Merge pull request #9174 from tamasvajk/kotlin-fix-isUnspecialised

Kotlin: Fix parent class lookup from field initializers in `isUnspecialised`

Author: tamasvajk

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

@@ -4,6 +4,7 @@ import com.github.codeql.KotlinUsesExtractor
 import com.github.codeql.getJavaEquivalentClassId
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext
 import org.jetbrains.kotlin.backend.common.ir.createImplicitParameterDeclarationWithWrappedDescriptor
+import org.jetbrains.kotlin.backend.common.lower.parents
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.ir.builders.declarations.addConstructor
 import org.jetbrains.kotlin.ir.builders.declarations.buildClass
@@ -27,6 +28,7 @@ import org.jetbrains.kotlin.ir.util.parentAsClass
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.types.Variance
+import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstanceOrNull
 
 fun IrType.substituteTypeArguments(params: List<IrTypeParameter>, arguments: List<IrTypeArgument>) =
     when(this) {
@@ -219,12 +221,13 @@ fun isUnspecialised(paramsContainer: IrTypeParametersContainer, args: List<IrTyp
         } ?: false
     }
     val remainingArgs = args.drop(paramsContainer.typeParameters.size)
-    val parent = paramsContainer.parent as? IrTypeParametersContainer
+
+    val parentClass = paramsContainer.parents.firstIsInstanceOrNull<IrClass>()
+
     val parentUnspecialised = when {
         remainingArgs.isEmpty() -> true
-        parent == null -> false
-        parent !is IrClass -> false
-        else -> isUnspecialised(paramsContainer.parentAsClass, remainingArgs)
+        parentClass == null -> false
+        else -> isUnspecialised(parentClass, remainingArgs)
     }
     return unspecialisedHere && parentUnspecialised
 }

java/ql/test/kotlin/library-tests/classes/diags.expected

@@ -0,0 +1,8 @@
+import semmle.code.java.Diagnostics
+
+from Diagnostic d
+where d.getSeverity() > 2
+select d, d.getGeneratedBy(), d.getSeverity(), d.getTag(), d.getMessage(),
+  d.getFullMessage()
+      .regexpReplaceAll("^\\[[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2} K\\] ",
+        "[DATE TIME K] ")