[clang-tools-extra] [clang-tidy] Ensure nullable variable is not accessed without validity test (PR #90173)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tools-extra

Author: Danny Mösch (SimplyDanny)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/90173.diff


1 Files Affected:

- (modified) clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp (+5-2) 


``````````diff
diff --git a/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp b/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp
index 48bca41f4a3b1e..f077040a35295e 100644
--- a/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp
@@ -64,8 +64,11 @@ void AvoidReturnWithVoidValueCheck::check(
            << BraceInsertionHints.closingBraceFixIt();
   }
   Diag << FixItHint::CreateRemoval(VoidReturn->getReturnLoc());
-  if (!Result.Nodes.getNodeAs<FunctionDecl>("function_parent") ||
-      SurroundingBlock->body_back() != VoidReturn)
+  const auto *FunctionParent =
+      Result.Nodes.getNodeAs<FunctionDecl>("function_parent");
+  if (!FunctionParent ||
+      (SurroundingBlock && SurroundingBlock->body_back() != VoidReturn))
+    // If this is not the last statement in a function body, we add a `return`.
     Diag << FixItHint::CreateInsertion(SemicolonPos.getLocWithOffset(1),
                                        " return;", true);
 }

``````````

</details>


https://github.com/llvm/llvm-project/pull/90173