Kotlin: fix doc comment extraction for local functions

Author: tamasvajk

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

@@ -1121,10 +1121,6 @@ open class KotlinUsesExtractor(
         // Note not using `parentsWithSelf` as that only works if `d` is an IrDeclarationParent
         d.parents.any { (it as? IrAnnotationContainer)?.hasAnnotation(jvmWildcardSuppressionAnnotaton) == true }
 
-    protected fun IrFunction.isLocalFunction(): Boolean {
-        return this.visibility == DescriptorVisibilities.LOCAL
-    }
-
     /**
      * Class to hold labels for generated classes around local functions, lambdas, function references, and property references.
      */

java/kotlin-extractor/src/main/kotlin/comments/CommentExtractor.kt

@@ -2,6 +2,7 @@ package com.github.codeql.comments
 
 import com.github.codeql.*
 import com.github.codeql.utils.IrVisitorLookup
+import com.github.codeql.utils.isLocalFunction
 import com.github.codeql.utils.versions.Psi2Ir
 import com.intellij.psi.PsiComment
 import com.intellij.psi.PsiElement
@@ -104,7 +105,11 @@ class CommentExtractor(private val fileExtractor: KotlinFileExtractor, private v
                             val existingLabel = if (ownerIr is IrVariable) {
                                 label = "variable ${ownerIr.name.asString()}"
                                 tw.getExistingVariableLabelFor(ownerIr)
-                            } else {
+                            } else if (ownerIr is IrFunction && ownerIr.isLocalFunction()) {
+                                label = "local function ${ownerIr.name.asString()}"
+                                fileExtractor.getLocallyVisibleFunctionLabels(ownerIr).function
+                            }
+                            else {
                                 label = getLabel(ownerIr) ?: continue
                                 tw.getExistingLabelFor<DbTop>(label)
                             }
@@ -130,7 +135,13 @@ class CommentExtractor(private val fileExtractor: KotlinFileExtractor, private v
                 when (element) {
                     is IrClass -> return fileExtractor.getClassLabel(element, listOf()).classLabel
                     is IrTypeParameter -> return fileExtractor.getTypeParameterLabel(element)
-                    is IrFunction -> return fileExtractor.getFunctionLabel(element, null)
+                    is IrFunction -> {
+                        return if (element.isLocalFunction()) {
+                            null
+                        } else {
+                            fileExtractor.getFunctionLabel(element, null)
+                        }
+                    }
                     is IrValueParameter -> return fileExtractor.getValueParameterLabel(element, null)
                     is IrProperty -> return fileExtractor.getPropertyLabel(element)
                     is IrField -> return fileExtractor.getFieldLabel(element)

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

@@ -0,0 +1,8 @@
+package com.github.codeql.utils
+
+import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
+import org.jetbrains.kotlin.ir.declarations.IrFunction
+
+fun IrFunction.isLocalFunction(): Boolean {
+    return this.visibility == DescriptorVisibilities.LOCAL
+}

java/ql/test/kotlin/library-tests/comments/comments.expected

@@ -31,11 +31,11 @@ commentOwners
 | comments.kt:71:9:73:11 | /**\n         * An anonymous function comment\n         */ | comments.kt:70:5:76:10 | getL |
 | comments.kt:71:9:73:11 | /**\n         * An anonymous function comment\n         */ | comments.kt:70:5:76:10 | l |
 | comments.kt:71:9:73:11 | /**\n         * An anonymous function comment\n         */ | comments.kt:70:5:76:10 | l |
+| comments.kt:79:9:81:11 | /**\n         * A local function comment\n         */ | comments.kt:82:9:82:24 | localFn |
 commentNoOwners
 | comments.kt:1:1:1:25 | /** Kdoc with no owner */ |
 | comments.kt:24:9:24:25 | // A line comment |
 | comments.kt:28:5:30:6 | /*\n    A block comment\n    */ |
-| comments.kt:79:9:81:11 | /**\n         * A local function comment\n         */ |
 commentSections
 | comments.kt:1:1:1:25 | /** Kdoc with no owner */ | Kdoc with no owner |
 | comments.kt:4:1:11:3 | /**\n * A group of *members*.\n *\n * This class has no useful logic; it's just a documentation example.\n *\n * @property name the name of this group.\n * @constructor Creates an empty group.\n */ | A group of *members*.\n\nThis class has no useful logic; it's just a documentation example.\n\n |