[c2cpg] Fixed NPE in case of broken catch clauses (joernio#4493)

Fixes: joernio#4491
Privado-Inc · Apr 26, 2024 · 00cfa4d · 00cfa4d
1 parent 568c363
commit 00cfa4d
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Showing 3 changed files with 30 additions and 2 deletions.
diff --git a/joern-cli/frontends/c2cpg/src/main/scala/io/joern/c2cpg/astcreation/AstCreatorHelper.scala b/joern-cli/frontends/c2cpg/src/main/scala/io/joern/c2cpg/astcreation/AstCreatorHelper.scala
@@ -246,6 +246,9 @@ trait AstCreatorHelper(implicit withSchemaValidation: ValidationMode) { this: As
   protected def nullSafeAst(node: IASTExpression): Ast =
     Option(node).map(astForNode).getOrElse(Ast())
 
+  protected def nullSafeAst(node: IASTDeclaration): Seq[Ast] =
+    Option(node).map(astsForDeclaration).getOrElse(Seq.empty)
+
   protected def nullSafeAst(node: IASTStatement, argIndex: Int = -1): Seq[Ast] = {
     Option(node).map(astsForStatement(_, argIndex)).getOrElse(Seq.empty)
   }

diff --git a/...i/frontends/c2cpg/src/main/scala/io/joern/c2cpg/astcreation/AstForStatementsCreator.scala b/...i/frontends/c2cpg/src/main/scala/io/joern/c2cpg/astcreation/AstForStatementsCreator.scala
@@ -133,8 +133,8 @@ trait AstForStatementsCreator(implicit withSchemaValidation: ValidationMode) { t
   private def astForCatchHandler(catchHandler: ICPPASTCatchHandler, argIndex: Int): Ast = {
     val catchNode =
       controlStructureNode(catchHandler, ControlStructureTypes.CATCH, "catch").order(argIndex).argumentIndex(argIndex)
-    val declAst = astsForDeclaration(catchHandler.getDeclaration)
-    val bodyAst = astsForStatement(catchHandler.getCatchBody)
+    val declAst = nullSafeAst(catchHandler.getDeclaration)
+    val bodyAst = nullSafeAst(catchHandler.getCatchBody)
     Ast(catchNode).withChildren(declAst).withChildren(bodyAst)
   }
 

diff --git a/...n-cli/frontends/c2cpg/src/test/scala/io/joern/c2cpg/passes/ast/AstCreationPassTests.scala b/...n-cli/frontends/c2cpg/src/test/scala/io/joern/c2cpg/passes/ast/AstCreationPassTests.scala
@@ -1263,6 +1263,31 @@ class AstCreationPassTests extends AstC2CpgSuite {
       }
     }
 
+    "be correct for try with multiple catches and broken catch clause" in {
+      val cpg: Cpg = code(
+        """
+          |int main() {
+          |  try {}
+          |  catch (int a) {}
+          |  catch (...) {}
+          |}
+          |""".stripMargin,
+        "file.cpp"
+      )
+      inside(cpg.controlStructure.isTry.l) { case List(t) =>
+        val List(tryBlock) = t.astChildren.isBlock.l
+        tryBlock.order shouldBe 1
+        tryBlock.astChildren shouldBe empty
+        val List(catchA, catchB) = t.astChildren.isControlStructure.isCatch.l
+        catchA.order shouldBe 2
+        catchA.ast.isBlock.astChildren shouldBe empty
+        catchA.ast.isLocal.name.l shouldBe List("a")
+        catchB.order shouldBe 3
+        catchB.ast.isBlock.astChildren shouldBe empty
+        catchB.ast.isLocal shouldBe empty
+      }
+    }
+
     "be correct for constructor initializer" in {
       val cpg = code(
         """