Refactor firstParentOrNull to accept type parameter and optional pred…

…icate (#2018)

* Refactor firstParentOrNull

* Fix error

* Review feedback

codyze-core/src/main/kotlin/de/fraunhofer/aisec/codyze/Sarif.kt

@@ -104,7 +104,7 @@ private fun Node?.toSarifMessage(): Message? {
  * current function.
  */
 private fun Node.toSarifCallStack(): List<Stack> {
-    val currentFunc = this.firstParentOrNull { it is FunctionDeclaration }
+    val currentFunc = this.firstParentOrNull<FunctionDeclaration>()
     return listOf(
         Stack(
             message = Message(text = "Stack"),

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/ScopeManager.kt

@@ -93,9 +93,7 @@ class ScopeManager : ScopeProvider {
 
     /** The current block, according to the scope that is currently active. */
     val currentBlock: Block?
-        get() =
-            currentScope?.astNode as? Block
-                ?: currentScope?.astNode?.firstParentOrNull { it is Block } as? Block
+        get() = currentScope?.astNode as? Block ?: currentScope?.astNode?.firstParentOrNull<Block>()
 
     /**
      * The current method in the active scope tree, this ensures that 'this' keywords are mapped

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/graph/Extensions.kt

@@ -1062,18 +1062,22 @@ val Node?.assigns: List<AssignExpression>
     get() = this.allChildren()
 
 /**
- * This function tries to find the first parent node that satisfies the condition specified in
- * [predicate]. It starts searching in [this], moving upwards using the [Node.astParent] attribute.
+ * This function tries to find the first parent node of type [T] that satisfies the optional
+ * condition specified in [predicate]. If [predicate] is `null`, the first AST parent node of type
+ * [T] is returned. It starts searching in [this], moving upwards using the [Node.astParent]
+ * attribute.
  *
- * @param predicate the search predicate
+ * @param predicate the optional search predicate
  */
-fun Node.firstParentOrNull(predicate: (Node) -> Boolean): Node? {
+inline fun <reified T : Node> Node.firstParentOrNull(
+    noinline predicate: ((T) -> Boolean)? = null
+): T? {
 
     // start at searchNodes parent
-    var node: Node? = this.astParent
+    var node = this.astParent
 
     while (node != null) {
-        if (predicate(node)) {
+        if (node is T && (predicate == null || predicate(node))) {
             return node
         }
 
@@ -1085,15 +1089,20 @@ fun Node.firstParentOrNull(predicate: (Node) -> Boolean): Node? {
 }
 
 /**
- * This function returns the first parent scope that matches the given [predicate]. If no parent
- * scope matches the predicate, null is returned.
+ * This function tries to find the first parent scope of type [T] that satisfies the optional
+ * condition specified in [predicate]. If [predicate] is `null`, the first parent scope of type [T]
+ * is returned. It starts searching in [this], moving upwards using the [Scope.parent] attribute.
+ *
+ * If no parent scope matches the predicate, null is returned.
  *
- * @param predicate The predicate to match the parent scope against
+ * @param predicate The predicate optional to match the parent scope against
  */
-fun Scope.firstScopeParentOrNull(predicate: (Scope) -> Boolean): Scope? {
+inline fun <reified T : Scope> Scope.firstScopeParentOrNull(
+    noinline predicate: ((T) -> Boolean)? = null
+): T? {
     var scope = this.parent
     while (scope != null) {
-        if (predicate(scope)) {
+        if (scope is T && (predicate == null || predicate(scope))) {
             return scope
         }
 
@@ -1272,7 +1281,7 @@ fun Expression?.unwrapReference(): Reference? {
 /** Returns the [TranslationUnitDeclaration] where this node is located in. */
 val Node.translationUnit: TranslationUnitDeclaration?
     get() {
-        return firstParentOrNull { it is TranslationUnitDeclaration } as? TranslationUnitDeclaration
+        return firstParentOrNull<TranslationUnitDeclaration>()
     }
 
 /**

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/passes/EvaluationOrderGraphPass.kt

@@ -747,7 +747,9 @@ open class EvaluationOrderGraphPass(ctx: TranslationContext) : TranslationUnitPa
         }
         // Forwards all open and uncaught throwing nodes to the outer scope that may handle them
         val outerCatchingNode =
-            node.firstParentOrNull { parent -> parent is TryStatement || parent is LoopStatement }
+            node.firstParentOrNull<Node> { parent ->
+                parent is TryStatement || parent is LoopStatement
+            }
         if (outerCatchingNode != null) {
             // Forwarding is done by merging the currently associated throws to a type with the new
             // throws based on their type
@@ -1311,7 +1313,7 @@ open class EvaluationOrderGraphPass(ctx: TranslationContext) : TranslationUnitPa
         if (throwType != null) {
             // Here, we identify the encapsulating ast node that can handle or relay a throw
             val handlingOrRelayingParent =
-                throwExpression.firstParentOrNull { parent ->
+                throwExpression.firstParentOrNull<Node> { parent ->
                     parent is TryStatement || parent is FunctionDeclaration
                 }
             if (handlingOrRelayingParent != null) {

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/passes/inference/Inference.kt

@@ -597,8 +597,7 @@ class Inference internal constructor(val start: Node, override val ctx: Translat
             }
             is ReturnStatement -> {
                 // If this is part of a return statement, we can take the return type
-                val func =
-                    hint.firstParentOrNull { it is FunctionDeclaration } as? FunctionDeclaration
+                val func = hint.firstParentOrNull<FunctionDeclaration>()
                 val returnTypes = func?.returnTypes
 
                 return if (returnTypes != null && returnTypes.size > 1) {