

swift/ql/lib/codeql/swift/dataflow/internal/DataFlowPublic.qll

@@ -220,11 +220,6 @@ module Content {
     override string toString() { result = this.getSignature() }
   }
 
-  /** An element of an array at an unknown index */
-  class ArrayContent extends Content, TArrayContent {
-    override string toString() { result = "Array element" }
-  }
-
   /**
    * An element of a collection. This is a broad class including:
    *  - elements of collections, such as `Set<Element>`.
@@ -234,6 +229,11 @@ module Content {
   class CollectionContent extends Content, TCollectionContent {
     override string toString() { result = "Collection element" }
   }
+
+  /**
+   * DEPRECATED: An element of a collection. This is an alias for the general CollectionContent.
+   */
+  deprecated class ArrayContent = CollectionContent;
 }
 
 /**

swift/ql/lib/codeql/swift/dataflow/internal/FlowSummaryImplSpecific.qll

@@ -129,11 +129,6 @@ private string getContentSpecific(ContentSet cs) {
     result = "EnumElement[" + c.getSignature() + "]"
   )
   or
-  exists(Content::ArrayContent c |
-    cs.isSingleton(c) and
-    result = "ArrayElement"
-  )
-  or
   exists(Content::CollectionContent c |
     cs.isSingleton(c) and
     result = "CollectionElement"

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/Array.qll

@@ -19,20 +19,20 @@ private class ArraySummaries extends SummaryModelCsv {
   override predicate row(string row) {
     row =
       [
-        ";Array;true;insert(_:at:);;;Argument[0];Argument[-1].ArrayElement;value",
+        ";Array;true;insert(_:at:);;;Argument[0];Argument[-1].CollectionElement;value",
         ";Array;true;insert(_:at:);;;Argument[1];Argument[-1];taint",
         ";Array;true;withUnsafeBufferPointer(_:);;;Argument[-1];Argument[0].Parameter[0].CollectionElement;taint",
-        ";Array;true;withUnsafeBufferPointer(_:);;;Argument[-1].ArrayElement;Argument[0].Parameter[0].CollectionElement;value",
+        ";Array;true;withUnsafeBufferPointer(_:);;;Argument[-1].CollectionElement;Argument[0].Parameter[0].CollectionElement;value",
         ";Array;true;withUnsafeBufferPointer(_:);;;Argument[0].ReturnValue;ReturnValue;value",
         ";Array;true;withUnsafeMutableBufferPointer(_:);;;Argument[-1];Argument[0].Parameter[0].CollectionElement;taint",
-        ";Array;true;withUnsafeMutableBufferPointer(_:);;;Argument[-1].ArrayElement;Argument[0].Parameter[0].CollectionElement;value",
+        ";Array;true;withUnsafeMutableBufferPointer(_:);;;Argument[-1].CollectionElement;Argument[0].Parameter[0].CollectionElement;value",
         ";Array;true;withUnsafeMutableBufferPointer(_:);;;Argument[0].Parameter[0].CollectionElement;Argument[-1].CollectionElement;value",
         ";Array;true;withUnsafeMutableBufferPointer(_:);;;Argument[0].ReturnValue;ReturnValue;value",
         ";Array;true;withUnsafeBytes(_:);;;Argument[-1];Argument[0].Parameter[0].CollectionElement;taint",
-        ";Array;true;withUnsafeBytes(_:);;;Argument[-1].ArrayElement;Argument[0].Parameter[0].CollectionElement;taint",
+        ";Array;true;withUnsafeBytes(_:);;;Argument[-1].CollectionElement;Argument[0].Parameter[0].CollectionElement;taint",
         ";Array;true;withUnsafeBytes(_:);;;Argument[0].ReturnValue;ReturnValue;value",
         ";Array;true;withUnsafeMutableBytes(_:);;;Argument[-1];Argument[0].Parameter[0].CollectionElement;taint",
-        ";Array;true;withUnsafeMutableBytes(_:);;;Argument[-1].ArrayElement;Argument[0].Parameter[0].CollectionElement;taint",
+        ";Array;true;withUnsafeMutableBytes(_:);;;Argument[-1].CollectionElement;Argument[0].Parameter[0].CollectionElement;taint",
         ";Array;true;withUnsafeMutableBytes(_:);;;Argument[0].Parameter[0].CollectionElement;Argument[-1].CollectionElement;value",
         ";Array;true;withUnsafeMutableBytes(_:);;;Argument[0].ReturnValue;ReturnValue;value",
         ";ContiguousArray;true;withUnsafeBufferPointer(_:);;;Argument[-1];Argument[0].Parameter[0].CollectionElement;taint",

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/Collection.qll

@@ -27,7 +27,6 @@ private class CollectionSummaries extends SummaryModelCsv {
         ";Collection;true;removeFirst();;;Argument[-1];ReturnValue;taint",
         ";Collection;true;popFirst();;;Argument[-1];ReturnValue;taint",
         ";Collection;true;randomElement();;;Argument[-1].CollectionElement;ReturnValue.OptionalSome;value",
-        ";Collection;true;randomElement();;;Argument[-1].ArrayElement;ReturnValue.OptionalSome;value",
         ";RangeReplaceableCollection;true;append(_:);;;Argument[0];Argument[-1];taint",
         ";RangeReplaceableCollection;true;append(contentsOf:);;;Argument[0];Argument[-1];taint",
         ";RangeReplaceableCollection;true;remove(at:);;;Argument[-1];ReturnValue;taint",
@@ -38,7 +37,6 @@ private class CollectionSummaries extends SummaryModelCsv {
         ";BidirectionalCollection;true;last(where:);;;Argument[-1];ReturnValue;taint",
         ";BidirectionalCollection;true;popLast();;;Argument[-1];ReturnValue;taint",
         ";MutableCollection;true;withContiguousMutableStorageIfAvailable(_:);;;Argument[-1];Argument[0].Parameter[0].CollectionElement;taint",
-        ";MutableCollection;true;withContiguousMutableStorageIfAvailable(_:);;;Argument[-1].ArrayElement;Argument[0].Parameter[0].CollectionElement;value",
         ";MutableCollection;true;withContiguousMutableStorageIfAvailable(_:);;;Argument[-1].CollectionElement;Argument[0].Parameter[0].CollectionElement;value",
         ";MutableCollection;true;withContiguousMutableStorageIfAvailable(_:);;;Argument[0].Parameter[0].CollectionElement;Argument[-1].CollectionElement;value",
         ";MutableCollection;true;withContiguousMutableStorageIfAvailable(_:);;;Argument[0].ReturnValue;ReturnValue.OptionalSome;value",

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/Sequence.qll

@@ -26,7 +26,6 @@ private class SequenceSummaries extends SummaryModelCsv {
         ";Sequence;true;joined(separator:);;;Argument[-1..0];ReturnValue;taint",
         ";Sequence;true;first(where:);;;Argument[-1];ReturnValue;taint",
         ";Sequence;true;withContiguousStorageIfAvailable(_:);;;Argument[-1];Argument[0].Parameter[0].CollectionElement;taint",
-        ";Sequence;true;withContiguousStorageIfAvailable(_:);;;Argument[-1].ArrayElement;Argument[0].Parameter[0].CollectionElement;value",
         ";Sequence;true;withContiguousStorageIfAvailable(_:);;;Argument[-1].CollectionElement;Argument[0].Parameter[0].CollectionElement;value",
         ";Sequence;true;withContiguousStorageIfAvailable(_:);;;Argument[0].ReturnValue;ReturnValue.OptionalSome;value",
       ]

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/Set.qll

@@ -14,7 +14,7 @@ private class SetSummaries extends SummaryModelCsv {
         ";Set;true;insert(_:);;;Argument[-1].CollectionElement;ReturnValue.TupleElement[1];value",
         ";Set;true;insert(_:);;;Argument[0];Argument[-1].CollectionElement;value",
         ";Set;true;insert(_:);;;Argument[0];ReturnValue.TupleElement[1];value",
-        ";Set;true;init(_:);;;Argument[0].ArrayElement;ReturnValue.CollectionElement;value"
+        ";Set;true;init(_:);;;Argument[0].CollectionElement;ReturnValue.CollectionElement;value"
       ]
   }
 }

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/String.qll

@@ -34,7 +34,6 @@ private class StringSummaries extends SummaryModelCsv {
     row =
       [
         ";StringProtocol;true;init(cString:);;;Argument[0];ReturnValue;taint",
-        ";StringProtocol;true;init(cString:);;;Argument[0].ArrayElement;ReturnValue;taint",
         ";StringProtocol;true;init(cString:);;;Argument[0].CollectionElement;ReturnValue;taint",
         ";StringProtocol;true;init(decoding:as:);;;Argument[0];ReturnValue;taint",
         ";StringProtocol;true;init(decodingCString:as:);;;Argument[0].OptionalSome.CollectionElement;ReturnValue.OptionalSome.TupleElement[0];taint",
@@ -46,12 +45,12 @@ private class StringSummaries extends SummaryModelCsv {
         ";StringProtocol;true;cString(using:);;;Argument[-1];ReturnValue;taint",
         ";StringProtocol;true;capitalized(with:);;;Argument[-1];ReturnValue;taint",
         ";StringProtocol;true;completePath(into:caseSensitive:matchesInto:filterTypes:);;;Argument[-1];Argument[0].OptionalSome.CollectionElement;taint",
-        ";StringProtocol;true;completePath(into:caseSensitive:matchesInto:filterTypes:);;;Argument[-1];Argument[2].OptionalSome.CollectionElement.ArrayElement;taint",
+        ";StringProtocol;true;completePath(into:caseSensitive:matchesInto:filterTypes:);;;Argument[-1];Argument[2].OptionalSome.CollectionElement.CollectionElement;taint",
         ";StringProtocol;true;components(separatedBy:);;;Argument[-1];ReturnValue;taint",
         ";StringProtocol;true;data(using:allowLossyConversion:);;;Argument[-1];ReturnValue;taint",
         ";StringProtocol;true;folding(options:locale:);;;Argument[-1];ReturnValue;taint",
-        ";StringProtocol;true;getBytes(_:maxLength:usedLength:encoding:options:range:remaining:);;;Argument[-1];Argument[0].ArrayElement;taint",
-        ";StringProtocol;true;getCString(_:maxLength:encoding:);;;Argument[-1];Argument[0].ArrayElement;taint",
+        ";StringProtocol;true;getBytes(_:maxLength:usedLength:encoding:options:range:remaining:);;;Argument[-1];Argument[0].CollectionElement;taint",
+        ";StringProtocol;true;getCString(_:maxLength:encoding:);;;Argument[-1];Argument[0].CollectionElement;taint",
         ";StringProtocol;true;lowercased();;;Argument[-1];ReturnValue;taint",
         ";StringProtocol;true;lowercased(with:);;;Argument[-1];ReturnValue;taint",
         ";StringProtocol;true;padding(toLength:withPad:startingAt:);;;Argument[-1];ReturnValue;taint",
@@ -74,20 +73,18 @@ private class StringSummaries extends SummaryModelCsv {
         ";String;true;init(repeating:count:);;;Argument[0];ReturnValue;taint",
         ";String;true;init(data:encoding:);;;Argument[0];ReturnValue.OptionalSome;taint",
         ";String;true;init(validatingUTF8:);;;Argument[0];ReturnValue.OptionalSome;taint",
-        ";String;true;init(validatingUTF8:);;;Argument[0].ArrayElement;ReturnValue.OptionalSome;taint",
         ";String;true;init(validatingUTF8:);;;Argument[0].CollectionElement;ReturnValue.OptionalSome;taint",
         ";String;true;init(utf16CodeUnits:count:);;;Argument[0].CollectionElement;ReturnValue;taint",
         ";String;true;init(utf16CodeUnitsNoCopy:count:freeWhenDone:);;;Argument[0].CollectionElement;ReturnValue;taint",
         ";String;true;init(format:_:);;;Argument[0];ReturnValue;taint",
-        ";String;true;init(format:_:);;;Argument[1].ArrayElement;ReturnValue;taint",
+        ";String;true;init(format:_:);;;Argument[1].CollectionElement;ReturnValue;taint",
         ";String;true;init(format:arguments:);;;Argument[0];ReturnValue;taint",
-        ";String;true;init(format:arguments:);;;Argument[1].ArrayElement;ReturnValue;taint",
+        ";String;true;init(format:arguments:);;;Argument[1].CollectionElement;ReturnValue;taint",
         ";String;true;init(format:locale:_:);;;Argument[0];ReturnValue;taint",
-        ";String;true;init(format:locale:_:);;;Argument[2].ArrayElement;ReturnValue;taint",
+        ";String;true;init(format:locale:_:);;;Argument[2].CollectionElement;ReturnValue;taint",
         ";String;true;init(format:locale:arguments:);;;Argument[0];ReturnValue;taint",
-        ";String;true;init(format:locale:arguments:);;;Argument[2].ArrayElement;ReturnValue;taint",
+        ";String;true;init(format:locale:arguments:);;;Argument[2].CollectionElement;ReturnValue;taint",
         ";String;true;init(_:radix:uppercase:);;;Argument[0];ReturnValue;taint",
-        ";String;true;init(bytes:encoding:);;;Argument[0].ArrayElement;ReturnValue.OptionalSome;taint",
         ";String;true;init(bytes:encoding:);;;Argument[0].CollectionElement;ReturnValue.OptionalSome;taint",
         ";String;true;init(bytesNoCopy:length:encoding:freeWhenDone:);;;Argument[0].CollectionElement;ReturnValue.OptionalSome;taint",
         ";String;true;init(describing:);;;Argument[0];ReturnValue;taint",
@@ -104,20 +101,16 @@ private class StringSummaries extends SummaryModelCsv {
         ";String;true;init(unicodeScalarLiteral:);;;Argument[0];ReturnValue;taint",
         ";String;true;init(extendedGraphemeClusterLiteral:);;;Argument[0];ReturnValue;taint",
         ";String;true;init(cString:encoding:);;;Argument[0];ReturnValue.OptionalSome;taint",
-        ";String;true;init(cString:encoding:);;;Argument[0].ArrayElement;ReturnValue.OptionalSome;taint",
         ";String;true;init(cString:encoding:);;;Argument[0].CollectionElement;ReturnValue.OptionalSome;taint",
         ";String;true;init(platformString:);;;Argument[0];ReturnValue;taint",
-        ";String;true;init(platformString:);;;Argument[0].ArrayElement;ReturnValue;taint",
         ";String;true;init(platformString:);;;Argument[0].CollectionElement;ReturnValue;taint",
         ";String;true;init(utf8String:);;;Argument[0];ReturnValue.OptionalSome;taint",
-        ";String;true;init(utf8String:);;;Argument[0].ArrayElement;ReturnValue.OptionalSome;taint",
         ";String;true;init(utf8String:);;;Argument[0].CollectionElement;ReturnValue.OptionalSome;taint",
         ";String;true;init(validating:);;;Argument[0];ReturnValue.OptionalSome;taint",
         ";String;true;init(validatingPlatformString:);;;Argument[0];ReturnValue.OptionalSome;taint",
-        ";String;true;init(validatingPlatformString:);;;Argument[0].ArrayElement;ReturnValue.OptionalSome;taint",
         ";String;true;init(validatingPlatformString:);;;Argument[0].CollectionElement;ReturnValue.OptionalSome;taint",
         ";String;true;localizedStringWithFormat(_:_:);;;Argument[0];ReturnValue;taint",
-        ";String;true;localizedStringWithFormat(_:_:);;;Argument[1].ArrayContent;ReturnValue;taint",
+        ";String;true;localizedStringWithFormat(_:_:);;;Argument[1].CollectionElement;ReturnValue;taint",
         ";String;true;write(_:);;;Argument[0];Argument[-1];taint",
         ";String;true;write(to:);;;Argument[-1];Argument[0];taint",
         ";String;true;insert(contentsOf:at:);;;Argument[0];Argument[-1];taint",

swift/ql/lib/codeql/swift/security/UnsafeJsEvalQuery.qll

@@ -30,10 +30,7 @@ module UnsafeJsEvalConfig implements DataFlow::ConfigSig {
       or
       isAdditionalFlowStep(node, _)
     ) and
-    (
-      c.getAReadContent() instanceof DataFlow::Content::ArrayContent or
-      c.getAReadContent() instanceof DataFlow::Content::CollectionContent
-    )
+    c.getAReadContent() instanceof DataFlow::Content::CollectionContent
   }
 }