[clang] [webkit.RefCntblBaseVirtualDtor] Allow CRTP classes without a virtual destructor. (PR #92837)

[Artem Dergachev via cfe-commits]

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@@ -11,16 +11,134 @@
 #include "PtrTypesSemantics.h"
 #include "clang/AST/CXXInheritance.h"
 #include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/AST/StmtVisitor.h"
 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
 #include "clang/StaticAnalyzer/Core/Checker.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/SetVector.h"
 #include <optional>
 
 using namespace clang;
 using namespace ento;
 
 namespace {
+
+class DerefAnalysisVisitor
+    : public ConstStmtVisitor<DerefAnalysisVisitor, bool> {
+  // Returns true if any of child statements return true.
+  bool VisitChildren(const Stmt *S) {
+    for (const Stmt *Child : S->children()) {
+      if (Child && Visit(Child))
+        return true;
+    }
+    return false;
+  }
+
+  bool VisitBody(const Stmt *Body) {
+    if (!Body)
+      return false;
+
+    auto [It, IsNew] = VisitedBody.insert(Body);
+    if (!IsNew) // This body is recursive
----------------
haoNoQ wrote:

Oh ok it's a one-shot visitor that scans one function and dies. But if it is instantiated again to scan another function that calls a previously visited function, it'll re-scan it from scratch.

So like, this probably ensures termination but there's also probably room for major optimizations there. We don't really have strict performance requirements, esp. for project-specific checks, but at a glance this could matter on some TUs, so it may be a good idea to keep an eye on performance.

https://github.com/llvm/llvm-project/pull/92837