wip

Author: hvitved

unified/ql/lib/codeql/unified/internal/typeinference/TypeMention.qll

@@ -60,7 +60,7 @@ abstract private class TypeMentionImpl extends AstNode {
   bindingset[this, qualifier]
   pragma[inline_late]
   predicate isValidParentType(TypeMention qualifier) {
-    this.isValidParentType0(qualifier.getClassLikeDeclaration())
+    this.isValidParentType0(qualifier.getClassLikeDeclaration().getEnclosingClassResolved*())
   }
 
   /**
@@ -128,17 +128,35 @@ abstract private class ExprTypeMentionImpl extends TypeMentionImpl, Expr {
 
   abstract Type getTypeAtImpl(TypePath path);
 
+  pragma[nomagic]
+  private ClassLikeDeclaration getQualifierTypeAt(TypePath path) {
+    result =
+      this.getParentQualifier().getTypeAt(path).(ClassLikeDeclarationType).getClassLikeDeclaration()
+  }
+
+  pragma[nomagic]
+  private predicate isNestedClass(
+    ClassLikeDeclaration cls, ParentTypeParameterType tp, ClassLikeDeclaration parent
+  ) {
+    cls = this.getClassLikeDeclaration() and
+    tp = TParentTypeParameterType(cls) and
+    parent = tp.getParent()
+  }
+
   final override Type getTypeAt(TypePath path) {
     // recursion guard to check that `getType` does not recursively depend on `getTypeAt`
     (exists(this.getType()) implies any()) and
     result = this.getTypeAtImpl(path)
     or
     // A mention of a nested type with an explicit qualifier
-    exists(TypeMention qualifier, ClassLikeDeclaration cls, TypePath suffix |
+    exists(
+      TypeMention qualifier, ClassLikeDeclaration cls, ParentTypeParameterType tp, TypePath prefix,
+      TypePath suffix
+    |
       qualifier = this.getParentQualifier() and
-      cls = this.getClassLikeDeclaration() and
-      path = TypePath::cons(TParentTypeParameterType(cls), suffix) and
-      result = qualifier.getTypeAt(suffix)
+      this.isNestedClass(cls, tp, this.getQualifierTypeAt(prefix)) and
+      path = TypePath::cons(tp, suffix) and
+      result = qualifier.getTypeAt(prefix.appendInverse(suffix))
     )
     or
     // A mention of a nested type without an explicit qualifier implicitly mentions

unified/ql/test/library-tests/type-inference/nested_types.swift

@@ -103,6 +103,13 @@ class Outer<TOuter> {
         let outer = x.getOuter()  // $ target=Outer.Inner.getOuter type=outer:String
         let inner = x.getInner()  // $ target=Outer.Inner.getInner type=inner:Int
     }
+
+    typealias Pair = (Inner<Int>, Inner<Int>)
+
+    func f3(p: Pair) {
+        let outer = p.0.getOuter()  // $ target=Outer.Inner.getOuter field=Tuple2.0 $ MISSING: type=outer:TOuter
+        let inner = p.0.getInner()  // $ target=Outer.Inner.getInner field=Tuple2.0 type=inner:Int
+    }
 }
 
 func extractInner<Ta, Tb>(_ inner: Outer<Ta>.Inner<Tb>) -> Tb {
@@ -245,6 +252,6 @@ func f(_ x: H.InnerAlias<Bool>, _ y: H2.InnerAlias<Bool>) {
 typealias G<A> = Outer<A>.Holder
 
 func f(_ x: G<String>.InnerAlias<Bool>) {
-    let outer = x.getOuter()  // $ target=Outer.Inner.getOuter $ MISSING: type=outer:String
+    let outer = x.getOuter()  // $ target=Outer.Inner.getOuter type=outer:String
     let inner = x.getInner()  // $ target=Outer.Inner.getInner type=inner:Bool
 }