wip2

Author: hvitved

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

@@ -165,6 +165,8 @@ class ClosureParameterPseudoType extends PseudoType, TClosureParameterPseudoType
 
 /** A type parameter. */
 abstract class TypeParameter extends TypeImpl {
+  abstract AstNode getScope();
+
   override TypeParameter getPositionalTypeParameter(int i) { none() }
 
   abstract AstNode getDeclaringItem();
@@ -187,6 +189,12 @@ class TypeParameterType extends TypeParameter, TTypeParameterType {
 
   Unified::TypeParameter getTypeParameter() { result = typeParam }
 
+  override AstNode getScope() {
+    result = typeParam.getParent()
+    or
+    result.(ClassLikeDeclaration).resolve().getEnclosingClassResolved*() = typeParam.getParent()
+  }
+
   override ClassLikeDeclaration getDeclaringItem() { typeParam = result.getATypeParameter() }
 
   override Identifier getNameNode() { result = typeParam.getNameNode() }
@@ -208,6 +216,8 @@ class AssociatedTypeParameterType extends TypeParameter, TAssociatedTypeParamete
 
   Unified::AssociatedTypeDeclaration getAssociatedTypeDeclaration() { result = assocTypeDecl }
 
+  override AstNode getScope() { result.(ClassLikeDeclaration).resolve() = c }
+
   override ClassLikeDeclaration getDeclaringItem() { result = c }
 
   override Identifier getNameNode() { result = assocTypeDecl.getNameNode() }
@@ -233,6 +243,8 @@ class ParentTypeParameterType extends TypeParameter, TParentTypeParameterType {
 
   ClassLikeDeclaration getParent() { isNestedType(c, result) }
 
+  override AstNode getScope() { none() }
+
   override ClassLikeDeclaration getDeclaringItem() { result = c }
 
   override Identifier getNameNode() { none() }
@@ -250,6 +262,8 @@ class UnknownTypeTypeParameter extends TypeParameter, TUnknownTypeTypeParameter
 
   UnknownTypeTypeParameter() { this = TUnknownTypeTypeParameter(i) }
 
+  override AstNode getScope() { none() }
+
   override AstNode getDeclaringItem() { none() }
 
   override Identifier getNameNode() { none() }

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

@@ -18,3 +18,8 @@ query predicate nonUniqueCertainType(AstNode n, TypePath path) {
   Consistency::nonUniqueCertainType(n, path) and
   n.fromSource()
 }
+
+query predicate typeParameterEscape(AstNode n, TypePath path, TypeParameter tp) {
+  tp = inferType(n, path) and
+  forex(AstNode scope | tp.getScope() = scope | not n.getParent*() = scope)
+}

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

@@ -5,10 +5,18 @@ private import TypeInferencePlugin as Plugin
 private import codeql.unified.internal.StaticNameBinding
 private import codeql.unified.internal.ExprPositions
 
+// private predicate isTypeParameterAlias(TypeAliasDeclaration alias, int i) {
+//   exists(Unified::TypeParameter tp |
+//     tp = alias.getTypeParameter(i) and
+//     tp.getNameNode() = getTypeFromRef(alias.getType())
+//   )
+// }
 final class TypeMention = TypeMentionImpl;
 
 /** An AST node that mentions a type. */
 abstract private class TypeMentionImpl extends AstNode {
+  abstract TypeMention resolve();
+
   /**
    * Gets the type mentioned at the root of this type mention.
    *
@@ -131,15 +139,13 @@ abstract private class ExprTypeMentionImpl extends TypeMentionImpl, Expr {
   pragma[nomagic]
   private ClassLikeDeclaration getQualifierTypeAt(TypePath path) {
     result =
-      this.getParentQualifier().getTypeAt(path).(ClassLikeDeclarationType).getClassLikeDeclaration()
+      this.getParentQualifier().getTypeAt(path).(ClassLikeDeclarationType).getClassLikeDeclaration() and
+    forall(TypeParameter tp | tp = path.getElement(_) | tp instanceof ParentTypeParameterType)
   }
 
   pragma[nomagic]
-  private predicate isNestedClass(
-    ClassLikeDeclaration cls, ParentTypeParameterType tp, ClassLikeDeclaration parent
-  ) {
-    cls = this.getClassLikeDeclaration() and
-    tp = TParentTypeParameterType(cls) and
+  private predicate isNestedClass(ParentTypeParameterType tp, ClassLikeDeclaration parent) {
+    tp = TParentTypeParameterType(this.getClassLikeDeclaration()) and
     parent = tp.getParent()
   }
 
@@ -149,12 +155,9 @@ abstract private class ExprTypeMentionImpl extends TypeMentionImpl, Expr {
     result = this.getTypeAtImpl(path)
     or
     // A mention of a nested type with an explicit qualifier
-    exists(
-      TypeMention qualifier, ClassLikeDeclaration cls, ParentTypeParameterType tp, TypePath prefix,
-      TypePath suffix
-    |
+    exists(TypeMention qualifier, ParentTypeParameterType tp, TypePath prefix, TypePath suffix |
       qualifier = this.getParentQualifier() and
-      this.isNestedClass(cls, tp, this.getQualifierTypeAt(prefix)) and
+      this.isNestedClass(tp, this.getQualifierTypeAt(prefix)) and
       path = TypePath::cons(tp, suffix) and
       result = qualifier.getTypeAt(prefix.appendInverse(suffix))
     )
@@ -188,7 +191,11 @@ abstract private class ExprTypeMentionImpl extends TypeMentionImpl, Expr {
   pragma[nomagic]
   private ClassLikeDeclaration getImplicitEnclosingCand(ParentTypeParameterType tp) {
     not this.hasParentQualifier() and
-    not this.getParent*() = any(TypeAliasDeclaration alias).getType() and
+    not exists(TypeAliasDeclaration alias |
+      this.getParent*() = alias.getType() //and
+      // not this.getParent*() = any(GenericTypeExpr g).getATypeArgument() and
+      // not this.getParent*() = any(TupleExpr t).getAnElement()
+    ) and
     tp = TParentTypeParameterType(this.getClassLikeDeclaration()) and
     result = this.getEnclosingClassResolved+()
   }
@@ -233,6 +240,8 @@ class AliasExprTypeMention extends ExprTypeMentionImpl {
     )
   }
 
+  override TypeMention resolve() { result = this }
+
   override TypeMention getAlias() { result = alias.getType() }
 
   override Type getType() { result = alias.getType().(TypeMention).getType() }
@@ -350,6 +359,8 @@ private class NonAliasExprTypeMention extends ExprTypeMentionImpl {
     )
   }
 
+  override TypeMention resolve() { result = this }
+
   override TypeMention getAlias() { none() }
 }
 
@@ -382,6 +393,16 @@ private class GenericTypeExprTypeMention extends TypeMentionImpl, GenericTypeExp
     )
   }
 
+  override TypeMention resolve() {
+    exists(int i |
+      this.getBase().(AliasExprTypeMention).isTypeParameterAlias(i) and
+      result = this.getTypeArgument(i).(TypeMention).resolve()
+    )
+    or
+    base = this.getBase() and
+    result = this
+  }
+
   override Type getType() { result = base.getType() }
 
   override TypeMention getAParentQualifierCand() { result = base.getAParentQualifierCand() }

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

@@ -112,6 +112,15 @@ class Outer<TOuter> {
     }
 }
 
+class Foo: Outer<String> {
+    func f(x: Pair, y: Outer<Bool>.Pair) {
+        var a = x.0.getInner()  // $ target=Outer.Inner.getInner field=Tuple2.0 type=a:Int
+        var b = x.0.getOuter()  // $ target=Outer.Inner.getOuter field=Tuple2.0 $ MISSING: type=b:String
+        var c = y.0.getInner()  // $ target=Outer.Inner.getInner field=Tuple2.0 type=c:Int
+        var d = y.0.getOuter()  // $ target=Outer.Inner.getOuter field=Tuple2.0 $ MISSING: type=d:Bool
+    }
+}
+
 func extractInner<Ta, Tb>(_ inner: Outer<Ta>.Inner<Tb>) -> Tb {
     return inner.getInner()  // $ target=Outer.Inner.getInner
 }