[clang] [analyzer] MallocChecker – Fix false positive leak for smart pointers in temporary objects (PR #152751)

[Pavel Skripkin via cfe-commits]

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@@ -3068,11 +3111,174 @@ void MallocChecker::checkDeadSymbols(SymbolReaper &SymReaper,
   C.addTransition(state->set<RegionState>(RS), N);
 }
 
+// Use isWithinStdNamespace from CheckerHelpers.h instead of custom
+// implementation
+
+// Allowlist of owning smart pointers we want to recognize.
+// Start with unique_ptr and shared_ptr. (intentionally exclude weak_ptr)
+static bool isSmartOwningPtrType(QualType QT) {
+  QT = QT->getCanonicalTypeUnqualified();
+
+  // First try TemplateSpecializationType (for std smart pointers)
+  const auto *TST = QT->getAs<TemplateSpecializationType>();
+  if (TST) {
+    const TemplateDecl *TD = TST->getTemplateName().getAsTemplateDecl();
+    if (!TD)
+      return false;
+
+    const auto *ND = dyn_cast_or_null<NamedDecl>(TD->getTemplatedDecl());
+    if (!ND)
+      return false;
+
+    // Check if it's in std namespace
+    if (!isWithinStdNamespace(ND))
+      return false;
+
+    StringRef Name = ND->getName();
+    return Name == "unique_ptr" || Name == "shared_ptr";
+  }
+
+  // Also try RecordType (for custom smart pointer implementations)
+  const auto *RD = QT->getAsCXXRecordDecl();
+  if (RD) {
+    StringRef Name = RD->getName();
+    if (Name == "unique_ptr" || Name == "shared_ptr") {
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pskrgag wrote:

nit: this looks like a duplicate of 3138. I think it would be better to factor it out into separate lambda.

https://github.com/llvm/llvm-project/pull/152751