[clang] [webkit.RefCntblBaseVirtualDtor] ThreadSafeRefCounted still generates warnings (PR #108656)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-static-analyzer-1

Author: Ryosuke Niwa (rniwa)

<details>
<summary>Changes</summary>

Improve the fix in 203a2ca8cd6af505e11a38aebceeaf864271042c by allowing variable references and more ignoring of parentheses.

---
Full diff: https://github.com/llvm/llvm-project/pull/108656.diff


2 Files Affected:

- (modified) clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp (+14-5) 
- (modified) clang/test/Analysis/Checkers/WebKit/ref-cntbl-crtp-base-no-virtual-dtor.cpp (+18) 


``````````diff
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp
index ecba5f9aa23ee3..5ea19233bb65c2 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp
@@ -84,13 +84,22 @@ class DerefFuncDeleteExprVisitor
     E = E->IgnoreParenCasts();
     if (auto *TempE = dyn_cast<CXXBindTemporaryExpr>(E))
       E = TempE->getSubExpr();
+    E = E->IgnoreParenCasts();
+    if (auto *Ref = dyn_cast<DeclRefExpr>(E)) {
+      if (auto *Decl = Ref->getDecl()) {
+        if (auto *VD = dyn_cast<VarDecl>(Decl))
+          return VisitLabmdaArgument(VD->getInit());
+      }
+      return false;
+    }
+    if (auto *Lambda = dyn_cast<LambdaExpr>(E)) {
+      if (VisitBody(Lambda->getBody()))
+        return true;
+    }
     if (auto *ConstructE = dyn_cast<CXXConstructExpr>(E)) {
       for (unsigned i = 0; i < ConstructE->getNumArgs(); ++i) {
-        auto *Arg = ConstructE->getArg(i);
-        if (auto *Lambda = dyn_cast<LambdaExpr>(Arg)) {
-          if (VisitBody(Lambda->getBody()))
-            return true;
-        }
+        if (VisitLabmdaArgument(ConstructE->getArg(i)))
+          return true;
       }
     }
     return false;
diff --git a/clang/test/Analysis/Checkers/WebKit/ref-cntbl-crtp-base-no-virtual-dtor.cpp b/clang/test/Analysis/Checkers/WebKit/ref-cntbl-crtp-base-no-virtual-dtor.cpp
index 01527addb52992..33c60ea8ca64d1 100644
--- a/clang/test/Analysis/Checkers/WebKit/ref-cntbl-crtp-base-no-virtual-dtor.cpp
+++ b/clang/test/Analysis/Checkers/WebKit/ref-cntbl-crtp-base-no-virtual-dtor.cpp
@@ -119,6 +119,11 @@ template<class T, DestructionThread destructionThread = DestructionThread::Any>
             ensureOnMainThread([this] {
                 delete static_cast<const T*>(this);
             });
+        } else if constexpr (destructionThread == DestructionThread::MainRunLoop) {
+            auto deleteThis = [this] {
+                delete static_cast<const T*>(this);
+            };
+            ensureOnMainThread(deleteThis);
         }
     }
 
@@ -230,3 +235,16 @@ class FancyRefCountedClass4 final : public BadNestedThreadSafeRefCounted<FancyRe
 private:
     FancyRefCountedClass4();
 };
+
+class FancyRefCountedClass5 final : public ThreadSafeRefCounted<FancyRefCountedClass5, DestructionThread::MainRunLoop> {
+public:
+    static Ref<FancyRefCountedClass5> create()
+    {
+        return adoptRef(*new FancyRefCountedClass5());
+    }
+
+    virtual ~FancyRefCountedClass5();
+
+private:
+    FancyRefCountedClass5();
+};

``````````

</details>


https://github.com/llvm/llvm-project/pull/108656