Allow specialised instances of anonymous classes

java/kotlin-extractor/src/main/kotlin/KotlinFileExtractor.kt

@@ -583,12 +583,7 @@ open class KotlinFileExtractor(
             var parent: IrDeclarationParent? = declarationParent
             while (parent != null) {
                 if (parent is IrClass) {
-                    val parentId =
-                        if (parent.isAnonymousObject) {
-                            useAnonymousClass(parent).javaResult.id.cast<DbClass>()
-                        } else {
-                            useClassInstance(parent, parentClassTypeArguments).typeResult.id
-                        }
+                    val parentId = useClassInstance(parent, parentClassTypeArguments).typeResult.id
                     tw.writeEnclInReftype(innerId, parentId)
                     if (innerClass != null && innerClass.isCompanion) {
                         // If we are a companion then our parent has a
@@ -866,7 +861,7 @@ open class KotlinFileExtractor(
                     extractTypeAccess(useType(paramType), locId, paramId, -1)
             }
         }
-        val paramsSignature = allParamTypeResults.joinToString(separator = ",", prefix = "(", postfix = ")") { it.javaResult.signature }
+        val paramsSignature = allParamTypeResults.joinToString(separator = ",", prefix = "(", postfix = ")") { signatureOrWarn(it.javaResult, f) }
         val shortName = getDefaultsMethodName(f)
 
         if (f.symbol is IrConstructorSymbol) {
@@ -1076,6 +1071,9 @@ open class KotlinFileExtractor(
         }
     }
 
+    private fun signatureOrWarn(t: TypeResult<*>, associatedElement: IrElement) =
+        t.signature ?: "<signature unavailable>".also { logger.warnElement("Needed a signature for a type that doesn't have one", associatedElement) }
+
     private fun forceExtractFunction(f: IrFunction, parentId: Label<out DbReftype>, extractBody: Boolean, extractMethodAndParameterTypeAccesses: Boolean, typeSubstitution: TypeSubstitution?, classTypeArgsIncludingOuterClasses: List<IrTypeArgument>?, extractOrigin: Boolean = true, overriddenAttributes: OverriddenFunctionAttributes? = null): Label<out DbCallable>  {
         with("function", f) {
             DeclarationStackAdjuster(f, overriddenAttributes).use {
@@ -1112,7 +1110,7 @@ open class KotlinFileExtractor(
                     paramTypes
                 }
 
-                val paramsSignature = allParamTypes.joinToString(separator = ",", prefix = "(", postfix = ")") { it.javaResult.signature }
+                val paramsSignature = allParamTypes.joinToString(separator = ",", prefix = "(", postfix = ")") { signatureOrWarn(it.javaResult, f) }
 
                 val adjustedReturnType = addJavaLoweringWildcards(getAdjustedReturnType(f), false, (javaCallable as? JavaMethod)?.returnType)
                 val substReturnType = typeSubstitution?.let { it(adjustedReturnType, TypeContext.RETURN, pluginContext) } ?: adjustedReturnType
@@ -2933,20 +2931,8 @@ open class KotlinFileExtractor(
             logger.errorElement("Constructor call has non-simple type ${eType.javaClass}", e)
             return
         }
+        val type = useType(eType)
         val isAnonymous = eType.isAnonymous
-        val type: TypeResults = if (isAnonymous) {
-            if (e.typeArgumentsCount > 0) {
-                logger.warnElement("Unexpected type arguments (${e.typeArgumentsCount}) for anonymous class constructor call", e)
-            }
-            val c = eType.classifier.owner
-            if (c !is IrClass) {
-                logger.errorElement("Anonymous constructor call type not a class (${c.javaClass})", e)
-                return
-            }
-            useAnonymousClass(c)
-        } else {
-            useType(eType)
-        }
         val locId = tw.getLocation(e)
         val valueArgs = (0 until e.valueArgumentsCount).map { e.getValueArgument(it) }
         // For now, don't try to use default methods for enum constructor calls,
@@ -2963,7 +2949,7 @@ open class KotlinFileExtractor(
         }
 
         if (isAnonymous) {
-            tw.writeIsAnonymClass(type.javaResult.id.cast<DbClass>(), id)
+            tw.writeIsAnonymClass(type.javaResult.id.cast(), id)
         }
 
         val dr = e.dispatchReceiver
@@ -4614,7 +4600,7 @@ open class KotlinFileExtractor(
             Pair(paramId, paramType)
         }
 
-        val paramsSignature = parameters.joinToString(separator = ",", prefix = "(", postfix = ")") { it.second.javaResult.signature }
+        val paramsSignature = parameters.joinToString(separator = ",", prefix = "(", postfix = ")") { signatureOrWarn(it.second.javaResult, declarationStack.peek().first) }
 
         val rt = useType(returnType, TypeContext.RETURN)
         tw.writeMethods(methodId, name, "$name$paramsSignature", rt.javaResult.id, parentId, methodId)

java/kotlin-extractor/src/main/kotlin/KotlinUsesExtractor.kt

@@ -210,10 +210,6 @@ open class KotlinUsesExtractor(
     // `typeArgs` can be null to describe a raw generic type.
     // For non-generic types it will be zero-length list.
     fun useClassInstance(c: IrClass, typeArgs: List<IrTypeArgument>?, inReceiverContext: Boolean = false): UseClassInstanceResult {
-        if (c.isAnonymousObject) {
-            logger.error("Unexpected access to anonymous class instance")
-        }
-
         val substituteClass = getJavaEquivalentClass(c)
 
         val extractClass = substituteClass ?: c
@@ -418,10 +414,11 @@ open class KotlinUsesExtractor(
         }
 
         val fqName = replacedClass.fqNameWhenAvailable
-        val signature = if (fqName == null) {
+        val signature = if (replacedClass.isAnonymousObject) {
+            null
+        } else if (fqName == null) {
             logger.error("Unable to find signature/fqName for ${replacedClass.name}")
-            // TODO: Should we return null here instead?
-            "<no signature available>"
+            null
         } else {
             fqName.asString()
         }
@@ -497,16 +494,6 @@ open class KotlinUsesExtractor(
     // `args` can be null to describe a raw generic type.
     // For non-generic types it will be zero-length list.
     fun useSimpleTypeClass(c: IrClass, args: List<IrTypeArgument>?, hasQuestionMark: Boolean): TypeResults {
-        if (c.isAnonymousObject) {
-            args?.let {
-                if (it.isNotEmpty() && !isUnspecialised(c, it, logger)) {
-                    logger.error("Unexpected specialised instance of generic anonymous class")
-                }
-            }
-
-            return useAnonymousClass(c)
-        }
-
         val classInstanceResult = useClassInstance(c, args)
         val javaClassId = classInstanceResult.typeResult.id
         val kotlinQualClassName = getUnquotedClassLabel(c, args).classLabel
@@ -795,7 +782,7 @@ open class KotlinUsesExtractor(
                     extractFileClass(dp)
                 }
             is IrClass ->
-                if (classTypeArguments != null && !dp.isAnonymousObject) {
+                if (classTypeArguments != null) {
                     useClassInstance(dp, classTypeArguments, inReceiverContext).typeResult.id
                 } else {
                     val replacedType = tryReplaceParcelizeRawType(dp)
@@ -1411,20 +1398,24 @@ open class KotlinUsesExtractor(
     private fun getUnquotedClassLabel(c: IrClass, argsIncludingOuterClasses: List<IrTypeArgument>?): ClassLabelResults {
         val pkg = c.packageFqName?.asString() ?: ""
         val cls = c.name.asString()
-        val label = when (val parent = c.parent) {
-            is IrClass -> {
-                "${getUnquotedClassLabel(parent, listOf()).classLabel}\$$cls"
-            }
-            is IrFunction -> {
-                "{${useFunction<DbMethod>(parent)}}.$cls"
-            }
-            is IrField -> {
-                "{${useField(parent)}}.$cls"
-            }
-            else -> {
-                if (pkg.isEmpty()) cls else "$pkg.$cls"
-            }
-        }
+        val label =
+            if (c.isAnonymousObject)
+                "{${useAnonymousClass(c).javaResult.id}}"
+            else
+                when (val parent = c.parent) {
+                    is IrClass -> {
+                        "${getUnquotedClassLabel(parent, listOf()).classLabel}\$$cls"
+                    }
+                    is IrFunction -> {
+                        "{${useFunction<DbMethod>(parent)}}.$cls"
+                    }
+                    is IrField -> {
+                        "{${useField(parent)}}.$cls"
+                    }
+                    else -> {
+                        if (pkg.isEmpty()) cls else "$pkg.$cls"
+                    }
+                }
 
         val reorderedArgs = orderTypeArgsLeftToRight(c, argsIncludingOuterClasses)
         val typeArgLabels = reorderedArgs?.map { getTypeArgumentLabel(it) }
@@ -1435,20 +1426,17 @@ open class KotlinUsesExtractor(
                 ""
             else
                 typeArgLabels.takeLast(c.typeParameters.size).joinToString(prefix = "<", postfix = ">", separator = ",") { it.shortName }
+        val shortNamePrefix = if (c.isAnonymousObject) "" else cls
 
         return ClassLabelResults(
             label + (typeArgLabels?.joinToString(separator = "") { ";{${it.id}}" } ?: "<>"),
-            cls + typeArgsShortName
+            shortNamePrefix + typeArgsShortName
         )
     }
 
     // `args` can be null to describe a raw generic type.
     // For non-generic types it will be zero-length list.
     fun getClassLabel(c: IrClass, argsIncludingOuterClasses: List<IrTypeArgument>?): ClassLabelResults {
-        if (c.isAnonymousObject) {
-            logger.error("Label generation should not be requested for an anonymous class")
-        }
-
         val unquotedLabel = getUnquotedClassLabel(c, argsIncludingOuterClasses)
         return ClassLabelResults(
             "@\"class;${unquotedLabel.classLabel}\"",
@@ -1456,10 +1444,6 @@ open class KotlinUsesExtractor(
     }
 
     fun useClassSource(c: IrClass): Label<out DbClassorinterface> {
-        if (c.isAnonymousObject) {
-            return useAnonymousClass(c).javaResult.id.cast<DbClass>()
-        }
-
         // For source classes, the label doesn't include any type arguments
         val classTypeResult = addClassLabel(c, listOf())
         return classTypeResult.id

java/kotlin-extractor/src/main/kotlin/utils/TypeResults.kt

@@ -12,7 +12,7 @@ package com.github.codeql
  * `shortName` is a Java primitive name (e.g. "int"), a class short name with Java-style type arguments ("InnerClass<E>" or
  * "OuterClass<ConcreteArgument>" or "OtherClass<? extends Bound>") or an array ("componentShortName[]").
  */
-data class TypeResultGeneric<SignatureType,out LabelType: AnyDbType>(val id: Label<out LabelType>, val signature: SignatureType, val shortName: String) {
+data class TypeResultGeneric<SignatureType,out LabelType: AnyDbType>(val id: Label<out LabelType>, val signature: SignatureType?, val shortName: String) {
     fun <U: AnyDbType> cast(): TypeResultGeneric<SignatureType,U> {
         @Suppress("UNCHECKED_CAST")
         return this as TypeResultGeneric<SignatureType,U>

java/ql/lib/semmle/code/java/Type.qll

@@ -686,7 +686,7 @@ class SrcRefType extends RefType {
 /** A class declaration. */
 class Class extends ClassOrInterface, @class {
   /** Holds if this class is an anonymous class. */
-  predicate isAnonymous() { isAnonymClass(this, _) }
+  predicate isAnonymous() { isAnonymClass(this.getSourceDeclaration(), _) }
 
   override RefType getSourceDeclaration() { classes(this, _, _, result) }
 
@@ -800,10 +800,13 @@ class AnonymousClass extends NestedClass {
   }
 
   /** Gets the class instance expression where this anonymous class occurs. */
-  ClassInstanceExpr getClassInstanceExpr() { isAnonymClass(this, result) }
+  ClassInstanceExpr getClassInstanceExpr() { isAnonymClass(this.getSourceDeclaration(), result) }
 
   override string toString() {
-    result = "new " + this.getClassInstanceExpr().getTypeName() + "(...) { ... }"
+    // Include super.toString, i.e. the name given in the database, because for Kotlin anonymous
+    // classes we can get specialisations of anonymous generic types, and this will supply the
+    // trailing type arguments.
+    result = "new " + this.getClassInstanceExpr().getTypeName() + "(...) { ... }" + super.toString()
   }
 
   /**

java/ql/test/kotlin/library-tests/private-anonymous-types/test.expected

@@ -1,15 +1,33 @@
+enclosingTypes
+| file:///!unknown-binary-location/A$<no name provided>.class:0:0:0:0 | new If<T>(...) { ... }<> | file:///!unknown-binary-location/A.class:0:0:0:0 | A<CharSequence> |
+| file:///!unknown-binary-location/A$<no name provided>.class:0:0:0:0 | new If<T>(...) { ... }<> | file:///!unknown-binary-location/A.class:0:0:0:0 | A<String> |
+| test.kt:9:18:11:3 | new If<T>(...) { ... } | test.kt:7:1:22:1 | A |
+| test.kt:13:33:15:3 | new If<T>(...) { ... } | test.kt:7:1:22:1 | A |
+| test.kt:13:33:15:3 | new If<T>(...) { ... }<> | test.kt:7:1:22:1 | A<> |
+#select
+| file:///!unknown-binary-location/A$<no name provided>.class:0:0:0:0 | new If<T>(...) { ... }<> | file:///!unknown-binary-location/A$<no name provided>.class:0:0:0:0 |  |
+| file:///!unknown-binary-location/A$<no name provided>.class:0:0:0:0 | new If<T>(...) { ... }<> | file:///!unknown-binary-location/A$<no name provided>.class:0:0:0:0 |  |
+| file:///!unknown-binary-location/A$<no name provided>.class:0:0:0:0 | new If<T>(...) { ... }<> | file:///!unknown-binary-location/A$<no name provided>.class:0:0:0:0 | getX |
+| file:///!unknown-binary-location/A$<no name provided>.class:0:0:0:0 | new If<T>(...) { ... }<> | file:///!unknown-binary-location/A$<no name provided>.class:0:0:0:0 | getX |
+| file:///!unknown-binary-location/A.class:0:0:0:0 | A<CharSequence> | file:///!unknown-binary-location/A.class:0:0:0:0 | A<CharSequence> |
+| file:///!unknown-binary-location/A.class:0:0:0:0 | A<CharSequence> | file:///!unknown-binary-location/A.class:0:0:0:0 | getAnonType |
+| file:///!unknown-binary-location/A.class:0:0:0:0 | A<CharSequence> | file:///!unknown-binary-location/A.class:0:0:0:0 | getPrivateAnonType$private |
+| file:///!unknown-binary-location/A.class:0:0:0:0 | A<CharSequence> | file:///!unknown-binary-location/A.class:0:0:0:0 | privateUser |
 | file:///!unknown-binary-location/A.class:0:0:0:0 | A<String> | file:///!unknown-binary-location/A.class:0:0:0:0 | A<String> |
 | file:///!unknown-binary-location/A.class:0:0:0:0 | A<String> | file:///!unknown-binary-location/A.class:0:0:0:0 | getAnonType |
+| file:///!unknown-binary-location/A.class:0:0:0:0 | A<String> | file:///!unknown-binary-location/A.class:0:0:0:0 | getPrivateAnonType$private |
+| file:///!unknown-binary-location/A.class:0:0:0:0 | A<String> | file:///!unknown-binary-location/A.class:0:0:0:0 | privateUser |
 | file:///!unknown-binary-location/If.class:0:0:0:0 | If<String> | file:///!unknown-binary-location/If.class:0:0:0:0 | getX |
 | file:///!unknown-binary-location/If.class:0:0:0:0 | If<T> | file:///!unknown-binary-location/If.class:0:0:0:0 | getX |
 | other.kt:1:1:1:34 | Ext | other.kt:1:1:1:34 | Ext |
-| test.kt:0:0:0:0 | TestKt | test.kt:19:1:19:38 | user |
+| test.kt:0:0:0:0 | TestKt | test.kt:24:1:24:38 | user |
 | test.kt:1:1:5:1 | If | test.kt:3:3:3:11 | getX |
-| test.kt:7:1:17:1 | A | test.kt:7:6:17:1 | A |
-| test.kt:7:1:17:1 | A | test.kt:9:3:11:3 | anonType |
-| test.kt:7:1:17:1 | A | test.kt:9:3:11:3 | getAnonType |
-| test.kt:7:1:17:1 | A | test.kt:13:3:15:3 | privateAnonType |
-| test.kt:7:1:17:1 | A | test.kt:13:11:15:3 | getPrivateAnonType$private |
+| test.kt:7:1:22:1 | A | test.kt:7:6:22:1 | A |
+| test.kt:7:1:22:1 | A | test.kt:9:3:11:3 | anonType |
+| test.kt:7:1:22:1 | A | test.kt:9:3:11:3 | getAnonType |
+| test.kt:7:1:22:1 | A | test.kt:13:3:15:3 | privateAnonType |
+| test.kt:7:1:22:1 | A | test.kt:13:11:15:3 | getPrivateAnonType$private |
+| test.kt:7:1:22:1 | A | test.kt:17:3:20:3 | privateUser |
 | test.kt:9:18:11:3 | new If<T>(...) { ... } | test.kt:9:18:11:3 |  |
 | test.kt:9:18:11:3 | new If<T>(...) { ... } | test.kt:10:5:10:22 | x |
 | test.kt:9:18:11:3 | new If<T>(...) { ... } | test.kt:10:14:10:22 | getX |

java/ql/test/kotlin/library-tests/private-anonymous-types/test.kt

@@ -14,6 +14,11 @@ open class A<T>(t: T) {
     override val x = t
   }
 
+  fun privateUser(x: A<String>, y: A<CharSequence>) {
+    val a = x.privateAnonType.x
+    val b = y.privateAnonType.x
+  }
+
 }
 
 fun user(x: A<String>)  = x.anonType.x

java/ql/test/kotlin/library-tests/private-anonymous-types/test.ql

@@ -3,3 +3,7 @@ import java
 from ClassOrInterface ci, Member m
 where m = ci.getAMember() and ci.getSourceDeclaration().fromSource()
 select ci, m
+
+query predicate enclosingTypes(NestedType nt, Type encl) {
+  nt.getSourceDeclaration().fromSource() and encl = nt.getEnclosingType()
+}